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FIELD OF THE INVENTION
[0001] The present invention relates generally to locking devices to secure enclosures such as vending machines.
BACKGROUND
[0002] A man was purportedly asked why he robbed banks. His reply was direct, “because that is where the money is”. For much the same reason, machines used in the vending machine industry have been under constant attack from theft and vandalism. First, the machines were padlocked to provide security. The locks were easy to break so the venders used stronger locks. When the locks became too hard to easily break, the thieves began attacking other parts of the lock assembly. What is needed is a lock design that successfully deters any vandalism while still allowing the goods contained in the vending machines to be easily accessible to consumers.
[0003] Several approaches have been tried to protect vending machines used to sell newspapers. Early newspaper racks were not even closed and a metal tube was used to hold the coins. Payment was based on the honor system. The honor system failed and more secure locking devices were required. Newspapers were then placed in enclosed stands and padlocked. Vandals rose to the challenge and easily broke the locks off. The padlock was modified by being attached to a metal rod having the padlock at one end and a plug at the other. The plug was slightly larger in circumference than the rod. So the plug end held the bar secure at one end and the padlock held the rod secure at the other end. Again, vandals rose to the occasion. Shielding was placed around the lock with much the same result.
[0004] The locking device was modified again to place a plug lock at one end of the rod and placing the other end within the coin housing. Soon, vandals were again able to break through the protection.
[0005] One method of protecting such a vending machine is disclosed in U.S. Pat. No. 4,049,106 (the '106 patent) issued to Chalabian. This provided a housing for protecting a coin sorting and control mechanism and a coin storage box for use with a vending machine, such as a newspaper stand. The housing included a body for a coin sorting and control mechanism and a vending machine door latch to lock the door. A cover that fit closely over its top enclosed the body. The cover and body were provided with heavy steel flanges through which a padlock can be passed to lock them together. This device became a standard in the industry and vandals yet again arose to the occasion.
[0006] Therefore, what is needed is a method of protecting newspaper magazines and their contents in a inexpensive and effective manner. Therefore, the goal of the present invention is to economically and efficiently protect vending machines.
SUMMARY
[0007] It is an object of the present invention to protect a vending machine and vending machine lock from vandalism. Some embodiments of the invention provide a device for the protection of vending machines from vandalism by providing a stronger locking mechanism. In some instances, the lock will protect a vending machine that is designed to hold newspapers and the like. For some embodiments, it is the object of the present invention to protect vending machines from attack by providing a locking device having a tubular member with an enlarged proximate end, angled holes for setscrews and a shackle hole at the proximate end
[0008] In accordance with these objects and with others that will be described and which will become apparent, an exemplary embodiment of a locking device in accordance with the present invention is described herein. While the most commonly used application is expected to be the protection of vending machines, the invention may be used on any enclosure that requires a padlock. Thus, both vending machines and other enclosures will simply be referred to as “enclosures”.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The novel features of the invention are set forth in the appended claims. However, for purpose of explanation, several embodiments of the invention are set forth in the following figures.
[0010] FIG. 1 is a side elevation showing in cross section
[0011] FIG. 2 shows an enclosure with the locking device cooperating with the enclosure via-a-vis a coin box.
DETAILED DESCRIPTION
[0012] In the following description, for the purposes of explanation, specific component arrangements and constructions and other details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent to those skilled in the art, however, that the present invention may be practiced without these specific details. In other instances, well known manufacturing methods and structures have not been described in detail so as to refrain from obscuring the present invention unnecessarily.
[0013] Referring first to FIG. 1 , some embodiments of the invention provide for a locking mechanism for vending machines. In one embodiment, the locking mechanism 1 comprises a cylinder 10 having a proximate end 20 and a distal end 22 . The circumference of the cylinder 10 at the proximate end 20 of the cylinder 10 is enlarged sufficiently to allow the emplacement of a locking device 40 . This portion of the cylinder 10 is called the cylinder lock housing 30 . It also has a proximate 32 and a distal end 34 , a threaded interior surface 36 and an exterior surface 38 . These aforementioned and other items cooperate together to form a locking device 1 designed to protect the coin box 60 of the vending machine from attack.
[0014] The '106 Patent to Chalabian provides a description of an enclosure typically used to protect newspapers (FIG. 1) as well as a description of a coin box (FIG. 5). One embodiment of the present invention 1 is designed to fit into and through a coin box of an enclosure such as described in FIG. 5 of the '106 Patent.
[0015] Referring next to FIG. 2 , the coin box housing 60 of vending machine enclosure 50 is shown. The coin box housing includes a sheath 62 around an opening. The opening passes through and to the opposite of the housing 60 . The sheath 62 cooperates with the hole in the coin box housing 60 to form a tight fit with the exterior wall of the coin box housing 60 . When the locking mechanism 1 is inserted into and through the hole of the coin box housing 60 , the locking mechanism 1 cooperates with the coin box housing 60 and the sheath 62 to form a tight fit wherein the proximal end of the cylinder lock housing 32 fits flush against the exterior surface of the sheath 62 .
[0016] Referring now to both FIG. 1 and FIG. 2 , the locking mechanism 1 comprises the cylinder lock housing 30 , a cylinder 10 permanently affixed to the distal end of the cylinder lock housing 34 and a hole 24 at the proximate end of the cylinder 10 . The cylinder lock housing 30 includes a threaded interior surface 36 and an exterior surface 38 . The interior surface 36 of the cylinder lock housing 30 is threaded so as to accept a lock, such as a plug lock. A plug lock is designed to screw into the threaded interior opening of the cylinder lock housing 30 and to cooperate with the threaded interior surface 36 such as to prevent the lock from being pulled out of the cylinder lock housing 34 when set screws are engaged to cooperate with the cylinder lock housing 30 and the plug lock.
[0017] Located on the exterior surface 38 of the cylinder lock housing 30 is a gasket 46 . When the locking mechanism 1 is installed and operational, the gasket 46 is flush with the exterior surface of the coin box housing sheath 62 . Also located on the exterior surface 38 of the cylinder lock housing 10 are openings 42 that pass from the exterior surface 38 to the interior surface 36 . The openings 42 are positioned such that they are located between the gasket 46 and the distal end of the cylinder lock housing 34 . When the locking mechanism 1 is installed and fully cooperating with the coin box housing 60 , the openings 42 are positioned within the interior of the coin box housing 60 . In one embodiment of the present invention, the openings 42 are slanted such that the opening on the exterior surface 38 is closer to the distal end 34 of the cylinder than the openings on the interior surface 36 . The positioning of the openings 42 in this manner prevents vandals from prying in between the sheath 62 and the plug lock to unscrew the setscrews placed in the openings 42 to secure the plug lock in place.
[0018] The distal end of the cylinder 22 includes a shackle hole 24 . The shackle hole allows the passage of a padlock shackle through the hole 22 . When the locking mechanism 1 is installed and fully cooperating with the coin box housing 60 , the padlock is secure against the distal end of the coin box housing 50 and is further protected by a coin box housing sheath (not shown). At the other end, the cylinder lock housing 10 rests firmly within, and flush with, the coin box housing sheath 62 . Further, locking mechanism 1 is installed and fully cooperating with the coin box housing 60 , the plug lock is cooperating with the threaded interior surface 36 , the set screws, the coin box housing sheath 62 , and the set screw openings 42 , to prevent the unauthorized removal of the lock.
[0019] While the invention has been described with reference to numerous specific details, one of ordinary skill in the art will recognize that the invention can be embodied in other specific forms without departing from the spirit of the invention. Thus, one of ordinary skill in the art would understand that the invention is not to be limited by the foregoing illustrative details, but rather is to be defined by the appended claims.
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A locking device for an enclosure, such as a vending machine, wherein the locking device includes an extension capable of receiving and cooperating with a lock at either/or both ends of the extension. The locking device is designed to prevent vandalism to the enclosure.
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FIELD OF THE INVENTION
[0001] The present invention relates to a system for transmitting power and data.
BACKGROUND INFORMATION
[0002] It is generally known that in a rail system for transmitting power and data, a receiver is able to be supplied with power.
SUMMARY
[0003] Therefore, in a system for transmitting power and data, example embodiments of the present invention provide for a grid phase failure detection in a simple manner, in particular, the power being supplied with the aid of a three-phase voltage system, e.g., especially a sinusoidal three-phase voltage system, and the intention being for the information transmitted to the receiver to be digitally detectable.
[0004] Among features of example embodiments of the present invention with regard to the system are that it is provided for transmitting power and data, particularly including a half-wave control, having a control unit connected to grid phases.
[0005] The system includes a phase-failure detection device which has bistable multivibrators, especially bistable multivibrators assigned to a respective grid phase, each bistable multivibrator having an input for setting and an input for resetting, one of the inputs being connected to a digitizing device for digitizing the positive half-waves of a respective grid phase.
[0006] The other of the inputs is connected to a digitizing device for digitizing the negative half-waves of a respective grid phase, the effective value of the output voltage of the bistable multivibrator being compared by a comparison device to a threshold value to detect a phase failure, especially by rectifying and smoothing the output signal, so that a comparison device monitors the smoothed value for exceeding or dropping below a threshold value.
[0007] The output signals of the comparison device are supplied to an OR-operation device to form an output signal of the phase-detection device.
[0008] An advantage in this context is that the failure of the grid phase is quickly detectable and it is possible to use only cost-effective, less complex flip-flops. In this case, each grid phase is supplied to one path in which the positive half-waves are digitized, and to another path in which the negative half-waves are digitized. The digitized pulses assigned to the respective half-wave are then usable as set signal or reset signal for a flip-flop. Thus, a failure is able to be detected in a very simple manner. As soon as the output signal no longer changes fast enough, its effective voltage drops and thus a failure is easily detectable.
[0009] In the control unit, a voltage corresponding to the grid phase voltage, especially a voltage produced by a voltage divider (R 1 , R 2 ) made up of resistors, may be supplied to a diode (D 1 ), whose output signal
is utilized as control voltage for a voltage-dependent switch (Th) and is used for charging a capacitor (C 3 ), especially a condenser (C 3 ), in particular, the charging current being conducted across a diode (D 2 ).
[0013] An advantage in this case is that after the peak value of the voltage of the respective half-wave of a grid phase has been exceeded, the optocoupler generates a pulse-shaped signal whose pulse duration is determined by the capacitance value of capacitor C 3 . Thus, digitizing of the sinusoidal characteristic is permitted in an easy manner.
[0014] A transmitter may connect a line, especially a command phase, selectively to one of a plurality, particularly three, grid phases, a receiver being electrically connected to the grid phases and to the line, particularly via sliding contacts.
[0015] The receiver includes a control unit and a load, especially an electric motor driving a mobile part, which is able to be supplied from the grid phases, the control unit having a digitizing device, each digitizing device being connected to one of the grid phases, and in the digitizing device a voltage corresponding to the grid phase voltage, especially a voltage produced by a voltage divider (R 1 , R 2 ) made up of resistors, is fed to a diode (D 1 ), whose output signal
is utilized as control voltage for a voltage-dependent switch (Th) and is used for charging a capacitor (C 3 ), especially a condenser (C 3 ), in particular, the charging current being conducted across a diode (D 2 ).
[0019] An advantage in this case is that after the peak value of the voltage of the respective half-wave of a grid phase has been exceeded, the optocoupler generates a pulse-shaped signal whose pulse duration is determined by the capacitance value of capacitor C 3 . Consequently, digitizing of the sinusoidal characteristic of the power transmitted with the aid of a collector wire to a rail vehicle is permitted in an easy manner.
[0020] The output signal may feed a resistor (R 3 ), which is connected with one of its two terminals to a reference potential, and with the other of its terminals to diode (D 1 ). An advantage is that the output signal follows the form of the half-wave. In particular, resistor R 3 pulls the output signal toward the reference potential, so to speak, e.g., toward zero.
[0021] A voltage-dependent switch (Th) may enable and/or open a current path when the voltage present at the control input drops below the voltage applied to capacitor (C 3 ), the current path feeding the input of an optocoupler (V 1 ), particularly the illuminant of an optocoupler (V 1 ). An advantage is that only a limited energy reserve is made available by the capacitor, and therefore only a short-duration pulse is able to be generated. In this manner, a single short pulse is assigned to each positive half-wave, or alternatively and in the case of suitable polarity of diode D 1 , to each negative half-wave.
[0022] The system may be arranged a rail system, especially an overhead monorail system, and the receiver may be disposed on a mobile part, especially a rail vehicle. This offers the advantage of permitting a half-wave control, in which information is transmittable from a stationary transmitter to the receiver located on the mobile part.
[0023] The output signal—galvanically isolated from the input—of optocoupler (V 1 ) is supplied to a device for detecting the half-waves, especially a half-wave decoder, the detection device including a comparison device for comparing the output signals of the optocouplers of the digitizing device, in particular, the output signal assigned to the line being compared to the output signals assigned to the grid phases. An advantage is that the pulse generated by the optocoupler is galvanically decoupled and may be further digitally processed.
[0024] Each digitizing unit may be connected to one of the grid phases or to the line, especially command phase, and includes
a digitizing device assigned to the digitizing of the positive half-waves as well as a digitizing device assigned to the digitizing of the negative half-waves.
[0028] This is considered advantageous because in each case, one optocoupler is provided for the positive half-waves and one optocoupler is provided for the negative half-waves.
[0029] The signal digitizing the positive half-waves of a respective grid phase, e.g., especially the output signal—galvanically isolated from the input—of optocoupler (V 1 ) of the digitizing unit assigned to a respective grid phase, may be supplied to the input for setting a bistable multivibrator
[0000] and
the signal digitizing the negative half-waves of a respective grid phase, e.g., especially the output signal—galvanically isolated from the input—of optocoupler (V 1 ) of the digitizing unit assigned to a respective grid phase, may be supplied to the input for resetting a bistable multivibrator,
the effective value of the output signal of the bistable multivibrator being monitored for exceeding or dropping below a threshold value,
particularly by rectifying and smoothing the output signal, so that a comparison device monitors the smoothed value for exceeding or dropping below a threshold value. This is considered advantageous because it permits easy phase-failure detection. In particular, a flip-flop is usable for this purpose.
[0030] The output signals of the comparison device are OR-ed, so that the output signal of this OR operation assumes a first state, especially HIGH, in response to a grid phase failure, and otherwise assumes a different state, especially LOW. An advantage is that the OR operation is easily implemented, particularly in analog manner, with the aid of diodes.
[0031] One terminal each of the voltage divider, resistor (R 3 ), capacitor (C 3 ), the current path and/or the optocoupler of each digitizing device are electrically interconnected, especially so that a reference potential is formed. An advantage is that in this manner, a star point is able to be formed without having to provide a conventional star point having capacitors or resistors in a star connection between the grid phases.
[0032] Further features and aspects of example embodiments of the present invention are explained in greater detail below with reference to the appended Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a schematic block diagram of the control unit, digitizing units 5 and a phase-failure detection device 3 that monitors the output signals of digitizing units 5 .
[0034] FIG. 2 shows a digitizing device, assigned to the positive half-waves, of one of digitizing units 5 in greater detail, the digitizing device generating a digital voltage pulse from each positive half-wave of the respective grid phase voltage.
[0035] FIG. 3 shows more precisely the interconnection of the digitizing device, assigned in each case to the positive half-waves, of the digitizing units.
[0036] FIG. 4 shows phase-failure detection device 3 in greater detail.
DETAILED DESCRIPTION
[0037] As illustrated in the Figures, the control unit permits an evaluation of the phase voltages, particularly a comparison of the command phase to a respective grid phase. In addition, detection of a phase failure is also achievable.
[0038] The grid phases are fed from a three-phase voltage system, and in the ideal case, carry sinusoidal phase voltages shifted relative to each other by 120° and 240°, respectively.
[0039] Data are transmittable with the aid of the command phase. In this context, a transmitter applies a positive or negative half-wave of one of grid phases (L 1 , L 2 , L 3 ) to the command phase. Information is therefore transmittable by applying a respective one of the half-waves of a particular grid phase (L 1 , L 2 , L 3 ) to line C 1 , e.g., command phase C 1 .
[0040] The information is decoded in the control unit by detecting the grid phase (L 1 , L 2 , L 3 ) applied to command phase C 1 at the specific instant.
[0041] Preferably, the control unit is disposed on a mobile unit, which is powered with the aid of a collector wire. Grid phases (L 1 , L 2 , L 3 ) and the command phase are thus transmitted to the mobile part with the assistance of a sliding contact.
[0042] The respective half-waves are converted to digital signals by applicable digitizing unit 5 , e.g., each positive half-wave reaching the input of the control unit assigned a digital signal pulse at the output of a respective first digitizing device, or each negative half-wave reaching the input of the control unit assigned a digital signal pulse at the output of a further respective digitizing device.
[0043] As shown in FIG. 2 in connection with digitizing device of digitizing unit 5 digitizing the positive half-waves, the specific grid phase voltage ( FIG. 2 : grid phase L 1 ) applied at the input of digitizing unit 5 is reduced by the voltage divider, which is formed of the series connection of resistors R 1 and R 2 , and this reduced voltage is conducted through diode D 1 , so that only the positive half-waves are transmitted. Optionally, a capacitor C 2 may be provided for smoothing. The output voltage of diode D 1 feeds a resistor R 3 , whose other terminal is at a reference potential ref 1 . Thus, at resistor R 3 , a voltage is present which is proportional, and in the case of the presence of capacitor C 2 , is substantially proportional to the half-wave-like characteristic of grid phase (L 1 ) applied at the input of digitizing device 5 . From this, a capacitor C 3 is able to be fed via a diode D 2 .
[0044] A voltage-dependent switch Th, especially a thyristor, is powered from the voltage present at capacitor C 3 . The voltage applied at resistor R 3 is used as control voltage applied at the control input of switch Th.
[0045] If the half-wave exceeds its peak and therefore the voltage at resistor R 3 falls, initially the voltage at capacitor C 3 remains constant. As soon as switch Th switches, however, capacitor C 3 will discharge across an optocoupler V 1 disposed at the output of switch Th, and a dropping resistor R 4 for limiting current. The discharge takes place in a time span which is shorter than the duration of the half-wave, e.g., half the period duration of the AC voltage supply.
[0046] Resistors R 2 , R 3 and capacitor C 3 as well as the light-emitting diode of optocoupler V 1 are each connected to reference potential ref 1 with one of their terminals.
[0047] With the aid of optocoupler V 1 , an output signal dig_out of the digitizing device is thus able to be generated at the galvanically isolated output.
[0048] Therefore, for each positive half-wave, a short pulse is thus generated as output signal after the peak of the half-wave has been exceeded.
[0049] As shown in FIG. 1 , grid phase L 1 is thus supplied to digitizing unit 5 , which has a first digitizing device according to FIG. 2 for digitizing the positive half-waves, and a corresponding digitizing device for negative half-waves, that differs basically due to a diode D 1 disposed with reversed polarity.
[0050] Consequently, signal output dig_out belonging to the positive half-waves and the corresponding signal output belonging to the negative half-waves are able to be passed on to half-wave decoder 2 . In the same manner, the corresponding output signals of digitizing units 5 belonging to the other grid phases (L 2 , L 3 ) and to command phase C 1 are conducted to half-wave decoder 2 .
[0051] In the half-wave decoder, command phase C 1 is thus able to be compared to grid phases (L 1 , L 2 , L 3 ), and the transmitted information is thereby able to be decoded and supplied to control 4 .
[0052] The failure of a grid phase is detectable with the aid of phase-failure detection device 3 . If at least one of the grid phases fails, a corresponding warning signal for this is transmitted to control 4 . Thus, the warning signal is able to be taken into account in the evaluation.
[0053] The transmission of information is therefore able to be made more reliable.
[0054] Phase-failure detection device 3 has three bistable multivibrators 40 , preferably in the form of flip-flops, especially RS or JK flip-flops. Each bistable multivibrator 40 has an input S, e.g., an input for setting, and an input R, e.g., an input for resetting.
[0055] The specific input for setting is connected to the applicable output dig_out of the digitizing device, assigned to the positive half-waves, of respective digitizing unit 5 .
[0056] The specific input for resetting is connected to the applicable output of the digitizing device, assigned to the negative half-waves, of respective digitizing unit 5 .
[0057] Consequently, the output of first bistable multivibrator 40 assigned to grid phase L 1 is set by the arrival of the positive half-wave of grid phase L 1 , and reset by the subsequent arrival of the negative half-wave.
[0058] The output signal of respective bistable multivibrator 40 is routed across a capacitor C 4 , and thus DC voltage components suppressed. The output signal filtered in this manner is rectified by a rectifying device 41 and smoothed by a smoothing device 42 , especially a capacitor, so that substantially a DC voltage is produced.
[0059] The voltage value smoothed by smoothing device 42 is compared to a critical voltage value by a comparison device 43 . The critical voltage value is selected such that if exceeded, no failure of the grid phase exists, and if not attained, a failure of the grid phase is present.
[0060] The output signals of the comparison device assigned to grid phases (L 1 , L 2 , L 3 ) are supplied to a logic-operation device 44 , especially a summation device, which combines the three signals such that in response to a failure of one or more of grid phases (L 1 , L 2 , L 3 ), a corresponding output signal 45 is generated. Thus, the grid phase failure is easily detectable and able to be indicated in a single output signal.
[0061] If one of grid phases (L 1 , L 2 , L 3 ) fails, associated bistable multivibrator 40 no longer changes its output state. Consequently, the voltage at the output of smoothing device 42 drops, and comparison device 43 generates a HIGH level as output voltage instead of the LOW level generated in response to the presence of the grid phase.
[0062] The reference potentials of all digitizing devices of all digitizing units 5 are electrically connected and therefore form a star point, e.g., a reference potential. An additional star point formed by resistors and/or other components between the grid phases is therefore not necessary.
[0063] In a further exemplary embodiment, the warning signal is even transmitted to half-wave decoder 2 and taken into account there when decoding the information.
LIST OF REFERENCE CHARACTERS
[0000]
1 Half-wave evaluation device
2 Half-wave decoder
3 Phase-failure detection device
4 Control
5 Digitizing unit
40 Bistable multivibrator, particularly flip-flop, especially RS or JK flip-flop
41 Rectifying device
42 Smoothing device
43 Comparison device
44 Logic-operation device, especially a summation device
45 Output signal
L 1 First grid phase
L 2 Second grid phase
L 3 Third grid phase
C 1 Command phase
VCC Supply voltage
GND Ground
Ref 1 Reference potential
Dig_out Output signal of digitizing unit 5
Th Voltage-dependent switching element, especially thyristor
C 2 Capacitor
C 3 Capacitor
C 4 Capacitor
D 1 Diode
D 2 Diode
R 1 Resistor
R 2 Resistor
R 3 Resistor
R 4 Resistor
R 5 Resistor
V 1 Optocoupler
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A system for transmitting power and data, particularly including a half-wave control, includes a control unit connected to grid phases, the system having a phase-failure detection device which has bistable multivibrators, especially bistable multivibrators assigned to a respective grid phase. Each bistable multivibrator has an input for setting and an input for resetting, one of the inputs being connected to a digitizing device for digitizing the positive half-waves of a respective grid phase, the other of the inputs being connected to a digitizing device for digitizing the negative half-waves of a respective grid phase. The effective value of the output voltage of the bistable multivibrator is compared by a comparison device to a threshold value to detect a phase failure.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mechanical sensor for sensing a sudden deceleration of a vehicle.
2. Background Information
Among known vehicle seat belt units there are those equipped with a so-called pretensioner. At the time of a sudden acceleration (including deceleration) of the vehicle, the pretensioner retracts the webbing which a passenger is wearing by a predetermined amount so as to forcefully take up slack in the webbing thereby improving the restraint of the passenger.
In pretensioners of this type the tautness of the webbing is caused by the forced rotation of the webbing retractor shaft, while other types cause the tension of the webbing by a forced pull of the buckle. A pretensioner of the type that pulls the buckle to tension the webbing, for example, is equipped with a gas generator having a mechanical igniting sensor. The gas generator, which is provided with a cylinder, is connected to a buckle via a wire or the like.
At a sudden deceleration of a vehicle, the mechanical igniting sensor senses the deceleration so as to activate the gas generator. The instantaneous generation of gas moves the cylinder so that the force of the movement is transmitted to the buckle via the wire so as to tension the webbing.
The mechanical igniting sensor employed in a pretensioner of this prior art is basically composed of an ignition pin that fires a detonator, an inertial body that is moved inertially due to a large acceleration, a trigger member such as a ball that is present between the ignition pin and the inertial body so as to restrain the ignition pin from moving. One example is seen in U.S. Pat. No. 3,638,501. In this mechanical igniting sensor, in which only the above-mentioned trigger member is provided between the inertial body and the ignition pin so as to prevent the ignition pin from moving out of its normal state, there are many factors which affect precision(the sensitivity of the operation of the mechanical igniting sensor) during operation from the inertial movement of the inertial body that releases the hold on the ignition pin to the subsequent firing of the detonator. For example, there are directional differences between the pressure that the ignition pin applies to the trigger member and the pressure that the trigger member applies to the inertial body. Furthermore, these pressure directions change with the movement of the inertial body. There are other elements that affect the sensitivity of the operation of the mechanical igniting sensors. For example, the frictional force between the trigger member and the inertial body changes greatly during the movement of the inertial body. Because of these factors, the sensitivity of the operation is not steady, and a stable sensor operation is difficult to obtain. In some cases, the pressure on the trigger member coming from the ignition pin can be amplified because of the change in the direction of the pressure. In such cases, the amplified pressure given to the inertial body increases the frictional force between the trigger member and the inertial body. As a result, it causes the dispersion of sensitivity and the loss of operation stability.
In addition, the pressing forces on the trigger member of the mechanical igniting sensor in the prior art tend to counteract each other. It is therefore possible that the trigger member will fail to move as it should or stall even under a predetermined inertial force.
In this case, to simply increase the inertial mass so as to decrease the effects of the frictional force between the trigger member and the inertial body would only increase the size and weight of the unit as a whole.
Furthermore, in the operation of the mechanical igniting sensor in the prior art, once the trigger member has come out from between the inertial body and the ignition pin and the firing pin has been released from constraint, it is extremely difficult to reset the sensor to a state in which the movement of the ignition pin is prevented.
To test the mechanical igniting sensor, it is possible to test the sensor with respect to sensitivity and other operational properties and confirm the exactness of the operation. However, it is not possible to combine the tested sensor with a gas generator so that the unit will become operational reset. A solution to this problem, therefore, is needed for it is not possible to Omit the test operation of the mechanical igniting sensor.
SUMMARY OF THE INVENTION
In consideration of the above, it is an object of the present invention to provide a mechanical sensor having a simple structure that is able to reduce the unwanted effects of frictional force and insure stable sensor operation.
Another object of the present invention is to provide a mechanical sensor having a simple structure that can be reset easily after a test operation of sensitivity and the like without sacrificing stability of operation.
The mechanical sensor of the present invention is structured such that when the inertial body moves, the inertial body and the trigger lever move relative to each other while maintaining linear contact.
In other words, when the slide holding portion of the trigger lever is separated and released from the inertial mass body, the trigger lever is freed so as to rotate about its supporting shaft. As a result, the ignition pin that is urged by a firing spring rotates the trigger lever in a direction so as to separate the trigger lever from the ignition pin. This releases the ignition pin from engagement with the engaging portion of the trigger lever. The ignition pin then is moved by the urging force of the firing spring in the axial direction to fire the detonator.
During the operation of the sensor, the inertial mass body moves in its linear contact with the slide holding portion of the trigger lever. As a result, friction between the trigger lever (slide holding portion) and the inertial mass body remains constant, thus contributing to the stable sensitivity of the mechanical ignition sensor during operation.
In addition, friction between the slide holding portion and the inertial mass body can be easily reduced to increase the effects of the trigger lever if the lever ratios between the supporting shaft and the slide holding portion, and the supporting shaft and the engaging portion are set properly.
In this way, the mechanical sensor of the present invention is able to insure stable operation by reducing the unwanted effects of friction between the trigger lever and the inertial mass body without increasing the mass of the inertial body.
Various means of moving the trigger device can be adopted so that the trigger means remains unmoving until the inertial body has moved a predetermined amount. The intertial body will move quickly and sharply once the inertial body has moved the predetermined amount. The measures that may be used for this purpose include the formation of a block-like portion on the inertial body and/or the trigger means where the two come into contact with each other, and the formation of a step or edge in which the inertial body, toward the end of its movement, will suddenly separate from the trigger means.
It is possible to provide an interfering portion on the trigger lever that interferes with a portion of the firing pin which, having finished operation, will be returning to the original position. Here, the return of the firing pin will cause the resetting of the trigger lever.
In this way, a simple return of the igniting pin along an axial line toward the initial position can cause the trigger lever to rotate to the initial position in which the firing pin is held in place. This will allow an easy post-testing resetting. The mechanical igniting sensor having undergone an operation test is then assembled with a gas generator to become an operating unit.
A spring can urge the inertial mass body in a direction so as to enter the locus of movement of the trigger lever. In this manner, the inertial body will impart a force to the trigger lever so as to engage the firing pin. In this setting, the resistance of the firing pin toward the initial position will engage the pin with the trigger lever and reset the unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view illustrating the initial state of a mechanical sensor according to a first embodiment of the present invention.
FIG. 2 is a cross sectional view illustrating the state of the mechanical sensor after having finished operation in accordance with the first embodiment of the present invention.
FIG. 3 is a cross sectional view illustrating the initial state of a mechanical sensor according to a second embodiment of the present invention.
FIG. 4 is a cross sectional view illustrating the state of the mechanical sensor after having finished operation in accordance with the second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 show cross sectional views of a mechanical igniting sensor 10 of the present invention.
The mechanical igniting sensor 10 has a case 12. The case 12 is shaped as a cylinder having a bottom wall 14 at one end. The open side of the case 12 is sealed by a plate 16. In the bottom wall 14 of case 12 a hole 18 penetrates axially therethrough. In the bottom wall 14 a guide 20, which is of a substantually cylindrical shape, is formed coaxially so as to protrude toward the inner direction of the case 12.
Inside the case 12 is a firing pin or ignition pin 22. The ignition pin 22 is composed of a main body 24 which is substantually cylindrical in form, and a projecting portion 26, that is integrally formed with the bottom wall 24A of the main body 24. The outside diameter of the main body 24 corresponds to the inside diameter of the guide 20. The main body 24 is slidable within the guide 20 along an axial line in the case 12. As indicated in FIG. 2, when the ignition pin 22 (main body 24) has moved toward the bottom wall 14 of the case 12 as far as it can go, the projecting portion 26 projects out of the penetration hole 18 that is formed in the bottom wall 14.
A firing spring 28, which is provided between ignition pin 22 and the plate 16, normally urges the ignition pin 22 in the direction of the penetration hole 18.
Provided around the guide 20 is an inertial mass 30. The inertial mass 30, which is substantually in a cylindrical shape, is accomodated between the surrounding walls of the case 12 and the guide 20 so as to be movable. A biasing spring 32 are placed between the inertial mass 30 and the plate 16 so as to constantly urge the inertial mass 30 against the bottom wall 14.
Arranged between the inertial mass 30 and the ignition pin 22 are a pair of trigger levers 34. An end portion of each trigger lever 34 is rotatably supported to a shaft 36. The other end of the trigger lever 34 is bent toward the ignition pin 22 to form an engaging portion 38 so as to be engagable with the ignition pin 22. In other words, the trigger lever 34 rotates around the shaft 36 in such a way that the engaging portion 38 can move toward or away from the ignition pin 22. In a state in which the engaging portion 38 of the trigger lever 34 has engaged the main body 24 of the ignition pin 22 as indicated in FIG. 1, the ignition pin 22, under the urging of the firing spring 28, is held in a position in which its projected portion 26 is drawn out of the penetration hole 18.
In a longitudinal middle portion of the trigger lever 34 and on the side opposite ignition pin 22 a slide holding section 40 projects toward the inertial mass 30. The slide holding section 40 corresponds to a sliding portion 31 formed on the inertial mass 30, and is structured so that it will remain in linear contact with the sliding section 31. Normally the inertial mass 30 is urged by the bias spring 32 against the bottom-most part of bottom wall 14 of case 12. In this state, the sliding portion 31 of the inertial mass 30 is contact with the slide holding section 40 of trigger lever 34. The engaging portion 38 of the trigger lever 34 is engaged with the main body 24 of the ignition pin 22, and holds the projecting portion 26 of the ignition pin 22 in a position that is drawn out from the penetration hole 18. Further, when the inertial mass 30 moves so as to be separated from the bottom wall 14, the sliding section 31 of the inertial mass 30 and the slide holding portion 40 of the trigger lever 34 maintains linear contact while moving relative to each other.
The slide portion 31 may be brought into contact with the slide holding portion 40 on the surface of a semicircular arc which has its center on an axis that is parallel to the axial line of the ignition pin 22. The slide holding portion 40 may also have a similar arc surface where it makes contact with the slide section 31.
In addition, at the rear end of the trigger lever 34 (the end opposite engaging section 38) a pressing projection 41 is provided, which faces the ignition pin 22. As shown in FIG. 2, the sizes and other specifications of the pressing projection 41 have been determined so that the projection 41 can enter the locus of movement of the ignition pin 22 and engage the rear end thereof once the trigger lever 34 has rotated and released the hold of the engaging portion 38 on the ignition Pin 22. With this, the sliding of the ignition pin 22 away from the penetration hole 18 can cause the rear end of the ignition pin 22 to press the projection 41.
The mechanical igniting sensor 10 with the above-described structure is assembled to, for example, a gas generator used with a pretensioner (not illustrated). The gas generator contains a gas-generating agent. There is also a detonator 42 for igniting and combusting the gas-generating agent. After the mechanical ignition sensor 10 and the gas generator are assembled, the detonator 42 is located on the axial line of the mechanical ignition sensor 10. In this state, the penetration hole 18 in the case 12 faces the detonator 42, so that the projecting portion 26 of the ignition pin 22 can project through the penetration hole 18, and strike the detonator 42.
Next, the operation of the present embodiment will be explained.
In the mechanical igniting sensor 10 with the above described structure, normally the ignition pin 22 is in the position shown in FIG. 1. That is, the ignition pin 22 is separated from the detonator 42 against the bias force of the firing spring 28 (in a position drawn out of the penetration hole 18 in the case 12). In this position, the engaging portion 38 of the trigger lever 34 is engaged with the main body 24 of the ignition pin 22, thus holding the ignition pin 22 from moving. The inertial mass 30, pressed by the bias spring 32, has come to the bottom-most part of the bottom wall 14, that is, in the locus of the rotation of the trigger lever 34. The slide portion 31, coming into contact with the slide holding portion 40 of the trigger lever 34, prevents the trigger lever 34 from rotating, thereby keeping hold on the ignition pin.
When a sudden acceleration activates the mechanical ignition sensor 10, the inertial mass 30 inertially moves in the direction of an arrow A, and separates from the rotation locus of the trigger lever 34.
The inertial mass 30 (slide section 31) moves while maintaining linear contact with the slide holding section 40 of the trigger lever 34. Once the slide holding section 40 of the trigger lever 34 is separated from the slide section 31 of the inertial mass 30 and holding released, the trigger lever 34 is the rotatable around shaft 36. Thereby, the ignition pin 22 presses the trigger lever 34 in such a direction that the trigger lever 34 will be rotated and separated from the ignition pin 22. The engaging portion 38 of the trigger lever 34 is then disengaged from the main body 24 of the ignition pin 22, thereby releasing the holding of the ignition pin 22. As a result, the ignition pin 22, under the urging of the firing spring 28, moves in the axial direction, causing the projecting portion 26 to protrude through the penetration hole 18 (see FIG. 2).
This causes the projecting portion 26 of the ignition pin 22 to strike the detonator 42 and ignite it. Upon igniting the detonator 42, the gas-generating agent in the gas generator ignites and combusts thereby activating a pretensioner, for example.
During the operation of the mechanical ignition sensor 10, that is, during the movement of the inertial mass 30, the frictional force between the trigger lever 34 (slide holding portion 40) and the inertial mass 30 (slide portion 31) is constant and without fluctuations because the slide portion 31 moves while maintaining linear contact with the slide holding portion 40 of the trigger lever 34. In other words, the direction in which the ignition pin 22 pushes the trigger lever 34 and the direction in which the trigger lever 34 presses the inertial mass 30 do not vary as they do in the prior art. Accordingly, the frictional force between the trigger lever 34 (slide holding portion 40) and the inertial mass 30 (slide portion 31) does not markedly change as the inertial mass 30 moves. As a result, the sensitivity of the mechanical ignition sensor 10 is stabilized.
Furthermore, the suitable setting of the trigger lever 34, as to the lever ratios between the shaft 36 and the slide holding portion 40, and the shaft 36 and the engaging portion 38 will enhance the effects of the sensor by reducing the frictional force between the aforementioned trigger lever 34 (slide holding portion 40) and the inertial mass 30 (slide portion 31). For example, by bringing the slide holding portion 40 closer to the shaft 36, such enhanced effectiveness can be expected.
In the mechanical ignition sensor 10, various pressing forces on the trigger lever 34 do not cancel each other while the inertial mass 30 is moving. Accordingly, once a predetermined inertial force starts working, the inertial mass 30 and the trigger lever 34 are prevented from stopping midway.
Once the mechanically ignition sensor 10 is activated and the ignition pin 22 has moved, the pressing projection 41 of the trigger lever 34 has entered the locus of movement of the ignition pin 22 facing to the rear end of the ignition pin 22, so as to be ready to engage therewith.
Next, to return an already activated mechanical ignition sensor 10 to a state ready for another operation (i.e., to reset), the ignition pin 22 can be moved in the axial direction against the urging force of the firing spring 28.
To implement this resulting, the projecting portion of the ignition pin 22, which projects out of the penetration hole 18, is pressed in the direction of the plate 16 from the outside of the case 12 using a jig or the like.
With the movement of the trigger lever 34 toward the side of plate 16 the ignition pin 22 presses the pressing projection 41 of the trigger lever 34, which has entered the locus of movement of the ignition pin 22. As a result, the trigger lever 34 is rotated about the shaft 36 in such a manner that the engaging section 38 approaches the ignition pin 22. When the ignition pin 22 has reached the initial position, the engaging portion 38 reengages the ignition pin 22 (bottom wall 24A of the main body 24) and holds the ignition pin 22 in its initial position which is away from the detonator 42. Furthermore, as the trigger lever 34 rotates, the inertial mass 30, which is pressed by the bias spring 32, reenters the locus of the rotation of the trigger lever 34 so as to stop the rotation and initiate the ignition pin-holding state.
As described above, the mechanical ignition sensor 10 assures stable operation by decreasing the unwanted effects of the frictional force between the trigger lever 34 and the inertial mass 30. In addition, by merely pressing the ignition pin 22 from outside to return it to the initial position, the trigger lever 34 is rotated to return to its initial position in which the ignition pin 22 is held. Accordingly, the mechanical ignition sensor 10 having undergone an operation test before it is assembled with a gas generator may thereafter be assembled with the gas generator and easily reset to the operative state.
Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. In this example, those parts that function in the same way as those parts in the first embodiment will have the same numbers assigned as those found in FIGS. 1 and 2 except for the addition of "A" at the end of each number.
In this embodiment, a flange portion 24C is formed on the ignition pin main body 24B at the end opposite the projecting portion 26A. The flange portion 24C is larger in diameter than the other part of the firing pin main body 24A. The flange portion 24C engages the L-shaped distal end portion of the trigger lever 34A. The L-shape portion serves as the engaging portion 38A, via a through hole 20B of the cylindrical guide 20A. On the side of the trigger lever 34A that is opposite to the side of the engaging section 38A a small diameter step portion 30B of the inertial mass 30A is provided. The small diameter step portion 30B is in contact with the trigger lever 34A on the other side of the engaging section 38A and thus maintains the engagement of the trigger lever 34A with the ignition pin main body 24B. The inertial mass 30A of this embodiment is also pressed by the bias spring 32A. However, the direction in which the inertial mass 30A is pressed is opposite to the direction in which the inertial mass 30 in the first embodiment was pressed (opposite direction indicated by arrow A). The inertial mass 30A of this embodiment is biased in the direction opposite to the biasing direction of the ignition pin.
On the L-shaped bent portion of the trigger lever 34A a chamfer-shaped sloped surface 34B is formed so that the sloped surface 34B corresponds to the small diameter step portion 30B. When the trigger lever 34A rotates so as to take the engaging portion 38A out of the through hole 20B in the guide 20A (FIG. 2), the sloped surface 34B corresponds to the step portion 30B.
An acceleration sensor 10A with a structure like that described above may be assembled with a gas generator 50 for use as a pretensioner, for example.
As shown in FIG. 3, inside a cylindrically shaped main body 52 of the gas generator 50 a gas-generating agent 54 is accomodated. A detonator 56 that will cause the ignition and combustion of the gas-generating agent 54 is also in the main body 52. A detonator 56 is located in the axial center portion of the main body 52. The acceleration sensor 10A faces the detonator 56. A shielding ring 58 is provided between the acceleration sensor 10A and the detonator 56. The sensor is then sealed and secured by a plate 60. In a state in which the acceleration sensor 10 has been assembled with the main body 52, the penetration hole 18A in the sensor cover 14A faces the detonator 56, and the projecting portion 26 of the ignition pin can protrude through the penetration hole 18A so as to strike the detonator 56.
Next, the operation of the second embodiment will be explained.
FIG. 3 represents the state of the sensor 10A during the normal operation of the vehicle. In this state the ignition pin main body 24B is held by the trigger lever 34A.
When the acceleration sensor 10A senses the sudden deceleration of the vehicle, the inertial mass 30A moves in the direction of arrow A, against the urging force of the bias spring 32A. As a result of this movement, the restrictions imposed on the trigger lever 34A are released by the inertial mass 30A. The trigger lever 34A is now free to rotate. The ignition pin main body 24B is moved in the direction of arrow A by the urging force of the firing spring 28A, and strikes and ignites the detonator 56. The resultant ignition and combustion of the gas-generating agent 54 in the gas generator 50 activate the pretensioner.
In this state, the step portion 30B of the inertial mass 30A is in contact with the sloped surface 34B. It is therefore possible to reset the ignition pin by moving the pin in the axial direction against the urging force of the firing spring 28A.
As shown in FIG. 4, the ignition pin main body 24B with its projecting portion 26A protruding from the penetration hole 18A is pressed by jig X from outside of the sensor case 12A so as to move jig X into the guide 20A (in the direction of arrow A in FIG. 4). This causes the step portion 30B of the mass body 30A which is pressed by the bias spring 32A to press the trigger lever 34A in the direction of the ignition pin main body 24B via its sloped surface 34B. As a result, the ignition pin main body 24B moves to the initial position. At this point, the engaging section 38A of the trigger lever 34A engages the flange 24C of the ignition pin main body 24B, holds the ignition pin main body 24B in the initial position, and reset the sensor 10A.
In the above-described embodiment, the slope of the sloped surface 34B may be a curved surface instead of a straight sloped surface in the figure. The radius of curvature of the curved surface may be selected arbitrarily. Also, the sloped surface 34B does not necessarily have to be provided on the trigger lever 34A. It may be provided on the inertial mass 30A, as long as it is a sloped surface that can transmit via the inertial mass 30A the force of the bias spring 32A as the force that returns the trigger lever 34A.
In the previously described mechanical ignition sensor 10, the firing pin 22 was held by a pair of the trigger lever 34. However, the number of trigger levers is not limited. There may be one or three or more levers 34.
In addition, the previously described mechanical ignition sensors used a gas generator type pretensioner. However, the application of the sensors are not restricted to this use. It is possible to apply these sensors to other systems that will act upon the impact of a firing pin such as an air bag system that will inflate a bag in front of a passenger during an emergency of the vehicle.
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Upon a sudden deceleration of a vehicle, if an inertial body moves a predetermined amount against the urging force of a return spring, the trigger means will be released from engagement with the firing pin. Under the urging force of a spring, the firing pin is released from engagement with the trigger means, strikes and ignites a detonator so as to activate the actuator. The trigger means will not move until the inertial body has moved by the predetermined amount. Only after the inertial body has moved the predetermined amount, will the trigger means start to move suddenly and quickly. Therefore, friction at the time the inertial body engages the trigger means is kept constant. The stable operation of the sensor is thereby assured.
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TECHNICAL FIELD
[0001] This invention belongs to the field of sludge treatment technology, more particularly, to a method and apparatus for aerobically air-drying sludge filter cakes wherein the drying of the sludge is operated by taking advantage of the combination of external energy and internal heat of the sludge.
BACKGROUND ART
[0002] Sewage treatment creates sludge in large amounts. To reclaim the sludge, sludge filter cakes produced from mechanically dewatering should be subjected to further drying treatment.
[0003] Up to now, the commonly used method for drying sludge filter cakes is drying with warm air, in which moisture in the sludge is rapidly evaporated by directly or indirectly raising the temperature of sludge per se with air at medium and high temperature. But, such method has the following five disadvantages: 1. It leads to high energy consumption in the sludge drying process. 2. It is difficult to deal with tail gases from the sludge drying process. 3. It requires a substantial investment for the apparatus. 4. The apparatus has terrible operation stability. 5. There is a fair possibility of dust explosions.
SUMMARY OF THE INVENTION
[0004] An object of the present invention is to overcome the deficiencies of the above mentioned treatment of sludge filter cakes by providing a method for low temperature air-drying sludge filter cakes which has lower energy consumption, less pollution from tail gases, smaller apparatus investment, more stable operation and higher safety.
[0005] The invention embodies as a method for low temperature drying sludge filter cakes including steps of:
[0006] (1) crushing and dispersing the sludge filter cakes into a layer of sludge granules to enlarge the specific surface area of the sludge,
[0007] (2) blowing with positive pressure dry air at a certain temperature into the layer of sludge granules moving at low speed or overturned so that the sludge granules experience aerobically exothermic reactions, which make moisture rapidly evaporated from sludge granules and moved to the dry air by mass transferring under the effect of both the external heat and internal heat,
[0008] (3) physically or chemically sterilizing the sludge granules moving at low speed or overturned,
[0009] (4) pumping out tail gas by negative pressure from the layer of sludge granules, washing and then discharging, and
[0010] (5) further pulverizing the dried sludge granules during the conveying of the dried sludge granules with a screw crushing device by making the materials crushing and rubbing with each other to reach the reclamation requirement for use as fertilizers, in bricks manufacture, as fuels and as fillers.
[0011] The above crushing and dispersing of the sludge filter cakes is accomplished by overturning the sludge filter cakes with a moisture content of 50% to 70% in a porous or interstitial cage and crushing the sludge filter cakes via the attrition and collision therebetween. The sludge granules with external diameters less than those of the pore or the gap distances of the cage breakthrough the cage and thereby the step of the crushing and dispersing of sludge filter cakes is accomplished. The diameters of the pore or the gap distances are set between 3 mm and 30 mm. The resulting sludge granules within the range, when free settled, have a relatively small bulk density, which may facilitate the gas in and out. The overturning of sludge filter cakes in the cage may be driven by the screw inside the cage or the rotation of the cage per se. The speed of overturning sludge filter cakes in the cage is adjusted according to moisture content of sludge filter cakes and output remand according to the following regulars: {circle around (1)}. The higher moisture content of sludge filter cakes is, the lower the overturning speed is, and vice versa. The most importance is to minimize the destruction of the capillary channels already formed inside the sludge filter cakes by shear stress, so as to keep sludge granules in a relatively loose state and having larger specific surface area to benefit the subsequent aerobically air-drying process. {circle around (2)}. The higher the overturning speed is, the more output the sludge crushing and dispersing apparatus has, and vice versa. Preferably, the overturning speed during the crushing and dispersing of sludge filter cakes is that the linear velocity at the outermost radial point is between 5 mm/s and 100 mm/s.
[0012] The dry air is produced as follows. Refrigerants absorb heat in the cold exchanger and release heat in the heat exchanger under the influence of the compressor. Normal temperature air extracted by the air blower is first cooled to precipitate condensed water in the cold exchanger wherein the temperature for cooling is between 0° C. and 15° C. And then the temperature of the air is raised to a range of 0° C. to 90° C. in the heat exchanger. Accordingly, the unsaturation of the air is raised, resulting in the dry air.
[0013] Said aerobically exothermic reaction is a process that under oxidative conditions aerobic bacteria in the sludge decompose organics into carbon dioxide and water, accompanying with heat releasing. With the steps of crushing and dispersing of sludge filter cakes and blowing dry air, the heat aerobically released from the sludge is in a range of from 0 to 20 KJ·kg −1 ·h −1 , depending on the content of organics in the sludge.
[0014] The aerobically exothermic drying of the sludge itself is a sterilizing process against pathogens in the sludge. Additional physically or chemically sterilizing of sludge granules, which is selected from the group consisting of ultraviolet sterilization, ozone sterilization, high chlorine- or high oxygen-materials sterilization as well as other sterilization, may be further adopted to meet the needs of sludge reclamation.
[0015] In the step of washing the tail gas, the condensed water discharged from the cold exchanger is preferably used as the source of water, and with supplementary from external water resources.
[0016] In the step of further pulverizing the dried sludge granules during the conveying of the dried sludge granules with the screw crushing device by making the materials crushing and rubbing with each other, the device may have a single screw or a set of two or more screws.
[0017] Also provided is an apparatus for low temperature air-drying sludge filter cakes, comprising means for pre-crushing sludge filter cakes, means for air-drying the sludge and means for producing dry air. The means for pre-crushing sludge filter cakes is disposed above the means for air-drying sludge. A feed inlet is disposed over the means for pre-crushing sludge filter cakes. The means for air-drying the sludge include a conveyor belt and a driving device. Both ends of the conveyor belt connect the respective driving devices. The conveyor belt is arranged in multiple-layer mode. The means for discharging and crushing is disposed blow the bottom layer of the conveyor belt. A discharging outlet is at the end of the means for discharging and crushing. The means for producing dry air is disposed over the means for air-drying the sludge and connected with the air outlets in the means for air-drying the sludge through air channels.
[0018] The conveyor belt mentioned above may have four or more layers.
[0019] A sludge thickness regulator may be set at the starting end of the first layer of the conveyor belt.
[0020] Ultraviolet lamps may be set on the walls corresponding to the ends of the conveyor belt.
[0021] Compared with the prior art technologies, this invention has following advantages. First, the crushing and dispersing of the sludge filter cakes into a layer of sludge granules before the drying step leads to sludge granules having high specific surface area, which are more efficient in heat conducting and mass transferring when drying and thereby make the drying less energy consumption. Second, the crushed sludge granules experience aerobically exothermic reactions, which not only decrease the energy consumption for drying, but also accelerate drying speed and achieve the sludge deodorization. Third, during the drying, the sludge granules move at a relatively slower speed, producing no dust, which makes the process more stable and safer. Fourth, due to the low temperature drying of sludge leads to no thermal cracking reaction of organics, the dried tail gases after washing step may meet the environment-friendly discharging standards. Fifth, the means for discharging and crushing has additional function of crushing, which may loosen resulting sludge granules, making them easier for reclamation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic flowchart illustrating the method of aerobically air-drying sludge filter cakes in accordance with one embodiment of this invention.
[0023] FIG. 2 is a schematic illustration of the apparatus for aerobically air-drying sludge filter cakes in accordance with one embodiment of this invention.
[0024] FIG. 3 is a schematic illustration of the cross section at A-A of the apparatus for aerobically air-drying sludge filter cakes in accordance with one embodiment of this invention.
[0025] FIG. 4 is a schematic illustration of the cross section at B-B of the apparatus for aerobically air-drying sludge filter cakes in accordance with one embodiment of this invention.
[0026] FIG. 5 is an enlarged illustration of the C section of the apparatus for aerobically air-drying sludge filter cakes in accordance with one embodiment of this invention.
[0027] In the figures, the reference sign 1 represents the feed inlet; the reference sign 2 represents the means for crushing and dispersing sludge filter cakes; the reference sign 3 represents the induced draft fan; the reference sign 4 represents the overflow orifice; the reference sign 5 represents the tail gas washing device; the reference sign 6 represents the heat exchanger; the reference sign 7 represents the air blower; the reference sign 8 represents the cold exchanger; the reference sign 9 represents the air inlet; the reference sign 10 represents the condensed water pump; the reference sign 11 represents the dry-air inlet; the reference sign 12 represents the conveyor belt; the reference sign 13 represents the sludge thickness regulator; the reference sign 14 represents the mudguard; the reference sign 15 represents the driving device; the reference sign 16 represents the means for discharging and crushing; the reference sign 17 represents the discharging outlet; the reference sign 18 represents the dry air channel; the reference sign 19 represents the ultraviolet lamps; the reference sign 20 represents the mesh belt; and the reference sign 21 represents the connecting pin.
DESCRIPTION OF THE INVENTION
[0028] The method and apparatus for aerobically air-drying sludge filter cakes are described in the following section of this specification by making reference to the drawing figures and the illustrated examples.
[0029] The method for aerobically air-drying sludge filter cakes as showed in FIG. 1 comprises steps of:
[0030] (1) crushing and dispersing the sludge filter cakes into a layer of sludge granules to enlarge the specific surface area of the sludge. The above crushing and dispersing of the sludge filter cakes is accomplished by overturning the sludge filter cakes with a moisture content of 50% to 70% in a porous or interstitial cage and crushing the sludge filter cakes via the attrition and collision therebetween. The sludge granules with external diameters less than those of the pore or the gap distances of the cage breakthrough the cage and thereby the step of the crushing and dispersing of sludge filter cakes is accomplished. The diameters of the pore or the gap distances are set between 3 mm and 30 mm. The resulting sludge granules within the range, when free settled, have a relatively small bulk density, which may facilitate the gas in and out. The overturning of sludge filter cakes in the cage may be driven by the screw inside the cage or the rotation of the cage per se. The speed of overturning sludge filter cakes in the cage is adjusted according to moisture content of sludge filter cakes and output remand according to the following regulars: {circle around (1)}. The higher moisture content of sludge filter cakes is, the lower the overturning speed is, and vice versa. The most importance is to minimize the destruction of the capillary channels already formed inside the sludge filter cakes by shear stress, so as to keep sludge granules in a relatively loose state and having larger specific surface area to benefit the subsequent aerobically air-drying process. {circle around (2)}. The higher the overturning speed is, the more output the sludge crushing and dispersing apparatus has, and vice versa. Preferably, the overturning speed during the crushing and dispersing of sludge filter cakes is that the linear velocity at the outermost radial point is between 5 mm/s and 100 mm/s.
[0031] (2) blowing with positive pressure dry air at a certain temperature into the layer of sludge granules moving at low speed or overturned so that the sludge granules experience aerobically exothermic reactions, which make moisture rapidly evaporated from sludge granules and moved to the dry air by mass transferring under the effect of both the external heat and internal heat. Said aerobically exothermic reaction is a process that under oxidative conditions aerobic bacteria in the sludge decompose organics into carbon dioxide and water, accompanying with heat releasing. With the steps of crushing and dispersing of sludge filter cakes and blowing dry air, the heat aerobically released from the sludge is in a range of from 0 to 20 KJ·kg −1 ·h −1 , depending on the content of organics in the sludge. The dry air is produced as follows. Refrigerants absorb heat in the cold exchanger and release heat in the heat exchanger under the influence of the compressor. Normal temperature air extracted by the air blower is first cooled to precipitate condensed water in the cold exchanger wherein the temperature for cooling is between 0° C. and 15° C. And then the temperature of the air is raised to a range of 0° C. to 90° C. in the heat exchanger. Accordingly, the unsaturation of the air is raised, resulting in the dry air. A restrictor is disposed between the cold exchanger and the heat exchanger, which may be a throttle valve. Condensed water produced in the cold exchanger is pumped into the tail gas washing device.
[0032] (3) Physically or chemically sterilizing the sludge granules moving at low speed or overturned. Though the aerobically exothermic drying of the sludge itself is a sterilizing process against pathogens in the sludge, additional physically or chemically sterilizing of sludge granules, which is selected from the group consisting of ultraviolet sterilization, ozone sterilization, high chlorine or high oxide materials sterilization as well as other sterilization, may be further adopted to meet the needs of sludge reclamation.
[0033] (4) Pumping out tail gas by negative pressure from the layer of sludge granules, washing and then discharging. The source of water for washing may preferably be the condensed water discharged from the cold exchanger. External water resources may be used to provide supplementary.
[0034] (5) Further pulverizing the dried sludge granules to meet the reclamation requirements.
[0035] The further pulverizing is accomplished during the conveying of the dried sludge granules with a screw crushing device by making the materials crushing and rubbing with each other. The device may have a single screw or a set of two or more screws. The reclamation mentioned above may be use as fertilizers, in bricks manufacture, as fuels and as fillers.
Example 1
[0036] The method for aerobically air-drying sludge filter cakes was carried out, which includes the steps of:
[0037] (1) Crushing of sludge filter cakes with a moisture content of 70%-50% into sludge granules, which were fell onto the moving conveyor belt and thereby dispersed into a layer of sludge granules, wherein said crushing of sludge filter cakes was done by the means for crushing sludge filter cakes mentioned below.
[0038] (2) Blowing with positive pressure dry air at a certain temperature into the layer of sludge granular on the conveyor belt moving at low speed. The dry air was produced by subjecting normal temperature air to condensing and separating moisture in the cold exchanger and warming up in the heat exchanger. The dry air had a temperature of 0-90° C. The dry air was blow through the air channels to the dry air inlets which are disposed between the steel meshes of the upper and lower layers of the conveyor belt. Upon crossing from the bottom and the top of sludge granules, the dry air provided oxygen to aerobic reactions as well as dewatered the sludge granules by taking away moisture therefrom. The conveyor belt was designed to have several layers, on the top layer of which a sludge granules thickness regulator was set. Thickness of sludge granules on the conveyor belt was regulated to a range of between 10 mm and 500 mm. The linear velocity of the conveyor belt was 1 mm/s-10 mm/s. The entire residence time of sludge granules on the conveyor belt was 5 h-50 h. The sludge granules sent to the end of the upper layer of the conveyor belt fell down onto the lower layer and moved towards the opposite direction.
[0039] (3) Physically or chemically sterilizing sludge granules on the conveyor belt. Preferably, the sludge granules were sterilized by radiation by ultraviolet lamps when the sludge granules falling down to the lower layer.
[0040] (4) Pumping out tail gas by negative pressure from the layer of sludge granules, washing and then discharging. The source of water for washing was the condensed water discharged from the cold exchanger. External water resources were used to provide supplementary.
[0041] (5) When sending to the end, the sludge granules on the bottom layer of the conveyor belt falling down to the spiral crushing device below the bottom layer of the conveyor belt to be further crushed.
[0042] The above was carried out in an apparatus for aerobically air-drying sludge filter cakes. As showed in FIGS. 2 , 3 , 4 and 5 , the apparatus includes the means for crushing and dispersing sludge filter cakes 2 , the means for aerobically air-drying the sludge, the means for discharging and crushing, the means for producing dry air, the means for collecting and washing tail gas.
[0043] The means for crushing and dispersing sludge filter cakes 2 was disposed over the means for aerobically air-drying the sludge. An inlet 1 for sludge filter cakes was disposed over the means for crushing and dispersing sludge filter cakes. In the means for crushing and dispersing sludge filter cakes 2 , sludge filter cakes were crushed to sludge granules. Then the sludge granules fell down through a discharging port onto the top layer of the conveyor belt 12 within the means for aerobically air-drying the sludge. Beneath the discharging port of the means for crushing and dispersing sludge filter cakes 2 , a mudguard 14 was set on the beginning of the top layer of conveyor belt 12 to make sure that all the sludge granules from the discharging port were falling onto the top layer of the conveyor belt 12 . The means for crushing and dispersing sludge filter cakes 2 comprised a screw, a cage, a screw driving motor and a house. The screw driving motor was connected to the screw with a connector. There were crushing blades on the screw. The screw was surrounded by the cage which was surrounded by the house. The cage was porous or interstitial. The screw was set on a bearing which is disposed on main supports. The feed inlet was on the middle of the house. The cage was fixed on the main supports by a connecting support. The diameter of the pore or the gap distances of the cage was between 3 mm and 30 mm and the interstices area ratio or the porosity was 50%-99%. The house was a conical shell for collecting materials. The crushing blades were arranged on the end of the screw in an angle which causes the reversing propulsion so that sludge filter cakes were driven to the crushing cage to make sure that all the sludge filter cakes were crushed and brokethrough from the pores or the interstices on the cage. A cage cleaning device was set on the crushing blades and prevented the pores or the interstices on the cage from being blocked. The crushing blades had an outmost point linear velocity of 5 mm/s-100 mm/s.
[0044] The means for aerobically air-drying the sludge comprised conveyor belt 12 , driving device 15 , sludge thickness regulator 13 and ultraviolet lamps 19 . Both ends of the conveyor belt were connected to driving device 15 , which drove conveyor belt 12 through an axle and a speed regulating motor. The mesh belt 20 of the conveyor belt 12 was set on chains which were linked by connecting pins 21 . A sludge thickness regulator 13 was set on top of the conveyor belt 12 to regulate the thickness of sludge granules on the conveyor belt 12 , for high drying efficiency. Thickness of sludge granules was controlled between 10 mm and 500 mm. Conveyor belt 12 was layered from top to bottom, for example as four or more layers. One layer of the conveyor belt moved towards the opposite direction of the adjacent layers. The conveyor belt was made from any materials that were able to bear and ventilate, such as steel mesh, filter cloth and/or plastic mesh. The lower layer of the conveyor belt exceeded the upper one at one end so that sludge sent to the end of the upper layer of the conveyor belt fell down onto the lower one that was moving in the opposite direction. During sludge falling down, they were exposed to and sterilized by ultraviolet lamps 19 that were set on the wall opposite to the ends of each layer of the conveyor belt. The means for discharging and crushing 16 was disposed on the bottom of the means for air-drying the sludge. The discharging outlet 17 was disposed on the end of the means for discharging and crushing 16 . Dried sludge on the bottom layer of the conveyor belt 12 fell down onto the means for discharging and crushing 16 , crushed when advancing along the means for discharging and crushing 16 and discharged from the discharging outlet 17 at last. The means for discharging and crushing 16 could be a twin screw conveyor with at least one crushing screw. Preferably, the means for discharging and crushing 16 had two crushing screws.
[0045] The means for producing dry air was disposed over the means for aerobically air-drying the sludge. The means for producing dry air comprised a cold exchanger, a compressor, an air blower and a heat exchanger. Air blower 7 was between the cold exchanger 8 and the heat exchanger 6 . The cold exchanger 8 was connected to the air inlet 9 . Water condensed in the cold exchanger 8 was separated by a condensate separator, collected and then sent to the tail gas washing device 5 by condensed water pump 10 . Through dry-air channel 18 , the dry air was sent to the dry-air inlet 11 within conveyor belt 12 to dry the sludge granules on the conveyor belt 12 . Dry-air inlet 11 could blow upward and downward.
[0046] The means for collecting and washing tail gas was disposed over the means for aerobically air-drying the sludge. The means for collecting and washing tail gas included induced draft fan 3 and tail gas washing device 5 . Induced draft fan 3 connected at its air inlet to the means for crushing and dispersing sludge filter cakes 2 and at its outlet to tail gas washing device 5 by the air channels. Washed tail gas was discharged from the exhaust pipe on the top of tail gas washing device 5 , while the waste water was pumped out from overflow orifice 4 in the middle of tail gas washing device 5 .
[0047] Sludge filter cakes with moisture content of 70%-50% were feed from the feed inlet 1 to the means for crushing and dispersing sludge filter cakes 2 . Crushed sludge granules fell onto the steel mesh of the conveyor belt 12 , whose linear velocity was set between 1 mm/s˜10 mm/s. Thickness of the sludge granules on the steel mesh of the conveyor belt 12 was controlled in a range of 10 mm˜500 mm by the sludge thickness regulator 13 . Sludge granules sent to the end of a layer of the conveyor belt fell down onto the lower one that was moving in the opposite direction, during which falling the sludge granules was exposed to and sterilized by the ultraviolet lamps 19 set on the wall opposing to the ends of each layer of the conveyor belt, which was repeated. At last sludge fell down onto the means for discharging and crushing 16 , crushed when advancing, and discharged from the discharging outlet 17 set at the end of the means for discharging and crushing 16 . By adjusting the speed of the conveyor belt, residence time of sludge granules in the means for aerobically air-drying the sludge was controlled in 5 h-50 h and the moisture content of the resulting materials was controlled in 50%-5%.
[0048] Normal temperature air was sent through the air inlet 9 to the cold exchanger 8 in the means for producing dry air where its moisture was condensed and separated, then pumped by air blower 7 to the heat exchanger 6 where it was warmed up and became the unsaturated dry air. The temperature of the dry air was adjusted to a range of from 0 to 90° C. Condensed water was discharged from the condensate separator in the cold exchanger 8 and then sent by the condensed water pump 10 to tail gas washing device 5 as the water source for washing. Through air channels 18 , the dry air was sent to each dry air outlet 11 which was between the upper and lower steel mesh of the conveyor belt 12 , to provide dried and aerobic air for the sludge granules thereon. There were several dried air outlets 11 over each layer of the conveyor belt 12 . Sludge granules were subjected to a heat conducting and mass transferring with the dry air and got dewatered. Through the induced draft fan 3 , the dried tail gas was collected by the means for crushing and dispersing sludge filter cakes 2 , pumped into the tail gas washing device 5 and discharged after bubbling washing. The sewage in the washing was pumped into the sewage pipe from the overflow orifice 4 .
Example 2
[0049] Sludge filter cakes with a moisture content of 70% were feed from the feed inlet to the means for crushing and dispersing sludge filter cakes 2 . Crushed sludge granules fell to the steel mesh of the conveyor belt 12 in the means for aerobically air-drying the sludge. The linear velocity of the conveyor belt 12 was set at 1.5 mm/s. Thickness of the sludge granules on the conveyor belt 12 was about 50 mm. Sludge granules sent to the end of a layer of the conveyor belt fell down onto the lower one that was moving in the opposite direction, during which falling the sludge granules was exposed to and sterilized by the ultraviolet lamps 19 , which was repeated. The temperature of the dry air was 62° C. The dry air was sent through air channels 18 to each dry air outlet 11 which was between the upper and lower layers of the steel mesh conveyor belt 12 , to provide dry air for the sludge granules thereon. The dried sludge granules fell down onto the means for discharging and crushing 16 which was disposed blow the means for aerobically air-drying the sludge, crushed when advancing, and discharged from the discharging outlet 17 set at the end of the means for discharging and crushing 16 . The moisture of the resulting materials was 38%. The residence time of sludge granules in the means for aerobically air-drying the sludge was 35 h. After storing for 3 days, moisture content of packed dried sludge decreased to 35%.
Example 3
[0050] Sludge filter cakes with moisture content of 62% were feed from the feed inlet to the means for crushing and dispersing sludge filter cakes 2 . Crushed sludge granules fell to the steel mesh of the conveyor belt 12 in the means for aerobically air-drying the sludge. The linear velocity of the conveyor belt 12 was set at 3 mm/s. Thickness of the sludge granules on the steel mesh of the conveyor belt 12 was about 80 mm. Sludge granules sent to the end of a layer of the conveyor belt fell down onto the lower one that was moving in the opposite direction, during which falling the sludge granules was exposed to and sterilized by the ultraviolet lamps 19 , which was repeated. The temperature of the dry air was 55° C. The dry air was sent through air channels 18 to each dry air outlet 11 which was between the upper and lower layers of the steel mesh conveyor belt 12 , to provide dry air for the sludge granules thereon. The dried sludge granules fell down onto the means for discharging and crushing 16 which was disposed blow the means for aerobically air-drying the sludge, crushed when advancing, and discharged from the discharging outlet 17 set at the end of the means for discharging and crushing 16 . The moisture of the resulting materials was 33%. The residence time of sludge granules in the means for aerobically air-drying the sludge was 28 h.
Example 4
[0051] Sludge filter cakes with moisture content of 54% were feed from the feed inlet to the means for crushing and dispersing sludge filter cakes 2 . Crushed sludge granules fell to the steel mesh of the conveyor belt 12 in the means for aerobically air-drying the sludge. The linear velocity of the conveyor belt 12 was set at 5 mm/s. Thickness of the sludge granules on the steel mesh of the conveyor belt 12 was about 110 mm. Sludge granules sent to the end of a layer of the conveyor belt fell down onto the lower one that was moving in the opposite direction, during which falling the sludge granules was exposed to and sterilized by the ultraviolet lamps 19 , which was repeated. The temperature of the dry air was 52° C. The dry air was sent through air channels 18 to each dry air outlet 11 which was between the upper and lower layers of the steel mesh conveyor belt 12 , to provide dry air for the sludge granules thereon. The dried sludge granules fell down onto the means for discharging and crushing 16 which was disposed blow the means for aerobically air-drying the sludge, crushed when advancing, and discharged from the discharging outlet 17 set at the end of the means for discharging and crushing 16 . The moisture of the resulting materials was 31%. The residence time of sludge granules in the means for aerobically air-drying the sludge was 22 h.
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A method for aerobically air-drying sludge cakes is provided. The method comprises: crushing and dispersing sludge filter cakes into a layer of sludge granules, blowing with positive pressure dry air into the layer of sludge granules moving at low speed or overturned so that the sludge granules experience aerobically exothermic reactions, which make moisture rapidly evaporated from sludge granules and moved to the dry air by mass transferring under the effect of both the external heat and internal heat, physically or chemically sterilizing the sludge granules moving at low speed or overturned, pumping out tail gas by negative pressure from the layer of sludge granules, washing and then discharging, and further pulverizing the dried sludge granules to reach the reclamation requirements. At the same time, an apparatus for carrying out the method is also provided. The method is high in heat conducting and mass transferring efficiency when drying and low in energy consumption for drying. It accelerates the drying speed. The sludge granules can be stably and safely processed during the drying. In addition, the dried tail gas can meet the environment-friendly discharge standard, and the output sludge is good for sludge reclamation.
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BACKGROUND OF THE INVENTION
[0001] 1. Field Of The Invention
[0002] The present invention relates to wind turbines, and more particularly, to transporting wind turbines on railroad cars.
[0003] 2. Background
[0004] Wind turbines are used to generate electrical power, and conventional wind turbine 1 is illustrated in FIG. 1 . The turbine 1 is mounted on the ground 5 and includes a tower 6 comprised of a plurality of sections with a nacelle 10 mounted on top. A rotor 12 is affixed to the front of the nacelle 10 and blades 14 are connected to the rotor 12 . The tower 6 is comprised of sections including base member 16 , intermediate members 17 and a top member 18 .
[0005] Turning now to FIG. 2 the components of nacelle 10 of a conventional wind turbine 1 are illustrated. The nacelle 10 is rotatably mounted on the upper flange 15 of the top tower member 18 through a bearing 19 having an inner race and outer race connected to flange 15 . The inner race of the bearing 19 is connected to an annular nacelle mounting plate 20 having a larger diameter than the outer diameter of the top tower member 18 .
[0006] The nacelle 10 has a cylinder-like configuration extending horizontally and both ends are closed. The nacelle 10 includes a front nacelle section 21 A and a rear nacelle section 21 B. The nacelle 10 has holes 22 and 23 disposed opposite to each other on the upper and lower surfaces thereof, respectively. The hole 22 provided on the upper surface of the nacelle 10 is closed by a lid 22 a , after the nacelle 21 is mounted on the tower 6 .
[0007] A front supporting member 24 and rear supporting member 25 are installed on the floor surface of the front nacelle section 21 a and rear nacelle section 21 b . The respective supporting members 24 , 25 are connected through a plurality of L-shaped mounting members 26 with the mounting plate 20 . In the front nacelle section 21 A a rotation shaft 32 for supporting a rotor hub 31 , a bearing box 33 for supporting the rotation shaft 32 , a gear box 34 for changing the revolution speed of the rotation shaft 32 , a brake 35 and a shaft 36 , are disposed.
[0008] In the rear nacelle section 21 B a generator 37 connected to the shaft 36 , a controller 38 , and hydraulic power sources 39 are disposed. A drive shaft 40 is disposed between the gear box 34 and the generator 37 to transmit power from the gear box 34 to the generator 37 . A yaw motor 41 is mounted on the nacelle mounting plate 20 in order to rotate the nacelle 10 . An output shaft of the yaw motor 41 is provided with a drive gear (not shown) and the drive gear meshes with the gear formed on the outer periphery of the outer race of the bearing 19 so that the rotation of the yaw motor 41 adjusts the direction of the nacelle 10 .
[0009] Various components of a wind turbine are often manufactured in different parts of the world and then transported to a site and assembled and erected at the site. As one example, a manufacturer who wishes to assemble a tower in the United States may have the towers manufactured in Korea, the nacelles manufactured in Denmark and the blades manufactured in Germany. The components are shipped by ocean liners to the US and then loaded onto railroad cars and/or trucks for transportation to the assembly site where they are erected. Some types of wind turbines are relatively large structures which have some fragile components, and therefore they must be transported carefully to avoid damage.
[0010] Cargo containers, sometimes called intermodal containers, are commonly used for transportation of goods by a variety of methods. Such cargo containers are designed for shipment by ship, railroad and truck so that the cargo can be packed into the container at the beginning of the trip and then transported to the destination by more than one mode of transportation with out the need to load and unload the container when changing from one transportation mode to another. A conventional intermodal cargo container is taught in U.S. Pat. No. 4,782,561.
[0011] As described in U.S. Pat. No. 4,782,561 the intermodal cargo containers each have eight corners, and mounted on each corner is a corner fitting which includes three standard sized and shaped slots, one at each face of the container. The corner fittings cooperate with twist locking devices which enable a user to connect and disconnect the corners of a container to corresponding corners of another container thus permitting two containers to be connected to one another in a stable manner during transit and then disconnected from each other as required.
SUMMARY OF THE INVENTION
[0012] The system is used to transport wind turbines on railroad cars. The wind turbines are partially disassembled into four types of components—nacelles, blades, rotor hubs, and tower sections. The blades are stored in cargo containers suitable for use in multi-mode transportation of freight by ship, rail and truck. The nacelles and rotor hubs are not stored in containers but are affixed to transport structures. Brackets are affixed to the tower sections. Then the components are mounted on the decks of railroad cars.
[0013] The cargo containers are of standard construction, having a standard corner fitting at each corner thereof. The transport structures have holes in their ends. The railroad cars have brackets and stops welded thereto for cooperation with the standard corner fittings and with the holes in the transport structures.
[0014] Conventional twist lock connectors are installed in brackets located on a railroad car. Then the containers are lowered onto the railroad cars with their corner fittings aligned with the twist lock connectors, and the connectors are engaged with the corner fittings to form a secure connection. The nacelles with their transport structures are lowered onto the railroad cars so that the holes on the transport structures are aligned with the holes in the brackets, and then a pin is installed to connect them together. Once these connections have been made the railroad cars can be moved.
[0015] It is an object of the present invention to provide a system and process for transporting a wind turbine by railroad efficiently and at reduced cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a conventional wind turbine.
[0017] FIG. 2 shows the interior of the nacelle of a conventional wind turbine.
[0018] FIG. 3 is an elevation view of one embodiment of the present invention, showing tower sections.
[0019] FIG. 4 is another elevation view of the embodiment shown in FIG. 3 .
[0020] FIG. 5 is a plan view of part of the system shown in FIG. 4 .
[0021] FIGS. 6-11 show components of the embodiment shown in FIG. 3 .
[0022] FIGS. 12-15 show components of a system for mounting a tower section on a rail car.
[0023] FIG. 16 shows an end view of a tower section mounted on a rail car.
[0024] FIGS. 17-18 show conventional twist locks which can be used with the embodiments shown in FIGS. 3-16 .
[0025] FIG. 19 shows a preferred embodiment for transporting blades, broken into three sections.
[0026] FIG. 19 a shows the embodiment of FIG. 19 in operation.
[0027] FIG. 20 shows an end view of the embodiment of FIG. 19 .
[0028] FIG. 21 shows a plan view of part of the system of FIG. 19 .
[0029] FIGS. 22-25 show details of the system of FIG. 19 .
[0030] FIG. 26 shows a preferred embodiment for transporting nacelles.
[0031] FIGS. 27-32 show details of the system of FIG. 26 .
[0032] FIGS. 33-37 show elevation views of railroad cars with tower sections in accordance with another embodiment of the present invention.
[0033] FIG. 38 shows a plan view of the deck of a railroad car configured according to the embodiment shown in FIGS. 33-37 .
[0034] FIGS. 39-44 show details of the embodiment shown in FIGS. 33-38 .
[0035] FIG. 45 shows an end view of a tower section.
[0036] FIG. 46 shows an elevation view of railroad cars in accordance with the embodiment shown in FIGS. 33-38 .
[0037] FIG. 47 shows a plan view of a system for transporting rotor hubs.
[0038] FIG. 48 shows an elevation view of the device of FIG. 47 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Turning to FIGS. 3-16 , the railroad transportation system for the tower sections is illustrated. With reference to FIGS. 3 and 4 , bottom tower sections 50 and top tower sections 52 are located on railroad cars 54 . It should be noted that the tower sections are substantially cylindrical and the bottom tower sections 50 are roughly half the length of the top tower sections 52 . Middle tower sections are not shown since they are similar in length to the top sections 52 and are transported in the same way as the top tower sections 52 . The tower sections 52 and 50 are connected to the rail cars 54 by mounting systems 56 and 58 which will be further described below.
[0040] With reference to FIG. 5 it can be understood that there are two types of mounting systems, a first type 56 and a second type 58 . The first type of mounting system 56 includes two short deck slot pedestals 59 and four end stops 62 , each of which is welded to the deck of the rail car 54 near one end of the car 54 . The second type of mounting system 58 is located near the end of the rail car opposite the first type of mounting system 56 , and the second type 58 includes four deck slot pedestals 60 , each of which is welded to the deck of the rail car 54 .
[0041] Turning to FIGS. 6-8 , details of the deck slot pedestals 60 are shown. Each deck slot pedestal 60 comprises a substantially box like structure having four sides 70 and a top 72 . A slot 74 is formed in the top 72 and is shaped and sized to cooperate with a standard twist lock 100 . The slot 74 is considerably longer than necessary to accommodate a twist lock 100 so that the twist lock can be located in different positions along the length of the slot depending on the length of the tower section to be mounted to the pedestal 60 . On the other hand, the short deck slot pedestals 59 are shorter than pedestals 60 because the end of the tower section affixed to the short deck slot pedestals 59 is constrained in its location by the end stops 62 .
[0042] There are a number of designs for standard twist locks, and one twist lock 100 which can be used with the present embodiment is taught in U.S. Pat. No. 4,782,561, the teachings of which are incorporated herein by reference. Turning to FIGS. 17 and 18 the twist lock 100 described in U.S. Pat. No. 4,782,561 includes a body 110 with a first projection 112 and a first lock 114 mounted above the first projection 112 . A second projection 116 is connected to the body 110 and a second lock 118 is mounted below the second projection 116 . A handle 120 is connected to the body and to the first and second locks 114 and 116 to enable a user to operate the locks 114 and 116 . In use, the user can engage the upper and lower locks with corresponding slots in a cargo container to connect cargo containers to one another.
[0043] Turning to FIGS. 9-11 , details of end stops 62 are shown. Each end stop 62 comprises a flat base 76 , a vertical member 78 having a curved upper portion and two supports 80 which are mounted to the base and to the vertical member.
[0044] Turning to FIGS. 12-14 , a bracket 82 is shown. The bracket 82 comprises a flat base plate 84 and a flat vertical member 86 welded to the base plate 84 and including five ports 88 . The ports 88 are substantially rectangular and have rounded ends. Two of the ports 88 have their long axes oriented horizontally and are located to the left side of the vertical member (as shown in FIG. 12 ); two of the ports have their long axes oriented horizontally and are located to the right side of the vertical member 86 , and one of the ports is located with its long axis oriented vertically in the middle of the vertical member 86 . Two twist lock coupling members 90 are located one at each end of the bracket 82 and are affixed to the vertical member 86 . Each twist lock coupling member 90 comprises a flat horizontal member 94 and two vertical members 96 which are substantially triangular in shape. Each twist lock coupling member 90 includes a port 92 which is substantially rectangular and has rounded ends. As shown in FIG. 12 , the ports 92 are shaped and sized to accommodate twist locks 100 . Moreover, as shown in FIG. 12 , it can be understood that the bracket 82 is sized and shaped so that when twist locks 100 are coupled to the ports 92 , the twist locks cooperate with the deck slot pedestals 60 .
[0045] In FIG. 5 the location of the base plate 84 is shown. As part of the first type of mounting system 56 the base plate 84 is located as shown. As part of the second type of mounting system 58 the base plate 84 can be located to cooperate with either of two sets of deck slot pedestals 60 , depending on the length of the tower section to be accommodated.
[0046] FIG. 15 shows the first type of mounting system 56 in which the end stops 62 are welded to the deck of the rail car 54 and the bracket 82 is located between the end stops 62 . It should be understood that in the second type of mounting system 58 there are no end stops 62 . Turning to FIG. 16 the bracket 82 is shown connected to a tower section 16 . It should be understood that each tower section 50 and 52 has a disc shaped flange 15 at each of its ends, and each flange 15 has a plurality of holes 102 located around its circumference so that tower sections can be bolted together. In the present transportation system the top tower section 50 is connected to the bracket 82 by three bolts 104 . There are no bolts through two of the ports 88 because the two ports are not used with tower section 50 but are used to accommodate top tower sections 52 which have a smaller diameter.
[0047] Turning now to FIGS. 19-25 the system for transporting blades 14 is illustrated. The system comprises four cargo containers, a first large cargo container 122 , a second large cargo container 123 , a first small cargo container 124 and a second small cargo container 126 connected end to end with each other. Two blades 14 are packed inside the four cargo containers.
[0048] The right end of the first small cargo container 124 and the left end of the first large cargo container 122 are mounted to the rail car 54 by a pedestal system 200 , and the right end of the second large cargo container 123 and the left end of the second small cargo container 126 are mounted to the rail car 54 by a second pedestal system 200 .
[0049] As best illustrated in FIG. 21 four pedestal systems 200 are welded to the deck of the rail car 54 near each corner of the deck. With reference to FIG. 22 , the coupling of the pedestal system to the cargo containers is shown. It should be understood that this figure illustrates the coupling of one corner of the right end of the first small cargo container 124 and the left end of the first large cargo container 122 , and the three other coupling systems are the same as the one illustrated. A standard corner member 202 is connected to each corner of the cargo containers 122 and 124 . Each corner member includes three ports 204 , only one of which is visible in this figure, it being understood that the other ports are substantially identical to those which are shown. The ports 204 are located so that they are aligned with the faces of the cargo containers, and the ports are of industry standard configuration to cooperate with standard twist locks 100 . A conventional twist tie 205 connects the two corner members 202 .
[0050] With reference to FIGS. 23-25 the pedestal system 200 comprises two connector boxes 206 and 208 which are substantially cube shaped and include ports. Connector box 206 includes three ports 210 , 212 and 214 , and connector box 208 includes three ports 216 , 218 and 220 . The connector boxes 206 and 208 are identical to standard corner members 202 so that standard twist locks are compatible with the connector boxes 206 and 208 . The connector boxes 206 and 208 are welded to the top of an I beam 222 , and eight reinforcing members 224 are welded to the I beam 222 .
[0051] One of the advantages of the preferred embodiment can now be appreciated with reference to FIG. 19 a . It should be noted that railroad cars must be able to travel over uneven terrain and sometimes a car, in this example car 54 a , will be higher than an adjacent car, in this case car 54 b . This can result in the car 54 a being in relatively close vertical proximity to first small cargo container 124 . The pedestal system 200 is designed to insure that the car 54 a does not contact the small cargo container 124 . Similarly, when the cars travel around a turn the car 54 a will not be aligned with car 54 b . If the left end of the first small cargo container 124 were attached to car 54 a it would be difficult, if not impossible for the cars to make the turn. However, with the present system, this potential problem has been solved.
[0052] FIGS. 26-32 show the transport system for nacelles. In FIG. 26 two nacelles 10 are shown mounted on rail car 54 by a transport frame 230 and nacelle stops 232 . The nacelles 10 contain components such as those illustrated in FIG. 2 , including a bearing 19 to which the transport frame 230 is bolted. FIGS. 27 and 28 show the transport frame 230 , which includes two beams 234 and a plate 236 affixed to the tops of the beams 234 . A cylindrical member 238 is affixed to the top of the plate, and a plurality of bolts 240 are connected through a flange 241 the top of the cylindrical member 238 so that the bolts can be bolted to the bearing 19 of the nacelle. Four cylindrical holes 242 are formed, one in each end of each beam 234 to accommodate two rods 243 .
[0053] FIG. 29 shows the rail car 54 with nacelle stops 232 , two of which are attached near the ends of the rail car and two of which are attached near the middle thereof. FIGS. 30 and 31 show a nacelle stop 232 , which includes three plates members 244 and eight support members 246 . Two of the plate members 244 include cylindrical holes 248 which are sized and located to align with the holes 242 on the transport frame 230 . As shown in FIG. 32 , the transport frame 230 is connected to the nacelle stops 232 by a rod 243 inserted through holes 242 and 248 when the transport frame 230 and the nacelle stop 232 are aligned with each other.
[0054] Turning now to FIGS. 33-46 another embodiment of the present invention is shown. In this embodiment a system is provided to configure a rail car to be capable of carrying tower sections of a variety of sizes or to carry blades in cargo containers.
[0055] As discussed above, tower sections can be a variety of sizes. It is desirable to configure a rail car so that it is capable of carrying a tower section of any one of the sizes. In the particular embodiment discussed herein the tower sections have particular sizes for the purposes of this example, and it should be understood that the invention is equally applicable to tower sections of sizes different from those discussed herein. FIG. 33 shows the mounting system for a top tower section 250 , which is the longest section. FIG. 34 shows the mounting system for a middle tower section 252 , which is shorter than the top section 250 . FIG. 35 shows the upper base section 254 , which is shorter than the middle section 252 . FIG. 36 shows the lower base section 256 , which is shorter than the upper base section 254 . FIG. 37 shows the middle base section 258 , which is shorter than the lower base section 256 . In FIGS. 33-37 the rail car 260 is configured in the same way, as will be described with reference to FIG. 38 .
[0056] FIG. 38 shows the deck of the rail car 260 in plan view, and, for reference purposes, the rail car will be said to have a left end 262 , a right end 264 , a front side 266 and a back side 268 . A first pedestal system 270 is welded to the deck of the rail car 260 near the back, left corner, and a second pedestal system 272 is welded to the deck near the front, left corner. The pedestal systems 270 and 272 are the same in configuration as pedestal systems 200 discussed above. Between the pedestal systems 270 and 272 , a fixed riser assembly 274 is welded to the deck. The riser assembly 274 is described below. To the right of the fixed riser assembly 274 a first deck slot pedestal 276 is located near the back side of the deck, and a second deck slot pedestal 278 is located near the front of the deck. The deck slot pedestals 276 and 278 are the same configuration as short deck slot pedestals 59 , discussed above. Between the deck slot pedestals 276 and 278 four end stops 280 , 282 , 284 and 286 are welded to the deck. The end stops 280 - 286 are the same in configuration as the end stops 62 discussed above.
[0057] To the right of deck slot pedestals 276 , 278 four deck slot pedestals are mounted to the deck, two of which, 290 and 292 are mounted near the back and two of which, 294 and 296 are mounted near the front. Deck slot pedestals 290 - 296 are similar in construction to deck slot pedestals 60 discussed above. To the right of deck slot pedestals 290 - 296 , two deck slot pedestals 300 and 302 are mounted near the front and the back of the rail car respectively. To the right of the deck slot pedestals 300 and 302 a floating riser system 304 is welded to the deck of the car 260 , near the right end.
[0058] The fixed riser system 274 and the floating riser system 304 are shown in FIGS. 39-41 and 42 - 44 , respectively. The fixed riser system 274 comprises two steel beams 306 having C-shaped cross sections and located parallel to each other and connected to each other by three plates 308 . Two plates 310 are welded to the tops of the beams 306 , and two I-beams 312 are welded, one to each of the beams 306 to form a substantially cross-shaped structure. The floating riser system 304 comprises two steel beams 314 having C-shaped cross sections and located parallel to each other and connected to each other by four plates 316 . Two I-beams 318 are welded, one to each of the beams 314 , and two I beams 320 are welded, one to each of the beams 314 . At the ends of the I beams 318 are affixed deck slot pedestals 322 and at the ends of the I beams 320 are affixed deck slot pedestals 324 . The deck slot pedestals 322 are the same as deck slot pedestals 60 , and pedestals 324 are similar in construction to deck slot pedestals 60 , except that the deck slot pedestals 324 are longer than the pedestals 322 .
[0059] Turning now to FIG. 45 , the system for mounting a tower section to the rail car is shown. The system shown in FIG. 45 is similar to that shown in FIG. 16 . However, in FIG. 45 the fixed end riser 274 is included and no end stops 62 are included. It should be understood that the system for mounting a tower section to a floating end riser 340 is substantially the same as the system shown in FIG. 45 .
[0060] Turning again to FIGS. 33-37 the system for mounting the towers can now be appreciated. FIG. 33 shows the top tower section 250 , which is the longest section, with its left end coupled to the first and second pedestal systems 270 and 272 by twist locks. The base plate 84 sits atop the fixed riser 274 , and the base plate 84 is located between the two plates 310 in the position indicated by dashed lines 350 ( FIG. 38 ) so that the plates 310 prevent motion of the tower in the direction extending between the left and right ends of the rail car. The right end of tower section 250 is coupled to the deck slot pedestals 324 of the floating riser system 304 by twist locks. It should be noted that the long slots in the deck slot pedestals 324 allow for variations in tower length. It should also be understood that conventional rail cars are often made with a deck which is not flat but which is slightly higher in the middle than at its left and right ends so that when loads are mounted on the car, slight sagging in the middle results in a relatively flat car. As cars age the extent of the height differential between the middle and the ends normally decreases. Accordingly it can be seen that the present mounting system which raises the ends of the tower section, thus permits the tower to be carried securely on conventional, slightly bowed rail cars.
[0061] FIG. 34 shows the middle tower section 252 , which is shorter than the top section 250 , mounted similarly to the top section 250 except that the right end of the tower section 252 is coupled to the deck slot pedestals 322 of the floating riser system 304 .
[0062] FIG. 35 shows the upper base section 254 , which is shorter than the middle section 252 , with its left end mounted to deck slot pedestals 276 and 278 as indicated by dashed lines 352 ( FIG. 38 ) and its right end mounted to deck slot pedestals 300 and 302 as indicated by dashed lines 354 .
[0063] FIG. 36 shows the lower base section 256 , which is shorter than the upper base section 254 , with its left end mounted to deck slot pedestals 276 and 278 as indicated by dashed lines 352 ( FIG. 38 ) and its right end mounted to deck slot pedestals 292 and 296 .
[0064] FIG. 37 shows the middle base section 258 , which is shorter than the lower base section 256 , with its left end mounted to deck slot pedestals 276 and 278 as indicated by dashed lines 352 ( FIG. 38 ) and its right end mounted to deck slot pedestals 290 and 294 .
[0065] Turning now to FIG. 46 a system for mounting blades in cargo containers to a rail car and for mounting rotor hubs to adjacent rail cars is shown. The blades are packed in cargo containers 122 , 123 , 124 and 126 as discussed above. The cargo containers are mounted to the rail car 260 by coupling the right end of the first small cargo container 124 and the left end of the first large cargo container 122 to the first and second pedestal systems 270 and 272 by twist ties. The left end of the second small cargo container 126 and the right end of the second large cargo container 123 are coupled to the deck slot pedestals 324 of the floating riser system 304 by twist ties.
[0066] To the left and right of rail car 260 are connected other rail cars 360 on which are mounted rotor hubs 31 . Turning to FIGS. 47 and 48 the system for mounting rotor hubs 31 is shown. The rotor mounting system 362 comprises a relatively flat deck section 364 to which is connected a cylindrical section 366 . At each corner of the deck section 364 is connected a twist tie connector 368 which includes a slot configured to cooperate with a standard twist tie. Standard twist ties 370 which have flat bases are welded to the deck of the rail car 360 to cooperate with the twist tie connectors 368 . A plurality of bolt holes 372 are formed in the top of the cylindrical section 366 so that a rotor hub 31 can be bolted to the rotor hub mounting system 362 .
[0067] While the invention has been described in detail with reference to preferred embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. All of the aforementioned documents are incorporated by reference in each of their entireties herein.
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A system is used to transport wind turbines on railroad cars. The wind turbines are partially disassembled into four types of components—nacelles, blades, rotor hubs and tower sections. The blades are stored in cargo containers suitable for use in multi-mode transportation of freight by ship, rail and truck. The nacelles and rotor hubs are not stored in containers but are affixed to transport structures. Brackets are affixed to the tower sections. Then the components are mounted on railroad cars.
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FIELD OF THE INVENTION
The present invention relates to a method and apparatus for separating air into nitrogen and oxygen-rich products by cryogenic distillation in which the air, after having been compressed and purified, is cooled to a temperature suitable for its distillation through indirect heat exchange with the nitrogen and oxygen-rich products within heat exchangers. More particularly, the present invention relates to such a method and apparatus in which a liquid oxygen stream is pumped and then vaporized in a separate heat exchanger through indirect heat exchange with part of the air that has been further compressed in a booster compressor.
BACKGROUND OF THE INVENTION
It is well known in the art to separate air into nitrogen and oxygen-rich products and also potentially an argon-rich product by cryogenic distillation. In accordance with such method, the air is compressed and purified and then cooled to a temperature suitable for its distillation within a heat exchanger against return streams that comprise the nitrogen and oxygen-rich products.
The separation of the air into the oxygen and nitrogen-rich products takes place within an air separation unit having higher and lower pressure columns that are operatively associated with one another in a heat transfer relationship, typically by a condenser-reboiler located at the bottom of the lower pressure column. The incoming air is rectified within the higher pressure column to produce a crude liquid oxygen column bottoms and a nitrogen column overhead that is condensed by the condenser-reboiler to reflux the higher pressure column. A stream of the nitrogen-rich liquid is also introduced into the top of the low pressure column to reflux the lower pressure column. A stream of the crude liquid oxygen is also introduced into the lower pressure column for further refinement and to produce an oxygen-rich liquid column bottoms in the lower pressure column that is vaporized by the condenser-reboiler. A waste nitrogen stream is withdrawn below the top of the lower pressure column together with a nitrogen-rich vapor column overhead that are introduced into a heat exchanger to cool the incoming air.
It is known to produce a high pressure oxygen product by pumping a liquid oxygen stream that is composed by the oxygen-rich liquid column bottoms and then vaporizing it in a heat exchanger against a stream of the compressed and purified air that has been further compressed by a booster compressor. The boosted pressure stream of air either liquefies or is converted into a dense phase fluid against vaporizing the pressurized liquid oxygen stream to produce the high pressure oxygen product. Additionally, it is also known that a nitrogen product composed of the nitrogen-rich liquid produced in the higher pressure column can also be pumped and vaporized in a like manner.
As mentioned above, an argon product can also be separated by withdrawing an argon-rich vapor stream from the lower pressure column and rectifying it in an argon column. The resulting liquid column bottoms is returned to the lower pressure column. The argon column is refluxed by condensing argon-rich column overhead in a condenser through indirect heat exchange with all or part of the crude-liquid oxygen stream before its introduction into the lower pressure column.
Although the above process and apparatus can utilize a single, main heat exchanger for cooling the incoming air streams through indirect heat exchange with the return streams that contain the oxygen-rich and nitrogen-rich products as well as the pressurized, pumped oxygen stream, it is also known to separately vaporize the pressurized oxygen product within a separate high pressure heat exchanger. Such process and apparatus are shown in Linde Reports on Science and Technology, “The Production of High-Pressure Oxygen”, Springmann (1980). In this paper it is also illustrated to utilize the waste nitrogen stream after having been used in subcooling duty as a feed to both the higher pressure heat exchanger that is used in vaporizing the pressurized and pumped liquid oxygen and also as a feed to the other heat exchanger that operates at a lower pressure to cool the main air stream to a temperature suitable for its rectification. This waste nitrogen feed to the heat exchangers is necessary for thermal balancing purposes. By “thermal balancing” what is meant is that the waste nitrogen streams decrease the difference between warm end temperatures of the streams exiting the lower pressure heat exchanger and the higher pressure heat exchanger to inhibit warm end losses of refrigeration by such heat exchangers and also to decrease the temperature difference of the boosted-pressure air stream and the main air stream at the cold end of the high pressure heat exchanger and the low pressure heat exchanger. In this way, the temperature difference between the boosted-pressure air stream and the pumped liquid oxygen stream at the cold end of the higher pressure heat exchanger can be optimized. It is advantageous to decrease the temperature difference at the cold end of the higher pressure heat exchanger in that the boosted pressure air liquefies within such heat exchanger and then thereafter, must be expanded for its introduction into at least the lower pressure column but also, potentially, the higher pressure column. If the temperature of this stream is too warm, vapor will evolve from the boosted pressure air during the expansion to effect the requisite distillation of the air to produce the desired products.
Brazed aluminum heat exchangers are used from both the higher and lower pressure heat exchangers. Such heat exchangers have a layered construction in which each of the streams, for example the incoming air stream, the nitrogen-rich stream and etc. pass through separate layers that are arranged in a pattern to efficiently conduct indirect heat exchange between the streams. The layered construction is produced in such heat exchangers by a series of parallel parting plates and peripheral side bars to seal the layers along their edges. Manifolds are provided to feed the streams into the layers. An arrangement of fins is provided in each of the layers that increase the area available for the heat exchange.
As can be appreciated, a high pressure heat exchanger for pumped liquid oxygen service in which typically the oxygen is to be supplied at 450 psia require air at a pressure of 1100 psia to vaporize the oxygen. Heat exchangers designed to handle such high pressures are more expensive than heat exchangers designed for lower pressure duty. For example, in case of brazed aluminum plate-fin heat exchangers, such heat exchangers require the use of reduced cross-sectional areas, have a very limited selection of heat transfer fins and require thicker design elements such as parting sheets and side bars as compared with a heat exchanger that operates at a lower pressure. All of this increases the cost of such heat exchangers that are designed to operate at high operational pressures such as is the case where a pressurized, pumped liquid oxygen stream is to be vaporized. Thicker materials and other known considerations would increase the costs of other types of heat exchangers such as like spiral wound, printed circuit and stainless steel plate-fin heat exchangers.
A spiral-wound heat exchanger is in general a tubular heat exchanger, wherein copper or aluminum tubes are wound round a central mandrel. The tubes and mandrel are enclosed in a pressure vessel shell. Each tube starts and ends in one of several tubesheets which are connected through the pressure vessel shell to headers. There will be one inlet and one outlet header for each stream in the heat exchanger.
If the operating pressure is high, these exchangers must utilize thicker tube walls to contain the pressure, which increases the quantity of material required. Hence spiral wound heat exchangers are more expensive if required to operate at higher pressure. Diffusion-bonded heat exchangers are constructed from flat metal plates into which fluid flow channels are either chemically etched or pressed.
Plates are then stacked and diffusion-bonded together by pressing metal surfaces together at temperatures below the melting point, to form a block. The blocks are then welded together to form the complete heat exchange core. Headers and nozzles are welded to the core in order to direct the fluids to the appropriate sets of passages. Design pressures up to 600 bara can be accommodated.
Higher design pressures are achieved in a printed circuit heat exchanger at the expense of smaller channels with thicker walls. To achieve the same pressure drop and heat transfer duty more material will be required—hence the heat exchanger is more expensive.
As will be discussed among other advantages of the present invention, a method and apparatus is provided for separating air in which fabrication costs of the higher pressure heat exchanger can be reduced by decreasing its size.
SUMMARY OF THE INVENTION
In one aspect, the present invention relates to a method of separating air. In accordance with the method, a first compressed and purified air stream and a second compressed and purified air stream are produced. The second compressed and purified air stream has a higher pressure than the first compressed and purified air stream. The first compressed and purified air stream and the second compressed and purified air stream are cooled in a lower pressure heat exchanger and a higher pressure heat exchanger, respectively, through indirect heat exchange with return streams generated in an air separation unit, thereby to produce a main feed air stream and a high pressure air stream that is either in a liquid or dense phase fluid state. In this regard, the term, “return streams” as used herein and in the claims means the oxygen-rich and nitrogen-rich streams that are separated from the air by rectification within the air separation unit. Additionally, the term “heat exchanger” means as used herein and in the claims either a single unit or a series of such units in parallel.
The main feed air stream is introduced into a higher pressure column of the air separation unit. The high pressure air stream is expanded and introduced at least in part into at least one of the lower pressure column or the higher pressure column of the air separation unit. The return streams comprise at least part of a pumped liquid oxygen stream composed of a liquid oxygen column bottoms of the lower pressure column that is introduced into the higher pressure heat exchanger and vaporized. Additionally, return streams also comprise first and second subsidiary waste nitrogen streams that are formed from a waste nitrogen stream removed from the lower pressure column. The first and second subsidiary waste nitrogen streams are introduced into the higher pressure heat exchanger and the lower pressure heat exchanger, respectively, for thermal balance purposes. As used herein and in the claims, the term “thermal balance purposes” means the minimization of the temperature of the streams entering and exiting the warm end of the lower pressure heat exchanger and the temperature differences of the main feed air stream and the high pressure air stream being discharged from the cold end of the higher pressure heat exchanger and the lower pressure heat exchanger, respectively. In this way, the temperature difference between the boosted-pressure air stream and the pumped liquid oxygen stream at the cold end of the higher pressure heat exchanger can be optimized. As indicated above, divergence of temperatures at the warm end of the lower pressure heat exchanger will produce warm end losses of refrigeration and such divergence in temperature at the cold end of the higher pressure heat exchanger will result in the liquid air evolving into an undesirable high vapor fraction upon its expansion that will upset the intended distillation to be carried out in the air separation unit.
The higher and lower pressure heat exchangers are configured such that the first subsidiary waste nitrogen stream undergoes a higher pressure drop in the higher pressure heat exchanger than the second subsidiary waste nitrogen stream in the lower pressure heat exchanger. This is accomplished by passing the first subsidiary waste nitrogen stream through a smaller cross-sectional flow area than would otherwise be required to produce a pressure drop in the first subsidiary waste nitrogen stream equal to that of the second subsidiary waste nitrogen stream in the lower pressure heat exchanger.
If for example, the higher pressure heat exchanger were made of plate-fin construction and used a higher cross-sectional flow area for the first subsidiary waste nitrogen stream, thicker parting sheets and side bars would otherwise be required with the result in increased fabrication costs over the heat exchanger being contemplated by the present invention. By passing the first subsidiary waste nitrogen stream through a smaller cross-sectional area its velocity will increase resulting in the higher pressure drop. However, small cross-sectional flow area will also reduce the number of layers of a plate-fin heat exchanger that are required for heat exchange of the first subsidiary waste nitrogen stream within the higher pressure heat exchanger. Since less layers are used, in case of a plate-fin heat exchanger, the height of the higher pressure heat exchanger can be reduced to reduce its fabrication costs.
An air stream can be compressed, cooled and purified. The air stream is purified in a purification unit having an adsorbent to adsorb higher boiling impurities in the air stream. The first compressed and purified air stream can be formed from a first part of the air stream after having been compressed, cooled and purified. The second compressed and purified air stream can be formed by further compressing and cooling a second part of the air stream after having been compressed, cooled and purified. The adsorbent in the purification unit is regenerated with a second of the first and second waste nitrogen streams having passed through the lower pressure heat exchanger. Thus, since the second of the waste nitrogen streams is at a higher pressure, it is capable of serving such regeneration duties. Thus, nothing is lost by allowing the first subsidiary waste nitrogen stream to undergo the higher pressure drop in the higher pressure heat exchanger.
A third part of the air stream after having been compressed, cooled and purified can be further compressed and then partially cooled within the lower pressure heat exchanger. Thereafter, it can be turboexpanded within a turboexpander to generate a refrigeration stream and therefore refrigeration for the process. The refrigeration stream can be introduced into the lower pressure column. Alternatively, a third part of the air stream after having been compressed, cooled and purified can be further compressed and cooled and then partially cooled within the higher pressure heat exchanger. Thereafter it can be turboexpanded within a turboexpander to generate a refrigeration stream and then introduced into the lower pressure column.
In any embodiment of the present invention, a crude liquid oxygen stream composed of liquid column bottoms of the higher pressure column and a nitrogen-rich liquid stream composed of liquefied nitrogen column overhead of the higher pressure column can be subcooled through indirect heat exchanger with the waste nitrogen stream and a nitrogen-rich vapor stream composed of column overhead of the lower pressure column. At least part of the crude liquid oxygen stream and at least part of the nitrogen-rich liquid stream are expanded and introduced into the lower pressure column. The nitrogen-rich vapor stream is introduced into the lower pressure heat exchanger as one of the return streams. Where refrigeration is generated in the lower pressure heat exchanger, a crude liquid oxygen stream composed of liquid column bottoms of the higher pressure column and nitrogen-rich liquid stream composed of liquefied nitrogen column overhead of the higher pressure column can be subcooled within the lower pressure heat exchanger. At least part of the liquid oxygen stream and at least part of the nitrogen-rich liquid stream are expanded and introduced in the lower pressure column. The nitrogen-rich vapor stream is introduced into the lower pressure heat exchanger as one of the return streams. In such embodiment, the nitrogen-rich liquid stream can be a first nitrogen-rich liquid stream and a second nitrogen-rich liquid stream composed of the liquefied nitrogen column overhead of the higher pressure column can be pumped and vaporized within the higher pressure heat exchanger.
In another aspect, the present invention provides an air separation apparatus. In accordance with this aspect of the invention, a main air compressor, a first after-cooler and a purification unit can be provided to compress, cool and purify an air stream. This produces a first compressed and purified air stream from a first part of the air stream after having been compressed, cooled and purified. A booster compressor, provided in flow communication with the purification unit, can further compress a second part of the air stream after having been compressed, cooled and purified and a second after-cooler can be connected to the booster compressor to cool the second part of the air stream. This forms a second compressed and purified air stream having a higher pressure than the first compressed and purified air stream. A higher pressure heat exchanger and a lower pressure heat exchanger are provided. The higher pressure heat exchanger is connected to the second after-cooler. The lower pressure heat exchanger is in flow communication with the purification unit. Each of the higher pressure heat exchanger and the lower pressure heat exchanger are of brazed aluminum construction.
The higher pressure heat exchanger and the lower pressure heat exchanger can be configured to cool the first compressed and purified air stream and the second compressed and purified air stream, respectively, through indirect heat exchange with return streams generated in an air separation unit, thereby to produce a main feed air stream and a high pressure air stream that is either in a liquid or a dense phase fluid state. The air separation unit comprises a higher pressure column connected to the lower pressure heat exchanger to receive the main feed air stream and a lower pressure column connected to the higher pressure heat exchanger by an expansion device to receive at least part of the high pressure air stream.
A pump can be provided to pressurize a liquid oxygen stream composed of a liquid oxygen column bottoms of the lower pressure column. The pump is connected to the higher pressure heat exchanger so that the liquid oxygen stream after having been pumped is introduced into the higher pressure heat exchanger and vaporized. The higher pressure heat exchanger and the lower pressure heat exchanger are also in flow communication with the lower pressure column to receive first and second subsidiary waste nitrogen streams, respectively. The first and second subsidiary nitrogen streams are formed from a waste nitrogen stream removed from the lower pressure column, for thermal balance purposes. The higher pressure heat exchanger is configured such that a smaller cross-sectional flow area for the first subsidiary waste nitrogen stream exists within the higher pressure heat exchanger than would otherwise be required to produce a pressure drop in the first subsidiary waste nitrogen stream equal to that of the second subsidiary waste nitrogen stream in the lower pressure heat exchanger. Again, as outlined above, this allows the higher pressure heat exchanger to be fabricated in a less expensive manner.
The purification unit can be provided with an adsorbent to adsorb higher boiling impurities in the air stream. The purification unit is connected to the lower pressure heat exchanger so as to receive the second of the first and second waste nitrogen streams after having passed through the lower pressure heat exchanger to regenerate the adsorbent.
A further booster compressor can also be provided in flow communication with a purification unit to further compress a third part of the air stream and a third after-cooler is connected to the further booster compressor. The lower pressure heat exchanger is connected to the further booster compressor and is configured to partially cool the third part of the air stream after having been further compressed. The turboexpander is connected between the lower pressure heat exchanger and the lower pressure column so as to turboexpand the third part of the air stream. This forms a refrigeration stream that is introduced into the lower pressure column. Alternatively, the higher pressure heat exchanger can be connected to the third after-cooler and can be configured to partially cool the third part of the air stream after having been further compressed. The turboexpander can then be connected between the higher pressure heat exchanger and the lower pressure column so as to turboexpand a third part of the air stream, thereby to form a refrigeration stream that is introduced into the lower pressure column.
In any embodiment of the present invention, a subcooler can be connected to the higher pressure column and the lower pressure column to subcool a crude liquid oxygen stream composed of liquid column bottoms of the higher pressure column and a nitrogen-rich liquid stream composed of liquefied nitrogen column overhead of the higher pressure column through indirect heat exchange with the waste nitrogen stream and a nitrogen-rich vapor stream composed of column overhead of the lower pressure column. The lower pressure column is also connected to the subcooler to receive at least part of the crude liquid oxygen stream and at least part of the nitrogen-rich liquid stream. Expansion valves located between the lower pressure column and the subcooler expand the at least part of the crude liquid oxygen stream and the at least part of the nitrogen-rich liquid stream. The lower pressure heat exchanger is connected to the subcooler to receive the nitrogen-rich vapor stream as one of the return streams.
Alternatively, the lower pressure heat exchanger can be connected to the higher pressure column and is configured to subcool the crude liquid oxygen stream composed of liquid column bottoms of the higher pressure column and the nitrogen-rich liquid stream composed of liquefied nitrogen column overhead of the higher pressure column. In such case, the lower pressure column is connected to the lower pressure heat exchanger so that part of the crude liquid oxygen stream and at least part of the nitrogen-rich liquid stream are introduced into the lower pressure column.
A nitrogen-rich liquid stream can be a first nitrogen-rich liquid stream. A pump can be connected between the higher pressure column and the higher pressure heat exchanger to pressurize a second nitrogen-rich liquid stream composed of liquefied nitrogen column overhead of the higher pressure column. The second nitrogen-rich liquid stream is vaporized within the higher pressure heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims distinctly pointing out the subject matter that Applicants regard as their invention, it is believed that the invention will be better understood when taken in connection with the accompanying drawings in which:
FIG. 1 is a schematic process flow diagram of an apparatus utilizing and carrying out a method in accordance with the present invention;
FIG. 2 is a schematic, fragmentary view of an alternative embodiment of the apparatus illustrated in FIG. 1 that is modified by incorporating a subcooling unit into a lower pressure heat exchanger in accordance with the present invention;
FIG. 3 is a schematic, fragmentary view of an alternative embodiment of the apparatus illustrated in FIG. 1 that also incorporates the alternative of FIG. 2 and that provides for production of a high pressure nitrogen product; and
FIG. 4 is a schematic, fragmentary view of an alternative embodiment of the apparatus illustrated in FIG. 1 illustrating an alternative arrangement for providing refrigeration.
The portions of FIGS. 2 , 3 and 4 that are not shown in the illustrations are the same as shown in FIG. 1 .
DETAILED DESCRIPTION
With reference to FIG. 1 , an apparatus 1 in accordance with the present invention is illustrated.
An air stream 10 is compressed in a main air compressor 12 . After removal of the heat of compression by a first after-cooler 14 , air stream 10 is purified within a purification unit 16 . Purification unit 16 , as well known to those skilled in the art can contain beds of adsorbent, for example alumina or carbon molecular sieve-type adsorbent to adsorb the higher boiling impurities contained within the air and therefore air stream 10 . For example such higher boiling impurities as well known would include water vapor and carbon dioxide that could tend to freeze and accumulate at the low rectification temperatures contemplated by apparatus 1 . In addition, hydrocarbons can also be adsorbed that could collect within oxygen-rich liquids and thereby present a safety hazard. A first compressed and purified air stream 18 is produced from a first part of air stream 10 after having been compressed, cooled and purified. A booster compressor 20 is in flow communication with purification unit 16 to compress a second part of the air stream after having been compressed, cooled and purified and a second after-cooler 22 is provided that is connected to booster compressor 20 to remove the heat of compression from the second part of air stream 10 . This forms a second compressed and purified air stream 24 having a higher pressure than the first compressed and purified air stream 18 .
It is to be noted that main air compressor 10 and booster compressor 20 are shown as single units. However, as is known in the art, two or more compressors can be installed in parallel to form either the main air compressor 10 or the booster compressor 20 . Such compressor can be of equal size, however, unequal sizes in which capacity is split can be used, for example a split of 70/30 or 60/40.
A higher pressure heat exchanger 26 is connected to second after-cooler 24 and a lower pressure heat exchanger 28 is in flow communication with purification unit 16 to receive the first compressed and purified air stream 18 . Both the higher pressure heat exchanger 26 and the lower pressure heat exchanger 28 are preferably of brazed aluminum construction and consist of layers of parting sheets separated by side bars to produce flow passages for the streams to be heated and cooled. Each of the flow passages are provided with fins as well known in the art to enhance the surface area for heat transfer within said heat exchangers. In this regard, the higher pressure heat exchanger 26 is configured to cool the second compressed and purified air stream 24 to produce a high pressure air stream 30 and the lower pressure heat exchanger 28 is configured to cool a first compressed and purified air stream to produce a main feed air stream 32 . The high pressure air stream 30 is either in a liquid or dense phase state. As can be appreciated, other types of heat exchangers could be used, for example, such as spiral wound, printed circuit and stainless steel plate-fin heat exchangers. Moreover, although each of the higher pressure heat exchanger 26 and the lower pressure heat exchanger 28 are illustrated as single units, in practice, each could consist of several heat exchangers linked together in parallel.
The lower pressure heat exchanger will have a larger cross-sectional area for flow and a large total volume than the higher pressure heat exchanger 26 . Typically the average density of the higher pressure heat exchanger 26 will be greater than the lower pressure heat exchanger 28 where density is the empty weight divided by volume. A typical density is about 1000 kg/m 3 . A typical working pressure of the higher pressure heat exchanger is about 1200 psig and greater.
An air separation unit 34 is provided that has a higher pressure column 36 operatively associated with a lower pressure column 38 in a heat transfer relationship by means of a condenser-reboiler 40 . Optionally, as illustrated, air separation unit 34 also includes an argon column 42 that is connected to low pressure column 38 for producing an argon product. It is understood however that argon column 42 is optional and the present invention has applicability to an air separation unit consisting solely of the higher pressure column 36 and the lower pressure column 38 . It is understood that each of the higher pressure column 36 , lower pressure column 38 and argon column 42 contain liquid-vapor mass transfer elements such as sieve trays or packing, either random or structured. Such elements as well known in the art enhance liquid-vapor contact of liquid and vapor phases of the mixture to be separated in each of such columns for rectification purposes.
High pressure air stream 30 is expanded to a pressure suitable for its introduction into higher pressure column 36 by way of a liquid turboexpander 44 . Energy from liquid turboexpander 44 can be recovered. Alternatively, an expansion valve can be used. After having been expanded, high pressure air stream 30 is divided into a first subsidiary expanded stream 46 and a second subsidiary expanded stream 48 . It is understood that typically first and second subsidiary expanded air stream 46 and 48 are two phase streams. Second subsidiary expanded stream 48 is expanded by an expansion valve 50 to pressure suitable for its introduction into lower pressure column 38 . Thus, both first and second subsidiary expanded streams 46 and 48 are introduced into intermediate locations of higher and lower pressure columns 36 and 38 , respectively at points thereof that would match the composition of the mixture being separated in the columns. It is understood, however, that embodiments of the present invention are possible in which the higher pressure air stream 30 is introduced into either the higher pressure column 36 or the lower pressure column 38 .
The rectification of the air within higher pressure column 36 produces a crude liquid oxygen column bottoms and a nitrogen-rich vapor column overhead. A nitrogen-rich vapor column overhead stream 52 is condensed in condenser-reboiler 40 against vaporizing an oxygen-rich column bottoms that is produced by the rectification occurring in the lower pressure column. In this regard, such rectification also produces, within lower pressure column 38 , a nitrogen-rich vapor column overhead. The resultant condensation produces a nitrogen-rich liquid stream 54 . First part 56 of nitrogen-rich liquid stream 54 is returned to higher pressure column 36 as reflux. A second part 58 is subcooled within a subcooling unit 60 , expanded within an expansion valve 62 to a pressure suitable for its introduction to lower pressure column 38 and then introduced into lower pressure column 38 as reflux. A crude liquid oxygen stream 64 is also subcooled within subcooling unit 60 , expanded in an expansion valve 64 and a first part 66 thereof is introduced into lower pressure column 38 for further refinement. Additionally, a first part 63 of the nitrogen-rich liquid stream is introduced into lower pressure column 38 . As illustrated, a second part 68 of the nitrogen-rich liquid stream after having been subcooled can be taken as a product stream. Also, a second part 70 of crude liquid oxygen stream 64 is expanded in an expansion valve 71 and then partially vaporized within an argon condenser 72 contained within a shell 73 . Liquid and vapor fractions of second part 70 of crude liquid oxygen stream 64 designated by reference numerals 74 and 76 , respectively are reintroduced into the lower pressure column 38 .
At a suitable point within lower pressure column 38 , an argon-rich stream 78 is withdrawn and rectified within an argon column 42 to produce an argon-rich vapor stream 80 that is condensed within argon condenser 73 to produce an argon-rich liquid stream 82 . A first part 84 of argon-rich stream 82 can be taken as an argon product stream and a second part 86 thereof can be returned to argon column 42 as reflux.
A nitrogen vapor product stream 88 can be removed from the top of lower pressure column 38 and a waste nitrogen stream 90 can be removed below the top of low pressure column 38 in order to maintain the purity of nitrogen product stream 88 . Nitrogen product stream 88 and crude nitrogen stream 90 then partially warmed within subcooling units 60 in order to subcool crude liquid oxygen stream 64 and nitrogen-rich liquid stream 58 . Additionally, a liquid oxygen stream 92 composed of the oxygen-rich liquid column bottoms of lower pressure column 38 can be removed therefrom. The first part 94 of liquid oxygen stream 92 can be pressurized by a pump 96 to produce a pumped liquid oxygen stream 98 and a second part 100 of liquid oxygen stream 92 can optionally be taken as a product. Pumped liquid oxygen stream 98 , nitrogen product stream 88 and in a manner to be discussed, crude waste nitrogen stream 90 constitutes return streams of the air separation unit 34 that are used to cool the incoming air within higher pressure heat exchanger 26 and lower pressure heat exchanger 28 . Pumped liquid oxygen stream 98 is vaporized within higher pressure heat exchanger 26 to produce a high pressure oxygen product stream 102 . Nitrogen product stream 88 after having been partially warmed within subcooling unit 60 is introduced into lower pressure heat exchanger 28 and then optionally compressed with a compressor 104 to produce a nitrogen vapor product stream 106 .
After partially warming with subcooling unit 60 , waste nitrogen stream 90 is divided into a first subsidiary waste nitrogen stream 108 and a second subsidiary waste nitrogen stream 110 . First subsidiary waste nitrogen stream 108 and second subsidiary waste nitrogen stream 110 are introduced into higher and lower pressure heat exchangers 26 and 28 , respectively, for thermal balancing purposes such as have been described above. Advantageously, second subsidiary waste nitrogen stream 110 , after having traversed lower pressure heat exchanger 28 , can be divided into first and second portions 112 and 114 . Portion 112 can be utilized to regenerate the adsorbent within purification unit 16 in a manner known in the art and second subsidiary waste nitrogen stream 108 is fully warmed and discharged as a waste nitrogen stream 116 . As described above, thermal balancing is required in order to minimize the temperature difference between the return streams and the air streams within lower pressure heat exchanger 28 at the warm end thereof, namely, second subsidiary waste nitrogen stream 110 , product nitrogen stream 88 and incoming first compressed and purified air stream 18 to eliminate warm end refrigeration losses at lower pressure heat exchanger 28 . Low pressure air stream 32 and high pressure air stream 30 will be similar temperatures such that the temperature difference between pumped liquid oxygen stream 98 and high pressure air stream 30 must is optimized. If the temperature of high pressure air stream 30 is too high, upon expansion thereof within liquid turboexpander 40 or an expansion valve, too much vapor will evolve and will not produce the desired distillation.
As also mentioned above, higher pressure heat exchanger 26 and lower pressure heat exchanger 28 are preferably of brazed aluminum design. Higher pressure heat exchanger 26 , given its high pressure environment, will require thicker parting sheets and side bars and high fabrication costs. In order to decrease the fabrication costs, yet perform the thermal balancing function, cross-sectional flow area for first subsidiary waste nitrogen stream 108 is sized such that first subsidiary waste nitrogen stream 108 undergoes a higher pressure drop and therefore, the warm waste nitrogen stream 116 is at a lower pressure than first and second parts 112 and 114 of fully warmed second subsidiary waste nitrogen stream 110 . The cross-sectional flow area is selected such that the pressure drop within the higher pressure heat exchanger 26 of first subsidiary waste nitrogen stream 108 is greater than that would otherwise have been required to produce the pressure drop of second subsidiary waste nitrogen stream 110 within lower pressure heat exchanger 28 . Given the fact that first part 112 of fully warmed second subsidiary waste nitrogen stream 110 has not undergone a great pressure drop, it can be utilized to regenerate the absorbent within prepurification unit 16 .
As described above and as well known in the art, plate-fin heat exchangers have a layered construction in which each of the streams, for example the incoming air stream, the nitrogen-rich stream and etc. pass through separate layers that are arranged in a pattern to efficiently conduct indirect heat exchange between the streams. The layered construction is produced in such heat exchangers by a series of parallel parting plates and peripheral side bars to seal the layers along their edges. Manifolds are provided to feed the streams into the layers. An arrangement of fins is provided in each of the layers that increase the area available for the heat exchange. In the preferred embodiment, the cross-sectional flow area of the higher pressure heat exchanger 26 is reduced by manipulating the number of layers therewithin. As a result, higher pressure heat exchanger 26 is of lower height than it otherwise would have been had the pressure drop within first subsidiary waste nitrogen stream 108 and second subsidiary waste nitrogen stream 110 been equal. Nonetheless, the higher velocity of stream 108 through high pressure heat exchanger 26 enables the necessary heat transfer to be accomplished due to dramatically improved heat transfer coefficients. Similarly, for a spiral wound heat exchanger the increased velocity will result in the necessary heat transfer being accomplished with a smaller number of tubes for the first subsidiary waste nitrogen stream. The whole unit will therefore be smaller and require less material.
A printed circuit-type heat exchanger is similar to a plate-fin heat exchanger in that it is constructed from a number of layers. A higher velocity of the first subsidiary nitrogen stream will result in a higher pressure drop for the same heat transfer, but at the expense of fewer layers and therefore a cheaper heat exchanger.
As well known in the art, any cryogenic rectification plant must be refrigerated in order to overcome warm end heat exchange losses. In air separation plant 1 , a third part 118 of the compressed and purified air stream 10 after having been compressed, cooled and purified is then further compressed within a booster compressor 120 and then cooled within a third after-cooler 122 . After partially cooling within lower pressure heat exchanger 28 , the resultant partially cooled stream 124 can be introduced into a turboexpander 126 to produce a refrigeration stream 128 as an exhaust. Refrigeration stream 128 is introduced into lower pressure column 38 .
With reference to FIG. 2 a lower pressure heat exchanger 28 ′ is illustrated that is an alternative embodiment to lower pressure heat exchanger 28 shown in FIG. 1 . In lower pressure heat exchanger 28 ′, the subcooling unit 60 has been eliminated and incorporated into the lower pressure heat exchanger 28 ′. The resultant method and apparatus is much the same as that described with respect to air separation plant 1 . However, the main air stream 32 is withdrawn at an intermediate location of lower pressure heat exchanger 28 ′ given the lower cold end temperatures that result from the elimination of the subcooling unit 60 .
With reference to FIG. 3 , an alternative embodiment of the air separation plant shown in FIG. 1 and as modified in FIG. 2 is to produce a high pressure nitrogen product stream by pumping a first part 68 ′ of the nitrogen-rich liquid stream within a pump 130 and then vaporizing the pumped nitrogen stream to produce a high pressure nitrogen vapor stream 132 within higher pressure heat exchanger 26 ′ that is provided with passages for such purpose. As can be appreciated, the air separation column of FIG. 3 would in all other respects be similar to the air separation plant shown in FIG. 2 . Moreover, a product nitrogen stream 68 could be taken as illustrated in FIGS. 1 and 2 .
With reference to FIG. 4 , a third part 136 of air stream 10 after having been compressed, cooled and purified can be compressed in a booster compressor 138 and cooled within a third after-cooler 140 to remove the heat of compression and is then partly cooled within a higher pressure heat exchanger 26 ′ having passages provided for such purpose. The resulting partially cooled stream 142 can be expanded within a turboexpander 144 to produce a refrigerant stream 146 from the exhaust thereof. Refrigerant stream 146 can be introduced into the lower pressure column 38 . In all other respects, the embodiment shown in FIG. 4 can be the same as that illustrated in FIG. 1 . The following table summarizes a calculated example for a process in accordance with the present invention that is conducted with the apparatus shown in FIG. 3 .
Stream
Temper-
Pressure,
Percent
No.
Flow
ature, K
psia
Composition
vapor
*10
5036
285.9
87.6
Air
100
18
2875
285.9
87.6
Air
100
24
1623
308.2
1600
Air
100
32
2875
102.1
84.2
Air
100
30
1623
99.1
1597
Air
0
46
454
96.7
83.7
Air
0
**48
1169
81.5
19.1
Air
15.8
124
538
183.8
161.0
Air
100
128
538
108.9
19.5
Air
100
68
21.7
80.8
80.9
99.9995% N 2 + Ar
0
84
34.2
88.5
16.8
99.9997% Ar
0
100
29.4
93.7
20.9
99.6% O 2
0
102
1000
304.1
1266
99.6% O 2
100
110
2293
79.8
18.5
98.6% N 2
100
***110
2293
286.9
16.5
98.6% N 2
100
108
416
79.8
18.5
98.6% N 2
100
116
416
304.1
15.5
98.6% N 2
100
****88
1000
286.9
16.2
99.9995% N 2 + Ar
100
132
241
304.1
175
99.9995% N 2 + Ar
100
*10: Air stream 10 after having been compressed in main air compressor 12 and purified within purification unit 16.
**48: Second subsidiary expanded stream 48 after passage through valve 50.
***110: Second subsidiary waste nitrogen stream 110 after passage through lower pressure heat exchanger 28
****88: Nitrogen vapor product stream after passage through lower pressure heat exchanger 28.
While the present invention has been described with reference to preferred embodiments, as will occur to those skilled in the art, numerous changes and additions and omissions can be made without departing from the spirit and the scope of the present invention that set forth in the presently pending claims.
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A compressed air stream is cooled to a temperature suitable for its rectification within a lower pressure heat exchanger and a boosted pressure air stream is liquefied or converted to a dense phase fluid within a higher pressure heat exchanger in order to vaporize pumped liquid products. Thermal balancing within the plant is effectuated with the use of waste nitrogen streams that are introduced into the higher and lower pressure heat exchangers. The heat exchangers are configured such that the flow area for the subsidiary waste nitrogen stream within the higher pressure heat exchanger is less than that would otherwise be required so that the subsidiary waste nitrogen streams were subjected to equal pressure drops in the higher and lower pressure heat exchangers. This allows the higher pressure heat exchanger be fabricated with a reduced height and therefore a decrease in fabrication costs.
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FIELD OF THE INVENTION
The present invention relates to ultrasonic transducers, and more specifically to an apparatus and method for electronically driving an ultrasonic transducer.
BACKGROUND OF THE INVENTION
Ultrasonic testing systems have been designed and built to meet the needs of a variety of applications. One application is non-destructive evaluation, where ultrasonic acoustic energy is applied to an object-being-probed (a "specimen"), and the echo of reflected or scattered acoustic energy, caused by cracks or density differentials, is received and analyzed to reveal the internal and/or surface structure of the specimen.
A typical ultrasonic transducer is a quartz crystal or other piezo-electric device which can convert a high-frequency (i.e. >20,000 Hz) alternating-current electrical signal into a corresponding acoustical signal and vice versa. The transducer is often modeled as a tuned LC (inductance-capacitance) circuit, with one resonant frequency. Real-world transducers can have locally-resonant characteristics at a multiplicity of frequencies. At a resonant frequency, a greater amount of acoustical energy is generated from a given amount of electrical energy (and vice versa) than at other non-resonant frequencies. Any input electrical signal which is not converted into acoustical energy is typically converted into waste heat in the transducer.
One technique for broadening the bandwidth of the resonant frequency is to provide mechanical damping for the transducer.
Acoustic energy is typically coupled from the transducer to the specimen by a coupling medium, often a liquid such as water or oil. The coupling medium is designed to minimize acoustic discontinuities in the path of the acoustic wave which would otherwise lessen the energy transmitted between the transducer and the specimen. Once inside the specimen, the acoustic wave reflects and scatters from cracks and other acoustic transmission discontinuities in the specimen. The acoustic signal thus echoed by the internal features of the specimen is then received by a transducer. If the same transducer is used for both transmission and reception of the acoustic signal, then the system is called a "pitch-catch mode" system; if separate transducers are used for transmission and reception, then the system is called a "pulse-echo mode" system. The received signal is converted back into an electrical signal and then amplified, analyzed, and displayed.
The wavelength of an acoustic wave at a given frequency is a function of the velocity of the wave in the transmission medium.
One type of ultrasonic testing system is the "continuous wave" system. A single-frequency, sine wave (or approximately sine wave) electrical signal at or near the resonant frequency of the transducer is coupled to the transducer, which converts the electrical signal into a corresponding acoustic sine wave. This acoustic wave is coupled to the specimen, and the echo received (typically by a separate transducer) and amplified (typically by a tuned amplifier). The amplitude and phase of the echoed signal is then analyzed. This technique is often used to measure velocities of physical components internal to the specimen (e.g., blood velocity in a vein), or attenuation of the signal due to inhomogeneities. This type of system is simple, relatively inexpensive, and can do quite accurate measurement of velocities using resonance techniques; however, since range information is not available, it is difficult to pinpoint an internal flaw region.
Another type of ultrasonic testing system is the "continuous-wave, swept-frequency" system. A ramp generator drives a variable-frequency oscillator to generate the swept-frequency transmission signal which drives the transmitting transducer. The same ramp generator tunes a variable-frequency tuned amplifier which amplifies the received signal (which is typically received by a separate transducer), which is then analyzed and displayed. This type of system has greater frequency diversity, and can do automated measurements over a range of frequencies; however, since range information is still not available, it is difficult to pinpoint an internal flaw region, and expensive components and broadband transducers are required.
Another type of ultrasonic testing system is the "pulsed single-frequency" system. A single-frequency oscillator is amplitude-modulated with a pulse; the resulting "tone burst" drives the transducer with a few cycles (e.g., ten cycles) of sine wave. Because the tone burst has a beginning and end, it is possible to measure time delay, as well as amplitude and phase information; this allows measurement of depth in the specimen.
Another type of ultrasonic testing system is the "pulsed, swept-frequency" system. A ramp generator drives a variable-frequency oscillator to generate a slowly swept frequency transmission signal, which is amplitude-modulated with a pulse; the resulting "tone burst" drives the transducer with a few cycles (e.g., ten cycles) of sine wave whose frequency continuously varies. The received signal is then amplified, analyzed, and displayed. This type of system has greater frequency diversity, and because the tone burst has a beginning and end, it is also possible to measure time delay as well as amplitude and phase information; this allows measurement of depth in the specimen; however, acquisition of spectra and signals takes a longer time than with other systems, the system is complex, and expensive components and broadband transducers are required.
Yet another type of ultrasonic testing system is the "pulsed, broadband analog" system. Some systems use a single, high-voltage (approximately 100 to 300 volts) pulse with a wide spectrum of frequencies to drive the transducer. Other researchers have suggested that a step-function driver be used rather than the pulse-function driver. The reflected signal is received and amplified. This type of system has good frequency diversity, and because the pulse has a beginning and end, it is also possible to measure time delay as well as amplitude information; this allows measurement of depth in the specimen; however, phase information is difficult to extract, the system is complex, and expensive hazard-reduction precautions may be required for the high-voltage pulse. Since the transducer acts like a tuned L-C circuit, much of the energy of frequency components outside the resonant frequencies of the transducer goes into waste heat.
None of the above systems provide particularly efficient conversion of electrical energy into acoustical energy (and vice versa) combined with the ability to measure time delay. Some methods involve driving the transducer with voltage signals which can be dangerous in a medical environment. Other methods use a continuous-wave signal which is not very useful in echo-location of interior structures of the item being investigated. What is needed is a method and apparatus which maximize signal conversion, minimize voltages to the transducer, and facilitate measurement of phase shift, time delay, and signal attenuation in the specimen.
SUMMARY OF THE INVENTION
The present invention provides a method for electronically driving an ultrasonic acoustic transducer. The method is operable in two modes; operating in a first mode, a lock-in frequency is determined by exciting the transducer with a series of tone bursts, where each tone burst comprises an electronic pulse modulated by a tone of a single frequency selected from a range of frequencies, and measuring the response of the transducer to each tone-burst. The lock-in frequency is then chosen by examining these responses and choosing the frequency which gives the best response. Operating in a second mode, the transducer is driven with an electronic tone burst generated by modulating an electronic pulse with a tone of the determined lock-in frequency.
In an alternative embodiment, the excitation of the transducer in the first mode is provided by a signal whose frequency is swept over a range. The response of the transducer is sampled at various times during the sweep of frequencies.
The response can be measured in any suitable manner, such as measuring the voltage across the transducer, the current into the transducer, or the acoustic output of the transducer.
According to another aspect of the present invention, a transducer driver apparatus is described which operates at the lock-in frequency of an ultrasonic acoustic transducer in order to more efficiently transfer energy from an electrical to an acoustic signal. The transducer driver apparatus is operable in two modes. Operating in a first mode, the apparatus determines the lock-in frequency of the transducer by exciting the transducer with a series of tone bursts, where each tone burst comprises an electronic pulse modulated by a tone of one frequency selected from a range of frequencies, and measuring the response of the transducer to each tone burst; the lock-in frequency is then chosen by examining the responses and choosing the frequency which gives the best response. Operating in a second mode, the apparatus uses the lock-in frequency determined in the first mode to modulate a tone-burst pulse which drives the transducer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a block diagram representative of an embodiment of an ultrasonic transducer system according to the invention using a single transducer.
FIG. 1b is a block diagram representative of an embodiment of an ultrasonic transducer system according to the invention using separate transmission and reception transducers.
FIG. 2 is a block diagram of a digital phase-locked-loop oscillator which could be used in the ultrasonic transducer system of FIG. 1a.
FIG. 3 is a schematic diagram of an embodiment of a gating circuit/switching circuit used in the ultrasonic transducer system of FIG. 1a.
FIG. 4 is a schematic diagram of an embodiment of a demodulator mixer/low-pass filter used in the ultrasonic transducer system of FIG. 1a.
FIG. 5 is a flow-chart depicting the overall operation of the ultrasonic transducer system of FIG. 1a.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
It is desirable for an ultrasonic transducer driver system to drive the transducer with a signal which the transducer can most efficiently convert into acoustic energy. It is also desirable that the signal chosen will allow the system to measure time delay and phase shifts.
FIG. 1a and FIG. 1b illustrate embodiments of an ultrasonic transducer system according to the invention. FIG. 1a is a block diagram showing an embodiment of the invention which uses a single transducer for both transmission and reception of the ultrasonic acoustic signal. Controller 181 is a general-purpose microcomputer having a memory and operating under control of a stand-alone computer program which is executed to control operation of the invention. In one particular embodiment, controller 181 comprises an IBM PC computer from IBM Corp. of Armonk, N.Y., a GPIB controller card from National Instruments, and an interface card using an Intel i8255 chip from Intel Corp. and plugged into the IBM PC bus.
Oscillator 183 is a variable-frequency signal source capable of (a.) generating a tone signal 184 at a frequency within a range of frequencies, and (b.) responsive to frequency-control signal 182. Controller 181 provides frequency control signal 182 to control the frequency of oscillator 183. In one embodiment, oscillator 183 is a digital phase-locked loop oscillator circuit, and frequency control signal 182 is a digital signal representative of the frequency to be generated.
Gating circuit 186 modulates the amplitude of tone signal 184 in order to generate tone-burst signal 187. Controller 181 provides pulse-control signal 185 to control the timing and inter-pulse period, as well as the shape and duration of tone-burst signal 187. In one embodiment, during a first "pulse" period gating circuit 186 passes approximately 9 cycles of signal 184 to tone-burst signal 187, where each passed cycle is of approximately equal amplitude. The pulse period is followed by a second, much longer, "inter-pulse" period during which essentially no signal is passed to tone-burst signal 187. In one embodiment, during the inter-pulse period, gating circuit 186 couples tone signal 184 to dummy load 179 in order to maintain an even load on oscillator 183 across both the pulse and inter-pulse periods; this even load helps stabilize the output characteristics of oscillator 183.
In one embodiment, during transmission mode, switching circuit 189 acts under control of switching-control signal 188 from controller 181 to couple tone-burst signal 187 to transducer path 190, which is then coupled to ultrasonic transducer 191. At the time of the end of the tone burst, switching circuit 189 changes state to reception mode, disconnecting tone-burst signal 187 from transducer path 190 and coupling the received transducer signal (generated by ultrasonic transducer 191 in response to acoustic stimulation) from transducer path 190 to received signal 192. During transmission mode, ultrasonic transducer 191 converts transmitted tone-burst signal from transducer path 190 into acoustic energy in order that the acoustic energy will enter the object being probed, specimen 170. As the acoustic energy encounters discontinuities or density gradients in specimen 170, some of the energy is scattered or reflected as an echo. During reception mode, this acoustic echo is then received by ultrasonic transducer 191 and converted back into a received transducer signal on transducer path 190; switching circuit 189 now couples the received transducer signal from transducer path 190 to received signal 192 which is amplified by amplifier 193 to generate amplified received signal 194.
Demodulator 198, comprising mixer 195, low-pass filter 196, and amplifier 197, then demodulates amplified received signal 194 to generate output signal 199. Mixer 195 mixes (i.e., multiplies) amplified received signal 194 with tone signal 184; this mixing step emphasizes certain information contained in amplified received signal 194. Such a "product detector" mixer-type detector allows pursuit of additional signal processing options, due to the synchronous detection and the coherent nature of the system. An alternative embodiment uses a standard diode-capacitor detector in place of mixer 195 to perform an asynchronous detection. Additional biasing circuitry may be required if a diode-capacitor detector is employed in mixer 195. If a product detector is used, the result is then passed through low-pass filter 196 which removes the frequency remnants of tone signal 184 as well as any higher-frequency components introduced by mixer 195. The resulting "base-band" signal is then amplified by amplifier 197 to produce base-band output signal 199.
It is an object of the present invention to determine the "lock-in" frequency of ultrasonic transducer 191. This lock-in frequency is the frequency of tone signal 184 at which the maximum energy from the tone-burst signal transmitted on transducer path 190 is converted into acoustic energy by transducer 191. In a first mode, which is used to determine the lock-in frequency, transducer path 190 is also coupled through pre-amp 62 to analog-to-digital converter 162 which measures the voltage of the tone-burst signal transmitted on transducer path 190 and generates digital transducer signal 163 which is representative of the magnitude of the voltage of the tone-burst signal transmitted on transducer path 190; the lock-in frequency is chosen as the frequency of tone signal 184 which creates the minimum voltage across transducer 191 during the tone-burst signal transmitted on transducer path 190. In another embodiment, analog-to-digital converter 162 measures the current of the tone-burst signal transmitted on transducer path 190 and generates digital transducer signal 163 which is representative of the magnitude of the current of the tone-burst signal transmitted on transducer path 190 during the tone burst; the lock-in frequency is the frequency which creates the maximum current into transducer 191. In yet another embodiment, analog-to-digital converter 162 measures the voltage of the received transducer signal on transducer path 190 (during reception mode) and generates digital transducer signal 163 which is representative of the magnitude of the acoustic energy received by ultrasonic transducer 191 as an echo from the acoustic wave created by the tone-burst signal; the lock-in frequency is the frequency of tone signal 184 which creates the maximum echoed acoustic wave.
In an alternative embodiment, the excitation of the transducer in the first mode is provided by a signal whose frequency is swept over a range. Oscillator 183 is swept over a range of frequencies. Gating circuit 186 is turned "on" to continuously couple the swept frequency through switching circuit 189 to ultrasonic transducer 191. The response of the transducer is sampled by A/D converter 162 at various times during the sweep and reported to controller 181 which controls the frequency of oscillator 183.
The selected lock-in frequency of transducer 191 can be, but need not be, one of the frequencies actually used to excite transducer 191 during the first mode; in one embodiment, if enough information is obtained from the response measurements, the lock-in frequency can be selected based on the direction and slope of the frequency-response curve as measured on either side of the predicted lock-in frequency.
Many other embodiments which could be used to measure the conversion of tone-burst-signal energy into acoustic energy will be apparent to those of skill in the art upon reviewing the above description.
In an alternative embodiment shown in FIG. 1b, tone-burst signal 187 is directly coupled to ultrasonic transducer 191; a second ultrasonic transducer 191' is used to receive the scattered or reflected acoustic echo and convert it into transducer signal 192. In the embodiment shown, analog-to-digital converter 162 is coupled to measure the voltage of transmitted tone-burst signal 187. Other aspects of FIG. 1b are analogous to the description for FIG. 1a. In another embodiment (not shown), analog-to-digital converter 162 is coupled to measure the voltage of received signal 192.
FIG. 2 is a block diagram of a digitally controlled phase-locked-loop oscillator which could be used for oscillator 183 in the ultrasonic transducer system of FIG. 1a. Reference-frequency generator 210 provides a reference frequency 211. Phase detector 220 generates a dynamic phase-error signal 221 which is proportional to the phase difference between reference signal 211 and frequency-divided tone signal 271 (described further below). Low-pass filter 230 generates static phase-error signal 231 by filtering dynamic phase-error signal 221 to remove unwanted high-frequency components. Voltage-controlled oscillator 240 generates tone signal 184 whose frequency is a function comprised, inter alia, of static phase-error signal 231. Prescaler 250 divides the frequency of tone signal 184 by one of two divisors to generate intermediate-frequency signal 251 (depending on prescaler-control signal 261, prescaler 250 divides the frequency of tone signal 184 by either divisor P or by divisor P+1).
When reset, programmable divide-by-"A" counter 260, clocked by intermediate frequency signal 251, starts counting down from the digital value COUNT "A" which is set by frequency-control signal 182; at the same time, programmable divide-by-"B" counter 270, also clocked by intermediate-frequency signal 251, starts counting down from the digital value COUNT "B" which is separately set by frequency-control signal 182. Frequency-control signal 182 sets the digital value of COUNT "A" to be smaller than COUNT "B"; neither value is set to zero.
While divide-by-"A" counter 260 is counting, prescaler-control signal 261 specifies that prescaler 250 divides by P+1 (so intermediate-frequency signal 251 has one cycle for every P+1 cycles of tone signal 184). When divide-by-"A" counter 260 reaches zero, it stops counting and prescaler-control signal 261 changes to specify that prescaler 250 divides by P (so intermediate-frequency signal 251 has one cycle for every P cycles of tone signal 184). Prescaler-control signal 261 will continue to specify that prescaler 250 divides by P until divide-by-"B" counter 270 reaches zero. (At this time divide-by-"A" counter 260 reaches zero, (a) divide-by-"B" counter 270 will have decremented "A" times, (b) divide-by-"B" counter 270 will have a value of "B"-"A", and (c) tone signal 184 will have had "A"*(P+1) cycles.) When divide-by-"B" counter 270 reaches zero, it will generate one cycle on frequency-divided tone signal 271. (At the time divide-by-"B" counter 270 reaches zero, divide-by-"B" counter 270 will have decremented an additional "B"-"A" times, during which tone signal 184 will have had an additional ("B"-"A")*(P) cycles.) Frequency-divided tone signal 271 will then reset divide-by-"A" counter 260 and divide-by-"B" counter 270.
The result of this overall loop is that frequency-divided tone signal 271 will have one cycle for every (A*(P+1))+((B-A)*P) cycles of tone signal 184. When the phase-locked loop is operating, it will keep the phase of frequency-divided tone signal 271 locked to the phase of reference-frequency signal 211, and thus tone signal 184 will have a frequency of (A*(P+1))+((B-A)*P) times--i.e., A+(B*P) times--the frequency of reference-frequency signal 211. The frequencies at which oscillator 183 can be set (the "channels" of the phase-locked loop) are thus integer multiples of the frequency of reference-frequency signal 211; the minimum and maximum frequencies of the phase-locked loop are typically determined by the capabilities of the voltage-controlled oscillator 240; the minimum frequency will be at least P+1 times the frequency of reference-frequency signal 211.
In one embodiment, a tone signal 184 voltage of 2 volts peak-to-peak was specified. A frequency range of 500 KHz to 200 MHz was specified. A channel spacing of 10 KHz was specified for frequencies between 500 KHz and 10 MHz, and a channel spacing of 100 KHz was specified for frequencies between 10 MHz and 200 MHz. A lock-in time of 1 millisecond was specified for the phase-locked loop. The prescaler 250, divide-by-"A" counter 260, and divide-by-"B" counter 270 are powered from controller 181, and are optically isolated from the analog section comprising phase detector 220, low-pass filter 230 and voltage-controlled oscillator 240.
In one embodiment, an HP6060B signal generator made by Hewlett Packard Corp. is used for oscillator 183. In an alternative embodiment, any suitable variable-frequency-controlled oscillator can be used for oscillator 183 (such as are illustrated in the books: W. F. Egan, Frequency Synthesis by Phase Lock, New York, Wiley, 1981, and W. C. Lindsey & C. M. Chie, Phase-Locked Loops, New York, IEEE Press, 1986).
In one embodiment, an HP57410 digitizing oscilloscope from Hewlett Packard Corp. is used for analog-to-digital converter 162.
FIG. 3 is a schematic diagram of an embodiment of a gating circuit/switching circuit used in the ultrasonic transducer system of FIG. 1a. "BNC"-type jack J2 couples tone signal 184 (the input radio-frequency source) to gating circuit 186. Gating circuit 186 is implemented using integrated circuits U3, a "Y3WA-50DR"-type switch chip capable of switching in less than 10 nanoseconds, and U4, an "AD9630"-type amplifier. Dummy load resistor 179 is a 50-ohm resistor, specified to match the load characteristics of integrated circuit U4. Switching circuit 189 is implemented using integrated circuit U5, also a "Y3WA-50DR"-type switch chip.
FIG. 4 is a schematic diagram of an embodiment of a demodulator (a mixer and low-pass filter) used in the ultrasonic transducer system of FIG. 1a. Amplifier 193 amplifies signal 192. Mixer 195 is implemented using an SBL-3 product-type mixer from Mini-Circuit Corp., PO Box 350166, Brooklyn, N.Y. 11235-0003, that is commercially available. Low-pass filter 196 is a fourth-order Butterworth filter. Amplifier 197 amplifies the output signal of low-pass filter 196. BNC jack J1 couples output signal 199.
FIG. 5 is a flow-chart depicting the overall operation of a program which controls the ultrasonic transducer system of FIG. 1a. In one embodiment, the program is written in the C programming language, and executed from a computer program memory in controller 181. Block 510 represents operation in a first mode, wherein a lock-in frequency of transducer 191 is determined. Block 520 represents operation in a second mode, wherein the lock-in frequency of transducer 191 determined at block 510 is used to stimulate transducer 191. Block 510 comprises steps 511 through 518. Block 511 represents reading the input frequency range and pulse width to be used in the process of determining the lock-in frequency. In this particular embodiment, the input frequency range and pulse width are empirically derived for a particular type of transducer. The pulse width is chosen to be short enough that, using the subject medium of interest, the trailing edge of the pulse train has left the transducer before the echo from the leading edge of the pulse, having bounced off the closest feature of interest, returns to the transducer. The pulse is also chosen to be long enough to ensure that the spectral width of the excitation signal is sufficiently narrow to capture only one of the resonance modes of the transducer.
A typical ultrasonic transducer is a fairly complex device which exhibits multiple locally-resonant modes. If the transducer is excited, in the first mode, over a broad range of frequencies, it is likely that the method could "home in" on a mode that is not located close to the nominal frequency. Therefore, the method and apparatus are typically restricted to scan several KHz on either side of the stated nominal frequency of a commercially-available transducer. A range of 10 to 15% of the nominal frequency on either side was found to be reasonable in one embodiment.
Block 512 represents setting the tone signal 184 to the minimum frequency in the input range of frequencies to be used. At block 513, a tone burst at the set tone-signal frequency (having a duration equal to the set pulse width) is sent to transducer 191. At block 514, the response of transducer 191 to this electronic tone burst is measured. At block 515, the frequency set for tone signal 184 and the response measured from transducer 191 are stored in the computer program memory in controller 181. At block 516 the frequency of tone signal 184 is set to the frequency of the next channel (the frequency is incremented by the channel spacing of oscillator 183). If at 517, the frequency does not exceed the maximum frequency of the set frequency range, the control is passed back to step 513 to initiate a test at the new channel frequency; otherwise, control passes to block 518. At block 518, the responses stored in computer memory are examined to determine the optimal frequency for transducer 191; in an embodiment measuring the transducer voltage during a transmitted tone burst, the optimal frequency corresponds to the minimum voltage measured, and the lock-in frequency selected is that frequency corresponding to the minimum voltage measurement. Control then passes back through block 510 to block 520. Block 520 represents operation in a second mode (the normal operating mode), wherein the lock-in frequency of transducer 191 determined at block 510 is used to stimulate transducer 191. Transducer 191 is then used to receive the echoes from the interaction of the tone burst with specimen 170 and generate a received signal 192. This signal is then demodulated as described above in the discussion of FIG. 4, and is then displayed by conventional means.
It is to understood that the above description is intended to be illustrative, and not restrictive. The method for electronically driving an ultrasonic transducer described in the above embodiments of the invention use impedance measurement to determine a lock-in frequency for the transducer. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. For instance, rather than impedance measurement, an embodiment could utilize acoustic signal measurement. Also, a method suited for incrementally stepping through the frequency range of interest is described above, but a person skilled in the art could use a similar method in which frequencies are tested in a successive approximation sequence to first determine successively smaller ranges of frequencies to test subsequently. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
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A method and apparatus for electronically driving an ultrasonic acoustic transducer. The transducer is operable in two modes; in a first mode, the lock-in frequency of the transducer is determined; in a second mode, the lock-in frequency determined in the first mode is used to modulate a tone-burst pulse to drive the transducer in an efficient manner. Operating in the first mode, the lock-in frequency is determined by exciting the transducer with a series of tone bursts, where each tone burst comprises an electronic pulse modulated by a tone of one frequency selected from a range of frequencies, and measuring the response of the transducer to each tone burst. In an alternative embodiment, the excitation of the transducer in the first mode is provided by a signal whose frequency is swept over a range. The response of the transducer is sampled at various times during the sweep. The lock-in frequency is chosen by examining the responses and choosing the frequency which gives the best response. Operating in the second mode, the transducer is driven with an electronic tone burst generated by modulating said an electronic pulse with a tone of the determined lock-in frequency.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2013-0159029 filed on Dec. 19, 2013, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a method of manufacturing a curved solar cell module having the same curvature as a vehicle roof panel.
BACKGROUND
[0003] Recently, as an environment-friendly energy field has been highlighted, photoelectric conversion elements, such as a solar cell, have been widely used.
[0004] Among them, a silicon solar cell has been commercially used and already applied to a sun roof part of a vehicle, but the silicon solar cell may be limited in use due to an opaque property and high cost.
[0005] Accordingly, a dye sensitized solar cell used as a semi-transparent and transparent solar cell has been recently developed for a commercial use, such that research for application of the solar cell to various application fields such as vehicle and building integrated photovoltaic (BIPV) has been actively conducted.
[0006] In general, the dye sensitized solar cell refers to a cell having a structure where a working electrode and a counter electrode are bonded on a transparent conductive substrate, and an 1/I 3 -based electrolyte is filled between the working electrode and the counter electrode. The working electrode is typically coated with a semiconductor oxide thick film such as TiO 2 onto which a Ru-based dye capable of absorbing light is adsorbed, and the counter electrode is coated with a catalyst electrode using Pt.
[0007] Since the dye sensitized solar cell has low manufacturing cost, is available for manufacturing a transparent conductive substrate, and is available for manufacturing solar cells having various designs, substantial research on the dye sensitized solar cell has been continuously performed and the dye sensitized solar cell has been substantially applied to various fields. In particular, the dye sensitized solar cell has been introduced substantially to a roof or a window of a building for the BIPV. In addition, the dye sensitized solar cell has been currently applied to a roof of a vehicle instead of the silicon solar cell.
[0008] The dye sensitized solar cell is mostly applied in the form of a plane module, and the application of a flexible dye sensitized solar cell to a curved point of a bag or a cloth has not been frequently attempted. Indeed, the plane module may not be applied to a curved structure of a vehicle due to a design of the curved structure.
[0009] Although various designs have been gradually applied to the vehicle by mounting a plane substrate or the flexible dye sensitized solar cell, a design may be degraded.
[0010] Accordingly, development of a curved structure or design of the dye sensitized solar cell is demanded to apply the dye sensitized solar cell to such as a vehicle, without losing performance of photovoltaic conversion of solar energy.
[0011] When a roof panel of a vehicle is connected with a solar cell module manufactured on a substrate which does not have the same curvature or has a plane surface as shown in {circle around (a)} of FIG. 1 , the roof and the solar cell may not contact closely to each other, such that separation may incur, thereby degrading mechanical stability and an aesthetic appearance. Otherwise, electrical resistance generated when bonded parts between modules are not in close contact with each other may be generated due to a curvature difference as shown {circle around (b)} of FIG. 1 .
[0012] In the related art for a modified solar cell panel, a configuration that a stacked solar cell module is heated and compressed between two metal plates in a heated state in the range of about 80° C. to 200° C. and a vacuum state, and then compressed between two curved dyes has been provided.
[0013] In the related arts, a molding method of mounting a pair of conductive film glass plates on a curved form has also been provided such that outer peripheral portions of the pair of conductive film glass plates may be supported by an outer peripheral portion of the curved form. The method may further include heating and bending the pair of conductive film glass plates into a desired shape.
[0014] In addition, a method of manufacturing a glass for a vehicle material has been developed. The method indicates that first and second glass substrates may be simultaneously bent so as to have a predetermined 3D curved shape when the first and second glass substrates are polymerized.
[0015] Moreover, a method of manufacturing a solar cell module for a sun roof of a vehicle has been introduced and in the method, a laminating operation for bonding a curved glass of a sun roof and a solar cell may be performed through a floor plate of a laminator device manufactured such that the floor plate may have the same curvature as the curved glass of the sun roof. However, the aforementioned technologies may not be suitable to a roof of a vehicle having various curvatures.
[0016] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
[0017] In a preferred aspect, the present invention can address one or more of the above-described technical difficulties in close-contact between the roof panel and the solar cell module. In particular, the present invention provides a method of manufacturing a curved solar cell module which may closely contact a curved roof panel of a vehicle without incurring separation when the solar cell module is attached to the curved roof panel. Accordingly, stress applied to the module may be minimized by manufacturing the curved solar cell module having the same curvature as the roof panel.
[0018] In one aspect, the method of manufacturing a curved dye sensitized solar cell for a vehicle may include steps of: (i) forming a first substrate by fabricating a transparent conductive layer on a plane thin film glass substrate and then forming a photoelectrode or a counter electrode of the dye sensitized solar cell; (ii) bending the first substrate where the photoelectrode or the counter electrode are formed, such that the first substrate has the same curvature as a roof panel of the vehicle by using a first curved zig (zig 1 ); (iii) applying an outer bonding agent on the curved first substrate; (iv) bending a second substrate such that the second substrate has the same curvature as the first substrate by using a second curved zig (zig 2 ); and (v) providing the second substrate on the first substrate and hardening the outer bonding agent between the substrates in the curved state.
[0019] The curved module manufactured by the method of the present invention may have advantages compared to the related art. For example, as shown in FIG. 1 , degradation of mechanical stability and an aesthetic appearance due to failure of close contact between a roof and a solar cell and generation of separation when the roof panel is connected with the solar cell module manufactured on a plane substrate may be eliminated. In addition, electrical resistance generated when bonded parts between modules are not in close contact with each other due to a curvature difference may be reduced, and thus performance of the solar cell panel may be improved. Moreover, stress applied to the module by curving the module before the bonding may be minimized and different curved glass substrates may be manufactured according to different curvature of the roof panel in the vehicle for each position. Further, the curved module may be manufactured by using conventional electrode printing process equipment and forming an electrode on a plane substrate.
[0020] Further provided are vehicle roof panels comprise a dye sensitized solar cell obtained or obtainable from a method as disclosed herein. Also provided are vehicles including automotive vehicles that comprise a vehicle roof panel that comprises a dye sensitized solzr cell as disclosed herein.
[0021] Other aspects and preferred embodiments of the invention are discussed infra.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above and other features of the present invention will now be described in detail with reference to various exemplary embodiments thereof illustrated in the accompanying drawings which are given hereinbelow by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0023] FIG. 1 illustrates a bonded state of a panel of a general plane module in the related arts;
[0024] FIG. 2 illustrates an exemplary method of manufacturing an exemplary curved solar cell module according to an exemplary embodiment of the present invention;
[0025] FIG. 3 illustrates an exemplary process where an exemplary curved solar cell module is bonded with a curved roof panel according to an exemplary embodiment of the present invention; and
[0026] FIG. 4 illustrates an exemplary method using an exemplary substrate incurvating apparatus.
[0027] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
[0028] In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION
[0029] It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.
[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0031] Hereinafter reference will now be made in detail to various exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
[0032] The present invention provides a method of curving a dye sensitized solar cell for a vehicle. The method may include steps of: (i) fabricating a first substrate by forming a transparent conductive layer on a plane thin film glass substrate and then forming a photoelectrode or a counter electrode of the dye sensitized solar cell; (ii) bending the first substrate where the photoelectrode or the counter electrode is formed, such that the first substrate has the same curvature as a roof panel of a vehicle by using a first curved zig (zig 1 ); (iii) applying an outer bonding agent on the curved first substrate; (iv) bending a second substrate such that the second substrate has the same curvature as the first substrate by using a second curved zig (zig 2 ); and (v) putting the second substrate on the first substrate and hardening the outer bonding agent between the substrates in the curved state ( FIG. 2 ). In particular, each process may be performed under a processing condition where the curved form of each substrate may maintain after the curved zigs are removed.
[0033] Alternatively, steps of (iii) and (iv) may be performed in reversed order. Meanwhile, one or more spacers may be coated on an edge portion of the zig, and one or more apertures for injecting an electrolyte may be processed in the first substrate mounted on the first zig. The spacer may be shaped like a pin such that the spacer may be disposed in the aperture for injecting the electrolyte. Alternatively, the spacers may be U shaped having one open end.
[0034] The first substrate and the second substrate may be coaxially or biaxially bent, the number of curvatures may be applied at two or more positions, and a radius of the curvature may be from about 2 to about 9 m.
[0035] The first zig or the second zig may vacuum adsorb and support the substrate, and the edge of the zig may have a ring-shaped structure holding the substrate such that the substrate may be prevented from being plane. The spacers made of an elastic material, such as silicon, rubber, or resin, may be coated on the edge of the zig.
[0036] The pin-shaped spacers passing through the apertures for injecting the electrolyte of the first substrate may be disposed in the first zig, and a diameter of the pin-shaped spacer may be of about 2 mm or less. A material of the pin-shaped spacer may be selected from the group consisting of silicon, rubber, resin, and Teflon.
[0037] The outer bonding agent may be, but not limited to, a photocurable or thermosetting epoxy or silicon adhesive.
[0038] A magnitude of stress applied by the curved surface of the curved dye sensitized solar cell module may be of about the stress of one sheet of the thin film glass substrate.
[0039] FIG. 3 illustrates an exemplary curved module which is bonded with a curved roof panel according to an exemplary embodiment.
[0040] In FIG. 4 , a vacuum adsorbing apparatus may be included in each of the upper and lower zigs, such that the substrate may be curved while being adsorbed onto the zigs.
[0041] The edge portion of the zig may have a shape to hold the substrate such that the substrate may be prevented from being plane, and may be coated with one or more spacers made of an elastic material, and the like, thereby serving to maintain an interval between the upper and lower substrates and preventing the substrates from being damaged. The apertures for injecting the electrolyte may be processed in the first substrate mounted on the first zig or the lower zig (zig 1 ). Accordingly, the pin-shaped spacers passing through the apertures may uniformly maintain the intervals between the first and the second substrates, or alternatively, between the upper and lower substrates.
[0042] The invention has been described in detail with reference to exemplary embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
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Disclosed is a method of manufacturing a curved a solar cell module which is closely contacting a curve roof panel of a vehicle without incurring separation when the solar cell module is attached to the curved roof panel for a vehicle. Accordingly, stress applied to the curved solar cell module by the curved surface may be minimized by fabricating a curved solar cell module having the same curvature as the roof panel to provide a close-contact problem between the roof panel and the solar cell module.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to a heating/cooling system featuring a buffer tank, and more particularly to such a system employing a split buffer tank configured to separate hot heat source provider flow return from warm secondary system flow return.
BACKGROUND OF THE INVENTION
[0002] To better illustrate the nature of the invention, take for instance the case of a condensing boiler as a heat source provider (HSP). It is common to find all variety of brands and models operating at steady-state-efficiency levels from 70-80% for non-condensing to 82-98% for condensing. Steady-state Efficiency—refers to a measuring parameter for boiler maximum efficiency capability assessed under a controlled steady test and carried out by recognizable standard certification bureau. In the test, parameters such as air-intake temperature and volume, air/gas mixture, water/brine temperature/flow entering/leavening the boiler, system heat demand, and some others, are all fixed during boiler firing to obtain a better judgment of its efficiency at artificial steady state conditions. Test Standards for Gas-Fired Boilers. CGA P.2-1991 (R1999)/ENERGY START Canada, and the U.S. Department of Energy's/Title 10/Code of Federal Regulations for the Energy Conservation Program for Consumer Products, make indications that during the steady state testing of a condensing boiler water outlet temperature shall be at 180° F./82° C. and inlet temperature shall be at 80° F./26.7° C. at all times.
[0003] Drifting away from the stationary conditions dictated by the test, it arrives at the real world, a different place. A world loaded with always changing conditions where lab subsets are not so frequently encountered during the operating life span of the boiler. To complicate matters, there appears the need for adding buffer capacity in order to eliminate problems associated with excessive cycling, poor temperature control, and erratic system operation. The HVAC industry learned a long time ago that it was by adding a buffer tank to the boiler-system that they resolved all these problems. However, one issue remains unsolved. That is, the loss of the boiler high efficiency during continuous operation due to the water mixing inside the tank. But with no solution on hand, they were forced to look the other way.
[0004] In today's commercial buffers (See FIG. 2 ), boiler water-return at temperature t b and secondary system water-return at temperature t s easily get mixed in the buffer because of the lack of mechanical medium capable of isolating the encountering of the two flows inside the tank (See also FIG. 4 ). This mixed water at temperature equal t mix when going to the boiler produces the same effect on efficiency behavior as the one depicted in FIG. 3 . There, and independent study (by Jim Cooke) shows how condensing and non-condensing boilers thermal efficiency gets influenced by water return temperature during steady-state conditions. Cooke's study also shows thermal efficiency behavior for a condensing boiler at three different firing rates (33/67/100%).
[0005] FIG. 4 shows some water/brine supply/return hydraulic connections for some brand name buffer tanks and their prevailing flow pattern when all intakes/outlets are in used. Water/brine motion inside the buffer not only gets affected by physical characteristics of the system such as pumps flow, buffer diameter and height, inlet/outlet configuration, among other variables, but also by changing set of dynamic conditions regulated by DCS (Distributed Control System). Flow patterns in the buffer are chaotic and unpredictable with limited opportunities for creating stratification conditions. For this to occur pumped flow coming from HSP/boiler and/or secondary system need to be slowed down to such extent that entering speed must be close to laminar flow. Only such minimal disturbance in the body of water inside the tank will have no major mixing effect in the natural convection phenomenon associated with stratification. From a design stand point this may lead to uneconomical alternatives such as having a much bigger diameter for piping inlet/outlet connections, otherwise designed with acceptable velocity of 2.1±0.9 m/s (7±3 ft/s) for normal liquid service applications, with maximum velocity of 2.1 m/s (7 ft/s) at piping discharge points. Perhaps even requiring a buffer tank with oversize uneconomical dimensions in diameter and/or height. This, without mentioning the time factor to allow the stratification process to evolve and settled in a constant demand HVAC system.
[0006] The more realistic assumption is that any flow leaving the buffer will do so at a temperature t mix .
[0007] From FIG. 2 and FIG. 4 it may be concluded that:
[0000] t mix =( t b +t s )/2 t b Water/brine temperature at boiler outlet. Considered equal to t 1 (See FIG. 1 ) when no heat losses occur in pipe connection between boiler and buffer t s Water/brine temperature at system return. Considered equal to t 2 (See FIG. 1 ) when no heat losses occur in pipe connection between system and buffer t mix Water/brine temperature from the mixture of warm and hot water if there is no separation disk (as it happens in existing commercial buffers). Water temperature going to the boiler t 1 Water temperature from hot section of the buffer to the secondary system t 2 Water temperature from Secondary System to warm section of the buffer t 1 -t 2 Delta temperature. Q=W×C p ×(t 2 −t 1 ) Q Secondary system heat demand. Q=W×C p ×(t 2 −t 1 )
[0015] Using data results from chart on FIG. 3 and applying the same analogy to evaluate water return/supply configuration on boiler efficiency for the typical commercial buffer connections on FIG. 4 ; It may be proven that when water gets mixed in the buffer and returned to the boiler at mixed temperature t mix , it will produce the same effect on the thermal efficiency of the boiler. As flow pattern and temperature of the mix evolve over time, the rising temperature of the water/brine will increasingly hamper its ability to quickly regain thermal energy when recirculating through the boiler, resulting in longer less efficient runs with increasingly unnecessary consumption of energy resources (See FIG. 6 ). This in turn will force chimney gases to escape the boiler without fully rendering their caloric load.
[0016] When dealing with condensing boilers it is crucial to realize that continuous 80° F./26.7° C. water-return and below is the determinant factor in achieving continuous outstanding higher efficiencies (See chart on FIG. 3 ); and that, boilers serving a buffer/system in which mixed water return temperature does not fall below 80° F./26.7° C. will never meet the necessary temperature requirements for achieving such continuous performance. Ignoring this fact, when justifying a boiler selection, will result in having a boiler that cost 50% more than necessary (comparing to condensing boiler) and achieves, from time to time, just above condensing boiler performance.
[0017] Currently buffer technology has not corrected the problems created with usual configurations such as the one on FIG. 4 (and the like); and as a result, its usage just exacerbate the sub-utilization of condensing boilers in boiler/buffer/systems that ONLY occasionally allow condensation to occur.
SUMMARY OF THE INVENTION
[0018] According to a first aspect of the invention there is provided a heating/cooling system operating on the basis of a novel split buffer tank comprising a separations disk, a guide bar adapted inside the split buffer tank to freely allow the separation disk to move up and down along the guide bar to make room for hot and warm fluid storage on opposite sides of the disk, two disk flow bypasses for respective loop flow functionality between the split buffer tank and each of a heat source provider and a secondary system, and hydraulic connections to interconnect the heat source provider and the secondary system to the split buffer tank.
[0019] Preferably the heat source provider is hydraulically connected to the split buffer tank.
[0020] Preferably the secondary system ( 14 ) is hydraulically connected to the split buffer tank.
[0021] Preferably buffer heat source provider return line serves as hydraulic connection to convey hot fluid from the heat source provider into a hot section of the split buffer tank on a hot side of the disk.
[0022] Preferably a buffer heat source provider supply line serves as hydraulic connection to convey warm fluid from a warm section of the split buffer tank on a warm side of the disk to the heat source provider.
[0023] Preferably a buffer system supply line serves as hydraulic connection to convey hot fluid from a hot section of the split buffer tank on a hot side of the disk to the secondary system.
[0024] Preferably a buffer system return line serves as hydraulic connection to convey warm fluid from the secondary system to a warm section of the split buffer tank on a warm side of the disk.
[0025] Preferably the split buffer tank ( 1 ) comprises the following:
(a) a hot-outlet hydraulically connected to a buffer system supply line to convey stored hot fluid from the split buffer tank to the secondary system to satisfy demand for heat; (b) a warm-inlet hydraulically connected to a buffer system return line to convey secondary system return warm fluid to split buffer tank for storage; (c) a hot-inlet hydraulically connected to a buffer heat source provider return line to convey hot fluid from the heat source provider to the split buffer tank for storage; (d) a warm-outlet hydraulically connected to a buffer heat source provider supply line to convey stored warm fluid from the split buffer tank to the heat source provider for reheating; (e) the separation disk, which functions to hydraulically separate hot fluid inflow from the heat source provider from warm fluid inflow from the secondary system, and to serve as an insulating wall for thermal separation between hot and warm sections of the tank, the separation disk comprising the following:
i) an insulating core which functions to thermally insulate the hot section of the split buffer tank from the warm section; ii) a separation disk warm-side bypass to allow a pump- 1 to recirculate fluid in a system loop during positioning of the disk in a top position; iii) a separation disk hot-side bypass to allow pump- 2 to recirculate fluid in a heat source provider loop during positioning of the disk in a bottom position; and iv) a pressure release check valve hydraulically connecting a hot face of the disk with a warm face of the disk in order to eliminate pressure differential between the hot and warm sections of the tank that may arise from a make-up fluid connection on the split buffer tank;
f) the guide bar, which is a center guide squared bar to guide the separation disk up and down along the split buffer tank and to prevent rotation of the disk from causing misalignment of the warm-side bypass with the hot outlet ( 8 ), or the hot-side bypass with the warm outlet ( 11 ), at an edge of the separation disk, the disk being displaceable up and down along the center guide bar to allow hot and warm fluid accumulation during thermal recharging and discharging of the split buffer tank; g) a separation disk hub to secure the separation disk to the center guide bar and to accommodate a set of counterweight plates; h) the set of counterweight plates balancing buoyancy of the separation disk to make the separation disk effectively weightless when placed in the fluid medium inside the split buffer tank; i) a top position disk stopper to limit displacement of the disk when going to the top position lining up the warm-side bypass with the hot outlet; j) a bottom position disk stopper to limit displacement of the disk when going to the bottom position, lining up the hot side bypass with the warm outlet; k) a guide bar attachment to mechanically secure the guide bar to a bottom of the split buffer tank; and l) a pressurized fluid make-up & air vent connection to maintain continuous fluid supply to the system and to allow for allocation of air vent equipment in association with the split buffer tank.
[0042] Preferably there is provided a Distributed Control System (DCS) logic that is arranged to work independently or in conjunction with additional DCS controllers and comprises the following:
a) a demand-based sensor/selector inside the Secondary System perimeter which functions to monitor an inner temperature and call for heat, starting a Pump- 1 operable between the buffer tank and the secondary system, if the inner temperature falls below a preset value; b) a fluid temperature sensor/selector located at a buffer system supply line, between a hot outlet of the buffer tank and the pump- 1 , the temperature sensor/selector registering a first point fluid temperature, operating only when the pump- 1 is ON, and if the first point fluid temperature falls below a set point, signaling to start first a pump- 2 operable between the buffer tank and the heat source provider and, with a time delay, start the heat source provider to reload the split buffer tank with hot fluid; and c) another fluid temperature sensor/selector located at a buffer heat source provider supply line, between a buffer tank warm outlet and pump- 2 to register a second point fluid temperature and shut-off the pump- 2 , and with time delay, shut off the heat source provider if the second point fluid temperature rises to a second preset value.
[0046] The split buffer tank is preferably insulated to retain heat, provided with medium to high pressure capabilities and suitable to operate at higher than normal temperatures.
[0047] The heat source provider may feature any direct heating device such as gas/oil boiler, heat pump, solar plant (solid fuel), wood pellet/log and/or any district heating, or indirect heating device operated via integrated heat exchangers or external flat plate heat exchanger.
[0048] The secondary system may feature any HVAC applications for office buildings, industrial facility or any other closed environment, where safe and healthy building conditions are regulated with temperature and humidity, as well as “fresh air” from outdoors. Also any industrial thermal processes involving cooling/heating applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] In the following drawings, which illustrate the exemplary embodiments of the present invention:
[0050] FIG. 1 schematically illustrates a heating/cooling system operating with the novel invention of a split buffer tank
[0051] FIG. 2 schematically illustrates a prior art boiler/system operating with an existing commercial buffer tank
[0052] FIG. 3 shows a simplified chart for condensing and non-condensing boilers steady-state thermal efficiency as function of return water temperature
[0053] FIG. 4 schematically illustrates prior art water/brine supply/return hydraulic connections for some commercial buffer tanks showing prevailing flow patterns.
[0054] FIG. 5 shows boiler/buffer/system connections effect on time thermal efficiency
[0055] FIG. 6 shows split buffer Vs commercial buffer connection effect on energy savings
[0056] FIG. 7 a schematically illustrates a commercial buffer tank connection for a geothermal heat pump.
[0057] FIG. 7 b schematically illustrates a split buffer tank connection for a geothermal heat pump
[0058] FIG. 8 shows geothermal heat pump/buffer/system connection effect on energy savings
[0059] FIG. 9 is a cross-sectional view of a split buffer/separation disk operating at a top position
[0060] FIG. 10 is a cross-sectional view of the split buffer/separation disk operating at a bottom position
[0061] FIG. 11 is a plan view of the separation disk
[0062] FIG. 12 shows separation disk hub details, including cross-sectional view A-A with details on counterweight plates and a pressure release check valve. Separation ring insulating core ( 2 a in FIGS. 9 & 10 ) is not shown, to simplify the drawings.
DETAILED DESCRIPTION
1. General Character of the invention
[0063] The present invention relates to a heating/cooling system operating on the basis of a SPLIT BUFFER TANK, as shown in FIG. 1 . Its design includes a mechanical disk ( 2 ) in order to separate the hot HSP flow return ( 19 ) from the warm secondary system flow return ( 15 ). Because both sections get thermally and hydraulically isolated one from each other, it favours the separation of the two bodies of water with different thermal properties. This in turn, allows the independent supply of water/brine to the secondary system at a steady high temperature serving the demand for heat, and steady low water/brine temperature to the HSP for reheating. Since steady state conditions for both flows are possible with this new invention, its use will maximize thermal operating efficiency for existing large sets of manufactured HVAC equipment. It alone will allow not only the step down on equipment sizes for a given set of thermal conditions, but also the decrease in the use of non-renewable natural resources and in the otherwise normally increasing maintenance costs. The HSP and the Secondary System work in a closed loop interconnected through the buffer/vessel. The term “water” or “brine” will be used indistinctively, meaning the fluid used within this closed loop. The name “System” is used herein to refer to the Secondary System, not the overall heating/cooling system.
2. Inventive Idea
[0064] In the case of the split buffer of the present invention (refer to FIG. 1 ), boiler water-return at temperature t b will never encounter system water-return at temperature t s . Therefore, a constant flow of water to the boiler at t 2 will remain unchanged throughout the heat-loading operation, allowing the boiler to perform at very stable conditions closely mimicking lab subsets. With boiler operating at continuous high efficiency levels, buffer reloading will be carried out in shorter periods with saving in non-renewable energy resources, and time operation will be minimized, reducing boiler wearing and operational costs. On the system side, because now water/brine to the system can be delivered at continuous targeted high temperature, system HVAC equipment will see a significant improvement in their thermal transfer units (because of higher log median temperature differential, or LMTD). This alone will favor downsizing when considering the use of split buffer during the initial phase of HVAC system design.
[0065] Additional desirable key features can be added to the system that now can operate at continuous buffer system delivery targeted temperature and work with much lower water return temperature to the boiler. For example, less volume of water/brine will be needed to be pumped in order to be capable of carrying a bigger load to the system, smaller piping diameter with reduced pressure drops can be used, smaller handling systems with reduced heat exchangers can be used, and it would make sense to put effort in designing a system with water return temperature as low as possible since its purpose will not be defeated by buffer mixing. And lastly, it would be expected to have a smaller required boiler capacity more responsive to system loads and less costly to operate.
[0066] FIG. 5 shows the hypothetical effect of boiler/buffer connection configuration on thermal efficiency for the three scenarios considered in FIG. 4 with some additional considerations. The same boiler with best/middle/worst connections arrangement now working in a time evolving water mixing situation where the slope in the chart will indicates the speed of change by which thermal efficiency drops down for a given best/middle/worst case scenario. The dashed line at 120 seconds marks the time at which such boiler will finish thermal loading when operating with a novel split buffer (280 seconds when operating with commercial buffer). It can be observed that the split buffer operation provides an advantage when compare to commercial buffers. The elimination of water return mixing allows it to consistently perform (at 98% efficiency) enabling thermal reloading in shorter boiler time operation, see FIG. 6 (with lower energy resource spending, more rapid system response and less mechanical maintenance cost on the boiler).
[0067] In the case of a water-to-water geothermal heat pump (GHP) (see FIG. 7 a , 7 b ), operating with any commercial buffers from FIG. 4 , GHP brine return at temperature t b and system brine return at temperature t s ; again, easily get mixed in the buffer because of the lack of mechanical medium capable of isolating the encountering of the two flows inside the tank. This mixed water at temperature equal t mix =(t b +t s )/2 when going to the GHP condenser or evaporator (depending on whether the GHP is in a heating mode—like that shown in FIG. 7 a , or a cooling mode) will produce an LMTD much lower than the one generated when operating with the split buffer ( 1 ), with no mix ( FIG. 7 b ). LMTD reduction will hamper the ability of the brine to quickly regain thermal energy and transport a higher load to the buffer in a shorter period of time; resulting, in longer GHP runs with increasing consumption of energy and equipment wearing. During buffer thermal loading operation, as t mix approaches t b , LMTD tends to zero making the heating transferring process to become more critical. At this time, the rate of heat transfer via condenser/evaporator to the GHP brine will approximate slowly to zero, forcing the GHP to operate for a longer period time until t mix =t b at time t 10 (See chart on FIG. 8 ), and the system shuts-off.
[0068] Split buffer ( 1 ) offers operational advantages to GHP due to the ability to maintain a constant flow of low water temperature (high water temperature during reverse cycle) going to the GHP evaporator accelerating heating-loading time. The results, a more efficient GHP operation with lower running time, less energy consumption and lower maintenance cost. Special consideration should be given to Split Buffer ( 1 ) Distributed Control System which now needs to be reconditioned in order to perform not only on heating but cooling reverse cycle.
[0069] Similar analysis may be carried out for other Heat Source Providers (HSP) as part of any HVAC system with the same positive improvement in their operation.
2.1. Sequence of Operation
[0070] Heating/cooling cycle for the system in FIG. 1 initiate with demand-based sensor/selector inside secondary system perimeter TS 0 ( 22 ) sensing the need for heat and sending a signal to start pump- 1 ( 13 ). At this moment in time, secondary system ( 14 ) temperature is below TS 0 ( 22 ) set point.
[0071] With Pump- 1 ( 13 ) running and water/brine flowing from split buffer ( 1 ) to secondary system ( 14 ), low temperature sensor/selector TS 1 ( 23 ) located at buffer hot outlet ( 8 ) registers point water temperature. If water/brine temperature is above set point, there will be no signal to start pump- 2 ( 17 ) and HSP/boiler ( 18 ). Split buffer ( 1 )/pump- 1 ( 13 ) will continue supplying hot water and pushing separation disk ( 2 ) toward the top position of the split buffer tank ( 1 ) shown in FIG. 9 until a warm-side bypass ( 3 a ) of the separation disk ( 2 ) gets aligned with hot outlet ( 8 ) of the buffer tank ( 1 ). At that point, pump- 1 ( 13 ) will recirculate warm water along system loop “split buffer ( 1 )→buffer system supply line ( 12 )→secondary system ( 14 )→buffer system return line ( 15 )→split buffer ( 1 )” via the warm side bypass ( 3 a ) until any excess heat remaining in the water is released into the secondary system ( 14 ) and TS 1 ( 23 ) registers a water temperature falling below set point. TS 1 ( 23 ) will then triggers on pump- 2 ( 17 ), and with time delay, HSP/boiler ( 18 ). Pump- 1 ( 13 ) will run continuously until secondary system ( 14 ) temperature reaches TS 0 ( 22 ) set point indicating that the demand for heat is mitigated.
[0072] Once demand in secondary system ( 14 ) gets satisfied, TS 0 ( 22 ) will shut off pump- 1 ( 13 ). HSP/boiler ( 18 )/pump- 2 ( 17 ) will continue running/loading split buffer ( 1 ) with hot water/brine until separation disk ( 2 ) reaches the bottom position of the split buffer tank ( 1 ) shown in FIG. 10 , aligning a hot-side bypass ( 3 b ) of the separation disk ( 2 ) with buffer warm-outlet ( 11 ) of the buffer tank ( 1 ). At that point, pump- 2 ( 17 ) will continue recirculating water along the HSP/boiler loop “split buffer ( 1 )→buffer HSP/boiler supply line ( 16 )→HSP/boiler ( 18 )→buffer HSP/boiler return line ( 19 )→split buffer ( 1 )” via the hot side bypass ( 3 b ) until water/brine temperature reaches high temperature sensor TS 2 ( 24 ) set point, dictated by the outdoor reset control ORC ( 28 ). TS 2 ( 24 ) then will shut-off HSP/boiler ( 18 ), and with time delay, pump- 2 ( 17 ). This will leave split buffer ( 1 ) thermally loaded and resting for the next cycle.
[0073] When running concurrently, pump- 1 ( 13 ) and pump- 2 ( 17 ) will create an operational valet on the separation disk ( 2 ) that now moves up and down inside the split buffer, obeying HSP/boiler ( 18 ) and secondary system ( 14 ) water flow demand and return. Both served by pump- 1 ( 13 ) and pump- 2 ( 17 ). Pump- 1 ( 13 ) and pump- 2 ( 17 ) operate concurrently with no discharge counterpressure (other than loop pressure losses) that forces any of the pumps to fight. Pump- 1 ( 13 ) is always discharging in the suction section of pump- 2 ( 17 ) and vice versa.
[0074] Low temperature sensor/selector TS 1 ( 23 ) will operate only when pump- 1 ( 13 ) is on. This prevents pump- 2 ( 17 ) and HSP/boiler ( 18 ) from operating when supply line ( 12 ) gets cold and the secondary system is not calling for heat.
[0075] Split buffer ( 1 ) thermal reloading cycle will not only be initiated by a new demand for heat for secondary system ( 14 ); but also, by additional high temperature sensor (TS 3 ) ( 25 ), added to split buffer ( 1 ) to maintain a high water/brine temperature during long resting periods. It should be used only if additional extra time for secondary system recovery is not allowed by the HVAC system. High temperature set point for TS 3 ( 25 ) is dictated by the outdoor reset control ORC ( 28 ).
[0076] Outdoor reset control ORC ( 28 ), is a commonly used microprocessor-based control designated to regulate supply water/brine temperature based on outdoor temperature. Automatic reset ratio calculation sets the relationship between outdoor temperature and supply water/brine temperature (heating curve) to provide optimum control and comfort. As the outdoor temperature changes, the control adjusts firing rate of the boiler or running time to compensate for exterior heat loss.
[0077] ORC ( 28 ) will automated high temperature set point for TS 2 ( 24 ) and (TS 3 ) ( 25 ). And because it matches heat loss from the secondary system with HSP/boiler required output, it will optimize energy conservation in a system that will operate at the lowest practical return water temperature.
2.2. Operation Notes
[0078] Bypass connection ( 3 a ) and ( 3 b ) in the separation disk ( 2 ) (as it is shown in FIG. 9 , 10 , 11 ) allow pumps to bypass flow during top or bottom disk positions. During top position ( FIG. 9 ), with pump- 1 ( 13 ) running, warm-side bypass ( 3 a ) will line up with hot outlet ( 8 ) allowing water/brine to freely recirculate along system loop. Once low temperature sensor TS 1 ( 23 ) registers recirculating water/brine temperature being below set point, it will start pump- 2 ( 17 ), and with time delay HSP/boiler ( 18 ), to reinitiate thermal loading. During bottom position ( FIG. 10 ) with pump- 2 ( 17 ) running, hot-side bypass ( 3 b ) will line up with warm outlet ( 11 ) allowing hot water/brine to freely recirculate along HSP/boiler loop. Once high temperature sensor TS 2 ( 24 ) registers recirculating water/brine temperature being on target, it will shut-off thermal reloading sending the system to a temporary rest. Both loops operate independently and complementing one another.
[0079] Top position disk stopper ( 26 ) and bottom position disk stopper ( 27 ) will limit the separation disk run along guide bar ( 7 ). During disk top position (see FIG. 9 ), it allows disk warm-side bypass ( 3 a ) to line up with hot outlet ( 8 ). During disk bottom position (see FIG. 10 ), it allows disk hot-side bypass ( 3 b ) to line up with warm outlet ( 11 ).
[0080] Each bypass curves through ninety degrees, first extending axially into the disk just inward from its circular cylindrical periphery and then turning through ninety degrees to extend radially out of the disk through the disks peripheral edge, which otherwise seals to the internal cylindrical surface of the tank's peripheral wall closing concentrically around the guide bar 7 . The radially opening end of the bypass communicates with the respective one of the supply lines ( 12 , 16 ) when one side of the disc, specifically the side of the disk opposite the other end of the bypass, seats against the respective stopper ( 26 , 27 ). This seating or stopping of the disc acts to block further sliding of the disk along the guide bar. The warm side bypass ( 3 a ) extends into the bottom face of the disk so as to fluidly communicate only with the warm water or brine and buffer warm inlet ( 9 ) below the disk, while the hot side bypass ( 3 b ) extends into the top face of the disk so as to fluidly communicate with the hot water or brine and buffer hot inlet ( 10 ) above the disk.
[0081] The guide bar ( 7 ) is illustrated as centrally positioned in the buffer tank and as having a square cross-section closely fitting in a similarly sized passage of square section extending through the hub of the disk so that a sliding seal is formed between the hub and the guide bar to prevent water or brine from crossing the disk from on side thereof to the other through the hub, while allowing sliding of the disk along the guide bar. The straight-sides of the square cross-sections of the tube and hub passage cooperate to prevent relative rotation between the two, thereby maintaining the bypass passages in the disk in the same radial planes of the tank and bar longitudinal axes as the respective outlets of the tank. It will be appreciated that other non-circular cross-sectional shapes can be used to establish such rotation-preventing cooperation between the disk and the guide bar. The guide bar and disk also cooperate to substantially maintain the orientation of the disk's plane relative to the bar's longitudinal axis to thereby keep the outer periphery of the disk near the inner periphery of the tank and thus minimize fluid leakage and mixing across the disc.
[0082] Because separation disk ( 2 ) and the insulating manufacturing material injected in the core ( 2 a ) of the disk will vary in density when compared to water/brine or any other liquid being used, weight balancing is carried out through a set of counterweight plates positioned in a hub ( 6 ) of the disk (as seen in FIG. 12 ) in order to counterbalance the buoyancy effect of the disk. The purpose is to make the disk as neutrally buoyant or effectively weightless as possible when placed inside the tank (Buoyant force−counterweight=0), eliminating its tendency to float to the top or sink to bottom position. This may happen when the system is resting for long period of time. In any case, split buffer will maintain its operability due to the configuration in hydraulic connections ( 12 ), ( 15 ), ( 16 ), ( 19 ) and to DCS instructions that maintains the appropriate sequence of operation at any disk position.
[0083] Separation disk is provided with pressure release check valve ( 5 ) (See FIG. 12 ) to balance any pressure differential that may arise from make-up water/brine feeding through the make-up/air vent connection line ( 20 ) (see FIG. 1 , 9 , 10 ). Pressure release check valve ( 5 ) allows forward flow from hot section atop to the warm section in the bottom and closes to block reverse flow. This allows achievement of a pressure balance across the disc, thereby preventing the disk from sinking when the system is resting.
[0084] Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.
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This invention relates to a heating/cooling system operating on the basis of a novel SPLIT BUFFER TANK; representing an efficiency improvement alternative to HVAC systems functioning with existing commercial buffer tanks. Currently, commercial buffers have the heat source provider (HSP)-return and system-return discharging to a common buffer/vessel. Novel SPLIT BUFFER is provided with a SEPARATION DISK placed inside the tank as mechanical way of separating the hot water inflow from the HSP from the warmer water inflow from system return. The disk moves up and down along the tank driven by demanded water supply and return. Pump- 1 circulates hot water from the hot section of the buffer to the secondary system claiming for heat. Pump- 2 circulates warmer water from the warmer section of the buffer through the HSP where it is reheated, and subsequently stored in the hot section of the buffer to reinitiate this cycle again.
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BACKGROUND OF THE INVENTION
The present application relates to compiling and reporting data associated with activity on a network server and more particularly to compiling and reporting server data that is associated with commercial activity on a server. This application is a continuation of U.S. Provisional Patent 60/163,710 filed Nov. 5, 1999 whose contents are incorporated herein for all purposes.
Programs for analyzing traffic on a network server, such as a worldwide web server, are known in the art. One such prior art program is described in U.S. patent application Ser. No. 09/240,208, filed Jan. 29, 1999, for a Method and Apparatus for Evaluating Visitors to a Web Server, which is incorporated herein by reference for all purposes. WebTrends Corporation owns this application and also owns the present provisional application. In these prior art systems, the program typically runs on the web server that is being monitored. Data is compiled, and reports are generated on demand—or are delivered from time to time via email—to display information about web server activity, such as the most popular page by number of visits, peak hours of website activity, most popular entry page, etc.
Analyzing activity on a worldwide web server from a different location on a global computer network (“Internet”) is also known in the art. To do so, a provider of remote web-site activity analysis (“service provider”) generates JavaScript code that is distributed to each subscriber to the service. The subscriber copies the code into each web-site page that is to be monitored. When a visitor to the subscriber's web site loads one of the web-site pages into his or her computer, the JavaScript code collects information, including time of day, visitor domain, page visited, etc. The code then calls a server operated by the service provider—also located on the Internet—and transmits the collected information thereto as a URL parameter value. Information is also transmitted in a known manner via a cookie. Each subscriber has a password to access a page on the service provider's server. This page includes a set of tables that summarize, in real time, activity on the customer's web site.
The above-described arrangement for monitoring web server activity by a service provider over the Internet is generally known in the art. Information analyzed in prior art systems, however, consists of what might be thought of as technical data, such as most popular pages, referring URLs, total number of visitors, returning visitors, etc. However, the need still remains for a way to track and report commercial activity on the web site—a feature missing in prior art web commerce analysis tools.
SUMMARY OF THE INVENTION
A methods and apparatus is disclosed for tracking and reporting electronic commerce activity over a web site that is stored on a first server coupled to a wide area network. The web page is programmed to include data fields reflecting commerce transaction activity and data mining code. The web page is uploaded to a visitor computer responsive to a request over the wide area network from the visitor computer. Commerce information is accepted within the data fields of the web page at the visitor computer to form a completed web page. The data mining code is operated on the visitor computer to obtain technical and commercial data and sent to a second server on the wide area network for logging and analysis.
The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention that proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a portion of the Internet on which the invention is operated.
FIG. 2 is an illustration of a conventional web page order form including embedded programmatic code operable to gather commercial activity according to the invention.
FIG. 3 is an example of a report showing revenue trends over time throughout a business day as tracked and reported by the present invention.
FIG. 4 is an example of a report showing revenue by product over a month's period as tracked and reported by the present invention.
FIG. 5 is an example of a report showing revenue trends at a particular web site over the course of an entire year for five different products as tracked and reported by the present invention.
DETAILED DESCRIPTION
Turning now to FIG. 1 , indicated generally at 10 is a highly schematic view of a portion of the Internet. FIG. 1 depicts a system implementing the present invention. Included thereon is a worldwide web server 12 . Server 12 , in the present example, is operated by a business that sells products via server 12 , although the same implementation can be made for sales of services via the server. The server includes a plurality of pages that describe the business and the products that are offered for sale. It also includes an order page, like the one shown in FIG. 2 , that a site visitor can download to his or her computer, like computer 14 , using a conventional browser program running on the computer. The order form typically contains—for products—the national currency that the seller accepts, an identification of the product, the number of products sold, and the unit price for each product. After a site visitor at computer 14 fills in the information in FIG. 2 , the visitor actuates a screen-image button 15 that places the order by transmitting the information from computer 14 to server 12 over the network. Upon receipt of this information, server 12 typically confirms the order via email to computer 14 . The seller then collects payment, using a credit-card number provided in the FIG. 2 form, and ships the product.
As mentioned above, it would be advantageous to the seller to have an understanding about how customers and potential customers use server 12 . As also mentioned above, it is known to obtain this understanding by analyzing web-server log files at the server that supports the selling web site. It is also known in the art to collect data over the Internet and generate activity reports at a remote server.
When the owner of server 12 first decides to utilize a remote service provider to generate such reports, he or she uses a computer 16 , which is equipped with a web browser, to visit a web server 18 operated by the service provider. On server 18 , the subscriber opens an account and creates a format for real-time reporting of activity on server 12 .
To generate such reporting, server 18 provides computer 16 with a small piece of code, typically JavaScript code (data mining code). The subscriber simply copies and pastes this code onto each web page maintained on server 12 for which monitoring is desired. When a visitor from computer 14 (client node) loads one of the web pages having the embedded code therein, the code passes predetermined information from computer 14 to a server 20 —also operated by the service provider—via the Internet. This information includes, e.g., the page viewed, the time of the view, the length of stay on the page, the visitor's identification, etc. Server 20 in turn transmits this information to an analysis server 22 , which is also maintained by the service provider. This server analyzes the raw data collected on server 20 and passes it to a database server 24 that the service provider also operates.
When the subscriber would like to see and print real-time statistics, the subscriber uses computer 16 to access server 18 , which in turn is connected to database server 24 at the service provider's location. The owner can then see and print reports, like those available through the webtrendslive.com reporting service operated by the assignee of this application (examples of which are shown in FIGS. 3-5 ), that provide real-time information about the activity at server 12 .
The data mining code embedded within the web page script operates to gather data about the visitor's computer. Also included within the web page script is a request for a 1×1 pixel image whose source is server 20 . The 1×1 pixel image is too small to be viewed on the visitor's computer screen and is simply a method for sending information to server 20 , which logs for processing by server 22 , all web traffic information.
The data mined from the visitor computer by the data mining code is attached as a code string to the end of the image request sent to the server 20 . By setting the source of the image to a variable built by the script (e.g. www.webtrendslive.com/button3.asp? id39786c45629t120145), all the gathered information can be passed to the web server doing the logging. In this case, for instance, the variable script “id39786c45629t120145” is sent to the webtrendslive.com web site and is interpreted by a decoder program built into the data analysis server to mean that a user with ID#39786, loaded client web site #45629 in 4.5 seconds and spent 1:20 minutes there before moving to another web site.
As will now be explained, applicant has developed the ability to analyze commercial data as well, e.g., number of orders, total revenues, etc., generated by server 18 , and attach that information to the variable script image request so that commercial activity for a particular site can be tracked.
To this end, applicant has developed a method in which data relating to revenues, products sold, categories of products, etc., is collected, analyzed and displayed in various report formats. An example of code that can be used to implement this method is shown in Appendices I and II. When the subscriber opens an account with the service provider by connecting computer 16 to server 18 , as described above, the code in Appendices I and II is transferred from service 18 to computer 16 in a known manner. The subscriber then determines which pages on the server 12 web site he or she would like to track. The subscriber then opens a text editor for each page to be tracked, and the code from Appendix I is pasted into the bottom of the page. Although the code in Appendix I does not provide an image on the page, it should be appreciated that code that includes an image such as a logo or the like, could be included in the Appendix I code. This would consequently both track the page and display an image thereon.
After the Appendix I code is pasted onto each page to be tracked, including an order confirmation page, the code in Appendix II, which defines a variable called ORDER, is also pasted onto the order confirmation page. This variable appears on line 7 of the Appendix I code.
The variable ORDER, among other things, defines the currency that is used to purchase the product. The currency need only be entered once, and in the example is USD for U.S. dollars. There are four other items that are included in the variable for each product ordered. In the order appearing in the variable they are first, the product name; second, the category that the product is in; third, the number of products purchased; and fourth, the unit price for the product. As can be seen in the Appendix II code, each item of information in the ORDER variable is included for each product purchased.
In operation, a site visitor using computer 14 first fills in all the information in the FIG. 2 form. The visitor then clicks button 15 in FIG. 2 , and an order confirmation page (not shown) appears that includes the product, category, number, and unit price information, for each product ordered. The code in Appendices I and II collect this information, along with the usual data relating to traffic, visitors, visitors' systems, etc., and transmits it to service 20 . This data is analyzed on server 22 as described above and stored on database 24 .
An example of this process is described as follows. The variable image source constructed by the inserted commercial activity tracking script can be shown as, for instance, www.webtrendslive.com/button3.asp?usd-lawn_chair# 1-1445-002-2499, corresponding to price in U.S. dollars, product name: “lawn chair #1”, product category #1445, 2 units sold at a per unit price of $24.99. Decoder software operable within server 22 reverse engineers the order to extract commercial activity data based on the source of the image requests.
When the business owner operating the website on server 12 wants to determine activity on that site, he or she logs onto his or her account on web server 18 via computer 16 . After entering the appropriate user name and password, reports that are maintained in real time, as described above, are accessed, viewed, and—if desired—printed by the subscriber. Examples of various reports are shown in FIGS. 3-5 and are available through the webtrendslive.com reporting service, operated by the assignee of this application.
In addition to viewing the reports that are maintained in real time, the account owner can define time periods during which the information can be displayed in the format shown in the enclosed reports. There is also a feature that the account owner can select to cause reports to be periodically mailed to computer 16 .
Having described and illustrated the principles of the invention in a preferred embodiment thereof, it should be apparent that the invention can be modified in arrangement and detail without departing from such principles. We claim all modifications and variation coming within the spirit and scope of the following claims.
APPENDIX I
1: <!--- Copyright 1999 WebTrends Corporation --->
2: <!--- http://www.webtrends.com --->
3: <!--- Modification of this code is not allowed and will permanently disable your account --->
4: <script language=“JavaScript1.2”>
5: <!---
6: var code = “ ”;
7: var ORDER = “<% ORDER %>”
var SERVER = “ ”;
8: var title = escape(document.title);
9: var url = window.document.URL;
10: var orderstr = escape(order);
11: var get = “http://stats.webtrendslive.com/scripts/enterprise.cgi”;
12: get += “?sid=000-99-9-7-27-7349&siteID=232”;
13: get += “&title=” + title + “&url=” + url;
16: document.write(“<” + “script src=‘” + get + “’></script>”);
17: //-->
18: </script>
19: <script language=“JavaScript1.2”>
20: document.write(code);
21: document.write(“<” + “!---”); </script>
22: <img src=“http://stats.webtrendslive.com/scripts/enterprise3.cgi?si d=000-99-9-7-27-
23: 7349&siteID=232&url=”>
24: <script language=“JavaScript1.2”>
25: document.write(“---” + “>”);
26: </script>
27: <noscript>
28: <img src=“http://stats.webtrendslive.com/scripts/enterprise3.cgi?si d=000-99-9-7-27-29: 7349&siteID=232&url=”>
30: </noscript>
31: <--- End of WebTrends Counter insertion --->
APPENDIX II
<%
ORDER = “D1;”
FOR i = 0 to UBOUND(orders)
ORDER = ORDER + product(i) & “,” & category(i) >>
& “,” & number_sold(i) & “,” & unit_price(i)>>
& “;”;
NEXT
(‘>>’ indicates line continues)
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A method and apparatus is disclosed for tracking and reporting electronic commerce activity over a web site that is stored on a first server coupled to a wide area network. The web page is programmed to include data fields reflecting commerce transaction activity and data mining code. The web page is uploaded to a visitor computer responsive to a request over the wide area network from the visitor computer. Commerce information is accepted within the data fields of the web page at the visitor computer to form a completed web page. The data mining code is operated on the visitor computer to obtain technical and commercial data and sent to a second server on the wide area network for logging and analysis.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a division of application Ser. No. 11/032,310 filed 9 Jan. 2005 (U.S. Pat. No. 7,571,741 issued 11 Aug. 2009). This application further claims the benefit of U.S. Provisional Application No. 60/535,463, filed 9 Jan. 2004, and U.S. Provisional Application No. 60/579,921, filed 14 Jun. 2004, and is a continuation-in-part of the following provisional and nonprovisional applications: Ser. No. 10/647,603, filed 25 Aug. 2003; Ser. No. 10/744,708, filed 23 Dec. 2003; Application No. 60/535,463, filed 9 Jan. 2004; and any of their predecessor applications.
REFERENCE REGARDING FEDERAL SPONSORSHIP
[0002] Not Applicable
REFERENCE TO MICROFICHE APPENDIX
[0003] Not Applicable
[0004] 1. Field of the Invention
[0005] The present invention relates to a flow trap, such as a cartridge used in water-free urinals having an odor preventing closure mechanism and, in particular, to improvements in the internal liquid flow path and sealant integrity of such a cartridge and, additionally, to improving flow trap life and usability, including a reduction in the need for the servicing and replacement of such cartridges.
[0006] 2. Description of Related Art and Other Considerations
[0007] In existing water-free urinals, the life and usability of cartridges employed in water-free urinals has been found to be dependent, in part, upon the need for their servicing and replacement when debris and matter are deposited therein. For example, in the cartridges described in U.S. Pat. Nos. 6,053,197, 6,245,411, 6,644,339 and 6,______ [Ser. No. 09/855,735 (filed 14 May 2001)] and U.S. patent application Ser. No. 10/143,103 (filed 7 May 2002), as the liquids flow from the inlet compartment to the outlet compartment and thence to an external drain, the flow is sufficiently gentle that solid matter contained in the fluid deposits in the pan of the bottom portion and eventually builds up to block flow from the inner compartment to the outlet compartment. As a consequence, the cartridge needs to be replaced. Further, it has been observed that unequal pressures between the two compartments create syphoning therebetween and, particularly, of syphoning of sealant from the inlet compartment to the outlet compartment, which leads to premature failure and a reduction in the usable life of the cartridge.
SUMMARY OF THE INVENTION
[0008] These and other problems are successfully addressed and overcome by the present invention, along with attendant advantages, by equalizing the pressures and by increasing the flow rate between the inlet and outlet compartments. Such pressure equalizing is effected preferably by establishing substantially equal volumes in the two compartments and, specifically, by use of a separator. Such increased flow rate is effected by use of a baffle positioned at the bottom of the cartridge adjacent the pan, which baffle is so configured as to provide a constriction that increases the flow velocity of the urine and thus to use the fluid flow to effect a flow path or channel of least resistance through any solid matter in the bottom pan and thus to remove or carry away or displace solids that may be or have been in the wastewater or urine and thus not deleteriously affect or otherwise substantially deter flow into the outlet compartment. Such action may also otherwise avoid the build up of deposits on the bottom portion. In addition, it is preferred to locate the entry to the inlet compartment centrally of the cartridge so that a diverter may be placed above the entry and thereby to create a circuitous path for preventing turbulence or a disturbing impingement of the urine onto the sealant contained in the inlet compartment. To accommodate the centrally placed entry and its placement vis-a-vis the inlet compartment, the separator is bowed at its location adjacent the entry and towards the outlet compartment. To fit the configuration of the baffle, the separator is curved generally in a likewise manner.
[0009] Several advantages are obtained derived from these arrangements. The life and usability of the cartridge is extended. Sealant is conserved. Deposits of solid matter within the cartridge are at least minimized. Of importance, the fluid flow effects a flow path or channel of least resistance through any solid matter in the bottom pan.
[0010] Other aims and advantages, as well as a more complete understanding of the present invention, will appear from the following explanation of an exemplary embodiment and the accompanying drawings thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a flow trap cartridge usable in a water-free urinal;
[0012] FIG. 2 is an exploded view, in perspective, of the cartridge shown in FIG. 1 ;
[0013] FIGS. 3-6 are, respectively, two side views taken 180° from one another, a top view and a bottom view of the cartridge;
[0014] FIG. 7 is a cross-sectional view of the cartridge taken along line 7 - 7 of FIG. 3 ;
[0015] FIG. 8 is a cross-sectional view of the cartridge taken along line 8 - 8 of FIG. 4 ;
[0016] FIG. 9 is a cross-sectional view of the cartridge taken along line 9 - 9 of FIG. 6 ;
[0017] FIG. 10 is a cross-sectional enlarged view of the cartridge taken along cutaway line 10 of FIG. 7 ;
[0018] FIGS. 11 and 12 are perspective views of the bottom portion of the cartridge viewed respectively from its top and bottom;
[0019] FIG. 13 is a side view of the cartridge bottom portion;
[0020] FIG. 14 is a cross-sectional view of the bottom portion taken along line 14 - 14 of FIG. 13 ;
[0021] FIG. 15 is a cross-sectional enlarged view of the cartridge top portion taken along cutaway line 15 of FIG. 14 ;
[0022] FIG. 16 is a cross-sectional enlarged view of the cartridge taken along cutaway line 16 of FIG. 7 ;
[0023] FIG. 17 a cross-sectional enlarged view of the cartridge taken along cutaway line 17 of FIG. 9 ;
[0024] FIG. 18 is a perspective enlarged view of the cartridge taken from its top side with a portion cutaway to expose its inner structure;
[0025] FIGS. 19 and 20 are perspective views of the top portion of the cartridge taken respectively from its top and bottom;
[0026] FIGS. 21-23 respectively are top, side and bottom views of the cartridge top portion;
[0027] FIG. 24 is a cross-sectional view of the cartridge top portion taken along line 24 - 24 of FIG. 21 ;
[0028] FIG. 25 is a cross-sectional view of the cartridge top portion taken along line 25 - 25 of FIG. 22 ;
[0029] FIG. 26 is a cross-sectional view of the cartridge top portion taken along line 26 - 26 of FIG. 23 ;
[0030] FIG. 27 is a cross-sectional enlarged view of the cartridge top portion taken along cutaway line 27 of FIG. 24 ;
[0031] FIG. 28 is a perspective view of the baffle, in the interior of the cartridge, viewed towards its top surface;
[0032] FIG. 29 is a perspective view of the baffle viewed towards its lower surface;
[0033] FIGS. 30-32 respectively are a top view and two side views, taken orthogonally with respect to one another, of the baffle;
[0034] FIG. 33 is a cross-sectional view of the baffle taken along line 33 - 33 of FIG. 30 ;
[0035] FIG. 34 is a cross-sectional view of the baffle taken along line 34 - 34 of FIG. 30 ;
[0036] FIG. 35 is a cross-sectional enlarged view of the baffle taken along cutaway line 35 of FIG. 33 ;
[0037] FIG. 36 is a cross-sectional view of a cartridge, such as depicted in FIG. 1 et seq., with a first embodiment of a urine diverter secured to its top wall;
[0038] FIG. 37 is a side view of the diverter illustrated in FIG. 36 ;
[0039] FIG. 38 is an enlarged view of a spacing standoff taken along cutaway line 38 of FIG. 37 ;
[0040] FIG. 39 is a perspective view of the diverter shown in FIG. 36 viewing its underside;
[0041] FIG. 40 is a side view of a second embodiment of a diverter which is useful as an alternate to that depicted in FIG. 36 ;
[0042] FIG. 41 is a top view of the diverter shown in FIG. 40 ;
[0043] FIG. 42 is a cross-sectional view of the diverter taken along line 42 - 42 of FIG. 41 ;
[0044] FIG. 43 is an enlarged view of a spacing standoff taken along cutaway line 43 of FIG. 40 ; and
[0045] FIG. 44 is a perspective of the cartridge, such as depicted in FIG. 36 , placed in a urinal housing for coupling of the cartridge to a drain pipe.
DETAILED DESCRIPTION
[0046] Accordingly, referring to FIGS. 1-27 , a cartridge assembly 100 , acting as a flow trap for urine or other generally fluid waste products, comprises a top portion 102 ( FIGS. 19-27 ) and a bottom portion 104 ( FIGS. 11-15 ). A fluid 103 with urine therein and an oily sealant 105 atop the fluid is contained within the cartridge, as illustrated in FIGS. 7 and 9 .
[0047] Top portion 102 has a cylindrical configuration defined by a tubular wall 106 terminated by an opening 108 at its lower end and a top wall 110 at its upper end. The top wall is sloped downwardly to a flat, generally horizontal flat center portion 112 in which an entry opening 114 is disposed, to act as a urine inlet. As depicted in FIG. 5 , opening 114 comprises a tripartite arrangement of three arced slots 114 a , 114 b and 114 c . A hole 115 is centrally positioned within center portion 112 . As will be described with respect to FIGS. 36-43 , slots 114 a , 114 b and 114 c and hole 115 are adapted to hold either of the two diverters to cartridge 100 . Top portion 102 is further provided with three keys 116 of which one may be of different length than the other two (e.g., see FIG. 2 ) for purposes of properly placing and orienting cartridge 100 within a urinal, as more fully described in U.S. Pat. No. 6,644,339 (the parent application of above-noted Ser. No. 10/647,603).
[0048] Top wall 110 is provided with a recess 117 as shown in FIGS. 7 , 9 , 24 , 26 and 44 at its outer periphery to accept a seal, such as O-ring seal 228 (see FIG. 44 ). Recess 117 has a small dimension sufficient to minimize the trapping of urine therein.
[0049] Top wall 110 of top portion 102 is further provided with three openings 118 which act as air vents that communicate with the interior of cartridge 100 . In the event that one of the openings becomes clogged, such as by urine when the urinal is in use, there will be at least one that remains open. Openings 118 also provide a means by which a tool may be inserted therein for the purpose of inserting and removing the cartridge into and from a urinal, as also described in above-noted co-pending provisional application No. 60/535,463, now patent application Ser. 11/032,508. Accordingly, for purposes of their use as tool engagement means, it is preferred that the outermost two openings be approximately diagonally opposed to one another. However, the placement or use of these openings may be otherwise designed to accommodate other tool configurations.
[0050] The interior of top portion 102 is divided by a bowed vertical separator 120 (e.g., see FIGS. 2 , 8 and 18 ) into two compartments, respectively an inlet compartment 122 and an outlet compartment 124 (e.g., FIG. 8 ). Vertical separator 120 is secured or molded to the interior surface of tubular wall 106 and to the underside of top wall 110 at a terminus 121 a (e.g., see FIG. 9 ) in any convenient manner. The bottom end of the vertical separator terminates in an end or terminus 121 b (e.g., FIG. 2 ) which is disposed to be connected to a baffle 150 which, in turn, will be presently described fully in FIGS. 28-35 . When top and bottom portions 102 and 104 are placed together and a discharge section 128 ( FIGS. 7 , 8 and 11 - 14 ) of bottom portion 104 extends into outlet compartment 124 , inlet compartment 122 and outlet compartment 124 have generally equal volumes. It is important that the compartment volumes be made as equal as possible to ensure that the pressures on both sides of vertical separator 120 remain equal during use of the cartridge. Such pressure equality helps to minimize syphoning or, alternatively, to maximize resistance to syphoning between the compartments and, of particular importance, of sealant 105 from the inlet compartment to the outlet compartment. Thus, the usable life of the cartridge is improved by avoiding premature failure thereof. Additionally, any impediment to liquid flow in minimized.
[0051] Vertical separator 120 is bowed, e.g., curved or bent, to accommodate centrally positioned entry opening 114 which needs to fully communicate with inlet compartment 122 . The illustrated curved bowing of the vertical separator further enables air vent openings 118 also to communicate with the inlet compartment, as best seen in FIGS. 23 and 25 . It is to be understood, however, that the vertical separator need not be curved as illustrated; it may take any configuration that will effect its purpose, that is, to provide equally volumed compartments and to oblige the communications of openings 114 with the inlet compartment. Therefore, for example, if the air vent openings were not used as a means to cooperate with a cartridge inserting and removing tool, as above described, and/or entry opening 114 were not centrally positioned in top wall 110 , or for any other reason apart from its compartment volume-defining purpose, vertical separator 120 may be otherwise configured.
[0052] Bottom portion 104 , as depicted in FIGS. 11-15 , comprises a pan 126 and discharge section 128 extending upwardly therefrom. The upper surface of pan 126 defines a bottom wall 127 of cartridge 100 ; bottom wall 127 may be likened as being the mate to top wall 110 . The pan includes a side wall 130 terminating at an edge 132 ( FIGS. 14 and 15 ) which provides a tongue-in-groove engagement with tubular wall 106 at its lower end opening 108 , as best seen in FIGS. 16 and 17 to provide a fluid-tight engagement between top and bottom portions 102 and 104 . The inner surfaces of pan 126 are rounded to prevent sharp-angled corners and are smoothed to enhance fluid flow and to discourage build up of matter and bacteria or other debris.
[0053] Upwardly extending discharge section 128 , which as described above extends into outlet compartment 124 of top portion 102 , includes a tube 134 (as best seen in FIGS. 11 and 14 ) that communicates with outlet compartment 104 and opens at an exit port area 136 ( FIGS. 2 , 12 and 14 ) through pan 126 for discharge of fluids, e.g., fluid 103 , and other undesired matter from the outlet compartment to a drain 220 ( FIG. 44 ). The discharge section also includes a pair of tubular chambers 138 (e.g., FIGS. 8 , 12 , 14 and 44 ) for receipt of post-treatment chemicals for treating the exiting urine, as contained in control stick 224 or pellets, as more fully described in copending application Ser. No. 11/032,508 (provisional application No. 60/579,921). Chambers 138 are closed at wall 140 (see FIGS. 11 and 14 ) at one of their ends at the uppermost part of upwardly extending discharge section 128 to prevent flow of fluids thereinto from the outlet compartment, and are open at their other ends 142 (see FIG. 14 ).
[0054] As shown in FIGS. 7 , 14 , 16 and 44 , a flow director 144 in tube 134 adjacent exit port area 136 comprises an angled part which is adapted to direct fluid flow towards ends 142 of tubular chambers 138 for impacting control stick 224 , as presently described. A pair of longitudinally extending ribs 145 (see FIGS. 11 and 14 ) are formed in and extend along the length of conduit 134 and terminate adjacent to tubular chamber ends 142 and act further as flow directors also to direct fluid flow towards ends 142 .
[0055] As shown in FIGS. 7 , 14 , 16 and 44 , a key 146 and a keyway 148 are provided respectively on the interior surface of tubular wall 106 (see FIGS. 8 , 20 , 23 , 25 and 26 ) and on the backside of upwardly extending discharge section 128 (see FIGS. 8 and 11 - 14 ). The key and keyway are disposed to provide an orientation and proper alignment between top and bottom portions 102 and 104 and, through the orienting mechanism of keys 116 with the urinal, to place exit port area 136 adjacent exterior drain 220 from cartridge 100 .
[0056] As depicted in FIGS. 2 , 7 - 10 , 12 , 17 and 18 and, more in detail in FIGS. 28-35 , a baffle 150 is disposed to be secured to curved vertical separator 120 ( FIGS. 2 , 7 and 10 ) and acts as a mechanism for improved direction and flow of wastewater fluids through the cartridge in a region from inlet compartment 122 to outlet compartment 124 . The baffle comprises a curved base 152 from which a center wall 154 and side walls 156 a and 156 b upwardly extend. Wall 154 , which terminates in a groove 158 at its upper edge, has the same curvature as that of curved vertical separator 120 so that groove 158 will mate with and fit securely within vertical separator end 121 b , such as illustrated in FIGS. 10 and 17 . Walls 156 a and 156 b are curved similarly as or otherwise contoured in conformance with the inner wall of tubular wall 106 , and the top and bottom walls may be accordingly shaped differently from that as shown and as dictated by wall 106 . Further, the dimension of baffle 150 between walls 156 a and 156 b is sized to form a snug, fluid-tight fit of the baffle within tubular wall 106 , also as shown in FIGS. 8 and 17 . Therefore, fluids within inlet compartment 122 are forced to flow onto the surface of curved base 152 .
[0057] With respect to the curvature of base 152 , which acts as a weir, the base is carefully configured to effect several desired results. The curved base has a lowermost segment 160 , which is slightly lower at its center part or point 160 a than at its adjacent side parts or points 160 b . Base 152 curves generally at 90° from generally upstanding wall 154 , and all parts 160 a and 160 b rise to an undulated termination or terminal edge 162 . Termination 162 has a center part 162 a which is slightly elevated from its neighboring side parts 162 b . This curved configuration of the baffle directs fluid 103 (e.g., as shown in FIGS. 7 and 9 ) to flow in the directions generally portrayed by arrow-headed lines 164 , that is, from center part 160 a to side parts 162 b and thence under the baffle, between its underside 166 and the upper surface of bottom portion pan 126 . The fluids then exit into outlet compartment 124 as portrayed generally by arrow-headed lines 168 , as depicted in FIG. 30 . The directed flow paths, as represented by arrow-headed lines 164 and 168 provide a constriction that increases the flow velocity and avoids the resistance of flow due to deposits on bottom portion 104 generally within the region from inlet compartment 122 to outlet compartment 124 . The increased velocity thus effects channels of least resistance through any solid matter deposited in the region between the inlet and outlet compartment and at least minimizes any deposit of such solid matter. The above-described components or parts of baffle 150 may therefore be defined as channeling media.
[0058] Reference is now made to FIGS. 36-43 , and to a urine diverter whose two illustrative embodiments are shown as diverters 170 and 270 . For the first embodiment shown in FIGS. 36-39 , a pretreatment control tablet 172 is held within a tablet retainer mechanism 174 for holding the tablet within the diverter. Diverter 170 , as generally depicted in FIG. 36 , is positionable atop wall 110 of top portion 102 for protectively covering entry opening 114 (e.g., see also FIG. 5 ) and for providing a circuitous path for flow of urine to the opening. Therefore, urine is prevented from directly contacting and entering into opening 114 and impinging upon sealant 105 within the cartridge. Diverter 170 , which includes a shell 176 , is slightly spaced from top portion top wall 110 to assure a clear path for flow of the urine and to space retainer 174 and tablet 172 from the top wall. Such spacing is effected by use of standoffs 178 (as best shown in FIG. 38 ), which depend from shell 176 and comprises a large portion 178 a and a smaller portion 178 b . Portion 178 b is made to be as small as possible to permit the smallest contact of the diverter with the top wall and, therefore, to provide the largest possible unobstructed flow path.
[0059] As depicted also in FIGS. 37 and 39 , shell 176 comprises an upper surface 180 , terminated by a periphery 182 with a downwardly depending flange 184 . Upper surface 180 slopes downwardly towards periphery 182 to encourage flow of urine towards the periphery. Inwardly-facing bumps 186 are formed on large portion 178 a of standoffs 178 for holding tablet retainer 174 to the inside of shell 176 .
[0060] A tubular housing 188 preferably of cylindrical configuration is secured at one end to the center of the under surface of shell 176 and terminates in a latching mechanism 190 at its second end 192 which has a bi-level shape. The second end is also formed with cutaway portions 194 , as configured by the shape of bi-level end 192 , into legs 196 to permit a bending of the latching mechanism. Latching mechanism 190 comprises pairs of facing teeth 198 at the ends of legs 196 which are adapted to latch into arced slots 114 a , 114 b and 114 c of top wall 110 for securing diverter 170 to top portion 102 .
[0061] Tablet retainer 174 is more fully disclosed in provisional application No. 60/535,463 and its non-provisional application Ser. No. 11/032,508, filed on 9 Jan. 2005 whose contents are incorporated herein as if set forth in haec verba.
[0062] A pair of post-treatment discharge control sticks 224 or pellets are disposed to be placed within tubular chambers 138 and may include a biocide and cleaning agents held in a time-release binder. Its use is primarily as a descaling agent to help maintain a clean drain pipe, and especially in environments where the cartridge use pattern is such that additional descaling is needed. The post-treatment discharge control sticks or pellets may be used alone or in conjunction with pretreatment control tablet 172 . Like tablet retainer 174 , the post-treatment discharge control stick or pellets is more fully disclosed in provisional application No. 60/535,463 and its non-provisional application Ser. No. 11/032,508, filed on 9 Jan. 2005 whose contents are incorporated herein as if set forth in haec verba.
[0063] The second embodiment of the diverter, diverter 270 , is shown in FIGS. 40-43 . This diverter is positionable atop wall 110 of top portion 102 and protectively covers entry opening 114 (e.g., see also FIG. 5 ) in a manner similar to that shown for diverter 170 in FIG. 36 , and provides a circuitous path for flow of urine to the opening. Therefore, urine is prevented from directly contacting and entering into opening 114 and impinging upon and agitating sealant 105 within the cartridge. In addition, a pretreatment control tablet may be held within a tablet retainer for holding the tablet within the diverter, again as described above. Diverter 270 , which includes a shell 276 , is slightly spaced from top portion top wall 110 to assure a clear path for flow of the urine and to space the retainer and its retained tablet from the top wall. Such spacing is effected by use of standoffs 278 (as best shown in FIG. 43 ), which depend from shell 276 and comprises a large portion 278 a and a smaller portion 278 b . Portion 278 b is made to be as small as possible to permit the smallest contact of the diverter with the top wall and, therefore, to provide the largest possible unobstructed flow path.
[0064] As depicted also in FIGS. 40-42 , shell 276 comprises an upper surface 280 , terminated by a periphery 282 with a downwardly depending flange 284 . Upper surface 280 slopes downwardly towards periphery 282 to encourage flow of urine towards the periphery. Inwardly-facing bumps 286 , which are more elongated than previously described bumps 186 , are formed on large portion 278 a of standoffs 278 , as well as on other inner parts of flange 284 , for holding the tablet retainer, such as previously described retainer 174 , to the inside of shell 276 .
[0065] A base 288 , preferably of cylindrical configuration, is secured at one end to the center of the under surface of shell 276 and terminates in a fastener 290 at its second end 292 . The fastener is formed as a post 296 terminating in a beveled end 298 . Fastener 290 is sized to form an interference fit within hole 115 of top wall 110 for securing diverter 270 to top portion 102 .
[0066] When all the above-described components are assembled together, they form cartridge 100 as depicted, for example, in FIGS. 1 and 36 . This assembled cartridge is then adapted to be placed within a urinal 226 ( FIG. 44 ) which, in turn, is coupled to drain 220 with exit port area 136 as provided through the orienting mechanism of keys 116 . An O-ring seal 228 is sealingly placed within recess 117 in the periphery of top wall 110 .
[0067] While separator 120 , baffle 150 and other components are described as providing a preferred cooperative arrangement, it is to be understood that these individual components may be employed separately should the user so choose.
[0068] Accordingly, although the invention has been described with respect to particular embodiments thereof, it should be realized that various changes and modifications may be made therein without departing from the spirit and scope of the invention.
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In a urine cartridge or wastewater trap, equalized pressures and increased flow rate between its inlet and outlet compartments increases the life of the cartridge. The pressure equalizing is effected by placement of a separator between the two compartments to provide them with substantially equal volumes. The increased flow rate is created by a uniquely configured baffle positioned adjacent a pan at the bottom of the cartridge. The baffle configuration is shaped to provide a constriction that increases the flow velocity of the urine so that the fluid flow effects a channel along the bottom pan and through any solids deposited on the bottom pan. A diverter may be placed above the centrally located entry to the inlet compartment to create a circuitous path for preventing a disturbing impingement of the urine onto the sealant contained in the inlet compartment. To accommodate the centrally placed entry and its placement vis-a-vis the inlet compartment, the separator is bowed at its location adjacent the entry and towards the outlet compartment. To fit the configuration of the baffle, the separator is curved generally in a likewise manner.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a division of copending application Ser. No. 10/872,118, filed Jun. 17, 2004, which claims the benefit of U.S. provisional patent application No. 60/480,143, filed Jun. 19, 2003, under 35 U.S.C. §119(e).
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to methods of making porous polymeric membranes, in particular hydrophobic membranes, and to products of such methods. In an important aspect, it is directed to membrane-producing methods incorporating control of physical properties such as pore dimension, density, and pre-stress characteristics (including flexibility) of a membrane using highly hydrophobic plastics as the porous layer to create a waterproof and highly breathable fabric, as well as to fabrics thereby produced.
[0004] Highly breathable and waterproof fabric currently is based on a “Teflon”® polymer membrane as the hydrophobic layer as in “Gore-Tex”® fabrics, or on other materials such as polyurethane. “Teflon”® polymer is the most hydrophobic material available but no solvent can dissolve it so the porous membrane structure is made by physically stretching a thin “Teflon”® sheet several times while heated, forming a fibrous structure, and then overlaying several such sheets to create a porous membrane. Other methods of creating the porous membrane out of “Teflon”® sheets can provide control of maximum pore diameter and density but are not as breathable as the “Gore-Tex”® membrane. The cost of making the “Gore-Tex”® type membrane is very high.
[0005] Other materials such as polyurethane can use a solvent-based knife spreading and baking process. Polyvinylidene fluoride (PVDF) is the next best hydrophobic material after “Teflon”® polymer and it does have a limited number of solvents. This means that a traditional solvent/non-solvent process as described by Michaels (U.S. Pat. Nos. 3,615,024 and 6,112,908) can be used to make the membrane. There are many parameters relevant to this being explored in industrial laboratories. The non-solvent has to be highly miscible with the solvent to reduce the leaching time. Alcohol based non-solvents are very popular among membrane makers. Water can be used at elevated temperature to increase its miscibility with solvents and thus reduces gelation time.
[0006] Heretofore, however, no attention has been paid to stress relief of the porous membrane. During its production, the PVDF membrane is stressed and becomes brittle and therefore likely to break after many folding actions, thus disqualifying it as a suitable hydrophobic layer for a fabric. Other materials do not have comparable hydrophobic characteristics. PVDF has a very low surface tension, only slightly more than “Teflon”® polymer. “Teflon”® polymer has a surface tension of 18 dynes/cm and PVDF 25 dynes/cm. These materials are far superior to any other material (for example: polyurethane). A PVDF membrane can be constructed to have a vacuole pocket structure underneath a thin top layer, which gives it an extended surface area for water vapor passage, making it potentially more breathable than the Gore membrane without having to have larger pore sizes on the skin layer. Smaller pores improve waterproofness. None of the prior art discloses a method of controlling the texture of the membrane which is usually hard and brittle and therefore unsuitable for use as the hydrophobic layer of a breathable and water proof fabric.
[0007] 2. Description of Prior Art
[0008] All porous membranes manufactured using the solvent/non-solvent process follow in large part the teaching of U.S. Pat. No. 3,615,024 (Michaels '024), which describes (see FIG. 1 of the patent) the relationship of solvent and non-solvent with solids and the process to follow for the gelation of a porous membrane. However, the patent does not mention that there is a pre-stress problem during the gelation step, which influences the pore structure and the flexibility of the membrane. At the time of Michaels '024 a porous membrane with a thin skin using cellulose acetate and cellulose nitrate for reverse osmosis already existed. The reverse osmosis membrane of that time was stiff and breakable when dry and soft and elastic when wet, and could absorb large quantities of water. In particular, Michaels '024 was concerned with low temperature thermal distillation of seawater. There was no need to address the pre-stress relief of the hydrophobic membrane.
[0009] U.S. Pat. Nos. 3,240,683 and 3,406,096 (Rodgers) are directed to thermal distillation using a hydrophobic membrane. These Rodgers patents specify that the pore diameter should be in the range of 1.0 to 2.0 micron, but do not teach how to make the membrane. They mention that the pore diameter if too small would impede the vapor flow throughput and if too large the hydrostatic pressure on the membrane surface would force water through. No mention is made of stress relief of the membrane during the gelation process.
[0010] As set forth in U.S. Pat. No. 4,265,713 (Cheng) and Nos. 4,419,242, 4,316,772 and 4,419,187 (Cheng et al.), the present applicant discovered that the hydrophobic membrane should be covered by a thin hydrophilic layer which prevents seawater penetration into the hydrophobic pores. The hydrophilic layer covering the opening of pores also prevents contamination by oils and other wettable agents which would cause the hydrophobic pores to be penetrated by liquids. No mention of membrane pre-stress relief is made in these prior patents.
[0011] U.S. Pat. No. 6,112,908 (Michaels '908) refers to the composite layer structure of the aforesaid U.S. Pat. Nos. 4,419,242 and 4,419,187. The numerous references of record in Michaels '908 deal with the composite membrane structure for thermal distillation of salt water.
[0012] U.S. Pat. Nos. 3,962,153 and 4,187,390 (Gore) relate to stretched “Teflon”® (tetrafluoroethylene polymer) porous membranes, with which a hydrophilic layer may be employed, using a Hyper-A glue layer as the hydrophilic material.
[0013] U.S. Pat. No. 6,146,747 (Wang et al.) for liquid filtering uses PVDF membrane as a substrate. This is because PVDF can prevent a large number of chemicals from attacking the material or dissolving it. However, owing to the hydrophobic property of PVDF, the filter needs a wetting agent such as alcohol to penetrate the pores first and this is then followed by the liquid that is being filtered. This restricted the application of the PVDF as a micro filter. The Wang et al. patent describes adding a small quantity (less than 2%) of hydrophilic polymer such as PVP to the PVDF solution with DMAC as solvent, then going through the solvent/non-solvent gelation process of Michaels, to obtain a PVDF based membrane with a hydrophilic property without using a wetting agent to initiate liquid filtration. No mention is made of porous membrane stress relief.
[0014] U.S. Pat. No. 6,126,826 (Pacheco et al.) describes a control process for making membranes using a solvent and a small amount of co-solvent, which is then replaced with a solvent/non-solvent mixture. The patent states that the pore size of the membrane can be controlled by the temperature of the solution, and also that the pore structure is simpler, which means that the pressure drop would be smaller for the same fluid flow rate. Again, there is no mention of pre-stress relief in the described process and product. The patent states further that a low-pressure drop is irrelevant to thermal vapor throughput in that the pressure drop is so small that the flow is not controlled by the pressure differential but by the relative humidity and porous density of the membrane. That is why a thin coating of a hydrophilic material covering all the holes did not change the vapor flow rate significantly.
[0015] U.S. Pat. No. 4,863,788 (George L. Bellairs, Chris E. Nowak and Mahner Parekh) describes a complicated multi-layer membrane. It contains no teaching on control of flexibility and pore size and distribution by adjustment of surface tension of non-solvent bath.
SUMMARY OF THE INVENTION
[0016] Stated broadly, an object of the present invention is to provide new and improved methods for producing porous membranes, in particular hydrophobic membranes, by a solvent/non-solvent process controlled to develop desired membrane properties such as pore characteristics and flexibility.
[0017] Another object is to provide a waterproof fabric including a woven or non-woven backing on a thin porous hydrophobic and preferably PVDF membrane having controlled pore size distribution for waterproofness and high vapor throughput for comfort. An additional object is to provide such a fabric which is soft with good “hand,” achieved by controlled pre-stress relief of the porous structure during its formation
[0018] Further objects are to make a hydrophobic porous membrane that resists water penetration at least to a water pressure equivalent to that of a 60 MPH storm hitting a hat, cloth jacket, shoes, etc., without penetrating the fabric; to make a hydrophobic porous membrane that can pass water vapor under typical human body and ambient temperatures at a rate similar to that of, or better than, “Teflon”® ePTFE membranes with fabric and hydrophilic coating, viz., a membrane that can pass water vapor under such conditions in a range of 4000 g/m 2 /day to 10,000 g/m 2 /day; to provide a hydrophobic porous membrane that is soft enough to provide comfort as a cloth, i.e., characterized by good “hand” as that term is used in the clothing industry; and to provide such a porous membrane made of hydrophobic material second only to “Teflon”® polymer in hydrophobicity.
[0019] Yet another object is to be able to coat such a membrane on a woven or non-woven fabric without the use of a glue layer or minimum requirement for this glue layer.
[0020] Other objects are to provide such a membrane having a very thin hydrophilic layer coated over its pores without impeding the breathability of the material, thereby to improve waterproofness so that the membrane can withstand rain with a wind velocity of 60 to 100 mph; to provide such a membrane wherein the hydrophilic layer is attached to a loose net material to prevent mechanical rubbing of the membrane surface; and to provide such a membrane wherein the pores are 50 to 3000 nanometers in diameter.
[0021] An additional object is to control the softness of the membrane by pre-stressing it during the gelation process of membrane formation. This can be done by selection of different PVDF products as follows: Kynar homopolymer 460, 1000 series, 700 series and 370; Kynar copolymer 2500 series, 2750/2950 series, 2800/2900 series, 2850 series, and 3120 series, Solef1015, Solef 21216, Solef6020, Solef3108, Solef3208,Solef8808, Solef11008, Solef11010, Solef21508, Solef31008, Solef31508, Solef32008, Solef60512, Solef1006, Solef1008, Solef1010, Solef 1012, Solef1015/0078, Solef6008, Solef6010, Solef6012, Hylar 301F, Hylar460/461, Hylar 5000.
[0022] Another object is to provide such a membrane incorporating a small quantity of a fluorine-containing elastomer, e.g., “Viton”® fluoroelastomer, as an additive (not as a plasticizer) or such materials as long chain di-carboxylic acid esters with a “springy” structure, such as Dibutyl sebacate, Dioctyl adipate and others, in PVDF material for additional elasticity and further softness.
[0023] To these and other ends, the present invention in a first aspect broadly contemplates the provision of a method of producing a porous membrane, comprising providing a solution of a membrane-forming polymer in a solvent therefor, establishing a film of the solution, and bringing a liquid material including a non-solvent for the polymer into contact with the film so as to leach solvent from the solution and cause gelation of the polymer to form the membrane, wherein the improvement comprises controlling stress to which the membrane is subjected during gelation for developing at least one preselected physical property (e.g., softness or a porosity characteristic) in the formed membrane.
[0024] In important particular embodiments, the step of controlling stress comprises subjecting the membrane to compression stress during gelation. Compression stress during gelation (also sometimes referred to herein as compression pre-stress of the membrane) renders the membrane non-brittle, soft and flexible, and also tends to reduce pore size.
[0025] The step of controlling stress during gelation is advantageously performed by controlling surface tension of the liquid material (i.e., the non-solvent) in relation to that of the solution. Thus, the liquid material can be a mixture of at least two liquids and the surface tension of the liquid material can be controlled by selection of relative proportions of the two liquids in the liquid material. When the liquid material has a surface tension greater than that of the solution, the membrane is subjected to compression stress during gelation. The surface tension of the liquid material (non-solvent) may be selected, for a given solvent/non-solvent system, to provide desired softness or flexibility of the produced membrane and at the same time to enable attainment of a pore size sufficient for satisfactory breathability (gas flow through the membrane).
[0026] If the non-solvent surface tension is less than that of the solution, the membrane is subjected to tension stress during gelation (tension pre-stress), rendering the produced membrane brittle, with larger pores than in the case of compression pre-stress. The term “stress relief” is used herein to refer particularly to selection of non-solvent surface tension, in a given solvent/non-solvent system, such as to prevent or reduce tension pre-stress. If the solvent and non-solvent have the same surface tension, however, there is no stress on the membrane during gelation, with the result that channels for gas flow through the membrane fail to connect.
[0027] In the method of the invention, as embodied in the procedures herein described, the polymer forms a hydrophobic membrane, and the solvent and non-solvent are miscible. Very preferably, the polymer is PVDF. The solution may also include a fluorine-containing elastomer in an amount such that the formed membrane contains a minor proportion of the elastomer. The solvent may, for example, be DMAC or DMSO; the non-solvent may comprise a mixture of water and at least one of methanol and ethanol. In the latter case, non-solvent surface tension is increased or decreased, respectively, by increasing or decreasing the proportion of water relative to methanol or ethanol. For instance, the relative proportions of water and methanol or ethanol may be such that the liquid material has a surface tension greater than that of the solvent, thereby subjecting the forming membrane to compression stress during gelation.
[0028] The invention in a specific sense embraces a method of producing a soft, waterproof, breathable fabric, comprising providing a solution of PVDF in a solvent therefor, establishing a film of the solution, and bringing a liquid material including a non-solvent for PVDF into contact with the film so as to leach solvent from the solution and cause gelation of PVDF to form a porous hydrophobic membrane, the solvent and non-solvent being miscible, wherein the liquid material has a surface tension greater than that of the solution, such that the membrane is subjected to compression stress during gelation. In certain advantageous or preferred embodiments, the film is established by coating the solution on a fabric that is slightly soluble in the solvent, thereby fixing the produced membrane on the fabric without use of an adhesive. Further, this method includes the step of applying a thin hydrophilic layer over a surface of the produced hydrophobic membrane. Also, as mentioned above, a fluorine-containing elastomer may be included in the solution such that the produced membrane contains a minor proportion of the elastomer.
[0029] In embodiments of this method, the surface tension of the liquid material is selected, in relation to that of the solution, to provide pore characteristics in the produced membrane such that the membrane resists water droplets at a pressure equivalent to a 60 miles-per-hour wind, and/or to provide pore characteristics in the produced membrane such that the membrane can pass a quantity of water vapor of between 4,000 and 10,000 g/m 2 /day at normal human body and ambient temperatures, and/or to provide a pore size of between 100 and 1000 nm in the produced membrane.
[0030] The invention in further aspects contemplates the provision of a soft, porous hydrophobic membrane comprising a thin outer skin having small pores and a thicker layer beneath said skin having large pores, with a multiplicity of vacuoles formed immediately beneath said skin, produced by the foregoing method; and the provision of a breathable, waterproof fabric comprising a fabric layer having opposed surfaces, the aforesaid hydrophobic membrane fixed to a surface of said fabric layer, and a thin hydrophilic layer coated over the membrane skin. A loose net material may be attached to the hydrophilic layer to prevent mechanical rubbing of the membrane.
[0031] By way of additional explanation of the invention, it may be noted that high water vapor evaporation throughput is the key for a high performance membrane. Traditionally a PVDF membrane is made of a solution containing no more than 20% solid PVDF in a solvent such as DMAC and a non-solvent bath of methanol alcohol. The membrane has generally a thin skin structure as described in Michaels '024 but with large pore diameter on the surface where it first contacts the non-solvent. A labyrinthine porous structure with decreasing average pore diameters lies beneath this skin. Porosity and maximum pore diameter are controlled by the amount of solid in the solution. The resulting membrane works well for a desalting application as a hydrophobic membrane but is very stiff and subject to breakage when folded.
[0032] The discovery leading to the present invention arose from preparation of a PVDF membrane using the same solid concentration with DMAC as solvent but with warmed water as the non-solvent. It was found that under these conditions, the membrane forms a thin skin with vacuoles behind the skin layer, and the membrane structure is sponge-like and under compression stress. No matter how sharply or how often one folds it or rolls it up it remains soft and strong without breakage.
[0033] It is further discovered that due to the vacuoles the flow rate is higher than in commercial membranes such as “Millipore”® membranes with comparable maximum pore diameters.
[0034] However, the process is not straightforward: when using water as non-solvent the compression stress reduces the surface pore diameter to about 0.1 micron and also reduces the number of pores on the thin skin surface so that the vapor flow rate is drastically reduced.
[0035] As patented by the present applicant (U.S. Pat. Nos. 4,419,242; 4,265,713; 4,316,772 and 4,419,187), to prevent contamination of the hydrophobic layer, a thin coat of hydrophilic layer is needed. The thin skin structure provides better texture for coating than the Gore membrane, which has nodes and fibrous structures.
[0036] It is further discovered that if the fabric can be slightly dissolved by the same solvent used for the PVDF then direct knife coating of the solution followed by dipping into the non-solvent bath fixes the membrane to the fabric without having to have a glue layer between fabric and PVDF membrane.
[0037] The following disclosure describes extensive research work covering all the membrane making parameters such as: solid concentration, type of solvent, the control of surface tension with respect to the solid used, the leaching time versus thickness, the bath temperature, the solution temperature, the drying temperature, the baking time, and baking temperature etc. This investigation resulted in establishment of the parameters which provide the smallest pore size at highest vapor flow rate and yet a form a membrane which is soft enough to provide the “hand” for fabric consumers.
[0038] It was also discovered that using a fluorine containing elastomer such as “Viton”® fluoroelastomer provides PVDF with additional elasticity. “Viton”® fluoroelastomer is soluble in the same solvent as used for PVDF and forms a porous structure together with the PVDF without being precipitated out as aggregated small lumps.
[0039] Further features and advantages of the invention will be apparent from the detailed description hereinafter set forth, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 is a cross sectional view of an illustrative embodiment of the waterproof and breathable fabric of the present invention;
[0041] FIG. 2 is a diagrammatic illustration of the measurement of softness;
[0042] FIG. 3 is a diagrammatic illustration of the measurement of hydrophobic and hydrophilic characteristics of liquid on a solid surface;
[0043] FIGS. 4 ( a ) and ( b ) are, respectively, Scanning Electron Microscope (SEM) pictures of an example of a PVDF membrane of the present invention and a Gore “Teflon”® ePTFE membrane;
[0044] FIGS. 5 ( a ), ( b ) and ( c ) are SEM pictures of PVDF membrane with 15% solid concentration with DMAC as solvent, water as non-solvent: ( a ) the solid surface side of the membrane, ( b ) cross section and ( c ) surface layer;
[0045] FIGS. 6 ( a ), ( b ) and ( c ) are SEM pictures of PVDF membrane with 15% solid in DMAC solvent, with 60% water and 40% methanol as non-solvent: ( a ) the solid surface side of the membrane, ( b ) cross section and ( c ) surface layer;
[0046] FIGS. 7 ( a ), ( b ) and ( c ) are SEM pictures of PVDF membrane with 15% solid in DMAC solvent, with 0% water and 100% methanol as non-solvent: ( a ) surface layer, ( b ) cross section and ( c ) the solid surface side of the membrane;
[0047] FIG. 8 is a diagrammatic illustration of non-solvent surface tension forces interacting with solute during solidification (solvent with solid dissolved homogeneously);
[0048] FIG. 9 ( a ) is a phase diagram for the gelation process of the Michael '024 solvent/non-solvent method for making a porous membrane, showing the solvent, non-solvent and polymer interactions;
[0049] FIG. 9 ( b ) is a phase diagram of the gelation process described in the present application showing, in addition to the interactions of FIG. 9 ( a ), mutual interaction surface tension and pre-stress control;
[0050] FIG. 10 is a graphical compilation of data on the factors that control the surface tension of the mixture and its effect on maximum pore diameter and porosity (as measured by N 2 flow rate at a given pressure difference);
[0051] FIG. 11 is a graph showing the effect of non-solvent bath temperature on membrane maximum pore size and porosity;
[0052] FIG. 12 is a photomicrograph illustrating the composite structure of a PVDF membrane coated with PVA as a hydrophilic coating;
[0053] FIG. 13 is a photomicrograph showing vacuoles as a means of extending membrane surface area;
[0054] FIG. 14 is a graph showing the effect on pore size of static soaking time in non-solvent bath;
[0055] FIGS. 15 ( a ), ( b ) and ( c ) and FIG. 16 are graphs showing variation of maximum pore size (as measured by N 2 flow rate) on first surface with non-solvent surface tension, which is controlled by changing the proportion of water and methanol from 100% water (high surface. tension) to 100% methanol (low surface tension); and
[0056] FIG. 17 is a highly simplified schematic view of a typical design of a fabric coating machine using mass transfer technology to set up a convective non-solvent bath such that there is a gradient of concentration of the solvent, wherein the solvent content is high at the entrance of the non-solvent bath and is low (or there is no solvent) at the exit end of the non-solvent bath.
DETAILED DESCRIPTION
[0057] Description of Drawings
[0058] FIG. 1 illustrates the structure of an embodiment of the waterproof and breathable fabric of the present invention, including a fabric outer layer, a hydrophobic water vapor transmission layer, small pore surface structures on both sides to prevent water penetration, and a hydrophilic coating to which may be attached a net protection layer (not shown) to prevent mechanical rubbing. The outer layer fabric can be a woven or non-woven structure and may have a coating to prevent wetting. Under the thin porous layer are large vacuoles that improve vapor transmission.
[0059] FIG. 2 illustrates a means of measuring the softness of fabrics. The softness is measured as the fabric's natural droop angle. A stiff membrane will stick out and very soft membrane will droop 90° downward. Most membranes droop at an angle between the two extremes. Therefore the angle of droop gives a comparison of relative softness.
[0060] FIG. 3 is a diagram in explanation of the measurement of liquid-solid interaction. On the left is a hydrophilic solid and on the right is a hydrophobic solid. The contact angle is θ. If cosine (θ) is positive the surface is hydrophobic and if cosine (θ) is negative then the surface is hydrophilic. The surface tensions can be calculated according to Young's formula:
γ (b,s) −γ (a,s) =γ (b,a) ·cosine(θ)
wherein γ (b,s) is the surface tension of fluid (liquid or gas) with solid, γ (a,s) is the surface tension of solid with air, γ (b,a) is the surface tension of fluid with air, and θ is the contact angle.
[0061] FIG. 4 compares a Scanning Electron Microscope picture of (a) the PVDF layer of an example of the fabric of the present invention with (b) the Gore “Teflon”® membrane used in “Gore-Tex”® fabric. The Gore membrane has a structure of fibers radiating from nodes, with several layers overlaid to obtain sub-micron average hole sizes. The typical holes are narrow and long lying between adjacent fibers. Assuming no displacement of fibers because of liquid pressure, the average pore diameter may be calculated on a hydraulic diameter basis. On the other hand the pores on the PVDF membrane are round and its hydraulic diameter is the actual diameter of the holes.
[0062] A droplet traveling at 60 miles per hour and striking a “Teflon”® membrane requires a pore diameter of 0.35 micron to penetrate. For PVDF the diameter is 0.31 micron. The surface tension unit is in dyne/cm.
[0063] FIG. 5 shows SEM pictures of examples of PVDF membranes produced by a solvent/non-solvent technique when water is used as the non-solvent and the solvent is DMAC: (a) the surface in contact with a metal support on which the membrane was cast, (b) the interior structure of the porous media and (c) the surface first in contact with the non-solvent.
[0064] Water has a very high surface tension (75 dynes/cm), so the phase inversion process causes the material to form under compression. Mercury has the highest surface tension of all but mercury cannot co-mix with DMAC to pull solvent out of the solute. In (b), the cross section of the porous membrane, a strong thin skin layer can be seen. The contact with the non-solvent bath pulled solids to the surface and left behind a vacuolar structure which became solidified later in time. This vacuolar structure improves softness and vapor transmission but is not desirable for filter applications. In (a) the slow degradation of the diffusion process of solvent into non-solvent produces larger surface pore diameters and no thin skin layer. Good waterproofness depends on the small pore diameters of the porous interior.
[0065] The porous structure was solidified under compression so bending of the membrane essentially releases the pre-compression stress, which is why the membrane is soft. Since during the bending action no surface has been subjected to tension, the membrane is also tough and can be flexed repeatedly without breakage.
[0066] FIG. 6 shows a series of SEM pictures using 60% water and 40% methanol mixture as the non-solvent bath: (a) the so-called “matte” surface last to interact with the non-solvent, (b) the porous cross section, and (c) the surface first in contact with the non-solvent mixture. Methanol has the lowest surface tension (18 dynes/cm) besides ether (17 dynes/cm) but ether has very high vapor pressure at room temperature therefore the final amount of ether in the mixture can not be known precisely. With methanol as the low surface tension liquid and water as the high surface tension liquid, varying the concentration ratio provides a way of controlling the non-solvent surface tension. This allows pre-stressing of the membrane during solidification from compression all the way to tension.
[0067] FIG. 7 shows the SEM pictures of a membrane in which the DMAC solution has been subjected to pure methanol alcohol: (a) the matte surface, (b) the porous structure, and (c) the surface first in contact with the non-solvent. There is no thin skin layer and the pores are relatively large. The membrane porous structure is subject to tension, so bending it adds tensile stress to the surface and it breaks. This membrane is as stiff as cardboard because of tension on the surface. This membrane is useful in filtration applications but is not suitable for fabric applications.
[0068] FIG. 8 illustrates the differences between hydrophobic and hydrophilic non-solvent interactions with solute. Normally the droplets that form on a solid surface manifest the hydrophobic interaction of a liquid with a solid surface. If the contact angle between the liquid and the solid is smaller than 90 degrees the surface interaction is hydrophobic; if it is greater than 90 degrees it is hydrophilic. It is commonly described in textbooks in terms of a capillary tube inserted into the liquid. If the liquid rises up the tube it is hydrophilic ( FIG. 8 a ). If the liquid is pushed down then the tube material is hydrophobic ( FIG. 8 c ). The contact angle and the height or depth that the liquid rises or sinks to in the tube gives a precise measure of the interactive surface tension between the liquid and tube material.
[0069] FIGS. 8 a and 8 c illustrate one of the ways of measuring the surface tension of liquid with a solid capillary tube. A hydrophilic interaction pulls a column of liquid up into the capillary tube and a hydrophobic interaction pushes the liquid down. The contact angle θ and the differential in liquid level h enable the surface tension to be calculated. The total weight of the column of liquid is ρghπr 2 . The balance force due to interacting surface tension is equal to γ (b,s) πd cosine(θ). Hence measuring h and θ with a known value of d gives γ (b,s) .
[0070] When a solid material is dissolved in a solution which is in turn in contact with a non-solvent, and also if the non-solvent can absorb the solvent without limitation, then the solid will be precipitated from the solvent. The force of rejection between the solid and the non-solvent comes from the hydrophobic reaction between them and acts to compress the solids during gelation. Thus there is compression pre-stress ,on the resulting solid porous structure ( FIG. 8 d ). On the other hand, if the non-solvent is hydrophilic and subject to a force of attraction between the precipitated solid surface and the non-solvent then the solid is pulled away from the solute and the porous structure is subjected to a tension force ( FIG. 8 b ).
[0071] Thus changing the surface tension of the non-solvent will affect the porous structure of the membrane. It was found as illustrated here that a pure water bath having the highest surface tension against PVDF produces a compression structure and a thin skin and vacuoles. The maximum pore size in the skin layer is very small even though the porosity is dense. The average pore size is also small which gives low vapor transmission (measured as N 2 flow at a given pressure differential). Such a material may have filter applications but is not suitable as a highly breathable membrane for clothing. The structure is shown in FIG. 5 . At the other extreme, when the non-solvent bath is pure methanol, the membrane structure is subjected to tension. No thin skin is formed. The pore size on the surface is very large and the porous structure is highly permeable to vapor. One problem is that the membrane is at maximum tension so a slight folding of it would over-stress its surface and cause breakage. Another problem is that the pore size is too large to be an effective barrier to water droplets. The large pores are also difficult to cover with a hydrophilic layer. FIG. 6 illustrates an intermediate case in which a controlled non-solvent surface tension yields a maximum pore size of less than 0.3 micron but is still highly porous: the permeation rate as measured by N 2 flow is about 55 to 60% that of material produced in the pure methanol bath but has similar pore size to that produced in the pure water bath (but with many more pores on the surface), giving a N 2 flow rate many times greater than that of the pure water bath membrane. Thus is exemplified the feature, in the present invention, of a “controlled surface tension non-solvent bath” in which PVDF solids are precipitated to form a membrane with good flow rate and a pore size of no greater than 300 nanometer, and soft enough to give a good “hand” for fabric applications.
[0072] FIG. 9 ( a ) is the classical phase diagram from Michaels '024 for the solvent/non-solvent gelation process for a porous membrane. The process starts with a polymer solvent solution at point A. When this is then dipped into a non-solvent the process follows a path (the details of which depend on the rate of diffusion and the properties of the non-solvent) indicated by the line A-B. At B the mixture reaches a boundary where it becomes two-phase (liquid and gel) and becomes a porous structure. The gel part of the mixture then moves from B to D at which point the polymer can no longer be dissolved into the solvent as the limit of a concentration has been reached. The liquid phase moves from B to G.
[0073] FIG. 9 ( b ) illustrates the complete relationship of the solvent/non-solvent process as a 3-dimensional phase diagram. The surface tension of non-solvent with respect to the solution of solvent and polymer affects the porous structure. Basically, it uses Michaels' diagram as the equilibrium plane, and this is tilted upwards if the surface tension of the non-solvent is less than the solute surface tension: the pore sizes will be larger and the membrane is under tension and becomes hard and stiff. On the other hand if the non-solvent surface tension is greater than the solution surface tension, Michaels' triangle is projected downward, the membrane is under compression so the pores are in general smaller and the material is softer.
[0074] FIG. 10 is a compilation of data created by varying the solid concentration in DMAC, the solute temperature, water temperature, and the mixture of water and methanol from pure methanol to pure water. Maximum pore size and N 2 flow rate are measured at a constant pressure differential of 15 psid. Depending on the need the membrane can be highly waterproof and soft or have a high N 2 flow rate and be less waterproof and stiff. The compiled data is used as an illustration only.
[0075] In the following Tables, Table I gives a list of solvents that can be used to dissolve PVDF. Table II is an example of non-solvents with their surface tensions. These can be used as non-solvents for the PVDF but yet dissolve well in the solvents.
TABLE I List of solvents that can be used to dissolve PVDF Solvent Surface tension DMAC(N,N,Dimethylacetamide) 32.43 at 30 deg C. MEK(2-Butanone; Ethyl methyl ketone) 24.6 at 20 deg C. DMF(N,N,Dimethylformamide) 36.76 at 20 deg C. THF(Tetrahydrofuran) 26.4 at 20 deg C. NMP(1-methyl-2-pyrrodidone; M-pyrol) Trimethyl phosphate Tetramethylurea
[0076]
TABLE II
List of non-solvents which can be used to absorb
solvents from the dissolved PVDF solution
Non-solvent
Surface tension
Methanol
22.61 at 20 deg C.
Ethanol
24
Isopropanol
21.7 at 20 deg C.
Butanol
24.6 at 20 deg C.
[0077] FIG. 11 is a compilation of the maximum pore sizes and N 2 flow as a function of the non-solvent bath temperature. It is known that water surface tension is inversely proportional to temperature. Temperature is also a measure of average molecular motion—low temperature means low average molecular motion and therefore slows diffusion. This is in contrast to the description in Michaels '024.
[0078] FIG. 12 is a comparison of PVA (polyvinyl alcohol) coating over PVDF membrane on the left and non-coating on the right. The picture illustrates that vapor permeation is not only influenced by the maximum pore sizes, but is also a function of porosity on the surface and of porous structure. The PVA coating covers the opening of the pores and has higher burst strength, which further increases the practical waterproofness of the membrane. Best performance seems to occur at a maximum pore size of 300 nanometers. One can also see that the pores are round, unlike the irregular pores of the Gore membrane.
[0079] FIG. 13 shows a cross section of the fabric, which has a PVDF porous layer in which large vacuoles are embedded to form an extended surface, and with a PVA hydrophilic coating. This is just an example of what can be manufactured.
[0080] FIG. 14 shows the effect of soaking time during membrane gelation in the non-solvent bath. Gelation is a diffusion process in which the solvent is pulled from the solute leaving the gel behind to form a membrane. This illustrates that the soaking time affects the final porous structure. In this example the process only allows the non-solvent to penetrate the solution from one side. In the case of a coating on a fabric the non-solvent may enter from both sides and so the soaking time will be cut in half. Thinner coatings also will cut down the diffusion time. Finally, mass transfer is similar to heat transfer in that under convective conditions the soaking time is dramatically reduced.
[0081] FIGS. 15 ( a ), ( b ), and ( c ) and FIG. 16 are typical examples of N 2 flow for a given solid concentration (15% in FIG. 15 , 20% in FIG. 16 ) versus different mixtures of water and methanol varying from pure water to pure methanol in a non-solvent bath. The resulting small pore size of less than 0.1-micron diameter obtained when using pure water provides high water resistivity but with slower N 2 flow under differential pressure. It is however very soft. With pure methanol and no water the pore size approaches that of 1.0 micron and N 2 flow is high but the membrane is under tension and is therefore subject to breakage. As shown in the plot somewhere in between the maximum pore diameter is about 9.3 microns and there is still with fairly high N 2 flow. Fabric made with intermediate mixtures of solvent and non-solvent has reasonable elasticity.
[0082] From the above figure, it can be seen that the effect (described in FIG. 9 ( b )) of a high surface tension non-solvent going towards a low surface tension is to cause the pore size to increase and pore density to decrease (as shown by an increased nitrogen flow rate), with a remarkable dip in pore size and nitrogen flow rate at the point of transition into a membrane with skin layer. Beyond this point it goes back to larger pore size and nitrogen flow rate. The dip occurs at about the solute surface tension as illustrated in FIG. 9 ( b ). It is also interesting to see that the preparation of the solution involves a memory effect in that when the solution was prepared at higher temperature (say 56° C.) the casting, even if done at room temperature, has a pore size smaller than that from the solution prepared at 33° C. The higher non-solvent bath temperature changes the pore size and porosity, indicating that the diffusion rate of solvent into the non-solvent can be controlled by the bath temperature. At high solid content the dip occurs closer to the solvent surface tension and the dip effect is less pronounced.
[0083] The walls that form around the bubbles have to be broken down in order to allow vapor or nitrogen gas to flow. When the non-solvent and solution have the same surface tension, the force to pull the web apart either by tension or by compression is not there, resulting in a complete bubble structure with no communication between them.
[0084] FIG. 17 illustrates a typical design of a fabric coating machine. It uses mass transfer technology to set up a convective non-solvent bath such that there is a gradient of concentration of the solvent. The solvent content is high at the entrance of the non-solvent bath and low or no solvent at the exit end of the non-solvent bath. A low surface tension solvent for PVDF and “Viton”® fluoroelastomer can prevent rapid solvent diffusion and immediate gelation. As the non-solvent penetrates the coated film it is desired that the solvent content in the non-solvent mixture diminish at a constant rate so that the porous structure remains as unifoirm as possible. By controlling the rate of diffusion one can control the pore size, the porosity and the softness of the membrane and final fabric.
[0085] This simplified figure describes the entrance of the coated fabric into the non-solvent bath at the end where there is a high concentration of solvent, this being controlled by drainage of the non-solvent bath (sometimes called the developer bath), and pure non-solvent is added to the developer tank at the other end where coated fabric or membrane is being taken out of the developer tank and going into a drying tunnel. The amount of pure non-solvent liquid is monitored to keep the tank liquid level constant. For example, if the non-solvent is methanol (which has a very low surface tension), it enters the developer tank at the fabric exit end and if the solvent is DMAC this is mixed into the methanol by diffusion. The high concentration of DMAC increases the surface tension of the non-solvent in situ such that the surface tension is higher than the pure methanol liquid, so the resulting porous membrane has less tensile stress and smaller pore size and is softer.
[0086] As another example, if the non-solvent is pure water, then where the coated film enters the developer tank the solvent (e.g. DMAC) with a relatively high concentration will lower the surface tension of water and also therefore the compressive stress at the membrane surface so it will not form a very tight skin surface with very small pores; instead it will have moderate pore diameter with high porosity. The membrane still has a degree of softness suitable for clothing purposes.
[0087] In FIG. 17, 151 is the roll of fabric, 152 is the fabric under tension to be coated. 153 is the knife coater and 154 the non-solvent tank or developer tank. 155 represents a number of rollers guiding the coated fabric under tension submerged in non-solvent liquid; 156 , a number of baffles guiding the non-solvent flow in the opposite direction of fabric flow; 157 , the non-solvent feed; and 158 is the solvent recovery process.
DESCRIPTION OF THE INVENTION
[0088] A new PVDF membrane making method is designed to have pore sizes under control from nanometer range to 10 microns in hydraulic diameter with a sponge like structure without articulated walls, stressed in a slightly compressed mode so that when flexed it is not subject to tensile stress and so does not break.
[0089] The sponge structure should be more than 50% empty so that it is highly vapor permeable. Under a thin skin at the exit side of the membrane the structure has large pockets which increase its effective area so that it is highly permeable to water vapor. The thin skin prevents the entry of liquid water. Unlike “Gore-Tex”® material, this membrane is directly coated over the fabric and is not glued to it. It is also softer. A thin hydrophilic layer is coated over the PVDF membrane as described in the present applicant's previous U.S. Pat. Nos. 4,419,187; 4,476,024; 4,419,242; 4,265,713; and 4,316,772, and optionally a net protection layer on top of that.
[0090] Prior art solvent/non-solvent membrane making is according to the teachings of Michaels '024 as seen in FIG. 1 thereof. Successful membrane making is in the relationship between the concentration of solids in solvent and percentage of solvent being removed by the non-solvent. The solvent can be a mixture of more than one liquid. The non-solvent is chosen to be very miscible with the solvent, with strong mutual diffusion, coefficients.
[0091] What was not addressed by Michaels '024 was the proportion of solvent/non-solvent and the surface tension of the non-solvent relative to the solid solution.
[0092] Typically the non-solvent is methanol or ethanol, which are hydrophilic to PVDF. The solvent is an organic compound such as DMAC or DMSO (see Table 1). The solidification process pulls away the solvent so quickly (the leaching process) that pores form on the surface layer. The porous structure is highly stressed under tension, resulting in a strong but brittle membrane with larger pore diameters.
[0093] If the non-solvent is water (which is highly hydrophobic with respect to PVDF) the solidification process removes solvent and puts the porous structure under compression. A skin layer is formed with small pore sizes and with vacuoles underneath which extend the vapor permeation surface area. The rest of the porous structure is under compression so when the membrane is folded this releases the compression stresses and the membrane becomes soft and pliable. The diffusion rate between the solvent and non-solvent is found to be temperature dependent and solid concentration dependent. The resultant membrane is dense in structure and is not as porous.
[0094] It is further discovered that the process can be controlled by mixing methanol or another hydrophilic non-solvent with water or another hydrophobic non-solvent such that the surface tension of the non-solvent mixture against the PVDF solution imposes various degrees of stress on the membrane structure all the way from compression to tension. In addition with variations in solid concentration, the solute temperature and non-solvent surface tension and temperature, pore size and pliability can be controlled as specified by the customer. This allows production of a PVDF membrane with better breathability and more waterproof than in the “Teflon”® ePTFE structure.
[0095] The invention is further illustrated by the following hypothetical examples:
Example 1
[0096] PVDF powder in the range of 10% to 20% solid content is dissolved in a mixing vessel with one of the solvents listed in Table I. PVDF is in powder form. Adding solvent over powder under cover of the vessel with a stirring mechanism should perform the mixing. The solution should be thoroughly stirred until there is no sign of any solid powder. The solution usually is filtered through a fine mesh and then pulled into a degassing vessel by a vacuum pump. The air is then let in which compresses the solution. This process is repeated until there is no rise of the liquid surface (because of de-gassing) under vacuum.
[0097] The pre-mixed solution has a fairly good shelf life if it is kept sealed to avoid any moisture penetration.
[0098] If fabric is to be coated, the fabric is pre-cleaned and all the particles and unwanted fine fibers sticking out are removed. The fabric is loaded on a knife coating machine to be coated. The solution of PVDF is fed to the knife coater as the fabric is pulled through it. The fabric is coated to a pre-determined thickness that may be automatically controlled. The coated fabric is then dipped into the non-solvent solution. The fabric is soaked long enough to thoroughly remove most of the solvent and is then fed into a drying channel under tension. After that it is ready for more treatment such as the addition of a hydrophilic coating, a net structure, or a spray-on a water repellent such as “Scotchgard”®. The fabric can then be rolled up for shipment or storage.
Example 2
[0099] The non-solvent is water and the solvent is for example DMSO or DMAC. This causes a reduction of the surface tension of the non-solvent and so of the diffusion rate of the solvent from the solution.
Example 3
[0100] The fabric is fed in at the end of the non-solvent bath where the solvent content is high. By the time it reaches the other end of the developer tank the solvent concentration is approximately zero, so all the solvent is removed from the fabric. The fabric is then fed into a drying tent to remove all the non-solvent. The solvent content is controlled by drainage from the fabric-feeding end of the tank.
[0101] Experience has shown that if the fabric is fed through a highly hydrophobic non-solvent bath it should be under strong compression because the compression force of the porous structure during gelation causes shrinkage. Once it is gelled the wrinkled surface cannot be stretched without some damage.
[0102] If the non-solvent bath is hydrophilic the fabric still needs high enough tension so that the porous structure can be relieved of its stress once the fabric tension is removed.
[0000] The Preferred Embodiment of the Method and Product
[0103] A preferred embodiment of the invention is a method using non-solvent surface tension and concentration of a solid of a hydrophobic material dissolved in a solvent to produce a hydrophobic porous membrane or a coated layer on a fabric. The surface tension of the non-solvent is used to control the maximum pore diameter, the porosity and pre-stress in the porous structure for softness control. A possibility is to use a low surface tension solvent mixed with the high surface tension water as a means for surface tension control. Another method is by controlling the developer bath temperature as most liquids have lower surface tension at higher temperature.
[0104] Another step in the process is to leach the solvent out of the solution of solute and solid by mixing with the non-solvent in situ so that a solvent concentration gradient is set up which controls the rate of solvent diffusion out of the solute during the gelation process. This keeps the porosity constant.
[0105] Using PVDF as the hydrophobic material, this process can be controlled so that the maximum pore diameter will fall in the range of 0.05 to 1.0 micron. By varying the solid concentration in the solution, other desired pore diameters can be made also.
[0106] The PVDF membrane is developed in a high water concentration non-solvent liquid such that the resulting membrane will be under various degrees of pre-stress and under compressive force, which is how the membrane is made soft.
[0107] Solid concentration in the solvent can be varied from 10% to 25%; as a result the porosity can be varied as desired.
[0108] To make the porous structure uniform, a constant diffusion rate of the solvent is needed. The non-solvent bath temperature should be low to produce uniform small pores with sufficient latitude of solid concentration from 12.5% to 17%.
[0109] The pores should be as round as possible so that a hydrophilic coating can be applied without causing pore contamination.
[0110] To be waterproof with a 60 mph raindrop velocity the maximum PVDF membrane pore size should be under 0.3 micron.
[0111] To be waterproof to 100 mph raindrop velocity the maximum pore size should be 0.15 micron for a PVDF membrane.
[0112] Breathability of the membrane should be greater than at least 4,000 g/m 2 /day, preferably in the range of 5,800 g/m 2 /day to 15,000 g/m 2 /day.
[0113] As a coated fabric the breathability should be greater than 3,600 g/m 2 /day and waterproof at a 100-psia static pressure and soft enough to pass U.S. Army uniform specifications.
[0114] As the best performance fabric the waterproofness should be better than 60 mph rain drop velocity and breathability should be over 6000 g/m 2 /day.
[0000] Applications
[0115] A hydrophobic membrane made of PVDF and other hydrophobic plastics instead of “Teflon”® resin has many applications as described below:
[0116] 1. One of the biggest advantages of the PVDF membrane is that it can be molded into different shapes to provide a waterproof and breathable partition. In particular, it can be used as an artificial skin for dressing skin wounds. Most bandages have small holes outside the cotton cheesecloth pad for the wounds to breath. It is a problem if the patient has a large skin area damaged, such as with a bum patient. First the dressing should not stick to the wounds because changing dressings can be a very painful experience. Second, the area should allow water to evaporate so appropriate healing can take place naturally without additional swelling. The artificial skin can prevent foreign objects unintentionally touching the wounded surface and so prevent germs from accumulating. The wounded surface of a body has very unusual contours. “Teflon”® membrane has to be prefabricated and is difficult to fit to a certain contour. With the above described solvent/non-solvent membrane making process, a coating of solvent with PVDF can be applied to the skin and immediately washed by a non-solvent, preferably water. The solvent should be non-toxic, for example DMSO, and the most appropriate non-solvent is water. DMSO penetrates human skin with a very high diffusion rate. Sometimes a mixture of a drug and DMSO is used to allow the drug to penetrate into the body without injection. One of the side effects of DMSO is to make the patient immediately taste garlic in their mouth. If this process is carried out very quickly, and the patient drinks a large quantity of water, DMSO should be discharged from the body. DMSO at one time was considered to be helpful in reducing swelling of joins in arthritis patients. This artificial skin forming in situ on the burnt skin is like a cast on broken bones. The body temperature drives the water out of the micropores and leaves the hydrophobic membrane.
[0117] 2. Because of its hydrophobic nature, PVDF porous membranes can be used in air filters, for example as the air intake filter of an automotive engine or even more appropriately as the air intake filter for small airplane engines. The membrane would have a non-woven paper backing and would not allow water in droplet form to enter the intake manifold.
[0118] 3. An extra thin coating of PVDF on a thin paper backing could replace cloth curtains used in hospitals around a patient's bed. This would reduce contamination by germs, which tend to attach to hydrophilic surfaces. In the event of being soiled by drugs or other fluids the curtain could be thrown away.
[0119] 4. This PVDF membrane can be stitched using ultra-sound which is not true of the “Teflon”® membrane. A PVDF membrane bag filled with water could be used to maintain the moisture content of a package. Certain food products have a drying agent to keep the package dry and the food crispy and tasty. On the other hand, there are also foods which need to be kept in a moist atmosphere. For example, bread and fresh fruit would benefit from a sealed water-filled bag made of PVDF to keep them fresh and moist. Other examples are packaging of flowers for shipping a long distance away: too much water and the cargo is too heavy, not enough moisture and the flowers will dry out. Similar considerations apply for exotic fruits and vegetables.
[0120] 5. The membrane can be used to package time-release drug patches. It is difficult to find materials that will not interact with the drug and its solvent based chemicals. As long as the solvent-based chemicals do not interact with PVDF, there will be no problem. Fortunately (see Table I) only a very limited number of chemicals dissolve PVDF.
[0121] The above examples are only a few of all the possible applications. This product is by no means restricted to the application of the above-cited examples.
[0000] Discussion
[0122] Highly breathable and waterproof fabric is desirable for rain gear, sports clothing, shoe covering, hats etc. Several attempts have been made to produce a fabric that is soft, porous and waterproof using PVDF as the hydrophobic, material but, these were not successful. This invention, based on years of data compilation, allows one to control the pore diameter, porosity and softness. “Viton”® as a flouroelastomer can be added to PVDF to soften the membrane, but “Viton”® elastomer is very expense so a combination of the correct non-solvent bath surface tension with little or no “Viton”® elastomer should be used. Depending on the degree of softness required, other plasticizers can be used such as long chain di-carboxylic acid esters with a “springy” structure, such as Dibutyl sebacate, Dioctyl adipate and others; they do not degrade the hydrophobic properties of PVDF very much. This provides an ideal fabric which is waterproof and highly breathable, with sufficient softness to be a quality fabric but much cheaper than a “Teflon”® based fabric. “Teflon”® material has a slight advantage in that it has a lower surface tension than PVDF but no solvent can dissolve “Teflon”® resin so it has to be produced by physical means and therefore at a high cost. The PVDF fabric not only costs less to produce, but outperforms the “Teflon”® based fabrics. One of the reasons is that, as described above, the present invention enables total control of pore size range and also of fabric softness. Also, the “Teflon”® based fabric has to use glue to laminate the final fabric structure. The pre-stress control during membrane gelation of PVDF gives the final product as desired.
[0123] In summary, the invention provides, inter alia, a method whereby a membrane is made out of PVDF or similar relatively inert plastic using a solvent/non-solvent process, in which pore size and other structural characteristics can be controlled by varying parameters such as solvent/non-solvent concentrations, casting bath temperature, solvent/non-solvent bath temperature, percent solids and bath time, and wherein small quantities of an additive (“Viton”® fluoroelastomer) may or may not be added to improve elasticity. The method of the invention can produce a soft fabric suitable for clothing. It can make a hydrophobic membrane that can be coated directly onto fabric without requiring intervening glue, and/or can also be stitched. A hydrophobic membrane can be produced that is able to resist water droplets at a pressure equivalent to a 60 mile per hour wind; that can pass a quantity of water vapor of between 4,000 g/m 2 /day and 10,000 g/m 2 /day at normal human body and ambient temperatures; and has pore size of between 100 nm and 1000 nm. Moreover, by the method of the invention there can be produced a membrane that is highly hydrophobic, but is covered with a very thin hydrophilic layer, which does not affect breathability of the membrane but does improve waterproofness.
[0124] It is to be understood that the invention is not limited to the features and embodiments hereinabove specifically set forth, but may be carried out in other ways without departure from its spirit.
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A method for creating a highly breathable and waterproof fabric based on hydrophobic plastic (such as PVDF) as a membrane layer. This new fabric allows higher water vapor throughput and better water resistance than other PVDF and ePTFE membranes. This is achieved through control of pore size, thus creating a spongy porous structure, pre-stressing to make the membrane and subsequent laminated fabric soft, and a microscopically folded structure which increases the surface area for the porous media, thus gaining higher throughput, waterproofness and comfort. In addition, the invention provides a method of controlling pore size distribution, increased porosity and pre-stress relief during the gelation proces.
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PRIORITY
[0001] This non-provisional application claims priority of Provisional Application No. 61/558,259, filed on Nov. 10, 2011. The entirety of Application No. 61/558,259 is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to fastening systems for absorbent personal care articles. More particularly, it relates to absorbent personal care articles having foldable wings or flaps that can be employed to properly position and attach the absorbent articles to undergarments or other articles of clothing.
BACKGROUND
[0003] Absorbent personal care articles such as sanitary napkins, panty liners and incontinence pads commonly utilize a pair of wings or flaps which are used to help secure the article in place to the wearer's undergarments. Generally, the wings are folded around the outside of the wearer's undergarment and attach to the outside of the undergarment via adhesive or other fastening means. Once secured to the undergarment the wings help reduce the likelihood that the article will become dislodged and move out of position. Examples of such foldable wing fasteners are shown and described in U.S. Pat. No. 4,589,876 Van Tilberg; EP051190B1 Pigneul; U.S. Pat. No. 5,401,268 Rodier; and EP1208823A1 Hohmann.
[0004] However, while wings of various size and shape have previously been used, there remain a number of drawbacks to these designs. First, many wings do not adequately prevent the article from bunching or twisting due to the stresses imparted on the article as the wearer moves. Second, misapplication of the article to the undergarment can also greatly increase the risk of leakage. In this regard, it can be difficult for wearers to place conventional wings properly onto their undergarment and when the wings are improperly fastened the absorbent article can be bunched or partially twisted as donned or more easily become twisted or bunched with the wearer's movement. Twisting of the article and/or the deformation of the article when worn can result in the article being at an angle relative to the wearer as opposed to being perpendicular to or flat against the wearer. When the article is sidewardly angled to the wearer the ability of the article to take in and absorb fluids can be reduced to an extent such that the article functions significantly less effectively than desired. Further, bunching of the article results in the article covering considerably less area under the vaginal region than desired. Thus, such unwanted twisting and bunching of the article can result in increased frequency of leakage and staining of the wearer's garments.
[0005] Thus, there exists a continued need for an absorbent personal care article having foldable wings that assist the wearer with proper placement and donning of the article.
[0006] There further exists a need for such an article wherein the foldable wings also help maintain the article in an uncontorted and/or generally flap shape in order to minimize the incidence of leakage.
SUMMARY OF THE INVENTION
[0007] The present invention addresses problems experienced with the flap designs of the prior art by providing an absorbent personal care article including (i) a left flap having first and second peaks and a furrow positioned there between, and (ii) a right flap having a first peak. The left and right flaps are positioned on opposed longitudinal sides of the article and sized such that, when the flaps are folded under the article and extended so that they lay flat against the liquid impermeable backsheet, the right flap peak extends across the longitudinal centerline of the article and into the left flap furrow.
[0008] In a further aspect of the invention, the left and right flaps can be integrally shaped and sized such that the wings substantially inter-mesh with or conform to one another when folded under and around the article. In still a further embodiment, the left and right flaps may define a space or gap between them along the substantial length of the flaps when the flaps are folded under the article lying flat adjacent the liquid impermeable backsheet. In an alternate embodiment, the left and right flaps can be sized and shaped so as to form one or more discrete areas of overlap when the flaps are folded under and around the article and lay flat against the liquid impermeable backsheet.
[0009] In a further aspect of the invention, the left and right flaps may include fasteners located on the garment facing side of the flap peaks such that the fastener extends across the longitudinal centerline of the article and either into the furrow of the opposed flap or over the opposed flap. This may be achieved, in one embodiment, by placing the fastener proximate the outer edges of the flap peaks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a representative partially cut away plan view of one embodiment of a sanitary napkin of the present invention in a flat and unfolded state.
[0011] FIG. 2 is a representative plan view of a sanitary napkin of an alternate embodiment of the present invention suitable for use with both traditional and tanga style underwear.
[0012] FIGS. 3-6 are enlarged views of individual embodiments of wings of the present invention shown in an inter-meshing relationship as folded directly under the personal care article lying flat against the backsheet.
DESCRIPTION OF THE INVENTION
[0013] In reference to FIGS. 1 and 2 , the drawings show absorbent personal care articles in a flat and unfolded state. Except as otherwise noted, discussion of dimensions of the article and/or the positions of individual components thereof are in reference to the article being in a flat and unfolded state and further, in the event elasticated components are utilized, dimensions are in reference to the article being in an uncontracted state. Further, as used herein, the terms “comprising” or “including” are inclusive or open-ended and do not exclude additional unrecited elements, compositional components, or method steps. Accordingly, the terms “comprising” or “including” encompass the more restrictive terms “consisting essentially of” and “consisting of.”
[0014] In reference to FIG. 1 , an absorbent personal care article 10 is provided comprising a liquid permeable topsheet 12 , a liquid impermeable backsheet 14 and an absorbent core 16 . The absorbent article 10 has a lengthwise or longitudinal direction and a widthwise or transverse direction. The longitudinal centerline of the article 10 is shown as line “L” and the transverse centerline of the article 10 is shown as line “T”. The absorbent article 10 can comprise any one of numerous elongate shapes including, but not limited to, triangular, rectangular, dog-bone and elliptical. In addition, it will often times be desirable for the article to have rounded corners and/or generally convex ends.
[0015] The absorbent article desirably has a length between about 80 mm and about 450 mm, and still more desirably a length between about 150 mm to about 250 mm. The absorbent article 10 desirably has a maximum width (excluding the wings) between about 40 and about 160 mm, and still more desirably a maximum width between about 65 mm and about 95 mm.
[0016] The absorbent article 10 further includes a first wing 20 and second wing 30 extending from opposite longitudinal sides of the article 10 . The first and second wings 20 , 30 desirably extend from about 20% to about 75% of the length of the article 10 . In a further aspect, the wings desirably have a length, in the longitudinal direction L, of from about 40 mm to about 160 mm, and still more desirably a length from about 95 mm to about 145 mm. The wings can be positioned about the transverse centerline or may be positioned either some distance forward or rear of the transverse centerline as may be desired to better accommodate the particular shape of the article and/or use on a particular style of garment. In addition, while not shown, it is noted that absorbent articles can, if desired, contain more than one set of opposed wings of the present invention.
[0017] A portion of the outside surface of the wings 20 , 30 include one or more fasteners 26 , 36 . The fastener will be selected to releasably engage either a garment or an overlapping portion of an opposed wing. Numerous adhesives and mechanical hook-type fasteners that releasably attach to itself or a user's garments are well known in the art and are suitable for use in connection with the present invention. Pressure sensitive adhesives are particularly well suited for use with the present invention. However, in order to protect the adhesive from contamination or drying prior to use, the adhesive is commonly protected by one or more releasable peel strips as is known in the art. A suitable releasable peel strip is a white Kraft paper having a silicone coating on one side so that it can be easily released from the adhesive. In addition, with respect to wing-to-wing attachment, examples of specific mechanical hook, adhesive and other fastening systems include but are not limited to those described in WO03/015682 to Hammonds et al.; WO03/015684 to Hammonds et al. and US2004013317 to Steger et al.
[0018] The first wing 20 includes at least a first peak 21 and a second peak 22 and a furrow base 24 spanning the peaks; the inner edges of the first and second peaks 21 , 22 and the furrow base 24 define a groove or furrow 24 A in the first wing 20 . The shapes of the peaks and furrow(s) can vary as desired including both rectilinear and curvilinear configurations. The wing 20 and components thereof are sized such that, when the wing 20 is folded around the underside of the article and the wing 21 lays flat against the backsheet 14 , portions of the first and second peaks 21 , 22 extend across the longitudinal centerline L whereas the furrow base 24 does not extend across or even to the longitudinal centerline. Thus, the specific dimensions for the wings will be selected in relation to the corresponding width of the absorbent article. In one aspect, the dimension of the peak in the transverse direction may be at least 50% of the width of the adjacent section of the absorbent core. In a further aspect, the distance from the middle of the first peak to the middle of the furrow base 24 is desirably at least about 20 mm and still more desirably between about 20 mm and about 60 mm.
[0019] The second wing 30 includes at least a first peak 31 and first and second shoulders 38 , 39 positioned on opposite sides of the first peak 31 of the second wing 30 . Individual elements of the second wing 30 can have dimensions the same as or similar to those of the first wing 20 . However, as discussed in more detail below, desirably the peaks, furrows, and/or shoulders of the first and second wings are shaped so to coincide with one another. The second wing 30 and components thereof are sized such that, when second wing 30 is folded around the underside of the article and lays flat against the backsheet 14 , portions of the first peak 31 extend across the longitudinal centerline L whereas the shoulders 38 , 39 do not extend across or even to the longitudinal centerline L. The shapes of the peak(s), furrow(s) and/or shoulders can vary as desired including both rectilinear and curvilinear configurations.
[0020] The first and second wings 20 , 30 are positioned along the longitudinal sides of the article 10 wherein the furrow base 24 of the first wing 20 lies in the same plane as the first peak 31 of the second wing. Stated differently, the first and second wings 20 , 30 are positioned along opposed longitudinal sides of the article 10 such that, when the first and second wings 20 , 30 are folded around the underside of the article 10 and extended to lay flat against the backsheet 14 , the first peak 31 of the second wing 30 extends into the furrow 24 A of the first wing 20 (the furrow 24 A of the first wing 20 being defined by the peaks 21 , 22 and furrow base 24 ).
[0021] In one embodiment and in reference to FIG. 3 , the first and second wings 20 , 30 can be sized and shaped so that, when folded around the underside of the article 10 and extended to lay flat against the backsheet 14 , the wings 20 , 30 do not overlap thereby leaving a space or gap “G” between them. In the embodiment shown, the wings 20 , 30 are sized and shaped so that they substantially intermesh but leave a substantially uniform gap “G” between them when folded around the underside of the article so as to lay flat against the backsheet 14 . Desirably in such embodiments the wings leave a gap “G” of less than about 20 mm and still more desirably less than about 15 mm. Thus, in use, the first wing 20 and second wing 30 extend around the crotch portion of the garment, and the first peak 31 of the second wing 30 extends into the furrow 24 A of the first wing 20 in a mating relationship. In a further aspect, the first and second peaks 21 , 22 of the first wing 20 and the shoulders 38 , 39 of the second wing 30 similarly lie in a corresponding relationship having a similar gap between the respective edges. Primary fasteners 26 , 36 , such as pressure sensitive adhesive, can be positioned adjacent the outer edges of the peaks such that, when the wings 20 , 30 are folded under the article so that the wings 20 , 30 lie flat against the backsheet 14 , the fasteners 26 , 36 lie on the opposite side of the longitudinal center line relative to which the wing is attached. The wings may also optionally include secondary fasteners 27 , 37 located proximate to outer edges of the furrow base 24 , shoulders 38 , 39 or base of the peaks 21 , 22 , 31 . The primary fasteners 26 , 36 may lie entirely or partially beyond the longitudinal center line when the wings 20 , 30 are folded around the underside of the article 10 and lay flat against the backsheet 14 . As shown in FIG. 3 , when the wings 20 , 30 are folded around the underside of the article 10 and lay flat against the backsheet 14 , the primary fasteners 26 , 36 are positioned entirely on the opposite side of the longitudinal center line “L” relative to the side that the wing extends from.
[0022] In a further embodiment, and in reference to FIGS. 4 and 5 , the first and second wings 20 , 30 are sized and shaped so that the wings form overlap regions 50 when folded around the underside of the article 10 and extended to lay flat against the backsheet 14 . Thus, in use, the first wing 20 and second wing 30 can extend around the crotch portion of the garment and the first peak 31 of the second wing 30 extends over the furrow base 24 of the first wing 20 in an overlapping relationship. In this embodiment the wings are sized and shaped so as to inter-mesh in a manner such that the wings superpose one another. When the wings 20 , 30 are folded around the underside of the article 10 so as to lay flat against the backsheet 14 , individual overlap regions 50 formed by the superposed portions of the first wing 20 and second wing 30 desirably each comprise an area of at least about 50 mm 2 , more desirably between about 50-600 mm 2 and still more desirably between about 100-250 mm 2 . In a particular embodiment and in reference to FIG. 4 , the dimension of the wings relative to the width of the article 10 (exclusive of the wings) is such that the first and second wings 20 , 30 form overlap regions 50 adjacent the outer edges of the peaks 21 , 22 and 31 extending generally in the longitudinal direction. In a further particular embodiment and in reference to FIG. 5 , the shape and dimension of the wings 20 , 30 relative to the width of the article 10 (exclusive of the wings) is such that the first and second wings 20 , 30 form overlap regions 50 adjacent the side edges of the peaks 21 , 22 and 31 extending generally in the transverse direction T. The wings 20 , 30 can include fasteners (not shown) positioned on one or both areas of the wings intended to overlap and directly engage one another. Desirably the fasteners are positioned adjacent the edges of the peaks 21 , 22 , 31 . The wings may optionally include secondary fasteners such as pressure sensitive adhesive located in one or more areas of the wings 20 , 30 intended to overly the garment when worn.
[0023] In still a further embodiment and in reference to FIG. 6 , the second wing 30 can have a shape the same as or substantially similar to that of the first wing 20 . Thus, in this embodiment, the first wing 20 and second wing 30 each have first peaks 21 , 31 , second peaks 22 , 32 and furrow bases 24 , 34 respectively. The first peaks 21 , 31 and second peaks 22 , 32 are sized so as to extend beyond the longitudinal centerline “L” when the wings 20 , 30 are folded under the backside of the article and extended so as to lay flat against the backsheet 14 . In addition, the wings 20 , 30 are off-set from one another such that, when the wings are folded around the underside of the article and extended so that the wings 20 , 30 lay flat against the backsheet 14 , the first peak 31 of the second flap 30 extends into the furrow of the first wing 20 and the first peak 21 of the first wing 20 extends into the furrow of the second wing 30 . As will be readily understood by one skilled in the art, the multiple peaks of the wings can be configured to have non-overlapping relationships, overlapping relationships or both an overlapping and non-overlapping relationship. Accordingly, the wings will contain a plurality of fasteners in accord with the selected overlap scheme and fastening mechanism. In reference to FIG. 6 , the primary fasteners 26 , 36 traverse the longitudinal centerline “L.”
[0024] The front and rear halves of each wing can be symmetrical or asymmetrical as desired. For example, in one embodiment and in reference to FIG. 1 , the front and rear halves of the wings, i.e. the halves above and below the transverse centerline in the longitudinal direction, are symmetrical. The absorbent core in the embodiment of FIG. 1 is also symmetrical and commonly it will be desirable for the wings to be symmetrical when the absorbent core is symmetrical. In an alternate embodiment, and in reference to FIG. 2 , the absorbent core 16 is shaped having wider front (F) and narrower rear (R) sections in order to better conform to a tanga or thong type undergarments as well as for use in connection with certain overnight pads. The wings are therefore configured to correspond with the difference in the width of the article 10 . More specifically, the first peak 21 of first wing 20 , which is positioned adjacent a wider section of the absorbent core 16 , has a greater dimension in the transverse direction than the rearward second peak 22 of the first wing 20 . In the embodiment shown in FIG. 2 the wings 20 , 30 are centered about the transverse centerline “T” of the article however, as noted previously, the wings 20 , 30 can be positioned either forwardly or rearwardly relative to the transverse centerline as desired.
[0025] With respect to the general function and composition of the article 10 , the backsheet or outer cover 12 functions to isolate absorbed fluids from the wearer's garments and therefore comprises a liquid-impervious material. In one aspect the outer cover may optionally comprise a material that prevents the passage of liquids but allows air and water-vapor to pass there through. The outer cover can comprise a single layer or multiple layers and these one or more layers can themselves comprise similar or different materials. Suitable backsheet materials include, but are not limited to, polyolefin films, nonwovens and film/nonwoven laminates. The particular structure and composition of the outer cover may be selected from various known films and/or fabrics with the particular material being selected as appropriate to provide the desired level of liquid barrier, strength, abrasion resistance, tactile properties, aesthetics and so forth. Suitable outer covers include, but are not limited to, those described in U.S. Pat. No. 4,578,069 to Whitehead et al.; U.S. Pat. No. 4,376,799 to Tusim et al.; U.S. Pat. No. 5,695,849 to Shawver et al; U.S. Pat. No. 6,075,179 et al. to McCormack et al. and U.S. Pat. No. 6,376,095 to Cheung et al.
[0026] The topsheet 14 functions to receive and take in fluids, such as urine or menses, and therefore comprises a liquid permeable material. Additionally, topsheets can further function to help isolate the wearer's skin from fluids held in the absorbent core 16 . Topsheets can comprise a single layer or multiple layers and these one or more layers can themselves comprise similar or different materials. Topsheets are well known in the art and may be manufactured from a wide variety of materials such as, for example, porous foams, reticulated foams, apertured plastic films, woven materials, nonwoven webs, aperture nonwoven webs and laminates thereof. It is also well known that one or more chemical treatments can be applied to the topsheet materials in order to improve movement of the fluid through the topsheet and into the article. Suitable topsheets include, but not limited to, those described in U.S. Pat. No. 4,397,644 to Matthews et al.; U.S. Pat. No. 4,629,643 to Curro et al.; U.S. Pat. No. 5,188,625 Van Iten et al.; U.S. Pat. No. 5,382,400 to Pike et al.; U.S. Pat. No. 5,533,991 to Kirby et al.; and U.S. Pat. No. 6,410,823 to Daley et al. Between the liquid pervious topsheet 12 and liquid impervious backsheet 14 is positioned an absorbent core 16 . The absorbent core 16 functions to absorb and preferably “lock-up” the bodily fluids that pass into the absorbent article 10 through the topsheet 12 . The absorbent core can comprise a single layer or multiple layers and these one or more layers can themselves comprise similar or different materials. In order to efficiently and effectively utilize the absorbent capacity of the article, it is common for the absorbent core to include one or more liquid distribution layers or wicking layers in combination with a highly absorbent layer that preferentially absorbs and retains the liquids. Suitable wicking layers include, but are not limited to, bonded-carded webs, hydroentangled nonwoven webs, or spunbond webs containing fibers treated with or containing one or more topical agents that improve the contact angle with the bodily fluid and/or modify the flow properties of the bodily fluid. Highly absorbent layers often include, but not limited to, batts or webs containing wood pulp fibers, superabsorbent particles, synthetic wood pulp fibers, synthetic fibers and combinations thereof. The absorbent core may comprise any one of a number of materials and structures, the particular selection of which will vary with the desired loading capacity, flexibility, body fluid to be absorbed and other factors known to those skilled in the art. By way of example, suitable materials and/or structures for the absorbent core include, but are not limited to, those described in U.S. Pat. No. 4,610,678 to Weisman et al.; U.S. Pat. No. 6,060,636 to Yahiaoui et al.; U.S. Pat. No. 6,610,903 to Latimer et al.; US20100174260 to Di Luccio et al.; and U.S. Pat. No. 7,358,282 to Krueger t al.
[0027] The shape of the absorbent core can vary as desired and can comprise any one of various shapes including, but not limited to, generally triangular, rectangular, dog-bone and elliptical shapes. In one embodiment, the absorbent core 16 has a shape that generally corresponds with the overall shape of the article 10 such that the absorbent core terminates proximate the edge seal 18 and wings 20 , 30 . The dimensions of the absorbent core can be substantially similar to those referenced above with respect to the absorbent article 10 ; however it will be appreciated that the dimensions of the absorbent core 16 while similar will often be slightly less than those of the overall absorbent article 10 in order to be contained therein.
[0028] As previously indicated, the absorbent core 16 is positioned between the topsheet 12 and backsheet 14 . The individual layers comprising the article can be attached to one another using means known in the art such as adhesive, heat/pressure bonding, ultrasonic bonding and other suitable mechanical attachments. Commercially available construction adhesives usable in the present invention include, for example Rextac adhesives available from Huntsman Polymers of Houston, Tex., as well as adhesives available from Bostik Findley, Inc., of Wauwatosa, Wis. In one embodiment, and in reference to FIG. 1 , the absorbent core can be sealed between the topsheet 12 and backsheet 14 along the perimeter of the absorbent core 16 along edge seal 18 formed by the application of heat and pressure to melt thermoplastic polymers located in the topsheet 12 and/or backsheet 14 .
[0029] The wings can be constructed from materials described above with respect to the topsheet and backsheet. In one embodiment, the wings can comprise an extension of a layer of material within the topsheet and/or backsheet. By way of example and in reference to FIG. 1 , the wings 20 , 30 can be formed by an extension of the topsheet 12 and backsheet 14 that are welded together along edge seal 18 . Such wings can be integrally formed with the main portion of the absorbent article. Alternatively, the wings can be formed independently and separately attached to an intermediate section of the article. Wings that are made independent of the other components of the absorbent article can be welded onto or adhesively joined to a portion of the topsheet and/or backsheet. In addition, as is known in the art, when cutting materials to the desired shape it is preferable to arrange the components so as to minimize waste. Examples of processes for manufacturing absorbent articles and wings include, but are not limited to those described in U.S. Pat. No. 4,059,114 to Richards; U.S. Pat. No. 4,862,574 to Hassim et al. WO1997040804 to Emenaker et al.; U.S. Pat. No. 5,342,647 to Heindel et al.; US20040040650 to Venturino et al.; and U.S. Pat. No. 7,070,672 to Alcantara et al.
[0030] In order to further assist with the maintenance of the article 10 in the desired location on the undergarment, garment adhesive (not shown) may be applied to the garment facing side of the backsheet 14 . The use of garment adhesive on the backsheet to help secure placement of an absorbent article on the garment is well known in the art and there are numerous adhesive patterns and releasable peel strips suitable for use with the present invention. Examples of suitable garment adhesives, patterns and release sheets include, but are not limited to, those described in DE700225U1; U.S. Pat. No. 3,881,490 to Whitehead et al.; U.S. Pat. No. 3,913,580 Ginocchio; U.S. Pat. No. 4,337,772 to Roeder et al.; GB1349962 Roeder; U.S. Pat. No. 4,556,146 to Swanson et al.; and US20070073255A1 to Thomas et al.
[0031] The absorbent articles of the present invention may further include one or more components or elements as may be desired. By way of example, the absorbent article may optionally include slits, voids or embossing on the topsheet and/or absorbent core in order to improve fluid intake, fluid distribution, stiffness (bending resistance) and/or aesthetic appeal. As a specific example and in reference to FIGS. 1 and 6 , embossing 17 can extend into both the topsheet 12 and absorbent core 16 . Examples of additional suitable embossing patterns and methods include, but are not limited to, those are described in U.S. Pat. No. 4,781,710 Megison et al.; EP769284A1 to Mizutani et al.; US20050182374 to Zander et al.; and U.S. Pat. No. 7,686,790 to Rasmussen et al.
[0032] The personal care articles can, optionally, contain one or more additional elements or components as are known and used in the art including, but not limited to, the use of fold lines, individual wrappers, elasticated flaps that extend above the plain of the topsheet in use, additional independent wings such as about the ends, odor control agents, perfumes, and the use of ink printing on one or more surfaces of the topsheet, backsheet, wings or absorbent core. Still further additional features and various constructions are known in the art. Thus, while the invention has been described in detail with respect to specific embodiments and/or examples thereof, it will be apparent to those skilled in the art that various alterations, modifications and other changes may be made to the invention without departing from the spirit and scope of the same. It is therefore intended that the claims cover or encompass all such modifications, alterations and/or changes.
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An absorbent personal care article, such as a sanitary napkin or incontinence pad, having a longitudinal centerline and a transverse centerline and including a pair of opposed first and second wings extending along the longitudinal sides of the article. The first wing includes two or more peaks with furrows there between and the second wing includes one or more peaks. The peaks of the first and second wings are sized and positioned on the article such that when folded under the article and around the wearer's undergarments, the peak of the second wing extends across the longitudinal centerline of the article and into the furrow of the first wing. The inter-meshing wings help wearer's properly don the articles, improve the attachment of the article to the wearer's garment and/or reduce unwanted twisting or bunching of the article during use.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to a fieldbus relay arrangement. In particular, the invention is directed towards a fieldbus relay arrangement and method for implementing such arrangement which makes discrete outputs available using standard function blocks in Foundation® fieldbus and Profibus® fieldbus networks, and which can further utilize the additional functions available to standard Foundation® fieldbus and Profibus® fieldbus network devices.
BACKGROUND OF THE INVENTION
[0002] The use of Fieldbus for Process Control Applications
[0003] Process control systems and methods provide a way for ensuring efficiency, reliability, profitability, quality and safety in a process/product manufacturing environment. Such process control systems and methods can be used for automation, monitoring and control in a wide array of industrial applications for many industry segments, including textiles, glass, pulp and paper, mining, building, power, sugar, food and beverage, oil and gas, steel, water and wastewater, chemicals, etc.
[0004] The conventional process control systems and methods generally operate with a plurality of field devices positioned at various locations on, e.g., a 4-10 mA analog network. These devices include measurement and control devices (such as temperature sensors, pressure sensors, flow rate sensors, control valves, switches, etc., or combinations thereof). Recently, a number of protocols have been introduced which provide a digital alternative to conventional control systems and methods, and which utilize “smart” field devices. These “smart” field devices can provide the same functionality as the conventional devices listed above, and may additionally include one or more microprocessors, one or more memories, and other components incorporated therein. Such smart field devices can be communicatively coupled to each other and/or to a central processor using an open smart communications protocol. These protocols (e.g. Foundation® Fieldbus protocol) have been widely used in manufacturing and process plants. Many of such protocols were developed for non-process control environments, such as automobile manufacturing or building automation, and were later adapted to be used for process control. Some of the more widely used fieldbus protocols include Hart®, Profibus®, Foundation® Fieldbus, Controller Area Network protocols, etc.
[0005] Fieldbus process control systems and methods may also utilize a controller communicatively coupled to each of the smart field devices using an open, “smart” communications protocol, and a server communicatively coupled to the controller using, for example, an Ethernet connection. Moreover, this controller may include a processor, and can receive data from each of the “smart” field devices. These “smart” field devices preferably include a processor for performing certain functions thereon, without the need to use the central host for such functions. The amount of processing by the centralized host generally depends on the type of a control application and protocol used.
[0006] A smart fieldbus device, as configured by a software configurator, may be programmed to execute function blocks. A function block provides the fundamental automation functions that are performed by the process control application—function blocks are essentially a software model which defines the behavior of the process control system. More particularly, the function block is a software logic unit which processes input parameters according to a specified algorithm and an internal set of control parameters, and produces resulting output parameters that are available for use within the same function block application or by other function block applications. The input parameters of one function block may be linked to the output parameters of other function blocks on the fieldbus. The execution of each function block can be scheduled. After the function block is executed using the corresponding input values, its outputs are updated and then broadcast on the network, where they can be read by inputs of other function blocks using this information. These linked function blocks may reside either inside the same field device or in different devices on the network.
[0007] The function blocks replace many of the functions which were traditionally performed by hardware. They provide flexibility in a process control environment, since they may be modified, added or removed, without having to rewire or change the hardware of the system. Different function blocks are defined for use in Foundation® fieldbus and Profibus® fieldbus networks. For example, the Fieldbus Foundation establishes a set of ten standard function blocks for basic control, which are specifically defined in the FF-891 Function Blocks—Part 2 specification. This initial set of 10 function blocks released by the Fieldbus Foundation generally addresses over 80 percent of the basic process control configurations. An additional 19 standard function blocks for advanced control are defined in the FF-892 Function Blocks—Part 3 specification.
[0008] Three different types of function blocks are used in the fieldbus applications. For example, Resource Blocks define parameters that pertain to the entire application process (e.g., manufacturing ID, device type, etc.). Function Blocks encapsulate control functions (e.g., PID controller, analog input, etc.). Transducer Blocks represent an interface to sensors such as temperature, pressure and flow sensors.
[0009] Each function block in the system is identified by a unique tag which is assigned by the user. The parameters of each function block are represented by object descriptions that define how the parameters are communicated on the fieldbus network. Thus, many parameters in the system are uniquely identified by their reference to their block tag and parameter name.
[0010] Each fieldbus device likely has a Resource Block and at least one Function Block with input and/or output parameters that link to other function blocks, either in the same device or in separate devices by using the bus. Each input/output parameter includes a particular value portion and a particular status portion. The status portion of each parameter includes information regarding the reliability of the data contained in the input/output parameter, and instructs the receiving function block as to whether the reliability of contained data is acceptable, uncertain or unacceptable. In addition, a Function Block Application Process (“FBAP”) can specify the handling of control modes, alarms, events, trend reports and views. These features comply with the Foundation® specification in order for the device to be considered interoperable at a User Layer.
[0011] Distribution of control to the field devices can be performed by synchronizing the execution of the function block and transmitting the function block parameters on the fieldbus network. Such function, along with the publication of the time of day to the devices, an automatic switch over to a redundant time publisher, an automatic assignment of device addresses, and a search for parameter names or “tags” on the fieldbus, are generally handled by System Management and Network Management.
[0012] A control strategy may be created through the interconnection of various function blocks contained by the field devices. The control strategy may also be modified without any hardware changes, thus providing another level of flexibility. The creation of the function blocks and control strategies further includes the automatic assignment of device addresses and parameter indexes. The function blocks and control strategies are described in the Foundation® Fieldbus and Profibus® fieldbus specifications, both of which are incorporated herein by reference.
[0013] Relays
[0014] Relays are used in process control and other applications to control a load in response to a control line input as well as to control various conventional devices, such as alarm generators, limit switches and motors. Many types of relays are unintelligent devices that merely conduct a load current when an input voltage is above or below a particular threshold input value. An early conventional relay is generally an electromechanical device in which a solenoid is used to connect two switch contacts. Recently, solid state relays have become more widely used. However, these conventional relay devices are not compatible with the advanced technologies that have recently been developed for intelligent process automation and control.
[0015] Some relays may contain microprocessors and memory, and can perform logic functions: such relays are described in U.S. Pat. No. 6,360,277 the entire disclosure of which is incorporated herein by reference. The relays described in this publication are addressable, can store various protocols internally, and may therefore be inter-operable with various different process control networks. These relays can provide standard discrete outputs for the fieldbus network.
[0016] However, no fieldbus relay exists which can be easily integrated into a fieldbus control scheme by executing fieldbus function blocks, receiving power from the fieldbus network, and performing various other functions which are generally performed by Foundation® or Profibus® fieldbus devices. Such relay may allow the system to be homogenous, and can simplify a control strategy configuration by enabling a seamless integration of traditional discrete-controlled components into an advanced Foundation® fieldbus or Profibus® fieldbus process control scheme.
SUMMARY OF THE INVENTION
[0017] Therefore, a need has arisen to provide a relay arrangement and method which overcomes the above-described and other shortcomings of the conventional systems and processes. According to an exemplary embodiment of the present invention, a fieldbus relay arrangement is provided. The arrangement provides conventional discrete outputs using standard fieldbus function blocks. In one exemplary embodiment of the present invention, the fieldbus relay arrangement includes a central processing unit, a storage arrangement and a relay. The arrangement can execute standard function blocks, and may control outputs of the relay based on this execution. In one exemplary variation, the arrangement may include multiple processors which can be dedicated to various tasks, such as for a communications with the fieldbus network or for processing the function blocks. Additionally, the arrangement may include various types of storage arrangements, e.g., flash memory, RAM, ROM, and EEPROM. The exemplary embodiment of the fieldbus relay arrangement according to the present invention can operate in a manner similar to that of other Foundation® or Profibus® fieldbus devices, e.g., the arrangement may obtain power from the fieldbus, transmit status information via standard status variables defined in the Foundation® and Profibus® fieldbus specifications, etc.
[0018] The exemplary embodiment of the fieldbus relay arrangement according to the present invention may execute a plurality of fieldbus function blocks. These function blocks may include resource blocks, edge trigger and flip-flop blocks, analog alarm blocks, timer blocks, discrete output blocks, arithmetic blocks, input selector blocks, Proportional-Integral-Derivative (PID) control blocks and step-output PID control blocks, etc.
[0019] In another exemplary embodiment according to the present invention, the arrangement may include one or more optically-isolated solid-state relays. The relays may be operated automatically based on the operation of the function block, and/or manually using a tool which can magnetically activate the relays of the arrangement. The arrangement may further include a liquid-crystal display (LCD) for displaying certain information (e.g., device status, etc.).
[0020] One of the advantages of the present invention is that the fieldbus relay can be considered as any other device on the Foundation® or Profibus® fieldbus, and may be operated with the same advanced level of control as any other fieldbus device. Fieldbus control strategies can thereby be configured with uniformity. Further, a conversion of existing control systems to Foundation® or Profibus® fieldbus systems can be simplified since a modification of existing output field elements is likely minimized. The use of the fieldbus relay arrangement according to the present invention makes the use of conventional discrete-controlled devices completely transparent at the fieldbus control configuration level.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] For a more complete understanding of the present invention, the objects satisfied thereby, and further objects, features, and advantages thereof, reference now is made to the following descriptions taken in connection with the accompanying drawings.
[0022] [0022]FIG. 1 is a block diagram of a first exemplary embodiment of a fieldbus relay arrangement according to the present invention.
[0023] [0023]FIG. 2 is a block diagram of a second exemplary embodiment of the fieldbus relay arrangement according to the present invention.
[0024] [0024]FIG. 3 is a front view of a third exemplary embodiment of the fieldbus relay arrangement according to the present invention showing the physical connectors of the arrangement.
[0025] [0025]FIG. 4 is a block diagram of an exemplary embodiment of a portion of the fieldbus relay arrangement according to the present invention coupled to a fieldbus network.
[0026] [0026]FIG. 5 is an exemplary fieldbus installation that includes an exemplary embodiment of the fieldbus relay arrangement of FIGS. 1 - 3 .
[0027] [0027]FIG. 6 is a block diagram of a fourth exemplary embodiment of the fieldbus relay arrangement according to the present invention that can be used for switching to a conventional output device.
[0028] [0028]FIG. 7 is a block diagram of a fifth exemplary embodiment of the fieldbus relay arrangement according to the present invention that can be used for switching to a conventional output device in an alarm-type application.
[0029] [0029]FIG. 8 is a block diagram of a sixth exemplary embodiment of the fieldbus relay arrangement according to the present invention that can be used for PID-step applications.
DETAILED DESCRIPTION
[0030] Preferred embodiments of the present invention and their advantages may be understood by referring to FIGS. 1 - 8 , like numerals being used for like corresponding parts in the various drawings.
[0031] [0031]FIG. 1 shows a first exemplary embodiment of a fieldbus relay arrangement 10 according to the present invention. This exemplary fieldbus relay arrangement 10 includes a main circuit board 20 which has coupled thereto or contains therein certain components such as power supply and signal shaper 30 , a firmware download interface 40 , a flash memory 50 , a random access memory (RAM) 60 , a modem 70 , a factory reset module 80 , as well as a central processing unit (CPU) with electrically erasable programmable read-only memory (EEPROM) 90 . In addition to the main circuit board 20 , the relay arrangement 10 may include a relay apparatus 100 that has an optical isolation circuit 120 and a fuse 130 . Output connectors 160 are provided for connecting a load 140 and a power supply 150 in parallel with the relay arrangement 10 of the present invention for switching purposes in a Foundation® or Profibus® fieldbus network.
[0032] In particular, the control components of the main circuit board 20 are operable to perform various control and communications functions, including storing and modifying certain status variables, executing fieldbus function blocks, communicating with other field devices on the H1 fieldbus network, etc. For example, an executing function block can instruct the CPU 90 to control the switching operation in the relay apparatus 100 , thus affecting the outputs 160 and the load 140 in an output circuit.
[0033] [0033]FIG. 2 shows a block diagram of a second exemplary embodiment of the fieldbus relay arrangement 200 according to the present invention. In this exemplary embodiment, the output circuit can include two separate relay outputs. For example, the fieldbus interface 210 can connect the fieldbus relay arrangement 200 to the fieldbus network. The output circuit may include two or more optical isolation circuits 120 and two or more fuses 130 , each connected in parallel with the respective loads 140 and power supplies 150 via the respective output connectors 160 of the relay arrangement of the present invention for executing the switching operations. It should be understood by those skilled in the art that power supply 150 can be either an A.C. or D.C. power supply.
[0034] [0034]FIG. 3 shows a front view of a third exemplary embodiment of the fieldbus relay arrangement 300 according to the present invention which may include a plurality of exterior electrical connectors. An external power supply may be connected to power supply terminals 310 so as to provide power for the exemplary relay arrangement 300 . Communication terminals 330 may be used for coupling the relay arrangement 300 to the fieldbus networks to, e.g., communicate with other field devices on the Foundation® or Profibus® fieldbus network. Relay output terminals 340 and 350 can be provided as discrete outputs, and may facilitate a switching functionality from the respective relays of the relay arrangement 300 .
[0035] [0035]FIG. 4 illustrates an exemplary portion of any one of the fieldbus relay arrangements of FIGS. 1 - 3 as integrated into an exemplary fieldbus network 420 (e.g., the Foundation® or Profibus® fieldbus networks). A computer 410 may be coupled to the fieldbus network 420 for configuring and controlling fieldbus field devices 430 attached thereto. The exemplary fieldbus relay arrangement 100 , 200 , or 300 can be coupled to the fieldbus network 420 . An output circuit 440 of Fieldbus relay arrangement 200 may include two or more loads connected to a power supply. The fieldbus relay arrangement of FIG. 4 may communicate with the fieldbus network 420 in the same manner as any other field device 430 . Also, in accordance with the execution results of the function blocks, this fieldbus relay arrangement can switch the relays 200 connected at the output circuit 440 .
[0036] [0036]FIG. 5 shows another exemplary embodiment of one or more fieldbus relay arrangements 560 according to the present invention, which is illustrated as being integrated into an exemplary fieldbus process control scheme 500 . In this scheme 500 , a power supply 510 can be utilized to provide power to the fieldbus network. Interface devices or cards 530 may be installed into or connected to a computer (e.g., personal computer, server, etc.), and facilitate the control and configuration of the fieldbus network and devices situated thereon using a software configuration program (e.g., Smar Research's Syscon software). Trunks 540 and spurs 550 may be used to interconnect segments of the fieldbus network and a plurality of devices, and junction boxes 520 can provide junctions for the branches in the fieldbus network. The exemplary fieldbus relay arrangements 560 are coupled to the fieldbus network via the spurs 550 , which may provide power to the relay arrangements and communications with the other field devices attached to the fieldbus network. In addition, these fieldbus relay arrangements 560 may execute the function blocks in accordance with the configuration set forth in the Foundation® or Profibus® fieldbus specification. Also, the function blocks can direct the fieldbus relay arrangements 560 to switch their outputs to control the conventional discrete process control devices 570 . In one example, the process control devices 570 may be used to monitor and control the flow of a liquid through a conduit 580 attached thereto.
[0037] [0037]FIG. 6 shows a block diagram of an exemplary embodiment of a fieldbus control system 600 according to the present invention. This control system includes the computer 410 which is used to monitor, control and configure a fieldbus network 660 (e.g., the fieldbus network). As provided in this exemplary embodiment, a fieldbus relay arrangement 610 includes a discrete output (DO) function block 650 . This fieldbus relay arrangement 610 may execute the instructions of the function block 650 , and communicate data such as an output value and status variable (corresponding with such execution) to a relay apparatus 630 , which may, in turn, switch the relay output to, e.g., enable or disable an alarm signal lamp 620 in response to a particular condition.
[0038] [0038]FIG. 7 illustrates another exemplary embodiment of a fieldbus relay arrangement 700 for an alarm detection according to the present invention which is connected to a fieldbus network 770 and to a pressure sensor fieldbus device 780 . In particular, the pressure sensing fieldbus device 780 may include a transducer (“TRD”) function block 785 and an analog input (“AI”) function block 790 . This pressure sensing fieldbus device 780 may be used to monitor a pressure level 795 , and may transmit a signal 760 to the fieldbus relay arrangement 700 when a particular predetermined alarm condition occurs. The signal 760 can be received by an alarm function block 750 which can send an output signal to a discrete output (DO) function block 740 . The DO function block 740 can transmit a signal to a transducer block 730 which is coupled to an output 720 of the fieldbus relay arrangement 700 . An alarm signal lamp 710 can be connected to the output 720 of the fieldbus relay arrangement 700 , and may be illuminated due to the occurrence of the predefined alarm condition. Numerous other discrete devices may be used instead of or in addition to the alarm signal lamp 710 , as would be understood by those skilled in the art.
[0039] Referring to a block diagram of FIG. 8, another exemplary embodiment of the fieldbus relay arrangement of the present invention is illustrated, which may be used when, e.g., a final control element has an actuator that can be driven by an electric motor with an actual position feedback. The final control element may be positioned by rotating the motor clockwise or counter-clockwise. This positioning may be accomplished by activating a discrete signal of the motor for each direction. For example, a control valve may use one control signal to open and another control signal to close itself. Also, when no signal is applied, the valve may be configured to maintain its current position. The exemplary embodiment of the fieldbus relay arrangement 800 of FIG. 8 includes two discrete relay outputs 850 , and thus can be utilized to implement such exemplary operation. A proportional/Integral/Derivative (PID) Step control block 810 may provide an output 820 to a transducer block (TRD) 830 . This transducer block 830 may be used to convert the control signal into a form suitable for controlling the motor which is connected to relay outputs 850 of a relay module 840 of the fieldbus relay arrangement 800 .
[0040] The exemplary embodiments of the fieldbus relay arrangements of the present invention can be used in a variety of process control applications which are not necessarily related to manufacturing processes. For example, the relay arrangement may be utilized for a building automation process and operation. In particular, such arrangement may be used to control the opening and closing of solenoid valves for water and gas control in an apartment building, in a manner similar to that described above with reference to the relay arrangement of FIG. 5 for controlling a flow of a liquid. A variety of other building automation applications could be used as is apparent to those with ordinary skill in the art.
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An arrangement operable to communicate with a fieldbus network and operate an attached relay and a method for implementing such arrangement is provided. The arrangement and method provide conventional discrete outputs from a fieldbus device using standard fieldbus function blocks, such as those used for Foundation® and Profibus® fieldbus networks. The arrangement and method may facilitate the integration of traditional discrete relay functions into these more advanced digital fieldbus networks, and also utilize additional functions available to standard Foundation® fieldbus and Profibus® fieldbus network devices.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for fabricating semiconductor devices wherein extremely high precision on the location of device components is maintained.
2. Development of the Invention
In current large scale integration (LSI) processing techniques for forming, e.g., bipolar transistors, emitter and isolation formation is performed using two separate photolithographic steps. In electron beam lithography, for example, to maintain a 1 micron space between device components, an inherent alignment error of ±0.4 microns with respect to electron beam alignment marks exists with current state of the art technology. Thus, when two alignments are performed, for example one for emitter alignment and one for isolation alignment, a potential error of as great as 0.8 microns can occur. Using current photolithographic techniques, 1.5μ spacings can be obtained with an alignment error of ±0.6μ. In such a situation, using current state of the art technology, the possibility thus exists that the emitter-base junction and isolation will be too close or, alternatively, one or more of these device elements will overlap with one or more other device elements, leading to poor device performance. A further problem is that if the emitter-base junction and isolation are extremely close, i.e., there is high alignment error, high mechanical stresses present near the isolation region after high temperature heat treatments can impact on device performance.
The above situation is illustrated in simplified form in FIG. 1 where substrate 1 is provided with electron beam registration marks 10 and 11 and there is shown emitter 20 and isolation trench 21 in perfect alignment as illustrated by the solid line; however, as illustrated by the broken lines, if emitter 20 is misaligned 0.4 microns to the right and isolation trench 21 is misaligned 0.4 microns to the left, the space separating these two device elements is only 0.2 microns.
U.S. Pat. No. 4,131,497 Feng et al discloses a method of manufacturing self-aligned semiconductor devices. However, in Feng et al there is no isolation/base alignment or emitter alignment as per the present invention; further, emitter size can vary substantially without accurate control, a factor in distinction to the present invention.
U.S. Pat. No. 4,135,954 Chang et al discloses a method for fabricating self-aligned semiconductor devices utilizing selectively etchable masking layers. However, according to the procedure of Chang et al, there is no self-alignment of the emitter and base or alignment with respect to the isolation.
U.S. Pat. No. 4,160,991 Anantha et al discloses a high performance bipolar device and a method for making the same. As with the preceding references, Anantha et al does not disclose a process which would permit isolation/emitter self-alignment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-17 schematically illustrate a processing sequence in accordance with the present invention.
FIG. 18 is a schematic upper view illustrating the self-alignment feature of the present invention.
The Figures, of course, merely illustrate one small greatly enlarged portion of a silicon body which will be used to form a very dense bipolar integrated circuit and are not drawn to scale.
SUMMARY OF THE INVENTION
The present invention provides a process for manufacturing high density integrated circuits where transistor emitter-base isolation distances are established with high precision and, if there is any misalignment during photolithographic procedures, such misalignment occurs in a wide dielectric isolation without adverse impact on transistor performance.
The present invention provides a process which comprises:
(a) producing an ion-implantation resistant island on a substrate;
(b) growing ion-implantation resistant sidewalls on the island;
(c) implanting a first impurity;
(d) removing the sidewalls;
(e) implanting a second impurity where the sidewalls were;
(f) growing a conformal etchable coating over the surface of the device;
(g) masking to define an area spaced from and exterior to the area where the sidewalls were;
(h) removing the conformal etchable coating in the area of step (g);
(i) etching a deep trench in the area where the conformal coating was removed;
(j) implanting a third impurity into the deep trench.
Following island removal, the emitter and base of a bipolar transistor are formed in the area where the island existed.
In a preferred embodiment, trenches of various depths are etched into the substrate and filled with a dielectric isolation material.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For brevity, the following abbreviations are used in the followng discussion and in the Figures:
Polysi--polysilicon layer
SiO 2 --silicon dioxide
Si 3 N 4 --silicon nitride
RIE--conventional reactive ion etching
CVD SiO 2 --SiO 2 formed by conventional chemical vapor deposition.
In the following, like numerals denote like elements, though the drawings are not to scale.
While in the following doping is typically by ion implantation, it will be appreciated by one skilled in the art that either thermal diffusion or ion implantation can be used.
Reactive ion etching as is utilized in the present invention is described in detail in "A Survey of Plasma-Etching Processes" by Richard L. Bersin, published in Solid State Technology, May 1976, pages 31-36 in great detail. As will be appreciated by one skilled in the art, the atmospheres utilized for RIE will vary greatly depending upon the material being etched, and the Bersin article describes such in detail and is incorporated herein by reference. See also "Reactive Ion Etching in Chorinated Plasma" by Geraldine C. Schwartz et al, Solid State Technology, November 1980, pp. 85-91, also incorporated by reference.
Finally, while in the following certain specific P - type and N - type impurities are utilized for illustrative purposes, it will be appreciated by one skilled in the art that these are selected solely for illustrative purposes and other equivalent P - type and N - impurities can be used with equal success.
In the following disclosure, various layers are formed or removed. Unless otherwise indicated, the layers are formed or removed at the following conditions; where layer thicknesses vary, the processing time is merely increased or shortened to obtain or remove thicker or thinner layers, respectively.
Illustrative conditions used to form or remove various layers, illustrative implantation conditions, thermal oxidation conditions and photoresists are set forth below, all of which are conventional unless otherwise indicated. The disclosure below applies in general to the following processing scheme, but it will be apparent to one skilled in the art that other conditions and techniques can be used to achieve the desired result.
For instance, the epi layer is typically formed at 1,000° to 1,200° C. by deposition from an SiCl 4 /H 2 atmosphere; or SiH 4 /H 2 mixture; the epi layer is removed at room temperature by RIE etching in SF 6 , CCl 4 or Cl-Ar mixture at room temperature.
Polysi layers are typically formed by CVD in a silane-argon atmosphere at 625° C.
Si 3 N 4 is typically grown from a silane-ammonia atmosphere at 800° C.
SiO 2 can be grown by wet oxidation in steam at temperatures below 1000° C. or by CVD at low pressure, e.g., 500˜700 millitorr and low temperatures, e.g., 400°˜550° C. in a silane --O 2 atmosphere or at high temperatures, e.g., 700°˜900° C. in a dichlorosilane atmosphere.
The photoresists used include conventional photoresists such as Shipley AZ 1350J which is commercially available from Shipley Co. and developable in a KOH solution. Such can be masked, exposed and developed in a conventional manner. Photoresists capable of fine resolution are preferred. Photoresists can be stripped in an O 2 plasma etch.
The above article by Bersin, of course, describes useful RIE techniques. Typically, RIE or directional etches are conducted as follows;
For SiO 2 in CF 4 -H 2 at room temperature; see also L. Ephrath, Abstracts of the Electrochemical Society No. 135, Vol. 77-2, Fall Meeting, Atlanta, Ga., Oct. 9-14, 1977 and U.S. Pat. No. 3,940,506 Heinecke, both incorporated by reference;
For Si 3 N 4 in CF 4 --H 2 at room temperature; and
For polysi in SF 6 of Cl 2 /Ar mixtures or in CBrF 3 at room temperature. Electrochemical Society Meeting, Los Angeles, California, 14-19, 1979, extended Abstracts, Vol. 79-2, pp 1424-1525 describes the SF 6 RIE of polysilicon in some detail and such is incorporated by reference.
Si 3 N 4 can also be removed by a wet etch in hot phosphoric acid at 160° to 180° C. and CVD SiO 2 can also be removed in buffered HF at room temperature.
Finally, boron implantation and arsenic implantations are typically conducted at 5 KeV for boron to a concentration of 2×10 14 atoms/cm 2 and for arsenic at 30 KeV to a concentration of about 2×10 15 /cm 2 .
Using the various etches above disclosed, generally an etch ratio on the order of 6˜10:1, more typically 8:1, is obtained between polysi as compared to Si on SiO 2 using SF 6 RIE or CBrF 3 RIE and 6:1 using Cl 2 /Ar RIE. In a similar fashion, an etch ratio on the order to 15:1˜20:1 is obtained for SiO 2 or Si 3 N 4 as compared to Si or polysi with CF 4 --H 2 RIE. Finally, O 2 plasma etching permits the rapid removal of photoresist and polyimide but does not affect SiO 2 , Si 3 N 4 , etc.
In the processing scheme to be described, generally thickness and etching tolerances of plus or minus 10% are achieved.
With reference to FIG. 2, there is shown therein substrate 10. The substrate is typically a <100> monocrystalline silicon wafer having a resistance on the order of 10 to 20 ohm-cm. Substrate 10 carries a conventional N epi layer 11 formed as above to a thickness of about 1 micron, 1,000 A polysi layer 12 formed by CVD silane-argon deposition (which layer is undoped), 300 A Si 3 N 4 13 formed by silane/ammonia deposition, 2,500 A polysi layer 14 formed by a CVD silane-argon process (undoped), and what may be viewed as an "emitter island" 18 on polysi layer 14 comprising 1,000 A Si 3 N 4 layer 15, 10,000-12,000 ACVD Si 2 O layer 16 (which is doped, for reasons later explained) and 1,000-1,500 A polysi layer 17.
For purposes of simplicity, not shown in FIG. 2 or in subsequent Figures relating thereto is a conventional N + subcollector which is formed by ion implantation of arsenic at 50 KeV and a dose of 1.5×10 16 atoms/cm 2 into substrate 10. During the epitaxial deposition process, which is a high temperature process, the subcollector region (not shown) will diffuse, but this effect is well known and the effect of such diffusion can be accurately predicted by one skilled in the art.
While not illustrated, the "island" 18 comprising layers 15, 16 and 17 as shown in FIG. 2 is formed as follows.
Beginning with a structure formed as shown in FIG. 2 up to and including 2,500 A polysi layer 14, firstly an Si 3 N 4 layer about 1,000 A thick is deposited over the complete surface of polysi layer 14 by silane/ammonia deposition. After further processing as below, this will yield layer 15 of island 18.
Nextly, a CVD SiO 2 layer about 10,000-12,000 A thick is grown on the 1,000 A thick Si 3 N 4 layer by a conventional CVD silane/argon process. This CVD SiO 2 layer is doped with germanium or boron to a concentration on the order of 2.5×10 21 atoms/cc by the addition of, for example, GeH 4 . See Abe et al, Supplement to the Journal of the Japan Society of Applied Physics, Vol. 39, 1970, p. 88-93. Boron provides a similar effect; Schwenker, J. Electrochem. Soc.; Solid State Science, Vol. 118, No. 2, February 1971, p. 313-317. After processing as below, the remainder of this layer will form that portion of island 18 represented by CVD SiO 2 layer 16.
Following the above procedure, a layer of polysi approximately 1,200 A thick is grown on the CVD SiO 2 layer 16. After processing as below, the 1,100 A remainder of this layer will provide polysi layer 17 in island 18.
After the above procedure, a 300 A thick Si 3 N 4 layer is grown on the 1,200 A polysi layer by silane/ammonia deposition. This Si 3 N 4 layer serves as a temporary mask and will not be present in the device as shown at the stage of FIG. 2.
Thereafter, Shipley AZ 1350 J is applied to the uppermost Si 3 N 4 layer, and the same is masked, exposed and developed (removed) where the island 18 is to be formed.
After the removal of the photoresist over the island location, the 300 A Si 3 N 4 layer directly thereunder is removed in the island location by RIE etch in CF 4 H 2 at room temperature; alternatively, a wet etch in hot phosphoric acid can be used, but this is not preferred.
By the above procedure, the 1,200 A polysi layer which will yield layer 17 of island 18 is exposed.
The photoresist is next removed in a conventional manner by an O 2 plasma etch and thereafter a 250 A thick thermal SiO 2 layer is formed by wet oxidation of the surface of the 1,200 A polysi layer which will form layer 17 of island 18; approximately 100 A of the polysi is converted to 250 A of SiO 2 . No other areas of the device at this stage except the island area are affected since they are masked by the 300 A Si 3 N 4 layer.
Following the above procedure, the 300 A Si 3 N 4 layer is removed by etching in hot phosphoric acid; the 250 A thick SiO 2 layer grown by wet oxidation of the 1,200 A polysi layer which will yield layer 17 in island 18 is not effected by this etch; following the above etch, the 1,200 A polysi layer which will yield layer 17 of island 18 is exposed in all areas except at the island area which is, of course, protected by the 250 A thick SiO 2 "mask".
Thereafter, RIE etching in SF 6 is conducted to remove the 1,200 A polysi layer which will yield layer 17 of island 18 in all areas except the area where the island is to be formed which is, of course, protected by the 250 A SiO 2 "mask". Following this procedure, at all areas other than the island area, the 10,000 to 12,000 A CVD SiO 2 layer which will form layer 16 of island 18 is exposed.
This CVD SiO 2 layer is removed at all areas outside the island area by RIE etching of the CVD SiO 2 layer in CF 4 --H 2 which exposes the underlying Si 3 N 4 layer which will yield layer 15 of island 18, which is thereafter removed at areas outside the island area by RIE etching in CF 4 --H 2 .
The 250 A SiO 2 mask on top of 1,200 A polysi layer 17 is also removed during the conventional CF 4 --H 2 RIE etch which removes the 10,000 to 12,000 A CVD SiO 2 layer, whereby a structure as shown in FIG. 2 results.
As will be appreciated by one skilled in the art, viewed from above island 18 will have a square or rectangular shape. Thus, while the following explanation is generally given for cross-sectional views, it should be kept in mind that the processing steps exemplified also generally affect the areas of island 18 in the plane perpendicular the drawings.
It is to be specifically noted that the combination of thin Si 3 N 4 layer 15 and doped CVD layer SiO 2 16 provides unique benefits in that stresses during processing are reduced. If Si 3 N 4 layer 15 and CVD SiO 2 layer 16 were replaced by a single Si 3 N 4 layer, substantial edge stresses might be introduced during processing.
With reference to FIG. 3, following the above procedure 300 A polysi layer 19, 500 A Si 3 N 4 layer 20 and 5,000 A CVD SiO 2 layer 21 are grown using the procedures above described over the entire surface of the device. Each of these coatings are conformal and, of course, cover polysi layer 14 and island 18. The purpose of these layers is basically to protect the sidewall of island 18.
With reference to FIG. 4, firstly CVD SiO 2 layer 21 and then Si 3 N 4 layer 20 are etched using a conventional RIE directional etch in CF 4 --H 2 , whereby all horizontal surfaces of CVD SiO 2 layer 21 and Si 3 N 4 layer 20 are removed, leaving sidewall CVD SiO 2 zones 21a and 21b and sidewall Si 3 N 4 zones 20a and 20b; since the directional etch does slightly erode the corners of the CVD SiO 2 layer 21, an arcuate shape is shown for CVD SiO 2 zones 21a and 21b. This directional etch results in an exposure of polysi layer 19 at all areas except the areas protected by CVD SiO 2 zones 21a and 21b and Si 3 N 4 zones 20a and 20b. Polysi layer 19 remains for reasons which will later be apparent.
Following the above processing, a photoresist (Shipley AZ 1350J) is applied and the same is masked, exposed and developed (removed) in a conventional manner where the P + contact 22 is formed. The photoalignment thereof is non-critical and serves as a means to prevent P + doping on the collector contact area 103 shown in FIG. 18.
Following the above, a conventional boron implantation, e.g., at 90 to 100 Kev, dose: 5×10 15 atoms/cc, is conducted to yield P + contact 22 in all areas except the area indicated by numeral 23 which is protected by CVD SiO 2 zones 21a and 21b (and Si 3 N 4 sidewalls 20a and 20b), island 18 and the collector contact area 103 shown in FIG. 18. In this regard, the protected areas under the CVD SiO 2 zones and Si 3 N 4 sidewalls are shown as 23a and 23b. Elements 23, 23a and 23b are shown only in FIG. 4 for purposes of explanation.
In the areas under CVD SiO 2 zones 21a and 21b the base access area of the bipolar transistor will eventually be formed and CVD SiO 2 zones 21a and 21b serve the primary purpose of protecting this area from high concentration boron implantation. In distinction, in other areas a heavy boron dope is conducted since this will ensure good electrical contact with the base contact (shown in FIG. 18). Island 18 comprising layers 15, 16 and 17 is, of course, sufficiently thick to prevent boron implantation into the area directly thereunder.
Following the above procedure, as illustrated in FIG. 5, firstly CVD SiO 2 zones 21a and 21b are removed using buffered HF in a conventional fashion, permitting Si 3 N 4 sidewalls 20a and 20b to remain; the remainder of the device is not affected by the HF. Thereafter, polysi layers 14 and 19 are thermally oxidized at about 900° C. to form a thermal SiO 2 layer about 600 A thick (which is inert to hot phosphoric acid) at all areas of the device except those areas protected by Si 3 N 4 sidewalls 20a and 20b; the thermal SiO 2 is illustrated in FIG. 5 by numeral 24.
The device is then processed to have the configuration shown in FIG. 6 as follows.
Firstly, the unprotected Si 3 N 4 sidewalls 20a and 20b are removed in hot phosphoric acid, exposing the areas in FIG. 6 identified as 25a and 25b. This etch does not substantially affect thermal SiO 2 layer 24 covering polysi layer 14 and polysi layer 17.
Next, at areas 25a and 25b which are not protected by thermal SiO 2 layer 24, directional etching is conducted, e.g., RIE in SF 6 of polysi layers 19 and 14 is first conducted whereafter Si 3 N 4 layer 13 is removed in hot phosphoric acid at areas 25a and 25 and then polysi layer 12 is removed by RIE in SF 6 .
Following the above procedure, a low dose 5 KeV boron implant is conducted in a conventional fashion to a concentration of 5×10 11 to 5×10 12 atoms/cc at areas 25a and 25b to result in P - zones being formed in N - epi layer 11, as identified by numerals 26a and 26b. Thermal SiO 2 layer 24 and polysi layer 14 prevent boron implantation into the balance of the device.
The RIE which provides the device illustrated in FIG. 6 where thermal SiO 2 layer 24 is used as a mask provides an essentially self-aligned base structure, as will later be apparent, without the use of a photolithographic step which can introduce the inaccuracy heretofore discussed.
In this regard, if reference is made to FIG. 3 and FIG. 4, it is seen that CVD SiO 2 layer 21 is formed in a conventional fashion; the thickness of such a layer upon deposition can be controlled in a highly precise manner using conventional techniques in the art, as can the thickness of Si 3 N 4 layer 20.
In a similar fashion, the degree of etching or degree of CVD SiO 2 and Si 3 N 4 removal which leads to the device as shown in FIG. 4 can be easily controlled in a highly reproducible fashion, i.e., the exact location of areas 22 and 23 as shown in FIG. 4 can be easily controlled by conventional deposition/etching techniques.
Thus, since thermal SiO 2 layer 24 directly abuts Si 3 N 4 sidewalls 20a and 20b as shown in FIG. 5, when the diffusion of P - pockets 26a and 26b shown in FIG. 6 is accomplished, extremely precise location of P - pockets 26a and 26b is obtained without the need for photolithographic alignment.
For example, if one was to form P - pockets twice as wide as those represented by 26a and 26b in FIG. 6, instead of using a 5,000 A CVD SiO 2 layer 21, a 10,000 A CVD SiO 2 layer would be used which, upon etching, would provide CVD SiO 2 areas 21a and 21b as shown in FIG. 4 and, of course, Si 3 N 4 sidewalls 20a and 20b as shown in FIG. 4, essentially twice as wide as shown in FIG. 4.
Thus, by following the procedure of FIGS. 1-6, a device as shown in FIG. 6 is obtained having P - diffusions placed in a highly accurate fashion which will eventually delineate the emitter-base region of a bipolar transistor.
Following the procedure of FIG. 6, a low pressure CVD SiO 2 oxide deposition is conducted over the entire surface of the device to grow CVD SiO 2 oxide layer 30 as shown in FIG. 7. For purposes of simplicity, since there is no difference of substance in characteristics between layer 30 and layer 24, these are merely shown as merged into layer 30 in FIG. 7. The total thickness of CVD SiO 2 layer 30 is approximately 8,000-10,000 A, and this will result in a second inherently self-aligning procedure as now will be explained.
Referring to FIG. 7, which shows the device after growth of the CVD oxide layer 30, it is to be specifically noted that since CVD oxide layer 30 is conformal and dimension 32 exceeds dimension 31, i.e., exceeds the dimension of the gap which has been etched to the N - epi layer 11 at areas 25a and 25b shown in FIG. 6. It is necessary that CVD SiO 2 layer 30 extend a distance 32 which is greater than distance 31. This is a critical aspect of the present invention since the difference between dimension 32 and 31 as represented by numeral 33 in FIG. 7 will eventually be the area of formation of a P - isolation ring of high placement accuracy around the base and emitter of a bipolar transistor.
Since dimension 33 will typically be on the order of, e.g., 0.35 to 0.55 micron, even if there is a slight error in the isolation placement, the device cannot be adversely effected since dimension 32 is greater than dimension 31, and with the accurate control inherent in CVD SiO 2 deposition, dimension 33 can be freely selected in a highly accurate fashion to insure that the emitter and base of the bipolar transistor will not be contacting the isolation, even if a photolithographic step is used at this stage of the process of the present invention. Thus, any misalignment will be shifted from the emitter area where placement is critical, to the isolation area where placement is relatively non-critical.
As shown in FIG. 7, nextly a conventional photoresist such as Shipley AZ 1350 J is applied to CVD SiO 2 layer 30 and masked, exposed and developed in a conventional manner to provide annular, rectangular photoresist protected areas as represented by numerals 35a, 35b and 35c in FIG. 7. Of course, it is desired that masking, exposure, etc., be as precise as possible, though misalignment within alignment tolerance is acceptable.
As can be seen from FIG. 7, in the area represented by numeral 32a the depth of the CVD SiO 2 layer 30 is very thick; thus, when RIE is conducted, areas protected by photoresist as represented by 35a, 35b and 35c will not be etched and due to the greater thickness of the oxide at 32a etching will not be complete at this area, rather, etching will proceed down to poly layer 14 only at areas 36a and 36b as indicated by the arrows in FIG. 7. The P + doping which was introduced by implantation at areas 36a and 36b after island delineation as shown in FIG. 7 is important in that it provides low resistance base access to the device.
With respect to FIG. 7, CVD SiO 2 layer 30 is nextly subjected to RIE in CF 4 --H 2 and CVD SiO 2 layer 30 is thus etched at all areas except those areas protected by photoresist 35a, 35b and 35c but is not completely etched in those areas where CVD SiO 2 layer 30 has thickness 32a, leaving, as shown in FIG. 8, CVD SiO 2 area 30c and 30d under photoresist layers 35a and 35c, respectively, and CVD SiO 2 areas 30a and 30b which have a depth of about 15,000 A, dimensions 31 and 33 being, respectively about 0.5μ and 0.3μ, of course, since the RIE does not substantially affect these dimensions. From above, the photoresist layout resembles a central "castle" 35b surrounded by a "moat"--38a and 38b with complementary areas behind and in front of the plane of FIG. 8--which is bounded by photoresist 35a and 35c--again with complimentary areas behind and in front of the plane of FIG. 8.
It is to be specifically noted that following the above procedure areas 38a and 38b are formed where the polysi layer 14 is exposed as shown in FIG. 8.
It can be seen that since dimension 33 as shown in FIG. 8 can be accurately controlled by the combination of CVD and RIE, that if there is any error in the photoresist step which results in the formation of photoresist areas 35a, 35b and 35c that nonetheless, as will later be clear, the location of the base and emitter of the transistor will not be affected, rather, if there is any error it will be in the area where the deep trenches will be formed as will later be explained for FIG. 9.
If any misalignment during photoresist exposure occurs, in the above procedure, this will occur at the area indicated by Δ in FIG. 8 (obviously the Δ can occur at the other side of island 18 but the effect of shifting much misalignment into one deep trench or the other is the same). Assuming such misalignment occurs, then during removal of CVD SiO 2 layer 30 the only result will be a partial etch into polysi layer 17 as shown at the Δ area in FIG. 8 with a corresponding shift of deep trench 47b shown in FIG. 9 a corresponding Δ measurement. This concept, central to the invention, is illustrated in more detail in FIG. 18. Obviously the thickness of polysi layer 17 must thus be correlated with etch conditions, but such can easily be done by one skilled in the art given the illustrative values above.
Note also that if theoretical deep trench width is represented by "1", deep trench width 47a in FIG. 9 would be "1" plus Δ minus the sum of the P + and P - ring spacings but deep trench 47b shown in FIG. 9 would have a width of "1" minus Δ minus the sum of the P + and P - ring spacings.
Referring now to FIG. 9, following the above procedure firstly photoresist is removed by, e.g., O 2 plasma etch, whereafter deep trench formation is conducted in the unprotected areas between CVD SiO 2 depositions 30a, 30b, 30c and 30d whereafter deep trenches 47a and 47b result. For example, polysi layer 14 is removed by RIE in SF 6 , Si 3 N 4 layer 13 is removed in hot phosphoric acid, polysi layer 12 is removed by RIE in SF 6 and 4μ of the silicon thereunder removed by the same procedure, all in a conventional fashion.
Nextly, oxide layer 27 (500˜1,000 A) is thermally grown at 1000° C. in O 2 and steam on exosed polysi and silicon to mask against sideward boron implantation. Then deep trench boron implantation, as shown by the arrows in FIG. 9, is conducted to form P isolation pockets 44 and 46 in P - substrate 10, e.g., using a conventional ion implanter at 5˜30 KeV to provide a boron concentration of 10 13 to 5×10 15 atoms/cc. P isolation pockets 44 and 46 ensure the N epi layer 11 is appropriately isolated.
Referring now to FIG. 10, a 4,000 to 5,000 A SiO 2 layer 48 is formed over the entire surface of the device by low pressure CVD deposition. Although CVD SiO 2 layers 30a and 30b are shown in FIG. 10 as distinct from layer 48, chemically their identity is similar. CVD SiO 2 layers 30c and 30d are, for simplicity, shown merged with layer 48.
Still referring to FIG. 10, nextly a conventional photoresist such as Shipley AZ 1350 J is applied to the entire surface of the device to provide photoresist layer 50, whereafter the photoresist is masked, exposed and developed in a conventional manner to remove photoresist at the areas where a shallow trench is to be formed, which procedure is explained with respect to FIG. 11. As one skilled in the art will appreciate, the shallow trenches are used for contact--not device--isolation, and thus are typically at a 90° angle to the deep trenches.
As one skilled in the art will further appreciate, FIG. 10 is not to scale since the trenches 47a and 47b are deep wide trenches and will be much wider than shown, e.g., can have a depth on the order of 4 microns and a width of 5 to 10 microns up to 100 microns. Thus, layers 48 and 50 will not actually fill the trenches, rather, will "indent" at the areas of the trenches. This phenomenon is well known in the art, and is thus merely schematically illustrated in FIG. 10.
Referring to FIG. 11, FIG. 11 is a 90° rotation of the device shown in FIG. 10 with the device shown in perspective for clarity. As is illustrated in FIG. 10, FIG. 11 is essentially a perspective view of the device viewed from the direction of the arrows shown in FIG. 10. The P + and P - diffusions around the island shown in earlier Figures are not shown in FIGS. 11-16 and 18 for simplicity.
With respect to FIG. 11, this represents the device after the photoresist layer 50 illustrated in FIG. 10 has been masked, exposed and developed to expose the area over shallow trench 60, whereafter CVD SiO 2 layer 48 is removed in areas not protected by photoresist by CF 4 --H 2 RIE etching, whereafter the photoresist layer is stripped by an O 2 plasma etch. At this stage remaining SiO 2 layer 48 serves as a mask so that polysi layer 14, Si 3 N 4 layer 13, polysi layer 12 and epi layer 11 are removed in unprotected areas using RIE etch procedures as earlier described, whereafter shallow trench 60 is formed to a depth of about 1μ in the substrate 10 using the procedures as earlier explained for deep trench formation, one deep trench 47a being shown in FIG. 11 for purposes of illustration. Shallow trench 60 does not, of course, extend through the subcollector (not shown).
As will be appreciated by one skilled in the art, shallow trench 60 actually connects deep trench 47a and deep trench 47b, deep trench 47b being just forward of the plane of FIG. 11. Also, since shallow trench 60 will extend somewhat into the deep trenches, as exemplified by 47a in FIG. 11, while the deep trenches are typically etched to a depth of about 3.5 microns and the shallow trenches are etched to a depth of about 1.0 micron, the areas where shallow trench 60 overlaps deep trench 47a will be etched to a somewhat greater depth, for example, on the order of a total of 4.5 microns. This causes no problems since a deep trench such as 47a is very wide in the context of overall device measurements.
It is to be specifically noted that doped SiO 2 layer 16 as shown in FIG. 11 serves to protect underlying layers during etching; thus, since no doped SiO 2 layer exists in the area of shallow trench 60, and SiO 2 layer protects the balance of the device, etching is conducted only in the area where shallow trench 60 is to be formed.
Referring now to FIG. 12, FIG. 12 is a front view of the device of FIG. 11 after the processing now to be described. Deep trenches are, of course, not shown since these are out of the plane of FIG. 12, i.e., beyond the drawing on either side. For simplicity, various P + and P - implants as shown in earlier Figures are not identified in FIGS. 12-16 and 18; suffice it to say they remain essentially unchanged except where a subsequent implant occurs or a post-implant anneal is conducted, procedures whose effects will be apparent to one skilled in the art.
Firstly, 3,000˜5,000 A SiO 2 layer 48 which is etched back during the 1μ trench formation by at least 1,200 A as shown in FIG. 11 is removed by a conventional CF 4 --H 2 RIE etch back to leave CVD SiO 2 sidewalls 52, 53 and 54 with a small amount of SiO 2 being formed between sidewalls 53 and 54 in trench 60. As will be appreciated by one skilled in the art, the RIE etch back is a directional etch, and thus while exposed horizontally oriented areas of SiO 2 layer 48 are removed, those areas which present a substantial vertical rise are not substantially etched. The purpose of these sidewalls is to protect the walls on which they are formed.
Following the above CF 4 --H 2 RIE back etch, polysi layer 14 and polysi layer 17 are subjected to a conventional polysi etch; whereas polysi layer 17 is removed, polysi layer 14, due to its greater thickness, is not completely removed. For example, after the removal of polysi layer 17, approximately 1,800 A of polysi layer 14 will remain.
Referring now to FIG. 13, following the above procedure doped SiO 2 layer 16 is removed. Since this SiO 2 layer is doped, the doped SiO 2 layer 16 will be removed at a rate approximately 10 times as fast as undoped SiO 2 present. Thus, doped SiO 2 layer 16 is preferentially etched at 20 A/second. Thus, Si 3 N 4 layer 15 in the emitter island area is exposed. Following the above procedure, the 1,800 A thick layer of polysi 14 is thermally oxidized in a conventional fashion to yield a 600 A layer of thermal SiO 2 56, which of course, will further reduce the thickness of polysi layer 14 to about 1,500 A.
Following the above, now unprotected Si 3 N 4 layer 15 in the emitter island area is removed in hot H 3 PO 4 and now unprotected polysi layer 14 in the emitter island area is removed by a conventional polysi etch, whereafter the device is coated with a conventional photoresist such as Shipley AZ 1350 J and, by a conventional O 2 plasma etch back, photoresist plug 58 shown in FIG. 13 is formed which provides trench protection, i.e., photoresist is etched back in areas other than the trench without a masking step.
It should be noted that the SiO 2 and photoresist as shown in FIG. 13 are essentially impervious to ion implantation, whereas conventional impurities used to form a transistor emitter and base such as boron and arsenic can be driven through the thin Si 3 N 4 layer 13 and poly layer 12 into N epi layer 11; accordingly, following a conventional boron implantation at 5 to 10 KeV to a dose of 2×10 14 atoms/cm 2 , what will be transistor base 70 shown in FIG. 13 results. With a subsequent conventional implantation of aresenic at 30 to 40 KeV to a dose of 2×10 15 atoms/cc, transistor emitter 72 as shown in FIG. 13 results.
Following processing to obtain a device as shown in FIG. 13, photoresist plug 58 is removed with a stripper and a conventional drive-in heating at 900° C. for 45 minutes in O 2 and 950° C. for 30 minutes in N 2 conducted. The photoresist is removed since it could degrade at drive-in temperatures.
It is to be noted that in accordance with the present invention isolation is formed after emitter-base alignment. This is a valuable feature of the present invention as if isolation is performed before base and emitter formation, as per a typical prior art process, typically high stresses are introduced into the device during such processing, a situation avoided per the present invention.
Following the above procedure, as illustrated with respect to FIG. 14, those areas of polysi layer 14 which remain are thermally oxidized in a conventional manner to provide SiO 2 layer 62 as shown in FIG. 14 which is approximately 2,000-4,000 A thick and which includes SiO 2 layer 56 which is omitted in FIG. 14 for brevity.
Thereafter, unprotected Si 3 N 4 layer 13 is removed in a conventional fashion using hot phosphoric acid, thereby exposing unprotected polysi layer 12. Following the above procedure, a thin Si 3 N 4 layer, on the order of 500 A, is then deposited in a conventional manner to provide layer 64 as shown in FIG. 14. Layer 64 is, of course, conformal.
Still referring to FIG. 14, as illustrated therein a polyimide isolation as represented by numeral 66 can be performed by applying any conventional polyimide material such as Monsanto Skybond then etching back in O 2 plasma at room temperature. It is to be noted that in those instances where device isolation is performed using a polyimide, mechanical stresses near the side wall all are considerably reduced. Further, polyimides have excellent planarization capability, a technique known in the art. Since polyimides have a lower dielectric constant than SiO 2 , device performance is boosted. It should specifically also be noted that polysi layer 12 which remains assists to avoid β degradation by preventing direct metallurgy contact with the silicon emitter.
In a further embodiment, the device of FIG. 13 is processed to the stage illustrated in FIG. 14 just prior to polyimide isolation; instead of polyimide isolation, after Si 3 N 4 layer 64 is formed, nextly polysi layer 68 as shown in FIG. 15 is formed by CVD from a silane-argon atmosphere to a thickness of 1,000 A, whereafter CVD SiO 2 or spin-on glass isolation 66a is formed in a conventional manner in the shallow trench and deep trenches. As one skilled in the art will appreciate, of course, since CVD SiO 2 or spin-on glass will be coated over the entire surface of the device, in essence the CVD SiO 2 or spin-on glass in areas other than the shallow trench and deep trench will be removed by a conventional timed CF 4 --H 2 etch back.
The purpose of polysi layer 12 in the emitter island area during the above processing steps is, of course, to protect the polysi emitter 72 shown in FIG. 13 et seq.
Referring now to FIG. 16, which is used for simplicity to illustrate a further processing of the embodiments of FIGS. 14 and 15, and taking FIG. 14 and processing the same to FIG. 16, the next step is to remove the horizontal areas of Si 3 N 4 layer 64 by a conventional timed CF 4 --H 2 RIE, thereby leaving only Si 3 N 4 sidewalls 74 as shown in FIG. 16 with a slight amount of Si 3 N 4 joining the sidewalls.
The embodiment of FIG. 15 would be processed in a similar fashion except that first polysi layer 68 would be removed by a Cl 2 /Ar RIE etch with the ends of the polysilicon at the trench sidewalls being thermally oxidized, whereafter Si 3 N 4 layer 64 would be removed by a conventional timed CF 4 --H 2 RIE at the conditions earlier given, resulting in a device identical to that shown in FIG. 16 except that a thin sidewall of polysi would overlie Si 3 N 4 sidewalls 74 where such sidewalls are present.
Again continuing with the explanation of the invention as given with respect to FIG. 16, and keeping in mind that if the embodiment of FIG. 15 were processed polysi sidewalls would be present over the Si 3 N 4 sidewalls 74 as shown in FIG. 16, a device as shown in FIG. 17 results.
With respect to FIG. 17, it is to be noted, as will be understood by one skilled in the art, that deep trenches essentially encircle and isolate a device. Thus, with reference with FIG. 17, deep trenches 47a and 47b are not shown since these are, of course, outside the plane of FIG. 17; however, deep trenches 80a and 80b are shown therein. Deep trenches 80a and 80b essentially run at 90° angles to, and intersect, deep trenches 47a and 47b.
Turning to FIG. 17 in detail, like numerals are used therein to identify elements shown in FIGS. 1-16, i.e., substrate 10, N epi 11, poly layer 12, Si 3 N 4 layer 13 and SiO 2 layer 62 and SiO 2 sidewalls 52, 53 and 54. Various P + , p and n + implants are generally shown in FIG. 17 for illustrative purposes.
Also shown in FIG. 17 is N + subcollector 82 which, as earlier indicated, is formed just prior to the formation of N epi layer 11, shallow trench 60 filled with dielectric isolation 84, and deep trenches 80a and 80b filled with a similar dielectric isolation 86a and 86b, respectively. For purposes of simplicity, layers such as Si 3 N 4 layer 74 as illustrated in FIG. 16 are not shown in FIG. 17.
In the device as shown in FIG. 17, the base contact is represented by numeral 88, the emitter contact is represented by numeral 90 and the collector contact is represented by numeral 92.
Referring now to FIG. 18, this is a simplified upper view of a schematic of a typical device as formed per the present invention where various diffusion areas, etc., are omitted for purposes of explanation. However, it is believed that one skilled in the art will easily be able to correlate the concepts illustrated in FIG. 18 with the concepts discussed earlier, albeit the schematic of FIG. 18 omits elements earlier mentioned and adds elements not earlier mentioned (which are conventional) for ease of explanation.
With reference to FIG. 18, the semiconductor surface is generally indicated by numeral 100.
Deep trenches are represented by numerals 101a and 101b in FIG. 18.
Shallow trench 102 is shown in FIG. 18, shallow 102 effecting transistor element isolation as shown.
Also shown in FIG. 18 is a conventional P + contact area 108.
Numeral 104 in FIG. 18 represents a P + isolation ring.
Also shown in FIG. 18 is P - diffusion zone 105.
The emitter base island is represented by 106 in FIG. 18.
As one skilled in the art will appreciate, the P + isolation ring 104 will also extend to area 107 as shown in FIG. 18 with the base contact at location 108. Lying under shallow trench 102 is N - epi collector contact 103.
Certain measurements as reflected by l, y, x and Δ are also shown in FIG. 18.
Viewed from above, measurement Δ reflects the misalignment which might occur during deep trench formation as represented by Δ in FIG. 8. As shown in FIGS. 8 and 18, any misalignment during the photolithographic step will be compensated for by an "offset" of the emitter-base island from the theoretical desired centerline--shown in CL in FIG. 18-into deep trench 101b; however, despite the Δ misalignment, the device (transistor) will always be symmetrical and the emitter/base will never contact the isolation.
Thus, any misalignment of the emitter-base island 106 from the true center line CL in FIG. 18 will be compensated for by deep trench 101b being reduced in width by measurement Δ+x+y on one side and by x+y-Δ on the other side. So long as trench width is greater than Δ, any misalignment per the process of the present invention is thus inherently compensated for.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
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The present invention provides a process which comprises:
(a) producing an ion-implantation resistant island on a substrate;
(b) growing ion-implantation resistant sidewalls on the island;
(c) implanting a first impurity;
(d) removing the sidewalls;
(e) implanting a second impurity where the sidewalls were;
(f) growing a conformal etchable coating over the surface of the device;
(g) masking to define an area spaced from and exterior to the area where the sidewalls were;
(h) removing the conformal etchable coating in the area of step (g);
(i) etching a deep trench in the area where the conformal coating was removed;
(j) implanting a third impurity into the deep trench.
Following island removal, the emitter and base of a bipolar transistor are formed in the area where the island existed.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional of U.S. Ser. No. 11/940,417, filed Nov. 15, 2007 by the same inventors, and claims priority there from. This divisional application contains rewritten claims to the restricted-out subject matter of original claims.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is generally related to a biochip, and more particularly to a biochip with a three-dimensional structure and a method for forming the same.
[0004] 2. Description of the Prior Art
[0005] At present, the biochip detection technology becomes increasingly important in biotechnology. The biochip detection technology can simultaneously detect various pathogens on a single chip and break the detection limitation achieved by traditional technologies. A microarrayed biochip is generally prepared by aligning a large quantity of bio-probes (DNA's or proteins) on a chip substrate and is used for analyzing or testing samples by the hybridization of DNA-DNA or specific binding between proteins. According to the detection objectives, there are two major categories for microarrayed biochips: DNA chip and protein chip. DNA chips use nucleotide molecules as the probes to detect their nucleotide fragments. DNA chips can also be categorized into complimentary DNA (cDNA) chips and oligonucleotide chips, according to the length of the probes spotted on chips. cDNA chips are often used in the research of gene expressions; while oligonucleotide chips can also be used in diagnosis of pathogen and genotyping in addition to gene expression analysis.
[0006] For DNA chips, probes are immobilized on substrates and used to detect specific DNA fragments by the characteristic hybridization with complimentary DNA's. DNA chips can be applied on disease detection and shorten the time for developing new medicines. DNA chip is also a powerful tool for analyzing DNA's by appropriate dye labeling in visible emission lights. By different emission wavelengths, individual target DNA can be distinguished and analyzed.
[0007] The application of biochip is vary wide, including gene expression profiling, toxicology analysis, gene sequencing, SNP identification, forensics, immunoassays, protein chip, combat biowarfare, drug screening, hard drives and microprocessors.
[0008] The improvement of detection sensitivity by modifying the substrate surfaces of traditional biochips is currently still being sought to obtain amplified signals to facilitate further analysis. Thus, a novel biochip preparation method is proposed to achieve the high-sensitivity performance.
SUMMARY OF THE INVENTION
[0009] In accordance with the present invention, a biochip with a three-dimensional mesoporous layer and a method for forming the same are provided.
[0010] The three-dimensional mesoporous material is a network polymer with nano-scaled pores, such as aerogel material. Its porosity can be as high as 95%. Due to its high porosity, it possesses a variety of characteristics: high specific surface area, low density, low heat conductivity, low sound spreading speed, low dielectric constant, and so forth. Therefore, it can be applied in various fields, such as heat insulation, catalyst, adsorbent, electrodes, electronics, detectors, etc.
[0011] The first objective of the present invention is to synthesize materials on the top of a flat substrate to form a three-dimensional mesoporous layer using the sol-gel technique.
[0012] The second objective of the present invention is to utilize the large three-dimensional inner specific surface area to recognize labeled DNAs, proteins, peptides, saccharides, and cells. Thus, the biochip with a three-dimensional mesoporous layer according to the present invention has the characteristics of high sensitivity of detection so as it would have a potential to simplify the detection equipments. For example, only data type camera (CCD) would be required instead of complicated imaging technique. Therefore, this present invention does have the economic potential for industrial applications.
[0013] Accordingly, the present invention discloses a biochip comprising a substrate and a three-dimensional mesoporous layer on top of the substrate. The surface of the three-dimensional mesoporous layer is chemically modified to recognize labeled DNAs, proteins, peptides, saccharides, and cells. In addition, this invention also discloses a method for preparing the biochip with a three-dimensional mesoporous layer, including a blending process, a heating process, a coating process, a gelation process, a cleaning process, a drying process, and a surface modification process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a picture showing the flowchart for forming a biochip with a three-dimensional aerogel layer according to a preferred example of the present invention;
[0015] FIG. 2 is the absorption spectrum of FTIR after and before remove the solvent in three-dimensional aerogel layer according to a preferred example of the present invention;
[0016] FIG. 3 shows the analysis result of the unmodified three-dimensional aerogel layer according to a preferred example of the present invention by the 29 Si solid-state nuclear magnetic resonance spectrometer;
[0017] FIG. 4 shows SEM (scanning electron microscope) images of the surface of the three-dimensional aerogel layer (amplification factor=3000) according to a preferred example of the present invention;
[0018] FIG. 5 shows SEM (scanning electron microscope) images of the surface of the three-dimensional aerogel layer (amplification factor=300000) according to a preferred example of the present invention;
[0019] FIG. 6 is a N2 Adsorption/Desorption Analyzer curve of the three-dimensional aerogel layer modified by 10% GLYMO according to a preferred example of the present invention;
[0020] FIG. 7 is a the needle curve means the pore distribution of the three-dimensional aerogel layer according to a preferred example of the present invention;
[0021] FIG. 8 shows the TGA comparison data of the three-dimensional aerogel layer before/after modification according to a preferred example of the present invention;
[0022] FIG. 9 shows the digital camera picture of the quantum dot under UV light excitation according to a preferred example of the present invention;
[0023] FIG. 10 shows the result of the reformed quantum dot of the Fluoresce Spectrometer according to a preferred example of the present invention;
[0024] FIG. 11 shows the electrophoresis photograph of the reformed quantum dot and the un-reformed one according to a preferred example of the present invention;
[0025] FIG. 12 shows the flowchart of Sandwich Immunoassay according to a preferred example of the present invention;
[0026] FIG. 13 shows the images of the washed blank slide according to a preferred example of the present invention;
[0027] FIG. 14 shows the images of two-dimension chip after the amino reforming process according to a preferred example of the present invention;
[0028] FIG. 15 shows the scanned image from the three-dimensional structure Biochip with dropping 10 wt % Aerogel dispersal solution;
[0029] FIG. 16 shows the images of three-dimension chip after the amino reforming process according to a preferred example of the present invention;
[0030] FIG. 17 shows the appearance picture of the slide with three-dimensional Aerogel structure according to a preferred example of the present invention;
[0031] FIG. 18 shows the images of three-dimension chip after dropping the detected antibody according to a preferred example of the present invention;
[0032] FIG. 19 shows the images of three-dimension chip after the prohibition reaction is applied according to a preferred example of the present invention;
[0033] FIG. 20 shows the images of three-dimension chip after doing the prohibition reaction and following by drop the antigen (Human IL6);
[0034] FIG. 21 shows the images of three-dimension chip from labeling with the first antibody with the represent quantum dot color in the end; and
[0035] FIG. 22 shows the scanned images of two-dimensional protein biochip.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] What is probed into the invention is a biochip with a three-dimensional structure and a method for forming the same. Detail descriptions of the structure and elements will be provided as followed in order to make the invention thoroughly understood. The application of the invention is not confined to specific details familiar to those who are skilled in the art. On the other hand, the common structures and elements that are known to everyone are not described in details to avoid unnecessary limits of the invention. Some preferred embodiments of the present invention will now be described in greater detail as followed. However, it should be recognized that the present invention can be practiced in a wide range of other embodiments besides those explicitly described, that is, this invention can also be applied extensively to other embodiments, and the scope of the present invention is expressly not limited except as specified in the accompanying claims.
[0037] In one embodiment of the present invention, a method for forming a biochip with a three-dimensional structure is disclosed. At first, a precursor solution is provided. The precursor solution comprises an ionic liquid, a catalyzed hydrolysis and/or condensation reagent, and at least one alkoxide monomer and/or aryloxide monomer, where the catalyzed hydrolysis and/or condensation reagent comprises one selected from the group consisting of the following or any combination of the following: alcohol, acidic compound, and alkaline compound. The ionic liquid is used as a template as well as a solvent. The central element of the alkoxide monomer and/or aryloxide monomer comprises one selected from the group consisting of the following elements: Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Ti, Te, Cr, Cu, Er, Fe, Ta, V, Zn, Zr, Al, Si, Ge, Sn, and Pb. Next, a blending process for the precursor solution to hydrolyze and polymerize the at least one alkoxide monomer and/or aryloxide monomer until the viscosity of the precursor solution reaches a specific viscosity more than or equal to 150 cps. Then, setting the precursor solution to have the at least one alkoxide monomer and/or aryloxide monomer continue to undergo hydrolysis and condensation, so as to form a aerogel.
[0038] After the aerogel be formed, the extracting process is carried out by a solvent for the aerogel to substitute the ionic liquid in pores of the aerogel. Next, a drying process is carried out to remove the solvent in pores of the aeroge. Then, a grinding process is carried out to grind the aerogel to form a aerogel powder, and the diameter of the aerogel powder ranges about 10 nm to 250 nm. After the grinding process, a modification process is carried out and the internal and external surface of the aerogel powder was modified by a modifier with a specific moiety to form a modified aerogel powder. Finally, a coating process is carried out to coat the modified aerogel powder on a specific region of substrate, so as to form a biochip with a three-dimensional structure. The material of the substrate comprises one selected from the group consisting of the following materials: silicon chip, glass, or polymer.
[0039] The above-mentioned coating process described as followed: firstly dispersing the modified aerogel powder in a solution to form a modified solution; next coating the modified solution on a specific region of substrate; and finally performing a baking process to remove the solvent of modified solution and to enhance the adhesive force between the modified aerogel powder and the substrate, so as to form the biochip with a three-dimensional structure. In addition, the temperature of the baking process ranges from 80° C. to 120° C.
[0040] The precursor solution also comprises an acidic compound or alkaline compound to catalyze the hydrolysis/polymerization of the alkoxide monomer and/or aryloxide monomer. The method for preparing the precursor solution described as followed: firstly blending the alkoxide monomer and/or aryloxide monomer and the ionic liquid together to form a first mixture; next adding an acidic compound to the first mixture to form a second mixture; and finally adding an alkaline compound to the second mixture to enhance the hydrolysis/polymerization reactions of the alkoxide monomer and/or aryloxide monomer.
[0041] The common composition of the aerogel one selected from the group consisting of the following or any combination: SiO 2 , TiO 2 , V 2 O 5 , and Al 2 O 3 . The preferred solvent is the one with a low boiling point (less than or equal to 200° C.). The aerogel being substituted the ionic liquid in pores of the aerogel by the solvent. Preferably, the solvent comprises one selected from the group consisting of the following: nitrile, alcohol, ketone, and water. The average pore diameter of the aerogel ranges about 2 nm to 50 nm. The specific surface area is more than or equal to 100 m 2 /g and the porosity is 50%-99%.
[0042] The aerogel powder was modified by a modifier. The modifier for the modification process is an alkoxide monomer and/or aryloxide monomer with at least one specific moiety. The specific moiety comprises one selected from the group consisting of the following: amine group, hydroxyl group, carboxyl group, and epoxy group. The common modifier comprises N-[3-(trimethoxysilyllpropyl]-1,2-ethanediamine (DAMO), 3-Glycidoxypropyl-trimethoxysilane (GLYMO), 3-Aminopropyltriethoxysilane (APTS), N-(2-Aminoethyl)3-aminopropyltriethoxysilane (TMsen) and so forth. The modified aerogel powder is coated on a specific region of substrate with the coating process, so as to form a biochip with a three-dimensional structure.
[0043] According to the first example of the present invention, after the coating process, a converting process is carried out. At first, a converter that comprises a first moiety and a second moiety is provided. Then, the specific moiety of the aerogel powder is bonded with the first moiety of the converter to form a biochip having the second moiety on its surface. For example, when the modifier is N-[3-(trimethoxysilyllpropyl]-1 ,2 -ethanediamine (DAMO), glutaraldehyde can be used as the converter to form the mesoporous layer having aldehyde group on its surface. The converter comprises one selected from the group consisting of the following: antigens, primary antibody, monoclonal antibodies, polyclonal antibodies, nucleic acids comprising monomeric and oligomeric types, proteins, enzymes, lipids, polysaccharides, sugars, peptides, polypeptides, drugs, viruses, microbes, and bioligands.
[0044] According to the second example of the present invention, after the converting process, a blocking process is carried out. At first, a blocker that comprises a third moiety is provided. Then, the specific moiety of the aerogel powder is bonded with the third moiety of the blacker to form a biochip having the second moiety on its surface. The third moiety of the blacker reacts with specific moiety which non-reacts with the first moiety of converter.
[0045] According to the third example of the present invention, after the blocking process, a specific pairing process is carried out. At first, a pair that comprises a fourth moiety and a fifth moiety is provided. Then, the second moiety of the biochip is bonded with the fourth moiety of the pair to form a biochip having the fifth moiety on its surface. The pair comprises one selected from the group consisting of the following: antigens, primary antibody, monoclonal antibodies, polyclonal antibodies, nucleic acids comprising monomeric and oligomeric types, proteins, enzymes, lipids, polysaccharides, sugars, peptides, polypeptides, drugs, viruses, microbes, and bioligands.
[0046] According to the fourth example of the present invention, after the specific pairing process, a labeling process is carried out. At first, a labeling carrier that comprises a sixth moiety and a seventh moiety wherein conjugated with a marker is provided. Then, the fifth moiety of the pair labeling carrier is bonded with the sixth moiety of the labeling carrier to form a biochip having the marker on its surface. The marker comprises one selected from the group consisting of the following: fluorescence substance, phosphorescence substance, luminescence substance, enzyme, radioactive element, quantum dot, nano diamond. The labeling carrier comprises one selected from the group consisting of the following: antigens, primary antibody, labeling primary antibody, secondary antibodies, monoclonal antibodies, polyclonal antibodies, nucleic acids comprising monomeric and oligomeric types, proteins, enzymes, lipids, polysaccharides, sugars, peptides, polypeptides, drugs, viruses, microbes, and bioligands.
[0047] In the embodiment, the mentioned ionic liquids are room temperature ionic liquids (RTIL's), and is formed by mixing an organic base with a Lewis acid. When the Lewis acid is halogenated acid, it can form a room temperature ionic liquid but will produce halogen acid if reacting with water. Therefore, the halogenated acid is not suitable for the present invention. The Lewis acid used by the present invention is not halogenated acid so as to prepare a stable ionic liquid in water. In a preferred example, the cationic moiety in the organic base is alkyl or aryl group having the following general equation:
[0000]
[0000] in which R 1 , R 2 , R 3 , and R 4 are selected according to the following table.
[0000] R 1 R 2 R 3 R 4 CH 3 H CH 3 H C 2 H 5 H CH 3 H C 2 H 5 H C 2 H 5 H CH 3 CH 2 CH 2 CH 2 H CH 3 H (CH 3 ) 2 CHCH 2 H CH 3 H CH 3 CH 2 CH 2 CH 2 H C 2 H 5 H CH 3 H CH 3 OCH 2 CH 2 H CH 3 H CF 3 CH 2 H CH 3 CH 3 C 2 H 5 H CH 3 CH 3 CH 3 CH 2 CH 2 H C 6 H 6 CH 2 CH 3 CH 3 CH 2 CH 2 H C 6 H 6 CH 2 CH 3 CH 3 CH 2 CH 2 CH 2 H C 6 H 6 CH 2 CH 3 (CH 3 CH 2 )(CH 3 )CH H C 6 H 6 CH 2 CH 3 CH 3 CH 2 CH 2 CH 2 CH 2 H CH 3 H C 2 H 5 CH 3 C 2 H 5 H C 2 H 5 CH 3
For example, the common organic cationic moiety comprises one selected from the group consisting of the following: 1-n-butyl-3-methylimidazolium (BMI), 1-octanyl-3-methylimidazolium (OMI), 1-dodecanyl-3-methylimidazolium (DMI), and 1-hexadecanyl-3-methylimidazolium (HDMI). In addition, the anionic moiety in the Lewis acid comprises one selected from the group consisting of the following: BF 4 − , PF 6 − , AsF 6 − , SbF 6 − , F(HF) n − , CF 3 SO 3 − , CF 3 CF 2 CF 2 CF 2 SO 3 − , (CF 3 SO 2 ) 2 N − [TFSI], (CF 3 SO 2 ) 3 C − , CF 3 COO − , and CF3CF 2 CF 2 COO − . When the cationic moiety to be used is determined, the anionic moiety in the Lewis acid can be adjusted to control hydrophilicity/hydrophobicity. For example, BMI-BF 4 is hydrophilic and BMI-TFSI is hydrophobic.
[0048] For instance, alkyloxide monomer is used as an example. Alkyloxide monomer is hydrolyzed to form hydrophilic silanol (—Si—O—H). Thus, the hydrophilic ionic liquid and silanol are tended to attract to each other and can stabilize the formation of silicon oxide structure so as to obtain more stable three-dimensional silicon oxide mesoporous material. In this embodiment, the weight of the ionic liquid is about 10%-70% weight of the at least alkoxide monomer and preferably about 20%-50%. When the added amount is more than the upper limit, the sol concentration is reduced and the gelation is slow to result in unstable structure.
[0049] In this embodiment, the method for forming the biochip with a three-dimensional structure comprises one selected from the type consisting of the following: direct immune, indirect immune, complement fixing immune, sandwich immune.
EXAMPLE
[0050] According to a preferred example of the present invention, the method for forming a biochip with a three-dimensional aerogel layer is provided. The method comprises the following steps.
(1) Wash the slide:
Immerse the slide in the NaOH solution and shake by Sonicator for 30 min. Then replace NaOH solution with distilled water and vibrate for 30 min again. Lastly, replace distilled water with Acetone and again vibrate for 30 min. Take the slide out and dry them by oven.
(2) Aerogel preparation:
Mix BMIC-BF4 with formic acid solution first, then mix with TEOS again quickly. Set there and wait till hydrolysis and aging. After it gets well-aging, wash the sample and freeze-dry it. Lastly, grind the sample to become powder then the product is formed and can be used.
[0055] The Aerogel chemical reaction equation is below:
[0000]
(3) Reform the Amino base in Aerogel:
Mix the Aerogel powder with 2% DAMO solution well and keep stirring for 1 hour. Filter the mixture and wash it for 24 hours. Afterward, put the,whole sample in the oven to dry it.
(4) Synthesis the Aerogel on slide:
Prepare the 10% dispersal solution by dispersing the reformed Aerogel in double distilled water and keep stirring that with magnetic bar. Drop 2 ul of dispersal solution on the slide by pippet.
(5) Reform the quantum dot:
Prepare the SBB buffer solution: 3.09 g boric acid+19.07 g sodium borate. Adjust the pH to 9 with NaOH or HCl solution.
[0062] Calculate the amount of EDC, PEG and sulfo-NHS required. Put the required amount of the compounds in the microtube and record the amount in the microtube. Afterward, according to the amount in the microtube, calculate the volume of buffer needed. The next steps will be to mix the required ratio of quantum dot with the buffer. First of all, put PEG in the buffer and vibrate until it dissolves completely. The next step is to mix EDC with the buffer very quickly and add the quantum dot to neutralize the reaction immediately. Then mix sulfo-NHS with the buffer. Lastly, add the quantum dot into the sulfo-solution and add the PEG solution immediately too.
[0063] Vibrate and shake the whole mixture in 4° C. refrigerator for 2 hours. After the reaction is complete, filter the solution by molecular sieve. The residue solution is the branch with quantum dot. The reaction of quantum dot is shown below:
[0000]
(6) Branch the quantum dot with antibody:
PBS buffer is prepared by dissolving 0.24 g KH2PO4, 1.44 g Na2HPO4, 0.2 g KCl and 8 g NaCl with double distilled water. Then adjust the pH to 7.5 with NaOH or HCl solution. Washing buffer is prepared by adding 20.5ul Tween 20 into 580 ml PBS buffer and mix well. Mix the required amount of antibody with the quantum dot. Slightly vibrate the solution and then set the mixture in 4° C. refrigerator overnight. The branch reaction of quantum dot and antibody as shown below:
[0000]
(7) Implant antigen and antibody on biochip
Drop 1 ul of the different concentration antibody(Mouse anti Human, IL-6) on the scheduled area of the slide. Leave the slide in 37° C. oven for 2 hours reaction. Afterward, wash the sample around 1 minute by vibrating with buffer 3 times. Begin the blocking reaction: spread 1% BSA and PBS on the slide. Immerse the slide in a water tank in 4° C. refrigerator overnight. Afterward, wash the slide around 1 minute by vibrating with buffer 3 times. Drop 1 ul of the antigen (Human IL-6) branched with quantum dot on the same spot on the slide. Leave the slide in 30° C. oven for 1 hour reaction. Then wash the slide around 1 minute by vibrating with buffer 3 times. Drop 1 ul of the antibody (Rabbit anti human, IL-6) branched with quantum dot on the same spot on the slide. Leave the slide in 30° C. oven for 1 hour reaction. Then wash the slide around 1 minute by vibrating with buffer 3 times. Lastly, drop 1 ul of the pure quantum dot on the positive control spot on the slide. After steps (1) to (7) are completed, the slide with Aerogel is formed with the white appearance on the top. This area is the sample evaluation region.
[0073] FIG. 2 is the analytic result of the infrared absorption spectrum of Aerogel structure. This result demonstrates that there is a —O—H bonding absorption peak during 3200-3700 cm-1 and 1620-1640 cm-1. Most of the absorption peak during 3200-3700 cm-1 is because of the O—H bond in cm-1H bonding vibration. The absorption peak of the 930-950 cm-1 wave is because of the Si—OH bonding vibration. The other waves like 1000-1200 cm-1, 780-820 cm-1 and 430-460 cm-1 will be the bonding extended vibration of ≡Si—O—Si≡.
[0074] As long as the atom has the spin angular momentum, like if the atom with the odd atomic number or proton number will have the absorption with Nuclear Magnetic Resonance. The common liquid Nuclear Magnetic Resonance (NMR) is usually applied to identify the organic structure. But the detected condition will always be limited by the D solution. Due to advances in solid Magnetic Resonance Imaging (MRI), the solid sample can be detected directly. It's also more understandable of the advance research on chemical structure, bond association and kinematics. We can use the 29Si solid NMR to analyze Si bonding distribution in Aerogel. Based on this study, it clarifies the bonding situation of the net-cross-binding structure in TEOS with dissolved gel-gel reaction. According to the analysis of Silica Aerogel from the 29Si solid NMR spectrum, the particular absorption peak during −99-−102 ppm will appear when the 3nd replacement of Silica happened. The particular absorption peak during −107-−110 ppm will appear when the 4th replacement of Silica happened. The 29Si solid NMR spectrum analysis ( FIG. 3 ) showed the main bonding was the 4th replacement (Q4) of Si at −111 ppm. The sub-bonding was the 3nd replacement (Q3) of Si at −102 ppm. This result appears that Silica Aerogel can stable silica net-cross-binding structure.
[0075] As it's shown in FIG. 4 and FIG. 5 , according to the micro-observation on Aerogel surface by SEM system, the Silica Aerogel surface displays the sphere conformation ( FIG. 4 , 30k fold amplifier). Furthermore, the sphere shape is composed by more and tinier silica ( FIG. 5 , 300k fold amplifier). The silica aggregation size is around 20-30 nm which can approve this is the Nano-grande Aerogel material.
[0076] N 2 Adsorption/Desorption Analyzer can measure the property of the material surface. The theory is using Inert Gas to detect the pore size, surface area and pore structure on the material surface physical property. The adsorption degree related to the samples and the property of the used adsorption gas, and can also be the function of the pressure(or concentration) and temperature. The adsorption degree to P/P0 figurer usually is made by the sample (gram) in constant temperature. P0 is the saturated vapor pressure of the analysis gas in experiment temperature. This curve named Adsorption Isotherms. Base one the FIG. 6 , the N2 Adsorption/Desorption Analyzer curve of Silica Aerogel, Silica Aerogel was made with 812 m2/g surface area, 1.97 cm3/g pore volume and 9.4 nm is the average pore size. Besides, FIG. 7 with the needle curve means the pore distribution on Silica Aerogel is very condensed.
[0077] FIG. 8 is the TGA curve of Silica Aerogel (detected condition: N2, T=30-1000° C. , temperature increasing rate=10° C./min). The result of the solid line shows that 2.6 wt % of Silica Aergel was lost when the temperature was lower than 100° C. . The loss might be from some humidity from the surface adsorption of the Silica Aerogel. 6.2 wt % of Silica Aergel was lost when the temperature reached to 100° C. The lost might be from some oxyhydrogen-silica base which is not hydrolysis or condensate completely of the surface adsorption of the Silica Aerogel.
[0078] In the other way, the dotted line showed the unclean situation of the Silica Aerogel. If there is some residuum on the template, the template would start to crack when the temperature reached to 265° C. . This is also the way to determine if the washing step is completely.
[0079] Different sizes of the nano level quantum dot will show the different fluorescence under different UV light. FIG. 9 showed the digital camera picture of the quantum dot under UV light excitation. The excitation is around green light region.
[0080] The reform of the quantum dot is changing the amino base of the hydrophilic surface of the quantum dot. Make this site as an experiment marker for the carboxyl reaction with antibody. FIG. 10 showed the result of the reformed quantum dot of the Fluoresce Spectrometer. The excitation Wave switch to 540 nm is because of the reformed amino base on quantum dot surface. This result means the reform is successful.
[0081] Heavier molecular weight will move slower than the light molecular weight during the electrophoresis process with the same electronic pressure and time. The reformed quantum dot is heavier than the un-reformed one, so the electrophoresis can be the way to detect if the reform is successful. FIG. 11 , the reformed quantum dot moved slower than the un-reformed one considered the reform is success.
[0082] Adding the buffer solution during the reform process makes the concentration different from the un-reform. Measurement of the concentration again is needed after the reform process. Fix the wave in 527 nm to do the single detection with reformed quantum dot. Measure the absorption and then calculate the concentration afterward.
[0083] The concentration calculation function:
[0000]
C=A/εL
[0084] A is the Absorption. E is the constant of the Molar absorption (M−nm)−1. L is the particle diameter (nm). The concentration calculated function below is the sample of FIG. 9 with the right tube of the quantum dot:
A=0.04 L=0.512 ε=77793.9851 Complete the function,
[0000] 0.04/(77793.9851×0.512)=1.00×10-6
The calculated concentration will be 1.00×10-6 M
[0090] Here we have made the protein biochip. This kind of biochip is made by the specific of special three-dimensional structure with protein-protein, protein-small molecular to detect the particular protein.
[0091] As shown in FIG. 12 , this experiment is applied with Antibody Sandwich Immunoassay(ELISA). Antibody is the bio-detector and fixed on the biochip, then the antibody will have a specific binding with a particular antigen. Besides, the antibody branched with quantum dot is the target in the experiment. If the particular antigen and antibody aren't bind or the antibody and antigen are not corresponding then the fluorescence image won't show up in the fluorescence scanner screen.
[0092] The fluorescence chip-scanner GenePix 40000B is using dual-laser scanning system to generate the real time ratio image. The ratio image is composed by red, green, blue color with the standard 24 bite. The scanner system default is 635 to 532 nm of laser.
[0093] FIG. 13 is the washed blank slide. The background value is extremely low as blue color. Use this background value as the standard to compare the rest of the reform slides are with the good background value. For demonstration of the detected result with the three-dimensional Aerogel chip, the 2-dimenetion chip made by the reformed slides is the comparison corps, so the two-dimension chip with reformed amino base (2% DAMO) would be the first issue need to be demonstrated. The reformed procedures of the slides: immerse the slides in the staining container with 2% DAMO prepared by Ethanol for 4 hours reaction. Wash with double distilled water. Put it into the oven for 20 minute. FIG. 14 showed that most of the background is still navy blue (deep blue) after the amino reforming process. Although some small light blue dots appear, the background value is still acceptable.
[0094] FIG. 15 showed the scanned image from the three-dimensional structure Biochip with dropping 10 wt % Aerogel dispersal solution. The round dot is the dropping Aerogel. The image color is light blue which is still included in low background value. FIG. 16 showed turquoise (blue-green color) from the amino reformed Aerogel.
[0095] FIG. 17 showed the appearance picture of the slide with three-dimensional Aerogel structure. First of all, the sample evaluation region is formed by steps (1) to (7). Second, the positive control spot is the Aerogel reformed by epoxy group directly branched with amino base reformed quantum dot. On the other hand, the negative control spot is the un-reformed Aerogel. The purpose of the positive control spot is to standardize the different batches of Biochip. It's possible that different batches of the Biochip have uneven quality which causes the different intensities of brightness in the biochip scan results. End up the data is out of comparison. Use the positive control spot to standardize the detection result of the different batches of Biochips. This makes the experiment more meaningful. Additionally, the purpose of the negative control spot is to measure the background value of the Aerogel alone. This can be deducted in the background value in the following data analysis.
[0096] FIG. 18 showed the background value is still in blue-green color after dropping the detected antibody (Mouse anti Human IL6). FIG. 19 showed the background value is still in blue-green color after the prohibition reaction is applied. FIG. 20 showed the background decrease slightly to light blue after doing the prohibition reaction and following by drop the antigen (Human IL6). FIG. 21 showed the all orange-yellow color is from labeling with the first antibody (Rabbit anti human IL-6) with the represent quantum dot color in the end. This result means the Antibody Sandwich Immunoassay is successful. FIG. 22 showed the scanned picture of two-dimensional protein Biochip.
[0097] This is the scanned image result of the comparison of the three-dimensional Aerogel chip and two-dimension protein chip which is performed by antibody and antigen specific reaction.
[0098] The chip scanner analysis software (GenePixPro6.0) analyzes the particular different signal spot in three-dimensional Aerogel chip and 2-dimension protein chip. The result is listed in Table 1 and Table 2.
[0099] Table 1 is the result of the three-dimensional Aerogel chip shown as below:
[0000]
sample
concentration
intensity
color
1
1.44 × 10 −6
26213
orange-yellow
2
1.44 × 10 −6
28527
orange-yellow
3
1.44 × 10 −6
29041
orange-yellow
4
1.46 × 10 −6
31609
orange-yellow
5
—
11125
blue
[0100] Table 2 is the result of the 2-dimension protein chip shown as below:
[0000]
sample
concentration(M)
intensity
color
1
1.0
52029
white
2
1.0 × 10 −1
23130
red
3
1.0 × 10 −2
30067
orange
4
1.0 × 10 −3
22615
green
5
5.0 × 10 −4
16756
blue
[0101] According to Table 2, when the sample concentration reaches 5.0×10 −4 M in 2-dimension protein chip, the chip signal is around 16756 which is close to light blue background value. The hypothesis is when the sample concentration is to low (10 −5 ), the chip scanner can't detect the signal. When the concentration of three-dimensional Aerogel chip is lower than 1.44×10 −6 M, the signal intensity is amplified to 26213-31609 because of the Aerogel three-dimensional structure. It is thus evident that the bigger the surface area of three-dimensional Aerogel, the stronger the signal intensity.
[0102] Other modifications and variations are possibly developed in light of the above demonstrations. It is therefore to be understood that within the scope of the appended claims the present invention can be practiced otherwise than as specifically described herein. Although specific embodiments have been illustrated and described herein, it is obvious to those skilled in the art that many modifications of the present invention may be made without departing from what is intended to be limited solely by the appended claims.
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The present invention discloses a biochip with a three-dimensional structure. The surface of the three-dimensional mesoporous layer is chemically modified to recognize labeled DNAs, proteins, peptides, saccharides, and cells. In addition, this invention also discloses a method for preparing the biochip with a three-dimensional mesoporous layer, including a blending process, a heating process, a coating process, a gelation process, a cleaning process, a drying process, and a surface modification process.
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BACKGROUND OF THE INVENTION
Frequently, in the geophysical drilling industry areas of high-pressure water or other high-pressure fluids are encountered. These high-pressure areas must be efficiently sealed to prevent the escape of these fluids to the surface of the ground.
Seal plugs presently in use tend to be difficult to install, expensive to install, and frequently ineffective when installed. Special equipment, special tools, and large expenditures of manpower are necessary to install these plugs presently in use.
A new and unique seal plug system is necessary for use in this industry.
OBJECTS OF THE INVENTION
The primary object of the disclosed invention is to provide an efficient, easy-to-install, inexpensive seal plug system.
A further object of the disclosed invention is to provide a flexible seal plug system so as to pass by obstacles and obstructions encountered in the bore hole.
A further object of the disclosed invention is to provide a seal plug system which may be inserted into the bore hole and lowered by its external fluid supply hose.
A further object of the invention is to provide a seal plug system in which the valve inflation control system is totally enclosed in the plug system.
An additional object of the disclosed invention is to provide a flexible internal fluid delivery system able to accommodate changes in the size of the plugs.
DESCRIPTION OF THE DRAWINGS
FIG. 1a is a fragmentary diagramatic view of an un-inflated flowing hole plug system in a bore hole.
FIG. 1b is a fragmentary diagramatic view of an inflated flowing hole plug system in a bore hole.
FIG. 2 is a cross-section view of the flowing hole plug system.
DESCRIPTION OF THE INVENTION
The plug system P is shown in FIGS. 1a and 1b positioned in a bore hole H in a geophysical area having an underground stream S. A fluid supply line L supplies fluid to the system P from above ground.
Referring now to FIG. 2, the system P includes the lower hole plug 10 and the upper plug 12. It is seen that both plugs 10 and 12 are cylindrical in shape and that the length of the cylinder exceeds its diameter. Both plugs 10 and 12 include flexible and inflatable housings 14 and 16, which are closed at each end by an inverted flange or sealing lip 18, 20, 22 and 24. Through the longitudinal center of each of inverted flanges 18, 20, 22 and 24 are orifices.
Both plugs 10 and 12 are manufactured from a flexible, resilient, rubber-type material. The material is impervious to attack by oil and gas and flexible at either temperature extreme, and in practice the metal components of the plugs will oxidize before the rubber-type material is affected by subsurface gases.
Each of the plugs 10 and 12 include closure caps 34, 36, 38 and 40 which are cylindrical in shape and have their outside diameters corresponding to the inside diameter of their respective hole plug 10 and 12. Located in the longitudinal centers of the closure caps 34, 36, 38 and 40 are threaded bores 42, 44, 46 and 48 extending partially into the closure cap 34, 36, 38 and 40. Circumferentially located about the bores 42, 44, 46 and 48 and aligned with the inward sealing lips 18, 20, 22 and 24 are cap sealing grooves 50, 52, 54 and 56. These cap sealing grooves 50, 52, 54 and 56 accept with and seal with the inward sealing lip 18, 20, 22 and 24. The closure caps 34, 36, 38 and 40 are manufactured of a metal or other suitable material. The weight of the closure caps 34, 36, 38 and 40 tends to help overcome the natural buoyancy of the inflatable flowing hole plug system P.
Threaded into the closure cap 34 is a solid, threaded locking pipe 58. This locking pipe 58 extends into the bore 42 of the closure cap 34. Surrounding the locking pipe 58 in a washer and nut tightening assembly 60. This assembly 60 is tightened to seal the inward sealing lip 18 against the cap sealing groove 50 to thereby prevent leakage of fluid into or out of the plug 10.
Circumferentially around each of the plugs 10 and 12 are a number of external sealing ribs 62. Three ribs 62 are provided for each plug, although a greater or fewer number may be used. These ribs 62 extend into and make contact with the surrounding strata when the plugs 10 and 12 are inflated. In this way the plug system P becomes an integral part of the surrounding strata and a positive mechanical seal is attained.
At the upper end of the lower plug 10 is a cylindrical closure cap 36. This cap 36 has a threaded bore 44 extending longitudinally through its center starting at the outside of the lower plug 10. The threaded bore 44 extends partially through the closure cap 36 and a smaller bore 64 extends through the rest of the closure cap 36. In this way, a means for supplying fluid to the plug 10 is provided.
A hollow, threaded central connector pipe 66 extends partially into the threaded bore 44. Surrounding the central connector pipe 66 is a washer and nut tightening assembly 60 for sealing the inward sealing lip 20 with the cap sealing groove 52 of the closure cap 36. This inward sealing lip 20 and cap sealing groove 52 are similar to those of the lower closure cap 34. The washer and nut tightening assembly 60 is tightened to prevent the entrance or escape of fluid.
At the lower end of the upper plug 12 is a similar inward sealing lip 22. A lower closure cap 38 seals with the sealing lip 22. A threaded longitudinal bore 46 extends partially through the closure cap 38. Two small additional cores 68 and 70 are tapped into the closure cap 38 and meet with the threaded bore 46 and so allow fluid communication.
The central connector pipe 66 is threaded into the closure cap 38 and thereby connects the two plugs 10 and 12. A washer and nut tightening assembly 60 is provided and thereby the two plugs 10 and 12 are in fluid communication with each other through the central connector pipe 66.
Two ball check valves 72 and 74, the upper one of which is shown in detail broken away in FIG. 2, are provided although other types may be used and are attached to the two internal bores 68 and 70 of the closure cap 38. The lower hole plug 10 fluid inlet valve 72 is connected at the other end to an S-shaped flexible internal fluid inlet hose 76. The S-shape of the hose 76 allows for expansion and contraction longitudinally and laterally along the axis of the plug 12. The upper hole plug 12 inlet valve 74 vents into the upper plug 12.
At the upper end of the upper plug 12 is a closure cap 40. This cap 40 has a longitudinal threaded bore 48 through its center extending partially through the cap 40. A smaller bore 78 extends from the threaded bore 48 through the closure cap 40 and is connected to the other end of the internal fluid inlet hose 76. An inward sealing lip 24 and cap sealing groove 56 are provided at the interface of the cap 40. Extending into the threaded bore 48 is a hollow, threaded pipe 80. The pipe 80 is surrounded by a washer and nut tightening assembly 60. The pipe 80 extends beyond the inverted flange 24 of the plug 12. The external fluid supply hose L is connected to the pipe 80 and in this way, the fluid is supplied to whole plug system P.
OPERATION
In operation the flowing hole plug system P is lowered into the bore hole H by the external fluid supply hose L to the proper depth. At that point, fluid delivery is initiated. The lower plug inlet valve 72 is pre-set to allow fluid flow into the lower plug 10 at almost any delivery pressure. The upper plug inlet valve 74 is pre-set for a higher delivery pressure than that of the lower plug inlet valve 72. Consequently, when the lower plug 10 builds up sufficient back pressure, the upper plug 12 inlet valve 74 will open and inflate the upper plug 12. In this way, both plugs 10 and 12 will be inflated, the ribs 62 embedded into the wall of the bore hole, and stress on the plug system P between plugs 10 and 12 will be kept at a minimum. Simultaneous inflation of both plugs as in the prior art reduces plug life. In the event that either plug 10 or 12 should become deflated, the ball check valves 72 and 74 serve to keep the fluid in the remaining plug 10 or 12.
FIG. 1b additionally shows the bore hole above the plug system being filled with concrete after inflation. The external fluid hose L, a permanent part of the plug, being left in the bore hole.
While in prior art systems the drill pipe "string" is used to lower a sealing plug to the desired level in information, and pressurized fluid such as air is fed through the "string" to inflate the plug, the system of the present invention, in its preferred form, utilizes to advantage an external hose L attached to the upper end of the upper plug 12. The system therefore, namely the plugs and hose make the subject invention readily portable in that the plugs can be quickly removed from the operator's vehicle, lowered down the bore hole and inflated, without having to assemble any parts. Many flowing holes, as will be appreciated, are surrounded by a small pond created by the subsurface water flowing to the surface and lying in a large pool. Understandably, as each day passes the pool will grow hence making it difficult to drive a fluid unit directly to the site of a flowing hole. With the use of the plug system according to the present invention, the operator needs only to carry the plugs assembly in one hand and a small pressurized air tank in the other. Thus, the operation is greatly simplified.
While this invention has been described as having a preferred design, it will be understood that it is capable of further modification, uses and/or adaptations of the invention following in general the principle of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth, as fall within the scope of the invention or the limits of the appended claims.
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An inflatable flowing hole plug system including two fluid inflatable hole plugs, having an upper and a lower plug, a connector pipe for connecting these plugs and allowing fluid communication between them, a valve system for controlling the inflation of the plugs and an external fluid supply apparatus for inflating the plugs is disclosed.
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BACKGROUND OF THE INVENTION
Reduction cells for reducing alumina to aluminum require adequate insulation in the cathode to limit heat losses from the steel shell surrounding the cathode during cell operation. Cryolitic salts and vapors, containing an excess of sodium fluoride, penetrate through the carbonaceous cathode lining and chemically attack and degrade the thermal insulation in the bottom of the cathode shell. As the insulation is degraded, the insulation loses its effectiveness as a thermal insulation material and heat losses through the insulation increase. As a consequence, the cell voltage must often be increased in order to maintain a stable thermal equilibrium in the cell. If this is not done, the temperature of the electrolyte decreases, resulting in increases in anode effects and/or reduced interelectrode distance in the cell. Either of these consequences results in reduced productivity and/or increased operating costs for the cell.
The highly corrosive cryolitic salt vapors penetrating through the cathode lining can be stopped in either of two ways. If the temperature isotherm through the insulation is maintained sufficiently low, i.e., less than about 600° C., to prevent any mobility and thereby any reactivity of the salts above their freezing points, these salts do not migrate to the insulation layers. This is, however, an extremely inefficient way to operate an alumina reduction cell, and thus the benefits to be gained by prohibiting cryolitic salt vapor penetration to the insulation are more than offset by other system inefficiencies.
The other alternative method to protect alumina reduction cell insulation from cryolitic salt vapors is by means of a physical barrier material. This barrier is positioned above the low temperature insulation material and beneath higher temperature insulation material which is in contact with the carbon cathode and cell bottom wall. Numerous materials have been tried in the past as a barrier layer, with the most common material being a steel plate. It is difficult, however, to obtain a unitary steel plate of a size sufficient to cover an alumina reduction cell and gaps between steel plates which are laid next to one another to form a sufficient size barrier layer provide regions for vapor penetration.
In U.S. Pat. No. 4,411,758 a low softening point glass, such as soda-lime glass, typically in the form of cullet, is disclosed as a physical barrier layer for alumina reduction cells. It has been found, however, that such a soda-lime glass layer is ineffective as a barrier material in resisting cryolitic salts and vapors in reduction cell cathodes. Its chemical reactivity, due to its chemical composition, and its relatively low softening point, flow point and surface tension, make this material difficult to contain in the alumina reduction cell at normal operating temperatures, i.e., at or above about 900° C., during cell operation as well as providing less than desired protection for the insulation material.
There remains a need, therefore, to provide a reliable alumina reduction cell barrier material.
THE PRESENT INVENTION
By means of the present invention, this desired goal has now been obtained. The present invention comprises a barrier layer for an alumina reduction cell which comprises borosilicate glass. The borosilicate glass is preferably provided as cullet, or other ground glass, and during start-up of the cell, softens and fuses into a continuous plastic layer, thereby forming a non-rigid, conformable barrier when the cell reaches its operating temperature. The semi-liquid, plastic glass layer will either react or fuse with the cryolitic salt and vapors to form higher melting temperature compounds, which will convert the temporary plastic glass barrier into a permanent rigid barrier, or the cryolitic salts and vapors will not react with the glass due to the immiscible, insoluability of the components involved. In the latter case, a high glass viscosity is desirable to increase and/or maintain the immiscibility of the components.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be more fully described with reference to the FIGURE which is a cross-sectional view of an alumina reduction cell cathode employing the barrier layer of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the FIGURE, an alumina reduction cell cathode 1 is shown in cross section. The cell 1 includes a generally rectangular shaped open top steel shell 10, one or more layers 20 of low temperature refractory insulation, a layer 18 of high temperature refractory insulation, insulation barrier 22, surrounded by optional barrier layers 24 and 26, a layer of prebaked and/or monolithic rammed carbon 12 on the bottom and sidewalls of cell 1, a carbonaceous cathode 14 and bus bars 16 which connect the cathode 14 to a source of electric current.
High temperature insulation layer 18 may be formed from such materials as metalurgical powder alumina or refractory brick, and is typicially formed as a monolithic unit. Low temperature insulation 20 may be formed as a monolithic unit, or may be formed from one or more layers of refractory blocks, formed from such materials as vermiculite or calcium silicate slabs, or insulating bricks.
The barrier layer 22 is formed from a borosilicate glass. The borosilicate glass is preferably supplied as ground glass or cullet, typically providing a layer of between about 0.5 and about 3.0 inches (1.270 and 7.620 centimeters) and, during start-up of the cell, softens and fuses into a monolithic layer 22. The borosilicate glass layer 22 may have a composition comprising
SiO 2 about 65 to about 85
Na 2 O about 3.5 to about 6.5
K 2 O about 0 to about 1
B 2 O 3 about 5 to about 30
Al 2 O 3 about 0 to about 6
on a percent by weight basis and may have the following physical properties:
Softening Point, °C. about 750 to about 825
Flow Point, °C. about 900 to about 1100
Density, g/cc about 2.1 to about 2.3
Surface Tension, Dynes/cm about 345 to about 350
The borosilicate glass may be, for example, a Pyrex® glass. The borosilicate glass is effective as a barrier to the cryolitic salts and vapors due to its chemical composition and higher softening point and flow point than soda-lime glass. The boric oxide in borosilicate glass has less effect than soda in lowering the viscosity of the silica and requires higher melting temperatures than soda-lime glass. Borosilicate glass has a good resistance to the corrosive effects of acids.
Thus, for example, the borosilicate glass has a softening point aproximately 50° to 100° C. higher than that of soda-lime glass and has flow point substantially higher than the operating temperature of an alumina reduction cell. Further, the surface tension of borosilicate glass is in excess of that of soda-lime glass, aiding in the physical barrier abilities of the borosilicate glass.
Also illustrated in the FIGURE are a pair of optional alumina silicate blankets 24 and 26. While required for soda-lime glass barriers, such as those illustrated in U.S. Pat. No. 4,411,758, in order to sufficiently wet the soda-lime glass, these layers are optional in the barrier system of the present invention. When present, however, they are typically in the form of an alumina silicate fiber paper and each have a thickness ranging between about 0.125 and about 0.250 inches (0.318 and 0.635 centimeters).
EXAMPLES
In order to compare the borosilicate glass barrier of the present invention with a soda-lime glass barrier as taught in U.S. Pat. No. 4,411,758, an alumina reduction cell was constructed having coupons imbedded therein at the location illustrated in the FIGURE for layer 22 as follows:
______________________________________EXAMPLE NO. MATERIAL______________________________________1 a 1" thick layer of borosilicate cullet2 a 1" thick layer of borosilicate cullet3 a 1" thick layer of soda- lime cullet4 a 1" thick layer of soda- lime cullet______________________________________
The alumina reduction cell was operated for a thirteen-month period, at which time the cell was disassembled and the coupons inspected. The results of the examples are as follows:
______________________________________EXAMPLE NO. RESULTS______________________________________1 a 1/8 to 1/4 thick, continuous glass barrier was intact2 a 1/4 to 3/8 thick, continuous glass barrier was intact3 the glass was reacted and dispersed as globules in the cryolitic salts4 the glass was reacted and dispersed as globules in the cryolitic salts______________________________________
It is clear from these Examples that while the borosilicate glass barriers of the present invention withstood the rigors of an operating alumina reduction cell for the test period, the soda-lime glass barriers were unable to function over the life of the cell.
From the foregoing, it is clear that the present invention provides an improved barrier system for protection of thermal insulation in an alumina reduction cell.
While the invention has been described with reference to certain specific embodiments thereof, it is not intended to be so limited thereby, except as set forth in the accompanying claims.
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A protective barrier for alumina reduction cell cathodes is disclosed. This barrier layer comprises a layer of borosilicate glass which may optionally be surrounded by layers of alumina silicate glass. The barrier prevents cryolitic salts from attacking the reduction cell insulation, preventing degradation of the insulation and improving cell efficiency.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of manufacturing preassembled tape strips. More particularly, the present invention relates to manufacturing tape strips of a predetermined length, which are at one end folded about an aperture of a workpiece.
2. Description of the Prior Art
In the manufacture and assembly of fastening products, such as tape strips, belts and straps, there is commonly a need for the attachment of additional workpieces in order to provide a finished product. These additional devices may include, for example, rings, buckles or notions which allow for the tape strips, belts or straps to be attached or connected in some fashion.
Currently, the preferred method of attaching these buckles or notions to, for example, a tape strip, has been through sewing. In the conventional art, a tape strip is commonly folded about a workpiece and sewn to itself to create a strap that has the workpiece at one end. The other end of the strap is either sewn into a final product or connected in a similar fashion to another workpiece such as a buckle. These straps are used as part of backpacks, bags, luggage, life vests, etc. Various methods are used in the art to partially assemble a tape strip about a connecting device. These methods involve gluing or spot welding the strap to itself once the strap is folded about the connecting device. The partially assembled straps are then sent to a final sewing stage and incorporated into a final product.
U.S. Pat. No. 5,795,434 discusses the problems associated with assembling these tape strips in the prior art. In particular, the prior art describes methods for producing tape strips folded about a ring. The article described is manufactured by severing a predetermined length off a continuous tape, inserting the thus obtained tape strip through the ring, and folding the tape strip through and about the ring outwardly. In order to facilitate a subsequent sewing work, a laminate portion of the folded tape strip is provisionally secured, by hand, with a thread, a staple or any other fastener to keep the tape strip in a folded form. According to the conventional technology, however, production of the tape strip folded about the ring chiefly relies on manual work and hence needs large manpower, which would be inefficient and would thus render the finished product more expensive to produce. Further, since the thread and/or staple used in temporarily securing the folded tape strip are unnecessary in a final product, such a fastener has to be removed from the folded tape strip by hand at the final stage of production. When the final product is included in articles for human use, such as trampolines, the need for the removal of staples becomes especially important. If, through human error, a staple is not removed, its inclusion in the article may easily cause injury to the consumer.
U.S. Pat. No. 5,795,434 solves the problem of the prior art by providing a machine and method for continuously manufacturing a tape strip folded about a ring. Tape drawer rollers are intermittently driven and a continuous tape is intermittently fed along a tape traveling path. A leading edge portion of the tape is inserted through a ring at a tape folding section. After the tape is fed a predetermined length through the ring, the tape is stopped and then the lower end portion of the tape inserted through the ring is bent about the ring by a first bending member. A cutting device then severs a predetermined length of tape strip off the continuous tape, whereupon the an upper half of the severed tape strip is bent about the ring by a second bending member, thus providing a folded tape strip having a laminate portion. Finally the folded tape strip is discharged out of a machine after part of its laminate portion is fused by a fusing device. The product which is created by this method provides a tape which is folded equally about a ring. This product is used as connection points on a trampoline.
However, there is still a need in the art to provide for a machine which continuously manufactures a tape strip folded about a connecting device wherein an additional length of tape extends beyond the tape which is folded about the connecting device. There is a further need for a machine capable of properly manipulating a tape strip to allow differing lengths of tape to extend beyond the tape which is folded about the connecting device. The product formed from this process can then be used in a large number of applications, such as backpacks, bags, luggage, life vests, and other uses which require tape strips attached to connecting devices.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide for an efficient method of producing a tape strip folded about a connecting device which has an additional length of tape extending beyond the tape which is folded about the connecting device.
It is a further object of the present invention to improve the efficiency of production of tape strips folded about a connecting device so that production of a final product using such folded tape strips can be facilitated.
It is another object of the present invention to manufacture a tape strip folded about a connecting device which has an additional length of tape extending beyond the tape which is folded about the connecting device.
It is yet a further object of the present invention to provide an improved method of properly manipulating a tape strip to allow differing lengths of tape to extend beyond a tape which is folded about a connecting device.
Objects of the invention are achieved by providing a machine for continuously manufacturing tape strips having at least at one end a portion folded through an aperture of a workpiece. The machine includes a tape supply section which accommodates a supply of tape having an indeterminate length. The tape supply section supplies tape to a tape feed unit which is adapted to intermittently supply a first predetermined length of tape and a second predetermined length of tape in a two stage operation. Work pieces are supplied to and received by a workpiece receiving device adapted to hold the workpiece and position the aperture of the workpiece in the tape traveling path. First and second tape folders are oppositely positioned on each side of the workpiece receiving device. These tape folders operate to move in and out of the tape traveling path. A tape fusing member is positioned above the workpiece receiving device and the tape traveling path. The tape feed unit supplies a first predetermined length of tape through the aperture of a workpiece along the tape traveling path. The tape feed unit then supplies a second predetermined length of tape that does not go through the aperture of the workpiece. First and second tape folders then move from their position outside of the tape traveling path to a position in the tape traveling path causing the tape to fold toward the heated tape fusing member above the workpiece receiving device.
The foregoing is illustrative of the objects and features of the present invention and is not intended to be exhaustive or limiting of the possible advantages that can be realized or achieved. These and other objects and advantages of the present invention will be readily apparent to those skilled in the art from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevated perspective view of a machine according to an embodiment of the present invention.
FIG. 2 is a detailed view of a workpiece supply path.
FIG. 3 is a detailed view of a welder and workpiece gripper assembly shown with tape folders in a retracted position.
FIG. 4 is a detailed view of a welder and workpiece gripper assembly shown with tape folders in a protracted position.
FIG. 5 is a detailed view of a tape supply section and associated tape feed unit with tape feed out of tape supply path.
FIG. 6 is a detailed view of a tape supply section and associated tape feed unit in with tape feed guide in the tape supply path.
FIG. 7 is a detailed view of a tape cutter assembly.
FIG. 8 is a detailed view of a tape gripper arm assembly.
FIG. 9 is an operational view of a workpiece gripper assembly and a workpiece supply path.
FIG. 10 is an operational view of a workpiece gripper assembly and a tape feed unit.
FIG. 11 is an additional operational view of a workpiece gripper assembly and a tape feed unit.
FIG. 12 is an operational view of a workpiece gripper assembly with tape folders in a protracted position.
FIG. 13 is an operational view of a workpiece gripper assembly and a tape gripper arm.
FIG. 14 is an additional operational view of a workpiece gripper assembly and a tape gripper arm.
FIG. 15 is an operational view of two tape gripper arms.
FIG. 16 is and operational view of a tape gripper arm and a cutter assembly.
FIG. 17 is an elevated perspective view of a completed tape strap.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein like numerals refer to like components, FIG. 1 illustrates a perspective view of one embodiment of a machine for continuously producing a tape strip folded about a workpiece (not shown). The machine includes a workpiece supplier, such To as a workpiece supply path 100 ; a workpiece gripper 200 which rotates from a position for receiving a workpiece from the workpiece supply path 100 to an upright position for holding a workpiece in a working position; a tape feed transfer unit 300 , which moves from a position distant to a workpiece gripper 200 to a position near the workpiece gripper 200 ; a tape cutter 400 ; a tape gripping assembly 500 ; and a tape fusing member 600 .
FIGS. 2 and 3 illustrate a workpiece supply path 100 and a workpiece gripper 200 , in further detail. Workpiece supply path 100 includes a workpiece track 102 , which provides for the delivery of only one workpiece, such as a buckle (not shown), at a time. Buckles originate from an automated workpiece supply 104 or are fed manually onto the workpiece track 102 . Buckles may then move down the workpiece track 102 and stop at a position above an upper stopper 106 . The upper stopper 106 includes an upper actuator 108 and an upper gate 110 . The upper actuator 108 moves the upper gate 110 from a closed position to an open position. When the upper gate 110 is open, buckles can move past the upper stopper 106 . Buckles, or similar workpieces, may then move down the workpiece track 102 past the upper stopper 106 and stop at a lower stopper 114 . The lower stopper 114 includes a lower actuator 116 and a lower gate 118 . The lower actuator 116 moves the lower gate 118 from a closed position to an open position. When the lower gate 118 is open, a predetermined number of workpieces, such as buckles can move past the lower stopper 114 . The distance between the lower stopper 114 and the upper stopper 106 is preferably equal to the length of the predetermined number of workpieces utilized.
The lower stopper 114 and the upper stopper 106 open and close in an alternating fashion, thereby allowing the insertion of a predetermined number of workpieces per opening and closing cycle. The workpiece travels along the workpiece track 102 and stops at the upper stopper 106 . The upper gate 110 then opens, allowing workpieces to travel past the upper stopper 106 and stop at the lower stopper 114 . The upper gate 110 then closes, stopping any additional workpieces from passing the upper stopper 106 . Now, at least one workpiece, such as a buckle, rests between the upper stopper 106 and the lower stopper 114 . The lower stopper 114 then actuates and raises the lower gate 118 allowing at least one workpiece into the workpiece gripper 200 . The lower stopper 114 then actuates and lowers the lower gate 118 .
Referring now to FIGS. 2, 3 and 4 , a tape fusing member 600 remains at a position above the workpiece gripper 200 . The workpiece gripper 200 includes a rotator section 202 and a workpiece receiver 204 . The workpiece receiver 204 then holds the workpiece for further manipulation. The rotator section 202 moves the workpiece receiver 204 from a position at an end of the workpiece supply path 100 in line with the workpiece track 102 , as further illustrated in FIG. 9 . Therefore, when the lower stopper 114 allows the workpiece to pass, the workpiece slides into the workpiece receiver 204 . The rotator section 202 then rotates the workpiece receiver 204 and the workpiece to a vertical position. The workpiece gripper 200 also includes a first tape folder 206 , a second tape folder 208 and actuators 210 . The actuators 210 move the first tape folder 206 and the second tape folder 208 from a retracted position, as illustrated in FIG. 3, to a protracted position as illustrated in FIG. 4 . The first tape folder 206 includes a first tape folder slot 212 . The second tape folder 208 also includes a second tape folder slot 214 . During operation, the first tape folder 206 and the second tape folder 208 are in a protracted position, the tape fusing member 600 moves to a lowered position directly above the workpiece and directly between the first tape folder slot 206 and the second tape folder slot 208 . FIGS. 4, 12 and 13 further illustrate the tape fusing member 600 in its lowered position. The tape fusing member 600 includes an actuator 602 , a heating element 604 and an upper support structure 606 . The actuator 602 moves the heating element 604 from a position above the workpiece gripper 200 to a position directly between the first tape folder slot 206 and the second tape folder slot 208 .
Referring now to FIGS. 2, 3 , 4 and 5 , a tape feed transfer unit 300 is shown. The tape feed transfer unit 300 includes a base 302 , which allows the tape feed transfer unit 300 to move from a position distant to the workpiece gripper 200 , as illustrated in FIG. 11 to a position near the workpiece gripper 200 , as illustrated in FIG. 10 . The tape feed transfer unit 300 also includes feed rollers 304 , a tape feed guide 306 and a tape feed guide actuator 308 . When the tape feed transfer unit 300 is in a position near the workpiece gripper 200 and while the workpiece gripper 200 holds a workpiece, the feed rollers 304 feed a predetermined length of tape along a tape traveling path 310 and through an aperture 112 a of a workpiece 112 , as illustrated in FIG. 10 . Once a predetermined length of tape 800 extends through the aperture 112 a, the tape feed transfer unit 300 moves to a position distant from the workpiece gripper 200 . The tape feed guide actuator 308 moves the tape feed guide 306 to a lowered position in the tape traveling path 310 . The feed rollers 304 then feed an additional predetermined length of tape 800 which collects in the opening between the tape feed transfer unit 300 and the workpiece gripper 200 . The tape 800 comes from a tape supply section 314 . The tape supply section 314 is well known in the art and can take various forms.
FIG. 6 illustrates the tape feed transfer unit 300 . The actuator 308 extends and moves the tape feed guide 306 in the tape traveling path 310 . Once the tape feed guide 306 is in the tape traveling path 310 , a predetermined length of tape 800 feeds from the feed roller 304 into the opening between the tape feed transfer unit 300 and the workpiece gripper 200 .
FIG. 7 illustrates a cutting device assembly 400 . The cutting device assembly 400 includes a lower cutting device 402 , which may be a blade or cutting block, and an upper cutting device 404 , which may also be a blade or cutting block. The upper cutting device 402 includes a heating element 406 and maintains a temperature high enough to melt a tape or other fastening material. The cutting device assembly 400 may be used to sever a length of material, such as tape. When the tape feed transfer unit 300 , as illustrated in FIGS. 3, 4 , 5 and 6 , is in a position distant to the workpiece gripper 200 , it is lined up for predetermined cutting with the upper cutting device 404 and the lower cutting device 402 . Once the tape feed transfer unit 300 feeds a predetermined length of tape into the opening between the tape feed transfer unit 300 and the workpiece gripper 200 , the upper cutting device 404 and the lower cutting device 402 lower and raise, respectively, to meet, cut and melt tape 800 .
FIG. 8 shows a tape gripping assembly 500 . The tape gripping assembly 500 includes a rotary base 502 , a first tape gripper arm 504 and a second tape gripper arm 506 . The rotary base 502 allows the tape gripping assembly 500 to rotate along arrow 500 a between a first position for working with the tape 800 and a second position for ejecting a completed workpiece (not shown). The first tape gripper arm 504 moves along two dimensions as shown by 504 a and 504 b. The second tape gripper arm 506 moves along one dimension as shown by 506 a. The first tape gripper arm 504 includes opposed members 508 and 510 for gripping a portion of tape near the tape feed transfer unit 300 , as illustrated in FIGS. 5 and 6, and the tape cutter 400 , as illustrated in FIG. 7 . The second tape gripper arm 506 includes opposed members 512 and 514 for gripping a portion of tape above the workpiece, and the workpiece gripper 200 , as illustrated in FIGS. 3 and 4. When the tape gripping assembly 500 is in a first position, the second tape gripper arm 506 extends along a longitudinal direction 506 a and opposing members 512 and 514 grip a portion of tape near the tape feed transfer unit 300 and the tape cutter 400 . At the same time, the first tape gripper arm 504 extends along a longitudinal direction 504 a and opposing members 508 and 510 grip a portion of tape above the workpiece and the workpiece gripper 200 . However, the first tape gripper arm 504 and opposing members 508 and 510 operate in conjunction with the first tape folder 206 and the second tape folder 208 as further illustrated in FIGS. 11 and 13. The first tape folder 206 and the second tape folder 208 protract to fold a tape 800 , as illustrated in FIG. 12 .
As further illustrated in FIG. 13, the first tape gripper arm 504 extends, and opposing members 508 and 510 grip a portion of tape 800 . At that time, the tape fusing member 600 is located directly between the first tape folder 206 and the second tape folder 208 . The opposing members 508 and 510 press the tape 800 into the heating element 604 of the tape fusing member 600 . The opposing members 508 and 510 then release the tape 800 and the first tape folder 206 and the second tape folder 208 retract. At this point, the first tape folder 206 and the second tape folder 208 are in a retracted position. The first tape gripper arm 504 can then extend upward along longitudinal direction 504 a and raise the tape 800 and workpiece 112 out of the workpiece gripper 200 . The second tape gripper arm 506 extends along longitudinal direction 506 a and opposing members 512 and 514 , grip a portion of tape 800 near the tape feed transfer unit 300 and the tape cutting device 400 . At this time, the cutting device 400 operates to cut a portion of tape 800 near the tape feed transfer unit 300 . The tape gripping assembly 500 then turns and ejects the completed workpiece 900 , as illustrated in FIG. 17, from the machine.
General Machine Operation
In one embodiment of the present invention and illustrated by FIG. 9, a workpiece 112 travels along a workpiece supply path 100 along a workpiece track 102 . Workpiece 112 can be automatically fed to the workpiece track 102 by a workpiece supply 104 or manually by an operator. The workpiece 112 first reaches an upper stopper 106 and stops. The upper stopper 106 then allows the workpiece 112 to pass, then shuts again. The workpiece 112 stops at a lower stopper 114 and rests between the lower stopper 114 and the upper stopper 106 . The lower stopper 114 then opens and allows the workpiece 112 to slide into the workpiece receiver 204 of the workpiece gripper 200 .
As illustrated in FIGS. 9 and 10, a rotator section 202 of the workpiece gripper 200 rotates so that the workpiece 112 , now in the workpiece receiver 204 is vertical. The tape feed transfer unit 300 moves to a position near the workpiece gripper 200 . This facilitates the transfer of tape 800 through the workpiece aperture 112 a . Feed rollers 304 feed a predetermined amount of tape 800 through an aperture 112 a of the workpiece 112 along a tape traveling path 310 . The amount of tape 800 fed through the aperture 112 a depends on how much folded tape 800 is required and how far the tape feed transfer unit 300 will move away from the workpiece gripper 200 . As illustrated in FIG. 11, the tape feed transfer unit 300 then moves away from the workpiece gripper 200 . A tape feed guide actuator 308 forces the tape feed guide 306 into the tape traveling path 310 . This forces tape 800 to point in a downward direction. Feed rollers 304 then feed an additional predetermined length of tape 800 which collects in an opening between the tape feed transfer unit 300 and the workpiece gripper 200 . This will provide for an additional length of tape 800 which will extend away from the workpiece 112 . The tape cutter 400 will then sever the tape 800 as illustrated in FIG. 16 .
As illustrated in FIGS. 11 and 12, before the tape feed transfer unit 300 feeds an additional predetermined length of tape 800 , the first tape folder 206 and the second tape folder 208 move to the protracted position, forcing the tape 800 to fold about the workpiece 112 . As illustrated in FIG. 12, the tape fusing member 600 lowers a heating element 604 to a point directly above the workpiece 112 . The first tape gripper arm 504 extends and opposing members 508 and 510 grip a portion of tape 800 through the first tape folder 206 and the second tape folder 208 . At that time, the heating element 604 is located directly between the first tape folder slot 212 and the second tape folder slot 214 . Opposing members 508 and 510 then press the tape 800 into the heating element 604 of the tape fusing member 600 . Opposing members 508 and 510 then release the tape 800 and the first tape folder 206 and the second tape folder 208 retract. Opposing members 508 and 510 then grip a portion of the tape 800 above the workpiece 112 . At this point, the first tape folder 206 and the second tape folder 208 are in a retracted position. This is illustrated in FIG. 14 .
As illustrated in FIGS. 15 and 16, the first tape gripper arm 504 now has a welded portion of tape 800 and can then extend upward along arrow 504 b and raise the tape 800 and the workpiece 112 out of the workpiece receiver 204 . The second tape gripper arm 506 may then extend along arrow 506 a and opposing members 512 and 514 grip a portion of the tape 800 near the tape cutter 400 .
Now, the second tape gripper arm 506 holds a portion of the tape 800 near the tape cutter 400 . The tape gripping assembly 500 then rotates and ejects the completed workpiece 900 from the machine.
The completed strap 900 is shown in FIG. 17 . The completed strap 900 includes a predetermined length of tape 800 , part of which is folded and spot-welded 802 about an aperture 112 a of the workpiece 112 . These completed workpieces 900 can now be used in completing a final product such as backpacks, bags, luggage, life vests, etc.
Although the present invention has been described in detail with particular reference to preferred embodiments thereof, it should be understood that the invention is capable of other different embodiments, and its details are capable of modifications in various obvious respects. As is readily apparent to those skilled in the art, variations and modifications can be affected while remaining within the spirit and scope of the invention. Accordingly, the foregoing disclosure, description, and figures are for illustrative purposes only, and do not in any way limit the invention, which is defined only by the following claims.
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A machine for continuously manufacturing tape strips having at least at one end a portion folded through an aperture of a workpiece is provided. A tape supply section supplies tape to a tape feed unit which is adapted intermittently supply a first predetermined length of tape through an aperture of a workpiece and a second predetermined length of tape not through an aperture. Work pieces are supplied to and received by a workpiece receiving device adapted to hold the workpiece and position the aperture of the workpiece in the tape traveling path. Tape folders operate to fold a tape towards a fusing member positioned above the workpiece. Tape gripping arms further fold a tape into a fusing member. A tape cutter cuts the tape after a second predetermined length of tape is fed from a tape supply section. Tape gripping arms then operate to eject the finished strap from the machine.
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FIELD OF THE INVENTION
This invention relates to coating semiconductor substrates with organic photoresist polymers. In particular, this invention relates to an improved apparatus and process for coating semiconductor substrates with solutions of organic polymers in the presence of volatile solvents, with improved control of volatile solvent emissions from the coating.
BACKGROUND OF THE INVENTION
The manufacture of integrated circuits involves the transfer of geometric shapes on a mask to the surface of a semiconductor wafer. Thereafter, the semiconductor wafer corresponding to the geometric shapes, or corresponding to the areas between the geometric shapes, is etched away. The transfer of the shapes from the mask to the semiconductor wafer typically involves a lithographic process. This includes applying a solution of a pre-polymer solution to the semiconductor wafer, the pre-polymer being selected to form a radiation-sensitive polymer which reacts when exposed to ultraviolet light, electron beams, x-rays, or ion beams, for example. The solvent in the pre-polymer solution is removed by evaporation, and the resulting polymer film is then baked. The film is exposed to radiation, for example, ultraviolet light, through a photomask supporting the desired geometric patterns. The images in the photosensitive material are then developed by soaking the wafer in a developing solution. The exposed or unexposed areas are removed in the developing process, depending on the nature of the radiation-sensitive material. Thereafter, the wafer is placed in an etching environment which etches away the areas not protected by the radiation-sensitive material. Due to their resistance to the etching process, the radiation sensitive-materials are also known as photoresists, and the term photoresist is used hereinafter to denote the radiation-sensitive polymers and their pre-polymers.
The high cost of the photoresist pre-polymer solutions makes it desirable to devise methods of improving the efficiency of the coating process so as to minimize the amount of the polymer solution required to coat a substrate. Furthermore, thickness uniformity of the photoresist layer is an important criterion in the manufacture of integrated circuits. When the radiation is focused through the mask onto the coating, variations in thickness of the coating prevent the precise focus over the entire surface of the wafer which is required to obtain the sharpness necessary to ensure satisfactory reproduction of the geometric patterns on the semiconductor wafer for advanced circuits with line width dimensions approaching 0.25 micron line widths and smaller over a surface.
The solvent in the photoresist tends to evaporate during application, increasing the viscosity of the polymer solution and inhibiting the leveling of the resulting film. This produces thickness non-uniformities. It is therefore desirable to be able to control the rate of evaporation of solvent from the polymer solution during the coating process.
OBJECTS AND SUMMARY OF THE INVENTION
One object of this invention is to provide an improved wafer coating process which yields a greater coating uniformity across the entire surface of each wafer and from wafer-to-wafer.
Another object of this invention is to provide more accurate control of the solvent vapor concentration above the surface of a wafer during the coating and solvent removal phases of the coating process.
It is a still further object of this invention to provide a system for constant monitoring of the vapor concentration above the surface of a wafer, and a feedback control system to change the solvent vapor concentration provided over the surface of the wafer to maintain a predetermined solvent vapor concentration at each moment during the coating and solvent removal phases of the process.
In summary, an apparatus of this invention for spin coating surfaces with liquid polymer comprises a spin coating chamber having a rotatable chuck for supporting an object to be coated. A distributor communicates with the coating chamber and is positioned to introduce gases into the chamber. A solvent vapor and carrier gas supply control means communicates with the distributor. The solvent vapor and carrier gas supply provides a carrier gas having a controlled level of solvent vapor therein within the range of from 0 to saturation concentrations of solvent vapor. A solvent vapor sensor is positioned within the coating chamber to produce signals which are a function of the concentration of solvent vapor in the coating chamber. The control means is connected to the solvent vapor concentration sensor and to the solvent vapor and carrier gas supply means for controlling the level of solvent vapor in the carrier gas supplied by the solvent vapor and carrier gas supply means.
The apparatus includes a coating zone adjacent the rotatable chuck corresponding to the surface to be coated, and the solvent vapor sensor is positioned between the distributor and the coating zone.
The solvent vapor and carrier gas supply means can comprise a solvent vapor supply conduit communicating with the distributor, a carrier gas supply conduit communicating with the distributor, and control valve means positioned with respect to the solvent vapor supply conduit and the carrier gas supply conduit for the purpose of controlling the proportion of gases from the conduits which are supplied to the distributor. Alternatively, the solvent vapor and carrier gas supply means can include a gas supply manifold communicating with the distributor and with the solvent vapor supply conduit and the carrier gas supply conduit, wherein the control valve means is positioned with respect to the manifold, the solvent vapor supply conduit and the carrier gas supply conduit for controlling the proportion of gases from the conduits which are supplied to the distributor.
The manifold can have an inlet, the solvent vapor supply conduit and carrier gas supply conduit can have outlets, and the control valve means can be a valve positioned to simultaneously control flow from each of the outlets. Alternatively, the solvent vapor supply conduit and the carrier gas supply conduit can each have control valves which are positioned to control flow from the conduits to the distributor.
In another embodiment, the solvent vapor and carrier gas supply means includes a distributor manifold, a carrier gas supply conduit communicates with the manifold, and a solvent atomizer with a solvent atomizer pump communicates with the manifold. The control means is connected to the solvent vapor concentration sensor and to the solvent atomizer pump to control the amount of solvent to be atomized by the atomizer into the manifold.
Alternatively, the solvent vapor and carrier gas supply means includes a carrier gas supply conduit communicating with the distributor, and a solvent atomizer with a solvent atomizer pump communicating with the carrier gas conduit. The control means is connected to the solvent vapor concentration sensor and to the solvent atomizer pump for controlling the amount of solvent to be atomized by the atomizer into the carrier gas supply conduit.
The solvent vapor concentration sensor can include a component positioned for exposure to solvent vapor and which has a property which changes as a function of the solvent vapor concentration to which it is exposed. The sensor can include a membrane, the vibrational frequency of which changes as a function of the solvent vapor concentration to which it is exposed; it can include a surface, the electrical properties of which change as a function of the solvent vapor concentration to which it is exposed; or it can detect an acoustical property which is a function of the solvent vapor concentration. The sensor can include an optical detector optically exposed to the solvent vapor, the optical detector sensing an optical property of the solvent which is a function of the solvent vapor concentration. The optical detector can include a spectrophotometer which measures a spectral property of the solvent vapor, such as polarization shift properties, which changes as a function of the solvent vapor concentration.
The method of this invention for spin coating a surface with a polymer in a volatile solvent environment, the coating being applied in the presence of a stream of carrier gas having a controlled concentration of volatile solvent therein, comprises applying the polymer to a surface to be coated in a coating chamber, passing a carrier gas through the coating chamber, the carrier gas having a concentration of volatile solvent for the liquid polymer therein, generating a signal which is a function of the concentration of volatile solvent in the carrier gas by means of a solvent vapor concentration sensor positioned near the surface being coated with the polymer, while carrier gas passes through the chamber, and adding an amount of volatile solvent to the carrier gas in response to the signal to produce a desired concentration of volatile solvent in the control gas passing through the chamber.
The volatile solvent can be added to the carrier gas by mixing together a first gas stream of solvent-free carrier gas and a second gas stream containing solvent vapor at a controlled concentration, the first and second gas streams being mixed in the proportion required to yield a carrier gas having a controlled concentration of solvent vapor therein. A controlled amount of solvent can be atomized in the carrier gas to yield a carrier gas having a controlled concentration of solvent vapor therein.
The solvent vapor concentration sensor positioned in the carrier gas passing through the chamber can include a sensor component positioned for exposure to solvent vapor which has a property which changes as a function of the solvent vapor concentration to which it is exposed. The sensor can be any sensor capable of providing this function. Preferred sensors include an acoustic sensor which changes resonant frequency with solvent concentration and produces a signal proportional to solvent concentration.
The sensor can include a membrane, the vibrational frequency of which changes as a function of the solvent vapor concentration to which it is exposed; it can include a surface, the electrical properties of which change as a function of the solvent vapor concentration to which it is exposed; or it can detect an acoustical property which is a function of the solvent vapor concentration. The sensor can include an optical detector optically exposed to the solvent vapor, the optical detector sensing an optical property of the solvent which is a function of the solvent vapor concentration. The optical detector can include a spectrophotometer which measures a spectral property of the solvent vapor, such as polarization shift properties, which changes as a function of the solvent vapor concentration.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a spin coating apparatus and a solvent vapor feedback control system associated therewith.
FIG. 2 is a schematic drawing of the solvent vapor concentration control system of this invention.
FIG. 3 is a schematic drawing of an alternative gas flow control valve assembly.
FIG. 4 is a schematic drawing of an atomizer spray solvent system for providing a controlled solvent vapor concentration in carrier gas flowing to the coating chamber.
DETAILED DESCRIPTION OF THE INVENTION
The dynamics of viscosity control are affected by the volatile exchange between the photoresist layer and the surrounding atmosphere during the spin-coating process, that is, solvent molecules in the film continue to leave and solvent molecules in the atmosphere are continuously absorbed by the film. Furthermore, some commercial photoresists may contain more than one solvent species, each with its own different vapor pressure profile.
Because of the changing viscosities and surface tensions of solvent-exchanged photoresist film, good planarization requires rapidly adjustable, accurate and reproducible time-profiled solvent-mediated environmental composition control as the polymer film spreads over the wafer surface. Coating thickness control across the wafer and from wafer-to-wafer is measured in angstroms. This process is dynamic, not steady-state. Adjustments and control responses in solvent vapor composition are required in fractions of a second to establish and reproduce the solvent vapor concentration/time profile required for the precision coatings demanded by the next generation of semiconductor devices. This requirement cannot be satisfied using a simple, solvent-saturated atmosphere system or systems designed to provide a simple, constant atmospheric solvent concentration.
The precise solvent concentration in the vapor and respective vapor pressures are under constant control during the spin-coating process by employing a combination of features, all of which contribute to the control. Copending, commonly assigned U.S. application Ser. No. 08/566,227, filed Dec. 1, 1995, describes an apparatus having the ability to introduce a mixture of gas streams, one a solvent-bearing stream and the other a solvent-free stream, to provide adjustment of the solvent vapor in the atmosphere above the substrate. It provides a system for introducing a precise solvent vapor profile during the coating operation based on a predictive model which anticipates the desired solvent vapor level required. It does not take into account, however, the precise contribution of variable solvent evaporation from the coating to the solvent vapor mixture immediately above the wafer.
The present invention combines with the gas stream mixture a sensor and feedback system to measure the solvent vapor concentration over the wafer surface and to provide adjustment to the incoming solvent vapor concentration to achieve the desired solvent vapor concentration, the feedback circuit controlling the ratio of solvent-saturated gas and solvent-free gas to provide to the wafer surface the precise solvent vapor concentration required by the predictive model. This gives a far higher level of precision to the control of the solvent vapor at the wafer surface.
This control can be reproduced wafer-to-wafer to yield a superior, highly reproducible result which has not been achieved prior to this invention. The dynamic ability to constantly and rapidly change the solvent vapor concentration by this technique is a critical aspect of the invention and is not present in the processes of the prior art of record.
FIG. 1 is a schematic view of a spin coating apparatus and a solvent vapor feedback control system associated therewith. The apparatus 2 includes a rotatable support chuck 4 mounted in a spin coating housing 6 and supporting a wafer 5. The chuck 4 is mounted on an axle 8 which passes through an opening 10 in the housing 6. The housing 6 includes solvent vapor and carrier gas supply manifold and dispenser 12. Dispenser 12 introduces a control gas comprising a mixture of a non-solvent gas and a certain concentration of solvent to be passed into the housing 6 above the wafer 5.
Gases are fed into the manifold 12 from gas and solvent supply conduit 14 communicating therewith. A solvent-free gas which is dry, such as air or nitrogen gas, is fed by solvent-free gas conduit 16.
A carrier gas supply conduit 18 with flow control valve 20 communicates with bubbler 26 immersed in a volume of solvent 28 in bubbler chamber 24. A solvent vapor saturated gas stream is prepared by passing gas from gas supply conduit 18 through inlet control valve 20 with valve controller 22 to bubbler chamber 24 with bubbler 26, from which the gases pass upward through solvent 28, emerging as solvent-saturated gas at the temperature set for the solvent. The bubbler 26 in this embodiment can be a porous glass frit from which the gas is passed through the liquid solvent 28. Outlet conduit 30 communicates with the bubbler chamber 24 for receipt of solvent-saturated gas. The gases, saturated with solvent vapor, are removed from chamber 24 through conduit 30. Chamber 24 has a solvent vapor sensor 32 which generates a signal corresponding to the solvent concentration in the vapor. Bubbler chamber 24 is surrounded by a temperature control jacket 34 which contains heating/cooling coils 36 or similar conventional means for maintaining or changing the temperature of the solvent 28 at or to a set point. The gas supply conduit 18 has an optional heater or heat exchanger 37 which controls the temperature of the incoming gas to a set temperature.
The flows of solvent-free gas stream from conduit 16 and solvent-saturated gas from conduit 30 are controlled by the solvent-free gas stream control valve 38 and solvent-saturated gas control valve 40. Valves 38 and 40 can be any standard, conventional remote control valve, such as mass flow controllers, for example.
By respective control of the position of the valves 38 and 40, the respective passageways 16 and 30 can independently be varied from a totally closed position (such as shown for valve 38) to a completely open position (such as shown for valve 40). In this manner, the gas stream fed to manifold 12 can vary from a stream which is completely free from solvent supplied from conduit 16 with valve 38 open and valve 40 closed, to a stream which is saturated with solvent vapor supplied from conduit 30 with valve 38 closed and valve 40 open. Or, the valves 38 and 40 can be opened to any combination of positions to provide a full range of solvent vapor concentrations from 0 percent solvent to fully saturated solvent vapor in the carrier gas stream.
The temperature of the solvent-bearing gas supplied by the bubbler 26 is maintained or controlled to a set point by heating/cooling coils 36 which control the temperature of the solution 28. Alternatively or concurrently, the temperature of the incoming gas supplied by conduit 18 can be raised or lowered or controlled by a heater or heat exchanger 37. Heat must be supplied to the solvent 28 to compensate for heat loss due to evaporation.
Sensor 32, sensor signal processing and control output generator 42, and temperature controller 44 are connected as described hereinafter with regard to FIG. 2. Sensor 32 sends signals to a sensor signal processing and control output generator 42 which, in turn, sends control signals to the temperature controller 44 for controlling the energy or liquid supplied to the heating/cooling coils 36 to change or maintain the temperature of the vessel 24 and the liquid contents 28 to a set temperature point.
The apparatus includes a dispensing head 46 for applying a solution of photoresist pre-polymer to the upper surface of wafer 5. The conventional dispensing head 46 can supply a stream of photoresist solution to the center of the wafer 5 or along a surface from the center to the edge, the rotation of the chuck 4 and the wafer 5 spreading the photoresist over the entire wafer surface by centrifugal action, and spinning off the outer edge any excess photoresist solution.
The gas stream 48 containing the solvent vapor passes in a stream downward and across the upper surface of wafer 5 to control the atmosphere above the wafer surface and thereby control the rate of solvent evaporation from the photoresist coating. The gas flow is quickly drawn over the edge of the wafer, into annular channel 50 and to the exhaust conduit 52 with conventional exhaust valve 54. The exhaust control valve 54 is connected to a valve controller which is connected to the sensor signal processing and control output generator 64, connected thereto as described with respect to FIG. 2. The bottom of the annular channel 50 defines an annular drain channel 58 leading to the photoresist drain conduit 60.
One or more solvent concentration sensors 62 are positioned to determine the solvent concentration in the coating chamber. A preferred sensor position is just above the surface of wafer 5, as shown, but sensors 62 can be optionally positioned in the gas stream 48 leading to and leaving the wafer surface. The sensors 62 are connected to a controller 64, as described in FIG. 2. The controller 64 is connected to valve mass flow controller (MFC) 66 which connects to valves 38 and 40, the connections being shown in greater detail in FIG. 2.
In a typical process, the semiconductor wafer 5 is secured to the chuck 4 using any standard method, such as a vacuum established between the chuck 4 and the wafer 5. A wafer transport door (not shown) to the housing 6 is thereafter closed. The housing 6 is purged with dry solvent-free gas from conduit 16 to purge the chamber. Control gas having a predetermined concentration of solvent vapor is formed by adjustment of valves 38 and 40 to establish the proper ratio of gases from conduits 16 and 30. If complete solvent saturation is desired, for example, valve 38 might be closed and valve 40 opened to introduce a stream of solvent-saturated gas from the conduit 30.
The solvent concentration of the control gas is measured by sensor 62, and adjustments are made to the valves 38 and 40 as required to change or maintain a set level of solvent in the incoming gas stream 48 in a continuous feedback system using the sensor signal processing and control output generator 64 and the mass flow controller 66.
The level of solvent in the carrier gas is adjusted by raising or lowering the temperature of the solvent 28, and optionally, the incoming gas stream from conduit 18 to a temperature level which yields the desired percentage of solvent at full saturation at that temperature. The solvent concentration is measured by sensor 32, and the signal therefrom is used to adjust the temperature of the solution 28, and/or incoming gas from conduit 18, by operation of the sensor signal processing and control output generator 42, temperature controller 44 and carrier gas supply valve controller 22 connected thereto.
In order to deposit a layer of photoresist onto the wafer 5, the polymer solution is applied across the surface of the wafer 5 via the dispensing head 46. This is achieved by dispensing the polymer solution in a continuous stream from a nozzle or similar dispenser (not shown) onto the wafer surface while the wafer 5 is spinning at relatively low speed. In the preferred embodiment, the nozzle is moved substantially radially across the wafer 5. Alternatively, the solution can be dispensed at the center of the substrate, or multiple nozzles can be used. By adjusting the spin speed of the wafer 5, the movement of the nozzle, and the rate at which the polymer solution is dispensed, a suitable distribution of the solution can be achieved. Alternatively, the polymer solution is deposited onto the wafer by means of a film extruder.
The solvent vapor sensors 32 and 62 can be any sensor which is capable of generating a signal having a functional relationship to the percentage of solvent in a carrier gas. One type of suitable chemical vapor sensor is the resonance sensing microelectromechanical system with a solvent absorbent membrane or plate, the resonance frequency of the membrane being a function of the solvent vapor concentration in the vapor. An example of this type of sensor is the Model BMC200 from Berkeley MicroInstruments, Inc. (Richmond, Calif.). The electronic unit powers the sensor and transmits sensor data to the central controller. Another example of a sensor suitable for use in the present invention is the membrane system described in U.S. Pat. No. 5,485,750, the entire contents of which are hereby incorporated by reference.
Other vapor concentration sensors measure the solvent concentration by sensing or measuring electrical (e.g., conductivity, impedance (resistance, capacitance), electrochemical, photoconductivity), optical (e.g., absorption, polarization shift), sound (acoustical) and ultrasonic properties of the gas containing the solvent vapor using conventional, well-known devices for these measurements. Sensors using changes in electrical properties in response to exposure of materials to the solvent vapor are described in U.S. Pat. Nos. 3,579,097; 3,999,122; 4,495,793; 4,572,900; 4,584,867; 4,636,767; 4,638,286; 4,812,221; 4,864,462; 4,874,500; 4,887,455; 4,900,405; 4,926,156; 5,200,633; 5,298,738; 5,372,785; 5,394,735; 5,417,100; and 5,448,906, for example. Optical measurement devices responsive to solvent vapor concentrations are described in U.S. Pat. Nos. 3,796,887; 3,995,960; 4,661,320; 4,836,012; 4,875,357; 4,934,816; 5,030,009; 5,055,688; 5,173,749; 5,381,010; and 5,436,167, for example. Acoustic wave and ultrasonic devices responsive to solvent vapor concentrations are described in U.S. Pat. Nos. 4,312,228; 4,895,017; 4,932,255; 5,189,914; 5,221,871; 5,235,235; 5,343,760; 5,571,944; and 5,627,323, for example. The entire contents of the above-listed patents are hereby incorporated by reference.
FIG. 2 is a schematic drawing of the solvent vapor concentration control system of this invention. The sensor signal processing and control output generator 64 is the hub of the solvent delivery control system. The generator 64 has an input, which is connected to the sensors 62 for receipt of information about the solvent vapor concentration in the coating chamber, and outputs connected to valve controllers 22, 56 and 66 for control of valve 20, which controls the flow of carrier gas to the solvent saturator 24 (controller 22); control of valves 38 and 40, which produce the mix of streams of solvent-free carrier gas and carrier gas (controller 66); and control of the exhaust valve 54 (controller 56), which controls the flow of gases exhausted from the coating assembly.
The hub of the solvent saturator controls is the sensor signal processing and control output generator 42, having an input which is connected to sensor 42 for receipt of signals denoting the solvent concentration in the vapor above the liquid in the tank, and outputs to temperature controller 44 for the heating/cooling coils controlling the temperature of solvent vessel 24 and heat exchanger 37.
FIG. 3 is a schematic drawing of an alternative gas flow control valve assembly. In this alternative configuration, the solvent-free carrier gas supply conduit 68 and the solvent vapor-saturated gas conduit 70 merge to form a single solvent vapor-containing gas supply conduit 72 which communicates with a manifold and dispenser, such as the manifold and dispenser 12 shown in FIG. 1. A pivotal valve 74 pivots on hinge 76, located at the junction of conduits 68 and 70, to rotate about its hinge 76 from a position closing the conduit 68 to a position closing the conduit 70 (shown by dotted line), or to intermediate positions therebetween to partially close one or the other of gas supply conduits 68 and 70. The position of valve 74 determines the proportion of the solvent-bearing gas supplied to the gas distributor. Valve controller 78 connects to a step motor or other conventional control system for positioning valve 74. Valve controller 78 is connected by line 79 to the central sensor signal processing and control output generator, such as the generator 64 shown in FIG. 1.
FIG. 4 is a schematic drawing of an atomizer spray solvent system for providing a controlled solvent vapor concentration in carrier gas flowing to the coating chamber. In this embodiment, only one carrier gas supply conduit 80 communicating with a distributor, such as the distributor 12 shown in FIG. 1, is needed. Atomizer injector 82, which is mounted in the wall of conduit 80, has an outlet communicating with the interior of conduit 80 to introduce a controlled amount or volume of atomized spray of solvent 84 into the carrier gas flowing through the conduit 80. The atomizer 82 is connected by pressurized gas supply conduit 86 with a supply of gas under pressure, which can be a carrier gas for operation of the aspirator. The injector 82 is supplied with liquid solvent by solvent pump 88, connected thereto through adjustable needle valve 90, the pump communicating with a solvent reservoir through solvent supply conduit 92. The pump and injector can be any conventional atomizer and high accuracy flow-controlled pump which are capable of effectively delivering an accurate, controlled flow of solvent into the carrier gas stream. Pump controller 94 is connected to the pump 88 and, by line 96, with the sensor signal processing and control output generator, such as generator 64 shown in FIG. 1. The atomizer 82 is controlled by an output generator to provide a controlled volume of solvent into the carrier gas stream in response to the solvent vapor concentration sensed in the coating chamber, as described above, the principal difference with the embodiments described hereinabove being in the system used to create the solvent and carrier gas mixture. Optional turbulence mixer 98 in conduit 80 disperses the solvent vapors throughout the carrier gas flowing therethrough.
This invention provides an adaptive control of solvent concentration with the process chamber used for spin coating of polymers such as photoresist in the area of photolithography. The invention provides an improved mean thickness and uniformity control for polymer film processes employed during the manufacture of small feature size advanced devices.
The vapor pressures of most organic solvents are strongly dependent upon solvent type and temperature. Temperature sensitivities for vapor pressures of ethyl lactate, propylene glycol monomethyletheracetate (PGMEA), and acetone are 0.17 Torr/°C., 0.16 Torr/°C., and 9.4 Torr/°C., respectively. As a result, in order to control the concentration of solvent introduced into a process chamber, one needs to control solvent temperature accurately. In addition, the solvent concentration delivered to a chamber is dependent on the amount of head room space above the liquid level within the solvent canister. All of these factors limit the control of the solvent concentration within the process chamber, causing serious problems with the production of repeatable film thickness profiles during spin coating.
This invention uses one or more solvent vapor sensors to measure solvent concentration. The output of the sensors is used to control mass flow controllers in real time by way of an algorithm. Sensors are placed in the process chamber, solvent canister, and/or optionally, in any pathway therebetween. Any fluctuation in solvent temperature or headroom space which may cause variation of the solvent concentration inside the process chamber can be compensated by mass flow controllers in a closed loop fashion to ensure constant and repeatable solvent atmospheres for every wafer processed. Decision-making is done by a process control algorithm which uses known chemical properties of the solvent, required process conditions and numerical models.
This invention can reduce dependence on precise temperature controls for the solvent to achieve the desired solvent concentration in the coating chamber. The invention can be applied to different systems for introducing the solvent vapor, such as the bubbler system disclosed or a liquid mass flow controller combined with an atomizer, which is also considered to be within the scope of this invention. This invention makes solvent concentration control within a process chamber totally transparent to the user.
It will be readily apparent to those skilled in the art that this invention is not limited to the embodiments described above. Different configurations and embodiments can be developed without departing from the scope of the invention and are intended to be included within the scope of the claims.
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An apparatus for spin coating surfaces with liquid polymer comprises a spin coating chamber having a rotatable chuck for supporting an object to be coated. A distributor introduces gases into the chamber. A solvent vapor and carrier gas supply provides a carrier gas having a controlled level of solvent vapor therein within the range of from 0 to saturation concentrations of solvent vapor. A solvent vapor sensor is positioned with respect to the coating chamber to produce signals which correspond to the concentration of solvent vapor in the coating chamber. A control means is connected to the solvent vapor concentration sensor and to the solvent vapor and carrier gas supply means for controlling the level of solvent concentration in the carrier gas supplied by the solvent vapor and carrier gas supply means. The solvent vapor level can be obtained by controlled mixing of solvent-bearing and solvent-free gas streams, or by injection of solvent into a gas stream by means of an atomizer, for example. The solvent vapor concentration sensor includes a component positioned for exposure to solvent vapor and which has a property which changes as a function of the solvent vapor concentration to which it is exposed. A preferred sensor can include a membrane, the vibrational frequency of which changes as a function of the solvent vapor concentration to which it is exposed; a surface, an electrical property of which changes as a function of the solvent vapor concentration to which it is exposed; a sensor which detects an acoustical property which changes as a function of the solvent vapor concentration to which it is exposed; or an optical detector which detects an optical property which changes as a function of the solvent vapor concentration to which it is exposed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of digital communications. More particularly, this invention relates to the field of digital communications having requirements for derivation of synchronization from the digital signal and the problems associated with maintaining synchronization in such a system during period of long strings of zeros or low ones density.
2. Background
To meet CCITT Recommendation G.703, (and Bell Publication 62411), T1 communication devices are required to send no more than 15 consecutive zeros in their data stream and must have a minimum ones pulse density of 12.5%. This requirement allows the telephone company's equipment to maintain synchronization. Long strings of consecutive zeros can cause many problems. For example, such long strings of zeros can cause T1 repeater equipment to lose synchronization. A scheme for limiting the length of strings of consecutive zeros is therefore necessary for present digital networks. Among the most important factors in a zero limitation scheme are the use of a minimum of bandwidth as overhead, and keeping the hardware and/or software implementation simple.
In today's networks, 1 out of 8 bit stealing is a method in use that prevents the transmitting of more than 15 consecutive zeros in a data stream. This method is performed simply by setting 1 bit out of every byte, thereby using one-eighth of the users bandwidth. It is the among the simplest available schemes for consecutive zero limitation, but the high overhead seriously impacts data throughput making it undesirable.
Another method of zero limitation involves detecting 15 consecutive zeros, and when there are 15 consecutive zeros the next bit must always be set. Some of the users bandwidth can be reserved to hold the actual 16th bit when this happens. The number of bits reserved for this purpose will give the number of occurrences of 15 consecutive zeros that can be handled without causing a bit error. Errors may still occur using this method if the overhead is less than 6.25%. To apply this method, scramblers, parallel to serial converters, and serial to parallel converters are needed to guarantee a ones density of at least 12.5%.
In September 1981, AT&T announced a method termed Bipolar Eight Zero Substitutions (B8ZS) which provides a clear channel for the primary rate. B8ZS inserts deliberate bipolar violations to permit transmission of zero bytes while providing sufficient pulse density For the repeater equipment and T1 source/sink devices.
ZBTSI, which stands For Zero Byte Time Slot Interchange, is an alternate solution to the problem. It appeared in a contribution to the CCITT standards committee T1X1.4 as a candidate to become a standard. It requires only a small amount of overhead (1 bit For a 127 byte frame), and it requires a smaller investment, from a network viewpoint, than B8ZS. A detailed comparison of ZBTSI and B8ZS is found in G. J. Beveridge et al, "Line Code Formats for ISDN Clear Channels: Stand Alone vs. Integrated Network Solutions", Document No. T1X1.4/85 CB, July 26, 1985.
The present invention, termed the Zero Byte Address Linked List method (ZBALL) is a modification of ZBTSI, that has the same advantages of ZBTSI over B8ZS. ZBALL makes some improvements over ZBTSI in the following respects. ZBALL can use the full 128 addresses available in a byte-wide system, ZBTSI can have a maximum of only 127 bytes per frame. In some cases, For example X.25, a 128 byte (1024 bit) packet size becomes important. ZBTSI may be much more difficult than the present invention to implement in hardware since it involves shifting the location of the bytes in a frame. There is no shifting of bytes in ZBALL, just replacement of the byte's contents.
SUMMARY OF THE INVENTION
The present invention solves the above problems by creating a "frame", and then sending the address of byte locations where zeros occur in the frame, instead of the zeros themselves. The address of the first zero byte is placed in the first byte of the frame. The address of the second zero byte is placed in the first zero byte. The address of the next zero byte is placed in the previous zero byte, and so on, until the end of the frame is reached. Once all of the zero bytes are found, the first byte is put into the last zero byte. One bit is reserved in each zero byte to signify if further addresses exist, giving 128 bytes as the maximum frame size. One flag bit is needed to signify that at least one zero byte is in the frame.
Some of the main advantages to this scheme are that only a minimum of overhead is needed, it will not cause any bit errors for any input data, and it will be comparable, if not easier to implement, than other schemes. Also, the new method can provide 128 byte frames, (1024 bits per frame), whereas, ZBTSI can only provide 127 bytes per frame. And, since there is no byte shifting involved, the present invention is easier to implement than ZBTSI. This is especially true when the system is required to operate at high data rates.
Accordingly, it is an object of the present invention to provide an improved method of providing a clear channel in digital communication equipment.
It is another object of the present invention to provide an improved method of providing clear channel which allows transmission of a 128 byte frame.
It is another object of the present invention to provide an improved method of providing clear channel which is simple to implement.
These and other objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the following description.
In one embodiment of the present invention, an improved method of encoding data into a frame, includes the step of providing a frame having a plurality of byte locations for storing a plurality of bytes each associated with one of the byte locations. The value of the initial byte location of the frame is stored in a temporary register. An address of a first byte location having zero value (excluding the initial byte) is stored in the initial byte location of the frame. A continuation bit associated with the address of said first byte location is set. The value of the initial byte is stored in the first byte location. The non-zero valued bytes of information are stored in their associated byte locations of the frame.
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to organization and method of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an example of how a ZBALL frame is encoded.
FIG. 2 illustrates an example of how a ZBALL frame is encoded when a zero appears as the first word in the frame.
FIG. 3 is a flow chart of the ZBALL encoding process.
FIG. 4 is a flow chart of the ZBALL decoding process.
DESCRIPTION OF THE INVENTION
In order to facilitate description of the present invention, the ZBALL encoding process will be explained in terms of examples using a 128 byte frame. However, it should be clearly understood that ZBALL will operate on nibbles, bytes, words or any n-bit wide system (for n>2) that requires a limitation on the number of consecutive zeros it can transmit. For purposes of this discussion, the terms `byte` and `word` should be liberally interpreted to include nibbles, words, groups of words, groups of nibbles or groups of bits as any of the above may be utilized in practicing the present invention according to the requirements of the particular system. For purposes of this discussion, `byte` and `word` are not to be limited in meaning to the conventionally accepted definition of an eight (or sixteen or thirty-two, etc) bit binary word. The specific embodiment disclosed as an example will guarantee that no more than 15 consecutive zeros will be transmitted and there are at least 12.5% ones. This conforms to the requirements of a T1 link. Those skilled in the art will appreciate that the present invention may be suitably modified to meet other requirements.
In ZBALL an address is sent in the place of an n-bit wide zero string occurring in a "frame" of some number of n-bit wide words, instead of the word itself. Each n-bit address of a zero word reserves a "continuation" bit to signify that another n-bit address of a zero word remains, thus giving 2.sup.(n-1) usable addresses in an n-bit wide system. The maximum number of bits that can be processed at one time by ZBALL for an n-bit wide system is:
MAX BITS=2.sup.(n-1) ×n
In a one byte wide system with 8 bits per byte, the maximum number of bits that can be processed at a time is:
MAX BITS=2.sup.(8-1) ×8=1024 bits
and the maximum frame size (#of addresses) for a one byte-wide system is:
MAX FRAME=2.sup.(8-1) =128, bytes
A flag bit is used to signify that the ZBALL operation has been performed on a frame. This flag bit is all the overhead that is needed to perform ZBALL. A bit may be reserved in the packet header for this purpose. Other systems could either reserve a bit, or for instance, in T1 systems, the framing bit may be utilized as in ZBTSI. In an eight bit wide system with a maximum frame size of 128 bytes, only 7 bits are required to uniquely define each byte address, therefore, an eighth bit may be used as a continuation bit.
The ZBALL process is explained below using as an example a byte-wide system.
ZBALL ENCODING PROCEDURE
The ZBALL frame starts from byte location zero (the initial byte in the frame). The frame may be up to 128 bytes in length, starting with byte 0, and ending with byte 127. A flag bit signifies whether or not the frame includes any zero bytes. This flag bit may be part of the user's frame or may be sent separately, for example as in ZBTSI. The first step after determining that a flag bit is present, is to store the data of byte 0 in a temporary register. The next step in the process is to search for zero bytes, starting with byte 1 of the frame. After the first zero byte is found, the address of the first zero byte is put into byte zero. The search for zero bytes continues. The address of each zero byte input into the previous zero byte, and the continuation bit is set in the previous zero byte. This process continues until the last zero byte has been found and the end of the frame is reached.
The contents of byte 0, which is in the temporary register, is then placed into the last zero byte. The previous continuation bit remains cleared. A flag is set to show this frame had at least one zero byte. During the entire encoding procedure, all non-zero bytes, except for byte 0 are unaffected. If there were no zero bytes in the frame, the frame is unchanged, and the flag bit remains cleared.
In practice, those skilled in the art will recognize that the process may be more efficiently done by initially setting all continuation bits and later clearing the last one. However, the explanation is simplified by describing the process as above. Either technique is acceptable and equivalent.
EXAMPLE 1
Referring now to FIG. 1, an example of ZBALL encoding is shown. For this example, assume a frame size of 128 bytes has been selected, and that a particular frame contains zero valued bytes in byte number 8, 10, 19 and 27. The ZBALL encoding operation would be as follows:
(1) The contents of byte 0 is stored in "R" (a temporary register).
(2) The address of the first zero byte 8, is stored in byte 0.
(3) Ten is stored in byte 8, and the continuation bit is set byte 0.
(4) 19 is stored in byte 10, and the continuation bit is set in byte 8.
(5) 27 is stored in byte 19, and the continuation bit is set in byte 10.
(6) The "R" register is loaded into byte 27. The continuation bit of byte 19 is not set.
(7) None of the other bytes are affected. The flag is set to show that this frame has at least one zero byte.
It should be noted, as is evident from the FIG. that each byte may contain either 8 bits of data or a 7 bit address plus 1 continuation bit after ZBALL encoding. As previously explained, it is more efficient to actually set all continuation buts and then clear the last one.
If byte 0 is a zero byte, then the frame is treated as a special case. In this case, the last continuation bit is set, and the last zero byte address is placed in the last zero byte. This repetition of the last zero byte address will signify that the special case has occurred.
EXAMPLE 2
ZERO IN FIRST BYTE
Turning now to FIG. 2, an example of ZBALL is shown in which the first byte contains all zeros. Again assume a frame size of 128 bytes has been selected, and that a particular frame contains zero bytes in positions 0, 5, 16, 24 and 29. The ZBALL encoding operation would be as follows:
(1) The contents of byte 0 (all zeros) is stored in "R".
(2) The address of the first zero byte (starting from byte 1), 5, is stored in byte 0.
(3) 16 is stored in byte 5, and the continuation bit is set in byte 0.
(4) 24 is stored in byte 16, and the continuation bit is set in byte 5.
(5) 29 is stored in byte 24, and the continuation bit is set in byte 16.
(6) 29 is also stored in byte 29, and the continuation bit is set in byte 24.
(7) The continuation bit of byte 29 is set. (The reason For this will be explained later). The flag bit is also set.
There is also a very special case that can occur. Byte zero could be the only zero byte of the entire frame. In this case, the final ZBALL result is that the flag bit is set, and byte zero is sent as [1,0000000]. It is for this reason that if byte 0 is a zero byte, the final continuation bit must always be set according to the preferred embodiment. This avoids sending a zero byte, if byte 0 was the only zero byte of the frame. There are no other effects on the original frame. This is the reason that in the above example the continuation bit of byte 29 was set.
A complete flow chart to implement the encoding procedure for a 128 byte frame is shown in FIG. 3. Those skilled in the art will readily appreciate that this process is readily modified to accommodate other size frames. In this flow chart, the following variables are used:
I=pointer or index for word locations in a frame of data words.
D(I)=the data content of the Ith word in the frame
T,Y,Z=temporary storage registers.
A(I)=address of Ith data word.
C(I)=continuation bit for Ith address.
F=flag bit for frame indicating that at least one zero word is present in the frame.
Turning now to FIG. 3, the process begins at step 20 after which I is initialized to 1 at step 22. At step 24, the contents of the first data location D(0) is loaded into the T register and 0 is loaded into the Y register. Control then passes to decision block 28 where the data at the ith location D(I) is compared with zero. If D(I)=0 then control passes to 30 where the address of the Ith word A(I) is loaded into data location D(Y); I is loaded into C(Y) (that is the continuation bit is set); and 1 is loaded into F (the flag which indicates that the frame contains at least one zero is set).
Next, control passes to step 34 where the previous zero address location Y is loaded into the Z register and the current zero address I is loaded into the Y register. Control then passes to step 36. In the event D(I) is not zero at step 28, control passes directly to step 36 bypassing steps 30 and 34. At step 36, the counter I is incremented by 1 and control passes to step 40. At step 40 the value of I is compared to 127. If I>127 then control passes to step 44 else control passes back to step 28.
At step 44, the T register is checked to see if it contains zero indicating that the first byte was equal to zero. If so, control passes to step 46 where the contents of the Y register is loaded into D(Y); 1 is loaded into F (the flag is set) and C(Y) is loaded with 1 (the continuation bit is set). The routine terminates for the current frame at step 48 after step 46.
If the T register does not contain zero at step 44, control passes to step 52 where the flag is inspected. If the flag is not set, control passes to step 48 and the routine terminates. If the flag is set, control passes to step 56 where T is loaded into D(Y) (the first byte of data is loaded into the last zero valued byte position) and zero is loaded to C(Z) (no continuation bit).
When no zeros are found, this routine executes loop 28-36-40-28. When a zero is found, it is processed in loop 28-30-34-36-40-28.
The above routine illustrates the ease of implementing the encoding process. No shifting of data is required and only 3 one word registers plus the memory for the frame are needed to implement it. Of course those skilled in the art will appreciate that other techniques may exist to implement the present invention and the present invention as shown in FIG. 3 may take on various embodiments. For example, both hardware and software (firmware) embodiments may be implemented using the flow chart of FIG. 3. In hardware embodiments, the reassignments shown in steps 24, 30, 34, 46 and 56 may be executed in parallel while software embodiments will likely implement these reassignments in series.
ZBALL DECODING PROCEDURE
In order to decode a frame, first the flag bit must be checked. If the flag is cleared the frame is passed through unchanged, but if it is set, the frame must be decoded. The following procedure will locate the zero bytes. The address of the first zero byte can be found in byte 0. The address of the next zero byte will be found in the previous zero byte. The procedure will terminate in two cases. The first case is when the continuation bit is cleared, in this case the data of the last zero byte is placed in byte 0. The second case is when the continuation bit is set, but the address of the next zero byte is equal to the current address. In this case, byte zero is made all zeros.
A complete flow chart to implement the decoding procedure is shown in FIG. 4. This flow chart additionally uses the following notation:
S, N=temporary storage registers.
It should be noted that the S register has a bit location reserved for a continuation bit and 7 bit locations for address information.
Turning now to FIG. 4, the decoding routine is entered at step 100. At step 102, the frame flag F is inspected. If the flag F is not set, the routine terminates at 106 indicating that no zeros were present in the frame. Else, control passes to step 108 where I is initialized to 0. Control then passes to step 110 where the contents of D(0) is loaded into the temporary register S. Control then passes to decision block 118 where Iis inspected to determine if it is equal to S (the address of the first zero valued byte). If not, control passes to step 119 where I is incremented by 1 and then back to step 118. The counter is repeatedly incremented in this manner until I>S in 118. At this point, the value of D(S) is loaded into the N register at step 120.
Control then passes from 120 to 124 where the continuation bit is inspected. If the continue bit C(I) is not set (equal to 0), indicating that no more zeros are present in the frame, control passes to step 128 where 0 is loaded into D(S) and N is loaded into D(0). The routine then terminates at 106.
If the continuation bit is set at step 124, control passes to step 132 where S is compared to N to determine if the last zero byte has been processed (S=N). If so, control passes to step 138 where 0 is loaded into D(S) and 0 is loaded into D(0). The routine then terminates at step 106.
If S is not equal to N at step 132, control passes to step 140 where 0 is loaded into D(S) and control passes to step 144. At 144, N is loaded into S and B(S) is loaded into N. Control then passes to step 148 where I is incremented. Control is passed to step 150 where I is compared with S. If I is not equal to S then control passes back to 148 where I is repeatedly incremented until I=S. When I=S the process goes back to step 124. The loop 124-132-140-144-148-150-124 represents the process of processing more zero valued bytes. Remarks similar to those regarding variations of FIG. 3 are similarly applicable to FIG. 4.
The present invention may implemented by use of a programmed processor such as a microcomputer programmed according to the flow charts of FIG. 3 and FIG. 4, but this is not to be limiting as those skilled in the art will appreciate that hard wired logic circuit equivalents may be developed which also operate according to those flow charts. Such hard wired logic equivalents may have advantages over a programmed general purpose processor implementation of the present invention in some instances. For example, circuit size and cost may be lower in large volumes when the circuitry is implemented as a custom or semi-custom integrated circuit. Reliability may be similarly enhanced due to reduced part count for such hard wired implementations.
ZBALL can provide a viable alternative to both ZBTSI and B8ZS as a standard line code format which supports clear channel capacity. ZBALL also meets end-user requirements to transmit unrestricted data through a network not capable of handling the bipolar violations required by B8ZS. Those skilled in the art will recognize that the above examples are intended only to be illustrative of the present invention. The invention itself, however, may take on many alternatives and variations as will occur to those skilled in the art.
Thus it is apparent that in accordance with the present invention, a method that fully satisfies the aims, advantages and objectives is set forth above. While the invention has been described in conjunction with with specific embodiments, it is evident that many alternatives, modifications and variations will become apparent to those skilled in the art upon consideration of the forgoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.
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A method of encoding data into a frame, includes the step of providing a frame having a plurality of byte locations for storing a plurality of bytes each associated with one of the byte locations. The value of the initial byte location of the frame is stored in a temporary register. An address of a first byte location having zero value is stored in the initial byte location of the frame. A continuation bit associated with the address of said first byte location is set. The value of the initial byte is stored in the first byte location. The non-zero valued bytes of information are stored in their associated byte locations of the frame. When the initial byte location contains zero, the last location containing an address of a zero valued byte repeats the previous address having a zero valued byte.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Phase Entry of International Application No. PCT/EP2008/050888, filed on Jan. 25, 2008, which claims priority to French Patent Application No. 0753050, filed on Feb. 2, 2007, both of which are incorporated by reference herein.
BACKGROUND
The present invention relates to genetically modified yeasts for producing glycoproteins having optimized and homogeneous glycan structures. These yeasts comprise inactivation of the Och1 gene, integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a first promoter, and an open reading phase comprising the sequence coding for an α-1-2 mannosidase I, and integration of a cassette comprising a second promoter different from said first promoter and the sequence coding for an exogenous glycoprotein. These yeasts allow production of EPO with optimized and homogeneous 98% glycosylation.
The production of glycoproteins or glycopeptides having glycans of the complex type, i.e. structures identical with oligosaccharides added during post-translational modifications in humans, has been a sought goal for quite a few years in the pharmaceutical industry. Indeed, many studies have shown the importance of oligosaccharides for optimizing the activity of therapeutic glycoproteins or further for improving their half-life time once they are administered. For example, human erythropoietin (HuEPO) is a glycoprotein of 166 amino acids containing three N-glycosylation sites in positions Asn-24, Asn-38 and Asn-83 and an O-glycosylation site of the mucin type in position Ser-126. EPO is a particularly relevant model for studying N-glycosylation because of its glycosylated structures representing 40% of its molecular weight. The EPO molecule considered as natural is the urinary form (uHuEPO) (Takeuchi et al., 1988, Tusda 1988, Rahbeck-nielsen 1997). Recombinant EPO (rHuEPO) is presently produced in CHO cells (Sasaki H et al., Takeuchi et al., 1988) or in BHK cells (Nimtz et al., 1993). The rHuEPOs expressed in cell lines have N-glycan structures different from the structures found in uHuEPO. These differences may have repercussion in vitro (Higuchi et al., 1992; Takeuchi et al., 1990) but seem to be more sensitive in vivo by a drastic loss of activity for the deglycosylated forms and by an increase of activity correlated with the number of sialic acids present on the structure (Higuchi M et al., 1992).
In order to produce glycoproteins having optimum N- or O-glycosylation, many technical solutions have been proposed. Mention may be made of in vitro modifications of glycan structures by adding sugars such as galactose, glucose, fucose or even sialic acid by means of different glycosyl transferases or by suppressing certain sugars such as mannose with mannosidases. This technique is described in WO 03/031464 (Neose). It is however possible to wonder how such a technique may be applied on a large scale since this involves many steps for sequential modification of several given oligosaccharides present on a same glycoprotein. In each step, strict control of the reaction should be carried out and production of homogeneous glycanic structures should be ensured. Now, in the case when many oligosaccharides have to be modified on a glycoprotein, a sequential reaction may result in undesirable and heterogeneous modifications. This technique is therefore not compatible with the preparation of biodrugs. Further, the use of purified enzymes for production on an industrial scale does not seem to represent a viable economical alternative.
The same applies with chemical coupling techniques, such as those described in documents WO 2006/106348 and WO 2005/000862. These chemical coupling techniques involve tedious reactions, protection/deprotection steps, multiple checks. In the case when many oligosaccharides have to be modified on a given glycoprotein, a sequential reaction may also result in undesirable and heterogeneous modifications. Other technologies using mammal cell lines such as YB2/0 described in WO 01/77181 (LFB) or further CHO lines genetically modified in WO 03/055993 (Kyowa) have demonstrated that slight fucosylation of the Fc region of the antibodies improves ADCC activity by a factor 100. However, these technologies specifically relate to the production of antibodies.
Finally, production of glycoproteins in yeasts or filamentous fungi has been proposed by transformation of these micro-organisms with plasmids allowing expression of mannosidases and of different glycosyl transferases. This approach was described in WO 02/00879 (Glycofi). However, to this day, it has not been demonstrated that these micro-organisms are stable over time in a high capacity fermenter for producing clinical batches. Also, it has not been shown that this transformation enables production of glycoproteins with the desired and homogeneous glycans.
With the purpose of producing rHuEPO having N-glycan structures with which optimum activity may be obtained in vivo, we expressed an rHuEPO in genetically modified S. cerevisiae and S. pombe yeasts. These yeasts showed strong expression of rHuEPO having homogeneous and well-characterized N-glycosylation units. In a second phase, we started with genetically modified yeasts and we incorporated other modifications in order to produce more complex N-glycan units, depending on their sialylation levels. The yeast system is known for its capacity of rapidly producing a large amount of proteins but the modified yeasts described hereafter are also capable of N-glycosylation of the produced proteins in a “humanized” and homogeneous way. Further, these yeasts are found to be stable under conditions of production on a large scale. Finally, in the case of mutations leading to genotype reversion, these yeasts are constructed so as to allow them to be restored identically, which is required within the scope of producing clinical batches.
Thus, this is the first example which illustrates targeted integration methods in particular loci which have been used for the whole of the invention, methods allowing control of interrupted and selected genome regions to within one nucleotide, and therefore allowing restoration of the interruption in the case of spontaneous genome reversion. This method should be opposed to the one described in WO 02/00879, consisting of transforming a yeast strain with a bank of sequences and subsequently selecting the best clone without any genomic characterization. Indeed, in WO 02/00879 the integrations are random and the clones are exclusively selected on the basis of the profile of N-glycan structures of the produced proteins, which involves, in the case of mutations, reversion or any other genetic modification, pure and simple loss of the clone of interest. The advantage of the technology according to the invention is to provide increased safety to the user, by providing him/her with a guarantee of controlling, tracking genetic modifications, and especially the possibility of reconstructing a clone which will strictly have the same capacities.
Further, for the first time we provide a “Glycan-on-Demand” technology from the Amélie strain as described hereafter. Under these conditions, the homogeneity of the structures is more important than in the CHO systems which glycosylate like mammals. Indeed, the obtained results (see EPO spectrum), report a glycan structure of the Man5GlcNAc2 type representing about 98% of the N-glycans present on the protein. The system is therefore designed so as to force glycosylation in order to obtain a desired unit in very large proportion. The Amélie strain is the clone used as a basis for elaborating any other strain intended to produce humanized, hybrid or complex glycans, which one wishes to obtain. The advantage of this strain is to form a starting point, which was demonstrated as being a stable and homogeneous system producing 98% of Man5GlcNAc2 glycoproteins, which may be reworked for additional modifications such as the introduction of a GlcNAc transferase, of a fucosyl transferase, of a galactosyl and/or sialyl transferase, on demand, rapidly, according to the desired final structures.
SUMMARY
The construction of an expression cassette is carried out by integrating a promoter sequence in position 5′ and a terminal sequence in position 3′ of the ORF. On the other hand, the integration of these cassettes into the genome of the yeasts is controlled by adding to the ends, sequences homologous to the target locus with the purpose of integration by homologous recombination. For each strain and for each ORF, the promoter sequences as well as the integration sequences, have been determined with the purpose of obtaining stable and optimum expression of the different enzymes allowing homogeneous glycosylation of glycoproteins. The construction of an expression cassette is accomplished in several successive pCR steps, according to this general model shown in FIG. 2 (assembly PCR for constructing expression cassettes of the ORFs). Certain ORF sequences have been partly modified by integrating sub-cellular localization signals in order to express (address) the protein in a compartment where its activity will be optimum (environment, presence of the donor, and of the substrates, etc. . . . ).
Thus, in a first aspect, the present invention relates to genetically modified yeasts, capable of producing glycoproteins having homogeneous glycans having the structure Man5GlcNAc2, said yeasts comprising the following modifications:
a) inactivation of the Och1 gene coding for α-1,6-mannosyl transferase by insertion by homologous recombination of a heterologous sequence coding for a gene of resistance to an antibiotic (kanamycin) (delta-Och1 strain), b) integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter selected from pGAP, pGAL1, PGK, TEF, adh1, nmt 1, SV40, PMA1, CaMV, pet56 of S. cerevisiae or S. pombe , and ADH2 having the sequence SEQ ID Nos. 16-26 respectively, an open reading phase comprising the sequence coding for an α-1-2-mannosidase I comprising a targeting sequence in the endoplasmic reticulum or the Golgi apparatus and a terminator of the transcription, c) integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter selected from pGAP, pGAL1, PGK, TEF, adh1, nmt 1, SV40, PMA1, CaMV, pet56 of S. cerevisiae or S. pombe , and ADH2 having the sequence SEQ ID Nos. 16-26 respectively, said promoter in c) being different from the promoter in b); an open reading phase comprising the sequence coding for an exogenous glycoprotein to be produced and a terminator of the transcription.
Preferably, the yeasts described above have integrated α-1-2 mannosidase I of C. Elegans , notably a sequence comprising SEQ ID NO 1. These yeasts are found to be capable of producing glycoproteins having 98% of Man5GlcNac2 glycans:
Advantageously, α-1-2 mannosidase I is expressed under the control of the promoter pGAP and the exogenous protein glycoprotein is expressed under the control of the promoter pGAL1. In the following description, reference will be made to the abbreviations used in the state of the art Man=mannose, GlcNac=N-acetyl-glucosamine, Gal=galactose, Fuc=fucose and NANA designating sialic acid or further N-acetyl-neuraminic acid.
In a second aspect, the yeasts of the invention include additional modifications in order to produce glycoproteins having more than 75%, or even 80% or further 95% or 98% of the GlcNacMan5GlcNAc2 structure:
For this purpose, the above strains further comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter selected from pGAP, pGAL1, PGK, TEF, adh1, nmt 1, SV40, PMA1, CaMV, pet56 of S. cerevisiae or S. pombe , and ADH2 having the sequence SEQ ID Nos. 16-26 respectively, an open reading phase comprising the sequence coding for human N-acetyl-glucosaminyl transferase I, comprising a targeting sequence in the endoplasmic reticulum or the Golgi apparatus and a terminator of the transcription. Preferably, human N-acetyl-glucosaminyl transferase I comprises the sequence SEQ ID NO 2 without the cytoplasmic portion of the enzyme which is replaced with the cytoplasmic portion of Mnn9 for Golgian localization of the protein. This strain is designated as “Arielle”. Arielle should also contain the GlcNAc UDP transporter cassette (described below) in order to synthesize this type of glycan. Advantageously, the promoter pGAP is used.
Mnn9
(SEQ ID NO 13)
Atgtcactttctcttg
tatcgtaccgcctaa
gaaagaacccgtgqgttta
ac : cytoplasmic portion.
The Amélie strain above may further comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter pGAP, pGAL1, PGK, TEF, adh1, nmt 1, SV40, PMA1, CaMV, pet56 of S. cerevisiae or S. pombe , and ADH2 having the sequence SEQ ID Nos. 16-26 respectively, an open reading phase comprising the sequence coding for the cassette for the human UDP-GlcNAc transporter and a terminator of the transcription. Preferably, the human UDP-GlcNAc transporter comprises the sequence SEQ ID NO 3. Preferably the promoter is PGK. This strain is designated hereafter as “Agathe”.
In a third aspect, the yeasts of the invention include additional modifications in order to produce glycoproteins having more than 75%, or even 80% or further 95% or 98% of the GlcNacMan3GlcNAc2 structure:
As such, the Arielle yeasts mentioned above comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter selected from pGAP, pGAL1, PGK, TEF, adh1, nmt 1, SV40, PMA1, CaMV, pet56 of S. cerevisiae or S. pombe , and ADH2 having the sequence SEQ ID Nos. 16-26 respectively, an open reading phase comprising the sequence coding for a mannosidase II comprising a targeting sequence in the endoplasmic reticulum or the Golgi apparatus and a terminator of the transcription. Preferably, mannosidase II is that of mice, notably a sequence comprising SEQ ID NO 4. Preferably the promoter is TEF. This strain is designated hereafter as “Anaïs”.
In a fourth aspect, the yeasts of the invention include additional modifications in order to produce glycoproteins having more than 75%, or even 80% or further 95% or 98% of the GlcNac2Man3GlcNAc2 structure:
In this case, the Anaïs yeasts mentioned above comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter selected from pGAP, pGAL1, PGK, TEF, adh1, nmt 1, SV40, PMA1, CaMV, pet56 of S. cerevisiae or S. pombe , and ADH2 having the sequence SEQ ID No 16-26 respectively, an open reading phase comprising the sequence coding for an N-acetyl-glucosaminyl transferase II, comprising a targeting sequence in the endoplasmic reticulum or the Golgi apparatus and a terminator of the transcription. Preferably, the N-acetyl-glucosaminyl transferase II is human, notably a sequence comprising SEQ ID NO 5. Preferably the promoter is PMA1, this strain is designated hereafter as “Alice”.
In another embodiment, the Alice yeasts of the invention include additional modifications in order to produce glycoproteins having more than 75%, or even 80% or further 95% or 98% of the Gal2GlcNac2Man3GlcNAc2 structure:
In this case, the Alice yeasts mentioned above comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter selected from pGAP, pGAL1, PGK, TEF, adh1, nmt 1, SV40, PMA1, CaMV, pet56 of S. cerevisiae or S. pombe , and ADH2 having the sequence SEQ ID Nos. 16-26 respectively, preferably the promoter CaMV, an open reading phase comprising the sequence coding for a galactosyl transferase I, comprising a targeting sequence in the endoplasmic reticulum or the Golgi apparatus and a terminator of the transcription. Preferably, the galactosyl transferase I is human, notably a sequence comprising SEQ ID NO 6, which is without the human targeting sequence. This strain is designated as “Athena”.
Advantageously, the integration of the aforementioned expression cassettes is carried out in an integration marker selected from (auxotrophy marker selected from) URA3, ADE2, LYS2, LEU2, TRP1, CAN1, ADO1, HIS5, HIS3, ARG3, MET17, LEM3, Mnn1, Mnn9, gma12. Even more advantageously, the expression cassette of α-1-2 mannosidase I is integrated into the URA3 gene, the expression cassette of N-acetyl-glucosaminyl transferase I is integrated into the ADE1 or ADE2 gene, the expression cassette of the UDP-GlcNAc transporter is integrated into the LYS2 gene, the expression cassette of α-mannosidase II is integrated in the LEU2 gene, and the expression cassette of N-acetyl-glucosaminyl transferase II is integrated into the LEM3 or TRP1 gene. The expression cassette of β-1,4-galactosyl transferase I is integrated into TRP1 or MET17. Further, a targeting sequence in the endoplasmic reticulum or the Golgi apparatus, derived from the localization sequence of the Mnt1 gene which comprises the sequence SEQ ID NO 14 and the terminator CYC1 comprising the SEQ ID NO 15, is preferably used in the constructs.
In another embodiment, the yeasts Alice and Athena, described above, of the invention, include additional modifications in order to produce glycoproteins having more than 75%, or even 80% or further 95% or 98% of a structure selected from
GlcNac2Man3GlcNAc2, Gal2GlcNac2Man3GlcNAc2, and GlcNac2Man3(Fuc)GlcNAc2, Ashley strain Gal2GlcNac2Man3(Fuc)GlcNAc2, Aurel strain
In this case, the yeasts mentioned above comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter selected from pGAP, pGAL1, PGK, TEF, adh1, nmt 1, SV40, PMA1, CaMV, pet56 of S. cerevisiae or S. pombe , and ADH2 having the sequence SEQ ID Nos. 16-26 respectively, or the promoter of the nmt1 gene, an open reading phase comprising the sequence coding for an α-1,6-fucosyl transferase FUT8, comprising a targeting sequence in the endoplasmic reticulum or the Golgi apparatus and a terminator of the transcription, in particular the terminator derived from the CYC1 gene. These strains may advantageously contain the cassette corresponding to the GDP-fucose transporter described below. This cassette may be integrated into CAN1 or HIS5.
Preferably, the α-1,6-fucosyl transferase FUT8 is human, notably a sequence comprising SEQ ID NO 7. Further, this strain should comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising the promoter SV40, and open reading phase comprising the sequence coding for a GDP-fucose transporter, notably a sequence comprising SEQ ID NO 8. This cassette may be integrated in TRP1, ARG3 or gma12.
In another embodiment, the yeasts GlcNac2Man3GlcNAc2 (Athena) and Gal2GlcNac2Man3(Fuc)GlcNAc2 (Aurel) described above of the invention, include additional modifications in order to produce glycoproteins having more than 75%, or even 80% or further 95% or 98% of a structure selected from
NANA2Gal2GlcNac2Man3GlcNAc2 Aeron strain NANA2Gal2GlcNac2Man3(Fuc)GlcNAc2 Avrel strain
In this embodiment, the yeasts mentioned above comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter among those mentioned above or the promoter of the thymidine kinase of the herpes virus comprising the sequence SEQ ID NO 9. An open reading phase comprising the sequence coding for an α-2,3-sialyl transferase (ST3GAL4 gene) and a terminator of the transcription, in particular the terminator derived from the CYC1 gene comprising the sequence SEQ ID NO 15. Preferably the sialyl transferase is human (NM — 006278), notably a sequence comprising SEQ ID NO 10.
In another embodiment, the yeasts Gal2GlcNac2Man3GlcNAc2 (Athena) and NANA2Gal2GlcNac2MAN3GLCNAc2 (Aeron) described above of the invention include additional modifications in order to produce glycoproteins having more than 75%, or even 80%, or further 95% or 98% of a structure selected from
Gal2GlcNac3Man3GlcNAc2 Azalée strain NANA2Gal2GlcNac3Man3GlcNAc2 A strain
In this embodiment, the yeasts mentioned above comprise integration by homologous recombination into an auxotrophy marker of an expression cassette comprising a promoter from those mentioned above. An open reading phase comprising the sequence coding for a β-1,4-n-acetyl-glucosaminyl transferase III and a terminator of the transcription, in particular the terminator derived from the CYC1 gene comprising the sequence SEQ ID NO 15. Preferably the GNTIII is murine, notably a sequence comprising SEQ ID NO 27.
As indicated above, the yeasts according to the invention are integrated into a cassette for expressing an exogenous glycoprotein or glycopeptide. The glycoprotein may be selected from glycoproteins for therapeutic use such as cytokines, interleukins, growth hormones, growth factors, enzymes, and monoclonal antibodies, vaccinal proteins, soluble receptors and all types of recombinant proteins. This may be a sequence coding for EPO, notably a cassette comprising SEQ ID NO 11 coding for an EPO with SEQ ID NO 12 comprising the epitope V5 and an N-terminal poly-HIS unit for purification.
The invention also relates to a pharmaceutical composition comprising a glycoprotein having homogeneous glycan structures of more than 75%, 90%, 95% or further 98% of the structure:
Man5GlcNAc2, GlcNacMan5GlcNAc2, GlcNacMan3GlcNAc2, GlcNac2Man3GlcNAc2, Gal2GlcNac2Man3GlcNAc2, NANA2Gal2GlcNac2Man3GlcNAc2, GlcNac2Man3(Fuc)GlcNAc2, Gal2GlcNac2Man3(Fuc)GlcNAc2, NANA2Gal2GlcNac2Man3GlcNAc2, Gal2GlcNac2Man3GlcNAc2, NANA2Gal2GlcNac3Man3GlcNAc2,
The invention also relates to a pharmaceutical composition comprise EPO as an active ingredient, said EPO having more than 75%, 90%, 95% or further 98% of the structure
NANA2Gal2GlcNac2Man3GlcNAc2 or NANA2Gal2GlcNac2Man3(Fuc)GlcNAc2
The invention also relates to a culture in a fermenter comprising a basic culture medium of culture media for yeasts and to a yeast described above.
In still another aspect, the invention relates to a method for producing a glycoprotein having homogeneous glycan structures with more than 75%, 90%, 95% or further 98% of the structure
Man5GlcNAc2, GlcNacMan5GlcNAc2, GlcNacMan3GlcNAc2, GlcNac2Man3GlcNAc2, Gal2GlcNac2Man3GlcNAc2, NANA2Gal2GlcNac2Man3GlcNAc2, GlcNac2Man3(Fuc)GlcNAc2, Gal2GlcNac2Man3(Fuc)GlcNAc2, NANA2Gal2GlcNac2Man3(Fuc)GlcNAc2, Gal2GlcNac3Man3GlcNAc2, NANA2Gal2GlcNac3Man3GlcNAc2
comprising the cultivation of a yeast as described above in a fermenter, and the extraction of said glycoprotein from the culture medium. This method may comprise a purification step.
Finally, the invention also relates to the use of a yeast as described above for producing in a fermenter a glycoprotein having homogeneous glycan structures with more than 75%, 90%, 95% or further 98% of the structure
Man5GlcNAc2, GlcNacMan5GlcNAc2, GlcNacMan3GlcNAc2, GlcNac2Man3GlcNAc2, Gal2GlcNac2Man3GlcNAc2, NANA2Gal2GlcNac2Man3GlcNAc2, GlcNac2Man3(Fuc)GlcNAc2, Gal2GlcNac2Man3(Fuc)GlcNAc2, NANA2Gal2GlcNac2Man3(Fuc)GlcNAc2, Gal2GlcNac3Man3GlcNAc2, NANA2Gal2GlcNac3Man3GlcNAc2
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 : PCR-based construction of an OCH1-inactivating cassette.
FIG. 2 : Construction of expression cassettes.
FIG. 3 : PCR analysis of och1:Kan R transformants.
FIG. 4 : Och1-activity assay in wild-type and PCR-selected transformants; a) S. cerevisiae , b) S. pombe.
FIG. 5 : MALDI-TOFF mass spectrometry N-glycan analysis of total proteins in Adele and Edgar strains.
FIG. 6 : Mannosidase I-activity assay in wild-type and PCR-selected transformants in presence and absence of DMJ, an inhibitor of alpha-1,2-mannosidase I activity; SC= S. cerevisiae , SP= S. pombe.
FIG. 7 : GlcNAc Transferase I-activity assay in wild-type and PCR-selected transformants; SC= S. cerevisiae , SP= S. pombe.
FIG. 8 : RT-PCR analysis of S. cerevisiae (SC) and S. pombe (SP) clones transformed with the UDP-GlcNAc transporter expression cassette.
FIG. 9 : Mannosidase II-activity assay in wild-type and PCR-selected transformants in presence and absence of swainsonine, an inhibitor of mannosidase II activity; SC= S. cerevisiae , SP= S. pombe.
FIG. 10 : RT-PCR analysis of S. cerevisiae (SC) and S. pombe (SP) clones transformed with the GDP-fucose transporter expression cassette.
FIG. 11 : MALDI-TOFF mass spectrometry N-glycan analysis of rhuEPO expressed in the Amèlie strain.
FIG. 12 : RT-PCR analysis of rhuEPO expression in pGAL-rhuEPO transformants grown with (lanes 1 and 3) galactose or with glucose (lanes 2 and 4).
FIG. 13 : Purification of rhuEPO by ion exchange chromatography (Sephadex C-50).
FIG. 14 : SDS-PAGE analysis of the ion exchange chromatography fractions.
FIG. 15 : Western blot analysis of the ion exchange chromatography fractions with an anti-EPO antibody.
DETAILED DESCRIPTION
Example 1
Creation of Mutated Strains on the Och1 Gene Coding for α-1,6-Mannosyl Transferase (Delta-Och1 Strain)
The gene for resistance to kanamycin was amplified by PCR and homologous flanking regions to the gene Och1 were added in both of these ends ( FIG. 1 ), specific regions of each strain of S. cerevisiae or S. pombe yeast. The gene Och1 is made non-functional by inserting this gene for resistance to an antibiotic, kanamycin. Integration of the gene into the genome of the yeast is accomplished by electroporation and the gene of interest is then integrated by homologous recombination. The flanking regions have about forty bases and allow integration of the kanamycin gene within the gene Och1 in the genome of the yeast.
The strains having integrated the gene for resistance to kanamycin are selected on the medium containing 50 μg/mL of kanamycin. We then checked by PCR the integration of the gene for resistance to kanamycin in the gene Och1. Genomic DNA of the clones having resisted to the presence of kanamycin in the medium, was extracted. Oligonucleotides were selected so as to check the presence of the gene for resistance to kanamycin on the one hand and that this gene was actually integrated into the Och1 gene on the other hand. Genomic DNA of wild strains was also tested; we amplified the Och1 gene of these strains. This gene has 1,100 bp. In the strains having integrated the kanamycin cassette, the observed amplification of the gene Och1 is longer (1,500 bp).
Example 2
Tests of Activities
2.1 Och1 Mannosyl Transferase Activity on Strains of Mutated Yeasts
Another validation level: for each gene integrated to the genome of the yeast strains, systematic check of the enzymatic activity was carried out, in order to constantly follow possible fluctuations in the activity levels, due for most of the time to spontaneous mutations and then requiring selection of new clones.
The activity of the Och1 enzyme may be detected by an assay in vitro. Prior studies have shown that the best acceptor for transfer of mannose by the Och1 enzyme is Man 8 GlcNAc 2 . From microsomal fractions of yeasts (100 μg of proteins) or from a lysate of total proteins (200 μg), the transfer activity of mannose in the alpha-1,6 position on a Man 8 GlcNAc 2 structure is measured. For this, the Man 8 GlcNAc 2 coupled to an amino-pyridine group (M 8 GN 2 -AP) is used as an acceptor and the GDP-mannose marked with [ 14 C]-mannose as a donor molecule of radioactive mannose. The microsomes or the proteins are incubated with the donor (radioactive GDP-mannose), the acceptor (Man 8 GlcN 2 -AP) and deoxymannojirimycin (inhibitor of mannosidase I) in a buffered medium with controlled pH. After 30 minutes of incubation at 30° C., chloroform and methanol are added to the reaction medium in order to obtain a proportion of CHCl 3 /MeOH/H 2 O of 3:2:1 (v/v/v). The upper phase corresponding to the aqueous phase, contains Man 8 GlcNAc 2 -AP, radioactive Man 9 GlcNAc 2 -AP and GDP-[ 14 C]-mannose. Once dried, the samples are taken up in 100 μL of H 2 O/1% acetic acid and passed over a Sep-Pak C18 (Waters) column, conditioned beforehand in order to separate GDP-mannose from the formed radioactive Man 9 GlcNAc 2 -AP (the AP group allows this compound to be retained on the C18 columns). By eluting with H 2 O/1% acetic acid (20 mL) and then with 20% methanol/1% acetic acid (4 mL), the different fractions may be recovered and counted with the scintillation counter.
2.2 Mannosidase Activity
Mannosidase activity is measured by incubating for 4 hours at 37° C., with 4 mM of p-nitrophenyl-α-D-mannopyranoside with 100-200 μg of proteins (from total proteins or sub-cellular fractions) in 0.1 M of PBS, pH 6.5+/−120 μM DMJ (alpha-1,2-mannosidase I inhibitor) +/−12 μM SW (specific inhibitor of mannosidase II). Absorbance is measured at 405 nm.
2.3 N-Acetylglucosaminyl Transferase Activity
GlcNAc transferase activity is measured on microsomal fractions of yeasts. 50 μg of microsomes (BCA assay) are incubated in finally 50 μL after 25 minutes at 30° C. with 0.01 μCi of donor (radioactive UDP-GlcNAc), 0.5 mM of acceptor (3-O-α-D-manno-pyranosyl-D-mannopyranoside) in a medium with 50 mM HEPES, 10 mM MnCl 2 , 0.1% TritonX-100. The reaction is stopped with 400 μL of 10 mM EDTA and the samples are then passed over Dowex AG-1X2 columns. The radioactive acceptor is then eluted from the columns with 3M formic acid and the radioactivity is measured with a scintillation counter.
Example 3
Expression Cassette for α-1-2 Mannosidase I of C. Elegans
Explanatory diagram for constructing expression cassettes: FIG. 2 .
3.1 Step 1: Obtaining the ORF
α-mannosidase I: PCR from bacterial clones having the plasmid pDONR201
(Open Biosystem)
Program:
8 minutes at 94° C. 35 cycles: 20 s at 94° C. 30 s at 65° C. 2 min at 72° C. 10 minutes at 72° C.
Amplification of a 1,644 by fragment
(SEQ ID No 1)
AAAGCAGGCatgggcctccga tcacacgaacaacttgtcgtgtgtgtcgg
agttatgtttcttctgactgtctgcatcacagcgttt
ttctttcttccgtcaggcggcgctgatctgtatttccgagaagaaaactc
cgttcacgttagagatgtgcttatcagagaggaaatt
cgtcgtaaagagcaagatgagttacggcggaaagccgaagaagccaatcc
cattccaattccaaaacctgaaattggagcat
cagatgatgcagaaggacgaagaattttcgtgaaacaaatgattaaattc
gcatgggacggatatcggaaatatgcctggggg
gagaatgaattgaggcccaacagtagatcaggacattcttcatcgatatt
tgggtatggaaagacgggtgcaacaattattgatg
ctattgatacattgtatttggttggattaaaagaagaatataaagaggcc
agagactggattgctgattttgatttcaaaacgtctgc
gaaaggagatctatcagtttttgaaacaaatatccgattcactggtggcc
tactctccgcatttgcacttaccggagacaaaatgtt
cttgaagaaagcagaagatgtggcaactattcttcttccggcttttgaaa
ctccttctggaataccaaattcattaattgatgctcaa
acaggaagatccaaaacgtatagttgggcaagcggaaaggcaattctctc
ggaatacggttcaattcaacttgaattcgattatc
tctccaatctgactggaaatccagtttttgctcaaaaagctgataaaata
agagatgttttaactgcaatggagaaaccagaagg
actttatccaatttatattactatggataatccaccaagatggggacaac
atcttttctcaatgggtgcaatggctgacagttggtat
gaatatctgctcaaacaatggattgccactggtaaaaaagatgatcgcac
gaaaagagaatacgaagaagcgatatttgcaat
ggaaaaacgaatgcttttcaaatcggaacagtcgaatctttggtatttcg
caaaaatgaacggaaatcgcatggaacattcatttg
aacatcttgcatgcttttccggtggaatggttgttcttcatgcaatgaat
gagaaaaataaaacaatatcagatcattatatgacgtt
gggaaaagaaattggtcatacatgtcatgaatcgtacgctagatccacaa
ctggaatcggcccagaatccttccaattcacatc
gagtgtagaggcaaaaacagaacgtcgtcaggattcatattatattcttc
gtcctgaagtcgttgagacatggttctacttgtgga
gggctacaaaagacgagaaatatcgacaatgggcttgggatcatgttcaa
aatttggaggagtattgtaagggcactgccgga
tactctggaatccgaaacgtctacgaatcgagcccggaacaagatgatgt
gcagcagtcattcctcttcgctgagctcttcaaat
atctgtatttaattttcagtgaagataacattcttccacttgatcaatgg
gttttcaataccgaagctcatccattcc gcattcggcatcacgacgagtt
gatt
The PCR amplification was extracted and purified from agarose gel with SBIOgene kit and was introduced into a vector TOPO2.1. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and insertion of the PCR amplification into the vector by sequencing (plasmid pGLY02.001).
3.2 Step 2: Assembling the Expression Cassette
Integration of the expression cassette of mannosidase I will be localized in the auxotrophy marker URA3 for both strains. Invalidation of this gene induces resistance to a toxic agent, 5-fluorouracil. Yeasts modified by this cassette will then become resistant to this drug but also auxotrophic for uracil.
Expression Cassette for S. Cerevisiae
Amplification of the promoter pGAP from genomic DNA of wild S. cerevisiae BS16 (forward) and BS17′ (reverse) Assembling the promoter pGAP (PCR product) and the ORF (pGLY02.001) BS16 (forward) and BS19′ (reverse) Amplification of the terminator CYC1 from the plasmid pYES 2.1 BS40b (forward) and BS41 (reverse) Assembling the ORF (plasmid pGLY02.001) and the terminator CYC1 (PCR product)
BS18 (forward) and BS41 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY02.002).
Assembling promoter-ORF (PCR product) and ORF-terminator (pGLY02.002) with regions homologous to URA3 (from the primers)
BS42 (forward)
BS43 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY02.004).
Expression Cassette for S. Pombe
Amplification of the promoter adh1 from genomic DNA of wild S. pombe
BS25 and BS26′ (reverse)
Assembling the promoter adh1 (PCR product) and the ORF (pGLY02.001)
BS25 (forward) and BS20 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector TOPO2.1. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY02.009).
Assembling the product promoter-ORF (pGLY02.009) with ORF-CYC1 (PCR product) BS25 (forward) and BS41 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY02.011).
Amplification of the cassette (pGLY02.011) with flanking regions homologous to URA3 BS76 (forward) and BS77 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing.
3.3 Step 3: Transformation of the Yeasts
Preparation of competent yeasts:
S. Cerevisiae Adèle
Procedure: Sow 500 ml of yeasts at OD=0.1 and incubate them at 30° C. until 5.5<OD<6.5.
Centrifuge the cells at 1500 g for 5 min at 4° C. and re-suspend them in 500 mL of cold sterile water.
Centrifuge the cells and re-suspend them in 250 mL of cold sterile water.
Centrifuge the cells and re-suspend them in 20 mL of 1M sorbitol. Centrifuge the cells and re-suspend them in 1 mL of 1M sorbitol. Form 80 μL aliquots and store them at −80° C.
S. Pombe Edgar
Procedure: Sow 200 mL of yeasts at OD=0.1 and incubate them at 30° C. until OD=1.5.
Centrifuge at 3,000 rpm for 5 min at 20° C. Wash the cells in cold sterile water and centrifugate, wash a second time with 1 m sorbitol. Incubate for 15 min by adding DTT in order to reach a final 25 mM (in order to increase electrocompetence). Take up again as a final suspension in cold 1M sorbitol (density 1-5.10 9 cells/mL: about 5 mL). Form 40 μL aliquots and store about 10 vials at −80° C.
Transformation of the yeasts by electroporation:
For each expression cassette, the DNA used for transforming the yeasts either stems from a digestion of the mentioned plasmid with selected restriction enzymes, or directly from the obtained PCR product, purified after complete assembling.
S. cerevisiae cassette: pGLY02.004 is digested by the restriction enzymes BamHI and SmaI.
The competent yeasts are transformed with 1 μg of DNA: incubate for 5 min in ice. Give a pulse with V=1,500 V. Immediately add 1 mL of ice-cold sterile 1M sorbitol and transfer the cells with a Pasteur pipette into an Eppendorf tube and then let them relax for at least 1 hour in the Infors device at 30° C. Spread the yeasts on a dish of selection media (YPD containing 10 mM 5-fluorouracil, 5-FU). The transformants appear within 4-6 days.
S. pombe cassette: the competent yeasts are transformed with 100 ng of DNA (PCR product): incubate for 5 min in ice. The cells and the DNA are transferred into an electroporation tank. Give a pulse at V=1,500V and immediately add 0.9 mL of cold 1M sorbitol. The cells are spread as rapidly as possible on the suitable medium (YPD containing 10 mM 5-FU). The transformants appear within 4-6 days.
Example 4
Amélie and Emma strains+expression cassette for human N-acetyl-glucosaminyl transferase I
4.1 Step 1: Obtaining ORF
PCR from a commercial plasmid Biovalley (Human ORF clone V1.1)
Program:
5 minutes at 94° C. 30 cycles: 60 s at 94° C. 60 s at 56° C. 2 min at 72° C. 5 minutes at 72° C.
Amplification of a 1,327 by fragment without the cytoplasmic portion of the enzyme. It will be replaced with the cytoplasmic portion of Mnn9 for Golgian localization of the protein.
Mnn9 cytoplasmic region: PCR from genomic DNA of wild S. cerevisiae
8 minutes at 95° C. 30 cycles: 20 s at 94° C. 30 s at 58° C. 1 min at 72° C. 10 minutes at 72° C.
Amplification of a 51 by fragment (cytoplasmic portion of mnn9).
(SEQ ID No 13) Atgtcactttctcttgtatcg taccgcctaa gaaagaacccgtggttaac
From These Two PCR Amplifications:
Obtaining a Single Fragment
(SEQ ID No 2)
Atgtcactttctcttgtatcg taccgcctaagaaagaacccgtgggttaa
cgcagggcttgtgctgtggggcgctatcctcttt
gtggcctggaatgccctgctgctcctcttcttctggacgcgcccagcacc
tggcaggccaccctcagtcagcgctctcgatgg
cgaccccgccagcctcacccgggaagtgattcgcctggcccaagacgccg
aggtggagctggagcggcagcgtgggctg
ctgcagcagatcggggatgccctgtcgagccagcgggggagggtgcccac
cgcggcccctcccgcccagccgcgtgtgc
ctgtgacccccgcgccggcggtgattcccatcctggtcatcgcctgtgac
cgcagcactgttcggcgctgcctggacaagctg
ctgcattatcggccctcggctgagctcttccccatcatcgttagccagga
ctgcgggcacgaggagacggcccaggccatcg
cctcctacggcagcgcggtcacgcacatccggcagcccgacctgagcagc
attgcggtgccgccggaccaccgcaagttc
cagggctactacaagatcgcgcgccactaccgctgggcgctgggccaggt
cttccggcagtttcgcttccccgcggccgtgg
tggtggaggatgacctggaggtggccccggacttcttcgagtactttcgg
gccacctatccgctgctgaaggccgacccctcc
ctgtggtgcgtctcggcctggaatgacaacggcaaggagcagatggtgga
cgccagcaggcctgagctgctctaccgcacc
gactttttccctggcctgggctggctgctgttggccgagctctgggctga
gctggagcccaagtggccaaaggccttctggga
cgactggatgcggcggccggagcagcggcaggggcgggcctgcatacgcc
ctgagatctcaagaacgatgacctttggcc
gcaagggtgtgagccacgggcagttctttgaccagcacctcaagtttatc
aagctgaaccagcagtttgtgcacttcacccagc
tggacctgtcttacctgcagcgggaggcctatgaccgagatttcctcgcc
cgcgtctacggtgctccccagctgcaggtggag
aaagtgaggaccaatgaccggaaggagctgggggaggtgcgggtgcagta
tacgggcagggacagcttcaaggctttcgc
caaggctctgggtgtcatggatgaccttaagtcgggggttccgagagctg
gctaccggggtattgtcaccttccagttccggg
gccgccgtgtccacctggcgcccccactgacgtgggagggctatgatcct
agctggaa ttagcacctgcctgtccttc
The amplification product of the assembling PCR was purified from agarose gel with the QIAGEN kit and was introduced into a vector TOPO2.1. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY03.001).
4.2 Step2: Assembling the Expression Cassette
Expression Cassette for S. Cerevisiae
The integration of the expression cassette of the GlcNAc transferase I for the yeast S. cerevisiae will be localized in the auxotrophy marker ADE2. Invalidation of this gene induces a change in the color of the yeasts which become red and also auxotrophy for adenine.
of the promoter adh 1 from genomic DNA of S. cerevisiae
BS29 (forward) and BS30 (reverse)
Assembling the promoter adh 1 (PCR product) and the ORF (pGLY03.001):
BS29 (forward) and BS59
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification in the vector by sequencing (pGLY03.002).
Assembling of the ORF (pGLY03.001) with the terminator CYC1 (PCR product):
CA005 (forward)
BS41 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY03.011).
Assembling the promoter-ORF (pGLY03.002) and the ORF-terminator (PCR product) with the extensions homologous to ADE2:
BS67 (forward) and BS68 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY03.010).
Expression Cassette for S. Pombe
The integration of the expression cassette of the GlcNAc transferase I for the yeast S. pombe will be localized in the auxotrophy marker ADE1. Invalidation of this gene induces a change in the color of the yeasts which become red and also auxotrophy for adenine.
Amplification of the promoter hCMV from the plasmid pCDNA 3.1
BS62 (forward) and BS58 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY03.004).
Assembling hCMV-ORF (pGLY03.004) with the terminator CYC1 (PCR product) BS62 (forward) and BS41 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY03.005).
Assembling the expression cassette (pGLY03.005) with the extensions homologous to ADD:
BS69 (forward) and BS70 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY03.007).
4.3 Step 3: Transformation of the Yeasts
Preparation of Competent Yeasts:
The Amélie and Emma strains were prepared as indicated above in order to make them competent.
Electroporation of the Yeasts S. Cerevisiae and S. Pombe
Procedure:
20 μg of plasmids containing the expression cassette for S. cerevisiae and S. pombe were digested by the restriction enzyme EcoRI. The linearized cassette was introduced in the yeasts Amélie and Emma by electroporation. The yeasts are selected on an YNB medium containing the required amino acids.
Example 5
Agathe and Egée strains+expression cassette for the UDP-GlcNAc transporter
5.1 Step 1: Obtaining the ORF
Program:
3 minutes at 94° C. 30 cycles: 20 s at 94° C. 30 s at 58° C. 2 min at 72° C. 10 minutes at 72° C.
Amplification of a 916 by Fragment
(SEQ ID No 3)
atgttcgccaacctaaaatacg tttccctgggaattttggtctttcagac
taccagtttggttctaacaatgcgttattccagaact
ttaaaagaagaaggacctcgttatctatcttctacagcagtggttgttgc
tgaacttttgaagataatggcctgcattttattggtcta
caaagacagcaaatgtagtctaagagcactgaatcgagtactacatgatg
aaattcttaataaacctatggaaacacttaaactt
gctattccatcagggatctatactcttcagaataatttactgtatgtggc
actatcaaatctagatgcagctacttatcaggtcacgt
atcagttgaaaattcttacaacagcattattttctgtgtctatgcttagt
aaaaaattgggtgtataccagtggctgtccctagtaattt
tgatgacaggagttgcttttgtacagtggccctcagattctcagcttgat
tctaaggaactttcagctggttctcaatttgtaggact
catggcagttctcacagcatgtttttcaagtggctttgctggggtttact
ttgagaaaatcttaaaagaaacaaaacaatcagtgtg
gataagaaatattcagcttggtttctttggaagtatatttggattaatgg
gtgtatacatttatgatggagaactggtatcaaagaatg
gattttttcagggatataaccgactgacctggatagtagttgttcttcag
gcacttggaggccttgtaatagctgctgttattaagtat
gcagataatattttaaaaggatttgcaacctctttatcgataatattatc
aacattgatctcctatttttggcttcaagattttgtgccaa
ccagtgtcttttt ccttggagccatccttgtaa
The PCR amplification was extracted and purified from agarose gel with the QIAGEN kit and was introduced into a vector TOPO2.1. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY04.001).
5.2 Step 2: Assembling the Expression Cassette
Cassette for S. Cerevisiae and for S. Pombe
The integration of the expression cassette of the UDP-GlcNAc transporter will be localized in the auxotrophy marker LYS2 for both strains S. cerevisiae and S. pombe . Invalidation of this gene induces resistance to a toxic agent, alpha-aminoadipic acid. The yeasts modified by this cassette will therefore become resistant to this drug but also auxotrophic for lysine.
Amplification of the promoter PGK from the plasmid pFL61
BS95 (forward) and BS96 (reverse)
Assembling the ORF (pGLY04.001) with the terminator CYC1 (PCR product)
CA017 (forward) and BS41 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector TOPO2.1. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY04.002).
Assembling the promoter PGK (PCR product) with the ORF-terminator CYC1 fragment (pGLY04.002):
BS95 (forward) and BS41 (reverse)
Assembling the expression cassette with the extensions homologous to LYS2
S. cerevisiae:
BS97 (forward) and BS98 (reverse)
S. Pombe
BS99 (forward)
BS100 (reverse)
The PCR amplifications were extracted and purified from agarose gel with the Qiagen kit and were introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY04.006) for the S. cerevisiae cassette and pGLy04.005 for the S. pombe cassette).
5.3 Step 3: Modification of the Yeasts
Preparation of Competent Yeasts:
The Agathe and Egée strains were prepared as indicated above in order to make them competent
Electroporation of the Yeasts:
20 μg of the plasmids containing the expression cassettes for S. cerevisiae, S. pombe were digested by the restriction enzyme EcoRI. The linearized cassette was introduced into the yeasts Agathe and Egée by electroporation. The yeasts are selected on an YNB medium containing the required amino acids and alpha-aminoadipic acid.
Example 6
Arielle and Erika Strains+Expression Cassette for α-mannosidase II
6.1 Step 1: Obtaining the oRF
PCR from cDNA of mouse liver
Program:
3 minutes at 94° C. 35 cycles: 20 s at 94° C. 30 s at 58° C. 4 min at 72° C. 10 minutes at 72° C.
Amplification of a 3,453 by fragment
(SEQ ID No 4)
atgaagttaagtcgccagttcacc gtgtttggcagcgcgatcttctgcgt
cgtaatcttctcactctacctgatgctggacagg
ggtcacttggactaccctcggggcccgcgccaggagggctcctttccgca
gggccagctttcaatattgcaagaaaagattga
ccatttggagcgtttgctcgctgagaacaacgagatcatctcaaatatca
gagactcagtcatcaacctgagcgagtctgtgga
ggacggcccgcgggggtcaccaggcaacgccagccaaggctccatccacc
tccactcgccacagttggccctgcaggctg
accccagagactgtttgtttgcttcacagagtgggagtcagccccgggat
gtgcagatgttggatgtttacgatctgattccttttg
ataatccagatggtggagtttggaagcaaggatttgacattaagtatgaa
gcggatgagtgggaccatgagcccctgcaagtg
tttgtggtgcctcactcccataatgacccaggttggttgaagactttcaa
tgactactttagagacaagactcagtatatttttaataa
catggtcctaaagctgaaagaagactcaagcaggaagtttatgtggtctg
agatctcttaccttgcaaaatggtgggatattatag
atattccgaagaaggaagctgttaaaagtttactacagaatggtcagctg
gaaattgtgaccggtggctgggttatgcctgatga
agccactccacattattttgccttaattgaccaactaattgaagggcacc
aatggctggaaaaaaatctaggagtgaaacctcga
tcgggctgggccatagatccctttggtcattcacccacaatggcttatct
tctaaagcgtgctggattttcacacatgctcatccag
agagtccattatgcaatcaaaaaacacttctctttgcataaaacgctgga
gtttttctggagacagaattgggatcttggatctgct
acagacattttgtgccatatgatgcccttctacagctacgacatccctca
cacctgtgggcctgatcctaaaatatgctgccagttt
gattttaaacggcttcctggaggcagatatggttgtccctggggagttcc
cccagaagcaatatctcctggaaatgtccaaagc
agggctcagatgctattggatcagtaccggaaaaagtcaaaacttttccg
cactaaagttctgctggctccactgggagacgac
tttcggttcagtgaatacacagagtgggatctgcagtgcaggaactacga
gcaactgttcagttacatgaactcgcagcctcatc
tgaaagtgaagatccagtttggaaccttgtcagattatttcgacgcattg
gagaaagcggtggcagccgagaagaagagtagc
cagtctgtgttccctgccctgagtggagacttcttcacgtacgctgacag
agacgaccattactggagtggctacttcacgtcca
gacctttctacaaacgaatggacagaataatggaatctcgtataagggct
gctgaaattctttaccagttggccttgaaacaagct
cagaaatacaagataaataaatttctttcatcacctcattacacaacact
gacagaagccagaaggaacttaggactatttcagc
atcatgatgccatcacaggaaccgcgaaagactgggtggttgtggactat
ggtaccagactctttcagtcattaaattctttggag
aagataattggagattctgcatttcttctcattttaaaggacaaaaagct
gtaccagtcagatccttccaaagccttcttagagatg
gatacgaagcaaagttcacaagattctctgccccaaaaaattataataca
actgagcgcacaggagccaaggtaccttgtggtc
tacaatccctttgaacaagaacggcattcagtggtgtccatccgggtaaa
ctccgccacagggaaagtgctgtctgattcggga
aaaccggtggaggttcaagtcagtgcagtttggaacgacatgaggacaat
ttcacaagcagcctatgaggtttcttttctagctc
atataccaccactgggactgaaagtgtttaagatcttagagtcacaaagt
tcaagctcacacttggctgattatgtcctatataata
atgatggactagcagaaaatggaatattccacgtgaagaacatggtggat
gctggagatgccataacaatagagaatcccttc
ctggcgatttggtttgaccgatctgggctgatggagaaagtgagaaggaa
agaagacagtagacagcatgaactgaaggtcc
agttcctgtggtacggaaccaccaacaaaagggacaagagcggtgcctac
ctcttcctgcctgacgggcagggccagccat
atgtttccctaagaccgccctttgtcagagtgacacgtggaaggatctac
tcagatgtgacctgtttcctcgaacacgttactcac
aaagtccgcctgtacaacattcagggaatagaaggtcagtccatggaagt
ttctaatattgtaaacatcaggaatgtgcataacc
gtgagattgtaatgagaatttcatctaaaataaacaaccaaaatagatat
tatactgacctaaatggatatcagattcagcctagaa
ggaccatgagcaaattgcctcttcaagccaacgtttacccgatgtgcaca
atggcgtatatccaggatgctgagcaccggctca
cgctgctctctgctcagtctctaggtgcttccagcatggcttctggtcag
attgaagtcttcatggatcgaaggctcatgcaggat
gataaccgtggccttgggcaaggcgtccatgacaataagattacagctaa
tttgtttcgaatcctcctcgagaagagaagcgct
gtgaacatggaagaagaaaagaagagccctgtcagctacccttccctcct
cagccacatgacttcgtccttcctcaaccatccc
tttctccccatggtactaagtggccagctcccctcccctgcctttgagct
gctgagtgaatttcctctgctgcagtcctctctacctt
gtgatatccatctggtcaacctgcggacaatacaatcaaagatgggcaaa
ggctattcggatgaggcagccttgatcctccaca
ggaaagggtttgattgccagttctccagcagaggcatcgggctaccctgt
tccactactcagggaaagatgtcagttctgaaac
ttttcaacaagtttgctgtggagagtctcgtcccttcctctctgtccttg
atgcactcccctccagatgcccagaacatgagtgaag tcagcctgagcc
ccatggagatcagcacgttccgtatc cgcttgcgttggacctga
The amplification of this ORF was obtained by nested PCR (3,453 bp) on cDNA of mouse liver and then purified by the phenol/chloroform method. The PCR product was introduced into a vector TOPO-XL. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY05.001).
6.2 Step 2: Assembling the Expression Cassette S. Cerevisiae and S. Pombe Cassette
The integration of the expression cassette of mannosidase II will be localized in the auxotrophy marker LEU2 for both strains. Invalidation of this gene induces a resistance to a toxic agent, trifluoroleucine. The yeasts modified by this cassette will therefore become resistant to this drug but also auxotrophic for leucine.
Amplification of the promoter TEF from genomic DNA of S. cerevisiae
BS83 (forward) and BS84 (reverse)
Assembling the promoter TEF (PCR product) with the ORF (PCR product) and the terminator (PCR product)
For S. cerevisiae marker LEU2
BS111 (forward) and BS112 (reverse)
For S. pombe marker LEU2
BS113 (forward) and BS114 (reverse)
The PCR amplifications were extracted and purified from agarose gel with the Qiagen kit and were introduced in a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLy05.008 for the S. cerevisiae cassette, pGly05.009 for the S. pombe cassette).
6.3 Step 3: Modification of the Yeasts
Preparation of competent yeasts:
The Arielle and Erika strains were prepared as indicated above in order to make them competent
Electroporation of the Yeasts
Procedure: 20 μg of the plasmids containing the expression cassette for S. cerevisiae and S. pombe were digested by the restriction enzyme EcoRI. The linearized cassette was introduced into the yeasts Arielle and Erika by electroporation. The yeasts are selected on an YNB medium containing the required amino acids as well as tri-fluoroleucine (TFL) of S. cerevisiae and S. pombe
Example 7
Anaïs and Enrique Strains+Expression Cassette of N-acety-glucosaminyl transferase II
6.1 Step 1: Obtaining the OR
PCR from complementary DNA of human fibroblasts—Use of Taq polymerase Isis™ (Q-Biogene)
Program:
3 minutes at 94° C. 30 cycles: 30 s at 94° C. 30 s at 58° C. 1.30 min at 68° C.
Amplification of a 1,344 by fragment
(SEQ ID No 5)
atgaggttccgcat ctacaaacggaaggtgctaatcctgacgctcgtggt
ggccgcctgcggcttcgtcctctggagcagca
atgggcgacaaaggaagaacgaggccctcgccccaccgttgctggacgcc
gaacccgcgcggggtgccggcggccgcg
gtggggaccacccctctgtggctgtgggcatccgcagggtctccaacgtg
tcggcggcttccctggtcccggcggtccccca
gcccgaggcggacaacctgacgctgcggtaccggtccctggtgtaccagc
tgaactttgatcagaccctgaggaatgtagat
aaggctggcacctgggccccccgggagctggtgctggtggtccaggtgca
taaccggcccgaatacctcagactgctgctg
gactcacttcgaaaagcccagggaattgacaacgtcctcgtcatctttag
ccatgacttctggtcgaccgagatcaatcagctga
tcgccggggtgaatttctgtccggttctgcaggtgttctttcctttcagc
attcagttgtaccctaacgagtttccaggtagtgaccc
tagagattgtcccagagacctgccgaagaatgccgctttgaaattggggt
gcatcaatgctgagtatcccgactccttcggcca
ttatagagaggccaaattctcccagaccaaacatcactggtggtggaagc
tgcattttgtgtgggaaagagtgaaaattcttcga
gattatgctggccttatacttttcctagaagaggatcactacttagcccc
agacttttaccatgtcttcaaaaagatgtggaaactg
aagcagcaagagtgccctgaatgtgatgttctctccctggggacctatag
tgccagtcgcagtttctatggcatggctgacaag
gtagatgtgaaaacttggaaatccacagagcacaatatgggtctagcctt
gacccggaatgcctatcagaagctgatcgagtg
cacagacactttctgtacttatgatgattataactgggactggactcttc
aatacttgactgtatcttgtcttccaaaattctggaaag
tgctggttcctcaaattcctaggatctttcatgctggagactgtggtatg
catcacaagaaaacctgtagaccatccactcagagt
gcccaaattgagtcactcttaaataataacaaacaatacatgtttccaga
aactctaactatcagtgaaaagtttactgtggtagcc
atttccccacctagaaaaaatggagggtggggagatattagggaccatga
actctgtaaa agttatagaagactgcagtga
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector pTarget (Promega). Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY08.002).
Cytoplasmic region of mmn9: PCR from genomic DNA of wild S. cerevisiae
8 minutes at 94° C. 30 cycles: 20 s at 94° C. 30 s at 65° C. 1 min at 72° C. 10 minutes at 72° C.
Amplification of a 51 by fragment (cytoplasmic portion of mmn9)+homology to
GNTII
Atgtcactttctcttgtatcg taccgcctaag aaagaacccgtgggttaacaggttccgcatctac
Assembling Mnn9 (PCR product) and the ORF (pGLY08.002) with Taq Platinium
CA005 (forward) and CD005 (reverse)
Program:
2 minutes at 95° C.
30 cycles:
45 s at 95° C.
45 s at 54° C.
2 min at 72° C.
10 minutes at 72° C.
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector pTarget (Promega). Competent bacteria (JM109), Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY08.007).
7.2 Step 2: Assembling Expression Cassette for S. Cerevisiae and S. Pombe Strains
The integration of the expression cassette of the GlcNAc-transferase II will be inserted into the Lem3 marker for S. cerevisiae and TRP1 marker for S. pombe . Invalidation of the gene Lem3 induces a resistance to a toxic agent, miltefosine. The yeasts modified by this cassette will therefore become resistant to this drug. Invalidation of the gene TRP1 induces a resistance to a toxic agent, 5-fluoro-anthranilic acid. The yeasts modified by this cassette will therefore become resistant to this drug but also auxotrophic for tryptophan.
Amplification of the promoter PMA1
CD001 (forward) aagcttcctgaaacggag CD008 (reverse) acgatacaagagaaagtgacatattgatattgtttgataattaaat
PCR from genomic DNA of S. cerevisiae
Program:
2 minutes at 95° C. 30 cycles: 45 s at 95° C. 45 s at 54° C. 2 min at 72° C. 5 minutes at 72° C.
Assembling the promoter PMA1 (PCR product) with Mnn9-homology ORF (pGLY08.007) with Taq Expand (Roche)
CD007
cgtttgtagatgcggaacctgttaacccacgggttcttt
CD001
aagcttcctgaaacggag
2 minutes at 94° C.
30 cycles:
45 s at 94° C.
45 s at 55° C.
1.15 min at 68° C.
5 minutes at 68° C.
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector TOPO2.1 (Invitrogen). Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY08.005).
Assembling Mnn9-ORF (pGLY08.007) with the terminator CYC1 (PCR product) with Taq polymerase Phusion™ (Ozyme)
Program
2 minutes at 98° C. 3 cycles: 10 s at 98° C. 30 s at 52° C. 40 s at 72° C.
addition of the primers and then
30 cycles
10 s at 98° C.
30 s at 61° C.
40 s at 72° C.
5 min at 72° C.
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector pTarget (Promega). Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY08.04).
Assembling the promoter PMA1-Mnn9 (pGLY08.009) with Mnn9-ORF-terminator CYC1 (PCR product) with the ends homologous to the marker Lem3 for S. cerevisiae with Taq polymerase Phusion™ (Ozyme)
CB053: Atggtaaatttcgatttgggccaagttggtgaagtattccaagcttcctgaaacggag (forward) CB070: Ttctaccgccgaagagccaaaacgttaataatatcaatggcagcttgcaaattaaagc (reverse)
Program
2 minutes at 98° C. 3 cycles: 10 s at 98° C. 30 s at 52° C. 4 min at 72° C.
addition of the primers and then
30 cycles
10 s at 98° C.
30 s at 61° C.
1 min at 72° C.
5 min at 72° C.
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector pTarget (Promega). Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY08).
Assembling the ends homologous to the marker TRP1 for S. pombe from pGLY08.012
CD009 (forward)
taaagttgattccgctggtgaaatcatacatggaaaagtttaagcttcctgaaacggag
CD010 (reverse)
atgtgaaatttccttggccacggacaagtccacttttcgtttggcagcttgcaaattaaagc
7.3 Step 3: Modification of the Yeasts
Preparation of competent yeasts:
The Anaïs and Enrique strains were prepared as indicated above in order to make them competent.
Electroporation of the yeasts Procedure: 20 μg of the plasmids containing the expression cassette for S. cerevisiae and S. pombe were digested by the restriction enzyme EcoRI. The linearized cassette was introduced into the yeasts Anaïs and Enrique by electroporation. The yeasts are then spread over a gelosed YPD medium containing the required selection drug.
Example 8
Alice and Elga Strains+Expression Cassette of Galactosyl Transferase I
8.1 Step 1: Obtaining the ORF Without the Human Localization Sequence
PCR from cDNA of human lymphoblasts
CD025 (forward) CD026 (reverse)
2 minutes at 94° C. 30 cycles: 45 s at 94° C. 45 s at 58° C. 1.15 min at 72° C. 5 minutes at 72° C.
Amplification of a 1,047 by fragment
(SEQ ID No 6)
ccccaactggtcggagt ctccacaccgctgcagggcggctcgaacagtgc
cgccgccatcgggcagtcctccggggagc
tccggaccggaggggcccggccgccgcctcctctaggcgcctcctcccag
ccgcgcccgggtggcgactccagcccagt
cgtggattctggccctggccccgctagcaacttgacctcggtcccagtgc
cccacaccaccgcactgtcgctgcccgcctgc
cctgaggagtccccgctgcttgtgggccccatgctgattgagtttaacat
gcctgtggacctggagctcgtggcaaagcagaa
cccaaatgtgaagatgggcggccgctatgcccccagggactgcgtctctc
ctcacaaggtggccatcatcattccattccgca
accggcaggagcacctcaagtactggctatattatttgcacccagtcctg
cagcgccagcagctggactatggcatctatgttat
caaccaggcgggagacactatattcaatcgtgctaagctcctcaatgttg
gctttcaagaagccttgaaggactatgactacacc
tgctttgtgtttagtgacgtggacctcattccaatgaatgaccataatgc
gtacaggtgtttttcacagccacggcacatttccgttg
caatggataagtttggattcagcctaccttatgttcagtattttggaggt
gtctctgctctaagtaaacaacagtttctaaccatcaat
ggatttcctaataattattggggctggggaggagaagatgatgacatttt
taacagattagtttttagaggcatgtctatatctcgcc
caaatgctgtggtcgggaggtgtcgcatgatccgccactcaagagacaag
aaaaatgaacccaatcctcagaggtttgaccg
aattgcacacacaaaggagacaatgctctctgatggtttgaactcactca
cctaccaggtgctggatgtacagagatacccattg tatacccaaatcac
agtgga catcgggacaccgacctag .
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector pTarget (Promega). Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY11.003).
Mnt1 localization: PCR from gDNA of S. cerevisiae
3 minutes at 94° C. 30 cycles: 20 s at 94° C. 30 s at 58° C. 45 s at 72° C. 10 minutes at 72° C.
Amplification of a 246 by fragment—SEQ ID NO 14
atggccctctttctcagtaa gagactgttgagatttaccgtcattgcagg
tgcggttattgttctcctcctaacattgaattccaac
agtagaactcagcaatatattccgagttccatctccgctgcatttgattt
tacctcaggatctatatcccctgaacaacaagtcatct
ctgaggaaaatgatgctaaaaaattagagcaaagtgctctgaattcagag
gcaag cgaagactccgaagcc
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector pTarget (Promega). Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing.
8.2: Step 2: Assembling Expression Cassettes for the S. Cerevisiae and S. Pombe Strains
The integration of the expression cassettes of Galactosyl transferase I will be localized in the marker TRP1 for S. cerevisiae Alice. Invalidation of this gene induces resistance to a toxic agent, fluoroanthranilic acid. The yeasts modified by this cassette will therefore become resistant to this drug. The integration of the expression cassette of Galactosyl transferase I will be localized in the marker Met17 for S. cerevisiae Ashley.
Amplification of the promoter CaMV from the plasmid pMDC:
CD035 (forward)
CD037 (reverse)
Program
2 minutes at 94° C.
30 cycles:
45 s at 94° C.
45 s at 65° C.
2 min 30 s at 72° C.
5 minutes at 72° C.
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY11.001).
Assembling the promoter CaMV (pGLY11.001) with the Mnt1 localization sequence (PCR product):
CD035 (forward) and CD028 (reverse)
Program:
2 minutes at 94° C. 30 cycles: 45 s at 94° C. 45 s at 59° C. 1 min 15 s at 72° C. 3 minutes at 72° C.
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY11.002).
Assembling the promoter CaMV-Mnt1 localization (pGLY011.002) with the ORF (PCR product).
CD035 (forward)
CD029 (reverse)
Program:
2 minutes at 94° C.
30 cycles:
45 s at 94° C.
45 s at 56° C.
2 min 30 s at 72° C.
3 minutes at 72° C.
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector pTarget (Promega). Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY011.004).
Assembling the promoter CaMV-localization Mnt1-ORF (pGLY011.004) with the terminator CYC1 (PCR product) with Taq Expand (Roche)
CD035 (forward) BS41 (reverse)
Program:
3 minutes at 95° C.
30 cycles:
30 s at 95° C.
30 s at 57° C.
2 min 30 s at 68° C.
10 minutes at 68° C.
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector pTarget (Promega). Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY011.005).
Assembling the integration cassette for S. cerevisiae with Taq Expand (Roche)
CD063 (forward) agatgccagaaacaaagcttgttgcaggtggtgctgctcatgcctgcaggtcaacatggt CD064 (reverse) gtgtcgacgatcttagaagagtccaaaggtttgactggatgcagcttgcaaattaaagcc
Program
3 minutes at 95° C.
30 cycles:
30 s at 95° C.
30 s at 57° C.
2 min 30 s at 68° C.
10 minutes at 68° C.
The PCR amplification was purified by the phenol/chloroform method and introduced into the vector TOPO 2.1 (Invitrogen). Competent bacteria (TOP10 Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY011.008).
For S. pombe , integration into the sequence PET6
Use of Taq Expand (Roche)
CD038 (forward) and CD039 (reverse)
The PCR products were introduced into a vector TOPO-XL. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of PCR amplification into the vector by sequencing (pGLY11.006 for S. pombe and pGLY11.007 for S. cerevisiae ).
8.3 Step 3: Modification of the Yeasts
Preparation of competent yeasts:
The Alice and Elga strains were prepared as indicated above in order to make them competent.
Electroporation of the yeasts Procedure: 20 μg of the plasmids containing the expression cassettes for S. cerevisiae and S. pombe were digested by restriction enzymes KpnI and XhoI. The linearized cassette was introduced into the yeasts Alice and Elga by electroporation. The yeasts were then spread on a gelosed YPD medium containing the required selection.
Example 9
Strains Anaïs and Enrique+Expression Cassettes for Fucosylation (α1,6-Fucosyl Transferase FUT8 and GDP-Fucose Transporter)
9.1 Expression Cassette of FUT8
9.1.1 Step 1: Obtaining the ORF
PCR from cDNA of human pancreas and lungs
Program:
3 minutes at 94° C. 35 cycles: 20 s at 94° C. 30 s at 58° C. 2 min at 72° C. 10 minutes at 72° C.
Amplification of a 1,801 by fragment
(SEQ ID No 7)
caggactccagggaagtgag ttgaaaatctgaaaatgcggccatggactg
gttcctggcgttggattatgctcattctttttgcc
tgggggaccttgctgttttatataggtggtcacttggtacgagataatga
ccatcctgatcactctagccgagaactgtccaagat
tctggcaaagcttgaacgcttaaaacagcagaatgaagacttgaggcgaa
tggccgaatctctccggataccagaaggccct
attgatcaggggccagctataggaagagtacgcgttttagaagagcagct
tgttaaggccaaagaacagattgaaaattacaa
gaaacagaccagaaatggtctggggaaggatcatgaaatcctgaggagga
ggattgaaaatggagctaaagagctctggttt
ttcctacagagtgaattgaagaaattaaagaacttagaaggaaatgaact
ccaaagacatgcagatgaatttcttttggatttagg
acatcatgaaaggtctataatgacggatctatactacctcagtcagacag
atggagcaggtgattggcgggaaaaagaggcc
aaagatctgacagaactggttcagcggagaataacatatcttcagaatcc
caaggactgcagcaaagccaaaaagctggtgt
gtaatatcaacaaaggctgtggctatggctgtcagctccatcatgtggtc
tactgcttcatgattgcatatggcacccagcgaac
actcatcttggaatctcagaattggcgctatgctactggtggatgggaga
ctgtatttaggcctgtaagtgagacatgcacagac
agatctggcatctccactggacactggtcaggtgaagtgaaggacaaaaa
tgttcaagtggtcgagcttcccattgtagacagt
cttcatccccgtcctccatatttacccttggctgtaccagaagacctcgc
agatcgacttgtacgagtgcatggtgaccctgcagt
gtggtgggtgtctcagtttgtcaaatacttgatccgcccacagccttggc
tagaaaaagaaatagaagaagccaccaagaagc
ttggcttcaaacatccagttattggagtccatgtcagacgcacagacaaa
gtgggaacagaagctgccttccatcccattgaag
agtacatggtgcatgttgaagaacattttcagcttcttgcacgcagaatg
caagtggacaaaaaaagagtgtatttggccacaga
tgacccttctttattaaaggaggcaaaaacaaagtaccccaattatgaat
ttattagtgataactctatttcctggtcagctggactg
cacaatcgatacacagaaaattcacttcgtggagtgatcctggatataca
ttttctctctcaggcagacttcctagtgtgtactttttc
atcccaggtctgtcgagttgcttatgaaattatgcaaacactacatcctg
atgcctctgcaaacttccattctttagatgacatctact
attttgggggccagaatgcccacaatcaaattgccatttatgctcaccaa
ccccgaactgcagatgaaattcccatggaacctg
gagatatcattggtgtggctggaaatcattgggatggctattctaaaggt
gtcaacaggaaattgggaaggacgggcctatatc
cctcctacaaagttcgagagaagatagaaacggtcaagtaccccacatat
cctgaggctgagaaataaagctcagatggaag agat aaacgaccaaact
cagttcga
The PCR amplification (1,801 by from cDNA of human lungs and pancreas) was extracted and purified from agarose gel with the QBIOgene kit and was introduced into a vector TOPO2.1. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing.
9.1.2 Step2: Assembling the Expression Cassette for S. Cerevisiae
Amplification of the promoter mnt1 from genomic DNA of S. pombe
BS86 (forward) and BS84 (reverse)
Assembling the promoter mnt1 (PCR product) with the ORF (pGLY06.001)
BS86 (forward) and BS88 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY06.003).
Assembling the ORF (pGLY06.001) with the terminator CYC1 (PCR product)
CA011 (forward) and BS41 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY06.002).
Assembling nmt1-ORF (pGLY06.003) with ORF-terminator CYC1 (PCR product)
BS86 (forward) and BS41 (reverse)
Assembling the ends for integration into auxotrophy markers of yeasts:
9.1.2.1 S. Cerevisiae
The integration of the expression cassette of FUT8 was localized in the marker CAN1 for S. cerevisiae strain. Invalidation of the gene CAN1 induces auxotrophy for canavanine.
BS147 (forward) and BS148 (reverse)
The PCR amplifications were extracted and purified from agarose gel with the Qiagen kit and were introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY06.005).
9.1.2.2 S. Pombe
The expression cassette for fucosyl transferase 8 was produced in tandem with a cassette for resistance to an antibiotic, phleomycin. This double cassette is inserted in a simple auxotrophy marker HIS5. Insertion of this cassette into this locus will induce resistance to phleomycin as well as auxotrophy for histidine.
The expression cassette of FUT8 obtained previously is assembled with an expression cassette of phleomycin comprising the promoter of SV40, the ORF of the resistance to phleomycin as well as the terminator TEF. These tandem cassettes are inserted into the marker HIS5.
9.1.3 Step 3: Modification of the Yeasts
Preparation of competent yeasts:
The Anaïs and Enrique strains were prepared as indicated above in order to make them competent.
Electroporation of the yeasts Procedure: 20 μg of plasmids containing the expression cassette for S. cerevisiae and S. pombe were digested by the restriction enzyme EcoRI. The linearized cassette was introduced into the yeasts Anaïs and Enrique by electroporation. The yeasts are spread with a limiting dilution on a gelosed YPD medium, the deleted markers do not impart resistance to a drug. Once the clones have been released, replicates on a minimum medium are established in order to select the clones which can no longer grow without the required amino acid.
9.2 Expression Cassette of the GDP-Fucose Transporter
9.2.1 Obtaining the ORF
PCR from cDNA of human lungs
Program:
3 minutes at 94° C. 35 cycles: 20 s at 94° C. 30 s at 58° C. 2 min at 72° C. 10 minutes at 72° C.
Amplification of a 1,136 by fragment
(SEQ ID No 8)
tgacccagctcctctgctac catgaatagggcccctctgaagcggtccag
gatcctgcacatggcgctgaccggggcctca
gacccctctgcagaggcagaggccaacggggagaagccctttctgctgcg
ggcattgcagatcgcgctggtggtctccctct
actgggtcacctccatctccatggtgttccttaataagtacctgctggac
agcccctccctgcggctggacacccccatcttcgt
caccttctaccagtgcctggtgaccacgctgctgtgcaaaggcctcagcg
ctctggccgcctgctgccctggtgccgtggact
tccccagcttgcgcctggacctcagggtggcccgcagcgtcctgcccctg
tcggtggtcttcatcggcatgatcaccttcaata
acctctgcctcaagtacgtcggtgtggccttctacaatgtgggccgctca
ctcaccaccgtcttcaacgtgctgctctcctacctg
ctgctcaagcagaccacctccttctatgccctgctcacctgcggtatcat
catcgggggcttctggcttggtgtggaccaggag
ggggcagaaggcaccctgtcgtggctgggcaccgtcttcggcgtgctggc
tagcctctgtgtctcgctcaacgccatctacac
cacgaaggtgctcccggcggtggacggcagcatctggcgcctgactttct
acaacaacgtcaacgcctgcatcctcttcctgc
ccctgctcctgctgctcggggagcttcaggccctgcgtgactttgcccag
ctgggcagtgcccacttctgggggatgatgacg
ctgggcggcctgtttggctttgccatcggctacgtgacaggactgcagat
caagttcaccagtccgctgacccacaatgtgtcg
ggcacggccaaggcctgtgcccagacagtgctggccgtgctctactacga
ggagaccaagagcttcctctggtggacgagc
aacatgatggtgctgggcggctcctccgcctacacctgggtcaggggctg
ggagatgaagaagactccggaggagcccag ccccaaagacagcgagaag
ag cgccatgggggtgtgagc accacaggcaccctggat
The PCR amplification was extracted and purified from agarose gel with the QIAGEN kit and was introduced into a vector TOPO2.1. Competent bacteria (TOP10, Invitrogen) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY07.001).
9.2.2 Step 2: Assembling the Expression Cassette for S. Cerevisiae and S. Pombe
Amplification of the promoter SV40 from pTarget:
BS109 (forward) and BS110 (reverse)
Assembling the ORF (pGLY07.001) with the terminator CYC1 (PCR product) CA013 (forward) and BS41 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY07.002).
9.2.2.1 S. Cerevisiae
The integration of the expression cassette of the GDP-fucose transporter will be localized in the auxotrophy marker TRP1 for the S. cerevisiae strain. Invalidation of the gene TRP1 induces resistance to a toxic agent, 5-fluoro-anthranilic acid. The yeasts modified by this cassette will therefore become resistant to this drug but also auxotrophic for tryptophan.
Assembling the promoter SV40 cassette (PCR product), the ORF (PCR product) and the terminator CYC1 (PCR product)
BS136 (forward) and BS137 (reverse)
The PCR amplification was extracted and purified from agarose gel with the Qiagen kit and was introduced into a vector pTarget. Competent bacteria (JM109, Promega) were transformed with this vector. The transformation was checked by PCR and the insertion of the PCR amplification into the vector by sequencing (pGLY07.003).
9.2.2.2 S. Pombe
The expression cassette for the GDP-fucose transporter was produced in tandem with a cassette for resistance to an antibiotic, hygromycin. This double cassette is inserted in a gene coding for a protein involved in the maturation of N-glycans of S. pombe , GMA12. Insertion of this cassette in this locus will induce resistance to hygromycin but also the deletion of the gene gma12.
The expression cassette of the GDP-fucose transporter obtained previously is assembled with an expression cassette of resistance to hygromycin comprising the promoter of SV40, the ORF of the resistance to hygromycin as well as the terminator TEF. These tandem cassettes are inserted into the marker gma12.
9.2.3 Step 3: Modification of the Yeasts
Preparation of competent yeasts:
The Apolline and Epiphanie strains were prepared as indicated above in order to make them competent.
Electroporation of the yeasts Procedure: 20 μg of plasmids containing the expression cassettes for S. cerevisiae and S. pombe were digested by the restriction enzyme EcoRI. The linearized cassette was introduced into the yeasts Apolline and Epiphanie by electroporation. The S. cerevisiae yeasts are spread on an YPD medium containing 5-fluoro-anthranilic acid. The S. pombe yeasts are spread with limiting dilution on a gelosed YPD medium, the deleted marker not imparting resistance to a drug. Once the clones are released, replicates on a minimum medium are established in order to select the clones which cannot grow without the required amino acid.
Example 10
Athena and Etienne Strains+Expression Cassette of N-Acetylglucosaminyl-Transferase III
10.1 Obtaining the ORF
PCR from complementary DNA of murine brain
CB007 (forward) Atgaagatgagacgctacaa CB036 (reverse) ctagccctccactgtatc
Program:
2 minutes at 94° C. 30 cycles: 45 s at 94° C. 45 s at 56° C. 2 min at 72° C. 5 minutes at 72° C.
Amplification of a by fragment without the cytoplasmic portion of the enzyme: it will be replaced with the cytoplasmic portion of Mnt1 for Golgian localization of the protein.
10.2 Expression Cassette Assembling for the S. Cerevisiae and S. Pombe Strains
10.2.1 Assembling for S. Cerevisiae
Amplification of the promoter nmt1
CB013: tatagtcgctttgttaaatcatatggccctctttctcagtaa CB014: agcgaagactccgaagcccacttctttaagaccttatcc
Amplification of the terminator CYC1
Amplification of the expression cassette with the ends CAN1
CB030 (forward):
cagaaaatccgttccaagag
CB031 (reverse):
tgccacggtatttcaaagct
10.2.2 Assembling for S. Pombe
Expression cassette of GNTIII in tandem with a cassette for resistance to hygromycin. Insertion in GMA12.
10.3 Transformation of the Yeasts
Example 11
Deletion of Genes Involved in Hypermannosylation in S. Cerevisiae and S. Pombe
11.1 Step 1: Deletion of the Mnn1 Gene in the Yeasts Amélie, Arielle, Anaïs, Alice, Abel, Ashley, Athena, Azalée and Aurel
11.1.1 Construction and Insertion of a Cassette Containing a Gene for Resistance to Hygromycin into the Mnn1 Gene
11.1.1.1 Construction of the Expression Cassette
Amplification of the promoter CaMV with the Mnn1 5′ end
CB39: TTTATATTAAACCAAAGGTCTTTGAGATCGTGTACCATACTGCCTGCAGG TCAACATG CB40: TTCTCGACAGACGTCGCGGTGAGTTCAGGCTTTTTACCCATCCGGGGATC CTCTAGAGTC
Hygromycin-terminator TEF amplification with homology to the promoter CaMV and the Mnn1 3′ end
CB41: TTCATTTGGAGAGGACCTCGACTCTAGAGGATCCCCGGATGGGTAAAAAG CCTGAACTC CB42: GGTGTTATCTTTATTAGCATGTGACCAAACAGTGTTGACATCGACACTGG ATGGCGGCGTATGGGTAAAAAGCCTGAACTCACCGCGACGTCTGTCGAGA AGTTTCTGATCGAAAAGTTCGACAGCGTCTCCGACCTGATGCAGCTCTCG GAGGGCGAAGAATCTCGTGCTTTCAGCTTCGATGTAGGAGGGCGTGGATA TGTCCTGCGGGTAAATAGCTGCGCCGATGGTTTCTACAAAGATCGTTATG TTTATCGGCACTTTGCATCGGCCGCGCTCCCGATTCCGGAAGTGCTTGAC ATTGGGGAATTCAGCGAGAGCCTGACCTATTGCATCTCCCGCCGTGCACA GGGTGTCACGTTGCAAGACCTGCCTGAAACCGAACTGCCCGCTGTTCTGC AGCCGGTCGCGGAGGCCATGGATGCGATGGCTGCGGCCGATCTTAGCCAG ACGAGCGGGTTCGGCCCATTCGGACCGCAAGGGGCGTGATTTCATATGCG CGATTGCTGATCCCCATGTGTATCACTGGCAAACTGTGATGGACGACACG GTCAGTGCGTCCGTCGCGCAGGCTCTCGATGAGCTGATGCTTTGGGCCGA GGACTGCCCCGAAGTCCGGCACCTCGTGCACGCGGATTTCGGCTCCAACA ATGTCCTGACGGACAATGGCCGCATAACAGCGGTCATTGACTGGAGCGAG GCGATGTTCGGGGATTCCCAATACGAGGTCGCCAACATCTTCTTCTGGAG GCCGTGGTTGGCTTGTATGGAGCAGCAGACGCGCTACTTCGAGCGGAGGC ATCCGGAGCTTGCAGGATCGCCGCGGCTCCGGGCGTATATGCTCCGCATT GGTCTTGACCAACTCTATCAGAGCTTGGTTGACGGCAATTTCGATGATGC AGCTTGGGCGCAGGGTCGATGCGACGCAATCGTCCGATCCGGAGCCGGGA CTGTCGGGCGTACACAAATCGCCCGCAGAAGCGCGGCCGTCTGGACCGAT GGCTGTGTAGAAGTACTCGCCGATAGTGGAAACCGACGCCCCAGCACTCG TCCGAGGGCAAAGGAATAATCAGTACTGACAATAAAAAGATTCTTGTTTT CAAGAACTTGTCATTTGTATAGTTTTTTTATATTGTAGTTGTTCTATTTT AATCAAATGTTAGCGTGATTTATATTTTTTTTAGATGCGAAGTTAAGTGC GCAGAAAGTAATATCATGCGTCAATCGTATGTGAATGCTGGTCGCTATAC TGCTGTCGATTCGATACTAACGCCGCCATCCAGTGTCGa
Assembling the insertion cassette for deletion of the Mnn 1 gene in S. cerevisiae :
CB39:
TTTATATTAAACCAAAGGTCTTTGAGATCGTGTACCATACTGCCTGCAGG
TCAACATG
CB42:
GGTGTTATCTTTATTAGCATGTGACCAAACAGTGTTGACATCGACACTGG
ATGGCGGCGT
11.1.1.2 Transformation of the Yeasts
Preparation of competent yeasts:
The strains were prepared as indicated above in order to make them competent.
Electroporation of S. cerevisiae yeasts Procedure: 20 μg of the plasmids containing the expression cassettes for S. cerevisiae were digested by a restriction enzyme. The lenearized cassette was introduced into the yeasts by electroporation. The yeasts are selected on a YPD medium containing hygromycin.
11.1.2 Deletion of the Mnn9 Gene in the Yeasts Amélie, Arielle, Anaïs, Alice, Abel, Ashley, Athena, Azalée and Aurel
11.1.2.1 Construction of a Cassette for Integration Into the Mnn9 Gene Containing a Gene for Resistance to Phleomycin
Amplification of the promoter SV40 with the Mnn9 5′ enc
CB46: AAAGATCTTAACGTCGTCGACCATGTGGTTAAGCACGACGCAGGCAGAAG TATGCAAA CB47: AAATGTCGTGATGGCAGGTTGGGCGTCGCTTGGTCGGCCATAGCTTTTTG CAAAAGCCTAG
Phleomycin-terminator TEF amplification with homology to the promoter SV40
CB48:
GCTGTGGAATGTGIGTCAGTTAGGGTGTGGAAAGTCCCCAATGGCCGACC
AAGCGACGCCC
CB49:
GGTGTTATCTTTATTAGCATGTGAGCAAACAGTGTTGACATCGACACTGG
ATGGCGGCGT
atggccgaccaagcgacgcccaacctgccatcacgagatttcgattccac
ggccgccttctatgaaaggttgggcttcggaatcgttttccgggacgccg
gctggatgatcctccagcgcggggatctcaagctggagttcttcgcccac
cccgggctcgatcccctcgcgagttggttcagctgctgcctgaggctgga
cgacctcgcggagttctaccggcagtgcaaatccgtcggcatccaggaaa
ccagcagcggctatccgcgcatccatgcccccgaactgcaggagtgggga
ggcacgatggccgctttggtcgacccggacgggacgctcctgcgcctgat
acagaacgaattgcttgcaggcatctcatgatcagtactgacaataaaaa
gattcttgttttcaagaacttgtcatttgtatagtttttttatattgtag
ttgttctattttaatcaaatgttagcgtgatttatattttttttcgcctc
gacatcatctgcccagatgcgaagttaagtgcgcagaaagtaatatcatg
cgtcaatcgtatgtgaatgctggtcgctatactgctgtcgattcgatact
aacgccgccatccagtgtcgaaaacgagctctcgagaacccttaat
11.1.2.2 Transformation of the Yeasts
Preparation of competent yeasts:
The yeasts are prepared as indicated above in order to make them competent
Electroporation of S. cerevisiae yeasts Procedure: 20 μg of the plasmids containing the expression cassette for S. cerevisiae were digested by a restriction enzyme. The linearized cassette was introduced into the yeasts by electroporation. The yeasts are selected on a YPD medium containing phleomycin.
11.2 Step 2: Dejection of the GMA12 Gene in the Yeasts S. Pombe , Emma, Erika, Enrique, Elga, Etienne
11.2.1 Construction of the Integration Cassette Containing the Gene for Resistance to Hygromycin
ext-gma12/prom-CaMV/hph/Tef-term/ext-gma12
CB51:
CAAAGATCTTAACGTCGTCGACCATGTGCTTAAGCACGACTGGCTGCAGG
TGAACATG
CB52:
ATATGATCCTTTTCTTGAGCAGACATCCAATCGGATCCTTTCGACACTGG
ATGGCGGCGT
11.2.2 Transformation of the Yeasts
Preparation of competent yeasts:
The strains are prepared as indicated above in order to make them competent.
Electroporation of S. cerevisiae yeasts. Procedure: 20 μg of the plasmids containing the expression cassette for S. pombe were digested by a restriction enzyme. The linearized cassette was introduced by electroporation. The yeasts are selected on an YPD medium containing hygromycin.
Example 12
Strains+Expression Cassettes for Sialylation of the N-Glycans of S. Cerevisiae and S. Pombe
With the purpose of obtaining effective sialylation of N-glycans of proteins produced in S. cerevisiae and S. pombe , first of all the biosynthesis route for sialic acid has to be introduced into the same yeasts. To do this, we introduced into the genome of the yeasts, the route for the biosynthesis of CMP-sialic acid of N. meningitidis , enzymes localized in the cytosol. Preparation of cassettes in tandem for sialylation (from the strains Athena, Aurel and Azalée):
12.1 Cassette S1
Construction of a tandem cassette consisting of the promoter PET56, of the ORF of sialic acid synthase, of the terminator CYC1 and then of the promoter PET565, of the ORF of CMP-sialic acid synthase and of the terminator CYC1.
Obtaining the ORFs:
Sialic acid synthase (1,050 bp)
Atgcaaaacaacaacgaatttaaaattggtaatcgttcagtaggttacaa ccacgaaccattgattatctgtgaaatcggcatcaatcatgaaggctctt taaaaacagcttttgaaatggttgatgctgcctataatgcaggcgctgaa gttgttaaacatcaaacacacatcgttgaagacgaaatgtctgatgaggc caaacaagtcattccaggcaatgcagatgtctctatttatgaaattatgg aacgttgcgccctgaatgaagaagatgagattaaattaaaagaatacgta gagagtaagggtatgatttttatcagtactcctttctctcgtgcagctgc tttacgattacaacgtatggatattccagcatataaaatcggctctggcg aatgtaataactacccattaattaaactggtggcctcttttggtaagcct attattctctctaccggcatgaattctattgaaagcatcaaaaagtcggt agaaattattcgagaagcaggggtaccttatgctttgcttcactgtacca acatctacccaaccccttacgaagatgttcgattgggtggtatgaacgat ttatctgaagcctttccagacgcaatcattggcctgtctgaccatacctt agataactatgcttgcttaggagcagtagctttaggcggttcgattttag agcgtcactttactgaccgcatggatcgcccaggtccggatattgtatgc tctatgaatccggatacttttaaagagctcaagcaaggcgctcatgcttt aaaattggcacgcggcggcaaaaaagacacgattatcgcgggagaaaagc caactaaagatttcgcctttgcatctgtcgtagcagataaagacattaaa aaaggagaactgttgtccggagataacctatgggttaaacgcccaggcaa tggagacttcagcgtcaacgaatatgaaacattatttggtaaggtcgctg cttgcaatattcgcaaaggtgctcaaatcaaaaaaactgatattgaataa
CMP-sialic acid synthase (687 bp):
atggaaaaacaaaatattgcggttatacttgcgcgccaaaactccaaagg
attgccattaaaaaatctccggaaaatgaatggcatatcattacttggtc
atacaattaatgctgctatatcatcaaagtgttttgaccgcataattgtt
tcgactgatggcgggttaattgcagaagaagctaaaaatttcggtgtcga
agtcgtcctacgccctgcagagctggcctccgatacagccagctctattt
caggtgtaatacatgctttagaaacaattggcagtaattccggcacagta
accctattacaaccaaccagtccattacgcacaggggctcatattcgtga
agctttttctctatttgatgagaaaataaaaggatccgttgtctctgcat
gcccaatggagcatcatccactaaaaaccctgcttcaaatcaataatggc
gaatatgcccccatgcgccatctaagcgatttggagcagcctcgccaaca
attacctcaggcatttaggcctaatggtgcaatttacattaatgatactg
cttcactaattgcaaataattgtttttttatcgctccaaccaaactttat
attatgtctcatcaagactctatcgatattgatactgagcttgatttaca
acaggcagaaaacattcttaatcacaaggaaagctaa
Expression cassette:
Promoter PET56
CTTTGCCTTCGTTTATCTTGCCTGCTCATTTTTTAGTATATTCTTCGAAG
AAATCACATTACTTTATATAATGTATAATTCATTATGTGATAATGCCAAT
CGCTAAGAAAAAAAAAGAGTCATCCGCTAGGTGGAAAAAAAAAAATGAAA
ATCATTACCGAGGCATAAAAAAATATAGAGTGTACTAGAGGAGGCCAAGA
GTAATAGAAAAAGAAAATTGCGGGAAAGGACTGTGTT
12.2 Cassette S2
The expression cassette of the CMP-sialic acid transporter was produced in tandem with a cassette for resistance to an antibiotic, hygromycin. This double cassette is inserted into the mnn1 gene. Insertion of this cassette into this locus will induce resistance to hygromycin but also the deletion of the mnn1 gene.
Obtaining the ORF
CMP-sialic acid transporter from mus musculus (1,011 bp)
atggctccggcgagagaaaatgtcagtttattcttcaagctgtactgctt
ggcggtgatgactctggtggctgccgcttacaccgtagctttaagataca
caaggacaacagctgaagaactctacttctcaaccactgccgtgtgtatc
acagaagtgataaagttactgataagtgttggcctgttagctaaggaaac
tggcagtttgggtagatttaaagcctcattaagtgaaaatgtcttgggga
gccccaaggaactggcgaagttgagtgtgccatcactagtgtatgctgtg
cagaacaacatggccttcctggctctcagtaatctggatgcagcagtgta
ccaggtgacctatcaactgaagatcccctgcactgctttatgtactgttt
taatgttaaatcgaacactcagcaaattacagtggatttccgtcttcatg
ctgtgtggtggggtcacactcgtacagtggaaaccagcccaagcttcaaa
agtcgtggtagcgcagaatccattgttaggctttggtgctatagctattg
ctgtattgtgctctggatttgcaggagtttattttgaaaaagtcttaaag
agttccgacacttccctttgggtgagaaacattcagatgtatctgtcagg
gatcgttgtgacgttagctggtacctacttgtcagatggagctgaaattc
aagaaaaaggattcttctatggctacacgtattatgtctggtttgttatc
ttccttgctagtgtgggaggcctctacacgtcagtggtggtgaagtatac
agacaacatcatgaaaggcttctctgctgccgcagccattgttctttcta
ccattgcttcagtcctactgtttggattacagataacactttcatttgca
ctgggagctcttcttgtgtgtgtttccatatatctctatgggttacccag
acaagatactacatccattcaacaagaagcaacttcaaaagagagaatca
ttggtgtgtga
Construction of the expression cassette:
The expression cassette of the CMP-sialic acid transporter (promoter CaMV, ORF, terminator CYC1) is assembled with an expression cassette of resistance to hygromycin comprising the promoter of CaMV, the ORF of the resistance to hygromycin, as well as the terminator TEF. These tandem cassettes are inserted into the marker mnn1.
12.3 Cassette S3
The expression cassette for sialyl transferase ST3GAL4 was produced in tandem with a cassette for resistance to an antibiotic, phleomycin. This double cassette is inserted into the gene mnn9. Insertion of this cassette into the locus will induce resistance to hygromycin but also deletion of the mnn9 gene.
Obtaining the ORF
Human sialyl transferase ST3GAL4 (990 bp)
atggtcagcaagtcccgctggaagctcctggccatgttggctctggtcct ggtcgtcatggtgtggtattccatctcccgggaagacagtttttattttc ccatcccagagaagaaggagccgtgcctccagggtgaggcagagagcaag gcctctaagctctttggcaactactcccgggatcagcccatcttcctgcg gcttgaggattatttctgggtcaagacgccatctgcttacgagctgccct atgggaccaaggggagtgaggatctgctcctccgggtgctagccatcacc agctcctccatccccaagaacatccagagcctcaggtgccgccgctgtgt ggtcgtggggaacgggcaccggctgcggaacagctcactgggagatgcca tcaacaagtacgatgtggtcatcagattgaacaatgccccagtggctggc tatgagggtgacgtgggctccaagaccaccatgcgtctcttctaccctga atctgcccacttcgaccccaaagtagaaaacaacccagacacactcctcg tcctggtagctttcaaggcaatggacttccactggattgagaccatcctg agtgataagaagcgggtgcgaaagggtttctggaaacagcctcccctcat ctgggatgtcaatcctaaacagattcggattctcaaccccttcttcatgg agattgcagctgacaaactgctgagcctgccaatgcaacagccacggaag attaagcagaagcccaccacgggcctgttggccatcacgctggccctcca cctctgtgacttggtgcacattgccggctttggctacccagacgcctaca acaagaagcagaccattcactactatgagcagatcacgctcaagtccatg gcggggtcaggccataatgtctcccaagaggccctggccattaagcggat gctggagatgggagctatcaagaacctcacgtccttctga
Murine sialyl transferase ST3GAL4 (1,002 bp)
atgaccagcaaatctcactggaagctcctggccctggctctggtccttgt
tgttgtcatggtgtggtattccatctcccgagaagataggtacattgagt
tcttttattttcccatctcagagaagaaagagccatgcttccagggtgag
gcagagagacaggcctctaagatttttggcaaccgttctagggaacagcc
catctttctgcagcttaaggattatttttgggtaaagacgccatccacct
atgagctgccctttgggactaaaggaagtgaagaccttcttctccgggtg
ctggccatcactagctattctatacctgagagcataaagagcctcgagtg
tcgtcgctgtgttgtggtgggaaatgggcaccggttgcggaacagctcgc
tgggcggtgtcatcaacaagtacgacgtggtcatcagattgaacaatgct
cctgtggctggctacgagggagatgtgggctccaagaccaccatacgtct
cttctatcctgagtcggcccactttgaccctaaaatagaaaacaacccag
acacgctcttggtcctggtagctttcaaggcgatggacttccactggatt
gagaccatcttgagtgataagaagcgggtgcgaaaaggcttctggaaaca
gcctcccctcatctgggatgtcaaccccaaacaggtccggattctaaacc
ccttctttatggagattgcagcagacaagctcctgagcctgcccatacaa
cagcctcgaaagatcaagcagaagccaaccacgggtctgctagccatcac
cttggctctacacctctgcgacttagtgcacattgctggctttggctatc
cagatgcctccaacaagaagcagaccatccactactatgaacagatcaca
cttaagtctatggcgggatcaggccataatgtctcccaagaggctatcgc
catcaagcggatgctagagatgggagctgtcaagaacctcacatacttct
ga
The expression cassette of the CMP-sialic acid transporter (promoter CaMV, ORF, terminator CYC1) is assembled with an expression cassette of resistance to hygromycin comprising the promoter of CaMV, the ORF of the resistance to hygromycin as well as the terminator TEF. These tandem cassettes are inserted into the marker mnn1.
Example 13
Production of Homogeneously Glycosylated EPO
13.1 Amplification of the Nucleotide Sequence of Human Erythropoietin (EPO)
Amplification of the nucleotide sequence of human EPO was obtained from complementary DNA of human kidney with suitable primers.
13.2 Cloning of the Sequence of the EPO in an Expression Vector of S. Cerevisiae
The nucleotide sequence of human huEPO truncated of its STOP codon (585 base pairs) is integrated into an expression vector of the yeast S. cerevisiae . The continuity of the reading frame between the introduced sequence and the sequence of the plasmid pSC (epitope V5 and poly-histidine tag) was confirmed by sequencing the obtained plasmid (pSC-EPO). The expression of the protein EPO is found under the control of the promoter pGAL1, a promoter inducible by galactose for S. cerevisiae strains. The selection of the yeasts having the plasmid is performed by return of prototrophy for uracil (presence of the URA3 sequence in the plasmid).
Sequence obtained in the expression plasmid:
(SEQ ID No 11) 1 ATGGGGGTGC ACGAATGTCC TGCCTGGCTG TGGCTTCTCC TGTCCCTGCT 51 GTCGCTCCCT CTGGGCCTCC CAGTCCTGGG CGCCCCACCA CGCCTCATCT 101 GTGACAGCCG AGTCCTGGAG AGGTACCTCT TGGAGGCCAA GGAGGCCGAG 151 AATATCACGA CGGGCTGTGC TGAACACTGC AGCTTGAATG AGAATATCAC 201 TGTCCCAGAC ACCAAAGTTA ATTTCTATGC CTGGAAGAGG ATGGAGGTCG 251 GGCAGCAGGC CGTAGAAGTC TGGCAGGGCC TGGCCCTGCT GTCGGAAGCT 301 GTCCTGCGGG GCCAGGCCCT GTTGGTCAAC TCTTCCCAGC CGTGGGAGCC 351 CCTGCAGCTG CATGTGGATA AAGCCGTCAG TGGCCTTCGC AGCCTCACCA 401 CTCTGCTTCG GGCTCTGGGA GCCCAGAAGG AAGCCATCTC CCCTCCAGAT 451 GCAGCCTCAG CTGCTCCGCT CCGAACAATC ACTGCTGACA CTTTCCGCAA 501 ACTCTTCCGA GTCTACTCCA ATTTCCTCCG GGGAAAGCTG AAGCTGTACA 551 CAGGGGAGGC CTGCAGGACA GGCGACAGA A AGGGCGAGCT TCGAGGTCAC 601 CCATTCGAAG GTAAGCCTAT CCCTAACCCT CTCCTCGGTC TCGATTCTAC 651 GCGTACCGGT CATCATCACC ATCACCAT TG A
Protein sequence of the sequenced EPO in the expression plasmid (SEQ ID No 12)
MGVHEGPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAE
NITTGCAEHCSLNENITVPDTKVNFYAWKRMEVGQQAVEVWQGLALLSEA
VLRGQALLVNSSQPWEPQLHVDKAVSGLRSLTTLLRALGAQKEAISPPDA
ASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDRKGELRGHP
FEGKPIPNPLLGLDSTRTGHHHHHH*
Epitope V5 poly-HIS
13.3 Extraction of the RNAs
Centrifuge the yeasts 16000 g for 5 min. Remove the supernatant and re-suspend the pellets in 500 μL of TES buffer (10 mM TrisHCl pH7.5 10 mM EDTA, 0.5% SDS). Add 200 μL of phenol and 200 μL of chloroform and then incubate for 20 min at 65° C. by vortexing for 30 s every 5 min and incubate for 1 hr at −80° C. Centrifuge for 20 min at 13,200 rpm and then recover the aqueous phase and add 335 μL of phenol and 67 μL of chloroform. Vortex and centrifuge for 5 min at 11,000 rpm. Recover the aqueous phase and add 300 μL of chloroform. Vortex and centrifuge for 2 min at 13,200 rpm. Recover the aqueous phase and add 30 μL of 3M sodium acetate at pH 5.2 and 600 μL of absolute ethanol. Incubate for 1 hr at −20° C. Centrifuge for 15 min at 13,200 rpm. Remove the supernatant while being careful with the pellet. Leave them to dry, take them up in 100 μL of EDPC water and then place them in a tube containing the violet Nucleospin (Nucleospin RVAII) filtration unit. Centrifuge for 1 min at 11,000 g. Remove the filter and add 350 μL of 70% ethanol. Load the Nucleospin RNAII column. Centrifuge for 30 s at 8000 g. Place the column in a new tube, add 350 μL of Membrane Desalting Buffer. Centrifuge for 1 min at 11,000 g. Deposit 95 μL of DNase solution at the centre of the column, and then incubate for 15 min at room temperature. Add 200 μL of RA2 solution (inactivate the DNase) and centrifuge for 30 s at 8,000 g. Add 600 μL of RA3 solution to the centre of the column. Centrifuge for 30 s at 8,000 g. Place the column in a new tube, add 250 μL of RA3 solution. Centrifuge for 2 min at 11,000 g in order to drive the column. Place the column in a 1.5 nL tube and add 50 μL of DEPC water. Centrifuge for 1 min at 11,000 g. Store the samples at −80° C.
13.4 Reverse transcription: Super Script III First-Strand Synthesis System for RT-PCR
5 μg of RNA At most 8 μL Random hexamer 50 ng/μL 1 μL dNTP mix 10 mM 1 μL DEPC water qsp 10 μL Incubate for 5 min at 65° C. Add 10 μL of transcription mix: RT Buffer 10X 2 μL MgCl 2 25 mM 4 μL DTT 0.1M 2 μL RNase Out 40 U/μL 1 μL SuperScript 200 U/μL 1 μL Incubate For 10 min at 25° C. For 50 min at 50° C. For 5 min at 85° C.
Recover in ice and add 1 μL of RNaseH. Leave to incubate for 20 min at 37° C. and then store the cDNAs at −20° C.
13.5 Extraction of the Proteins
After centrifugation at 1,500 g for 5 min at 4° C., the cell pellet is taken up in 500 μL of sterile H 2 O and then centrifuged at maximum speed for 30 s at 4° C. The pellet is taken up into 500 μL of sodium phosphate 50 mM lysis buffer, pH 7.4, 5% glycerol, 1 mM PMSF, centrifuge for 10 min at 1,500 g at 4° C. The pellet is then taken up in a volume of lysis buffer required for obtaining an OD comprised between 50 and 100. The samples are then vortexed for 4×30 s with glass beads and centrifugation for 10 min at maximum speed is carried out in order to separate the beads and the cell debris from the protein supernatant. A BCA assay is carried out on the supernatant.
13.6 Purification of EPO
The total proteins are first of all dialyzed against the 10 mM Tris HCl buffer, pH 6.0. After equilibration of a cation exchanger SP Sephadex C50 column with 10 mM Tris-HCl pH 6.0, the total dialyzed proteins are loaded on the column. After rinsing the column with 10 mM Tris HCl buffer pH 6.0, the proteins are eluted with 10 mM Tris HCl buffer pH 6.0, 250 mM NaCl. The absorbance of each fraction is determined at 280 nm as well as the amount of proteins eluted by a Bradford assay. The proteins are then analyzed by SDS-PAGE electrophoresis on 12% acrylamide gel.
13.7 Detection of the EPO Protein—Western Blot
The total proteins are transferred onto a nitrocellulose membrane in order to proceed with detection by the anti-EPO antibody (R&D Systems). After the transfer, the membrane is saturated with a blocking solution (TBS, 1% blocking solution (Roche)) for 1 hour. The membrane is then put into contact with the anti-EPO antibody solution (dilution 1:500) for 1 hour. After three rinses with 0.1% Tween 20-TBS the membrane is put into contact with the secondary anti-mouse-HRP antibody in order to proceed with detection by chemiluminescence (Roche detection solution).
141. Results
14.1: Validation of the Clones Having Integrated the Kanamycin Cassette in the Och1 Gene
For suppressing the Och1 activity, the introduced cassette was entirely sequenced after its integration in order to map the affected genomic region in the genome of the yeast. Absence of enzymatic activity is then achieved, enhancing the previous results, and then the structure of the glycans is determined by mass spectrometry.
The analysis on 1% agarose-TBE gel of the PCR reaction carried out from genomic DNA of S. cerevisiae clones having resisted to the presence of kanamycin in the culture medium shows an amplified 2 kb fragment with a specific pair of oligonucleotides of the kanamycin cassette. The size of this fragment corresponds to the theoretical size of the kanamycin cassette. The second fragment was amplified by means of an oligonucleotide internal to the kanamycin cassette and an oligonucleotide external to the cassette hybridizing with the Och1 gene. The theoretical size of the expected fragment is 1.5 kb which corresponds to the size of the obtained fragment. We may therefore conclude that the clones 1, 2, 3 and 4 have actually integrated the kanamycin cassette and that the latter was integrated into the Och1 gene (see FIG. 3 ).
The same type of PCR reaction was carried out on the S. pombe strains having resisted to the presence of kanamycin in the culture medium. Thus, two mutated clones of each strain were isolated and tested for loss of α1,6-mannosyl transferase enzymatic activity.
Test of Mannosyl Transferase Och1 Activity on Strains of Mutated Yeasts
Validation of the loss of Och1 activity in the mutant Δoch1 obtained by homologous recombination in the S. cerevisiae and S. pombe yeasts:
After validation by PCR of the insertion of the expression cassette of kanamycin in wild S. cerevisiae and wild S. pombe yeasts, the positive clones to this insertion are tested for their loss of mannosyl transferase Och1 activity. The Och1 activity was tested on microsomes of the S. cerevisiae and S. pombe yeasts. FIG. 4 shows the Och1 activity test on a—the microsomal fraction of the wild strain and of the selected clones of S. cerevisiae , b—the microsomal fraction of the wild strain and of selected clones of S. pombe . According to FIG. 4 , we may observe a loss of activity of the Och1 enzyme in the selected clones of S. cerevisiae (a) and S. pombe (b).
Validation of the Strains by Analyses of N-Glycans
The total proteins from both modified strains were reduced and alkylated and then digested by trypsin. The free polysaccharides are removed by passing over SepPak C18. The recovered peptides and glycopeptides are subject to PNGase. The glycans are purified on SepPak C18 and then methylated before being analyzed by mass spectrometry in the Maldi-Tof mode. FIG. 5 shows the mass spectrum carried on N-glycans from the strains Adele and Edgar.
Nomenclature of the Yeasts:
S. cerevisiae Δoch1=Adèle
S. pombe Δoch1=Edgar
Both strains have N-glycans with oligomannoside forms from Man 7 to Man 10 , shorter forms than in the wild strain of Saccharomyces cerevisiae indicating the loss of wild polymannosylated forms.
The predominant structures for the Edgar strain (Δoch1) are Man 9 and Man 8 , structures which are conventionally encountered in mammals after transit of the neosynthesized protein into the endoplasmic reticulum. This suggests blocking of glycosylation due to the impossibility of action of the Golgian mannosyl transferases which only graft mannose on glycans on which the enzyme Och1 has grafted a mannose attached in the α1,6 position.
14.2: Validation of the Clones Having Integrated the Mannosidase I Cassette into the URA3 Gene
The Adèle and Edgar yeasts, positive for the insertion of the expression cassette of mannosidase I in the gene URA3, are tested for their mannosidase I biochemical activity. FIG. 6 shows the assay of mannosidase activity in microsomes of S. cerevisiae and S. pombe yeasts. The experiment was conducted in triplicate. We may observe in the wild S. cerevisiae and S. pombe strains, a mannosidase activity non-inhibited by DMJ. Conversely, the selected strains have significant inhibition of mannosidase activity measured during a DMJ treatment. Further, as the measured mannosidase I activity is present in the microsomes of yeasts, we may infer that this enzyme is expressed in the secretion route at the cis-Golgi/endoplasmic reticulum, indicating that the HDEL retention signal integrated in the C-terminus of the protein is well recognized by the cell system.
Nomenclature of the Yeasts:
S. cerevisiae Adèle+mannosidase I =Amélie
S. pombe Edgar+mannosidase I =Emma
14.3 Validation of the Clones Having Integrated the N-Acetylglucosaminyl Transferase (GlcNAc Transferase I) Cassette in the Modified Yeasts
FIG. 7 shows the GlcNAcTransferase I activity in microsomes of wild and modified yeasts.
In the microsomes or fractions of the Amélie-GlcNacTI and Emma-GlcNacTI yeasts, we observe an increase in the labeling of the acceptor by transfer of a radioactive GlcNAc group compared with the labeling observed in control yeasts (wild and/or Δoch1-MdseI yeasts). This transfer involves the presence of N-acetylglucosaminyl transferase activity in the yeasts modified by expression of GlcNAcTI.
Nomenclature of the Modified Yeasts:
S. cerevisiae Amélie+GlcNAcTI=Agathe
S. pombe Emma+GlcNAcTI=Egée
14.4 Validation of the Clones Having Integrated the Cassette of the UDP-GlcNAc Transporter in the Modified Yeasts
The expression of the UDP-GlcNAc transporter was analyzed by RT-PCR on parent or modified yeast cultures. After a reverse transcription step on the total extracted RNAs, the cDNAs were analyzed by PCR by using specific primers of the UDP-GlcNAc transporter (nested PCR). Therefore, an expression of the mRNA of this transporter is observed in the yeasts modified by the expression cassette of the UDP-GlcNAc transporter ( FIG. 8 ).
Nomenclature of the Modified Yeasts:
S. cerevisiae Agathe+UDP-GlcNAc transporter=Arielle
S. pombe Egée+UDP-GlcNAc transporter=Erika
14.5 Validation of Clones Having Integrated the Cassette of Mannosidase II in the Modified Yeasts
a—Validation by PCR Amplification
The selected clones for S. cerevisiae and S. pombe were tested by PCR in order to check the presence of expression cassettes of mannosidase II in the genome of the yeasts.
b—Expression of Mannosidase II
The expression of mannosidase II was analyzed by RT-PCR on parent or modified yeast cultures. After a step of reverse transcription on the extracted RNAs, the cDNAs were analyzed by PCR by using specific mannosidase II primers (nested PCR). In the yeasts modified by the expression cassette of mannosidase II an expression of the mRNA of this protein is therefore observed.
c—Measurement of the Activity of Mannosidase II
The Adèle and Edgar yeasts, positive for insertion of the expression cassette of mannosidase II, are tested for their mannosidase II biochemical activity.
According to FIG. 9 , we may observe in the parent S. cerevisiae and S. pombe strains a mannosidase activity insensitive to the inhibitory action of swainsonine. Conversely, the selected strains have significant inhibition of mannosidase activity measured upon treatment with swainsonine. Further as, the measured mannosidase II activity is detected in Golgian yeast fractions, we may infer that this enzyme is properly expressed in the secretion route at the Golgian system.
Nomenclature of the Modified Yeasts:
S. cerevisiae Arielle+Mannosidase II =Anaïs
S. pombe Erika+Mannosidase II =Enrique
14.6 Validation of the Clones Having Integrated the N-Acetylglucosaminyl Transferase II Cassette (GlcNAc Transferase II) in Modified Yeasts
a—Validation by PCR Amplification
The clones selected for S. cerevisiae and S. pombe were tested by PCR in order to check for the presence of expression cassettes of the GlcNAc transferase II in the genome of the yeasts (results not shown).
b—Expression of GlcNAc Transferase II
The expression of GlcNAc transferase II was analyzed by RT-PCR on parent or modified yeast cultures. After a step of reverse transcription on the extracted RNAs, the cDNAs were analyzed by PCR by using specific primers of GlcNAc transferase II (nested PCR). An expression of the transcribed mRNA is therefore observed in the yeasts modified by the expression cassette of GlcNAc transferase II (results not shown).
Nomenclature of the Modified Yeasts:
S. cerevisiae Anaïs+GlcNAc transferase II =Alice
S. pombe Enrique+GlcNAc transferase II =Elga
14.7 Validation of the Clones Having Integrated the Galactosyl Transferase I Cassette
a—Validation by PCR Amplification
The clones selected for S. cerevisiae and S. pombe were tested by PCR in order to check for the presence of expression cassettes of the GalTI in the genome of the yeasts (results not shown).
b—Expression of Galactosyl Transferase I
The expression of GalTI was analyzed by RT-PCR on parent or modified yeast cultures. After a step of reverse transcription on the extracted RNAs, the cDNAs were analyzed by PCR by using specific primers of GalTI (nested PCR). An expression of the transcribed mRNA is therefore observed in the yeasts modified by the expression cassette of GalTI (results not shown).
c—Activity of the GalTI
After extraction of the total proteins of the modified yeasts, 2 μg of proteins are deposited on a nitrocellulose membrane. The membrane is then incubated with erythrina cristagalli lectin coupled with biotin, a lectin specifically recognizing the galactose of the Gal-β-1,4-GlcNAc unit present on glycans of glycoproteins. The membrane is put into contact with streptavidin coupled to horse radish peroxidase (HRP) in order to proceed with detection by chemiluminescence (Roche detection solution).
14.8 Validation of the Clones Having Integrated the Cassette of the GDP-Fucose Transporter
a—Validation by PCR Amplification
The clones selected for S. cerevisiae and S. pombe were tested by PCR in order to check for the presence of expression cassettes of the GDP-fucose transporter in the genome of the yeasts.
b—Expression of GDP-Fucose Transporter
The expression of GDP-fucose transporter was analyzed by RT-PCR on parent modified yeast cultures. After a step of reverse transcription on the extracted RNAs, the cDNAs were analyzed by PCR by using specific primers of the GDP-fucose transporter (nested PCR). An expression of the transcribed mRNA is therefore observed in the yeasts modified by the expression cassette of GDP-fucose transporter ( FIG. 10 ).
Nomenclature of the Modified Yeasts:
S. cerevisiae Anaïs+GDP-fucose transporter=Apolline
S. pombe Enrique+GDP-fucose transporter=Epiphanie
14.9 Validation of the Clones Having Integrated the Cassette of Fucosyl Transferase 8 (FUT8)
a—Validation by PCR Amplification
The clones selected for S. cerevisiae and S. pombe were tested by PCR in order to check for the presence of expression cassettes of FUT8 in the genome of the yeasts.
b—Expression of the FUT8
The expression of the FUT8 was analyzed by RT-PCR on parent or modified yeast cultures. After a step of reverse transcription on the extracted RNAs, the cDNAs were analyzed by PCR by using specific primers of FUT8 (nested PCR). An expression of the transcribed mRNA is therefore observed in the yeasts modified by the expression cassette of FUT8 (results not shown).
Nomenclature of the Modified Yeasts:
S. cerevisiae Apolline+FUT8=Ashley
S. pombe Epiphanie+FUT8=Esther
14.10 Particular Case of EPO Expression in the Amélie Strain
The Amélie strain has the capability of exclusively producing the N-glycan Man 5 GlcNAc 2 ( FIG. 11 ), a structure encountered in mammals, described as a glycan of a simple type; and being used as a basis for elaborating more complex glycans bearing galactose, fucose or sialic acid. The presence of each genomic modification in this strain is described above. Each of these steps enters a “package” of verifications consisting of selecting the best producing clone and of maximizing the percentage of chances in order to obtain an exploitable clone. The method used allows a complete control of the genetic modification procedure: the sequence to be integrated is perfectly known, just like the target genomic region of the future integration. The latter site is moreover subject to extensive research as to the effects of possible breakage, this is why the whole of the targets is finally selected for the absence of phenotype effects obtained after their breakage.
An entire procedure for tracking the genomic stability of the producing clones is performed: after each production: regular planting out of the clones on the drastic media initially used for their selection, and starting out again the validation procedure. All the expression cassettes are cloned so that in the case of genomic rearrangement of a given strain, it may be proceeded with genetic upgrade of the organism. The procedures for integrating cassettes are not standardized and it is possible to imagine production of the strains “on demand” in order to achieve specific glycosylation, as ordered by the user.
The Amélie strain is the clone which should be used as a basis for elaborating any other strain intended for producing humanized hybrid or complex glycans.
The plasmid used for the expression of EPO in the modified yeasts contains the promoter Gal1. This promoter is one of the strongest promoters known in S. cerevisiae and is currently used for producing recombinant proteins. This promoter is induced by galactose and repressed by glucose. Indeed, in a culture of S. cerevisiae yeasts in glycerol, addition of galactose allows induction of the GAL genes by about 1,000 times. If glucose is added to this culture in the presence of galactose, the GAL genes will no longer be induced, only to 1% of the level obtained with galactose alone (Johnston, M. (1987) Microbiol. Rev.). The integrated sequence of human EPO in our plasmid was modified in 5′ by adding an epitope V5 as well as a polyhistidine tag in order to facilitate detection and purification of the produced protein.
The yeasts used for producing human EPO are first of all cultivated in a uracil drop out YNB medium, 2% glucose until an OD>12 is reached. After 24-48 hours of culture, 2% galactose is added to the culture in order to induce the production of our protein of interest. Samples are taken after 0, 6, 24 and 48 hours of induction.
Expression of the mRNA of EPO in Modified Yeasts
RT-PCR analysis of the total extracted RNAs shows expression of the messenger RNA or EPO in the clones of yeasts transformed after induction by galactose ( FIG. 12 bands 1 and 3) unlike what is observed in yeasts modified without induction by galactose ( FIG. 12 bands 2 and 4). The presence of galactose therefore causes induction of the transcription of the EPO gene. The sequencing of this amplified fragment confirms the production of a proper mRNA.
Purification of the EPO Protein Expressed in the Modified Yeasts
The total proteins obtained after induction of the expression of the rhuEPO protein by galactose are then deposited on a Sephadex C50 resin equilibrated to pH 6. Absorbance at 280 nm is determined at the column outlet ( FIG. 13 ). The proteins eluted from the column are analyzed by SDS-PAGE electrophoresis on 12% acrylamide gel.
After migration of the SDS-PAGE gel, analysis of the proteins is accomplished either by staining with Coomassie blue ( FIG. 14 ) or by western blot. In this case, the proteins are transferred on a nitrocellulose membrane in order to proceed with detection by the anti-EPO antibody (R&D Systems).
FIG. 15 shows the presence of a protein at about 35 kDa. This protein is the majority protein in Coomassie staining and is revealed by an anti-EPO antibody in a western blot analysis (tube 29 at the column outlet).
All these results therefore show production of EPO protein by genetically modified yeasts.
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The present application relates to genetically modified yeasts for the production of glycoproteins having optimized and homogeneous glycan structures. These yeasts comprise an inactivation of the Och 1 gene, the integration by homologous recombination, into an auxotrophic marker, of an expression cassette comprising a first promoter, and an open reading frame comprising the coding sequence for an α-1,2-mannosidase I, and the integration of a cassette comprising a second promoter different from said first promoter and the coding sequence for an exogenous glycoprotein. These yeasts make it possible to produce EPO with an optimized and 98% homogeneous glycosylation.
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This is a continuation-in-part of application Ser. No. 08/543,220 filed Oct. 13, 1995 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to the improvement of the quality of a multiple coated cellulosic sheet material which is prepared by applying, to a cellulosic sheet material base, two or more layers of a mineral pigment-containing coating composition to form a bonded unitary structure having suitable surface properties.
If a high quality printed image is to be applied to a cellulosic sheet material such as paper or cardboard it is generally necessary to apply to the surface at least one coating composition layer containing one or more mineral pigments such as kaolin clay, calcium carbonate, calcium sulphate, titanium dioxide, barium sulphate, satin white and the like. The application of such a coating composition layer improves the smoothness, gloss, whiteness and opacity of the surface to which the printed image is to be applied. In many cases, in order to obtain a final coated surface of the desired quality, it is necessary to apply two or more layers of pigment-containing coating compositions. For example, a first coating composition layer may be employed to smooth the profile roughness of and cover voids present in the base cellulosic layer and a second coating composition may be employed to adhere to and coat the first layer and to give a better quality surface finish than the first layer and/or complete the pigment coverage or `hiding` of the underlying base provided by the first layer especially where that is relatively dark, eg. comprising board. The materials of the two or more coating composition layers may be the same or different. Generally, they are different. The pigment material of the outer layer is usually finer and more expensive than that of the first coating composition applied. In any event, the resulting product eventually comprises multiple inseparable layers bonded together as a unitary structure providing a high quality surface on at least one side to which a printed image may be applied.
Paper coating composition layers are applied in a well known way using coating machinery, eg. in which the coating composition is applied to the underlying layer by a so called `doctor blade`. Generally, in order to receive the maximum return from capital invested in paper coating machinery, it is desirable to run the coating machine at the highest practicable web speed. Also, since the coating compositions consist of pigment, adhesives, and possibly other solid ingredients in suspension in water, it is necessary to remove the water content of the composition by thermal evaporation in order to dry the coatings. In order to minimize the consumption of energy for thermal evaporation it is desirable to operate with coating compositions having the highest possible solids concentrations. However, it is found that when a final coating composition of relatively high solids concentration is applied to a base sheet of relatively high water absorbency, there is a tendency, when a doctor blade is used to remove excess coating composition and smooth the coating, for this final coating to be marred by scratches and other defects.
Where such scratches and defects occur it can be very costly to the manufacturer, since the machinery will need to be stopped sometimes for considerable periods of time, to correct the fault. The general ability to use a paper coating composition continuously in a paper coating operation without difficulty is known in the art as "runnability". Another problem which occurs in the manufacture of multiple coated paper and like products is to obtain good adhesion of an outer coating composition layer to an underlying coating composition layer on a cellulosic sheet. This is because the underlying coating composition layer will usually have a smoothness which is much improved compared with the underlying cellulosic sheet and it is difficult to ensure that the outer layer keys onto the surface of the smoother underlying layer.
An object of the present invention is to provide a method of depositing multiple layers of pigment-containing coating compositions on a base cellulosic sheet in a manner in which the runnability of the product may be improved without significantly interfering with the adhesion between the coating layers.
SUMMARY OF THE PRESENT INVENTION
According to the present invention there is provided a method of producing a multiple coated cellulosic sheet product having a surface which is smooth, bright and capable of being printed upon, the method comprising the steps of coating a substrate comprising a cellulosic sheet with a first layer of an inorganic pigment-containing aqueous coating composition, and coating the first layer with a second layer of an inorganic pigment-containing aqueous coating composition to form a product in which the first layer is bonded to the cellulosic sheet and the second layer is bonded to and inseparable from the first layer, wherein there is incorporated into the first layer a sizing agent in an amount of up to 0.6% by weight based on the dry weight of the pigment present in the first layer, the sizing agent is one of the agents specified hereinafter.
We have found unexpectedly and beneficially, that the use of the sizing agent in this manner meets the aforementioned needs. Thus, by use of such an agent in the first layer, the runnability during coating of the second layer may be improved without significantly causing the adhesion between the first and second layers to be adversely affected.
The use of sizing agents in paper making to give water repellency is well known. Generally, these agents are added in conventional processes to provide internal sizing or surface sizing. U.S. Pat. No. 4962072 (Cooper et al) describes the use of sizing reagent in the coating of papers for use in carbonless copy paper sets. The purpose of this use is to cause water soluble adhesive employed in the edge sealing of the sheets to be repellent to the coatings on the sheets whereby the sheets do not stick together except at their edge and may be readily separated. This is opposite to the objective of the method of the present invention in which it is required for the layers to bond together. Thus, it is quite unexpected that an ingredient used to facilitate non-adhesion of sheets in the prior art may be used in the manner of the present invention wherein bonding is required of two coating composition layers, one containing the ingredient concerned.
DESCRIPTION OF THE INVENTION
In the method of the present invention the substrate may comprise a single cellulosic sheet or multiple cellulosic sheets or a cellulosic sheet deposited on a non-cellulosic material in a board, laminate or like structure. The said cellulosic sheet being coated may have already received one or more coating layers, eg. pigment containing compositions, prior to deposition thereon of the first layer. Thus, the said first layer may be layer adjacent to the said cellulosic sheet or a layer intermediate an underlying layer adjacent to the said cellulosic sheet and an outer layer (the said second layer).
In the method according to the present invention the first layer including the sizing reagent is preferably dried to leave the water content of the first layer less than 10% by weight, preferably between 4% and 7% by weight before the said second layer is applied.
In the method according to the present invention the second layer (and any further coating layers deposited thereon) need not contain any sizing agent.
In the method according to the present invention the sizing agent may comprise an alkene ketene dimer, an alkenyl succinic anhydride or an anionic polyurethane.
An alkene ketene dimer (AKD) is preferred as the sizing agent. This may advantageously be employed in amounts of less than 0.26% by weight based on the dry weight of pigment material(s) in the first layer. Desirably, the amount of AKD employed is in the range 0.01% to 0.1% by weight based on the dry weight of pigment present in the first layer.
The alkene ketene dimer may comprise one or more compounds having the formula: ##STR1## where R is an alkyl group having from 8 to 20 carbon atoms.
Coating compositions for use in coating cellulosic sheet materials vary depending upon the materials to be coated which vary throughout the world depending upon the geography of the region in which the material is produced. As noted above, such compositions may vary from layer-to-layer in a multi-layer coated product.
The composition of each layer may include as adhesive or binder, depending on the type of composition concerned, any one or more of the hydrophilic adhesives known or used in the art, eg. selected from starches and other polysaccharides, proteinaceous adhesives, and latices. Starch is generally less expensive and is preferred for use in the first layer or one of the underlying layers.
The amount of adhesive or binder present in the composition of a given coating layer depends upon whether the composition is to be applied as a relatively dilute or concentrated pigment-containing suspension to the material to be coated. For example, a dilute pigment-containing composition (binder-rich composition) could be employed as a topcoat for underlying more pigment-rich compositions. The adhesive or binder present in the composition may range from 1% to 70% by weight relative to the dry weight of pigment (100% by weight) especially 4% to 50% by weight. Where coating composition is not to be employed as a binder rich composition the adhesive or binder may form from 4% to 30%, eg. 8% to 20%, especially 8% to 15% by weight of the solids content of the composition. The amount employed will depend upon the composition and the type of adhesive, which may itself incorporate one or more ingredients. For example, the following adhesive or binder ingredients may be used in the following stated amounts:
(a) Latex: levels range from 4% by weight for self thickening gravure latices to 20% by weight for board coating latices. The latex may comprise for example a styrene butadiene, acrylic latex, vinyl acetate latex, or styrene acrylic copolymers.
(b) Starch and other binders: levels range from 0 to 50% by weight, eg. 4% by weight to 20% by weight for pigment-rich compositions. The starch may comprise material derived from maize, corn and potato. Examples of other binders include casein and polyvinyl alcohol.
Additives in various known classes may, depending upon the type of coating and material to be coated, be included in the coating composition to be concentrated by the method according to the present invention. Examples of such classes of optional additive are as follows:
(a) Cross linkers: eg. in levels 0 to 5% by weight; for example glyoxals, melamine formaldehyde resins, ammonium zirconium carbonates.
(b) Water retention aids: eg. in up to 2% by weight, for example sodium carboxymethyl cellulose, hydroxyethyl cellulose, PVA (polyvinyl acetate), starches, proteins, polyacrylates, gums, alginates, polyacrylamide bentonite and other commercially available products sold for such applications.
(c) Viscosity modifiers or thickeners: eg. in levels up to 2% by weight; for example polyacrylates, emulsion copolymers, dicyanamide, triols, polyoxyethylene ether, urea, sulphated castor oil, polyvinyl pyrrolidone, montmorillonite, CMC (carboxymethyl celluloses), sodium alginate, xanthan gum, sodium silicate, acrylic acid copolymers, HMC (hydroxymethyl celluloses), HEC (hydroxyethyl celluloses) and others.
(d) Lubricity/Calendering aids: eg. in levels up to 2% by weight, for example calcium stearate, ammonium stearate, zinc stearate, wax emulsions, waxes, alkyl ketene dimer, glycols.
(e) Dispersants: eg. in levels up to 2 per cent by weight, for example polyelectrolytes such as polyacrylates (sodium and ammonium), sodium hexametaphosphates, non-ionic polyol, polyphosphoric acid, condensed sodium phosphate, non-ionic surfactants, alkanolamine and other reagents commonly used for this function.
(f) Antifoamers/defoamers: eg. in levels up to 1% by weight, for example blends of surfactants, tributyl phosphate, fatty polyoxyethylene esters plus fatty alcohols, fatty acid soaps, silicone emulsions and other silicone containing compositions, waxes and inorganic particulates in mineral oil, blends of emulsified hydrocarbons and other compounds sold commercially to carry out this function.
(g) Dry or wet pick improvement additives: eg. in levels up to 2% by weight, for example melamine resin, polyethylene emulsions, urea formaldehyde, melamine formaldehyde, polyamide, calcium stearate, styrene maleic anhydride and others.
(h) Dry or wet rub improvement and abrasion resistance additives: eg. in levels up to 2% by weight, for example glyoxal based resins, oxidised polyethylenes, melamine resins, urea formaldehyde, melamine formaldehyde, polyethylene wax, calcium stearate and others.
(i) Gloss-ink hold-out additives: eg. in levels up to 2% by weight, for example oxidised polyethylenes, polyethylene emulsions, waxes, casein, guar gum, CMC, HMC, calcium stearate, ammonium stearate, sodium alginate and others.
(j) Optical brightening agents (OBA) and fluorescent whitening agents (FWA): eg. in levels up to 1% by weight, for example stilbene derivatives.
(k) Dyes: eg. in levels up to 0.5% by weight.
(l) Biocides/spoilage control agents: eg. in levels up to 1% by weight, for example metaborate, sodium dodecylbenene sulphonate, thiocyanate, organosulphur, sodium benzonate and other compounds sold commercially for this function eg. the range of biocide polymers sold by Calgon Corporation.
(m) Levelling and evening aids: eg. in levels up to 2% by weight, for example non-ionic polyol, polyethylene emulsions, fatty acid, esters and alcohol derivatives, alcohol/ethylene oxide, sodium CMC, HEC, alginates, calcium stearate and other compounds sold commercially for this function.
(n) Grease and oil resistance additives: eg. in levels up to 2% by weight, eg. oxidised polyethylenes, latex, SMA (styrene maleic anhydride), polyamide, waxes, alginate, protein, CMC, HMC.
(o) Water resistance additives: eg. in levels up to 2% by weight, eg. oxidised polyethylenes, ketone resin, anionic latex, polyurethane, SMA, glyoxal, melamine resin, urea formaldehyde, melamine formaldehyde, polyamide, glyoxals, stearates and other materials commercially available for this function.
(p) Insolubiliser: eg. in levels up to 2% by weight.
For all of the above additives, the percentages by weight quoted are based on the dry weight of pigment (100%) present in the composition. Where the additive is present in a minimum amount the minimum amount may be 0.01% by weight based on the dry weight of pigment.
The method according to the present invention may be carried out in a known way which will depend upon the material to be coated, the coating composition(s) to be applied and other factors as determined by the operator, eg. speed and ease of runnability eg. using a conventional coating machine.
Methods of coating paper and other sheet materials with one or more coating layers are widely published and well known. For example, there is a review of such methods published in Pulp and Paper International, May 1994, page 18 et seq. Sheets may be coated on the sheet forming machine, ie. "on-machine", or "off-machine" on a coater or coating machine. Use of high solids compositions is desirable in the coating method because it leaves less water to evaporate subsequently. However, as is well known in the art, the solids level should not be so high that high viscosity and levelling problems are introduced.
All known methods of coating for use in the method according to the present invention require (i) a means of applying the coating composition to the material to be coated, viz an applicator; and (ii) a means for ensuring that a correct level of coating composition is applied, viz a metering device.
When an excess of coating composition is applied to the applicator, the metering device is downstream of it. Alternatively, the correct amount of coating composition may be applied to the applicator by the metering device, eg. as a film press. At the points of coating application and metering, the paper web support ranges from a backing roll, eg. via one or two applicators, to nothing (ie: just tension). The time the coating is in contact with the paper before the excess is finally removed is the dwell time--and this may be short, long or variable.
The coating is usually added by a coating head at a coating station. When providing more than one coat, the initial coat (precoat) may as noted above have a cheaper formulation. A coater that is applying a double coating, ie. a coating on each side of the paper, will have two or four coating heads, depending on the number of sides coated by each head. Most coating heads coat only one side at a time, but some roll coaters (eg. film press, gate roll, size press) coat both sides in one pass.
Examples of known coaters which may be employed in step (b) include air knife coaters, blade coaters, rod coaters, bar coaters, multi-head coaters, roll coaters, roll/blade coaters, cast coaters, laboratory coaters, gravure coaters, kiss coaters, liquid application systems, reverse roll coaters and extrusion coaters.
Embodiments of the present invention will now be described by way of example with reference to the following Examples and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 4 of the drawings are graphs that are referred to in the following Examples, which illustrates the invention.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
Example 1
Three coating compositions were prepared for use in providing the first of two coatings applied to a base paper to form a double coated paper. Each composition was prepared according to the general recipe:
______________________________________Ingredient Parts by Weight______________________________________Calcium carbonate pigment 100Adhesive 15______________________________________
The calcium carbonate pigment was a comminuted natural marble which had a particle size distribution such that 60% by weight consisted of particles having an equivalent spherical diameter smaller than 2 μm.
The adhesive used in each of the three compositions was:
A 15 parts by weight of starch
B 12 parts by weight of starch and 3 parts by weight of latex solids
C 10 parts by weight of starch and 5 parts by weight of latex solids
The starch was an oxidised corn starch which is marketed by Cerestar under the trade name "AMISOL 05591". The latex contained 50% by weight of styrene butadiene rubber polymer and is marketed by The Dow Chemical Company under the trade name "DOW 950". The amounts of latex used in the recipes given above are expressed in terms of the weight of dry polymer solids.
Each composition was divided into two portions, 1 and 2. To Portion 1 there was added 0.25 parts by weight, on a dry weight basis, per hundred parts by weight of calcium carbonate pigment, of a weakly cationic alkyl ketene dimer which is marketed by the Hercules Corporation under the trade name "AQUAPEL C519". No alkyl ketene dimer was added to Portion 2.
Each composition was applied to an unsized, absorbent, woodfree base paper by means of a laboratory paper coating machine of the type described in British Patent Specification No. 1032536 at a paper speed of 400 m.min -1 . In each case the coating was dried by blowing air over it for 2 minutes.
Each sample of paper coated with a first coating composition was then coated by means of a laboratory bench blade coating apparatus with a second composition having the general formula:
______________________________________Ingredient Parts by Weight______________________________________Fine calcium carbonate pigment 100Latex adhesive 12Sodium carboxymethyl cellulose 1______________________________________
The fine calcium carbonate pigment was a comminuted natural marble having a particle size distribution such that 95% by weight consisted of particles having an equivalent spherical diameter smaller than 2 μm. The latex adhesive was the same as that used for the first coat, and the sodium carboxymethyl cellulose was that marketed by Metsa Serla under the trade name "FINNFIX 5". Each sample of paper coated with each of the six different first coating compositions was divided into a number of portions and the blade pressure in the coating apparatus was varied to give a series of different weights per unit area of the second composition in the range from 8 to 20 g.m -2 .
The coating apparatus was provided with a device which monitored the rate of drying of the second coating composition by measuring the intensity of light reflected from the surface of the coated paper. The coating immediately after passing beneath the blade was uniformly wet and was therefore highly reflective to light. However, as the coating dried it became duller in appearance. An adjustable light source and a detector were mounted above the coating apparatus to give an incident light beam and a measured beam both at an angle of 75% to the normal to the paper. The signal from the detector was applied by way of a voltage measurement interface to an input of a personal computer. The computer was capable of recording up to 15,000 measurements of light intensity per second, so, in order to provide 150 data points per second, the average of 100 such measurements was calculated to give each data point.
For each sample of paper to be coated, measurements of reflected light intensity were made for about 2 seconds on dry paper. The coating apparatus was then started and a drying curve of light intensity against time was recorded by the computer. A typical drying curve takes the form of an initial drop in light intensity to near zero as the blade passes beneath the source and detector, followed by a rapid increase in intensity as the wet coating film is exposed. The intensity will then begin to decrease as the coating dries and will eventually become constant to give a measure of the reflectance of light from the dry coated paper. For each sample of paper, the rate of drying was expressed as a drying parameter, d. The value of d was determined precisely by plotting the rate of change of light intensity with time and reading as d the time interval between the maximum positive gradient of the light intensity/time curve, when the wet coating is first sensed, and the greatest negative gradient of this curve, when the rate of change of light intensity is at a maximum and the coating is in a partially dried state.
For each of the six first coating compositions a graph was plotted of drying parameter, d, against coat weight and the results are shown in FIGS. 1-3. FIG. 1 gives the results for first coating compositions A1 and A2, with and without the alkyl ketene dimer, respectively; FIG. 2 gives the results for first coating compositions B1 and B2 and FIG. 3 gives the results for first coating compositions C1 and C2.
It will be noted that in every case the drying parameter, d, and hence the drying time, increases with coat weight, but that, for each adhesive system used in the first coating composition, the second coat dries more slowly when the alkyl ketene dimer is added to the first coating composition.
Example 2
Batches of an absorbent woodfree base paper of weight 83 g.m -2 were precoated with four different first coating compositions, each of which was prepared to the general recipe:
______________________________________Ingredient Parts by weight______________________________________Calcium carbonate pigment 100Oxidised starch adhesive 18Sodium hydroxide to pH 8.5Alkyl ketene dimer see belowWater to 62% solids______________________________________
The calcium carbonate pigment was the same as that used in the first coating in Example 1.
The amounts of the alkyl ketene dimer in the four compositions were, respectively, 0, 0.02, 0.05 and 0.1 parts by weight of active alkyl ketene dimer per 100 parts by weight of the pigment. The alkyl ketene dimer was the same as that used in Example 1. The alkyl ketene dimer, when used, was added into the composition after the starch adhesive at a temperature below 40° C.
The first coating composition was applied to the base paper in each case by means of a pilot-scale paper coating machine fitted with a roll applicator and a doctor blade at a web speed of 600 m.min -1 and a blade angle of 49%. The blade pressure was adjusted to give a coat weight of 10 g.m -2 . In order to minimise curl of the paper during the second coating, a first coating was also applied to the reverse side of the paper web at a coat weight of 8.5 g.m -2 .
After the first coating had been applied to each batch of paper, the surface of the coated paper was calendered by passing it through two nips of a supercalender at a line pressure of 50 kN.m -1 at 60° C. and at a speed of 600 m.min -1 .
Each sample of paper coated with a first coating composition was then coated with a second coating composition having the general formula:
______________________________________Ingredient Parts by Weight______________________________________Fine calcium carbonate pigment 100Styrene butadiene latex 12Sodium carboxymethyl cellulose 1Optical brightening agent 0.5______________________________________
The fine calcium carbonate pigment, the latex and the sodium carboxy methyl cellulose were the same as those used in Example 1.
The second coat was applied to each batch of precoated paper by means of a pilot-scale paper coating machine fitted with a roll applicator and a doctor blade. The blade pressure was kept constant at a suitable value which would give a coat weight of the second coating of 9 g.m -2 .
The runnability, or resistance to scratching, of the second coating was investigated by the following procedure:
A second coat was applied first to a batch of base paper which had been precoated with a first coating composition containing no alkyl ketene dimer. The second coating composition was applied at a web speed of 300 m.min -1 was observed, the base paper was changed to a base paper which had been precoated with a first coating composition which contained some alkyl ketene dimer, and a second coat was applied to this paper keeping the second coating composition and the coating machine settings unchanged. If an improvement in the resistance to scratching was observed, the web speed was increased until scratching was observed, or until a web speed of 800 m.min -1 was reached.
The second coating composition was then diluted with water by about 1-2% by weight of solids and coated on to the base paper which had been precoated with a first coating containing no alkyl ketene dimer. The procedure was then repeated until no scratching could be detected during the application of a second coat to the base paper which had been precoated with the first coating which contained no alkyl ketene dimer.
The whole procedure was then repeated using the base papers which had been precoated with the first coatings which contained different amounts of the alkyl ketene dimer.
The results are set forth in Table 1 below:
TABLE 1______________________________________Amount ofalkyl ketene % by weightdimer in first solids in web speedcoat (pph) second coat (m.min.sup.-1) Observations______________________________________0 69.0 300 Frequent scratching0 67.4 300 Slight scratching0 65.7 300 Slight scratching0 63.9 300 No scratching0.02 68.4 300 Slight scratching0.02 66.8 300 No scratching0.02 66.8 800 No scratching0.05 66.6 800 No scratching0.10 68.6 300 No scratching0.10 68.6 600 Scratching reappeared0.10 66.9 600 No scratching______________________________________
Note: "pph" means parts by weight per 100 parts by weight of pigment.
These results show that scratching was most pronounced when a second coating composition was being applied at a high solids concentration (68-69% by weight) on to a base paper which had been precoated with a first coating composition containing no alkyl ketene dimer. The inclusion of only 0.02 parts by weight of alkyl ketene dimer into the first coating composition was sufficient to reduce scratching markedly when a second coating composition was applied at a solids concentration of 68-69% by weight. When a first coating containing 0.1 parts by weight of alkyl ketene dimer was applied, scratching during the application of a second coating composition was completely eliminated under the same conditions.
Example 3
Batches of an absorbent woodfree base paper of weight 94 g.m -2 were precoated with three different first coating compositions having the following recipes:
1. 100 parts by weight calcium carbonate pigment A; 15 parts by weight oxidised corn starch.
2. 100 parts by weight calcium carbonate pigment B; 15 parts by weight oxidised corn starch; 0.6 part by weight sodium salt of styrene-maleic acid copolymer.
3. 100 parts by weight calcium carbonate pigment A; 15 parts by weight oxidised corn starch; 0.25 part by weight alkenyl succinic anhydride.
Calcium carbonate pigment A was the same as that used in the first coating in Example 1.
Calcium carbonate pigment B was a natural marble which was comminuted to a similar particle size distribution as that of calcium carbonate pigment A, but in an aqueous suspension of lower solids concentration and in the absence of a dispersing agent. The oxidised corn starch was the same as that used in Example 1.
The sodium salt of the styrene-maleic acid copolymer was supplied by Atochem under the trade name "SMA 3000".
The alkenyl succinic anhydride was supplied by Claymore Chemicals Limited under the trade name "CLAYSIZE PR4".
In each case the oxidised corn starch was added to the coating composition in the form of a 30% by weight solution which was cooked at 90° C. for 20 minutes before addition.
In the case of compositions 1 and 3, the cooked starch solution was added to an aqueous suspension containing 78% by weight of calcium carbonate pigment A and a sodium polyacrylate dispersing agent. In the case of composition 3, the alkenyl succinic anhydride was mixed in to the composition immediately before coating.
Composition 2 was prepared by mixing 1333 g of a cake containing 75% by weight of the dry calcium carbonate pigment B with 6 g of the sodium salt of the styrene-maleic acid copolymer. A deflocculated suspension of the calcium carbonate pigment at a solids concentration of 74.4% by weight was obtained.
Each first coating composition was applied to the base paper by means of the laboratory paper coating machine described in Example 1 at a paper speed of 400 m.min -1 and a blade angle of 35%. The blade angle was adjusted, if necessary, to give a coat weight of 8.0±0.5 g.m -2 for each first composition. The coatings were dried by infrared heating for 25 seconds with a current of hot air followed by 25 seconds during which cold air was blown over the coated surface.
Each sample of paper coated with a first coating composition was then coated by means of the laboratory bench blade coating apparatus with a second coating composition having the general formula:
______________________________________Ingredient Parts by Weight______________________________________Fine calcium carbonate pigment 100Latex adhesive 12Sodium carboxymethyl cellulose 1______________________________________
The fine calcium carbonate pigment, the latex adhesive and the sodium carboxymethyl cellulose were the same as those used in Example 1. Each sample of paper coated with each of the three different first coating compositions was divided into a number of portions and the blade pressure in the bench coating apparatus was varied to give a series of different weights per unit area of the second coating composition in the range from 8 to 20 g.m -2 . For each first coating composition a graph was drawn of drying parameter, d, against coat weight, and the results are shown in FIG. 4. It will be seen that for the control first coating composition 1 the drying parameter remains virtually constant with second composition coat weight, while in the case of first compositions 2 and 3, in accordance with the invention, the drying parameter increases steeply with second composition coat weight, indicating that the second coat dries more slowly when a sizing reagent is added to the first composition. Example 4
Batches of an absorbent woodfree base paper of weight 83 g.m -2 were precoated with three different first coating compositions, each of which was prepared to the general recipe:
______________________________________Ingredient Parts by weight______________________________________Calcium carbonate pigment 100Oxidised starch adhesive 18Sodium hydroxide to pH 8.5Sizing reagent see belowWater to 62% solids______________________________________
The calcium carbonate pigment was the same as that used in the first coating composition in Example 1.
The sizing reagent was an anionic polyurethane marketed by Eka Nobel under the trade name "CYCLOPAL A" and the amounts used in the three compositions were, respectively, 0, 0.1 and 0.2 parts by weight of active anionic polyurethane per 100 parts by weight of the pigment. The anionic polyurethane was added into the composition before the starch adhesive.
The first coating composition was applied to the base paper in each case by means of a pilot-scale paper coating machine fitted with a roll applicator and a doctor blade at a web speed of 600 m.min -1 and a blade angle of 49°. The blade pressure was adjusted to give a coat weight of 10 g.m -2 . It was not necessary in this case to apply a first coating to the reverse side of the paper web, as the paper coated on one side only was found, after calendering, to have sufficient resistance to curling.
After the first coating had been applied to each batch of paper, the surface of the coated paper was calendered by passing it through two nips of a supercalender at a line pressure of 50 kN.m -1 at 60° C. and at a speed of 600 m.min -1 .
Each sample of paper coated with a first coating composition was then coated with a second coating composition having the general formula:
______________________________________Ingredient Parts by Weight______________________________________Fine calcium carbonate pigment 100Styrene butadiene latex 12Sodium carboxymethyl cellulose 1Optical brightening agent 0.5______________________________________
The fine calcium carbonate pigment, the latex and the sodium carboxy methyl cellulose were the same as those used in Example 1.
The second coat was applied to each batch of precoated paper by means of a pilot-scale paper coating machine fitted with a roll applicator and a doctor blade. The blade pressure was kept constant at a suitable value which would give a coat weight of the second coating of 9 g.m -2 .
The runnability, or resistance to scratching, of the second coating was investigated by the procedure described in Example 2. The results are set forth in Table 2 below:
TABLE 2______________________________________Amount ofpolyurethane % by weightin first solids in web speedcoat (pph) second coat (m.min.sup.-1) Observations______________________________________0 69.2 500 Frequent scratching0 69.2 1000 Frequent scratching0 67.2 500 No scratching0.1 69.0 500 Slight scratching0.1 69.0 1000 No scratching0.2 69.1 300 No scratching0.2 69.1 1000 No scratching______________________________________
These results show that the inclusion of the anionic polyurethane into the first coating composition at a level of 0.1 part by weight per 100 parts by weight of pigment greatly reduces scratching when the second coating composition is applied at a solids concentration of about 69% by weight.
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A method of producing a multiple coated cellulosic sheet product having a surface which is smooth, bright and capable of being printed upon, includes the steps of coating a substrate comprising a cellulosic sheet with a first layer of an inorganic pigment-containing aqueous coating composition, and coating the first layer with a second layer of an inorganic pigment-containing aqueous coating composition to form a product in which the first layer is bonded to the cellulosic sheet and the second layer is bonded to and inseparable from the first layer, wherein there is incorporated into the first layer a sizing agent in an amount of up to 0.6% by weight based on the dry weight of the pigment present in the first layer. The sizing agent is selected from alkene ketene dimers, alkenyl succinic anhydrides, and anionic polyurethane sizes.
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BACKGROUND OF THE INVENTION
In order to determine molecular weight or size distribution of separated particles in GPC (Gel Permeation Chromatography) and HDC (Hydrodynamic Chromatography), peak composition is inferred from its elution volume. Elution volume has been determined in chromatography by measuring the transit time of an unretarded marker species to which the detector is sensitive and ratioing solute position to marker position. Use of a marker is quite typical since even premium quality liquid chromatographic pumps are generally not capable of better than 0.3% flow stability over repeated analyses. For this reason, the practice of assuming constant flow and measuring elution time would frequently result in unacceptable uncertainties in the determination of latex particle diameters as an illustrative example.
Another flow related source of error for concentration-sensitive detectors (UV, IR, RI, Conductivity) in LC is the inverse proportionality between peak area and flow rate, e.g., a 0.5% flow decrease produces a 0.5% area increase.
The most troublesome flow fluctuations are those with periods on the order of peak widths since these cause individual peak areas to change. Such fluctuations can occur, e.g., with reciprocating piston pumps because check valve leakage rates tend to change for subsequent pump strokes, and stroke volumes are typically 50 to 500μl.
Present methods for measuring elapsed flow include collecting a volume of eluant in a graduated cylinder, measuring the movement of a bubble injected into the flowing liquid, or accumulating the total number of dumps of a siphon dump counter, all techniques which can be somewhat imprecise or erratic.
Other classical flow measuring devices, generally for higher ranges, include the following:
1. Coriolis flow meter, measures mass flow as a function of gyroscopic torque forces. This method is complex and expensive; accuracy is ±0.4%.
2. Ultrasonic flow meter, suited for gallons-per-minute flow; accuracy is ±0.5%.
3. D/P flow cell, measures pressure drop across an orifice. Prone to plugging, drift; viscosity dependent.
4. Turbine meter, target meter, venturi meter, rotameter, Pitot tube, all principally applicable to flow rates in excess of 50 cc/min.
5. Continuous heat addition flow meter, heats eluent and measures downstream temperature continuously. Result varies with the specific heat of the metered liquid and ambient temperature fluctuations.
6. Self-heating thermistor, undergoes cooling proportional to flow. Nonlinear and result varies with specific heat of solution and ambient temperature variations.
THE INVENTION
The invention relates to a non-invasive liquid metering method and apparatus for determining liquid movement with an attainable precision of ±0.1% under typical LC conditions. The invention particularly satisfies the technical need for an improved liquid metering method and apparatus for accurately metering liquids in the 0.1 to 10 cc/minute range where metering precision becomes extremely important.
The inventive method and apparatus uses the principle of injecting a heat pulse into the flowing stream via, e.g., a miniature self-heating thermistor (or semiconductor) and detecting the pulse downstream with, e.g., a second microprobe or fast response thermistor. Pulse detection triggers a subsequent heat pulse upstream and the process repeats, with pulse total corresponding to elapsed liquid throughput and pulse frequency to flow rate.
Salient keys to achieving this technical advance in flow metering include particularly:
1. minimizing the thermal mass of the heat "pulser" and sensor through the application of semiconductor pulsing and sensing elements;
2. electronically time-differentiating the sensor output to reject characteristically slower ambient thermal drift and to minimize response time in preparation for subsequent pulse detection;
3. application of a flow metering scheme which uses an improved method for high precision flow measurements and flow cell calibration; and
4. development of a flow cell and method, which by component selection and operation, is highly independent of temperature and liquid composition variables.
While the general principle of heat pulse injection is not entirely new to liquid metering, being applied previously in the form of what is known as "Knauer Electronic Volumeter" distributed through Utopia Instrument Company, Joliet, Ill., none of the recited technical improvements (1-4) are embodied in this prior liquid meter. Among major expressed differences in utility between the invention and the prior meter, as taken from the manufacturer's literature, is the development of a successful two-probe metering flow cell (Knauer teaching utility only with respect to a 4 probe device); as well as the extended utility to meter aqueous solvents, a field of utility disclaimed in the manufacturer's literature.
SUMMARY OF THE INVENTION
The invention as it relates to an electronic flow cell for accurately metering liquid, more specifically comprises in combination:
(a) a flow cell having a flow-through passage;
(b) a resistance heating means comprising a semiconductor element, the resistance heating means having a heat emitting surface which is exposed in the flow passage; and
(c) a heat sensing thermistor, the heat sensing thermistor having a heat sensing surface exposed in the flow passage in fixed, spaced relationship with the heat emitting surface of the resistance heating means.
The invention as it relates to the inventive flow cell, together with the electronic circuit to operate same, comprises in combination:
(a) a flow cell having a flow through passage;
(b) a resistance heating means comprising a semi-conductor heating element, and circuit means to operate the semiconductor element as a resistance pulse heater, the resistance heating means having a heat emitting surface which is exposed in the flow passage;
(c) a heat sensing thermistor, and circuit means to operate the thermistor in the heat sensing mode, the heat sensing thermistor having a heat sensing surface which is exposed in the flow passage in fixed, spaced relationship with the heat emitting surface of the resistance heating means;
(d) a differentiating circuit means for outputting an electrical pulse signal which in magnitude is proportional to dR t /dt, or a time derivative thereof, wherein dR t /dt is the time rate of change of the resistance of the heat sensing thermistor with pulse temperature changes in the liquid to be metered;
(e) said circuit means operating the resistance heating means comprising a timer circuit means which is activated directly or indirectly by each event of a sensible outputted pulse of circuit means (d), to apply a timed voltage pulse to the resistance heating means.
The invention further relates to an improved method for electronically metering the fow of Newtonian liquids which comprises:
(a) conveying the liquid to be metered through an electronic flow cell having a predetermined calibrated cell volume (V c ) and calibrated time constant (K);
(b) inputting uniformly timed heat pulses into the conveyed liquid and detecting the pulses downstream, and wherein each detection event triggers the input of a timed heat pulse to produce the condition of pulse frequency being related to liquid flow rate (f);
(c) electronically detecting the period (T) between pulses; and
(d) determining a measure of flow of the metered liquid based on the application of the relationship,
T=(V.sub.c /f)+K
Optimum forms of the apparatus invention use a self-heating thermistor as the heat pulsing element, in conjunction with a fast response thermistor as the heat sensor, each of which includes an electrical insulator, e.g., of glass, which encapsulates the semiconductor thermistor element thereof. In addition, not less than the second time derivative of the resistance of the heat sensing thermistor is taken and used as the signal to pulse the self-heating thermistor.
In respect to the inventive method, other known forms of electronic flow cells (i.e., "flow cells", the metering principle of which is based on the time of flight of electronically injected heat pulses) can be operated by the method to produce an improved measure of flow. The optimum form of practice of the method invention uses the inventive electronic flow cell. The term Newtonian liquids as used in the method terminology refers to a liquid, the viscosity of which at the metered flow condition is substantially constant.
While the invention has been described with regard to applications where actual data is desired to show, as a measure of flow, instantaneous or averaged flow rate of total flow volume with time, the invention can additionally be applied in the form of a control method or instrument, e.g., to requlate a chromatographic or other liquid metering pump, e.g., by continually detecting flow rate and relaying a signal (measure of flow) to the pump to adjust its flow to a metered setting. It is also apparent that while the major expressed technical need is for improved apparatus and method to meter flow in the sub-10 cc/minute range, the principles of the invention are extendable to measuring a considerably higher range of flow rates as Example 3 demonstrates below.
DRAWING
Yet further features and advantages of the invention will be apparent from the "Detailed Description of the Invention", below, taken with the accompanying drawing wherein:
FIG. 1 is an exploded, partly cross-sectioned view of a preferential flow cell design for metering liquid according to the principles and teachings of this invention;
FIG. 2 is a top view showing the cell body of the FIG. 1 flow cell;
FIG. 3 is a schematic of a preferred electronic circuit for operating the flow cell according to the principles of the method of the invention; and
FIG. 4 is a graph associated with the calibration of the flow cell as described in Example 1.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, a preferred embodiment of the apparatus of the invention is illustrated comprising an electronic flow cell 10 for accurately metering millimeter liquid movement (herein meaning the range of about 0.1 to 10 cc/min). Flow cell 10 comprises a narrow flow-through channel or passage 12 through which the liquid to be metered is flowed. The size or internal volume of the flow cell (calibrated) is fixed and within the range of from between about 0.01 to 0.5 cc, preferably about 0.01 to 0.25 cc.
Mounted fixedly in the body 14 of flow cell 10 is a thermistor 16 (or its equivalent as described hereinafter) which is designed to be used in the self-heating mode to impart brief, sensible heat pulses to the liquid to be metered. The self-heating thermistor is comprised of a heat emitting surface 18 which is exposed to the flow channel for making direct flow contact with the liquid to be metered.
Spaced a fixed distance from the self-heating thermistor is a preferably smaller mass thermistor 20 which, in relative terms, is a fast response thermistor designed for use in the heat sensing mode. The heat sensing thermistor is comprised of a heat sensing surface 22 which is stationary and exposed in flow channel 12, also for making direct flow contact with the liquid to be metered (downstream from the self-heating thermistor).
Preferentially used for the self-heating thermistor is what is referred to as a "standard probe" thermistor, various commercial types of which are described in the trade publication entitled "Thermistor Manual" (Copyright 1974; and also bearing the identifying code number "EMC-6"), this publication being available from Fenwall Electronics, Framingham, Mass., and being incorporated fully herein by reference.
These standard probe thermistors are characteristically available in the desirable form comprising a glass bulb or probe, given Reference Numeral 24 in the drawing, and which comprises the heat emitting surface of the thermistor. Encased in the glass probe is a semiconductor element 26 which is thus protected and electrically insulated from direct contact with the liquid to be metered. The glass encased semiconductor element or probe 24 of this preferential thermistor type measures 0.100" in diameter. It can be used to develop approximately 50-150 milliwatts peak power over extended use periods without apparent deterioration or alteration of its electrical properties. Its small thermal mass, indicated by its Time Constant rating (T.C.) in air of between about 14-22 seconds is found generally sufficient to permit rapid enough pulsing in liquid to be suited for application to the invention; and its power output sufficient to develop sensible heat pulses in conjunction with the heat sensing capability of thermistor 20.
Preferentially selected as the heat sensing thermistor 20 is what Fenwall refers to as its "fast response" glass probe thermistor, also comprised of a semiconductor element 28 encased in a glass bulb or probe 30. These thermistors, due to a much smaller thermal mass, have a T.C. rating in air of about 5 seconds or less.
The commercial heat sensing thermistors described generally have a 3-4 percent/°C. negative temperature coefficient. This range of sensitivity has been found quite suitable for use in the invention. A lesser temperature coefficient for the heat sensing thermistor would be operable so long as sufficient resistance change is registered to sense the heat pulses in the liquid.
As should be readily apparent, the temperature coefficient of the self-heating thermistor is largely an unimportant parameter since this thermistor is used in the self-heating mode; it being preferred, however, to use a self-heating thermistor with a negative temperature coefficient to minimize possible thermistor damage due to inadvertent excessive heating, e.g., in the event the apparatus is abused or operated improperly. Either a negative or positive temperature coefficient thermistor may be equivalently used as the heat sensing thermistor.
As mentioned previously, the invention contemplates equivalents to the self-heating thermistor. These would be based on the substitution for thermistor element 16, of a semiconductor based heating element which differs in that it does not possess the temperature coefficient property which characterizes a thermistor element. The term "semiconductor" is intended to define a material which has a resistivity in the range of about 10 3 to 10 13 μohm-centimeters, most preferably, about 10 4 to 10 6 μohm-centimeters. Marginally useful as element 26 are resistance heating elements, the resistivity of which falls within the transition range between conductors and semiconductors, i.e., from about 750-1000μohm-centimeters. The term "semiconductors", as used in this disclosure, is by definition intended to include such latter materials having a resistivity within the defined transition range (e.g., certain carbon based materials); and which may be suitably fabricated into resistance heating elements useful for the purposes of the invention.
CELL FABRICATION
As can be readily appreciated, a very advantageous feature of flow cell 10 is its simplicity in design and fabrication. A preferred flow cell is constructed using a machinable block of glass filled Teflon® to fabricate cell body 14. Ordinary drilling methods may be used to define flow channel 12. In addition, threaded openings 32, 34 are tapped at each end of the cell body for attaching chromatographic tube end fittings 36, 38 for passing liquid to be metered through flow channel 12; and similar threaded openings 40, 42 are tapped in the cell body at positions normal to the flow channel for threadably mounting the thermistors 16, 20, respectively.
Due to the relatively large size of the self-heating thermistor, a small depression 44 is sunk in cell body 14 immediately below the lower tip of heat emitting surface 18. The depression permits the heat emitting surface of the self-heating thermistor to be adjustably moved for centering on the axis of flow channel 12 for alignment with heat sensing surface 22 of the heat sensing thermistor (which is similarly desirably centered on the axis of the flow channel). Where relative dimensions require, the flow channel can be enlarged at the position of either or both thermistors 16, 20 to produce a coaxial step enlarged cavity in which the heat emitting and heat sensing surfaces of the thermistors are placed in centering alignment with the axis of the flow channel. The flow channel between the thermistors is correspondingly relatively small in diameter, to produce a flow cell of correspondingly small (calibrated) volume. The small size flow cells are also beneficially fabricated by mounting thermistors 16, 20 on opposite sides of cell body 14 whereby, through the offset, a closer spacing and thus shorter flow channel length dimension can be defined using essentially the same flow cell design as illustrated in the drawing.
A preferred arrangement for threadably affixing thermistors 16, 20 in cell body 10 employs hollow threaded plugs 46, 48, preferably of plastic, through which the electrical lead wires of the thermistors 16, 20 are passed. Elastic O-rings 50, 52, suitably of Kalrez®, are seated in threaded openings 40, 42, respectively, and compressed to form a liquid tight seal about the glass thermistor body of each thermistor. A terminal strip 54 is attached, e.g., by machine screws, to the cell body. The lead wires of the thermistors are fastened, e.g., by standard electrical contact screws, to the terminal strip.
Obviously, considerable variation in this simple cell design is possible without changing it functionally. For example, the cell body may be composed of several joined components (as opposed to the unitary block construction shown). In addition, the cell flow channel may be defined using, e.g., a narrow diameter plastic tube (an embodiment described in the teaching Example 3, below).
FLOW RESTRICTOR
A flow restrictor or restrictor means 56 is connected by chromatographic tube end fitting 38 to the outfeed port or opening 34 of flow cell 10. The flow restrictor suitably comprises an appropriate length of capillary tubing which restricts flow to produce back pressure sufficient to avoid minute degassing of the metered liquid. The flow restrictor is beneficially used whenever the flow cell is located in a position of insufficient back pressure to avoid detrimental degassing phenomena. Any alternative device such as a common restrictor valve may be equivalently substituted for the illustrated capillary tube. The use of the flow restrictor, while optional, produces optimum levels of liquid metering precision in combination with flow cell 10 when used, e.g., to monitor chromatographic column effluent flow (where characteristically low back pressure leads to detrimental degassing of the metered liquid).
ELECTRONICS
A preferred design of an electronic circuit for operating flow cell 10 is shown in FIG. 3 and comprises circuit means 58 for operating thermistor 20 in the heat sensing mode. Circuit means 58 comprises a standard voltage divider circuit consisting of a potentiometer 60 and a series resistor 62 divided at juncture A from thermistor 30 and series resistors 64, 65. The total resistance of the circuit is sufficient to produce negligible current pulse surges due to pulse resistance decreases of the thermistor, and hence, non-detrimental self-heating of the heat sensing thermistor. The terminals of a common power source are connected across the voltage divider circuit to provide energizing voltage within the equilibrium range of thermistor 20. A capacitor 67 stabilizes the voltage at juncture A from rapid transients in the positive voltage supply level.
Pulse temperature changes in the metered liquid are electronically sensed in the form of positive-going voltage pulses which are proportional to the resistance change of thermistor 20 with temperature (this circuit being designed for and assuming the use of a negative temperature coefficient heat sensing thermistor). The outputted voltage pulses pass through a series current limiting resistor 66 and are amplified by a non-inverting, e.g., conventional type 741, operational amplifier 68, set for a gain of 50 by the selected ratio of resistors 70, 72 which are set in a voltage divider circuit mode on the negative feedback of amplifier 68 (in the standard arrangement). An approximate pulse wave form of the pre-amplified and amplified voltage pulse is shown in Inset A-B. This pulse is fed to a preferably two stage differentiating amplifier circuit or circuit means 74, 74a. First stage 74 of the differentiating circuit comprises a capacitor 76 in series with a current limiting resistor 78 and connected to the inverting input of, e.g., preferentially a type 741, operational amplifier 80. A feedback resistor 82 returns the input to zero following each inputted pulse signal. A capacitor 84 is connected in parallel with resistor 82 to filter high frequency ambient electrical noise.
The outputted pulse signal of amplifier 80 is both inverted and proportional to the time rate of change of the inputted voltage pulse (of Inset A-B), an approximated wave form of the outputted and derivatized pulse being shown in Inset C. Since the amplified Inset A-B voltage pulse is proportional to the electrically sensed resistance of the heat sensing thermistor, the outputted pulse (Inset C) is thus equivalently considered as the amplified time rate of change (or first time derivative) of the resistance change of thermistor 20 with pulse temperature changes in the metered liquid.
The time rate of change pulse signal is inputted to the second stage 74a of the differentiating circuit, which consists of the common elements (with amplifier 80) given like reference numerals. Additionally, the non-inverting input of the second stage amplifier 80a is provided with a zero adjustment biasing circuit 84 which is connected to the referenced power supply outputs in order to trim output of the voltage pulse signal of amplifier 80a. An approximate form of the amplifier 80a, pulse signal is shown for exemplary purposes in Inset D; and is the amplified, electronically derived, second time derivative of the resistance of the heat sensing thermistor 20 with pulse temperature changes in the metered liquid.
The second derivative voltage pulse is fed through a current limiting resistor 86 to the non-inverting input of, e.g., suitably a type 741 operational amplifier 88. Amplifier 88 is connected to a capacitor 90 and resistors 92, 94 to produce high gain amplification with additional high frequency filtering. An outputted voltage pulse amplified, e.g., 500 times, is generated by amplifier 88 and filtered through a low pass filter consisting of a resistor 96 and capacitor 98 connected to the power supply common. The total amplification and derivatization functions produce a square wave curve or voltage pulse form which is shown in Inset E.
The voltage pulse of Inset E is fed to a timer circuit means 100 for pulsing the self-heating thermistor, and which includes a current limiting resistor 102, connected to the base of a switching transistor 104, suitably a standardized Part No. 2N3904. Transistor 104 switches its collector terminal 106 from +15 volts (power supply level) to zero upon arrival of the output of each Inset E voltage pulse. With each such triggering of the collector terminal, a voltage pulse from +15 to zero is produced.
The collector terminal at rest is biased at +15 volts by a voltage divider circuit consisting of a resistor 108 and the switching transistor. A second voltage divider 110, 112 produces a highly positive voltage at rest. The two voltages are placed across a capacitor 114 such that the capacitor is at an elevated voltage on both plates. The switching of the collector terminal voltage rapidly reduces the voltage at capacitor 114, whereby capacitor plate 116 is pulled to zero briefly until the second voltage divider returns to the rest voltage. Consequently, the voltage pulse width generated at the collector terminal is reduced to a voltage spike, which is fed to pin #2 of, e.g., suitably a type 555 timer 118. Pin 190 2 of the timer is the time cycle reset pin. The timer outputs a voltage pulse at pin #3, the duration of which is determined by an external variable resistor 120 in combination with an external capacitor 122 connected to pins #6 and #7 of timer 118. The setting is adjustably changed in this circuit between the limits of 0.1 to 1.0 second. Pins #1 and #2 are connected to common and the +15 volts power supply, respectively.
An outputted voltage of fixed duration is fed from pin #3 to a relay 124, e.g., suitable a DIP reed relay, which is a double pole, single throw relay which completes the contact between the power supply, a series resistor 126, and the heating thermistor 16. Leads 128, 130 connect from the relay to an external data collector 132, e.g., a computer, which records each activation event of the self-heating thermistor (in order to derive T). The circuit is initially activated by a manual switch 134. A single 100 ma-rated ±15 volts regulated power supply may be used to operate the entire circuit.
OPERATION
The liquid metering process is initiated by pushbutton activation of a thermal pulse at R h (the self-heating thermistor). The -4%/°C. temperature coefficient of the referenced Fenwall type GB38P12 heat sensing thermistor (R t ) produces a positive-going voltage at juncture A as the warm liquid pulse traverses the sensing zone. This signal is amplified at B and connected through capacitor 76 to the inverting input of amplifier 80 of the first stage differential amplifying circuit 74. This arrangement yields a pulse voltage output at C equivalent to the amplified inverted time derivative at B. Output at C is proportional to dR t /dt and thus slow temperature changes yield essentially zero response in contrast to heat pulses generated in situ by the self-heating thermistor.
A single derivative pulse output returns to baseline too slowly to be optimally prepared for subsequent pulses. Most preferably, therefore, an inverted second derivative is produced at the second stage amplifier 80a resulting in the approximate pulse output form shown in Inset D and which is proportional to d 2 R t /dt 2 .
This voltage pulse form is amplified at E to drive the transistor triggered timing circuit that applies power to the reed relay. This relay supplies a +30 volt D.C. pulse for a fixed time interval (generally 0.1 to 1.0 second) to both the pulse counter (i.e., computer), and self-heating thermistor 16. Metering precision is improved through the use of a D.C. pulse form, as opposed to an A.C. voltage pulse to heat thermistor 16. The 2K ohm resistor 126 protects the self-heating thermistor from overheating damage as it tails into self-heating and reduced resistance. A calculated maximum of 113 mW of power is dissipated at R h during application of the +30 volts D.C. power, using the referenced Fenwall GB34P2 standard probe thermistor.
The rate of flow and/or total flow of the metered liquid is electronically computed based on the pulse data collected by the electronics, and by applying the following generic mathematical expression:
T=V.sub.c /f+K
where:
T=time period between pulses (e.g., in seconds);
V c =calibrated cell volume constant (e.g., in cubic centimeters);
f=flow rate (e.g., in cubic centimeters per second); and
K=calibrated time constant (e.g., in seconds).
The values V c and K may be determined, e.g., by the exemplary flow cell calibration procedure described in Example 1. T is the pulse period data collected, whereas f is solved to derive the flow rate of the metered liquid. Since the value V c /f is shown to be characteristically linear with T over a wide flow rate range (see Example 1), the computation of f may be straightforwardly performed electronically; and by a chart recorder or other device displayed visually in any desired form, e.g., to display either or both the instantaneous or averaged flow rate, or to produce based on total pulse count (ΣT), total flow of the metered liquid over any elapsed period of time.
EXAMPLE 1
Calibration
This Example describes a preferential calibration method suitable to determine the calibration constants V c and K. These constants are described with respect to a given flow cell, electronic circuit, and electronic settings. In this study, the flow cell is of a design in which the thermistors 16, 20 are set apart (in center-to-center spacing) approxmately 11/2 inches; and are used in conjunction with a flow channel 12 of approximately 1/16 inch in diameter. Timer 118 is set to produce 0.8 second pulse heating time; and potentiometer 60 is adjusted to provide a steady state 50 mV positive baseline voltage on which the positive-going voltage pulses of the heat sensing thermistor are imposed. The zero adjust biasing circuit 84 is adjusted to produce zero voltage at D during the absence of pulsing.
Apparatus used to calibrate the flow cell consists of a Constametric I pump from LDC Corporation. The pump withdraws liquid (water) from a chromatographic reservoir, and advances it at a preset rate of flow through, sequentially, a pressure gauge, pulse dampening coil, and ultimately the flow cell, using standard 1/16 inch O.D. chromatographic tubing to convey the liquid. The discharge from the flow cell is fed through a back pressure-applying capillary coil (3"×0.005" I.D. capillary) to a collection vessel. A timer is used with a high precision balance to verify liquid flow rates.
The data generated are compiled in Table I, below, wherein: f is the averaged flow rate in cc/minute determined from the precision balance and timer; and T is the averaged time period in seconds between pulsing of the self-heating thermistor as determined from relay 124.
TABLE I______________________________________Experiment f l/f TRun Number cc/min (seconds/cc) (seconds)______________________________________1 5.30 11.321 1.18262 4.78 12.552 1.23843 4.25 14.118 1.30784 3.74 16.043 1.39875 3.20 18.750 1.52406 2.64 22.727 1.70207 2.125 28.235 1.97298 1.61 37.267 2.43279 1.06 56.604 3.3449______________________________________
Knowing f and T from any two sets of data points, taken from Table I, the equation T=V c /f+K can be solved to yield the calibration constants V c and K, using simultaneous equation solving methods to determine the two unknowns. For the given flow metering system described, and using the Table I data, the calibrated cell volume V c is computed to be 0.048 cc; and the calibration constant K is computed to be 0.630 second. Hence, flow in cc/second is determined according to this flow cell, using the expression
T.sub.sec =0.048 cc/f+0.630 sec.
The validity of the above equation is further established by making the plot illustrated as FIG. 4. The data points of multiple solutions to the equation at varying T sec and f cc/min produce the straight line (slope of V c ) which is projected to intercept the ordinate axis at the value K. Thus, the equation shows that the linear y=mx+b relationship is closely followed. The correlation coefficient for this data is calculated to be 0.99989.
Use of the mathematical basis described above to calibrate the flow cell constants produces exceptional liquid metering precision as shown in Example 2. Nevertheless, liquid flow may be alternatively measured using the flow cell with conventional calibration methods, e.g., by equating total pulse count and pulse frequency data, taken from relay 124, to preknown accumulated liquid volumes or flow rates, as applies. These latter calibration methods can be applied, for example, in order to use the flow cell for metering accurately non-Newtonian fluids.
EXAMPLE 2
Precision
The precision of an electronic flow cell of the same design as used in Example 1 is studied by connecting the cell to an elevated eluent reservoir through 5 feet of standard wall 1/16 inch O.D. chromatographic tubing. Liquid (water) is fed by gravity feed through the flow cell under a hydrostatic head pressure (total) of 6 inches of water. The water is dispelled ultimately to a collection vessel through tubing (also 1/16" O.D.) which has its end immersed in water in the collection vessel. Initial liquid flow is at approximately 1 cc/minute, and diminishes very slightly during the course of the experiment.
The time value of each pulse T produced at relay 124 is electronically stored in the memory bank of a MINC LSI-11 Microcomputer. At the completion of data collection, the computer electronically generates a linear regression curve and computes the standard deviation of T to be 2.973 milliseconds. Precision is calculated from the observed standard deviation to be 0.092% at the 63% confidence level (±1 sigma).
Since it is assumed that actual flow varied randomly (in very small amounts), due solely to the imperfect characteristics of the testing apparatus, observed precision is thus determined to be no worse than 0.092% in this experiment and quite likely true precision is better.
EXAMPLE 3
Range
The various flow cells used in this study essentially differ only in respect to calibrated cell volume (V c ). Flow cells Nos. 1 and 2 of Table II, below, are constructed using 24 and 12 inches, respectively, of 0.031 inch I.D. tubing which is connected between flow cell blocks each singularly mounting a thermistor. These are the relatively large volume cells. Cells Nos. 3 and 4 are smaller volume cells of the design shown in FIGS. 1 and 2; flow cell No. 3 being that used in the preceding Example 1. A variable liquid chromatographic metering pump is used to determine the dynamic flow range specific to each cell design, the observed results being reported in Table II.
TABLE II______________________________________ Observed T Average InFlow Calculated Seconds @Cell K V.sub.c /V.sub.g * Flow Range Flow RangeNo. in seconds in cc in cc/min Limits______________________________________1 0.687 0.492/0.424 9.84+ 3.69 @ flow minimum2 0.689 0.219/0.225 4.56- 11.0 3.63- 1.883 0.630 0.048/0.075 1.05- 5.30 3.34- 1.184 0.653 0.017/0.025 0.20- 2.17 5.72- 1.12______________________________________ *V.sub.g = geometric cell volume
The largest volume cell No. 1 shows a threshold (minimum) flow detection limit at about 10 cc/minute, its upper limit not being tested due to the limitations of the pumping apparatus used in the experiment. This flow cell demonstrates the feasibility of extending the liquid flow metering principles of the invention to the metering of considerably greater than 10 cc/minute flow rates.
Flow cells Nos. 1--3 collectively demonstrate the utility of the invention for metering liquid across essentially the entire practical scope of the sub-10 cc/minute flow range. This experiment is not intended to be construed to represent an optimization study of flow cell dynamic operating range as to any given cell design used in the experiment.
A point to be noted is that the K values determined for the various flow cells 1-4 are not identical. The slight discrepancies between the observed K values can probably be attributed to small differences in the electrical characteristics of the thermistors 16, 20 of each flow cell which, while of identical manufacturing source and part description, would be expected to vary slightly in thermal mass and/or electrical properties.
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Apparatus for accurately metering liquid flow based on the injection of a brief heat pulse into the flowing stream, e.g., via a miniature thermistor, and detection of an electronic time derivative of temperature downstream with, e.g., a second microprobe thermistor. This detection triggers a subsequent heat pulse and the cycle repeats, wth pulse total corresponding to elapsed liquid throughput, and pulse frequency to flow rate.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to structural building blocks, and to modular systems for constructing composite structures, such as walls and edging which are usable in landscaping. More particularly, the invention relates to an improved structural building block, and to composite structures constructed therewith.
2. Background Art
Several types of modular landscaping systems are known and in common use today for constructing retaining walls, edging and other landscaping structures. Common landscaping systems include wood timbers and concrete-like blocks.
Examples of some of the known landscaping timbers, structural building blocks, and related devices include U.S. design Pat. No. D371,446 to VanDeusen, U.S. design Pat. No. D386,652 to Rimback et al., U.S. design Pat. No. D438,992 to Chrisco et al., U.S. design Pat. No. D448,859 to Doman, U.S. Pat. No. 5,168,678 to Scott, Jr. et al., and U.S. Pat. No. 6,062,772 to Perkins.
Although the known landscaping timbers and structural building blocks are usable for their intended purposes, a need still exists in the art for an improved structural building block and modular system, which is usable to build landscaping retaining walls. In particular, there is a need for an improved structural building block which is combinable in a staggered configuration, to build an internally reinforced wall.
SUMMARY OF TIE INVENTION
The present invention provides a structural building block, which is usable to build a retaining wall, or to make edging for a landscaped outdoor area. A block according to the invention may be interconnectably combined with a plurality of similar blocks, and with fasteners, to build a wall structure. A building block according to a specific embodiment of the invention is constructed and arranged so that any one of a variety of different wall configurations may be made, according to the needs of a particular user. Blocks according to a particular embodiment of the invention may be combined in a staggered configuration, to build a relatively strong, internally reinforced wall. The blocks according to the invention may also be used to form edging at the perimeter of a landscaped outdoor area.
A building block according to a first embodiment of the invention includes a block body having front and rear faces, top and bottom surfaces, and first and second ends. The first end of the block has a plurality of spaced-apart fingers extending longitudinally outwardly thereon, substantially parallel to a longitudinal axis of the block. The second end of the block also has a plurality of spaced-apart fingers thereon. The fingers on the second end of the block are oriented and spaced to be alignable with empty spaces between other fingers on the first end of a second, substantially similar block, allowing adjacent similar blocks to nestingly interengage.
The fingers have side surfaces which are coextensive with, and substantially flush with the front and rear faces of the block. The tip ends of the fingers are radiused, so that the outside corner edges thereof are rounded off.
The uppermost finger on the first end has an upper surface which is substantially flush with the block top surface. Optionally, the upper surface of the uppermost finger may have a recess formed therein to accept a fastener head, allowing the fastener head to be situated at or below the level of the finger's upper surface.
As noted, the second end of the block also includes a plurality of spaced-apart fingers extending longitudinally outwardly thereon. The fingers of the second end are placed on the block body so as to line up vertically with spaces between the fingers of the first end.
The lowermost finger on the second end has a lower surface coextensive with, and substantially flush with the block bottom surface. Optionally, the lower surface of the lowermost finger may also have a recess formed therein to accept a fastener head.
The fingers of the respective first and second ends have through holes formed therethrough, with the through holes of each end coaxially aligned with one another. Each of the through holes has an axis which is substantially perpendicular to a longitudinal axis of the block.
It is an object of the present invention to provide a building block, and a modular system incorporating such building block, which can be used to construct a landscaping wall.
It is a further object to provide a building block and modular system which provides the ability to construct curved walls.
For a more complete understanding of the present invention, the reader is referred to the following detailed description section, which should be read in conjunction with the accompanying drawings. Throughout the following detailed description and in the drawings, like numbers refer to like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a top plan view of a first structural block in accordance with a first embodiment of the invention;
FIG. 1B is a side plan view of the block of FIG. 1 ;
FIG. 2 is an exploded perspective view of two adjacent blocks and a connector according to the first embodiment;
FIG. 3 is a perspective view of a first wall section built using a plurality of blocks according to the first embodiment hereof;
FIG. 4 is an expanded view of the wall section of FIG. 3 , showing how the blocks can be used to form a curved wall;
FIG. 5A is a perspective view of a supplemental block which can be used in conjunction with the block of FIGS. 1A-1B as part of a system;
FIG. 5B is a top plan view of the block of FIG. 5A ;
FIG. 5C is a front plan view of the block of FIGS. 5A-5B ;
FIG. 6 is a perspective view of a second wall section built using a plurality of blocks according to a second embodiment hereof, using the base blocks of FIGS. 1-2 in combination with a plurality of the supplemental blocks of FIG. 5 ;
FIG. 7 is an expanded view of the wall section of FIG. 6 , showing how the blocks can be used to form a curved wall;
FIG. 8 is a perspective view of a finishing block which is usable with a system according to the present invention;
FIG. 9 is a perspective view of a series of interconnected blocks including the finishing block of FIG. 8 ;
FIG. 10 is an exploded perspective view of a connecting block insert and a hollow landscape timber according to a third embodiment of the invention; and
FIG. 11 is a top plan view of the insert and landscaping timber of FIG. 10 .
DETAILED DESCRIPTION
First Embodiment
Referring to FIG. 1 , there is shown a structural base block 10 according to a first embodiment of the invention. The block 10 includes a substantially rectangular central block body 11 having a front face 12 , a back face 14 , a top surface 16 , a bottom surface 18 , a first end 20 , and a second end 32 opposite the first end. It will be understood that the block 10 may be made in any practical and appropriate length, such as, e.g., two feet, four feet, six feet, or other desired length.
The block 10 may be formed of wood, plastic, cement, or other known material. Where wood is used, treated wood, which is resistant to decay is preferred. Where plastic is used, the blocks may be hollow.
Throughout the present specification, relative positional terms like ‘upper’, ‘lower’, ‘top’, ‘bottom’, ‘horizontal’, ‘vertical’, and the like are used to refer to the orientation of the block 10 as shown in the drawings, particularly FIG. 1 B. These terms are used in an illustrative sense to describe the depicted embodiments, and are not meant to limit the scope or application of the invention. It will be understood that the depicted block 10 may be placed at an orientation different from that shown in the drawings, such as inverted 180 degrees or oriented transversely to the orientation shown, and in such a case, the above-identified relative positional terms will no longer be accurate.
In the base block 10 of FIG. 1 , the first end 20 includes first and second fingers 24 , 26 integrally formed with, and extending outwardly from the central block body 11 . The first or uppermost finger 24 includes an upper surface 25 , which is coextensive with, and flush with the top surface 16 of the block. The second finger 26 is located directly below the first finger 24 and is spaced away therefrom, thereby forming a gap 28 between the first and second fingers. The second finger 26 is substantially the same size as the first finger 24 . Optionally, the height of each of the fingers 24 , 26 may be approximately one fourth of the height of the block body 11 , as shown in the drawing. A second gap 30 is provided directly below the lower second finger 26 . The height of each of the gaps 28 , 30 is just slightly larger than the height of one of the fingers 24 or 26 .
As seen in the top view of FIG. 1A , the outer corners, at the tip ends of each of the first and second fingers 24 , 26 are chamfered, or rounded off at the edges thereof. This may also be described as radiused, because the straight-line horizontal distance (radius) from the vertical center line of the hollow bore 42 in the fingers to any point on the outer surface of the finger tip should be approximately a constant value.
The second end 32 of the block 10 is substantially identical to the first end 20 , if the block of FIG. 1B was rotated 180 degrees clockwise around the center point thereof. The second end 32 includes third and fourth fingers 34 , 36 , which are the same size as the first and second fingers 24 , 26 . The third, or lowermost finger 34 includes a lower surface 35 which is coextensive with, and flush with the block bottom surface 18 . The fourth finger 36 is located directly above the third finger 34 and spaced upwardly away therefrom, thereby forming a gap 38 between the third finger 34 and the fourth finger 36 . Another gap 40 is located directly above the fourth finger 36 . These gaps 38 , 40 are slightly larger than the vertical height of one of the fingers.
The tip portions of the fingers 34 , 36 are radiused, as previously discussed, and also have coaxially located through-holes 42 formed therein.
It will be seen from FIG. 1B that the gap 28 , between the first and second fingers 24 , 26 , is vertically aligned with the fourth finger 36 on the opposite side of the block 10 , and the gap 30 , below the second finger 26 , is vertically aligned with the third finger 34 . The respective fingers and gaps are dimensioned to allow the second end of a first block 10 a ( FIG. 2 ) to nestingly interengage with the first end of a second, identical block 10 b , with the top and bottom surfaces of the respective blocks being substantially aligned.
Optionally, the lower surface 35 of the third finger 34 may have recesses 44 formed therein (FIG. 1 B), to accept the head of a fastener 70 , thereby making the fastener flush with the respective top or bottom surface of the block. In this way, blocks having fasteners installed therein may be vertically stacked on top of one another, if desired, without the fasteners creating unwanted space therebetween. Formation of a recess in the third finger 34 makes the first and second ends 20 , 32 , identical and interchangeable, so that the block is never upside down.
FIG. 2 shows an exploded perspective view of two blocks 10 a , 10 b and a fastener 70 for interconnecting the blocks.
The first block 10 a and second, substantially identical block 10 b are joined together when the third and fourth fingers 34 and 36 of the first block nestingly engage into the gaps 28 , 30 next to the fingers 24 and 26 of the second block. With the fingers nested together and the holes 42 aligned with one another, a fastener 70 is then pushed through the holes, thereby pivotally joining the blocks together.
The fastener 70 includes a substantially straight and cylindrical shaft 72 , and an enlarged head 74 attached to an end of the shaft. The exact shape of the fastener head 74 is not critical. Where a recess 44 is used to receive the fastener head 74 , the recess should be formed in a shape corresponding to the shape of the fastener head.
Since the ends of the fingers are radiused, as discussed above, the blocks 10 a , 10 b can be pivotally moved relative to one another around the fastener 70 , to any desired angular relation up to 90 degrees, until the blocks contact and interfere with one another. In the larger view, this permits the formation of curved walls such as that shown in FIG. 4 .
Optionally, the blocks 10 according to the invention may be formed from a single beam of wood or other starting material, and may be cut out using a laser beam, in an inert gas atmosphere. Nitrogen gas may be used. A five kilowatt laser may be required for this process. Such a method of making the blocks makes a very efficient use of the material, and produces blocks having darkened, carburized surfaces where the cuts have been made.
Wall Construction
Aligning a multiplicity of blocks 10 in a manner as described, and connecting the blocks with fasteners 10 , a user can build a landscaping retaining wall in any desired shape that the pivotally movable blocks 10 can be placed into.
A first example of a wall 100 built with a multiplicity of blocks 10 , according to the first embodiment of the invention, is shown in FIG. 3 . In the wall of FIG. 3 , all of the blocks 10 in a given row are lined up end-to-end with coplanar top surfaces and coplanar bottom surfaces.
A plurality of structural blocks 10 a - 10 f can be joined together to form a wall 100 as illustrated in FIG. 3 . Each row of blocks is assembled in a manner such that the fingers of each block nest with the corresponding fingers of an adjacent block, with the upper surfaces 16 of the adjacent blocks in horizontal alignment with one another, thereby creating distinct, vertically stacked rows of blocks.
While two rows of blocks are shown in FIG. 3 , it will be understood that three, four or more rows may be used, as appropriate for a particular installation.
The blocks 10 are fastened together and to the substrate 120 with fasteners 70 , such that the fasteners pass through the through holes 42 and into the substrate, thereby joining the blocks together and securing the wall structure to the substrate, which may be ground. The head 74 of each fastener 70 fits into the recess 44 at the top of the finger through-holes 42 , thereby making the fastener head flush with the surface of the respective block.
If desired, some of the fasteners can be made extra long, or else can be installed so that they extend down into the cement or other substrate that the wall 100 is being built on.
Alternatively, in the wall design of FIG. 3 , where appropriate, a single, long fastener 70 may be used, for each connection point between adjacent blocks, to extend downwardly through all of the rows of blocks. The use of a single, long fastener 70 at each connection point also serves to join the vertical rows together. This long fastener may further extend through the blocks and into the substrate 120 to anchor the wall in place.
A larger three-dimensional view of the wall 100 , showing curvature on part of the wall caused by pivotally moving selected blocks relative to one another, is shown in FIG. 4 . Once such a wall is built, and placed into the preferred orientation thereof, dirt may be filled in behind the wall to provide a terraced effect.
As previously noted, blocks 10 of different lengths can be made, and optionally, in the practice of the present invention, different length blocks could be combined with one another. This allows for an overall shape of a landscaped area that is flat, rounded or and/or curved in different sections thereof, according to the requirements of a particular user. The shape of the landscaped area can be customized to fit the available space for a particular application.
Supplemental Short Block
FIG. 5 illustrates a supplemental short block 210 according to a second embodiment of the invention. The short block 210 is provided for use in combination with the base block 10 , to build a reinforced wall 200 (FIG. 6 ), in which the base blocks 10 are arranged in a vertically staggered configuration.
The short block 210 resembles one of the base blocks 10 which has been cut in half along a horizontal center plane thereof and had one of the resulting pieces removed.
The short block 210 includes a rectangular block body 211 having front and back faces 212 , 214 , top and bottom surfaces 216 , 218 and first and second ends 220 , 222 . The first end 220 of the block 210 has a single, upper finger 224 extending outwardly thereon above a gap 230 . The second end 222 of the block 210 has a single, lower finger 226 extending outwardly thereon below a gap 232 . Each finger has a through-hole 238 formed therein and an enlarged recess 240 for accepting a fastener head.
Alternate Wall Construction
FIGS. 6-7 illustrate a wall which can be constructed using both the base blocks 10 and the short blocks 210 . If the base blocks 10 are alternated with the short blocks 210 in a first row of a wall, a base row having a staggered upper profile is achieved. Wherever short blocks 210 (such as that shown at 200 a ) are found in the lower row, a base block 10 is set on top of each short block 210 , with yet another short block 210 (such as that shown at 200 b ) stacked thereon, as shown (for a wall of the height illustrated).
In this way, a reinforced wall construction 200 is realized in which the base blocks 10 are vertically staggered relative to one another. Fasteners 70 are used in a manner similar to that used in constructing the wall 100 of FIG. 3 .
This creates an internally reinforced wall having greater strength and structural integrity than the wall 100 of FIGS. 3-4 . In the wall 200 according to the second embodiment, the subsequent rows are interdependent and interconnected to one another.
It will be understood that this pattern may be modified to make a wall of any desired height, and that for a different wall height, more of the base blocks 10 could be used between the top and bottom rows. For a higher wall, the second row would all be base blocks 10 , which could be repeated for additional rows as desired.
FIG. 7 illustrates that the wall 200 may also be made with some curvature therein, as desired, and may be used as a retaining wall for landscaping purposes.
Optional Finishing Block
Referring now to FIGS. 8-9 , an optional finishing block in accordance with the invention is shown generally at 50 . The finishing block 50 is provided for optional use in making an end wall face with a substantially smooth side edge. The block 50 has a first end 52 , which is substantially similar to the first end 20 of the base block 10 , as previously described. The first end 52 of the finishing block 50 has two spaced-apart fingers 54 , 56 extending outwardly thereon, which are the same size, shape and orientation as the first and second fingers 24 , 26 on the base block 10 .
The finishing block 50 also has a second end 60 with an outer edge 62 having a substantially smooth and unbroken surface. The outer edge 62 of the finishing block 50 can be oriented substantially vertically, or may alternatively be disposed at an angle with respect to the vertical, as shown.
FIG. 9 illustrates how the finishing block 50 may be combined with two of the base blocks 10 a , 10 b to form a series having a substantially smooth and unbroken outer edge.
Insert Member—Third Embodiment
An optional insert member 310 is shown in FIGS. 10-11 , according to a third embodiment of the invention. The insert member 310 is intended for use in conjunction with a hollow, plastic landscaping timber 390 .
The insert member 310 includes a reduced diameter section 384 for slidable placement inside of the open end 394 of the landscaping timber 390 , and a larger working section 386 having a plurality of fingers 324 and 326 thereon, which will nestingly interconnect with corresponding fingers on similar end block insert members. The landscaping timber has a plurality of holes 391 , 392 formed therein, and the reduced diameter section 384 of the insert member has corresponding three-dimensional extensions 387 , 388 protruding outwardly thereon for locking engagement in the holes 391 , 392 .
The structure of the working section 386 is similar to the corresponding portion of the base block 10 , as previously described. It will be understood that an insert in the orientation shown in FIG. 8 may be nestingly interengaged with a similar insert which has been inverted top-to-bottom and rotated 180 degrees from the orientation of the insert in the drawing.
Although the present invention has been described herein with respect to a limited number of presently preferred embodiments, the foregoing description is intended to be illustrative, and not restrictive. Those skilled in the art will realize that many modifications of the preferred embodiment could be made which would be operable. All such modifications, which are within the scope of the claims, are intended to be within the scope and spirit of the present invention.
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A building block includes a substantially rectangular block body, and may be used to make walls or edging for a landscaped area A first end of the block has spaced-apart fingers extending outwardly thereon. The outside corners of the finger tips are rounded off. The uppermost finger on the first end has an upper surface flush with the block top surface. Holes are formed coaxially through the fingers of the first end, with an axis substantially perpendicular to the block's longitudinal axis. Pins may be placed in the through holes to interconnect nested blocks. The second end is identical to the first end, rotated clockwise 180 degrees. Accordingly, the lowermost finger of the second end has a lower surface flush with the bottom surface of the block body. Multiple blocks may be combined with supplemental, reduced height blocks, and assembled in a staggered configuration to build a reinforced wall.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application relates to U.S. patent application Ser. No. 09/845,112 entitled “Overload Protection for a Disc Cutterbar” in the name of Timothy J. Kraus and Imants Ekis, filed on the same date as this application.
FIELD OF THE INVENTION
The present invention relates generally to mechanisms for protecting mechanical drive components from overloads, and more particularly to a brake coupled between components of an agricultural disc mower that quickly stops rotation of a cutterhead in the event the cutterhead strikes an object with sufficient force to activate a shear mechanism, allowing the cutterhead to rotate freely.
BACKGROUND OF THE INVENTION
Typical disc cutterbars used in agriculture include an elongated housing containing a train of meshed idler and drive spur gears, or a main power shaft coupled by respective bevel gear sets, for delivering power to respective drive shafts for cutterheads spaced along the length of the cutterbar. The cutterheads each comprise a cutting disc including diametrically opposed cutting blades (though configurations with three or more blades are known) and having a hub coupled to an upper end of a drive shaft, the lower end of the drive shaft carrying a spur gear in the case where a train of meshed spur gears is used for delivering power, and carrying a bevel gear of a given one of the bevel gear sets in the case where a main power shaft is used. In either case, bearings are used to support the various shafts. The cutterheads are rotated at a relatively fast speed making the drive components, such as gears, bearings and shafts, vulnerable to damage in the event that the unit strikes a foreign object. For background information on the typical structure and operation of some disc cutterbars, reference is made to U.S. Pat. No. 4, 815,262, issued to E. E. Koch and F. F. Voler, the descriptive portions thereof being incorporated herein in full by reference.
In order to minimize the extent of such possible damage to the drive components, it is known to incorporate a shear device somewhere in the drive of each unit which will “fail” upon a predetermined overload being imposed on the device. As used herein with reference to shear devices, the terms “fail” or “failing” are intended to cover the actual function of such devices, i.e., shearing, fracturing, breaking and the like. Several such shear devices and arrangements are shown in U.S. Pat. Nos. 4,999,981, 4,497,161 and 5,715,662.
A serious drawback of prior art disc cutterbars is that, while they may incorporate a shear device to reduce or eliminate damage to the drive system in the event of an overload, they do not provide means or mechanisms to stop rotation of the cutterhead after failure of the shear device. With multiple cutterheads in line, generating overlapping cutting paths, rotating at high speed and operating in a timed relationship, it is inevitable that when one fails it will lose its timed relationship with adjacent cutterheads, resulting in impacts and damage among the cutterheads comprising the cutterbar. Such damage is often significant not only in repair costs due to parts and labor, but also in lost harvesting time. The instant invention is directed to a brake mechanism that will stop further rotation of the cutterhead after failure of a shear device, thus preventing the damages described.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a brake in the mechanical drive train of a disc cutterbar that will not only stop the transfer of power along the drive train in the event of overload, but also stop rotation of the non-driven components before further damage can occur.
Another object of the present invention is to provide a brake and shear mechanism in the drive of a disc cutterbar that will not only cause the cessation of power transfer at a predetermined load, but will also stop the rotation of non-driven components within one rotation.
Yet another object of the present invention is to provide a disc cutterbar with multiple cutterheads, each comprising a drive shaft connected to a mounting hub via a shear mechanism. A novel brake mechanism is triggered upon failure of the shear mechanism, stopping rotation of the lower hub and cutterhead.
It is yet another object of this invention to provide an improved disc cutterbar that is relatively durable in construction, inexpensive of manufacture, carefree of maintenance, easy to assemble, simple and effective in use, and less likely than prior art cutterbars to sustain costly damage upon contact with a fixed object.
These and other objects, features and advantages are accomplished according to the instant invention by providing a disc cutterbar with at least one cutterhead having a two-piece mounting hub, one piece rotatably driven and the other supporting a knife for severing standing crop material, with an epoxy layer bonding the two pieces together and forming a shear device therebetween. A brake is associated with the knife-supporting piece whereby upon failure of said shear device, the knife-supporting piece is stopped from rotating within one revolution.
DESCRIPTION OF THE DRAWINGS
The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a top plan view of a disc mower mounted on the three-point hitch of a tractor, the disc mower having a modular disc cutterbar incorporating the principles of the instant invention, the rotational path of the individual disc members being shown in phantom, the disc mower being one of the configurations in which the improved disc cuttterbar of the instant invention can be utilized;
FIG. 2 is an enlarged top plan view of a central portion of the assembled modular disc cutterbar depicting two cutterhead modules and an interstitial spacer module, portions of the spacer modules on opposite sides of the cutterhead modules being broken away and the disc members being removed for clarity;
FIG. 3 is a cross-sectional view of the cutterhead module taken along line 3 — 3 of FIG. 1;
FIG. 4 is an enlarged view of a portion of FIG. 3;
FIG. 5 is a view similar to FIG. 4, showing an exaggerated view of the gap separating inner hub 42 and outer hub 43 after the shear mechanism has failed and the locking blocks have engaged;
FIG. 6 is an exploded cross-sectional view of the mounting hub, locking blocks and springs making up significant components of the instant invention;
FIG. 7 is a top plan view of the lower locking block taken along line 7 — 7 of FIG. 6;
FIG. 8 is a bottom plan view of the outer hub and integral upper locking block taken along line 8 — 8 of FIG. 6;
FIG. 9 is an exploded view somewhat rotated showing the relationship between the inner hub, the outer hub and the lower locking block;
FIG. 10 is a cross-sectional view of an alternative embodiment of the brake device taken along line 10 — 10 of FIG. 11; and
FIG. 11 is a view of an alternative locking block taken along line 11 — 11 of FIG. 10 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and particularly to FIG. 1, a modular disc cutterbar incorporating the principles of the instant invention can best be seen in a configuration in which the disc cutterbar is conventionally utilized. For a more detailed description of a conventional modular disc cutterbar and various configurations thereof reference is made to U.S. Pat. No. 5,996,323. The disclosure in that patent is hereby incorporated herein in its entirety by reference.
Cutterbar 30 is mounted in a disc mower 10 having a support frame 11 connected to the three-point hitch mechanism 3 of a tractor T on which the mower 10 is carried in a conventional manner. The disc mower 10 receives operative power from the conventional tractor power take-off shaft 5 . The mower drive mechanism. 15 receives the rotational power from shaft 5 and transfers the rotational power to a gearbox 17 , which in turn transfers the rotational power to the cutterbar drive mechanism.
An alternative configuration for the disc cutterbar would be to incorporate the cutterbar in a disc mower-conditioner. This well-known configuration is shown in more detail in U.S. Pat. No. 5,761,890, which is hereby incorporated herein in its entirety by reference. One skilled in the art and knowledgeable about commercial applications of disc cutterbars will readily recognize that there are other specific configurations of cutterbars to which the invention to be disclosed herein will be applicable. Such skilled individual will also readily recognize that the cutterbar need not necessarily be modular in construction.
Modular cutterbar 30 is formed from alternating cutterhead modules 40 and spacer modules 32 . Each cutterhead module 40 , as best seen in FIGS. 1-3, includes a hollow cast housing 41 (FIG. 3) having a shape to retain a low profile and to establish an oil reservoir 84 therewithin. As will be discussed in more detail below, the cutterheads 40 are gear driven and assembled in such a manner as to establish a specific timing relationship between adjacent units. More particularly, the cutterheads are arranged such that the knives 82 on adjacent units have overlapping cutting paths, but do not come into contact with each other. Failure to maintain this timed relationship during operation will result in one unit hitting the adjacent unit(s), damaging the cutterheads (and possibly initiating a chain reaction that damages all cutterheads), the drive train of the cutterbar and/or tractor T. In such case, the damage is usually significant.
Referring now to FIGS. 2-4, it can be seen that each cutterhead module 40 is provided with a forwardly positioned rock guard 65 and a skid shoe 70 that passes beneath cutterhead module 40 for engagement with the surface of the ground. The rock guard 65 has a conventional semi-circular configuration and is mounted to opposing forward mounting arms 35 of spacer module 32 adjacent to the corresponding cutterhead module 40 .
One skid shoe 70 is mounted beneath each cutterhead module 40 to protect the cutterhead module from wear due to engagement with the surface of the ground. Each skid shoe is formed as a generally planar body portion 71 with a mounting tab 73 affixed thereto and projecting upwardly. The body portion 71 is also formed with a forward end 72 that is bent upwardly to engage the corresponding rock guard 65 .
Modular drive mechanism 75 , best seen in FIGS. 2 and 3, is fully disclosed in the '323 patent and reference is made thereto for a more complete description.
Broadly, within each cutterhead unit there is a two-piece hub, one inner hub and one outer hub, normally held together by a shear mechanism. The inner hub is connected to a drive shaft, and the outer hub, including an integral upper locking block, is connected to a rotatable knife support member. Spaced below the outer hub is a fixed lower locking block. These components are arranged such that when a knife engages a solid or fixed object and a shear force generated adequate to cause the shear mechanism to fail, the outer hub rotates freely and drops (preferably under the influence of a downward biased spring) causing the upper and lower locking blocks to engage and the knife support member to cease rotation. By thus preventing the knives from rotating further, damage is prevented to the drive train of the cutterbar and between adjacent cutterhead units. Ideally, the brake will stop rotation in one revolution or less.
Now, and more specifically, attention is directed to FIG. 9 which shows an exploded perspective view of the inner hub 42 , the outer hub 43 and the lower locking block 44 . In the preferred embodiment, inner hub 42 is affixed to outer hub 43 by means of a layer of epoxy bonding surfaces 45 and 46 of the two hubs, respectively. By controlling the size of the bonded surface area of the two hubs, and knowing the shear strength of the epoxy, a specific shear point or force can be calculated so that failure will occur at the desired point and upon a specific impact. Outer hub 43 includes an upper locking block made up of spaced apart teeth 47 and 48 set within a circular recess 49 . Lower locking block 44 comprises protruding cylindrical member 50 with surface spaced apart teeth 51 and 52 . When assembled, as best seen in FIG. 4, protruding cylindrical member 50 fits rotatably part way into cylindrical recess 49 . Also as best seen in FIG. 4, before failure of the layer 53 cap 56 , inner hub 42 and outer hub 43 are fixed to and rotate with drive shaft 86 . After failure of layer 53 , outer hub 43 is free to rotate about drive shaft 86 , at least until the locking blocks engage. When engaged as discussed further below, the teeth on the respective locking blocks loosely fit together to prevent relative rotational movement between the two locking blocks.
Surfaces 45 and 46 may have generally any configuration or slope, so long as the outer hub can move into the locking position upon failure of layer 53 . The configuration shown has proven to be quite successful and functional.
One of skill in the art will recognize that there are many types of epoxy available that will work in this environment. By way of example, successful operation has been experienced with an epoxy known as “HP-120” by Loctight. A useful characteristic of epoxy, as used in the instant invention is that only a very thin layer is required to hold the hubs together, and when it fails, the material all but disappears. This feature is quite valuable and important from a practical point of view in that the cleanliness of shear failure promotes quick operation of the brake. Devices such as that shown in the '662 patent listed above would, upon failure of the shear device, present metallic debris that would interfere with, and “jam” up the brake disclosed herein.
While epoxy is disclosed as the preferred bonding or shear medium, there are other alternatives. For example, rubber, plastic, solder, brazing and the like could all be used. It is worthwhile to note that in the environment of a cutterhead, mechanical shear pins or similar fitted shear mechanisms tend to fail prematurely due to the fatigue experienced from the vibration and alternating stress inherent in the application.
FIG. 6 is an exploded cross-sectional view of the primary elements making up the preferred embodiment of the invention and is included herein for further clarity. The Belleville washers (springs) 54 and 55 are mounted in an opposing manner and shown here in their compressed state, but it can be clearly seen that when assembled the washers will exert a downward bias on outer hub 43 . Thus, if the epoxy bond between the inner and outer hubs 42 , 43 is broken, outer hub 43 will be biased to move downwardly.
FIGS. 7 and 8 are also presented for additional clarity. FIG. 7 is a top plan view of lower locking block 44 taken along line 7 — 7 of FIG. 6 . Looking at this view and FIG. 9 it can be seen that there are raised areas, or teeth, 51 and 52 extending partially around the circumference of the protruding cylindrically shaped portion 50 , forming lower interstitial areas 57 . FIG. 8 shows that outer hub 43 includes a portion 59 which is referred to as the upper locking block. Upper locking block 59 can be either integral with outer hub 43 , as shown here, or formed as a separate piece and affixed to outer hub 43 . Teeth 47 and 48 are spaced apart, forming lower interstitial areas 58 . Interstitial areas 57 and 58 are larger circumferentially than the respective teeth that are to be engaged therein. This difference in size is to allow time and space for the full engagement of the locking blocks upon failure of the shear layer. When assembled, the teeth of the two locking blocks are separated; however, if the epoxy bond fails, i.e., the shear mechanism fractures, outer hub 43 (and because they are integral, upper locking hub 59 ) drops into lower locking block 44 —teeth 51 and 52 drop into spaces 58 , and teeth 47 and 48 go into spaces 57 . The two locking blocks are thus “locked” together, stopping the rotation of outer hub 43 (and thus disc member 80 and knives 82 ). Lower locking block 44 is fixed in place, i.e., does not rotate and thus provides solid support for the locking function.
The number and configuration of teeth on the locking blocks can, of course, vary depending upon several factors such as the harness of the base materials, the speed of rotation, the mass of the cutterhead, and the timing required to stop the relative movement of the components. In addition, for similar reasons, it may be appropriate or beneficial to harden the teeth, add cushioning material to the interfering faces and/or add friction-reducing materials to the contacting surfaces.
Referring now to FIGS. 3-5, inner hub 42 is detachably splined onto a drive shaft 86 having an integral driven gear 77 positioned within the oil reservoir 84 . Inner hub 42 is affixed to outer hub 43 by a layer of epoxy 53 which, as described above, serves as a shearing device. A disc member 80 is detachably connected to outer hub 43 by bolts 81 so as to be rotatable therewith (and thus knives 82 ). The drive shaft 86 is rotatably supported by a bearing block 78 detachably mounted to the cutterhead module housing 41 by bolts 79 . The bearing block 78 seals an opening in the top of the housing 41 through which the driven gear can be extracted from the oil reservoir 84 .
When the cutterhead engages a fixed object of sufficient mass or rigidity to generate a shearing force on layer 53 , adequate to cause failure thereof, the inner and outer hubs 42 , 43 will separate and outer hub 43 will drop. In the preferred embodiment, outer hub 43 is biased downwardly by means such as Belleville washers 54 and 55 working between cap 56 and outer hub 43 . FIG. 5 shows this change in position of outer hub 43 (has moved downwardly on shaft 86 ) in exaggerated form for illustrative purposes.
The drive mechanism 75 in each cutterhead module 40 is coupled to the other cutterhead module drive assemblies 85 by a transfer shaft 94 that passes through the spacer module 32 , as best depicted in FIG. 2 . The transfer shaft 89 is splined at each opposing end thereof to be finally received within either of the hubs 89 , 90 to transfer rotational power thereto.
Referring now to the configurations of utilization of the cutterbar 30 as depicted in FIG. 1, it can be seen that the drive mechanism 75 in a disc mower 10 receives rotational power from a gearbox 17 that is supported adjacent the inboardmost cutterhead module 40 . Accordingly, the drive assembly 85 is connected directly to the output shaft (not shown) of the gearbox 17 . The transfer of rotational power to the remaining cutterhead modules 40 proceeds as described above.
FIGS. 10 and 11 show an important alternative structure to the brake. In the brake described above, the outer hub drops down to allow the locking blocks to engage. A potential problem with this arrangement is that crop materials and debris can build up on the lower part of the structure and potentially hinder or interfere with the quick engagement of the brake. While one could take steps and develop structure to reduce or prevent the build up of materials, the structure shown in FIGS. 10 and 11 eliminates the potential problem by causing the outer hub to move upward on the drive shaft 86 to engage the brake.
Inner hub 110 is connected to outer hub 112 by shear bolt 114 . Of course, instead of a shear bolt(s) a frangible layer as taught above could also be used as the shear device. Between the inner hub 110 and outer hub 112 is a spring 116 , in this embodiment a known wave spring, biasing the outer hub upwardly relative to inner hub 110 which is fixed to shaft 86 by, for example, splines. Annular lip 118 on cap 117 forms a stop against further upward movement of inner hub 110 . Thus, upon failure of the shear device, outer hub 112 moves upwardly away from inner hub 110 under the bias of spring 116 until it engages lip 118 of cap 117 .
Though the interlocking configuration of the locking blocks could be essentially the same as that described and shown in earlier Figures this embodiment shows a slight modification. Lower locking block 120 has an annular recess 122 into which flange 124 of outer hub 112 fits. As best seen in FIG. 11, lower locking block 120 has spaced apart annular lips 126 forming annular openings 128 which matingly match teeth (not shown) on flange 124 such that the teeth mate with openings 128 to lock outer hub 112 , when the shear device fails, in the manner described above. The dimensional relationship among the component parts is such that lip 118 stops upward movement of outer hub 112 at the same time the teeth on flange 124 move into openings 128 and engage the edges 130 of openings 128 .
It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.
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A disc cutterbar with at least one cutterhead having a two-piece mounting hub, one piece rotatably driven and the other supporting a knife for severing standing crop material, with an epoxy layer bonding the two pieces together and forming a shear device therebetween. A brake is associated with the knife-supporting piece whereby upon failure of said shear device, the knife-supporting piece is stopped from rotating within one revolution.
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PRIORITY TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser. No. 10/827,859, filed Apr. 20, 2004, now pending, which is a Continuation of U.S. application Ser. No. 10/255,290, filed Sep. 26, 2002, now abandoned, which claims the benefit of European Application No. 01123422.6, filed Sep. 28, 2001. The entire contents of the above-identified applications are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to pseudopolymorphic forms of (±)1-(4-carbazolyloxy)-3-[2-(2-methoxyphenoxy)ethylamino]-2-propanole (carvedilol) as well as of optically active forms or pharmaceutically acceptable salts thereof. The present invention also relates to processes for the preparation of such pseudopolymorphic forms of carvedilol and to pharmaceutical compositions containing them.
BACKGROUND
[0003] Carvedilol is a non-selective β-blocker with a vasodilating component, which is brought about by antagonism to the α 1 -adrenoreceptors. Moreover, carvedilol also has antioxidative properties. Carvedilol is the object of European Patent No. 0 004 920 and can be manufactured according to the processes described therein.
[0004] Carvedilol has a chiral center and, as such, can exist either as individual stereoisomers or in racemic form. Both the racemate and stereoisomers may be obtained according to procedures well known in the art (EP-B-0127099).
[0005] WO 99/05105 discloses a thermodynamically stable modification of carvedilol with a melting point of 123-126° C. (hereinafter referred to as carvedilol form I), compared to the carvedilol described in EP 0004920 having a melting point of 114-115° C. (hereinafter referred to as carvedilol form II).
[0006] At pH values in the pharmaceutically relevant range of 1 to 8 the solubility of carvedilol in aqueous media lies between about 1 mg and 100 mg per 100 ml (depending on the pH value). This has been found to be problematical especially in the formulation of highly concentrated parenteral formulations, such as e.g. injection solutions or other formulations for the production of small volume administration forms for ocular or oral administration.
[0007] In the case of the peroral administration of rapid release carvedilol formulations, e.g. the commercial formulation, resorption quotas of up to 80% are achieved, with a considerable part of the resorbed carvedilol being very rapidly metabolized.
[0008] In connection with investigations into the gastrointestinal resorption of carvedilol it has been established that the resorption of carvedilol becomes poorer during the course of passage through the gastrointestinal tract and e.g. in the ileum and colon makes up only a fraction of the resorption in the stomach. This has been found to be very troublesome especially in the development of retard forms in which a release should take place over several hours. The poorer resorption is presumably due entirely or at least in part to the decreasing solubility of carvedilol with increasing pH values. A very low solubility can also be established in the strongly acidic region (about pH 1-2).
[0009] In order to improve the resorption quota, especially in the lower regions of the intestine, investigations have been carried out for adjuvants and, respectively, formulations which are suitable for increasing the solubility and/or speed of dissolution of carvedilol.
[0010] Accordingly, one underlying purpose of the invention lay in improving the resorption of carvedilol, especially in the case of peroral administration and here especially in the lower regions of the intestine, using agents available in pharmaceutical technology.
BRIEF DESCRIPTION OF THE INVENTION
[0011] It now has surprisingly been found that the pseudopolymorphic forms of (±)1-(4-carbazolyloxy)-3-[2-(2-methoxyphenoxy)ethylamino]-2-propanole (carvedilol) according to the present invention, especially the hydrates of carvedilol, particularly carvedilol hemihydrate (hereinafter referred to as form IV), can be formulated at high concentrations in a composition further comprising certain selected adjuvants. Such compositions containing carvedilol form IV have a better active substance resorption and thus an improved bioavailability compared with formulations which contain carvedilol forms I or II.
[0012] Carvedilol can thus be isolated in different modifications depending upon the method of preparation. The three polymorphic forms are monotropic and distinguishable by their infrared and X-ray powder diffraction spectra and their melting point.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a depiction of the infrared (IR) spectrum of carvedilol form I.
[0014] FIG. 2 is a depiction of the infrared (IR) spectrum of carvedilol form II.
[0015] FIG. 3 is a depiction of the infrared (IR) spectrum of carvedilol form IV.
[0016] FIG. 4 is a depiction of the overlaid infrared spectra of carvedilol forms IV, I, and II.
[0017] FIG. 5 is a depiction of the X-ray powder diffraction pattern of carvedilol form IV measured using the methods set forth in the specification under the heading “FT-IR and X-ray diffractometry”.
[0018] FIG. 6 is a depiction of the X-ray powder diffraction pattern of carvedilol form II measured using the methods set forth in the specification under the heading “FT-IR and X-ray diffractometry”.
[0019] FIG. 7 is a depiction of the X-ray powder diffraction pattern of carvedilol form I measured using the methods set forth in the specification under the heading “FT-IR and X-ray diffractometry”.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In one preferable embodiment, he present invention provides a new crystalline modification (form IV) of carvedilol substantially free of other physical forms, having a melting point of approximately T Onset 94-96° C. measured by Differential Scanning Calorimetry. The IR spectrum of form IV shows great differences in the stretching vibration range (3526, 3492 and 3400 cm −1 ) compared to the spectra of forms I and II. The X-ray powder diffraction pattern of carvedilol form IV has characteristic peaks occurring at 2θ=7.0, 8.3, 11.5, 15.7, and 17.2.
[0021] As used herein, the term “pseudopolymorphic forms” relates to hydrates and solvates, preferably to hydrates. Pseudopolymorphic forms of carvedilol, such as hydrates and solvates, contain different amounts of water or solvents in the crystal lattice.
[0022] The term “hydrates” encompasses compounds with different amounts of water present in the crystal lattice, such as hemi hydrates, monohydrates, dihydrates, with hemihydrates being especially preferred.
[0023] “Pharmaceutically acceptable salts” of carvedilol embrace alkali metal salts, such as Na or K salts, alkaline earth metal salts, such as Ca and Mg salts, as well as salts with organic or inorganic acids, such as, for example, hydrochloric acid, hydrobromic acid, nitric acid, sulphuric acid, phosphoric acid, citric acid, formic acid, maleic acid, acetic acid, succinic acid, tartaric acid, methanesulphonic acid or toluenesulphonic acid, which are non-toxic for living organisms.
[0024] For the resolution of the racemates, there can be used for example tartaric acid, malic acid, camphoric acid or camphorsulphonic acid.
[0025] Where reference is made in this application to carvedilol form I, II and IV substantially free of other physical forms, it means that at least 75% by weight, preferably 90% by weight, more preferable 95% by weight of carvedilol form I, II or IV, respectively, is present in the preparation.
[0026] Pseudopolymorphic forms of carvedilol, i.e. hydrates and solvates, can generally be prepared by crystallisation out of solvents in which carvedilol is soluble, for example alcohols, such as methanol, ethanol and isopropanol, acetone, acetonitrile, chloroform, dimethylformamide, dimethylsulfoxide, methylenechloride or mixtures thereof or with water.
[0027] Furthermore, crystalline form IV of carvedilol can be prepared by isolation of form IV from spray congealed material of carvedilol, the preparation of which is described below, followed by re-crystallisation in methanol/water. Thus, carvedilol form IV was first isolated from spray congealed material prepared according to Example 4 of WO 01/74357. Furthermore, using carvedilol form II as starting material, seeding with carvedilol form IV ensures the crystallisation of form IV.
[0028] In a further aspect, the present invention provides pharmaceutical compositions comprising a pseudopolymorphic form of carvedilol, especially carvedilol form IV substantially free of other physical forms of carvedilol, a pharmaceutically acceptable carrier and/or adjuvant and, if desired, other active ingredients. Such compositions may be used for the treatment or prophylaxis of illnesses.
[0029] The compounds of the present invention may be administered by any suitable route, preferably in the form of a pharmaceutical composition adapted to such a route and in dose effective for the treatment intended. The compounds and compositions may, for example, be administered orally, intravascularly, intraperitoneally, subcutaneously, intramuscularly or topically. Preferred mode of administration is oral administration. The pharmaceutical composition may be in the form of, for example, a tablet, capsule, creme, ointment, gel, lotion, suspension or liquid. The pharmaceutical composition is preferably made in the form of a dosage unit containing a particular amount of the active ingredient. Examples of such dosage units are tablets or capsules.
[0030] Therapeutically effective doses of the compounds of the present invention required to prevent or arrest the progress of the medical condition are readily ascertained by one of ordinary skill in the art. The dose regimen for treating a disease condition with the compounds and/or compositions of this invention is selected in accordance with a variety of factors, including the type, age, weight, sex and medical conditions of the patient and in accordance to the severity of the disease and thus may vary widely. A suitable daily dose for a mammal may vary widely depending on the condition of the patient and other factors. However, a dose from about 0.01 to 100 mg/kg body weight, particularly from about 0.05 to 3 mg/kg body weight, respectively 0.01 to 10 mg/cm 2 skin, may be appropriate. The active ingredient may also be administered by injection.
[0031] For therapeutic purposes, the compounds of the invention are ordinarily combined with one or more adjuvants appropriate to the indicated route of administration. If per os, the compound may be mixed with lactose, sucrose, starch powder, cellulose esters of alkanoic acids, cellulose alkyl ester, talc, stearic acid, magnesium stearate, magnesium oxide, sodium and calcium salts of phosphoric and sulphuric acids, gelatine, acacia, sodium alginate, polyvinyl-pyrrolidone and/or polyvinyl alcohol, and thus tableted or encapsulated for convenient administration. Alternatively, the compound may be dissolved in water, polyethylene glycol, propylene glycol, ethanol, corn oil, cotton seed oil, peanut oil, sesame oil, benzyl alcohol, sodium chloride and/or various buffers. Appropriate additives for the use as ointments, cremes or gels are for example paraffin, vaseline, natural waxes, starch, cellulose, or polyethylenglycole (PEG). Other adjuvants and modes of administration are well and widely known in the pharmaceutical art.
[0032] Preferable pharmaceutical compositions containing a pseudopolymorphic form of carvedilol, especially carvedilol form IV, can be prepared with selected adjuvants which are not surface-active, such as polyethylene glycols (PEG) or sugar substitutes as well as non-ionic tensides, such as polyoxyethylene stearates, e.g. Myrj® 52, or polyoxyethylene-polyoxypropylene copolymers, e.g. Pluronic° F. 68.
[0033] The content of hydrophilic polyoxyethylene groups in the aforementioned polyoxy-ethylene-polyoxypropylene copolymers preferably lies at 70% to 90%. In an especially preferred embodiment the ratio of hydrophilic polyoxyethylene groups to hydrophobic polyoxypropylene groups lies at about 80:20 and the average molecular weight preferably lies at about 8,750.
[0034] The aforementioned polyoxyethylene stearates preferably have a hydrophilic-lipophilic balance (HLB) value of 10 to 20, preferably of 14 to 20, especially of 16 to 18.
[0035] From the series of sugar substitutes especially isomalt (hydrogenated isomaltulose), e.g. Palatinit®, has been found to be particularly suitable. Palatinit® is a hydrogenated isomaltulose, which consists of about equal parts of 1-O-α-D-glucopyranosyl-D-sorbitol and 1-O-α-D-glucopyranosyl-D-mannitol dihydrate.
[0036] Further, in connection with the present invention polyethylene glycols with a molecular weight of 200 to 20,000, preferably 1,000 to 20,000, more preferably 4,000 to 10,000, particularly 6,000 to 8,000, have been found to be especially suitable.
[0037] In a preferred embodiment of the present invention the carvedilol form I, II or IV is dissolved in a non-ionic tenside, preferably Pluronic® F 68, or in an adjuvant which is not surface-active, preferably polyethylene glycol 6,000.
[0038] Thus, carvedilol form I, II or IV can be dissolved in polyethylene glycol 6,000 which is melted at about 70° C. In this manner there are obtained highly concentrated compositions of carvedilol (up to 500 mg/ml). Moreover, further additives, for example cellulose derivatives such as hydroxypropylmethylcelluloses or hydroxypropylcelluloses, can be admixed in order to control the release rate of the active substance. Further, the compositions in accordance with the invention can contain highly dispersed silicon dioxide as an anti-caking agent.
[0039] In a preferred embodiment, the carvedilol form IV content in the compositions in accordance with the invention lies at 5% (wt./wt.) to 60% (wt./wt.), preferably at 5% (wt./wt.) to 50% (wt./wt.), especially at 10% (wt./wt.) to 40% (wt./wt.), with the weight % details relating to the total weight of the composition (active substance and adjuvant).
[0040] In a preferred embodiment the adjuvants in accordance with the invention have a melting point below 120° C., especially a melting point of 30° C. to 80° C.
[0041] The aforementioned adjuvants can be used individually or in a combination of two or more adjuvants with one another. The combination of an adjuvant which is not surface-active, preferably polyethylene glycol, with a non-ionic tenside, preferably a polyoxyethylene-polyoxypropylene copolymer, e.g. Pluronic® F 68, is especially preferred, since the addition of surface-active substances can accelerate the active substance release from the composition.
[0042] Compositions of carvedilol form IV which contain as adjuvants polyethylene glycol, preferably polyethylene glycol 6,000, as well as 0.1% to 50%, preferably 0.1% to 10%, of polyoxyethylene-polyoxypropylene copolymers, e.g. Pluronic® F 68, have been found to be especially suitable.
[0043] In a particular embodiment of the present invention the ratio of the aforementioned adjuvant which is not surface-active, for example polyethylene 6,000, to the surface-active adjuvant, for example Pluronic® F 68, lies between 1000:1 and 1:1, preferably between 100:1 and 10:1.
[0044] The compositions of carvedilol form IV in accordance with the invention and medicaments produced therefrom can contain further additives such as, for example, binders, plasticizers, diluents, carrier substances, glidants, antistatics, antioxidants, adsorption agents, separation agents, dispersants, dragéeing laquer, de-foamers, film formers, emulsifiers, extenders and fillers.
[0045] The aforementioned additives can be organic or inorganic substances, e.g. water, sugar, salts, acids, bases, alcohols, organic polymeric compounds and the like. Preferred additives are lactose, saccharose, tablettose, sodium carboxymethylstarch, magnesium stearate, various celluloses and substituted celluloses such as, for example, methylhydroxy-propylcellulose, polymeric cellulose compounds, highly dispersed silicon dioxide, maize starch, talcum, various polymeric polyvinylpyrrolidone compounds as well as polyvinyl alcohols and their derivatives. It is a prerequisite that all additives used in the production are non-toxic and advantageously do not change the bioavailability of the active substance
[0046] In a preferred embodiment the compositions in accordance with the invention contain carvedilol form IV in a substantially pure form, polyethylene glycol, polyoxyethylene-polyoxypropylene copolymer as well as highly dispersed silicon dioxide. In an especially preferred embodiment the compositions in accordance with the invention contain 10-20% (wt./wt.) carvedilol form IV, 65-85% (wt./wt.) polyethylene glycol, 1-10% (wt./wt.) polyoxyethylene-polyoxypropylene copolymer and 0.1-10% (wt./wt.) highly dispersed silicon dioxide, with the percentages relating to the total weight of the four named substances irrespective of whether additional adjuvants are present in the composition.
[0047] The compositions of carvedilol form IV in adjuvants can be prepared by dissolving carvedilol form I, II or IV in the molten adjuvants, followed by rapid solidification of the melt of the adjuvants with the dissolved active substance, e.g. by spray congealing. Alternatively, the compositions of carvedilol form IV in adjuvants can be prepared by dissolving the polymer carrier (PEG) in an appropriate organic solvent or solvent mixture (e.g. ethanol, methanol, isopropanol, acetonitrile, aceton or mixtures thereof and/or with water), followed by the addition of carvedilol form I, II or IV. Thereafter, the solvent is removed by spray drying. Storage at room temperature for about 1 to 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient. Depending on the conditions used in the spray solidification step, formation of form IV can be achieved within one week to several months.
[0048] The present invention is therefore also concerned with a process for the production of compositions of carvedilol form IV, which comprises the admixture of carvedilol with molten hydrophilic adjuvants, such as, for example, polyethylene glycol, and/or surface-active substances, such as, for example, Pluronic®F 68. Alternatively, the active compound and adjuvants may be mixed with subsequent melting. In a preferred embodiment the thus-obtained formulation is subsequently spray congealed.
[0049] In the case of spray drying, the material to be dried is sprayed as a solution or suspension at the upper end of a wide, cylindrical container through an atomizer arrangement to give a droplet mist. The resulting droplet mist is mixed with hot air (preferably >100° C.) or an inert gas which is conducted into the dryer around the atomization zone. The resulting solvent vapour is taken up by the drying air and transported away, and the separated powder is removed from the container via a separator.
[0050] In the case of spray congealing, the material to be solidified is sprayed as a melt at the upper end of a wide, cylindrical container through a heatable atomizer arrangement to give a droplet mist. The resulting droplet mist is mixed with cooled air (preferably <25° C.), which is conducted into the dryer around the atomization zone. The heat of congealing which is liberated is taken up by the air and transported away, and the separated solidified powder is removed from the container via a separator. As atomizer arrangements there come into consideration (heatable) pressure nozzles (e.g. pressure nozzle with swirl bodies), pneumatic nozzles (binary/ternary nozzles) or centrifugal atomizers.
[0051] The resulting compositions of carvedilol form IV can be advantageously used pharmaceutically in various ways. Thus, for example, such compositions can be processed further to rapid release administration forms, such as, for example, tablets, film tablets, capsules, granulates, pellets, etc. with an improved resorption quotient. This permits under certain circumstances a dosage reduction in comparison with conventional rapid release peroral medicaments which have been produced using crystalline carvedilol form II.
[0052] The resulting compositions of carvedilol form IV can also be used especially advantageously for the production of medicaments with a modified release characteristic. Under a modified release characteristic there is to be understood, for example, a 95% release after more than two hours, preferably after 2 to 24 hours, or a pH-dependent release in which the beginning of the release is delayed in time. For this purpose, the carvedilol compositions can be processed to or with all conventional pharmaceutical oral medicaments with modified release.
[0053] Examples of medicaments with a modified release characteristic are film tablets which are resistant to gastric juice or retard forms, such as e.g. hydrocolloid matrices or similar medicaments from which the active substance is released via an erosion or diffusion process. The formulations in accordance with the invention can be processed to formulations with modified active substance release by the addition of further adjuvants or film coatings or by incorporation in conventional pharmaceutical release systems. Thus, the formulations in accordance with the invention can be incorporated, for example, in hydrocolloid matrix systems, especially in those which are based on cellulose derivatives such as hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose or polyacrylate derivatives such as, for example, Eudragit RL. The aforementioned matrices can contain, additionally or alternatively, a hydrocolloid matrix former which swells depending on pH, such as, for example, sodium alginate or sodium carboxymethylcellulose. By the addition of such an adjuvant a targeted release which is individually determined can be achieved. Thereby, the use of the compositions in accordance with the invention leads to an appreciable improvement in the resorption in comparison to the crystalline carvedilol form IV as active substance.
[0054] Thus, the spray congealed compositions of carvedilol in accordance with the invention, preferably those comprising Pluronic® F 68, polyethylene glycol 6000, highly dispersed silicon dioxide and carvedilol (preferably in accordance with Example 4), can be pressed to tablets, for example, by direct compression, granulation and compacting together with hydrophilic matrix formers which control the release, such as e.g. hydroxypropylmethyl-celluloses 2208 with an average viscosity of about 100 mPa·s (Methocel® K100 LV-Premium) and hydroxypropylmethylcelluloses 2208 with an average viscosity of about 4000 mPa·s (Methocel® K4M-Premium), and with glidants or anti-caking agents, such as e.g. magnesium stearate and microcrystalline celluloses (Avicel® PH102). Moreover, the tablets can be coated with a conventional lacquer, such as e.g. Opadry® II White Y-30-18037 and Opadry® Clear YS-1-7006.
[0055] The pharmaceutical compositions in accordance with the invention are suitable for the production of conventional pharmaceutical administration forms, preferably oral administration forms, for the treatment and/or prophylaxis of cardiac and circulatory disorders, such as e.g. hypertension, cardiac insufficiency and angina pectoris.
[0056] The dosage in which the pharmaceutical compositions in accordance with the invention are administered depends on the age and the requirements of the patients and the route of administration. In general, for oral administration, single dosages of about 0.1 mg to 50 mg of carvedilol per day come into consideration. For this, formulations with a carvedilol active substance content of about 1 mg to 50 mg are used.
[0057] The present invention is therefore also concerned with a method for the treatment of illnesses, such as hypertension, cardiac insufficiency or angina pectoris, which comprises the administration of medicaments which contain the pharmaceutical formulations described above.
EXAMPLES
Characterization of Form IV of Carvedilol
Differential Scanning Calorimetry (DSC)
[0058] DSC (Differential Scanning Calorimetry) was carried out on a Mettler TA 8000 system with a DSC 821e, a sample robot and intracooler equipment. Dry nitrogen was used as purge gas (flow 150 ml/min) and dry gas (flow 150 ml/min). The scan rates were 5° C./min and 1° C./min (heating and cooling cycles) and the sample weigh ranging from 1 to 12 mg. Sealable 40 μl aluminum pans hermetically closed with a perforation lid were used. Prior to measurement the lid was automatically pierced resulting in approx. 1.5 mm pin holes. All measurements were performed with pierced lids. Calibration of temperature and heat of fusion was performed with 99.999% indium (Mettler-Toledo (Schweiz) AG; CH-Greifensee). Melting point 156.6° C.; Heat of fusion 28.45 J/g.
[0059] The measured melting point (T Onset) of carvedilol form IV was about 94-96° C. Heat of fusion of carvedilol form IV was ΔHf 144-154 J/g corresponding to 60-64 kJ/mol for the hemihydrate (molecular weight: 406.5+9).
[0060] TGA (Thermal Gravimetric Analysis) was carried out on a Mettler TA 8000 system with a TGA 851e and a sample robot and air cooling. Dry nitrogen was used as purge gas (flow 50 ml/min) and dry gas (flow 20 ml/min). The scan rates were 5° C./min and 1° C. min (heating and cooling cycles), the sample weigh ranging from 10 to 50 mg. Sealable 100 μl aluminum pans hermetically closed with a perforation lid were used. Prior to measurement the lid was automatically pierced resulting in approx. 1.5 mm pin holes. Sealed pans prevent any exchange of solvents and humidity with the atmosphere during the waiting position in the sample robot.
[0061] The determined weight loss (weight step) between 50° C. and 140° C. was approximately 2.2% (weight percent), corresponding to ½ mole of water for the molecular weight of the hemihydrate.
FT-IR and X-Ray Diffractometry
[0062] The IR-spectrum of the sample is recorded as film of a Nujol suspension consisting of approx. 15 mg of sample and approx. 15 mg of Nujol between two sodium chloride plates, with an FT-IR spectrometer in transmittance. The Spectrometer is a Nicolet 20SXB or equivalent (resolution 2 cm-1, 32 or 64 coadded scans, MCT detector).
[0063] X-ray powder diffraction was carried out with a Stoe X-ray diffractometer STADIP in transmission, Cu α1 -radiation, Ge-monochromator, rotation of sample during measurement, position sensitive detector (PSD), angular range 2° to 32° (2θ), steps of 0.50 (20), measuring time 40 seconds per step.
[0064] The X-ray powder diffraction pattern of form IV has characteristic peaks at 2θ=7.0°, 8.3° (is subdivided in two peaks at 8.235°+8.383°), 11.5°, 15.7°, and 17.2° ( FIG. 5 ). Characteristic peaks of the form II occur at 2θ=5.9°, 14.9°, 17.6°, 18.5°, and 24.4° ( FIG. 6 ) and of the form I at 10.5°, 11.7°, 14.3°, 18.5°, 19.3°, 21.2°, 22.1° ( FIG. 7 ).
[0065] Crystal data for C 24 H 26 N 2 O 4 *C 24 H 26 N 2 O 4 *H 2 O (two molecules carvedilol and one water molecule), monoclinic space group P2 1 /n, a=13.517(3)Å, b=16.539(3)Å, c=19.184(4)Å, β=94.27(3)°, V=4276.9(15) Å 3 , Z=8, Data were recorded on a STOE image plate detector using Mok α (graphite monochromator) radiation, a colourless crystal of dimensions 0.3×0.3×0.05 mm was used and a total of 5298 unique measurements collected. The structure was solved using direct methods and refined to a R factor of 0.0764. There are two molecules of carvedilol and one water molecule in the asymmetric unit of the crystal. The theoretical X-ray powder diffraction pattern calculated from this structure coincides well with the experimentally derived X-ray powder diffraction pattern of samples of crystal form IV.
[0066] The IR spectrum of carvedilol form IV shows the biggest differences compared to the spectra of carvedilol forms I and II in the stretching vibration range form IV 3400 cm −1 ; form I 3450 cm −1 ; form II 3345 cm −1 (see FIGS. 1 to 4 ), which are caused by different hydrogen bridges.
[0067] The following Examples are intended to describe the preferred embodiments of the present invention, without thereupon limiting this.
Example 1
Preparation of Spray Congealed Carvedilol
[0068] The spray congealed carvedilol used to isolate form IV was prepared according the following procedure: Macrogol 6000 (polyethylene glycol) is first molten at 70 to 85° C. Subsequent dissolution of Pluronic F 68 (polypropylene glycol) and carvedilol form II at 70 to 85° C. yields a melt with the following composition (batch size: approximately 10 kg): 16.84% carvedilol; 5.05% Pluronic F68 and 78.11% Macrogol 6000.
[0069] This melt is spray congealed using cold nitrogen (0 to 5° C.) via a heated two-fluid nozzle. The spray congealed material is collected using a cyclone separator. Prior to further use the batch is stored at 4 to 8° C. for 8 month.
Example 2
[0070] Process for Preparing Carvedilol form IV
[0071] 9 g of spray congealed carvedilol and 100 ml of distilled water are stirred over night at RT with a magnetic stirrer. The obtained suspension is filtered through a 0.45 μm filter and washed two times with 20 ml of distilled water. The filter cake is re-suspended in 100 ml of distilled water and stirred again over night. The so obtained suspension is again filtered through a 0.45 μm filter, washed two times with 20 ml of distilled water and dried in vacuum (10-15 mbar) at RT for at least 12 hours to yield approximately 1.6 g of form IV. The obtained form IV is characterised as described before.
[0072] To obtain pure form IV, 130 mg of the above isolated material is suspended in 3.25 ml methanol/water (90:10 v/v) and heated up to 50-60° C. until all material is dissolved. The solution is cooled down to RT during one hour and stored overnight at RT. The so obtained crystalline material is isolated and dried in a dry nitrogen stream to yield 70-100 mg of pure crystalline form IV. The obtained form IV is characterised as described before.
[0073] To obtain bigger crystals of form IV for X-Ray single crystal measurements, 100 mg of the above isolated material is suspended in 4 ml methanol/water (90:10 v/v) and heated up to 50° C.-60° C. until all material is dissolved. The solution is cooled down very slow from 55° C. to minus 10° C. during 50 hours. The so obtained crystalline material is isolated and dried in dry nitrogen stream to yield 50-80 mg of pure crystalline form IV. These obtained crystals were usable to perform X-Ray single crystal measurements.
Example 3
Process for Preparing Carvedilol form IV
[0074] 118 mg of carvedilol form II is suspended in 3 ml methanol/water (90:10 v/v) and heated up to 50-60° C. until a clear solution is obtained. The solution is cooled down to 40-50° C. and seeded with a small amount of crystallised form IV (obtained as described in Example 2). The seeded solution is cooled down to RT and stored over night at 5-8° C. The so obtained crystalline material is isolated and dried in dry nitrogen stream to yield 50-80 mg of pure crystalline form IV. The obtained form IV is characterised as described before.
Example 4
[0075]
Composition containing carvedilol form IV
Carvedilol
50.0 g
Polyethylene glycol 6,000
250.0 g
Total weight:
300.0 g
[0076] The polyethylene glycol 6,000 is melted at 70° C. The carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
Example 5
[0077]
Composition containing carvedilol form IV
Carvedilol
50.0 g
Polyethylene glycol 6,000
250.0 g
Total weight:
300.0 g
[0078] The polyethylene glycol 6,000 is melted at 70° C. The carvedilol form I is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
Example 6
[0079]
Composition containing carvedilol form IV
Carvedilol
50.0 g
Polyoxyethylene-polyoxypropylene copolymer
250.0 g
Total weight:
300.0 g
[0080] The polyoxyethylene-polyoxypropylene copolymer is melted at 70° C. The carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
Example 7
[0081]
Composition containing carvedilol form IV
Carvedilol
50.0 g
Polyoxyethylene-polyoxypropylene copolymer
15.0 g
Polyethylene glycol 6,000
235.0 g
Total weight:
300.0 g
[0082] The polyethylene glycol 6,000 is melted at 70° C. Subsequently, the polyoxyethlene-polyoxypropylene copolymer is stirred into the above melt, likewise melted and the melt is homogenized. The carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
[0083] If desired, the technical processing properties such as, for example, the flowability of the solutions can be improved by the addition of further adjuvants, see Example 9.
Example 8
[0084]
Composition containing carvedilol form IV
Carvedilol
50.0 g
Polyoxyethylene-polyoxypropylene copolymer
15.0 g
Polyethylene glycol 6,000
235.0 g
Total weight:
300.0 g
[0085] The polyethylene glycol 6,000 is melted at 70° C. Subsequently, the polyoxyethlene-polyoxypropylene copolymer is stirred into the above melt, likewise melted and the melt is homogenized. The carvedilol form I is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
[0086] If desired, the technical processing properties such as, for example, the flowability of the solutions can be improved by the addition of further adjuvants, see Example 9.
Example 9
[0087]
Composition containing carvedilol form IV
Carvedilol
50.0 g
Polyoxyethylene-polyoxypropylene copolymer
15.0 g
Polyethylene glycol 6,000
232.0 g
Silicon dioxide, highly dispersed
3.0 g
Total weight:
300.0 g
[0088] The polyethylene glycol 6,000 is melted at 70° C. Subsequently, the polyoxyethlene-polyoxypropylene copolymer is stirred into the above melt, likewise melted and the melt is homogenized. The carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. The carvedilol composition is then treated with highly dispersed silicon dioxide and mixed homogeneously. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
Example 10
[0089]
Composition containing carvedilol form IV
Carvedilol
50.0 g
Polyoxyethylene-polyoxypropylene copolymer
125.0 g
Polyethylene glycol 6,000
125.0 g
Total weight:
300.0 g
[0090] The polyethylene glycol 6,000 is melted at 70° C. Subsequently, the polyoxyethlene-polyoxypropylene copolymer is stirred into the above melt, likewise melted and the melt is homogenized. The carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
Example 11
[0091]
Composition containing carvedilol form IV
Carvedilol
50.0 g
Isomalt
450.0 g
Total weight:
500.0 g
[0092] The isomalt is melted at above its melting point. Subsequently, the carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
Example 12
[0093]
Composition containing carvedilol form IV - Rapid release tablets:
Carvedilol
50.0 g
Polyoxyethylene-polyoxypropylene copolymer
15.0 g
Polyethylene glycol 6,000
232.0 g
Silicon dioxide, highly dispersed
3.0 g
Tablettose
146.0 g
Sodium carboxymethylstarch
15.0 g
Silicon dioxide, highly dispersed
4.0 g
Magnesium stearate
10.0 g
Total weight:
475.0 g
[0094] The polyethylene glycol 6,000 is melted at 70° C. Subsequently, the polyoxyethlene-polyoxypropylene copolymer is stirred into the above melt, likewise melted and the melt is homogenized. The carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. The mixture is subsequently treated with highly dispersed silicon dioxide and mixed homogeneously. The mixture obtained is treated with tablettose and mixed. The outer phase (lubricant, flow agent, separating agent and extender) consisting of sodium carboxymethylstarch, highly dispersed silicon dioxide and magnesium stearate is added to the above mixture and mixed homogeneously. The resulting mixture is then pressed to pharmaceutical forms or filled into capsules in the usual manner taking into consideration the desired active substance content. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
Example 13
[0095]
Composition containing carvedilol form IV - Retard tablets:
Carvedilol
50.0 g
Polyoxyethylene-polyoxypropylene copolymer
15.0 g
Polyethylene glycol 6,000
232.0 g
Silicon dioxide, highly dispersed
3.0 g
Tablettose
146.0 g
Hydroxypropylmethylcellulose 2208
240.0 g
Silicon dioxide, highly dispersed
4.0 g
Magnesium stearate
10.0 g
Total weight:
700.0 g
[0096] The polyethylene glycol 6,000 is melted at 70° C. Subsequently, the polyoxyethlene-polyoxypropylene copolymer is stirred into the above melt, likewise melted and the melt is homogenized. The carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. The mixture is subsequently treated with highly dispersed silicon dioxide and mixed homogeneously. The mixture obtained is treated with tablettose and mixed. The outer phase (lubricant, flow agent, separating agent and extender), consisting of hydroxypropylmethylcellulose 2208, highly dispersed silicon dioxide and magnesium stearate is added to the above mixture and mixed homogeneously. The resulting mixture is then pressed to pharmaceutical forms or filled into capsules in the usual manner taking into consideration the desired active substance content. Storage at room temperature for about 2 months results in a composition containing carvedilol in substantially pure form IV as an active ingredient.
Example 14
[0097]
Composition containing carvedilol form IV - Retard tablets:
Carvedilol
50.0
g
Polyoxyethylene-polyoxypropylene copolymer
15.0
g
Polyethylene glycol 6,000
232.0
g
Silicon dioxide, highly dispersed
3.0
g
Tablettose
96.0
g
Hydroxypropylmethylcellulose 2208
240.0
g
Sodium alginate
50.0
g
Silicon dioxide, highly dispersed
4.0
g
Magnesium stearate
10.0
g
Total weight:
700.0
g
[0098] The polyethylene glycol 6,000 is melted at 70° C. Subsequently, the polyoxyethlene-polyoxypropylene copolymer is stirred into the above melt, likewise melted and the melt is homogenized. The carvedilol form II is stirred into the resulting melt and homogeneously dissolved. Then, the melt is spray congealed. Alternatively, the melt can be solidified by means of other methods, provided that the solidification takes place rapidly. The carvedilol composition is subsequently treated with highly dispersed silicon dioxide and mixed homogeneously. The mixture obtained is treated with tablettose and mixed. The outer phase (lubricant, flow agent, separating agent and extender), consisting of sodium alginate, highly dispersed silicon dioxide and magnesium stearate is added to the above mixture and mixed homogeneously. The resulting mixture is then pressed to pharmaceutical forms or filled into capsules in the usual manner taking into consideration the desired active substance content.
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The present invention is concerned with pseudopolymorphic forms of 1-(4-carbazolyloxy)-3-[2-(2-methoxyphenoxy)ethylamino]-2-propanole (carvedilol) or of optically active forms or pharmaceutically acceptable salts thereof, processes for the preparation thereof and pharmaceutical compositions containing them.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. application Ser. No. 10/786,285, filed Feb. 25, 2004 and incorporated herein in its entirety by reference thereto.
TECHNICAL FIELD
The present invention is directed to fire-suppression systems and, more particularly, to apparatuses and methods for suppressing a fire condition in an aircraft.
BACKGROUND
Current commercial jetliners with cargo compartments have fire-suppression systems as a safety feature in the event of a fire in the cargo compartment. The fire-suppression systems typically disperse Halon 1301 (bromotrifluoromethane—CF 3 Br) as the suppressant. The conventional fire-suppression systems also have multiple bottles of Halon 1301, each with its own discharge mechanism. In the event of a fire in the cargo compartment, fire suppression is achieved by an initial rapid discharge of Halon into the cargo compartment to establish a minimum Halon concentration of 5% or more by volume in the compartment. This initial high Halon concentration level provides effective and fast initial flame knockdown. Sustained fire suppression against deep-seated fire and conflagrations is achieved by maintaining the Halon concentration in the cargo compartment at or above 3%.
The typical fire-suppression systems on large commercial aircraft achieve the initial high Halon concentration level by very quickly releasing the entire contents of one or more high-rate discharge (HRD) bottles of Halon into the cargo compartment. After the HRD bottle(s) are discharged, the Halon concentration peaks and then slowly decreases toward approximately 5% during a period of approximately 20 minutes. In one fire-suppression system used on a Boeing 747-400, two HRD bottles are immediately emptied into a cargo compartment upon activation of the fire-suppression system. The HRD bottles provide approximately 110 pounds of Halon (55 pounds from each HRD bottle) into the cargo compartment to establish an initially high Halon concentration level, which is intended to slowly drop to at least 5%.
The Halon concentration in the cargo compartment is then maintained by providing a substantially continuous, regulated flow of Halon from a plurality of “metered” bottles over an elongated period of time. The metered bottles begin to discharge at a selected time delay after the HRD bottles are discharged. The metered bottles release Halon over an extended time period so the Halon concentration level is maintained at approximately 5%-7%, at least until the aircraft begins its descent to a safe landing.
When a commercial aircraft descends from a cruise altitude, the cargo compartment undergoes a repressurization. The cargo compartment also typically experiences an increase in a compartment leakage rate due to outflow valve effects. The repressurization and increased leakage rate effectively result in additional air being added into the cargo compartment, which causes the Halon concentration to decrease as the aircraft descends.
The conventional fire-suppression systems compensate for the decrease in Halon concentration during descent by maintaining a higher Halon concentration in the cargo compartment during the cruise phase before the descent phase. Accordingly, the Halon concentration level has room to drop as the aircraft descends, while not dropping below the 3% concentration minimum. For example, the metered bottles provide a continuous flow of Halon into the cargo compartment to maintain an elevated Halon concentration level of over 6% through the majority of the aircraft's flight after activation of the fire-suppression system. The Halon concentration level is maintained at this elevated level to compensate for the Halon concentration drop that will occur during descent of the aircraft to a safe landing. Accordingly, the conventional fire-suppression systems, when activated, must contain enough Halon to maintain the intentionally elevated Halon concentration during the flight time prior to descent. The aircraft, therefore, must carry hundreds of pounds of Halon on each flight to ensure that the fire-suppression system will have enough Halon to meet the minimum Halon concentration level requirements at all times in the event a fire condition occurs in one of the cargo compartments. The weight of the Halon negatively impacts the aircraft's fuel efficiency.
SUMMARY
Aspects of embodiments of the invention are directed to fire-suppression systems for an aircraft. One aspect of the invention includes a fire-suppression system for use in an aircraft having a cargo compartment. The fire-suppression system can include at least one fire-suppressant vessel, at least one discharge conduit coupled to the at least one fire-suppressant vessel, and a valve arrangement coupled to the fire-suppressant vessel and to the discharge conduit. The valve arrangement can have a first setting to discharge fire suppressant at a first discharge rate after activation of the fire-suppression system, a second setting to discharge the fire suppressant at a second discharge rate less than the first discharge rate, and a third setting to discharge the fire suppressant at a third discharge rate greater than the second discharge rate during descent of the aircraft.
Another aspect of the invention includes a method of suppressing a fire condition in a cargo compartment of an aircraft. The method can include detecting a fire condition in the cargo compartment, delivering fire suppressant into the cargo compartment at a first discharge rate after detection of the fire condition, delivering fire suppressant into the cargo compartment at a second discharge rate less than the first discharge rate, and delivering fire suppressant into the cargo compartment at a third discharge rate greater than the second discharge rate during descent of the aircraft.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top isometric view of an aircraft with a cargo compartment and a fire-suppression system in accordance with one embodiment of the present invention.
FIG. 2 is a schematic view of the fire-suppression system of FIG. 1 .
FIG. 3 is a schematic view of a fire-suppression system in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION
The following disclosure describes fire-suppression systems for use in a cargo compartment of an aircraft. Certain specific details are set forth in the following description and in FIGS. 1-3 to provide a thorough understanding of various aspects and embodiments of the invention. Other details describing well-known structures and systems often associated with aircraft, including cargo compartments, smoke detection and warning systems, and fire-suppression systems, are not set forth in the following description to avoid unnecessarily obscuring the description of the various embodiments of the invention.
Many of the details, dimensions, and other specifications shown in the figures are merely illustrative of particular embodiments of the invention. Accordingly, other embodiments can have other details, dimensions, and specifications without departing from the spirit or scope of the present invention. In addition, other embodiments of the invention may be practiced without several of the details described below.
FIG. 1 is a schematic top isometric view of an aircraft 10 with a fuselage 12 that contains cargo compartments, including a forward cargo compartment 16 a and an aft cargo compartment 16 b . The cargo compartments 16 a and 16 b are sized to receive cargo containers or pallets (not shown) that can include a vast assortment of different items, containers, and materials. A conventional fire detection system 20 (shown schematically) is provided in the cargo compartments 16 a and 16 b . The fire detection system 20 includes a plurality of detectors 22 configured to provide a signal to an aircraft control system 24 (shown schematically) upon detecting an actual or potential fire condition in one or both of forward and aft cargo compartments 16 a and 16 b . For purposes of clarity, the cargo compartment in which a fire condition is detected will be referred to in the following disclosure as “the target compartment 16 .” The control system 24 is configured to provide a warning to the operator of the aircraft 10 in the event at least one of the detectors 22 is activated in the target compartment 16 .
The aircraft 10 also includes a fire-suppression system 26 in accordance with at least one embodiment of the invention. The fire-suppression system 26 is coupled to the control system 24 and is activated manually or automatically by the control system if a fire condition is detected. The fire-suppression system 26 is configured to disperse a fire suppressant, such as Halon 1301, into the target compartment 16 . The fire suppressant is initially dispersed into the target compartment 16 at elevated levels to extinguish any flame that may be present in the target compartment 16 . The fire suppressant is also dispersed into the target compartment 16 over an extended period of time after the initial fire suppressant dispersal to maintain a selected fire suppressant concentration level that prevents any subsequent flare-ups. As the aircraft 10 begins its descent toward a safe landing, the amount of fire suppressant dispersed into the target compartment 16 is increased, thereby maintaining the selected fire suppressant concentration level throughout the descent.
The fire-suppression system 26 in accordance with one embodiment of the present invention includes a main line 28 that carries a flow of fire suppressant to the target compartment 16 . The flow of fire suppressant through the main line 28 can be directed to the target compartment 16 , whether it is the forward cargo compartment 16 a or the aft cargo compartment 16 b , in response to a command from the pilot or from an automatic command from the control system 24 .
A plurality of distributing lines 30 branch off from the main line 28 and are spaced apart from each other within the forward and aft cargo compartments 16 a and 16 b . Each of the distributing lines 30 terminates at a discharge nozzle 32 configured to disperse the fire suppressant into the respective forward cargo compartment 16 a or the aft cargo compartment 16 b . The distributing lines 30 and the discharge nozzles 32 are positioned so that, when the fire-suppression system 26 is activated, the fire suppressant will be dispersed substantially uniformly to rapidly achieve a uniform concentration of fire suppressant throughout the target compartment 16 .
As best seen in FIG. 2 , the main line 28 is connected to a plurality of pressurized bottles 34 that contain the fire suppressant. In other embodiments, the bottles 34 may contain Halon 1301 as the fire suppressant material, although fire suppressants other than Halon 1301 can be distributed through the main line 28 , the distributing lines 30 , and the discharge nozzles 32 into the target compartment 16 . The bottles 34 of the illustrated fire-suppression system 26 include two high-rate discharge (HRD) bottles 36 coupled to the main line 28 . In the illustrated embodiment, the fire suppressant is Halon 1301 and each HRD bottle 36 contains approximately 55 pounds of Halon 1301. Other embodiments can utilize HRD bottles 36 containing more or less fire suppressant per bottle. The HRD bottles 36 are configured to quickly discharge the fire suppressant into the main line 28 for delivery to the target compartment 16 when the fire-suppression system 26 is activated.
The HRD bottles 36 of the illustrated embodiment have valve mechanisms with a valve setting that allows the bottles to fully discharge into the main line 28 over a very short period of time (e.g., 2-3 minutes) as soon as the fire-suppression system 26 is activated. The fire suppressant from the HRD bottles 36 is distributed through the main line 28 and the distributing lines 30 and is dispersed from the discharge nozzles 32 throughout the target compartment 16 . The HRD bottles 36 in one embodiment delivers enough Halon into the target compartment 16 to provide an initial elevated concentration by volume of fire suppressant that peaks at approximately 5%-30% or more. The volume and concentration levels of the fire suppressant can be different in other embodiments, including embodiments using a fire suppressant other than Halon.
The high initial concentration level of fire suppressant extinguishes any flames that may be in the target compartment 16 . After the fire suppressant from the HRD bottles 36 is rapidly dispersed to suppress or extinguish any flames, no additional fire suppressant is added to the target compartment 16 for a selected time period (e.g., 18 minutes). During this time period, the fire suppressant concentration in the target compartment 16 is allowed to slowly drop to a predetermined acceptable level. For example, when the fire suppressant is Halon, the concentration is allowed to drop to the range of approximately 5%-9%, inclusive.
The bottles 34 in the fire-suppression system 26 also include a plurality of metered bottles 38 coupled to the main line 28 and also to the aircraft's control system 24 . Each of the metered bottles 38 of the illustrated embodiment contains approximately 80 pounds of Halon 1301 as the fire suppressant, although pressurized containers can be used that contain more or less fire suppressant. The metered bottles 38 are activated at a selected time by the control system 24 to dispense the fire suppressant into the target compartment 16 at a controlled discharge rate over an elongated period of time. The discharge rate of the fire suppressant from the metered bottles 38 is substantially less than the discharge rate of the fire suppressant from the HRD bottles 36 . In one embodiment, the metered bottles 38 are activated approximately 20 minutes after activation of the fire-suppression system 26 . Accordingly, the flow of fire suppressant from the metered bottles 38 is dispersed into the main line 28 and to the target compartment 16 after the HRD bottles 36 have been substantially emptied.
The metered bottles 38 are coupled to at least one regulator 40 that controls the flow of fire suppressant to the target compartment 16 . In the illustrated embodiment, one regulator 40 controls the flow of fire suppressant toward the forward cargo compartment 16 a , and another regulator controls the flow of fire suppressant to the aft cargo compartment 16 b . The regulators 40 provide a substantially continuous, metered flow of Halon to the target compartment 16 as the aircraft is flying along a cruise phase prior to descent toward a safe landing area.
In one embodiment wherein the fire suppressant is Halon, the metered bottles 38 and the regulators 40 can be configured to provide a flow of Halon into the target compartment 16 for up to 420 minutes or more while maintaining the Halon concentration level above 3%. In one embodiment, the metered bottles 38 provide Halon into the target compartment 16 to maintain a fire suppressant concentration level in the range of approximately 3.5%-4%, inclusive, after activation of the fire-suppression system 26 and prior to descent of the aircraft toward landing.
In one embodiment, the metered bottles 38 and the regulators 40 are configured with a setting to provide 0.9 pounds of Halon per minute into the target compartment 16 . Other embodiments can provide greater or fewer metered bottles 38 and regulators 40 or other flow restricting devices with valve settings that provide a flow of Halon greater or less than 0.9 pounds per minute, so as to maintain the concentration of Halon within the cargo compartment above the 3% minimum during at least the cruise phase and prior to descent of the aircraft.
The fire-suppression system 26 of the illustrated embodiment also includes at least one supplemental bottle 42 of fire suppressant coupled to the main line 28 . One or more flow restricting devices 44 are provided between the supplemental bottle 42 and the main line 28 to control the flow of fire suppressant from the supplemental bottle toward the target compartment 16 . The restriction devices 44 can include regulators or other flow control devices. The supplemental bottle 42 and the restriction devices 44 are coupled to the aircraft's control system 24 and are configured to be activated to disperse additional fire suppressant into the target compartment 16 as the aircraft 10 ( FIG. 1 ) begins to make its descent toward landing.
When the supplemental bottle 42 is activated in one embodiment, fire suppressant from the supplemental bottle is directed into the main line 28 and is added to the flow of fire suppressant from the metered bottles 38 flowing toward the target compartment 16 . Accordingly, fire suppressant is added to the target compartment 16 at a greater rate during the descent phase as compared to the rate at which the fire suppressant is delivered from the metered bottles 38 alone prior to descent. In another embodiment, the entire flow of fire suppressant to the target compartment 16 is only provided from one or more supplemental bottles 42 during descent. Accordingly, the flow rate of fire suppressant from the one or more supplemental bottles 42 can be greater than the flow rate of fire suppressant from the metered bottles 38 . In a further aspect of this embodiment, the flow rate of fire suppressant from the supplemental bottle 42 is less than the flow rate from the HRD bottles 36 .
In the illustrated embodiment, the fire-suppression system 26 is configured so the supplemental bottle 42 begins to disperse the fire suppressant at approximately the initiation of the aircraft's descent toward a safe landing area. The supplemental bottle 42 contains enough fire suppressant to be dispersed into the target compartment 16 for up to approximately 20 minutes, which corresponds to the duration of an aircraft's typical descent.
As the aircraft 10 ( FIG. 1 ) descends, the forward and aft cargo compartments 16 a and 16 b are repressurized, which results in air being adding into the cargo compartments. The forward and aft cargo compartments 16 a and 16 b may also experience increased compartment leakage because of the outflow valve effects during descent. Accordingly, adding additional air through repressurization and losing fire suppressant through increased leakage would ordinarily result in a decrease in the fire suppressant concentration level within the target compartment 16 if the discharge rate of fire suppressant into the target compartment were not increased. The supplemental bottle 42 provides an increased discharge rate of fire suppressant into the target compartment 16 to maintain the fire suppressant concentration above the 3% minimum during the entire descent to counteract the decrease in concentration that would otherwise result.
The supplemental bottle 42 of the illustrated embodiment contains approximately 55 pounds of Halon and provides a flow of Halon lasting for approximately 20 minutes during the aircraft's descent. Accordingly, as an example, the flow of Halon from the supplemental bottle 42 provides an increased discharge rate of Halon during the descent phase so the Halon concentration level in the aft cargo compartment 16 b remains in the range of approximately 3.5%-4%, inclusive. In one embodiment, the supplemental bottle 42 adds an additional 1.1 pound per minute of Halon 1301 flowing to the target compartment 16 during descent. In other embodiments, the supplemental bottle 42 can provide more or less additional fire suppressant at greater or lesser flow rates.
The fire-suppression system 26 of the illustrated embodiment is configured so the supplemental bottle 42 is activated either automatically or in response to a operator's command at approximately the beginning of the aircraft's descent. In other embodiments, the fire-suppression system 26 can be configured to activate the supplemental bottle 42 at a trigger point other than at the beginning of the aircraft's descent. For example, the supplemental bottle 42 can be activated based upon the aircraft's altitude, the aircraft's descent rate, the temperature in the target compartment 16 , or other triggering event.
The supplemental bottle 42 in the fire-suppression system 26 is configured to provide the extra fire suppressant into the target compartment 16 when needed during the descent phase to compensate against a concentration drop resulting from the concurrence of increased air pressure and compartment leakage. Accordingly, excessive amounts of Halon do not need to be provided into the target compartment 16 for an extended time period prior to descent to maintain an overly high concentration level that can compensate for a drop in the fire suppressant level during the descent. Therefore, less fire suppressant needs to be carried in the fire-suppression system 26 , which provides significant weight and cost savings for the aircraft.
In another embodiment, shown in FIG. 3 , the supplemental bottle 42 can be eliminated and its function carried out by the regulators 40 and the metered bottles 38 . The regulators 40 control the fire-suppressant flow rate from the metered bottles 38 , which is substantially less than the fire-suppressant flow rate from the HRD bottles 36 . In this embodiment, a bypass line 46 is provided between the metered bottles 38 and the main line 28 . The bypass line 46 allows at least a portion of the fire suppressant from the metered bottles 38 to bypass the regulators 40 and flow toward the target compartment 16 at an increased flow rate.
At least one restriction device 48 can be connected to the bypass line 46 and configured to provide a fire-suppressant flow rate to the main line 28 greater than the fire-suppressant flow rate through the regulators 40 but less than the flow rate from the HRD bottles 36 . The restriction device 48 can be a regulator, a flow diverter, an adjustable flow valve, or other flow control device. The restriction device 48 , when activated, allows a flow of fire suppressant from the metered bottles 38 to bypass the regulators 40 , so an increased flow of fire suppressant is carried through the main line 28 and delivered to the target compartment during the aircraft's descent phase.
The restriction device 48 can be activated automatically or in response to a command from the operator. The restriction device 48 can be activated at a trigger point corresponding to, for example, a selected amount of time after activation of the fire-suppression system 26 , at the initiation of the aircraft's descent phase, at a selected altitude, at a selected descent rate, or at another selected trigger point. Accordingly, additional fire suppressant is provided into the target compartment 16 during the aircraft's descent phase to maintain the fire suppressant concentration at a generally constant level throughout the descent.
When the fire-suppression system 26 of the foregoing embodiment is activated in response to an actual or potential fire condition in the forward or aft cargo compartment 16 a and 16 b , the fire suppressant from the HRD bottles 36 is quickly discharged and dumped into the target compartment 16 , as discussed above. Approximately 20 minutes after the activation of the HRD bottles 36 , the metered bottles 38 are activated. Fire suppressant from the metered bottles 38 flows through the regulator 40 to provide the metered flow of fire suppressant through the main line 28 to the target compartment 16 . The fire suppressant from the metered bottles 38 is dispersed into the target compartment 16 at a selected rate to maintain the fire suppressant concentration above the 3% minimum. In one embodiment wherein the fire suppressant is Halon, the flow of Halon from the metered bottles 38 maintains the Halon concentration in the range of approximately 3.5%-4%, inclusive, over a time period of up to 420 minutes or more.
When the aircraft 10 ( FIG. 1 ) begins its descent phase, the restriction device 48 is activated by the control system 24 to allow fire suppressant from the metered bottles 38 to flow through the bypass line 46 to the main line 28 , bypassing the regulators 40 . The fire suppressant from the bypass line 46 provides an increased fire-suppressant flow rate to the target compartment 16 as compared to the fire-suppressant flow rate prior to descent and activation of the restricting device 48 . Accordingly, increased amounts of fire suppressant from the metered bottles 38 are provided into the target compartment 16 to maintain the fire suppressant concentration in a selected range. When the fire suppressant is Halon, the Halon concentration in the target compartment 16 is maintained in the range of approximately 3.5%-4%, inclusive, and at least above the 3% minimum, during the entire descent phase of the aircraft's flight until landing.
In one embodiment, the restricting device 48 can be sequentially or continuously adjusted to provide an increasing fire-suppressant flow rate into the target compartment 16 during the entire descent of the aircraft 10 ( FIG. 1 ). The fire-suppression system 26 can minimize the amount of fire suppressant needed in the metered bottles 38 to provide the fire-suppression protection required for the aircraft's forward and aft cargo compartments 16 a and 16 b.
In still another embodiment, the regulators 40 in this embodiment can include one or more adjustable devices controlled by the control system 24 or another controlling device. The regulators 40 can be adjusted at selected times during an actual or potential fire condition to change the fire-suppressant flow rate to the target compartment 16 . The regulators 40 can be adjusted prior to or during descent of the aircraft, so the fire-suppressant flow rate is sequentially or substantially continuously increased throughout the descent phase.
In another embodiment, the multiple bottles of fire suppressant and multiple regulators or restriction devices can be eliminated and their functions carried out by a single tank or container of fire suppressant and a valve arrangement that controls the fire-suppressant flow rate into the target compartment 16 . The valve arrangement can then be adjusted to provide a high flow rate of fire suppressant into the target compartment 16 immediately after activation of the fire-suppression system 26 . The valve arrangement can be adjusted to reduce the fire-suppressant flow rate during the aircraft's cruise phase for efficient distribution of the fire suppressant. The valve arrangement can also be adjusted at a selected time, such as at the beginning of the aircraft's descent, to increase the fire-suppressant flow rate throughout the aircraft's descent until landing. Accordingly, the fire suppressant concentration is maintained at a generally constant level during descent, thereby compensating for the effects of repressurization and increased leakage in the target compartment
The fire-suppression system 26 of the embodiment discussed above provide benefits over the prior art. As an example, the fire-suppression system 26 is configured to provide increasing amounts of fire suppressant into the target compartment 16 only when needed to maintain the fire suppressant concentration within a selected range to compensate for the effects of pressurization and increased leakage in the target compartment. Accordingly, reduced amount of fire suppressant can be efficiently dispersed into the target compartment 16 as needed to maintain the fire suppressant concentration at or slightly above a selected minimum during the cruise and descent phases of the aircraft's flight. The fire-suppression system 26 , therefore, provides highly desirable cost and weight savings for the aircraft because excessive fire suppressant need not be carried by the fire-suppression system 26 .
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. For example, aspects of the systems and methods described above or the context of particular embodiments can be combined or eliminated in other embodiments. Many of the foregoing embodiments were described in the context of particular fire suppressant, particular suppressant concentration levels, particular flow rates and particular capacities. In other embodiments, any of the foregoing systems can be configured to handle different fire suppressants, maintain different fire suppressant concentrations, deliver different flow rates and/or share different capacities of fire suppressants. Accordingly, the invention is not limited except as by the appended claims.
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A fire-suppression system for use in an aircraft having at least one cargo compartment is disclosed. Methods of suppressing a fire in the cargo compartment are also disclosed. The fire-suppression system, under one aspect of the present invention, can include at least one fire-suppressant vessel, at least one discharge conduit coupled to the at least one fire-suppressant vessel, and a valve arrangement coupled to the fire-suppressant vessel and the discharge conduit. The valve arrangement can have a first setting to discharge a fire suppressant at a first discharge rate after activation of the fire-suppression system, a second setting to discharge the fire-suppressant at a second discharge rate less than the first discharge rate, and a third setting to discharge the fire-suppressant at a third discharge rate greater than the second discharge rate during descent of the aircraft.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Korean Patent Application No. 2002-29200, filed on May 27, 2002, which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention generally relates to semiconductor memory devices and, more specifically, to circuits and methods that enable screening for defective or weak memory cells in a semiconductor memory device.
BACKGROUND OF THE INVENTION
Due to the demand for increased data storage capacity and density of memory cells of semiconductor memory devices, such devices are being designed with smaller design rules. This demand applies to static random access memory devices (SRAMs), for example, where physical damage and topological miss-alignments in cell areas can generate defective memory cells. Defective or weak memory cells can result in abnormal leakage current flowing through the memory cells during standby states. Efficient and accurate methods for detecting or screening for defective memory cells are important for saving costs of fabrication and testing.
One method that has been proposed for screening for defective memory cells is disclosed, for example, in Japanese Patent Publication No. 1996-312097, and is illustrated in FIG. 1 Referring to FIG. 1 , a semiconductor switch 1 is connected between a power supply line Vdd and PMOS transistors M 1 and M 2 of a SRAM cell. Data is written into the cell when the switch 1 is turned on. The switch 1 is turned off after the writing operation and then returns to a turn-on state after a predetermined time of the turn-off state has elapsed to perform a read operation for the cell. A cell will be deemed to be defective or weak cells if the cell is not successful in reading data after it has been written with the data during the turn-on state of the switch 1 .
Another technique to check defective or weak cells is to test performance of data retention in the cell (referred to as “VDR test”) with a power supply voltage. In the VDR test, a modified power supply voltage level of a tester is applied into a SRAM and the data retention capability is verified after an internal power supply voltage level maintains a constant voltage level.
However, the VDR test requires modification of the power supply voltage of the tester, a power recovery time, and a time for settling the internal power supply voltage in the SRAM, which increases the testing time.
Therefore, methods and circuits for effectively and efficiently screening for defective or weak memory cells of a semiconductor memory device are highly desirable.
SUMMARY OF THE INVENTION
The present invention is directed to circuits and methods for efficiently screening for defective or weak memory cells in semiconductor memory devices.
According to one embodiment of the invention, a semiconductor memory device comprises a power supply voltage, a memory cell, a first driver for supplying the power supply voltage to the memory cell in response to a cell power control signal, and a second driver for supplying a voltage lower than the power supply voltage to the memory cell in response to a cell power down signal.
The first driver is preferably a PMOS transistor that is controlled by the cell power control signal and the second driver is preferably a NMOS transistor that is controlled by the cell power down signal.
According to another embodiment of the invention, a semiconductor memory device comprises a power supply voltage, a plurality of sub-memory blocks, each comprising a plurality of memory cells arranged in rows and columns, a plurality of column decoders and bitline sense amplifiers associated with corresponding sub-memory blocks, sub-row decoders disposed between the sub-memory blocks, and drivers for supplying the power supply voltage to the memory cells in response to a cell power control signal.
These and other embodiments, aspects, features, and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments, which is to be read in connection with the accompanying drawings, in which like reference characters denote the same or similar components.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a SRAM memory cell for illustrating a conventional method for screening for defective memory cells.
FIG. 2 is a diagram illustrating a method for screening for defective memory cells according to an embodiment of the invention.
FIG. 3 is a circuit diagram of a cell power signal generator according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating a method for screening for defective memory cells according to another embodiment of the invention.
FIG. 5 is a circuit diagram illustrating a cell power signal generator according to another embodiment of the invention.
FIG. 6 is an exemplary timing diagram illustrating a method for screening for defective memory cells according to an embodiment of the invention.
FIG. 7 schematically illustrates an architecture of a memory cell array in a SRAM memory device in which screening methods of the present invention may be implemented.
FIG. 8 is a schematic diagram of a memory cell array that is capable of performing screening of a block of memory cells according to an embodiment of the invention.
FIG. 9 is a schematic diagram of a memory cell array that is capable of performing screening of a block of memory cells according to another embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following description, exemplary embodiments of the invention are discussed in detail to provide a thorough understanding of the present invention. It is to be understood, however, that the description of preferred embodiments is for purposes of illustration and that nothing herein should be construed as placing any limitation of the invention. Indeed, it will be apparent to those of ordinary skill in the art that present invention may be practiced without these specific details
FIG. 2 illustrates a circuit construction that is used for screening a SRAM cell according to an embodiment of the present invention. Referring to FIG. 2 , a SRAM cell comprises a CMOS-type cell, including PMOS transistors M 1 and M 2 , and NMOS transistors M 3 ˜M 6 . The transistors M 1 ˜M 4 are cross-coupled with their gates, drains, and sources to form latch circuits 210 , 220 , as is well known in the art. Each NMOS transistor M 5 and M 6 is connected to a respective bitline BL and BLB, and has a gate that is coupled to a common wordline WL.
The sources of PMOS transistors M 1 and M 2 are connected to a first internal voltage VDDC through a driver 10 . Preferably, the driver 10 is a PMOS transistor which connects the first internal voltage VDDC to the sources of the PMOS transistors M 1 and M 2 (i.e., connects the first internal voltage VDDC to the SRAM cell) in response to a cell power control signal CPENB. With this circuit, a screening method according to the invention can use the cell power control signal CPENB to perform either a wafer-level test or a package-level test.
FIG. 3 illustrates a control circuit according to an embodiment of the present invention which is preferably used for generating the cell power control signal CPENB that controls the driver 10 (FIG. 2 ). The control circuit comprises first and second test pads 22 and 24 , a cell power control circuit 26 , an AND gate 28 , and a NOR gate 30 . The first test pad 22 receives an input signal for a wafer-level test mode while the second test pad 24 receives an input signal for a package-level test mode. The cell power control circuit 26 (which is preferably a type of JTAG (Joint Test Action Group) test mode circuit) generates a cell power-off signal CPZ to set a cell power-off mode for test sources to test a semiconductor memory device in response to the input signal supplied to the second test pad 24 .
The AND gate 28 receives as input the cell power-off signal CPZ and the input signal from the second test pad 24 , and the NOR gate 30 outputs the cell power control signal CPENB in response to an output of the AND gate 28 and the input signal from the first test pad 22 .
The cell power control signal CPENB is active with a “low” logic level when the input signal from the first test pad 22 is a “high” logic level or when the output of the AND gate 28 is a “high” logic level. In FIG. 2 , the driver 10 supplies the first internal voltage VDDC into the SRAM cell when the cell power control signal CPENB input to the driver 10 is a “low” logic level.
More specifically, in a wafer-level test mode, the first internal voltage VDDC is supplied into the SRAM cell in response to the cell power control signal CPENB, in response to an input pulse signal of a “high” logic level to the first test pad 22 , regardless of the output of the cell power control circuit 26 . In a package-level test mode, the cell power-off signal CPZ output from the cell power control circuit 26 affects the activation of the cell power control signal CPENB to supply the first internal voltage VDDC into the SRAM cell.
FIG. 4 illustrates a circuit construction that is used for screening a SRAM cell according to another embodiment of the present invention. In FIG. 4 , two drivers 10 and 40 are connected in parallel between the first internal voltage VDDC and the SRAM memory cell. The driver 10 is the same as in FIG. 2 . The second driver 40 is preferably an NMOS transistor which connects the first internal voltage VDDC into the SRAM cell (i.e., the sources of the PMOS transistors M 1 and M 2 ) in response to a cell power down signal CPDN. With the second driver 40 , the first internal voltage VDDC is lowered by a threshold voltage (Vt) of the NMOS transistor.
FIG. 5 is illustrates a control circuit according to another embodiment of the present invention, which is used for generating the cell power control signal CPENB that controls the driver 10 and the cell power control signal CPENB that controls driver 40 . The control circuit comprises a buffer 45 connected to a first test pad 41 , a JTAG test circuit 46 including a cell power control circuit 47 and an internal voltage trimming circuit 48 that are connected to a second test pad 42 , a NAND gate 51 which receives the output signal CPZ of the cell power control circuit 47 and an input from the second test pad 42 , and first and second internal voltage converters 49 and 50 , which convert first and second external voltages 43 and 44 , into first and second internal voltages VDDC and VDD, in response to an output of the internal voltage trimming circuit 48 . An output of the buffer 45 is the cell power down signal CPDN and an output of the NAND gate 51 is the cell power control signal CPENB. The cell power down signal CPDN is essentially the voltage level of a signal supplied through the first test pad 41 . The cell power control signal CPENB is activated with a “low” logic level in response to an input of a “high” logic level from the second test pad 42 and the output CPZ of a “high” logic level from the cell power control circuit 47 . A cell power down signal CPDN having a “high” logic level turns on the second driver 40 to supply a voltage VDDC-Vt into the cell, wherein Vt is a threshold voltage of the NMOS transistor of the second driver 40 . A cell power control signal CPENB having a “low” logic level turns on the first driver 10 to supply the first internal voltage VDDC into the cell.
Since the cell power control signal CPDN causes the cell to be connected directly with the voltage of VDDC-Vt, there is no waiting time for turning a voltage level lower in a tester. This advantageously provides a reduction of the test time for screening defective memory cells.
FIG. 6 is an exemplary timing diagram illustrating a method for screening defective memory cells according to an embodiment of the present invention. Referring to FIG. 6 , a test signal from the second test pad 42 maintains a “high” logic level during clock cycles C 2 ˜C 7 of clock signal XCLK of the JTAG test circuit 46 , and maintains a “low” logic level during clock cycles C 8 ˜C 15 . The test signal of the second test pad 42 pulses with a “high” level every two clock cycles during C 16 ˜C 24 . The output CPZ of the cell power control circuit 47 becomes active with a “high” logic level during the clock cycles C 2 ˜C 24 which the test signal appears at the second test pad 42 . The cell power control signal CPENB is generated in accordance with the test signal of the second test pad 42 . When the cell power control signal CPENB is at a “high” logic level, the first internal voltage VDDC is not supplied into the cell.
Before the clock cycle C 2 (period TACW), the cell power control signal CPENB of a “low” level causes the first internal voltage VDDC to be supplied into the cell and a writing operation is thereby performed for all cells. During the clock cycles C 2 ˜C 7 (period TWCS) when the cell power control signal CPENB maintains a “high” logic level, the first internal voltage VDDC is not supplied into the cell, which provides a time window for performing a screening operation for defective or weak cells. After that, during the clock cycles C 8 ˜C 15 (period TACR) when the cell power control signal CPENB is set to a “low” logic level, a read operation is performed for all cells.
Sub-sequent to clock cycle C 16 (period TWC), read and write operations are performed for every cell. The writing operation (i.e., 1-cell writing) is performed at clock cycles C 16 , C 18 , C 20 , C 22 , and C 24 while the cell power control signal is at a “high” level. At this time, each cell is compulsively put into the write mode even without a supply of the first internal voltage VDDC. Moreover, after each 1-cell writing, 1-cell read operations are carried out at clock cycles C 17 , C 19 , C 21 , and C 23 . During such operations, the read-out data is compared with the written data and defective cells are found when two data of a given cell are different from each other.
FIG. 7 schematically illustrates an architecture of a memory cell array in a SRAM memory device in which screening methods of the present invention may be implemented. In FIG. 7 , a SRAM device comprises first to fourth sub-memory cell blocks SCB 0 ˜SCB 3 , sub-row decoders SRD, column decoders YPATH, write drivers WDRV, bitline sense amplifiers BSA, drivers 61 ˜ 64 , a power supply pad 65 , and a power supply line 66 . In the sub-memory cell blocks SCB 0 ˜SCB 3 , the cells are arranged in a matrix of row and columns. The column decoders YPATH, write drivers WDRV, and bitline sense amplifiers BSA are located the bottom of the sub-memory cell blocks SCB 0 ˜SCB 3 . The sub-row decoders SRD are interposed between the first and second sub-memory cell blocks, SCB 0 and SCB 1 , and between the third and fourth sub-memory cell blocks, SCB 2 and SCB 3 . A unit block 60 comprises two sub-memory cell blocks (SCB 0 and SCB 1 , or SCB 2 and SCB 3 ), a sub-row decoder SRD, two column decoders YPATH, two write drivers WDRV, two bitline sense amplifiers BSA, and two drivers ( 61 and 62 , or 63 and 64 ). The power supply pad 65 is connected to the drivers 61 ˜ 64 through the power supply line 66 . The drivers 61 ˜ 64 preferably each comprise a PMOS transistor (such as the driver 10 shown in FIG. 2 ) that is disposed between the sub-row decoder SRD and the bitline sense amplifier BSA. The drivers 62 and 64 supply the first internal voltage VDDC into the memory cells arranged in the lower part of the sub-memory cell blocks. The drivers 61 and 63 are disposed at the upper side of the sub-row decoder SRD and supply the first internal voltage VDDC into the memory cells arranged in the tipper part of the sub-memory cell blocks.
FIGS. 8 and 9 are schematic diagrams of a memory cell arrays that are capable of performing screening of memory cells blocks according to embodiments of the invention, wherein a power control signal CPENB is used as decoding signals for blocks of memory cell. In FIGS. 8 and 9 , the unit blocks 60 of FIG. 7 are arranged in main memory cell blocks MCB 0 ˜MCB 3 . Each main memory cell block is coupled to a main row decoder MRD for selecting the sub-memory cell blocks SCB 0 ˜SCB 3 embedded in the main memory cell block.
More specifically, in FIG. 8 the cell power control signal CPENB is applied to a pre-decoder 70 for performing a screening process for all the main blocks. An output of the pre-decoder 70 is applied to the main row decoders MRD. When the cell power control signal CPENB is enabled, the main row decoders MRD are activated and the first internal voltage VDDC is supplied into the main memory cell blocks MCB 0 ˜MCB 3 .
On the other hand, in FIG. 9 , the cell power control signal CPENB is applied to each of a plurality of block decoders BDC. When the cell power control signal CPENB is enabled to supply the first internal voltage VDDC into each of the sub-cell blocks SCB 0 ˜SCB 3 , the main row decoders MRD select the sub-memory cell block to be supplied with the first internal voltage VDDC. Thus, the decoding of the cell power control signal CPENB may allow different screen modes, one mode for screening entire cell blocks or another mode for screening one or more cell block units.
As described above, circuits and methods for screening for defective or weak memory cells according to the present invention provide a reduced test time for screening since no time is needed for settling a test voltage lower than the power supply voltage in a tester.
Moreover, the invention enables screening operations in either a wafer-level test mode or a package-level test mode in accordance with a test signal supplied through a test pad. Furthermore, screen operations can be performed for either entire memory cell blocks or for memory cell block units, which provides flexibility of the number of memory cell blocks to be tested.
Although preferred embodiments of the present invention have been described for illustrative purposes, those of ordinary skill in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. For example, the present invention may be applicable to screen operations for other type memory cells not the SRAM cells. It is to be understood that all such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.
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Circuits and methods that enable screening for defective or weak memory cells in a semiconductor memory device. In one aspect, a semiconductor memory device comprises first and second drivers for a SRAM cell. The first driver is connected between a power supply voltage and the cell, which supplies the power supply voltage into the cell in response to a cell power control signal. The second driver is connected between the power supply signal and the cell, which supplies a voltage lower than the power supply voltage into the cell in response to the cell power down signal. A method for screening for defective or weak cells does not require a time for stabilizing a circuit condition after voltage variation to supply the voltage lower than the power supply voltage from a conventional tester because the cell power down signal activates a driver that causes a supply voltage that is lower than the power supply voltage to be loaded directly to the cell, which results in a reduction of the test time for screening defective cells.
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This is a division of application Ser. No. 108,020, filed Oct. 13, 1987, now U.S. Pat. No. 4,899,425.
BACKGROUND OF THE INVENTION
The present invention is directed to a process and apparatus for straightening weft yarns in fabrics.
Such process is known generally from Textile Practice International, Oct. 1986, pages 1115-1116. During the production of a normal fabric in a weaving machine, the warp and weft yarns intersect precisely at right angles. However, during the different working cycles in the equipment, the fabric can often become distorted. This distortion must be compensated or eliminated for different reasons.
Straightening devices of different kinds are available for correcting weft yarn distortions. The essential question here concerns roller assemblies disposed diagonal to each other. In addition, there are known differentially operating straightening machines wherein both chain drives of a tentering frame are controlled differently so as to align the weft yarns perpendicular to the direction of advance. But in all these straightening machines, it is necessary, in the first place, to determine the course of the weft yarns to be able then to carry out an adequate motor-driven adjustment of the straightening elements.
An essential advantage of the alignment when tension is simultaneously applied in the direction of the weft yarn is that the S-shaped and wavy distortions, etc. are automatically compensated to a great extent due to the stretch of the fabric.
It has been known for many years that an "automatic" compensation of the distortion can be obtained by needling the edges of the fabric web on wheels which have their axes of rotation disposed diagonally to the direction of movement in a manner such that the fabric web is substantially needled without width elongation and is then stretched during the (partial) rotation. The wheels here are free-wheelingly fastened upon their shafts. As long as the weft yarns are perpendicular to the direction of movement, that is, without distortion, the forces acting upon both wheels are equal during the tension. But as soon as a diagonal distortion is present in the fabric, a force acts between the wheels in the longitudinal direction of the fabric that brakes the wheel to the side with the "current" weft yarns and accelerates the wheel to the other side (lagging weft yarn). Among others, an essential problem here consists in that the needling on the wheels is really different and often results in the fabric being torn or moving down from the wheel. In published European Pat. Application No. 136,115, there is described an assembly in which this disadvantage can be prevented. But even in this assembly, the needling is relatively difficult. Moreover, an additional problem appears in this assembly (as also in the former assemblies). Such problem directly results from the fact that the clamping wheels move freely and the fabric is removed by a take-up roller so that a curved distortion occurs since the fabric has been "braked" on its edges.
OBJECTS AND SUMMARY OF THE INVENTION
Departing from the above cited prior art, the problem to be solved by this invention is to develop a process and apparatus of the kind mentioned in the sense of improving the straightening of the distortion.
This problem is solved by the process and the apparatus as disclosed herein.
The above and other objects, features and advantages of the invention will be apparent from the following detailed description which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top plan view of a first preferred embodiment of the invention;
FIG. 2 is a schematic top plan view of another preferred embodiment of the invention;
FIG. 3 is a longitudinal cross-sectional view through a drag hinge of the apparatus of FIG. 1;
FIG. 4 is a longitudinal cross-sectional view of FIG. 3, taken along line IV--IV thereof;
FIG. 5 is a schematic side elevational view of the whole assembly with a drum according to FIG. 1 or 2;
FIG. 6 is a schematic representation of the drum with tension straps;
FIG. 7 is a cross-sectional view of FIG. 6, taken along line VII--VII thereof;
FIG. 8 is a longitudinal cross-sectional view through a drum hub according to FIG. 2;
FIG. 9 is a cross-sectional view of FIG. 8, taken along line IX--IX thereof;
FIG. 10 is a side view of another preferred embodiment of the invention;
FIG. 11 is a block diagram for control of the assembly according to FIG. 10;
FIG. 12 is a schematic side elevational view of another preferred embodiment of the invention with segmented drums in a representation similar to the one of FIG. 5;
FIG. 13 is a cross-sectional view through the hub of the rums according to FIG. 12 in a representation similar to FIGS. 3 and 8;
FIG. 14 is a cross-sectional view of FIG. 13, taken along line XIV--XIV thereof;
FIG. 15 is a schematic side elevational view, partly in section, of a segmented tensioning drum;
FIG. 16 is a graphical diagram of a course of the elongation over the angle of rotation of a segmented or not segmented drum;
FIG. 17 is a graphical diagram of the course of the diameter of the tensioning drum according to FIG. 15 over the angle of rotation; and
FIG. 18 is a plan view of another preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a fabric web 8 is guided via two tensioning drums of means, 1, 1' in a manner such that the width of fabric 8 is less at the inlet than at the outlet. In addition, as will be described herebelow in more detail, the fabric web is retained on peripheral areas 7, 7' of tensioning drums and guided along over a defined peripheral angle. The peripheral areas 7, 7' are fastened via spoke elements 4, 4' on turn sleeves 28, 28' which are non-rotationally connected with a shaft 6 via hinges described in more detail below. Shaft 6 is driven by a driving motor 41.
Herebelow is described, in more detail with reference to FIGS. 3 and 4, the flexible connection between drums 1, 1' and the drive shaft 6.
According to FIGS. 3 and 4, a sliding sleeve 11 rests on shaft 6 and is rotationally secured via balls 13 that move in grooves 12 and 14 in sliding sleeve 11 and shaft 6. In the axial direction of shaft 6, sleeve 11 is thus movable with only slight friction.
On the sliding sleeve 11 rests a carrier sleeve 16 which carries on its periphery an outer toothing 50 that has a spherical outer surface. The ball center rests on the point of intersection of the axis of rotation of shaft 6, and symmetrically with respect to the front surface of the toothing 50.
An inner toothing 51 placed in a second carrier sleeve 16' meshes with outer toothing 50, the carrier sleeve 16' preferably being made of two pieces to make it easier to produce toothing 51. The sleeve 16' is thus non-rotationally connected with sleeve 16 but it can be tilted about the ball center of the toothing perpendicular to shaft 6.
Upon sleeve 16' is supported a turn sleeve 28 via ball bearing 19 and axial-radial bearings 17. Between turn sleeve 28 and carrier sleeve 16' is a free-wheel 22 consisting of an outer portion 26 firmly connected with turn sleeve 28 and having a groove that contains a lock spring 24 which presses a shim 23 upon the outer peripheral areas of an inner portion 27 which is firmly connected with carrier sleeve 16'. This kind of assembly ensures that rotation of turn sleeve 28 is possible in the direction of the arrow (FIG. 4) in respect to inner portion 27 and thus to shaft 6. The direction of drive of shaft 6 is here likewise in the direction of the arrow; and fabric web 8 is likewise guided in the direction of the arrow beyond the outer peripheral areas 7, 7', which are retained by spoke elements 4, 4' upon turn sleeve 28. In this manner, the drum peripheral area and therewith the edge of the fabric web concerned can advance in respect to the drive movement and not lag behind.
A guide portion 18 rests on sleeve 16' on the side of the shaft end, and is supported likewise via ball bearing 19 or axial/radial bearing 17. For this purpose, carrier sleeve 16' is correspondingly elongated. A guide lever 52 is attached to guide portion 18 and can be loaded with a pivotal force via a guide slider 53.
Guide slider 53 is moved by a cylinder 54, 54' that is stationary or movable only parallel with shaft 6 (see FIG. 1) so that this movement is then transmitted to pivotal movement of the spoke elements. In this pivoted state, which is also shown in FIG. 2, the drum can rotate while being simultaneously carried along by driven shaft 6. The attachment of free-wheel 22 between outer carrier sleeve portion 16' and turn sleeve 28 has, at the same time, the advantage that the free-wheel is more easily started than when free-wheel 22 is mounted between inner carrier sleeve portion 16 and sliding sleeve 11.
As further shown in FIG. 3, a force recorder 49 is provided on the lever 52 (or any other adequate place), which, in the embodiment shown in FIG. 3, can be, for example, a pair of elastic measuring tapes. The tension force applied to the fabric in the weft direction can be determined by force recorder 49. Via the output signal of force recorder 49, it is thus possible to lead a control apparatus (not shown here but known per se) which actuates slider 53 according to the force that appears so that to protect the fabric, there can be maintained a maximum force as a threshold.
Other features essential to the invention result from FIG. 5. In this figure is diagrammatically shown a side view of the assembly according to FIG. 1 or 2. On the outer peripheral area 7 of each drum is situated a multiplicity of gripping elements 3. The drum 1 (and also the opposite drum 1') is driven via a driving motor 41.
Fabric web 8 is fed to the straightening drums 1, 1' via a guide roller 36 and a centering roller 36' by a carrier roller 34. Carrier roller 34 is driven with adjustable speed by a motor 35. To ensure a specially exact alignment of the distorted fabric and in addition to prevent the curved distortions, it is necessary to avoid as far as possible longitudinal tractive forces when feeding and removing the web from drums 1, 1'. According to FIG. 5, this is further assisted by ascertaining the speed of removal of the fabric web by measuring the speed of a roller 37 with a tach/generator 38 and using it for synchronous control of driving motor 41 of drum 1 and of driving motor 35 of roller 34. For precise correction of the roller speed and for complete relief of tension, the fabric hangs before and behind drums 1, 1', forming in each a loop whose length is detected by light barriers 40 and 40'. Light barrier 40 rectifies the speed of the motor 35 in a manner such that the length of loop 39 remains constant. Light barrier 40' rectifies the speed of driving motor 41 of drums 1, 1' to the constant length of loop 39'.
When gripping elements 3 are designed as friction cushions, as shown in FIG. 7, a tension strap assembly such as shown in FIGs. 6 and 7 is adequate for pressing it on the drums. In this assembly, a tension strap 9 which is guided by tension rollers 10, synchronously rotates with drum 1 so that a fabric web 8 comes to lie between tension strap 9 and pressure element 3. This assembly ensures that in case of a side elongation that has inadvertently been too firmly adjusted, fabric web 8 can overcome the frictional force and become slightly loosened. There are preferably situated on the outer peripheral area 7, a multiplicity of sensors 47 which detect the position of the fabric edge relative to gripping elements 3. The output signals of sensors 47 serve to adjust or limit the side elongation which in turn is accomplished via guide slider 53 or the coordinated guide cylinder 54.
Another essential feature of the assembly shown in FIG. 3 consists in the axial mobility of drums 1, 1' which is effected via a tension flange 20 connected via an axial/radial bearing with the carrier sleeve 16 and which can be adjusted via a tension cylinder 21. Therefore, this adjustment is always in the direction of shaft 6.
Herebelow is described in more detail, the hub of the drum used in the embodiment according to FIG. 2, and in this regard, reference is made to FIGS. 8 and 9.
In this preferred embodiment of the invention, a carrier sleeve 16 rests, likewise non-rotationally, on shaft 6 via a sliding sleeve 11 and balls 13 which can roll in ball grooves 12 and 14 of sliding sleeve 11 or of shaft 6, so as to be movable in the axial direction of the shaft. A turn sleeve 28 moves above sliding sleeve 11 via ball bearings 19, there being likewise provided between turn sleeve 28 and sliding sleeve 11, a free-wheel 22. Such a free-wheel is again shown more precisely in FIG. 9, the numbers shown in FIGs. 8 and 9 corresponding to parts already described in detail in FIG. 3.
In order to effect a displacement of turn sleeve 28 in the axial direction of shaft 6, there rests on carrier sleeve 16, via an axial/radial bearing 17, a spring flange 20 which can be moved by a stationary tensioning cylinder.
Flanged portions 29 are provided on turn sleeve 28 and spoke elements 4 which carry at their ends the drum peripheral area 7 with gripping elements 3 attached thereto are fastened by screws thereto.
Therefore, in the two preferred embodiments of the invention that have hitherto been described, both drums 1, 1' are driven with a minimum velocity determined by the speed of driving motor 41. As soon as a propelling moment, due to a diagonal distortion in the fabric, acts upon drum 1 or 1', the drum can advance by sliding shims 23 upon the outer peripheral area of inner portion 27 so that the diagonal distortion can be adjusted.
In another preferred embodiment of the invention that is not shown in detail here, there is provided, instead of a free-wheel in each drum hub, a differential gearing (differential) between the driving motor and both drums so that the torques applied to the drum are equal. Therefore, the lagging drum in this case is not accelerated by the force present in the diagonal distortion of the weft yarn so that the distortion adjusts itself, but the forces are kept equal by the differential, which in the effect thereupon passes out.
Herebelow is described in more detail with reference to FIGS. 10 and 11 another preferred embodiment of the invention wherein again an equality of force is concerned. In this preferred embodiment of the invention, a driving motor 41, 41' is coordinated with each drum 1, 1', such motors being controlled via the output signals of speed transmitter 38 and of light barrier 40' (see FIG. 5). In this embodiment of the invention, there are provided between drums 1, 1' and motors 41, 41', torque transmitters 42, 42' which measure the torque applied by motors 41, 41' to drums 1, 1' and convert it into an electric output signal. Both measured values are compared. The comparison value serves to correct the speed of one of the two driving motors (motor 41' in FIG. 10) and this is accomplished via a regulator R and a servo amplifier. The control system 46 thus formed results in motor 41' always applying the same torque to drum 1' as motor 41 does to drum 1. As described in connection with FIG. 5, the speed of motor 41 is determined via speed transmitter 38 of roller 37, the precise control of the speed being effected via analog light barrier 40'. The control is such that when loop 39' becomes longer, motor 41 is driven more slowly (and vice versa).
By this arrangement, it is ensured that a more exact compensation of the distortion can be effected by means of control system 46 since regulator R of control system 46 can be designed as a PID regulator which can prevent the residual errors that occur in mere proportional regulators of the differenatial gearing and free-wheel types.
Herebelow is described with reference to FIGS. 12 to 17 another preferred embodiment of the invention wherein the main solution is again the operability of the drums to avoid curved distortion.
Unlike the previously described embodiments of the invention, in this preferred embodiment, the drums themselves are not rigid so that they must be placed diagonally to the feed direction of fabric web 8. In this preferred embodiment, drums 1, 1' are, on the contrary, divided into segments 2, 2' likewise held via spoke elements 4, 4' on the hub of the drum, spoke elements 4 being in this case articulated via hinges 5 on the hub or drum segment 2. This is best seen diagrammatically in FIG. 15.
According to this figure, in this preferred embodiment of the invention, the drum comprises separate segments 2 having peripheral areas 7 with an adequate curvature. The hinges 5 by which separate segments 2 are held over spoke elements 4, 4',are designed in a manner such that peripheral areas 7 can be displaced parallel with turn sleeve 28 (see FIGS. 13 and 15) or with shaft 6 upon which turn sleeve 28 is rotatably fastened, but stationary in the axial direction. Due to the fact that spoke elements 4, 4' are equally long, the parallelism between shaft 6 and peripheral surface 7 is always ensured. In FIG. 15 is shown only a "right" drum opposite to a "left" drum 1' constructed with mirror symmetry with the drum shown in FIG. 15. The direction of movement of the fabric is from top to bottom.
The gripping elements 3 on the outer side of the fabric are provided on the drum peripheral area 7 or the separate peripheral areas of segments 2. They can also be screw plates controlled by a force with or without needles, needle rows (optionally impressed in the fabric and removed) or simple frictional elements, as it has been already described above.
The spacing between left and right gripping elements 3 is determined by cranks 30 whose edges 31, shown in FIG. 15, serve as axial guide elements. When the edge 31 of the crank 30 is wholly in one plane, the crank 30 has the shape of a diagonally cut cylinder. As in the previously described embodiments, there results in this case a sinusoidal movement of the gripping elements 3, as shown by the dotted line in FIG. 16. According to the movement of gripping elements 3, there results likewise a sinusoidal side elongation d over the angel of rotation W of the drum. This movement of elongation corresponds to the elongation described above which is effected with the rigid drums.
However, in the embodiment of the invention shown in FIG. 15, there is no limitation to this purely sinusoidal movement of elongation. Since segments 2 can be moved independently of each other, it is possible substantially to effect any desired course of elongation by adequate shaping of crank 30. In FIG. 16 is shown, by way of example, a linear movement (traced curve) in which the fabric is increasing extended with uniformity over an angular value of more than 180°. By this step, it is possible to carry out the elongation movement more slowly and uniformly so as to protect the fabric. In addition, it is possible to effect the elongation passing over a larger angular range, which produces a stronger adjustable force (in the direction of movement) resulting from the sum of the forces applied to the separate weft yarns. Therefore, the bearing friction of the sleeve 28 on the shaft 6 carries less weight in the compensation operation, which is important in the embodiments having free-wheel.
Another advantage of the assembly shown in FIGS. 12 to 15 is that the edges of the stretched fabric are moved not only to the right, that is, outwardly in FIG. 15, but simultaneously also, in a direction toward shaft 6, whereby the radius r1 changes to the radius r2, which in turn means a change of the periphery of the drum. After the radius (and therewith the periphery of the drum) decreases, as shown in FIG. 17, there also results a compensation of the longitudinal tension of the fabric due to the lateral extension.
Another feature that makes this invention especially versatile in its use results from FIG. 15. Crank 30 is actually movably supported on turn sleeve 28 in a manner such that maximum movement of gripping elements 3 toward the right (for the right drum) is adjustable by means of the diagrammatically shown crank adjusting means 32. Movement to the left or gripping elements 3 is limited by the detents 33. If the adjusting means 32 in FIG. 15 are moved to the left, there results the motion curve C shown in the dotted line in FIG. 16. Such a motion curve ensures that the fabric web is specially reliably fed to and removed from the drum, since a more certain angular range is available to bring the fabric in frictional or positive (needling) engagement with the drum without the occurrence of a relative movement of an unfixed edge of the fabric in respect to the tensioning means.
Other motion curves can obviously be advantageously used for other reasons. It is, for example, possible to adapt the motion curve to the force/elongation course of the fabric in the lateral direction so as to obtain a constant increase of force during the extension.
The construction of this segmented drum is shown in more detail in FIG. 13 wherein this embodiment of the invention, differs from the one according to FIG. 8, on the one hand, by the double number of spoke elements and, on the other, by the fact that crank 30 is supported on guide portion 18. For the rest, the same parts are described with the same reference numerals as in FIG. 8 and are not further explained herein.
As to the detector elements described in connection with FIG. 7, in the segmented design of the drum, the lateral elongation is adjustable by a displacement of crank 30.
As it results from the preceding description, the individual elements of the invention can be combined, especially in what concerns the free-wheel and the separate operability and design of the drums as "rigid" or segmented separate structural parts. It is of course always important that the drums can be driven whereby longitudinal distortions can be avoided and there can be used a loop guidance of the fabric web, as shown in FIGs. 5 and 12.
Another preferred embodiment of the invention is shown in FIG. 18, wherein tensioning means 1, 1' form a (short) tentering frame which in the embodiment shown, comprises in a manner known per se, vertical tractor chains in which are provided screw plates (not shown) which marginally grip, by the edges, fabric web 8 at the inlet and again release it at the outlet. Both tractor chains are driven by a common motor 41 and shaft 6 thereof, there being provided in the driving wheels for the tractor chains, free-wheel assemblies 22 already described above in connection with the drum versions. In this manner, each tractor chain can advance the other but does not remain behind the speed determined by motor 41.
In another embodiment of the invention that is not shown in a figure, both tractor chains are driven not via a single motor with free-wheel but via a drive according to FIG. 11.
From the above representation it can be seen that what is important is that the tensioning means can be driven in a manner such that at least one force advancing in the direction of movement (due to a diagonal distortion) can be compensated by free-wheel, differential, or readjustment of a motor torque.
Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it will be appreciated that the present invention is not limited to those precise embodiments, and that various changes and modifications can be made by one of ordinary skill in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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A process and apparatus for straightening weft yarns in fabrics in which a continuous fabric web is stretched over a defined longitudinal section with a force increasing in the direction of movement, essentially in the weft direction, between two marginal tensioning drums movable independently of each other in a manner such that the different forces that appear when a diagonal distortion occurs, can be compensated in the direction of movement on the tensioning drums so as to remove the distortion.
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FIELD OF THE INVENTION
[0001] The present invention relates to an entertainment device and, more particularly, to a convertible, projected implement/target activity device, where the device includes a projectable implement and a target area and where, in one mode, the projected implement reaching the target area is thereafter contained by the entertainment device and, in a second mode, the projected implement reaching the target area is thereafter directed away from the entertainment device to encourage more active children to pursue and retrieve the projected implement.
BACKGROUND
[0002] Young children enjoy placing or throwing projectiles in defined areas such as holes, hoops or other types of open target areas. Children develop and become more mobile as they explore crawling, walking and other motor skills. At each stage of development, a child will be more agile and capable than in earlier stages of development. Parents want to encourage exploration at each developmental stage in order to assist in passage to the next developmental stage. To this end, reconfigurable entertainment devices offer parents an opportunity to encourage exploration at various developmental levels. Reconfigurable entertainment devices can provide skill level appropriate stimulation at one developmental stage and can then be reconfigured to provide appropriate stimulation at a more advanced skill level/developmental stage.
[0003] In the present case, a reconfigurable childrens' projected implement/target activity device is disclosed. The device can be reconfigured into multiple configurations to stimulate children of different distinct skill and developmental levels. The device includes a graspable projectable implement, a target area and a projected implement movement controller. A child directs the implement through the target area after which the projected implement movement controller controls the movement of the implement. The projected implement can be a ball or any object that a child can grasp easily. The target area can be the open area of a ring, hoop, or other opening, through which the projected implement passes. The target area may be suspended above the projected implement movement controller. The projected implement movement controller may also function as a reversible base for the activity device.
[0004] The projected implement movement controller of the present invention includes a first side and a second side. The first side of the projected implement movement controller has a concave shape and the second side has a convex shape. In a first configuration of the activity device of the present invention, the first side of the projected implement movement controller faces the target area so that a projected implement, passing through the target area, comes in contact with the projected implement movement controller. Because the first side of the projected implement movement controller is concave, when the projected implement passes through the target area, the projected implement is contained in the concave, bowl-shaped, side of the movement controller within proximity of the child. Alternatively, when the reversible projected implement movement controller is reconfigured to expose the movement controller's, second, convex side and the projected implement passes through the target area, the projected implement deflects off of the movement controller's dome-shaped, convex, surface and moves away from the activity device.
[0005] The activity device according to the present invention therefore facilitates two modes of activity for children at different developmental levels. In the first mode where the concave, bowl-shaped, surface of the projected implement movement controller faces the target area, a younger, less mobile, child can place the implements through the target area and the movement controller will corral and contain the implements in close proximity to the child. This first mode also provides a convex surface pointing away from the target area and toward the supporting surface. In the first mode, the convex surface of the projected implement movement controller contacts the supporting surface to allow the activity device to rock back and forth as the child plays. In the second activity mode where the convex, dome-shaped surface of the projected implement controller faces the target area, the projected implements are deflected away from the activity device and must be retrieved as the child plays. This second activity mode therefore encourages children to be more active and further improves their motor skills and hand-eye coordination.
[0006] The activity device of the present invention also provides sensory-stimulating rewards for a child successfully reaching the target area with a projected implement. An optical sensor may be utilized in the target area to sense the presence of the projected implement in the target area. Thus, the presence of the projected implement in the target area may trigger sensory-stimulating output from the activity device. The sensory-stimulating output may include lights, sound effects, speech, and/or music. Thus, a child that successfully reaches the target area with the projected implement is therefore rewarded with sensory-stimulating output to encourage continued play. Additionally, the activity device of the present invention could also incorporate a motion sensor to generate sensory-stimulating output at the slightest touch to further encourage continued play.
SUMMARY
[0007] Generally, the present invention device discloses a children's activity device comprising a projectable implement and a target area at which the implement is to be directed. The activity device includes a sensor that senses when the target area has been successfully reached by the projected implement and a sensory-stimulating output generating device that receives a signal from the sensor. When the sensory-stimulating output generating device receives the success signal from the sensor, it generates sensory-stimulating to encourage continued play. Specifically, the present invention discloses an activity device having a target area for receiving a plurality balls and an electronics unit including a sensor that detects the presence of a ball passing through the target area and a electronics controller that instructs the generation of sensory-stimulating output upon such detection.
[0008] The present invention further contains a reconfigurable projected implement movement controller that directs and controls the movement of the projected implement after the target are has been successfully reached. The projected implement movement controller is reconfigurable in that one side of the projected implement movement controller is convex to direct a projected implement away from the activity device while the opposite side of the movement controller is concave to corral and contain the projected implement within the proximity of the activity device. The projected implement movement controller is connected to the target are such that, relative to the target area, the projected implement movement controller is reversible between the concave and convex sides. When the projected implement movement controller is oriented in the convex arrangement, balls passing through the target area, fall on the movement controller and are directed away from the activity device. Conversely, when the projected implement movement controller is reversed so that the concave side is directed upward, the balls passing through the target area are contained in the movement controller in close proximity to the activity device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a perspective view of a child playing with the activity device of the present invention, with the activity device shown in its containment mode.
[0010] FIG. 2 illustrates an enlarged top perspective view of the concave side of the reversible projected implement movement controller/base of the activity device of FIG. 1 , showing the base split into its two component parts.
[0011] FIG. 3 illustrates an enlarged top perspective view of the convex side of the reversible projected implement movement controller/base of the activity device of FIG. 2 .
[0012] FIG. 4 illustrates an enlarged top perspective view of the concave side of the reversible projected implement movement controller/base of the activity device of FIG. 1 in its assembled form.
[0013] FIG. 5 illustrates an enlarged top perspective view of the convex side of the reversible projected implement movement controller/base of the activity device of FIG. 1 in its assembled form.
[0014] FIG. 6 illustrates an enlarged side perspective view of the reversible projected implement movement controller/base of the activity device of FIG. 1 .
[0015] FIG. 7 illustrates an enlarged side perspective view of the target area and target support arms of the activity device of FIG. 1 .
[0016] FIG. 8 illustrates an enlarged top perspective view of the target area and target support arms of the activity device of FIG. 1 .
[0017] FIG. 9 illustrates a close-up enlarged top perspective view of the target area of the activity device of FIG. 1 .
[0018] FIG. 10 illustrates an enlarged perspective view of the concave side of the reversible projected implement movement controller/base, the target area, and the target support arms of the activity device of FIG. 1 .
[0019] FIG. 11 illustrates manner of connection of the reversible projected implement movement controller/base and the target support arms of the activity device of FIG. 1 during assembly into the deflection mode.
[0020] FIG. 12 illustrates an enlarged perspective view of the connection end of one of the target support arms of the activity device of FIG. 1 .
[0021] FIG. 13 illustrates an enlarged perspective view of one of the support arm reception slots of the reversible projected implement movement controller/base of the activity device of FIG. 1 .
[0022] FIG. 14 illustrates an enlarged perspective view showing the connection end of the support arm received in the guided reception slot of the activity device of FIG. 1 .
[0023] FIG. 15 illustrates an enlarged perspective view of the inner side of one of the support the activity device of FIG. 1 .
[0024] FIG. 16 illustrates an enlarged perspective view of the electrical contacts in another of the reception slots of the reversible projected implement movement controller/base of the activity device of FIG. 1 .
[0025] FIG. 17 illustrates an electronic schematic of the activity device of FIG. 1 in accordance with the present invention.
[0026] FIG. 18 illustrates a perspective view of the activity device of the present invention showing the reversible projected implement movement controller/base holding two projectiles while configured in the containment mode.
[0027] FIG. 19 illustrates an enlarged side perspective view of the activity device of FIG. 1 showing the reversible projected implement movement controller/base configured in the deflection mode.
[0028] FIG. 20 illustrates an enlarged side perspective view of the activity device of FIG. 19 configured in the deflection mode and showing a projectile being deflected away from the activity device.
[0029] Like reference numerals have been used to identify like elements throughout this disclosure.
DETAILED DESCRIPTION
[0030] In accordance with the present invention, an activity entertainment device 100 is disclosed. The activity device 100 is a reconfigurable to allow for two different modes of activity. In a containment mode, the activity device 100 contains or corrals the projected implements that have passed through the target area to accommodate less mobile/younger children. Alternatively, in a second, deflection mode, projected implements that pass through the target area are deflected away from the activity device 100 , requiring the child to retrieve the projected implements and thereby encouraging retrieval activity. In addition, in the containment mode, the portion of the base of the activity device 100 that is in contact with the supporting surface is convex to allow for the rocking of the activity device 100 . In the deflection mode, the portion of the base of the activity device 100 that is in contact with the supporting surface is concave and thus, a stable, non-rocking, characteristic is achieved.
[0031] FIG. 1 illustrates a perspective view of a child playing with the activity device 100 of the present invention, with the activity device 100 shown in its containment mode. As shown, the activity device 100 is a drop/toss toy with a hoop-type target portion 110 that senses a projectile 130 passing through the target portion 110 and generates music to reward the child when a projectile 130 such as a ball is tossed through the target portion 110 . The activity device 100 generally comprises a target portion 110 formed as a hoop or ring, a bowl shaped reversible base 150 for directing the projectile after passing through the target portion 110 , support arms 120 and 140 for supporting the target portion 110 above the reversible base 150 and projectiles 130 . In the containment mode, the reversible base 150 corrals the projectiles 130 that have passed through the target portion 110 . As illustrated, in the containment mode, the convex portion of the reversible base 150 is in contact with the supporting surface 160 to provide a rocking motion for the activity device 100 .
[0032] FIG. 2 illustrates an enlarged top perspective view of the concave side of the reversible projected implement movement controller/base of the activity device of FIG. 1 , showing the base split into its two component parts. In order to reduce the size of the retail packaging (not shown) for the activity device 100 of the present invention, the reversible base 150 is constructed from two separate interlocking portions ( 210 and 240 ).
[0033] Portion 210 includes of a female receptacle 212 . Female receptacle 212 is designed to receive key 246 on portion 240 . Portion 210 also includes a plurality of fastener tabs 214 , 215 , 216 with apertures therein. The fastener tabs 214 , 215 , 216 extend from the side of portion 210 . Portion 240 contains a series of fastener-receiving recesses 341 , 342 , 343 (best seen in FIG. 3 ). Each fastener-receiving recess 341 , 342 , 343 is adapted to mate with a corresponding fastener tab 214 , 215 , 216 on portion 210 and receive a fastener.
[0034] The female receptacle 212 , key 246 , fastener tabs 214 , 215 , 216 , and fastener-receiving recesses 341 , 342 , 343 provide a simple, stable way to secure the portions 210 and 240 of the the reversible base 150 together after removal from the retail packaging (not shown). To secure the portions 210 and 240 together, portion 240 is held above the portion 210 so that fastener tab 214 is aligned with fastener-receiving recess 341 , fastener tab 215 is aligned with fastener-receiving recess 342 , and fastener tab 216 is aligned with fastener-receiving recess 343 . Portion 240 is then lowered so that the corresponding fastener tabs fit snuggly within the corresponding fastener-receiving recesses. The female receptacle 212 and the key 246 will obviously also align and fit snuggly together. Portion 210 can then be secured to the portion 240 by directing fasteners through a apertures in the fastener tabs 214 , 215 , 216 , into the corresponding fastener-receiving recesses 341 , 342 , 343 . The heads of the fasteners may be countersunk into the fastener tabs 214 , 215 , 216 so that they do not protrude above the surface on the convex side 330 of the reversible base 150 .
[0035] As shown in FIGS. 2-5 , the reversible base 150 includes looped members 221 and 222 that form support arm reception slots 231 and 232 for receiving portions of support arms 120 and 140 . As shown in FIG. 2 , the reversible base 150 has a swirl pattern 228 molded into the concave surface of the containment side 220 of the reversible base 150 . Additionally, portion 240 of the reversible base 150 includes an arcuate opening 245 for easy removal of the projectiles 130 from the reversible base 150 during play. FIG. 3 shows a battery compartment door 333 on the convex side 330 of the reversible base 150 . The battery compartment door 333 covers a compartment area where the batteries that power the activity device 100 located. A countersunk fastener secures the door 333 in a closed position so that neither the door 333 or the fastener protrude above the convex side 330 of the reversible base 150 .
[0036] FIGS. 4-6 show the reversible base 150 in its assembled form. FIG. 4 illustrates an enlarged top perspective view of the concave side 220 of the reversible projected implement movement controller/base 150 of the activity device 100 of FIG. 1 in its assembled form. FIG. 5 illustrates an enlarged top perspective view of the convex side 330 of the reversible projected implement movement controller/base 150 of the activity device 100 of FIG. 1 in its assembled form. FIG. 5 also shows a plurality of fastener apertures and fasteners therein to secure the upper and lower portions of the reversible projected implement movement controller/base 150 together. FIG. 6 illustrates an enlarged side perspective view of the reversible projected implement movement controller/base 150 of the activity device 100 of FIG. 1
[0037] FIG. 7 illustrates an enlarged side perspective view of the target portion 110 and target support arms 120 , 140 of the activity device 100 of FIG. 1 . As discussed briefly above, the activity device 100 of the present invention has a hooped or ringed target portion 110 that is supported above the reversible base 150 by support arms 120 and 140 . The upper portion of the hoop is composed of two opaque portions 753 , 754 and two translucent portions 752 , 756 . The target portion 110 houses electronic components that produce light which shines from the translucent upper portions 752 , 756 of the target portion 110 . A fabric net 758 is suspended from the inside of the target portion 110 to create a basketball style activity.
[0038] Support arms 120 and 140 extend from a lower portion 719 of the target portion 110 and extend downward. Support arm 140 includes electronic components (e.g., wiring) associated with power, sound and light. Support arm 140 also houses the power/volume switch 715 on the outside surface of the arm 140 and contains apertures (best seen in FIG. 15 ) through which sound, generated by a speaker passes. The electronic features of the activity device 100 of the present invention will be explained in more detail below.
[0039] Support arm 140 also supports two mechanical activity rollers 711 and 712 . The rollers provide additional entertainment value and are also intended to improve a child's manual dexterity. Both support arms 120 and 140 may include an external raised design that is molded into the arm. In the illustrated embodiment, the raised design is stylized as a serpentine vine with leaves. The lower end of support arms 120 and 140 may be mechanically and electronically connected to the reversible base 150 . Details of the connection of the support arms 120 and 140 to the reversible base 150 will be discussed in more detail below.
[0040] Support arm 120 extends from an upper end that is attached to the lower portion 719 of the target portion 110 down to a lower end that also is connectable to the reversible base 150 . The support arm 120 does not contain any electronic elements and is generally hollow. Stiffening ribs 725 extend along the length and width of the arms 120 and 140 to minimize the amount of material necessary while maintaining the structural rigidity of the arms 120 and 140 . An animal-styled mechanical spinner 721 is supported on the outer side of support arm 120 to perform cartwheels when batted by a child. The spinner 721 is connected to and supported on a projection 727 that is rotatably secured in the support arm 120 . Like support arm 140 , the lower portion of support arm 120 is connectable to the reversible base 150 , which connection will be described below in more detail.
[0041] FIGS. 8 and 9 also illustrate enlarged images of the support arms 120 and 140 as well as the target portion 110 . FIGS. 8 and 9 also show the sensor transmitter 860 . The sensor receiver 862 is located on the opposite side of the target portion 110 from the sensor transmitter 360 . In the illustrated embodiment, the sensor transmitter/receiver 860 , 862 is an optical sensor. A beam of light is directed from the transmitter 860 across the opening 880 in the target portion 110 to the receiver 862 . Obviously, the positions of the sensor's transmitter 860 and receiver 862 can be reversed. When a projectile/implement 130 (see FIG. 1 ) passes through the opening 880 in the target portion 110 , it interrupts the beam of light passing from the transmitter 860 across the opening 880 in the target portion 110 to the receiver 862 which sends a signal to a sensory-output generating device. The sensory-output generating device then generates sensory output to reward the child for placing or tossing the projectile/implement 130 into the opening 880 in the target portion 110 . The operation of the electronic components of the activity device 100 of the present invention will be discussed in more detail below.
[0042] FIG. 10 illustrates an enlarged perspective view of the concave side 220 of the reversible projected implement movement controller/base 150 , the target portion 110 , and the target support arms 120 , 140 of the activity device 100 of FIG. 1 . After assembly of the two portions 210 and 240 of the reversible projected implement movement controller/base 150 , the basic assembly of the activity device 100 is complete. Disassembling the activity device 100 and reassembling the activity device 100 between the containment mode and the deflection mode requires only reversing the base 150 which does not require the use of any fasteners or tools. Thus, reconfiguration between the containment mode and the deflection mode amounts to not much more than a plug-in/plug-out type of exercise. FIG. 10 shows the assembled base 150 of the activity device 100 device ready to be assembled into either the containment mode or the deflection mode. Specifically, when the base 150 of the activity device 100 is assembled in the orientation shown in FIG. 10 , the result is a completely assembled activity device 100 in the containment mode in which projectiles/implements 130 are collected in the concave side 220 of the base 150 after passing through the target portion 110 .
[0043] FIG. 11 illustrates manner of connection of the reversible projected implement movement controller/base 150 and the target support arms 120 , 140 of the activity device 100 of FIG. 1 during assembly into the deflection mode. Specifically, when the activity device 100 is assembled in the orientation shown in FIG. 11 , the result is a fully assembled activity device 100 in the deflection mode. To assemble the activity device 100 in the deflection mode, the lower connection ends 1114 , 1124 of the support arms 140 , 120 are vertically aligned with their corresponding support arm reception slots 231 and 232 in the base 150 . The connection ends 1114 , 1124 are lowered and slid into and received by the support arm reception slots 231 , 232 . The connection ends 1114 , 1124 slide into the support arm reception slots 231 , 232 until they reach end stops 1113 and 1123 .
[0044] The connection between the support arms 120 , 140 and the reversible base 150 will now be described in detail along with FIGS. 12-14 . Because support arm 140 contains electronic components and support arm 120 does not, the support arms are not interchangeable within the support arm reception slots 231 and 232 in the base 150 . In other words, connection ends 1114 must be received into reception slot 231 and connection end 1124 must be received into reception slot 232 . To ensure that connection ends 1114 and 1124 are received only in the correct reception slots and to insure reception into the reception slots 231 and 232 with precise alignment, the connection end 1124 of the support arm 120 has guide members 1224 .
[0045] Guide member 124 (shown in FIG. 12 ) is a groove in the outwardly facing surface of the connection end 1124 of support arm 120 . As shown in FIG. 13 , complementarily guide member 1326 is a longitudinal projection on the inside of looped member 222 projecting into reception slot 232 towards the center of the activity device 100 . FIG. 14 shows connection end 1124 of support arm 120 partially inserted into reception slot 232 of the looped member 222 . During insertion, guide member 1326 of the looped member 222 slides within grooved member 1224 of the connection end 1124 of support arm 120 to ensure proper alignment between the connection end 1124 and the reception slot 232 . The connection end 1124 slides easily into the reception slot 232 until end stop 1123 prevents further insertion.
[0046] FIGS. 15 and 16 illustrate how electrical contact is maintained between the portion of the electronic system within the reversible base 150 and the remainder of the electrical system within the support arm 140 and the target portion 110 . FIG. 15 also illustrates a hole pattern 1510 on the inner surface of support arm 140 . Hole pattern 1510 covers a sound producing speaker. The connection end 1114 of support arm 140 contains an inside electrical contact 1516 and an electrical projection contact 1517 both on the inside surface of the connection end 1114 of support arm 140 . Contacts 1516 and 1517 conduct electrical current between the reversible base 150 and the target portion 110 . Correspondingly and as illustrated in FIG. 16 , the inside surface of the reception slot 231 has three reception electrical contacts 1610 , 1611 , and 1612 for receiving the inside electrical contact 1516 and the outside electrical contact 1517 . The inside 1516 and outside 1617 electrical contacts are spring loaded so that they retract into the inner surface of the connector end 1114 when the connector end 1114 is being inserted into the reception slot 231 . This retraction prevents the electrical contacts 1516 , 1517 from becoming an obstacle to insertion of the connection end 1114 into 231 .
[0047] The electronics assembly of the activity device 100 of the present invention can also identify the orientation of the reversible base 150 and thus the mode (containment or deflection) in which the activity device 100 is operating. Appropriate sensory-stimulating output can then be generated depending on the mode in which the activity device 100 is operating. Specifically, the activity device 100 can determine the mode because the inner electrical contact 1516 is always aligned with the central reception electrical contact 1611 . However, the outside electrical contact 1517 is aligned with one of the outer reception electrical contacts 1610 in the containment mode and the other of the outside outer reception electrical contacts 1612 in the deflection mode when the base 150 is reversed. The orientation of the reversible base 150 may therefore be determined by detecting which of the outer reception electrical contacts 1610 or 1612 receives the outer electrical contact 1517 . Again, these electrical contacts 1516 , 1517 , and 1610 - 1612 allow power and electrical signals to be passed between the power source and the electronics controller (housed in the base 150 ) to the speaker, lights, and receiver/transmitter (all of which are located in the support arms 120 , 140 and the target portion 110 ) without the use of wires extending out of the base 150 .
[0048] As discussed above, the activity device 100 of the present invention may include one or more electronic components. FIG. 17 illustrates an electronic schematic of the activity device 100 of FIG. 1 in accordance with the present invention. In the illustrated embodiment, the electronics assembly 1700 includes an optical sensor 1710 . Specifically, the sensor of the electronics assembly 1700 includes an LED emitter (light emitting portion/transmitter) 860 and a corresponding photoconductive receiver (light receiving portion) 862 (e.g., where the light emitting portion and the light receiving portion makes up a “sensor pair”). The electronics assembly 1700 also includes two lights generators 1750 , 1752 . The light generators 1750 , 1752 generally flash to the beat of the music. Light generators 1750 , 1752 are housed beneath the two translucent portions 752 , 756 of the target portion 110 . The flashing lights 1750 , 1752 act as a reward for various encouraged behavior. As discussed below, a number of events trigger a light display response in a number of different modes. The electronics assembly 1700 may further include a speaker 1760 coupled to both a microprocessor/electronics controller 1780 and the power source 1770 .
[0049] The electronics assembly 1700 further includes three switches, each switch being associated with a particular feature of the activity device 100 . Switch 1720 A, 1720 B is responsible for controlling power and volume options (switch 1720 A and 1720 B are simply illustrated as two poles of a single switch). Switch 1720 A, 1720 B may be used to control the connection of a power source 1770 to the electronics assembly 1700 (turning it on and off). The power source 1770 may include, for example, three “AAA” batteries. The schematic of FIG. 17 shows electrical contacts 1 , 2 and 4 separate from contacts 8 , 7 and 5 , however, these contacts all belong to the same switch and are all controlled by power/volume (illustrated as switch 715 in FIG. 7 ). Therefore, when switch 1720 A, 1720 B is in position ( 1 , 8 ), no battery power is available to the controller 1780 . In position ( 2 , 7 ), the battery power is available to the controller 1780 and a low sound is generated by the speaker 1760 . Finally, in position ( 4 , 5 ), power is available to the circuit and full sound is generated by the speaker 1760 . When engaged in either of the second or third positions (“low”, “high”), the switch 1720 A, 1720 B communicates with the microprocessor 1780 , and switch-specific sensory output (sounds and/or lights) is generated.
[0050] A second internal switch 1730 may be included for additional functionality (such as a motion sensor housed within base 150 ). After the first switch 1720 A, 1720 B is activated, and power is available to the circuit, the controller unit 1780 illuminates lights 1750 and sounds before transferring to a sleep mode. The controller unit 1780 enters a sleep mode in which any further movement triggers lights and sounds. A third switch 1740 may be used to activate a “Try-Me” mode. The microprocessor controller unit 1780 has the “Try-Me” mode that can be activated when the product is still in the package on the retailer's shelf. In other words the shopper can activate the microprocessor unit 1780 to initiate a limited sample of the sounds and lights that would be generated in normal modes. When the packaging is removed the “Try-Me” mode may be disabled.
[0051] As noted above, each of the speaker 1760 , the power source 1770 , the light emitter 860 the light receiver 862 , the switches 1720 A-B, 1730 , 1740 , and the lights 750 are operatively coupled (connected) to the microprocessor unit 1780 . The type of microprocessor is not limited, and includes microcontrollers, microprocessors, and other integrated circuits. Microprocessor unit 1780 recognizes and controls signals generated by and to the light emitter 860 , the light receiver 862 , the various switches 1720 A-B, 1730 , 1740 , and the lights 750 . In addition, microprocessor unit 1780 generates and controls operational output. The microprocessor unit 1780 continually monitors the electronic status of the light emitter 860 , the light receiver 862 and the switches 1720 A-B, 1730 , and 1740 , generating and altering the sensory output (e.g., sounds and/or lights) accordingly.
[0052] The operation of the activity device 100 will now be described. In operation, when the first switch 715 (internally, switch 715 is schematically illustrated as switch 1720 A-B) is engaged, power is sent from the power source 1770 to the microprocessor unit 1780 . Once powered and active, the microprocessor unit 1780 of the activity device 100 is in the start-up mode. In the start up mode, the microprocessor unit 1780 activates lights from the light sources 1750 and sounds from the speaker 1760 for a predetermined period of time. The microprocessor unit 1780 then changes to beam break mode. In beam break mode, the emitter 860 and the receiver 862 of the sensor 1710 in the target portion 110 is activated. If a ball/implement 130 passing through the target portion 110 breaks the beam, the microprocessor unit 1780 activates sounds through speaker 1760 and lights 1750 blink to the music. If the beam is not broken for a predetermined period of time (e.g., one minute), the microprocessor unit 1780 goes into “sleep” mode. In sleep mode, the beam break feature is turned off and the internal motion sensor 1730 feature (if present) may be activated. Whenever the activity device 100 is disturbed to activate motion sensor 1730 , the microprocessor unit 1780 goes back to the start-up mode, generates sounds and flashing coordinated lights for a period of time, turns the beam break feature on and waits for the beam sensor 1710 to be broken by a ball/implement 130 .
[0053] FIGS. 18-21 show the fully assembled activity device 100 in its various modes. FIG. 18 shows the activity device 100 in its containment mode with two balls/implements 130 that have passed through the target portion 110 and been contained in the concave surface 220 reversible base 150 . As a child puts the balls/implements 130 through the target portion 110 , the sensor beam is broken to activate sounds and lights before the balls/implements 130 are contained in the concave surface 220 reversible base 150 . In this mode, the activity device 100 also rocks back and forth on the convex outer surface 330 of the reversible base 150 .
[0054] FIGS. 19-20 show the activity device 100 in the fully assembled deflection mode. In this deflection mode the convex surface 330 of the reversible base 150 faces the target portion 110 . The portion of the reversible base 150 contacting the supporting surface 160 is stable and thus, the activity device does not rock in the deflection mode. When balls/implements 130 pass through the target portion 110 and break the sensor beam, the microprocessor unit 1780 generates lights and sounds. The balls/implements 130 then drop onto the convex surface 330 of the reversible base 150 and are deflected away from the activity device 100 . The child can then chase and retrieve the balls/implements 130 before placing them in the target portion 110 again. FIG. 20 shows a ball/implement 130 in multiple positions as the ball contacts the convex surface 330 of the reversible base 150 and is directed away from the activity device 100 .
[0055] The electronics assembly 1700 in accordance with the present invention may include any combination of sensors, switches, lights, speakers, animated members, motors, and sensory output generating devices. The microprocessor unit 1780 may produce any combination of audio and visual effects including, but not limited to, animation, lights, and sound (music, speech, and sound effects). The output pattern is not limited to that which is discussed herein and includes any pattern of music, lights, and/or sound effects. The electronics assembly 1700 may also include additional switches or sensors to provide additional sensory output activation without departing from the scope of the present invention.
[0056] Thus, it is intended that the present invention cover the modifications and variations of this invention that come within the scope of the appended claims and their equivalents. For example, it is to be understood that terms such as “left”, “right” “top”, “bottom”, “front”, “rear”, “side”, “height”, “length”, “width”, “upper”, “lower”, “interior”, “exterior”, “inner”, “outer” and the like as may be used herein, merely describe points of reference and do not limit the present invention to any particular orientation or configuration.
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A reconfigurable target/projectile activity entertainment device is disclosed, wherein the device includes a projectile, a target having a target area and a reversible base connectable to the target. The target is in the form of a hoop or ring and is disposed above the reversible base. The hoop has an opening therein that forms the target area. The hoop contains a sensor that detects a projectile passing through the target area and communicates with a sensory generator to generate sensory-stimulating output (i.e., lights and sounds). Projectiles directed through the target area drop to the reversible base below the target area. The reversible base has a first side and a second side. The first side is concave for collecting a projectile that drops thereon. The second side is opposite the first side and has a convex side that deflects projectiles dropping thereon to deflect the projectile away from the device. The reversible base can be reconfigured between a first mode wherein the concave side faces the target area and a second mode that wherein the convex side faces the target.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of a prior U.S. Provisional Application No. 60/539,718, filed Jan. 29, 2004. The entire teachings of the above application(s) are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The general field of this invention relates to the controlling of motors for accurate discrete remote positioning control throughout the range of a mechanical mechanism.
[0003] There are many production processes that require frequent adjustments by an operator at the beginning of each new job and during the running of the job. In many instances the adjusting mechanisms are located remotely, requiring the operator to climb a latter or walk a good distance each time an adjustment is necessary.
[0004] A good example of such an application is in the printing of newspapers. With the advent of four color process printing, which virtually every newspaper offers today, a popular printing machine called a printing tower has emerged as the chosen printing press configuration. The printing tower consists of two four color printing units arranged vertically so that the four process colors (yellow, magenta, cyan and black) are printed simultaneously on each side of the paper. Each printing unit employs two mechanical mechanisms with hand wheels that are used to make adjustments in registration of each color to the other colors. One hand wheel is used for adjustment in the lateral register, in the X direction, while the other mechanical mechanism provides adjustment in the circumferential register, in the Y direction. Thus a tower has a total of 16 mechanical mechanisms that the operator must manually adjust to make corrections in lateral and circumferential registration of the eight colors that are printed on both sides of the paper.
[0005] The tower configuration is considered to be superior, as it requires minimal floor space which is ideal for crowded press rooms, the vertical configuration requires the operator to climb a ladder to reach some of the mechanical mechanisms each time he needs to make an adjustment.
[0006] Electric motors have been installed on some of these towers with the intent of providing the operator with remote control capability thus making register adjustments much easier.
[0007] In those instances where motors have been added to existing mechanisms a number of deficiencies have still arisen that greatly inhibit the success of motorization due to the great frustration of operation personal when using the motor as a means of introducing register correction as opposed to using the hand wheel.
[0008] Some of these deficiencies are related all can be eliminated with the teachings of this disclosure.
[0009] The standard method for replacing the hand wheels with a motor includes two operator push buttons, one applying voltage to the motor when depressed by the operator driving the motor in one direction, with the other switch when depressed by the operator driving the motor in the opposite direction. Thus the amount of correction introduced depends upon the direction of correction and for how long the operator depressed the switch. The resolution or minimum correction introduced is limited to the minimum time that the operator could depress the switch which is about one third of a second. There has always been the problem that the maximum slew speed is limited to the resolution required to achieve the accuracy that was desired. Typically a 0.005 inch resolution would yield a slew speed of about 1 inch per minute. If the application was on a full range mechanism requiring moving the mechanism 20 inches for different jobs, than it would take 20 minutes or more to reposition the mechanism. For many applications it is not acceptable to require a two motor system where one motor would be used for obtaining the resolution and another motor used to provide a fast slew speed.
[0010] The teaching of this application includes a means of increasing the maximum rate of correction significantly as required while simultaneously increasing the resolution.
[0011] Other deficiencies have arisen when replacing the hand wheel. For example, when using the hand wheel the operator can automatically compensate for backlash in the mechanism when making an adjustment. As he turns the hand wheel to make an adjustment, he can feel the lesser pressure required when moving through the backlash and would always move through the backlash and then make his correction when he felt the higher pressure required to move the mechanism. When moving the mechanism using the electric motors, there was no way to sense backlash with several repeated adjustment required to get through the backlash before an actual correction was made. The lack of backlash compensation using the motors caused great difficulty in accurate positioning and significant frustration for the operator.
[0012] Hand wheels also have a visual centering means that allows the operator to center each mechanism before starting a new job to make sure that the full range of the mechanism was available if needed to compensate for register errors. Motors have no similar natural centering means with the result that frequently one or more mechanisms would run to a limit stop, requiring a great deal of waste in manually moving all four colors to provide for more range on the unit that ran to the stop.
[0013] When using the hand wheel in making a correction, the operator could make an exact and repeatable adjustment in either direction which is not possible when using the motor in the face of backlash.
[0014] Until now the only means of overcoming these limitations when using motors for remote positioning of registration has been to add feedback from the printed image using an automatic register control. The automatic register control would eventually correct for any error including when moving through the backlash by making a number of corrections. However automatic register controls have a number of major disadvantages including very high cost, complexity, the need for significant operator training and the difficulty of locating the printed marks that must be included in the art work for the system to operate.
[0015] This patent relates to a method to overcome all of these disadvantages and addition provides a low cost alternative to automatic register controls.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Prior art motor positioning has been limited to either stepper motors in an open or closed loop configuration and other motor types in a closed loop configuration using encoder or potentiometer feedback.
[0017] 1. Stepper Motor Control:
[0018] Stepper motors are motors that advance a specific amount for each power pulse applied to the windings of the motor. They are highly susceptible to inaccurate counting in applications where high friction and inertial loads are encountered and thus in these applications an encoder is usually employed. Due to the added complexity of power circuitry and its added cost with additional maintenance and cooling requirements, stepper motors are rarely used in all but the lowest power applications with little friction and constant low inertia applications.
[0019] 2. Closed Loop Potentiometer Feedback:
[0020] This method is the most common method of feedback position control currently in use on existing machines. The output of a potentiometer, (variable resistance ratio device) usually ten turns, is connected through a suitable gear ratio so that the range of the potentiometer covers the entire range of the mechanical mechanism. The position of the potentiometer slider corresponds to the position of the mechanical mechanism with the voltage ratio of the slider voltage to the excitation voltage representing an analogue of the position of the mechanical mechanism.
[0021] 3. Closed Loop Encoder Feedback.
[0022] This method substitutes an encoder (usually an optical encoder) for the potentiometer as described above. Digital pulses are generated directly by the optical encoder and when accumulated in a counter represents the position of the mechanical mechanism. While this method can be more accurate than the potentiometer, it requires significant additional complexity and unacceptable costs for most position control applications in view of this disclosure.
[0023] In general all of the above methods of position control are limited and suffer from the following disadvantages:
[0024] 1. For applications requiring power (⅛ HP plus or minus) because of high friction or inertial loading all of the above methods of position control are cost prohibitive.
[0025] 2. All of the above methods of position control require detailed engineering analysis for each application with little leeway in providing stable operation with variations in friction and inertial loading.
[0026] 3. All of the above methods of position control have limited selection of available gearbox motor combinations and require engineering design for each application to incorporate limit switches which prevent damage to the mechanical mechanisms.
[0027] 4. All of the above methods of position control require individual selection of all of the parts or assemblies associated with the application from numerous sources. This includes motor, gearbox, limit switches power amplifiers.
[0028] A variety of different motor types have been installed on formerly manually controlled mechanisms to provide remote activation without the need of the operator to leave his operating station to make corrections. The most common types of motors used for this purpose have been either 2 or 3 phase motors. The most common motor that has been used for this purpose for many years is the 2 phase synchronous motor and specifically the line of synchronous motors manufactured by the Superior Electric Co. under the trade name of SLO SYN. The advantage of the SLO SYN motor over other motor types is its high reliability, and its simplicity of electrical and mechanical interconnections.
[0029] The ability of the SLO SYN motor to start and stop within 0.025 seconds eliminates the need for a brake to prevent overrunning or coasting as is required in 3 phase motors when accurate positioning using this invention is desired.
[0030] Although the SLO SYN motor is ideal and provides the most accurate positioning for very large distances, it has a number of disadvantages that make it unsuitable for many applications where high inertia and friction loads are encountered and where higher resolutions and slew rates are required. Where high inertial and friction loads are encountered or where higher resolutions and slew speeds are desired, the 2 or 3 phase AC Induction Motors like those manufactured by Oriental Motor Co. of Japan are better suited using this invention.
[0031] Thus a major advantage of this invention is the ability to use many different motor types to provide for a variety of different applications.
[0032] In applications where former manually positioned mechanisms have been motorized to make it easier for the operator to make manual corrections, serious operational deficiencies have been encountered that have limited the success of this cost effective method for reducing the physical demands on operating personnel.
SUMMARY OF THE INVENTION
[0033] Among the objectives of this invention is to overcome these deficiencies and provide the following benefits:
1. Provide a means for greatly increasing the resolution or smallest magnitude of correction that can be introduced by a motorized mechanical mechanism while at the same time increasing the maximum rate of correction that can be introduced. 2. Provide the means for controlling an AC motor to make repeatable discrete positional changes in either direction on any mechanical mechanism on which a motor can be installed and without the use of an encoder or any other conventional feedback device. 3. Provide a means for controlling an AC motor to make repeatable discrete positional changes in either direction for any mechanical mechanism where a motor can be installed independent of any amount of backlash or loss motion in the mechanism or in the coupling between the motor and mechanical input to the mechanism. 4. Provide for automatic centering for each motorized mechanism that can be actuated at the beginning of each job to prevent running into mechanical stops. 5. Provide 1 through 4 to control single or multiple motors simultaneously. 6. Provide the utmost in simplicity to minimize the cost of installation and the need for operator training.
[0040] The following list details some of the advantages possible in some of the preferred embodiments of the present invention:
[0041] 1. By controlling motor activation time electronically, significantly higher and significantly consistent resolutions and slew rates can be achieved.
[0042] 2. The present invention provides the capability of using low cost AC induction motors with far greater tolerance of friction and inertial loads, greater flexibility and selection of motor power and gearbox ratios.
[0043] 3. Accurate and repeatable position changes are made each time a switch is first pressed and then released. The time interval for correction is set in integers 120 cycles per second.
[0044] 4. The low pass filter inherent in the AC induction motor due to armature inertia provides automatic gain reduction with time thus providing a much greater dynamic range with increased accuracy and speed of response over synchronous motors.
[0045] 6. Repeatable positional changes can be made in both directions that are far smaller than the backlash or loss motion in the mechanism.
[0046] 7. The complete elimination of any feedback device such as an encoder or potentiometer makes for a greatly simplified and less costly installation.
[0047] Briefly, the present invention is a method and means of providing a significant increase in resolution and slew rates, repeatable discrete incremental position control with automatic positioning or centering of the mechanism anywhere within its range. These advantages are provided in the face of any degree of loss motion or backlash inherent in the mechanism due to design limitations, wear or poor maintenance.
[0048] While any motor type can be used with this invention, AC synchronous and AC induction motors are the preferred motor type each providing additional unique capabilities as will be revealed.
[0049] Installation and application requirements are much simpler as no conventional encoder or feedback device is required thus greatly reducing the costs and simplifying the installation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0051] FIG. 1 is a block diagram of the system.
[0052] FIG. 2 is a motor schematic showing limit switches.
[0053] FIG. 3 illustrates an operator control panel.
[0054] FIG. 4 is an electrical schematic counter circuitry.
[0055] FIG. 5 is an electrical schematic of the incremental, backlash and centering state machines.
[0056] FIG. 6 is a schematic of the operator interface logic.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0057] A multiple motor controller consists of a number of components connected as stated below.
[0058] FIG. 1 is an overall block diagram of the interconnections of the system components that provide for simultaneous control of up to eight motors according to this disclosure. As each motor performs in the same manner the connections for one motor 104 will be described.
[0059] Motor 104 of FIG. 1 is better described from the enlarged view as shown in FIG. 2 .
[0060] Motor 200 of FIG. 2 can be any motor however, the two phase reversible induction motors manufactured by the Oriental Motor Company of Japan are preferred. Motor 200 is restricted in its travel in both directions via adjustable limit switches 201 and 202 . That is, when the motor runs in one direction it will eventually open either limit switch 201 or 202 to stop the motor before it jams up or causes damage to the mechanism. In addition to stopping the motor before it reaches the end of its travel, the limit switches also provide a basis for timing the motor to center it or position it to a specific position as will be discussed.
[0061] In referring back to FIG. 1 , motor 104 is connected to interconnection panel 102 through connector 103 . Phase shift capacitor 101 is also connected to Motor 104 through conector 103 .
[0062] Motor 104 connections are routed through connector 105 and connected to solid state relay 106 . Solid state relays 106 and 107 plus computer 108 provide dor bidirection control of four motors. Relays 106 and 107 are manufactured by OPTOo22 as their Model G4PB4R.
[0063] Operator Panel 109 connects directly to computer 108 which provides the signals that are conditioned on computer 108 providing the advantages as described in this disclosure.
[0064] FIG. 3 is a drawing of the operator control panel 109 of FIG. 1 . The top four sets of operator control buttons are arranged vertically as they control the circumferential register where the lower sets of four control buttons are arranged horizontally as they control the lateral register, however the connections are the same for both functions. Thus only the right hand control buttons will be described.
[0065] 303 represents a toggle switch which, when toggled in one direction, will directly activate the motor in one direction, and when toggled in the opposite direction will directly activate the motor in the opposite direction. This provides a very fast slew speed of the motor and is used only for initial setup or if large errors are present at startup.
[0066] 302 and 304 are simple push buttons which when depressed will close a contact. One switch 302 closes a contact in the advance direction while the second switch 304 closes the contact in the retard direction.
[0067] 301 and 305 are neon lamps that will light up when the motor is running or when it runs into a stop opening the limit switch contact 202 or 201 of FIG. 2 .
[0068] Push button 306 initiates the automatic centering function as will be described.
[0069] In operation, the operator depresses an advance or retard push button 302 or 304 on Operator Control Panel 109 of FIG. 1 which sends a signal to circuit board 108 of FIG. 1 that conditions the signal, which then goes to solid state relay 106 of FIG. 1 , that then activates the respective motor in the desired direction according to the instructions that come from circuit board 108 .
[0070] FIGS. 4, 5 , and 6 are detailed schematics of circuitry that together with the components already described provide the features that are the subject of this invention.
[0071] Specifically FIG. 4 illustrates details of the counter circuitry that provides the timing to implement the features of incremental discrete correction, automatic backlash and centering. FIG. 5 defines the state machines that provide these features, and FIG. 6 defines the interface circuitry between the operator input and the resulting motor operation.
[0072] 401 and 402 of FIG. 4 are 8 bit bidirectional binary counters connected as a single 16 bit counter. They are commercially available chips manufactured by Fairchild Semiconductor of Portland, Me. their product number 74F269. The 74F269 chips have an eight bit preset which is connected by a bus to chips 403 through 407 , which are Octal Bidirectional transceivers with 3 state outputs also manufactured by Fairchild Semiconductor as their product number 74F245. 8 bit binary switches 409 through 417 are connected to the inputs of transceivers 403 through 407 respectively. Eight bit pull up resisters 408 through 416 are also connected to the 8 bit binary switches 409 through 417 respectively and provide current for a binary 1 value.
[0073] Counters 401 and 402 count clock pulses 426 and 422 , respectively these clock pulses can be generated from a number of sources but in this emodiment a Fairchild Semiconductor chip H11A817 which is 501 of FIG. 5 is used because of its simplicity and low cost. This chip is an optically coupled device that will generate 120 cycles per second (cps) from a 60 cps voltage source. Item 502 of FIG. 5 represents the 120 cycle clock source, and item 503 of FIG. 5 processes this frequency through a flip flop to provide a 60 cps clock source. The 120 cps clock source represent pulses that are 1/120 or 0.0083 seconds in duration.
[0074] As each set of binary switches, pull up resisters, and octal transceiver in FIG. 4 function in the same manner only the set consisting of 409 , 408 , 403 , 419 , 420 , and 421 will be described now in detail.
[0075] A binary number from 1 to 16 bits long is selected in binary switches 409 and 421 . This number represents the number of 0.0083 clock time periods that the counters will be preset to, after which the counters will then count down to zero, providing a time interval equal to the present number times of 0.0083 second pulse intervals.
INCREMENTAL ADVANCE CORRECTION
[0076] This action is triggered when the operator presses an advance push button 301 of FIG. 3 , which is connected to one of the four advance flip flops (FFs) 601 , 612 , 614 , and 616 of FIG. 6 . For this discussion, consider that FF 601 is connected to push button 301 . This initiates the following sequences:
[0077] The Q output of flip flop 601 of FIG. 6 is set to a 1.
[0078] The output of gate 504 through gate 505 clocks FF 506 , setting its Q output high.
[0079] After 2 Clk pulses the Q output of FF 507 goes high and with the still high notQ of 508 provides a notA at the output of gate 511 .
[0080] This notA pulse goes to 414 and 415 loading the contents of binary switches 409 and 412 in to counters 401 and 402 . On the next clock cycle, the contents of binary switches 409 and 412 are clocked into the counters when the output of gate 513 , PE goes low.
[0081] This starts counters 401 and 402 to count down and when they reach zero output pulse 418 , notTC is asserted.
[0082] TC clocks FF 509 complete the time interval represented by the output of FF 508 TG 3 .
[0083] After two clock cycles, the original FF 601 of FIG. 6 that started the action is reset through the clear 602 signalof FIG. 6 .
[0084] During the time interval TG 3 which is an input to 603 , an output signal is generated through gates 604 and 605 which activates an optically isolated relay running the motor at full speed during the time interval TG 3 .
BACKLASH CONSIDERATIONS
[0085] In the advanced direction the motor is always run in the same direction so that the backlash is always loaded out in one direction. However in the retard direction the motor is first reversed for a total increment that equals an amount equal or greater than the amount of backlash defined here as (XBL) plus the amount of correction desired, called CD, and then advanced an amount equal to XBL. In this manner the mechanism is automatically loaded out in the retard direction thus providing the finest resolution independent of the magnitude of the backlash or wear in the mechanism.
INCREMENTAL RETARD CORRECTION
[0086] The action is triggered when the operator presses a retard push button 304 of FIG. 3 which is connected to one of the four retard FF's 607 , 613 , 615 , and 617 of FIG. 6 . For this discussion consider that FF 607 is connected to push button 304 . This initiates the following sequences:
[0087] The Q output of flip flop 607 of FIG. 6 is set to 1.
[0088] The output of gate 526 through gate 514 clocks FF 516 setting Q high.
[0089] After 2 Clk pulses the Q output of FF 517 goes high and with the still high notQ of 518 provides a notBR at the output of gate 524 .
[0090] This notBA pulse goes to 427 and 428 loading the contents of binary switches 411 and 434 in to counters 401 and 402 . On the next clock cycle the contents of binary switches 411 and 412 are clocked into the counters when the output of gate 513 , PE goes low.
[0091] This starts counters 401 and 434 to count down and when they reach zero output pulse 418 notTC is generated.
[0092] TC clocks FF 519 completing the time interval represented by the output of gate 525 TG 1 . Note this is the time interval for which the motor is reversed equivalent in time to both the amount of backlash and correction desired.
[0093] During the time interval TG 1 which is an input to 608 , an output signal is generated through gates 610 and 611 which activates an optically isolated relay running the motor at full speed in the retard direction during the time interval TG 1 .
[0094] When FF 519 is clocked by TG, it starts an 8 clock delay through FF 520 and counter 527 . During this delay time the motor will automatically come to a stop before a reverse voltage is applied to advance the motor. This provides a softer transition from full speed in one direction to full reverse voltage in the opposite direction.
[0095] At the end of the delay FF 520 through gate 523 loads the contents of binary switches 413 and 435 into counters 401 and 402 through pins 429 and 430 of octal bidirectional transceivers 405 and 439 respectively. At the same time the contents of binary switches 413 and 435 are loaded into the counters through gates 512 and 513 .
[0096] This starts counters 401 and 402 counting down to zero and when zero is reached the signal TC clocks FF 521 producing the time interval 526 TG 2 .
[0097] Time interval TG 2 goes to gate 609 and trough gates 605 and 606 run the motor in the advance direction for the interval TG 2 . 526 The remaining 9 FF's shown at the bottom of FIG. 5 provide for automatic centering of the mechanism. However it functions in the same manner as the Retard correction and thus will not be described.
COMMENTS AND CONCLUSIONS
[0098] The previous detailed description of the method for providing exact incremental correction to a motor has a number of unique application advantages.
[0099] 1. The resolution of the motor (minimum correction) can be any value depending upon the clock frequency selected and capability of the motor. In this disclosure the clock frequency is selected as 0.0083 seconds which allows the motor to be actuated for a minimum time of 0.0083 seconds.
[0100] Typically an operator can manually actuate a switch in a minimum time of about 0.33 seconds. Thus a considerable improvement in resolution is possible allowing a significant increase in slew speed for those applications where frequent large excursions in compensating mechanisms are required in setting up new jobs.
[0101] 2. The ability to provide exact and repeatable corrections in either direction enable the ability to provide the same resolution in the face of any degree of backlash or wear in the mechanism.
[0102] A single 16 bit counter enables intervals of from 1 to 65,536 clock pulses. With a clock period of 0.0083 seconds, the total time intervals can be set from 0.0083 seconds to 9.102 minutes (65,536×0.0083).
[0103] In the application of motorizing previously manually controlled hand-wheels, the time intervals for both the advance and retard directions can be pre set very accurately by knowing the following information most of,which is obtained by direct measurement.
[0104] A. The minimum correction desired. Example: 0.005 inch in both the advance and retard direction.
[0105] B. Maximum correction in one revolution of the hand-wheel. Example: 0.1 inch.
[0106] C. Maximum rate of motor correction. Example: 1″/minute.
[0107] D. Amount of loss motion when reversing direction. Example: 20 degrees.
[0108] Calculate from the above as follows
[0109] Correction/Second=0.016″/sec.
[0110] Correction time for Advance-Retard 0.005″=0.31 sec.
[0111] Correction time for loss motion 20/360×6=0.33 sec.
[0112] This one can set the binary switches as follows:
[0113] Enter into Advance Binary Switch 409 of FIG. 4 binary number 37 (0.31/0.0083) equal to LS 10100100.
[0114] Enter into Retard Binary Switch 411 of FIG. 4 binary number 77 (0.31+0.33)/0.0083 equal to LS 10110010.
[0115] Enter into Retard-Advance Binary Switch 413 of FIG. 4 binary number 39 (0.33/0.0083) equal to LS 11100100.
[0116] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
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A controller for motor activation providing accurate and repeatable position changes by pressing and releasing a push button switch. Repeatable position changes are made in an advance direction by triggering a digital counter for a predetermined number of cycles of a reference clock signal. Backlash in retard motion of the motor is reduced by similarly asserting a retard motor input for an amount of time determined by another digital counter with a following advance correction made automatically after the retard signal is applied, by applying a predetermined retard-advance movement amount, as again counted by a digital counter. The advance binary amount, the retard binary amount and the retard-advance binary amount of set through binary switch inputs to respective counters to count the respective time periods (TG 3 , TG 1 , and TG 2 ).
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/599,690 filed Feb. 16, 2012, the entirety of which is incorporated by reference light generating devices Application claims priority of Taiwan Patent Application No. 101139410, filed on Oct. 25, 2012, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a cleaning robot, and more particularly, to a cleaning robot with a non-omnidirectional light detector.
[0004] 2. Description of the Related Art
[0005] A variety of movable robots, which generally include a driving means, a sensor and a travel controller, and perform many useful functions while autonomously operating, have been developed. For example, a cleaning robot for the home, is a cleaning device that sucks dust and dirt from the floor of a room while autonomously moving around the room without user manipulation.
BRIEF SUMMARY OF THE INVENTION
[0006] An embodiment of the invention provides a control method of a cleaning robot. The method comprises steps of moving the cleaning robot according to a first direction; keeping moving the cleaning robot according to the first direction when a light detector of the cleaning robot detects a light beam; moving the cleaning robot for a predetermined distance and then stopping the cleaning robot when the light detector does not detect the light beam; and moving the cleaning robot in a second direction.
[0007] Another embodiment of the invention provides a cleaning robot comprising a controller and a light detector. The controller controls the cleaning robot to move in a first direction. The light detector is coupled to the controller and detects a light beam. When detecting the light beam output by a light generating device, the light detector transmits a first trigger signal to the controller. When the light detector does not detect the light beam, the light detector transmits a second trigger signal to the controller. The controller controls the cleaning robot to stop after moving a distance and leaves a restricted area labeled by the light beam in a second direction.
[0008] A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
[0010] FIG. 1 is a schematic diagram of a light generating device and a cleaning robot according to an embodiment of the invention.
[0011] FIG. 2 a is a top view of an embodiment of a non-omnidirectional light detector according to the invention.
[0012] FIG. 2 b is a flat view of the non-omnidirectional light detector of FIG. 2 a.
[0013] FIGS. 2 c and 2 d are schematic diagrams for estimating an incident angle of a light beam by using the proposed non-omnidirectional light detector according to the invention.
[0014] FIG. 2 e is a schematic diagram of another embodiment of a non-omnidirectional light detector according to the invention.
[0015] FIG. 3 a and FIG. 3 b show a schematic of a control method of a cleaning robot according to an embodiment of the invention.
[0016] FIG. 4 is a flowchart of a control method for a cleaning robot according to an embodiment of the invention.
[0017] FIG. 5 shows a schematic of a control method of a cleaning robot according to another embodiment of the invention.
[0018] FIG. 6 is a functional block diagram of an embodiment of a cleaning robot according to the invention.
[0019] FIG. 7 is a schematic diagram of a logic level of the pin GPIO_ 1 of FIG. 6 .
[0020] FIG. 8 is a flowchart of a control method for a cleaning robot according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
[0022] FIG. 1 is a schematic diagram of a light generating device and a cleaning robot according to an embodiment of the invention. The light generating device 12 outputs a light beam 15 to label a restricted area that the cleaning robot 11 cannot enter. The cleaning robot 11 comprises a non-omnidirectional light detector 13 having a rib (or called mask) 14 , where the rib 14 produces a shadowed area on the non-omnidirectional light detector 13 by a predetermined angle and the range of the predetermined angle is from 30 degrees to 90 degrees.
[0023] The rib 14 may be fixed on the surface of the non-omnidirectional light detector 13 or movable along the non-omnidirectional light detector 13 . The rib 14 can be spun in 360 degrees along the surface of the non-omnidirectional light detector 13 . In this embodiment, the term, non-omni, is a functional description to describe that the rib 14 causes an area on the surface of the non-omnidirectional light detector 13 and the non-omnidirectional light detector 13 cannot not detect light therein or light to not directly reach that area.
[0024] Thus, the non-omnidirectional light detector 13 can be implemented in two ways. The first implementation is to combine an omni-light detector with a rib 14 and the rib 14 is fixed on a specific position of the surface of the omni-light detector. The non-omnidirectional light detector 13 is disposed on a plate that can be spun by a motor. Thus, the purpose of spinning of the non-omnidirectional light detector 13 can be achieved. When the non-omnidirectional light detector 13 detects the light beam, an incident angle of the light beam 15 can be determined by spinning the non-omnidirectional light detector 13 .
[0025] Another implementation of the non-omnidirectional light detector 13 is implemented by telescoping a mask kit on an omni-light detector, wherein the omni light detector cannot be spun and the masking kit is movable along a predetermined track around the omni light detector. The mask kit is spun by a motor. When the non-omnidirectional light detector 13 detects the light beam 15 , the mask kit is spun to determine the incident angle of the light beam 15 .
[0026] Reference can be made to FIGS. 2 a to 2 e for the detailed description of the non-omnidirectional light detector 13 .
[0027] FIG. 2 a is a top view of an embodiment of a non-omnidirectional light detector according to the invention. The mask 22 is formed by an opaque material and is adhered to a part of sensing area of an omni light detector 21 . The mask 22 forms a sensing dead zone with an angle θ on the omni light detector 21 .
[0028] Please refer to FIG. 2 b . FIG. 2 b is a flat view of the non-omnidirectional light detector of FIG. 2 a . In FIG. 2 b , the omni light detector 21 is fixed on a base 23 . The base 23 can be driven and spun by a motor or a step motor. A controller of the cleaning robot outputs a control signal to spin the base 23 . Although the typical type of omni light detector 21 can receive light from any direction, the omni light detector 21 cannot determined the direction that the light comes from and the cleaning robot cannot know the position of a light generating device or charging station. With the help of the mask 22 , the light direction can be determined.
[0029] When the omni light detector 21 detects a light beam, the base 23 is set to be spun for 360 degrees in a clockwise direction or a counter clockwise direction. When the omni light detector 21 cannot detect the light beam, a controller of the cleaning robot calculates a spin angle of the base 23 , wherein the spin angle ranges from 0 degree to (360-θ) degrees. The controller then determines the direction of the light beam according to a spin direction of the base 23 , the spin angle and the angle θ. Reference can be made to the descriptions related to FIG. 2 c and FIG. 2 d a more detailed description for estimating an incident angle of a light beam.
[0030] FIGS. 2 c and 2 d are schematic diagrams for estimating an incident angle of a light beam by using the proposed non-omnidirectional light detector according to the invention. In FIG. 2 c , the initial position of the mask 22 is at P 1 . When the non-omnidirectional light detector 25 detects a light beam 24 , the non-omnidirectional light detector 25 is spun in a predetermined direction. In this embodiment, the predetermined direction is a counter clockwise direction. In FIG. 2 d , when the non-omnidirectional light detector 25 does not detect the light beam 24 , the non-omnidirectional light detector 25 stops spinning. The controller of the cleaning robot determines a spin angle Φ of the non-omnidirectional light detector 25 and estimates the direction of the light beam 24 according to the spin angle Φ and the initial position P 1 .
[0031] In another embodiment, the non-omnidirectional light detector 25 is driven by a motor, and the motor transmits a spin signal to the controller for estimating the spin angle Φ. In another embodiment, the non-omnidirectional light detector 25 is driven by a step motor. The step motor is spun according to numbers of received impulse signals. The controller therefore estimates the spin angle Φ according to the number of impulse signals and a step angle of the step motor.
[0032] In another embodiment, the non-omnidirectional light detector 25 is fixed on a base device with a gear disposed under the base device, wherein meshes of the gear are driven by the motor. In another embodiment, the non-omnidirectional light detector 25 is driven by the motor via a timing belt.
[0033] FIG. 2 e is a schematic diagram of another embodiment of a non-omnidirectional light detector according to the invention. The non-omnidirectional light detector 26 comprises an omni light detector 27 , a base 28 and a vertical extension part 29 formed on the base 28 . The vertical extension part 29 is formed by an opaque material and forms a dead zone area on the surface of the omni light detector 27 . When the light beam is toward to the dead zone area, the omni light detector 27 cannot detect the light beam. The base 28 is spun by a motor to detect a light direction. The omni light detector 27 is not physically connected to the base 28 and the omni light detector 27 is not spun when the base is spun by the motor. Reference can be made to the descriptions related to FIGS. 2 c and 2 d for the light direction detection operation of the non-omnidirectional light detector 26 .
[0034] FIG. 3 a and FIG. 3 b show a schematic of a control method of a cleaning robot according to an embodiment of the invention. The light generating device 33 outputs a light beam to label a restricted area that the cleaning robot 31 cannot enter. The light beam comprises a first boundary b 1 and a second boundary b 2 . At time T 1 , the cleaning robot 31 moves along a predetermined route. At time T 2 , the light detector 32 detects a first boundary b 1 of the light beam output by the light generating device 33 . The cleaning robot 31 keeps moving along the predetermined route. In this embodiment, the light detector is a non-omnidirectional light detector or an omnidirectional light detector.
[0035] At time T 3 , the light detector 32 does not detect the light beam output by the light generating device 33 . The cleaning robot 31 keeps moving for a distance d and then is spun 180 degrees. At time T 4 of FIG. 3 b , the light detector 32 detects a first boundary b 1 of the light beam output by the light generating device 33 . At time T 5 , the light detector 32 does not detect the light beam output by the light generating device 33 . A controller of the cleaning robot 31 determines whether the cleaning robot 31 has left the restricted area according to the detection results of the light detector 32 at time T 4 and time T 5 .
[0036] FIG. 4 is a flowchart of a control method for a cleaning robot according to an embodiment of the invention. In the step S 41 , the cleaning robot moves according to a preset route. In the step S 42 , a controller of a light detector determines whether a light beam from the light generating device is detected by the light detector of the cleaning robot. If the light detector detects the light beam from the light generating device, step S 43 is executed. In this embodiment, the light detector is an omnidirectional light detector or a non-omnidirectional light detector, such as shown in FIG. 2 a - FIG. 2 e.
[0037] In the step S 43 , the controller of the light detector transmits a first trigger signal to a controller of the cleaning robot. In the step S 44 , the controller of the light detector determines whether the light detector detects the light beam from the light generating device. If yes, step S 44 is still executed. If not, step S 45 is executed. In the step S 45 , the controller of the light detector transmits a second trigger to the controller of the cleaning robot. In the step S 46 , the controller of the cleaning robot executes a corresponding procedure and the cleaning robot therefore move away from the restricted area labeled by the light beam output by the light generating device.
[0038] In this embodiment, the first trigger signal is a rising edge-triggered signal and the second trigger signal is a falling edge-triggered signal.
[0039] FIG. 5 shows a schematic of a control method of a cleaning robot according to another embodiment of the invention. The light generating device 53 outputs a light beam to label a restricted area that the cleaning robot 51 cannot enter. The light beam comprises a first boundary b 1 and a second boundary b 2 . At time T 1 , the cleaning robot 51 moves along a predetermined route. At time T 2 , the non-omnidirectional light detector 52 detects a first boundary b 1 of the light beam output by the light generating device 53 . The cleaning robot 51 does not stop immediately but stops after the cleaning robot 51 keeps moving for a distance d.
[0040] At time T 2 , when the non-omnidirectional light detector 52 detects the light beam output by the light generating device 53 , a controller of the cleaning robot 51 receives a first trigger signal. The controller of the cleaning robot 51 therefore knows that the cleaning robot 51 is near the restricted area and the controller can execute some operations, such as slowing down the moving speed of the cleaning robot 51 , pre-activating a light detection
[0041] At time T 3 , the non-omnidirectional light detector 52 does not detect the light beam output by the light generating device 53 . It means that the cleaning robot 51 has entered the restricted area. The controller of the cleaning robot 51 receives a second trigger signal and the controller prepares to stop the cleaning robot 51 according to the second trigger signal. In this embodiment, when the controller receives the second trigger signal, the controller stops the cleaning robot 51 after a predetermined duration t. In another embodiment, when the controller receives the second trigger signal, the controller stops the cleaning robot 51 after N clock cycles or N sampling times.
[0042] The controller determines the distance d or the duration t according to a moving speed, a moving mode or a breaking time.
[0043] At time T 3 , the non-omnidirectional light detector 52 is spun to determine the position of the light generating device 53 . Then, the controller of the cleaning robot 51 determines how the cleaning robot 51 leaves the light beam from the light generating device 53 . The controller of the cleaning robot 51 controls the cleaning robot 51 to spin 180 degrees and leaves along the original route or in another direction.
[0044] Assuming the controller of the cleaning robot 51 determines that the area I is not cleaned yet, the cleaning robot 51 is spun 180 degrees and leaves along the original route. When the cleaning robot 51 leaves the second boundary b 2 of the light beam from the light generating device 53 , the cleaning robot 51 moves to the light generating device 53 along the second boundary b 2 and cleans the area that the cleaning robot 51 had passed.
[0045] In another embodiment, if the controller of the cleaning robot 51 determines that the area I had been cleaned, and the area II is not cleaned yet, the controller of the cleaning robot 51 determines a shortest path to the area II and determines a first direction according to the shortest path. Then, the cleaning robot 51 moves in the first direction. In other words, the controller of the cleaning robot 51 controls the cleaning robot 51 to move to the un-cleaned area according to the cleaned area and the previous moving track.
[0046] FIG. 6 is a functional block diagram of an embodiment of a cleaning robot according to the invention. The controller 61 executes the program 62 and controls a detector 63 coupled to a general purpose input/output (GPIO) pin GPIO_ 1 of the controller 61 . The logic level of the pin GPIO_ 1 is preset at a first logic level. When the detector 63 detects the light beam output by a light generating device, the logic state of the pin GPIO_ 1 is changed from the first logic level to the second logic level. When the detector 63 does not detect the light beam output by a light generating device, the logic state of the pin GPIO_ 1 is changed from the second logic level to the first logic level. Thus, when the controller 61 receives a square wave signal via the pin GPIO_ 1 , it means that the cleaning robot has entered the restricted area.
[0047] FIG. 7 is a schematic diagram of a logic level of the pin GPIO_ 1 of FIG. 6 . Before time t 1 , the pin GPIO_ 1 maintains at the preset logic low level (L). At time t 1 , the light detector detects the light beam from the light generating device and the light detector pulls the logic level of the pin GPIO_ 1 to a logic high level (H). During the duration between time t 1 and time t 2 , the logic level of the pin GPIO_ 1 maintains at the logic high level (H) because the cleaning robot is moving at the area covered by the light beam from the light generating device.
[0048] At time t 2 , the cleaning robot leaves the area covered by the light beam from the light generating device and the light detector does not detect the light beam from the light generating device. The light detector pulls the logic level of the pin GPIO_ 1 down to a logic low level (L). During the duration between time t 2 and time t 3 , the cleaning robot moves a distance and leaves the restricted area in a first direction. The cleaning robot passes the area covered by the light beam from the light generating device again.
[0049] At time t 3 , the light detector detects the light beam from the light generating device again, and the light detector pulls the logic level of the pin GPIO_ 1 to a logic high level (H). During the duration between time t 3 and time t 4 , the logic level of the pin GPIO_ 1 maintains at the logic high level (H) because the cleaning robot is moving at the area covered by the light beam from the light generating device.
[0050] According to the above paragraphs, when the controller 61 detects the first square wave signal, such as the square wave signal between time t 1 and time t 2 , the cleaning robot has entered the restricted area. When the controller 61 detects the second square wave signal, such as the square wave signal between time t 3 and time t 4 , the cleaning robot has left the restricted area. Thus, the controller 61 controls the cleaning robot to leave the restricted area according to the program 62 and determines whether the cleaning robot has left the restricted area according to the number of the detected square wave signals.
[0051] FIG. 8 is a flowchart of a control method for a cleaning robot according to another embodiment of the invention. In the step S 801 , the cleaning robot moves according to a preset route. In the step S 802 , a controller of a light detector determines whether a light beam is detected by the light detector of the cleaning robot. If not, step S 801 is executed. If the light detector detects the light beam from the light generating device, step S 803 is executed to confirm whether the light beam is output by the light generating device. If the light beam is not output by the light generating device, step S 801 is executed. If the light beam is output by the light generating device, step S 804 is then executed.
[0052] In the step S 804 , the controller of the light detector transmits a first trigger signal to a controller of the cleaning robot, and the cleaning robot still moves along the preset route. In the step S 805 , the controller of the light detector or the controller of the cleaning robot determines whether the light detector detects the light beam. If yes, step S 804 is executed. If light detector does not detect the light beam, the step S 806 is executed.
[0053] In the step S 806 , the controller of the light detector transmits a second trigger signal to the controller of the cleaning robot. Then, in the step S 807 , the controller of the cleaning robot determines a leaving direction and the cleaning robot left from the restricted area according to the leaving direction.
[0054] In the step S 808 , the controller of the light detector determines whether the light detector detects the light beam. If the light detector does not detect the light beam, the procedure returns to the step S 807 . If the light detector detects the light beam, step S 809 is executed. In the step S 809 , the light detector transmits a third trigger signal to a controller of the cleaning robot, and the cleaning robot keeps moving.
[0055] In the step S 810 , the controller of the light detector or the controller of the cleaning robot determines whether the light detector detects the light beam. If yes, step S 809 is executed and the cleaning robot keeps moving along the preset route. If light detector does not detect the light beam, the step S 811 is executed.
[0056] In the step S 811 , the controller of the light detector transmits a fourth trigger signal to the controller of the cleaning robot. When the controller of the cleaning robot receives the third trigger signal and the fourth trigger signal, the controller of the cleaning robot confirms that the cleaning robot has left the restricted area. In other words, the third trigger signal and the fourth trigger signal can be referenced for determining whether the cleaning robot has left the restricted area.
[0057] While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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An embodiment of the invention provides a control method of a cleaning robot. The method includes steps of moving the cleaning robot according to a first direction; keeping moving the cleaning robot according to the first direction when a light detector of the cleaning robot detects a light beam; moving the cleaning robot for a predetermined distance and then stopping the cleaning robot when the light detector does not detect the light beam; and moving the cleaning robot in a second direction.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. patent application Ser. No. 10/922,041, filed Aug. 19, 2004 by inventors Eric White and Patrick Turley, entitled “SYSTEM AND METHOD FOR PROVIDING A SECURE CONNECTION BETWEEN NETWORKED COMPUTERS,” issued as U.S. Pat. No. 7,624,438, which in turn claims a benefit of priority under 35 U.S.C. §119(e) to the filing date of U.S. Provisional Application No. 60/496,629, filed Aug. 20, 2003 by inventors Eric White and Patrick Turley, entitled “SYSTEM AND METHOD FOR PROVIDING A SECURE CONNECTION BETWEEN NETWORKED COMPUTERS,” the entire contents of which are hereby incorporated by reference herein for all purposes.
TECHNICAL FIELD
[0002] Embodiments disclosed herein relate generally to methods and systems for computer connectivity and, more particularly, to methods and systems for establishing and providing secure connections between computers.
BACKGROUND
[0003] The use of computer networks to store data and provide information to users is increasingly common. In fact, in many cases it may be necessary for a computer to be connected to a specific network to retrieve data desired or needed by a user. To connect to a specific network, a user at a client computer may utilize a network connection, such as the Internet, to connect to a computer belonging to the network.
[0004] The Internet is a loosely organized network of computers spanning the globe. Client computers, such as home computers, can connect to other clients and servers on the Internet through a local or regional Internet Service Provider (“ISP”) that further connects to larger regional ISPs or directly to one of the Internet's “backbones.” Regional and national backbones are interconnected through long range data transport connections such as satellite relays and undersea cables. Through these layers of interconnectivity, each computer connected to the Internet can connect to every other (or at least a large percentage) of other computers on the Internet. Utilizing the Internet, a user may connect to any of the networks within the Internet.
[0005] The arrangement of the Internet, however, presents a whole host of security concerns. These concerns revolve mainly around the fact that communications between a client computer and a server computer residing in a remote network may travel through a wide variety of other computers and networks before arriving at their eventual destinations. If these communications are not secured, they are readily accessible to anyone with a basic understanding of network communication protocols.
[0006] To alleviate these security concerns, a virtual private network or VPN may be established between a client computer and another network. A VPN may allow private and secure communications between computers over a public network, while maintaining privacy through the use of a tunneling protocol and security procedures. These tunneling protocols allow traffic to be encrypted at the edge of one network or at an originating computer, moved over a public network like any other data, and then decrypted when it reaches a remote network or receiving computer. This encrypted traffic acts like it is in a tunnel between the two networks or computers: even if an attacker can see the traffic, they cannot read it, and they cannot change the traffic without the changes being seen by the receiving party and therefore being rejected.
[0007] VPNs are similar to wide area networks (WAN), but the key feature of VPNs is that they are able to use public networks like the Internet rather than rely on expensive, private leased lines. At they same time, VPNs have the same security and encryption features as a private network, while adding the advantage of the economies of scale and remote accessibility of large public networks.
[0008] VPNs today are set up a variety of ways, and can be built over ATM, frame relay, and X.25 technologies. However, the most popular current method is to deploy IP-based VPNs, which offer more flexibility and ease of connectivity. Since most corporate intranets use IP or Web technologies, IP-VPNs can more transparently extend these capabilities over a wide network. An IP-VPN link can be set up anywhere in the world between two endpoints, and the IP network automatically handles the traffic routing.
[0009] A VPN, however, is not without its flaws. First of all, to establish a VPN, both computers must utilize identical VPN protocols. As there are a wide variety of VPN protocols in use, such as PPTP, IPsec, L2TP etc. this is by no means guaranteed. If identical protocols are not originally on one or more of the computers, identical protocols must be installed on both of these systems before a VPN may be established.
[0010] Additionally, even if the computers are running the same protocol, this protocol may still have to be manually setup and configured. In many cases, every time a remote user wishes to establish a VPN with a computer over an existing network he must bring up the VPN protocol he wishes to use and properly configure it to work with the remote computer or network he wishes to access.
[0011] These installation and configuration issues may present problems to someone who is not well versed in the area of network protocols, and may even present problems for those who are familiar with these protocols, as typically a remote user must configure his computer without access to the gateway to which he wishes to connect.
[0012] Even more problematic, however, is that setting up a VPN still presents security issues. Almost universally, a gateway at a remote network is not going to establish a VPN with a random remote computer. In most cases, the remote gateway requires a username and a password before it will establish a VPN connection. This username and password is sent from the remote user in an unsecured form, or encrypted using a weak encryption algorithm. As this username and password are easily snooped by malicious users of a public network, a security hole exists within the very process of trying to create a VPN to provide greater security.
[0013] Thus, a need exists for more secure methods and systems for establishing a secure connection between computers which require minimum amounts of manual configuration.
SUMMARY OF THE DISCLOSURE
[0014] Systems and methods for establishing or providing a secure connection between networked computers are disclosed. A computer may make a request for a secure connection to another computer. In response, configuration data may be sent to the requesting computer. This configuration data may execute on the requesting computer in order to create a secure connection between the two computers. Using this secure connection, data may be passed between the two computers with a greater degree of privacy.
[0015] Furthermore, protocols inherent to particular operating systems may be utilized to setup and establish a secure connection between networked computers in an automated fashion, requiring no manual intervention or configuration by the user of a computer. The configuration data sent to the requesting computer may automatically configure a protocol on the requesting computer and automatically establish a secure connection with another networked computer.
[0016] In one embodiment, a connection is requested in a first protocol, data is sent in response to the request, a second protocol is configured using the data and a secure connection is established using the second protocol.
[0017] In another embodiment, the first protocol is HTTPS.
[0018] In yet another embodiment, the data is sent using the first protocol.
[0019] In other embodiments, the request for the connection includes a username and a password.
[0020] In still other embodiments, data is sent only if the username and password are verified.
[0021] In yet other embodiments, the data includes a controller.
[0022] In some embodiments, the controller is an Active X controller.
[0023] In a particular embodiment, the data includes a credential and the secured connection is established using the credential.
[0024] In one embodiment, the credential is dynamically generated in response to the request and includes a password and a username.
[0025] In additional embodiments, the credential is valid only for the duration of the secure connection.
[0026] In other embodiments, the second protocol is PPTP and is configured automatically using the controller.
[0027] In one embodiment, the secure connection is established automatically using the controller.
[0028] These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. The following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions or rearrangements may be made within the scope of the invention, and the invention includes all such substitutions, modifications, additions or rearrangements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer impression of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore nonlimiting, embodiments illustrated in the drawings, wherein identical reference numerals designate the same components. Note that the features illustrated in the drawings are not necessarily drawn to scale.
[0030] FIG. 1 includes an illustration of exemplary architecture for use in describing various embodiments of the systems and methods of the present invention.
[0031] FIG. 2 includes a flow diagram of one embodiment of a method for establishing a secure connection between two computers.
[0032] FIG. 3 includes a representation of applying an embodiment of a method for establishing a secure connection to portions of the architecture depicted in FIG. 1 .
[0033] FIG. 4 includes a representation of one embodiment of VPN client software.
[0034] FIG. 5 includes an illustration of another exemplary architecture where embodiments of the systems and methods of the present invention may find applicability.
DETAILED DESCRIPTION
[0035] The invention and the various features and advantageous details thereof are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well known starting materials, processing techniques, components and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only and not by way of limitation. After reading the specification, various substitutions, modifications, additions and rearrangements will become apparent to those skilled in the art from this disclosure which do not depart from the scope of the appended claims.
[0036] Initially, a few terms are defined to aid the reader in an understanding of the following disclosure. The term “controller” is intended to mean any set of data or instructions operable to perform certain tasks or a combination of hardware (such as a processor) and software instructions capable of performing a certain task.
[0037] The term “networked” is intended to mean operable to communicate. For example, two networked computers are operable to communicate with one another using techniques known in the art, such as via a wireless or wired connection using TCP/IP. Two computers may be networked through a variety of networks, sub-networks, etc.
[0038] Before discussing embodiments of the present invention, an exemplary architecture for use in illustrating embodiments of the present invention is described. It will be apparent to those of ordinary skill in the art that this is a simple architecture intended for illustrative embodiments only, and that the systems and methods described herein may be employed with any variety of more complicated architectures. Each of the computers depicted may include desktops, laptops, PDAs or any other type of device capable of communicating, either via wireless or wired connection, over a network. Each network depicted, whether they be intranets or any other type of network, may include sub-networks or any combination of networks and sub-networks
[0039] FIG. 1 illustrates just such an exemplary architecture. In FIG. 1 , intranet 100 is a private network composed of client computers 110 and server 120 . Client computers 110 may be coupled to server 120 , which is in turn coupled to public network 130 , such as the Internet. Client computers 110 may not be coupled directly to public network 130 . Therefore, to access public network 130 , client computers 110 may communicate with server 120 , which in turn serves as a gateway to public network 130 as is commonly known in the art. Data residing within intranet 100 may be sensitive. Consequently, server 120 may also serve as a firewall for intranet 100 , preventing unauthorized users on public network 130 from accessing intranet 100 . Remote client computer 140 may also be coupled to public network 130 via a wired or wireless connection, as is known in the art. Therefore, remote client computer 140 and server 120 may be capable of communication via public network 130 . For example, server 120 may serve both as a firewall to protect intranet data and a gateway to permit secured access to the intranet and all computers and servers hosted therein by remote client computer 140 .
[0040] Attention is now directed to systems and methods for establishing a secure connection between two computers over a network according to one embodiment of the invention. Typically, a user at a remote client computer wishes to establish a connection with an intranet or a computer within an intranet. To accomplish this, the remote client computer and a server computer belonging to the intranet may create a VPN so information may be securely transferred between the remote client computer and the server computer or other computers within the intranet. To securely establish this VPN with a minimum of configuration, the remote client computer may make a request for a VPN connection to the server. In response, the server may send configuration data to the remote client computer. This configuration data may execute on the remote client computer in order to create a secure VPN connection between the remote client and the server. Using this secure connection, data may be passed between server and remote client with a greater degree of privacy.
[0041] These systems and methods may be explained in more detail with reference to the exemplary hardware architecture of FIG. 1 . Suppose a user at remote client computer 140 wishes to securely interact with intranet 100 . To accomplish this, remote client computer 140 can request a secure connection from server 120 over network 130 . In response, server 120 may send configuration data to remote client computer 140 . Using this configuration data, a secure connection may be established between remote client computer 140 and server computer 120 , after which remote computer 140 may interact with computers 110 , 120 of intranet 100 as if remote computer 140 belonged to intranet 100 .
[0042] In one particular embodiment, to obtain connectivity between remote client computer 140 and server 120 a transient VPN may be established between server 120 and remote client computer 140 using public network 130 . This transient VPN may provide a dynamic, secure connection between remote client computer 140 and server 120 by creating a transient VPN endpoint on remote client computer 140 that connects through a VPN tunnel to server 120 . This VPN connection may be established using a wide variety of VPN protocols, as are known in the art, such as PPTP, IPsec, L2TP etc.
[0043] Furthermore, protocols inherent to particular operating systems may be utilized to setup and establish a transient VPN endpoint on remote client computer 140 in an automated fashion, requiring no manual intervention or configuration by the user of remote client computer 140 . For example, suppose remote computer 140 and server are both executing a Windows based operating of the type developed by Microsoft, such as Windows98, WindowsXP, Windows2000, etc. As Windows based operating system have the PPTP VPN protocol built into them, this protocol may be used advantageously to automatically establish a VPN between remote client computer 140 and server 120 if both are executing a Windows based operating system.
[0044] Turning now to FIG. 2 , a flow diagram for one method of establishing a secure connection between networked computers is depicted. To establish a secure connection between two networked computer, the first step may be to ensure that the protocol to be utilized in establishing this secure connection is installed on both computers, and if it is not, to install the desired protocol on the computer(s) that do not have it (Step 210 ). For example, if a VPN connection is desired between remote client computer 140 and server computer 120 a wide variety of VPN protocols may be used to establish this connection, such as IPsec, L2TP, PPTP, MPLS etc. If, however, it is desired to use IPsec and remote client computer 140 does not have the IPsec protocol installed or configured, it may be necessary to install the IPsec protocol (Step 210 ) on remote client computer 140 before this particular protocol may be utilized in establishing a VPN connection. This installation may only need to occur once, and may, for example, be accomplished by an IT manager responsible for intranet 110 or remote client computer 140 .
[0045] At any time after the desired protocol is installed on the computers (Step 210 ), a secure connection may be requested by one of the computers (Step 220 ). For example, remote client computer 140 may request a secure connection from server computer 120 . This request (Step 220 ) may be in any format used to communicate over the network connection between the two computers, such as FTP, HTTP or HTTPS. In response to this request (Step 220 ), a response may be sent to the requesting computer (Step 230 ). This response (Step 230 ) may be sent to the requesting computer using the same format used in the initial request (Step 220 ), such as FTP, HTTP or HTTPS, and include a set of data designed to establish a secure connection between the two computers using a particular protocol. This set of data may comprise a controller configured to execute on the requesting computer and a set of credentials to be used in conjunction with the controller.
[0046] The set of data sent in this response (Step 230 ) may provide information to be utilized by a protocol on the requesting computer when connecting to a particular networked computer using the protocol (Step 240 ). This information may include the IP address or host name of a server, the authentication domain name, whether MPPC is to be utilized, which call-control and management protocol is to be used, a DNS configuration etc. Providing this information to the protocol may be referred to as “configuring a protocol” and that phrase will be used as such herein. In some instances, a controller contained in the response to the requesting computer executes on the initiating computer and configures the protocol to establish a secure connection using the credentials contained in the response (Step 230 ).
[0047] After this configuration process (Step 240 ), a secure connection may be initiated using the configured protocol (Step 250 ), and a secure connection established (Step 260 ). In some instances, a request for a secure connection may be initiated by the same controller responsible for configuring the protocol, and include the credentials contained in the sent response (Step 230 ). After verifying the credentials a secure connection may be established (Step 260 ).
[0048] It will be clear to those of ordinary skill in the art that the method depicted in the flow diagram of FIG. 2 may be tailored to implement a secure connection between two computers in a variety of architectures, and may employ a variety of different protocols for the various communications and secure connections.
[0049] Note that FIG. 2 represents one embodiment of the invention and that not all of the steps depicted in FIG. 2 are necessary, that a step may not be required, and that further steps may be utilized in addition to the ones depicted, including steps for communication, authentication, configuration etc. Additionally, the order in which each step is described is not necessarily the order in which it is utilized. After reading this specification, a person of ordinary skill in the art will be capable of determining which arrangement of steps will be best suited to a particular implementation.
[0050] In fact, embodiments of the methods and systems of the present invention may be particularly useful in establishing a secure connection between two computers by automatically configuring a protocol built into an operating systems executing on both of the computers, alleviating the need for a user to install or configure such a protocol manually.
[0051] FIG. 3 depicts one embodiment of a method for automatically establishing a transient VPN connection between a remote client computer and a server both executing a Windows based operating system containing the point-to-point tunneling protocol (PPTP) for establishing VPNs. Remote client computer 140 may send a connection request (Step 220 ) to server computer 120 indicating that remote client computer 140 wishes to establish a VPN connection with server 120 . This request may be initiated by a user at remote computer 140 . Though this request may be initiated in a variety of ways, in many instances a user at remote client computer 140 may initiate this request using an HTTP client. For example, via an internet browser of the type commonly know in the art, such as Netscape or Internet Explorer.
[0052] Using this browser, a client at remote client computer 140 may navigate to a particular URL in a known manner, perhaps by typing it directly into an address window within the browser, accessing the URL in his bookmarks file, or navigating to the URL by clicking on an HTTP link within a page. By pointing his browser to a particular URL, the user at remote client computer 140 initiates a connection request to server 120 computer. This URL may also contain an HTML form requesting a username and password from a user at remote computer 140 , in order to authenticate a user at remote computer 140 .
[0053] In some embodiments, this connection request (Step 220 ) is sent from HTTP client on remote client computer 140 to server 120 using HTTP. However, to better secure the connection request, in other embodiments the connection request from remote client computer 140 to server computer is made using HTTPS, which may be sent via an SSL connection between remote client computer 140 and server computer 120 .
[0054] In response to the connection request (Step 220 ) from remote client computer 140 , server computer 120 may send data to remote client computer 140 which will facilitate the establishment of a VPN connection between server and remote client computer (Step 230 ). If the connection request (Step 220 ) from remote client computer 140 contained a username or password, server computer 120 may first authenticate or authorize the requesting user at remote client computer 140 . Logic on server computer 120 may verify the username or password submitted in the connection request (Step 220 ) possibly by authenticating them against a form of user database (RADIUS, LDAP, etc.). If the user's authentication profile permits, server 120 may then send a response to remote client computer 140 with the configuration data (Step 230 ). This data may include VPN client software designed to utilize a VPN protocol on remote client computer 140 to automatically establish a secure VPN connection between server computer 120 and remote client computer 140 without any action by the user of remote client computer 140 .
[0055] In one specific embodiment, the VPN client software is sent to remote client computer 140 using HTTPS, and includes a controller designed to establish a secure VPN connection between server 120 and remote client computer 140 , and a set of credentials. These credentials may be session specific, and dynamically generated by server computer 120 using a random-seed. Additionally, this VPN client software may be digitally signed with an X.509 digital certificate, of the type know in the art, so that remote client computer 140 recognizes that the origin of the VPN client software is server computer 120 . Once the origin of VPN client software is verified, it may then be installed or executed on remote client computer 140 to establish a secure VPN connection.
[0056] FIG. 4 depicts a block diagram of one embodiment of the client software which may be sent from server computer 120 to remote client computer 140 (Step 230 ). VPN client software 400 may include controller 410 designed to configure a protocol on remote client computer 140 and establish the VPN connection between server 120 and remote client computer 140 . In many cases, this controller 410 is designed to utilize a VPN protocol resident on remote client computer 140 to establish this connection. This controller may be written in a variety of programming or scripting languages as are known in the art, such as C, C++, Java, etc.
[0057] Once VPN client software 400 is downloaded and controller 410 executed, controller 410 may establish a secure VPN connection between remote client computer 140 and server 120 . To continue with the above example, remote client computer 140 may be executing a Windows based operating system, and controller 410 may be an Active X controller designed specifically to configure the PPTP bundled in the Windows operating system software. Therefore, once VPN client software 400 is downloaded to remote client computer 140 , Active X controller 410 may execute automatically on remote client computer 140 , making system library calls to configure the PPTP resident on remote client computer 140 as a PPTP client.
[0058] Using the configured PPTP client, Active X controller 410 may then automatically establish a secure VPN connection with server computer 120 . This secure connection may be automatically established by controller 410 by making additionally system library calls on remote client computer 140 to initiate a tunnel request (Step 240 ) from remote client computer 140 to server computer 120 . As noted above, PPTP libraries are installed with most Windows based operating systems. Thus, Active X controller executing on remote client computer 140 may configure the PPTP to establish a secure VPN connection with remote server and initiate a tunnel request, without any interference or input by a user of remote client computer 140 .
[0059] Additionally, in some embodiments, controller 410 may utilize credentials 420 in establishing the secure VPN connection between server computer 120 and remote client computer 140 . As mentioned above, credentials 420 may have been dynamically generated by server computer 120 and sent in the response (Step 230 ) to initial connection request (Step 220 ). Credentials 420 may contain a password and username. Controller 410 may use this username and password as parameters when establishing the VPN connection between remote client computer and server computer. Credentials may be sent with tunnel request (Step 250 ) and verified by server computer 120 before establishing a VPN connection with remote computer 140 . Since server computer 120 initially created credentials 420 , server may identify the credentials from remote client computer 140 and associate a particular VPN connection with a particular remote client computer.
[0060] Credentials 420 , including the username and password may then be used for the duration of that particular session between remote client computer 140 and server computer 140 . Once the VPN connection between remote client computer and server computer is severed, username and password may lose their validity, preventing their unauthorized use in the future.
[0061] Embodiments of the systems and methods disclosed will be useful in a variety of architectures, as will be apparent to those of skill in the art after reading this disclosure. FIG. 5 depicts an example of another architecture where these systems and methods might find useful application. Wireless router 510 and server 512 may serve as wireless access point 514 to Internet 520 , as is known in the art. Remote client computer 140 may be wirelessly coupled to server 512 and Internet 520 through router 510 in a public venue. In this architecture, embodiments of these systems and methods may be utilized to secure wireless communications, in a public venue, between remote client computer 140 and access point 514 , securing the public wireless network segment, without the need for pre-shared keys or passphrases.
[0062] For example, after remote client computer 140 enters the range of wireless router 510 , remote client computer 140 may associate with access point 514 . Remote client computer 140 may then request a secure connection with server 512 via a browser based interface. Client software 400 , including controller 410 and credentials 420 may be downloaded to remote client computer 140 using HTTPS, at which point the controller automatically configures the PPTP on remote client computer 140 and establish a VPN tunnel between remote client computer 140 and wireless access point 514 . From this point, wireless communications between remote client computer and access point 514 may be made using this VPN tunnel, and are therefore, more secure.
[0063] Although the present disclosure has been described in detail herein with reference to the illustrative embodiments, it should be understood that the description is by way of example only and is not to be construed in a limiting sense. It is to be further understood, therefore, that numerous changes in the details of the embodiments disclosed herein and additional embodiments will be apparent to, and may be made by, persons of ordinary skill in the art having reference to this description. Accordingly, the scope of the present disclosure should be determined by the following claims and their legal equivalents.
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Embodiments disclosed herein provide a system, method, and computer program product for establishing a secure network connection between two computers, a client and a server. The client may send a connection request over a public network to the server. In response, the server may generate a set of credentials, select a controller to automatically run on the client, and send the controller and the set of credentials to the client. The controller automatically executes on the client and utilizes the set of credentials from the server to establish a secure network connection with the server without user intervention. The set of credentials is valid until the secure network connection between the client and the server is severed.
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BACKGROUND
Snow removal from other than highways is a major and essential activity, involving small and medium size vehicles such as the small four-wheel drive vehicles known as Jeeps, or pickup trucks, equipped with removable snowplow blades for clearing snow from parking lots, service stations, driveways, and even sidewalks. The blades are generally of fixed length slightly greater than the width of the vehicle, and are supported by adjustable framework permitting the blade to be held against the ground or to be lifted well above the ground for transit to and from the place of use, and also permitting the blade to be perpendicular to the direction of motion for pushing snow ahead to an out of the way location or to be at an angle for pushing the snow to one side or the other.
Such blades are necessarily limited in length transversely of the vehicle for compliance with regulations as to overall dimensions of road vehicles and as to extent of projection beyond the vehicle structure, and also to permit passage through restricted spaces such as between gateposts or trees. The consequence is that effective snow removal generally requires many more trips of the vehicle, and therefore much greater expense than would be the case with longer snowplow blades on the same vehicle.
This problem has been dealt with in the past by equipping heavy vehicles specifically designed for snow removal with wings or extensions which can be extended or retracted by mechanism actuated from the driver's location, to suit the condition which may be encountered. For smaller vehicles, some use has been made of extensions which can be bolted to one or both ends of the snowplow blade when needed, and stowed in the body of the vehicle when not needed. The former mechanized adjustment of width is far too expensive for other than highway use, and the latter is too cumbersome and inconvenient because of the need for tools, the likelihood of loss of the nuts and bolts, and the problem of finding a satisfactory stowage location when the extensions are not being used. The consequence is that almost all snow removal is carried out with snowplow blades of fixed length.
SUMMARY OF THE INVENTION
I have found that snowplows, and particularly those mounted on light vehicles, can be equipped quite inexpensively with snowplow blade extensions of a sturdy construction, yet so simple that the blade can be converted from its basic length to an extended length and vice versa in a matter of seconds.
The invention which makes this desirable result so easily possible involves provision of one or a pair of snowplow blade extensions matching the curvature or other shape of the basic snowplow blade, and provided with projecting supports which can be inserted in sockets in or on the basic snowplow blade and be pinned in place.
This invention preferably involves also auxiliary sockets for mounting the snowplow blade extensions on the basic snowplow blade in an inactive position for convenience and safety in travel to and from work sites, and for rapid and simple transfer to the operating position, without the need for using any tools, or at most anything capable of delivering a light blow such as a rock, a chunk of wood, or a small hammer.
THE DRAWINGS
In the accompanying drawings, FIG. 1 is a representation of the manner in which a conventional snowplow blade is mounted on the front of a light motorized vehicle.
FIG. 2 shows a preferred form of snowplow blade extension for mounting on a conventional blade, and the modification of the basic blade for receiving the extension.
FIG. 3 is a view of an enlarged scale of the simple holding and fastening arrangement of FIG. 2.
FIG. 4 shows an alternative arrangement for fastening a snowplow blade extension.
DETAILED DESCRIPTION
Referring to FIG. 1, conventional snowplows for small and medium motorized vehicles, such as light truck 10, generally have a horizontal A-frame 11 mounted on a horizontal transverse pivot, not shown, under the front end of the vehicle frame.
The A-frame 11 is normally raised to a travel position and lowered to a working position by a manually operated or power driven lifting device 12. At the tip of the A-frame 11 a vertical pivot 13 supports a horizontal bar 14 which can be swung into various transverse or angular positions with respect to the direction of motion of vehicle 10 and held in the desired position as by pin 15.
A snowplow blade 20 having the general shape of a segment of a cylinder has two arcuate stiffener bars 21 of curved angle iron extending from top to bottom on its rear face, with pivot pins 22 connecting the ends of horizontal bar 14 to the flanges of stiffeners 21 so that the blade 20 can pivot on the transverse axis through pivot pins 22.
The blade 20 is held in a generally vertical position with its concave face forward by springs 23. If the bottom edge of blade 20 should strike an immovable and perhaps hidden object such as a curb, a rock, or a stump, the springs permit the blade 20 to tilt and slide over the obstacle.
In accordance with this invention, a conventional snowplow blade such as that described above is modified by providing sockets for mounting an extension at one end of the blade, or a pair of extension for both ends.
Referring to FIG. 2, showing a preferred form of the invention, an extension 30 is made from the same kind and curvature of steel plate as the blade 20. To the extension are welded a pair of mounting studs 31, which may be solid rods, or may be tubular for greater lightness and stiffness. The studs 31 extend horizontally across the back of extension 30 close to the top and bottom edges.
To the back of blade 20, close to the top and bottom in a position corresponding to the location of studs 31 are welded a pair of tubular sockets 32 of a size permitting studs 31 to pass easily through so that the extension 30 will fit snugly against the edge of blade 20.
Each stud 31 has a hole 33 in its free end which projects beyond the socket 32 to receive a locking pin 34. In turn locking pin 34 is drilled to receive a spring clip 35 to prevent locking pin 34 from bouncing out of its position in hole 33. Each pin 34 and clip 35 is fastened to blade 20 by a light chain 36 so that it cannot be lost.
Practical experience in use of the arrangement described above is that the extensions are easily installed and removed if reasonable clearances are provided between the studs 31 and sockets 32, except when working in wet snow, when there may be some tendency for ice to form in the interstices, as well as around locking pins 34 and spring clips 35. Even then, the foregoing construction permits easy loosening and removal of spring clips 35, and then locking pins 34 by a light tap. Removal of studs 31 from sockets 32 is not quite so simple because it is necessary to move both fastenings together along parallel paths, or each one alternately with the other for a short distance, particularly if the extension should become bent and not restored exactly to its original condition. It is accordingly preferred to weld hammer pads 37 to each extension close to each mounting 31. A few taps of a hammer or other solid object against pads 37 will remove extension 30 very quickly without battering or otherwise damaging the mounting studs 31.
Convenient use of extensions requires provision of a place for carrying them when they are not in use. Accordingly, an extra socket 28 is welded to the back of blade 20 in a location such that extension 30 can be supported by socket 38 on the back of blade 20 without projecting beyond its lateral edge. This socket 38 is provided with a locking pin 34 and spring clip 35 to prevent loss of the extension 30 during activities not requiring the extension to be in its operating position. This carrying socket 38 must, of course, have its axis spaced somewhat farther from the surface of blade 20 than socket 32 to allow for the thickness of the extension 30. A lower socket is not required in this inactive position of extension 30.
Although the preferred form of the invention described above is quite simple in construction and reliable and convenient in use, many other arrangements for quick and firm mounting and removal of a blade extension are possible.
FIG. 4 shows one such alternative in which snowplow blade 40 is drilled with holes 41 in two or more locations near a lateral edge, to function as sockets for holding an extension of the blade. An extension 42 in this case is made longer than the desired amount by which the blade is to be extended, by a distance sufficient to extend somewhat beyond each drilled hole 41. Studs 43 are welded to the back of extension 42 in locations corresponding to those of holes 41 so that the studs 43 can extend through the basic blade 40. A pin 44 is then passed through a transverse hole in each stud 43 to lock it temporarily in place. This can be a single pin as shown, or a solid pin locked by a spring pin, each held by a chain to prevent loss, as shown in FIG. 3.
The extension shown in FIG. 4 can be hung on blade 40 at times when a snowplow blade extension is not needed, by providing a second group of holes 45 far enough from the end of the blade 40 that studs 43 in holes 45 will place the extension 42 snugly against blade 40 where it can be carried conveniently or can be used for snow removal where a short blade is preferred.
In the embodiment just described, the thickness of extension 42 is so small as not to affect noticeably the transverse movement of snow, along the length of the blade 40.
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Snowplow blades can be immediately varied in length at one or both ends by providing extensions of the same shape as the blade, which extensions carry studs which are received in sockets, preferably lengthwise of the back of the blade. The studs are pinned in the sockets for quick and easy fastening and removal.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. application Ser. No. 10/144,599, filed May 13, 2002, which was based on provisional Application Ser. No. 60/292,554, filed May 22, 2001.
BACKGROUND
[0002] This invention pertains to service windows and, more particularly, to service windows for drive-thru and walk-up fast food service installations. These service windows are typically provided in a building, such as a fast-food service establishment, a convenience drive-up food store, a service station attendant's booth, a free-standing kiosk, or the like.
[0003] Service windows are typically installed on the side of a building adjacent a driveway or sidewalk to facilitate business transactions between an employee and a customer. Such windows conventionally permit an employee to view a customer approaching the window and to personally transact business with the customer. In a typical commercial environment, a drive-up service window permits the employee to transact business with a customer and yet provides the necessary isolation between the outside environment and the inside environment to satisfy health and safety requirements.
[0004] In some cases, the service window may be operated by the employee while the employee is holding products to be passed through the service window. As a result, the employee's hands may not be free to operate various window mechanisms or operators. Thus, automatic detectors have been provided in association with service windows to automatically open the windows at the appropriate time. For example, detectors such as optical or infrared detectors may detect the presence of the employee proximate to the window and may automatically open the window.
[0005] However, existing automatic windows may be prone to inadvertent operation. For example, anytime the employee stands too close to the window, the window may open. This may be disadvantageous, particularly where climatic conditions are adverse. In addition, excessive window opening in a restaurant environment may raise some health issues.
[0006] Thus, there is a need for better ways to operate service windows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of a service window in accordance with one embodiment of the present invention;
[0008] FIG. 2 is a partial perspective of a part of the window shown in FIG. 1 according to one embodiment of the present invention;
[0009] FIG. 3 is a schematic depiction of one embodiment of the present invention;
[0010] FIG. 4 is a schematic depiction of a service window in use in accordance with one embodiment of the present invention;
[0011] FIG. 5 is a flow chart, useful in accordance with one embodiment of the present invention;
[0012] FIG. 6 is a flow chart, useful in accordance with another embodiment of the present invention;
[0013] FIG. 7 is a flow chart, useful in accordance with still another embodiment of the present invention;
[0014] FIG. 8 is a schematic depiction of another embodiment; and
[0015] FIG. 9 is a front elevational view of one embodiment of a remote window controller worn by a service employee.
DETAILED DESCRIPTION
[0016] In one embodiment of the present invention, shown in FIG. 1 , a service window 10 has a frame 14 including a top cross piece 16 and a bottom cross piece 18 . Two side pieces 20 , 22 connect the top cross piece 16 and the bottom cross piece 18 . A fixed window pane 24 may be provided within the frame 14 in one embodiment. A sliding window pane 26 moves between open and closed positions, thereby opening or closing the window 10 . An electric motor 28 may drive a linkage 30 connected to the sliding pane 26 . The linkage 30 moves the sliding window pane 26 in response to the action of the electric motor 28 .
[0017] Those skilled in the art will recognize that although a sliding window is illustrated, other automatic window configurations may also be used, such as folding, biparting, or swinging windows. Also, while a window 10 with only one moving glass panel is shown in FIG. 1 , in other embodiments there may be more than one moving glass panel. In addition, while a motorized window is illustrated, in other embodiments audible commands may be used to trigger operation of non-motorized windows, including those with mechanical operators.
[0018] A microphone 32 may detect sound or vocal commands. A sound recognition module 34 identifies an audible command to open or close the window 10 . For example, the module 34 may generate a signal that controls the motor 28 . The module 34 may be located any where on the window 10 or remotely therefrom.
[0019] The module 34 advantageously distinguishes between the voice of the employee using the window 10 and background noise from within the service establishment in one embodiment of the present invention. A particular word or phrase may be selected in some embodiments to activate the window 10 . In other embodiments, a distinct non-vocal sound may be used to trigger the module 34 .
[0020] The microphone 32 may be mounted on the window 10 , for example on a side piece 22 , or at another location, remote from the window 10 . A remote microphone 32 may be coupled by a wired or wireless connection to the module 34 . The microphone 32 may be associated with the employee, for example, via a headset microphone or a lapel microphone, as two examples of remote microphones.
[0021] The module 34 may be used alone or in connection with other apparatus for controlling the service window 10 . For example, proximity sensors 42 may be used to detect the presence of an employee reaching towards the service window 10 . Upwardly, outwardly, or downwardly directed proximity sensors 42 may be used. The control module 34 may receive a signal from a sensor 42 indicating that the employee is adjacent the window 10 in one embodiment. Proximity sensors may be light beams, infrared beams, pattern detecting cameras, or switches, to mention a few examples.
[0022] The proximity sensors 42 may be used for connection with an automatic closure mechanism in one embodiment of the present invention. After opening the window, a timer may start. After a time out, the window 10 may be automatically closed unless proximity is detected by the sensor 42 .
[0023] Activation of a manual control switch 48 , shown in FIG. 2 , may override signals from other sensors, including the module 34 . In this way, the window 10 may still be operated open or closed even if conditions, such as background noise, interfere with other control apparatus.
[0024] One embodiment of a processor-based module 34 for implementing the capabilities described herein, shown in FIG. 3 , may include a processor 52 that communicates across a host bus 54 to a bridge 56 and system memory 58 . The bridge 56 may communicate with a bus 60 which could, for example, be a Peripheral Component Interconnect (PCI) bus in accordance with Revision 2.1 of the PCI Electrical Specification available from the PCI Special Interest Group, Portland, Oreg. 97214.
[0025] A microphone 32 input signal may be provided to the audio codec (AC'97) 68 where it may be digitized and sent to memory through an audio accelerator 66 . The AC'97 specification is available from Intel Corporation, Santa Clara, Calif. Sound data generated by the processor 52 may be sent to the audio accelerator 66 and the AC'97 codec 68 and on to the speaker 70 .
[0026] In some embodiments of the present invention, a microphone 82 may be provided in a remote control unit 81 which is used to operate the module 34 . The remote control unit 81 may be attached to the employee via a lapel microphone or headset, as two examples. For example, the microphone input may be transmitted through a wireless interface 79 to the module 34 and its wireless interface 78 in one embodiment of the present invention.
[0027] The bus 72 may be coupled to a bus bridge 62 that may couple to a hard disk drive 64 . The bridge 62 may in turn be coupled to an additional bus 72 , which may couple to a serial interface 76 which drives a wireless interface 78 . The interface 78 may communicate with the remote control unit 81 . A basic input/output system (BIOS) memory 90 may also be coupled to the bus 72 . The interface 78 may communicate with the remote control unit 81 .
[0028] The serial interface 76 may also receive a signal from a sensor interface 86 that is coupled to proximity sensors 42 . In addition, the serial interface 76 may provide an output signal to the window interface 84 which provides window control signals to the motor 28 to operate the window 10 . A hard disk drive 64 or other storage device may store a plurality of software programs 72 , 74 , and 76 . In some embodiments, the processor 52 may provide a timer function so that, after a window 10 is opened, a timer begins. After a set time out, the window may be automatically closed. However, if the sensors 42 provide a signal to the sensor interface 86 , the window may be maintained open because the employee may be using the opened window.
[0029] Referring to FIG. 4 , the employee E may, in one embodiment of the present invention, wear a headset 100 . The headset 100 may include a microphone 104 , which in one mode may be used to communicate with the customer outside of the retail facility. The headset 100 may include earphones 102 to listen to feedback from the customer. A lapel microphone 104 a may be provided in some embodiments. The headset 100 and/or the lapel microphone 104 a may communicate with a battery powered wireless interface 81 .
[0030] The interface 81 may communicate with the module 34 using a wireless link 79 . The wireless link 79 may be infrared based, in one embodiment, or based on radio frequency, as another example. Thus, the employee may interact with a customer outside of the window 10 when the pane 24 is in the open position. In some embodiments, the module 34 may be wirelessly coupled to the window 10 .
[0031] Referring to FIG. 5 , in accordance with one embodiment of the present invention, the window 10 may be controlled in response to spoken commands from the employee. Thus, a check at diamond 110 determines whether or not a speech input has been received. If so, the spoken word is compared to a vocabulary, as indicated in block 112 . In some embodiments the vocabulary may be relatively limited. For example, very simple commands may be recognized, such as “open” or “close.” In other embodiments more extensive vocabularies may be available. For example, a conversational speech system may be implemented which understands a large variety of terms and devines the meaning of the spoken phases in order to control the window 10 .
[0032] A check at diamond 114 determines whether there is a match between the received input and the vocabulary. If so, the window may be operated, as indicated in block 116 , consistent with the received command.
[0033] Referring to FIG. 6 , in accordance with another embodiment of the present invention, the speech/voice control software 74 detects a speech input as indicated at diamond 110 . If no speech input has been received, a check at diamond 120 determines whether a time out has occurred. If so, a check at diamond 122 determines whether the window 10 is open. If it is, a check at diamond 124 determines whether the employee is proximate. This may be done based on inputs from the sensors 42 . If the employee is not proximate, the window 10 may be closed as indicated in block 126 . As a result, once the window 10 has been opened in response to a spoken command, it may be automatically closed after the expiration of a time out period unless, in some embodiments, the employee is proximate to the window.
[0034] If a speech input has been received at diamond 110 and the vocabulary is checked at block 112 . The presence of a match is determined at diamond 114 and the window is operated at 116 , if appropriate.
[0035] At block 118 , voice synthesis may be provided in some embodiments. For example, in some embodiments, it may be desirable to automatically synthesize a statement to the customer as soon as the window opens, such as a welcoming statement or other automated statement that otherwise, necessarily, would be spoken by the employee. This enables the employee to continue to do other tasks while introductory phrases (or other phrases) may be automatically generated by the system. For example, the system may welcome the customer and ask for the customer's order. Only when the order is actually being taken, in some embodiments, need the employee actually begin working with the customer. In some cases the employee may face the customer at all times while still continuing to undertake other duties.
[0036] Referring to FIG. 7 , training software 76 in accordance with one embodiment of the present invention initially prompts the employee for a voice input as indicated at block 130 . The prompt may be on a computer display screen or may be audibly generated as two examples. In response to the prompt, a check at diamond 132 determines whether an input is received from the employee. The input may typically be the command that the employee wishes to speak in order to cause the window 10 to open. Once the input is received, the employee may be asked to repeat the spoken command at block 134 to ensure that a good signal was received. A check at diamond 136 determines whether the first and second spoken commands match sufficiently that a good result may be obtained.
[0037] A check at diamond 138 determines whether or not the employee has previously provided another command. If this is not the first input then the command that was just received is stored as a close window command as indicated in block 132 . Otherwise, the command is stored as an open command and the flow recycles to receive the close command.
[0038] In some embodiments, training the system to recognize the actual employee's voice may reduce errors. That is because the employee can provide actual samples of his voice, the system need not recognize spoken commands from a wide variety of different people. This may improve the accuracy of the system and make it more user friendly to some users who can provide any word they wish for the open and close commands.
[0039] Referring now to FIG. 8 , a wirelessly and remotely controllable base station 152 may receive control signals from a wearable wireless unit 150 . The wearable wireless 150 may be worn by a service employee. The service employee may operate the wearable wireless unit 150 to send wireless signals to the base station 152 . In some embodiments, the wireless signals may be sent by radio frequency or infrared signals. For example, the wearable wireless unit may initiate radio frequency signals in accordance with the Bluetooth standard as one embodiment. In some embodiments, the base station may be intimately associated with the window 10 so as to operate a motor associated therewith. In other words, the base station may be implemented as part of the window interface 84 in one embodiment of the present invention.
[0040] Referring to FIG. 9 , in accordance with one embodiment of the present invention, a service employee may wear a headset 154 . The headset 154 may include an earphone 164 to hear signals provided from a remote drive through station by customers. For example, in connection with a drive-up station, the customer may speak into a microphone and the signal may be transmitted to the headset 154 to be heard through the earphone 164 . To this end, a wireless antenna 168 may be included. The wireless antenna may communicate by a wire 162 with a battery pack and transceiver (not shown) but attached to a belt 158 .
[0041] Also connected to the headset 154 may be a microphone 166 , into which the employee may talk and signals may be generated to be wirelessly transmitted to a customer.
[0042] The employee may wear a harness including shoulder straps 162 and a chest encircling strap 158 . Mounted on the strap 158 , in a position to be actuated by the internal surfaces of the employee's elbow E, is a push button 156 . Namely, when the employee rotates his elbow inwardly in the direction indicated by the arrows F, the button 156 may be operated to either open or close the window 10 . In one embodiment, if the window is closed, when the button 156 is operated the window opens and, if the window is open, when the button 156 is operated, the window closes.
[0043] In some embodiments, the belt 158 may be worn higher than the normal clothing belt B so that it is in line to be operated by the service employee's elbow E.
[0044] As a result, the employee may have his hands filled, for example, holding a cup 0 in his hand H, and still may be able to remotely open and close the service window 10 .
[0045] When the push button 156 is operated, a signal is transmitted through conductors (not shown) to the transceiver (not shown) and on to the headset 154 , which sends a signal wirelessly over the antenna 168 to a base station 152 associated with the window 10 in one embodiment. In another embodiment, a transmitter (not shown) may directly transmit the window control signal without involving the headset 154 . The base station 152 may include the interface 84 which generates motor control signals to operate the service window 10 .
[0046] While an embodiment is depicted in which a push button operator 156 is positioned on the employee's side at a position raised with respect to the belt B, those skilled in the art will appreciate other embodiments. However, it may be particularly advantageous, in some embodiments, to enable hands free operation of the window and to enable remote operation of the window.
[0047] One reason that remote operation may be desirable is that it can save time. Instead of requiring the employee to approach the window and then operate the window, consuming additional time, the service employee may operate the window in route to a position proximate to the service window 10 so that, by the time the employee arrives, the window is already fully open.
[0048] Given the very large number of service operations and the desire to maintain the service window 10 in the closed position when not in use, the time savings may be significant. These time savings may also result in better service to customers.
[0049] While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
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A service window may be operated under hands free user remote control. For example, a service window of the type used in fast-food restaurants, may be opened or closed in response to remote control signals.
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FIELD OF THE INVENTION
[0001] This invention relates to a solar energy collection system, and more particularly to a support system for an array of photovoltaic panels and method of assembling the same. The invention includes a bi-directional span of support members, including a profiled support rail having a longitudinal T-slot channel adapted to receive the head of a bolt for adjustable attachment to a support joist, and the support rail may also include a longitudinal C-slot channel for retaining electrical wiring.
BACKGROUND OF THE INVENTION
[0002] A standard photovoltaic panel array includes a plurality of solar panels optimally arranged for converting light incident upon the panels to electricity. Various support systems are used for attachment to roofs, free-field ground racks or tracking units. Typically, these support systems are costly, labor intensive to install, heavy, structurally inferior and mechanically complicated. For example, a support system generally includes off-the-shelf metal framing channels having a C-shaped cross-section, such as those sold under the trademarks UNISTRUT™ or BLIME™, improvised for use as vertical and horizontal support members. The photovoltaic panels are directly secured to the support members and held in place by clips. The clips serve as hold-down devices to secure the panel against the corresponding top support member in spaced-relationship. The clips are positioned and attached about the panel edges once each panel is arranged in place.
[0003] For a free-field ground rack system as shown in FIG. 1 , support elements, such as I-beams, are spaced and securely embedded vertically in the ground. Tilt brackets are installed at the top of each I-beam, and each tilt bracket is secured to the I-beam such that a tilt bracket flange extends above the I-beam at an angle as best seen in FIG. 2A . As shown in this case, two UNISTRUT™ joists span the tilt brackets and are secured thereto. As seen in FIG. 2B , UNISTRUT™ rails are positioned across and fastened to the horizontal joists. To secure each rail to the corresponding horizontal joists, a bolt through a bolt hole made in the rail sidewall attaches to a threaded opening in a transverse nut-like plate slideably mounted inside the channel of the UNISTRUT™ joist, so that the nut-like plate engages and tightly secures against the upper flange of the joist's C-channel as seen in FIG. 2A . Importantly, the width of the plate is slightly less than the width of the channel, so that the plate can be slideably adjusted in the channel without the plate rotating therein.
[0004] Once the bi-directional span is assembled, each solar panel is positioned and top and bottom clips are secured to each rail about the perimeter of each panel, to hold the panel such that the center of each panel is between two rails.
[0005] Another example of a support system is shown in U.S. Pat. No. 5,762,720, issued to Hanoka et al., which describes various mounting brackets used with a UNISTRUT™ channel. Notably, the Hanoka et al. patent uses a solar cell module having an integral mounting structure, i.e. a mounting bracket bonded directly to a surface of the backskin layer of a laminated solar cell module, which is then secured to the channel bracket by bolt or slidably engaging C-shaped members. Other examples are shown in U.S. Pat. No. 6,617,507, issued to Mapes et al., U.S. Pat. No. 6,370,828, issued to Genschorek, U.S. Pat. No. 4,966,631, issued to Matlin et al., and U.S. Pat. No. 7,012,188, issued to Erling.
[0006] Notably, existing support systems require meticulous on-site assembly of multiple parts, performed by expensive field labor. Assembly is often performed in unfavorable working conditions, i.e. in harsh weather and over difficult terrain, without the benefit of quality control safeguards and precision tooling.
[0007] Spacing of the photovoltaic panels is important to accommodate expansion and contraction due to the change of the weather. It is important, therefore, that the panels are properly spaced to maximum use of the bi-directional area of the span. Different spacing may be required on account of different temperature swings within various geographical areas. It is difficult, however, to precisely space the panels on-site using existing support structures without advanced technical assistance. For example, with the existing design described above (with reference to FIGS. 2A and 2B ), until the rails are tightly secured to the horizontal joist, each rail is free to slide along the horizontal joists and, therefore, will need to be properly spaced and secured once mounted on-site. Further, since the distance between the two horizontal joists is fixed on account of the drilled bolt holes through the rails, it is preferred to drill the holes on-site, so that the horizontal joists can be aligned to attach through the pre-drilled attachment holes of the tilt bracket.
[0008] A need exists, therefore, for a low-cost, uncomplicated, structurally strong support system and method, so as to optimally position and easily attach the plurality of photovoltaic panels, while meeting architectural and engineering requirements.
[0009] To accomplish the foregoing and related objectives, this invention provides a support system that can be assembled off-site to precise engineering specifications, then folded and shipped to the installation site. At the site location, the support system is easily attached to the roof, rack or tracking unit, then unfolded, so that panels can be properly secured without waste of space, time or materials. Special gravity clips can be used to quickly and easily secure each panel in place, whereby the panel's own weight is used to hold it to the support system.
SUMMARY OF THE INVENTION
[0010] An array of photovoltaic solar panels is supported in rows and possibly columns spaced from one another using a bi-directional span of support members. The support members include a plurality of horizontal support joists and vertical support rails to be braced at an incline. Each support rail is tubular, having a generally rectangular cross-section with an upper wall section having a thickness, and lower wall section having a longitudinal T-slot channel for acceptance of the head of a bolt for adjustable attachment with the respective support joist. Also, the support rail preferably includes a C-slot channel for retaining electrical wires. Gravity clips are preferably used to hold the panels to the support rails. The clips are either single-panel clips with a Z-shaped cross-section, or two-panel clips with a U-shaped cross-section, and are secured to a corresponding support rail through a threaded hole in a top wall of the support rail that receives a fastener, such as a self-threading screw or bolt.
[0011] In accordance with one aspect of the invention, each support rail is attached to the support joists by bolts, wherein the head of each bolt can slide in the T-slot channel of the respective rail. The shank of the bolt passes through and is secured to the respective support joist using a nut or another fastener type to form the bi-directional span. Notably, with the bolts torqued tight, the bi-directional span can be easily folded to reduce space for shipping. Before folding, the gravity clips can be installed in the proper location by drilling and tapping threads in each opening to accept a threaded fastener.
[0012] Preferably, solar panels are not shipped while attached to the support system, but they are easily installed once the support system is unfolded and secured in place at its final site location. The bolts securing the support joists and support rails are checked for tightness, and the solar panels are arranged and secured along their perimeters by the gravity clip members, i.e. between saw-tooth profiled gaskets to protect the panel surfaces.
DESCRIPTION OF THE DRAWINGS
[0013] Having generally described the nature of the invention, reference will now be made to the accompanying drawings used to illustrate and describe the preferred embodiments thereof. Further, these and other advantages will become apparent to those skilled in the art from the following detailed description of the embodiments when considered in light of these drawings in which:
[0014] FIG. 1 is a perspective view of an assembled conventional field ground rack support system for securing a plurality of solar panels;
[0015] FIG. 2A is a side view of a tilt bracket mount with prior art C-shaped sectional channels secured back-to-back to form joists to which vertical rails of FIG. 2B are secured;
[0016] FIG. 2B is a side view of the prior art vertical rails, each with a C-shaped sectional channel;
[0017] FIG. 3 is a perspective view of a support system of the instant invention showing solar panels arranged in a column and in spaced relationship thereon;
[0018] FIG. 4A is a top plan view of the bi-directional span of the assembly of the instant invention in the open position;
[0019] FIG. 4B is an end elevational view of the bi-directional span of the assembly shown in FIG. 4A ;
[0020] FIG. 5 is a top plan view illustrating the bi-directional span of the assembly in the folded position;
[0021] FIG. 6 is a side elevation and partial sectional view that shows the horizontal support joists and tubular support rail with a single-panel clip;
[0022] FIG. 7 is an end elevation and partial sectional view perpendicular to that shown in FIG. 6 ;
[0023] FIG. 8 is a cross-sectional perspective view of the module support rail;
[0024] FIG. 9 is a cross-section of said support rail;
[0025] FIG. 10 is a sectional elevation view showing a solar panel mounted between a two-panel clip and a single-panel clip;
[0026] FIG. 11 is a sectional elevation view showing a panel being fitted within a gasket of the two-panel clip and arranged to be fitted into a single-panel clip gasket; and
[0027] FIG. 12 is a sectional elevation view showing a panel fitted within the gasket of the two-panel clip, having rearmost retaining ribs, a fulcrum ridge and a saw-tooth profile.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] With reference to the drawings, a support system for a photovoltaic array of solar panels 12 known in the prior art includes a free ground rack structure having spaced vertical support elements 14 extending from the ground. The support system 10 of FIG. 1 shows only two vertical support elements 14 , although multiple support elements may be used to accommodate a longer array of solar panels. Notably, the support system can also be mounted to a roof or tracking unit. Each of the support elements 14 for the free-field ground rack is preferably an I-beam securely embedded and vertically aligned in the ground, as is well known in the art.
[0029] A pair of horizontal, C-shaped support joists 11 , 13 is mounted at the upper ends of the support elements 14 by tilt bracket mounts 16 . Thus, the vertical support elements 14 are spanned by the joists 11 , 13 . When there are additional arrays with additional support elements 14 , they can be spanned by multiple joists attached at their ends, or the joists 11 , 13 can be longitudinally extended to span all of the support elements 14 in one, unbroken length.
[0030] Vertical rails 15 , arranged perpendicular to the joists 11 , 13 , are secured to the joists to produce a two-dimensional span, on which the panels are supported. FIG. 2A illustrates conventional joists 11 , 13 secured to tilt bracket mounts 16 by back-to-back channels 17 , 18 , with each channel having a C-shaped cross-section. Similarly, each conventional rail 15 is secured to the joists 11 , 13 by bolts through a corresponding wall of its C-channel 19 , as best seen in FIG. 2B .
[0031] In accordance with a preferred embodiment of this invention, FIG. 3 shows a support system 10 for a photovoltaic array of solar panels 12 , attached to the same, conventional vertical support elements 14 . The support system 10 in this case, however, includes a bidirectional span of horizontal joists 20 and vertical support rails 30 - 1 through 30 - n. Each support rail 30 - n in this design is preferably an aluminum extrusion, although, in the alternative, the rail may be made of roll-formed steel. Preferably, each support rail 30 - n has a tubular body 31 having a generally rectangular cross-section with an upper wall section 36 and lower wall section 32 defined between spaced side walls 35 as best seen in FIGS. 8 and 9 . The upper wall section 36 has a flat top surface 37 and upper wall of varied thickness, preferably having its thickest portion 38 in the center. This thicker center portion 38 is for added strength when fastening the single-panel clips 100 , 100 ′ and two-panel clip 120 (described below). Strength is also built into each support rail 30 - n using a thicker lower wall section 32 . The lower wall section 32 includes a longitudinal T-slot sectional channel 33 and, preferably, a longitudinal C-slot sectional channel 34 .
[0032] In this embodiment, the length of each rail 30 is governed by the height of the individual solar panels 12 and the number of solar panels per column of panels. Each support rail 30 - 1 through 30 - n is attached to the support joists 20 by bolts 40 , wherein the head 42 of each bolt is slidably accommodated in the corresponding T-slot channel 33 of the respective rail. The shank 43 of the bolt 40 passes through and is secured to the respective support joist 20 using a nut 45 or other type fastener to form the bi-directional span. Notably, with the nuts 45 and bolts 40 tightened securely, the bi-directional span can be folded to reduce space for shipping, as shown in FIG. 5 . Each horizontal support joist 20 is separated from the corresponding vertical support rail 30 - n by nonconductive separation washers 24 , preferably made of nylon, in order to prevent galvanic interaction between unlike materials. The nylon washer 24 is preferably about ⅛ th inch, thick although other materials and thicknesses may be used.
[0033] Once the rails 30 are secured to the support joists 20 , the solar panels 12 are fastened to the rails using gravity clips 100 , 100 ′, 120 . As shown in FIGS. 3 , 10 , 11 and 12 , three types of clips are preferably used, i.e. end or single-panel clips 100 , 100 ′ and an intermediate or two-panel clip 120 . The single-panel clips 100 , 100 ′ have a generally Z-shaped profile with a base portion 110 and first wall 112 . Clip 100 has a first flange 114 and uses an unfulcrumed U-shaped gasket 130 . Clip 100 ′, on the other hand, has a first flange and gasket that substantially match that of flange 124 and gasket 131 described in detail below.
[0034] The two-panel clip 120 is generally U-shaped having a first extended flange 114 , a second extended flange 124 , a first wall 112 , second wall 122 and a base portion 110 , and uses two different gaskets 130 , 131 . Generally, both gaskets 130 , 131 have a U-shaped cross-section with a fold 138 , upper and lower contact surfaces, 132 , 134 , respectively, with a plurality of ribs 140 , i.e. saw-tooth profiles, and a back wall 136 .
[0035] The fulcrumed U-shaped clip gasket 131 further includes resilient, rearmost retaining ribs 142 , designed to contact a top peripheral side 143 of the panel 12 to push and hold the panel downward into the clip below. Notably, there may be one retaining rib 142 extending from the upper contact surface 132 and one extending from the lower contact surface 134 (as shown in FIGS. 10 through 12 ), or, in the alternative, there may be just one large rib extending from either the upper or lower contact surfaces. Still further, retaining rib 142 may extend from the back wall 136 , in which case the retaining rib 142 may be replaced with a spring to provide resiliency.
[0036] The lower contact surface 134 of the fulcrumed gasket 131 further includes a fulcrum point 144 , i.e. an extended elongated ridge, which forces against the solar panel 12 toward the upper contact surface 132 and second clip flange 124 .
[0037] In use, the bottom portion of the two-panel clip 120 holds the top peripheral edge of the lower solar panel 12 aligned with the other solar panels in the respective column of panels. As best seen in FIGS. 10 and 11 , the bottom portion of clip 120 includes a second clip flange 124 , which is longer than the opposing first clip flange 114 , which holds the bottom of an uppermost solar panel 12 in the same column. The top or first clip flange 114 of the two-panel clip 120 is preferably the same length as that of the flange of the bottom mounted single-panel clip 100 , i.e. having the same U-shaped unfulcrumed clip gasket 130 used therewith. Preferably, the length of longer clip flange 124 is at least twice the length of the shorter first flange 114 , so that the solar panel 12 can be inserted first under flange 124 , pivoted on fulcrum point 144 and then inserted under flange 114 , whereby flanges 114 , 124 and gravity hold the panel 12 firmly in place once set in position.
[0038] The difference between single-panel clips 100 and 100 ′ is that clip 100 ′ is the first clip at the top of each support rail 30 - n; while clip 100 is the last clip, i.e. at the bottom of each support rail 30 - n. Since single-panel clip 100 ′ is the top clip of each support rail, it has a fulcrumed U-shaped gasket, identical to the fulcrumed gasket 131 , to accommodate its extended flange profile (identical to flange 124 ). This is necessary since the top single-panel clip 100 ′ forces against the top perimeter side 143 of the uppermost solar panel 12 , aligned with the other solar panels in the respective column of panels, to push the bottom edge of the panel 12 into the top portion of the two-panel clip 120 therebelow. Therefore, the profile of clip 100 ′ substantially matches that of the bottom portion of the two-panel clip 120 to fit and secure the top perimeter edge of each solar panel therein.
[0039] Both of the clip gaskets 130 , 131 include a T-shaped engagement protuberance 137 for slidable registration and attachment via a complementary, somewhat T-shaped retaining groove 117 formed between the walls 112 , 122 and their respective flanges 114 , 124 . Gaskets 130 , 131 are used with each clip 100 , 100 ′, 120 to protect the front and back edges 143 of each solar panel 12 . Each gasket 130 , 132 is preferably extruded with the T-shaped mounting protuberance 137 .
[0040] Preferably, the gaskets 130 , 131 are made of a material which is physically and chemically stable, and preferably electrically nonconductive. Furthermore, the gaskets 130 , 131 should be of an electrically resistant material and have good elasticity upon compression. Suitable materials, which can be employed include, but are not limited to, neoprene, butyl rubber, ethylene-propylene diene monomer (EPDM), chlorinated polyethylene (CPE) and a polytetrafluoroethylene (PTFE) material such as GORTEX® (a trademark of W.L. Gore & Associates, Inc.), or TEFLON® (a trademark of E.I. DuPont de Nemours & Company).
[0041] This support system 10 allows for off-site assembly to precise engineering specifications, in that, once the support members are assembled, the bi-directional span can be folded, as shown with reference to FIG. 5 , transported to the installation site, positioned and secured to the roof, rack or tracking unit via the tilt bracket 16 while still in the folded position, and unfolded to the position of FIG. 3 .
[0042] Specifically, the method of assembling this support system for an array of photovoltaic panels 12 in columns and rows, includes the steps of building the bi-directional span by attaching support members, i.e. support joists 20 and support rails 30 - n, using a plurality of attachment bolts 40 and nuts 45 . The top surface 37 of each rail 30 - n must be unobstructed for the solar panels to secure against. As previously described, each support rail 30 - n preferably has a substantial rectangular cross-section with an upper wall section 36 and lower wall section 32 . Each support system can be easily built and adjusted to various engineering specifications, in that the longitudinal T-shaped sectional channel 33 in the lower wall section 32 is adapted to adjustably receive the heads 42 of attachment bolts 40 . Bolts 40 attach each vertical support rail 30 - n, passing through one of the horizontal support joists 20 . The T-shaped slotted channel 33 permits the bolt 40 to be placed at any location along the length of the channel and through the horizontal support joist 20 as required.
[0043] The perimeter, gravity clips 100 , 100 ′, 120 can be pre-positioned and attached to the upper wall section 36 of the support rails 30 by a self-threading bolt 145 secured to thick portion 38 and whose head engages base portion 110 of the clip. The perimeter clips 100 , 100 ′, 120 can be positioned and attached to the upper wall section 36 of the support rails 30 off-site to proper engineering specifications, so as to provide the necessary spacing for the columns and rows of the photovoltaic panels 12 of the array, without wasting space and time.
[0044] Once the perimeter clips 100 , 100 ′, 120 and rails 30 - n are attached to the support joists 20 as described above, the bi-directional span can be reduced in size by folding the support rails relative to the support joists 20 . The folded span can be easily shipped to the location for installation, then unfolded and secured to the roof, free-field ground rack or tracking unit for attachment of the photovoltaic panels 12 via the pre-positioned, attached and properly spaced perimeter clips 100 , 100 ′, 120 .
[0045] Specifically, the preferred method to assemble the bidirectional span is to align the first horizontal support joist 20 and insert a bolt 40 in spaced, pre-drilled holes 44 passing through the support joist 20 with the bolt head 42 at the top of the joist and a hex nut 45 at the bottom. The separation washer 24 is included near the bolt head. The process is repeated for the second horizontal support joist 20 .
[0046] Next, a single vertical support rail 30 - 1 is aligned with the head 42 of the first bolt 40 located in position along the first horizontal support joist 20 . The bolt head 42 is lifted, separated from the separation washer 24 , and slid into the T-slot channel 33 in the vertical support rail 30 . This step is then repeated for the second horizontal support joist 20 . The end of the first vertical rail 30 - 1 is then aligned with a side wall of the first horizontal joist 20 , and the hex nuts 45 are torqued snug. Using a machinist square, the horizontal support joist 20 is made perpendicular to the vertical support rails 30 - 1 . The other vertical rails 30 - 2 through 30 - n are assembled and secured in like fashion.
[0047] As previously stated, bolts 40 and hex nuts 45 are used to securely fasten the horizontal support joists 20 to the corresponding vertical support rails 30 - 1 through 30 - n. Preferably, each hex nut 45 has a nylon insert. The nylon insert retains torque pressure of the fastener during shipping and prevents the support rails 30 - n from loosening from the support joists 20 when folded and unfolded. Notably, on account of the separation washers 24 and the nylon hex nuts 45 , the rails 30 - n can pivot relative to the horizontal support joists 20 without any significant loosening. Grasping the ends of both horizontal joists, the first horizontal joist 20 is pushed away relative to the second horizontal joist 20 , permitting the assembly to fold into a condensed, folded form for shipping.
[0048] It is important to note for assembly and shipping purposes, that the tubular body form 31 , varied wall thickness 38 , and channels 31 , 32 substantially reduces the weight of the module rails 30 - n, and, therefore, the overall weight of the assembled system (in comparison to the prior art). Yet, the structural strength is enhanced.
[0049] After shipping the assembly to the field for installation, it is unpackaged, and the bottom-most horizontal support joist 20 is mounted and secured to the vertical support element 14 via the tilt bracket mounts 16 . Then, grasping the end of top-most horizontal support joist 20 , it is pushed to unfold and realign mutually parallel to the other support joist, and perpendicular to the vertical support rails 30 . The space between the horizontal support joists 20 , can be adjusted (if needed) by sliding the joists along the rails (via their T-slot channels), so that the spacing of the joists 20 precisely align with and attach to the tilt bracket mounts 16 . In contrast, it is not possible to easily space the joists 11 , 13 in the conventional design shown in FIGS. 2A and 2B along its several conventional rails 15 , since the spacing therebetween is fixed by the drilled bolt holes made in rails 15 through the side wall of channels 19 .
[0050] Once the assembly of this invention is unfolded, the top-most horizontal support joist 20 is secured to the tilt bracket mounts 16 . Then, using a machinist square or similar setup fixture, the spacing and perpendicular relationship of the vertical support rails 30 are checked relative to the side wall of the bottom horizontal support joist 20 and adjusted (if needed). The hex nuts 45 are also checked to assure that they continue to be snug after shipping and installation. And finally, with the expanded bi-directional span properly positioned and secured to the support elements 14 , each solar panel 12 is fixed in place by inserting the top of the panel into its top perimeter clips 100 ′ or 120 , then pivoted about the respective gasket fulcrums 144 , to fit the panel's bottom edge into corresponding bottom perimeter gravity clips 100 , 120 , as best seen in FIGS. 10 through 12 . To finish the installation, wires are tucked away in the corresponding C-shaped slotted channels 34 .
[0051] While the invention has been particularly shown and described with reference to the specific preferred embodiments, it should be understood by those skilled in the art that various exchanges in form and detail may be made therein without department from the spirit and scope of the invention as defined by the appended claims.
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An array of photovoltaic panels is supported in rows and columns spaced from one another using a foldable bi-directional span of support members. The support members include a plurality of support joists and support rails braced at an incline. Each support rail is tubular and generally rectangular, having a lower wall section with a T-slot channel for acceptance of the head of a bolt for adjustable attachment with the support joist. Also, the support rail may have a C-slot channel for retaining electrical wires. Clips are used to secure each panel to upper wall portions of underlying support rails. Each clip has a generally U-shaped gasket and is retained to a corresponding support rail through a threaded hole in a top wall of the support rail that receives a bolt or similar threaded fastener.
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FIELD OF THE INVENTION
The present invention relates to a rocket engine comprising a combustion chamber in which a fluid (liquid or gaseous) fuel, for example hydrogen, and a fluid (liquid or gaseous) oxidizer, for example oxygen, are burnt, said combustion chamber being connected to a divergent nozzle through which the gases resulting from the combustion escape.
BACKGROUND OF THE INVENTION
In known rocket engines of this type, because of the very high temperatures (of the order of 3300° C.) reached in said combustion chamber, the structure of the walls is particularly complex with networks of ducts for circulating a cooling fluid which, incidentally, may be said fuel itself. Examples of known walls are described, for example, in documents FR-A-2 773 850, FR-A-2 774 432, FR-A-2 791 589. In addition, the structure of said walls is not uniform but by contrast varies along the axis of the engine, according to the temperature at that point. Finally, particularly on account of the fact that the fuel is used as a cooling fluid and can circulate in the two opposite directions, these known engines require complex fuel supply manifolds.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome these disadvantages by allowing the production of a simple rocket engine, without a complex manifold, and having a very limited number of parts.
To this end, according to the invention, the rocket engine comprising a combustion chamber in the heart of which a fuel and an oxidizer are burnt and which is connected, by a throat, to a divergent nozzle through which the gases resulting from said combustion escape, said heart being supplied with oxidizer via its opposite end to said throat and being surrounded by a porous skin of thermostructural composite which receives fuel on its opposite outer side to said heart, some of this fuel being introduced into said heart through said porous skin, is notable in that said proportion of the fuel introduced into said heart through said porous skin constitutes the fuel supply to said engine and in that the proportion of said fuel not passing through said porous skin is directed toward said throat to cool it.
Thus, by virtue of the present invention, there is obtained a rocket engine that is simple, light in weight, can have just a few parts and can be produced with ease.
It will be noted that document WO-99/04156 describes a rocket engine comprising a combustion chamber in the heart of which a fuel and an oxidizer are burnt and which is connected, by a throat, to a divergent nozzle through which the gases resulting from said combustion escape, said heart being supplied with oxidizer via its opposite end to said throat and being surrounded by a porous skin of thermostructural composite which receives fuel on its opposite outer side to said heart, some of this fuel being introduced into said heart through said porous skin.
However, it must be pointed out that, in the rocket engine of document WO-99/04156, the proportion of fuel introduced into the heart through the porous skin is low and intended to cool the wall of said heart by seepage and that the proportion of fuel not passing through the porous skin is returned to fuel injectors. By contrast, in the rocket engine according to the present invention, the proportion of the fuel introduced into said heart through said porous skin is high and constitutes the fuel supply of said engine, whereas the proportion of said fuel not passing through said porous skin is directed toward said throat to cool it.
In addition, this earlier document anticipates the production of fuel circulation ducts in said porous skin, something that the present invention avoids through the novel structures proposed for the combustion chamber.
It will also be noted that, in the rocket engine of the invention, use is made of thermostructural composites—with a carbon matrix or ceramic matrix—not only because of their well-known mechanical and thermal resistance properties, but also for their intrinsic porosity which is generally rather considered to be a disadvantage (see patent U.S. Pat. No. 5,583,895).
Thanks to the excellent mechanical and thermal resistance properties of thermostructural composites, the rocket engine according to the present invention may have a very low mass with respect to known engines. Thanks to the porosity of these composites, a simple porous skin which nonetheless has good resistance to heat can be produced. Of course, the porosity of said skin may be adapted, in a known way, to any desired value when the matrix of the composite of which it is made is densified.
As a preference, said porous skin forms part of a first monolithic piece of thermostructural composite comprising two skins of composite spaced apart from one another leaving between them an intermediate space and joined together by a plurality of threadlike spacers of composite, passing across said intermediate space but not in any way impeding the free circulation of a fluid in said intermediate space.
Thus, if in the rocket engine of the present invention, said divergent nozzle is arranged in the continuation of said combustion chamber, on the opposite side of said throat to said combustion chamber:
said first monolithic piece maybe cylindrical and arranged coaxially with respect to the longitudinal axis of said engine so that one of said skins is an inner skin whereas the other is an outer skin; said oxidizer maybe introduced into the cylindrical volume delimited by said inner skin on the opposite side to said nozzle, this volume forming the heart of said combustion chamber; and said fuel maybe introduced into said intermediate space, which therefore has an annular cross section, also on the opposite side to said nozzle, so that said inner skin acts as a porous skin for the introduction of at least some of said fuel into the heart of said combustion chamber.
Said outer skin of said first monolithic piece may be completely sealed against liquids and against gases, for example by applying an appropriate coating.
It is advantageous for said first monolithic piece to have an inside diameter greater than that of said throat and for the annular orifice of said intermediate space, arranged on the same side as said nozzle, to lie facing the convergent part of said throat.
Thus, it is possible easily to use a small proportion of the fuel, introduced into said intermediate space of annular cross section but not passing through said inner skin toward the heart, to cool the region of the throat.
Said nozzle may comprise, beyond said throat, a sheath able to house said first monolithic piece.
Thus, the entity consisting of the nozzle, the throat and the sheath therefore forms a second monolithic piece, into which said first monolithic piece is inserted. This second monolithic piece may, for example, be made of metal. However, for the reasons mentioned hereinabove, it is advantageous for it, just like said first piece, also to be made of thermostructural composite. In this case, said second monolithic piece may advantageously constitute a continuation of said outer skin of said first monolithic piece, this continuation forming an integral part of said outer skin. The result of this then is that said first and second monolithic pieces form just one piece.
In an alternative form of embodiment of the rocket engine according to the present invention, said combustion chamber is arranged in said divergent nozzle near the vertex thereof.
In this case it is advantageous for:
said combustion chamber to comprise:
an inner first monolithic piece of composite, of cylindrical shape, arranged coaxially with respect to the axis of the engine and having an inner skin and an outer skin separated by an intermediate space, of annular cross section; and an outer first monolithic piece of composite, of cylindrical shape, arranged coaxially with respect to said axis and having an inner skin and an outer skin separated by an intermediate space, of annular cross section, said outer first piece surrounding said inner first piece, so as to form between them an annular heart of combustion;
said inner and outer first pieces to form between them and the vertex of said divergent nozzle an annular passage for communication with said nozzle; said oxidizer is introduced into said annular heart of combustion from the opposite side to said vertex of the nozzle; and said fuel is introduced into said intermediate spaces, of annular cross section, of said inner and outer first pieces also from the opposite side to said vertex.
Thus, in this embodiment, the fuel is introduced into said annular combustion heart through the outer skin of said inner first piece and through the inner skin of said outer first piece. The combustion gases then pass from said annular combustion chamber to the divergent nozzle through said annular communication passage that forms a throat. The fuel passing through the outer skin of the outer first piece is able to cool the divergent nozzle near said annular communication passage. If need be, the inner skin of the inner first piece is sealed against liquids and against gases.
Advantageously, the vertex of said divergent nozzle is pierced with an orifice and the collection of said inner and outer first pieces is secured to said nozzle by a third monolithic piece of composite in the shape of a horn.
As a preference, said combustion chamber is supplied with fuel via a dome-shaped piece arranged on the opposite side of said combustion chamber to the vertex of the nozzle and the convex wall of which faces toward said nozzle and is made of thermostructural composite.
BRIEF DESCRIPTION OF THE DRAWINGS
The figures of the attached drawing will make it easy to understand how the invention may be embodied. In these figures, identical references denote similar elements.
FIG. 1 depicts, schematically and in axial section, a first exemplary embodiment of the rocket engine according to the present invention.
FIGS. 2A to 2 F schematically illustrate one embodiment of the combustion chamber of the engine of FIG. 1 .
FIGS. 3A to 3 D schematically illustrate, on a larger scale, the steps in the method for moving on from the state of FIG. 2E to the state of FIG. 2F , FIG. 3A corresponding to the section line IIIA—IIIA of FIG. 2 E and FIG. 3D to the section line IIID—IIID of FIG. 2 F. In these FIGS. 3A to 3 D, the two portions of each stitch are depicted very far apart, for the purpose of clarity.
FIG. 4 schematically illustrates one embodiment of the engine of FIG. 1 , comprising the combustion chamber of FIG. 2 F.
FIG. 5 depicts, schematically and in axial section, a second exemplary embodiment of the rocket engine according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The exemplary embodiment of the rocket engine I, according to the present invention and depicted schematically in FIG. 1 , comprises a combustion chamber 1 and a divergent nozzle 2 connected to one another by a throat 3 . The longitudinal axis of the engine I bears the reference Z—Z.
The combustion chamber 1 comprises an outer wall 4 , of which the part 4 A, opposite the nozzle 2 , is roughly cylindrical, whereas the part 4 B of the outer wall 4 , arranged at the same end as said nozzle 2 , is convergent to connect with the throat 3 . Thus, the outer wall 4 , the throat 3 and the nozzle 2 are in continuity and able to constitute a single piece.
The combustion chamber 1 additionally comprises a porous inner wall 5 , the axis of which is coincident with the axis Z—Z and which is arranged inside the outer wall 4 , forming with the latter a cylindrical intermediate space of annular cross section 6 . The porous inner wall 5 is also roughly cylindrical, and its diameter D is greater than the diameter d of the throat 3 . Facing the convergent part 4 B of the outer wall 4 , the inner wall 5 has a convergent part 5 B which, with said convergent part 4 B, determines an annular passage 7 forming a restriction for the annular space 6 .
In the example depicted, said combustion chamber 1 consists, at least in part, of a first monolithic piece of thermostructural composite, in which said porous inner wall 5 consists of a skin made of composite. Likewise, said divergent nozzle 2 may constitute or form part of a second monolithic piece of thermostructural composite. Said first and second monolithic pieces, which may each comprise part of the throat 3 or alternatively just one of which comprises said throat 3 , are secured together or made as a single monolithic piece, to form the rocket engine I.
In the combustion chamber 1 , combustion takes place inside the cylindrical volume C delimited by the porous inner wall 5 and forming the heart of said combustion chamber. A stream of oxidizer, essentially oxygen, is introduced into the heart C through the end 5 A of said inner wall 5 which is the opposite end to the nozzle 2 , as illustrated by the arrows 8 . A stream of fuel, essentially hydrogen, is introduced into the annular intermediate space 6 through the opposite end 6 A thereof to the nozzle 2 , as is illustrated by the arrows 9 . Thanks to the appropriate porosity of the inner composite wall 5 and to the restriction formed by the passage 7 , most of the fuel introduced into the annular space 6 passes through said inner composite wall 5 and enters the inside of the heart C—as indicated by the arrows 10 —where it is burnt, thanks to the addition of the oxidizer (arrows 8 ).
The gases resulting from the combustion escape from said heart C through the end 5 B of the wall 5 , the opposite end to the end 5 A, and pass into the nozzle 2 , passing through the throat 3 , as illustrated by the arrows 11 .
Furthermore, a small portion of the fuel introduced into the annular intermediate space 6 (arrows 9 ) passes through the annular passage 7 , as illustrated by the arrows 12 , cooling the part 5 B of the inner wall 5 , the part 4 B of the outer wall 4 and the throat 3 . At this throat, fuel passing through the convergent annular passage 7 mixes with the combustion gases (arrows 11 ).
FIGS. 2A to 2 F, 3 A to 3 D and 4 schematically illustrate one embodiment, in the form of composite, of the engine I of FIG. 1 .
To produce it, the starting point is to produce, for example out of a synthetic foam material through which a needle can pass, a former 20 (see FIG. 2A ) exhibiting the interior shape of the inner porous wall 5 , including the convergent part 5 B. Then, any known method (winding, weaving, etc.) is used to apply to this former 20 a structure 21 of high-strength fibers such as fibers based on carbon or on silicon carbide, which structure is intended to form a fibrous framework for said inner wall 5 (see FIG. 2 B). Next, an annular core 22 , for example made of a polystyrene foam not impregnable by the resins intended to form the composite matrices and representative of the annular intermediate space 6 , including the passage 7 , is applied to the fibrous structure 21 (see FIG. 2 C). The material of the core 22 can be pierced by a needle and removed thermally.
A structure 23 of high-strength fibers (C, SiC, etc.) is applied to the annular core 22 , this structure being intended to constitute a fibrous framework for at least part of said outer wall 4 (see FIG. 2 D).
As shown in FIG. 2E and , on a larger scale, in FIG. 3A , the fibrous structure 21 , the annular core 22 and the fibrous structure 23 are joined together by stitching without knotting of a continuous filament 24 , itself consisting of a plurality of high-strength fibers (C, SiC, etc.). The continuous filament 24 forms portions 25 , 26 passing through the elements 21 , 22 , 23 and connected alternately to one another by bridges 27 applied to the fibrous structure 23 and by loops 28 penetrating the former 20 .
After this stitching operation, the former 20 is removed and the loops 28 are knocked over and pressed against the fibrous structure 21 to form masses 29 (see FIG. 3 B), then the collection of fibrous structures 21 and 23 is impregnated with a curable resin that is relatively low in viscosity and possibly diluted, for example with alcohol. Impregnation is preferably performed under vacuum, so that said resin not only penetrates the fibrous structures 21 and 23 but also runs along and into the portions of penetrating filament 25 , 26 . During this impregnation, the core 22 is not impregnated with resin because it is impermeable thereto.
The impregnated resin is then cured, for example by raising its temperature, for long enough for the fibrous structures 21 and 23 to become rigid skins 30 and 31 respectively, and for the portions of penetrating filament 25 and 26 to become rigid threadlike spacers 32 . (see FIG. 3 C). These spacers 32 are firmly anchored at their ends in the rigid skins 30 and 31 by rigid anchors 33 and 34 formed, respectively, from the masses 29 and the bridges 27 .
To form the matrix of all the rigid skins 30 and 31 and spacers 32 , said assembly is subjected to pyrolysis at high temperature, for example of the order of 900° C., something which stabilizes the geometry of said assembly and eliminates the core 22 . This assembly may possibly be densified and treated in a known way so that its matrix turns into one of the ceramic type. This then yields the monolithic piece 40 (see FIGS. 2F and 3D ) intended at least in part to form the combustion chamber 1 and comprising:
an outer skin 41 of composite, originating from the skin 31 and intended at least in part to form the outer wall 4 , 4 A, 4 B of the combustion chamber 1 ; an inner skin 42 of composite, originating from the skin 30 and intended to form the inner wall 5 , 5 A, 5 B of the combustion chamber 1 ; and a plurality of threadlike spacers 43 of composite, originating from the spacers 32 .
In this monolithic piece 40 , the skins 41 and 42 are spaced apart, delimiting an annular space 44 crossed by the spacers 43 without being plugged and intended to form the annular space 6 of the combustion chamber 1 .
It is known that, through its nature, a composite is porous and that this porosity depends on the conditions under which the matrix is formed. It can therefore be readily appreciated that the porosity of the inner skin 42 can be tailored to impart thereto the required porosity for the inner wall 5 , 5 A, 5 B. In so doing, the outer skin 41 is given a porosity identical to that desired for the inner skin 42 . Now, since the outer wall 4 needs to be impervious, it may be advantageous for the outer skin 41 to be externally coated with a sealing coating 45 , as is depicted in FIG. 2 F.
A second monolithic composite piece 50 intended to form at least said nozzle 2 is produced. Such a second composite piece 50 is easy to produce by winding or weaving strong fibers (C, Si, etc.) onto an appropriate former, then by impregnating with resin and pyrolyzing the matrix thus formed. Next, to obtain the engine I, the composite monolithic piece 40 is assembled with the composite monolithic piece 50 . This can be done in any known way, for example mechanically or by bonding. In addition, in a preferred embodiment illustrated schematically in FIG. 4 , there is provided on the monolithic composite piece 50 not only a part 51 able to form the throat 3 but also a part 52 able to act as a housing for said composite monolithic piece 40 . In this case, the outer wall 4 of the engine I is then formed by the superposition and assembly of the skin 41 , possibly of the coating 45 , and of the part 52 .
As an alternative, it will be readily appreciated from that which has been described that the second composite piece 50 may be the continuation of the outer skin 41 and form a monolithic piece therewith, as illustrated schematically in FIG. 1 .
In the alternative form of embodiment II of the rocket engine, according to the present invention and depicted in FIG. 5 , the combustion chamber 60 is arranged inside the divergent nozzle 61 , near the vertex 62 thereof. This divergent nozzle 61 consists, for example, of a composite monolithic piece obtained in a similar way to the nozzle 2 as described hereinabove. In addition, provision is made for the vertex 62 of the divergent nozzle 61 to be pierced with an orifice 63 .
The combustion chamber 60 comprises:
an inner composite monolithic piece 64 , of cylindrical shape, arranged coaxially with respect to the axis Z—Z of the engine and having an inner composite skin 65 and an outer composite skin 66 . This composite piece 64 may be obtained in the way described hereinabove with respect to the composite piece 40 ; and an outer composite monolithic piece 67 , of cylindrical shape, arranged coaxially with respect to the axis Z—Z and having an inner composite skin 68 and an outer composite skin 69 . The composite piece 67 may also be obtained in a similar way to the piece 40 .
The outer composite piece 67 surrounds the inner composite piece 64 delimiting between them an annular heart C for said combustion chamber 60 .
The composite pieces 64 and 67 are secured, on the same side as the nozzle 61 , to a manifold 70 able to supply them with gaseous fuel and, on the opposite side, to a third composite monolithic piece 71 , in the form of a horn, connecting them to the divergent nozzle 61 along the edge of the orifice 63 . The combustion chamber 60 forms, between itself and the vertex of the nozzle 61 , an annular passage 72 forming a throat and providing communication with said nozzle.
Just like the wall 41 of the piece 40 , the inner skin 65 of the inner piece 64 is advantageously sealed against gas.
Through the piece 71 , the gaseous oxidizer is introduced into the annular heart C, from the opposite side to the vertex 62 , by injectors 73 . Through the piece 71 and the manifold 70 , the fuel is introduced, from the opposite side to the vertex 62 , into the annular intermediate spaces 74 and 75 (analogous to the intermediate space 44 of the piece 40 ) of the composite pieces 64 and 67 . Through the outer skin 66 of the piece 64 and through the inner skin 68 of the piece 67 , said fuel passes into the annular heart C, where it burns with the oxidizer. The combustion gases escape from the combustion chamber 60 from the same side as the vertex 62 and pass into the nozzle 61 through the throat 72 . The fuel gas escaping through the outer skin 69 cools the nozzle 61 near the combustion chamber 60 . The paths of the gases are indicated by arrows in FIG. 5 .
In the embodiment depicted in FIG. 5 , the fuel supply device comprises a hollow dome 76 supplied with fuel by a duct 77 passing through said piece 71 and itself supplying the manifold 70 . The convex side of the dome 76 faces the same direction as the nozzle 61 , away from the combustion chamber 60 . As a preference, at least the convex wall 78 of said dome 76 is made of thermostructural—and therefore porous—composite, so that this dome is cooled by seepage of said fuel through said convex wall 78 .
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The invention concerns a rocket engine wherein the combustion chamber includes at least one first monolithic component made of a thermostructural composite material comprising a porous wall through which the fuel is introduced in the core of the combustion chamber. A small part of the fuel is directed towards the neck for it to be cooled.
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This invention relates to agricultural implements, and more particularly to the attachment of the implement to the towing tractor so that the weight of the implement is transferred to the tractor to increase the traction thereof.
BACKGROUND OF THE INVENTION
In my earlier Australian patent specification No. 421,141 to which reference can be made, there is described an implement having a V-shaped frame, with land wheels being provided at the ends of the arms of the V, with the apex of the V being attached to and supported by the tractor. In this way the transfer of weight from the carrying implement to the tractor is considerable, and is often at least half the weight of the implement, together with the downward forces produced by the cultivating tool.
This invention is directed to an improved hitch arrangement for such an implement, the hitch in the previous Patent being a conventional hitch to the draw bar of the tractor, where although the transfer of weight to the tractor is achieved, this weight is often transferred to the tractor just rear of the rear axle, and often some considerable distance behind the rear axle. This reaction point on the tractor can give rise to a dangerous situation the tractor tending to rear backwardly.
Various attempts have been made in order to transfer some or all of the weight from a trailed vehicle or implement to the towing tractor.
Thus U.S. Pat. Nos, 1,623,179; 1,799,846; and 2,647,761 discloses a hitch for a trailed vehicle or implement where the connection between the trailed vehicle and the tractor vehicle is at or slightly in front of the rear axle of the tractor vehicle, so that this connection comprises both the draw bar and the weight transfer mechanism.
U.S. Pat Nos. 2,639,159 and 2,312,258 show linkages and mechanisms interconnecting the implement and tractor draw bar in order to achieve some degree of weight transfer, but this transfer of weight is only applied on the conventional draw bar behind the rear wheels of the tractor.
U.S. Pat. Nos. 3,955,831; 3,215,404; 2,899,004 and 2,642,293 each show a hitch arrangement whereby there is a degree of weight transfer from the implement to the tractor, by a linkage separate from the conventional draw bar. Thus there is a lower link and an upper mechanism which transfers or supports some of the weight and/or forces of the trailed implement or machine.
BRIEF DESCRIPTION OF THE INVENTION
Thus it is an object of this invention to provide improved hitch arrangement for the attachment of a trailed implement to a towing tractor in which the hitch arrangement is provided at a more advantageous location on the tractor.
Thus there is provided according to the invention a hitch arrangement for a towed implement, in which the front of the implement is supported by the tractor, the arrangement being such that the implement is provided with a fore carriage which is pivotally supported on the tractor and adjacent the rear axle, the draft being applied to the implement for towing through the conventional draw bar attached to the tractor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view, and
FIG. 2 is a side elevation of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings, the implement 1 can be of the type as shown in Australian Pat. No. 421,141 where the implement has rear wheels and is supported at the front on the tractor to achieve weight transfer.
The fore carriage 2 of the implement is extended, the fore carriage ending in a turn table 3 having a vertical axis, this turn table being attached to the rear of the tractor 5 by a generally horizontal pivot 6 parallel to the rear axle 7 of the tractor. Thus the required pivoting is achieved to allow the tractor to turn corners, and also the horizontal pivot allows relative movement between the tractor and implement about a horizontal axis.
It is to be realised that the actual towing force applied to the implement by the tractor is by a separate draw bar 8 which extends parallel to the extended fore carriage 2, but at a considerable distance therebelow, the draw bar being pivoted by pivot pin 9 to the implement 1.
The fore carriage 2 of the implement 1 carries an extension member 10 and is supported by a pair of spaced rollers 11, 12, these rollers being spaced longitudinally along the fore carriage, and also spaced in a vertical arrangement with the forward roller 11 being at a higher position than the rear roller 12.
This vertical relationship between the rollers 11, 12 is of such a dimension that the extension member 10 is supported thereby, this extension member being attached to the upper member of the turn table 3. Thus it will be seen that due to the spaced rollers 11, 12 engaging at opposite sides of the extension member 10, that the weight will be transferred to the turn table, with the rollers on the extension member allowing the change in the vertical plane between the tractor and the drawn implement by rolling along the extension member.
The rollers 11, 12 are mounted on brackets 13, 14 welded or otherwise attached to the frame 15 of the implement, the rollers 11, 12 being adjustable positioned on each bracket 13, 14 not only to accommodate size for the extension member, but also to provide adjustment for fitting the invention to various tractors whose vertical position for mounting the turn table 3 would vary.
In a preferred form of the embodiment the turn table would be mounted on the tractor in such a position that it would be at least over the rear axle, or slightly forward thereof, and be of such a height, that the extension member 10 would, when the tractor is turning a corner, pass over above the rear wheels of the tractor.
In a preferred form of the invention the extension member can be a circular section member, with the respective rollers being of an arcuate shape to engage the extension member.
Also while the extension member 10 is illustrated as being straight, it can be formed with a goose neck shape to provide clearance over the wheels where the turn table is mounted below the level of the tyres. Also it will be realized that the telescoping of the extension member can be by other means, and the member could slide in a sleeve, and if desired rollers or balls can be provided in the sleeve to minimise the frictional forces encountered due to the large force applied on the extension member due to the weight transfer.
Thus it will be seen that according to the invention there is provided an effective means of mounting an implement on a tractor such that there is effective weight transfer, this being as near as possible to the vertical plane including the rear axle, and either being on this plane or slightly forward thereof in order to prevent the rearing of the tractor.
Even if the turn table can not be mounted directly above or forward of the rear axle, by the invention which allows a limited change from the angular relationship between the tractor and implement in the vertical or longitudinal plane the invention would prevent any excessive angular change such as if the tractor were rearing upwardly, and thus the hitch provides an effective safety measure in this regard.
Also with the advent in the design of tractors, such as four wheel drive tractors which are articulated in the centre of the chassis, and with the development on much wider tyres, thus having a wide profile and a correspondingly reduced diameter, the form of the invention can be readily applied to such tractors which allows the extension of the fore carriage of the implement to pass above the rear wheels of the tractor to allow and provide for an adequate turning radius of the tractor and implement.
Although one form of the invention has been described in some detail it is to be realised tht the invention is not to be limited thereto but can include various modifications falling within the spirit and scope of the invention.
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An implement hitch arrangement comprising a fore carriage extension on the implement connected to a turntable above the rear axle of the tractor whereby the implement is supported at its front end on the tractor. The implement is drawn by a conventional draw bar, so that the weight of the implement is not taken by the draw bar, but by the fore carriage extension.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/965,362 filed Dec. 10, 2010, now assigned U.S. Pat. No. 8,470,051, which claims priority from and benefit of the filing date of U.S. provisional application Ser. No. 61/286,345 filed Dec. 14, 2009, and the entire disclosure of each of said prior applications is hereby expressly incorporated by reference into the present specification.
GOVERNMENT INTEREST
[0002] This invention was made with government support under Contract No. N66001-06-C8005, awarded by Defense Advanced Research Projects Agency. The government has certain rights in the invention.
BACKGROUND
[0003] A “mechanical finger” refers to an elongated, articulating, mechanical appendage. Like a human finger, a mechanical finger has one end joined to a structure that acts as a base and an opposite end that is not anchored or connected. A mechanical finger used for grasping typically has two or more rigid sections, and preferably at least three, connected end to end by articulating joints. Terminology used to describe the anatomy of a human finger is used to describe a mechanical finger. As in the human finger, each section of the finger is referred to as a “phalanx.” A finger extends from a base and is comprised of at least two, and preferably three, phalanges joined end to end by pivoting or articulating joints. A first articulating joint joins a proximal phalanx to a base, such as a palm of a hand. A second articulating joint joins the proximal phalanx to an intermediate or middle phalanx, and a third articulating joint joins the intermediate phalanx to a distal phalanx. The first joint is referred to as the metacarpophalangeal (MCP) joint, the second as the proximal interphalangeal (PIP) joint, and the third as the distal interphalengeal (DIP) joint.
[0004] In a mechanical finger, the phalanges are coupled to one or more motors to cause flexion and extension of the finger. When using a kinematic mechanism for coupling a single motor to the phalanges, the position of the actuator fully determines the position of the joints, but the torque at each joint is unknown. With a differential mechanism, the torque at the actuator determines the torque at each of the driven joints, but neither the velocity nor the position of the individual joints are specified by the actuator velocity or position alone. A kinematic mechanism produces consistent, predictable motion of the finger joints, but it does not allow the finger to curl around an object. Differential mechanisms allow curling and grasping, but often deviate from the desired motion due to forces at the fingertip, causing buckling, or due to friction in the joints, causing undesirable curling behavior when not conforming.
BRIEF DESCRIPTION
[0005] According to one aspect of an exemplary embodiment of a mechanical finger comprising at least two phalanges driven by a single actuator, and a differential transmits torque in parallel from the actuator to the MCP joint and the PIP joint.
[0006] According to another aspect, the mechanical finger further includes a variable stop that limits rotation of the PIP joint based on the angle of rotation of the MCP joint. Such a mechanical finger is capable of exhibiting consistent predictable motion when moving in free space or when contacting an object at the fingertip, and curling in order to conform to an object when the contact is at other locations on the finger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A is a schematic illustration of a mechanical finger driven by a single actuator.
[0008] FIG. 1B is a schematic illustration of an alternate embodiment of a mechanical finger driven by a single actuator.
[0009] FIG. 1C is a schematic illustration of an alternate embodiment of a mechanical finger driven by a single actuator.
[0010] FIG. 1D is a schematic illustration of an alternate embodiment of a mechanical finger driven by a single actuator.
[0011] FIG. 1E is a schematic illustration of an alternate embodiment of a mechanical finger driven by a single actuator.
[0012] FIG. 2 is a perspective view of an example of a prosthetic finger, partially constructed and without a covering, embodying a coupling mechanism according to the principles of the mechanical finger of FIG. 1 .
[0013] FIG. 3 is an exploded view of the prosthetic finger of FIG. 2 .
[0014] FIG. 4A is a side view, rendered with perspective, of proximal and medial phalanges of the prosthetic finger of FIG. 2 , which is only partially constructed to reveal a differential linkage.
[0015] FIG. 4B is a side view, not rendered with perspective, of the partially constructed proximal and medial phalanges of the prosthetic finger of FIG. 2 , in an extended position.
[0016] FIG. 4C is a side view, not rendered with perspective, of the partially constructed proximal and medial phalanges of the prosthetic finger of FIG. 4B , in a fully flexed position.
[0017] FIG. 5A is a side view, rendered with perspective, of proximal and medial phalanges of an alternate embodiment of a prosthetic finger that is partially constructed to reveal a differential linkage.
[0018] FIG. 5B is a side view, not rendered with perspective, of the partially constructed proximal and medial phalanges of an alternate embodiment of the prosthetic finger of FIG. 2 , in an extended position.
[0019] FIG. 5C is a side view, not rendered with perspective, of the partially constructed proximal and medial phalanges of an alternate embodiment of the prosthetic finger of FIG. 5B , in a fully flexed position.
[0020] FIG. 6 is a side view, rendered in perspective of proximal and medial phalanges of alternate embodiment of a mechanical partially constructed to reveal a differential linkage.
[0021] FIG. 7 is a side, perspective view of the partially constructed prosthetic finger of FIG. 2 , with certain elements removed to reveal a linkage.
[0022] FIG. 8A is a side, non-perspective view of the prosthetic finger of FIG. 2 , with several parts removed to illustrate a stop linkage.
[0023] FIG. 8B is a perspective view of FIG. 7B .
DETAILED DESCRIPTION
[0024] In the following description of a mechanical finger, like numbers refer to like parts.
[0025] FIGS. 1A-1E schematically illustrate several alternative embodiments of mechanisms for driving a mechanical finger 100 using a single motor. The mechanism combines a differential, a kinematic linkage and a PIP linkage for coupling the torque and position of a drive output to a mechanical finger 100 having at least two sections in order to control its flexion and extension in a manner that permits it to be used in connection with grasping or other applications in which a curling action is desirable. Such applications include, but are not limited to, robotic hands and prosthetic hands.
[0026] The illustrated examples of mechanical finger 100 comprise at least a proximal phalanx 102 , a medial or middle phalanx 104 , and, in the embodiments of FIGS. 1A to 1E , a distal phalanx 106 . “Phalanx” refers to an elongated, rigid section of the finger, and “phalanges” to multiple sections of the finger. The phalanges are sometimes also referred to herein as first, second and third sections, respectively, of the mechanical finger. Articulating joints, which are not expressly indicated in the figure, permit joined phalanges to pivot with respect to each other around an axis of the joint. The X-axis 108 of the figure represents the angle of extension and flexion of the phalanges relative to each other and to a reference ground 110 . A greater angle indicates flexion of the finger and a smaller angle indicates extension of the finger. The length of arrow 112 represents the angle, designated by the variable Θ PF between the proximal phalanx 102 and a ground 110 . Similarly, the lengths of arrows 114 and 116 represent the relative angles between the proximal phalanx and the middle phalanx, and between the middle phalanx and the distal phalanx, respectively. These angles are designated in the figure by the variables Θ MF and Θ DF , respectively.
[0027] The angular position and torque transmitted by an output of a single actuator or drive, which output is represented by line 118 , controls the flexion and extension of the finger. Any type of suitable motor can power the actuator or drive. The type of the motor will depend on the application. The angular position of the output is represented by line 120 and is designated by the variable Θ m . Torque applied to an object by a joint is represented as a linear force in the figure. The torque delivered by the output of the drive is represented by line 122 . Variable T m represents the magnitude of the torque from a motor connected to the drive. Note that the motor is not expressly illustrated in the figures. Torque on the metacarpophalangeal (MCP) joint (not shown), designated T mcp , which is generated by force applied to the proximal phalanx, is represented by line 103 . Similarly, torque on the proximal interphalangeal (PIP) joint (not shown) is designated T pip and is represented by line 105 . Torque on the distal interphalangeal (DIP) joint (not shown) is designated T pip and is represented by line 105 .
[0028] A hybrid mechanism comprising a kinematic linkage and differential enables conformal grasping by the finger due to the differential, but at the same time curling behavior can be precisely defined during application of forces to the distal phalanx only. In the examples illustrated by the schematics of FIGS. 1A-1E , a differential 124 coupled to ground 110 applies the torque T m from the motor to the proximal phalanx 102 . The differential also applies the torque to linkage 130 in the embodiments of FIGS. 1A , 1 B, 1 D, or to medial phalanx 104 in the two-phalanx embodiment of FIG. 1C , or to a second differential 125 in the embodiment of FIG. 1E . The differential 124 couples the drive output with the MCP joint and the PIP joint. Thus, the drive applies torque to both the PIP and MCP joints in the embodiments of FIGS. 1A-1C and 1 E. In the embodiment of FIG. 1D , the combination of differential 124 and differential 125 applies torque applied to the MCP, PIP and DIP joints.
[0029] Linkage 130 in FIGS. 1A , 1 B, and 1 E functions as a kinematic linkage, coupling the motion of PIP and DIP joints through an algebraic relationship. Linkage 130 couples the PIP and DIP joints (not shown), so that both joints rotate together, in a fixed relationship, resulting in the medial and distal phalanges curling together in a natural curling motion. Movement of link 130 relative to the proximal phalanx 102 causes the middle phalanx to rotate about the PIP joint (not shown), and the distal phalanx to rotate with respect to the middle phalanx around the DIP joint (not shown). This coupled curling relative to the proximal phalanx 102 occurs even while motion of proximal phalanx 102 is blocked, such as when conformal grasping is occurring.
[0030] As shown in the embodiment illustrated only in FIG. 1B , the linkage 124 may, optionally, include a compliant element 128 , in series with ground, represented in the figure by spring 128 . The compliant element is, for example, comprised of an elastic element that generates a spring force. The spring provides compliance for series elasticity and shock mitigation by allowing linkage 124 to stretch a little when forces are applied to it. Elasticity and shock mitigation or dampening can be desirable in certain applications, such a prosthetics. Movement of the linkage 130 relative to the proximal phalanx 102 , such as during curling when the proximal phalanx 102 is blocked, also results in compression of a compliant member represented in the figure by a spring 132 coupled between the proximal phalanx and the link 130 . The spring acts to extend the PIP joint.
[0031] Referring only to FIGS. 1A-1D , in each of the illustrated examples a linkage 126 adjusts the position of stop 134 based on rotation of the MCP joint. Stop 134 limits the range of motion of the PIP joint. The linkage sets the position of the hard stop based on the degree of rotation of the MCP joint from ground. Stopping rotation of the PIP joint limits extension of the medial phalanx, as well as the distal phalanx, beyond a predetermined angle relative to the proximal phalanx. The angle of rotation of the MCP joint is represented in the figure as the distance between ground 110 and the proximal phalanx 102 . The angle of the PIP joint relative to the phalanx is indicated by the length of line 114 in the figure. The stop rotates with respect to the PIP joint as the MCP joint rotates, and thus it depends on the angle of the MCP joint. When the proximal phalanges motion is not blocked, the stop linkage 126 enforces natural, simultaneous curling of all three joints, the MCP, PIP and DIP joints. Linkage 126 also enables the finger to resist forces on the distal phalanx without the differential allowing the PIP and DIP joints to straighten and the MCP joint to flex. Despite the system having a differential, the posture of all three joints can thus remain fixed (not against stops) irrespective of the magnitude of a single external force applied to the distal phalanx.
[0032] Because of the use of a differential linkage to couple torque from the drive to the MCP and PIP joints, the positions of the MCP and PIP joints are not fully determined by the position of the drive. For any given position of the drive output, the finger mechanism has one free motion available, which is an extension of the proximal phalanx and a flexing of the PIP and DIP joints. Preferably, linkage dimensions and moment arms are chosen so that external forces applied to the finger distal to a point near the fingertip act to straighten the finger, and forces applied proximal to this point act to curl the finger. The point at which the behavior changes from straightening to curling is referenced as the “focal point” of the differential. For external forces that act proximal to the focal point, the MCP joint will extend and the PIP joint will flex.
[0033] Referring now to FIGS. 1A-1E , the linkage 126 is also used to move the endpoint for return spring 132 . The return spring 132 acts to straighten the finger and to keep the mechanism pushed over to one side of this free range of motion. In the absence of any external forces pushing on the finger, the return spring makes the finger act as though the differential 124 is not present. The return spring can also provide some resistance to curling of the fingers when forces are applied to the dorsal side of the finger. Any compliance in the differential 124 will result in some motion, but this will occur in all three joints and is not due to the differential coupling.
[0034] As illustrated by the embodiment of FIG. 1E , adjustable stop 134 for the PIP joint may be omitted for an application not requiring it, or in which it is desirable not to have it. In this example, the linkage 126 controls only the position of the end point of the PIP joint return spring 132 . The linkage 126 thus becomes a spring centering linkage.
[0035] Referring now only to FIG. 1D , this embodiment of a mechanical finger includes a differential 125 comprising differential linkage 136 in place of a kinematic linkage. The differential couples the medial and distal phalanges using a differential relationship. This embodiment also optionally includes an adjustable stop 138 for the DIP joint and return spring 140 for placing a torque on the DIP joint that tends to extend the distal phalanx relative to the medial phalanx. Linkage 142 is connected to proximal phalanx 102 and adjusts the position of DIP stop 138 based on the angle of rotation of the PIP joint. It also sets the endpoint of return spring 140 .
[0036] FIGS. 2 , 3 , 4 A- 4 C, 5 A- 5 C, 6 , 7 and 8 A-B illustrate various aspects of an exemplary embodiments of mechanical finger 100 for use in a prosthetic application. The prosthesis comprises at least one prosthetic finger 200 . The prosthesis may also include, depending on the needs of the patient, a prosthetic hand, comprising a prosthetic palm to which the mechanical finger is attached, and a prosthetic arm, to which the prosthetic hand is attached. Only the internal structure of the prosthetic finger is illustrated in the figures.
[0037] Prosthetic finger 200 is comprised of proximal phalanx 202 , medial phalanx 204 , and distal phalanx 206 . Distal phalanx 206 has been omitted from FIGS. 4A-4F for purposes of illustration. Metacarpophalangeal (MCP) joint 208 connects the finger to a base element, for example, an artificial palm or hand, which is not shown. Proximal interphalangeal (PIP) joint 210 joins the proximal and medial phalanges. Distal interphalangeal (DIP) joint 212 joins the medial and distal phalanges.
[0038] In the embodiment shown in FIGS. 3 and 4 A- 4 C, the proximal phalanx 202 houses a differential linkage comprised of a connecting rod 214 , a pivot link 216 , and another connecting rod 218 . Connecting rod 214 is joined by pin 220 to an arm extending from drive output 222 , and thus connects the output drive to one end of the pivot link 216 . Although not shown, a motor—a stepper motor, for example—located in the base element rotates a drive input, which in this example is pin 223 , which in turn rotates the drive output. Drive output 222 is fixed to the pin 223 . Pin 221 joins the connecting rod to the spring. Connecting rod 218 connects the other end of the pivot link to plate 228 of the medial phalanx 204 . Pin 224 joins the pivot link to the connecting rod 218 , and pin 226 joins the connecting rod to the plates 228 a and 228 b, which comprise the primary structural elements for medial phalanx 204 . The midpoint of the pivot link is fixed by pin 230 to plates 232 a and 232 b. The pivot link will rotate within the proximal phalanx, about the axis of pin 230 , as indicated by comparing FIGS. 4B and 4C , when the drive output rotates. During flexion, rotation of the drive output 222 pulls the connecting rod 214 , which pulls on the pivot link 216 , which pulls on a second connecting rod 218 , which pulls on plates 228 a and 228 b of the medial phalanx.
[0039] In an alternate embodiment shown in FIGS. 5A-5C , the pivot link 216 ( FIGS. 4A-4C ) is replaced by an in series compliant element for giving the finger compliance for series elasticity and shock mitigation. In this example, the compliant element comprises spring 217 . Except for the added compliance and elasticity provided by the spring, the differential with spring performs in a substantially similar manner as the pivot link 216 . In another alternate embodiment shown in FIG. 6 , the pivot link 216 and the connecting rods 214 and 218 are replaced with a linkage comprising a single connecting rod 219 that is connected by pins 220 and 226 to the drive housing 220 and plate 228 b of the medial phalanx 204 . As can be seen in the figure, the connecting rod must extend beyond the envelope of the proximal phalanx 204 .
[0040] In each of the embodiments shown in FIGS. 2 to 8B , plates 228 a and 228 b are the primary structural elements of medial phalanx 204 . Plates 232 a and 232 b are the primary structural elements comprising the proximal phalanx 202 . The differential linkage of FIGS. 4A-4C and 5 A- 5 C described above is housed between the plates. To these plates can be attached shells to give the proximal phalanx its desired exterior shape in the particular prosthetic or other application.
[0041] The pins used to join components in the differential linkage, as well as in other linkages described below, permit relative rotation of the joints that are joined. The location of pin 226 is eccentric to the axis of the PIP joint to form a moment arm. The axis of the PIP joint is defined by pin 236 , which pivotally connects the clevis formed by plates 232 a and 232 b of the proximal phalanx with plates 228 a and 228 b of the medial phalanx. For a given rotation of the drive output, either the MCP joint or the PIP joint can rotate. Rotation of the drive output not only applies torque to the MCP joint by causing the pivot link to push against pin 230 , but it also rotates the link, causing the other part of the link to transmit a force that is applied to pin 226 . Even if the proximal phalanx is blocked, the link will nevertheless pivot and apply torque to the PIP joint. Thus, torque from the drive is applied to both the MCP joint and the PIP joint.
[0042] Referring now to FIGS. 2 , 3 , and 7 , the medial phalange 204 houses a kinematic linkage for coupling rotation of the PIP joint to the DIP joint so that both curl simultaneously. The kinematic linkage comprises a connecting rod 238 that spans between the proximal phalanx 202 and the distal phalanx 206 . Pin 240 at a proximal end of the connecting rod engages hole 242 on plate 232 b of the proximal phalanx. Pin 244 on the distal end of the connecting rod engages hole 246 in the distal phalanx. The distal phalanx is linked to the medial phalanx by a hinge formed by pins 248 a and 248 b. These pins cooperate respectively, with a hole 250 a on plate 228 a and hole 250 b on plate 228 b of the medial phalanx, and with holes 250 a and 250 b on opposite forks of a clevis extending from a shell forming distal phalanx 252 . Although in this embodiment the linkage is comprised of a single connecting rod, it could comprise multiple links. Furthermore, a differential could be substituted for the kinematic linkage, as described in connection with FIG. 1D .
[0043] Referring now only to FIGS. 2 , 3 , 8 A and 8 B, the mechanical finger 200 includes, in this embodiment, fixed stop 253 that stops rotation of the PIP joint to prevent hyperextension of the medial phalanx. In this embodiment, a movable PIP stop part 254 rotates on the same axis as the PIP joint to reduce the permitted range of motion of the medial phalanx by limiting further rotation of the PIP joint based on the degree of flexion of the MCP joint. The centerline of pin 236 defines the axis of rotation. The PIP stop part stop includes a stop portion 255 that interferes with 257 of plate 228 a of the medial phalanx to prevent the medial phalanx from extending. The position of the PIP stop part 254 is based on the degree of rotation of the MCP joint, and is accomplished in this embodiment by a linkage comprising connecting rod 260 between a housing 256 for a drive (not shown) and PIP stop part 254 . The linkage may also be implemented using multiple links. A pin connects the distal end of connecting rod 260 to arm portion 264 of the PIP stop part 254 . The proximal end of connecting rod 258 is connected by another pin to the drive housing. As the MCP joint rotates due to flexion of the proximal phalanx 202 , the connecting rod pulls on the arm 264 , causing the PIP stop part to rotate in the same direction.
[0044] With the PIP-stop linkage, the medial phalanx 204 is stopped either by the fixed stop 253 on the proximal phalanx when the proximal phalanx is fully extended, or by the movable stop of PIP-stop part 254 when the MCP joint is rotated during flexion of the proximal phalanx. If the MCP joint rotates, then the PIP joint is forced to rotate as well by the PIP-stop part. During free motion, or when forces are applied to the fingertip, movement of the PIP-stop part helps to produce predictable curling like a fully kinematic mechanism.
[0045] In this embodiment, the rotational position of the PIP-stop part 254 also controls the endpoint 270 of the return spring 266 . This spring, which is normally compressed, has the effect of extending the medial phalanx, thus pushing the PIP joint against the PIP-stop. If no external forces act on the finger, the force generated by the spring causes the motion of the finger joints to be controlled by the PIP-stop. If, however, an object blocks the motion of the proximal phalanx, then the differential linkage continues applying torque to the PIP joint, causing PIP and DIP joints to curl and further compressing the return spring.
[0046] The kinematic linkage for controlling the position of the PIP stop based on the motion of the MCP joint could also be used to limit or affect the motion of the PIP and DIP joints in other ways. For example, the PIP stop can be removed, permitting the linkage to be for controlling the end point of the return spring without limiting the motion of the PIP joint.
[0047] Although not necessary for operation of the finger as described above, joint positions can be measured using potentiometers coupled with the joints and feedback to a controller for the drive motor in order to drive the finger to desired position, subject to the limitations of being able to do so caused by the differential. Similarly, strain gauges can be placed on, for example, the drive housing 256 to measure torque on the finger and feed the measured torque back to a controller to change the impedance of the finger.
[0048] Although the particular components forming the linkages and the phalanges illustrated in FIGS. 2-7 have advantages when used in a prosthetic application, the structures are intended to be illustrative only of the linkage mechanisms illustrated by FIG. 1 . These components can be adapted or substituted for when implementing a differential mechanism in parallel with a kinematic mechanism in accordance with FIG. 1 . For example, linkages may be replaced with belts or cables or other passive mechanical mechanisms to achieve the same general purpose. Although it is common to use linkages for kinematic mechanisms and cables for differential mechanisms, but either type can be used for either purpose. In addition to being implemented as a linkage, as exemplified by FIGS. 2-8B , the differentials described above may also be implemented using a belt or cable, for example one linking the drive output to a drum or pulley at the PIP joint, a gear train, or a toggle.
[0049] Furthermore, applications in which a mechanical finger in accordance with FIGS. 1A-1E can be used include any type of application involving grasping, and include many different types of robotic applications that are not limited to those attempting to mimic a human hand or prosthetic applications. For instance, an anthropomorphic grip may have benefits in many diverse or unstructured or unforeseen contexts just as human hands are so successfully versatile, including industrial grippers, rovers or mobile robots, entertainment, home robots, surgery or minimally invasive surgery, massage, patient transfer or stabilization, and many others.
[0050] The foregoing description is of exemplary and preferred embodiments. The invention, as defined by the appended claims, is not limited to the described embodiments. Alterations and modifications to the disclosed embodiments may be made without departing from the invention. The meaning of the terms used in the claims are, unless expressly stated otherwise, intended to have ordinary and customary meaning and are not intended to be limited to the details of the illustrated structures or the disclosed embodiments.
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A mechanical finger comprises a plurality of phalanges coupled to a single actuator using a kinematic linkage and a differential linkage arranged in parallel. The mechanical finger is capable of exhibiting consistent predictable motion when moving in free space or when contacting an object at the fingertip, and of curling in order to conform to an object when the contact is at other locations on the finger.
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FIELD OF THE INVENTION
The present invention pertains to a ball pivot of a ball-and-socket joint for motor vehicles with a joint ball and with a pivot connected to the joint ball. The present invention also pertains to a wheel suspension of a motor vehicle for the spring-loaded connection of at least one wheel to the frame or the chassis of the motor vehicle with at least one shock-absorbing strut and at least one suspension.
BACKGROUND OF THE INVENTION
Such a ball pivot of a ball-and-socket joint for motor vehicles has been known from, e.g., the Patent DE 44 03 584 C2. With the design features according to the preamble, these ball pivots are frequently used in highly stressed ball-and-socket joints in chassis of motor vehicles and have been manufactured in large numbers by the corresponding manufacturers for decades. The ball pivot comprises a joint ball and an essentially cylindrical pivot pin connected thereto. The pivot pin is provided with threads over at least a substantial part of its length, so that the ball pivot can be introduced with the pivot into an opening of a component of the motor vehicle intended for this purpose in order to be fastened to the pivot pin by means of a nut screwed onto the pivot pin. A support surface, with which the pivot pin is supported against the pressing force of the nut screwed onto the thread, is usually provided on the side of the joint ball.
If the above-described nut is to be tightened or loosened during the mounting or removal of the ball pivot, it is necessary to fix the ball pivot itself with the pivot connected thereto in order to prevent the pivot from rotating together with the nut. This is achieved in the prior-art embodiments mostly by providing a multitooth engagement (Torx), a hexagon socket, a hexagon insert, or the like, at the pivot pin on the inside or on the outside, by means of which an opposite torque can be achieved between the nut to be tightened or loosened and the pivot itself. However, it was found in practical use that the multitooth engagement is very often destroyed by, e.g., stones and weather effects, so that major problems occur at the time of the removal of the ball-and-socket joint. Since it is impossible to fix the ball pivot because of the destruction of the multitooth engagement and the thread at the pivot pin is also heavily contaminated and stiff due to the use of the vehicle, the entire cylindrical pivot rotates together with the nut after the loosening moment of the cylindrical pivot has been exceeded. Thus, loosening of the cylindrical pivot pin is hardly possible or is possible only with great difficulty.
SUMMARY AND OBJECTS OF THE INVENTION
The primary object of the present invention is to improve the prior-art ball pivot with a joint ball and with a pivot pin connected to the joint ball such that the ball pivot will be prevented from rotating during loosening or tightening of the ball pivot in a component of the motor vehicle.
According to the invention, a ball pivot of a ball-and-socket joint for motor vehicles is provided. The ball pivot has a joint ball and a pivot pin connected to the joint ball. A substantial part of the pivot pin is made nonround for preventing the ball pivot from rotating.
Thus, the invention provides that a ball pivot of a ball-and-joint socket for motor vehicles with a joint ball and with a pivot connected to the joint ball be further improved such that at least a substantial part of the pivot pin is made nonround. It is achieved due to this nonround design of a substantial part of the pivot pin that the pivot pin can be supported with respect to rotation in the motor vehicle component to which it is to be connected or is connected. To achieve this, the nonround part of the pivot pin must be located at least partially in the area of the opening of the motor vehicle component, through which the pivot pin of the ball pivot is inserted. This opening of the motor vehicle component may be, e.g., an elongated hole in the motor vehicle component or an opening designed corresponding to the nonround shape of the pivot pin. A multitooth engagement at the ball pivot or another possible securing against rotation of the ball pivot can be advantageously abandoned due to the nonround design of the part of the pivot pin extending into the opening of the motor vehicle component.
An advantageous variant of the nonround shape of the substantial part of the pivot pin may be the oval or angular design of the pivot, e.g., in the form of a square or polygon.
According to another advantageous variant of the ball pivot according to the present invention, the ball pivot may have a separate support surface between the ball pivot and the pivot pin, which support surface may be supported, e.g., against an opposite surface of the motor vehicle component, to which the ball pivot is to be connected, during tightening by means of a nut. Furthermore, it may be advantageous in this connection for the support surface to extend flatly and at right angles to the central axis of the pivot pin.
According to another advantageous embodiment of the ball pivot according to the present invention, at least part of the length of the pivot pin is provided with a connection contour. This may be, e.g., a thread, a force fit, a bayonet or another, similar, prior-art connection contour.
It is advantageous in the design of the contour for the cross-sectional area of the part of the pivot pin that has the connection contour—viewed in the cross section through the central axis of the pivot pin—to be located within the contour of the cross-sectional area of the nonround part of the pivot pin. In other words, in a cross section at right angles to the central axis of the pivot pin, the cross-sectional areas of the part of the pivot pin that carries the connection contour shall be advantageously located completely within the cross-sectional area of the nonround pant. It is thus guaranteed that the threaded part of the pivot pin can also be passed through all openings through which the nonround part of the pivot pin fits. Coaxial position of the two cross-sectional areas and viewing the cross-sectional areas in the direction of the central axis of the pivot pin of the ball pivot is assumed in this approach.
According to another advantageous embodiment of the ball pivot, the pivot pin has a notch or groove on the side located opposite the joint ball. As a result, it is advantageously possible to achieve a correct alignment of the ball pivot during the mounting of the ball pivot in the motor vehicle component or to facilitate such alignment.
According to another aspect of the object of the invention, it is suggested that the prior-art wheel suspension of a motor vehicle for the spring-loaded connection of at least one wheel to the frame or to the chassis of the motor vehicle with at least one shock-absorbing strut and at least one suspension arm be improved such that a ball-and-socket joint is provided as a nonpositive connection between at least one shock-absorbing strut and at least one suspension arm. This ball-and-socket joint may advantageously have a means for securing against rotation, as it is described in the preceding text or also in the following exemplary embodiments or in the claims.
It is apparent that the above-mentioned features of the present invention, which will be explained below, may be used not only in the combination described, but also in other combinations or alone, without going beyond the scope of the present invention.
Other features and advantages of the present invention appear from the following description of a preferred exemplary embodiment with reference to the drawings.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a view of a ball pivot in the direction of arrow I according to the representation in FIG. 3;
FIG. 2 is a view of a ball pivot in the direction of arrow II according to the representation in FIG. 3;
FIG. 3 is a cross sectional view taken along line III—III through a ball pivot according to the representation in FIG. 2;
FIG. 4 is a cross sectional view through the motor vehicle component with ball pivot;
FIG. 5 is a top view of a wheel suspension;
FIG. 6 is a front view of the wheel suspension according to FIG. 5;
FIG. 7 is a view of the lower suspension arm;
FIG. 8 is a detail view of the suspension arm with ball pivots; and
FIG. 9 is a cross sectional view of the ball pivot at the suspension arm.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in particular, FIGS. 1 through 3 show views I and II as well as section III—III through an exemplary embodiment of the ball pivot according to the present invention. In FIG. 1, view I shows the ball pivot 1 with the joint ball 2 , arranged on top, which has a flattened area on its top side. On the underside of the joint ball 2 joins an piece 6 with a contraction 6 . 1 . The intermediate piece 6 passes over into the pivot 3 proper. The contraction 6 . 1 of the intermediate piece 6 contributes to an increase in the radius of movement of the ball pivot. A support surface 4 , which extends at right angles to the central axis 5 of the pivot, is located under the intermediate piece 6 . The pivot 3 has two partial sections, namely, a first partial section 3 . 1 with a contour that is nonround according to the present invention (a nonround outer surface contour), and a second partial section threaded part 3 . 2 , which has a connection contour, here external threads. The nonround partial section 3 . 1 of the pivot 3 is arranged between the support surface 4 and the threaded part 3 . 2 of the pivot.
FIG. 2 shows view II according to the representation in FIG. 3 .
The contour of the cross-sectional area 3 . 1 . 1 of the nonround part 3 . 1 of the pivot pin 3 can be recognized especially well in FIG. 3, which shows the section III—III at right angles to the central axis 5 of the pivot pin 3 . The contour has an approximately oval shape with a short distance “d” and a great distance “D.” The round contour of the cross-sectional area 3 . 2 . 1 . of the threaded part 3 . 2 of the pivot pin 3 is located in this view within the contour of the cross-section area 3 . 1 . 1 , so that the pivot pin 3 can be introduced unhindered into a correspondingly shaped opening, e.g., that of a motor vehicle component, until it comes into contact with the support surface 4 .
The groove 3 . 2 . 2 at the end of the pivot pin 3 , which can be used as an orienting means for aligning the ball pivot during the mounting of the ball pivot, is additionally shown in FIGS. 2 and 3.
The width of the groove 3 . 2 . 2 is designated by “L.” The following equation may be used to determine the approximate value of the dimensions of a ball pivot according to the present invention: D=2R+L, in which “R” is the radius of the semicircle of the approximately oval cross-sectional area 3 . 1 . 1 . The radius of the semicircle on one side of the groove may, of course, differ from the radius on the other side of the groove. Consequently, it is not absolutely necessary to have the same value of “R” to embody the object of the present invention, so that asymmetric cross-section geometries of the cross-sectional area 3 . 1 . 1 are conceivable.
FIG. 4 shows a mounted situation of a ball pivot in a motor vehicle component 8 . The motor vehicle component 8 drawn by shading has an elongated opening 7 , which is engaged by the nonround part (nonround portion) 3 . 1 of the pivot 3 . If the ball pivot 1 is fastened with a nut to the threaded part (connection portion) 3 . 2 of the pivot 3 at the motor vehicle component 8 , the nonround contour (nonround outer surface contour) of the part 3 . 1 prevents the pivot from rotating in relation to the motor vehicle component 8 during the tightening or loosening of the nut. Thus, it is no longer necessary to equip the ball pivot 1 with a multitooth engagement or another means for preventing rotation at its end, and it is also possible to remove the pivot without difficulties after a prolonged time of use.
FIGS. 5 through 9 show a variant of the object of the present invention, namely, a wheel suspension of a motor vehicle, in which a ball-and-socket joint is provided as a nonpositive connection between the shock-absorbing strut and the suspension arm.
FIGS. 5 and 6 show a top view and a front view, respectively, of an axle shown as an example with a wheel suspension from the top, with a partial view of the vehicle frame (chassis/or chassis connection) 11 of the motor vehicle. In the known manner, this wheel suspension comprises, per wheel 50 and wheel connection 52 to be suspended, wheel suspension components including an upper suspension arm 14 , a lower suspension arm 15 and a tie rod 16 , and a shock-absorbing strut (spring loaded connection) 12 connected to the lower suspension arm. The two suspension arms on the right and left are connected via a sway bar 13 . The connection between the shock-absorbing strut (shock-absorbing strut motor vehicle component) 12 and the lower suspension arm (a suspension arm motor vehicle component) 15 is brought about according to the present invention by means of a ball-and-socket joint 17 , in which an above-described ball pivot is preferably used in at least one ball-and-socket joint.
FIG. 7 shows a detail view of a suspension arm 15 of the wheel suspension 10 with the ball-and-socket joint 17 .
FIG. 8 shows a section through the ball-and-socket joint 17 mounted in the suspension arm 15 . The suspension arm 15 has an opening 7 , into which the ball pivot 1 with the pivot 3 is inserted. With its support surface 4 , the ball pivot 1 lies on the top side of the suspension arm. It is advantageous for the opening 7 to have different longitudinal and width extensions and for the pivot 3 of the ball-and-socket joint to be designed complementarily at least partially in this area of the opening 7 . It is achieved as a result that the pivot can be supported with a partial surface of the nonround section of the pivot against a part of the wall of the opening for securing against rotation (i.e. a nonround inner surface). The nonround part 3 . 1 of the pivot 3 passes through the likewise nonround opening (a motor vehicle component opening) 7 of the suspension arm 15 , and the threaded part 3 . 2 of the pivot 3 projects from the suspension arm 15 on the underside. A nut 9 , which firmly connects the ball pivot 1 to the suspension arm 15 , is screwed on the threaded part 3 . 2 of the pivot 3 . Due to the above-described design of both the opening 7 in the motor vehicle component and of the pivot 3 of the ball pivot 1 , the ball pivot 1 is prevented from rotating during the loosening of the nut 9 , as a result of which reliable and problem-free loosening of the ball pivot 1 from the suspension arm 15 is possible without any other special measures for fixing the ball pivot 1 . This is also particularly advantageous when the upper part of the ball pivot is covered by other components such that it cannot be prevented from rotating by means of tools.
The cross section through the ball pivot for fastening the shock-absorbing strut at the lower suspension arm 15 is again shown in detail in FIG. 9 . The joint ball 2 with the intermediate piece 6 , with the nonround part of the pivot 3 : 1 and with the threaded part 3 . 2 of the pivot can be seen as a shaded part. The threaded part 3 . 2 carries the nut 9 , which presses the ball pivot with the support surface 4 against an opposite surface of the lower suspension arm and thus fastens it to the suspension arm 15 . The nonround part of the pivot 3 . 1 may be designed as an oval according to the present invention, so that the ball pivot is prevented from rotating in relation to the suspension arm. It is, of course, also possible to design the nonround part 3 . 1 of the pivot pin 3 in the form of a square, so that rotation of the pivot within a likewise nonround opening can be prevented.
The embodiment of a wheel suspension, in which the connection between the shock-absorbing strut and the suspension arm is brought about by means of a ball pivot, is particularly advantageous even without a nonround partial section of the ball pivot, because an especially high degree of mobility of the shock-absorbing strut is achieved due to the ball pivot, and no tensions can be transmitted from the moving suspension arm into the shock-absorbing) arm as a result. However, the embodiment of the ball pivot with the above-described means for preventing rotation decisively improves the behavior of the wheel suspension, especially of the suspension arm and the shock-absorbing strut, during mounting and removal.
It is now possible with the embodiments shown, compared with the state of the art, to abandon a multitooth engagement (Torx) in the ball pivots, while the ball pivot is securely prevented at the same time from rotating during mounting and removal. Due to the use of a ball pivot as a fastening element for the shock-absorbing strut in a wheel suspension, it is, on the other hand, advantageously ensured, compared with the state of the art, that tensioning of the shock-absorption strut is avoided, because it is now fastened extensively freely movably to the suspension arm and better function of the shock-absorbing strut and the wheel suspension is thus achieved.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
APPENDIX
List of Reference Numbers
1
The ball pivot
2
Joint ball
3
Pivot
3.1
Nonround part of pivot
3.1.1
Contour of the nonround part of the pivot
3.2
Threaded part of pivot
3.2.1
Contour of the threaded part of the pivot
3.2.2
Groove
4
Support surface
5
Centrat axis of pivot
6
Intermediate piece
6.1
Contraction
7
Opening in motor vehicle component
8
Motor vehicle component
9
Nut
10
Wheel suspension
11
Frame
12
Shock-absorbing strut
13
Sway bar
14
Upper suspension arm
15
Lower suspension arm
16
Tie rod
17
Ball-and-socket joint
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A ball pivot ( 1 ) of a ball-and-socket joint for motor vehicles with a joint ball ( 2 ) and with a pivot ( 3 ) connected to the joint ball ( 2 ) is presented, in which a substantial part ( 3.1 ) of the pivot ( 3 ) is made nonround for preventing the ball pivot from rotating. A wheel suspension is also disclosed in which a nonround ball pivot is used.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit and priority of Great Britain Patent Application No. 1207996.8, filed May 4, 2012. The entire disclosure of the above application is incorporated herein by reference.
FIELD
[0002] The present invention relates to a sealing element, in particular, but not exclusively, a sealing element for sealing between planar surfaces.
BACKGROUND
[0003] The use of rubber seals or gaskets is known. The present invention aims to alleviate, at least to a certain extent, the problems and/or address at least to a certain extent the difficulties associated with the prior art.
SUMMARY
[0004] According to the present invention, there is provided a sealing element comprising, in cross-section, a body and a first sealing part, the first sealing part providing a sealing face, the first sealing part being connected to and angularly and resiliently displaceable relative to a first surface of the body.
[0005] In this way, when in use, the first sealing part provides a seal against a component against which it is placed. Because the first sealing part is resiliently and angularly displaceable, the sealing element may still seek to provide a consistent seal even if the surface of a component against which the sealing element is placed is not perfectly smooth.
[0006] Preferably, in cross-section, the sealing element further comprises a second sealing part providing a sealing face, the second sealing part being spaced from the first sealing part and extending substantially perpendicular from the first side of the body. In this way, the second sealing part can provide a first seal, against, for example water and dust, and the first sealing element, can provide a second seal. The provision of two sealing parts provides a double line of defence.
[0007] Preferably, in cross-section, the first sealing part, in an unbiased state, forms an angle of less than 90 degrees with the first surface of the body. By providing an angled first sealing part, when in use, a larger area of sealing contact can be provided.
[0008] Preferably, in cross-section, the first sealing part, in an unbiased state, is angled toward the second sealing part. In use, where the second sealing part provides an outer sealing part, the first sealing part provides an inner sealing part. Preferably, a pocket or cavity is provided between the first sealing part and the first surface of the body. In use, if, for example, a fluid such as water should pass the second sealing part, the fluid may provide pressure between the first sealing part and the body. This pressure may in turn cause the first sealing part and its outer sealing surface to have an increased sealing force against a component against which the sealing element is positioned.
[0009] Preferably, in cross-section, the first sealing part tapers from a first end thereof, where connected to the body, towards a second, free end of the first sealing part. Preferably, the first sealing part is fin shaped. Towards the free end of the first sealing part, the first sealing part may be increasingly flexible. Preferably, in its unbiased state, the sides of the first sealing part are substantially planar.
[0010] Preferably, in cross-section, the second sealing part is formed with a radiused, rounded or generally semi-circular profile. Preferably, the second sealing part is formed as a rounded bead. The surface of the radiused, rounded or semi-circular profile may provide a sealing surface.
[0011] Preferably, the sealing element comprises, in cross-section, a third sealing part, the third sealing part being formed similarly to the first sealing part, the third sealing part being connected to and inclined at an angle to a second side of the body opposing the first side of the body. In this way, a similar sealing arrangement may be made against components positioned on either side of the sealing element.
[0012] Preferably, in cross-section, the first sealing part is substantially in alignment with the third sealing part. An even sealing force may therefore be provided at various points along the sealing element.
[0013] Preferably, the sealing element comprises, in cross-section, a fourth sealing part, the fourth sealing part being formed similarly to the second sealing part and extending substantially perpendicular to the first sealing part on the second side of the body opposing the first side of the body.
[0014] Preferably, the second sealing part is substantially in alignment with the fourth sealing part.
[0015] Preferably, in cross-section, the body is formed at its first end with a stepped profile. Preferably, in cross-section, the body is formed at its second end with a stepped profile.
[0016] Such a profile assists the release of the sealing element from a mould during manufacture. Instead of a stepped profile, any irregular profile may be provided.
[0017] Preferably, in cross-section, the first and second sides of the body are substantially parallel.
[0018] Preferably, in cross-section, the body is formed with a reduced diameter width between the second sealing element and the second end of the body.
[0019] Preferably, in cross-section, the sealing element is substantially symmetric along its centreline. The sealing element may be symmetrical along its centreline apart from the stepped ends.
[0020] Preferably, the sealing element forms a continuous closed loop. The sealing element may be formed to provide a seal around an aperture in an assembly. The sealing parts may be provided around the entire circumference of the loop.
[0021] Preferably, the loop is formed substantially as a rectangle.
[0022] Preferably, between adjacent sides of the rectangle, a radiused or rounded corner is provided.
[0023] Preferably, the first and second surfaces of the body are parallel to the plane of the loop.
[0024] Preferably, an orientation tab is provided at a point on the loop.
[0025] Preferably, the sealing element is formed of a resilient material.
[0026] Preferably, the sealing element is formed of rubber. Any suitable material may be used depending on the application and environmental considerations.
[0027] Preferably, the sealing element is formed of Ethylene Propylene
[0028] Thermoplastic Rubber.
[0029] Preferably, the sealing element is formed integrally as a single piece.
[0030] The sealing element may be formed in a mould.
DRAWINGS
[0031] The present invention will now be described by way of example with reference to and as illustrated in the accompanying drawings, in which:
[0032] FIG. 1 shows a plan view of a sealing element;
[0033] FIG. 2 shows an end side view of the sealing element of FIG. 1 ;
[0034] FIG. 3 shows a cross-section along section A-A of FIG. 1 ;
[0035] FIG. 4 shows a cross-section detail C on one side of the sealing element at section A-A as shown in FIG. 3 ;
[0036] FIG. 5 shows a cross-section detail B of a second side of the sealing element at section A-A as shown in FIG. 3 ;
[0037] FIG. 6 shows an isometric view of the sealing element of FIG. 1 ;
[0038] FIG. 7 shows an exploded view of the sealing element of FIG. 1 in a keypad assembly;
[0039] FIG. 8 shows a cross section of the keypad assembly of FIG. 7 in assembled form; and
[0040] FIG. 9 shows a cross-section detail D of the sealing element in the keypad assembly shown in FIG. 8 .
DETAILED DESCRIPTION
[0041] FIG. 1 shows a plan view of a sealing element shown generally at 1 in accordance with a preferred embodiment of the present invention. The sealing element 1 is formed as a closed generally rectangular loop or ring with a through aperture 13 . The sealing element comprises two lateral opposing sides, 2 a, 2 b and two opposing transverse sides 3 a, 3 b. The lateral sides 2 a, 2 b and the transverse sides 3 a, 3 b are connected to each other via radiused or rounded corner sections 4 a, 4 b, 5 a and 5 b.
[0042] Although not limited to precise dimensions, in the embodiment of the sealing element 1 shown in FIG. 1 , the width of the aperture 13 between the lateral sides 2 a and 2 b is 65.8 mm and the width of the aperture 13 between the two transverse sides 3 a, 3 b is 67.6 mm. The sealing element can be sized according to application.
[0043] The sealing element 1 comprises an orientation tab 6 , which in the embodiment shown, is in the form of a rectangular tab which extends along one of the transverse sides 3 b of the sealing element 1 .
[0044] FIG. 2 shows an end side view of the sealing element 1 as shown in FIG. 1 . The sealing element 1 comprises a first sealing part 8 c and a third sealing part 8 d. The first and third sealing parts 8 c, 8 d are inclined relative to the plane of the extent of the rectangular loop of the sealing element 1 . The sealing element 1 further comprises a second sealing part 9 c and a fourth sealing part 9 d which extend in a direction substantially perpendicular to the plane of the extent of the rectangular loop of the sealing element 1 .
[0045] FIG. 3 shows a cross section A-A through the sealing element as shown in FIG. 1 . At the top end of the sealing element 1 , the sealing orientation tab 6 is shown. The cross-section shows the profile of the first sealing part 8 a and the third sealing part 8 b. The cross section also shows the second sealing part 9 a and the fourth sealing part 9 b. The first, second, third and fourth sealing parts extend around the entire circumference of the loop of the sealing element 1 . Accordingly, the first sealing part 8 a and third sealing part 8 b in highlighted detail C correspond with the first sealing part 8 d and third sealing part 8 c respectively in highlighted detail B. Similarly, the second sealing part 9 a in detail C corresponds with the second sealing part 9 d in detail B and the fourth sealing part 9 b in detail C corresponds with the fourth sealing part 9 c in detail B.
[0046] FIG. 4 shows a cross section of the detail C shown in FIG. 3 . In cross-section, the sealing element 1 comprises a body 7 a. The body 7 a is formed, in cross section, substantially as a rectangle. The body 7 a has first and second parallel planar sides. In the embodiment shown, the first sealing part 8 a is connected to the first side of the body 7 a and the third sealing part 8 b is connected to second side of body 7 a. Each of the first and third sealing parts 8 a, 8 b are connected to the body 7 a on directly opposing sides of the body 7 a. The first and third sealing parts 8 a, 8 b are orientated, in their unbiased state, i.e. when not displaced, at an angle to the first and second parallel surfaces of the body 7 a respectively. Each of the first and third sealing parts 8 a, 8 b are formed as a tapered protrusion, which tapers from the end connected to the body 7 a to the free end of the sealing part 8 a, 8 b.
[0047] On the outermost side, i.e. the side facing away from the body 7 a, of each of the sealing parts 8 a, 8 b, a sealing surface 12 a, 12 b is provided. The sealing parts 8 a, 8 b are formed of a resilient material and are angularly displaceable with respect to the first and second parallel sides of the body 7 a such that the angle between the innermost sides of the first and third sealing parts 8 a, 8 b is reduced when the sealing element is displaced, for example, when the sealing element 1 is placed against a surface.
[0048] In their unbiased state, the sealing parts 8 a, 8 b are orientated at an angle of less than 90° with the first and second surfaces of the body 7 a. In their unbiased state, the surfaces of the first and third sealing parts 8 a, 8 b are substantially planar.
[0049] Spaced from the first and third sealing parts 8 a, 8 b, second and fourth sealing parts 9 a, 9 b are provided. In the embodiment shown, the second and fourth sealing parts 9 a, 9 b are formed as protrusions which extend substantially perpendicular the first and second surfaces of the body 7 a. The second and fourth sealing parts 9 a, 9 b are formed with a rounded, generally semi-circular profile. In the unbiased state of the first and third sealing parts 8 a, 8 b, the free ends of the first and third sealing parts 8 a, 8 b extend laterally further than the extent of the second and fourth sealing parts 9 a, 9 b from the first and second opposing parallel surfaces of the body 7 a.
[0050] Beyond the second and fourth sealing parts 9 a, 9 b on one side of the sealing element 1 the orientation tab 6 is provided. At the innermost side or end of the sealing element, a stepped or irregular profile 11 a, 11 b is provided. This profile facilitates the removal of the sealing element 1 from a mould during a preferred method of manufacture.
[0051] The profile of the sealing element 1 in cross section is substantially symmetrical along its centre line, except for the stepped profile ends 11 a, 11 b.
[0052] FIG. 5 shows the detailed view B of the cross section shown in FIG. 3 . As previously outlined, in the embodiment shown, the sealing parts extend around the entire circumference of the rectangular loop and the sealing parts shown in FIG. 5 correspond with those shown in FIG. 4 . As such, the parts shown in FIG. 5 function similarly to the parts shown in FIG. 4 . However, in FIG. 5 , no orientation tab is provided.
[0053] The width of the body 7 a of the sealing element is reduced for a part of the body 7 a which extends beyond the second and fourth sealing part 9 a, 9 b, 9 c, 9 d.
[0054] FIG. 6 shows an isometric view of the sealing element 1 . The orientation tab 6 can be shown located along one side of the rectangular loop of the sealing element 1 . The orientation tab 6 facilitates assembly of the sealing element with other components.
[0055] FIG. 7 shows the sealing element in an exploded view of an assembly keypad unit. The assembly includes a keypad unit 20 , a mounting panel 30 and a securing bracket 35 . The mounting panel 30 has an aperture 32 . The aperture 32 in the mounting panel 30 is substantially rectangular in form. The keypad unit 20 includes components which protrude, when assembled, through the aperture 32 in the mounting panel 30 . The sealing element 1 is provided around the aperture 32 of the mounting panel 30 on a first side 31 of the mounting panel. The securing bracket 35 is provided with a plurality of fixing holes 37 a, 37 b, 37 c to receive, fixing means, in the embodiment, screws or bolts 36 a, 36 b, 36 c. As shown in FIG. 7 , the orientation tab 6 of the sealing element 1 is provided along the lowermost edge, in use, of the sealing element 1 .
[0056] FIG. 8 shows the keypad unit in assembled form. The sealing element 1 can be seen positioned between the side or surface 31 of the mounting panel 30 and a rear side surface 21 of the keypad unit 20 . The surface of 31 of the mounting panel 30 is substantially planar and parallel with the rear side surface 21 of the keypad unit.
[0057] The sealing element 1 is provided in the assembly to prevent the ingress of foreign objects or other environmental products, such as oil, water or dust to the internal workings of the keypad unit 20 . The sealing unit provides a seal between the surface 31 of the mounting panel 30 and the rear side 21 of the keypad unit 20 . The screws 36 b, serve to hold the securing bracket 35 , the mounting panel 30 and the keypad unit 20 together.
[0058] FIG. 9 shows the detail D of FIG. 8 . The sealing element 1 is shown positioned between the surface 31 of the mounting panel 30 and a rear surface 21 of the keypad unit 20 . As can be seen in FIG. 9 , the second and fourth sealing parts 9 c, 9 d which are formed with a rounded profile, extend substantially perpendicularly from the first and second surfaces of the body 7 b and lie in contact with the surface 31 of the mounting panel 30 and the rear surface 21 of the keypad unit 20 .
[0059] The first and third sealing parts 8 c, 8 d are shown in their unbiased state. However, in use, when the sealing element 1 is positioned between the surfaces 31 , 21 of the mounting panel 30 and keypad unit 20 respectively, the first and third sealing parts 8 c, 8 d will be angularly displaced and deformed such that the first and third sealing parts generally follow the profile schematically represented by the dash lines 8 c′, 8 d′.
[0060] When the sealing element 1 is in place, the second and fourth sealing parts 9 c, 9 d are provided at the outermost sides of the sealing element 1 . In use, the second and fourth sealing parts 9 c, 9 d provide the first seal or defence against the ingress of, for example, fluid, water or dust. Even if the water or dust should pass the second or fourth sealing parts 9 c, 9 d, the first and third sealing parts 8 c, 8 d provide a second additional seal. When deformed, the outermost surfaces 12 a, 12 b of the first and third sealing part 8 c, 8 d lie against the surface 31 of the mounting panel 30 and the innermost surface 21 of the keypad unit 20 respectively.
[0061] Depending on the environmental conditions, if there is increased pressure of fluid, for example water, which has passed by the outermost sealing parts, i.e. the second and fourth sealing parts 9 c, 9 d, this will act against the innermost surfaces of the first and third sealing parts 8 c, 8 d. The orientation of the first and third sealing parts 8 c, 8 d provides a pocket or cavity 14 a, 14 b between the first and second surfaces of the body 7 b and the innermost surfaces of the first and third sealing parts 8 c, 8 d. The fin-like profile of the first and second sealing parts 8 c, 8 d and a build up in fluid pressure in the pocket 14 a, 14 b serves to press the first and second sealing parts 8 c, 8 d increasingly firmly against the adjacent surfaces 31 , 21 of the mounting panel 30 and keypad unit 20 resulting in an improved seal.
[0062] Because the first and third sealing parts 8 c, 8 d are angularly displaceable and, in use, their outermost surfaces 12 a, 12 b provide a sealing surface against component parts placed adjacent thereto, a larger surface contact area can be provided.
[0063] Because the first and third sealing parts 8 c, 8 d are angularly displaceable and resilient in a form, the sealing element can contend with adjacent surfaces which are not perfectly planar in form.
[0064] Although in the embodiment shown, a symmetric sealing element 1 has been shown, it is also envisaged that a sealing element could be provided with only one of the first tapered sealing parts 8 c, 8 d with the other side being provided, for example, with an adhesive planar surface. The sealing element may also be provided with just one of the first sealing parts and/or may be provided with one or more of the second sealing parts.
[0065] The sealing element 1 may be formed integrally of a single piece of homogeneous, resilient, material. In the embodiment shown, the sealing element 1 is formed of a rubber material, for example ethylene propylene thermoplastic rubber (EPTR). The choice of materials is however dependent on the application and any suitable material may be used.
[0066] The present invention may be carried out in various ways and various modifications are envisaged to the embodiments described without extending outside the scope of the invention as defined in the accompanying claims.
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A sealing element ( 1 ) comprising, in cross-section, a body ( 7 a ) and a first sealing part ( 8 a ).The first sealing part ( 8 a ) providing a sealing face ( 12 a ), the first sealing part being connected to and angularly and resiliently displaceable relative to a first surface of the body ( 7 a ).
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BACKGROUND OF THE INVENTION
The most common type of genetic variation is single nucleotide polymorphism (SNP), which may include polymorphism in both DNA and RNA a position at which two or more alternative bases occur at appreciable frequency in the people population (>1%). Base variations with the frequency <1% are called point mutations. For example, two DNA fragments in the same gene of two individuals may contain a difference (e.g., AAGTACCTA to AAGTGCCTA) in a single nucleotide to form a single nucleotide polymorphism (SNP). Typically, there exist many single nucleotide polymorphism (SNP) positions (about 1/1000 th chance in whole genome) in a creature's genome. As a result, single nucleotide polymorphism (SNP) and point mutations represent the largest source of diversity in the genome of organisms, for example, a human.
Most single nucleotide polymorphisms (SNP) and point mutations are not responsible for a disease state. Instead, they serve as biological markers for locating a disease on the human genome map because they are usually located near a gene associated with a certain disease. However, many mutations have been directly linked to human disease and genetic disorder including, for example, Factor V Leiden mutations, hereditary haemochromatosis gene mutations, cystic fibrosis mutations, Tay-Sachs disease mutations, and human chemokine receptor mutations. As a result, detection of single nucleotide polymorphisms (SNPs) and similar mutations are of great importance to clinical activities, human health, and control of genetic disease.
Neutral variations are important, for example, because they can provide guideposts in the preparation of detailed maps of the human genome, patient targeted drug prescription, and identify genes responsible for complex disorder. Moreover, since genetic mutation of other species (e.g., bacteria, viruses, etc.) can also be regarded as a type of single nucleotide polymorphism (SNP), the detection of single nucleotide polymorphism (SNP) can also be used to diagnosis the drug resistance, phenotype/genotype, variants and other information of microorganisms that may be useful in clinical, biological, industrial, and other applications.
There are several methods for detecting single nucleotide polymorphism (SNP) and mutations. The invader assay method is a sensitive method for single nucleotide polymorphism detection and quantitative determination of viral load and gene expression. In the basic invader assay, two synthetic oligonucleotides, the invasive and signal probes, anneal in tandem to the target strand to form the overlapping complex, which may be recognized by a flap endonuclease (FEN).
However, most of the methods are not suitable to be adapted to the platform of automated high-throughput assays or to multiplex screening.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention may be best understood by referring to the following description and accompanying drawings, which illustrate such embodiments. In the drawings:
FIG. 1 illustrates an exemplary single nucleotide polymorphism (SNP) invader assay mechanism.
FIG. 2 illustrates an exemplary monoplex solid-phase invasive cleavage reaction.
FIG. 3 illustrates another exemplary monoplex solid-phase invasive cleavage reaction.
FIG. 4 illustrates an exemplary biplex solid-phase invasive cleavage reaction.
FIG. 5 illustrates an exemplary instrumentation configuration and chip design.
FIG. 6 illustrates a second exemplary chip design.
FIG. 7 illustrates an exemplary solid phase carrier.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method and an apparatus for determining the highly sensitive multiplex single nucleotide polymorphism and mutation detection using a real time invader assay microarray platform. This method may be used for real time analysis in which the polymerase chain reaction (PCR) method may be used to generate amplified nucleic acid products to the detectable level in a short time, typically less than 2 hours. As a result, the method is suitable for the real time analysis. This method is also very sensitive. For example, the structure-specific cleavage is highly sensitive to sequence mismatches and uses flap endonuclease (FEN) activity to detect the single nucleotide polymorphism (SNP) in a target nucleic acid. This method is a quantitative assay of the specific target in the sample. The method is a simple operation, which allows for an integrated design to eliminate the transfer step after the polymerase chain reaction (PCR) and wash step after the invader single nucleotide polymorphism (SNP) assay. The method affords minimum cross-contamination because the polymerase chain reaction (PCR) and single nucleotide polymorphism (SNP) assay are performed in the integrated, airtight chamber. As a result, the amplified nucleic acid of different templates would not cross-contaminate each other. Further, the method poses very little biosafety hazard and reduces the chemical disposal related issues by using a closed reaction chamber.
Unless otherwise indicated, the words and phrases presented in this document have their ordinary meanings to one of skill in the art. Such ordinary meanings can be obtained by reference to their use in the art and by reference to general and scientific dictionaries, for example, Webster's Third New International Dictionary , Merriam-Webster Inc., Springfield, Mass., 1993 and Hawley's Condensed Chemical Dictionary, 14 th edition, Wiley Europe, 2002.
The following explanations of certain terms are meant to be illustrative rather than exhaustive. These terms have their ordinary meanings given by usage in the art and in addition include the following explanations.
As used herein, the term “and/or” refers to any one of the items, any combination of the items, or all of the items with which this term is associated.
As used herein, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise.
As used herein, the term “buffer solution” refers to a solution that resists changes in the pH. A suitable reaction buffer for a microarray is described in PCT Patent Application Publication No. WO 2008/080254.
As used herein, the term “evanescent” refers to a nearfield standing wave exhibiting exponential decay with distance. A suitable evanescent wave system that may be used in the practice of this invention is described, for example, in U.S. Patent Application Publication No. 2006/0088844. A suitable microarray reader based on evanescent wave is described in PCT Patent Application Publication No. WO 2008/092291.
As used herein, the term “flap endonuclease (FEN)” refers to a type of nucleolytic enzyme that acts as both as a 5′-3′ exonuclease and a structure specific endonuclease on specialized DNA structures that occur during the biological processes of DNA replication, DNA repair, and DNA recombination.
As used herein, the term “hybridization” refers to the pairing of complementary nucleic acids.
As used herein, the term “invader assay” refers to an assay method in which a structure-specific flap endonuclease (FEN) cleaves a three-dimensional complex formed by hybridization of allele-specific overlapping oligonucleotides to target DNA containing a single nucleotide polymorphism (SNP) site.
As used herein, the term “invader probe” refers to an oligonucleotide that is complementary to the target sequence 3′ of the polymorphic site and ends with a non-matching base overlapping the single nucleotide polymorphism (SNP) nucleotide; it can either be tethered onto a solid phase carrier or in a reaction solution.
As used herein, the term “linker” refers to a carbon chain, which may include other elements that covalently attaches two chemical groups together.
As used herein, the term “microarray” is a linear or two-dimensional microarray of discrete regions, each having a defined area, formed on the surface of a solid support.
As used herein, the term “nucleic acid” refers to any nucleic acid containing molecule including, but not limited to, DNA or RNA.
As used herein, the term “nucleic acid sequence” refers to an oligonucleotide, nucleotide or polynucleotide, and fragments or portions thereof, and to DNA or RNA of genomic or synthetic origin which may be single or double stranded, and represent the sense or antisense strand.
As used herein, the term “polymerase chain reaction (PCR)” refers to the method of K. B. Mullis, U.S. Pat. Nos. 4,683,195, 4,683,202, and 4,965,188.
As used herein, the term “primer” refers to a single-stranded polynucleotide capable of acting as a point of initiation of template-directed DNA synthesis under appropriate conditions.
As used herein, the term “probe” refers to a nucleic acid capable of binding to a target nucleic acid of complementary sequence through one or more types of chemical bonds, usually through complementary base pairing, usually through hydrogen bond formation, thus forming a duplex structure.
As used herein, the term “sequence variation” refers to differences in nucleic acid sequence between two nucleic acids.
As used herein, the term “single nucleotide polymorphism (SNP)” refers to a DNA sequence variation occurring when a single nucleotide—A, T, C, or G—in the genome (or other shared sequence) differs between members of a species (or between paired chromosomes in an individual).
As used herein, the term “signal probe” refers to a DNA sequence which may be cleaved by the enzyme at the site of its overlap with the 3′ end of the invasive probe. This cleavage releases the noncomplementary 5′ flap of the signal probe plus one nucleotide of its target-specific region. The cleaved 5′ flap serves as a signal for the presence, and enables quantitative analysis, of the specific target in the sample. The signal probe is tethered onto the solid phase carrier.
As used herein, the term “substrate” refers to material capable of supporting associated assay components (e.g., assay regions, cells, test compounds, etc.).
As used herein, the term “target nucleic acid” refers to a polynucleotide. The polynucleotide is genetic material including, for example, DNA/RNA, mitochondrial DNA, rRNA, tRNA, mRNA, viral RNA, and plasmid DNA.
As used herein, the term “thermostable” refers to an enzyme, such as a 5′ nuclease, indicates that the enzyme is functional or active (i.e., can perform catalysis) at an elevated temperature, for example, at about 55° C. or higher.
As used herein, the term “melting temperature (T m )” refers to the temperature at which a population of double-stranded nucleic acid molecules becomes half dissociated into single strands.
The present invention provides a quantitative method for detecting a single nucleotide polymorphism in a target nucleic acid. The method includes: (a) providing an amplified target nucleic acid suspected of having a single polynucleotide polymorphism, wherein a target nucleic acid is amplified by a polymerase chain reaction; (b) annealing an invader probe and a signal probe to a single-strand of the amplified target nucleic acid suspected of having a single polynucleotide polymorphism to provide a sample complex, wherein the invader probe includes sequences selected to anneal to the single-strand of the amplified target nucleic acid 5′ to the single polynucleotide polymorphism and a 3′ most nucleotide that does not anneal to the single polynucleotide polymorphism, wherein the signal probe includes a fluorescent label linked to sequences selected to not anneal to the single-strand of the amplified target nucleic acid or to the invader probe linked to sequences selected to anneal to the target nucleic acid with a single nucleotide polymorphism, wherein the signal probe includes a fluorescence quencher linked to sequences selected to anneal to the single-strand of the amplified target nucleic acid or to the invader probe linked to sequences selected to anneal to the single-strand of the amplified target nucleic acid suspected of having a single polynucleotide polymorphism; (c) contacting the sample complex with a flap endonuclease to activate a fluorescence response; wherein if the signal probe anneals to the single-strand of the amplified target nucleic acid at a single polymorphic nucleotide, the flap endonuclease cleaves the signal probe 3′ to the single polymorphic nucleotide producing a cleaved 5′ flap sequence that produces the fluorescent response; and (d) detecting the fluorescence response.
In one embodiment, the providing an amplified target nucleic acid suspected of having a single polynucleotide polymorphism includes: (i) denaturing the target nucleic acid to provide a pair of single-stranded target nucleic acids; (ii) annealing a primer to the each single-stranded target nucleic acid; and (iii) extending each primer annealed to each single-stranded target nucleic acid to provide an amplified target nucleic acid. In another embodiment, the method further includes analyzing the fluorescence response.
In one embodiment, the signal probe is immobilized on an upper surface of a substrate or both the signal probe and the invader probe are immobilized on an upper surface of a substrate.
The present invention provides another quantitative method for detecting a single nucleotide polymorphism in a target nucleic acid. The method includes: (a) providing an amplified target nucleic acid suspected of having a single polynucleotide polymorphism, wherein a target nucleic acid is amplified by a polymerase chain reaction; (b) annealing an invader probe and a signal probe to a single-strand of the amplified target nucleic acid suspected of having a single polynucleotide polymorphism to provide a sample complex, wherein the invader probe includes sequences selected to anneal to the single-strand of the amplified target nucleic acid 5′ to the single polynucleotide polymorphism and a 3′ most nucleotide that does not anneal to the single polynucleotide polymorphism; wherein the signal probe includes sequences selected to not anneal to the single-strand of the amplified target nucleic acid or to the invader probe linked to sequences selected to anneal to the target nucleic acid with a single nucleotide polymorphism; (c) contacting the sample complex with a flap endonuclease to provide a 5′ flap sequence, wherein if the signal probe anneals to single-strand of the amplified target nucleic acid at a single polymorphic nucleotide, the flap endonuclease cleaves the signal probe 3′ to the single polymorphic nucleotide to provide the 5′ flap sequence;(d) annealing the 5′ flap sequence to a probe immobilized on an upper surface of a substrate, wherein the probe includes a nucleotide sequence that is complementary to the 5′ flap sequence and to a fluorescent energy transfer cassette positioned a 5′ end of the probe and includes a fluorophore and a fluorescence quencher;(e) cleaving the fluorescent energy transfer cassette between the fluorophore and the fluorescence quencher with a flap endonuclease to activate a fluorescence response; and (f) detecting the fluorescence response.
In one embodiment, the providing an amplified target nucleic acid suspected of having a single polynucleotide polymorphism includes: (i) denaturing the target nucleic acid to provide a pair of single-stranded target nucleic acids; (ii) annealing a primer to the each single-stranded target nucleic acid; and (iii) extending each primer annealed to each single-stranded target nucleic acid to provide an amplified target nucleic acid. In another embodiment, the method further includes analyzing the fluorescence response.
In one embodiment, the probe is printed and immobilized onto the substrate using a micro-array printer. In another embodiment, the substrate includes silicon, glass, quartz, a ceramic, a rubber, a metal, a polymer, a hybridization membrane, or a combination thereof. In yet another embodiment, the substrate is chemically modified with a reagent selected from a silane, avidin, poly-L-lysine, streptavidin, a polysaccharide, a mercaptan, or a combination thereof.
In one embodiment, the probe includes a linker with a sulfhydryl (RSH), amino (NH 2 ), hydroxyl (OH), carboxaldehyde (CHO), or carboxylic acid (COOH) group at the 3′ end. In another embodiment, the linker includes about a ten nucleotide random oligomer. In yet another embodiment, the probe is immobilized onto a silanized glass substrate with the sulfhydryl (RSH) group at the 3′ end.
The present invention further provides an apparatus. The apparatus includes: a closed reactor including: a substrate having opposing first and second planar opposing surfaces, the substrate having a cavity and a refractive index greater than a refractive index of water; a buffer layer arranged over the first planar surface of the substrate; a cover plate arranged over the buffer layer and the cavity, the cover plate in combination with the cavity and buffer layer defining a reaction chamber; and at least one inlet port and at least one outlet port to communicate with the reaction chamber through the substrate to enable the passage of fluid from an external source into and through the reaction chamber; a temperature control system coupled to the closed reactor to cycle the temperature of a buffer solution contained within the closed reactor, wherein the buffer solution is substantially in contact with the first surface of the substrate and being capable of sustaining a plurality of polymerase chain reactions, a plurality of hybridization reactions, containing one or more primers, one or more dNTPs, a target nucleic acid suspected of having a single polynucleotide polymorphism, a signal probe, an invader probe, and a flap endonuclease; a light source coupled to the closed reactor to provide a ray of light having a wavelength chosen to activate a fluorophore immobilized on the first surface of the substrate, incident on an interface between the substrate and the buffer solution at an angle chosen to propagate an evanescent wave into the buffer solution; and a detector coupled to the closed reactor to detect a fluorescent response.
In one embodiment, the detector is mobile and capable of sequentially detecting fluorescent light emitted by the fluorophore. In another embodiment, the closed reactor is mobile and capable of being sequentially addressed by the detector. In yet another embodiment, the detector includes a camera, a charge-coupled device, a charge-injection device, a complementary metal-oxide-semiconductor (CMOS) device, a video camera, a silicon photo-cell, a photodiode, an avalanche photodiode, a photo-multiplier tube, or a combination thereof.
FIG. 1 illustrates an exemplary single nucleotide polymorphism (SNP) invader assay mechanism. The invader assay is a sensitive method for single nucleotide polymorphism detection and also for quantitative determination of viral load and gene expression. In the basic invader assay, two synthetic oligonucleotides ( 101 , 102 ), the invader probe ( 103 ) and signal probes ( 104 , 105 ), anneal in tandem to the target strand to form an overlapping complex, which can be recognized by a flap endonuclease (FEN). The invader probe ( 103 ) includes a nucleotide, which in this example, is not A. The flap endonuclease (FEN) cleaves the signal probe ( 104 ) at the site of its overlap with the 3′ end of the invader probe ( 103 ). This cleavage releases the noncomplementary 5′ flap ( 107 ) of the signal probe ( 104 ) plus one nucleotide of its target-specific region. The cleaved 5′ flap ( 107 ) serves as a signal for the presence, and enables quantitative analysis, of the specific target in the sample.
FIG. 2 illustrates an exemplary monoplex solid-phase invasive cleavage reaction in which an invader probe ( 201 ) for each array location is added to the reaction with a target nucleic acid ( 202 ) and flap endonuclease (FEN). If the target nucleic acid probe ( 203 ), which is attached to the substrate ( 204 ), is designed as a fluorescence resonance energy transfer (FRET) molecule containing a fluorophore ( 205 ) at the 5′-end and an internal quencher molecule ( 206 ), the cleavage reaction separates the fluorophore ( 205 ) from the quencher ( 206 ) and generates a measurable fluorescent signal.
FIG. 3 illustrates another exemplary monoplex solid-phase invasive cleavage reaction in which an invader probe ( 301 ) and a target nucleic acid probe ( 302 ) are tethered to the solid phase ( 303 ), so that only a sample ( 304 ) and flap endonuclease (FEN) are added for array processing.
FIG. 4 illustrates an exemplary biplex solid-phase invasive cleavage reaction in which different alleles ( 401 , 402 ) may be detected by different hairpin-like probes ( 403 , 404 ), respectively. For example, a signal probe may have two regions: a target-specific region ( 405 ) and a 5′ flap region ( 406 ). The target-specific region ( 405 ) of each signal probe may be complementary to the target sequence ( 401 or 402 ) and the melting temperature of the signal probe-target duplex may be close to the assay temperature. The 5′ flap region ( 406 ) of the signal probe may be non-complementary to both the target ( 401 and/or 402 ) and the invader probe ( 407 ) sequence. The 5′ flap region ( 406 ) of the signal probe may serve as a signal for the presence of the target nucleic acids ( 401 and/or 402 ) to enable the quantitative analysis of the single nucleotide polymorphism (SNP). Further, the 5′ flap region ( 406 ) of the signal probe may be designed to anneal to the hairpin-like immobilized probe ( 403 and/or 404 ) on the surface facing the fluorophore and the quencher at the assay temperature.
An invader probe ( 407 ) may be complementary to the target nucleic acid sequence 3′ to the polymorphic site and ends with a non-matching base, which overlaps the single nucleotide polymorphism (SNP) nucleotide. An invader probe ( 407 ) may be designed to anneal to the target DNA ( 401 and/or 402 ) at the assay temperature.
A target nucleic acid probe ( 403 and/or 404 ) may be a hairpin-like immobilized probe. A hairpin-like immobilized target nucleic acid probe may contain a signal dye molecule ( 408 ) (e.g., fluorophore) and a quencher dye molecule ( 409 ) pair, i.e., a fluorescence resonance energy transfer (FRET) cassette. Cleavage of the fluorescence resonance energy transfer (FRET) cassette releases the signal dye molecule ( 408 ) (e.g., fluorophore), which produces a fluorescent signal when it is separated from the quencher ( 409 ). The hairpin-like immobilized target nucleic acid probe may be arrayed and tethered on the solid phase carrier ( 410 ) by the linker ( 411 ).
For example, if probe 2 matches the single nucleotide polymorphism (SNP) allele present in the target DNA, the hairpin-like probe 2 located in another array position, which has sequences complementary to those in probe 2 , is cleaved and generates fluorescence in the other array position. This distinction is highly specific with only minimal unspecific cleavage of the mismatch probe. Each flap sequence is specific for one FRET cassette molecule, and thus generates a distinct fluorescent signal.
To employ an invader assay on a microarray, the hairpin-like synthetic oligonucleotides ( 403 ) are immobilized on a glass slide surface ( 410 ) via a chemical linker ( 411 ) and are present in an excess quantity. The invader probe ( 407 ) may be designed to anneal to the target DNA ( 401 ), and the cleaved 5′ flap ( 406 ) may be designed to anneal to the hairpin-like immobilized probe ( 403 ) at the assay temperature. In contrast, the signal probe ( 405 ) may be designed to have a melting temperature of the assay temperature. During annealing of the cleaved 5′ flap ( 406 ) to the hairpin-like immobilized probe ( 403 ), an enzyme can cleaves the fluorescence resonance energy transfer (FRET) cassette, the quencher ( 409 ) detaches, and a fluorescence signal may be produced. The fluorescent signal may be excited by the laser and captured by the charge-coupled device (CCD), as shown in FIG. 5 .
FIG. 5 illustrates an exemplary instrumentation configuration and chip design. The configuration includes, for example, a laser ( 501 ), a shutter ( 502 ), a chamber ( 503 ), a heater ( 504 ), probes ( 505 ), a solid phase carrier ( 506 ), a lens ( 507 ) and a detector ( 508 ). In one embodiment, the polymerase chain reaction (PCR) and invader assay reaction are performed in the same chamber ( 503 ). The instrumentation may detect the single nucleotide polymorphism (SNP) by the invader assay method after each polymerase chain reaction (PCR) cycle, or detect the single nucleotide polymorphism (SNP) after the polymerase chain reaction (PCR) cycles generate sufficient nucleic acid. The solid phase carrier ( 506 ) may be transparent and be able to be chemically modified. Suitable solid phase carriers include, for example, glass and plastic. The probes ( 505 ) of single nucleotide polymorphism (SNP) array are tethered onto the solid phase carrier ( 506 ). In this embodiment, a laser ( 501 ) may be used to excite the fluorescent signals of the cleaved probes while a detector ( 508 ) may be used capture the fluorescent signals. In one embodiment, the evanescent field of the laser light is a non-transverse wave having components in all spatial orientations, decreasing in field intensity with penetration into medium of n 2 .
FIG. 6 illustrates another exemplary chip design. This chip design includes, for example, a biochip ( 601 ), a Heater A ( 602 ), a Heater B ( 603 ), probes ( 604 ), a solid phase carrier ( 605 ), a single nucleotide polymorphism (SNP) assay chamber ( 606 ), and a polymerase chain reaction (PCR) chamber ( 607 ). In one embodiment, the biochip ( 601 ) includes a single nucleotide polymorphism (SNP) assay reaction chamber ( 606 ) and a polymerase chain reaction chamber ( 607 ), which are in mutual contact by fluid channels. The fluid may be moved through the channels (not shown) from the polymerase chain reaction (PCR) chamber ( 607 ) to the single nucleotide polymorphism (SNP) assay chamber ( 606 ) after the polymerase chain reaction (PCR) process is accomplished. In one embodiment, Heater A ( 602 ) controls the polymerase chain reaction (PCR) temperature cycles for the polymerase chain reaction (PCR) chamber ( 607 ), for example, cycling the temperature of the fluid from 90° C. to 60° C. to 72° C. Heater B ( 603 ) controls the single nucleotide polymorphism (SNP) assay temperature for the single nucleotide polymorphism (SNP) assay chamber ( 606 ), for example, holding the temperature of chamber ( 606 ) at 64° C.
FIG. 7 illustrates an exemplary solid phase carrier. In one embodiment, the solid phase carrier ( 701 ) may be transparent and capable of chemical modification. Suitable solid phase carriers include, for example, glass and plastic. The probes ( 702 ) of the single nucleotide polymorphism (SNP) array are tethered onto the solid phase carrier ( 701 ).
An example of the highly sensitive multiplex single nucleotide polymorphism and mutation detection using a real time invader assay microarray platform is given below. For example, genes involved in blood pressure regulation in humans may be analyzed. The first single nucleotide polymorphism (SNP), CD36, is located in exon 14 past the stop codon in the gene. The second single nucleotide polymorphism (SNP), PTP03, is a synonymous change in exon 8 of the gene for protein tyrosine phosphatase 1β (PTPN1). Invader assays were designed using the Invader Creator software (Hologic, Inc, Bedford, Mass., USA). Exemplary probe designs are listed in attached Table 1.
In this example, all assays may be designed to be run at the same incubation temperature (65° C. for biplex assays, 63° C. for monoplex assays) and may be performed in the integrated chamber as shown in FIG. 5 . The probes of the biplex single nucleotide polymorphism (SNP) reaction may be the hairpin-like probes. In contrast, the probes of the monoplex single nucleotide polymorphism (SNP) reaction may be signal probes. The probes may be modified with a sulfhydryl (—SH) at 3′ end and synthesized. To reduce potential space hindrance, a linker made of 10 nucleotide (nt) random oligomer may be added at the 3′ end. Correspondingly, the sulfhydryl (—SH) group may be modified at the 3′ end. These probes may be spotted with an aspirate-dispensing arrayer, like Biodot Arrayer (Cartesian Technologies, Irvine, Calif., USA) or similar contact-spotting arrayers. The probes may be immobilized on a modified glass slide with the sulfhydryl (—SH) group, and the glass with the immobilized probes array may be assembled with a plastic piece to form a chamber to form a reaction chamber or reactor.
Inside the reactor, a polymerase chain reaction (PCR) and single nucleotide polymorphism (SNP) assay reaction may be carried out simultaneously. A small quantity of purified genomic DNA may act as the template of the reaction. These templates may be added into the reaction chamber together with deoxyribonecleotide triphosphates (dNTP), polymerase chain reaction (PCR) primer, Taq polymerase, thermostable flap endonucleases (FEN), invader probes, optional signal probe (if a biplex assay is desired) and an appropriate buffer which can sustain the amplification and the single nucleotide polymorphism (SNP) reaction. The chamber is filled with the reaction fluid and sealed with a set of rubber plugs. The chamber is heated and cooled with a semi-conductor cooler to the temperatures required for the polymerase chain reaction (PCR) cycles. The polymerase chain reaction (PCR) may be performed in a standard process. The amplified nucleic acid products act as the templates of the single nucleotide polymorphism (SNP) reaction. In a typical biplex invader assay reaction system, reaction liquid is denatured for 5 minutes at 95° C. and incubated for 20 minutes at 65° C. In a typical monoplex invader assay reaction system, reaction liquid is denatured for 5 minutes at 95° C. and incubated for 20 minutes at 63° C.
TABLE 1
Assay
Oligonucleotide
SNP
type
type
Sequence
CD36
Target sequence
3′- GGTTACTAATCTGCTTAACTAAGAAAGACACTGAGTAGTCAAG AAAGGACATTTTAAG
(allele 1)
TACAGAAC -5′ (SEQ ID NO: 1)
Target sequence
3′- GGTTACTAATCTGCTTAACTAAGAAAGACACTGAGTAGTCAAGA AAAGGACATTTTAAG
(allele 2)
TACAGAAC -5′ (SEQ ID NO: 2)
Biplex
Invader
5′-CCAATGATTAGACGAATTGATTCTTTCTGTGACTCATCAGTTCTT-3′
(SEQ ID NO: 3)
Signal probe 1
5′- TTTCCTGTAAAATTCATGTCTTGC -3′
(SEQ ID NO: 4)
Signal probe 2
5′- TTTCCTGTAAAATTCATGTCTTG -3′
(SEQ ID NO: 5)
Hairpin-like
SpSpSpSpSpSpSpSpSpSp-3′- GAGCAGAGCCTTTTGGCTC(F)TG
probe 1
CTCA(Q)CAGTTG-5′ (SEQ ID NO: 6)
Hairpin-like
SpSpSpSpSpSpSpSpSpSp-3′- GAGCAGAGCCTTTTGGCTC(F)TGCTCC
probe 2
(Q)CAGTTG-5′ (SEQ ID NO: 7)
Monoplex
Invader
5′-CCAATGATTAGACGAATTGATTCTTTCTGTGACTCATCAGTTCTT-3′
(SEQ ID NO: 8)
Signal probe 1′
5′-(Q) TT (F) TCCTGTAAAATTCATGTCTTG -3′-SpSpSpSpSpSpSpSp
SpSp (SEQ ID NO: 9)
Signal probe 2′
5′-(Q) TT (F) TCCTGTAAAATTCATGTCTTG -3′-SpSpSpSpSpSpSpSp
SpSp (SEQ ID NO: 10)
PTP03
Target sequence
3′- TGCTCCTGGACCTCGGGGGTGGT G CTCGTATAGGGGGGT -5′
(allele 1)
(SEQ ID NO: 11)
Target sequence
3′- TGCTCCTGGACCTCGGGGGTGGT CTCGTATAGGGGGGT -5′
(allele 2)
(SEQ ID NO: 12)
Biplex
Invader
5′-ACGAGGACCTGGAGCCCCCACCAT-3′ (SEQ ID NO: 13)
Signal probe 3
5′- GAGCATATCCCCCCA-3′ (SEQ ID NO: 14)
Signal probe 4
5′- GAGCATATCCCCCC-3′ (SEQ ID NO: 15)
Hairpin-like
SpSpSpSpSpSpSpSpSpSp-3′- GAGCAGAGCCTTTTGGCTCTGCTC
probe 3
TTCGACT-5′ (SEQ ID NO: 16)
Hairpin-like
SpSpSpSpSpSpSpSpSpSp-3′- GAGCAGAGCCTTTTGGCTCTGCTCTTCG
probe 4
ACT-5′ (SEQ ID NO: 17)
Monoplex
Invader
5′-CGAGGACCTGGAGCCCCACCAT-3′ (SEQ ID NO: 18)
Signal probe 3′
5′-(Q)CGCGCCGAGG GA (F) GCATATCCCCCCA -3′-SpSpSpSpSpSpSpSpSpSp
(SEQ ID NO: 19)
Signal probe 4′
5′-(Q)CGCGCCGAGG GA (F) GCATATCCCCCCA - 3′SpSpSpSpSpSpSpSpSpSp
(SEQ ID NO: 20)
Legend:
Underlined type in each target sequence indicates the region complementary to the invader oligonucleotide.
Italic type indicates sequence complementary to the probe.
The bold underlined type indicates base is the site of the single nucleotide polymorphism (SNP).
The bold type indicates the part of the signal probe is the cleaved part.
The bold italic underlined type indicates the part of the hairpin-like probe is complementary to the cleaved part of the correspondong signal probe.
F = Fluorophore; Q = quencher; Sp = hexaethylene glycol spacer.
During the single nucleotide polymorphism (SNP) invader assay reaction, the signal probe 1 ( 1 ′) is annealed to the CD36-allele 1. The resulting overlap with the invader oligonucleotide is recognized by a flap endonuclease (FEN) and the 5′-flap (marked in bold) is cleaved. In the monoplex reaction system, the quencher molecule of the signal probe 1 ′ will be separated from the fluorophore molecule. The separated quencher diffuses away from the bound fluorophore. The bound fluorophore releases a fluorescent signal upon activation with light of an appropriate wavelength. In the biplex reaction system, the 5′-flap of the signal probe 1 complementary to its hairpin-like probe and the overlap with the hairpin terminal is recognized by the flap endonuclease (FEN), which will cleave the nucleotides separating the quencher molecule from the fluorophore molecule. The fluorophore may be excited by light of an appropriate wavelength to produce a fluorescence response. As described above, a part of signal probe sequence is complementary to the target sequence, and in the biplex assay, the other part of signal probe is complementary to the hairpin-like probe. As a result of the high sensitivity of the flap endonuclease (FEN) to recognize the overlap structure, the mismatch associated with the single nucleotide polymorphism (SNP) will not initiate the subsequent cleavage reaction that leads to a fluorescent response. When the single nucleotide polymorphism (SNP) assay reaction is complete, the fluorescent signal of the cleaved probes is excited by the laser and recorded by the charge-coupled device. The allele type of the single nucleotide polymorphism (SNP) may be analyzed by the signal strength of probes. Although the above discussion refers to a single nucleotide polymorphism (SNP) detection, one of skill in the art would readily recognize that this technology may be expanded for multiple single nucleotide polymorphism (SNP) detection. Theoretically, for each single nucleotide polymorphism (SNP) site, a set of signal probe, invasive probe, and hairpin-like probe (for biplex reaction) may be prepared and used with one microchip.
All patents and publications referenced or mentioned herein are indicative of the levels of skill of those skilled in the art to which the invention pertains, and each such referenced patent or publication is hereby incorporated by reference to the same extent as if it had been incorporated by reference in its entirety individually or set forth herein in its entirety.
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A method and apparatus for real-time, simultaneous, quantitative measurement for detecting a single nucleotide polymorphism in a target nucleic acid is provided. This method involves combining a polymerase chain reaction (PCR) technique with invader assay technique.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods for recovering tar sands by establishing communication between an injection well and a production well penetrating a tar sand bed.
2. Description of the Prior Art
There are a number of known bitumen containing tar sand reservoirs scattered around the world. One of the largest of these is the deposit located in the Athabasca region of Alberta, Canada. The invention disclosed herein will operate in any tar sand bed; however, since the Athabasca tar sand deposit is well known the following discussion will mention it specifically.
The Athabasca tar sand deposit has a lateral area of several thousand square miles. The bitumen or oil bearing sandstone reservoir is exposed at ground surface is some areas of the deposit. Where this phenomenon occurs, open pit mining operations may take place. In these operations, oil and sand are separated in a plant. The greatest part of the deposit, however, is covered with overburden which can range up to 1000 feet in thickness. Where substantial overburden occurs, the deposit cannot be economically mined by open pit methods. Consequently, researchers in the field have worked toward developing an in situ method suitable for recovering the oil. The oil sand is mainly comprised of water wet quartz grains. The oil or bitumen is located in the interstices between the water sheathed grains and actually forms the matrix of the reservoir since the quartz grains are not in contact with one another.
The oil present in and recoverable from the Athabasca tar sands is usually a rather viscous material ranging in specific gravity from slightly below one to about 1.04 or somewhat greater. At a typical reservoir temperature, e.g., about 48° F, this oil is a plastic material having a viscosity exceeding several thousand centipoise. At higher temperatures such as above about 200° F, this oil becomes mobile with viscosities of less than about 343 centipoises. At reservoir temperatures then, it is evident that the oil cannot be pushed through the formation to a production well using conventional means such as a pressure gradient.
Thus, researchers have devised means for unlocking the subterranean tar sand so as to recover the contained oil. Most of these investigations have been concerned with converting the oil to a less viscous state so that it can be driven to and recovered from production wells using conventional pumping or gas lift methods. Many of these procedures are designed to heat the reservoir with steam or hot hydrocarbons so as to render the bitumen mobile. Other procedures involve spontaneously emulsifying the oil to form an oil and water emulsion and can be moved to production wells.
In these methods, the prior art teaches drilling production and injection wells into the formation and fracturing the tar sands horizontally to establish communication between the wells. After communication is established, the prior art methods then pump steam or an emulsifying fluid through the fracture system. One problem with these systems, is that the emulsion cools as it moves away from the hot zones surrounding the injection well and as it cools, the oil again solidifies to form an impermeable block in the fracture system. Another problem is that the tar sand even at temperatures from 40°-50° F is a plastic solid material which under the enormous overburden will slowly flow into the fracture zone thereby blocking it.
Thus, these prior art processes are hampered by the fact that the fracture will not maintain itself for long periods of time even though propped with extraneous materials. It is an object of our invention to present a method for fracturing a tar sand formation whereby the fracture is given rigidity and permanence.
SUMMARY OF THE INVENTION
The present invention is a method for fracturing a tar sand formation between an injection well and a production well in communication with the tar sand formation. The method comprises injecting a fluid into the injection well under sufficient pressure to fracture the tar sand formation between the injection well and the production well and then circulating a fluid between the injection and production wells which is at a temperature sufficiently low to freeze the water in the tar sands and to solidify the hydrocarbon portion of the tar sands. This circulating fluid may be the same as or different than the fluid used to create the fracture. The fracturing fluid should contain propping agents and the circulation of the circulating fluid should be maintained for a period of time sufficient to affect a considerable area away from the fracture face. The invention is also a method for recovering oil from a tar sand fractured in the above manner by circulating a solvent for the hydrocarbon in the created fracture between injection and production wells. The solvent is preferably at a temperature low enough to maintain the rigidity of the created fracture. The solvent carries the leached bitumen to the surface where it may be recovered.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method of our invention discloses a process for fracturing a tar sand deposit and rendering the area around the fracture rigid so that the fracture will not heal by plastic flow. This is accomplished by establishing communication, i.e., by fracturing the formation between an injection and production well and then contacting the created fracture with a cold fluid which is at a temperature sufficient to freeze the water in the formation and to solidify the bitumen. The method of the invention may have many variations all of which cannot be discussed here, but one skilled in the art may be able to devise an equivalent method which is in the scope of the invention.
In one embodiment of the invention, a fluid may be pumped into the injection well to fracture the formation. Then either the same fluid or another may be circulated at cold temperatures in the fracture zone to cool the formation so as to render it more rigid. This fracture and/or cooling fluid may be any fluid available to those in the field, including water, LPG, and cold gases still in a gaseous state such as carbon dioxide. The function of this cooling fluid is to remove heat from the formation thus lowering the temperature in the vicinity of the fracture zone. Thus, the cooling fluid should be at a temperature below original formation temperature. In a particular embodiment of the invention, the fluid should cool the fracture surfaces to a point where the water in the vicinity of the fracture zone is frozen and the bitumen is rigid. This fluid may be circulated for any length of time sufficient to perform the function of lowering the temperature a desired amount in a desired volume of reservoir. Once the formation is sufficiently cooled in the area of the fracture, propping agents would be introduced along with the cooling fluid to help support the fracture. Proppant may be introduced with the fracturing fluid. If proppant is introduced at a time much after the initial fracturing operation, care must be taken to maintain the fracture opening by pressure until proppant is introduced. These propping agents may be any of those known to those in the fracturing art. One unique propping agent could be fragments of solid carbon dioxide which would perform the function of not only supporting the fracture for a time, but also of cooling the formation and maintaining the temperature at a desired level.
Another embodiment of the invention is to establish communication between the injection well and production well with a gas prior to fracturing. This gas may be nitrogen, methane, carbon dioxide, or any number of gases available to those in the field, including exhaust gases. It has been found that in some cases a gas will establish communication in a tar sand bed more rapidly than a liquid thus facilitating the fracturing process.
Thus formed, the rigid fracture in the tar sand bed may be used as the vehicle for recovering oil from the tar sand formation in many conventional ways. One such method would be to introduce a hot fluid such as steam into the fracture zone, although this method would not be preferred since it would warm the fracture zone and cause the advantages of cooling the fracture zone to be lost. Another embodiment of the invention would be to circulate through the fracture zone a solvent for the bitumen in the formation. The solvent should preferably be at a low enough temperature so that the bitumen in the fracture zone is maintained in its rigid state. It is particularly preferred for the circulating solvent to be cold enough so that the water in the fracture zone remains frozen. This solvent will dissolve the bitumen in the fracture zone carrying it to the surface. If the solvent was sufficiently cold, it will also carry water to the surface in the form of ice crystals which could easily be separated from the dissolved bitumen without the problem of emulsification.
Any solvent capable of dissolving the viscous petroleum or bitumen contained in the formation to which the process is to be applied resulting in the formation of a single (liquid) phase solution of solvent and bitumen having a viscosity substantially less than the viscosity of the virgin bitumen may be used as the solvent of our process. Aliphatic or aromatic hydrocarbons capable of dissolving bitumen are suited for this process. Mixtures of aliphatic and aromatic hydrocarbons may also be used as well as hydrocarbons containing both aromatic and aliphatic characteristics. Suitable aromatic hydrocarbons include mononuclear and polynuclear species.
Aliphatic hydrocarbons, specifically linear or branched paraffinic hydrocarbons having from 4 to 10 carbon atoms, are suitable materials for use in practicing the process of the invention. For example, butane, pentane, hexane, heptane, octane, etc. and mixtures thereof as well as commercial blends such as natural gasoline will function as a satisfactory liquid solvent in many bitumen-containing formations.
Of course, a solvent used in this process should have a low freezing point, preferably below the freezing point of water in the formation. Also, it has been noted that some aliphatic solvents are not satisfactory bitumen solvents. Therefore, laboratory testing to choose a proper solvent is in order.
Mononuclear aromatic hydrocarbons, especially benzene, toluene, xylene or other substituted aromatic materials as well as multiple ring aromatic compounds such as naphthalene are excellent solvents for use in the process as they will usually dissolve bitumen totally. Many of these mononuclear aromatic compounds freeze at higher temperatures than water. Therefore, especially preferred solvents of this class are those with freezing points below that of water such as toluene and meta- and ortho-xylene. Economics will generally dictate that only the simpler compounds such as toluene or xylene or mixtures thereof will be used.
A mixture of aliphatic and aromatic hydrocarbons such as pentane and toluene comprise an excellent solvent for the process of this invention. Mixed aromatic solvents are frequently available from processing streams of refineries which contain a mixture of benzene, toluene, xylene and a substantial amount of paraffinic materials such as propane or butane. Such materials are economic solvents and frequently the materials are very satisfactory. This can best be determined by simple tests utilizing the solvent under consideration and a sample of the bitumen from the formation. Mixtures of any of the above described compounds may also be used as the solvent in the practice of our invention.
Carbon disulfide and chlorinated methane such as carbon tetrachloride are also suitable solvents for use in this invention.
Any hydrocarbon solvent which is gaseous at about 75° F at atmospheric pressure may also be used as the solvent in the process of our invention either alone or in combination with a liquid solvent. Low molecular weight paraffinic hydrocarbons such as methane, ethane, propane and butane as well as olephinic hydrocarbons such as ethylene, propylene or butylene may be used.
It is preferred that the solvent be at a temperature below the freezing point of the water contained in the tar sand formation, although this invention encompasses the use of solvent at temperatures above the freezing point of the water. Of course, in the practice of this embodiment only solvents which freeze at temperatures lower than the freezing point of the formation water are suitable. Toluene and meta- and ortho-xylene are examples of solvents having low freezing points. If the solvent is at a temperature below the freezing point of the water, an additional benefit may accrue. That is, as the solvent dissolves the bitumen, it will also carry ice crystals to the surface through the production well. These solid crystals of ice may be removed efficiently by filtration or other methods and a water-free solvent bitumen mixture may then be obtained. In the prior art, methods which produce bitumen and liquid water also produced a great deal of emulsion between the bitumen and the water. Such emulsions are very difficult to break and have often caused the downfall of other processes.
It is also an embodiment of this invention to use the same fluid as the fracturing fluid as is used to cool the formation and to be the solvent to recover the bitumen. The selection of the fluids for each of these functions may be up to those skilled in the art considering the particular situation involved. However, it is within the scope of this invention that these fluids may be different from each other or that any two may be the same or that they may all be the same fluid.
FIELD EXAMPLE
In order to better understand the process of this invention, the following field example is offered as an illustrative embodiment of the invention. However, it is not meant to be limitative or restrictive thereof.
A tar sand deposit is located at a depth of 450 feet and the thickness of the deposit is 70 feet. Since the ratio of overburden thickness to tar sand deposit thickness is considerably greater than 1, the deposit is not economically suitable for strip mining. It is determined that the most attractive method of producing this particular reservoir is by means of solvent flooding. It is further determined that it would be desirable to establish communication between production and injection wells by means of a fracture in the formation and then to circulate a solvent through the fracture.
As a first step, water is injected into the injection well under such pressure so as to force a fracture to develop between the injection and production wells. Once communication is established, toluene is circulated in the fracture zone between the injection and production wells. Its temperature, 0° F, is well below the freezing point of the water in the formation, and it will quite adequately render the bitumen in the formation rigid. The toluene is circulated for several days allowing the formation in the vicinity of the fracture zone to become quite rigid, due to the low temperature of the toluene. Sand is then placed in the circulating toluene to fill the fracture zone and prop it. The toluene at 0° F is continued circulating in the fracture between the injection well and the production well. The toluene being a solvent for bitumen carries dissolved bitumen to the surface along with ice crystals. These ice crystals are filtered and the bitumen and solvent are separated by distillation. The toluene may then be reinjected into the injection well and the continuous process of solvent extraction continued.
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A competent permeable communication zone connecting injection and production wells completed in a tar sand which communication zone will be rigid and will not tend to slump or heal may be developed by injecting a fluid in the injection well under such pressure so as to fracture the tar sand formation between the injection well and the production well and circulating a fluid between the injection and production wells which is at a temperature sufficiently low to freeze the water in tar sands. The fluid may contain propping agents to hold the fracture surfaces apart. This procedure will rigidify the hydrocarbon portion of the tar sand formation in the vicinity of the fracture zone as well as freeze the water in the tar sand formation. Once the fracture is established a solvent for the hydrocarbon in the tar sands may be circulated preferably at a temperature below the freezing point of the water in the tar sands to extract the bitumen therefrom.
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BACKGROUND OF THE INVENTION
The present invention relates to a method of reducing the leakage of storm waters from a storm sewer system and, more particularly, it relates to the insertion of a flexible sleeve attached to the perimeter of the storm sewer line in the catch basin at the upstream end of a given segment of storm sewer to prevent or reduce effluent water from the storm sewer from entering into the sanitary sewer system.
Water control in municipal areas is normally divided into two components: sanitary and storm. The lines which collect sanitary waste lead to a facility with special apparatus and methods for removal of those materials which would degrade the quality of the stream accepting the discharge. Storm water, except in very unusual circumstances, may be discharged into adjacent streams without any treatment. The collection systems for these two streams are frequently inadequately isolated from one another. In fact early in the twentieth century they were some times deliberately combined so that storms would flush the sanitary system, resulting in the dumping of raw sewage into streams when the capacity of the treatment plant was exceeded. This became environmentally unacceptable, especially to those immediately downstream. Such systems have now been replaced.
In addition, the drains for storm waters from the downspouts and footers of homes are frequently tied into the sanitary sewer since the sanitary sewer is normally installed lower than the storm sewer. Water from this source contributes to the overload experienced at treatment plants during rainstorms. A concerted effort has been made in most communities to eliminate this source of storm waters entering the sanitary lines. In spite of these extensive and frequently expensive efforts, unacceptable flow increases in the sanitary lines during rain storms or winter runoff is still a common occurrence. This leads to the backup of raw sewage into basements as well as sewage facility overload. Holding ponds are commonly installed to prevent overflow into nearby streams, but this does not prevent raw sewage backup. In fact such backup may occur even in new homes that are connected to an existing system. This occurs because of the general nature of construction. Sanitary sewers have been intended to be hydrostatically sound for a number of years but older installations, constructed of vitreous tile joined with a mastic, commonly leak at these joints.
At the time of installation, the tile typically was laid level and covered with crushed rock. The rock was used to avoid the subsidence which would be encountered with soil fill. Furthermore the rock provided a firm base for the street, however, this structure allows for the rapid passage of water in and around the sanitary sewer line. When a break or any deterioration of the sanitary sewer line occurs, extraneous water outside the sanitary sewer line, such as storm water, finds its way into the sanitary sewer system. Streets are normally crowned to provide drainage. This requires cross street storm connections unless two parallel lines are provided for each street. Such parallel lines are seldom used because of the costs involved. It should further be noted that the object of storm drainage is to remove the water from the streets. Any water that can soak into the ground need not be provided for by larger lines downstream. Hence, no effort was made in older installations to insure the hydraulic integrity of storm lines. The result of this combination is that leaky storm lines frequently pass over crushed rock beds which cover leaky sanitary sewers. The net result is that very large quantities of storm waters are transferred from the storm sewers to the sanitary sewers with all the problems discussed above.
The situation can be corrected by replacement of one or both lines. This, however, is very labor intensive and, because of the great increase in underground utilities, represents an ever increasingly costly approach as well. Removal of any constrictions and construction of holding ponds have also been used. This, of course does not directly address the problem. In fact, new allotments have experienced raw sewage backup because of the inflow of storm water into the sanitary line even though the line immediately in front of the house is hydrostatically sound.
U.S. Pat. Nos. 4,009,063; 4,064,211; and 4,135,958 teach the use of a hollow plastic cylinder which is folded in such a manner that it can be inserted into the existing sanitary sewer. Pressure is applied to force this liner out against the walls. Heat is applied to cure this liner in the expanded shape. Extensive use of this method requires a method of reopening tap-in junctions which are closed off by the new liner. Special machines for this purpose are disclosed in U.S. Pat. Nos. 4,685,983; 4,819,721; and 5,368,423. In addition some digging is required with all the attendant dangers of damaging underground utilities whose positions may not be accurately known. This method had been found particularly cost effective only in instances where a large number of phone, electrical, and other utility lines are known to exist.
Accordingly, there is a need for a convenient and practical means for insuring that storm water is carried away by the storm sewer without leaking into the sanitary sewer system.
SUMMARY OF THE INVENTION
In accordance with the present invention, a flexible sleeve is attached at the perimeter of the upstream end of a storm sewer line an any catch basin. The attachment is made in such a manner as to require any water flowing out of the catch basin to flow through the sleeve. The sleeve bridges any leaks in the original storm line while still using the original line to determine the destination of the flow. The flexible sleeve size is chosen so that the annular surface of the sleeve rests against the original line at maximum flow. At lesser flows the flexible liner drops away permitting inflow from any connecting line. Thus at maximum flow the sleeve prevents backflow into lines (taps) connected to the storm line. At lesser flows only the bottom of the storm line will be covered so that any water from these taps, normally a house roof or sump drain, can flow in the normal manner. Containment of the bulk of the water within the sleeve prevents flow to the rock fill above the sanitary sewer. A particular advantage of the present invention is that it can be carried out without the need for excavation or digging.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional side view of a storm sewer illustrating the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention is most conveniently carried out by use of blown film available in sleeve form, i.e., not slit, in very long lengths. Typically, the blown film is a polymeric material such as a polyolefin, e.g., polyethylene, particularly, linear low density polyethylene; plasticized polyvinylchloride; or urethane elastomer. The sleeve is turned up in such manner so that the inside 12 of the sleeve 10 will be placed against the sewer to be lined. The sleeve 10 is secured between the outer surface of a first hollow, tapered member 16 and the inner surface of a second hollow, tapered member 18. The second member 18 is wedged into the inlet end of a sewer in a manner which minimizes any tearing of the sleeve 10. The point of attachment to the sewer is normally in a catch basin. The film, so attached, inverts as water is added and the sleeve 10 is forced into the line by the water pressure. The uninverted sleeve 10 is, of course, still attached and is played out as required. Pulling on the sleeve 10 at the uninverted portion coming off the reel may serve to move past minor obstacles. When the inverting sleeve 10 emerges at the next catch basin it is held in that position to determine whether sharp glass or other objects in the sewer have damaged the liner. In the absence of such damage, the liner is cut in the downstream catch basin to complete the installation. The transfer of the water entering at the upstream catch basin to the one downstream with little or no leakage is thus assured.
The present invention does not require any particular method of installation. The only requirements are (1) that the sleeve 10 be sufficiently flexible so that it can be introduced, via a catch basin without enlargement, into the sewer 20, and (2) that the sleeve 10 be attached to the perimeter of the storm sewer 20 in such a manner that a substantial portion of the inflow on the upstream end must pass through the sleeve 10. The invention is particularly useful in sewer systems containing one or more tape lines 22.
EXAMPLE 1
Two tapered half gallon plastic containers 16 and 18, e.g. containers commonly used for sherbet, are modified as follows. The bottoms are cut out. The central portion of one of the lids is cut out leaving the outer ring 14 in tact. The end of blown polyethylene film with an expanded circumference of about six inches is inserted through the lid ring. The film is then inserted through one of the modified containers 16 from top to bottom. The film is folded back on the container 16 and held in place by snapping the lid ring 14 in place. The second modified container is placed over the first to wedge the film between the two containers 16 and 18. The latter container 18 prevents roughness of the existing sewer line from damaging the film at the point of attachment. The small end of these modified containers with the film secured between is inserted into the existing storm sewer 20 at the upstream end in a catch basin. Water is added to the catch basin. The water presses the film into the existing sewer 20. The sleeve 10 is then played out slowly as the water forces the sleeve 10 further into the sewer line. When the film appears at the downstream catch basin, the addition of water is stopped and the film is held in place at the upstream end. This situation is retained for a few minutes to determine whether the film has been torn by glass fragments in the sewer. If there is leakage the film is removed and the sewer cleaned in the normal manner and the process repeated. When the film shows no sign of installation damage, it is cut off at the downstream end and the unexpanded portion pulled out at the upstream end. The installation is now complete.
EXAMPLE 2
A tether ball is attached to a light rope long enough to extend through the sewer to be lined. The ball is forced through the sewer by a stream of water. The liner film is attached to the line and pulled through the length of the sewer to be lined. The upstream end of the film is folded over the protruding end of the existing sewer and clamped in place with a large hose clamp. The integrity of the system may be tested by adding water at the upstream catch basin and determining whether any escapes downstream. When it has been determined that the film was not torn during installation, the line is removed from the downstream end and the installation is complete.
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A method for reducing leakage of effluent water from a storm sewer system, the method comprising securing a flexible, water-impermeable sleeve to the inlet end of a storm sewer line, extending the sleeve through the interior of storm sewer line, and severing the sleeve at the discharge end of the storm sewer line, wherein the sleeve forms a liner for the storm sewer line.
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This application is a continuation of applicant's patent application Ser. No. 415,575 filed Sept. 7, 1982, now abandoned.
This invention relates to new and useful improvements in a massage device for massaging the scalp.
BACKGROUND OF THE INVENTION
As is well known, the use of hand massaging of the scalp has been used to stimulate blood circulation which promotes scalp health and also has a relaxing effect. Additionally, such massaging has been found to stimulate hair growth. The usual hand massage is accomplished by placing the fingers of the hands on each side of the top of the head with the thumb of each hand engaging the side of the head just above one ear. Keeping the thumb of each hand relatively stationary, the fingers of each hand are moved toward and away from each other to cause the outer skin layer of the head to move relative to the skull. At the same time, the outer skin layer on the right side of the head is alternately moved back and forth with respect to that portion of said outer skin layer on the opposite or left side of the head. This type of massage has been found most effective in stimulating circulation in the scalp which promotes scalp health and relaxation as well as stimulating hair growth.
Many types of scalp treatment devices have been patented but none have been particularly successful with the possible exception of the hand vibrator which depends not on the vibrator but upon the hand of the person using such vibrator. Actually, a vibrator merely causes a vibration of relative small motion, so that it applies its vibratory action only to a very limited or localized area. It is impossible to impart any substantial movement of the outer skin layer with respect to the skull as is done with a hand massage. There are many types of vibrators in the prior art and examples of such types are shown in the patents to Merrill U.S. Pat. No. 1,974,031, Schamblin U.S. Pat. No. 3,481,326, Wojtowicz U.S. Pat. No. 3,720,204 and Okazaki et al U.S. Pat. No. 4,210,134. The patent to Schopfel U.S. Pat. No. 3,457,913 illustrates a scalp vibrator which applies vibration to various areas of the scalp but it makes no attempt to impart a lateral motion to large areas of the outer skin layer so as to move such large areas toward and away from each other relative to the skull and in a motion which duplicates the hand massage.
Other prior patents of some general interest are Avery U.S. Pat. No. 2,569,795, Heger U.S. Pat. No. 2,655,145, Avery U.S. Pat. No. 2,657,684 and Pitzen et al U.S. Pat. No. 3,872,850. However, none of these devices attempt to impart the "hand massage" motion to the outer skin layer of the scalp.
OBJECTS OF THE INVENTION
It is one object of this invention to provide an improved massage device for massaging the scalp having massage elements engaging the sides and top of the scalp in such a manner that when actuated, said elements move portions of the outer skin layer of the scalp relative to the skull to substantially duplicate a "hand massage".
Another object is to provide a hat-like body adapted to be supported upon the head and having a pair of massage elements formed to engage the head and mounted to move toward and away from each other to impart movement to relatively large areas of the outer skin layer of the scalp with respect to each other and to the skull of the head.
A further object is to control the motion of the massage elements by means of a cam and pin arrangement whereby the travel or path of said massage elements may be accurately defined with respect to the head of the person whose scalp is being massaged.
Another object is to provide improved massage elements constructed of a resilient material with each element having its inner surface contoured to conform to approximately one-half of the top, side and rear portions of the head thereby giving it a generally semi-circular or oval shape in cross-section. Each element also has an inner surface capable of frictionally engaging the scalp to assure movement of the outer skin layer of the scalp relative to the skull when the massage device is operating.
A particular object is to provide an improved clamping means within the hat-like body of the device for firmly mounting said body on the head of the person being treated.
Other objects and advantages of the present invention are hereinafter set forth and are explained in detail with reference to the drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a massaging device, constructed in accordance with the invention, and illustrating the same mounted upon the head of a user;
FIG. 2 is a front elevation of the device;
FIG. 3 is a vertical cross-sectional view taken through the approximate center and along the line 3--3 of FIG. 1 with the massaging elements in their inward position;
FIG. 4 is a view similar to FIG. 3 but showing the massaging elements in their laterally separated or outward position;
FIG. 5 is a vertical sectional view taken on the line 5--5 of FIG. 4;
FIG. 6 is a horizontal cross-sectional view taken on the line 6--6 of FIG. 5;
FIG. 7 is a partial cross-sectional view taken on the line 7--7 of FIG. 3;
FIG. 8 is an isometric view of the cam which imparts a reciprocating action to the massage elements;
FIG. 9 is an exploded view showing the support plate and one of the massage elements which are mounted to reciprocate on said plate;
FIG. 10 is an exploded view of one of the clamping cushions and its base member; and
FIG. 11 is an enlarged sectional view showing the manner of adjusting the clamping cushions with respect to the head of the user.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings, the numeral 10 designates an outer housing which is shaped similarly to a hat or helmet so that it may fit the head of the user. The housing is constructed of plastic or other suitable material and has a recess 11 in its forward wall (FIG. 2) which facilitates placement of the housing upon the head. At the lower end of each side wall of the housing, an adjustable clamping cushion 12 is mounted so that when the housing is in place on the head, the cushions 12 engage the sides of the head just above the ears and maintain the housing in position. A pair of massaging elements 13 are mounted within the housing and are adapted to engage the crown and the sides of the head when the housing is in place. The massaging elements are movable by means of a suitable motor 14 which drives a cam assembly 15 to operate the massaging elements 13 in a desired manner. The upper end of the housing 10 is preferably open as indicated at 10a.
The massage elements 13 are an important feature of the present invention and are best shown in FIGS. 3, 4 and 5. Each element is constructed of a resilient or flexible material such as rubber and has an inner surface 16 which is generally contoured to fit approximately one-half of the top, side and rear portions of the head. The curvature of said inner surface is such that it engages the crown, sides and back portions of the head. The material has sufficient resilience or flexibility to assure a firm frictional contact with the head. Although not essential, it is desirable that this inner surface be provided with inwardly extending projections 17 which are also formed of a resilient or flexible material. When the elements 13 are in contact with the head of the user, the flexible projections 17 engage the outer layer of skin of the scalp with a relatively firm frictional contact. Thus, upon the massaging elements 13 being moved in the manner hereinafter described, the scalp will be massaged in a particular way which substantially duplicates the hand massage which is normally given to the scalp when a massager uses his hands in a treatment.
For imparting the desired type of motion to the massage elements, each element is molded or otherwise secured to a slide plate 18 (FIGS. 5 and 9). The plate 18 is formed with parallel offset flanges 19 on each side thereof and such flanges are adapted to slide within retaining tracks 20 formed on the lower end of a support plate 21. The support plate 21 extends across the interior of the housing 10 and is secured to vertical posts 22 which are molded or otherwise secured to the inner surface of said housing. Suitable screws 23 pass upwardly through openings 24 formed in the support plate and thread into the support posts 22. The support posts are clearly shown in FIG. 4 and are partially shown in FIG. 5 with the screws 23 being indicated in dotted lines. With the support plate 21 secured in place extending across the interior of the housing, its depending retaining tracks 20 are engaged by the flanges 19 of each massage element 13 whereby each element may move laterally within the interior of the housing.
The cam assembly 15 imparts the desired movements to the two massage elements 13. For driving the slide plate of each element, each plate has an upstanding drive pin 25 (FIG. 9). The pins 25 of the two slide plates extend through elongate slots 26 formed in the support plate and may move longitudinally within said slots. The upper end of each drive pin 25 engages within a groove 27 formed in the drive cam 28 of the cam assembly 15 which is driven through shaft 29 by the motor 14. As clearly shown in FIGS. 6 and 8, the drive cam is a relatively long oval shape and the groove 27 within which drive pins 25 are engaged is of substantially the same oval shape. By reason of the shape of the cam, the massage elements 13 will be reciprocated laterally from the position shown in FIG. 3 to the position shown in FIG. 4. As shown in the drawings, the points of attachment where the massage elements 13 are moveably mounted with respect to the housing 10 move toward and away from each other in the same plane and along a straight line. With the elements engaged with the scalp, this lateral reciprocating motion will result in the top layers of the scalp being squeezed toward each other and then released in a back and forth motion. The speed of the motor is adjusted so that this reciprocating motion will substantially duplicate the actions of the fingers upon the scalp when a hand massage is being performed.
The motor 14 is suitably secured to upstanding posts 30 which are formed on the support plate 21 so that the motor and its associated cam assembly are carried by the single support plate which extends transversely across the interior of the housing. It might also be noted that the massage elements 13 are carried by the same support plate by reason of the flanges 19 having a sliding engagement with the retaining tracks 20 which depend from the support plate.
When the device is to be mounted on the users head, it is placed in position with the arcuate clamping cushions 12 having a snug engagement with the side of the head just above the ears. In order to permit an adjustment of each arcuate cushion, said cushion is disposed within a support or base member 31 (FIGS. 3, 4 and 10). Each base member has its ends recessed at 31a and within said recess an upwardly facing toothed or irregular surface 32 is formed. As more clearly shown in FIG. 11, the irregular toothed surface 32 is arranged to engage a downwardly facing complementary irregular surface 33 formed on the lower end of an enlarged portion 34 extending inwardly from the inner surface of the housing 10. By observing FIG. 11, it will be evident that the position of the support member 31 and the clamping cushion 12 which is carried thereby may be adjusted inwardly and outwardly with respect to the head. A suitable screw 35 threads into the lower surface of the enlarged portion 34 to maintain an adjusted position of the cushion.
In the use of the device, the housing is placed upon the head in the manner shown in FIGS. 1 and 2 with the massage elements 13 having their inner surfaces 16 in firm engagement with the scalp. The projections 17 are relatively small and close together and form flexible gripping means for firmly engaging the outer layer of skin of the scalp. With the housing and its elements 13 in proper position with respect to the scalp, the side clamping cushions 12 are properly adjusted to maintain the device in proper position.
Upon operating the motor, the massage elements 13 will, by reason of the cam assembly 15, move in a lateral reciprocating motion. Such elements will move from the position of FIG. 3 to a spaced position as shown in FIG. 4. The gripping members 17 of the elements will, during movement of said elements, cause a movement of the outer skin layer of the scalp in a back and forth motion relative to the skull. There is substantially no vibration in the sense of the usual vibrator which has been used for massage purposes in the past but only a reciprocating movement of the massage elements toward and away from each other in a general horizontal plane with respect to the head.
As has been noted, it is desirable to form the inner surfaces of the massage elements in what could be termed a portion of an oval so as to properly engage the head. When the elements 13 are in the position of FIG. 3, the outer layers of the skin of the scalp should be somewhat squeezed toward the center or crown of the head. As the elements move away from each other to the position of FIG. 4, there is a stretching action imparted to the skin layers and by adjusting the speed of the motor, it is possible to substantially duplicate the hand action which is applied to the scalp by a hand massage. It has been found that the reciprocating action or the lateral back and forth movement is very effective in providing a massage of the head which not only stimulates blood circulation in the scalp but also encourages hair growth.
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A massaging device for the scalp includes a pair of massaging elements which frictionally engage the scalp and are reciprocated with respect to each other in a generally horizontal direction with respect to the head resulting in moving relatively large areas of the outer skin layer of the scalp with respect to the skull and also with respect to each other and thereby substantially duplicate the massaging action obtained with the usual hand massage to improve circulation in the scalp accomplish relaxation and stimulate hair growth.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority based upon provisional application Ser. Nos. 60/540,263 and 60/540,264, both filed Jan. 28, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a capacitor and, more particularly, to at least two side-by-side capacitors connected in series. This is done using various interconnect structures connecting between the negative polarity pin/casing of one capacitor to the positive polarity lead of another. The present interconnects are of a relatively low profile having a conductive member insulted from the capacitor casings and to which the positive pin and negative lead are welded. A polymeric material disposed there between otherwise insulates the side-by-side capacitors from each other.
[0004] 2. Prior Art
[0005] FIGS. 1 to 4 show a conventional design for a series connected capacitor assembly 10 comprising a first capacitor 12 and a side-by-side second capacitor 14 . The first capacitor 12 comprises an anode of an anode active material 16 and a cathode of a cathode active material 18 ( FIG. 4 ) housed inside a hermetically sealed casing 20 . The capacitor electrodes are operatively associated with each other by an electrolyte (not shown) contained inside the casing, as will be described in detail hereinafter. It should be pointed out that the capacitors 12 , 14 can be of either an electrochemical type wherein both the anode and the cathode electrodes are provided by conductive substrates having a capacitive material contacted thereto, or an electrolyte type wherein the cathode electrode is provided by a conductive substrate having capacitive properties. The illustrated capacitors are preferably of the latter type, however, that should not be construed as limiting.
[0006] As particularly shown in FIGS. 2 and 3 , casing 20 is of a metal material comprising mating first and second clamshells or mating casing portions 22 and 24 . Casing portion 22 comprises a surrounding sidewall 26 extending to a face wall 28 . Similarly, casing portion 24 comprises a surrounding sidewall 30 extending to a face wall 32 . The sidewall 26 of the first casing portion 22 is sized to fit inside the periphery of the second sidewall 30 in a closely spaced relationship. This means that the first face wall 28 is somewhat smaller in planar area than the second face wall 32 of casing portion 24 . Also, the height of the second surrounding sidewall 30 of casing portion 24 is less than the height of the first surrounding sidewall 26 . The surrounding sidewall 26 has an inwardly angled lead-in portion 34 that facilitates mating the casing portions 22 , 24 to each other.
[0007] With the first and second casing portions 22 , 24 mated to each other, the distal end of the second surrounding sidewall 30 contacts the first surrounding sidewall 26 a short distance toward the face 28 from the bend forming the lead-in portion 34 . The casing portions 22 , 24 are hermetically sealed to each other by welding the sidewalls 26 , 30 together at this contact location. The weld is provided by any conventional means; however, a preferred method is by laser welding.
[0008] The anode active material 16 is typically of a metal selected from the group consisting of tantalum, aluminum, titanium, niobium, zirconium, hafnium, tungsten, molybdenum, vanadium, silicon, germanium, and mixtures thereof in the form of a pellet. As is well known by those skilled in the art, the anode metal in powdered form, for example tantalum powder, is compressed into a pellet having an anode wire 36 embedded therein and extending there from, and sintered under a vacuum at high temperatures. The porous body is then anodized in a suitable electrolyte to fill its pores with the electrolyte and form a continuous dielectric oxide film on the sintered body. The assembly is then reformed to a desired voltage to produce an oxide layer over the sintered body and anode wire. The anode can also be of an etched aluminum or titanium foil.
[0009] The cathode electrode is spaced from the anode electrode housed inside the casing and comprises the cathode active material 18 . The cathode active material has a thickness of about a few hundred Angstroms to about 0.1 millimeters directly coated on the inner surface of the face walls 28 , 32 (FIGS. 2 to 4 ) or, it is coated on a conductive substrate (not shown) in electrical contact with the inner surface of the face walls. In that respect, the face walls 28 , 32 may be of an anodized-etched conductive material, have a sintered active material with or without oxide contacted thereto, contacted with a double layer capacitive material, for example a finely divided carbonaceous material such as graphite or carbon or platinum black, a redox, pseudocapacitive or an under potential material, or be an electroactive conducting polymer such as polyaniline, polypyrol, polythiophene, and polyacetylene, and mixtures thereof.
[0010] The redox or cathode active material 18 includes an oxide of a first metal, a nitride of the first metal, a carbonnitride of the first metal, and/or a carbide of the first metal, the oxide, nitride, carbonnitride and carbide of the first metal having pseudocapacitive properties. The first metal is preferably selected from the group consisting of ruthenium, cobalt, manganese, molybdenum, tungsten, tantalum, iron, niobium, iridium, titanium, zirconium, hafnium, rhodium, vanadium, osmium, palladium, platinum, nickel, and lead, an oxide of the former being preferred.
[0011] The cathode active material 18 may also include a second or more metals. The second metal is in the form of an oxide, a nitride, a carbonnitride or carbide, and is not essential to the proper functioning of the capacitor electrode. The second metal is different than the first metal and is selected from one or more of the group consisting of tantalum, titanium, nickel, iridium, platinum, palladium, gold, silver, cobalt, molybdenum, ruthenium, manganese, tungsten, iron, zirconium, hafnium, rhodium, vanadium, osmium, and niobium.
[0012] The mating casing portions 22 , 24 , and the electrically connected conductive substrate if it is provided, are preferably selected from the group consisting of tantalum, titanium, nickel, molybdenum, niobium, cobalt, stainless steel, tungsten, platinum, palladium, gold, silver, copper, chromium, vanadium, aluminum, zirconium, hafnium, zinc, iron, and mixtures and alloys thereof. Preferably, the face and sidewalls of the casing portions have a thickness of about 0.001 to about 2 millimeters.
[0013] The exemplary electrolytic type capacitor shown in FIGS. 1 to 4 has the cathode active material 18 preferably coating the face walls 28 , 32 spaced from the respective sidewalls 26 , 30 . Such a coating is accomplished by providing the conductive face walls 28 , 32 with a masking material in a known manner so that only an intended area of the face walls is contacted with active material. The masking material is removed from the face walls prior to capacitor fabrication. Preferably, the cathode active material 18 is substantially aligned in a face-to-face relationship with the major faces of the anode active material 16 . A preferred coating process is in the form of an ultrasonically generated aerosol as described in U.S. Pat. Nos. 5,894,403; 5,920,455; 6,224,985; and 6,468,605, all to Shah et al. These patents are assigned to the assignee of the present invention and incorporated herein by reference.
[0014] A separator (not shown) of electrically insulative material is provided between the anode active material 16 and the cathode active material 18 to prevent an internal electrical short circuit between them. The separator material also is chemically unreactive with the anode and cathode active materials and both chemically unreactive with and insoluble in the electrolyte. In addition, the separator material has a degree of porosity sufficient to allow flow therethrough of the electrolyte during the electrochemical reaction of the capacitor 12 . Illustrative separator materials include woven and non-woven fabrics of polyolefinic fibers including polypropylene and polyethylene or fluoropolymeric fibers including polyvinylidene fluoride, polyethylenetetrafluoroethylene, and polyethylenechlorotrifluoroethylene laminated or superposed with a polyolefinic or fluoropolymeric microporous film, non-woven glass, glass fiber materials and ceramic materials. Suitable microporous films include a polyethylene membrane commercially available under the designation SOLUPOR® (DMS Solutech), a polytetrafluoroethylene membrane commercially available under the designation ZITEX® (Chemplast Inc.), a polypropylene membrane commercially available under the designation CELGARD® (Celanese Plastic Company, Inc.), and a membrane commercially available under the designation DEXIGLAS® (C. H. Dexter, Div., Dexter Corp.). Cellulose based separators typically used in capacitors are also contemplated. Depending on the electrolyte used, the separator can be treated to improve its wettability, as is well known by those skilled in the art.
[0015] A suitable electrolyte for the capacitors 12 , 14 is described in U.S. Pat. No. 6,219,222 to Shah et al., which includes a mixed solvent of water and ethylene glycol having an ammonium salt dissolved therein. Other electrolytes for the present capacitors are described in U.S. Pat. No. 6,687,117 to Liu et al. and U.S. Pub. No. 2003/0090857. The electrolyte of the former patent comprises de-ionized water, an organic solvent, isobutyric acid and a concentrated ammonium salt while the latter publication relates to an electrolyte having water, a water-soluble inorganic or organic acid or salt, and a water-soluble nitro-aromatic compound. These patents and publication are assigned to the assignee of the present invention and incorporated herein by reference. The electrolyte is provided inside the hermetically sealed casing through a fill opening closed by a hermetic closure 38 ( FIG. 1 ), as is well known by those skilled in the art.
[0016] The casing 20 , including the portions 22 , 24 , being of a conductive metal serves as one terminal for making electrical connection between the capacitor and its load. A pin 40 ( FIG. 2 ) is welded to the sidewall 26 to provide the negative terminal for the first capacitor 12 . Pin 40 also provides the negative terminal for the side-by-side capacitor assembly 10 , as will be described in detail hereinafter. The other electrical terminal or contact for the first capacitor 12 comprises the anode wire 36 extending from the anode active material 16 and connected to the anode lead 42 extending through the first surrounding sidewall 26 .
[0017] As shown in FIGS. 2 and 3 , the anode lead 42 is electrically insulated from the metal casing 20 by an insulator glass-to-metal feedthrough 46 . The glass-to-metal feedthrough 46 comprises a ferrule 48 defining an internal cylindrical through bore or passage 50 of constant inside diameter. Outwardly facing annular steps 52 A and 52 B are provided at the respective upper and lower ferrule ends. The upper step 52 A is of an outer diameter sized to fit in a closely spaced relationship in an annular opening 54 in the first casing sidewall 26 with the remaining body of the ferrule butted against the inner surface of the sidewall. The ferrule 48 is secured therein by welding, and the like.
[0018] As shown in FIG. 2 , the anode active material 16 has a notch 56 that provides clearance for the glass-to-metal feedthrough 46 . The anode wire 36 embedded in the anode active material 16 extends outwardly from the notch 56 . A distal end 36 A is bent into a position generally parallel to the longitudinal axis of ferrule 48 . A proximal end 42 A of the anode lead 42 is bent into a J-hook shape to align parallel with the distal end 36 A of the anode wire 36 . The distal end 36 A of the anode wire is then welded to the proximal end 42 A of the anode lead to electrically connect the anode to the lead 42 .
[0019] An insulative glass 58 provides a hermetic seal between the inside of the ferrule 48 and the anode lead 42 . The glass is, for example, ELAN® type 88 or MANSOL™ type 88 . The anode lead 42 preferably comprises the same material as the anode active material 16 . In that manner, the portion of the anode lead 42 extending outside the capacitor 12 for connection to a load is hermetically sealed from the interior of the capacitor and insulated from the mating casing portions 22 , 24 serving as the terminal for the cathode.
[0020] The second capacitor 14 illustrated in drawing FIGS. 1 to 4 is similar to the first capacitor 12 in terms of its physical structure as well as its chemistry. As previously discussed, however, the capacitors 12 , 14 need not be chemically similar. For example, the first capacitor 12 can be of an electrolytic type while the second capacitor 14 can be of the electrochemical type. Preferably, the capacitors 12 , 14 are both of the electrolytic type.
[0021] The second capacitor 14 comprises an anode active material 60 and a cathode active material 62 ( FIG. 3 ) housed inside a hermetically sealed casing 64 and operatively associated with each other by an electrolyte (not shown). Casing 64 is similar to casing 20 of capacitor 12 and comprises mating third and fourth portions 66 and 68 ( FIG. 1 ). Casing portion 66 comprises a surrounding sidewall 70 extending to a face wall 72 . Similarly, casing portion 68 comprises a surrounding sidewall 74 extending to a face wall 76 . The sidewall 70 of the third casing portion 66 is sized to fit inside the periphery of the fourth sidewall 74 in a closely spaced relationship. The height of the fourth surrounding sidewall 74 is less than that of the third surrounding sidewall 70 and its inwardly angled lead-in portion 78 . Laser welding the contacting sidewalls 70 , 74 together hermetically seals the third and fourth mated casing portions 66 , 68 to each other.
[0022] The cathode active material 62 is supported on the inner surfaces of the face walls 72 , 76 opposite the major faces of the anode active material 60 . In that manner, the casing 64 , being of a conductive metal, serves as one terminal for making electrical connection between the capacitor 14 and its load.
[0023] The other electrical terminal or contact is provided by a conductor or lead 80 extending from within the capacitor 14 connected to the anode active material 60 and through the third surrounding sidewall 70 . The anode active material 60 is similar in construction to the anode of capacitor 12 and includes a notch that provides clearance for a glass-to-metal feedthrough 82 . An anode wire 84 embedded in the anode active material 60 extends outwardly from the notch to a distal end welded to the proximal end of the anode lead 80 to electrically connect the anode to the lead.
[0024] The glass-to-metal feedthrough 82 electrically insulates the anode lead 80 from the metal casing 64 and comprises a ferrule 86 provided with an annular step of reduced diameter fitted in a closely spaced relationship in an annular opening in the first casing sidewall 70 . The remaining ferrule body is butted against the inner surface of the sidewall with the ferrule 86 being secured therein by welding. An insulative glass 88 hermetically seals between the cylindrical inner surface of the ferrule 86 and the anode lead 80 .
[0025] A separator (not shown) of electrically insulative and ionically conductive material segregates the anode active material 60 from the cathode active material 62 . The electrolyte is provided inside the hermetically sealed casing 64 through a fill opening closed by a hermetic closure 90 .
[0026] The thusly constructed first and second capacitors 12 , 14 are then positioned back-to-back or side-by-side. In this configuration, the face wall 32 of the casing portion 24 of the first capacitor 12 is aligned with and proximate to the face wall 76 of the casing portion 68 of the second capacitor 14 . An adhesive 94 ( FIG. 3 ), for example, a double-sided polyimide tape, secures the capacitors 12 , 14 together without the respective casing portions 24 , 68 being electrically shorted to each other. A suitable tape for this purpose is commercially available from E. I. Du Pont De Nemours and Company Corporation under the trademark KAPTON®. If desired, the capacitors 12 , 14 are provided with a paralyene coating by a vacuum deposition process about their entire outer surface prior to being aligned in the side-by-side orientation.
[0027] The capacitors 12 , 14 are then electrically connected in series. The prior art design used with the capacitors 12 , 14 comprises a connecting tab 96 having a foot portion 96 A secured to the surrounding sidewall 70 of casing portion 68 , such as by welding, adjacent to the anode lead 42 for the first capacitor 12 . An arm portion 96 B of the tab is butted to the distal end of the anode lead 42 . A weld (not shown) then finishes the connection of the tab 96 to the anode lead 42 . This results in the positive polarity anode lead 42 of the first capacitor 12 being connected to the negative polarity casing 64 of the second capacitor 14 . The series connected side-by-side capacitors 12 , 14 are then connectable to a load (not shown). Connecting the negative polarity terminal pin 40 of the first capacitor 12 and the polarity terminal lead 80 of the second capacitor 14 does this.
[0028] While the prior art design works well, there are improvements that can be made to it. For one, the connection between the anode lead 42 and tab 96 is a “blind” butt weld that demonstrates very poor manufacturing yields. The lead 42 under the tab 96 is typically about 0.0013 to 0.0014 inches in diameter. The spot size for the laser welder is about 0.018 inches in diameter. This means that the laser needs to be aligned perfectly with the lead 42 to effect a robust connection. If not, the laser will blow through the tab 96 , creating scrap. Welding the foot portion 96 A of the tab 96 to the sidewall 70 of casing portion 68 and the arm portion 96 B to the lead 42 are relatively slow processes that utilize expensive tooling to position the tab and then bend it into contact with the sleeve. Finally, the tab 96 can create a sharp edge and the butt-welded tab 96 and lead 42 interconnect takes up a relatively large amount of real estate in both the vertical direction off of the capacitors 12 , 14 as well as laterally on the capacitor. The prior art connecting tab 96 and anode lead 42 design is the subject of U.S. Patent Application Pub. No. 2004/0120099. This application is assigned to the assignee of the present invention and incorporated herein by reference.
SUMMARY OF THE INVENTION
[0029] The current trend in medicine is to make cardiac defibrillators, and other implantable medical devices such as cardiac pacemakers, neurostimulators, and drug pumps, as small and lightweight as possible without compromising power. This, in turn, means that capacitors contained in these devices must be readily adaptable in how they are connected to each other as well as to the battery and the device circuitry. In that light, the present invention relates to structures for serially connecting at least two capacitors together to provide the device manufacture with broad flexibility in terms of both how many capacitors are incorporated in the device and what configuration the capacitor assembly will assume.
[0030] These and other aspects of the present invention will become more apparent to those skilled in the art by reference to the following description and to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a perspective view looking at the right edges of two side-by-side capacitors 12 , 14 connected in series according to the prior art.
[0032] FIG. 2 is a cross-sectional view taken along line 2 - 2 of FIG. 1 .
[0033] FIG. 3 is an enlarged view of the indicated area of FIG. 2 .
[0034] FIG. 4 is a cross-sectional view taken along line 4 - 4 of FIG. 2 .
[0035] FIG. 5 is a perspective view of the side-by-side capacitors 12 , 14 of FIGS. 1 to 4 connected in series with an interconnect 100 according to the present invention.
[0036] FIG. 6 is an exploded view of the interconnect 100 shown in FIG. 5 including a platform 102 and a conductive bar 114 .
[0037] FIG. 7 is a perspective view of the assembled interconnect 100 shown in FIG. 6 .
[0038] FIG. 8 is a cross-sectional view along line 8 - 8 of FIG. 7 .
[0039] FIG. 9 is a partial perspective view of the interconnect 100 being moved onto the respective terminals 42 and 128 for the capacitors 12 , 14 .
[0040] FIG. 10 is a partial perspective view of the interconnect 100 connecting the capacitors 12 , 14 in FIG. 9 in series.
[0041] FIG. 11 is a partial cross-sectional view along line 11 - 11 of FIG. 10 .
[0042] FIG. 12 is an exploded view of another embodiment of an interconnect 150 including a platform 152 and a conductive bar 114 .
[0043] FIG. 13 is a perspective view of the assembled interconnect 150 shown in FIG. 12 .
[0044] FIG. 14 is a partial cross-sectional view of the interconnect 150 connecting capacitors 12 , 14 in series.
[0045] FIG. 15 is a cross-sectional view showing two of the interconnects 150 connecting three capacitors 12 , 14 and 170 in series.
[0046] FIG. 16 is an exploded view of another embodiment of an interconnect 200 including a platform 202 and a conductive bar 220 .
[0047] FIG. 17 is a bottom perspective view of the platform 202 for the interconnect 200 shown in FIG. 16 .
[0048] FIG. 18 is a partial perspective view of the interconnect 200 connecting the capacitors 12 , 14 in series.
[0049] FIG. 18A is a perspective view of a modified platform 202 A provided with a cutout 214 A.
[0050] FIG. 18B is a perspective view of the conductive bar 220 nested in the platform 202 A shown in FIG. 18A to expose a edge 220 A of the bar for wire bond connection to the series capacitors 12 , 14 .
[0051] FIG. 19 is a bottom perspective view of another embodiment of an interconnect 250 .
[0052] FIG. 20 is a partial perspective view of the interconnect 250 being moved onto the respective terminals 42 and 128 for the capacitors 12 , 14 .
[0053] FIG. 21 is a partial top plan view showing the interconnect 250 of FIGS. 19 and 20 being deformed into locking contact with the terminals 42 and 128 .
[0054] FIG. 22 is a cross-sectional view along lines 22 - 22 of FIG. 21 .
[0055] FIG. 23 is a partial perspective view of another embodiment of an interconnect 300 being moved onto the terminals 42 and 128 for the capacitors 12 , 14 .
[0056] FIG. 24 is a partial perspective view of the interconnect 300 of FIG. 22 being welded to the terminals 42 and 128 .
[0057] FIG. 25 is a partial cross-sectional view along lines 25 - 25 of FIG. 24 .
[0058] FIG. 26 is a partial perspective view of another embodiment of an interconnect 350 showing distal portions 42 A and 128 A of the respective lead and conductive pin provided in a side-by-side lap joint relationship and being welded together to connect the capacitors 12 , 14 in series.
[0059] FIG. 27 is a partial perspective view of another embodiment of an interconnect 400 for connecting capacitors 12 , 14 in series.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0060] FIGS. 5 to 11 illustrate a first embodiment of a capacitor interconnect 100 according to the present invention. This interconnect is an improvement over the tab 96 and lead 42 interconnect structure described in FIGS. 1 to 4 . In all other respects, the capacitors 12 , 14 of this and the other present invention embodiments are the same as those described with respect to the prior art, and like structural features and designs will be given the same numerical designations.
[0061] The capacitor interconnect 100 comprises a platform 102 of an insulative thermoplastic or ceramic material having a generally oval sidewall 104 extending between an upper surface 106 and a lower surface 108 . The sidewall 104 forms a pair of spaced apart rails 110 and 112 having respective upper surfaces 110 A and 112 A spaced above the upper surface 106 of the platform 102 .
[0062] A rectangular-shaped bar 114 of a conductive material, such as of tantalum, titanium, nickel, molybdenum, niobium, cobalt, stainless steel, tungsten, platinum, palladium, gold, silver, copper, chromium, vanadium, aluminum, zirconium, hafnium, zinc, iron, and alloys thereof, comprises spaced apart right and left sidewalls 114 A and 114 B extending to front and back end walls 114 C and 114 D. These sidewalls and end walls extend to and meet with an upper surface 116 and a lower surface 118 .
[0063] It is further within the scope of the invention that the conductive bar 114 can be made of any one of these materials, and alloys thereof, and then be provided with a coating on its upper surface of another one of them. This makes the conductive bar useful as a bonding pad for connection to a medical device. For example, the bar can be of nickel, aluminum, or platinum and be plated or coated with gold as a bonding pad or surface for connection to a medical device. Suitable wire bonding techniques useful with the conductive bar 114 include thermocompression ball bonding, thermosonic compressive wire bonding, ultrasonic compressive wedge bonding, thermocompression wedge bonding, stitch bonding, and tape automated bonding, among others. For more description regarding wire bonding a medical device to a conductive pad, reference is made to U.S. Pat. No. 6,626,680 to Ciurzynski et al., which is assigned to the assignee of the present invention and incorporated herein by reference.
[0064] The conductive bar 114 is provided with spaced apart openings 120 and 122 that extend through the thickness from the upper surface 116 to the lower surface 118 thereof. The platform 102 is also provided with a pair of spaced apart openings 124 and 126 that extend through the thickness from the upper surface 106 to the lower surface 108 thereof. As particularly shown in FIG. 8 , a lower portion of the openings 124 , 126 is beveled with a frusto-conical shape extending downwardly and outwardly toward the lower platform surface 108 .
[0065] As shown in FIGS. 6 to 8 , the capacitor interconnect 100 is formed by nesting the conductive bar 114 inside the rails 100 and 112 of the insulative platform 102 . In this position, the lower surface 118 of the bar 114 rests on the upper surface 106 of the platform 102 and the upper surfaces 110 A and 112 A of the rails are coplanar with the upper surface 116 of the conductive bar 114 . The right and left bar sidewalls 114 A, 114 B are in a closely spaced relationship with the respective rails 110 , 112 . The front and back end walls 114 C, 114 D of the conductive bar 114 are aligned with the opposed ends of the rails 110 , 112 . This leaves minor portions 102 A and 102 B at each end of the platform 102 uncovered by the bar.
[0066] As shown in FIG. 9 , the connection between the capacitors 12 , 14 is made by first securing a pin 128 to the surrounding sidewall 70 of the casing portion 68 for capacitor 14 . In order to provide a robust connection, a flat piece of metal serving as a foot 130 is first secured to one end of the pin 128 and this assembly is then secured to the sidewall 70 , such as by welding. Pin 128 now serves as the negative polarity connection for the second capacitor 14 . As previously described with respect to FIGS. 1 to 4 , the anode lead 42 is the positive polarity termination for the first capacitor 12 .
[0067] In order to effect a series connection between the positive polarity lead 42 and the negative polarity pin 128 of the side-by-side capacitors 12 , 14 , the insulative platform 102 supporting the conductive bar 114 is moved into the position shown in FIGS. 9 and 10 . In that manner, the positive polarity anode lead 42 is received in the aligned openings 124 and 120 and the negative polarity pin 128 is received in the aligned openings 126 and 122 in the respective platform 102 and conductive bar 114 . The beveled mouth to the platform openings 124 , 126 helps with this positioning. The upper end of the lead 42 and pin 128 now extend above the upper surface 116 of the conductive bar 114 . A laser (not shown) is used to sever the excess extending material from the lead and pin and to weld them to the conductive bar in a secure electrical connection, as shown in FIG. 11 .
[0068] In this position, the lower surface 108 of the insulative platform 102 rests on the surrounding sidewalls 30 , 74 of the casing portions 24 and 68 of the respective first and second capacitors 12 , 14 . The platform 102 also rests on the foot 130 of the negative polarity pin 128 at the bevel of opening 126 . The capacitors, which have their respective casings electrically insulated from each other by the intermediate double-sided adhesive 94 , are now serially connected to each other by the conductive bar 114 of the interconnect 100 extending from the positive polarity lead 42 of capacitor 12 to the negative polarity pin 128 of capacitor 14 .
[0069] In order to make electrical connection to the series connected capacitors 12 , 14 , a footpad 132 secured to one end of a terminal lead 134 is secured to the casing of capacitor 14 . A positive polarity pin (not shown) extends from the opposite end of the capacitor 12 electrically insulated there from by a glass-to-metal feedthrough. The series connected capacitors 12 , 14 are now connectable to a load through the lead 134 and positive polarity pin.
[0070] The capacitor interconnect 100 provides many advantages over the previously described connecting tab 96 and anode lead 42 structure. Among them is that the welds of the lead 42 and pin 128 to the conductive bar 114 are easier to make, but are more robust with improved mechanical pull strength. This is without sharp edges and while occupying significantly less real estate.
[0071] FIGS. 12 to 14 illustrate another embodiment of a capacitor interconnect 150 according to the present invention. This interconnect is similar to that of the first embodiment previously described with respect to FIGS. 5 to 11 . However, the insulative platform 152 is provided with a lower surface having a recess 154 centered between the openings 156 , 158 . The recess extends laterally from straight sidewall portion 160 to straight sidewall portion 162 and is sized to receive and fit over the surrounding sidewalls 30 , 74 of the casing portions 24 , 68 of the respective capacitors 12 , 14 . This provides a more stable footing for the interconnect 150 with the lower surface 164 of the insulative platform 152 resting on the surrounding sidewalls 26 , 70 of the casing portions 22 and 66 of the respective first and second capacitors 12 , 14 . The capacitors, which have their respective casings electrically insulated from each other by the intermediate double-sided adhesive 94 , are now serially connected to each other by the conductive bar 114 of the interconnect 150 extending from the positive polarity lead 42 of capacitor 12 to the negative polarity pin 128 of capacitor 14 .
[0072] This embodiment also shows making electrical connection to the series connected capacitors 12 , 14 by securing a footpad 166 /terminal lead 168 assembly to the casing of capacitor 14 . The assembly is of any conductive material previously described as being useful for conductive bar 114 . This is an alternative embodiment to the footpad 132 /terminal lead 134 assembly shown directly connected to the casing of capacitor 14 in FIGS. 9 and 10 . A positive polarity pin (not shown) extends from the opposite end of the capacitor 12 electrically insulated there from by a glass-to-metal feedthrough.
[0073] FIG. 15 is a cross-sectional view illustrating three side-by-side-by-side capacitors 12 , 14 and 170 serially connected together using two interconnects 150 . The third capacitor 170 can be either the same as or different than the capacitors 12 , 14 . However, for the sake of illustration, capacitor 170 is of an electrolytic type and is the same as capacitors 12 , 14 in its physical structure.
[0074] The casing for capacitor 170 is electrically insulated from that of capacitor 12 by an intermediate double-sided adhesive 94 . Then, the conductive bar 114 of the second interconnect 150 connects between a positive polarity pin 172 connected to the casing of capacitor 12 and the negative polarity lead 174 of capacitor 170 . A negative polarity pin 176 extends from the opposite end of capacitor 170 . Now, a load can be connected to the three serially connected capacitors 170 , 12 and 14 by connecting to the positive polarity lead 80 of capacitor 14 and the negative polarity pin 176 of capacitor 170 . Of course, those skilled in the art will recognize that if the various interconnects of the present invention can be used to connect two and three capacitors in a serial configuration, they can be used to connect four and more, as dictated by a particular application.
[0075] FIGS. 16 to 18 illustrate another embodiment of a capacitor interconnect 200 according to the present invention. This interconnect is similar to that of the interconnect 150 previously described with respect to FIGS. 12 to 14 . However, the insulative platform 202 has a surrounding oval-shaped sidewall 204 extending above an interior upper surface 206 . The sidewall 204 further has opposed protruding portions 208 and 210 . The lower surface 212 has a recess 214 centered between openings 216 , 218 and extending laterally from opposed straight portions of sidewall 204 .
[0076] The conductive bar 220 is an oval-shaped member of a similar material as bar 144 and comprises opposed openings 222 and 224 at either end with intermediate indentation portions 226 and 228 . In that respect, the conductive bar 220 is received in the space enclosed by the surrounding sidewall 204 resting on the upper surface 206 of the insulative platform 202 . The opposed protruding portions 208 , 210 are sized to closely match the opposed indentation portions 226 , 228 of the bar 220 . With the conductive bar 220 nested inside the surrounding platform sidewall 204 , the spaced apart openings 222 and 224 are exactly aligned with openings 216 and 218 in the insulative platform 202 . Also, the upper surface of the conductive bar 220 is coplanar with the upper surface of the surrounding platform sidewall 204 . Finally, the lower portions of the platform openings 216 and 218 are beveled to facilitate receiving the positive polarity anode lead 42 of capacitor 12 and the negative polarity pin 128 of capacitor 14 therein. As before, the upper end of lead 42 and pin 128 extending above the upper surface of the conductive bar 220 is removed when the conductive bar is welded to the lead and pin, such as by a laser.
[0077] In this position, the lower surface 212 of the insulative platform 202 rests on the surrounding sidewalls 30 , 74 of the casing portions 24 and 68 of the respective first and second capacitors 12 , 14 . The insulative platform 202 also rests on the foot 130 of the negative polarity pin 128 at the bevel of opening 126 . The capacitors, which have their respective casings electrically insulated from each other by the intermediate double-sided adhesive 94 , are now serially connected to each other by the conductive bar 220 of the interconnect 200 extending from the positive polarity lead 42 of capacitor 12 to the negative polarity pin 128 of capacitor 14 . In a similar manner as the previously described bar 114 , conductive bar 220 is now a suitable structure for making a wire bond connection between the series connected capacitors 12 , 14 and a medical device.
[0078] As shown in FIGS. 18A and 18B , to further facilitate a wire bond connection, the surrounding sidewall 204 A of the insulative platform 202 A is provided with a cutout 230 extending from the upper surface thereof to a distance spaced above the recess 214 A and centered between openings 216 A and 218 A. With the conductive bar 220 nested inside the surrounding platform sidewall 204 A, the cutout 230 exposes an edge portion 220 A of the bar. The conductive bar 220 can be of any of the previously listed materials, for example nickel, aluminum, or platinum plated or coated with gold. Gold can reside on the edge 220 as well as the upper surface thereof to provide a bonding pad or surface there for connection to the medical device
[0079] FIGS. 19 to 22 relate to a further embodiment of a capacitor interconnect 250 according to the present invention. Interconnect 250 is in the shape of an elongated pocket or cap of a similar material as the previously described bar 144 and having an upper wall 252 supporting a surrounding sidewall 254 extending to an oval-shaped edge 256 . The sidewall 254 extends outwardly from the upper wall 252 to the edge 256 and provides an opening sized so that the cap interconnect fits over and receives the positive polarity anode lead 42 of capacitor 12 and the negative polarity pin 128 of capacitor 14 . However, the sidewall 254 is of a height to prevent the cap 250 from contacting the casings of the capacitors 12 , 14 , as this will short them out.
[0080] As shown in FIG. 21 , the lead 42 and pin 128 reside adjacent to the opposite ends of the cap interconnect. The electrical connector is then made by physical deformation of the cap onto the lead and pin. First, a U-shaped backing plate 258 surrounds the cap interconnect 250 on three of its “sides”. A ram 260 then moves against the far portion of the surrounding sidewall 254 , crushing it down and into a locking relationship with the lead 42 and pin 128 . Preferably, this crushing force is sufficient to bring the opposed planar portions of the surrounding sidewall 254 into contact with each other.
[0081] FIGS. 23 to 25 illustrate another embodiment of a capacitor interconnect 300 according to the present invention. Interconnect 300 is a tubular U-shaped sleeve of a similar material as the previously described bar 144 and having a central portion 302 supporting opposed legs 304 and legs 306 . The central portion 302 is of a length such that the cylindrically shaped openings in legs 304 , 306 snuggly receive the positive polarity anode lead 42 of capacitor 12 and the negative polarity pin 128 of capacitor 14 in a co-axial relationship thereof. Welding the legs 304 , 306 to the lead 42 and pin 128 , such as by using a laser 308 makes the electrical connection. A weldment 310 at each leg then effects the connection.
[0082] FIG. 26 illustrates a further embodiment of a capacitor interconnect 350 according to the present invention. Interconnect 350 comprises the lead 42 and pin 128 having extending portions that were previously aligned in a side-by-side orientation and then subjected to a clamping force. This provides lead 42 having a distal portion 42 A lapping a distal portion 128 A of terminal pin 128 . The distal portions 42 A and 128 A provided in the side-by-side lap joint relationship are then secured together such as by a weldment 352 created by laser 354 .
[0083] FIG. 27 illustrates a further embodiment of a capacitor interconnect 400 according to the present invention. Interconnect 400 comprises the lead 42 and pin 128 having respective L-shaped distal portions 32 B and 128 B that are secured together by an intermediate sleeve 402 . This is done by first fitting one end of the sleeve over one of lead 42 and pin 128 , for example the distal portion 42 B of lead. The double-sided adhesive layer 94 has previously been contacted to the major face 32 of the casing portion 24 for capacitor 12 . Capacitor 14 is then moved into place putting the capacitors 12 , 14 in a side-by-side relationship with the face wall 76 of casing portion 68 contacting the other side of the adhesive 94 . As this occurs, the distal portion 128 B of pin 128 is fitted into the other end of sleeve 402 . A laser 404 is then used to secure the sleeve 402 to the distal portions 42 B and 128 B of the lead and pin. A weldment 406 is shown connecting the distal lead portion 42 B to the sleeve 402 .
[0084] Thus, according to the present invention, adjacent capacitors are connectable in series by connecting the anode terminal lead from one to the casing of another. The anode terminal lead can be connected to the next capacitor's casing by any one of the interconnects 100 , 150 , 200 , 250 , 300 , 350 and 400 . That way, any number of capacitors is serially connected together to increase the delivered capacity of the assembly. This is particularly important in advanced implantable medial devices, such as cardiac defibrillators, where delivered capacity coupled with reduced package volume is paramount in the minds of design engineers.
[0085] It is appreciated that various modifications to the inventive concepts described herein may be apparent to those of ordinary skill in the art without departing from the spirit and scope of the present invention as defined by the appended claims.
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Structures for serially connecting at least two capacitors together are described. Serially connecting capacitors together provides device manufactures, such as those selling implantable medical devices, with broad flexibility in terms of both how many capacitors are incorporated in the device and what configuration the capacitor assembly will assume.
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FIELD OF INVENTION
[0001] The present invention relates to the field of extracting resource(s) from a particular location. In particular, the present invention relates to the planning, design and processing related to a mine location in a manner based on enhancing the extraction of material considered of value, relative to the effort and/or time in extracting that material.
BACKGROUND ART
[0002] In the mining industry, once material of value, such as ore situated below the surface of the ground, has been discovered, there exists a need to extract that material from the ground.
[0003] In the past, one more traditional method has been to use a relatively large open cut mining technique, whereby a great volume of waste material is removed from the mine site in order for the miners to reach the material considered of value. For example, referring to FIG. 1 , the mine 101 is shown with its valuable material 102 situated at a distance below the ground surface 103 . In the past, most of the (waste) material 104 had to be removed so that the valuable material 102 could be exposed and extracted from the mine 101 . In the past, this waste material was removed in a series of progressive layers 105 , which are ever diminishing in area, until the valuable material 102 was exposed for extraction. This is not considered to be an efficient mining process, as a great deal of waste material must be removed, stored and returned at a later time to the mine site 101 , in order to extract the valuable material 102 . It is desirable to reduce the volume of waste material that must be removed prior to extracting the valuable material.
[0004] The open cut method exemplified in FIG. 1 is viewed as particularly inefficient where the valuable resource is located to one side of the pit 105 of a desirable mine site 101 . For example, FIG. 2 illustrates such a situation. The valuable material 102 is located to one side of the pit 105 . In such a situation, it is not considered efficient to remove the waste material 104 from region 206 , that is where the waste material is not located relatively close to the valuable material 102 , but it is considered desirable to remove the waste material 104 from region 207 , that is where it is located nearer to the valuable material 102 . This then rings other considerations to the fore. For example, it would be desirable to determine the boundary between regions 206 and 207 , so that not too much undesirable waste material is removed (region 206 ), yet enough is removed to ensure safety factors are considered, such as cave-ins, etc. This then leads to a further consideration of the need to design a ‘pit’ 105 with a relatively optimal design having consideration for the location of the valuable material, relative to the waste material and other issues, such as safety factors.
[0005] This further consideration has led to an analysis of pit design, and a technique of removing waste material and valuable material called ‘pushbacks’. This technique is illustrated in FIG. 3 . Basically, the pit 105 is designed to an extent that the waste material 104 to be removed is minimised, but still enabling extraction of the valuable material 102 . The technique uses ‘blocks’ 308 which represent smaller volumes of material. The area proximate the valuable material is divided into a number of blocks 308 . It is then a matter of determining which blocks need to be removed in order to enable access to the valuable material 102 . This determination of ‘blocks 308 ’, then gives rise to the design or extent of the pit 105 .
[0006] FIG. 3 represents the mine as a two dimensional area, however, it should be appreciated that the mine is a three dimensional area. Thus the blocks 308 to be removed are determined in phases, and cones, which represent more accurately a three dimensional ‘volume’ which volume will ultimately form the pit 105 .
[0007] Further consideration can be given to the prior art situation illustrated in FIG. 3 . Consideration should be given to the scheduling of the removal of blocks. In effect, what is the best order of block removal, when other business aspects such as time/value and discounted cash flows are taken into account? There is a need to find a relatively optimal order of block removal which gives a relatively maximum value for a relatively minimum effort/time.
[0008] Attempts have been made in the past to find this ‘optimum’ block order by determining which block(s) 308 should be removed relative to a ‘violation free’ order. Turning to the illustration in FIG. 4 , a pit 105 is shown with valuable material 102 . For the purposes of discussion, if it was desirable to remove block 414 , then there is considered to be a ‘violation’ if we determined a schedule of block removal which started by removing block 414 or blocks 414 , 412 & 413 before blocks 409 , 410 and 411 were removed. In other words, a violation free schedule would seek to remove other blocks 409 , 410 , 411 , 412 and 413 before block 414 . (It is important to note that the block number does not necessarily indicate a preferential order of block removal).
[0009] It can also be seen that this block scheduling can be extended to the entire pit 105 in order to remove the waste material 104 and the valuable material 102 . With this violation free order schedule in mind, prior art attempts have been made. FIG. 5 illustrates one such attempt. Taking the blocks of FIG. 4 , the blocks are numbered and sorted according to a ‘mineable block order’ having regard to practical mining techniques and other mine factors, such as safety etc and is illustrated by table 515 . The blocks in table 515 are then sorted 516 with regard to Net Present Value (NPV) and is based on push back design via Life-of-mine NPV sequencing, taking into account obtaining the most value block from the ground at the earliest time. To illustrate the NPV sorting, and turning again to FIG. 4 , there is a question as which of blocks 409 , 410 or 411 should be removed first. All three blocks can be removed from the point of view of the ability to mine them, but it may, for example, be more economic to remove block 410 , before block 409 . Removing blocks 409 , 410 or 411 does not lead to ‘violations’ thus consideration can be given to the order of block removal which is more economic.
[0010] The NPV sorting is conducted in a manner which does not lead to violations of the ‘violation free order’, and provides a table 517 listing an ‘executable block order’. In other words, this prior art technique leads to a listing of blocks in an order which determines their removal having regard to the ability to mine them, and the economic return for doing so.
[0011] Furthermore, a number of prior art techniques are considered to take a relatively simple view of the problems confronted by the mine designer in a ‘real world’ mine situation. For example, the size, complexity, nature of blocks, grade, slope and other engineering constraints and time taken to undertake a mining operation is often not fully taken into account in prior art techniques, leading to computational problems or errors in the mine design. Such errors can have significant financial and safety implications for the mine operator.
[0012] With regard to size, for example, prior art techniques fail to adequately take account of the size of a ‘block’. Depending on the size of the overall project, a ‘block’ may be quite large, taking some weeks, months or even years to mine. If this is the case, many assumptions made in prior art techniques fail to give sufficient accuracy for the modern day business environment.
[0013] Given that many of the mine designs are mathematically and computational complex, according to prior art techniques, if the size of the blocks were reduced for greater accuracy, the result will be that either the optimisation techniques used will be time in feasible (that is they will take an inordinately long time to complete), or other assumptions will have to be made concerning aspects of the mine design such as mining rates, processing rates, etc which will result in a decrease the accuracy of the mine design solution.
[0014] Some examples of commercial software do use mixed integer programming engines, however, the method of aggregating blocks requires further improvement. For example, it is considered that product ‘ECSI Maximiser’ by ECS international Pty Ltd uses a form of integer optimisation in their pushback design, but the optimisation is local in time, and it's problem formulation is considered too large to optimise globally over the life of a mine. Also the product ‘MineMax’ by MineMAX Ptd Ltd may be used to find a rudimentary optimal block sequencing with a mixed integer programming engine, however it is considered that it's method of aggregation does not respect slopes as is required in many situations. ‘MineMax’ also optimises locally in time, and not globally. Thus, where there are a large number of variables, the user must resort to subdividing the pit into separate sections, and perform separate optimisations on each section, and thus the optimisation is not global over the entire pit. It is considered desirable to have an optimisation that is global in both space and time.
[0000] Dynamic Programming Approach
[0015] The Lerchs-Grossman graph-theoretic algorithm (H. Lerchs & I. Grossman, “Optimum Design of Open-Pit Mines”, Transactions CIM, 1965) has been proved to give a relatively exact solution to the ultimate pit problem for an open-cut mine in three dimensions. Lerchs and Grossman also presents a dynamic programming approach to the problem in two dimensions, which has since been extended to three dimensions. However, solution of the three-dimensional graph theoretic algorithm is computationally inefficient in practical cases.
[0000] Linear Programming Approach
[0016] There is a linear program (LP), as presented by Underwood and Tolwinski (R. Underwood & B. Tolwinski, “A mathematical programming viewpoint for solving the ultimate pit problems”, EJOR, 1998). The availability of CPLEX (by Ilog, www.Ilog.com) as a powerful LP solver motivates investigation of the LP approach to the ultimate pit problem.
[0017] The ultimate pit problem can be modelled as an integer program (IP), where a value of 1 is assigned to blocks included in the ultimate pit, and a value of 0 is assigned otherwise. The IP formulation for the problem is then as follows.
[0018] Let
[0019] x i =1, if block i is included in the ultimate pit
0, otherwise
[0021] Then
max ∑ i v i x i
s . t . x i ≤ x j ∀ j ∈ P ( i ) x i ∈ { 0 , 1 } ∀ i equation 1
[0022] where
[0023] v i is the value assigned to block i
[0024] x i is the decision variable that designates whether block i is included in the ultimate pit or not
[0025] P(i) is the set of predecessor blocks of block i.
[0026] One objective is to maximise the net value of the material removed from the pit. Consider that the only constraints are precedence constraints, which enforce the requirement of safe wall slopes in the mine. In fact, this IP formulation has she property of total unimodularity. That is, the solution of the LP relaxation of this formulation will be integral (i.e. a set of 0's and 1's). This is an extremely desirable property for an integer program. It allows the IP to be solved as an LP using the Simplex method. This leads to greatly increased solution efficiency in terms of both CPU time and memory requirements. The exact mathematical formulation of the linear programming approach to the ultimate pit problem is therefore
max ∑ i v i x i
s . t . x i ≤ x j ∀ j ∈ P ( i ) 0 ≤ x i ≤ 1 ∀ i equation 2
[0027] This is the ideal approach to solve the problem, and is considered to give the optimal solution in every case. Unfortunately, implementation of this exact formulation in CPLEX fails to solve for mining projects of realistic size. Since the optimisation is carried out at the block level, and there is a constraint for every precedence arc for each block, a very large number of constraints are applied. For example, it a mine has 198,917 blocks, and after CPLEX performs pre-processing on the formulation, the resulting reduced LP still has 1,676,003 constraints. CPLEX attempts to solve this formulation using the dual simplex method, generally recognized as the most efficient method for solving linear programs of this size. However, in the case of the example mine, CPLEX was found to crash during the solution process due to the very large number of constraints. Inversion of a constraint matrix of this magnitude (as required for converting solutions obtained from the dual simplex method back into primal space) is considered to place too great a memory requirement on the system.
[0028] There still exists a need, however, to improve prior art techniques. Given that mining projects, on the whole, are relatively large scale operations, even small improvements in prior art techniques can represent millions of dollars in savings, and/or greater productivity and/or safety.
[0029] It is desirable to provide an improved mine design.
[0030] An object of the present invention is to provide an improved method of pit design, which takes into account slope constraints.
[0031] Another object of the present invention is to provide an improved method of determining a cluster.
[0032] A further object of the present invention is to determine which blocks of a mine pit provide a relative maximum net value of material, also having regard to practical limitations, such as slope constraints.
[0033] Yet another object of the present invention is to alleviate at least one disadvantage of the prior art.
[0034] Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms a part of the prior art base or the common general knowledge in the relevant art in Australia or elsewhere on or before the priority date of the disclosure and claims herein.
SUMMARY OF INVENTION
[0035] The present invention provides, in a first inventive aspect, a method of and apparatus for determining slope constraints related to a design configuration for extracting material from a particular location, the method including the steps of determining a selected volume of material to be extracted, dividing at least a portion of the selected volume into blocks, forming a plurality of cones, at least one cone from each block, and determining from the cones, a clump having a corresponding slope constraint.
[0036] Preferably, the cone is propagated upwards using precedence arcs.
[0037] The present aspect also provides a method of determining slope constraints related to a design configuration for extracting material from a particular location, in which precedent arcs emanating from a selected block(s) are used to establish, at least in part, slope constraints.
[0038] The present aspect also provides a mine designed in accordance with the method as disclosed herein.
[0039] The present aspect further provides a computer program product including a computer usable medium having computer readable program code and computer readable system code embodied on said medium for determining slope constraints related to a design configuration for extracting material from a particular location within a data processing system, the computer program product including computer readable code within said computer usable medium for performing the method as disclosed herein.
[0040] In essence, the present invention, referred to as Propagation of clusters and formation of clumps, forms relatively minimal inverted cones with clusters at their apex and intersects these cones to form clumps, or aggregations of blocks that respect slope constraints. Advantageously, it has been found that aggregating the small blocks in an intelligent way serves to reduce the number of “atoms” variables to be fed into the mixed integer programming engine. The clumps allow relatively maximum flexibility in potential mining schedules, while keeping variable numbers to a minimum. The collection of clumps has three important properties. Firstly, the clumps allow access to all the targets as quickly as possible (minimalilty), and secondly the clumps allow many possible orders of access to the identified ore targets (flexibility). Thirdly, because cones are used, and due to the nature of the cone(s), an extraction ordering of the clumps that is feasible according to the precedence arcs will automatically respect and accommodate minimum slope constraints. Thus, the slope constraints are automatically built into this aspect of invention.
[0041] In other words, the present invention provides that clumps are determined from the overlap of cones. The cones are preferably ‘minimal’.
[0042] The present invention provides, in a second inventive aspect, a method of and apparatus for determining a duster of material, the method including
[0043] allocating at least a portion of the material between a plurality of blocks,
[0044] determining a first attribute related to co-ordinates corresponding to each block,
[0045] assigning the first attribute to each corresponding block,
[0046] determining a second attribute related to the plurality of blocks, and
[0047] aggregating at least two of the plurality of blocks in accordance with the first attribute and the second attribute.
[0048] In essence, the second related aspect of invention, referred to as initial Identification of Clusters, aggregates a number of blocks into collections or clusters. The dusters preferably more sharply identify regions of high-grade and low-grade materials, while maintaining a spatial compactness of a cluster. The clusters are formed by blocks having certain x, y, z spatial coordinates, combined with another coordinate, representing a number of selected values, such as grade or value. The advantage of this is to produce inverted cones that are relatively tightly focused around regions of high grade so as not to necessitate extra stripping.
[0049] In other words, where there is an ore body having a number of blocks, the present invention deals with building cones and clumps etc from the information known about the ore body and it's blocks.
[0050] The present invention provides, in a third inventive aspect, a method and apparatus of determining characteristics of a selected portion of material, the method including determining the contents of the selected portion of material, and identifying region(s) of material within the selected portion according to at least one of a plurality of characteristic(s).
[0051] In essence, a third related aspect of invention, referred to as splitting of waste and ore in clumps, is based on the realisation that clumps contain both ore blocks and waste blocks. Many integer programs assume that the value is distributed uniformly within a clump. This is, however, not true. Typically, clumps will have higher value near their base. This is because most of the value is lower underground while closer to the surface one tends to have more waste blocks. By splitting the clump into relatively pure waste and desirable material, the assumption of uniformity of value for each portion of the clump is more accurate.
[0052] In other words, the present invention reflects the consideration to determine, where necessary, block ‘grade’. If the ore is above a certain value, then the cone may be divided into smaller cones, and reiterated for more precise determination and extraction.
[0053] The present invention provides, in a fourth inventive aspect, a method of and apparatus for analysing a selected volume of material, the material being at least partially comprised of a plurality of blocks, the method including the steps of clumping a number of blocks together, and
[0054] analysing the selected volume of material based on the clumped blocks.
[0055] In essence, a fourth related aspect of invention, referred to as Aggregation of blocks into clumps; high-level ideas, reduces the number of variables to a relatively manageable amount for use in current technology of integer programming engines. Advantageously, this aspect enables the use of an integer programming engine and the ability to incorporate further constraints such as mining, processing, and marketing capacities, and grade constraints.
[0056] The present invention provides, in a fifth inventive aspect, a method of determining a selected group of blocks of a mine pit which are capable of being mined, the method including the steps of selecting a plurality of blocks, and determining a relative value and constraints applicable to the selected blocks in accordance with any one of the equations 3, 4 or 9 as disclosed herein.
[0057] The present invention also provides the method as described above and including the further step of testing for violations.
[0058] The present invention also seeks to reiterate the selection and determination of value and constraints of blocks in order to obtain a group of blocks which have a relative optimal mining value.
[0059] In essence, the present aspect, in one form, utilises aggregating algorithm(s) to determine a selected group of blocks which are to be mined, where the selection of blocks to be, included into the group of blocks is made relative to value and constraints applicable to the blocks. The present invention, in another aspect further tests for violations, and iteratively recalculates until substantially all violations are removed. Given a block model of an ore body containing value-in-ground and designated slope constraints, the ultimate pit problem concerns the determination of the shape of the final pit of the mine. It is assumed that all the material can be removed at once. That is, the effect of time on the value of the ore body is not considered. In terms of mine scheduling, the ultimate pit can be used as the initial collection of blocks on which a scheduling algorithm is run. In this respect, the ultimate pit is the largest possible final pit that can be realised following scheduling of removal of the ore body. The case considered throughout this disclosure is that of base metals but also has application to blended products or stochastic elements of open-pit mining.
[0060] In other words, the present invention is used to determine how to split a relatively large ore body into clump(s). The present invention can be used to ensure that the clump or ore body is not too large, computationally, for example for practical consideration with the use of existing algorithms.
[0061] Other related aspects of invention, include:
[0062] In essence, one related aspect of invention, referred to as Generic Klumpking, is a method of mine design that firstly, is considered a clever choice of aggregation to reduce the number of variables via a spatial/value clustering and propagation to form clumps. Secondly, the inclusion of mining and processing constraints in an integer program based around the clump variables to ultimately produce an optimal block sequence. Thirdly, the rapid loop of clustering blocks in this optimal sequence according to space/time of extraction and propagating these clusters to form pushbacks, interrogating them for value and mineability, and adjusting clustering parameters as needed.
[0063] In essence, another related aspect of invention, referred to as Determination of a block ordering from a clump ordering, turns a clump ordering into an ordering of blocks. This is, in effect, a de aggregation. Using techniques disclosed herein, the integer program engine was used on the relatively small number of clumps, and thus the result can now be translated back into the large number of small blocks.
[0064] In essence, still another related aspect of invention, referred to as fuzzy clustering; second identification of clusters for pushback design, clusters blocks according to their spatial position and their time of extraction. This is considered necessary because if pushbacks were formed from the block sequence in its raw form, the pushbacks would be generally highly fragmented and considered non-mineable. The clustering gives control over the connectivity and mineability of the resulting pushbacks.
[0065] In essence, still another related aspect of invention, referred to as fuzzy clustering; alternative 1, clusters blocks according to their spatial position and their time of extraction. The clusters may be controlled to be a certain size, or have a certain rock tonnage or ore tonnage. The shapes of the clusters may be controlled through parameters that balance the space and the time coordinate. The advantage of shape control is to produce pushbacks that are mineable and not fragmented. The advantage of size control is the ability to control stripping ratios in years where the mill may be operating under capacity.
[0066] In essence, a further related aspect of invention, referred to as fuzzy clustering; alternative 2, propagates inverted cones from the clusters identified in the secondary clustering. The clusters in the secondary clustering are time ordered, and the propagation occurs in this time order, with no intersections of inverted cones allowed. Advantageously, this provides the ability to extract pushbacks from the block ordering that are well connected and mineable, while retaining the bulk of the NPV optimality of the block sequence.
[0067] In essence, still a further related aspect of invention, referred to as fuzzy clustering; alternative 3, provides the creation of a feedback loop of clustering, propagating to find pushbacks, valuing relatively quickly, and then feeding this information back into the choice of clustering parameters. The advantage of this is that the effect of different clustering parameters may be very quickly checked for NPV and mineablity. It is heretofore been virtually impossible to evaluate a pushback design for NPV and mineability before it has been constructed, and the fast process loop of this aspect allows many highquality pushbacks designs to be constructed and evaluated (by the human eye in the case of mineability).
[0068] Other aspects and preferred aspects are disclosed in the specification and/or defined in the appended claims.
[0069] The method(s), systems and techniques disclosed in this application may be used in conjunction with prior art integer programming engines. Many aspects of the present disclosure serve to improve the performance of the use of such engines and the use of other known mine design techniques.
[0070] The present invention may be used, for example, by mine planners to design relatively optimal pushbacks for open cut mines. Advantageously, the present invention is considered is different to prior art pushback design software in that:
The present invention does not use either of the most common pit design algorithms (Lerchs-Grossmann or Floating Cone) but instead uses a unique concept of optimal “clump” sequencing to develop an optimal block sequence that is then used as a basis for pushback design. The design is relatively optimal with respect to properly discounted block values. No other pushback design software is considered to correctly allow for the effect of time (viz: block value discounting) in the pushback design step. Traditional phase designs ignore medium grade ore pods close to the surface with good NPV whilst focusing on higher value pods that may be deeply buried. The present invention can properly address the so-called “Whittle-gap” problem where consecutive Lerchs-Grossmann shells can be very far apart, offering little temporal information. The present invention obtains relatively complete and accurate temporal information on the block ordering. Process and mining constraints can be explicitly incorporated into the pushback design step. The planner can rapidly design and value pushbacks that have different topologies, the trade-off being between pits with high NPV, but with difficult-to-mine (eg: ring) pushback shapes, and those with more mineable pushback shapes but lower NPV. The advantage of the more mineable pushback shapes is that much less NPV will be wasted in enforcing minimum mining width and in accommodating pit access (roads and berms). The ability to quickly generate and evaluate a number of different sets of candidate pushback designs is a feature not allowed in traditional pushback design software where design options are usually fairly limited (eg: the amalgamation of adjacent Whittle shells into a single pushback) Various aspects of the present invention also serve to improve the use of existing integer programming engines, such as “cplex” by ILOG.
[0078] Throughout the specification:
1. a ‘collection’ is a term for a group of objects, 2. a ‘cluster’ is a collection of ore blocks or blocks of otherwise desirable material that are relatively close to one another in terms of space and/or other attributes, 3. a ‘clump’ is formed from a cluster by first producing a substantially minimal inverted cone extending from the cluster to the surface of the pit by propagating all blocks in the cluster upwards using the arcs that describe the minimal slope constraints. Each cluster will have its own minimal inverted cone. These minimal inverted cones are then intersect with one another and the intersections form clumps, and 4. an ‘aggregation’ is a term, although mostly applied to collections of blocks that are spatially connected (no “holes” in them). For example, a clump may be an aggregation, or may be “Super blocks” that are larger cubes made by joining together smaller cubes or blocks. 5. reference to block constraints equally implies reference to arc constraints. 6. a block may also refer to a number of blocks.
DESCRIPTION OF DRAWINGS
[0085] Further disclosure, objects, advantages and aspects of the present application may be better understood by those skilled in the relevant art with reference to the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:
[0086] FIGS. 1 to 5 illustrate prior art mining techniques,
[0087] FIG. 6 illustrates, schematically, a flow chart outlining the overall process according to one aspect of invention,
[0088] FIG. 7 illustrates schematically the identification of clusters,
[0089] FIG. 8 illustrates schematically cone propagation in pit design,
[0090] FIG. 9 illustrates schematically the splitting or ore from waste material,
[0091] FIG. 10 illustrates an example of ‘fuzzy clustering’ in a mine site,
[0092] FIGS. 11 a, 11 b and 11 c illustrate a secondary clustering, propagation, and NPV valuation process,
[0093] FIG. 12 illustrates a comparison between outcomes of equations 2 and 4,
[0094] FIG. 13 illustrates a vertical cross-section of a pit design using equation 2,
[0095] FIG. 14 illustrates a vertical cross-section of a pit design using equation 4,
[0096] FIG. 15 illustrates an example portion of a pit,
[0097] FIGS. 16 and 18 illustrate a plane view through a pit using the cutting plane formulation (equation 9), and
[0098] FIGS. 17 and 19 illustrate the same view as that of FIGS. 16 and 18 but for the use of the LP relaxation of the aggregated formulation (equation 4).
DETAILED DESCRIPTION
[0099] In order to more fully describe the present invention, a number of related aspects will also be described. In this way, the reader can gain a better understanding of the context and scope of the present invention.
[0000] 1. Generic KlumpKing
[0100] FIG. 6 illustrates, schematically an overall representation of one aspect of invention.
[0101] Although specific aspects of various elements of the overall flow chart are discussed below in more detail, it may be helpful to provide an outline of the flow chart illustrated in FIG. 6 .
[0102] Block model 601 , mining and processing parameters 602 and slope constraints 603 are provided as input parameters. When combined, precedence arcs 604 are provided. For a given block, arcs will point to other blocks that must be removed before the given block can be removed.
[0103] As typically, the number of blocks can be very large, at 605 , blocks are aggregated into larger collections, and clustered. Cones are propagated from respective clusters and clumps are then created 606 at intersections of cones. The number of clumps is now much smaller than the number of blocks, and clumps include slope constraints. At 607 , the clumps may then be scheduled in a manner according to specified criteria, for example, mining and processing constraints and NPV. It is of great advantage that the scheduling occurs with clumps (which number much less than blocks). It is, in part, the reduced number of clumps that provides a relative degree of arithmetic simplicity and/or reduced requirements of the programming engine or algorithms used to determine the schedule. Following this, a schedule of individual block order can be determined from the clump schedule, by de-aggregating. The step of polish at 608 is optional, but does improve the value of the block sequence.
[0104] From the block ordering, pushbacks can be designed 609 . Secondary clustering can be undertaken 610 , with an additional fourth co-ordinate. The fourth co-ordinate may be time, for example, but may also be any other desirable value or parameter. From here, cones are again propagated from the clusters, but in a sequence commensurate with the fourth co-ordinate. Any blocks already assigned to previously propagated cones are not included in the next cone propagation. Pushbacks are formed 611 from these propagated cones. Pushbacks may be viewed for mineabillty 612 . An assessment as to a balance between mineability and NPV can be made at 613 , whether in accordance with a predetermined parameter or not. The pushback design can be repeated if necessary via path 614 .
[0105] Other consideration can also be taken into account, such as minimum mining width 615 , and validation 616 . Balances can be taken into account for mining constraints, downstream processing constraints and/or stockpiling options, such as blending and supply chain determination and/or evaluation.
[0106] The following description focuses on a number of aspects of invention which reside within the overall flow chart disclosed above. For the purposes of FIG. 6 , sections 2 and 5 are associated with 605 , sections 3 , 4 and 5 are associated with 606 , sections 4 , 6 are associated with 607 , sections 7 and 7 . 3 are associated with 610 , sections 7 . 2 and 7 . 3 are associated with 611 , section 7 . 3 is associated with 612 , 613 and 614 , and sections 7 , 7 . 1 , 7 . 2 and 7 . 3 are associated with 609 .
[0000] 1.1 Inputs and Preliminaries
[0107] Input parameters include the block model 601 , mining and processing parameters 602 , and slope constraints 603 . Slope regions (eg. physical areas or zones) are contained in 601 ; slope parameters <eg. slopes and bearings for each zone> are contained in 602 .
[0108] The block model 601 contains information, for example, such as the value of a block in dollars, the grade of the block in grams per tonne, the tonnage of rock in the block, and the tonnage of ore in the block.
[0109] The mining and processing parameters 602 are expressed in terms of tonnes per year that may be mined or processed subject to capacity constraints.
[0110] The slope constraints 603 contain information about the maximal slope around in given directions about a particular block.
[0111] The slope constraints 603 and the block model 601 when combined give rise to precedence arcs 604 . For a given block, arcs will point from the given block to all other blocks that must be removed before the given block. The number of arcs is reduced by storing them in an inductive, where, for example, in two dimensions, an inverted cone of blocks may be described by every black pointing to the three blocks centred immediately above it. This principle can also be applied to three dimensions. If the inverted cone is large, for example having a depth of 10, the number of arcs required would be 100; one for each block. However, using the inductive rule of “point to the three blocks centred directly above you”, the entire inverted cone may be described by only three arcs instead of the 100. In this way the number of arcs required to be stored is greatly reduced. As block models typically contain hundreds of thousands of blocks, with each block containing hundreds of arcs, this data compression is considered a significant advantage.
[0000] 1.2 Producing an Optimal Block Ordering
[0112] The number of blocks in the block model 601 is typically far too large to schedule individually, therefore it is desirable to aggregate the blocks into larger collections, and then to schedule these larger collections. To proceed with this aggregation, the ore blocks are clustered 605 (these are typically located towards the bottom of the pit. In one preferred form, those blocks with negative value, which are taken to be waste, are not clustered). The ore blocks are clustered spatially (using their x, y, z coordinates) and in terms of their grade or value. A balance is struck between having spatially compact clusters, and clusters with similar grade or value within them. These clusters will form the kernels of the atoms of aggregation.
[0113] From each cluster, an (imaginary) inverted cone is formed, by propagating upwards using the precedence arcs. This inverted cone represents the minimal amount of material that must be excavated before the entire cluster can be extracted. Ideally, for every cluster, there is an inverted cone. Typically, these cones will intersect. Each of these intersections (including the trivial intersections of a cone intersecting only itself) will form an atom of aggregation, which is call a clump. Clumps are created, represented by 606 .
[0114] The number of clumps produced is now far smaller than the original number of blocks. Precedence arcs between clumps are induced by the precedence arcs between the individual blocks. An extraction ordering of the clumps that is feasible according to these precedence arcs will automatically respect minimum slope constraints. It is feasible to schedule these clumps to find a substantially NPV maximal, clump schedule 607 that satisfies all of the mining and processing constraints.
[0115] Now that there is a schedule of clumps 607 , this can be turned into a schedule of individual blocks. One method is to consider all of those clumps that are begun in a calendar year one, and to excavate these block by block starting from the uppermost level, proceeding level by level to the lowermost level. Other methods are disclosed in Section 6 of this specification. Having produced this block ordering, the next step may be to optionally Polish 608 the block ordering to further improve the NPV.
[0116] In a more complex case, the step of polish 608 can be bypassed. If it is desirable, however, polishing can be performed to improve the value of the block sequence.
[0000] 1.3 Balanced NPV Optimal/Mineable Pushback Design from Block Ordering
[0117] From this block ordering, we can produce pushbacks, via pushback design 609 . Advantageously, the present invention enables the creation of pushbacks that allow for NPV optimal mining schedules. A pushback is a large section of a pit in which trucks and shovels will be concentrated to dig, sometimes for a period of time, such as for one or more years. The block ordering gives us a guide as to where one should begin and end mining. In essence, the block ordering is an optimal way to dig up the pit. However, often this block ordering is not feasible because the ordering suggested is too spatially fragmented. In an aspect of invention, the block ordering is aggregated so that large, connected portions of the pits are obtained (pushbacks). Then a secondary clustering of the ore blocks can be undertaken 610 . This time, the clustering is spatial (x, y, z) and has an additional 4th coordinate, which represents the block extraction time ordering. The emphasis of the 4th coordinate of time may be increased and decreased. Decreasing the emphasis produces clusters that are spatially compact, but ignore the optimal extraction sequence. Increasing the emphasis of the 4th coordinate produces clusters that are more spatially fragmented but follow the optimal extraction sequence more closely.
[0118] Once the clusters have been selected (and ordered in time), inverted cones are propagated upwards in time order. That is, the earliest cluster (in time) is propagated upwards to form an inverted cone. Next, the second earliest cluster is propagated upwards. Any blocks that are already assigned to the first cone are not included in the second cone and any subsequent cones. Likewise, any blocks assigned to the second cone are not included in any subsequent cones. These propagated cones or parts of cones form the pushbacks 611 . This secondary clustering, propagation, and NPV valuation is relatively rapid, and the intention is that the user would select an emphasis for the 4th coordinate of time, perform the propagation and valuation, and view the pushbacks for mineability 612 . A balance between mineability and NPV can be accessed 613 , and if necessary the pushback design steps can be repeated, path 614 . For example, if mineability is too fragmented, the emphasis of the 4th coordinate would be reduced. If the MPV from the valuation is too low, the emphasis of the 4th coordinate would be increased.
[0119] Once a pushback design has been selected, a minimum mining width routine 615 is run on the pushback design to ensure that a minimum mining width is maintained between the pushbacks and themselves, and the pushbacks and the boundary of the pit. An example in the open literature is “The effect of minimum mining width on NPV” by Christopher Wharton & Jeff Whittle, “Optimizing with Whittle” Conference, Perth, 1997.
[0000] 1.4 Further Valuation
[0120] A more sophisticated valuation method 616 is possible at this final stage that balances mining and processing constraints, and additionally could take into account stockpiling options, such as blending and supply chain determination and/or evaluation.
[0000] 2 Initial Identification of Clusters
[0121] It has been found that the number of blocks in a block model is typically far too large to schedule individually, therefore in accordance with one related aspect of invention, the blocks are aggregated into larger collections. These larger collections are then preferably scheduled. Scheduling means assigning a clump to be excavated in a particular period or periods.
[0122] To proceed with the aggregation, a number of ore blocks are clustered. Ore blocks are identified as different from waste material. The waste material is to be removed to reach the ore blocks. The ore blocks may contain substantially only ore of a desirably quality or quantity and/or be combined with other material or even waste material. The ore blocks are typically located towards the bottom of the pit, but may be located any where in the pit. In accordance with a preferred aspect of the present invention, the ore blocks which are considered to be waste are given a negative value, and the ore blocks are not clustered with a negative value. It is considered that those blocks with a positive value, present themselves as possible targets for the staging of the open pit mine. This approach is built around targeting those blocks of value, namely those blocks with positive value. Waste blocks with a negative value are not considered targets and are therefore this aspect of invention does not cluster those targets. The ore blocks are clustered spatially (using their x, y, z coordinates) and in terms of their grade or value. Preferably, limits or predetermined criteria are used in deciding the clusters. For example, what is the spatial limit to be applied to a given cluster of blocks? Are blocks spaced 10 meters or 100 meters apart considered one cluster? These criteria may be varied depending on the particular mine, design and environment. For example, FIG. 7 illustrates schematically an ore body 701 . Within the ore body are a number of blocks 702 , 703 , 704 and 705 . (The ore body has many blocks, but the description will only refer to a limited number for simplicity) Each block 702 , 703 , 704 and 705 has its own individual x, y, z coordinates. If an aggregation is to be formed, the coordinates of blocks 702 , 703 , 704 and 705 can be analysed according to a predetermined criteria. If the criteria is only distance, for example, then blocks 702 , 703 and 704 are situated closer than block 705 . The aggregation may be thus formed by blocks 702 , 703 and 704 . However, if, in accordance with this aspect of invention, another criteria is also used, such as grade or value, blocks 702 , 703 and 705 may be considered an aggregation as defined by line 706 , even though block 704 is situated closer to blocks 702 and 703 . A balance is struck between having spatially compact clusters, and clusters with similar grade or value within them. These clusters will form the kernels of the atoms of aggregation. It is important that there is control over spatial compactness versus the grade/value similarity. If the clusters are too spatially separated, the inverted cone that we will ultimately propagate up from the duster (as will be described below) will be too wide and contain superfluous stripping. If the clusters internally contain too much grade or value variation, there will be dilution of value. It is preferable for the clusters to substantially sharply identify regions of high grade and low-grade separately, while maintaining a spatial compactness of the clusters. Such clusters have been found to produce high-quality aggregations.
[0123] Furthermore, where a relatively large body of ore is encountered, the ore body may be divided into a relatively large number of blocks. Each block may have substantially the same or a different ore grade or value. A relatively large number of blocks will have spatial difference, which may be used to define aggregates and clumps in accordance with the disclosure above. The ore body, in this manner may be broken up into separate regions, from which individual cones can be defined and propagated.
[0000] 3 Propagation of Clusters and Formation of Clumps
[0124] From each cluster, an inverted cone (imaginary) is formed. A cone is referred to as a manner of explaining visually to the reader what occurs. Although the collection of blocks forming the cone does look like a discretised cone to the human eye. In a practical embodiment, this step would be simulated mathematically by computer. Each cone is preferably a minimal cone, that is, not over sized. This cone is represented schematically or mathematically, but for the purposes of explanation it is helpful to think of an inverted cone propagating upward of the aggregation. The inverted cone can be propagated upwards of the atom of aggregation using the precedence arcs. Most mine optimisation software packages use the idea of precedence arcs. The cone is preferably three dimensional. The inverted cone represents the minimal amount of material that must be excavated before the entire cluster can be extracted. In accordance with a preferred form of this aspect of invention, every cluster has a corresponding inverted cone.
[0125] Typically, these cones will intersect another cone propagating upwardly from an adjacent aggregation. Each intersection (including the trivial intersections of a cone intersecting only itself) will form an atom of aggregation, which is call a ‘clump’, in accordance with this aspect. Precedence arcs between clumps are induced by the precedence arcs between the individual blocks. These precedence arcs are important for identifying which extraction ordering of clumps are physically feasible and which are not. Extraction orderings must be consistent with the precedence arcs. This means that if block/clump A points to block/clump B, then block/clump B must be excavated earlier than block/clump A.
[0126] With reference to FIG. 8 , illustrating a pit 801 , in which there are ore bodies 802 , 803 , and 804 . Having identified the important “ore targets” in the stage of initial identification of clusters, as described above, the procedure of propagation and formation of clumps goes on to produce mini pits (clumps) that are the most efficient ways access these “ore targets”. The clumps are the regions formed by an intersection of the cones, as well as the remainder of cones once the intersected areas are removed. In accordance with the embodiment aspect, intersected areas must be removed before any others, eg. 814 must be dug up before either 805 or 806 , in FIG. 8 . In accordance with the description above, cones 805 , 806 and 807 are propagated (for the purposes of illustration) from ore bodies to be extracted. The cones are formed by precedence arcs 808 , 809 , 810 , 811 , 812 and 813 . In FIG. 8 , for example, clumps are designated regions 814 and 815 . Other clumps are also designated by what is left of the inverted cones 805 , 806 and 807 when 814 and 815 have been removed. The clump area is the area within the cone. The overlaps, which are the intersections of the cones, are used to allow the excavation of the inverted cones in any particular order. The collection of clumps has three important properties. Firstly, the clumps allow access to the all targets as quickly as possible (minimality), and secondly the clumps allow many possible orders of access to the identified ore targets (flexibility). Thirdly, because cones are used, an extraction ordering of the clumps that is feasible according to the precedence arcs will automatically respect and accommodate minimum slope constraints. Thus, the slope constraints are automatically built into this aspect of invention.
[0000] 4 Splitting of Waste and Ore in Clumps
[0127] Once the initial clumps have been formed, a search is performed from the lowest level of the clump upwards. The highest level at which ore is contained in the clump is identified; everything above this level is considered to be waste. The option is given to split the clump into two pieces; the upper piece contains waste, and the lower piece contains a mixture of waste and ore. FIG. 9 illustrates a pit 901 , in which there is an ore body 902 . From the ore body, precedence arcs 903 and 904 define a cone propagating upward. In accordance with this aspect of invention, line 905 is identified as the highest level of the clump 902 . Then 906 can designate ore, and 907 can designate waste. This splitting of waste from ore designations is considered to allow for a more accurate valuation of the clump. Many techniques assume that the value within a clump is uniformly distributed, however, in practice this is often not the case. By splitting the clump into two pieces, one with pure waste and the other with mostly ore, the assumption of homogeneity is more likely to be accurate. More sophisticated splitting based on finer divisions of value or grade are also possible in accordance with predetermined criteria, which can be set from time to time or in accordance with a particular pit design or location.
[0000] 5 Aggregation of Blocks into Clumps: High-Level Ideas
[0128] The feature of ‘clumping blocks together’ may be viewed for the purpose of arithmetic simplicity where the number of blocks are too large. The number of clumps produced is far smaller than the original number of blocks. This allows a mixed integer optimisation engine to be used, otherwise the use of mixed integer engines would be considered not feasible. For example, Cplex by ILOG may be used. This aspect has beneficial application to the invention disclosed in pending provisional patent application no. 2002961892, titled “Mining Process and Design” filed Oct. 10, 2002 by the present applicant, and which is herein incorporated by reference. This aspect can be used to reduce problem and calculation size for other methods (such as disclosed in the co-pending application above).
[0129] The number of clumps produced is far smaller than the original number of blocks. This allows a mixed integer optimisation engine to be used. The advantage of such an engine is that a truly optimal (in terms of maximising NPV) schedule of clumps may be found in a (considered) feasible time. Moreover this optimal schedule satisfies mining and processing constraints. Allowing for mining and processing constraints, the ability to find truly optimal solutions represents a significant advance over currently available commercial software. The quality of the solution will depend on the quality of the clumps that are input to the optimisation engine. The selection procedures to identify high quality clumps have been outlined in the sections above.
[0130] Some commercial software, as noted in the background section of this specification, do use mixed integer programming engines, however, the method of aggregating blocks is different either in method, or in application, and we believe of lower-quality. For example, it is considered that ‘ECSI Maximiser’ uses a form of integer optimisation in their pushback design, and restricts the time window for each block, but the optimisation is local in time, and it's problem formulation is considered too large to optimise globally over the life of a mine. In contrast, in accordance with the present invention, a global optimisation over the entire life of mine is performed by allowing clumps to be taken at any time from start of mine life to end of mine life. ‘MineMax’ may be used to find rudimentary optimal block sequencing with a mixed integer programming engine, however it is considered that it's method of aggregation does not respect slopes as is required in many situations. ‘MineMax’ also optimises locally in time, and not globally. In use, there is a large huge number of variables, and the user must therefore resort to subdividing the pit to perform separate optimisations, and thus the optimisation is not global over the entire pit. The present invention is global in both space and time.
[0000] 6 Determination of a Block Ordering from a Clump Ordering
[0131] Now that there is a schedule of clumps, it is desirable to turn this into a schedule of individual blocks. One method is to consider all of those clumps that are begun in year one, and to excavate these block by block starting from the uppermost level, proceeding level by level to the lowermost level. One then moves on to year two, and considers all of those clumps that are begun in year two, excavating all of the blocks contained in those clumps level by level from the top level through to the bottom level. And so on, until the end of the mine life.
[0132] Typically, some clumps may be extracted over a period of several years. This method just described is not as accurate as may be required for some situations, because the block ordering assumes that the entire clump is removed without stopping, once it is begun. Another method is to consider the fraction of the clump that is taken in each year. This method begins with year one, and extracts the blocks in such a way that the correct fractions of each clump for year one are taken in approximately year one. The integer programming engine assigns a fraction of each clump to be excavated in each period/year. This fraction may also be zero. This assignment of clumps to years or periods must be turned into a sequence of blocks. This may be done as follows. If half of the clump A is taken in year one, and one third of clump B is taken in year one, and all other fractions of clumps in year one are zero, the blocks representing the upper half of clump A and the blocks representing the upper one-third of clump B are joined together. This union of blocks is then ordered from the uppermost bench to the lowermost bench and forms the beginning of the blocks sequence (because we are dealing with year one). One then moves on to year two and repeats the procedure, concatenating the blocks with those already in the sequence.
[0133] Having produced this block ordering, block ordering may be in a position to be optionally Polished to further improve the NPV. The step of Polishing is similar to the method disclosed in co-pending application 2002951892 (described above, and incorporated herein by reference) but the starting condition is different. Rather than best value to lowest value, as is disclosed in the co-pending application, in the present aspect, the start is with the block sequence obtained from the clump schedule.
[0000] 7 Second Identification of Clusters for Pushback Design
[0000] 7.1 Fuzzy Clustering; Alternative 1 (Space/Time Clustering of Block Sequence)
[0134] From this block ordering, we must produce pushbacks. This is the ultimate goal of KlumpKing—to produce pushbacks that allow for NPV optimal mining schedules. A pushback is a large section of a pit in which trucks and shovels will be concentrated for one or more years to dig. The block ordering gives us a guide as to where one should begin and end mining. In principle, the block ordering is the optimal way to dig up the pit. However, it is not feasible, because the ordering is too spatially fragmented. It is desirable to aggregate the block ordering so that large, connected portions of the pits are obtained (pushbacks). A secondary clustering of the ore blocks is undertaken. This time, clustering is spatially (x, y, z) and as a 4th coordinate, which is used for the block extraction time or ordering. The emphasis of the 4th coordinate of time may be increased or decreased. Decreasing the emphasis produces clusters that are spatially compact, but tend to ignore the optimal extraction sequence. Increasing the emphasis produces clusters that are more spatially fragmented but follow the optimal extraction sequence more closely.
[0135] Once the clusters have been selected, they may be ordered in time. The clusters are selected based on a known algorithm of fuzzy clustering, such as J C Bezdek, R H Hathaway, M J Sabin, W T Tucker. “Convergence Theory for Fuzzy c-means: Counterexamples and Repairs”. IEEE Trans. Systems, Man, and Cybernetics 17 (1987) pp 873-877. Fuzzy clustering is a clustering routine that tries to minimise distances of data points from a cluster centre. In this inventive aspect, the cluster uses a four-dimensional space; (x, y, z, v), where x, y and z give spatial coordinates or references, and ‘v’ is a variable for any one or a combination of time, value, grade, ore type, time or a period of time, or any other desirable factor or attribute. Other factors to control are cluster size (in terms of ore mass, rock mass, rock volume, $value, average grade, homogeneity of grade/value), and cluster shape (in terms of irregularity of boundary, sphericalness, and connectivity). In one specific embodiment, ‘v’ represents ore type. In another embodiment, clusters may be ordered in time by accounting for ‘v’ as representing clusters according to their time centres.
[0136] There is also the alternative embodiment of controlling the sizes of the clusters and therefore the sizes of the pushbacks. “Size” may mean rock tonnage, ore tonnage, total value, among other things. In this aspect, there is provided a fuzzy clustering algorithm or method, which in operation serves to, where if a pushback is to begin, its corresponding cluster may be reduced in size by reassigning blocks according to their probability of belonging to other clusters.
[0137] There is also another embodiment where there is an algorithm or method that is a form of ‘crisp’, as opposed to fuzzy, clustering, specially tailored for the particular type of size control and time ordering that are found in mining applications. This ‘crisp’ clustering is based on a method of slowly growing clusters while continually shuffling the blocks between clusters to improve cluster quality.
[0000] 7.2 Fuzzy Clustering; Alternative 2 (Propagation of Clusters)
[0138] Having disclosed clustering, above, another related aspect of invention is to then propagate these clusters in a time ordered way without using intersections, to produce the pushbacks.
[0139] Referring to FIG. 10 , a mine site 1001 is schematically represented, in which there is an ore body of 3 sections, 1002 , 1003 , and 1004 .
[0140] Inverted cones are then propagated upwards in a time order, as represented in FIG. 10 , by lines 1005 and 1006 for cone 1 . That is, the earliest cluster (in time) is propagated upwards to form an inverted cone. Next, the second earliest cluster is propagated upwards, as represented in FIG. 10 by lines 1007 and 1008 (dotted) for cone 2 , and lines 1009 and 1010 (dotted) for cone 3 . Any blocks that are already assigned to the first cone are not included in the second cone. This is represented in FIG. 10 by the area between lines 1008 and 1005 . This area remains a part of cone 1 according to this inventive aspect. Again, in FIG. 10 , the area between lines 1010 and 1007 remains a part of cone 2 , and not any subsequent cone. This method is applied to any subsequent cones. Likewise, any blocks assigned to the second cone are not included in any subsequent cones. These propagated cones or parts of cones form the pushbacks.
[0000] 7.3 Fuzzy Clustering; Alternative 3 (Feedback Loop of Pushback Design)
[0141] In this related aspect, there is a process loop of clustering, propagating to find pushbacks, valuing relatively quickly, and then feeding this information back into the choice of clustering parameters.
[0142] This secondary clustering, propagation, and NPV valuation is relatively rapid, and the intention is that there would be an iterative evaluation of the result, either by computer or user, and accordingly the emphasis for the 4th coordinate can be selected, the propagation and valuation can be considered and performed, and the pushbacks for mineability can also be considered and reviewed. If the result is considered too fragmented, the emphasis of the 4th coordinate may be reduced. If the NPV from the valuation is too low, the emphasis of the 4th coordinate may be increased.
[0143] Referring to FIG. 11 a, there is illustrated in plan view a two dimensional slice of a mine site. In the example there are 15 blocks, but the number of blocks may be any number. In this example, blocks have been numbered to correspond with extraction time, where 1 is earliest extraction, and 15 is late extraction time. In the example illustrated, the numbers indicate relatively optimal extraction ordering.
[0144] In accordance with the aspect disclosed above, FIG. 11 b illustrates an example of the result of clustering where there is a relatively high fudge factor and relatively high emphasis on time. Cluster number 1 is seen to be fragmented, has a relatively high NPV but is not considered mineable.
[0145] In accordance with the aspect disclosed above, FIG. 11 c illustrates an example of the result of clustering where there is a lower emphasis on time, as compared to FIG. 11 b. The result illustrated is that both clusters number one and two are connected, and ‘rounded’, and although they have a slightly lower NPV, the clusters are considered mineable.
[0000] 8. Aggregation of Precedence Constraints
[0146] An approach in accordance with a first aspect of invention is to aggregate the precedence constraints as follows:
max ∑ i v i x i
s . t . n i x i ≤ ∑ j ∈ P ( i ) x j x i ∈ { 0 , 1 } ∀ i
where n i = P ( i ) equation 3
[0147] In this first aspect approach, the number of constraints is reduced to one for every block below the surface (there are no precedence constraints for the blocks on the top bench of the pit). In this case each constraint enforces the rule that a block can only be extracted if all of its predecessor blocks are extracted. However, the total unimodularity property of the exact (disaggregated) formulation is not preserved in this first approach formulation. Hence, the integrality constraints on the decision variables must be enforced. Equation 3 manifests therefore as an integer program, and must be solved using the method of branch-and-bound, rather than the Simplex method. This solution method takes a relatively long time in terms of computation time and can also require a relatively large amount of memory for storage of the decision tree. In particular, obtaining the truly optimal solution (as opposed to a solution within a specified percentage of the optimal solution) may take a relatively long time.
[0148] When the aggregated formulation (equation 3) is LP-relaxed and solved in CPLEX, the decision variables may take fractional values, and the outcome is expressed in equation 4 following:
max ∑ i v i x i
s . t . n i x i ≤ ∑ j ∈ P ( i ) x j 0 ≤ x_i ≤ 1 ∀ i
where n i = P ( i ) equation 4
[0149] Consider the case of a relatively small first example of a mine (16,049 blocks) that is provided as an example with the Whittle software package (by Whittle Pty Ltd. www.whittle.com.au). FIG. 12 shows the view from above of a comparison of the optimal solutions found by the exact formulation (equation 2) and the LP relaxation of the aggregated formulation (equation 4). The blocks 10 are those that are set to 1 by both the exact formulation (equation 2) and the aggregated formulation (equation 3). The blocks 11 around the outside of this pit are those blocks which are included (set to 1) in the ultimate pit found by the exact formulation (equation 2), but are not included (set to 0) in the solution found by the LP relaxation of the aggregated formulation (equation 4). It is evident that there are a number of blocks that are included in the true ultimate pit that are not included by the LP relaxation of the aggregated formulation (equation 4). The blocks 12 are waste.
[0150] A comparison of a vertical cross-section of the pit design using the exact formulation (equation 2) and the LP relaxation of the aggregated formulation (equation 4) for this first mine example is illustrated in FIG. 13 when compared with FIG. 14 .
[0151] FIG. 13 shows a plane through the example pit from the view of the solution using the exact formulation (equation 2). The area 20 is the ultimate pit and the area 21 is waste. Referring to Table 1, below, the total value of this pit is found to be $1.43885E+09, and CPLEX requires 29.042 seconds to obtain this solution.
[0152] FIG. 14 shows the equivalent view when the LP relaxation of the aggregated formulation (equation 4) for the ultimate pit is used. The area 20 is blocks set to 1, area 21 is waste (blocks set to 0) and area 22 is material which may be further interrogated in order to decide whether it is included (or not) in the ultimate pit (set to a value between 0 and 1). The total value of this pit is found to be $1.54268E+09, and found in a CPU time of 0.992 seconds. Note that the solution of the aggregated formulation (equation 3) (where integrality constraints are imposed on the decision variables) gives a total value of the ultimate pit to be $1.43591E+09 (using a branch-and-bound stopping criteria of 1% from optimal), which is similar to the value as that given by equation 2, and a CPU time of 1675.18 seconds was required to obtain this solution.
TABLE 1 Summary of results for first mine example. First example mine Total Blocks 16049 Formulation Exact LG (equation 2) Total Number of Precedence 264859 Constraints Total Value 1.43885E+09 CPU Time (Seconds) 29.402 No. Blocks in Ultimate Pit 9402 % of Total Blocks 58.58 Aggregated LG (equation 3) (IP) Total Number of Precedence 14077 Constraints Total Value 1.43591E+09 CPU Time (Seconds) 1675.18 No. Blocks in Ultimate Pit 9670 % of Total Blocks 60.25 Final Gap (from optimal) 0.46% Aggregated LG (equation 4) (LP relaxation) Total Number of Precedence 14077 Constraints Total Value 1.54268E+09 CPU Time (Seconds) 0.992 No. Blocks In Ultimate Pit 7949 % of Total Blocks 49.53 Aggregated LG (Cutting Plane) (equation 9, below) (LP relaxation + add single block constraints) Total Number of Precedence 34819 Constraints Total Value 1.43885E+09 CPU Time (Seconds) 976.565 No. Blocks In Ultimate Pit 9402 % of Total Blocks 58.58 Number of Iterations 9
[0153] It is evident that CPLEX, when using this relaxed aggregated formulation for the problem, provides a relatively higher valued ultimate pit to be found, but does so in a relatively shorter time. This relatively higher value results, in part, from a relaxation of the predecessor constraints, thus allowing a fraction of a block to be taken even when all of its predecessor blocks have not been taken.
[0154] By way of illustration of the reason for finding a relatively higher pit value using equation 4, consider the situation shown in FIG. 15 . The number within each block represents the value assigned to the decision variable (x i ) for that block by the LP relaxation of the aggregated formulation (equation 4).
[0155] In the case illustrated in FIG. 15 , Blocks 2 and 3 are predecessors of Block 1 . Block 1 is represented by x 1 , block 2 by x 2 and block 3 by x 3 in the equations below. In the exact formulation (equation 2), the constraints for this situation illustrated are
x 1 ≦x 2
x 1 ≦x 3 equation 5
[0156] The solution given (x1=0.5, x2=0, x3=1) is infeasible for the exact formulation (equation 2), since
x 1 =0.5>x 2 =0 equation 6
[0157] However, in the LP relaxation of the aggregated formulation (equation 4), the relevant constraint is
2 x 1 ≦x 2 +x 3 equation 7
[0158] In this case the solution from FIG. 15 is considered feasible (since 2×0.5=1<=0+1=1).
2×½≦0+1 equation 8
[0159] Hence if Blocks 1 and 3 were ore blocks and had positive value, while Block 2 was a waste block with negative value, the LP relaxation of the aggregated formulation (equation 4) can take all of Block 3 and 0.5 of Block 1 without incurring the penalty of taking the negative valued Block 2 . Hence the aggregated formulation (equation 4) can take fractions of positive blocks that otherwise would not have been taken in the exact formulation (equation 2). This leads to a solution of greater value than in the disaggregated case.
[0000] 9. Cutting Plane Method
[0160] The LP relaxation of the aggregated formulation (equation 4) can be modified to overcome this solution of artificially greater value. The result is equation 9 below, namely:
max ∑ i v i x i
s . t . n i x i ≤ ∑ j ∈ P ( i ) x j 0 ≤ x_i ≤ 1 ∀ i
where n i = P ( i )
loop over all arcs
{ if i → j , and x i > x j in solution , then add the constraint xi ≤ xj } equation 9
[0161] This approach as expressed by equation 9 is considered a second aspect of invention termed a ‘cutting plane method’. In this second aspect, an initial (reduced) problem is solved to give an upper bound on the optimal value, and then any constraints from the overall (Master) problem that are violated by this solution are added, and the problem is re-solved. This is repeated until substantially no constraints from the Master problem are found to be violated. In this second aspect, the linear program for the aggregated formulation (equation 4) is run and a solution, call it {circumflex over (x)} is obtained. Each element of the vector {circumflex over (x)} represents the value (possibly fractional) assigned to each block. Within {circumflex over (x)} there will be instances of pairs of individual blocks where the constraint that the successor block cannot be taken until the entire predecessor block has been taken (from the exact formulation) is violated. For example, in FIG. 15 , the constraint in the exact formulation that block 1 is assigned an i value of 0.5 and j is assigned a value of 0
x 1 ≦x 2 equation 10
[0162] is violated, since x1=0.5 and x2=0.
[0163] Thus, in the case of FIG. 15 , i has a value greater than j and the constraint is added and the solution re-run. The result will be the violation posed by FIG. 15 as far as blocks 1 and 2 , will be removed. Some individual block constraints can be added to the LP relaxation of the aggregated formulation (equation 4) to make it feasible for the ultimate pit problem. It is possible to perform the following iteration.
[0164] For each element of {circumflex over (x)}, compare its value with that of each of its predecessor blocks in turn. Whenever there is a situation where the successor block has a greater value than the predecessor block, add the relative single block constraint to the formulation. For example, in the situation from FIG. 15 , the constraint
x 1 ≦x 2
will be added to the LP relaxation of the aggregated formulation (equation 4). After checking the relationship for all pairs of predecessors, re-solve the problem, subject to the aggregated constraints as well as the added single block precedence constraints. Again, the solution may be infeasible, so the process may have to be repeated. This process should be repeated until the step of checking single block dependencies reveals that substantially no single block precedence relationships are violated. The solution at this point has been found to be the same as the optimal solution, found by solving the exact formulation (equation 2).
[0165] It is considered that the number of constraints needed to obtain the solution using this second aspect approach is significantly less than the number used in the disaggregated formulation. Since the initial aggregated solution gives a reasonable approximation to the ultimate pit, it has been found that only a small percentage of the total number of single block precedence constraints for the problem should need to be added to the formulation. In this way, the computational requirement in terms of memory (storage and manipulation of the constraint matrix) to find the optimal solution should be significantly reduced. However, the cost of this approach is that the process of checking and identification of violated constraints will require more time than the prior art method of equation 2. When equation 9 is applied to the first mine example referred to above, this second approach found the total value of the pit to be $1.43885E+09, the same as the solution to the problem using the disaggregated formulation (equation 2). The computation time required to achieve this second approach was 976.565 seconds.
[0166] A brief comparison of these two methods for the ultimate pit problem at the first example mine is given in Table 1, above.
[0000] 10. Aggregation—Cutting Plane and Added Blocks and Arc Constraints
[0167] It is evident that the trade off between the prior art approach and the approaches of the first and second aspects is time against memory, as illustrated in Table 1, above). The exact formulation (equation 2) finds the optimal solution in 29.402 seconds, while the cutting plane formulation (equation 9) takes 976.565 seconds to find the optimal solution. This is due, in part, to the fact that the cutting plane formulation re-solves a large LP a number of times in the process of solving the problem. In addition, the process of searching through and checking the entire arcs file (which is completed as a part of each iteration) takes a significant amount of time. However, the exact formulation (equation 2) solves a model with 264,859 precedence constraints (requiring a significant amount of memory), compared with 34,819 precedence constraints in the cutting plane formulation (equation 5). This is a decrease of 87%. It is expected that the number of constraints in the model is proportional to the memory required to store and solve the problem, in particular, to perform the inversion on the final constraint matrix once the optimal solution has been found. Thus, advantageously, a solution of the cutting plane formulation (equation 9) may be possible in cases where CPLEX runs out of memory when trying to solve the exact formulation (equation 2).
[0168] In a second example mine, which has 38,612 blocks, the same approach was taken to that above, with similar results, as shown in Table 2.
TABLE 2 Summary of results for second mine example. Example Mine 2 Total Blocks 38612 Formulation Exact LG (equation 2) Total Number of Precedence 1045428 Constraints Total Value 1.87064e+009 CPU Time (Seconds) 223.762 No. Blocks in Ultimate Pit 33339 % of Total Blocks 86.34 Aggregated LG (Cutting Plane) (equation 9) (LP relaxation + add arc or single block constraints) Total Number of Precedence 159832 Constraints Total Value 1.87064E+09 CPU Time (Seconds) 12354.3 No. Blocks in Ultimate Pit 33339 % of Total Blocks 86.34 Number of Iterations 6
[0169] In particular, referring to Table 2 above, the exact formulation (equation 2) contains 1,045,428 constraints, while the final model following implementation of the cutting plane algorithm (equation 9) requires only 159,832 constraints. However, the cutting plane method (equation 9) takes 12,354.3 seconds to find the solution, while the exact formulation (equation 2) requires 223.762 seconds of CPU time.
[0170] Further testing of the alternative mixed integer program approaches to the pit design was carried out on a third mine example, as detailed in Table 3 below. The block model for the third mine example contains 198,917 blocks.
[0171] Initially, the exact formulation (equation 2) was trailed. This resulted in CPLEX attempting to solve a linear program with 3,526,057 single block constraints. The size of this constraint matrix caused CPLEX to run out of memory when trying to apply the dual simplex algorithm to solve the problem. Thus, the exact solution to the pit design in the case of this third mine example is unable to be determined by this approach.
[0172] The aggregate formulation (equation 3) was next trailed. This resulted in 188,082 constraints, a value of $3.34125E+09, and a CPU time of 33298.5 seconds.
[0173] The next trail was to run the LP relaxation of the aggregated formulation (equation 4). It is expected that the solution to this problem will give an upper bound on the optimal value of the ultimate pit, as was described above. This is due to the fact that CPLEX includes fractions of blocks without necessarily taking their entire precedence set. In this trail, the model had 188,082 constraints. The optimal solution was found to have a value of $3.40296E+09, and this was found in 12.989 seconds of CPU time.
TABLE 3 Summary of results for third mine example. example Mine 3 Total Blocks 198917 Exact LG (equation 2) Total Number of Precedence 3526057 Constraints Total Value CPU Time (Seconds) out of memory No. Blocks in Ultimate Pit % of Total Blocks Aggregated LG (equation 3) (IP) Total Number of Precedence 168082 Constraints Total Value 3.34125E+09 CPU Time (Seconds) 33298.5 No. Blocks in Ultimate Pit 97221 % of Total Blocks 48.88 Final Gap (from optimal) 0.99% Aggregated LG (equation 4) (LP relaxation) Total Number of Precedence 188082 Constraints Total Value 3.40296E+09 CPU Time (Seconds) 12.989 No. Blocks in Ultimate Pit 91522 % of Total Blocks 46.01 Aggregated LG (Cutting Plane) (equation 9) (LP relaxation + add single block or arc constraints) Total Number of Precedence 285598 Constraints Total Value 3.37223E+09 CPU Time (Seconds) 19703.8 No. Blocks in Ultimate Pit 98845 % of Total Blocks 49.69 Number of Iterations 4
[0174] The cutting plane formulation (equation 9) was also trailed on this example third mine. This is the method where the solution to the LP relaxation of the aggregated formulation is used as a starting solution, and then violated single block constraints are added to the model and then again resolved. This process is repeated until no more single block constraints are violated, and thus the solution is similar to that for the exact formulation. The solution to this equation 9 is considered to be the correct solution to the problem. When equation 9 was run, it was found that CPLEX was able to handle the size of the problem, and the exact ultimate pit was found. The solution contained 285,598 constraints, a reduction of 92% on the exact formulation. The optimal value of the pit design was found to be $3.37223E+09, and the CPU time required to find this solution was 19703.8 seconds.
[0175] Thus the cutting plane algorithm (equation 9) has been found to provide an improved solution within the memory limits of a practical implementation of the present invention, using computers and/or computer modelling, where the exact formulation (equation 2) could not. Again, the saving in memory is offset by a longer computation time.
[0176] As in the case of the first mine example, a comparison of a vertical cross section of the solution to the ultimate pit problem using the cutting plane formulation and the LP relaxation of the aggregated formulation for the third mine example is illustrated in the Figures. FIGS. 16 and 18 show a plane view through the pit using the cutting plane formulation (equation 9). The area 20 is the ultimate pit and the area 21 is waste. FIGS. 17 and 19 , on the other hand, show the same view, but for the LP relaxation of the aggregated (equation 4). Again, areas 20 are the pit and areas 21 are waste. Again, it is evident that the LP relaxation of the aggregated (equation 4) takes fractions of blocks that are infeasible for the exact formulation.
[0177] This result is considered to confirm that solution of the cutting plane formulation (equation 9) may be possible in cases where CPLEX runs out of memory when trying to solve the exact formulation (equation 2).
[0178] A summary of the results for the third mine example is found in Table 3.
[0000] 11. Variations on the Cutting Plane Method
[0000] 11.1 First Variation
[0179] Since it was found that adding all violated constraints at once causes additional loading on the cutting plane approach (equation 9), due to the very large number of constraints added by the first iteration, one variation of the cutting plane method is to add the constraints incrementally. Initially, the effect of adding the most violated constraints first, and then re-solving the formulation was investigated. This method was thoroughly tested on the first mine example. The approach taken was as follows. At each iteration of the method, a lower bound on the size of the violation of the single block constraint was specified (e.g. 0.5, 0.6, . . . ). For example, FIG. 15 illustrates violations for each block. In this example FIG. 15 , the violation=x i −x j , and so the ‘size’ of the violation is 0.5−0=0.5. Constraints that were violated by an amount greater than this tolerance were added to the formulation, and the problem was re-solved. However, using this approach the optimisation process completed before the optimal solution was found. This occurs because this method of adding constraints does not identify and add all single block constraints that are violated, only those that are violated by more than a certain amount. In this way, not all of the necessary single block constraints are added to the formulation, and the truly optimal solution is not reached. To alleviate this problem, violation(s) greater than a selected lower bound is added to at least the first iteration. This approach enables an optimal solution is still obtained.
[0000] 11.2 Second Variation
[0180] Another approach is to add the most violated constraints, but to decrease the amount of violation required at each iteration until a certain number of constraints have been added. For example, it may be designated that a minimum of 5000 constraints should be added at each iteration. Say the initial violation parameter is set to 0.6 (that is, only single block constraints that are violated by 0.6 or more are added to the formulation). It may be the case that 1200 constraints are added. Then, before re-solving the formulation, the violation parameter could be decreased to 0.5. This may result in a further 3000 constraints being added to the model. Since there are still less than 5000 constraints added, the violation parameter is further decreased to 0.4, and more single block constraints are added. This may result in 2000 constraints being added to the formulation, and the problem is now re-solved since the minimum of 5000 constraints has been reached. The process is then repeated until the optimal solution is obtained.
[0000] 11.3 Third Variation
[0181] Alternatively, the tolerance could be reduced on a smaller incremental level (say 0.01 at a time instead of 0.1) in an attempt to reduce the size of the overshoot on the number of constraints added compared with the prescribed minimum number of constraints.
[0000] 11.4 Fourth Variation
[0182] A further alternative is simply to add a specified number of constraints to the model before the formulation is re-solved. In any approach where a minimum number of constraints are added, the determination of the appropriate number of constraints to add at each iteration is a non-trivial matter. This element of the problem may itself require optimisation. It is expected that the maximum size of the problem that is able to be stored in memory and handled by CPLEX will affect this value. Consideration of this fact may allow a test to be built in to the program for solving the ultimate pit problem. The form of the test procedure could proceed as follows. If the size of the constraint matrix following the first iteration is less than the maximum size able to be solved by CPLEX, (with a margin to allow more constraints to be added in subsequent iterations based on the general proportion of constraints added after the initial loop—it appears that approximately 90% of the constraints that are required are added in the first loop), take the path of adding all violated constraints. If the size of the constraint matrix following the first iteration is greater than the maximum able to be solved, restart the iteration process using one of the alternative constraint-adding processes described above.
[0183] The approaches described above were tested on the first mine example above. In this case, the approach that performed the best was to add single block constraints that were violated by more than 0.6 in the first 5 loops, and in subsequent loops, add all violated constraints. This approach found the optimal solution in 2152.24 seconds. This was significantly longer than the standard cutting plane procedure, which required 976.565 seconds (compare with statement below).
[0000] 11.5 Fifth Variation
[0184] Another approach for adding constraints incrementally takes advantage of the specific geometry of the mine. In this case, a vector containing the z coordinate (or “height”) for each block is stored. Using this information, violated single block constraints are added from the largest z coordinate (corresponding to the top of the pit) down, decreasing by block height, in each loop. The constraint adding process stops either once a specified number of constraints have been added, or after a specified number of z coordinates have been descended. By adding violated single block constraints from the largest z coordinate down, it is hoped that the subsequent optimisation steps will force more single block constraints from lower in the pit to be satisfied before they need to be explicitly added to the formulation in a cutting plane iteration. That is, once decisions regarding the uppermost benches of the pit have been made, the precedence constraints within the formulation could force these decisions to propagate down the pit. Subsequently, less single block constraints may need to be added through the cutting plane iterations before the problem is solved to optimality.
[0185] This approach was particularly effective in the case of the third mine example. The optimal solution to the problem was found in 2664.11 seconds when constraints were added from the top z coordinate down in each iteration, with ten z coordinates descended in each iteration. This compares very favourably with the standard cutting plane formulation, which requires 19,703.8 seconds to find the optimal solution.
[0186] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth.
[0187] The present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures. For example, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface to secure wooden parts together, in the environment of fastening wooden parts, a nail and a screw are equivalent structures.
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The present invention relates to the field of extracting resource(s) from a particular location. In particular, the present invention relates to the planning, design and processing related to a mine location in a manner based on enhancing the extraction of material considered of value, relative to the effort and 1 or time in extracting that material. The present application discloses, amongst other things, a method of and apparatus for determining slope constraints, determining a cluster of material, determining characteristics of a selected portion of material, analysing a selected volume of material, propagating dusters, forming clusters, mine design, aggregation of blocks into collections or clusters, splitting of waste and ore in clumps, determining a selected group of blocks to be mined, clump ordering and identifying clusters for pushback design.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a novel composition of organosilane derivatized long-chain olefinic compounds prepared by the hydrosilylation reaction of a substituted halosilane and a substituted long-chain olefinic compound. More particularly, though not exclusively, this invention relates both to novel compositions of organosilane derivatized fatty compounds and to processes for making those compositions. The invention is also directed to organosilanol derivatized long-chain olefinic compounds that are surface active agents having utility in coatings, adhesives and inks to improve and enhance the general application properties of these formulations.
2. Description of the Prior Art
A wide variety of additives used in such formulations as in coatings, inks, and adhesives contain volatile organic compounds (VOCs). A major utility of these additives includes as surface active agents, i.e., as surfactants, dispersants, corrosion inhibitors, and as defoamers. However, the VOCs in these formulations are released to the atmosphere during their use and cause undesirable side effects. As a result, Congress has passed Clean Air Act of 1990 forcing the coating manufacturers to develop low to no VOC formulations. Although water based formulations for the above mentioned applications are being developed, there is still a need for more cost effective multi-functional surface active agents that are suitable for forming stable emulsions of these formulations.
One approach that is used in the prior art which is relevant to this invention is hydrosilylation of a variety of compounds to form surface active agents. Hydrosilylation involves a reaction of a Si--H containing compound with an olefinic compound to form a organosilane compound. A number of so formed organosilane compounds feature surface active properties. Examples of such compositions are described in Eur. Pat. Appl. No. 659,837; Eur. Pat. Appl. No. 585,044; and U.S. Pat. No. 5,247,044; which are hereby incorporated herein by reference in their entirety.
There are also extensive literature references on surfactant compositions based on siloxane-polyether compositions particularly useful in polyurethane foam applications and for forming stable emulsions. Specific examples of such surfactant compositions are described in Eur. Pat. Appl. No. 520,392; Eur. Pat. Appl. No. 459,705; East German DD 282,692 and 282,014; Eur. Pat. Appl. No. 378,370; German patent DE 3,913,485; and Eur. Pat. Appl. No. 314,903; which are hereby incorporated herein by reference in their entirety.
A few references also disclose synthesis of organopolysiloxanes by a hydrosilylation reaction using a platinum catalyst. Examples of such hydrosilylation reactions are described in U.S. Pat. No. 4,520,160; U.S. Pat. No. 4,150,048; and Ger. Offen. DE 2,364,887; which are hereby incorporated herein by reference in their entirety.
A major drawback of these references is that they all involve the reaction of complicated polymeric siloxanes, which are either expensive and are not readily available. In addition, none of the references discussed above utilizes simple, cost effective, and readily available monomeric Si--H containing compounds. Furthermore, none of the references mentioned above teaches a simple hydrosilylation reaction involving a cheap, readily available halosilane with a long-chain olefinic compound, and subsequently hydrolyzing these products in an aqueous phase to form instantly the surface active agents. Most importantly, none of the references mentioned above discloses preparation of stable organosilanol compounds having excellent surfactant properties.
Therefore, it is an object of this invention to provide novel compositions derived from simple halosilanes containing Si--H bonds by the reaction of the halosilanes with a wide variety of long-chain olefinic compounds. An additional objective of this invention is to provide hitherto unknown novel organosilanediol and organosilanol compositions, which spontaneously emulsify and form stable emulsions by a simple aqueous hydrolysis of the novel halosilane compositions. Yet another objective of this invention is to provide a process for the preparation of the novel halosilane and silanol compositions. It is also an objective of this invention to provide a variety of utilities for these novel compositions. Such utilities include applications as dispersants, defoamers, gloss enhancers, crosslinkers, surfactants, adhesion promoters, and as anti-corrosive additives thus enhancing the general application and performance properties of paints, coatings, adhesives and inks yet contributing zero VOCs to these formulations. The compositions of the present invention have no precedence in the prior art.
Prior Art
The following references are disclosed as background prior art.
U.S. Pat. No. 4,150,048 discloses a process for making novel compositions of nonhydrolyzable siloxane block copolymers of organosiloxanes and organic ethers by the reaction of organic ethers having olefinic end groups with organohydrosiloxanes.
U.S. Pat. No. 4,520,160 discloses a method for making organopolysiloxane emulsifier compositions by a hydrosilylation reaction.
U.S. Pat. No. 5,247,044 teaches a synthesis of silicon polyether copolymers from ring opening polymerization of epoxides in the presence of Si--H containing compounds.
Eur. Pat. Appln. No. 314,903 discloses a process for the preparation of siloxane-oxyalkylene copolymers by a solventless process via hydrosilylation of oxyethylene rich polyethers.
Eur. Pat. Appln. No. 378,370 describes a process for making silicon-containing polymer particles useful for preparing uniform, crosslinked silicone rubber particles.
Eur. Pat. Appln. No. 459,705 discloses a novel surface active organopolysiloxane compositions obtained by hydrosilylation procedure for forming water-in-oil emulsions for emulsifying oils.
Eur. Pat. Appln. No. 520,392 teaches an improved surfactant composition for flexible polyurethane foam.
Eur. Pat. Appln. No. 585,044 discloses a novel polysiloxane polyether useful as a silicone surface active agent.
Eur. Pat. Appln. No. 659,837 describes an improved process for the preparation of siloxane-oxyalkylene block copolymer utilizing hydrosilylation reaction with a phenyl ether.
Ger. Offen. DE 2,364,887 discloses hydroxyalkyl siloxanes as foam stabilizers.
German patent DE 3,913,485 discloses surface-active N-(silylpropyl)- perfluoroalkanesulfonamides which were prepared by condensation and hydrosilylation procedure.
Ger. (East) DD 282,692 and 282,014 disclose siloxanylalkenol useful as surfactants synthesized by hydrosilylation procedure.
J. Fluorine Chem., (1991), Vol. 55(l), (pp 79-83) describes a synthesis of new silanes derived from non-ionic F-alkylated surfactants by hydrosilylation procedure.
Appl. Organomet. Chem., (1992), Vol. 6(8), (pp 701-8) discloses novel nonionic siloxane surfactants which were obtained by the hydrosilylation of butynediol-oligo(oxyethylenes) with polysiloxanes.
Second International Symposium on Film Formation, Chicago, Ill. (1995) discusses about the Clean Air Act of 1990.
Polymeric Materials Science and Engineering, (1995), Vol. 73, (pp 366) also discusses about the Clean Air Act of 1990.
All of the references described herein are incorporated herein by reference in their entirety.
SUMMARY OF THE INVENTION
Surprisingly, it has now been found that an organosilane derivatized long-chain olefinic compound can be readily formed by a simple one-step reaction of a long-chain olefinic compound with a Si--H containing moiety. The organosilane derivatives so formed are highly surface active and spontaneously hydrolyze when contacted with water to form stable emulsions which have excellent surfactant properties. This invention thus provides hitherto unknown, stable, novel organosilanediol and organosilanol compositions, with properties unattainable by prior art approaches. This invention also provides novel processes whereby such novel compositions of matter are prepared with inherent capability to form stable emulsions. Preferred long-chain olefinic compounds of this invention are olefinic fatty acid esters or oils.
More particularly, the organosilane derivatized compounds of the present invention are derived from a long-chain olefinic compound of the formula:
R--R.sub.8
wherein R has the formula: ##STR1## wherein (a) R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 , and R 7 are the same or different and are each independently selected from the group consisting of hydrogen, alkoxy group having 1 to 10 carbon atoms, phenyl and substituted phenyl, tolyl and substituted tolyl, alkyl and fluoroalkyl groups having the formula C n H x F y , where n is an integer from 1 to 10, x and y are integers from 0 to 2n+1, and the sum of x and y is 2n+1; (b) R 8 is selected from the group consisting of --COOR', --CN, --CONR"R'",--CH 2 NR"R'", and suitable salts thereof, where R', R", and R'" are the same or different and are independently selected from the group consisting of phenyl and substituted phenyl, tolyl and substituted tolyl, benzyl and substituted benzyl, a linear or branched alkenyl group having 2 to 10 carbon atoms, a linear or branched alkyl and fluoroalkyl group having the formula C n H x F y , where n is an integer from 1 to 10, x and y are integers from 0 to 2n+1, and the sum of x and y is 2n+1, and R' can also be a multifunctional moiety having the structure: ##STR2## where R 9 and R 10 are the same and may be the same as carboxylated R or different and are independently selected from the group consisting of a substituted or unsubstituted, saturated or unsaturated fatty acid chain, acrylic and substituted acrylic, and a linear or branched alkyl and alkenyl carboxylic acid moiety having 2 to 20 carbon atoms; (c) X a and X b are the same or different and are selected from the group consisting of Br, Cl, I, hydroxy, alkoxy group having 1 to 10 carbon atoms, a mixed polyalkyleneoxy group having 2 to 4 carbon atoms, polyethyleneoxy, polypropyleneoxy, phenoxy, benzoxy, and substituted polyaryloxy group having 7 to 20 carbon atoms; (d) Y is same as X a or X b , or an aliphatic or an aromatic moiety having 1 to 20 carbon atoms; and (e) a, b, c, and d are integers, where a ranges from about 0 to about 20, b ranges from about 0 to about 4, c ranges from about 0 to about 4, and d ranges from about 0 to about 20.
This invention is also based in part on the use of the organosilanol derivatized long-chain olefinic compounds as surfactants or defoamers in the preparation of paint formulations for a variety of coating applications. The emulsions formed from the organosilanol derivatized long-chain olefinic compounds can be used in water systems as wetting agents, and emulsifiers. They are particularly suitable for dispersing pigments or anti-corrosive additive materials in paints or inks. These materials are also suitable as surfactants in emulsion polymerization.
DETAILED DESCRIPTION OF THE INVENTION
Surprisingly, it has now been found that an organosilane derivatized long-chain olefinic compound can be readily formed by a simple one-step reaction of a long-chain olefinic compound with a Si--H containing moiety. The organosilane derivatives so formed are highly surface active and spontaneously hydrolyze when contacted with water to form stable emulsions which have excellent surfactant properties. This invention thus provides hitherto unknown, stable, novel organosilanediol and organosilanol compositions, with properties unattainable by prior art approaches. This invention also provides novel processes whereby such novel compositions of matter are prepared with inherent capability to form stable emulsions. Preferred long-chain olefinic compounds of this invention are olefinic fatty acid esters or oils.
More particularly, the organosilane derivatized compounds of the present invention are derived from a long-chain olefinic compound of the formula:
R--R.sub.8
wherein R has the formula: ##STR3## wherein (a) R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 , and R 7 are the same or different and are each independently selected from the group consisting of hydrogen, alkoxy group having 1 to 10 carbon atoms, phenyl and substituted phenyl, tolyl and substituted tolyl, alkyl and fluoroalkyl group having the formula C n H x F y , where n is an integer from 1 to 10, x and y are integers from 0 to 2n+1, and the sum of x and y is 2n+1; (b) R 8 is selected from the group consisting of --COOR', --CN, --CONR"R'", --CH 2 NR"R'", and suitable salts thereof, where R', R", and R'" are the same or different and are independently selected from the group consisting of phenyl and substituted phenyl, tolyl and substituted tolyl, benzyl and substituted benzyl, a linear or branched alkenyl group having 2 to 10 carbon atoms, a linear or branched alkyl and fluoroalkyl group having the formula C n H x F y , where n is an integer from 1 to 10, x and y are integers from 0 to 2n+1, and the sum of x and y is 2n+1, and R' can also be a multifunctional moiety having the structure: ##STR4## where R 9 and R 10 are the same and may be the same as carboxylated R or different and are independently selected from the group consisting of a substituted or unsubstituted, saturated or unsaturated fatty acid chain, acrylic and substituted acrylic, and a linear or branched alkyl and alkenyl carboxylic acid moiety having 2 to 20 carbon atoms; (c) X a and X b are the same or different and are selected from the group consisting of Br, Cl, I, hydroxy, alkoxy group having 1 to 10 carbon atoms, a mixed polyalkyleneoxy group having 2 to 4 carbon atoms, polyethyleneoxy, polypropyleneoxy, phenoxy, benzoxy, and substituted polyaryloxy group having 7 to 20 carbon atoms; (d) Y is same as X a X b , or an aliphatic or an aromatic moiety having 1 to 20 carbon atoms; and (e) a, b, c, and d are integers, where a ranges from about 0 to about 20, b ranges from about 0 to about 4, c ranges from about 0 to about 4, and d ranges from about 0 to about 20.
The long-chain olefinic compounds are preferably linear long-chain olefinic esters wherein R 8 is --COOR' and are unsubstituted. Accordingly, R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 , and R 7 in the above structure are hydrogen. In one of the preferred embodiments, the R' group in this structure is a multifunctional moiety having the structure: ##STR5## where R 9 and R 10 are as defined above. More preferably, R 9 and R 10 are same as the carboxylated long-chain olefinic group R or may be different and are independently selected from the group consisting of a substituted or unsubstituted saturated or unsaturated fatty acid chain.
The preferred long-chain olefinic esters are fatty oils. A variety of fatty oils having at least one olefinic bond in their fatty ester chain are suitable to form the organosilane derivative of the present invention. Representative examples of such fatty oils are cotton seed oil, sunflower oil, safflower oil, soybean oil, linseed oil, perilla oil, tung oil, Chinese melon oil, oiticica oil, rape seed oil, high erucic acid rape seed oil, crambe oil, vernonia oil, hemp oil, poppy seed oil, and cod-liver oil. The hydroxy fatty acids containing oils such as castor oil or lesquerella oil may also be employed provided that the hydroxy group is suitably protected. Thus, for example, dehydrated castor oil and/or modified or derivatized castor oil are particularly suitable for forming organosilane derivative of the present invention.
A wide variety of long-chain olefinic acids are suitable for the formation of organosilane derivatives of the present invention. Typical examples of such long-chain olefinic acids are eleostearic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, erucic acid, brassidic acid, nervonic acid, arachidonic acid, and undecylenic acid. In addition, as mentioned above in one of the preferred embodiments, the R' group is a multifunctional moiety of the structure described above. This multifunctional moiety is derived from a glycerol molecule often called triglycerides and most commonly present in all of the naturally occurring fatty esters including vegetable and animal derived fatty esters (i.e., triglycerides).
Preferred R 9 and R 10 groups in this multifunctional moiety could be either saturated or unsaturated long-chain acid groups and are derived from either naturally occurring fatty esters (i.e., triglycerides) or synthetic long-chain carboxylic acids. Illustrative examples of saturated long-chain carboxylic acids are n-hexanoic acid, n-heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melissic acid and the like. Similarly, illustrative examples of unsaturated carboxylic acids are acrylic acid, methacrylic acid, cinnamic acid, crotonic acid, isocrotonic acid, angelic acid, tiglic acid, eleostearic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, erucic acid, brassidic acid, nervonic acid, arachidonic acid, undecylenic acid, and the like. Various saturated and unsaturated dicarboxylic acids may also be used provided that one of the carboxylic groups in these acids is suitably protected. Illustrative examples of such dicarboxylic acids include maleic acid, fumaric acid, and the like.
In one of the preferred embodiments, the long-chain olefinic ester is derived from a fatty oil selected from the group consisting of tung oil, high erucic acid rape seed oil, and linseed oil. In this embodiment, the X a and X b groups on the silicon atom may be the same or different and are preferably selected from the group consisting of Cl, Br, I, hydroxy, an alkoxy group having 1 to 20 carbon atoms, a mixed polyalkyleneoxy group having 2 to 4 carbon atoms, polyethyleneoxy group of the formula CH 3 O(CH 2 --CH 2 O) n --, and polypropyleneoxy group of the formula CH 3 O(CH 2 --CH(CH 3 )O) n --, where n is an integer ranging from about 10 to about 250. The mixed polyalkyleneoxy groups may be formed from a mixture of glycols such as ethylene glycol, propylene glycol, 1,2-butylene glycol, and the like. The mixed glycol linkages may be in a random order or in blocks of one kind. An example of a mixed polyalkyleneoxy group includes polyethyleneoxy-propyleneoxy group of the formula, CH 3 O(CH 2 --CH 2 O) a --(CH 2 --CH(CH 3 )O) b --, where a and b are integers ranging from about 10 to about 250.
The Y group on the silicon atom is either an alkyl group having 1 to 4 carbon atoms or a polyethyleneoxy or a polypropyleneoxy group as described above. Most preferably, X a and X b groups are either chlorine, polyethyleneoxy, polypropyleneoxy, or a hydroxy group; and Y is an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, propyl or butyl group, or an aryl group such as phenyl or benzyl group, or a polyethyleneoxy group of a suitable molecular weight. The substituents X a , X b , and Y on silicon atom are selected in such a way that the hydrophilic/lipophilic balance (HLB) number of the resulting organosilane derivatized fatty ester is preferably in the range of from about 10 to about 18.
The HLB number referred to hereinabove is an empirical measure of the relative strengths of the hydrophilic and lipophilic parts of a surfactant molecule. Generally, the HLB number of a compound is calculated by the following equation: ##EQU1## where percent hydrophilic character of a molecule may be calculated as follows: ##EQU2## Thus, the HLB number scale runs from 0 to 20 in arbitrary units, wherein 0 represents a surfactant overwhelmingly lipophilic in character; and 20 a surfactant overwhelmingly hydrophilic in character. A description of HLB numbers may be found in "Paint Flow and Pigment Dispersion," T. C. Patton, (1964, John Wiley), pp 247-251, incorporated herein by reference in its entirety.
Therefore, it is possible to vary the HLB numbers by incorporating either polyethyleneoxy or polypropyleneoxy groups of varying molecular weights into the organosilane derivatized fatty esters of the present invention. This is particularly important because surfactants of varied HLB numbers can now be synthesized for different dispersant or surfactant applications.
The present invention also provides a novel, unique, and efficient process for preparing novel organosilane derivatized long-chain olefinic compounds of the present invention, which can be readily converted into compositions such as stable emulsions by simple hydrolysis techniques. Accordingly, the process comprises the steps of (a) subjecting a substituted long-chain olefinic compound to suitable hydrosilylation conditions in the presence of a Si--H containing moiety having at least one halogen substituent and a suitable catalyst for a sufficient period of time and under suitable conditions of temperature and pressure to form the corresponding hydrosilylated long-chain compound; and (b) subjecting said hydrosilylated compound to suitable hydrolysis conditions for a sufficient period of time and under suitable conditions of temperature and pressure to form the composition containing the organosilanol derivatized long-chain compound.
The starting material, i.e., the substituted long-chain olefinic compound has the formula: ##STR6## wherein R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 ,R 7 R 8 , a, b, c and d are as defined above. Preferably, the long-chain olefinic compound is a long-chain olefinic ester derived from a fatty oil selected from the group consisting of cotton seed oil, sunflower oil, safflower oil, soybean oil, linseed oil, perilla oil, tung oil, Chinese melon oil, oiticica oil, rape seed oil, high erucic acid rape seed oil, crambe oil, vernonia oil, modified or dehydrated castor oil, modified or dehydrated lesquerella oil, hemp oil, poppy seed oil, and cod-liver oil. As stated earlier, the oils containing the hydroxy fatty acid moieties may also be used as starting materials provided that the hydroxy group is suitably protected.
The long-chain olefinic ester may also be an olefinic ester derived from a fatty oil and preferably selected from the group consisting of eleostearic acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, erucic acid, brassidic acid, nervonic acid, arachidonic acid, and undecylenic acid. Most preferably, the long-chain olefinic ester is selected from the group consisting of high erucic acid rape seed oil, linseed oil, tung oil, and methyl ester of eleostearic acid.
Utilizing the substituted long-chain olefinic compound (Formula I), it is believed that the process proceeds as shown in Scheme I below: ##STR7##
The hydrosilylation of the olefinic compound can be carried out by reacting it with a wide variety of Si--H containing moieties. The Si--H containing moiety is typically an organosilane molecule having a general formula X a X b YSi--H, where X a ,X b , and Y are the same or different and are as defined above. Illustrative examples of such organosilane molecules are trichlorosilane, dichloromethylsilane, dibromomethylsilane, diiodomethylsilane, dichloroethylsilane, dichlorophenylsilane, dichlorobutylsilane, dichloromethoxysilane, chloro-methoxy-methylsilane, and the like. Preferably, the silane is a dichloroalkylsilane, where alkyl group contains 1 to 4 carbon atoms. The most preferred organosilane is dichloromethylsilane.
The hydrosilylation reaction is generally carried out by mixing the olefinic compound with a suitable organosilane compound as described above in the presence of a suitable catalyst. Optionally, a solvent may be employed for this reaction. Any solvent, polar or nonpolar aprotic with relatively high vapor pressure, that solubilizes the olefinic compound may be employed. Suitable solvents include toluene, hexane, cyclohexane, petroleum ether, methylene chloride, chloroform, acetonitrile, ethyl acetate, sulfolane, and the like. The solvent is generally not required when the olefinic compound is of low viscosity such as methyl ester of eleostearic acid.
Various catalysts that are effective for hydrosilylation reaction may be employed. Typically, catalysts derived from Group VIII transition metals are used for hydrosilylation reactions. Suitable Group VIII metal-containing catalysts are well known and include platinum-, palladium-, and rhodium-containing catalysts. Catalysts such as platinum on a carrier, for example, alumina or charcoal, finely divided platinum, and chloroplatinic acid are also suitable for carrying out hydrosilylation. Various other catalysts may also be employed for affecting the hydrosilylation reaction, which include nucleophilic (e.g., bases such as amines, phosphines, etc.), electrophilic (e.g., ZnCl 2 CuCl 2 , etc.), and other metal catalysts. A detailed description of the hydrosilylation catalysts may be found in "Comprehensive Handbook on Hydrosilylation," Ed. by B. Marciniec, (1992, Pergamon), pp 8-94, incorporated herein by reference in its entirety. Particularly useful and preferred catalyst is platinumdivinyltetramethyldisiloxane.
The amount of catalyst employed is any amount which would produce the desired end result. Generally, this amount would be in the range of from about 0.05 parts per million (ppm) to about 2000 ppm based on the starting long-chain olefinic compound.
The hydrosilylation reaction in step (a) can be carried out at suitable temperatures to affect the addition of Si--H bond to the olefinic bond of the long-chain olefinic compound. Typical reaction temperature ranges from about 25° C. to about 200° C. Preferably, the reaction is carried out at a temperature from about 40° C. to about 150° C. The pressure in this step (a) is not critical and can be sub-atmospheric, atmospheric or super-atmospheric.
The reaction times in step (a) will generally range from about 15 minutes to about 24 hours or longer and sometimes under an inert atmosphere such as nitrogen.
Using the procedure of step (a) outlined herein, the substituted long-chain olefinic compound undergoes hydrosilylation with Si--H containing moiety to form the corresponding organosilane derivatized long-chain olefinic compound of the Formula II in Scheme I, wherein R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 ,R 7 ,R 8 ,X a ,X.sub.b, Y, a, b, c, and d are as defined above.
The organosilane derivative as described hereinabove is hydrolyzed in step (b) to form compositions such as stable emulsions. The organosilane derivative undergoes spontaneous hydrolysis when contacted with water. The hydrolysis can be carried out under a variety of techniques well known in the art. Preferably, the hydrolysis is carried out in the presence of a suitable base when the organosilane derivative formed in step (a) contains a halogen substituent, i.e., when X a or X b is a halogen in the above structure.
The suitable base is any material which will function for the hydrolysis conditions and includes, without limitation, inorganic base such as a metal hydroxide, preferably an alkali metal hydroxide, an alkali metal carbonate, e.g., K 2 CO 3 ; an alkali metal alkoxide (an ionic organic base), such as NaOCH 3 , KOC(CH 3 ) 3 , etc.; an alkali metal organic salt (an ionic organic base) such as potassium acetate, etc.; and an amine (a non-ionic organic base) such as pyridine, or a tri-lower-alkylamine, e.g., tripropylamine, trimethylamine, and triethylamine, etc. Ammonia can also be used as a base in step (b) of the present invention. The purpose of using the base in this step (b) is to neutralize the acid generated, for example, by the hydrolysis of Si--X. bond when X a is a halogen (which generates hydrohalic acid). If the hydrohalic acid so generated can be removed by some other means such as by an aspirator, then the amount of base needed can be significantly reduced.
Generally, the amount of base employed in step (b) is from about 0.1 moles to about 2 moles per mole of halogen present in the organosilane derivative formed in step (a). The preferred amount is from about 0.8 mole to about 1.2 mole per mole of halogen present in the organosilane derivative formed in step (a) if the hydrohalic acid generated cannot be removed by any other means as mentioned above.
The temperature at which hydrolysis in step (b) is conducted ranges from about 0 ° C. to about 100° C., preferably from about 10° C. to about 50° C. The pressure in this step (b) is not critical and can be sub-atmospheric, atmospheric or super-atmospheric.
The hydrolysis reaction in step (b) undergoes spontaneously if the organosilane derivative formed in step (a) contains a halogen substituent (i.e., X a or X b ═halogen), and therefore, the reaction times in step (b) will generally be shorter ranging from about 1 minute to about 2 hours.
Using the procedure of step (b) outlined herein, the organosilane derivatized long-chain compound formed in step (a) undergoes suitable hydrolysis to form the corresponding organosilanol derivatized long-chain compound of the Formula III in Scheme I, wherein R 1 ,R 2 , R 3 ,R 4 ,R 5 ,R 6 ,R 7 ,R 8 , Y, a, b, c, and d are as defined above.
Generally, the organosilanol derivatized long-chain compound (Formula III) forms a stable dispersion in an aqueous medium. The dispersion can readily be solubilized to form a clear solution using a wide variety of organic solvents. Examples of such solvents that can be used for solubilizing organosilanol derivative (Formula III) includes methanol, ethanol, t-butanol, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, and the like.
The organosilanol derivative (Formula III) can also be isolated as a colloidal dispersion, microemulsion, emulsion, or a suspension depending upon the type of the reactor used and depending upon the nature of the substituents, X a ,X b , and Y used on the silicon atom. Generally, the nature of the dispersion formed depends upon the particle size of the organosilanol derivative (Formula III). Typically, the range of particle size in various compositions are as follows: solution--0.001 to 0.01 μm; colloidal dispersion (or solution)--0.001 to 0.1 μm; microemulsion--0.1 μm to 1.0 μm; emulsion--0.5 to 1.5 μm; and suspension-->1.0 μm. A detailed description of particle size in a dispersive composition may be found in "Water-Borne Coatings," (Hanser), pp 29-30, incorporated herein by reference in its entirety.
In another preferred embodiment of this invention, the organosilane compounds described herein and the method of preparing the same are useful in a wide diversity of applications. Particularly, the hydrolyzed organosilane compounds, i.e., the organosilanediol derivatives of the present invention are excellent emulsifying agents and form stable emulsions in water and thus are useful in a number of water-based formulations including paints, coatings, adhesives and inks formulations.
Various types of pigments, and anti-corrosive additives in paints, coatings and inks can be readily dispersed in the emulsions formed from the organosilanol derivatives of the present invention. The organosilanol derivatives of the present invention are obtained in the step (b) by the spontaneous hydrolysis of the organosilane derivatives formed in the step (a) of the process of the present invention. The organosilanol derivative so formed functions as a hydrosilylated surfactant and thus aids in the dispersion of a variety of pigments and anticorrosive additives.
The emulsions containing the organosilanol derivatives also impart a number of enhanced performance characteristics to the above mentioned formulations. The improved performances include, enhancement of gloss in paints, coatings and inks. The organosilanol derivatives also function as a defoamer in paints, coatings, inks, and adhesive formulations; as a crosslinker in paints, coatings, adhesives, and inks; as a corrosion inhibitor in paints; and as an adhesion promoter in paints, coatings, adhesives, and inks.
A further embodiment of the present invention is the use of the hydrosilylated surfactants of the present invention in emulsion polymer syntheses and subsequent use in coatings and adhesives including pressure sensitive and contact adhesives. These formulations can be used either at ambient conditions or at thermosetting conditions generally at elevated temperatures. The latex formulations formed in the emulsion polymerizations are also suitable to form inks.
Thus, a latex formulation containing the organosilanol derivatives of the present invention can be readily formed as follows. First, an emulsion containing the organosilanol derivatives in deionized water is formed. Then, a suitable monomer mixture to form the latex is fed into the emulsion in the presence of a suitable free radical initiator. The polymerization of the monomer mixture takes place in the resulting mixture to form a latex.
Various monomers may be employed for the formation of the latex. Examples of suitable monomers include, without limitation, vinyl acetate, methyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, phenyl acrylate, vinyl chloride, acrylonitrile, acrylamide, 2-ethylhexyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, glycidyl methacrylate, vinyl ester of versatic acid and the like. Various free radical initiators well known in the art may be used for the polymerization of the monomers. Representative examples of free radical initiators include ammonium persulfate, sodium persulfate, and potassium persulfate.
Optionally, the latex compositions of the present invention may also contain one or more additives such as wet adhesion promoters, protective/stabilizing colloids, fillers, water-dispersible resins, coloring agents, antiseptics, biocides, and the like. Particularly important additive employed in the latex composition of the present invention is a wet adhesion promoter. The wet adhesion promoter improves the adhesion of a latex to various surfaces such as plastic, glass, wood, metal, composites, ceramics, and the like. Several adhesion promoters well known in the art may be used with the latex of the present invention. Illustrative examples of such adhesion promoters include Sipomer®, WAM I and WAM II, sold by Rhone-Poulenc. The wet adhesion promoters may be present in an amount ranging from about 0.5 weight percent to about 5 weight percent based on the total weight of the latex.
In another aspect of the present invention, a process for the formation of polyalkyleneoxysilane derivatized long-chain fatty compounds is also provided. In this embodiment, the process as described above involves an additional intermediate step to introduce polyalkoxy groups by a substitution reaction. Accordingly, utilizing the substituted long-chain olefinic compound, Formula I, it is believed that the process comprising the additional intermediate step proceeds as shown in Scheme II below: ##STR8##
The starting material, i.e., the substituted long-chain olefinic compound, Formula I in Scheme II is the same starting material as described earlier in Scheme I, wherein R 1 ,R 2 ,R 3 ,R 4 , R 5 ,R 6 ,R 7 ,R 8 , a, b, c, and d are as defined above. Again, preferably the long-chain olefinic compound is a long-chain olefinic ester derived from a fatty oil as described above. The step (a), i.e., the hydrosilylation reaction described in Scheme II is identical to step (a) described in Scheme I, and can be carried out essentially under similar conditions as mentioned above. The substituents X a , X b and Y on silicon in Formula IV are the same or different and are as defined above with the proviso that at least two of these substituents are halogens selected from the group consisting of Cl, Br, and I. Preferably, X a and X b are either Cl or Br, and Y is either Cl, Br, or an alkyl or an alkoxy group having 1 to 20 carbon atoms.
Accordingly, the hydrosilylation is carried out preferably in the presence of a dihalosilane compound in this process of the present invention. Representative examples of such dihalosilane, i.e., Si--H containing moieties include trichlorosilane, dichloromethylsilane, dibromomethylsilane, chlorobromomethylsilane, iodochloro-methylsilane, diiodomethylsilane, dichloroethylsilane, dichlorophenylsilane, dichlorobutylsilane, and dichloromethoxysilane.
The substitution step, i.e., step (b) in Scheme II involves a substitution reaction of organosilane derivatized long-chain compound, Formula IV with a polyalkyleneoxy compound. The step (b) in Scheme II can be carried out under a variety of techniques well known in the art. Preferably, the substitution step, step (b) in Scheme II can be carried out by adding the polyalkyleneoxy compound to the organosilane derivatized long-chain compound (Formula IV) under suitable conditions, optionally, in the presence of a solvent.
The amount of polyalkyleneoxy compound employed in the substitution step (step (b), Scheme II) depends upon the number of halogen atoms present in Formula IV. Typically, polyalkyleneoxy compound in the amounts of from about 0.1 to about 1.1 moles per mole of halogen in Formula IV is employed. Preferably, 0.5 mole of polyalkyleneoxy compound per mole of halogen in Formula IV is employed.
A wide variety of polyalkyleneoxy compounds of varied molecular weights can be used in the substitution step (step (b), Scheme II). Illustrative examples of such polyalkyleneoxy compounds include monomethyl capped polyethylene glycols (MPEG) of the formula, CH 3 O(CH 2 --CH 2 O) n CH 2 --CH 2 OH; and monomethyl capped polypropylene glycols (MPPG) of the formula, CH 3 O(CH 2 --CH(CH 3 )O) n CH 2 --CH(CH 3 )OH; where n is an integer ranging from about 10 to about 250. As stated earlier, a variety of mixed polyalkyleneoxy compounds having 2 to 4 carbon atoms may also be employed. Examples of such mixed polyalkyleneoxy compounds include monomethyl capped polyethyleneoxy-propyleneoxy glycols of the formula, CH 3 O(CH 2 --CH 2 O) a --(CH 2 --CH(CH 3 )O) b --CH 2 --CH(CH 3 )OH, where a and b are integers ranging from about 10 to about 250. Particularly useful and preferred polyalkyleneoxy compound is MPEG.
As mentioned earlier, by varying the molecular weight of the polyalkyleneoxy compound in the substitution step (step (b), Scheme II), it is possible to alter the HLB value of the resulting organosilane derivatized long-chain compound, Formula V. Typically, the higher the molecular weight of the polyalkyleneoxy compound the higher the HLB number of the resulting organosilane derivative. The organosilane derivatives having an HLB numbers of from about 10 to about 18 are particularly preferred.
The temperature at which the substitution step (b) in Scheme II is conducted ranges from about 0° C. to about 100° C., preferably from about 10° C. to about 50° C. The pressure in this step (b) is not critical and can be sub-atmospheric, atmospheric or super-atmospheric.
In Scheme II, step (c) is a hydrolysis step and corresponds to step (b) of Scheme I and can be carried out under essentially similar conditions in the presence of a suitable base. The resulting organosilanol derivative of a long-chain olefinic compound, Formula VI spontaneously forms a dispersion in aqueous medium. As stated earlier, the dispersion can be solubilized by addition of a suitable solvent to form a clear solution or can be used as a colloidal suspension, microemulsion, emulsion, or a suspension depending on the particulate size of the resulting organosilanol surfactant (Formula VI) as described above.
This invention is further illustrated by the following examples which are provided for illustration purposes and in no way limit the scope of the present invention.
EXAMPLES (GENERAL)
In the Examples that follow, the following abbreviations are used:
HERO --High erucic acid rape seed oil.
HSCR--Hydrosilylated high erucic acid rape seed oil.
HSMETO--Hydrosilylated methyl ester of tung oil (eleostearic acid).
MPEG--Methyl capped polyethylene glycol, CH 3 O(CH 2 --CH 2 O) n --CH 2 --CH 2 --OH.
T g --Glass transition temperature.
NMR--Nuclear magnetic resonance spectroscopy, usually of either proton, 1 H; carbon 13, 13 C; and/or silicon 29, 29 Si nuclei.
IR--Infrared spectroscopy.
DSC--Differential Scanning Calorimetry.
MFT--Minimum film forming temperature.
General Analytical Techniques Used for the Characterization: A variety of analytical techniques were used to characterize the organosilane derivatized long-chain olefinic compounds of this invention which included the following:
NMR: 1 H and 13 C NMR spectra were recorded on a Bruker AX-200 MHz spectrometer with 5 mm probes at 200 and 50 MHz, respectively. 29 Si NMR spectra were recorded on a Bruker AX-300 MHz spectrometer with 5 and 10 mm probes at a frequency of 60 MHz.
Elemental Analysis: Quantitative estimation of silicon was performed by incinerating a weighed quantity of hydrosilylated material in silica crucibles at 1000° C. for 1 hour and cooling to room temperature.
Iodine value--It is the number of grams of iodine that combine with 100 grams of oil or fat which gives the degree of unsaturation of the acids in the substance. It is typically measured in carbon tetrachloride solution of the substance and treating it with a solution of iodine and mercuric chloride in ethanol.
Hiding Efficiency: The hiding efficiency was measured in accordance with ASTM procedure No. D 2805.
Gloss Measurements were made using a Gardco statistical novogloss meter in accordance with ASTM D 523-89.
Degree of Rusting was measured in accordance with ASTM Specification D610-85 (re-approved 1989), a standard test method used for evaluating degree of rusting on painted steel surfaces.
Cross-Hatch Adhesion tests were made in accordance with ASTM procedure No. D3359-87, a standard test method used for measuring adhesion by tape test.
DSC: A Mettler DSC-30 was used to determine the T g of the films (mid point value). The heating rate was maintained at 10° C./minute, generally, over a temperature range of -50° C. to 100° C. The flow rate of nitrogen is maintained at 20 mL/min.
MFT: MFT of latexes were determined by a MFFT Bar 90 equipment from Byk-Gardner in accordance with ASTM procedure No. D 2354.
Example 1
To 24.0 grams (0.10 mol of double bond equivalent, estimated from iodine value) of HERO, 50.0 mL of toluene that was freshly distilled from sodium was added and stirred to dissolve the oil. Dichloromethylsilane (4.0 mL, 0.04 mol) was dissolved in 25.0 mL of toluene in a pressure equalizer addition funnel. The oil that was dissolved in toluene was heated to 40° C. (sand bath temperature) and 0.18 grams of platinumdivinyltetramethyldisiloxane catalyst solution was added. To this warm solution of the oil, dichloromethylsilane was added dropwise with stirring under nitrogen over a period of 45 minutes. After complete addition of dichloromethylsilane, the solution had a dark tan color and was heated to reflux and the reaction was continued for 14 hours. Toluene was evaporated using a rotary evaporator after the completion of reaction time. The dark oily residue was dried in vacuo for 72 hours during which time a highly viscous oil with an amorphous solid, a combined weighing of 24.3 grams, had formed. The product, hydrosilylated high erucic acid rape seed oil (HSCR) was stored under nitrogen before use. The structure of the product was verified by 1 H, 13 C and 29 Si NMR and IR spectroscopy. Total amount of hydrosilylation by 1 H NMR analysis was found to be 24%.
Example 2
To 2 grams of HSCR obtained in Example 1, an equal amount of water was added and the mixture was stirred vigorously in an aspirator vacuum until all the liberated HCI gas was removed. A stable emulsion was formed with ease without the aid of any surfactant. The emulsion has a pleasant odor and does not settle on standing.
The hydrosilylated product so formed was laid on a Q panel, and was dried overnight in vacuo. It was then heated at 85° C. for two minutes to drive off any residual moisture. The dried product was a rubbery material insoluble in common organic solvents. The structure of the product was verified by 29 Si solid state NMR.
Example 3
Example 1 was substantially repeated in Example 3 with the exception that the reaction was carried out using tung oil instead of HERO as follows. To 75.1 grams of tung oil (0.490 mol of double bond equivalent, estimated from iodine value of tung oil), 150.0 mL of toluene that was freshly distilled from sodium was added and stirred to dissolve the oil. Dichloromethylsilane (7.83 mL, 0.076 mol) was dissolved in 50.0 mL of toluene in a pressure equalizer addition funnel. The oil that was dissolved in toluene was heated to 40° C. (sand bath temperature) and 0.563 grams of platinumdivinyltetramethyldisiloxane catalyst solution was added. To this warm solution of the oil, dichloromethylsilane was added dropwise with stirring under nitrogen over a period of 45 minutes. After complete addition of dichloromethylsilane, the solution had a dark tan color and was heated to reflux and the reaction was continued for a period of additional 5 hours. Toluene was evaporated using a rotary evaporator after the completion of reaction time. The dark oily residue was dried in vacuo for 72 hours during which time a highly viscous oil with an amorphous solid, a combined weighing of 84.2 grams had formed. The product, hydrosilylated tung oil was characterized in a fashion similar to HSCR as given in Example 1.
Example 4
Example 1 was substantially repeated in Example 4 with the exception that the reaction was carried out using linseed oil instead of HERO as follows. To 41.0 grams of linseed oil (0.266 mol of double bond equivalent, estimated from iodine value of linseed oil), 150.0 mL of toluene that was freshly distilled from sodium was added and stirred to dissolve the oil. Dichloromethylsilane (9.70 mL, 0.0887 mol) was dissolved in 50.0 mL of toluene in a pressure equalizer addition funnel. The oil that was dissolved in toluene was heated to 40° C. (sand bath temperature) and 0.500 grams of platinumdivinyltetramethyldisiloxane catalyst solution was added. To this warm solution of the oil, dichloromethylsilane was added dropwise with stirring under nitrogen over a period of 45 minutes. After complete addition of dichloromethylsilane, the solution had a dark tan color and was heated to reflux and the reaction was continued for 5 hours. Toluene was evaporated using a rotary evaporator after the completion of reaction time. The dark oily residue was dried in vacuo for 72 hours during which time a highly viscous oil with an amorphous solid, a combined weighing of 51.7 grams had formed. The product, hydrosilylated linseed oil was characterized in a fashion similar to HSCR as given in Example 1.
Example 5
Example 1 was substantially repeated in Example 5 with the exception that the reaction was carried out using methyl ester of eleostearic acid instead of HERO as follows. The methyl ester of eleostearic acid was obtained by the transesterification of tung oil with methanol using sodium hydroxide as the base. A 5 L kettle was set-up with a dropping funnel, condenser, and a nitrogen inlet. The reactor was first flushed with nitrogen. To this kettle, 172.2 grams of methyl ester of eleostearic acid was added followed by the addition of 0.95 grams of platinumdivinyltetramethyldisiloxane catalyst solution. The reaction mixture was heated to 40° C. Dichloromethylsilane (43.8 mL, 0.381 mol) was added in drops to the reaction mixture over a period of one hour. During the addition, the reaction mixture was stirred vigorously to ensure thorough mixing. After complete addition of dichloromethylsilane, the solution had a dark tan color. At this time the temperature of the reaction was raised to 110° C. and the reaction was continued for another three hours. After the reaction was over, the product was cooled to room temperature. The dark tan product, termed HSMETO, was hydrolyzed as such without further purification.
Example 6
Example 5 was substantially repeated in Example 6 with the exception that the following amounts of starting materials and reagents were employed:
Methyl ester of eleostearic acid 33.9 grams
Dichloromethylsilane 3.9 grams
Platinumdivinyltetramethyldisiloxane solution 0.156 grams
The hydrosilylation reaction was carried out at a temperature of about 140°-150 ° C for a period of about 4 hours. The yield of the resulting hydrosilylated product, HSMETO was 35.9 g (95%). This product was used as such in the next step of substitution reaction with MPEG without any further purification.
Example 7
This Example illustrates the substitution reaction of MPEG with HSMETO as formed in Example 6. To 35.9 grams of HSMETO taken in a 1 L Kettle, 180 grams of MPEG of the formula, CH 3 O(CH 2 --CH 2 ) n CH 2 --CH 2 --OH, where n is 45, dissolved in about 180 grams of methylene chloride was added over a period of about 1 hour. The stirring was continued for an additional period of about 8 hours during which time complete substitution of one of the chlorine atoms in HSMETO with MPEG took place. Evaporation of the solvent from reaction mixture resulted in 200 grams of the product in the form of a waxy solid (95% yield).
Example 8
This Example illustrates the hydrolysis of MPEG substituted hydrosilylated product obtained in Example 7. To 220 grams of MPEG substituted HSMETO, 200 mL of 10% ammonium hydroxide solution was added with vigorous stirring over a period of 2 hours. The pH of the solution during this addition was maintained at about 8 by addition of appropriate amounts of ammonium hydroxide solution. A stable emulsion was formed with ease without the aid of any other surfactant. The estimated yield of the emulsion containing, HSMETO-MPEG, was about 380 grams.
Example 9
This Example illustrates the utility of the emulsions formed according to Example 2 of the present invention in the dispersion of a pigment such as carbon black for coating applications. A carbon black of 13 μm particle diameter was chosen for this study, and a concentration of 6% dispersant to pigment by weight was used for the pigment grind composition. The results indicate that the pigment grind formulation containing the HSCR emulsion formed in accordance with Example 2 features much better properties than the control as evidenced by the improved hiding efficiency, gloss, degree of rusting for panels, and cross-hatch adhesion properties. The following table shows the composition of the pigment grind formulation and control used (Table 1).
TABLE 1______________________________________ Amounts in gramsReagents Example 9 Control______________________________________Carbon Black.sup.a (pigment) 16.0 16.0Deionized water 160.0 160.0HSCR (dispersant from Example 1) 0.96 0.0Commercial Dispersant (CD) 0.0 0.96Byk 022.sup.b (defoamer) 0.0 0.2______________________________________ .sup.a obtained from Cabot; .sup.b obtained from Byk Chemie.
The materials given in Table 1 were premixed using a Lightnin mixer at 300 rpm for 15 minutes. The dispersion process was continued with transfer to an Eiger "mini" 250 bead mill grinder with a 50% bead charge and was dispersed at 3000 rpm for 20 minutes to a Hegmann grid of 8. The pigment grind composition so formed was then used in a white latex paint of the composition given in Table 2.
TABLE 2______________________________________Reagents Amount in grams Supplier______________________________________TiO2 590.0 DupontDeionized Water 310.0 --Tamol 681 14.0 Rohm and HaasBubble Breaker 2056a 4.2 WitcoLet DownAquamac 700 916.0 McWhorterTexanol 7.0 ExxonRM 825 4.2 Rohm and Haas______________________________________
For evaluation of the pigment grind compositions given in Table 1, four different levels of latex formulations were made with the white latex paint formed from the formulation given in Table 2: 5.7%, 10.5%, 15.0% and 20.0%. These compositions were made by mixing specified grams of pigment grinds with 100 grams of the white latex paint, i.e., 5.7% HSCR means 5.7 grams of pigment grind formulation from Table 1 mixed with 100 grams of white latex formulation of Table 2 and so on. The performance properties of these formulations are given in Table 3.
TABLE 3__________________________________________________________________________Performance Properties__________________________________________________________________________Hiding Efficiency at PigmentedMill Base Concentration Example 9 Control__________________________________________________________________________ 5.7% 99.3 98.110.5% 99.7 98.515.0% 99.8 98.920.0% 100.0 100.0__________________________________________________________________________Gloss Measurements at PigmentedMill Base Concentration 20° 60° 85° 20° 60° 85°__________________________________________________________________________ 5.7% 11.5 54.7 78.7 8.6 54.1 78.510.5% 6.3 47.9 77.1 5.2 41.0 68.715.0% 3.7 33.1 37.0 2.8 29.9 32.020.0% 0.7 8.4 57.1 0.6 7.7 50.5__________________________________________________________________________Degree of Rusting for PanelsCoated with Carbon Black PaintFormulated at Pigmented Mill Base Film Area in % Rusting Film Area in % RustingConcentration. Thickness Rusting Grade.sup.a Thickness Rusting Grade.sup.a__________________________________________________________________________ 5.7% 2.02 0.03 10 2.06 0.3 710.5% 1.7 0.03 9 1.67 10.0 415.0% 1.84 0.3 7 1.77 16.0 320.0% 1.96 10.0 4 1.82 50.0 1__________________________________________________________________________Cross-Hatch Adhesion at Pig- Dry Film Adhesion Dry Film Adhesionmented Mill Base Concentration. Thickness Classification.sup.b Thickness Classification.sup.b__________________________________________________________________________ 5.7% 1.2 5B 1.4 4B10.5% 1.4 5B 1.48 3B15.0% 1.32 5B 1.35 3B20.0% 1.33 4B 1.2 2B__________________________________________________________________________ .sup.a 10 = best, 0 = worst; .sup.b 5B = best, 0B = worst
Example 10
This Example illustrates the dispersion of phthalocyanine green (obtained by the chlorination of phthalocyanine blue) in a stable emulsion formed in accordance with Example 2 using HSCR. Phthalocyanine green with a particle size distribution of 0.03-0.12 μm and with a surface area of 77 meters/square gram was used. The dispersion procedure as outlined in Example 9 was used. The pigment grind compositions for HSCR and control are given in Table 4.
TABLE 4______________________________________ Amounts in gramsReagents Example 10 Control______________________________________Phthalocyanine Green.sup.a (pigment) 16.0 16.0Deionized water 160.0 160.0HSCR (dispersant from Example 1) 0.96 0.0Commercial Dispersant (CD) 0.0 0.96Byk 022.sup.b (defoamer) 0.0 0.2______________________________________ .sup.a Obtained from Sun Chemical; .sup.b obtained from Byk Chemie.
The pigment grinds so formed were again mixed with a white latex formulation as given in Table 2 of Example 9. The following four paint grind compositions of Example 10 and the control were made: 5%, 11%, 15%, and 20% following the procedures of Example 9. The performance properties, hiding efficiency, and gloss, are summarized in Table 5.
TABLE 5______________________________________Performance Properties______________________________________Hiding Efficiency at Pigment-ed Mill Base Concentration. Example 10 Control______________________________________ 5.0% 99.0 98.211.0% 99.5 98.415.0% 99.9 99.120.0% 100.0 99.2______________________________________Gloss Measurements at Pig-mented Mill Base Concentra-tion. 20° 60° 85° 20° 60° 85°______________________________________ 5.0% 8.77 45.2 71.5 8.41 44.5 61.311.0% 7.05 43.2 72.4 4.08 33.8 67.1515.0% 7.08 41.5 37.4 2.5 24.7 32.820.0% 2.11 16.4 31.2 1.61 15.54 26.1______________________________________
Example 11
This Example illustrates the use of organosilanol derivatized long-chain olefinic ester as a surfactant in emulsion polymerization. A latex containing vinyl acetate (VA) and butyl acrylate (BA) monomers was synthesized as follows. A 500 mL reactor kettle was charged with deionized (DI) water and was deoxygenated for 1 hour at 80° C. This water was cooled to ambient temperature and used as DI and Deoxygenated (DO) water in the initial charge, pre-emulsion mixture and initiator solutions. The initial charge in the reactor included: 100 grams of DI water; 3.12 grams of hydrosilylated methyl ester of eleostearic acid, HSMETO (53% solids) made in accordance with Example 5; 2.63 grams of Rhodofac BX 660 (Rhone Phoulenc Inc. 80% solids); 0.54 grams of sodium carbonate; and 0.06 grams of ammonium persulfate. The reactor was then agitated at 200 rpm using a propeller angled at 45 degrees for 15 minutes to obtain a homogeneous mixture. The catalyst was added just before the addition of monomers.
A monomer mixture was prepared comprising the following monomer ratios: 75 grams of VA; 23.5 grams of BA; 0.75 grams of Sipomer Wam I (adhesion promoter from Rhone Poulenc Inc.); and 0.75 grams of Sipomer Wam II (adhesion promoter from Rhone Poulenc Inc.). The initiator solution was prepared by dissolving 0.4 grams of ammonium persulfate in 20.0 grams of DI water.
The monomer and initiator were fed separately using a peristaltic and syringe pump and using an automated data acquisition and control program. First, about 2 grams of the monomer mixture was added quickly into the reaction flask. The impeller was rotated at 200 rpm and the temperature was maintained at 80° C. using a water bath. A 10 minute reaction time was allowed for preseeding of the monomer initially added. After this time, the monomer addition was continued at a rate of 0.8 grams per minute for 1 hour and 50 minutes. To maintain starve fed conditions, the initiator solution was added for 2 hours and 9 minutes at a rate of 9.42 mL per hour.
After the addition of monomer mixture, the reactants were allowed to react for another 2 hours at 80° C. After which it was cooled slowly to ambient temperature. During this time, chaser solutions containing 0.03 g of t-butyl hydroperoxide in 4 mL of water and 0.04 grams of sodium formaldehyde sulfoxylate in 4 mL of water were added separately via syringe pumps. After reaction completion, the latex was filtered through a cheese cloth and was ready for property evaluation. The latex physical properties are given in the table below.
TABLE 6______________________________________Properties VA/BA/WamI/WamII______________________________________% Solids 44.4% Conversion 99.0% Coagulated none% Solid isolated on the sides of the 1.0reactor and impellerpH (as such after polymerization) 4.85MFT, °C. -1.5T.sub.g, °C. of dried film* (Experimental) 37.1 (Final T.sub.g of the latex after 6 months)T.sub.g, °C. (Theoretical by Fox equation) 7.0Particle size (nm) 166Nature of film clearLatex drying time 2 h______________________________________ *Latex film cast after adding 0.1% by weight cobalt hydrocure II and 0.1% DriRX-HF based on latex solids
Although the invention has been illustrated by certain of the preceding examples, it is not to be construed as being limited thereby; but rather, the invention encompasses the generic area as hereinbefore disclosed. Various modifications and embodiments can be made without departing from the spirit and scope thereof.
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Novel organosilane derivatized long-chain compounds containing halosilane and hydroxysilane groups are disclosed and claimed. A process for the syntheses of these novel compositions is also disclosed, which involves simple one-pot hydrosilylation reaction of substituted halosilanes with substituted long-chain olefinic compounds, and subsequent hydrolysis to form surface active silanol derivatives. Preferred embodiments include organosilane derivatives of fatty acids derived from tung oil, high erucic acid rape seed oil, and linseed oil. These compositions feature high surface activity in forming stable organic/water emulsions of various difficultly emulsifiable materials as compared with conventional emulsifying agents. These compositions are useful as reactive-dispersants, defoamers, reactive-surfactants in emulsion polymerization, crosslinkers, film formers, gloss enhancers, anticorrosive additives, adhesion promoters and as general property enhancers in coatings, adhesives and inks. These compositions contribute zero volatile organic components (VOC) to these formulations.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of priority of German Application No. 10 20140215 986.5, filed Aug. 12, 2014, and of German Application No. 20 2015 000 487.3, filed Jan. 19, 2015, each of which are incorporated herein by reference in their entirety.
BACKGROUND
[0002] The invention relates to a track widening system or wheel spacer system for motor vehicles. More particularly, embodiments of the present invention pertain to systems having at least one track widening disc or wheel spacer disc and at least one centering ring for insertion into the track widening disc. There heretofore lacks a universal system enabling track widening of differing amounts and centering on wheel rims having different diameters.
BRIEF SUMMARY OF THE INVENTION
[0003] An object of the invention is to provide a track widening system for motor vehicles which can be used in a flexible manner for different wheel rims and different vehicles.
[0004] To this end, there is provided according to some embodiments of the present invention a track widening system that may include at least one track widening disc and a centering ring which is inserted into a central opening of the track widening disc. The centering ring comprises plastics material. The centering ring may have at least one first catch device which is arranged at the free end of a resilient arm and the track widening disc has a corresponding second catch device.
[0005] Because the track widening system in accordance with some embodiments of the present invention may include a track widening disc and a separate centering ring, the track widening system can be flexibly adapted to different vehicles and different wheel rims. This is because the track widening disc has to fit on the wheel bolts of the vehicle and the centering ring must be adapted to the diameter of a central opening in the wheel rim so that the wheel rim is orientated during positioning on the centering ring precisely concentrically relative to the track widening disc or concentrically relative to the wheel hub or the pitch circle with the wheel bolts. The invention recognizes that the centering ring is not loaded during driving operation because the forces and momentums introduced by the wheel rim into the wheel hub and vice versa are transmitted exclusively by means of the track widening disc. Therefore, in some embodiments, the centering ring, which only carries out its centering function when the track widening disc is mounted and when the wheel rim is mounted, may comprise plastic material. The centering ring can thus be produced in a very cost-effective manner and also with extremely varied dimensions in order to be able to use the track widening system according to the invention for different vehicles and wheel rims. The centering ring may be constructed, for example, as a plastics injection-moulded component, especially fiber-reinforced plastics, because, as mentioned, it is not subjected to any loads at all during driving operation. The production of the centering ring from plastics material, in particular from plastics injection-moulded material, also makes it easier to produce different centering rings which then ensure the adaptation of the track widening discs to different wheel rims.
[0006] In some embodiments of the invention, the first catch device is in the form of a catch projection which projects outwards in a radial direction. In some implementations, the catch projection may be at the free end of a resilient arm which can readily be produced on a plastics component, such as a plastics injection-moulded component. As above, the centering ring may not subjected to any loads during driving operation and consequently the catch projection at the free end of a resilient arm may only be subject to forces which occur when the track widening disc and the wheel rim are mounted on the wheel hub. Advantageously, a plurality of resilient arms having catch projections may be provided on the centering ring at the free ends. In some implementations four resilient arms may be provided. However it is to be appreciated that other number of arms and catch projections are contemplated in accordance with some embodiments of the invention.
[0007] In some embodiments, the second catch device may be a shoulder which extends round the central opening. In some embodiments, the second catch device may be a chamfered portion which extends round the central opening. In some embodiments, the second catch device may be a groove which extends round the central opening.
[0008] A peripheral shoulder, a peripheral chamfered portion or a peripheral groove can be provided in the track widening disc, and unitarily formed. The track widening disc may be formed of metal, and thus the shoulder, chamfered portion, or peripheral groove can be mechanically processed at the same time other features of the track widening disc. For example, and without limitation, the peripheral shoulder, the peripheral chamfered portion or the peripheral groove can therefore be formed in the track widening disc, for example, during a turning process. The outwardly projecting catch projections on the centering ring may engage in the central opening of the track widening disc when the centering ring is introduced. In the case of thick track widening discs, a groove may be provided in the inner wall of the central opening and, in the case of relatively thin track widening discs, the catch projections of the centering ring may engage at a peripheral shoulder or a peripheral chamfered portion which may be arranged at the transition between the central opening and the upper side and/or lower side of the track widening disc.
[0009] In a development of the invention, the track widening disc may have a plurality of wheel bolt holes which are provided for the introduction of wheel bolts. A a dimension of the wheel bolt holes in a radial direction of the track widening disc may be from about 1.2 times to about 1.7 times. For example, and without limitation, it may be 1.5 times the diameter of the wheel bolts. In some embodiments, the track widening disc may have at least one curved slot which extends in the peripheral direction as a wheel bolt hole. In this manner, different hole configurations can be covered with a track widening disc. In this manner, the number of individual components necessary for the track widening system according to the invention in order to cover different vehicles and wheel rims can also be substantially reduced. Different pitch circles in different vehicles can be covered by means of such a configuration of the wheel bolt holes in the track widening disc. It is also thereby possible to substantially reduce the number of different track widening discs which are necessary for different vehicles.
[0010] In some embodiments of the invention, a plurality of centering rings may provided in the track widening system, wherein each centering ring has a retention portion for fixing to the track widening disc with at least a first catch device and a centering portion for arrangement in a central opening of a wheel rim. All the centering rings may have the same outer diameter in the retention portion and the centering rings may differ from each other at least partially in terms of the outer diameter of the centering portion.
[0011] It is thereby possible to ensure that all the centering rings which are different from each other can fit in all the track widening discs of the track widening system according to the invention and can be engaged therein. As already described, the corresponding second catch devices may also be arranged at mutually different track widening discs in an identical manner so that all the centering rings of the track widening system can be engaged.
[0012] In some implementations, a plurality of track widening discs of different thicknesses may be included in the track widening system.
[0013] In some implementations, the track widening discs may have differently arranged wheel bolt holes.
[0014] Although the track widening system in accordance with some embodiments of the invention may not require different track widening discs and different centering rings in order to be able to cover different vehicles and wheel rims, the necessary number of individual components, particularly the number of different track widening discs, can be substantially reduced. Different track widening discs may be provided to produce different dimensions for the track widening obtained.
[0015] The above-described objects, advantages and features of the invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described herein. In addition, individual features of different embodiments which are described and/or illustrated in the drawings may be combined with each other without exceeding the scope of the invention. Further benefits and other advantages of the present invention will become readily apparent from the detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an oblique view of a track widening system including a track widening disc and a first centering ring in accordance with some embodiments of the present invention.
[0017] FIG. 2 is a cross-sectional view of the system of FIG. 1 .
[0018] FIG. 3 is an oblique view of the system of FIG. 1 .
[0019] FIG. 4 is an oblique view of a track widening system including the track widening disc of FIG. 1 and a second centering ring in accordance with some embodiments of the present invention.
[0020] FIG. 5 is a cross-sectional view of the system of FIG. 4 .
[0021] FIG. 6 is an oblique view of the system of FIG. 4 .
[0022] FIG. 4 is an oblique view of a track widening system including the track widening disc of FIG. 1 and a third centering ring in accordance with some embodiments of the present invention.
[0023] FIG. 8 is a cross-sectional view of the system of FIG. 7 .
[0024] FIG. 9 is an oblique view of the system of FIG. 7 .
[0025] FIG. 10 is a plan view of a track widening disc of a track widening system in accordance with some embodiments of the present invention.
[0026] FIG. 11 is a cross-sectional view of FIG. 10 along section XI-XI.
[0027] FIG. 12 is a side view of a centering ring of a track widening system in accordance with some embodiments of the present invention.
[0028] FIG. 13 is another side view of the centering ring of FIG. 12 .
[0029] FIG. 14 is a cross sectional view of FIG. 13 along section A-A, including two enlarged detailed illustrations.
[0030] FIG. 15 is another side view of the centering ring of FIG. 12 .
[0031] FIGS. 16A-D are views different track widening discs, and FIGS. 16E-J are views of different centering rings, each in accordance with some embodiments of the present invention, shown centrally aligned.
[0032] FIGS. 17A and 17B are oblique forward and reverse side views of a centering ring of a track widening system in accordance with some embodiments of the present invention.
[0033] FIGS. 18A and 18B are oblique forward and reverse side views of a centering ring of a track widening system in accordance with some embodiments of the present invention.
[0034] FIGS. 19A and 19B are oblique forward and reverse side views of a centering ring of a track widening system in accordance with some embodiments of the present invention.
[0035] FIGS. 20A and 20B are oblique forward and reverse side views of a centering ring of a track widening system in accordance with some embodiments of the present invention.
[0036] FIGS. 21A and 21B are oblique forward and reverse side views of a centering ring of a track widening system in accordance with some embodiments of the present invention.
[0037] FIGS. 22A and 22B are oblique forward and reverse side views of a centering ring of a track widening system in accordance with some embodiments of the present invention.
[0038] FIG. 23 is a cross-sectional view of a centering ring of a track widening system in accordance with some embodiments of the present invention.
DETAILED DESCRIPTION
[0039] Reference will now be made in detail to certain embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in reference to these embodiments, it will be understood that they are not intended to limit the invention. To the contrary, the invention is intended to cover alternatives, modifications, and equivalents that are included within the spirit and scope of the invention as defined by the claims. In the following disclosure, specific details are given to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without all of the specific details provided.
[0040] FIG. 1 illustrates a track widening disc 10 having a centering ring 12 of the track widening system according to the invention. The track widening disc 10 is illustrated has having a total of six wheel bolt holes 14 , 16 , 18 , 20 , 22 and 24 , however it is to be appreciated that other number of holes are contemplated in accordance with some embodiments of the present invention. The wheel bolt holes 16 , 18 , 20 and 24 may be constructed as circular holes whereas the wheel bolt holes 14 and 22 may be constructed as slots which extend in a peripheral direction of the track widening disc 10 . Usually, wheel hubs of motor vehicles are provided with four or five wheel bolts. The wheel bolt holes 14 to 24 may consequently not all be used simultaneously for the introduction of wheel bolts but are instead arranged in such a manner that different hole configurations of wheel hubs can be covered with a single track widening disc 10 . The two slots 14 , 22 which are curved in a rounded manner may also used for this. Furthermore, the diameter of the circular wheel bolt holes 16 , 18 , 20 , 24 and the dimension of the wheel bolt holes 14 , 22 when viewed in a radial direction may be from about 1.2 to 1.7 times, and in some preferred embodiments 1.5 times, as large as the outer diameter of the wheel bolts used. Slightly different pitch circle diameters of wheel bolts in different vehicles can thereby be covered.
[0041] The centering ring 12 , when viewed from the visible rear side of the track widening disc 10 in FIG. 1 , may be inserted therein and may have a peripheral, chamfered collar 26 which defines an end position of the centering ring 12 on the track widening disc 10 in an axial direction. The abutment of the collar 26 against a corresponding chamfered portion 28 at the transition of the rear side of the track widening disc 10 into the central hole 30 thereof can be seen in the cross-section of FIG. 2 , which rear side is shown at the top in FIG. 2 .
[0042] The centering ring 12 may have four resilient arms 32 , at the free end of which a catch projection 34 is arranged, respectively. However it is to be appreciated that other numbers of resilient arms are contemplated in accordance with some embodiments of the present invention. The illustration of FIG. 1 depicts only two resilient arms 32 and associated catch projections 34 . The catch projections 3 may engage in a groove 36 which extends radially outwards from the central opening of the track widening disc 10 . As a result, in some examples, the centering ring 12 may be introduced into the track widening disc 10 by the centering ring 12 in FIG. 2 being pushed into the track widening disc 10 from above until the chamfered collar 26 abuts the chamfered portion 28 of the track widening disc 10 and, at the same time, the catch projections 34 engage in the peripheral groove 36 . The catch projections 34 can be disengaged from the groove 36 by a tool, for example, a screwdriver, being inserted into the recesses 35 of the centering ring 12 . However, the catch projections 34 may also be disengaged without tools, such as by pressing powerfully on the centering ring 12 .
[0043] The centering ring 12 may have a retention portion 38 whose outer diameter is only slightly smaller than the inner diameter of the central opening of the track widening disc 10 . The centering ring 12 may be retained with this retention portion 38 in the central opening of the track widening disc 10 and centered in relation to the central opening. Furthermore, the centering ring 12 may include a rim centering portion 40 which projects beyond the front side of the track widening disc 10 , which side is shown at the bottom in FIG. 2 , and may be provided in order to be pushed into the central opening of a wheel rim. Consequently, the outer diameter of the circular-cylindrical rim centering portion 40 corresponds to the diameter of the central opening of the wheel rim provided for assembly or is only slightly smaller than the diameter of that central opening. The inner diameter of the retention portion 38 , said inner diameter forming a hub centering portion 41 , may correspond to the outer diameter of the rim centering portion 40 . The rim centering portion 40 can be made slightly conical which is explained in detail in conjunction with FIG. 23 .
[0044] The centering ring 12 may also have a hub centering portion 41 which is intended to be placed on the outer diameter of a wheel hub. By simply pushing the hub centering portion 41 onto the wheel hub, the centering ring 12 and the track widening disk 10 can then be centered on the wheel hub. According to some embodiments of the invention, different centering rings 12 may be provided with different inner diameters of the hub centering portion 41 in order to be used with different types of vehicles having different outer diameters of the wheel hub. The hub centering portion 41 can be made slightly conical which is explained in detail in conjunction with FIG. 23 .
[0045] It can be seen in FIG. 1 and FIG. 2 that different centering rings 12 can be introduced into the track widening disc 10 in the track widening system according to the invention in order to be able to centre wheel rims having different diameters in respect of their central openings relative to the track widening disc 10 . It can further be seen that the track widening disc 10 can be used for different pitch circles and different hole configurations of wheel hubs of vehicles. Consequently, the track widening system according to the invention makes it possible to manage with substantially fewer individual components and be able to cover a large number of different vehicles and different wheel rims.
[0046] The illustration of FIG. 3 is an oblique front view of the track widening disc 10 with the centering ring 12 inserted. As shown, the centering portion 40 of the centering ring 12 may project beyond the front side of the track widening disc 10 and can thereby be introduced into the central opening of a wheel rim.
[0047] The illustrations of FIGS. 4 to 6 show the track widening disc 10 which has already been illustrated in FIG. 1 , with a different centering ring 42 having been introduced into the track widening disc 10 . Centering ring 42 may have a retention portion 44 having the same outer diameter as the centering ring 12 . Therefore, the centering ring 42 can also be introduced into the central opening of the track widening disc 10 and, similarly to the centering ring 12 , can be engaged in the groove 36 of the track widening disc 10 by means of catch projections.
[0048] Unlike the centering ring 12 , the centering ring 42 may have a centering portion 40 with an outer diameter which is smaller than the centering portion 40 of the centering ring 12 . By the centering ring 42 being introduced into the track widening disc 10 in place of the centering ring 12 , consequently, the track widening disc 10 can be adapted to wheel rims with a smaller diameter of the central opening.
[0049] The illustrations of FIGS. 7 to 9 show the track widening disc 10 of FIG. 1 , with a different centering ring 52 having been introduced into the central opening of the track widening disc 10 in place of the centering ring 12 . The centering ring 52 may also have (and as illustrated more fully in the cross-sectional illustration of FIG. 8 ) a retention portion 54 which may have the same outer diameter as the retention portion 38 of the centering ring 12 (as shown in FIG. 2 ) and the retention portion 44 of the centering ring 42 (as shown in FIG. 5 ). The centering ring 52 can also be introduced into the central opening of the track widening disc 10 and can be engaged in the groove 36 of the track widening disc 10 by means of the catch projections on the catch arms.
[0050] Unlike the centering rings 12 , 42 , the centering ring 52 may have a centering portion 56 with an even smaller outer diameter. By the centering ring 52 being introduced, consequently, the track widening disc 10 can be used for wheel rims having an even smaller diameter of the central opening.
[0051] The illustration of FIG. 10 is a plan view of another track widening disc 60 according to the invention. The track widening disc 60 may have, similarly to the track widening disc 10 of FIG. 1 , a total of six wheel bolt holes 14 , 16 , 18 , 20 , 22 and 24 , however other numbers of wheel bolt holes are contemplated in accordance with some embodiments of the present invention. It can clearly be seen in FIG. 10 that track widening disc 60 may have two curved slots 14 , 22 extending over an angular range a in order to be able to cover wheel hubs having different hole configurations.
[0052] The illustration of FIG. 11 is a plan view of the plane of section XI-XI of FIG. 10 . As illustrated, a groove 36 , in the central opening 30 of the track widening disc 10 , may be provided for the catch projections of the centering rings. Also illustrated is the chamfered portion 28 at the transition of the rear side of the track widening disc 60 into the central opening, which rear side is arranged on the left in FIG. 11 . As discussed above, the chamfered portion 28 may serve to receive the collar 26 of the centering rings, which collar may also be chamfered, and thereby form a stop when the centering ring is introduced into the track widening disc 60 .
[0053] The illustration of FIG. 12 is a side view of the centering ring 42 of FIG. 5 . As above, the centering ring 42 may have a retention portion 44 whose outer diameter is adapted to the inner diameter of the central opening of the track widening discs and in which the catch arms 32 are also arranged, at the free ends of which there may also be arranged catch projections 34 which extend radially outwards in relation to the centering ring 42 . When viewed over the periphery of the centering ring 42 , a total of four catch arms 32 each having a catch projection 34 are arranged at the free end. However it is to be appreciated other numbers of catch arms are contemplated in accordance with some embodiments of the invention. A frustoconical chamfered portion 43 may be provided at the transition between the retention portion 44 and the centering portion 42 . That chamfered portion may vary with the difference in diameter between the retention portion 44 and the centering portion 42 . A plurality of slot-like recesses 45 may be provided in the chamfered portion 43 over the periphery. Those recesses 45 may be used to keep the material thickness of the centering ring substantially constant in order to prevent deformation of the plastics material during manufacturing.
[0054] The illustration of FIG. 13 is a front view of the centering ring 42 (e.g., from the left in FIG. 12 ). FIG. 14 is a cross-section along the line A-A in FIG. 13 . Consequently, the planes of section extend in FIG. 14 through a catch arm 32 having a catch projection 34 and, at the bottom in FIG. 14 , through one of the recesses 45 . FIG. 14 further contains two enlarged detailed illustrations, in which the regions of FIG. 14 have been illustrated to an enlarged scale, which regions are circled in a dot-dash manner.
[0055] FIG. 15 is a rear view of the centering ring 42 of FIG. 12 , that is to say, from the right in FIG. 12 .
[0056] The illustrations of FIGS. 16A to 16J show by way of example a track widening system according to the invention having a total of four different track widening discs 70 ( FIG. 16A ), 72 ( FIG. 16B ), 74 ( FIG. 16C) and 76 ( FIG. 16D ). It is to be appreciated that although four track widening discs are illustrated in the example of FIGS. 16A-D , track widening systems in accordance with some embodiments of the present invention may include other numbers of track widening discs. The track widening discs 70 and 72 are illustrated as differing in terms of the thickness thereof, as do the track widening discs 74 and 76 . The track widening discs 70 , 72 are illustrated as having a greater outer diameter than the track widening discs 74 , 76 . In some embodiments, a diameter of a central opening of the track widening discs 70 , 72 , 74 , 76 is always constructed so as to be precisely the same so that different centering rings can be introduced into each of the track widening discs 70 , 72 , 74 and 76 . As illustrated, in some embodiments six different centering rings 78 ( FIG. 16E ), 80 ( FIG. 16F ), 82 ( FIG. 16G ), 84 ( FIG. 16H ), 86 ( FIGS. 16I) and 88 ( FIG. 16J ) can be introduced into the track widening discs 70 , 72 , 74 and 76 . However it is to be appreciated that track widening systems in accordance with some embodiments of the present invention may include other numbers of centering rings. With reference to FIGS. 16E to 16J , it can also be seen that the centering rings 78 , 80 , 82 , 84 , 86 , 88 may differ in terms of the outer diameter of the centering portion thereof and may also differ in terms of the axial length of the retention portion thereof. However, the catch projections 34 with which the centering rings 78 , 80 , 82 , 84 , 86 , 88 are engaged with the track widening discs 70 , 72 , 74 , 76 are, in preferred embodiments, always arranged with the same spacing from the chamfered collar 26 of the centering rings 78 , 80 , 82 , 84 , 86 , 88 . This makes it possible for track widening discs 70 , 72 , 74 , 76 and centering rings 78 , 80 , 82 , 84 , 86 , 88 to be interchanged.
[0057] In some embodiments, the centering rings 78 , 80 may have the same outer diameter of the centering portion and may have for identification a different but related colour (e.g. dark red and light red). The centering rings 82 , 84 may have a larger diameter of the centering portion when compared to the centering rings 78 , 80 ; both centering rings 82 , 84 , however, in accordance with some embodiments of the invention, may have the same outer diameter of the centering portion. The centering rings 78 , 80 may have for identification a different but related colour (e.g., yellow and orange) which is different than the colouring of the centering rings 78 , 80 . The centering rings 86 , 88 are illustrated as having the biggest diameter of the centering portion of all centering rings and, for identification, may have a different but related colour (e.g. a bright white and a darker white) which is different than the colouring of the other centering rings. It is to be appreciated that, in preferred embodiments, all centering rings of different dimensions (e.g., centering rings 78 , 80 , 82 , 84 , 86 , 88 ) may have a different colour. It is further to be appreciated that in accordance with some embodiments of the invention other identifying features may distinguish the different centering rings. For example, and without limitation, the centering rings may have text or symbolic markings thereon for distinguishing purposes. In preferred embodiments, centering rings having the same outer diameter of the centering portion may have a related colour. Such a colour identification system according to the invention is independent of the provision of catch devices. As a consequence, such a colour identification system is independent of the provision of the catch projections 34 on the catch arms 32 and can be realized with centering rings without catch devices.
[0058] The illustrations of FIGS. 17A-B , 18 A-B, 19 A-B, 20 A-B, 21 A-B, and 22 A-B show in each case two views of the centering rings 78 , 80 , 82 , 84 , 86 , 88 , respectively, an oblique front view and an oblique rear view.
[0059] FIG. 23 shows a schematical cross-section of a centering ring 12 according to the invention. FIG. 23 is not drawn to scale, rather, the conicity of the hub centering portion 41 and the rim centering portion 40 is exaggerated to show these features. Apart from the special shape of the rim centering portion 40 and the hub centering portion 41 , the centering ring 12 may comprise the same features as the centering rings already described.
[0060] As above with reference to FIGS. 1 and 2 , the retention portion 38 of the centering ring 12 may be fixed to a track widening disk 10 (not illustrated in FIG. 23 ). Together with the centering ring 12 , the track widening disk 10 may be pushed onto the wheel hub of a car. The inner diameter of the centering portion 38 may be formed by the hub centering portion 41 . The inside of the chamfered collar 26 may help to center the centering ring 12 on the wheel hub. The hub centering portion 41 can be slightly conical, as illustrated in FIG. 23 . Again, FIG. 23 is not drawn to scale, and the conicity of hub centering portion 41 is strongly exaggerated to illustrate some embodiments of the invention. The centering ring 12 may be pushed onto the circular cylindrical outer diameter of the wheel hub. The hub centering portion 41 may have a wider diameter adjacent the chamfered collar 26 and a narrower diameter in a direction away from the chamfered collar 26 . When pushing the centering ring 12 onto the wheel hub, the centering ring 12 may, therefore, be centered onto the wheel hub. In such implementations of the invention, tolerances of the outer diameter of the wheel hub can be compensated. By making the hub centering portion 41 slightly conical, the centering ring 12 can be placed onto the wheel hub free from play. In addition, since the centering ring 12 may comprise plastic, the slight conicity of the hub centering portion 41 makes it easier to get the centering ring 12 out of a form during manufacturing. In some examples, and without limitation, the diameter of the hub centering portion 41 narrows by a few tenths of a millimetre (e.g., if the diameter of the hub centering portion 41 amounts to 58.3 mm at its upper end in FIG. 23 adjacent to the chamfered collar 26 , it may then narrow down to 58 mm at its lower end). It is to be appreciated that other dimensions are contemplated in accordance with some embodiments of the invention.
[0061] It can also be seen in FIG. 23 that the rim centering portion 40 may also be slightly conical and narrow its diameter from top down in FIG. 23 . The conicity of the rim centering portion 40 is also strongly exaggerated in FIG. 23 to illustrate some embodiments of the invention. The largest diameter of the rim centering portion 40 may be, therefore, placed adjacent to the retention portion 38 and the smallest diameter of the rim centering portion 40 may be placed at the end of the centering ring 12 opposite the retention portion 38 . When a wheel rim is placed onto the centering ring 40 , tolerances of the inner diameter of the central opening of a wheel rim can therefore be compensated. By making the rim centering portion 40 slightly conical, the centering ring 12 can, therefore, be arranged without play in the central opening of a wheel rim. In addition, making the rim centering portion 40 slightly conical makes it easier to get the plastic centering ring 12 out of its form during manufacturing. In some examples, and without limitation, the diameter of the rim centering portion 40 narrows for only a few tenth of a millimetre (e.g., if the diameter of the rim centering portion 40 amounts to 58 mm at its upper end in FIG. 23 , adjacent the retention portion 38 , it will narrow down to 57.5 mm at its lower end). It is to be appreciated that other dimensions are contemplated in accordance with some embodiments of the invention.
[0062] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is to be understood that variations and modifications of the present invention may be made without departing from the scope thereof. It is to be appreciated that the features disclosed herein may be used different combinations and permutations with each other, all falling within the scope of the present invention. It is also to be understood that the present invention is not to be limited by the specific embodiments disclosed herein, but only in accordance with the appended claims when read in light of the foregoing specification.
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The invention relates to a track widening system for motor vehicles, having at least one track widening disc and at least one centering ring which is inserted into a central opening of the track widening disc, wherein the centering ring has at least one first catch device which is arranged at the free end of a resilient arm and wherein the track widening disc has a corresponding second catch device. The centering ring may comprise plastic, and may be fiber-reinforced. One or more centering rings may have different colors.
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This is a division of application Ser. No. 036,639, filed Apr. 10, 1987 now U.S. Pat. No. 4,781,548.
BACKGROUND OF THE INVENTION
Proper treatment of a patient frequently requires that a particular medicament be introduced into the body in liquid form. Continuousin fusion is preferred when it is desired that the concentration be substantially constant or otherwise appropriately controlled over a given length of time. This control may be effected through a metering valve or, in certain cases, through the use of a pump. Regarless of how control is attempted, it has not been possible with prior art devices to provide accurate control over the delivery of essentially all of the large number of medicaments now in use. For this reason, a great number of infusion systems have been developed, each primarily directed towards infusion of a particular medicament.
The simplest infusion system involves a metering valve downstream of a conventional intravenous (I.V.) fluid containing container. These I.V. Containers are usually attached to a support stand so that the fluid flows under gravity condition through an inclined ramp metering valve. Unfortunately, these simple systems cannot maintain constant drip rate, are cumbersome and substantially prevent ambulation of the patient, and the valves do not adequately respond to changes, such as volume changes, patient changes and the like.
Various types of pumps have also been utilized in an attempt to provide accurate infusion over a given period of time. The most common type of pump involves peristaltic action. We have found that peristaltic action is itself subject to certain difficulties because of the rolling nature of the Wave, as well as the inability to accurately control the pumped volume.
As noted, each particular medicament must usually be infused with a pump system specifically designed therefor, such that a large number of infusion systems are required in a modern hospital complex. The large number of infusion pumps required may allow mistakes to occur due to the unfamiliarity of the attendant personnel with the particular pump. Naturally, each infusion pump has its own settings, connections and the like, thereby greatly increasing the amount of information which the attendant personnel must possess to adequately utilize these systems. Training of the attendant personnel is thereby complicated and only serves to increase total hospital costs.
Hospitals have recently been under great pressure to minimize costs. The ever increasing number of infusion systems only serves to increase costs, thereby adding to consumer complaints. Ambulation of the patient is one means for shortening the hospital stay, thereby one means for decreasing patient costs.
The disclosed invention is an infusion pump system and conduit which is designed to replace the large number of infusion systems presently known. The disclosed invention includes a modular infusion pump which is extremely lightweight, thereby permitting ready ambulation by the patient. Furthermore, the invention is battery powered, thereby cutting the tether to the A/C power supply system. Lastly, the disclosed invention is a positive displacement volumetric pump which operates on a known pumping volume, thereby assuring accurate delivery and includes a brake assembly to prevent reverse infusion as can occur in prior art pumps.
OBJECTS AND SUMMARY OF THE INVENTION
The primary object is an infusion pump system which is lightweight, portable and capable of use with the infinite number of medicaments now requiring separate infusion systems.
The infusion pump system of the invention is operable on a resilient longitudinal tube to cause a medicament to be pumped therethrough. A plurality of fixed spaced apart first combs define a contoured surface for receiving the tube. A door closing the system housing positions the tube into enlagement with the first combs and maintains the tube there so that a known pumping volume is achieved. A plurality of movable spaced apart second combs are interdigitated with the first combs for reciprocally compressing the pumping volume for causing fluid to be selectively expelled therefrom, or drawn there into. Valves are positioned upstream and downstream of the pumping volume for selectively closing and opening the tube to permit fluid flow to or from the pumping volume. A rotary drive system includes a rotary to linear conversion device which displaces the second combs and the valves for causing selective operation thereof. A brake is connected with the rotary drive system for preventing unintended rotation thereof, and thereby prevents unintended movement of the second combs such as could cause fluid to be siphoned back into the pumping volume.
The disclosed invention is a positive displacement volumetric infusion pump. The pump has a high degree of accuracy per pumping cycle. The pumping tube has an oblong shape conforming to the contoured configuration of the fixed combs in order to achieve a fixed reference volume and, because of the shape, requires less force for compression, thereby saving battery power. The pump may automatically purge itself of air through appropriate maniuplation of the valves. Furthermore, a one way brake prevents back slippage and permits the motor to be turned off after each cycle, so that the motor remains off during the majority of the time.
The disclosed infusion pump has a unique pumping chamber and a high efficiency pumping system that is self-priming and purges air from the delivered fluid. The positive displacement volumetric pump delivers a precise volume during each stroke. The system provides universal service for all pressure and gravity administered tasks. The invention replaces the prior art peristaltic roller pumps, syringes, transfer diaphrams, plunger systems and the like.
A microprocessor controls the pump mechanism and has a video display to permit all appropriate parameters to be set, as well as to display selected operating parameters as may be required. The pump is programmed with the help of "lead-through" prompts, thereby assuring that all pertinent information is input for proper operation, and also lessening the information which the attendant personnel must remember.
These and other objects and advantages of the invention will be readily apparent in view of the following description and drawings of the above described invention.
DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages and novel features of the present invention will become apparent from the following detailed description of the preferred embodiment of the invention illustrated in the accompanying drawings, wherein:
FIG. 1 is a perspective view illustrating the infusion system of the invention;
FIG. 2 is a fragmentary cross-sectional view illustrating the pumping system of the invention;
FIG. 3 is a fragmentary cross-sectional view taken along the line 3--3 of FIG. 2 and viewed in the direction of the arrows;
FIGS. 4-5 are fragmentary cross-sectional views illustrating the compression of the medicament delivering tube of FIG. 3 during the pumping cycle;
FIG. 6 is a front elevational view of the administration set of the invention;
FIG. 7 is a fragmentary cross-sectional view thereof;
FIG. 8 is a cross-sectional view illustrating the drive system of the invention in cooperation with the administration set of FIG. 6;
FIG. 9 is a cross-sectional view taken along the section 9--9 of FIG. 8 and viewed in the direction of the arrows; and,
FIG. 10 is a schematic diagram illustrating the control circuit of the invention.
DESCRIPTION OF THE INVENTION
Infusion pump system P, as best shown in FIG. 1, is contained within housing H. The housing H is, preferably, manufactured from a high strength plastic or similar lightweight material in order to permit the pump system P to be readily carried by the patient (not shown). Preferably, housing H has a carrying handle 10 extending along the top surface. The housing H, along with its related ancillary items, weights approximately 2.5 pounds, this including the weight of the batteries which provide the operating power.
Housing H has a first chamber 12 extending along a sidewall thereof and in which a first modular pump unit U, as will be further described, is positioned. A second chamber 14 is disposed adjacent first chamber 12 and likewise receives a pump unit U. Chamber 12 preferably contains a piggyback pump unit which pumps a secondary medicament which is contained within lower chamber 16. The primary medicament is contained within medicament bottle 18 positioned within side housing 20. A syringe 22 may be advantageously positioned within housing 20 for use by the patient as needed. FIG. 1 also discloses medicament supply line 24 which is in flow communication with primary pump unit U of chamber 14.
Control unit C is contained within chamber 26 of housing H and is used for setting the operating parameters, as well as for monitoring the operating parameters of the individual pump units U.
Control unit C, as best shown in FIG. 1, includes a video display 28 and programming push buttons 30. The control unit C also includes indicator lights 32 and 34 which let the operator know if the particular parameter of interest is being raised or lowered. Similarly, indicating lights 36 and 38 are provided to indicate a hold function, as well as an alarm mode, respectively. Lastly, control unit C includes a programming module 40 to allow the operator to select which of the pumping units U is to be displayed or adjusted. As noted, the programming module 40 includes indicators 42, 44 and 46 because the pumping system P can handle as many as 3 pump units U.
FIGS. 8 and 9 disclose the high efficiency pump mechanism which each pump unit U employs in order to provide an accurate controlled pumped volume of medicament. Each pump unit U includes a generally rectangular housing 48 having a pivotal door 50. The door 50 has a transparent window 52 to permit the operator to view fluid ducts F during use. FIG. 9 discloses recess 54 which receives and positions the duct F for operation.
An upper member 56 and a lower member 58 extend from the rear wall of housing 48 in general parallel alignment. The members 56 and 58 extend toward the door 50, although they stop short thereof. Rotatable shaft 60 extends between the members 56 and 58, and preferable is supported by bearings 62 and 64 in order to permit free rotation thereof. Driven gear 66 is carried by shaft 50 and is secured thereto by nut 68. Ratchet pawl 70 pivots on pin 72 in order to provide a brake permitting the gear 66 to rotate in one direction only.
Electric motor 74, which preferably is a direct current motor, has a rotatable shaft which carries a drive gear 76. The drive gear 76 is in meshing engagement with the driven gear 66 in order to cause rotation of same. Naturally, appropriate wiring is provided for connecting the motor 74 with the control unit C, as well as with the source of electric power, and need not be further explained.
First slidable valve 78 is carried by support member 56 and includes a contact portion 80 which is engageable with fluid duct F to compress, and thereby close, same. A pump shoe 82 is slidably disposed relative to valve 78 and likewise includes a plurality of contact portions, as will be further explained, for compressing duct F. Second valve 84 1s slidably disposed relative to shoe 82 and member 58. Valve 84 has a contact portion 86 which is likewise used for compressing, and thereby closing, duct F. The valves 78 and 84 may be slidably keyed to shoe 82 and likewise to members 56 and 58, respectively or all may be positioned between parallel guide plates.
Cam 88 is carried by shaft 60 and is engageable with rotatable cam follower 90 carried by valve 78 for causing linear displacement of the valve 78.
Cams 92 and 94 are carried by shaft 60. The cams 92 and 94 are engageable with rotatable cam followers 96 and 98, respectively, carried by shoe 82 for likewise causing linear displacement of pump shoe 82. The cams 92 and 94 are spaced apart in order to prevent canting of the shoe 82 during displacement.
Cam 100 is carried by shaft 60. Cam l00 is engageable with rotatable cam follower 102 carried by valve 84 for causing linear displacement of valve 84. It should be clear that the cams 88, 92-94 and 100 are appropriately adjusted so that the nodes thereof cause selected linear displacement of the associated valves 78 and 84, respectively, as well as of pump shoe 82.
Administration set A is best shown in FIGS. 6 and 8 and provides the fluid duct F which is secured by the door 50. The administration set A includes an upper drip chamber 104 which is in flow communication with pump chamber 106 by means of variable orifice valve 108 disposed across duct 110. Preferably, the drip chamber 104 is integral with the pump chamber 106 and both are comprised of a resilient, preferably, transparent polymeric material, such as urethane or silicone, which is easily compressible, for reasons to be explained. Set A may be used independently of unit U as a metering valve.
Drip chamber 104 has an inlet opening 112 in which orifice 114 is received. The orifice 114 is preferably manufactured from a non-wetting material, such as Teflon, or is coated with a corresponding substance. The non-wetting material controls drop size and thereby further insures accurate delivery of the medicament to drip chamber 104. Naturally, orifice 114 has an inlet opening 116 for connection with a fluid supply source, such as hose 24 of container 18. Vent 118 communicates through orifice 114 with drip chamber 104 and includes ball check 120 to prevent entry of contaminants into the drip chamber 104 through vent 118.
Valve 108 includes a handle 122 which controls logarithmic opening 124. Rotation of handle 122 therefore provides logarithmic control over the quantity of fluid which can flow from the drip chamber 104 to the pump chamber 106. Additionally, the handle 122 may include means cooperating with the door 50 to secure same in the locked, or closed position. This assures that the valve 108 is in the off position when the unit U is initially set up, in order to prevent full flow of medicament to the patient.
Pump chamber 106 includes a circular outlet opening 126 which is connected with cannula 128. The cannula 128 is of conventional design and permits the medicament to flow to the patient much as with prior art systems.
The pumping chamber 106 will now be explained with reference to FIGS. 2-5. As noted, fluid duct F, which includes the administration set A, is secured within housing 48 by means of door 50 and window 52. The window 52 presses the fluid duct-F against first fixed position combs 130. The combs 130 are fixed relative to the supports 56 and 58 and extend towards door 50 and therefore provide a contoured surface for receipt of wall portion 132 of duct F. The fixed position combs 130 encompass wall portion 132 and define a known pumping volume for the pumping chamber 106. The known pumping volume assures that a constant volume of medicament is always present at the time of initiation of the pumping stroke. The fixed position combs 130 in cooperation with the door 50 trap a known area of the wall portion 132 within the area between the valves 80 and 86. As such, this trapped pumping volume remains constant, regardless of the material being pumped. The fixed position combs 130 are spaced apart longidutinally along the duct F by an amount sufficient to prevent the wall portion 132 from ballooning therebetween. Consequently, when pumping force is applied to the wall portion 132, as will be further explained, then the wall portion 132 will not expand into the area between the fixed combs 130 and thereby alter the pumping volume.
Movable combs 134 extend from pump shoe 82 and are interdigitated with the fixed position combs 130. The movable combs 134 move uniformly linearly through the adjacent spaced fixed combs 130 in order to compress the wall portion 132. Because of the spaced apart cams 92 and 94, then there is little or no tendency for the shoe 82 to cant, with the result that the combs 134 all move by the same amount, in the same unit time, and with equal force for causing substantially constant and uniform compression, and thereby pumping, of the wall portion 132.
FIGS. 3-5 illustrate the pumping action achieved by the combs 134. Fluid duct F has a base portion 136 of substantial thickness in order to provide strength for the pumping chamber 106 during compression. Base portion 136 has a contoured surface portion 138. Wall portion 132 extends in continuous and uninterrupted manner from the opposite ends of contoured surface 138 to form therewith an oval, or elliptical, fluid duct 140. It can be noted in FIG. 3 that the wall portion 132 is relatively thin in comparison with base portion 138. We have found that the wall portion 132 can be made thinner than would be possible with conventional round tubing because of the additional support provided by base portion 136. Therefore, because the wall portion 132 is thinner, it can then be compressed with less force, thereby conserving energy. Furthermore, the curvature of wall portion 132 is such that there is a tendency to collapse inwardly in a uniform way.
Each of the movable combs 134 has a contact surface 142 which has a contour substantially corresponding to that of the surface 138. In this way, the contact surface 142 causes the wall portion 132 to compress into substantial conformance with surface 138 as the combs 134 move toward the base portion 136. Preferably, the cams 92 and 94 are sized so as to prevent the wall portion 132 from engaging the contoured surface 138, as best shown in FIG. 5, upon the shoe 82 completing its compression stroke. We have found that this slight gap prevents blood cells from being crushed, and thereby destroyed. The pump unit U can therefore be conveniently used for pumping whole blood without fear of damage to the cells.
The control schematic for the control unit C is best shown in FIG. 10. A central controller is in electrical connection with a motor drive controller which causes the motor 74 to operate. A disk 200 is carried by the shaft of motor 74 and has a pair of slots 202 and 204. A similar disk 206 is carried by shaft 60 and likewise has slots 200 and 210. The disks 200 and 200 rotate with the associated shafts and are used to provide an indication of rotation of the related components.
A radiation emitter 212, which includes the well known LED, illuminates a radiation detector 214 upon one of the slots being appropriately aligned. Naturally, during rotation, then the disks themselves block the radiation and thereby indicate that rotation is occurring. Should the detectors be illuminated, then an indication of a selected rotational amount is provided for the central controller. This rotation indication is used to monitor the pumping per unit time, particularly useful since the pump volume is known.
FIG. 10 also illustrates the connection of the. video display with the central controller. The video display may include the well known CRT display, or other similar displays well known to those skilled in the art. The video display cooperates with the key board, as previously described, in order to input operating parameters into the central controller which are used to cause rotation of the motor 74, and thereby linear movement of the shoe 82.
The pump system P may also include an infiltration detector in electrical connection with the central controller. It is well known that infusion patients may suffer a piercing of the vein. Should the vein be pierced, then the medicament flows into the surrounding muscle tissue, rather than into the vein for being carried by the bloodstream.
An air in line detector, a pressure monitor, a skin temperature monitor and a down line pressure monitor are also in circuit connection with the central controller. The pressure monitor is, preferably, based upon the capacitance principle. The skin temperature monitor is used to measure infusion shock, while the down line pressure monitor looks at the vein pressure.
A drop counter, based upon the above described radiation emission and detection principle, is applied to the drip chamber 104. Naturally, it should be obvious that a given number of drops per unit time are required to supply the appropriate quantity of fluid.
A door latch detector is provided by radiation emission source 216 which illuminates detector 218. In this way, the central controller can be assured that the door 50 of each pump unit U is closed, and thereby secured, so that operation can continue.
FIG. 10 also indicates the backlight which is advantageously positioned within the housing 48 to provide illumination so that the operator can monitor the fluid duct F. Also indicated in FIG. 10 is the alarm for the control unit C.
OPERATION
Operation of the infusion pump system P of FIG. 1 is straightforward. A pump unit U is slid into one of the chambers 12 or 14. The tube 24 carrying the medicament is then inserted into the inlet opening 116 of the administration set A. The door 50 is then closed and secured by rotation of handle 122.
The appropriate pump unit U is selected from module 40 by depressing the appropriate push button 42, 44 or 46. The video display 28 then transmits a number of "lead through" prompts requesting that information be input through any one of the keys of keyboard 30. The central controller employs an algorithm which makes certain that the appropriate operating information and parameters are input, and thereby avoids the need for extensive training for a particular infusion system. The central controller algorithm makes sure that adequate information is received to permit proper operation, and then monitors operation of the infusion pump system P to make sure that those parameters are maintained.
The pumping volume defined by the fixed shoes 130 is known and is constant. Therefore, rotation of the shaft 60 assures that a known quantity of fluid is pumped to the patient through cannula 128. It should be obvious that a given number of strokes per unit time will be required to pump a selected quantity of medicament in like unit time. Preferably, the pumping volume defined by the fixed combs 130 is 0.002 ml. The central controller permits the operator to select a given volume per unit time from between 0.1 to about 2000 ml/hr. Furthermore, the pump system P can be programmed for a specific volume of medicament at predetermined times over an extended period.
As noted, the pump system P is, preferably, battery powered and has sufficient battery life for 1,000 hours at a medicament rate of 125 ml/hr. This extended battery life is attained because of the ability to turn the motor 74 off when pumping is not reuired. The ratchet pawl 70 prevents the shaft 60 from counterrotating and acts as a brake for maintaining the pump shoe 82 in a fixed position relative to the fluid duct F. Because the motor can be turned to the off position, then battery life is maintained and, just as importantly, pumped medicament can not flow backwardly into the pumping volume during the off stroke. Although a ratchet pawl 70 is disclosed, those skilled in the art will understand that further positive brake apparatus are known, it merely being required that the pump shoe 82 remain in a fixed position without requiring external power.
The pump unit U is particularly advantageous with viscous solutions because of the purge effect which can be achieved. The fluid duct F is vertically disposed within the housing 48 so that the inlet opening 112 is disposed above the outlet opening 126. Any air which may become entrained in the fluid which flows into the pumping chamber 106 will have a tendency to rise upwardly toward duct 110. During the initial stage of the pumping stroke, as known from linear displacement of the shoe 82, then the valve 78 may remain slightly open, as shown in FIGS. 8 and 9, from the fully compressed state of FIG. 2, thereby permitting any entrained air to be pumped upwardly into the drip chamber 106. Naturally, the valve 78 will be fully closed for the majority of the pumping stroke so that the pumping volume can remain fixed.
The pumping cycle is such that the valve 84 closes while the pump shoe 82 retracts upon achieving full compression. The valve 78 simultaneously begins to open in order to permit-the generated vacuum to pull fluid from the drip chamber 104 into the pumping chamber 106. At the selected time, then the valve orientation reverses and the shoe 82 begins to move linearly toward door 50, to therefore force the fluid within the pump chamber 106 to be expelled through the outlet 126. This pumping is very efficient because of the relative thinness of the wall portion 132 of the fluid duct F. Because of this relative thinness, then the compression occurs easily without requiring excessive force.
While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, uses and/or adaptations of the invention, following in general the principle of the invention, and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the central features hereinbefore set forth, and fall within the scope of the invention of the limits of the appended claims.
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A modular infusion pump system utilizes a positive displacement pump for pumping a known quantity of fluid for each stroke. A plurality of longitudinally spaced apart fixed combs cooperate with a resilient tube to define a known pumping volume. A plurality of movable combs are interdigitated with the fixed combs and are periodically linearly directed to cause the pump volume to be compressed, and therefore the fluid expelled. A rotary to linear drive system is connected with the movable combs and a ratchet system prevents counterrotation when the motor is in the off position. Valves are disposed above and below the pumping unit to appropriately seal off the pumping volume. The valves and the movable combs are operated by means of cams carried by a common shaft.
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This is a continuation of application Ser. No. 458,905, filed Apr. 8, 1974, now abandoned.
FIELD OF THE INVENTION
This invention relates to ice-cutting apparatus, and more particularly, is concerned with a comminuting ice-cutter mechanism for vessels operating in arctic waters.
BACKGROUND OF THE INVENTION
With the increased interest in utilizing oil, gas and other resources in the arctic regions of the earth, there has developed a need for improved equipment for operating in ice-covered waters. For example, in Patent No. 3,768,428 there is described a marine vessel with rotary type ice-chipping equipment mounted on the bow of the vessel for cutting a channel through the ice. In such an arrangement, rotating cutter blades shear off or chip away fragments of ice from the ice sheet at relatively high speed to form an open channel through the ice sheet.
Studies of the shearing action taking place as the cutter blades are driven through the ice to cut away the chips and larger pieces of ice from the face of the ice sheet indicate that the cutting action involves forming a fracture ahead of the cutting edge, followed by a wedging apart of the ice along the fracture to separate the ice chips from the ice sheet. The separation of the ice along the fracture by the wedging action of the high speed cutter momentarily produces a void into which water or air must move to equalize the pressure with the surrounding ambient condition. Thus a pressure drop exists which tends to resist the separation of the ice particles along the cleavage. It has been found that a substantial amount of energy is dissipated by the cutters in overcoming the result of this partial vacuum effect produced at the moment the cleavage takes place between each particle of ice as it is removed from the ice sheet by the cutters.
SUMMARY OF THE INVENTION
The present invention provides a more efficient ice cutter of the comminuting type. This is accomplished by providing a mechanism for more rapidly equalizing the pressure at the point of cleavage between the ice being removed by the wedging action of a cutter and the ice sheet. This mechanism utilizes means for injecting fluid, such as water or air under pressure, at the point of cleavage from behind the cutter so as to dissipate the partial vacuum and change it into a positive pressure which aids the separation and removal of the chips by the cutters. This is accomplished, in brief, by providing fluid passages through the cutters which open adjacent the cutting edge of the cutters, and providing a flow of fluid under pressure through the passages for discharge into the space ahead of the cutters as they move through the ice.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the invention, reference should be had to the accompanying drawings, wherein:
FIG. 1 is an elevational view of a monopod drilling platform incorporating an ice cutter;
FIG. 2 is a cross-sectional view taken substantially on the line 2--2 of FIG. 1;
FIG. 3 is a perspective view showing details of the cutter arms;
FIG. 4 shows an alternative embodiment of the invention; and
FIG. 5 is a top view of the cutter arrangement of FIG. 4 with a modified arrangement for injecting fluid into the cutting region.
DETAILED DESCRIPTION
In copending application Ser. No. 459029, and now Pat. No. 3894504, filed Apr. 8, 1974, entitled "Ice Cutter for Monopod Drilling Platform", assigned to the same assignee as the present invention, there is described in detail a drilling platform of the type shown in FIG. 1. The drilling platform includes a base 10 in the form of a hull constructed of bulkheads and outer plates providing a substantially watertight structure which may be ballasted to rest on the sea bottom at the drilling location or which may be sufficiently buoyant to float beneath the surface as a semi-submersible. A superstructure 12 providing an upper drilling deck 14 is supported above the water surface from the base 10 by a single vertical column indicated generally at 16. Drilling is accomplished from the drilling deck 14 down through the column and base into the sea floor by means of conventional drilling equipment including a drilling derrick 18 mounted on the drilling deck 14. As shown in the cross-sectional view of FIG. 2, the column consists of a outer stationary cylindrical shell 20 which is rigidly attached at its lower end to the bottom of the base 10. Inside the column 16 is a cylindrical casing 22 through which access to the ocean floor from the drilling deck is provided. The opening through the casing is referred to as the "moon pool". The casing 22 is preferably offset from the outer stationary cylinder 20 to provide a larger working space for men and equipment between the drilling deck and the subsurface base.
Surrounding the outside of the cylinder 20 and concentric therewith, is a cylindrical sleeve 24. The sleeve 24 is rotatably supported and driven from the upper superstructure 12 to permit continuous rotation of the sleeve 24 around the outside of the cylinder 20. Individual cutter arms 26 are secured to the outer surface of the sleeve 24. The cutter arms are positioned around the complete circumference of the sleeve 24 and are positioned vertically substantially the full length of the column 16.
Referring to FIG. 3, the individual cutter arms 26 are shown in more detail. The cutter arms are forged or otherwise shaped of high-tensile strength material with a base portion 28 which rests against the outer surface of the sleeve 24. The sleeve 24 is provided with a plurality of axially spaced ribs 30. The base 28 of the arm 26 extends between two adjacent ribs. Opposite ends of the base 28 terminate in flanges 32 and 34 which are bolted or otherwise anchored respectively to two adjacent ribs 30 of the sleeve 24.
The arms extend radially outwardly from the base 28, the outer end of the arms 26 curving in an arc so that the outer end 36 is almost tangential to the circular path of movement of the cutter tip. The end 36 is formed with a sharp cutting edge 38. The wedge-shaped cutting edge 38 is formed by a flat surface 40 machined on the outer periphery of the tip 36 of the arm 26. Thus as the sleeve 24 is rotated about a vertical axis in the direction indicated by the arrow in FIG. 3, the cutting edge 38 operates to fracture and dislodge large chunks of ice from the surrounding ice sheet.
As pieces of ice are dislodged by the wedging action of the tip 36 when the edge 38 penetrates into the ice sheet, a void is momentarily produced between the cleavage surfaces. There is therefore a pressure drop existing momentarily which tends to resist the separation of a piece of ice from the ice sheet along the cleavage. Air or water must flow in behind the piece of ice to equalize the pressure between the cleavage surfaces. In order to equalize the pressure more rapidly and thereby reduce the force required to dislodge the pieces of ice by the cutter arms, fluid under pressure is directed at the point where the ice fracture is formed, namely, at the cutting edge 38. To this end, in the embodiment shown in FIG. 3, fluid under pressure is discharged through an opening 42 in the surface 40. The opening 42 is formed by a passage 44 in the cutter arms 26 which extends from the opening 42 through the arm to the base 28. Preferably the opening in the base 28 communicates with an opening through the sleeve 24 so that, by pressuring the annular space between the inside of the sleeve 24 and the supporting column, water is forced out through the passages 44 on those cutter arms below the water level while air is forced out through those cutter arms positioned above the water level. Suitable sealing means, such as the nylon bearings at either end of the sleeve 24, described in the above-identified copending application, close off the annular space at either end of the sleeve permitting the annular space to be maintained at an elevated pressure by pumping water or air into the annular space. For ease of manufacture, it will be noted that the passage 44 is formed of two straight sections, permitting the bore to be formed by conventional machine drilling techniques.
Referring to FIG. 4 there is shown an alternative type of ice cutter such as described in U.S. Pat. No. 3,768,428, assigned to the same assignee as the present invention. In this cutter arrangement a pair of oppositely rotating interleaved cutters are provided. Thus a plurality of spaced rotary cutters 52 are mounted on a shaft 54 and are interleaved with a group of rotary cutters 58 mounted on a shaft 60. The two counterrotating shafts 54 and 58 are driven from a motor 62 through a transmission drive 56. The entire cutter assembly is supported on a frame member 64 in a manner described in detail in the above-identified patent.
To provide the features of the present invention, the shafts 54 and 60 are provided with axially extending bores 66 and 68, respectively. These central bores are connected to a conduit 78 from a source of water under pressure (not shown) through conventional rotary couplings on the ends of the shafts 66 and 68. Each of the cutters 52 and 58 in turn is provided with internal passages, such as indicated at 74 and 76, the passages leading from the central bores 66 and 68, respectively, to openings on the outer periphery of the cutters 52 and 58 immediately adjacent the cutting edges of the cutters. Thus water (or air) under pressure connected to the conduit 70 is discharged at the point of cleavage and separation of the ice particles by the respective cutters.
An alternative arrangement is shown in FIG. 5 in which cutters 52' and 58' are interleaved and rotated by shafts 54' and 60', respectively, in the same manner as described above in connection with FIG. 4. However, in place of the fluid discharge at the cutting edges of each of the cutters, pressurized fluid is discharged adjacent the ice engaging region of the cutters by means of a vertically extending pipe 80 adapted to be connected at a pressurized fluid source (not shown), the pipe serving as a manifold having a plurality of discharge pipes, two of which are indicated at 82 and 84, respectively, which project radially into the openings between the shafts 54' amd 60' formed by the interleaved cutters. These discharge pipes 82 and 84 terminate in nozzles 86 and 88, respectively, for directing fluid tangentially along the outer perimeter of the respective cutters 52' and 58'. One such discharge pipe and nozzle is provided for each of the vertically spaced interleaved cutters. The vertical pipe 80 is connected to a suitable source of fluid, such as water or air, under high pressure. The discharge of fluid under pressure adjacent each of the cutters where the cutting edge engages the ice permits the partial vacuum at the cleavage interface produced by the cutting edges moving through the ice to be dissipated more rapidly, increasing the cutting efficiency.
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There is described a comminuting type ice cutter for use with vessels operating in ice-covered waters. Fluid, such as water or air, is injected into the region of each cutter edge to break the partial vacuum which is created at the cleavage interface of the ice fragments as they are broken away from the body of ice by the cutting or wedging action of the cutters. The fluid is introduced by passages extending through the cutter blades and opening adjacent the cutter edges. Alternatively the fluid may be forced into the cutting region by separate jets which may be either stationary or may rotate with the blades.
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BACKGROUND OF THE INVENTION
(a) Field of the Invention
The invention relates to a method of preparing a cored wire suitable for use in coating metallic articles which are exposed to erodent particles. In particular, the invention relates to deposition of an erosion resistant coating which is comprised of larger ferroboron phases bound with a ductile metallic phase, said ductile metallic phase having a low affinity for oxygen.
(b) Description of the Prior Art
Solid particle erosion is defined as the progressive loss of material from a solid surface that results from repeated impact of solid particles. Solid particle erosion is to be expected whenever hard particles are entrained in a gas or liquid medium impinging on a solid at any significant velocity, generally greater than 1 m/s. Manifestations of solid particle erosion include thinning of components, a macroscopic scooping appearance following the gas-particle flow field, surface roughening which severity depends on particle size and velocity, lack of directional grooving characteristic of abrasion and, in some cases, the formation of ripple patterns.
The distinction between erosion and abrasion should be clarified, because terms are very often misunderstood and situations not adequately classed. Solid particle erosion refers to a series of particles striking and rebounding from the surface, while abrasion results from the sliding of abrasive particles across a surface under the action of an externally applied force. The clearest distinction is that, in erosion, the force exerted by the particle on the material is due to their deceleration, while in abrasion it is externally applied and constant.
Therefore, erosion is affected by three types of variables: impingement variables describing the particle flow (velocity, impingement angle and particle concentration), particle variables (particle shape, size, hardness and friability) and material microstructure. The velocity of erodent has a marked influence on the rate of material removal. It is generally admitted that the rate of erosion exponentially (the exponent being between 2 and 2.5 for metals and 2.5 and 3 for ceramics) increases with the velocity. Angular particles produce erosion rates higher than rounded ones. The hardness of erodent particles relative to the material being eroded should be considered.
Depending on their nature, materials have a different response to erosion. Material removal in ductile material involves large plastic flow while, in ceramics fracture is of primary importance, particularly for higher incidence angles. Solid particles impacting metals form plastic impact craters and displace material. At low incidence angles, the displaced material is thereafter cut and removed by a mechanism known in the scientific literature as "platelet mechanism". Metallic materials present higher erosion rate at low impact angle than at high impact angle. Conversely, ceramics are more damaged at high impact angles than at low impact angles and present erosion peak at 90°. In their case, the mechanism of material removal involves cracks initiated by brittle fracture for erosion at normal incidence angle.
Thus, for particles impacting at low velocity hard materials are usually considered at low impact angle but elastic materials should be selected at high impact angle. For higher particle velocity hard materials with some toughness are selected for low impact angle and resilient materials showing a compromise between strength and ductility are chosen for high impact angles. Resilience is required to resist penetration of the surface by impacting particles. Therefore, the selection of materials to resist erosion depends on the angle at which the particles strike the surface and the impact velocity.
Two-phase materials such as high chromium white cast irons and Stellites might be expected to exhibit high erosion resistance. It could be expected that such alloys could combine the relatively good erosion of hard ceramic phase with the desirable ductility and toughness of a metal. Though these alloys provide excellent abrasion resistance, under most erosion conditions they exhibit little or no improvement over plain carbon steels or pure metals. There is a synergetic increase of the erosion of hard and brittle phase by its presence as a dispersed phase in a relatively soft metal matrix. As an example, the eroded surface of white cast iron by quartz sand shows that primary carbide are deeply depressed below the surface.
Erosion is considered as a serious problem in many engineering systems such as steam and jet turbines, pipelines and valves carrying particulate material and fluidized bed combustion systems. Generally speaking, machinery for use in processing and transportation of fluids containing solid particles are exposed to damage resulting from erosion. Processing machines for processing resins containing glass fibers, carbon fiber, asbestos or iron oxide; slurry pumps for fluid transportation of ore or coal; pipelines for transporting slurries and so forth are examples of industrial machinery that are damaged by solid particle erosion.
Particularly, high-temperature fluidized bed metal components exposed to temperatures up to 500° C. and process fans that aspirate gas having temperatures that reach 350° C. suffer extensive material wastage. Heat exchanger tubes in fluidized bed combustors experienced relatively high wastage rate at low temperature (250° C.). The wastage rate increases with the temperature and the particle velocity. Peak wastage rates are observed for 347 stainless steel at 450° C., for Incoloy 800H at 450° C., for mild steel at 300° C., for 1Cr-0.5Mo steel at 400° C., for 2.25Cr-1Mo at 400° C., for 722M24T steel at 400° C. At temperatures above 100° C., erosion enhances oxidation. The wastage involves the formation and removal of oxide by impacting particles. At these temperatures, thin oxide layers are formed at much greater rates than would be the case during static oxidation. Impacting particles repeatedly take off thin oxide layers, the exposed metallic surface being readily oxidized. Therefore, in these conditions, erosion accelerates the oxidation of materials.
In process fans used in pelletizing plants to re-circulate hot gas containing iron ore particles, the same type of wastage is observed. Iron ore pellets are sintered in continuous large industrial oil-fired furnaces. From the furnace, large volumes of hot gas are sucked by powerful fans. Being exposed to gas-borne iron particles and temperatures ranging between 125° C. and 328° C. fan components are rapidly deteriorated. Extensive part repair or replacement are required for maintaining a profitable operation.
Cobalt- and nickel-bonded tungsten carbide coatings as well as nickel-bonded chromium carbide have been widely adopted in various applications because of their wear resistance. Unfortunately, these coatings are applied using expensive high velocity oxy-fuel and plasma spraying techniques. In addition, these coating techniques are not suited for on-site applications, particularly in restricted areas. These materials contain strategic, price-sensitive elements such as nickel, chromium and tungsten and/or do not necessarily offer the best erosion resistance in applications mentioned above. These elements (WC) are either strategic or scarce, so that the carbide materials are price sensitive. In addition, elements contained within these materials present some toxicity restricting their use in some applications, requiring expensive health protection equipment and limiting personnel exposure to toxic dust.
There are many workers that have previously proposed materials based on iron and iron borides for different applications.
Kondo, Okada, Minoura and Watanabe in (U.S. Pat. No. 3,999,952) (1976) proposed a method to produce a sintered hard alloy, prepared from a hard alloy powder comprising iron boride or iron multiple boride in which a part of iron boride is substituted by a non-ferrous boride or multiple boride.
In a subsequent patent (U.S. Pat. No. 4,194,900) (1980) Ide, Takagi, Watanabe, Ohhira, Fukumori and Kondo proposed a modification in the method for producing the hard alloy powder by using different raw materials for improving strength and hardness. In these works, hard alloys are produced by crushing the hard alloy powder, pressing the milled powder and sintering the compact under vacuum or controlled atmosphere.
Ide, Kawamura, Ohhira, Watanabe and Kondo in Jap. Pat. No. Sho (1983)-101622 proposed a method of using hard sintered alloys of the iron-based complex series in combination to form paired metals. The hard phase of these alloys contains 35-96 wt. % iron-based complex boride with the remaining consisting of one or more of Cr, Fe, Mo, W, Ti, V, Nb, Ta, Hf, Zr, Ni, Co, Mn or the alloys of these metals to form the bonding phase. Sliding wear properties of the sintered alloys against metals were evaluated using the Ohgoshi sliding wear tester.
Watanabe, and Shimizu in U.S. Pat. No. 4,259,119 (1981) proposed a sintered body suitable as abrasive material comprising 70 to 99.99% of a combination of at least two kinds of metal borides selected from the group consisting of diborides of Ti, Ta, Cr, Mn, Mo, Y, Hf, Nb, Al and Zr and from 0.01 to 30% by weight of a metal boride or borides selected from the group consisting of borides of nickel, iron and cobalt.
Watanabe and Kono in U.S. Pat. No. 4,292,081 (1981) proposed sintered refractory and abrasive bodies composed of titanium diboride, chromium diboride, tantalum diboride with minor amounts of metal borides such as MnB, Mn 3 B 4 , Mn 2 B, Mn 4 B, TiB, Ti 2 B 5 , W 2 B 5 and Mo 2 B 5 . In the preparation of sintered bodies iron boride, nickel borides and cobalt borides are also added to favour liquid phase sintering. Watanabe et al. in U.S. Pat. No. 5,036,028 proposed a high density metal-boride based ceramic sintered body composed of at least: a) TiB 2 , ZrB 2 , CrB 2 , HfB 2 , VB 2 , TaB 2 , NbB 2 , MoB 2 , YB 2 , AlB 2 , MgB 2 , CrB, VB, TaB, NbB, MoB, HfB, YB, ZrB, HfB, TiB, MnB, W 2 B 5 and Mo 2 B 5 ; b) 0.1 to 10 wt. % of cobalt boride, nickel boride or iron boride and c) 0.1 to 10 wt. % of a double carbide comprising Ti, Zr, Wand C, ZrCN, HfCN or a double carbo-nitride comprising Ti, Zr, Hf and C,N.
Jandeska and Rezhets in U.S. Pat. No. 4,678,510 (1987) proposed a wear resistant iron alloy article formed by compacting and sintering a predominantly iron powder mixture containing additions of C, Cu and nickel boride. The product microstructure comprises hard borocementite particles dispersed in a martensitic or pearlite matrix. The particles have a cross-sectioned dimension greater than 1 μm, in an amount preferably between 10 and 30 volume percent to improve the wear resistance. This material was developed for automotive gears.
Saito and Kouji in Eur. pat. No. 0659894A2 proposed a high modulus iron-based alloy comprising a matrix of iron or iron alloy and one boride selected from the group consisting of borides of group Iva elements, and complex borides of group Va element and iron dispersed in the matrix. The iron based-alloy is obtained by sintering at temperature of 1000 to 1300° C. The sintered product is undesirably likely to form liquid phase above 1300° C. In samples 13-15, Fe-17Cr is mixed with ferrotitatium and ferroboron powders.
Miura, Arakida, Kondo and Ide in U.S. Pat. No. 4,427,446 (1984) proposed a wear-resistant composite material for use in centrifugally cast linings. The matrix metal is an oxidation-resistant nickel or cobalt alloy and the reinforcing material is a boride or a composite boride composed of chromium, iron and boron. The matrix used is either a Ni--Cr--B--Si based self-fluxing alloy or a Co--Ni--Cr--W--B--Si based self-fusing alloy. According to the inventors, the self-fluxing properties of alloys which melt at temperature comprised between 950 and 1250° C. is the key point of their process. The cylinder containing a powder mixture comprising the self-fluxing alloy and the reinforcement is first heated to the melting temperature of the alloy. Placed in a centrifuge, the melt is allowed to cool slowly. After cooling, the inner surface is rich in reinforcing particles.
Clark and Sievers in U.S. Pat. No. 4,389,439 (1983) proposed a different lining for tubes and cylinders. They proposed a composite tubing comprising an iron boride layer formed in situ by the diffusion of boron into iron. The diffusion coating obtained has an inner layer comprising dispersed iron carbide and an outer layer consisting of iron boride.
Sanchez-Caldera, Lee, Suh and Chun in U.S. Pat. No. 5,071,618 (1991) proposed a method for manufacturing a dispersion-strengthened material based on a metal matrix with a containing element capable of reacting with boron and a second metal containing metal and boron. The material is produced by injecting the two metal in liquid state at two different speeds. It produces materials containing boride particles having an average size of 0.2 μm.
Dallaire and Champagne in U.S. Pat. No. 4,673,550 (1987) proposed a process for synthesizing TiB 2 composite materials containing a metallic phase. The preparation of these composites comprises providing mixture titanium alloys which in addition contain Fe, Ni, Al, Mo, Cr, Co, Cu or mixtures thereof and boron or ferroboron. After heating, it results in the synthesis of composite material containing fine TiB 2 crystals dispersed in a metallic matrix. Coatings applied by plasma spraying possess excellent abrasion wear resistance.
Jackson and Myers in U.S. Pat. No. 3,790,353 (1974) proposed a hard facing pad usable, for example, by brazing to a digger tooth or the like. The wear pad is from 70 to 85 per cent per volume particles of cemented carbide in a metal matrix having a melting point not substantially higher than the melting point of the metal cementing the carbide.
Tagaki, Mori, Kawasaki and Kato in U.S. Pat. No. 5,004,581 (1991) proposed a dispersion strengthened copper-base alloy for wear resistant overlay formed on a metal substrate consisting in 5-30 wt. % Ni, 0.5-3 wt. % B, 1-5 wt. % Si, 4-30 wt. % Fe, 3-15 wt. % Sn or 3-30 wt. % An, the remaining being copper. It forms boride and silicide of the Ni--Fe system dispersed in a copper-base matrix. This material is expected to provide a superior wear-resistance to slide abrasion as evaluated by the Ohgoshi abrasion tester.
Gale, Helton and Mueller in U.S. Pat. No. 3,970,445 (1976) proposed a wear-resistant alloy comprising boron, chromium an iron having high hardness produced by rapidly cooling and solidifying spheroidal particles of the molten alloy mixture. The resultant particles are cast in the desired form or incorporated into a composite alloy wherein the solid particles are held together with a matrix of different material from the alloy. This alloy was designed for use in abrasive environments (ground-engaging tools). The composite particles comprise 25-61 wt. % chromium, 6-12 wt. % boron and the balance iron and are produced by melting.
Helton, Gale, Moen, Mueller, Pierce and Vermillion in U.S. Pat. No. 4,011,051 (1977) proposed spheroidal particles of wear-resistant alloy comprising boron, chromium and iron with high hardness produced by the rapid cooling of a molten alloy mixture. The resultant solid particles are then incorporated into a composite alloy wherein the solid particles are held together with a matrix of different material from the alloy. Inserts of the alloy are useful in producing long wearing tools. The composite particles contain 25-70 wt. % chromium, 6-12 wt. % boron, 0-2 wt. % carbon, the remaining being iron. One of the brazing alloy consist in 94.0 wt. % nickel, 3.5 wt. % silicon, 1.5 wt. % boron, 1.25 wt. % iron and 0.03 wt. % carbon.
Helton, Gale, Moen, Mueller, Pierce and Vermillion in U.S. Pat. No. 4,113,920 (1978) proposed a ground engaging tool resisting to wear including a contact section for engaging the ground and at least a portion of said section reinforced with a wear resistant alloy, said wear resistant alloy comprising cast spherical of a first alloy embedded in a matrix of a second alloy in which said first alloy is soluble with difficulty and wherein the first alloy comprises from about 25-70 wt. % chromium, from about 6-12 wt. % boron, from about 0 to about 2 wt. % carbon, and iron is the balance. The matrix is a nickel based brazing alloy. Mixed powders are jointed by conventional sintering processes.
Moen in U.S. Pat. No. 4,066,422 (1978) proposed a wear-resistant composite material and method of making an article which is particularly adaptable for use with a ground engaging tool. The composite material comprises abrasive-wear resistant particles embedded in a matrix consisting of about 3 to 5 wt. % boron, and the balance being iron having residual impurities. The boron is controlled to a level of approximately 3.8 wt. % corresponding to the eutectic Fe--B composition which has the low melting temperature of 1161° C.
E. I. Larsen in U.S. Pat. No. 3,720,990 (1973) disclosed a molybdenum alloy containing at least two metallic elements which form an alloy which melts at a temperature considerably below that of molybdenum and when in the molten state dissolves appreciable molybdenum during liquid phase sintering and which may be shaped before or after sintering, thus avoiding expensive hot working and/or hot forging.
Babu in U.S. Pat. No. 4,235,630 (1980) and Can. Pat. No. 1,110,881 (1981) proposed a wear-resistant molybdenum-iron boride alloy having a microstructure of a primary boride phase and a matrix phase. The primary boride phase comprises molybdenum alloyed with iron and boron, and the matrix phase comprises one of boron-iron in iron and iron- molybdenum in iron. The alloy finds particular utility in a composite material on a ground-engaging tool. The alloy is densified by sintering the article at a temperature sufficient for controlled formation of a liquid phase. The molybdenum-iron-boride alloy can be also crushed to form particles that can be bounded by a suitable matrix, such as the iron-boron matrix composition described in U.S. Pat. No. 4,066,422 attributed to Moen. For fabricating the sintered alloy Babu used in examples a preferred ferroboron constituent containing 25 wt. % boron.
Dudko, Samsonov, Maximovich, Zelenin, Klimanov, Potseluiko, Trunov and Sleptsov in Can. Pat. No. 1,003,246 (1977) proposed wear-resistant composite materials for hard facing equipment subjected to abrading. Particulate material containing 7-30 wt. % chromium, 40-60 wt. % titanium and 30-40 wt. % boron having a size between 0.3 to 2 mm are embedded in a low-melting alloy matrix to ensure good wettability. Preferred alloys contain: a) 30-65 wt. % copper, 10-35 wt. % nickel and 10-35 wt. % manganese; b) 12-25 wt. % chromium, 1.5-4 wt. % silicon, 1-4 wt. % boron, the balance being nickel.
Ray in U.S. Pat. No. 4,133,679 (1979) described glassy alloys containing iron and molybdenum or tungsten, together with low boron content. The glassy alloys consist essentially of about 5 to 12 atom percent boron, a member selected from the group consisting of about 25 to 40 atom percent molybdenum and about 13 to 25 atom percent tungsten and the balance iron plus incidental impurities.
The prior art references described above relate to compositions of matter which differ from those of the subject application. Alternatively, the physical properties of the subject invention, namely hard ferroboron phases of relatively large area bound with a ductile metallic phase, provide an erosion resistant coating which is surprisingly superior to prior art coatings.
SUMMARY OF THE INVENTION
An object of the invention is thus to provide a oxidation-resistant and erosion-resistant composite material that is formed by high temperature melting a metal possessing low affinity for oxygen with requisite proportion of ferroboron particles of the required particle size. Raw materials are shaped in the form of a cored wire that is arc sprayed with air or deposited by welding techniques for producing erosion-resistant coatings for components exposed to a high velocity blasts of large particles at temperatures up to 500° C.
The above object is attained by employing a ductile metal having low affinity for oxygen such as iron, low carbon steel or ductile stainless steel with coarse ferroboron particles. The resulting coatings are composed of boride phases having mean sizes at least equal or larger than the sizes of erodent impacts.
Broadly, the invention comprehends an oxidation resistant and ductile metal cementing boride particles which is formed by bringing the metal and boride particles together at temperatures higher than the melting temperature of the metal. The formed material is composed of large hard boride phases bonded by resilient, ductile and oxidation-resistant metallic phases. It can be preferably obtained in the form of erosion-resistant coatings by arc spraying cored wires composed of a sheath of the selected metal and a core comprising only the boride particles.
In particular, the invention comprises a two-phase composite coating having select microstructural features. In preferred embodiments, coatings prepared by the process of the invention will contain hard boride phases bounded with a ductile metallic phase.
In said preferred embodiments, the exposed surface areas of the majority of the hard boride phases will be greater than the mean impacting surface of the erodent particles. Additionally, the ductile metallic phases will, in preferred embodiments, be smaller in exposed surface area than the mean impacting surface of the erodent particles. Such embodiments of the invention will resist erosion by deflection of the erodent particles off of the hard boride phases. Further, the reduced surface area of the ductile metallic phase prevents ploughing of this phase by erodent particles and the plastic deformation which results therefrom.
The inventor has determined that the most damaging iron ore particles typically range in size from 32-300 μm in size and that the mean particle size is 89 μm. It has also been determined that with particles of this size, the mean size of impact in collisions with a relatively smooth surface corresponds to 14.5 μm in maximum length. Accordingly, when the erodent particle is iron ore, the inventor has determined that a preferred embodiment of the invention comprises a two phase coating wherein the surface includes (a) hard ferroboron phases having a surface area which generally corresponds to a geometric area having 14.5 μm in length or greater and (b) a ductile metallic phase which houses the ferroboron phases. The ductile metallic phase must be selected from metals which have a low affinity for oxygen. Further, the ductile metallic phase should have surface exposure in the regions between the ferroboron hard phases having surface area sizes which correspond to circles having diameters less than about 14.5 μm.
It has been determined that coatings having the above-mentioned microstructural properties are most efficiently prepared by arc spraying or deposition by welding techniques. The components of the coating are provided in the form of a cored wire wherein the sheath is composed of the ductile metallic phase and the powdered core is composed of a coarse ferroboride powder. Advantageously, the invention allows for on site deposition of the coating.
DESCRIPTION OF THE DRAWINGS
FIG. 1: Schematic view of a device adapted to simulate accelerated erosion.
FIGS. 2, 3: Graphical representation of the effect of changes in arc voltage on erosive volume loss at 25° C. (FIG. 2) and 330° C. (FIG. 3).
FIGS. 4, 5, 6, 7: Graphical representation of the effect of changes in arc amperage on erosive volume loss at 25° C./31 Volts (FIG. 4), 330° C./31 Volts (FIG. 5), 25° C./35 Volts (FIG. 6) and 330° C./35 Volts (FIG. 7).
FIGS. 8, 9: Graphical representation of the effect of changes in spray distance on erosive volume loss at 25° C. (FIG. 8) and 330° C. (FIG. 9).
FIGS. 10, 11: Graphical representation of the effect of changes in transverse spray speed on erosive volume loss at 25° C. (FIG. 10) and 330° C. (FIG. 11).
FIG. 12: Graphical representation of the effect of changes in the arc amperage on the deposition rate.
FIGS. 13, 14, 15, 16: Graphical representation of the effect of changes in the wire load on the erosive volume loss at 25° C./31 Volts (FIG. 13), 330° C./31 Volts (FIG. 14), 25° C./35 Volts (FIG. 15) and 330° C./35 Volts (FIG. 16).
FIGS. 17, 18, 19, 20: Graphical representation of the effect of changes in the wire load on erosive volume loss at 25° C./25° impact angle (FIG. 17), 330° C./25° impact angle (FIG. 18), 25° C./90° impact angle (FIG. 19) and 330° C./90° impact angle (FIG. 20).
FIG. 21: Scanning electron micrographs of the surface of arc sprayed coatings using cored wire P-3 (400 fold magnification).
FIG. 22: Scanning electron micrograph of a cross-section of an arc-sprayed coating using cored wire P-3 (300 fold magnification).
DESCRIPTION OF PREFERRED EMBODIMENTS
Typically, the invention would be used on site to apply an erosion resistant coating to a surface exposed to erodent particles, such as process fans or heat exchange tubes in fluidized bed combustors. The apparatus depicted schematically in FIG. 1 was designed to simulate an accelerated erosion environment in which to compare the erosion resistance of various coatings. This apparatus allows the evaluation of erosive wear on samples at temperatures up to 500° C. An alumina nozzle (1) having a diameter of 1.575 mm provides a well localized stream of particles. Particle flowrates were selected to avoid particle-to-particle collisions which would result in under evaluation of the extent of erosion. A particle feeder (2) delivers particles to a mixing chamber (3) at a constant rate. The particles are then accelerated toward a coated target (4) by compressed air delivered to the mixing chamber by a coil (5). The target is held in position by an adjustable sample holder (6) which allows for erosion tests at different impact angles. A furnace (7) is provided for testing at elevated temperatures.
To measure erosion at elevated temperatures, the sample holder was introduced into the furnace 5 minutes prior to the introduction of erodent particles for impact angle tests at 90° and 10 minutes prior to impact angle tests at 25°. The compressed air passes through the furnace-heated coil (5) thereby elevating the temperature thereof.
Erodent particles were comprised of oven dried iron ore particles which varied in size from about 32 to about 300 μm.
The measurement of particle speed was done with a laser anemometer and the testing rig calibrated in order to obtain particle impact velocity of 100 m/s. Table 1A gives the main parameters used during erosion tests.
TABLE 1A______________________________________Erosion test parameters______________________________________Erodent material Iron ore (-300 + 32 μm)Erodent flow rate 2.64 (+/-5%)g/minuteErodent impact speed 96.49(+/-22)m/sTesting Time 5 minutesTest temperature (° C.) 25 and 330° C.______________________________________
Wear damage was evaluated with a laser profilometer. This apparatus allows measurements with an accuracy greater than 99%. The profilometer is designed to measure minute volume losses and microscopic deformation. Volume losses are reported in mm 3 per kilogram of erodent particles.
The coatings were deposited on metallic target material by arc spraying a cored wire. The cored wire is comprised of a powdered core enclosed within a drawn metal sheath.
Core powders, comprised of iron, ferroboron or boron or metallic additives were mixed in a tumbler for 24 hours to evenly distribute particles of different sizes through the powder. The composition of each powder and the proportion of particles of different sizes are recited in Table 1B. The composition of metals which were used to prepare sheaths are shown in Table 1C.
TABLE 1B__________________________________________________________________________Chemical Composition and Particle Size Distribution of Powders Particle Size Distribution Composition U.S. Mesh Sieve SizePowder Element Wt. % Size (μm) Wt. %__________________________________________________________________________Atomet 95D Iron 99.56 +200 +75 1.5iron powder Oxygen 0.39 -200 + 325 45 2.5 Carbon 0.05 -325 -45 96.0Atomet 95 Iron 99.79 +200 +75 2.5iron powder Carbon 0.21 -200 + 325 45 7.0 -325 -45 90.5Atomet 1001HP Iron >99 -250 + 150 10iron powder Nickel 0.07 -150 + 106 17 Oxygen 0.06 -106 + 75 20 Chromium 0.05 -75 + 45 25 Copper 0.02 -45 28 Manganese 0.015 Phosphorous 0.01 Vanadium 0.006 Aluminum 0.004 Sulfur 0.004 Carbon 0.004 Silicon 0.003 Titanium 0.001Boron powder Boron 95-97 -5 100(Cerac Inc.) Silicon 0.03 Magnesium 0.2 Iron 0.1 Calcium 0.1 Oxygen BalanceFerroboron 1 Iron 80.149 +100 37(Shieldalloy Corp.) Boron 17.90 +200 36 Aluminum 1.92 +325 14 Carbon 0.03 -325 13 Sulfur 0.001Ferroboron 2 Iron 80.472 +100 34.0(Metallurg Ltd.) Boron 19.00 +200 33 Carbon 0.31 +325 17.0 Silicon 0.20 -325 16.0 Sulfur 0.002 Phosphorous 0.016Ferroboron 3 Iron 80.58 +100 43.0(Metallurg Ltd.) Boron 18.80 +200 35.0 Carbon 0.149 +325 11.0 Silicon 0.46 -325 11.0 Sulfur 0.002 Phosphorous 0.009Ferroboron 4 Iron 81.14 +100 28.0(Metallurg Ltd.) Boron 18.60 +200 38.0 Carbon 0.03 +325 18.0 Silicon 0.21 -325 16.0 Sulfur 0.003 Phosphorous 0.02__________________________________________________________________________
TABLE 1C______________________________________Composition of metals used to prepare the sheath of cored wires. CompositionMetal Element Wt. %______________________________________1074 Steel Carbon 0.740 Manganese 0.670 Chromium 0.220 Silicon 0.210 Nickel 0.020 Phosphorous 0.010 Sulfur 0.002 Iron Bal.1008 Steel Manganese 0.210 Carbon 0.040 Aluminum 0.034 Sulfur 0.012 Silicon 0.010 Phosphorous 0.009 Iron Bal.1005 Steel Manganese 0.2 Carbon 0.03 Sulfur 0.05 Phosphorous 0.04 Iron Bal.304 Stainless Steel Chromium 18.54 Nickel 9.52 Manganese 1.41 Silicon 0.53 Copper 0.36 Molybdenum 0.26 Carbon 0.06 Nitrogen 0.04 Phosphorous 0.03 Sulfur 0.001 Iron Bal.430 Stainless Steel Element 16-18 Chromium 1.0 Manganese 1.0 Silicon 0.12 Carbon 0.04 Phosphorous 0.03 Sulfur Bal. IronA-1 Kanthal Alloy Element 22 Chromium 5.8 Aluminum Bal. Iron______________________________________
In a preferred embodiment of the invention, the metal sheath of the cored wire is derived from a metal strip which is about 0.254 or 0.127 mm thick and about 10.16 mm wide. The metal strip is drawn through a series of standard wire drawing dies aligned in descending order of diameter on the orifice. At the stage where the metal strip forms a "U" shape, a powdered mixture is introduced into the "U" shaped metal channel. The metal strip is then drawn through additional standard dies which seal the edges of the strip with an overlapping joint. The cored wire is then drawn to a final diameter of about 1.60 mm to achieve favourable compacting of the enclosed powder.
Arc spraying experiments were carried out with the above-described wires using a commercial Miller BP 400* Arc Spray System under ambient atmosphere. Coatings can be obtained by spraying with different gases as the atomizing gases. Air was preferred because of its availability and low cost.
For all experiments, the spraying conditions are indicated in Tables 3, 4 and 9-15. Voltage mentioned was almost stable during the arc spraying operation. For comparison purposes, arc sprayed coatings were also fabricated by spraying commercial wires. Their erosion resistance was evaluated by the same *Trade-mark method that was used with cored wires prepared according to the invention.
EXAMPLE 1 to 46, P-1 to P-6
The powder mixtures required for forming the core of the wires were blended in a tumbler for 24 hours. The resulting powder mixtures were each loaded in a metal strip to form after cold drawing a 1/16 inch (1.6 mm) diameter cored wire. One wire sample was cold drawn to 2.3 mm. The cored wires containing a loading percentage of the powder mixture were arc sprayed to form thick coatings. The coatings were erosion-tested using the blast type device depicted in FIG. 1 using iron ore as erodent. The volume loss was measured with the laser profilometer. The composition of cored wires for the different examples are shown in Table 2, the spraying parameters in Tables 3 and 4; the results of erosion tests expressed in mm 3 per kilogram of iron ore striking the material are shown in Tables 5 and 6.
TABLE 2__________________________________________________________________________Composition and characteristics of cored wire samples Sheath material/ Core Core thickness Core wt %/ Core wt % WireWire (thousand of wt %/iron ferroboron wt % other loadingsample an inch) type type boron elements (wt %)__________________________________________________________________________ 1 1074/0.005 70.92/ 24.66/ferroboron 1 4.42 -- 51.2 Atomet (-15 μm) 1001HP 2 1074/0.005 91.2/Atomet -- 8.8 -- 50.9 1001HP 3 1074/0.005 -- 60/ferroboron 1 -- -- 49.3 (-100 + 38 μm) 40/ferroboron 1 (-15 μm) 4 1074/0.005 88/Atomet 12 -- 44.4 1001HP 5 1074/0.005 20/Atomet 48/ferroboron 1 -- -- 51 .9 95 (-100 + 38 μm) 32/ferroboron 1 (-15 μm) 6 1074/0.005 40/Atomet 60/ferroboron 1 -- -- 42.9 95 (-15 μm) 7 1074/0.005 94/Atomet -- 6 -- 53.6 1001HP 8 1074/0.005 48/Atomet 48/ferroboron 1 2 -- 47.7 95 (-75 + 38 μm) 9 1074/0.005 40/Atomet 36/ferroboron 1 -- -- 51.5 95 (-100 + 38 μm) 24/ferrbboron 1 (-15 μm)10 1074/0.005 15/Atomet 85/ferroboron 1 -- -- 50.6 (-15 μm)11 1074/0.005 60/Atomet 40/ferroboron 1 -- -- 52.4 95 (-15 μm)12 1074/0.005 20/Atomet 80/ferroboron 1 -- -- 44.52 95 (-38 μm)13 1074/0.005 45.6/Atomet 50/ferroboron 1 4.4 -- 37.4 95 (-38 μm)14 SS 304/0.005 44.14/ 55.86/ferroboron 1 -- -- 39.7 Atomet 95 (-15 μm)15 SS 304/0.005 91.2/Atomet -- 8.8 -- 53.8 1001HP16 1074/0.005 91.2/Atomet -- 8.8 -- 41.3 1001HP17 1074/0.005 66/Atomet -- 9 25 Cr 39.2 9518 1008/0.01 -- 100/ferroboron 1 -- -- 31.6 (-38 μm)19 1074/0.01 -- 100/ferroboron 1 -- -- 44.2 (-38 μm)20 1008/0.01 -- 99.6/ferroboron 1 -- 0.4 C 31 (-38 μm)21 1008/0.01 20/Atomet 80/ferroboron 2 -- -- 33.3 95D (-75 μm)22 1008/0.01 35/Atomet 65/ferroboron 2 -- -- 39.2 95D (-150 μm)23 1008/0.01 -- 100/ferroboron 2 -- -- 40.6 (-150 μm)24 1074/0.01 35/Atomet 65/ferroboron 2 -- -- 29.3 95D (-75 μm)25 1074/0.01 20/Atomet 80/ferroboron 2 -- -- 34.4 95D (-150 μm)26 1074/0.01 -- 100/ferroboron 2 -- -- 37.13 (-150 μm)27 1008/0.01 -- 100/ferroboron 2 -- -- 41.3 (-150 + 32 μm)28 1008/0.01 20/Atomet 80/ferroboron 2 -- -- 35.9 95D (-150 + 32 μm)29 1008/0.01 -- 160/ferroboron 2 -- -- 42.430 1008/0.01 -- 100/ferroboron 2 -- -- 42.6 ( +32 μm)31 1008/0.01 -- 100/ferroboron 3 -- -- 42.3 (-150 + 32 μm)32 1008/0.01 -- 98/ferroboron 2 2 -- 37.333 S.S. 430/0.01 -- 100/ferroboron 3 -- -- 41.834 1008/0.01 -- 96/ferroboron 3 -- 4 Sn 37.835 1008/0.01 -- 100/ferroboron 4 -- -- 33.936 1008/0.01 -- 100/ferroboron 4 -- -- 43.837 S.S. 304/0.01 -- 100/ferroboron 4 -- -- 40.839 Kanthal -- 100/ferroboron 3 -- -- 38.3 A-1/0.0140 1008/0.01 -- 100/ferroboron 2 -- -- 46.541 1008/0.01 -- 100/ferroboron 2 -- -- 41.642 1008/0.01 -- 100/ferroboron 2 -- -- 38.743 1008/0.01 -- 100/ferroboron 2 -- -- 34.844 1008/0.01 -- 100/ferroboron 2 -- -- 29.245 1008/0.01 -- 100/ferroboron 2 -- -- 25.6P-1 1005/0.01 -- 100/ferroboron 2 -- -- 35.27 (-150 + 32 μm)P-2-A 1005/0.01 -- 100/ferroboron 3 -- -- 38.75 (-150 + 32μm)P-2-B 1005/0.01 -- 100/ferroboron 3 -- -- 38.3 (-150 + 32 μm)P-2-C 1005/0.01 -- 100/ferroboron 3 -- -- 37.63 (-150 + 32 μm)P-3 1005/0.01 -- 100/ferroboron 3 -- -- 39.5P-5 1005/0.01 -- 100/ferroboron 3 -- -- 37.4P-6 1005/0.01 -- 100/ferroboron 4 -- -- 34.946 1008/0.01 -- 100/ferroboron 2 -- -- 48.2 wire diameter 2.3 mm__________________________________________________________________________
TABLE 3______________________________________Spraying parameters of cored wires. TransverseCored wire Arc voltage Arc current Spray distance spray speednumber (V) (A) (cm) (cm/s)______________________________________1 27.5 100 10.2 302 27.5 105 10.2 303 29 100 10.2 304 27.5 100 10.2 155 29 100 10.2 156 29 100 10.2 157 29 100 10.2 158 29 100 10.2 159 29 100 10.2 1510 30.5 100 10.2 1511 29 100 10.2 1512 29 100 10.2 152-12 29 100 10.2 1513 29 100 10.2 1514 30 100 10.2 1515 33 100 10.2 1516 30 100 10.2 1517 30 100 10.2 1518 30 100 10.2 1519 30 100 10.2 1520 30 100 10.2 1521 30 100 10.2 1522 30 100 10.2 1523 30 100 10.2 1524 30 100 10.2 1525 30 100 10.2 1526 30 100 10.2 1527 30 100 10.2 1528 30 100 10.2 1529 30 100 10.2 1530 30 100 10.2 1531 30 100 10.2 1531 31 150 7.62 1532 30 100 10.2 1533-1 30 100 7.62 1533-2 35 200 7.62 1533-3 31 200 7.62 1534 30 100 7.62 1535 31 200 7.62 1536 31 200 7.62 1537-1 31200 7.62 1537-2 35 200 7.62 1539-1 31 200 7.62 1539-2 30 100 7.62 1546 35 ˜225 7.62 15Pilot 31 200 7.62 152-A,B,CP-3 31 200 7.62 15P-6 31 200 7.62 15______________________________________
To investigate the effect of arc current, spray distance and transverse spray speed on the resultant coatings, one cored wire embodiment of the invention (P1) was deposited under different spraying conditions (Table 4). The erosion rates for these coatings are shown in Table 5. The results demonstrate that an increase in arc current and hence an increase in the deposition rate produces a coating with improved erosion resistance. A reduce spray distance also improves the coating. In preferred embodiments, the spraying distance will be maintained at about 7.5-10.5 cm. The transverse spray speed does not significantly affect the properties of the coatings. Additional results of erosion volume loss under varied spraying conditions are reported in Tables 9-15. The results, represented graphically in FIGS. 2-12 confirm that coatings done with high arc voltage and amperage, low spray distance and low transverse spray speed resulted in low volume loss at both impact angles of 25° and 90° and temperatures of 25° C. and 330° C. The effect of wire load is shown in Tables 14 and 15 and is represented graphically in FIGS. 13-20. The eroded volume loss of sprayed coatings decreased as the wire load increased for all the erosion conditions tested. FIG. 21 comprises two scanning electron micrographs of a surface that has been coated with embodiment P-3 of the invention. Scanning electron micrographs of cross-sections of a coated surface are shown in FIG. 22. These figures show that coatings presented ferroboride phases (shown in dark contrast) larger than the mean particle impact damage size of 14.5 mm.
TABLE 4______________________________________Spraying parameters for pilot cored wire (P-1). Spray TransverseCoating Arc voltage Arc current distance spray speeddesignation (V) (A) (cm) (cm/s)______________________________________P1-01 30 100 10.2 15P1-02 30 100 20.3 60P1-03 32 100 10.2 60P1-04 32 100 20.3 15P1-05 31 150 7.62 15P1-06 31 150 15.24 30P1-07 31 200 7.62 30P1-08 31 200 15.24 15P1-09 31 200 7.62 15______________________________________
TABLE 5______________________________________Erosion volume loss of arc sprayed coatings done with Pilot wire 1 ofthisinvention at 25° C. and 330° C. for impact angles (α)of 25° and 90°. Temp. = Temp. = Temp. = Temp. = 25° C. 25° C. 330° C. 330° C.Coating α = 90° α = 25° α = 90° α = 25°designation (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)______________________________________P1-01 46.7 18.6 29.8 15.6P1-02 96.1 37.4 42.0 23.3P1-03 57.2 18.2 29.3 18.3P1-04 64.8 33.9 39.9 21.9P1-05 24.7 10.3 18.5 11.7P1-06 52.2 13.2 26.4 18.3P1-07 23.5 8.2 17.0 7.7P1-08 31.0 10.9 24.9 11.5P1-09 25.0 8.3 14.7 9.6______________________________________
Erosion test results for common metals and alloys are shown in Table 7 and the results of coatings prepared from commercial wires and from a cored wire according to the subject invention (P-3) are shown in Table 8. The results shown in Tables 7 and 8 demonstrate that cored wires according to the present invention provide coatings which are vastly superior in erosion resistance than those provided by commercial wires or by common metals and alloys.
TABLE 6______________________________________Erosion volume loss of arc sprayed coatings done with sample wires ofthis invention at 25° C. and 330° C. for impact angles(α) of 25° and 90°. Temp. = Temp. = Temp. = Temp. = 25° C. 25° C. 25° C. 25° C.Cored wire α = 90° α = 25° α = 90° α = 25°sample (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)______________________________________1 80.3 40.3 119.7 71.62 53.3 32.7 89.8 69.83 136.5 46.7 39.0 32.24 66.4 32.3 78.0 54.85 104.8 56.4 48.0 26.26 63.0 39.4 78.9 65.07 52.0 42.0 83.3 79.58 135.5 68.0 96.4 58.49 136.1 72.8 99.2 58.110 83.7 46.3 58.2 40.011 61.7 46.7 82.8 74.512 102.7 50.7 79.0 43.32-12 91.6 35.0 78.5 51.413 129.8 53.7 89.2 60.014 75.9 51.8 103.7 86.615 56.2 38.1 86.6 73.616 49.5 39.5 87.9 77.317 39.8 36.6 78.9 81.018 89.9 20.7 84.2 47.619 124.8 42.9 63.8 29.220 141.4 49.2 65.6 29.621 66.4 38.4 75.8 52.322 76.5 35.2 87.1 63.523 38.0 16.3 18.9 16.224 91.3 31.1 58.3 43.825 77.0 34.1 50.5 28.026 58.9 20.9 24.8 14.827 30.6 8.8 12.3 4.928 72.7 21.8 39.8 22.329 29.2 12.5 11.4 3.930 39.2 13.2 12.5 2.431 65.3 24.2 20.5 14.131 28.6 6.0 9.7 5.132 68.4 13.0 23.7 8.633-1 88.41 40.91 37.73 17.7333-2 30.45 6.14 18.33 11.2933-3 23.56 8.33 18.86 9.7034 42.05 28.18 41.97 26.5235 25.98 14.24 32.88 20.1536 23.11 12.20 20.00 8.9437-1 18.94 11.29 22.35 8.7937-2 26.29 10.98 18.79 11.4439-1 324.55 114.92 106.52 39.7739-2 371.06 171.82 131.06 69.3246 24.62 9.62 6.14 2.80P-2-A 18.86 5.30 16.52 7.27P-2-B 23.18 6.59 15.90 7.58P-2-C 21.52 5.08 15.61 7.12P-3 9.3 7.04 15.8 13.6P-6 19.02 11.02 17.12 13.86GMAW 14.4 6.6 13.4 6.1______________________________________
TABLE 7______________________________________Erosion volume loss of common metals and alloys at 25° C. and330° C.for impact angles (α) of 25° and 90°. Temp. = Temp. = Temp. = Temp. = 25° C. 25° C. 330° C. 330° C. α = 90° α = 25° α = 90° α = 25°Material (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)______________________________________AISI 1045 steel 25.4 56.7 51.1 79.7Stainless steel 30.7 59.0 53.0 95.6316Nickel 200 33.9 53.0 39.5 85.0Copper 34.6 66.3 59.1 140.1Inconel 625 33.4 61.7 63.0 98.3______________________________________
TABLE 8______________________________________Erosion volume loss of arc sprayed coatings done with commercial wiresand P-3 wire at 25° C. and 330° C. for impact angles(α) of 25° and 90°. Temp. = Temp. = Temp. = Temp. = 25° C. 25° C. 330° C. 330° C.Wire α = 90° α = 25° α = 90° α = 25°designation (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)______________________________________P-3 9.3 7.04 15.8 13.6SS 53.94 64.32 67.85 113.9495 MXC 49.09 41.21 71.55 72.35Colmonoy 88 54.47 47.65 122.2 97.12Armacor M 46.97 40.98 73.41 72.95Armacor 16 52.27 59.85 91.44 118.03Duocor 130.68 71.67 164.17 96.9797 T 55.38 58.11 101.59 105.45440 C 46.14 55.23 84.17 102.50Tufton 500 53.26 65.08 91.59 106.29______________________________________
Colmonoy 88 is the Wall Colmonoy Corporation trade-mark of a nickel alloy cored wire. Armacor 16, Armacor M and Duocor are the Amorphous Technologies International trade-marks of iron-based cored wires. 95MXC Ultrahard is the Hobart Tafa Technologies trade-mark of a proprietary high chrome steel alloy cored wire. 97T is the Metallisation Limited trade-mark of a steel-based cored wire containing tungsten carbide. Tufton 500 is the Mogul-Miller Thermal Inc. trade-mark of steel wire. 440C is a martensitic stainless steel. SS-1 is a stainless steel wire of Mogul-Miller Thermal Inc.
Tables 9-15 provide erosion volume losses for embodiments of the invention where particular spraying parameters are varied namely, transverse spray speed (Table 9), arc voltage (Table 10), arc amperage (Tables 11, 12), spraying distance (Table 13) and wire load (Tables 14 and 15).
TABLE 9__________________________________________________________________________Influence of transverse spray speed on erosion volume loss of arc-sprayed coatings manufactured with P-3 cored wireTransverse Temp. = 25° C. Temp. = 25° C. Temp. = 330° C. Temp. = 330° C.spray speed α = 90° α = 25° α = 90° α = 25°(cm/s) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)__________________________________________________________________________ 2 6.6 5.4 15.0 10.5 5 15.4 8.3 20.5 9.610 14.8 7.1 18.1 9.815 17.8 8.6 19.9 11.0__________________________________________________________________________
TABLE 10__________________________________________________________________________Influence of arc voltage on erosion volume loss of arc-sprayed coatingsmanufactured with P-5 cored wire. Arc amperage: 200 A, spray traversespeed:15 cm/s, spray distance: 7.52 cm, air atomizing pressure: 80 psi. Temp. = 25° C. Temp. = 25° C. Temp. = 330° C. Temp. = 330° C.Arc Voltage α = 90° α = 25° α = 90° α = 25°(V) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)__________________________________________________________________________29 26.67 11.74 30.91 15.4631 18.71 9.47 18.49 10.8333 20.23 8.79 18.94 17.7335 14.09 7.27 18.86 10.6837 19.32 7.95 22.27 11.97__________________________________________________________________________
TABLE 11__________________________________________________________________________Influence of arc amperage on erosion volume loss of arc-sprayedcoatings manufactured with P-5 cored wire. Arc voltage: 31V, spraytransversespeed: 15 cm/s, spray distance: 7.52 cm, air atomizing pressure: 80 psi. Temp. = 25° C. Temp. = 25° C. Temp. = 330° C. Temp. = 330° C.Arc amperage α = 90° α = 25° α = 90° α = 25°(A) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)__________________________________________________________________________100 53.40 13.6 36.7 20.6150 20.91 8.9 19.9 15.3200 25.15 9.7 24.4 15.9250 13.64 6.7 19.8 12.5300 13.49 7.8 22.9 15.3__________________________________________________________________________
TABLE 12__________________________________________________________________________Influence of arc amperage on erosion volume loss of arc-sprayedcoatings manufactured with P-5 cored wire. Arc voltage: 35V, spraytransverse.speed: 15 cm/s, spray distance: 7.52 cm, air atomizing pressure: 80 psi. Temp. = 25° C. Temp. = 25° C. Temp. = 330° C. Temp. = 330° C.Arc amperage α = 90° α = 25° α = 90° α = 25°(A) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)__________________________________________________________________________100 31.59 17.50 33.41 21.14150 27.88 12.58 30.76 19.17200 14.09 7.05 23.64 13.49250 9.62 6.21 24.55 10.30300 7.20 5.38 21.29 15.53__________________________________________________________________________
TABLE 13__________________________________________________________________________Influence of spray distance on erosion volume loss of arc-sprayedcoatings manufactured with P-5 cored wire. Arc voltage: 31V, arc amperage200A, spray transverse speed: 15 cm/s, air atomizing pressure: 80 psi.SprayTemp. = 25° C. Temp. = 25° C. Temp. = 330° C. Temp. = 330° C.distanceα = 90° α = 25° α = 90° α = 25°(cm) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)__________________________________________________________________________ 7.6220.83 10.30 23.20 12.8010.1624.55 11.20 22.40 16.5012.7023.03 12.50 26.60 14.1015.2430.23 12.20 17.80 15.1017.7830.38 14.40 21.00 17.7020.3231.44 14.70 25.70 20.90__________________________________________________________________________
TABLE 14__________________________________________________________________________Influence of wire load on erosion volume loss of arc-sprayed coatingsmanufactured with 40 to 45 cored wires. Arc voltage: 31V, arc amperage200 A,spray transverse speed: 15 cm/s, air atomizing pressure: 80 psi. Temp. = 25° C. Temp. = 25° C. Temp. = 330° C. Temp. = 330° C.CoredCore Load α = 90° α = 25° α = 90° α = 25°Wire No(wt %) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)__________________________________________________________________________45 25.6 39.01 33.86 73.11 58.8644 29.2 41.36 23.64 62.20 42.8843 34.8 22.65 14.77 35.00 22.8042 38.7 18.56 8.86 21.29 11.5241 41.6 23.26 12.58 33.48 11.5240 46.5 20.23 7.95 15.68 6.67__________________________________________________________________________
TABLE 15__________________________________________________________________________Influence of wire load on erosion volume loss of arc-sprayed coatingsmanufactured with 40 to 45 cored wires. Arc voltage: 35V, arc amperage200 A,spray transverse speed: 15 cm/s, air atomizing pressure: 80 psi. Temp. = 25° C. Temp. = 25° C. Temp. = 330° C. Temp. = 330° C.CoredCore Load α = 90° α = 25° α = 90° α = 25°Wire No(wt %) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)__________________________________________________________________________45 25.6 39.01 33.86 73.11 58.8644 29.2 41.36 23.64 62.20 42.8843 34.8 22.65 14.77 35.00 22.8042 38.7 18.56 8.86 21.29 11.5241 41.6 23.26 12.58 33.48 11.5240 46.5 20.23 7.95 15.68 6.67__________________________________________________________________________
Example with Gas Metal Arc Welding (GMAW)
P-3 cored wire was deposited by using the Gas Metal Arc Welding (GMAW) process with a Hobart Mega-Flex* 650 RVS apparatus. Argon with 2% oxygen flowing at 25 cubic feet per minute was used for depositing P-3 cored wire feed at a rate of 250 inches per minute. Arc voltage of 30 V and amperage of 200 A were used in this example. The erosion volume loss is shown in Table 16.
TABLE 16__________________________________________________________________________Erosion volume loss for coating prepared using cored wire P-3 usingGas Metal Arc Welding (GMAW)CoredTemp. = 25° C. Temp. = 25° C. Temp. = 330° C. Temp. = 330° C.wire α = 90° α = 25° α = 90° α = 25°sample(mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg) (mm.sup.3 /kg)__________________________________________________________________________P-3 14.4 6.6 13.4 6.1__________________________________________________________________________
With reference to compositions of the wires recited in Table 2, the spraying parameters in Tables 3 and 4, the erosion results reported in Tables 4, 5, and 6 and results reported in Tables 7-15, the following conclusions were determined:
a) Arc sprayed coatings containing only steel and boron powders (samples 2, 4, 7, 15 and 16) did not present erosion resistance better than 1045 steel at 25° C. and 330° C. for both particle impact angle of 25° and 90°. The maximum percentage of boron that could be reached was 12 wt. % in example 4. The global composition of this coating (5.33 wt. % boron) corresponds to a composition higher than that of the eutectic melt in the fe-B system. This composition is higher in boron than that described by Moen. Addition of chromium within the core (sample 17) did not improve the erosion resistance at 330° C. All these coatings contain fine crystals dispersed in metals. The nature, size and distribution of these microstructural features do not provide enhanced resistance to particle impact events.
b) Arc sprayed coatings done with wires having in their core steel and ferroboron presented improved erosion properties (for at least one erosion condition) in comparison with those containing only steel and boron powders. Higher is the erosion resistance lower is their steel content within the core, higher should be their ferroboron content and larger should be the particle size of ferroboron. (Samples: 5, 6, 9, 10-12, 14, 21-22, 24, 25, 28).
c) Arc sprayed coatings done with cored wires having in their cores steel, ferroboron and boron (Samples 1, 8, 13) did not present improved properties over conventional steel. As in a) boron forms low melting point materials having microstructural features not compatible with the particle impact events.
d) Arc sprayed coatings done with cored wires containing within their cores only ferroboron (Samples 3, 18, 19, 23, 26, 27, 29-31, 33, 35-37, 40-46, P-1, P-2, P-3, P-5, P-6) present improved erosion properties over conventional steel at the temperature of 330° C. and also at room temperature. As shown, the erosion resistance of coatings is related to the size of ferroboron particles within the core. Large particles of ferroboron favour the development of microstructural features that can efficiently deflect the erodent particles. Table 8 provides a comparison of the erosion resistance of example P-3 with that of arc sprayed coatings done with commercial wires.
e) Arc sprayed coatings done with cored wires having wire sheaths made of metals having high affinity for oxygen such as A-1 kanthal alloy, a ferrous alloy containing aluminum (Example 39), are merely not erosion-resistant.
The test results confirm that powders comprised of larger ferroboron particles provide better erosion resistance than powders comprised of smaller particles. Preferred embodiments of the invention will include ferroboron powders in which the majority of particles are greater than about 45 μm in size. One preferred core powder includes a mixture of ferroboron particles wherein 30-40 wt. % are particles having sizes larger than 150 μm, 30-40 wt. % are particles having sizes between 150 and 75 μm, 10-15 wt. % are particles having sizes between 75 and 45 μm and about 15 wt. % are particles having sizes less than 45 μm.
The results also demonstrate that a ductile, low carbon steel, such as 1005 steel, is the preferred material for use in preparation of the metal sheath. In preferred embodiments, the ferroboron powder core will comprise between 20 and 48 wt. % and the ductile metal sheath will comprise between 80 and 52 wt. % of the cored wire.
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A method of on site application of an erosion resistant coating. When deposited on the surface of a metallic substrate, the coating comprises hard ferroboride phases bound with a ductile metallic phase. The ductile metallic phase is selected from metals which have a low affinity for oxygen. The preparation and composition of a cored wire adapted for use in application of the erosion resistant coatings are also disclosed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to selected poly(oxyalkylated) pyrazoles and their use as corrosion inhibitors.
2. Description of the Prior Art
The prior art has disclosed a wide variety of chemical compounds which effectively reduce the corrosive properties of liquids such as antifreezes, acid treating baths and hydraulic fluids. These inhibitors are generally added to the corrosive liquids to protect the metals in contact with these liquids. Alternatively, such inhibitors may be applied first to the metal surface, either as is, or as a solution in some carrier liquid or paste.
While many of these known inhibitors have been used successfully for many years, stricter toxicological and other environmental standards are restricting the use of some of the compounds (e.g., chromates and dichromates). Accordingly, there is a need in the art to develop new and effective corrosion inhibitors which do not pose these environmental problems.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to, as compositions of matter, selected poly(oxyalkylated) pyrazoles of the formula (I): ##STR2## wherein R and R' are independently selected from lower alkyl groups having 1 to 4 carbon atoms; each R" is individually selected from hydrogen and methyl; and n is from 2 to about 20. The present invention is also directed toward the use of these compounds as corrosion inhibitors.
DETAILED DESCRIPTION
The poly(oxyalkylated) pyrazole compounds of the present invention may be prepared by reacting the corresponding 3,5-di(lower alkyl) pyrazole with two or more moles of either ethylene oxide or propylene oxide to produce the desired poly(oxyalkylated) pyrazole. This general reaction is illustrated by the following Equation (A) wherein 3,5-dimethylpyrazole is reacted with 10 moles of ethylene oxide to produce the desired 3,5-dimethylpyrazole.10 ethylene oxide adduct product: ##STR3##
The 3,5-di(lower alkyl) pyrazole reactants are commonly made by reacting hydrazine with a 1,3-diketone such as acetylacetone. The general synthesis of these compounds may be found in an article entitled "Synthesis of Pyrazoles" by T. L. Jacobs, which is in Heterocyclic Compounds, Vol. 5, Chapter 2, Editor--R. C. Elderfield, John Wiley & Sons, Inc., New York, 1957. A preferred compound of this class is 3,5-dimethylpyrazole. Note that the 3- and 5-position substituents on the pyrazole ring do not necessarily have to be the same lower alkyl group.
It should also be noted that the number of EO or PO units per ring unit is not the same for ever ring, but rather is statistically distributed. Thus, n in Formula (I) represents the average number of EO or PO units per ring and that the actual number on any given ring may be less or greater than n. That is, when n=10, it is meant that ten moles of EO or PO have been reacted per mole of the pyrazole. Preferably, it is desired to employ from about 5 to about 20 moles of EO or PO per one mole of the pyrazole. More preferably, it is desired to use from about 5 to about 10 moles per mole of the pyrazole.
The ethylene oxide (EO) and propylene oxide (PO) reactants are commercially available chemicals which may be obtained from many sources. Mixtures of EO and PO may also be employed as reactants, either added sequentially or mixed together.
Any conventional reaction conditions designed to produce these poly(oxyalkylated) pyrazoles may be employed in the synthesis of the present compounds and the present invention is not intended to be limited to any particular reaction conditions. Advantageously and preferably, the present compounds may be made according to the reaction illustrated by Equation (A) in the presence of an inert solvent such as toluene and an alkaline catalyst like powdered potassium hydroxide. However, the use of a solvent and a catalyst is only desirable, and not necessary. The reaction temperature and time will both depend upon many factors including the specific reactants and apparatus employed. In most situations, reaction temperatures from about 50° C. to about 200° C., preferably from about 100° C. to about 150° C., may be employed. Reaction times from about 30 minutes to about 600 minutes may be employed. The reaction may preferably be carried out under pressure from about 10 to about 100 psig or more, if desired. The desired adduct product may be recovered from the reaction mixture by any conventional means, for example, evaporation of the solvent, filtration, extraction, recrystallization or the like.
It should be noted that while the reaction illustrated by Equation (A) is the preferred method for preparing the compounds of the present invention, other synthetic methods may also be employed.
Also, in accordance with the present invention, it has been found that the compounds of Formula (I), above, may be utilized as effective corrosion inhibitors. In practicing the process of the present invention, metal surfaces are contacted with an effective corrosion-inhibiting amount of one or more of these compounds. "Metal surfaces" which may be protected by the corrosion-inhibition properties of the compounds of the present invention include ferrous and non-ferrous metals such as cast iron, steel, brass, copper, solder, aluminium and other materials commonly used with corrosive liquids. It is understood that the term "effecive corrosion-inhibiting amount" as used in the specification and claims herein is intended to include any amount that will prevent or control the corrosion on said metal surfaces. Of course, this amount may be constantly changing because of the possible variations in many parameters. Some of these parameters may include the specific corrosive material present; the specific compound used; the specific metal to be protected against corrosion; the salt and oxygen content in the system; the geometry and capacity of the system to be protected against corrosion; flow velocity of the corrosive material; temperature and the like.
One preferred use for the corrosion inhibitors of the present invention is in antifreeze compositions comprising a water-soluble liquid alcohol freezing point depressant. For example, an antifreeze composition containing an effective corrosion-inhibiting amount of one or more of the compounds of Formula (I) may be used in heat exchange systems such as the general antifreeze system for automotive engines. The antifreeze compositions of this invention may contain, besides the freezing point depressant and the corrosion inhibitor, other conventional additives such as dyes, antifoam agents and the like.
The freezing point depressants of the present invention include any of the water miscible liquid alcohols such as monohydroxy lower alkyl alcohols and the liquid polyhydroxy alcohols such as the alkylene and dialkylene glycols. Specific examples of the alcohol contemplated herein are methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, and mixtures thereof. A preferred glycol is ethylene glycol, which as sold commercially often contains a small amount, up to 10% by weight, of diethylene glycol. The term ethylene glycol as used herein is intended to include either the pure or commerical compound. This is also true of the other freezing point depressant alcohols contemplated herein. Generally, the freezing point depressant (or depressants) is mixed with water to make aqueous solutions containing from about 10% to about 90% by weight of the depressant.
While the effective amount of corrosion inhibitors in antifreeze solutions may vary on account of the many factors listed above, the general effective range is from about 0.001% to about 5% by weight of the total amount of freezing point depressant in the aqueous solution which is in contact with metal.
Another preferred use of the corrosion inhibitors of the present invention is in aqueous acidic solutions or baths which are in contact with metal surfaces. Such acidic solutions include mineral acid solutions made up of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and mixtures thereof. These acidic solutions may be used for acid-pickling baths for the surface cleaning of metals or in similar products. The preferred amount of this corrosion inhibitor in such acid solutions is preferably at least 0.005% by weight of the solution; more preferably, from about 0.01% to about 1% by weight of the bath.
Still another preferred use of the instant corrosion-inhibiting compounds is in hydraulic fluids such as hydraulic brake systems, hydraulic steering mechanisms, hydraulic transmission and the like. Generally, the hydraulic fluids which are already known in the art are usually comprised of a lubricant or base fluid, a diluent portion, and an inhibitor portion. The lubricant or base fluid and the diluent are usually comprised of a wide variety of alcohols, alcohol ethers or a mixture of both. The inhibitor portion normally contains antioxidants and buffers besides corrosion inhibitors. An exemplary list of base fluids, diluents and various additives such as antioxidants, alkaline buffers, rubber swell adjusters and the like are shown in U.S. Pat. No. 3,629,111, which issued to Cramer on Dec. 21, 1971, and in "Introduction to Hydraulic Fluids" by Roger E. Hatton, Reinhold Publishing Corporation, 1962. Both of these are incorporated herein by reference in their entireties.
It is believed that the present inhibitor compounds are especially useful in hydraulic fluids which employ polyoxyethylene glycol as the base fluid. Generally, the effective amount of these inhibitors in most hydraulic fluids may range from about 0.1% by weight to about 5.0% by weight of the total fluid; more preferably, from about 0.5 to about 3.0% by weight of the total fluid.
The compounds of this invention may be used for other corrosion protection applications besides these three preferred applications. In addition, it may be desirable that these corrosion inhibitors be applied with other known corrosion inhibitors.
The following examples further illustrate the present invention. All parts and percentages employed herein are by weight unless otherwise indicated.
EXAMPLE 1
3,5-Dimethylpyrazole [28.8 grams (0.3 moles)], toluene (170 milliliters), and a catalytic quantity of powdered potassium hydroxide (about 0.1 gram) were added to a 500 ml, 3-neck flask provided with a thermometer, magnetic stirrer, dry ice/acetone reflux condenser and a pressure-equalized ethylene oxide addition funnel that was cooled with a dry ice jacket. Provision was made to purge the apparatus with N 2 and to keep an N 2 blanket on during the run. The reactor was heated to reflux (about 110° C.) and ethylene oxide [32.5 grams (0.74 moles)] was slowly added dropwise over a period of 6 hours. This corresponds to a mole ratio of EO to pyrazole of 2.5. The resulting reddish-orange solution was stripped of toluene and unreacted ethylene oxide on a rotary evaporator, yielding a residue of about 50.5 grams. Gas chromatography of this product shows 4 peaks in the area ratio of 59:34:6:1 and believed to correspond respectively to the 1,2,3, and 4 mole ethylene oxide adducts of 3,5-dimethylpyrazole.
EXAMPLE 2
3,5-Dimethylpyrazole [120 grams (1.25 moles)], toluene (300 milliliters), and powdered potassium hydroxide (6 grams) were added to a stainless steel pressure vessel which was then flushed with N 2 . Ethylene oxide [210 grams (4.75 moles)] was then pressured with N 2 into the reaction vessel at a pressure up to 50 psig and a temperature of 130°-140° C. This corresponds to a mole ratio of EO to pyrazole of 3.8. Addition time was 47 minutes with a post addition time of 85 minutes; the temperature was kept in the desired range by periodic cooling by means of a water-cooled coil in the reactor. Toluene and unreacted ethylene oxide were then removed by stripping on a rotary evaporator using a vacuum pump and heating to 74° C. The residue weighed 307 grams, a recovery of 91.3% based on the weight of ethylene oxide and 3,5-dimethylpyrazole added. The elemental analysis of this product was:
______________________________________ C H N______________________________________Found, % by weight 57.07 8.16 10.91Theory for DMP . 3.8 EO, % 57.45 8.43 10.64______________________________________
EXAMPLE 3
Example 2 was repeated, except that a higher ratio of ethylene oxide to 3,5-dimethylpyrazole was used to give a longer polyether chain on the pyrazole ring. 3,5-Dimethylpyrazole [96 grams (1 mole)], toluene (305 grams) and powdered potassium hydroxide (4.8 grams) were charged to the reactor and ethylene oxide [220 grams (5 moles)] was then pressured in, corresponding to an EO to pyrazole mole ratio of 5. After vacuum stripping of toluene and unreacted ethylene oxide, if any, 317 grams of a clear, reddish-orange product remained, representing 98.9% of the starting reactants and catalyst. The elemental analysis of this product was:
______________________________________ C H N______________________________________Found, % by weight 56.63 8.71 8.69Theory for DMP . 5 EO, % 56.96 8.86 8.86______________________________________
EXAMPLE 4
Example 3 was repeated, except with an ethylene oxide to 3,5-dimethylpyrazole molar ratio of 10:1. Analysis of the resulting product was:
______________________________________ C H N______________________________________Found, % by weight 55.67 8.82 4.98Theory for DMP . 10 EO, % 55.97 8.96 5.22______________________________________
EXAMPLE 5
The apparatus and procedure of Example 1 was used to react propylene oxide with 3,5-dimethylpyrazole in a ratio of 2:1, respectively. Analysis of the resulting product was:
______________________________________ C H N______________________________________Found, % by weight 60.40 8.99 16.48Theory for DMP . 2 PO, % 62.33 9.16 17.43______________________________________
Gas chromatographic analysis of this product shows two peaks, presumed to be 85% DMP.1 PO and 15% DMP.2 PO.
EXAMPLE 6
The apparatus and procedure of Example 2 was repeated, except using a molar ratio of propylene oxide to 3,5-dimethylpyrazole of 5:1. The analysis of the resulting product was:
______________________________________ C H N______________________________________Found, % by weight 60.73 10.01 7.30Theory for DMP . 5 PO, % 60.96 10.16 7.49______________________________________
EXAMPLE 7
The apparatus and procedure of Example 2 was repeated, except using a molar ratio of propylene oxide to 3,5-dimethylpyrazole of 10:1. 403 Grams of final product were recovered, representing about 97% of the reactants fed.
EXAMPLE 8
The compounds prepared according to the methods of Examples 4, 6 and 7, above, were tested as corrosion inhibitors in glycol antifreezes according to test method ANSI/ASTM D 1384-70 (Reapproved 1975), "Corrosion Test For Engine Coolants In Glassware". These tests showed that these ethylene oxide and propylene oxide adducts of 3,5-dimethylpyrazole had excellent corrosion-inhibiting properties. The results of these tests are given in Table I, below.
In carrying out this test method D-1384, several antifreeze solutions (each 750 ml) were formed which contained ethylene glycol (250 ml), corrosive water (500 ml), a potassium phosphate buffer [K 2 HPO 4 , (7.5-8 g)] and one of the compounds of Examples 4, 6 and 7 [about 192 grams of each with none for the blank test]. These solutions were placed in 1000 ml beakers. A bundle of six different metal coupons (each coupon having already been weighed) was placed in the beaker and covered by the solution. These beakers were kept at 190° F. for 336 hours, during which time the solutions were aerated. At the end of this time period, the bundles of coupons were removed from the beaker, disassembled, cleaned, reweighed, and the weight change was detemined. The weight change per square centimeter of each coupon was determined and is shown in Table I. As can be seen, the weight change with these inhibitors present was much less than the blank test, indicating the excellent protection provided by these compounds.
TABLE I______________________________________Weight Change (in mg/cm.sup.2)Metal Blank DMP . 10 EO DMP . 5 PO DMP . 10 PO______________________________________Copper 32.7 0.46 2.36 1.49Solder 33.9 0.22 0.38 0.36Brass 33.2 0.26 0.23 0.45Steel 51.8 0.07 0.05 0.05Cast Iron 42.5 +0.08 +0.07 0.03Alu- 3.2 +0.05 0.01 0.01minum______________________________________
EXAMPLE 9
The compounds of Examples 2-7 were further tested as corrosion inhibitors in aqueous acidic solutions according to the linear polarization method described in ASTM test method G5-72. The results of this test are given below in Table II.
By this method, the effectiveness of these compounds as corrosion inhibitors was rated by, first, determining the linear polarization of a mild steel sammple in an uninhibited 1.0 N H 2 SO 4 solution, and second, in the same 1.0 N H 2 SO 4 solution after one of the compounds of Examples 2-7 was added (the amount of each compound added was equivalent to 0.25% by weight of the solution). From these linear polarization measurements, the % protection afforded by each inhibitor in this acid solution was determined by the following formula: ##EQU1## wherein LP u is the linear polarization of the uninhibited sample and LP i is the linear polarization of the sample placed in the acid solution containing the inhibitor compound.
As can been seen from Table II, the various ethylene oxide (EO) and propylene oxide (PO) adducts of 3,5-dimethylpyrazole (DMP) are much better than 3,5-dimethylpyrazole by itself.
TABLE II______________________________________ % ProtectionExample Compound in 1.0 NH.sub.2 SO.sub.4______________________________________2 DMP . 4 EO 28.93 DMP . 5 EO 88.64 DMP . 10 EO 90.15 DMP . 2 PO 37.06 DMP . 5 PO 95.07 DMP . 10 PO 97.2Comparison 1 DMP 8.7______________________________________
EXAMPLE 10
The compound (DMP.10 PO) prepared in Example 7, above, was tested as a corrosion inhibitor in a poly-glycol-based hydraulic fluid according to the test method set forth in SAE-J1703f. This poly-glycol-based fluid with the inhibitor included had the following formula:
75.8% Triethyleneglycol monomethylether 1
20.0% Polypropyleneglycol (molecular weight 1000) 2
3.0% Polyethylene Glycol (molecular weight 300) 3
0.2% Bis Phenol-A 4
0.2% Borax 5
0.2% Boric Acid 6
0.2% Trimethylolpropane 7
0.4% DMP.10 PO
After this hydraulic fluid formulation is made, a bundle of six different metal coupons (previously weighed) were placed in a test jar containing the fluid. All of the coupons were fully covered by the solution. After running the test at 100° C. for 5 days, the coupons were removed, washed, dried, and weighed. The weight change per square centimeter of each coupon was then determined. The results of this corrosion test in the hydraulic fluid containing the DMP.10 PO inhibitor vs. the same uninhibited hydraulic fluid are given in Table III. As can be seen, the hydraulic fluid containing the inhibitor had a smaller weight change for some metals and, thus, offered protection against corrosion.
TABLE III______________________________________ Weight Change of Coupons (in mg/cm.sup.2) For UnihibitedMetal Coupon Fluid For Fluid with DMP . 10 PO______________________________________Copper 0.67 0.40Brass 0.69 0.45Cast Iron +0.11 +0.21Aluminum +0.01 0.005Steel +0.35 0.02Tin +0.01 0.03______________________________________
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Disclosed are selected poly(oxyalkylated) pyrazoles of the formula: ##STR1## wherein R and R' are independently selected from lower alkyl groups having 1 to 4 carbon atoms; each R" is individually selected from hydrogen and methyl; and n is from 2 to about 20. These compounds are shown to be effective corrosion inhibitors in corrosive liquids such as acids, antifreezes and hydraulic fluids.
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BACKGROUND OF THE INVENTION
The present invention relates to a new and improved method of, and a drafting, arrangement for, spinning machines, particularly for draw frames, for processing a fiber sliver with a staple range encompassing short to long staple fibers.
The drafting arrangement comprises a pre-draft zone and a main draft zone, as well as bottom rolls arranged on a machine frame and pressure rolls arranged thereabove and forming drafting zones.
In German Pat. No. 1,250,315 a drafting arrangement is shown and described, which, as seen in the direction of movement of the fiber sliver, contains an input pair of rolls, an intermediate pair of rolls, and a pair of delivery rolls. Each roll pair consists of a bottom roll and a corresponding or related pressure cell.
The pair of input rolls and the pair of intermediate rolls collectively form a pre-draft zone, whereas the pair of intermediate rolls and the pair of delivery rolls form a main draft zone.
The pair of input rolls is linearly shiftable forwards and backwards, as seen in the direction of movement of the fiber sliver, for the purpose of adapting the length of the pre-draft zone. Both rolls are independently shiftable.
The intermediate and the delivery bottom rolls are fixedly arranged, whereas the intermediate and the delivery pressure rolls are linearly shiftable in the same manner as the input pressure roll.
All three pressure rolls are vertically movable with respect to a base plate taking-up the bearing blocks of the bottom rolls, in such a manner that during the aforementioned linear shifting of the pressure rolls, the latter can effect, in combination with the vertical movability, a movement about the fixed or fixedly arranged bottom rolls. Thus, the possibility is given to adapt the length of the main drafting zone and to adapt it to the staple length to a certain extent.
The diameter of the delivery bottom roll is larger than the diameter of all of the other rolls. The bearing blocks of the pressure rolls are arranged to be linearly shiftable on the bearing blocks of the bottom rolls. The pressure applied to the pressure rolls is exerted by using spring-loaded pressure pistons which are mounted upon a pivotable and arrestable support member.
Furthermore, in Swiss Pat. No. 426,570 there is disclosed a drafting arrangement containing a pre-draft zone and a main draft zone, in which the pressure rolls are arranged to be pivotable about the axis of the bottom rolls for enlarging or shortening the wrapping arc of the fiber sliver upon the bottom rolls.
For adapting the nip line distances, limiting the pre-draft zone and the main draft zone, to the staple length of the fiber material to be processed, the mutual distances of the groups of rolls are changeable.
Production increases in a drafting arrangement necessarily imply an increase in sliver speed. High sliver speeds, for instance, of 800 m/min. or more, of the drafted sliver, i.e. at the delivery side of the drafting arrangement, require high rotational speeds of the drafting arrangement rolls which, in turn, imposes more stringent requirements upon the bearings of the rolls.
The useful service life of a bearing is determined, apart from the factors of rotational speed and bearing load, by the accuracy of the settings or mounting, for instance with respect to the parallelity of the pressure rolls and the related bottom rolls, and with respect to the accurate alignment of the roll axes with respect to the elements driving the shafts.
If the drafting arrangement disclosed in German Pat. No. 1,250,315 is considered under the abovementioned aspects, it will be recognised that for the shiftability and the arrestability, respectively, of the bearing blocks for the pair of input rolls, and the bearing blocks for the intermediate and the delivery pressure rolls, there are not provided any special devices or facilities for accurately arresting or fixation thereof. Hence, these bearing positions are only adjustable or settable in a relatively inaccurate manner, or only by using special setting or adjustment devices, which have been neither shown nor described. The use of such auxiliary devices, however, is time-consuming, cumbersome, and thus, unsatisfactory.
Furthermore, the mutual linear shiftability of the pressure rolls with respect to the bottom rolls, for the purpose of adapting the nip line distances of the drafting zones, exhibits the disadvantage that, due to the linear shifting of the pressure rolls the spring or resilient forces of the pressure pistons act with varying force upon the fiber sliver, depending upon the position of the pressure rolls at the bottom rolls, which influences the force components in angular direction.
A further disadvantage resides in the large diameter of the delivery bottom roll, which causes an increased nip line distance in the main drafting zone.
Furthermore, the drafting system exhibits the disadvantage that, for instance, for guiding the fiber sliver into a sliver can, there is required an additional deflection of the sliver after the drafting arrangement. At sliver speeds of 13.3 m/sec. and more such imposes an additional, undesirable stress upon the sliver, caused by centrifugal forces, and thus, constitutes a disadvantage of the method.
SUMMARY OF THE INVENTION
It thus is an important object of the present invention to eliminate these disadvantages.
A further significant object of the present invention is directed to a new and improved method and drafting arrangement for spinning machines for processing a fiber sliver in a manner not afflicted with the aforementioned drawbacks and shortcomings of the prior art proposals.
Still a further important object of the present invention is directed to a new and improved drafting arrangement for spinning machines for processing a fiber sliver in a highly reliable and protective manner, allowing for improved sliver processing, while affording an apparatus construction which is relatively simple in design, economical to manufacture, extremely reliable in operation, not readily subject to breakdown or malfunction, and requires a minimum of maintenance and servicing.
Yet a further important object of the present invention aims at providing a new and improved method of, and drafting arrangement for, spinning machines for processing a fiber sliver wherein there can be reliably and effectively processed a wide range of staple lengths of the fibers.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the method aspects of the present development are manifested by the features that, that with increasing speed of the fiber sliver, owing to the thinning of the fiber sliver during the drafting process, the direction of movement is deflected positively per drafting step in front of and/or within the drafting zone in such a manner that, the delivered fiber sliver is subjected, with respect to the inputted sliver, gradually to a total positive deflection of substantially a 90° angle, and that per positive deflection the angular acceleration (r.w. 2 ) does not exceed a value of 400/sec. 2 .
Concerning the drafting arrangement of the present development, such is manifested by the features that, all bottom rolls are fixedly arranged on the machine frame. The first pressure roll, as seen in the direction of movement of the fiber sliver, limiting the pre-draft zone, as well as the first pressure roll, limiting the main drafting zone, are displaceably arranged and arrestably along a respective arc about the rotational axis of the corresponding or related bottom roll. The first bottom rolls limiting the drafting zones are of a diameter which corresponds at least to the longest fiber length to be processed.
The advantages achieved when practising the present invention reside substantially in that:
(a) Owing to the deflection of the fiber sliver in the drafting process, notwithstanding high sliver speeds at the delivery or output side of the drafting arrangement, the values of angular acceleration at the deflections or deflection locations in the drafting arrangement are maintained within acceptable limits.
(b) Owing to the deflection in the drafting process the fiber sliver, entering substantially horizontally, upon leaving the drafting arrangement, can be delivered without any additional deflection and over a short distance into the trumpet or funnel or into the subsequently arranged pair of calender rolls delivering a measuring value, so that an optimally short length of defective sliver can be transferred between the last pair of drafting rolls and the calender rolls.
(c) Owing to the fixed arrangement of the bottom rolls accurate alignment of the bearings is ensured after assembly, which positively contributes to the useful service life of the bearings and a reduction in the time required for accommodation of settings to other fiber staple lengths.
(d) Owing to the shiftability of the pressure rolls about the mentioned arc, there is possible an accommodation of the drafting arrangement to the staple length of the fiber sliver to be processed without changing the position of the bottom rolls.
(e) As the direction of the force exerted by the pressure rolls relative to the axis of the corresponding bottom roll remains the same, the effect of the force upon the fiber sliver remains constant.
An advantageous embodiment of the drafting arrangement is constituted by an arrangement of the pressure rolls upon a pivotable arm. By using this construction also broad fiber slivers can be easily and reliably inserted into the drafting arrangement.
A further advantageous embodiment resides in the features that, the shiftable or displaceable pressure rolls are adjustable and arrestable, by using an arresting device, for adaption to the encountered staple length, and the amount of shifting is measurable using a scale in such a manner that, notwithstanding the shiftability of the pressure rolls, there is ensured for accurate parallel guiding of the pressure rolls.
Furthermore, the shiftability or displaceability of the second pressure roll, limiting the main drafting zone, along an arc about the related bottom cylinder renders it possible to ensure for a tangential intake or infeed of the fiber into this pair of rolls, independently of whether there is used a pressure rod or bar causes a positive or a negative deflection of the fiber sliver.
Owing to the small diameter of the second bottom roll limiting the main draft zone the advantage results that, in spite of the also advantageous large diameter of the preceding bottom roll an optimally short nip distance is obtainable.
BRIEF DISCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a side view of the invention drafting arrangement in its operating position and shown semi-schematically;
FIG. 2 is a front view of the drafting arrangement according to FIG. 1 in its operating position and shown semi-schematically;
FIG. 3 illustrates a detail of the drafting arrangement according to FIG. 1 as seen from the same side and shown semi-schematically;
FIG. 4 illustrates a detail of FIG. 3, partially shown in sectional view along the line A--A and shown semi-schematically; and
FIGS. 5 and 6 respectively show alternative embodiments of the drafting arrangement according to FIG. 1, each depicted as an enlarged partial view of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, the exemplary construction of drafting arrangement 1 comprises a machine frame 2, at which there are pivotably supported, by using a hinge or link pin 3, the arm parts or elements 4 forming a double arm.
The arm parts or elements 4 each comprise an arc or curved member 5 and an arc or curved member 6 as well as an end member 7. Provided on the end or terminal member 7 is a notch 8 for receiving a respective fixing pin or bolt 9. The fixing or arresting pin 9 is part of a pneumatic cylinder unit 10. The fixing pin or bolt 9 is designed to seatingly fit into the notch 8 and is used for fixing the double arm in the working position shown with solid lines in FIGS. 1 and 2. The lifted-off position of the double arm is indicated in FIG. 1 with dash-dotted or phantom lines.
The bottom rolls 11, 12, 13 and 14 are rotatably supported at the machine frame 2 by using the shafts or axles 15, 16, 17 and 18, respectively. The bottom rolls 11, 12, 13 and 14 are individually driven by using any suitable and therefore not particularly illustrated drive means.
The arc or curved parts 5 each comprising an arc-shaped guide slot or track 19 which is coaxially arranged with respect to the shaft or axle 15, and the arc or curved parts 6 each comprise an arc-shaped guide slot or track 20 which is coaxially arranged with respect to the shaft or axle 17. The guide slots or tracks 19 are used for guiding a pair of bearing blocks 21 (one part of the pair only being shown in FIG. 2), whereas the guide slots or tracks 20 are used for guiding a pair of bearing blocks 23. In the terminal or end portion 7 a guide slot 60 is arranged coaxially with respect to the shaft or axle 18 and is used for guiding a pair of bearing blocks 25.
A pair of bearing blocks 22 is fixedly arranged on the double arm 4 at the entrance or inlet side of the drafting arrangement, and a pair of bearing blocks 24 is arranged at the transition zone between the arc or curved part 5 and the arc or curved part 6.
Viewed in the direction of travel of the fiber sliver 26 (schematically indicated by an arrow in FIG. 1), the drafting arrangement 1 comprises, in the following sequence, a pressure roll 27 rotatably supported in the pair of bearing blocks 22, a first pressure roll 28 limiting the beginning of the pre-drafting zone and rotatably supported in the pair of bearing blocks 21, a second pressure roll 29 limiting the end of the pre-drafting zone and rotatably supported in the pair of bearing blocks 24, a first pressure roll 30 limiting the beginning of the main drafting zone and rotatably supported in the pair of bearing blocks 23, as well as a second pressure roll 31 limiting the end of the main drafting zone and rotatably supported in the pair of bearing blocks 25.
The rolls 11 and 28 form, as seen in the direction of movement of the fiber sliver 26, the first fiber sliver nip line, and the rolls 12 and 29 form the second nip line. These nip lines or nips limit the pre-drafting zone.
The rolls 13 and 30 form the first fiber sliver nip line, and the rolls 14 and 31 the second fiber sliver nip line. These nip lines limit the main drafting zone.
The pairs of bearing blocks 22 and 24 are fixedly arranged, whereas the pairs of bearing blocks 21 and 23, respectively, are slideably arranged along the guide slots 19 and 20, respectively, for adaption or accommodation to the staple length of the fiber sliver to be processed, and after adaptation thereto are again fixable or arrestable. Furthermore, the pair of bearing blocks 25 is slideably and again arrestably or fixably arranged in the guide slot 60, in order to ensure for the tangential intake or infeed of the fiber sliver, notwithstanding the variable intake position of the fiber sliver, which can change due to the shifting of the pressure roll 30.
For ensuring for substantial parallelism of the pressure rolls 28 and 30 with respect to the bottom rolls 11 and 13, respectively, in radial direction with respect to the axes or shafts 15 and 17, respectively, there are provided, on the one hand, on the arc or curved parts 5 and 6 the latching or ratcheting teeth 32 (FIGS. 3 and 4) and a scale 33 corresponding to the number of such latching or ratcheting teeth 32, and, on the other hand, on the pairs of bearing blocks 21 and 23 there is provided a respective arresting device 34 which engages with the latching teeth 32. This arresting device 34 is co-ordinated to each individual bearing block of the pairs of bearing blocks 21 and 23. A bearing block of such type comprises a lower block part 35 equipped with a guide opening 36 for taking-up and for guiding a shaft bearing 37 of a pressure roll shaft 38. Each respective pressure roll shaft 38 is used for mounting of the related pressure rolls 27, 28, 29, 30 and 31.
Furthermore, the lower bearing block part 35 is shaped as a cylinder containing a piston 39, a related piston rod 40, a spring 41, a compressed air connection 42, and an exhaust opening or port 43.
A bearing block upper part 44, which is rigidly connected to the bearing block lower part 35, is used as a closing cover of the cylinder arrangement.
In the bearing block upper part 44 there is rigidly threadibly secured a guide pin 45, which is part of the arresting device 34, the guide pin 45 being threaded into the upper part 44 by means of the threaded portion 46. The guide pin 45 guides an arresting member 47. A pressure spring 48, tensioned between the arresting member 47 and a guide pin upper portion 45.1, presses the arresting member 47 against the bearing block upper part 44. The arresting member 47 can be lifted-off from the bearing block upper part 44 against the force of the pressure spring 48.
The latching or ratcheting teeth 32 provided on the arc or curved parts 5 and 6 engage, as the arresting member 47 contacts the bearing block upper part 44, with the teeth 49 provided on the arresting member 47, as best seen by referring to FIG. 4.
Furthermore, two guide pins 50 are pressed into the bearing block upper part 44. These guide pins 50 penetrate into the guide slots 19 or 20, as the case may be, and the diameter of such guide pins is chosen such that there results an accurate sliding guidance of the individual bearing blocks 21, 23, 25 along the related guide slots 19, 20 and 60, respectively.
A fixing bolt or screw 51 or equivalent structure provided with a nut 52 arrests the individual bearing blocks at the arc or curved parts or elements 5 and 6 and at the end part 7, respectively.
If the pairs of bearing blocks 21 and/or 23 are to be shifted, then the related fixing screw 51 (FIGS. 3 and 4) is loosened, the arresting member 47 is raised, while applying a manual force against the action of the force of the spring 48, from the bearing block lower part 44 along the guide pin 45. Now the pair of bearing blocks 21 and/or 23 are slid in contact with and along the related guide slot 19 and 20, respectively, upon the curved part or element 5 and 6 respectively. The amount of shifting can be read at the arresting device scale 33 or equivalent structure.
The pairs of bearing blocks 22, 24 and 25 comprise the same elements as the pairs of bearing blocks 21 and 23 heretofore described, with the exception that the arresting device 34 is dispensed with.
The pairs of bearing blocks 22 and 24 are fixedly arranged. The movability of the pairs of bearing blocks 25 will be again described later on.
Furthermore, the fiber sliver 26 is collected or condensed after the last fiber sliver nip line or nip, formed by the rolls 14 and 31, in a funnel or trumpet 53 and is transferred to a rotatably supported pair of calender rolls 54 known as such in this art. The pair of calender rolls 54 consists of a fixedly arranged calender roll 55 and a calender roll 56 which is mounted to be shiftable away therefrom.
The funnel 53 or the like is arranged to be tiltable or pivotable in the direction of the arrow B and protrudes by means of its fiber sliver delivery part 57 into the fiber sliver intake or infeed gap or nip of the pair of calender rolls 54.
When the calender roll 56 is shifted away, then the funnel 53 can be tilted for easier insertion of the fiber sliver 26, delivered from the last pair of coacting rolls 14 and 31, into the funnel 53.
The drafting arrangement 1 additionally can be equipped with a so-called pressure rod or bar 58 (FIG. 5) which is provided in the main drafting zone. This pressure bar 58 positively deflects the fiber sliver, and thus, provides auxiliary guidance of the fiber in the drafting zone. In the context of this disclosure the term positive deflection is to be understood as designating a deflection with a radius extending away from the machine frame 2. The pressure rod or bar 58 in this arrangement is provided in the main drafting zone in such a manner that, as the nip line distance of the main drafting zone, determined by the nip lines of the pairs of rolls consisting of the rolls 13 and 30, and 14 and 31, respectively, is lengthened by rearwardly shifting the pressure roll 30 toward the position indicated with dash-dotted or phantom lines in FIG. 1, the deflection about the pressure bar 58 is reduced. The reduction of the deflection then terminates if a position is reached, in which the distance connecting the pressure rod or bar 58 and the nip line between the rolls 13 and 30 forms a tangent at the circumference of the rolls 13 and 30. This first nip line distance is indicated in FIG. 5 by the arrow E, whereas the maximum nip line distance of, for instance, 85 mm. is reached at the position designated with the arrow F.
If there is used the pressure bar or rod 58, then the pair of bearing blocks 25 is positioned or fixed, respectively, such that the fiber sliver 27 is taken-in tangentially by the rolls 14 and 31.
Furthermore, the drafting arrangement 1, as an alternative to the pressure bar 58, can be equipped with a pressure rod or bar 59 (FIG. 6), which negatively deflects the fiber sliver. When using this solution, the deflection effected by the pressure bar 59 remains constant. In order to ensure for the tangential intake of the fiber sliver by the rolls 14 and 31, also in this alternative arrangement, the pair of bearing blocks 25 is shifted into the position shown in FIG. 6. In this position the upper guide pins 50 (as seen in the viewing direction according to FIG. 1) of the pair of bearing blocks 25 rest against the upper end (not visible) of the guide slot 60 provided in both end or terminal portions 7, whereas in the arrangement using the pressure rod or bar 58, the lower guide pins 50 of the pair of bearing blocks 25 rest against the lower end 61 (FIG. 5) of the guide slots 60.
In this manner the same drafting arrangement is suitable, without having to change any parts, for the utilization of either of the two pressure bar variants.
For lifting the arm elements or parts 4, into the position indicated in FIG. 1 with dash-dotted or phantom lines, constituting the lifted-off threading-in or servicing position, and thus, serving for inserting a fiber sliver into the drafting arrangement, there is used a pneumatic cylinder 62 which is pivotably connected to the machine frame 2. The piston rod end portion 63 of the pneumatic cylinder unit 62 is connected with the two arm parts or elements 4 by means of a rod 64.
For insertion into the drafting arrangement in its lifted-off or open position, the fiber sliver 26 is placed over the bottom rolls and the funnel 53 pivoted in the direction of the arrow B.
By reversing the operation of the cylinder unit 62 the drafting arrangement is again closed, and again locked by reversing the operation of the cylinders 10.
Upon starting the machine at creep speed, the drafted material is inserted into the funnel or trumpet 53 and then into the pair of calender rolls 54. Thereafter, the drafting arrangement can be switched to its normal production speed.
Under the term "short to long staple fibers" there also are to be understood cotton and man-made fibers of a staple length of up to 80 mm.
For those bottom rolls which from the beginning of the pre-drafting zone and the main drafting zone, a diameter of 90 mm is chosen, so that also when processing fibers of 80 mm staple length there can be ensured a wrapping angle of the fiber sliver upon said bottom rolls of maximum 45 angle degrees, as practical experience has shown.
At wrapping angles exceeding an angle of 45° the friction due to the cord wrapping angle between the fiber sliver and the bottom roll becomes too great with conventional fluting of the bottom rolls.
The initially mentioned high sliver speeds cause high centrifugal forces, i.e. high values of angular or radial acceleration.
At a sliver speed of, for instance, 1000 m/min. at the delivery or outlet point of the drafting arrangement, and with a diameter of 90 mm. of the first bottom roll 13 of the main drafting zone and at a draft ratio of 4:1, the angular or radial acceleration reaches a value a r =r·w 2 =385 m/sec 2 , which corresponds to 38 times the (earth) gravitational acceleration.
If, when using a drafting arrangement according to the above-mentioned state of the art, the fiber sliver delivered at 1000 m/min. were to be deflected at an angular acceleration value of a r =385 m/sec 2 , a deflection radius of 720 mm would have to be chosen, which from the standpoint of design considerations would prove unfavorable.
For obtaining, in spite of the favorable large diameter of the first bottom roll 13 of the main drafting zone, an optimally short nip line distance, for drafting fiber material with short staple lengths, the diameter of the second bottom roll 14 of the main drafting zone was chosen to correspond to substantially one-third of the diameter of the first-mentioned bottom roll 13, for instance amounted to 28 mm.
Due to the selection of a small diameter for this roll 14, high rotational speeds are required for the high sliver speeds which on the other hand, result in high values of the angular acceleration. However, since the deflection of the fiber sliver on this roll is zero or does not exceed an angle of a few angle degrees, and since thus no or a very small fiber sliver mass must be deflected, no or relatively small centrifugal forces (Z=m·r·w· 2 ) are generated in the fiber sliver which is closed within itself. The case is different for loose individual fibers, diverted by the roll 14 from the fiber sliver which, as such, is closed within itself. Such fibers are deflected, until a centrifugal force results from the deflected mass, which exceeds the adhesion forces between the fiber and the roll.
In order to counteract possible electrostatic charges built up in the fiber material, there can be used in known manner conventional ionizing devices.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.
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The present invention concerns a method for processing a fiber sliver in a drafting arrangement, and a drafting arrangement for implementing the method. The objective for a drafting arrangement, which can be adapted to a wide range of staple lengths, to draft a fiber sliver at high speeds, has led to the following features of the invention:
(a) The fiber sliver is deflected simultaneously in the drafting process systematically in such a manner that, the fiber sliver can be inserted into the subsequently arranged funnel and the subsequently arranged pair of calender rolls without further deflection.
(b) All bottom rolls are fixedly arranged.
(c) The first pressure rolls limiting the pre-drafting zone and the main drafting zone, respectively, are arranged to be shiftable along an arc about the rotational axis of the corresponding bottom roll in such a manner that the drafting zones are adaptable to the fiber length.
In order to position these pressure rolls accurately in parallelism with respect to the corresponding bottom roll on the arc, there are provided arresting devices co-axially arranged with respect to the arc for taking-up bearing block pairs supporting the pressure rolls.
(d) All pressure rolls as well as the pressure roll mounted on a double arm are jointly pivotable from a lifted-off threading-in position to a working position and vice versa.
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/617,109 filed Oct. 8, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention is directed to an improved pedicle screw and a tubular installation support for spinal stabilization surgery. It is more specifically directed to a threaded screw having a smooth cylindrical barrel at the proximal end and a smooth, narrow pointed distal end. A hollow cylindrical sleeve having interior threads is mated with the screw to support the screw and hold it in alignment during installation.
[0004] 2. Discussion of the Background
[0005] Over the years a number of various types of threaded fasteners have been used in orthopedic surgery to hold bone fragments as well as to reattach ligaments and soft tissue to a bone section. As a result, many innovations have been provided to assist or aid in the installation of the screws into the bone as well as providing various tools and accessories for accomplishing this task.
[0006] This was especially true when it came to surgery on the spine where it was found to be advantageous to install attachment devices in the associated vertebrae to hold the vertebrae in relative position with respect to each other to allow a crack or fracture to mend or a surgical fusion to heal in a relatively short period of time. For many years the usual treatment was to place the patient's spine in traction which required the immobilization of the patient during the healing process. During this time period the patient had to be rotated for physiological reasons from front-to-back and back-to-front in order to minimize ancillary complications and problems. This process in turn had an inherent risk of re-fracturing the spinal fusion potentially prolonging the healing time for the patient.
[0007] To better understand the more recent procedures which have taken place with respect to spinal surgery and stabilization of the spine, it is necessary to note that the “pedicle” is the basal part of each side of the neural arch of a vertebrae. It represents the strong bridge connecting the anterior and posterior portions of a spinal vertebrae. Improvements to the procedure for treating patient injuries or degenerative problems in the back or spine relate to various damage such as a fracture of the vertebrae or damage to spinal discs positioned between the vertebrae. Instead of providing traction as was done in the past, recent prior art methods have been proposed for placing anchors in the pedicle portions of the vertebrae and then provide connecting instrumentation to immobilize or stabilize that affected portion of the spine to allow the bones to fuse and heal. One way of accomplishing this was to provide a metal plate which included a plurality of strategically located holes through which screws were fastened to the pedicle of the vertebrae to immobilize that portion of the spine. Other types of instrumentation to provide the fixation and immobilization of the spine have also been tried.
[0008] One of the major problems in immobilizing the spine to facilitate the healing process has been the complicated procedure for insertion and anchoring of the support screws in the pedicle. In the past, the “stacking on” approach had been utilized for the purpose of installing the pedicle screws via a large open surgical incision. This methodology had many inherent problems since it had a number of intricate steps and the need for accurate placement of each element during these steps increased the operating time and x-ray exposure for both the surgeon as well as the patient. The placement of each element was critical to the success of the healing process. Each step of the insertion of metallic elements requires the verification of placement by a conventional image guidance system, such as an x-ray fluoroscopic inspection. At times, exit penetration of the vertebrae by an element into the abdomen or nerve canal of the patient produced catastrophic results.
[0009] The “stacking on” surgical approach to spinal operations was preceded by a surgical incision located centrally along the posterior spine. This type of incision caused considerable problems from the standpoint that the length of the incision is relatively long in order to allow access by the surgeon into the required vertebrae area. This required retraction of the muscles and soft tissue to provide this access. This standard incision resulted in extensive time required for patient healing as well as problems encountered with scar tissue. The “stacking on” process begins with the insertion of a thin metal guide wire into the pedicle and adjacent vertebral body with fluoroscopic x-ray control. Progressively larger working cannulated tubes or drills are sequentially placed over the guide wire with an ultimate diameter sufficient to insert taps and anchor screws to perform a pedicle screw instrumentation. X-ray verification is required at each step.
[0010] The first or initial element used is the guide wire which must be quite thin. The guide wire is sometimes difficult to place and maneuver, and especially if the patient is large and has a corresponding mass of soft tissue tending to push into the incision. Next a cannulated working tube or drill is positioned over the guide wire and into the incision to effectuate the next step. A bent guide wire can bind inside the tube or drill in the “stacking on” procedure. As the working tube is inserted over the guide wire, the guide wire has been noted to occasionally push forward through the vertebrae and actually penetrate the abdomen. The guide wire can also bind within the tube and can also come out of the track when the exchange of tubes or instruments occurs. When this happens the pathway is lost and a new guide wire penetration must be accomplished to re-establish the alignment of the track. The original incisions were large in order to allow the surgeon to visually guide and position the “stacking on” process for the insertion of traditionally designed pedicle screws.
[0011] It became readily apparent that large incisions were counterproductive to the success of the spinal operation and the healing of the patient. To accelerate the healing of the incision, the incisions became smaller and in some cases were placed several inches on each side of the central portion of the spine to accommodate the surgical procedures. This arrangement further complicated the positioning and insertion of the stabilization instrumentation. Fluoroscopic x-ray position verification of the instrumentation elements became even more critical. The reduction in the incision size and the subsequent reduced damage to the muscle and the soft tissue helped to improve the post-operative condition of the patient but made the surgical procedure even more technically difficult and increased x-ray exposure.
[0012] It became readily apparent to the applicant that an even more minimally invasive procedure for the insertion of the anchor screws for stabilization instrumentation of the lumbar area of the spine would greatly improve the post-operative condition of the patient. For this reason, a pedicle screw insertion which will eliminate the “stacking on” prior art process would be of considerable benefit. In addition, it was realized that a cannulated-type screw or anchoring element was no longer required if the guide wire could be eliminated. Also it was found that it would be highly desirable to include a sleeve to support and hold or retain a self-contained integrally formed pedicle screw that could be inserted directly through a much smaller incision in the skin. The sleeve would further serve to protect the soft tissues from damage by the threaded portion of the pedicle screw.
[0013] This movement towards more minimally invasive spinal surgery has compelled a new look at the design of instruments and implants which were originally manufactured for open stabilization and fusion of the spine. Instrumentation appropriate for situations of open surgery with direct visualization of anatomical landmarks did not necessarily convert for use in minimally invasive solutions.
[0014] These circumstances have led to a radical shift in the approach to instruments and implants now proposed for improved spinal surgery. Rather than using a “stacking on” approach the applicant uses an instrument working sleeve in conjunction with a pedicle screw which is assembled outside the body to provide a single combined integral device incorporating the functions of the guide wire, installation sleeve and pedicle screw implant. This improved apparatus allows a single step establishment of the orientation to the insertion site for the screw and facilitates an additional reaming action for establishing the appropriate track for the screw within the pedicle.
[0015] The single integrated assembly approach allows for a “reverse stacking on” process. Once the pedicle screw has been inserted to the appropriate depth, the working or installation sleeve can be easily withdrawn in a single step. The threaded portion of the sleeve provides a firm fixation for the screw as it is installed with the release of the sleeve as the last threads of the screw exit the sleeve. The reverse is also true for the extraction of the screw when the time becomes appropriate.
[0016] The single assembly approach also allows the use of a more substantial sized guide portion and removes the concerns about complications of the guide wire bending during use. In addition, the novel threaded design of the new installation support sleeve is a departure from the traditional smooth bored sleeves which act as a working portal only. Thus, the threaded nature of the support sleeve helps provide security and stability for single step guidance, insertion and fixation. The support sleeve also can incorporate a guide function for the insertion and rotation of the driver.
[0017] This new improved method requires a significant design change for the pedicle screws as well. The new pedicle screw incorporates a solid guide distal portion of the pedicle screw with a sharp cutting tip and a smooth shaft. The length of the guide portion of the screw is of sufficient length to allow penetration of the lumbar pedicle (approximately 8-10 millimeters). Percutaneous insertion of the screw implant to the depth of the guide portion allows a one step definition of the appropriate track for the pedicle screw. A smooth surfaced cylindrical barrel or stem on the proximal end of the screw provides for attachment of appropriate instrumentation. A low height on this stem portion results in less soft tissue irritation and damage with the use of spine fixation instrumentation.
[0018] Information Disclosure Statement. This section complies with the applicant's requirement to disclose all of the prior art of which he is aware and which may apply to the examination of the present application.
[0019] The Stednitz et al. patent (U.S. Pat. No. 5,098,435) discloses a bone stabilizing system which includes a fixation device which comprises a metal cannula defined by a hollow cylindrical shaft having drilling teeth at one end and a receiving device at the other end and a plurality of threads therebetween. A solid non-cannulated embodiment of the fixation device is also shown. Intersecting a portion of the threads is at least one flute which is defined by two substantially orthogonal surfaces and an elongated slot which penetrates the wall of the cannula so as to provide fluid communication.
[0020] The Konieczynski patent (U.S. Pat. No. 6,183,478) discloses a device for affixing a bone plate to spinal bone which includes a sleeve, bias member and a fixation member. The fixation member is a screw-type device. The elongated hollow sleeve does not have any internal threads and the inner diameter is greater than the fixation device. The fixation member is housed within the sleeve and during installation is pushed out through the distal end of the sleeve in order to contact and engage the bone through the bone plate.
[0021] The Walawalkar patent (U.S. Pat. No. 5,904,685) discloses an apparatus for inserting a screw into a tunnel in a surgical site. The apparatus includes a screw which is inserted in a cannulated sheath or sleeve for guiding the insertion of the screw. A protrusion on a cantilevered arm formed in the wall of the sheath temporarily holds the screw in position at the distal end of the sheath during insertion. This protrusion is relatively flexible and merely holds the screw in place within the sheath. It does not stabilize or aid the support or alignment of the screw during the insertion process.
[0022] The Coleman patent (U.S. Pat. No. 5,645,547) also shows a cannulated screw which is inserted or installed onto a keyed rotatable insertion shaft. The shaft has a point on the end which is used to provide a guide tunnel for insertion of the screw.
[0023] The Fucci patent (U.S. Pat. No. 5,607,432) discloses a retriever for removing a threaded bone anchor from an implantation site. The retriever comprises an elongated shaft having an anchor engaging means at its distal tip for engaging the drive portion of the threaded bone anchor and for turning it in a direction to remove it from the implantation site. A concentric anchor engaging sleeve is adapted to move longitudinally relative to the elongated shaft in order to engage the threaded body of the anchor as it is removed from the implantation site. The sleeve has one or two internal threads which engage the anchor upon its retrieval so that it will be retained within the sleeve so that the anchor can be removed from the implantation site.
[0024] The Simon et al. patent (U.S. Pat. No. 6,415,693) and Leibinger et al. patent (U.S. Pat. No. 4,763,548) show sleeve-type screwdrivers which are used to retain fixation devices such as screws during orthopedic surgery. Both of these devices comprise a gripping sleeve at the free end of the device which has a radially expandable portion for receiving and holding the screw. The expandable or gripping portion in both patents is effective by sliding a sleeve longitudinally with respect to the gripping or expandable portion. A handle is axially movable to engage the screw or fixation device so that it can be rotated for insertion into the bone. Neither of these patents disclose the use of full length threads provided internally within the sleeve for retention of the screw or fixation device during the installation process.
SUMMARY OF THE INVENTION
[0025] The present invention is directed to a minimally invasive pedicle screw and guide support sleeve for insertion of the screw. The screw in this context is intended as an anchor for support of instrumentation to stabilize and support vertebrae in the spinal column to allow fusion and healing within the spine. It is to be understood that although the discussion herein is directed to surgical procedures with the spine it is also possible that the anchor screw and guide support described herein can be used in various types of orthopedic surgery dealing with anchoring and fusion of the bone as well as the attachment of ligaments and tendons to the bone.
[0026] This system is composed of a novel self-boring, self-tapping integral screw having a distal sharply pointed end for guiding the insertion of the screw as well as forming the preliminary borehole for the self-tapping threads of the screw.
[0027] The proximal end of the screw provides a smooth cylindrical barrel which can include a recess in the end for receiving a rotational drive tool or wrench. The body of the screw incorporates an elongated portion which is suitably threaded to allow the screw to be inserted into the pedicle portion of the vertebrae and rigidly anchored. The first several threads are self-tapping threads provided on the distal end of the threaded portion of the body which allows the threads as they are turned to cut into the bone matter and self-tap the inner surface of the borehole formed by the guide portion of the screw.
[0028] One or more longitudinal flutes can be provided partial or full length along the threaded body portion of the screw to allow relief of the bone matter cut by the self-tapping threads as the screw is inserted into the bone.
[0029] A relatively thin hollow support sleeve or tube is provided which includes an internally threaded section which matches the threads and the length of the threaded portion of the pedicle screw. The distal end of the sleeve has a rounded or beveled edge so as to minimize soft tissue injury or damage that is caused by the insertion of the pedicle screw and the sleeve percutaneously during the installation process.
[0030] The proximal end of the sleeve has an internal diameter that can match the diameter of the barrel or stem portion of the screw or can be substantially larger than this diameter to allow the insertion of a drive tool which can have a hexagonal coupler in its end which will mate with a hexagonal drive portion provided at the proximal end of the threaded portion of the screw. It is readily apparent that any type of suitable drive coupler or connection can be used for engagement of the drive tool with the pedicle screw as desired. The internal diameter of the proximal end of the support sleeve can be varied to accommodate different types of drive devices.
[0031] The pedicle screw as described herein is intended to provide an anchor for instrumentation that can be used to interconnect the stem portion of a plurality of pedicle screws provided in the vertebrae of a patient's spine. The instrumentation can include rods having various lengths which are attached to the stem portion of the screws for stabilizing and fixating the vertebrae of the spine of the patient which will allow the spine to quickly heal without the tissue trauma normally encountered with extensive percutaneous spinal surgery. The use of the support sleeve in conjunction with the installation of the pedicle screw is critical in that the screw is firmly held within the sleeve as the sleeve is inserted through a small incision in the skin over the pedicle portion of the vertebrae so that the soft tissue and muscle is not further damaged by the threads of the screw during rotation and insertion of the pedicle screw and the screw remains properly aligned.
[0032] The support sleeve can be reused for the insertion and withdrawal of any number of pedicle screws during the surgical process which minimizes the cost of this procedure as well as providing minimally invasive insertion of the pedicle anchor screws required for the stabilization and healing of the patient's spine.
[0033] The support sleeve in conjunction with the shaft of the drive tool used for driving the screw can incorporate indices or marks on the shaft of the drive tool which correspond with the threaded length of the pedicle screw during the insertion process. The indices can also take the form of peripheral slots formed in the shaft of the tool at various predetermined locations along the shaft which identify the depth of the pedicle screw during the installation. A retainer clip or locking ring having an extended handle can be inserted into the peripheral slots on the shaft of the tool with one coinciding with the proximal end of the support sleeve. In another arrangement, slots can be provided through opposite sides of the support sleeve which align with a circumferential slot on the driver tool so that the retainer clip will temporarily lock the drive tool and the pedicle screw with respect to the support sleeve. This locking process provides a rigid assembly prior to the installation and insertion of the screw with the retainer clip repositioned to the proper slot on the shaft of the drive tool upon the start of the insertion process. In this way the retainer clip will limit the insertion depth of the pedicle screw to prevent the screw from being inserted to a position where it could exit the pedicle portion of the vertebrae and enter the abdominal cavity of the patient. Other indices or marks can be provided strategically along the shaft of the drive tool or the sleeve to provide indication of various depths of the screw as it is inserted.
[0034] In another embodiment of the invention, a locator rod can be incorporated into the assembly so as to project or predict the location and depth of the orthopedic screw prior to its installation. In most cases, the screw and driver device are aligned along a single longitudinal axis. A thin central passageway can be formed to coincide with the longitudinal axis of the assembled screw and driver. A thin rod is then slidably positioned within the central passageway. The rod includes a sharp point at the distal end and an enlarged knob or stop at the opposite proximal end. The length of the rod is predetermined as the combined length of the screw and driver plus the length of the threaded portion of the screw.
[0035] With the assembly properly positioned and aligned with respect to the bone mass, the rod is tapped with a small instrument to force the rod into the bone until the rod stop contacts the end of the driver. An image guidance system can be used to verify the location and depth of the distal end of the locator rod with minimum exposure to the patient and surgeon. The locator rod then projects the future position of the screw prior to its actual installation. If desired, spacer disks can be installed over the rod to limit the penetration depth of the locator rod if only a partial thread depth penetration of the screw is intended.
[0036] The present invention has been briefly described herein but it is understood that other aspect and features of the invention may become apparent from the following detailed description of the invention when it is considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a pictorial view showing an x-ray image of the spine of a patient with the insertion of a plurality of pedicle screws according to the present invention;
[0038] FIG. 2 is a side partially sectioned view of the lumbar area of a patient's spine showing the insertion of a plurality of pedicle screws;
[0039] FIG. 3 is an enlarged pictorial view of the pedicle screws displayed in FIG. 2 along lines 3 - 3 ;
[0040] FIG. 4 is a side pictorial view of the pedicle screws inserted in the vertebrae of the patient's spine as shown in lines 44 of FIG. 1 ;
[0041] FIG. 5 is a cross-section of a vertebrae of the patient's spine showing the placement of the pedicle screws according to lines 5 - 5 of FIG. 4 ;
[0042] FIG. 6 is an assembly view of the pedicle screw insertion system of the present invention;
[0043] FIG. 7 is a partially assembled view of FIG. 6 showing the pedicle screw threaded into the support sleeve;
[0044] FIG. 8 is the assembled view of the pedicle screw insertion system according to the present invention;
[0045] FIG. 9 shows a cross-section view of the assembled pedicle screw taken along lines 9 - 9 of FIG. 8 ;
[0046] FIG. 10 is a cross-section view taken along lines 10 - 10 of FIG. 8 ;
[0047] FIG. 11 is a cross-section view taken along lines 11 - 11 of FIG. 8 ;
[0048] FIG. 12 is a cross-section view taken along lines 12 - 12 of FIG. 8 ;
[0049] FIGS. 13-15 are pictorial views showing the insertion of the pedicle screw into the vertebrae of a spinal column;
[0050] FIG. 16 is a perspective view of a pedicle screw insertion system showing a transverse handle provided on the support sleeve;
[0051] FIG. 17 is a perspective view of the system disassembled showing a hexagonal ring on the screw above the threaded portion with a hexagonal socket provided on the drive tool;
[0052] FIG. 18 is a sectional view showing the hexagonal receptacle on the drive tool engaging the hexagonal ring on the pedicle screw with the drive tool also engaging a receptacle in the proximal end of the screw;
[0053] FIG. 19 is a perspective view showing indicia slots provided on the shaft of the drive tool with a retainer clip installed;
[0054] FIG. 20 is a perspective view of the retainer clip shown in FIG. 19 ;
[0055] FIG. 21 is a partial sectional view showing the drive tool and the retainer clip inserted into the support sleeve with the pedicle screw partially extended;
[0056] FIG. 22 is the assembled view of the pedicle screw insertion system which includes the locator rod embodiment;
[0057] FIG. 23 is the assembled view as shown in FIG. 22 wherein the locator rod extends beyond the proximal guide end of the pedicle screw to provide the projected location of the installed screw;
[0058] FIG. 24 is a cross section taken along lines 24 - 24 of FIG. 23 ;
[0059] FIG. 25 is a side cross sectional view of the assembled pedicle screw insertion system showing the locator rod; and
[0060] FIG. 26 is an enlarged partial sectional view showing the rod and its depth controlling cap.
DETAILED DESCRIPTION OF THE INVENTION
[0061] Turning now more specifically to the drawings, FIGS. 1-5 show a partial pictorial view of a patient's body B revealing the position of the spinal column S, the pelvis bone H as well as the individual vertebrae V which makes up a portion of the spine. Intervertebral discs D which are positioned between each of the vertebrae V go together to protect and support the spinal cord and nerves C positioned within the structure making up the spinal column S.
[0062] In each of the views is seen a pedicle or orthopedic screw 20 which has been strategically positioned and installed within the pedicle portion of certain vertebrae V. The primary purpose of the pedicle screw 20 is to provide a rigid anchor in the affected and adjacent vertebrae so that the vertebrae can be rigidly supported within the spinal column S to stabilize the vertebrae V to allow the fusion of fractured vertebrae as well as to allow healing of damaged or ruptured discs D that may be present in the spinal column S. Instrumentation in the form of rods rigidly connected to the stems 26 of the installed pedicle screws 20 are joined together to form a rigid lattice-type network (not shown) to stabilize and fixate the components of the spine to prevent or at least minimize any further movement or damage and to promote healing. The instrumentation that provides this fixation and stabilization of the spine is well known and therefore will not be further discussed in this application.
[0063] As seen in FIGS. 6-12 the pedicle screw and guide sleeve system 10 is shown in various views. The system 10 includes the pedicle screw 20 , the guide support sleeve 30 and the driver 40 . The pedicle screw includes a threaded central body portion 22 , a distal guide end 24 along with a sharp pointed cutting end 25 and a proximal, smooth cylindrical barrel or stem 26 . A suitably configured socket or drive recess 28 is provided in the stem 26 for receiving and coupling with the drive tip 42 of the driver 40 . The guide support sleeve 30 includes the hollow cylindrical body 32 which includes an internal threaded portion 34 which matches the threads and the length or at least a partial length of the threaded body 22 of the pedicle screw 20 . Varying lengths of sleeve 30 can be manufactured to fit different depths of soft tissues encountered in patients. The balance of the cavity in the guide support sleeve has an internal diameter at least large enough to slidably receive the shank 44 of the driver 40 .
[0064] The pedicle screw 20 has a relatively narrow diameter cross section with respect to its overall length. The small diameter of the pedicle screw 20 which is approximately 5-8 mm is desirable from the standpoint that the screw can provide adequate seating within the bone structure for the purpose of anchoring the instrumentation without producing excessive lateral stress on the bone during the thread cutting process which could cause the bone to split or fracture inflicting additional trauma and injury on the patient. Various diameters of the threshold screw are manufactured to accommodate different patient sizes.
[0065] As seen in FIG. 6 the distal guide end 24 of the pedicle screw 20 is approximately 10-15 millimeters in length while the threaded body portion 22 is approximately 25-60 millimeters in length to accommodate varying patient size requirements. The smooth stem portion 26 also has a length of approximately 10-20 millimeters. Thus the guide end 24 and the stem end 26 have a ratio of approximately 1:4 and 1:2, respectively, with respect to the threaded body portion 22 of the pedicle screw 20 . These dimensions can vary depending upon the overall size of the patient. The outer end 25 of the guide 24 converges into a sharp point and has a plurality of sharp edges making up the point. Thus, as the pedicle screw is rotated the sharp edges cause a boring or reaming effect which opens up an aperture or bore in the bone to allow introduction of the cutting threads 23 of the threaded body portion 22 .
[0066] The cutting threads 23 are of the self tapping configuration which are well known in the art and provide a thread cutting function in the bone mass as the pedicle screw is rotated. In most cases the configuration of the threads in the body portion 22 and the cutting threads 23 will be of the right hand configuration so that the cutting function will take place as the screw is turned clockwise as viewed from its proximal end 26 .
[0067] As will be discussed later, it is also possible to provide one or more longitudinal flutes or slots 125 along at least part or the entire length of the threaded body portion 22 of the pedicle screw 20 in order to allow the bone chips and debris that are produced during the thread cutting process to be moved longitudinally backward along the screw so as to provide relief for the removal of the debris.
[0068] In preparation for use, the pedicle screw 20 is reverse threaded into the end of the internal threaded bore of the guide support sleeve 30 so that the uppermost or proximal threads of the pedicle screw 20 will engage the innermost internal threads of the support sleeve 30 . Since the length of the internal threads in the sleeve match the screw threads, the screw threads are concealed within the sleeve during placement and installation. Thus, the pedicle screw 20 is firmly seated, housed and supported within the support sleeve 30 . The driver 40 can be used to assemble the pedicle screw within the sleeve 30 by insertion of the shank 44 into the interior cavity 36 of the support sleeve 30 . In this way the engagement or drive end 42 of the driver 40 is inserted into the recess 28 provided in the proximal end of the pedicle screw 20 and the screw 20 is then turned backwards to thread it into the sleeve. The system 10 is properly assembled when the pedicle screw 20 is fully inserted within the support sleeve 30 and the driver 40 is inserted to engage the pedicle screw. In this configuration the pedicle screw and guide support assembly 10 is ready for percutaneous installation into the desired location within a vertebrae.
[0069] FIGS. 13-15 shows the actual use of the assembled components or system 10 for installation of the pedicle screw 20 into the bone mass. The guide end 24 of the pedicle screw 20 assembled within the guide support sleeve 30 along with the driver 40 is positioned in contact with the bone mass or vertebrae through a small incision made through the skin and soft tissue of the patient. Once the pedicle screw is properly positioned, the sharp point 25 of the distal end 24 of the screw can be set in the surface of the bone by a light tap on the handle of the driver 40 either by the hand of the surgeon or by a small light weight instrument.
[0070] Once the pedicle screw 20 is properly positioned and set and the system 10 is aligned with the respective vertebrae, the driver 40 is then rotated in a clockwise direction as shown by arrow A along with the application of longitudinal force on the driver 40 . This action rotates the guide 24 with the cutting point 25 causing the reaming of an opening or aperture in the pedicle area of the vertebrae V. This continuous rotation of the pedicle screw 20 , support sleeve 30 and driver 40 quickly generates an aperture through the dense outer layer of the bone structure and into the softer inner nucleus of the vertebrae. The continuous rotation of the driver 40 causes the cutting threads 23 of the screw 20 and the distal edge of the sleeve 30 to engage the surface of the bone and the screw 20 to cut new additional threads into the aperture reamed by the guide end 24 . The support sleeve 30 stops rotating upon contacting the bone and is then held rigid and new threads are cut through the outer dense layer of the bone structure as the screw emerges from the sleeve.
[0071] The continued rotation of the driver 40 causes the screw 20 to extend further outward from the support sleeve 30 guiding the screw 20 into the newly formed aperture in the vertebrae. The screw 20 can be threaded entirely into the vertebrae or if desired can be turned leaving a predetermined portion of the threaded body 22 of the screw 20 exposed above the surface of the vertebrae V. When the threads are partially exposed it is then necessary to turn the support sleeve backwards so as to withdraw the support sleeve from the uppermost part of the screw. Once this has been accomplished the support sleeve 30 and driver 40 are then easily retracted leaving the pedicle screw 20 firmly anchored within the bone structure of the vertebrae. The use of the support sleeve 30 during the rotational insertion of the pedicle screw 20 into the vertebrae keeps the threads of the screw from coming in contact with this tissue during installation which can cause extensive damage and irritation during the surgical procedure.
[0072] FIG. 16 shows another embodiment of the support sleeve 80 which includes all of the attributes of the previously described support sleeve 30 except that a handle or grip 82 is provided extending transversely from the upper end of the support sleeve 80 . It is desirable that a suitable grip be provided on the support sleeve 80 in order to firmly hold the sleeve 80 during the installation of the pedicle screw 20 . The handle 82 facilitates the alignment and positioning of the sleeve 80 even though the sleeve 80 may become difficult to secure due to fluids that may be present during the surgical procedure.
[0073] Another embodiment of the pedicle screw and guide support sleeve of the present invention is shown in FIG. 17 . In this embodiment, a double drive configuration is provided for the coupling between the pedicle screw 120 and the driver 140 . The pedicle screw 120 includes the threaded body 122 , smooth cylindrical stem 126 and a drive socket recess 128 . The driver shank 144 is slightly greater in diameter than the previous embodiments with the driver tip 142 recessed within a hollow cavity 147 at the end 149 of the driver shank 144 . The inner surface of the drive cavity 147 includes a hexagonal socket 148 formed near the outer edge 149 of the shank 144 . The area above the threads of the pedicle screw 120 is formed into a hexagonal drive coupling 121 which forms the transition between the threaded body portion 122 and the stem 126 . The internal cavity 147 formed in the outer end of the driver shank 144 has a diameter large enough to pass over the outer surface of the stem 126 . Thus, to make the drive connection between the driver 140 and the pedicle screw 120 , the driver shank 144 is inserted over the stem 126 . The distance between the drive tip 122 and the hexagonal socket 148 is arranged to coincide with the distance between the hexagonal drive coupling 121 and the receptacle 128 on the pedicle screw 120 . It is to be understood that even though a double drive connection is provided only one or the other of the drive tip 142 or the hexagonal socket 148 may be necessary depending upon the strength of materials utilized in forming the driver shank 144 and the pedicle screw 120 . This decision can be made and based not only on the materials that are used in the fabrication of these components but also on the type of orthopedic surgery that is anticipated as well as the bone mass that is to be encountered.
[0074] It is also to be noted in FIG. 17 that a longitudinal flute 125 can be provided either partially or the full length of the threaded body portion 122 of the pedicle screw 120 in order to provide relief for the removal of the bone chips or debris that is produced during the thread cutting process when the pedicle screw 120 is installed into the vertebrae or other bone mass. This debris is moved into the support sleeve 30 where it can be removed along with the sleeve. It has been found beneficial to provide relief for this debris which then allows the bone chips and debris that are formed during the threading process to be moved away from the cutting threads so that the cutting threads will not be clogged or bound by the bone material.
[0075] FIGS. 19-21 show another embodiment of the present invention in which lines or indices are spacedly scribed along the shank of the driver 240 . In some cases these marks can be peripheral slots 245 provided around the shank 244 of the driver 240 which are sized to receive a clip retainer or locking ring 250 .
[0076] The locking ring 250 includes a handle portion 252 and outer bifurcated ends 254 . The outer ends 254 circumscribe a partial circle and converge slightly towards each other so that the ends can pass around the circumference or slots 245 formed in the shank 244 of the driver 240 . In this way the locking ring 250 can be slidably inserted and held in any one of the slotted grooves 245 .
[0077] Once the pedicle screw 20 is inserted into the supportive sleeve 230 , the driver 240 can be inserted into the sleeve 230 to mate with the upper end of the pedicle screw 220 . When the driver is positioned the locking ring can be inserted into the correct circumferential slot 245 which has a distance from the upper edge 239 of the support sleeve 230 to match the length of the threads on the pedicle screw 20 . The driver 240 is then rotated until the locking ring 250 contacts the upper edge 239 of the support sleeve 230 . At this point the pedicle screw 20 has been installed a predetermined distance into the vertebrae V. In this way, the pedicle screw can not be driven too far into the vertebrae wherein the guide end 24 of the pedicle screw might penetrate and exit the vertebrae.
[0078] In addition, by strategically positioning a pair of slots 237 on each side of the support sleeve 230 a locking ring 250 can be inserted around the outer circumference of the sleeve 230 to properly engage one of the peripheral slots 245 formed in the shank 244 of the driver 240 . In this way the driver can be locked within the support sleeve 230 which secures the three components together in their properly assembled position. In this way the pedicle screw and support sleeve system is rigidly held together in preparation for the surgical installation of the pedicle screw. Once the system has been properly positioned subcutaneously, the locking ring 250 is removed from the outer surface of the support sleeve 230 allowing the driver 240 to be freely rotated for the installation of the screw. Prior to the threading process, the locking ring 250 can be repositioned in one of the exposed peripheral slots on the shank 244 at the proper distance to limit the length of the threaded portion of the pedicle screw that is to be inserted within the vertebrae.
[0079] It is to be understood that the spacing between the peripheral slots 245 is expected to be relatively equal in units that are anticipated to be required for insertion of various lengths of the pedicle screws that are to be used. This is also determined by the overall length of threaded body portion of the pedicle screw which can vary depending upon the overall size and weight of the patient. The dimensions of the pedicle screw 20 can also be varied such as by lengthening or shortening of the guide end 24 as well as the stem end 26 . In addition, the number, pitch and type of threads in the body portion 22 can be varied depending upon the anticipated type or condition of the bone, various bone densities and the required depth of the installed pedicle screw. In conjunction with the length of the threaded portion 22 the overall diameter of the screw in these various areas can also be adjusted either larger or smaller depending upon the anticipated size of the bone configuration within the spinal column S. It is anticipated that the overall number and size of the various pedicle screws 22 , support sleeves 30 and corresponding driver 40 can be optimized to a reasonable number of combinations to cover a wide range of patient sizes that are normally anticipated.
[0080] One of the problems that has been encountered in the past in the installation and insertion of orthopedic screw type threaded fasteners has been the guidance and verification of the fastener as it is being inserted into the bone mass. The difficulty here is to verify and be certain that the screw has not inadvertently exited the bone mass which in turn could cause traumatic damage to the internal organs of the body and in some cases catastrophic results. In order to accomplish this several types of image guiding systems can be employed to verify the insertion. One is the use of fluoroscopic x-ray equipment to provide continuous x-ray observations of the bone mass as the orthopedic screw is inserted. One of the major problems that occurs here is the fact that the x-ray projection is two dimensional and provides no depth perception with respect to the location of the screw and also provides extensive x-ray exposure to the patient as well as the surgeon. Another is a computer display generated by computer axial tomography, commonly called a “CAT scan” which provides a three dimensional view of the bone mass where the orthopedic screw is being installed. These image guidance systems are not continuous and instantaneous and only provide a spaced series of displays which are not real-time but are actually delayed exposures during the insertion process. Thus, the present state of the art does not provide a completely adequate guidance system to provide absolute confidence that the screw will not exit the surface of the bone mass.
[0081] In order to overcome this situation the present invention includes a manual locator device which is used prior to the actual insertion of the screw by providing an accurate projection of the screw as to depth and location prior to the actual insertion of the screw. In this way the position and alignment of the pedicle screw 322 and installation sleeve 330 can be verified prior to the actual implementation. The position of the locator rod can be accurately determined by the existing image guidance systems. In this way it can be easily determined that the screw is properly aligned and has sufficient clearance to not exit the surface of the bone mass.
[0082] To accomplish this a very thin cylindrical channel or passageway is formed completely through the screw installation system which means that the channel or passageway follows the longitudinal axis through the center of the driver handle 346 , shank 340 and pedicle screw 322 . The channel 341 exits through the distal guide end tip 325 and provides a clear passageway through the entire assembly for the locator rod 343 . An installation cap 345 has a body 347 which is sized to slidably fit within the cavity 350 provided in the outer end of the handle 346 for the driver 340 . A centrally positioned hole 354 can be provided within the body 347 of the cap 345 . The outer end of the cap 345 includes an enlarged end portion 349 which has a flat under surface 350 . The location rod 343 extends upwardly so that the end of the rod engages the cap 354 in the central hole 347 . The locator rod 343 and cap 345 can be left as two separate parts or the rod can be attached to the cap within the hole 347 through the use of any attachment arrangement desired, such as a suitable adhesive. The actual length of the rod 343 and cap 345 is critical to the desired function of the device. The distal end of the rod 343 includes a sharpened point so that it can easily penetrate the bone mass upon insertion.
[0083] The length of the rod assembly is determined by measurement of the outer end of the distal guide end 325 of the screw 322 , along the longitudinal axis of the screw and the driver 340 to the upper end of the hole 352 formed in the rod installation cap 345 . For this measurement the installation cap 345 is precisely positioned within the cavity 350 . The clearance distance between the top surface 351 of the drive handle 346 and the bottom surface 350 of the cap 345 is designed to precisely equal the length of the threaded portion of the pedicle screw 322 . With the cap 345 held precisely in this position the rod is then measured to contact the upper end 354 of the hole 352 and then is cut precisely to this length. Thus, the end of the locator rod 343 is aligned with the end of the guide tip 325 as the proximal guide tip 320 is rotated and inserted into the outer surface of the bone mass until the end 323 of the installation sleeve 330 is in contact with the surface of the bone mass. With the pedicle screw installation assembly properly aligned the locator cap 345 is gently tapped by a suitable instrument to force the locator rod 343 into the bone mass until the lower end of the cap 350 contacts the top 351 of the driver handle 346 .
[0084] With the locator rod 343 is positioned within the bone mass an image guidance system is then employed to accurately determine the precise location of the tip 358 of the locator rod 343 . This accurately projects the precise location of the guidance tip 325 of the pedicle screw 322 after it has been inserted into the bone mass. The locator rod 343 is then withdrawn after the projected location for the screw has been determined.
[0085] It is also possible to provide additional adjustments to the actual depth and travel of the rod and cap by providing spacer disks 364 . The disks 364 can have a central aperture which fits the outer diameter 348 of the body 347 of the cap 345 which allows the cap 345 to slide longitudinally with respect to the handle of the driver 340 . The actual thickness of the disks 364 can be precisely determined to correspond with any number of threads of the pedicle screw 322 so as to actually limit the depth of the guide rod 343 , if it is predetermined that only a certain number of threads will be inserted into the bone mass. In this way the depth of the location rod can coincide with the anticipated actual depth of the installed screw. It is understood that a number of disks 364 can be used for this purpose to adjust the final depth of the locator rod during its insertion. It is also understood that the disks can be sized to be inserted internally within the cavity 350 of the driver handle 346 and provide a similar function within the driver cavity 350 with respect to the movement of the cap 345 .
[0086] It is important that the material which is used to fabricate the locator rod 343 must be compatible with bone and body tissue. The material must be extremely rigid and of high strength so that it will not bend or be deflected as it is forced into the bone mass. On the other hand it cannot be of a brittle nature which would allow it to possibly break off during insertion and leave it irretrievable embedded in the bone mass.
[0087] It is preferred that the components of the support sleeve and most especially the pedicle screw will be formed from a suitable rigid, non-corrosive material such as stainless steel or titanium or other materials such as synthetic resins, ceramics or rigid plastics. It is anticipated that any material can be used which meets the rigidity and strength requirements and is compatible with the patient's tissue. The handle 46 of the drive tool 40 can be of the ratcheting type which allows easier and more leveraged rotation of the drive tool during the surgical procedure. As an alternative an electric drive motor such as an electric drill can be attached to the screw assembly to provide the driving force.
[0088] The above disclosure sets forth a number of embodiments of the present invention described in detail with respect to the accompanying drawings. Those skilled in the art will appreciate that various changes, modifications, or other structural arrangements and other embodiments could be practiced under the teachings of the present invention without departing from the scope of this invention.
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A minimally invasive orthopedic bone attachment system comprising a pedicle screw and guide support sleeve for insertion of the screw. The pedicle screw is a self-boring, self-tapping integral screw having a distal sharply pointed end for guiding the insertion of the screw as well as forming a borehole for the self-tapping threads of the screw. The proximal end of the screw provides a cylindrical extension which can include a recess for receiving a rotational drive tool or wrench. The length of the threads and the type of threads provided in the screw are designed for the type of orthopedic surgery that is intended. A relatively thin hollow support sleeve including an internal threaded section in the distal end is provided to match the threads and the length of the threaded portion of the pedicle screw. The proximal end of the sleeve includes a central passageway having an internal diameter that can receive the extension portion of the screw and also guide and receive a drive device for the screw. A retainer clip associated with circumferential slots spacedly indexed along the longitudinal surface of the drive device can be used to limit the depth of the screw upon insertion as well as to lock the drive device as an assembly with the screw and sleeve to form the attachment system. A small diameter passageway can be provided along the longitudinal axis of the assembly extending from the proximal end of the drive device through the screw to exit through the pointed distal end of the screw. A thin rigid rod having a point at the distal end is slidably positioned within the narrow passageway. The proximal end of the road includes a cap. A flange surface on the under portion of the cap limits the travel of the rod through the assembly. The length of the rod is determined so that it equals the length of the assembly plus an additional dimension corresponding to the anticipated installed depth of the screw. Prior to insertion of the screw, the rod is driven into the bone through the assembly. The location of the rod is ascertained by an image guidance system to determine the correct final projected location of the screw upon installation.
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BACKGROUND ART
The present invention generally relates to the treatment of semiconductor materials intended for microelectronics and/or optoelectronics applications. In particular, it relates to a method of preparing the surface of a thin film having a thickness in the range of about 1 nanometer (nm) or a few tens of nm to about 100 nm or a few hundred nm, for example 400 nm or 500 nm. More particularly, the invention relates to preparing the surface of a film of monocrystalline silicon carbide so that it is “epiready”, meaning that the surface is ready for epitaxy, i.e., to receive growth of an epitaxial film thereon. In an implementation, the film may be a silicon carbide film transferred onto a further material (silicon, monocrystalline or polycrystalline SiC covered with an oxide or other film such as deposited oxide, nitride, etc).
In order to obtain good quality epitaxy, the starting surface must be free of defects and must be as smooth as possible. A thin layer transfer method is known for transferring thin SiC films, and is known as the SMART-CUT® process (or substrate fracture method). This well known method is described, for example, in an article by A. J. Auberton-Hervé et al entitled “Why Can SMART-CUT® Change the Future of Microelectronics?”, International Journal of High Speed Electronics and Systems, Vol. 10, no. 1, 2000, pages 131–146. After detachment, that method results in a roughness value of about 5 nm root mean square (rms), which is not compatible with epitaxial growth. The roughness value must be reduced to about 1 nm to 2 nm rms by applying thermal oxidation-type treatments (known as annealing) and/or ion etching. However, it has been observed that such techniques cannot produce the desired final roughness value (of 0.1 to 0.2 nm rms) for epitaxy on SiC.
The annealing step does not consume sufficient material to significantly reduce the roughness value since thermal SiC oxidation is very slow, especially on the silicon face. Further, it is difficult to conduct chemical-mechanical polishing (CMP) of SiC since the chemical reactivity of the polished surfaces is low compared with materials such as silicon. In addition, the removal rate is very low, on the order of 10 nm per hour, as compared to about 50 nm per minute for silicon polishing. Further, the mechanical hardness of SiC is extremely high and the use of “diamond” abrasives or certain other abrasives that are known for polishing silicon may result in scratches. Thus, it is difficult to find an abrasive to use which results in a sufficiently high removal rate without creating scratches and defects. Hence, SiC polishing methods are often very lengthy (several hours). Further, abrasives based on diamond particles cannot produce the desired roughness of less than 1 nm rms. For these two reasons, SiC polishing techniques are very precise, and few SiC substrate polishing methods are known.
U.S. Pat. No. 5,895,583 describes a polishing method that uses several successive steps. Several steps are necessary to remove work hardened zones generated by each polishing step. That method uses abrasives based on diamond-containing particles having decreasing diameters.
French patent application No. 02-09869 describes a method employing a mixture of abrasives (diamond/silica) that can produce roughness compatible with molecular bonding.
Techniques other than polishing exist that are capable of producing a low roughness surface. The majority of such techniques are based on bombarding the surface with ions from a plasma (RIE) or a beam (for example gas cluster ion beam), a technique that is described in U.S. Pat. No. 6,537,606. Such techniques are of interest concerning the removal rates, but the surface condition is often too rough for epitaxy, and in particular, the surface cannot be easily smoothed.
Thus, there is a need to develop a method of treating or preparing the surface of a film, in particular a silicon carbide film. It would also be beneficial to find a method of treating films, in particular silicon carbide films, that can produce low roughness, and/or that can produce a sufficient removal rate without creating scratches or defects. It would also be advantageous to develop a method of treating silicon carbide films which can produce low roughness, preferably of less than 15 angstroms (Å), or 10 Å rms or 5 Å rms or 1 Å rms, which are compatible with epitaxial growth.
SUMMARY OF THE INVENTION
The invention relates to a method for preparing a surface of a semiconductor wafer so that it is epiready. The technique includes annealing the wafer in an oxidizing atmosphere to condition the surface; and polishing the conditioned surface of the wafer with an abrasive based on particles of colloidal silica in order to provide a wafer surface that is suitable for growing an epitaxial layer thereon. Advantageously, the wafer surface is prepared so that it is suitable for homoepitaxy or heteroepitaxy. In a preferred embodiment, the surface of the wafer comprises SiC, such as in the form of a SiC surface layer that is bonded to a semiconductor substrate.
In a preferred embodiment, the annealing is conducted at a temperature in the range of about 1000° C. to about 1300° C., and more preferably at about 1150° C. Annealing is generally conducted for about 1 hour to about 3 hours. The method may further include at least one of deoxidizing the wafer surface or utilizing an RCA (SC1, SC2) type chemical cleaning step. This is generally conducted after annealing and prior to polishing. Hydrofluoric acid may be used to deoxidize the wafer surface. The method may also advantageously includes chemically cleaning the wafer surface prior to polishing, wherein hydrofluoric acid may be used for cleaning. If desired, the wafer surface can be etched with ions prior to polishing.
A preferred type of colloidal silica for polishing the wafer surface is SYTON W30 type colloidal silica. Also, it is desirable to use a polishing head rotating at a rate in the range of about 10 rpm to about 100 rpm to polish, optionally with a pressure in the range of about 0.1 bar to about 1 bar applied to the polishing head. Polishing typically occurs for a period in the range of about 15 minutes to about 30 minutes. If desired, an IC1000 type polishing pad can be used.
An advantageous aspect of the includes annealing the wafer in an oxidizing atmosphere and then inserting the wafer into a polishing head. Next, a liquid abrasive based on colloidal silica can be applied or injected onto the wafer surface, and then applying a pressure and a movement to the polishing head to polish the wafer surface against a polishing pad.
The invention utilizes steps and machines that are standard in microelectronics to rapidly provide an epiready semiconductor surface. The invention is particularly advantageous when applied to SiC substrates, for example of polytype 4H, which are used for epitaxial growth, and can be used to fabricate electronic power components.
BRIEF DESCRIPTION OF THE FIGURES
Other aspects, purposes and advantages of the invention will become clear after reading the following description with reference to the attached drawings, in which:
FIGS. 1A and 1B are diagrams of an embodiment of a polishing apparatus according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An implementation is described below that relates to the silicon face of a SiC film. It should be noted that SiC is a polar material, and thus includes two faces composed of different atoms (a silicon face and a carbon face). The thin film is, for example, obtained by a substrate fracture method (the SMART-CUT® process) such as that described in the above-cited article by A. J. Auberton-Hervé et al.
A heat treatment is first carried out on the thin film in an oxidizing atmosphere, for example, at a temperature in the range of about 1000° C. or about 1150° C. to about 1300° C. for a period in the range of from about 1 hour to about 3 hours. This annealing step in an oxidizing atmosphere can produce a surface roughness of on the order of about 2 nm rms. One example of a device for carrying out the annealing step is described in “Thermal and Dopant Processes”, Chapter 4, Advanced Semiconductor Fabrication Handbook, ICE, 1998.
The treated surface can be deoxidized by chemical etching, for example, by using 10% hydrofluoric (HF) acid. A chemical-mechanical polishing (CMP) step is then subsequently conducted, for example, by using an IC1000 pad (which is distributed by the RODEL company, having a compressibility of about 3%) and an abrasive based on colloidal silica SYTON W30 (or LuDox) type particles (pH=10.2, viscosity=2 megapascal.seconds (mPs.s), mean particle size=125 nm, containing 30% SiO 2 by weight).
FIG. 1A shows a substrate 12 inserted into a polishing head 10 . FIG. 1B shows the polishing head 10 , the substrate 12 to be polished, a plate 16 and a polishing pad 14 . A liquid abrasive is injected into the head, for example, via a side conduit 18 . Pressure 20 along with a side-to-side movement represented by an arrow 22 are applied to the head 10 to carry out polishing. Optionally, chemical cleaning using hydrofluoric acid may be used to prevent crystallization of the abrasive on the surface. This method can produce a surface with a suitable roughness that enables it to be used for good quality homoepitaxy (SiC on SiC epitaxy), and optionally also heteroepitaxy (AlN, AlGaN or GaN on SiC).
EXAMPLE
The following is an example relating to a thin film of a 4H type SiC (obtained by the SMART-CUT® method). An annealing step was carried out in an oxidizing atmosphere (for example, for 2 hours at 1150° C.), followed by surface deoxidation in 10% HF followed by polishing the surface by CMP. Polishing was carried out with the use of a rotating polishing plate onto which a polishing head had been applied, also rotating, the speed of rotation being of the order of 60 revolutions per minute (rpm) with a pressure of 0.75 bars applied to the head. The pad used was a “hard” type IC1000 pad distributed by the RODEL company, with a slurry which was a SYTON W30-type colloidal silica.
The polishing time was about 15 minutes (min) to about 30 min, and the roughness obtained after polishing was on the order of about 3 Å rms. Final cleaning carried out using deionized water with a 10% HF bath for 10 minutes.
Table I below summarizes the results obtained for thin SiC films under different conditions.
TABLE I
I
II
III
IV
V (nm)
VI
1
None
5.02
2
Ion etching + anneal
3.02
1150° C., time: 2 h
3
Ion etching + anneal
30 min/70 rpm/
UR 100/
0.583
soft pad
1150° C., time: 2 h
0.75 b
glansox
4
Anneal 1150° C.,
30 min/60 rpm/
UR 100/
1.246
soft pad
time: 2 h
0.75 b
glansox
5
Anneal 1150° C.,
1.12
time: 2 h + ion
etching
6
Anneal 1150° C.,
2.54
annealing
time: 2 h
sufficient to reduce
roughness
7
Anneal 1300° C.,
1.64
time: 1 h
8
Anneal 1150° C.,
15 min/25 rpm/
IC1000/syt
0.267
Fairly slow speed
time: 2 h
0.6 b
on
of rotation
9
Anneal 1150° C.,
30 min/60 rpm/
IC1000/syt
0.101
time: 2 h
0.75 b
on
10
Anneal 1150° C.,
15 min/60 rpm/
IC1000/syt
0.155
worn pad
time: 2 h
0.75 b
on
11
Anneal 1150° C.,
15 min/60 rpm/
IC1000/syt
0.064
new pad
time: 2 h
0.75 b
on
In the table, column I indicates the test number and column II shows the nature of the treatment carried out prior to CMP polishing. Tests 2 and 3 underwent ion etching followed by annealing at 1150° C. for two hours; for test number 5, the treatment was annealing at 1150° C. for two hours followed by ion etching. For tests 4, 6 and 8 to 10, only annealing at 1150° C. for two hours was carried out.
Column III gives the conditions for carrying out CMP polishing including the time, rotation speed, and applied pressure.
Column IV shows the nature of the pad and the abrasive mixture.
Column V shows roughness measurements over a surface area of 5 micrometers (μm)×5 μm.
Comments are shown in column VI.
Table I shows that the combination of an annealing step followed by polishing can substantially reduce the roughness of the initial film to less than 2 nm rms (see tests 3–5 and 7–11), 1.5 nm (see tests 3–5 and 8–11), 1 nm rms (tests 3 and 8–11), 0.5 nm rms (tests 8–11), or 0.1 nm rms (test 11). Thus, the invention can produce a silicon carbide film with a roughness of less than 2 nm rms, less than 1 nm rms, less than 0.5 nm rms, or less than 0.1 nm rms. Use of prior ion etching, as in test number 3, also improves the result.
The best results appear to be obtained with an IC1000 pad and with a Syton W30 abrasive solution.
Table II below shows more detailed conditions concerning test numbers 10 and 11. In particular, test number 10 was carried out using an “S107” plate while test number 11 was carried out using an “S126” plate, and Table II compares roughness values using the S126 and S107 plates.
Two types of measurements were carried out: scanning a certain surface area (column S, surface area indicated in square micrometers (μm 2 )), and point measurements (column B, surface measurements indicated in μm×μm).
The last three columns show, in angstroms: roughness as a root mean square value (rms), mean roughness (Ra), and maximum roughness (Rmax)
The values shown in Table I for tests 10 and 11 respectively correspond to those shown in the third and seventh lines of Table II (rms column).
TABLE II
Comparison of roughness using plates S126 and S107
Plate
S (μm 2 )
B μm
rms (Å)
Ra (Å)
Rmax (Å)
S107
1 μm × 1 μm
0.97
0.77
14.7
0.3 × 0.9
0.7
0.55
8.2
5 μm × 5 μm
1.55
1.21
16.1
3 × 1
1.38
1.06
12.1
S126
1 μm × 1 μm
0.37
0.28
7
0.6 × 0.7
0.34
0.27
3
5 μm × 5 μm
0.64
0.5
29.7
1.5 × 4
0.31
0.25
4.9
The results shown in these tables indicate that the method according to the invention can produce a surface that is ready for epitaxy (“epiready”) on thin SiC films, using a rapid technique, which employs steps and machines that are standard in microelectronics. The smoother the SiC surface and the lower its roughness, the better the quality of the epitaxy, which can substantially increase the yield of electronic components produced on the thin film. The surface preparation method of the invention, comprising an annealing step followed by polishing, can thus produce a good quality surface that is not rough and is smooth.
The example of a polytype 4H SiC substrate has been used herein, but it should be noted that the invention is also preferred for us with other SiC substrates, such as a polytype 6H substrate or to a 3C SiC substrate.
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The invention concerns a method of preparing the surface of a semiconductor wafer intended for microelectronics and/or optoelectronics applications. In particular, a method of preparing a SiC surface of a semiconductor wafer to make it epiready is described. The technique includes annealing the wafer in an oxidizing atmosphere, and polishing a surface of the wafer with an abrasive based on particles of colloidal silica to make the SiC wafer surface suitable for homoepitaxy or heteroepitaxy.
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This is a continuation of Ser. No. 317,218, filed 11-2-81 now U.S. Pat. No. 4,416,407 issued 12-15-83.
BACKGROUND OF THE INVENTION
This invention relates to the dispensing of fasteners, particularly fasteners which are included in an assemblage from which individual fasteners are dispensed as desired.
One common form of fastener is of the type disclosed in U.S. Pat. Nos. 3,103,666; 3,444,597; 3,733,657; and 4,039,078. The individual fasteners in assemblages of the kind disclosed in the foregoing patents include opposite end members that are interconnected by a transverse segment commonly designated a "filament". Generally one of the end members is a "cross bar" in the form of a short cylindrical element disposed at a right angle to the filament and proportioned to be dispensed through the bore of a slotted hollow needle. In the course of dispensing a fastener, its cross bar is moved through the bore with the filament extending through the slot of the needle. The member opposite the cross bar is in accordance with the intended function of the fastener. One common form of opposite end member is a transverse enlargement commonly known as a "head" or "paddle". It is used, for example in supporting an information bearing tag which is attached to an item of merchandise such as a garment by the dispensing device.
The dispensers for such fasteners are generally of the kind disclosed in U.S. Pat. Nos. 3,103,666; 3,470,834; Re. 29,310; 3,893,612; 3,875,648; and 4,111,347.
The expulsion mechanism of the foregoing dispensing devices generally includes an elongated slide as shown in U.S. Pat. Nos. 3,103,666 and Re. 29,310 in order to achieve simultaneous operation of the feed mechanism and the plunger by which individual fasteners are expelled from the device.
An alternative construction is of the type shown in U.S. Pat. Nos. 3,650,451; 3,650,452; and 3,924,788. This construction requires that the housing for the dispensing apparatus allow for the pivotting of a lever which acts upon the feed and dispensing mechanisms. The result is an increase in bulk over and above what would otherwise be required.
In addition it is desirable to provide a release mechanism to permit clearing of the device or release of any occasional jams that may occur. One type of release mechanism operates only when the trigger is depressed. This is cumbersome and inoperable in many situations. Another type of release mechanism disables both the drive and feed mechanisms of the gun. This adds complexity to the mechanism. It is additionally undesirable since operation of the drive mechanism is often useful in clearing a jam. Thus if the drive is interrupted during clearance, the clearance procedure becomes more difficult to accomplish. Still another type of release mechanism disables the feed mechanism at a portion remote from the pawl. As a result the clearance procedure must be undertaken with care.
Another characteristic of the ordinary dispensing device is that the feed takes place using a pawl which engages, for example, sprocket teeth of a feed wheel. In the ordinary construction there is a significant amount of wear that takes place in the pawl over the course of time. The result is that the ordinary attacher gun has a limited life. It is not possible for the customer to repair the worn pawl and the dispensing device must therefore be returned to a service center for repair.
Accordingly, it is an object of the invention to facilitate the dispensing of fasteners. A related object is to facilitate the dispensing of individual fasteners from an assemblage in which each individual fastener includes end members that are joined by a cross member commonly referred to as a filament.
A further object of the invention is to simplify the control lever that is used in actuating both the feed and expulsion mechanisms simultaneously. A related object is to achieve compactness in the design of devices for dispensing fasteners by reducing slide length and eliminating the customary pivoted lever of the prior art.
Still another object of the invention is to facilitate the release of assemblages that have been inserted into dispensing devices, as well as the clearance of jams. A related object is to achieve release and clearance without disabling the drive function of the device.
Another object of the invention is to prolong the life of the device by reducing the incidence of wear that commonly takes place between a feed pawl and a drive sprocket. A related object is to achieve increased wear with a simplified pawl.
SUMMARY OF THE INVENTION
In accomplishing the foregoing and related objects the invention provides a dispenser which receives and feeds an assemblage of fasteners and expells individual ones of the fasteners. The expulsion and feed of the fasteners is controlled by a lever which has a tip that moves along a linear path.
In accordance with one aspect of the invention the control lever is operated by a trigger that is pivotally connected to the device and includes a fixed projection which moves along a slot of the lever.
In accordance with another aspect of the invention a link is pivotally connected to the control lever between its end positions and pivotally attached to the device. The link is desirably spring biased at its pivot position by a support rod that extends from the pivot position to a trigger and enters an apertured portion of the trigger, with the support rod surrounded by a coil spring.
In accordance with a further aspect of the invention, expulsion of the fasteners is achieved by a plunger pivotally secured to the lever, while feeding takes place using a slide containing spaced-apart projections on opposite sides of the lever, which engages the projections during the feeding operation.
In accordance with yet another aspect of the invention the dispenser includes a linkage with two separate pivot positions for controlling the feed of fasteners. Feeding takes place with a feed wheel having peripheral indentations for engaging the fasteners and a pawl that is pivotally connected to the double pivot linkage. This construction reduces the incident wear in the feed mechanism which advantageously includes a slide pivotally connected to the linkage.
In accordance with a yet further aspect of the invention, feeding takes place by a pawl in the form of a planar member with a transverse tooth that engages a feed wheel. The pawl is pivotally connected to a linkage which is further pivotally connected to a slide. The latter includes spaced-apart projections that are successively engaged during the feeding of fasteners by engagement of a trigger operated lever. The projections are desirably in the form of cylindrical posts of unequal size to permit final adjustment of the stroke in the manufacture of the device.
In accordance with still another aspect of the invention, the dispenser for fasteners includes a feed pawl with an antibackup member and a further member for simultaneously disengaging the feed pawl and the antibackup. The disengagement member desirably engages a planar portion of the feed pawl. The disengagement desirably moves transversely with respect to the direction of feed of fasteners and includes a shoulder that disengages the antibackup member.
In accordance with yet another aspect, the disengagement member releases the feed pawl from the feeding mechanism without affecting the drive portion of the device.
In accordance with still another aspect of the invention, the dispenser is provided with a frontal configuration that facilitates the use of the device in the labeling of merchandise. This is accomplished in part by the provision of a flatenned nose with a lower concavely curved lip that accommodates the index finger of the operator and by the position of the operating trigger closer to the nose than in other devices. In addition a curved exit chute is provided for the runners that are associated with the fasteners to direct the exiting runners away from the fingers of the operator and limit the inconvenience and interference associated with runner expulsion in other dispensers.
DESCRIPTION OF THE DRAWINGS
Other aspects of the invention will become apparent after considering several illustrative embodiments taken in conjunction with the drawings in which:
FIG. 1 is a perspective view of a device for dispensing fasteners in accordance with the invention;
FIG. 2A is a cross-sectional view of the interior of the dispenser of FIG. 1;
FIG. 2B is a sectional view of the dispenser of FIGURE along the entry channel for the fasteners in being dispensed;
FIG. 2C is a sectional view of a disengagement mechanism in accordance with the invention;
FIG. 2D is a top sectional view of the dispenser of FIG. 1 showing a fastener in position for being dispensed;
FIG. 2E is a sectional view of the rear portion of the dispenser of FIG. 1 including its handle;
FIG. 3A is a sectional view showing a pivoted feed linkage mechanism in accordance with the invention;
FIG. 3B is a sectional view showing the dispenser of FIG. 1 in the course of being operated to expel a fastener;
FIG. 3C is a phantom view illustrating the operation of the feed mechanism for the dispenser of FIGS. 1, 2A and 3A;
FIG. 3D is a sectional view of the handle portion of the dispenser of FIG. 3B.
DETAILED DESCRIPTION
With reference to the drawings, FIG. 1 depicts a dispenser 10 for the controlled pistol grip expulsion of fasteners 20. A user's hand, indicated in phantom, grips the dispenser 10 in the fashion of a pistol, with the result that the dispenser 10 can be regarded as a pistol grip dispenser.
The particular dispenser 10 of FIG. 1 expels successive fasteners from a clip 20 along the bore of a slotted hollow needle 30. As illustrated below, individual fasteners are dispensed by being fed successively into alignment with the bore of the needle 30. Each fastener is then expelled through the bore with its filament 22 extending outwardly through the slot 31 of the needle 30.
In an illustrative use, a merchandising tag (not shown) is positioned on the needle 30 against the front end 12 of the dispenser 10. The needle is then inserted into an item of merchandise to be tagged. When the trigger 13 is operated by being depressed into the pistol grip housing 14, a cross bar 21 is moved along the bore of the needle 30 until it is expelled on the reverse side of the garment. When the dispenser 10 is withdrawn, the cross bar 21 is on the opposite side of the garment and the filament 22 extends through the garment to the tag which rests against a head 23.
In order to promote the utility of the dispenser 10, the invention provides, among other things, a plunger lever with a linear operated tip, as described below, by contrast with the pivotted levers of the prior art which require an enlarged area in the housing for lever swing during each dispensing operation. As a result of the linear path provided for the tip of the lever operating the plunger, the dispenser 10 is of limited height. This promotes the usability of the product by permitting better visibility in tagging operation.
In addition, the dispenser 10 permits ready clearance of the passageway into which the clip of fasteners 20 is inserted. Such clearance can be helpful in the event of a jam in the needle or elsewhere in the dispenser. The invention also provides a limited possibility of jamming by the use of a double pivot for controlling the feed mechanism that is used to advance the individual fasteners into position for being dispensed.
The features provided by the invention are illustrated in the cross-sectional view of FIG. 2A. A plunger 15 is reciprocated in the upper portion of the housing 10 by a pivotally connected control lever 16. The latter is operated by the trigger 13 which contains a post 13p that confines the motion of the lever 16 with respect to a slot 16s. Because the tip of the lever 16 moves linearly, it can be pivotally connected at position 16p to the plunger mount 15m.
The desired linear motion of the pivot 16p is achieved by the use of a link 17 that is in turn pivotally connected at a position 17p-1 intermediate the ends of the lever 16. The opposite end of the link 17 is pivotally fixed to the handle 14 at a position 14p. Desired biasing is provided by a spring 18s which is compressed as a supporting post 18 is depressed into an aperture 13a at a pivot position 13t of the trigger 13.
In addition to reciprocating operation of the plunger 15, the lever 16 also serves to control the feed mechanism 19. The latter consists of a slide 19s with spaced-apart posts 19p-1 and 19p-2 between which the upper portion of the lever 16 is movable during reciprocation of the plunger 15.
The forward portion of the slide 19 is pivotally connected to a pawl 19w by a link 19k. The pawl 19w contains a tooth 19t which acts upon a feed wheel 19f during reciprocation of the slide 19 by virtue of the linear motion of the pivot point 16p associated with the lever 16. The feed wheel 19f is restrained by a lever 19r which is maintained in position against the feed wheel 19f by a torsional spring 19c. The latter has one extended arm which bears against the lever 19r and another which bears against the frontal inside surface of the housing 10. The pawl 19w is resiliently held against the face of the feed wheel 19f by a curve biasing washer 19b. This washer provides sufficient resiliency so that the pawl tooth 19t can move the feed wheel and also allow pawl disengagement as explained below.
When the feed slide 19 is moved forwardly, by engagement of the lever 16 with the post 19p-1, the pawl is moved in a clockwise direction of the arrow B as illustrated in FIG. 3B, with the tooth 19t clearing the teeth of the feed wheel 19f because the latter is prevented from moving by the antibackup lever 19r. When the lever 12 is released, the sequence of events is as indicated in FIG. 3C, with the tooth 19t of the pawl 19w engaging a tooth of the feed wheel 19f and moving it in the counterclockwise direction indicated by the arrow C in FIG. 3C.
In the event that a jam occurs, for example during the successive feeding of fasteners of the clip 20 shown in FIG. 2B, a release slide 23 is operated, having the construction illustrated in FIG. 2C. The release slide 23, when depressed along the direction indicated by the arrow D disengages the antibackup lever 19r from the feed wheel 19f and simultaneously disengages the pawl 19w from the feed wheel 19f. As noted above the washer 19b returns the pawl to operating position when the slide 23 is released.
As indicated in FIG. 2C, before the translation force is applied to the release slide 23 a narrow tip 23f is in contact with a side face of the pawl 19w and a ramp 23r is in position for pivotting the antibackup lever 19r downwardly as indicated by the phantom arrow E in FIG. 2C.
A fastener in position for being dispensed is shown in FIG. 2D before contact is made with its cross bar 21 by the tip of the plunger 15.
In the cross-sectional view of FIG. 2E the various components of the lever mechanism in relation to the handle 13 is shown. In particular the trigger 13 is fixed pivotally at pivot points 13-1 and 13-2 and includes a platform 12p through which the support post 18 is able to be depressed when the trigger 12 is squeezed into the housing 13.
A specific view showing the relationship of the link 19k to the pawl 19w and the slide 19 at pivot points 19-1 and 19-2 is shown in FIG. 3A. It is the double pivot connection of FIG. 3A that permits a dispenser in accordance with the invention to provide extended life for the pawl 19w and simultaneously limit the likelihood that a jam will occur or a malfunction will occur by virtue of improper operation of the feed slide 19.
FIG. 3B shows the dispenser 10 with the trigger 13 fully depressed into the handle 14. In this position the lever 16 has its tip at the pivot 16p of the mounting block 15m and the plunger 15 is in its most forward position with the tip of the plunger fully forward in the needle 30, the fastener 20 of FIG. 2D having been fully expelled. In this position the lever 16 rests against the forward post 19p-1 of the feed mechanism 19 with the pawl 19w in its lowermost position by virtue of the forward motion of the link 19k.
When the trigger 13 is released, the result, as noted above is in accord with FIG. 3C. The link 19k moves upwardly at the same time that the feed mechanism 19 moves rearwardly. The upward motion of the link produces a pivotting action of the pawl 19w, and the tooth 19t of the pawl 19w engages a feed notch of the feed wheel 19f and rotates it in a counterclockwise direction by one notch position to advance the fasteners 20 of FIG. 3B so that the lowermost fastener is in line with the bore of the needle 30.
Referring again to FIG. 3B it is seen that with the trigger 13 fully depressed the post 13p occupies the uppermost position of the slot 16s in the lever 16. It is also seen that the supporting post 18 is fully depressed through the aperture 13a and the spring 18s is fully compressed. These matters are further illustrated in the cross-sectional view of FIG. 3D.
It will be noted that the frontal portion of the dispenser 10 is specifically configured to facilitate use of the device in the tagging of merchandise. The front portion 12f below the needle 30 has a surface with a curvature that forms an angle of less than 15° with a line of tangency at the needle mounting position. As a result there is a surface at the front of the dispenser below the needle that is particularly suitable for the positioning and retention of a tag on the needle during the tagging operation. It is customary for users to place a tag that is to be applied to merchandise on the needle and hold that tag during the tagging operation. Prior art dispensers made it relatively cumbersome and inconvenient to maintain the tag in position at the front of the gun. As a result during use of the gun the tags commonly fell from the needle with an attendant disruption and delay in the tagging operation. The frontal surface provided by the invention permits the operator to position the tag on the needle in the customary way and hold the balance of the tag on the frontal surface with the forefinger. This has significantly increased the efficiency with which this type of dispenser can be used. Moreover the front is provided with a chin point 12c which extends to the trigger 13 by an arc 12a accommodates the middle finger of the user and further promotes facility in the use of the dispenser. Additional advantage is also achieved by location of the pivot point 13-1 and 13-2 at a position which is below the axis of the feed wheel 19f and along the tangency to the notch position of the feed wheel at the axis for the plunger 15. It is important in this context that the handle 13 have a tangent from the pivot position 13-1 to its central gripping surface no greater than 30°. The front profile of the trigger essentially forms a right angle with respect to the axis of feed for the device. This angle can vary between approximately 85° and 95°.
While various aspects of the invention have been set forth by the drawings and the specification, it is to be understood that the foregoing detailed description is for illustration only and that various changes in parts, as well as the substitution of equivalent constituents for those shown and described, may be made without departing from the spirit and scope of the invention as set forth in the appended claims.
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Dispensing of fasteners by a device which receives an assemblage of the fasteners and is able to expel them individually through, for example, a slotted hollow needle. The dispensed fasteners can be used generally in the attachment of items to one another and, in particular, for the labeling of textile goods and the like with information bearing tags. The device includes a trigger operated feed mechanism and a simultaneously operable expulsion mechanism. Both mechanisms are controlled by the tip of a lever which is proportioned and disposed in the device to execute linear motion. The feed mechanism is disengageable from the remainder of the device to permit clearance of the inserted assemblage or the removal of jams. The feed mechanism additionally is operated by a planar pawl having a tooth that extends into contact with indentations on the periphery of a feed wheel.
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BACKGROUND
The instant invention is in the field of sensors and more specifically the instant invention is in the field of wireless sensors employing harmonic electromagnetic transponders.
A harmonic electromagnetic transponder receives electromagnetic radiation at a fundamental frequency and emits electromagnetic radiation at a harmonic of the fundamental frequency. The harmonic of the fundamental frequency is usually the first harmonic (or twice the fundamental frequency). A passive harmonic electromagnetic transponder requires no power source (other than the power of the incoming electromagnetic radiation) for its operation. An active harmonic electromagnetic transponder requires a power source for its operation. As discussed by Maas, The RF and Microwave Circuit Design Cookbook, 1998, Chapter 2 , a common passive harmonic electromagnetic transponder comprises a receiving antenna tuned to resonate at the frequency of the incoming electromagnetic radiation, an emitting antenna tuned to resonate at twice the frequency of the incoming electromagnetic radiation, the receiving antenna being electrically connected to the emitting antenna by a Schottky diode. The electromagnetic radiation is usually in the radio wave or “radar” portion of the electromagnetic spectrum.
U.S. Pat. No. 3,781,879 described a harmonic radar detecting and ranging system for automotive vehicles wherein the receiving and emitting antennas are arranged for orthogonal polarization of the received and emitted electromagnetic radiation. U.S. Pat. No. 4,001,822 described a harmonic radar electronic license plate for motor vehicles incorporating a single antenna for receiving electromagnetic radiation and for emitting a unique pulse coded electromagnetic radiation at a harmonic frequency of the received electromagnetic radiation. U.S. Pat. No. 4,063,229 described a harmonic radar anti-shoplifting system incorporating a fusible link or other means in the electronic circuit of a tag to be incorporated into goods for sale so that the tag could be deactivated at the store's checkout counter before the goods passed the radar transmitter/receiver located at the exit(s) of the store.
Steel pipes, vessels and structural members (such as I-beams) are commonly used in industrial installations and are frequently covered with insulation. Inadvertent latent corrosion of such pipes, vessels or structural members can occur under the insulation which corrosion can be expensive to repair and can even end the useful life of the pipe, vessel or structural member. Therefore, it is common practice to periodically remove a portion of the insulation to inspect for such corrosion. Such inspections are expensive and invasive of the integrity of the insulation. It would be an advance in the art of such inspections if a non-invasive remote wireless inspection means were devised.
SUMMARY OF THE INVENTION
The instant invention provides, for example, a non-invasive remote wireless means to detect a condition that may lead to inadvertent latent corrosion of an insulated steel pipe, vessel or structural member. In its broad scope, the instant invention provides a method for detecting a latent environmental effect or a latent structural change at a known remote location. The method of the instant invention comprises three steps. The first step is to use a harmonic electromagnetic transponder at the known remote concealed location of the latent environmental effect or the latent structural change, the harmonic electromagnetic transponder having a reactive portion which reacts to the latent environmental effect or latent structural change to modify the harmonic emission of the transponder. The second step is to remotely interrogate the transponder by directing electromagnetic radiation at the transponder. The third step is to use the harmonic emission of the transponder to remotely determine the latent environmental effect or latent structural change. When the latent environmental effect is, for example, moisture that may lead to corrosion of an insulated carbon steel pipe, vessel or structural member, then the reactive portion of the transponder can be an electrical conductor, such as steel wire, that corrodes when exposed to moisture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a harmonic electromagnetic transponder that can be used in the method of the instant invention, the transponder incorporating a corrodible link in the transmission line between a first patch antenna and resonator tuned to a fundamental electromagnetic frequency, the first resonator in electrical communication with a second resonator, patch antenna and transmission line tuned to the first harmonic of the fundamental electromagnetic frequency by way of a Schottky diode;
FIG. 2 is a block diagram of a transmitter that can be used in the method of the instant invention;
FIG. 3 is a block diagram of a receiver that can be used in the method of the instant invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 , therein is shown a front view of a harmonic electromagnetic transponder 10 that can be used in the method of the instant invention. The transponder 10 is based on a fifteen by thirty centimeter panel of 1.52 millimeter thick glass fiber reinforced polymer substrate 11 having a normal dielectric constant of 3.5. The back side of the substrate 11 is coated with a 0.04 millimeter thick layer of copper ground plane, not shown. An 87.25 millimeter by 108.2 millimeter, 0.04 millimeter thick copper receiving patch antenna 12 is formed on the front of the substrate 11 . A 49 millimeter by 4 millimeter, 0.04 millimeter thick copper first resonator 13 is also formed on the front of the substrate 11 . The distal end of the first resonator 13 is electrically connected to the copper ground plane by soldered wire 14 . A 45.8 millimeter by 4 millimeter, 0.04 millimeter thick copper fifty ohm impedance first transmission line 15 is also formed on the front of the substrate 11 in electrical communication at one end with the receiving patch antenna 12 and at the other end thereof with the first resonator 13 . A portion of the first transmission line 15 is comprised of a short length of carbon steel wire 16 .
Referring still to FIG. 1 , a 44 millimeter by 53.75 millimeter, 0.04 millimeter thick copper emitting patch antenna 17 is formed on the front of the substrate 11 . A 49 millimeter by 4 millimeter, 0.04 millimeter thick copper second resonator 18 is formed on the front of the substrate 11 . A 32.2 millimeter by 4 millimeter, 0.04 millimeter thick copper fifty ohm impedance second transmission line 19 is also formed on the front of the substrate 11 in electrical communication at one end thereof with the emitting patch antenna 17 and at the other end thereof with the second resonator 18 . The central ends of the first resonator 13 and the second resonator 18 are in electrical communication by way of a Schottky diode 20 .
Referring still to FIG. 1 and the transponder 10 , it will be understood by a person of ordinary skill in the art that the exact dimensions of the antenna patches and resonators of a harmonic radar transponder will usually require adjustment to tune the system, as described, for example, by Chang, RF And Microwave Circuit And Component Design For Wireless Systems, 2002 , Chapter 12.9 , MICROSTRIP PATCH ANTENNAS. A general discussion of the design of passive harmonic transponders is found, for example, by Maas, The RF and Microwave Circuit Design Cookbook, 1998, Chapter 4 , SINGLE-DIODE RESISTIVE FREQUENCY DOUBLER. The transponder 10 is specifically designed to receive 917 MHz and emit 1.834 GHz. Copper coated dielectric sheets are commercially available, for example, from Taconic Advanced Dielectric Division, Petersburg, N.Y. The transponder 10 is specifically designed to be placed under the thermal insulation of an insulated carbon steel tank.
Referring now to FIG. 2 , therein is shown a radar transmitter system 30 for transmitting electromagnetic radiation having a frequency of 917 MHz. The transmitter system 30 includes an oscillator 31 (Miteq, Inc., Hauppauge, N.Y., Model BCO-20-917-12) connected to a radio frequency amplifier 32 , connected to a low pass filter 33 , connected to a notch filter 34 and then to a Yagi antenna 35 .
Referring now to FIG. 3 , therein is shown a radar receiving system 40 for receiving electromagnetic radiation having a frequency of 1.834 GHz. The receiver system 40 includes an Yagi antenna 41 connected to a high pass filter 42 (1.58 GHz) connected to a notch filter 43 (917 MHz), connected to low noise amplifier 44 , connected to low pass filter 45 (2.4 GHz) which is connected to a first mixer 46 . An oscillator 47 (Miteq, Inc., Model BCO-20-1666-12, 1.666 GHz) is connected to the mixer 46 to produce a first intermediate frequency of 168 MHz fed to low pass filter 48 (180 MHz), to amplifier 49 (30 dB Gain), and then to fifty ohm attenuator 51 . The output from the attenuator 51 is fed to a helical resonator band pass filter 52 (167 MHz) and then to a second mixer 53 . The mixer 53 is connected to a low pass filter 56 (180 MHz), amplifier 55 (MMIC), amplifier 55 a (High Impedance Buffer Amplifier) and crystal oscillator 54 (146.6 MHz) to produce a second intermediate frequency of 10.7 MHz which is fed to low pass filter 57 (30 MHz), to amplifier 58 (20 dB Gain), to crystal filter 59 (21.4 MHz), to low band pass filter 59 a (30 MHz) and then to log amplifier 60 . The output of the log amplifier 60 is fed to an operational amplifier 61 (utilized as a DC gain block) to a time averaging integration amplifier system 62 , to a DC offset operational amplifier 63 and then to signal meter 64 . The output of the operational amplifier 63 is fed into a buffer amplifier 65 where the logarithmic signal strength reading is fed outside of the radar system.
It should be understood that the apparatus of FIGS. 1–3 is but one specific example of apparatus that can be used in the method of the instant invention. For example, the carbon steel wire 16 of FIG. 1 (or other corrodible metal) can alternatively be positioned anywhere else in the circuit of the transponder, for example as a part of the second transmission line, the first resonator, the second resonator or the leads to the Schottky diode. Any non-linear element can be used in place of the Schottky diode even though a Schottky diode is highly preferred.
The term “latent environmental effect” here and in the claims includes, without limitation thereto, temperature, humidity, salts, acids, bases, ions, corrosive fumes and chemical vapors concealed from ordinary view such as moisture under insulation or chloride ions in a steel reinforced concrete bridge deck. The term “latent structural change” here and in the claims includes, without limitation thereto, a change of position, acceleration, strain or vibration of a structure concealed from ordinary view. The term “reactive portion” includes, without limitation thereto, a corrodible conductor, a thermostatic switch, a resistor or capacitor whose resistance or capacitance varies as a function of temperature, humidity, exposure to a chemical, acceleration, vibration, or strain.
The term “harmonic electromagnetic transponder” means an electronic device having a receiving antenna or an element that acts as a receiving antenna in electrical communication, directly or indirectly, with an emitting antenna or an element that acts as an emitting antenna by way of a non-linear element such as the PN junction of a diode or a transistor. Thus, almost any modern electronic device (such as a transistor radio or a computer) will act as a harmonic electromagnetic transponder. However, preferably the harmonic electromagnetic transponder used in the instant invention is designed as such.
Preferably, the harmonic electromagnetic transponder used in the instant invention is a passive harmonic electromagnetic transponder. However, an active harmonic electromagnetic transponder can be used and may be preferred when it is desired to digitally code the harmonic emission of the transponder. Such digital coding is known for other applications, see, for example, U.S. Pat. No. 4,001,822.
EXAMPLE 1
The transponder 10 of FIG. 1 is positioned under the thermal insulation of a carbon steel vessel located in a tank farm of an industrial facility. The antennas 35 and 41 of the transmitter 30 and the receiver 40 of FIGS. 2 and 3 respectively are pointed at the tank from a distance of fifty feet. The transmitter 30 is turned on to direct electromagnetic radiation at the transponder 10 . The signal indicated by the meter 64 of the receiver 40 is twelve decibels.
Every month for the next sixty nine months, the antennas 35 and 41 of the transmitter 30 and the receiver 40 of FIGS. 2 and 3 respectively are pointed at the tank from a distance of fifty feet. The transmitter 30 is turned on to direct electromagnetic radiation at the transponder 10 . The signal indicated by the meter 64 of the receiver 40 is twelve decibels each time the transponder 10 is interrogated. However, the interrogation at seventy months indicates a response of only two decibels.
The insulation is removed from the tank at the location of the transponder 10 and it is noticed that the insulation is wet, the carbon steel wire 16 of the transponder 10 has corroded away apparently destroying the function of the first transmission line 15 . However, the tank has suffered only superficial latent corrosion under the insulation. Investigation reveals that the wet insulation is caused by weathering of a seam in the insulation near the top of the tank. The insulation is removed from the tank and replaced with new insulation.
EXAMPLE 2
A transponder like the transponder 10 of FIG. 1 (but not having the carbon steel wire 16 in the transmission line 15 and instead having a carbon steel wire soldered at each end thereof to and bridging the first resonator 13 and the second resonator 18 ) is positioned under the thermal insulation of a carbon steel tank located in a tank farm of an industrial facility. The antennas 35 and 41 of the transmitter 30 and the receiver 40 of FIGS. 2 and 3 respectively are pointed at the tank from a distance of sixty feet. The transmitter 30 is turned on to direct electromagnetic radiation at the transponder 10 . The signal indicated by the meter 64 of the receiver 40 is two decibels.
Every month for the next eighty eight months, the antennas 35 and 41 of the transmitter 30 and the receiver 40 of FIGS. 2 and 3 respectively are pointed at the tank from a distance of fifty feet. The transmitter 30 is turned on to direct electromagnetic radiation at the transponder 10 . The signal indicated by the meter 64 of the receiver 40 is two decibels each time the transponder 10 is interrogated. However, the interrogation at eighty nine months indicates a response of ten decibels.
The insulation is removed from the tank at the location of the transponder and it is noticed that the insulation is wet, the carbon steel wire of the transponder has corroded away apparently enabling the transponder to function. However, the tank has suffered only superficial latent corrosion under the insulation caused by inadvertent tearing the insulation near the top of the tank when an adjacent pipeline was painted. The insulation is removed from the tank and replaced with new insulation.
EXAMPLE 3
A reference transponder like the transponder 10 of FIG. 1 is produced but having no carbon steel wire in the first transmission line 15 . The reference transponder is positioned under the thermal insulation near one end of a carbon steel tank of an over-the-road tank trailer. A transponder like the transponder 10 of FIG. 1 is produced (but having no carbon steel wire in the first transmission line 15 but having a thermostatic switch bridging the first resonator 13 and the second resonator 18 ) and positioned under the thermal insulation of the tank trailer near the other end of the tank trailer. The tank trailer is used to transport molten sulfur from a sulfur recovery installation to a sulfuric acid production plant. The molten sulfur in the tank trailer needs to be at least one hundred and forty degrees Celsius when the tank trailer leaves the sulfur recovery installation so that the sulfur is still molten by the time the tank trailer arrives at the sulfuric acid plant. The thermostatic switch closes at one hundred and fifty degrees Celsius and opens at one hundred and forty degrees Celsius.
The transmitter 30 of FIG. 2 and the receiver 40 of FIG. 3 are installed at the gate of the sulfur recovery installation. The output of the amplifier 63 is monitored each time the tank trailer passes out of the sulfur recovery installation on its way to the sulfuric acid plant. A normal response pattern is a response of about forty to fifty decibels as the reference transponder passes the receiver 40 and a response of about three to four decibels as the other transponder passes the receiver 40 . However, on one occasion the response pattern is a response of forty three decibels as the reference transponder passes the receiver 40 and a response of forty decibels the other transponder passes the receiver 40 . The tank trailer is checked and it is discovered that the temperature of the molten sulfur is only one hundred and thirty degrees. The tank trailer emptied and refilled with sulfur at a temperature of one hundred and fifty degrees Celsius. The response pattern is then a response of forty six decibels as the reference transponder passes the receiver 40 and a response of three decibels the other transponder passes the receiver 40 .
EXAMPLE 4
A transponder like the transponder 10 of FIG. 1 (but not having the carbon steel wire 16 in the transmission line 15 and instead being bisected on a line perpendicular and through the transmission line 15 ) is positioned under the fire resistant thermal insulation of a carbon steel building girder with the two parts of the transponder in close association with each other but separately attached to the girder, the location of the bisection line of the transponder being at a location of maximum stress of the girder. The antennas 35 and 41 of the transmitter 30 and the receiver 40 of FIGS. 2 and 3 respectively are pointed at the girder from a distance of five feet. The transmitter 30 is turned on to direct electromagnetic radiation at the transponder 10 . The signal indicated by the meter 64 of the receiver 40 is one hundred decibels.
Every month for the next one hundred and seventeen months, the antennas 35 and 41 of the transmitter 30 and the receiver 40 of FIGS. 2 and 3 respectively are pointed at the transponder from a distance of five feet. The transmitter 30 is turned on to direct electromagnetic radiation at the transponder 10 . The signal indicated by the meter 64 of the receiver 40 is one hundred decibels each time the transponder 10 is interrogated. However, the interrogation at one hundred and eighteen months indicates a response of only ten decibels.
The insulation is removed from the girder at the location of the transponder and it is noticed that the girder is cracked and that the two parts of the transponder have separated and prevented the transponder from functioning in its normal way. The girder is repaired by welding the crack and by welding reinforcing plates to the girder at a location of maximum stress of the girder.
EXAMPLE 5
A transponder like the transponder 10 of FIG. 1 (but not having the carbon steel wire 16 in the transmission line 15 and instead having a thermistor soldered at each end thereof to and bridging the first resonator 13 and the second resonator 18 ) is positioned under the thermal insulation of a carbon steel tank located in a tank farm of an industrial facility. The antennas 35 and 41 of the transmitter 30 and the receiver 40 of FIGS. 2 and 3 respectively are pointed at the tank from a distance of sixty feet. The transmitter 30 is turned on to direct electromagnetic radiation at the transponder 10 . The signal indicated by the meter 64 of the receiver 40 is a function of the temperature of the thermistor.
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A method for detecting a latent environmental effect (such as a corrosive environment under insulation) or a latent structural change (such as a crack in a concealed structural member) at a known remote concealed location. The method of the instant invention includes three steps. The first step is to use a harmonic electromagnetic transponder at the known remote concealed location of the latent environmental effect or the latent structural change, the harmonic electromagnetic transponder having a reactive portion which reacts to the latent environmental effect or latent structural change to modify the harmonic emission of the transponder. The second step is to remotely interrogate the transponder by directing electromagnetic radiation at the transponder. The third step is to use the harmonic emission of the transponder to remotely determine the latent environmental effect or the latent structural change.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hearing aids as well as methods for the operation of hearing aids of the type having a microphone system for picking up an acoustic input signal and for emission of a microphone output signal, a signal processing unit, and an output transducer for emission of an output signal.
2. Description of the Prior Art
Modern hearing aids use devices for classification of hearing situations. The transmission parameters of the hearing aid are automatically varied depending on the hearing situation. In this case, the classification may, inter alia, influence the method of operation of the interference noise suppression algorithms, and of the microphone system. Thus, for example, depending on the identified hearing situation, a choice is made (by discrete switching or by continuous overlaying) between an omnidirectional characteristic (zero directional characteristic) and significant directionality of the microphone system (first or higher order directional characteristic). The directional characteristic is produced by using gradient microphones or by electrically connecting a number of omnidirectional microphones to one another. Microphone systems such as these have a frequency-dependent transmission response, which is characterized by a considerable fall at low frequencies. The noise behavior of the microphones, on the other hand, is not dependent on the frequency, and is slightly amplified in comparison to an omnidirectional microphone. In order to achieve a natural tonal impression, the high-pass frequency response of the microphone system must be compensated for by amplification of the low frequencies. In the process, the noise that is present in the low frequency range is likewise amplified and, in some circumstances, is significantly audible in a disturbing manner, while quiet sounds are masked by the noise.
German OS 101 14 101 discloses a method for processing an input signal in a signal-processing unit in a hearing aid. One embodiment of the known hearing aid has two microphones, with a delay element being connected to one microphone, the delay of which is set as a function of the result of a modulation analysis, in order to improve the signal processing and to reduce the interference noise.
PCT Application 00/76268 discloses a hearing aid having a signal processing unit and at least two microphones, which can be connected to one another in order to form directional microphone systems of different order, in which case the directional microphone systems may themselves be connected to one another with a weighting which is dependent on the frequency of the microphone signals emitted from the microphones. The cut-off frequency between adjacent frequency bands in which a different weighting is provided for the microphone signals can be set as a function of the result of a signal analysis.
European Application 0 942 627 discloses a hearing aid having a directional microphone system with a signal processing device, an earpiece and a number of microphones, whose output signals can be connected to one another via delay devices and the signal processing device, with different weightings, in order to produce an individual directional microphone characteristic. The preferred reception direction (main direction) for the directional microphone system can be set individually to match an existing hearing situation.
U.S. Pat. No. 5,524,056 discloses a hearing aid having an omnidirectional microphone and having a first or higher order directional microphone. The low signal frequency range in the microphone signal from the directional microphone is amplified, and is matched to the microphone signal from the omnidirectional microphone. Both the microphone signal from the omnidirectional microphone and the microphone signal from the directional microphone are supplied to a switching unit. When the switching unit is in a first switch position, the omnidirectional microphone is connected to a hearing aid amplifier, and when the switching unit is in a second switch position, the directional microphone is connected to a hearing aid amplifier. The switching unit can switch automatically as a function of the signal level of a microphone signal.
The known hearing aids with a directional microphone system have the disadvantage that, in certain hearing situations, either the directionality of the microphone system is not optimally used, or a high degree of directionality leads to a clearly audible degradation in the tonal quality. In particular, when the level of the acoustic input signal is low, the signal-to-noise ratio becomes worse, and a hearing aid wearer perceives this in the form of disturbing microphone noise in a quiet environment.
SUMMARY OF THE INVENTION
An object of the present invention is to improve the tonal quality of a hearing aid having a directional microphone system.
This object is achieved by a hearing aid according to the invention having a microphone system with at least two microphones, in order to make it possible to produce zero and first order directional characteristics. However, more than two microphones are preferably used, so that it is also possible to produce second and higher order directional characteristics. Furthermore, the hearing aid has a signal-processing unit for processing and frequency-dependent amplification of the microphone signal that is produced by the microphone system. The signals are normally emitted in the form of an acoustic output signal by means of an earpiece. However, other output transducers are also known, for example output transducers that produce vibration.
For the purposes of the invention, a zero order directional characteristic is an omnidirectional directional characteristic that originates, for example, from a single omnidirectional microphone, which is not connected to any other microphones. A microphone unit having a first order directional characteristic (first order directional microphone) may, for example, be produced by means of a single gradient microphone, or by electrically connecting two omnidirectional microphones. First order directional microphones can be used to achieve a theoretically achievable maximum directivity index (DI) value of 6 dB (hyperkidney). In practice, DI values of 4–4.5 dB are obtained on the KEMAR (a standard research dummy) with the microphones positioned optimally and with the best matching of the signals that are produced by the microphones. Second and higher order directional microphones have DI values of 10 dB or more, and are advantageous, for example, for better speech comprehension. If a hearing aid contains a microphone system with, for example, three omnidirectional microphones, then, on this basis, it is possible to simultaneously produce microphone units with zero to second order directional characteristics by suitable connection of the microphones.
A single omnidirectional microphone intrinsically represents a zero order microphone unit. If, in the case of two omnidirectional microphones, the microphone signal from one microphone is delayed and is subtracted from the microphone signal from the other microphone, then this results in a first order microphone unit. If, once again in the case of two first order microphone units, the microphone signal from one microphone unit is delayed and is subtracted from the microphone signal from the second first order microphone unit, this results in a microphone unit with a second order directional characteristic. Microphone units of any desired order can be produced in this way, depending on the number of omnidirectional microphones.
If a microphone system has microphone units of different order, then it is possible to switch between different directional characteristics, for example by connecting or disconnecting one or more microphones. Furthermore, any desired mixed forms between the directional characteristics of different order can also be produced by suitable electrical connection of the microphone units. For this purpose, the microphone signals from the microphone units are weighted differently and are added, before they are further processed and amplified in the signal-processing unit in the hearing aid. It is thus possible to achieve a continuous, smooth transition between different directional characteristics, thus making it possible to avoid disturbing switching artifacts.
In the case of two omnidirectional microphones, which are connected to form a microphone unit with a first order directional characteristic, the microphone signal delay for one of the microphone signals which originate from the microphones is normally set so as to compensate for the delay time of an acoustic input signal between the sound inlet openings of the microphones. The delay normally is chosen to be less than or equal to this delay time. If the delay is less than the external delay time between the sound inlet openings of the microphones (referred to as an “endfire array”), then a directivity index which has been weighted with the articulation index (AI–DI) of up to 6.5 dB can be achieved on the KEMAR (a standardized artificial head), for example with a mixed form of first and second order. If this ratio between the internal delay and the external delay time is increased to considerably more than 1, then this AI–DI value first falls rapidly and then becomes constant at values of 4.5 to 5 dB, in a manner which is very robust with regard to component tolerances of the microphones and any further increase in the delay time. As the delay is increased, however, the signal transmission response of the relevant microphone unit changes with respect to the sound signals that arrive at the microphone unit from the main direction. In this case, the main direction in general at least approximately matches the straight-ahead viewing direction of the hearing aid wearer, when the hearing aid is being worn. The frequency response of the microphone unit with respect to such acoustic input signals can be described, approximately, by the function:
H= 1− e jω(D ext +D int )
If the sum D ext +D int of the external delay time and of the internal delay is doubled, this results in an increase in the microphone output signal of about 6 dB, in the range of low signal frequencies, for example for a first order directional microphone, and in an increase of about 12 dB for a second order directional microphone. In this case, the microphone noise produced by the microphones remains approximately the same. The signal-to-noise ratio during directional microphone operation can thus be controlled with the aid of the internal, variable delay time. If this matching process is controlled adaptively as a function of the signal level of the acoustic input signal, then a high signal-to-noise ratio with AI–DI values of 4.5 to 5 dB, which are sufficient for these levels, can be achieved in a quiet environment. When the signal level of the acoustic input signal rises, a lower signal-to-noise ratio can be accepted, since the higher microphone noise associated with this is masked by the acoustic input signal. A variable AI–DI value is thus possible by adjusting the delay as a function of the situation, thus allowing better suppression of an interference signal from the side or from the rear when the acoustic input signal is loud.
The frequency response of a multiple microphone system according to the invention generally has a directionality operation behavior such that high frequencies are more strongly emphasized when the acoustic input signal level is low, while the gain for high frequencies is automatically reduced when the environment is loud, as in the case of AGC (automatic gain control). As an example, this applies to a conventional mixed form of first and second order directionalities. If required, an equalization filter can also be provided for a hearing aid according to the invention, which can be used to compensate for the AGC effect caused by the invention.
The matching of the internal delay time, or of the internal delay times, as a function of at least one microphone signal according to the invention may be carried out in discrete steps. However, the matching process is preferably carried out continuously with smooth transitions, so that the control process does not cause any switching artifacts.
In an embodiment of the invention setting of the delay of the microphone signal is not controlled directly by the signal level of the acoustic input signal, but by the signal level of the microphone output signal. For example, in an environmental situation in which there is no useful signal, or virtually no useful signal, from the direction in which the hearing aid wearer is looking, but the interference noise from the side or from the rear is relatively loud, then, in the case of a hearing aid according to the invention, exclusive consideration of the acoustic input signal picked up by an omnidirectional microphone would lead to relatively strong directionality being set, with increased microphone noise associated with this. Since, in the described situation, the interference signal is virtually masked out by the high directionality, the hearing aid wearer can be supplied with greater microphone noise, which is found to be disturbing. If the microphone signal that is actually emitted from the microphone system is taken into account, it would then be possible to reduce the directionality according to the invention to such an extent that the microphone noise is at least partially masked by the acoustic interference signal, which is then not suppressed to such an extent.
The invention offers the advantage that this adaptive control of the internal delay of a microphone signal allows the signal-to-noise ratio of the higher order multiple microphone system (n 3 1) to be controlled as a function of the signal level of the acoustic input signal and, possibly, also as a function of the incidence direction of the acoustic input signal. Particularly when the input signal levels are quiet, this makes it possible to avoid a high level of microphone noise, which is found to be disturbing.
The invention can be used for all known hearing aid types with an adjustable directional microphone, for example for hearing aids which can be worn behind the ear, hearing aids which can be worn in the ear, implantable hearing aids or pocket hearing aids. Furthermore, the hearing aid according to the invention may also be part of a hearing aid system which comprises a number of appliances for supplying someone with hearing problems, for example part of a hearing aid system with two hearing aids which are worn on the head, for binaural supply, or part of a hearing aid system comprising one appliance which can be worn on the head, and a processor unit which can be worn on the body.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a hearing aid with three omnidirectional microphones in accordance with the invention.
FIG. 2 shows the signal transmission response of a directional microphone system according to the invention, for two different delay times.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a circuit diagram of the basic components of a hearing aid with a directional microphone system according to the invention. The microphone system comprises three omnidirectional microphones 1 , 2 and 3 . The microphone signal that originates from the microphone 2 is delayed in a delay unit 4 A, is inverted by an inverter 5 A, and is added in an adder 6 A to the microphone signal R 0 which originates from the microphone 1 . Overall, the inversion and addition results in the microphone signal that originates from the microphone 2 being subtracted from the microphone signal that originates from the microphone 1 . The two omnidirectional microphones 1 and 2 thus form a microphone unit 1 , 2 with a first order directional characteristic, from which the microphone signal R 1 originates. In the same way, the microphone signal which originates from the microphone 3 is delayed in a delay unit 4 B, is inverted by an inverter 5 B and is added in an adder 6 B to the microphone signal which originates from the microphone 2 . The microphones 2 and 3 also thus form a microphone unit 2 , 3 with a first order directional characteristic, the microphone signal of which is produced at the output of the adder 6 B. If the microphone signal which originates from the microphone unit 2 , 3 is in turn delayed in a delay unit 7 and is inverted in an inverter 8 and is added in an adder 9 to the microphone signal R 1 which originates from the microphone unit 1 , 2 , then this results in the microphones 1 , 2 and 3 forming a microphone system 1 , 2 , 3 with a second order directional characteristic, whose microphone signal R 2 is produced at the output of the adder 9 .
The three microphone signals R 0 , R 1 and R 2 are supplied to a switching and filter unit 10 , in which it is possible to switch between the different microphone signals R 0 , R 1 and R 2 , or in which the microphone signals R 0 , R 1 and R 2 are differently weighted and added. The resultant microphone output signal RA which is emitted at the output of the switching and filter unit 10 is, finally, supplied to a signal processing unit 11 , in which the further processing and frequency-dependent amplification of the microphone output signal RA are carried out in order to compensate for the individual hearing loss of a hearing aid wearer. Finally, the processed microphone signal is converted to an acoustic signal, for emission through an earpiece 12 into the auditory channel of the hearing aid wearer.
The hearing aid according to the exemplary embodiment also has a level measurement and control device 13 , to which the microphone signal R 0 from the omnidirectional microphone 1 is supplied. This microphone signal is used to detect the signal level of the acoustic input signal that is currently arriving at the microphone 1 . The level measurement and control device 13 uses this signal level to produce parameters for adjustment of the delay in the delay units 4 A, 4 B and 7 , thus making it possible to influence the directionality, and if necessary to reduce the microphone noise, according to the invention.
In order to assess whether and to what extent a hearing aid wearer perceives microphone noise in a specific environmental situation, current hearing aid settings are preferably also taken into account, in addition to audiometric data relating to the hearing aid wearer (rest hearing threshold, masking threshold). These settings also relate in particular to the microphone system. For example, in the environmental situation with a high interference sound component, the evaluation of the microphone signal R 0 at the input of the microphone system results in the finding that the signal level of the acoustic input signal is high. However, it is possible in this environmental situation to largely suppress the interference signal by setting the microphone system to have high directionality, so that only a relatively quiet output signal is supplied to the hearing aid wearer. The microphone noise in this output signal can then possibly assume a clearly perceptible proportion of this output signal. For this reason, the delay time settings according to the invention preferably also take account of the microphone signals that originate from a directional microphone unit. In the exemplary embodiment, these are the microphone signals R 1 and R 2 . Furthermore, it is also possible to evaluate the microphone output signal RA that is produced at the output of the switching and filter unit 10 and is supplied to the signal-processing unit 11 for further processing. Taking account of the hearing aid characteristics and settings, it is then possible to use this signal to directly determine what signal level is actually being supplied to the hearing aid wearer in response to the current acoustic input signal, and the proportion of this that is represented by the microphone noise.
The instantaneous environmental situation can be identified well by evaluation of both a microphone signal that is produced by an omnidirectional microphone and the microphone signals from microphone units with a directional characteristic. In particular, it is also possible to estimate whether the proportion of the microphone noise in the microphone signal which is provided for further processing in the signal processing unit 11 can be perceived by the hearing aid wearer with the hearing aid settings at that time. An excessively high proportion of microphone noise in the microphone output signal leads to the level measurement and control device 13 for at least one of the delay units 4 A, 4 B or 7 increasing the delay setting until the proportion of the microphone noise in the microphone output signal reaches a value which is considered to be acceptable.
Conversely, if the microphone output signal is at a high signal level, and the microphone noise makes up only a small proportion of this, then relatively short delay times may be set for all three delay units 4 A, 4 B and 7 , thus increasing the directionality and suppressing the interference sound component in the acoustic input signal. In particular, the low frequencies also are reduced, and the high frequencies increased, during this transition. In order to avoid this effect, the level measurement and control device 13 also acts on the switching and filter unit 10 , so that the last-mentioned effects are largely compensated for by suitable filter settings.
Thus, overall, the invention provides the capability to change the setting of the directional microphone system in a quiet hearing environment, so as to prevent clearly audible and disturbing microphone noise. On the other hand, however, the advantages of a higher order directional microphone system are fully exploited in a loud hearing environment.
Another advantageous feature of the hearing aid according to the exemplary embodiment is that there is an electrical connection between the level measurement and control device 13 and the signal-processing unit 11 . The evaluation of the microphone signal or microphone signals in the level measurement and control device 13 can thus also be used for automatic situation identification, and thus for adaptive control of the signal processing in the signal processing unit 11 . Furthermore, it may also be possible to manually set hearing programs for different hearing environments in the signal processing unit 11 , with some of these hearing programs influencing the delay times according to the invention, while others do not. Provision is thus also made for signals to be transmitted from the signal-processing unit 11 to the level measurement and control unit 13 .
The signal processing in the hearing aid according to the exemplary embodiment may be carried out using analog, digital or combined circuit technology. Furthermore, the signal processing may also be carried out in parallel, in adjacent frequency bands (channels). The directional characteristic of the microphone system preferably also is set in frequency bands.
FIG. 2 shows the effects of adaptive directional microphone setting according to the invention, illustrated in the form of a graph. A first characteristic A shows the signal transmission response of a directional microphone system for one specific setting of the signal delay in the delay units in the directional microphone system. In this case, the internal delay is shorter than the external delay time of an acoustic signal that arrives at the microphone system from the front (viewing direction), with the microphones (and their sound inlet openings) being arranged one behind the other in the viewing direction. In a mixed form of first and second order microphone units, whose microphone signals are processed further jointly, it is thus possible to achieve a directionality value, weighted with the articulation index AI–DI of up to 6.5.
The frequency response of the microphone system is described by a function in the form:
H= 1− e jω(D ext +D int )
In this case, the characteristic shows the typical high-pass behavior of a higher order directional microphone system. According to the invention, the transmission characteristic A is selected in particular in a loud hearing environment.
If the signal level of the acoustic input signal falls, or the proportion of the microphone noise in the microphone output signal which is produced by the microphone system is dominant, then the signal delay for at least one microphone signal in the directional microphone system is increased, which, in the event of the internal delay being doubled in comparison to the external delay time, results, for example, in a transition from the signal transmission response of the directional microphone system from the characteristic A to the second illustrated characteristic B. This is higher by about 6 dB than the characteristic A. In contrast, the microphone noise remains approximately constant. Although the internal signal delay initially results in the AI–DI value decreasing, it then becomes constant, however, at values of 4.5 5 dB, even if the internal delay is increased further, thus still resulting in relatively good directionality. Thus, overall, the signal-to-noise ratio in the directional microphone mode can be controlled with the aid of the internal delay times, which can be set electrically.
Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.
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In a hearing aid, as well as in a method for the operation of a hearing aid having a microphone system in which different directional characteristics can be set, the tonal quality is improved, particularly in a quiet hearing environment, by the signal delay for at least one microphone signal being increased so as to increase the transfer function in the frequency response of the microphone system, thus also improving the signal-to-noise ratio, by decreasing the proportion of the microphone noise in the microphone output signal.
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TRADEMARKS
[0001] IBM® is a registered trademark of International Business Machines Corporation, Armonk, N.Y., U.S.A. Other names used herein may be registered trademarks, trademarks or product names of International Business Machines Corporation or other companies.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to computer systems, and more particularly to a method for managing resources during system initialization startup and run time operation.
[0004] 2. Description of the Related Art
[0005] Computer systems and servers, when faced with an error condition, have generally taken a resource from “configured” and changed the resource's state to “deconfigured” or not usable. In most instances, hardware is deconfigured to remove the error condition. However, this blind deconfiguration of resources can leave the computer system in a degraded performance state and/or a degraded availability of resources, without the user or client being able to decide what is best for their needs or requirements.
[0006] Clients run many different types of applications on computer systems. Applications can vary in their needs from requiring the most resources possible or quantity (Mode one), or to requiring the fastest resources possible or speed (Mode two). For example, certain applications or uses require a vast amount of memory (quantity) such as a large document, while other applications require fast execution or computational speed such as a complex simulation or modeling program. Therefore there is a need for a user configurable algorithm that defines a computer system's behavior when faced with a failure or error condition.
SUMMARY OF THE INVENTION
[0007] Embodiments of the present invention include a method and system for managing computer resources wherein the method includes: detecting an error condition in a computer resource; labeling the computer resource as not usable based on the error condition detected; reconfiguring the remaining computer resources to compensate for the detected error condition based on a failure mode policy; and wherein the failure mode policy manages the computer resources by one of: maximizing the amount of the remaining computer resources (mode 1), and maximizing the speed of the remaining computer resources (mode 2).
[0008] A system for managing computer resources, the system includes: a set of hardware resources; an algorithm for managing the set of hardware resources; wherein when the algorithm detects an error condition in a hardware resource, the hardware resource is labeled as not usable based on the error condition detected; wherein the algorithm reconfigures the remaining hardware resources to compensate for the detected error condition based on a failure mode policy; wherein the failure mode policy manages the set of hardware resources; and wherein the failure mode policy either maximizes the amount of the remaining hardware resources (mode 1), or maximizes the speed of the remaining hardware resources (mode 2).
[0009] Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
TECHNICAL EFFECTS
[0010] As a result of the summarized invention, a solution is technically achieved for a user configurable algorithm that defines a computer system's behavior when faced with a failure or error condition. The algorithm allows the user to overcome an error condition, by either optimizing the computer system speed or through put, or by maximizing the quantity of the available system resources.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The subject matter that is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0012] FIG. 1 is a flow diagram of an algorithm for overcoming an error condition in a computer system, by either optimizing the system speed or throughput, or by maximizing the quantity of the available system resources according to an embodiment of the invention.
[0013] FIG. 2 illustrates a system for implementing an algorithm for overcoming an error condition in the system according to an embodiment of the invention.
[0014] The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION
[0015] Embodiments of the invention provide a user configurable algorithm that defines a computer system's behavior when faced with a failure or error condition. The algorithm allows the user to overcome an error condition, by either optimizing the computer system's speed or throughput, or by maximizing the quantity of the available system resources.
[0016] Embodiments of the algorithm of the current invention may be used in a computer system that has the ability to remove or deconfigure resources and still progress with initial program load (IPL), or boot the system for usage. Booting up is the process of powering on, initialization of the computer hardware, running diagnostics of the computer hardware, and the loading of the operating system. Boot firmware is software code with the logic that controls the booting up process. Usage of the algorithm starts with the customer being able to set a given hardware resource, such as memory, processors, input output interfaces (IO), networking devices, etc., to the deconfiguration mode that best fits the system usage or customer needs in case of a system related failure. The algorithm does not change the configurations or initialization parameters when there is no error encountered in the system.
[0017] Embodiments of the algorithm of the invention can be used for system errors encountered during IPL (boot), or during run time of the system.
[0018] For example, if an error is detected by the system's diagnostics during IPL (system boot up), and a system resource such as a dual in-line memory module (DIMM) group is labeled (marked) as not usable in the current configuration, then the DIMM group would be set for deconfiguration and removal from the system, with the loss of all that resource (4 DIMMs of X size) prior to the use of an embodiment of the algorithm of the present invention. By utilizing the algorithm, the system can look at a failure mode policy, as set by the user, (mode one—memory availability or mode two—memory performance) when an error occurs, and do one of the following.
[0019] Mode one determines if the resource may be reduced in size or speed in order to keep the maximum amount of resource (memory) in the system based on the error. For example, current server systems run a group of 4 DIMMs for a fast memory group, and upon a detected error the server system may be initialized to use a group of 2 DIMMs for a slower access to memory. If the problem is in the frequency of the bus to the memory, then the speed could be initialized to a slower speed and the resource (memory) left in the system.
[0020] Mode two attempts to keep the system at the highest performance possible. For example, server systems that run a 4 DIMM group experiences a performance loss (slowing the memory bus speed) by moving to a 2 DIMM group, so the algorithm would remove all resources (memory).
[0021] In the case of a run time failure, when the system diagnostics detect a resource (memory) error that is recoverable, the error is monitored for an error threshold. If the threshold is met, a report of service action is initiated, but the runtime condition does not change. However, during the next IPL, the system is placed in a “Persistent Deconfiguration and MODE change.” For other runtime errors that are not recoverable and that may cause the system to crash, the system is sent immediately into a “Persistent Deconfiguration and MODE change.”
[0022] In embodiments of the present invention the “Persistent Deconfiguration and MODE change” may be a mode-one memory error that would try and keep the most memory in the system as possible. A mode-two memory error would keep the memory in the system that can be configured to be the fastest. The user determines the mode based on the application or applications running on the system that require the most resource “X” as possible. The resource allocation required might be the need for the maximum amount of memory (mode one), such as programs that use large amounts of memory that would cause parts of the file to be cached in and out of memory. However, the user may have the same system ruining an application or applications that require the fastest resource “X” as possible. The resource allocation might be the need for Memory to move data in and out at the fastest speed possible.
[0023] FIG. 1 is a flow diagram of an algorithm for overcoming an error condition in a computer system, by either optimizing the system speed or throughput, or by maximizing the quantity of the available system resources according to an embodiment of the invention. The algorithm is started (block 100 ) when the system is booted (block 102 ). If the system successfully boots (block 104 is false) with no hardware loss (block 110 ), the hardware initialization is continued (block 118 ) and boot system diagnostics (block 120 ) are carried out. If the boot system diagnostics proceed without detecting an anomaly (block 122 is false), and the system achieves a run time status (block 124 ), the system continues to run until it is shutdown by the user or a run time failure (block 126 is true) is encountered. When a run time failure is encountered, the hardware is marked unusable (block 128 ) and the system is rebooted (block 102 ) to see if the failure condition still exists (block 104 is true). If however during boot system diagnostics (block 120 ) an error is detected (block 122 is true), the hardware is marked as unusable (block 106 ) and is checked for loss of usage (deconfigured) (block 110 ). If the hardware is lost (block 110 is true) the policy (block 112 ) with regards to resource utilization of the algorithm of an embodiment of the invention is consulted as to whether to maximize system resources (block 116 )—emphasis on not losing additional hardware, or to optimize system speed (throughput) (block 114 ). If system speed (block 114 ) is the objective, additional hardware may be deconfigured. Following the policy decision (blocks 112 , and block 114 or block 116 ), the hardware is initialized (block 118 ) and boot diagnostics (block 120 ) proceeds as previously described.
[0024] If boot failure (block 104 is true) occurs immediately on system startup the sequence of marking the hardware unusable (block 106 ) and checking for a hardware loss (block 110 ) proceeds as before with the use of the resource utilization policy (block 112 ) if hardware is deconfigured (block 110 is true).
[0025] FIG. 2 is a block diagram of an exemplary system 200 for implementing a user configurable algorithm that defines a computer system's behavior when faced with a failure or error condition according to an embodiment of the present invention, and graphically illustrates how these blocks interact in operation. The system 200 includes remote devices including one or more multimedia/communication devices 202 equipped with speakers 216 for implementing the audio, as well as display capabilities 218 for facilitating graphical user interface (GUI) aspects for setting resource utilization policies of the present invention. In addition, mobile computing devices 204 and desktop computing devices 205 equipped with displays 214 for use with the policy utilization GUI of the present invention are also illustrated. The remote devices 202 and 204 may be wirelessly connected to a network 208 . The network 208 may be any type of known network including a local area network (LAN), wide area network (WAN), global network (e.g., Internet), intranet, etc. with data/Internet capabilities as represented by server 206 . Communication aspects of the network are represented by cellular base station 210 and antenna 212 . Each remote device 202 and 204 may be implemented using a general-purpose computer executing a computer program for carrying out the GUI described herein. The computer program may be resident on a storage medium local to the remote devices 202 and 204 , or maybe stored on the server system 206 or cellular base station 210 . The server system 206 may belong to a public service. The remote devices 202 and 204 , and desktop device 205 may be coupled to the server system 206 through multiple networks (e.g., intranet and Internet) so that not all remote devices 202 , 204 , and desktop device 205 are coupled to the server system 206 via the same network. The remote devices 202 , 204 , desktop device 205 , and the server system 206 may be connected to the network 208 in a wireless fashion, and network 208 may be a wireless network. In a preferred embodiment, the network 208 is a LAN and each remote device 202 , 204 and desktop device 205 executes a user interface application (e.g., web browser) to contact the server system 206 through the network 208 . Alternatively, the remote devices 202 and 204 may be implemented using a device programmed primarily for accessing network 208 such as a remote client.
[0026] The capabilities of the present invention can be implemented in software, firmware, hardware or some combination thereof.
[0027] As one example, one or more aspects of the present invention can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer usable media. The media has embodied therein, for instance, computer readable program code means for providing and facilitating the capabilities of the present invention. The article of manufacture can be included as a part of a computer system or sold separately.
[0028] Additionally, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform the capabilities of the present invention can be provided.
[0029] The flow diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
[0030] While the preferred embodiments to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may male various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.
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A method for managing a system's computer resources, includes: detecting an error condition in a computer resource; labeling the computer resource as not usable based on the error condition detected; reconfiguring the remaining computer resources to compensate for the detected error condition based on a failure mode policy; and wherein the failure mode policy manages the computer resources by one of: maximizing the amount of the remaining computer resources (mode 1), and maximizing the speed of the remaining computer resources (mode 2).
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FIELD OF THE INVENTION
[0001] The present invention relates to maintaining plants in a healthy state when the plant is stored at a nursery, during transportation, maintenance at a retail outlet or nursery and/or subsequent transplantation. In particular, this invention relates to selectively providing nutrients subterraneously to the plant thereby promoting root growth.
BACKGROUND OF THE INVENTION
[0002] Growing, transporting, and transplanting plants has become a large industry. The suppliers and sellers of such plants to the consuming public need to provide plants that are healthy and once transplanted will grow to the satisfaction of the buyer. In order for this to be done, the plant must be maintained in a healthy environment during transportation, maintenance at a nursery or other retail establishment, and during transplantation. If the plant is not maintained in a healthy state, the buyer will be dissatisfied and may even ask for a refund or another new plant to replace the original plant purchased. It is important therefore to provide plants in the healthiest environment to the purchaser such that once the plant is transplanted, it grows to the satisfaction of the purchaser.
[0003] Many plants are transplanted and transported by surrounding the roots of the plant with a fabric, such as burlap, to form a ball structure. The quality and preparation of the root ball may very well determine how well the plant survives during transportation and transplantation. A typical scenario in transplanting a plant with a root ball is to leave the plant to its own survival once the root ball is placed in the planting hole. At best fertilizer is thrown into the hole or after the root ball is covered with dirt applied to the surface of the soil.
[0004] Hand sprinkling fertilizer or other plant nutrients into the planting hole results in a majority of the fertilizer and other nutrients falling to the bottom of the hole and therefore not being available to the root ball in a way that the root ball (plant roots) can uptake the fertilizer or other plant nutrients in an efficient manner. Throwing fertilizer onto the top surface of the soil may help a little more, but again, the fertilizer and/or other nutrients have to reach the roots efficiently for optimizing uptake by the plant.
SUMMARY
[0005] This disclosure describes a method of promoting plant and/or root growth of a plant to be transplanted. The method comprises encompassing the roots of the plant within a base sheet of material containing at least one selected area on the base sheet facing the roots, the at least one selected area on the sheet containing selected nutrients for promoting plant and/or root growth
[0006] This disclosure also describes a device for containing plant roots and promoting plant and/or root growth. The device comprises a base sheet of material comprising at least one selected area on the base sheet facing the roots, the at least one selected area on the sheet comprising selected nutrients for promoting plant and/or root growth.
[0007] This disclosure further describes a plant suitable for transportation and transplantation. The plant comprises a root ball, whose roots are contained within a flexible fabric in the general form of a ball, the fabric comprising at least one area facing the roots of the plant, the at least one area including selected nutrients for promoting root growth and/or plant growth.
DETAILED DESCRIPTION
[0008] Providing nutrients, air and water to newly planted, transplanted or transported plants is important for expecting a high survival rate as well as vigorous, uniform and sustained plant growth. Over the past decades, it has been clearly demonstrated that the total environment of the plant must be considered if these goals are to have a reasonable promise of attainment.
[0009] This disclosure describes a system of controlled nutrient delivery for plants. The system provides a predetermined and carefully measured quantity of nutrient, biological, organic and inorganic components to all plants intended to be planted, transplanted, or transported including trees, shrubs, vegetables, fruits, and flowers. Placement and adhesion of essential organisms on to a substrate are described. The substrate is composed of biodegradable (preferably) mesh such as burlap fabric, which is then wrapped around the roots of a plant and earth to form a “root ball.” The system described herein will “complete” nursery grown plants by introducing beneficial mycorrhiza (fungi), beneficial bacteria and other beneficial organic and inorganic components to the roots, which will be activated at the time of planting to provide the plants with a full, functioning system. For purposes of this application, such beneficial mycorrhiza (fungi), beneficial bacteria and other beneficial organic and inorganic components may be referred to as “inoculants”.
[0010] The system described in this disclosure presents the inoculants in a manner such that the nutrients are automatically delivered to the root system of the plant in an optimal manner. The system can also be used to create a “cocktail” of seed, fertilizer, inoculants, air entrainment and water storage materials which will “re-seed” open earth excavation while preventing soil erosion until the seeds germinate.
[0011] Another feature of this disclosure is to allow for the uniform inoculation, and even distribution around the root ball of biological components and organic fertilizers, which include mycorrhiza fungi and beneficial bacteria (nutrients). Other ingredients may be added or ingredients removed to create plant specific formulations. These materials create an environment that permits the establishment of a symbiotic relationship between mycorrhiza fungi and plant roots and promote the ability of the soil organisms to convert organic and inorganic compounds into a self sustaining source of continued plant nutrients. The even distribution of the inoculants assures uniform growth and a sustainable food supply.
[0012] The need to further nurture plants by modifying the soil itself is vital and best served by introducing “inoculants” of soil bacteria, fungi and other compounds, which are essential to the establishment of healthy plants by breaking down existing organic and inorganic compounds and converting them to a source of sustainable food. A self cyclic and nourishing environment has to be created to produce a thriving and healthy plant for sale. Such a healthy plant is the result of placing the proper biological components in controlled amounts in the proper location, and with an adequate and uniform supply of water and air so that the plant roots can uptake in an optimal fashion. All of the following must be considered and accommodated if there is to be a high degree of healthy plants for sale to buyers:
Blend of standard “fertilizers”; Controlled location and uniform water and air storage capacity of surrounding soil; The precise selective placement of soil “inoculants” to assist the plant's ability to associate symbiotically with organisms in the ground to reduce susceptibility to disease, provide fertilizer and water storage needs and to utilize the soil's natural organic and inorganic compounds by converting them to long as well as short term sources of food; and Careful control of the quantity and uniform placement of vital biological components are designed to nurture the plant through early growth and establishment.
[0017] Bacteria are a vital additive in sustaining root growth and enhancing biological activity, the benefits of which include but are not limited to;
Promoting nutrient solubilization and mineralization; Enhancing nutrient uptake; Enhancing photosynthetic capacity and reducing supplemental Nitrogen, Phosphorus and Potassium requirements; Bacteria contain L-Cystene, L-Glycine, L-Glutamate to facilitate production of Glutathione, a potent abiotic Stress Reducer; Bacteria contain L-Tryptophan to facilitate production of Indole Acetic Acid (IAA), a natural phyto-hormone responsible for triggering flowering mechanism; and Bacteria that contain high concentrations of sugars which supplement plant's increased requirement during the flowering phase.
[0024] In current nursery production the root to plant symbiosis of beneficial and essential fungi and bacteria does not exist due to the intense management aimed at growing plants to specific physical specifications. Most nursery production follows the American Standard Nursery Stock, a specification almost entirely focused on the physical aspects of plant growth and production. In fact, the document, which is 129 pages in length, does not mention the word “healthy” until page 36. Plants and their roots that are grown in production nurseries have not developed the symbiotic relationships with natural fungi and bacteria.
[0025] This disclosure also describes a method for making a root ball that maintains the health of a plant during transport and at a nursery and once planted continues providing the plant with nutrients to enhance its growth. Burlap is an exemplary material for surrounding the roots of a plant in a ball formation. The burlap that has been used is a coarse, loosely woven, fabric made from Jute or similar type plant material. Jute is plant fiber derived from plants belonging to the genus Corchorus . Such fiber is well-known and is second only to cotton in amount produced. Since the material is plant derived, it is inherently biodegradable. Burlap fabric is a basic component for almost all packaging of field-grown plants intended for transplant because burlap confines and contains the soil. Containing the soil around the root system minimizes “shock” to the plant during digging the plant up from its initial growth area and then during transportation. Burlap is flexible thereby permitting formation of a ball around the plant roots. The burlap is cut to size in order to accommodate varying root ball sizes.
[0026] The burlap is buried when the plant is transplanted again minimizing disturbing the soil around the roots and continuing the friendly environment in which the root system was transported. Once the plant is transplanted, burlap permits the roots to grow through the burlap while the burlap slowly biodegrades during this stage of the growth all the while keeping the root ball intact. The burlap through its inherent properties minimizes disturbance of the plant's roots.
[0027] The burlap base material provides a stable and flexible attachment base or substrate for the adhesive and blended nutrients that are part of this disclosure. Other materials besides burlap may be used. Such materials should contain the attributes of burlap that are described herein such as biodegradability, flexibility, permitting roots to grow through after transplantation and the ability to retain and hold nutrients in selected positions such that the nutrients are presented to the plant roots in a manner that optimizes plant growth and health.
[0028] The base material is modified to retain the nutrients at selected positions. An adhesive emulsion base material is sprayed on the base material. The adhesive emulsion is, for example, an adhesive of biodegradable materials such as carboxyl methyl cellulose modified with sucrose or starch. Additionally, an acrylic emulsion has proven acceptable as an adhesive for the production needs of the system.
[0029] Once prepared with a layer of the adhesive, a layer of blended nutrients or a fertilizer mixture is next deposited on the adhesive emulsion base material. For example, the fertilizer mixture can comprise beneficial fungi, beneficial bacteria and additional beneficial organic and inorganic compounds. The fertilizer mixture of essential organisms includes beneficial fungi which can be, but are not limited to;
Diverse multi strains endomycorrhiza; Diverse multi-strains ectomycorrhiza; and Diverse multi-strains Trichoderma;
and/or beneficial bacteria which can be, but is not limited to
Bacillus firmus; Bacillus amyloliquefaciens; Bacillus subtilis; Bacillus licheniformis; Bacillus megaterium; Bacillus pumilus; Bacillus azotoformans; Bacillus coagulans; Geobacillus stearothermophilus; Paenibacillus polymyxa; Paenibacillus durum; Pseudomonas aureofaceans; Pseudomonas fluorescence; Pseudomonas putida; Streptomyces coelicolor; Streptomyces lydicus; and Streptomyces griseus;
and/or beneficial organic and inorganic components which can be but no limited to;
Humic acid; Amino acids; Proteins; Vitamin B Complex; Sea kelp extract; and Polyacrylamide copolymer superabsorbent
[0056] For example, the following amounts of beneficial bacteria have proven to be effective;
100,000,000 Colony Forming Unit (CFU) per gram of the following organisms; Bacillus firmus, Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus coagulans, Geobacillus stearothermophilus, Paenibacillus polymyxa, and Paenibacillus durum; 100,000,000 CFU per lb of Bacillus azotoformans ; and 20,000,000 CFU per gram of Pseudomonas aureofaceans and Streptomyces lydicus , 22,000,000 CFU per gram of Pseudomonas fluorescence, Pseudomonas putida, and Streptomyces coelicolor, Streptomyces griseus, Trichoderma reesei, Trichoderma hamatum, Trichoderma harzianum.
[0060] Other materials that may be added to create “plant specific” formulations include iron, calcium compounds, and organic fertilizers. These compounds will vary with the target plant and will be tailored to maximize establishment of a symbiotic mycorrhizal association. Inert particulate substances such as heat-treated vermiculites and/or perlite aerate the soil and optimize essential root respiratory processes, and so these “aerators” are also included in the mixture for maximum effectiveness.
[0061] The predetermined nutrient mixture is adhered in a dry and unaltered form to the burlap mesh fabric by the adhesive emulsion base material to form a tough permeable layer of dry nutrients typically equally dispersed over the entire surface of the burlap wrapping material. For example, the amount of each ingredient is carefully measured and uniformly distributed over the entire surface. Alternatively, each ingredient may be distributed to selected individual or controlled areas of the base in order to target different nutrient contact with different areas of the root ball/root system.
[0062] This procedure is repeated until a sufficient (effective) amount of biological organic, and inorganic components is deposited to form a composite product sheet. After manufacture, the composite product sheet may be further processed to form virtually any shape needed for the particular root system of the plant and/or for marketing purposes or convenience to the customer. Such shapes include but are not limited to sleeves, socks, or bags designed to hold the roots of various plants for transport, transplant, storage, or point-of-sale presentation to the buyer. The sleeves, socks and bags are designed to hold the roots of a plant during transport, watering, storage and planting cycles.
[0063] Alternatively, the fertilizer mixture can be applied to targeted portions of the burlap depending on the needs of the plant species/variety. The mixture can be adjusted depending on the specific needs of the individual plant species/variety. The system allows for easily customized formulations to assist the plant's survival and prosperity in varied climates and/or soil conditions. For example, the amount of SAPs (super absorbent polymers) may be increased when planting in highly permeable soils (sand) and may be permanently enhanced by the addition of sodium montmorillonite clay (Bentonite), thus decreasing the permeability and increasing the water retention of the soil. Such a system is may then be “locked in” place by a final layer of a degradable adhesive polymer on a side of the nutrient system opposite from the burlap base material.
[0064] The flexibility of the biodegradable burlap holds the soil firmly in place while holding the nutrients completely around the root ball and permitting water to enter the root ball and be retained by for example by SAP. The system of the present invention thus prevents erosion while watering the plant during transport and storage prior to sale by holding the soil, roots and nutrients in place. Additionally, the system of this disclosure also allows the growing roots to easily grow through and into the surrounding soil once the plant has been permanently transplanted in the ground.
[0065] Similarly, tubes of paper, plastic and other composites may be used as base material to accomplish the even distribution of biological, organic, and other components in growing systems where plants are grown in cells, flats, containers, drums, boxes, and other configurations and a “sleeve” containing evenly distributed previously mentioned fertilizers, inoculums, super water absorbers, fungi, bacteria, etc. that are used to enhance plant health and growth. As with the burlap base material described previously, an adhesive layer is applied to the paper, plastic, or other composite that is used as the base material and the cocktail of nutrients is then applied continuously or in selected positions on the base material. The roots of the plant that are contained within the tube of paper, plastic, or other composite material can then partake in an optimal and efficient manner of the nutrient cocktail. It has been shown that plants grown in such an environment are much larger and healthier when compared to plants grown in a typical prior art growing container.
[0066] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A method and device for containing or encompassing the roots of the plant comprises a base sheet of material containing at least one selected area on the sheet facing the roots, the at least one selected area containing selected nutrients for promoting plant and/or root growth.
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[0001] Priority is hereby claimed to U.S. provisional patent application No. ______ filed on ______.
BACKGROUND OF THE INVENTION
[0002] There has been extensive work in reasoning about the data in databases going back over 40 years. This work encompasses monotonic reasoning, best known in the guise of automatic theorem proving, and non-monotonic reasoning of truth maintenance.
[0003] There has been extensive work in the area of applying Bayesian probability measures to complex situations, notably the work of Judea Pearl (Probabilistic Reasoning in Intelligent Systems : Networks of Plausible Inference), who maintains a bibliography of over 1000 references. Results are documented in many conferences on uncertainty reasoning. The only known practical example of the application of this formalism has been in text retrieval. The INQUERY system, developed at the University of Massachusetts at Amherst uses the relative occurrence of words in documents as an estimate of probability and then performs a Bayesian net inference on the data.
[0004] There has been extensive literature in fuzzy sets. For a baseline see Klir's “Fuzzy Sets and Fuzzy Logic: Theory and Applications”, and “Uncertainty-Based Information : Elements of Generalized Information Theory.” Again, the question arises on how to assign fuzzy measures. For a small number of measures of simple systems they can be assigned by a human being. This breaks down when the problem becomes too complex.
[0005] Baconian measures have not been applied mathematically and systematically except in a few academic settings. They have not been used as a technique to compute fuzzy measures.
[0006] The use of filters was discussed in great detail by Lucian Russell in “Posits and Rationales”, a Ph.D. dissertation at George Mason University. It has been submitted as documentation for patents in 1998.
[0007] Computer representations of information are stored in a database. The following definitions are those generally used by Information Technology standards bodies. A database consists of data elements and their relationships and the range of values that the data representation is expected to assume. The data that describes other data is called metadata. The metadata structure of data in terms of groupings of data and linking of groupings is the schema. The metadata structure that describes the expected range of values is called the integrity constraints. A database that is organized into a set of tables, where linkages among tabular entries are represented by explicit data values present in those tables, can be called a relational database. This is because the tables are a representation of the mathematical construct called a relation. The term relation is mathematically defined whereas the term relationship has a more general meaning, and requires a context in which it is precisely defined.
[0008] A relational database has the property that any of its data elements can be reassembled into another table using a combination of three operations, select, project and join. A complex operation consisting of the use of these operations, perhaps multiple times, is a query. The use of a sequence of queries can also be used to create new tables. This process has been mathematically demonstrated to be identical, under three assumptions, to be the same as proving an equivalent mathematical theorem using that data. Because of this fact a process that queries data is a reasoning process. Therefore the Platonic Reasoning Process is also a Platonic Querying Process.
SUMMARY OF THE INVENTION
[0009] The distinguishing feature of the PRP is that it provides a means to answer a query about a database when the data in the database is not complete or is not considered to be trustworthy. The adverb Platonic is used to describe the reasoning process because of Plato's metaphorical description of how human beings perceive reality. The metaphor was one of a fire in a cave. Plato said that human beings cannot perceive objects in the real world in their exact form. If an object were in a cave, a fire in the cave would cast a shadow of that object on the wall. That shadow, however, would alter shape and the edges would appear to flicker. A person in that cave facing the wall would not be able to see the true form of the object, only the shadows. However, by looking at those shadows it would be possible to get a good approximation of the shape of the actual object. That is the intent of the PRP, to process the data as so as to obtain a good approximation of the object in the real world that the data represents.
[0010] The most general type of schema structure is called an Ontology. It provides a structure, frames containing slots, with inter-frame linkages, that is so general that it suffices to represent all the different varieties of metadata that have been found to be useful, and it can be extended to encompass new types of metadata. The Ontology provides the description of the data about the real world that, if available, represents the object of set or objects (1) about which data is collected and (2) queries made. In other words the Ontology can represent the database that describes the ideal description, the one that we would wish to obtain. The Ontology, because of its generality, can also describe the limitations that existed and constrain the completeness and accuracy and validity of the data that was actually collected in the real world.
[0011] Therefore the Ontology is the means whereby we (1) organize the computer representations of information together with the representation of the presumed relationships that exist among elements of that information, and (2) applies and records corresponding measures of completeness and correctness of that information.
[0012] The third step in the process is to generate new measures. The process is valuable because it is a means to generate “fuzzy” measures. The discipline of “Fuzzy Sets” and “Fuzzy Logic” has been well established for over 35 years; it is the mathematics that results from generalizing the binary function describing the membership relation of subsets of a set to a more general function. A binary relation is a mapping of an element “a” of a set “A” and a subset “S” of “A” to one of two numbers, “1” or “0” depending on whether “a” is said to be a member of the subset “S”. This mapping is called the membership function. When the mapping is not just to “1” or “0” but to numbers in between then the membership function is “fuzzy”.
[0013] Fuzzy measures and the resulting fuzzy logic has been well accepted in the United States because of a linguistic prejudice against the word “fuzzy”. The mathematics, however, exists independent of linguistic conventions, and has been applied successfully to many industrial processes in Japan, where patents have been granted. In general the strength of the methods based on “fuzzy logic” is that they are used to create a simpler mathematical model of the control processes that need to be managed, which enable the creation of more efficient techniques for controlling the automatic operation of machinery.
[0014] Although the usefulness and applicability of fuzzy mathematics is well demonstrated for nearly two decades, the extension of these methods to more general, non mechanistic problems has been halted by the difficult in setting forth general criteria by which to assign the measures to real world data. A similar problem exists in using probabilistic techniques that are called “Bayesian”. These require the generation of a large number of initial probability values that must be assigned to data, and the task of generating these probabilities has proved to be too complex for the technique to be useful to real problems, with the exception of the Computer Science discipline of Information Retrieval.
[0015] The PRP, however, provides a mechanism for generating fuzzy measures. These are the “new measures” that provides a measure of a new category of information that summarizes the information available concisely. The latter summarization is what is done when fuzzy measures are applied in mechanical control systems. The process allows for two techniques to be applied, linguistic variable mapping and precision through abstraction.
[0016] 1. Linguistic variables are words assigned to ranges of data values. An example is the risk of an investment in a company's stock where the chance that you would make a 100% profit on your investment would be characterized by one of the words “certainly, probably, plausibly, possibly, conceivably and inconceivably”.
[0017] 2. Abstraction occurs when detail is omitted. If values for three variables are needed to describe an object, but only two are certain, one may define a new object that is described by just the two variables. For example to designate an area as a “mountain” one needs the height of the object, whereas a “mountain range” is a flat area on the map that has both mountains a non-mountainous areas. Lacking the height coordinate the latter more abstract term is appropriate.
[0018] Using a-priori principles is one way of assigning the value of fuzzy measures. The PRP however, uses a more novel technique whereby the measures are induced by the data. There are several meanings for the word induction, but the one that is intended here is the one from electromagnetic theory. In this theory an electric charge moving through a conductor induces a magnetic field, and if another conductor is placed in the same field a current in the opposite direction. The data that is actually loaded into the database creates a series of objects which generate an description of those objects with respect to the description loaded in the Ontology.
[0019] The foundation of this technique is the application of implicit functions. In mathematics a function is a table of values, like a relation, with some restrictions. Usually people describe functions “intensionally”, by a formula, especially if the formula has an infinite number of values like x*x=y. An alternative is to describe functions “extensionally”, as a table where all values are explicitly recorded. Any given relational database can be described as a set of extensionally defined functions. These can in turn generate self-describing measures, of which one familiar example is quartiles (quartiles are four groupings of numerical values within a set of numbers from the lowest to the highest). By applying measures created by self-describing functions to the database it is possible to create fuzzy measures. These measures are then applied to the data in the database. The data and their fuzzy measurements enable the us of reasoning, the application of rules of the form “If X then Y” where the logical expressions X and Y contain terms that include the fuzzy measures.
DETAILED DESCRIPTION
[0020] The PRP is realized by adding a set of processes, realized in software, into a system that performs reasoning on data. The PRP is the process of reasoning about the set-up of the data that will be used by process that reasons on exact data. Some basic processing functions are common to both types of reasoning, and so the software will share some programs in common. The baseline system components perform reasoning on exact data. As explained above, reasoning about a hypothesis using data in a database is the same thing as running a set of programs that perform a query on the database. That is because a hypothesis that can be validated or disproved on a data base has the form “there exist data elements in the database form Y that match the description X” can be proven by the query “select all data from D that match the description X”. If no such data exists the query returns no data and thereby disproves the hypothesis.
[0021] The system will be shown in terms of a software Architecture diagram, one which identifies software components with special functions that interface with one another. The Architecture of the system is shown in FIG. 1. It is a 3-tier architecture; the terms layer and tier will be used interchangeably. The first tier contains a user interface, a software client, that sends data to and receives it from software on the second tire, the middleware layer. At the bottom of the Figure, Tier 3 , are Database Management Systems (DBMSs) accessing databases containing the original information that the system must access.
[0022] The baseline reasoning process without any PRP functions is simple. In the Client Tier there is a box that says “Reasoning Chains and Filter Editor” and one that says “Display Results”. The Reasoning Chain is the statement of the hypothesis to be proved, which may also be seen as a set of queries. There are no filters in this case. The results of the queries are displayed where indicated, if there is data to be displayed, and a “no data found” message is displayed otherwise. The software interacts along the path shown as the narrow, black think lines with triangular solid arrowheads. Note that the PRP Plug-In is bypassed and the SQL 3 Engine is directly accessed. The Object-Relational Database Management System is a standard middleware software Commercial Off the Shelf (COTS) software component, used to overcome formatting differences among the different data sources.
[0023] The description in FIG. 1 covers the case where the PRP is used.
[0024] Tier 1
[0025] 1. The Ontology Editor is the interface to the Ontology Builder (an example is available at the Knowledge Sharing Laboratory, www-ksl.stanford.edu at Stanford University). An Ontology is a general representation format for systems that represent knowledge about data items and their inter-relationships, including the various elements of metadata that describe the data. When an instance of an Ontology is built it will contain descriptions of (1) the ideal collection of descriptive data, (2) the data that is actually available, (3) transformations that are admissible between the two formats, (4) functions used to filter data that will be transformed, and screens that support the generation of new measures and objects that are the result of the PRP. This interface supports the first part of the PRP: it organizes computer representations of information together with the representation of the presumed relationships that exist among elements of that information.
[0026] 2. The Results Display Engine is an interface to COTS products on the client platform that are used to view the results of performing reasoning using the PRP.
[0027] 3. The User Interface for Reasoning Chains: This user interface is to two things, build the hypothesis and its associated reasoning chain (or query sets) and assign uncertainty management conditions. This supports the first half of the second part of the PRP: it records the measures of correctness corresponding of the information that will be used. It also feeds rules to any reasoning engine that may be needed to enhance the functionality of the Object Relational Database.
[0028] 4. The Screens Editor is the interface to the Ontology builder that is used to support the second half of the second part of the PRP: record the measures of completeness corresponding to the information that will be used.
[0029] In addition there are system administrators who need interface with the system through COTS product interfaces. These are:
[0030] 5. The Command Center: The Object Relational Database's Interface
[0031] 6. Math Function Editor: This is an environment for building programs that are compiled and inserted into an executable program library for use in the Object Relational database by the PRP.
[0032] Tier 2 , the Middleware
[0033] Middleware is used to assemble data from multiple data sources, shown as databases in Tier 3 . The following components constitute the middleware:
[0034] 1. Object Relational Database: the Object-Relational database management system (ORDBMS) that is a general-purpose data management system that contains the ability to store relational data and other types of data. Although many of its functions could be managed purely be a relational database doing so would make for more complex application programs that access and use that data. In the diagram it will build databases of filters and screens because any person using the PRP will run a problem, decide on some changes and want to store the prior working assumptions in a database for reuse.
[0035] 2. The Reasoning Engine: the Reasoning Engine executes rules that impact both the Ontology and the data in the results database. It is likely to be part of the ORDBMS, but is shown separately just in case a more powerful reasoning system is required.
[0036] 3. PRP Application Server: the activities of the client user interfaces is coordinated by this application. It will interface with the ORDBMS to load screen and filters, and initiate the access to raw data and initiate the use of rule sets in order to generate results. This is the third part of the PRP: it generates a new, novel and useful measure that provides a useful new description of the information available that summarizes it concisely.
[0037] Tier 3
[0038] This is the data that is input to the system.
[0039] Refining Hypotheses is the term used describe the user's activity of interacting with the data as follows:
[0040] 1. The user come to the database with an initial hypothesis which he/she wants to validate using the data in the database.
[0041] 2. The user examines the data and comes up with a chain of reasoning, a set of steps during which the data in the database will be accessed, transformed, intermediate results created and finally a result generated.
[0042] 3. The results are examined and the process is repeated with either a reformulated hypothesis, a change in the scope and/or transformations of the data that is to be examined or both. The new results are examined.
[0043] 4. The process is repeated until the user is satisfied.
[0044] This interaction can be done with or without using the PRP. The PRP provides a more powerful way for the user to use the data available
[0045] We assume that the user is familiar with the specialized field of inquiry to which the data in the database is relevant. That means specifically that due to the user's personal training and experience he/she knows what types of hypotheses may be propounded and validated with the data. For purposes of illustration we assume that the user is processing data to assess data describing the current situation in which it is suspected their may be a threat to resources, e.g. business, medical, or military assets. The data in the database may admit to multiple interpretations. Each can be formulated as an initial decision hypothesis: as follows: : “the current situation X poses a threat to my resources Y at Z”. After the data is analyzed one of the following may be inferred:
[0046] 1. Contradiction: “the current situation X does not pose a threat to my resources Y at Z”
[0047] 2. Alternatives: “the current situation X poses a threat to my resources Y at W” OR “the current situation X poses a threat to my resources Y′ at Z”
[0048] 3. Ambiguity: “the current situation cannot be assessed with sufficient certainty to support any hypothesis”.
[0049] To use the data in the computer the hypothesis must be formulated in a specific manner. Because R. Reiter proved in 1984 that a query to a relational database was mathematically equivalent to a proof that the data supported a hypothesis the form of the hypothesis can be that of a query. The conversion from the verbal human statement to the computer format of the hypothesis is a two step process (the notation—backwards E means “there exists” and inverted A means “for all”):
[0050] 1. Expand the Meanings:
[0051] (∃(a,b,c . . . ) with relationships r 1 , r 2 , . . . )whenever situation X exists.
[0052] (∀(a,b,c . . . ) with relationships S 1 ,s 2 , . . . ) define the my resources Y.
[0053] The area Z is defined by criteria (A,B,C, . . . )
[0054] 2. Restate the verbal hypothesis as a query: “the evidence available in the database shows X, Y exist and Y meets criteria (A,B,C,. . . )”.
[0055] The word used in step 2 , however, was not “data” but “evidence”. Once the conversion is made, the evidence will either (1) support the assumptions of a decision hypothesis H 1 or (2) contradict it by supporting its contradiction H 1 C , or (3) not be relevant at all. Data is not necessarily evidence, and a method of relevance determination is provided to convert the stream of data to evidence. One of its actions is to defined exactly when redundant data is present. Such data need not be considered (eliminating redundant data solves the info-glut problem). This is one of the explicit PRP process steps, converting data to evidence by building screens. The useful advantage of this step potentially reduces the massive volume of data (also known as “infoglut”) and makes both the reasoning process and results more amenable to being effectively reviewed by a human.
[0056] Returning to the point about alternative hypotheses: whenever evidence is not relevant to one hypothesis about a situation it might be relevant to another. Thus this step of looking at alternative hypotheses can be applied to situations where multiple explanations for data are possible. A user may start out with one hypothesis, and monitor the situation, looking for new evidence that suggests that an initial hypothesis is now negated. This means that when the OPRP is used for monitoring it provides a useful advantage as all the plausible hypotheses by be compared against the evidence compared.
[0057] In FIG. 2 we see that Hypothesis 1 predicts two negative events and three positive ones, but has 4 events unaccounted for. The others have different coverage. Under the circumstances Hypothesis 2 is the best. The goal of the step in the PRP is to enable such a comparison.
[0058] The process steps are:
[0059] 1. Initialize problem space: specify
[0060] Decision: a hypothesis OR a set of hypotheses.
[0061] Data sources, objects, algorithms etc.
[0062] 2. Generate missing data
[0063] 3. Establish the Chain of Reasoning: data transformations needed to gather the data neededd to test the hypothesis or hypotheses.
[0064] 4. Set thresholds of uncertainty for valid data.
[0065] 5. Create screens to convert data to evidential objects.
[0066] 6. Run hypotheses verification & compare results.
[0067] 7. Adjust the abstraction level to encompass evidence.
[0068] 8. Potentially Perform Data Mining to improve results.
[0069] The first step is to state the subjective decision hypothesis or a set of competing hypotheses as a query. This means reformulating each hypotheses as a logical combination of one or more statements of the form:
[0070] “There exist objects whose properties {P i } have value ranges {R i }”
[0071] “All objects of type X have properties {P i } within value ranges {R i }.”
[0072] In logic these are the generalizations of statements containing “OR” conditions and “AND” conditions.
[0073] The second step is to use the Ontology editor to describe the
[0074] 1. Data Sources: form and constraints for all levels of available data inputs, and the
[0075] 2. Objects: complete description of all properties of objects that are detectable, of sensors, and abstract concepts (Ontology). This includes screen objects described below Further one should specify any additional
[0076] 3. algorithms, i.e. any new techniques embodied in programs that must be added to the PRP to enable filtering of data or eliminating uncertainty. This includes filter algorithms and thresholds described below.
[0077] These may be submitted also as input to the object relational database management system as needed.
[0078] Missing Data is generated after a subjective judgement by the PRP user. It may occur as an initial step, or during re-iteration of previous steps. Some sources
[0079] Projection of prior data about objects no longer visible,
[0080] Assumptions based on knowledge of enemy doctrine, or
[0081] Simulated data based on the data at hand.
[0082] Multiple hypotheses may reflect multiple guesses at the missing data and its values. This data will be necessary for making projections when not all of the area with possible data is observed.
[0083] Every data manipulation is the formal equivalent of reasoning step, so the total is called the Chain of Reasoning. The Chain of Reasoning is therefore the set of transformations from the raw data to the data used in the query based solely upon the meaning and form of the data. This is the set of steps that one uses to go from the data to the hypothesis. It is the data upon which the query representing that hypothesis is run. The Ontology will contain precise descriptions of all the data formats needed, and as needed these will be loaded into the ORDBMS.
[0084] [0084]FIG. 3 is a visualization of four sources of data that will be used to generate the Final View, data used to test the hypothesis. Source 1 is input to other data streams and is therefore some standard immutable description like a terrain map. Other processing steps combine or fuse data from the different sources to make intermediate data sets. The “F” symbol stand for filtering action described below.
[0085] The chain of reasoning must be constructed with the knowledge that not all of the data is equally valid. Whenever tests can be devised to eliminate data that is too questionable for use they will be incorporated as a filter. The filter admits some data and excludes other data. To use one, however, a threshold value must be set. That is the user's tolerance for data uncertainty. In the PRP this sub-process is explicit and may be reset to a different value if the hypotheses need to be looked at a later time with a different tolerance for uncertainty. Specifically, although traditional Pascalian Probability measures can be used, as well as Baconian Probability Measures, explained below, fuzzy measures can be used as well, these can take the form of explicit assignments of values, or the values may be inferred from the Pascalian and Baconian measures, a KEY feature of the PRP.
[0086] Baconian Probability is not as well known as Pascalian Probability, although de-facto it is the basis of scientific induction and is used extensively albeit informally. Let B(H) be the monadic (i.e. True of False) Baconian Probability of a hypothesis H and B(H,E) the dyadic conditional probability of H given E; then these are the formal mathematical properties [Schum, The Evidential Foundations of Probabilistic Reasoning, pp254-255]:
[0087] (1) Ordinal Property:
[0088] monadic case: B(H 1 )≧B(H 2 ) or B(H 2 )≧B(H 1 )
[0089] dyadic case: B(H 1 ,E 1 *)≧B(H 2 , E 2 *) or B(H 2 , E 2 *)≧B(H 1 ,E 1 *)
[0090] (2) Negation Property:
[0091] monadic case IF B(H)>0 then B(˜H)=0
[0092] dyadic case: IF B(H,E*)>0 then if B(˜E*)=0, then B(˜H,E*)=0
[0093] (3) Conjunction Rule:
[0094] monadic case: IF B(H 1 )≧B(H 2 ) THEN B(H 1 ◯H 2 )=B(H 2 )
[0095] dyadic case: IF B(H 1 ,E*)≧B(H 2 ,E*) THEN B(H 1 ◯H 2 ,E*)=B(H 2 ,E*)
[0096] (4) Disjunction Rule:
[0097] monadic case: IF B(H 1 )≧B(H 2 ) THEN B(H 1 ◯H 2 )=B(H 1 )
[0098] dyadic case: IF B(H 1 ,E*)≧B(H 2 ,E*) THEN B(H 1 ◯H 2 ,E*)=B(H 1 ,E*)
[0099] (5) Contraposition:
[0100] dyadic case: B(H,E*)=B(˜E*,˜H)
[0101] The system has been of great interest to the many people who have become aware of it, but heretofore no practitioners have seen a way to interpret it to be applicable to real-world situations. The PRP provides this assignment by a novel mechanism.
[0102] The Baconian probability associated with an object is determined by (1) the object observed, (2) the question asked of it and (3) the number of tests of values of relevant variables. The innovation is to applying the probability to all terms or slots of the Ontological description of the object, not just the static attributes. For example, a jeep may have 25 possible data values or properties that describe it, but only six of them are needed for identification. Let the hypothesis H be that object X is a jeep. Suppose the data contains 4 relations each of which of six variables, and together they encompass 12 terms of the 25, but also together they account for only 5 of the 6 identifying attributes. Then the Baconian probability of the (H)= 5 . This corresponds to the data passing five out of six possible Baconian existence tests on the different identifying property.
[0103] This process is totally new and is a major invention within the PRP. The problem is relevance of data and the value of having multiple instances of the “same” data. This must be addressed because future technology will enable better, more accurate, and more numerous data to be collected. The challenge is how then to use them without being overwhelmed? The step is the conversion of data to evidence.
[0104] The key step is to provide a precise description of the distinctions made in the discipline of Evidential Reasoning. Let H 1 be the decision hypothesis, and D 1 a datum that supports it. If D 1 supports a decision hypothesis H 1 does the next datum D 2 support the hypothesis more, less, the same? Is it relevant at all? In Evidential Reasoning the following definitions are provided:
[0105] Directly Relevant Data: data that is used to infer the decision hypothesis H.
[0106] Corroborating Data: data that strengthens the decision hypothesis H.
[0107] Redundant Data: data that duplicates what is already known about H.
[0108] Contradictory Data: data that supports the negation of H.
[0109] Conflicting Data: data either confirms or negates H i but does so for H j .
[0110] Using the PRP technology the user:
[0111] 1. enables the system to use relevant data as direct evidence,
[0112] 2. fuses corroborating data,
[0113] 3. screens out redundant data relevant to the competing hypotheses H j and their contradictions˜H j or H j C , and
[0114] 4. assigns conflicting data to the same process steps for competing hypotheses.
[0115] This is made possible by the use of the Ontology.
[0116] Hypothesis comparison requires defining the above terms precisely, and relating them to multiple hypothesis comparison. First the PRP user creates an Ontology for all objects {X 1 , . . . X M }, i.e. a complete logical description of the terms (a.k.a “slots) for each object i.e. properties (attributes), functions, relations and axioms. Let object X have terms (t 1 , t 2 , t 3 , . . . ) that may be any of the types of slots mentioned. A given object may be identifiable, however, by a subset of those terms, and there may be more than one such subset. For object X i let the subsets of identifying terms be IT i1 , IT i2 , IT i3 , . . . IT iM and let IT i be the set of these subsets. Note that if XT i is the set of all X i 's terms, and 2 XTi is its power set ,the set of all subsets, then the set of sets of identifying terms IT i ⊂ 2 XTi .
[0117] Then consider a set {d 0 , . . . d n } of data items that establish that an instance of object X i has been observed. The first one d 0 establishes that X i exists. This means that values for the instance of X i may be filled in for it's property values, function and relation values, and the designation that certain axioms have been shown to apply. Then the rest of the elements of the set d 1 . . . d n that also establish it are split into two subsets, the corroborating evidence {c 1 , . . . c n1 } and redundant evidence {r 1 , . . . r n2 }. The distinction is that dj is redundant unless it provides a value for a term that d 0 did not. Corroborating data is data that adds information about the object X i . Although it does not change the evidence that X i exists the new term values may be useful to subsequent queries that access the database. Otherwise, as they add no information, they are redundant. Formally:
[0118] Let d 1 and d 2 be relational data that consists of attributes (t 11 , t 12 , . . . t 1n ) and (t 21 , t 22 , . . . t 2m ) respectively.
[0119] Let d 1 directly identify object X i : it provides values for the subset of terms IT i1 , that is an element of IT i . Then d 2 is:
[0120] Redundant if it confirms the values of IT i1 ,
[0121] Corroborative is it confirms values using IT i2 ≠IT i1 ,
[0122] Contradictory if it does not have all the values of one of the IT i elements, and
[0123] Conflicting if it identifies elements IT j1 of another object X j at the same time and place as X i .
[0124] The above technique of identifying IT i is called creating and using a screen. One advantage is that it reduces the data glut to a manageable flow of information. It also separates out what data accrues to what decision hypothesis about the existence of an object. Sensor fusion is now also easy to define. Every sensor is modeled as an object as well with its own Ontology. There is a line of reasoning from the output of that sensor to terms in the Ontologies of the objects that it identifies. In IT 1 the infrared detector will see that the hood of a jeep is bright, meaning the jeep is operational. The logic of this association is stored in the Ontology. The fusion is done at the ontological level. The screen is now illustrated in detail in FIG. 4.
[0125] Continuing the example, a jeep may have an ontology entry yielding a set S of 25 properties, of which any of 4 subsets S 1 , S 2 , S 3 or S 4 of 6 properties might identify it (the IT ij 's). These are sensor-identification objects (SIO) (new!). Then if filtered data item d 1 identifies X 1 according to S 2 we have an identification object (IDO) (new!). The value d, becomes direct evidence of the existence of X 1 , and S 2 together with any additional sensed properties becomes the identification object (new process!). Then when data item d i is detected it is redundant if it uses S 2 and corroborative otherwise, say using S 3 , as is datum d 17 in FIG. 8. Adding this information updates the IDO. The IDO is the screen (new concept) with the properties in S 2 ◯S 4 together with all other properties of d 1 and d 17 . The screen eliminates infoglut because once enough observations are made to establish all 25 properties, then, as long as these values hold all additional data with the same values is redundant and not considered for decision making purposes: its not relevant. The IDO contains a binary array that tells which of the properties in the Ontology is present and which not by a 0/1 coding. This is used for probability filtering.
[0126] This is shown in FIG. 4. Evidence of the existence of an object and its lack of existence are both results of evidential reasoning. Evidence that exists but cannot be assigned to objects is unassigned. No hypothesis accounts for it. It can either be rejected as outlier data, or erroneous data or a new more expansive hypothesis can be generated that accounts for it.
[0127] The term of “abstraction” has been used in computer science in a number of sub-disciplines for some time. In this context it refers to the amount of detail that is provided for objects. A jeep categorized differently from other objects in that it is a vehicle that is (1) small, (2) motorized, (3) open, and is (4) all-wheel drive. The evidence may be insufficient to identify the jeep from a small convertible, but for purposes of supporting one or more the decision support hypotheses it may be sufficient to use only properties (1) and (2). In exact terms this means that a more abstract object, “small motorized vehicle” exists and a jeep is also an instance of it. The Ontology shows all such classes and allows queries to be made at any level of abstraction. If this is done, then more evidence may “come in from the cold” and be associated with the hypotheses with striking results, as shown in FIG. 4.
[0128] This is shown in FIG. 4. Evidence of the existence of an object and its lack of existence are both results of evidential reasoning. Evidence that exists but cannot be assigned to objects is unassigned. No hypothesis accounts for it. It can either be rejected as outlier data, or erroneous data or a new more expansive hypothesis can be generated that accounts for it.
[0129] The PRP also allows an alternative use of fuzzy logic. Whereas it is possible to assign a measure to a data that provides an ordinal scale mapping to values like “certainly, Probably, etc.” a novel technique of applying measures results in an exact abstraction with a name that incorporates the fuzziness. The evidence on hand is describes exactly, and the fuzziness is refected in the name of the object created—it is not as exact as one would wish to have, but it summarizes precisely what is known.
[0130] The term of “abstraction” has been used in computer science in a number of sub-disciplines for some time. In this context it refers to the amount of detail that is provided for objects. A jeep categorized differently from other objects in that it is a vehicle that is (1) small, (2) motorized, (3) open, and is (4) all-wheel drive. The evidence may be insufficient to identify the jeep from a small convertible, but for purposes of supporting one or more the decision support hypotheses it may be sufficient to use only properties (1) and (2). In exact terms this means that a more abstract object, “small motorized vehicle” exists and a jeep is also an instance of it. The Ontology shows all such classes and allows queries to be made at any level of abstraction. If this is done, then more evidence may “come in from the cold” and be associated with the hypotheses with striking results, as shown in FIG. 4.
[0131] Sensor data coming into the system is directly mappable to a set of DIDs—data ID arrays. Each sensor has its own particular types of data that it gathers in its spectrum, and some sensors may output interpretations of what has been observed. This means that there are a number of different types of attributes that can be found. Let the input be a X-coordinate, a Y-coordinate and three values V 1 through V 3 . These are then put in the “dimensional baskets”, as shown in FIG. 5.
[0132] The input needs then to be connected with the type of decision that must be made. The objects that may be present are represented in the Ontology. The Ontology provides ranges that the variables V 1 though V 3 may have and be consistent with the presence of the particular object that is being defined. This is shown for Object 1 of three possible objects in FIG. 6. This will result in three different ranges for the variables V 1 to V 3 depending on what object they identify (e.g. truck, jeep, tank). This means that the table of grouped data can be pivoted. In FIG. 7 we see it graphically.
[0133] This becomes a table upon which a clustering process of association (e.g. data mining) can proceed: groups of data values for different objects in the same 2,3 or 4-dimensional area will be compared to see to what objects they correspond. The value of this approach is that it works hand in glove with the abstraction technique. The pivoted table provides a summary of all of the input data, transformed into evidence. It is then possible to dynamically adjust the level of abstraction to take advantage of what data exists. However, even when inadequate data is present this can be useful.
[0134] The level of abstraction of data available “small vehicle” may lack sufficient detail, i.e. is it motorized or not to be useful directly. However, the filtering mechanism may be invoked here as well. The filter would normally exclude a piece of evidence for a small vehicle for being considered a jeep or a car if it only had two out of four identifications. On the other hand, the user could have a hypothesis of a “worst case” scenario and assume that all of the “small vehicles” were jeeps just to see what threat would be possible in this case. This could be compared to the traditional approach where an object is not part of a threat until it is identified as one.
[0135] The system must allow the PRP user to change parameters for uncertainty via filters and for the objects to be fused via Ontology entries. Summarized, the requirements of such a system are that the user must be able to specify (1) a set of data sources, or a process such as a search engine query that supplies them. For each data source the user must specify (2) the processing filter to be used to include or omit the data. Each filter consists of transformations, including (3) the user supplied parameters for screening out any data with too high an uncertainty. The filter at the final data level should include (4) the last (higher) level of detail at which information is to be processed and (5) how frequently the data is to be updated. In addition the user must specify (5) the Final View's filter for combining the final sources of data. This section discusses the fusion of data using objects and the application of Evidential Reasoning, the use of an Ontology and screens. The PRP results are displayed to the user and changes like the above are made to explore the possible interpretations of the evidence.
[0136] The various embodiments and modifications of the present invention are not just those which have been heretofore described, but also all those within the scope of the following claim.
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The distinguishing feature of the present invention is that it provides a means to answer a query about a database when the data in the database is not complete or is not considered to be trustworthy. The adverb Platonic is used to describe the reasoning process because of Plato's metaphorical description of how human beings perceive reality. The metaphor was one of a fire in a cave. Plato said that human beings cannot perceive objects in the real world in their exact form. If an object were in a cave, a fire in the cave would cast a shadow of that object on the wall. That shadow, however, would alter shape and the edges would appear to flicker. A person in that cave facing the wall would not be able to see the true form of the object, only the shadows. However, by looking at those shadows it would be possible to get a good approximation of the shape of the actual object. That is the intent of the present invention, to process the data as so as to obtain a good approximation of the object in the real world that the data represents.
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This is a continuation of application Ser. No. 563,737, filed Mar. 31, 1975, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to novel compositions of matter, to novel methods for producing said compositions, and to novel chemical intermediates useful in those processes. Particularly, this invention relates to certain novel analogs of some of the known prostaglandins which differ from the known prostaglandin in that they are substituted at C-16 with a phenoxy or substituted phenoxy, and have a lower alkyl group in place of the hydrogen at C-15 and/or a lower alkoxy group in place of the hydroxy at C-15. The known prostaglandins (PG's) include, for example, prostaglandin E 1 (PGE 1 ), prostaglandin E 2 (PGE 2 ), dihydroprostaglandin E 1 (dihydro-PGE 1 ), prostaglandin F 1 α (PGF 1 α), prostaglandin F 2 α (PGF 2 α), dihydroprostaglandin F 1 α (dihydro-PGF 1 α), prostaglandin F 1 β (PGF 1 β), dihydroprostaglandin F 1 β (dihydro-PGF 1 β), prostaglandin A 1 , (PGA 1 ), prostaglandin A 2 (PGA 2 ), dihydroprostaglandin A 1 (dihydro-PGA 1 ), prostaglandin B 1 (PGB 1 ), prostaglandin B 2 (PGB 2 ), and dihydroprostaglandin B 1 (dihydro-PGB 1 ). Each of the above-mentioned known prostaglandins is a derivative of prostanoic acid which has the following structure and carbon atom numbering: ##STR1## See, for example, Bergstrom et al., Pharmacol. Rev. 20, 1 (1968), and references cited therein. A systematic name for prostanoic acid is 7-[(2β-octyl)-cyclopent-1α-yl]heptanoic acid. ##STR2##
In the above formulas, as well as in the formulas hereinafter given, broken line attachments to the cyclopentane ring indicate substituents in alpha configuration i.e., below the plane of the cyclopentane ring. Heavy solid line attachments to the cyclopentane ring indicate substituents in beta configuration, i.e., above the plane of the cyclopentane ring.
The side-chain hydroxy at C-15 in the above formulas is in S configuration. See, Nature, 212, 38 (1966) for discussion of the stereochemistry of the prostaglandins. Expressions such as C-15, and the like, refer to the carbon atom in the prostaglandin or prostaglandin analog which is in the position corresponding to the position of the same number in prostanoic acid.
Molecules of the known prostaglandins each have several centers of asymmetry, and can exist in racemic (optically inactive) form and in either of the two enantiomeric (optically active) forms, i.e., the dextrorotatory and levorotatory forms. As drawn, the above formulas each represent the particular optically active form of the prostaglandin which is obtained from certain mammalian tissues, for example, sheep vesicular glands, swine lung, or human seminal plasma, or by carbonyl and/or double bond reduction of that prostaglandin. See, for example, Bergstrom et al., cited above. The mirror image of each of these formulas represents the other enantiomer of that prostaglandin. The racemic form of a prostaglandin contains equal numbers of both enantiomeric molecules, and one of the above formulas and the mirror image of that formula is needed to represent correctly the corresponding racemic prostaglandin. For convenience hereinafter, use of the terms, PGE 1 , PGE 2 , and the like, refer to the optically active form of that prostaglandin with the same absolute configuration as PGE 1 obtained from mammalian tissues. When reference to the racemic form of one of those prostaglandins is intended, the word "racemic" or "dl" will procede the prostaglandin name.
PGE 1 , PGE 2 , dihydro-PGE 1 , PGF 1 α, PGF 2 α, dihydro-PGF 1 α, PGF 1 β, PGF 2 β, dihydro-PGF 1 β, PGA 1 , PGA 2 , dihydro-PGA 1 , PGB 1 , PGB 2 , dihydro-PGB 1 , and their esters, acylates and pharmacologically acceptable salts, are extremely potent in causing various biological responses. For that reason, these compounds are useful for pharmacological purposes. See, for example, Bergstrom et al., Pharmacol. Rev. 20, 1 (1968) and references cited therein. A few of those biological responses are systemic blood pressure lowering in the case of the PGE and PGA compounds as measured, for example, in anesthetized (pentobarbital sodium) per olinium-treated rats with indwelling aortic and right heart cannulas; stimulation of smooth muscle as shown, for example, by tests on strips on guinea pig ileum, rabbit duodenum, or gerbil colon; potentiation of other smooth muscle stimulants; lipolytic activity as shown by antagonism of epinephrine-induced mobilization of free fatty acids or inhibition of the spontaneous release of glycerol from isolated rat fat pads; inhibition of gastric secretion in the case of the PGE and PGA compounds as shown in dogs with secretion stimulated by food or histamine infusion; activity on the central nervous system; controlling spasm and facilitating breathing in asthmatic conditions; decreasing blood platelet adhesiveness as shown by platelet-to-glass adhesiveness, and inhibition of blood platelet aggregation and thrombus formation induced by various physical stimuli, e.g., arterial injury, and various biochemical stimuli, e.g., ADP, ATP, serotonin, thrombin, and collagen; and in the case of the PGE and PGB compounds, stimulation of epidermal proliferation and keratinization as shown when applied in culture to embryonic chick and rat skin segments. Because of these biological responses, these known prostaglandins are useful to study, prevent, control, or alleviate a wide variety of diseases and undesirable physiological conditions in birds and mammals, including humans, useful domestic animals, pets, and zoological specimens, and in laboratory animals, for example, mice, rats, rabbits, and monkeys.
For example, these compounds and especially the PGE compounds, are useful in mammals, including man, as nasal decongestants. For this purpose, the compounds are used in a dose range of about 10 μg. to about 10 mg. per ml. of a pharmacologically suitable liquid vehicle or as an aerosol spray, both for topical application.
The PGE, PGF.sub.β, and PGA compounds are useful in the treatment of asthma. For example, these compounds are useful as bronchodilators or as inhibitors of mediators, such as SRS-A, and histamine which are released from cells activated by an antigen-antibody complex. Thus, these compounds control spasm and facilitate breathing in conditions such as bronchial asthma, bronchitis, bronchiectasis, pneumonia and emphysema. For these purposes, these compounds are administered in a variety of dosage forms, e.g., orally in the form of tablets, capsules, or liquids; rectally in the form of suppositories; parenterally, subcutaneously, or intramuscularly, with intravenous administration being preferred in emergency situations; by inhalation in the form of aerosols or solutions for nebulizers; or by insufflation in the form of powder. Doses in the range of about 0.01 to 5 mg. per kg. of body weight are used 1 to 4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. For the above use these prostaglandins can be combined advantageously with other anti-asthmatic agents, such as sympathomimetics (isoproterenol, phenylephrine, epinephrine, etc.); xanthine derivatives (theophylline and aminophylline); and corticosteroids (ACTH and predinisolone). Regarding use of these compounds see M. E. Rosenthale, et al., U.S. Pat. No. 3,644,638.
The PGE and PGA compounds are useful in mammals, including man and certain useful animals, e.g., dogs and pigs, to reduce and control excessive gastric secretion, thereby reducing or avoiding gastrointestinal ulcer formation, and accelerating the healing of such ulcers already present in the gastrointestinal tract. For this purpose, the compounds are injected or infused intravenously, subcutaneously, or intramuscularly in an infusion dose range about 0.1 μg. to about 500 μg. per kg. of body weight per minute, or in a total daily dose by injection or infusion in the range about 0.1 to about 20 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful whenever it is desired to inhibit platelet aggregation, to reduce the adhesive character of platelets, and to remove or prevent the formation of thrombi in mammals, including man, rabbits, and rats. For example, these compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent post-operative thrombosis, to promote patency of vascular grafts following surgery, and to treat conditions such as atherosclerosis, arteriosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia. For these purposes, these compounds are administered systemically, e.g., intravenously subcutaneously, intramuscularly, and in the form of sterile implants for prolonged action. For rapid response, especially in emergency situations, the intravenous route of administration is preferred. Doses in the range about 0.005 to about 20 mg. per kg. of body weight per day are used, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The PGE, PGF.sub.α, and PGF.sub.β compounds are especially useful as additives to blood, blood products, blood substitutes, and other fluids which are used in artificial extracorporeal circulation and perfusion of isolated body portions, e.g., limbs and organs, whether attached to the original body, detached and being preserved or prepared for transplant, or attached to a new body. During these circulations and perfusions, aggregated platelets tend to block the blood vessels and portions of the circulation apparatus. This blocking is avoided by the presence of these compounds. For this purpose, the compound is added gradually or in single or multiple portions to the circulating blood, to the blood of the donor animal, to the perfused body portion, attached or detached, to the recipient, or to two or all of those at a total steady state dose of about 0.001 to 10 mg. per liter of circulating fluid. It is especially useful to use these compounds in laboratory animals, e.g., cats, dogs, rabbits, monkeys, and rats, for these purposes in order to develop new methods and techniques for organ and limb transplants.
PGE compounds are extremely potent in causing stimulation of smooth muscle, and are also highly active in potentiating other known smooth muscle stimulators, for example, oxytocic agents, e.g., oxytocin, and the various ergot alkaloids including derivatives and analogs thereof. Therefore, a PGE compound, for example, is useful in place of or in combination with less than usual amounts of these known smooth muscle stimulators, for example, to relieve the symptoms of paralytic ileus, or to control or prevent atonic uterine bleeding after abortion or delivery, to aid in expulsion of the placenta, and during the puerperium. For the latter purpose, the PGE compound is administered by intravenous infusion immediately after abortion or delivery at a dose in the range about 0.01 to about 50 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, subcutaneous, or intramuscular injection or infusion during puerperium in the range 0.01 to 2 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal.
The PGE and PGA compounds are useful as hypotensive agents to reduce blood pressure in mammals, including man. For this purpose, the compounds are administered by intravenous infusion at the rate about 0.01 to about 50 μg. per kg. of body weight per minute or in single or multiple doses of about 25 to 500 μg. per kg. of body weight total per day.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful in place of oxytocin to induce labor in pregnant female animals, including man, cows, sheep, and pigs, at or near term, or in pregnant animals with intrauterine death of the fetus from about 20 weeks to term. For this purpose, the compound is infused intravenously at a dose of 0.01 to 50 μg. per kg. of body weight per minute until or near the termination of the second stage of labor, i.e., expulsion of the fetus. These compounds are especially useful when the female is one or more weeks post-mature and natural labor has not started, or 12 to 60 hours after the membranes have ruptured and natural labor has not yet started. An alternative route of administration is oral.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful for controlling the reproductive cycle in ovulating female mammals, including humans and animals such as monkeys, rats, rabbits, dogs, cattle, and the like. By the term ovulating female mammals is meant animals which are mature enough to ovulate but no so old that regular ovulation has ceased. For that purpose the PG compound, is administered systemically at a dose level in the range 0.01 mg. to about 20 mg. per kg. of body weight of the female mammal, advantageously during a span of time starting approximately at the time of ovulation and ending approximately at the time of menses or just prior to menses. Intravaginal and intrauterine are alternative routes of administration. Additionally, expulsion of an embryo or a fetus is accomplished by similar administration of the compound during the first or second trimester of the normal mammalian gestation period.
The PGE and PGF compounds are useful in causing cervical dilation in pregnant and nonpregnant female mammals for purposes of gynecology and obstetrics. In labor induction and in clinical abortion produced by these compounds, cervical dilation is also observed. In cases of infertility, cervical dilation produced by PGE and PGF compounds is useful in assisting sperm movement to the uterus. Cervical dilation by prostaglandins is also useful in operative gynecology such as D and C (Cervical Dilation and Uterine Curettage) where mechanical dilation may cause perforation of the uterus, cervical tears, or infections. It is also useful in diagnostic procedures where dilation is necessary for tissue examination. For these purposes, the PGE and PGF compounds are administered locally or systemically.
PGE 2 , for example, is administered orally or vaginally at doses of about 5 to 50 mg. per treatment of an adult female human, with from one to five treatments per 24 hour period. PGE 2 is also administered intramuscularly or subcutaneously at doses of about one to 25 mg. per treatment. The exact dosages for these purposes depend on the age, weight, and condition of the patient or animal.
As mentioned above, the PGE compounds are potent antagonists of epinephrine-induced mobilization of free fatty acids. For this reason, this compound is useful in experimental medicine for both in vitro and in vivo studies in mammals, including man, rabbits, and rats, intended to lead to the understanding, prevention, symptom alleviation, and cure of diseases involving abnormal lipid mobilization and high free fatty acid levels, e.g., diabetes mellitus, vascular diseases, and hyperthyroidism.
The PGA compounds and derivatives and salts thereof increase the flow of blood in the mammalian kidney, thereby increasing volume and electrolyte content of the urine. For that reason, PGA compounds are useful in managing cases of renal dysfunction, especially those involving blockage of the renal vascular bed. Illustratively, the PGA compounds are useful to alleviate and correct cases of edema resulting, for example, from massive surface burns, and in the management of shock. For these purposes, the PGA compounds are preferably first administered by intravenous injection at a dose in the range 10 to 1000 μg. per kg. of body weight or by intravenous infusion at a dose in the range of 0.1 to 20 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, intramuscular, or subcutaneous injection or infusion in the range 0.05 to 2 mg. per kg. of body weight per day.
The PGE and PGB compounds promote and accelerate the growth of epidermal cells and keratin in animals, including humans, useful domestic animals, pets, zoological specimens, and laboratory animals. For that reason, these compounds are useful to promote and accelerate healing of skin which has been damaged, for example, by burns, wounds, and abrasions, and after surgery. These compounds are also useful to promote and accelerate adherence and growth of skin autografts, especially small, deep (Davis) grafts which are intended to cover skinless areas by subsequent outward growth rather than initially, and to retard rejection of homografts.
For these purposes, these compounds are preferably administered topically at or near the site where cell growth and keratin formation is desired, advantageously as an aerosol liquid or micronized powder spray, as an isotonic aqueous solution in the case of wet dressings, or as a lotion, cream, or ointment in combination with the usual pharmaceutically acceptable diluents. In some instances, for example, when there is substantial fluid loss as in the case of extensive burns or skin loss due to other causes, systemic administration is advantageous, for example, by intravenous injection or infusion, separate or in combination with the usual infusions of blood, plasma, or substitutes thereof. Alternative routes of administration are subcutaneous or intramuscular near the site, oral, sublingual, buccal, rectal, or vaginal. The exact dose depends on such factors as the route of administration, and the age, weight, and condition of the subject. To illustrate, a wet dressing for topical application to second and/or third degree burns of skin area 5 to 25 square centimeters would advantageously involve use of an isotonic aqueous solution containing 1 to 500 μg/ml. of the PGB compound or 1 to 500 μg/ml. of the PGE compound. Especially for topical use, these prostaglandins are useful in combination with antibiotics, for example, gentamycin, neomycin, polymixin B, bacitracin, spectinomycin, and oxytetracycline, with other antibacterials, for example, mafenide hydrochloride, sulfadiazine, furazolium chloride, and nitrofurazone, and with corticoid steroids, for example, hydrocortisone, prednisolone, methylprednisolone, and fluprednisolone, each of those being used in the combination at the usual concentration suitable for its use alone.
The PGE, PGF.sub.α, PGF.sub.β, PGA and PGB compounds are also useful in reducing the undesirable gastrointestinal effects resulting from systemic administration of anti-inflammatory prostaglandin synthetase inhibitors, and are used for that purpose by concomitant administration of the prostaglandin and the anti-inflammatory prostaglandin synthetase inhibitor. See Partridge et al., U.S. Pat. No. 3,781,429, for a disclosure that the ulcerogenic effect induced by certain non-steroidal anti-inflammatory agents in rats is inhibited by concomitant oral administration of certain prostaglandins of the E and A series, including PGE 1 , PGE 2 , PGE 3 , 13,14dihydro-PGE 1 , and the corresponding 11-deoxy-PGE and PGA compounds. Prostaglandins are known useful in reducing the undersirable gastrointestinal effects resulting from systemic administration of indomethacin, phenylbutazone, and aspirin. These latter substances are specifically mentioned in Partridge et al. as non-steroidal anti-inflammatory agents. But these are also known to be prostaglandin synthetase inhibitors.
The anti-inflammatory synthetase inhibitor, for example, indomethacin, aspirin, or phenylbutazone is administered in any of the ways known in the art to alleviate an inflammatory condition, for example, in any dosage regimen and by any of the known routes of systemic administration.
The prostaglandin is administered along with the anti-inflammatory prostaglandin synthetase inhibitor either by the same route of administration or by a different route. For example, if the anti-inflammatory substance is being administered orally, the prostaglandin is also administered orally or, alternatively, is administered rectally in the form of a suppository or, in the case of women, vaginally in the form of a suppository or a vaginal device for slow release, for example as described in U.S. Pat. No. 3,545,439. Alternatively, if the anti-inflammatory substance is being administered rectally, the prostaglandin is also administered rectally, or, alternatively, orally or, in the case of women, vaginally. It is especially convenient when the administration route is to be the same for both anti-inflammatory substance and prostaglandin, to combine both into a single dosage form.
The dosage regimen for the prostaglandin in accord with this treatment will depend upon a variety of factors including the type, age, weight, sex and medical condition of the mammal, the nature and dosage regimen of the anti-inflammatory synthetase inhibitor being administered to the mammal, the sensitivity of the particular individual mammal to the particular synthetase inhibitor with regard to gastointestinal effects, and the particular prostaglandin to be administered. For example, not every human in need of an anti-inflammatory substance experiences the same adverse gastrointestinal effects when taking the substance. The gastrointestinal effects will frequently vary substantially in kind and degree. But it is within the skill of the attending physician or veterinarian to determine that administration of the anti-inflammatory substance is causing undesirable gastrointestinal effects in the human or animal subject and to prescribe an effective amount of the prostaglandin to reduce and then substantially to eliminate those undesirable effects.
Several compounds related to the novel compounds of this invention are known in the art.
See, for example, Netherlands Pat. No. 7,206,361, Derwent Farmdoc CPI No. 76383T-B, or Netherlands Pat. No. 7,306,462, Derwent Farmdoc CPI No. 73279U-B.
SUMMARY OF THE INVENTION
This invention provides novel prostaglandin analogs, esters of said analogs, lower alkanoates of said analogs and pharmacologically acceptable salts of said analogs.
This invention further provides novel intermediates useful in producing these compounds. This invention further provides novel processes for preparing these compounds.
The prostaglandin analogs of this invention can be represented by the formulas: ##STR3## wherein R 1 is hydrogen alkyl of one to 12 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, phenyl substituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive, ##STR4## or a pharmacologically acceptable cation;
wherein T is alkyl of one to 3 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or --OR 2 wherein R 2 is alkyl of one to 3 carbon atoms, inclusive, and wherein s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl, the T's being the same or different;
wherein R 4 and R 5 are hydrogen or alkyl of one to two carbon atoms, inclusive, being the same or different;
wherein M 3 ##STR5## wherein R 7 and R 8 are hydrogen or alkyl of 1 to 2 carbon atoms, inclusive, being the same or different, with the proviso that at least one of R 7 or R 8 must be alkyl of 1 to 2 carbon atoms, inclusive;
wherein g is 3 to 5, inclusive; and
wherein ˜ indicates the attachment of hydroxy to the cyclopentane ring in either the alpha or beta configuration.
Examples of alkyl of one to 12 carbon atoms, inclusive, are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and isomeric forms thereof.
Examples of cycloalkyl of 3 to 10 carbon atoms, inclusive, which includes alkyl-substituted cycloalkyl, are cyclopropyl, 2-methylcyclopropyl, 2,2-dimethylcyclopropyl, 2,3-diethylcyclopropyl, 2-butylcyclopropyl, cyclobutyl, 2-methylcyclobutyl, 3-propylcyclobutyl, 2,3,4-triethylcyclobutyl, cyclopentyl, 2,2-dimethylcyclopentyl, 2-pentylcyclopentyl, 3-tert-butylcyclopentyl, cyclohexyl, 4-tert-butylcyclohexyl, 3-isopropylcyclohexyl , 2,2-dimethylcyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl.
Examples of aralkyl of 7 to 12 carbon atoms, inclusive, are benzyl, phenethyl, 1-phenylethyl, 2-phenylpropyl, 4-phenylbutyl, 3-phenylbutyl, 2-(1-naphthylethyl), and 1-(2-naphthylmethyl). Examples of phenyl substituted by one to 3 chloro or alkyl of one to 4 carbon atoms, inclusive, are p-chlorophenyl, m-chlorophenyl, o-chlorophenyl, 2,4-dichlorophenyl, 2,4,6-trichlorophenyl, p-tolyl, m-tolyl, o-tolyl, p-ethylphenyl, p-tert-butylphenyl, 2,5-dimethylphenyl, 4-chloro-2-methylphenyl, and 2,4-dichloro-3-methylphenyl.
Examples of ##STR6## wherein T is alkyl of one to 3 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or --OR 2 wherein R 2 is alkyl of one to 3 carbon atoms, inclusive; and s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl, are phenyl, (o-, m-, or p-)tolyl, (o-, m-, or p-)ethylphenyl, 2-ethyl-p-tolyl, 4-ethyl-o-tolyl, 5-ethyl-m-tolyl, (o-, m-, or p-)propylphenyl, 2-propyl-(o-, m-, p-)tolyl, 4-isopropyl-2,6-xylyl, 3-propyl-4-ethylphenyl, (2,3,4-, 2,3,5-, 2,3,6-, or 2,4,5-)trimethylphenyl, (o-, m-, or p-)fluorophenyl, 2-fluoro-(o-, m-, or p-)tolyl, 4-fluoro-2,5-xylyl, (2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)difluorophenyl, (o-, m-, or p-)chlorophenyl, 2chloro-p-tolyl, (3-, 4-, 5-, or 6-)chloro-o-tolyl, 4-chloro-2-propylphenyl, 2-iosopropyl-4-chlorophenyl, 4-chloro-3,5-xylyl, (2,3-, 2,4-, 2,5-, 2,6- 3,4-, or 3,5-)dichlorophenyl, 4-chloro-3-fluorophenyl, (3-, or 4-)chloro-2-fluorophenyl, (o-, m-, p-)trifluoromethylphenyl, (o-, m-, or p-)methoxyphenyl, (o-, m-, or p-)ethoxyphenyl, (4- or 5-)chloro-2-methoxyphenyl, and 2,4-dichloro-(5- or 6-)methoxyphenyl.
Examples of the compounds within the scope of this invention are: 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α, a compound according to Formula I wherein ˜ is alpha, g is 3, R 1 is hydrogen, M 3 is ##STR7## R 4 and R 5 are hydrogen and s is zero; 2a,2b-dihomo-15-epi-15-methyl-16-phenoxy-17,18,19,20-tetranor-PGE 1 , methyl ester, 15-methyl ether, a compound according to formula VI wherein g is 5, or R 1 is methyl, M 3 is ##STR8## R 4 and R 5 are hydrogen and s is 0; 13,14-dihydro-16-methyl, 16-(m-trifluoromethylphenoxy)-18,19,20-trinor-PGA 1 , 15-methyl ether, a compound according to formula XII wherein g is 3, R 1 is hydrogen, M 3 is ##STR9## R 4 and R 5 are both methyl, and (T) s is m-trifluoromethyl.
In the name of the novel prostaglandin analogs of this invention, "2a-homo" or "2a,2b-dihomo" indicates that one or two additional carbon atoms, respectively, have been inserted in the carboxy terminated side chain, specifically between the C-2 and C-3 carbon atoms. There are then 8 or 9 carbon atoms in that side chain instead of the normal 7 in the prostanoic acid structure. From the end of the side chain they are identified as C-1, C-2, C-2a, C-2b, C-3, C-4, and C-5, and so on.
Also included in the compounds of this invention are the 15-alkyl prostaglandin analogs, for example 15-methyl and 15-ethyl. In naming these analogs "15-methyl" or "15-ethyl" is used when the hydrogen at position C-15 of the parent prostaglandins is replaced by a methyl or ethyl group, respectively.
Further included in the compounds of this invention are the 15-alkyl ethers, wherein R 8 is alkyl. For example, both 15-methyl ethers and 15-ethyl ethers are provided in this invention.
Also included within this invention are 15-epimeric compounds wherein M 3 is ##STR10## and the C-15 hydroxy or alkoxy is in the β configuration. Hereinafter "15-epi" refers to the epimeric configuration.
In naming the compounds of this invention, "18,19,20-trinor" indicates the absence of 3 carbon atoms from the hydroxy-terminated side chain of the parent prostaglandins. Following the carbon atom numbering of the prostanoic acid structure, C-18, C-19, and C-20 are construed as missing, and the methylene at C-17 is replaced with the terminal methyl group. Likewise, 17,18,19,20-tetranor indicates the absence of the C-17, C-18, C-19 and C-20 carbon atoms from the methyl-terminated side chain. In this system of nomenclature the word "trinor" or "tetranor" in the name of the prostaglandin analog is construed as indicating 3 or 4 carbon atoms, respectively, are missing from the C-17 to C-20 position of the prostanoic acid carbon skeleton.
Accordingly there is provided a compound of the formula ##STR11## or a mixture comprising that compound and the enantiomer thereof, wherein (a) X is trans--CH═CH-- or --CH 2 CH 2 -- and Y is --CH 2 CH 2 -- or (b) X is trans--CH═CH-- and Y is cis--CH═CH--;
wherein D is one of the four carbocyclic moieties: ##STR12## wherein ˜ indicates attachment of hydroxyl to the ring in the alpha or beta configuration; and
wherein g, M 3 , R 1 , R 4 , R 5 , T, and s are as defined above.
The preceding formula, which is written in generic form for convenience, represents PGE-thype compounds when D is ##STR13##
The novel compounds of this invention each cause the biological responses described above the the PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB compounds, respectively, and each of these novel compounds is accordingly useful for the above-described corresponding purposes, and is used for those purposes in the same manner as described above.
The known PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB compounds are all potent in causing multiple biological responses even at low doses. For example, PGE 1 and PGE 2 both cause vasodepression and smooth muscle stimulation at the same time they exert antilipolytic activity. Moreover, for many applications, these known prostaglandins have an inconveniently short duration of biological activity. In striking contrast, the novel prostaglandin analogs of this invention are substantially more selective with regard to potency in causing prostaglandin-like biological responses, and have a substantially longer duration of biological activity. Therefore, each of these novel prostaglandin analogs is surprisingly and unexpectedly more useful than one of the corresponding above-mentioned known prostaglandins for at least one of the pharmacological purposes indicated above for the latter, because it has a different and narrower spectrum of biological potency than the known prostaglandin, and therefore is more specific in its activity and causes smaller and fewer undesired side effects than when the known prostaglandin is used for the same purpose. Moreover, because of its prolonged activity, fewer and smaller doses of the novel prostaglandin analog can frequently be used to attain the desired result.
Another advantage of the novel compounds of this invention, especially the preferred compounds defined herein below, compared with the known prostaglandins, is that these novel compounds are administered effectively orally, sublingually, intravaginaly, buccally, or rectally, in addition to usual intravenous, intramuscular, or subcutaneous injection or infusion methods indicated above for the uses of the known prostaglandins. These qualities are advantageous because they facilitate maintaining uniform levels of these compounds in the body with fewer, shorter, or smaller doses, and make possible self-administration by the patient.
As discussed above, the novel compounds of this invention are administered in various ways for various purposes: e.g., intravenously, intramuscularly, subcutaneously, orally, intravaginally, rectally, buccally, sublingually, topically, and in the form of sterile implants for prolonged action. For intravenous injection or infusion, sterile aqueous isotonic solutions are preferred. For that purpose, it is preferred because of increased water solubility that R 1 in the novel compounds of this invention by hydrogen or a pharmacologically acceptable cation. For subcutaneous or intramuscular injection, sterile solutions or suspensions of the acid, salt, or ester form in aqueous or non-aqueous media are used. Tablets, capsules, and liquid preparations such as syrups, elixirs, and simple solutions, with the usual pharmaceutical carriers are used for oral sublingual administration. For rectal or vaginal administration, suppositories prepared as known in the art are used. For tissue implants, a sterile tablet or silicone rubber capsule or other object containing or impregnated with the substance is used.
The novel prostaglandin analogs of this invention including their alkanoates, are used for the purposes described above in the free acid form, in ester form, in pharmacologically acceptable salt form. When the ester form is used, the ester is any of those within the above definition of R 1 . However, it is preferred that the ester be alkyl of one to 12 carbon atoms, inclusive. Of the alkyl esters, methyl and ethyl are especially preferred for optimum absorption of the compound by the body or experimental animal system; and straight-chain octyl, nonyl, decyl, undecyl, and dodecyl are especially preferred for prolonged activity in the body or experimental animal. When R 1 is not alkyl it is especially preferred that R 1 be one of the esters of the group represented by: ##STR14##
Pharmacologically acceptable salts of the novel prostaglandin analogs of this invention, compounds useful for the purposes described above are those with pharmacologically acceptable metal cations, ammonium, amine cations, or quaternary ammonium cations.
Especially preferred metal cations are those derived from the alkali metals, e.g., lithium, sodium, and potassium, and from the alkaline earth metals, e.g., magnesium and calcium, although cationic forms of other metals, e.g., aluminum, zinc, and iron are within the scope of this invention.
Pharmacologically acceptable amine cations are those derived from primary, secondary, or tertiary amines. Examples of suitable amines are methylamine, dimethylamine, trimethylamine, ethylamine, dibutylamine, triisopropylamine, N-methylhexylamine, decylamine, dodecylamine, allylamine, crotylamine, cyclopentylamine, dicyclohexylamine, benzylamine, dibenzylamine, α-phenylethylamine, β-phenylethylamine, ethylenediamine, diethylenetriamine, and the like aliphatic, cycloaliphatic, araliphatic amines containing up to and including about 18 carbon atoms, as well as heterocyclic amines, e.g., piperidine, morpholine, pyrrolidine, piperazine, and lower-alkyl derivatives thereof, e.g., 1-methylpiperidine, 4-ethylmorpholine, 1-isopropylpyrrolidine, 2-methylpyrrolidine, 1,4-dimethylpiperazine, 2-methylpiperidine, and the like, as well as amines containing water-solubilizing or hydrophilic groups, e.g., mono-, di-, and triethanolamine, ethyldiethanolamine, N-butylethanolamine, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, tris(hydroxymethyl)aminomethane, N-phenylethanolamine, N-(p-tert-amylphenyl)diethanolamine, galactamine, N-methylgycamine, N-methylglucosamine, ephedrine, phenylephrine, epinephrine, procaine, and the like.
Examples of suitable pharmacologically acceptable quaternary ammonium cations are tetramethylammonium, tetraethylammonium, benzyltrimethylammonium, phenyltriethylammonium, and the like.
The novel PG analogs of this invention are used for the purposes described above in free hydroxy form or also in the form wherein the hydroxy moieties are transformed to lower alkanoate moieties, e.g., --OH to --OCOCH 3 . Examples of lower alkanoate moieties are acetoxy, propionyloxy, butyryloxy, valeryloxy, hexanoyloxy, heptanoyloxy, octanoyloxy, and branched chain alkanoyloxy isomers of those moieties. Especially preferred among these alkanoates for the above described purposes are the acetoxy compounds. These free hydroxy and alkanoyloxy compounds are used as free acids, as esters, and in salt form all as described above.
To obtain the optimum combination of biological response specificity, potency, and duration of activity, certain compounds within the scope of this invention are preferred.
Of the novel compounds of this invention, it is preferred that R 4 and R 5 be the same, both being either methyl or hydrogen. It is especially preferred that R 4 and R 5 both be hydrogen.
It is further preferred that g be either 3 or 5; that is, that the carboxy terminated side chain has either 7 or 9 carbon atoms, respectively. It is especially preferred that the carboxy terminated side chain have 7 carbon atoms that is, that g be 3. It is also preferred that only one of R 7 or R 8 be methyl and that the other of R 7 or R 8 be hydrogen.
It is further preferred that with respect to (T) s that s be zero or one and that when s is one T be trifluoromethyl, fluoro, or chloro.
The novel 16-phenoxy- or substituted phenoxy-PGE-, PGF.sub.α -, PGF.sub.β -, PGA-, and PGB analogs of this invention are produced by the reactions and procedures described and exemplified hereinafter.
Reference to Charts A and B herein, will make clear the steps for preparing the certain prostaglandin-type intermediates useful in the preparation of the novel prostaglandin analogs of this invention.
Previously, the preparation of an intermediate bicyclic lactone diol of the formula ##STR15## was reported by E. J. Corey et al., J. Am. Chem. Soc. 91, 5675 (1969), and later disclosed in an optically active form by E. J. Corey et al., J. Am. Chem. Soc. 92, 397 (1970). Conversion of this intermediate to PGE 2 and PGF 2 α, either in racemic or optically active form, was disclosed in those publications. ##STR16##
The iodolactone of formula XIII of Chart A is known in the art (see Corey et al., above). It is available in either racemic or optically active (+ or -) form. For racemic products, the racemic form is used. For prostaglandins of natural configuration, the laevorotatory form (-) is used.
In Charts A and B, T, s, g, ˜, R 4 , and R 5 have the same meanings as defined above; ##STR17## wherein R 10 is a blocking group, which is defined as any group which replaces hydrogen of the hydroxy groups, which is not attacked by nor is reactive to the reagents used in the respective transformation to the extent that the hydroxy group is, and which is subsequently replaceable by hydrogen at a later stage in the preparation of the prostaglandin-type products. Several blocking groups are known in the art, e.g. tetrahydropyranyl and substituted tetrahydropyranyl (see Corey, Proceedings of the Robert A. Welch Foundation Conferences on Chemical Research, XII, Organic Synthesis, pp. 51-79 (1969)). Those blocking groups which have been found useful include:
(1) tetrahydropyranyl;
(2) tetrahydrofuranyl; or
(3) a group of the formula ##STR18## wherein R 11 is alkyl of one to 18 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl substituted with one, 2, or 3 alkyl of one to 4 carbon atoms, inclusive, wherein R 12 and R 13 are the same or different, being hydrogen, alkyl of one to 4 carbon atoms, inclusive, phenyl or phenyl substituted with one, 2, or 3 alkyl of one to 4 carbon atoms, inclusive, or, when R 12 and R 13 are taken together, --(CH 2 ) a -- or --(CH 2 ) b --O--(CH 2 ) c -- wherein a is 3, 4, or 5, b is one, 2, or 3, and c is one, 2, or 3 with the proviso that b plus c is 2, 3, or 4, and wherein R 14 is hydrogen or phenyl.
Further, in Chart B, Q is ##STR19## In Charts A and B, R 9 is an acyl protecting group. Those acyl protecting groups which have been found useful include: ##STR20## wherein R 15 is alkyl of one to 4 carbon atoms, inclusive, phenylalkyl of 7 to 10 carbon atoms, inclusive, or nitro, and k is zero to 5, inclusive, provided that not more than two R 15 are other than alkyl, and that the total number of carbon atoms in the R 15 does not exceed 10 carbon atoms; ##STR21## wherein R 15 is as defined above, inclusive: ##STR22## wherein R 15 and k are as defined above, being the same or different for each ring; or
(4) acetyl.
In preparing the formula XIV compound by replacing the hydrogen of the hydroxyl group in the 3-position with the acyl group R 9 , methods known in the art are used. Thus, an aromatic acid of the formula R 9 OH, wherein R 9 is as defined above, for example benzoic acid, is reacted with the 3α-hydroxy compound in the presence of a dehydrating agent, e.g., carbonyl-bis(imidazole), carbodiimides; or an anhydride of the aromatic acid of the formula (R 9 ) 2 O, for example benzoic anhydride, is used.
Preferably, however, an acyl halide, e.g. R 9 Cl, for example benzoyl chloride, is reacted with the formula XIII compound in the presence of a hydrogen chloride-scavenger, e.g. a tertiary amine such as pyridine, triethylamine, and the like. The reaction is carried out under a variety of conditions using procedures generally known in the art. Generally, mild conditions are employed, e.g. 20°-60° C., contacting the reactions in a liquid medium, e.g. excess pyridine or an inert solvent such as benzene, toluene or chloroform. The acylating agent is used either in stoichiometric amount or in excess.
As examples of R 9 , the following are available as acids (R 9 OH), anhydrides ((R 9 ) 2 O), or acyl chlorides (R 9 Cl): benzoyl; substituted benzoyl, e.g. (2-, 3- or 4-)methylbenzoyl, (2-, 3-, or 4-)ethylbenzoyl, (2-, 3-, or 4-)isopropylbenzoyl, (2-, 3-, or 4-)tert-butylbenzoyl, 2,4-dimethylbenzoyl, 3,5-dimethylbenzoyl, 2-isopropyltoluyl, 2,4,6-trimethylbenzoyl, pentamethylbenzoyl, α-phenyl-(2-, 3-, or 4-)tolyl, (2-, 3-, or 4-)phenethylbenzoyl, 2-, 3-, or 4-nitrobenzoyl, (2,4- 2,5- or 3,5-)dinitrobenzoyl, 3,4-dimethyl-2-nitrobenzoyl, 4,5-dimethyl-2-nitrobenzoyl, 2-nitro-6-phenethylbenzoyl, 3-nitro-2-phenethylbenzoyl; mono-esterified phthaloyl, isophthaloyl, or terephthaloyl, (1- or 2-)naphthoyl; substituted naphthoyl, e.g. (2-, 3-, 4-, 5-, 6-, or 7-)methyl-1-naphthoyl, (2- or 4-)ethyl-1-naphthoyl, 2-isopropyl-1-naphthoyl, 4,5-dimethyl-1-naphthoyl, 6-isopropyl-4-methyl-1-naphthoyl, 8-benzyl-1-naphthoyl, (3-, 4-, 5-, or 8-)nitro-1-naphthoyl, 4,5-dinitro-1-naphthoyl, (3-, 4-, 6-, 7-, or 8-)methyl-1-naphthoyl, 4-ethyl-2-naphthoyl, and (5- or 8-)nitro-2-naphthoyl; and acetyl. There may be employed, therefore, benzoyl chloride, 4-nitrobenzoyl chloride, 3,5-dinitrobenzoyl chloride, and the like, i.e. R 9 Cl compounds corresponding to the above R 9 groups. If the acyl chloride is not available, it is made from the corresponding acid and thionyl chloride as is known in the art. It is preferred that the R 9 OH, (R 9 ) 2 O, or R 9 Cl reactant does not have bulky, hindering substituents, e.g. tert-butyl, on both of the ring carbon atoms adjacent to the carbonyl attaching-site.
The formula-XV compound is next obtained by deiodination of XIV using a reagent which does not react with the lactone ring or the OR 9 moiety, e.g. zinc dust, sodium hydride, hydrazine-palladium, hydrogen and Raney nickel or platinum, and the like. Especially preferred is tributyltin hydride in benzene at about 25° C. with 2,2'-azobis(2-methylpropionitrile) as initiator.
The formula-XVI compound is obtained by demethylation of XV with a reagent that does not attack the OR 9 moiety, for example boron tribromide or trichloride. The reaction is carried out preferably in an inert solvent at about 0°-5° C.
The formula-XVII compound is obtained by oxidation of the --CH 2 OH of XVI to --CHO, avoiding decomposition of the lactone ring. Useful for this purpose are dichromate-sulfuric acid, Jones reagent, lead tetraacetate, and the like. Especially preferred is Collins' reagent (pyridine-CrO 3 ) at about 0°-10° C.
The formula-XVIII compound is obtained by Wittig alkylation of XVII, using the sodio derivative of the appropriate 2-oxo-3-phenoxy (or 3-substituted phenoxy)-alkylphosphonate. The trans enone lactone is obtained stereospecifically (see D. H. Wadsworth et al., J. Org. Chem. Vol. 30, p. 680 (1965)).
In preparing the formula-XVIII compounds of Chart B, certain phosphonates are employed in the Wittig reaction. These are of the general formula ##STR23## wherein R 4 and R 5 are hydrogen, methyl, or ethyl, being the same or different; R 17 is alkyl of one to 8 carbon atoms, inclusive; T is alkyl of one to 3 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or --OR 8 , wherein R 8 is alkyl of one to 3 carbon atoms, inclusive, and s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl, the T's being the same or different.
As examples of phosphonates useful for this purpose there are: ##STR24##
The phosphonates are prepared and used by methods known in the art. See Wadsworth et al., reference cited above. Conveniently, the appropriate aliphatic acid ester is condensed with the anion of dimethyl methylphosphonate produced by n-butyllithium. For this purpose, acids of the general formula ##STR25## are used in the form of their lower alkyl esters, preferably methyl or ethyl. The methyl esters, for example, are readily formed from the acids by reaction with diazomethane. These aliphatic acids of various chain length, with phenoxy or substituted-phenoxy substitution within the scope of ##STR26## as defined above are known in the art or can be prepared by methods known in the art.
Many phenoxy-substituted acids are readily available, e.g. where R 4 and R 5 are both hydrogen: phenoxy-, (o-, m-, or p-)tolyloxy-, (o-, m-, or p-)ethylphenoxy-, 4-ethyl-o-tolyloxy-, (o-, m-, or p-)propylphenoxy-, (o-, m-, or p-)-t-butylphenoxy-, (o-, m-, or p-)fluorophenoxy-, 4-fluoro-2,5-xylyloxy-, (o-, m-, or p-)chlorophenoxy-, (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy-, α,α,α-trifluoro-(o-, m-, or p-)tolyloxy-, or (o-, m-, or p-)methoxyphenoxyacetic acid; where R 4 is methyl and R 5 is hydrogen: 2-phenoxy-, 2-(o-, m-, or p-)tolyloxy-, 2-(3,5-xylyloxy)-, 2-(p-fluorophenoxy)-, 2-[(o-, m-, or p-)chlorophenoxy]-, 2-[(2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy]-, 2-[(4- or 6-)chloro-o-tolyloxy], or 2-(α,α,α-trifluoro-m-tolyloxy)-propionic acid; wherein R 4 and R 5 are both methyl: 2-methyl-2-phenoxy-, 2-[(o-, m-, or p-)chlorophenoxy]-2-methyl-, or 2-[(2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy]-2-methylpropionic acid; where R 4 is ethyl and R 5 is hydrogen: 2 -phenoxy-, 2-[(o-, m-, or p-)fluorophenoxy]-, 2-[(o-, m-, or p-)chlorophenoxy]-, 2-[(2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy]-, or 2-(2-chloro-4-fluorophenoxy)butyric acid; wherein R 4 is ethyl and R 5 is methyl: 2-methyl-2-phenoxy- or 2-[(o-, m-, or p-)chlorophenoxy]-2-methylbutyric acid.
Other phenoxy substituted acids are available by methods known in the art, for example, by the Williamson synthesis of ethers using an alpha-halo aliphatic acid or ester with sodium phenoxide or a substituted sodium phenoxide. Thus, for example, the methyl ester of 2-)o-methoxyphenoxy)-2-methylbutyric acid is obtained by the following reaction: ##STR27## The reaction proceeds smoothly with heating and the product is recovered in the conventional way. The methyl ester is used for preparing the corresponding phosphonate as discussed above.
Alternatively, the phosphonate is prepared from an aliphatic acyl halide and the anion of a dialkyl methylphosphonate. Thus, 2-methyl-2-phenoxypropionyl chloride and dimethyl methylphosphonate yield dimethyl 2-oxo-3-methyl-3-phenoxybutylphosphonate. The acyl halides are readily available from the aliphatic acids by methods known in the art, e.g. chlorides are conveniently prepared using thionyl chloride.
Continuing with Chart B, the formula-XIX compound is obtained as a mixture of alpha and beta isomers by reduction of XVIII. For this reduction, use is made of any of the known ketonic carbonyl reducing agents which do not reduce ester or acid groups or carbon-carbon double bonds when the latter is undesirable. Examples of those are the metal borohydrides, especially sodium, potassium, and zinc borohydrides, lithium (tri-tert-butoxy)aluminum hydride, metal trialkoxy borohydrides, e.g., sodium trimethoxyborohydride, lithium borohydride, diisobutyl aluminum hydride, and when carbon-carbon double bond reduction is not a problem, the boranes, e.g., disiamylborane (bis-3-methyl-2-butylborane).
For production of natural-configuration PG-type compounds, the desired 15-alpha form of the formula-XIX compound is separated from the 15-beta isomer by silica gel chromatography.
The formula-XX compound is then obtained by deacylation of XIX with an alkali metal carbonate, for example, potassium carbonate in methanol at about 25° C.
When the blocking group R 10 is tetrahydropyranyl, the bis(tetrahydropyranyl ether) XXI is obtained by reaction of the formula-XX diol with 2,3-dihydropyran in an inert solvent, e.g., dichloromethane, in the presence of an acid condensing agent such as p-toluenesulfonic acid or pyridine hydrochloride. The dihydropyran is used in excess, preferably 4 to 10 times the stoichiometric amount. The reaction is normally complete in 1-10 hr. at 20°-50° C. When the blocking group is tetrahydrofuranyl, 2,3-dihydrofuran is used instead. When the blocking group is of the formula ##STR28## as defined above, the appropriate reagent is a vinyl ether, e.g. isobutyl vinyl ether or any vinyl ether of the formula
R.sub.11 --O--C(R.sub.12)═CR.sub.13 R.sub.14
wherein R 11 , R 12 , R 13 , and R 14 are as defined above; or an unsaturated cyclic or heterocyclic compound, e.g. 1-cyclohexen-1-yl methyl ether or 5,6-dihydro-4-methoxy-2H-pyran. See C. B. Reese et al., J. Am. Chem. Soc. 89, 3366 (1967). The reaction conditions for such vinyl ethers and unsaturated compounds are similar to those for dihydropyran above.
The lactol XXII is obtained on reduction of the formula-XXI lactone without reducing the 13,14-ethylenic group. For this purpose, diisobutylaluminum hydride is used. The reduction is preferably done at -60° to -70° C. The 15β-epimer of the formula-XXI lactone is readily obtained by the steps of Chart B, using the 15β isomer of formula XIX.
The formula-XXIII compound is obtained from the formula-XXII lactol by the Wittig reaction, using a Wittig reagent derived from the appropriate ω-carboxyalkyltriphenylphosphonium bromide, HOOC--CH 2 --(CH 2 ) g --P(C 6 H 5 ) 3 Br, and sodio dimethylsulfinylcarbanide. The reaction is conveniently carried out at about 25° C. This formula-XXIII compound serves as an intermediate for preparing either certain PGF 2 α -type or PGE 2 -type intermediates (Chart C). The phosphonium compounds are known in the art or are readily available, e.g. by reaction of an ω-bromoaliphatic acid with triphenylphosphine.
The formula-XXIV PGF 2 α -type intermediate is obtained on hydrolysis of the blocking groups from the formula-XXIII compound, e.g. with methanol-HCl, acetic acid/water/tetrahydrofuran, aqueous citric acid, or aqueous phosphoric acidtetrahydrofuran, preferably at temperatures below 55° C., thereby avoiding formation of PGA 2 -type compounds as by-products. Reference to Chart C will make clear the preparation of certain PGE 2 -type intermediates. The 11,15-diether of the PGF 2 α -type products represented by formula XXIII oxidized at the 9-hydroxy position, preferably with Jones reagent. Finally the blocking groups are replaced with hydrogen, by hydrolysis as in preparing the PGF 2 α -type intermediate of Chart B. In Chart C, the symbols g, M 2 , Q, and R 10 have the same meanings as in Charts A and B. ##STR29##
Referring to Chart D, there is shown the transformation of lactone XIX to 15-alkyl ether PGF-type products of formula-XXX. In Chart D, g, M 2 , Q, R 1 , R 9 , R 10 , and ˜ have the same meanings as above. M 6 is either ##STR30## wherein R 18 is alkyl of one to 2 carbon atoms, inclusive. The starting materials are available from the steps of Chart B above or are readily available by methods known in the art.
The formula-XXVIII compound is prepared by alkylation of the side-chain hydroxy of the formula-XIX compound thereby replacing hydroxy with the --OR 18 moiety. For this purpose, diazoalkanes may be employed, preferably in the presence of a Lewis acid, e.g. boron trifluoride etherate, aluminum chloride, or fluoboric acid. When R 18 is methyl, diazomethane is used. See Fieser et al., "Reagents for Organic Synthesis", John Wiley and Sons, Inc., N.Y. (1967), p. 191. Other --OR 18 groups are formed by using the corresponding diazoalkane. For example diazoethane and diazomethane yield --OC 2 H 5 and --OCH 3 respectively. The reaction is carried out by mixing a solution of the diazoalkane in a suitable inert solvent, preferably ethyl ether, with the formula-XIX compound. Generally the reaction proceeds at about 25° C. Diazoalkanes are known in the art or can be prepared by methods known in the art. See, for example, Organic Reactions, John Wiley and Sons, Inc., N.Y. Vol. 8. pp. 389-394 (1954).
Another method for the alkylation of the side chain hydroxy is by reaction with an alcohol in the presence of boron trifluoride etherate. Thus, methanol and boron trifluoride etherate yield the methyl ether wherein R 18 is methyl. The reaction is done at about 25° C. and is conveniently followed with thin layer chromatography (TLC).
Another method for the alkylation of the side-chain hydroxy is by the reaction of an alkyl halide, e.g. methyl iodide, in the presence of a metal oxide or hydroxide, e.g. barium oxide, silver oxide, or barium hydroxide. An inert solvent may be beneficial, for example benzene or dimethylformamide. The reactants are preferably stirred together and maintained at temperatures of 25°-75° C.
The formula-XXIX compound is then obtained in the conventional manner, for example by low temperature reduction with diisobutylaluminum hydride as discussed above for Chart B. The final 15-alkyl ether PGF.sub.α product XXX is obtained from either XXVIII or XXIX by the same reactions and conditions discussed above for the steps of Chart B.
Further, by the method of Chart C the formula XXIX compound is transformed to the corresponding PGE-type compound of this invention.
Referring to Chart E, there is shown the transformation of lactone XVIII to lactol XXXIV useful for preparing 15-alkyl-PG-type products. In Chart E, Q, R 4 , R 5 , R 10 , and ˜ are as defined above for Chart B, M 8 is a mixture of ##STR31## wherein R 19 is alkyl of one to 2 carbon atoms, inclusive, M 7 is a mixture of ##STR32## wherein R 19 and R 10 are as defined above.
For the starting material XVIII refer to Chart B and the discussion pertaining thereto. Intermediate XXXI is obtained by replacing the side-chain oxo with M 6 by a conventional Grignard reaction, employing R 19 MgHal. Next, the acyl group R 9 is removed by hydrolysis and the hydrogen atoms of the hydroxyl groups are replaced with blocking groups R 10 following the procedures of Chart B. Finally lactol XXXIV is obtained by reduction of lactone XXXIII in the same manner discussed above for Charts B and D. ##STR33##
The 15-alkyl products of this invention are obtained from the formula-XXXIV lactol, following the procedures discussed above for Chart B. The 15-R and 15-S isomers are separated by conventional means, for example silica gel chromatography at either the lactone, lactol, or the final product stages.
Advantageously, separation techniques, such as high pressure liquid chromatography, are employed on PG-type, methyl ester products. In a similar fashion the corresponding PGE-type compounds are prepared from the formula-XXXIV compound using the procedures of Charts B and C.
Referring to Chart F, there is shown a convenient method for obtaining the 15-alkyl products from corresponding PGF-type intermediates shown broadly by formula XXXV. In Chart F, g, M 1 , Q, R 1 , R 19 , Y, and ˜ are as defined above. G is alkyl of one to 4 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl substituted with one or 2 fluoro, chloro, or alkyl of one to 4 carbon atoms, inclusive, and R 20 is R 1 as defined above or silyl of the formula-Si-(G) 3 wherein G is as defined above. The various G's of a --Si(G) 3 moiety are alike or different. For example, a --Si(G) 3 can be trimethylsilyl, dimethyl(t-butyl)silyl, dimethylphenylsilyl, or methylphenylbenzylsilyl. Examples of alkyl of one to 4 carbon atoms, inclusive, are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and tert-butyl. Examples of aralkyl of 7 to 12 carbon atoms, inclusive, are benzyl, phenethyl, α-phenylethyl, 3-phenylpropyl, α-naphthylmethyl, and 2-(β-naphthyl)ethyl. Examples of phenyl substituted with one or 2 fluoro, chloro, or alkyl of one to 4 carbon atoms, inclusive, are p-chlorophenyl, m-fluorophenyl, o-tolyl, 2,4-dichlorophenyl, p-tert-butylphenyl, 4-chloro-2-methylphenyl, and 2,4-dichloro-3-methylphenyl. ##STR34##
This method is well-known for preparing 15-alkyl prostaglandins. See South African Pat. No. 2482, May 3, 1972, or Belgian Pat. No. 766,682, Derwent No. 72109S.
The acids and esters of formula XXXV, available herein by the processes of the preceding charts, are transformed to the corresponding intermediate 15-oxo acids and esters of formula XXXVI, respectively, by oxidation with reagents such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, activated manganese dioxide, or nickel peroxide (see Fieser et al., "Reagents for Organic Synthesis," John Wiley and Sons, Inc., New York, N.Y., pp. 215, 637 and 731).
Continuing with Chart F, intermediate XXXVI is transformed to a silyl derivative of formula XXXVII by procedures known in the art. See, for example, Pierce, "Silylation of Organic Compounds," Pierce Chemical Co., Rockford, Ill. (1968). Both hydroxy groups of the formula-XXVI reactant are thereby transformed to --O--Si--(G) 3 moieties wherein G is as defined above, and sufficient of the silylating agent is used for that purpose according to known procedures. When R 1 in the formula-XXXVI intermediate is hydrogen, the --COOH moiety thereby defined is usually transformed to --COO--Si--(G) 3 , additional silylating agent being used for this purpose. This latter transformation is aided by excess silylating agent and prolonged treatment. When R 1 in formula XXXVI is alkyl, then R 20 in formula XXXVII will also be alkyl. The necessary silylating agents for these transformations are known in the art or are prepared by methods known in the art. See, for example, Post, "Silicones and Other Silicon Compounds," Reinhold Publishing Corp., New York, N.Y. (1949).
The intermediate silyl compound of formula XXXVII is transformed to the final compounds of formula XXXVIII-XXXIX by first reacting the silyl compound with a Grignard reagent of the formula R 19 MgHal wherein R 19 is defined as in Chart F, and Hal is chloro, bromo, or iodo. For this purpose, it is preferred that Hal be bromo. This reaction is carried out by the usual procedure for Grignard reactions, using diethyl ether as a reaction solvent and saturated aqueous ammonium chloride solution to hydrolyze the Grignard complex. The resulting disilyl or trisilyl tertiary alcohol is then hydrolyzed with dilute aqueous acetic acid. For this purpose, it is advantageous to use a diluent of water and sufficient of a water-miscible solvent, e.g., ethanol to give a homogenous reaction mixture. The hydrolysis is usually complete in 2 to 6 hours at 25° C., and is preferably carried out in an atmosphere of an inert gas, e.g., nitrogen or argon.
The mixture of 15-(S) and 15-(R) isomers obtained by this Grignard reaction and hydrolysis is separated by procedures known in the art for separating mixtures of prostanoic acid derivatives, for example, by high pressure liquid chromatography. In this instance, the lower alkyl esters, especially the methyl esters of a pair of 15(R) and 15(S) isomers are more readily separated by high pressure chromatography than are the corresponding acids. In this case, it is advantageous to esterify the mixture of acids as described below, separate the two esters, and then, if desired, saponify the esters by procedures known in the art for saponification of prostaglandins F.
Referring to Chart G, there is shown a preferred method of obtaining the 15-alkyl-PGF-type compounds as 15-alkyl ethers. In Chart G, g, M 2 , M 3 , M 6 , Q, R 1 , R 10 , Y and ˜ are as defined above. M 8 is either ##STR35## wherein R 18 and R 19 are as defined above, i.e. alkyl of one to 2 carbon atoms, inclusive, being the same or different. Starting material XXXV and intermediate XXXVI are identical with those of Chart F. Compound XL is obtained by replacing the hydrogen atoms of the C-9 and C-11 hydroxys with blocking groups R 10 by the methods discussed above for Chart B. Compound XLI is then obtained by replacing the C-15 oxo with M 6 by a Grignard reaction, employing R 19 MgHal. Thereafter, a compound XLII is obtained by alkylation of the C-15 hydroxy using the methods and reagents discussed above for Chart D, for example diazoalkanes. Finally, the formula-XLII compound is readily transformed to the PGF-type products by hydrolysis of the R 10 blocking groups. The 15α and 15β isomers are separated by conventional means, for example high pressure liquid chromatography, as above.
Chart H shows a method whereby the novel PGF 2 α -type compounds of this invention are transformed into the corresponding novel PGE 2 -type compounds of this invention. ##STR36## With reference to Chart H, M 3 , Q, and g are as defined hereinabove. R 3 is hydrogen, alkyl of 1 to 12 carbon atoms inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl or phenyl substituted with 1, 2, or 3 chloro or alkyl of 1 to 4 carbon atoms, inclusive, and G is alkyl of 1 to 4 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl substituted with 1 to 2 fluoro or chloro, or alkyl of 1 to 4 carbon atoms, inclusive, the various G's being the same or different.
The formula-LXXIII PGF 2 α -type compound is transformed by selective silylation into the formula-LXXIV 11-silyl derivative, by procedures known in the art. For a list of suitable silylation agents, see for reference Post, Silicones and Other Organic Compounds, Reinhold Publishing Company, New York, New York (1949). Procedures for this selective monosilylation are known in the art. See for reference U.S. Pat. No. 3,822,303.
The formula-LXXIV compound is then oxidized to form the formula-LXXV PGE 2 -type compound by methods known in the art. By a preferred route the Collins' reagent is used to effect this oxidation by methods known in the art. See for reference J. C. Collins, et al., Tetrahedron Letters 3363 (1968).
The formula-LXXVI PGE 2 -type compound is then produced by hydrolysis. This hydrolysis is effectively carried out under acidic conditions as is known in the art. For example, a diluent of water and a water miscible alcohol such as ethanol, is used to provide a homogeneous reaction mixture. The reaction proceeds to completion at 25° C. under a nitrogen or argon atmosphere in 2 to 6 hours.
By an optional route the PGF 2 α-type compounds of this invention are prepared from the corresponding lactone starting material using the procedure of the above charts, except that the use of blocking groups is omitted. Thus, by this optional route the lactol intermediates above are transformed to the free acid prostaglandin-type compounds of this invention by Wittig alkylation, without subsequent hydrolysis of any blocking groups.
The PGE 1 - and 13,14-dihydro-PGE 2 -type products of this invention are prepared by ethylenic reduction of the corresponding PGE 2 -type compounds. Reducing agents useful for this transformation are known in the art. Thus, hydrogen is used at atmospheric pressure or low pressure with catalysts such as palladium on charcoal or rhodium on aluminum. See, for example, E. J. Corey et al., J. Am. Chem. Soc. 91, 5677 (1969) and B. Samuelsson, J. Biol. Chem. 239, 4091 (1964). For the PGE 1 type compounds, the reduction is terminated when one equivalent of hydrogen is absorbed; for the 13,14-dihydro-PGE 1 type compounds, when two equivalents are absorbed. For the PGE 1 -type compounds it is preferred that a catalyst be used which selectively effects reduction of the cis-5,6-carbon-carbon double bond in the presence of the trans-13,14 unsaturation. Mixtures of the products are conveniently separated by silica gel chromatography.
Alternatively, the 11-mono- or 11,15-bis-silyl ethers of the PGE 2 -type compounds (formula LXXV of Chart H) are reduced and subsequently hydrolyzed to remove the silyl groups. ##STR37##
Chart I shows transformations from the novel PGE-type compounds to the corresponding PGF-, PGA-, and PGB-type compounds. In figures LXXVII, LXXVIII, LXXIX, and LX of Chart I, g, Q, and ˜ have the same meanings as in Chart B; R 1 has the same meaning as in Chart D; M is ##STR38## wherein R 7 and R 8 are hydrogen or alkyl of one to 2 carbon atoms, inclusive, being the same or different, with the proviso that at least one of R 7 or R 8 is alkyl of one to 2 carbon atoms, inclusive; and (a) X is trans-CH═CH-- or --CH 2 CH 2 --, and Y is --CH 2 CH 2 --, or (b) X is trans-CH═CH-- and Y is cis-CH═CH--. When X is trans-CH═CH-- and Y is --CH 2 CH 2 --, formula LXXVII represents PGE 1 type compounds; when X is --CH 2 CH 2 -- and Y is --CH 2 CH 2 --, formula LXXVII represents 13,14-dihydro-PGE 1 type compounds; and when X is trans-CH═CH-- and Y is cis-CH═CH--, formula LXXVII represents PGE 2 type compounds. Thus, formulas LXXVII, LXXVIII, LXXIX, and LX embrace all of the novel compounds of this invention.
Thus, the various PGF.sub.β -type compounds encompassed by formulas I, II, and III are prepared by carbonyl reduction of the corresponding PGE-type compounds, e.g. formulas IV, V, and VI.
These ring carbonyl reductions are carried out by methods known in the art for ring carbonyl reductions of known prostanoic acid derivatives. See, for example, Bergstrom et al., Arkiv Kemi 19, 563 (1963), Acta. Chem. Scand. 16, 969 (1962), and British Specification No. 1,097,533. Any reducing agent is used which does not react with carbon-carbon double bonds or ester groups. Preferred reagents are lithium(tri-tert-butoxy)aluminum hydride, the metal borohydrides, especially sodium, potassium and zinc borohydrides, the metal trialkoxy borohydrides, e.g., sodium trimethoxyborohydride. The mixtures of alpha and beta hydroxy reduction products are separated into the individual alpha and beta isomers by methods known in the art for the separation of analogous pairs of known isomeric prostanoic acid derivatives. See, for example, Bergstrom et al., cited above, Granstrom et al., J. Biol. Chem. 240, 457 (1965), and Greene et al., J. Lipid Research 5, 117 (1964). Alternatively useful as separation methods are partition chromatographic procedures, both normal and reversed phase, preparative thin layer chromatography, and countercurrent distribution procedures.
The various PGA-type compounds encompassed by formulas X, XI, and XII are prepared by acidic dehydration of the corresponding PGE-type compounds, e.g. formulas IV, V, and VI.
These acidic dehydrations are carried out by methods known in the art for acidic dehydrations of known prostanoic acid derivatives. See, for example, Pike et al., Proc. Nobel Symposium II, Stockholm (1966), Interscience Publishers, New York, pp. 162-163 (1967); and British Specification No. 1,097,533. Alkanoic acids of 2 to 6 carbon atoms, inclusive, especially acetic acid, are preferred acids for this acidic dehydration. Dilute aqueous solutions of mineral acids, e.g., hydrochloric acid, especially in the presence of a solubilizing diluent, e.g., tetrahydrofuran, are also useful as reagents for this acidic dehydration, although these reagents may cause partial hydrolysis of an ester reactant.
The various PGB-type compounds encompassed by formulas VII, VIII, and IX are prepared by basic dehydration of the corresponding PGE-type compounds encompassed by formulas IV, V, and VI or by contacting the corresponding PGA-type compounds encompassed by formulas X, XI, and XII with base.
These dehydrations and double bond migrations are carried out by methods known in the art for similar reactions of known prostanoic acid derivatives. See, for example, Bergstrom et al., J. Biol. Chem. 238, 3555 (1963). The base is any whose aqueous solution has pH greater than 10. Preferred bases are the alkali metal hydroxides. A mixture of water and sufficient of a water-miscible alkanol to give a homogeneous reaction mixture is suitable as a reaction medium. The PGE-type or PGA-type compound is maintained in such a reaction medium until no further PGB-type compound is formed, as shown by the characteristic ultraviolet light absorption near 278 μ for the PGB-type compound.
Optically active compounds are obtained from optically active intermediates according to the process steps of Charts A, B, D, and E. Likewise, optically active products are obtained by the transformations of optically active compounds following the processes of Charts C, F, G, and H. When racemic compounds are used in reactions corresponding to the processes of Charts A-H, inclusive, and racemic products are obtained, these racemic products may be used in their racemic form or, if preferred, they may be resolved as optically active isomers by procedures known in the art.
For example, when final compound I to XII is a free acid, the dl form thereof is resolved into the d and l forms by reacting said free acid by known general procedures with an optically active base, e.g., brucine or strychnine, to give a mixture of two diastereoisomers which are separated by known general procedures, e.g., fractional crystallization, to give the separate diastereoisomeric salts. The optically active acid of formula I to XII is then obtained by treatment of the salt with an acid by known general procedures.
As discussed above, the stereochemistry at C-15 is not altered by the transformations of Charts A and B; the 15β epimeric products of formula XXIV are obtained from 15β formula-XIX reactants. Another method of preparing the 15β products is by isomerization of the PGF 1 - or PGE 1 -type compounds having 15α configuration, by methods known in the art. See, for example, Pike et al., J. Org. Chem. 34, 3552 (1969).
As discussed above, the processes herein described inclusive, lead variously to acids (R 1 is hydrogen) or to esters.
When the alkyl ester has been obtained and an acid is desired, saponification procedures, as known in the art for F-type prostaglandins may be used.
For alkyl esters of E-type prostaglandins enzymatic processes for transformation of esters to their acid forms may be used by methods known in the art. See for reference E. G. Daniels, Process for Producing An Esterase, U.S. Pat. No. 3,761,356.
When an acid has been prepared and an alkyl, cycloalkyl or aralkyl ester is desired, esterification is advantageously accomplished by interaction of the acid with the appropriate diazohydrocarbon. For example, when diazomethane is used, the methyl esters are produced. Similar use of diazoethane, diazobutane, and 1-diazo-2-ethylhexane, and diazodecane, for example, gives the ethyl, butyl, and 2-ethylhexyl and decyl esters, respectively.
Similarly, diazocyclohexane and phenyldiazomethane yield cyclohexyl and benzyl esters respectively.
Esterification with diazohydrocarbons is carried out by mixing a solution of the diazohydrocarbon in a suitable inert solvent, preferably diethyl ether, with the acid reactant, advantageously in the same or a different inert diluent. After the esterification reaction is complete, the solvent is removed by evaporation, and the ester purified if desired by conventional methods, preferably by chromatography. It is preferred that contact of the acid reactants with the diazohydrocarbon be no longer than necessary to effect the desired esterification, preferably about one to about ten minutes, to avoid undesired molecular changes. Diazohydrocarbons are known in the art or can be prepared by methods known in the art. See, for example, Organic Reactions, John Wiley and Sons, Inc., New York, N.Y., Vol. 8, pp. 389-394 (1954).
The phenyl and substituted phenyl esters of this invention are prepared by methods known in the art. For example, the prostaglandin-type free acid may be silylated by methods known in the art, thereby protecting the free hydroxy groups. Since the silylation often transforms the carboxy acid moiety, --COOH, into a silyl ester derivative, a brief treatment of the silylated compound with water may be necessary to transform the silylated compound into free acid form. This free acid may then be reacted with oxalyl chloride to provide an acid chloride. The acid chloride may be esterified by reacting it with phenol or the appropriate substituted phenol to give a silylated phenyl or substituted phenyl ester. Finally, the silyl groups are replaced by free hydroxy moieties by hydrolysis under acidic conditions. For this purpose dilute acetic acid may be advantageously used.
An alternative method for alkyl, cycloalkyl or aralkyl esterification of the carboxyl moiety of the acid compounds comprises transformation of the free acid to the corresponding silver salt, followed by interaction of that salt with an alkyl iodide. Examples of suitable iodides are methyl iodide, ethyl iodide, butyl iodide, isobutyl iodide, tert-butyl iodide, cyclopropyl iodide, cyclopentyl iodide, benzyl iodide, phenethyl iodide, and the like. The silver salts are prepared by conventional methods, for example, by dissolving the acid in cold dilute aqueous ammonia, evaporating the excess ammonia at reduced pressure, and then adding the stoichiometric amount of silver nitrate.
Various methods are available for preparing phenyl esters, substituted phenyl esters and particularly the following esters of this invention: ##STR39## from corresponding phenols or naphthol and the free acid of a prostaglandin-type compound differing as to yield and purity of product.
Thus by one method, the PG compound is converted to a tertiary amine salt, reacted with pivaloyl halide to give the mixed acid anhydride and then reacted with the phenol. Alternatively, instead of pivaloyl halide, an alkyl or phenylsulfonyl halide is used, such as p-toluenesulfonyl chloride. See for example Belgiam Pat. Nos. 775,106 and 776,294, Derwent Farmdoc Nos. 33705T and 39011T.
Still another method is by the use of the coupling reagent, dicyclohexylcarbodiimide. See Fieser et al., "Reagents for Organic Synthesis", pp. 231-236, John Wiley and Sons, Inc., New York (1967). The PG compound is contacted with one to ten molar equivalents of the phenol in the presence of 2-10 molar equivalents of dicyclohexylcarbodiimide in pyridine as a solvent.
The preferred novel process for the preparation of these esters, however, comprises the steps (1) forming a mixed anhydride with the prostaglandin-type compound and isobutylchloroformate in the presence of a tertiary amine and (2) reacting the anhydride with an appropriate phenol or naphthol.
The mixed anhydride is represented by the formula: ##STR40## for the optically active PG compounds, D, R 4 , R 5 , M, T, s, X and Y, all having the same definition as hereinabove.
The anhydride is formed readily at temperatures in the range -40° to +60° C., preferably at -10° to +10° C. so that the rate is reasonably fast and yet side reactions are minimized. The isobutylchloroformate reagent is preferably used in excess, for example 1.2 molar equivalents up to 4.0 per mole of prostaglandin-type compound. The reaction is preferably done in a solvent and for this purpose acetone is preferred, although other relatively non-polar solvents are used such as acetonitrile, dichloromethane, and chloroform. The reaction is run in the presence of a tertiary amine, for example triethylamine, and the co-formed amine hydrochloride usually crystallizes out, but need not be removed for the next step.
The phenol is preferably used in equivalent amounts or in excess to insure that all of the mixed anhydride is converted to ester. Excess phenol is separated from the product by methods described herein or known in the art, for example by crystallization. The tertiary amine is not only a basic catalyst for the esterification but also a convenient solvent. Other examples of tertiary amines useful for this purpose include N-methylmorpholine, triethylamine, diisopropylethylamine, and dimethylaniline. Although they may be used, 2-methylpyridine and quinoline result in a slow reaction. A highly hindered amine such as 2,6-dimethyllutidine is not useful because of the slowness of the reaction.
The reaction with the anhydride proceeds smoothly at room temperature (about 20° to 30° C.) and can be followed in the conventional manner with thin layer chromatography.
The reaction mixture is worked up to yield the ester following methods known in the art, and the product is purified, for examply by silica gel chromatography.
Solid esters are converted to a free-flowing crystalline form on crystallization from a variety of solvents, including ethyl acetate, tetrahydrofuran, methanol, and acetone, by cooling or evaporating a saturated solution of the ester in the solvent or by adding a miscible nonsolvent such as diethyl ether, hexane, or water. The crystals are then collected by conventional techniques, e.g. filtration or centrifugation, washed with a small amount of solvent, and dried under reduced pressure. They may also be dried in a current of warm nitrogen or argon, or by warming to about 75° C. Although the crystals are normally pure enough for many applications, they may be recrystallized by the same general techniques to achieve improved purity after each recrystallization.
The compounds of this invention prepared by the processes of this invention, in free acid form, are transformed to pharmacologically acceptable salts by neutralization with appropriate amounts of the corresponding inorganic or organic base, examples of which correspond to the cations and amines listed hereinabove. These transformations are carried out by a variety of procedures known in the art to be generally useful for the preparation of inorganic, i.e., metal or ammonium salts. The choice of procedure depends in part upon the solubility characteristics of the particular salt to be prepared. In the case of the inorganic salts, it is usually suitable to dissolve an acid of this invention in water containing the stoichiometric amount of a hydroxide, carbonate, or bicarbonate corresponding to the inorganic salt desired. For example, such use of sodium hydroxide, sodium carbonate, or sodium bicarbonate gives a solution of the sodium salt. Evaporation of the water or addition of a water-miscible solvent of moderate polarity, for example, a lower alkanol or a lower alkanone, gives the solid inorganic salt if that form is desired.
To produce an amine salt, an acid of this invention is dissolved in a suitable solvent of either moderate or low polarity. Examples of the former are ethanol, acetone, and ethyl acetate. Examples of the latter are diethyl ether and benzene. At least a stoichiometric amount of the amine corresponding to the desired cation is then added to that solution. If the resulting salt does not precipitate, it is usually obtained in solid form by addition of a miscible diluent of low polarity or by evaporation. If the amine is relatively volatile, any excess can easily be removed by evaporation. It is preferred to use stoichiometric amounts of the less volatile amines.
Salts wherein the cation is quaternary ammonium are produced by mixing an acid of this invention with the stoichiometric amount of the corresponding quaternary ammonium hydroxide in water solution, followed by evaporation of the water.
The acids or esters of this invention prepared by the processes of this invention are transformed to lower alkanoates by interaction of a free hydroxy compound with a carboxyacylating agent, preferably the anhydride of a lower alkanoic acid, i.e., an alkanoic acid of two to 8 carbon atoms, inclusive. For example, use of acetic anhydride gives the corresponding acetate. Similar use of propionic anhydride, isobutyric anhydride, and hexanoic acid anhydride gives the corresponding carboxyacylates.
The carboxyacylation is advantageously carried out by mixing the hydroxy compound and the acid anhydride, preferably in the presence of a tertiary amine such as pyridine or triethylamine. A substantial excess of the anhydride is used, preferably about 10 to about 10,000 moles of anhydride per mole of the hydroxy compound reactant. The excess anhydride serves as a reaction diluent and solvent.
Alternatively an inert organic diluent, for example, dioxane, can also be added. It is preferred to use enough of the tertiary amine to neutralize the carboxylic acid produced by the reaction, as well as any free carboxyl groups present in the hydroxy compound reactant.
The carboxyacylation reaction is preferably carried out in the range about 0° to about 100° C. The necessary reaction time will depend on such factors as the reaction temperature, and the nature of the anhydride and tertiary amine reactants. With acetic anhydride, pyridine, and a 25° C. reaction temperature, a 12 to 24-hour reaction time is used.
The carboxyacylated product is isolated from the reaction mixture by conventional methods. For example, the excess anhydride is decomposed with water, and the resulting mixture acidified and then extracted with a solvent such as diethyl ether. The desired carboxyacylate is recovered from the diethyl ether extract by evaporation. The carboxyacylate is then purified by conventional methods, advantageously by chromatography or crystallization.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention can be more fully understood by the following examples and preparations.
All temperatures are in degrees centigrade.
IR (infrared) absorption spectra are recorded on a Perkin-Elmer Model 421 infrared spectrophotometer. Except when specified otherwise, undiluted (neat) samples are used.
UV (Ultraviolet) spectra are recorded on a Cary Model 15 spectrophotometer.
NMR (Nuclear Magnetic Resonance) spectra are recorded on a Varian A-60, A-60D, or T-60 spectrophotometer on deuterochloroform solutions with tetramethylsilane as an internal standard (downfield).
Mass spectra are recorded on a CEG Model 110B Double Focusing High Resolution Mass Spectrometer or an LKB Model 9000 Gas-Chromatograph-Mass Spectrometer (ionization voltage 70 ev). Trimethylsilyl derivatives are used.
The collection of chromatographic eluate fractions starts when the eluant front reaches the bottom of the column in those cases employing a dry-packed column.
"Brine", herein, refers to an aqueous saturated sodium chloride solution.
The A-IX solvent system used in thin layer chromatography is made up from ethyl acetate-acetic acid-2,2,4-trimethylpentane-water (90:20:50:100) according to M. Hamberg and B. Samuelsson, J. Biol. Chem. 241, 257 (1966). "Skellysolve-B" (SSB) refers to mixed isomeric hexanes.
Silica gel chromatography, as used herein, is understood to include elution, collection of fractions, and combination of those fractions shown by TLC (thin layer chromatography) to contain the desired product free of starting material and impurities.
Melting points (MP) are determined on a Fisher-Johns melting point apparatus.
DDQ refers to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone.
Specific Rotations, [α], are determined for solutions of a compound in the specified solvent at ambient temperature with a Perkin-Elmer Model 141 Automatic Polarimeter.
Preparation 1 3α-Benzoyloxy-2β-carboxaldehyde-5α-hydroxy-1α-cyclopentaneacetic Acid γ-Lactone (Formula XVII: R 9 is benzoyl).
Refer to Chart A.
A. To a mixture of formula-XIII laevorotatory (-) 3α-hydroxy-5α-hydroxy-4-iodo-2β-methoxy-methyl-1α-cyclopentaneacetic acid γ-lactone (E. J. Corey et al., J. Am. Chem. Soc. 92, 297 (1970), 75 g.) ir 135 ml. of dry pyridine under a nitrogen atmosphere is added 30.4 ml. of benzoyl choride with cooling to maintain the temperature at about 20°-40° C. Stirring is continued for an additional 30 min. About 250 ml. of toluene is added and the mixture concentrated under reduced pressure. The residue is dissolved in one liter of ethyl acetate, washed with 10% sulfuric acid, brine, aqueous saturated sodium bicarbonate, and brine. The ethyl acetate solution is dried over sodium sulfate and concentrated under reduced pressure to yield an oil, 95 g. Crystallization of the oil yields the corresponding 3α-benzoyloxy compound, m.p. 84°-86° C.; [α] D +7° (CHCl 3 ); infrared spectral absorptions at 1768, 1722, 1600, 1570, 1490, 1275, 1265, 1180, 1125, 1090, 1060, 1030, and 710 cm -1 ; and NMR (nuclear magnetic resonance) peaks at 2.1-3.45, 3.3, 3.58, 4.38, 5.12, 5.51, 7.18-7.58, and 7.83-8.05 δ.
B. The iodo group is removed as follows. To a solution of the above benzoyloxy compound (60g.) in 240 ml. of dry benzene is added 2,2'-azobis-(2-methylpropionitrile) (approximately 60 mg.). The mixture is cooled to 15° C. and to it is added a solution of 75 g. tributyltin hydride in 600 ml. of ether, with stirring, at such a rate as to maintain continuous reaction at about 25° C. When the reaction is complete as shown by TLC (thin layer chromatography) the mixture is concentrated under reduced pressure to an oil. The oil is mixed with 600 ml. of Skellysolve B (mixed isomeric hexanes) and 600 ml. of water and stirred for 30 min. The water layer, containing the product, is separated, then combined with 450 ml. of ethyl acetate and enough solid sodium chloride to saturate the aqueous phase. The ethyl acetate layer, now containing the product, is separated, dried over magnesium sulfate, and concentrated under reduced pressure to an oil, 39 g. of the iodine-free compound. An analytical sample gives [α] D -99° (CHCl 3 ); infrared spectral absorptions at 1775, 1715, 1600, 1585, 1490, 1315, 1275, 1180, 1110, 1070, 1055, 1025, and 715 cm -1 .; NMR peaks at 2.5-3.0, 3.25, 3.34, 4.84-5.17, 5.17-5.4, 7.1-7.5, and 7.8-8.05 δ; and mass spectral peaks at 290, 168, 105, and 77.
C. The 2β -methoxymethyl compound is changed to a hydroxymethyl compound as follows. To a cold (0.5° C.) solution of the above iodine-free methoxy-methyl lactone (20 g.) in 320 ml. of dichloromethane under nitrogen is added a solution of 24.8 ml. of boron tribromide in 320 ml. of dichloromethane, dropwise with vigorous stirring over a period of 50 min. at 0°-5° C. Stirring and cooling are continued for one hour. When the reaction is complete, as shown by TLC, there is cautiously added a solution of sodium carbonate (78 g.) monohydrate in 200 ml. of water. The mixture is stirred at 0°-5° C. for 10-15 min., saturated with sodium chloride, and the ethyl acetate layer separated. Additional ethyl acetate extractions of the water layer are combined with the main ethyl acetate solution. The combined solutions are rinsed with brine, dried over sodium sulfate and concentrated under reduced pressure to an oil, 18.1 g. of the 2β-hydroxymethyl compound. An analytical sample has m.p. 116°-118° C.; [α] D -80° (CHCl 3 ); infrared spectral absorptions at 3460, 1735, 1708, 1600, 1580, 1490, 1325, 1315, 1280, 1205, 1115, 1090, 1070, 1035, 1025, 730, and 720; and NMR peaks at 2.1-3.0, 3.58, 4.83-5.12, 5.2-5.45, 7.15-7.55, and 7.8-8.0 δ.
D. The title 2β-carboxaldehyde compound is prepared as follows. To a mixture of 250 ml. of dichloromethane and Collins' reagent prepared from chromium trioxide (10.5 g.) and 16.5 ml. of pyridine, cooled to 0° C., a cold solution of the hydroxymethyl compound of step C (5.0 g.) in 50 ml. of dichloromethane is added, with stirring. After 7 min. of additional stirring, the title intermediate is used directly without isolation (see Example 1).
Following the procedure of Preparation 1, but replacing that optically active formula-XIII iodolactone with the racemic compound of that formula and the mirror image thereof (see E. J. Corey et al., J. Am. Chem. Soc. 91, 5675 (1969)) there is obtained the racemic compound corresponding to formula XVII.
Preparation 2 3α-Benzoyloxy-5α-hydroxy-2β-(3-oxo-4-phenoxy-trans-1-butenyl)-1α-cyclopentaneacetic Acid, γ-Lactone (Formula XVIII: R 4 and R 5 are hydrogen, R 9 is benzoyl, and s is zero).
Refer to Chart B.
A. There is first prepared dimethyl3-phenoxyacetonylphosphate. A solution of dimethyl methylphosphonate (75 g.) in 700 ml. of tetrahydrofuran is cooled to -75° C. under nitrogen and n-butyllithium (400 ml. of 1.6 molar solution in hexane) is added, keeping the temperature below -55° C. The mixture is stirred for 10 min. and to it is slowly added 2-phenoxyacetyl chloride (44 g.), again keeping the temperature below -55° C. The reaction mixture is stirred at -75° C. for 2 hours, then at about 25° C. for 16 hours. The mixture is acidified with acetic acid and concentrated under reduced pressure. The residue is partioned between diethyl ether and water, and the organic phase is dried and concentrated to the above-named intermediate, 82 g. Further treatment by silica gel chromatography yields an analytical sample having NMR peaks at 7.4-6.7 (multiplet), 4.78 (singlet), 4.8 and 4.6 (two singlets), and 3.4-3.04 (doublet) δ.
B. The phosphonate anion (ylid) is then prepared as follows. Dimethyl 3-phenoxyacetonylphosphonate (step A, 9.3 g.) is added in portions to a cold (5° C.) mixture of sodium hydride (1.75 g. of 50% in 250 ml. of tetrahydrofuran, and the resulting mixture is stirred for 1.5 hours at about 25° C.
C. To the mixture of step B is added the cold solution of the formula-XVII 2β-carboxaldehyde of Preparation 1, and the resulting mixture is stirred about 1.6 hours. Then 3 ml. of acetic acid is added and the mixture is concentrated under reduced pressure. A solution is prepared from the residue in 500 ml. of ethyl acetate, washed with several portions of water and brine, and concentrated under reduced pressure. The residue is subjected to silica gel chromatography, eluting with ethyl acetate-Skellysolve B (isomeric hexanes) 3:1). Those fractions shown by TLC to be free of starting material and impurities are combined and concentrated to yield the title compound, 1.7 g.; NMR peaks at 5.0-8.2 and 4.7 (singlet) δ.
Following the procedure of Preparation 2, but replacing the optically active formula-XVII aldehyde with the racemic aldehyde obtained after Preparation 1, there is obtained the racemic 3-oxo-4-phenoxy-1-butenyl compound corresponding to formula XVIII.
Following the procedure of Preparation 2, but replacing 2-phenoxyacetyl chloride with each of the following acid esters: ##STR41##
When a phosphonate contains an asymmetric carbon atom, e.g. when the methylene between the carbonyl and the --O-- is substituted with only one methyl or ethyl group, the phosphonate exists in either of two optically active forms (+ or -) or their racemic (dl) mixture. An optically active phosphonate is obtained by starting with an appropriate optically active isomer of a phenoxy or substituted-phenoxy aliphatic acid. Methods of resolving these acids are known in the art, for example by forming salts with an optically active base such as brucine, separating the resulting diastereomers, and recovering the acids.
Following the procedure of Preparation 2, employing the optically active aldehyde XVII of that example, each optically active phosphonate yields a corresponding optically active formula-XVIII γ-lactone.
Likewise following the procedure of Preparation 2, employing the optically active aldehyde XVII of that preparation, each racemic phosphonate obtained yields a pair of diastereomers, differing in their stereochemistry at the fourth carbon of the phenoxy-terminated side-chain. These diastereomers are separated by conventional methods, e.g. by silica gel chromatography.
Again following the procedure of Preparation 2, employing the optically active aldehyde XVII of that example, each of the optically inactive phosphonates obtained from the list of carboxy acid esters above wherein there is no asymmetric carbon atom, i.e. R 4 and R 5 are the same, yields a corresponding optically active formula-XVIII γ-lactone.
Replacing the optically active aldehyde XVII with the racemic aldehyde obtained after Preparation 1, and following the procedure of Preparation 2 using each of the optically active phosphonates described above, there is obtained in each case a pair of diastereomers which are separated by chromatography.
Likewise following the procedure of Preparation 2, employing the racemic aldehyde with each of the racemic phosphonates described above, there are obtained in each case two pairs of 3-oxo-4-phenoxy (or substituted-phenoxy) racemates which are separated into pairs of racemic compounds by methods known in the art, e.g. silica gel chromatography.
Again following the procedure of Preparation 2, employing the racemic aldehyde with each of the optically active phosphonates described above, there are obtained in each case a diastereomeric product corresponding to formula XVIII.
Preparation 3 3α-Benzoyloxy-5α-hydroxy-2β-(3α-hydroxy-3-methyl-4-phenoxy-trans-1-butenyl-1α-cyclopentaneacetic Acid, γ-Lactone (Formula XXXI: M 6 is ##STR42##
To a stirred solution of 1.0 g. of 3αs-benzoyloxy-5α-hydroxy-2β-(3-oxa-4-phenoxy-trans-1-butenyl)-1α-cyclopentaneacetic acid, γ-lactone in 75 ml. of tetrahydrofuran at -78° C. under nitrogen is added dropwise 15 ml. of an ethereal solution of 3M methyl magnesium bromide. The solution becomes heterogeneous. After two hours a TLC (50% ethyl acetate-Skellysolve B) of an aliquot quenched with ether-ammonium chloride shows the reaction to be complete. To the mixture at -78° C. is added dropwise 15 ml. of saturated aqueous ammonium chloride. The resulting mixture is allowed to warm with stirring to ambient temperatures. The mixture is then diluted with diethyl ether and water, equilibrated, and separated, the aqueous layer is extracted three times more with diethyl ether. The organic extracts are combined, washed with brine, dried over sodium sulfate, and evaporated to give the product.
Following the procedure of Preparation 3, but using each of the formula-XVIII lactones, described in the text following Preparation 2 above, there are obtained the lactones of the formula ##STR43## wherein M 6 is as defined in Preparation 3.
Following the procedure of Preparation 3, but using a racemic lactone described following Preparation 2, there are obtained corresponding racemic 3-methyl products.
Preparation 4 3α,5α-dihydroxy-2β-(3α-hydroxy-3-methyl-4-phenoxy-trans-1-butenyl)-1α-cyclopentaneacidaldehyde, γ-lactol bis(tetrahydropyranyl) ether (Formula XXXIV: wherein M 7 is ##STR44## ˜ is α or β, and R 10 is THP) and the 3β-hydroxy epimer, (Formula XXXIV: wherein M 7 is ##STR45## and Q, ˜, and R 10 are as defined above herein).
A. With reference to Chart E the formula-XXXI compound (the compound of Preparation 3, 1.3 g.) in 22 ml. of anhydrous methanol is stirred with potassium carbonate (0.48 g.) for one hour at about 25° C. and 15 ml. of chloroform is added and the solvent removed under reduced pressure. A solution of the residue in 70 ml. of chloroform is shaken with 10 ml. of water containing potassium hydrogen sulfate (0.5 g.), then with the brine, and concentrated. The residue is washed with several portions of Skellysolve B (isomeric hexanes) and dried to yield the formula-XXXII compound, 3α,5α-dihydroxy-2β(3α-hydroxy-3-methyl-4-phenoxy-trans-1-butenyl)-1α-cyclopentaneacetic acid, γ-lactone, and its 3-hydroxy epimer, 0.4 g.
B. The formula-XXXII compound from part A above is converted to the formula-XXXIII bis(tetrahydropyranyl) ether by reaction with 0.8 ml. of dihydropyran in 10 ml. of dichloromethane in the presence of pyridine hydrochloride (about 0.03 g.). In about 2.5 hours the mixture is filtered and concentrated to the formula-XXXIII product, 0.6 g.
C. The title compound is prepared as follows. Diisobutylaluminumhydride (4.8 ml. of a 10 percent solution in toluene) is added dropwise to a stirred solution of the above formula-XXXIII bis(tetrahydropyranyl) ether from part B above in 8 ml. of toluene cooled to -78° C. Stirring is continued at -78° C. for 0.5 hours whereupon a solution of 3 ml. of tetrahydrofuran and b 1 ml. of water is added cautiously. After the mixture warms to 25° C. it is filtered and the filtrate is washed with brine, dried, and concentrated to the mixed alpha and beta hydroxy isomers of the formula-XXXIV title compound.
Following the procedure of Preparation 4, each of the optically active or racemic compounds corresponding to formula XXXI described the following Preparation 3 is transferred to an optically active or racemic compound corresponding to formula XXXIV. There are thus obtained both 3α- and 3β-hydroxy isomers.
Further, using the various phenoxy substituted and/or 16-alkyl substituted formula-XXXI intermediates provided herein following Preparation 3, there are prepared, following the procedures of Preparation 4, the following formula-XXXIV compounds: ##STR46## wherein M 7 is as defined in Preparation 4.
Preparation 5 3α-Benzoyloxy-5α-hydroxy-2β-(3α-hydroxy-4-phenoxy-trans-1-butenyl)-1α-cyclopentaneacetic Acid, γ-Lactone (Formula XIX: R 9 is benzoyl, Q is ##STR47## or the 3β-hydroxy epimer (Formula XIX: R 9 is benzoyl, Q is ##STR48##
Refer to Chart B. A solution containing ketone XVIII (Preparation 2, 2.7 g.) in 14 ml. of 1,2-dimethoxyethane is added to a mixture of zinc borohydride, prepared from zinc chloride (anhydrous, 4.9 g.) in sodium borohydride (1.1 g.) in 48 ml. of dry 1,2-dimethoxyethane, with stirring and cooling to -10° C. Stirring is continued for 2 hours at 0° C., and water (7.8 ml.) is cautiously added, followed by 52 ml. of ethyl acetate. The mixture is filtered, and the filtrate is separated. The ethyl acetate solution is washed with brine, dried over sodium sulfate, and concentrated under reduced pressure to a mixture of the corresponding formula-XVIII alpha and beta isomers. The compounds are chromatographed on silica gel, eluting with ethyl acetate, to separate the alpha and beta isomers of the formula XIX compounds.
Following the procedures of Preparation 5, but using the substituted-phenoxy and/or 4-methyl substituted ketones of formula XVIII which are shown herein following Preparation 2, the following optically active lactones are obtained: ##STR49##
Preparation 6 3α-Benzoyloxy-5α-hydroxy-2β-(3α-methoxy-4-phenoxy-trans-1-butenyl)-1α-cyclopentaneacetic Acid γ-Lactone (Formula XXVIII: M 5 is ##STR50##
and R 9 is benzoyl) or its 3β-methoxy epimer (Formula XXVIII: M 5 is ##STR51##
and R 9 is benzoyl).
Refer to Chart D where formulas for compounds XIX through XXX are shown. A mixture of the formula-XIX alpha hydroxy compound (Preparation 5, 2.0 g.), silver oxide (4.0 g.), and 50 ml. of methyl iodide is stirred and heated at reflux for 68 hours. The mixture is cooled and filtered, and the filtrate concentrated to an oil, 2.0 g. Separation by silica gel chromatography, eluting with 35% ethyl acetate Skellysolve B and combining those fractions shown by TLC to contain the product free of starting material and impurities, yields the formula XXVIII title compound as an oil.
Following the procedures of Preparation 6 and using each of the optically active or racemic formula-XIX hydroxy compounds following Preparation 5, is transformed to the corresponding optically active formula XXVIII methyl ether compound or racemate consisting of that compound and its mirror image.
Preparation 7 3α,5α-Dihydroxy-2β-(3α-methoxy-4-phenoxytrans-1-butenyl)-(1α-cyclopentaneacetaldehyde, λ-lactol, tetrahydropyranyl ether (Formula XXIX: M 5 is ##STR52## ˜ is alpha or beta, and R 10 is THP).
Refer to Chart D.
A. The formula-XXVIII benzoyloxy compound (1.9 g.) and anhydrous potassium carbonate (0.68 g.) in 25 ml. of dry methanol is stirred for one hour with extraction of moisture. Chloroform (25 ml.) is added and the mixture is filtered. The filtrate is concentrated to an oil which is taken up in chloroform (50 ml.). The solution is washed with brine, dried over magnesium sulfate, and concentrated to an oil. Separation by silica gel chromatography, eluting with 40 percent ethyl acetate-SSB and combining these fractions shown by TLC to contain the product free from starting material impurities, yields the deacylated compound.
B. The tetrahydropyranyl (THP) ether is prepared as follows
A mixture of the compound from part A above (2.35 g.), dihydropyran (3.5 g.), and p-toluenesulfonic acid (about 0.01 g.) in 150 ml. of dichloromethane is stirred for 30 minutes. The mixture is washed twice with sodium carbonate (10 percent) solution, and brine, and dried over magnesium sulfate. Concentration under reduced pressure yields the THP ether.
C. The formula-XXIX lactol is prepared as follows
To the solution of the above THP ether in 150 ml. of dry toluene is added with stirring, protected from air with nitrogen, a solution of 105 ml. of diisobutylaluminumhydride (10 percent in toluene) for about 35 min. at about -65° C. Stirring is continued for 30 min., with cooling. The cooling bath is removed, and the mixture of 48 ml. of tetrahydrofuran (THF) and 29 ml. of water is added dropwise over 20 min. The mixture is filtered and the filtrate is washed with brine and dried over magnesium sulfate. Concentration under reduced pressure yields the title compound as an oil.
Following the procedure of Preparations 5, 6, and 7, but using as starting materials the compounds described in the text following preparation 5 there are prepared the 3α- or 3β-methoxy lactols: ##STR53##
Preparation 8 (6-carboxyhexyl)triphenylphosphonium bromide.
A mixture of 63.6 g. of 7-bromoheptanoic acid in 80 g. of triphenylphosphine, and 300 ml. of acetonitrile is refluxed for 68 hours. Then 200 ml. of acetonitrile is removed by distillation. After the remaining solution has cooled to room temperature, 300 ml. of benzene is added with stirring. After adding a seed crystal, the mixture is allowed to stand overnight. The solid which separated is collected by filtration giving 134.1 g. of the product as white prisms, melting point 185°-187°. A portion is recrystallized from methanol-ether affording white prisms, melting point 185°-187°. The infrared spectrum shows absorptions at 2850, 2570, 2480, 1710, 1585, 1485, 1235, 1200, 1185, 1160, 1115, 1000, 755, 725, and 695 cm. -1 NMR peaks are observed at 1.2-1.9, 2.1-2.6, 3.3-4.0, and 7.7-8.0 δ.
Preparation 9 p-Benzamidophenol ##STR54##
A solution of p-hydroxyaniline (20 g.) in 200 ml. of pyridine is treated with benzoic anhydride (20 g.). After 4 hours at about 25° C., the mixture is concentrated under reduced pressure and the residue is taken up in 200 ml. of hot methanol and reprecipitated with 300 ml. of water. The product is recrystallized from hot acetonitrile as white crystals, 8.5 g., melting point 218.0°-218.5° C.
Preparation 10 p-(p-Acetamidobenzamido)phenol ##STR55##
A solution of p-acetamidobenzoic acid (12.5 g.) in 250 ml. of tetrahydrofuran is treated with triethylamine (11.1 ml.). The mixture is then treated with isobutylchloroformate (10.4 ml.) and, after 5 min. at about 25° C., with p-aminophenol (13.3 g.) in 80 ml. of dry pyridine. After 40 min. the crude product is obtained by addition of 2 liters of water. The product is recrystallized from 500 ml. of hot methanol by dilution with 300 ml. of water as white crystals, 5.9 g., melting point 275.0°-277.0° C.
Example 1 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α, Methyl Ester (Formula I: wherein ˜ is alpha, g is 3, R 1 is methyl, M 3 is ##STR56##
R 4 and R 5 are hydrogen, and s is 0).
Refer to Chart E.
A. (4-carboxybutyl)triphenylphosphonium bromide (E. J. Corey et al., J. Am. Chem. Soc. 94, 5677 (1969)) (4.43 g.) is added to a solution of sodio dimethylsulfinylcarbanide prepared from sodium hydride (57 percent, 0.84 g.) and 14 ml. of dimethylsulfoxide (DMSO). To this reagent is added dropwise a solution of the formula-XXXIV lactol of Preparation 4 in 6 ml. of DMSO. The mixture is stirred at about 25° C. for 2 hours, then diluted with 80 ml. of benzene. To the mixture is added, with stirring, a solution of potassium hydrogen sulfate (4.1 g.) in 20 ml. of water. The organic layer is separated, washed with water, dried, and concentrated under reduced pressure. The residue is triturated with diethyl ether and cooled to 10° C. The liquid residue after evaporation is chromatographed on silica gel eluting with chloroform-methanol (10:1) and combining those fractions showed by TLC to contain the product free of starting material and impurities.
B. A solution of the bis(tetrahydropyranyl)ether of part A above (0.37 g.) in 1.5 ml. of acetonitrile is mixed with 15 ml. of 66 percent acetic acid. The mixture is heated to about 46° C. for 1.5 hours and then concentrated under reduced pressure. The residue is taken up in toluene and again concentrated. The residue is chromatographed on silica gel eluting with ethyl acetate-acetone-water (8:5:1). Those fractions shown by TLC to contain the deetherified product free from starting material and impurities are combined and concentrated to yield a mixture of the title compound and its 15-epimer.
C. A solution of diazomethane (about 0.5 g.) in 25 ml. of diethyl ether is added to a solution of the product of Part B above in 25 ml. of a mixture of methanol and diethylether (1:1). After the mixture stands at about 25° C. for 5 minutes, it is concentrated under reduced pressure to yield the methyl ester of the compound of Part B above. The 15α-epimer, the title compound of this example, is then separated from the 15β-epimer using high pressure liquid chromatography (HPLC).
Example 2 15-epi-15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α, Methyl Ester: (Formula I: wherein ˜ is alpha, g is 3, R 1 is methyl, M 3 is ##STR57##
R 4 and R 5 are hydrogen, and s is 0).
Following the procedure of Example 1, the title compound of this example is obtained as from the HPLC chromatographic separation performed in part C of Example 1.
Example 3 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α (Formula I: wherein ˜ is alpha, g is 3, R 1 is hydrogen, M 3 is ##STR58##
R 4 and R 5 are hydrogen, and s is 0).
Aqueous potassium hydroxide solution (45 percent, 0.9 ml.) is added to a solution of the compound of Example 1 (288 mg.) in a mixture of 6.8 ml. of methanol and 2.2 ml. of water under nitrogen. The resulting solution is stirred 2 hours at 25° C. and is then poured into several volumes of water. The aqueous mixture is extracted with ethyl acetate, acidified with 3M hydrochloric acid, saturated with sodium chloride, and then extracted repeatedly with ethyl acetate. The latter ethyl acetate extracts are combined, washed successively with water and saturated aqueous sodium chloride solution, dried with anhydrous sodium sulfate, and evaporated under reduced pressure. The residue so obtained comprises the title compound of this example in essentially pure form.
Example 4 15-epi-15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α (Formula I: wherein ˜ is alpha, g is 3, R 1 is H, M 3 is ##STR59##
R 4 and R 5 are hydrogen, and s is 0).
Following the procedure of Example 3, using as starting material the compound of Example 1, the title compound of this example is prepared.
Using the procedure of Examples 1 and 3, the following 15-methyl-PGF 2 α -type compounds and their corresponding methyl esters are prepared from the lactol starting material of the formula:
______________________________________ ##STR60## 15-Methyl-PGF.sub.2α,Example Z.sub.3 Methyl Ester______________________________________ ##STR61## 16-methyl-16- phenoxy-18,19,20- trinor6 ##STR62## 16-(o-chlorophen- oxy)-17,18,19,20- tetranor7 ##STR63## 16-methyl-16-(o- chlorophenoxy)- 18,19,20-trino r8 ##STR64## 16-(m-chlorophen- oxy)-17,18,19,20- tetranor9 ##STR65## 16-methyl-16-(m- chlorophenoxy)- 18,19,20-trino r10 ##STR66## 16-(p-chlorophen- oxy)17,18,19,20- tetranor11 ##STR67## 16-methyl-16-(p- chlorophenoxy- 18,19,20-trinor .12 ##STR68## 16-(o-fluorophen- oxy)-17,18,19,20- tetranor13 ##STR69## 16-methyl-16-(o- fluorophenoxy- 18,19,20-trinor14 ##STR70## 16-(m-fluorophen- oxy)-17,18,19,20- tetranor15 ##STR71## 16-methyl-16-(m- fluorophenoxy- 18,19,20-trinor16 ##STR72## 16-(p-fluorophen- oxy)-17,18,19,20- tetranor-PG F.sub.2α17 ##STR73## 16-methyl-16-(p- fluorophenoxy- 18,19,10-trinor PGF.sub.2α18 ##STR74## 16-(o-trifluoro- methylphenoxy)- 17,18,19,20-tr i- nor-PGF.sub.2α19 ##STR75## 16-methyl-16-(o- trifluoromethyl- phenoxy)-18,1 9,20- trinor-PGF.sub.2α20 ##STR76## 16-(m-trifluoro- methylphenoxy)- 17,18,19,20-te tra- nor-PGF.sub.2α21 ##STR77## 16-methyl-16-(m- trifluoromethyl- phenoxy)-18,1 9,20- trinor-PGF.sub.2α22 ##STR78## 16-(p-trifluoro- methylphenoxy)- 17,18,19,20-te tra- nor-PGF.sub.2α23 ##STR79## 16-methyl-16-(p- trifluoromethyl- phenoxy)-18,1 9,20- trinor-PGF.sub.2αwherein M.sub.7 is ##STR80##
Following the procedures of Examples 2 and 4, 15-epi-15-methyl-PGF 2 α -type free acids and methyl esters are prepared using as intermediates the lactols used for the preparation of Examples 5-23. Accordingly, for each and every one of the 15α-hydroxy compounds of Examples 5-23 there are prepared corresponding 15-epi compounds, comprising Examples 24-42.
Example 43 2a,2b-Dihomo-15-methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α, Methyl Ester (Formula I: wherein ˜ is alpha, g is 5, R 1 is methyl, M is ##STR81##
R 4 and R 5 are hydrogen, and s is 0).
Following the procedure of Example 1, but using (6-carboxyhexyl)triphenylphosphonium bromide (Preparation 8) in place of (4-carboxybutyl)triphenylphosphonium bromide the title compound of this example is prepared.
Example 44 2a,2b-Dihomo-15-methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α (Formula I: wherein ˜ is alpha, g is 5, R 1 is hydrogen, M is ##STR82##
R 4 and R 5 are hydrogen, and s is 0).
Following the procedure of Example 3, but using the compound of Example 43 in place of the compound of Example 1, the title compound of this example is prepared.
The 15-epimers of the compounds of Examples 43 and 44, that is the free acid or methyl ester of 2a,2b-dihomo-15-epi-15-methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 .alpha., are prepared by the procedures of Examples 2 and 4 from the same lactol starting materials of Examples 2 and 4 but using the (6-carboxyhexyl)triphenylphosphonium bromide. These 15(R)-epimers thus are the compounds of Examples 45 and 46.
There are prepared further 2a,2b-dihomo-PGF 2 α -type compounds using the lactol starting material of Examples 5 through 23, respectively. Reaction in turn of each of these lactols with (6-carboxyhexyl)triphenylphosphonium bromide yields a corresponding 2a,2b-dihomo-15-methyl-PGF 2 α -type compound. Accordingly, each of the lactols of Examples 5-23 yield in free acid or methyl ester form a corresponding 2a,2b-dihomo-PGF 2 α -type product. These compounds thus provide Examples 47-65.
Following the procedure for Examples 45 and 46, but using the lactol starting material of Examples 47-65, there are prepared 15-epimers of each of the PGF 2 α -type compounds of Examples 47-65, above. Accordingly, there are provided 2a,2b-dihomo-15-epi-15-methyl-PGF 2 α -type compounds in either the free acid or methyl ester form comprising Examples 66-84.
Example 85 16-Phenoxy-17,18,19,20-tetranor-PGF 2 α, 15-Methyl Ether, Methyl Ester (Formula I: wherein ˜ is alpha, g is 3, R 1 is methyl, M 3 is ##STR83##
R 4 and R 5 are hydrogen, and s is zero).
Following the procedure of Example 1, but using the 3α-methoxy lactol of Preparation 7 in place of the compound of Preparation 4, and omitting the final chromatographic separation carried out in Example 1, title compound of this example is prepared.
Following the procedure described in Example 85, but omitting the esterification with diazomethane, the free acid form of the compound of Example 85 is prepared. Accordingly, 16-phenoxy-17,18,19,20-tetranor-PGF 2 α, 15-methyl ether is provided as Example 86.
Following the procedure of Examples 85 and 86 but using as starting material the 3α-methoxy lactol of Preparation 7 there is prepared in both the free acid and methyl esterform 15-epi-16-phenoxy-17,18,19,20-tetranor-PGF 2 α, 15-methyl ether. These compounds accordingly provide Examples 87 and 88.
Following the procedures of Examples 85 and 86 there are obtained in either free acid or methyl ester form the following PGF 2 α, 15-methyl ether-type compounds using as starting material the 3α-methoxy lactols of Preparation 7 of the formula:
______________________________________ ##STR84##as follows:Ex. Z.sub.4 PGF.sub.2α, Methyl Ether______________________________________89 ##STR85## 16-methyl-16-phen- oxy-18,19,20-trinor90 ##STR86## 16-(o-chlorophenoxy), 17,18,19,20-tetra- nor91 ##STR87## 16-methyl-16-(o- chlorophenoxy- 18,19,20-trinor92 ##STR88## 16-(m-chlorophen- oxy)-17,18,19,20- tetranor93 ##STR89## 16-methyl-16-(m- chlorophenoxy- 18,19,20-trinor94 ##STR90## 16-(p-chlorophen- oxy)-17,18,19,20- tetranor95 ##STR91## 16-methyl-16-(p- chlorophenoxy- 18,19,20-trinor96 ##STR92## 16-(o-fluorophen- oxy)-17,18,19,20- tetranor97 ##STR93## 16-methyl-16-(o- fluorophenoxy)- 18,19,20-trinor98 ##STR94## 16-(m-fluorophen- oxy)-17,18,19,20- tetranor99 ##STR95## 16-methyl-16-(m- fluorophenoxy- 18,19,20-trinor100 ##STR96## 16-(p-fluorophen- oxy)-17,18,19,20- tetranor101 ##STR97## 16-methyl-16-(p- fluorophenoxy- 18,19,20-trinor102 ##STR98## 16-(o-trifluoro- methylphenoxy)- 18,19,20-tetra- nor103 ##STR99## 16-methyl-16-(o- trifluoromethyl- phenoxy)-18,1 9,20- trinor104 ##STR100## 16-(m-trifluoro- methylphenoxy- 17,18,19,20-tetr anor105 ##STR101## 16-methyl-16-(m- trifluoromethyl- phenoxy)-18,19 ,20- trinor106 ##STR102## 16-(p-trifluoro- methyl-phenoxy)- 17,18,19,20-te tra- nor107 ##STR103## 16-methyl-16-(p- trifluoromethyl- phenoxy)-18,19 ,20- trinor______________________________________
Following the procedures of Examples 87 and 88 the 15-epi-PGF 2 α, 15-methyl ether-type compounds are prepared using as lactol starting material the various lactols used in Examples 89-107, respectively. There are accordingly provided 19 15-epi-PGF 2 α, 15-methyl ethers comprising Examples 108-126.
Following the procedures provided in Examples 85-89 there are prepared in both free acid and methyl ester form 2a,2b-dihomo-PGF 2 α, 15-methyl ether compounds in both the 15α and 15β epimeric configurations by using (6-carboxyhexyl)triphenylphosphonium bromide in place of (4-carboxybutyl)triphenylphosphonium bromide. Accordingly, there are provided 40 free acid or methyl ester compounds comprising examples 127-166 from a lactol of the formula ##STR104## wherein ˜ is alpha or beta, as follows:
______________________________________ 2a,2b-Diboro PGF.sub.2α, 15-Ex. Z.sub.4 M Methyl Ether______________________________________127 ##STR105## ##STR106## 16-phenoxy-17 18,19,20-tetra- nor128 ##STR107## ##STR108## 15-epi-16-phen- oxy-17,18,19,20 tetranor129 ##STR109## ##STR110## 16-methyl-16-20- phenoxy-18,19, trinor130 ##STR111## ##STR112## 15-epi-16- methyl-16-phen- oxy-18,19,20- rinor131 ##STR113## ##STR114## 16-(o-chloro- phenoxy)-17,18- 19,20-tetra nor132 ##STR115## ##STR116## 15-epi-16(o- chlorophenoxy)- 17,18,19,20- tetranor133 ##STR117## ##STR118## 16-methyl-16- (o-chlorophen- oxy)-18,19,2 0- trinor134 ##STR119## ##STR120## 15-epi-16- methyl-16-(o- chlorophenoxy)- 8,19,20- trinor135 ##STR121## ##STR122## 16-(m-chloro- phenoxy)-17,18,- 19,20-tetr anor136 ##STR123## ##STR124## 15-epi-16-(m- chlorophenoxy)- 17,18,19,20 - tetranor137 ##STR125## ##STR126## 16-methyl-16- (m-chlorophen- oxy)-18,19,2 0- trinor138 ##STR127## ##STR128## 15-epi-16- methyl-16(o- chlorophenoxy)- 18,19,20- trinor139 ##STR129## ##STR130## 16-(p-chloro- phenoxy)- 17,18,19,20- tetranor140 ##STR131## ##STR132## 15-epi-16-(p- chlorophenoxy)- 17,18,19,20 - tetranor141 ##STR133## ##STR134## 16-methyl-16- (p-chlorophen- oxy)-18,19,2 0- trinor142 ##STR135## ##STR136## 15-epi-16- methyl-16-(p- chlorophenoxy)- 8,19,20- trinor143 ##STR137## ##STR138## 16-(o-fluoro- phenoxy)-17,18,- 19,20-tetr anor144 ##STR139## ##STR140## 15-epi-16-(o- fluorophenoxy)- 17,18,19,20 - tetranor145 ##STR141## ##STR142## 16-methyl-16- (o-fluorophen- oxy)-18,19,2 0- trinor146 ##STR143## ##STR144## 15-epi-16- methyl-16-(o- fluorophenoxy)- 8,19,20- trinor147 ##STR145## ##STR146## 16-(m-fluoro- phenoxy)-17,18,- 19,20-tet ranor148 ##STR147## ##STR148## 15-epi-16-(m- fluorophenoxy)- 17,18,19,20 - tetranor149 ##STR149## ##STR150## 16-methyl-16- (m-fluorophen- oxy)-18,19,2 0- trinor150 ##STR151## ##STR152## 15-epi-16- methyl-16-(m- fluorophenoxy)- 8,19,20-trinor151 ##STR153## ##STR154## 16-(p-fluoro- phenoxy)-17,18,- 19,20,tetr anor152 ##STR155## ##STR156## 15-epi-16-(p- fluorophenoxy)- 17,18,19,20 - tetranor153 ##STR157## ##STR158## 16-methyl-16- (p-fluorphen- oxy)-18,19,20 - trinor154 ##STR159## ##STR160## 15-epi-16- methyl-16-(p- fluorophenoxy)- 8,19,20- trinor155 ##STR161## ##STR162## 16-o-trifluoro- methyl- phenoxy)- 17,18,19,20- tetranor156 ##STR163## ##STR164## 15-epi-16-(o- trifluoro- methyl- phenoxy)-17,18,- 19,20-tetranor157 ##STR165## ##STR166## 16-methyl-16- (o-trifluoro- methyl- phenoxy)- 18,19,20- trinor158 ##STR167## ##STR168## 15-epi-16- methyl-16-o- trifluoro- methyl- phenoxy)-18,19,- 20-trinor159 ##STR169## ##STR170## 16-(m-trifluoro- methyl- phenoxy)- 17,18,19,20- tetranor160 ##STR171## ##STR172## 15-epi-16-(m- trifluoromethyl- phenoxy)- 17,18,- 19,20-tetranor162 ##STR173## ##STR174## 15-epi-16- methyl-16-(m- trifluoromethyl- phenoxy)-18,19,- 20-trinor163 ##STR175## ##STR176## 16-(p-trifluoro- methyl- phenoxy)- 17,18,19,20- tetranor164 ##STR177## ##STR178## 15-epi-16-(p- trifluoromethyl- phenoxy)-1 7,18,- 19,20-tetranor165 ##STR179## ##STR180## 16-methyl-16- (p-trifluoro- methyl- phenoxy)- 18,19,20- trinor166 ##STR181## ##STR182## 15-epi-16- methyl-16-(p- trifluorpmethyl- phenoxy)-18,19,- 20-trinor______________________________________
Example 167 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGE 2 , Methyl Ester (Formula IV: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR183##
g is 3, and s is zero).
A. The compound of Example 1, 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α methyl ester is transformed into its 11-(trimethylsilyl)ether. N-trimethylsilyldiethylamine (1.7 ml.) is added slowly to a mixture of the compound of Example 1 (0.46 g.) and 15 ml. of acetone previously cooled to 31 48° C., and kept under nitrogen. Progress of the reaction is monitored by thin layer chromatography. The reaction temperature is maintained at about -45° C. to -35° C. for 1.5 hours whereupon the mixture is diluted with about 91 ml. of diethyl ether (previously cooled to -78° C.). The solution is washed with 91 ml. of cold saturated sodium bicarbonate solution, and the aqueous phase is washed with ether. The ether extract and washings are washed with brine, dried over sodium sulfate and concentrated to yield the 11-(trimethylsilyl)ether (0.5 g.).
B. A solution of the product of step A of this example (0.66 g.) in 6 ml. of dichloromethane is added to Collins reagent, prepared from chromium trioxide (1.3 g.) and pyridine (2.1 ml.) in 61 ml. of dichloromethane and cooled to 0° C. The mixture is stirred at 0° C. for 5 min. and then at about 25° C. for 10 min., and filtered. The filtrate is concentrated to yield the corresponding PGE 2 -type, 11-(trimethylsilyl)ether (0.6 g.).
C. A solution of the compound of part B of this example (about 0.6 g.) in 33 ml. of methanol is mixed with 16 ml. of water and about 1.6 ml. of acetic acid at about 25° C. is stirred for about 15 min. The mixture is partitioned between diethyl ether and 0.2 M sodium hydrogen sulfate. The ether extract is washed with saturated aqueous sodium bicarbonate, then with brine, dried over sodium sulfate and concentrated to a product containing the title compound of the example (0.46 gm).
The product is subjected to chromatography on silica gel, packed with 75% ethyl acetate in hexane, eluting with ethyl acetate. Those fractions containing the title compound free of starting material and impurities are combined and concentrated to yield the title compound 257 mg.
NMR absorptions are observed at 1.43, 3.63, 3.88, 1.20-4.22, 5.23-5.53, 5.72-5.92, and 6.75-7.55. Infrared absorptions are observed at 3440, 2940, 2920, 2860, 1740, 1600, 1585, 1495, 1455, 1435, 1245, 1170, 1160, 1080, 1045, 975, 755, 735, and 695 cm -1 . The mass spectrum shows base peak absorption at 560.2947 and other peaks at 560, 545, 529, 470, 453 and 309.
Following the procedure of Example 167, but replacing 15-methyl-16-phenoxy-17,18,19-tetranor-PGF 2 α methyl ester with its 15-epimer, the corresponding product is prepared, NMR absorptions are observed at 1.43, 3.63, 3.90, 1.17-4.23, 5.22-5.57, 5.72-5.90, and 6.77-7.57 δ.
Further following the procedure of Example 167, but replacing the title compound with each of the various 15α or 15β-15-methyl-PGF 2 α -type compounds of Examples 2 through 84, there are obtained the corresponding PGE 2 -type compounds. The compounds thus obtained are in either the free acid or methyl ester form. Accordingly, there are obtained the following 15-methyl compounds of either the 15α or 15β configuration, with either the natural carboxy terminated chain length or 2 additional carbon atoms in the carboxy terminated chain length, e.g. 2a,2b-dihomo-PG-type compounds, as described in Examples 2 through 84. These compounds comprise Examples 168-246.
Example 247 16-Phenoxy-17,18,19,20-tetranor-PGE 2 , Methyl Ester, 15-Methyl Ether (Formula IV: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR184##
g is 3, and s is zero).
A. Following the procedure of Example 167, part A, but using as starting material 16-phenoxy-17,18,19,20-tetranor-PGF 2 α, methyl ester 15-methyl ether, the 11-silyl ether derivative of the starting material is prepared.
B. Following the procedure of Example 167, part B, the 9-hydroxy group of the product of part A of this example is transformed into a 9-oxo group. Accordingly, 16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester, 11-silyl ether, 15-methyl ether is prepared.
C. Following the procedure of Example 167, part C, the 11-silyl ether compound of part B of this example is hydrolyzed to yield the title compound.
Following the procedure of Example 247, but using as starting material the 15-methyl ether compounds of Examples 85-166 there are accordingly prepared 15α- or 15β-15-methyl ethers in either free acid or ester form, having carboxy terminated chain lengths of either 7 or 9 carbon atoms. There are accordingly prepared PGE 2 -type compounds comprising Examples 248-326.
Example 327 15-Methyl-16-phenoxy-PGE 1 , Methyl Ester (Formula V: wherein R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR185##
g is 3, and s is zero).
The compound of Example 167, 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester (0.6 g.), 5 percent rhondium-on-alumina catalyst (40 mg.), and 16 ml. of ethyl acetate is stirred under one atmosphere of hydrogen at about 0° C. until substantially all of the starting material has been used, as shown by thin layer chromatography. The mixture is filtered to remove catalysts and the filtrate is concentrated. The residue is chromatographed to yield the title compound.
Example 328 16-Phenoxy-17,18,19,20-tetranor-PGE 1 , Methyl Ester, 15-Methyl Ether (Formula V: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR186##
g is 3, and s is zero).
Following the procedure of Example 327, but using as starting material the compound of Example 247, 16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester 15-methyl ether, there is prepared the title compound of this example.
Following the procedure of Example 327 or 328, but using as starting material the PGE 2 -type compounds of Examples 168-246 or 248-326 there are prepared the corresponding PGE 1 -type compounds.
Example 329 15-Methyl-16-phenoxy-17,18,19,20-tetranor-13,14-dihydro-PGE 1 , Methyl Ester (Formula VI: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR187##
g is 3 and s is zero).
A solution of the compound of Example 167, 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester (100 mg. in 10 ml. of ethyl acetate is shaken with hydrogen at atmosphere pressure at 25° C. in the presence of a 5 percent palladium-on-charcoal catalyst (15 mg.). Two equivalents of hydrogen are used, whereupon the hydrogenation is stopped and the catalyst is removed by filtration. The filtrate is concentrated under reduced pressure and the residue is chromatographed on silica gel, and fractions containing pure product concentrated to give the title compound.
Following the procedure of Example 329, but using as starting material the 15-methyl-PGE 2 -type compounds of Examples 168-247 there are prepared the corresponding 13,14-dihydro-PGE 1 compounds in either free acid or ester form.
Example 330 16-Phenoxy-17,18,19,20-tetranor-13,14-dihydro-PGE 1 , Methyl Ester, 15-Methyl Ether (Formula VI: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR188##
g is 3, and s is zero).
Following the procedure of Example 329, but using as starting material the compound of Example 247, 16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester 15-methyl ether, there is prepared the title compound of this example.
Following the procedure of Example 330, but using as starting material the compound of Examples 248-326, there are prepared the corresponding 13,14-dihydro-PGE 1 -type, 15-methyl ether compounds in either their free acid or methyl ester form.
Example 331 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 β, Methyl Ester (Formula I: ˜ is alpha, R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR189##
g is 3, and s is zero).
Refer to Chart I. A solution of sodium borohydride 300 mg. in 6 ml. of ice-cold methanol is added to a solution of 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester (Example 167, 650 mg.) in 30 ml. of methanol at -20° C. The mixture is stirred for an additional 5 minutes, made slightly acidic with acetic acid and concentrated under reduced pressure. The residue is extracted with dichloromethane and the organic phase is washed with water, chloride, and brine, then dried over sodium sulfate, and concentrated under reduced pressure.
This residue is chromatographed over silica gel wet packed in ethyl acetate, eluting with 2 percent, 4 percent, 7.5 percent, and 10 percent ethanol in ethyl acetate. Those fractions containing the title compound free from starting material and impurities as shown by TLC, are combined and concentrated to yield the title compound of this example or its corresponding PGF 2 α -type compound.
Following the procedure of Example 331, but using as starting material the 15-alkyl-PGE 2 -type compounds of Examples 168 through 246 there are prepared the corresponding 15-methyl-PGF 2 β - or PGF 2 α -type compounds.
Following the procedure of Example 331, but using as starting material either the 15-methyl-PGE 1 -type compounds described in Example 327 and the paragraph following Example 327 or the 15-methyl-13,14-dihydro-PGE 1 -type compounds described in Example 329 and the paragraph following Example 329, there are prepared the corresponding 15-methyl-PGF 1 β - or PGF 1 α - or 13,14-dihydro-PGF 1 β - or PGF 1 α -type compounds.
Example 332 16-Phenoxy-17,18,19,20-tetranor-PGF 2 β, Methyl Ester 15-Methyl Ether (Formula I: ˜ is beta, R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR190##
g is 3, and s is zero).
Following the procedure of Example 331, but using as starting material the compound of Example 247, 16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester, 15-methyl ether, there is prepared the compound of this example or its 9α-isomer.
Following the procedure of Example 332, but using as starting materials the PGE 2 -type, 15-methyl ether compounds of Examples 248-326 there are prepared the corresponding PGF 2 β - or PGF 2 α -type, 15-methyl ether compounds.
Following the procedure of Example 332, but using as starting material either the PGE 1 -type, 15-methyl ether compounds described in Example 328 and the paragraph following Example 328, or the 13,14-dihydro-PGE 1 -type, 15-methyl ether compounds described in Example 330 or in the text following Example 330 there are prepared the corresponding PGF 1 β - or PGF 1 α -type, 15-methyl ether or 13,14-dihydro-PGF 1 β - or PGF 2 α -type, 15-methyl ether compounds.
Example 333 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGA 2 , Methyl Ester (Formula X: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR191##
g is 3, and s is zero).
Refer to Chart I. A solution of the compound of Example 167, 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester (300 mg.), 4 ml. of tetrahydrofuran and 4 ml. 0.5 N hydrochloric acid is left standing at 25° C. for 5 days. Brine and dichloromethane-ether (1:3) are added and the mixture is stirred. The organic phase is separated, dried, and concentrated. The residue is dissolved in ether and the solution is extracted with saturated aqueous sodium bicarbonate. This aqueous phase is acidified with dilute hydrochloric acid and then extracted with dichloromethane. Alternatively pure product is obtained by silica gel chromatography purification of the residue.
Following the procedure of Example 333 but using as starting material the 15-methyl-PGE 2 -type compounds of Examples 168-246, there are prepared the corresponding 15-methyl-PGA 2 -type compounds.
Following the procedure of Example 333, but using as starting material either the 15-alkyl-PGE 1 -type compounds of Example 327 or the paragraph following Example 327, or the 15-methyl-13,14-dihydro-PGE 1 -type compounds of Example 329 or the paragraph following Example 329, there are prepared corresponding 15-methyl-PGA 1 or 13,14-dihydro-PGA 1 -type compounds of this invention.
Example 334 16-Phenoxy-17,18,19,20-tetranor-PGA 2 , Methyl Ester 15-Methyl Ester (Formula X: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR192##
g is 3, and s is zero).
Following the procedure of Example 333, but using as starting material the compound of Example 86, 16-phenoxy-17,18,19,20-tetranor-PGF 2 , methyl ester 15-methyl ether, the title compound of this example is prepared.
Following the procedure of Example 334, but using as starting material the PGE 2 -type, 15-methyl ether compounds of Examples 248-326, there are prepared the corresponding PGA 2 -type, 15-methyl ether type compounds of this invention.
Following the procedure of Example 334, but using as starting material either the PGE 1 -type, 15-methyl ether compounds of Example 328 or the paragraph following Example 328 or the 13,14-dihydro-PGE 1 -type, 15-methyl ether compounds of Example 330 or the paragraph following Example 330, there are prepared corresponding PGA 1 -type, 15-methyl ether or 13,14-dihydro-PGA 1 -type, 15-methyl ether compounds of this invention.
Example 335 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGB 2 , Methyl Ester (Formula VII: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR193##
g is 3, and s is zero).
Refer to Chart I. A solution of 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGE 2 (Example 167, 200 mg.) in 100 ml. of 50 percent aqueous ethanol containing about 1 g. of potassium hydroxide is kept at 25° C. for 10 hours under nitrogen. The solution is then cooled to 10° C., neutralized by the addition of 3 N hydrochloric acid at 10° C. The resulting solution is extracted repeatedly with ethyl acetate, combined with ethyl acetate extracts and are washed with water and then with brine, dried, and concentrated to yield the title compound.
Following the procedure of Example 335, but using as starting material the 15-methyl-PGE 2 -type compounds of Examples 168-246 there are prepared the corresponding 15-methyl-PGB 2 -type compounds of this invention.
Following the procedure of Example 335, but using as starting material either the 15-methyl-PGE 1 -type compounds of Example 327 or the paragraph following Example 327 or the 15-methyl-13,14-dihydro-PGE 1 -type compounds of Example 329 or the paragraph following Example 329, corresponding 15-methyl-PGE 1 or 13,14-dihydro-PGE 1 -type compounds of this invention are prepared.
Example 336 16-Phenoxy-17,18,19,20-tetranor-PGB 2 , Methyl Ester, 15-Methyl-Ether (Formula X: R 1 is methyl, R 4 and R 5 are hydrogen, M 3 is ##STR194##
g is 3 and s is zero).
Following the procedure of Example 335, but using as starting material the compound of Example 247, 16-phenoxy-17,18,19,20-tetranor-PGE 2 , methyl ester 15-methyl ether, there is prepared the title compound of this invention.
Following the procedure of Example 336, but using as starting material the PGE 2 -type, 15-methyl ether compounds of Examples 248-326, the corresponding PGB 2 -type, 15-methyl ether compounds are prepared.
Following the procedure of Example 336, but using as starting material either the PGE 1 -type, 15-methyl ether compounds of Example 328 or the paragraph following Example 328, or the 13,14-dihydro-PGE 1 -type, 15-methyl ether compounds of Example 330 or the paragraph following Example 330, there are prepared corresponding PGB 1 - and 13,14-dihydro-PGE 1 -type, 15-methyl ether compounds of this invention.
Example 337 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α, Sodium Salt (Formula I: ˜ is alpha, R 1 is sodium, R 4 and R 5 are hydrogen, M is ##STR195##
g is 3, and s is 0).
A solution of 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α (Example 2, 100 mg.) in 50 ml. of water-ethanol mixture (1:1) is cooled to 5° C. and neutralized with an equivalent amount of 0.1 N aqueous sodium hydroxide solution. The neutral solution is concentrated to residue of the title compound.
Following the procedure of Example 337, but using potassium hydroxide, calcium hydroxide, the corresponding salts of 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α are obtained.
Following the procedure of Example 337, but using as starting material the PGF.sub.α -, PGF.sub.β -, PGA-, and PGB-type free acids of the examples hereinabove, there are obtained corresponding sodium, potassium, calcium, trimethyl ammonium, and benzyl trimethyl ammonium salts thereof.
EXAMPLE 338 p-Acetamidophenyl Ester of 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α.
A solution of 15-methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α the compound of Example 2, in acetone is treated at -10° C. with twice the stoichiometric amount of triethylamine as PG analog, and is treated with an equal quantity of isobutylchloroformate, whereupon triethylamine hydrochloride is precipitated. After 5 minutes the mixture is treated with several fold stoichiometric excess (over the prostaglandin analog) of p-acetamidophenol in pyridine for 3 hours at 25° C. The solvent is removed under reduced pressure and the residue is taken up in acetonitrile and again concentrated. The crude residue is subjected to silica gel chromatography, eluting with ethyl acetate and methanol (90:10). The residue obtained by concentration of selected fractions, is the title compound of this example.
Following the procedure of Example 338, but using in place of the prostaglandin analog any of the free acid PGF.sub.α -, PGF.sub.β -, PGA-, PGB- or PGE-type compounds of this invention, there are prepared the corresponding p-acetamidophenol esters.
Following the procedure of Example 338 and using any of the prostaglandin-type free acids described in the previous paragraph, and using, in place of p-acetamidophenol, a phenol or naphthol selected from the group consisting of p-(p-acetamidobenzamido)phenol, p-benzamidophenol, p-hydroxyphenylurea, p-hydroxybenzaldehydesemi-carbazone, and 2-naphthol, the corresponding substituted phenyl or naphthyl esters are obtained.
Example 339 15-Methyl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α, Methyl Ester, or its 15-epimer. A. To a stirred solution of 26.3 gm. of the reaction product of Preparation 4, part B in 398 ml. of dry toluene under nitrogen at -78° C. is added 150 ml. of 20% diisobutylaluminum hydride in hexane. After one hour an additional 150 ml. of the above hexane solution is added. After 15 hours the reaction is quenched by addition of 750 ml. of saturated ammonium chloride. After warming, the reaction product is filtered, washed with ethyl acetate and water, and the organic extracts, then washed with brine, dried, and concentrated (employing a benzene azeotrope) to yield 27.7 g. of lactol.
B. A mixture of 24.4 g. of 50% sodium hydride in mineral oil and 818 ml. of dimethylsulfoxide is stirred under nitrogen at 70° C. After one hour and cooling to 15° C. (4-carboxybutyl)triphenylphosphonium bromide is added.
Thereafter 27.7 g. of the lactol of part A is added, monitoring the progress of the reaction with thin layer chromatography. On completion, the reaction mixture is quenched by addition of 1.2 l. of 2M sodium bisulfate, diethyl ether, and ice water. The resulting mixture is extracted with diethyl ether, and thereafter the organic extract is extracted with 200 ml. of 1N sodium hydroxide, and water. The basic aqueous extract above is then extracted with diethyl ether, and all organic extracts then combined and concentrated to yield 22 g. of an oil.
C. The crude product (part B) is then esterified by dissolving this product in ether and methanol (1:1) and treating with excess diazomethane. The resulting solution is then concentrated under reduced pressure yielding 22 gm. of an oil.
D. Crude product from part C, above, is chromatographed on silica gel, eluting with ethyl acetate and Skellysolve B (isomeric hexanes) yielding 10.9 gm. of pure 15(RS) product. Then, 9.0 gm. of the pure 15(RS) product are subjected to high pressure liquid chromatographic separation, eluting with 30% acetone in dichloromethane, at a flow rate of 6 ml/min. The title compound is obtained in a yield of 0.67 gm. and the 15-epi compound in a yield of 0.56 gm.
Title compound shows mass spectral base peak at 634.3541 and other peaks at 634, 619, 603, 544, 527, 513, 437, and 217. NMR absorptions are observed at 1.38, 3.62, 3.83, 3.57-4.47, 5.07-5.82, and 6.75-7.67 δ. Infrared absorption is observed at (cm -1 ) 3400, 3060, 3000, 1735, 1600, 1585, 1500, 1455, 1430, 1370, 1300, 1290, 1245, 1170, 1155, 1120, 1080, 1045, 875, 755, and 690.
The 15-epimer shows mass spectral base peak absorption at 527.3044 and other peaks at 634, 619, 544, 527, 455, 437, and 217. NMR absorptions are observed at 1.38, 1.32-3.28, 3.63, 3.85, 3.60-4.35, 5.20-5.83, and 6.72-7.65 δ.
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Prostaglandin E-, F.sub.α -, F.sub.β -, A-, and B-type compounds are disclosed with intermediates and with processes for making them. These compounds differ from the prostaglandins in that they are substituted at C-16 with a phenoxy or substituted phenoxy, and have a lower alkyl group in place of the hydrogen at C-15 and/or a lower alkoxy group in place of the hydroxy group at C-15. These compounds are useful for a variety of pharmacological purposes, including antiulcer, inhibition of platelet aggregation, increase in nasal patency, labor induction at term, and wound healing.
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TECHNOLOGY FIELD
[0001] This Invention relates to a unit brake with a regular brake part and a spring brake part.
BACKGROUND TECHNOLOGY
[0002] A cylinder device and a brake body attached to this cylinder device are equipped as a unit brake for vehicle braking, to activate the cylinder device, and bring a brake shoe retaining relative displaceability versus the brake body into contact with the vehicle wheel, to brake the rotation of the vehicle wheel. For the cylinder device in this type of unit brake, for example, in brake devices for rail vehicles, cylinder devices are known that can be activated with both a regular brake part activated with compressed air (compressed fluid) used in normal operations, and a spring brake part activated by a spring force even without use of compressed air, used for stopping the vehicle over a long time (see Patent Citation 1). In the cylinder device disclosed in Patent Citation 1, the regular brake part has a rod protruding and has installed a first piston used in opposition to a first pressure chamber and first spring, and the spring brake part has a rod penetrating and has installed a second piston used in opposition to a second pressure chamber and second spring. In addition, compressed air is supplied to the first pressure chamber, to move the first piston in the brake direction, in resistance to the first spring added force, and furthermore, compressed air is exhausted from the second pressure chamber, to move the second piston in the brake direction, using the second spring added force.
[0003] In addition, in the above-mentioned cylinder device, a clutch function is installed that links the rod and second piston are linked, and releases that link, switching between transmitting or blocking the spring brake part added force. In this clutch mechanism, rotatability is supported versus the second piston, and a nut member screwed into the rod is installed. Moreover, this clutch mechanism is configured so as to move from a state where compressed air is supplied to the second pressure chamber to an exhaust state, and the nut member moves together with the second piston versus the rod, by the second spring added force, so that the rod and second piston are linked to form a linked state. By contrast, in the state where compressed air is supplied to the second pressure chamber, this clutch mechanism is configured so that the link between the rod and second piston is released, to form a non-linked state. In this cylinder device, the clutch mechanism moves to the above-mentioned link state, and is designed so that the convex-concave teeth in the nut member in the clutch mechanism, and in the sleeve member that is the opposite-side member, are linked by mutual gripping, and the brake force is maintained in the spring brake part.
ADVANCED TECHNOLOGY CITATION
Patent Citation
[0004] Patent Citation 1: Laid Open No. 2008-101766 Publication
[0005] Patent Citation 2: Laid Open No. 2010-164193 Publication
SUMMARY OF INVENTION
[0006] Issues that Invention Attempts to Solve
[0007] In the above-mentioned clutch mechanism in the cylinder device disclosed in Patent Citation 1 (Laid Open No. 2008-101766 Publication), when the nut member moves together with the second piston, the forward tip parts of the convex-concave teeth in the nut member and sleeve member come into contact with each other first. At this time, contact resistance with the sleeve member that obstructed displacement of the rotation direction easily causes the nut rotation to be stopped. As a result, there are cases where the convex-concave teeth in the nut member and sleeve member do not fully grip all the way to the back, and the rod and second piston remain linked with only the forward tip parts gripped together. If left standing in this kind of linked state, the compressed air in the first pressure chamber of the regular brake part is steadily outgassed, and activation of the first pressure chamber causes the added force of the first piston to weaken, then the brake shoe or the carriage structural member formed from composite materials that is deflected by this added force, overlaps with the force from the spring element installed on the carriage compressed or expanded by this added force, leading to a reaction force from the brake shoe side, and this reaction from the brake shoe side causes the first piston to be pushed back slightly in a direction opposite to the brake direction, and at the same time, the rod formed as a unit with the first piston is also pushed back slightly in a direction opposite to the brake direction, so that the clutch mechanism gripped part, which had only been gripped at the forward tips only, comes completely loose, and the brake force for the spring brake part used as the parking brake, etc., is unintentionally relaxed. In particular, this tendency becomes much more notable when the first piston added force is large while parked because the reaction force from the brake shoe side also grows larger.
[0008] In addition, while use of the unit brake listed in Patent Citation 2 (Laid Open No. 2010-164193 Publication) solves the above-mentioned issue, there is a problem in that it cannot be exchanged as is for existing vehicles where the Patent Citation 1 (Laid Open No. 2008-101766 Publication) unit brake is used, because of an installation space problem. Furthermore, since the bearing used in the clutch mechanism of the unit brake listed in Patent Citation 2 (Laid Open No. 2010-164193 Publication) is used inside a compressed air atmosphere generated by a compressor, there is a problem of adverse effects due to humidity, etc. In particular, the said problem appears quite notably in cases of vehicles used overseas where dehumidification devices are not installed.
[0009] In a unit brake equipped with a cylinder device with a clutch mechanism installed for switching between transmission and blocking the added force of the spring brake part, this Invention takes the above-mentioned situation into consideration to set an objective to provide a unit brake that can prevent unintentional relaxation of the brake force by the spring brake part due to disengagement of the clutch mechanism gripping part, that is a size enabling replacement of existing items, and that can maintain the clutch mechanism bearing performance even during long-term use.
[0010] Method for Resolving the Issue
[0011] (1) The unit brake related to this Invention is a unit brake equipped with a cylinder device with a spindle positioned in a region in communication with the atmosphere, a brake lever capable of swinging around a support axis through movement in the spindle axial direction, and a brake shoe receptacle linked to and driven by the brake lever, and the cylinder device has a first piston operating by opposing a first pressure chamber to a first spring positioned in a region in communication with the atmosphere and, with compressed fluid supplied to the first pressure chamber, has a regular brake part moving in the brake direction of the brake force generated by the first piston in resistance to the first spring added force, and a second piston operating by opposing a circular second pressure chamber installed opposing the first pressure chamber to a second spring installed concentrically on the outside of the first pressure chamber, and where a spindle has a specified gap for penetrating the central part, and has a spring brake part that moves from a state of supplying compressed fluid to the second pressure chamber to an exhausting state where the second piston moves in the brake direction by the second spring added force, a nut member rotatably screwed in versus the spindle, and with clutch part installed on the anti-brake direction in the opposite direction from the brake direction, a clutch engaged in the nut member clutch area on the side opposing the said nut member in the area around the spindle that was positioned in the anti-brake direction in a direction opposite to the brake direction versus the nut member, a clutch box forming a cylinder and housing the nut member and clutch on its inside, and a supporting bearing that can rotate the nut member versus the clutch box on the inside of the clutch box, and furthermore, the clutch is equipped with a clutch mechanism where displacement of the brake direction and anti-brake direction versus the clutch box is enabled, and the rotation direction displacement is regulated, and the clutch mechanism is positioned in a region where the first spring is positioned, on the inside of the circular ring of the second pressure chamber, and further in the brake direction than the second piston, with compressed fluid also exhausted from the second pressure chamber, so that the clutch is moved by the second spring added force, together with the second piston, in relation to the clutch box, to engage the clutch part of the nut member, and to enter a linked state where the spindle and second piston are linked and the nut member is non-rotatable, and compressed fluid is supplied to the second pressure chamber, resulting in the clutch becoming separated from the nut member, to become a non-linked state where the link between the spindle and second piston is released.
[0012] According to the above-mentioned configuration, the clutch opposing the nut member in the area around the spindle that was positioned in a region in communication with the atmosphere is positioned in the anti-brake direction versus the nut member, and when the clutch mechanism is moved in a linked state, the clutch moves together with the second piston to grip the clutch part of the nut member. In addition, the nut member screwed into the spindle and rotatably supported is supported to enable moving in the anti-brake direction. For this reason, if the compressed fluid in the first pressure chamber of the regular brake part is slowly outgassed, the first piston added force is weakened due to action of the first pressure chamber, and the first piston is pushed in the anti-brake direction by the spring-back reaction force from the brake shoe side, the nut member will be pushed in deeply gripping direction toward the clutch. With this action, even if the compressed fluid in the first pressure chamber is outgassed and the spring-back reaction force from the brake shoe side is activated, the disengagement of the gripping part with the nut member and clutch in the clutch mechanism is prevented. As a result, unintentional relaxation of the brake force in the spring brake part that is used as a parking brake, etc., is prevented.
[0013] In addition, with the above-mentioned configuration, the loosening of the mutual gripping part in the clutch mechanism, and the unintentional relaxation of braking force due to the spring brake part can be prevented. Furthermore, since a protruding part as seen in Patent Citation 2 is not generated in the cylinder back part, the installation space problem can also be solved.
[0014] In addition, with the above-mentioned configuration, since the first pressure chamber in the anti-brake direction of the clutch box holding the bearing is installed, exposure of the bearing to the compressed fluid can be prevented. In addition, in the same way, since the second pressure chamber on the outer side of the clutch box holding the bearing on the inner side is installed, exposure of the bearing to the compressed fluid can be prevented. Furthermore, since air surrounding the bearing flows smoothly, even if the atmosphere becomes humid, if the atmosphere afterward becomes drier, the atmosphere around the bearing also dries out. As a result, since grease applied to the bearing can be prevented from deterioration due to oil or water incorporated in the compressed fluid, it can maintain performance even through long-term use.
[0015] (2) In the above-mentioned unit brake, the spindle has a specified gap for penetrating the central part of the clutch, the clutch disengagement spring that applies force to the clutch in the anti-brake direction versus the clutch box is positioned concentrically on the outer side of the nut member, and the bearing is installed so that it faces the region where the clutch disengagement spring is positioned.
[0016] With the above-mentioned configuration, the air in the atmosphere passes through a specified gap formed between the spindle and clutch, and transits between the clutch and nut member to adequately supply the region where the clutch disengagement spring is positioned. It follows that, even if the atmosphere becomes humid, if the atmosphere afterward becomes drier, the air in the region where the clutch disengagement spring is positioned also dries out. As a result, grease applied to the bearing can more surely prevent deterioration due to a humid atmosphere.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 Cross-section illustration showing the general configuration of the unit brake applied to the first Embodiment of the Invention.
[0018] FIG. 2 Partial expanded illustration of the region shown at FIG. 1A .
[0019] FIG. 3 Illustration showing the state when the regular brake of the unit brake in FIG. 1 is activated.
[0020] FIG. 4 Illustration showing the state when the spring brake of the unit brake in FIG. 1 is activated.
[0021] FIG. 5 Cross-section illustration showing unit brake in other examples.
[0022] FIG. 6 Cross-section illustration at the D-D line arrow position in FIG. 5 .
EXPLANATION OF KEY CODE
[0000]
100 , 100 a Unit brake
10 Cylinder device
20 Brake lever
30 Brake shoe receptacle
50 , 50 a Spindle
60 Regular brake part
61 first piston
64 first pressure chamber
66 Return spring member (first spring)
70 Spring brake part
71 second piston
71 b Side wall
74 second spring chamber
75 Spring member (second spring)
81 Nut member
82 Clutch box
83 Bearing
84 Clutch
S 1 Gap
S 2 Gap
DESCRIPTION OF THE INVENTION
[0043] Here follows a description of the unit brake related to the Embodiment of this Invention, with reference to the illustrations.
[0044] <General Configuration of Unit Brake 100 >
[0045] The unit brake 100 related to the Embodiment of this Invention is configured as a railroad car brake device. This unit brake 100 is equipped mainly with a cylinder device 10 for generating force, a brake lever 20 enabling swivel motion versus the movement of the cylinder device 10 , a brake shoe receptacle 30 that can be moved forward and back by the swivel motion of the brake lever 20 , and on which is mounted a brake shoe not shown in the illustration, a casing 40 that is formed in a hollow shape, and with an interior that enables communication with the atmosphere. In this casing 40 , a connection hole 41 is formed, and a bolt not shown in the illustration inserted into this connection hole 41 is set so that the casing 40 can be fixed to a vehicle carriage.
[0046] <Brake Lever 20 >
[0047] The brake lever 20 is housed in the casing 40 . This brake lever 20 is supported by a rotatable spindle 21 mounted inside the casting 40 . Also, the brake lever 20 is distributed in a stance that extends in the up and down directions.
[0048] The spindle 21 is installed in the intermediate area of the brake lever 20 . Also, the brake lever 20 is formed as an arm part 22 on the side higher than the spindle 21 , and a bearing hole 24 is installed on the side lower than the spindle 21 .
[0049] A spherical bearing 26 is fitted into the bearing hole 24 , and a sheathed rod 28 is fixed into the inner ring of this spherical bearing 26 . The sheathed rod 28 is formed in a cylindrical shape, with a female screw cut on the inner surface. Also, a spindle 29 is screwed into the sheathed rod 28 female screw. With this action, the spindle 29 can have the protrusion volume adjusted in relation to the sheathed rod 28 .
[0050] <Casing 40 >
[0051] An upper side second opening 42 , upper side second opening 43 , and lower side opening 44 , are formed in the casing 40 . The upper side first opening 42 is formed in the upper part of the casing 40 vehicle wheel side sidewall 45 (side wall on the left side of FIG. 1 ), and a cylinder device 10 is attached to plug up this upper side first opening 42 .
[0052] The lower side opening 44 is formed in the lower part of the vehicle wheel side sidewall 45 . The spindle 29 passes through the lower side opening 44 to protrude toward the vehicle wheel side, and a brake shoe receptacle 30 is installed at the tip part.
[0053] A ventilation cylinder 40 a is installed in the lower part of the casing 40 , and there is communication between the outside atmosphere and the interior of the casing 40 .
[0054] <Cylinder Device 10 >
[0055] The cylinder device 10 is equipped with a spindle 50 with a multiple thread screw on the side surface, and this spindle 50 is moved along the axial direction to swivel the brake lever 20 .
[0056] This cylinder device 10 is mainly equipped with the above-mentioned spindle 50 , a regular brake part 60 used for decelerating or stopping a running vehicle, a spring brake part 70 used for vehicle parking, etc., and a clutch mechanism. The regular brake part 60 and spring brake part 70 are configured so as to be operated by the shared spindle 50 .
[0057] <Regular Brake Part 60 >
[0058] The regular brake part 60 operates through compressed and other fluid pressure force. This regular brake part 60 is equipped with a first piston 61 connected to the base end part of the spindle 50 , a return spring member 66 positioned in a region providing the casing 40 air (equal to atmospheric pressure) from grooves in the multiple thread screw of the spindle 50 installed so as to penetrate the second spindle 71 described below, or gaps in each member, or in other words, a region communicating with the atmosphere, and a cylindrical first cylinder body 62 with bottom that can swivel-handle the first piston 61 .
[0059] A first port 63 for supplying and exhausting compressed fluid is installed in the first cylinder body 62 , and inside the first cylinder body 62 , a first pressure chamber 64 is formed in communication with this first port 63 . In the first pressure chamber 64 , compressed air and other compressed fluids are supplied or exhausted in response to the specified brake operation, and the first piston 61 moves in resistance to the added force of the return spring member 66 . Also, the first pressure chamber 64 is formed from the first piston 61 and the first cylinder body 62 . This first pressure chamber 64 is partitioned in the anti-brake direction by a clutch box 82 that is described below.
[0060] <Spring Brake Part 70 >
[0061] The spring brake part 70 activates with a spring elastic force due to a spring member 75 , described below. This spring brake part 70 is penetrated by the spindle 50 , and equipped with a second piston 71 movable in the axial direction (arrow X direction) of the spindle 50 , and a second cylinder body 72 that can swivelably house the second piston 71 . The second cylinder body 72 has a trunk part 73 installed on the outward circumference side of the trunk part 65 of the first cylinder body 62 . In addition, the second piston 71 is configured to be contactable to the tip area of the trunk part 65 of the first cylinder body 62 . The second cylinder body 72 is fixed in the casing 40 . Between the second piston 71 and the casing 40 vehicle wheel side sidewall 45 is formed a second pressure chamber 74 that supplies compressed air and other compressed fluids by way of a second port (omitted from the illustration). This second pressure chamber 74 is formed from the second piston 71 , the casing 40 , and the second cylinder body 72 . In addition, the second pressure chamber 74 is formed from a cylindrical shape installed facing the first pressure chamber 64 . Also, the second pressure chamber 74 is partitioned in the outer side of the clutch box 82 , described below. In addition, the spindle 50 is installed maintaining and penetrating a specified gap in the central part of the second piston 71 .
[0062] Also, a spring member 75 is installed on the side opposite the second pressure chamber 74 versus the second piston 71 . This spring member 75 is positioned between the trunk part 65 of the first cylinder body 62 positioned on the inner side, and the trunk part 73 of the second cylinder body 72 positioned on the outer side, and also positioned concentrically on the outer side of the first pressure chamber 64 , and is compressed by reception of fluid pressure inside the second pressure chamber 74 . While a normal compressed fluid is introduced into the second pressure chamber 74 , compressing the spring member 75 , performance of a specified brake operation exhaust the compressed fluid inside the second pressure chamber 74 , and the spindle 50 is moved in the brake direction (arrow X1 direction) based on the spring force of the spring member 75 .
[0063] The second piston 71 of this Embodiment has a clutch housing part 71 a where the central part of the spindle 50 side forms a bump on the first piston 61 side, and the clutch mechanism described below is housed on the inner side of this clutch housing part 71 a . Also, in this Embodiment, in the tip area of the spindle 50 side of the second piston 71 , a sidewall 71 b is formed stretching along the axial direction (arrow X direction) of the spindle 50 . A thrust bearing 85 , described below, is held in this sidewall 71 b . Also, in this Embodiment, a gap S 1 where air can pass is formed between the sidewall 71 b and the spindle 50 .
[0064] Meanwhile, the return spring member 66 is positioned between the first piston 61 and the second piston 71 . This return spring member 66 pressures the first piston 61 in the compression direction (anti-brake direction (arrow X2 direction) of the first pressure chamber 64 , and when a compressed fluid is introduced to the first pressure chamber 64 , it is compressed by this fluid pressure. Since normally there is no compressed fluid introduced inside the first pressure chamber 64 , the spindle 50 moves in the anti-brake direction (arrow X2 direction) based on the spring force of the return spring member 66 . Also, compressed fluid is introduced to the first pressure chamber 64 by the specified break force, and the spindle 50 moves in the brake direction (arrow X1 direction). Moreover, when the compressed fluid inside the first pressure chamber 64 is exhausted by the specified brake release operation, the spindle 50 is returned to the initial state by the spring force of the return spring member 66 .
[0065] <Clutch Mechanism>
[0066] The clutch mechanism switches the nut member 81 rotation and fixed. Specifically, the clutch mechanism allows rotation of the nut member 81 versus the spindle 50 when the regular brake part 60 is driven, and fixes the nut member 81 versus the spindle 50 when the spring brake part 70 is driven. The clutch mechanism in the Embodiment, as is described below, is positioned in a region that does not interfere with the first pressure chamber 64 and second pressure chamber 74 .
[0067] The clutch mechanism, not shown in the illustration, mainly has the nut member 81 , the clutch box 82 housing the nut member 81 in its inner side, a bearing 83 rotatably supporting the nut member 81 versus the clutch box 82 , a clutch 84 positioned opposing the nut member 81 , a thrust bearing 85 rotatably supporting the clutch box 82 versus the second piston 71 , a clutch box stay spring 86 , and a clutch spring 87 . This clutch mechanism is normally locked to disable rotation by a lock lever 88 , described below.
[0068] The nut member 81 is rotatably screwed versus the spindle 50 . In addition, the nut member 81 is rotatably supported by way of the bearing 83 versus the clutch box 82 . With this action, the nut member 81 is rotated by relative motion of the spindle 50 and the clutch box 82 . In addition, the nut member 81 is rotatably supported together with the clutch box 82 toward the anti-brake direction (arrow X2 direction) which is the reverse direction. Also, in the part facing the clutch 84 of the nut member 81 , a mutually gripping (connecting) external gear 81 a is formed in the external gear 84 a of the said clutch 84 .
[0069] In addition, when the clutch external gears 81 a , 84 a are connected, motion toward the brake direction and anti-brake direction is allowed versus the clutch box 82 , but rotation direction displacement toward the spindle 50 axis area is restricted.
[0070] The clutch box 82 is formed as a cylindrical member positioned on the inner side of the nut member 81 and the clutch 84 . A key 82 a linking the said clutch box 82 and clutch 84 is fixed within this clutch box 82 . This key 82 a is positioned in a groove 84 b formed in the clutch 84 . With this action, the clutch 84 is in a state versus the clutch box 82 where rotation direction displacement centering on the spindle 50 axial direction is restricted, and it slides in parallel along the axial line direction (arrow X direction). In other words, the clutch box 82 slidably supports the clutch 84 along the second piston 71 movement direction.
[0071] In addition, in the clutch box 82 is installed a clutch disengagement spring 82 b that adds force in a direction moving away from the nut member 81 . This clutch disengagement spring 82 b is installed on the inner side of the clutch box 82 (spindle 50 side), and concentrically on the outer side of the nut member 81 and clutch 84 . In addition, the clutch box stay spring 86 is installed between the clutch box 82 and the second piston 71 .
[0072] The clutch 84 is formed as a cylindrical member, and is positioned in the anti-brake direction (arrow X2 direction) versus the nut member 81 . Also, in this Embodiment, a gap S 2 where fluid can pass is formed between the clutch 84 and the spindle 50 . Moreover, this clutch 84 is installed around the spindle 50 so as to face the nut member 81 . The clutch 84 is rotatably supported by the second piston 71 , by way of the thrust bearing 85 , at the tip area of the anti-brake direction (arrow X2 direction). With this action, when the second piston 71 moves along the brake direction (arrow X1 direction) versus the spindle 50 , based on the added force of the spring member 75 , the clutch 84 also moves together with the second piston 71 in the brake direction (arrow X1 direction) versus the spindle 50 , by way of the second piston 71 and the thrust bearing 85 .
[0073] The above-mentioned clutch mechanism is a region where the return spring member 66 is positioned, and is positioned on the inner side of the second pressure chamber 74 ring. In addition, the position of the said clutch mechanism is positioned more in the brake direction (arrow X1 direction) than is the second piston.
[0074] The clutch mechanism transitions from a state where compressed air is supplied to the second pressure chamber 74 , to a state where it is exhausted, and the clutch 84 is moved together with the second piston 71 in the brake direction (arrow X1 direction) versus the spindle 50 , by the added force of the spring member 75 , to set a linked state mutually gripped with the nut member 81 (mutually gripping the external gear 81 a of the nut member 81 and the external gear 84 a of the clutch 84 ), and linking the spindle 50 and the second piston 71 .
[0075] Meanwhile, in the state where compressed air is supplied to the second pressure chamber 74 , the clutch 84 becomes separated from the nut member 81 (the external gear 81 a and external gear 84 a are not mutually gripping), and the nut member 81 enters a freely rotating state. For this reason, when in the state where compressed air is supplied to the second pressure chamber 84 , the clutch mechanism is set to a non-linked state where the link of the spindle 50 and the second piston 71 is released.
[0076] In the cylinder device 10 , the lock lever 88 is installed to enable switching between the clutch mechanism locked state and unlocked state. A latch gear 82 c is installed on the outer circumferential surface of the clutch box 82 brake direction (arrow X1 direction), and a lock gear 88 a that is configured to enable connection with the said latch gear 82 c is installed in the inner tip area of the lock lever 88 . The lock lever 88 uses and added force member 89 to add force in the direction connecting the lock gear 88 a to the latch gear 82 c , and lifting up the lock lever 88 releases the connection between the latch gear 82 c and lock gear 88 a , which action puts the clutch box 82 in a rotatable state. This configuration enabling release of the clutch box 82 lock state is to enable manual release of the spring brake part 70 when a situation arises where for some reason the compressed fluid in the second pressure chamber 74 is exhausted, putting the spring member 75 of the spring brake part 70 in in extended state (the spring brake part 70 is in an operations state).
[0077] <Spindle 50 >
[0078] The spindle 50 has a screwing part formed by multiple screws on the outward circumference side, and an extension part extending in the axial direction (arrow X1 direction) from the tip of this screwing part. Also, the nut member 81 of the clutch mechanism is screwed into this screwing part. With this action, the nut member 81 is enabled to move in the arrow X direction versus the spindle 50 .
[0079] The spindle 50 is inserted into the upper side first opening 42 . In the extension part, a partially cut-off area is formed on the outer circumferential surface, with a specified length in the axial direction. In the said area, a pair of wall parts are formed facing the axial direction of the spindle 50 .
[0080] One of the wall parts (first wall part) 54 has a contact surface contacting the brake lever 20 when the spindle 50 is advancing, and the other wall part (second wall part) 55 has a contact surface contacting the brake lever 20 when the spindle 50 is retreating. Between the two wall parts a gap is formed where a force point part 23 can be inserted.
[0081] In the connection part, a pair of flat surfaces are formed as side surfaces. These flat surfaces are positioned symmetrically versus the spindle 50 axis, and form flat, almost vertical surfaces to the axis. The above-mentioned perforation hole is opened in this connection part. In other words, since the interval between both surfaces of the connection part (width of connection part) is smaller than the diameter of the perforation hole, the perforation hole is opened on the side surface of the connection part so that each flat surface is divided into top and bottom.
[0082] An expanded diameter area is installed in this perforation hole, and a wear ring 57 is fitted into this expanded diameter area.
[0083] The brake lever 20 has the force point part 23 installed in the upper tip part (front tip part), or in other words, the upper tip part (front tip part) of the arm part 22 . This force point part 23 is an area that accompanies the spindle 50 drive, and receives force from the said spindle 50 , and is inserted into the space between the spindle 50 wall parts.
[0084] A guide rod is inserted into the perforation hole of the spindle 50 . The base end part of the guide rod is fixed to the vehicle wheel in the casing 50 and to the sidewall 46 on the opposite side, and it is positioned in the same axial shape as the spindle 50 .
[0085] A pair of flat surfaces are formed in the guide rod. When the guide rod is inserted into the spindle 50 perforation hole, these flat surfaces form a surface shape together with the flat surface of the spindle connection part.
[0086] Next is a description of the unit brake 100 operation.
[0087] FIG. 1 is a cross-section illustration of the cylinder device 10 when neither the regular brake part 60 nor the spring brake part 70 are in operation. For example, when the brake operation is not being performed while a rail vehicle is in operation, it becomes the state shown in FIG. 1 . In this state, a regular brake control device (not shown in the figure) controls so that the supply of compressed air from an air supply source (not shown in the figure) by way of the first port 63 to the first pressure chamber 64 is not performed. Also, compressed air within the first pressure chamber 64 is naturally exhausted by way of the first port 63 . For this purpose, the first piston 61 uses the return spring member 66 to add force in the anti-brake direction (arrow X2 direction), and the first piston 61 enters a state of contact with bottom part of the first cylinder body 62 .
[0088] Meanwhile, in the state shown in FIG. 1 , compressed air is supplied to the second pressure chamber 74 by way of the second port (not shown in the figure) from an air supply source (not shown in the figure), based on the control of a spring brake control valve (not shown in the figure). For this purpose, added force based on the operation of compressed air supplied to the second pressure chamber 74 puts the second piston 71 in a state of moving in the anti-brake direction (arrow X2 direction) in opposition to the added force of the spring member 75 . In this state, the external gear 81 a of the nut member 81 , and the external gear 84 a of the clutch 84 are not mutually gripping, and a state forming a gap is entered.
[0089] FIG. 3 is a cross-section illustration of the cylinder device 10 showing a state where the regular brake part 60 has been activated. Based on control of the regular brake control device, compressed air is supplied to the first pressure chamber 64 by way of the first port 63 , to activate the regular brake part 60 . At this time, the added force by use of compressed air supplied to the first pressure chamber 64 moves the first piston 61 in the brake direction (arrow X1 direction) in opposition to the added force of the return spring member 66 . With this action, the spindle 50 moves in the brake direction together with the first piston 61 , pushing the brake shoe against the tread surface of the vehicle wheel, to generate braking force. However, when the spindle 50 moves in the brake direction together with the first piston 61 , since the nut member 81 is freely supported by the bearing 83 versus the clutch box 82 , together with the spindle 50 move in the brake direction, the nut member 81 rotates while being supported by the clutch box 82 . With this action, only the spindle 50 will move in the brake direction.
[0090] FIG. 4 is a cross-section illustration of the cylinder device 10 showing a state where the spring brake part 70 has been activated. When activating the spring brake 70 , for example, in a state where the regular brake part 60 is activated (see FIG. 3 ) when the rail vehicle has been completely stopped, the spring brake part 70 becomes activated for use as a parking brake, etc. Based on control of the spring brake control device (not shown in the figure), compressed air is exhausted from the second pressure chamber 74 for activation.
[0091] When compressed air that has been supplied to the second pressure chamber 74 is exhausted, the added force of the spring member 75 starts the second piston 71 moving in the brake direction (arrow X1 direction). At this time, the clutch 84 that freely rotates to the thrust bearing 85 supported by the second piston 71 begins to move together with the second piston 71 in the brake direction versus the spindle 50 . Note that, at this time, the clutch 84 moves in the brake direction by a sliding operation with the groove 84 b and key 82 a versus the clutch box 82 . Also, when the second piston 71 begins in this way to move together with the clutch 84 versus the spindle 50 , the clutch 84 comes into contact with the nut member 81 . In other words, the external gear 81 a of the nut member 81 , and the external gear 84 a of the clutch 84 , are mutually gripping, and the nut member 81 rotation stops.
[0092] As described above, the nut member 81 and clutch 84 are mutually gripping, so that the clutch mechanism moves from a non-linked state to a linked state. Also, since the nut member 81 rotation can be stopped in this linked state, force is added to the spindle 50 by way of the clutch 84 and nut member 81 when the second piston 71 is moving in the brake direction based on the added force of the spring member 75 , and the spindle 50 is maintained in the state where the first piston 61 and spindle 50 are moving in the brake direction. In other words, it is maintained in the state where the spring brake part 70 is activated and the spring brake force is used.
[0093] <Characteristics of Unit Brake 100 in this Embodiment>
[0094] As described above, in the Embodiment, the clutch 84 facing the nut member 81 around the spindle 50 is positioned in an anti-brake direction versus the nut member 81 , and when the clutch mechanism is moving in a linked state, the clutch 84 moves together with the second piston 71 to mutually grip with the nut member 81 . Also, the nut member 81 that is screwed in to the spindle 50 and rotatably supported is supported to enable movement in the anti-brake direction. For this reason, the first pressure chamber 64 compressed fluid in the regular brake part 60 is slowly outgassed, causing the added force of the first piston 61 based on activation of the first pressure chamber 64 to weaken, and when the first piston 61 is pushed in the anti-brake direction by spring-back reaction force from the brake shoe side, the nut member 81 is pushed deeply in the mutually gripping direction toward the clutch 84 . With this action, even if the first pressure chamber 64 compressed fluid is outgassed and the spring-back reaction force from the brake shoe side is activated, disengagement of the nut member 81 and clutch 84 mutually gripping pat in the clutch mechanism is prevented. For this reason, unintentional relaxation of the brake force in the spring brake part 70 used as a parking brake, etc., is prevented.
[0095] Furthermore, in the Embodiment, since the clutch mechanism is positioned in a region that does not interfere with the first pressure chamber 64 and second pressure chamber 74 , it can prevent the size of the cylinder device 10 from growing larger. Particularly since it does not generate a protruding part like that in the unit brake listed in Patent Citation 2, it can prevent the outward form of the cylinder device from growing larger. As a result, an existing unit brake can be replaced with the unit brake 100 where the spring brake is not unintentionally relaxed, without needing to make any changes to the configuration on the rail vehicle side.
[0096] And again furthermore, in the Embodiment, since the first pressure chamber is installed in the anti-brake direction of the clutch 84 box holding the bearing 83 , the bearing 83 is not exposed to compressed fluid, and in the same way, since the second pressure chamber 74 is installed on the outer side of the clutch 84 box holding the bearing 83 on its inner side, the bearing 83 is not exposed to the compressed fluid. In other words, since the bearing 83 surroundings are filled with air from outside, and since the grease coating the bearing will not deteriorate due to oil or water incorporated in the compressed fluid, performance can be maintained even over long-term use.
[0097] In addition, in the Embodiment, since a gap traversable by fluid is formed between the sidewall and the spindle 50 , and between the clutch 84 and spindle 50 , air from the outside is fully supplied by way of this gap to inside the space contained in the return spring member 66 . It follows that, even when the atmosphere is temporarily humid, if the atmosphere afterward becomes drier, the atmosphere around the bearing also dries out. As a result, prevention of deterioration of the grease coating the bearing 83 due to a humid atmosphere can be more certainly suppressed.
Other Example
[0098] Here follows descriptions of another example. For this other example, the description will be mainly of points that differ from the above-mentioned Embodiment.
[0099] As shown in FIG. 5 , the unit brake 100 a is equipped with a spindle 50 a in place of the spindle 50 . The spindle 50 a is equipped with a holding case 57 a . FIG. 6( a ), ( b ) is an illustration showing a cross-section of the holding case 57 a , and as shown in FIG. 6( a ), the spindle 50 a uses a rotation added force spring 57 d to add force in a reverse rotation direction (arrow E direction in the figure) to the rotation direction where the nut member 81 is deeply screwed into the spindle 50 a by way of a pin member 50 c.
[0100] For this reason, in a state where the tip parts of the external bearing 81 a and external bearing 84 a are in contact with each other, as shown in FIG. 6( a ), the spindle 50 a maintains its position with the pin member 50 c in a state of engagement with the stepped part of the inner wall of the holding case 57 a.
[0101] Here, if in a state where the spring brake method is fully activated, utilization in the spindle 50 a of the rotation force in the rotation direction shown at arrow D in FIG. 6( a ) puts the spindle 50 a in a state enabling rotation in that rotation direction. Also, the spindle 50 a comes to rotate in the rotation direction (rotation direction at arrow D in FIG. 6( a )) where the nut member 81 is deeply screwed into the spindle 50 a in opposition to the spring force of a rotation added force spring 57 d activated in the pin member 50 c . With this action, the nut member 81 moves slightly in the same direction as the brake direction, and is slightly rotated, to enable deep screwing into the spindle 50 a . Also, the contact position of the external bearing 81 a and external bearing 84 a is moved slightly from the position where the tip parts are in contact with each other, so that the external bearing 81 a and external bearing 84 a are adjusted to a deeper mutually gripping position.
[0102] In addition, the spindle 50 a is rotatable in a direction shown by the arrow in FIG. 3 until both tips of the pin member 50 c contact a protrusion wall part 57 b in the inner wall of the holding case 57 a . In other words, the pin member 50 c becomes capable of swiveling in the angle range shown at both tips arrow J in FIG. 6( b ), and the rotatable angle of the spindle 50 a is regulated.
[0103] Also, if the external bearing 81 a and external bearing 84 a are deeply mutually gripping, and the clutch 84 is in a mutually gripping state, a latch bearing 82 c of the nut member 81 , and a lock bearing 88 a of the lock lever 88 are in a state of engagement, so that linked rotation to rotation accompanying the movement of the nut member 81 in the brake direction is stopped. For this reason, rotation of the nut member 81 can be eventually stopped.
[0104] Note that if the clutch 84 is in a mutually gripping state, the nut member 81 moves together with the second piston 71 slightly in the brake direction in opposition to the added force of the rotation added force spring 57 d , and the engagement of the latch bearing 82 c of the nut member 81 , and the lock bearing 88 a of the lock lever 88 , deepens in the axial direction so that the second piston 71 , the nut member 81 , and the clutch 84 , become stopped.
[0105] As described above, the external bearing 81 a and external bearing 84 a are mutually gripping, and the nut member 81 and clutch 84 move from a non-linked state to a linked state. Also, in the linked state, since the nut member 81 rotation is stopped, the second piston 71 uses the added force of the spring member 75 to add force to the spindle 50 a by way of the clutch 84 when in a state moving in the brake direction, and a state where the spindle 50 a and the first piston 61 remain moved in the brake direction is maintained as is. In other words, the spring brake force is maintained in an activated state.
[0106] Note that the reaction from the brake shoe receptacle 30 pushed against the tread surface of the vehicle wheel is activated in the anti-brake direction versus the first piston 61 and the spindle 50 a , so that even when the nut member 81 and the clutch 84 are about to be disengaged, there is no disengagement because the mutual gripping is so deep, and the first piston 61 and spindle 50 a are maintained in the brake state position.
[0107] For example, in cases where wanting to use a tractor vehicle to slightly move the parking position of a rail vehicle without going so far as to activate the air compression function, cases where power is not supplied to the rail vehicle so that a tractor vehicle is used to move the rail vehicle, or other such where wanting to release the spring brake force, the lock lever 88 can be operated to manually release the spring brake force. In this case, if manual operation is used to pull up the lock lever 88 from the state where the sub brake is activated, toward the outer side of the first cylinder body 62 , the lock bearing 88 a of the lock lever 88 is disengaged from the latch bearing 82 c of the nut member 81 . Also, it becomes rotatable with the external bearing 81 a and external bearing 84 a remaining in a state of mutual gripping, and the clutch 84 becoming empty spinning.
[0108] With this action, both the first piston 61 and the second piston 71 can use the added force of the return spring member 66 and the spring member 75 to mutually move to the stroke end, and the spindle 50 a and the first piston 61 come to move in the anti-brake direction. In this way, the lock lever 88 can be operated to manually release the spring brake force and move the rail vehicle, etc.
[0109] In the other example above, the effectiveness of the Embodiment was successfully obtained, and the following effectiveness was also successful. In the other example, grease was coated even within the holding case 57 a , but since use occurred in the atmosphere, there was no exposure within compressed air. Therefore, deterioration of the grease (lubricating material, etc.) due to oil or water incorporated in the compressed fluid can be suppressed. As a result, performance can be maintained even over long-term use.
[0110] While the above was a description based on the illustrations regarding the Embodiment of this Invention, it is important to remember that the specific configuration is not limited to these Embodiments. The scope of this Invention is shown not only through the description of the above-mentioned Embodiments, but also through the scope of the Patent Claims, and all changes are incorporated within the scope of the Patent Claims and the scope of equivalent meanings.
[0111] (Correspondence Relationship of Each Configuration Elements the Claims, to Each Part in the Above-Mentioned Embodiments)
[0112] In the above-mentioned Embodiments, the unit brakes 100 , 100 a correspond to “unit brake”, the spindles 50 , 50 a correspond to “spindle”, the cylinder device 10 corresponds to “cylinder device”, the brake lever 20 corresponds to “brake lever”, the brake shoe receptacle 30 corresponds to “brake shoe receptacle”, the first pressure chamber 64 corresponds to “first pressure chamber”, the return spring member 66 corresponds to “first spring”, the first piston 6 corresponds to “first piston”, the regular brake part 60 corresponds to “regular brake part”, the second pressure chamber 74 corresponds to “second pressure chamber”, the spring member 75 corresponds to “second spring”, the second piston 71 corresponds to “second piston”, the spring brake part 70 corresponds to “spring brake part”, the nut member 81 corresponds to “nut member”, the clutch 84 corresponds to “clutch”, the clutch box 82 corresponds to “clutch box”, the bearing 83 corresponds to “bearing”, and the clutch mechanism corresponds to “clutch mechanism”.
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Disclosed is unit brake, which is equipped with a cylinder apparatus in which a clutch mechanism that switches between transmitting or cutting off a biasing force of a spring brake part is disposed, is capable of preventing a braking force due to the spring brake part from unintentionally decreasing due to a meshing section of the clutch mechanism disengaging, and is of a size that can replace an existing unit brake, and maintains the performance of bearings in the clutch mechanism even with long-term use. The clutch mechanism of the unit brake includes: a nut member that rotatably screws on a spindle that is positioned in an area that communicates with the atmosphere, and is movably supported in a direction opposite to braking; a clutch that is disposed in a direction opposite to braking with respect to the nut member, and faces the nut member in the vicinity of the spindle; a clutch box that is formed in a cylinder shape, and houses the nut member and clutch on the inside; and bearings that rotatably support the nut member on the inside of the clutch box.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of copending international patent application PCT/EP00/12571 filed on Dec. 12, 2000 and designating the U.S., which claims priority from German patent applications DE 100 00 779.1, filed on Jan. 11, 2000.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a method for the transformation of image signals that have been obtained by color filtering and have been logarithmically compressed, wherein the color saturation of the recorded images is modified. The invention furthermore relates to a saturation stage for carrying out the method and also to a digital camera having such a saturation stage.
[0003] In photographic and film camera technology, electronic image recorders, which convert an optical intensity distribution into electronic image signals, are increasingly being used as a replacement for conventional film material. Such image recorders have a regular arrangement of pixels which are each assigned one or more light-sensitive circuits comprising semi-conductor components, these circuits hereinafter being referred to as image cells. Each of these image cells generates an image signal whose voltage value is a function of the intensity of the light impinging on the image cell.
[0004] In image recorders for color reproduction, each pixel generally comprises a triad of image cells which are each covered by a color filter for one of the three spectral colors red, green and blue. Each signal of such an image cell reproduces a brightness value relative to the relevant spectral color, so that the totality of the three individual signals contains the color information for the relevant pixel.
[0005] If an image represented by such image signals is viewed directly on a monitor, then the result generally deviates more or less significantly from the actual visual impression gained by a person by directly viewing the recorded motif. Therefore, the image signals are generally digitized and, in digital signal processors, subjected to different transformations in order to adapt the recorded images to the actual visual impression.
[0006] Such transformations can be used for example to remove color casts (color transformations) or to brighten or darken recorded images overall (brightness transformations). Furthermore, it is possible to modify the color saturation of such electronic images. The saturation of a color is understood here as the difference between the color value and a grey-scale value of the same brightness. Weakly saturated colors are therefore pale or even greyish, while strongly saturated colors have a powerful and brilliant effect.
[0007] The description of such transformations is usually based on the so-called RGB color model, since this largely corresponds to the method of operation of image recorders and color monitors. This is because both in the RGB color model and in image recorders and color monitors colors are reproduced by components of the three spectral colors red, green and blue, which can each assume values between 0 and 1 in the color model. In this way, the totality of the representable colors can be represented in a unit cube spanned by a coordinate system on whose axes the three color components are plotted. If the components of the three primary colors have the same magnitude, which corresponds to a point on a spatial diagonal of the unit cube, then a pure grey-scale value is obtained. In the case of a weakly saturated color, the point representing this color lies in the vicinity of this spatial diagonal, i.e. the components of the spectral colors deviate only slightly from one another.
[0008] A transformation for the saturation of RGB colors is known from a paper by Paul Haeberli from 1993, which was published on the Internet under the address http://wwp.sqi.com/graphica/matrix/index.html. If R designates an image signal for the spectral color red at a specific pixel, then the transformed image signal R′ is produced, after the transformation described there, from the equation
R′=α ·( R−L )+ L,
[0009] where L designates a brightness value for the relevant pixel and α designates a saturation factor. Corresponding equations apply with regard to the transformed image signals G′ and B′ for the spectral color green and blue, respectively, the saturation factor α and the brightness value L being identical for all the spectral colors of a pixel. In this case, the brightness value L is determined according to the equation
L=R·W
R
+G·W
G
+B·W
B
[0010] where
[0011] W R =0.3086,
[0012] W G =0.6094 and
[0013] W B =0.0820.
[0014] If the saturation factor α is chosen to be less than 1, then this leads to a reduction of the color saturation. Saturation factors α which are greater than 1 produce more strongly saturated colors.
[0015] The paper furthermore points out that this transformation leads to correct results only when the image signals R, G and B are linear. Linear image signals are distinguished by the fact that there is a linear relationship between the voltage value of such an image signal and the optical intensity which impinges on the relevant pixel. This is the case for example with the image recorders using CCD technology (CCD=charge coupled device) that are often used in today video cameras. By contrast, if linear image signals are not involved, then according to Haeberli these signals must first be converted into linear signals before it is possible to carry out the above-described transformation for altering the color saturation.
[0016] EP 0 632 930 B1 discloses an image recorder which compresses a high input signal dynamic range logarithmically to a considerably smaller output signal dynamic range. Each pixel of this known image recorder thus generates an output voltage which corresponds to the logarithm of the optical intensity impinging thereon. As a result, the extremely high irradiance dynamic range of natural scenes, which is of the order of magnitude of 120 dB, can be acquired by signal technological means. Such an image recorder can thus be used to electronically acquire images whose brightness dynamic range comes extremely close to the actual visual perception of humans. This is primarily due to the fact that the human eye also has an approximately logarithmic visual sensitivity.
[0017] While these logarithmically compressed image signals reproduce a brightness dynamic range of about 120 dB, the absolute differences between the image signals of the individual spectral colors are comparatively small, however. It has the result that the images recorded using the known image recorder often have an inadequate color saturation. It therefore appears to be possible to follow the suggestion made in the paper by P. Haeberli cited above and firstly to linearize again the logarithmically compressed image signals after digitization, then to transform them in the manner described there and subsequently to logarithmize them again. However, such linearization (i.e. delogarithmization) and subsequent logarithmization of the image signals is highly complex computationally and can therefore be achieved only with expensive digital signal processors.
SUMMARY OF THE INVENTION
[0018] It is therefore an object of the invention to specify a method of the type mentioned in the introduction which allows modification of the color saturation in a more simple manner.
[0019] It is particularly an object of the invention to specify a simple and straight-forward method for modifying or enhancing the color saturation of image signals provided in a logarithmically compressed format.
[0020] It is furthermore an object of the invention to specify a saturation stage for modifying the color saturation of images in a simple and inexpensive manner, which can be used to transform image signals that have been obtained by color filtering and have been logarithmically compressed.
[0021] With a method as mentioned in the introduction, this object is achieved according to one aspect of the invention by virtue of the fact that the transformed image signals are determined as a function of the logarithmically compressed image signals and logarithmically compressed brightness signals at least for one spectral color.
[0022] With regard to a saturation stage, the object is achieved by means of a computer, which the transformed image signals can be determined with as a function of the logarithmically compressed image signals and logarithmically compressed brightness signals for at least one spectral color.
[0023] Contrary to the prejudice above, it has been found that a transformation carried out directly on the basis of logarithmically compressed image signals leads to outstanding results in the improvement of the color saturation. The only precondition for this is that logarithmically compressed brightness signals also enter into the transformation. The transformations which are known for linear image signals can thus essentially be adopted, to be precise surprisingly without corresponding logarithmization of the transformation equations. Thus, e.g. a computation operation for linear signals in which a linear signal S is multiplied by a factor k continues to be a multiplication by k (or a value k′) in the case of a logarithmically compressed signal S′. In other words, the multiplication by k is not logarithmized, i.e. converted into an addition of log k.
[0024] For a specific pixel, the logarithmically compressed brightness signal can be provided for example by an additional image cell which receives color-unfiltered light and therefore supplies a pure brightness signal for this pixel. It is equally possible, of course, to determine the logarithmically compressed brightness signal for the relevant pixel using the logarithmically compressed image signals—if appropriate weighted in a suitable manner—for the three spectral colors. Moreover, it is possible to determine the brightness signal for a specific pixel also using image signals of one or more adjacent pixels.
[0025] It is particularly advantageous if the logarithmically compressed brightness signal for an individual pixel is equal to the arithmetic mean of the image signals of the relevant pixel which are assigned to the different spectral colors.
[0026] This determination of a brightness signal, which can be carried out very simply in terms of computation, leads to surprisingly good results in the modification of the color saturation if, according to the invention, there enter into the transformation directly logarithmically compressed image signals and logarithmically compressed brightness signals. The mean value can also be formed in an analogue manner, i.e. prior to digitization of the image signals, which allows the use of purely analogue circuit components.
[0027] In a preferred refinement of the invention, the transformed image signals L′ c are determined from the image signals L c for the at least one spectral color c according to the equation
L′ c =α c ·( L c −L )+ L
[0028] where α c is a saturation factor for the spectral color c and L is a logarithmically compressed brightness signal.
[0029] In this case, the difference between the image signal L c of a spectral color and the brightness value L at the relevant pixel represents the actual color component which is amplified by the saturation factor α c , provided that α c is chosen to be greater than 1. In contrast to known transformations, in which the saturation factor is identical for all the spectral colors, in this refinement of the invention it is also possible to choose different saturation factors α c for the individual spectral colors c. In this way, the color saturation can be increased in a targeted manner such that it is possible to obtain an extremely realistic image impression corresponding to normal visual customs.
[0030] Provided that the gain factors α c for the spectral colors c are constant, the above transformation is a linear transformation, which can be carried out in a particularly simple manner in terms of computation.
[0031] However, an increase in the color saturation which is even more true to reality can be obtained in many cases when the saturation factors α c are dependent on a contrast factor γ by which the logarithmically compressed image signals are multiplied before the transformation in the context of a γ correction.
[0032] The γ correction which is known per se and corresponds to an exponential operation with a contrast factor γ in the case of linear image signals is manifested as multiplication by the contrast factor γ in the case of logarithmic image signals. In the case of logarithmic image signals, too, the γ correction leads to a change in the contrast, i.e. in the absolute brightness difference between two adjacent pixels. This also affects the color saturation, so that in many cases an adaptation of the saturation factors to the value of the gain leads to better results.
[0033] In this case, it is particularly preferred if the saturation factors α c decrease as the contrast factor γ increases.
[0034] This is because a higher gain and thus a higher contrast lead to a reduced brightness dynamic range and therefore also require a lower color saturation gain.
[0035] In an advantageous refinement of the invention, it is preferred for the relationship between the saturation factors α c and the contrast factor γ to be described by a piecewise linear and monotonically falling function.
[0036] In this way, a very good adaptation of the color saturation to the gain can be performed in a computationally simple manner.
[0037] As an alternative or else in addition to a dependence on a gain factor, the saturation factors α c may be dependent on the logarithmically compressed brightness signals.
[0038] This takes account of the fact that the visual perception of humans can scarcely still make out color differences in the dark, so that it is possible to dispense with increasing the color saturation in this case. In the case of high brightness, on the other hand, colors are increasingly perceived as paler, which is why it is all the more important to increase the color saturation in that case. Therefore, the saturation factor α c for a specific pixel is preferably a monotonically increasing function of the logarithmically compressed brightness signal determined for this pixel.
[0039] In this case, it is particularly preferred if the saturation factors α c are proportional to the logarithmically compressed brightness signals.
[0040] As a result, the gain of the color saturation can be adapted very well to the brightness in a computationally simple manner.
[0041] It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the combination respectively specified but also in other combinations or by themselves, without departing from the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Further features and advantages of the invention emerge from the description of the following exemplary embodiments with reference to the drawing:
[0043] [0043]FIG. 1 shows a strongly diagrammatic illustration of a camera with an image recorder incorporated therein;
[0044] [0044]FIG. 2 shows a basic circuit diagram of an electronic unit for the further processing of image signals which have been generated by the image recorder illustrated in FIG. 1;
[0045] [0045]FIG. 3 shows a color cube for elucidating the RGB color model;
[0046] [0046]FIG. 4 shows a diagrammatic illustration of the range of values of untransformed image signals in the color cube;
[0047] [0047]FIG. 5 shows a diagrammatic illustration of the range of values of transformed image signals in the color cube, the saturation factors not depending on the brightness;
[0048] [0048]FIG. 6 shows a diagrammatic illustration of the range of values of transformed image signals in the color cube, the saturation factors depending on the brightness;
[0049] [0049]FIG. 7 shows a graph in which a saturation factor is plotted against a gain factor;
[0050] [0050]FIG. 8 shows a strongly diagrammatic illustration of a saturation device for carrying out the transformation according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0051] [0051]FIG. 1 shows a strongly simplified diagrammatic illustration of a digital camera 10 , which may be a photographic or film camera. The digital camera 10 has an electronic image recorder 12 , on whose light-sensitive surface a motif 14 is imaged with the aid of a lens system 16 , which is only indicated here. In an electronic unit 18 , the images recorded by the image recorder 12 are digitally processed further, so that they can finally be read out via a camera output 20 . The electronic unit 18 can be assigned an image memory—not illustrated in FIG. 1—in which the conditioned images can be stored. Moreover, it is possible to arrange only part of the electronic unit 18 within the digital camera 10 . The remaining parts are then realized outside the digital camera 10 , e.g. as software which can be executed on a personal computer.
[0052] [0052]FIG. 2 illustrates the image recorder 12 and also the electronic unit 18 with further details. The image recorder 12 has a regular arrangement of pixels 22 which, in a manner known per se, in each case have three light-sensitive image cells which are covered by different color filters. Each image cell of a pixel generates an output voltage which is a function of the intensity of the light of that spectral color which can pass through the filter assigned to this image cell. Consequently, three mutually independent image signals are generated in each pixel 22 , which image signals are respectively assigned to one of the three spectral colors red, green and blue. In this case, the image cells used in the image recorder 12 are realized as circuits of semiconductor components in which the functional relationship between the output voltage and the intensity of the impinging light is logarithmic. The image cells therefore generate logarithmically compressed image signals. Details on the construction of such image cells can be gathered from above mentioned EP-B-0 632 930, which is incorporated by reference herewith.
[0053] The image signals generated at the pixels 22 are read out row by row and column by column and combined in a multiplexer 24 to form an overall signal. The overall signal thus contains, in temporal sequence, the image signals assigned to the individual pixels 22 . Therefore, hereinafter explanations concerning image signals also always relate to the corresponding overall signal, and vice versa, unless the context reveals something different.
[0054] The overall signal is subsequently conditioned in an offset circuit 26 in such a way that fluctuations in the properties of the individual image cells, in particular the threshold voltages of the phototransistors contained therein, are compensated for. In this operation, which is also referred to as white balancing and only needs to be carried out a single time, the overall signal is firstly digitized in a first analogue/digital converter 28 , a uniform color area, e.g. a white area, being chosen as the motif to be recorded. This image, an inverted image or a differential image is stored in a memory 30 , so that it is always available during the subsequent recordings. The image stored in the memory 30 is then converted back into an analogue signal in a digital/analogue converter 32 and superposed on the analogue overall signal originating from the multiplexer 24 .
[0055] The brightness of the overall signal balanced in the offset circuit 26 is then regulated. This is done by addition of the value log g in an adder 34 . The addition of the value log g corresponds to the amplification of the overall signal by the factor g, which effects the adaptation of the brightness in linear image recorders, e.g. CCD sensors.
[0056] The amplified overall signal is subsequently subjected to a γ correction, by means of which, inter alia, the contrast of the recorded image is modified or distortions of the image signals are equalized. The γ correction which is realized by an exponential operation in a linear signal space is manifested as simple multiplication by the contrast factor γ in a logarithmic image signal space. The multiplier 36 provided for this purpose can therefore be embodied as a simple bit shifter if the values that can be assumed by the contrast factor γ are limited to powers of two.
[0057] The amplified and corrected overall signal is subsequently fed to a saturation stage 38 , in which the color saturation of the recorded image can be modified, in particular increased, in a targeted manner. For this purpose, saturation factors α c can be fed to the saturation stage 38 by a control unit or directly by a user, which saturation factors define the way in which the color saturation is modified in the saturation stage 38 .
[0058] The transformation of the overall signal which is performed in the saturation stage 38 is explained in more detail below with reference to FIGS. 3 to 7 .
[0059] [0059]FIG. 3, which serves merely for elucidating the RGB color model, shows a color cube 40 , which is used for representing colors in this model. The color cube 40 is spanned by a tripod 42 illustrated with a reduced size below the color cube 40 . The tripod 42 defines a coordinate system on whose axes are plotted the color components for the spectral colors red, green and blue. Upper-case letters R, G and B, respectively, enclosed in a box serve for designating the spectral colors in the drawing. Each color can be represented by a mixing of these three spectral colors red, green and blue, the hue being defined by the ratio of the components of these three spectral colors and the brightness being defined by the absolute values. The components can each assume values between 0 and 1, so that each color is reproduced by a point in the color cube 40 .
[0060] The corner of the color cube 40 which is designated by 44 corresponds e.g. to a pure red of maximum brightness, since the color components for the spectral colors green and blue are zero in each case. The point reproduced by the corner 46 of the color cube 40 represents the color yellow of maximum brightness, since, at this point, the color component of the colors red and green is 1 in each case, which leads to the mixed color yellow. The corner 48 corresponds to the color green, the corner 50 to the color magenta, the corner 52 to the color cyan and the corner 54 to the color blue.
[0061] In the corner 56 of the color cube 40 , which forms the origin of the tripod 42 , the color components are 0 in each case. This corresponds to the color black, which is indicated by the black quadrangle 58 in FIG. 3. The spatial-diagonally opposite corner 60 is characterized in that there the components of the three spectral colors red, green and blue are 1 in each case. This maximum color value leads to the mixed color white which is indicated by the letter W enclosed in a box. The points lying on the spatial diagonal between corners 56 and 60 are distinguished by the fact that the color components are in each case identical there as well. Consequently, the spatial diagonal 62 represents all grey-scale values whose brightness increases continuously from the corner 56 (black) to the opposite corner 60 (white). In FIG. 3, said spatial diagonal is designated by 62 and is illustrated in a widened fashion in order to be able to represent the grey-scale values.
[0062] [0062]FIG. 4 shows the color cube 40 from FIG. 3, the illustration depicting, instead of the spatial diagonal 62 , a cylinder 64 arranged concentrically with respect thereto. The cylinder 64 indicates the range of values which can be assumed by the image signals before they are subjected to the transformation according to the invention in order to increase the color saturation in the saturation stage 38 . The cylinder 64 arranged concentrically with respect to the spatial diagonal 62 makes it clear that the color values reproduced by the image signals are relatively close together, i.e. are situated in proximity to the spatial diagonal 62 . This means that the recorded images are relatively greyish, i.e. have a low color saturation.
[0063] [0063]FIG. 5 likewise shows a color cube 40 , in which a different cylinder 66 is depicted concentrically with respect to the spatial diagonal between the corners 56 and 60 . The cylinder 66 reproduces the range of values of the transformed image signals. As is directly discernible from this diagrammatic illustration, the transformed image signals can assume a significantly larger range of values within the color cube 40 . The color values have on average a greater distance from the spatial diagonal—reproducing the grey-scale values—between the corners 56 and 60 , which corresponds to a higher color saturation.
[0064] The transformed image signals R′, G′ and B′ for the colors red, green and blue, respectively, are in this case derived according to the transformation equations
R′=α R ·( R−L )+ L
G′=α G ·( G−L )+ L
B′=α B ·( B−L )+ L
[0065] from the logarithmically compressed image signals R, G and B, for which the following proportionality holds true:
R˜γ (log I R +log g )
G˜γ (log I G +log g )
B˜γ (log I B +log g )
[0066] In this case, g designates the gain factor whose logarithm was added to the image signals in the adder 34 . The quantities I R , I G and I B are the spectrally filtered irradiances which occur at the individual image cells of a pixel.
[0067] The brightness signals L are determined for each individual pixel by forming the arithmetic means of the image signals assigned to the individual spectral colors, i.e. the following holds true for the brightness signal L:
L = 1 3 · ( R + G + B ) .
[0068] In this case, a gain of the color saturation is produced only in the case of saturation factors which are greater than 1. If all the saturation factors α R , α G and α B are equal to 1, then the color saturation remains unchanged; on the other hand, if these saturation factors are less than 1, then the color saturation decreases until finally (all saturation factors=0) a pure grey-scale value image is produced.
[0069] In the case of the transformation indicated diagrammatically in FIG. 5, the saturation factors α R , α G and α B are identical, as a result of which the values for the transformed image signals lie within a circular cylinder. If these saturation factors are chosen differently, then this leads to cylinders with elliptical base areas. The choice of the saturation factors α R , α G and α B thus makes it possible, when increasing the color saturation, to generate additional color accentuations which enable the recorded images to be adapted even better to the actual visual impression.
[0070] Moreover, in the case of the transformation shown in FIG. 5, the saturation factors α R , α G and α B are constants which may be defined by a user of the digital camera 10 , but do not depend on further variables. This means that the equations specified above for the transformed image signals R′, G′ and B′ are linear. However, it is equally possible to make the saturation factors α R , α G and α B functionally dependent on other variables.
[0071] [0071]FIG. 6 shows a color cube 40 in which a frustum 68 is depicted concentrically with respect to the spatial diagonal between the corners 56 and 60 , the vertex of the frustum 68 coinciding with the corner 56 . The frustum 68 reproduces the range of values of a transformation in which the saturation factors α R , α G and α B are a function of the brightness, so that
α R =α R ( L )
α G =α G ( L )
α B =α B ( L )
[0072] As a result of the introduction of brightness-dependent saturation factors, the transformation equations specified above are thus no longer linear with respect to the brightness signal L.
[0073] In the exemplary embodiment illustrated in FIG. 6, the relationship between the saturation factors α R , α G and α B and the brightness L is linear, i.e.
α R =k R ·L
α G =k G ·L
α B =k B ·L
[0074] where k R , k G and k B are positive proportionality constants. If the proportionality constants k R , k G and k B are identical, the base area of the frustum is a circular area. This transformation with brightness-dependent saturation factors has the result that the saturation is increased to a greater extent, the higher the brightness at the relevant pixel. At low brightness, on the other hand, the color saturation is reduced and finally disappears completely for a brightness of L=0. In many cases, this transformation leads to a particularly natural image impression since color differences can hardly be made out anyway in dark image regions and for this reason the color saturation is even reduced there. On the other hand, bright regions often appear unnaturally pale, which is why the color saturation is raised to a particularly great extent there.
[0075] It is understood that FIGS. 4, 5 and 6 are merely diagrammatic in nature and the cylinders 64 and 66 illustrated there as well as the frustum 68 do not represent an exact reproduction of the range of values of the transformed image signals. In particular, for illustration reasons, the base areas of the cylinders and of the frustum are drawn within the color cube 40 . In reality, however, at least the corners 60 or points situated in the vicinity thereof lie within the range of values since it must be ensured, of course, that the color white is also represented correctly. Conversely, it is also possible, of course, for the range of values of the transformed image signals not to lie outside the color cube 40 . During the programming of the transformation, that is taken into account by additional normalization functions which need not be presented in detail here.
[0076] In addition or as an alternative to a dependence on the brightness values L, the saturation factors α R , α G and α B may also have a dependence on the contrast factor γ by which the overall signal is multiplied in the multiplier 36 prior to the transformation. FIG. 7 shows a graph in which, by way of example, the saturation factor α R for the color red is plotted against the contrast factor γ. The functional relationship between these two quantities is described by a monotonically falling and piecewise linear function. The contrast factor γ, whose value generally depends on the dynamic range of the image that is to be represented and can therefore change from image to image, is generally larger, the smaller the dynamic range of the recorded image. High contrast factors γ mean that the image overall gains in contrast and, as a result, the color saturation perceived by the viewer also increases. This fact is taken into account by the saturation factors α R , α G and α B decreasing as the gain increases in the manner illustrated in FIG. 7. A piecewise linear function leads to shorter computation times, but can equally, of course, be replaced by a different functional relationship.
[0077] [0077]FIG. 8 shows the construction of a saturation stage 38 in a strongly simplified manner. The saturation stage 38 is embodied as a digital signal processor 70 , which comprises a computing unit 72 and also a freely programmable ROM program memory 74 . A computer program which controls the performance of the transformation illustrated above in the computing unit 72 is stored in the program memory 74 . The digital signal processor 70 additionally has a volatile memory 76 , in which variables that can be modified by an operator, e.g. specifications with regard to the desired color saturation, can be stored. The digital signal processor 70 additionally has an input 78 , via which a conditioned overall signal to be transformed can be fed in, and also an output 80 for outputting the transformed image signals, e.g. to a screen 82 or an image memory.
[0078] It is understood that the saturation stage 38 can also be realized in other ways. It may e.g. also be situated outside a digital camera and then be embodied, for instance, as a personal computer into which a program for electronic image processing is loaded, which program controls the performance of the transformation discussed above by the processor of the personal computer. Furthermore, the saturation stage may also be realized as a digital or analogue electronic circuit.
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A method for the transformation of image signals that have been obtained by color filtering and have been logarithmically compressed is proposed. The color saturation of the recorded images is increased thereby. According to one aspect of the invention, the transformed image signals are determined as a function of the logarithmically compressed image signals and the logarithmically compressed brightness signals for a spectral color.
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ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA Contract and is subject to the provisions of Section 305 of the National Aeronautics & Space Act of 1958, Public Law 85-568 (72 STAT 435; 42 U.S.C. 2457).
BACKGROUND OF THE INVENTION
The invention generally relates to adsorption refrigeration systems and more particularly to a new symmetrical adsorption pump/compressor system combined with a Joule Thomson valve for providing a new, efficient refrigeration cycle.
DESCRIPTION OF THE PRIOR ART
Heretofore, long-life reliable refrigerators of relatively low mass and bulk generally have been unavailable. The lack of such refrigerators particularly has been recognized in the aerospace industry which requires reliability exceeding that of the mechanical refrigerators heretofore available in the marketplace. The lack of sufficient reliability results, at least in part, from the fact that mechanical refrigerators tend to fail because of an inherent degradation of moving parts and associated seals occuring during missions of long durations. Additionally, it generally is accepted that mechanical refrigerators tend to be of excessive bulk and mass and thus generally are found to be undesirable in many phases of the aerospace industry. Adsorption refrigerators, of course, are notoriously old.
In view of the foregoing, it should now be apparent that there currently exists a need for a serviceable and dependable system having high heat dissipating capabilities and yet adaptable for miniaturization for use in systems of types often encountered in the aerospace industry.
It is therefore the general purpose of the instant invention to provide an improved refrigeration system comprising a new symmetrical adsorption pump/compressor combined with a Joule Thomson valve through a use of which a refrigeration cycle of enhanced reliability is realized.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved refrigeration system characterized by increased reliability and with attendant reduction in mass and bulk.
It is another object to provide in an adsorption refrigeration system wherein a gas reversely is caused to flow through the system for thus enhancing the cooling capabilities thereof.
It is another object to provide a symmetrical adsorption refrigeration system with a Joule Thomson valve to provide a new refrigeration cycle characterized by an enhanced efficiency.
It is another object to provide an improved adsorption system the operation of which is controlled through a plurality of heat switches, such as gas heat switches.
Another object is to provide an improved adsorption refrigeration system which is particularly useful in the aerospace industry, although not necessarily restricted in use thereto since the refrigeration system may be employed in a terrestial environment wherein a high degree of efficiency is required, without attendant weight and bulk penalties being imposed.
It is another object to provide an improved gas heat switch having a capability for accommodating selective switching operations.
These together with other objects and advantages are achieved through a combination of a Joule Thomson valve with a symmetrical adsorption pump-compressor and a plurality of gas heat switches adapted selectively to apply heat from a thermal load and to discharge heat through a heat rejector, such as a radiator or the like, as will become more readily apparent by reference to the following description and claims in light of the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a system embodying the principles of the instant invention.
FIG. 2 is a schematic view depicting a heat switch coupled with a control circuit, as is employed in the system shown in FIG. 1.
FIG. 3 is a vertically sectioned, partially schematic view depicting the heat switch shown in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings with more particularity, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a system characterized by a symmetrical adsorption pump/compressor system, hereinafter referred to as an adsorption refrigeration system, generally designated 10, embodying the principles of the instant invention.
As hereinbefore mentioned, adsorption refrigeration systems are notoriously old. Further, the specific structure required and the modes of operations employed in successful operation of various system components as found in a conventional adsorption refrigeration system, generally are believed to be well known. Therefore, since the details of the conventional components form no part of the claimed invention, a detailed description of each of the components depicted in the drawings is neither deemed necessary nor desirable.
It suffices to understand that the system 10 includes a first adsorption chamber generally designated 12 and a second adsorption chamber, generally designated 14. In practice, each of the adsorption chambers is of known design and includes therein a suitable adsorbant, not shown. Suitable adsorbants, however, include Zeolite, charcoal, and metal hydrides utilized in a manner fully understood by those familiar with adsorption refrigerators.
It is to be understood that the system 10 is charged with a body of gas. Such a gas is characterized by a relatively high cooling capacity when expanded and is compatible with the particular adsorbant employed. One gas found suitable for use with the aforementioned adsorbants is helium. However, other gases may be employed equally as well, all without departing from the scope and spirit of the instant invention.
As shown, a pair of heater units, designated 16 and 18, are provided for selectively heating the adsorption chambers 12 and 14, respectively. For purposes of providing for a complete understanding of the instant invention, it may be assumed that the heaters 16 and 18 comprise resistance heaters.
Also, for the sake of providing for a complete understanding of the instant invention, there is depicted a heater control circuit 20 connected with each of the heaters 16 and 18 for purposes of controlling the operations thereof. However, it is important to note that heaters of other types can be employed equally as well. For example, depending upon prevailing temperatures and heat transfer capability required in a given environment for the system, the heaters 16 and 18 may constitute no more than thermal bridges coupled to sources of heat found to exist in the environment in which the system 10 is employed.
The system 10 also includes fluid conduits 22 and 24. These conduits are connected at the output side of the adsorption chambers 12 and 14 and serve to commonly connect thereto a pre-cooler, generally designated 26. The pre-cooler 26 is of any suitable design. Where so desired, the pre-cooler 26 may comprise a simple heat exchanger, such as a radiator or a refrigerator, driven by a suitable auxiliary system, not shown. Additionally, like the heaters 16 and 18, the pre-cooler 26 may constitute no more than a thermal bridge having a capability for delivering to the system's environment, heat extracted from the gas as it is caused to flow therethrough.
At the output side of the pre-cooler 26, there is provided a heat exchanger 28, also of known design. The design and function of the heat exchanger 28 is similar to the design and function of such devices found in conventional adsorption refrigeration systems.
Briefly, the heat exchanger 28 is coupled at the output side of the pre-cooler 26, through conduits 29 and 30, which permit gases flowing through the heat exchanger 28 to flow in cyclically reversing directions, as will hereinafter become more readily understood. The purpose for accommodating gas flow through the heat exchanger is to transfer heat from the gas for further cooling the gas as it is caused alternately to exit the adsorption chambers 12 and 14.
Connected to the output side of the heat exchanger 28, via conduits 32 and 34, there is a pair of expansion chambers, generally designated 36 and 38. The expansion chambers 36 and 38 also are of a design well known by those familiar with adsorption refrigeration systems. Therefore, a detailed description of these system components also is omitted in the interest of brevity. However, it is to be understood that while the expansion chambers 36 and 38, as herein employed, may be considered to comprise "free" expansion chambers, where so desired, conventional Joule Thomson valves may be employed for accommodating an expansion of the gas as it alternately is expelled into the expansion chambers 36 and 38.
Finally, interposed between the expansion chambers 36 and 38 there is a Joule Thomson expander, generally designated 40. The Joule Thomson expander, as employed, also is of conventional design and is characterized by a capability of accommodating a rapid expansion of gases, such as the capability which characterizes a conventional Joule Thomson valve. As shown, the Joule Thomson expander 40 is interposed between and connected with both of the expansion chambers 36 and 38 through conduits, designated 42a and 42b. As also will hereinafter be more readily apparent, a selected gas is cyclically caused to flow reversely through the expander 40 for purposes of further cooling the gas, prior to its alternate delivery, to a "downstream" expansion chamber, 36 or 38, as is dictated by the direction in which the gas is caused to flow through the expander 40.
At this juncture, it is important to note that the system 10 is interposed between a thermal load, designated 44, and a heat rejector, generally designated 46. The thermal load, of course, is, in operation, cooled by the system 10, while the heat rejector 46 simply serves as a heat discharge component for the elimination of thermal energy. In practice, the thermal load 44 may comprise any type of load found aboard a vehicle, such as electronic equipment found aboard space craft, while the heat rejector 46 comprises no more than a plate exposed to ambient temperatures.
It is at this juncture, important to note that both the thermal load 44 and the heat rejector 46 are connected to the system 10 via selectively operable gas heat switches, designated 48a, 48b, 48c and 48d, interposed in thermal conductors 49a, 49b, 49c, and 49d. Each of the heat switches 48a through 48d, in turn, are controlled through switch control circuits or components, designated 50a and 50b.
Since the heat switches 48a through 48d are of a similar design, a detailed description of a single one of the switches is deemed adequate for a complete understanding of the instant invention. Therefore, with reference to FIG. 2, it can be seen that the switch 48a comprises a substantially hermetically sealed unit connected with a further adsorption chamber 52 through a suitable conduit 54. The operation of adsorption chamber 52 is, in turn, controlled through an electrical control circuit 56. This circuit is of any suitable design, but as shown, FIG. 3, control of this circuit is obtained through conventional circuitry, designated 50a. Since the control circuit 56, as well as the control circuit 50a therefor, forms no part of the invention herein claimed, a more detailed description thereof is omitted in the interest of brevity.
Referring now to FIG. 3, however, it can be seen that the heat switch 48a includes a first thermal conductive member 58 and a second thermal conductive member 60. The members 58 and 60 are mutually spaced and are fabricated from any one of a myriad of metals, or similar materials, comprising good thermal conductors. The wall of the switch, designated 62, is fabricated from a material comprising a relatively poor thermal conductor, or thermal insulating material. A suitable material, such as thin glass, has been used with acceptable success. As shown, the wall 62 is of a cylindrical configuration while the members 58 and 60 conform to cylindrical plugs received in the opposite ends of the wall 62. Defined between the members 58 and 60 there is a pressure chamber 64. In practice, the thickness of the walls 62 and the axial dimension of the chamber 64 are minimized for thereby enhancing the system's efficiency.
As is well known, a chamber charged with a pressurized thermal conductive gas, such as helium, has a capability of conducting a thermal current from a first body to a relatively cooler second body. Accordingly, it is to be understood that an interruptable thermal path may be established between the members 58 and 60 simply by causing the chamber 64 to undergo pressurization, for thereby establishing a current path between the members 58 and 60, and subsequently to undergo evacuation for purposes of interrupting the thus established thermal path between the members. Thus a "switching" function is achieved.
As is also well-known, it is possible to cool an adsorbant for thus causing the adsorbant to adsorb a quantity of gas and later give up the gas in the presence of heat.
Hence, in order to achieve the desired pressurization and subsequent evacuation of the pressure chamber 64, the adsorption chamber 52 is connected to communicate with the pressure chamber 64 via a bore 66. As shown, the bore 66 is extended axially through the member 60. Where so desired, the conduit 54 is axially mated with the bore 66. Such is achieved in any suitable manner, such as through a use of a suitable coupling 68 received within one end of the bore 66. Since the particular manner in which the conduit 54 is coupled with the bore 66 forms no part of the claimed invention, a detailed description thereof is omitted in the interest of brevity.
It is important to note, however, that within the adsorption chamber 52 there is disposed a quantity of an adsorbant material, herein referred to as an adsorber, designated 70. The adsorber may be fabricated from Zeolite, charcoal, or a metal hydride. Additionally, it is to be understood that the chambers 52 and 64 are charged with a quantity of compatable, thermally conductive gas which is suited for adsorption by the particular adsorbant employed. Helium gas, not shown, and a Zeolite adsorbant may be employed satisfactorily as a suitable gas/adsorber combination.
At this juncture, it is noted that within the chamber 52 there is provided a device 72 for cooling the adsorber. While the device 72 comprises a cooling coil, as depicted, the cooling coil may be omitted in those instances where a thermal leak is sufficient for transferring a suitable flow of thermal energy from the adsorber 70 to an ambient environment.
Additionally, a heating device, such as a resistance heater 74, as shown, comprises a device suitable for heating the adsorber 70. Here again, it is possible to eliminate the resistance heater 74 in those instances where thermal energy may be delivered through other means to the adsorber 70 in sufficient quantities.
In practice, one manner in which the system is caused to function quite satisfactorily in a terrestial environment is to connect a thermal conductor between the adsorption chamber 52 and a source of low temperature which is sufficient to conduct heat from the adsorption chamber at a rate adequate for causing the adsorber 70 to adsorb the gas once the heater 74 is switched off. However, for the sake of providing for a complete understanding of the instant invention, it is to be understood that where so desired, the control circuit 56 also includes conventional circuit components having a capability of switching the adsorption chamber 52 between a desorbing, or system pressurizing mode, and an adsorbing, or system evacuating mode, for purposes of varying the thermal conductivity of the chamber 64.
In view of the foregoing, it should now be apparent that once the adsorber 70 is cooled to a low temperature, the body of gas contained in the chambers 64 and 52 is adsorbed by the adsorber 70. Consequently, there thus is established a sparsity of gas molecules in the chamber 64 so that the thermal conductivity of the chamber 64 is greatly reduced. However, upon a heating of the adsorber 70, the gas previously adsorbed is desorbed for again pressurizing the chambers 52 and 64 whereby the molecular population therein is increased. Thus, the thermal conductivity of the chamber 64 is greatly enhanced.
Hence, it should now be apparent that by controlling the heating and the cooling of the adsorber 70, through the heating element 74 and the cooling coil 72, or by other means, the thermal conductivity of the chamber 64 is varied and thus the thermal switch is switched between open and closed modes.
OPERATION
It is believed that in view of the foregoing description of the invention, the operation of the system 10 will readily by understood, however, in the interest of assuring a complete understanding of the invention and its operation, it will briefly be reviewed at this point.
With the adsorption refrigeration system 10 interconnected between the thermal load 44 and a heat rejector 46, the system is prepared for operation. A cycle of operation is hereinafter more fully described.
Initially, it is understood that when the switches 48a and 48c are open, the switches 48b and 48d will be closed. Opening and closing of the heat switches 48a through 48d is achieved by varying the temperature for the adsorber 70 within the adsorption chamber 52 of the switch control devices 50a and 50b. Assuming that the heater 16 initially is energized through a suitable activation by the heater control circuit 20, and further assuming that upon energization of the heater 16 the adsorbant contained within the adsorption chamber 12, not shown, is heated for thus causing the previously adsorbed gas contained therein to be discharged from the adsorption chamber, via the conduit 22. As the gas passes from the adsorption chamber 12 it is caused to pass through the pre-cooler 26 at which a pre-cooling of the gas occurs. The pre-cooled gas now continues to flow through the conduit 29 to the heat exchanger 28 and thence to the expansion chamber 36, via the conduit 32. Of course, the gas gives up heat in the heat exchanger 28 and undergoes further cooling at the expansion chamber 36. However, the gas exits the expansion chamber 36, via the conduit 42a, and is further expanded at the Joule Thomson expander 40 for a final cooling. Thereafter, the finally cooled gas is delivered to the expansion chamber 38, via the conduit 42b. However, at this point, the switch control 50b is operatively maintaining the switch 48d interposed between the thermal load 44 and the chamber 38 in a switch-closed condition. Consequently, a thermal path for heat is established from the thermal load 44 to the expansion chamber 38 via the heat switch 48d. The gas flowing from the expander 40 to the expansion chamber 38 is permitted to pick up heat, derived from the thermal load 44, and continues to flow toward the absorption chamber 14, via the conduit 34, the heat exchanger 28, the conduit 30 and the pre-cooler 26.
As the gas thus heated in the expansion chamber 38 is caused to pass through the heat exchanger 28, additional heat is picked up from the gas passing therethrough from the pre-cooler 26.
As the thus heated gas continues to flow from the heat exchanger 28, toward the adsorption chamber 14, it courses through the conduit 30 and thence to the pre-cooler 26, the conduit 24 and then to the adsorption chamber 14.
At this juncture, it is important to note that the heat switch 48b is maintained in a switch-closed condition by the switch control 50a for thus permitting heat to be transmitted from the adsorption chamber 14 to the heat rejector 46, via the heat switch 48b and the thermal conductor 49b. Thermal energy thus is conducted from the adsorption chamber 14 to the heat rejector 46 via the heat switch 48b and the thermal conductor 49b.
Of course, the heater 18 remains in a switch-off condition while the adsorbant confined therein serves to adsorb the body of gas, in response to a cooling of the adsorbant, as the thermal energy is transferred to the heat rejector 46 and thence to the ambient environment.
Once the body of gas within the system 10 is adsorbed within the adsorption chamber 14, the second half of the cycle of operation is initiated simply by opening the heat switches 48b and 48d while closing the heat switches 48a and 48c, employing the switch controls 50a and 50b in a suitable manner.
Additionally, the heater 16 is de-energized while the heater 18 is energized for purposes of accommodating a cooling of the adsorbant within the adsorption chamber 12 and a heating of the adsorbant within the adsorption chamber 14. As the adsorbant within the adsorption chamber 14 is heated, desorption of the gas is initiated, causing the gas to flow in a direction reverse to that described with respect to the first half-cycle of operation for the system 10.
Consequently, it will be appreciated that gas now flows from the chamber 14 through the pre-cooler 26, the heat exchanger 28, the expansion chamber 38 and is finally cooled at the Joule Thomson expander 40, prior to its delivery to the expansion chamber 36. The expansion chamber 36 now is being heated in response to the thermal load 44 being applied thereto via the thermal conduits 49c and the closed switch 48c. The heated gas now exits the expansion chamber 36 and continues to flow to the adsorption chamber 12, via the conduits 32, 29, and 22, while passing through the heat exchanger 28 and the pre-cooler 26. The thermal energy of the gas is now delivered to the heat rejector 46, via the thermal conduits 49a and the gas heat switch 48a. In response to a delivery of the thermal energy from the gas, the adsorbant within the chamber 12 cools for thus permitting the gas to be adsorbed. Thus the cycle of operation of the system is complete.
As hereinbefore described, the "opening" and "closing" of the gas heat switches 48a through 48d are controlled simply by controlling the temperature of the adsorber 70, for selectively pressurizing and de-pressurizing the chamber 64. Control of the temperature of the adsorber 70 is selectively controlled by imposing control over control circuit 56 utilizing the controller 50a and 50b.
In view of the foregoing, it is believed to be readily apparent that the invention hereinbefore described provides a practical and economic solution to the problems of enhancing the longevity, increasing efficiency, and reduing the mass and bulk of refrigeration systems. It is contemplated that the invention as hereinbefore described ultimately will find utility in micro-electronic industries.
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A symmetrical adsorption pump/compressor system having a pair of mirror image legs and a Joule Thomson expander 40, or valve, interposed between the legs thereof for providing a new, efficient refrigeration cycle. The system further includes a plurality of gas operational heat switches 48a, 48b, 48c, and 48d adapted selectively to transfer thereto heat from a thermal load 44 and to transfer or discharge heat therefrom through a heat projector 46, such as a radiator or the like. The heat switches comprise gas pressurizable chambers adapted for alternate pressurization in response to adsorption and desorption of a pressurizing gas confined therein.
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FIELD OF THE INVENTION
[0001] This invention relates to antenna tuning, particularly but not exclusively to tuning a patch antenna using a switch.
BACKGROUND
[0002] Patch antennas are well-known and are well-suited for use as internal antennas in mobile telephones, since they can be made relatively small.
[0003] The problem with patch antennas is the need to trade-off size and bandwidth, since, in general, the smaller the antenna, the smaller its bandwidth. Since antennas need to be small to fit within modern mobile telephones, a solution is required to the problem of providing sufficient bandwidth for effective operation, including operation across multiple bands. There are two possible approaches to solving this problem, the first being to use multiple antennas and the second being to use a variable tuning scheme, so that the antenna can be made to cover different frequency bands.
SUMMARY OF THE INVENTION
[0004] In accordance with the invention, there is provided a tunable antenna for a portable communications device, comprising an antenna arrangement comprising first and second spaced apart conductors, the first conductor comprising a radiating conductor and the second conductor comprising a ground plane, the radiating conductor including first and second feed points arranged such that a resonant frequency of the antenna arrangement when fed at the first feed point is different from a resonant frequency of the antenna arrangement when fed at the second feed point, further comprising a switch for switching between the first and second feed points.
[0005] According to the invention, there is further provided a tunable antenna for a portable communications device, comprising an antenna arrangement connectable to an antenna feed, the antenna arrangement comprising first and second spaced apart conductors, the first conductor comprising a radiating conductor and the second conductor comprising a ground plane, the radiating conductor including first and second feed points; and a capacitor having first and second terminals, said first terminal of said capacitor being connected to said first feed point, further comprising a switch arranged to selectively switch the antenna feed between said second terminal of said capacitor and said second feed point.
[0006] The invention further provides a method of tuning an antenna for a portable communications device, the antenna comprising first and second spaced apart conductors, the first conductor comprising a radiating conductor and the second conductor comprising a ground plane, the radiating conductor including first and second feed points arranged such that a resonant frequency of the antenna arrangement when fed at the first feed point is different from a resonant frequency of the antenna arrangement when fed at the second feed point, the method including switching an antenna feed between the first and second feed points.
DESCRIPTION OF THE DRAWINGS
[0007] Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings, in which:
[0008] [0008]FIG. 1 is a perspective view of a mobile telephone handset;
[0009] [0009]FIG. 2 is a rear view of the handset of FIG. 1;
[0010] [0010]FIG. 3 is a schematic diagram of mobile telephone circuitry for use in the telephone handset of FIG. 1;
[0011] [0011]FIG. 4 shows the structure of a tunable patch antenna in accordance with the invention;
[0012] [0012]FIG. 5 is a top view of the patch antenna element shown in FIG. 4;
[0013] [0013]FIG. 6 is a schematic diagram showing a simplified equivalent circuit for the antenna of FIG. 4;
[0014] [0014]FIG. 7 is a schematic diagram showing the circuit of FIG. 6 connected to an rf stage shown in FIG. 3 via a matrix switch;
[0015] [0015]FIG. 8 a is a schematic circuit diagram of the matrix switch shown in FIG. 7 in the first switching configuration shown in FIG. 10 a;
[0016] [0016]FIG. 8 b is a schematic circuit diagram of the matrix switch shown in FIG. 7 in the second switching configuration shown in FIG. 10 b;
[0017] [0017]FIG. 9 illustrates a method of tuning an antenna according to the invention;
[0018] [0018]FIG. 10 a is a schematic diagram illustrating a first switching configuration;
[0019] [0019]FIG. 10 b is a schematic diagram illustrating a second switching configuration;
[0020] [0020]FIG. 11 a is an equivalent circuit diagram corresponding to the first switching configuration illustrated in FIG. 10 a;
[0021] [0021]FIG. 11 b is an equivalent circuit diagram corresponding to the second switching configuration illustrated in FIG. 10 b;
[0022] [0022]FIG. 12 a is a Smith diagram for the first switching configuration;
[0023] [0023]FIG. 12 b is a Smith diagram for the second switching configuration; and
[0024] [0024]FIG. 13 illustrates the difference in resonant frequencies for each of the switching configurations shown in FIGS. 10 a and 10 b.
DETAILED DESCRIPTION
[0025] Referring to FIG. 1, a mobile station in the form of a mobile telephone handset 1 includes a microphone 2 , keypad 3 , with soft keys 4 which can be programmed to perform different functions, an LCD display 5 , a speaker 6 and a tunable patch antenna 7 which is contained within the housing. The location of the antenna 7 is illustrated in FIG. 2, which shows the back of the handset 1 with a rear cover 8 removed.
[0026] The mobile station 1 is operable in different configurations to communicate through cellular radio links with individual PLMNs (public land mobile network) shown schematically as PLMN A and PLMN B. PLMNs A and B may utilise different frequency bands. For example, PLMN A may be a GSM 1800 MHz network while PLMN B is a GSM 1900 MHz network.
[0027] Generally, the handset communicates over a cellular radio link with its home network PLMN A (shown as HPLMN) in a first configuration i.e. using a frequency band appropriate to PLMN A. However, when the user roams to PLMN B, one of the keys on the handset, for example, one of the soft keys 4 , may be operated to select a second operational configuration i.e. a frequency band associated with PLMN B.
[0028] [0028]FIG. 3 illustrates the major circuit components of the telephone handset 1 . Signal processing is carried out under the control of a digital micro-controller 9 which has an associated flash memory 10 . Electrical analogue audio signals are produced by microphone 2 and amplified by pre-amplifier 11 . Similarly, analogue audio signals are fed to the speaker 6 through an amplifier 12 . The micro-controller 9 receives instruction signals from the keypad and soft keys 3 , 4 and controls operation of the LCD display 5 .
[0029] Information concerning the identity of the user is held on a smart card 13 in the form of a GSM SIM card which contains the usual GSM international mobile subscriber identity (IMSI) and an encryption key K i that is used for encoding the radio transmission in a manner well known per se. The SIM card is removably received in a SIM card reader 14 .
[0030] The mobile telephone circuitry includes a codec 15 , an rf stage 16 and an antenna tuning circuit 17 feeding the tunable antenna 7 .
[0031] For example, for operation in a first frequency band, the codec 15 receives analogue signals from the microphone amplifier 11 , digitises them into a GSM signal format and feeds them to the rf stage 16 for transmission through the antenna 7 to PLMN A shown in FIG. 1. Similarly, signals received from PLMN A are fed through the antenna 7 to be demodulated in the rf stage 16 and fed to codec 15 , so as to produce analogue signals fed to the amplifier 12 and ear-piece 6 . The tuning circuit 17 tunes the antenna under the control of the controller 9 to the required frequency band for the operational configuration.
[0032] As mentioned above, with a conventional dual band/mode phone, when the user roams from the coverage area of PLMN A to PLMN B, the configuration suitable for PLMN B may be manually selected by means of a soft key 4 , or can be automatic if the coverage areas for PLMN A and B do not overlap.
[0033] Referring to FIG. 4, a tunable antenna 7 according to the invention comprises a conductive patch element 20 spaced 5 mm from a ground plane 21 which comprises the PCB to which the handset components are mounted. The ground plane 21 has a rectangular shape approximately 105 mm long by 40 mm wide. The space between the patch element 20 and the PCB 21 is filled with a dielectric material 22 , such as a PVC foam. The patch element 20 includes first and second feed points A, B.
[0034] A top view of the patch antenna element 20 is shown in FIG. 5. The patch antenna element 20 is, for example, a rectangular element which contains an approximately L-shaped cut-out 23 at one end. The cut-out starts along one of the shorter edges and comprises a rectangular stem portion which extends into an approximately rectangular body portion, one corner 24 of which is angled.
[0035] It will be understood that the shape of the cut-out affects the values of the inductances L 1 and L 2 and the capacitance Cp, so that the specified shape is given by way of example only and is limited only by the need to achieve particular values of capacitance and inductance to implement a given antenna circuit.
[0036] As mentioned above, two feed points respectively labelled A and B are situated along the first edge 23 of the antenna patch 20 on either side of the cut-out.
[0037] [0037]FIG. 6 is a schematic diagram showing a simplified equivalent circuit for the antenna structure of FIG. 4. The patch structure can be modelled as a reactive network comprising an inductor L 1 , one end of which is connected to feed point A, and an inductor L 2 , one end of which is connected to feed point B, the other ends of inductors L 1 and L 2 being connected to one end of a capacitor Cp, the other end of which is connected to ground.
[0038] [0038]FIG. 7 shows the connection of the rf stage 16 to the antenna 7 via a tuning circuit 17 which comprises a switch, for example, a matrix switch. The antenna 7 is represented by its equivalent circuit as shown in FIG. 6. An antenna feed 24 is connected to a first switch port 25 on a first switching side of the matrix switch 17 .
[0039] A second switch port 26 on the first switching side of the matrix switch is earthed. A third switch port 27 on a second switching side of the matrix switch is connected to feed point A of the antenna 7 . A fourth switch port 28 on the second switching side of the matrix switch is connected to the second feed point B of the antenna 7 via a series capacitance Ci. It will be understood that the antenna feed 24 can be an output from the rf stage 16 , for example a power amplifier output, or can comprise the rf stage receive circuitry for receiving signals picked up by the antenna 7 . For signals fed from the rf stage to the antenna 7 , the first and second switch ports comprise input ports and the third and fourth switch ports comprise output ports, whereas for signals fed from the antenna 7 to the rf stage 16 , the first and second switch ports comprise output ports and the third and fourth switch ports comprise input ports.
[0040] [0040]FIGS. 8 a and 8 b are schematic diagrams of the matrix switch shown in FIG. 7, in two different switching configurations. As shown in the Figures, the matrix switch 17 comprises a switching arrangement of diodes D 1 -D 4 , inductors L 3 -L 6 , resistors R 1 -R 4 and switches S 1 and S 2 . The switches S 1 and S 2 are arranged to provide different switching configurations between the input ports 25 , 26 and the output ports 27 , 28 .
[0041] The tuning operation for the antenna 7 will now be described in detail, with reference to FIG. 9.
[0042] When tuning is required, for example to switch between networks operating in different frequency bands, a user selects a band A or B by using a soft key 4 (step s 1 ). If he selects band A (step s 2 ), the controller 9 switches the matrix switch 17 to a first switching configuration (step s 3 ).
[0043] [0043]FIG. 10 a is a schematic diagram illustrating the first switching configuration. In this configuration, indicated by the dotted lines within the matrix switch, the output of the rf circuit is connected to feed point A while feed point B is connected to ground via the capacitor Ci. The equivalent circuit diagram for this configuration is shown in FIG. 11 a while FIG. 12 a shows the corresponding Smith diagram.
[0044] If the user selects operating mode B (step s 2 ), the controller 9 switches the matrix switch 17 to a second switching configuration (step s 4 ).
[0045] [0045]FIG. 10 b is a schematic diagram illustrating the second switching configuration. In this configuration, the rf stage is connected to feed point B via the capacitor Ci, while feed point A is connected directly to ground. The equivalent circuit diagram corresponding to this configuration is shown in FIG. 11 b, while FIG. 12 b shows the Smith diagram for this configuration.
[0046] Once the frequency band has been selected and the switch position correspondingly set (steps s 2 -s 4 ), handset transmit/receive operation continues with the new settings (step s 5 ).
[0047] The equivalent circuit diagrams in FIGS. 11 a and 11 b show that the input impedance of the antenna circuit 7 differs for each configuration, leading to a difference in resonant frequencies for each configuration, as illustrated in FIG. 13.
[0048] For the first switching arrangement which corresponds to the plot shown as first plot 30 , the resonant frequency of the antenna is 1.205 GHz, whereas for the second switching arrangement corresponding to second plot 31 , the resonant frequency is 1.181 GHz. By tuning the frequency shift into the appropriate frequency bands, an antenna according to the invention can be used for switching between the GSM 1800/1900 frequency bands, as well as for switching between the frequencies used for the receive/transmit channels.
[0049] It will be understood that while the antenna arrangement has been described with detailed dimensions and relative arrangement of conductive plates, this is merely a specific example of the invention, and modifications to the structure, dimensions and precise arrangement of the components which do not alter the principles of operation also fall within the scope of this invention.
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A patch antenna is provided with two feed points, one on either side of a cut-out. Both feed points are connected to the ports on a first side of a matrix switch, one directly and one via a capacitor. An antenna feed is connected to one of the ports on a second side of the matrix switch, while the other is earthed. In use, a controller operates the switch so that the antenna feed is connected one or other of the feed points, each giving rise to a different resonant frequency and so providing a way of tuning the antenna for small frequency shifts.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of session establishment. More particularly, the present invention relates to the establishment and maintenance of video communications within a combined environment of mobile and fixed line networks.
BACKGROUND OF THE INVENTION
[0002] Over past years, the level of technology in the field of video conferencing has advanced significantly. In recent years video conferencing has become very common in business settings, permitting meetings to take place in an interconnected manner in multiple locations around the world. Developments have also been made in the area of “video” telephone calls. However, although video conferencing and video calling have improved recently, they still suffer from several drawbacks.
[0003] In the Internet, it is difficult to make point-to-point connections between individual users and/or user devices. The main reason for this difficulty is the fact that there are currently no global identifiers for users within the Internet that can be utilized to create a connection. For example, electronic mail addresses are global, but they do not identify a current user of a device. Although internet protocol (IP) addresses are used in the Internet, IP addresses are not always static in nature. Instead, parts of IP address space are allocated dynamically, which means that IP addresses are of limited use for identifying network nodes. Also, IP addresses serve as location information for machines, not for users. Additionally, there are currently no directory services available in the Internet that enable a person or a device to request an IP address of a specific individual person. Furthermore, video calls also currently often require that the two call participants use the same service provider, and the participants'communication parameters and firewall arrangements must be precisely prepared before a working session can be established. Therefore, even though there is sufficient bandwidth on the Internet to allow the making of video calls over the Internet, it is difficult to use the Internet for such calls due to this lack of addressability.
[0004] On the other hand, within telecommunication networks, there are globally reachable addresses available to users. These addresses currently take the form of telephone numbers according to the ITU-T E. 164 standard and, in the future, Session Initiation Protocol (SIP) addresses will also be available. The Session Initiation Protocol is an Internet engineering Task Force standard protocol for establishing, modifying and tearing down interactive sessions that involve multimedia elements such as audio, video, instant messaging, or other real time data communications.
[0005] The availability of telephone numbers and SIP addresses enables telecommunication users to establish sessions, such as voice calls, or to send messages, such as short messaging system (SMS) messages or instant messages (IMs) between users. However, in mobile networks, there is usually not enough bandwidth to conduct high quality, real time sessions for video calls. Furthermore, even if sufficient bandwidth was readily available, such as in wideband code division multiple access (WCDMA) networks, the cost of such bandwidth sessions could be prohibitive.
[0006] Another problem related to video calls in mobile devices is the small display size. In most mobile devices currently available, there are not enough pixels on the display screen to show high quality video, and the physical size of the display adversely affects usability and the impressiveness of the video call.
SUMMARY OF THE INVENTION
[0007] The present invention provides for an improved system and method for enabling communication between terminals by taking advantage of the best aspects of both fixed line Internet networks and mobile networks. Devices connectable to a mobile network are used to establish connections between devices connected to a fixed line network. Telecommunications signaling is used in the first phase of the connection process between two users. This signaling is used to negotiate connection parameters relating to a fixed line session. A second phase involves the communication of the parameters to the respective devices that are connected to the Internet or other fixed line system. Based upon these parameters, the device that is connected to the Internet or other fixed line network can establish a session with the other endpoint connected to the Internet or other fixed line network.
[0008] The present invention provides for a number of benefits to users of the system. The present invention eliminates the issue of a lack of globally routable IP addresses associated with the Internet, while also taking advantage of the Internet's high-bandwidth capabilities.
[0009] These and other objects, advantages and features of the invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a generic system within which the present invention may be implemented;
[0011] FIG. 2 is a system exhibiting one embodiment of the present invention;
[0012] FIG. 3 is a perspective view of a mobile telephone that can be used in the implementation of the present invention;
[0013] FIG. 4 is a schematic representation of the telephone circuitry of the mobile telephone of FIG. 3 ; and
[0014] FIG. 5 is a flow chart showing the implementation of one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The present invention provides an improved system and method for enabling video calling between users by taking advantage of the benefits inherent in both mobile networks and fixed line networks such as the Internet.
[0016] FIG. 1 is a representation of a generic system within which the present invention may be implemented. The system of FIG. 1 includes a video session gateway device 100 , also referred to as a video telephony gateway device, with a broadband connection 140 associated therewith. The video session gateway device 100 has Internet connectivity and is configured so as to be capable of establishing a video session with another video session gateway device 100 over the broadband connection 140 using, for example SIP signaling, and normal video codecs.
[0017] The video session gateway device 100 communicates with a mobile telephone 110 or other mobile device over a local link. The local link can take a variety of forms, such as a Bluetooth connection, a wireless local area network (WLAN) connection, a cable connection or others. The video session gateway device 100 captures a video stream from a video capture device 160 , such as a camera or other data capturing device, or signals the session parameters to the video capture device 160 . The video session gateway device 100 also includes a video output for transferring video to be shown on a display device 170 , such as an integrated display, or a similar data rendering device. It should also be noted that, in a case where a user does not have a separate video session gateway device 100 , the mobile telephone 110 or other mobile device can serve as the video session gateway device 100 .
[0018] The broadband connection 140 can take the form of an Asymmetric Digital Subscriber Line (ADSL) or some other type of Internet connection that enables a high quality video connection. The video capture device 160 serves as the camera for the video call. The video capture device 160 can be connected to the video session gateway device as an accessory, it can be part of the video session gateway device 100 , or it can be a standalone web-cam connected to internet.
[0019] The display device 170 is used to show the video call. The display device 170 can take a variety of forms. For example, the display device 170 can be a regular television, a dedicated display, or an integrated display. A variety of audio input/output devices 150 can also be connected to the video session gateway device 100 .
[0020] The mobile device 110 includes a session establishment application 120 to set up the preliminary connection between users using signaling systems, such as SMS, multimedia message service (MMS), SIP or others, over the cellular network 130 of the mobile device 110 . The mobile device 110 communicates with the video session gateway device 100 over the local link. In other words, the mobile device transmits video session parameters to the video session gateway device 100 after the session parameters have been preliminarily negotiated between mobile devices.
[0021] FIG. 2 is a system that shows additional detail of one embodiment of the present invention. FIG. 2 shows the video session gateway device 100 connected to the Internet 180 via a broadband connection 140 . A local connection 190 connects the video session gateway device 100 to a mobile telephone 110 . The mobile telephone 110 transmits session invitations to a potential recipient via its respective cellular network 130 through the use of session invitations 200 . A camera/video capture device 160 and a display 170 are also operatively connected to the video session gateway device 100 .
[0022] FIGS. 3 and 4 show one representative mobile telephone 110 within which the present invention may be implemented. It should be understood, however, that the present invention is not intended to be limited to one particular type of mobile telephone 110 or other electronic device. For example, the present invention can be incorporated into a combination personal digital assistant (PDA) and mobile telephone, a PDA, an integrated messaging device (IMD), a desktop computer, and a notebook computer. The mobile telephone 110 of FIGS. 1 and 2 includes a housing 30 , a display 32 in the form of a liquid crystal display, a keypad 34 , a microphone 36 , an ear-piece 38 , a battery 40 , an infrared port 42 , an antenna 44 , a smart card 46 in the form of a universal integrated circuit card (UICC) according to one embodiment of the invention, a system clock 43 , a card reader 48 , radio interface circuitry 52 , codec circuitry 54 , a controller 56 and a memory 58 . A motion sensor 60 is also operatively connected to the controller 56 . Individual circuits and elements are all of a type well known in the art, for example in the Nokia range of mobile telephones.
[0023] The communication devices may communicate using various transmission technologies including, but not limited to, Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Transmission Control Protocol/Internet Protocol (TCP/IP), Short Messaging Service (SMS), Multimedia Messaging Service (MMS), e-mail, Instant Messaging Service (IMS), Bluetooth, IEEE 802.11, etc.
[0024] FIG. 5 is a flow chart showing the steps involved in one implementation of the present invention. At step 500 , a first user initiates a session establishment application in his or her mobile telephone 110 or other terminal. At this time, the first user should be in a location so that the first user's terminal and the first user's video session gateway device 100 are in the same general vicinity. At this point, the establishment application displays the first user's phonebook entries. At step 510 , the first user selects a phonebook entry for a second user. At step 520 , the selection triggers a specific invitation message to be sent to the second user's terminal. The specific invitation message can take a variety of forms, including, but not limited to a SMS message. This invitation can also include address information or other parameters for the first user's video session gateway device 100 . At step 530 , the second user's terminal receives the invitation and, at step 540 , a session establishment application is initiated. The session establishment application informs the second user that there is a video call invitation from the first user.
[0025] At step 550 , the second user accepts the invitation. At step 560 , the second user's terminal requests communication parameters from its video session gateway device 100 over the local link and builds a specific reply message to be sent to the first user's mobile telephone. This reply includes the requested communication parameters, which include, for example, an IP address, DNS name, or protocol- and application-level information such as TCP/UDP port or codec version. The second user's terminal can also include its own communication parameters in the reply message in a situation where the second user desires that the video connection is to be transmitted directly to the second user's terminal. The reply message is transmitted at step 570 . At step 580 , the first user's mobile telephone informs the first user that the second user has accepted the call. At step 590 , the first user's mobile telephone transfers the communication parameters to its video session gateway device 100 over the respective local link. At this point, the first and second users are ready to start an actual video session between the respective video session gateway devices using the received communication parameters. The session can be established using, for example, SIP signaling and normal video codecs. A television or other display device can be used for the received video. At this point, if both the first and second users are using video session gateway devices, the respective mobile terminals are no longer necessary for the call to proceed. Alternatively, it is also possible that a portion of the media is continued to be transmitted over the cellular network, while the rest of the media is transmitted over the fixed line network. For example, it is possible for the fixed line network to carry the video transmission between the parties, while the cellular network carries the audio transmission.
[0026] In the video telephony case, it should be noted that many of the functionalities of the present invention can be combined as necessary or desired. For example, the gateway functionality can be incorporated into a mobile telephone 110 . As an example only, a the mobile telephone can include WLAN and TV-out interfaces, permitting the mobile telephone to serve as the video system gateway device. Other arrangements are also possible for combining various functionalities.
[0027] Furthermore, it should also be noted that the present invention is not strictly limited to communication involving video telephony, but instead can be for virtually any type of mobile-assisted session establishment. For example, the present invention can also be used to establish video gaming sessions and other types of sessions.
[0028] The present invention is described in the general context of method steps, which may be implemented in one embodiment by a program product including computer-executable instructions, such as program code, executed by computers in networked environments.
[0029] Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps.
[0030] Software and web implementations of the present invention could be accomplished with standard programming techniques with rule-based logic and other logic to accomplish the various database searching steps, correlation steps, comparison steps and decision steps. It should also be noted that the words “component” and “module” as used herein, and in the claims, is intended to encompass implementations using one or more lines of software code, and/or hardware implementations, and/or equipment for receiving manual inputs.
[0031] The foregoing description of embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the present invention. The embodiments were chosen and described in order to explain the principles of the present invention and its practical application to enable one skilled in the art to utilize the present invention in various embodiments and with various modifications as are suited to the particular use contemplated.
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A system and method for providing mobile assisted, fixed line communication. A device connectable to a mobile network coordinates with a session gateway device that is connected to a fixed line network in order to establish a connection to another gateway device. Signaling over a cellular or other non-fixed line network is used to establish connection parameters relating to a fixed line session. The established connection parameters are transmitted to the respective session gateway devices. Based upon these parameters, the session gateway devices can directly communicate with each other over the Internet or other fixed line network.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional of application Ser. No. 12/139,100, filed on Jun. 13, 2008, which is a divisional of application Ser. No. 11/702,810, filed on Feb. 6, 2007, now U.S. Pat. No. 7,472,589 B1, issued Jan. 6, 2009, which is a continuation-in-part of application Ser. No. 11/438,764, filed on May 23, 2006, which is a continuation-in-part of application Ser. No. 11/268,311, filed on Nov. 7, 2005, now U.S. Pat. No. 7,197,923 B1, issued Apr. 3, 2007.
TECHNICAL FIELD OF THE INVENTION
This invention relates, in general, to testing and evaluation of subterranean formation fluids and, in particular to, a single phase fluid sampling apparatus for obtaining multiple fluid samples and maintaining the samples near reservoir pressure via a common pressure source during retrieval from the wellbore and storage on the surface.
BACKGROUND OF THE INVENTION
Without limiting the scope of the present invention, its background is described with reference to testing hydrocarbon formations, as an example.
It is well known in the subterranean well drilling and completion art to perform tests on formations intersected by a wellbore. Such tests are typically performed in order to determine geological or other physical properties of the formation and fluids contained therein. For example, parameters such as permeability, porosity, fluid resistivity, temperature, pressure and bubble point may be determined. These and other characteristics of the formation and fluid contained therein may be determined by performing tests on the formation before the well is completed.
One type of testing procedure that is commonly performed is to obtain a fluid sample from the formation to, among other things, determine the composition of the formation fluids. In this procedure, it is important to obtain a sample of the formation fluid that is representative of the fluids as they exist in the formation. In a typical sampling procedure, a sample of the formation fluids may be obtained by lowering a sampling tool having a sampling chamber into the wellbore on a conveyance such as a wireline, slick line, coiled tubing, jointed tubing or the like. When the sampling tool reaches the desired depth, one or more ports are opened to allow collection of the formation fluids. The ports may be actuated in variety of ways such as by electrical, hydraulic or mechanical methods. Once the ports are opened, formation fluids travel through the ports and a sample of the formation fluids is collected within the sampling chamber of the sampling tool. After the sample has been collected, the sampling tool may be withdrawn from the wellbore so that the formation fluid sample may be analyzed.
It has been found, however, that as the fluid sample is retrieved to the surface, the temperature of the fluid sample decreases causing shrinkage of the fluid sample and a reduction in the pressure of the fluid sample. These changes can cause the fluid sample to approach or reach saturation pressure creating the possibility of asphaltene deposition and flashing of entrained gasses present in the fluid sample. Once such a process occurs, the resulting fluid sample is no longer representative of the fluids present in the formation. Therefore, a need has arisen for an apparatus and method for obtaining a fluid sample from a formation without degradation of the sample during retrieval of the sampling tool from the wellbore. A need has also arisen for such an apparatus and method that are capable of maintaining the integrity of the fluid sample during storage on the surface.
SUMMARY OF THE INVENTION
The present invention disclosed herein provides a single phase fluid sampling apparatus and a method for obtaining fluid samples from a formation without the occurrence of phase change degradation of the fluid samples during the collection of the fluid samples or retrieval of the sampling apparatus from the wellbore. In addition, the sampling apparatus and method of the present invention are capable of maintaining the integrity of the fluid samples during storage on the surface.
In one aspect, the present invention is directed to an apparatus for obtaining a plurality of fluid samples in a subterranean well that includes a carrier, a plurality of sampling chambers and a pressure source. In one embodiment, the pressure source is selectively in fluid communication with at least two sampling chambers thereby serving as a common pressure source to pressurize fluid samples obtained in the at least two sampling chambers. In another embodiment, the carrier has a longitudinally extending internal fluid passageway forming a smooth bore and a plurality of externally disposed chamber receiving slots. Each of the sampling chambers is positioned in one of the chamber receiving slots of the carrier. The pressure source is selectively in fluid communication with each of the sampling chambers such that the pressure source is operable to pressurize each of the sampling chambers after the fluid samples are obtained.
In another aspect, the present invention is directed to a method for obtaining a plurality of fluid samples in a subterranean well. The method includes the steps of positioning a fluid sampler in the well, obtaining a fluid sample in each of a plurality of sampling chambers of the fluid sampler and pressurizing each of the fluid samples using a pressure source of the fluid sampler that is in fluid communication with each of the sampling chambers.
In a further aspect, the present invention is directed to an apparatus for obtaining a fluid sample in a subterranean well. The apparatus includes a housing having a sample chamber defined therein. The sample chamber is selectively in fluid communication with the exterior of the housing and is operable to receive the fluid sample therefrom. A debris trap piston is slidably disposed within the housing. The debris trap piston includes a debris chamber and, responsive to the fluid sample entering the sample chamber, the debris trap piston receives a first portion of the fluid sample in the debris chamber then displaces relative to the housing to expand the sample chamber.
In one embodiment, the debris trap piston includes a passageway having a cross sectional area that is smaller than the cross sectional area of the debris chamber. In this embodiment, the first portion of the fluid sample passes from the sample chamber through the passageway to enter the debris chamber. Also in this embodiment, the first portion of the fluid sample is retained in the debris chamber due to pressure from the sample chamber applied to the debris chamber through the passageway. Alternatively or additionally, a check valve may be disposed in an inlet portion of the debris trap piston to retain the first portion of the fluid sample in the debris chamber.
In another embodiment, the debris trap piston may include a first piston section and a second piston section that is slidable relative to the first piston section such that the debris chamber is expandable responsive to the fluid sample entering the debris chamber. In this embodiment, as engagement device may be disposed between the first piston section and the second piston section to prevent additional movement of the first piston section relative to the second piston section after expanding the debris chamber to a preselected volume.
In an additional aspect, the present invention is directed to a method for obtaining a fluid sample in a subterranean well. The method includes the steps of disposing a sampling chamber within the subterranean well, actuating the sampling chamber such that a sample chamber within the sampling chamber is in fluid communication with the exterior of the sampling chamber, receiving a first portion of the fluid sample in a debris chamber of a debris trap piston slidably disposed within the sampling chamber, displacing the debris trap piston within the sampling chamber to expand the sample chamber and receiving the remainder of the fluid sample in the sample chamber.
The method may also include passing the first portion of the fluid sample through the sample chamber and through a passageway of the debris trap piston before entering the debris chamber and retaining the first portion of the fluid sample in the debris chamber by applying pressure from the sample chamber to the debris chamber through the passageway. Additionally or alternatively, a check valve disposed in an inlet portion of the debris trap piston may be used to retain the first portion of the fluid sample in the debris chamber.
In certain embodiments, the method may include expanding the debris chamber responsive to the fluid sample entering the debris chamber by sliding a first piston section relative to a second piston section and preventing additional movement of the first piston section relative to the second piston section after expanding the debris chamber to a preselected volume.
In yet another aspect, the present invention is directed to a downhole tool including a housing having a longitudinal passageway. A piston, including a piercing assembly, is disposed within the longitudinal passageway. A valving assembly is also disposed within the longitudinal passageway. The valving assembly includes a rupture disk that is initially operable to maintain a differential pressure thereacross. The valving assembly is actuated by longitudinally displacing the piston relative to the valving assembly such that at least a portion of the piercing assembly travels through the rupture disk, thereby allowing fluid flow therethrough.
In one embodiment, the piercing assembly includes a piercing assembly body and a needle that is held within the piercing assembly body by compression. In this embodiment, the needle has a sharp point that travels through the rupture disk. In addition, the needle may have a smooth outer surface, a fluted outer surface, a channeled outer surface or a knurled outer surface. In certain embodiments, the valving assembly may include a check valve that allows fluid flow in a first direction and prevents fluid flow in a second direction through the valving assembly once the valving assembly is actuated by the piercing assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, including its features and advantages, reference is now made to the detailed description of the invention, taken in conjunction with the accompanying drawings in which like numerals identify like parts and in which:
FIG. 1 is a schematic illustration of a fluid sampler system embodying principles of the present invention;
FIGS. 2A-H are cross-sectional views of successive axial portions of one embodiment of a sampling section of a sampler embodying principles of the present invention;
FIGS. 3A-E are cross-sectional views of successive axial portions of actuator, carrier and pressure source sections of a sampler embodying principles of the present invention;
FIG. 4 is a cross-sectional view of the pressure source section of FIG. 3C taken along line 4 - 4 ;
FIG. 5 is a cross-sectional view of the actuator section of FIG. 3A taken along line 5 - 5 ;
FIG. 6 is a schematic view of an alternate actuating method for a sampler embodying principles of the present invention;
FIG. 7 is a schematic illustration of an alternate embodiment of a fluid sampler embodying principles of the present invention;
FIG. 8 is a cross-sectional view of the fluid sampler of FIG. 7 taken along line 8 - 8 ; and
FIGS. 9A-G are cross-sectional views of successive axial portions of another embodiment of a sampling section of a sampler embodying principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the invention.
Referring initially to FIG. 1 , therein is representatively illustrated a fluid sampler system 10 and associated methods which embody principles of the present invention. A tubular string 12 , such as a drill stem test string, is positioned in a wellbore 14 . An internal flow passage 16 extends longitudinally through tubular string 12 .
A fluid sampler 18 is interconnected in tubular string 12 . Also, preferably included in tubular string 12 are a circulating valve 20 , a tester valve 22 and a choke 24 . Circulating valve 20 , tester valve 22 and choke 24 may be of conventional design. It should be noted, however, by those skilled in the art that it is not necessary for tubular string 12 to include the specific combination or arrangement of equipment described herein. It is also not necessary for sampler 18 to be included in tubular string 12 since, for example, sampler 18 could instead be conveyed through flow passage 16 using a wireline, slickline, coiled tubing, downhole robot or the like. Although wellbore 14 is depicted as being cased and cemented, it could alternatively be uncased or open hole.
In a formation testing operation, tester valve 22 is used to selectively permit and prevent flow through passage 16 . Circulating valve 20 is used to selectively permit and prevent flow between passage 16 and an annulus 26 formed radially between tubular string 12 and wellbore 14 . Choke 24 is used to selectively restrict flow through tubular string 12 . Each of valves 20 , 22 and choke 24 may be operated by manipulating pressure in annulus 26 from the surface, or any of them could be operated by other methods if desired.
Choke 24 may be actuated to restrict flow through passage 16 to minimize wellbore storage effects due to the large volume in tubular string 12 above sampler 18 . When choke 24 restricts flow through passage 16 , a pressure differential is created in passage 16 , thereby maintaining pressure in passage 16 at sampler 18 and reducing the drawdown effect of opening tester valve 22 . In this manner, by restricting flow through choke 24 at the time a fluid sample is taken in sampler 18 , the fluid sample may be prevented from going below its bubble point, i.e., the pressure below which a gas phase begins to form in a fluid phase. Circulating valve 20 permits hydrocarbons in tubular string 12 to be circulated out prior to retrieving tubular string 12 . As described more fully below, circulating valve 20 also allows increased weight fluid to be circulated into wellbore 14 .
Even though FIG. 1 depicts a vertical well, it should be noted by one skilled in the art that the fluid sampler of the present invention is equally well-suited for use in deviated wells, inclined wells or horizontal wells. As such, the use of directional terms such as above, below, upper, lower, upward, downward and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure.
Referring now to FIGS. 2A-2H and 3 A- 3 E, a fluid sampler including an exemplary fluid sampling chamber and an exemplary carrier having a pressure source coupled thereto for use in obtaining a plurality of fluid samples that embodies principles of the present invention is representatively illustrated and generally designated 100 . Fluid sampler 100 includes a plurality of the sampling chambers such sampling chamber 102 as depicted in FIG. 2 . Each of the sampling chambers 102 is coupled to a carrier 104 that also includes an actuator 106 and a pressure source 108 as depicted in FIG. 3 .
As described more fully below, a passage 110 in an upper portion of sampling chamber 102 (see FIG. 2A ) is placed in communication with a longitudinally extending internal fluid passageway 112 formed completely through fluid sampler 100 (see FIG. 3 ) when the fluid sampling operation is initiated using actuator 106 . Passage 112 becomes a portion of passage 16 in tubular string 12 (see FIG. 1 ) when fluid sampler 100 is interconnected in tubular string 12 . As such, internal fluid passageway 112 provides a smooth bore through fluid sampler 100 . Passage 110 in the upper portion of sampling chamber 102 is in communication with a sample chamber 114 via a check valve 116 . Check valve 116 permits fluid to flow from passage 110 into sample chamber 114 , but prevents fluid from escaping from sample chamber 114 to passage 110 .
A debris trap piston 118 separates sample chamber 114 from a meter fluid chamber 120 . When a fluid sample is received in sample chamber 114 , piston 118 is displaced downwardly. Prior to such downward displacement of piston 118 , however, piston section 122 is displaced downwardly relative to piston section 124 . In the illustrated embodiment, as fluid flows into sample chamber 114 , an optional check valve 128 permits the fluid to flow into debris chamber 126 . The resulting pressure differential across piston section 122 causes piston section 122 to displace downward, thereby expanding debris chamber 126 .
Eventually, piston section 122 will displace downward sufficiently far for a snap ring, C-ring, spring-loaded lugs, dogs or other type of engagement device 130 to engage a recess 132 formed on piston section 124 . Once engagement device 130 has engaged recess 132 , piston sections 122 , 124 displace downwardly together to expand sample chamber 114 . The fluid received in debris chamber 126 is prevented from escaping back into sample chamber 114 by check valve 128 in embodiments that include check valve 128 . In this manner, the fluid initially received into sample chamber 114 is trapped in debris chamber 126 . This initially received fluid is typically laden with debris, or is a type of fluid (such as mud) which it is not desired to sample. Debris chamber 126 thus permits this initially received fluid to be isolated from the fluid sample later received in sample chamber 114 .
Meter fluid chamber 120 initially contains a metering fluid, such as a hydraulic fluid, silicone oil or the like. A flow restrictor 134 and a check valve 136 control flow between chamber 120 and an atmospheric chamber 138 that initially contains a gas at a relatively low pressure such as air at atmospheric pressure. A collapsible piston assembly 140 in chamber 138 includes a prong 142 which initially maintains another check valve 144 off seat, so that flow in both directions is permitted through check valve 144 between chambers 120 , 138 . When elevated pressure is applied to chamber 138 , however, as described more fully below, piston assembly 140 collapses axially, and prong 142 will no longer maintain check valve 144 off seat, thereby preventing flow from chamber 120 to chamber 138 .
A floating piston 146 separates chamber 138 from another atmospheric chamber 148 that initially contains a gas at a relatively low pressure such as air at atmospheric pressure. A spacer 150 is attached to piston 146 and limits downward displacement of piston 146 . Spacer 150 is also used to contact a stem 152 of a valve 154 to open valve 154 . Valve 154 initially prevents communication between chamber 148 and a passage 156 in a lower portion of sampling chamber 102 . In addition, a check valve 158 permits fluid flow from passage 156 to chamber 148 , but prevents fluid flow from chamber 148 to passage 156 .
As mentioned above, one or more of the sampling chambers 102 and preferably nine of sampling chambers 102 are installed within exteriorly disposed chamber receiving slots 159 that circumscribe internal fluid passageway 112 of carrier 104 . A seal bore 160 (see FIG. 3B ) is provided in carrier 104 for receiving the upper portion of sampling chamber 102 and another seal bore 162 (see FIG. 3C ) is provided for receiving the lower portion of sampling chamber 102 . In this manner, passage 110 in the upper portion of sampling chamber 102 is placed in sealed communication with a passage 164 in carrier 104 , and passage 156 in the lower portion of sampling chamber 102 is placed in sealed communication with a passage 166 in carrier 104 .
In addition to the nine sampling chambers 102 installed within carrier 104 , a pressure and temperature gauge/recorder (not shown) of the type known to those skilled in the art can also be received in carrier 104 in a similar manner. For example, seal bores 168 , 170 in carrier 104 may be for providing communication between the gauge/recorder and internal fluid passageway 112 . Note that, although seal bore 170 depicted in FIG. 3C is in communication with passage 172 , preferably if seal bore 170 is used to accommodate a gauge/recorder, then a plug is used to isolate the gauge/recorder from passage 172 . Passage 172 is, however, in communication with passage 166 and the lower portion of each sampling chamber 102 installed in a seal bore 162 and thus servers as a manifold for fluid sampler 100 . If a sampling chamber 102 or gauge/recorder is not installed in one or more of the seal bores 160 , 162 , 168 , 170 then a plug will be installed to prevent flow therethrough.
Passage 172 is in communication with chamber 174 of pressure source 108 . Chamber 174 is in communication with chamber 176 of pressure source 108 via a passage 178 . Chambers 174 , 176 initially contain a pressurized fluid, such as a compressed gas or liquid. Preferably, compressed nitrogen at between about 7,000 psi and 12,000 psi is used to precharge chambers 174 , 176 , but other fluids or combinations of fluids and/or other pressures both higher and lower could be used, if desired. Even though FIG. 3 depicts pressure source 108 as having two compressed fluid chambers 174 , 176 , it should be understood by those skilled in the art that pressure source 108 could have any number of chambers both higher and lower than two that are in communication with one another to provide the required pressure source. As best seen in FIG. 4 , a cross-sectional view of pressure source 108 is illustrated, showing a fill valve 180 and a passage 182 extending from fill valve 180 to chamber 174 for supplying the pressurized fluid to chambers 174 , 176 at the surface prior to running fluid sampler 100 downhole.
As best seen in FIGS. 3A and 5 , actuator 106 includes multiple valves 184 , 186 , 188 and respective multiple rupture disks 190 , 192 , 194 to provide for separate actuation of multiple groups of sampling chambers 102 . In the illustrated embodiment, nine sampling chambers 102 may be used, and these are divided up into three groups of three sampling chambers each. Each group of sampling chambers can be referred to as a sampling chamber assembly. Thus, a valve 184 , 186 , 188 and a respective rupture disk 190 , 192 , 194 are used to actuate a group of three sampling chambers 102 . For clarity, operation of actuator 106 with respect to only one of the valves 184 , 186 , 188 and its respective one of the rupture disks 190 , 192 , 194 is described below. Operation of actuator 106 with respect to the other valves and rupture disks is similar to that described below.
Valve 184 initially isolates passage 164 , which is in communication with passages 110 in three of the sampling chambers 102 via passage 196 , from internal fluid passage 112 of fluid sampler 100 . This isolates sample chamber 114 in each of the three sampling chambers 102 from passage 112 . When it is desired to receive a fluid sample into each of the sample chambers 114 of the three sampling chambers 102 , pressure in annulus 26 is increased a sufficient amount to rupture the disk 190 . This permits pressure in annulus 26 to shift valve 184 upward, thereby opening valve 184 and permitting communication between passage 112 and passages 196 , 164 .
Fluid from passage 112 then enters passage 110 in the upper portion of each of the three sampling chambers 102 . For clarity, the operation of only one of the sampling chambers 102 after receipt of a fluid sample therein is described below. The fluid flows from passage 110 through check valve 116 to sample chamber 114 . An initial volume of the fluid is trapped in debris chamber 126 of piston 118 as described above. Downward displacement of the piston section 122 , and then the combined piston sections 122 , 124 , is slowed by the metering fluid in chamber 120 flowing through restrictor 134 . This prevents pressure in the fluid sample received in sample chamber 114 from dropping below its bubble point.
As piston 118 displaces downward, the metering fluid in chamber 120 flows through restrictor 134 into chamber 138 . At this point, prong 142 maintains check valve 144 off seat. The metering fluid received in chamber 138 causes piston 146 to displace downward. Eventually, spacer 150 contacts stem 152 of valve 154 which opens valve 154 . Opening of valve 154 permits pressure in pressure source 108 to be applied to chamber 148 . Pressurization of chamber 148 also results in pressure being applied to chambers 138 , 120 and thus to sample chamber 114 . This is due to the fact that passage 156 is in communication with passages 166 , 172 (see FIG. 3C ) and, thus, is in communication with the pressurized fluid from pressure source 108 .
When the pressure from pressure source 108 is applied to chamber 138 , piston assembly 140 collapses and prong 142 no longer maintains check valve 144 off seat. Check valve 144 then prevents pressure from escaping from chamber 120 and sample chamber 114 . Check valve 116 also prevents escape of pressure from sample chamber 114 . In this manner, the fluid sample received in sample chamber 114 is pressurized.
In the illustrated embodiment of fluid sampler 100 , multiple sampling chambers 102 are actuated by rupturing disk 190 , since valve 184 is used to provide selective communication between passage 112 and passages 110 in the upper portions of multiple sampling chambers 102 . Thus, multiple sampling chambers 102 simultaneously receive fluid samples therein from passage 112 .
In a similar manner, when rupture disk 192 is ruptured, an additional group of multiple sampling chambers 102 will receive fluid samples therein, and when the rupture disk 194 is ruptured a further group of multiple sampling chambers 102 will receive fluid samples therein. Rupture disks 184 , 186 , 188 may be selected so that they are ruptured sequentially at different pressures in annulus 26 or they may be selected so that they are ruptured simultaneously, at the same pressure in annulus 26 .
Another important feature of fluid sampler 100 is that the multiple sampling chambers 102 , nine in the illustrated example, share the same pressure source 108 . That is, pressure source 108 is in communication with each of the multiple sampling chambers 102 . This feature provides enhanced convenience, speed, economy and safety in the fluid sampling operation. In addition to sharing a common pressure source downhole, the multiple sampling chambers 102 of fluid sampler 100 can also share a common pressure source on the surface. Specifically, once all the samples are obtained and pressurized downhole, fluid sampler 100 is retrieved to the surface. Even though certain cooling of the samples will take place, the common pressure source maintains the samples at a suitable pressure to prevent any phase change degradation. Once on the surface, the sample may remain in the multiple sampling chambers 102 for a considerable time during which temperature conditions may fluctuate. Accordingly, a surface pressure source, such a compressor or a pump, may be used to supercharge the sampling chambers 102 . This supercharging process allows multiple sampling chambers 102 to be further pressurized at the same time with sampling chambers 102 remaining in carrier 104 or after sampling chambers 102 have been removed from carrier 104 .
Note that, although actuator 106 is described above as being configured to permit separate actuation of three groups of sampling chambers 102 , with each group including three of the sampling chambers 102 , it will be appreciated that any number of sampling chambers 102 may be used, sampling chambers 102 may be included in any number of groups (including one), each group could include any number of sampling chambers 102 (including one), different groups can include different numbers of sampling chambers 102 and it is not necessary for sampling chambers 102 to be separately grouped at all.
Referring now to FIG. 6 , an alternate actuating method for fluid sampler 100 is representatively and schematically illustrated. Instead of using increased pressure in annulus 26 to actuate valves 184 , 186 , 188 , a control module 198 included in fluid sampler 100 may be used to actuate valves 184 , 186 , 188 . For example, a telemetry receiver 199 may be connected to control module 198 . Receiver 199 may be any type of telemetry receiver, such as a receiver capable of receiving acoustic signals, pressure pulse signals, electromagnetic signals, mechanical signals or the like. As such, any type of telemetry may be used to transmit signals to receiver 199 .
When control module 198 determines that an appropriate signal has been received by receiver 199 , control module 198 causes a selected one or more of valves 184 , 186 , 188 to open, thereby causing a plurality of fluid samples to be taken in fluid sampler 100 . Valves 184 , 186 , 188 may be configured to open in response to application or release of electrical current, fluid pressure, biasing force, temperature or the like.
Referring now to FIGS. 7 and 8 , an alternate embodiment of a fluid sampler for use in obtaining a plurality of fluid samples that embodies principles of the present invention is representatively illustrated and generally designated 200 . Fluid sampler 200 includes an upper connector 202 for coupling fluid sampler 200 to other well tools in the sampler string. Fluid sampler 200 also includes an actuator 204 that operates in a manner similar to actuator 106 described above. Below actuator 204 is a carrier 206 that is of similar construction as carrier 104 described above. Fluid sampler 200 further includes a manifold 208 for distributing fluid pressure. Below manifold 208 is a lower connector 210 for coupling fluid sampler 200 to other well tools in the sampler string.
Fluid sampler 200 has a longitudinally extending internal fluid passageway 212 formed completely through fluid sampler 200 . Passageway 212 becomes a portion of passage 16 in tubular string 12 (see FIG. 1 ) when fluid sampler 200 is interconnected in tubular string 12 . In the illustrated embodiment, carrier 206 has ten exteriorly disposed chamber receiving slots that circumscribe internal fluid passageway 212 . As mentioned above, a pressure and temperature gauge/recorder (not shown) of the type known to those skilled in the art can be received in carrier 206 within one of the chamber receiving slots such as slot 214 . The remainder of the slots are used to receive sampling chambers and pressure source chambers.
In the illustrated embodiment, sampling chambers 216 , 218 , 220 , 222 , 224 , 226 are respectively received within slots 228 , 230 , 232 , 234 , 236 , 238 . Sampling chambers 216 , 218 , 220 , 222 , 224 , 226 are of a construction and operate in the manner described above with reference to sampling chamber 102 . Pressure source chambers 240 , 242 , 244 are respectively received within slots 246 , 248 , 250 in a manner similar to that described above with reference to sampling chamber 102 . Pressure source chambers 240 , 242 , 244 initially contain a pressurized fluid, such as a compressed gas or liquid. Preferably, compressed nitrogen at between about 10,000 psi and 20,000 psi is used to precharge chambers 240 , 242 , 244 , but other fluids or combinations of fluids and/or other pressures both higher and lower could be used, if desired.
Actuator 204 includes three valves that operate in a manner similar to valves 184 , 186 , 188 of actuator 106 . Actuator 204 has three rupture disks, one associated with each valve in a manner similar to rupture disks 190 , 192 , 194 of actuator 106 and one of which is pictured and denoted as rupture disk 252 . As described above, each of the rupture disks provides for separate actuation of a group of sampling chambers. In the illustrated embodiment, six sampling chambers are used, and these are divided up into three groups of two sampling chambers each. Associated with each group of two sampling chambers is one pressure source chamber. Specifically, rupture disk 252 is associated with sampling chambers 216 , 218 which are also associated with pressure source chamber 240 via manifold 208 . In a like manner, the second rupture disk is associated with sampling chambers 220 , 222 which are also associated with pressure source chamber 242 via manifold 208 . In addition, the third rupture disk is associated with sampling chambers 224 , 226 which are also associated with pressure source chamber 244 via manifold 208 . In the illustrated embodiment, each rupture disk, valve, pair of sampling chambers, pressure source chamber and manifold section can be referred to as a sampling chamber assembly. Each of the three sampling chamber assemblies operates independently of the other two sampling chamber assemblies. For clarity, the operation of one sampling chamber assembly is described below. Operation of the other two sampling chamber assemblies is similar to that described below.
The valve associated with rupture disk 252 initially isolates the sample chambers of sampling chambers 216 , 218 from internal fluid passageway 212 of fluid sampler 200 . When it is desired to receive a fluid sample into each of the sample chambers of sampling chambers 216 , 218 , pressure in annulus 26 is increased a sufficient amount to rupture the disk 252 . This permits pressure in annulus 26 to shift the associated valve upward in a manner described above, thereby opening the valve and permitting communication between passageway 212 and the sample chambers of sampling chambers 216 , 218 .
As described above, fluid from passageway 212 enters a passage in the upper portion of each of the sampling chambers 216 , 218 and passes through an optional check valve to the sample chambers. An initial volume of the fluid is trapped in a debris chamber as described above. Downward displacement of the debris piston is slowed by the metering fluid in another chamber flowing through a restrictor. This prevents pressure in the fluid sample received in the sample chambers from dropping below its bubble point.
As the debris piston displaces downward, the metering fluid flows through the restrictor into a lower chamber causing a piston to displace downward. Eventually, a spacer contacts a stem of a lower valve which opens the valve and permits pressure from pressure source chamber 240 to be applied to the lower chamber via manifold 208 . Pressurization of the lower chamber also results in pressure being applied to the sample chambers of sampling chambers 216 , 218 .
As described above, when the pressure from pressure source chamber 240 is applied to the lower chamber, a piston assembly collapses and a prong no longer maintains a check valve off seat, which prevents pressure from escaping from the sample chambers. The upper check valve also prevents escape of pressure from the sample chamber. In this manner, the fluid samples received in the sample chambers are pressurized.
In the illustrated embodiment of fluid sampler 200 , two sampling chambers 216 , 218 are actuated by rupturing disk 252 , since the valve associated therewith is used to provide selective communication between passageway 212 the sample chambers of sampling chambers 216 , 218 . Thus, both sampling chambers 216 , 218 simultaneously receive fluid samples therein from passageway 212 .
In a similar manner, when the other rupture disks are ruptured, additional groups of two sampling chambers (sampling chambers 220 , 222 and sampling chambers 224 , 226 ) will receive fluid samples therein and the fluid samples obtained therein will be pressurize by pressure sources 242 , 244 , respectively. The rupture disks may be selected so that they are ruptured sequentially at different pressures in annulus 26 or they may be selected so that they are ruptured simultaneously, at the same pressure in annulus 26 .
One of the important features of fluid sampler 200 is that the multiple sampling chambers, two in the illustrated example, share a common pressure source. That is, each pressure source is in communication with multiple sampling chambers. This feature provides enhanced convenience, speed, economy and safety in the fluid sampling operation. In addition to sharing a common pressure source downhole, multiple sampling chambers of fluid sampler 200 can also share a common pressure source on the surface. Specifically, once all the samples are obtained and pressurized downhole, fluid sampler 200 is retrieved to the surface. Even though certain cooling of the samples will take place, the common pressure source maintains the samples at a suitable pressure to prevent any phase change degradation. Once on the surface, the samples may remain in the multiple sampling chambers for a considerable time during which temperature conditions may fluctuate. Accordingly, a surface pressure source, such a compressor or a pump, may be used to supercharge the sampling chambers. This supercharging process allows multiple sampling chambers to be further pressurized at the same time with the sampling chambers remaining in carrier 206 or after sampling chambers have been removed from carrier 206 .
It should be understood by those skilled in the art that even though fluid sampler 200 has been described as having one pressure source chamber in communication with two sampling chambers via manifold 208 , other numbers of pressure source chambers may be in communication with other numbers of sampling chambers with departing from the principles of the present invention. For example, in certain embodiments, one pressure source chamber could communicate pressure to three, four or more sampling chambers. Likewise, two or more pressure source chambers could act as a common pressure source to a single sampling chamber or to a plurality of sampling chambers. Each of these embodiments may be enabled by making the appropriate adjustments to manifold 208 such that the desired pressure source chambers and the desired sampling chambers are properly communicated to one another.
Referring now to FIGS. 9A-9G and with reference to FIGS. 3A-3E , an alternate fluid sampling chamber for use in a fluid sampler including an exemplary carrier having a pressure source coupled thereto for use in obtaining a plurality of fluid samples that embodies principles of the present invention is representatively illustrated and generally designated 300 . Each of the sampling chambers 300 is coupled to a carrier 104 that also includes an actuator 106 and a pressure source 108 as depicted in FIG. 3 .
As described more fully below, a passage 310 in an upper portion of sampling chamber 300 (see FIG. 9A ) is placed in communication with a longitudinally extending internal fluid passageway 112 formed completely through the fluid sampler (see FIG. 3 ) when the fluid sampling operation is initiated using actuator 106 . Passage 112 becomes a portion of passage 16 in tubular string 12 (see FIG. 1 ) when the fluid sampler is interconnected in tubular string 12 . As such, internal fluid passageway 112 provides a smooth bore through the fluid sampler. Passage 310 in the upper portion of sampling chamber 300 is in communication with a sample chamber 314 via a check valve 316 . Check valve 316 permits fluid to flow from passage 310 into sample chamber 314 , but prevents fluid from escaping from sample chamber 314 to passage 310 .
A debris trap piston 318 is disposed within housing 302 and separates sample chamber 314 from a meter fluid chamber 320 . When a fluid sample is received in sample chamber 314 , debris trap piston 318 is displaced downwardly relative to housing 302 to expand sample chamber 314 . Prior to such downward displacement of debris trap piston 318 , however, fluid flows through sample chamber 314 and passageway 322 of piston 318 into debris chamber 326 of debris trap piston 318 . The fluid received in debris chamber 326 is prevented from escaping back into sample chamber 314 due to the relative cross sectional areas of passageway 322 and debris chamber 326 as well as the pressure maintained on debris chamber 326 from sample chamber 314 via passageway 322 . An optional check valve (not pictured) may be disposed within passageway 322 if desired. Such a check valve would operate in the manner described above with reference to check valve 128 in FIG. 2B . In this manner, the fluid initially received into sample chamber 314 is trapped in debris chamber 326 . Debris chamber 326 thus permits this initially received fluid to be isolated from the fluid sample later received in sample chamber 314 . Debris trap piston 318 includes a magnetic locator 324 used as a reference to determine the level of displacement of debris trap piston 318 and thus the volume within sample chamber 314 after a sample has been obtained.
Meter fluid chamber 320 initially contains a metering fluid, such as a hydraulic fluid, silicone oil or the like. A flow restrictor 334 and a check valve 336 control flow between chamber 320 and an atmospheric chamber 338 that initially contains a gas at a relatively low pressure such as air at atmospheric pressure. A collapsible piston assembly 340 includes a prong 342 which initially maintains check valve 344 off seat, so that flow in both directions is permitted through check valve 344 between chambers 320 , 338 . When elevated pressure is applied to chamber 338 , however, as described more fully below, piston assembly 340 collapses axially, and prong 342 will no longer maintain check valve 344 off seat, thereby preventing flow from chamber 320 to chamber 338 .
A piston 346 disposed within housing 302 separates chamber 338 from a longitudinally extending atmospheric chamber 348 that initially contains a gas at a relatively low pressure such as air at atmospheric pressure. Piston 346 includes a magnetic locator 347 used as a reference to determine the level of displacement of piston 346 and thus the volume within chamber 338 after a sample has been obtained. Piston 346 included a piercing assembly 350 at its lower end. In the illustrated embodiment, piercing assembly 350 is threadably coupled to piston 346 which creates a compression connection between a piercing assembly body 352 and a needle 354 . Alternatively, needle 354 may be coupled to piercing assembly body 352 via threading, welding, friction or other suitable technique. Needle 354 has a sharp point at its lower end and may have a smooth outer surface or may have an outer surface that is fluted, channeled, knurled or otherwise irregular. As discussed more fully below, needle 354 is used to actuate the pressure delivery subsystem of the fluid sampler when piston 346 is sufficiently displaced relative to housing 302 .
Below atmospheric chamber 348 and disposed within the longitudinal passageway of housing 302 is a valving assembly 356 . Valving assembly 356 includes a pressure disk holder 358 that receives a pressure disk therein that is depicted as rupture disk 360 , however, other types of pressure disks that provide a seal, such as a metal-to-metal seal, with pressure disk holder 358 could also be used including a pressure membrane or other piercable member. Rupture disk 360 is held within pressure disk holder 358 by hold down ring 362 and gland 364 that is threadably coupled to pressure disk holder 358 . Valving assembly 356 also includes a check valve 366 . Valving assembly 356 initially prevents communication between chamber 348 and a passage 380 in a lower portion of sampling chamber 300 . After actuation the pressure delivery subsystem by needle 354 , check valve 366 permits fluid flow from passage 380 to chamber 348 , but prevents fluid flow from chamber 348 to passage 380 .
As mentioned above, one or more of the sampling chambers 300 and preferably nine of sampling chambers 300 are installed within exteriorly disposed chamber receiving slots 159 that circumscribe internal fluid passageway 112 of carrier 104 . A seal bore 160 (see FIG. 3B ) is provided in carrier 104 for receiving the upper portion of sampling chamber 300 and another seal bore 162 (see FIG. 3C ) is provided for receiving the lower portion of sampling chamber 300 . In this manner, passage 310 in the upper portion of sampling chamber 300 is placed in sealed communication with a passage 164 in carrier 104 , and passage 380 in the lower portion of sampling chamber 300 is placed in sealed communication with a passage 166 in carrier 104 .
As described above, once the fluid sampler is in its operable configuration and is located at the desired position within the wellbore, a fluid sample can be obtained into one or more of the sample chambers 314 by operating actuator 106 . Fluid from passage 112 then enters passage 310 in the upper portion of each of the desired sampling chambers 300 . For clarity, the operation of only one of the sampling chambers 300 after receipt of a fluid sample therein is described below. The fluid flows from passage 310 through check valve 316 to sample chamber 314 . It is noted that check valve 316 may include a restrictor pin 368 to prevent excessive travel of ball member 370 and over compression or recoil of spiral wound compression spring 372 . An initial volume of the fluid is trapped in debris chamber 326 of piston 318 as described above. Downward displacement of piston 318 is slowed by the metering fluid in chamber 320 flowing through restrictor 334 . This prevents pressure in the fluid sample received in sample chamber 314 from dropping below its bubble point.
As piston 318 displaces downward, the metering fluid in chamber 320 flows through restrictor 334 into chamber 338 . At this point, prong 342 maintains check valve 344 off seat. The metering fluid received in chamber 338 causes piston 346 to displace downwardly. Eventually, needle 354 pierces rupture disk 360 which actuates valving assembly 356 . Actuation of valving assembly 356 permits pressure from pressure source 108 to be applied to chamber 348 . Specifically, once rupture disk 360 is pierced, the pressure from pressure source 108 passes through valving assembly 356 including moving check valve 366 off seat. In the illustrated embodiment, a restrictor pin 374 prevents excessive travel of check valve 366 and over compression or recoil of spiral wound compression spring 376 . Pressurization of chamber 348 also results in pressure being applied to chambers 338 , 320 and thus to sample chamber 314 .
When the pressure from pressure source 108 is applied to chamber 338 , pins 378 are sheared allowing piston assembly 340 to collapse such that prong 342 no longer maintains check valve 344 off seat. Check valve 344 then prevents pressure from escaping from chamber 320 and sample chamber 314 . Check valve 316 also prevents escape of pressure from sample chamber 314 . In this manner, the fluid sample received in sample chamber 314 is pressurized.
While this invention has been described with a reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
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An apparatus for actuating a pressure delivery system of a fluid sampler. The apparatus includes a housing ( 302 ) having a longitudinal passageway and defining first and second chambers ( 338, 348 ). A piston ( 346 ) is disposed within the longitudinal passageway between the first and second chambers ( 338, 348 ). A valving assembly ( 356 ) is disposed within the longitudinal passageway. The valving assembly ( 356 ) is operable to selectively prevent communication of pressure from a pressure source of the fluid sampler to the second chamber ( 348 ). The valving assembly ( 356 ) is actuated responsive to an increase in pressure in the first chamber ( 338 ) which longitudinally displaces the piston ( 346 ) toward the valving assembly ( 356 ) until at least a portion of the piston ( 346 ) contacts the valving assembly ( 356 ), thereby releasing pressure from the pressure source into the second chamber ( 348 ) and longitudinally displacing the piston ( 346 ) away from the valving assembly ( 356 ).
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This is a continuation of application Ser. No. 304,525, filed Nov. 7, 1972 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to digital-to-synchro conversion units for converting the digital input data from a DME (Distance Measuring Equipment) to synchro output voltages, and more particularly, it relates to digital-to-synchro converters of the type for providing continuous-real-time indications in angular form representing distance.
2. Description of Prior Art
With the advent and extensive use of digital circuits to implement systems that heretofore were primarily of the analogue type, a need has grown to provide digital-to-analogue converters. The indicators of the older type analogue equipment were obviously of the analogue type. In many aircraft installations, one need only replace both the analogue equipment and its associated indicator with modern digital equipment. There are cases, however, when this is not possible. The analogue indicator, for instance, may be part of a "flight director," an apparatus usually associated with an automatic aircraft controller that displays both the aircraft attitude and the outputs of the navigation instruments. The distance indicator for the flight director is usually an analogue unit that employs three synchro receivers. When a digital DME is used, the flight director is so expensive that it is cheaper to use a digital-to-analogue converter rather than remove and redesign its DME indicator.
Although the D/A conversion art is quite advanced satisfying the requirements of the avionics industry for units that are both accurate and inexpensive, there still remains difficult problems. Conventional units are large, expensive, and are complex. One solution, described in U.S. Pat. No. 3,662,379, uses tapped transformers and relays. Several transformers and relays are required for only one digit, noting that synchro indicators usually require three digits.
Another solution, described in the periodical "Electronics," Oct. 26, 1970, page 95, requires a conversion of the digital information-to-resolver signal as illustrated in FIG. 4 thereof. Resolver signals, however, are not compatible with synchros, and therefore, additional converter steps are required in order to develop the synchro signals. Known digital-to-synchro units require an input that is angle binary.. "Angle binary" relates angles by multiples of two. Thus, a rotation of 180° is followed by 90°, 45° steps in rotation for the most significant bit (MSB). The most significant bit (MSB) of such codes requires digital-to-digital converters at the input and a power type synchro device at the output. Also angle binary codes are not compatible with a conventional DME distance indicator since rotations are required in steps of either 36° or 3.6°. One must select, therefore, from the angle binary code those bits that provide the proper rotation. Such digital-to-digital converters would result in complex circuits. There is a need, therefore, for a digital-to-synchro converter that overcomes the problems of the known converters discussed above.
SUMMARY OF THE INVENTION
According to the present invention a digital-to-synchro converter is arranged to receive input data in the form of digital signals representing distance, the digital signals comprising at least two sets of signals each representing two adjacent figures of a decimal representation of the distance preferably the two lowest significant figures thereof. Means are provided, if necessary, for converting and, if desired, storing the received digital signals. A reference signal, suitably a sinusoidal voltage, is used to control, gate, and initiate the several component circuits for processing the digital data. A means is provided for releasing the stored signals in response to the reference signal, the stored signals being delayed and subsequently released after a variable and fixed delay. Two output signals are generated having a predetermined phase relationship whose amplitudes represent the respective distance values of said two figures. The two output signals are multiplied by a reference signal to generate a control signal for operating a synchro receiver having a rotor whose angular displacement is proportional to the linear position represented by the two adjacent figures representative of the distance data.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a simplified schematic of a digital-to-synchro converter.
FIG. 2 is a block diagram of a digital-to-synchro converter according to the present invention.
FIG. 3 is a timing diagram showing the several signals and pulses that are developed during the operation of the converter of the invention.
FIG. 4 is a block diagram illustrating a means for converting serial input data into parallel form.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The converter of the invention is arranged to convert digital format signals, such as a binary coded decimal (BCD) either in parallel or serial form, or signals in the form of a pulse train at a rate suitable for conversion to distance measurements manifested for synchro receiver signals for driving a three-wire synchro receiver to display, for example, distance represented by the digital signals. One form of the invention utilizes solid-state electronic components for portions of the digital-to-synchro converter. The converter transforms or converts the signals into a form compatible with three-wire synchro receiver stator windings and the associated rotor windings for use in driving mechanical displays or indicators. by suitable electronic circuits, the distance data provided in any chosen one of the digital formats, as provided by suitable distance measuring equipment, is converted to an equivalent range display on a synchro type indicator.
An example of such suitable equipment is the AVQ-85 DME, a type of distance measuring equipment manufactured by the RCA Corporation. The AVQ-85 DME provides a digital seven-segment range display. However, a standard flight director which displays both the attitude and orientation of the aircraft as well as the outputs of the navigation instruments, usually has a distance display which accepts only distance data with a synchro type format. A digital-to-synchro type converter is, therefore, required in order for the new digital DME equipment to drive such a flight director.
The present embodiment will illustrate the use of the invention with parallel BCD digital data. It will be understood, however, to those skilled in the art, that the use of a suitable digital converter at the input will allow for the receipt of other types of digital formats such as serial binary or other types of pulse trains as will be discussed in consideration of FIG. 4.
A conventional three-synchro distance read-out is used to provide the distance indications in nautical miles, including tenths of a mile. Preliminary to a detailed description of the present embodiment of the invention, reference is made to FIG. 1 wherein a digital-to-synchro transmitter is coupled to a single synchro receiver. FIG. 1, it should be understood, represents any system that serves to utilize digital data to operate a synchro. A description of such a system will provide a basis for a better understanding of the present invention. A digital-to-analogue converter 10 receives digital input position command signals over path 12. The D/A converter 10 provides synchro signals over path 14 and 16 to windings 18 (X-0) and 20 (Y-0) of the synchro stator windings of a synchro receiver 22. The rotor windings 24 of the synchro receiver 22 are energized by a reference voltage, suitably 400 Hz, at 26 volts, over path 26. The reference voltage is also provided as an input to the D/A converter 10 over path 28. The third winding, 30 (Z-0) of the synchro receiver 22, is grounded at 22 common with one end of the rotor 24. The stator windings 18, 20, and 30 are mounted so as to be spacially separated 120° apart as schematically shown in FIG. 1, the rotor 24 rotating with respect to the fixed stator windings in a manner well known in the art. When the rotor position relative to the stator windings is parallel with any one of the respective windings of the stator, for example, when the rotor is vertical, that is, 0°, a maximum voltage will be induced in the stator winding 30 (Z-0). Similarly, when the rotor assumes a position of +60°, being thereby parallel with the stator winding 18 (X-0), a maximum voltage will be induced in winding 18. Also, when the rotor 24 is in a position 180° from those just described, a maximum voltage of the opposite polarity will be induced in the stator windings. The rotor coil 24 and the stator winding 30 (Z-0) are connected together and to ground as shown. The amplitude factors for θ° of rotation may be represented by:
V.sub.xz =-√2 (11.8) sin (θ + 60°) (1)
V.sub.yz =-√2 (11.8) sin (θ + 120°) (2)
Equations (1) and (2) represent the amplitude of the 400 Hz stator excitation signals, across the stator windings, 18 and 30, in series, and 20 and 30, in series, respectively.
In operation, the application of the reference voltage over path 26 and the simultaneous application of the digital input signal over path 12 causes the rotor 24 to assume the position corresponding to the digital distance of the data. Thus, an indicator of the angular position of the rotor 24 is coupled to a wheel onto which the desired numbers (0, 1, 2, etc.) are stamped in a manner corresponding to the digital data and calibrated to a read-out scale in distance. In order to increase the resolution or accuracy of the digital data, the indicator is formed of three rotors (24), each corresponding to a different digital position of the numeric representation of the distance. Thus, for a distance measuring system providing distance data to a maximum of 299.9 nautical miles, a first rotor provides distances of 0 to 200 nautical miles (N.M.) in 100 N.M. steps. A second synchro provides read-outs between 0 and 90 N.M. in 10 N.M. steps, and a third synchro provides an indication between 0 and 9.9 N.M. in 0.1 N.M. steps.
The arrangement and organization of the present invention is illustrated by the embodiment illustrated in FIG. 2. In general, the invention provides for the receipt of incoming digital formated signals preferably in parallel form representing the distance determined by suitable apparatus of conventional form not shown or described further. The present description contemplates the digital formated signals in such form as to have each of the digits representing the distance received simultaneously, or as is known in the art, parallel format. Suitable converters are contemplated wherein such signals are received thus in serial or parallel form.
The incoming signals are stored in such an arrangement that the outputs of the storage elements comprise four groups of four wire binary coded decimal (BCD) numbers. Each group of the four, except the third and fourth group, represent one of the three digits of a three digit distance indication of conventional decimal number form, and as such each group represents the angular rotation that the synchro should be rotated. The third and fourth groups of the digital formated signals are combined and processed in integrated circuits to position a third synchro, whose rotation is proportional to the two integers representing the third digit and fractional figures. The capacity of one form of a synchro arrangement is 299.9 nautical miles.
The first digit of the four significant digits of the range in digital format represents the most significant hundred's place digit of the distance data. For the embodiment to be described, this digit would thus be manifested by 0, 1, or 2, for indications of 000.0 to 299.9 nautical miles (N.M.). The manner in which the conversion of BCD data is converted to synchro form for such numerical values is well known in the art and will not be described in any detail. See, for example, U.S. Pat. No. 3,553,647 issued to Bullock on Jan. 5, 1971, particularly FIG. 12 thereof describing the use of transmission gates or switches to generate such appropriate synchro control voltages.
The other two significant digits, namely, the digits representing the ten's and the unit's place and fractional portions (tenth's) thereof, each respectively, control a variable digital delay circuit that is arranged to be proportional to the magnitude of that digit. The digital delay circuit is preferably referred to a 400 Hz signal and is also triggered into operation by that 400 Hz signal, such signal sources being of the type usually used in conventional aircraft systems. The variable delay that is provided for the incoming pulse representative of the digital formated signals in turn is utilized to initiate a fixed delay generator having two outputs each delayed respectively 60° and 120°. The delays of 60° and 120° correspond to the required inputs to a three phase synchro as explained above whereby the resolved output manifested by the rotation of the rotor of the synchro receiver assumes a position corresponding to the amplitude of the two outputs of the fixed delay generator. The wave form of the reference signal [FIG. 3 (a)], to be described, is sampled at the end of all of the delays, that is, at the end of both the variable and the fixed delay. The output of the sampler is the two DC voltages. These two voltages are propotional to:
sin (36N + 60) (3)
sin (3.6M + 120) (4)
where N equals the ten's place of the BCD distance number and M is a function of the 1.0 and 0.1 of the BCD distance number in combined form, that is, the two least significant figures. Thus, more generally, the unit's and tenth's place of the BCD numbers are P and Q respectively, whereby M = 1QP + Q.
The two DC output voltages whose respective amplitudes are proportional to the functions represented by equations 3 and 4 above are utilized as one input of a two input analogue multiplier. The reference signal (FIG. 3a) is applied to the other input of the analogue multiplier. The multiplier output is, therefore, equal to:
X = - √2 (11.8) sin [(36N + 60)] sin ω.sub.R t (5)
Y = - √2 (11.8) sin [(3.6M + 120)] sin ω.sub.R t (6)
where sin ω R t represents the reference signal (FIG. 3a) such as the 400 Hz signal. The wave forms on paths 14 and 16 of FIG. 1 are represented by signals represented by equations (5) and (6). It is to be noted that 36 N and 3.6 M represents, respectively, the desired amount of synchro rotation in degrees corresponding to the ten's place and the unit's place (including the decimal portions of the unit figure).
In FIG. 2, the two primary inputs are the 400 Hz reference voltage 100 (FIG. 3a) over path 102 and the parallel BCD distance data over paths 104, 106, 108, and 110. The reference signal 100 (400 Hz at 26 volts) is obtained from a 115 volt, 400 Hz source through a transformer 112, while the parallel BCD distance data may be derived suitably from a digital converter, not shown. The reference signal 100 is amplified by a square wave amplifier 114 to form a reference square wave 116 (FIG. 3b) that is applied to a phase locked loop 118 and to two variable digital delay circuits 120 and 122 through path 128. A suitable circuit serving as either of the detector delay circuits 120 and 122 is a down counter such as the MC4016 ripple-down counter available from the Motorola Semiconductor Products, Inc. An illustrative use of such a counter responding to BCD inputs is described in Motorola Application Note AN-532A. The phase locked loop 118 uses well known techniques to develop a 120 kHz clock over path 124 that is phase locked to the 400 Hz reference signal 100. The 120 kHz clock signal over path 124 provides the basic interval for determining all delays. Each delay is therefore referenced to the 400 Hz signal through the phase locked loop 118.
The variable delay unit 120 receives the tenth's place range data over path 104, and the unit's place range data over path 106. A 40 kHz clock signal is received over path 125 from a divide-by-three circuit 126. The divide-by-three circuit 126 receives its input from the phase locked loop 118 whose output is the 120 kHz clock signal. Delay unit 120 also receives the square wave reference pulse 116 over path 128. The delay voltage from the variable delay unit 120 is started by the falling edge of the square wave 116. The 40 kHz clock signal over path 125 is used as the delay measuring interval, while the unit's range data over path 106 and the tenth data over path 104 determine the amount of the delay. Each tenth of the distance data represents one clock pulse of delay which is equivalent to 3.6° of angular rotation. Each unit of distance data represents ten clock pulses of delay corresponding to 36° of rotation. The output of the variable delay 120 is applied to a fixed delay circuit 130 over path 132. After the delay has been introduced by the delay circuit 120, the fixed delay circuit 130 is then energized after being gated by the 120 kHz clock pulse over path 124. The outputs of the fixed delay 130 are signals over path 134 and 136 that represents additional delays of 60° and 120°.
The fixed digital delay module 130 receiving the 120 kHz input from divider circuit (phase locked loop) 118 over path 124 provides two signals 134a and 136a (FIG. 3d), 180° out of phase with each other. The falling edge of one of the two signals (134a) is delayed 60° following the variable delay pulse over path 132, the other signal being determined by the falling edge of the other signal 136a which is delayed 120° over path 136, the falling edges of each of the two signals 134a and 136a triggering a sampling generator 138. The sampling generator 138 is also provided with a filtered 400 Hz signal over path 139 which signal is filtered to avoid possible jitter by a suitable filter 142. It is this filtered 400 Hz signal over path 140 which is utilized for sampling purposes according to the invention.
The output of the sampling generator 138 is a pair of DC signals fed over paths 140 and 142 that are respectively applied to analogue multipliers 144 and 146. The multipliers each receive the 400 Hz reference signal over path 148 which has been suitably attenuated by an attenuator 150 from the signal reference bus 113 for the 400 Hz signal. The true products of the multipliers are applied over paths 152 and 154 to power amplifiers 156 and 158 whose outputs respectively drive the stators of the synchro receivers 160. The voltage for the synchro rotor (not shown) is suitably derived from transformer 112.
The operation of the ten's place of the input distance data is similar to that for the unit's place just described. The inputs of the ten's digit variable delay 122 are the ten's BCD distance data over path 108. The reference square wave 116 is applied to delay 122, as well as the output of clock source 135 at a rate of 4 kHz. The 4 kHz clock rate is required since the ten's digit advances in ten nautical mile steps. Each step represents one tenth of a rotation of the rotor, or 36°, whereas the unit's synchro must resolve one hundredths of a rotation (3.6°) which requires a 40 kHz clock. The ten's place clock, therefore, need only be 4 kHz. Specifically, one period of the 4 kHz clock represents one tenth of the 400 Hz clock period or 36°.
The ten's place variable digit delay circuit 122 introduces a delay of 36N° where N is the value of the ten's BCD data applied over path 108. Thus, for example, a range of 146.2 nautical miles includes a value of 4 for N (the ten's BCD number), 6 for the unit's BCD number 4, and two for the tenth BCD number 3. In general, the output of the ten's variable delay 122 is a pulse 166a (FIG. 3 (e)) fed over path 162 which initiates the ten's place fixed delay module 164. Delay circuit 164 also is provided with the 120 kHz clock signal over path 124 from the output of the phase locked loop 118. The output of the fixed delay 164 is two pulses whose falling edges are respectively delayed 60° and 120° over paths 166 and 168, relative to the phase of the variable delay pulse 166. See Figures e and f wherein these two pulses (180° out-of-phase) are represented in the timing diagram as pulses 170 and 172 compared to pulse 166.
The fixed delay output pulses 170 and 172 initiate the sampling generator, suitably a sample and hold circuit, 174 which is also provided with the filtered 400 Hz reference signal over path 139 which is coupled, as previously explained, over bus 113 through the filter 142. Specifically, a falling edge of a pulse on either path 166 or 168 will cause the voltage on path 139 to be sampled, resulting in a DC voltage being developed on paths 176 and 178. Each of these DC voltages is applied to an analogue multiplier 180 and 182, respectively. These multipliers are also provided with the reference 400 Hz signal over path 148 after attenuation by the attenuator 150, as previously explained. The output of the multipliers 180 and 182 are fed over paths 184 and 186 to power amplifiers 188 and 190 which in turn energize the ten's synchro 192 over paths 194 and 196, respectively. The rotor of this synchro, as well as the others, as has been described, is energized from transformer 112.
The operation of the hundred's place nautical mile digit circuit of BCD data received over 110 is somewhat different. Only three positions are required for one form of the invention wherein the range capacity of operation is 299.9 nautical miles. Therefore, only three discrete positions are required. The most significant position is 0 for distances less than 100 nautical miles, 1 for 100 to 199.9 nautical miles, and 2 for 200 to 299.9 nautical miles.
Discrete steps, effected by solid state FET devices, in the hundredth's place of nautical miles are generated by a suitable X-Y signal generator 198 which modulates the 400 Hz sine wave 100, on path 113 based on the BCD data for the hundredth's figure received over path 110. A circuit serving as a suitable generator 198 is illustrated, for example, in the above-mentioned U.S. Pat. No. 3,553,647. This data as previously described is representative of the hundredth's distance 0, 1, or 2. The modulated output of the signal generator 198 provides the synchro control signals of paths 200 and 202 to power amplifiers 204 and 206 to develop the hundred nautical mile synchro stator voltages for energizing the synchro receiver 208, the rotor of which is energized in the manner previously described. The converted output of 146.2 nautical miles is shown indicated in the indicator 210. The tenths of a nautical mile (i.e., 0.2) is indicated by a subdivision of the units wheel 212 as shown by reference numeral 214. The rotor effecting rotation of the digit wheel 212 advances incrementally in tenths of a nautical mile depending upon rotation of the rotor in response to signals applied to the synchro receiver 160.
The present invention may be used in systems utilizing either parallel or serial formated signals. FIG. 4 illustrates an arrangement for converting serial formated signals into parallel form. A series-to-parallel converter 220 receives input data in serial format over path 222 and converts such data into parallel form generating signals corresponding to the BCD tenth's, unit's, ten's and hundredth's over paths 104, 106, 108, and 110 respectively. These signals may be applied to the converter illustrated in FIG. 2 at the conductor paths for receiving the input BCD distance data.
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A digital-to-synchro converter accepts digital distance data comprising either a binary coded decimal (BCD) signal or a train of pulses of any desired format. The converter comprises a digital-to-synchro converter whose output represents the distance data that controls a signal generator synchronized to a sinusoidal reference voltage. The signal generator output are pulses representing sample and hold control signals which are applied to a sample and hold circuit. The sine wave is sampled by the sample and hold circuit, and the output is a DC voltage that is proportional to the sine of the desirable synchro rotation angle. This voltage is applied to an analog multiplier for generating the controlling signals which are then amplified before being routed to provide distance measurements at the synchro receiver.
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FIELD OF THE INVENTION
This present invention generally relates to an automatic control system for a ripper used on construction equipment, and more specifically to automatically controlling ripper depth.
BACKGROUND OF THE INVENTION
Typically a ripper mounted on construction equipment such as a tractor is manually controlled by the operator who raises or lowers the ripper shank or varies the ripper pitch based upon experience, ground conditions, vehicle speed and other working conditions. Ripper depth is typically adjusted by removing a pin from the ripper shank and repositioning the shank relative to the ripper carrier and reinserting the pin. This effectively changes the length and potential depth of the ripper. This naturally requires operator time to reposition the ripper using the pin, and requires considerable skill and experience on the part of the operator to determine the desired depth to minimize the changes that need to be made to ripper length.
SUMMARY
A system is disclosed that limits the depth of a ripper mounted to a tractor by electronically sensing the lift cylinder length and limiting that length in order to limit the depth of ripper engagement with the ground.
A ripper depth limit system is disclosed for a ripper that includes a ripper lift cylinder. The ripper depth limit system includes an operator lift input, an operator ripper depth limit input, a lift cylinder sensor coupled to the ripper lift cylinder and a ripper electro-hydraulic controller. The operator lift input generates an operator lift signal that controls the raising and lowering of the ripper. The operator ripper depth limit input sets a ripper depth limit. The lift cylinder sensor senses the position of the ripper lift cylinder and generates a lift cylinder position signal. The ripper electro-hydraulic controller processes the operator lift signal, the lift cylinder position signal and the ripper depth limit; and generates and outputs ripper lift cylinder commands that do not allow the ripper depth to exceed the ripper depth limit. The ripper electro-hydraulic controller can include a position processor for determining a ripper position based on the lift cylinder position signal, where the position processor provides the ripper position for further processing by the ripper electro-hydraulic controller.
The operator ripper depth limit input can include an activation control for activating the ripper depth limit function, and a depth setting for setting the ripper depth limit. The operator ripper depth limit input can include a selector for selecting the ripper depth limit from a plurality of predefined depth limits. Alternatively, the operator ripper depth limit input can include a selector for selecting the ripper depth limit between a minimum ripper depth and a maximum ripper depth.
The ripper lift cylinder commands can be output to a ripper lift spool valve controlling the raising and lowering of the ripper. The ripper lift cylinder commands can be output to an output conditioning processor, and the output conditioning processor can output the conditioned ripper lift cylinder commands to a ripper lift spool valve controlling the raising and lowering of the ripper.
The ripper depth limit system can also include an operator pitch input, and a pitch cylinder sensor coupled to a ripper pitch cylinder, where he operator pitch input generates an operator pitch signal for controlling the pitch of the ripper; and the pitch cylinder sensor senses the position of the ripper pitch cylinder and generates a pitch cylinder position signal. The ripper electro-hydraulic controller can also process the operator pitch signal and the pitch cylinder position signal to generate and output ripper pitch cylinder commands that do not allow the ripper depth to exceed the ripper depth limit. The ripper pitch cylinder commands can be output to a ripper pitch spool valve controlling the pitch of the ripper. The ripper pitch cylinder commands can be output to an output conditioning processor that outputs conditioned ripper pitch cylinder commands to a ripper pitch spool valve controlling the pitch of the ripper. The ripper electro-hydraulic controller can include a position processor for determining a ripper position based on the lift and pitch cylinder position signals.
A ripper depth limit method is disclosed for controlling a ripper coupled to a lift cylinder that raises and lowers the ripper. The ripper depth limit method includes setting a ripper depth limit, reading a lift cylinder position from a sensor coupled to the lift cylinder, determining a ripper position using the lift cylinder position reading, receiving a ripper lift cylinder command from an operator control device, and determining whether executing the ripper lift cylinder command will cause the ripper to exceed the ripper depth limit. When the ripper lift cylinder command will not cause the ripper to exceed the ripper depth limit, the method includes executing the ripper lift cylinder command. When the ripper lift cylinder command will cause the ripper to exceed the ripper depth limit, the method includes revising the ripper lift cylinder command to not cause the ripper to exceed the ripper depth limit and executing the revised ripper lift cylinder command. The method then includes returning to receive another ripper lift cylinder command.
After the determining a ripper position step and before the receiving a ripper lift command step, the ripper depth limit method can include determining whether the ripper position exceeds the ripper depth limit; and when it exceeds the ripper depth limit, generating a ripper lift command to raise the ripper to the ripper depth limit. After the receiving a ripper lift cylinder command step, the ripper depth limit method can include determining whether the ripper depth limit functionality is still activated; and when it is not still activated, executing the ripper lift cylinder command and exiting the ripper depth limit method.
Setting a ripper depth limit can include reading one of a plurality of predefined depth limit values from a depth limit selector. Alternatively, setting a ripper depth limit can include determining a position of a selector between a minimum and maximum value, and determining the ripper depth limit based on the position of the selector.
A ripper depth limit method is disclosed for controlling a ripper coupled to a lift cylinder that raises and lowers the ripper and a pitch cylinder the controls the pitch of the ripper. The ripper depth limit method includes setting a ripper depth limit, reading a lift cylinder position from a lift sensor coupled to the lift cylinder, reading a pitch cylinder position from a pitch sensor coupled to the pitch cylinder, determining a ripper position using the lift and pitch cylinder position readings, receiving a ripper lift or pitch cylinder command from an operator control device, and determining whether executing the ripper lift or pitch cylinder command will cause the ripper to exceed the ripper depth limit. When the ripper lift or pitch cylinder command will not cause the ripper to exceed the ripper depth limit, the method includes executing the ripper lift or pitch cylinder command. When the ripper lift or pitch cylinder command will cause the ripper to exceed the ripper depth limit, the method includes revising the ripper lift or pitch cylinder command to not cause the ripper to exceed the ripper depth limit and executing the revised ripper lift or pitch cylinder command. The method then includes returning to receive another ripper lift or pitch cylinder command.
After the determining a ripper position step and before the receiving a ripper lift or pitch cylinder command step, the ripper depth limit method can include determining whether the ripper position exceeds the ripper depth limit, and when it exceeds the ripper depth limit, generating a ripper lift command to raise the ripper to the ripper depth limit. After the receiving a ripper lift or pitch cylinder command step, the ripper depth limit method can include determining whether the ripper depth limit functionality is still activated, and when it is not still activated, executing the ripper lift or pitch cylinder command and exiting the ripper depth limit method.
The step of revising the ripper lift or pitch cylinder command to not cause the ripper to exceed the ripper depth limit can include: for a ripper lift cylinder command, revising the ripper lift cylinder command to lower the ripper to the ripper depth limit only; and for a ripper pitch cylinder command, generating and executing a ripper lift cylinder command to raise the ripper and executing the ripper pitch cylinder command so the ripper does not exceed the ripper depth limit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary embodiment of a ripper coupled to a crawler;
FIG. 2 illustrates an exemplary electro-hydraulic (EH) system for controlling a ripper;
FIG. 3 illustrates a more detailed view of an exemplary embodiment of the EH controller that can be used in the EH system of FIG. 2 ;
FIG. 4 is a flow diagram of an exemplary control process for a ripper depth limit system that uses sensor readings from the ripper lift cylinder(s); and
FIG. 5 is a flow diagram of an exemplary control process for a ripper depth limit system that uses sensor readings from the ripper lift and pitch cylinders.
DETAILED DESCRIPTION
For the purposes of promoting an understanding of the principles of the novel invention, reference will now be made to the embodiments described herein and illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the novel invention is thereby intended, such alterations and further modifications in the illustrated devices and methods, and such further applications of the principles of the novel invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the novel invention relates.
A system is disclosed that limits the depth of a ripper attached to a crawler by electronically sensing the lift cylinder length and limiting that length in order to limit the depth of ripper engagement with the ground. The system can include electro-hydraulic (EH) valves, a microprocessor, an operator input device, and a sensor for sensing the length of at least one of the ripper carrier lift cylinders. When the operator commands a ripper lower function, a limiting function can be used to limit the minimum length of the ripper cylinder to either a predefined or custom defined length which effectively limits the ripper engagement depth.
FIG. 1 illustrates an exemplary embodiment of a ripper 110 coupled to a crawler 100 . The ripper 110 includes a shank holder 112 , a ripper shank 114 with a tip 116 , a pair of ripper pitch cylinders 120 , a pair of ripper lift cylinders 130 and a pair of links 140 . The proximal ends of the ripper pitch cylinders 120 , the ripper lift cylinders 130 and the links 140 are coupled to the crawler 100 and the distal ends of the ripper pitch cylinders 120 , the ripper lift cylinders 130 and the links 140 are coupled to the shank holder 112 . The ripper lift cylinders 130 can be extended and retracted to raise and lower the ripper 114 . The pair of ripper pitch cylinders 120 can be extended and retracted to change the pitch of the ripper 114 . The ripper shank 114 can be manually raised or lowered in the shank holder 112 .
FIG. 2 illustrates an exemplary electro-hydraulic (EH) system 200 for controlling a ripper. The EH system 200 includes a ripper EH controller 202 , a lift spool valve 250 , a pitch spool valve 260 , a pair of lift cylinders 210 , 220 , a pair of pitch cylinders 230 , 240 , a flow source P and a sink. The ripper EH controller 202 receives operator and system inputs and generates output signals to control the spool valves and cylinders.
The ripper EH controller 202 receives operator inputs from a ripper lift controller 204 , a ripper pitch controller 206 and a ripper depth limit controller 208 . The ripper lift and pitch controllers 204 , 206 can be any of various types of controllers known in the art, for example a single joystick for both lift and pitch control, or separate joysticks for each of lift and pitch control. The ripper depth limit controller 208 can also be of various types of controllers, for example a switch, knob, button, menu, etc. The ripper EH controller 202 processes the operator inputs to control the ripper.
At least one of the ripper lift cylinders 210 , 220 has a lift cylinder position sensor 214 . The lift cylinder position sensor 214 senses the position of the piston 212 in the lift cylinder 210 and sends a sensor output to the ripper EH controller 202 . The ripper EH controller 202 can use the output of the lift cylinder position sensor 214 to determine the position of the ripper relative to the main geometry of the tractor.
One of the ripper pitch cylinders 230 , 240 can have a pitch cylinder position sensor 234 . The pitch cylinder position sensor 234 senses the position of the piston 232 in the pitch cylinder 230 and sends a sensor output to the ripper EH controller 202 . The ripper EH controller 202 can use the output of the pitch cylinder position sensor 234 to more accurately determine the position of the ripper relative to the main geometry of the tractor. As shown below, it is optional to include position sensors on the pitch cylinders for the ripper depth limiting system.
The ripper EH controller 202 processes the operator and sensor inputs and sends control signals to the lift spool valve 250 and the pitch spool valve 260 . The lift spool valve 250 includes a first movement actuator 252 and a second movement actuator 254 to move the lift spool valve 250 to a desired position. The lift spool valve 250 also includes an input side (bottom) coupled to a flow source P, for example a pump, and an output side (top) coupled to the lift cylinders 210 , 220 . The first movement actuator 252 can be used to move the lift spool valve 250 to retract the lift cylinders 210 , 220 . The second movement actuator 254 can be used to move the lift spool valve 250 to extend the lift cylinders 210 , 220 .
The pitch spool valve 260 includes a first movement actuator 262 and a second movement actuator 264 to move the pitch spool valve 260 to a desired position. The pitch spool valve 260 also includes an input side (top) coupled to a flow source P, for example a pump, and an output side (bottom) coupled to the pitch cylinders 230 , 240 . The first movement actuator 262 can be used to move the pitch spool valve 260 to retract the pitch cylinders 230 , 240 . The second movement actuator 264 can be used to move the pitch spool valve 260 to extend the pitch cylinders 230 , 240 .
FIG. 3 illustrates a more detailed view of an exemplary embodiment of the ripper EH controller 202 . The ripper EH controller 202 includes a table of geometric relationships 306 which can be used to determine ripper position relative to the tractor based on system parameters including ripper lift and pitch cylinder positions. The inputs from the lift cylinder position sensor 214 and the pitch cylinder position sensor 234 are processed by a cylinder position processor 304 which also uses the table of geometric relationships 306 to determine ripper position data. The ripper position data computed by the position processor 304 is sent to an operator command processor 302 and to a position limiting processor 310 .
The operator command processor 302 processes the ripper position data generated by the position processor 304 , along with the inputs from the operator lift and pitch controllers 204 , 206 , and the table of geometric relationships 306 to generates lift cylinder commands and pitch cylinder commands. The lift and pitch cylinder commands are both sent to the position limiting processor 310 .
The input from the ripper depth limit selector 208 is processed by a ripper depth limit processor 308 to generate a ripper depth limit command. The ripper depth limit command generated by the ripper depth limit processor 308 is sent to the position limiting processor 310 .
The position limiting processor 310 processes the inputs from the operator command processor 302 and the ripper depth limit processor 308 , and uses the table of geometric relationships 306 to determine lift and pitch cylinder commands to send to an output conditioning processor 312 . If the ripper depth limit option is active, and the operator commands would cause the ripper to exceed the depth limit, then the position limiting processor 310 would modify the ripper lift and pitch commands to execute the operator commands without exceeding the depth limit.
The output conditioning processor 312 sends commands from the ripper EH controller 202 to the lift spool valve 250 and the pitch spool valve 260 . The output conditioning processor 312 sends lift commands to the movement actuators 252 , 254 to position the lift spool valve 250 and control the lift cylinders 210 , 220 . The output conditioning processor 312 sends pitch commands to the movement actuators 262 , 264 to position the pitch spool valve 260 and control the pitch cylinders 230 , 240 .
FIG. 4 is a flow diagram of an exemplary implementation of a control process for the ripper depth limit that uses sensor readings from the lift cylinder(s) and not the pitch cylinder(s). When a command is processed, at block 402 the system checks if the ripper depth limit is activated. If the ripper depth limit is activated then control is passed to block 408 , otherwise control is passed to block 404 . At block 404 , the system checks if the command is a lift cylinder command. If the command is a lift cylinder command then control is passed to block 406 , otherwise the system returns to process the next command. At block 406 , the system executes the lift cylinder command and then returns to process the next command.
If the ripper depth limit option is activated, then at block 408 the system retrieves and sets the ripper depth limit and then at block 410 the system checks the length of the ripper lift cylinder(s). Then at block 412 , the system checks if the ripper depth limit is exceeded. If the ripper depth limit is exceeded then control is passed to block 414 , otherwise control is passed to block 416 . At block 414 , the system retracts the ripper lift cylinders to raise the ripper to the ripper depth limit, and then passes control to block 416 .
At block 416 the system waits for a lift cylinder command. When a lift cylinder command is received, control passes to block 418 where the system checks if the ripper depth limit option is still activated. If the ripper depth limit option is not still activated then at step 406 the lift cylinder command is executed and control is passed back to block 402 to wait for the depth limit option to be activated again. If the ripper depth limit option is still activated then control is passed to block 420 .
At block 420 the system determines whether the lift command will lower the ripper beyond the depth limit. If the lift command will not lower the ripper beyond the depth limit then the lift cylinder command is executed at block 422 , and control is passed back to block 416 to wait for the next lift cylinder command. If the lift command would lower the ripper beyond the depth limit then the lift cylinder command is revised at block 424 to only lower the ripper to the depth limit, the revised lift cylinder command is executed at block 422 , and control is passed back to block 416 to wait for the next lift cylinder command.
FIG. 5 is a flow diagram of an exemplary implementation of a control process for the ripper depth limit that uses sensor readings from both the lift and pitch cylinders. When a command is processed, at block 502 the system checks if the ripper depth limit is activated. If the ripper depth limit is activated then control is passed to block 508 , otherwise control is passed to block 504 . At block 504 , the system checks if the command is a ripper lift or pitch cylinder command. If the command is a ripper lift or pitch cylinder command then control is passed to block 506 , otherwise the system returns to process the next command. At block 506 , the system executes the ripper lift or pitch cylinder command, and then returns to process the next command.
If the ripper depth limit option is activated, then at block 508 the system retrieves and sets the ripper depth limit, then at block 410 the system checks the length of the ripper lift and pitch cylinders, and at block 512 the system determines the ripper depth. Then at block 514 , the system checks if the ripper depth exceeds the ripper depth limit. If the ripper depth limit is exceeded then control is passed to block 516 , otherwise control is passed to block 518 . At block 516 , the system retracts the ripper lift cylinders to raise the ripper to the ripper depth limit, and then passes control to block 518 .
At block 518 the system waits for a ripper lift or pitch cylinder command. When a ripper lift or pitch cylinder command is received, control passes to block 520 where the system checks if the ripper depth limit option is still activated. If the ripper depth limit option is not still activated then at step 506 the ripper lift or pitch cylinder command is executed and control is passed back to block 502 to wait for the depth limit option to be activated again. If the ripper depth limit option is still activated then control is passed to block 522 .
At block 522 the system determines whether the ripper lift or pitch command will lower the ripper beyond the depth limit. If the ripper lift or pitch command will not lower the ripper beyond the depth limit then the command is executed at block 524 , and control is passed back to block 518 to wait for the next ripper lift or pitch cylinder command. If the ripper lift or pitch command would lower the ripper beyond the depth limit then the command is revised at block 526 to only lower the ripper to the depth limit or raise the ripper to the depth limit if the pitch command would lower the ripper beyond the depth limit. From block 526 control is passed to block 524 where the revised lift or pitch cylinder command is executed, and then control is passed back to block 518 to wait for the next ripper lift or pitch cylinder command.
While exemplary embodiments incorporating the principles of the present invention have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
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A ripper depth limit system and method that includes a lift input for operator controls to raise and lower the ripper, a depth limit input, a lift sensor input that senses the ripper lift cylinder position, and a controller that processes the inputs to generate, execute and revise ripper lift cylinder commands that keep the ripper above the ripper depth limit. The depth limit input can select the ripper depth limit from a plurality of predefined depth limits, or between minimum and maximum ripper depths, or by some other method. The ripper depth limit system can also include a pitch input for operator controls of ripper pitch, and a pitch sensor that senses ripper pitch cylinder position, and the controller can process the pitch inputs to generate, execute and revise ripper pitch and lift cylinder commands that keep the ripper above the ripper depth limit.
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RELATED APPLICATIONS
This application claims the benefit of priority of U.S. Ser. No. 61/032,880, filed Feb. 29, 2008, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
The present disclosure is generally directed to filtration systems for a mobile surface maintenance machine. More specifically, the present disclosure is directed to a filtration system utilizing a filter shaker assembly for periodically removing debris from a filter surface.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to a filtration system for a mobile surface maintenance machine utilizing a filter shaker for periodically removing debris from a filter surface. The filtration system is preferably vacuum-based. In one embodiment, a filter stage is provided along with a debris hopper to allow dust and debris to be removed from a filter surface via activation of a filter shaker. Loosened dust and debris is deposited within the debris hopper. A preferred form of the invention utilizes a cylindrical pleated media filter.
A conventional forward throw cylindrical broom sweeper will be used by way of example in the following description of the invention. However, it should be understood that, as already stated, the invention could as well be applied to other types of mobile surface maintenance machines, such as, for example, other types of cylindrical broom sweepers and other machines such as sacrificers and various types of vacuum sweepers.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a perspective illustration of one embodiment of a cleaning machine utilizing a filter cleaning system in accordance with the present invention.
FIG. 2 is a perspective illustration of a hopper assembly and filter box of the cleaning machine of FIG. 1 .
FIG. 3 is a perspective illustration of a hopper assembly and filter box of the cleaning machine of FIG. 1 .
FIG. 4 illustrates a cross-sectional view of the hopper assembly and filter box of FIG. 2 .
FIG. 5 illustrates a cross-sectional view of the hopper assembly and filter box of FIG. 2 .
FIG. 6 illustrates a cross-sectional view of the hopper assembly and filter box of FIG. 2 .
FIG. 7 illustrates a cross-sectional view of the hopper assembly and filter box of FIG. 2 .
FIG. 8 illustrates a cross-sectional view of the hopper assembly and filter box of FIG. 2 .
FIG. 9 illustrates a cross-sectional view of the hopper assembly and filter box of FIG. 2 .
FIG. 10 is a perspective view of a filter and filter shaker components of the embodiment of FIG. 2 .
FIG. 11 is a perspective view of a filter and filter shaker components of the embodiment of FIG. 2 .
FIG. 12 is a perspective view of a filter shaker frame of the embodiment of FIG. 2 .
FIG. 13 is a perspective view of the shaker plate of FIG. 2 .
FIG. 14 is a detailed cross sectional view of the filter and filter shaker components of the embodiment of FIG. 2 .
FIG. 15 is a detailed cross sectional view of the filter and filter shaker components of the embodiment of FIG. 2 .
FIG. 16 is a top view of the main cover of the embodiment of FIG. 2 .
FIG. 17 is a bottom view of the main cover of the embodiment of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 , there is shown an industrial sweeping machine 10 . As shown, it is a forward throw sweeper. However, it could as well be an over-the-top, rear hopper sweeper, a type which is also well known in the art. It has a rotating cylindrical brush 12 for sweeping debris from a floor or other surface into a debris hopper assembly 14 . Hopper arms (not shown) allow hopper assembly 14 to be lifted during a dumping procedure. The broom chamber may be enclosed by skirts which come down nearly to the floor. The skirts largely contain within the broom chamber any dust stirred up by the broom. To complete the dust control there is a suction blower or vacuum fan 16 which exhausts air from the broom chamber to the atmosphere. Prior to exhaust, the air passes through hopper assembly 14 containing a filter module. Vacuum fan 16 maintains a sub-atmospheric pressure within the broom chamber so that air is drawn in under the skirts and through the filter module prior to exhaust. As a result, relatively little dust escapes from the broom chamber to the external environment. Various components of machine 10 have been left out of FIG. 1 , e.g., the drive engine and engine have been omitted to improve understanding of the aspects of the present invention. Additional aspects of machine 10 are disclosed in U.S. Pat. No. 5,940,928, said patent being incorporated by reference herein.
As shown in FIG. 2 , hopper assembly 14 of machine 10 includes air/debris inlet 20 through which air-entrained dust and debris enters via a mechanical throwing action by brush 12 and a vacuum action generated by vacuum fan 16 during a sweeping operation of machine 10 . Hopper assembly includes air outlet 22 through which filtered air is drawn by operation of vacuum fan 16 . During a hopper dumping procedure, dust and debris within hopper assembly 14 exits debris inlet 20 . Attached to hopper assembly 14 is a filter module including main cover 24 , filter cover 25 and tray 26 .
FIG. 3 depicts the hopper assembly of FIG. 2 with main cover 24 and filter cover 25 removed. A portion of cylindrical filter 28 is exposed. Dust is retained on outer surfaces of filter 28 as air is drawn toward the filter's center by action of vacuum fan 16 . Air at the center of filter 28 is then directed out of air outlet 22 of filter cover 25 and toward vacuum fan 16 .
FIG. 4 is a cross-sectional view of hopper assembly 14 of FIG. 2 . In the illustrated embodiment, a filter module includes three different filter sections for removing dust and debris from an air stream, namely prefilter 32 , cyclonic filters/vortex separators 34 and a cylindrical filter 28 . The arrows in FIG. 4 generally depict air flow through hopper assembly 14 during machine operation. This filter system removes dust from the air stream so the vacuum fan will exhaust relatively clean air to the atmosphere. The filter module includes a bank of cyclonic filters 34 through which dusty air passes causing separation and retention of at least some of the larger dust particles and debris. Dust and debris exiting the bottom apertures of cyclonic filters 34 is deposited on collection surface 35 of the filter module. During a sweeping operation, dust and debris remains on surface 35 as an outlet is sealed by flexible seal 36 by way of vacuum action. Dust and debris on surface 35 is periodically removed during a hopper dumping procedure. During such a procedure, with the vacuum fan 16 uncoupled to hopper assembly 14 , seal 36 is free to swing open allowing dust and debris to pass through the outlet previously blocked by seal 36 .
During machine operation, air enters the filter module through prefilters 32 and passes through the vortex separators 34 prior to being filtered by the cylindrical filter. A vortex is created by the channels and conical sections below the channels as air spirals in a path moving downward and inward, then upward in a helical path to exit at an upper opening. The centrifugal acceleration due to rapid rotation of the air causes dense particles to be forced outward to the wall of the cones of vortex separators 34 . The dense particles are transported in a slow moving boundary layer downward toward the apex openings 38 . During operation, air passes from vortex separators 34 through openings 39 to the cylindrical filter for subsequent filtering.
FIG. 5 is another cross-sectional view of hopper assembly 14 . Cylindrical filter 28 is shown in cross section with a shaker motor 40 positioned within the central open interior of filter 28 . Filter 28 and shaker motor 40 are supported above collection surface 42 by support frame 44 . Shaker motor 40 is coupled to a pair of eccentric masses 46 , 48 which are periodically rotated by motor 40 to impart a shaking action to filter 28 . Dust and debris removed from outer surfaces of filter 28 via a filter shaking procedure drops onto collection surface 42 . During a sweeping operation, flexible seal 49 is held closed by vacuum action thereby retaining debris on collection surface 42 . During a hopper dumping procedure with vacuum fan 16 uncoupled, flexible seal 49 opens to release debris on collection surface 42 for passage out of hopper assembly 14 at inlet opening 20 .
In one preferred embodiment of the invention, cylindrical filter 28 includes a pleated media filter, such as are manufactured, for example, by Donaldson Company, Inc. of Minneapolis, Minn. In one embodiment, filter 28 has a pleated media, with the pleats running parallel to the centerline of the cylinder, which makes them vertical when installed as shown. The pleated media is surrounded with a perforated metal sleeve for structural integrity. Outside the metal sleeve may be provided a fine mesh sleeve (not shown) woven from a slippery synthetic filament which stops the coarser dust and sheds it easily during a filter cleaning cycle. Other types of filter technologies may be applicable for implementation within filter 28 .
FIG. 6 is a cross-sectional view of hopper assembly components. Flexible seals 36 , 49 are shown in this drawing. Collection surface 35 is separated from collection surface 42 by wall 51 . A pressure differential may exist across wall 51 as pressure within the vortex separator section may be different than pressure within the cylindrical filter section.
FIG. 7 depicts cylindrical filter 28 held between filter cover 25 and a filter support frame 44 above debris collection surface 42 . The filter support frame 44 includes a pair of frame arms attached to base 62 . The filter support frame 44 is secured via fasteners 63 passing through frame arm ends to a rigid portion of the hopper assembly. As a result, the filter support frame 44 is substantially secured against movement within the hopper assembly 14 .
FIGS. 8 and 9 are cross sectional views of filter 28 , shaker mechanism components and the filter support frame 44 . Shaker mechanism includes a pair of eccentric masses 46 , 48 mounted to shaft 74 of motor 40 . Motor 40 may be electric or hydraulic-based. Motor 40 is secured to shaker plate 77 via, for example, threaded fasteners. Upon activation of motor 40 , the weights 46 , 48 rotate and vibrate shaker plate 77 and filter 28 at a frequency dependent on motor speed. In a preferred embodiment of the invention, an electric motor 40 is entirely received within a center cavity of cylindrical filter 28 . As shown in FIG. 9 , shaker plate 77 includes filter support 78 which engages a bottom surface of filter 28 and limits a degree of gasket compression as described in more detail below.
FIG. 10 illustrates cylindrical filter 28 and support frame 44 . A flexible gasket 79 engages shaker plate 77 and another gasket 79 engages the underside of cover 25 (not shown) during operation. Together the gaskets 79 seal the interior of filter 28 and prevent air leakage around filter 28 . Filter support 78 controls the position of filter 28 relative to shaker plate 77 and thus limits the degree of gasket 79 compression.
FIG. 11 is a perspective view of components of the filter support frame and shaker mechanism. Shaker plate 77 is supported upon a slide bearing 80 , which is supported upon support plate 62 . During shaker mechanism operation, shaker plate 77 slides upon bearing 80 in response to movement of eccentric masses 46 , 48 . The rotational range of motion of shaker plate 77 is limited by pins 82 attached to the frame base plate 62 . Pins 82 may engage edges of apertures 84 during motor 40 start up or during machine operation to prevent further rotation of shaker plate 77 . Reinforcement structure, in this example welded stops, are provided around apertures 84 to minimize wear to shaker plate 77 , base plate 62 and/or pins 82 . Together the pins 82 and apertures 84 cooperate to limit the rotational range of motion of shaker plate 77 relative to the filter support frame 44 . In the illustrated embodiment as shown in FIG. 12 , a pair of pins 82 are connected to base plate 62 . A third pin 82 is connected to shaker plate 77 . As shown in FIG. 13 , a pair of slot apertures 84 are defined on shaker plate 77 and a third slot aperture 84 is defined on base plate 62 . This arrangement of pins 82 and apertures 84 prevents the shaker assembly from being assembled improperly during manufacturing or use.
FIG. 12 is a perspective view of frame support arms of the filter support frame 44 and base plate 62 . In a preferred embodiment, tabs and slots 85 are defined in frame support arms of the filter support frame 44 and base plate 62 to aid in alignment, durability and/or manufacturability of the filter support frame 44 . Base plate 62 includes a center aperture 100 defined by a circular edge 102 .
FIG. 13 is a perspective view of shaker plate 77 . Apertures 120 receive fasteners to secure electric motor 40 to shaker plate 77 . Wiring for electric motor 40 passes through aperture 124 . Motor shaft 74 passes through aperture 123 .
FIGS. 14-15 are cross sectional views of the shaker mechanism components and filter 28 . The shaker mechanism includes a pair of cylindrical rings 90 , 92 which are secured to shaker plate 77 . Cylindrical ring 90 is sized in relation to the inside diameter of filter 28 so as to snuggly engage and retain filter 28 against shaker plate 77 . Cylindrical ring 92 is sized in relation to the diameter of center aperture 100 of base plate 62 . The size difference (or clearance) between ring 92 and aperture 100 is shown by dimension, DP. Ring 92 has a smaller diameter than that of aperture 100 so that shaker plate 77 can slide/rotate relative to base plate 62 . During operation, ring 92 may contact the edge 102 of aperture 100 so as to limit the range of shaker motion. In a preferred embodiment, ring 92 is sized relative to aperture 100 so as to provide sufficient movement of shaker plate 77 in order to generate impulses upon contact between ring 92 and edge 102 . In other embodiments, ring 92 may engage a differently configured structure of support plate 62 . For example, edge 102 include additional support material provide additional durability. As a result, ring 92 and aperture 100 cooperate to limit the range of motion of shaker plate 77 relative to the filter support frame.
The control of filter shaker mechanism is via an on-board controller of machine 10 . The controller may automatically activate the electric motor 40 of the shaker mechanism after a period of time has elapsed or upon receipt of a signal from a pressure switch indicating that the filter has become occluded. A differential pressure sensor/switch may be used across filter 28 to detect filter condition. As dust gradually accumulates on filter 28 , the differential pressure will rise. When it reaches a predetermined value the pressure switch will close, which will initiate an automatic filter cleaning cycle. The time period during which electric motor 40 is activated may be predetermined. Alternatively, activation of the electric motor 40 to perform a filter shake procedure may be via a manual switch utilized by a machine operator.
FIG. 16 is a top perspective view of main cover 24 showing filter opening 141 through which filter 28 can be accessed during inspection, replacement, etc. The filter cover 25 (not shown) is secured to main cover 24 by threaded fasteners (not shown) engaging threaded components 142 . Main cover 24 defines an air conduit 143 through which filtered air travels toward vacuum fan 16 . Conduit 143 includes a mating surface 144 which is sealed against a surface of filter cover 25 .
FIG. 17 is a bottom perspective view of main cover 24 showing a plenum portion 151 connected to a plurality of vortex-forming spiral walls 152 . Some of the walls 152 spiral in one direction and other walls 152 spiral in an opposite direction. A lower surface 153 of main cover 24 engages tray 26 (shown in FIG. 4 ) of the filter assembly. Dusty air from the hopper assembly enters plenum 151 at plenum entrance 154 . Plenum 151 effectively distributes airflow across the various spiral walls 152 so as to maintain a balanced dust removal among the vortex separators. Air exits this portion of main cover 24 through openings 156 and passes into a generally enclosed volume of cover 24 .
Advantages of a shaker mechanism in accordance with the present invention include: a cleaner operating environment for shaker motor 40 as motor 40 is position inside cylindrical filter 28 ; the pair of eccentric masses 46 , 48 tend to provide a balanced, radial shaking motion to filter 28 ; filter 28 durability may be improved by providing a balanced, radial shaking motion; and noise generated during shaker mechanism operation can be minimized by providing a balanced shaker assembly.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
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A filter shaking assembly for a floor surface maintenance machine including a filter assembly in fluid communication with the debris hopper and having a cylindrical filter held against a shaker plate. The shaker plate is vibrated by a shaker motor at least partially positioned within an interior of the filter and eccentric mass to remove an accumulation of debris from the surface of the filter. The eccentric mass may include two eccentric masses positioned on a common shaft of the shaker motor.
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TECHNICAL FIELD
The invention relates to the transmission of Dual-Tone Multi-Frequency ("DTMF") signals within a telecommunication network.
BACKGROUND OF THE INVENTION
DTMF signals are employed within telecommunication systems to initiate calls, and facilitate control of certain services and/or equipment. The services and/or equipment may be both internal and external to the particular network facilitating a call. For example, codes called "triggers", comprised of one or more DTMF signals, allow network subscribers to control network-based services such as multi-party conferencing. Network subscribers may also need to transmit, via the network, DTMF triggers to equipment and services external to the network, such as answering machines and automated banking services.
Network subscribers have had little control as to the propagation of DTMF signals which they transmit, giving rise to a number of potential problems. For example, assume a network subscriber placed a call to a particular party via a network offering multi-party conferencing in response to a DTMF trigger received from the subscriber. During the course of the call, the conferencing feature allows a subscriber to instruct the network, via a transmitted DTMF trigger, to connect additional parties to the call. The transmitted DTMF trigger would be detected by network-based equipment which would perform the requested connection of the additional party or parties. Unfortunately, like any other audio band signal sent from the subscriber's telephone, the DTMF trigger would also be transmitted to the originally called party. Such audible signals would disrupt any communication with that first called party. For obvious reasons, such disruptions are undesirable.
Arbitrarily blocking all DTMF signals at some point within the network between the network-based equipment to which a network subscriber must transmit DTMF triggers, and the party with whom the subscriber is connected would prohibit DTMF signals from disrupting communications with that party. However, this blocking would also prevent a subscriber from transmitting DTMF triggers to equipment and services external to the network. Previously known network-based arrangements have provided for detecting and selectively blocking a limited number of unique triggers intended for equipment internal to a particular network, while allowing all other DTMF signals to propagate to parties/equipment external to the network. However, these arrangements are limited in their versatility, and cause unacceptable propagation delays within a network.
SUMMARY OF THE INVENTION
The aforementioned problems are solved, in accordance with the principles of the invention, by monitoring a network communications channel to detect specific DTMF triggers transmitted by a network user during either a pre-answer or a post-answer period of a call supported by the channel, and, in response to the detected DTMF triggers, controllably prohibiting the propagation of subsequent DTMF signals transmitted over the channel by the network user. Specifically, possible disruption of a communication between the network user and other parties caused by transmission of DTMF signals is eliminated by advantageously transmitting the DTMF triggers during the pre-answer period of a call. Furthermore, another deficiency of prior network-based arrangements for restricting the propagation of DTMF signals is overcome, as the invention may be practiced without the introduction of any significant propagation delay to a network.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 shows, in simplified block diagram form, a telecommunication system incorporating the invention;
FIG. 2 is a functional block diagram of one of the DTMF signal detector/processors of FIG. 1;
FIG. 3 shows, in simplified block diagram form, the internal architecture of one of the switches of FIG. 1;
FIG. 4 is a flow diagram of operations required to enable a calling party to selectively control the propagation of DTMF signals within the telecommunication system of FIG. 1;
FIG. 5 is a flow diagram of operations required to enable a called party to selectively control the propagation of DTMF signals within the telecommunication system of FIG. 1;
FIG. 6 shows, in simplified block diagram form, a second telecommunication system incorporating the invention;
FIG. 7 is a functional block diagram of one of the DTMF signal detector/processor of FIG. 5;
FIG. 8 shows, in simplified block diagram form, the internal architecture of one of the switches of FIG. 5;
FIGS. 9 and 10 form a flow diagram of operations required to enable a calling party to selectively control the propagation of DTMF signals within the telecommunication system of FIG. 6; and
FIGS. 11 and 12 form a flow diagram of operations required to enable a called party to selectively control the propagation of DTMF signals within the telecommunication system of FIG. 6.
DETAILED DESCRIPTION
FIG. 1 is a simplified block diagram showing a telecommunication system which allows the practice of a particular method of this invention. Employing this system, a user may controllably prohibit (i.e., block) transmitted DTMF signals from being propagated to another network user, while still allowing the DTMF signals to reach network-based equipment. Specifically shown is telecommunication network 100, including switch 101, DTMF signal detector/blocker ("SDB") 102, DTMF-responsive network equipment 103, DTMF SDB 104, and switch 105. Also shown is Local Exchange Carrier ("LEC") 106, which provides switch 101 with a connection to network user 107, and LEC 108, which provides switch 105 with a connection to network user 109. Communications channel 110 is intended to support a call linking network users 107 and 109 via the LECs 106 and 108, and network 100. For purposes of illustration, communications channel 110 is shown as a bold line. Control messages used in practicing the invention are transmitted between DTMF SDB 102 and switch 101 via communication link 111. Similarly, control messages used in practicing the invention are transmitted between DTMF SDB 104 and switch 105 via communication link 112. Such communication links are well known in the art, and commonly employed in conjunction with electronic switches to facilitate the transfer of control messages to and from other equipment within the network. Network 100 is configured so that all calls for which switch 101 serves as a terminating switch are routed through DTMF SDB 102, and so that all calls for which switch 105 serves as a terminating switch are routed through DTMF SDB 104.
FIG. 2 shows, in simplified form, the basic functional configuration of DTMF SDB 104 of the above-described network. As shown, DTMF SDB 104 includes DTMF detector 201, DTMF blocker 202, control line 203, and signal generator 204. DTMF detector 201 is adapted to monitor signals along communications channel 110 which are bound for switch 105, for the purpose of detecting either of two particular DTMF triggers: an "enabling" DTMF trigger, and a "disabling" DTMF trigger. Methods for detecting DTMF signals are known in the art, and a preferred method of performing such detection is disclosed in co-pending U.S. patent application Ser. No. 07/857,552, filed Mar. 23, 1992 (R. S. Dighe, Case 5). Each DTMF trigger consists of a unique series of one or more DTMF signals. In response to the detection of an enabling DTMF trigger or a disabling DTMF trigger, detector 201 transmits a signal indicative of the particular DTMF trigger detected to DTMF blocker 202 via control line 203. In addition, detector 201 also transmits a control message indicative of the detection of a DTMF trigger to switch 105, via communication link 112. DTMF blocker 202 is either enabled or disabled dependent upon the particular signals received via control line 203 and communication link 112. When enabled, DTMF blocker 202 is adapted to prohibit the propagation of DTMF signals received via communications channel 110; such DTMF blockers are known in the art. Signal generator 204 transmits an audible prompt signal along communications channel 110 to network user 107 (FIG. 1) in response to a signal received from switch 105 via communication link 112. This audible prompt serves as an indication to network user 107 that DTMF triggers may be keyed in. The configuration and operation of DTMF SDB 102 is similar to that of DTMF SDB 104, however, DTMF SDB 102 monitors signals along communications channel 110 which are bound for switch 101, and transmits control messages indicative of detected DTMF triggers to switch 101, via communication link 111.
Switches 101 and 105 in the above-described network are each program-controlled electronic switching systems. FIG. 3 is a functional block diagram of switch 105 illustrating the basic architecture of the switch. As shown, contained within switch 105 are the following components: incoming trunk interface 301, outgoing trunk interface 302, switching circuitry 303, processor 304, and memory 305. Memory 305 contains a program, the function of which with respect to the invention is described below. Memory 305 also contains call records for maintaining data associated with the various calls being handled by switch 105. Processor 304 is coupled to send and receive control messages via communication link 112. Switch 101 (FIG. 1) has the same basic architecture as switch 105, however, the processor contained within switch 101 receives control messages via communication link 111 (FIG. 1). Program-controlled electronic switching systems such as these are known and commercially available. An example of one such switching system is the 4 ESS™ switch manufactured by AT&T, and described in The Bell System Technical Journal, Vol. 56, No. 7, September 1977.
In practicing a particular method of the invention facilitated by the telecommunication system shown in FIG. 1, network user 107 initiates a call by entering the telephone number associated with network user 109. This call is routed via LEC 106 to network 100. As a function of the entered telephone number, switch 101 secures a voice channel connection to switch 105 in a standard manner. The voice channel connection is effected through DTMF-responsive network equipment 103 and DTMF SDB 104. However, prior to completing the voice channel connection to network user 109 via LEC 108, switch 105 sends a control message to signal generator 204 (FIG. 2) of DTMF SDB 104, which initiates the transmission of an audible prompt to network user 107. The time from the completion of a voice channel connection between network user 107 and switch 105, and the time at which a voice channel connection between network user 107 and network user 109 is completed, is the "pre-answer" period. Switch 105 then pauses for a pre-programmed interval, in accordance with the principles of the invention. This pre-programmed interval allows network user 107 time to key in a DTMF trigger. Switch 105 is directed to perform these functions as a result of the program stored within memory 305 (FIG. 3), and executed by processor 304 (FIG. 3). In addition, this program prohibits switch 105 from effecting a voice channel connection to LEG 108 until a control message indicative of the detection of a DTMF trigger has been received by processor 304 (FIG. 3) from DTMF SDB 104, via communication link 112, or until the pre-programmed pause interval has elapsed (whichever occurs first). Upon receipt of the audible prompt, network user 107 transmits an enabling DTMF trigger to DTMF SDB 104 via communications channel 110 (assuming network user 107 wished to prohibit subsequently transmitted DTMF signals from being propagated to network user 109). The transmitted enabling DTMF trigger is not detected by DTMF SDB 102, as DTMF SDB 102 only monitors signals bound for switch 101. As described above, DTMF SDB 104 prohibits the further propagation of DTMF signals received via communications channel 110 in response to detecting the enabling DTMF trigger, and transmits an indicative control message, via communication link 112, to switch 105. Upon receipt of this control message by switch 105, the program stored within memory 305 of switch 105 instructs processor 304 to complete a voice channel connection between network users 107 and 109, via LEC 108. All DTMF signals transmitted by network user 107 will be prohibited from reaching network user 109 for the remainder of the call, or until network user 107 transmits a disabling DTMF trigger. Furthermore, in accordance with the principles of the invention, even the DTMF trigger which initiated the blocking is kept from reaching network user 109, as it was transmitted prior to the establishment of a voice channel connection.
The transmission of a disabling DTMF trigger by network user 107 may be effected at any time during a call. This disabling DTMF trigger is transmitted to DTMF SDB 104 via communications channel 110. In response to detecting this disabling DTMF trigger, DTMF SDB 104 disables any restrictions on the propagation of subsequent DTMF signals received via communications channel 110. DTMF SDB 104 also transmits a control message indicative of DTMF trigger detection to switch 105, via communication link 112. However, as a voice channel connection already exists, the reception of this control message by switch 105 has no effect. All DTMF signals transmitted by network user 107 will now be allowed to reach network user 109 for the remainder of the call, or until network user 107 transmits an enabling DTMF trigger. In accordance with the principles of the invention, the DTMF trigger which disabled the blocking is kept from reaching network user 109, as it was transmitted while blocking was still in effect.
If in the above-described example, network user 107 did not wish to limit the propagation of DTMF signals, an enabling DTMF trigger would not have been transmitted in response to the audible prompt received from switch 105. Consequently, DTMF SDB 104 would not have transmitted a control message indicative of DTMF trigger detection to switch 105. Nevertheless, a voice channel connection between network users 107 and 109 would still be established by switch 105 after the pre-programmed pause interval had elapsed. This voice channel connection would permit the unrestricted propagation of DTMF signals to parties and equipment outside of network 100. However, by transmitting an enabling DTMF trigger, network user 107 could enable DTMF blocking at any time during the post-answer period of a call supported by this voice channel connection. DTMF SDB 104 would respond to this DTMF trigger in the same manner as it would to one received during the pre-answer period of a call, and limit the propagation of DTMF signals. This DTMF signal propagation limiting would remain in effect for the remainder of the call, or until a disabling DTMF trigger was received by DTMF SDB 104.
If network user 107 did not wish to initially restrict the propagation of DTMF signals, the completion of a voice channel connection could be expedited by immediately transmitting the disabling DTMF trigger upon receipt of the audible prompt from switch 105. This would cause DTMF SDB 104 to transmit a control message indicative of DTMF trigger detection to switch 105 via communication link 112. Upon receiving this control message, switch 105 is programmed to complete the voice channel connection between network users 107 and 109 via LEC 108. This voice channel connection would presumably be completed in slightly less time than one that would have resulted if network user 107 had simply allowed the pre-programmed pause interval to elapse without transmitting a DTMF trigger.
In each of the above-described examples, the network user employing the invention was the calling party. However, the invention may be practiced so as to allow the called party (network user 109 in above examples) to controllably prohibit transmitted DTMF signals from being propagated to the calling party (network user 107), while still allowing these signals to reach DTMF-responsive network equipment 103. In a manner similar to that employed by a calling network user, called network user 109 may transmit an enabling DTMF trigger to DTMF SDB 102, so as to controllably prohibit the propagation of DTMF signals to network user 107. This enabling DTMF trigger is transmitted via communications channel 110, but will not be detected by DTMF SDB 104, as DTMF SDB 104 only monitors signals bound for switch 105. DTMF SDB 102 operates in conjunction with switch 101 and communication link 111 in much the same manner as DTMF SDB 105 does with switch 105 and communication link 112. In response to detecting the enabling DTMF trigger, DTMF SDB 102 prohibits the further propagation of DTMF signals received via communications channel 110. DTMF SDB 102 also transmits a control message indicative of DTMF trigger detection to switch 101, via communication link 111. However, as a voice channel connection already exists, the reception of this control message by switch 101 has no effect. All DTMF signals transmitted by network user 109 will be prohibited from reaching network user 107 for the remainder of the call, or until network user 109 transmits a disabling DTMF trigger. The only constraint upon the use of the invention by a called party is the obvious limitation of not being able to initiate DTMF propagation restrictions during the pre-answer period of a call.
In all of the above-described examples, upon termination of a call all DTMF blocking associated with the voice channel connection that was supporting the call is disabled. This disabling is achieved as a function of the programming of the switches within network 100. When a call is terminated, the switch serving the calling party, and the switch serving the called party, each transmit a termination control message to their associated DTMF SDB. This terminating control message instructs the DTMF blocker within the DTMF SDB to disable DTMF blocking.
FIG. 4 is a flow diagram illustrating the sequence of operations effected within network 100 in providing the controllable DTMF propagation limiting service described above to a calling party. Accordingly, the sequence is entered into via step 401. Thereafter, a voice channel connection is initiated in operational block 402 by accepting the telephone number of the called party from the calling party. Operational block 403 then transmits an audible prompt to the calling party. Conditional branch point 404 tests to determine if the enabling DTMF trigger has been transmitted by the calling party. If the test result is YES, DTMF blocking is enabled in operational block 406. If the test result in step 404 is NO, conditional branch point 405 tests to determine if a disabling DTMF trigger has been transmitted by the calling party. If the test result is YES, DTMF blocking is disabled in operational block 407. If the result in step 405 is NO, conditional branch point 408 tests if the pre-programmed pause interval has elapsed. If the pre-programmed pause interval has not elapsed (a test result of NO), the operation continues with conditional branch point 404. If a test result of YES is obtained in step 408, conditional branch point 409 tests if a voice channel connection to the called party has been completed. If a call is in progress (a test result of YES), the operation branches to conditional branch point 410. If the test result in step 409 is NO, a voice channel connection to the called party is effected by operational block 411, which branches to conditional branch point 410. Conditional branch point 410 tests if the call has been terminated. If the test result is NO, the operation continues with conditional branch point 404. If the call has been terminated (a test result of YES), conditional branch point 412 tests if DTMF blocking had been enabled as of call termination. If this test result is NO, the operation is exited via step 413. If the result of the test in step 412 is YES, DTMF blocking is disabled in operational block 414, and then operation is terminated via step 412.
FIG. 5 illustrates the sequence of operations effected within network 100 in providing the controllable DTMF propagation limiting service described above to a called party. The sequence is entered into via step 501, and then conditional branch point 502 tests to determine if the enabling DTMF trigger has been transmitted by the called party. If the test result is YES, DTMF blocking is enabled in operational block 504. If the test result in step 502 is NO, conditional branch point 503 tests to determine if the disabling DTMF trigger has been transmitted by the called party. If the test result is YES, DTMF blocking is disabled in operational block 505. If the test result in step 503 is NO, the operation continues with conditional branch point 506; operational blocks 504 and 505 also branch to conditional branch point 506. Conditional branch point 506 tests if the call has been terminated. If the call is still in progress (a test result of NO), the operation branches to conditional branch point 502. If a test result of YES is returned, conditional branch point 507 tests if DTMF blocking had been enabled as of call termination. If this test result is NO, the operation is exited via step 508. If the result of the test in step 507 is YES, DTMF blocking is disabled in operational block 509, and then operation is terminated via step 508.
A telecommunication network system facilitating the practice of yet another method of the invention is illustrated in FIG. 6. Specifically shown is telecommunication network 600, including switch 601, DTMF SDB 602, DTMF responsive network equipment 603, DTMF SDB 604, switch 605, and signaling system 606. Signaling system 606 is a common channel signalling system, such as a Signaling System 7, which is well known in the art. Also shown is LEC 607, which provides switch 601 with a voice channel connection to network user 608, and LEC 609, which provides switch 605 with a voice channel connection to network user 610. Also shown is communications channel 611, which is intended to support a call linking network users 608 and 610 via the LECs 607 and 609, and network 600. For purposes of illustration, communications channel 611 is shown as a bold line. Control messages used in practicing the invention are transmitted between DTMF SDB 602 and switch 601 via communication link 612. Similarly, control messages used in practicing the invention are transmitted between DTMF SDB 604 and switch 605 via communication link 613. Such communication links are well known in the art, and commonly employed in conjunction with electronic switches to facilitate the transfer of control messages between switches and other network equipment. Network 600 is configured so that all calls for which switch 601 serves as a terminating switch are routed through DTMF SDB 602, and so that all calls for which switch 605 serves as a terminating switch are routed through DTMF SDB 604.
FIG. 7 shows, in simplified form, the basic functional configuration of DTMF SDB 604 (FIG. 6) of the above-described network. As shown, DTMF SDB 604 (FIG. 6) includes DTMF detector 701, DTMF blocker 702, and control line 703. DTMF detector may be put into an active or inactive state as a function of control messages received from switch 605 (FIG. 6). When active, DTMF detector 701 monitors signals along communications channel 611 bound for switch 605 for the purpose of detecting the presence of either an enabling DTMF trigger, and/or a disabling DTMF trigger. Methods for detecting DTMF signals are known in the art. Each of these DTMF triggers consists of one or more DTMF signals. In response to the detection of an enabling DTMF trigger or a disabling DTMF trigger, detector 701 transmits a signal indicative of the particular DTMF trigger detected to DTMF blocker 702, via control line 703. DTMF blocker 702 is either enabled or disabled dependent upon the particular signal received. DTMF blocker 702 may also be enabled or disabled in response to control messages received from switch 605 (FIG. 6). When enabled, DTMF blocker 702 is adapted to prohibit the propagation of DTMF signals received via communications channel 611. The configuration and operation of DTMF SDB 602 (FIG. 6) is similar to that of DTMF SDB 604, however DTMF SDB 602 monitors signals along communications channel 611 which are bound for switch 601 (FIG. 6), and transmits control messages indicative of detected DTMF triggers to switch 601, via communication link 612.
Switches 601 and 605 in the above-described network are each program-controlled electronic switching systems. FIG. 8 is a functional block diagram of switch 605 illustrating the basic architecture of the switch. As shown, contained within switch 605 are the following components: incoming trunk interface 801, outgoing trunk interface 802, switching circuitry 803, processor 804, and memory 805. Memory 805 contains a program, the function of which with respect to the invention is described below. Memory 805 also contains call records for maintaining data associated with the various calls being handled by switch 605, and an Automatic Number Identification ("ANI") data base 806. ANI data base 806 contains a listing of the telephone numbers of the network users serviced by switch 605 who subscribe to the DTMF propagation limiting service available within network 600. ANI data base 806 also contains a listing of service profiles for each of these subscribers. Each service profile indicates whether the associated subscriber has requested that DTMF signals be automatically prohibited from propagating to called parties whenever a call is completed. This profile information is programmed into data base 806 to reflect information previously provided by subscribers. Processor 804 is coupled to send and receive information via communication link 613, and signaling system 605. Switch 601 (FIG. 6) has the same basic architecture as switch 605, however, the processor contained within switch 601 receives control messages via communication link 612 (FIG. 6). The 4 ESS™ switch, is one type of commercially available program-controlled electronic switching system which may be configured as described above.
In practicing a particular method of the invention facilitated by the telecommunication system shown in FIG. 6, network user 608, a subscriber to the DTMF propagation limiting service available within network 600, initiates a call by entering the telephone number associated with network user 610. In a standard manner, switch 601 secures a voice channel voice channel connection to switch 605 as a function of the entered telephone number. However, prior to completing the voice channel connection to network user 610, the programming of switch 605 causes it to wait for the arrival of a profile message from switch 601, via signaling system 606. The time from the completion of a voice channel connection between network user 608 and switch 605, and the time at which a voice channel connection between network user 608 and network user 610 is completed, is the "pre-answer" period. As with all subscribers to the DTMF propagation limiting service, network user 608's telephone number and associated service profile are stored in the ANI data base contained within the serving network switch (in this case, switch 601). Assume that the stored service profile for network user 608 indicates that all DTMF signals should be automatically prohibited from propagating to parties called by user 608 whenever a call is completed.
When the call to network user 610 was initiated by network user 608, an ANI system forwarded the telephone number of network user 608 from LEC 607 to switch 601 in a standard manner. Upon receipt of network user 608's telephone number, switch 601 performs a check of its internal ANI data base to determine if network user 607 is subscribed to the DTMF propagation limiting service. After confirming that this is the case, switch 601 retrieves the service profile associated with user 608 from the ANI data base. Switch 601 then transmits a message reflecting this profile to switch 605, via signaling system 606. In response to the arrival of this profile message, the programming of switch 605 causes an enabling control message to be transmitted from switch 605 to DTMF SDB 604. This control message, which is transmitted via communication link 613, enables DTMF blocker 702, and activates DTMF detector 701. In addition, receipt of the profile message by switch 605, the programming of switch 605 causes the voice channel connection to network user 610 to be completed in a standard manner. All DTMF signals transmitted by network user 608 will be prohibited from reaching network user 610 for the remainder of the call, or until network user 608 transmits a disabling DTMF trigger.
The transmission of a disabling DTMF trigger by network user 608 may be effected at any point during a call. This disabling DTMF trigger is transmitted to DTMF SDB 604 via communications channel 611. In response to detecting this disabling DTMF trigger, DTMF SDB 604 disables any restrictions on the propagation of DTMF signals received via communications channel 611. All DTMF signals transmitted by network user 608 will be allowed to reach network user 610 for the remainder of the call, or until network user 608 transmits an enabling DTMF trigger.
If in the above-described example, network user 608 was a DTMF propagation limiting service subscriber who did not wish for transmitted DTMF signals to be automatically prohibited from propagating to called parties whenever a call was completed, the service profile stored within the ANI data base of switch 601 would have indicated such. When a message reflecting such a service profile was received by switch 605, DTMF blocker 702 (FIG. 7) would not have been enabled. However, DTMF detector 701 (FIG. 7) would still have been activated, and a voice channel connection to network user 610 would still have been completed. All DTMF signals transmitted by network user 608 would have been allowed to reach network user 610 for the remainder of the call, or until network user 608 transmitted an enabling DTMF trigger.
If in the above example, network user 608 did not subscribe to the DTMF propagation limiting service available within network 600, a listing of network user 608's telephone number would not be stored within the ANI data base of switch 601. Consequently, no service profile would be retrieved for network user 608 in response to a call initiated to network user 610. Lacking a service profile, the programming of switch 601 would cause a default profile message to be transmitted to switch 605, and a voice channel connection to network user 610 would be established. However, this default profile signal would not initiate the activation of DTMF detector 701 (FIG. 7), or the enabling of DTMF blocker 702 (FIG. 7). All DTMF signals transmitted by network user 608 would be allowed to reach network user 610 for the remainder of the call, regardless of any DTMF triggers transmitted by network user 608.
In each of the above-described scenarios involving the telecommunication system of FIG. 6, the network user employing the invention was the calling party. However, the invention may be practiced by the called party (network user 610 in above examples). Assume that network user 610 is a subscriber to the DTMF propagation limiting service available from network 600, and that the service profile stored within switch 605 indicates that network user 610 has requested that all DTMF signals be automatically prohibited from propagating to calling parties. Upon effecting a voice channel connection to network user 610, switch 605 is programmed to perform a check of its internal ANI data base to determine if the called number (the number associated with network user 610) is that of a subscriber. After confirming that this is the case, switch 605 retrieves the service profile associated with user 610 from ANI data base 806 (FIG. 8). Switch 605 then transmits a message reflecting this profile to switch 601, via signaling system 606. In response to the arrival of this profile message, the programming of switch 601 enables the DTMF blocker, and activates the DTMF detector within DTMF SDB 602. All DTMF signals transmitted by network user 610 will be prohibited from reaching network user 608 for the remainder of the call, or until network user 610 transmits a disabling DTMF trigger. Naturally, the service profile of any given called party may instruct the appropriate DTMF SDB to automatically provide whatever combinations of DTMF blocking and DTMF tone detection that called party desires.
In the examples of the invention discussed with respect to the network of FIG. 6, all DTMF blocking associated with a voice channel connection supporting a call is disabled upon termination of that call. This is facilitated as a function of the programming of the switches within network 600. When a call is terminated, the switch serving the calling party, and the switch serving the called party, each transmit a termination control message their associated DTMF SDB. This terminating control message instructs the DTMF blocker within the DTMF SDB to disable DTMF blocking.
FIGS. 9 and 10 together form a flow diagram illustrating the sequence of operations effected within network 600 in providing the controllable DTMF propagation limiting service described above to a calling party. As shown in FIG. 9, the sequence is entered into via step 901. Thereafter, a voice channel connection is initiated in operational block 902 by accepting the telephone number of the called party from the calling party. Conditional branch point 903 tests to determine if the calling party is a subscriber to the DTMF propagation limiting service. If a test result of NO is obtained, then a voice channel connection is effected in operational block 904. Operational block 904 branches to conditional branch point 905 which tests if the call has been terminated. If the call is still in progress (a test result of NO), the operation branches to conditional branch point 905. If a test result of YES in step 905 is returned, conditional branch point 906 tests if DTMF blocking had been enabled as of call termination. If this test result is NO, the operation is exited via step 907. If the result of the test in step 906 is YES, DTMF blocking is disabled in operational block 908, and then operation is terminated via step 907.
As is shown in FIG. 9, if the conditional test of branch point 903 returns a YES (the calling party is a subscriber), the operation branches to operational block 1001 of FIG. 10. Operational block 1001 retrieves the service profile for the calling party, and branches to conditional branch point 1002 which tests to determine if the retrieved service profile calls for the enabling of DTMF blocking. If a test result of NO is returned, the operation branches to conditional branch point 1003. If the test result of YES is obtained in step 1002, DTMF blocking is enabled in operational block 1004, which branches to conditional branch point 1003. Conditional branch point 1003 tests to determine if the enabling DTMF trigger has been transmitted by the calling party. If the test result is YES, DTMF blocking is enabled in operational block 1005. If the test result is NO, conditional branch point 1006 tests to determine if the disabling DTMF trigger has been transmitted by the calling party. If the test result is YES, DTMF blocking is disabled in operational block 1007. If the test result in step 1008 is NO, the operation continues with conditional branch point 1008; operational blocks 1005 and 1007 also branch to conditional branch point 1008. Conditional branch point 1008 tests if a voice channel connection to the called party has been completed. If a call is in progress (a test result of YES), the operation branches to conditional branch point 1009. If the test result is NO, a voice channel connection to the called party is effected by operational block 1010, which branches to conditional branch point 1009. Conditional branch point 1009 determines if the call has been terminated. If the call is still in progress (a test result of NO), the operation branches to conditional branch point 1003. If a test result of YES is returned, the operation branches to conditional branch point 906 (FIG. 9)
FIGS. 11 and 12 illustrate the sequence of operations effected within network 600 in providing the controllable DTMF propagation limiting service described above to a called party. As shown in FIG. 11, the sequence is entered into via step 1101, and then conditional branch point 1102 tests to determine if the called party is a subscriber to the DTMF propagation limiting service. If a test result of NO is obtained, then conditional branch point 1103 tests if the call has been terminated. If the call is still in progress (a test result of NO), the operation branches to conditional branch point 1103. If a test result of YES is returned in step 1103, conditional branch point 1104 tests if DTMF blocking had been enabled as of call termination. If this test result is NO, the operation is exited via step 1105. If the result of the test in step 1104 is YES, DTMF blocking is disabled in operational block 1106, and then operation is terminated via step 1105.
As shown if FIG. 11, if the conditional test of branch point 1102 returns a YES (the called party is a subscriber), the operation branches to operational block 1201 of FIG. 12. Operational block 1201 retrieves the service profile for the called party from the ANI data base, and branches to conditional branch point 1202 which tests to determine if the retrieved service profile calls for the enabling of DTMF blocking. If a test result of NO is returned, the operation branches to conditional branch point 1203. If the test result of YES is obtained in step 1202, DTMF blocking is enabled in operational block 1204, which branches to conditional branch point 1203. Conditional branch point 1203 tests to determine if the enabling DTMF trigger has been transmitted by the called party. If the test result is YES, DTMF blocking is enabled in operational block 1205. If the test result is NO in step 1203, conditional branch point 1206 tests to determine if the disabling DTMF trigger has been transmitted by the called party. If the test result is YES, DTMF blocking is disabled in operational block 1207. If the test result is NO in step 1206, the operation continues with conditional branch point 1208; operational blocks 1205 and 1207 also branch to conditional branch point 1208. Conditional branch point 1208 tests if the call has been terminated. If the call is still in progress (a test result of NO), the operation branches to conditional branch point 1203. If a test result of YES is returned in step 1208, the operation branches to conditional branch point 1104 (FIG. 11)
The above-described invention provides a practical method for controllably controlling the propagation of DTMF signals within a network. It will be understood that the particular methods described are only illustrative of the principles of the present invention, and that various modifications could be made by those skilled in the art without departing from the scope and spirit of the present invention, which is limited only by the claims that follow.
One such modification would include situating the DTMF SDB associated with an originating or terminating switch on the egress side of the switch. This would allow the terminating switch to receive DTMF signals from a network user practicing the invention, while enabling DTMF signals to be blocked from reaching parties with whom the network user was connected to via the switch. A single DTMF SDB might also be modified to provide DTMF blocking for both the calling and called parties. Other modifications might involve incorporating the tone detection and blocking functions of the DTMF SDB within a switch, or performing these functions via a device adjunct to a switch, instead of via a device in-line with a switch. Still other modifications might include services wherein a verbal command serves as the audible prompt indicating to a network user that DTMF triggers may be keyed in.
Modifications of the manner in which an ANI data base is employed with the invention may also be envisioned. Systems could be programmed to alter the type of DTMF blocking provided to a subscriber based upon the number which the subscriber was calling, or based upon the number of the party calling the subscriber.
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A method for monitoring a network communications channel to detect specific DTMF triggers transmitted by a network user during either a pre-answer or a post-answer period of a call supported by the channel, and, in response to the detected DTMF triggers, controllably prohibiting the propagation of subsequent DTMF signals transmitted over the channel by the network user. Specifically, possible disruption of a communication between the network user and other parties caused by transmission of DTMF signals is eliminated by advantageously transmitting the DTMF triggers during the pre-answer period of a call. Furthermore, another deficiency of prior network-based arrangements for restricting the propagation of DTMF signals is overcome, as the invention may be practiced without the introduction of any significant propagation delay to a network.
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This invention relates to a valve device and method particularly, but not exclusively, for blocking the flow of fluid downhole in a casing string or liner string to enable the string above the tool to be tested for pressure integrity or to function tools located in the casing or liner string which are activated by pressure.
BACKGROUND OF THE INVENTION
When a borehole is drilled for hydrocarbon exploration, it is conventional to insert a casing string into the borehole to protect the borehole formation. A liner string can then be suspended within the casing string and can be connected to the top side by a drill string. Normally, cement is injected into the annulus between the outer surface of the casing string and the inner surface of the borehole in order to secure the casing string.
There are devices available that permit pressure testing of the casing string, or if present also permit pressure testing of the liner string, or which permit activation of pressure activated tools in the casing or liner string, the majority of these devices permitting pressure testing, or pressure activation respectively, after the cement has been inserted into the annulus.
However, in order to be able to pressure test the casing string after cementing, it is known to run in a packer tool. The packer tool comprises an outer expandable seal that when expanded seals against the inside of the casing string, which then permits pressure testing above the site of the seal. However, using such a packer tool can be detrimental to the casing string, as the packer tool exerts very high loads on casing when pressure testing, typically in the region of 10,000-15,000 psi. Further, the packer tool must be retrieved from the well after the testing operation has been completed.
Alternatively, a seat is provided at a suitable point on the inside of the casing or liner string so that when a plug is released, it travels down the casing or liner string and will hopefully land on the seat, thereby forming a seal so that pressure testing can occur above the plug. However, the plug and seat arrangement has the disadvantage that it is not certain that the plug will correctly land on the seat. The plug is normally released during the cementing operation and often does not land correctly on the seat, making it impossible to perform the pressure test. Further, the plug and seat pressure testing arrangement has the disadvantage that the cement is usually in position and has set or hardened by the time the pressure test is conducted. Therefore, if there is a leak in the system, the casing cannot be retrieved, resulting in expensive and time consuming remedial work to ensure pressure integrity.
Further, it has been known for the plug and seat pressure testing arrangement to fail during a pressure test. If this occurs, then the build up of high fluid pressure that precedes the failure can expel the cement from its intended location, and thus causes a poor cement job that requires remedial work.
If a packer, or the plug and seat arrangement is used after the cement has set, the high fluid pressure that is exerted on the casing can cause the metal casing to be bowed outward or expanded. This causes the cement to be displaced. Therefore, after the fluid pressure has been removed, the profile of relatively elastic metal casing will return to its original pre-pressure test state, but the cement may have set or hardened, and thus will not return to its original pre-pressure test state. Therefore, a micro-annulus may be formed between the outer diameter of the casing and the cement bond in the borehole, which may lead to gas migration up the borehole, and/or loss of zonal isolation.
In order to activate pressure operated tools located downhole, such as a conventional liner hanger system, or a conventional running tool for running a liner hanger system downhole, it is known to drop a ball down the casing string in the fluid path. The ball eventually lands on a ball seat located below the tool to be activated. Thus, the fluid path is blocked. This results in an increase in the fluid pressure, which can then activate the pressure operated tool. Then, when the pressure operated tool has been activated, the fluid pressure is increased such that the ball and/or the ball seat is sheared out of position, down the string. Fluid circulation can then continue in the same manner as before the ball was dropped.
However, there are various problems associated with this conventional apparatus and method for activating a pressure operated tool. The time taken for the ball to reach the ball seat can be considerable, and there can be problems with getting the ball to land on the ball seat, particularly in highly deviated wells such as horizontal wells, where the ball may have to travel a relatively long distance through a horizontal section of the well. Also, when the ball and/or the ball seat has been sheared out of position, the formation receives a hydraulic shock, which can lead to a loss of circulation of the fluid.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention there is provided a valve device for use downhole comprising a body member; a channel through the body member through which fluid can flow; a moveable member mounted within the body member, the moveable member comprising an obturating member for selectively obturating the channel, the moveable member being moveable between a first position in which the channel is not obturated and fluid flow through the channel is permitted, and a second position in which the channel is obturated and fluid flow through the channel is substantially prevented.
The invention has the advantage that by selectively blocking the fluid flow channel, the pressure of fluid above the blocking mechanism is increased, and pressure testing of the casing, or setting of pressure activated tools in either a casing string or liner string, above the blocking mechanism, can be achieved.
Optionally, the valve device further comprises a detachable locking device that locks the moveable member in the first position, until a displacement system is actuated to unlock the detachable locking device.
Preferably, a narrow channel section is located in the channel and is connected to the moveable member.
Preferably, a biassing device biasses the moveable member in a direction substantially opposite to the direction of flow of fluid.
Typically, the moveable member is moved by a pressure drop of fluid over the narrow channel section, the force of which overcomes the biassing of the biassing device.
Preferably, the movement of the moveable member is restrained by a restraining mechanism to a predetermined cycle of movement in a longitudinal direction with respect to the axis of the valve device and a rotational direction about the axis of the valve device. Typically, the restraining mechanism comprises a first member mounted on the body member and the second member mounted on the moveable member, the two members cooperating to restrain the movement of the moveable member to the predetermined cycle.
Preferably, one of the members is a male member and the other member is a female member, and more preferably, a slot is formed in the female member into which the male member seats, the slot defining the cycle of movement of the moveable member. Typically, the female member is a cylindrical member, and the slot is formed around the circumference of the cylinder and preferably the slot is a "J" slot.
Typically, the first member is the male member, and the second member is the female member. Preferably, the "J" slot comprises at least one short travel section slot and at least one long travel section slot, and more preferably, there are more short travel section slots than long travel section slots. Most preferably, the first position of the moveable member is whilst the moveable member cycle is in a short travel section slot, and the second position is whilst the moveable member cycle is at the furthest travel of the long travel section slot.
Typically, the displacement system comprises a drop-ball seat which is coupled to the moveable member, and a drop-ball such that when the drop ball lands on the drop-ball seat, the force of the fluid pressure upstream of the drop-ball seat unlocks the locking device, in use.
Typically, the detachable locking device includes at least one shear pin that extends from one of either of the body member or the moveable member, through to a shear pin hole located in the other of the body member or the moveable member.
The drop-ball seat may be selectively slidably coupled to the moveable member, such that before the detachable locking device is actuated, the drop-ball seat is locked to the moveable member, and after the detachable locking device is actuated, the drop-ball seat is slidably coupled to the moveable member.
Typically, after the detachable locking device is actuated, the drop-ball seat and drop ball move from a first drop-ball seat position, to a second drop-ball seat position. Typically, when the drop-ball seat is in the first drop-ball seat position, the drop-ball seat retains a detachable latching device mounted on the moveable member in a latching relationship with the body member. Typically, when the drop-ball seat is in the second drop-ball seat position, the drop-ball seat does not retain the detachable latching device, and the detachable latching device is permitted to detach from the latching relationship with the body member.
Optionally, the detachable latching device comprises at least one finger mounted on the moveable member which latches onto a latching shoulder mounted on the body member.
According to a second aspect of the present invention, there is provided a method of preventing the fluid flow downhole comprising the steps of inserting a downhole tool comprising a valve device of the first aspect of the present invention downhole; and moving the moveable member from the first to the second position such that the obturating member obturates the channel.
Optionally, the downhole tool is inserted into a collar where the collar is inserted into a casing or liner string.
The tool may be connected to the collar by a screw thread formation, or alternatively the tool may be connected to the collar by a screw thread formation and cement.
Alternatively, an outer member of the tool is provided with screw thread formations to permit the tool to be coupled into the casing string.
According to a third aspect of the present invention there is provided a method of re-establishing fluid flow downhole following a method of preventing fluid flow in accordance with the second aspect of the invention, the method of re-establishing fluid flow downhole comprising the steps of increasing or reducing the pressure of the fluid downhole to actuate a re-circulation means to re-establish fluid flow.
BRIEF DESCRIPTION OF THE DRAWINGS
An example of a valve device will now be described, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 is a half sectional side view of a first example of a downhole tool incorporating a valve device in accordance with the present invention;
FIG. 2 is a side view of continuous "J" slot sleeve, which is incorporated in the downhole tool of FIG. 1, laid out flat for greater clarity;
FIG. 3 is a sectional side view of a second example of tool incorporating a valve device in accordance with the present invention;
FIG. 4 is a side view of a continuous "J" slot sleeve, which is incorporated in the downhole tool of FIG. 3, laid out flat for greater clarity, and which is shown in engagement with a pin over a sequence of cycles;
FIG. 5 is a side view of a support ring, which is incorporated in a downhole tool of FIG. 3, laid out flat for greater clarity;
FIG. 6 is a cross-sectional view, across section A--A of FIG. 3, of a cylindrical sleeve, which is incorporated in the downhole tool of FIG. 3;
FIG. 7 is a cross-sectional view across section B--B of FIG. 3, of an inner lower body, which is incorporated in the downhole tool of FIG. 3; and
FIG. 8 is a sectional side view of a third example of a downhole tool incorporating a valve device in accordance with the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a downhole tool 1 incorporating a valve device comprising an outer body member 5, an inner lower body member 7 secured to the outer body member 5 by a screw threaded connection 29, and an inner piston 10. In between the outer body member 5 and the piston 10 is a channel 15 through which the fluid flows, with the direction of the fluid flow being indicated by arrows 20. Ports 9 are provided between the outer body member 5 and the inner lower body member 7 to provide for the channel 15 therebetween.
The piston 10 is slidably mounted within the body member 5 in a longitudinal direction of movement with respect to the longitudinal axis 50 of the body member 5, and a rotational direction about the longitudinal axis 50 of the body member 5. A valve 22 is mounted at the lower end of the piston 10.
The piston 10 is moveable between a first position (as depicted in FIG. 1) in which fluid can flow in the direction of arrows 20 from above the tool 1, through the channel 15, and out of the bottom of the tool 1, to a second position (not shown) in which an angled face 24 of the valve 22 makes contact with a correspondingly angled seat 32 of an inwardly facing shoulder 30 of the outer body member 5. When the piston 10 is in the second position, the fluid flow path as depicted by the arrows 20 is blocked, and accordingly the pressure of fluid above the valve 22 increases.
A cylindrical sleeve 35 is mounted around the outer circumference of a section of the piston 10. The cylindrical sleeve 35 has at least one narrow channel or port 37 running through the entire length of the sleeve 35, where the port 37 provides the fluid path as depicted by the arrows 20. However, a restriction nozzle or jet (not shown), such as a VISCO (™) jet may be mounted within the port 37 in order to further restrict the flow of fluid, as depicted by arrows 20, where necessary. A continuous "J" slot 39 is formed around the outer circumference of the cylindrical sleeve 35.
A male member or a key 41 projects inwardly from the outer body member 5, and seats in the continuous "J"slot 39. The continuous "J" slot 39 has two short travel positions 45a and 45b and one long travel position 47, the magnitude of travel being with respect to the travel of the piston 10 in a direction toward the shoulder 30 of the outer body member 5. The continuous "J" slot 39 is also formed in a manner such that the interaction between it and the key 41 permits the cylindrical sleeve 35 to only rotate about the longitudinal axis 50 of the tool 1 in one direction.
The piston 10 is biassed away from the shoulder 30 by a return spring 51.
The piston 10 can, optionally, be locked in the first position if required, by inserting a shear pin 61 into a pin hole (not shown) in the piston 10, and pushing the shear pin 61 through the pin hole until it lands in a shear pin seat (not shown) on the outer body member 5, at some time before the tool 1 is inserted downhole.
In operation of the tool 1, the tool 1 is inserted into the casing string (not shown), or the liner string (not shown), and is secured in either string by a collar (not shown) that connects with the tool 1 by a screw thread formation (not shown) between the collar and the tool 1, or a screw thread formation and cement (not shown). The tool 1 would normally be positioned close to or adjacent to the bottom of the casing string or liner string.
Optionally, the tool 1 can be run in downhole with the shear pin 61 inserted into the shear pin seat, and this allows fluid to flow through the tool 1 in the direction of arrows 20 until a drop-ball (not shown) is inserted into the fluid flow. The drop-ball is of such a dimension as to come to a rest when it reaches a ball seat 63 mounted within a collet 65 at the upstream end of the piston 10. The fluid pressure upstream of the drop-ball will build up until it reaches the breaking force of the shear pin 61. When the shear pin 61 breaks, the collet 65 is forced toward upper face of the piston 10 by the fluid pressure. Latching fingers 70 project in the opposite direction to the fluid flow to form the opposite end of the piston 10 with respect to the valve 22 end of the piston 10.
When the uppermost portion of the collet 65 clears the latching fingers 70, the latching fingers 70 are permitted to collapse sufficiently inwardly to clear upper shoulder 75 mounted on the outer body member 5.
The collet 65 and drop-ball continue travelling toward the upper face 69 until the collet 65 makes contact with the upper face 69. The collet 65 is restrained from travelling back toward fingers 70 by a one way snap ring 72 which allows the collet 65 to travel past it in the collet 65 direction of travel toward the upper face 69, but restrains the collet 65 from travelling back toward fingers 70.
Thereafter, the collet 65 and the drop-ball provide a further surface area upon which the fluid pressure can act. Therefore, the piston 10 and hence the valve 22 will move towards the shoulder 30. Thus, when the collet 65 clears slots 67 mounted in the piston 10, fluid flow will again be established through the tool 1 in the direction of arrows 20.
Alternatively, particularly to allow the casing string or liner string to be pressure integrity tested at various depths, or to activate pressure operated tools such as liner hanger systems, without raising the problems encountered by use of a drop ball, the tool 1 may be included in the string without the shear pins in place, in which case the cycling operation of the tool 1 is initiated solely by increasing the fluid flow. In this situation, the upper face 69 provides a further surface area upon which the fluid pressure can act. Also, the collet 65, and latching finger arrangement 70 can be omitted.
In either scenario, as the fluid flow through the tool 1 increases, a pressure drop is built up over the port 37 in the cylindrical sleeve 35 and this pressure drop will move the cylindrical sleeve 35 around its cycle due to the key 41 seating within the continuous "J" slot 39. Assuming that the key 41 first seats in the short travel position 45a which is shown in FIG. 2, the piston 10 will be restrained so that the valve 22 is spaced apart from the shoulder 30, and hence fluid flow can continue in the direction of arrows 20.
When the fluid flow through the tool 1 is cycled once, (that is the fluid flow velocity is decreased so that the biassing action of the return spring 51 overcomes the pressure drop over port 37 and the key moves into zero travel position 46a) and then the fluid flow velocity is increased so that the key 41 moves into the second short travel position 45b, then the tool 1 still allows fluid flow in the direction of arrows 20. However, if the fluid flow through the tool 1 is cycled again, the piston moves toward shoulder 30, the cylindrical sleeve 35 rotates so that the key passes the second 0 travel position 46b and lands in long travel position 47, then the valve 22 will contact shoulder 30, and fluid flow through the tool 1 will be blocked. In this situation, fluid pressure can be increased above the valve 22 so that the casing string, or liner string pressure integrity can be assessed, or activation of pressure operated tools can be achieved. Once the relevant operation has been completed, the pressure can be bled off, and the spring 51 moves the valve 22 away from the shoulder 30, and circulation of fluid is re-established.
It may be preferable to have a higher ratio of short travel positions 45a and 45b to long travel positions 47, so that the tool 1 only blocks off the fluid after many cycles of the fluid flow. The reason for this is that an operator would normally only want to block the fluid flow in order to either test the pressure integrity of the casing string or liner string, or activate pressure operated tools, after he has performed operations which require cycling of the fluid flow. However, it is difficult to increase the number of short travel positions in the continuous "J" slot 39 on the cylindrical sleeve 35, as the surface area of the cylindrical sleeve 35 is limited by the outside diameter of the tool 1 which may be approximately 6 inches. The inside diameter of the tool 1 at the point marked 100 is approximately 2 inches.
A second example of a downhole tool 100, is shown in FIG. 2, and which incorporates a valve device in accordance with the present invention. In many respects, it is similar to the valve device incorporated in the downhole tool 1 and where this is so, like reference numerals indicate the same components. The downhole tool 100 comprises an upper outer body member 5a which is screw threaded to the lower outer body member 5b, thus collectively forming the outer body member 5a, 5b. At the lower end of the lower outer body member 5b is a pin screw thread connection 110, which can be utilised to couple the tool 100 to a sub (not shown) located in the casing string (not shown). Therefore, in this situation, the tool 100 in use is situated in the bore of the casing string, but the pin connection 110 ensures that all fluid flowing through the casing string flows through the channel 15.
Alternatively, or in addition, the tool 100 can be provided with an upper screw threaded box connection (not shown), such that the tool 100 could then replace a section of casing tubing in the casing string.
In addition to the common features that the tool 100 has with the tool 1, the tool 100 also has a lower piston section 125 which is mounted to the lower portion of the cylindrical sleeve 35. The inner surface of the lower piston section 125 is waisted inwardly toward the radially outer surface of the piston 10, and similarly the radially outer surface of the piston 10 which is aligned with the lower piston section 125 is waisted outwardly toward the lower piston section 125. This creates a very narrow channel section 130 which increases the pressure drop created, in addition to that created by the port 37. Upper 137 and lower 135 O-ring seals ensure that fluid is restrained from entering the slot 39. A support ring 120 is mounted between the upper 5a and lower 5b outer body members, and has an upper 121 and a lower 122 face which respectively butt against the lower end of the cylindrical sleeve 35 and the lower end of the lower piston section 125, when the key 41 is at the respective extremities of its travels through the slot 39. The support ring 120 therefore bears the load of the piston 10, rather than the key 41.
FIG. 8 shows a third example of a downhole tool 150, which is broadly similar to the downhole tool 100 with like components being indicated with the same reference numerals. However, FIG. 8 shows the downhole tool 150 with the piston 10 in the second position, that is with the fluid path being blocked due to the contact between the valve 22 and the angled seat 32, subsequent to a dropped ball (shown in phantom) having being dropped down the casing string. The downhole tool 150 can be incorporated into the casing string in the same manner as the downhole tool 100, if required.
However, in addition to the components of the downhole tool 100, the downhole tool 150 has apertures 160 which lead to a fluid chamber 165. At the lower end of the fluid chamber 165 is an O-ring seal 166. Another difference is that the inner lower body member 7 is releasably secured to the lower outer body member 5B by a shear circlip 153.
Accordingly, if the downhole tool 150 reaches the second position shown in FIG. 8, and for some reason cannot move back to the first position to re-establish circulation of fluid, or it is wished to disable the tool 150 from further operation, then by further increasing the pressure above the valve 22, this increased fluid pressure will act on the lower inner body member 7 above the O-ring 166 until the breaking force of the shear circlip 153 has been reached. Therefore, the lower inner body member 7 will rapidly be ejected from the downhole tool 150 and circulation of fluid through the downhole tool 150 is re-established, albeit through the alternative fluid path 160, 165.
Therefore, the downhole tool 150 provides a means of re-establishing circulation through the casing string by further increasing the pressure of the fluid.
Alternative means for re-establishing the circulation through the casing string include providing conventional rupture or bursting discs, or a stage cementing collar located in the casing string at a point above the angled seat 32 of the inwardly facing shoulder 30, for any of the tools 1, 100, 150. Alternatively, a stopper plug could be shear pinned into the side wall of the casing above the angled seat 32 of the inwardly facing shoulder 30, such that when the fluid pressure reaches the breaking force of the shear pins, the stopper plug is ejected from the casing wall and the circulation path for the fluid is re-established. Alternatively, and if desired the pressure can be bled off as described before, and the spring 51 moves the valve 22 away from the shoulder 30, and circulation of fluid is re-established.
Alternatively, by arranging or adapting the key 41 and slot, the circulation of fluid can be re-established by means of the inner components being ejected from the tool 1, 100, 150 when the pressure of the fluid is bled off. For instance, a long travel position with an opening (not shown) to the upper surface of the cylindrical sleeve 35 could be provided, such that when the key 41 enters, and leaves, the open topped long travel position, the slot 39 no longer engages the key 41.
It should be noted that the slot 39 of the tools 1, 100, 150, could be a discontinuous slot (not shown) which could be arranged by, for example, having a short travel position at its end. Thus, when the various cycles of the fluid flow through the tools 1, 100, 150 have been completed, the valve 22 is spaced apart from the shoulder 30 and thus circulation of fluid at the end of the cycles is virtually ensured. This feature would be advantageous to virtually remove the possibility of the tools 1, 100, 150 closing during the cementing operation.
As a back-up feature, particularly when operating a liner hanger system, a prior art drop ball device as described in the introduction, may be provided above the tool 1, 100, 150 to ensure that it is possible to activate pressure operated tools.
The tools 1, 100, 150 may also be utilised to activate pressure operated liner hanging systems that attach liner strings to the bottom of casing strings. Liner hanger systems normally attach to the bottom of casing strings by a tool similar in concept to a packer, and which are activated by fluid pressure, typically in the region of 1500 p.s.i. The advantage of using the tools 1, 100 and 150 of the present invention in order to activate the hydraulic cylinders of liner hanger systems is that hydraulic shock on the liner hanger system and the geological formation will be reduced.
The inner components of the tool 1, 100, 150 at least, are optionally formed from a material that is drillable, such as an alloy which may comprise mainly aluminium, to allow the inner components, at least, of the tool 1, 100, 150 to be removed from the casing string or liner string by drilling through the tool 1, 100, 150 in the conventional drilling manner by normal drill bit sizes, if the well is to be deepened.
It will be possible to use the tools 1, 100 and 150 in conjunction with a conventional plug and seat cementing arrangement if the seat is located above the tool 1, 100 or 150 and does not interfere with the fluid flow required to activate the tool 1, 100 or 150. This would have the advantage that the plugs can still be utilised for indicating when the cement has reached its intended destination, if the plug is placed into the borehole immediately trailing the cement, since the seating of the plug and the resultant stop in fluid flow and increase in fluid pressure indicates to the operator that the cement is in place.
The tools 1, 100, 150 may be located adjacent to, or above the bottom of the casing string, in order to control the circulation of fluid, particularly cement, through and out of the casing string into the borehole.
Optionally, for setting a liner hanger system, a small bleed path (not shown) can be formed on the face of either the valve 22 or the angled seat 32, or in an appropriate place, which provides for sufficient bleed off of the pressured fluid above the valve 22, to permit the valve 22 to open but insufficient to prevent the liner hanger system from being set.
Modifications and improvements may be made to the embodiments without departing from the scope of the present invention.
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A valve device for use downhole is described as comprising a body member and a channel through the body member through which fluid can flow. A moveable member is mounted within the body member, and comprises an obturating member for selectively obturating the channel. The moveable member is moveable between a first position in which the channel is not obturated and fluid flow through the channel is permitted, and a second position in which the channel is obturated and fluid flow through the channel is substantially prevented.
A method of preventing the fluid flow downhole is also described as comprising the steps of inserting a downhole tool comprising a valve device according to the present invention downhole and moving the moveable member from the first to the second position such that the obturating member obturates the channel.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of drilling operations, in particular deep offshore and very deep offshore drilling. These operations generate increasingly complex technical problems considering the extreme conditions encountered at such water depths. It is for example possible to observe temperatures close to 0° C. and pressures close to 400 bars at the water bottom (mud line). As a consequence, the drilling fluid circulating in the well, subjected to these conditions, must keep its properties within a very wide temperature range, for example between 0° C. and 200° C.
[0002] The above-mentioned bottomhole temperature and pressure conditions are particularly favourable to the formation of gas hydrates. Gas hydrates are solid structures containing water and gas. The water contained in the drilling fluids forms, under certain temperature and pressure conditions that essentially depend on the composition of the aqueous phase, a solid cage which traps the gas molecules. Formation of these solid gas hydrates can have particularly serious consequences as a result of the agglomeration and deposition of hydrate crystals that may eventually clog the wellhead, the auxiliary control lines and the annulus.
[0003] The loss of the rheological properties of the mud (due to the breaking of the water-in-oil emulsion by the hydrate crystals in the case of inverted oil-emulsion muds, and to the growth of the crystals in the case of water-base muds) can lead to an interruption of the drilling operations or even to the loss of the well, not to mention the safety problems linked with the dissociation of the hydrates formed (high-velocity propulsion of solid hydrate slugs). Furthermore, during mud backflow to the surface, large amounts of gas can be released at the surface.
BACKGROUND OF THE INVENTION
[0004] The operational solutions conventionally used by operators consist in using water-base or oil-base muds comprising thermodynamic hydrate formation inhibitors. The most commonly used inhibitors are salts and glycols, used in high proportions (conventionally 20 to 30% salt concentrations), which entails considerable corrosion and toxicity or logistic problems.
[0005] Determination of the pressure/temperature zones where gas hydrates are likely to form in the drilling mud (thermodynamic conditions of use) is currently based on tests carried out in reactors on aqueous solutions (simplified or model formulations) or on thermodynamic models validated from PVT cell experiments on simple or model fluids. The action of inhibitor additives is generally tested on model hydrates (THF or freon) allowing to work safely at the atmospheric pressure.
[0006] At the present time, there is no simple, fast and reliable method for determining the conditions of gas hydrate formation in drilling fluids that could be directly applicable in the field, at temperatures close to 0° C. and under natural gas pressure. The importance of working on real muds, i.e. mud samples taken at the surface, is particularly linked with the influence of the constituents, notably the solids, whose action on the formation of hydrates cannot be quantified a priori.
[0007] The existing techniques for determining the hydrate dissociation points in drilling muds use measurements in PVT cells or in reactors, and they follow the gas consumption and the pressure variation (at constant volume). The drawbacks of these techniques are linked with the implementation weightiness (long experiment time) and with the difficulty in working with complex fluids, particularly those containing solids.
[0008] Practically any physico-chemical phenomenon characterized by an enthalpy change (chemical reaction, transition, fusion . . . ) can be characterized by DSC (Differential Scanning Calorimetry). However, application of this technique to the characterization of hydrates has been limited to model hydrates that can form at atmospheric pressure.
[0009] Handa's published work (Handa, Y. P., (1986a), Compositions, entbalpies of dissociation and heat capacities in the range 85 to 270 K for clathrate hydrates of methane, ethane, propane, and enthalpy of dissociation of isobutane hydrate, as determined by a heat-flow calorimeter, J. Chem. Thermodynamics, 18, 915-921. Handa, Y. P., (1986b), Calorimetric studies of laboratory synthesized and naturally occuring gas hydrates, in Proc. AIChE Annual Meeting, Miami Beach, Nov. 2-7, Handa, Y. P., (1988), A calorimetric study of naturally occuring gas hydrates, Ind. Eng. Chem. Res., 27, 872-874) is well-known. He has developed a calorimetric technique for determining the compositions, enthalpies of dissociation and specific heats of xenon, krypton, methane, propane, ethane and isobutane hydrates, as well as natural gas hydrate samples. He has used, for this study, a SETARAM BT Calvet type calorimeter allowing to work on samples of several grams, which of course reduces the usable temperature scanning speed range (because of thermal transfer problems in the sample), but allows very precise enthalpy and thermal property measurements.
[0010] Koh et al. (1998) of King's College in London (Koh, C. A., Westacott, R. E., Hirachand, K., Zugic, M., Zhang, W., Savidge, J. L., (1998), Low dosage natural gas hydrate inhibitor evaluation, in Proc. 1998 Intern. Gas Research Conference, San Diego, USA, November 8-11, Vol.I, 194-200) have recently used the DSC technique to test hydrate inhibitors. Since their device does not work under pressure, they have studied model THF hydrates that form at atmospheric pressure. They used cooling and temperature scanning to determine the supercooling degrees according to the inhibitor type and also carried out studies under isothermal conditions after fast quenching of the sample to observe the crystallization of the THF hydrates as a function of time. They have thus been able to draw curves referred to as THF (time-temperature-transformation) curves which allow to compare the kinetic effect of the inhibitors on the formation of hydrates.
[0011] Fouconnier et al. (1999), of the University of Compiègne (Fouconnier, B., Legrand, V., Komunjer, L., Clausse, D., Bergflodt, L., Sjöblom, J., (1999), Formation of trichlorofluoromethane hydrate in w/o emulsions studied by DSC, Progr. Colloid Polym. Sci., 112, 105-108) have used the DSC technique at atmospheric pressure to study the formation of model trichlorofluoromethane hydrates in water-in-oil emulsions stabilized by Berol 26. The formation of hydrates has been observed by means of the DSC technique with temperature scanning.
SUMMARY OF THE INVENTION
[0012] The object of the present invention is to have, on a drilling site (in mud logging and monitoring cabs), a device for determining risks of hydrate formation on a real well fluid, by measuring the hydrate dissociation temperature at a given gas pressure, according to the DSC (Differential Scanning Calorimetry) technique. These measurements allow the operator to predict dangerous zones with hydrate formation Pressure/Temperature conditions, and therefore to select the mud that is best suited to the current or future drilling conditions, or even to carry out in-situ tests on hydrate inhibitor additives under conditions that are very close to the real conditions. In the case of oil-base muds, which are inverted water-in-oil emulsions, it is also possible to determine whether hydrate formation is likely to break the emulsion, in which case the fluid loses its rheological properties. The combined use of a software allowing to determine the thermal profile in the mud during drilling allows the risks of hydrate formation during the operation to be precisely determined.
[0013] The present invention thus relates to a method for determining the gas hydrate formation conditions in a well fluid, said method comprising the following stages:
[0014] taking a fluid sample,
[0015] placing this sample in a calorimetry cell,
[0016] performing on this sample a reference thermogram in a temperature range between T1 and T2,
[0017] performing on the same sample a second thermogram in the same range and under a pressure Ph of a hydrocarbon gas, T1 being a temperature low enough to obtain the formation of hydrates in the sample at a gas pressure Ph, P2 being high enough to obtain hydrate dissociation,
[0018] identifying a peak in the second thermogram corresponding to the hydrates dissociation zone and deducing therefrom a hydrates dissociation temperature,
[0019] determining the hydrate formation conditions for the fluid considered.
[0020] In a variant, pressure Ph can be determined as a function of the pressure of the well fluid close to the zones where the appearance of hydrates is critical.
[0021] The efficiency of anti-hydrate additives can be tested by adding them to said fluid sample in determined proportions.
[0022] T1 and T2 can be −20° C. and 35° C. respectively.
[0023] The measurements allowing to obtain the thermograms can be performed according to a scanning temperature gradient ranging between 0.5 and 5° C./minute, preferably 2° C./minute.
[0024] CH4 can be used for the sample saturation gas.
[0025] The present invention also relates to a system for implementing the method, characterized in that it comprises in combination: a calorimetric measuring device, means for placing the measuring cell of said device under pressure by means of a hydrocarbon gas, thermogram recording means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Other features and advantages of the present invention will be clear from reading the description hereafter of non limitative examples, with reference to the accompanying drawings wherein:
[0027] [0027]FIG. 1 illustrates the principle of the measuring cell of the device,
[0028] [0028]FIG. 2 illustrates the flowsheet of the device,
[0029] [0029]FIGS. 3 a and 3 b show examples of determination of the hydrates dissociation temperature,
[0030] [0030]FIGS. 4 and 5 show two thermograms obtained on two drilling mud samples.
DETAILED DESCRIPTION
[0031] DSC (Differential Scanning Calorimetry) or DEA (Differential Enthalpy Analysis) is a technique allowing to measure heat exchanges between a sample and a reference as a function of the temperature or of time. The record obtained from these measurements is referred to as thermogram There are several types of DSC devices which are commercially available. They work according to the principle described hereafter.
[0032] [0032]FIG. 1 diagrammatically shows a measuring device 1 wherein a fluid sample S is contained in a cup 2 that can be open or sealed and placed under pressure by means of a determined gas, according to the experimental conditions. A second cup (not shown), similar to the first one, can contain a reference sample or it can be left empty. Cups 2 are placed each in a shaft of oven 3 comprising thermostatic means allowing a temperature program to be applied. The various existing devices mainly differ in the thermal exchange measuring principle. In the simplest devices, a thermocouple is used to measure the temperature difference between the two cups at a point of the wall thereof (the bottom generally). The heat flow is deduced from this temperature difference by calibration.
[0033] More complex DSC devices use the Calvet principle to measure the heat exchanges very precisely. The principle of the device is diagrammatically shown in FIG. 1. The two cylindrical cups 2 are placed in two independent detectors 4 consisting of a series of thermocouples surrounding the cup. Each thermocouple measures the temperature difference between the cup and the oven, in the radial direction. This temperature difference is linked with the local heat flow dq ii /dt exchanged between the cup and the oven by:
e i = ɛ λ q i t ( 1 )
[0034] where e i is the electric force released by couple i, ε its thermoelectric constant and λ the thermal conductivity of the material of the detector. All the couples are connected in such a way that the detector releases a total electric force E linked with the global thermal exchange dQ/dt by:
E = ∑ i e i = ∑ i ɛ λ q i t = ɛ λ Q t ( 2 )
[0035] The differential measurement is performed by connecting the detectors of the reference and of the sample in opposition. The exact relation between the heat flow and the electric power recorded is obtained by calibration.
[0036] The base equation of this technique is as follows:
h t = q t + ( C e - C r ) T p t + RC e 2 q t é ( 3 )
[0037] dh/dt=heat released or absorbed by the sample (W)
[0038] dq/dt=power recorded by the calorimeter (W)
[0039] C e =heat-capacity rate of the sample (J/K)
[0040] C r =heat-capacity rate of the reference (J/K)
[0041] T p =temperature of the thermostatic block (K)
[0042] t=time (s)
[0043] R=thermal resistance (K/W).
[0044] The heat released by the sample is thus the sum of three terms: the first one represents the power recorded by the calorimeter, the second expresses the difference between the base line and the zero level of the signal, due to the specific heat differences between the sample and the reference, and the third represents the transient phenomena linked with the heat exchanges between the sample and the thermostatic block, R being the thermal resistance between the sample and the oven and RC e being the time constant of the cell containing the product. The heat released or absorbed by the sample is therefore directly linked with the power recorded by the calorimeter. A single calibration point therefore allows quantitative use of the thermograms throughout the temperature range available with the device.
[0045] The DSC technique can be used for three application types (Claudy, P., (1999), Analyse Calorimétrique Différentielle (DSC)—Application à la chimie. L'Actualité Chimique, Mars 1999, 13-22):
[0046] Thermodynamic: measurement of specific heats, transitions (transitions of the first order, fusion, crystallization, electric and magnetic transformations, glass transition . . . ), purity determination, study of disperse phases (thermoporosimetry, emulsions . . . );
[0047] Kinetic: various types of measurements can be performed from the relation between temperature, time and the degree of progress of a reaction (isothermal studies, kinetic measurements at constant or variable scanning speed). The order of a reaction and the activation energy can thus be determined;
[0048] Analytic: the calorimetric signal can be linked, in many cases, with the transformation of a particular compound. Measurement of the corresponding energy allows to determine the mass of the compound. The DSC technique is used for example to characterize silica in cements, polymorphous forms in pharmacy, various polymer forms, and it can also be readily applied to characterization of complex fluids such as gas oils, bitumen and crude oils.
[0049] The base line is the thermogram obtained in the absence of any thermal phenomenon. The shape of this base line entirely depends on the evolution of the heat-capacity rate of the cell containing the sample. In cases where a thermal phenomenon is accompanied by a specific heat variation of the sample, there will be a difference between the base lines obtained before and after the phenomenon considered.
[0050] Measurement of the area of the signal allows to directly return to the total heat involved during the thermal phenomenon. Study of the fusion of pure bodies whose specific fusion enthalpy is precisely known allows the calorimeter to be calibrated.
[0051] Unlike differential thermal analysis, the temperatures are not directly obtained with the DSC technique. Temperature calibration is carried out from the study of the fusion of pure bodies. The difference between the temperature of the sample T e and the programmed temperature T p is linked with the heating rate, the heat flow dQ/dt and the thermal properties of the cup and of the detector according to the following equation:
T p - T e = RC e T p t - R Q t ( 4 )
[0052] The gas hydrate dissociation temperature is determined as described hereafter. A calorimeter suited for work under controlled atmosphere and under pressure is preferably used, for example calorimeter DSC 111 marketed by the SETARAM company (France), equipped with controlled-pressure cells. In FIG. 1, reference number 5 represents the junction with means for placing the sample under pressure by means of a hydrocarbon gas. Reference number 6 is a junction with well and cell sweeping means using an inert gas, nitrogen for example. This calorimeter is based on the Calvet principle described above and it is one of the most accurate devices. The oven can be readily cooled down to −120° C. by circulation of cold gaseous nitrogen.
[0053] [0053]FIG. 2 is the flowsheet of the device. DSC device 10 receives the two cells: M contains the sample to be tested and R contains the reference sample. In the present case, the reference cell is empty. A gas pressure is applied to the reference and measuring cells by means of a pressure control board 11 mainly consisting of a 0.4-liter surge drum 12 to compensate for all the pressure variations due to the consumption (or to the release) of gas during the formation (or the dissociation) of hydrates. The pressure is measured with a 0-100 bar precision pressure gage 13 having a 1-bar resolution. Each controlled-pressure cell consists of a cylindrical steel cup with a capacity of 0.27 ml, connected at each end to a thin steel tube ended by a connection, and sealed at the other end by a steel cap with an aluminium joint. Once positioned in the DSC detector, the cup is arranged exactly in the zone sensitive to heat flows, whereas the connection is outside the oven. Another connection is used for nitrogen sweeping during the analysis, in order to prevent condensation of the water at low temperature. The cup used as the reference cup is empty. 20 to 50 mg of the sample is fed into the measuring cup by means of a syringe.
[0054] The sample is first analysed at atmospheric pressure or under neutral gas pressure so as to obtain a <<blank>> or <<reference>> thermogram comprising all the thermal signals that cannot be imputed to the hydrates. The same analysis is then carried out under hydrocarbon gas pressure, a natural gas or other, the sample being cooled to a temperature that is low enough for the hydrate to form rapidly; the temperature has to be all the lower as the pressure is low. A cooling system using liquid nitrogen, shown by reference number 14 in FIG. 2, is for example used. The sample is then heated at a rate ranging between 0.5 and 5° C./min, preferably 2° C./min, to a temperature close to the ambient temperature (between 25 and 35° C.). The appearance of a peak in the zone where the record of the reference thermogram comprises none corresponds to the formation of hydrates. When in doubt (appearance of peaks in different zones), the test pressure can be varied, and the peak corresponding to the hydrates will then shift to temperatures that are all the higher as the pressure increases.
[0055] [0055]FIGS. 3 a and 3 b illustrate the determination of the hydrate dissociation temperature advantageously using calorimetric analysis techniques by identification of the thermal signal onset temperature T f which corresponds to the intersection between tangent 20 to the greatest slope of peak 21 and base line 22 (FIG. 3 a ). In the case of complex fluids (such as water-in-oil emulsions like oil-base muds), the peak may not be clearly defined. In this case, temperature T s corresponding to the vertex of peak 23 is preferably determined (FIG. 3 b ).
[0056] In the case of applications to a drilling site, in a mud logging cab for example, this type of calorimeter has to be made ADF. The cells are suited to withstand pressures close to 400 bars (extreme conditions encountered in deep offshore drilling) in order to perform measurements under conditions that are as close to reality as possible. These cells can be closed cells or gas-swept cells. The advantage of sweeping is to provide better diffusion of the gas in the sample by means of the agitation due to bubbling. It is therefore necessary to have a gas compression system to work at pressures above 150 bars.
[0057] The procedure consists in taking a well fluid sample from the mud backflow and to feed it into the measuring cell by means of a syringe (between 20 and 50 mg). The initial temperature of the calorimeter is preferably programmed at −20° C. at the most. Isotherm conditions are then established to ensure that equilibrium is reached, for example for 15 minutes at −20° C. A first temperature scan is carried out up to 20 to 30° C. under neutral gas (nitrogen) pressure or at the atmospheric pressure so as to obtain the reference thermogram. The scanning speed ranges between 0.5 and 5° C./min, preferably 2° C./min. The extreme pressure conditions encountered in the sensitive zone where hydrates are likely to form are recorded. After return to the initial temperature (−20° C. for example), the cells are placed under the hydrocarbon gas (natural gas or other) pressure representative of the conditions of the site (maximum 400 bars). The same analysis is repeated with temperature scanning, at the same heating rate, but under natural gas controlled pressure. The appearance of a peak in the zone where the reference thermogram comprises none is linked with the hydrate dissociation. The dissociation temperature is determined according to the technique described above (according to the peak type, onset temperature T f or vertex temperature T s ).
[0058] This procedure can be repeated at several different pressures according to the pressures representative of the site. The combined use of a predictive software for determining the thermal profile in the mud during drilling allows to precisely determine the time of the drilling operation when there is a risk of hydrate appearance in the circulating well fluid.
EXAMPLES
[0059] Determination of the methane hydrates dissociation temperature on an oil-base mud without weighting material at 75 bars (FIG. 4), the hydrate peak 30 is observed at about −1° C.; it is also possible to see a peak 31 at about −32° C., which corresponds to the melting of the ice contained in the water droplets.
[0060] Determination of the methane hydrates dissociation temperature on a complete oil-base mud at 65 bars (FIG. 5), the hydrate peak 32 is observed at about −5° C.; it is also possible to see a great peak 33 at about −32° C. which also corresponds to the melting of the ice contained in the water droplets.
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Method of determining the gas hydrate formation conditions in a well fluid, comprising the following stages:
taking a fluid sample,
placing this sample in a calorimetry cell,
performing on this sample a reference thermogram in a temperature range between T1 and T2,
performing on the same sample a second thermogram in the same range and under a pressure Ph of a hydrocarbon gas, T1 being a temperature low enough to obtain the formation of hydrates in the sample at a gas pressure Ph, P2 being high enough to obtain hydrate dissociation,
identifying a peak in the second thermogram corresponding to the hydrates dissociation zone and deducing therefrom a hydrates dissociation temperature.
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This application is a division of application Ser. No. 159,741, filed June 16, 1980, now U.S. Pat. No. 4,373,032, issued Feb. 8, 1983.
BACKGROUND OF THE INVENTION
In the Journal of Polymer Science: Polymer Letters Edition, Volume 16 of 1978, pages 607-614 G. N. Patel et al. describe polymers of certain alpha, omega diacetylene bis(butoxycarbonylmethyl urethanes) and analogous ethoxy compounds; which, unlike theretofore known polydiacetylenic compounds, are substantially soluble in certain common organic solvents. Such solutions are remarkable in showing dramatic color changes when a nonsolvent is added.
SUMMARY OF THE INVENTION
This invention relates to water-soluble polyacetylenic polymers, which are alkali metal salts, or the corresponding acids, derived from the above-mentioned polyacetylenic polymers and from related polymers; and to the alkali metal salts or acids of the corresponding monomers. The water-soluble polyacetylenic polymers of the invention are useful for detection and removal of certain metal ions from aqueous solutions; and the monomers and polymers can be used in time/temperature indicating devices wherein the monomer is activated by conversion to acid form to undergo a change in color or shade by contact with a reagent; or the polymer in acid form undergoes a color change when converted to the salt form by a reagent such as an aqueous alkali permeating a microporous membrane, separating said polymer and said reagent, at a rate which varies with temperature.
The polymers of the invention are polyacetylenes of the group corresponding to the monomeric formula [R(C.tbd.C) a (CH 2 ) b (C.tbd.C) b-1 ] 2 , a being 1 or 2, and b being 0 when a is 1 and b being 0, 1 or 2 when a is 2 and (b-1) being taken as zero whenever b is zero; wherein R is selected from the group consisting of (I); --(CH 2 ) n O(C.tbd.O)NHCH 2 CO 2 M', n being an integer from 1 to 10 and M representing an alkali metal or hydrogen; and (II); --(CH 2 ) n' CO 2 M', n' being an integer from 0 to 9 and M' being an alkali metal.
More especially polymers of the invention conform to the formulas above wherein a is 1, b and (b-1) are zero, and R is of formula I wherein n is 3 or 4; and more especially such polymers wherein M is potassium or sodium.
For applications such as removal of metal ions from aqueous solution, the polymer salt of the invention can be a cross-linked or a noncrosslinked polymer. Such polymer exchanges its alkali metal ion for ions of other metals in aqueous solution whereupon the salt of said polymer with such other metal precipitates from said aqueous solution.
DETAILED DESCRIPTION
The reactions were carried out in the laboratory in 1 L glass 3-necked flasks fitted with a mechanical stirrer, thermometer, an addition funnel, and an inlet and an outlet tube to allow blanketing the system with nitrogen or admitting a stream of oxygen.
The diols were prepared by oxidatively coupling the appropriate mono-ols using the Hay method (J. Pol. Sci, vol. 7 of 1960 pg. 1625). Briefly, to a solution consisting of 350 mL methanol, 6 g cuprous chloride, and 12 mL N,N,N',N'-tetramethylethylenediamine (TMEDA), a solution composed of 100 g mono-ol mixed with 50 mL methanol was added dropwise for a period of 0.75 to 1.0 h. Oxygen was bubbled into the reaction medium at a moderate rate throughout the duration of the run; between 8 and 16 h. were ample. Afterwards the solvent was stripped and the residue acidified with 5N hydrochloric acid. The diol was extracted with diethylether, washed with water, neutralized with sodium bicarbonate, dried with anhydrous magnesium sulfate, then stripped of its solvent. Crystallization of the product was obtained by extracting the viscous residue with a 4:1 combination of xylene and heptane followed by refrigeration. The solid that formed was filtered and the recrystallization repeated (a mixture of diethyl ether and petroleum ether may be used for the dodecadiyn diol). Conversions to the diols were usually in excess of 80%.
The 4,6-decadiyn-1,10-diol is a white fluffy solid that changes to blue in daylight; M.P. 44.8°-45.7° C. The 5,7-dodecadiyn-1,12-diol is a white particulate solid, unreactive to U.V. radiation; M.P. 50.1°-50.7° C.
Conversion of diols to diacids was accomplished using chromic acid solution as an oxidizer, prepared by mixing 35 g CrO 3 with 175 mL water and while stirring the solution in an ice-bath, adding incrementally 56 g concentrated sulfuric acid so as to minimize the exothermic reaction due to the heat of mixing.
The various product melting points (uncorrected) were obtained on a hot-stage melting point apparatus, observed through a microscope.
The IR spectra were recorded on a spectrophotometer by forming KBr pellets of the products.
Microanalytic techniques were used for the elemental analyses.
EXAMPLE 1
SYNTHESIS OF 4,6-DECADIYN-1,10-DIOIC ACID [HOCO(CH 2 ) 2 C.tbd.C] 2
To a solution of 16.6 g (0.1 mol) 4,6-decadiyn-1,10-diol and 175 mL acetone, chromic acid was added dropwise over a period of 0.75 h. The temperature was maintained between 15° and 25° C. using a solid CO 2 /acetone bath. (Caution: care must be exercised to avoid an extreme exotherm during the addition). After 0.25 h. the bath was removed and the reactants allowed to react for an additional 3 h.
The solution was extracted 3 times with diethylether using 150 mL each time. The combined extract was condensed to 300 mL and 150 mL 2.5N NaOH was added while stirring to form the disodium salt. The aqueous layer was separated and saved. The ether layer was extracted with 100 mL water which was combined with the previous aqueous layer. The aqueous phase was then back extracted with three portions, 50 mL each, of diethylether. The aqueous portion was chilled in a cold water bath and neutralized by slowly adding a 5N hydrochloric acid solution to regenerate the diacid; the end-point being noted by product precipitation. The product was recrystallized by dissolving in 200 mL hot ethylacetate followed by 75 mL xylene and refrigeration at -26° C.
After crystallization the product was filtered, washed with xylene followed by petroleum ether (60°-110°) and vacuum dried. Yield; 7.5 g of white solid which turns red slowly under U.V. light. Decomposes, 225°-230° C.
Elemental Analysis: Calcd. for C 10 H 10 O 4 : C, 61.85; H, 5.19, O, 32.96. Found: C, 61.67, H, 4.95; O, 33.21.
IR Analysis: (bonded OH of the acid), 3,300 and 2,500; (C.tbd.C), 2,240(w); (carbonyl) 1,700(s); (C--O stretch), 1,300(s) and 1,200 cm -1 .
EXAMPLE 2
SYNTHESIS OF 5,7-DODECADIYN-1,12-DIOIC ACID [HOCO(CH 2 ) 3 C.tbd.C] 2
The same general procedure was followed except that 19.4 g (0.1 mol) 5,7-dodecadiyn-1,12-diol was used as the starting material.
The diacid product was recrystallized by dissolution in 200 mL diethylether followed by separation to segregate the residual water present, and addition of 300 mL petroleum ether (60°-110°) to precipitate the product. The product was filtered, washed several times with petroleum ether and dried. Yield: 17.5 g of pink powdery solid. Decomposes, 225°-230° C. The product was both U.V. and thermally active; noted by its turning red at a moderate rate in daylight and at a slower rate when protected from light sources even when refrigerated.
ANALYSIS:
Elemental: Calcd. for C 12 H 14 O 4 : C, 64.85; H, 6.35; O. 28.80. Found: C, 66.02; H, 6.62; O, 27.45.
IR: (bonded-OH of the acid), 3,200 and 2,500; (C.tbd.C), 2,240 (w); (carbonyl), 1,700(s); (--(CH 2 ) 3 ), 1,458; (C--O) stretch), 1,270 and 1,210 cm -1 .
EXAMPLE 3
(A)
SYNTHESIS OF 4,6-DECADIYN-1,10-BIS(BUTOXYCARBONYLMETHYL URETHANE)
To a solution of 20.0 g (0.12 mol) 4,6-decadiyn-1,10-diol, 250 mL tetrahydrofuran (THF), and 0.2 g dibutyltin-di-2-ethylhexanoate dissolved in 4 mL triethylamine, a solution consisting of 56.6 g (0.36 mol) butyl isocyanatoacetate (C 4 H 9 OCOCH 2 NCO) dissolved in 50 mL THF was added dropwise over a period of 0.5 h. After 3 hours the product, having formula [C 4 H 9 OCOCH 2 NHCOO(CH 2 ) 3 C.tbd.C--] 2 , was precipitated with heptane and recrystallized in 700 mL isopropyl ether. Yield: 51.0 g (90.4% of theoretical) of white fluffy solid which turns blue slowly. M.P. 64.2°-64.7° C.
(B) SYNTHESIS OF 4,6-DECADIYN-1,10-BIS(CARBOXYMETHYL URETHANE)
24.0 g (0.05 mol) of the above 4,6-decadiyn-1,10-bis(butoxycarbonylmethyl urethane) was converted to its dipotassium salt in aqueous solution by adding it incrementally to 250 mL of a 1.25N KOH solution consisting of a 1:1 mixture of ethanol and water; the ester phase dissolved immediately. The mixture was heated below its boiling point while stirring for 2 hrs.
The solution was allowed to cool and was acidified with 300 mL of 3N HCl, precipitating a white solid. The product was filtered and washed several times with water. The product was recrystallized by dissolving it in 300 ml methanol followed by 100 ml petroleum ether (30°-65° C.). The product was precipitated by refrigerating at -26° C.
The precipitated product was filtered, washed several times with petroleum ether (55°-60° C.) and dried in a vacuum oven. Yield, 14.8 g (0.040 mole) of fluffy white solid that turns blue in daylight after a short period of time. M.P. 177°-179° C.
Analysis: Calcd. for C 16 H 20 N 2 O 8 : C, 52.17; H, 5.47; N, 7.61; O, 34.75. Found: C, 52.63; H, 5.33; N, 7.38; O, 34.66.
IR Analysis: Urethane: (NH stretch), 3,320; (COO or amide I), 1690; (NH, CN or amide II), 1,550 cm -1 . Acid: (carbonyl), 1,705; (C--O of acid), 1240 cm -1 .
(C)
PREPARATION OF POLY-4,6-DECADIYN-1,10-BIS(BUTOXYCARBONYLMETHYL URETHANE) BY GAMME-RAY RADIATION
20.0 g of 4,6-decadiyne-1,10-bis(butoxycarbonylmethyl urethane) recrystallized from 350 mL isopropylether to a white crystalline product was polymerized by 60 Co γ-ray radiation of 50 Mrad at a dose rate of 1 Mrad per hour. The metallic green trans-1,4-polymerized product was extracted twice in boiling acetone followed by filtration and washings with unheated acetone and dried. Yield; 9.5 g of fine textured metallic green product.
(D)
SAPONIFICATION OF POLY-4,6-DECADIYN-1,10-BIS(BUTOXYCARBONYLMETHYL URETHANE) TO THE POTASSIUM SALT OF THE DIACID
The butyl end group was cleaved by dissolving 9.0 g of the above poly(4,6-decadiyn-1,10-bis(butoxycarbonylmethyl urethane)) in 200 mL chloroform. A solution consisting of 5.5 g KOH dissolved in 200 mL methanol was added slowly while stirring. The product which was allowed to precipitate over several days was filtered, washed with ethanol, and dried in a vacuum oven at 60° C. for 16 hours. Yield; 11.1 g. (The higher than expected yield is due to water or hydration).
(E)
CROSSLINKING OF THE POTASSIUM SALT OF POLY-4,6-DECADIYN-1,10-BIS(CARBOXYMETHYL URETHANE) BY γ-RAY RADIATION IN SOLUTION
A 7.0 g samples of the potassium salt of the poly-4,6-decadiyn-1,10-bis(carboxylmethyl urethane) product of Part (D) of this Example was dissolved in 700 mL distilled water by stirring the mixture for at least 16 hours. The reddish semiviscous solution was set in 3 bottles and exposed to 50 Mrad 60 Co γ-ray radiation at a dose rate of 1 Mrad per hour. The pH of the resulting aqueous products ranged from 7.2 to 7.4. The final aqueous products were not viscous, thus indicating that the product was a crosslinked, water-insoluble polymer in aqueous suspension.
These suspensions, and also solutions of noncrosslinked polymer salt, were tested individually with aqueous solutions of various cations including Ag + , Al 3+ , Ba 2+ , Cd 2+ , Co 2+ , Hg 2+ , Mn 2+ , Pb 2+ , Sn 4+ , Sr 2+ , Zn 2+ , Fe 2+ , Fe 3+ , Cu 2+ , Ca 2+ , Mg 2+ , Cr 2+ , Cr 3+ , and Ni 2+ . All of these metal cations caused precipitation. Accordingly, these crosslinked and noncrosslinked polymers can be used to separate metallic cation impurities, other than alkali metal cations, from water. The metal can be recovered via contacting aqueous acid with the polymeric precipitate, forming an aqueous solution of the metal salt of the acid, which can be separated from the polymeric residue. The alkali metal salt of the polymer can be regenerated as its aqueous solution or dispersion by addition thereto of aqueous alkali. Sodium and also lithium as the cation gives similar results to those obtained using potassium cation in the above Example.
EXAMPLE 4
Recovery of Metals From the Resin
Step 1: In 5 mL of 0.1% solution of the potassium salt of Example 3D in water was added dropwise an aqueous solution of FeCl 3 till the polymer precipitated. The red precipitates were filtered, washed several times with distilled water and collected. The first filtrate was titrated with KSCN solution. No red precipitates were detected. (K has exchanged with Fe 3+ ).
Step 2: When the red precipitates were placed in about 0.1N HCl, the precipitates turned black-violet. The filtrate was titrated with KSCN. The filtrate turned red, indicating Fe 3+ had passed into the aqueous acid and was replaced by 3H + in the polymer.
Step 3: To the dark violet residues, 0.1N KOH solution in water was added. The residues dissolved to form yellow solution. This polymer solution can be recycled to step 1.
WATER SOLUBLE MONOMERS FROM HIGHER ACETYLENES
Additional water soluble monomers were prepared by converting the diols of higher acetylenes (acetylenes having more than two acetylenic groups) to their dicarboxylic acid alkali metal salts. Some of these compositions (designated as "split" tetraynes and hexaynes) have the ethylene radical --(CH 2 CH 2 )-- in the backbone, in accordance with the formula: [M'O(C═O)(CH 2 ) n' (C.tbd.C) 2 (CH 2 ) b (C.tbd.C) b-1 ] 2 where b is 1 or 2, n' being an integer from 1 to 4 and M' being an alkali metal, whereas others have a fully conjugated backbone, in accordance with the formula: [M'O(C═O)(CH 2 ) n' (C.tbd.C) 2 ] 2 .
The general scheme for preparation of the "split" higher acetylenic acids is as follows, wherein each compound is numbered under its formula: ##STR1##
SPECIFIC PROCEDURES FOR SCHEME 1
(A)
Synthesis of 5,7,11-dodecatriyn-1-ol and 5,7,11,13-octadecatetrayn-1,18-diol
The above diols were prepared by the Cadiot-Chodkiewicz technique and are used to make the corresponding urethane derivatives. The synthesis is in accordance with the above Scheme 1.
A mixture of 60 parts methanol, 0.15 part cuprous chloride, 40 parts 70% ethylamine in aqueous solution and 1.5 parts of hydroxylamine hydrochloride was prepared. After stirring the contents a short time, 10.9 parts 1,5-hexadiyn (compound 3 of Scheme 1) was added in one portion. The contents were cooled to 15° C., and 25.0 parts 6-bromo-5-hexyn-1-ol (compound 2 of Scheme 1 with x=3) in 16 parts methanol were added dropwise over a period of 20 minutes while maintaining the temperature between 15° C. to 25° C. After stirring for 4 hours the solvent was removed, leaving a dark viscous layer. The triyn-ol was extracted from the reaction mixture by adding 240 parts of petroleum ether (60°-110° C. boiling range) to the reaction mixture, and heating and stirring and decanting the top layer of the mixture. The extraction was repeated twice, and the petroleum ether solutions were refrigerated at -26° C. The triyn-1-ol product formed (compound 4 of Scheme 1 with=3) was a white viscous layer on the bottom of the petroleum ether which was isolated by decanting off the petroleum ether. It was used to form the hexayn diol in Part B below.
The tetrayn-diol also formed (compound 5 of Scheme 1 with x=3) was isolated by adding 50 parts glacial acetic acid to the remaining portion of the reaction contents, heating, and adding 150 parts of hot water while stirring, after which the contents were refrigerated at -8° C. The product tetrayn-diol, crystallized out, was isolated by filtering and then purified by dissolving in 280 parts hot xylene and refrigerating the xylene extract at -8° C. After crystallization and filtration, the product was washed with petroleum ether and dried in a vacuum oven in the dark, to yield 7.5 parts of final product light in color and fluffy in texture. The melting point of this tetrayn-diol was 118.8° to 121.4° C.
(B)
Preparation of 5,7,11,13,17,19-tetracosahexayn-1,24-diol (Compound 6 with x=3)
A mixture of 2 parts cuprous chloride, 12 parts methanol, and 4 parts N,N,N',N'-tetramethylethylenediamine was prepared. To this mixture over a period of 15 minutes was added 5,7,11-dodecatriyn-1-ol (produced in Part A above) dissolved in 12 parts methanol, while oxygen was moderately bubbled through the reaction contents. After 1 hour, oxygen flow was stopped and the methanol was distilled leaving a semi-viscous residue. To this was added 100 parts of 3N hydrochloric acid while stirring, causing product to precipitate. It was collected by filtration, washed once with 25 parts 2N hydrochloric acid and several times with water. The solid was dissolved in 200 parts xylene and the solution was refrigerated at -8° C. Subsequent crystallization and filtration yielded 6.0 parts of fluffy product, the above hexayne diol, which turns blue in daylight. The melting point of the material was 101.0° to 104.1° C.
EXAMPLES 5 AND 6
The procedure for oxidizing diols (5) and (6) above to the corresponding diacids (7) and (8) wherein x=1, 2, 3 and 4 was essentially the same as for obtaining the diacid of Example 1.
The acids for completely conjugated tetrayns of type,
(HOOC(CH.sub.2).sub.x-1 --C.tbd.C--C.tbd.C).sub.2 (14)
were obtained by converting the respective diols, as follows in Scheme 2 and in Scheme 3: ##STR2##
SPECIFIC PROCEDURES FOR SCHEME 2
Preparation of Diacetylene, Compound (11)
The diacetylene was prepared using the method of T. H. Herberts (Chem. Ber., 85 (1952) 475) cited by M. F. Shostakovskii and A. V. Bogdanova ("The Chemistry of Diacetylenes", p. 11). The procedure used is as follows: To a 3-necked 0.5 L flask fitted with a stirrer, condenser, a dropping funnel, and a nitrogen inlet with a tube extending to the bottom of the reaction flask, 48 g (38.2 mL, 0.39 mol) 1,4-dichloro-2-butyne, 120 mL ethanol, and 4 mL pyridine were added. The reaction medium was raised to reflux, the nitrogen adjusted so that bubbling occurred very gently and then 160 mL aqueous solution of 10N NaOH was added dropwise over 1.75 h. During the addition, the diacetylene evolved as gas (B.P., 10° C.) and was directed through the upper arm of the condenser, purified by bubbling through a wash bottle containing a 150 mL aqueous solution of 10N NaOH, and finally collected, via a dip-tube, at -50° to -70° C. at the bottom of the 3-necked flask described in the following synthesis. Conversion to diacetylene was greater than 95%.
Synthesis of 3,5,7,9-dodecatetrayn-1,14-diol (compound (13) where x=2)
To a 1 L 3-necked flask fitted with a stirrer, thermometer, a dropping funnel, and a nitrogen inlet and outlet 0.4 g CuCl and 300 mL diethylether were added followed by 50 mL ethylamine (70%). After a short period of time 5.0 g hydroxylamine hydrochloride was added while stirring moderately. Afterwards the stirrer was stopped and the medium cooled to -50° to -70° C.
Diacetylene described above was collected at the bottom of this second flask via a dip tube, over a period of 2.25 h and estimated to be approximately 19 g (0.38 mol). The condensation tube was disconnected and the temperature was allowed to rise to -10° C. using a solid carbon dioxide/acetone bath to maintain such temperature.
A solution of 80.0 g (0.536 mol) 4-bromo-3-butyn-1-ol ((2), of Scheme 1 where x=1) diluted with 60 mL diethylether was added dropwise over a period of 0.5 h; a color change from red to brown was noted (Caution: the red color indicates the presence of copper acetylide and therefore a protective shield should be used).
The temperature was then slowly raised 5° C. every 0.5 h until room temperature (25° C.) was obtained. The reaction was continued for an additional 0.5 to 1.0 h; then the mixture was acidified by adding 200 mL 2.8N HCl slowly and the reaction medium was separated in a separatory funnel saving the ether layer. The inorganic layer was extracted twice with additional ether using 100 mL each time. The combined ether extract was washed with 100 mL water and separated. The ether layer was reduced to 200 mL and 800 mL n-hexane added to precipitate the product. The product was filtered, washed with n-hexane and recrystallized by dissolving in 600 mL warm xylene followed by 1,600 mL n-hexane and cooling at -8° C. Yield after crystallization; 21.8 g of white solid that in daylight turns first green, then blue. ##STR3##
SPECIFIC PROCEDURES FOR SCHEME 3
Preparation of 2,4,6,8-Decatetrayn-1,10-Diol, Compound (17)
2,4-pentadiyne-1-ol (16) was prepared according to the method of J. B. Armitage, E. R. Jones and M. C. Whiting, J. Chem. Soc. 3317 (1953); and coupled using the method of A. S. Hay (J. Polymer Sci., 7, 1625 (1960)).
EXAMPLES 7-10
The procedure for oxidizing diols (13) of Scheme 2 above wherein x=2, 3, or 4; and for oxidizing diol (17) of Scheme 3 to the corresponding diacids is essentially the same as for obtaining the diacid of Example 1, above.
TECHNIQUES FOR ACTIVATION OF AN INDICATOR BASED ON ION EXCHANGE
In general, not all of the acetylenic acids are transformable to their inactive salts. (Inactive carries the meaning of not undergoing a color change due to polymerization either upon thermal annealing or by irradition, such as indefinitely long exposure at room temperature to daylight). As a consequence two techniques were used to employ the acetylenic acids as indicators of the combined effects due to time and temperature of thermal exposure, or due to time and intensity of irradiation. The first is based on activation of the monomer in salt form by conversion to the acid form, whereas the second is dependent on the characteristic water solubility of the polymeric alkali metal salts.
TECHNIQUE 1
For diacid compounds that formed inactive salts, a 10 to 20% aqueous solution of the disodium salt was prepared by adding to the diacid an equimolar amount of NaOH. The solution was applied to a filter paper substrate and dried, leaving the inactive disodium salt of the diacid on the filter paper.
One-half inch tabs were cut from the coated paper and placed on a layer of microcapsules (commercially available) containing an aqueous citric acid solution. The tab and the capsules were then encased in a polyethylene film. In order to activate the tab, the microcapsules are broken by crushing. The ensuing acid-salt exchange converts the indicator to its active acid form. The color change occurring, as the acid form polymerizes, varies according to the conjugated acetylenic acid which is used. In general, the higher the conjugation, the greater the reactivity and consequently the greater the rate of color change which occurs.
TECHNIQUE 2
For those acids which could not be inactivated by transformation to their sodium salts, the acid form was dissolved in a suitable solvent, e.g. acetone, and applied to a filter paper substrate and converted either by heat or U.V. light to its polymer, colored e.g. blue. Behind the paper substrate a microporous film was placed followed by a wet tab that had been soaked in NaOH. In the wet state sodium ions migrate, at a rate depending on the temperature, through the microporous film to produce a color change on the filter paper, blue to red, as the polymer is converted to its sodium salt. Such device accordingly serves as an indicator of the combined effects of time and temperature exposure, i.e. as a time/temperature indicator. (The rate of migration at constant temperature in general decreases with time, so that it may be desirable in some cases to calibrate the device in the time/temperature region of interest).
If the NaOH tab is dry, no sodium ions migrate and no color change occurs at the filter paper surface carrying the polymer in acid form. For dry NaOH on the tab, activation can be accomplished by incorporation (behind the tab) of water filled microcapsules (commercially available); breaking of the capsules by pressure releases the water to activate the indicator.
MODIFICATION OF TECHNIQUE 1
With certain of the above acetylenic di-salts, the shade changes when the salt form is converted to the acid, as the acid polymerizes. For example, the acid form as it polymerizes may develop a change in shade from light blue to a very dark blue. In terms of perceptual interpretability, the effects may be less than satisfactory. For this reason, in order to bring out better color distinguishability, the color development can be enhanced by employing a colored substrate and incorporating an acid-base pH indicator. Such modification results in the color being initially the combined color of the substrate, plus the color due to the pH sensitive acid-base indicator, plus the color of the inactive time-temperature indicator under basic conditions. Activation by releasing, for instance, a solution of citric acid gives the combined effect of the colored substrate and the acid form of the pH indicator which enhance the perceptibility of the color development of the time-temperature indicator. The system results in color transitions rather than only a color intensification as the color of the polyacetylenic polymeric acid develops.
EXAMPLE 11
An example of the foregoing activation TECHNIQUE 1 is described for (HOOC(CH 2 ) 3 --C.tbd.C--C.tbd.C--CH 2 ) 2 , i.e. Compound (7) of Scheme 1, with x=3.
A 1" (25.4 mm) square yellow paper was soaked in an aqueous solution composed of 1 part 0.3% dichlorofluorescein and 1 part of a 10% solution of the disodium salt of the above diacid. Nine 1/4" (6.35 mm) diameter circular tabs were cut from the paper and placed in a testing device constructed by equally punching out 1/4" (6.35 mm) holes in a 1"×1"×1/16" (25.4×25.4×1.59 mm) polyethylene holder. In each hole, one of the pre-cut tabs was placed. Behind each tab a layer of capsules containing a citric acid solution was placed. The entire construction was sandwiched between two stick-type clear Mylar® polyester sheets. The test device was left at room temperature and tested by breaking one tab of the set of 9 sequentially for a period of 9 days and observing the results as color development occurred. The results are as follows: Color changes for days 0, 1, 3, 4, 5, 8, 10, 11, 12 were orange, yellow, yellow-green, green, green-blue, medium-blue, dark-blue, dark-blue and dark-blue, respectively, as the diacetylenic acid polymerized.
EXAMPLE 12
An example of the foregoing TECHNIQUE 2 for activation follows.
A 1/2" (12.7 mm) square white filter paper tab was soaked in a 10% solution of 4,6-decadiyn-1,10-bis(carboxylmethyl urethane), i.e. the product of Example 3(B). After drying, the tab was developed to a medium blue color by exposure to U.V. light, which polymerized the diacetylenic diacid.
The tab was sealed between a film of clear polyethylene (front) and a microporous film (back) permeable by aqueous solutions, (specifically the product o the Celanese Plastics Company, CELGARD number 5511). A 1/2" (12.7 mm) square piece of filter paper was soaked in 5N NaOH and placed behind the microporous film and joined to the sealed tab by enclosing the whole with polyethylene film. The resulting indicator device was left at ambient conditions. After 20 hours the color had changed from a medium blue to a medium orange color.
The color development of this indicator is dependent on the flow rate of the aqueous NaOH through the microporous film at a particular temperature. Therefore, by using microporous films having differing flow rate characteristics, different color development times are achieved under the same temperature exposures.
EXAMPLE 13
A 0.004% solution of polymer of Example 3(D) was made in deionized water. The absorption spectrum of the polymer alone was recorded in a spectrophotometer.
Individual solutions of metal salts of Cu ++ , Ni ++ , Al +++ , Co ++ , and Cr +++ in concentrations of the metal ion from 0.1 to 10 ppm were also made in deionized water. With the same 0.004% polymer concentration maintained, the metal ionic solutions were added individually to the polymer solution; and the spectra of the resulting solutions were recorded.
For Cu ++ , a wide structureless absorption spectrum was produced with a peak at 462 nm. All of the spectra were similar, all showing a regular gradual shift toward the red, with increasing metal ion concentration. Regular growth of a secondary peak at higher wavelength also was observed as the concentration of the given metal ion increased.
The intensity of the primary peak decreases, more and more, as the concentration of the given metal ion increases.
The close similarity of the absorption spectra produced by the polymer with various metal ions allows use of the subject water soluble polymer salts of alkali metals for qualitative and semiquantitative detection of presence of metallic impurities in water, down as low as a parts per billion level, by comparing the spectrum of the unknown plus polymer against the standard spectrum for the polymer alone; without necessarily separating or identifying the individual metallic impurities.
If the unknown is a single metal, its concentration can be determined quantitatively at such levels by comparison of a series of such spectra against a series of standards made up as above, from a solution of polymer, plus solutions of a compound of that metal in varying concentration.
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Water-soluble polyacetylenic alkali metal salts from monomers and polymers of carboxymethyl urethanes of di-, tetra-, and hexayne diols, or from the corresponding diacids; useful in thermal and irradiation exposure indicators and/or in detection and/or removal of nonalkali metal ions dissolved in aqueous media.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2011-063830, filed on Mar. 23, 2011 and Japanese Patent Application No. 2011-174222, filed on Aug. 9, 2011. The entire disclosure of Japanese Patent Application No. 2011-063830 and Japanese Patent Application No. 2011-174222 are hereby incorporated herein by reference.
BACKGROUND
1. Technical Field
The technology disclosed herein relates to an electronic device and an imaging device equipped with an air pressure sensor.
2. Background Information
It is conventionally known in the art to test the watertightness (whether or not a watertight state is maintained) of a housing having a watertight structure. For instance, in Japanese Laid-Open Patent Application 2010-135429, a separate apparatus had to be connected in order to test the device in question.
SUMMARY
It has been discovered that the aforementioned conventional method for testing is difficult to apply while an ordinary user is using an electronic device.
Accordingly, one object of technology disclosed herein is to provide a device in which a testing for watertightness can be performed with a simple structure.
In accordance with one aspect of the technology disclosed herein, an electronic device is provided that includes a housing, a waterproof air-permeable membrane, a door, an air pressure gauge and a watertightness detector. The housing defines an opening and includes an air vent. The waterproof air-permeable membrane blocks off the air vent. The door is shiftably coupled to the housing and movable between a first position that uncovers the opening and a second position that covers the opening. The door and the housing form a watertight structure when the door is in the second position. The air pressure gauge is disposed inside the watertight structure. The watertightness detector is configured to determine whether the housing and the door have maintained a watertight state based on changes in the air pressure inside the watertight structure when the door moves from the first to the second position. The changes in the air pressure are measured by the air pressure gauge.
These and other features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred and example embodiments of the present invention.
BRIEF DESCRIPTION OF DRAWINGS
Referring now to the attached drawings which form a part of this original disclosure:
FIG. 1A and FIG. 1B are front oblique views of the digital camera 1 pertaining to an embodiment;
FIG. 2 is a rear oblique view of the digital camera 1 pertaining to an embodiment;
FIG. 3 is a front view of a housing 10 pertaining to an embodiment;
FIG. 4 is a rear oblique view of the housing 10 pertaining to an embodiment;
FIG. 5 is an exploded oblique view of the housing 10 pertaining to an embodiment;
FIG. 6 is a cross section along the A-A line in FIG. 3 ;
FIG. 7 is a function block diagram of the digital camera 1 pertaining to an embodiment;
FIG. 8 is a function block diagram of a controller 110 pertaining to an embodiment;
FIG. 9 is a flowchart illustrating the operation of a system-on-a-chip 100 ;
FIG. 10 is a flowchart illustrating the operation of a watertightness detector 115 ; and
FIG. 11A and FIG. 11B are graphs of the relation between the open/closed state of a door 12 and the air pressure inside the housing 10 .
DETAILED DESCRIPTION OF EMBODIMENTS
Selected embodiments will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
In the following embodiments, a digital camera will be used as an example in describing an imaging device. In the following description, using a digital camera in its landscape orientation as a reference, the subject side will be referred to as the “front,” the opposite side from the subject as the “rear,” the vertically upward part as “upper,” the vertically downward part as “lower,” the right side in a state of facing the subject head on as the “right,” and the left side in a state of facing the subject head on as the “left.” “Landscape orientation” is the orientation when the long-side direction of a captured image substantially coincides with the horizontal direction in the captured image.
Simplified Configuration of Digital Camera 1
The simplified configuration of the digital camera 1 pertaining to the embodiment will be described through reference to the drawings. FIG. 1A and FIG. 1B are front oblique views of the digital camera 1 pertaining to the embodiment. FIG. 1A shows the state when the door 12 is closed, and FIG. 1B shows the state when the door 12 is open. FIG. 2 is a rear oblique view of the digital camera 1 pertaining to the embodiment.
The digital camera 1 comprises a housing 10 , a door 12 , a front cover 20 , a rear cover 30 , a manipulation unit 40 , an optical system 50 , a liquid crystal monitor 60 , a flash 65 , a card slot 93 , and an open/closed detector switch 150 .
The housing 10 is a holding vessel that constitutes a watertight structure along with the door 12 . The housing 10 deforms under water pressure when immersed in water. Specifically, the amount of deformation of the housing 10 increases in proportion to the water depth. This housing 10 is preferably made of a material that is flexible and elastic. The housing 10 has an opening 10 a and a frame 10 b . The opening 10 a is formed taller than it is wide on the side face of the housing 10 . The frame 10 b is formed so as to surround the opening 10 a on the side face of the housing 10 . The opening 10 a is blocked off when the door 12 is snugly fitted to the frame 10 b.
The door 12 can be opened by sliding an open/close switch 12 a provided to the door 12 in the “open” direction during replacement of a memory card 93 b , a battery 97 , etc. The door 12 is connected to the housing 10 via a hinge 12 d . The door 12 rotates with the hinge 12 d as its rotational center, which allows it to transition between an “open” state of not covering the opening 10 a and a “closed” state of covering the opening 10 a . A gasket 12 b is disposed surrounding the inner face of the door 12 and fits snugly against the frame 10 b of the housing 10 , which puts the housing 10 in a watertight state in the “closed” state. Thus, the door 12 is provided so that the opening 10 a of the housing 10 can be opened and closed, and constitutes a watertight structure along with the housing 10 in its “closed” state of covering the opening 10 a.
The card slot 93 is used to removably insert the memory card 93 b . The battery 97 supplies power for operating the digital camera 1 . The memory card 93 b and the battery 97 are on the inside of the frame 10 b , and can be removed when the door 12 is opened.
A protrusion 12 e is disposed in the bounded region of the inner face of the door 12 , the bounded region is bounded by the gasket 12 b . The open/closed detector switch 150 is provided on the inside of the opening 10 a surrounded by the frame 10 b of the housing 10 . The protrusion 12 e is provided at a location where it will press on the open/closed detector switch 150 when the door 12 is closed. In this embodiment, the protrusion 12 e and the open/closed detector switch 150 constitute a means for detecting whether the door is open or closed. When the door 12 is closed, the open/closed detector switch 150 is pressed by the protrusion 12 e , that is, the open/closed detector switch 150 enters its ON state, and a controller 110 (discussed below) detects that the door 12 has been closed. When the door 12 is opened, the open/closed detector switch 150 enters its OFF state, and the controller 110 detects that the door 12 has been opened.
The front cover 20 is attached to the front face of the housing 10 . The rear cover 30 is attached to the rear face of the housing 10 . The operation unit 40 is attached to the rear face of the housing 10 , and is exposed from the rear cover 30 .
The operation unit 40 handles various inputs from the user. In this embodiment, the operation unit 40 handles the selection of the water depth measurement mode as one of the imaging modes. The optical system 50 is attached to the front face of the housing 10 , and is exposed from the front cover 20 . The optical system 50 lets external light into the interior of the housing 10 during imaging. The liquid crystal monitor 60 is attached to the rear face of the housing 10 , and is exposed from the rear cover 30 . Captured images are displayed on the liquid crystal monitor 60 . The flash 65 is attached to the front face of the housing 10 , and is exposed from the front cover 20 .
Internal Configuration of Housing 10
FIG. 3 is a front view of the housing 10 pertaining to the embodiment. FIG. 4 is a rear oblique view of the housing 10 pertaining to the embodiment. FIG. 5 is an exploded oblique view of the housing pertaining to the embodiment. FIG. 6 is a cross section along the VI-VI line in FIG. 3 . In FIGS. 3 and 4 , the door 12 is attached to the housing 10 .
The housing 10 is constituted by a front panel 70 and a rear panel 80 , and a control board 90 is disposed in the interior of the housing 10 . The front panel 70 and rear panel 80 are fitted snugly together in order to ensure the watertightness of the housing 10 . Although not depicted in the drawings, a concave component constituting the opening 10 a is formed on the right side face of each of the front panel 70 and rear panel 80 . The control board 90 is sealed in between the front panel 70 and the rear panel 80 .
The front panel 70 has an air vent 71 and a waterproof air-permeable membrane 72 . The air vent 71 communicates between the inside and outside of the housing 10 . The waterproof air-permeable membrane 72 blocks off the air vent 71 . The waterproof air-permeable membrane 72 is made from a material that is air-permeable. Accordingly, when the digital camera 1 is located in the air, the air pressure inside the housing 10 coincides with the atmospheric air pressure. Also, the waterproof air-permeable membrane 72 is made from a material that is waterproof. Accordingly, when the digital camera 1 is located in water, infiltration by water through the air vent 71 is suppressed. An example of a material that can be used for the waterproof air-permeable membrane 72 is Gore-Tex® made by W.L. Gore & Associates.
The air pressure change inside the housing 10 will now be described through reference to the drawings. FIG. 11A and FIG. 11B show the relation between the open/closed state of the door 12 and the air pressure inside the housing 10 . FIG. 11A is a graph of the change in air pressure inside the housing 10 when the door 12 has been closed from its open state. Time is plotted on the horizontal axis, and the air pressure inside the housing 10 on the vertical axis. The solid line indicates an example of the change in air pressure inside the housing 10 when the housing 10 maintains a watertight state. The one-dot chain line indicates an example of the change in air pressure inside the housing 10 when the housing 10 does not maintain a watertight state. FIG. 11B is a graph of the state of the open/closed detector switch 150 . The open/closed detector switch 150 changes from OFF to ON at time A in synchronization with the timing at which the air pressure inside the housing 10 suddenly rises.
In this embodiment, a watertight state is maintained, and immediately after the door 12 is closed (the open/closed detector switch goes ON), there is a slight rise in the air pressure inside the housing 10 (time A). After this, air flows in and out through the waterproof air-permeable membrane 72 . However, the flow of air through the waterproof air-permeable membrane 72 is less than when the watertight state is not being maintained with the door 12 closed, that is, when the gasket 12 b and the frame 10 b are not fitted snugly together. Accordingly, when a watertight state is maintained, the time it takes for the air pressure inside the housing 10 to equalize with atmospheric pressure after the door 12 has been closed is longer than when a watertight state is not being maintained (time C; in this embodiment, the elapsed time from time A is approximately 1 minute). However, if foreign matter clings to the gasket 12 b of the door 12 , for example, the gasket 12 b and the frame 10 b will not fit snugly together, and there will be a gap. Since air flows out through this gap, the watertightness inside the housing is lost and the rise in air pressure when the door 12 is closed is less than when a watertight state is maintained, and also the time it takes the air pressure inside the housing 10 to equalize with atmospheric pressure is shorter (time B; in this embodiment, the elapsed time from time A is approximately 2 seconds). The time it takes for the air pressure inside the housing 10 to equalize with atmospheric pressure is greatly affected by the size of the air vent 71 and the air permeability of the waterproof air-permeable membrane 72 .
A waterproof tape (not shown) is attached between the front plate 70 and the optical system 50 and flash 65 . A gasket (not shown) is attached between the rear plate 80 and the operation unit 40 and liquid crystal monitor 60 .
The control board 90 has a board main body 91 ; a sensor unit 92 , a card slot 93 , and an AFE (analog front end) 94 installed on the front face of the board main body 91 ; and a system-on-a-chip 100 installed on the rear face of the board main body 91 .
The board main body 91 is a flat member on which various electronic parts can be installed.
As shown in FIG. 6 , the sensor unit 92 has an air pressure sensor 92 a and a temperature sensor 92 b . The air pressure sensor 92 a detects the internal pressure inside the housing 10 . When the digital camera 1 is located in the air, the detected air pressure value P detected by the air pressure sensor 92 a is in agreement with atmosphere pressure. When the digital camera 1 is located under water, the detected air pressure value P detected by the air pressure sensor 92 a rises in proportion to the water depth of the housing 10 , that is, in proportion to the decrease in volume inside the housing 10 . The temperature sensor 92 b detects the temperature inside the housing 10 .
The card slot 93 is used to removably insert a memory card. The AFE 94 subjects image data produced by a CCD image sensor 95 (one example of an “imaging means” discussed below) to noise suppression processing, processing for amplification of the input range width of an A/D converter, A/D conversion processing, and so forth.
The system-on-a-chip 100 provides overall control over the operation of the various electronic parts comprised by the digital camera 1 . The configuration of the system-on-a-chip 100 will be discussed below.
Functional Configuration of Digital Camera 1
FIG. 7 is a function block diagram showing the functional configuration of the digital camera 1 pertaining to the embodiment. In the following description, the configuration other than that discussed above will mainly be described.
The optical system 50 has a focus lens 51 , a zoom lens 52 , an aperture 53 , and a shutter 54 . The focus lens 51 adjusts the focus state of the subject. The zoom lens 52 adjusts the field angle of the subject. The aperture 53 adjusts the amount of light incident on the CCD image sensor 95 . The shutter 54 adjust the exposure time of the light incident on the CCD image sensor 95 . The focus lens 51 , the zoom lens 52 , the aperture 53 , and the shutter 54 are each driven by a DC motor, a stepping motor, or another such drive unit according to a command signal send from a controller 110 .
The CCD image sensor 95 is an example of the “imaging means” pertaining to the embodiment. The CCD image sensor 95 produces image data by opto-electrical conversion.
The system-on-a-chip 100 has the controller 110 , an image processor 120 , a buffer memory 130 , and a flash memory 140 .
The controller 110 provides overall control of the operation of the entire digital camera 1 . The controller 110 is constituted by a ROM, a CPU, etc. The ROM contains programs for file control, autofocus control (AF control), automatic exposure control (AE control), and operational control over the flash 65 , as well as programs for the overall control of the operation of the entire digital camera 1 .
In this embodiment, the controller 110 has a mode detector 111 , an air pressure value corrector 112 , a differential calculator 113 , and a water depth calculator 114 and a watertightness detector 115 . If the user has selected water depth measurement mode with the manipulation unit 40 , the controller 110 calculates the water depth D of the housing 10 on the basis of the air pressure P detected by an air pressure sensor 92 a . The controller 110 here reads a reference air pressure value P 0 and a reference air temperature value t 0 from a flash memory 140 . Also, if the controller 110 detects that the open/closed detector switch 150 is ON, that is, that the door 12 has transitioned from its open state to its closed state, then the watertightness detector 115 decides whether or not the housing 10 is in a watertight state. The functional configuration and operation of the controller 110 will be discussed below.
The controller 110 can also be constituted by a hard-wired electronic circuit or a microprocessor that executes programs.
The image processor 120 subjects the image data that has undergone various processing by the AFE 94 to white balance correction, color reproduction correction, gamma correction, smear correction, YC conversion processing, electronic zoom processing, and other such processing. In this embodiment, the image processor 120 subjects the image data to white balance correction, color reproduction correction, and gamma correction when the water depth value D of the housing 10 exceeds a specific water depth (such as about 3 meters). Here, the image processor 120 performs the white balance correction, color reproduction correction, and gamma correction so as to minimize an increase in blueness in the captured image (that is, a decrease in redness in the captured image).
The image processor 120 can also be constituted by a hard-wired electronic circuit or a microprocessor that executes programs.
The buffer memory 130 is a volatile storage medium that functions as a working memory for the controller 110 and the image processor 120 . In this embodiment, the buffer memory 130 is a DRAM.
The flash memory 140 is an internal memory of the digital camera 1 . The flash memory 140 is a non-volatile storage medium. In this embodiment, the reference air pressure value P 0 and reference air temperature value t 0 are stored in the flash memory 140 .
Measuring Water Depth Value D from Detected Air Pressure Value P
The waterproof air-permeable membrane 72 blocks off the air hole 71 in the digital camera 1 . When atmospheric pressure changes occur in the atmosphere, the internal pressure inside the housing 10 is changed in accordance with the atmospheric pressure due to the air permeability of the waterproof air-permeable membrane 72 . Consequently, the air pressure inside the housing 10 is equal to the atmospheric pressure.
Then the digital camera 1 is gradually lowered in altitude and the air pressure inside the housing 10 becomes substantially equal to the atmospheric pressure at the altitude of the water surface just after the digital camera 1 drops under a water surface. After this, as the camera is submerged in the water, there is no change in the air pressure inside the housing 10 , assuming the housing 10 is not deformed by water pressure. In actual practice, however, the housing 10 of the digital camera 1 is gradually deformed by the water pressure, which increases along with the water depth. This deformation is accompanied by a gradually rise in the air pressure inside the housing 10 . The external water pressure (the water depth value D) can be estimated by measuring the air pressure change inside the housing 10 . This is how the water depth value D is measured (estimated) with the digital camera 1 in this embodiment.
Specifically, air pressure change inside the housing 10 attributable to deformation of the housing 10 by water pressure is measured by the air pressure sensor 92 a , and the water pressure (the water depth value D) can be estimated on the basis of this air pressure change. The relation between the air pressure change inside the housing 10 and the water pressure (the water depth value D) can be approximated by a specific nonlinear function (hereinafter referred to as a “water depth calculation function”).
Functional Configuration of Controller 110
FIG. 8 is a function block diagram of the functional configuration of the controller 110 pertaining to the embodiment.
The controller 110 has the mode detector 111 , the air pressure value corrector 112 , the differential calculator 113 , and the water depth calculator 114 and the watertightness detector 115 .
The mode detector 111 decides whether or not the camera is in water depth measurement mode. Setting and unsetting of the water depth measurement mode are performed with the operation unit 40 . If the mode detector 111 decides that the camera is in water depth measurement mode, a notification to that effect is sent to the air pressure value corrector 112 .
The air pressure value corrector 112 performs temperature correction on the detected air pressure value P detected by the air pressure sensor 92 a on the basis of the reference air temperature value t 0 stored in the flash memory 140 and the detected temperature value t detected by the temperature sensor 92 b . More specifically, the air pressure value corrector 112 calculates the corrected air pressure value P′ from the following formula (I).
P′=P ×(273.2+ t 0 )÷(273.2+ t ) (1)
The differential calculator 113 calculates the differential ΔP between the reference air pressure value P 0 stored it the flash memory 140 and the corrected air pressure value P′ calculated by the air pressure value corrector 112 . This differential ΔP is the relative amount of change in air pressure relative to the reference air pressure value P 0 .
The water depth calculator 114 calculates the water depth value D on the basis of the differential ΔP found by a differential detector 102 and the water depth calculation function. The water depth calculator 114 displays the calculated water depth value D on the liquid crystal monitor 60 . Also, the water depth calculator 114 notifies the image processor 120 when the calculated water depth value D exceeds the specific water depth (such as about 3 meters). The image processor 120 subjects the image data to white balance correction, color reproduction correction, and gamma correction according to the notification from the water depth calculator 114 .
Upon detecting that the open/closed detector switch 150 is ON, that is, that the door 12 is in its closed state, the watertightness detector 115 decides whether or not the housing 10 is in a watertight state on the basis of the change in the air pressure value P detected by the air pressure sensor 92 a . If it is decided that the housing 10 is not in a watertight state, a warning is displayed on the liquid crystal monitor 60 .
Operation of System-on-a-Chip 100
The operation of the system-on-a-chip 100 pertaining to the embodiment will be described through reference to the drawings. FIG. 9 is a flowchart illustrating the operation of the system-on-a-chip 100 . In the following description, we will assume that the water depth measurement mode has been detected by the mode detector 111 .
In step S 10 , the controller 110 reads the reference air pressure value P 0 and reference air temperature value t 0 stored in the flash memory 140 .
In step S 20 , the controller 110 decides whether or not the water depth measurement mode is continuing. If the water depth measurement mode is continuing, the processing proceeds to step S 30 . If the water depth measurement mode has been switched off by the mode detector 111 , the water depth measurement processing is ended.
In step S 30 , the controller 110 detects the detected air pressure value P outputted from the air pressure sensor 92 a , and the detected temperature value t outputted from the temperature sensor 92 b.
In step S 40 , the controller 110 finds the temperature-corrected air pressure value P′ from the reference air temperature value t 0 read in step S 10 and the detected air pressure value P and the detected temperature value t detected in step S 30 .
In step S 50 , the system-on-a-chip 100 calculates the differential ΔP between the reference air pressure value P 0 read in step S 10 and the temperature-corrected air pressure value P′ calculated in step S 40 .
In step S 60 , the controller 110 finds the water depth value D by using the water depth calculation function and the differential ΔP found in step S 50 .
In step S 70 , the controller 110 displays the water depth value D found in step S 60 on the liquid crystal monitor 60 .
In step S 80 , the controller 110 decides whether or not the water depth value D found in step S 60 exceeds the specific water depth (such as about 3 meters). If the specific water depth is exceeded, the processing proceeds to step S 90 . If the specific water depth is not exceeded, the processing proceeds to step S 20 .
In step S 90 , the image processor 120 performs white balance correction, color reproduction correction, and gamma correction on the image data.
Operation of Watertightness Detector 115
The operation of the watertightness detector 115 pertaining to this embodiment will be described through reference to the drawings. FIG. 10 is a flowchart illustrating the operation of the watertightness detector 115 . The following description is of the operation in a state in which power has been switched on to the digital camera 1 and the door 12 is in its closed state, that is, a state in which “off” has been detected by the open/closed detector switch 150 .
In step S 101 , the watertightness detector 115 decides whether the open/closed detector switch 150 is ON or OFF. If OFF, the state of the open/closed detector switch continues to be monitored. If ON, the flow moves to step S 102 .
In step S 102 , the watertightness detector 115 starts a counter.
In step S 103 , the watertightness detector begins sampling the air pressure value of the air pressure sensor 92 a . More specifically, the air pressure value of the air pressure sensor 92 a is acquired for each processing performed in step S 103 , and this is stored in the flash memory 140 . The flash memory 140 stores the air pressure values acquired a specific number of times in the past (such as the last 10 times).
In step S 104 , an evaluation is made as to whether the change in the air pressure value is a specific value or lower on the basis of the air pressure values stored in step S 103 . In this embodiment, more specifically, the air pressure values acquired a certain number of times are compared, and if the change falls within a specific range that can be considered to be substantially no change, then the air pressure inside the housing and the air pressure outside are considered to be equal, and the flow moves to step S 105 . For example, the differences between two consecutively acquired air pressure values are found successively for the last ten air pressure values that have been acquired, and if the total value is below a specific threshold, the air pressure inside the housing can be considered equal to the air pressure outside. If the air pressure value is not within the specific range, the counter is increased by one, and the flow returns to step S 103 .
In step S 105 , the counter value is checked. If the counter value is at least a specific value, it is determined that a watertight state is being maintained, and the flow moves to step S 106 . If the counter value is less than the specific value, it is determined that foreign matter or the like has stuck to the door and the watertight state has been lost, and the flow moves to step S 107 .
In step S 106 , the watertightness detector 115 displays on the liquid crystal monitor 60 that the status is normal, and notifies the user that a watertight state is in effect. Furthermore, the watertightness detector 115 automatically starts the operation of watertightness testing by moving the open/closed detector switch from OFF to ON, regardless of the intention of the user. Therefore, if the status is normal, the processing of step S 106 may be omitted.
In step S 107 , the watertightness detector 115 displays a warning on the liquid crystal monitor 60 , and notifies the user that the housing is not in a watertight state.
EFFECTS OF THE INVENTION
(1) The digital camera 1 pertaining to an embodiment comprises the housing 10 having the opening 10 a and the air vent 71 , the waterproof air-permeable membrane 72 provided so as to block off the air vent 71 , the door 12 that constitutes a watertight structure along with the housing 10 by entering a closed state of covering the opening 10 a , the air pressure sensor 92 a provided inside the watertight structure, and the watertightness detector 115 that determines whether or not the housing 10 and the door 12 are maintaining a watertight state on the basis of the change in the air pressure within the watertight structure as measured by the air pressure sensor 92 a.
Thus, whether or not the housing 10 and the door 12 are maintaining a watertight state is determined on the basis of the change in the air pressure within the watertight structure, so whether or not a watertight state is being maintained can be determined with just the digital camera 1 . Also, an electronic device and imaging device can be provided with which a test for watertightness can be performed with a simple structure.
(2) The digital camera 1 pertaining to an embodiment comprises the open/closed detector switch 150 that detects that the door 12 is in a closed state and that the door 12 is in an open state (and not a closed state), and the watertightness detector 115 determines that a watertight state is not being maintained when the change in the air pressure measured by the air pressure sensor 92 a drops below the specific value within a specific length of time after the open/closed detector switch 150 has detected that the door 12 has changed from its open state to its closed state.
Thus, whether or not the digital camera 1 is maintaining a watertight structure can be determined from whether or not there is a change (reduction) in the air pressure inside the housing 10 within a short time after the door 12 has been closed.
Other Embodiments
The present invention is described by the embodiment above, but this should not be interpreted to mean that the text and drawings that form part of this disclosure limit this invention. Various substitute embodiments, working examples, and implementation techniques will probably be obvious to a person skilled in the art from this disclosure.
(A) In the above embodiment, the controller 110 began calculation processing for the water depth value D when the user has selected the water depth measurement mode, but this is not the only option. The calculation of the water depth value D may be begun when entry of the housing 10 into water has been detected if the digital camera 1 comprises a water entry detector for detecting the entry of the housing 10 into water. In this case, since entry into water can be detected automatically, the water depth value D can be measured more accurately than when the calculation processing for the water depth value D is begun in response to operation by the user. Furthermore, the controller 110 may have a water entry detector that detects the entry of the housing 10 into water in response to a change in voltage between a pair of electrodes provided on the outer surface of the housing 10 .
(B) In the above embodiment, the controller 110 used specific values stored in the flash memory 140 as the reference air pressure value P 0 and the reference air temperature value t 0 , but this is not the only option.
For example, the controller 110 may use as the reference air pressure value P 0 the detected air pressure value P when selection of the water depth measurement mode has been detected. In this case, the water depth value D can be calculated by referring to how high the atmospheric pressure is at the point when calculation processing is started for the water depth value D. Accordingly, the water depth value D can be calculated more accurately.
Also, the controller 110 may use as the reference air pressure value P 0 the detected air pressure value P when entry of the housing 10 into water has been detected by the above-mentioned water entry detector. In this case, the detected air pressure value P at the point of water entry can be used as a reference, so the water depth value D can be calculated more accurately.
Furthermore, the controller 110 may use as the reference air pressure value P 0 the detected air pressure value P at a point in time designated by the user. In this case, the point of water entry can be accurately ascertained even if the above-mentioned water entry detector is not provided, so the water depth value D can be calculated more accurately.
(C) In the above embodiment, the image processor 120 performed white balance correction, color reproduction correction, and gamma correction when the water depth value D exceeded the specific water depth, but this is not the only option. For example, the image processor 120 may gradually increase the strength of the white balance correction, color reproduction correction, and gamma correction as the water depth value D becomes larger. In this case, since the correction strength can be altered according to the water depth value D, the quality of a captured image can be further improved.
Also, the image processor 120 may perform just one correction from among white balance correction, color reproduction correction, and gamma correction in order to minimize the increase in blueness of the captured image.
(D) In the above embodiment, the water depth calculator 114 calculated by the water depth value D, but this is not the only option. The water depth calculator 114 may calculate a “water pressure value” instead of the water depth value D. This “water pressure value” can be calculated from the water depth calculation function described in the above embodiment, or a similar function.
(E) In the above embodiment, the digital camera 1 (an example of an “imaging device”) was given as an example of an “electronic device,” but this is not the only option. Examples of the “electronic device” include video cameras, portable telephones, IC recorders, and so forth.
(F) In the above embodiment, whether the door 12 was open or closed was detected by the open/closed detector switch 150 , but the present invention is not limited to this. When the air pressure measured by the air pressure gauge 92 a first rises from a steady state air pressure value (=atmospheric pressure) and reaches a maximum value and then drops back down to the steady state air pressure value, it may be determined that a watertight structure is not being maintained if the time between reaching a maximum value and the return to a steady state air pressure value is no more than a specific length of time. More specifically, when watertightness testing mode is selected by the user through the manipulation unit 40 , the watertightness detector 115 begins sampling with the air pressure sensor 92 a . A display is made on the liquid crystal monitor 60 to close the door 12 (after first opening the door 12 if the door 12 was closed), after when the system goes into standby mode. If the watertightness detector 115 detects a maximum value by monitoring the change in the air pressure value, that point in time is determined to be the instant when the door was closed, and the counter is started. In detecting the maximum value, for example, if after the start of sampling, a rise begins from a steady state (that is, atmospheric pressure) in which the air pressure value is held constant, and then a decrease begins, the maximum air pressure value within that range can be termed the maximum value. The processing after this is the same as that starting with step S 103 in FIG. 10 .
(G) In the above embodiment, the watertightness detector 115 compared the air pressure values acquired a certain number of times as in steps S 103 and S 104 , and if the change fell within a specific range that could be considered to be substantially no change, then the air pressure inside the housing and the air pressure outside were considered to be equal, but the present invention is not limited to this. For instance, the air pressure value (that is, atmospheric pressure) acquired from the air pressure sensor 92 a in a state in which the door 12 is open (when the open/closed detector switch 150 is OFF) is stored ahead of time, and if the air pressure value from the air pressure sensor 92 a is equal to atmospheric pressure (or if the difference between the air pressure value and the atmospheric pressure is equal to or lower than a specific value) after the door 12 has been closed (after the open/closed detector switch 150 has changed from OFF to ON), the flow may proceed to step S 105 .
(H) In the above embodiment, the watertightness detector 115 measured time by means of a counter value, but the present invention is not limited to this. The digital camera 1 may be equipped with a clock, so that the watertightness detector 115 acquires and stores the start time in step S 102 , in step S 105 the difference between the current time and the start time is acquired as the elapsed time, and if the elapsed time is at least a specific value, it is determined that a watertight state is being maintained.
(I) In the above embodiment, the watertightness detector 115 displayed the determination result on the liquid crystal monitor 60 as the method for notifying the user of the result of determining watertightness, but the present invention is not limited to this. For example, in step S 106 the watertightness detector 115 may notify the user of whether or not a watertight state is being maintained by reproducing a sound from a speaker or the like. In this case, no sound is reproduced if the status is normal, and a certain sound may be reproduced only if there is a problem (if a watertight state is not being maintained).
Thus, the present invention of course includes various embodiments and the like that are not discussed herein. Therefore, the technological scope of the present invention is not limited to just the specific inventions pertaining to the appropriate claims from the descriptions given above.
General interpretation of Terms
In understanding the scope of the present disclosure, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Also as used herein to describe the above embodiment(s), the following directional terms “forward”, “rearward”, “above”, “downward”, “vertical”, “horizontal”, “below” and “transverse” as well as any other similar directional terms refer to those directions of a electronic device and an imaging device. Accordingly, these terms, as utilized to describe the present invention should be interpreted relative to a electronic device and an imaging device.
The term “configured” as used herein to describe a component, section or part of a device includes hardware and/or software that is constructed and/or programmed to carry out the desired function.
The terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed.
While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, the size, shape, location or orientation of the various components can be changed as needed and/or desired. Components that are shown directly connected or contacting each other can have intermediate structures disposed between them. The functions of one element can be performed by two, and vice versa. The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
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An electronic device is provided that includes a housing, a waterproof air-permeable membrane, a door, an air pressure gauge and a watertightness detector. The housing defines an opening and includes an air vent. The waterproof air-permeable membrane blocks off the air vent. The door is shiftably coupled to the housing and movable between a first position that uncovers the opening and a second position that covers the opening. The door and the housing form a watertight structure when the door is in the second position. The air pressure gauge is disposed inside the watertight structure. The watertightness detector is configured to determine whether the housing and the door have maintained a watertight state based on changes in the air pressure inside the watertight structure when the door moves from the first to the second position. The changes in the air pressure are measured by the air pressure gauge.
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PRIORITY
This application is a continuation of co-pending U.S. application Ser. No. 12/209,860, filed on Sep. 12, 2008, which is incorporated by reference herein in its entirety and is a continuation of U.S. application Ser. No. 10/747,583, filed on Dec. 29, 2003, which is also incorporated herein by reference in its entirety.
BACKGROUND
This application is related, generally and in various embodiments, to systems and methods for reordering checks for customers.
When a customer of, for example, a financial institution begins to run out of checks, the customer traditionally has had several ways to order another supply of checks. For example, many customers travel to a branch office of the financial institution and place the order with a branch office employee, or call a customer contact center of the financial institution and place the order with a customer contact center employee. However, reordering checks in either of the above-described ways is not an efficient use of the customers' or the employees' time, and relies on the customer to initiate the check reorder.
Another way to reorder checks is for the customer to access a check reorder website to place an order for an additional supply of checks. The customer can place the order by providing and submitting certain information such as the account number, routing number, etc. Although reordering checks in this manner eliminates the direct involvement of the employees of the financial institution, the process still relies on the customer to initiate the check reorder.
SUMMARY
In one general respect, this application discloses embodiments of a method for reordering checks for a customer. According to various embodiments, the method includes ordering a first quantity of checks for the customer, tracking usage of the first quantity of checks, and ordering a second quantity of checks for the customer when a predetermined quantity of the first quantity of checks has been processed.
In another general respect, this application discloses embodiments of a system for reordering checks for a customer. According to various embodiments, the system includes a computing device for tracking usage of a first quantity of checks and ordering a second quantity of checks when a predetermined quantity of the first quantity of checks has been processed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a process flow of a method for reordering checks according to various embodiments; and
FIG. 2 illustrates a system for reordering checks according to various embodiments.
DETAILED DESCRIPTION
As used herein, the term “check” means any negotiable instrument drawn against deposited funds, to pay a specified amount to a specific entity upon demand.
FIG. 1 illustrates a process flow of a method for reordering checks according to various embodiments of the disclosed invention. The process begins at block 10 , where a first quantity of checks is ordered for a customer. The first quantity of checks ordered for the customer may be an initial order or a reorder of checks for the customer. The customer may be a customer of, for example, a financial institution, and the first quantity of checks may be any quantity such as, for example, one-hundred, two-hundred, or four-hundred checks. The customer may request the financial institution to order the first quantity of checks or the financial institution may order the first quantity of checks when a checking account is opened for the customer.
When the first quantity of checks is ordered, information such as the name of the financial institution, the routing number, the account number, the starting and ending check numbers, the order quantity, and customer contact information may be provided to the entity receiving the order. Such customer contact information may include the customer's mailing address, telephone number, facsimile number, e-mail address, etc. The first quantity of checks may be printed by the financial institution or by a third-party check printer. After the first quantity of checks is printed, the checks may be delivered directly to the customer.
From block 10 , the process advances to block 12 , where the customer receives the first quantity of checks and may begin to use the first quantity of checks to draw against funds deposited with the financial institution. From block 12 , the process advances to block 14 , where the financial institution tracks the customer's usage of the first quantity of checks. To facilitate the tracking of the first quantity of checks, the financial institution may identify the customer account number and the check number for each check that has been processed. The checks may be processed by the financial institution or by a third-party processor. By tracking the usage of the first quantity of checks, the financial institution can determine a quantity of the first quantity of checks that has been processed. The quantity can be expressed in the form of a number or percentage of the first quantity of checks that has been processed.
As the usage of the first quantity of checks is being tracked at block 14 , a determination is made at block 16 as to whether or not the quantity of the first quantity of checks that has been processed has reached a first predetermined quantity. The first predetermined quantity can be individualized for each customer, and can represent a particular number or percentage of the first quantity of checks that has been processed. For example, the first predetermined quantity for a particular customer may represent 70% of the first quantity of checks. By tracking the usage of the first quantity of checks at block 14 , the financial institution can determine a difference between the first predetermined quantity and the quantity of the first quantity of checks that has been processed.
When the quantity of the first quantity of checks that has been processed reaches the first predetermined quantity, the process advances from block 16 to block 18 , where the customer is notified that a check reorder will soon be placed for the customer. The customer may be notified of the pending reorder via a notification communicated to the customer via regular mail, electronic mail, telephone, facsimile, etc.
After a determination has been made at block 16 that the quantity of the first quantity of checks that has been processed has reached the first predetermined quantity and while the usage of the first quantity of checks is being tracked at block 14 , a determination is also made at block 20 as to whether or not the quantity of the first quantity of checks that has been processed has reached a second predetermined quantity.
The second predetermined quantity is greater than the first predetermined quantity. Thus, the first predetermined quantity can be represented as a portion of the second predetermined quantity. The second predetermined quantity can be individualized for each customer, and can represent a particular number or percentage of the first quantity of checks that has been processed. For example, the second predetermined quantity for a particular customer may represent 80% of the first quantity of checks. By tracking the usage of the first quantity of checks at block 14 , the financial institution can determine a difference between the second predetermined quantity and the quantity of the first quantity of checks that has been processed. Based on the usage rate of each particular customer, the first and second predetermined quantities can be raised or lowered at any time.
When the quantity of the first quantity of checks that has been processed reaches the second predetermined quantity, the process advances from block 20 to block 22 , where a second quantity of checks is ordered for the customer. The second quantity of checks may be more than, less than or the same as the first quantity of checks. The order may be placed with the same entity that the order for the first quantity of checks was received by at block 10 . However, before placing the order, the mailing address of record for the customer may be checked to verify that the address is a valid address.
When the order is placed for the second quantity of checks, information such as the name of the financial institution, the routing number, the account number, the starting and ending check numbers, the order quantity, and customer contact information may be provided to the entity receiving the order. Such customer contact information may include the customer's mailing address, telephone number, facsimile number, e-mail address, etc. The second quantity of checks may be printed by the financial institution or by a third-party check printer. After the second quantity of checks is printed, the additional checks may be delivered directly to the customer.
From block 22 , the process advances to block 24 , where the customer is notified that additional checks were ordered for the customer. The customer may be notified of the order via a notification communicated to the customer via regular mail, electronic mail, telephone, facsimile, etc.
From block 24 , the process returns to block 12 , where the customer receives the second quantity of checks and may begin to use the second quantity of checks to draw against funds deposited with the financial institution. From block 12 , the process advances to block 14 , where the financial institution tracks the customer's usage of the second quantity of checks. To facilitate the tracking of the second quantity of checks, the financial institution may identify the customer account number and the check number for each check that has been processed. The checks may be processed by the financial institution or by a third-party processor. By tracking the usage of the second quantity of checks, the financial institution can determine a quantity of the second quantity of checks that has been processed. The quantity can be expressed in the form of a number or percentage of the second quantity of checks that has been processed.
As the usage of the second quantity of checks is being tracked at block 14 , a determination is made at block 16 as to whether or not the quantity of the second quantity of checks that has been processed has reached a first predetermined quantity. The first predetermined quantity can be individualized for each customer, and can represent a particular number or percentage of the second quantity of checks that has been processed. For example, the first predetermined quantity for a particular customer may represent 70% of the second quantity of checks. By tracking the usage of the second quantity of checks at block 14 , the financial institution can determine a difference between the first predetermined quantity and the quantity of the second quantity of checks that has been processed.
When the quantity of the second quantity of checks that has been processed reaches the first predetermined quantity, the process advances from block 16 to block 18 , where the customer is notified that another check reorder will soon be placed for the customer. The customer may be notified of the pending reorder via a notification communicated to the customer via regular mail, electronic mail, telephone, facsimile, etc.
After a determination has been made at block 16 that the quantity of the second quantity of checks that has been processed has reached the first predetermined quantity and while the usage of the second quantity of checks is being tracked at block 14 , a determination is also made at block 20 as to whether or not the quantity of the second quantity of checks that has been processed has reached a second predetermined quantity.
The second predetermined quantity is greater than the first predetermined quantity. Thus, the first predetermined quantity can be represented as a portion of the second predetermined quantity. The second predetermined quantity can be individualized for each customer, and can represent a particular number or percentage of the second quantity of checks that has been processed. For example, the second predetermined quantity for a particular customer may represent 80% of the second quantity of checks. By tracking the usage of the second quantity of checks at block 14 , the financial institution can determine a difference between the second predetermined quantity and the quantity of the second quantity of checks that has been processed. Based on the usage rate of each particular customer, the first and second predetermined quantities can be raised or lowered at any time.
When the quantity of the second quantity of checks that has been processed reaches the second predetermined quantity, the process advances from block 20 to block 22 , where a third quantity of checks is ordered for the customer. The third quantity of checks may be more than, less than or the same as the first and/or second quantity of checks. The order may be placed with the same entity that the order for the first and/or second quantity of checks was received by at block 10 . However, before placing the order, the mailing address of record for the customer may be checked to verify that the address is a valid address.
When the order is placed for the third quantity of checks, information such as the name of the financial institution, the routing number, the account number, the starting and ending check numbers, the order quantity, and customer contact information may be provided to the entity receiving the order. Such customer contact information may include the customer's mailing address, telephone number, facsimile number, e-mail address, etc. The third quantity of checks may be printed by the financial institution or by a third-party check printer. After the third quantity of checks is printed, the additional checks may be delivered directly to the customer.
From block 22 , the process advances to block 24 , where the customer is notified that additional checks were ordered for the customer. The customer may be notified of the order via a notification communicated to the customer via regular mail, electronic mail, telephone, facsimile, etc.
From block 24 , the process again returns to block 12 , where the customer receives the third quantity of checks and may begin to use the third quantity of checks to draw against funds deposited with the financial institution. The process flow sequence described in blocks 12 , 14 , 16 , 18 , 20 , 22 , and 24 may be repeated any number of times. In addition, the above described check reorder method may be performed concurrently for any number of customers.
FIG. 2 illustrates a system 30 for reordering checks according to various embodiments. The system 30 may include a first computing device 32 and a second computing device 34 in communication with the first computing device 32 via, for example, one or more delivery systems for directly or indirectly connecting the first computing device 32 and the second computing device 34 . Examples of such delivery systems include, but are not limited to, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), the Internet, an Intranet, an Extranet, the Web, a telephony network (e.g., analog, digital, wired, wireless, PSTN, ISDN, or xDSL), a radio network, a television network, a cable network, a satellite network, and/or any other wired or wireless communications network configured to carry data. Each network may include one or more elements, such as, for example, intermediate nodes, proxy servers, firewalls, routers, switches, adapters, sockets, and wired or wireless data pathways, configured to direct and/or deliver data. The first computing device 32 may be associated with the financial institution and the second computing device 34 may be associated with the financial institution or an entity such as a third-party check printer.
The first computing device 32 may be for tracking usage of a first quantity of checks and ordering a second quantity of checks when a predetermined quantity of the first quantity of checks has been processed. The computing device 32 may further be for generating a first customer notification when a predetermined portion of the first quantity of checks has been processed and for generating a second customer notification when the predetermined quantity of the first quantity of checks has been processed. The computing device 32 may further be for tracking usage of the second quantity of checks and ordering a third quantity of checks when a predetermined quantity of the second quantity of checks has been processed.
The computing device 32 may perform the above-described actions automatically and may perform the actions for any number of customers of the financial institution. Although the computing device 32 is shown as a single unit in FIG. 2 for purposes of convenience, it should be recognized that the computing device 32 may comprise a number of distributed computing devices, inside and/or outside the administrative domain.
In order to perform the actions described hereinabove, the computing device 32 may execute a series of instructions. The instructions may be software code to be executed by the computing device 32 . The software code may be stored as a series of instructions or commands on a computer readable medium such as a random access memory (RAM) and/or a read only memory (ROM), a magnetic medium such as a hard-drive or a floppy disk, or an optical medium such as a CD-ROM. The software code may be written in any suitable programming language using any suitable programming technique. For example, the software code may be written in C using procedural programming techniques, or in Java or C++ using object-oriented programming techniques.
While several embodiments of the disclosed invention have been described, it should be apparent, however, that various modifications, alterations and adaptations to those embodiments may occur to persons skilled in the art with the attainment of some or all of the advantages of the disclosed invention. For example, the usage of a particular quantity of checks may be tracked at block 14 of FIG. 1 even after the quantity of the particular quantity of checks that has been processed exceeds the second predetermined quantity, and the actions described at blocks 22 and 24 may occur concurrently. It is therefore intended to cover all such modifications, alterations and adaptations without departing from the scope and spirit of the disclosed invention as defined by the appended claims.
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Systems and methods for reordering checks for a plurality of accounts of a financial institution. For each of the plurality of accounts, an order for a first quantity of checks for the account may be generated. The order may comprise an account number and contact information. For each of the plurality of accounts, a portion of the first quantity of checks for the account that has been processed may be monitored. Also, an indication of a threshold quantity of checks may be received. Further, it may be determined when the portion of the first quantity of checks that has been processed exceeds the threshold quantity of the first quantity of checks. For each of the plurality of accounts, when the portion of the first quantity of checks that has been processed exceeds the threshold quantity, an order for a second quantity of checks for the account may be generated.
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TECHNICAL FIELD
The present invention relates generally to a method of preventing diarrhea associated with infectious agents such as rotavirus, or diarrhea associated with antibiotic therapies. More specifically, this invention relates to a powdered infant nutritional that contains the probiotic organisms Lactobacillus reuteri, Lactobacillus acidophillus and Bifidobacterium infantis. Administration of at least 10 6 CFU of each probiotic organism in a 24 hour period has been shown to be effective in the prevention of diarrhea.
BACKGROUND ART
Diarrhea is one of the most common health problems in the world, and even in developed countries is one of the most common infectious diseases. Diarrhea is also one of the most common health problems during childhood. While it has been suggested to administer fermented milk products in the treatment of diarrhea (for example rotavirus associated diarrhea), the medical community continues to seek improved methods or products which would be useful in the prevention of the disease.
In recent years, rotavirus and other enteric viruses have been identified as a major cause of acute diarrhea in infants and young children attending daycare centers. There is an acute need, both domestically and in third world countries, for products and methods that would be effective in preventing infectious diarrhea and diarrhea associated with antibiotic therapy.
Probiotics are a class of microorganisms that are defined as live microbial organisms that beneficially affect the animal and human hosts. The beneficial effects include improvement of the microbial balance of the intestinal microflora or by improving the properties of the indigenous microflora. A better understanding of probiotics in man and animals can be found in the following publications. Fuller R: Probiotics in Man and Animals, J Appl. Bacteriol 1989;66:365-365-378 and Havenaar R, Brink B, Huis In't Veld JHJ: Selection of Strains for Probiotic Use. In Scientific Basis of the Probiotic Use, ed. R. Fuller, Chapman and Hall, London UK, 1992.
The known benefits of enteral administration of probiotic microorganisms include enhanced host defense to disease, improving colonization resistance of the harmful microflora and numerous other areas of health promotion. Probiotics have been suggested to play an important role in the formation or establishment of a well-balanced, indigenous, intestinal microflora in newborn children or adults receiving high doses of antibiotics.
Lactic acid bacteria and specific strains of Lactobacillus have been widely recommended for use as probiotics. See, for example, Gilliland SE: Health and Nutritional Benefits from Lactic Acid Bacteria. Micro Rev. 1990;87;175-188 and Gorbach SL: Lactic Acid Bacteria and Human Health. Annals of Med. 1990;22-37-41. Species of Streptococci, Enterococcus, and Bifidobacteria have also been suggested as being beneficial. One of the more recently studied probiotics is Lactobacillus reuteri. This ubiquitous microorganism resides in the gastrointestinal tract of humans and animals and produces a potent, broad spectrum antimicrobial substance called reuterin. The inhibition of growth of Escherichia, Salmonella, Shigella, Listeria, Campylobacter, Clostridium and species of Staphylococcus by reuterin has been reported. See for example, Axeisson L T, et al (1989), Production of a Broad Spectrum Antimicrobial Substance by Lactobacillus reuteri, Microbial Ecology in Health and Disease 2, 131-136.
Of the intestinal lactic acid bacteria (LAB), L. reuteri is considered a major species. Due to the inability of microbiologists to distinguish L. reuteri from Lactobacillus fermenyum (L. fermetum) in the past, many researchers believe that a large percentage of LAB classified as L. fermentum in older literature, in reality, are strains of L. reuteri.
L. reuteri is a dominant heterofermentative Lactobacillus species residing in the gastrointestinal tract of healthy humans and most animals. Like other lactobacilli, L. reuteri produces acidic metabolic end-products which have considerable antimicrobial activity. It has been recently discovered that metabolism of glycerol by L. reuteri can result in excretion of a metabolic intermediate, 3-hydroxpropionaldehyde, or reuterin. See Axelsson, "Production of a Broad Spectrum Antimicrobial Substance by Lactobacillus reuteri," Microbial Ecology in Health and Disease, 2:131-136, 1989. Reuterin has been shown to have antimicrobial activity against a variety of organisms including Gram-positive and Gram-negative bacteria, yeast, molds and protozoa. See Chung, et al., "In Vitro Studies on Reuterin Synthesis by Lactobacillus reuteri," Microbial Ecology in Health and Disease, 2:137-144, 1989. It is suspected that the antimicrobial activity of reuterin contributes to the survival of L. reuteri within the gastrointestinal ecosystem.
Likewise, L. acidophilus is a normal inhabitant of the human gastrointestinal tract and is a Gram-positive rod widely used in the dairy industry. L. acidophilus is a homofermentative species, fermenting mainly hexose sugar, yielding predominantly lactic acid (85-95%). The use of L. acidophilus predates the 20th century. Bifidobacterium infantis is a Gram-positive, strictly anaerobic, fermentative rod. Bifidobacterium infantis is the predominant form of Bifidobacterium in breast fed infant feces.
Cultures of these organisms are commercially available and are usually supplied as powders. The cultures are alive but in a dormant state which is achieved by a process known as lyophilization (freeze-drying). BioGaia Biologics, Inc. of Raleigh, N.C. promotes and markets a cultured sweet milk and a fermented milk known as BRA milk™. The cultured sweet milk is made by adding to 1% pasteurized and vitaminized low fat milk a Lactobacillus reuteri, Bifidobacterium infantis, Lactobacillus acidophilus culture mixture just before filling cartons. The fermented BRA milk is similar to the cultured sweet milk except that the organisms are allowed to ferment the milk.
The feeding of Bifidobacterium bifidum and Streptococcus thermophilus to infants in hospitals is reported by Savedra, J. et al. in The Lancet, Vol. 344, Oct. 15, 1994. The feeding of these two specific organisms was shown to reduce episodes of diarrhea disease over a control (no organisms). 6.9% of the B. bifidum and S. thermophilus fed infants experienced diarrhea, while 31% of the control group experienced diarrhoeal disease.
U.S. Pat. No. 5,021,245 relates to an infant formula containing a soy polysaccharide fiber source. More specifically, this patent is directed to an infant formula used for the treatment of infantile colic. All of the data and teachings of U.S. Pat. No. 5,021,245 are incorporated herein by reference.
U.S. Pat. No. 5,234,702 relates to a powdered nutritional product which uses a specific antioxidant system to prevent the degradation of the lipid fraction. More specifically, this patent discloses an antioxidant system made up of ascorbyl palmitate, beta carotene and/or mixed tocopherols, and citrate. All of the data and teachings of U.S. Pat. No. 5,234,702 are incorporated herein by reference.
U.S. Pat. No. 5,492,899 discloses an improved enteral nutritional formula containing ribonucleotide equivalents. This patent suggests that such a formula enhances the immune system and alleviates diarrhea. The teachings and data of U.S. Pat. No. 5,492,899 are incorporated herein by reference.
One major aspect that all of the prior art fails to appreciate is the discovery that fermented dairy products, such as yogurts which contain various probiotic agents, present the consuming individual with numerous byproducts that are associated with the fermentation. One aspect of the present invention is the realization that unfermented administration of the probiotic system will be effective in preventing diarrhea. In this regard, pills or capsules containing the probiotic system according to this invention or direct administration of the probiotic powder to the individual is one embodiment of the present invention. Rehydration of the probiotic powder would occur in the patient's stomach and not allow for the fermentation byproducts to form. Thus, the present invention provides an enterally administerable product containing Lacyobacillus reuteri, Lactobacillus acidophilus and Bifidobacterium infantis in an amount which is effective to inhibit diarrhea associated with infectious agents and antibiotic therapy.
DISCLOSURE OF THE INVENTION
There is disclosed a method for the prevention of infectious diarrhea or diarrhea associated with antibiotic therapy in a human, said method comprising the steps of 1) mixing of a powder containing Lactobacillus reuteri, Lactobacillus acidophilus and Bifidobacterium infantis with a liquid and 2) enterally administering an effective amount of said liquid mixture to said human. More specifically the method should result in the administration of at least 10 6 CFU of Lactobacillus reuteri, 10 6 Lactobacillus acidophilus and 10 6 CFU Bifidobacterium infantis per day.
Also disclosed is a nutritional product in powdered form comprising protein, fat, carbohydrates, minerals, vitamins, trace elements and a probiotic system, said probiotic system comprising Lactobacillus reuteri, Lactobacillus acidophilus and Bifidobacterium infantis. In a specific embodiment the powdered nutritional product contains at least 10 5 CFU Lactobacillus reuteri per gram, 10 4 CFU Lactobacillus acidophilus per gram and 10 4 CFU Bifidobacterium infantis per gram.
The infectious diarrhea to be prevented by the present invention may be caused by any known organism that those skilled in this art would understand to cause infectious diarrhea. Such organisms include, but are not limited to: rotavirus, C. difficle, Salmonella, Shigella, Campylobacter, E. coli, Proteus, Pseudomonas, Clostridium, enteric Adenovirus, Ameoba, Staphylococcus, Ova and intestinal parasites such as Giardia Lamblia. The method and composition of the present invention is also efficacious in preventing diarrhea associated with antibiotic therapies. Those skilled in the art appreciate that antibiotic therapy for the treatment for numerous disorders and diseases results in the destruction of the intestinal microflora. This destruction of the intestinal microflora by the antibiotic results in the proliferation of pathological microorganisms. This effect of antibiotic associated diarrhea is well known in the art and readily appreciated by those skilled in this art.
The method according to this invention can also be accomplished through the administration of a powder per se or in the form of a capsule, pill or tablet which incorporates the proper level and types of probiotics disclosed herein. Also contemplated within the scope of this invention is the administration of the probiotic system in a nutritional product. This nutritional product may be, for example, powdered milk, a commercially available infant formula or powdered nutritional supplements. Thus, one aspect of this invention includes the mixing of the probiotics system with a preformed liquid nutritional product (i.e. milk or commercial infant formula). The present invention also contemplates a powdered nutritional product which may be a complete nutritional product or a nutritional supplement comprising vitamins and minerals in conjunction with the probiotic system of this invention. Thus, this invention includes powdered infant formula containing the three probiotic organisms at levels which would deliver the minimum colony forming units (CFU's) during a typical day of fecding.
More specifically, a powdered infant formula according to this invention would supply about 3.5×10 8 CFU of the probiotic blend per day. The infant formula would contain about 4×10 6 CFU of the probiotic blend per gram of formula. If one assumes that about 600 mL of formula is consumed per day, then about 7× 7 CFU of L. reuteri is consumed per day if the formula is fortified at 8×10 5 CFU of L. reuteri per gram of powdered formula.
Also contemplated in this invention is the use of the probiotic system in a nutritional supplement to prevent diarrhea. For example, Gain® nutritional beverage sold by Abbott Laboratories, is fortified with from 1.75 to 8.75×10 6 CFU per gram of each organism. If 240 mL of the probiotic supplement is consumed per day, then 1.4 to 7.0×10 8 CFU of the probiotic system is delivered to the patient per day.
There is further disclosed a method for the prevention of infectious diarrhea or diarrhea caused by antibiotic therapy in a human, said method comprising administering to said human in powdered, tablet, pill or capsule form at least 10 5 CFU Lactobacillus reuteri, at least 10 4 CFU Lactobacillus acidophilus and at least 10 4 CFU Bifidobacterium infantis per day
There is also disclosed, a method for the production of a powdered nutritional product containing a probiotic system, said method comprising dry blending a powdered probiotic system comprising Lactobacillus reuteri, Lactobacillus acidophilus and Bifidobacterium infantis with said powdered nutritional product.
One important realization that distinguishes this invention from the prior art is that the inclusion of a viable probiotic into a liquid nutritional product substantially prior to consumption will result in a fermented product. Thus, it is important that the probiotic system not be allowed to actively or substantially ferment the liquid product prior to ingestion by a human.
Those skilled in this area of technology will appreciate that for the method of the present invention, to accomplish the prevention of diarrhea, host specific microorganisms should be used.
DETAILED DESCRIPTION OF THE INVENTION
A clinical study was designed to investigate the ability of enteral administration of the probiotic system of this invention (Lactobacillus reuteri, Lactobacillus acidophilus and Bifidobacterium infantis) to prevent infectious diarrhea and diarrhea associated with antibiotic therapy. The study was conducted by adding flavor packets containing the probiotic system of the invention to a base milk just prior to consumption. Thus, the organisms did not have the opportunity to ferment the milk. This feature of administration of the probiotic system in an essentially non-cultured and non-fermented environment is an aspect of the prevention of diarrhea. Example I sets forth the manufacture of the probiotic containing packets and Example II describes the clinical study. The invention will be better understood in view of the following examples, which are illustrative only and should not be construed as limiting the invention.
EXAMPLE I
Manufacture of Probiotic System
The Bifidobacterium infantis used in this experiment is a human isolate and has been deposited with the American Type Culture Center--No. 27920. The Lactobacillus reuteri is also a human isolate and is described in U.S. Pat. No. 5,439,678. The Lactobacillus acidophilus used herein is a Gram-positive rod well known in the dairy industry. Each organism was grown separately in appropriate media and under conditions which favored viability. The fermentation patterns for each organism are known in the art and have been described previously. For Lactobacillus for example, see Silva M, et al: Antimicrobial substance from a human lactobacillus stain. Antimicrobe Agents Chemother 31:1231-1233, 1987. For cultivating strains of L. reuteri, U.S. Pat. No. 5,439,678 should be reviewed. All of the data and teachings of U.S. Pat. No. 5,439,678 are incorporated herein by reference. After fermentation and isolation using techniques known in the industry, the organisms were combined along with a carrier/cryoprotectant (whey protein concentrate) and freeze dried. Other carriers/cryoprotectants such as lactose or maltodextrin can be used. The cultures were combined using dry blending techniques and the resulting inventive culture mixture had the following concentrations:
Lactobacillus reuteri at about 5×10 10 CFU/g.
Lactobacillis acidophilus at about 5×10 10 CFU/g.
Bifidobacterium infatis at about 6-7×10 10 CFU/g.
This three part culture was manufactured and supplied by BioGala Biologics, Inc., Raleigh, N.C. and is commercially available from BioGaia Biologics.
The flavor packets for the clinical study, including a control (no probiotic system), were manufactured by dry blending the inventive culture mixture described above with sucrose and cocoa powder for the chocolate flavor pouch/packet or sucrose, dextrose and vanilla flavor for the vanilla pouch/packet using a 1.5 cubic foot V-blender to accomplish the blending. The control pouches did not contain the inventive culture mixture.
The packets were 3"×3" foil pouches containing 2.5 g. of the flavor system with or without the inventive probiotic system. Each clinical product was dry blended separately, and the preparations were stored under refrigeration until the required number of pouches had been filled and sealed, and labeled with clinical labels. The control pouches contained no detectable Lactobacillus reuteri or Bifidobacterium infantis. Completed pouches were stored refrigerated until being shipped to the clinical site in Mexico City. The flavor packets were kept refrigerated until distributed to the children's homes on a weekly basis.
The chocolate flavor packet containing the probiotic system of the present invention had 1.6×10 7 CFU L. reuteri per g; 1.9×10 7 CFU L. acidophilus per g; and 2.3×10 7 CFU B. itfantis per g in the 2.5 g flavor packet. For the vanilla flavor packets manufactured with the probiotic system according to this invention, the cultures were present at 6.35×10 6 CFU per g for L. reuteri; at 2.2×10 7 CFU per g for L. acidophihus; and 1.5×10 7 CFU per g for B. infantis. The probiotic group consumed approximately 1×10 7 to 4×10 7 CFU L. reuteri per mL in each 4-oz serving, or 10×10 9 to 5×10 9 CFU of L. reuteri per day. The total daily dose of all three cultures in the probiotic blend for children consuming the probiotic Study Feeding was approximately 2.5×10 8 CFU per mL or 3.0×10 10 CFU per day.
EXAMPLE II
Clinical Study
The following clinical study was conducted under protocol number CP-AG08 and the results were reported in a final report issued Sep. 29, 1995.
258 children living in Mexico City, Mexico were invited to join the clinical study. These children were 12 to 36 months of age and had a history of ingesting cow's milk or cow's-milk-based infant formula as part of their daily diet. Children were excluded that had a history of allergy to cow's milk; were being breast fed; had clinical evidence of chronic gastroenteritis; had clinical evidence of chronic or severe renal, liver or gastrointestinal tract function; were on immunosuppressive therapy; had taken an investigational drug within 30 days prior to enrollment or were involved in another clinical study.
Parents or legal guardians of the study subjects signed an informed consent approved by the Institutional Review Board for the Department of Infectious Diseases at the National Institute of Nutrition in Mexico City, Mexico. The investigators, staff, and parents responsible for care of the children remained blinded to the type of feedings administered to the children. The parents or legal guardians also agreed to provide the Study Feeding (base milk plus flavor packet) twice daily during the 16 week study and agreed not to give yogurt or other cultured products during the clinical trial.
The children were randomized to receive one of two Study Feedings (control vs. experimental) in a blinded, parallel, 16 week feeding trail. Randomization was stratified by age and gender. The study consisted of an entry baseline evaluation phase and the 16 week feeding phase. All children were placed under active surveillance for diarrhea during the study. At least seven days prior to beginning the trial (baseline evaluation phase) each child consumed the base study milk which was whole milk packaged in single-serving Tetra Paks (240 ml) obtained from a commercial manufacturer in Mexico City.
Parents were instructed on how to complete the monthly visit evaluation forms, how to collect fecal samples, how to mix the base study milk with the flavor packets and what to do when their child developed diarrhea.
The Study Feeding Phase began the first day the base study milk plus clinically labeled flavor packet was given and continued through day 112 or until the study ended or the child exited the study. Parents received clinically labeled color coded chocolate and vanilla flavor packets each week to mix with the base milk. Each flavor packet was mixed with 120 mL of base milk. Daily intake was recorded by the parents on worksheets.
Parents were allowed to store the packets unopened at room temperature during the week. 120 mL of base milk plus one flavor pouch was fed in the morning and another 120 mL of base milk plus flavor pouch was fed in the evening. Once mixed, the Study Feeding was consumed; any beverage not consumed within 5 hrs. was discarded. The amount of beverage consumed was recorded for each feeding. Stool samples were taken and stool characteristics were evaluated at entry and on Study Days 28, 56, 84 and 112. Diaries were used to record the child's stool patterns and tolerance.
Antibiotic use was assessed and recorded weekly by study social workers during interviews with parents. Information of the drug name, dates of use and reason for use were also recorded. The children were actively observed for diarrhea. Diarrhea was defined as an acute change in stool pattern with three or more watery/liquid stools in a 24 hr period or two or more stools than normal which were looser than normal consistency or if a child had a watery or pasty stool with blood, diarrhea was considered present.
Parents contacted the investigators when a child passed the first diarrhea stool. Records regarding number of stools and consistency were taken. Stool samples were also taken. The Study Feeding was continued during the diarrhea episode unless it interfered with the medical management of the illness. Diarrhea was tracked until the stool pattern (number and consistency) returned to normal for the child.
Also important was antibiotic use associated with any diarrhea episodes. Antibiotic associated diarrhea was defined as an episode of diarrhea that developed during antibiotic therapy or within 14 days after an antibiotic was stopped for which there was no enteric pathogens other than C. difficile (as detected by presence of C. difficile toxin) identified in the stool specimen collected during the episode.
Diarrhea stool samples were collected for evaluation of rotavirus and enteric adenovirus; for enteric pathogens; for Clostridium difficile toxin; and, selected parasites.
Statistical Methods
For continuous outcomes (percent watery stools, percent watery/loose stools, mean rank stool consistency, average number of stools per day, percent feedings, average number of feedings per day, average daily intake which were measured at several visits), repeated measures analysis of variance was employed. Values at Day 28, Day 56, Day 84 and Day 112 were responses.
The number of cases of diarrhea was analyzed by the marginal approach to multivariate survival analysis. Time to the first episode of diarrhea was analyzed by the Cox regression with the robust estimator of the variance. A multivariate Cox regression was performed comparing the number of episodes of diarrhea in the feeding groups. This analysis counts all episodes of diarrhea, including repeated episodes. The marginal approach of Lin, Wei and Weisfield was used to analyze the data. The generalized estimating equations technique is used due to the fact that some individuals have repeat episodes. We assume that the effect of the probiotic feeding is the same for first and for repeat episodes. A Cox regression analysis was also perforned for first episodes, ignoring repeat episodes. Analysis was also done for first episodes and for all episodes that occurred ≧8 days of study feeding.
RESULTS
Study Entrance Data
Two hundred fifty eight children received randomization numbers and signed informed consent to enter the study, 129 subjects in each group. The entry age ranged from 12.2 months to 36.9 months for the control group (median=23.2 months) and from 12.0 to 36.6 months for the probiotic group (median=24.0 months). The mean age of children randomized was similar across both groups. For the 243 children that entered the study and received the Study Feeding, the mean age in the control group was 24.0±0.7 months, and 24.1±0.6 months for the probiotic group. No statistically significant differences were seen in entry data for sex, age, and prior serious illness. All 243 subjects receiving the Study Feeding were placed under diarrhea surveillance (120 children in the control group and 123 children in the probiotic group).
Study Feeding Phase
Mean days on Study Feeding were 94.8±2.5 days for the control group and 95.9±2.6 days for subjects receiving the probiotic feeding. Median days on the study (111.0 days), and number of days on Study Feeding for the 75th percentile (111.0 days) and 25th percentile (97.0 days) were the same for both groups. Length of feeding for subjects who successfully completed the study ranged from 88 to 120 days. Study feeding for subjects in the control group ranged from 88 to 120 days, and from 97 to 111 days for the probiotic group.
The Study Feeding consisted of two 4-oz (about 120mL) feedings of whole milk (base milk) with added flavor packet, constituting only a minor portion of the daily caloric intake for the child. Subjects were allowed to consume regular milk in addition to the Study Feeding, and ice cream, solid foods, cheeses, juices and/or cereals were also permitted. The only restrictions were on the consumption of yogurts and other cultured products, and on the consumption of other probiotic-containing products.
Study Feeding Intake
Average daily intake was consistent for both groups (control vs. experimental) among the children consuming the Study Feeding. Intake was noted daily for all children participating in the study and total daily intake was recorded on study records.
Episodes of Diarrhea
Emphasis was given to the analysis of diarrhea episodes on Study Day 8 or later, thus subjects on the Study Feeding less than eight days were excluded. Of the 243 subjects who received the Study Feeding, four exited the study within the first seven days, all in the probiotic group. This gave 239 subjects with diarrhea surveillance beyond Study Day 7, with 120 subjects in the control group and 119 in the probiotic group.
There was a statistically significant difference between reported episodes of diarrhea occurring ≧8 days on Study Feeding for the two groups (Table 1). Among the 120 subjects in the control group with ≧8 days on Study Feeding, there were 51 reported episodes of diarrhea (0.425 episodes per subject). For the probiotic group, 33 episodes of diarrhea were reported (0.277 episodes per child) after at least 7 days on Study Feeding. Statistical evaluation by the marginal Cox Regression Analysis with robust, GEE estimate of the variance for the number of diarrhea episodes in the feeding groups was p=0.0385. The relative risk of diarrhea for a child receiving the probiotic feeding relative to the control feeding gives a point estimate of 0.592.
TABLE I______________________________________Incidence of Diarrhea Episodes AsReported By Frequency By Group ≧ 8 Days on Study Feeding Control Probiotic Total______________________________________No Episode 77 (64.2%) 90 (75.6%) 167One Episode 37 (30.8%) 25 (21.0%) 62Two Episodes 5 (4.2%) 4 (3.4%) 9Three Episodes 0 0 0Four Episodes 1 (0.8%) 0 1TOTAL 120 119 239p = 0.0385______________________________________
Diarrhea Stool Samples
There were a total of 106 episodes of diarrhea tracked during the clinical trial. Of these, 84 episodes occurred ≧8 days on Study Feeding. Rotavirus ELISA was positive in a total of 12 stool samples and for nine diarrhea samples collected for subjects with an episode ≧8 days on Study Feeding (Table II).
TABLE II______________________________________Incidence of Rotavirus (RV) Positive Diarrhea Stool SamplesFor Episodes and ≧8 Days After Study Feeding, By Group Control Probiotic______________________________________No. RV + Stool Samples 9 3No. RV + Stool Samples ≧8 7/107 2/107Days on Study Feeding forSubjects at Risk______________________________________
Antibiotic Associated Diarrhea
Six episodes of antibiotic-associated diarrhea that developed during antibiotic therapy or within 14 days after an antibiotic was stopped, and for which no enteric pathogen was identified in a diarrhea stool, were identified, all in the control group (Table III).
TABLE III______________________________________Incidence of Antibiotic Associated Diarrhea ForEpisodes ≧8 Days AfterStudy Feeding, By Group for Subjects at Risk Control Probiotic______________________________________Antibiotic Associated Diarrhea 6/120 0/119≧8 Days on Study Feeding forSubjects at Risk______________________________________
Severity and Duration
There were no statistically significant differences in the severity scores of diarrhea for episodes that occurred after ≧8 days on Study Feeding.
Antibiotic Use
No statistically significant differences were seen in frequency of antibiotic use reported between the two feeding groups. Over 70% of the subjects in both groups took an antibiotic at least once during the Study Feeding Phase.
Conclusions
The Study Feeding, whole milk with a flavor packet added, was well received by the children participating in the study. Data indicate that use of the flavor packets containing the probiotic system according to this invention and added to milk at point of consumption, was effective in preventing the onset of infectious diarrhea or diarrhea caused by antibiotic therapy. Through the work of the inventors it has been shown that the probiotic system of the present invention is efficacious and has been determined to be safe. This large clinical trial was designed to evaluate the disclosed and claimed probiotic system to determine if it is effective in reducing the incidence and severity of infectious and antibiotic diarrhea. This study has demonstrated that children consuming the inventive probiotic-containing beverage were at a reduced risk of diarrhea compared to children receiving the control beverage. Differences were statistically significant and support the efficacy of the present invention in reducing the incidence of diarrhea in children when taken as part of the daily diet.
INDUSTRIAL APPLICABILITY
The results from the clinical study demonstrate that method and formula of this invention is effective in the prevention of diarrhea. The medical community is constantly searching for methods and products that will benefit the infant and the adult. The present invention can clearly fill that need. In addition, the products useful in the method claimed herein utilizes conventional equipment and may be readily accomplished.
While the methods and products herein described constitute a preferred embodiment of this invention; it is to be understood that the invention is not limited to the precise method or formulation and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.
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A novel method for the prevention of infectious diarrhea or diarrhea caused by antibiotic therapy is disclosed. The method comprises the steps of 1) mixing a powder comprising viable cultures of the probiotic organisms Lactobacillus reuteri, Lactobacillus acidophilus and Bifidobacieriurn infantis with a liquid; and 2) enterally administering the mixture to a mammal or a human. In a preferred embodiment at least 10 6 CFU (colony forming units) of each probiotic organism is consumed per day. The invention also relates to pills or capsules containing the probiotic system (Lactobacillus reuteri, Lactobacillus acidophilus and Bifidobacterium infantis) in a freeze dried or lyophilized form. The invention also relates to a novel powdered nutritional formula for the prevention of diarrhea that comprises protein, fat, carbohydrates and the microorganisms Lactobacillus reuteri, Lactobacillus acidophilis and Bifidobacterium infantis. In a preferred embodiment the powdered nutritional formula is a nutritionally complete infant formula. A large clinical study has shown that the probiotic system according to the invention when provided in a non-fermented form is efficacious in the prevention of diarrhea. Also disclosed is a method for manufacturing the formula of the invention.
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The invention was made in the course of work supported by the U.S. Government under NIH grant no. HL42397; the U.S. Government therefore has certain rights in the invention.
This application is a continuation-in-part of Zapol, U.S. Ser. No. 07/904,117, filed Jun. 25, 1992, now abandoned, which in turn is a continuation-in-part of Zapol, U.S. Ser. No. 07/850,383, filed Mar. 11, 1992, U.S. Pat. No. 5,396,882, and of Zapol et al., U.S. Ser. No. 07/767,234, filed Sep. 27, 1991, now abandoned, which in turn is a continuation-in-part of Zapol et al., U.S. Ser. No. 07/622,865 filed Dec. 5, 1990 (now abandoned), all of which applications are herein incorporated by reference.
BACKGROUND OF THE INVENTION
The field of the invention is treatment to reduce or prevent smooth muscle contraction, especially with respect to the musculature of an organ such as a uterus or a urinary bladder.
In certain situations, notably premature labor, the uterine musculature is triggered by various stimuli to contract at a time when it is undesirable or even life-threatening to do so. If the fetus is near term but has not yet produced the surfactant that will enable it to breathe properly after birth, quieting uterine contractions and thereby delaying delivery for a few days may be sufficient: during those few days, the mother is treated with cortisol to induce immediate surfactant production by the fetus, which can then be delivered without the threat of developing the often-fatal condition known as hyaline membrane disease. In other cases, labor may begin so early in gestation that it must be controlled for weeks or even months to permit the fetus to mature in utero adequately to survive outside the womb. Present methods of preventing uterine contractions in cases of premature labor or other circumstances in which delay of delivery is desirable include mechanical suturing of the cervix (circlage) in early pregnancy, bed rest, and/or intravenous treatment with a tocolytic agent such as a β 2 adrenergic agonist (e.g., ritodrine, terbutaline, metaproterenol, albuterol or fenoterol); magnesium sulfate; ethanol; a calcium channel antagonist (e.g., nifedipine); or an inhibitor of prostaglandin synthesis (e.g., indomethacin). [Goodman and Gilman's The Pharmacological Basis of Therapeutics (7th Ed.) Gilman et al., ed.; Macmillan Publishing Co., N.Y., 1985, pages 942-943.] In addition, the use of intravenous nitroglycerin (an NO donor compound) has been reported to relax a postpartum uterus (Altabef et al., Am. J. Obstet. Gynecol. 166:1237-1238, 1992). Such drugs, however, have certain systemic side effects that may be unpleasant or harmful to the mother, and possibly to the fetus.
In an analogous manner, the often painful constrictions of urinary bladder musculature associated with the presence of an indwelling urinary catheter are typically relieved with intravenous smooth muscle relaxants that frequently cause undesired systemic effects (Resnick and Yalla, Chapter 14 in Campbell's Urology, 6th Ed., W. B. Saunders Co., 1992, pages 652-655).
SUMMARY OF THE INVENTION
The invention features methods and devices for using nitric oxide (NO) to decrease or prevent the contraction of smooth muscle in vivo. The methods involve introducing an effective amount of NO into a biological fluid which contacts the target smooth muscle, or which contacts a membrane or other biological structure adjacent to the target muscle and through which the NO can readily diffuse to reach the muscle. Because hemoglobin rapidly combines with NO, rendering it unavailable to relax smooth muscle, the biological fluid cannot be blood and preferably contains no more than trace amounts of red cells. An "effective amount" of NO is an amount which, when mixed in the volume of biological fluid which applies in a given case, gives a concentration of NO in the immediate vicinity of the target smooth muscle sufficient to cause relaxation of the muscle: i.e., a concentration preferably at least approximately 0.01 μM; more preferably between 0.1 and 1000 μM; and most preferably between 1 and 100 μM (e.g., approximately 10 μM). Where the volume of biological fluid into which the NO is diluted is small (e.g., the mucus within a non-pregnant uterus, or the fluid within an eye), a smaller absolute amount of NO will be required than where the volume of fluid is large (e.g., the amniotic fluid of a near-term pregnancy). In addition, where mixing of the NO with the biological fluid is relatively inefficient (e.g., where the fluid is relatively viscous), the rate of diffusion of NO through the fluid may be poor from the point at which the NO is introduced into the fluid to the point at which it exerts its biological effect on the musculature of the target organ, requiring a larger absolute amount of NO to achieve therapeutic concentrations in the vicinity of the muscle, or careful introduction of the NO near the location of the muscle. The concentration of NO in the source of NO, which determines the maximum equilibrium concentration of NO that can be achieved in the biological fluid, can vary widely. Gaseous NO can be provided, for example, as pure NO [10 6 parts per million (ppm)], which would give a theoretical maximum equilibrium concentration (tmec) in aqueous solution at 37° C. and at atmospheric pressure of approximately 1-2 mM. However, because NO is potentially toxic in high concentrations, pure NO may be deemed too dangerous to work with on a routine basis. Alternatively, the NO gas may be diluted in a carrier gas to between 1 to 100,000 ppm (preferably 10 to 10,000 ppm, and more preferably 100-1000 ppm), which would decrease proportionately the tmec achievable in the biological fluid (e.g., the tmec for a biological fluid exposed to 100 ppm NO at 37° C. and atmospheric pressure is 0.1-0.2 μM). Where the source of NO is a liquid into which NO has been dissolved, rather than a gas, the amount of NO in the liquid will be limited by the solubility of NO in the liquid used. Certain types of nonaqueous carrier liquids, such as those known to be capable of dissolving large quantities of oxygen (O 2 ), could carry an amount of NO some 30 times as high as the amount achievable in aqueous solutions; examples include fluorocarbon liquid such as FX-80, organic oils, organic solvents such as ethanol and glycerol, organic polymer liquids, and silicone.
One embodiment of the method of the invention is intended for decreasing or preventing the contraction of a smooth muscle in a hollow organ (preferably a non-respiratory tract organ) of an animal (e.g., a mammal such as a human), which organ contains a biological fluid which is not blood; this method involves introducing an effective amount of NO directly or indirectly into that biological fluid. By "non-respiratory tract organ" is meant an organ which does not form any part of the respiratory tract of the animal. Examples of relevant types of smooth muscle contractions in such hollow organs include uterine contractions, muscle spasms in the wall of a urinary bladder or small intestine, contractions of sphincter muscles, and vascular smooth muscle spasms of a retinal blood vessel of an eye. Where the target organ is a uterus, the uterine contraction may be associated with, for example, premature labor or uterine cramps, and the target biological fluid may be the amniotic fluid of a pregnant uterus or the mucus secretions present inside a non-pregnant uterus. Although NO would not be able to penetrate the blood-rich placenta and so cannot act on that portion of the uterus (approximately 10% of the full term uterus) which is covered by placenta, it is believed that the other structures of the uterine wall between the amniotic fluid and the uterine musculature (the amnion, chorion and decidua vera) will not present a significant barrier to the diffusion of NO from the amniotic fluid to the muscle cells. The total thickness of these structures ranges from about 1 cm at the fourth month of pregnancy to 1 or 2 mm at term (Cunningham et al., Williams' Obstetrics, 18th Edition, 1989: Appleton-Lange, Norwalk, Conn.; pages 53 and 56); NO is a small, lipid-soluble molecule that diffuses readily through cellular membranes and the interstices between cells.
The method may also be used to counter the constriction of a blood vessel the exterior surface of which is bathed by or otherwise in contact with a non-blood fluid: for example, blood vessels in the brain or spinal cord which are accessible to NO that has been introduced into the cerebrospinal fluid. This method is particularly useful for reversing vascular smooth muscle spasms associated with transient ischemic attacks (TIA), reperfusion injury, infarction, stroke, or migraine headaches. Likewise, NO introduced into amniotic fluid would dilate both placental (fetal) and uterine (maternal) blood vessels by relaxing the vascular smooth muscle contacted by the amniotic fluid, thus enhancing both fetal gas transport and maternal perfusion to the uterus.
The NO may be dissolved in a pharmaceutically acceptable carrier liquid prior to introduction into the biological fluid of the target organ, and then injected directly into the organ to mix with the biological fluid present therein. Carrier liquids that would be useful for this purpose include standard saline solutions, aliquots of the biological fluid extracted from the organ and mixed ex vivo with NO, and liquids such as fluorocarbons or organic solvents [in which NO exhibits a high level of solubility (Shaw and Vosper J. Chem. Soc. Faraday Trans. 1. 73:1239-1244, 1977; Young, Solubility Data Series 8:336-351, 1981), so that a large concentration of NO can be delivered in a small volume of carrier]. The liquid may alternatively contain a polymerizable compound such as silicone (dimethylsiloxane) or a plastic (e.g. acrylate resin); when such an NO- and polymerizable compound-containing liquid is mixed, just prior to injection, with a reagent which catalyzes the polymerization of the compound, it remains liquid during the injection process, but then forms within the target organ a spagetti-like solid that is too bulky, for example, to be ingested by a fetus. NO slowly diffuses out of the solid, which acts like a reservoir of NO constantly replenishing the supply of NO within the organ.
Alternatively, a pharmaceutically acceptable solid material [such as small plastic pellets or an intrauterine device (IUD)] may be impregnated with NO (e.g., by exposure to NO gas), and then injected or otherwise implanted into the target organ. As above, the solid material acts as a reservoir or source of NO to maintain a desired concentration of NO in the biological fluid inside the target organ.
Another means for introducing NO into the target organ is by injecting it in its gaseous state: either as pure NO gas, or NO in a mixture of gases including one or more pharmaceutically acceptable carrier gases. The carrier gas is preferably carbon dioxide (CO 2 ), which will readily dissolve in the biological fluid with no harmful physiological effects, but may instead be another relatively inert gas such as nitrogen (N 2 ). The carrier gas preferably is not pure oxygen (O 2 ), which rapidly combines with NO to form toxic nitrogen dioxide (NO 2 ).
Rather than injecting or implanting the source of NO directly into the target organ, one can utilize the ability of NO to diffuse across a gas-permeable material. Examples of such materials include gas-permeable membranes such as those used in blood oxygenators (e.g., dimethylpolysiloxane or polyalkylsulfone), and microporous materials such as Gore-tex™ or Celgard™, which allow gas molecules such as NO to pass through its micropores to dissolve in liquid. In preferred embodiments, a section of this material is configured with one face in contact with the biological fluid and a second face in contact with a source of NO, separating the fluid from the source of NO but permitting individual molecules of NO gas to pass through and diffuse into the fluid. This can be accomplished in various ways. For example, an inflatable "balloon" (such as the balloon on a Foley catheter) made of a gas-permeable material can be inserted into the organ and inflated with an NO-containing gas or liquid. Alternatively, a hollow tube or fiber (e.g., a "capillary") constructed of a gas-permeable material can be inserted into the target organ so that the exterior surface of the capillary is in contact with the biological fluid within the organ, while the lumen of the capillary is filled with or in communication with a source of NO. Possible sources of NO include a pressurized mixture of gases including NO; a liquid (such as a fluorocarbon) in which gaseous NO is dissolved; and an aqueous solution of an NO-donor compound that can spontaneously decompose in aqueous solution to release NO into the solution, including but not limited to S-nitroso-N-acetylpenicillamine, S-nitrosocysteine, nitroprusside, nitrosoguanidine, and Na(O 2 N 2 --NEt 2 ). When an aqueous solution of such a compound is used as the source of NO, the gas-permeable material is preferably one which is permeable to NO but not to the NO-donor compound itself, since it is desirable to prevent the risks (e.g., systemic vasodilation, decreased blood pressure, and lung edema) potentially associated with systemic distribution of such NO-donor compounds.
The NO-containing gas or liquid is passed through the capillary, permitting NO to diffuse directly into the biological fluid in situ. By adjusting the concentration of NO in the source gas or liquid, the concentration of NO in the target biological fluid and the resulting biological effect on the target organ can be tightly controlled. If desired, the flow of NO-containing perfusing gas or liquid can be halted, or the NO temporarily removed from the perfusing gas or liquid, allowing the NO present in the target organ to dissipate gradually with the device still in place and ready to resume immediate treatment as needed.
Alternatively, the procedure can be carried out ex vivo, with a portion of the biological fluid (1) periodically (tidally) or continuously withdrawn from the target organ, (2) contacted with a section of gas-permeable material (e.g., a capillary or cluster of capillaries) through which NO passes from a source of NO, and (3) returned to the organ via a needle or catheter. The invention thus also includes a device for carrying out these procedures, which device includes (a) a source of NO; and (b) a section of gas-permeable material having a first and a second face, the first face being configured to be placed in contact with the biological fluid and the second face being in communication with the source of NO, the section of material separating the fluid from the source of NO but permitting NO to diffuse through the material from the second face to the first face. If the section of gas-permeable material is in the form of a capillary or cluster of capillaries, the device may be configured to have the fluid contact the outside of the capillary and the source of NO within the capillary, or vice versa. The section of gas-permeable material may be configured to be implanted directly in the target organ, with the first face in contact with the fluid within the organ; or it may be configured to be utilized ex vivo, with the first face in communication with the lumen of a tube through which the biological fluid can be drawn out of the target organ and into contact with the first face; the latter device would include a mechanism such as a syringe or pump for accomplishing this drawing action, and would preferably also include a mechanism for returning the biological fluid to the organ either via the same tube through which it was withdrawn from the organ, or through a second tube, after the fluid has contacted the gas-permeable material. The source of NO may be a liquid or a gas; if a gas, the device preferably includes a mechanism such as a valve for controllably releasing the NO-containing gas mixture to contact the gas-permeable material.
The invention also includes an implantable device such as an IUD which contains an NO-releasing compound such as S-nitroso-N-acetylpenicillamine, S-nitrosocysteine, nitroprusside, nitrosoguanidine, Na(O 2 N 2 --NEt 2 ), nitroglycerine, isoamyl nitrite, inorganic nitrite, azide, or hydroxylamine, which compound is held within a chamber (e.g., the lumen of a tube) having a wall made of a solute-permeable material (for example, cellulose acetate) that permits the NO-releasing compound to dialyze or diffuse slowly out of the chamber into the fluid of the organ in which the device is implanted. The NO-releasing compound may be stored in the chamber in its dry (i.e., powdered or crystalline) state, or may be in aqueous solution. Upon decomposition of the NO-releasing compound (either spontaneously or as the result of contact with endogenous enzymes or other biological molecules present in the fluid of the organ), NO released by the NO-releasing compound acts on the smooth muscle in the organ just as in the embodiments described above. The target organ for this particular embodiment of the invention is preferably an organ having a relatively small total volume of non-blood biological fluid: e.g., a non-gravid uterus, urinary bladder, ureter, or a portion of the gastrointestinal tract. Although this embodiment of the invention results in the presence of an NO-releasing compound in the biological fluid, with the potential for uptake of the compound into the circulatory system, systemic effects resulting from such uptake, if any, will be minimal. This is because the total volume of biological fluid of the target organ is relatively small (i.e., less than a liter, and preferably less than 0.5 liter), so a high concentration of the NO-releasing compound can be achieved in the target organ with a relatively small amount of the NO-releasing compound. The larger the volume of fluid in the organ, the greater the amount of NO-releasing compound that must be used to achieve a therapeutic concentration, and the greater the potential for uptake of significant amounts into the bloodstream. This device will also be useful for reversing or preventing vasoconstriction in an organ containing a non-blood biological fluid, again provided that the total volume of such fluid in the target organ is relatively small, to keep the effects local.
The methods and devices of the invention offer a number of advantages over standard means of controlling smooth muscle contraction. In the standard treatment, the intravenous drugs used (e.g., β 2 agonists and, very recently, nitroglycerine) act systemically, introducing undesirable side effects such as diffuse vasodilation with a concomitant drop in blood pressure to possibly dangerous levels, rapid heart beat, and lung edema. While NO can act as a potent smooth muscle relaxant, as has been shown in numerous in vitro studies and in the in vivo studies on lungs disclosed in Zapol et al., U.S. Ser. No. 07/622,865 now abandoned, and Ser. No. 07/767,234, now abandoned, its biological effects are solely local ones, because any NO which enters the bloodstream is immediately inactivated by reaction with hemoglobin. Furthermore, the method of the invention induces an immediate relaxation of the target muscle as soon as it is contacted with NO, a response which can be readily and minutely calibrated by adjusting the amount of NO delivered into the target organ at any given time; this response can be maintained as long as the NO supply is maintained, and discontinued soon after treatment is withdrawn, without long-term effects. The biological effects of NO can therefore be precisely controlled both temporally and with respect to their intensity and their site of action within the patient.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiments, and from the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a diagrammatic cross-sectional view of an extracorporeal gas dialyzer unit that is one embodiment of the device of the invention.
FIG. 2 illustrates a diagrammatic cross-sectional view of a device for delivering NO to a urinary bladder.
FIGS. 3A and 3B illustrate two diagrammatical cross-sectional views of an intrauterine device (IUD) for delivering NO to a non-pregnant uterus.
EXAMPLE 1
Shown in FIG. 1 is an extracorporeal gas dialyzer unit 1 with a tube 2 connecting a needle 3 and a housing 4, which housing defines a chamber 5 containing a bundle of interwoven microporous capillaries 6 having an inlet port 7 and an outlet port 8. Chamber 5 is in communication with the lumen of barrel 9 of a syringe pump 10. Needle 3 is placed with local infiltration anesthesia across the abdominal wall 11 or via the cervix into the amniotic sac 12 within the uterine cavity 13 of a pregnant patient, to provide access to the amniotic fluid 14. Outward movement of the plunger 15 within barrel 9 of syringe pump 10 creates a partial vacuum within barrel 9, which causes amniotic fluid to be withdrawn via needle 3 and tube 2 into chamber 5. A source of NO gas 16 is connected via reducing valve 17 and tube 18 to inlet port 7. Opening valve 17 permits a stream of NO 19 to travel through tube 18, entering the capillaries 6 at inlet port 7 and exiting at outlet port 8 as waste gas (which can be scavenged, for example, by being emptied into an open reservoir chamber 23 that is aspirated by a nozzle 24 attached to a vacuum line 25). During its passage through the capillaries 6, some of the NO diffuses through the gas-permeable material of the capillary walls 20, and into the amniotic fluid 21 in contact with the capillaries 6. The direction of movement of plunger 15 is then reversed, thereby applying pressure that forces the NO-rich amniotic fluid 21 out of chamber 5, returning it to the uterine cavity 13 through tube 2 and needle 3. This procedure is repeated as many times as are necessary to achieve the desired concentration of NO in the amniotic fluid within the uterine cavity, and may be continuously performed for as long as the patient's condition dictates. Typically, unit 1 will be sized to withdraw approximately 10-20 ml of amniotic fluid 13 with each repetition, and each repetition will take approximately 5 sec to perform. Movement of the plunger 15 may be accomplished manually or by motorized means; where many repetitions are envisioned, generally only the latter will be practicable. The concentration of NO in the gas stream 19 may be varied as desired, with a higher concentration (e.g., 10 4 -10 6 ppm) producing a higher concentration of NO in the biological fluid, resulting in a more rapid and profound relaxation of the uterine musculature than will a lower gaseous NO concentration (e.g., 10 0 -10 3 ppm). The gas-permeable material may be a microporous material made of a polymer such as tetrafluoroethylene (Teflon™) or polypropylene, manufactured in a way that generates submicroscopic pores (e.g., approximately 20 Å) in the polymer. Such microporous materials are available commercially (e.g., Gore-tex™, available from Gore Assoc., Inc., and Celgard™, available from Celanese Corp.). Alternatively, the gas-permeable material may be a membrane formed from a synthetic polymer such as thin (e.g., 5 micron) silicone rubber, which permits gases such as NO to diffuse through it not by means of static pores, but rather by thermal rearrangement within the polymer itself. Diffusion through such membranes takes place as follows: A molecule of NO dissolves in the membrane at the side of the membrane in contact with the gas phase; it then diffuses through the membrane to the other side (the side in contact with amniotic fluid) through a process that depends on the formation of "channels" in the polymer network due to thermal agitation of the chain segments; and finally the NO is desorbed into the fluid. These and other materials which allow the diffusion of NO into the fluid phase of the device may be formed into hollow fibres for use as the capillaries 6; such hollow fibres are widely used in such applications as extracorporeal membrane oxygenators, which maintain blood oxygen and carbon dioxide levels during open heart surgery. Typically the capillaries are interwoven to increase turbulence and mixing in the fluid flowing over them, thereby increasing the efficiency of gas transport into the fluid.
The syringe pump 10 and housing 4 can be constructed of any standard material suitable for such applications, such as glass, plastic, or noncorrosive metal, or a combination thereof, and the needle 3 would preferably be of a size suitable for aspirating amniotic fluid, e.g., 16 or 18 guage, optionally fitted with a catheter. Although causing the gas phase to flow through the interior of the capillaries 6 and the amniotic fluid to flow around them is the preferred arrangement, the device may alternatively be designed to direct the fluid through the capillaries 6 and the gas into the space around the capillaries 6. Particulate matter in the amniotic fluid can be prevented from entering the chamber 5 by placing a filter (50-200 micron pore size) in tube 2.
EXAMPLE 2
Illustrated in FIG. 2 is an indwelling Foley catheter adapted to deliver NO into a urinary bladder, for treatment or prevention of inappropriate constriction of the bladder musculature (detrusor hyperactivity) or the ureters: for example, the painful bladder muscle (detrusor) spasms sometimes experienced by paraplegic patients or ureteral spasms after ureteral surgery. As shown in FIG. 2, the catheter unit 100 has a tube 101 for withdrawal of urine 102 from the bladder cavity 103 through the urethral orifice 104. The tube 101 is held in place in the bladder cavity 103 by means of an attached inflatable balloon 105 having a gas-permeable wall 106 defining a chamber 107. A second tube 108 in communication with a positive pressure source of NO-containing gas or liquid 109 opens into the chamber 107 of the balloon 105, permitting NO-containing gas or liquid 109 to flow through tube 108 and out opening 110 into the balloon chamber 107. Excess gas or liquid 111 exits balloon 105 by flowing into opening 112 of a third tube 113, to be discarded or recycled as appropriate. In order to maintain balloon 105 in an inflated state, the gas or liquid 111 exits from tube 113 under positive pressure (e.g. 30 cm H 2 O) via a positive pressure check valve 114. Some NO present in the gas or liquid 109 in chamber 107 passes through the gas-permeable wall 106 into the urine 102 that is in contact with wall 106, and then diffuses through the urine 102 to the bladder or ureter wall 115. When removal of unit 100 from bladder cavity 103 is desired, balloon 105 is deflated by stopping the flow of gas or liquid through tube 108 and disconnecting the positive pressure check valve 114, then extracting, through tube 113, any residual gas or liquid 109 present in chamber 107. The device 100 can be placed in a patient's bladder via the urethra, or directly in the bladder via a cystotomy.
EXAMPLE 3
FIGS. 3A and 3B illustrate one embodiment of the intrauterine device (IUD) of the invention: FIG. 3A is a cross section of the device 200 as it appears following insertion into a non-gravid uterus, while FIG. 3B indicates the conformation of the same device prior to insertion into a uterus.
As shown in FIG. 3A, device 200 includes a double lumen tube 201 enclosing a septum 202 defining two continuous channels, an inlet channel 203 and an outlet channel 204, which channels communicate at end 205. Tube 201 is closed at end 205. At end 206, inlet channel 203 is in communication with an inlet tube 207 having an injection tip 208 shaped to permit ready injection of a liquid into the lumen of inlet tube 207. When an NO-containing liquid or gas 209 is injected (e.g., by syringe) into injection tip 208, the liquid 209 flows through inlet tube 207 and into inlet channel 203. At end 205 the liquid 209 enters outlet channel 204, flowing through outlet channel 204 and then through outlet tube 210, which is in communication with outlet channel 204. The liquid 209 then exits outlet tube 210 at opening 211, and can be discarded or collected as desired. The walls of tube 201 have a gas-permeable face 212 through which NO can pass. When the NO-containing liquid 209 passes through the inlet channel 203 and outlet channel 204, NO present in the liquid 209 passes through the gas-permeable face 212 and into the surrounding uterine environment 213. A curved shape 214 is imposed on device 200 by a sleeve 215 running the length of tube 201, which sleeve is made of a flexible plastic having a "memory" for the curved shape 214.
FIG. 3B shows the same device 200 prior to insertion into a uterus. A rigid rod 216 inserted into the lumen of sleeve 215 forces the device 200 into a straight, extended conformation 217 suitable for insertion through a cervix and into a uterine cavity. Withdrawing rod 216 from sleeve 215 permits sleeve 215 to revert to the curved shape 214 as shown in FIG. 3A, which shape helps prevent device 200 from being expelled from the uterus.
Other Embodiments
Other embodiments are within the claims below. For example, the source of NO can be an aqueous solution of an NO-donor compound (such as S-nitroso-N-acetylpenicillamine, S-nitrosocysteine, nitroprusside, nitrosoguanidine, Na(O 2 N 2 --NEt 2 ), nitroglycerine, isoamyl nitrite, inorganic nitrite, azide, or hydroxylamine) which is sealed inside the device prior to implantation into the target organ. Furthermore, the target organ can vary widely. Organs appropriate for treatment with the methods and devices of the invention are ones in which the target smooth muscles are bathed with a non-blood biological fluid, such as urine, mucus, cerebrospinal fluid, or digestive juices, which fluid preferably contains no more than trace amounts of red blood cells. The usefulness of the method of the invention for relaxing the smooth muscle in the wall of a given hollow organ can be easily tested by the following means:
The internal hydrostatic pressure in the organ is measured by standard means (e.g., strain guage and catheter) well known to those skilled in the art. Baseline contractions would be induced by pharmacologial means (e.g., i.v. pitocin to contract a uterus; i.v. methacholine to contract a bladder; or i.v. cholicystokinin to contract a gallbladder). The organ would then be treated with escalating doses of NO by adding an NO-containing liquid or gas directly to the interior fluid, or by inserting a balloon into the lumen of the organ, and inflating the balloon with an NO-containing liquid or gas. At each dosage level, contractions would be induced as described above. The peak pressure of the contractions should be markedly reduced in the presence of NO compared to in the absence of NO, since the musculature of the target organ will be relaxed by NO treatment.
If relaxation and vasodilation of the vascular smooth muscle of a target organ is the desired response, then blood flow to the organ can be measured at baseline and then again after treatment with NO as above, at which point the blood flow should have increased. The preferred method of measuring regional organ blood flow is by serial left atrial injections of radiolabelled microspheres, as described in Zapol et al. (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 47:968-973, 1979).
Where the target organ is within the gastrointestinal tract, treatment can be as follows:
Regions of the stomach, small intestine or colon that can be reached by a tube with radiologic or fiberoptic guidance can be perfused with an NO-containing solution. This would distend the stomach, intestine or bowel with an NO-containing solution that would both vasodilate and reduce contractions of the target muscle. A standard double lumen nasogastric tube could be employed, injecting and continuously draining NO-containing saline. Alternatively, a fill-and-clamp technique with intermittent drainage can be used. The NO-containing fluid can be localized in a given portion of the gastrointestinal tract (e.g., a portion of the bowel that is in spasm, or in the vicinity of a constricted sphincter) to permit local effects where desired. This localization can be accomplished, for example, by the use of inflatable balloons strategically located on the double lumen nasogastric tube, which balloons act to trap the NO-containing liquid in a defined region of the gastrointestinal tract, or by injecting the NO-containing liquid into the desired region via the lumen of a fiber-optic gastroscope or colonoscope. Alternatively, a long, tubular modification of the urological balloon catheter described above (and shown in FIG. 2) could be placed at a desired point in the G.I. tract (e.g., in the bowel), and then inflated with an NO-containing liquid or gas, permitting NO to diffuse through the gas-permeable wall of the balloon and into the bowel lumen. The method of the invention is useful for reversing vasoconstriction, thus augmenting blood flow and protecting against ischemic bowel injury resulting from vasoconstriction within the G.I tract. It is also useful for dilating constricted bowel regions and thereby preventing spasm, contractions, and cramping pain: for example, in regional enteritis, colitis, etc. The mucosa lining the target gastrointestinal organ, like the mucosa lining the repiratory system (Zapol et al., U.S. Ser. No. 07/767,234 now abandoned) should not present a significant barrier preventing diffusion of NO into the organ's musculature.
The method can also be adapted for treatment of vasoconstriction in the eye, as is sometimes observed following eye surgery, or in central nervous system or spinal blood vessels. NO can be directly introduced into the cerebrospinal fluid or the fluid of the eye by any appropriate means: e.g., by injection of an NO-containing liquid, or by implantation of a gas-permeable capillary that is perfused with NO-containing gas or liquid, or by tidal aspiration and equilibration with NO gas. As noted previously, treatment in accordance with the invention should have no systemic effects, since any NO taken up by the blood would be bound by hemoglobin and thus inactivated.
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Methods and devices for using nitric oxide (NO) to decrease or prevent the contraction of a smooth muscle in a non-respiratory-tract organ of an animal, the organ being one which contains or is surrounded by a biological fluid which is not blood, which method includes the step of introducing an effective amount of NO into the fluid.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation patent application of U.S. patent application Ser. No. 10/420,303, filed Apr. 22, 2003, which claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 60/378,208 filed May 6, 2002, the entire disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] In the beginnings of drilling for oil and other hydrocarbon resources, a relatively vertical well was drilled into the earth's surface and whatever pockets of fluid were encountered would be produced at the surface. This includes different phases of desired hydrocarbons, water, etc. Many times only a single component of the formation reserve is desired to be produced and it is costly and time consuming to separate the produced fluids into the constituent components thereof once they have been intermingled. In order to alleviate the need for separation, the art has learned to separate zones of production into smaller sections. This can be done in a number of ways including by gravel packing and packing off different sections. After a gravel packing operation, fluids can only enter the wellbore through a holed base pipe in a particular section where those fluids were produced from the formation. One of the problems associated with controlling these individual zones is that the gravel pack (or other downhole arrangement) tends to restrict the I.D. of the tubing string making it difficult to install a valve at that location. Installation of valves uphole of the gravel pack has been limited to two for a significant period of time as there has been no way to control more zones through valves located uphole of the gravel pack.
SUMMARY
[0003] Disclosed here is a production control system having a series of nested tubular members including at least one axial flow channel and at least two annular flow channels.
[0004] At least one valve configured and positioned to control flow from each flow channel is provided.
[0005] Further disclosed herein is a production apparatus having a series of nested tubulars connected to one another such that at least an axial flow channel and at least two annular flow channels are formed.
[0006] A valve is associated with each of the flow channels and is configured and positioned to independently control flow from each of the flow channels.
[0007] Further disclosed herein is a method for controlling commingling of flows from multiple zones. The method includes physically containing flows from different zones to individual concentric flow channels in a nested tubular arrangement and selectively commingling one or more of the flows by setting at least one valve associated with each flow channel to a closed position one of an infinite number of flow capable positions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Referring now to the drawings wherein like elements are numbered alike in the several Figures
[0009] FIG. 1 is a schematic cross sectional view of a multiple zone downhole intelligent flow control valve system.
DETAILED DESCRIPTION
[0010] A multiple zone downhole intelligent flow control valve system is illustrated generally at 10 in FIG. 1 . One of ordinary skill in the art will recognize the appearance of a well system wherein a section of the casing is illustrated at 12 . Illustrated downhole of the casing section are three distinct production zones 14 , 16 and 18 , respectively. Each zone is schematically illustrated. The individual zones are delineated with packers 20 , 22 and 24 as well as discrete screen sections 26 , 28 and 30 , although it should be understood that a single extended screen section could replace the individual screen sections without changing the function of the device. Extending downhole through the screen sections as identified are two pipes 32 and 34 of different lengths. It will be noted that pipe 32 is smaller than pipe 34 in diameter and is the pipe that extends farther downhole than pipe 34 . Pipe 32 includes an annular packer 36 (or seal) which is nested with packer 20 . Pipe 34 ends with a packer 38 (or seal) nested with packer 22 . This, as is illustrated in the drawing, creates three individual flow channels for produced fluid. The fluid from zone 14 flows up the I.D. of pipe 32 . The fluid produced from zone 16 flows through the annular space between pipe 32 and pipe 34 and the fluid produced from zone 18 flows in the annular space defined by pipe 34 and screen section 30 . By so segregating the fluids, each zone of produced fluid enters the cased section 12 of the wellbore separated from each other fluid. Each of these fluids may then be controlled before commingling.
[0011] In order to provide control over all three fluid streams, three separate valves are supplied within the casing segment area 12 . Extending radially outwardly from a seal 40 at pipe 34 is shroud 42 . Shroud 42 is employed to maintain the fluid produced from zone 18 distinct from the fluids produced from zones 16 and 14 . It will be understood that fluids from zones 14 and 16 are separate until and unless mixed in a space defined by shroud 42 by virtue of valves 44 (pipe 34 ) and 46 (pipe 32 ) being open. Within shroud 42 , valve 44 is connected to pipe 34 to regulate fluid therefrom. Pipe 32 extends through the I.D. of valve 44 and up to a valve 46 which controls fluid production from zone 14 and pipe 32 . Each valve 44 and 46 , when open, dumps fluid into shroud 42 and through a holed pipe section (or a valve as desired) 48 (illustrated as holed pipe section). It will be appreciated by those skilled in the art that a plug 49 is installed in pipe 32 immediately uphole of valve 46 to prevent flow of fluid therepast in the lumen of pipe 32 . Were it not for plug 49 , pipe 32 would be contiguous with tubing 50 .
[0012] Fluid flowing through holed pipe section 48 enters production tubing 50 to continue movement uphole. Fluid produced from zone 18 and moving through an annular space defined by shroud 42 at the inside dimension and by casing segment 12 at the outside dimension, moves through valve 52 , if open, to join the fluid produced through holed pipe section 48 . One of ordinary skill in the art will appreciate that valve 44 allows or prevents fluid production from zone 16 , valve 46 allows or prevents production from zone 14 and valve 52 allows or prevents fluid production from zone 18 . This is multizonal control where valve structures are maintained in a casing segment of larger diameter uphole of a gravel pack section. A well operator can therefore selectively close any or all of, and in each permutation thereof, valves 44 , 46 and 52 to produce any combination of the flow streams including a single stream, a combination of streams or all or none of the streams emanating from the formation. Each of the valves as described above may be actuated hydraulically, pneumatically, electrically, mechanically, by combinations of the foregoing and by combinations including at least one of the foregoing etc. either by surface intervention or by intelligent systems in a downhole environment or uphole. Where intelligent completion systems are employed, at least one sensor would be installed (schematically illustrated as 60 , 62 and 64 ) in each of the producing zones and in each of the valve sections such that parameters such as pressure, temperature, chemical constitution, water cut, pH, solid content, scale buildup, resistivity, and other parameters can be monitored by surface personnel or at least one controller whether surface or downhole controllers or both, (surface or downhole controller schematically illustrated in operable communication with sensors and valves) in order to appropriately modify the condition of the valves to produce the desired fluid. With appropriately programmed controllers, automatic adjustment of valves is possible and contemplated. It should also be noted that it is intended that each of the valves be variably actuatable such that pressure biases between the zones can be effectuated whereby water breakthrough can be avoided while maintaining production at an optimized level.
[0013] It should now be understood by one of ordinary skill in the relevant art, that the discussion of the apparatus/system above also presents a method for controlling the commingling of well fluids which was heretofore difficult if not impossible in certain well configurations such as multiple zone gravel packs. The method associated with the device described comprises physically containing the flows from different zones in concentrically arranged flow channels as discussed above. The flows are maintained separate until reaching a location where it is possible to valve them such that control is maintained. The method further comprises sensing the fluid parameters somewhere in the flow channel prior to reaching the valve structure in order to allow an operator or a controller to determine that a specific valve should stay closed or should be opened based upon a determination that the fluid being produced is not desired or desired, respectively. The process may be made automatic with appropriate programming for at least one controller.
[0014] While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
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A method for controlling commingling of flows from multiple zones. The method includes physically containing flows from different zones to individual concentric flow channels in a nested tubular arrangement and selectively commingling two or more of the flows by setting at least one valve associated with each flow channel to a closed position or one of an infinite number of flow capable positions.
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STATEMENT OF RELATED APPLICATIONS
This application claims priority on and the benefit of German Patent Application No. 10 2010 025 129.1 having a filing date of 25 Jun. 2010 and German Patent Application No. 10 2010 050 490.4 having a filing date of 8 Nov. 2010, both of which are incorporated herein in their entireties by this reference.
BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates to a process for producing a road covering of asphalt, in particular an asphalt surface or an asphalt road, with a road paver, with material for producing the road covering being supplied to the road paver and said material being homogenized. The invention additionally relates to a road paver, with an undercarriage, with at least one hopper, in particular at least one chamber for holding preferably at least essentially continuously supplied material, with a screed for producing a road covering, and with a conveyor for conveying material to the screed, and with a device for homogenizing the material. The invention also relates to a feeder, with an undercarriage, with at least one hopper for holding material, with a conveyor for preferably continuously supplying material from the hopper to a road paver for laying a road covering, in particular an asphalt layer or asphalt covering. The invention moreover relates to a paving train with at least one road paver, and with at least one feeder, it being possible to produce at least one road covering by the road paver, and for material for producing the surface covering to be supplied by the feeder to the road paver, preferably continuously.
2. Prior Art
Surface coverings or road structures, which can, for example, be walked or driven over, such as in particular road surfacing or road surface layers and in particular roadway pavings, are usually produced from materials such as, preferably, asphalt. So-called road pavers are generally used to produce the layer of material that is applied on top of a subsurface.
The material is usually at least essentially continuously supplied to the road paver in order to ensure an even application of material that is as uninterrupted as possible. As a buffer for short interruptions in delivery, the road paver generally has a container or hopper that is also known as a material bunker. The material is usually loaded into this hopper from a so-called feeder with the aid of a conveyor. The road paver itself usually also has a conveyor, preferably a scraper conveyor, which serves to remove material from the hopper and supply it to a screed. The screed distributes and compacts the material evenly on the subsurface. The road paver can be designed as a single-layer or multi-layer paver.
Surface coverings made from rolled asphalt are laid when they are hot. In order to ensure optimum durability of the surface covering produced, it is necessary, on the one hand, to prevent properties of the material from deviating from specifications, such as an optimum working temperature, and differences in the temperature or composition. Mixing devices are usually used for this purpose, which mix a portion of the material to provide it with uniform properties, in particular a uniform temperature, i.e. the material is homogenized before it is laid with the paver. The continuous mixing of the road-surface material entails a high level of energy consumption and causes considerable wear on the required mixing devices.
BRIEF SUMMARY OF THE INVENTION
The object of the invention is to create a process that enables an optimal quality of the road surface material while preventing high energy consumption and wear.
A process that fulfils this object is a process for producing a road covering of asphalt, in particular an asphalt surface or an asphalt road, with a road paver, with material for producing the road covering being supplied to the road paver and said material being homogenized, characterized in that specifically only such material is used for the homogenizing that deviates in at least one property from predetermined requirements. It is accordingly provided specifically to homogenize such, and preferably only such, material or road-surface material where its properties deviate from predetermined requirements or which does not have the required properties. The material to be homogenized preferably has at least one property that deviates from predetermined requirements. These can, for example, be different physical properties of the material. Meeting predetermined requirements is necessary to achieve optimum quality and durability of the asphalt road.
The material to be homogenized is preferably separated from the other material at least temporally. This means that the material or at least part of the material which deviates or deviates excessively from the corresponding properties is handled separately. It is thus ensured that the other material has at least essentially the required properties. In particular, the separated part of the material is stored apart from the other material. The material is preferably supplied to a hopper of the road paver and/or the feeder. The separated material is more preferably also supplied to a hopper of the road paver and/or the feeder. This is in particular a preferably separate hopper or an in particular separate section or area or preferably a separate chamber of the hopper. The material to be homogenized is added to the other material preferably in a metered fashion. The material to be homogenized is thus preferably deposited on the other material, in particular in layers or in a layer. The material is usually transported with the aid of a conveyor such as a conveyor belt or scraper conveyor, with the aid of which it is transported in particular as an at least essentially layer-forming stream of material. The separated material is therefore preferably deposited on this stream of material or in the region of the conveyor, or is supplied or added to it. An at least almost even spreading or mixing can thus be achieved. Homogenization thus results.
The material and/or the separated material is more preferably thoroughly mixed. The material and/or the separated material preferably passes through a mixing device to homogenize the material. At least one conveyor such as, for example, a conveying or mixing auger is provided for the thorough mixing. Alternatively, the material or the separated material can bypass the mixing device.
Provided for the homogenization of the material is in particular a preferably separate container which is filled with the material to be homogenized. An essentially cylindrical configuration of the container is particularly preferred, especially one having a conically tapering lower end. In order to minimize any heat losses, the container or cylinder is preferably equipped with at least one insulating wall for heat insulation. Positioned in the interior of the container is a mixing device, in particular a rotatably mounted and preferably centrally disposed axis or revolving axis with a plurality of in particular convex and/or concave blades. The blades in this case extend essentially from the central axis to a point near the inner wall of the container. A very preferred arrangement is one with alternating convex and concave blades disposed about the axis, preferably in a plurality of planes. When the mixing device revolves about its axis, the mixture introduced into the container is blended and thus brought to an essentially uniform temperature during the mixing process. Arranged at the lower, conically tapering end region of the container is preferably a removal device. To this end, a slide can be provided, for example, with which a desired quantity of the mix can be released from the container onto the conveyor arranged below, in particular in a continuous manner. The mixing process is preferably executed such that the mixing device, due to the varying concave and convex blade elements, which are preferably arranged in alternating fashion, forces the mix downward during the mixing process along a path which leads from the top end of the cylinder to the lower end and which directs the mix alternately inwards toward the central axis and outwards toward the container wall. In order to raise the temperature of the mixture as a whole a heating element can be additionally provided, for example in the region of the mixing device, such as in the vicinity of the blade elements or the central axis or even the container wall. The heating element can, for example, be powered by electrical means or by a gas heater, for example.
The temperature of the material is preferably regarded as a relevant value, in particular the average temperature. The material is preferably used for homogenizing depending on its temperature. Material is homogenized that at least in sections has a temperature that deviates from a reference temperature and/or that deviates from the temperature of the other material. The reference temperature or the size of the deviation from the temperature of the other material, in particular its average temperature, can be predetermined for this. A negative deviation preferably results in the separation of at least part of the material, as material temperatures that are too low can cause a reduction in the quality of the material. The material or its properties such as the temperature of the material are preferably homogenized, entailing a selective distributing or thorough mixing. This is achieved by in particular colder material being supplied again to the other material in a preferably metered fashion. However, this happens in such small amounts, or is distributed in such a way that no significant or excessive cooling of the other material is caused by the supplied material. By means of metered addition, relatively small amounts of separated and in particular colder material can thus be supplied to the other material or the stream of material for a homogenization of the temperature. In particular, the temperature of the separated material at least almost matches the temperature of the other material. A homogenization of the temperature is thus all in all achieved.
Corresponding threshold values or fixed reference temperatures are provided in order to split off or separate part of the material. Part of the material is preferably separated if the temperature of the material falls below a reference temperature. It can additionally or alternatively be provided that the temperature deviation relative to the other material, i.e. for example an average temperature of the material, is at least 5 K, preferably at least 10 K and particularly preferably at least 14 K. (Absolute temperatures are measured in degrees Celsuis, while temperature differences are measured in Kelvin herein.) This means that these deviations are present, on the one hand, relative to the reference temperature and, on the other hand, relative to the temperature of the other material. It has been shown that a deviation of more than 14 K, in particular in the form of colder areas of the material, so-called “nests”, results in a marked deterioration in the quality of the surface covering.
The temperature of the material is preferably measured by means of a measuring apparatus. The temperature is preferably measured on the road paver and/or on the feeder. The measurement more preferably takes place in the region of a conveyor and/or a hopper for the material. In particular, at least one sensor arrangement is provided with at least one sensor. An infrared sensor is preferably used as a sensor that preferably works in a non-contact fashion. The temperature of the material by sections in individual areas can thus be determined preferably by multiple sensors, preferably arranged at least essentially adjacent to one another, at a suitable distance from the material or stream of material streaming past, in particular on a conveyor. Depending on the temperature, preferably determined at different places, corresponding areas or parts of the material or stream of material can be separated by suitable means. The temperature is preferably measured as averages over flat areas of the material. This is due to the fact that each sensor monitors a specific surface area of the material. Furthermore, the creation of so-called “nests” with too low temperatures and a certain minimum size results in a marked deterioration in the quality of the road covering. The cross section or diameter of these areas is usually at least approximately 5 cm to 10 cm or even 20 cm, but sometimes can even be several decimeters. Substantially smaller nests are normally unproblematic and can accordingly be disregarded. The measuring equipment thus needs to be adapted so that correspondingly small areas are taken into consideration or ignored during the measuring. An imaging process can preferably be provided for determining the temperature distribution of the material, in particular an infrared camera with corresponding analysis.
A screed is in particular provided on the road paver, serving to apply the supplied material to a subsurface and there compact it. Moreover, a conveying means, in particular a conveying auger or distributing auger, can distribute the material at least essentially evenly over the width of the screed. A conveyor is more preferably provided which supplies the material from a storage means, in particular one of the hoppers or chambers of the screed. Alternatively, the conveyor can, for example, also be loaded directly from the feeder, in order to transport the material to the screed.
A road paver which fulfils the object of the invention mentioned at the beginning is a road paver, with an undercarriage, with at least one hopper, in particular at least one chamber for holding preferably at least essentially continuously supplied material, with a screed for producing a road covering, and with a conveyor for conveying material to the screed, and with a device for homogenizing the material, characterized in that at least one separate hopper and/or at least one separate chamber is provided for holding material for homogenizing with at least one property that deviates from predetermined requirements. Accordingly, a separate hopper is provided for holding material for homogenizing which has at least one property that deviates from predetermined requirements and/or does not have the required properties.
The feeder which fulfils the object of the invention mentioned at the beginning is a feeder, with an undercarriage, with at least one hopper for holding material, with a conveyor for preferably continuously supplying material from the hopper to a road paver for laying a road covering, in particular an asphalt layer or asphalt covering, characterized in that at least one measuring apparatus is provided for determining at least one property of the material. Accordingly, a measuring apparatus is provided in order to determine at least one property of the material.
A paving train which fulfils the object of the invention mentioned at the beginning is a paving train with at least one road paver, in particular according to the invention, and with at least one feeder, in particular according to the invention, it being possible to produce at least one road covering by the road paver, and for material for producing the surface covering to be supplied by the feeder to the road paver, preferably continuously, characterized in that a measuring apparatus is provided for determining at least one property of the material, and/or an additional hopper for holding material for homogenizing. Accordingly, a measuring apparatus for determining at least one property of the material is provided.
The following detailed embodiments or developments of the invention each relate by analogy to the road paver as well as to the feeder and the paving train.
The material which has at least one property that deviates from predetermined requirements or does not have the required properties can preferably be specifically homogenized. This means, in particular, that part of the material is split off or can be split off from the other material. Material with deviating properties is thus singled out, as otherwise the quality of the asphalt layer or asphalt overlay produced would be reduced.
At least part of the material with a temperature that deviates from a reference temperature and/or from that of the other material can, more preferably, be separated off. A separating device for splitting off or separating material is preferably provided. The separating device preferably separates material depending on its temperature. In particular, at least one preferably at least partially pivotable element or guide member is provided which serves to separate the material. This element is, in particular, designed as a guide plate, preferably as a pivotable conveyor. The stream of material can thus be directed in different directions or to different places. Accordingly, the material to be homogenized or to be separated can, for example, be directed into a separate hopper or a separate chamber of a hopper.
A hopper is preferably provided on the road paver or on the feeder for at least temporarily holding in particular the separated material or material to be homogenized, or the material for homogenizing. The material to be homogenized is preferably supplied to the other material in metered fashion and/or as a layer. The material to be homogenized can thus preferably be removed from the corresponding receptacle, in particular from the separate receptacle, in particular from one of the chambers. The hopper has at least one separate chamber, and preferably two chambers.
A conveyor such as, for example, a conveying auger or a conveyor belt or a scraper conveyor is in particular provided for the removal of material from the hopper or from the chamber. At least one conveyor, in particular a conveying auger, is more preferably provided to convey and/or mix the material and/or the separated material. The conveyor or conveyors can thus fulfill both functions jointly or separately. The conveyors can be arranged parallel and/or antiparallel to each other but can also be arranged at any angle to each other, although preferably at least almost at right angles to each other.
In the case of conveying augers, the material is preferably arranged above in a hopper or in one of the chambers. It is transported away or mixed in an essentially horizontal plane. The conveyors particularly preferably serve to add the separated part of the material to the other part of the material, in particular in a metered fashion. This ensures an even distribution of the separated parts of the material. In this way the temperature is matched to the average temperature of the other material. The separated material is particularly preferably added in layers and/or in small amounts to the other material or mixed with it. This ensures optimum heating of the added material, while the other material is only minimally cooled.
In particular, at least one measuring apparatus is provided for the in particular continuous measurement, at least in sections, of a temperature of the material and/or of the separated material. At least one sensor arrangement is more preferably provided as a measuring apparatus. The sensor arrangement has at least one sensor that works, in particular, in a non-contact fashion. The sensor is preferably an infrared sensor. Three sensors or measuring apparatus are preferably used, which are arranged in particular at least essentially linear and/or in or transverse to the conveying direction. Particularly when assuming a transverse arrangement, the measuring apparatus are distributed over the cross section of the conveyor, preferably evenly. An imaging sensor such as, for example, an infrared camera can also particularly preferably be used. It is thus possible to establish the temperature distributions and local temperature differences or maximum and minimum temperature values in the material or in the stream of material. The temperature of the material is preferably determined in the region of the conveyor. This has the consequence that, when the material is moved continuously through the conveyor and with an essentially fixedly mounted sensor, snapshots of the temperature distribution of the material at the respective point in time can be taken in a corresponding section of the material. Alternatively, the measuring apparatus can be arranged so as to be movable or pivotable. The measuring apparatus is, in particular, provided on the feeder but can also be associated, for example, with the road paver and/or with a separate vehicle having a homogenization device, or with the homogenizer.
The material can also more preferably be homogenized by a separate device for homogenizing, in particular a preferably self-propelled homogenizer. The device or the homogenizer is, to this end, associated in particular with at least one conveyor and/or at least one hopper. The material can also more preferably be brought together and/or mixed for the homogenizing. The material is preferably supplied to the road paver by a self-propelled feeder. The feeder has for this purpose in particular a conveyor, such as a conveyor belt, a scraper conveyor or the like. The material is supplied to the feeder, for example into a hopper arranged thereon or to a chamber. The conveyor transports the material from the hopper to the region of the road paver. The road paver and the feeder are constituents of the so-called paving train.
A conveyor belt, a scraper conveyor or the like preferably serves as a conveyor. Particularly preferably, the temperature or the temperature distribution is or can be determined at least in sections on the road paver and/or on the feeder and/or on a homogenizer. The road paver can be designed as a single-layer or multi-layer paver. A multi-layer paver can apply several layers of asphalt to a subsurface in a single operation.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described in more detail below with reference to the drawings, in which:
FIG. 1 shows a paving train with a road paver and a feeder.
FIG. 2 shows a perspective view of a first embodiment of a road paver with a homogenizer.
FIG. 3 shows a perspective view of a second embodiment of a road paver with a homogenizer.
FIG. 4 shows a schematic diagram of the homogenizer in FIG. 3 .
FIG. 5 shows a homogenizer according to the invention according to a third embodiment in a front view.
FIG. 6 shows a top view of the homogenizer according to FIG. 5 .
FIG. 7 shows a homogenizer according to the invention according to a fourth embodiment in a front view.
FIG. 8 shows a top view of the homogenizer according to FIG. 7 .
FIG. 9 shows a homogenizer according to the invention according to a fifth embodiment in a front view.
FIG. 10 shows a top view of the homogenizer according to FIG. 9 .
FIG. 11 shows a side view of the homogenizer according to FIG. 9 .
FIG. 12 shows a homogenizer according to the invention according to a sixth embodiment in a front view.
FIG. 13 shows a front view of the homogenizer according to FIG. 12 .
FIG. 14 shows a perspective view of the homogenizer according to FIG. 12 .
FIG. 15 shows a mixing container with a mixing device.
FIG. 16 shows a conveyor with two slatted frames.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A paving train 10 for producing a surface covering or a road of rolled asphalt conventionally comprises at least one road paver 12 and at most one feeder 14 . The road paver 12 serves to apply material supplied to it, such as, for example, asphalt, to a subsurface 38 , to distribute it more or less evenly and to compact it in a suitable manner. At least one layer-forming asphalt roadway paving is thus created.
In order to move along the subsurface 38 which is to be provided with the road covering, the road paver 12 has an undercarriage 16 , which is often designed as a tracked undercarriage with a drive, as in the present case. The road paver 12 has a so-called screed 18 at its rear end region. The material is supplied to this screed 18 in order to be evenly distributed and compacted on the subsurface 38 . A distributing auger 20 , not visible in detail here, is usually provided in the region of the screed 18 for at least coarse distribution. The undercarriage 16 of the road paver 12 stands on the subsurface 38 and not on the fresh road surface. When operating, in other words during the production of the road surface, it travels away from the edge of the road surface that has just been produced.
The road paver 12 has a hopper 22 for the material at a front end region. While the road paver 12 is operating, the material is successively removed from this hopper 22 and transported through the inner, in particular the lower, region of the road paver 12 near the ground into the region of the screed 18 . A conveyor 24 , in particular a scraper conveyor, is provided for this transporting. A drive unit 26 , which here has an internal combustion engine, is provided to drive the components, in particular the undercarriage 16 , the conveying devices etc of the road paver 12 . The road paver 12 can be controlled, in particular by manual intervention, in the region of the operating platform 28 with operating elements 30 . At least one seat 32 and one roof 34 for protection from the weather are provided for an operator.
The material is supplied to the hopper 22 by a feeder 14 . For this purpose, the feeder 14 has a conveyor boom 40 with a conveyor 42 extending along it. The conveyor boom 40 is articulated at a rear end region of the feeder 14 . A pivoting device 44 is provided for the height adjustment and lateral adjustment of the conveyor boom 40 . The pivoting device 44 can be automatically controlled, in particular pivoted, by an operator. It can thus be ensured that the material transported with the aid of the conveyor 42 lands in the hopper 22 of the road paver 12 in every case. To this end, the conveyor boom 40 tracks the road paver 12 during the process in a suitable manner. This is necessary in particular when the road paver 12 and the feeder 14 are operating together. The direction of travel 36 of the road paver 12 or the entire paving train 10 including the feeder 14 during operation, in other words when a road covering is being produced, is in the direction of the arrow of direction of travel 36 , in other words to the left in the plane of the drawing or plane of the sheet of paper in FIG. 1 .
To move, the feeder 14 has an undercarriage 46 that is designed here as a tracked undercarriage. The feeder 14 has its own drive unit 48 , typically with an internal combustion engine, as a drive for the undercarriage 46 and the different units of the feeder 14 . An operating platform 50 with operating elements 52 is provided for controlling the feeder 14 , in other words in particular the undercarriage 46 , the conveyor 42 and the conveyor boom 40 . At least one seat 54 and one roof 56 serve to improve the working conditions of the at least one operator and to protect the operating platform from the weather.
The feeder 14 has a hopper 58 at its front end region. A transport vehicle such as, for example, a lorry with, for example, a tippable loading area can pour a quantity of the material into this hopper 58 . The material is preferably removed from the hopper 58 with the aid of a conveyor 60 such as, for example, a scraper conveyor. To this end, the conveyor 60 extends from the region of the hopper 58 as far as the region of the conveyor boom 40 . The material is there reloaded onto a conveyor 42 , for example by falling down onto it. The conveyor 42 then transports the material further along the conveyor boom 40 . At its free end region with a tensioning roller 62 , it then falls down from the conveyor 42 . Because of the transporting speed of the conveyor 42 the material usually falls downwards and forwards, in the opposite direction to the direction of travel 36 , forming a parabola or arc. The free end of the conveyor boom 40 must thus be arranged at such a distance from the hopper 22 in the direction of travel 36 of the paving train 10 that the material lands on the hopper 22 on the road paver. Alternatively, a continuous conveyor can also be provided instead of the two separate conveyors 42 and 60 so that there is no need for reloading.
The pivoting device 44 usually has a hydraulic design. It can adjust the horizontal and vertical orientation or position of the free end of the conveyor boom 40 relative to the feeder 14 and thus also relative to the road paver 12 . A movable deflection member 80 , such as a guide plate, is additionally provided here at the free end of the conveyor boom 40 . This can in a simple manner move the stream of material laterally or forwards and backwards, depending on the arrangement of deflection member 80 transversely to or in the direction of travel 36 of the feeder 14 . To do this, the deflection member 80 must be pivoted or adjusted slightly.
The first embodiment of a road paver 12 according to the invention shown in detail in FIG. 2 is designed to be self-propelled and accordingly also has an undercarriage 16 . A drive unit 26 with an internal combustion engine is provided to drive the undercarriage 16 and the other components. An operating platform 28 with a roof 34 provides protection from the weather. The operating platform 28 houses operating elements 30 for an operator to control the road paver 12 .
The road paver 12 has a hopper 22 at its front end region. The hopper 22 serves, on the one hand, to hold the material or asphalt to be used as the road covering. On the other hand, the hopper 22 simultaneously serves to homogenize material by means of corresponding equipment, in other words serves as a homogenizer 72 . Guide plates 64 and 66 are arranged inside the hopper 22 and serve to deflect the stream of material inside the hopper 22 . They are particularly suited to partitioning the chamber 68 , 70 of the hopper 22 at least roughly into a left and a right half. To this end, the guide plates 64 have a roof-like design, in particular in the middle region of the hopper 22 . The laterally arranged guide plates 66 are designed as essentially plane sheets. They extend respectively along the entire length of the hopper 22 . They run obliquely downwards from the side wall 104 of the hopper 22 .
Moreover, in the lower region of the hopper 22 , two conveying augers 74 are arranged here which serve predominantly to transport or convey the material from the hopper 22 onto the conveyor 24 . At the same time, they at least partially serve to thoroughly mix the material. Because the conveying augers 74 can be controlled individually, differing amounts of the material can be transported from the left chamber 68 or the right chamber of the hopper 22 onto the conveyor 24 arranged beneath the operating-platform end of the conveying auger 74 . The conveyor 24 serves to transport the material to the rear end of the road paver 12 in the region of the operating platform 28 . The material is there applied to the subsurface by the screed 18 .
The hopper 22 here has three wheels 76 for supporting it on a subsurface 38 , so that the weight of the hopper 22 is not supported exclusively by the undercarriage 16 of the road paver 12 .
The road paver 12 described here can be operated in an alternative embodiment also as a separate, in particular self-propelled homogenizer 72 or as a homogenizing system. For this, the screed 18 is removed at the rear end of the road paver 12 and replaced by a coupling and/or an additional conveyor, in order to transfer the material to, for example, a road paver 12 or feeder 14 .
The hopper 22 of the road paver 12 can be exchanged for alternative embodiments of the hopper 22 . In particular, the different embodiments in FIGS. 3 to 6 may be considered. The description of identical constituents or components of the different embodiments is thus in part not repeated.
FIG. 3 shows an alternative embodiment of a road paver 12 according to the invention. The road paver 12 shown here essentially corresponds to that described above as the first embodiment. Only the hopper 22 has been modified.
In the present case, two chambers 68 and 70 are arranged one behind the other inside the hopper 22 , in the direction of travel 36 of the road paver 12 . The chamber 68 is designed to be significantly larger than the chamber 70 . Accordingly, the chamber 68 in the present case contains about four times more material as its volume is about four times as large. A partition wall 78 , which is arranged transversely to the direction of travel, serves to divide the hopper 22 into the two chambers 68 and 70 . Lateral guide plates 66 are arranged inside the two chambers 68 and 70 , and roof-shaped guide plates 64 are arranged in the central region, to deflect the material. In an alternative embodiment, these guide plates 64 and 66 can, however, be omitted.
The larger chamber 68 serves to hold the material that is at the correct temperature. In the smaller chamber 70 , on the other hand, the material to be homogenized or colder material is stored.
The hopper 22 or homogenizer from FIG. 3 is shown in FIG. 4 with a portion of the conveyor 24 in a schematic diagram. The conveyor 24 has a scraper belt 100 that is guided around a tensioning roller 102 . The upper section of the scraper belt 100 facing the chambers 68 and 70 moves to the left in the plane of the drawing and thus in the opposite direction to the direction of travel 36 of the road paver 12 , in other words in a running direction 86 .
It can be observed how the two chambers 68 and 70 are arranged relative to the conveyor 24 . The material from the chamber 68 is deposited on the conveyor 24 with the aid of the conveying auger 74 as a first layer 82 . An opening 96 is present for this purpose in the bottom of the hopper 22 or the chambers 68 , 70 . As long as there is also material in the chamber 70 , it is added as a comparatively thin second layer 84 on top of the first layer 82 . Accordingly, the chamber 70 is arranged behind the chamber 68 , in the running direction 86 of the conveyor 24 , in other words in the opposite direction to the direction of travel 36 . It is hereby ensured that the material from the chamber 70 can be added to the material from the chamber 68 . Because only a relatively thin layer 84 of the colder material from the chamber 70 is used in comparison with the layer 82 , the temperature of the colder material can be matched to that of the warmer material. All in all, a homogenization of the temperature is achieved that approaches the optimum surfacing temperature.
The upper layer 84 can but does not have to be applied as a continuous layer on top of the lower layer 82 . In particular, if the chamber 70 is empty or also for a better distribution of the material, an interrupted addition, or addition in sections, of the colder material can also take place. The layer 84 is then not formed as a continuous layer as shown in FIG. 4 but has interruptions. As a distributing auger 20 is arranged in the region of the screed 18 , a corresponding mixture is nevertheless ensured. Additionally, however, another mixing system and/or an additional mixing device can be arranged at the end of the conveyor 24 , which effects an additional thorough mixing. The conveying augers 74 at the same time serve as mixing and conveying augers. Viewed from above, they are arranged parallel to each other.
In the embodiment in FIGS. 7 and 8 , the homogenizer 72 has four conveying augers 74 which are arranged transversely to the direction of travel or to the mounting direction. The conveying augers 74 in each pair are arranged parallel to each other. They serve to supply the material, in particular in counterrotating fashion, for the purpose of thorough mixing. Because chambers 68 and 70 on either side of the hopper 22 are divided by the guide plates 64 , materials at different temperatures can be poured into the two chambers 68 and 70 . By controlling the conveying augers 74 beneath the respective chambers 68 and 70 , the material contained in each case can be conveyed in a metered fashion into the region of the conveyor 24 arranged beneath the hopper 22 . When, for example, one chamber 68 contains the material at the right temperature, this material can be supplied to the conveyor 24 as a base material or lower layer 82 . A metered supply of comparatively small amounts of the colder material from the chamber 70 as a second layer 84 results in an only slight cooling of the base material and a sufficient heating up of the added material from the chamber 70 . All in all, a suitable temperature of the material for producing a roadway paving is thus ensured.
A further alternative embodiment is shown in FIGS. 9 to 11 . Here the two chambers 68 and 70 are arranged next to each other in the direction of travel above the wheels 76 . A mixing chamber 88 is situated behind. Two conveying augers 74 for metering the addition of material into the mixing chamber 88 are arranged in the region of the chambers 68 and 70 . A total of four conveying augers 74 , which serve to convey or mix the material, are arranged in the lower region of the mixing chamber 88 . A deflecting flap or a deflecting member 80 , or alternatively a conveyor belt, is arranged above the chambers 68 and 70 . The deflecting flap 80 or the conveyor belt serve to guide the material laterally into the different chambers 68 and 70 . The chamber 68 contains the warmer material at the right temperature, and the chamber 70 contains the colder material.
The embodiment in FIGS. 12 to 14 shows a hopper 22 in which a bucket 90 is arranged. This bucket 90 overall has a conical shape with a circular cross section. It is arranged with its feeding end pointing downwards. A plurality of holes 94 are arranged in the side wall 92 of the bucket 90 . The opening 96 in the bottom here also serves to discharge material onto the conveyor 24 .
The homogenizer 72 of this embodiment that is shown functions as follows: the material at the correct temperature is poured into the inside of the bucket 90 . The material that is too cold or which is separated is added into the hopper 22 beneath the bucket 90 . While material is discharged through the opening 96 in the bottom onto the conveyor 24 , the filling level inside the hopper 22 or in the chamber 68 falls so that a growing number of holes 94 are present above the material. As soon as material outside the bucket 90 has a higher filling level, this material flows laterally through the holes 94 into the bucket 90 and onto the warmer material situated therein. However, this happens only in metered proportions as the amount of the material flowing in is determined by the filling level in the bucket 90 . As soon as more warmer material is added, its filling level may exceed the filling level outside the bucket 90 so that cold material can no longer flow into the inside of the bucket 90 . Moreover, not only is the cold material in the bucket 90 covered with new material, but also material from the inside of the bucket 90 flows out through the holes 104 . All in all, this results in a thorough mixing of warm and cold material.
The process according to the invention functions as follows:
The temperature of the material supplied from the feeder 14 is determined. To do this, for example a measuring apparatus 98 is provided, such as at least one heat sensor or infrared sensor or even an infrared camera. In order to scan the entire stream of material simply, the measuring apparatus 98 is arranged above the conveyor 42 on the feeder 14 . It is also possible to provide a plurality, at least two, but preferably three measuring apparatus 98 and/or a measuring apparatus 98 having at least two, but preferably three sensors. The sensors or measuring apparatus 98 are preferably distributed in linear fashion along the conveying path of the conveyor boom 40 .
As soon as it is established that at least part of the material or the stream of material has material that is too cold, the corresponding part of the material is separated, for example with the aid of a deflecting member 80 or with the aid of a guide plate. This part of the material to be homogenized is thereby guided away into the separate chamber 70 .
The other material, which is at the correct temperature, passes into the chamber 68 . Material is removed from these two chambers 68 and 70 in order to be supplied to the road paver 12 or the screed 18 to produce an asphalt layer. In this way, the colder material from the chamber 70 is supplied to the material at the correct temperature from the chamber 68 only in the proportion that causes no excessive cooling of the material at the correct temperature and, on the other hand, that the material which is too cold is heated up sufficiently.
As so-called “nests” of cold material, which are usually only local, are present in the stream of material, for example on the conveyor 24 of the road paver 12 or also on the conveyor 42 of the feeder 14 , a suitable spatial resolution of the measuring apparatus 98 must be provided. The resolution should be provided such that, on the one hand, the nests are recognized and, on the other hand, no colder areas are ignored, creating no problems. This is, for example, ensured by three sensors or also an infrared camera system.
The measuring apparatus 98 for determining the temperature can be provided, for example, on the feeder 14 . Alternatively, the arrangement can also, however, be situated in the region of the road paver 12 . The device for homogenizing the material, in other words in particular the homogenizer 72 , can be substituted for the hopper 22 of the road paver 12 . Alternatively, a separate, in particular self-propelled homogenizer can also be used. It is also possible to substitute the hopper 22 on the feeder 14 for a corresponding device for homogenizing. The apparatus for measuring the temperature must accordingly be arranged in front of the corresponding device for separating the material.
In the following, a further exemplary embodiment of the invention will be described with reference to FIGS. 15 and 16 :
As in the previous exemplary embodiment, the hopper 120 serves to accommodate the mix which has the correct temperature. Shown in FIG. 16 is the conveyor 122 with the two slatted frames 140 . An additional mixing container 124 is arranged downstream with respect to the conveyor 122 , i.e. in the direction of the screed (not shown) to the right. This mixing container 124 has a (horizontal) cross-section which is circular in shape. Correspondingly, it assumes an essentially cylindrical configuration. In this arrangement, the mixing container 124 assumes an upright or vertical alignment. Located at its top end is a circular filling opening 126 , which has essentially the same cross-section as the mixing container 124 . Located at the lower end is a conically tapering region 128 , at the bottom of which a discharge opening 130 is provided. The discharge opening 130 is located above the conveyor 122 and thus above the material flow of the mixture as it is conveyed by the conveyor 122 out of the hopper 120 . Accordingly, the mixture discharged from the mixing container 124 is added to the other mixture on the conveyor 122 .
The mixing container 124 has a mixing device 150 with a central rotational axis 132 , about which a plurality of wings or blades 134 , 136 is arranged. In this arrangement the blades 134 , 136 extend essentially from the rotational axis 132 almost to an inner wall 138 of the mixing container 124 . In the present case, the blades 134 , 136 are configured as alternating concave blades 134 and convex blades 136 . When the mixing device 150 revolves about its rotational axis 132 , this ensures that the mixture located between the blades 134 and 136 is moved alternately along the path of the mixture from the upper filling opening 126 to the lower discharge opening 130 and from the inner wall 138 toward the rotational axis 132 and vice versa. This ensures that the mixture is moved in an essentially oscillating manner and is thus blended quite effectively.
In order for asphalt too cold for incorporation into an asphalt layer to be brought to the correct temperature, the mixing container 124 has a heating element (not shown). In this arrangement, the blades 134 and 136 can be heated by an electric or gas powered heating element. Alternatively, or as a supplement, the inner wall 138 of the mixing container 124 can also be heated. Provided in the outer wall of the mixing container 124 is a flue 148 . In case a gas heater is employed, the flue 148 serves as an channel for discharging combustion gases or as a general discharge conduit for gases escaping from the mixture.
In order to determine the temperature or temperature distribution of the mixture in the mixing container 124 , a plurality of temperature sensors 146 are disposed at least in the lower region of the mixing container 124 at different heights or even arranged one above the another in a vertical alignment. Here the temperature sensors 146 are positioned on opposing sides of the mixing container 124 at different heights. Accordingly, as soon as the temperature lies within a predetermined range or matches the temperature of the mixture in the main hopper 120 within the tolerance limits, the discharge opening 130 at the lower end of the mixing container 124 can be opened to discharge at least part of the homogenized mixture. Provided for this is a sliding or revolving closure 142 .
In order to provide an additional means for regulating the overall flow of material, a further closure 144 is arranged above the conveyor 122 for adjusting the total volume of the mixture discharged on the conveyor.
The foregoing detailed description of the preferred embodiments and the appended figures have been presented only for illustrative and descriptive purposes. They are not intended to be exhaustive and are not intended to limit the scope and spirit of the invention. The embodiments were selected and described to best explain the principles of the invention and its practical applications. One skilled in the art will recognize that many variations can be made to the invention disclosed in this specification without departing from the scope and spirit of the invention.
LIST OF DESIGNATIONS
10 paving train
12 road paver
14 feeder
16 undercarriage
18 screed
20 distributing auger
22 hopper
24 conveyor
26 drive unit
28 operating platform
30 operating elements
32 seat
34 roof
36 direction of travel
38 subsurface
40 conveying boom
42 conveyor
44 pivoting device
46 undercarriage
48 drive unit
50 operating platform
52 operating elements
54 seat
56 roof
58 hopper
60 conveyor
62 tensioning roller
64 guide plate
66 guide plate
68 chamber
70 chamber
72 homogenizer
74 conveying auger
76 wheel
78 partition wall
80 deflecting member
82 layer
84 layer
86 running direction
88 mixing chamber
90 bucket
92 side wall
94 hole
96 opening
98 measuring apparatus
100 scraper belt
102 tensioning roller
104 side wall
120 hopper
122 conveyor
124 mixing container
126 filling opening
128 conically tapering region
130 discharge opening
132 rotational axis
134 blade
136 blade
138 inner wall
140 slatted frame
142 closure
144 closure
146 temperature sensor
148 flue
150 mixing device
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A process for producing an asphalt layer in which material with properties that deviate from predetermined requirements is specifically homogenized, and a paving train ( 10 ), a road paver ( 12 ) and a feeder ( 14 ) for carrying out the process.
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RELATED APPLICATIONS
[0001] The present application is based on, and claims priority from, UK Patent Application Number 0513901.9, filed Jul. 6, 2005, the disclosure of which is hereby incorporated by reference herein in its entirety.
BACKGROUND
[0002] The present invention relates to measuring or assessing the structural integrity of, the structural change in, or damage to, an aircraft component, and in particular to a load bearing metal element used as a safe-life component on an aircraft.
[0003] A safe-life component on an aircraft must be structurally safe throughout the entire working life of the component and in particular must not be allowed to develop cracks that could prejudice such structural safety, to yield to any non-negligible degree or to fail in any other way. (It will be understood that superficial micro-cracking on the surface of a safe-life component does not in itself constitute cracking that could prejudice structural safety. As such in the context of the present invention it will be understood that a component may be considered as being “crack-free” or “free from cracks”, despite the component having superficial micro-cracking, provided that such micro-cracking is of a nature that does not in itself prejudice structural safety.)
[0004] Safe-life components can be distinguished from “fail-safe” components, which are designed to be able to sustain damage or be allowed to develop cracks, to yield, or even fail, without presenting an unacceptable short-term safety risk. Fail-safe components may for example be able to sustain damage or partial failure without significantly affecting the ability of the component to perform its function, or if so significantly affected there are other components that are able to act as a back-up. For example, the failure of a safe-life component during service would be at risk of prejudicing safety to an unacceptable degree even in the short-term, whereas failure of a fail-safe component would be able to be tolerated until the next available opportunity for maintenance. Operators of aircraft typically have to conduct scheduled inspections of safe-life components at fixed intervals. Also, a safe-life component generally has to be replaced after a certain length of service so as to manage effectively the risk of failure of such a component in service. In view of the unacceptability of failure of a safe-life component during service, safe-life components are typically withdrawn far in advance of the possible maximum length of useable service and consequently the maximum length of service for safe-life components is typically conservatively short. Whilst such short lifetimes of safe-life components is wasteful, there is currently no means of effectively reducing the risk that a particular safe-life aircraft component will fail significantly in advance of the average lifetime. The present invention has been made in recognition that there has been a lack of effective means of assessing the structural integrity of such safe-life components once in use.
[0005] Various methods exist for measuring the structural integrity of a load bearing metal element including, for example, non-destructive testing methods (such as by means of X-ray radiography) and microscope analysis. Such techniques with their limited accuracy and other disadvantages, have limited application in relation to assessing and monitoring the structural integrity of a safe-life component. The present invention concerns the use of acoustic emission monitoring to assess the structural integrity of a safe-life aircraft component.
[0006] A method for detecting and monitoring fractures in a structure by monitoring acoustic emissions is disclosed in International Patent Application No. PCT/GB01/02213 (published under No. WO 01/94934) which is incorporated herein by reference in its entirety. The method of detecting and monitoring for damage in metal structures as described in WO 01/94934 relies on monitoring acoustic emissions caused by fractures or cracks. Such a method is therefore of no use when monitoring for damage in safe-life aircraft components, because it is a requirement that such components are free from cracks.
[0007] An experiment concerning the use of acoustic emissions to check the condition of a cylindrical specimen at high temperature is described in a paper entitled “Acoustic-Emission Study of Damage Accumulation During Alternating Load-Cycle Loading at Elevated Temperature” by N. G. Bychkov et al which is translated from “Problemy Prochnosti, No. 11, pp. 21-23, November 1983” of the “Central Institute of Aircraft Engine Design, Moscow and which is incorporated herein by reference in its entirety. The teaching of that paper relates primarily to monitoring of crack growth, and predicting imminent fracture in high temperature samples, in an experimental/laboratory setting utilizing a waveguide to carry acoustic emissions from the sample, which is housed in a furnace, to an acoustic emission transducer. As mentioned above, the present invention is concerned with structural health monitoring of safe-life components on an aircraft, such components being required to be free from cracks.
SUMMARY
[0008] It is an aim of the present invention to provide an improved method of measuring the structural integrity of a load bearing aircraft component for example by providing a method of measuring the structural integrity of a safe-life aircraft component made from a metal element.
[0009] The present invention provides a method of measuring the structural integrity of a safe-life aircraft component comprising a load-bearing metal element, the method including the steps of:
[0010] converting acoustic emissions generated in the metal element into electronic signals, the acoustic emissions converted including “relevant acoustic emissions”, namely acoustic emissions resulting from changes in the structure of the element that make the element more susceptible to the formation of cracks,
[0011] sending the electronic signals to a processing unit, and,
[0012] with the processing unit, processing over time the signals in conjunction with stored reference data that allows a measure of the structural integrity to be made from the signals sent to the processing unit, and
[0013] outputting information providing a measure of the structural integrity of the aircraft component. Thus the method of the invention may be implemented to monitor for damage to, changes in, or deterioration of, the structure of the metal element before a crack occurs.
[0014] It will of course be appreciated that the electronic signals may be modified before being received by the processor. For example, the electronic signals may be converted from analogue to digital signals.
[0015] The step of processing the signals may include assessing whether one or more signals correspond to a “relevant acoustic emission” and preferably includes assessing which of each acoustic emission signal corresponds to a “relevant acoustic emission”. For example, acoustic emissions that conform to pre-set criteria characterising a relevant acoustic emission may be deemed as corresponding to a relevant acoustic emission. Acoustic emission signals assessed as not corresponding to a relevant acoustic emission are preferably discarded by the processing unit, for example being ignored for the purposes of performing the method of the invention as defined herein. The step of assessing whether an acoustic emission may be deemed as corresponding to a relevant acoustic emission may include assessing whether the acoustic emission is one that is typical of an acoustic emission resulting from changes in the structure of the element at a scale of the order of a few microns or less.
[0016] The step of processing the signals advantageously includes calculating, and preferably additionally monitoring, the cumulative number of relevant acoustic emissions over a period, for example a pre-set period. The period may for example be a period of time measured from the first time the method is performed on the metal element. The period of time may exclude times during which the metal element is not being subjected to loading of the type likely to change or affect the structural integrity of the aircraft component. The period may alternatively be measured as a number of nominal cycles of fatigue loading. The period may be measured as a number of actual cycles of fatigue loading (the cycles being detected by an appropriately arranged sensing system). Such a calculation may be performed without assessing the location of the acoustic emissions. In contrast to methods of the prior art (such as that described in WO 01/94934), the present invention is able to measure the global structural properties of an element without first having to determine the locations of the source of the acoustic emissions in the element. It will of course be appreciated that location information may additionally be used in the performance of a method according to the present invention.
[0017] The step of processing the signals may include a step of effectively comparing the cumulative number of relevant acoustic emissions with a pre-set threshold. The threshold may for example be set such that above the threshold there is a given probability of a crack having occurred in the element. Once the threshold is exceeded the method may include taking further action, for example, remedial action.
[0018] The step of processing the signals may include additionally or alternatively include a step of calculating, and preferably additionally monitoring, the number of relevant acoustic emissions over a pre-set period. Again, the pre-set period may be a pre-set period of time or alternatively a pre-set period of nominal loading cycles. The pre-set period is preferably short enough to be short relative to the expected lifetime of the element, but long enough that the number of relevant acoustic emissions detected during said period can be considered as not being significantly affected by the inherently noisy and seemingly random nature of the rate of emission of relevant acoustic emissions. The pre-set period may be a constant period of time in the past as measured from the instant at which the step of processing the signals is performed. Again, the number of relevant acoustic emissions over the period may be compared to a threshold and if the threshold is exceeded appropriate further action may be taken.
[0019] The step of processing the signals may include performing calculations using a measure of the size of a relevant acoustic emission, for example, the peak amplitude, the average signal level, the rise time of the emission, the energy and/or the duration of the emission. The measure of the size of a relevant acoustic emission may be used to weight the relevance of the relevant acoustic emission as compared to other relevant acoustic emissions of a different size.
[0020] The method may include a step of detecting acoustic emissions at different frequencies and/or calculating a characteristic relating thereto. The step of processing the signals may for example include taking account of the frequencies of the respective relevant acoustic emissions. The frequency of the signal used in such a step may for example be the fundamental frequency, or a frequency equal to an integer multiple of the fundamental frequency.
[0021] The step of processing the signals may include a step of calculating a characteristic relating to (for example being equal to) the rate of relevant acoustic emissions.
[0022] The step of processing the signals may include a step of calculating a characteristic relating to (for example being equal to) the spatial density of relevant acoustic emissions.
[0023] The step of processing the signals may include a step of calculating a characteristic relating to (for example being equal to) an indication of the timing or order of successive relevant acoustic emissions.
[0024] The step of processing the signals may include weighting any of the parameters or characteristics mentioned herein according to the size of the relevant acoustic emissions.
[0025] The step of processing signals may include calculating one or more proximity characteristics that provide an indication of the proximity of the sources of respective relevant acoustic emissions relative to each other. Such proximity characteristics may simply be in the form of location co-ordinates. Such proximity characteristics may be associated, or embedded with, any of the other parameters or characteristics mentioned herein. Thus, the step of processing the signals may include a step of taking into account an indication of the proximity of the sources of the respective relevant acoustic emissions relevant to each other.
[0026] The step of processing the signals may include a step of differentiating a first variable with respect to a second variable. For example, the differential calculated may be a measure of the rate of change of the cumulative number of relevant acoustic emissions.
[0027] The step of processing the signals may include a step of integrating a first variable over a range defined by means of a second variable. For example, the step of processing the signals may include a step of calculating a characteristic relating to (for example being equal to) the integral of the cumulative number of relevant acoustic emissions with respect to a pre-set period.
[0028] The step of processing the signals may include calculating characteristics of notional graphs (such characteristics for example including differentials or integrals), the notional graphs having at least two axes dependent on any two independent variables representative of any of the parameters or characteristics mentioned herein. It will be understood of course that the characteristics of the notional graphs may be calculated either with or without creating a physical representation (such as a drawing for example) of the graph.
[0029] The step of processing the signals may include using non-acoustic data. Such non-acoustic data may include a measure of stress and/or strain in relation to the metal element as measured by for example one or more strain gauges or other sensors associated with the metal element. The non-acoustic data may alternatively or additionally include a measure of temperature. The method may of course combine any of the above-described steps of processing the signals. For example, both characteristics relating to the cumulative number of relevant acoustic emissions, and to the number of relevant acoustic emissions over a pre-set period of time may be calculated and monitored. In such a case, the method may monitor whether the two characteristics meet given criteria, such as each characteristic exceeding a respective given threshold. In the event that such criteria are met the method may include taking further action. More generally, the step of processing the signals may include a step of calculating a plurality of characteristics selected from any of the characteristics or parameters mentioned herein. The plurality of characteristics so calculated may then be compared with pre-set criteria, the criteria being selected such that once met the aircraft component is deemed to be in need of further, for example remedial, action. The step of calculating a plurality of different characteristics may for example comprise performing two or more of steps (a) to (n), where steps (a) to (n) are as follows:
[0030] (a) assessing whether one or more signals correspond to a “relevant acoustic emission”,
[0031] (b) assessing which of each acoustic emission signal corresponds to a “relevant acoustic emission”,
[0032] (c) calculating the cumulative number of relevant acoustic emissions over a period,
[0033] (d) assessing the location of the acoustic emissions,
[0034] (e) effectively comparing the cumulative number of relevant acoustic emissions with a pre-set threshold,
[0035] (f) calculating the number of relevant acoustic emissions over a pre-set period,
[0036] (g) using a measure of the size of a relevant acoustic emission,
[0037] (h) detecting acoustic emissions at different frequencies,
[0038] (i) calculating a characteristic relating to the rate of relevant acoustic emissions,
[0039] (j) calculating a characteristic relating to the spatial density of relevant acoustic emissions,
[0040] (k) calculating a characteristic relating to the timing or order of successive relevant acoustic emissions,
[0041] (l) calculating one or more proximity characteristics that provide an indication of the proximity of the sources of respective relevant acoustic emissions relative to each other,
[0042] (m) calculating a characteristic relating to the integral of the cumulative number of relevant acoustic emissions with respect to a pre-set period, and
[0043] (n) calculating characteristics of notional graphs, the notional graphs having at least two axes dependent on any two independent variables representative of any of the parameters or characteristics mentioned in steps (a) to (m) above.
[0044] The method may of course also include implementing the further action. In such a case the step of implementing of the further action may of course replace the step of deeming of the need for the further action.
[0045] Above it is stated that further action may be taken, or may be deemed to be in need of being taken, if a threshold is exceeded or if certain criteria are met. The further action may simply be to provide an indication, electronic or otherwise, that indicates that the threshold has been exceeded or the criteria have been met, as is appropriate. Such an indication may be arranged to be arranged to be discoverable during maintenance procedures relating to the aircraft component. The further action may comprise testing the aircraft component or a part thereof, for example the metal element with other means or performing such tests, if already routinely performed, more often. The further action may include further non-destructive testing to obtain an assessment of the structural integrity of the metal element. Preferably, such non-destructive testing is not dependent on the monitoring of acoustic emissions.
[0046] The further actions may be in the form of physical activity affecting the use or function of the aircraft component. For example, the further action may comprise replacing the aircraft component, or a part thereof.
[0047] The further action may include a step of repairing the aircraft component or a part thereof.
[0048] The criteria mentioned above may be pre-selected by means of a method including performing empirical testing, for example by means of a series of experiments using test rigs. The criteria may additionally or alternatively be pre-selected by means of a method including performing computer modelling of the aircraft component.
[0049] It will be appreciated that the thresholds and criteria mentioned herein may form the totality or part of the stored reference data that is used when processing the signals to provide the information outputted by the processing unit that provides the measure of the structural integrity of the element.
[0050] The information outputted may include information in any of a wide variety of forms. The outputted information may include data providing a measure of the structural integrity of the element. The outputted information may comprise data providing an assessment of the structural change in, or damage to, the aircraft component. The information may be in the form of a prediction, for example of the likeliness of a crack forming. The information could for example be in the form of a prediction of the mean time left before a crack will occur. The outputted information may include an indication of the expected useable life-span of the metal element, for example by providing indications of the mean time that the element could feasibly remain in service. The information could include indications relating to the structural integrity of the element compared to those of a notional average element.
[0051] The outputted information may include information concerning the source or sources of the relevant acoustic emissions. For example, the output may include information concerning the location(s) in the element of the source or sources.
[0052] The information outputted is preferably in electronic form, for example in the form of electronic data.
[0053] A multiplicity of acoustic emission sensors may be provided in order to effect the step of converting acoustic emissions generated in the aircraft component into electronic signals. For example, the multiplicity of acoustic emission sensors may be attached to the metal element. Alternatively, the multiplicity of acoustic emission sensors may be in the form of remote sensors that are able to detect acoustic emissions without needing contact with the metal element. For example, the acoustic emission sensors may be in the form of remote laser source and detector arrangements, laser light being directed onto the surface of the metal element and reflected back to one or more detectors. Preferably, a sufficient number of sensors are provided to enable the location of the source of a relevant acoustic emission to be ascertained by triangulation techniques.
[0054] The method may be performed such that at least two of the acoustic emission sensors have a fundamental resonant frequency at a first frequency and at least two acoustic emission sensors have a fundamental resonant frequency at a second frequency, the first and second frequencies being different. Acoustic emissions at different frequencies may thereby be detected. Also, the different acoustic emission sensors may be able to provide a frequency-amplitude profile of an acoustic emission. The frequency-amplitude profile of an acoustic emission may for example be used to assist detection of relevant acoustic emissions.
[0055] The metal element may be in the form of a safety critical load-bearing element that in use is required to be free from cracks. The metal element need not be made exclusively from metals. For example, the metal element may be in the form of a metal alloy or mixture containing non-metallic materials, for example composite material additives. The metal element may be in the form of any homogeneous structure which is prone to the formation of cracks under fatigue loading, where before the formation of a crack occurs there are structural changes that cause acoustic emissions to be made. The aircraft component may be in the form of any safe-life component on an aircraft. For example the component may be a component on an aircraft landing gear. The component may be a landing gear leg. The aircraft component may be an engine pylori. The aircraft component may be a landing gear rib. The aircraft component may be an aircraft bulk head. The aircraft component will typically have an average temperature, during performance of the method, that is substantially the same as ambient temperature. The average temperature of the component may for example be less than 100° C.
[0056] The method described herein of measuring the structural integrity of an element may be in the form of a method of measuring the plasticity of such an element. Thus, the information outputted may be a measure of the plasticity of the load bearing metal element.
[0057] The methods of the invention described above include both acquisition and processing of data. The processing of the data may be performed in real-time soon after the data is acquired. Alternatively, the data may be stored for subsequent processing at a significantly later time, for example, during routine periodic maintenance of the metal element. Thus, the present invention further provides a method of acquiring data for subsequent processing, the data concerning the structural properties of a safe-life aircraft component comprising a load-bearing metal element, the method including the steps of converting acoustic emissions generated in the metal element into electronic signals, the acoustic emissions converted including “relevant acoustic emissions”, namely acoustic emissions resulting from changes in the structure of the element, and storing the electronic signals as measurement data in a data store. The data so acquired may then subsequently be processed. Thus there is further provided a method of measuring the structural integrity of a safe-life aircraft component comprising load-bearing metal element, the method including the steps of acquiring measurement data, and then subsequently processing the data so acquired with a processing unit in conjunction with stored reference data that allows a measure of the structural integrity to be made from the acquired measurement data, and outputting information providing a measure of the structural integrity of the aircraft component. The measurement data so acquired may include data concerning relevant acoustic emissions, for example data produced by means of performance of the data acquisition method described immediately above.
[0058] The method according to any aspect of the invention described herein is advantageously performed a multiplicity of successive times in respect of a given metal element of an aircraft component. Preferably, the method is performed such that the structural integrity of the aircraft component is effectively continuously measured and monitored.
[0059] The present invention further provides a processing unit programmed to perform the steps performed by the processing unit of the method according to any aspect of the invention described herein.
[0060] The present invention also provides computer software, for example in the form of a computer software product, that is configured to programme a processing unit to perform the steps performed by the processing unit of the method according to any aspect of the invention described herein.
[0061] The present invention further provides computer data, for example in the form of a computer data product, containing reference data for use as the stored reference data as required by the method according to any aspect of the invention described herein.
[0062] There is also provided a kit of parts including a processing unit and a multiplicity of acoustic emission sensors, the kit of parts being able to be configured to implement the method according to any aspect of the invention described herein. The kit of parts may further include computer data as described above.
[0063] The present invention yet further provides a kit of parts including a multiplicity of acoustic emission sensors and a data storage means for the storage of measurement data for subsequent processing, the kits of parts being able to be configured to implement the method according to any aspect of the invention described herein, in which data is stored for subsequent processing.
[0064] In accordance with the present invention there is also provided an apparatus for performing the method of the invention. The apparatus advantageously includes a safe-life aircraft component comprising a load-bearing metal element, a processing unit, a multiplicity of acoustic emission sensors, and a reference data store. The apparatus is advantageously so arranged that
[0065] the multiplicity of acoustic emission sensors is arranged to convert acoustic emissions generated in the metal element into electronic signals,
[0066] the processing unit is arranged to receive electronic signals derived from the signals sent by the acoustic emission sensors,
[0067] the reference data store includes stored reference data that allows a measure of the structural integrity of the aircraft component to be made from the signals sent to the processing unit,
[0068] the processing unit is arranged to process over time the received electronic signals in conjunction with the stored reference data and to output information providing a measure of the structural integrity of the aircraft component.
[0069] The present invention also provides an apparatus for performing any aspect of the method of the invention described herein of acquiring data for subsequent processing, the apparatus including a safe-life aircraft component comprising a load-bearing metal element, a multiplicity of acoustic emission sensors, and a measurement data store. The apparatus is advantageously so arranged that
[0070] the multiplicity of acoustic emission sensors is arranged to convert acoustic emissions generated in the metal element into electronic signals, and
[0071] the measurement data store is arranged to receive data signals derived from the electronic signals from the acoustic emission sensors and to store those signals as measurement data in the measurement data store.
[0072] The term structural integrity is used herein in relation to the structure of the metal element of the aircraft component on the same scale as the size of cracks which are deemed to be too large for safety reasons on a safe-life structure. The integrity of a structure may be defined by a measure of the likelihood of the structure containing a crack. The structural integrity of a structure may be defined by a measure of the likelihood of a crack being formed in the structure, for example after certain criteria have been satisfied (such as a certain time having elapsed and/or certain loading conditions having been satisfied). The structural integrity of a structure may be defined by a measure of the amount of changes in the submicrostructure that contribute to the formation of cracks. The term crack as used herein is intended to cover cracks on a microscopic scale, that is cracks that can, once the relevant cross-section is made visible, be identified with the aid of a microscope. The term “crack” as used herein is also intended to cover cracks that are able to be readily detectable via the use of standard non-destructive detection techniques, such as eddy current testing. Such techniques reliably enable detection of cracks having a length of over 0.5 mm. It will of course be understood that the present invention advantageously enables detection of cracks and crack formation where the size of the crack is such that the crack would be undetectable using current non-destructive testing techniques. Moreover the invention advantageously enables measurements of the structural integrity of an aircraft component to be made before cracks form. It will also be understood that micro-cracks, in particular micro-cracking on the surface of a metal load bearing element, is not necessarily either a crack that significantly prejudices safety or one that needs to be detected by means of the present invention. However, it should be noted that the present invention may facilitate the detection of submicrostructure changes that contribute to the eventual formation of cracks and that therefore affect the structural integrity of a safe-life aircraft component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] By way of example, an embodiment of the present invention will now be described with reference to the accompanying drawings, of which:
[0074] FIG. 1 shows in plan view a test element with acoustic sensors attached thereto,
[0075] FIG. 2 is a schematic diagram showing a test acoustic emission being caused on the test element,
[0076] FIG. 3 is a graph showing the S-N curves for the material from which the test element is made,
[0077] FIG. 4 is a graph showing the cumulative number of acoustic emissions detected in the test element over time,
[0078] FIG. 5 is a graph showing the number of acoustic emissions detected in the test element over time for 15 consecutive runs, and
[0079] FIG. 6 is a schematic diagram showing apparatus for assessing the structural integrity of a landing gear leg according to the embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0080] Experiments were carried out to test the feasibility of the embodiment of the present invention. As the embodiment of the present invention is based closely on the experiments that were carried out, one of those experiments will now be described in further detail.
[0081] The aim of the experiment was to evaluate the effectiveness of an acoustic emission measurement system in detecting early damage in a test element. Specimen test elements 100 were tested in fatigue, a schematic diagram of which is shown in FIG. 1 . The specimens 100 were made of hardened 300M steel, and included a hole 102 in their middle. The specimens were 350 mm (in the x-direction) by 70 mm (in the y-direction) by 6 mm with a hole 4.4 mm in diameter. The width (in the y-direction) in the waisted middle of the specimens was 26 mm. The specimens were instrumented with five sensors S 1 -S 5 . The sensor coordinates are given in Table 1 below:
[0000]
TABLE 1
Sensor coordinates
S1
S2
S3
S4
S5
x = 80,
x = 130,
x = 230,
x = 245,
x = 270,
y = 35
y = 35
y = 30
y = 45
y = 35
[0082] The role of sensors S 1 and S 5 was to enable the filtering out of waves originating from the clamping device used to hold the specimen 100 . Sensors S 2 , S 3 and S 4 monitor the acoustic emissions coming from the hole and its vicinity. The hole was introduced to ensure the location of damage as well as to reduce the scatter factor of the failure of the specimens.
[0083] The resonant frequency of the sensors and their pre-amplifiers was 600 KHz. The sensors were surface bonded to the specimens with a non corrosive silicon rubber. Each pre-amplifier provided an amplification of 40 dB and a narrow band filtering of the sensor output. The acoustic emission measurement system was connected to the pre-amplifiers via coaxial cables. The load applied was read by the acoustic emission measurement system using one of its non acoustic data inputs via a coaxial cable.
[0084] Before fatiguing of the specimen was commenced the sensors S 1 to S 5 were calibrated. This operation consisted of verifying that each sensor was in good functioning order and that the sensor was properly bonded to the specimen. The calibration procedure also included a step of making acoustic emission measurements and evaluating the group velocity throughout the specimen. These group velocity measurements were used later to ascertain the location of the acoustic emission sources. Pencil lead was broken (Hsu-Nielson source) on the specimen surface, the acoustic emission measurement system measuring the time difference of flight, ΔT i , namely the travel time difference from the first hit sensor to the i th hit sensor. With reference to FIG. 2 , if the separation between the acoustic emission AE and the first sensor S 1 is distance a 1 and the separation between the acoustic emission AE and the second sensor S 2 is distance a 2 , then the velocity is calculated as b/ΔT, where b=a 2 −a 1 , and ΔT is the time between the acoustic emission being detected at sensor S 1 and the acoustic emission being detected at sensor S 2 .
[0085] The measured velocity was approximately 5 km/s, which is in agreement with the theoretical value given by the dispersion curves. The specimen 1 was then subjected to loading in the form of a sinusoidal cycle of constant amplitude 13 Hz frequency. FIG. 3 shows the S-N curves for the 300M material used to determine the maximum stress level to apply on the specimen to reach a specific load cycle for a given stress ratio. The loading was applied in a series of 15 loading runs, the loading profile applied to a particular specimen being as shown in Table 2, set out below:
[0000]
TABLE 2
Details of profile of loading applied to a specimen
Cumulative
Loading
Peak
Min.
No. of
cycles at
Run
Load
Load
cycles
end of run
1
31.5KN
3.1KN
335,960
335,960
2
31.5KN
3.1KN
166,670
502,630
3
31.5KN
3.1KN
272,265
774,895
4
31.5KN
3.1KN
432,005
1,206,900
5
37.4KN
3.1KN
191,050
1,397,950
6
37.4KN
3.7KN
146,650
1,544,600
7
37.4KN
3.4KN
150,010
1,694,610
8
42KN
4.3KN
220,000
1,914,610
9
42KN
4.3KN
230,000
2,144,610
10
42KN
4.3KN
209,990
2,354,600
11
42KN
4.3KN
90,010
2,444,610
12
42KN
4.3KN
220,160
2,664,770
13
42KN
4.3KN
190,090
2,854,860
14a
52.5KN
5.2KN
59,740
2,914,600
14b
21.2KN
2.1KN
80,950
2,995,550
15a
26KN
2.6KN
39,050
3,034,600
15b
31.5KN
3.1KN
38,410
3,073,010
[0086] The acoustic emission measurement system was able to measure the load applied in the fatigue test by means of non-acoustic measurements. During the experiment, the specimen was inspected for cracks after each run using both a microscope and NDT (Eddy Current) techniques. Acoustic emissions detected by the acoustic emission measurement system over threshold amplitude were measured and counted.
[0087] FIG. 4 illustrates a graph showing the cumulate burst count on the y-axis against time (that is time during loading, the time between runs being ignored) on the x-axis. The x-axis of the graph of FIG. 4 is divided into 15 segments, each segment representing a load run, so that the single curve on the graph represents the cumulative burst count and time passing as measured from the start of the first load run (run 1 ). FIG. 5 also shows the cumulative burst count against time for the same data as that represented by FIG. 4 , but in FIG. 5 , there are 15 separate cumulative burst curves, one for each loading run, the curves showing the cumulative burst count and time passed as measured from the start of the load run for that curve.
[0088] As can be seen, the specimen was loaded at various load levels, from 31.5 KN to 52.5 KN. A crack of length of 1.5 mm was observed as having been initiated during load run 14 , that is after about 2.9 million cycles.
[0089] During the earlier runs, the gradient of the curves of FIGS. 4 and 5 is about 0.1-0.2 burst/s. The specimen generated a gradient about 0.1 burst/s between 0.3 million cycles and 1.43 million cycles corresponding to zones 2 to 5 . The gradient increased to 0.2 burst/s between 1.43 million cycles and 2.13 million cycles corresponding to zones 8 to 10 . The gradient further increased to 0.3 burst/s between 2.4 million cycles and 2.8 million cycles corresponding to zones 11 to 13 . A significant shift in gradient (0.6 burst/s) was noticed between 2.86 million cycles and 2.93 million cycles corresponding to the load run (zone 14 ) where the crack was detected by a microscope and also by using NDT (eddy current) techniques. It will also be noted that the gradient dropped to almost zero immediately before the failure (zone 15 ) of the specimen.
[0090] As a result of the experiments that have been conducted, a method of monitoring the structural integrity of landing gear for an aircraft has been proposed. The method and the apparatus for implementing this proposal will now be described with reference to FIG. 6 , which shows a block diagram illustrating the function of the proposed embodiment.
[0091] FIG. 6 shows a landing gear leg 110 , in which there are embedded various acoustic emission sensors, of which only four are shown, S 1 -S 4 . Outputs from these sensors are fed via analogue to digital converters (not shown) to an acoustic emission measuring system 112 . The signals from the sensors S 1 -S 4 are received at a comparator/filter system 114 , which assesses whether the magnitude and frequency of the acoustic emissions received from the sensors are within preset criteria so as to be deemed as acoustic emissions (hereinafter “significant acoustic emissions”) resulting from changes within the microscopic structure of the landing gear 110 , as opposed to acoustic emissions resulting from other sources. The parameters defining any significant acoustic emission are then extracted for use in analyzing the structural integrity of the metal load bearing structure of the landing gear leg. The sensors and electronic equipment used to detect and analyse acoustic emissions are well known in relation to monitoring of cracks in metals and such apparatus may be used to implement the present embodiment. One such apparatus is described in WO 01/94934, the contents of which (in particular the contents concerning the apparatus and methods used to detect and analyse acoustic emissions as described in that document with reference to the drawings of that document) are incorporated herein by reference thereto.
[0092] The apparatus of the invention is used to make an assessment of the structural integrity of the landing gear leg, over time, by means of various methods of analysis of the measure of cumulative bursts over time. In use, a processor 116 of the measurement system 112 receives data from the comparator/filter 114 concerning extracted parameters defining the acoustic emissions judged by the comparator/filter 114 as being significant acoustic emissions. This data is then analysed in consideration of data stored in a memory store 120 that allows the processor 116 to effectively compare the real-time data with data stored in the memory 120 so that statistically valid conclusions can be drawn concerning the structural integrity of the landing gear 110 . The processed data and results are stored in a further memory store 118 for downloading during routine maintenance of the aircraft.
[0093] The method can be considered as plotting graphs similar to that shown in FIGS. 4 and 5 and analyzing various characteristics of such graphs. As has been established by experiment, there appear to be many ways in which the conditions that facilitate crack formation can be correlated to data extracted from measuring significant acoustic emissions. Indications of the structural integrity are provided by means of comparing the acoustic emissions data retrieved in use concerning the landing gear with a variety of thresholds and criteria that have been pre-set by means of prior experimentation and/or mathematical modelling. The criteria against which the structural integrity of the landing gear is compared, in this embodiment, consist of monitoring the following:
the absolute cumulative burst, the number of bursts over a range of different time periods, the burst rate, the integral of cumulative bursts over time, the above parameters when weighted by burst peak amplitude (so that more energetic acoustic emissions are given more weight than less energetic emissions), and the above parameters when considered over time when grouped by the activity of the aircraft.
[0100] In each case, the data analysed is compared against the stored reference data and a result is issued with an associated statistical probability. For example, the result might be in the form that the data recorded indicates that 1% of landing gears having the same data would be beyond 75% of the working life of the gear, and that 0.1% of landing gear having the same data would be beyond 80% of the working life of the landing gear. The result might also be in a form that states that 1% of landing gear having the same data would be beyond 23% of the expected time till first crack is detected, and that 0.1% of landing gear having the same data would be beyond 28% of the expected time till first crack is detected. During maintenance of the aircraft such results may be used to decide when a particular landing gear leg should be replaced, with the benefit of increased confidence in the structural integrity of a landing gear and possibly the benefit of enabling landing gear to be in service for longer than is now safely possible.
[0101] The criteria for assessing the structural integrity of the landing gear leg 110 will now be briefly discussed in turn with reference to the graphs shown in FIGS. 4 and 5 . Whilst various thresholds and numbers are discussed with reference to FIGS. 4 and 5 , it will of course be appreciated that FIGS. 4 and 5 correspond to data relating to a specimen test element.
Absolute Cumulative Burst
[0102] The cumulative burst count until a crack appears is similar for identical specimens. Thus, a threshold cumulative burst count can be set, over which threshold the landing gear leg should be replaced.
Number of Bursts Over a Range of Different Time Periods and Burst Rate
[0103] As can be seen from FIGS. 4 and 5 , the gradient of the curve generally increases as the curve gets closer to the instant at which a crack first appears. Thus, a threshold burst rate can be set, over which threshold the landing gear leg should be replaced. It will however be appreciated that the rate can increase to a level comparable to that reached immediately before a crack appears even though the material is not very close to a state in which cracks might appear. For example, consider the gradient of the curves corresponding to test runs 7 and 14 . As can be seen more clearly in FIG. 5 , the gradient of the latter part of the curve corresponding to test run 7 is almost as steep as the gradient of the curve corresponding to test run 14 , even though a crack first appeared during test run 14 , and test run 7 might be seen as corresponding to 50% of the maximum possible useable lifetime of the specimen. Thus, advantageously, other criteria are used to reduce the chance of a landing gear leg being withdrawn from service prematurely. Such criteria can include assessing the absolute cumulative burst count in conjunction with the gradient. For example, gradients of the curve at a given level but corresponding to a cumulative burst count being below a threshold cumulative burst count may effectively be ignored, whereas gradients of the curve at the same given level but corresponding to a cumulative burst count above the cumulative burst count threshold may be considered as warranting replacement of the landing gear leg.
[0104] The average gradient over a pre-selected interval can also be monitored. It will be seen that curve 14 has a steep gradient that is sustained over a number of bursts over 7000, whereas the steep section of curve 7 last for only about 4000 bursts. Thus, there may be set a threshold average gradient (for example in this case being 0.625 bursts/second) which must be exceeded when measured over a certain number of bursts, for example in this case, 5000 bursts. Line 124 is a line that spans 5000 bursts and which has a gradient of 0.625 bursts/second, whereas line 126 is a line that spans 5000 bursts has a gradient steeper than 0.625 bursts/second. Alternatively, the average gradient may be required to be maintained for a given length of time. For example, an average gradient of greater than 0.93 bursts/second may need to be maintained for at least 2250 seconds. Line 120 is a line that spans 2250 seconds and has a gradient of 0.93 bursts/second, whereas line 122 is a line that spans 2250 seconds and has a gradient steeper than 0.93 bursts/second.
[0105] It will of course be appreciated that a number of such criteria can be combined such that the effective test is whether over any given time interval the curve of the number of bursts against time crosses a pre-set boundary. Such a notional boundary is illustrated by the shaded area 128 in FIG. 5 . Thus, periodically (at time T, say) the boundary criteria are applied to the curve as would be drawn for the period T−T test until T, where T test is a constant time period of, say, 2000 seconds (the origin of the graph being at the point where x=T−T test and y=0). If any part of the curve crosses the boundary into the shaded area 128 the processor will decide that the landing gear leg needs replacing.
Integral of Cumulative Bursts Over Time
[0106] Again, the area under the curve of cumulative burst count over time can be monitored and can provide indications of the integrity of the structure of the landing gear leg. The integral over lifetime can be monitored as can the integral over shorter periods of time.
Weighting of Measurements
[0107] All of the above methods of monitoring the structural integrity of the landing gear leg rely on counting significant acoustic emissions, irrespective of their location, amplitude, duration or other parameters/characteristics of the acoustic emission. More sophisticated calculations can be made to weight the burst count total in view of one or more parameters or characteristics of the acoustic emission detected. For example, each burst measured could be weighted by the burst peak amplitude. Thus higher energy acoustic emissions (corresponding to comparatively greater change to the internal structure of the landing gear leg) are generally given greater weight than lower energy acoustic emissions. Such weighting could effectively replace, in part at least, the filtering and selecting step performed by the comparator/filter 14 , in that acoustic emissions that would previously be discounted as not qualifying as a significant acoustic emission are now accounted but are weighted to have less effect on the analysis carried out.
Separation of Activity of the Aircraft
[0108] Because the loading of the landing gear differs significantly according to the activity of the aircraft, the measurements made can either be weighted according to activity or measurements could be made and analysed in groups according to the activity of the aircraft. For example, the landing gear is subjected to loads during taxiing, landing and takeoff. At other times the loading on the landing gear is not significant enough to warrant continued monitoring of acoustic emissions. Giving that loading during landing is greater than during taxiing, the acoustic emissions detected during landing can be given greater weight than during taxiing. Alternatively, separate logs can be made, and/or different rates of data acquisition may be used, for measurements made during taxiing, landing and takeoff, respectively.
Combination of Methods
[0109] A variety of different methods for analyzing the acoustic emissions detected are described above and it will be appreciated that a combination of a plurality of such methods may be implemented. The choice of the methods implemented will depend on various factors including the reliability and in particular the statistical validity of the methods actually employed. Such choices can be determined and verified by means of routine experimentation and testing.
[0110] In the embodiment described above, the data processed by the comparator/filter 114 is passed to a processor 116 for real-time processing, the results of which being stored in a memory 118 . One advantage of such a system is that if, for whatever reason, the processor determines that the structural integrity of the landing gear leg rapidly deteriorates a warning can be made immediately. However, it is also acceptable for the data from the comparator/filter 114 to be processed separately. For example, the measurement system 112 could be provided without the processor 116 and the memory store 120 of previously recorded data for comparison with the measured data. In such a case, the data from the comparator/filter 114 would be simply stored in memory 118 for downloading during maintenance of the aircraft, such that the processing and analysis of the data is performed separately from the aircraft. Such a proposal would reduce complexity of the aircraft processing systems and would also have the capacity to reduce weight slightly.
[0111] Whilst the present invention has been described and illustrated with reference to a particular embodiment, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. For that reason, reference should be made to the claims for determining the true scope of the present invention. By way of example, certain further variations to the above-described embodiment will now be described.
[0112] The peak amplitudes of the acoustic emissions at the source of each acoustic emission may be monitored. The peak amplitude at the source may be calculated by means of ascertaining the location of the source of each acoustic emission. The location of the source may be ascertained by means of triangulation. The general trend of the peak amplitudes of acoustic emissions may be monitored over time. For example, it is thought that the peak amplitudes of acoustic emissions may in certain applications first follow a general upward trend and thereafter decrease following a general downward trend, after which crack initiation occurs. Thus, in an alternative embodiment of the invention, a prediction of imminent crack formation is made when the trend in peak amplitudes of acoustic emissions (the calculated peak amplitude of the acoustic emissions at their respective sources) exceeds a first preset threshold and then subsequently decreases below a second preset threshold. Such a method may in itself be sufficient to make a reasonably accurate prediction of crack initiation.
[0113] As an alternative, prediction of crack initiation may be based primarily on monitoring the rate of relevant acoustic emissions. For example, the method may include monitoring the general trend of the change in the rate of relevant acoustic emissions. Thus, in this alternative embodiment of the invention, a prediction of imminent crack initiation is made when the trend in rate of acoustic emissions exceeds a first preset threshold and then subsequently decreases below a second preset threshold.
[0114] A further variation comprises monitoring both the rate of acoustic emissions and the cumulative number of acoustic emissions. Once both monitored parameters exceed preset thresholds (or meet other preset criteria) the aircraft component being monitored may be deemed to be in need of urgent replacement.
[0115] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims.
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The structural integrity of a safe-life aircraft component on an aircraft is measured and assessed by a processing unit. The component includes a load-bearing metal element that is free from cracks. In the method, acoustic emissions generated in the metal element are converted into electronic signals. The acoustic emissions converted include relevant acoustic emissions resulting from changes in the structure of the element that make the element more susceptible to the formation of cracks. The electronic signals are set to a processing unit. The processing unit processes over time the signals in conjunction with stored reference data that allows a measure of the structural integrity to be made. Information providing a measure of the structural integrity of the aircraft component is outputted. Thus, deterioration of the structure of the component can be detected and monitored before a crack occurs.
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BACKGROUND OF THE INVENTION
This invention relates in general to a toilet closet bowl, and more particularly to apparatus for elevating the bowl above an existing floor flange. In general, existing toilet closet bowls are of a fixed height and are supplied in a low version and a higher version, the higher version being utilized by handicapped persons who, because of an infirmity, may not be able to seat themselves on a regular sized closet bowl. In the past it has been necessary to purchase a second bowl with a higher casting and discard the installed bowl. The only attempts that have been made to adapt this situation have been in public convenience rooms where the two differently sized bowls have been installed. In a private residence, however, it is impossible to install a plurality of bowls, and it is not practical from an expense standpoint to install an adjustable toilet, such as suggested by the disclosure in U.S. Pat. No. 4,091,473.
SUMMARY OF THE INVENTION
The present invention relates to a toilet closet bowl device that will elevate the bowl above an existing floor level in a simple straight forward manner, so that an existing toilet bowl may be raised to enable a handicapped person to use the same with minimal cost.
The device for elevating a toilet closet bowl in accordance with the present invention includes an extender pipe with upper and lower flanges that is adapted to be coupled directly to an existing floor flange, together with a support means that embraces the extender pipe, the support means being of a size to allow the bearing rim of a closet bowl to rest thereon. The extender pipe will have usual gasket means between the existing floor flange, as well as between the extender pipe and the closet bowl, and the extender pipe may be bolted to the floor flange by using existing flange bolts and the closet bowl may then be coupled to the upper flange of the extender pipe by another set of bolts or studs.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings
FIG. 1 is a lateral sectional view with an installed closet bowl and elevating device in accordance with the invention; and
FIG. 2 is an exploded view of the elevating device and the parts associated therewith.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In reference to the drawings, the toilet closet bowl is generally designated 10 and includes a base flange 11 and a spigot portion 12 through which waste may be discharged into a soil pipe such as 14. It is common in the United States today to have a floor flange coupled to the soil pipe. In this instance there is shown a usual floor flange 15 which has a cylindrical part 16 with an inwardly tapered wall as at 17 to receive the spigot 12 of the closet bowl. In addition, the floor flange is arranged in such a way, particularly if it is made of plastics, such that a counter bore is provided to receive the soil pipe 14. The flange is also provided with arcuate, diametral opposed slots 18 and 19, each with an enlarged portion so as to receive studs such as 20 that are provided with T-heads 21 that will pass through the enlarged portion of the slot and be slid over to a proper position for further use. As will be understood, in installing a toilet closet bowl, the studs such as 20 will extend upwardly from the slots such as 18 and 19 through apertures in the flange 11 of the toilet closet, and the closet is rotated until it is in proper position, and then nuts are tightened to hold the closet in position and to squeeze the horn spigot 12 against suitable gasketing means.
The elevating device comtemplates removing an installed closet bowl, which would be installed as for example, as seen in U.S. Pat. No. 2,082,348, and to provide further elevation to utilize an extender pipe generally designated 30, which extender pipe comprises a radially extending lower flange 32 that has a downwardly extending lip 34. The flange is made integral preferably with the cylindrical pipe section 36 which terminates in an upper flange 38. By referring to FIG. 1, the inner portion of the upper flange where it joins to the pipe is recessed as at 40 to receive the spigot or horn 12 of the closet bowl. To provide adequate sealing at the lower portion of the extender pipe, there is formed as an extension thereto below the lower surface of the radially extending flange, a spigot 41 which has its outer surface tapered. To complete the installation, circular gaskets such as 42 may lie between the bottom face of the radially extending lower flange and the existing floor flange, and will be provided with an inner portion that will nest within the recessed and tapered section 17 of the floor flange and about the outer tapered portion of the spigot 41. In assembly the inner portion of gasket 44 becomes tapered as at 45 as it snugly fits between the upper flange 38 and the outer portion of the spigot or horn 12.
In installing the extender, the extender pipe and the gaskets are assembled by having the studs 20 extend up through the extender pipe and nuts such as 48 be provided to tighten the extender pipe into position by utilizing the existing studs. In this instance a coupling nut 50 can be placed on the existing studs, and the studs may then have an extender portion 52 screwed therein that will pass on up through the upper flange apertures as at 53 and through the gasket apertures. The toilet bowl will now be placed in position after a base 60 with its aperture 61 is placed about the extender pipe.
After the parts have thus been assembled with the support means 60 that has depending peripheral flanges such as 62 thereabout, the assembly can be tightened down so that the gaskets will be tightly engaged by tightening down the nuts 56 that lie on washers 57 and engage the top surface of the closet bowl base. It will be apparent that long studs with T-heads may be also utilized in lieu of using the coupling nuts 50 and an extender studs 52; and in this case, the initial studs that pass through the existing floor flange will be of a sufficient length to allow passage into the apertures on the base of the closet bowl and have nuts tighten the assembly down, which in effect will squeeze the gaskets 44 and 42 in position and provide a good tight seal. Typically, the gaskets are made of a sponge rubber material which is resilient and will normally maintain its resilience for a long period of time so that it maintains a tight joint despite any attempt or subsequent shifting of the bowl with respect to the soil pipe as might occur due to settling of floor structures and the like.
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An elevating device for a toilet closet bowl is disclosed in which an extender pipe having upper and lower flanges is provided, along with a support platform that embraces the extender pipe and onto which the lower rim of the toilet bowl may rest.
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The invention described herein was made in the course of work under a grant or award from the Department of Health, Education, and Welfare.
DESCRIPTION
1. Technical Field
This invention relates to a compound which is characterized by vitamin D-like activity.
More specifically this invention relates to a derivative of vitamin D 3 .
Vitamin D 3 is a well-known agent for the control of calcium and phosphorous homeostasis. In the normal animal or human this compound is known to stimulate intestinal calcium transport and bone-calcium mobilization and is effective in preventing rickets.
It is also now well known that to be effective vitamin D 3 must be converted in vivo to its hydroxylated forms. For example, the vitamin is first hydroxylated in the liver to form 25-hydroxy vitamin D 3 and is further hydroxylated in the kidney to produce 1α,25-diphydroxy vitamin D 3 or 24,25-dihydroxy vitamin D 3 . The 1α-hydroxylated form of the vitamin is generally considered to be the physiologically active or hormonal form of the vitamin and to be responsible for what are termed the vitamin D-like activities, such as increasing intestinal absorption of calcium and phosphate, mobilizing bone mineral, and retaining calcium in the kidneys.
2. Background Art
References to various of vitamin D derivatives are extant in the patent and other literature. See, for example, U.S. Pat. Nos. 3,565,924 directed to 25-hydroxycholecalciferol; 3,697,559 directed to 1,25-dihydroxycholecalciferol; 3,741,996 directed to 1α-hydroxycholecalciferol; 3,907,843 directed to 1α-hydroxyergocalciferol; 3,715,374 directed to 24,25-dihydroxycholecalciferol; 3,739,001 directed to 25,26-dihydroxycholecalciferol; 3,786,062 directed to 22-dehydro-25-hydroxycholecalciferol; 3,847,955 directed to 1,24,25-trihydroxycholecalciferol; 3,906,014 directed to 3-deoxy-1α-hydroxycholecalciferol; 4,069,321 directed to the preparation of various side chain fluorinated vitamin D 3 derivatives and side chain fluorinated dihydrotachysterol 3 analogs.
Disclosure of Invention
A new derivative of vitamin D 3 has now been found which expresses excellent vitamin D-like activity and which, therefore, could serve as a substitute for vitamin D 3 in its various known applications and would be useful in the treatment of various diseases such as osteomalacia, osteodystrophy and hypoparathyroidism. This derivative is 3β,25-dihydroxy-7,8-epoxy-19-nor-9,10-secocholest-5-en-10-one, represented by structure I below. ##STR2##
Best Mode for Carrying Out the Invention
The new vitamin D derivative (compound I) was produced from 25-hydroxycholecalciferol (25-hydroxyvitamin D 3 ). In vitro incubation of 25-hydroxycholecalciferol with a kidney homogenate yielded a mixture of products from which the desired vitamin derivative, the compound of structure I above, was isolated and purified by chromatography. The compound was structurally characterized by its spectrochemical properties.
The preparation , isolation and characterization of this novel vitamin D derivative is more fully described by the examples below.
EXAMPLE 1
Preparation of Kidney Homogenate and Incubation Media
Five male albino rats, 150-175 g each, were decapitated and the kidneys were removed. A 5% (w/v) kidney homogenate was prepared in cold 0.25 M sucrose; using a Teflon/glass tissue homogenizer. The homogentate was centrifuged at 8000×g for 15 minutes; the supernatant was decanted and saved.
A buffer solution was prepared that consisted of potassium phosphate buffer, pH 7.4, 200 mM; glucose-6-phosphate, 22.4 mM; ATP, 20 mM; nicotinamide, 160 mM; and NADP, 0.40 mM. The pH was readjusted to 7.4 with 2 N KOH.
A salt solution was prepared consisting of 5 mM MgCl 2 , 100 mM KCl, and 10 units of glucose-6-phosphate dehydrogenase in 20 ml of distilled water.
EXAMPLE 2
Incubation of 25-hydroxycholecalciferol with Kidney Homogenate
Five ml of homogenate supernatant, 2.5 ml of buffer, and 2.5 ml of salt solution (all prepared as described above) were combined in a 125 ml Erlenmeyer flask. This mixture was flushed with O 2 for 30 seconds. Three hundred micrograms of 25-hydroxyvitamin D 3 in 100 μl of ethanol was then added and the flask was capped. Thirty such flasks were prepared and were incubated for two hours with shaking (120 oscillations per minuted) at 37° C. The contents of the flasks were then poured into 1500 ml of dichloromethane in a 2 liter separatory funnel; the flasks were rinsed once with dichloromethane. The resulting biphasic mixture was agitated for five minutes, followed by removal of the organic phase. The remaining aqueous phase was reextracted with 1500 ml dichloromethane. The combined organic phases were then concentrated in vacuo to ca. 100 ml, and this solution was refrigerated overnight. The resulting precipitate was removed by filtration and the solvent was removed in vacuo.
EXAMPLE 3
Isolation and Purification of Product
Evaporation of the dichloromethane extract (as obtained in Example 2) left a yellow oil, which was dissolved in 0.5 ml of chloroform/hexane (65/35, v/v) and chromatographed on a 0.7×14 cm Sephadex LH-20 column packed in the same solvent. The first 11 ml of eluant was discarded and the next 25 ml was collected. The solvent was removed in vacuo and the resulting oil was dissolved in 0.5 ml hexane/chloroform/methanol (9/1/1). This was chromatographed on a 0.7×15 cm Sephadex LH-20 column, packed in and developed with hexane/chloroform/methanol, 9/1/1 (Sephadex LH-20 is a hydroxypropyl ether derivative of a polydextran marketed by Pharmacia Fine Chemicals Inc., Piscataway, N.J.). The first 9 ml of eluant was discarded and the next 20 ml was collected; the solvents were removed in vacuo to give a clear oil.
The clear oil was dissolved in 150 μl of 9% 2-propanol/hexane and chromatographed on a 4.6×250 mm Zorbax-SiL (a product of Dupont Co., Wilmington, Delaware) straight phase high pressure liquid chromatograph column fitted on a Model ALC/GPC-204 liquid chromatograph (Waters Associates, Milford, Mass.); eluant was monitored for absorbance at 254 nm. The solvent system, 9% 2-propanol/hexane at a flow rate of 1.5 ml/min, eluted the desired product (compound I above) between 48-51 ml. After evaportion of the solvent, the sample was redissolved in 150, μl methanol/water, 70/30. This was chromatographed on a 9.4×250 mm Zorbax-ODS (octadecylsilane bonded to silia beads available through the Dupont Co., Wilmington, Delaware) reversed phase high pressure liquid chromatograph column using methanol/water, 70/30 as the eluant at a flow rate of 2.0 ml/min. The desired product (compound I) eluted between 151-153 ml; these fractions were collected and solvent evaporated under a stream of nitrogen. The compound was redissolved in 100 μl of 9% 2-propanol/hexane and was rechromatographed as above. This gave pure product.
Characterization of Product
The UV absorption spectrum of the product in absolute methanol exhibited a λ max =256 nm and a λ min =212 nm. This indicated that the vitamin D triene chromphore had been modified. When the UV spectrum was taken in ether, the λ max was shifted to 263 nm. Such a bathochromic shift is characteristic of an α,β unsaturated ketone.
The high resolution mass spectrum of the compound exhibited a molecular ion at m/e 418.3128, corresponding to the molecular formula C 26 H 42 O 4 . Since the molecular formula of the precursor, 25-hydroxyvitamin D 3 , is C 27 H 44 O 2 , the mass spectral results indicated the loss of a methylene group and addition of two oxygens. The prominent peaks at m/e 138.0674 (C 8 H 10 O 2 , representing the A ring plus C-6 and C-7), and m/e 120.0598 (138-H 2 O) indicate the addition of one oxygen atom and the loss of one methylene unit in ring A of the molecule. U.V. and mass spectral data therefore suggest the replacement of the 10,-19 methylene unit by a 10-keto function. The presence of C-25 and C-3-hydroxy groups is indicated by peaks of m/e 59 (base peak C 3 H 7 O, due to C-25,26,27+oxygen) and m/e 120 (loss of C-3-OH from ring A fragment).
The high resolution nuclear magnetic resonance spectrum of the product (270 MHz in CDCl 3 ) exhibited a one-proton doublet at δ6.43 ppm, J=10 Hz, assigned to an olefinic proton; no other olefinic resonances were observed. In particular, the two singlets at δ5.94 and δ5.3 due to the two C-19 protons, and the doublet at δ5.94 representing the C-7 proton in the precursor, 25-hydroxycholecalciferol were absent confirming the replacement of the C-19 methylene group by a ketone function. A one-proton doublet at 3.76 ppm (J=10 Hz) can be assigned to the proton of an oxirane ring system. Decoupling experiments established spin-spin coupling between the protons at 6.43 and 3.76 ppm and thus the presence of a double bond adjacent to the expoxide function. The downfield shift of the δ6.43 peak indicates that it is the C.sub.β proton of an α,β unsaturated ketone, i.e., the C-6 proton. Thus the δ3.76 resonance must be due to a single proton on C-7. Because no other changes were seen upon decoupling the C-7 proton, C-8 must be fully substituted. The presence of a 25-hydroxy function is confirmed by the six-proton singlet at δ1.28 and the C-3α-carbinyl proton multiplet at δ3.95 establishes the C-3-hydroxy function. These data therefore require a 10-keto-5,6-en-7,8-epoxide system, and the combination of spectral results cited establish formula I above as the structure of this novel vitamin D derivative.
As a final confirmation of this structure, the compound was reduced with sodium borohydride to yield the corresponding 10-hydroxy compound; the product was purified by thin layer chromatography. The UV spectrum absorption was characterized by the replacement of a λ max at 252 with a weak absorption at 230 nm, indicative of the weak chromophore of an α,β unsaturated epoxide. The 10-hydroxy compound would be characterized by biological activity equivalent to the 10-keto compound.
Biological Activity
Male rats (Holtzman Co., Madison, WI) were housed in wire cages and given food and water ad libitum for 4 weeks. They were fed a low-calcium vitamin D-deficient diet described by Suda et al (J. Nutr. 100, 1049-1050, 1970). The rats were then divided into three groups of 7-9 animals each and dosed intrajugularly with the test substances. One group received 0.1 ml of ethanol (negative control group), the second received 1,25-dihydroxycholecalciferol (1,25-(OH) 2 D 3 ) in 0.1 ml ethanol (positive control group) and the third received the new vitamin D derivative (compound I) in 0.1 ml of ethanol. Amounts are indicated in the table below. Twenty-four hours after dosing, the rats were killed, their blood was collected and their small intestine was removed.
Bone calcium mobilization activity was assayed by measuring the rise in serum calcium levels in response to test compound administered. The collected blood was centrifuged, and a 0.1 ml aliquot of the serum obtained was diluted with 1.9 ml of a 0.1% lanthanum chloride solution. Serum calcium concentrations were determined with an atomic absorption spectrometer Model 403 (Perkin-Elmer Corporation, Norwalk, Conn.). Results are tabulated below.
Intestinal calcium transport activity was determined by a modification of the technique of Martin and DeLuca (Arch. Biochem. Biophys. 134, 139-148, 1969). Results are tabulated below.
______________________________________ Ca transport activity Serum Ca μmoles .sup.45 Ca transported/ mg/100 mlCompound cm.sup.2 intestine (number ofAdministered (number of animals) animals)______________________________________0.1 ml ethanol 82.3 ± 15.6 (9) 3.9 ± 0.5 (9)1,25-(OH).sub.2 D.sub.3 (125 ng) 145.2 ± 47.8 (8) 5.2 ± 0.5 (7) p < 0.005 p < 0.001compound I (500 ng) 110.0 ± 20.7 (7) 4.9 ± 0.5 (8) p < 0.01 p < 0.005______________________________________
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Compounds having the structure ##STR1## where X is keto or hydroxy. The compounds display vitamin D like activity and would find appliction in disease states characterized by adverse calcium-phosphorous balance or behavior.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 13/494,346, filed Jun. 12, 2012 (issuing as U.S. Pat. No. 8,356,661 on Jan. 22, 2013), which was a continuation of U.S. patent application Ser. No. 12/638,252, filed Dec. 15, 2009 (issued as U.S. Pat. No. 8,196,650 on Jun. 12, 2012), which was a non-provisional application of U.S. Provisional Patent Application Ser. No. 61/122,434, filed Dec. 15, 2008. Each of these applications are incorporated herein by reference and to which priority is claimed.
U.S. Pat. No. 7,281,589, issued Oct. 16, 2007 is incorporated herein by reference.
U.S. Pat. No. 7,681,646, issued Mar. 23, 2010 is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND
In top drive rigs, the use of a top drive unit, or top drive power unit is employed to rotate drill pipe, or well string in a well bore. Top drive rigs can include spaced guide rails and a drive frame movable along the guide rails and guiding the top drive power unit. The traveling block supports the drive frame through a hook and swivel, and the driving block is used to lower or raise the drive frame along the guide rails. For rotating the drill or well string, the top drive power unit includes a motor connected by gear means with a rotatable member both of which are supported by the drive frame.
During drilling operations, when it is desired to “trip” the drill pipe or well string into or out of the well bore, the drive frame can be lowered or raised. Additionally, during servicing operations, the drill string can be moved longitudinally into or out of the well bore.
The stem of the swivel communicates with the upper end of the rotatable member of the power unit in a manner well known to those skilled in the art for supplying fluid, such as a drilling fluid or mud, through the top drive unit and into the drill or work string. The swivel allows drilling fluid to pass through and be supplied to the drill or well string connected to the lower end of the rotatable member of the top drive power unit as the drill string is rotated and/or moved up and down.
Top drive rigs also can include elevators are secured to and suspended from the frame, the elevators being employed when it is desired to lower joints of drill string into the well bore, or remove such joints from the well bore.
At various times top drive operations, beyond drilling fluid, require various substances to be pumped downhole, such as cement, chemicals, epoxy resins, or the like. In many cases it is desirable to supply such substances at the same time as the top drive unit is rotating and/or moving the drill or well string up and/or down, but bypassing the top drive's power unit so that the substances do not damage/impair the unit. Additionally, it is desirable to supply such substances without interfering with and/or intermittently stopping longitudinal and/or rotational movement by the top drive unit of the drill or well string.
A need exists for a device facilitating insertion of various substances downhole through the drill or well string, bypassing the top drive unit, while at the same time allowing the top drive unit to rotate and/or move the drill or well string.
One example includes cementing a string of well bore casing. In some casing operations it is considered good practice to rotate the string of casing when it is being cemented in the wellbore. Such rotation is believed to facilitate better cement distribution and spread inside the annular space between the casing's exterior and interior of the well bore. In such operations the top drive unit can be used to both support and continuously rotate/intermittently reciprocate the string of casing while cement is pumped down the string's interior. During this time it is desirable to by-pass the top drive unit to avoid possible damage to any of its portions or components.
The following U.S. Patents are incorporated herein by reference: U.S. Pat. Nos. 4,722,389 and 7,007,753.
While certain novel features of this invention shown and described below are pointed out in the annexed claims, the invention is not intended to be limited to the details specified, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the spirit of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being “critical” or “essential.”
BRIEF SUMMARY
The apparatus of the present invention solves the problems confronted in the art in a simple and straightforward manner. One embodiment relates to an assembly having a top drive arrangement for rotating and longitudinally moving a drill or well string. In one embodiment is provided a swivel apparatus, the swivel generally comprising a mandrel and a sleeve with a packing configuration, the swivel being especially useful for top drive rigs.
In one embodiment the sleeve can be rotatably and sealably connected to the mandrel. The swivel can be incorporated into a drill or well string, enabling string sections both above and below the sleeve to be rotated in relation to the sleeve. Additionally, the swivel provides a flow path between the exterior of the sleeve and interior of the mandrel while the drill string is being rotated and/or being moved in a longitudinal direction (up or down). The interior of the mandrel can be fluidly connected to the longitudinal bore of the casing or drill string thereby providing a flow path from the exterior of the sleeve to the interior of the casing/drill string.
In one embodiment is provided a method and apparatus for servicing a well wherein a swivel is connected to a top drive unit for conveying pumpable substances from an external supply through the swivel for discharge into the well string and bypassing the top drive unit.
In another embodiment is provided a method of conducting servicing operations in a well bore, such as cementing, comprising the steps of moving a top drive unit rotationally and/or longitudinally to provide longitudinal movement and/or rotation in the well bore of a well string suspended from the top drive unit, rotating the drill or well string and supplying a pumpable substance to the well bore in which the drill or well string is manipulated by introducing the pumpable substance at a point below the top drive power unit and into the well string.
In other embodiments are provided a swivel placed below the top drive unit can be used to perform jobs such as spotting pills, squeeze work, open formation integrity work, kill jobs, fishing tool operations with high pressure pumps, sub-sea stack testing, rotation of casing during side tracking, and gravel pack or frack jobs. In still other embodiments a top drive swivel can be used in a method of pumping loss circulation material (LCM) into a well to plug/seal areas of downhole fluid loss to the formation and in high speed milling jobs using cutting tools to address down hole obstructions. In other embodiments the top drive swivel can be used with free point indicators and shot string or cord to free stuck pipe where pumpable substances are pumped downhole at the same time the downhole string/pipe/free point indicator is being rotated and/or reciprocated. In still other embodiments the top drive swivel can be used for setting hook wall packers and washing sand.
In still other embodiments the top drive swivel can be used for pumping pumpable substances downhole when repairs/servicing is being done to the top drive unit and rotation of the downhole drill string is being accomplished by the rotary table. Such use for rotation and pumping can prevent sticking/seizing of the drill string downhole. In this application safety valves, such as TIW valves, can be placed above and below the top drive swivel to enable routing of fluid flow and to ensure well control.
The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIGS. 1A and 1B are a schematic views showing a top drive rig with one embodiment of a top drive swivel incorporated in the drill string;
FIG. 2 is a perspective view of one embodiment of a top drive swivel;
FIG. 3 is a sectional view of a mandrel which can be incorporated in the swivel of FIG. 2 ;
FIG. 4 is a perspective view of a sleeve, clamp, and torque arm which can be incorporated into the swivel of FIG. 2 ;
FIG. 5 is an exploded view of the sleeve, clamp, and torque arm of FIG. 4 ;
FIG. 6 is a cutaway perspective view of the swivel of FIG. 2 ;
FIGS. 7A and 7B include a sectional view of the swivel of FIG. 2 along with an enlarged sectional view of the packing area;
FIG. 8 is an exploded view of a set of packing which can be incorporated into the swivel of FIG. 2 ;
FIG. 9 is a perspective view of a spacer;
FIG. 10 is a top view of the spacer of FIG. 9 ;
FIG. 11A is a sectional side view of the spacer of FIG. 9 ;
FIG. 11B is an enlarged sectional side view of the spacer of FIG. 9 ;
FIG. 12 is a perspective view of a female backup ring;
FIG. 13 is a top view of the female backup ring of FIG. 12 ;
FIG. 14A is a sectional side view of the female backup ring of FIG. 12 ;
FIG. 14B is an enlarged sectional side view of the female backup ring of FIG. 12 ;
FIG. 15 is a perspective view of a seal ring;
FIG. 16 is a top view of the seal ring of FIG. 15 ;
FIG. 17A is a sectional side view of the seal ring of FIG. 15 ;
FIG. 17B is an enlarged sectional side view of the seal ring of FIG. 15 ;
FIG. 18 is a perspective view of a rope seal;
FIG. 19 is a top view of the rope seal of FIG. 18 ;
FIG. 20A is a sectional side view of the rope seal of FIG. 18 ;
FIG. 20B is an enlarged sectional side view of the rope seal of FIG. 18 ;
FIG. 21 is a perspective view of a seal ring;
FIG. 22 is a top view of the seal ring of FIG. 21 ;
FIG. 23A is a sectional side view of the seal ring of FIG. 21 ;
FIG. 23B is an enlarged sectional side view of the seal ring of FIG. 21 ;
FIG. 24 is a perspective view of a seal ring;
FIG. 25 is a top view of the seal ring of FIG. 24 ;
FIG. 26A is a sectional side view of the seal ring of FIG. 24 ;
FIG. 26B is an enlarged sectional side view of the seal ring of FIG. 24 ;
FIG. 27 is a perspective view of a male backup ring;
FIG. 28 is a top view of the male backup ring of FIG. 27 ;
FIG. 29A is a sectional side view of the male backup ring of FIG. 27 ;
FIG. 29B is an enlarged sectional side view of the male backup ring of FIG. 27 ;
FIGS. 30A and 30B include a sectional view of another embodiment of the swivel of FIG. 2 along with an enlarged sectional view of the packing area;
FIG. 31 is an exploded view of a set of packing which can be incorporated into the swivel of FIG. 30A ;
FIG. 32 is a perspective view of a spacer;
FIG. 33 is a top view of the spacer of FIG. 32 ;
FIG. 34A is a sectional side view of the spacer of FIG. 32 ;
FIG. 34B is an enlarged sectional side view of the spacer of FIG. 32 ;
FIG. 35 is a perspective view of a female backup ring;
FIG. 36 is a top view of the female backup ring of FIG. 35 ;
FIG. 37A is a sectional side view of the female backup ring of FIG. 35 ;
FIG. 37B is an enlarged sectional side view of the female backup ring of FIG. 35 ;
FIG. 38 is a perspective view of a seal ring;
FIG. 39 is a top view of the seal ring of FIG. 38 ;
FIG. 40A is a sectional side view of the seal ring of FIG. 38 ;
FIG. 40B is an enlarged sectional side view of the seal ring of FIG. 38 ;
FIG. 41 is a perspective view of a rope seal;
FIG. 42 is a top view of the rope seal of FIG. 41 ;
FIG. 43A is a sectional side view of the rope seal of FIG. 41 ;
FIG. 43B is an enlarged sectional side view of the rope seal of FIG. 41 ;
FIG. 44 is a perspective view of a seal ring;
FIG. 45 is a top view of the seal ring of FIG. 44 ;
FIG. 46A is a sectional side view of the seal ring of FIG. 44 ;
FIG. 46B is an enlarged sectional side view of the seal ring of FIG. 44 ;
FIG. 47 is a perspective view of a seal ring;
FIG. 48 is a top view of the seal ring of FIG. 47 ;
FIG. 49A is a sectional side view of the seal ring of FIG. 47 ;
FIG. 49B is an enlarged sectional side view of the seal ring of FIG. 47 ;
FIG. 50 is a perspective view of a male backup ring;
FIG. 51 is a top view of the male backup ring of FIG. 50 ;
FIG. 52A is a sectional side view of the male backup ring of FIG. 50 ;
FIG. 52B is an enlarged sectional side view of the male backup ring of FIG. 50 ;
FIG. 53 shows an alternative combination swivel and ball dropper;
FIG. 54 shows one embodiment of the ball dropper for the combination swivel and ball dropper of FIG. 53 .
DETAILED DESCRIPTION
Detailed descriptions of one or more preferred embodiments are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in any appropriate system, structure or manner.
FIGS. 1A and 1B are schematic views showing a top drive rig 1 with one embodiment of a top drive swivel 30 incorporated into drill string 20 . FIG. 1A shows a rig 1 having a top drive unit 10 . Rig 1 comprises supports 16 , 17 ; crown block 2 ; traveling block 4 ; and hook 5 . Draw works 11 uses cable 12 to move up and down traveling block 4 , top drive unit 10 , and drill string 20 . Traveling block 4 supports top drive unit 10 . Top drive unit 10 supports drill string 20 .
During drilling operations, top drive unit 10 can be used to rotate drill string 20 which enters wellbore 14 . Top drive unit 10 can ride along guide rails 15 as unit 10 is moved up and down. Guide rails 15 prevent top drive unit 10 itself from rotating as top drive unit 10 rotates drill string 20 . During drilling operations drilling fluid can be supplied downhole through drilling fluid line 8 and gooseneck 6 .
As shown in FIG. 1B , during operations swivel 30 can be connected to rig 1 through clamp 600 and torque arm 630 . Torque are 630 can be pivotally connected to swivel 30 and can resist rotational movement of swivel sleeve 150 relative to rig 1 . Torque arm 630 can be slidably connected to rig 1 to allow a certain amount of longitudinal movement of swivel 30 with drill string 20 .
At various times top drive operations, beyond drilling fluid, require substances to be pumped downhole, such as cement, chemicals, epoxy resins, or the like. In many cases it is desirable to supply such substances at the same time as top drive unit 10 is rotating and/or moving drill or well string 20 up and/or down and bypassing top drive unit 10 so that the substances do not damage/impair top drive unit 10 . Additionally, it is desirable to supply such substances without interfering with and/or intermittently stopping longitudinal and/or rotational movements of drill or well string 20 being moved/rotated by top drive unit 10 . This can be accomplished by using top drive swivel 30 .
Top drive swivel 30 can be installed between top drive unit 10 and drill string 20 . One or more joints of drill pipe 18 can be placed between top drive unit 10 and swivel 30 . Additionally, a valve can be placed between top drive swivel 30 and top drive unit 10 . Pumpable substances can be pumped through hose 31 , swivel 30 , and into the interior of drill string 20 thereby bypassing top drive unit 10 . Top drive swivel 30 is preferably sized to be connected to drill string 20 such as 4½ inch (11.43 centimeter) IF API drill pipe or the size of the drill pipe to which swivel 30 is connected to. However, cross-over subs can also be used between top drive swivel 30 and connections to drill string 20 . Two sizes for swivel 30 will be addressed in this application—a 4½ inch (11.43 centimeter) version and a 6⅝ inch (16.83 centimeter) version.
FIG. 2 is a perspective view of one embodiment of a swivel 30 . Swivel 30 can be comprised of mandrel 40 and sleeve 150 . Sleeve 150 can be rotatably and sealably connected to mandrel 40 . Accordingly, when mandrel 40 is rotated, sleeve 150 can remain stationary to an observer insofar as rotation is concerned. As will be discussed later inlet 200 of sleeve 150 is and remains fluidly connected to a the central longitudinal passage 90 of mandrel 40 . Accordingly, while mandrel 40 is being rotated and/or moved up and down pumpable substances can enter inlet 200 and exit central longitudinal passage 90 at lower end 60 of mandrel 40 .
FIG. 3 is a sectional view of mandrel 40 which can be incorporated in swivel 30 . Mandrel 40 can be comprised of upper end 50 and lower end 60 . Central longitudinal passage 90 can extend from upper end 50 through lower end 60 . Lower end 60 can include a pin connection 80 or any other conventional connection. Upper end 50 can include box connection 70 or any other conventional connection. Mandrel 40 can in effect become a part of drill string 20 . Sleeve 150 can fit over mandrel 40 and become rotatably and sealably connected to mandrel 40 . Mandrel 40 can include shoulder 100 to support sleeve 150 . Mandrel 40 can include one or more radial inlet ports 140 fluidly connecting central longitudinal passage 90 to recessed area 130 . Recessed area 130 preferably forms a circumferential recess along the perimeter of mandrel 40 and between packing support areas 131 , 132 . In such manner recessed area 130 will remain fluidly connected with radial passage 190 and inlet 200 of sleeve 150 (see FIGS. 6 and 7A ).
Mandrel 40 takes substantially all of the structural load from drill string 20 . In one embodiment the overall length of mandrel 40 is preferably 52 and 5/16 inches (132.87 centimeters). Mandrel 40 can be machined from a single continuous piece of heat treated steel bar stock. NC50 is preferably the API Tool Joint Designation for the box connection 70 and pin connection 80 . Such tool joint designation is equivalent to and interchangeable with 4½ inch (11.43 centimeter) IF (Internally Flush), 5 inch (12.7 centimeter) XH (Extra Hole) and 5½ inch (13.97 centimeter) DSL (Double Stream Line) connections. Additionally, it is preferred that the box connection 70 and pin connection 80 meet the requirements of API specifications 7 and 7G for new rotary shouldered tool joint connections having 6⅝ inch (16.83 centimeters) outer diameter and a 2¾ inch (6.99 centimeter) inner diameter. The Strength and Design Formulas of API 7G—Appendix A provides the following load carrying specification for mandrel 40 of top drive swivel 30 : (a) 1,477,000 pounds (6,570 kilo newtons) tensile load at the minimum yield stress; (b) 62,000 foot-pounds (84 kilo newton meters) torsional load at the minimum torsional yield stress; and (c) 37,200 foot-pounds (50.44 kilo newton meters) recommended minimum make up torque. Mandrel 40 can be machined from 4340 heat treated bar stock.
In another embodiment, Mandrel 40 takes substantially all of the structural load from drill string 20 . In one embodiment the overall length of mandrel 40 is preferably 67 and 13/16 inches (172.24 centimeters). Mandrel 40 can be machined from a single continuous piece of heat treated steel bar stock. 6⅝ inch (16.83 centimeters) FH is preferably the API Tool Joint Designation for the box connection 70 and pin connection 80 . Additionally, it is preferred that the box connection 70 and pin connection 80 meet the requirements of API specifications 7 and 7G for new rotary shouldered tool joint connections having 8½ inch (21.59 centimeter) outer diameter and a 4¼ inch (10.8 centimeter) inner diameter. The Strength and Design Formulas of API 7G—Appendix A provides the following load carrying specification for mandrel 40 of top drive swivel 30 : (a) 2,094,661 pounds (9,318 kilo newtons) tensile load at the minimum yield stress; (b) 109,255 foot-pounds (148.1 kilo newton meters) torsion load at the minimum torsional yield stress; and (c) 65,012 foot-pounds (88.14 kilo newton meters) recommended minimum make up torque. Mandrel 40 can be machined from 4340 heat treated bar stock.
To reduce friction between mandrel 40 and packing units 305 , 405 and increase the life expectancy of packing units 305 , 405 , packing support areas 131 , 132 can be coated and/or sprayed welded with a materials of various compositions, such as hard chrome, nickel/chrome or nickel/aluminum (95 percent nickel and 5 percent aluminum) A material which can be used for coating by spray welding is the chrome alloy TAFA 95MX Ultrahard Wire (Armacor M) manufactured by TAFA Technologies, Inc., 146 Pembroke Road, Concord N.H. TAFA 95 MX is an alloy of the following composition: Chromium 30 percent; Boron 6 percent; Manganese 3 percent; Silicon 3 percent; and Iron balance. The TAFA 95 MX can be combined with a chrome steel. Another material which can be used for coating by spray welding is TAFA BONDARC WIRE-75B manufactured by TAFA Technologies, Inc. TAFA BONDARC WIRE-75B is an alloy containing the following elements: Nickel 94 percent; Aluminum 4.6 percent; Titanium 0.6 percent; Iron 0.4 percent; Manganese 0.3 percent; Cobalt 0.2 percent; Molybdenum 0.1 percent; Copper 0.1 percent; and Chromium 0.1 percent. Another material which can be used for coating by spray welding is the nickel chrome alloy TAFALOY NICKEL-CHROME-MOLY WIRE-71T manufactured by TAFA Technologies, Inc. TAFALOY NICKEL-CHROME-MOLY WIRE-71T is an alloy containing the following elements: Nickel 61.2 percent; Chromium 22 percent; Iron 3 percent; Molybdenum 9 percent; Tantalum 3 percent; and Cobalt 1 percent. Various combinations of the above alloys can also be used for the coating/spray welding. Packing support areas 131 , 132 can also be coated by a plating method, such as electroplating. The surface of support areas 131 , 132 can be ground/polished/finished to a desired finish to reduce friction and wear between support areas 131 , 132 and packing units 305 , 415 .
FIG. 4 is a perspective view of a sleeve 150 , clamp 600 , and torque arm 630 which can be incorporated into swivel 30 . FIG. 5 is an exploded view of the components shown in FIG. 4 . FIG. 6 is a cutaway perspective view of swivel 30 . FIG. 7A is a sectional view of swivel 30 taken along the line 7 A- 7 A of FIG. 6 .
FIG. 6 is an overall perspective view (and partial sectional view) of top drive swivel 30 . Sleeve 150 is shown rotatably connected to mandrel 40 . Bearings 145 , 146 allow sleeve 150 to rotate in relation to mandrel 40 . Packing units 305 , 405 sealingly connect sleeve 150 to mandrel 40 . Retaining nut 800 retains sleeve 150 on mandrel 40 . Inlet 200 of sleeve 150 is fluidly connected to central longitudinal passage 90 of mandrel 40 . Accordingly, while mandrel 40 is being rotated and/or moved up and down pumpable substances can enter inlet 200 and exit central longitudinal passage 90 at lower end 60 of mandrel 40 . Recessed area 130 forms a peripheral recess between mandrel 40 and sleeve 150 . The fluid pathway from inlet 200 to outlet at lower end 60 of central longitudinal passage 90 is as follows: entering inlet 200 ; passing through radial passage 190 ; passing through recessed area 130 ; passing through one of the plurality of radial inlet ports 40 ; passing through central longitudinal passage 90 ; and exiting mandrel 40 through central longitudinal passage 90 at lower end 60 and pin connection 80 .
Sleeve 150 can include central longitudinal passage 180 extending from upper end 160 through lower end 170 . Sleeve 150 can also include radial passage 190 and inlet 200 . Inlet 200 can be attached by welding or any other conventional type method of fastening such as a threaded connection. If welded the connection is preferably heat treated to remove residual stresses created by the welding procedure. Lubrication port 210 (not shown) can be included to provide lubrication for interior bearings. Packing ports 220 , 230 can also be included to provide the option of injecting packing material into the packing units 305 , 405 . A protective cover 240 can be placed around packing port 230 to protect packing injector 235 . Optionally, a second protective cover can be placed around packing port 220 . Sleeve 150 can include a groove 691 for insertion of a key 700 . FIG. 7A illustrates how central longitudinal passage 90 is fluidly connected to inlet 200 through radial passage 190 .
Sleeve 150 slides over mandrel 40 . Bearings 145 , 146 rotatably connect sleeve 150 to mandrel 40 . Bearings 145 , 146 are preferably thrust bearings although many conventionally available bearing will adequately function, including conical and ball bearings. Packing units 305 , 405 sealingly connect sleeve 150 to mandrel 40 . Inlet 200 of sleeve 150 is and remains fluidly connected to central longitudinal passage 90 of mandrel 40 . Accordingly, while mandrel 40 is being rotated and/or moved up and down pumpable substances can enter inlet 200 and exit central longitudinal passage 90 at lower end 60 of mandrel 40 . Recessed area 130 forms a peripheral recess between mandrel 40 and sleeve 150 . The fluid pathway from inlet 200 to outlet at lower end 60 of central longitudinal passage 90 is as follows: entering inlet 200 (arrow 201 ); passing through radial passage 190 (arrow 202 ); passing through recessed area 130 (arrow 202 ); passing through one of the plurality of radial inlet ports 140 (arrow 202 ), passing through central longitudinal passage 90 (arrow 203 ); and exiting mandrel 40 via lower end 60 at pin connection 80 (arrows 204 , 205 ).
Sleeve 150 is preferably fabricated from 4140 heat treated round mechanical tubing having the following properties: (120,000 psi (827,400 kilo pascal) minimum tensile strength, 100,000 psi (689,500 kilo pascal) minimum yield strength, and 285/311 Brinell Hardness Range). In one embodiment the external diameter of sleeve 150 is preferably about 11 inches (27.94 centimeters). Sleeve 150 preferably resists high internal pressures of fluid passing through inlet 200 . Preferably top drive swivel 30 with sleeve 150 will withstand a hydrostatic pressure test of 12,500 psi (86,200 kilo pascal). At this pressure the stress induced in sleeve 150 is preferably only about 24.8 percent of its material's yield strength. At a preferable working pressure of 7,500 psi (51,700 kilo pascal), there is preferably a 6.7:1 structural safety factor for sleeve 150 .
To minimize flow restrictions through top drive swivel 30 , large open areas 140 are preferred. Preferably each area of interest throughout top drive swivel 30 is larger than the inlet service port area 200 . Inlet 200 is preferably 3 inches having a flow area of 4.19 square inches (27.03 square centimeters). In one embodiment the flow area of the annular space between sleeve 150 and mandrel 40 is preferably 20.81 square inches (134.22 square centimeters). The flow area through the plurality of radial inlet ports 140 is preferably 7.36 square inches (47.47 square centimeters). The flow area through central longitudinal bore 90 is preferably 5.94 square inches 38.31 square centimeters).
Retainer nut 800 can be used to maintain sleeve 150 on mandrel 40 . Retainer nut 800 can threadably engage mandrel 40 at threaded area 801 . Set screw 890 can be used to lock in place retainer nut 800 and prevent nut 800 from loosening during operation. A set screw 890 (not shown for clarity) can threadably engages retainer nut 800 through bore 900 (not shown for clarity) and sets in one of a plurality of receiving portions 910 formed in mandrel 40 . Retaining nut 800 can also include grease injection fitting 880 for lubricating bearing 145 . A wiper ring 271 (not shown for clarity) can be set in area 270 protects against dirt and other items from entering between the sleeve 150 and mandrel 40 . A grease ring 291 (not shown for clarity) can be set in area 290 for holding lubricant for bearing 145 .
Bearing 146 can be lubricated through a grease injection fitting 211 and lubrication port 210 (not shown for clarity).
FIGS. 4 and 5 best show clamp 600 which can be incorporated into top drive swivel 30 . FIG. 5 is an exploded view of clamp 600 . Clamp 600 can comprises first portion 610 , second portion 620 , and third portion 625 . First, second, and third portions 610 , 620 , 625 can be removably attached by plurality of fasteners 670 , 680 . Key 700 can be inserted in keyway 690 of clamp 600 . A corresponding keyway 691 is included in sleeve 150 of top drive swivel 30 . Keyways 690 , 691 and key 700 prevent clamp 600 from rotating relative to sleeve 150 . A second key 720 can be installed in keyways 710 , 711 . Third, fourth, and additional keys/keyways can be used as desired.
Shackles can be attached to clamp 600 to facilitate handing top drive swivel 30 when clamp 600 is attached. Torque arm 630 can be pivotally attached to clamp 600 and allow attachment of clamp 600 (and sleeve 150 ) to a stationary part of top drive rig 1 preventing sleeve 150 from rotating while drill string 20 is being rotated by top drive 10 (and top drive swivel 30 is installed in drill string 20 ). Torque arm 630 can be provided with holes for attaching restraining shackles. Restrained torque arm 630 prevents sleeve 150 from rotating while mandrel 40 is being spun. Otherwise, frictional forces between packing units 305 , 405 and packing support areas 131 , 135 of rotating mandrel 40 would tend to also rotate sleeve 150 . Clamp 600 is preferably fabricated from 4140 heat treated steel being machined to fit around sleeve 150 .
FIG. 8 shows a blown up schematic view of packing unit 305 . FIG. 7B shows a sectional view through packing area 305 . Packing unit 305 can comprise female packing end 330 ; packing ring 340 , packing lubrication ring 350 , packing ring 360 , packing ring 370 , and packing end 380 . Packing unit 305 sealing connects mandrel 40 and sleeve 150 . Packing unit 305 can be encased by packing retainer nut 310 , spacer 320 , and shoulder 156 of protruding section 155 . Packing retainer nut 310 can be a ring which threadably engages sleeve 150 at threaded area 316 . Packing retainer nut 310 and shoulder 156 squeeze packing unit 305 to obtain a good seal between mandrel 40 and sleeve 150 . Set screw 315 can be used to lock packing retainer nut 310 in place and prevent retainer nut 310 from loosening during operation. Set screw 315 can be threaded into bore 314 and lock into receiving area 317 on sleeve 150 . Packing unit 405 (shown in FIG. 7A ) can be constructed substantially similar to packing unit 305 . The materials for packing unit 305 and packing unit 405 can be similar.
Spacer 320 can comprise, first end 322 , second end 324 , internal surface 326 , and external surface 328 . Spacer 320 can be sized based on the amount of squeezed to be applied to packing unit 305 when packing retainer nut 310 is tightened. It is preferably fabricated or machined from bronze.
Packing end 330 is preferably a female packing end comprised of a bearing grade peak or stiffened bronze material. Female packing ring or end 330 can comprise tip 332 with concave portion 331 . Concave portion 331 can have an angle of about 130 degrees at its center. Tip 332 can include side 333 , recessed area 334 , peripheral groove 337 and inner diameter 335 . Recessed area 334 and inner diameter 335 can be configured to minimize contact of female packing ring or end 330 with mandrel 40 . Instead, contact will be made between packing ring 340 and mandrel 40 . It is believed that minimizing contact between female packing ring or end 330 and mandrel 40 will reduce heat buildup from friction and extend the life of the packing unit. It is also believed that packing ring 340 performs the great majority of sealing against high pressure fluids (such as pressures above about 3,000 or about 4,000 psi (20,700 kilo pascals or 27,600 kilo pascals)). It is also believed that packing rings 370 and/or 360 perform the majority of sealing against lower pressure fluids. Female packing ring 330 can include a plurality of radial ports 336 fluidly connecting peripheral groove 337 with interior groove 338 to allow packing injected to evenly distribute around ring and into the actual sealing rings.
Packing ring 340 can comprise tip 342 , base 344 , internal surface 346 , and external surface 348 . Tip 342 can have an angle of about 120 degrees to have an non-interference fit with tip 332 of female packing end 330 which is at about 130 degrees Base 344 can have an angle of about 120 degrees. Packing ring 340 is preferably a “Vee” packing ring—comprised of bronze filled teflon such as that supplied by CDI material number 714 . Tip 342 of packing ring 340 is made at about 120 degrees (which is blunter than the conventional 90 degree tips) in an attempt to limit the braking effect (e.g., caused by expansion of recessed area 334 of the female packing ring or end 330 which would cause side 333 of female packing ring to contact mandrel 40 ) on mandrel 40 when longitudinal force is applied through the packing Base 344 being at about 120 degrees is believed to assist in causing packing ring 340 to bear against mandrel 40 , and not side 333 of female packing ring 330 .
Packing lubrication ring 350 , preferably includes at least one rope seal such as a Garlock ½ inch (or 7/16 inch or ⅜ inch) (1.27 centimeters, or 1.11 centimeters, or 0.95 centimeters) section 8913 Rope Seal. Rope seals have surprisingly been found to extend the life of other seals in the packing unit. This is thought to be by secretion of lubricants, such as graphite, during use over time. Although shown in a “Vee” type shape, rope seals typically have a square cross section and form to the shape of the area to which they are confined. Here, lubrication ring 350 is shown after be shaped by packing rings 340 and 360 .
Packing ring 360 can comprise tip 362 , base 364 , internal surface 366 , and external surface 368 . Tip 362 can have an angle of about 90 degrees. Base 364 can have an angle of about 120 degrees. 90 degrees for the tip and 120 degrees for the base are conventional angles. The larger angle for the base allows thermal expansion of the tip in the base. Packing ring 360 is preferably a “Vee” packing ring—comprised of hard rubber such as that supplied by CDI material number 850 or viton such as that supplied by CDI material number 951 .
Packing rings 360 , 370 can have substantially the same geometric construction. Packing ring 370 can comprise tip 372 , base 374 , internal surface 376 , and external surface 378 . Tip 372 can have an angle of about 90 degrees. Base 374 can have an angle of about 120 degrees. 90 degrees for the tip and 120 degrees for the base are conventional angles. The larger angle for the base allows thermal expansion of the tip in the base. Packing ring 370 is preferably a “Vee” packing ring—comprised of teflon such as that supplied by CDI material number 711 .
In an alternative embodiment both packing rings 360 and 370 are “Vee” packing rings—comprised of teflon such as that supplied by CDI material number 711 .
In another alternative embodiment packing ring 370 can be a “Vee” packing ring—comprised of hard rubber such as that supplied by CDI material number 850 or viton such as that supplied by CDI material number 951 ; and Packing ring 360 can be a “Vee” packing ring—comprised of teflon such as that supplied by CDI material number 711 .
Male packing end or ring 380 can comprise tip 382 , base 384 , internal surface 386 , and external surface 388 . Tip 382 can have an angle of about 90 degrees. Packing end 380 is preferably an aluminum bronze male packing ring.
Various alternative materials for packing rings can be used such as standard chevron packing rings of standard packing materials.
Using the above packing configuration it has been surprisingly found that packing life in a displacement job at high pressure can be extended from about 45 minutes to about 10 hours, at rotation speeds of about 30, about 40, about 50, and about 60 revolutions per minute.
In installing packing units 305 , 405 , it has been found that the packing units should first be compressed in a longitudinal direction between sleeve 150 and a dummy cylinder (the dummy cylinder serving as mandrel 40 ) before sleeve 150 is installed on mandrel 40 . This is because a certain amount of longitudinal compression of packing units 305 , 405 will occur when fluid pressure is first exerted on these packing units. This longitudinal compression will be taken up by the respective packing retainer nuts 310 . However, using a dummy cylinder allows the individual packing retainer nuts 310 to cause pre-fluid pressure longitudinal compression on packing units 305 , 405 , but still allow the seals to maintain an internal diameter consistent with the external diameter of mandrel 40 . Such a procedure can avoid the requirement of resetting the individual packing retainer nuts 310 after fluid pressure is applied to the packing units causing longitudinal compression.
Female packing ring or end 330 can include a packing injection option. Injection fitting 225 can be used to inject additional packing material such as teflon into packing unit 305 . Head 226 for injection fitting 225 can be removed and packing material can then be inserted into fitting 225 . Head 226 can then be screwed back into injection fitting 225 which would push packing material through fitting 225 and into packing port 220 . The material would then be pushed into packing ring or end 330 . Packing ring or end 330 can comprise a plurality of radial ports 336 , outer peripheral groove 337 , and inner peripheral groove 338 . The material would proceed through outer groove 337 , through the plurality of radial ports 336 , and through inner peripheral groove 338 causing a sealing effect. The interaction between injection fitting 235 and packing unit 405 can be substantially similar to the interaction between injection fitting 225 and packing unit 305 . A conventionally available material which can be used for packing injection fittings 225 , 235 is DESCO™ 625 Pak part number 6242-12 in the form of a 1 inch by ⅜ inch (2.54 centimeter by 0.95 centimeter) stick and distributed by Chemola Division of South Coast Products, Inc., Houston, Tex.
Injection fittings 225 , 235 have a dual purpose: (a) provide an operator a visual indication whether there has been any leakage past either packing units 305 , 405 and (b) allow the operator to easily inject additional packing material and stop seal leakage without removing top drive swivel 30 from drill string 20 .
FIGS. 30A through 50 show an alternative packing arrangement for packing units 305 , 405 . In this alternative arrangement spacer 420 can include a plurality of radial ports for injecting packing filler material.
FIG. 31 shows a blown up schematic view of packing unit 405 . FIG. 30B shows a sectional view through packing unit 405 . Packing unit 405 can comprise female packing end 430 ; packing ring 440 , packing lubrication ring 450 , packing ring 460 , packing ring 470 , and packing end 480 . Packing unit 405 sealing connects mandrel 40 and sleeve 150 . Packing unit 405 can be encased by packing retainer nut 310 , spacer 420 , and shoulder 156 of protruding section 155 . Packing retainer nut 310 can be a ring which threadably engages sleeve 150 at threaded area 316 . Packing retainer nut 310 and shoulder 156 squeeze packing unit 405 to obtain a good seal between mandrel 40 and sleeve 150 . Set screw 315 can be used to lock packing retainer nut 310 in place and prevent retainer nut 310 from loosening during operation. Set screw 315 can be threaded into bore 314 and lock into receiving area 317 on sleeve 150 . An upper packing unit can be constructed substantially similar to packing unit 405 . The materials for packing unit 405 and upper packing unit can be similar.
Spacer 420 can comprise, first end 421 , second end 422 , internal surface 423 , and external surface 424 . Spacer 420 can be sized based on the amount of squeezed to be applied to packing unit 405 when packing retainer nut 310 is tightened. It is preferably fabricated or machined from bronze.
Packing end 430 is preferably a female packing end comprised of a bearing grade peak or stiffened bronze material. Female packing ring or end 430 can comprise tip 432 with concave portion 431 . Concave portion 431 can have an angle of about 130 degrees at its center. Tip 442 can include side 433 , recessed area 44 , peripheral groove 47 and inner diameter 445 . Recessed area 434 and inner diameter 435 can be configured to minimize contact of female packing ring or end 430 with mandrel 40 . Instead, contact will be made between packing ring 440 and mandrel 40 . It is believed that minimizing contact between female packing ring or end 430 and mandrel 40 will reduce heat buildup from friction and extend the life of the packing unit. It is also believed that packing ring 440 performs the great majority of sealing against high pressure fluids (such as pressures above about 3,000 or about 4,000 psi) (20,700 kilo pascals or 27,600 kilo pascals). It is also believed that packing rings 470 and/or 460 perform the majority of sealing against lower pressure fluids.
Packing ring 440 can comprise tip 442 , base 444 , internal surface 446 , and external surface 448 . Tip 442 can have an angle of about 120 degrees to have an non-interference fit with tip 432 of female packing end 430 which is at about 130 degrees Base 444 can have an angle of about 120 degrees. Packing ring 440 is preferably a “Vee” packing ring—comprised of bronze filled teflon such as that supplied by CDI material number 714 . Tip 442 of packing ring 440 is made at about 120 degrees (which is blunter than the conventional 90 degree tips) in an attempt to limit the braking effect (e.g., caused by expansion of recessed area 434 of the female packing ring or end 430 which would cause side 433 of female packing ring to contact mandrel 40 ) on mandrel 40 when longitudinal force is applied through the packing Base 444 being at about 120 degrees is believed to assist in causing packing ring 440 to bear against mandrel 40 , and not side 433 of female packing ring 430 .
Packing lubrication ring 450 , preferably includes at least one rope seal such as a Garlock ½ inch (or 7/16 inch or ⅜ inch) (1.27 centimeters, or 1.11 centimeters, or 0.95 centimeters) section 8913 Rope Seal. Rope seals have surprisingly been found to extend the life of other seals in the packing unit. This is thought to be by secretion of lubricants, such as graphite, during use over time. Although shown in a “Vee” type shape, rope seals typically have a square cross section and form to the shape of the area to which they are confined. Here, lubrication ring 450 is shown after being shaped by packing rings 440 and 460 .
Packing ring 460 can comprise tip 462 , base 464 , internal surface 466 , and external surface 468 . Tip 462 can have an angle of about 90 degrees. Base 464 can have an angle of about 120 degrees. 90 degrees for the tip and 120 degrees for the base are conventional angles. The larger angle for the base allows thermal expansion of the tip in the base. Packing ring 460 is preferably a “Vee” packing ring—comprised of hard rubber such as that supplied by CDI material number 850 or viton such as that supplied by CDI material number 951 .
Packing rings 460 , 470 can have substantially the same geometric construction. Packing ring 470 can comprise tip 472 , base 474 , internal surface 476 , and external surface 478 . Tip 472 can have an angle of about 90 degrees. Base 474 can have an angle of about 120 degrees. 90 degrees for the tip and 120 degrees for the base are conventional angles. The larger angle for the base allows thermal expansion of the tip in the base. Packing ring 470 is preferably a “Vee” packing ring—comprised of teflon such as that supplied by CDI material number 711 .
In an alternative embodiment both packing rings 460 and 470 are “Vee” packing rings—comprised of teflon such as that supplied by CDI material number 711 .
In another alternative embodiment packing ring 470 can be a “Vee” packing ring—comprised of hard rubber such as that supplied by CDI material number 850 or viton such as that supplied by CDI material number 951 ; and Packing ring 460 can be a “Vee” packing ring—comprised of teflon such as that supplied by CDI material number 711 .
Male packing end or ring 480 can comprise tip 482 , base 484 , internal surface 486 , and external surface 488 . Tip 482 can have an angle of about 90 degrees. Packing end 480 is preferably an aluminum bronze male packing ring.
Various alternative materials for packing rings can be used such as standard chevron packing rings of standard packing materials.
FIG. 53 shows an alternative combination swivel and ball dropper.
FIG. 54 shows one embodiment of the ball dropper for the combination swivel and ball dropper of FIG. 53 .
The following is a list of reference numerals:
LIST FOR REFERENCE NUMERALS
(Part No.)
(Description)
Reference Numeral
Description
1
rig
2
crown block
3
cable means
4
travelling block
5
hook
6
gooseneck
7
swivel
8
drilling fluid line
10
top drive unit
11
draw works
12
cable
13
rotary table
14
well bore
15
guide rail
16
support
17
support
18
drill pipe
19
drill string
20
drill string or work string
30
swivel
31
hose
40
swivel mandrel
50
upper end
60
lower end
70
box connection
80
pin connection
90
central longitudinal passage
100
shoulder
110
interior surface
120
external surface (mandrel)
130
recessed area
131
packing support area
132
packing support area
140
radial inlet ports (a plurality)
145
bearing
146
bearing
150
swivel sleeve
155
protruding section
156
shoulder
157
shoulder
158
packing support area
159
packing support area
160
upper end
170
lower end
180
central longitudinal passage
190
radial passage
200
inlet
201
arrow
202
arrow
203
arrow
204
arrow
205
arrow
210
lubrication port
211
grease injection fitting
220
packing port
225
injection fitting
226
head
230
packing port
235
injection fitting
240
cover
250
upper shoulder
260
lower shoulder
270
area for wiper ring
271
wiper ring (preferably Parker part number
959-65)
280
area for wiper ring
281
wiper ring (preferably Parker part number
959-65)
290
area for grease ring
291
grease ring (preferably Parker part number
2501000 Standard Polypak)
300
area for grease ring
301
grease ring (preferably Parker part number
2501000 Standard Polypak)
305
packing unit
310
packing retainer nut
314
bore for set screw
315
set screw for packing retainer nut
316
threaded area
317
set screw for receiving area
320
spacer
322
first end
324
second end
326
internal surface
328
external surface
330
female packing end and packing injection
ring
331
concave portion
332
tip
333
side
334
recessed area
335
inner diameter
336
radial port
337
peripheral groove
338
interior groove
340
packing ring
342
tip
344
base
346
internal surface
348
external surface
350
packing ring
360
packing ring
362
tip
364
base
366
internal surface
368
external surface
370
packing ring
372
tip
374
base
376
internal surface
378
external surface
380
packing end
382
tip
384
base
386
internal surface
388
external surface
405
packing unit
410
packing retainer nut
414
bore for set screw
415
set screw for packing retainer nut
416
threaded area
417
set screw for receiving area
420
spacer and packing injection ring
421
first end
422
second end
423
internal surface
424
external surface
437
radial port
438
peripheral groove
439
interior groove
430
female packing end
431
concave portion
432
tip
433
side
434
recessed area
435
inner diameter
436
external diameter
440
packing ring
442
tip
444
base
446
internal surface
448
external surface
450
packing ring
460
packing ring
462
tip
464
base
466
internal surface
468
external surface
470
packing ring
472
tip
474
base
476
internal surface
478
external surface
480
packing end
482
tip
484
base
486
internal surface
488
external surface
600
clamp
605
groove
610
first portion
620
second portion
625
third portion
630
torque arm
650
shackle
660
shackle
670
plurality of fasteners
680
plurality of fasteners
690
keyway
691
keyway
700
key
710
keyway
711
keyway
720
key
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
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For use with a top drive power unit supported for connection with a well string in a well bore to selectively impart longitudinal and/or rotational movement to the well string, a feeder for supplying a pumpable substance such as cement and the like from an external supply source to the interior of the well string in the well bore without first discharging it through the top drive power unit including a mandrel extending through a sleeve which is sealably and rotatably supported thereon for relative rotation between the sleeve and mandrel. The mandrel and sleeve have flow passages for communicating the pumpable substance from an external source to discharge through the sleeve and mandrel and into the interior of the well string below the top drive power unit. The unit can include a packing injection system and novel seal configuration.
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RELATED APPLICATION
This application is a continuation of my application Ser. No. 284,349, filed Aug. 28, 1972, now abandoned for PLASTIC BOOK COVER AND METHOD OF MAKING.
BACKGROUND AND SUMMARY OF THE INVENTION
Covers made in accordance with this invention each consist of a front panel and a back panel joined by an intermediate backbone panel for covering the front, back and backbone, respectively, of a book. Each cover is formed by a relatively thin flexible base sheet of plastic material which has another layer or layers of plastic at least on the portions defining the front and back panels and alternately also on the backbone portion, to stiffen these portions.
The flexibility of the base layer enables the front and back panels to swing on the backbone portion for opening and closing the book. If the backbone portion of the cover is also provided with a thickening layer to stiffen it, spaces left between the edges of panel-thickening layers and the adjacent edges of the backbone thickening layer provide hinge lines therebetween.
The first and second layers can be extruded with the second layer applied to the first layer while the first layer is semi-molten or at a temperature that insures a substantial welding of one layer to the other. Alternatively, the first layer can be applied to a casting paper or belt by a coater such as a reverse roll coating means with plastisol or other plastic material coming from a supply trough. The base layer can be gelled on the casting surface and then additional material can be applied selectively to portions of the base layer by a metering roll or other apparatus that will supply a second stiffening layer locally to those areas of the first layer that are to be the front and back panels, and the backbone panel, if desired.
If the plastic material supplied by the first applicator is a plastisol, an oven, and preferably a two-stage oven, is used to gel the plastisol before passing it to the next "coating" station. The composite is then cured. Where the material is to be decorated on either surface of the cover, the material is passed through an embossing or contouring roll pass while the material is still warm enough to be permanently deformed in accordance with the contour of the embossing roll.
In describing the invention, the plastic material will be said to be applied in a "fluid state", this expression being used herein to designate polymeric materials or compositions including material such as plastisols, which are non-solid; and also high viscosity fluids of a consistency such as a molten or semi-molten and bondable extrudate.
THE PRIOR ART
Plastic bookcovers of the two-layer type are known and a method of manufacturing them is disclosed in U.S. Pat. No. 3,168,424, dated Feb. 2, 1965. As disclosed therein, the book covers are formed by flowing the thickening plastic material onto a previously formed web of plastic material which provides the flexible base layer. The thickening material is flowed on in parallel strips corresponding in width to the width desired for the front and back panels, respectively, of the cover; and for the backbone panel, if the backbone panel is to be stiffened. The strips are spaced apart to provide hinge lines between the panels and on which the front and back panels can swing when opening and closing the book. The web is heated sufficiently for the stiffening material to become bonded to the underlying previously formed web and the composite web is cut into lengths corresponding to the height of the book covers to be formed.
This method of the prior art does not give the effective bond of the present invention, nor does it provide the same choice of materials. For example, unless the base sheet of the prior art is cast, and such sheets involve added cost, the prior art method cannot be used with a two-layer material that requires curing because of distortion of the base layer when subject to the heat of a curing oven. The present invention can be used with polyvinyl chloride which has the advantage that it can be used with dielectric heat.
The present invention greatly reduces the necessary inventory of the cover maker. Different thickenesses of the base layer can be obtained by merely adjusting an extruder die or coater, and no stock of preformed sheets of different thickness is necessary to obtain different thickness for the hinge lines. Change in color, thickness, stiffness and pattern can be easily obtained without carrying any inventory of preformed sheets of different colors, thickness and stiffness.
Other features and advantages of the invention will appear or be pointed out as the description proceeds.
BRIEF DESCRIPTION OF DRAWING
In the drawing forming a part hereof, in which like reference characters indicate corresponding parts in all the views:
FIG. 1 is an isometric view showing a cover, made in accordance with this invention, with the cover in open position;
FIG. 1A is a fragmentary view of a cover, such as shown in FIG. 1, but with stiffening material applied to the backbone panel;
FIG. 2 is an isometric view of the cover shown in FIG. 1 with a filler in the cover and showing a completed book;
FIGS. 3A and 3B are a diagrammatic side elevation of the apparatus used for making the covers of this invention;
FIGS. 4, 5 and 6 are sectional views taken on the lines 4--4, 5--5, and 6--6, respectively of FIG 3A;
FIG. 7 is a diagrammatic view showing a modified form of the construction which is illustrated in FIGS. 3A and 3B;
FIGS. 8 and 9 are enlarged, diagrammatic views of the applicators shown in FIG. 7 for applying the first and second layers of plastic to a casting surface;
FIG. 10 is a fragmentary view, partly in section, taken on the line 10--10 of FIG. 9; and
FIG. 11 is a sectional view through the modified form of cover shown in FIG. 1A, and illustrating the way in which the front and back panels hinge to close the book to which the cover is applied.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 shows a book cover 10 including a front panel 12, a back panel 14 and an intermediate backbone panel 16 which connects the front and back panels 12 and 14, respectively. The cover is made of a first layer 18 of plastic material which has the desired stiffness for the hinge lines of the cover; that is, the lines at which the front and back panels swing with respect to the backbone panel when the book opens and closes. The front and back panels 12 and 14 include a second layer 20 and 22, respectively, which stiffen the front and back panels to make them hard covers or semi-rigid covers or whatever other degree of stiffness is desired.
FIG. 1A shows a cover 10' which is the same as the cover 10 except that the backbone panel is stiffened. In FIG. 1A parts corresponding to the parts in FIG. 1 are designated by the same reference characters with a prime appended and the backbone panel 16' is made with a second layer 24 bonded to the first layer 18'. Whether or not a stiffening layer 28 is used with the backbone panel depends upon the type of binding to be used and whether the cover is to be a tight-back cover or not.
FIG. 2 shows a book 26 to which the cover 10' is applied. The cover has been applied to a filler 28 with the backbone panel 16' adhered to the backbone of the filler 28 to make a tight back book. The front and back panels 12' and 14' are decorated by embossing or other surface treatment indicated by the reference character 30. This is shown on the back cover 14', the surface of the front cover 12 not being visible in FIG. 2. In FIG. 2 the book is shown with the cover closed and the hinge lines are indicated by the reference character 32.
FIGS. 3A and 3B show the way in which the covers of FIG. 1 and 1A are made. An endless steel belt 32 passes around rolls 34, 34a and 35 supported by suitable axles. This belt 32 passes across a support. Axles 41 of rolls 34-35 are rotated by a motor or other means at a suitable speed.
The first layer of plastic material 18 is extruded on the belt 32 with the width of the extruder 44 wide enough to deposit a layer of plastic which is equal to the desired width of the book cover; that is, the panels 12, 14 and 16.
The thickness of the first layer 18 depends upon the rate at which the material is extruded from the extruder 44.
Beyond the extruder 44 and in the direction in which the belt 32 is travelling, there is a second extruder 48 which applies the second layer of plastic material in the form of independent strips such as the strips 20 and 21 of FIG. 1 or the strips 20', 22' and 24' of FIG. 1A. These strips of the second layer are continuous in the direction of the length of the belt 32, and are separated from one another by the panel 16 of FIG. 1 if there is to be no stiffening of the backbone panel 16, or by the hinge lines 33 if the backbone panel is to be stiffened as shown in FIG. 1A.
The extrudate from the extruder 44 is still in fluid state, as defined herein, when the extrudate from the second applicator or extruder 48 is applied to the first layer. Thus the extruded materials are in a condition to bond with one another by a fusion bond or what may be considered a welding together of the first and second layers to form a one-piece cover.
Immediately beyond the support 36, the combined layers of plastic material, designated as a web 50, passes through a nip roll pass 51 as a station 52 to enhance bonding of the layers 18, 20 and 22; and this roll pass 51 may be used as a surface decorating station consisting of a roll 56 which may be a chilled metal embossing roll, or more generically a contoured decorating roll which displaces the material on the outside surface of the cover to provide a grained effect or other decorative surface treatment. There is a back-up roll 54, which may be of rubber or similar elastomeric material located below the web 50. In order to provide different surface treatment for different covers, the roll 56 may be part of a turret embosser.
The web 50 travels around a series of cooling rolls 60 known in the industry as "cooling cans".
Beyond the cooling rolls 60 the web passes over idler rolls 62 and then passes around a first roll 70 of a festoon or slack accumulator 72. The beginning of the slack accumulator 72 is shown at the right hand end of FIG. 3A and a continuation of the illustration of the slack accumulator 72 is shown in FIG. 3B. A festoon or slack accumulator has a plurality of rolls 70 and 74 located at the top and bottom of the accumulator and between which the web of material to be accumulated runs in generally parallel paths with respect to one another, first downwardly, then upwardly in succession around other rolls spaced far enough and in sufficient number to accumulate the total amount of slack desired. The lower rolls 74 move upwardly when the web is being withdrawn from the discharge end of the accumulator faster than it is being supplied to the left hand end.
When the web 50 stops beyond the right hand end of the accumulator 72, the lower rolls 54 move downwardly to accumulate the material of the web which is passing to the accumulator as the result of continuous movement of the web with the casting paper 32.
Beyond the slack accumulator 72, the web 50 travels in the direction of the arrow 76 in response to movement of an endless belt feeder 80 which operates intermittently.
The belt feeder 80 advances the web 50 across a guide roll 82 to a severing station 84. In the construction illustrated there is a shear or cut-off knife 86 which operates in conjunction with a shear block 88 to sever the web 50 into separate book covers 10 as the plastic material advances onto a conveyor 90. Any other suitable means for severing the web 50 into separate book covers can be used. As each book cover is cut from the web, the intermittent removable belt 80 advances the web for a distance equal to the desired height of a book cover and the web is then severed to make the next book cover.
FIG. 4 is a sectional view on the line 4--4 of FIG. 3A and shows the casting paper 32 before any plastic has been applied to it. FIG. 5 shows the casting paper 32 with the first layer 18 applied to the paper; FIG. 6 shows the casting paper 32 with both the first layer 18 and the second layers 20 and 22 applied to the casting paper and to each other to form a book cover such as shown in FIG. 1.
FIG. 7 is a diagrammatic showing of a modified apparatus for applying the plastic material to a travelling casting surface. In FIG. 7 an endless belt, indicated by the reference character 32' is substituted for the casting paper. This endless belt can be made of metal or any other desired material with a surface of such a character or so coated as to prevent plastic material from adhering to it. There are rolls 92 and 93 around which the belt 32' reverses its direction of travel and there are a plurality of supporting rolls 94 at different locations along the length of both top and bottom runs of the endless belt 32' for supporting the belt without excessive tension. Any suitable supports can be used.
A first layer of material 18a is applied to the endless belt 32' at a first applicator station 96. A diagrammatic showing of the construction of the applicator station 96 is shown in FIG. 8. The structure illustrated is a reverse roll coater.
The plastic material for the first layer 18a, which may be a plastisol, is supplied from a trough 98. A roller 100 dips into the trough and supplies plastic material to a transfer roller 102. A coating roller 104, which is rotated in the opposite direction to the direction in which the belt 32' travels, picks up plastic material from the transfer roll 102 and coats it on the belt 32'. Reverse roll coaters are well known and no further description of the applicator station 96 is necessary for a complete understanding of this invention. The apparatus shown in FIG. 8 is representative of means for applying a first coating 18a in liquid phase to a casting surfce such as the endless belt 32'.
Beyond the applicator station 96, the endless belt 32, with the first layer of plastic material 18a passes through a gelling oven 106 which is of the proper heat and length, in proportion to the speed of travel of the coated material 18a to gel the plastic material to a soft, semi-solid condition.
With the plastic material 18a in a gelled tacky condition, it travels past a second applicator station 108, the construction of which is illustrated diagrammatically in FIG. 9. This figure shows plastic material for a second layer 22a supplied from a trough 110. A roller 112 dips into the trough 110 and carries liquid from the trough to a transfer roller 114 which in turn contacts with a coating roller 118. This coating roller 118 rotates in the same direction of travel as the gel coat 18a, since the gel coat is not of a consistency to safely withstand the friction of a reverse roll coater.
The second coating 22a applied by the coating roller 118 is controlled by a doctor blade 120 which limits the dimensions of the plastic on the periphery of the coating roll 118, beyond the doctor blade 120, to the depressed areas of the roll 118.
Such coaters are well-known in the art so that no further description is necessary except the means for applying the layers locally.
The coating roll 118 is shown in FIG. 10. It contacts with the transfer roll 114, which is usually made of rubber, but the roll 118 has a face of reduced diameter at the portions which are to be used for coating the underlying layer 18a. For example, the roller 118 has a maximum diameter at one end represented by the circumferential area 122. There is then a depressed area 124, which may be engraved or machined and which extends to another full diameter area 126; and the space between these full diameter areas 122 and 126 holds the plastic material 22a which is to be deposited on the underlying layer 18a.
When the roller 118 receives plastic material from the transfer roll 114, the entire circumference of the roller 118 is coated with plastic material but the doctor blade 120 scrapes off all of the plastic material except that which lies in the depression 124 and in other depressed areas of similar construction which hold the plastic material for providing the second layer 24a for the backbone panel and 20a for the front cover panel.
Beyond the second applicator station 108, the endless belt 32' with its two layers of plastic material forming a web 50' passes through a curing oven 130 which is shown in FIG. 7 as a two-stage oven. Curing ovens are also well-known in the plastic manufacturing art and no detailed description of such an oven is necessary for a complete understanding of this invention.
The web 50' comes from the curing oven 130 in a hot condition and if the outside surface of the book cover is to be decorated by graining or other contour treatment, such treatment may be applied just beyond the curing oven 130 at an embossing station 132 where the web 50' is shown passing over a back-up roll 136 and in contact with the bottommost roll of a turret embosser 134.
Beyond the end of the casting surface provided by the upper run of the endless belt 32', the web 50' passes onto a severing station at which it is cut into book covers of the desired height.
FIG. 11 shows a book cover 10a made on the apparatus shown in FIG. 7. This cover has the inner or first layer 18a to which the second layer strips 20a, 22a and 24a have been applied to stiffen the front, back and backbone panels of the book. The front and back panels are shown in broken lines in the positions they occupy after the cover has been applied to a book and the front and back panels 12a and 14a swing with respect to the backbone panel 24a along hinge lines 32a and 22a.
The preferred embodiment of the invention has been illustrated and described, but changes and modifications can be made and some features can be used in different combinations without departing from the invention as defined in the claims.
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An improved method of making hard and semi-rigid book covers, and the product obtained, provides a multi-layer plastic book with any desired ratio of flexibility to stiffness in the different parts of the cover such as the front and back panels, the hinge lines and the backbone panel that connects the front and back panels. A first layer of plastic is cast or extruded on a casting paper or belt or other supporting surface, and additional plastic material is applied to the first layer over areas that will form the front and back panels, and to the backbone area if the desired cover is one that is to have a stiffened backbone panel. A second layer is applied under conditions that insure a highly effective bonding and freedom from distortion when a curing step is necessary. The operation is continuous and the laminate formed is severed into separate covers as it is delivered from the laminating operation.
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RELATED APPLICATIONS
[0001] This application claims priority on U.S. Provisional Patent Appl. No. 60/383,521 filed Apr. 28, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to needle protection devices, and particularly a safety device for use with an intravenous infusion needle.
[0004] 2. Description of the Related Art
[0005] A device commonly referred to as a “butterfly” or winged intravenous infusion assembly often is used for IV infusions and/or for withdrawing venous blood. This device also may be known as a hemodialysis needle. The device typically includes a needle hub with opposite proximal and distal ends and a passage extending between the ends. The device also includes a needle cannula with a proximal end, a sharply pointed distal end and a lumen extending between the ends. The proximal end of the needle cannula is securely mounted in the hub of the device so that the lumen through the needle cannula communicates with the passage through the hub. The device may further include a length of flexible plastic tubing with opposite proximal and distal ends. The proximal end of the tubing typically is mounted to a fitting, such as a luer fitting. The distal end of the tubing is mounted to the proximal end of the hub. Thus, communication is provided between the lumen of the needle cannula and the fitting at the proximal end of the flexible tubing.
[0006] The device is employed by placing the pointed distal end of the needle cannula in communication with a blood vessel and placing the fitting at the proximal end of the flexible tubing in communication with a container that will be used to infuse a drug into the patient or to collect a specimen of blood from the patient. The needle may remain in communication with the patient for an extended time. Hence, it is common to tape the device to the skin of the patient to prevent a painful shifting of the needle relative to the patient. The needle cannula and the hub are very small. Accordingly, wings are provided to manipulate the needle cannula during insertion into the targeted blood vessel. The wings can be folded into face-to-face engagement with one another and gripped between a thumb and forefinger. Thus, the folded wings function as a handle to facilitate proper alignment of the needle cannula during insertion into the blood vessel. The wings then can be rotated into a substantially co-planar disposition and can be taped into face-to-face engagement with the skin of the patient.
[0007] Accidental sticks with a used needle cannula can transmit blood-borne diseases. Thus, some states mandate protection devices to reduce the risk of accidental sticks with a used needle cannula. A very effective needle protection device for IV infusion needles is marketed by Becton Dickinson and Company under the trademark SAFETY-LOCK™. Another safety needle protection system for IV infusion needles is marketed by Sherwood Medical Company and sold under the trademark ANGEL WING™. These systems require a user to grip the wings with one hand and the shield with the other hand. The hands then are moved relative to one another to retract the needle relative to the shield or to move the shield over the needle. Shielding may not be completed properly if the user forgets to perform the two-handed shielding operation or if the exigencies of the medical situation prevent the user from performing the two-handed shielding operation. Additionally, a potential exists that the user will not perform the manual shielding operation properly or completely. Hence, the used needle could be re-exposed prior to being discarded.
[0008] In view of the above, it is an object of the subject invention to provide a needle assembly that permits one-handed shielding of an IV infusion needle.
[0009] It is another object of the subject invention to provide an IV infusion needle assembly that permits shielding to be effected automatically as part of the process of removing the used needle cannula from the patient.
SUMMARY OF THE INVENTION
[0010] The subject invention relates to a medical device, such as an IV infusion set or blood collection set. For simplicity, the device will be referred to herein as an IV infusion set. The IV infusion set includes a needle assembly with a needle hub that has a proximal end, a distal end and a passage extending between the ends. External portions of the hub are provided with a guide. The guide may be a projection that extends in a direction transverse to the passage through the hub, and preferably is formed near the distal end of the hub. The hub may further include a generally cylindrical spring recess extending into the distal end of the hub at a location spaced outwardly from the passage and spaced inwardly from the outer surface of the hub. The needle assembly further includes a needle cannula having a proximal end, a sharply pointed distal end and a lumen extending between the ends. The proximal end of the needle cannula is mounted in the passage of the hub, and the pointed distal end of the needle cannula projects distally beyond the hub.
[0011] The IV infusion set may further include a length of flexible plastic tubing that has a proximal end, a distal end, and a passage extending between the ends. The proximal end of the flexible plastic tubing may be mounted securely to a fitting, such as a female luer fitting. The distal end of the flexible plastic tubing may be mounted to the proximal end of the hub. Thus, the lumen through the needle cannula communicates with the fitting at the proximal end of the flexible plastic tubing.
[0012] The needle assembly further includes first and second wings. The first wing includes a generally planar panel and a center sleeve that is mounted over the hub for both rotational movement and axial sliding movement. The center sleeve has opposite proximal and distal ends and a longitudinal slot extending continuously between the ends. The slot may extend completely through the wall of the sleeve to define a split tube. However, the slot also can be formed only in the inner circumferential surface of the sleeve, and hence may be more in the nature of a groove. The slot defines a circumferential dimension or width that is equal to or slightly greater than the circumferential dimension of the projection on the hub. Thus, the projection on the hub can slide longitudinally through the slot on the center sleeve when the slot of the center sleeve is aligned rotationally with the projection on the hub. However, the center sleeve and the hub are fixed longitudinally relative to one another when the slot in the center sleeve is rotationally offset from the projection on the hub.
[0013] The second wing includes proximal and distal components that are assembled to one another and securely connected after assembly. The proximal component of the second wing includes a generally planar proximal panel and a proximal sleeve that is telescoped over proximal portions of the hub and over distal portions of the flexible tubing. The proximal sleeve is dimensioned and configured for rotational movement about the hub and for longitudinal movement relative to the hub. The proximal sleeve may further include a longitudinally extending slot with a circumferential dimension or width that exceeds circumferential dimension or width of the projection on the hub. The slot in the proximal sleeve may extend completely through the wall of the sleeve in a radial direction or may be a groove in the inner circumferential surface of the sleeve. However, the slot in the proximal sleeve preferably extends only from the distal end of the proximal mounting sleeve to a location between the proximal and distal ends thereof. The length of the slot in the proximal sleeve is equal to or greater than the axial length of the projection on the hub.
[0014] The distal component of the second wing includes a distal panel and a distal sleeve. The distal panel is dimensioned and configured to mate with the proximal panel. The distal sleeve is dimensioned to mount over the distal end of the hub and over portions of the needle cannula. The distal sleeve further includes a longitudinally extending slot that is wider than the projection of the hub. The slot in the distal sleeve may extend completely through the wall of the sleeve or may be a groove in the inner circumferential surface of the sleeve. The slot in the distal sleeve extends from the proximal end of the distal sleeve to a location between the proximal and distal ends, and has an axial length that exceeds the axial length of the projection on the hub.
[0015] The second wing is assembled such that the proximal and distal sleeves are disposed respectively at the proximal and distal ends of the center sleeve of the first wing. Additionally, the slots in the proximal and distal sleeves align with one another and can both be placed in alignment with the slot of the center sleeve by appropriate rotation of the first and/or second wings relative to one another.
[0016] The needle assembly may further include a spring disposed between the hub and at least one of the sleeves. The spring is operative to bias the hub proximally relative to the wings.
[0017] The wings of the needle assembly initially may be in a substantially coplanar disposition with the hub and needle cannula advanced into an extreme distal position relative to the wings. In this position, the projection of the hub is disposed in the slot in the distal sleeve and the spring is in a biased condition. The slot in the center sleeve is offset rotationally from the slot in the distal sleeve. Hence, the projection is prevented from moving through the slot in the center sleeve, and the needle cannula is retained in a position projecting distally beyond the wings.
[0018] The needle assembly of the IV infusion set may be used by rotating the wings upwardly and toward one another so that the wings may function as a convenient handle to be gripped between a thumb and forefinger. This rotational movement of the wings toward one another may rotationally displace the slot in the center sleeve further from the slot in the distal sleeve. Hence, the projection of the hub remains trapped distally of the center sleeve and the needle cannula remains projected distally beyond the wings. The needle cannula then is guided into a targeted blood vessel of a patient. The wings then may be rotated back into their coplanar disposition and may be taped in substantially face-to-face engagement with the skin of the patient.
[0019] Upon completion of the medical procedure, the needle cannula is withdrawn from the patient and the wings are rotated down and toward one another. This rotational movement of the first and second wings down and toward one another moves the slot of the center sleeve into alignment with the projection on the hub. As a result, the spring biases the hub proximally and causes the projection of the hub to move proximally through the slot of the center sleeve and into the slot of the proximal sleeve. This proximal movement of the hub by the spring causes the needle cannula to be retracted safely within the sleeves of the first and second wings. The spring maintains its biasing force to keep the needle cannula in the safely shielded position. Additionally, further downward rotation of the wings may move the slot of the center sleeve beyond the projection of the hub. Thus, the center sleeve retains the projection in the slot of the proximal sleeve and holds the needle cannula in the shielded position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is an exploded perspective view of an IV infusion set in accordance with the subject invention.
[0021] [0021]FIG. 2 is an exploded perspective view of the wings as seen from the front.
[0022] [0022]FIG. 3 is an exploded perspective view of the wings as seen from the rear.
[0023] [0023]FIG. 4 is a perspective view of the needle assembly and tubing in an assembled condition and with the needle cannula projecting in a ready-to-use position.
[0024] [0024]FIG. 5 is a top plan view of the needle assembly shown in FIG. 4.
[0025] [0025]FIG. 6 is a cross-sectional view taken along line 6 - 6 in FIG. 5.
[0026] [0026]FIG. 7 is a perspective view showing movement of the wings toward one another after the IV infusion set.
[0027] [0027]FIG. 8 is a perspective view similar to FIG. 7, but showing the wings rotated into a to generate shielding of the needle cannula.
[0028] [0028]FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 8.
[0029] [0029]FIG. 10 is a perspective view similar to FIG. 8, but showing the needle cannula in a shielded condition.
[0030] [0030]FIG. 11 is a cross-sectional view taken along line 11 - 11 of FIG. 10.
[0031] [0031]FIG. 12 is a perspective view similar to FIG. 10, but showing the needle cannula in the shielded position.
[0032] [0032]FIG. 13 is a cross-sectional view taken along line 13 - 13 in FIG. 12.
DETAILED DESCRIPTION
[0033] An IV infusion set or blood collection set in accordance with the subject invention is identified generally by the numeral 10 in FIGS. 1, 10 and 12 , and for simplicity will be referred to herein as an IV infusion set. IV infusion set 10 includes a needle assembly 12 , a length of flexible plastic tubing 14 and a fitting 16 . Flexible tubing 14 includes a proximal end 18 and a distal end 20 . Proximal end 18 of flexible plastic tubing 14 is secured to fitting 16 . As illustrated herein, fitting 16 is a female luer fitting that communicates with the passage through tubing 14 . However, other fittings be employed, such as a non-patient needle assembly or a luer-activated device port.
[0034] Needle assembly 12 includes a hub 22 that is formed unitarily from a transparent plastic material, such as polypropylene. Hub 22 includes a proximal end 24 , a distal end 26 and a passage 28 extending between the ends. Distal end 20 of tubing 14 is mounted securely to proximal end 24 of hub 22 so that passage 28 through hub 22 communicates with the passage through tubing 14 and with fitting 16 . A projection 30 projects unitarily out from outer circumferential surface of hub 22 substantially adjacent distal end 26 thereof. Projection 30 defines a circumferential dimension or width “a” and a length “b” as shown in FIG. 1. Distal end 26 of hub 22 is characterized further by a generally cylindrical spring recess 32 that is spaced outwardly from passage 28 and inwardly from projection 30 , as shown in FIG. 6.
[0035] Needle assembly 12 also includes a coil spring 34 with a proximal end 36 and a distal end 38 . Proximal end 36 of spring 34 is telescoped into spring recess 32 of hub 22 . Spring 34 is dimensioned so that distal end 38 of spring 34 projects distally beyond hub 22 in an unbiased condition of spring 34 when proximal end 36 of spring 34 is mounted against the proximal end of spring recess 32 .
[0036] Needle assembly 12 further includes a cannula 40 having a proximal end 42 , a pointed distal end 44 and a lumen 46 extending between the ends. Proximal end 42 of cannula 40 is mounted securely in passage 28 of hub 22 so that pointed distal end 44 of cannula 40 projects distally beyond hub 22 . As a result, lumen 46 of cannula 40 communicates with passage 28 of hub 22 , with the passage through tubing 14 and with fitting 16 .
[0037] Needle assembly 12 further includes first and second wings 48 and 50 , as shown most clearly in FIG. 4. First wing 48 includes a panel 52 and a generally cylindrical center sleeve 54 . Center sleeve 54 includes a proximal end 56 , a distal end 58 and a slot 60 extending continuously between ends 56 and 58 . Slot 60 is symmetrical with a diametric plane of center sleeve 54 that is coplanar with or parallel with panel 52 . Slot 60 defines a width “c” that exceeds the width “a” of projection 30 . Additionally, center sleeve 54 has an axial passage 61 with an inside diameter that exceeds the outside diameter of hub 22 . Thus, center sleeve 54 can be telescoped axially over hub 22 by aligning slot 60 of center sleeve 54 with projection 30 . Wing 48 can be rotated relative to hub 22 when center sleeve 54 is displaced axially from projection 30 .
[0038] Center sleeve 54 preferably is substantially rigid to ensure secure mounting over hub 22 and efficient rotational and axial movement relative to hub 22 . However, other portions of first wing 48 need not be rigid, and particularly center portions of panel 52 and lower surface regions of panel 52 conveniently are formed from a less rigid material. Thus, first wing 48 preferably is formed by a co-molding process where at least center sleeve 54 is formed from a rigid relatively stiff material and at least portions of panel 52 are formed from an elastomeric material. This co-molding may be achieved by initially forming center sleeve 54 and then over-molding at least portions of panel 52 over a connecting portion of center sleeve 54 . Center sleeve 54 may be formed from polypropylene, whereas at least portions of panel 52 are formed from a thermoplastic elastomer, such as polyolefin, santoprene or soft PVC. Additionally, center sleeve 54 preferably is formed from a transparent plastic material to provide a clear indication of flashback as explained further herein.
[0039] Second wing 50 is formed from a proximal wing component 62 and a distal wing component 64 that are fused, sonically welded or adhered to one another. Proximal wing component 62 includes a proximal panel 66 and a proximal sleeve 68 . Proximal sleeve 68 is formed from a rigid plastic material, such as polypropylene. Proximal panel 66 preferably is co-molded with proximal sleeve 68 and preferably is formed from a thermoplastic elastomer, as explained with respect to first wing 48 . Proximal sleeve 68 is generally tubular and includes a proximal end 70 , a distal end 72 and a cylindrical passage 74 extending between the ends. Passage 74 defines an inside diameter substantially equal to the inside diameter of passage 61 through center sleeve 54 . Proximal sleeve 68 is characterized by a slot 76 that extends from distal end 72 of proximal sleeve 68 to a location between proximal and distal ends 70 and 72 of proximal sleeve 68 . Slot 76 is symmetrical with a diametric plane of proximal sleeve 68 that is aligned substantially orthogonal to proximal panel 66 . Slot 76 of proximal sleeve 68 has a circumferential dimension or width slightly greater than width “a” of projection 30 of hub 22 and a length slightly greater than length “b” of projection 30 .
[0040] Distal wing component 64 includes a distal panel 78 and a distal sleeve 80 . The distal wing component 64 is formed similar to proximal wing component 62 , with distal sleeve 80 being formed from a substantially rigid material and at least portions of distal panel 78 being formed from a thermoplastic elastomer. Distal sleeve 80 includes a proximal end 82 , a distal end 84 and a passage 86 extending between the ends. Portions of passage 86 adjacent proximal end 82 define an inside diameter slightly greater than the outside diameter of hub 22 . However, portions of passage 86 adjacent distal end 84 define a diameter much smaller than the outside diameter of hub 22 and slightly greater than the diameter of cannula 40 . Distal sleeve 80 is characterized by a slot 88 extending from proximal end 82 partway toward distal end 84 . Slot 82 is symmetrical about a plane aligned orthogonal to distal panel 64 . Additionally, slot 82 defines a width slightly greater than the width “a” of projection 30 on hub 22 and a length slightly greater than length “b” of projection 30 .
[0041] IV infusion set 10 may be assembled by adhering or fusing distal end 20 of tubing 14 to proximal end 24 of hub 22 . Additionally, proximal end 42 of cannula 40 is adhered, fused or otherwise secured in passage 28 through hub 22 . The affixation of cannula 40 to hub 22 is carried out so that the bevel at distal end 44 of cannula 40 and projection 30 of hub 22 are symmetrical about a common plane and face the same radial direction. Assembly proceeds by telescoping spring 34 over cannula 40 and inserting proximal end 36 of spring 34 into spring recess 32 of hub 22 . Thus, distal end 38 of unbiased spring 34 projects distally beyond spring recess 32 .
[0042] Center sleeve 54 of first wing 48 then is telescoped in a proximal-to-distal direction over tubing 14 and over proximal end 24 of hub 22 . This mounting is carried out with slot 62 rotationally offset from projection 30 . Hence, the proximal-to-distal movement of center sleeve 54 will terminate when distal end 56 of center sleeve 54 abuts projection 30 . Proximal wing component 62 then is telescoped over tubing 14 and over proximal end 24 of hub 20 . The proximal-to-distal movement of proximal wing component 14 terminates when distal end 72 of proximal sleeve 68 abuts proximal end 58 of center sleeve 54 .
[0043] Assembly proceeds by telescoping distal wing component 64 in a distal-to-proximal direction over cannula 40 and onto distal end 26 of hub 22 . Distal wing component 64 is rotationally aligned so that projection 30 of hub 22 nests into slot 88 of distal sleeve 80 . Proximal wing component 62 then is rotated relative to distal wing component 64 so that proximal panel 66 is coplanar with distal panel 78 . Proximal and distal panels 66 and 78 are provided with mating pins and apertures to facilitate their alignment and positioning. In their aligned position, slot 82 of distal sleeve 80 aligns with slot 76 of proximal sleeve 68 . Proximal and distal wing panels 66 and 78 then are fused together in a substantially coplanar disposition with slots 76 and 88 permanently aligned with one another. In this connected condition, spring 34 is compressed axially and hence maintains stored energy. Fitting 16 then is secured to proximal end 18 of tubing 14 . Assembly may be completed by mounting a packaging cover (not shown) over cannula 40 and maintaining the packaging cover releasably in position by frictional engagement with distal sleeve 80 or by appropriate use of a tamper evident tape.
[0044] Panel 52 of first wing 48 initially is disposed in substantially coplanar relationship to panels 66 , 78 of second wing 50 . In this position, slot 60 of center sleeve 54 is approximately 90° offset from projection 30 on hub 22 and from slots 76 and 88 on proximal and distal sleeves 68 and 80 of second wing 50 . Hence, projection 30 effectively is trapped between distal end 56 of center sleeve 54 and the distal end of distal sleeve 80 . Accordingly, distal end 44 of cannula 40 projects distally beyond distal sleeve 80 .
[0045] IV infusion set 10 may be used by connecting fitting 16 to an appropriate container that has a fluid that will be infused into a patient or a container for receiving a fluid specimen to be drawn from the patient. Panel 52 of first wing 48 and panel 66 , 78 of second wing 50 then are rotated upwardly toward one another and into substantially face-to-face relationship. This upward rotation of first and second wings 48 and 50 causes slot 60 of center sleeve 54 to rotate into a position displaced approximately 180° from projection 30 of hub 22 . Hence, projection 30 remains trapped in slot 88 of distal sleeve 80 . The medical practitioner then removes the packaging cover from cannula 40 and guides pointed distal end 44 of cannula 40 into a targeted blood vessel. The disposition of needle cannula 40 ensures that the bevel at distal end 44 faces up for convenient guiding into the targeted blood vessel. Access to the blood vessel can be confirmed by the flashback evident in passage 28 as seen through the transparent plastic of hub 22 and of center sleeve 54 . The medical practitioner then may rotate wings 48 and 50 away from one another so that panels 52 , 66 and 78 lie in substantially face-to-face engagement with the skin of the patient. The panels may be taped in this mounted position.
[0046] Upon completion of the medical procedure, the user withdraws cannula 40 from the patient and urges panel 52 of first wing 48 and panel 66 , 78 of second wing 50 downwardly and toward one another. As the wing panels 52 and 66 , 78 approach perpendicular alignment with one another, slot 60 of center sleeve 54 moves into alignment with projection 30 of hub 22 . As a result, stored energy in spring 34 will urge hub 22 proximally relative to wings 48 and 50 and through slot 60 of center sleeve 54 . Thus, distal end 44 of cannula 40 will retract into distal sleeve 80 of second wing 50 . Once projection 30 enters slot 76 of proximal sleeve 68 , slot 60 will permit further downward rotation of wings 48 and 50 toward one another. Thus, slot 60 will be displaced rotationally from projection 30 , and center sleeve 54 will hold projection 30 in slot 76 of proximal sleeve. IV infusion assembly 10 then may be discarded in a sharps receptacle with cannula 40 safely retracted.
[0047] Although not shown, slot 76 in proximal sleeve 68 may be formed with one or more locking detents. The locking detents may include a distal inclined face and a proximal locking face. Spring 34 will guide projection 30 over the inclined distal face of the locking detent. However, projection 30 then will be trapped behind the proximal locking face of the locking detent. Alternatively, spring fingers or detents may be formed on wings 48 and 50 . The spring fingers or detents may be disposed and configured to prevent wings 48 and 50 from returning to a position where cannula 40 can be re-exposed.
[0048] As an alternative to the embodiment described and illustrated above, slot 60 of center sleeve 54 may be disposed to align with projection 30 when first panel 52 is substantially coplanar with second panel 66 , 78 . With this embodiment, spring 34 must be selected to exert forces that are less than frictional forces between cannula 40 and the tissue of the patient. This embodiment is employed substantially as described above by initially holding wings 48 and 50 in face-to-face engagement with one another for insertion of cannula 40 into the patient. Wings 48 and 50 then will be rotated away from one another and into a substantially coplanar disposition adjacent the skin of the patient. This alignment of wings 48 and 50 will dispose slot 60 in a rotational position aligned with projection 30 . However, the frictional forces on cannula 40 will hold cannula 40 and hub 22 in at least a partly extended position. The frictional forces on cannula 40 will gradually reduce as cannula 40 is being withdrawn from the patient. As a result, spring 34 will exert sufficient forces to propel hub 22 and cannula 40 proximally and into a position where cannula 40 is safely shielded.
[0049] The preceding embodiment relates to automatic shielding initiated merely by an appropriate rotational alignment of wings 48 and 50 and the driving force of spring 34 . However, a manually shieldable spring-assisted version of the invention can be provided merely by removing spring 34 and/or extending projection 30 sufficiently to project through the slots of the sleeves of the wings. Thus, shielding can be effected by rotating the wings into a position where the slots align with one another and then manually moving the projection in a proximal direction to effect shielding.
[0050] The preceding embodiments show the slots 60 , 76 and 88 defining widths that are substantially equal to one another and slightly greater than the width “a” of projection 30 . However, the slots 60 , 76 and 88 need not be of equal widths. For example, slot 76 of proximal sleeve 68 may be wider than slot 88 of distal sleeve 80 to facilitate entry of projection 30 into slot 76 . Additionally, slot 60 of center sleeve 54 may be significantly wider than slot 88 of distal sleeve to increase the range of angular positions at which shielding will commence. Thus, shielding will commence at any of a range of angular orientations, and not merely at a single rotational orientation of wings 48 and 50 . These and other variations will be apparent to a person skilled in this art after having read the subject disclosure.
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A shieldable winged needle assembly includes a hub and a cannula projecting distally beyond the hub. A spring is telescoped over the cannula and engages with or into distal portions of the hub. A hub guide projects radially out from the hub. A first wing includes a center sleeve rotationally mounted on the hub and axially movable along the hub when a slot formed in the center sleeve aligns with the hub guide. A second wing has proximal and distal sleeves mounted at opposite ends of the center sleeve. The proximal and distal sleeves each are rotationally mounted relative to the hub and each include slots that enable sliding movement of the hub guide when the slots of the second wing align with the slot of the first wing. The spring propels the cannula and hub into a shielding position when the slots of the wings are rotated into alignment with one another.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a divisional application and claims priority to U.S. patent application Ser. No. 12/343,193 filed Dec. 23, 2008, which claims priority to U.S. patent application Ser. No. 11/285,224 filed on Nov. 22, 2005, which claims priority to U.S. Provisional Patent Application No. 60/630,378 filed on Nov. 23, 2004; U.S. Provisional Patent Application No. 60/656,482 filed on Feb. 24, 2005; and U.S. Provisional Patent Application No. 60/663,218 filed on Mar. 18, 2005 and these applications are incorporated herein by reference in their entirety.
[0002] This work was supported by the National Science Foundation through Grant Number DBI-0233971, with additional support from Grant Number DMR-0451589.
FIELD OF THE INVENTION
[0003] The present invention relates generally to the creation and use of holographic optical traps. More particularly, the present invention relates to the optimization of three-dimensional configurations of holographic optical traps, to the creation of multiple state thermal ratchets for media locomotion and manipulation, and to the creation and use of potential energy well/peak landscapes for fractionation and sorting functionalities.
BACKGROUND OF THE INVENTION
[0004] A single laser beam brought to a focus with a strongly converging lens forms a type of optical trap widely known as an optical tweezer. Multiple beams of light passing simultaneously through the lens' input pupil yield multiple optical tweezers, each at a location determined by its beam's angle of incidence and degree of collimation at the input pupil. The trap-forming laser beams form an interference pattern as they pass through the input pupil, whose amplitude and phase corrugations characterize the downstream trapping pattern. Imposing the same modulations on a single incident beam at the input pupil would yield the same pattern of traps, but without the need to create and direct a number of independent input beams. Such wavefront modification can be performed by a type of diffractive optical element (DOE) commonly known as a hologram.
[0005] Holographic optical trapping (HOT) uses methods of computer-generated holography (CGH) to project arbitrary configurations of optical traps, with manifold applications in the physical and biological sciences, as well as in industry. This flexible approach to manipulate and transform mesoscopic matter has been used to assemble two- and three-dimensional structures, to sort objects ranging in size from nanoclusters to living cells, and to create all-optical microfluidic pumps and mixers.
SUMMARY OF THE INVENTION
[0006] The present invention involves refinements of the basic HOT technique that help to optimize the traps' performance, as well as a suite of statistically optimal analytical tools that are useful for rapidly characterizing the traps' performance. A number of modifications to the conventional HOT optical train minimize defects due to limitations of practical implementations. A direct search algorithm for HOT DOE computation can be used that is both faster and more accurate than commonly used iterative refinement algorithms. A method for rapidly characterizing each trap in a holographic array is also described. The optimal statistical methods on which this characterization technique is based lends itself naturally to digital video analysis of optically trapped spheres and can be exploited for real-time optimization.
[0007] In accordance with another aspect of the present invention the holographic traps are used to implement thermal ratchets in one, two, and three dimensions. A radial three-state ratchet is illustrated where particles of different size accumulate at different radial positions. A radial two-state ratchet may be achieved as a two-dimensional extension of the methods described above as well.
[0008] In accordance with yet another aspect of the present invention, the ratchet is spherical. This is an extension of the two-dimensional radial ratchet to three dimensions where spherical arrays of optical traps or other forms of potential energy wells sort and accumulate particles or objects of different sizes at different spherical positions. This may take the form of a two-state or three-state ratchet.
[0009] The two-state and three-state ratchets provide for a number of methods and apparatus for locomotion. These methods of locomotion are achieved broadly through the use of multiple potential energy wells. The potential energy wells may be achieved through a variety of methods. In the description above the method used is arrays of holographic optical traps. Additional methods include use of other photonic methods to implement two-state and three-state ratchets based on the various available methods of light steering. These also include chemical, biological, electrical, or other various mechanical methods involving two-state or three-state ratchets in which an aspect of the present invention may include a movable lever or arm. This movable lever or arm may be user controllable so as to enable a number of devices or mechanisms which sort or pump or provide various forms of locomotion for particles or objects.
[0010] In accordance with yet another aspect of the present invention is a polymer walker. This may be created through a walker shaped more or less like a capital Greek letter lambda out of a polymeric material such as a gel that responds to an external stimulus by changing the opening angle between its legs. Examples of such active materials include Tanaka gels, which can be functionalized to respond to changes in salt concentration, electrolyte valence, pH, glucose concentration, temperature, and even light. These gels respond to such stimuli by swelling or shrinking. This can be used to achieve the kind of motion described above for a two-state ratchet. The rates of opening and closing can be set by chemical kinetics in such a system. The legs' affinity for specific places on a substrate can be determined by chemical, biochemical, or physical patterning of a suitable substrate, with the ends of the legs appropriately functionalized to respond to those patterns.
[0011] In accordance with yet another aspect of the present invention two state and three-state ratchets are used to build micromachines which may consist of mesoscopic motors based on synthetic macromolecules or microelectromechanical systems (MEMS).
[0012] These ratchet mechanisms may be used in the fabrication of devices or apparatus which pump, sort, shuttle or otherwise transport or manipulate particles or cargo in a variety of patterns with application to a range of fields including but not limited to sorting systems, transport systems, shuttle systems, sensor systems, reconnaissance systems, delivery systems, fabrication systems, purification systems, filtration systems, chemical processing, medical diagnostics and medical therapeutics.
[0013] In accordance with yet another aspect of the present invention, potential energy wells may be created using any of various methods of creating potential energy landscapes including without limitation electrophoresis, dielectrophoresis, traveling wave dielectrophoresis, programmable dielectrophoresis, CMOS dieletrophoresis, optically induced eletrophoretic methods, acoustic traps, and hydrodynamic flows as well as other various such methods. These methods may be programmable. These methods may further be programmed or constructed and controlled so as to create potential energy landscapes and potential energy wells that implement the various ratchet and fractionation constructs as presented above.
[0014] In accordance with yet another aspect of the present invention, potential energy landscapes may be created from a class of sources including optical intensity fields, optically guided dielectrophoresis, and any other technique including surface relief on a textured surface. Furthermore the present invention may be implemented as an optically guided dielectrophoresis implementation of optical fractionation, (which may be referred to as optically guided dielectrophoretic fractionation) as well as an optically guided dielectrophoretic implementation of optical ratchets (which may be referred to as optically guided dielectrophoretic ratchets).
[0015] These and other objects, advantages and features of the invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1( a ) is a simplified schematic of a conventional HOT implementation; FIG. 1( b ) shows a modification to the conventional HOT design of FIG. 1( a ) that minimizes the central spot's influence and effectively eliminates ghost traps by having the source laser beam converge as it passes through the DOE; and FIG. 1( c ) shows another modification to the conventional HOT design where a beam block is placed in the intermediate focal plane within the relay optics to spatially filter the undiffracted portion of the beam;
[0017] FIG. 2 shows a three-dimensional multifunctional holographic optical trap array created with a single phase-only DOE computed with the direct search algorithm, wherein the top DOE phase pattern includes white regions corresponding to a phase shift of 2π radians and black regions corresponding to 0, and wherein the bottom projected optical trap array is shown at z=−10 μm, 0 μm and +10 μm from the focal plane of a 100×, NA 1.4 objective lens, with the traps being spaced by 1.2 μm in the plane, and the 12 traps in the middle plane consisting of l=8 optical vortices;
[0018] FIG. 3 is a plot showing the performance metrics for the hologram of FIG. 2 as a function of the number of accepted single-pixel changes, where data includes the DOE's overall diffreaction efficiency as defined by Eq. (14), the projected patterns RMS error from Eq. (15), and its uniformity, 1−u, where u is defined in Eq. (16); and
[0019] FIG. 4( a ) is a design for 119 identical optical traps in a two-dimensional quasiperiodic array; FIG. 4( b ) shows the trapping pattern projected without optimizations using the adaptive-additive algorithm; FIG. 4( c ) shows the trapping pattern projected with optimized optics and an adaptively corrected direct search algorithm; and FIG. 4( d ) shows a bright-field image of colloidal silica spheres 1.58 μm in diameter dispersed in water and organized in the optical trap array, where the scale bar indicates 10 μm.
[0020] FIG. 5( a ) is a schematic representation of a holographic thermal ratchet embodiment; FIG. 5( b ) shows focused light from a typical HOT pattern; FIG. 5( c ) shows an aqueous dispersion of colloidal trapped silica spheres interacting with the HOTs; and FIG. 5( d ) shows the ratchet effect;
[0021] FIG. 6 shows flux induced by a two-state holographic optical ratchet;
[0022] FIG. 7( a ) shows stochastic resonance in the two-state optical thermal ratchet for τ/L=0.125; and FIG. 7( b ) shows dependence on well depth for the optimal angle rate τ/π=0.193 and duty cycle;
[0023] FIG. 8( a ) shows flux reversed in a symmetric three-state optical thermal ratchet as a function of cycle period fixed manifold separation; and FIG. 8( b ) shows this flux reversal as a function of inter-manifold separation L for fixed cycle period T;
[0024] FIG. 9 shows calculated ratchet-induced drift velocity as a function of cycle period for various inter-manifold separation L from a deterministic limit, L=6.55 to the stochastic limit L=130;
[0025] FIG. 10( a ) shows fractionation in a radial optical thermal ratchet with patterns of concentric circular manifolds with L=4.7 μm; FIG. 10( b ) is a mixture of large and small particles interacting with a fixed trapping pattern; FIG. 10( c ) is small particles being collected and large ones excluded at L=6.9 μm and t=4.5 sec.; and FIG. 10( d ) shows large particles concentrated at L=5.3 μm and t=4.5 sec. (the scale bar is 10 μm).
[0026] FIG. 11( a )- 11 ( d ) shows a four-part sequence of spatially symmetric three-state ratchet potentials;
[0027] FIG. 12( a ) shows cross-over from deterministic optical peristalsis at L=6.5σ to thermal ratchet behavior with flux reversed at L-130 for a three-state cycle of Gaussian well potentials at βV 0 =8.5, σ=0.53 μm and D=0.33 μm 2 /sec.; FIG. 12( b ) is for evenly spaced values of L with the image of 20×5 array of holographic optical traps at L 0 =6.7 μm; FIG. 12( c ) is an image of colloidal silica spheres 1.53 μm in diameter interacting with the array; FIG. 12( d ) shows rate dependence of the induced drift velocity for fixed inter-trap separation, L 0 ; FIG. 12( e ) shows separation dependence for fixed inter-state delay, T=2 sec.;
[0028] FIG. 13 shows one complete cycle of a spatially symmetric two-state ratchet potential comprised of discrete potential wells;
[0029] FIG. 14( a ) shows a displacement function ƒ(t); and FIG. 14( b ) shows an equivalent-ratchet driving force;
[0030] FIG. 15 shows steady-state drift velocity as a function of the relative dwell time, T 2 /T 1 , for BV 0 =3.04, L=5.2 μm, σ=0.80 μm and various values of T/t (optimized at T/τ=0.193);
[0031] FIG. 16( a ) shows an image of 5×20 array of holographic optical traps at L=5.2 μm; FIG. 16( b ) shows a video micrograph of colloidal silica spheres 1.53 μm in diameter trapped in the middle row of the array at the start of an experimental run; FIGS. 16( c ) and 16 ( d ) show time evolution of the measured probability density for finding particles at T 2 =0.8 sec. and T 2 =8.6 sec., respectively, with T 1 fixed at 3 sec.; FIG. 16( e ) shows time evolution of the particles' mean position calculated from the distribution functions in FIGS. 16( c ) and 16 ( d ) (the slopes of linear fits provide estimates for the induced drift velocity, which can be compared with displacements calculated with Eq. (89) for βV 0 =2.5, and σ=0.65); and FIG. 16( f ) shows measured drift speed as a function of relative dwell time T 2 /T 1 , compared with predictions of Eq. (88); and
[0032] FIG. 17 shows a model of a diffusive molecular motor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A. Optimized Holographic Optical Traps
[0033] FIGS. 1( a )- 1 ( c ) show a simplified schematic of a holographic optical tweezer optical train before and after modification. FIG. 1( a ) shows a simplified schematic of a conventional HOT implementation, where a collimated beam of light from a source laser is imprinted with a CGH and thereafter propagates as a superposition of independent beams, each with individually specified wavefront characteristics. These beams are relayed to the input aperture of a high-numerical-aperture lens, typically a microscope objective, which focuses them into optical traps in the objective's focal plane. FIG. 1( a ) shows the CGH being projected by a transmissive DOE. The same principle applies to reflective DOE's with the appropriate modification of the optical train. It should be noted that the same objective lens used to form the optical traps also can be used to create images of trapped objects. The associated illumination and image-forming optics are omitted from FIGS. 1( a )- 1 ( c ) for clarity.
[0034] Practical holograms only diffract a portion of the incident light into intended modes and directions. A portion of the incident beam is not diffracted at all, and the undiffracted portion typically forms an unwanted trap in the middle of the field of view. The undiffracted portion of the beam is depicted with dark shading in FIG. 1( a ). This “central spot” has been removed in previous implementations by spatially filtering the diffracted beam. Practical DOE's also tend to project spurious “ghost” traps into symmetry-dictated positions within the sample. Spatially filtering a large number of ghost traps generally is not practical, particularly in the case of dynamic holographic optical tweezers whose traps move freely in three dimensions. Projecting holographic traps in the off-axis Fresnel geometry, rather than the Fraunhofer geometry, automatically eliminates the central spot. However, this implementation limits the number of traps that can be projected and also does not address the formation of ghost traps.
[0035] FIG. 1( b ) shows one improvement to the basic HOT design that minimizes the central spot's influence and effectively eliminates ghost traps. In FIG. 1( b ), the source laser beam is converging as it passes through the DOE. As a result, the undiffracted central spot focuses upstream of the objective's normal focal plane. The degree of collimation of each diffracted beam, and thus the axial position of the resulting trap, can be adjusted by incorporating wavefront-shaping phase functions into the hologram's design, thereby returning the traps to the focal volume. This expedient allows the central spot to be projected into the coverslip bounding a sample, rather than the sample itself, thereby ensuring that the undiffracted beam lacks both the intensity and the gradients needed to influence a sample's dynamics.
[0036] An additional consequence of the traps' displacement relative to the converging beam's focal point is that ghost traps are projected to the far side of this point and, therefore, out of the sample volume altogether. This constitutes a substantial improvement for processes, such as optical fractionation, which use a precisely specified optical potential energy landscape to continuously sort mesoscopic objects.
[0037] Even though the undiffracted beam may not create an actual trap in this modified optical train, it still can exert radiation pressure on the region of the sample near the center of the field of view. This is a particular issue for large arrays of optical traps that require substantial power in the source beam. The undiffracted portion then can produce a central spot far brighter than any individual trap.
[0038] Illuminating the DOE with a diverging beam further reduces the undiffracted beam's influence by projecting some of its light out of the optical train. In a thick sample, however, this has the deleterious effect of projecting both the weakened central spot and the undiminished ghost traps into the sample.
[0039] These issues can be mitigated by placing a beam block as shown in FIG. 1( c ) in the intermediate focal plane within the relay optics to spatially filter the undiffracted portion of the beam. Because the trap-forming beams come to a focus in a different plane, they are only slightly occluded by the beam block, even if they pass directly along the optical axis. The effect of this occlusion is minimal for conventional optical tweezers and can be compensated by appropriately increasing their relative brightness. Therefore, the effect of an arrangement as described in FIG. 1( c ) is the elimination of the undiffracted beam without substantially degrading the optical traps.
[0040] Holographic optical tweezers' efficacy is determined by the quality of the trap-forming DOE, which in turn reflects the performance of the algorithms used in their computation. Conventional implementations have applied holograms calculated by a simple linear superposition of the input fields. In such situations, the best results are obtained with random relative phases or with variations on the classic Gerchberg-Saxton and Adaptive-Additive algorithms. Despite their general efficacy, these algorithms yield traps whose relative intensities can differ substantially from their design values and typically project a substantial fraction of the input power into ghost traps. These problems can become acute for complicated three-dimensional trapping patterns, particularly when the same hologram also is used as a mode converter to project multifunctional arrays of optical traps.
[0041] A faster and more effective algorithm for HOT DOE calculation based on direct search is generally as follows. The holograms used for holographic optical trapping typically operate only on the phase of the incident beam, and not its amplitude. Such phase-only holograms, also known as kinoforms, are far more efficient than amplitude-modulating holograms, which necessarily divert light away from the beam. Kinoforms also are substantially easier to implement than fully complex holograms. General trapping patterns can be achieved with kinoforms despite the loss of information that might be encoded in amplitude modulations because optical tweezers rely for their operation on intensity gradients and not local phase variations. However, it is necessary to find a pattern of phase shifts in the input plane that encodes the desired intensity pattern in the focal volume.
[0042] According to scalar diffraction theory, the (complex) field E({right arrow over (r)}) in the focal plane of a lens of focal length ƒ is related to the field, u({right arrow over (ρ)})exp(iφ({right arrow over (ρ)})), in its input plane by a Fraunhofer transform,
[0000]
E
(
r
→
)
=
∫
u
(
ρ
→
)
exp
(
ϕ
(
ρ
→
)
)
exp
(
-
k
r
→
·
ρ
→
2
f
)
2
ρ
,
(
1
)
[0000] where u({right arrow over (ρ)}) and φ({right arrow over (ρ)}) are the real-valued amplitude and phase, respectively, of the field at position ({right arrow over (ρ)}) in the input pupil, and k=2 π/λ is the wave number of light of wavelength λ.
[0043] If u ({right arrow over (ρ)}) is the amplitude profile of the input laser beam, then φ({right arrow over (ρ)}) is the kinoform encoding the pattern. Most practical DOEs, including those projected with SLMs, consist of an array {right arrow over (ρ)} j of discrete phase pixels, each of which can impose any of P possible discrete phase shifts φ j ε{0, . . . , φ P−1 }. The field in the focal plane due to such an N-pixel DOE is, therefore,
[0000]
E
(
r
→
)
=
∑
j
=
1
N
u
j
exp
(
ϕ
j
)
T
j
(
r
→
)
,
(
2
)
[0000] where the transfer matrix describing the propagation of light from input plane to output plane is
[0000]
T
j
(
r
→
)
=
exp
(
-
k
r
→
·
ρ
→
j
2
f
)
.
(
3
)
[0044] Unlike more general holograms, the desired field in the output plane of a holographic optical trapping system consists of M discrete bright spots located at {right arrow over (r)} m :
[0000]
E
(
r
→
)
=
∑
m
=
1
M
E
m
(
r
→
)
,
with
(
4
)
E
m
(
r
→
)
=
α
m
δ
(
r
→
-
r
→
m
)
exp
(
ξ
m
)
,
(
5
)
[0000] where α m is the relative amplitude of the m-th trap, normalized by Σ m−1 M |α m | 2 =1 and ξ m is its (arbitrary) phase. Here, δ({right arrow over (r)}) represents the amplitude profile of the focused beam of light in the focal plane, which may be treated heuristically as a two-dimensional Dirac delta function.
The design challenge is to solve Eqs. (2), (3) and (4) for the set of phase shifts ξ m , yielding the desired amplitudes α m at the correct locations {right arrow over (r)} m given u j and T j ({right arrow over (ρ)}).
[0045] The Gerchberg-Saxton algorithm and its generalizations, such as the adaptive-additive algorithm, iteratively solve both the forward transform described by Eqs. (5) and (6), and also its inverse, taking care at each step to converge the calculated amplitudes at the output plane to the design amplitudes and to replace the back-projected amplitudes, u j at the input plane with the laser's actual amplitude profile. Appropriately updating the calculated input and output amplitudes at each cycle can cause the DOE phase φ j , to converge to an approximation to the ideal kinoform, with monotonic convergence possible for some variants. The forward and inverse transforms mapping the input and output planes to each other typically are performed by fast Fourier transform (FFT). Consequently, the output positions {right arrow over (r)} m also are explicitly quantized in units of the Nyquist spatial frequency. The output field is calculated not only at the intended positions of the traps, but also at the spaces between them. This is useful because the iterative algorithm not only maximizes the fraction of the input light diffracted into the desired locations, but also minimizes the intensity of stray light elsewhere.
[0046] FFT-based iterative algorithms have drawbacks for computing three-dimensional arrays of optical tweezers, or mixtures of more general types of traps. To see this, one notes how a beam-splitting DOE can be generalized to include wave front-shaping capabilities.
[0047] A diverging or converging beam at the input aperture comes to a focus and forms a trap downstream or upstream of the focal plane, respectively. Its wave front at the input plane is characterized by the parabolic phase profile
[0000]
ϕ
z
(
ρ
→
,
z
)
=
k
ρ
2
z
f
2
,
(
6
)
[0000] where z is the focal spot's displacement along the optical axis relative to the lens' focal plane. This phase profile can be used to move an optical trap relative to the focal plane even if the input beam is collimated by appropriately augmenting the transfer matrix:
[0000] T j z ({right arrow over ( r )})= T j ({right arrow over ( r )}) K j z ({right arrow over ( r )}), (7)
[0000] where the displacement kernel is
[0000] K j z ({right arrow over ( r )})=exp( iφ z ({right arrow over (ρ)} j ,z )), (8)
[0048] The result, T j z ({right arrow over (r)}), replaces T j ({right arrow over (r)}) as the kernel of Eq. (2).
[0049] Similarly, a conventional TEM beam can be converted into a helical mode by imposing the phase profile
[0000] φ l ({right arrow over (ρ)})= lθ (9)
[0000] where θ is the azimuthal angle around the optical axis and l is an integral winding number known as the topological charge. Such corkscrew-like beams focus to ring-like optical traps known as optical vortices that can exert torques as well as forces. The topology-transforming kernel K j l ({right arrow over (r)})=exp(iφ l ({right arrow over (ρ)} j )) can be composed with the transfer matrix in the same manner as the displacement-inducing {right arrow over (r)} m .
[0050] A variety of comparable phase-based mode transformations are described, each with applications to single-beam optical trapping. All can be implemented by augmenting the transfer matrix with an appropriate transformation kernel. Moreover, different transformation operations can be applied to each beam in a holographic trapping pattern independently, resulting in general three-dimensional configurations of diverse types of optical traps.
[0051] Calculating the phase pattern φ j encoding multifunctional three-dimensional optical trapping patterns requires only a slight elaboration of the algorithms used to solve Eq. (2) for two-dimensional arrays of conventional optical tweezers. The primary requirement is to measure the actual intensity projected by φ j into the m-th trap at its focus. If the associated diffraction-generated beam has a non-trivial wave front, then it need not create a bright spot at its focal point. On the other hand, if it is assumed that φ j creates the required type of beam for the m-th trap through a phase modulation described by the transformation kernel K j,m ({right arrow over (r)}), then applying the inverse operator, K j,m −1 ({right arrow over (r)}) in Eq. (2) would restore the focal spot.
[0052] This principle was first applied to creating three dimensional trap arrays in which separate translation kernels were used to project each desired optical tweezer back to the focal plane as an intermediate step in each iterative refinement cycle. Computing the light projected into each plane of traps in this manner involves a separate Fourier transform for the entire plane. In addition to its computational complexity, this approach also requires accounting for out-of-focus beams propagating through each focal plane, or else suffers from inaccuracies due to failure to account for this light.
[0053] A substantially more efficient approach involves computing the field only at each intended trap location, as
[0000]
E
m
(
r
→
m
)
=
∑
j
=
1
N
K
j
,
m
-
1
(
r
→
m
)
T
j
(
r
→
m
)
exp
(
-
ϕ
j
)
,
(
10
)
[0000] and comparing the resulting amplitude α m =|E m | with the design value. Unlike the FFT-based approach, this per-trap algorithm does not directly optimize the field in the inter-trap region. Conversely, there is no need to account for interplane propagation. If the values of α m match the design values, then no light is left over to create ghost traps.
[0054] Iteratively improving the input and output amplitudes by adjusting the DOE phases, φ j , involves back-transforming from each updated E m using the forward transformation kernels, K j,m ({right arrow over (r)} m ) with one projection for each of the M traps. By contrast, the FFT-based approach involves one FFT for each wave front type within each plane and may not converge if multiple wave front types are combined within a given plane.
[0055] The per-trap calculation suffers from a number of shortcomings. The only adjustable parameters in Eqs. (5) and (10) are the relative phases ξ m of the projected traps. These M−1 real-valued parameters must be adjusted to optimize the choice of discrete-valued phase shifts, φ j , subject to the constraint that the amplitude profile u j matches the input laser's. This problem is likely to be underspecified for both small numbers of traps and for highly complex heterogeneous trapping patterns. The result for such cases is likely to be optically inefficient holograms whose projected amplitudes differ from their ideal values.
[0056] Equation (10) suggests an alternative approach for computing DOE functions for discrete HOT patterns. The operator, K j,m −1 ({right arrow over (r)} m )T m ({right arrow over (r)} m ) describes how light in the mode of the m-th trap propagates from position {right arrow over (ρ)} j on the DOE to the trap's projected position {right arrow over (r)} m , in the lens' focal plane. If the DOE's phase φ j were changed at that point, then the superposition of rays composing the field at {right arrow over (r)} m would be affected. Each trap would be affected by this change through its own propagation equation. If the changes led to an overall improvement, then one would be inclined to keep the change, and seek other such improvements. If, instead, the results were less beneficial, φ j would be restored to its former value and the search for other improvements would continue. This is the basis for direct search algorithms, including the extensive category of simulated annealing and genetic algorithms.
[0057] In its most basic form, direct search involves selecting a pixel at random from a trial phase pattern, changing its value to any of the P−1 alternatives, and computing the effect on the projected field. This operation can be performed efficiently by calculating only the changes at the M trap's positions due to the single changed phase pixel, rather than summing over all pixels. The updated trial amplitudes then are compared with their design values and the proposed change is accepted if the overall amplitude error is reduced. The process is repeated until the acceptance rate for proposed changes becomes sufficiently small.
[0058] The key to a successful and efficient direct search for φ j is to select a function that effectively quantifies projection errors. The standard cost function, Σ m−1 M(I m −εI m (D) ) 2 , assesses the mean-squared deviations of the m-th trap's projected intensity I m =|α m | 2 from its design value I m (D) , assuming an overall diffraction efficiency of ε. It requires an accurate estimate for ε and places no emphasis on uniformity in the projected traps' intensities. A conventional alternative,
[0000] C=− I +ƒσ, (11)
[0000] avoids both shortcomings. Here,
[0000]
〈
I
〉
=
1
M
∑
m
=
1
M
I
m
[0000] is the mean intensity at the traps, and
[0000]
σ
=
1
M
∑
m
=
1
M
(
I
m
-
γ
I
m
(
D
)
)
2
(
12
)
[0000] measures the deviation from uniform convergence to the design intensities. Selecting
[0000]
γ
=
∑
m
=
1
M
I
m
I
m
(
D
)
∑
m
=
1
M
(
I
m
(
D
)
)
2
(
13
)
[0000] minimizes the total error and accounts for non-ideal diffraction efficiency. The weighting fraction ƒ sets the relative importance attached to overall diffraction efficiency versus uniformity.
[0059] In the simplest direct search for an optimal phase distribution, any candidate change that reduces C is accepted, and all others are rejected. Selecting pixels to change at random reduces the chances of the search becoming trapped by suboptimal configurations that happen to be highly correlated. The typical number of trials required for practical convergence should scale as N P, the product of the number of phase pixels and the number of possible phase values. In practice, this rough estimate is accurate if P and N are comparatively small. For larger values, however, convergence is attained far more rapidly, often within N trials, even for fairly complex trapping patterns. In this case, the full refinement requires computational resources comparable to the initial superposition and is faster than typical iterative algorithms by an order of magnitude or more.
[0060] FIG. 2 shows a typical application of the direct search algorithm to computing a HOT DOE consisting of 51 traps, including 12 optical vortices of topological charge l=8, arrayed in three planes relative to the focal plane. The 480×480 pixel phase pattern was refined from an initially random superposition of fields in which amplitude variations were simply ignored. The results in FIG. 2 were obtained with a single pass through the array. The resulting traps, shown in the bottom three images, vary from their planned relative intensities by less than 5 percent. This compares favorably with the 50 percent variation typically obtained with the generalized adaptive-additive algorithm. This effect was achieved by setting the optical vortices' brightness to 15 times that of the conventional optical tweezers. This single hologram therefore demonstrates independent control over three-dimensional position, wave front topology, and brightness of all the traps.
[0061] To demonstrate these phenomena more quantitatively, standard figures of merit are augmented with those known in the art. In particular, the DOE's theoretical diffraction efficiency is commonly defined as
[0000]
Q
=
1
M
∑
m
=
1
M
I
m
I
m
(
D
)
,
(
14
)
[0062] and its root-mean-square (RMS) error as
[0000]
e
rms
=
σ
max
(
I
m
)
.
(
15
)
[0063] The resulting pattern's departure from uniformity is usefully gauged as
[0000]
u
=
max
(
I
m
/
I
m
(
D
)
-
min
(
I
m
/
I
m
(
D
)
)
)
max
(
I
m
/
I
m
(
D
)
+
min
(
I
m
/
I
m
(
D
)
)
)
.
(
16
)
[0064] These performance metrics are plotted in FIG. 3 as a function of the number of accepted single-pixel changes. The overall acceptance rate for changes after a single pass through the entire DOE array was better than 16%.
[0065] FIG. 3 demonstrates that the direct search algorithm trades off a small percentage of the overall diffraction efficiency in favor of substantially improved uniformity. This improvement over randomly phased superposition requires little more than twice the computational time and typically can be completed in a time comparable to the refresh interval of a liquid crystal spatial light modulator.
[0066] Two-dimensional phase holograms contain precisely enough information to encode any two-dimensional intensity distribution. A three-dimensional or multi-mode pattern, however, may require both the amplitude and the phase to be specified in the lens' focal plane. In such cases, a two-dimensional phase hologram can provide at best an approximation to the desired distribution of traps. Determining whether or not a single two-dimensional phase hologram can encode a particular trapping pattern is remains an issue. The direct search algorithm presented above may become stuck in local minima of the cost function instead of identifying the best possible phase hologram. In such cases, more sophisticated numerical search algorithms may be necessary.
[0067] The most straightforward elaboration of a direct search is the class of simulated annealing algorithms. Like direct search, simulated annealing repeatedly attempts random changes to randomly selected pixels. Also like direct search, a candidate change is accepted if it would reduce the cost function. The probability P accept for accepting a costly change is set to fall of exponentially in the incremental cost ΔC,
[0000]
P
=
exp
(
-
Δ
C
C
0
)
.
(
17
)
[0068] where C o is a characteristic cost that plays the role of the temperature in the standard Metropolis algorithm. Increasing C o results in an increased acceptance rate of costly changes and a decreased chance of becoming trapped in a local minimum. The improved opportunities for finding the globally optimal solution come at the cost of increased convergence time.
[0069] The tradeoff between exhaustive and efficient searching can be optimized by selecting an appropriate value of C o . However, the optimal choice may be different for each application. Starting C o at a large value that promotes exploration and then reducing it to a lower value that, speeds convergence offers one convenient compromise. Several strategies for varying C o have been proposed and are conventionally recognized.
[0070] Substantially more effective searches may be implemented by attempting to change multiple pixels simultaneously instead of one at a time. Different patterns of multi-pixel changes may be most effective for optimizing trap-forming phase holograms of different types, and the approaches used to identify and improve such patterns generally are known as genetic algorithms. These more sophisticated algorithms may be applicable for designing high-efficiency, high-accuracy DOEs for precision HOT applications.
[0071] At least numerically, direct search algorithms are both faster and better at calculating trap-forming DOEs than iterative refinement algorithms. The real test, however, is in the projected traps' ability to trap particles. A variety of approaches have been developed for gauging the forces exerted by optical traps. The earliest approach involved measuring the hydrodynamic drag required to dislodge a trapped particle, typically by translating the trap through quiescent fluid. This approach has several disadvantages, most notably that it identifies only the minimal escape force in a given direction and not the trap's actual three-dimensional potential energy landscape. Most conventionally-known implementations fail to collect sufficient statistics to account for thermal fluctuations' role in the escape process, and do not account adequately for hydrodynamic coupling to bounding surfaces.
[0072] Much more information can be obtained by measuring a particle's thermally driven motions in the trap's potential well. One approach involves measuring the particle's displacements {right arrow over (r)}(t) from its equilibrium position and computing the probability density P({right arrow over (r)}) as a histogram of these displacements. The result is related to the potential energy well V({right arrow over (r)}) through the Boltzmann distribution
[0000] P ({right arrow over ( r )})=exp(=β V ({right arrow over ( r )})), (18)
[0000] where β −1 =k B T is the thermal energy scale at temperature T. Thermal calibration offers benefits in that no external force has to be applied, and yet the trap can be fully characterized, provided enough data is taken. A complementary approach to thermal calibration involves computing the autocorrelation function of Δ{right arrow over (r)}(t). Both of these approaches require amassing enough data to characterize the trapped particle's least probable displacements, and therefore most of its behavior is oversampled. This does not present a significant issue when data from a single optical trap can be collected at high sampling rates, for example with a quadrant photodiode. Tracking multiple particles in holographic optical traps, however, is most readily accomplished through digital video microscopy, which yields data more slowly by two or three orders of magnitude. Fortunately, an analysis based on optimal statistics provides all the benefits of thermal calibration by rigorously avoiding oversampling.
[0073] In many cases, an optical trap may be modeled as a harmonic potential energy well,
[0000]
V
(
r
→
)
=
3
2
∑
i
=
1
3
κ
i
r
i
2
,
(
19
)
[0000] with a different characteristic curvature K i along each Cartesian axis. This form has been found to accurately describe optical traps' potential energy wells in related studies and has the additional benefit of permitting a one-dimensional mathematical description. Consequently, the subscripts are dropped in the following discussion.
[0074] The behavior of a colloidal particles localized in a viscous fluid by an optical trap is described by the Langevin equation
[0000]
x
.
(
t
)
=
-
x
(
t
)
τ
+
ξ
(
t
)
,
(
20
)
[0000] where the auto correlation time
[0000]
τ
=
γ
κ
(
21
)
[0000] is set by the viscous drag coefficient γ and the curvature of the well, κ, and where ξ(t) describes random thermal forcing with zero mean, ξ(t) =0, and variance
[0000]
〈
ξ
(
t
)
ξ
(
s
)
〉
=
2
k
B
T
γ
δ
(
t
-
s
)
.
(
22
)
[0075] If the particle is at position x 0 x 0 at time t=0, its trajectory at later times is given by
[0000]
x
(
t
)
=
x
0
exp
(
-
t
τ
)
+
∫
0
t
ξ
(
s
)
exp
(
-
t
-
s
τ
)
s
.
(
23
)
[0076] Experimentally, such a trajectory is sampled at discrete times t j =jΔt, so that Eq. (23) may be rewritten as
[0000]
x
j
+
1
=
exp
(
-
t
j
+
1
τ
)
x
0
+
∫
0
t
j
ξ
(
s
)
exp
(
-
t
j
-
s
τ
)
s
+
∫
t
j
t
j
+
1
ξ
(
s
)
exp
(
-
t
j
+
1
-
s
τ
)
s
(
24
)
=
φ
x
j
+
a
j
+
1
,
where
(
25
)
φ
=
exp
(
-
Δ
t
τ
)
(
26
)
[0000] and where α j+1 is a Gaussian random variable with zero mean and variance
[0000]
σ
a
2
=
k
B
T
κ
[
1
-
exp
(
-
2
Δ
t
τ
)
]
.
(
27
)
[0077] Because φ<1, Eq. (25) is an example of an autoregressive process which is readily invertible. In principle, the particle's trajectory {x j } can be analyzed to extract φ and σ a 2 , which, in turn, provide estimates for the trap's stiffness, κ, and the viscous drag coefficient γ.
[0078] In practice, however, the experimentally measured particle positions y j differ from the actual positions x j by random errors b j , which is assumed to be taken from a Gaussian distribution with zero mean and variance σ b 2 . The measurement then is described by the coupled equations
[0000] x j =φx j−1 +a j and
[0000] y j =x j +b j , (28)
[0000] where b j is independent of a j . Estimates can still be extracted for φ and as from a set of measurements σ a 2 by first constructing the joint probability
[0000]
p
(
{
x
i
}
,
{
y
i
}
|
φ
,
σ
a
2
,
σ
b
2
)
=
∏
j
=
2
N
[
exp
(
-
a
j
2
2
σ
a
2
)
2
π
σ
z
2
]
∏
j
=
1
N
[
exp
(
-
b
j
2
2
σ
b
2
)
2
π
σ
b
2
]
(
29
)
=
∏
j
=
2
N
[
exp
(
-
(
x
j
-
φ
x
j
-
1
)
2
2
σ
a
2
)
2
πσ
z
2
]
∏
j
=
1
N
[
exp
(
-
(
y
j
-
x
j
)
2
2
σ
b
2
)
2
πσ
b
2
]
.
(
30
)
[0079] The probability density for a given set of measurements is obtained by integrating over all trajectories,
[0000]
p
(
{
y
j
}
|
φ
,
σ
a
2
,
σ
b
2
)
=
∫
p
(
{
x
j
}
,
{
y
j
}
|
φ
,
σ
a
2
,
σ
b
2
)
x
1
…
dx
N
=
(
2
πσ
a
2
σ
b
2
)
-
N
-
1
2
σ
b
2
det
(
A
φ
)
exp
(
-
1
2
σ
b
2
(
y
→
)
T
[
I
-
A
φ
-
1
σ
b
2
]
y
→
)
,
(
31
)
[0080] where {right arrow over (y)}=(y 1 . . . y N ), ({right arrow over (y)}) T is its transpose, I is the N×N identity matrix, and
[0000]
A
φ
=
I
σ
b
2
+
M
φ
σ
a
2
,
(
32
)
[0000] with the memory tensor
[0000]
M
φ
=
(
φ
2
-
φ
0
0
…
0
-
φ
1
+
φ
2
-
φ
0
…
⋮
0
-
φ
1
+
φ
2
-
φ
…
⋮
0
0
-
φ
⋱
…
⋮
⋮
⋮
…
-
φ
1
+
φ
2
-
φ
0
0
…
0
-
φ
1
)
.
(
33
)
[0081] Calculating the determinant, det(A φ ), and inverse A φ −1 , is greatly facilitated if time translation invariance is artificially imposed by replacing M φ with the (N+1)×(N+1) matrix
[0000]
M
^
φ
=
(
1
+
φ
2
-
φ
0
0
…
-
φ
-
φ
1
+
φ
2
-
φ
0
…
⋮
0
-
φ
1
+
φ
2
-
φ
…
⋮
0
0
-
φ
⋱
…
⋮
⋮
⋮
…
-
φ
1
+
φ
2
-
φ
-
φ
0
…
0
-
φ
1
+
φ
2
)
.
(
34
)
[0082] Physically, this involves imparting an impulse, α N+1 , that translates the particle from its last position, x N , to its first, x 1 . Because diffusion in a potential well is a stationary process, the effect of this change decays as 1/N in the number of measurements, and so is less important than other sources of error.
[0083] With this approximation, the determinant and inverse of A φ are given by
[0000]
det
(
A
φ
)
=
∏
n
=
1
N
{
1
σ
b
2
+
1
σ
a
2
[
1
+
φ
2
-
2
φ
cos
(
2
π
n
N
)
]
}
and
(
35
)
(
A
φ
-
1
)
αβ
=
1
N
∑
n
=
1
N
σ
a
2
σ
b
2
exp
(
2
π
N
n
(
α
-
β
)
)
σ
a
2
+
σ
b
2
[
1
+
φ
2
-
2
φ
cos
(
2
π
n
N
)
]
,
(
36
)
[0000] so that the conditional probability for the measured trajectory, {y j }, is
[0000]
p
(
{
y
j
}
|
φ
,
σ
a
2
,
σ
b
2
)
=
(
2
π
)
-
N
2
exp
(
-
1
2
σ
b
2
∑
n
=
1
N
y
n
2
)
×
∏
n
=
1
N
{
σ
a
2
+
σ
b
2
[
1
+
φ
2
-
2
φcos
(
2
π
n
N
)
]
}
-
1
2
×
exp
(
1
2
σ
b
2
1
N
∑
m
=
1
N
y
m
2
σ
a
2
σ
a
2
+
σ
b
2
[
1
+
φ
2
-
2
φcos
(
2
π
m
N
)
]
)
.
(
37
)
[0084] This can be inverted to obtain the likelihood function for φ, σ a 2 and σ b 2 :
[0000]
L
(
φ
,
σ
a
2
,
σ
b
2
|
{
y
i
}
)
=
-
N
2
ln
2
π
-
1
2
σ
b
2
∑
j
=
n
N
y
n
2
-
1
2
∑
n
=
1
N
ln
(
σ
a
2
+
σ
b
2
[
1
+
φ
2
-
2
φcos
(
2
π
n
N
)
]
)
+
σ
a
2
2
σ
b
2
1
N
∑
n
=
1
N
y
n
2
σ
a
2
σ
a
2
+
σ
b
2
[
1
+
φ
2
-
2
φcos
(
2
π
n
N
)
]
.
(
38
)
[0085] Best estimates ({circumflex over (φ)}, {circumflex over (σ)} a 2 , {circumflex over (σ)} b 2 ) for the parameters (φ, σ a 2 , σ b 2 ) are solutions of the coupled equations
[0000]
∂
L
∂
φ
=
∂
L
∂
σ
a
2
=
∂
L
∂
σ
b
2
=
0.
(
39
)
[0086] Eq. (39) can be solved in closed form if σ b 2 =0. In this case, the best estimates for the parameters are
[0000]
φ
^
0
=
c
1
c
0
,
and
(
40
)
σ
^
a
0
2
=
c
0
[
1
-
(
c
1
c
0
)
2
]
,
where
(
41
)
c
m
=
1
N
∑
j
=
1
N
y
j
y
(
j
+
m
)
mod
N
(
42
)
[0000] is the barrel autocorrelation of {y j } at lag m. The associated statistical uncertainties are
[0000]
Δ
φ
^
0
=
σ
^
a
0
2
N
c
0
,
and
(
43
)
Δ
σ
^
a
0
2
=
σ
^
a
0
2
2
N
.
(
44
)
[0087] In the absence of measurement errors, just two descriptors, c 0 and c 1 , contain all of the information that can be extracted from the time series regarding φ and σ a 2 . These are examples of sufficient statistics that completely specify the system's dynamics.
[0088] The analysis is less straightforward when a σ b 2 ≠0 because Eqs. (39) no longer are simply separable. The system of equations can be solved at least approximately provided the measurement error σ b 2 is smaller than σ a 2 . In this case, the best estimates for the parameters can be expressed in terms of the error-free estimates as
[0000]
φ
^
≈
φ
^
0
{
1
+
σ
b
2
σ
^
a
0
2
[
1
-
φ
^
0
2
+
c
2
c
0
]
}
,
and
(
45
)
σ
^
a
2
≈
σ
^
a
0
2
-
σ
b
2
σ
^
a
0
2
c
0
[
1
-
5
φ
^
0
4
+
4
φ
^
0
2
c
2
c
0
]
,
(
46
)
[0000] to first order in σ b 2 /σ a 2 , with statistical uncertainties propagated in the conventional manner. The sufficient statistics at this level of approximation include just one additional moment, c 2 . Expansions to higher order in σ b 2 /σ a 2 require additional correlations to be completed, and the exact solution requires correlations at all lags m. Such a complete analysis offers no computational benefits over power spectral analysis, for example. It does, however, provide a systematic approach to estimating experimental uncertainties. If the measurement error is small enough for Eqs. (45) and (46) to apply, the computational savings can be substantial, and the amount of data required to achieve a desired level of accuracy in the physically relevant quantities, κ and γ, can be reduced dramatically.
[0089] The errors in locating colloidal particles' centroids can be calculated from knowledge of the images' signal to noise ratio and the optical train's magnification. Centroid resolutions of 10 nm or better can be routinely attained for micrometer-scale colloidal particles in water using conventional bright-field imaging. In practice, however, mechanical vibrations, video jitter and other processes may increase the measurement error by amounts that can be difficult to independently quantify. Quite often, the overall measurement error is most easily assessed by increasing the laser power to the optical traps to minimize the particles' thermally driven motions. In this case, y j ≈b j , and the measurement error's variance σ b 2 can be estimated directly.
[0000]
κ
k
B
T
=
1
-
φ
^
2
σ
^
a
2
,
and
(
47
)
γ
k
B
T
Δ
t
=
-
1
-
φ
^
2
σ
^
a
2
ln
φ
^
,
(
48
)
[0000] with error estimates, Δκ and Δγ, given by
[0000]
(
Δκ
κ
)
2
=
(
Δ
σ
^
a
2
σ
^
a
2
)
2
+
(
2
φ
^
2
1
-
φ
^
2
)
2
(
Δ
φ
^
φ
^
)
2
(
49
)
(
Δγ
γ
)
2
=
(
Δ
σ
^
a
2
σ
^
a
2
)
2
+
(
2
φ
^
2
1
-
φ
^
2
-
1
ln
φ
^
)
2
(
Δ
φ
^
φ
^
)
2
.
(
50
)
[0090] If the measurement interval Δt is much longer than the viscous relaxation time τ=γ/κ, then φ vanishes and the error in the drag coefficient diverges. Conversely, if Δt is much smaller than τ, then φ approaches unity and both errors diverge. Consequently, this approach to trap characterization does not benefit from excessively fast sampling. Rather, it relies on accurate particle tracking to minimize Δ{circumflex over (φ)} and Δ{circumflex over (σ)} a 2 . For trap-particle combinations with viscous relaxation tunes of several milliseconds or longer and typical particle excursions of at least 10 nm, digital video microscopy provides both the temporal and spatial resolution needed to completely characterize optical traps. This approach also lends itself to simultaneous characterization of multiple traps, which is not possible with conventional methods.
[0091] In the event that measurement errors can be ignored (σ b 2 <<σ a 2 ), the physically relevant quantities can be obtained as:
[0000]
κ
0
k
B
T
=
1
c
0
[
1
±
2
N
(
1
+
2
c
1
2
c
0
2
-
c
1
2
)
]
(
51
)
γ
0
k
B
T
Δ
t
=
1
c
0
ln
(
c
0
c
1
)
(
1
±
Δ
γ
0
γ
0
)
,
where
N
(
Δ
γ
0
γ
0
)
2
=
2
+
1
c
0
2
-
c
1
2
[
c
1
2
-
2
c
1
c
0
ln
(
c
0
c
1
)
-
c
0
2
c
0
ln
(
c
0
c
1
)
]
2
.
(
52
)
[0092] These results are not reliable if c 1 ≦σ b 2 , which when the sampling interval, Δt is much longer or shorter than the viscous relaxation time, τ. Accurate estimates for κ and γ still may be obtained in this case by applying Eqs. (45) and (46) or their generalizations.
[0093] Optimal statistical analysis offers insights not only into the traps' properties, but also into the properties of the trapped particles and the surrounding medium. For example, if a spherical probe particle is immersed in a medium of viscosity η far from any bounding surfaces, its hydrodynamic radius a can be assessed from the measured drag coefficient using the Stokes result γ=6 π ηa. The viscous drag coefficients also provide insights into the particles' coupling to each other and to their environment. The independently assessed values of the traps' stiffness then can serve as a self-calibration in microrheological measurements and in measurements of colloidal many-body hydrodynamic coupling. In cases where the traps themselves must be accurately calibrated, knowledge of the probe particles' differing properties gauged from measurements of γ can be used to distinguish variations in the traps' intrinsic properties from variations due to differences among the probe particles. The apparent width and depth of the potential energy well a particle experiences when it encounters an optical trap depends on its size in a manner that can be inverted at least approximately.
[0094] These measurements, moreover, can be performed rapidly enough, even at conventional video sampling rates, to permit real-time adaptive optimization of the traps' properties. Each trap's stiffness is roughly proportional to its brightness. Therefore, if the m-th trap in an array is intended to receive a fraction |αm| 2 of the projected light, then its stiffness should satisfy
[0000]
κ
m
∑
i
=
1
N
κ
i
=
α
m
2
(
53
)
[0095] Any departure from this due to fixed instrumental deficiencies can be corrected by modifying the design amplitudes,
[0000]
α
m
→
α
m
∑
i
=
1
N
κ
i
κ
m
,
(
54
)
[0000] and recalculating the CGH.
[0096] As a practical demonstration of the utility of the present invention, a challenging pattern of optical traps is calculated, projected, and characterized in a quasiperiodic array. The traps are formed with a 100×NA 1.4 S-Plan Apo oil immersion objective lens mounted in a Nikon TE-2000U inverted optical microscope. The traps are powered by a Coherent Verdi frequency-doubled diode-pumped solid state laser operating at a wavelength of 532 nm. Computer-generated phase holograms are imprinted on the beam with a Hamamatsu X8267-16 parallel-aligned nematic liquid crystal spatial light modulator (SLM). This SLM can impose phase shifts up to 2 π radians at each pixel in a 760×760 array. The face of the SLM is imaged onto the objective's 5 mm diameter input pupil using relay optics designed to minimize aberrations. The beam is directed into the objective with a dichroic beamsplitter (Chroma Technologies), which allows images to pass through to a low-noise charge-coupled device (CCD) camera (NEC TI-324AII). The video stream is recorded as uncompressed digital video with a Pioneer digital video recorder (DVR) for processing.
[0097] FIG. 4( a ) shows the intended planar arrangement of 119 holographic optical traps. Even after adaptive-additive refinement, the hologram resulting from simple superposition with random phase fares poorly for this aperiodic pattern. FIG. 4( b ) shows the intensity of light reflected by a front-surface mirror placed in the sample plane. This image reveals several undesirable defects including extraneous ghost traps, an exceptionally bright central spot, and large variability in intensity. Imaging photometry on this and equivalent images produced with different random relative phases for the beams yields a typical root-mean-square variation of more than 50 percent in the projected traps' brightness. The image in FIG. 4( c ) was produced using the modified optical train and the direct search algorithm described earlier. This image suffers from none of these defects exemplified in FIG. 4( b ). Both the ghost traps and the central spot are suppressed, and the apparent relative brightness variations are smaller than 5 percent, an improvement by a factor of ten.
[0098] The real test of these optical tweezers, however, is their performance at trapping particles. FIG. 4( d ) shows 119 colloidal silica spheres, 2a=1.6±0.2 μm pin in diameter, dispersed in water at T=40° C. The viscosity is roughly η=1 cP. The dispersion was sealed into a slit pore formed by sealing the edges of a glass #1.5 cover slip to the surface of a glass microscope slide. The array of traps was focused roughly 10 μm above the inner surface of the coverslip in a layer roughly 40 μm thick. The traps were separated by 7 μm, so that hydrodynamic coupling among the spheres should modify their individual drag coefficients by no more than ten percent, which is comparable to the effect of the nearby wall. Imaging spheres in smaller trapping patterns at a projected power of 30 mW per trap suggests that the overall measurement error for the particles' centroids is σ b 2 =5 nm 2 .
[0099] Reducing the laser power to 2 mW per trap frees the particles to explore the traps' potential energy wells. The particles were tracked both along the line of traps (the {circumflex over (x)} direction) and perpendicular to it (the ŷ direction), and analyzed both coordinates separately, using the methods discussed herein. It was shown that the traps' strengths do indeed vary by more than the typical measurement error, but that the variation is less than 5 percent. If the variations were larger, information from this measurement could be used to adjust the amplitudes α m in Eq. (5) to correct for fixed variations in the optical train's performance.
B. Flux Reversal in Symmetric Optical Thermal Ratchets
[0100] The ability to rectify Brownian forces with spatially extended time-varying light fields creates new opportunities for leveraging the statistical properties of thermal ratchets and to exploit them by their interesting and useful properties for practical applications. In these embodiments a one-dimensional thermal ratchet implemented with the holographic optical trapping technique applied to fluid-borne colloidal spheres. The complementary roles of global spatiotemporal symmetry and local dynamics are presented in relation to establishing the direction of ratchet-induced motion and also present applications in higher-dimensional systems.
[0101] Thermal ratchets employ time-varying potential energy landscapes to break the spatiotemporal symmetry of thermally equilibrated systems. The resulting departure from equilibrium takes the form of a directed flux of energy or materials, which can be harnessed for natural and practical applications. Unlike conventional macroscopic machines whose efficiency is reduced by random fluctuations, thermal ratchets actually can utilize noise to operate. They achieve their peak efficiency when their spatial and temporal evolution is appropriately matched to the scale of fluctuations in the heat bath.
[0102] Most thermal ratchet models involve locally asymmetric space-filling potential energy landscapes, and almost all are designed to operate in one dimension. Most practical implementations have exploited microfabricated structures such as interdigitated electrode arrays, quantum dot arrays, periodic surface textures, or microfabricated pores for hydrodynamic drift ratchets. Previous optical implementations have used a rapidly scanned optical tweezer to create an asymmetric one-dimensional potential energy landscape in a time-averaged sense, or a time-varying dual-well potential with two conventional optical traps.
[0103] This embodiment includes a broad class of optical thermal ratchets that exploit the holographic optical tweezer technique to create large-scale dynamic potential energy landscapes. This approach permits detailed studies of the interplay of global spatiotemporal symmetry and local dynamics in establishing both the magnitude and direction of ratchet-induced fluxes. It also provides for numerous practical applications.
[0104] Holographic optical tweezers use computer-generated holograms to project large arrays of single-beam optical traps. One implementation, shown schematically in FIG. 5( a ), uses a liquid crystal spatial light modulator 100 (SLM) (Hamamatsu X7550 PAL-SLM) to imprint phase-only holograms on the wavefronts of a laser beam 102 from a frequency-doubled diode-pumped solid state laser 104 operating at 532 nm (Coherent Verdi). This SLM 100 can vary the local phase, φ(r), between 0 and 2πradians at each position r in a 480×480 grid spanning the beam's wavefront. A modulated beam 106 is relayed to the input pupil of a 100×NA 1.4 SPlan Apo oil immersion objective lens 108 mounted in an inverted optical microscope 110 (Zeiss S-100TV). The objective lens 108 focuses the light into a pattern of optical traps that can be updated in real time by transmitting a new phase pattern to the SLM.
[0105] FIG. 5( b ) shows the focused light, l({right arrow over (r)}) from a typical pattern of holographic optical traps, which is imaged by placing a front-surface mirror on the sample stage and collecting the reflected light with the objective lens 108 . Each focused spot of light in this 20×5 array constitutes a discrete optical tweezer, which acts as a spatially symmetric three-dimensional potential energy well for a micrometer-scale object. FIG. 5( b ) shows an aqueous dispersion of 1.53 μm diameter colloidal silica spheres (Bangs Laboratories, lot number 5328) interacting with this pattern of traps at a projected laser power of 2.5 mW/trap.
[0106] Each potential well may be described as a rotationally symmetric Gaussian potential well. Arranging the traps in closely spaced manifolds separated by a distance L creates a pseudo-one-dimensional potential energy landscape, V(x), which can be modeled as
[0000]
V
(
x
)
=
-
V
0
∑
n
=
-
N
N
exp
(
-
(
x
-
nL
)
2
2
σ
2
)
.
(
55
)
[0107] The well depth, V 0 , approaches the thermal energy scale, β −1 , when each optical tweezer is powered with somewhat less than 1 mW of light. The holographically projected traps' strengths are uniform to within ten percent. Their widths, σ are comparable to the spheres' radii. With the traps powered by 3 mW, diffusing particles are rapidly localized by the first optical tweezer they encounter, as can be seen from the center photograph in FIG. 5( c ).
[0108] The potential energy landscape created by a holographic optical tweezer array differs from most ratchet potentials in two principal respects. In the first place, the empty spaces between manifolds comprise large force-free regions. This contrasts with most models, which employ space-filling landscapes. The landscape can induce motion only if random thermal fluctuations enable particles to diffuse across force-free regions. Secondly, the landscape is spatially symmetric, both globally and locally. Breaking spatiotemporal symmetry to induce a flux rests, therefore, with the landscape's time evolution. Details of the protocol can determine the nature of the induced motion.
[0109] The most straightforward protocols for holographic optical thermal ratchets involve cyclically translating the landscape by discrete fractions of the lattice constant L, with the n-th state in each cycle having duration T n . The motion of a Brownian particle in such a system can be described with the one-dimensional Langevin equation
[0000] γ{dot over ( x )}( t )=− V ′( x ( t )−ƒ( t ))+ξ( t ), (56)
[0000] where y is the particle's viscous drag coefficient, the prime denotes a derivative with respect to the argument, and ξ(t) is a stochastic force representing thermal noise. This white-noise forcing satisfies ξ(t) =0 and ξ(t)ξ(s) =2(y|β)δ(t−s).
[0110] The potential energy landscape in our system is spatially periodic:
[0000] V ( x+L )= V ( x ). (57)
[0111] The discrete displacements in an N-state cycle, furthermore, also are described by a periodic function ƒ(t), with period T=Σ n−1 N T n . That a periodically driven, symmetric and spatially periodic potential can rectify Brownian motion to generate a directed flux might not be immediately obvious. Directed motion in time-evolving landscapes is all but inevitable, with flux-free operation being guaranteed only if V(x) and ƒ(t) satisfy specific conditions of spatiotemporal symmetry,
[0000] V ( x )= V (− x ), and {dot over (ƒ)}( t )=−{dot over (ƒ)}( t+T/ 2), (58)
[0000] and spatiotemporal supersymmetry,
[0000] V ( x )=− V ( x+L/ 2), and {dot over (ƒ)}( t+Δt )=−{dot over (ƒ)}(− t ) (59)
[0000] for at least one value of Δt. The dot in Eqs. (58) and (59) denotes a time derivative. Two distinct classes of one-dimensional optical thermal ratchets that exploit these symmetries in different ways are presented herein. The first results in directed diffusion except for a particular operating point, at which Eq. (58) is satisfied. The second has a point of flux-free operation even though Eqs. (58) and (59) are always violated. In both cases, the vanishing point signals a reversal of the direction of the induced flux.
[0112] The simplest optical ratchet protocol involves a two-state cycle,
[0000]
f
(
t
)
=
{
0
,
0
≤
(
t
mod
T
)
<
T
1
L
3
T
1
≤
(
t
mod
T
)
<
T
(
60
)
[0113] This protocol explicitly satisfies the symmetry condition in Eq. (58) when the two states are of equal duration, T 1 =T 2 =T/2. This particular operating point therefore should create a flux-free nonequilibrium steady-state, with particles being juggled back and forth between neighboring manifolds of traps. Breaking spatiotemporal symmetry by setting T 1 ≠T 2 does not guarantee a flux, but at least creates the possibility.
[0114] FIG. 6 presents flux induced by a two-state holographic optical ratchet. Discrete points show measured mean drift speed as a function of T 2 for T 1 =3 sec. The solid curve is a fit to the data for βV 0 =2.75 and σ=0.65 μm. Other curves show how the induced drift depends on T/τ, with optimal flux obtained for T/τ=0.193.
[0115] The data in FIG. 6 demonstrate that this possibility is borne out in practice. The discrete points in FIG. 6 show the measured average drift velocity, ν, for an ensemble of colloidal silica spheres 1.53 μm in diameter dispersed in a 40 μm thick layer of water between a coverslip and a microscope slide. The spheres are roughly twice as dense as water and rapidly sediment into a free-floating layer above the coverslip. The holographic optical tweezer array was projected into the layer's midplane to minimize out-of-plane fluctuations, with an estimated power of 1 mW/trap. Roughly 30 spheres were in the trapping domain at any time, so that reasonable statistics could be amassed in 10 minutes despite the very large fluctuations inherent in thermal ratchet operation. This number is small enough, moreover, to minimize the rate of collisions among the particles.
[0116] Given the spheres' measured diffusion coefficient of D=0; 0.33 μm 2 /sec., the time required to diffuse the inter-manifold separation of L=5.2 μm is τ=L 2 /(2D)=39 sec. This establishes a natural velocity scale, L/τ, in which ν is presented. These data were acquired with T 1 =3 sec. and T 2 varying from 0.8 sec to 14.7 sec.
[0117] As anticipated, the ratchet-induced flux vanishes at the point of spatiotemporal symmetry, T 2 =T 1 , and is non-zero otherwise. The vanishing point signals a reversal in the direction of the drift velocity, with particles being more likely to advance from the wells in the longer-lived state toward the nearest manifold in the shorter-lived state. This trend can be understood as resulting from the short-duration state's biasing the diffusion of particles away from their localized distribution in the long-lived state.
[0118] To make this qualitative argument more concrete, it is possible to calculate the steady-state velocity for particles in this system by considering the evolution of the probability density ρ(x,t) for finding a particle within dx of position x at time t. The Fokker-Planck equation associated with Eq. (2) is:
[0000]
∂
ρ
(
x
,
t
)
∂
t
=
D
[
∂
2
∂
x
2
ρ
(
x
,
t
)
+
β
∂
∂
x
{
ρ
(
x
,
t
)
V
′
(
x
-
f
(
t
)
)
}
]
,
(
61
)
[0000] where the prime denotes a derivative with respect to the argument. Equation (61) is formally solved by the master equation
[0000] ρ( x,t+T )=∫ P ( x,T|x 0 ,0)ρ( x 0 ,t ) dx 0 (62)
[0000] for the evolution of the probability density, with the propagator
[0000] P ( x,t|x 0 ,0)=exp(∫ t L ( x,t ′) dt ′)δ( x−x 0 ) (63)
[0000] describing the transfer of particles from x 0 to x under the Liouville operator
[0000]
L
(
x
,
t
)
=
D
(
∂
2
∂
x
2
+
β
∂
∂
x
V
′
(
x
-
f
(
t
)
)
)
.
(
64
)
[0119] From Eq. (62), it follows that the steady-state particle distribution ρ(x) is an eigenstate of the propagator,
[0000] ρ( x )=∫ P ( x,t|x 0 ,0)ρ( x 0 ) dx 0 , (65)
[0000] associated with one complete cycle. The associated steady-state flux is
[0000]
v
=
∫
x
-
x
0
T
ρ
(
x
0
)
P
(
x
,
T
|
x
0
,
0
)
x
x
0
.
(
66
)
[0120] FIG. 7( a ) presents Stochastic resonance in the two-state optical thermal ratchet for σ/L=0.125 with dependence on cycle period T in units of the diffusive time scale τ for βV 0 =2.5 at the optimal duty cycle T 2 /T 1 =0.3. FIG. 7( b ) presents dependence on well depth for the optimal cycle rate T 2 /T 1 =0.193 and duty cycle.
[0121] The solid curve in FIG. 6 is a fit of Eq. (66) to the measured particle fluxes for βV 0 =2.5 and σ=0.65 μm. The additional curves in FIG. 6 show how ν varies with T 2 /T 1 for various values of T/τ for these control parameters. The induced flux, ν, plotted in FIG. 7( a ), falls off as 1/T in the limit of large T because the particles spend increasingly much of their time localized in traps. It also vanishes in the opposite limit because the diffusing particles cannot keep up with the landscape's evolution. The optimal cycle period at T/τ≈0.2 constitutes an example of stochastic resonance. Although a particle's diffusivity controls the speed with which it traverses the ratchet, its direction is uniquely determined by T 2 /T 1 .
[0122] No flux results if the traps are too weak. Increasing the potential wells' depths increases the maximum attainable flux, but only up to a point. If the traps are too strong, particles also become localized in the short-lived state, and the ratchet approaches a deterministic flux-free limit in which particles simply hop back and forth between neighboring manifolds. This behavior is shown in FIG. 7( b ).
[0123] Different objects exposed to the same time-evolving optical intensity pattern experience different values of V 0 and σ, and also can have differing diffusive time scales, τ. Such differences establish a dispersion of mean velocities for mixtures of particles moving through the landscape that can be used to sorting the particles. Despite this method's symmetry and technical simplicity, however, the two-state protocol is not the most effective platform for such practical applications. A slightly more elaborate protocol yields a thermal ratchet whose deterministic limit transports material rapidly and whose stochastic limit yields flux reversal at a point not predicted by the symmetry selection rules in Eqs. (58) and (59).
[0124] In another embodiment, the next step up in complexity and functional richness involves the addition of a third state to the ratchet cycle:
[0000]
f
(
t
)
=
{
0
,
0
≤
(
t
mod
T
)
<
T
3
L
3
,
T
3
≤
(
t
mod
T
)
<
2
T
3
-
L
3
,
2
T
3
≤
(
t
mod
T
)
<
T
}
.
(
67
)
[0125] This three-state cycle consists of cyclic displacements of the landscape by one third of a lattice constant. Unlike the two-state symmetric thermal ratchet, it has a deterministic limit, an explanation of which helps to elucidate its operation in the stochastic limit.
[0126] If the width, σ, of the individual wells is comparable to the separation L/3 between manifolds in consecutive states, then a particle localized at the bottom of a well in one state is released near the edge of a well in the next. Provided V 0 is large enough, the particle falls to the bottom of the new well during the T/3 duration of the new state. This process continues through the sequence of states, and the particle is transferred deterministically forward from manifold to manifold. This deterministic process is known as optical peristalsis, and is useful for reorganizing fluid-borne objects over large areas with simple sequences of generic holographic trapping patterns.
[0127] Assuming the individual traps are strong enough, optical peristalsis transfers objects forward at speed ν=L/T. If, on the other hand, βV 0 <1, particles can be thermally excited out of the forward-going wave of traps and so will travel forward more slowly. This is an example of a deterministic machine's efficiency being degraded by thermal fluctuations. This contrasts with the two-state thermal ratchet, which has no effect in the deterministic limit and instead relies on thermal fluctuations to induce motion.
[0128] The three-state protocol enters its stochastic regime when the inter-state displacement of manifolds, L/3, exceeds the individual traps' width, σ. Under these conditions, a particle that is trapped in one state is released into the force-free region between traps once the state changes. If the particle diffuses rapidly enough, it might nevertheless fall into the nearest potential well centered a distance L/3 away in the forward-going direction within time T/3. The fraction of particles achieving this will be transferred forward in each step of the cycle. This stochastic process resembles optical peristalsis, albeit with reduced efficiency. There is a substantial difference, however.
[0129] An object that does not diffuse rapidly enough to reach the nearest forward-going trap in time T/3 might still reach the trap centered at −L/3 in the third state by time 2T/3. Such a slow-moving object would be transferred backward by the ratchet at velocity ν=−L/(2). Unlike the two-state ratchet, whose directionality is established unambiguously by the sequence of states, the three-state ratchet's direction appears to depend also on the transported objects' mobility.
[0130] FIG. 8( a ) presents flux reversal in a symmetric three-state optical thermal ratchet and depicts this as a function of cycle period for fixed inter-manifold separation, L. FIG. 8( b ) shows this as a function of inter-manifold separation L for fixed cycle period T.
[0131] These observations above are borne out by the experimental observations in FIGS. 8( a ) and 8 ( b ). The discrete points in FIG. 8( a ) show the measured flux of 1.53 μm diameter silica spheres as a function of the cycle period T with the inter-manifold separation fixed at L=6.7 μm. Flux reversal at T/τ≈0.1 does not result from special symmetry considerations because the spatiotemporal evolution described by Eqs. (55) and (67) violates the conditions in Eqs. (58) and (59) for all values of T. Rather, this reflects a dynamical transition in which rapidly diffusing particles are driven in the forward while slowly diffusing particles drift backward. The origin of this transition in thermal ratchet behavior is confirmed by the observation of a comparable transition induced by varying the inter-manifold separation L for fixed cycle period T, as plotted in FIG. 8( b ).
[0132] FIG. 9 presents calculated ratchet-induced drift velocity as a function of cycle period T for representative values of the inter-manifold separation L ranging from the deterministic limit, L=6.5σ to the stochastic limit L=13σ.
[0133] The solid curves in FIGS. 8( a ) and 8 ( b ) are fits to Eq. (66) using Eq. (67) to calculate the propagator. The fit values, βV 0 =8.5±0.08 and σ=0.53±0.01 μm are consistent with values obtained for the two-state ratchet, given a higher laser power of 2.5 mW/trap. The crossover from deterministic optical peristalsis with uniformly forward-moving flux at small L to stochastic operation with flux reversal at larger separations is captured in the calculated drift velocities plotted in FIG. 9 .
[0134] Whereas flux reversal in the two-state ratchet is mandated by the protocol, flux reversal in the three-state ratchet depends on properties of diffusing objects through the detailed structure of the probability distribution ρ(x) under different operating conditions. The three-state optical thermal ratchet therefore provides the basis for sorting applications in which different fractions of a mixed sample are transported in opposite directions by a single time-evolving optical landscape. This builds upon previously reported ratchet-based fractionation techniques which rely on unidirectional motion.
C. Radial Ratchet
[0135] The flexibility of holographic optical thermal ratchet implementations and the success of our initial studies of one-dimensional variants both invite consideration of thermal ratchet operation in higher dimensions. This is an area that has not received much attention, perhaps because of the comparative difficulty of implementing multidimensional ratchets with other techniques. As an initial step in this direction, it is possible to introduce a ratchet protocol in which manifolds of traps are organized into evenly spaced concentric rings whose radii advance through a three-state cycle analogous to that in Eq. (67). The probability distribution p(r,t) for a Brownian particle to be found within dr of r at time t under external force F(r,t)=−∇V(r,t) satisfies
[0000]
∂
p
(
r
,
t
)
∂
t
=
D
[
∇
2
p
(
r
,
t
)
-
β
∇
·
{
p
(
r
,
t
)
F
(
r
,
t
)
}
]
.
(
68
)
[0136] If the force depends only on the radial coordinate as F(r,t)=−∂V(r,t) {circumflex over (r)}, Eq. (68) reduces to
[0000]
∂
p
(
r
,
t
)
∂
t
=
D
[
1
r
∂
∂
r
{
r
∂
∂
r
p
(
r
,
t
)
}
+
β
r
∂
∂
r
{
rV
′
(
r
,
t
)
p
(
r
,
t
)
}
]
.
(
69
)
[0137] The probability p(r,t) for a particle to be found between r and r+dr at time t is given by p(r,t)=2πrp(r,t). Therefore, the Fokker-Planck equation can be rewritten in terms of p(r,t) as
[0000]
∂
ρ
(
r
,
t
)
∂
t
=
D
[
∂
2
∂
r
2
ρ
(
r
,
t
)
+
β
∂
∂
r
{
(
V
′
(
r
,
t
)
-
1
β
r
)
ρ
(
r
,
t
)
}
]
.
(
70
)
[0138] This, in turn, can be reduced to the form of Eq. (61) by introducing the effective one-dimensional potential V eff (r,t)≡V(r−ƒ(t))−β −1 1 nr. The rest of the analysis follows by analogy to the linear three-state ratchet.
[0139] FIGS. 10( a )- 10 ( d ) present fractionation in a radial optical thermal ratchet. FIG. 10( a ) presents the pattern of concentric circular manifolds with L=4.7 μm. FIG. 10( b ) presents a mixture of large and small particles interacting with a fixed trapping pattern. FIG. 10( c ) presents small particles collected and large excluded at L=4.9 μm and T=4.5 sec. FIG. 10( d ) presents large particles concentrated at L=5.3 μm and T=4.5 sec. The scale bar indicates 10 μm.
[0140] Like the linear variant, the three-state radial ratchet has a deterministic operating regime in which objects are clocked inward or outward depending on the sequence of states. The additional geometric term in V eff (r) and the constraint that r>0 substantially affect the radial ratchet's operation in the stochastic regime by inducing a position-dependent outward drift. In particular, a particle being drawn inward by the ratchet effect must come to a rest at a radius where the ratchet-induced flux is balanced by the geometric drift. Outward-driven particles, by contrast, are excluded by the radial ratchet. Combining this effect with the three-state ratchet's natural propensity for mobility-dependent flux reversal suggests that radial ratchet protocols can be designed to sort mixtures in the field of view, expelling the unwanted fraction and concentrating the target fraction. This behavior is successfully demonstrated in FIG. 10( c ), in which 1 μm diameter silica spheres (Bangs Laboratories, lot number 21024) have been collected within an outward-driving radial ratchet at L=4.9 μm at T−4.5 sec. while larger 1.53 μm diameter silica spheres are expelled, and in FIG. 10( d ), in which the opposite is achieved with an inward-driving ratchet at L=5.3 μm and the same period, T=4.5 sec. A larger and more refined version might sort different fractions into concentric rings within the ratchet domain. This capability might find applications in isolating and identifying individual bacterial species within biofilms, for example.
[0141] This embodiment of the invention provides for one-dimensional thermal ratchet models implemented with holographic optical tweezer arrays. The use of discrete optical tweezers to create extensive potential energy landscapes characterized by large numbers of locally symmetric potential energy wells provides a practical method for thermal ratchet behavior to be induced in large numbers of diffusing objects in comparatively large volumes. The particular applications described herein all can be reduced to one-dimensional descriptions, and are conveniently analyzed with the conventional Fokker-Planck formalism. In each case, the ratchet-induced drift is marked by an operating point at which the flux reverses. In symmetric two-state traveling ratchets, flux reversal occurs at a point predicted by Reimann's symmetry selection rules. The three-state variants, on the other hand, undergo flux reversal as a consequence of a competition between the landscapes' temporal evolution and the Brownian particles' diffusion. The latter mechanism, in particular, suggests opportunities for practical sorting applications.
[0142] The protocols described herein can be generalized in several ways. The displacements between states, for example, could be selected to optimize transport speed or to tune the sharpness of the flux reversal transition for sorting applications. Similarly, the states in our three-state protocol need not have equal durations. They also might be tuned to optimize sorting, and perhaps to select a particular fraction from a mixture. The limiting generalization is a pseudo-continuous traveling ratchet with specified temporal evolution, ƒ(t). The present embodiment uses manifolds of traps which may all be of the same geometry and intensity. The present invention may also use manifolds of traps where the geometry and intensity are not all the same. These characteristics also can be specified, with further elaborations yielding additional control over the ratchet-induced transport. The protocols described here are useful for dealing with the statistical mechanics of symmetric traveling ratchets and may be used in practical applications.
[0143] Just as externally driven colloidal transport through static two-dimensional arrays of optical traps gives rise to a hierarchy of kinetically locked-in states, ratchet-induced motion through two-dimensional and three-dimensional holographic optical tweezer arrays is likely to be complex and interesting. Various other proposed higher-dimensional ratchet models have been experimentally implemented. None of these has explored the possibilities of scaling ratchets resembling the radial ratchet introduced here but with irreducible two- or three-dimensional structure.
D. Flux Reversal in Three State Thermal Ratchets
[0144] A cycle of three holographic optical trapping patterns can implement a thermal ratchet for diffusing colloidal spheres, and the ratchet-driven transport displays flux reversal as a function of the cycle frequency and the inter-trap separation. Unlike previously described ratchet models, the present invention involves three equivalent states, each of which is locally and globally spatially symmetric, with spatiotemporal symmetry being broken by the sequence of states.
[0145] Brownian motion cannot create a steady flux in a system at equilibrium. Nor can local asymmetries in a static potential energy landscape rectify Brownian motion to induce a drift. A landscape that varies in time, however, can eke a flux out of random fluctuations by breaking spatiotemporal symmetry. Such flux-inducing time-dependent potentials are known as thermal ratchets, and their ability to bias diffusion by rectifying thermal fluctuations has been proposed as a possible mechanism for transport by molecular motors and is being actively exploited for macromolecular sorting.
[0146] Most thermal ratchet models are based on spatially asymmetric potentials. Their time variation involves displacing or tilting them relative to the laboratory frame, modulating their amplitude, changing their periodicity, or some combination, usually in a two-state cycle. Thermal ratcheting in a spatially symmetric double-well potential has been demonstrated for a colloidal sphere in a pair of intensity modulated optical tweezers. More recently, directed transport has been induced in an atomic cloud by a spatially symmetric rocking ratchet created with an optical lattice.
[0147] The space-filling potential energy landscapes required for most such models pose technical challenges. Furthermore, their relationship to the operation of natural thermal ratchets has not been resolved. In this embodiment of the invention, a spatially symmetric thermal ratchet is shown implemented with holographic optical traps. The potential energy landscape in this system consists of a large number of discrete optical tweezers, each of which acts as a symmetric potential energy well for nanometer- to micrometer-scale objects such as colloidal spheres. These wells are arranged so that colloidal spheres can diffuse freely in the interstitial spaces but are localized rapidly once they encounter a trap. A three-state thermal ratchet then requires only displaced copies of a single two-dimensional trapping pattern. Despite its simplicity, this ratchet model displays flux reversal in which the direction of motion is controlled by a balance between the rate at which particles diffuse across the landscape and the ratchet's cycling rate.
[0148] FIGS. 11( a )- 11 ( d ) present a spatially-symmetric three-state ratchet potential comprised of discrete potential wells. Flux reversal has been directly observed in comparatively few systems. Flux reversal arises as a consequence of stochastic resonance for a colloidal sphere hopping between the symmetric double-well potential of a dual optical trap. Previous larger-scale demonstrations have focused on ratcheting of magnetic flux quanta through type-II superconductors in both the quantum mechanical and classical regimes, or else have exploited the crossover from quantum mechanical to classical transport in a quantum dot array. Unlike the present implementation, these exploit spatially asymmetric potentials and take the form of rocking ratchets. A similar crossover-mediated reversal occurs for atomic clouds in symmetric optical lattices. A hydrodynamic ratchet driven by oscillatory flows through asymmetric pores also shows flux reversal. In this case, however, the force field is provided by the divergence-free flow of an incompressible fluid rather than a potential energy landscape, and so is an instance of a so-called drift ratchet. Other well known implementations of classical force-free thermal ratchets also were based on asymmetric potentials, but did not exhibit flux reversal.
[0149] FIGS. 11( a )- 11 ( d ) show the principle upon which the three-state optical thermal ratchet operates. The process starts out with a pattern of discrete optical traps, each of which can localize an object. The pattern in the initial state is schematically represented as three discrete potential energy wells, each of width σ and depth V 0 , separated by distance L. A practical trapping pattern can include a great many optical traps organized into manifolds. The first pattern of FIG. 11( a ) is extinguished after time T and replaced immediately with the second ( FIG. 11( b )), which is displaced from the first by L/3. This is repeated in the third state with an additional step of L/3 ( FIG. 11( c )), and again when the cycle is completed by returning to the first state ( FIG. 11( d )).
[0150] If the traps in a given state overlap those in the state before, a trapped particle is transported deterministically forward. Running through this cycle repeatedly transfers the object in a direction determined unambiguously by the sequence of states, and is known as optical peristalsis. The direction of motion can be reversed only by reversing the sequence.
[0151] The optical thermal ratchet differs from this in that the inter-trap separation L is substantially larger than σ. Consequently, particles trapped in the first pattern are released into a force-free region and can diffuse freely when that pattern is replaced by the second. Those particles that diffuse far enough to reach the nearest traps in the second pattern rapidly become localized. A comparable proportion of this localized fraction then can be transferred forward again once the third pattern is projected, and again when the cycle returns to the first state.
[0152] Unlike optical peristalsis, in which all particles are promoted in each cycle, the stochastic ratchet transfers only a fraction. This, however, leads to a new opportunity. Particles that miss the forward-going wave might still reach a trap on the opposite side of their starting point while the third pattern is illuminated. These particles would be transferred backward by L/3 after time 2T.
[0153] For particles of diffusivity D, the time required to diffuse the inter-trap separation is τ=L 2 /(2D). Assuming that particles begin each cycle well localized at a trap, and that the traps are well separated compared to their widths, then the probability for ratcheting forward by L/3 during the interval T is roughly P F ≈exp(−(L/3) 2 /(2DT)), while the probability of ratcheting backwards in time 2T is roughly P R ≈exp(−(L/3) 2 /(4DT)). The associated fluxes of particles then are ν F =P F L/(3T) and ν R =−P R L/(6T), with the dominant term determining the overall direction of motion. The direction of induced motion may be expected to reverse when P F ≈exp(−(L/3) 2 /(2DT)), or for example when T/τ<(18 ln 2) −1 ≈0.08.
[0154] More formally, this can be modeled as an array of optical traps in the n-th pattern as Gaussian potential wells
[0000]
V
n
(
x
)
=
∑
j
=
-
N
N
-
V
0
exp
(
-
(
x
-
j
L
-
n
L
3
)
2
2
σ
2
)
,
(
71
)
[0000] where n=0, 1, or 2, and N sets the extent of the landscape. The probability density ρ(x,t)dx for finding a Brownian particle within dx of position x at time t in state n evolves according to the master equation,
[0000] ρ( y,t+T )=∫ P n ( y,T|x, 0)ρ( x,t ) dx, (72)
[0000] characterized by the propagator
[0000] P n ( y,T|x, 0)= e L n (y)T δ( y−x ) (73)
[0000] where the Liouville operator for state n is
[0000]
L
n
(
y
)
=
D
(
∂
2
∂
y
2
-
β
∂
∂
y
V
n
′
(
y
)
)
,
(
74
)
[0155] with
[0000]
V
n
′
(
y
)
=
V
n
y
,
[0000] and where β −1 is the thermal energy scale.
[0156] The master equation for a three-state cycle is
[0000] ρ( y,t+ 3 T )=∫ P 123 ( y, 3 T|x, 0)ρ( x,t ) dx, (75)
[0000] with the three-state propagator
[0000] P 123 ( y, 3 T|x, 0)=∫ dy 1 dy 2 P 3 ( y,T|y 2 ,0) xP 2 ( y 2 ,T|y 1 ,0) P 1 ( y 1 ,T|x, 0). (76)
[0157] Because the landscape is periodic and analytic, Eq. (75) has a steady-state solution such that
[0000]
ρ
(
x
,
t
+
3
T
)
=
ρ
(
x
,
t
)
(
77
)
≡
ρ
123
(
x
)
.
(
78
)
[0158] The mean velocity of this steady-state then is given by
[0000]
v
=
∫
P
123
(
y
,
3
T
|
x
,
0
)
(
y
-
x
3
T
)
ρ
123
(
x
)
x
y
,
(
79
)
[0000] where P 123 (y,3T|x,0) is the probability for a particle originally at position x to “jump” to position y by the end of one compete cycle, (y−x)/(3T) is the velocity associated with making such a jump, and ρ 123 (x) is the fraction of the available particles actually at x at the beginning of the cycle in steady-state. This formulation is invariant with respect to cyclic permutations of the states, so that the same flux of particles would be measured at the end of each state. The average velocity ν therefore describes the time-averaged flux of particles driven by the ratchet.
[0159] FIG. 12( a ) shows numerical solutions of this system of equations for representative values of the relative inter-well separation L/σ. If the interval T between states is very short, particles are unable to keep up with the evolving potential energy landscape, and so never travel far from their initial positions; the mean velocity vanishes in this limit. The transport speed ν also vanishes as 1/T for large values of T because the induced drift becomes limited by the delay between states. If traps in consecutive patterns are close enough (L=6.5σ in FIG. 12( a )) particles jump forward at each transition with high probability, yielding a uniformly positive drift velocity. This transfer reaches its maximum efficiency for moderate cycle times, T/τ≈2√{square root over (2)}(L/σ)(βV 0 ) −1 . More widely separated traps (L=13σ in FIG. 12( a )) yield more interesting behavior. Here, particles are able to keep up with the forward-going wave for large values of T. Faster cycling, however, leads to flux reversal, characterized by negative values of ν.
[0160] FIG. 12( a ) further presents crossover from deterministic optical peristalsis at L=6.5σ to thermal ratchet behavior with flux reversal at L=13σ for a three-state cycle of Gaussian well potentials at βV 0 =8.5, σ=0.53 μm and D=0.33 μm 2 /sec. Intermediate curves are calculated for evenly spaced values of L. FIG. 12( b ) presents an image of 20×5 array of holographic optical traps at L 0 =6.7 μm. FIG. 12( c ) presents an image of colloidal silica spheres 1.53 μm in diameter interacting with the array. FIG. 12( d ) presents the rate dependence of the induced drift velocity for fixed inter-trap separation, L 0 . FIG. 12( e ) presents the separation dependence for fixed inter-state delay, T=2 sec.
[0161] As an example of operation, this thermal ratchet protocol is implemented for a sample of 1.53 μm diameter colloidal silica spheres (Bangs Laboratories, lot number 5328) dispersed in water, using potential energy landscapes created from arrays of holographic optical traps. The sample was enclosed in a hermetically sealed glass chamber roughly 40 μm thick created by bonding the edges of a coverslip to a microscope slide and was allowed to equilibrate to room temperature (21±1° C.) on the stage of a Zeiss S100TV Axiovert inverted optical microscope. A 100×NA 1.4 oil immersion SPlan Apo objective lens was used to focus the optical tweezer array into the sample and to image the spheres, whose motions were captured with an NEC TI 324A low noise monochrome CCD camera. The micrograph in FIG. 12( b ) shows the focused light from a 20×5 array of optical traps formed by a phase hologram projected with a Hamamatsu X7550 spatial light modulator. The tweezers are arranged in twenty-trap manifolds 25 μm long separated by L 0 =6.7 μm. Each trap is powered by an estimated 2.5±0.4 mW of laser light at 532 nm. The particles, which appear in the bright-field micrograph in FIG. 12( c ), are twice as dense as water and sediment to the lower glass surface, where they diffuse freely in the plane with a measured diffusion coefficient of D=0.33±0.03 μm 2 /sec, which reflects the influence of the nearby wall. Out-of-plane fluctuations were minimized by projecting the traps at the spheres' equilibrium height above the wall.
[0162] Three-state cycles of optical trapping patterns are projected in which the manifolds in FIG. 12( b ) were displaced horizontally by −L 0 /3, 0, and L 0 /3, with inter-state delay times T ranging from 0.8 sec. to 10 sec. The particles' motions were recorded as uncompressed digital video streams for analysis. Between 40 and 60 particles were in the trapping pattern during a typical run, so that roughly 40 cycles sufficed to acquire reasonable statistics under each set of conditions without complications due to collisions. Particles outside the trapping pattern are tracked to monitor their diffusion coefficients and to ensure the absence of drifts in the supporting fluid. The results plotted in FIG. 12( d ) reveal flux reversal at T/τ≈0.03. Excellent agreement with Eq. (79) is obtained for βV 0 =8.5±0.8 and a=0.53±0.01 μm.
[0163] The appearance of flux reversal as one parameter is varied implies that other parameters also should control the direction of motion. Indeed, flux reversal is obtained in FIG. 12( e ) as the inter-trap separation is varied from L=5.1 μm to 8.3 μm at fixed delay time, T=2 sec. These results also agree well with predictions of Eq. (79), with no adjustable parameters. The same effect also should arise for different populations in a heterogeneous sample with different values of D, V 0 and σ. In this case, distinct fractions can be induced to move simultaneously in opposite directions.
[0164] Such sensitivity of the transport direction to details of the dynamics also might play a role in the functioning of molecular motors such as myosin-VI whose retrograde motion on actin filaments compared with other myosins has excited much interest. This molecular motor is known to be nonprocessive; its motion involves a diffusive search of the actin filament's potential energy landscape, which nevertheless results in unidirectional hand-over-hand transport. These characteristics are consistent with the present model's timing-based flux reversal mechanism, and could provide a basis to explain how small structural differences among myosins could lead to oppositely directed transport.
E. Flux Reversal for Two-State Thermal Ratchets
[0165] Another exemplary embodiment of the present invention is presented for two state ratchets. A Brownian particle's random motions can be rectified by a periodic potential energy landscape that alternates between two states, even if both states are spatially symmetric. If the two states differ only by a discrete translation, the direction of the ratchet-driven current can be reversed by changing their relative durations. The present embodiment provides flux reversal in a symmetric two-state ratchet by tracking the motions of colloidal spheres moving through large arrays of discrete potential energy wells created with dynamic holographic optical tweezers. The model's simplicity and high degree of symmetry suggest possible applications in molecular-scale motors.
[0166] Until fairly recently, random thermal fluctuations were considered impediments to inducing motion in systems such as motors. Fluctuations can be harnessed, however, through mechanisms such as stochastic resonance and thermal ratchets, as efficient transducers of input energy into mechanical motion. Unlike conventional machines, which battle noise, molecular-scale devices that exploit these processes actually requite thermal fluctuations to operate.
[0167] The present embodiment creates thermal ratchets in which the random motions of Brownian particles are rectified by a time-varying potential energy landscape. Even when the landscape has no overall slope and thus exerts no average force, directed motion still can result from the accumulation of coordinated impulses. Most thermal ratchet models break spatiotemporal symmetry by periodically translating, tilting or otherwise modulating a spatially asymmetric landscape. Inducing a flux is almost inevitable in such systems unless they satisfy conditions of spatiotemporal symmetry or supersymmetry. Even a spatially symmetric landscape can induce a flux with appropriate driving. Unlike deterministic motors, however, the direction of motion in these systems can depend sensitively on implementation details.
[0168] A spatially symmetric three-state thermal ratchet is demonstrated for micrometer-scale colloidal particles implemented with arrays of holographic optical tweezers, each of which constitutes a discrete potential energy well. Repeatedly displacing the array first by one third of a lattice constant and then by two thirds breaks spatiotemporal symmetry in a manner that induces a flux. Somewhat surprisingly, the direction of motion depends sensitively on the duration of the states relative to the time required for a particle to diffuse the inter-trap separation. The induced flux therefore can be canceled or even reversed by varying the rate of cycling, rather than the direction. This approach builds upon the pioneering demonstration of unidirectional flux induced by a spatially asymmetric time-averaged optical ratchet, and of reversible transitions driven by stochastic resonance in a dual-trap rocking ratchet.
[0169] FIG. 13 presents a sequence of one complete cycle of a spatially-symmetric two-state ratchet potential comprised of discrete potential wells.
[0170] Here, flux induction and flux reversal is demonstrated in a symmetric two-state thermal ratchet implemented with dynamic holographic optical trap arrays. The transport mechanism for this two-state ratchet is more subtle than the previous three-state model in that the direction of motion is not easily intuited from the protocol. Its capacity for flux reversal in the absence of external loading, by contrast, can be inferred immediately by considerations of spatiotemporal symmetry. This also differs from the three-state ratchet and the rocking double-tweezer in which flux reversal results from a finely tuned balance of parameters.
[0171] FIG. 13 schematically therefore depicts how the two-state ratchet operates. Each state consists of a pattern of discrete optical traps, modeled here as Gaussian wells of width σ and depth V 0 , uniformly separated by a distance L>>σ. The first array of traps is extinguished after time T 1 and replaced immediately with a second array, which is displaced from the first by L/3. The second pattern is extinguished after time T 2 and replaced again by the first, thereby completing one cycle.
[0172] If the potential wells in the second state overlap those in the first, then trapped particles are handed back and forth between neighboring traps as the states cycle, and no motion results. This also is qualitatively different from the three-state ratchet, which deterministically transfers particles forward under comparable conditions, in a process known as optical peristalsis. The only way the symmetric two-state ratchet can induce motion is if trapped particles are released when the states change and then diffuse freely.
[0173] FIG. 14( a ) presents a displacement function ƒ(t) and FIG. 14( b ) presents equivalent tilting-ratchet driving force F(t)=−η{dot over (ƒ)}(t).
[0174] The motion of a Brownian particle in this system can be described with the one-dimensional Langevin equation
[0000] η{dot over ( x )}( t )=− V ′( x ( t )−ƒ( t ))+ξ( t ) (80)
[0000] where η is the fluid's dynamic viscosity, V(x) is the potential energy landscape, V′(x)=∂V(x)/∂x is its derivative, and ξ(t) is a delta-correlated stochastic force representing thermal noise. The potential energy landscape in our system is spatially periodic with period L,
[0000] V ( x+L )= V ( x ). (81)
[0175] The time-varying displacement of the potential energy in our two-state ratchet is described by a periodic function ƒ(t) with period T=T 1 +T 2 , which is plotted in FIG. 14( a ).
[0176] The equations describing this traveling potential ratchet can be recast into the form of a tilting ratchet, which ordinarily would be implemented by applying an oscillatory external force to objects on an otherwise fixed landscape. The appropriate coordinate transformation, y(t)=x(t)−ƒ(t), yields
[0000] η{dot over ( y )}( t )=− V ′( y ( t ))+ F ( t )+ξ( t ), (82)
[0000] where F(t)=−η{dot over (ƒ)}(t) is the effective driving force. Because ƒ(t) has a vanishing mean, the average velocity of the original problem is the same as that of the transformed tilting ratchet {dot over (x)} = {dot over (y)} , where the angle brackets imply both an ensemble average and an average over a period T.
[0177] Reimann has demonstrated that a steady-state flux, {dot over (y)} ≠0, develops in any tilting ratchet that breaks both spatiotemporal symmetry,
[0000] V ( y )= V (− y ), and − F ( t )= F ( t+T/ 2), (83)
[0000] and also spatiotemporal supersymmetry,
[0000] − V ( y )= V ( y+L/ 2), and − F ( t )= F (− t ). (84)
[0000] for any Δt. No flux results if either of Eqs. (83) or (84) is satisfied.
[0178] The optical trapping potential depicted in FIG. 13 is symmetric but not supersymmetric. Provided that F(t) violates the symmetry condition in Eq. (83), the ratchet must induce directed motion. Although F(t) is supersymmetric, as can be seen in FIG. 14( b ), it is symmetric only when T 1 =T 2 . Consequently, we expect a particle current for T 1 ≠T 2 . The zero crossing at T 1 =T 2 furthermore portends flux reversal on either side of the equality.
[0179] FIG. 15 presents steady-state drift velocity as a function of the relative dwell time, T 2 /T 1 , for βV 0 =3.04, L=5.2 μm, σ==0.80 μm, and various values of T/τ. Transport is optimized under these conditions by running the ratchet at T/τ=0.193.
[0180] The steady-state velocity is calculated for this system by solving the master equation associated with Eq. (80). The probability for a driven Brownian particle to drift from position x 0 to within dx of position x during the interval t, is given by the propagator
[0000] P ( x,t|x 0 ,0) dx=e ∫′L(x,t′)dt′ δ( x−x 0 ) dx, (85)
[0000] where the Liouville operator is
[0000]
L
(
x
,
t
)
=
D
(
∂
2
∂
x
2
+
β
∂
∂
x
V
′
(
x
,
t
)
)
,
(
86
)
[0000] and where β −1 is the thermal energy scale. The steady-state particle distribution ρ(x) is an eigenstate of the master equation
[0000] ρ( x )=∫ P ( x,t|x 0 )ρ( x 0 ) dx 0 , (87)
[0000] and the associated steady-state flux is
[0000]
v
=
∫
x
-
x
0
T
ρ
(
x
0
)
P
(
x
,
T
|
x
0
,
0
)
x
x
0
.
(
88
)
[0181] The natural length scale in this problem is L, the inter-trap spacing in either state. The natural time scale, τ=L 2 /(2D), is the time required for particles of diffusion constant D to diffuse this distance.
[0182] FIG. 15 shows how ν varies with T 2 /T 1 for various values of T/τ for experimentally accessible values of V 0 , σ, and L. As anticipated, the net drift vanishes for T 2 =T 1 . Less obviously, the induced flux is directed from each well in the longer-duration state toward the nearest well in the short-lived state. The flux falls off as 1/T in the limit of large T because the particles spend increasingly much of their time localized in traps. It also diminishes for short T because the particles cannot keep up with the landscape's evolution. In between, the range of fluxes can be tuned with T.
[0183] FIG. 16( a ) presents an image of 5×20 array of holographic optical traps at L=5.2 μm. FIG. 16( b ) presents a video micrograph of colloidal silica spheres 1.53 μm in diameter trapped in the middle row of the array at the start of an experimental run. FIGS. 16( c ) and 16 ( d ) present the time evolution of the measured probability density for finding particles at T 2 =0.8 sec and T 2 =8.6 sec, respectively, with T 1 fixed at 3 sec. FIG. 16( e ) presents the time evolution of the particles' mean position calculated from the distribution functions in 16 ( c ) and 16 ( d ). The slopes of linear fits provide estimates for the induced drift velocity, which can be compared with displacements calculated with Eq. (89) for βV 0 =2.75, and σ=0.65 μm FIG. 16( f ) presents the measured drift speed as a function of relative dwell time T 2 /T 1 , compared with predictions of Eq. (88).
[0184] As an example, this method is implemented for a sample of 1.53 μm diameter colloidal silica spheres (Bangs Laboratories, lot number 5328) dispersed in water, using potential energy landscapes created from arrays of holographic optical traps. The sample was enclosed in a hermetically sealed glass chamber roughly 40 μm thick created by bonding the edges of a coverslip to a microscope slide, and was allowed to equilibrate to room temperature (21±1° C.) on the stage of a Zeiss S100 2TV Axiovert inverted optical microscope. A 100×NA 1.4 oil immersion SPlan Apo objective lens was used to focus the optical tweezer array into the sample and to image the spheres, whose motions were captured with an NEC TI 324A low noise monochrome CCD camera. The micrograph in FIG. 16( a ) shows the focused light from a 5×20 array of optical traps formed by a phase hologram projected with a Hamamatsu X7550 spatial light modulator [17]. The tweezers are arranged in twenty-trap manifolds 37 μm long separated by L=5.2 μm. Each trap is powered by an estimated 2.5±0.4 mW of laser light at 532 nm. The particles, which appear in the bright-field micrograph in FIG. 16( b ), are twice as dense as water and sediment to the lower glass surface, where they diffuse freely in the plane with a measured diffusion coefficient of D=0.33±0.03 μm 2 /sec. This establishes the characteristic time scale for the system of τ=39.4 sec, which is quite reasonable for digital video microscopy studies. Out-of-plane fluctuations were minimized by focusing the traps at the spheres' equilibrium height above the wall.
[0185] Two-state cycles of optical trapping patterns are projected in which the manifolds in FIG. 16( a ) were alternately displaced in the spheres' equilibrium plane by L/3, with the duration of the first state fixed at T 1 =3 sec and T 2 ranging from 0.8 sec to 14.7 sec. To measure the flux induced by this cycling potential energy landscape for one value of T 2 , we first gathered roughly two dozen particles in the middle row of traps in state 1 , as shown in FIG. 16( b ), and then projected up to one hundred periods of two-state cycles. The particles' motions were recorded as uncompressed digital video streams for analysis. Their time-resolved trajectories then were averaged over the transverse direction into the probability density, ρ(x,t)Δx, for finding particles within Δx=0.13 μm of position x after time t. We also tracked particles outside the trapping pattern to monitor their diffusion coefficients and to ensure the absence of drifts in the supporting fluid. Starting from this well-controlled initial condition resolves any uncertainties arising from the evolution of nominally random initial conditions.
[0186] FIGS. 16( c ) and 16 ( d ) show the spatially-resolved time evolution of ρ(x,t) for T 2 =0.8 sec<T 1 and T 2 =8.6 sec>T 1 In both cases, the particles spend most of their time localized in traps, visible here as bright stripes, occasionally using the shorter-lived traps as springboards to neighboring wells in the longer-lived state. The mean particle position (x(t) =∫xρ(x,t)dx advances as the particles make these jumps, with the associated results plotted in FIG. 16( e ).
[0187] The speed with which an initially localized state, ρ(x,0)≈δ(x), advances differs from the steady-state speed plotted, in FIG. 15 , but still can be calculated as the first moment of the propagator,
[0000] x ( t ) =∫ yP ( y,t |0,0) dy. (89)
[0000] Numerical analysis reveals a nearly constant mean speed that agrees quite closely with the steady-state speed from Eq. (88).
[0188] Fitting traces such as those in FIG. 16( e ) to linear trends provides estimates for the ratchet-induced flux, which are plotted in FIG. 16( f ). The solid curve in FIG. 16( f ) shows excellent agreement with predictions of Eq. (89) for βV 0 =2.75±0.5 and σ=0.65±0.05 μm.
[0189] The two-state ratchet method presented herein therefore involves updating the optical intensity pattern to translate the physical landscape. However, the same principles can be applied to systems in which the landscape remains fixed and the object undergoes cyclic transitions between two states. FIG. 17 depicts a model for an active two-state walker on a fixed physical landscape that is inspired by the biologically relevant transport of single myosin head groups along actin filaments. The walker consists of a head group that interacts with localized potential energy wells periodically distributed on the landscape. It also is attached to a lever arm that uses an external energy source to translate the head group by a distance somewhat smaller than the inter-well separation. The other end of the lever arm is connected to the payload, whose viscous drag would provide the leverage necessary to translate the head group between the extended and retracted states. Switching between the walker's two states is equivalent to the two-state translation of the potential energy landscape in our experiments, and thus would have the effect of translating the walker in the direction of the shorter-lived state. A similar model in which a two-state walker traverses a spatially asymmetric potential energy landscape yields deterministic motion at higher efficiency than the present model. It does not, however, allow for reversibility. The length of the lever arm and the diffusivity of the motor's body and payload determine the ratio T/τ and thus the motor's efficiency. The two-state ratchet's direction does not depend on T/τ, however, even under heavy loading. This differs from the three-state ratchet, in which T/τ also controls the direction of motion. This protocol could be used in the design of mesoscopic motors based on synthetic macromolecules or microelectromechanical systems (MEMS).
[0190] The foregoing description of embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the present invention. The embodiments were chosen and described in order to explain the principles of the present invention and its practical application to enable one skilled in the art to utilize the present invention in various embodiments and with various modifications as are suited to the particular use contemplated.
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A method for manipulating a plurality of objects. The method includes the steps of providing a shaping source, applying the shaping source to create a spatially symmetric potential energy landscape, applying the potential energy landscape to a plurality of objects, thereby trapping at least a portion of the plurality of objects in the potential energy landscape, spatially moving the potential energy landscape to manipulate the plurality of objects; and extinguishing the potential energy landscape, thereby causing the plurality of objects to move freely when the potential energy landscape is extinguished.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates in general to an improved architecture for conditioning air flow inside data storage devices and, in particular, to an improved system, method, and apparatus for breaking up large-scale eddies and straightening air flow inside rotary disk storage devices.
2. Description of the Related Art
Data access and storage systems generally comprise one or more storage devices that store data on magnetic or optical storage media. For example, a magnetic storage device is known as a direct access storage device (DASD) or a hard disk drive (HDD) and includes one or more disks and a disk controller to manage local operations concerning the disks. The hard disks themselves are usually made of aluminum alloy or a mixture of glass and ceramic, and are covered with a magnetic coating. Typically, one to five disks are stacked vertically on a common spindle that is turned by a disk drive motor at several thousand revolutions per minute (rpm). Hard disk drives have several different typical standard sizes or formats, including server, desktop, mobile (2.5 and 1.8 inches) and micro drive.
A typical HDD also uses an actuator assembly to move magnetic read/write heads to the desired location on the rotating disk so as to write information to or read data from that location. Within most HDDs, the magnetic read/write head is mounted on a slider. A slider generally serves to mechanically support the head and any electrical connections between the head and the rest of the disk drive system. The slider is aerodynamically shaped to glide over moving air in order to maintain a uniform distance from the surface of the rotating disk, thereby preventing the head from undesirably contacting the disk.
The head and arm assembly is linearly or pivotally moved utilizing a magnet/coil structure that is often called a voice coil motor (VCM). The stator of a VCM is mounted to a base plate or casting on which the spindle is also mounted. The base casting with its spindle, actuator VCM, and internal filtration system is then enclosed with a cover and seal assembly to ensure that no contaminants can enter and adversely affect the reliability of the slider flying over the disk. When current is fed to the motor, the VCM develops force or torque that is substantially proportional to the applied current. The arm acceleration is therefore substantially proportional to the magnitude of the current. As the read/write head approaches a desired track, a reverse polarity signal is applied to the actuator, causing the signal to act as a brake, and ideally causing the read/write head to stop and settle directly over the desired track.
One of the major hurdles in hard disk drive (HDD) development is track misregistration (TMR). TMR is the term used for measuring data errors while a HDD writes data to and reads data from the disks. One of the major contributors to TMR is flow-induced vibration. Flow-induced vibration is caused by turbulent flow within the HDD. The nature of the flow inside a HDD is characterized by the Reynolds number, which is defined as the product of a characteristic speed in the drive (such as the speed at the outer diameter of the disk), and a characteristic dimension (such as the disk diameter or, for some purposes, disk spacing). In general, the higher the Reynolds number, the greater the propensity of the flow to be turbulent.
Due to the high rotational speed of the disks and the complex geometries of the HDD components, the flow pattern inside a HDD is inherently unstable and non-uniform in space and time. The combination of flow fluctuations and component vibrations are commonly referred to as “flutter” in the HDD literature. The more precise terms “disk flutter” and “arm flutter” refer to buffeting of the disk and arm, respectively, by the air flow. Unlike true flutter, the effect of the vibrations in HDDs on the flow field is usually negligible. Even small arm and disk vibrations (at sufficiently large frequencies, e.g., 10 kHz and higher), challenge the ability of the HDD servo system to precisely follow a track on the disk.
Since the forcing function of vibrations is directly related to flow fluctuations, it is highly desirable to reduce any fluctuating variation in the flow structures of air between both co-rotating disks and single rotating disks. Thus, a system, method, and apparatus for improving the architecture for conditioning air flow inside data storage devices is needed.
SUMMARY OF THE INVENTION
One embodiment of a system, method, and apparatus of the present invention attempts to apply several techniques to solve track misregistration (TMR) problems in hard disk drives (HDD). Some of the solutions presented herein are related to straightening airflows in wind tunnel applications. Several key components for breaking up large-scale eddies or straightening HDD air flows are honeycomb structures, woven wire screens, and guide vanes or holes. The flow-conditioning solutions presented in the present application reduce the turbulence intensity throughout the HDD to reduce TMR. These solutions achieve these goals while minimizing increases in the running torque needed to overcome their inherent rotational drag.
Three of the solutions may be categorized as large-eddy break-up (LEBU) devices. By installing these devices inside an HDD, the turbulent energy generated by the devices is confined to a range of smaller eddies that are more easily dissipated. The LEBU devices are positioned in the flow stream between the disks. The passages in the devices are aligned tangentially along a framing structure. The framing structure extends radially between the disks such that the various sets of passages are interleaved relative to the disk stack. Moreover, the LEBU devices can be placed as a single unit or multiple units in series, depending upon the application.
Another solution affects the stability of the HDD flow and enables the flow to follow complex geometries and regions with adverse pressure gradients (i.e., increasing pressure in the direction of flow) without flow separation. Separated regions are a major source of flow fluctuations when the Reynolds number is sufficiently large. The latter is true for typical prior art HDD configurations. Suction inhibits turbulent mixing between the Ekman layers spun off the disk and their return flow. Reduced mixing leads to a reduction in the aerodynamic torque needed to spin the disk pack.
The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the present invention, taken in conjunction with the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the features and advantages of the invention, as well as others which will become apparent are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the drawings illustrate only an embodiment of the invention and therefore are not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
FIG. 1 is a top plan view of one embodiment of a disk drive constructed in accordance with the present invention.
FIG. 2 is a top plan view of another embodiment of a disk drive constructed in accordance with the present invention.
FIG. 3 is a sectional side view of one embodiment of a interleaf structure taken along the line 3 - 3 of FIG. 2 .
FIG. 4 is a sectional side view of an alternate embodiment of the interleaf structure of FIG. 3 .
FIG. 5 is a sectional side view of another alternate embodiment of the interleaf structure of FIG. 3 .
FIG. 6 is a sectional side view of yet another alternate embodiment of the interleaf structure of FIG. 3 .
FIG. 7 is a sectional side view of still another alternate embodiment of the interleaf structure of FIG. 3 .
FIG. 8 is a partial isometric view of one embodiment of a boundary layer device for a disk drive enclosure.
FIG. 9 is a partial isometric view of an alternate embodiment of the boundary layer device of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , one embodiment of a system, method, and apparatus for reducing track misregistration in disk drives is shown. This embodiment employs an information storage system comprising a magnetic hard disk file or drive 111 for a computer system. Drive 111 has an outer housing or base 113 (e.g., an enclosure) containing at least one magnetic disk 115 . Disk 115 is rotated by a spindle motor assembly having a central drive hub 117 . An actuator 121 comprises a plurality of parallel actuator arms 125 (one shown) in the form of a comb that is pivotally mounted to base 113 about a pivot assembly 123 . A controller 119 is also mounted to base 113 for selectively moving the comb of arms 125 relative to disk 115 .
In the embodiment shown, each arm 125 has extending from it at least one cantilevered load beam and suspension 127 . A magnetic read/write transducer or head is mounted on a slider 129 and secured to a flexure that is flexibly mounted to each suspension 127 . The read/write heads magnetically read data from and/or magnetically write data to disk 115 . The level of integration called the head gimbal assembly is head and the slider 129 , which are mounted on suspension 127 . The slider 129 is usually bonded to the end of suspension 127 .
Suspensions 127 have a spring-like quality, which biases or urges the air bearing surface of the slider 129 against the disk 115 to enable the creation of the air bearing film between the slider 129 and disk surface. A voice coil 133 housed within a conventional voice coil motor magnet assembly is also mounted to arms 125 opposite the head gimbal assemblies. Movement of the actuator 121 (indicated by arrow 135 ) by controller 119 moves the head gimbal assemblies radially across tracks on the disk 115 until the heads settle on their respective target tracks. The head gimbal assemblies operate in a conventional manner and always move in unison with one another, unless drive 111 uses multiple independent actuators (not shown) wherein the arms can move independently of one another.
Referring now to FIGS. 1 and 2 , drive 111 further comprises a flow-conditioning device 141 that is mounted to the enclosure 113 adjacent to the disk 115 . The flow-conditioning device 141 comprises one or more “flow straighteners” that may be either symmetrically arrayed or asymmetrically about the disk 115 , depending upon the application. FIG. 2 illustrates the symmetrical arrangement. Each flow-conditioning device 141 comprises a foundation or support post 145 that is mounted to the enclosure 113 . As shown in FIG. 3 , one embodiment of support post 145 is mounted to and extends between both portions of the enclosure 113 : base plate 113 a and top cover 113 b.
The flow-conditioning device 141 includes at least one projection or finger 143 (e.g., five shown for four disks 115 in FIG. 3 ) having passages 147 . The fingers 143 extend radially with respect to the disks 115 and their axis 116 , and parallel to the surface 118 of the disks 115 . When two or more fingers 143 are used, the adjacent fingers 143 define a slot 144 that closely receives the two parallel surfaces of the disk 115 . The fingers 143 originate at the support post 145 and preferably extend to or near the disk hub 117 . However, there is no contact between any portion of the flow-conditioning device 141 and the disks 115 .
Each finger 143 comprises a small, generally rectangular frame having a plurality of the passages 147 that permit air flow to move all the way through the finger 143 . The passages 147 are formed in the finger 143 in directions that are axially and radially transverse (e.g., perpendicular) with respect to the disks 115 . Each of the fingers 143 has the passages 147 to reduce air flow turbulence intensity and track misregistration.
The fingers 143 are positioned in the air flow stream generated by the disks 115 so that, as the disks 115 rotate, the passages 147 are aligned with the air flow stream and reduce an air flow turbulence intensity and track misregistration between the heads on the sliders 129 and the read/write tracks on the disks 115 . The turbulent energy generated by the flow-conditioning device(s) 141 is confined to a range of smaller eddies that are more easily dissipated within the disk drive 111 than prior art large eddies. Each finger 143 has an angular or arcuate width in a range of approximately 5 degrees or less. Each finger 143 also can be configured to have a constant width along the radial direction of the disk 115 .
As shown in FIGS. 3-7 , the passages 147 may comprise many different configurations or combinations thereof. For example, in FIG. 3 , the passages 147 are configured in a honeycomb structure 151 having a tight array of one or more hexagonal feature(s) that extend across the entire face of the fingers 143 . In one embodiment, the passages 147 (honeycomb cell size) are on the order of five times smaller than the axial disk spacing. In addition, the fingers 143 may have an arcuate width that is approximately equal to said axial distance minus a mechanical clearance on the order of 0.5 mm.
In another embodiment ( FIG. 4 ), the passages are formed from wire screen walls 153 , which may be woven, mounted on a framing structure. The wire screen dimensions are dictated by the size of the disk diameter and spacing. Typically, the wire screen walls 153 comprise at least two or three passages across the vertical direction. In one version, the wire screen walls 153 have a thickness on the order of 0.1 mm.
In FIG. 5 , the passages comprise sets of guide vanes 155 that extend axially with respect to the disk 115 . In the embodiment shown, the guide vanes 155 are grouped in small sets of three that radially offset from each other. The individual vanes in guide vanes 155 are parallel to each other. Other guide vane configurations are possible, including those of the slanted type. The guide vanes have a thickness that is sufficient to ensure mechanical stability and ruggedness, which may be on the order of 0.3 mm.
Alternatively, the passages may be formed by cylindrical tubes 157 , as shown in FIG. 6 . The cylindrical tubes 157 may comprise many different configurations, such as side-by-side in a flat array having a single row of the axially parallel cylindrical tubes 157 . In another embodiment ( FIG. 7 ), the cylindrical tubes 159 form a plurality (two shown) of parallel rows that are configured in an alternating pattern of upper and lower positions.
Referring now to FIG. 8 , an inner wall of the enclosure 113 may be configured with a boundary layer device 161 . The boundary layer device 161 is designed to manipulate the air flow inside the disk drive 111 to provide aerodynamic and acoustic damping that promote viscous dissipation of turbulent fluctuations.
The boundary layer device may comprise many different forms. For example, in FIG. 8 , a suction plenum 163 having an array of suction apertures 165 is shown. The apertures 165 may comprise slots, holes, and/or combinations thereof, and are used to evacuate air flow from the interior of the disk drive 111 into the suction plenum 163 . The air flow (see arrows 167 ) is then reintroduced into the interior of the disk drive 111 at a suitable location, such as at perforations 169 in hub 117 (for clarity, disks 115 are not shown). Moreover, the suction air also may be passed through an air filter 171 before being reintroduced into the pack of disks 115 .
An alternative embodiment of the boundary layer device is shown in FIG. 9 as a lining of cavities 173 on the inner wall of enclosure 113 . In one version, the cavities 173 comprise a honeycomb of hexagonal walls 175 , each of which is perforated by a small orifice 177 . Collectively, these cavities 173 form a close-packed array of Helmholtz resonators. Because these resonators can be tuned, they are particularly effective in suppressing narrow-band turbulence fluctuations. In particular, the Helmholtz resonators may be tuned to act as acoustic notch filters or certain prominent frequencies in the file. For example, one such frequency is the vortex shedding frequency associated with the actuator arm. In addition, the cavities may comprise closed and open cell acoustic foam.
The present invention also comprises a method of reducing track misregistration in a disk drive. In one embodiment ( FIG. 1 ), the method comprises providing a disk drive 111 having an enclosure 113 , a disk 115 having a surface 118 with tracks, and an actuator 121 having a head for reading from and writing to the tracks. The method further comprises positioning a flow-conditioning device 141 ( FIG. 3 ) adjacent to the surface 118 of the disk 115 , rotating the disk 115 to generate an air flow, flowing the air flow through passages 147 in the flow-conditioning device 141 , and thereby reducing air flow turbulence intensity and track misregistration between the head and the tracks on the disk 115 .
The method also may comprise positioning the disk 115 in an elongated slot 144 in the flow-conditioning device 141 . The method may further comprise orienting the passages 147 at axially and radially transverse positions with respect to the disk 115 , and forming the passages in a configuration selected from the group consisting of: a honeycomb structure ( FIG. 3 ), wire screen walls ( FIG. 4 ), guide vanes ( FIG. 5 ), and cylindrical tubes ( FIGS. 6 and 7 ). In another embodiment, the method may further comprise forming a symmetrical array ( FIG. 2 ) of the flow-conditioning devices 141 about the disk 115 .
Alternatively, or in combination with any of the foregoing steps of the method, the method may further comprise forming a boundary layer device 161 ( FIGS. 8 and 9 ) on an inner surface of the enclosure 113 , and manipulating the air flow inside the disk drive 111 with the boundary layer device 161 to provide aerodynamic and acoustic damping that promote viscous dissipation of turbulent fluctuations. The method may comprise evacuating air flow from an interior of the disk drive 111 into a suction plenum 163 ( FIG. 8 ), and reintroducing the air flow into the disk drive 111 . In addition, the method may comprise configuring the boundary layer device as a lining of walled cavities 173 ( FIG. 9 ), each having a small orifice 177 in communication with the interior of the disk drive 111 .
The present invention has several advantages, including the ability to reduce TMR problems in hard disk drives HDDs. These solutions break up large-scale eddies, straighten air flows, and manipulate the boundary layers. As a result, the turbulence intensity is reduced throughout the HDD to reduce TMR while minimizing increases in the running torque needed to overcome rotational drag. The turbulent energy generated by the devices is confined to a range of smaller eddies that are more easily dissipated. The LEBU devices can be used individually or as multiple units in series.
The present invention also enables the flow to follow complex geometries without flow separation. Suction inhibits turbulent mixing between the Ekman layers spun off the disk and their return flow. Reduced mixing leads to a reduction in the aerodynamic torque needed to spin the disk pack. In addition, turbulent fluctuations are dampened via the dissipation generated by the special linings, some of which can be tuned to suppress narrow-band fluctuations. The application of these special linings along the interior walls of the HDD provide aerodynamic and acoustic damping. In particular, the Helmholtz resonators may be tuned to act as acoustic notch filters or certain prominent frequencies in the file.
While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.
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A system, method, and apparatus for solving flow-induced track misregistration (TMR) problems in hard disk drives (HDD) are directed to breaking up large-scale eddies, and straightening air flows with honeycomb structures, woven wire screens, and guide vanes or holes. In addition, boundary layer manipulation techniques are applied to the airflow in the HDD, such as boundary layer suction with slots or holes, and wall damping techniques, such as an open honeycomb seal and Helmholtz resonators. These flow-conditioning solutions reduce the turbulence intensity throughout the HDD to reduce TMR. These solutions achieve these goals while minimizing increases in the running torque needed to overcome their inherent rotational drag.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application represents a divisional application of and claims priority to U.S. patent application Ser. No. 14/188,727 entitled “METHOD AND APPARATUS FOR ROUTING UTILITIES IN A REFRIGERATOR” filed Feb. 25, 2014, currently allowed, which is a divisional application of and claims priority to U.S. patent application Ser. No. 12/732,710 entitled “METHOD AND APPARATUS FOR ROUTING UTILITIES IN A REFRIGERATOR” filed Mar. 26, 2010, now U.S. Pat. No. 8,690,273.
BACKGROUND OF THE INVENTION
[0002] Refrigerators are generally constructed of an outer shell, a liner defining a fresh food or freezer compartment, and an insulating layer between the shell and liner. The liner encloses all but one side of the fresh food compartment and a door, drawer, or other movable surface encloses the remaining side. The liner is typically designed to define separate compartments for the freezer and fresh food compartments.
[0003] The size of the liner, and therefore the space available is also constrained. The shell of the refrigerator is generally limited in size by industry standards, usually 32-36 inches in width, 23-29 inches in depth, and 60-84 inches in height. Sufficient insulation to keep the refrigerated and freezer compartments at an appropriate temperature also must be installed. This amount will vary by the type of insulation used, desired efficiency, air flow, and other factors. These conditions therefore limit the available space within the liner as well as the available space between the liner and shell.
[0004] Older model refrigerators only required power for a compressor to provide cooling to the fresh food and freezer compartments and therefore had fairly simple wiring requirements. Modern refrigerators route electrical wires throughout the interior of the appliance in order to control and power a variety of functions and features. Recent consumer demand for more features requires more complicated power distribution; these features include in-door ice and water dispensing, separately cooled compartments, a variety of lighting arrangements, and air circulating fans.
[0005] In order to service these demands, wire harnesses are installed between the outer shell of a refrigerator and the inner liner, passing through the insulation separating the two. One or more wiring harnesses transfers power from the input or source to a controller which distributes wire throughout the refrigerator. Additional wire harnesses from the controller to the various components generally carry one or two types of electrical current: high voltage and/or low voltage.
[0006] High voltage current is used for powering components. For example, a compressor requires a certain amount of power to operate. A wiring harnesses providing power to the compressor therefore must be sized to compensate for the amount of power required and be routed so that heating of the electrical components does not cause a fire or otherwise damage the insulation or liner.
[0007] In contrast, low voltage current is used for transferring signals between components. For example, when ice is desired from a digital ice dispenser, it is necessary to send a signal to the ice dispenser to dispense ice. The signal may take several forms, a pulse-modulated signal, amplitude or frequency modulation of a sinusoidal wave, impulse signal, or other means of electronic communication. The ice dispensing is typically performed through the use of an auger located within an ice storage bucket. A low voltage signal is sent from the control panel of the ice dispenser to the auger, indicating that the auger should be rotated to deliver ice. It is not necessary for the wire carrying this signal to be sized to the same gage as the high voltage current wires; therefore these wires can be routed more easily in narrow spaces.
[0008] Because some wiring harnesses are composed of both high and low voltage wires, the wires are generally bundled together and routed as an individual, considerably larger, strand.
[0009] Additionally, in efforts to obtain more interior space in fresh food and/or freezer compartments, components are being reduced in size and positioned in increasingly small areas. For example, in some of Assignee's products, the icemaker has been relocated to a position above the fresh food compartment while storage of ice has been relocated to the door, providing more shelf space within the body of the refrigerated compartment for storage of food or other products.
[0010] In relocating the icemaker to a position above the fresh food compartment, the amount of available space has further limited by the direction the wires need to be routed. Power supplies, converters, and controllers are located along the refrigerator door or in the body. Wires must therefore be run along the top of the refrigerator, between the shell and interior liner, before passing through the liner to the icemaker assembly. The wires must then be routed in the ice making compartment to the various components located therein.
[0011] The liner of a refrigerator is relatively thin, and therefore openings in the liner tend to have a sharp edge. Therefore, a grommet with a rounded edge and soft or otherwise protected opening is inserted into the opening to protect the wires from damage. In some cases, the grommet is integrally molded to the wires, allowing the grommet to be sized to fit the wires exactly.
[0012] In one circumstance, narrow routing requires the wiring harness to be routed in a first direction, pass through the insulation and inner liner, and then be turned 180 degrees to return from the same direction they approached.
[0013] Therefore, there has been recognized a need in the art for a grommet which allows for routing wires 180 degrees as they pass through the liner of a refrigerator.
[0014] There has been recognized a further need in the art for a method of routing wires 180 degrees within a refrigerator to avoid damage to the wires from sharp edges.
[0015] There has been recognized a further need in the art for a refrigerator with narrow openings for routing wires and attendant apparatus for accomplishing this result.
[0016] These objections and others readily apparent from the following description are sought to be accomplished by the present invention.
[0017] Other routing considerations also present persistent problems in refrigerator appliances. It is the intention of this disclosure to anticipate these problems and present solutions.
[0018] One common routing issue is transferring utilities, including electricity and water, between the refrigerator cabinet and the door of the refrigerator. With door-mounted water and ice dispensers, water, electrical signals and power must be transferred to and from the door mounted dispenser. Various products and methods of routing utilities through the door have been proposed, and the present disclosure seeks to improve the existing state of the art by presenting a novel and useful apparatus and method for routing utilities through the hinge between the refrigerator cabinet and door.
[0019] The routing of utilities from the door to the refrigerator is of particular concern because of the movement between the two components. The refrigerator door pivots about the hinge and therefore utilities routed through the hinge must be routed so that the door is not constrained from opening, nor are the lines pinched or severed in any way due to continuous and repeated openings of the door. It would therefore be preferable to have the utilities mounted through the hinge, thereby avoiding the need to provide slack in the utilities for the opening or closing of the door.
[0020] Therefore, there is recognized a need in the art for an improved method for routing utilities through the hinge between the refrigerator and door.
BRIEF SUMMARY OF THE INVENTION
[0021] Described herein is an improved wire routing apparatus. According to one embodiment, a grommet comprises a body integrally molded to a wire, the body for mounting in an appliance and having a first face into which the wire enters and a second face from which the wire exits, thereby causing the wire to be reversed 180 degrees as it passes through the grommet.
[0022] According to a second embodiment, a wire routing hinge comprises a mounting portion and a cylindrical extension, the mounting portion being attached to a refrigerator body and the cylindrical extension providing a pivot point about which the door of the refrigerator may rotate. The cylindrical extension is hollow, thereby allowing utility lines to pass through, and further includes a cutout allowing utility lines to exit from the hollow cylindrical extension.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1A shows a refrigerator according to one embodiment of the invention.
[0024] FIG. 1B shows the refrigerator with the doors open demonstrating the location of the ice maker.
[0025] FIG. 2 shows a side view of the grommet with wires passing through.
[0026] FIG. 3 shows the grommet positioned within the refrigerated cabinet.
[0027] FIG. 4 shows a perspective view of the grommet with wires passing through.
[0028] FIG. 5 shows a side cutaway view of the grommet according to one embodiment.
[0029] FIG. 6 shows a top view of the hinge of the refrigerator.
[0030] FIG. 7 shows a cutaway side view of the hinge of the refrigerator.
[0031] FIG. 8 shows a perspective view of the hinge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The invention will now be described in detail according to the preferred embodiment with reference to the attached figures where numerals relate to their like in the following description.
[0033] A refrigerator is generally shown in FIG. 1A . In the preferred embodiment, the grommet is for use in a bottom mount freezer with either a single door or French doors (shown). It is also possible that the grommet may find utility in a side-by-side or top-mounted freezer. It should also be appreciated that the present invention may be used in a variety of refrigerators and in any context. While the grommet is generally shown inside the refrigerator between the liner and insulation, those skilled in the art will recognize that a grommet may be put to a variety of other uses.
[0034] FIG. 1B shows the refrigerator with the doors open, demonstrating the arrangement of the interior of the refrigerator. As shown, the refrigerator has a fresh food compartment and a freezer compartment. Adjacent to the top of the fresh food compartment and abutting the top of the liner is an ice making compartment which houses an ice mold, impingement fan, light, water storage, and associated valves and solenoids for controlling water flow. The ice making compartment is separated from the fresh food compartment by a cover securing and positioning these various components.
[0035] FIG. 2 is a perspective view of the grommet showing the wires present. The grommet generally consists of a mounting body with wire guides on opposite sides of the body.
[0036] The mounting body of the grommet comprises a top face, a bottom face, and a deformable seal between the two faces. The grommet may be formed of flexible or rigid materials. According to the preferred embodiment, the bottom face is generally rectangular and has tabs extending from the edges of the rectangle. When the lower face of the grommet is pushed into the opening in the liner, these tabs deform or collapse, allowing the grommet to pass through the opening. Once through, the tabs reform to their original dimensions and the grommet is secured in place. This allows an installer to easily snap the grommet in place. In this arrangement, it is preferred that the seal is either non-deformable or the top face is larger than the opening in the liner.
[0037] The grommet is typically installed so that the bottom face is more aesthetically pleasing, and therefore the grommet is installed with the bottom face inside the refrigerator. The only way therefore to remove the grommet would be to remove the refrigerator shell. It may also be preferable to install the grommet so that it may be removed from within the refrigerator, for example if there is a need to repair or replace wires passing through the grommet. This may be accomplished by either installing the same grommet described above in an opposing orientation, or the grommet may have an alternative design.
[0038] One type of design which may allow the grommet to be installed and removed from within the refrigerator is to design the bottom face to be slightly larger than the opening into which the grommet is inserted. The top face would then be sized so that it is slightly smaller than the opening, allowing the grommet to pass through. The deformable seal about the perimeter of the grommet should be deformed as the grommet is pushed through the opening, but reform once the seal is passed through. This deformable seal will provide resistance to the grommet working its way out of the opening on its own.
[0039] The grommet may also be fashioned in multiple parts or rigid materials. For example, the grommet may consist of two ninety-degree components which are joined at the opening in the liner. One of the components is installed from one side of the opening and the other component is installed from the other side of the opening. Such an arrangement can be formed entirely of rigid materials as it would not require passing a component larger than the opening through the opening.
[0040] The grommet is further shown in FIG. 4 . As shown in this drawing, the top and bottom surfaces of the mounting body each include a wire routing element. Each wire routing element is designed to route wires 90 degrees, for a total of 180 degrees.
[0041] According to the preferred embodiment, the 180 degree grommet is formed of deformable material, such as rubber or an elastic plastic material. It is preferred that the wires are first formed in the arrangement as shown. The wires are then placed into a mold which forms the overall shape of the finished grommet. The deformable material is then passed into the mold, encircling the wires and filling the mold completely. Once the deformable material has set, the mold is opened and the finished grommet may be withdrawn. The wires are therefore set into the grommet and cannot be moved or accidentally slip back through the mold, as may be the case with open-channel grommets. The arrangement of molding the wires directly within the grommet also saves time routing the wires through the grommet and reduces the chance for error.
[0042] The grommet may also be formed without the wires being integrally molded to the product. For example, the grommet may be formed with an open channel passing from a surface on the top wire routing element, through the mounting body, and exiting through a similarly facing surface in the bottom wire routing element. This channel allows a wire to be inserted through the surface of the top wire routing element, through the grommet, and exit in an opposing direction from the bottom wire routing element. This arrangement further allows variations of wires to be inserted through the grommet without fixing the number or quality of wires passing through.
[0043] The routing of the wires 32 through the grommet 30 has been generally shown in FIG. 5 . This shows how the wires are arranged within the grommet to avoid being tangled or damaged by the sharp turn about the cutout in the liner.
[0044] A number of other variations on the invention may be used without departing from the intended scope of the invention. For example, the grommet may be used between fresh food and freezer compartments. Alternatively, the grommet may be used in an environment intended to be watertight, and therefore have a seal designed to be water tight. This may require additional caulking or epoxy about the sealing surface of the grommet. The grommet has also been shown and described as generally rectangular, but it is anticipated that the grommet may be circular, oblong, square, or any other shape. The grommet has also been shown to be used in a refrigerator, however it should be appreciated to those skilled in the art that the grommet may be used outside of the refrigerator context and used more broadly.
[0045] Further described by this invention is an improved utility routing hinge 60 as shown in FIGS. 6-8 . This improved utility routing hinge 60 is useful between the fresh food compartment 16 and door, shown in FIG. 6 . The hinge 60 generally consists of a mounting bracket 62 and a cylindrical extension 64 which acts as a hinge pin. The mounting bracket 62 has a plurality of mounting holes 66 positioned thereon, the mounting holes 66 for securing the hinge 60 to the refrigerator cabinet 16 .
[0046] The cylindrical extension 64 is generally hollow, allowing electrical 72 and water 74 conduits to pass through. Near the point where the cylindrical extension 64 and mounting bracket 62 join is a cutout 70 through the wall of the cylindrical extension 64 . This cutout 70 allows the electrical 72 and wire conduits 74 to pass out of the hollow interior of the cylindrical extension and pass to the refrigerator, as shown in FIG. 7 .
[0047] This cylindrical extension 64 has the additional benefit of providing a pivot point about which the refrigerator door can rotate. By passing utilities such as water and electricity through the hinge between the door and refrigerator cabinet, the distance traversed by the utility lines 72 , 74 between the door mounted dispenser and the connection point in the refrigerator is a consistent distance as the door is opened. With this benefit, it is not necessary to include extra lengths of wires 72 or water lines 74 to account for the changing distance.
[0048] In use, the improved hinge is preferably attached to the refrigerator cabinet 16 by means of the mounting bracket 62 and fasteners through the mounting holes 66 . These fasteners may be screws, adhesives, pins, or any other fastening apparatus commonly known to those in the art. The hinge 60 may also be integrally formed to the shell, liner, or some other component of the refrigerator.
[0049] The cylindrical extension 64 is aligned with the door and provides a pivot point about which the door rotates. A complimentary cylinder or other pivot point supports the bottom of the door. Utilities, preferably electrical wires 72 and water conduits 74 are routed from the door, through the center of the cylindrical extension 64 , and pass through the cutout 70 . These utilities then pass between the first 76 and second 78 legs of the cylindrical extension 64 and are connected to the water and electrical systems of the refrigerator. The first 76 and second 78 legs are preferably spaced apart to provide access to the utilities as shown in FIG. 6 . However, it should be appreciated that the mounting plate 62 may be a single piece rather than a pair of legs.
[0050] The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. From the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives.
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Disclosed in this application is a u-shaped grommet for use in a refrigerator. The grommet is fixed so as to allow wires to be routed towards an opening in the liner of the refrigerator, pass through the opening in the liner, and exit the grommet in the opposite direction as the wires entered. The grommet is preferably molded to the wires so that the combined product is inseparable from the wiring which it protects. The grommet is also described as a single piece grommet, although multiple piece grommets are anticipated.
Further disclosed in this application is an improved pass-through hinge for routing utilities, including water and electricity, from the door to the body of the refrigerator. The improved hinge features a hollow hinge pin through which utilities may be routed, thereby overcoming the deficiencies of the current state of the art.
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RELATED APPLICATIONS
This application contains subject matter similar to subject matter disclosed in copending U.S. patent application Ser. No. 09/366,216, filed on Aug. 2, 1999, and copending U.S. patent application Ser. No. 09/365,407, filed on Aug. 2, 1999.
TECHNICAL FIELD
The present invention relates to a method of manufacturing a semiconductor device having accurate and uniform polysilicon gates and underlying gate oxides. The present invention is applicable to manufacturing high speed integrated circuits having submicron design features and high conductivity reliable interconnect structures.
BACKGROUND ART
Current demands for high density and performance associated with ultra large scale integration require design rules of about 0.18 microns and under, increased transistor and circuit speeds and improved reliability. As device scaling plunges into the deep sub-micron ranges, it becomes increasingly difficult to maintain performance and reliability.
Devices built on the semiconductor substrate of a wafer must be isolated. Isolation is important in the manufacture of integrated circuits which contain a plethora of devices in a single chip because improper isolation of transistors causes current leakage which, in turn, causes increased power consumption leading to increased noise between devices.
In the manufacture of conventional complementary metal oxide semiconductor (CMOS) devices, isolation regions, called field dielectric regions, e.g., field oxide regions, are formed in a semiconductor substrate of silicon dioxide by local oxidation of silicon (LOCOS) or by shallow trench isolation (STI). A conductive gate, such as polysilicon, is also formed on the substrate, with a gate oxide layer in between.
A polysilicon layer is deposited on gate oxide. Thereafter, a patterned photoresist mask is formed on the polysilicon layer and the polysilicon layer - oxide layer is etched to form conductive gates with a gate oxide layer in between. Dielectric spacers are formed on sidewalls of the gate, and source/drain regions are formed on either side of the gate by implantation of impurities.
Photolithography is conventionally employed to transform complex circuit diagrams into patterns which are defined on the wafer in a succession of exposure and processing steps to form a number of superimposed layers of insulator, conductor and semiconductor materials. Scaling devices to smaller geometries increases the density of bits/chip and also increases circuit speed. The minimum feature size, i.e., the minimum line-width or line-to-line separation that can be printed on the surface, controls the number of circuits that can be placed on the chip and directly impacts circuit speed. Accordingly, the evolution of integrated circuits is closely related to and limited by photolithographic capabilities.
An optical photolithographic tool includes an ultraviolet (UV) light source, a photomask and an optical system. A wafer is covered with a photosensitive layer. The mask is flooded with UV light and the mask pattern is imaged onto the resist by the optical system. Photoresists are organic compounds whose solubility changes when exposed to light of a certain wavelength or x-rays. The exposed regions become either more soluble or less soluble in a developer solvent.
There are, however, significant problems attendant upon the use of conventional methodology to form conductive gates with gate oxide layers in between on a semiconductor substrate. For example, when a photoresist is formed on a highly textured surface such as polysilicon, and exposed to monochromatic radiation, undesirable standing waves are produced as a result of interference between the reflected wave and the incoming radiation wave. In particular, standing waves are caused when the light waves propagate through a photoresist layer down to the silicon nitride layer, where they are reflected back up through the photoresist.
These standing waves cause the light intensity to vary periodically in a direction normal to the photoresist, thereby creating variations in the development rate along the edges of the resist and degrading image resolution. These irregular refections make it difficult to control critical dimensions (CDs) such as linewidth and spacing of the photoresist and have a corresponding negative impact on the CD control of the conductive gates and gate oxide layers.
There are further disadvantages attendant upon the use of conventional methodologies. For example, distortions in the photoresist are further created during passage of reflected light through the polysilicon layer which is typically used as a hardmask for etching. Specifically, normal fluctuations in the thickness of the polysilicon layer cause a wide range of varying reflectivity characteristics across the polysilicon layer, further adversely affecting the ability to maintain tight CD control of the photoresist pattern and the resulting conductive gates and gate oxide layers.
Highly reflective substrates accentuate the standing wave effects, and thus one approach to addressing the problems associated with the high reflectivity of the silicon nitride layer has been to attempt to suppress such effects through the use of dyes and anti-reflective coatings below the photoresist layer. For example, an anti-reflective coating (ARC), such as a polymer film, has been formed directly on the polysilicon layer. The ARC serves to absorb most of the radiation that penetrates the photoresist thereby reducing the negative effects stemming from the underlying reflective materials during photoresist patterning. Unfortunately, use of an ARC adds significant drawbacks with respect to process complexity. To utilize an organic or inorganic ARC, the process of manufacturing the semiconductor chip must include a process step for depositing the ARC material, and also a step for prebaking the ARC before spinning the photoresist.
There exists a need for a cost effective, simplified processes enabling the formation of an ARC to prevent the negative effects stemming from the underlying reflective materials during photoresist patterning.
The present invention addresses and solves the problems attendant upon conventional multistep, time-consuming and complicated processes for manufacturing semiconductor devices utilizing an ARC.
DISCLOSURE OF THE INVENTION
An advantage of the present invention is an efficient cost-effective method of manufacturing a semiconductor device with accurately formed conductive gates and gate oxide layers.
Additional advantages of the present invention will be set forth in the description which follows, and in part, will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the present invention. The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims.
According to the present invention, the foregoing and other advantages are achieved in part by a method of manufacturing a semiconductor device, which method comprises:
forming an oxide layer on a semiconductor substrate;
forming a polysilicon layer on the oxide layer in a chamber;
forming a silicon oxime coating on the polysilicon layer in the chamber; and
forming a photoresist mask on the silicon oxime coating.
Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein embodiments of the present invention are described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1A-1E schematically illustrate sequential phases of a method in accordance with an embodiment of the present invention.
DESCRIPTION OF THE INVENTION
The present invention addresses and solves problems stemming from conventional methodologies of forming polysilicon gates and underlying gate oxides. Such problems include costly and time-consuming steps limited by materials which require different deposition systems and apparatus.
The present invention constitutes an improvement over conventional practices in forming polysilicon gates and underlying gate oxides wherein a photoresist is formed on a highly reflective surface, such as polysilicon. The present invention enables the formation of polysilicon gates and underlying gate oxides with accurately controlled critical dimensions. In accordance with embodiments of the present invention, the semiconductor device can be formed by: forming an oxide layer on a semiconductor substrate; forming a polysilicon layer on the oxide layer in a chamber; forming a silicon oxime coating on the polysilicon layer in the chamber; and forming a photoresist mask on the silicon oxime coating. Embodiments of the present invention include forming the silicon oxime coating and the polysilicon layer in the same deposition chamber.
Interconnect members formed in accordance with embodiments of the present invention can be, but are not limited to, interconnects formed by damascene technology. Given the present disclosure and the objectives of the present invention, the conditions during which the polysilicon layer and the silicon oxime layer are formed can be optimized in a particular situation. For example, the invention can be practiced by forming the polysilicon layer by introducing a silicon tetrahydride (SiH 4 ) gas in a chamber at a temperature greater than about 600° C., such as about 620° C. to about 650° C. Thereafter, the temperature is reduced to about 400° C., such as about 350° C. to about 450° C. and a layer of silicon oxime is formed on the polysilicon layer in the same chamber. Given the stated objective, one having ordinary skill in the art can easily optimize the pressure, and gas flow as well as other process parameters for a given situation. It has been found suitable to maintain a gas flow of about 250 to about 350 SCCM, such as about 300 SCCM and a pressure of about 100 to about 300 mTorr, such as about 200 mTorr, during deposition of the polysilicon layer. Thereafter, source gases for the components, i.e., silicon, nitrogen, oxygen and hydrogen, are reacted under dynamic conditions employing a stoichiometric excess amount of nitrogen, sufficient to substantially prevent oxygen atoms from reacting with silicon atoms. It has been found further suitable to introduce SiH 4 gas at about 50 SCCM, to introduce N 2 gas at about 400 SCCM, to introduce N 2 O gas at about 40 SCCM, with remote plasma on, at a pressure of about 4 Torr and a power of about 150 W and a temperature of about 400° C. during deposition of the silicon oxime layer. Thus, an effective antireflective coating of silicon oxime is formed by an elegantly simplified, cost-effective technique of forming both the polysilicon layer and the silicon oxime layer in the same chamber.
An embodiment of the present invention is schematically illustrated in FIGS. 1A-1E. Adverting to FIG. 1A, a wafer 20 comprising a semiconductor substrate 25 , such as silicon, is provided. A barrier layer 30 , comprising an oxide, e.g. silicon dioxide, is deposited on the substrate, as by subjecting the wafer to an oxidizing ambient at elevated temperature. Embodiments of the present invention comprise forming the oxide layer to a thickness of about 100 Å to about 200 Å.
With continued reference to FIG. 1A, an polysilicon layer 35 is deposited on the silicon dioxide layer 30 by placing the oxidized substrate in a chamber. The polysilicon layer 35 is formed by introducing a SiH 4 gas in a plasma deposition chamber at 300 SCCM at a pressure of about 200 mTorr and a temperature of about 620° C. Embodiments of the present invention comprise forming the polysilicon layer to a thickness of about 1200 Å to about 1600 Å.
With reference to FIG. 1B, an silicon oxime layer 40 is formed on the polysilicon layer 35 , as by reducing the temperature to about 530°. The silicon oxime layer 40 can be formed to a thickness of about 100 Å to about 600 Å. The silicon oxime layer 40 has an extinction coefficient (k) greater than about 0.4, such as about 0.4 to about 0.6, thereby permitting tighter critical dimension control during patterning of the photoresist and tighter critical dimension control of the polysilicon gate and gate oxide, subsequently formed on the substrate 25 . The tighter critical dimension control is possible since the silicon oxime layer 40 absorbs a large percentage of the reflected light and thus prevents a non-uniform distribution of reflected light which may otherwise be incident on the photoresist during photolithography patterning.
Referring to FIG. 1C, a photoresist mask 45 is formed on the silicon oxime layer 40 . Photoresist mask 45 can comprise any of a variety of conventional photoresist materials which are suitable to be patterned using photolithography. With continued reference to FIG. 1C, the photoresist mask 45 is patterned and holes 50 are formed in the photoresist mask 45 to provide an opening through which etching of the exposed silicon oxime layer 40 , polysilicon layer 35 and silicon dioxide layer 30 may take place. If critical dimensions, such as a line width and spacing, of the holes 50 in the photoresist mask 45 are not closely controlled, distortions occurring in forming the hole affect the dimensions of the polysilicon gate and gate oxide ultimately formed on the substrate 25 . As mentioned above, such distortions in patterning the photoresist mask 45 occur in conventional methodologies as a result of the high reflectivity of the polysilicon layer 35 and the thickness variations in the polysilicon layer and cause nonuniform photo-reflectivity. The silicon oxime layer 40 of the present invention substantially absorbs light reflected back through the polysilicon layer 35 , thereby reducing incident light on the photoresist mask 45 and preventing fluctuations which would otherwise occur in the critical dimensions of the holes 50 in the photoresist mask 45 .
Adverting to FIG. 1D, conventional plasma etching of the silicon oxime layer 40 , the polysilicon layer 35 , and the silicon oxide layer 30 is conducted to strip them from the wafer. The plasma etching may occur in a single step or consecutive plasma etching steps.
Referring to FIG. 1E, the photoresist mask 45 and optionally, the underlying silicon oxime layer 40 are stripped from the wafer (not shown), utilizing conventional etching techniques. With continued reference to FIG. 1E, a conductive polysilicon gate 35 A remains on substrate 25 with a gate oxide layer 30 A in between. At this point, the wafer continues to the next stage in the overall manufacturing process. Subsequent conventional processing steps, though not illustrated, typically include; forming dielectric spacers on sidewalls of the gate; and forming source/drain regions on either side of the gate by implantation of impurities.
In accordance with the present invention, metallization structures are formed in an elegantly simplified, efficient and cost-effective manner. Advantageously, the silicon oxime antireflective layer prevents the formation of standing waves and the negative effects stemming therefrom during photoresist patterning. The silicon oxime antireflective layer formed in accordance with the present invention is particularly advantageous in forming metallization interconnection patterns, particularly in various types of semiconductor devices having sub-micron features and high aspect ratios.
In the previous description, numerous specific details are set forth, such as specific materials, structures, chemicals, processes, etc., to provide a better understanding of the present invention. However, the present invention can be practiced without resorting to the details specifically set forth. In other instances, well known processing and materials have not been described in detail in order not to unnecessarily obscure the present invention.
Only the preferred embodiment of the present invention and but a few examples of its versatility are shown and described in the present disclosure. It is to be understood that the present invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.
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Polysilicon gates are formed with greater accuracy and consistency by depositing an antireflective layer of silicon oxime on the polysilicon layer before patterning. Embodiments also include depositing the polysilicon layer and the silicon oxime layer in the same tool.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sprayable aerosol shaving composition which is a liquid in the aerosol container and forms a gel upon application to the skin.
2. Prior Art
The preparation of aqueous gels employing as gelling agents polyoxyethylene-polyoxypropylene block copolymers is well known to those skilled in the art and is taught in several patents including U.S. Pat. No. 3,740,421. It is also known in the art to apply such compositions by the use of aerosol-type containers. However, filling an aerosol container with a gel presents problems.
U.S. Pat. No. 3,751,562, issued Aug. 7, 1973, to Nichols, discloses an aerosol gel formulation employing an oxyethylated fatty alcohol, mineral oil, iodine and water.
U.S. Pat. No. 4,293,542, issued Oct. 6, 1981, to Lang et al, discloses aerosol formulations which can be an aqueous gel containing oxyethylated fatty alcohols and a gel-forming agent and, as an essential component, a pyridine derivative.
British Pat. No. 1,096,357 discloses an aerosol gel comprising a partial fatty acid soap of a polyvalent metal hydroxide, and a nonpolar oil along with propellants.
British Pat. No. 1,444,334 discloses an aerosol gel composition which may be employed as a shaving cream composition and which contains as a gelling agent a polyoxypropylene-polyoxyethylene block copolymer. The composition also includes a water-soluble soap. This patent is concerned with the problem of expelling a gel from an aerosol container and particularly avoiding cavitation around the dip tube as can be seen from column 2 thereof.
Co-pending U.S. patent applications Ser. Nos. 513,439, 525,148 and 524,985 disclose aerosol gel compositions which are liquid in the aerosol can and form a gel upon application to the skin.
SUMMARY OF THE INVENTION
The cavitation problem discussed in British Pat. No. 1,444,334 as well as filling problems are overcome in accordance with the instant invention by the use of a pressurized composition which may be sprayed from an aerosol container and which is liquid inside the container and forms a gel on contact with living tissue such as the skin of a human when the shaving cream is applied. This is accomplished by the combination of water, propellant, volatile solvent and certain polyoxyethylene-polyoxypropylene block copolymers. As employed throughout the instant specification and claims, the term "solvent" means a solvent for the gel composition of this invention. The water/copolymer ratio for the shaving creams of this invention should be less than 4.5:1. The volatile solvent evaporates upon contact with body heat whereby the liquid becomes a foamy gel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The aerosol composition of the instant invention comprises by weight about 35 to 85 percent water, about 3 to 50 percent propellant, about 10 to 25 percent of the polyoxyethylene-polyoxypropylene copolymer and about 1 to 10 percent of the volatile solvent. The water/copolymer ratio is less than 4.5:1 with a preferred minimum ratio of 0.2:1. The composition may also include 0 to about 10 percent, preferably about 0.05 to 5.0 percent, of a treatment agent such as a beard softener or skin treatment agent, and 0 to 20 percent, preferably 1 to 10 percent of adjuvants.
The polyoxyethylene-polyoxypropylene block copolymer of use in the invention is a cogeneric mixture of conjugated polyoxyethylene-polyoxypropylene compounds corresponding to the following formula:
Y[(C.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H].sub.x (I)
wherein Y is the residue of an organic compound having from about 1 to 6 carbon atoms and containing x reactive hydrogen atoms in which x has a value of at least about 1, n has a value such that the molecular weight of the polyoxypropylene hydrophobe base is about 2250 to 7500 and m has a value such that the oxyethylene groups constitute about 45 to 90 weight percent of the compound. Falling within the scope of the definition for Y are, for example, propylene glycol, glycerine, pentaerythritol, trimethylolpropane, ethylene diamine and the like. The oxypropylene chains optionally, but advantageously, contain small amounts of oxyethylene and oxybutylene groups and the oxyethylene chains also optionally, but advantageously, contain small amounts of oxypropylene and oxybutylene groups. These compositions are more particularly described in U.S. Pat. Nos. 2,677,700, 2,674,619 and 2,979,528.
Nonionics which are particularly applicable are those in which Y is a propylene glycol residue, wherein the resulting formula is:
HO(C.sub.2 H.sub.4 O).sub.m (C.sub.3 H.sub.6 O).sub.n (C.sub.2 H.sub.4 O).sub.m H (II)
wherein n has a value such that the polyoxypropylene hydrophobe has a molecular weight of about 2250 to 4500 and m is the same as for formula (I).
Additional nonionics of particular value are those wherein Y is an ethylene diamine residue and the resulting formula is: ##STR1## wherein n has a value such that the hydrophobe has a molecular weight of about 3500 to 7500 and m is the same as in formula (I) above.
A composition which is a liquid inside the container and forms a gel on contact with living tissue is achieved by including a volatile solvent in the composition. Such solvents include alcohols such as methyl, ethyl and propyl, ketones such as acetone, ethers such as methyl, ethyl, methyl-ethyl, and similar ethers, and alkyl chlorides such as dichloromethane. Non-volatile solvents such as liquid polyethylene glycols, propylene glycol, and dipropylene glycol, etc. can be employed together with the volatile solvent provided the mixture is homogenous. A shaving cream gel composition which includes such volatile solvent should have a water/copolymer ratio of less than 4.5:1. The preferred minimum ratio is about 0.2:1.
The propellants can be any one or a blend of the following, as examples: propane, isobutane and other petroleum distillates, nitrogen, carbon dioxide, dimethylether, methylethylether, methylene chloride, vinyl chloride and fluorochlorohydrocarbons. The latter include Freon 115 pentafluorochloroethane and Freon C-318, octafluorocyclobutane.
A shaving cream composition would desirably contain at least one beard softener and/or skin treating agent which, when included would generally be in an amount of about 0.05 to 10 percent by weight. However, the polyoxyethylene-polyoxypropylene block copolymer may serve as the agent for wetting the chin and the beard whereby an additional agent would not be needed. If a high-foaming oxyalkylene copolymer is selected which has a polyoxypropylene hydrophobe molecular weight of about 2250 to 7000 and the oxyethylene groups constitute about 70 to 80 percent of the total molecular weight of the compound, it alone would serve as the foaming agent. If the polyoxyethylenepolyoxypropylene copolymer is a low-foaming copolymer, the shaving cream may also contain a small amount of a foaming agent, which may be nonionic, anionic, or amphoteric. Nonionics include high-foaming ethylene oxide adducts such as fatty alcohol ethoxylates and the anionics include sodium lauryl sulfate and lauryl ether sulfates. The propellant may also serve as a foaming agent eliminating the need for an additional foaming agent. Other examples of such foaming agents are triethanolamine lauryl sulfate, sodium dodecyl benzene sulfonate, water-soluble polyoxyethylene ethers of alkyl-substituted phenols, amine oxides, phosphate ester based surfactants, and water-soluble polyoxyethylene lauryl or dodecyl ethers. Numerous anionic and nonionic wetting agents suitable for the purposes of the present invention are described in detail in McCutcheon's "Emulsifiers and Detergents," 1982. Such agents could be included in amount of about 0.1 to 2.0 percent by weight.
Many and various adjuvants are generally also included in the these shaving cream gels. These could include proteins, amino acids, electrolytes and other ingredients normally found in body fluids. Humectants, such as propylene glycol or glycerine, may also be included. Further adjuvants could include silicone oils. Also, other adjuvants which impart further desired qualities to the skin may be incorporated in the compositions of the invention, e.g., skin fresheners or lather stabilizers or the like such as lanolin or its derivatives, lecithin, higher alcohols, dipelargonate esters or ethers, coconut oil and other fatty esters, and mixtures thereof may generally be used in minor proportions. Furthermore, coloring materials such as dyes and perfumes may be used, if desired. The amount of such adjuvants would range from 0 to about 20.0 percent by weight and preferably from about 1.0 to 5.0 percent by weight.
The following examples are included to further illustrate the present invention. Unless otherwise stated throughout the application, all parts and percentages are by weight and all temperatures are in degrees centigrade.
EXAMPLE 1
A concentrate is prepared from 20 parts of a polyoxyethylene-polyoxypropylene block copolymer of the type shown in formula (II) above, designated herein as copolymer #1, having a polyoxypropylene hydrophobe molecular weight of 4000 and containing oxyethylene groups in amount of 70 percent of the total copolymer weight, 3 parts propylene glycol and 77 parts water. Fifty-two parts of this gel concentrate and 6 parts of isopropanol are placed in an aerosol container. Thirty-five parts by weight of dimethylether propellant are then added through the valve. The contents when shaken and sprayed onto the face of an individual needing a shave forms a coating which becomes a foamy gel as the alcohol and propellant evaporate. This gel has good shaving characteristics and does not irritate the skin.
EXAMPLE 2
Example 1 is repeated substituting for copolymer #1 a polyoxyethylene-polyoxypropylene copolymer of the type shown in formula (III) above, referred to herein as copolymer #2, having a hydrophobe molecular weight of 7000 and containing oxyethylene groups in an amount of 80 percent of the total copolymer weight. When sprayed from the aerosol container onto the face of an individual needing a shave, a coating is formed which becomes a foamy gel as the solvent and propellant evaporate. This gel has good shaving characteristics and does not irritate the skin.
EXAMPLES 3-8
Six solutions are made up from all the components excluding the propellants of each of the example compositions set forth below and each placed in its individual aerosol container. The container is sealed with a valve and the respective propellant added through the valve. The contents of each when shaken and sprayed onto the face of an individual needing a shave form a coating which becomes a foamy gel as the propellant evaporates. This gel has good shaving characteristics and does not irritate the skin. The compositions are as follows:
______________________________________ Example 3 16 Copolymer #1 3 Ethyl Alcohol 1 Lauric Diethanolamide 60 Water 20 Dimethyl Ether (Propellant) 100 Example 4 15 Copolymer #3 10 Ethyl Alcohol 1 Lanolin Alcohol 39 Water 35 Isobutane (Propellant) 100 Example 5 18 Copolymer #1 2 Isopropyl Myristate 1 Lanolin 3 Isopropyl Alcohol 66 Water 10 Pentane (Propellant) 100 Example 6 20 Copolymer #4 2 Isopropyl Palmitate 1 Dimethyl Polysiloxane 3 Ethyl Alcohol 50 Water 24 Freon 115 Propellant 100 Example 7 15 Copolymer #1 3 Glyceryl Stearate 2 n-propanol 65 Water 15 Freon C-318 Propellant 100 Example 8 13 Copolymer #1 20 Glycerin 7 Freon 115 propellant 50 Water 10 Ethyl Alcohol 100______________________________________
In the above Examples:
Copolymer #3 is a polyoxethylene-polyoxypropylene block copolymer of the type shown in formula (II) above having a polyoxypropylene hydrophobe molecular weight of 3250 and containing oxyethylene groups in amount of 50 percent of the total copolymer weight.
Copolymer #4 is a polyoxyethylene-polyoxypropylene block copolymer of the type shown in formula (II) above having a polyoxypropylene hydrophobe molecular weight of 3250 and containing oxyethylene groups in amount of 80 percent of the total copolymer weight.
EXAMPLE 9
A solution comprising 20 parts of copolymer #1, 4.0 parts of isopropanol, 2 parts of 150 molecular weight polyethylene glycol, 3 parts acetylated lanolin alcohol, 0.7 parts of fragrance, 1.0 part of 90 molecular weight polyethylene glycol, 0.2 part D&C Yellow No. 10 dye, 0.1 part F.D.&C Blue No. 1 dye, 2 parts specially denatured ethyl alcohol, and 67.1 parts water is prepared.
One hundred parts of the above liquid are placed in an aerosol container, the container is pressurized and sealed with a valve and 50 parts of isobutane propellant added through the valve. The contents when shaken and sprayed onto a human face having a growth of beard form a coating which becomes a foamy gel as the propellant evaporates. The beard is softened for shaving without irritating the skin.
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A pressurized shaving cream composition in an aerosol container and adapted to form a spray upon release of pressure therefrom which composition is a liquid inside the container and forms a gel on contact with living tissue comprising water, volatile solvent, propellant and a polyoxyethylene-polyoxypropylene copolymer. The preferred composition also includes a volatile solvent and may advantageously include a treatment agent and conventional additives.
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BACKGROUND
1 Field of the Invention
The present invention relates generally to wireless communications, and more particularly, to a data link layer tunneling technique for resending missed frames between a packet sending unit and a packet receiving unit over a logical tunnel channel to improve the throughput of high speed data in a noisy wireless environment.
2. Description of the Prior Art
Fixed wireless systems are used to communicate voice and high speed data (HSD) between a base station (BS) and multiple remote units (RU) over an air-interface. HSD is generally used for web browsing, down loads and file transfer protocols (FTP). All data must be transferred notwithstanding the predictable errors caused by the communications links employed in the system (e.g., a 10E-03 Bit Error, Rate (BER)). Accordingly, communication protocols have been developed for transmitting data in discrete blocks commonly referred to as “frames.” These frames are evaluated at the receiving end to determine if the data is correctly received. If certain frames are in error or missed, those frames are retransmitted by the sending station.
Communications protocols are commonly based on the layered network architecture such as OSI. This is a 7-layer architecture including a physical layer (connectors, media, electrical signaling) and a data link layer, which packages the data into frames, manages data transmission over a link (error handling and the like), and facilitates access control (when each station may transmit). One way of achieving full-duplex data transmission over a single communication channel utilizes what is known in the art as a “sliding window protocol.” At any instant in time, the sender maintains a list of consecutive sequence numbers corresponding to frames it is permitted to send. These frames fall within a “sending window.” In the same manner, the receiver maintains a “receiving window” corresponding to the frames it is permitted to accept. The sending and receiving windows do not necessarily have the same upper and lower limits, or the same size. The sequence numbers within the sender's window represent frames sent but not yet acknowledged. Whenever a new data packet arrives from the network layer, it is given the next highest sequence number, and the upper edge of the window is advanced by one. When an acknowledgement is received, the lower edge of the window is advanced by one. The window continuously maintains a list of unacknowledged frames. Since frames currently within the sender's window may be lost or changed during transmission, the sender must keep all the sent frames in memory in the event a retransmission is required. Accordingly, if the maximum window size is “K”, the sender needs K buffers to hold the unacknowledged frames in memory. If the window ever exceeds it's maximum size, the sending data link layer must shut off the network layer until a buffer is freed up. The receiving data link layer's window corresponds to the frames it can accept. Any frame that falls outside the window is discarded. When a frame with a sequence number equal to the lower edge of the window is received, that frame is passed to the network layer, an acknowledgment is generated to the sender, and the window is rotated by one. Unlike the sender's window, the receiver's window always remains at its initial size.
An example of a sliding window protocol in a data communications system is disclosed in U.S. Pat. No. 4,841,526. In the '526 patent, the window size of the sending or receiving station is selected in accordance with the speed, length or error rate of the communication link or frame size used to maximize the communication link. The negative acknowledgements sent by the receiving station specify the upper and lower limit of a range of identification numbers of frames unsuccessfully received to increase transmission efficiency. Before data is transmitted, the sending and receiving stations exchange preferred sets of link parameters and generate a modified set of link parameters to resolve potential conflicts. One of the sending and receiving stations stores a table defining the frame sizes for use with different bit error rates of the communication link. The station evaluates the current bit error rate to select the optimum frame size from the table and adjust the frame size.
To provide HSD over a wireless system, a large window size (K) is required. As an example, at a transmission rate of 512 kbps, a window size K of 45 is used. In such a system, loss of a frame will cause relatively long silent periods or what is referred to as “channel idle.” Application layers such as FTP or web browsing pump data at a higher rate than the air link data thereby causing the data link layer window to be filled at a very fast rate. If the receiving station loses a frame, it sends a selective reject message (SREJ) to the sending station. By the time the sending station receives the SREJ, however, the window can be filled, and neither the sender nor receiver will be able to transmit or receive until the outstanding frame clears. This causes a silent or “channel idle” period where the sending station cannot transmit and the receiving station cannot receive more than the last acknowledged frame (Va)+window size (K).
In view of the above, there exists a need for a new method of enhancing HSD transmission in wireless environments that reduce the idle periods caused by lost frames.
SUMMARY OF THE INVENTION
In view of the above, it is an object of the present invention to provide a data link layer tunneling technique for improving the throughput of high speed data in a noisy wireless environment.
It is another object of the invention to prevent large idle gaps, over a wireless communications channel caused by missed frames.
It is still another object of the present invention for the data link layer to establish a tunnel to clear outstanding frames and enable data packets to be exchanged even when the window is full.
In accordance with the above objects and additional objects that will become apparent hereinafter, the present invention provides a method of recovering lost frames transmitted between a packet sending unit and a packet receiving unit in a data communications system. The method generally comprises the steps of: (a) identifying a failure to successfully receive a missed frame at the packet receiving unit; (b) establishing a logical tunnel channel at the packet receiving unit to acknowledge the next successfully received frame; (c) starting a first timer at the packet receiving unit; (c) upon receiving a tunnel establishment request (TER) from the packet receiving unit, the packet sending unit resending the missed frame on the logical tunnel channel and starting a second timer; and (d), the packet sending unit resending the missed frame a specified, number of times until receiving an acknowledgement from the packet receiving unit.
In accordance with the method, the packet sending unit sends an I-frame to the packet receiving unit. Upon successful receipt of an I-frame and identification of a missing frame, the packet receiving unit generates a supervisory frame (TER) with a sequence number N(R) set to the missing frame and payload set to the number of consecutive frames. The packet receiving unit establishes a logical tunnel channel, sends the TER (frame, payload) to the packet sending unit, and starts a first timer. When the TER (frame, payload) is received, the packet sending unit starts a second timer and resends the missed frame over the logical tunnel channel. If the retransmitted missed frame is not received by the packet receiving unit before the first timer expires, the packet receiving unit retransmits the TER a predetermined number of times. If the retransmitted frame is not received by the packet receiving unit after being retransmitted a predetermined number of times and frame overflow does not occur, the frame is recovered using a normal recovery procedure. If the first timer has not expired, the packet receiving unit continues to acknowledge all frames with a predetermined poll bit setting irrespective of when the sender's window closes. If the missed frame is acknowledged, the packet receiving unit sends a receive ready (RR) message to the packet sending unit. If the acknowledgement for retransmitted I-frame does not come before the second timer expires, the packet sending unit will send the same frame a predetermined number of times. If the packet sending unit receives the RR message, it closes the layer tunneling channel (LTC). If the packet sending unit has resent the missing frame the predetermined number of times and no confirmation has been received from the packet receiving unit, a normal recovery is made.
The present invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a conceptual schematic of a representative wireless communications system;
FIG. 2 is an operational flow diagram of the normal data transfer between the packet transmitting and receiving stations Tx and Rx, respectively;
FIG. 3 is an operational flow diagram of a missing frame and tunneling operation;
FIG. 4 is an operational flow diagram of a tunneling operation;
FIGS. 5A and 5B are flowcharts of the sequence depicted in FIG. 4 at Rx and Tx respectively; and
FIG. 6 is an operational flow diagram of an error recovery sequence.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the drawings, FIG. 1 depicts a conceptual diagram of a wireless communications network (WCS) generally characterized by the reference numeral 10 . The WCS 10 serves a number of wireless remote units (“RU”) 12 A-I within a geographic area partitioned into a plurality of spatially distinct regions called “cells” 14 A-C . Each cell 14 includes a respective base station (“BS”) 16 A-C , and a boundary represented by an irregular shape that depends on terrain, electromagnetic sources and many other variables. The remote units communicate via one or more wireless access technologies (e.g., TDMA, CDMA, FDMA, etc.), providing one or more services (e.g., cordless, cellular, PCS, wireless local loop, SMR/ESMR, two-way paging, etc.) with signals representing audio, video, high speed data (HSD), multimedia, etc. Each BS 22 communicates with a Mobile Switching Center (MSC) 18 , also known as a mobile telephone switching office, in accordance with well-known standards. The MSC 18 is interconnected with a customer service center 20 and a router 22 to a wide area network (WAN) 24 . The MSC is also connected to local switching offices (not shown) that access wireline terminals, and a toll switching office (not shown). The MSC 18 has several functions, including routing or “switching” calls between wireless communications terminals or base stations or, alternatively, between a wireless communications terminal and a wireline terminal accessible to a MSC 18 through LSOs and/or TSOs. The operation of the WCS is well known and need not be described in detail with respect to the present invention. For the purpose of illustration, a base station (BS) 22 corresponds to a “packet sending unit” Tx and a remote unit (RU) 18 corresponds to a “packet receiving unit” Rx. In normal operation data is transferred from Tx to Rx, and Rx sends acknowledgement information back to Tx. The acknowledgment information is communicated in the form of data groups including control information and acknowledgement information, or the acknowledgments are “piggybacked” onto data frames communicated in the opposite direction from Rx to Tx using known protocols. Although the drawings depict an illustrative mobile wireless system, the protocols herein have equal applicability to fixed wireless systems (FWS) which are used to connect a fixed subscriber to a digital switching center and a data service node via a neighborhood antenna.
In the illustrative embodiment, HSD travels over an air data link 26 between Tx and Rx. The data link layer may be “asymmetrical,” i.e., the downloading data rate from Tx to Rx can be greater than the uploading data rate from Rx to Tx, or Tx>Rx. As an example, the data downlinked from Tx to Rx is 512 Kilo bits per second (Kbps), and the data uplinked from Rx to Tx is 128 Kbps. In accordance with the sliding window protocol, at any instant in time Tx maintains a list of consecutive sequence numbers corresponding to frames it is permitted to send. These frames fall within a “sending window.” In the same manner, Rx maintains a “receiving window” corresponding to the frames it is permitted to accept. The sending and receiving windows do not necessarily have the same upper and lower limits, or the same size. The sequence numbers within the sender's window represent frames sent but not yet acknowledged. Whenever a new data packet arrives from the network layer, it is given the next highest sequence number, and the upper edge of the window is advanced by one. When an acknowledgement is received, the lower edge of the window is advanced by one. The window continuously maintains a list of unacknowledged frames. Since frames currently within the sender's window may be lost or changed during transmission, the sender must keep all the sent frames in memory in the event a retransmission is required. Accordingly, if the maximum window size is “K”, the sender needs K buffers to hold the unacknowledged frames in memory. If the window ever exceeds it's maximum size, the sending data link layer must shut off the network layer until a buffer is freed up. The receiving data link layer's window corresponds to the frames it can accept. Any frame that falls outside the window is discarded. When a frame with a sequence number equal to the lower edge of the window is received, that frame is passed to the network layer, an acknowledgment is generated to the sender if the poll bit is set to “1” (P=1), and the window is rotated by one. Unlike the sender's window, the receiver's window always remains at its initial size. In the illustrative example the window size (K)=45, and the maximum sequence number Ns=127 (2 7 −1). This means that Ns varies from 0 to 127 and subsequently rolls over. In high bandwidth systems, the sequence numbers can go up to 16,383 (2 14 −1). As shown in the drawings, the poll bit setting equals the last acknowledged frame +K−1, or the last acknowledged frame +(K*3)/4. Alternatively, the poll bit may be specified at any other time for explanation purposes only.
The following terminology regarding the interchange of information between Tx and Rx applies throughout this application and is listed below for reference as it is well understood by those skilled in the art: Send state variable V(S): a variable that identifies the sequence number of the next frame to be transmitted. The V(S) is incremented with each frame transmitted.
Receive state variable V(R): a variable that denotes the number expected to be in the sequence number of the next frame. The V(R) is incremented with the receipt of an in-sequence and error-free frame.
Send sequence Number(Ns): this number indicates to the receiver the sequence number of the next frame that will be transmitted by the sender.
Receiving Number N(R): an expected send sequence number (Ns) of then next to be received frame. It indicates up to N(R)−1 frames that were successfully received.
Acknowledge state variable V(A): the last frame that has been acknowledged by the sender's peer. The Va is updated upon receiving an error free I or Supervisory (S) frame in sequence having a receiving sequence number Nr value is one that is in the range of Va<=Nr <=Vs.
value
Type
Description
512 Kbps
K
window size: window size of sliding window
45
protocol.
T200
Re-establishment/Retransmit timer: Tx expects an
5
Sec
acknowledgement before the T200 timer expires.
Tx retransmits the same packet N200 times
before it gets an acknowledgment until T200
expires.
T201
TER Recovery Timer: Acknowledgements for
5
Sec
retransmitted out of sequence frames should
occur before T201 expires. If T201 expires Tx
retransmits the out of sequence I frame N201
times before re-establishment.
T202
TER Retransmit Timer: The out-of-sequence
5
Sec
frame should be received before T202 expires,
otherwise Rx retransmits the SREJ frame N202
times before re-establishment.
T203
Idle Timer
20
Sec
T205
Piggy Back Timer
2
Sec
N200
T200 retry count
5
X
N201
T201 retry count
5
X
N202
T202 retry count
5
X
The data link layer uses an “Information Frame” or “I”-frame as discussed above, to represent a protocol data unit (PDU) transmitted between a packet sending unit and a packet receiving unit (i.e., Tx and Rx). An illustrative frame format is shown below:
8
7
6
5
4
3
2
1
Address Field (TEI)
Address field size: 2 octets
Length Field
Length field size: 2 octets
Control Field
Control field size: 2 to 5 octets
Information Field
Info. field size: Up to 251 bytes
The basic numbering convention is based on bits grouped into octets as specified in the Q.921 recommendation that is well known in the art.
The address field is represented by the Terminal Endpoint Identifier (TEI) assigned to each RU, and two control bits. The address field extension (EA) bit is used to indicate the extension of TEI octets. When set to “0”, it signifies that another octet of the TEI follows. A “1” indicates that it is the final octet. The command/response (C/R) bit identifies a frame as either a command or a response. The transmitter sends commands with C/R set to “1” and responses with C/R set to “0”. The RU does the opposite with commands with the C/R set to “0” and responses with the C/R set to “1”. The address field format is shown below:
8
7
6
5
4
3
2
1
C/R
TEI (higher order)
TEI (lower order)
EA = 1
The frame length field indicates the total data link frame length in bytes and includes the data rate as follows:
8
7
6
5
4
3
2
1
octet 1
data rate
RES
higher order 3 bits
octet 2
Lower order 8 bits
The data rate is used for Tx to identify and communicate with different receiving stations. The control field contains the commands, responses, and the sequence numbers to maintain data flow accountability of the link between the Tx and Rx. It also defines the frame functions and invokes logic to control traffic. The content and size of the control field vary according to the use of the frame. The field can be in one of three formats: information (I), supervisory (S), and unnumbered (U).
The information frame (I-frame) which is shown in the drawings, is used to transmit end-user data between Tx and Rx. The information frame may also acknowledge the receipt of data from a transmitting end point. It also can perform such functions as a poll command. Traffic at Tx and Rx is controlled by counters called state variables. These counters will be maneuvered based on the received I-frame control field values. The I-frame control field format is shown below:
8
7
6
5
4
3
2
1
octet 1
(higher order) N(S)
0
octet 2
N(S) (lower order)
P/F
octet 3
N(R) (higher order)
octet 4
N(R) (lower order)
RES
octet 5
M
EM
RES
SAPI
The sequence number Ns is the identification number for the I-frame. Typically the I-frames are numbered in the same order as their transmission. Similar to Q.921, I-frames are always exchanged as command type frames during multiple frame operation on point-to-point connections. A Poll/Final (P/F) or “Poll Bit” is used to solicit a response from the peer entity. When the P bit set to 1 (P=1), the sender Tx will solicit a response frame from Rx. The More (M) bit is used to indicate that the current PDU is the last data unit in a complete application packet. The I-frame may support either an encrypted or unencrypted payload. This is not relevant to the present invention but is included for purposes of illustration with respect to frame formats as the Encryption Mode Enabled/Disabled (EM) bit. Finally, the Service Access Point Identifier (SAPI) includes 4 bits that indicate the target application type. The values are defined as: 0×0000—IP SAPI, 0×0001—OM SAPI, 0×0010—SA SAPI.
The supervisory frame (S-frame) is used to perform such control functions as acknowledgment of frames, request for retransmission of frames, and request for the temporary suspension of frame transmission. The supervisory frame format follows:
8
7
6
5
4
3
2
1
octet 1
Reserved
S-Type
0
1
octet 2
P/F
N(R) (higher order)
octet 3
N(R) (lower order)
RES
The supervisory frame supports 4 different command/response types: Receive/Ready (RR); Receive Not Ready (RNR); Tunnel Establishment Request (TER) and Selective Reject (SREJ). N(R) is the expected send sequence number of the next I-frame to be received. The Poll/Final bit (P/F), unlike an I-frame, can be used to signify either command or response mode. In the command frame, the P/F bit is referred to as the P bit; and in response frame, it is referred to as F bit. The reserved field value is set to 0.
The receive ready (RR) frame format is used to indicate that Rx is ready to receive an I-frame, acknowledge a previously received I-frame numbered up to and including N(R)−1, clear a busy condition that was indicated by the earlier transmission of an RNR frame, and solicit Tx's status by sending an RR command with the P bit set to 1. The RR frame will also close the TER. The RR frame format follows:
8
7
6
5
4
3
2
1
octet 1
0
0
0
0
0
0
0
1
octet 2
P/F
N(R) (higher order)
octet 3
N(R) (lower order)
RES
The receive not ready (RNR) frame is used to indicate a busy condition where it is unable to accept additional incoming I-frames temporarily. The value of N(R) acknowledges I-frames up to and including N(R)−1. The busy condition can be cleared by sending a RR or TER frame. The RNR also enables Tx to solicit the status of Rx by sending the RNR command with the P bit set to 1. The RNR frame format follows:
8
7
6
5
4
3
2
1
octet 1
0
0
0
0
0
1
0
1
octet 2
P/F
N(R) (higher order)
octet 3
N(R) (lower order)
RES
The TER frame is used to request retransmission of single frame or multiple frames (single+payload) identified in the N(R) field+payload field. When sent as a command frame, if the P bit of the SREJ or TER frame is set to 1, the I frames numbered up to N(R)−1 inclusive, are considered as acknowledged. However, if the P bit is 0, then the N(R) of the SREJ or TER frame does not indicate acknowledgment of I frames. In a response frame, no acknowledgment is allowed. The SREJ/TER condition is cleared upon receipt of an I-frame with an N(S) equal to the N(R) of SREJ/TER frame. Once an SREJ or TER frame has been received, the I-frame that may have been transmitted following the I-frame indicated by the SREJ/TER frame is not be retransmitted as a result of receiving the SREJ/TER frame. Additional I-frames awaiting initial transmission may be transmitted following the retransmission of the requested I-frame. The SREJ frame format is shown as:
8
7
6
5
4
3
2
1
octet 1
0
0
0
0
1
1
0
1
octet 2
P/F = 0
N(R) (higher order)
octet 3
N(R) (lower order)
RES
octet 4
Payload
The TER frame is similar to the SREJ format, except the bits in Octet 1 have been changed to identify this as a TER in lieu of an SREJ frame as follows:
8
7
6
5
4
3
2
1
octet 1
0
0
0
0
1
0
0
1
octet 2
P/F = 0
N(R) (higher order)
octet 3
N(R) (lower order)
RES
octet 4
Payload
FIG. 2 is an operational flow diagram of the normal data transfer between the packet transmitting and receiving stations Tx and Rx, respectively. Rx will acknowledge all frames (I) received with the poll bit set to 1 (P=1) in accordance with the above description. Here, frames I( 0 ), I( 20 ), and I( 125 ) are designated with P=1. Respective acknowledgments (ACK) for I( 0 ), I( 20 ) and I( 125 ) are communicated to Tx upon receipt of the respective P=1 frames. Alternatively, Rx can wait for the T 205 “piggyback” timer to expire before it sends the acknowledgment. T 205 is set upon receipt at Rx of an I-frame with P=0. When P=1, Rx will send immediate acknowledgments. In a piggyback operation, Rx sends the acknowledgment information for the received frames along with any data to be communicated to Tx using known protocols.
In accordance with the present invention, a Logical Tunnel Channel (LTC) is established between Tx and Rx when a frame gets lost during a normal transmission. The LTC is used to transport the missed frames between Tx and Rx. Because the transmission of such frames is made over a separate channel, Tx will assume that the missed frames have been transported successfully, and the sender's window (SW) will be “continuous” unless the initial missed frame is not transported successfully before SW reaches the initial missed frame −1.
Referring now to FIG. 3, frame I( 39 ) was lost during transmission from Tx to Rx. The. “missed” status of I( 39 ) is detected at Rx upon receipt of I( 40 ). Rx establishes the LTC to acknowledge I( 40 ) and enable the retransmission of I( 39 ) to Rx. The format of the TER message is described above. Rx will keep on sending acknowledgments for all frames received with poll bit set to 1. Upon receiving the TER (frame, payload) from the Rx, Tx resends I( 39 ) over the LTC. Therefore, upon receiving the acknowledgment for I( 40 ), Tx's window is still continuous because the missed frame I( 39 ) is transported through the LTC. However, if the missed frame I( 39 ) is not transported successfully by the time sender transmits the next I( 38 ) (on the assumption set forth herein of a window size K=45 and 128 sequence numbers), the window will be stopped.
In this example, the sender Tx had a “time” window that extended to the maximum number of sequence numbers (in this case. 128 ), instead of a window size K=45. With a maximum sequence number much greater than the window size, there is more time to transport the missed frames before the window stops. This has the advantage in that the maximum sequence number can be increased to as large a value as the frame permits. Rx can send an SREJ to Tx in lieu of an TER to provide for backwards compatibility.
Referring now to FIGS. 4, 5 A and 5 B, there are depicted respective operational flow diagrams of an actual tunneling operation. FIG. 5A refers to the operational flow at Rx and FIG. 5B shows the operational flow at Tx. The diagrams illustrate loss of a single I-frame and the tunneling operation to recover the frame over the LTC. As can be seen in FIG. 4, I-frames ( 0 -N) are communicated between Tx and Rx. At step 100 (FIG. 5 A), I(N) is received by Rx. Rx checks whether I(N−1) was successfully received at step 102 . Here in the example shown and described, I( 1 ) has been lost as indicated by the “x” in FIG. 4 . Upon receiving frame I( 2 ), Rx sets payload=number of consecutively missed frames at step 104 . The sequence number N(R) is set to 1 and payload set to NULL (indicating a single frame was missed). If (N−1) was successfully received, Rx checks whether I(N) has a poll bit setting of P=1 at step 106 . If P=1, then an acknowledgment (ACK) is generated for I(N) at step 108 , and communicated to Tx at step 110 . If P=0, then Rx starts the piggyback timer T 205 at step 112 . Rx will then generate the ACK for the last frame received at step 113 upon expiration of T 205 and send the ACK to Tx at step 115 . If the frame was missed, Rx establishes the LTC at step 114 and generates a TER (I_missed, payload) at step 116 . Rx then sends TER (I_missed, payload) to Tx at step 118 and simultaneously starts timer T 202 at step 120 . Rx then sets N 202 _RTC (retry count) to 1 at step 122 . At step 124 (FIG. 5 B), Tx receives TER (I_missed, payload), and starts timer T 201 at step 126 . Tx also sets the TER retry count N 201 _RTC to 1 at step 128 . Tx will resend the missed frame(s) identified as I_missed+payload at step 130 over the LTC. This transmission occurs while Tx continues to send frames to Rx using regular procedures. If the retransmitted frame(s) is not received by Rx before T 202 expires at block 132 (FIG. 5 A), Rx checks whether N 202 _RTC >N 202 at step 134 . If N 202 _RTC exceeds the predetermined resend count, then N 202 _RTC is reset to 0 at step 136 . A normal recovery of the missed frame(s) is made at step 138 . If N 202 _RTC is not>than N 202 at block 134 , Rx starts T 202 again at step 140 , resends TER (I_missed, payload) at step 142 , and increments T 202 _RTC at step 144 . Rx will continue to retransmit the TER N 202 times. Rx continues to acknowledge all frames with P=1 at 106 , irrespective of when SW closes. When the missed frame(s) is received (step 146 ), Rx stops T 202 at step 148 and sends a receive ready (RR) message to Tx at step 150 indicating the last frame acknowledged N(R)−1 and the next frame expected N(R). After the RR for the retransmitted frame(s) is received by Tx (step 152 ) the LTC is closed (step 156 ) and T 201 stopped (step 158 ). If the RR has not been received and T 201 expired (step 154 ), Tx checks at step 160 whether N 201 _RTC>N 201 . If the answer to this query is “yes”, Tx sets N 201 _RTC=0 at step 162 and a normal recovery is made at step 164 . If retry counts remain, Tx starts T 201 again at step 166 , resends the missed frame(s) at step 168 and increments N 201 _RTC at step 120 . Tx will send the same frame N 201 times.
Referring now to FIG. 6, there is depicted an operational flow diagram of an error recovery sequence using the tunneling operation of the present invention. As discussed above and illustrated in FIGS. 3 and 4, I( 1 ) has been lost during transmission from Tx to Rx. Upon successful receipt of I( 2 ), Rx generates a TER (frame, payload=0) indicating that frame I( 1 ) was missed, and establishes the LTC to Tx. Rx starts timer T 202 and communicates the TER (frame, payload) to Tx. When the TER (frame, payload) is received at the Tx, it will start timer T 201 , and send I-missed, payload to Rx. 1 . If the retransmitted frames I_missed, payload is not received by Rx prior to expiration of T 202 , Rx will retransmit the TER to Tx N 202 times. In this example, I_FRM( 1 ) is received by Rx prior to the expiration of T 202 . Rx generates an acknowledgement RR, which is lost in transmission from Rx to Tx prior to the expiration of T 201 . Tx then resends I_FRM( 1 ) and starts timer T 201 again and the process repeats until Tx receives an RR frame corresponding to the retransmitted frame. If the RR frame is not received by the time the T 201 timer expires, Tx retransmits to Rx N 201 times. Upon receipt of the RR for the tunnel channel frame by Tx, the LTC is closed.
The present invention has been shown and described in what are considered to be the most preferred and practical embodiments. It is anticipated, however, that departures may be made therefrom and that obvious modifications will be implemented by those skilled in the art.
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In accordance with the invention, a data link layer tunneling technique is disclosed for improving the throughput of high speed data in a noisy wireless environment. The method for recovering lost frames transmitted between a packet sending unit and a packet receiving unit in a data communications system, and generally comprises the steps of: (a) identifying a failure to successfully receive a missed frame at the packet receiving unit; (b) establishing a logical tunnel channel at the packet receiving unit to acknowledge the next successfully received frame; (c) starting a first timer at the packet receiving unit; (c) upon receiving a tunnel establishment request from the packet receiving unit, the packet sending unit resending the missed frame on the logical tunnel channel and starting a second timer; and (d) the packet sending unit resending the missed frame a specified number of times until receiving an acknowledgement from the packet receiving unit.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This patent application is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/680,059, filed Oct. 7, 2003.
FIELD OF THE INVENTION
[0002] This invention relates generally to apparatuses and methods for laying underground cable or irrigation tubing.
BACKGROUND OF THE INVENTION
[0003] Aesthetics have always played an important role in home design and landscaping. Indeed, most homeowners take pride in the appearance of their yards and landscaping, often devoting many hours each weekend to ensuring that their lawn and garden look attractive and uncluttered.
[0004] Unfortunately, the necessities of day-to-day living often result in the use and installation of unsightly equipment. For example, the use of a garden hose and sprinkler to water the lawn and garden, the use of a fence to contain a pet, the running of cables and wires for lighting, cable TV, internet services, etc. all are visibly unappealing to many homeowners. The solution of choice for many homeowners is to run such cables, wires, pet containment systems, sprinkler systems, etc., underground so as to be hidden from view while still allowing the homeowner to reap the benefits provided thereby.
[0005] To run each of these varied systems underground, in the past, trenchers have been used to dig a small trench in the yard into which is laid the cable, wire, pipe, etc., for the particular system being installed. The soil removed from the trench is then put back in over the wire, cable, pipe, etc. In this way, each of these systems, wires, cable, etc., are hidden from view.
[0006] Unfortunately, this solution to the aesthetic problem has resulted in an underground maze of wires, cable, pipes, etc., for which no coordinated mapping is typically provided. Further, utility marking services such as JULIE do not provide marking of such consumer-installed underground cables, wires, pipes, etc., instead only marking the main utilities of gas, electric, water, etc. As a result, the attempted installation of subsequent underground systems using a trencher often results in damage or breakage of the underground lines, cables, wires, pipes, etc., of previously installed underground systems. This not only results in frustration of the homeowner as the affected system may no longer be used until it is repaired, but also additional expense for the installers of the subsequent underground systems who have caused the damage and now must bear the expense of repair. Additionally, the type of damage resulting from the use of current methods for underground cable laying often results in multiple breaks in the underground system. That is, oftentimes the underground line, cable, wire, pipe, etc., is snagged by these trenching apparatus and pulled along until a failure occurs in the affected system. Such failures may be at locations other than the point at which the system was snagged by the trencher, often requiring a large portion of the damaged underground system to be dug up to effectuate the repair at the locations of the break.
[0007] A further disadvantage with current methods for laying underground cable, wire, flexible tubing, etc., is that the current methods leave a visible scar in the yard. This scar typically requires the planting of additional grass or other ground cover seed, which further increases the expense, detracts from the aesthetics which it was meant to protect, and requires additional lawn care to properly water the newly planted seed to ensure germination and full growth to fully hide the trenched scar.
[0008] The above-mentioned problems, and desires, are not limited to residential installations, but are also encountered in institutional and commercial settings. For example, a great deal of care is often lavished on establishing and maintaining healthy turf on athletic fields, used for playing football, baseball, soccer, or other outdoor sports. Large grassy areas, forming part of the landscaping around commercial buildings, in public or private parks, and on golf courses, are also examples of places in which it is often necessary, or desirable, to provide complex underground irrigation installations, or to run cabling for electric power, communication, lighting systems, or heating systems under the surface of the turf.
[0009] Where it becomes necessary, or desirable, to run additional cables or tubing through an area of established turf, it is desirable that such additional cables or tubing be installed in a manner which does not leave a visible scar in the existing turf, or damage underground cable or tubing which is already in place under the turf.
[0010] Previously available equipment and methods have not proved to be entirely satisfactory in alleviating the above-mentioned problems, and in meeting the above described desires. For example, in one piece of equipment currently being marketed for installation of subsurface dripperlines in turf grass, a multi-blade lawn plow includes a vertically mounted coulter wheel, for slicing through the turf of a football field, or the like, followed by a ripper blade extending below the coulter wheel, and having a passage therein for feeding dripperless irrigation tubing into the ground behind the ripper blade. The lawn plow further includes a pair of tamping feet mounted adjacent the ripper blade for compacting the soil after the dripperline has been buried. The entire multi-blade plow apparatus is mounted on a frame, which is in turn attached to a vibrating mounting arrangement of a trenching-type machine. Where the subsurface installation includes existing underground cabling and/or tubing, the ripper blades of the multi-blade lawn plow will, in all probability, catch and cut, or otherwise damage, the existing underground installation. The narrow, relatively sharp edges of the vertically oriented coulter wheels may also cut or damage the existing underground installation. It is, therefore, unlikely that such a multi-blade lawn plow could be utilized for installing cable or dripperline irrigation tubing in a turf grass installation having existing underground heating cables, for example.
[0011] It is also not likely that such a multi-blade lawn plow could be utilized for laying dripperline irrigation tubing over the top of an existing irrigation tubing system, supplying traditional sprinkler heads, for example, without prior removal of the existing sprinkler tubing. Attempts to utilize such a multi-blade lawn plow for laying the dripperline irrigation tubing under the surface of the ground on top of the existing tubing feeding traditional sprinkler heads would likely result in the ripper blades catching on the previously installed irrigation tubing, and thereby causing significant damage to the turf grass surface as the existing tubing is pulled along by the ripper blades.
[0012] In addition to the above-mentioned problems with utilizing previously available trenching equipment and lawn plows, such as leaving a visible scar in the turf, and/or cutting, catching, or otherwise damaging previously installed underground facilities, there are further difficulties which must be overcome, in placing underground cable, wire, line, tubing, etc. under a turf surface. For example, cable, of the type utilized in cable television installations, is typically supplied on reels having a relatively small diameter. As a result of the relatively small reel diameter, the cable tends to develop a shape memory which will cause it to attempt to re-coil itself, and, in the process, spring upward out of the ground, if it is not secured by a significant amount of soil pressure. In addition, care must be taken to ensure that the cable is not kinked, damaged by abrasion, cut, or overly strained while being guided into the soil under the turf. In this regard, it is necessary that the bend radii imposed by application equipment be relatively large. As a further complication, the outer surfaces of the cable, and/or tubing, etc., being laid is of a nature which can create substantial frictional force against various structures of an apparatus being utilized for installing the cable and/or tubing. If the frictional force of the laying mechanism, together with any resistance to movement through the apparatus by changing the direction of the cable, is not kept relatively low, the laid cable or tubing will be dragged along with the placement machine, rather than remaining where it is laid down under the turf.
[0013] Maintaining the health and appearance of the turf during and subsequent to installation of the cable or tubing also requires considerable care. It is necessary, for example, to close any opening made for laying the cable or tubing quickly enough, and with properly applied closure force so that exposure of the roots to drying and sunlight, will be minimized, and in such a manner that effective contact of the roots with the surrounding soil will be reestablished following closure of the opening in the turf.
[0014] Through consideration of the above described problems and desires, the inventor of the present invention came to recognize that an improved apparatus, differing substantially from those previously known, would be required. In this regard, the inventor determined that an apparatus and method utilizing equipment for cutting a slice through the turf by action of a rolling element would be preferable to previously known approaches using ripper blades or other types of traditional trenching equipment.
[0015] The inventor further recognized that the nature of the turf itself, when subjected to slicing in an appropriate manner, could be used to significant advantage in developing a new and improved apparatus and method for laying underground cable, wire, line tubing, etc. For example, unlike loose or bare soil, turf tends to spring back, of its own accord, to close any slits cut therein. Turf also tends to hold loosened soil in place, within the roots, rather than allowing the soil to be moved upward onto the surface of the ground.
[0016] The inventor also observed that even a relatively shallow-rooted layer of turf, such as freshly laid sod, provided substantial resistance to having a cable pop back out of the ground, once the turf and soil was compacted back into place over the laid cable or tubing. This was observed to be particularly the case in well-watered turf.
[0017] Having concluded that traditional trenching equipment and methods were unlikely to provide an improved apparatus and method, solving the problems and meeting the desires laid out above, the inventor considered a variety of other solutions, including the use of various structural aspects of equipment utilized for planting seeds through both conventional and reduced or zero tillage methods. Such seed planting equipment has traditionally included the use of one or more rolling coulters, in conjunction with some form of seed feeding tube or structure, and a closure device, for creating shallow V-shaped furrows into which the seed is deposited.
[0018] Such traditional seed-planting-type equipment is not suitable for use, however, or readily adapted for use, in laying underground cables or tubing, under turf.
[0019] As illustrated in FIGS. 7 a and 7 b , the rotating coulter A, or coulters, of seed planting equipment is typically designed for rather shallow penetration into the soil, to provide a V-shaped furrow, which extends only a limited distance D below the surface of the ground G, with the depths of such furrows typically being in the range of 1-4″. The actual depth D will be determined by the particular type of seed being sown, but in general, the seed must be kept within a limited distance of the top of the ground G, in order for the plant emerging from the seed to reach and extend above the surface G of the ground, and begin producing energy through photosynthesis, prior to the nutritional reserves in the seed itself being exhausted. Stated another way, it is necessary to place seed relatively close to the ground surface B, in order for the seeds to germinate properly and survive. The shallow depth D of the V-shaped furrow produced by seed planting equipment is therefore considerably less than the depth, for example 5-10″, at which it is desired to lay underground cable or irrigation tubing.
[0020] In order to create the V-shaped furrow desired for seed planting, a typical seed planting apparatus often utilizes multiple coulters A or disks having a point of contact C with one another that is located at a considerable distance below a center B of the coulter A or disk, with the coulter A or disk angling outward vertically above and horizontally aft of the point of contact C. The point of contact C is often selected to correspond with the ground level G, when the seed planting mechanism is penetrating the soil and forming a V-shaped furrow of the desired depth D.
[0021] As illustrated in FIG. 7 a , this results in the depth D of the V-shaped furrow being substantially less then the radius R of the coulter or disk A. For example, in an apparatus disclosed in U.S. Pat. No. 5,724,902, two disk blades are positioned to form a V-shaped furrow opener with a contact point between the disks 20 and 22 being located substantially at an angle of 35° from the vertical axis (i.e. an angle of 55° down from the horizontal axis passing through the center B of the disk A). One of the disks is smaller, and is mounted vertically with no inclination. The larger of the two disks is inclined 6° along an axis extending through the contact point and the larger disks center, to thus form a compound angle in both the vertical and horizontal planes. By virtue of this arrangement, the tangency or contact point of the two disks is located approximately 1.25″ above the lower edges of the disks, and is thus located at the soil surface when the seeding tool is operated at a planting depth of 1.25″.
[0022] In similar fashion, U.S. Pat. No. 4,493,274, discloses a pair of forming disks having a 14″ diameter and staggered longitudinally by 1″, fore and aft with respect to one another, and the axes inclined so that the included angle is 9.5° and the disks substantially contact each other at a point forward of their axes at about 38° downwardly from the horizontal. By virtue of this arrangement, the 14″ diameter disks create a furrow having a 2.69″ depth, when the point of contact is located at the surface of the soil.
[0023] Because of the point of contact C is located so low on the disks A of prior seed planting equipment, and as a result of the disks A being angled with respect to one another and diverging upward of the point of contact, if such seed planting equipment were forced deeper into the ground, the disks A would cease to function properly, with the individual disks A each cutting a separate slit into the soil at the surface G of the ground, while leaving undisturbed soil in the space between the upwardly diverging edges of the disks A.
[0024] An additional problem preventing the use of prior seed-planting equipment for laying of cable or tubing stems from the fact that such seed-planting equipment is typically designed for use only in relatively loose, non-turf applications. This is true, even for so-called reduced tillage planting equipment. In general, the rotating coulters or disks of a seed-planting apparatus are utilized to cut through the soil, and by virtue of the compound angling of the disks, to remove the soil from the furrow and deposit it onto the ground alongside the furrow, so that the seeds may be placed into the vertex at the bottom of the V-shaped furrow. The seed-planting apparatus typically includes a closure mechanism which moves the soil removed from the furrow back into the furrow, to close the furrow, and firm the soil over the seeds to provide good soil contact with the seed in the furrow and to crush the sides of the furrow to provide a loose layer of soil over the seeds, in the manner described, for example, in U.S. Pat. No. 5,092,255. For proper germination of the seed, soil contact is required, but it is also desirable that the soil not be overly compacted to the point where the plant emerging from the seed will be prevented from reaching the surface of the ground and emerging from the furrow. It will be noted, by those having skill in the art, that the seeds are also individual elements, which are individually placed into the furrow, in stark contrast to a continuous length of cable or tubing which may have a shape memory tending to cause it to coil spring back out of the ground, or otherwise move during the process of being laid into the soil. The loose nature of soil placed back into the furrow by a closure and firming apparatus of a seed planter is thus not designed, and is totally inadequate for compressing the soil over a cable or irrigation tube to the degree required for subsurface cable or tubing installation, particularly when laying cable with a shape memory tending to cause the cable to re-coil and pop out of loosely packed or firmed soil.
[0025] As previously stated, prior seed-planting equipment, including so-called zero-tillage or reduced-tillage planters are not designed for use in turf applications. Trash remaining on the surface of the soil, or clumps of turf will typically result in substantial interference with the operation of typical planting equipment. In order to deal with this problem, it is common practice for prior seed-planting equipment to include various types of trash cutting blades ahead of coulters used for making a furrow in the soil. Such trash cutting devices have included, for example, a wavy-edged coulter wheel for slicing up and disbursing any trash or clumps of turf in the path of the furrow-forming coulter wheel. Such trash cutting and disbursing devices leave unsightly scared areas in turf, and would be totally antethical to the purposes of the present invention. It is noted that in some prior types of planters, used for placing seed into grassy surfaces of a pasture, or the like, single vertical coulters are utilized for cutting a very shallow (less than 1″ deep, for example) furrow into the ground with the seed being deposited therein, as part of an apparatus commonly known as a drill, rather than a planter.
[0026] The seed delivery tubes, of the type used in seed planting equipment, are also typically designed to extend substantially vertically, in order to maximize delivery rate of the seed into the furrow. As disclosed in U.S. Pat. No. 6,347,594 B1, curved delivery tubes tend to cause reduced delivery rate, and are thus typically not utilized in seed planting equipment. Vertical, non-curved, delivery tubes, of the type typically used in seed planting equipment, would be highly undesirable, and essentially unworkable, for feeding cable or tubing. Such a vertically oriented, non-curved configuration, would not lend itself at all to smoothly feeding cable or tubing into the ground in a horizontal direction, behind a coulter wheel or wheels, in a manner which did not create excessive drag within the delivery tube, or other adverse affects such as straining, scraping, or kinking of the cable or tube at the point where it must make a transition from the end of the essentially vertically oriented delivery tube into the horizontal resting position it must assume at the bottom of the furrow created by the coulter wheels.
[0027] Prior seed-planting apparatuses also do not include any structure or device capable of holding a cable or tube stationary within the bottom of a trench or furrow, while the trench or furrow is closed and the soil compacted sufficiently around the cable or tube to prevent it from springing out of the trench or being dragged along with the cable-laying machine. Although some prior seed-planting machines include provisions for precluding having the seed bounce out of the furrow, prior to being covered, these devices would not be useful for holding a cable or tube in place, in accordance with the requirements of the present invention. For example, in U.S. Pat. No. 4,253,412, to Hogenson, a series of plates are joined together by pairs of links and attached behind the discharge end of a seed delivering boot. The plates of Hogenson are not capable of exerting any appreciable downward force for holding a cable or tube in place, in the manner required by a cable laying apparatus. U.S. Pat. No. 5,092,255, to Long et al., and U.S. Pat. No. 5,918,557, to Schaffert, disclose seed boot extensions for reducing seed bounce and to help direct bouncing seeds into the vertex in the bottom portion of a V-shaped furrow. The boot extensions of Long and Schaffert are formed from a flexible material, in order to allow the boot extension to ride up over any chunks of soil within the furrow. The extensions of Long and Schaffert would not apply sufficient force for holding a cable or tube, in accordance with the requirements of the invention. In addition, the extension of Schaffert is supported at a distance above the furrow, for deflecting seed back into the furrow, but does not contact the furrow or seed continuously.
[0028] U.S. Pat. No. 5,673,638, to Keeton, discloses a resilient seed firming attachment for a planting machine having a free end, which is cylindrically shaped, or otherwise configured into a shape such as an inverted V shape substantially conforming to the furrow shape, for positioning seed kernels into the furrow apex. Given the downwardly convex shape of the seed forming attachment of Keeton, it will be apparent, to those having skill in the art, that the seed firming attachment of Keeton would not be usable for holding a cable or tube in place, in accordance with the requirements of the invention. Specifically, the downwardly convex surface of the seed firming attachment of Keeton would not remain positioned on top of the upwardly convex surface of the cable or tubing, but would tend to slide off of the upwardly convex surface of the tubing, or would allow the cable or tubing to slide outward and upward around the firming attachment of Keeton. As a result, the cable or tube would not be held in place, and would likely be pulled upward out of the ground and potentially be wrapped around the firming attachment of Keeton.
[0029] As a final point of inadequacy of prior seed-planting apparatuses to be utilized for, or to be readily adapted for, laying a cable or tube, it will be noted that the furrow closure and firming arrangements of seed-planting apparatuses have typically been positioned at a relatively long distance behind the coulters utilized for making the furrow. This elongated spacing would make it more difficult to achieve the various requirements of the present invention, such as quickly closing the turf, after insertion of the cable or tubing, and compacting the turf and soil over the laid cable or tubing to a degree sufficient to hold it in place within the soil and preclude having the cable or tube being drawn through the soil with the apparatus used for installing the cable or tube under the turf.
[0030] There exists, therefore, a need in the art for a new and improved underground cable, wire, line, tubing, etc., laying apparatus and method that substantially reduces or eliminates the risk of breaking other underground systems, and which does not leave a visible scar in the yard that requires additional care and expense to correct.
BRIEF SUMMARY OF THE INVENTION
[0031] The term “cable”, as used herein, with regard to describing the present invention, is intended to be construed broadly to include not only cable, but also line, wire, hose, fiber optic cable, tubing, etc., or the like, that one may desire to vary under the surface of the ground, and in particular, under the surface of soil having turf growing thereon.
[0032] The present invention provides a new and improved underground cable and the like laying apparatus. More particularly, the present invention provides a new and improved underground cable laying apparatus that is capable of crossing without damaging other underground cables and the like. Further, the present invention provides a new and improved underground cable laying apparatus that does not leave a visibly obvious scar in the lawn under which the cable has been laid.
[0033] In one form of the invention, an underground cable laying apparatus includes a mounting yoke, a pair of angularly displaced turf slicing wheels, and a cable guide tube. The pair of angularly displaced turf slicing wheels are rotatably coupled to the mounting yoke, in such a manner that the turf slicing wheels define a forward contact area therebetween. The cable guide tube is positioned aft of the forward contact area of the turf slicing wheels, with the cable guide tube further having a cable inlet and a cable outlet.
[0034] In an underground cable laying apparatus, according to the invention, each of the angularly displaced turf slicing wheels may define a radius and an outer periphery thereof, and be mounted for rotation about a respective turf slicing wheel axis directed such that, when viewed from either side of the apparatus, the outer peripheries of the turf slicing wheels are substantially super-imposed upon one another vertically and horizontally, with the peripheries coming together at a point of contact in the forward contact zone and disposed substantially horizontally forward of the axes of the turf slicing wheels. The point of contact may be angularly positioned within a range of zero to twenty degrees down from a horizontal extension of the axes of the turf slicing wheels. In some forms of the invention, the point of contact may be vertically positioned substantially horizontally level with the axes, and substantially at ground level when the apparatus is slicing the turf, such that substantially the entire radius of the turf slicing wheels is disposed below ground level in operation. The pair of turf slicing wheels may be angularly displaced relative to one another along a vertical axis of the mounting yoke, in such a manner that the forward contact area is disposed substantially below the point of contact, and the outer peripheries of the turf slicing wheels diverge below the forward contact area, in such a manner that the slit in the turf has a defined horizontally extending bottom width thereof, rather than being substantially V-shaped and terminating in a vertex of the V-shape at the bottom of the slit.
[0035] In accordance with one embodiment of the present invention, the underground cable laying apparatus includes a pair of angularly displaced turf slicing wheels that slice and separate the turf under which the underground cable is to be laid. A cable feed tube is positioned between the turf slicing wheels to guide the underground cable between the turf slicing wheels. A cable feed guide wheel is positioned rearward of the opening of the cable feed tube to aid in the positioning and proper laying of the underground cable in a smooth fashion. In a preferred embodiment, the leading edge of the cable feed tube includes a feed tube support extension member to provide additional rigidity and stabilization of the cable feed tube placement while laying the underground cable. A cable guide wheel cleaning mechanism can be applied to prevent the build up of soil on the guide wheel. A cable guide may also be employed at an insertion end of the cable feed tube.
[0036] In a preferred embodiment of the present invention, the underground cable laying apparatus also includes turf closing wheels operative to close the slit in the turf into which the cable has been laid. These turf closing wheels are carried by a turf closure housing that is pivotably coupled to the mounting yoke of the cable laying apparatus. Preferably, the turf closing wheels are spring loaded by a turf follower spring within the turf closure housing. This turf follower spring is preferably adjustable to vary the spring load tension on the closing wheels based upon the type of lawn under which the cable is to be laid. Positioning detents or blocks limit the downward travel of the turf closure housing under action of the turf follower spring.
[0037] In a preferred method of laying underground cable, and the like, in accordance with the teachings of the present invention, a thin slice in the turf is opened by the turf slicing wheels. Preferably, the soil is moist, either from natural sources or from a step of watering. Cable or the like is then positioned within the open slice in the turf. Preferably, this step is accomplished by guiding the cable to be laid into the slice in the turf. This step of guiding may be accomplished in a preferred embodiment through the use of a cable feed tube having at an aft end thereof a cable guide, which may take the form of a wheel, roller, guide bar, etc., configured for maintaining the cable in the proper position within the slice in the turf.
[0038] A cable guide, according to the invention, may take a variety of forms having a downwardly facing, non-convex surface thereof adapted for contacting the cable. Such a non-convex contact surface may be flat, concave, and may include a groove therein for partial receipt within the groove of the cable. Alternatively, or in addition, the cable guide may be formed of a flexible material having the ability to conform to the upwardly convex upper surface of the cable. In some forms of the invention, the cable guide may take the form of a flexible segment of tubing, having a bore therein for passage therethrough of the cable, with a lower end of the cable guide being directed, or flexibly movable by virtue of contact with the bottom of the slice in the turf to expel the cable in a substantially horizontal direction into the bottom of the slice in the turf.
[0039] Preferably, the method of laying underground cable in accordance with the present invention also includes the step of closing the slice in the turf once the cable has been laid therein. This step may be performed by providing a closing force in a direction to close the slit. Preferably, this closing force is applied to either side of the slit to preclude damage to the turf under which the cable has been laid.
[0040] Through the method of the present invention, damage to other underground systems, such as invisible fencing, other cables or wires, or sprinkler systems is precluded or the likelihood of such is significantly reduced. This is so because the rolling action of the turf slicing wheels does not snag or otherwise cut the other underground wires as occurs within the prior art methods of laying cable. As such, a significant advantage is realized through the use of the present invention for laying underground cable and the like. Similarly, by opening a thin slice in the turf which is then closed by applying a force to either side of the slice, the unsightly scarring of the turf that commonly results with prior art methods is also precluded.
[0041] Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
[0043] FIG. 1 is a side view illustration of an embodiment of an underground cable laying apparatus constructed in accordance with the teachings of the present invention;
[0044] FIG. 2 is a cross-sectional illustration of the cable laying apparatus of FIG. 1 ;
[0045] FIG. 3 is a frontal isometric view of the cable laying apparatus of FIG. 1 ;
[0046] FIG. 4 is a rear isometric illustration of the cable laying apparatus of FIG. 1 ;
[0047] FIG. 5 is a cross-sectional illustration of the cable laying apparatus of FIG. 1 shown in operation laying an underground cable;
[0048] FIG. 6 is a partial isometric illustration of a cable feed guide wheel assembly of the cable laying apparatus of FIG. 1 ;
[0049] FIGS. 7 a and 7 b are schematic illustrations of a typical prior art seed planting mechanism, having one or more coulters arranged for cutting a V-shaped furrow in the earth, for deposition of seeds therein, with the illustrations further showing that the depth of such a V-shaped furrow below ground level is considerably less than a radius of the coulter;
[0050] FIGS. 8 a - 8 c illustrate the manner in which the invention is utilized for cutting a non-V-shaped slit into turf-covered soil, with a pair of angled coulters, in accordance with the invention, in such a manner that the depth of the non-V-shaped slit is significantly larger than the depth of the V-shaped furrow formed by prior art devices and methods, with the depth of the slit, according to the invention, being substantially equal to the radius of the angled coulters;
[0051] FIGS. 9-11 illustrate several alternate embodiments of a cable feed guide wheel, according to the invention, as applied in the exemplary embodiment of the cable laying apparatus shown in FIGS. 1-6 ;
[0052] FIGS. 12 and 13 illustrate an alternate embodiment of a cable feed guide, according to the invention, having a downwardly opening substantially convex surface thereof for contacting an upper convex surface of a cable or tube being installed into turf-bearing soil;
[0053] FIG. 14 illustrates an alternate embodiment of the exemplary embodiment of the cable laying apparatus of FIGS. 1-6 , which includes a cable feed tube having a flexible outlet;
[0054] FIG. 15 illustrates an alternate embodiment, according to the invention, of the apparatus shown in FIG. 14 , with the apparatus of FIG. 15 including a flexible cable feed tube liner and extension; and
[0055] FIG. 16 illustrates an alternate embodiment, of the exemplary embodiment of the cable laying apparatus shown in FIGS. 1-6 , with the alternate embodiment of FIG. 16 illustrating a pair of turf closing wheels having a flat, angled, contact surface thereof, as compared to the rounded contacting surfaces of the turf closing wheels shown in FIGS. 1-6 .
[0056] While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0057] Turning now to the drawings, there is illustrated in FIG. 1 an exemplary embodiment of an underground cable laying apparatus 10 constructed in accordance with the teachings of the present invention. In the interest of brevity, the term cable will be used throughout this description to include cable, line, wire, hose, fiber optic cable, tubing, etc., that one may desire to bury under the surface of the ground.
[0058] As may be seen from this FIG. 1 , the underground cable laying apparatus 10 includes a mounting yoke 12 on which is mounted a pair of turf slicing wheels 14 , 16 (see FIG. 2 ). The mounting yoke 12 includes mounting receptacles, for example receptacles 18 , 20 that are positioned and configured to allow the apparatus 10 to be mounted to a truck or other vehicle that will be used in the cable laying process. As such, the particular configuration and placement of the mounting receptacles may vary in particular embodiments based upon the type of vehicle used in the cable laying process. Indeed, the position and configuration of the mounting receptacles may accommodate the usage of an intermediate mounting or other equipment, for example a shaker unit, that may be directly mounted to the vehicle.
[0059] In addition to the turf slicing wheels 14 , 16 , a turf closing mechanism, for example turf closing wheels 22 , 24 carried on a turf closure housing 26 , is pivotably mounted to the yoke 12 by the closure assembly mounting arms 28 , 30 . The turf closure housing 26 may include positioning detents 32 , 34 , blocks, shoulders, or other movement limiting structure to prevent the turf closure wheels 22 , 24 and their associated housing 26 from pivoting downward beyond a desired location. However, as will be discussed more fully below, the upward pivoting of the housing 26 is preferably unimpeded within a range to allow the turf closing wheels 22 , 24 to follow the contours of the soil into which the cable has been laid.
[0060] The underground cable laying apparatus also includes a cable feed tube 36 used to guide the cable to be laid through the apparatus 10 . To facilitate this operation, the cable feed tube 36 includes a cable inlet 38 at a forward location of the apparatus 10 that receives the cable from the spool or other holding device. If desired, the cable feed tube 36 may also include a cable guide 40 positioned above inlet 38 . This cable guide 40 may have a diameter larger than the inlet 38 to allow for some play in the cable before it enters inlet 38 . The cable feed tube 36 leads down between the turf slicing wheels 14 to a position rearward of the leading edges thereof. At this position the cable feed tube outlet 42 dispenses the cable to be laid in the slice in the turf which has been created by the turf slicing wheels 14 , 16 . At this outlet 42 a feed tube support extension member 44 may be provided to add additional stability and support for the end of the cable feed tube 36 .
[0061] FIG. 2 provides a cross-sectional illustration of the underground cable laying apparatus 10 illustrated in FIG. 1 . As may be seen from this cross-sectional illustration, the positioning of the cable feed tube 36 preferably provides a curved path through which the cable may be directed through the apparatus. In this way, the possibility of snagging or chafing the exterior of the cable to be laid is greatly reduced over prior systems that terminated in an outlet perpendicular to the trench into which the cable was to be laid. To further aid in the smooth and proper positioning of the cable within the slice in the turf created by the turf slicing wheels 14 , 16 , the apparatus 10 of the present invention may also include a cable feed guide, such as wheel 46 . This cable feed guide wheel 46 is positioned in proximity to the outlet 42 to further place the cable in the proper position in the slice in the turf without scraping or otherwise damaging the exterior surface of the cable. Indeed, in embodiments that utilize this cable feed guide the cable feed tube may be straight with an outlet perpendicular to the slit as the cable feed guide will ensure a smooth directional change in the cable without damage thereto. To prevent the buildup of soil within the groove 48 of the cable feed guide wheel 46 , a groove cleaning rod 50 may be provided. This groove cleaning rod 50 is positioned within the groove 48 of the cable feed guide wheel 46 in such a manner so as to prevent or reduce the amount of buildup of soil within the groove so that the cable being dispensed may be gently guided within the groove 48 to its proper position within the slit in the turf.
[0062] As may also be seen from this cross-sectional illustration of FIG. 2 , the turf closure housing 26 is spring-biased to its downward position by a turf follower spring 52 . Preferably, this turf follower spring 52 is coupled between the mounting yoke 12 via a spring mount 56 and the rearward wall 54 of the turf closure housing 26 , rearward of the pivot point 58 . The amount of force that the turf closure wheels 22 , 24 apply to the turf may be adjusted by varying the spring tension. In the embodiment illustrated in FIG. 2 , this spring tension variation may be accomplished by adjusting spring tension nut 60 . The adjustment of this spring tension is facilitated by the positioning detents 32 , 34 as they prevent further downward pivoting of the turf closure housing 26 through their engagement with the closure assembly mounting arms 28 , 30 .
[0063] As may be seen from the frontal isometric illustration of FIG. 3 , the turf slicing wheels 14 , 16 are angularly positioned relative to one another. Preferably, they are angularly positioned relative to both the horizontal and vertical axis of the mounting yoke 12 . That is, the turf slicing wheels 14 , 16 are positioned such that they contact each other at a contact point 61 along an area 62 , and are elsewhere displaced from one another. This displacement between the turf slicing wheels 14 , 16 preferably increases both along a horizontal and vertical axis such that a small slice is initiated in the turf by the forward contact area 62 , and is widened along both the horizontal and vertical axes as the apparatus 10 is moved through the turf. In this way, the turf defining the slit is displaced both outwardly and upwardly to accept the cable to be laid therein. With such a displacement of the turf defining the slit, the turf closure wheels 22 , which provide an angular closing force on either side thereof, may then fully close the slit without damage to the turf. Indeed, in most situations the closure of the slit is complete without leaving a residual scar in the turf whatsoever. As may be seen from this frontal view of FIG. 3 , the angular displacement of the turf closure wheels 22 , 24 is preferably greater than the angular displacement along the same axis of the turf slicing wheels 14 , 16 .
[0064] As shown in FIGS. 3 and 8 a , in the exemplary embodiment of the underground cable laying apparatus 10 , each of the angularly displaced turf slicing wheels 14 , 16 defines a radius R and an outer periphery thereof, and is mounted for rotation about a respective turf slicing wheel axis 17 , 19 directed such that, when viewed from either side of the cable laying apparatus 10 , (as depicted in FIG. 1 , for example) the outer peripheries of the turf slicing wheels 14 , 16 are substantially super-imposed upon one another vertically and horizontally, with the peripheries coming together at the point of contact 61 in the forward contact zone 62 and disposed substantially horizontally forward of the axes 17 , 19 of the turf slicing wheels 14 , 16 .
[0065] As illustrated in FIG. 8 a , by virtue of the above described attachment of the turf slicing wheels 14 , 16 , in the exemplary embodiment of the cable laying apparatus 10 , the point of contact 61 is angularly positioned within a range of zero to twenty degrees down from a horizontal extension of the axes 17 , 19 . Specifically, as shown in FIGS. 3 and 8 a , the turf slicing wheels 14 , 16 , of the exemplary embodiment of the apparatus 10 , are operatively attached to the mounting yoke 12 , by a pair of bearings located within bearing hubs 13 , 15 attached to the turf slicing wheels 14 , 16 . In the exemplary embodiment, the contact point 61 is horizontally disposed slightly below the outer periphery of the hubs 13 , 15 , which results in the point of contact 61 being vertically positioned substantially horizontally level with the axes 17 , 19 , and being positioned substantially at ground level G when the apparatus is slicing the turf, such that substantially the entire radius R of the turf slicing wheels 14 , 16 is disposed below the ground level G, during operation of the cable laying apparatus 10 , as illustrated in FIG. 8 a.
[0066] In FIG. 8 a , the turf slicing wheels 14 , 16 are illustrated with a scale diameter of 14″, and a diameter of the hubs ( 13 , 15 ) of 3″. When the turf slicing wheels 14 , 16 are lowered into the ground to a point where the hubs 13 , 15 are positioned just above the surface G of the ground, an embodiment of the invention having 14″ diameter turf slicing wheels ( 14 , 16 ) and 3″ diameter hubs 13 , 15 , will extend into the ground to a depth D substantially equal to the radius R of the wheels 14 , 16 minus the radius r of the hubs 13 , 15 , such that the resultant depth D of the slice in the turf will have a depth of approximately 5½″ below the surface of the ground G. When operated in this manner, the point of contact 61 of a 14″ diameter turf slicing wheel, with a 3″ diameter hub, will be located at an angle 21 of approximately 13° downward from a horizontal extension of the axes 17 , 19 , when the contact point 61 is positioned at the ground level G.
[0067] For purposes of comparison, the diameter of the coulter A in the prior art seed-planting apparatus, shown in FIG. 7 a , and the diameter of the angularly displaced turf slicing wheels 14 , 16 , of the exemplary embodiment of the invention shown in FIG. 8 a are illustrated to the same scale. By comparison of FIG. 7 a and 8 a , it will be readily understood that the positioning of the contact point 61 of the present invention is substantially different than the position of the contact point C in seed-planting apparatuses. In the present invention, the depth D of the slice in the turf is substantially equal to the radius R of the turf slicing wheels 14 , 16 . In the exemplary embodiment of the underground cable laying apparatus 10 , having the turf slicing wheels 14 , 16 attached to the mounting yoke 12 by hubs 13 , 15 having a 3″ diameter, the depth D is reduced only by the relatively small radius r of the hubs 13 , 15 . In other embodiments of the invention, having smaller hubs, or essentially hub-less attachments of the turf slicing wheels to a mounting yoke, the turf slicing wheels may be lowered even further into the ground, to a point where the contact point 61 between the turf slicing wheels 14 , 16 lies virtually at ground level G, with the resultant depth D of the slice in the turf having a depth virtually identical to the radius R of the turf slicing wheels 14 , 16 .
[0068] By way of comparison, as shown in FIG. 7 a , and as previously discussed in the Background section above, the point of contact C in a seed-planting apparatus is typically positioned much farther below the axis B of the a coulter of the seed-planting apparatus, such that the point of contact C is typically located at a much larger angle E down from the horizontal extension of the axis B than is utilized in practicing the present invention. For example, as previously stated above, seed-planting apparatuses typically position the point of contact C at an angle E of 35° to 55° below the horizontal extension of the axis B, such that, when the seed-planting apparatus is operated with the point of contact C located substantially at ground level, the depth D of the furrow formed will be substantially less then the radius R of the coulter of the seed-planting apparatus.
[0069] As shown in FIG. 8 b , by virtue of the pair of turf slicing wheels 14 , 16 , of the exemplary embodiment 10 , being angularly displaced relative to one another along a vertical axis of the mounting yoke, in the manner illustrated in FIGS. 3 and 8 b , the forward contact area 62 extends substantially downward from the point of contact 61 , with the outer peripheries of the turf slicing wheels 14 , 16 diverging below the forward contact area 62 , in such a manner that the slit in the turf has a defined horizontally extending bottom width W thereof, as shown in FIGS. 8 b and 8 c . The shape of the slit in the turf, created by the turf slicing wheels 14 , 16 of the exemplary embodiment of the apparatus 10 , according to the invention, thus has a substantially different shape than the V-shaped furrow of the type created by seed-planting equipment, as illustrated in FIG. 7 b . For purposes of illustration, FIGS. 7 b , 8 b and 8 c are all shown in the same relative scale, with the depth D of the slit shown in 8 b and 8 c as created according to the present invention being illustrated at a relative depth D of approximately 6″ below the surface of the ground G and the depth D of the V-shaped furrow of FIG. 7 b being illustrated at a representative depth of approximately 3″.
[0070] A comparison of FIGS. 8 b and 8 c with FIG. 7 b also serves to illustrate other differences between the slit and turf created through practice of the present invention, as compared to the V-shaped furrow created in non-turf bearing soil of the type created by typical seed-planting equipment. As shown in FIG. 7 b , seed planting apparatuses typically remove soil from the V-shaped furrow and deposit it on top of the ground G in the process of forming the V-shaped furrow. In contrast, in the slit in the turf created through practice of the present invention, the turf is neatly sliced by the forward contact area 62 of the turf slicing wheels 14 , 16 , and the turf is separated far enough, as the turf slicing wheels 14 , 16 move forward, to allow the cable 68 to be inserted aft of the turf slicing wheels 14 , 16 . Because of the resilient nature of the turf, soil from the slit in the turf is not brought up and deposited on top of the ground, as is the case in seed-planting apparatuses. The soil is held in place by the turf and its roots, substantially within the slice in the turf. As illustrated in FIG. 8 b , as the turf cutting wheels 14 , 16 move through the soil, the initial slit is widened by the angled position of the turf slicing wheels 14 , 16 , and although the turf tends to rise upward somewhat behind the hubs 13 , 15 , soil is not removed from the slit and deposited on top of the ground.
[0071] In practicing the invention, it is preferable that the turf be well watered, to enhance its capability to be spread apart, without having dry loose dirt particles brought up onto the surface of the ground, and also to be more readily compacted over the cable, after the cable has been deposited in the bottom of the slice in the turf.
[0072] As may be seen from the rear isometric view of FIG. 4 , the cable feed guide wheel 46 is positioned to dispense the cable to be laid in the center of the slit in the turf created by turf slicing wheels 14 , 16 , prior to the application of the closing force on the slit by turf closing wheels 22 , 24 .
[0073] In operation, the apparatus 10 is lowered by the vehicle so that the contact area 62 of the turf slicing wheels contacts the upper surface 64 of the turf with the contact point 61 located substantially at the surface G of the ground. As the vehicle travels across the turf, rotation of the turf slicing wheels 14 , 16 creates the slit in the turf that preferably opens both horizontally and vertically to receive the cable to be laid therein. Since the turf closure wheels 22 , 24 are displaced horizontally from one another by an amount greater than the maximum slit width, the wheels 22 , 24 ride on the outside of the slit and provide a downward and inward closure force to effectuate a closure of the slit once the cable has been laid therein. The amount of force applied on the sides of the slit is dependent upon the setting of the spring force of the turf follower spring 52 as discussed above. Also, due to the close proximity of the turf closure wheels 22 , 24 to the rearward edge of the turf slicing wheels 14 , 16 , closure of the slit into which the cable has been laid occurs in very close proximity to the point where the cable leaves the cable feed guide wheel. In this way, the proper positioning of the cable within the slit is ensured. With prior trencher systems, coils in the cable may allow the cable to rise above the bottom of the trench before the soil is placed back in the trench, resulting in areas where the cable is shallower than in others, which may result in uncovering of the cable and forming a hazardous condition.
[0074] As discussed briefly above, to ensure that the cable is properly positioned within the slit in the turf, in the exemplary embodiment of the cable laying apparatus 10 , a cable feed guide wheel 46 is used. However, one skilled in the art will recognize that a roller or other guide mechanism may be used at this location such as the alternate embodiment discussed below in relation to FIGS. 9-15 , to provide proper placement and smooth transitioning of the cable from the cable feed tube to its position in the bottom of the slit.
[0075] In an embodiment that utilizes a cable feed guide wheel 26 , such as that illustrated in FIG. 6 , the provision of a guide wheel cleaning mechanism may be desired. As introduced above, this cleaning mechanism may include a cable groove cleaning rod 50 that rides in the groove 48 of the cable feed guide wheel 46 . As the wheel rotates while dispensing the cable 68 any dirt or other debris that may accumulate within groove 48 will be displaced by the cleaning rod 50 . Similarly, the cable feed guide wheel housing 70 may include wheel edge scrapers 72 , 74 that clean the sides of the wheel 46 and prevent the accumulation of soil or other debris, which may affect the ability of the wheel 46 to rotate.
[0076] In practicing the invention, a cable feed guide may take a variety of forms other than the grooved cable guide wheel 46 described above. For example, FIG. 9 illustrates a cable guide wheel or roller 80 which does not include the groove 48 of the embodiment of the cable feed guide wheel 46 . Generally speaking, so long as the cable feed guide element used in practicing the invention presents a non-convex, i.e. flat or downwardly opening concave surface, acting against the upper surface of the cable 68 , the cable feed guide will serve to hold the cable 68 in proper position in the bottom of the slit prior to the slit being closed by the turf closing wheels 24 , 26 .
[0077] FIGS. 10 and 11 illustrate alternate embodiments of a cable guide wheel or roller ( 46 , 80 ) formed from a material, or configured in a manner that the surface of the wheel or roller may deform about the upper surface of the cable 68 . Cable guide wheels or rollers formed from a resilient material provide an additional advantage in that they tend to inherently shed dirt from the outside surfaces thereof, as the wheel or roller flexes.
[0078] FIGS. 12 and 13 illustrate an alternate embodiment of the invention, in which the feed tube 36 includes a static cable feed guide 82 , attached to the cable feed guide tube outlet 42 , for directing the cable 68 in a horizontal direction for discharge into the slit in the turf. As best seen in FIG. 13 , the static cable feed guide 82 defines a downwardly opening substantially concave surface 84 adapted for contacting the upper surface of the cable 68 , with the downwardly opening concave surface 84 being configured to preclude having the cable 68 escape from the concave surface 84 .
[0079] FIG. 14 illustrates an alternate embodiment of a cable feed guide 86 , according to the invention, in the form of a flexible tubular shaped extension of the cable feed tube 36 having a bore therein, for directing the cable 68 into the slit in a horizontal direction, while the flexible tube extension 86 is being bent into a horizontal arc by contact between the bottom of the flexible tube extension and the bottom surface W of the slit in the turf. For such an embodiment, it is contemplated that the flexible tube extension may be made from a polymer or composite material, having sufficient bending stiffness to hold the cable 68 securely in the bottom of the slit in the turf.
[0080] FIG. 15 illustrates a variation of the alternate embodiment of the invention shown in FIG. 14 , in which an underground laying apparatus 10 , according to the invention, includes a flexible tube extension 88 which extends through the full length of the cable feed tube 36 , and is secured therein by a projecting flange 90 , at the inlet to the cable feed tube, with a portion of the flexible tube 88 extending beyond the outlet end of the cable feed tube 36 . With this embodiment of the invention, the flexible feed tube extension provides a continuous smooth surface from the inlet to the outlet of the cable feed tube, in a form that may be readily replaced, as the flexible tube extension becomes worn. Alternatively, a selection of different flexible tube extensions 88 , each having, respectively, bores thereof sized and/or appropriately shaped to accommodate various sizes and types of cable, wire, tubing, etc. to be installed with the cable laying machine 10 may be provided, to tailor the configuration of the feed tube 36 and cable feed guide to the particular type of cable and/or tube being installed.
[0081] FIG. 16 illustrates an alternate embodiment of the closure wheels 22 , 24 of the exemplary embodiment of the underground cable laying apparatus 10 . In the alternate embodiment of the turf closing wheels 22 , 24 , shown in FIG. 16 , the outer periphery of the turf closing wheels 24 , 26 is configured to form a wide, flat area of contact with the turf, which may be more advantageous than the more rounded shape of the embodiment of the turf closing wheels 22 , 24 shown in FIG. 4 , for certain conditions of the turf, such as when the turf is relatively wet or somewhat sparse. In other embodiments of the invention, the turf closing wheels may have yet other configurations. Turf closing structures, having appropriate configurations other than wheels may also be used in practicing the invention, in combination with other aspects of the invention.
[0082] The underground cable laying apparatus of the present invention provides significant advantage through the use of the turf slicing wheels, particularly in installation locations where other installed underground systems may be in place, and where a visible scar in the turf resulting from the cable laying operation is not desired. In the first instance, the apparatus of the present invention provides a significant advantage through the use of the rotating turf slicing wheels for providing the slit in the turf into which the cable is to be laid. Since the turf slicing wheels rotate, there is a significantly reduced likelihood of damage to other installed underground systems as results from typical trenchers. Specifically, the rotating turf slicing wheels will not snag and pull the other underground systems which it encounters, and instead merely rolls over them while leaving them in place. This non-damaging contact with previously installed underground systems is aided by the angular relationship between the two turf slicing wheels. That is, the relative angular displacement of the turf slicing wheels forms a contact portion 62 that slices the top layer of the turf, but then separate from one another at all other locations. As a result, contact with previously installed underground systems often occurs at a position where the turf slicing wheels 14 , 16 are separated from one another, but are still in close proximity. As a result, the contact force is dispersed at the two contact points with each of the individual turf slicing wheels. Since these wheels are most likely still in close proximity, the contact force is not sufficient to damage the exterior surface of the previously installed underground system.
[0083] In the second instance, unlike blade type systems that gouge a slit into the turf, and trencher systems that completely remove the soil to form a trench, the underground cable laying apparatus of the present invention merely opens a slit in the turf, which is quickly reclosed once the cable has been placed therein. The angular placement of the turf slicing wheels ensures a narrow slit is initiated in the turf, is slightly widened to allow placement of the cable therein, and then is immediately reclosed by providing angular downward and inward force on the sides of the slit opened by the turf slicing wheels. As a result, it is nearly impossible to observe where the slit was opened in the turf once the cable has been laid therein. This is especially true when the turf is moist, or has been recently watered.
[0084] Experience has shown that the present invention may be practiced in a wide variety of soil types and turf conditions. It is preferred, when practicing the invention, that the turf be generally well watered, so that the soil is moist down to the depth D of the slit below the surface of the ground G. Accordingly, it may be desirable in practicing the invention, to water the turf prior to installing the cable therein.
[0085] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
[0086] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
[0087] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
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Presented is an underground cable laying apparatus that leaves virtually no visible scar in the turf under which cable, wire, line, hose, etc. is laid. The apparatus utilizes a pair of angularly displaced turf slicing wheels to slice and separate the turf forming a slit into which cable may be laid. A cable guide tube and roller properly place the cable within the slit. A pair of turf closure wheels close the slit in close proximity to the release point of the cable to ensure proper placement of the cable. The slit in the turf is gently and completely closed over the cable, leaving virtually no visible scar within the turf to upset the aesthetic beauty of a lawn. Further, the configuration and rolling action of the turf slicing wheels ensures that other underground cables will not be damaged if inadvertently encountered.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the full benefit of U.S. Provisional Patent Application Ser. No. 61/991,610, filed May 11, 2014, and titled “METHODS AND APPARATUS FOR INITIATING COMMUNICATION BETWEEN PARTIES”, the entire contents of which are incorporated herein by reference.
FIELD OF DISCLOSURE
[0002] This disclosure relates to methods and apparatus for safely and securely initiating communication between parties. More particularly, the present disclosure relates to utilizing a logo as an indication of availability and as a means for a second party to show interest without requiring an exchange of personal information.
BACKGROUND
[0003] Traditionally, when a party wanted to place a good on the market, such as a car or a property, the party placed an ad in a newspaper or posted signs on or near the product. The ad or signs would likely contain some personal contact information, which would allow an Interested Party to contact the seller. The parties would then arrange to meet and discuss the terms of the sales, and if the terms were agreeable to both parties, they may conduct a transaction.
[0004] More recently, websites embody a virtual “Want Ad” formerly seen in printed publications. For example, websites such as Craigslist or eBay allow sellers to reach a broader audience and, in some cases, provide a secure payment platform. However, the transactions still typically involve some exchange of personal information and/or a risky meeting arrangement.
[0005] In addition, according to traditional methods of marketing and exchange, a car or other property needed to be actively listed and offered sale. A potential customer would need to access a DMV or property records in order to ascertain an owner of a care or property not listed for sale.
[0006] What is needed therefore is a convenient, safe, and effective way to convey availability of a product and a responsive interest in the product.
SUMMARY
[0007] Accordingly, the present disclosure provides methods and device to utilizing a logo as an indication of availability and as a means for a second party to show interest without requiring an exchange of personal information, and therefore, overcomes the disadvantages of prior art as briefly described above.
[0008] A system of one or more computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination thereof installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions. One general aspect includes a computing apparatus capable of facilitating communication between an advertiser and an Interested Party, where the computing apparatus includes: a communications network access device for accessing a server in logical communication with a communications network; and executable software stored on the communications network access device and executable on demand.
[0009] The computing also enables the receipt of identification information associated with an available product, service or person, where an owner is associated with the available product, service or person. The computing also includes transmitting the identification information to an external server. The computing also includes receiving profile information from the external server, where the profile information is associated with the transmitted identification information. The computing also includes presenting the profile information to a prospective party. The computing also includes prompting the prospective party to respond to the presented profile information. The computing also includes receiving the response from the prospective party, where the response is indicative of interest or lack of interest in the available product, service or person. Other examples of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.
[0010] Implementations may include one or more of the following features. Implementations may include the apparatus where the identification information is logically embedded in a logo configured to be placed on or proximate to the available product, service or person. Implementations may include the apparatus where the logo further includes a tag configured to wirelessly transmit the identification information to the network access device. Implementations may include the computing apparatus where the communications network access device is further caused to transmit energy to the tag. Implementations may include the computing apparatus where the identification information is logically embedded in a readable code portion of the logo. Implementations may include the computing apparatus where the communications network access device is further caused to notify the prospective party of a receipt of the identification information. Implementations may include the computing apparatus where the response indicates interest in the available product, service or person, and where a prospective party becomes an Interested Party, and where the communications network access device is further caused to initiate communication between the Interested Party and the owner. Implementations may include the computing apparatus where the communication between the Interested Party and the owner further causes the communications network access device to: transmit the response to the owner; receive a first communication from the owner; present the first communication to the Interested Party; receive a second communication from the Interested Party; and transmit the second communication to the owner. Implementations may include the computing apparatus where the first or the second communication includes a transaction offer for the available product, service or person between the owner and the Interested Party. Implementations may include the computing apparatus where the first or the second communication includes an acceptance of the transaction offer for the available product, service or person. Implementations may include the computing apparatus where the communications network access device is further caused to commence a commercial transaction based on the transaction offer.
[0011] Methods may additionally include the steps of: presenting a data stream to an operator of a computing device, where the presenting of the data stream identifies to the operator of the computing device an interest prompt and a contact information data segment; and collecting a user response from the operator of the computing device; transmitting a data stream to another computing device, where the application software operating on the other computing device may process the data stream; and communicating to an operator of the other computing device a response, where the response is based upon the information in the data stream.
[0012] The method may include examples where an identification device includes an image. An example may include the method where the image includes a logo associated with a first entity, where the first entity provided the application software operating on a first computing device. Additional examples may include the method where the image includes a modified logo associated with a second entity, where the second entity is associated with the first user. Additional examples may include the method where the identification device includes a wireless communication device. Additional examples may include the method wherein the wireless communication device includes an Radio Frequency Identification (RFID) and the method wherein the wireless communication device includes a bluetooth enabled device. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.
[0013] One general aspect includes a method of initiating communication between at least two parties, the method including the steps of: providing an identification device to a first user, where the identification device contains a unique identifier; providing application software to a second user, where the application software may be operated on a first computing device, where the first computing device may also interact with the identification device to extract the unique identifier; receiving on a second computing device a communication originating from the first computing device, where the communication signals an interest prompt from the application software operating on the first computing device; extracting the unique identifier from the communication; accessing a database, where the database contains profile information, where at least a portion of the profile information may be associated with the unique identifier; retrieving a contact information data segment associated with the unique identifier from the database; and transmitting a data stream to a third computing device, where the data stream contains the interest prompt and the contact information data segment, where the third computing device is associated with the first user. Other examples of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.
[0014] Implementations may include one or more of the following features. Implementations may include the method additionally including the steps of: presenting the data stream to an operator of the third computing device, where the presenting of the data stream identifies to the operator of the third computing device the interest prompt and the contact information data segment; and collecting a user response from the operator of the third computing device; transmitting a data stream to the first computing device, where the application software operating on the first computing device may process the data stream; and communicating to an operator of the first computing device a response, where the response is based upon the information in the data stream. Implementations may include the method where the identification device includes an image. Implementations may include the method where the image includes a logo associated with a first entity, where the first entity provided the application software operating on the first computing device. Implementations may include the method where the image includes a modified logo associated with a second entity, where the second entity is associated with the first user. Implementations may include the method where the identification device includes a wireless communication device. Implementations may include the method where the wireless communication device includes an rfid. Implementations may include the method where the wireless communication device includes a bluetooth enabled device. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.
[0015] The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. The accompanying drawings that are incorporated in and constitute a part of this specification, illustrate several examples of the disclosure and, together with the description, serve to explain the principles of the disclosure: Other features, objects, and advantages of the disclosure will be apparent from the description, drawings and the claims herein.
DESCRIPTION OF THE DRAWINGS
[0016] The foregoing and other features and advantages of the disclosure will be apparent from the following, more particular description of preferred examples of the disclosure, as illustrated in the accompanying drawings.
[0017] FIG. 1A illustrates an exemplary embodiment of a logo affixed to a building, wherein the logo may be indicative of property availability.
[0018] FIG. 1B illustrates an exemplary embodiment of a logo affixed to a shop, wherein the logo may be indicative of product availability within the shop.
[0019] FIG. 1C illustrates an exemplary embodiment a logo affixed to a bumper of a vehicle, wherein the logo may indicate that the car may be for sale.
[0020] FIG. 1D illustrates an exemplary embodiment including wearable tags, wherein the tag may be indicative of availability.
[0021] FIG. 2A illustrates an exemplary embodiment of a logo.
[0022] FIG. 2B illustrates an alternate exemplary embodiment of a logo.
[0023] FIG. 3 illustrates an exemplary system for accessing product information of an available product.
[0024] FIG. 4 illustrates an exemplary system for receiving identification information of an available product.
[0025] FIG. 5 illustrates an exemplary system for accessing product information of multiple available products.
[0026] FIG. 6 illustrates an exemplary processing and interface system.
[0027] FIG. 7 illustrates exemplary method steps for wirelessly receiving profile information, wherein the identification information may be received through a wireless transmission from a tag on a logo.
[0028] FIG. 8 illustrates exemplary method steps for wirelessly receiving profile information, wherein the identification information may be retrieved through capture of a code or image of a logo.
[0029] FIG. 9 illustrates exemplary method steps for initiating direct communication between a profile owner and an Interested Party.
[0030] FIG. 10 illustrates exemplary method steps for transmitting profile information to an external device.
[0031] FIG. 11 illustrates exemplary method steps for allowing direct communication between a profile owner and an Interested Party.
DETAILED DESCRIPTION
[0032] The present disclosure relates generally apparatus and systems for facilitating communications between parties in controlled manners. Generally, a user operates network access device, such a smart phone is used to transmit a unique identifier affixed to an item. The smart phone will then receive back information relating to the item and may also be used to communicate to a person associated with the item. Some examples may include the person associated with the item communicating directly to the user.
Glossary
[0033] As used herein the following terms will have the following associated meaning:
[0034] Available: as used herein describes a person or product that may be on the market. For example, an available product may be on the market for sale, rent, lease, or other means of conveyance. Similarly, an available person may be on the market for socializing, dating, or hiring, for example.
[0035] Tag: as used herein refers to a detectable marker that may be embedded in a logo or may be attached separately to an available good or person. In some examples, a tag may comprise embedded information detectable though RFID, Bluetooth, or Wi-Fi, as non-limiting examples.
[0036] Logo: as used herein refers to an image that indicates availability of a good or person, and wherein the image further comprises a unique identification code, such as a QR or bar code.
[0037] Interested Party: as used herein refers to an individual, company, or group that may be in interested in a particular product, service or person that they have seen or have accessed data associated with that product, service or person.
[0038] Prospective Party: as used herein refers to individuals, companies, or groups that may potentially be interested in a particular product, service or person if and when the prospective party is made aware of the particular product, service or person.
[0039] Referring now to FIG. 1A , an exemplary embodiment of a logo 100 affixed to a building 110 , wherein the logo may be indicative of property availability, is illustrated. In some examples, the logo 100 may indicate that the entire building 110 is for sale or lease. In other examples, the logo 100 may indicate that a portion of the building 110 may be available for sale, rent, or lease. For example, a building 110 may comprise multiple office spaces, apartment, or parking spaces, which may be sold, rented, or leased separately. There may be other aspects of the building that may be associated with an attached logo of the type indicated at 100 .
[0040] Referring now to FIG. 1B , an exemplary embodiment of a logo 100 affixed to a shop 120 , wherein the logo 100 may be indicative of product availability within the shop 120 , is illustrated. In some examples, the logo 100 may be placed in a location visible from the exterior of the shop 120 , which may allow potential interested parties to view product availability outside of normal operating hours of the shop 120 . In subsequent steps, the potential Interested Party may signal there interest in the products or services of the shop 120 .
[0041] Referring now to FIG. 1C , an exemplary embodiment of a logo 100 affixed to a bumper 135 of a vehicle 130 , wherein the logo 100 may indicate that the vehicle 130 may be for sale, is illustrated. In some examples, the logo 100 may be affixed to a window, which may allow for easier visibility and image capture access for potential interested parties. In some other examples, the logo 100 may represent a service that is offered by the operator of the vehicle 130 . There may be numerous products, services or people that may be associated with the placement of the logo 100 on a vehicle 130 .
[0042] In some examples, a car dealership may utilize removable logos on their available inventory, wherein the logos may be removed once the vehicle has been sold or leased. Data for the car may be linked to its adhered logo. In such examples, an Interested Party may scan the logo, evaluate the vehicle features, and determine what offer, if any, may be reasonable.
[0043] Examples may also include a designated location and date and time for vehicles, or other items identified by a logo to be displayed. For example, the present disclosure enables a hybrid physical/virtual swap meet to take place at a designated venue. Vehicles may be brought to a venue on a designated day and potential customers may peruse the vehicles identified via a logo. If the potential customer desires additional information, such as the year, model, specifications, miles and other associated information, the user may scan the logo and use the scan information to access related information on a website associated with the logo listing.
[0044] Referring now to FIG. 1D , examples of wearable tags, wherein the tag may be indicative of availability, are illustrated. In some examples, the tags may comprise a logo or an RFID, which may be detectable by portable mobile devices, such as, smartphones or tablets. In some examples, such tags may be paired with a social network profile or a profile specific to an event, such as a conference or symposium. For example, a wearer may pair earrings 140 or a watch 150 to a dating website, wherein the wearer may only detect and be detectable to other members of the dating site. The wearer may limit the area of detection, for example, to a distance or one meter or less from the wearer or alternatively to a larger area. The wearer may limit the functionality of the tag to a geographical region such as in these non-limiting examples, an area of town, a particular venue, or an event.
[0045] Other examples include wearing a nametag to a conference or symposium or other event. The name tag may or may not be associated with the conference sponsor. The nametag will include a link to a website including additional information about the person wearing the name tag, or other information the person wearing the name tag may wish to communicate.
[0046] By way of non-limiting example, a person at a symposium, conference or other organized event may wear a tag and another event attendee may scan the tag. The information associated with the tag may relate directly to the person wearing the tag, or to and organization or topic the person wearing the tag wishes to convey information on.
[0047] Referring now to FIGS. 2A and 2B , examples of a logo are illustrated. In some examples, as shown in FIG. 2A , the logo 200 may comprise an image 205 and a separate identification code 210 , such as a bar code identification or QR code. In some examples, the logo at 200 may be associated with a particular company that offers application software, services and/or hardware associated with the types of examples that are described herein. Alternatively, such as shown in FIG. 2B , a company or user may utilize their own mark as a base image for the identification device. The user's mark may be altered in subtle ways that may embed an identification code into their mark 220 , wherein the coding may not distract from the company mark 220 . In some examples, a company may embed image differences that provide encoding into their logo, wherein the logo may comprise at least one coded portion 222 , in contrast to a non-coded portion 221 .
[0048] The image differences may be extracted through an algorithm which accesses a standard image version of the user's logo and compares the differences of the captured image with the standard logo image. The algorithm may be performed with a computing device, which may be integrated into the mobile reader device, such as a smartphone, tablet, or laptop. The presence of a small version of a provider's logo image 205 may support application software in determining whether a given logo image should contain an encoded portion that may contain a unique identifier. In some examples, the image may comprise redundant sets of coded portions 222 , which may increase reader reliability.
[0049] In some examples, the image 205 may indicate that the associated person or product participates in the communication program, and the image 205 may be integrated into the company mark 220 to notify prospective parties that the mark 220 may be scanned. In some examples, the image 205 may be situated similarly to a “TM” that indicates a trademark, wherein the image 205 may be apparent but identifiable as separate from the company mark 220 .
[0050] Referring now to FIG. 3 , an exemplary system for accessing product information of an available product is illustrated. In some examples, a logo 300 may be affixed to the bumper of a vehicle 310 , and an Interested Party may scan or capture the logo 300 utilizing a mobile device 350 , such as a smartphone. In a non-limiting example, the smartphone may be used as a camera to collect a camera image of the identification device. In some examples, the mobile device 350 may be used in part of a process to retrieve information associated with the product profile and present it to the Interested Party. For example, the mobile device 350 may present a photograph 355 and specifications 360 of the vehicle 310 . The mobile device 350 may allow the Interested Party to initiate an offer or to find more information, for example, by selecting a functional icon 365 , which may trigger a secure communication to the seller.
[0051] The secure communication may or may not require nor include personal information from either party as implemented in a given implementation, wherein communication may occur through a secondary network. For example, the method of communication between the parties may be texting, but the texting may not occur directly between the phone numbers. In some embodiments, the provider of the identification related services described herein may provide temporary, anonymous user-ids, and the like to allow for communication through various channels including in a non-limiting sense, email, chat, text, social media or other such means.
[0052] In some examples, an Interested Party may scan a logo with a scanning device, such as a mobile phone or a tablet. The scanning device may transmit the captured logo to a server over a network, wherein the server may access a database and transmit the product information associated with the captured logo. The Interested Party may review the product information and determine if they may want to show interest. In some examples, the Interested Party may show interest by making an offer on the product, wherein the offer may comprise proposed terms, such as price or lease period.
[0053] Referring now to FIG. 4 , an exemplary system for accessing information for available persons is illustrated. In some examples, an available person may wear a watch 410 with a logo 400 that may further comprise a tag, which may be wirelessly detectable by a mobile device 450 , such as a smartphone, tablet, or laptop. In some examples, the tag may comprise an energized or energizable component, wherein the tag may be capable of wirelessly transmitting 405 identification information to the mobile device 450 .
[0054] In some examples, the tag may comprise an energy source, such as a battery. In such examples, the energy source may be rechargeable, such as through solar power or energy harvesting. In other examples, the tag may be capable of accepting power, wirelessly or through a wired connection. For example, where a logo may be affixed to a building, the tag may be plugged into an outlet, similarly to a neon sign in a storefront window. Alternatively, a tag may comprise an antenna that may accept power from predefined reader devices. A mobile device 450 may be equipped with the transmitting technology, such as Bluetooth, or additional hardware may be necessary. For example, a dongle may be attached, which may transmit energy and/or receive the wireless transmission 405 of data.
[0055] In some examples, the mobile device 450 may receive the wireless transmission 405 , and notify the prospective party that a tag has been detected. For example, the notification may comprise an audible, tactile, and/or visual alert. In some examples, the notification may prompt the prospective party to acknowledge the alert, or the notification may further include a snapshot of the data associated with the logo 400 . For example, the mobile device 450 may present a photo 455 and profile information 460 of the available person. The prospective party may review the details and determine if they may want to show interest. The Interested Party may click on an icon 465 , which may, in some examples, initiate direct communication with the available person associated with the logo 400 . For example, the direct communication may be a text, which may enable the available person to directly respond, without exchanging personal contact information.
[0056] Referring now to FIG. 5 , an exemplary system for accessing product information of multiple available products is illustrated.
[0057] A mobile device 550 may be able to detect a variety of product types or persons, or in other examples, the mobile device 550 may only detect a specific product type or person.
[0058] In some examples, the mobile device 550 may present detected products and persons to the prospective party simultaneously, such as through a map view 555 . For example, the map view 555 may present a road map of the vicinity and indicate the prospective party position 551 on the map. Each detected available product, service or person may be indicated by category icons within the map. Such a presentation may allow for dynamic interfacing, which may be practical when one or more of the prospective party or available products or persons may be mobile.
[0059] As an illustrative example, a mobile device 550 may detect a woman wearing earrings 510 with a logo 500 , a man wearing a watch 520 with a logo 500 , a vehicle 530 with a logo 500 on its bumper, and a building 540 with a logo 500 . The map view 555 may show two people icons 521 , 511 for the man's watch 520 and the woman's earrings 510 , respectively; a car icon 531 for the vehicle 530 ; and a building icon 541 for the building 540 .
[0060] In some examples, a prospective party may set desired products and/or product attributes, which may allow their mobile computing device to passively detect and filter available products with tags. As an illustrative example, a prospective party may be searching for an SUV and an apartment, and his mobile device may detect six nearby tags: a building for sale; an apartment building with available apartments; a motorcycle for sale; a limousine for rent; an SUV for sale; and a person from a dating website. The device may filter the results and notify the prospective party only of the SUV and the apartment building listings.
[0061] The prospective party may investigate any of the available products or persons by physically going to their location or may select the appropriate icon to access their information. Where the prospective party becomes an Interested Party, the communication may be similar to that described in FIG. 3 .
[0062] Referring now to FIG. 6 , an exemplary processing and interface system 600 is illustrated. In some aspects, access devices 615 , 610 , 605 , such as a mobile device 615 or laptop computer 610 may be able to communicate with an external server 625 though a communications network 620 . The external server 625 may be in logical communication with a database 626 , which may comprise data related to identification information and associated profile information.
[0063] In some examples, the server 625 may be in logical communication with an additional server 630 , which may comprise supplemental processing capabilities.
[0064] In some aspects, the server 625 and access devices 605 , 610 , 615 may be able to communicate with a cohost server 640 through a communications network 620 . The cohost server 640 may be in logical communication with an internal network 645 comprising network access devices 641 , 642 , 643 and a local area network 644 . For example, the cohost server 640 may comprise a payment service, such as PayPal or a social network, such as Facebook or a dating website.
[0065] Referring now to FIG. 7 , exemplary method steps for wirelessly receiving profile information, wherein the identification information may be received through a wireless transmission from a tag on a logo, are illustrated. In some examples, at 705 , energy may be transmitted to a tag on a logo. At 710 , identification information may be wirelessly received, such as illustrated in FIGS. 4 and 5 . In some examples, at 715 , a prospective party may be notified of receipt of the wireless transmission.
[0066] At 720 , the identification information may be transmitted to an external server, such as described in FIG. 6 , for example. At 725 , profile information may be received from the external server. At 730 , the profile information may be presented to the prospective party.
[0067] Referring now to FIG. 8 , exemplary method steps for wirelessly receiving profile information, wherein the identification information may be retrieved through capture of a code or image of a logo, are illustrated. At 805 , a code on a logo may be scanned, or an image of the logo may be captured, such as shown in FIG. 3 . In some examples, where the identification information may be embedded in the code or image, at 810 , a compression algorithm may be run on the code or image. At 815 , identification information may be extracted from the code or image.
[0068] At 820 , the identification information may be transmitted to an external server, such as described in FIG. 6 . At 825 , profile information may be received from the external server. At 830 , the profile information may be presented to the prospective party.
[0069] Referring now to FIG. 9 , exemplary method steps for initiating direct communication between a profile owner and an Interested Party are illustrated. In some aspects, at 905 , a prospective party may be prompted to respond to a notification of receipt of a wireless transmission of identification information. Where the prospective party may decide to ignore 907 the identification information, the process may terminate. Where the prospective party may decide to review the profile 906 , the prospective party may be prompted to respond to the profile information at 910 .
[0070] Where the prospective party may decide they are not interested 911 in the available product, service or person, the process may terminate. Where the prospective party may want to show interest 912 , they may become an Interested Party, and, at 915 , direct communication with the owner of the profile may be initiated.
[0071] Referring now to FIG. 10 , exemplary method steps for transmitting profile information to an external device are illustrated. At 1005 , identification information may be received from an external device. At 1010 , a profile database, such as illustrated in FIG. 6 , may be accessed. At 1015 , profile information associated with the identification information may be retrieved from the profile database. At 1020 , the profile information may be transmitted to the external device.
[0072] Referring now to FIG. 11 , exemplary method steps for allowing direct communication between a profile owner and an Interested Party are illustrated. At 1105 , an interest prompt may be received from an external device. At 1110 , a profile database, such as illustrated in FIG. 6 , may be accessed. At 1115 , contact information associated with the identification information may be retrieved.
[0073] At 1120 , an interest shown prompt may be transmitted to the profile owner. The transmittal means may depend on the contact information and contact preferences provided by the profile owner. For example, in some aspects, the profile owner may prefer receiving communication from interested parties through text, whereas others may prefer communicating through a social network, such as Twitter, Facebook, or a dating website.
[0074] At 1125 , a response from the profile owner may be received, and at 1130 , the response may be transmitted to the external device. In some examples, the steps at 1105 , 1120 , 1125 , and 1130 may be repeated throughout the communication between an Interested Party and a profile owner. In some examples, where the Interested Party and the profile owner may come to an agreement of terms, at 1135 , a commerce transaction may be commenced.
[0075] A number of examples of the present disclosure have been described. While this specification contains many specific implementation details, there should not be construed as limitations on the scope of any disclosures or of what may be claimed, but rather as descriptions of features specific to particular examples of the present disclosure.
[0076] Certain features that are described in this specification in the context of separate examples can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in combination in multiple examples separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination may, in some cases, be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.
[0077] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous.
[0078] Moreover, the separation of various system components in the examples described above should not be understood as requiring such separation in all examples, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
[0079] While the disclosure has been described in conjunction with specific examples, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this description is intended to embrace all such alternatives, modifications, and variations as fall within its spirit and scope.
[0080] Although shown and described in what is believed to be the most practical and preferred examples, it may be apparent that departures from specific designs and methods described and shown will suggest themselves to those skilled in the art and may be used without departing from the spirit and scope of the disclosure. The present disclosure is not restricted to the particular constructions described and illustrated, but should be constructed to cohere with all modifications that may fall within the scope of the appended claims
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The present disclosure relates to methods and apparatus for safely and securely initiating communication between parties. More particularly, the present disclosure relates to utilizing a logo as an indication of availability and as a means for a second party to show interest without requiring an exchange of personal information.
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CLAIM OF PRIORITY
[0001] This application is a continuation of and claims the benefit of priority under 35 U.S.C. 120 to U.S. patent application Ser. No. 13/340,335, filed Dec. 29, 2011, which is hereby incorporated by reference herein in its entirety.
BACKGROUND
[0002] After over two-decades of electronic data automation and the improved ability for capturing data from a variety of communication channels and media, even the smallest of enterprises find that the enterprise is processing terabytes of data with regularity. Moreover, mining, analysis, and processing of that data have become extremely complex. The average consumer expects electronic transactions to occur flawlessly and with near instant speed. The enterprise that cannot meet expectations of the consumer is quickly out of business in today's highly competitive environment.
[0003] Consumers have a plethora of choices for nearly every product and service, and enterprises can be created and up-and-running in the industry it mere days. The competition and the expectations are breathtaking from what existed just a few short years ago.
[0004] The industry infrastructure and applications have generally answered the call providing virtualized data centers that give an enterprise an ever-present data center to run and process the enterprise's data. Applications and hardware to support an enterprise can be outsourced and available to the enterprise twenty-four hours a day, seven days a week, and three hundred sixty-five days a year.
[0005] As a result, the most important asset of the enterprise has become its data. That is, information gathered about the enterprise's customers, competitors, products, services, financials, business processes, business assets, personnel, service providers, transactions, and the like.
[0006] Updating, mining, analyzing, reporting, and accessing the enterprise information can still become problematic because of the sheer volume of this information and because often the information is dispersed over a variety of different file systems, databases, and applications.
[0007] In response, the industry has recently embraced a data platform referred to as Apache Hadoop™ (Hadoop™). Hadoop™ is an Open Source software architecture that supports data-intensive distributed applications. It enables applications to work with thousands of network nodes and petabytes (1000 terabytes) of data. Hadoop™ provides interoperability between disparate file systems, fault tolerance, and High Availability (HA) for data processing. The architecture is modular and expandable with the whole database development community supporting, enhancing, and dynamically growing the platform.
[0008] However, because of Hadoop's™ success in the industry, enterprises now have or depend on a large volume of their data, which is stored external to their core in-house database management system (DBMS). This data can be in a variety of formats and types, such as: web logs; call details with customers; sensor data, Radio Frequency Identification (RFID) data; historical data maintained for government or industry compliance reasons; and the like. Enterprises have embraced Hadoop™ for data types such as the above referenced because Hadoop™ is scalable, cost efficient, and reliable.
[0009] One challenge in integrating Hadoop™ architecture with an enterprise DBMS is efficiently assigning data blocks and managing workloads between nodes. That is, even when the same hardware platform is used to deploy some aspects of Hadoop and a DBMS the resulting performance of such a hybrid system can be poor because of how the data is distributed and how workloads are processed.
SUMMARY
[0010] In various embodiments, techniques for data assignment from an external distributed file system (DFS) to a DBMS are presented. According to an embodiment, a method for data assignment from an external DFS to a DBMS is provided.
[0011] Specifically, an initial assignment for first nodes to second nodes is received in a bipartite graph. The first nodes represent data blocks in an external distributed file system and the second nodes represent access module processors of a database management system (DBMS). A residual graph is constructed with a negative cycle having the initial assignment. The residual graph is processed through iterations, with each of which the initial assignment is adjusted to eliminate negative cycles. Finally, a final assignment is achieved by removing all negative cycles of the residual graph, for each of the data blocks to one of the access module processors as an assignment flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a diagram depicting an even assignment of data from a HDFS to a parallel DBMS, according to an example embodiment.
[0013] FIG. 2 is a diagram showing a bipartite graph for the example presented in the FIG. 1 , according to an example embodiment.
[0014] FIG. 3 is a diagram illustrating an even assignment with minimal cost as shown in the FIG. 2 , according to an example embodiment.
[0015] FIG. 4 is a diagram illustrating an assignment of a block of data using an Approximate-Greedy Algorithm, according to an example embodiment.
[0016] FIG. 5 is a diagram of a method for data assignment to an external DFS to a DMBS, according to an example embodiment.
[0017] FIG. 6 is a diagram of another method for data assignment to an external DFS to a DMBS, according to an example embodiment.
[0018] FIG. 7 is a diagram of yet? method for data assignment to an external DFS to a DMBS, according to an example embodiment.
DETAILED DESCRIPTION
[0019] Initially for purposes of illustration and comprehension some context and examples are presented to highlight and illustrate the techniques being presented herein and below.
[0020] When a parallel DBMS and Hadoop™ Distributed File System (DFS) are deployed on the same node sharing processors and memory, local data can be transferred from the Hadoop™ DFS to the parallel in a highly efficient way. The network can be a bottleneck however, if Access Module Processors (AMPs) have to read a large scale amount of data stored from remote nodes. On the other hand, each AMP can be assigned nearly the same amount of workload when the parallelism is concerned, especially when the HDFS (Hadoop™ DFS) data are distributed across a cluster. Usually in the cluster, each DBMS node is configured with the same number of AMPs and all AMPs have the same performance. For purposes of illustration, it is assumed that each node has exactly one AMP in the descriptions that follow.
[0021] Also, as used herein the terms, “node” and “AMP” may be used synonymously interchangeably with one another.
[0022] Given a set of M nodes (one AMP per node) and a set of N data blocks B={B — 1, B — 2, . . . , B_N}, each block has K copies on K different nodes. Formally, an assignment of N blocks to M AMPs, is denoted as a set, A′={A — 1, A — 2, . . . , A_M}, such that the following requirements are satisfied:
A_i is a set of blocks {B_i1, B_i2 . . . } assigned to AMP i; All blocks should be assigned,
[0000]
⋃
i
=
1
M
A_i
=
B
;
and
Each block can be assigned only once, A_i∩A_j=φ.
[0026] In an assignment, a data block, B_ij is called a local assignment to A_i if it has a copy in the node where AMP i is. Otherwise, B_ij is a remote assignment to A_i, which causes data transferring through network. Correspondingly, a cost(A′) is used to measure the number of remote assignments occurring to A′.
[0027] Furthermore, an “even assignment” is defined as an assignment, which has ∥A_i|−|A_j∥<2 for any A_i and A_j. In other words, an even assignment gives each AMP almost the same amount of workload. Conceivably, multiple even assignments can exist when assigning N blocks to M AMPs, but their remote assignments may not be the same. The goal is to achieve one of the even assignments with the minimal cost(A′).
[0028] Remote costs can be huge if a naïve approach is employed. For instance, if a module operator is used to decide the assignment of each block, then B_i is assigned as AMP k (=i mod M). So, a cost of module approach can be up to one third of the total using the approach visually illustrated in the FIG. 1 .
[0029] The problem of finding an even assignment with the minimal cost can be solved in the framework of network theory. Specifically, a bipartite network G=(s, t, V — 1, V — 2, E) can be used to describe the assignment problem.
i. Two sets of vertices V — 1 and V — 2 represent the data blocks and AMPs respectively, thus v_i in V — 1 (or V — 2) denotes block B_i (or AMP i). ii. An edge directs from v_i in V — 1 to v_j in V — 2.
1. The associated cost is 0 if block B_i has a copy on the node where AMP j is; otherwise, the cost is 1. 2. The associated capacity ranges from 0 to 1.
iii. There is no an edge between any pair of vertices in V — 1 (or in V — 2). iv. Vertices s and t are newly introduced as the source and target of the network correspondingly, such that source s has an edge reaching all vertices in V — 1, and all vertices in V — 2 connect with target t.
1. The cost associated with these edges is 0. 2. The edge starting from s has the capacity exactly as 1, for all blocks should be assigned. 3. The edge ending at t has the capacity from
[0000]
⌊
N
M
⌋
to
⌈
N
M
⌉
,
because of the even-assignment requirement, where N=|V — 1| and M=|V — 2|.
[0039] The example shown in the FIG. 1 is modeled as a bipartite network in the FIG. 2 .
[0040] The assignment problem can be converted into the problem of finding the min-cost flow in the bipartite network G=(s, t, V — 1, V — 2, E). Traditionally, cycle-canceling algorithm is one of the most popular algorithms for solving the min-cost flow problem. The cycle-canceling algorithm improves a feasible solution (i.e., an assignment) by sending augmenting flows along directed cycles with negative cost (called negative cycles). Specifically, it searches for the negative cycles existing in the residual graph of the feasible solution, and adjusts the flow along the negative cycles to reduce flow cost. Adjusting flows along the negative cycles does not change the total flow capacity, because there is not any external flow introduced; the block assignment is improved correspondingly.
[0041] The algorithm can be described as:
[0042] 1) Initialize the algorithm with a feasible solution f;
[0043] 2) Construct the residual graph G′ from f;
[0044] 3) While G′ contains a negative cycle:
[0045] 4) Adjust the feasible solution f by the negative cycle; and
[0046] 5) Return the flow as an optimal solution.
[0047] The dash lines in the FIG. 3 display a min-cost flow for the network defined in FIG. 3 . Those connecting vertices in V — 1 with that in V — 2 give the same assignment as FIG. 2 .
[0048] According to Algorithm 1, the complexity of cycle-canceling algorithm is composed of two parts: the cost of finding a feasible solution and the part of improving the feasible solution for a min-cost network flow. The focus here is on the second part, because the cost of finding a feasible solution can be relatively much cheaper (i.e., O(N)). Finding a negative cycle in the bipartite network G=(s, t, V — 1, V — 2, E), has a complexity of O(M 2 N), whereas there exist at most N negative cycles. Therefore the complexity of the algorithm can be described as O(M 2 N 2 ).
[0000] Approximate the Solution with Less Time Cost
[0049] The idea of converting the assignment problem into a min-cost flow problem and using cycle-canceling to obtain the optimal solution, is cost effective to implement. However, the complexity of the algorithm is not always satisfying. For instance, it can take over 10 seconds to assign 3565 blocks to 100 AMPs when a MacBook® Pro with 2.4 GHz Intel® Core 2 Duo CPU and 4 GB DDR3 memory is used for the execution.
[0050] In some cases, a number of remote block transferring can be allowed to complete the assignment with less time cost, as long as the even assignment is guaranteed. Therefore, approximation approaches are achievable. One such approach is now presented as an “Approximate-Greedy Algorithm” (AGA) to solve the even-assignment problem. The AGA obtains an even assignment much faster than the cycle-canceling algorithm usually, but its cost may not be minimal.
[0051] The basic idea of the algorithm is to assign a block to AMPs having its copies, otherwise to an AMP with minimum assignments so far. It can be described as Algorithm 2 below:
[0000]
1.
For each block B i ;
2.
FOR each AMP A j containing a replica of B i ;
3.
IF A j is not saturated and A j has the minimum load:
4.
Assign B i to A j , and continue to Step 1;
5.
FOR each AMP A j containing a replica B i :
6.
FOR each block B i assign to A j :
7.
FOR each AMP A g containing a replica of B i ;
8.
IF Ag is not saturated and A g has the minimum load:
9.
Re-assign B i from A j to A g ;
10.
Assign Bi to A j , and continue to Step 1; and
11.
Assign B i remotely to an AMP with minimum load.
[0052] The loop from line 2 to line 4 tries to assign a block (e.g., B_i) to an AMP with its local copies, if possible. If all AMPs having B_i are saturated, the blocks that have been assigned to those AMPs are considered for re-assignment: if one of these blocks can be assigned to any other AMP having its copies, it is moved to that AMP and at the same time B_i takes its place. But when re-assignment is impossible, B_i is assigned to an AMP with minimum assigned blocks currently, as a remote assignment.
[0053] The instinct behind the AGA is that the probability of finding a re-assignment is very high when the number of blocks (i.e., N) is far larger than that of AMPs (i.e., M). This can be explained by the diagram presented in the FIG. 4 .
[0054] To assign block B — 0, the AMPs (A — 0, A — 1, . . . , A_k at the second level) are first considered to see if they have its local copies. If all these AMPs are saturated,
[0000]
NK
M
[0000] blocks (B′ — 0, B′ — 1, . . . , B′_l at the third level, where
[0000]
l
=
NK
M
)
[0000] are checked for re-assignment. Then, the AMPs (A′ — 0, A′ — 1, . . . , A′_g at the fourth level) having their local copies must be considered. Assume that all blocks including their copies are randomly distributed across AMPs initially; the probability that the value of ‘g’ being equal to M can be close to 1 in most cases.
[0055] The complexity of the AGA is also composed of two parts: the first
[0000]
NK
M
[0000] blocks can always be assigned locally in
[0000]
O
(
NK
2
M
)
,
[0000] and in the worst case all other blocks are considered for re-assignment in
[0000]
O
(
(
N
-
NK
M
)
(
K
+
NK
2
M
+
M
-
K
)
)
.
[0000] Thus, the overall complexity of the AGA is:
[0000]
O
(
(
N
-
NK
M
)
(
K
+
NK
2
M
+
M
)
)
.
[0056] Modeling the assignment problem as the min-cost network flow problem makes it possible to apply existing efficient algorithms. Adapting the existing cycle-canceling approach, a negative cycle-canceling algorithm is proposed, which is cost-effective to implement and can achieve the optimal solution in polynomial time. Furthermore, the approximation is used as an alternative, when a number of remote data transferring is allowed to obtain a rather good solution within much lower time cost. Moreover, the AGA is simple to implement and is effective enough when the number of blocks is far more than that of AMPs.
[0057] With the above detail of the techniques presented, various embodiments are now presented with the discussion of the FIGS. 5-7 .
[0058] FIG. 5 is a diagram of a method for data assignment to an external DFS to a DMBS, according to an example embodiment. The method 500 (hereinafter “data assignment manager”) is implemented as instructions within a non-transitory computer-readable storage medium that execute on one or more processors, and the processors are specifically configured to execute the data assignment manager. Moreover, the data assignment manager is programmed within a non-transitory computer-readable storage medium. The data assignment manager is also operational over a network; the network is wired, wireless, or a combination of wired and wireless.
[0059] The data assignment manager presents another and in some ways an enhanced processing perspective to what was discussed and shown above with respect to the FIGS. 1-4 .
[0060] At 510 , the data assignment manager receives an initial assignment of first nodes to second nodes in a bipartite graph, such as the bipartite graph shown above with respect to the FIG. 2 . The first nodes representing data blocks in an external distributed file system, such as a HDFS, and the second nodes representing AMPs of a parallel DBMS.
[0061] According to an embodiment, at 511 , the data assignment manager organizes the first nodes and the second nodes in the bipartite graph.
[0062] Continuing with the embodiment of 511 and at 512 , the data assignment manager weights each edge of the bipartite graph.
[0063] At 520 , the data assignment manager constructs a residual graph with a negative cycle having an initial assignment. That is, the process associated with constructing the graph is given an initial assignment with a negative cycle.
[0064] At 530 , the data assignment manager iterates the residual graph such that with each iteration the initial assignment is adjusted to eliminate negative cycles of the residual graph. Finally, there is no negative cycles present in the residual graph. This situation was discussed above with reference to the FIG. 3 .
[0065] In an embodiment, at 531 , the data assignment manager ensures that each data block is assigned to a single specific access module processor in each iteration of the residual graph.
[0066] At 540 , the data assignment manager returns a final assignment for each of the data blocks to one of the AMPs as an assignment flow. In other words, the graph includes assignments for each data block to a specific AMP.
[0067] In an embodiment, at 550 , the data assignment manager populates the data blocks to the AMPs in accordance with the final assignment.
[0068] In a scenario, at 560 , the data assignment manager integrates the distributed file system with the DBMS via the data blocks on the assigned AMPs.
[0069] FIG. 6 is a diagram of another method 600 for data assignment to an external DFS to a DMBS, according to an example embodiment. The method 600 (hereinafter “workload assignment manager”) is implemented as instructions within a non-transitory computer-readable storage medium that execute on one or more processors, and the processors are specifically configured to execute the workload assignment. Moreover, the workload assignment manager is programmed within a non-transitory computer-readable storage medium. The workload assignment manager is also operational over a network; the network is wired, wireless, or a combination of wired and wireless.
[0070] The workload assignment manager presents yet another view of the processing discussed above with respect to the FIGS. 1-5 .
[0071] At 610 , the workload assignment manager obtains data blocks for an external distributed file system.
[0072] According to an embodiment, at 611 , the workload assignment manager generates a source node and a target node for organizing the graph.
[0073] Continuing with the embodiment of 611 and at 612 , the workload assignment manager ensures that the source node includes first edge connections to each of the first nodes of the first set of nodes.
[0074] Still continuing with the embodiment of 612 and at 613 , the workload assignment manager ensures that the target node includes second edge connections to each of the second nodes in the second set of nodes.
[0075] Continuing with the embodiment of 613 and at 614 , the workload assignment manager assigns costs to each edge connection for each first node from the first set of nodes to each second node from the second set of nodes.
[0076] Still continuing with the embodiment of 614 and at 615 , the workload assignment manager increases the cost for a particular edge between a particular first node and a particular second node when the particular second node already includes an existing edge connection to the particular first node. This was discussed in detail above with reference to the FIGS. 1-3 .
[0077] At 620 , the workload assignment manager acquires AMPs for a DBMS.
[0078] At 630 , the workload assignment manager organizes a first set of nodes to represent the data blocks and a second set of nodes as the AMPs within a bipartite graph.
[0079] At 640 , the workload assignment manager uses the first set of nodes and the second set of nodes to produce a minimum cost graph with each of the first set of nodes assigned to a specific one of the second nodes in the second set of nodes.
[0080] According to an embodiment at 641 , the workload assignment manager processes a cycle-canceling algorithm to produce the minimum cost graph.
[0081] Continuing with the embodiment of 641 and at 642 , the workload assignment manager initiates the cycle-canceling algorithm with an initial negative cycle and initial assignment of the first nodes to the second nodes.
[0082] At 650 , the workload assignment manager provides the minimum cost graph as a final assignment for the first set of nodes mapped to the second set of nodes.
[0083] FIG. 7 is a diagram of yet method 700 for data assignment to an external DFS to a DMBS, according to an example embodiment. The method 700 (hereinafter “block assignment manager”) is implemented as instructions within a non-transitory computer-readable storage medium that execute on one or more processors, the processors specifically configured to execute the block assignment manager. Moreover, the block assignment manager is programmed within a non-transitory computer-readable storage medium. The block assignment manager is also operational over a network; the network is wired, wireless, or a combination of wired and wireless.
[0084] The block assignment manager presents another perspective and some aspects enhancements to the processing show above with respect to the FIGS. 1-6 .
[0085] At 710 , the block assignment manager generates a graph having a source node, first nodes, second nodes, and a target node.
[0086] At 720 , the block assignment manager represents each first node as a block of data from an external file system, such as HDFS, and each second node as an AMP on a parallel DBMS.
[0087] At 730 , the block assignment manager processes an approximate-greedy algorithm on the source node, the first nodes, the second nodes, and the target node to produce a modified graph having assignments between the first nodes and the second nodes. This was described above with reference to the FIG. 4 .
[0088] According to an embodiment, at 731 , the block assignment manager selects the approximate-greedy algorithm when the total number of the data blocks is greater than the total number of AMPs by a predetermined threshold value.
[0089] In a scenario, at 732 , the block assignment manager permits specific data blocks to be assigned to specific AMPs that already have copies of those specific data blocks.
[0090] In another case, at 733 , the block assignment manager configures a minimum load for each AMP before initiating the approximate-greedy algorithm.
[0091] At 740 , the block assignment manager returns a pointer to the modified graph.
[0092] According to an embodiment, at 750 , the block assignment manager populates the AMPs with specific databases for the external file system, which are identified by edge connections in the modified graph.
[0093] The above description is illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of embodiments should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
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Techniques for data assignment from an external distributed file system (DFS) to a database management system (DBMS) are provided. Data blocks from the DFS are represented as first nodes and access module processors of the DBMS are represented as second nodes. A graph is produced with the first and second nodes. Assignments are made for the first nodes to the second nodes based on evaluation of the graph to integrate the DFS with the DBMS.
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BACKGROUND OF THE INVENTION
a. Field of the Invention
This invention relates to the protecting coatings or linings manufacturing industry, and more particularly relates to the industry specialized in the manufacture of water-proof protective coatings and weather-proof linings, useful for protecting several construction elements such as wood, bricks, cement, mortar, plaster, tiles, etc., but said elements also can be used with objects such as clay, paper, paperboard, etc., as ornamental and also protecting coverings.
B. Description of the Prior Art
It has been a main goal of the manufacturers of protecting products for those surfaces exposed to weather, the attainment of a type of coating which, further to provide a positive aesthetic appearance, is of great resistance and proved long-term life.
Some enamels or paints based on varnish have been known which are manufactured by mixing fine pigments and using said varnish as a carrier.
There is also a type of enamel capable of becoming dry quickly, and prepared with a varnish based on a synthetic resin. Said present enamels dry in a short time of from 2 to 4 hours, compared with the experience of some years ago, when said paints were made with oil or natural resin varnishes. There is also an enamel flat upon drying, and manufactured in the same way as those glossy enamels, with the only difference that a less fine pigment is employed, with a smaller proportion of varnish and a greater amount of volatil solvent as with said common enamel. However, this type of paints or flat coatings, due to their pleasant decorative effects, are employed indoors but they are wholly unsuitable for outdoors applications.
There are also a range of protecting coatings which are manufactured having in mind a concrete application thereof. Thus, several materials are known, particularly anticorrosive compounds and specially antiscale compounds, including the so-called marine-type varnishes, the practical application of which is positively outdoors.
However, it is broadly known by those skilled in the art that those usual varnishes, in a solvent-based solution, lack of yieldability, generally forming rigid films of a crystaline type, hard, brittle and without pores preventing thus the necessary gaseous interchange between atmosphere and the coated materials.
These characteristics result in the application of said type of varnishes to be negative due to the fact that, in a limited period of time fail upon exposition to humidity and sun radiation, and specially when applied on non-dimensionally stable substracts, such as wood.
In fact, wood is one of those materials which have presently greater application in the finishing of outdoors surfaces, due to its great aesthetic possibilities, but having, however, a main drawback consisting in the easy deterioration thereof due to eroding agents.
The glossy finishing of wood used in outdoor applications, is not the most suitable due to its few aesthetics and due to this, the skilled in the art have been seeking for a type of coating having a flat appearance for outdoor application.
As above stated, said flat varnish is not suitable for outdoors application, since for this effect substances producing flat effects should be incorporated therein, such as silicic acid or opaque charges, such as talcum, some carbonates, barium sulfate, diatomaceous earths, etc., thus adversedly affecting the life of said films since their humidity absorption is considerably increased, thus impairing the application thereof for outdoors finishings.
In the field of modern organic chemistry there is an active search for hydrophobic plastic aqueous dispersions which, in spite of its capacity of being diluted with water, when the film formed by said compounds is dry, becomes water-insoluble and posesses an extraordinary repelency thereto.
It also has been experimented with the so-called "large" varnishes or high-oil varnishes which due to their great content of this latter product, are more elastic than "short" or low-oil varnishes and, therefore, are more resistant to natural eroding agents.
However, there is no notice that a product based on a water-dilutable plastic varnish has been manufactured up to the date of this application, which becomes hydrophobic when dry and also a semi-glossy or flatproduct, with long-lasting characteristics to weather and having the possibility of being colored and grained upon passing a brush thereon from one end to the other, thus obtaining a wood-like effect.
This attainment is in contrast with the troublesome treatment of the prior art employed to improve the appearance of wood, color the same and produce a sort of graining of high-quality wood, such as, for instance, oak graining which required of a delicate labor by the painter with high specialization and, furthermore, of some danger.
The process used in the prior art consisted in scratching the wood with a special tool, followed by a dying with water anilines, which was protected with a couple of passes of gasoline-fused virgin wax.
The drawbacks of said complicated and time-consuming process are apparent: short life of the dying, since said anilines are not resistant to sun-light; sticky hand of said wax in warm temperatures; loosening thereof due to the action of water; damage of the gloss in short time and great inflamation danger by said wax-gasoline mixture. A finishing hand of varnish based on a solvent did not improve substantially the results.
SUMMARY OF THE INVENTION
Thus, it is the main object of this invention to formulate a film with an extraordinary long-life in weather variable conditions, and useful as a decorative element modifying the appearance and natural texture of wood or any other material, stressing the vein or grain thereof, and providing a broad coloring which is resistant even to UV rays and, therefore, to decoloration.
It is another object of this invention to manufacture a protecting coating which, when dried, forms at the surface thereof a layer resistant to eroding agents and which, due to its markedly hydrophobic characteristics, is rain-and water-repelent in any of the forms thereof, thus preventing the excessive moistening of wood.
Another further object of this invention is to provide a water-dilutable plastic varnish capable of forming a dry base, an elastic semi-glossy transparent layer or film which is highly water-repelent, so as said plastic binding base is not cracked or detached. These facts, together with the low humidity absorption capacity prevents the deterioration of the constitutive elements thereof, or the pass of said humidity to said substract, which often resulted in formation of alkaline salts known as saltpeter which produce the final dettachement of the usually applied films.
Still another object of this invention is to provide a protecting film for outdoor surfaces, employing a binding based on plastic dispersions, providing for a gaseous interchange between the substract of the application zone and the outer atmosphere, thus allowing for the moist of the materials to be dryed through the pores of said protecting film, without affecting adversedly the adherence thereof.
It is also another object of this invention to provide a water-dilutable plastic varnish, which is hydrophobic when dry, naturally flat, useful to stress the positive aesthetics in indoors and also of long life and high resistant to weather, without the need of incorporating flat-effect producing materials or fillers.
It is still a further object of the invention to provide a water-dilutable plastic varnish, hydrophobic when dry, capable of forming a fast-drying painting through the addition of pigments and low-water absorption charges, with aqueous dilution and silky hand, completely washable and with water repellency and aqueous stain repelent; being characterized also in that by increasing the amount of the charge to said plastic varnish, a paste-like mixture useful for patching and pointing of cracks, holes, nail heads, as well as for relief decorative works in outdoors or movable articles for indoors. Said paste, added with color pigments complements the function of the aqueous-dispersion varnishes also colored since the coating obtained thereby on the patching and pointing by means of the paste-like mixture produces a varnished patching which, for the eveness thereof does not seem such patching and pointing.
There is also a further object of the invention in the application thereof as seals for paper and the derivatives thereof, due to its highly bactericide character, thus permitting the employment thereof in containers of said materials, intended to contain foodstuffs or in surfaces wherein the fungi and bacteriz growth are to be prevented.
These and other further objects of this invention can be infered from the analysis of the following specification and examples, by those skilled in the art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The binding portion is constituted by plastic dispersions in an aqueous medium, such as polyvinyl acetate or acrylics and combinations thereof, or copolymers of said products with other products providing different degrees of elasticity without the use of plastifiers capable of migrate. The inclusion of non-plastified hard products with inner-plastified soft products, modifies the hardness of conventional inner films, thus preventing the cracking thereof when applied in outdoors. Thus, the resilience or elasticity obtained from said plastic dispersions of this invention allows the application thereof to wood, accompanying the same in its expansion and contraction motions without affecting its original structure.
This composition includes a self-protecting composition formed by a synergistic combination of several types of waxes and paraffines formed in an emulsion to provide said product with a satin hand and protecting the same against ageing, providing a flat appearance and a notorious repellency to water and stains.
The waxes useful in this invention are selected from synthetic wax (DG or LGE wax, B.A.S.F.), micro-crystalline wax (Mobilwax, Mobil Oil Co.). DG waxes are ester waxes based on bleached and modified montan waxes. LGE waxes are ester waxes based on bleached and modified montan waxes combined with an emulsifying non-ionagen system. The paraffin employed is a reffined white paste with small content of oil and having a melting point of from 50° to 62°C., there being used as emulsifier an oleic acid saponified by an amine (preferably morpholine due to the volatile character thereof which forms a non re-emulsionable film upon drying thereof).
______________________________________FORMULATION FOR THE SELF-PROTECTING EMULSION______________________________________ Parts by weightDG or LGE wax 20-Mobilwax 12Paraffin (paste) 6Oleic acid 8Morpholine 3Water 51Total 100______________________________________
The self-protecting emulsion of the above formulation can be manufactured by using several processes; there being pointed out, only for illustrative purposes, the following exemplified process:
EXAMPLE 1
a. The synthetic wax, the micro-cristalline wax, the paraffin and the fatty acid are melted to a temperature of 95°C. in a heated double-walled container.
b. The amine is slowly added, with constant stirring.
c. Water is heated to its boiling point, and is incorporated to the other melted products, slowly, in order to form a uniform emulsion.
d. Stirring is continued more slowly until the temperature does down to the room temperature.
The protecting emulsion, the formulation and process of manufacture of which are given above, is added to another base formulation called end base product, the formulation of which is as follows:
(The pointed out ratios can vary to achieve different types of hardness desired).
______________________________________"Mowilith" (Polyvinyl acetate, Hoescht* 55 to 90 Kgs.Acrylic dispersions (Rohm and Haas, BASF) --Diacetonic alcohol (water-soluble solvent) 4.150 Kg."Preventol CMK" Bayer (chloro-m-cresol 0.200 Kg.as a disinfectantEthylenglycol (water retainer) 5.300 Lts.Ammonia 25°Be (alkalinizer) 1.500 Lts.Nopco NDW, Nopco Industrial (fatty acidesters for Antifoaming) 0.800 Lts."Thilose 12.000 K", Hoescht (methylcellulose 12.000 centipoises in a 2% waterdispersion as a thickener)(in aqueous solution, 3%)Precipitated calcium carbonate (neutralizer) 0.550 Kg.Water 0.700 Lts.______________________________________ *Acrylic dispersions as used in Example 1 and throughout the specificatio refers to anion active water dispersions of an acrylic acid ester copolymer.
Said self-protecting emulsion is admixed with said base formulation, in a ratio of from 10 to 45 kgs. as the final step to obtain the end product.
In order to specify the process of manufacture of said base product, as well as the formulation of the end product, obtained through the addition of said self-protecting emulsion, the following example is given.
EXAMPLE 2
In admixing tanks the required amount of plastic dispersions are introduced; while in another container the alcohol diacetone and Preventol GMK priorly dissolved therein as well as ethyleneglycol and ammonia are stirred and in a fine and continuous stream are added to said plastic dispersion, in a stirred state by means of a Cowles-Dissolver or other similar apparatus, at a speed of about 1800 rpm. When the above described addition is ended, said antifoaming is added, as well as the thickener solution and said precipitated calcium carbonate, mixed in said water.
Stirring is continued during 10 more minutes and said self-protecting emulsion is added.
When the above formulation is completed, stirring is continued but just to 1200 rpm. for 20 minutes until an homogeneous product is obtained with mean viscosity and silky hand.
When a varnish with additional pigments is desired, in this point the previously prepared dispersions of said pigment are added, containing minimum amounts of moisteners and dispersants in order to prevent the labor of said selfprotecting emulsion to become overcomed; as the end step of this example, said finished product is strained and packed.
It is to be pointed out that the structural characteristics of the product of the formulation hereinabove described, are such that when a brush with said product in colored form is passed on a surface previously painted with a product of this invention wherein pigments and charges as disclosed have been added, an attractive decorative application is obtained, consisting in the colored graining due to the different concentration of the brush hair when passes from one end to the other.
Said graining resambles intimately to that of the wood, and are an economical substitute therefor when applied directly to gypsum walls, refined cement walls, or on paper or cardboard, as well as on vinylic or acrylic paints.
Of course, upon variation in the motion imparted to the brush, different visual effects can be obtained on the treated surface, such as waves, zig-zag, tassels, etc. A second passing of the brush in a cross direction onto the already dried graining, produces an open-waving effect.
These decorative capabilities are obtained due to the transparency and color characteristics of the product, as well as to its body, impairing for the graining to extend and disappear when dry, there being obtained, through this process, to positively change the aesthetics of wood and other constructive elements, in a non-expensive way.
Compounds prepared according to processes and formulations as given above, have been subjected to some laboratory tests among which they can be cited those effected for the measurement of impermeability and bactericidal and fungicidal activities, as cited hereinbelow together with the respective results, in order to demonstrate said characteristics.
REPORT FROM CHILEAN UNIVERSITY OF PHARMACOLOGICAL RESEARCH AND ASSAYS
Report No. 1
Papers, paperboards and cardboards were subjected to impermeability test as recommended by Berl Lunge D'Ans.
______________________________________(Filtration):Impregnated letter-type paper 15 daysNon-impregnated letter-type paper 48 hoursGray paper impregnated More than 28 daysNon-impregnated Gray papel 3 minutesImpregnated paperboard More than 28 daysNon-impregnated paperboard 10 days______________________________________
Conclusion: "papers and paperboard resist well. Cardboards also resist well, but they cannot be bent as their resistance diminishes upon cracking".
All these products prevent the pass therethrough into the substract of foodstoofs and ice, making easy the off-molding and maintaining the package appearance.
Undesirable substances cannot pass upon dissolution of cardboard into the foodstoof, whereby said product film constitutes an efficient barrier from the sanitary point of view and having the further advantage on common paraffincoated products, of its resilience and bending-resistance.
Likewise, fungi and bacteria cannot growth on the treated surfaces, as appears from the following report.
Report No. 2 Tests "Halo" System In Plate.
a. Test against Staphylococcus aureus
An assay was made with each of papers and paperboards impregnated. There is a partial inhibition of bacterian growth in contact zone. There is no diffusion nor bacterial action of the antiseptic substance on said seed.
b. Test against Salmonella Typhi
This test was made on each of the papers and cardboards impregnated.
There is a partial inhibition on bacterial gowth at the contact zone, except on thin white paper (letter paper) which offers a whole inhibition of the bacterial growth at the contact zone. There is no diffusion of said antiseptic.
An equivalent test effected on papers non-impregnated, gives plenty of seed growth, inclusive at the contact zone. There is also saprophytes growth at the edge of the paper.
The elemental proportion of the compounds entering into the above disclosed formulations, have been included merely as illustrative examples; therefore, said proportions can be varied without affecting the inventive concept of the above disclosed composition and process.
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An outdoor coating based on a water-thinnable plastic varnish, which is hydrophobic when dried, and comprising, in combination a self-protecting emulsion basically comprised by waxes and paraffins, and a compound mainly constituted by acrylic dispersions and vinyl chloride polymer acetates, and also includes a process for producing the same.
| 2
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a serial interface embedded in a one-chip LSI circuit together with a processor and, more particularly, to an improvement in a data input/output control device for a transfer of data between the processor and an external apparatus.
2. Description of the Related Art
Conventionally, the serial interface embedded in a one-chip LSI circuit together with the processor is operated at processor clock for the processor when the transfer of data is conducted between the processor and an external apparatus, such as by synchronizing a signal input to the serial interface (a data transfer clock and signals necessary for the transfer of the data from the external apparatus) with the processor clock.
The conventional serial interface is described hereunder with reference to FIGS. 1, 2, and 3.
Construction of a conventional serial interface, the processor and the external apparatus are shown in FIG. 1. The serial interface is equipped with structure to perform data input/output control and input/output data transfer. The input/output control is accomplished for all the units within the "data input/output device" dashed lines. The output buffer 530, shift register 540, and input buffer 550 perform input/output data transfer and are contained within the "data transfer device" dashed lines.
Data is transferred to and from an external apparatus 500. Transmission of a reception of the data is conducted between the external apparatus 500 and the embedded-type serial interface equipped with the devices labelled with numeral references above 500.
A transfer clock 501 is supplied from the external apparatus 500.
A transfer control signal 502 shows that the transfer of the data to the external apparatus is ready.
A processor 503 stores the data inputted from the external apparatus 500 or executes an operation.
A processor clock 504 is for an operation of the processor 503.
A controller 510 outputs control signals, which is synchronized with the processor clock 504.
A ready signal 511 is outputted from the controller 510 to show that the input or the output of the data is ready.
A synchronization means 521 synchronizes the transfer clock 501 with the processor clock 504, which is shown in a time chart of FIG. 2.
A synchronization means 522 synchronizes the transfer control signal 502 with the processor clock 504, which is shown in a time chart of FIG. 3.
A clock 523 is synchronized with the processor clock 504 by the synchronization means 521.
A signal 524 is outputted from the synchronization means 522.
An output buffer 530 holds the data of n bits (n is a positive integer) transferred from the processor 503 to the external apparatus 500.
A shift register 540 obtains the data of n bits outputted from the output buffer 530, which is synchronized with the clock 523 is accordance with a transmission data load signal outputted from the controller 510. The shift register 540 shifts the data in a direction of the most significant bit (MSB) by one bit at one time which is synchronized with the clock 523 in accordance with a shift clock signal.
One-bit data 541 located at the MSB of the shift register 540 are outputted to the external apparatus 500.
One-bit data 542 from the external apparatus 500 are inputted to the least significant bit (LSB) of the shift register 540.
An input buffer 550 obtains the data of n bits held in the shift register 540, which is synchronized with the processor clock 504 in accordance with the shift clock signal outputted from the controller 510.
A down counter 560 is set with an initial number m (0<m≦n; m is an integer) for a start of a count down of the bits in the data to be inputted or outputted, and reduces m by one at a timing of the clock 523.
A flag circuit 570 with a flag showing status of the output buffer 530 and the input buffer 550 is set with a set signal 571 output from the controller 510 and is reset with a reset signal 572 outputted from the processor 503, the set signal 571 and the reset signal 572 being synchronized with the processor clock 504.
The serial interface constructed as described above is operated to output the data or input the data. The operations are described hereunder with reference to FIGS. 1, 2, and 3 (reference can also be made to "MN 19011, 1909 LSI Manual" by Matsushita Electronics corporation.
Data Out
The processor 503 writes in the output buffer 530 the data to be output to the external apparatus 500, and resets the flag circuit 570 with the reset signal 572 so that the controller 510 is in formed that data is held in the output buffer 530.
When a flag is reset, the controller 510 outputs the control signal 511, a binary 1 to inform the external apparatus 500 that output of the data is desired. Detecting the binary 1 control signal 511, the external apparatus 500 outputs the control signal 802 also a binary 1. Timing of the transfer control signal 502 is synchronized with the processor clock 504 by the synchronization means 522. The resulting synchronized signal is output as the signal 524. The signal 524 is then input to the controller 510.
When the signal 524 is 1, the controller 510 outputs a transmission data load signal so that the data in the output buffer 530 is transferred to the shift register 540. Simultaneously, the controller 520 outputs a load signal so that the initial number m is sent to the down counter 560. The first bit of data stream 541 is located at the MSB of the shift register 540 is transferred to the external apparatus 500. Simultaneously, the controller 510 sets the flag circuit 570 with the set signal 571.
The controller 510 looks at the signal 524. If the signal 524 is still a binary 1, the controller 510 outputs a shift clock signal so that the data in the shift register 540 is shifted in the direction of the MSB by one bit at a falling edge of the transfer clock 523. This second bit of data, formally located next to the MSB is output over data line 541. Simultaneously the controller 510 outputs a count clock signal so that a number m-1, obtained by reducing the initial number m by one, is held by,the down counter 560.
If the signal 524 is changed to a binary 0, the controller 510 does not output the shift clock signal so that the shift register 540 is not operated.
The above operations are repeated until (m+1)th data bit are outputted (until the down counter 560 counts 0).
When the above operations are conducted, the processor 503 refers to the flag circuit 570. If the flag circuit 570 is reset to show that data is in the output buffer 530, the processor 503 does not write data into the output buffer 530. If the flag circuit 570 is set, the processor 503 writes data in the output buffer 530 and resets the flag circuit 570. Hence, the processor 503 writes data into the output buffer 530 one bit at a time.
When the down counter count reaches 0, the controller 510 refers to the flag circuit 570. If the flag circuit 570 is reset to show that data is in the output buffer 530, the controller 510 outputs the transmission data load signal so that the data in the output buffer 530 is transferred to the shift register 540, and sets the flag circuit 570 with the set signal 571. Simultaneously, the controller 510 outputs the load signal so that the initial number m is set to the down counter 560. If the flag circuit 570 is set to show that no data is in the output buffer 530, the controller 510 outputs a binary 0 as the ready signal 511 so that the external apparatus 500 is informed that transfer of the data is completed.
Data In
The processor 503 reads the data in the input buffer 550 and then resets the flag circuit 570 with the reset signal 572 to show that no data is held in the input buffer 550.
Informed that the flag circuit 570 is reset the controller 510 outputs a binary 1 ready signal 511 to show that data may be transferred in. Detecting the binary 1 ready signal 511, the external apparatus 500 outputs a binary 1 transfer control signal 502. Timing of the transfer control signal 502 is synchronized with the processor clock 504 by the synchronization means 522, the result being output as the signal 524.
Detecting the binary 1 of signal 524, the controller 510 outputs a reception data load signal to the input buffer 550 so that the data in the shift register 540 (the data which has been inputted thereto) is copied. The first bit on data input 542 is output from the external apparatus 500 at a rising edge of the transfer clock 501. Simultaneously the controller 510 outputs the load signal so that the initial number m is set to the down counter.
The controller 510 refers to the signal 524. If the signal 524 is a binary 1, the controller 510 outputs the shift clock signal to the shift register 540 so that the data in the shift register 540 is shifted in the direction of the MSB by one bit, and the first bit on data input 542 is input to the LSB position of the shift register 540 at the rate of the clock 523. Simultaneously the controller outputs the count clock signal so that the number m-1 is held by the down counter 560, If the signal 524 is a binary 0, the controller 510 does not output the count clock signal so that the shift register 540 is not operated.
The operations described above are repeated until the (m+1)th data is input (the down counter 560 counts 0).
When the above operations are conducted, the processor 503 refers to the flag circuit 570. If the flag circuit 570 is reset to show that no data is in the input buffer 550, the processor 503 does not read any data therefrom, If the flag circuit 570 is set to show that data is held in the input buffer 50, the processor 503 reads the data and resets the flag circuit 570.
When the down counter 50 counts 0, the controller 510 refers to the flag circuit 570. If the flag circuit 570 is reset to show that the data in the input buffer 550 has been read, the controller 510 outputs the reception data load signal so that the data in the shift register 540 is transferred to the input buffer 550, and sets the flag circuit 570. Simultaneously the initial number m is set to the down counter 560.
If the flag circuit 570 is set to show that the data in the input buffer 550 has not been read by the processor 503, the controller 510 outputs a binary for 0 the ready signal 511 so that the external apparatus 500 is informed that the input of the data may not begin yet.
As is described hereinbefore the embedded-type serial interface synchronizes, at the input of the data, the data transfer clock and the signals necessary for the transfer of the data with the processor clock 504 for the processor 503. Such synchronization enables the serial interface to conduct the operations base on the processor clock 504 for the processor 503.
However, since all the units of the serial interface are synchronized with the processor clock 504 for the processor 503, a loss of electric power has been observed. That is, a commonly utilized processor clock frequency is several tens of Mega Hertz (MHz) and this is much higher than a frequency required for the input and the output of data, at several tens of kilo Hertz (kHz). It is commonly known that the higher the frequency required for the device, the more the electric power consumed. Particularly when a circuit is designed by utilizing a CMOS type transistor, the amount of electric power consumed by the circuit increases with an increase in the processor clock frequency.
OBJECTS AND SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a data input/output control device for a serial interface which eliminates the loss of electric power, caused by a difference between he processor clock frequency and the frequency required for data transfer, especially when the processor clock frequency is extremely high, such as when a one-chip microcomputer is utilized.
The above object is accomplished in a data input/output control device integrating a one-chip microcomputer with a data transfer device and a processor by utilizing a single clock, the data transfer clock, to time all the functions of the input/output control device which, in turn, controls the data transfer device. The data transfer device transmits and receives from an external apparatus by a serial data stream and transmits to and receives from the processor is parallel. The processor processes data input to the data transfer device and transmits the processed data to the data transfer device to be transmitted to the external apparatus. The data input/output control device utilizes the transfer clock of the external apparatus, even though the transfer clock is slower than the clock for the processor.
The loses of electric power which is caused by the difference between he processor clock frequency and the frequency required the prior art for the data input, and the data output is eliminated. Power dissipation required for the data transfer of the conventional data input/output control device can be reduced even when the processor clock frequency for the processor is extremely high, such as when a CMOS-type device is utilized. A certain amount of electricity is consumed depending upon the transfer speed, which varies depending on the kind of the external apparatus and a presence or absence of external apparatus. By constructing the data input/output control device of the present invention to consume different mounts of electricity in accordance with the transfer clock, energy efficiency is increased.
Alternate Forms of the Present Invention
The data input/output control device may comprise a controller for controlling the data input and the data output of the data transfer device, and a flag holding unit for holding a flag which shows if the data have been inputted to the data transfer device by one of the processor and the external apparatus.
The data input/output control device may further comprise a first synchronization circuit for synchronizing an output from the flag holding unit with the transfer clock, the output being sent to the controller, and a second synchronization circuit for synchronizing the output from the flag holding unit with the clock for the processor.
The data input/output control device, wherein the data transfer device may comprise a shift register for converting a transmission data from parallel into serial and a reception data from serial into parallel, a reception buffer for holding temporarily the data which have been stored in the shift register so that they are inputted to the processor, and a transmission buffer or holding temporarily the data outputted from the processor so that they are stored in the shift register, wherein the flag holding unit holds the flag which shows if the transmission buffer holds the data at a transmission of the data as well as shows if the reception buffer holds the data at a reception of the data.
The data input/output control device, wherein the controller may be constructed to control the shift register for transmitting to and receiving from the external apparatus the data, and characterized by at the transmission of the data, transferring the data in the transmission buffer to the shift register land outputting a shift clock to the shift register so that the serial data are transmitted if said flag shows that the transmission buffer holds the data while at the reception of the data, outputting the shift clock to the shift register in order to obtain the serial data outputted from the external apparatus, transferring the reception data in the shift register to the reception buffer, and changing the flag in the flag holding unit to show that the reception data are in the reception buffer.
The data input/output control device, wherein the controller may comprise a transmission control circuit for outputting a load signal so that the shift register is loaded with the transmission data when the flag shows that the transmission buffer holds the data at the transmission of the data, a shift clock output circuit for outputting the shift clock to the shift register when the shift register is loaded with the transmission data at the transmission of the data as well as outputting the shift clock to the shift register when a transfer ready signal is outputted from the external apparatus thereto at the reception of the data, and a reception control circuit for obtain the reception data from the shift register and changing the flag in the flag holding unit to show that the reception data are held therein.
The data input/output control device may further comprise a counter for counting the number of bits in the data to be transferred When the serial data are transferred therefrom to the external apparatus as well as the serial data are transferred from the external apparatus thereto.
The above object is also fulfilled by a data input/output control device integrating a one-chip microcomputer together with a data transfer device and a processor, the data transfer device being constructed to transmit to and receive from an external apparatus serial data and the processor processing data inputted to the data transfer device and transmitting the processed data to the data transfer device to be further transmitted to the external apparatus, the date input/output control device characterized by comprising a controller or controlling the data input and the data output of the data transfer device and a flag holding unit for holding a flag which shows if the data have been inputted to the data transfer device by one of the processor and the external apparatus.
The data input/output control device may further comprise a first synchronization circuit for synchronizing an output from the flag holding unit with the transfer clock, the output being sent to the controller, and a second synchronization circuit for synchronizing the output from the flag holding unit with the clock for the processor.
The data input/output control device, wherein the data transfer device may comprise shift register for converting a transmission data from parallel into serial and a reception data from serial into parallel, a reception buffer for holding temporarily the data which have been stored in the shift register so that they are inputted to the processor, and a transmission buffer from holding temporarily the data outputted from the processor so that they are stored in the shift register, wherein the flag holding unit holds the flag which shows if the transmission buffer holds the data at a transmission of the data as well as shows if the reception buffer holds the data at a reception of the data.
The data input/output control device, wherein the controller may be constructed to control the shift register for transmitting to and receiving from the external apparatus the data, and characterized by at the transmission of the data, transferring the data in the transmission buffer to the shift register rand outputting a shift clock to the shift register so that the serial data are transmitted if said flag shows that the transmission buffer holds the data while at the reception of the data, outputting the shift clock to the shift register in order to obtain the serial data outputted from the external apparatus, transferring the reception data in the shift register to the reception buffer, and changing the flag in the flag holding unit to show that the reception data are in the reception buffer.
The data input/output control device, wherein the controller may comprise a transmission control circuit for outputting a load signal so that the shift register is loaded with the transmission data when the flag shows that the transmission buffer holds he data at the transmission of the data, a shift clock output circuit for outputting the shift clock to the shift register when the shift register is loaded with the transmission data at he transmission of the data as well as outputting the shift clock to the shift register when a transfer ready signal is outputted from the external apparatus thereto at the reception of the data, and a reception control circuit for obtaining the reception data from the shift register and changing the flag in the flag holding unit to show that the reception data are held therein.
The data input/output control device may further comprise a counter for counting the number of bits in the data to be transferred when the serial data are transferred therefrom to the external apparatus as well as the serial data are transferred from the external apparatus thereto.
The above object is also fulfilled by a one-chip microcomputer comprising a data transfer device or serial data transmitted to and received from an external apparatus, a data input/output control device for controlling the data transfer device, and a processor for an input and an output of the data via the data transfer device, the one-chip microcomputer characterized by the data input/output control device utilizing a transfer clock as an action clock in order to control the input an the output of the data transfer device, the transfer clock generated by the external apparatus and being slower than the processor clock for the processor.
The data input/output control device may comprise a controller for controlling the data input and the data output of the data transfer device, and a flag holding unit for holding a flag which shows if the data have been inputted to the data transfer device by one of the processor and the external apparatus.
The data input/output control device may further comprise a first synchronization circuit for synchronizing an output from the flag holding unit with the transfer clock, the output being sent to the controller, and a second synchronization circuit for synchronizing the output from the flag holding unit with the clock for the processor.
The data input/output control device, wherein the data transfer device may comprise a shift register for converting a transmission data from parallel into serial and a reception data from serial into parallel, a reception buffer for holding temporarily the data which have been stored in the shift register so that they are inputted to the processor, and a transmission buffer for holding temporarily the data outputted from the processor so that they are stored in the shift register, wherein the flag holding unit holds the flag which shows if the transmission buffer holds the data at a transmission of the data as well as shows if the reception buffer holds the data at a reception of the data.
The data input/output control device wherein the controller may be constructed to control the shift register for transmitting to and receiving from the external apparatus the data, and characterized by at the transmission of the data, transferring the data in the transmission buffer to the shift register and outputting a shift clock to the shift register so that the serial data are transmitted if said flag shows that the transmission buffer holds the data while at the reception of the data, outputting the shift clock to the shift register in order to obtain the serial data outputted from the external apparatus, transferring the reception data in the shift register to the reception buffer, and changing the flag in the flag holding unit to show that the reception data are in the reception buffer.
The data input/output control device, wherein the controller may comprise a transmission control circuit for outputting a load signal so that the shift register is loaded with the transmission data when the flag shows that the transmission buffer holds the data at the transmission of the data, a shift clock output circuit for outputting the shift clock to the shift register when the shift register is loaded with the transmission data at the transmission of the data as well as outputting the shift clock to the shift register when a transfer ready signal is outputted from the external apparatus thereto at the reception of the data, and a reception control circuit for obtaining the reception data from the shift register and changing the flag in the flag holding unit to show that the reception data are held therein.
The data input/output control device may further comprise a counter for counting the number of bits in the data to be transferred when the serial data are transferred therefrom to the external apparatus as well as the serial data are transferred from the external apparatus thereto.
The data input/output control device constructed the above utilizes as a clock the transfer clock generated by the external apparatus in order to control the input and the output of the data transfer device, the transfer clock being slower than the processor clock for the processor.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, advantages and features of the invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings which illustrate the preferred embodiments of the invention. In the drawings:
FIG. 1 is a block diagram illustration showing construction of a conventional serial interface, the processor, and the external apparatus.
FIG. 2 is a time chart of the clocks utilized by the conventional data input/output device of FIG. 1.
FIG. 3 is a time chart of the control signals utilized by the conventional data input/output device of FIG. 1.
FIG. 4 is a block diagram illustration showing construction of a serial interface, the processor, and the external apparatus, according to a preferred embodiment of the present invention.
FIG. 5 is a block diagram illustration showing construction of a shift register utilized in the embodiment of FIG. 4.
FIG. 6 is a block diagram illustration showing construction of a controller utilized in the embodiment of FIG. 4.
FIG. 7 is a time chart of timing signals utilized for output of data in the embodiment of FIG. 4, according to the present invention.
FIG. 8 is a time chart of timing signals utilized for input of data in the embodiment of FIG. 4, according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A construction of a serial interface, a processor and an external apparatus according to the present invention is shown in FIG. 4, as shown in the figure, the serial interface between the processor 103 and the external device is: a data input/output data control device 10 and a data transfer device 11. The input/output control device 10 includes all the units except the output buffer 130, shift register 140 and input buffer 150, which make up the data transfer device 11.
Data is received from or sent to an external apparatus 100, which could be a A/D converter, or other processors, for example.
A transfer clock signal 101 is supplied by the external apparatus 100 to the controller 110.
A transfer control signal 102 indicates that transfer of data to the external apparatus 102 is permitted.
A processor 13 reads the data in an input buffer 150, writes the data into an output buffer 130 refers to or resets a flag circuit 170, and executes other operations and processes.
A processor clock 104 is for an operation of the processor 103.
A controller 110 outputs control signals to control the embedded-type data input/output control device 10, which is synchronized with the transfer clock signal 101.
A ready signal 111 is outputted from the controller 110 to show that the input or the output of the data is ready.
An output buffer 130 holds the data of n bits (n is a positive integer, for example, 24) to be outputted from the processor 103 to the external apparatus 100.
A shift register 140 obtains the data of n bits outputted from the output buffer 130, which is synchronized with the transfer clock signal 101 in accordance with a transmission data load signal outputted from the controller 110. The shift register 140 shifts the data in the direction of the most significant bit (MSB), one bit at one time, in accordance with a shift clock signal 211, which is synchronized with the transfer clock signal 101.
A construction of the shift register 140 is described with reference to FIG. 5. As shown in the figure the shift register 140 comprises a shifter 200 and a latch circuit 201. The shifter 200 is loaded with parallel data from the output buffer 130 (FIG. 4) or serial data, one-bit at a time at a S in terminal (the least significant bit, LSB, side), when transmission data load signal 216 becomes active. The data is shifted in the direction of the MSB at a falling edge of the shift clock signal 211. The shifter outputs one-bit data located at the MSB from a S out terminal (the MSB side) to the latch 201. The latch circuit 201 latches the data shifted out by the shifter 200 and outputs the serial data on output line 141 to the external apparatus, at a rising edge of the shift clock signal 211. That is, transmission data is output from the latch circuit 201 at the rising edge of clock 211 while reception data from an external apparatus 100 in input to the shifter 200 at the falling edge. Furthermore, the shift register 140 shifts he transmission data output on line 141 at the rising edge Of the shift clock signal 211 and shifts the reception data on line 142 at the falling edge of shift clock signal 211.
A serial data stream, one-bit at a time, starting with the MSB of the shift register 140 are outputted over line 141 to the external apparatus 100.
A serial data stream, one-bit at a time, is transferred from the external apparatus 100 to the LSB position at S n of the shift register 140 over line 142.
An input buffer 150 (FIG. 4) obtains the data of n bits loaded into the shift register 140, in parallel in synchronism with the transfer clock signal 101 and the shift clock signal 211 outputted from the controller 110.
A down counter 160 (FIG. 4) is set with an initial number m (0<m≦n; m is an integral number) at the start of a count down of the bits in the data, and reduces m by one in accordance with a count clock signal 112 outputted from the controller 110.
A flag circuit 170 is set with a flag set signal 171 from the controller 110 and is reset with a flag reset signal 172 from the processor 103. The flag set signal 171 is synchronized with the transfer clock signal 101. The flag reset signal 172 is synchronized with the processor clock 104.
A synchronization means 181 synchronizes timing of the flag circuit 170 with the transfer clock signal 101.
A synchronization means 182 synchronizes the timing of the flag circuit 170 with the processor clock 104.
A flag circuit 183 is output from the flag circuit 170 via the synchronization means 181.
A construction of the controller 110 is described with reference to FIG. 6.
A terminal count signal 112 is outputted from the down counter 160 when it counts 0.
A reception data load signal 113 transfers the data in the shift register 140 to the input buffer 150.
A shift clock/count clock signal 211 orders a shift of the shift register 140 or a counting of the down counter 160.
A transmission data load/initial number load signal 212 orders a transfer of the data from the output buffer 130 to the shift register 140 or a load of the number to be counted down by the down counter 160.
A state transition control circuit 301 controls the data input/output control device 10 and the data transfer device 11 depending on the state of the data transferred between the device 11, the processor 103, and the external apparatus 100.
An AND circuit 302 outputs the transfer clock signal 101 as the shift clock/count clock signal 211 when the transfer control signal 102 and the ready signal 111 becomes active.
An input buffer control circuit 303 activates the transmission data load/initial number load signal 113 so that the input buffer 150 is loaded with the data in the shift register 140 when he flag signal 183 is 0 and the down counter 160 counts 0 at the reception of data, the activation being synchronized with the transfer clock signal 101.
The serial interface as described above is operated to output data or input data. The operations are described hereunder with reference to the drawings.
Data Out
The processor 103 writes in the output buffer 130 the data to be outputted to the external apparatus 100 and resets the flag circuit 170 with the flag reset signal 172 so that the controller 110 is informed that data is held in the output buffer 130. The output signal of the flag circuit 170 is synchronized with the transfer clock signal 101 by the synchronization means 181 which generates the flag signal 183. The flag signal 183 is then inputted to the state transition control circuit 301 in FIG. 6 and is sampled thereby at a falling edge of the transfer clock signal 101. Then the state transition control circuit 301 refers to the flag signal 183. If the flag signal 183 is 0, the state transition control circuit 301 outputs a binary 1 as the ready signal 111, so that the external apparatus 100 is informed that the transmission of the data is ready. Detecting the binary 1 ready signal 111, the external apparatus 100 outputs a binary as the transfer control signal 102 to show that the reception of the data is ready.
Detecting the binary 1 of the transfer control signal 102, the state transition control circuit 301 activates the transmission data load/initial number load signal 212. Directed by the signal 212, the data is transferred from the output buffer 130 to the shift register 140 at the rising edge of the transfer clock signal 101 shown by (p) in FIG. 7 (FIG. 7 is a reference for timing of output executions), and the first bit of data from shift register 140 is outputted over line 141 to the external apparatus 100. Simultaneously, the initial number of bits loaded into the shift register 140 is set to the down counter 160. The flag circuit 170 is set with the flag set signal 171 to show that the output buffer 130 is ready to receive new data.
The state transition control circuit 301 refers to the transfer control signal 102. If the transfer control signal 102 holds a binary 1, the state transition control circuit 301 outputs the shift clock/count clock signal 211, which is executed at (b) timing in the figure. Directed by the signal 211, the data in the shift register 140 is shifted in the direction of the MSB by one bit at the rising edge of the transfer clock signal 101, shown at (q) in the figure, and the second bit of data is outputted over line 141. Simultaneously a number m-1, obtained by reducing the initial number m by one, is held by the down counter 160. If the transfer control signal 102 is a binary 0, the state transition control circuit 301 does not output the shift clock/counter clock signal 211 so that the shift register 140 is not operated. The above operations are repeated until (m+1)th data are outputted (until the down counter 160 counts 0).
Inputted with the terminal count signal 112, the state transition control circuit 301 refers to the flag circuit 170. If the flag circuit 70 is reset to show that data is in the output buffer 130, the state transition control circuit 301 activates the transmission data load/initial number load signal 212 so that the data in the output buffer 130 is transferred to the shift register 140, and sets the flag circuit 170 with the flag set signal 171. Simultaneously the initial number m is set to the down counter 160. If the flag circuit 170 is set to show tat no data is in the output buffer 130, the state transition control circuit 301 outputs a binary for 0 the ready signal 111 so that the external apparatus is informed that the output of the data is completed, which is executed at (c) in the figure.
The processor 103 refers to a status of the flag circuit 170 via the synchronization means 182. If the flag circuit 170 is reset to show that data is in the output buffer 130, the processor 103 does not write any data into the output buffer 130. If the flag circuit 170 is set, the processor 103 writes data into the output buffer 130 and resets the flag circuit 170.
Data In
The processor 103 reads the data in the input buffer 150 and then resets the flag circuit 170 with the reset signal 172 outputted at the timing of the processor clock 104 to show that no data is held in the input buffer 150.
Informed via the synchronization means 181 that the flag circuit 170 is reset at the rising edge of the transfer clock signal 101, the state transition control circuit 301 outputs a binary 1 for the ready signal 111 to show that the data is ready to be inputted, which is executed at (a) timing in FIG. 8. (FIG. 8 is a reference for timing of input executions). Detecting the binary 1 ready signal 111, the external apparatus 100 outputs the first bit of data on line 142 at the rising edge of the transfer clock signal 101, and then outputs a binary 1 for the transfer control signal 102.
Detecting the binary 1 transfer control signal 102, the state transition control circuit 301 outputs the shift clock signal/count clock signal 211 and activates the transmission data load/number load signal 212, which is executed at (b) in FIG. 8. Directed by the signals 211 and 212, the data in the shift register 140 is shifted in the direction of the MSB by one bit at the falling edge of the transfer clock signal 101, which is shown by (p) in FIG. 8, and the first bit of data on line 142 is inputted to the LSB position of the shift register 140. Simultaneously the initial number m is set to the down counter 160 at the falling edge of the transfer clock signal 101, shown by (p) in the FIG. 8.
The state transition control circuit 301 refers to the transfer control signal 102. If the transfer control signal 102 holds a binary 1, the state transition control circuit 301 outputs the shift clock/count clock signal 211, which is executed at (c) in FIG. 8. Directed by the signal 211, the shift register 140 shifts the data in direction of the MSB by one bit at the falling edge of the transfer clock signal 101, shown by (q) in FIG. 8, and the down counter 10 holds the number m-1 at the falling edge of the transfer clock signal 101, shown by (q) in FIG. 8. If the transfer control signal 102 is a binary 0, the state transition control circuit 301 does not output the shift clock/count clock signal 211 so that the shift register 140 is not operated.
The operation described above is repeated until the (m+1)th data bit is inputted (the down counter 160 counts 0).
Inputted with the terminal count signal 112 at the rising edge of the transfer clock signal 101, the controller 110 refers to the status of the flag circuit 170. If the flag circuit 170 is reset to show that no data is in the input buffer 150, the controller 110 outputs the reception data load signal 3 so that the data in the shift register 140 is transferred to the input buffer 150, and the flag circuit 170 is set. Simultaneously the controller 110 outputs the transmission data load/initial number load signal 22 to the down counter 160 so that the initial number m is set to the down counter 160.
If the flag circuit is set to show that the data in the input buffer 150 has not been read by the processor 103, the controller 110 outputs a binary 0 for the ready signal 111 so that the external apparatus 100 is informed that the input of the data is completed.
The processor 103 refers to a status of the flag circuit 170 via the synchronization means 182. If the flag circuit 170 is reset to show no data is in the input buffer 150, the processor 103 does not read data therefrom. If the flag circuit 170 is set to show new data is held in the input buffer, the processor 103 reads the data and resets the flag circuit 170.
The input and output of the data may utilize other devices or methods instead of the flag circuit which reflects the statuses of the input and the output buffers.
Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. These various changes and modifications do not depart from the spirit and scope of the present invention, as set forth in the appended claims.
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The present invention provides a data input/output control device integrating a one-chip microcomputer together with a data transfer device and a processor, the data transfer device being constructed to transmit to and receive from an external apparatus serial data and the processor processing data inputted to the data transfer device and transmitting the processed data to the data transfer device to be further transmitted to the external apparatus, the date input/output control device characterized in that a clock of the data input/output control device for an operation thereof is a transfer clock utilized by the external apparatus and the transfer clock is slower than a clock for the processor.
The data input/output control device comprises a controller for controlling the data input and the data output of the data transfer device, a flag holding unit for holding a flag which shows if the data have been inputted to the data transfer device by the processor or the external apparatus, a first synchronization circuit for synchronizing an output from the flag holding unit with the transfer clock, the output being sent to the controller, and a second synchronization circuit for synchronizing the output from the flag holding unit with the clock for the processor.
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