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BACKGROUND OF THE INVENTION
A. Field
The present invention relates to a drive system for a group of machines each equipped with a drive motor connected by control devices to a DC power source.
B. Related Art
Applying DC power to the drive motor(s) of a machine, for instance a weaving machine, is known. In this procedure AC power is converted by a rectifying unit of the particular machine into DC. This DC is applied by controlled switching units to the weaving machine's drive motor. Said drive motor preferably shall be a switched reluctance motor. Preferably such a weaving machine also contains a capacitive energy buffer connected to the output of the rectifying unit and to the input of the switching units. As a result, the power output beyond the rectifying unit may remain nearly constant even when the power applied to the weaving machine's main drive motor varies. The power applied to said main drive motor of a weaving machine varies according to a periodic motion of said weaving machine because it contains components that are moved in one or the other direction at predetermined times.
The above described drive system meets requirements for weaving. However it is less than desirable for electrically decelerating the weaving machine's main drive motor. For example, the main drive motor must be decelerated to reduce its speed during weaving or to stop it. In such a case the energy buffer must store the energy released by electrically decelerating the main motor. Therefore an energy buffer of high capacity and/or ability to tolerate high voltages will be required.
As regards rapidly operating weaving machines, it is nearly impossible to store the total energy released during deceleration into an energy buffer. Either an energy buffer of very large capacity would be needed, or the energy buffer's voltage would be too high. To preclude excessively high energy buffer voltages, it is known in the state of the art to couple a resistor in parallel with the energy buffer when said buffer's voltage becomes excessively high, whereby energy is removed from said buffer and converted into heat in said resistor. When the main drive motor of a weaving machine must be frequently decelerated, there will be danger that the resistor temperature will become excessive. Moreover the heat dissipated by such a resistor must be absorbed by air-conditioning equipment in the weaving room. This aspect again requires expenditure of relative large amounts of energy.
BRIEF SUMMARY OF INVENTION
The objective of the present invention is to improve a drive system of the above cited kind.
This goal is attained in that the electrical power source inputs of the control devices of the drive motors of a group of machines are interconnected by electric lines in order to carry out power swapping.
The drive system of the invention offers the advantage that the portion of the energy which is released during deceleration by one of the machines of a group may be utilized by another machine in said group. In this case any installed energy buffer need absorb less energy and/or any resistor used need not be switched onto said buffer.
In a preferred embodiment of the invention, each machine is fitted with a rectifying unit mounted between an AC power source and the inputs of the particular control devices of said machines. The inputs to the control devices are interconnected, and the rectifying units may cooperate to apply that power, for instance, required to start or to accelerate one of the machines.
In another preferred embodiment of the invention, one energy buffer is allocated to the inputs of the control devices of each machine. In this way the size of the individual energy buffers may be reduced. Using energy buffers of lesser capacity offers the advantage that these shall contain fewer pollutants. Because the energy buffers of the individual machines may swap energy among one other, they operate in the form of the sum of their capacities. As a consequence of being connected to one another, the total capacity of all energy buffers also may be reduced. Furthermore the interconnection of the energy buffers allows drawing on the energy stored in each of them to start or accelerate a machine. In the latter case the rectifying units are not required to apply the full power needed to start or accelerate a machine. Also, using one rectifying unit for each machine, it becomes feasible to keep the power substantially constant from each rectifying unit even when only a smaller energy buffer is used per machine.
In yet another embodiment of the invention, each machine is combined with a resistor connected by switching units to the input of its respective control device and/or its respective energy buffer. When energy must be dissipated as heat, this heat can spread over the individual, switched-on resistors.
In another embodiment of the present invention, one joint resistor is allocated to a group of machines and is connected by switching units to the inputs of the control means. Said single resistor may be installed at a remote location, for instance outside the weaving room. In this manner the heat dissipated by this resistor need not be absorbed by the weaving room's air-conditioning equipment.
In yet another embodiment of the present invention, one joint rectifying unit is mounted between an AC source and the inputs of the control devices of the machines. In this design the power may be applied in part or in whole through the joint rectifying unit which illustratively converts AC into DC with very high efficiency.
In yet another embodiment of the present invention, an inverter is mounted between control devices of the machines of a group and an AC power source. This inverter converting DC into AC allows feeding the energy recovered during deceleration back into the AC power source. While a single inverter suffices for one group of machines, the inverter may be selected as a more elaborate and correspondingly costlier inverter for recuperating said energy instead of converting it into heat by means of simpler and more economical resistors.
In still another embodiment of the present invention, the inputs of the control devices of the group's machines cooperate with one joint energy buffer.
Preferably the rectifying unit(s) shall each be fitted with a semiconductor forming a DC current at a defined source voltage.
In a preferred embodiment of the present invention, the group's machines are weaving machines of which the main drive shafts preferably are each directly coupled to the associated drive shafts of the drive motors.
DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention are elucidated in the description below and in relation to the illustrative embodiments shown ion the drawings.
FIG. 1 schematically shows a group of weaving machines equipped with a drive system of the invention, and
FIGS. 2–5 schematically shows variants of the drive system of the invention applied to groups of machines.
DETAILED DESCRIPTION
The drive system 1 of FIG. 1 electrically powers a group of machines 2 , 3 and 4 from an AC power source 5 . Illustratively the power source 5 is a conventional 380-volt power line at 50 Hz frequency. A rectifying unit 6 is allocated to each machine 2 , 3 and 4 converting the AC from the power source 5 into DC. The rectifying units 6 each are connected to the inputs 7 of control devices 8 which apply DC to the particular drive motors 9 of the machines 2 , 3 and 4 . Each machine 2 , 3 and 4 contains at least one component 10 driven in periodic motion, that is, moving in one direction or the other at a given time or being raised or lowered at a given time. The electric drive motor 9 of each of the machines 2 , 3 and 4 is correspondingly driven into periodic motion in that appropriately power having a periodic time-function shall be applied in a controlled manner by means of the control devices 8 to the drive motor(s) 9 . In particular the time-function of applied power is controlled in a manner such that the torque will be constant.
In this embodiment the drive motor 9 is a switchable reluctance motor and as a result the control devices 8 each are a switching unit. Each machine 2 , 3 , 4 is fitted with a control unit 11 applying to the control devices 8 (switching units) certain control parameters retrieved from a memory whereby the power is applied in periodic manner to the reluctance motor 9 . In this process the switchable reluctance motors 9 are controlled according to the machine angular positions in a motion such that, by means of the control devices 8 (switching units), predetermined windings of the switchable reluctance motor 9 shall be coupled during a predetermined time interval to the output of the rectifying unit 6 . The above term “motion” denotes the change in angular position of the switchable reluctance motor 9 . In particular this motion is matched to the natural motion of the machine's components.
In the shown embodiment, the machines 2 , 3 and 4 each are fitted with an angular-position detector 12 determining the angular position of the main drive shaft of the particular machine 2 , 3 and 4 . These angular-position detectors 12 of each machine 2 , 3 and 4 are coupled to the respective control units 11 . In this manner the control devices 8 (switching units) of each machine 2 , 3 and 4 can be actuated as a function of the signal from the associated angular-position detector 12 displaying the angular position of the particular machine 2 , 3 and 4 . Also, it is possible to determine the angular positions of the machines 2 , 3 and 4 by determining the angular positions of the respective drive motors 9 . As shown in FIG. 1 , the control units 11 of the particular machines 2 , 3 and 4 also may be connected to a central control unit which for instance is set up remotely from the machines 2 , 3 and 4 and which is connected by a network link with the control units 11 of the individual machines.
The patent document WO 98/31856 (see U.S. Pat. No. 6,247,503) discloses a drive motor of which the drive shaft is directly connected to or even is integral with the weaving machine's main drive shaft. The patent document WO 99/27426 (see U.S. Pat. No. 6,525,496) discloses how such a drive motor is powered into a specific motion, namely the power applied to this drive motor is controlled as a function of the angular position of said machine. This driving mode is preferred also with respect to the machines of a group that are driven by the drive system of the invention. For these reasons the contents of the patent document U.S. Pat. No. 6,525,496 are hereby declared to be part of the present application.
The electrical power source inputs 7 of the control devices 8 and hence the outputs of the individual rectifying units 6 of the group of machines 2 , 3 and 4 are interconnected by an electric line 14 , as a result of which DC can flow between the group's machines 2 , 3 and 4 and also may be swapped. Therefore the DC power of one of the rectifying units 6 may pass into the individual machines 2 , 3 and 4 of the said group to thereby optimize the power consumption of the motors of the group.
In a preferred embodiment of the invention, each rectifying unit 6 comprises a number of semiconductors which may or may not be controlled, for instance a number of diodes which convert AC into DC with a defined power source voltage. To avoid that one of the rectifying units 6 be excessively loaded, advantageously rectifying units 6 are used that will supply DC of substantially the same voltage. Therefore identical rectifying units 6 will be preferably used for the individual machines 2 , 3 , 4 .
The electric line 14 shall be of sufficient diameter and therefore have sufficiently low impedance so that the power may be transmitted in near lossless manner. With respect to weaving machines, such a line 14 shall supply a power of at least 3 kW without being significantly and constantly heated by that transmission. Illustratively lines of copper of several mm in diameters are appropriate.
In the embodiment of FIG. 1 , each machine 2 , 3 and 4 contains an electrical energy buffer 15 mounted between the particular output of the rectifying unit 6 and the input 7 of the associated control device 8 . Each of said buffers 15 illustratively is in the form of a capacitor which may store and release energy. The energy contained in each energy buffer 15 may be fed to one of the drive motors 9 of one of the machines 2 , 3 or 4 . The energy released when decelerating a drive motor 9 of one of the machines 2 , 3 or 4 also may be fed to one of the energy buffers 15 still able to accept it. This energy storage is not restricted to one energy buffer mounted at one of the particular machines 2 , 3 or 4 . Consequently any one of the machines 2 , 3 or 4 when required to apply peak power may draw energy from the energy buffers 15 and furthermore from the rectifying units 6 of each of the other machines.
The energy released during braking or during deceleration of a particular machine may be fed to another machine of the same group, as a result of which the energy buffer(s) 15 are not required to reabsorb the entirety of the said released energy and/or so that additional resistors dissipating energy into heat will not be needed. This feature is appropriate foremost as regards weaving machines of which the operational rate must be periodically reduced according to a given pattern being woven. Illustratively such shall be the case when weaving in several colors, whereby a given filling must be woven at a lower speed. The energy stored in the energy buffers of such weaving machines must also be available in order to raise again the operational speed of the weaving machine. As regards a weaving machine of which the operational speed varies according to a given pattern, for instance between 1,200 and 900 picks a minute, approximately 3 joules are released in deceleration. This released energy is partly stored in the energy buffers 15 and is partly absorbed by the other machines.
The drive system of the invention only rarely is susceptible to the need of converting released energy into heat by connection to a resistor. However such a case may arise if several machines are to be stopped simultaneously. For the sake of safety and as shown in FIG. 2 , a resistor 16 is provided for each machine 2 , 3 and 4 and is connected by switching units 17 to the outputs of the rectifying units 6 and to the inputs 7 of the control devices 8 . In this manner each resistor 16 is also connected to the energy buffers 15 . The switching units 17 are controlled by the central control unit 13 . All resistors 16 may be switched ON in the event the voltage of the energy buffers 15 becomes excessive. Such a voltage value is measured by a voltmeter 18 connected to the control unit 13 and to the inputs 7 of the control devices 8 . Furthermore temperature sensors hooked up to the control unit 13 may be associated with the resistors 16 . In that case and as a function of the temperature of each resistor 16 , the control unit 13 may switch ON the resistor 16 at the lowest temperature if the voltage across the energy buffers 15 is excessive.
Only one resistor 19 is allocated to the group of machines 2 , 3 and 4 in the embodiment mode shown in FIG. 3 , and can be coupled by the switching unit 20 with the inputs 7 of the control devices 8 of said machines 2 , 3 and 4 . Appropriately this single resistor will be mounted outside the room housing the machines 2 , 3 and 4 , in particular to avoid loading the air-conditioning equipment for that room. The embodiment mode of FIG. 3 furthermore includes a joint rectifying unit 22 of which the output 21 is connected to the line 14 which in turn is connected to the inputs 7 of the control devices 8 .
The basic design of FIG. 4 corresponds to that of FIG. 1 . However it includes furthermore an inverter 23 which upon voltages at the inputs 7 of the control devices 8 being reached or exceeded, will convert DC into AC that shall be fed into the AC power source 5 . This inverter 23 is configured between the inputs 7 of the control devices 8 and the AC power source 5 . In such a design, the resistors 16 and/or 19 may be eliminated. As regards a drive system 1 of the invention, the eventuality of having to feed power back into the power source 5 is remote. Accordingly a relatively small inverter 23 may be used, that is, one which may be smaller than if each machine 2 , 3 , 4 were fitted with an inverter and required to feed back energy being released at that machine.
A joint energy buffer 24 in FIG. 4 replaces the previous individual energy buffers 15 and is connected both to the inputs 7 of the control devices 8 and to the outputs of the rectifying units 6 .
The embodiment of FIG. 5 substantially corresponds to that of FIG. 3 . However in this latter embodiment, the machines 2 , 3 and 4 are not fitted with their own rectifying unit 6 . Instead a centrally located rectifying unit 22 is connected between the AC power source 5 and the line 14 . The output 21 of rectifying unit 22 is connected to the line 14 connecting the inputs 7 of the control devices 8 .
Obviously the invention is not restricted to a group of three machines 2 , 3 , 4 . At least two machines are needed. However the invention's advantages shall be greater the more machines belonging to one group are serviced by the drive system of the invention.
In the shown and above discussed embodiments, each machine 2 , 3 , 4 is fitted with only one drive motor 9 . However several drive motors may be used for each machine to drive specific components of that machine. The power applied from the power source to the individual drive motors may be considered equivalent to one equivalent power applied to a single fictitious drive motor of the particular machine.
The individual embodiments discussed above also may be combined within the scope of the present invention. Machines other than weaving machines also are applicable, that are powered and decelerated by a drive motor, for instance compressors equipped with an electric drive motor.
As regards the drive systems of FIGS. 1 through 4 , the rectifying units and energy buffers of each machine may be designed for a physical size for an average applied power and for storage of average energy. They need not be designed for storing energy peaks when a machine is being decelerated or to supply peak power when starting a machine. On account of such a compact design, the electric efficiency of each rectifying unit of the group of machines will be improved. The invention also allows limiting the fluctuations in the power to be applied by each rectifying unit, and this feature also improves electrical efficiency.
The drive system of the present invention is especially appropriate for a group of machines of which the central control unit 13 contains means driving the electric drive motors 9 of the group machines 2 , 3 and 4 in periodic motions. In an especially advantageous manner, the periodic motions of the individual machines 2 , 3 4 of said group will be matched to one another in a manner so as to limit the total power applied to the group of machines 2 , 3 , 4 at a predetermined limit. In that case said value illustratively shall be a maximum value and/or a maximum change of the total applied power. The power applied to the drive motors 9 of the individual machines 2 , 3 , 4 can be controlled in a way disclosed in the patent document WO 99/27426 (U.S. Pat. No. 6,525,496), wherein additionally the motions of the individual machines are matched to each other, for instance by the central control unit 13 , for instance being phase-shifted. This feature can be implemented by controlling the mutual angular positions of the various machines. In other words, the particular motion of one machine will be matched to the motions of the other machines in a way that the instant at which one machine absorbs maximum power will not coincide with the instant at which another machine of the group also absorbs maximum power. As a result, the power applied by each rectifying unit may be kept nearly constant even when using a comparatively small energy buffer for each machine.
The invention offers the further advantage that a single machine together with its rectifying unit 6 and any energy buffer 15 and/or any resistance 16 that might be associated to it will work well per se, but, on account of the line 14 in the group, will operate even more efficiently. For that purpose and as regards the embodiments of FIGS. 1 through 4 , not only are lines provided for the AC power source 5 between the individual machines, but also lines 14 for DC.
The invention also applies to a group of machines that are not decelerated using electric drive motors. In that case the invention is advantageous to start a machine, in particular if driven in periodic motions.
However the drive system of the invention is especially appropriate for weaving machines. It allows improving electrical efficiency of a group of weaving machines and therefore is substantially advantageous for weaving mills.
The apparatus of the invention is not restricted to the shown and described embodiments. Further modifications may be resorted to within the scope of the invention.
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A drive system powering a group of machines each fitted with a rectifying unit, wherein the inputs of the control devices of the machines' drive motors are interconnected by an electrical bus which implements a power exchange. The system enables swapping current from a power supply between motors of different machines.
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This application is a continuation Application of International Application No. PCT/AU02/00154, filed Feb. 14, 2002, which claims priority from Australia Application No. PR3067, filed Feb. 14, 2001.
The present invention relates to personal entertainment arrangements and in particular to a lounge arrangement having inbuilt audio and visual arrangements.
BACKGROUND OF THE INVENTION
Home entertainment of the type including audio and visual stimulation has over time become more and more sophisticated. Nowadays, it is not uncommon, albeit not cheap, for home entertainment units to have multiple audio speakers combined with a television front or rear projection screen acting as a home theatre.
To provide a good image such units are necessarily large, occupying significant physical space and are fixed in position mainly due to their weight. They are also expensive and at times difficult to manage and repair.
Furthermore, the screens are not adapted to take into account personal seating arrangements nor are they storable away from sight when not in use.
It is therefore an object of the present invention to overcome at least some of the abovementioned problems or provide the public with a useful alternative. This is achieved by providing for a lounge or armchair having an integral image projecting apparatus adapted to project the image out and away from the armchair so that it may be viewed by a plurality of people.
SUMMARY OF THE INVENTION
Therefore, in one form of the invention there is proposed a personal entertainment unit including a seating chair having at least one arm, the arm including an aperture located at the top of the arm and a cavity within which is housed an image projecting device adapted to project an image; and a periscope having a rotatable and a fixed flap, the rotatable and fixed flaps holding mirrors, the rotatable flap being rotatably driven between a first position where it is substantially co-planar with the upper surface of the arm and a second position where it is at a substantial angle to the upper surface of the arm, the mirror on the fixed flap causing the image to be projected generally upwardly from the image projecting device and onto the mirror on the rotatable flap, the mirror on the rotatable flap when in the second position causing the image to be projected generally horizontally outwardly from said unit.
Preferably, the aperture houses the rotatable flap, which, when in the second position, enables the image to be projected outside of the arm.
Preferably, the rotatable flap, when in the first position, is flush with the upper surface of the arm and hides the image projecting device and fixed flap from view.
Preferably, the image projecting device includes a LCD screen.
Preferably, the rotatable flap is electrically driven.
Preferably, the personal entertainment unit further includes at least one additional electronic device, such as video or DVD players as well as computer processing means whose output is adapted to control an image on the LCD screen.
Of course, it is to be understood that other optical components may be necessary to ensure the LCD screen works properly. These have been discussed in applicants' previous patent applications in relation to LCD projectors, whose contents are incorporated by reference herein.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings,
FIG. 1 is a perspective view illustrating a first embodiment of a home entertainment unit including a one-seater lounge chair;
FIG. 2 is a side elevation view, illustrating a second embodiment of the present invention when used with a single seater lounge chair;
FIG. 3 is a perspective view illustrating a third embodiment of the present invention wen used with a multi-seater lounge suite;
FIG. 4 is a perspective view illustrating a fourth embodiment of a home entertainment unit having two side-by-side lounge chairs; and
FIG. 5 is a perspective view illustrating in detail the driven mirror assembly according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.
Referring to FIG. 1 there is shown a lounge chair 10 a including a seat 12 , backrest 14 , right hand side arm rest 16 and left hand side arm rest 18 . At least one armrest, in this illustration 16 , is wide enough for a cavity 20 . A trap door 22 located at the end of the arm 16 opens outwardly enabling access to and form the cavity. Located within the cavity is a visual projecting means 24 including a focussing lens 26 . The projecting means may be of a type including a LCD screen. Light 28 that has passed through the screen is projected out of the projected and onto a surface to display an image. Although not shown a plurality of optical components may be used to assist in obtaining an image. These may be chosen from various spectrum filters, polarisers and both focussing and magnifying lenses. The image generating and projecting device may be a well-known slide projector incorporating an LCD screen.
Those skilled in the art will now appreciate that when a person wishes to view a projected image all they need to do is operate the trap door and the projector housed in the lounge chair. When viewing is no longer required, the trap door is closed and the projector means is hidden from view. Not only does this provide a more attractive visual ambiance but it also protects equipment from dust, unauthorised tampering, or even removal.
In an alternate configuration, illustrated in FIG. 2 , the projector is housed towards the rear of the armrest and supported on a shelf 30 deep within the armrest. The image produced by the projector is then projected out of the armchair 10 b by the use of a first mirror 32 that projects the image upwardly to a second mirror 34 that then projects the image forwardly from the chair 10 b to display it onto screen 36 .
This configuration allows one to have other necessary devices that may assist in creating images such as a computer or games console 38 and a video/DVD player 40 . Power to such a device may be supported via electrical connection 42 , a power board 44 within the armchair 10 b providing power to various electrical devices housed within. Other devices may then be attached to the device, such as speakers (not shown).
Fan 46 may be used to provide for the necessary airflow to effect sufficient cooling of the various devices. A liftable flap 48 may provide access to the projector. This flap may also allow for better circulation of air through the chair.
Thus one can see that the present invention provides for a lounge chair that internally houses and stores both image generating and projecting means. In contrast to existing chairs that may hold such devices where a screen is provided for the individual viewing of a user, the use of a projecting means allows a much larger image to be displayed on a surface, such as a wall. This allows other people, besides the person in the chair, to view and enjoy the image.
Referring now to FIG. 3 , the equipment may very well be housed in a lounge suite 10 c rather than a chair. Such a suite may include a separate power board 50 enabling one to externally provide power to various devices. Access to equipment other than the projector may be provided by a trap door 52 located at the front of the arm housing the projecting equipment. A shelf 54 , also found in the chair illustrated in FIG. 2 , provides the necessary support for different equipment.
Access to controls or the projector is via flap 46 on top of the arm surface 36 . A door 48 allows access to video player 22 and computer processing device 28 .
In a further embodiment of the present invention, illustrated in FIG. 4 , two side-by-side lounge chairs may include a common central armrest that is adapted to house the various equipment necessary to outwardly project an image. Instead of having two separate mirrors, a periscope device 56 is provided having a pivotable mirror 58 and a fixed flap 60 also having a mirror on its inside surface. The mirrors are so aligned that when the mirror 58 is pivoted upwardly as illustrated in FIG. 4 , a forward image is projected out of the lounge suite.
Such a combination lounge chair may also include various storage compartments such as drawer 62 .
The periscope device 56 is illustrated in more detail in FIG. 5 . Mirror 64 is mounted on the inside of flap 60 whilst mirror 58 is mounted on pivotable flap 72 . Pivotable flap includes at its rear end a partially geared wheel 66 . Electric motor 68 drives said wheel 66 through gear 70 to raise the flap from a position where it is flush with a surround 74 to a position where it is at a substantially angle to the surround 74 . The flap 72 thus rotates around pivot point 76 , the amount of rotation controlled by the motor 68 .
Those skilled in the art will now appreciate that the use of a projecting means over conventional home theatre arrangements has a number of advantages and ones where a screen mounted on an arm is mounted in front and close proximity to the user.
Firstly, the image can be seen by a plurality of users rather than just the one in that position on the chair. Further, instead of expensive screens and mechanical arm couplings that are deigned to bring the screen out of the chair, an image can be simply created using a projector of the type having an LCD screen with suitable optics. Light passes through the LCD screen that imparts its image to the passing light. That light is then optically treated by use of suitable lenses to be then displayed on a screen. In this way a large image of several meters in area may be created rather cheaply as compared to front or rear projection television screens.
Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.
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A personal entertainment unit including a chair having at least one arm within which is housed a projector. The arm includes a door enabling an image to be projected from the projector outside of the arm. The door, when closed, hides the projector from view. Alternatively, the door may be located on top of the arm and a periscope configuration is used to project the image upwardly and then horizontally from the arm to be displayed on a surface. The door is generally electrically driven and, when in a closed position, is flush with the upper surface of the arm.
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SUMMARY
[0001] In certain embodiments, the present disclosure includes a container for holding and disposing of waste concrete. It is often the case that when pouring concrete from a large concrete truck that some of the unused concrete is left in the mixer and must be removed before it hardens. In addition, when the large mixers are washed, the waste that washes out must be disposed of. Containers disclosed herein provide a means of addressing these and other problems. Waste concrete may be added or washed into the containers as a slurry and allowed to harden or set in the container. When the container is full, it may be loaded onto a dump truck and hauled to an appropriate location to be dumped and disposed of. Preferred embodiments of the disclosed containers provide a front wall that is moveable with respect to the side walls and floor such that the front wall tilts and moves back when the container is lifted and dumped. This force caused by the moving front wall breaks the bond between the metal of the container and the concrete and pushed the concrete toward the rear of the container.
[0002] Throughout this disclosure, unless the context dictates otherwise, the word “comprise” or variations such as “comprises” or “comprising,” is understood to mean “includes, but is not limited to” such that other elements that are not explicitly mentioned may also be included. Further, unless the context dictates otherwise, use of the term “a” may mean a singular object or element, or it may mean a plurality, or one or more of such objects or elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
[0004] FIG. 1 is a side plan view of an embodiment of a container.
[0005] FIG. 2 is a front plan view of an embodiment of a container.
[0006] FIG. 3 is a rear plan view of an embodiment of a container.
[0007] FIG. 4 is a perspective view of an embodiment of a truck.
[0008] FIG. 5 is a perspective view of an embodiment of a truck.
DETAILED DESCRIPTION
[0009] FIG. 1 is a side plan view of a container as described herein. The container or box includes slide rails 1 , an undercarriage 2 , side walls 6 , a floor, a rear wall 11 and a front wall 10 that is moveable with respect to the side walls and floor. In preferred embodiments, the container is built to be able to contain up to 10 cubic yards of concrete with a density no greater than 145 pounds per cubic foot. The undercarriage then comprises the structural framework necessary to support the loaded weight of the box and to provide a platform for the floor of the container. The floor preferably comprises a sheet of ¼″ steel. The undercarriage also preferably comprises two or more slide rails 1 and a roller assembly 15 for unloading the contents of the container.
[0010] The A-frame assembly can also be seen from the front perspective in FIG. 2 . The front wall or forward bulkhead assembly includes an A-frame structure for attachment of the container to the lift mechanism of the truck. The A-frame includes two opposing substantially horizontal members 7 that are parallel to the long axis of the container and lie along the top of the undercarriage 2 , one near each side wall. The horizontal members are attached at their aft ends (toward the rear wall) to the undercarriage by a pivot shaft 9 , which may comprise a shaft held within a pad eye such that the shaft is able to rotate within the pad eye. The horizontal members are attached to the undercarriage at their forward ends (toward the cab) by a shaft 5 and rotation retainer 8 such that the forward end of the horizontal members can move up or down in the rotation retainer 8 as the rear ends of the horizontal members pivot around the pivot shaft 9 . This pivoting motion forces the front wall back with respect to the side walls and floor. In certain embodiments, the front wall 10 may be substantially perpendicular to the floor, or it may form an obtuse angle with the floor, in some embodiments, the front wall 10 may form an angle of about 135° with the floor.
[0011] The A-frame structure also includes two substantially upright members or legs 3 , each rigidly attached to a forward end of the respective horizontal members 7 and angled toward the midline of the container to form the apex of the “A” frame. The top of the A-frame includes an A-frame gusset 14 on either side of the Apex. A shaft 4 provides a common lifting point for attachment to the lift arm of a truck, and is held in the A-frame gussets 14 to provide the hook point for lifting and dumping the container. The A-frame also comprises a hook gusset 13 . The upright members are also rigidly attached to the front wall or bulkhead, in certain embodiments by one or more plate gussets 12 .
[0012] FIG. 3 is a rear plan view of an embodiment in which the tail gate is not shown. The tail gate is necessary to hold in the slurry and is opened prior to dumping the waste concrete. Any type of tail gate known in the art may be used. As shown in FIG. 3 , the interior of the side walls may form an angle with the floor of greater than 90° or they may be substantially perpendicular to the floor. The roller assemblies 15 may comprise rollers of 8″ diameter Schedule 60 pipe on a shaft of 1.75″ diameter shaft or equivalent materials.
[0013] FIG. 4 is an embodiment of a truck and container in which the container is being lifted as it would to dump waste concrete from the container. As seen in FIG. 4 the truck hydraulics are hooked to shaft 4 in order to lift the container up. As the container is lifted, the A-frame rotates about shaft 9 to the extent allowed by rotation retainer 8 . The lifting force and pivoting of the A-frame causes the front wall 10 to pivot toward the rear breaking the bond between the hardened concrete and the metal of the walls and floor of the container. FIG. 5 illustrates and embodiment of a truck comprising a waste concrete container in which the waste concrete is being dumped from the container. After the container has been lifted, a second hydraulic telescoping cylinder moves the container back on the roller assemblies to dump the concrete.
[0014] All of the apparatus and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the apparatus and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the apparatus and/or methods and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.
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A container for disposing of waste concrete provides a pivoting front wall assembly such that lifting the container by the front wall assembly breaks the bond between hardened concrete and the container facilitating removal of the waste concrete.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a divisional application of copending U.S. application Ser. No. 10/971,825, filed on Oct. 22, 2004.
FIELD OF THE INVENTION
The present invention relates, in general, to fluorescent marker molecules and, more specifically, to the preparation of highly fluorescent polyurethane compounds which are the reaction products of an isocyanate with fluorescent or non-fluorescent reactive polymers. These highly fluorescent polyurethane compounds provide unique markers for identifying the sources of component raw materials in fluids, fluid blends and solid compositions.
BACKGROUND OF THE INVENTION
Various colorants and dyes have been used to authenticate the composition and/or source of fluids and plastic articles. In some cases, it is preferable to use a marker or tag that is not detectable by the human eye so as to avoid interference with colored materials or to avoid detection of the additive. In such cases, it may be desirable to use marker compounds containing fluorophores that fluoresce or emit light in the ultraviolet or infrared region after excitation with an appropriate light source. For instance, U.S. Pat. Nos. 4,303,701 and 4,329,378 disclose methods for marking plastic lenses by impregnating them with fluorescent materials that do not respond to sunlight or normal visible light.
Luttermann et al., in U.S. Pat. No. 5,201,921 teach a process for identifying polyolefin plastics using lipophilic fluorescent dyes in concentrations suitable to minimize color distortions.
Markers are also becoming particularly important for protecting brand integrity for consumers. Such markers must be readily detectable at relatively low concentrations in the product. In the petroleum industry, markers are also useful for ensuring compliance with governmental regulations. For example, products such as diesel fuels, gasoline and heating oils often contain visible dyes or colorless fluorescent compounds that identify the intended use, tax status, or brand name of the product. Such markers are well known to those skilled in the art.
In addition, petroleum product markers must also fulfill other criteria such as being:
(1) soluble in hydrocarbon solvents; (2) resistant to leaching from the petroleum product by water or water that is strongly acidic or basic; (3) relatively chemically inert so as to avoid loss of color or fluorescence when in contact with other petroleum additives or water; and (4) free from interference from naturally occurring compounds already present in the petroleum product.
A number of artisans have attempted to provide acceptable fluorescent markers for use in the petroleum industry. For example, Smith, in U.S. Pat. No. 5,498,808, teaches the use of colorless fluorescent petroleum markers which are based on esterified derivatives of xanthene compounds such as fluorescein. One drawback to the markers of Smith is that fuels containing these markers must be treated with alkaline developing solutions to generate the visibly fluorescent chromophore. Other markers such as the phthalocyanine and naphthalocyanine dyes, disclosed in U.S. Pat. Nos. 5,804,447, 5,998,211 and 6,312,958, can be detected directly by their fluorescence in the near infrared (IR) region between 600 to 1,200 nm where naturally occurring components in the petroleum product will not interfere.
Carbamates or urethanes prepared with aromatic isocyanates are known to fluoresce in the ultraviolet region between 300 and 400 nm depending upon the substitution pattern of the isocyanate, solvent, and the alcohol used. Because petroleum compounds typically exhibit considerable background fluorescence at these wavelengths, urethanes have heretofore tended to be excluded from consideration as markers.
U.S. Pat. Nos. 3,844,965 and 4,897,087 disclose lubricating oil additives and ash less fuel detergents or dispersants which are said to be the reaction products of a polyether polyol and an aliphatic hydrocarbyl amine or polyamine with a polyisocyanate (i.e., polyether urethaneureas). Polyether urethane polyamines prepared from hydroxyalkylated polyamines, a polyisocyanate, and a polyether can be used as fuel additives with enhanced oxidative stability as taught by Blain et al. in U.S. Pat. No. 5,057,122. However no mention is made in any of these patents about the use of these compounds as fluorescent markers and no methods of enhancing their fluorescent response is discussed.
Polyether polyurethanes without active hydrogens have been used as plasticizers in U.S. Pat. Nos. 4,824,888, 5,525,654, and 6,403,702. These compounds are essentially diurethanes prepared by:
1) reaction of difunctional polypropylene glycol with a monoisocyanate or 2) reaction of a monofunctional monalkyl ether of polypropylene glycol with a diisocyanate.
Pantone et al., in U.S. Pat. No. 6,384,130, disclose another class of plasticizers that are the reaction products of an isocyanate-terminated prepolymer and a monofunctional alcohol. These compounds contain more than two urethane groups and the prepolymers may have a functionality greater than 2.0. The polyethers disclosed by Pantone et al. to make the polyurethanes do not contain fluorophores.
Reactive dyestuffs or colorants for plastics based on alkoxylated chromophores such as azo, triphenylmethane, and anthraquinone derivatives are disclosed in U.S. Pat. Nos. 4,284,729 and 4,846,846. The polyether derivatives provide non-migrating visible color to polyurethane articles by chemically reacting with isocyanates in the blend to become part of the polymer network. Again, no mention is made in any of these patents about the use of these compounds as fluorescent markers and no methods of enhancing or controlling their fluorescent response is discussed.
Thus, a need continues to exist in the art for colorless markers. It would be desirable if such markers had molecular structures that can be readily modified to provide fluorescence in the ultraviolet, visible, or near infrared (IR) region of the electromagnetic spectrum.
SUMMARY OF THE INVENTION
The present invention provides such markers in the form of highly fluorescent polymeric urethane or urea derivatives that fluoresce in the ultraviolet or near infrared region without being visible to the human eye at low concentrations in the fluid or article being marked. These highly fluorescent markers can be detected by techniques such as liquid or gel permeation chromatography coupled with appropriate detectors. The marker compounds are compatible with an extensive variety of materials, including petroleum products. The molecular weight and fluorescence emission wavelength of the compounds can be readily adjusted to provide a multitude of markers having unique fluorescence signatures. In addition, because the marker compounds are highly fluorescent, less of the particular compound is needed to provide an identifying signal.
These and other advantages and benefits of the present invention will be apparent from the Detailed Description of the Invention herein below.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described for purposes of illustration and not limitation. Except in the operating examples, or where otherwise indicated, all numbers expressing quantities, percentages, functionalities and so forth in the specification are to be understood as being modified in all instances by the term “about”. Equivalent weights and molecular weights given herein in Daltons (Da) are number average equivalent weights and number average molecular weights respectively, unless indicated otherwise.
The present invention provides a highly fluorescent compound containing the reaction product of at least one fluorophore-containing reactive polymer, optionally containing a polyamine unit of the formula NCH 2 CH 2 N and at least one unsubstituted or substituted aryl isocyanate or an unsubstituted or substituted aliphatic or cycloaliphatic isocyanate, at an isocyanate index of 100 or less, wherein the highly fluorescent compound emits fluorescence in the ultraviolet (UV), visible, or near infrared (IR) region.
The present invention further provides a process for producing a highly fluorescent compound involving reacting at least one fluorophore-containing reactive polymer, optionally containing a polyamine unit of the formula NCH 2 CH 2 N and at least one unsubstituted or substituted aryl isocyanate or an unsubstituted or substituted aliphatic or cycloaliphatic isocyanate, at an isocyanate index of 100 or less, wherein the highly fluorescent compound emits fluorescence in the ultraviolet (UV), visible, or near infrared (IR) region.
The present invention still further provides a process for marking one of a fluid, a fluid blend or a solid composition, involving adding to the one of a fluid, a fluid blend or a solid, the reaction product of at least one fluorophore-containing reactive polymer, optionally containing a polyamine unit of the formula NCH 2 CH 2 N and at least one unsubstituted or substituted aryl isocyanate or an unsubstituted or substituted aliphatic or cycloaliphatic isocyanate, at an isocyanate index of 100 or less, wherein the reaction product emits fluorescence in the ultraviolet (UV), visible, or near infrared (IR) region.
The present invention yet further provides a process for marking one of a fluid, a fluid blend or a solid composition, involving adding to the one of a fluid, a fluid blend or a solid, the reaction product of at least one non-fluorophore-containing reactive polymer, optionally containing a polyamine unit of the formula NCH 2 CH 2 N and at least one unsubstituted or substituted aryl isocyanate, at an isocyanate index of 100 or less, wherein the reaction product emits fluorescence in the ultraviolet (UV), visible, or near infrared (IR) region.
The highly fluorescent inventive polymeric urethane or urea derivatives fall into two classes depending upon the fluorescence characteristics of the active hydrogen compound and the type of isocyanate used.
Class I. The reaction product of a reactive polymer containing a fluorescent chromophore and an aromatic isocyanate, represented by the formula (I) below:
wherein
F represents a fluorophore;
P represents a polymeric moiety, optionally containing a polyamine unit of the formula NCH 2 CH 2 N;
X represents a reactive heteroatom chosen from O, N, and S;
n represents the number of reactive heteroatoms;
R 1 represents an unsubstituted or substituted aryl moiety; and
y represents the number of isocyanate groups.
Class II. The reaction product of a reactive polymer containing a fluorescent chromophore and an aliphatic or cycloaliphatic isocyanate, represented by the formula (II) below:
wherein,
F represents a fluorophore;
P represents a polymeric moiety, optionally containing a polyamine unit of the formula NCH 2 CH 2 N;
X represents a reactive heteroatom chosen from 0, N, and S;
n represents the number of reactive heteroatoms;
R 2 represents an unsubstituted or substituted aliphatic or cycloaliphatic moiety; and
y represents the number of isocyanate groups.
Also suitable as markers in the inventive methods are those polymeric urethane or urea derivatives which do not contain a fluorophore, but do contain an aromatic group in the isocyanate moiety, and are herein designated as Class III compounds.
Class III. The reaction product of a reactive polymer not containing a fluorescent chromophore and an aromatic isocyanate, represented by the formula (III) below:
wherein,
P represents a non-fluorophore-containing polymeric moiety, optionally containing a polyamine unit of the formula NCH 2 CH 2 N;
X represents a reactive heteroatom chosen from 0, N, and S;
n represents the number of reactive heteroatoms;
R 3 represents an unsubstituted or substituted aryl moiety; and represents the number of isocyanate groups.
y represents the number of isocyanate groups.
The highly fluorescent marker compounds of these three classes preferably have a molecular weight greater than 300 Da, more preferably between 1,000 and 50,000. The excitation wavelength to induce fluorescence is preferably greater than 210 nm and the emission wavelength is preferably greater than 290 nm. Surprisingly, the relative fluorescence of the marker compounds is greater than that expected from the simple addition of the fluorescence of the reactant fluorophores and, in some cases, may be up to seven times as much as expected. This allows for the use of greatly reduced amounts of the compounds as markers.
It is preferred that neither the reactive polymer nor the isocyanate absorb light in the visible region to the extent that any significant color is observed, but the reaction product may fluoresce in the ultraviolet below 400 nm, in the visible region, or in the near infrared above 700 nm. The highly fluorescent marker compounds are not intended to become chemically bound to the matrix in which they are used.
The chemical composition of the reactive polymer is not critical, but the reactive polymer should be soluble in the matrix in which it is to be used. Although polyesters are suitable, polyethers based on alkylene oxides or combinations of alkylene oxides such as ethylene oxide, propylene oxide, or butylenes oxide are preferred. The molecular weight of the reactive polymer should be such that the fluorescence intensity of its reaction product with an isocyanate allows detection of the compound at concentrations below 100 ppm. Preferably, the reactive polymer has a molecular weight in the range of 250 to 40,000 Da, more preferably in the range of 500 to 20,000 Da. Additionally, the functionality or number of active hydrogen atoms per molecule of reactive polymer may vary from 1 to 8. The chain length of the reactive polymer and the fluorophore may be chosen to adjust respectively the chromatographic behavior and fluorescent emission wavelength for the compound as desired. Reactive heteroatoms as used herein refers to oxygen, nitrogen or sulfur atoms of the reactive polymer which had reactive hydrogen atoms prior to reaction with the isocyanate in forming the highly fluorescent compound.
Fluorophores and methods of making them are known in the art. The fluorophore may be attached to the reactive polymer via any type of linking group such as an ester, amide, ether, etc., by means known to those skilled in the art.
In the case of the inventive Class I or the Class III compounds, the aromatic isocyanate may be mono or polyfunctional depending upon the desired molecular architecture of the reaction product. Suitable isocyanates include, but are not limited to, 4,4′-diphenylmethane diisocyanate (MOO, polymeric MOI (PMDI), toluene diisocyanate, allophanate-modified isocyanates, phenyl isocyanate, naphthalene isocyanate, naphthalene diisocyanate, isocyanate-terminated prepolymers and carbodiimide-modified isocyanates.
In the case of the inventive Class II compounds, suitable aliphatic or cycloaliphatic isocyanates include, but are not limited to, 1,6-hexamethylene-diisocyanate; isophorone diisocyanate; 2,4- and 2,6-hexahydrotoluenediisocyanate, as well as the corresponding isomeric mixtures; 4,4′-, 2,2′- and 2,4′-dicyclohexylmethanediisocyanate and 1,3 tetramethylene xylene diisocyanate.
As will be apparent to those skilled in the art, the inventive marker compounds may be made including various combinations of reactive polymers and isocyanates.
For the inventive marking methods, it is preferred that the highly fluorescent marker compounds be liquid and readily soluble in fluids. Therefore, those conditions which would produce high crosslink density or insoluble solids are preferably avoided, i.e., where n, in formulae (I), (II) or (III) is greater than one, a monofunctional isocyanate is preferred and where y is greater than one, a monofunctional polymer is preferred. If use of a diisocyanate is desired for n>1, a mixture of mono- and difunctional polymeric group is preferably used to control the molecular weight of the polyurethane product. The isocyanate index for reaction of the polymer with the isocyanate is less than or equal to 100 but a value of 100 is preferred.
The term “Isocyanate Index” (also commonly referred to as NCO index), is defined herein as the number of equivalents of isocyanate, divided by the total number of equivalents of isocyanate-reactive hydrogen containing materials, multiplied by 100, (i.e., NCO/(OH+NH)×100).
The fluorescence signature of the marker compounds may be adjusted by varying the chain length of the polymeric group, the presence or absence of fluorophore and the type of fluorophore. The highly fluorescent marker compounds may be added to the matrix to be marked in any amount depending upon the sensitivity of the detection system. The inventor herein contemplates that, with present technologies, detection may be effected at amounts of at least one part of the inventive compound per billion parts of matrix up to perhaps 100 parts per million. The matrix to be marked is virtually unlimited. Fluids, fluid blends and solid compositions (preferably before solidification has occurred) may be marked with the inventive compounds. The highly fluorescent marker compounds may be used to mark fluid blends, such as petroleum products including diesel fuel, gasoline and heating oil. Although less preferred because of a weaker signal, the inventor herein also contemplates the use of a fluorophore-containing polymer itself in the inventive marking methods.
EXAMPLES
The present invention is further illustrated, but is not to be limited, by the following examples.
Highly Fluorescent Marker Preparation Procedure
An apparatus was assembled from a three-liter resin kettle with a four-necked glass cover. A metal stirrer shaft with three Rushton turbines was inserted into the central neck. The other necks were fitted with a thermocouple, a nitrogen line, and a vacuum line. The resin kettle was inserted into a heating mantle jacket. The assembly was flushed with nitrogen for 15 minutes before charging 2,370 grams (1.483 equivalents) of polyether polyol to the resin kettle. The polyether was vacuum-stripped at 20-25 mm Hg while heating to 110° C. for two hours. The polyol was cooled to 60° C. before sufficient isocyanate was added to achieve the desired index. The mixture was heated for two to four hours at 125° C. under a nitrogen blanket. Consumption of the isocyanate was monitored by standard titration methods. The isocyanate index was varied from 90 to 100 and the amount of each reactant was dependent upon its active hydrogen content.
Fluorescence Analysis Method
High Performance Liquid Chromatography (HPLC) analyses of the highly fluorescent marker compounds were performed using a Model 1090M HPLC (Agilent Technologies) equipped with a Model 1046A Fluorescence detector. A five microliter aliquot of a 100 ppm solution of each marker compound was injected into the HPLC, which contained no analytical column and used unstabilized THF as mobile phase at a flow rate of 0.5 milliliters per minute. Because no analytical column was used, all components of each sample were unretained by the system and eluted together.
The fluorescent responses were monitored primarily at three specified wavelength combinations, namely: Excitation at 240 nm/Emission at 325 nm; Excitation at 240 nm/Emission at 310 nm; and Excitation at 230 nm/Emission at 310 nm. The photomultiplier tube (PMT) sensitivity was set at 8. Comparisons of marker compounds responses were based on peak area data.
Peak areas for the emission spectra of the marker compounds were compared to the peak area for a control to obtain the relative response ratio. The control was a polyether prepared by propoxylating nonylphenol. Although there was little difference in the response ratios when the excitation wavelength was 230 nm, various combinations of polymer fluorophores and aromatic isocyanates enhanced responses from two to nine times when excitation at 240 nm was used.
Table I details the composition of the highly fluorescent marker compounds and summarizes the results of fluorescence measurements performed at various combinations of excitation and emission wavelengths. The molecular weights listed correspond to the unreacted polymer.
TABLE I
Fluorescence in THF
Highly Fluorescent Marker Compound
Excitation 230 nm
Excitation 240 nm
Excitation 240 nm
Reactive Polymer
Isocyanate
Emission 310 nm
Emission 310 nm
Emission 325 nm
Ex. No.
Fluorophore
Funct.
MW
Funct.
Area
Ratio
Area
Ratio
Area
Ratio
C-1
nonylphenol
1
1,600
none
—
592
1.0
108
1.0
54
1.0
2
nonylphenol
1
1,600
4,4′-MDI
2
856
1.4
721
6.7
476
8.8
3
nonylphenol
1
1,600
phenyl isocyanate
1
789
1.3
211
2.0
105
1.9
4
Bisphenol A
2
3,000
phenyl isocyanate
1
1,023
1.7
344
3.2
185
3.4
5
Bisphenol A
2
3,000
1-napthyl isocyanate
1
704
1.2
200
1.9
493
9.1
6
none
1
1,600
phenyl isocyanate
1
165
0.3
126
1.2
62
1.1
7
none
1
1,600
4,4′-MDI
2
298
0.5
506
4.7
320
5.9
The foregoing examples of the present invention are offered for the purpose of illustration and not limitation. It will be apparent to those skilled in the art that the embodiments described herein may be modified or revised in various ways without departing from the spirit and scope of the invention. The scope of the invention is to be measured by the appended claims.
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The present invention provides highly fluorescent markers, made from a reactive polymer and an isocyanate, that fluoresce in the ultraviolet or near infrared region without being visible to the human eye at low concentrations in the fluid or article being marked. The molecular weight and fluorescence emission wavelength of these highly fluorescent marker compounds can be adjusted to provide a multitude of markers with unique fluorescence signatures.
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BACKGROUND OF THE INVENTION
Food cartons or containers, for use in particular in the fast food industry, are disposable items conventionally formed of lightweight paperboard folded and fixed in a predetermined configuration.
Such containers are intended for a wide variety of products. Thus, the containers have heretofore of necessity been made in a variety of configurations, for example the conventional closed single chamber clamshell for hamburgers and the like, open multi-compartment serving trays adapted to accommodate different foodstuffs to be consumed on the restaurant premises, multi-compartment covered containers to accommodate separate foods in a single closed carton, and the like.
The necessity for separate specialized containers requires maintaining sufficient storage space for an adequate supply of each of the specialized containers used by the fast food establishment. Specialized containers also require the dispenser of the food to select among multiple different types of containers with each order processed. Additional problems involve differing manufacturing techniques and equipment, separate packaging, etc.
All of the above factors contribute to increasing the expense of the products provided. This in turn is particularly undesirable with regard to fast food containers which are throwaway items, and, to be economically acceptable, should not be a major factor in determining the price of the food dispensed.
SUMMARY OF THE INVENTION
The container of the present invention is, through a unique capability of converting into forms for use in distinctly different situations, particularly desirable for a variety of reasons, all of which contribute to the economic feasibility of the container.
More specifically, the container of the invention eliminates the necessity for the manufacture and stocking of different containers, each specifically formed for a single type usage. Rather, the container of the invention, through an integral lock assembly, is convertible to accommodate distinctly different foods. The lock assembly requires no additional materials, the major cost of the product, and only a slight modification in the actual manufacturing equipment by the provision for the formation of selected cut and fold lines in blanks similar to blanks of the type conventionally used in the formation of clamshell cartons. In one form of carton to which the container of the invention can convert, an auxiliary retainer, formed of a single flat sheet or panel of paperboard or the like, can be utilized as an additional securing means as well as a display means presenting, as an example, a logo associated with the fast food establishment.
The container of the invention is folded from a single blank and includes two compartment-defining shells integrally joined along a common fold or hinge line comprising a common upper edge of the inner walls of the two shells. These inner walls are of equal height and extend perpendicularly to the base or base walls of the two shells for flush abutment against each other with the shells in adjacent alignment. The remaining or outer walls of each shell flare slightly outward relative to each other as they project from the corresponding base.
The perpendicular or 90° inner walls, joined along a common outer edge, allow for a smooth hinged folding of one shell over the other without a buckling of the inner walls relative to each other as would interfere with the smooth opening and closing of the shells relative to each other.
The resultant carton is in the nature of a clamshell carton particularly useful in providing a closed container for a single food item, most notably a hamburger or similar sandwich. As in the conventional clamshell construction, the three diverging walls of one shell will preferably be of a slightly greater height than the walls of the second shell to slightly telescope thereover and provide a sealed peripheral edge portion. Similarly, appropriate securing means, such as projecting lugs and complimentary recesses, will be provided to latch the shells in the closed position wherein a single enlarged chamber is provide.
The above-described basic container is equally adapted for use as a fixed open tray with two separate compartments. Any tendency for one shell to freely close over the other is resisted by an integral lock assembly formed within the adjacent inner walls for a locking engagement between the inner walls in the open position of the container. The locking assembly is defined directly from the portion of the blank forming the inner walls, thereby avoiding the necessity of additional material. Further, the lock assembly is easily and quickly engaged by a simple finger manipulation for a converting of the clamshell carton into an open two-compartment tray.
The described basic container is also usable with a second duplicate container in the formation of a multi-chamber closed carton. This involves inverting one open container to overlay and downwardly engage over a second open container. The containers are rotated 180° end-to-end to telescopically engage the outer portions of the projecting walls. The inner walls, and more particularly the hinge lines thereof, overlay and engage or substantially engage each other. The securing latches are configured to allow for an appropriate locking of the upper and lower reversed containers whereby two double height chambers are formed.
The inner walls of each of the containers of the closed multiple-chamber carton are preferably interlocked by the corresponding lock assemblies. As an additional retaining means, or as a means for securing the overlying containers in a stable relationship without using the lock assemblies, at least one retainer can be engaged between the overlying pairs of inner walls of the closed carton in a manner which clamps the common outer edges of the two pairs of inner walls against each other to preclude movement of the containers relative to each other. The retainer will simultaneously preclude movement of the shells of each container relative to each other whereby a highly stable multi-chamber carton is provided. The retainer will project to one side of the closed carton for easy manipulation and as a means for displaying a company logo, a decorative motif, or the like.
Other features of the invention are considered to reside in the specifics of the structure as more fully hereinafter detailed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front and top perspective view of the carton configuration of the container of the invention;
FIG. 2 is a rear perspective view of the carton of FIG. 1;
FIG. 3 is a top perspective view of the opened tray configuration of the container of the invention;
FIG. 4 is a plan view of the blank from which the container is formed;
FIG. 5 is a perspective detail of the lock assembly, prior to engagement, which fixes the container in the tray configuration of FIG. 3;
FIG. 6 is a similar perspective detail with the lock assembly engaged;
FIG. 7 is a perspective view of the container, used with a companion container to define a multi-chamber closed tray carton, the retainer is aligned for engagement with the two containers;
FIG. 8 is a similar perspective view with the retainer engaged and with portions of the upper container broken away for purposes of illustration; and
FIG. 9 is a cross-sectional detail illustrating the positioned retainer and taken generally in the plane of line 9--9 in FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more specifically to the drawings, the basic configuration of the container 10 will be best appreciated from FIGS. 3 and 4 which respectively illustrate the erected container and the unitary or one piece blank 12 from which the container 10 is folded.
The container 10 includes two shells 14 and 16, each including a planar base or base panel 18, an inner wall 20 and outer walls 22. The walls 20 and 22 of each shell are integrally joined to the base about the periphery thereof and folded to project laterally therefrom. The inner walls 20 extend perpendicular to the respective bases 18 and the walls 22 flare slightly outward. The walls 20 and 22, at the ends thereof, are joined and sealed to adjacent walls by appropriate glue flaps 24 to define outwardly opening compartments. The outer walls 22 of the shell 16 are of a greater height than the outer walls 22 of the shell 14 to allow for a smooth closing of the shell 16 over the shell 14 in the manner suggested in FIGS. 1 and 7. The inner walls 20 have a common upper edge 26 which defines a fold line forming a hinge for rotation of the shell 16 relative to the shell 14 to define the clamshell carton 28 of FIGS. 1 and 2.
The perpendicular or right angle extension of the inner walls 20 from the respective base panels 18 allow for a smooth and unencumbered opening and closing of the shells 14 and 16 relative to each other when used to define the clamshell carton 28 in which the two compartments define a single substantially double height interior chamber. Such a carton, as is the case with conventional clamshell cartons, will normally be used to contain hamburgers, single food items, and the like.
In order to releasably secure the closed shells of the carton 28, appropriate latch means will be integrally formed from the walls 22 remote from the corresponding inner walls 20. Such latch means, as illustrated, can comprise projecting tabs 30 extending from shell 14 and engaged through corresponding slots 32 in shell 16. The relationship between the latching lugs 30 and the latching slots 32 is such as to, relying on the inherent flexibility of the material of the container, allow for a latching and subsequent release of the shell 16 relative to the shell 14 as it is closed thereover. Similarly, with the container 10 fully open in the tray configuration 34 of FIG. 3, a duplicate container, inverted and turned end-for-end, can be engaged over the first container to form a dual-chamber closed carton 36 as illustrated in FIGS. 7 and 8 with the overlying containers 10 releasably secured to each other by the latch lugs and slots. With such an arrangement, the lugs 30 of one container will engage through the slots 32 of the second container in a manner readily apparent from FIGS. 7 and 8. Further, it is to be appreciated that the latch lug and slot arrangement can vary as long as the components retain the ability to both releasably latch one shell to the other and one container to the other. For example, the lugs and slots can be laterally directed rather than longitudinally directed as illustrated.
Turning again to FIG. 3 wherein the container 10 is illustrated as a dual compartment upwardly opening tray 34, the formation of the inner walls 20 perpendicular to the bases 18 allow for a flush abutment of these walls against each other in the fully opened position of the shells 14 and 16, thus providing a flat-bottom tray for the serving of two separate foodstuffs.
In order to stabilize the shells 14 and 16 relative to each other in the opened position for proper use of the container as a tray 34, provision must be made to avoid any tendency for the shells to fold or close on each other. Accordingly, the container 10 of the invention, utilizing no additional material, provides an integral lock assembly 38 in and for selective engagement between the inner walls 20. The lock assembly, when disengaged, allows free folding movement of the shells 14 and 16 relative to each other for use in the formation of the clamshell carton 28. Upon a locking of the lock assembly 38, which can only be effected in the open tray configuration of FIG. 3, the inner walls 20 are locked together in a manner whereby pivotal movement therebetween is precluded, thus providing the desired rigid two compartment or chamber tray 34.
With reference in particular to FIGS. 4, 5 and 6, it will be noted that the lock assembly 38 includes a tongue member 40 on one inner wall and an opening or recess defining member 42 on the second inner wall. The opening defining member 42 is formed by a pair of laterally spaced cut or severance lines 44 extending inward from longitudinally spaced points along the hinge-forming outer edge 26 at approximately 65° to the edge 26. The recess or opening for the tongue member 40 is formed by laterally flexing the member 42 out of the plane of the corresponding inner wall 20 to provide for accommodation of the tongue member between the severance lines 44.
The tongue member 40 includes a central portion 46 of substantially equal size and shape to the opening-forming member 42 and defined by inwardly or downwardly diverging fold lines 48 extending from points on the hinge-forming outer edge 26 common with the points from which the severance lines 44 extend. The inner or lower ends of the diverging fold lines 48 align on a transverse imaginary or defined fold line 50 paralleling the common outer edge 26. The tongue member 40 is completed by a pair of side locking tabs or ears 52 coplanar with the central portion 46 of the tongue member 40 and integral therewith along the diverging fold lines 48. Each of these tabs 52 has the outer periphery thereof defined by a cut or severance line 54. For ease of engagement and disengagement, and to provide an enhanced interlock, the tab outer peripheries taper from a maximum width immediately inward of the inner wall upper edge 26 to a substantially narrower width toward the lower or inner fold line 50. The tabs 52 project laterally beyond the opening-forming severance lines 44 to the opposite sides of the opening-forming member 42. As will be appreciated from the foregoing description and FIGS. 4-6, the lock assembly 38 includes a length of the common upper edge 26 of the inner walls 20 which provides an integral joinder between the upper ends of the tongue member 40 and member 42 for simultaneous manipulation thereof. Thus, the formation of the tongue-receiving opening or recess is effected as the tongue is engaged therethrough.
FIG. 5 illustrates the lock assembly 38 prior to engagement. As such, the inner walls 20 of the two shells 14 and 16 are, other than for the hinge defined along the common upper edge 26, free of each other for use of the container 10 as a clamshell carton 28.
FIG. 6 illustrates the lock assembly engaged. In engaging the lock assembly 28, lateral pressure is applied to the tongue member 40 toward the member 42 to flex the member 42 laterally away from the corresponding inner wall 20. The member 42 folds about either an imaginary or a defined fold line between the lower ends of the severance lines 44. Continued pressure on the tongue member moves the tongue member through the defined opening between the severance lines 44 with the inherent resiliency of the paperboard material allowing the lock tabs 52 to flex toward each other for forced reception through the opening. Once beyond the opening, the tabs tend to unfold and return to their original position. This unfolding movement of the tabs 52 is enhanced by the inherent tendency of the tongue member 40 to retract from the opening, thereby providing for a positive engagement of the tabs against the inner face of the wall 20 from which the member 42 is defined. The engaged lock assembly provides a positive interlock between the two abutting inner walls 20 whereby movement of the hinge-joined shells 14 and 16 relative to each other is prevented, and the container 10 is fixed in a configuration defining a dual chamber upwardly opening tray, the interior of which is divided by a fixed central partition comprising the interlocked inner walls. Should a customer wish to use the tray 34 as a "take out" container for a partially consumed meal, the lock assembly 38 can be easily disengaged by forcing the tongue member back through the opening and closing one shell upon the other.
Depending upon the size of the container, more than one lock assembly 38 can be provided along the length of the engaged inner walls 20.
FIGS. 7 and 8 illustrate the use of two of the containers 10 in the formation of a closed two-chamber carton 36. The latch assemblies 30, 32 allow for a latching of the two containers to each other upon a reversing and inverting of the uppermost container, thereby providing two enlarged interior chambers separated by a transverse partition consisting of the abutting upper and lower pairs of inner walls 20 which engage each other along the two outer edges 26 as best seen in FIGS. 8 and 9. While the engaged containers will maintain a stable relationship, to avoid any tendency for the individual containers 10 to fold, particularly when separating the containers or opening the carton 36, it will normally be advisable to engage the lock assemblies 38, providing in effect two stable trays similar to the tray of FIG. 3.
As an additional retaining means between the overlying containers 10, it is proposed that a separate retainer 56 be provided. This retainer 56, a flat panel or sheet of the same shape-sustaining material as the container 10, includes an elongate body portion 58 with opposed ends and opposed longitudinal edges. An elongate slot 60 extends inward from one end thereof to form two wide furcations 62 having slightly rounded outer ends. The retainer 56 also preferably includes a coplanar upwardly directed combined handle and display portion 64 configured to display a restaurant logo or any other appropriate motif.
In use, and as will be appreciated from FIGS. 7-9, the retainer 56 is slid between the two shells of each of the engaged containers to receive the two outer edges 26 in a clamped relationship within the slot 60 with the furcations 62 respectively engaging between the adjacent inner walls 20 of the upper container and the adjacent inner walls 20 of the lower container. In this manner, a positive interlock is provided between the carton-forming containers of FIGS. 7 and 8 at an intermediate point between the latch engaged outer ends for a more secure carton. The engaged retainer 56, depending upon the weight of the contents of the closed carton 36, can actually comprise a handle means for handling or at least assisting in the handling of the carton. In such case, the design or display portion 64, depending again on the nature thereof, will provide a convenient grip means. It will also be recognized that the retainer 56 can be used and will stabilize the closed containers without the lock assemblies 38 being engaged.
From the foregoing, it will be recognized that the distinctive convertible container of the invention is basically arrived at by modifying a conventional clamshell carton in a simple although highly unique manner requiring only minor modification in the manufacturing procedure. No additional material expenses, the major cost of such containers, are involved.
In summary, the rear or inner walls of the two shells are formed perpendicular to the bases or base walls and incorporate, through an arrangement of cut lines and fold lines, a coplanar tongue and opening lock assembly which does not interfere with the opening and closing of the shells in the manner of a conventional clamshell carton. Upon engagement of the lock assembly, through simple finger pressure, the shells lock into abutting horizontally aligned relationship, forming a multi-compartment tray with upwardly opening chambers. Upon use with a duplicate inverted overlying tray, a multi-compartment closed carton is formed with closed chambers. As desired, the multi-compartment closed carton can be centrally reinforced by a retainer engaged between the overlying containers and presenting, preferably, a decorative or identifying motif. The retainer, depending upon the particular configuration thereof, can also be utilized as a means for facilitating gripping or handling of the multi-compartment carton.
While the container has been illustrated as comprising two generally rectangular shells, the inventive features can also be utilized with shells of other configurations. Any such variations will incorporate the hinge-joined inner walls which in the open position of the shells are in abutting parallel relationship and have the lock assembly of the invention incorporated therein.
The described embodiments are illustrative of the invention and are not to be considered as limitations on the scope of the invention. Rather, the invention is to be limited only by the scope of the claims following hereinafter.
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A convertible food container including two outwardly opening shells having inner walls interconnected along a common upper edge thereof for hinged movement of the shells between an open tray-forming position and a closed carton-forming position. The inner walls include integral tongue and recess lock components which are manually engageable to prevent movement of the inner walls, and hence the shells, relative to each other. A separate retainer enables a locking together of two overlying and facing containers in the open positions thereof.
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FIELD OF THE INVENTION
The present invention relates to a flame-guard preferably for electrical installations.
PRIOR ART
During the past few years, risks have increasingly been observed related to modern power- and telephone cable installations in the case of fire in plants where such installations are to be found. A fire can become of more extensive proportions by expanding through cable inlets, drums and shafts. Additionally, the cables' plastic insulation can produce gases, which through their toxic effect can injure or render people unconscious so that they are unable to protect themselves. The gases can also, through their corrosive effect, cause serious damage to buildings and installations, even if the fire is quickly stopped.
In order to overcome these problems, power and telephone cable manufacturers have begun to produce flame-protected cables. These cables possess considerably improved fire-inhibiting qualities, i.e., they have less tendency to burn than conventional cables. Nevertheless, under unfavorable circumstances these cables can also burn and have a fire-spreading effect. Such unfavorable circumstances exist, for example, if flame-protected cables are attached to an already existing installation, which comprises conventional, non-flame protected cables.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a flame-guard device with which cable installations comprising conventional installations can be protected. Another object is to provide an additive-guard for installations comprising exclusively flame protected cables or a mixture of flame protected and conventional cables. An additional object is to provide a flame-guard which in new installations makes it unneccessary to install a sprinkler system in the cable installations. Still another object is to provide a flame-guard device that does not disturb the running of cables at the increase of existing installations and that admits an adjustment of the flame-guard effect in dependence of the fire risk in various installations as much as in various sections of one and the same installation.
This is attained by the construction in which the flame-guard device comprises several capsules preferably arranged in a line and connected in a string, each one including a substance with flame-extinguishing qualities, the capsules being arranged to burst or open up when heated, thereby releasing a flame-extinguishing substance.
The flame-extinguishing substance, which at room temperature can be gaseous, fluid, or solid, consists of or produces through heating preferably halons, i.e., halogen substituted carbohydrates.
BRIEF DESCRIPTION OF THE DRAWINGS
Several embodiments of the invention will be described in connection with the accompanying drawing, in which
FIG. 1 is a cross-section through a capsule string in which capsules are connected by means of a hose, which surrounds the capsules,
FIG. 2 is a cross-section through a capsule string, in which the capsules are formed by contraction of a hose,
FIG. 3 is a cross-section through a capsule string, in which the capsules are connected by means of links and,
FIG. 4 is a cross-section through a capsule string, in which the capsules are formed around and connected by means of a cable running through the capsules.
DETAILED DESCRIPTION
FIG. 1 shows a capsule string, in which the capsules 1 are connected by means of a hose 3 which surrounds the capsules which contain fire-extinguishing material 2. The hose 3 is tightly wound around the capsules 1 so that these maintain their internal positions during handling of the capsule string. The capsules can be made of plastic, glass, or metallic material, shaped in such a manner that the material in the capsules either melts when exposed to the heat from a fire or burst due to the raised pressure in the capsules caused by the heat. The material 2 in the capsules is a flame-extinguishing substance consisting of a halon, or mixture of halons, or a halon producing substance.
FIG. 2 shows a capsule string, in which the capsules 1 are formed by contractions 4 in the hose, the contracted hose parts being provided with perforations 5. In addition to the fact that the perforations facilitate suspension or nailing of the capsule string, the string can also serve as a basic material for the production of capsule strings in accordance with FIG. 3. FIG. 3 shows capsules 1 connected by means of links 6 attached to end parts 7 of the capsules end which end parts are provided with holes. By differentiating the lengths of the links, one can, by using a single-size capsule, differentiate the amount of fire-extinguishing means per meter of string and thereby meet various requirements of flame-guard capacity.
FIG. 4 shows a capsule string in which the capsules 1 are formed around and connected to a cable 8, which can be made of plastic material. The plastic cable functions partly as a uniting element for the capsules and, partly as a seal-arrangement for the capsules.
Flame-guard devices in accordance with the invention can be very simply installed both in already existing installations and in new installations due to the fact that the capsule strings are handled and placed in the same manner as electric cables. If an amplified flame-guard is required, several capsule strings can be used and it is also possible to partially amplify the flame-guard in critical regions (e.g., at inlets) by winding the capsule string around a cable-bundle. In case of fire, there will, in many cases, only be a limited number of capsules consumed and only a small part of the flame-guard will then be necessary to be replaced. The part of the flame-guard which has not been in contact with the fire will be intact.
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A flame-guard device for electrical installations which consists of a cable-shaped string of capsules. The capsules contain a flame-extinguishing substance, which is released in case the capsules are heated.
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This application is a divisional of application Ser. No. 08/698,010 filed Aug. 13, 1996, now U.S. Pat. No. 5,767,129 allowed, which claims the benefit of Provisional Application Ser. No. 60/002,723 filed Aug. 24, 1995, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to novel substituted quinolines and isoquinolines thereof useful as pharmaceutical agents, to methods of their production, compositions which include these compounds and a pharmaceutically acceptable carrier, and to pharmaceutical methods of treatment. The novel compounds of the present invention are useful in the treatment of neurological disorders such as traumatic brain injury, cerebral ischemia, stroke, migraine, acute and chronic pain, epilepsy, Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, and depression. The compounds may also be useful for the treatment of nonneurological disorders such as asthma.
The entry of excessive amounts of calcium ion into neurons following an ischemic episode or other neuronal trauma has been well documented. Uncontrolled high concentrations of calcium in neurons initiates a cascade of biochemical events that disrupt normal cellular processes. Among these events are the activation of proteases and lipases, breakdown of neuronal membranes and the formation of free radicals which may ultimately lead to cell death. In particular, the selective N-type calcium channel blocker, SNX-111, has demonstrated activity in a number of models of ischemia and pain (Bowersox S. S., et al., Drug News and Perspective, 1994;7:261-268 and references cited therein).
Therefore, compounds which block N-type calcium channels may be useful in the treatment of neurological disorders such as traumatic brain injury, stroke, migraine, acute and chronic pain, epilepsy, Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, and depression.
SUMMARY OF THE INVENTION
The compounds of formula ##STR1## wherein R 1 to R 4 , A, X, m, and Y are as defined below. The compounds are useful in treating various neurological disorders and nonneurological disorders such as asthma.
Other aspects of the invention include pharmaceutical compositions containing one or more compounds of Formula I and pharmaceutical compositions containing a therapeutically effective amount of a compound of the invention.
Other aspects of the instant invention are methods of treating neurological disorders such as: traumatic brain injury, cerebral ischemia, acute and chronic pain, epilepsy, Parkinsonism, Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, and depression. Other disorders such as asthma are also treated.
DETAILED DESCRIPTION
The compounds of the instant invention are neuroprotective agents for use in cases where excess neuronal calcium accumulation contributes to cell death: stroke, cerebral ischemia resulting from cardiac arrest, head trauma, closed head injury, pain, amyotrophic lateral sclerosis, and also asthma.
The compounds of the instant invention are those of Formula I ##STR2## or a pharmaceutically acceptable salt thereof wherein: R 1 and R 2 are each independently OR 5 or CR 6 R 7 NR 8 R 9 and R 1 and R 2 cannot be the same;
R 1 and R 2 may be taken together with the ring to which they are attached to form a ring --CR 6 R 7 NR 8 CR 10 R 11 O-- or --OCR 10 R 11 NR 8 CR 6 R 7 --;
R 3 and R 4 are each independently hydrogen, alkyl, halogen, hydroxy, alkoxy, nitro, --NHCOalkyl, --NHCOaryl, or --NHCOalkylaryl;
A is a ring fused to the benzo ring at the positions a and b and formed by
a-NR--(CR 12 R 13 ) 3 -b,
a-CR 12 R 13 --NR--(CR 12 R 13 ) 2 -b,
a-(CR 12 R 13 ) 2 --NR--CR 12 R 13 -b, and
a-(CR 12 R 13 ) 3 --NR-b;
X is --(CH 2 ) n --or --C═O;
m is an integer of from 0 to 9;
Y is NR 14 R 15 , --CR 16 R 17 R 18 , ##STR3## aryl, or heteroaryl; R 5 -R 11 and R 19 are each independently hydrogen, alkyl, aryl, or arylalkyl; or
R 8 and R 9 are taken together with the nitrogen to which they are attached to form a ring of from 4 to 8 carbons, --CH 2 CH 2 OCH 2 CH 2 , --CH 2 CH 2 SCH 2 CH 2 --, or --CH 2 CH 2 R 19 CH 2 CH 2 --;
R is attached to the nitrogen in the A ring and is --X--(CH 2 ) m --Y;
each R 12 and R 13 are each independently hydrogen, alkyl, and aryl;
n is an integer of from 0 to 1;
R 14 and R 15 are each independently hydrogen, alkyl, aryl, arylalkyl, heteroaryl, or heteroarylalkyl;
R 16 and R 17 are each independently selected from hydrogen, alkyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl; and
R 18 is hydrogen, hydroxy, alkyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl.
Preferred compounds of the instant invention are those of Formula I wherein:
R 1 and R 2 are each independently --OR 5 or --CR 6 R 7 NR 8 R 9;
R 3 and R 4 are each independently hydrogen, halogen, nitro, or alkyl;
A is a-(CR 12 R 13 ) 2 --NR--CR 12 R 13 -b or a-(CR 12 R 13 ) 3 --NR-b;
X is --(CH 2 ) n or --C═O;
m is an integer of from 3 to 5;
Y is --CR 16 R 17 R 18 or ##STR4## R 5 -R 11 and R 19 are each independently hydrogen or alkyl; R 8 and R 9 are taken together with the nitrogen to which they are attached to form a ring of from 4 to 8 carbons, --CH 2 CH 2 OCH 2 CH 2 , --CH 2 CH 2 SCH 2 CH 2 --, or --CH 2 CH 2 R 19 CH 2 CH 2 --;
R is --X--(CH 2 ) m --Y;
each R 12 and R 13 are each independently hydrogen or alkyl;
n is an integer of from 0 to 1;
R 16 and R 17 are each independently hydrogen, or aryl; and
R 18 is hydrogen, hydroxy, or aryl.
Other preferred compounds are those of Formula I wherein:
R 1 and R 2 are taken together with the ring to which they are attached to form a ring --CR 6 R 7 NR 8 CR 10 R 11 O-- or --OCR 10 R 11 NR 8 CR 6 R 7 --;
R 3 and R 4 are each independently hydrogen, halogen, nitro, or alkyl;
A is a-(CR 12 R 13 ) 2 --NR--CR 12 R 13 -b or a-(CR 12 R 13 ) 3 --NR-b;
X is --(CH 2 ) n --or --C═O;
m is an integer of from 3 to 5;
Y is --CR 16 R 17 R 18 or ##STR5## R 5 -R 11 and R 19 are each independently hydrogen or alkyl; R is --X--(CH 2 ) m --Y;
each R 12 and R 13 are each independently hydrogen or alkyl;
n is an integer of from 0 to 1;
R 16 and R 17 are each independently hydrogen, or aryl; and
R 18 is hydrogen, hydroxy, or aryl.
The most preferred compounds of the invention are:
6-Azepan-1-ylmethyl-2-(4,4-diphenylbutyl)-1,2,3,4-tetrahydroisoquinolin-5-ol;
6-Cyclohexylaminomethyl-2-(4,4-diphenylbutyl)-1,2,3,4-tetrahydroisoquinolin-5-ol;
6-Azepan-1-ylmethyl-2- 4,4-bis-(4-fluorophenyl)-butyl!-1,2,3,4-tetrahydroisoquinolin-5-ol;
6-Azepan-1-ylmethyl-1-(4,4-diphenylbutyl)-1,2,3,4-tetrahydroquinolin-5-ol;
6-Azepan-1-ylmethyl-2-(5,5-diphenylpentyl)-1,2,3,4-tetrahydroisoquinolin-5-ol;
6-Azepan-1-ylmethyl-2-(6,6-diphenylhex-5-enyl)-1,2,3,4-tetrahydroisoquinolin-5-ol;
6-Azepan-1-ylmethyl-2-(4,4-diphenylpropyl-1,2,3,4-tetrahydroisoquinolin-5-ol;
6-Azepan-1-ylmethyl-2-(6,6-diphenylhexyl)-1,2,3,4-tetrahydroisoquinolin-5-ol;
6-Azepan-1-ylmethyl-2-(4-phenylbutyl)-1,2,3,4-tetrahydroisoquinolin-5-ol,
6-Azepan-1-ylmethyl-2- 4-(4-bromophenyl)butyl!-1,2,3,4-tetrahydroisoquinolin-5-ol;
6-Azepan-1-ylmethyl-2- 4-(4-fluorophenyl)butyl!-1,2,3,4-tetrahydroisoquinolin-5-ol;
2-Cyclohexyl-7-(4,4-diphenylbutyl)-2,3,5,6,7,8-hexahydro-1H-4-oxa-2,7-diazaphenanthrene; and
2-Cyclohexyl-7- 4,4-bis-(4-fluorophenyl)butyl!-2,3,5,6,7,8-hexahydro-1H-4-oxa-2,7-diazaphenanthrene.
In the compounds of the present invention, the term alkyl, in general and unless specifically limited, means a straight, branched, or cyclic alkyl group of from 1 to 8 carbon atoms including but not limited to methyl, ethyl, propyl, isopropyl, butyl, isobutyl, cyclopentyl, and cyclohexyl.
Alkoxy is as defined above in alkyl but attached via an oxygen.
Aryl refers to a mono- or bicyclic carbocyclic aromatic ring, for example, but not limited to, phenyl and naphthyl. The aryl group may be unsubstituted or substituted by one or more substituents selected from alkyl, halogen, OH, OCH 3 , NO 2 , and NHCOalkyl, preferably NHCOOCH 3 .
Heteroaryl is a mono- or polycyclic aromatic ring which contains a heteroatom, for example, but not limited to furanyl, thienyl, and isoquinolinyl.
Heteroarylalkyl is as above for alkyl and heteroaryl, for example, but not limited to 2-(2-thienyl)ethyl, 2-thienylmethyl, 2-pyridylmethyl, and the like.
Arylalkyl is defined as above in the terms alkyl and aryl as is, for example, and not limited to, benzyl, 2-phenylethyl, and 3-phenylpropyl is, for example, 4-phenylbutyl.
Carbocyclic ring is a 5- to 7-membered saturated or unsaturated ring and includes, for example, but not limited to, cyclopentane, cyclopentene, cyclohexane, cyclohexene, cycloheptane, cycloheptene, indane, and tetralin.
Halogen is fluorine, chlorine, bromine, or iodine;
fluorine, chlorine, and bromine are preferred.
The compounds of Formula I are capable of further forming both pharmaceutically acceptable acid addition and/or base salts. All of these forms are within the scope of the present invention.
Pharmaceutically acceptable acid addition salts of the compounds of Formula I include salts derived from nontoxic inorganic acids such as hydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydriodic, hydrofluoric, phosphorous, and the like, as well as the salts derived from nontoxic organic acids, such as aliphatic mono-, di-, and tricarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids, alkanedioic acids, aromatic acids, aliphatic and aromatic sulfonic acids, etc. Such salts thus include sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, nitrate, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, acetate, trifluoroacetate, propionate, caprylate, isobutyrate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, mandelate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, phthalate, benzenesulfonate, toluenesulfonate, phenylacetate, citrate, lactate, maleate, tartrate, methanesulfonate, and the like. Also contemplated are salts of amino acids such as arginate and the like and gluconate, galacturonate (see, for example, Berge S. M., et al., "Pharmaceutical Salts," J. of Pharma, Sci., 1977;66:1.
The acid addition salts of said basic compounds are prepared by contacting the free base form with a sufficient amount of the desired acid to produce the salt in the conventional manner. Preferably, a compound of Formula I can be converted to an acidic salt by treating with an aqueous solution of the desired acid, such that the resulting pH is less than four. The free base form may be regenerated by contacting the salt form with a base and isolating the free base in the conventional manner. The free base forms differ from their respective salt forms somewhat in certain physical properties such as solubility in polar solvents, but otherwise the salts are equivalent to their respective free base for purposes of the present invention.
Pharmaceutically acceptable base addition salts are formed with metals or amines, such as alkali and alkaline earth metals or organic amines. Examples of metals used as cations are sodium, potassium, magnesium, calcium, and the like. Examples of suitable amines are N,N'-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, dicyclohexylamine, ethylenediamine, N-methylglucamine, and procaine (see, for example, Berge S. M., et al., "Pharmaceutical Salts," J. of Pharma. Sci., 1977;66:1.
The base addition salts of said acidic compounds are prepared by contacting the free acid form with a sufficient amount of the desired base to produce the salt in the conventional manner. Preferably, a compound of Formula I can be converted to a base salt by treating with an aqueous solution of the desired base, such that the resulting pH is greater than nine. The free acid form may be regenerated by contacting the salt form with an acid and isolating the free acid in the conventional manner. The free acid forms differ from their respective salt forms somewhat in certain physical properties such as solubility in polar solvents, but otherwise the salts are equivalent to their respective free acid for purposes of the present invention.
Certain of the compounds of the present invention can exist in unsolvated forms as well as solvated forms, including hydrated forms. In general, the solvated forms, including hydrated forms, are equivalent to unsolvated forms and are intended to be encompassed within the scope of the present invention.
Certain of the compounds of the present invention possess one or more chiral centers and each center may exist in the R or S configuration. The present invention includes all enantiomeric and epimeric forms as well as the appropriate mixtures thereof.
BIOLOGICAL ACTIVITY
The compounds of the invention exhibit valuable biological properties because of their ability to potently block calcium flux through N-type voltage-gated calcium channels. To measure interaction at the N-type Ca 2+ channel and calcium flux inhibition, the effects of the calcium channel blockers were measured in the assays described below.
Chick Whole-Brain Synaptosomal 45 Calcium Flux Assay
Chicken brain synaptosomes contain voltage sensitive calcium channels which are inhibited by nanomolar concentrations of ω-contoxins and are therefore considered to be primarily N-type (Lundy P. M., Hamilton M. G., Frew R., Brain Res., 1994;643:204-210). 45 Ca flux into the synaptosomes may be induced by stimulation of the synaptosomal membrane with elevated potassium concentrations. A compound is assessed at various concentrations for its ability to inhibit this potassium stimulated calcium influx.
Methods
One- to five-week old chicks were killed by decapitation and whole brain was removed. The brainstem was discarded, and the remaining brain tissue was placed in ice-cold sucrose buffer (composition: 320 mM sucrose, 5.0 mM TRIS base, 0.1 mM EDTA, pH adjusted to 7.3 with HCl). The total wet weight of pooled brain tissue was determined, and the tissue was homogenized in 10 mL sucrose buffer per gram wet weight. A Potter S-type homogenizer (B. Braun Co.) with a glass tube and teflon pestle was used. Five strokes at 500 rpm were followed by four strokes at 800 rpm. The homogenate was poured into cold centrifuge tubes and centrifuged for 10 minutes at 3000 rpm (1,075 g) in a refrigerated 4° C. RC-5 centrifuge (Sorvall) using an SS-34 rotor. The supernatant was collected and centrifuged at 11,500 rpm (15,800 g) for 10 minutes The supernatant was discarded, and the pellet was resuspended in 1 mL sucrose buffer. Cold incubation buffer (composition: 1.2 MM MgCl 2 , 22 mM HEPES, 11 mM glucose, 3 mM KCl, 136 mM choline chloride, pH adjusted to 7.3 with TRIS base) was added slowly to the suspension for a total volume of 30-40 mL. This mixture was centrifuged at 7,000 rpm (5,856 g) for 5 minutes. The supernatant was discarded, and the pellet was resuspended in 5 mL of incubation buffer per gram of original wet weight of brain. This synaptosomal suspension was kept on ice until the start of the assay, at which time 25 μL of synaptosome suspension were added to each well of a 96-well filter plate (Millipore) which contained 75 μL incubation buffer with or without drug. Drugs were dissolved in DMSO or H 2 O, and the concentration of DMSO was less than or equal to 1%.
Synaptosomes were pre-incubated in the presence or absence of drug for 5 minutes at room temperature before the addition of radioactive calcium. Drugs were present throughout the assay. Two μCi/mL stocks of 45 CaCl 2 were prepared in basal buffer (composition: incubation buffer plus 1 mM CaCl 2 ) and in stimulation buffer (composition: 1.2 mM MgCl 2 , 22 mM HEPES, 11 mM glucose, 37 mM KCl, 102 mM choline chloride, 1 mM CaCl 2 , pH adjusted to 7.3 with TRIS base). One hundred microliter of radioactive basal or stimulation buffer were pipetted into a pre-incubated plate of synaptosomes, using a Quadra 96 pipetter (Tomtec). The final KCl concentration was 3 mM for the basal condition and 20 mM for the stimulated condition; the final CaCl 2 concentration was 0.5 mM with 1 μCi/mL of 45 CaCl 2 . The plate was filtered under vacuum after a 30-second incubation with radioactivity. The filters were washed twice with 200 μL of wash buffer (composition: 140 mM choline chloride, 3 mM EGTA, 22 mM HEPES, pH adjusted to 7.3 with TRIS base). Plates were allowed to dry completely. Scintillation fluid was added (20 μL/well), and the plates were counted in a Wallace Microbeta plate counter. Basal 45 CaCl 2 flux (3 mM KCl) was subtracted from stimulated 45 CaCl 2 flux (20 mM KCl ) in both control and drug-treated conditions, and data were expressed as percent inhibition of the adjusted control response. Values obtained in this way were plotted as a function of drug concentration and IC 50 values were calculated.
Measurement of N-type Ca2+ Channel Blocking Potencies of Compounds in IMR-32 Cells Using the Fluorescent Ca2+ Indicator Indo-1
IMR-32 cells are a human tumoral cell line of neural origin. The IMR-32 cell line has been shown to contain both N- and L-type voltage sensitive calcium channels. Calcium flux into these cells may be induced by stimulation with elevated potassium concentrations. The L-channel component of calcium flux may be blocked by adding 5 μM nitrendipine. The remaining component of calcium entry into the IMR-32 cells is due to calcium flux through N-type calcium channels. Intracellular calcium concentrations are measured using the fluorescent calcium indicator Indo-1. The effect of drug concentration on calcium uptake is studied.
Methods
The IMR-32 cell line was obtained from the American Type Culture Collection (Rockville, Md.).
Cells were grown in Eagle's Minimum Essential Medium with Earle's salts supplemented with 10% fetal bovine serum, 2 mM L-Gln and antibiotic/antimicotic mixture (Gibco). At approximately 80% confluency, differentiation was induced by the addition of 1 mM dibutyryl cAMP and 2.5 μM bromodeoxyuridine to the medium. After 7 to 13 days of differentiation, cells were detached using 0.5 mM EDTA and loaded with five 5 μM Indo-1 acetoxymethyl ester (Molecular Probes, Eugene, OR) at 30° C. for 45 minutes. Loaded cells were washed twice, resuspended (˜10 7 cells/mL) in assay buffer (10 MM HEPES/Tris pH 7.4 in Hank's Balanced Salt Solution without bicarbonate or phenol red containing 0.5% bovine serum albumin) and kept on ice until use. Fluorescence measurements were carried out in a Photon Technology International (PTI, South Brunswick, N.J.) Model RF-F3004 spectrofluorometer with dual emission monochromators using excitation at 350 nm and emission at 400 and 490 nm. The instrument was equipped with a thermostatted cuvette holder with stirring capabilities as well as with a computer-controlled pump which allowed for reagent addition during measurement. Instrument control and data collection was done by PTI's OSCAR software running on an IBM compatible computer. Different concentrations of the test compounds (60 μL in dimethyl sulfoxide) were added to 5.94 mL of assay buffer containing approximately 3×10 6 loaded cells, and 5 μM Nitrendipine (in 30 μL EtOH) to block L-type Ca 2+ channels. Samples were incubated for 10 minutes at 30° C. and then aliquoted into three 10×10 mm disposable acrylic cuvettes. Emission signals at 400 and 490 nm were acquired from each cuvette at 30° C. for 50 seconds. At 20 seconds after the start of reading, cells were depolarized by the addition of 160 μL of stimulation solution (1M KCl, 68 mM CaCl 2 ) to the cuvette via the computer-controlled pump. Ratio of dual emission signals (400 nm/490 nm), which is proportional to intracellular Ca 2+ concentration, was plotted against time, and the difference between maximal response after stimulation and basal value (before stimulation) was determined. Values obtained in this way were plotted as a function of drug concentration. IC 50 values of test compounds were calculated by fitting a four-parameter logistic function to the data using the least squares method.
TABLE 1______________________________________Inhibition of Calcium Flux in ChickenSynaptosomes and IMR-32 Cells Inhibition of .sup.45 Ca.sup.+2 Inhibition of Ca.sup.+2 Influx in Chick Influx in Synaptosomes IMR-32 CellsExample IC.sub.50 μM IC.sub.50 μM______________________________________6 0.49 0.827 3.7 1.08 3.4 1.111 Not Tested 1.3______________________________________
Table 1 above summarizes the findings of the two assays. Based on these findings, the compounds of the invention are believed to be useful in treating calcium channel-related diseases.
The following nonlimiting examples illustrate the present invention.
EXAMPLE 1
1,1-Diphenyl-1,4-butanediol
4-Butyrolactone (11.93 mL, 0.155 mol) was dissolved in anhydrous THF and cooled to 0° C. Phenylmagnesium bromide (3 M in ether, 112 mL) was added dropwise over 30 minutes to the reaction under N 2 . After the addition, the reaction was warmed to room temperature overnight. Additional phenylmagnesium bromide (3 M in ether, 103 mL) was added, and the reaction stirred at room temperature overnight. The reaction was quenched with saturated NH 4 Cl (150 mL). Ether (200 mL) and 10% HCl (100 mL) were added. The organic layer was separated and washed with 10% HCl (100 mL), brine (100 mL), and then dried over MgSO 4 . The solution was filtered, concentrated, and the crude material chromatographed on silica gel eluting with 50% EtOAc/Hexanes to give 26.94 g (72%) of desired product as an off-white solid.
1 H NMR (400 MHz, CDCl 3 ): δ 7.45-7.15 (m, 10H), 3.65 (t, 2H, J=5.9 Hz), 2.42 (m, 4H), 1.57 (m, 2H).
EXAMPLE 2
4,4-Diphenyl-1-butanol
1,1-Diphenyl-1,4-butanediol (26.62 g, 0.110 mol) was dissolved in MeOH and shaken with 20% Pd/C (1.50 g) on a Parr apparatus under an H 2 atmosphere (50 psi) for 17 hours. The MeOH was removed in vacuo, and the residue chromatographed on silica gel eluting with 35% EtOAc/Hexanes gave 22.53 g (91%) of desired product.
1 H NMR (400 MHz, CDCl 3 )z 6 7.3-7.1 (m, 10H), 3.90 (t, 1H, J=7.9 Hz), 3.63 (t, 2H, J=6.5 Hz), 2.1 (q, 2H, J=7.9 Hz), 1.5 (m, 2H).
EXAMPLE 3
1-Bromo-4,4-diphenylbutane
4,4-Diphenyl-1-butanol (22.41 g, 0.099 mol) was dissolved in ether (250 mL). CBr 4 (41.07 g, 0.123 mol) was added and the reaction cooled to 0° C. Triphenylphosphine (38.96 g, 0.148 mol) in ether (400 mL) was added dropwise to the reaction. The reaction was then allowed to warm to room temperature overnight. DMSO (3.51 mL) was added, and the reaction allowed to stir for 8 hours. The white precipitate was filtered and washed with ether (100 mL). The ether was removed in vacuo, and the residue washed with hexanes and filter. The hexanes were removed in vacuo, and the residue chromatographed on silica gel eluting with hexanes to give 20.72 g (72%) of desired product as an oil.
1 H NMR (200 MHz, CDCl 3 ): δ 7.4-7.1 (m, 10H), 3.92 (t, 1H, J=7.5 Hz), 3.41 (t, 2H, J=6.5 Hz), 2.35-2.1 (m, 2H), 1.95-1.75 (m, 2H).
EXAMPLE 4
2-(4,4-Diphenylbutyl)-5-hydroxyisoguinolinium bromide
A mixture of 5-hydroxyisoquinoline (2.17 g, 14.95 mmol) and 1-bromo-4,4-diphenylbutane (4.79 g, 16.56 mmol) in 75 mL of anhydrous DMF was stirred at 80° C. for 16 hours. The reaction mixture was cooled to room temperature. Ethyl acetate (200 mL) was added to precipitate product. The solid was collected by filtration and washed with ethyl acetate (1×70 mL). The solid was air-dried to give 4.52 g of product as an off-white solid.
1 H NMR (300 MHz, DMSO-d 6 ): δ 11.48 (s, 1H), 9.99 (s, 1H), 8.59 (ABq, 2H, J AB =6.85 Hz, υ AB =35.99 Hz), 7,88 (d, 2H, J=4.58 Hz), 7.54 (m, 1H), 7.28 (m, 8H), 7.17 (m, 2H), 4.73 (t, 2H, J=6.87 Hz), 3.98 (t, 1H, J=7.75 Hz), 2.11-2.06 (m, 2H), 1.95-1.90 (m, 2H).
EXAMPLE 5
2-(4,4-Diphenylbutyl)-1,2,3,4-tetrahydroisoguinolin-5-ol
To a solution of 2-(4,4-diphenylbutyl)-5-hydroxyisoquinolinium bromide (2.29 g, 5.27 mmol) in 100 mL of methanol was added 20% Pd/C catalyst (0.7 g). The reaction mixture was shaken under 50 psi of hydrogen at room temperature for 18 hours. The catalyst was then removed by filtration through a pad of Celite. The residue was washed with methanol, and the filtrate was concentrated under vacuum. The white solid obtained was neutralized with saturated sodium bicarbonate solution. The mixture was extracted with ethyl acetate (2×200 mL). The organic extracts were collected and dried with magnesium sulphate, filtered and concentrated to give 1.9 g of crude product as a yellow oil.
1 H NMR (300 MHz, CDCl 3 ): δ 7.31-7.15 (m, 10H), 6.93 (t, 1H, J=7.87 Hz), 6.56 (d, 1H, J=7.63 Hz), 6.46 (d, 1H, J=7.63 Hz), 3.93 (t, 1H, J=7.93 Hz), 3.56 (s, 2H), 2.54 (m, 2H), 2.11 (m, 2H), 1.61 (m, 2H)
EXAMPLE 6
6-Azepan-1-ylmethyl-2-(4,4-diphenylbutyl)-1,2,3,4-tetrahydroisoquinolin-5-o
To a solution of 2-(4,4-diphenylbutyl)-1,2,3,4-tetrahydro-isoquinolin-5-ol (1.9 g, 5.32 mmol) in 5 mL of absolute ethanol was added hexamethyleneimine (0.6 mL, 5.32 mmol) followed by a 37% formaldehyde solution (0.4 mL, 5.34 mmol). The reaction mixture was stirred at room temperature for 4 days. Ethyl acetate (60 mL) and half saturated sodium chloride solution (60 mL) were added. The organic layer was collected, and the aqueous layer was extracted with ethyl acetate (2×30 mL). The combined organic extracts was dried with magnesium sulphate, filtered, and concentrated to give a brown oil The oil was chromatographed on silica gel eluted with 10% methanol in ethyl acetate to give 1.9 g of a yellow oil. The oil was dissolved in 30 mL of methanol. A solution of hydrogen chloride in ether (1.0 M, 9 mL) was added at room temperature to form a brown precipitate. The solid was collected by filtration and washed with 30% methanol in ether solution (2×60 mL) and then with ether (3×60 mL). The solid was air-dried overnight to give 1.79 g of a white solid as the dihydrochloride salt, mp=255-256° C.
Analysis Calculated for C 32 H 42 Cl 2 N 2 O: C, 70.97; H, 7.82; N, 5.17. Found: C, 70.45; H, 7.67, N, 5.09.
EXAMPLE 7
6-Cyclohexylaminomethyl-2-(4,4-diphenylbutyl)-1,2,3,4-tetrahydroisoguinolin-5-ol
2-(4,4-Diphenylbutyl)-1,2,3,4-tetrahydro-isoquinolin-5-ol (2.44 g, 6.83 mmol) was dissolved in EtOH (70 mL). Formaldehyde (37%, 0.536 mL, 7.17 mmol) and cyclohexylamine (0.820 mL, 7.17 mmol) were added, and the reaction heated to 50° C. for 10 days. The solvent was removed and the crude reaction chromatographed on silica gel eluting with EtOAc. Isolate 2.44 g (76 %) of product as an oil. The oil (0.61 g, 1.30 mmol) was then dissolved in Et 2 O (10 mL). Oxalic acid (0.33 g, 2.62 mmol) in EtOH (1 mL) was added to the ether solution, and the reaction stirred at room temperature for 18 hours. The light tan precipitate was filtered and washed with EtOAc and dried in vacuo over P 2 O 5 to give 0.61 g (73%) of the oxalic acid salt, mp=127-144° C.
Analysis calculated for C 32 H 40 N 2 O.1.84 C 2 H 2 O 4 : C, 67.56; H, 6.94; N, 4.42. Found: C, 67.56; H, 6.90; N, 4.26.
EXAMPLE 8
2-Cyclohexyl-7-(4,4-diphenylbutyl)-2,3,5,6,7,8-hexahydro-1H-4-oxa-2,7-diazaphenanthrene
6-Cyclohexylaminomethyl-2-(4,4-diphenylbutyl)-1,2,3,4-tetrahydro-isoquinolin-5-ol (1.84 g, 3.93 mmol) was dissolved in MeOH (35 mL). Formaldehyde (37%, 0.60 mL, 8.0 mmol) was added, and the reaction stirred at room temperature for 96 hours. The MeOH was removed in vacuo, and the crude material filtered through a plug of silica gel eluting with EtOAc to give 1.68 g (89%) of product as an oil. MS(CI with 1% NH 3 in CH 4 ) m/e 481 (M + +1). The oil (1.68 g, 3.49 mmol) was then dissolved in ether (25 mL). Oxalic acid (0.88 g, 6.99 mmol) in EtOH (2 mL) was added to the ether solution, and more ether (10 mL) was added to break up solid precipitate. The reaction was stirred for 2 hours, the solid filtered and washed with EtOAc. Drying in vacuo yielded 1.83 g (79%) of the oxalic acid salt, mp=102-117° C.
Analysis calculated for C 33 H 40 N 2 O.2.19 C 2 H 2 O 4 : C, 66.23; H, 6.60; N, 4.13. Found: C, 66.24; H, 6.39; N, 3.89.
EXAMPLE 9
2- 4,4-Bis-(4-fluorophenyl)butyl!-5-hydroxyiso quinolinium bromide
A mixture of 5-hydroxyisoquinoline (4.56 g, 31.41 mmol) and 4,4-bis(4-fluorophenyl)butyl bromide (11.40 g, 35.06 mmol. Prepared according to the procedure of Miroslav Rajsner, et al., Czech. Collect. Czech. Chem. Commun., 1978;43:1760) in 100 mL of anhydrous DMF was stirred at 80° C. overnight. The reaction mixture was cooled to 0° C. Ethyl acetate (400 mL) was added to precipitate product. The solid was collected by filtration and washed with ethyl acetate (2×100 mL). The solid was air-dried to give 10.74 g of product as an off-white solid.
1 H NMR (400 MHz, DMSO-d 6 ): δ 11.42 (br. s, 1H), 9.92 (s, 1H), 8.58 (d, 1H, J=7.08 Hz), 8.46 (d, 1H, J=6.84 Hz), 7.82 (d, 2H, J=4.64 Hz), 7.47 (t, 1H, J=4.40 Hz), 7.25 (m, 4H), 7.04 (m, 4H), 4.66 (t, 2H, J=7.08 Hz), 3.98 (m, 1H), 1.99 (m, 2H), 1.84 (m, 2H).
EXAMPLE 10
2- 4,4-Bis-(4-fluorophenyl)butyl!-1,2,3,4-tetrahydroisoquinolin-5-ol
To a solution of 2- 4,4-bis-(4-fluorophenyl)-butyl!-5-hydroxyisoquinolinium bromide (4.99 g, 10.61 mmol) in 165 mL of methanol at 0° C. was added sodium borohydride (1.54 g, 40.71 mmol). The reaction mixture was stirred at 0° C. for 15 minutes, then at room temperature for 15 minutes. The mixture was concentrated on a rotavap. The residue was dissolved in ethyl acetate (200 mL) and washed with saturated ammonium chloride solution (150 mL). The organic layer was collected, and the aqueous layer was extracted with ethyl acetate (1×100 mL). The combined organic layers was dried with magnesium sulphate, filtqred, and concentrated to give 1.9 g of crude product as a brown oil. The oil was chromatographed on silica gel eluted with 50% ethyl acetate in hexanes to give 2.54 g of product.
1 H NMR (400 MHz, CDCl 3 ): δ 7.14-7.10 (m, 4H), 6.97-6.89 (m, 5H), 6.56 (m, 2H), 3.85 (t, 1H, J=7.81 Hz), 3.48 (s, 2H), 2.66 (m, 4H), 2.47 (m, 2H), 2.02 (m, 2H), 1.50 (m, 2H).
EXAMPLE 11
6-Azepan-1-ylmethyl-2- 4,4-bis-(4-fluorophenyl)-butyl!-1,2,3,4-tetrahydroisoquinolin-5-ol
To a solution of 2- 4,4-bis-(4-fluorophenyl)-butyl!-1,2,3,4-tetrahydroisoquinolin-5-ol (2.54 g, 6.46 mmol) in 40 mL of tetrahydrofuran was added hexamethyleneimine (1.2 mL, 10.65 mmol) followed by a 37% formaldehyde solution (0.8 mL, 10.67 mmol). The reaction mixture was stirred at room temperature overnight. Hexamethyleneimine (0.6 mL, 5.32 mmol) and a 37% formaldehyde solution (0.4 mL, 5.34 mmol) was added, and the reaction mixture was stirred at room temperature for 5 hours. After the 5-hour period, another portion of hexamethyleneimine (0.6 mL, 5.32 mmol) and a 37% formaldehyde solution (0.4 mL, 5.34 mmol) was added. The reaction mixture was stirred at room temperature overnight. The mixture was concentrated on a rotavap. The brown oil was washed with brine solution. The mixture was extracted with ethyl acetate (2×100 mL). The organic layer was collected and dried with magnesium sulphate, filtered, and concentrated. The oil was chromatographed on silica gel eluted first with 75% ethyl acetate in hexanes to remove the phenol starting material then with pure ethyl acetate to give 1.84 g of the product as an off-white solid. The solid was dissolved in 40 mL of methanol and 50 mL ethyl ether. A solution of hydrogen chloride in ether (1.0 M, 7.5 mL) was added at room temperature to precipitate out the product as its hydrochloride salt. The solid was collected by filtration and washed with ether (3×50 mL). The solid was air-dried overnight to give 1.95 g of a white solid as the dihydrochloride salt, mp=238-239° C. (dec).
Analysis calculated for C 32 H 38 F 2 N 2 O.2HCl: C, 66.54; H, 6.98; N, 4.85. Found: C, 66.32, H, 6.97, N, 4.78.
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The present invention relates to novel substituted quinolines and isoquinolines and derivatives thereof useful in the treatment of neurological disorders. Methods of preparing the compounds, intermediates useful in the preparation and pharmaceutical compositions containing the compounds are also included. The compounds are useful in treating pain, cerebral ischemia, and other cerebrovascular disorders.
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[0001] This application claims the benefit of U.S. provisional patent application No. 61/247,742, filed on Oct. 1, 2009. The contents of this provisional application are fully incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of middle ear implants and improvements in obtaining sound quality for middle ear implant patients. The invention more particularly relates to improved apparatus and methods used in, or with, magnetic middle ear hearing systems. The present invention most particularly relates to improved magnetic implants and to improved attachment devices and methods for mounting a magnet in the middle ear of a patient.
BACKGROUND OF THE PRESENT INVENTION
[0003] There are many different reasons why some people have hearing impairment. In general, however, sound entering the outer ear canal does not get transmitted to the inner ear and/or transmitted to the auditory nerve. In some instances, this can be solved by amplifying the sound with a hearing aid put in the outer ear canal. In other cases, a cochlear implant device that electrically stimulates the auditory nerve directly needs to be implanted in the cochlea of the inner ear. In still other situations, a middle ear device that creates mechanical vibrations is needed. The present invention pertains to such middle ear devices, and specifically magnetic middle ear devices.
[0004] A person's normal middle ear includes a chain of small bones, or ossicles. The malleus, the incus, and the stapes form this chain; and, when functioning normally, these ossicles transmit mechanical vibrations from the eardrum, or tympanic membrane, at the end of the outer ear canal to the oval window into the inner ear. When something is defective in this ossicular chain, however, such transmission does not occur sufficiently to stimulate the cochlea and/or the auditory nerve. Alternatively, if transmission through the ossicular chain is normal, but the inner ear hair cells are damaged or absent, the auditory nerve may receive less stimulation. Either way, greater amplitude of ossicular movement will help correct the hearing deficit.
[0005] One general solution to hearing problems caused by middle ear deficiencies is to implant a magnet in the middle ear and to cause the magnet to vibrate in response to environmental sounds. The magnet is connected, for example, such that it provides mechanical vibrations to the oval window, either through an adequately functioning portion of the middle ear's ossicular chain to which the magnet is attached, or through an implanted prosthesis carrying the magnet and communicating with the oval window.
[0006] A number of middle ear magnet attachment devices have been proposed. Some clip to an ossicle, or part of one; others abut ossicular surfaces; others have wires or rods attached to transducers; others have probes connected to transducers wherein the probes must fit into holes placed in the ossicles; others have closed loops that slide over a portion of the ossicular chain; and others use surface tension forces that seek to hold an implant onto the living epithelium of the round window of the inner ear.
[0007] Each of these proposed methods have shortcomings. Regardless of the particular implant or mounting technique used for a middle ear magnet, problems can arise with regard to alignment of the magnetic with the magnetic field.
[0008] When a coil of wire is energized by the flow of electricity, it becomes an “electromagnet” whose magnetic strength and polarity are based on the direction and strength of the electric current energizing it. If a permanent magnet is placed near this electromagnetic coil, the magnet will be attracted to or repelled from the coil. The induced vibration of the magnet is what acts to ultimately stimulate the oval window. With an extra-coil electromagnetic (ECE) transducer, the coil is placed in the ear canal, and the magnet is located at some distance away from the coil along the coil's axis. However, the nature of the ECE transducer is such that the power delivered by the coil to the magnet is sensitive to the coil-magnet alignment.
[0009] If the implanted magnet is not optimally aligned with the external coil from which the electromagnetic signal propagates, the implanted magnet might not respond adequately. By “optimally aligned” is meant that the attached magnet is axially aligned with the electromagnetic coil, or the extra-coil electromagnetic transducer (ECE), and generally aligned along the axis of the ear canal. This is very important as the position and angle of the ossicular chain varies in the anatomy from patient to patient. For example, the angle of the stapes to the external auditory canal can vary from patient to patient. Thus, a magnet that has been rigidly clamped to the incudostapedial joint of the ossicular chain will not necessarily be at the optimum alignment to the ear canal and can be misaligned.
[0010] A disadvantage of clip mechanisms known in the prior art is difficulty in aligning the magnet with different patient anatomies. It is desirable to have the magnet aligned axially to the ear canal so that ECE transducer in the ear canal is aligned axially with it. If the magnet is at an angle to the coil, energy transfer efficiency will be lost. In many patients, the stapes is not aligned axially to the ear canal. Therefore, if a magnet is clipped onto the stapes, which is itself at an angle to the ear canal, then the coil and magnet will not be properly aligned, and energy transfer to the magnet and, consequently, the ossicular chain and cochlea, will be diminished
[0011] Clamping or clipping onto living bone (ossicles) can also compromise oxygen and nutrient delivery, thus resulting in necrosis of the ossicles. In order to prevent this, U.S. Pat. No. 6,712,754 (Dormer) proposed the use of circular loops or rings which were slightly larger than the ossicle. Circular wire rings rely upon tissue formation to secure the implant to the ossicular chain. However, this can result in a loose fit, and if the magnet is allowed to vibrate loosely about the ossicle, this will result in loss of performance and a “rattling” effect for the patient. Even when tissue does form, tissue itself is relatively soft and elastic. Thus, it does not transmit vibrations as well as a rigid connection.
[0012] Another disadvantage of this type of mechanism is that the tissue formation required to create contact between the coils and ossicles takes several weeks to form after surgery. As a result, the orientation of the magnet may move during the healing time, and can become permanently misaligned once the tissue forms. In addition, the circular ring method, known in the prior art, requires disconnecting the incus of the middle ear from the stapes of the middle ear and sliding the loop onto the stapes. It is not desirable to do this as the ossicular chain is quite delicate and a mishap could result in additional or total hearing loss.
[0013] Changes in position of implanted magnets can occur from a variety of causes. For example, implant surgeons have different techniques and skills, and thus magnet location may vary because of differences in surgeons. As another example, one particular type of attachment device might orient its magnet differently from how another particular type of attachment device orients its magnet even though the magnets are located at the same ossicular position in the respective patients.
[0014] As a further example, anatomical differences between patients can cause similarly located magnets to be oriented differently relative to an external device (such as an external electromagnetic signal generating unit in the person's outer ear canal). As stated above, changes in orientation can also occur during the healing process following the implantation surgery. For example, known support structures, such as GELFOAM™, which is used to hold a magnet in position during the healing process, may become dislodged and allow the magnet to move; tissue growth may occur non-uniformly between the magnet and the ossicle, thus altering the initial position of the magnet; and forceful physical activities may move the magnet out of position prior to tissue fully encapsulating it.
[0015] Thus, there is the need for an attachment device and method, as well as an overall implant, which overcomes these shortcomings in the prior art, and which enables an implant to be placed, and secured, reliably, and in optimal alignment with the external coil.
SUMMARY OF THE INVENTION
[0016] The present invention overcomes the above-noted and other shortcomings of the prior art by providing a novel and improved implant and attachment device and method for mounting a magnet in a middle ear of a patient in optimal alignment with an electromagnetic coil or extra coil electromagnetic (ECE) transducer.
[0017] The present invention allows for biologically compatible, non-necrotizing, light weight, anatomical positioning of a magnetic implant onto the ossicular chain of a patient. It provides a specific orientation at the location of implantation which preferably does not change or move once implanted. The present invention allows the magnet implant to be aligned precisely despite changes in middle ear anatomy from one patient to another.
[0018] In addition, it provides for a rigid connection between the magnet and ossicles, thereby providing maximum transmission of vibrations to the ossicle, yet does not apply a force to the ossicle to create the rigid connection. Thus, the connection mechanism does not compromise blood supply or nutrient flow. The ossicular chain does not need to be separated in implanting the device. Such mounting provides for lifetime implantation on an intact ossicular chain.
[0019] The present invention also provides a method of mounting a magnetic implant in a middle ear. This method comprises positioning the magnet in the optimal alignment, and then using biocompatible cement to adhere the magnet to the ossicle. Preferably, the cement forms a cast-like structure completely around the tissue of the ossicle and adheres to the magnet. Alternately, the cement may bond directly to the ossicle itself if tissue is removed.
[0020] Preferred biocompatible cements include hydroxylapatite and glass ionomer cements, although other biocompatible cements or glues may also be used.
[0021] In another embodiment, a wire-form may be attached to the magnet. The wire-form is placed loosely around the ossicle and the magnet is positioned in the optimal alignment with the outer ear canal and exterior coil. Biocompatible cement is then used to adhere the magnet to the ossicle with the wire-form as a scaffold structure within the cement.
[0022] The wire-form may consist of a single wire or band, or two or more wires or bands. In a preferred embodiment, it consists of a wire-form attached to the magnetic implant with two wire-formed structures projecting from the implant. Each of these wire-form structures fit on opposite sides of an ossicle. They may be circular, oval, rectangular or of other geometric configurations. The wire-form serves as the scaffold structure for the cement to bond totally around the ossicle. The wire-form should preferably have a configuration that facilitates wicking of cement into the wire-form structure
[0023] The wire-form structure is not limited to being made from wire, and may be made from bands, for example, and may be in any configuration that fits around the ossicle, provided that it does not apply a force upon the ossicle to hold the device in place and such that the device is freely moved about the ossicle to allow for proper alignment of the magnet with the ear canal prior to the application of the cement.
[0024] The wire-form material should be made from a metal which is biocompatible, such as titanium, gold, stainless steel or other known biocompatible metals. When using a wire-form, it is preferable to use a wire-form made from biocompatible metal alloys, such as such as NITINOL™, with shape memory properties. When the wire-form is made from a shape memory material, the surgeon may open the ring to allow for placing the wire-form around an ossicle, and then apply heat to return the wire-form to its original shape.
[0025] The primary advantages of a shape memory material include that it can be formed into a desired shape without permanently deforming the material. The material can be returned to its original shape by applying heat and without the use of mechanical force (e.g. crimping tool). If the material is inadvertently deformed into an undesired shape, it can be returned to its original shape by applying heat. The transition temperature set point can be established at a desired value by modifying the alloy composition and/or by heat treatment.
[0026] Above this transition set point the material has superelastic properties, and below this point the material has more plastic properties. “Superelastic”, or “very springy” properties may have advantages in certain applications where it is desirable for the material to return to the original shape after experiencing force; plastic properties may have advantages in certain applications where it is desirable for the material to conform to a new shape after experiencing force.
[0027] Other potential benefits of using shape memory material are that it reduces the number or types of tools required to conduct a surgical procedure. It provides for shorter duration of the procedure, and allows for access into smaller or obscured areas.
[0028] Shape memory material can be produced from a variety of alloys (e.g. copper-zinc-aluminum-nickel, copper-aluminum-nickel, and nickel-titanium, others). The material is formed, or worked, into the desired final shape. While remaining fixed in this desired final shape, the component is heat treated to form the crystalline structure unique to the desired final shape. This establishes the “shape memory”. After this point, the component is then capable of being deformed, or strained, into an intermediate shape, and can be reformed to the desired final shape by heating above its transition temperature. While there is a limit to the amount of deformation that can occur while still maintaining those original shape memory properties, the component can be deformed into an intermediate shape (e.g. open loop) and will maintain this shape indefinitely until heat or force is applied. This is known as a one-way shape memory application.
[0029] In a two-way shape memory application, the intermediate shape discussed above can be set, and through a series of heat treatment and shape setting steps, the material can achieve two memory states. While the material is above the transition temperature, it assumes the desired final shape, while below the transition temperature, the material assumes the intermediate shape. For instance, if the transition temperature was just below body temperature, then the intermediate shape could be below body temperature (during installation), and the desired final shape could be at body temperature (after installation). This would provide the advantage of allowing the body's natural temperature to form to the final, desired configuration and not requiring the use an external device to heat the wire-form.
[0030] Other methods of heating a shape memory material in middle ear procedures may include electro-cautery, laser or other heating means capable of temporarily heating the shape memory material above the transition temperature.
[0031] In yet another embodiment of the present invention a bi-metal material may be used. A bi-metal material is two or more layers of dissimilar metal materials laminated to each other. These two materials have dissimilar coefficients of thermal expansion, which converts a temperature change into mechanical displacement.
[0032] To use a bi-metal, the bi-metal wire-form or attachment is temporarily changed to an intermediate shape by heating it, thus causing the ring to expand and allowing the implant to be placed around the ossicle. When it cools, it returns to the original shape. Methods of heating a bi-metal material in middle ear procedures may include electro-cautery, laser or other heating means capable of temporarily heating the bi-metal material above the transition temperature.
[0033] It can be seen from the foregoing that many problems still exist in the art of middle ear implants, and those skilled in the art continue to search for a satisfactory solution to the problem of aligning a magnet with an electromagnetic coil, or an extra coil electromagnetic transducer.
[0034] Therefore, it is an object of the present invention to provide a novel and improved implant and attachment device and method for mounting a magnet in a middle ear of a patient. Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art when the following description of the preferred embodiments is read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is an environmental view showing a partial cross-sectional view of the inner and outer ear with pertinent portions shown in cross-section. A construction embodying the present invention is also shown.
[0036] FIG. 2 is an enlarged, perspective view of a portion of the construction shown in FIG. 1 .
[0037] FIG. 3 shows the construction of FIG. 2 attached to a portion of the ossicular chain with biocompatible cement.
[0038] FIG. 4 shows a modification of the construction shown in FIG. 2 .
[0039] FIG. 5 illustrates a further modification of the construction shown in FIG. 2 .
[0040] FIG. 6 illustrates a further modification of the construction shown in FIG. 2 .
[0041] FIG. 7 illustrates a still further modification of the construction shown in FIG. 2 .
[0042] FIG. 8 illustrates a still further modification of the construction shown in FIG. 2 .
[0043] FIG. 9 is a view similar in part to FIG. 2 with bio-compatible cement used to attach the construction to a portion of the ossicular chain in place of a wire form.
[0044] FIG. 10 shows the construction of FIG. 2 in more detail.
[0045] FIG. 11 is an environmental view illustrating an anatomical configuration of the ossicular chain relative to the outer ear canal, with pertinent portions shown in cross-section
[0046] FIG. 12 is an environmental view illustrating the misalignment of a clamped magnet housing on an angled ossicle, with pertinent portions shown in cross-section
[0047] FIG. 13 is an environmental view illustrating a properly aligned magnet housing the method of the present invention on an angled ossicle; with pertinent portions shown in cross-section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] A human ear is represented in FIG. 1 . It includes an outer ear 2 , a middle ear 4 , and an inner ear 6 . Pertinent to the description of the present invention is an outer ear canal 8 which is normally closed at its inner end by tympanic membrane, or eardrum, 10 . Also pertinent is an ossicular chain, which, if intact, extends from tympanic membrane 10 to oval window 12 defining an entrance to the inner ear 6 . The intact ossicular chain extends through the middle ear 4 and includes a malleus 14 , an incus 16 , and a stapes 18 . A properly functioning ossicular chain transmits vibrations from the tympanic membrane 10 in series through the malleus 14 , the incus 16 and the stapes 18 to the oval window 12 . Vibrations at the oval window stimulate the inner ear 6 , whereby the person perceives the sound received in the outer ear 2 .
[0049] An object of the present invention is to provide the vibratory stimulation to the inner ear 6 when there otherwise is inadequate vibration transmission in the person's middle ear 4 . To accomplish this, the present invention provides an implant, generally designated by the numeral 20 , for a middle ear of a patient. Also provided is an attachment device 26 for attaching the implant 20 , as described herein below in optimal alignment with an electromagnetic coil or extra coil electromagnetic (ECE) transducer 11 .
[0050] Referring to FIGS. 1 , 2 , 10 , 12 , and 13 the implant 20 comprises a housing or canister 22 , and a magnet 80 disposed in the housing 22 . In a preferred embodiment, the housing 22 is a commercially pure titanium canister, hermetically sealed and containing a rare earth permanent magnet (e.g., Nd.sub.2 Fe.sub.14 B) as the magnet 80 .
[0051] The lid of the housing 22 is laser welded to the main body of the housing in an inert gas environment, excluding oxygen from the canister 22 . Variations in the housing shape and size may be made to fit the implant so as to accommodate the anatomical structures of the ossicles. Such variations in the housing may fit intraossicular, interossicular or paraossicular ossicles. Variations may include those other than the preferred embodiment of a right cylinder.
[0052] As illustrated in FIGS. 1 , 12 , and 13 , the attachment device 26 connects the implant 20 , to at least a partial middle ear ossicle. “At least a partial middle ear ossicle” means that the attachment device 26 mounts on a functional part of an ossicular chain, which could be less than the entire ossicular chain or less than a single ossicle. It can also be used with a complete ossicular chain, whether functioning normally or not. The present invention can also be used with prosthesis for use in the middle ear in place of, or instead of, one or more parts of the ossicular chain. Thus, the present invention has general applicability to structure in the middle ear, whether such structure is natural or artificial.
[0053] FIG. 2 illustrates the attachment device 26 with a wire-form structure 34 in an open loop configuration. The wire-form structure 34 comprises at least wire-form loop 30 and open loop 32 , and is preferably made from a single biocompatible wire 28 . The open loop 32 is adapted to mount around or over the selected ossicular portion or middle ear prosthesis. The illustrated embodiment of the open loop 32 includes one wire 28 which is configured into a double-wire open loop 32 . The internal loop diameter of the open loop 32 should be larger than the outer diameter of an ossicle so as to fit loosely around the ossicle. The preferred wire material is a biocompatible alloy of titanium, aluminum and vanadium (e.g., TiAl.sub.6 V.sub.4) or a nickel-titanium alloy with shape memory properties.
[0054] The wire-form loop 30 is connected to the open loop 32 . The wire-form loop 30 is adapted to mount over the illustrated housing-magnet assembly 22 . As illustrated, the wire-form loop 30 is disposed around the housing 22 . This loop has a press fit around the housing 22 such that once the housing 22 is positioned relative to the wire-form loop 30 in a desired position (such as nominally 0.2 mm from the lid-end of the housing 22 for the illustrated implementations), the compressive force of the wire-form loop 30 around the outside of the housing 22 retains the housing 22 in that position. Alternatively, the wire-form loop 30 may be welded to the housing or a portion of loop 32 may be welded to the housing to create a rigid connection to the housing.
[0055] FIG. 3 illustrates the attachment device 26 of the present invention utilizing a wire-form structure 34 and biocompatible cement 68 to attach the housing to a portion of the ossicular chain 66 . Preferably, the cement forms completely around the ossicle like a cast thus creating a rigid connection of the housing assembly to the ossicle.
[0056] FIG. 4 illustrates the wire-form structure 34 in an open loop configuration made with a band 35 . The wire-form structure 34 is made from a single biocompatible band 35 having a first portion or loop 38 adapted to mount around, or over, the selected ossicular portion or middle ear prosthesis, and a second portion 40 , contiguous with the first portion or loop 38 .
[0057] The internal loop diameter of the first portion 38 should be larger than the outer diameter of the ossicle so as to fit loosely around the ossicle. The band 35 is nominally 0.1 mm thick. The preferred wire material is a biocompatible alloy of titanium, aluminum and vanadium (e.g., TiAl.sub.6 V.sub.4) or a nickel-titanium alloy with shape memory properties.
[0058] The second portion or loop 40 is connected to the first portion or loop 38 . The loop 40 is adapted to mount over the housing assembly 22 . The second portion or loop 40 is disposed around the housing 22 . As previously described, this loop has a press fit around the housing 22 such that once the housing 22 is slid relative to the loop 40 to a desired position (such as nominally 0.2 mm from the lid-end of the housing 22 for the illustrated implementations), the compressive force of the loop 40 around the outside of the housing 22 retains the housing 22 in that position. Alternatively, the loop 40 may be welded to the housing or a portion of open loop 38 may be welded to the housing to create a rigid connection to the housing.
[0059] In FIG. 5 , the attachment device 26 is in the form of a clamshell loop configuration made with a wire. The wire-form structure 34 is made from a single biocompatible wire 28 . The clamshell loop 44 is adapted to mount around or over the selected ossicular portion or middle ear prosthesis. The illustrated clamshell loop 44 includes one portion which may be configured into a double-wire clamshell loop 45 as shown. The internal loop diameter of the wire clamshell loop 45 should be larger than the outer diameter of the ossicle so as to fit loosely around the ossicle. The wire is nominally 0.15 mm diameter.
[0060] The preferred wire material is a biocompatible alloy of titanium, aluminum and vanadium (e.g., TiAl.sub.6 V.sub.4) or a nickel-titanium alloy with shape memory properties.
[0061] The wire loop 46 is connected to the double-wire clamshell loop 45 . The wire loop 46 is adapted to mount over the illustrated housing-magnet assembly 22 . The loop 46 is disposed around the housing 22 , and holds the attachment device 26 to the housing 22 of the implant 20 in the manner previously described.
[0062] Alternatively, the wire loop 46 may be welded to the housing or a portion of double-wire clamshell loop 45 may be welded to the housing to create a rigid connection to the housing.
[0063] FIG. 6 is a view of the wire-form structure 34 in a clamshell loop configuration made with a band, which maybe the same as the band 35 illustrated in FIG. 4 . The wire-form structure 34 is made from a single biocompatible band 35 . The clamshell loop 50 is adapted to mount around or over the selected ossicular portion or middle ear prosthesis. The internal loop diameter of the clamshell loop 50 should be larger than the outer diameter of the ossicle so as to fit loosely around the ossicle. The band is nominally 0.1 mm thick. The preferred wire material is a biocompatible alloy of titanium, aluminum and vanadium (e.g., TiAl.sub.6 V.sub.4) or a nickel-titanium alloy with shape memory properties.
[0064] The loop band 52 is connected to the clamshell loop 50 . The loop 52 is adapted to mount over the illustrated housing-magnet assembly 22 . As shown in the drawings, the loop 52 is disposed around the housing 22 . and holds the attachment device 26 to the housing 22 of the implant 20 in the manner previously described.
[0065] Alternatively, the loop 52 may be welded to the housing or a portion of clamshell loop 50 may be welded to the housing to create a rigid connection to the housing.
[0066] FIG. 7 is a view of the wire-form structure 34 in a U-shape configuration made with a wire. The wire-form structure 34 is made from a single biocompatible wire 28 . The U-shape loop 56 is adapted to mount around or over the selected ossicular portion or middle ear prosthesis. The U-shape loop 56 includes one portion which is configured into a double-wire U-shape 57 . The internal loop diameter (distance between the wires) in the U-shape loop should be larger than the outer diameter of the ossicle so as to fit loosely around the ossicle. The wire is nominally 0.15 mm diameter. The preferred wire material is a biocompatible alloy of titanium, aluminum and vanadium (e.g., TiAl.sub.6 V.sub.4) or a nickel-titanium alloy with shape memory properties.
[0067] The single-wire loop 58 is connected to the double wire U-shape 57 . The loop 58 is adapted to mount over the illustrated housing-magnet assembly 22 . As shown in the drawings, the loop 58 is disposed around the housing 22 , and holds the attachment device 26 to the housing 22 of the implant 20 in the manner previously described.
[0068] Alternatively, the loop 58 may be welded to the housing or a portion of U-shape 56 may be welded to the housing to create a rigid connection to the housing.
[0069] FIG. 8 is a view of the wire-form structure 34 in a U-shape configuration made with a band. The wire-form structure 34 is made from a single biocompatible band, which may be the same as the band 35 illustrated in FIG. 4 . The U-shaped portion 62 of wire-form 34 is adapted to mount around or over the selected ossicular portion or middle ear prosthesis. An opening or aperture 63 may be provided in the U-shaped portion 62 of wire-form 34 . The distance between the arms of the U-shaped portion 62 should be larger than the outer diameter of the ossicle so as to fit loosely around the ossicle. The band 35 is nominally 0.1 mm thick. The preferred wire material is a biocompatible alloy of titanium, aluminum and vanadium (e.g., TiAl.sub.6 V.sub.4) or a nickel-titanium alloy with shape memory properties.
[0070] The remaining loop 64 is connected to the U-shaped portion 62 . The loop 64 is adapted to mount over the illustrated housing-magnet assembly 22 . As shown in the drawings, the loop 64 is disposed around the housing 22 and holds the attachment device 26 to the housing 22 of the implant 20 in the manner previously described.
[0071] Alternatively, the remaining loop 64 may be welded to the housing or a portion of U-shaped portion 62 may be welded to the housing to create a rigid connection to the housing.
[0072] It will be obvious to one skilled in the art that one or more wires or bands may be used to create variations on these configurations with a rigid attachment of the wireform to the housing and a loose fit of the wireform around the ossicle.
[0073] FIG. 9 is a close up illustration of the attachment device 26 of the present invention when only biocompatible cement 68 used to attach the housing 22 of the implant 20 to a portion of the ossicular chain 66 . Preferably, the cement forms completely around the ossicle and the housing like a cast thus creating a rigid connection of the housing assembly to the ossicle.
[0074] FIG. 11 , in addition to showing the features of FIG. 1 , also includes two dotted lines ( 80 , 81 ) indicating the natural path of alignment ( 80 ) of the angled ossicle, and the path needed to be in optimal alignment with the ear canal ( 81 ) (i.e. not at an angle to the transducer).
[0075] FIG. 12 illustrates the misalignment of a clamped magnet housing 90 on an angled ossicle 92 , while FIG. 13 illustrates a properly aligned magnet housing 22 using attachment device 26 to hold the implant 20 on the angled ossicle 92 .
[0076] Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent within. While preferred embodiments of the invention have been described for the purposes of this disclosure, changes in the construction and arrangements or parts and performance of steps can be made by those skilled in the art, which changes are encompassed within the spirit of this invention as defined by the claims.
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An improved middle ear implant and method are disclosed. The invention particularly relates to magnetic implants and to attachment devices and methods for mounting a magnet in the middle ear of a patient. The implant comprises a wire-form and a magnet disposed in a housing. The method may comprise the steps of: positioning a magnet in optimal alignment; and attaching said magnet to an ossicle in the middle ear. The method may further comprise the step of using a wire-form to attach the implant to the ossicle. Still further, the method may comprise the step of anchoring the implant to the ossicle with biological cement.
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FIELD OF THE INVENTION
[0001] This disclosure relates to water treatment systems. Additionally, this disclosure relates to an apparatus for performing water filtration purification, and more specifically, reverse osmosis water filtration purification.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to water filtration purification systems including a plurality of filter cartridges connected together in series for selectively and sequentially removing specific kinds of impurities from an incoming water supply. A typical water filtering system used in purifying water includes a reverse osmosis (hereinafter, “R.O.”) semi-permeable membrane. Typically, the filtration process through an R.O. membrane requires a driving force, most commonly the pressure from a pump or city water lines, to be applied to incoming feed water in order to force the feed water through the membrane. The membrane filters impurities from the feed water leaving the impurities on the feed water side of the membrane, and purified product water on the other side of the membrane. Most R.O. filtration technology also uses a process known as crossflow to allow the membrane to continually clean itself. In this process, only a portion of the feed water passes through the membrane becoming product water. The portion that does not pass through the membrane is flushed downstream for disposal through a drain port, thus sweeping the rejected impurities away from the membrane and reducing the scaling that occurs on the surface of the membrane. Many applications require that more than one filter be employed in series to selectively remove specific impurities. This series of filters is needed due to the fact that some R.O. membrane filters and other specialty filters are sensitive to, or do not work well if the incoming water contains certain chemicals or impurities, like chlorine for example. In these situations, the chlorine is first removed from the feed water by passing through an upstream pre-filter before moving to the chlorine-sensitive filter or R.O. membrane positioned downstream in the R.O. filtration system.
[0003] R.O. filtration purification systems are increasingly being employed to purify municipal and well water supplies to provide improved drinking water by decreasing the total dissolved solids in the municipal or well water, and thereby improving the taste, odor, or chemical makeup of the water.
[0004] Therefore, today there are many versions of R.O. filtration purification units that reduce specific contaminants and/or organics to improve the quality of drinking water. Filter and R.O. membrane cartridges (hereinafter “filter cartridges”) utilized in R.O. water treatment systems generally have a standardized cylindrical configuration including entry and outlet structures for attaching the filters to other system elements. Filter cartridges commonly utilized today also have different standardized diameters and lengths depending on whether the filter cartridge is meant for residential or commercial use. Many of the filter cartridges used in the market today are placed by hand in standardized cup shaped filter housings then attached to the main filter manifold. Once the filter housing is attached to the main filter manifold, the combined filter housing and manifold form a pressure vessel commonly called a filter sump. Incoming feed water then passes into the filter sump under pressure via an inlet port, through the filter cartridge contained therein, and exits the filter sump via an exit port in the filter manifold.
[0005] Current R.O. water treatment systems employ various techniques to attach the filter housings, which house the filter cartridge, to the main filter manifold. Some systems screw the filter housing to the manifold, some pin the filter housing to the manifold, while still others use bayonet style locking to attach the filter housing to the manifold. There are several disadvantages associated with each of these techniques.
[0006] First, a “cup-type” filter housing is essentially a cylindrical cup shaped container in which the filter cartridge is placed before being connected to the main manifold, thus creating a pressure vessel in the form of a filter sump. This type of filter housing has either a threaded lip in order to screw onto a similarly threaded filter manifold, a grooved lip so that it may be clipped or pinned to the filter manifold, or a bayonet style lip to be connected to a manifold that accepts bayonet style sumps. When dealing with “cup-type” filter housings, the user installing the filter cartridge must touch the outsides of the cartridge, including the filter material itself, with his hands in order to install the filter cartridge in the Cup shaped filter sump. This leads to potential contamination of the filter cartridge if proper sanitary methods or protective gear are not used.
[0007] Second, because the filter cartridges used in “cup-type” filter housings must be installed in the filter housing by hand, the tested and certified filter cartridges can be potentially altered from their tested and certified state. Additionally, because filter cartridges generally have a standardized configuration, off-brand replacement cartridges may be used which may not carry the certification of the original cartridges, and if used, may void any and all health claims presented to the end user of the main R.O. water treatment system.
[0008] Third, another popular proprietary filter housing and filter cartridge used in the marketplace is one in which the filter housing fully encapsulates the filter media within a sealed plastic housing and uses a bayonet locking method to attach the filter to the filter manifold as previously mentioned. This method is an effective deterrent against uncertified aftermarket replacements. It also maintains the sanitary handling desired for that brand of filter cartridge because the filter is encapsulated and certified at the factory. The consumer never has the opportunity to inadvertently or purposely contaminate the filter. However, when replacing the filter cartridge, there is an environmental disadvantage in that the user is not only disposing of the old filter, but he is also disposing the large amount of plastic that was used to encapsulate the filter which may end up in a land fill. This is also an undesirable result.
[0009] Fourth, all of the R.O. water treatment system designs currently used in the market today use filter cartridges of preset lengths and diameters. Those systems are designed for use with one filter cartridge size and do not currently have the ability to utilize filter cartridges of varying sizes. This does not allow the user to utilize filter cartridges of larger or smaller diameters or lengths, depending on his particular needs. This is an additional drawback to existing systems.
SUMMARY OF THE INVENTION
[0010] According to the present invention herein disclosed, the main system manifold of the water treatment system includes an upper and lower manifold that are hot plate welded together to form a single unit. The main manifold further includes the cylindrical filter housings which are integrally molded directly into the main manifold, thus forming a solid one-piece manifold with integral filter housings, rather than having the filter housings as separate containers to be attached to the manifold. While other systems also use hot plate welding to create a single manifold design, those systems do not however integrally mold the filter housings into the single manifold. Additionally, the filter cartridges to be inserted into the filter housings include integrated filter housing caps that are permanently connected to the cartridges.
[0011] By molding the cylindrical filter housing, which is the main cylinder portion of a traditional filter sump, into the main filter manifold assembly and permanently attaching the filter housing cap to the filter cartridge itself, all handling of the cartridge can be done via the cap thus eliminating potential contamination of the filter media itself. Additionally, the proprietary filter cartridge, which contains an integrated filter housing cap, helps ensure that no after-market or off-brand filters can be used with the main manifold, thus helping to maintain the originally designed health and environmental parameters of the main system. Furthermore, by minimizing the amount of material used in molding the filter housing cap to or permanently attaching the filter housing cap to the filter cartridge, the amount of plastic that may go to a landfill when the filter cartridge is replaced will be minimized as compared to the prior art filter cartridges that fully encapsulate the filter media with plastic.
[0012] In another aspect of the invention, the filter housing that is designed to be a R.O. membrane housing contains therein at least two staircased and concentric R.O. membrane brine seal housings of differing diameters and heights. These brine seal housings are sized to accept and allow use of both the standard sized residential R.O. membranes and the standard sized commercial R.O. membranes which each have different brine seal diameters. Additionally, more brine seal housings of differing heights and diameters could also be included which would allow use of membranes with custom brine seal diameters. Thus the invention allows users to change the size of membrane that is being used in the system based on the particular demands placed on the system.
[0013] In still another aspect, the invention is a customizable water treatment manifold in that it allows use of filter cylinder extension modules that attach to the integrally molded filter/membrane housings, thus allowing users to utilize filters or membranes of various standard or customizable lengths. Again, the user can choose the length needed based on the particular demands of the system.
[0014] In an additional aspect, the invention is a water treatment system that may be connected in parallel to at least one additional identical system such that they form and operate as one single, larger unit. In this manner, water may flow back and forth between each of the two systems for various levels of processing. Furthermore, in yet another aspect, the invention is also a water treatment system which optionally includes an integrated storage tank as opposed to only utilizing a satellite storage tank. The storage tank is customizable to be used as either an integrated tank or a satellite tank. The water treatment system can thus be customized to use either an integrated tank, a satellite tank, or both an integrated tank and satellite tank at the same time as additional storage capacity is needed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a front view of a conventional prior art reverse osmosis filtration purification system.
[0016] FIG. 2 is an isometric view of a fully assembled water treatment system utilizing a one-piece manifold with integral filter housings made in accordance with the present invention (storage tank not shown).
[0017] FIGS. 3 and 4 are exploded views of the main assembly showing the upper manifold and lower manifold.
[0018] FIG. 5 is a front view of a residential R.O. membrane cartridge and a commercial R.O. membrane cartridge, each having different brine seal diameters.
[0019] FIG. 6A is a cross sectional view of a filter housing cap hot glued onto the end of a carbon block filter cartridge.
[0020] FIG. 6B is a cross-sectional view of a filter housing cap spun welded onto a R.O. membrane cartridge.
[0021] FIG. 7 is an exploded view of one embodiment of the water treatment system of FIG. 2 (storage tank not shown) utilizing cylinder extension modules.
[0022] FIG. 8 is a top view of the R.O. membrane housing of the manifold with integral filter housings of FIGS. 3 & 4 showing the various sized brine seals therein.
[0023] FIG. 9 is a cross-sectional view of the manifold with integral filter housings showing the various sized brine seals of the R.O. membrane housing and a corresponding filter cartridge.
[0024] FIG. 10A is an exploded view of a filter housing, a filter cartridge with integral housing cap, and a housing cap retaining pin with retaining pin release clip.
[0025] FIG. 10B is a side view of a filter housing with a filter cartridge loaded therein and the filter housing cap secured in place by a housing cap retaining pin.
[0026] FIG. 11 is a view of the housing cap retaining pin being used as a filter cartridge removal tool.
[0027] FIG. 12 is a view of one embodiment of a dedicated filter cartridge removal tool.
[0028] FIG. 13 is an exploded view of an integrated water storage tank and the main manifold assembly with an adapter plate mounted there between.
[0029] FIG. 14 is a close-up isometric view of the water pathways, pathway gate notches, and corresponding pathway modification gates that fit into the pathway gate notches of the lower manifold.
[0030] FIG. 15 is a view of the assembled drain barrel inside the drain flow restrictor port.
[0031] FIG. 16 is a close up view of the drain barrel of FIG. 15 .
[0032] FIG. 17 is an isometric view of an embodiment made in accordance with the present invention wherein two individual main assemblies have been connected by their lower manifold's to form one larger unit.
[0033] FIG. 18 is an isometric view of an embodiment made in accordance with the present invention, wherein the main assembly has been combined with an auxiliary piece of equipment such as a fourth filtration sump, a pump, an electronic monitoring and control device, or a UV module.
[0034] FIG. 19 is an isometric view of the fully assembled preferred embodiment of the system of FIG. 2 , wherein the system of FIG. 2 has been combined with an integrated storage tank as in FIG. 14 , and an additional decorative cover.
[0035] FIG. 20 is an isometric view of the system made in accordance with the present invention wherein the storage tank utilized is a separate satellite storage tank.
[0036] FIGS. 21 & 22 are isometric views of alternate embodiments of the storage tank made in accordance with the present invention, wherein the tank is used as a satellite storage tank, is physically linked to a second storage tank using the tank's mounting fasteners and a plurality of universal mounting brackets.
DETAILED DESCRIPTION OF THE INVENTION
[0037] While the present invention is capable of embodiment in various forms, there is shown in the drawings, and will be hereinafter described, one or more presently preferred embodiments with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiments illustrated.
[0038] Referring to FIG. 2 , water filtration system 100 of the present invention is disclosed. System 100 includes a lower manifold 114 , an upper manifold 112 , a plurality of filter housings 116 - 120 , a plurality of filter cartridges 134 - 138 each including an integrated filter housing cap 146 (of which only the filter housing caps 146 are visible in FIG. 2 ), and a storage tank 194 (shown in FIGS. 14 & 19 - 22 ).
[0039] In the preferred embodiment, the upper manifold 112 and lower manifold 114 are generally rectangular in shape, however, the disclosure of this embodiment should not be read to limit the shape of the upper and lower manifolds. The filter housings 116 - 120 and the filter cartridges 134 - 138 seated primarily inside of the filter housings 116 - 120 (See FIG. 9 ), are generally cylindrical in shape. The filter housing caps 146 of the filter cartridges 134 - 136 are also generally cylindrical in shape and form a liquid tight seal with the inner walls of filter housings 116 - 120 . However, the disclosure of this embodiment should not be read to limit the shape of either the filter housings 116 - 120 , the filter cartridges 134 - 138 , or the filter housing caps 146 . Rather the filter housings 116 - 120 and filter housing caps 146 are shaped to accommodate and compliment the shape of the filter cartridges 134 - 138 . As such, in alternate embodiments of the matter disclosed herein, the filter cartridges, housings, and filter housing caps may take on additional shapes other than those disclosed herein. Additionally, although the preferred embodiment of FIG. 2 depicts three filter housings 116 - 120 and three filter cartridges 134 - 138 , this should not be read to limit the number of filter cartridges 134 - 138 or housings 116 - 120 that may be incorporated in the practice of alternate embodiments of the matter disclosed herein.
[0040] Referring to FIGS. 3 & 4 , the upper manifold 112 includes filter housings 116 - 120 , which are integrally molded thereto, forming a single molded piece. In the preferred embodiment, the integrally molded filter housings 116 - 120 of upper manifold 112 are a sediment pre-filter housing 116 , an R.O. membrane housing 118 , and a carbon post-filter housing 120 . However, the disclosure of this embodiment should not be read to require that a R.O. filter always be utilized in the practice of this invention nor should the disclosure of this embodiment be read to limit the use of the filter housings to only those filters previously discussed. Alternatively, in other embodiments, the filter housings may be used for alternate types of filters and/or membranes such as, but not limited to, sediment filters, sediment/carbon block combination filters, carbon block filters, granulated activated carbon filters, and KDF filters and may be arranged in a different order than that disclosed herein. Additionally, upper manifold 112 also includes all manifold control ports which are the inlet control port 124 , the satellite storage tank control port 126 , the faucet control port 128 , and the drain water control port 122 . The upper manifold 112 further includes a drain flow restrictor port 130 , a shutoff diaphragm valve port 129 , a check valve port 131 , and the upper half of the water pathways 132 a (see FIGS. 3 & 4 ). The function of the check valve port 131 is to prevent water contained in the storage tank from draining back to the drain port control 122 when the air gap faucet connected to the faucet control port 128 is shut off and not dispensing product water.
[0041] The lower manifold 114 includes the lower half of the water pathways 132 b (see FIG. 3 ) and a plurality of fluid flow configuration ports 140 (see FIG. 4 ). Both the upper manifold 112 and the lower manifold 114 are made from a high strength material such as, but not limited to, GFN3 which is 30% glass filled Noryl (a polymer manufactured by GE Plastics), GTX (a polymer manufactured by GE Plastics), or Xyron (a polymer manufactured by Asahi Thermofill, Inc.). The upper manifold 112 and the lower manifold 114 are hot plate welded together to form the main filter assembly 110 , (see FIGS. 3 & 4 ) which thereafter is one solid piece. When the upper and lower manifolds 112 & 114 are hot plate welded together, the upper half of the water pathways 132 a aligns and seals with the lower half of the water pathways 132 b to become one hermetically sealed set of water pathways 132 . Although in the preferred embodiment the upper and lower manifolds are hot plate welded together, in alternate embodiments, they may be fusion bonded together, sonic welded together, or joined together in any other manner that provides a hermetic seal therebetween.
[0042] Having the filter housings 116 - 120 molded into the upper manifold 112 , and thus the main assembly 110 following the hot plate welding procedure, is unique to the R.O. system 100 disclosed herein. The advantages of integrally molding the filter housings 116 - 120 into the system's main assembly 110 will be discussed below.
[0043] Referring to FIG. 5 specifically depicting a residential 160 and a commercial 166 R.O. membrane cartridge, but generally applicable to all filter cartridges, the filter cartridges 134 - 138 include a filter media portion 168 , a filter housing cap 146 , and a fluid seal connector 169 . If the filter cartridge is an R.O. membrane cartridge as in FIG. 5 , then the filter media portion 168 is essentially a molded, hollow, and perforated plastic tube, having multiple layers of various filter materials wrapped thereon. If, however, the filter cartridge is a pre or post-filter such as a carbon block filter, then the filter media portion 168 is generally either a porous, extruded cylindrical filter media solid having a hollow cylindrical center, or it is a perforated cylindrical plastic housing filled with a particular granulated filter media (not shown). The creation of various types of filter media is well known in the art and will be understood by those skilled in the art and will not be repeated herein. The filter media 168 is the portion of a filter cartridge through which feed water is forced in order to remove the water's impurities. Generally, feed water surrounds the outer cylindrical surface of the filter media portion, passes through the outer surface of the filtration media and into the hollow center, and travels down the hollow center and out of the filter housing in order to move downstream to the next filtration stage.
[0044] The filter housing cap 146 is generally a cylindrical, tubular sidewall that is closed off at one end by a concentric, circular shaped top wall joined thereto. The cap 146 includes a mating and sealing portion defined by the outer surface of the cap's 146 cylindrical sidewall and further includes a decorative domed grill on the outer surface of the circular shaped top wall. The inner surface of the cap's 146 top wall is generally flat. The cap 146 is generally made from high strength plastic but can be alternatively made from other high strength materials. The filter housing cap 146 includes at least one liquid sealing o-ring 147 seated around the outer circumference of the mating portion of the filter housing cap 146 , a retaining pin retention groove 176 recessed in the full outer circumference of the cap and positioned between the o-rings 147 and the cap's 146 top wall, and a plurality of housing cap removal tool holes 180 situated in the outer decorative grill of the housing cap 146 . The o-rings 147 are what form the liquid tight seal between a filter housing 116 - 120 and the filter housing cap 147 when the two are mated together. The retention groove 176 is the feature on the cap 146 that, when engaged by a retention pin 170 , keeps the housing cap secured in place when the filter sumps 148 - 152 , which are the pressure vessels formed by mating the cartridges into the filter housings, become pressurized due to water flowing through the system 100 . The cap removal tool holes 180 are essentially thru holes into which a cap removal tool 182 is hooked to help pull the mated housing cap 146 off of the filter housings 116 - 120 when the filter cartridges need to be removed.
[0045] The fluid seal connector 169 is the portion the filter cartridge 134 - 138 that connects the filter media portion 168 to the manifold's housing outlet port 186 . It also provides the path through which water, which has just passed through a particular filter inside of a filter sump, is reintroduced back into the manifold's water pathways 132 for further processing downstream or for dispensing, depending on where the particular filter is located in the process. The fluid seal connector 169 includes a filter connection nipple 163 containing at least one o-ring 147 thereon, such that, when the nipple 163 is mated with the housing outlet port 186 , a fluid tight seal is created there between, thus reducing the possibility that unfiltered water can reenter the system prior to being filtered. Also, when the filter in question is a R.O. membrane filter, the fluid seal connector 169 further contains a brine seal 158 or 164 which forms a liquid tight seal with an appropriately sized brine seal housing 156 or 162 . The liquid tight seal formed between the brine seal 158 or 164 and brine seal housing 156 or 162 separates the pre-filtered inlet water coming into the membrane sump 150 from the crossflow drain water which leaves the system as waste for disposal.
[0046] Referring to FIG. 6B , for the R.O. membrane cartridges 136 , the cap 146 is preferably spun welded onto the molded tube portion of the filter media 168 , thus becoming permanently attached or incorporated into the cartridge and creating a new proprietary disposable filter cartridge. Alternatively, the filter housing cap 146 can be integrally molded into a filter cartridge, snapped or press-fit onto the filter media portion 168 , or glued onto the end of the filter media portion as is done with many carbon block filters and seen in FIG. 6A , thus creating one solid cartridge and cap unit. Referring to FIG. 6A , when the cap 146 is hot melt glued to the open end of an extruded carbon block filter, the glue forms the seal on the open end of the hollow cylinder preventing water from entering into the center of the cylinder without first passing through the filtration material. With such a filter cartridge design, if the filter media portion 168 of a filter cartridge 134 - 138 is removed or separated from the filter housing cap 146 , it renders the filter cartridge unusable. In a preferred embodiment, filter cartridges 134 - 138 are a sediment pre-filter cartridge 134 to be loaded into the pre-filter housing 116 , a R.O. membrane cartridge 136 to be loaded into the R.O. membrane housing 118 , and a carbon post-filter 138 to be loaded into a post-filter housing 120 .
[0047] When each filter housing 116 - 120 is capped off with a filter housing cap 146 containing at least one o-ring seal 147 , the combined parts form a series of sealed filter sumps 148 - 152 , as previously mentioned. A filter sump is simply a pressure vessel, inside of which water will pass, under pressure, through the filter media 168 of the filter 134 and 138 or membrane 136 contained therein. Referring to FIG. 7 , because of the system's integrated filter housings 116 - 120 , an alternate embodiment of the invention disclosed herein allows for use of cylinder extension modules 154 to be coupled to the open, uncapped ends of the filter housings 116 - 120 . The caps 146 may then be secured to the open ends of the cylinder extension modules 154 creating a liquid tight seal. In this manner, the main assembly 110 is altered to allow the system 100 to use longer filter cartridges 167 which in turn will increase the product water output potential.
[0048] Referring to FIGS. 5 & 8 - 9 , the aforementioned filter housings 116 - 120 , at either their standard lengths or extended lengths, via cylinder extension modules 154 , are capable of receiving multiple filters and membranes of various diameters. The membrane housing 118 specifically has, but is not limited to, two staircased brine seal housings 156 and 162 attached to the flat, bottom, inner surface of the membrane housing 118 and extending upwards in the same direction as the housing itself (See FIGS. 8 & 9 ). The first brine seal housing 156 has been sized to accept the brine seal 158 of the standardized residential diameter R.O. membrane cartridge 160 while the second brine seal housing 162 has been sized to accept the larger diameter brine seal 164 of standardized commercial diameter R.O. membrane cartridges 166 (See FIG. 5 ). Alternatively, additional brine seal housings may be utilized and sized to accept unique membrane brine seals of nearly any diameter in the practice of an embodiment of the invention disclosed herein.
[0049] The preferred embodiment which incorporates the cap 146 and filter cartridge 134 - 138 into one unit has several advantages over prior standard cartridge configurations. First, when installing most standard filter cartridges, the filter media must be touched by the user's hand creating the potential to contaminate the filter media 168 and the entire system if proper sanitary methods or protective gear is not used. However, when using the one-piece manifold with integral filter housings, all handling and installation is done by the outside edges and surface of the cap 146 which never comes in contact with the water in the system 100 , thus eliminating the potential contamination of the filter media 168 . Second, unlike current filter cartridges, tested and certified filtration media cartridges made in accordance with the invention cannot be altered from their tested and certified state. Many off brand replacement filters do not carry the certification that the original cartridges do and if used may void any/all health claims presented to the end user of the main RO unit. By controlling the supply of certified filter cartridges, the manufacturer can ensure the product works as claimed. Third, unlike a popular proprietary filter cartridge used in the market today that fully encapsulates the filter media within a sealed plastic housing, the one-piece manifold with integral filter housings minimizes the amount of plastic that may end up in landfills upon disposal of the filter cartridge. When the aforementioned fully encapsulated filter media is disposed of, the user is disposing of not only the filter media inside, but the fairly large plastic housing that fully encapsulates the filter media as well. With most other filtration systems, this plastic filter encapsulation housing is usually meant to be a detachable, yet permanent part of the main system and is normally reused after replacing the filter media contained therein. By comparison, upon disposal of the filter cartridges 134 - 138 of the present invention, the filter media 168 , the filter housing cap 146 , and the filter connection nipple 163 are the only parts disposed of, while the main filter housings 116 - 120 which make up the largest portion of the filter sumps are reused with the new replacement filter cartridges. The obvious environmental advantage is that significantly less plastic may be disposed of in landfills upon cartridge replacement.
[0050] Referring to FIGS. 7 , 10 A, and 10 B, each cap 146 is secured to its filter housing 116 - 120 or cylinder extension module 154 by pinning the cap 146 to the open end of the filter housing 116 - 120 or cylinder extension module 154 using a horseshoe shaped retaining pin 170 . The filter cartridge 134 - 138 is first inserted into the filter housing 116 - 120 and the integral filter housing cap 146 containing o-rings 147 is fully seated in the open end of the filter housing 116 - 120 . Next the legs 172 of the retaining pin 170 are inserted through corresponding retaining pin engagement holes 174 located in the walls of the filter housing 116 - 120 . The legs 172 of the pin 170 slide through the engagement holes 174 in the filter housing 116 - 120 , engaging the corresponding retention groove 176 above the o-rings 147 in the outer circumference of the filter cap 146 , and emerging from pin engagement holes 174 on the opposite side of the filter housing 116 - 120 . When the legs 172 of the retaining pin 170 are engaged in the cap's retention groove 176 , they create an interference fit, thus securing the cap 146 in place and preventing it from being removed.
[0051] The retaining pins 170 that secure both the housing caps 146 in place and the filter cartridges 134 - 138 inside the filter housings 116 - 120 may become difficult to remove after the filter sumps 148 - 152 have been pressurized for a long time. To aid in the removal of the retaining pin 170 , a release clip 178 is attached to the retaining pin 170 . The release clip 178 is manually pulled downward and the resultant lever action against the filter housing 116 - 120 ejects the pin 170 or moves the pin free from its resting place making it easier to remove. While the preferred embodiment uses pinning as the preferred method to connect the filter housing caps 146 or cylinder extension modules 154 to the filter housings 116 - 120 , alternatively the caps 146 and cylinder extension modules 154 can be connected by screwing, bayonet style locking, or any other method that would provide a secure connection between the caps 146 and housings 116 - 120 , the caps 146 and extension modules 154 , or the extension modules 154 and housings 116 - 120 .
[0052] Referring to FIGS. 11 and 12 , the retaining pin 170 , after it is removed, can also function as a filter cartridge removal tool. One leg 172 of the retaining pin 170 is inserted into one of a plurality of cap removal tool holes 180 located in the outer surface of the filter housing cap 146 and is used to twist and pull up on the filter cartridge's integral cap 146 in order to remove the filter cartridge 134 - 138 from its filter housing 116 - 120 (See FIG. 11 ). Preferentially however, a specially designed removal tool 182 that aids in the removal of filter cartridges 134 - 138 is employed to remove the filter cartridges 134 - 138 . The tool 182 is essentially a T-shaped handle with hooks 184 located on the vertical portion of the T that are used to engage the cap removal holes 180 in the filter cap 146 . The tool 182 is then used to twist and pull upwards on the filter cartridge 134 - 138 to remove it from the filter housing 116 - 120 (See FIG. 12 ). Alternatively, the tool can take the form of many other shapes as well, such as a simple U-shape.
[0053] Referring to FIG. 13 , due to the naturally long time it takes to process water through a R.O. membrane, a pressurized storage tank 194 is usually employed in the system 100 . Water which has already passed through the R.O. membrane collects and is temporarily stored in the storage tank 194 when the air gap faucet, through which the water will ultimately be dispensed, is shut off. Once the air gap faucet is opened, the pressure in the storage tank 194 is sufficient to force the treated water out of the tank, either for dispensing and use if it is fully processed product water, or for further processing downstream if it has been only partially-treated. In the preferred embodiment, the storage tank 194 is generally cylindrical in shape with hemispherical ends, however, the disclosure of this embodiment should not be read to limit the shape of the storage tank.
[0054] The tank 194 includes at least one tank fluid flow port 196 through which water enters and leaves the storage tank. The tank fluid flow port 196 is connected to either, the satellite storage tank control port 126 of the upper manifold 112 in the main assembly 110 if the tank is a satellite tank, or it is connected to one of the pathway configuration ports 140 (not visible in FIG. 13 ) of the lower manifold 114 in the main assembly 110 if the tank is an integrated tank. The tank 194 also includes an internal sealed, gas-pressurized bladder 198 (not visible). This bladder 198 is what provides the pressure to the water stored in the tank 194 in order to force it out of the tank 194 once the air gap faucet is opened. The internal workings of the tank 194 are well known in the art and therefore will not be addressed in any great detail. The tank 194 further includes a plurality of threaded fasteners 200 , integrally disposed in the outer surface of the storage tank 194 . Standard system designs use a satellite storage tank that is separated from the main filtration system assembly 110 . In the preferred embodiment however, the fasteners 200 allow the tank to mount to the main assembly 110 (See FIGS. 13 & 19 ) using threaded posts such as screws 202 or bolts and an integrated tank adapter plate 203 attached to the lower manifold 114 , thus creating an integrated single-unit R.O. system. Alternatively, the fasteners 200 may be snap-type cantilevered beams, holes to accept rivets or pins, bayonet type mounting holes to accept bayonet type screws, or any fastening means that will provide a robust field-removable linkage between the tank and the main manifold assembly 110 .
[0055] Referring to FIG. 13 , in the preferred embodiment, the tank also includes removable legs 204 which fasten to the tank 194 in the same manner as the tank fastens to the main assembly 110 . When the tank is used as a satellite tank, the legs 204 can be removed and reattached to the tank 194 via the fasteners 200 and screws 202 at another location on the tank's surface, in order to change the resting orientation of the tank 194 (See FIG. 20 ). Additionally, in alternate embodiments, more than one tank may be utilized to increase the storage capacity by using both an integrated tank and a satellite tank as described above, or, referring to FIGS. 21 & 22 , by using multiple satellite tanks that are physically linked together via a plurality of removable universal mounting brackets 206 and the fasteners 200 and screws 202 previously discussed. Furthermore, using the removable brackets 206 , the satellite tanks may be mounted to various structures in multiple orientations as needed, such as hanging vertically from a ceiling rafter or mounting horizontally to a wall.
[0056] In operation, the preferred embodiment of the invention disclosed herein works as follows: the filter cartridges 134 - 138 are loaded into the filter housings 116 - 120 and the integral filter housing caps 146 are secured in place with retaining pins 170 . Impute feed water enters the system via an inlet control connection port 124 and travels through the pre-filter 134 , the R.O. membrane 136 , and the post-filter 138 via the hermetically sealed water pathways 132 . Referring to FIG. 4 , the design of the lower manifold 114 is unique in that it has multiple pathway configuration ports 140 molded into it in a closed state to optionally be opened and used for alternate water pathway configurations. Additionally, referring to FIG. 14 , incorporated into the lower manifold's 114 design are multiple pathway gate notches 142 within the water pathways 132 that accept separate pathway modification gates 144 . The purpose of the configuration ports 140 , gates 144 , and notches 142 is to force the water to travel alternate paths and to flow into or out of various attachments when alternate embodiments are employed. Depending on the desired water flow path in and out of the main assembly 100 , prior to hot plate welding the upper 112 and lower 114 manifold together, select configuration ports 140 are drilled open and gates 144 are press fit or sonic welded into specific notches 142 in order to shut off specific internal ports or close off specific pathways 132 . This effectively changes the path the water will take through the water pathways 132 and the main assembly 110 , or changes the order in which the feed water enters the various filter sumps 148 - 152 . The opened configuration ports 140 are then connected to other opened ports 140 by tubes. In this manner, the system can be configured in a variety of ways to perform a variety of desired tasks. This procedure is also how the ports 140 are opened up to allow water to flow into and out of an integrated storage tank 194 as previously discussed as opposed to only utilizing a separate satellite storage tank. Referring to FIG. 17 , this design thus allows, in an alternate embodiment, two fully assembled main assemblies 110 to be joined to form a single unit by blocking their proper water pathways 132 with gates 144 , opening their proper configuration ports 140 , connecting their corresponding opened pathway configuration ports 140 with tubing, and mounting the lower manifolds of the two assemblies 110 together using an adapter plate (not shown). By doing so, water can flow between the two sets of water pathways of the two main assemblies 110 .
[0057] In the preferred embodiment, after entering the system via the inlet control port 124 , the impure feed water is first channeled down the water pathways 132 and into a pre-filter sump 148 containing a sediment pre-filter 134 used to remove dirt, sand, and other suspended solids. The feed water passes, under pressure, through the pre-filter 134 and exits the pre-filter sump 148 via a filter housing outlet port 186 where it re-enters the water pathways 132 .
[0058] Next, depending on the configuration of the water pathways 132 , the water enters an R.O. membrane sump 150 containing the R.O. membrane 118 used to remove bacteria, salts, and other dissolved solids. Most of the water in the membrane sump 150 passes through the membrane 118 contained therein, thus filtering out most of the total dissolved solids in the water. The water exits the R.O. membrane sump 150 in one of two paths. The first path is for water that passes through the R.O. membrane 118 , which is not the path taken by the majority of the water in the sump 150 . The first path carries the membrane filtered water from the R.O. membrane sump 150 down the water pathways 132 to a tank control port 126 which is connected to a satellite storage tank 194 . The storage tank 194 , pressurized to less than the feed water line pressure, holds the R.O. filtered water until an air gap faucet connected to the main assembly 110 is opened by a user. Once the faucet is opened, the water stored in the storage tank 194 is forced out of the storage tank 194 by the gas-pressurized bladder 198 contained therein. The water flows back through the tank control port 126 of the main assembly 110 and back into water pathways 132 of the main assembly 110 , where it then enters a post-filter sump 152 containing a carbon filter to remove impurities that affect the water's taste and odor. Once the water passes through the carbon post-filter, it leaves the post filter sump 152 , enters the water pathways 132 one last time, and travels through a faucet control port 128 , which is connected to the air gap faucet, in order to dispense the water from the faucet when called for by the user.
[0059] The second path through which water may exit the R.O. membrane sump 150 is for drain water which is routed to a drain water flow restrictor 130 . This is the path through which the majority of the water in the sump 150 flows. The large portion of the pre-filtered feed water that does not pass through the R.O. membrane 136 leaves the R.O. membrane sump 150 sump via a filter housing drain port located on the same side of the membrane as the housing's inlet port. This water is essentially concentrated waste water containing all of the impurities filtered out during the R.O. filtration process, which then leaves the system 100 through the main assembly's 110 drain control port 122 as drain water for disposal. By splitting off part of the incoming water as drain water rather than forcing all of the incoming feed water through the R.O. membrane 136 , the R.O. membrane 136 is constantly being cleaned and having the impurities discarded rather than allowing them to build up on and clog the pores of the membrane surface, thus significantly extending the life of the R.O. membrane 136 and the time until the membrane 136 needs to be replaced.
[0060] Referring next to FIGS. 15-16 , all R.O. units need to control the rate at which drain water leaves the membrane sump 150 while processing water through the R.O. membrane 136 . The cleaner the feed water, the less drain water needs to be split off and discarded. Controlling the drain rate is accomplished via the drain flow restrictor port 130 which contains a drain control barrel valve 188 . The drain barrel 188 has several orifices 190 located within it, through which drain water flows, which may be selectively opened or closed to increase or decrease the flow of the drain water. The drain barrel 188 is rotated in order to select various predetermined drain rates or ratios of drain water to product water. Two additional settings outside of the necessary incorporated drain ratios are “off”, which is a setting that completely closes the orifices 190 of the drain barrel and does not allow any water to flow through the drain flow restrictor 130 , and “fast flush,” which fully opens the drain barrel orifices 190 , flushing the majority of the water in the sump 150 to the drain for disposal. As membrane production rate technology improves, the need to send water to drain may be eliminated. The “off” position can be used for any reason no flow through the drain barrel 188 is desired, while the “fast flush” position allows for manually flushing the existing membranes currently being used in the industry. Alternatively, similar drain functions can be achieved in the practice of an embodiment of the matter disclosed herein by use of needle valves, ball valves, or any other valve technology which allows a user to selectively adjust flow rates through said valve.
[0061] Referring to FIGS. 17-19 showing alternate embodiments of the matter disclosed herein and as previously discussed, the lower manifold 114 is designed such that the main assembly 110 can accept accessory filtration devices or peripherals to it, or can be mounted directly to other drinking water devices. The design allows for two or more R.O. unit main assemblies 110 to be connected to each other and work as one larger unit (See FIG. 17 ). Additional alternate embodiments of the matter disclosed herein include the incorporation of, but are not limited to: auxiliary filter housings that can be implemented at any filtration stage desired; pumps, electronic monitoring and control devices, and UV modules connected to or mounted to the main assembly 10 (See FIG. 18 ); office water coolers and drinking fountains connected to or mounted to the main assembly 110 . The ability to incorporate electronic monitoring and control devices and other peripherals discussed above into various embodiments of the matter disclosed herein allows for an “auto flush” system to perform the drain rate monitoring functions, “fast flush” functions, and “no flow” functions discussed above, on time-based or volume-based flushing or cleaning schedules. Additionally, when an electronic monitoring and control module is incorporated by itself into an embodiment of the matter disclosed herein or with other incorporated modules, alarms can be used to indicate important information such as, but not limited to, filter replacement timelines, cleaning schedules, or unit maintenance.
[0062] Furthermore, in yet another embodiment, the system can utilize secondary membrane housings and be configured to allow parallel flow through two or more membranes 136 . Additionally, in yet another embodiment, a decorative cover 192 fits over the main assembly 110 to create the attractive appliance feel that the main assembly 110 is lacking (See FIG. 19 ). The cover 192 uses a variety of shapes and contours that accentuate the existing main assembly.
[0063] While the present invention has been described in terms of the embodiments depicted in the drawings and discussed above, it will be understood by one skilled in the art that the present invention is not limited to these particular embodiments, but includes any and all such modifications that are within the spirit and the scope of the present invention as defined in the appended claims.
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A water treatment system for removing impurities from incoming feed water includes a manifold having a plurality of water treatment filter housings connected thereto. The filter housings are configured to accept a plurality of water treatment filter cartridges, which have, at one end, a filter housing cap fixedly attached thereto. The system manifold is also adaptable to be able to connect to peripheral accessories, filtration devices, and identical water treatment systems.
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This invention relates in general to a method and apparatus for providing a reliable clock in an electronic system and, in particular, to a method and apparatus for disabling and restarting a clock in an interface device disposed between a microprocessor and a peripheral port, or in any device requiring an internal clock for synchronous operation which is able to retain full state information with the clock stopped.
BACKGROUND
With advances in microelectronic technology, many computer systems have shrunk to the size where they can be operated by batteries. In order to extend the life of such battery driven systems, it is often necessary to conserve power consumed by the components that comprise the system. In an effort to conserve power, designers have attempted to use low power systems and to turn off subsystems when they are not required. With low-power CMOS circuits, turning off the clock to a circuit will frequently reduce the power consumed by that circuit by several orders of magnitude.
With computer designs where subsystems are turned off, there is an inherent problem with restarting such subsystems. Computer systems generally operate from a common clock. So, all of the activities of the system occur on the change of state of the clock.
When the clock in a subsystem is disabled, it is a requirement that the subsystem be presented a reliable and stable clock signal internally when said clock is reenabled. In general, an event triggering the reenabling of the clock is asynchronous to the clock. A problem arises if the subsystem is reenabled at or about the same time as the system clock is changing state. It is well known that microelectronic components, in particular the D-type flip-flops which are common in microelectronic systems, can be driven into a metastable state if a narrow clock pulse is applied to such D-type flip-flops. It is highly desirable to avoid such occurrences since an unstable clock signal introduced into a subsystem could have a ripple effect throughout the subsystem causing the subsystem to fail and perhaps the entire computer system to fail.
Accordingly, it is an object of this invention to provide a stable and reliable internal clock signal within a component under all operating conditions, while not requiring any clock whatsoever when the clock is disabled.
It is another object of the invention to provide a stable and reliable clock signal to a component in a computer system when a previously disabled clock signal is restarted asynchronously to the clock.
Prior systems have included the ability to enable a clock going to a subsystem, provided that the clock control circuit was itself always provided with a valid clock. This invention differs by providing a "bootstrapping" method, allowing the clock to be removed from the entire subsystem. In the context of an integrated circuit, this significantly reduces the standby power of the circuit, by allowing the system clock to be disabled at the input pin of the device when the integrated circuit is in a standby mode.
SUMMARY OF THE INVENTION
A method and apparatus are provided that use a series of flip-flops, each with a known, predetermined state. In the preferred embodiment, the flip-flops are D-type flip-flops formulated in CMOS technology. Each of the flip-flops receives an input clock signal. The first flip-flop in the chain also receives a known state signal at its input and that known state signal is opposite to the state of the output of the flip-flops at the beginning of the clock reenabling process. The last flip-flop in the chain has its complimentary output coupled to a logic circuit, preferably an OR circuit. The OR circuit also receives the input clock signal. In effect, the chain of flip-flops, at least two, and preferably three, comprises a shift register. The known input signal to the shift register is serially clocked through the flip-flops by the changing clock signals.
One of the features of this invention is the use of D-type flip-flops, implemented with transmission gates. With such flip-flops, the input signal is clocked to the output upon the rising edge of a clock signal. It is another feature of transmission-gate D-type flip-flops that if the input to the flip-flop is equal to its stored state and a narrow clock pulse occurs, the flip-flop will not change state. That is, such D-type flip-flops are resistant to entering into a metastable state so long as the conditions ensure that the input of the flip-flop is equal to its stored state whenever a narrow clock pulse occurs. By use of a chain of at least two and preferably three flip-flops, the foregoing condition is assured with extremely high probability by the time the signal has propagated to the end of the chain of flip-flops. As such, the circuit and method of the invention provides a known delay between the change of state of the last flip-flop and the change of state in the logic circuit that gates the clock signal to the rest of the subsystem that has been recently turned on, enabling it to operate synchronously to external components at the end of this known time interval.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer system with a microprocessor and a subsystem including the invention;
FIG. 2 is a schematic diagram of a circuit in the interface component that receives a clock signal from the microprocessor;
FIG. 3 is a further schematic diagram of a pulse processing circuit 30 of FIG. 3;
FIG. 4 is a state diagram of the invention;
FIG. 5 is a timing diagram of the invention.
DETAILED DESCRIPTION
With reference to FIG. 1, a computer system 20 is shown with a microprocessor 22 that is coupled to a peripheral port 26 via an internal ISA or similar system bus 24 and an interface component 10. The microprocessor 22 may be of any suitable type, examples of which are the Intel 486DX or a CYRIX 486SLC. The bus 24 is a standard ISA or PC/AT bus or other system bus. The system bus 24 carries a clock signal, CLK, to the interface component 10. Interface component 10 is a Databook DB86082 PC Card Controller for Notebook Personal Computers, for use with a system in compliance with PCMCIA standards. In this particular embodiment, the peripheral port 26 also complies with PCMCIA standards and can receive a peripheral device (not shown) such as a modem, flash memory card, fax, or any other suitable memory or input/output device that can be plugged into peripheral port 26.
One of the features of the controller 10 is that it is a totally static design. This allows its clock to be stopped internally or externally without loss of state information stored in its internal registers. Another feature of the controller 10 is its internal hardware logic which automatically disables the internal clock signal after the completion of a read or write cycle, placing the controller 10 in a low-power standby mode with no software intervention. This is achieved by internal gating; the CLK signal can remain active at the clock input pin to the controller 10 during this standby period. A feature of the invention is the reenabling of the internal clock a fixed period of time after an external, asynchronous wakeup event, a chip-select in the case of the DB86082 controller 10.
Turning to FIG. 2, there is shown a schematic diagram of the circuit of the invention that is useful for receiving the CLK signal from the microprocessor 22 and controlling whether the clock is passed on to the next stage of the circuitry within interface component 10. The CLK signal from the microprocessor 22 is input to a zero-power input buffer or other such gating device 116 at input line 114. Buffer 116 is controlled by a signal NCLKIE (not clock input enable) on line 18. When signal NCLKIE is active (low in the example circuit), the output signal, RAWCLK, follows the state of the input signal. When signal NCLKIE is inactive (high in the example circuit), RAWCLK is held in a known state regardless of any activity on the input signal CLK at line 114. Buffer 116 is the input buffer for interface component 10 and by driving signal NCLKIE to an inactive state, one can eliminate clock transitions on signal RAWCLK within interface component 10. If buffer 116 is implemented with a zero power buffer, then input transitions on line 114 will cause no power to be dissipated within interface circuit 10, so long as signal NCLKIE is in an inactive state. In the example circuits and diagrams, one assumes that when NCLKIE is inactive, buffer 116 will drive RAWCLK to a logic `1`.
When it is desired to restart the clock inside the interface component 10, it is necessary to change the state of signal NCLKIE to enable the three-state buffer 116 and thereby pass signal RAWCLK to the clock processing circuit 100. However, since no clock is available inside interface component 10, this transition of NCLKIE will necessarily occur asynchronously to the external clock CLK. Therefore, the signal RAWCLK may contain an initial pulse that is arbitrarily short in duration. This pulse may be shorter than the minimum clock period allowed by the circuitry inside component 10, and therefore may cause the circuitry inside interface component 10 to malfunction. The rest of the circuitry shown in FIG. 2 is designed to defend the rest of interface component 10 against such pulses.
Clock processing circuit 100 includes three CMOS transmission-gate D-type flip-flops 110, 112, 118. The RAWCLK signal is coupled to the clock input of each of the flip-flops 110, 112, 118. The Q output of flip-flop 110 is coupled to the D input to flip-flop 112. The Q output of flip-flop 112 is coupled to the D input of flip-flop 118. The complimentary or Q output of flip-flop 118 is denominated by a signal NRUNNING (not running). The signal NRUNNING provides one input to OR gate 120. The other input to OR gate 120 is RAWCLK. The output of OR gate 120 is the desired, reliable clock signal denominated COOKEDCLK.
Flip-flop 112 has its D input coupled to a source 180. The source 180 is a fixed signal source that provides a known state to the D input of flip-flop 110. The reset inputs to flip-flops 110, 112, are controlled by a signal SYNC1RST which is inverted prior to the reset input to derive signal NSYNC1RST to both reset inputs of flip-flops 110, 112. The reset input to flip-flop 118 is signal NSRESET. The signal NSRESET is the master reset signal for the controller 10. This signal is processed by pulse processing circuit 130 and logic gates 132, 134, and 136 to provide the SYNC1RST signal for flip-flops 110, 112 reset inputs. The other input signals to circuit 100 include FORCECLK, ASREQ, and STOPCLK. Those signals are likewise processed by logic gates 124, 126, 128 and pulse processing circuit 130 to provide the SYNC1RST signal as well as the cooked clock input enable signal CCLKIE.
The pulse processing circuit 130 is more fully shown in FIG. 3. There, the three inputs to the clock pulse enable circuit 130 are shown coupled through a series of D-type flip-flops 140, 142, 143 and an output AND gate 146 to provide the outputs of pulse processing circuit 130.
In order to understand the operation of the circuit 100, the following explanation will refer to FIGS. 2,4 and 5. The explanation will begin with an assumption that the NRUNNING signal is high, that the Q outputs of D-type flip-flops 110, 112, 118 are all zero and that the D-input 180 to flip-flop 110 is set high or one. With reference to FIG. 5, the circuit 100 will continue to idle in the not running state until the signal NCLKIE on the zero-power input or other gating buffer 116 changes state and connects the clock 114 to the clock input of flip-flop 110 as a RAWCLK signal. The signal NCLKIE is generated asynchronously by other circuitry (not shown) in component 10 in response to a command from microprocessor 22, or in response to other events detected asynchronously on inputs connected to circuitry external to component 10. Logic in component 10 recognize the command from the microprocessor as one directed to component 10 or one of its peripherals 26. At this time, signal CLK may be either high or low. If CLK is high, then RAWCLK 116 stays high until CLK goes low; if CLK is low, then RAWCLK 116 goes low immediately. Upon the occurrence of the next rising edge of the RAWCLK 116, shown as event 1 in FIG. 5, the circuit will enter a first intermediate state, IS 1. Upon such occurrence of the rising edge of RAWCLK 116, the one or high input at the D-input of flip-flop 110 will be clocked to its output. The outputs of flip-flops 112 and 118 will remain at their preset zero state. Upon the occurrence of the next rising edge of RAWCLK 116, the circuit 100 will enter its second intermediate state, IS 2. Upon the occurrence of the second rising edge of RAWCLK 116, the Q-output of flip-flop 110 that is coupled to the D-input of flip-flop 112 will be clocked to the output of flip-flop 112. Flip-flop 118 will remain with its output at zero. On the third rising edge of RAWCLK 116, the circuit 100 will change its state from not running to a running state. When RAWCLK 116 rises for the third time, the Q output of flip-flop 118 changes state from 0 to 1. Likewise, the complimentary output or Q output of 118 changes state from 1 to 0. The latter change in state of the complimentary output of flip-flop 118 causes logic circuit OR gate 120 to change its state. When OR gate 120 changes state, its output corresponds to the RAWCLK input signal and is denominated COOKEDCLK.
It will be recalled that during the not running state, D-type flip-flop 118 had its Q-output at zero and so its complimentary or Q output was 1. With one input to the OR gate 120 fixed as a 1, the output of the OR gate which is the COOKEDCLK signal, is a steady state output and does not change regardless of the variation of the other input, RAWCLK. However, once the NRUNNING input to OR gate 120 changes state to a zero at event 3, then, following the first falling edge of the RAWCLK 116, the output of 120 will follow the RAWCLK signal 116 and provide the COOKEDCLK signal as shown at event E6 in FIG. 5 and subsequent.
The circuit 100 idles in the running state as shown in FIG. 3 until the microprocessor and/or the PCMCIA interface component 10 determine that it is no longer necessary to use the PCMCIA component 10 and that it is desirable to terminate the clock signal within the component 10. Prior to stopping the clock, the flip-flops 110, 112, 118 are set into known states in a manner well-known in the art. As such, using the NSRESET signal, the Q outputs of flip-flops 110, 112, and 118 will all be placed in the zero state prior to any subsequent stopping of the clock.
Those skilled in the art will appreciate from the above description that circuit 100 is configured so there is approximately a one-half clock period delay between the change of state of the NRUNNING signal and the change of state of the output of OR gate 120. This half cycle delay is a consequence of gating the complementary output Q of flip flop 118 which has been set by the third rising edge of RAWCLK to a logic-low level into OR gate 120, while RAWCLK is still at a logic high level. Those skilled in the art will recognize that this delay ensures that the duration of the initial pulse of the COOKEDCLK will match the duration of the corresponding pulse of signal CLK. Were this delay not inserted, the first pulse of the COOKEDCLK would be shorted by the logic propagation times of flip-flop 118 and OR gate 120.
In addition, those skilled in the art will appreciate that D-type flip-flops fabricated with transmission gates, as is the common practice in complimentary metal oxide semiconductor technology, have particular characteristics when they are clocked by narrow pulses, too short to meet the normal requirement for a state transition. When the state of the flip-flop and its D input logic level are the same (both the state and the D input are at one or zero), such flip-flops will not change state upon the occurrence of a partial or narrow clock pulse. Thus, such flip-flops are resistant to being driven into metastability under these conditions. Those skilled in the art will appreciate that the above design and method calls for setting the D-type flip-flops in their known states and then using this characteristic of the flip-flops to guarantee that a reliable, stable clock signal is propagated.
Those skilled in the art will also appreciate that the above design could be implemented with as few as two D-type flip-flops. However, in the preferred embodiment, three flip-flops are chosen so as to ensure an extra measure of design margin. As such, if the first cycle of RAWCLK after the buffer or gating device 116 is enabled is an arbitrarily narrow pulse, the output of the first flip-flop 110 may become metastable. Those skilled in the art will know that such metastable conditions resolve in a random fashion, and that the mean-time-between failures of an asynchronous circuit is an exponential function of the form Ae -kt , where t is the metastable resolution period of the system, and A and k depend on the characteristics of the flip-flops and of the input signals and clocks. Therefore, by building in a delay of at least one other flip-flop 112, and preferably two flip-flops by adding flip-flop 118, there is a sufficient amount of time delay to ensure that a narrow clock pulse on the RAWCLK signal will not propagate through as a metastable condition to the cooked clock signal. Hence, if an arbitrarily narrow pulse caused a metastable condition at the Q-output of flip-flop 110, that metastable signal would still have to wait at least another entire clock cycle before being sampled by flip-flop 112.
Those skilled in the art will also appreciate that circuit 100 sets the D-type flip-flops 110, 112, 118 into their zero state before turning off the clock. The latter is accomplished by any one of a number of known techniques that is within the skill of those of the art. In the preferred embodiment, flip-flops 110 and 112 are reset to their zero state, then, that zero state, after one clock cycle, is clocked through to D-type flip-flop 118 thereupon the NCLKIE signal to buffer or gating device 116 is activated to set buffer or gating device 116 into its disconnected state.
Having thus described the preferred embodiment of the invention, those skilled in the art will appreciate that further modifications, changes, alterations, additions and deletions can be made thereto without departing from the spirit and scope of the invention as defined in the following claims.
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The ability to stop a clock in a CMOS peripheral device or other CMOS IC, and reliably restart it based on an asynchronous event, provides the basis for considerable power savings. In a computer system 20 an interface component 10 has a clock restart circuit 100. The restart circuit 100 includes a series of D-type CMOS flip-flops (110, 112, 118) that are initially set in their zero state. A logic OR gate 120 receives the microprocessor clock and the complimentary output of the last flip-flop to provide a reliable, restarted clock signal for the interface component 10 and its peripherals 26.
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This application is a continuation of application Ser. No. 08/826,805, filed Mar. 25, 1997 still pending.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a novel multiprocessor distributed memory system providing high-speed deterministic system connectivity, a novel PCI-based printed circuit board and methods therefor.
2. State of the Prior Art
Multiprocessor distributed memory systems are known and currently in wide use in the art. Such systems are characterized by certain deficiencies and can be substantially improved. For example, present systems essentially arbitrate resources in software and are slow in this respect. Since such systems are configured as loops or rings, if it is necessary to remove one of the processors, or as it is commonly referred to a node, from the loop or ring, this can only be effected by powering down the entire ring. In current systems, DMA transfers need to be sent around the entire ring thereby wasting bandwidth by transmitting past the targeted receiving node. Further, with the adoption of the PCI bus standards in PC technology, there exists a need in the art to support an effective distributed memory system.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a distributed memory system that will overcome the deficiencies and disadvantages of present known systems, and that will function more efficaciously and efficiently. Also, the present invention provides a novel printed circuit board that can be used in a system that includes PCI buses. The novel system of the present invention can be implemented in an electrical loop or ring or in an optical fiber loop or ring to achieve high performance and low latency by using master/master ring topology, up to 256 point-to-point flow controlled segments which can be configured to form an electrical ring up to 7.5 km in circumference or perimeter (100 feet between nodes, up to 256 nodes) or an optical ring about 750 km in circumference or perimeter. One of the principal advantages of the present invention is the ability to transfer simultaneously data from every node to traverse the entire ring (multipoint-to-multipoint). The 256 nodes are able to broadcast and receive at a given instance in time without tokens or data collisions in less than 300 microseconds. By the system of the present invention data transfers are obtainable of up to 1 Gigabaud per second with the lowest cost per connection thereby providing the capability of moving data at 100 MB per second using the fiber channel level 18b/10b coding scheme as known in the art.
The foregoing is accomplished by the present invention, in the development of a specific application of the invention by providing a unique PCI-Fiber Channel Memory Channel (PCI-FCMC) system for interconnecting standard 33 MHz PCI processor system buses to a serial Memory Channel. A novel PCI-FCMC board is provided as an element of the present invention which is a standard Type-5 form factor PCI card that occupies a single PCI slot in a standard type PC-style motherboard. The novel PCI-FCMC board provides the ability to share memory areas from within the on board memory area, from external to the board's memory area, along with the ability to provide a unique arbitration methodology. Some unique features of this novel and inventive board are a loop polling command, a DMA command queue, the ability to provide a dynamic insertion and removal of boards within an operating loop in the copper or fiber based buses without restarting the entire system, the ability to use DMA for memory areas reflected between two or more nodes, and the ability to stimulate `Mailbox style` interrupts through the Memory Channel bus. The inventive PCI-FCMC board acts in the system like a standard memory card. Different areas of the Memory array provide different functions which provide the unique variety of features provided by this invention as will become more evident from the following description of the preferred embodiment. The 64 or 128 MByte memory array within the board provides internal shared memory between systems. 4 KB areas, while they are mapped physically within the 64 or 128 MByte memory array, can provide a function of arbitration if a configuration bit is set. Additionally the board has the ability to provide DMA driven reflected memory from any portion of the remaining addressable area of memory within the system.
A data processing system has been created comprising, a plurality of nodes, a serial data bus interconnecting the nodes in series in a closed loop for passing address and data information, and at least one processing node including; a processor, a printed circuit board, a memory partitioned into a plurality of sections, a first section for directly sharable memory located on the printed circuit card, and a second section for block sharable memory, a local bus connecting the processor, the block sharable memory, and the printed circuit board, for transferring data in parallel from the processor to the directly sharable memory on the printed circuit board, and for transferring data from the block sharable memory to the printed circuit board, and the printed circuit board having; a sensor for sensing when data is transferred into the directly sharable memory, a queuing device for queuing the sensed data, a serializer for serializing the queued data, a transmitter for transmitting the serialized data onto the serial bus to next successive processing node, a receiver for receiving serialized data from next preceding processing node, and a deserializer for deserializing the received serialized data into parallel data.
A data processing system has been created comprising; a plurality of nodes, a serial data bus interconnecting the nodes in series in a closed loop for passing address and data information, and at least one processing node including; a processor, a printed circuit board, a memory for block sharable memory, a local bus connecting the block sharable memory and the printed circuit board, for transferring data from the block sharable memory to the printed circuit board; and the printed circuit board having; a memory moving device for reading data from the block sharable memory, a queuing device for queuing the read data, a serializer for serializing the queued data, a transmitter for transmitting the serialized data onto the serial bus to next successive processing node, a receiver for receiving serialized data from next preceding processing node, a deserializer for deserializing the received serialized data into parallel data.
A data processing system has been created comprising; a plurality of nodes, a serial data bus interconnecting the nodes in series in a closed loop for passing address and data information, and at least one processing node including; a processor, a printed circuit board, a memory for block sharable memory, a local bus connecting the block sharable memory and the printed circuit board, for transferring data from the block sharable memory to the printed circuit board, and the printed circuit board having; a node ID, a memory moving device for reading data from the block sharable memory, a tagging device for tagging the block transfer with a transfer tag and destination node ID tag, a queuing device for queuing the tagged data, a serializer for serializing the queued data, a transmitter for transmitting the serialized data onto the serial bus to next successive processing node, a receiver for receiving serialized data from next preceding processing node, a deserializer for deserializing the received serialized data into parallel data, a first sensor for detecting the transfer tag, a second sensor for sensing the destination tag within the parallel data, a comparator for comparing second sensed destination tag with the node destination ID, a routing device for steering the parallel data to the transmitter if the first sensor indicates the presence of the sensed tag and comparator is not true, and a second routing device for steering parallel data to the memory if the first sensor indicates the presence of the sensed tag and comparator is true.
A data processing system has been created comprising; a plurality of nodes, a serial data bus interconnecting the nodes in series in a closed loop for passing address and data information, and at least one processing node including; a processor, a printed circuit board, a memory for block sharable memory, a local bus connecting the block sharable memory and the printed circuit board, for transferring data from the block sharable memory to the printed circuit board, and the printed circuit board having; a node ID, a memory moving device for reading data from the block sharable memory, a tagging device for tagging the block transfer with a destination node ID tag, a queuing device for queuing the tagged data, a serializer for serializing the queued data, a transmitter for transmitting the serialized data onto the serial bus to next successive processing node, a receiver for receiving serialized data from next preceding processing node, a deserializer for deserializing the received serialized data into parallel data, a sensor for sensing the destination tag within the parallel data, a comparator for comparing sensed destination tag with the node destination ID, a routing device for steering the parallel data to the transmitter if the comparator is not true, and a second routing device for steering parallel data to the memory.
A data processing system has been created comprising; a plurality of nodes, a serial data bus interconnecting the nodes in series in a closed loop for passing address and data information, and at least one processing node including; a processor, a printed circuit board, a memory for block sharable memory, a local bus connecting the processor, the block sharable memory, and the printed circuit board, for transferring data from the processor to the printed circuit board and for transferring data from the block sharable memory to the printed circuit board, and the printed circuit board having; a memory moving device for reading data from the block sharable memory, a command queuing device for storing memory move command blocks from the processor, and a memory move controller including; a sensor to determine the availability of the memory moving device, a memory move command loader which unloads commands from the command queuing device and loads the commands into the memory moving device, a queuing device for queuing the read data, a serializer for serializing the queued data, and a transmitter for transmitting the serialized data onto the serial bus to next successive processing node.
A data processing system has been created comprising; a plurality of nodes, a serial data bus interconnecting the nodes in series in a closed loop for passing address and data information, and at least one processing node including; a processor, a printed circuit board, a sharable memory, a local bus connecting the memory to the processor for transferring data between the processor and the sharable memory, and the printed circuit board having; a mapping device for assignment of mailbox tag to specific address areas, a receiver for receiving serialized data from next preceding processing node, a deserializer for deserializing the received serialized data into parallel data, a decoder for decoding the address from the deserialized parallel data of the mapping device, a sensor for detecting the decoded mailbox tag, and an interrupting device for interrupting the processor upon sensing of the mailbox tag.
A data processing system has been created comprising; a plurality of nodes, a serial data bus interconnecting the nodes in series in a closed loop for passing address and data information, and at least one processing node including; a processor, a printed circuit board, a sharable memory, a local bus connecting the memory to the processor for transferring data between the processor and the sharable memory, and the printed circuit board having; a node ID, a group of node specific information, a tagging device for tagging the node specific information with a poll tag and a destination node ID tag, a poll initiator for reading node specific information on the printed circuit board upon a prompt from the processor, a transmitter for transmitting the node specific information onto the serial bus to next successive processing node, a receiver for receiving the node specific information from next preceding processing node, a first sensor for detecting the poll tag, a second sensor for detecting destination tag, a comparator for comparing sensed destination tag with the node destination ID, and a passing device including: a first routing device for steering the node specific information to the transmitter if the first sensor detects the poll tag and the comparator is false, an appending means for appending local node specific information onto the first routed data, the transmitter for transmitting the new set of node specific information onto the serial bus to next successive processing node, and a second routing device for steering the node specific information to the memory is the first sensor detects the poll tag and the comparator is true.
A method of providing for the arbitration for resources in a system has been described, made up of a set of elements, with a ring structure comprising the steps of; allocating a unique shared memory location for each the element involved in the arbitration, determining that none of the elements owns the resource, initiating of the request for the arbitration for the resource, determining that the request has circulated around the ring, re-examining of all the elements, determining whether another element is also requesting the resource, releasing the arbitration for the resource in response to a determination that another element is also requesting the resource, winning the resource in response to determination that no other element is requesting for the resource, and using the resource.
The foregoing features and advantages of the present invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING
FIG. 1 is a block diagram showing the novel inventive system and board.
FIG. 2 is a block diagram showing the details of internal operation of one of the field programmable ate arrays included on the board.
FIG. 3 is a block diagram showing the details of internal operation of the other field programmable gate arrays included on the board.
FIG. 4 is a block diagram showing an alternative bus structure using electrical rather than optical elements.
FIG. 5 a more generalized block diagram showing the system of the present invention.
FIG. 6 is a state diagram showing the local bus arbitration state machine function of the local bus state machine incorporated on the board of FIG. 1.
FIG. 7 is a state diagram showing the down state machine function of the local bus state machine incorporated on the board of FIG. 1.
FIG. 8 is a state diagram showing the DMA program state machine function of the local bus state machine incorporated on the board of FIG. 1.
FIG. 9 is a state diagram showing the up FIFO state machine function of the local bus state machine incorporated on the board of FIG. 1.
FIG. 10 is a state diagram showing the memory controller state machine function of the DRAM Control incorporated on the board of FIG. 1.
FIG. 11 is a state diagram showing the receiver state machine function of the Receive Control incorporated on the board of FIG. 1.
FIG. 12 is a state diagram showing the TX arbitration state machine function of the loop control state machine incorporated on the board of FIG. 1.
FIG. 13 is a flow diagram showing the operation of the Spin Lock Allocation Procedure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 5, a network or ring is shown consisting of a collection of individual computers or nodes coupled by serial memory channel loop or ring 509, which may take the form of a pair of optical or electrical buses. As shown in FIG. 5, up to 256 nodes, only four of which are schematically illustrated and designated by the reference numerals 501, 502, 503, and 504, can be serially connected. In the optical implementation, the interconnected nodes are coupled serially by single mode optical fibers 505 and Multimode optical Fibers 506, for data and flow control, respectively. Each node, as shown in FIG. 5, is an individual computer containing at a minimum a standard 33 MHz PCI system bus 50, and a CPU 510, a memory 511, and an I/O 512 all coupled to the bus 50. In particular, the CPU 510 has CPU memory 518 connected to the CPU by a private memory bus 514 which also connects via PCI Bridge chip 516 to the PCI bus 50. In addition, a fiber channel memory channel board 500 connects the PCI system bus 50 to the serial memory channel loop 509. Each node is provided with its own 8-bit Node ID. Although up to 256 nodes are described herein as individual computers, some or all of them can be interconnected in other supplementary known ways without departing from the teachings of the present invention. Each node essentially comprises what is known in the art as a personal computer or server. At a minimum, each node can consist of board 500, PCI bus 50 and one of the CPU 510, an input only I/O function, or an output only I/O function 512. Additionally, each node can contain a switch mechanism 519. This mechanism provides for a feed through path 553 for the single mode fiber, and 552 for the multimode fiber. It also provides the alternative paths 551 for the single mode fiber connecting single mode fiber optic cable 505 to cable 507, and 554 for the multimode fiber connecting multimode fiber optic cable 506 to cable 508.
Referring to FIG. 1, the fiber channel memory channel board 500 will now be described in detail. As already mentioned, board 500 provides an interconnection or data pathway between the PCI system bus 50 to serial loop 509. Board 500 is a standard Type-5 form-factor PCI card that occupies a single PCI slot in a standard type PC-style motherboard (not shown). Board 500 is provided with optical transceiver 34 which is connected to single mode optical fibers 507 and Pin Diode 38 and LED Transmitter 30, which is connected to multimode optical fibers 508. Optical transceiver 34 is connected to Receive Deserializer 31 via bus 86 and to Transmit Serializer 32 via bus 87. Fiber channel encoder/Decoder (ENDEC) 28 is connected to Receive Deserializer 31 via HREC -- CHAR -- INPUT bus 83 and to Transmit Serializer 32 via HTRANS -- CHAR -- OUT bus 84. ENDEC 28, for example, model VSC7107QC from Vitesse Semiconductor Corp., is connected via 32 bit Dec-Data bus 76 to 2 KW deep RX-FIFO 25 which in turn is connected to Fiber Channel Data Path FPGA 200 via 32 bit DFDATA bus 71. FPGA 200 provides data paths, staging registers, register file, multiplexors and comparators. ENDEC 28 is also connected to FPGA 200 via 36 bit EN-Data bus 72. ENDEC 28 connects to decode control Receive Decode C-PLD 27, a programmable logic device, via HERRBUS 80 and HDEC -- CMND bus 79 and also is connected to Loop Control State Machine C-PLD (LCSM) 26 via HEN -- CMND bus 75. FPGA 200 is connected to RX Window RAM 23 via buses WMD bus 69 and WADDR bus 70. FPGA 200 is also connected to 36 bit PCI DOWN FIFO 15 via bus 65 and to 36 bit PCI Up-FIFO 16 via bus 66. Loop Control State Machine 26 is connected to ENDEC 28 via bus 75 and FPGA 200 via Data Flow Control bus 73 and ID Comp bus 67. Also, Loop Control State Machine 26 is connected to Quantizer Receive Amplifier 29 by bus 74 and to Type FIFO 17 by bus 68. Quantizer Receive Amplifier 29 is a Quantizer/amplifier, well known in the optical fiber art, and is the interface used when using a pin diode as a receiver. Quantizer Receive Amplifier 29 is a full function receiver in which all components are integrated together in a known manner. Quantizer Receive Amplifier 29 is connected via bus 85 to pin diode receiver Pin RX 33 which receives multimode fiber flow control via bus 506, to provide messaging from a downstream node to its associated upstream node indicating that its FIFOs are full and to temporarily stop transmission.
Decode control 27 is connected by bus 81 to LED transmitter 30 which feeds multimode fiber flow control via bus 506. Control 27 is also connected to Type FIFO 24 via bus 78, which in turn is connected to the Loop Control State Machine 26 via bus 77. The bidirectional FIFOs 15, 16, and 17 divide board 500 into two sections as indicated by dotted line 11. The section portrayed above the dotted line 11 in FIG. 1 is the Serial interface, see legend, and the lower section portrayed below the dotted line 11 is the PCI interface, see legend.
PC DOWN FIFO 15, PCI Up-FIFO 16, and DMA Command FIFO 14 are all connected to AD -- FIFO -- PIN bus 64 which in turn is connected to Local Bus FPGA 100. FPGA 100 is connected to DPOST -- PIN bus 58 which in turn is connected to DRAM Control 18 and to odd and even registers 20. Odd and even registers 20 are connected to DRAM banks 21 via even bus 59 and odd bus 60. DRAM Control 18 is connected to DRAM Bank 21 via bus 61, buffer 19 and bus 62. Type FIFO 17 is connected to Local Bus State Machine 13 via bus 63. FPGA 100 provides data paths, staging registers, multiplexors and address decoders.
FPGA 100 is connected to TX Window RAM 22 via buses WRAM -- OUT bus 56 and WRAM -- PIN bus 57. PCI Interface chip (Obtainable from PLX Technologies, Model PLX9060) 10 a conventional PCI bridge, is connected to FPGA 100 via 32 bit LAD bus 51. PCI Interface 10 is also connected to Configuration EPROM 11 via bus 52, Local Bus State Machine 13 via bus 53 and to PCI bus 50 via the usual connectors generally designated as 49. EPROM 11 contains the basic configuration of the PCI interface 10 so a bus master can interrogate. The PCI 10, when powered up, fetches information from the EPROM 11 and puts the data in its internal registers to be available on system interrogation. Local Bus State Machine 13 is connected to FPGA 100 via Data Flow Control bus 55. Loop ID Jumpers 12, which contain the node address of the associated node only, is connected to the Local Bus State Machine 13 via bus 54.
The FPGA 100 and 200 are field programmable gate arrays, known in the art are obtainable from Lucent Technologies, model number OR2C15A-4S B352. Their programmed state, according to the present invention, is shown in FIGS. 3 and 2, respectively. Referring now to FIG. 3, the FPGA 100 will be described in detail. This chip is programmed to contain registers BREG 117 and CREG 118 which both receive input from PCI Interface chip 10 via bus 165, bus 151 (active low byte enable control bits LBE 3:0) and bus 164 (parity bits 3:0). Bus 151 also connects to AREG 101. AMUX 115 is connected to FREG 116 by bus 171. CREG 118 is connected to BMUX 105 via bus 157 which also connects to Address Decode 119, TX Window RAM 22 (bits 29:0 to junction point 172 and thereafter bits 29:12), and CMUX 110 from junction point 173 to transmit address. GREG 111 is directly connected to CMUX 110 and also is connected to DRAM Banks 21 via bus 156 which also connects to AMUX 115 to forward RAM data. EREG 104 is connected to BMUX 105 and also via bus 150 to FIFOs 15 and 16, DMA Command FIFO 14 and AREG 101 and DREG 102 and DMA Type 103 and DMA Uadd 106 which handles the 8 bit upper address 39-32. DMA Uadd 106 is connected to BMUX 105 via bus 158. AREG 101 connects to Address Decoder 107 via bus 152 which also connects to AMUX 115 and CMUX 110 to provide address and down address, respectively. DREG 102 connects via bus 153 to AMUX 115, CMUX 110, to provide data and down data, respectively. Status 108 is sourced by DMA Count 120 via bus 174 and other singular sources. MBOX DECODE 112 is connected to bus 152 and to AMUX 115. Bus 154 connects BMUX 105 to REG 109 and Config 113 and DCDAdd 114 which in turn connect to AMUX 115 by buses 162 and 163. Bits 7:0 from bus 57 and LBE 3:0 from bus 157 are connected to BMUX by bus 155. Bits 31:12 from bus 57 and bits 11:0 from bus 157 connect to BMUX by bus 174. WRAM READ Bus 161 connects AMUX 115 to TX Window Ram 22 to furnish WRAM data. WRAM PROGRAM bus 188 interconnects data bus 159 to TX Window RAM 22. Status 108 connects via bus 160 to AMUX 115. REG 109 is connected to BREG 117 and CMUX 110 furnishing data via bus 159. The coupling of the FPGA 100 to the DMA COMMAND FIFO 14, FIFOs 15 and 16, Type FIFO 17, Local Bus State Machine 13, DRAM Banks memory 21, DRAM control 18 (a Lattice PAL device), the TX Window RAM 22 and the PCI Interface 10 is shown in FIG. 3.
As shown in FIG. 3, TX Window RAM 22 is provided with map block context bits spin, loop, hit and RES which correspond to bit positions 40-43, respectively of the word format. Also, Address Decode 107 generates two unitary control bits, namely, local and out-of-range. Address Decode 119 generates 4 encoded bits to the Local Bus State Machine via bus 175.
Referring now to FIG. 2, the FPGA 200 will be described in detail. The chip is programmed to couple with the up/down FIFOs 15 and 16 via bus 265 and buffer 223, which couples to JREG 220 which couples to GMUX 219 via bus 263. Branching off bus 265 is buffer 224 which connects to bus 266 leading to CFG/STAT REGISTERS, CNT/Counters 221 and KREG hld 222. RX FIFO 25 couples to the chip via DFDATA bus 250 (bits 35..00) through buffer 204 to DMUX 205 directly connected to HREG 206. PL bus 254 (bits 35..0) feeds from the upstream side of IREG 208 which receives via END bus 255 (bits 35..0) from FMUX 209. IREG 208 feeds buffer 207 which outputs on EN -- DATA bus 275 (bits 35..0). The downstream side of HREG 206 is connected to Register File 213 via RFI bus 253 (bits 31..0). Bus 253 also connects to REG 203 for bits 7..0 to TX ID Hold 210 for bits 19..12, to Comp Ids 214 for bits 19..12 and to EMUX 212 for bits 31..12. REG 203 connects to REG 202 and then to Comp Seg 201 bits 39:32 via bus 257. TX ID Hold 210 connects to FMUX 209 via bus 256 for bits 19..12. EMUX 212 is coupled to REG 211 or bits 31..12 and the downstream side of REG 211 is coupled to Comp SEG 201 via bus 252 for bits 31:30, and to buffer 215 which is coupled to RX Window RAM 23 which generates offset addresses and context bits MBOX (bit 30) and RES (bit 31). RAM 23 is connected by WIND bus 60 and 258 (bits 31..0) to buffers 216 and 217, the latter connected to REG 218 for Bits (31..0) via bus 260. REG 218 is connected to GMUX 219 via WRD bus 257 (31..0) and to Comp SEG 201 for bits 29..20. Register file 213 is connected to GMUX 219 by RFD bus 261(31..0) which also connects to BE/Parity Gen which in turn connects to GMUX 219 via bus 262. Bus 261 also connects to FMUX 209. UP Loop bus 259 is connected to buffer 216, FMUX 209, EMUX 212, Registers 221 and KREG hid 222. Bus 268 connects Comp Ids 214 to Loop ID Jumpers 12 and FMUX 209 Bits 19:12. Data flow control 73 is provided by the Loop Control State Machine 26 as indicated. Hit bit 276 generated by Comp SEG 201 is fed to LCSM 26. TYPE FIFO 24 sends CNT TYP bits to LCSM 26 on bus 77.
The function and purpose of the TYPE FIFO 17 will be apparent from the following table. ##STR1## Wherein MC-PPDMA bit 14 is used for Point-to-Multi-point DMA; LPOLL bit 13 is used for loop poll for identifying nodes during initialization; bit 12 is used for the loop up function where the data goes from the PCI bus 50 back to the PCI bus 50; P-PDMA bit 11 is used for Point-to-Point DMA; MBOX bit 10 is used for Mailbox; SPIN bit 9 is used for the spin lock function; FOK bit 8 is used to indicate a bad packet; and PCI -- CNT bits 7 to 0 constitute an eight bit count created by the state machine for up to 256 DMA transfers. Each count represents a single 32 bit entry. The loop functionality provides a way where by when data are written to the fiber optic link 509, they can be also copied out on another area of the PCI bus to provide a usable second copy of the data. The address of the alternate 4K region is provided by the RX Window RAM 23 as the packet is `looped back` from the transmit path onto the receive path back to the PCI bus. The FOK bit in the TYPE FIFO provides a mechanism to alert the serial section that a packet which is in the UP FIFO 16 is for some reason invalid. For example, this could be because during the block move of data that a non-present area of memory was addressed, or that a parity error occurred during the data phase of the transfer.
The Down Type bits of TYPE FIFO 24 are explained in the following table:
______________________________________ dtyp1 dtyp0 FOK______________________________________Data Frame 0 0Reserved 0 1 1=okLoop poll frame 1 0 0=badReserved 1 1______________________________________
FIGS. 6 to 12 show the various functions of the Local Bus State Machine 13, the DRAM Control 18, the Receive Decode 27 and the Loop Control State Machine 26. Referring to these figures the various functions will be described in detail.
Local Bus Arbitration State Machine (LBASM)--As shown in FIG. 6, the LBASM provides signals which initiate actions within the DMA Program State Machine (DPSM) FIG. 8, Down State Machine (DSM) FIG. 7, and the Up FIFO State Machine (UFSM) FIG. 9. Upon reset and in between actions, the LBASM resides in the Idle state (S0A). Upon detection of data in the PCI Down FIFO 15, the LBASM moves into the Down Data State (S7A), and signals the DSM. It stays in this state until the data movement is completed by the DSM described later. Upon completion, the state machine returns to the Idle State (S0A). If a valid command set is detected within the DMA Command FIFO 14, the state machine moves to the DMA Load State (S8A) and signals the DMA Program State Machine (DPSM). It stays in this state until the data movement is completed by the DPSM described later. Upon completion, the state machine returns to the Idle State (S0A). If DMA completion is detected, the LBASM moves to the DMA Done State (S9A). It then moves to the DMA 128 Read State (S10A) where it reads the status register from the PCI Interface chip 10. It then moves to the DMA 128 Write State (S11A) where it writes a value which clears the pending interrupt. If the `write external status location` option is enabled the state machine moves to the DMA DCD Address State (S12A) which sets up the external address in which the data are to be written. It then moves to the DMA DCD Data State (S13A) which provides the data to be written. The state machine stays in this state until the data are written into memory and returns to the Idle State (S0A). If the LBASM detects a direct slave or DMA request from the internal Local Bus 51, the state machine moved to the Wait for ADS state (S1A). From there if the ADS was due to a slave memory access, the state machine moves to the Decode state (S2A). Here it determines whether the access is a local memory read/write, or a config/WRAM read/write. If the transfer is a local memory read/write, the state machine moves to the Local Rd/Wr State (S3A) where it signals the Up FIFO State Machine (UFSM) to transition to (S1D). Upon completion of the transfer, the state machine moves to the Wait for ADS State (S1A) to wait for more data. If there is no more data, the state machine moves back to the Idle state (S0A). If when the state machine was in the Decode (S2A), the transfer was determined to be for the Config RAM or WRAM's, the state machine moves to the Config Busy State (S6A), and signals the UFSM to transition to (S11D). It stays in this state until the individual Read/Write cycle is completed, and then returns to the Wait for ADS State (S1A) to wait for more data. If there is no more data, the state machine moves back to the Idle state (S0A). If when the state machine is in the Wait for ADS State (S1A), and it is determined that the access is due to a DMA action, the state machine moves to the DMA Decode State (S4A) where it signals the UFSM to transition to (S9D). It then proceeds to the DMA Wr State (S5A) where the state machine waits for the completion of the transfer. Upon completion of the transfer, the state machine moves to the Wait for ADS State (S1A) to wait for more data. If there is no more data, the state machine moves back to the Idle state (S0A).
Down State Machine (DSM)--As show in FIG. 7, upon reset and in between actions, the DSM resides in the Park state (S0B). Upon detection of the signal from the LBASM, the state machine moves to the A out State (S1B) where it dequeues the address from the down FIFO 15. It then moves to the Register A state (S3B) where it stores the Address into the AREG 101 and dequeues the data from the PCI Down FIFO 15. It then moves to the Register D State (S7B) where it stores the Data argument into the DREG 102. The Address Decode 107 provides the discrimination between the internal and external address ranges. These data are then used to decide the next state. If the data are for PCI memory, the state machine moves to the ADS state (S6B) where it drives the ADS signal on the LAD bus (51). It then moves to the Wait for Ready state (S14B) while presenting the data on the LAD bus (51). When the Ready line is returned from the PCI Interface chip (10), the state machine moves to the Ready state (S10B). If there is more data, the state machine moves to the Wait for Ready state (S14B) to present the next word of data, or if this is the last word of data, it returns to the Park State (S0B). If the Address Decode 107 determines that the data are for the internal RAM, the state machine moves from (S7B) to the Valid State (S5B). It next moves to the Request State (S4B) where it requests the Internal SRAM resource. The State machine then moves to the Acknowledge state (S12B) where it waits for the indication that the resource has been granted. When the resource is granted, the state machine moves to the RAS/CAS state (S13B) where the data array is accessed, and then moves to the Precharge state (S9B). If there is more data to be written into the array, the state machine moves into the DTK state (S8B) where the memory array is accessed, and then it moves back to the Precharge state (S9B). If the last word of data has been moved, the state machine moves back to the Park state (S0B). Finally, if the data in the PCI down FIFO 15 for any reason is corrupted, the state machine moves from (S7B) to the Trash state (S2B) where it dequeues the data from the PCI down FIFO 15.
DMA Program State Machine (DPSM)--As show in FIG. 8, upon reset and in between actions, the DPSM resides in the Location 108 state (S0C). Upon detection of the signal from the LBASM, the DMA register within the PCI Interface chip 10 at location 108 is written. When the data are accepted, the state machine moves to the Location 104 state (S1C) and commences writing of that location. When those data are accepted, the state machine moves to the Location 10C state (S3C) and commences writing of that location. When those data are accepted, the state machine moves to Location 110 state (S7C). Depending on the function being performed, (DMA read or DMA write), the state machine moves to the DMA Read state (S5C) or DMA Write state (S6C) respectively, and writes the register. When those data are accepted, the state machine moves to Location 128 state (S4C) and writes the register to initiate the DMA action. When that datum is accepted, the state machine returns to the DMA Write state (S6C), and then proceeds to the Cycle Start (S2C). The state machine then proceeds to the Location 108 state (S0C) in preparation for the next DMA action.
Up FIFO State Machine (UFSM)--As show in FIG. 9, upon reset and in between actions, The UFSM resides in the Idle state (S0D). Upon detection of a signal from the LBASM indicating a Local Write, the state machine moves to the Local Write 1 state (S1D) where it loads the first address argument into the PCI Up FIFO 16. It next moves to the Local Write 2 state (S2D) where it loads the second address argument. If the transfer is a write, then it moves to the Local Write 3 state (S3D), then to the Local Write 4 State where it load the data argument into the PCI Up FIFO 16. It then waits for the memory acknowledgment indication at which time it moves to the Data Burst State (S5D) where it loads all remaining arguments into the PCI Up FIFO 16. When the last data argument has been loaded and acknowledged, the state machine moves back into the Idle state (S0D). Upon detection of a signal from the LBASM indicating a DMA Operation, the state machine moves to the DMA 1 st Write state (S9D) where it loads the first address argument into the PCI Up FIFO 16. It next moves to the Local Write 2 state (S2D) where it loads the second address argument. It moves to the Local Write 3 state (S3D), then to the Local Write 4 State where it loads the data argument into the PCI Up FIFO 16. It then waits for the memory acknowledgment indication at which time it moves to the Data Burst State (S5D) where it loads all remaining arguments into the PCI Up FIFO 16. When the last data argument has been loaded and acknowledged, the state machine moves back into the Idle state (S0D). Upon detection of a signal from the LBASM indicating a Local Read, the state machine moves to the Local Write 1 state (S1D) where it suppresses the Address load into the PCI Up FIFO. It then moves to the Local Write 2 state (S2D) again suppressing the load into the FIFO. It next moves to the Wait for Hmem Ack state (S6D) where it waits for the access to the Memory Array 21. When access is achieved, the state machine moves to the Give Data to LB Odd (S8D) or Give Data to LB Even (S7D), respectively, depending upon the address of the read transaction. If multiple arguments are requested, the state machine moves back and forth between the aforementioned states supplying all requested data. When all requested data are supplied, the state machine moves back to the Idle State (S0D). Upon detection of a signal from the LBASM indicating a Control Space access, the state machine moves to the Exp Space Rd/Wr Dec state (S11D). There it moves to the Exp Space Read state (S12D) if a read is indicated. If the Read is to an area other than the RX Window RAM, the state machine moves to the Wr Exp Data to LB state (S14D), where the data are received to be returned to the PCI Interface chip 10. The state machine then returns to the Idle state (S0D). If the Read is to the RX Window RAM area, then the state machine moves to the RX WRAM Read 1 state (S18D) where it writes the address to the mailbox register. It waits until the argument is taken by the serial section at which time it moves to the RX WRAM Read 2 state (S17D) where it waits for the data from the RX WRAM 23 is loaded into the mailbox register. When the data are returned, the state machine moves to the WR Exp Data to LB state (S14D), where the data are received to be returned to the PCI Interface chip (10). The state machine then returns to the Idle state (S0D). Upon detection of a signal from the LBASM indicating a Control Space access, the state machine moves to the Exp Space Rd/Wr Dec state (S11D). There it moves to the Exp Space Write state (S10D) if a write is indicated. From this state, if the write is to the RX Window RAM 23, then the address is written into the mailbox and the state machine moves to the RX WRAM Write state (S16D). There it writes the Data argument into the mailbox register, and when it is accepted, the state machine returns to the Idle State (S0D). From the (S10D) state, if the write is to the DMA Command FIFO 14, then the state machine moves to the Wr to DMA FIFO state (S20D) and strobes the data into the FIFO. It then returns to the Idle State (S0D). From the (S10D) state, if the write is to the Loop Poll Register, then the state machine moves to the Loop Poll 1 state (S22D) where it loads the first Address for the Loop Poll. It then moves to the Loop Poll 2 state (S21D) where it loads the second address into the PCI Up FIFO 16. It then moves to the Loop Poll Data state (S19D) where it loads the loop poll data into the PCI Up FIFO. The state machine then returns to IDLE state (S0D).
Receiver State Machine (RSM)--As shown in FIG. 11, upon reset and in between actions, the RSM resides in the Idle state (S0F). Upon detection of a start of frame indicating a configuration transfer, the state machine moves to the Load Offset 1 state (S1F) where it loads the fist offset argument. It then moves to the Load Offset 2 state (S2F) where it loads the second offset argument. It then moves the Load RXID Into Mbox state (S3F) where it loads the RX ID. It finally moves to the Wr Type Status state (S6F) where it stores status from the configuration frame. It then moves back to the Idle state (S0F). Upon detection of a start of frame indicating a data frame, the state machine moves to the Load Data Frame state (S4F) where it sequentially loads all arguments into the RX FIFO. When the last argument is loaded into the RX FIFO, the state machine moves to the Check CRC Wait State (S5F) where the CRC value is checked. It then moves back to the Idle state (S0F). If, at any time, the receiver goes out of sync, the state machine immediately moves to the No Sync State (S7F) where it remains until resynchronization is achieved at which time it moves to the Idle state (S0F).
TX Arbitration State Machine (TASM)--As shown in FIG. 12, upon reset and in between actions, the TASM resides in the Idle state (S0G). Upon detection of the mailbox signal from the PCI Up FIFO16, the state machine moves to Read Mbox state (S1G). There it determines whether the action is a RX Window RAM read or write while using the mailbox entry to address the RX Window RAM 23. If the action is a RX Window RAM read it moves to the WRAM Read State (S7G) and returns data to the PCI Down FIFO 15 mailbox. If the action is a write, it moves to the WRAM Write State (S8G) and writes the data in the PCI Up FIFO 16 mailbox into the RX Window RAM 23. From both of these states (S7G and S8G) the state machine moves directly back to the idle state (S0G). After the link goes into synchronization, the state machine moves to the Send Offset state (S2G). Here, it controls the unloading of the RX FIFO offsets and Node ID to the down stream node and transmits the information onto the link. After it unloads the last Offset argument, the state machine moves back to the Idle state (S0G). Upon detection of loop initialization, the state machine moves to the Get TX Loop ID state (S3G). It then receives and stores the upstream node ID and returns to the Idle state (S0G). Upon detection of data in the RX-FIFO 25, the state machine moves to the Pass Fiber Data State (S5G) where it shunts the data out of the RX-FIFO 25 to the Transmitter. It stays in this state until all the data in the block has been transmitted at which time it moves back to the Idle state (S0G). Upon detection of a valid message in the PCI Up FIFO 16, the state machine moves to the Send PCI Data state (S6G). Here it unloads all available messages into the transmitter. When the last message is unloaded, it moves back to the Idle state (S0G). If the receiver goes out of sync, the TASM will exit the Idle state (S0G) and move to the Loop Out Of Sync state (S9G) until the receiver regains synchronization.
Memory Controller State Machine (MCSM)--As shown in FIG. 10, while in reset the MCSM resides in state PUP (S0E). When the reset is removed the state machine moves, and in between actions, the RASM resides in the idle state (S15E). Upon detection of the signal from the UFSM or DSM, the state machine moves to the RAS state (S11E) where the row address is presented to the array. It next moves to the Dtack state (S8E) where the Column address is presented. From here, the state machine moves back to the RAS state if there are more memory requests available; it moves to the RAS Precharge state (S7E) if there are no memory requests or refresh requests; or it moves to the HID state (S13E) if there is a refresh request, and then to the Refresh #0 state (S5E). The Refresh #0 state (S5E) can also be entered from the Idle state (S15E), or from the RAS Precharge state (S7E) if there is a refresh request active. From there, the state machine moves to the Refresh #1 state (S1E), and then the Refresh Acknowledge state (S9E) before finally moving to the RAS Precharge state (S7E) and back to the Idle state (S15E).
Operational Description
The PCI-Fiber Channel Memory Channel (PCI-FCMC), board 500 (FIG. 5), connects the standard 33 MHz PCI system bus 50 to the Serial Memory Channel, loop 509. As noted, the PCI-FCMC board 500 is a standard Type-5 form factor PCI card that occupies a single PCI slot in a standard type PC-style motherboard. The PCI-FCMC board 500 provides the ability to reflect memory areas from within the on board memory area, from external to the boards memory area, along with the ability to provide a unique arbitration methodology. Some unique features of this board are a loop polling command, a DMA command queue, the ability to provide a dynamic insertion and removal of boards within an operating loop in the copper or fiber based buses without restarting the entire system, the ability to use DMA for memory areas reflected between two or more nodes, and the ability to stimulate `Mailbox style` interrupts through the reflecting memory serial loop 509. The PCI-FCMC board 500 acts in the system like a standard memory card. Different areas of the Memory array provide different functions which provide the unique variety of features provided by this invention and design. The memory is up to 128 MByte within the board and provides logical shared memory between systems (nodes); this area while it is mapped physically within the 128 Mbyte, can provide a function called `Spin Lock Allocation Procedure` (SLAP) if a map configuration bit is set. Additionally, the board 500 has the ability to provide DMA driven reflected memory from any portion of the remaining addressable area of memory within the system node.
In the PCI interface section of board 500, PCI interface chip 10 from PLX Technology Inc. Model number PCI9060 provides all communication between the board and the PCI Bus 50. This chip provides the mapping for the 128 Mbyte memory area on board. Additionally, it provides the DMA engine for the block moves of data from system memory into the board, along with moving data received from the link 509 to the off board memory, whenever receive data are outside the internal addressing range. The PCI interface chip 10 is initialized upon power-up with a series of default parameters from a dedicated configuration EPROM 11 through dedicated bus 52. These data provide initial default values to all registers along with providing unique individual data for each board 500. The communication path for board 500 to the rest of the board is through the LAD bus 51. Status information is presented to the Local Bus State Machine (LBSM)13 and control information is provided from the LBSM 13 to both the PLX chip 10, DMA Command FIFO 14, and Local Bus FPGA 100. The LBSM 13 provides all data path control to the Local Bus FPGA 100 along with providing all the loading control for the DMA Command FIFO 14 as well as providing the automatic loading of the DMA registers within the PCI Interface chip 10 from the DMA Command FIFO 14. During the programming of the DMA Command FIFO 14, the LBSM 13 routes the PCI writes to the input of the DMA Command FIFO 14. The data come from the LAD bus 51 into the Local Bus FPGA 100 on the data path 165 into CREG 118. They are then routed through BMUX 105 into EREG 104 which drives the data out of the Local Bus FPGA 100. The LBSM then drives the write signals to the DMA Command FIFO 14. DMA command frames must be loaded in sequence. If this is not done, a DMA sequence error is reported in the status register and the FIFO is reset. When the LBSM 13 determines that the DMA resources are available and the DMA Command FIFO contains a valid command set, it initiates a DMA Load/Start process. The LBSM 13 enables the first value from the DMA command. The data are driven onto the AD -- FIFO -- PIN bus 64 and into the Local Bus FPGA 100 on an internal bus 150. Part of the data are captured into the DMA type register 103. The lower 11 bits of the remaining data are captured in DREG 102 and routed through AMUX 115 into FREG 116. They are then driven out of the Local Bus FPGA 100 onto the LAD bus 51 back into the PCI interface chip 10. The LBSM 13 drives the register addressing information to the PCI Interface chip 10 along with the write strobe signals, writing the data into the byte count register. The next two arguments from the DMA Command FIFO 14, the source address and destination address, are written in their entirety to the appropriate register in the PCI interface chip 10. The fourth and final argument in the DMA initialization sequence writes a 16 bit argument for the upper address bits (39-32) and point-to-point address information for the serial packet into the internal register 106 in the Local Bus FPGA 100. After this operation, the LBSM 13 writes to the PCI interface chip 10 to initiate the DMA operation. The registers within the PCI interface chip 10 provide PCI bus memory offset and magnitude. Internally, the external address is translated to a base address of 00000000h.
When a memory access is initiated on the PCI bus 50, the PCI interface chip 10 calculates whether the address falls within the range as defined by the configuration registers. Memory writes that are mapped into local memory from the PCI Bus 50 are moved from the PCI bridge 10 onto the LAD bus 51. The Address is captured first in the CREG 118 and routed through the CMUX 110 to the Greg 111. They are next routed out on the DPOST -- PIN bus 58 to the DRAM control pal 18. The DRAM control pal formats the address and creates the Row and Column address strobes. The multiplexed address signals are driven out of the DRAM control pal 18 on the HDRAMADD bus 61 to the address buffer 19, and then out the HSIMADD bus 62 to the DRAM 21. The data are driven from the LAD bus 51 to the internal bus 165 in the Local Bus FPGA 100 and captured in the BREG 117. It is then routed through CMUX 110 and captured in Greg 111. Next it is captured by either the even or odd data register 20 after which it is written into the DRAM array 21. Simultaneously, to the aforementioned actions, the address is routed from internal address bus 157 through the BMUX 105 and captured in the EREG 104 in order to be written into the PCI Up FIFO 16. During the data phase, the data are routed though internal data bus 159 and BMUX 105 and captured in EREG 104 via Reg 109 and bus 154. It is then also forwarded into the PCI Up FIFO 16. All these actions are under control of the LBSM 13. Likewise, for memory reads mapped into local memory from the PCI Bus 50, the data are simply moved from the DRAM 21 through the odd or even data bus, 59 or 60, and captured by the data registers 20. From there the data are moved to the DPOST -- PIN bus 58 and into the Local Bus FPGA 100. Within the FPGA the data are driven onto the internal RAM data bus 156 and routed through the AMUX 115 and stored in the FREG 116. It is then driven out of the FREG 116 onto the internal LAD bus 165 out onto the LAD bus 51 and back to the PCI bridge 10.
When data are detected in the PCI Down FIFO 15, the LBSM 13 controls the removal and proper dispersal of data. The data can either be within the Local Addressing range or outside of it. When a not empty condition is detected in the PCI Down FIFO 15, the LBSM 13 enables the data onto the AD -- FIFO -- PIN bus 64. It is then driven into the Local Bus FPGA 100 onto internal bus 150 where it is stored in the AREG 101. The address is decoded to determine whether it is Local or not in the Address Decode logic 107. The LBSM 13 dequeues the next entry in the FIFO 15 and again drives it into the Local Bus FPGA 100 on the internal bus 150 and into the DREG 102. If the decode 107 determines that the address is local, the address bits are driven onto the Down Address bus 152 and the data are driven onto the Down Data bus 153, and they are sequentially routed through the CMUX 110 and stored in the Greg 111. The data are then output onto the DPOST -- PIN bus 58, first with the address information out to the DRAM Control Pal 18, then with the Data words into either the odd or even data registers 20. The DRAM Control Pal 18 then controls the writing of the data into the DRAM array 21.
In the serial interface section, the PCI-FCMC uses a standard Fiber Channel chip set 28, 31, 32 to provide high speed interconnect between systems. The Fiber Channel Physical Layers FC-0 and FC-1 (X3.230-1994) are used with a proprietary framing protocol and command and arbitration schemes. It contains a single jumper block. The serial logic consists of a Fiber Channel chip set 28, receive FIFO 25, control CPLDs 27, 26, serializer 32 and a deserializer 31, optionally, a channel equalizer, such as 402 as shown in FIG. 4, or optionally Fiber Optic Transmitter/Receiver 34 as show in FIG. 1. The serial logic has three main functions or modes of operation: pass, insert, and remove data packets. Pass mode represents data moving around the serial loop and to the PCI Bus. Insert mode represents data moving from the PCI Bus to the serial loop. Removal mode represents data which has passed around the ring being removed by the last node which receives it. These three modes are controlled automatically by the loop arbitration logic 26.
PASS/REMOVAL MODES--In pass mode, a serial stream of 8b/10b encoded characters is received by the optical receiver 34. The data are passed on a serial bus 86 to the deserializer 31 which builds a 20 bit word and recovers the clock. These data are then passed to the Encoder/Decoder (ENDEC) 28 on the HREC -- CHAR -- INPUT bus 83. The ENDEC 28 assembles the 20-bit subwords into full 40-bit wide words that are then decoded into both command and data. The ENDEC 28 transmits the data on the DEC -- DATA bus 76 to the RX -- FIFO 25. The commands are sent to the DECODE C-PLD 27, converted into type, and written into TYPE FIFO 24. The Loop Control State Machine (LCSM) 26 detects the data in the RX-FIFO 25. The LCSM routes the data through the FC Data Path FPGA 200 buffers 204 through the DMUX 205 and latches it into HREG 206. This decoded 32 bit word is staged through two registers 203,202 to compare the segment address (bits 39-32) in the segment comparator 201. Simultaneously, the information is clocked into and staged through the Register File 213. The remaining portion of the address (bits 31-12) are sent through the EMUX 212 and staged through a register 211. These address bits are driven out the buffer 215 onto the WADDR bus 70 to the Receive Window Rams 23. The output of the Receive Window Rams 23 are driven over the WIND bus 69 back to the FPGA 200, and are received by an input buffer 217 and driven on an internal bus 260 to a register 218. If the Comparator 201 indicates a `hit`, the packet which has been staged through the register file 213 is directed on RFD 261 to the GMUX 219, with bits 12 through 31 of the address substituted from the window RAM 23 into the address to the GMUX 219. The original address is presented to the FMUX 209 simultaneously.
The output of GMUX 219 is routed to the DD bus 263 and staged into the JREG 220 to be driven out by the output buffers 223 to the PCI Down FIFOs 15. The output of FMUX 209 is driven on the END bus 255 and whether the data are clocked into the IREG 208 is dependent upon whether the Node ID compared to the ID comparator 214 was found to be equal to the settings of the Loop ID jumpers 12. If the comparison is NOT equal, the staged data stream from the register file 213 is driven on the RFD bus 261 to the FMUX 209 and via the END bus 255 to the IREG 208 and finally via the PL bus 254 to the output driver 207. From there, the data goes on the EN -- DATA bus 275 out to bus 72 into the ENDEC 28 where it is coded to 20 bit 8b/10b characters and then sent to the transmit serializer 32 and then through serial bus 87 out the optical transmitter 34. The LCSM 26 generates the command for a start-of-frame (SOF) to the ENDEC 28. Once the ENDEC 28 has acknowledged, the entire frame is read out of the RX-FIFO 25 into the ENDEC 28 while address/data from the frame are also written into the PCI Down FIFOs 15. At the end of the frame, the LCSM 26 generates an end-of-frame (EOF) command to the ENDEC 28, which causes CRC to be appended and the frame ended with an EOF. If the frame is to be terminated, the entire frame is still read out of the RX-FIFO 25 and written into the PCI Down FIFOs 15, but the ENDEC 28 remains off line and only transmits IDLE characters. The command and data sent to the ENDEC 28 is encoded in the 40-bit words that are output on the HTRANS -- CHAR -- OUT bus 84 to the transmit serializer 32 in 20-bit words, and sent on the serial bus 87 to the Fiber Optic Transmitter 34.
INSERT MODE--In Insert mode, the LCSM 26 reads the type through an internal bus 68 from the bi-directional TYPE FIFO 17 and determines the length and data type that is to be framed and sent out to the loop. The LCSM 26 generates the command for a Start of Frame (SOF) to the ENDEC 28. Once the ENDEC 28 has acknowledged, the LCSM reads the PCI Up FIFOs 16 building a frame to send to the ENDEC 28. The LCSM 26 continues to send sub-blocks from the PCI Up FIFOs 16 to the ENDEC 28 until the PCI Up FIFOs 16 are empty or the maximum sub-block count has been reached. In either case, the LCSM 26 generates an End of Frame (EOF) command to the ENDEC 28, which causes CRC (Cyclic Redundancy Check) to be appended and the frame end with an EOF. The command and data sent to the ENDEC 28 is encoded in the 40-bit words that are output on the HTRANS -- CHAR -- OUT bus 84 to the transmit serializer 32 in 20-bit words, and sent on the serial bus 87 to the Fiber Optic Transmitter 34.
SERIAL FRAMES--The PCI-FCMC frame consists of a Start of Frame (SOF) followed by one or more data sub-packets, and terminated with a CRC word and an End of Frame (EOF). Data sub-packets consist of two addresses and one or more data phases. The address phase contains 64 bits of information which is used to control the data flow. Table 1-2 shows the format of the address phase.
TABLE 1-2______________________________________Address Phase Sub-packet DescriptionBit Field Description______________________________________63-60 ByteEna Single bit codes that define valid bytes in the current data phase. These are high true and are defined as follows: Bit 63 -> byte 3 (bits 31-24) valid Bit 62 -> byte 2 (bits 23-16) valid Bit 61 -> byte 1 (bits 15-8) valid Bit 60 -> byte 0 (bits 7-0) valid59-52 Count The count of 32 bit data words that follow the address phase. PCI-FCMC only supports counts of 16 words or less.51-44 Node ID This field is the node ID or loop address of the node that removes the frame from the loop.43-41 Rsvd40 Point to Point DMA39-0 Address A 32-bit address Specifying the destination of the data (internal RAM or PCI bus)______________________________________
As is evident from the above, each sub-packet has a 64-bit address phase. The data path, however, is only 32 bits wide, so in order to transmit out a single address phase it takes two transfers (i.e., the first two transfers in the sub-packet are the 64 bit address phase).
With respect to the 0-39 bit address field containing designating the 32 bit address, the 32 bit address is mapped by the TX Window RAM 22 into a 40 bit address to be transmitted on the FCMC bus loop 509. This is accomplished by merging the original 12 lower bits (0 to 11) with a 28 bit output from the TX Window RAM 22 (into bits 12-39), and it is with this address that the transfer is placed on the bus. When the transfer is received, the top 10 bits of the address received from the FCMC bus loop 509 are compared with 10 bits from the RX Window RAM 23, and if they match then the data are saved again with the lower 12 bits of the address (0-11) being merged with 20 bits from the RX Window RAM 23 in bit positions 12 to 31. This forms the full receive 32-bit address.
Window RAM initialization--The Window RAM regions of the FCMC board 500 are mapped into the PCI memory space at FFEFFFFFH-FFE00000h for RX Window RAM 23 and FFDFFFFFh-FFD80000h for TX Window RAM 22. The process of programming the TX Window RAM 22 involves a write on the PCI bus 50 to the FFE00000h to FFEFFFFFh region. These addresses are recognized by the PLX PCI interface chip 10 and accepted. The address and data are placed on the LAD bus 51 which transmits the data to the Local Bus FPGA 100. Inside the Local Bus FPGA, the address bits are captured by the CREG 118 and driven onto the internal Address bus 157 out to the TX Window RAM 22. The next cycle the data, which are driven from the PLX PCI interface chip 10 through the LAD bus 51 to the Local Bus FPGA 100 are captured into the BREG 117. It is driven onto the internal Data bus 159 along the WRAM Program pathway to the TX Window Ram 22 via data lines 57. The data are then written into the TX Window RAM 22 by strobing their write enable lines. When the contents of the TX Window RAMs 22 are read, the address path is the same as the write. The data are then driven from the TX Window Rams 22 onto the WRAM-PIN bus 57 to the Local Bus FPGA 100. Inside the array, they are driven onto the Data bus 159 along the WRAM READ path to the AMUX 115 and registered into the FREG 116. From the FREG 116, the data are driven on the internal bus 165 out to the LAD bus 51 back to the PCI Interface 10.
The process of programming the RX Window RAM 23 involves a write on the PCI bus 50 to the FD800000h to FD8FFFFFh region. These addresses are recognized by the PCI interface chip 10 and accepted. The address and data are placed on the LAD bus 51 which transmits the data to the Local Bus FPGA 100. Inside the Local Bus FPGA, the data are captured by the CREG 118 and driven onto the internal Address bus 157 to the BMUX 105 and into the EREG 104. It is then driven out of the Local Bus FPGA into the PCI Up FIFO 16, bypass register. The address is removed from the FIFO and written into the KREG-36 hld (222). It is then driven on the UPLOOP bus to the EMUX and into the REG (211) and out through the output buffer (215) to the address lines of the RX Window RAM. After the address argument has been removed from the bypass register, the next cycle, data cycle, begins. The data are driven from the PLX PCI interface chip (10) through the LAD bus (51) to the Local Bus FPGA (100) is captured into the CREG-36 (118) and driven onto the internal Address bus (157) to the BMUX and into the EREG-36. It is then driven out of the Local Bus FPGA into the PCI Up FIFO (16) bypass register. The address is removed from the FIFO and written into the REG-36 hld (222). It is then driven on the UPLOOP bus to the output buffer (216) to the data lines of the RX Window RAM. The data are then written into the RX Window RAM. When the RX Window RAMs (22) are read, the address path is the same as the write. The data are driven from the RX Window RAMs on the WIND bus (69) to the FC Data Path FPGA. Inside the FC Data Path FPGA (200) it is driven through the input buffer (217) on a bus (260) into the REG (218). From the output of the REG (218), it is driven on the WRD bus (257) through the GMUX (219) into the JREG-36 (220). It is driven out of the JREG-36 (220) on a bus (264) to an output buffer (223). It is then written into the bypass register of the PCI Down FIFO (15) from which it is then driven into the DREG (102), through the AMUX 115 into the FREG 116. The data are driven onto the output bus 165 of the Local Bus FPGA 100 out the LAD bus 51 back to the PCI interface 10 returning the data onto the PCI bus 50.
The termination address is handled in one of three ways by the PCI-FCMC board 500. In the case of the normal transfer, the address is programmed with the address of the node just prior to the transmitting node. This address is acquired during the node initialization process where each node transmits its address to its nearest neighbor. In the case of the spin lock procedure, the address is programmed with the address of the transmitting node. Lastly, in the case of the point to point/multipoint protocol, the address is programmed with the address of the node to which the data are destined. In all the cases, the data are transmitted onto the link, and at each node, the address of the packet is compared with that of the Switch setting 12 (node ID) by the comparator 214, and if there is no match, the data are retransmitted out to the next link in the loop. When it finally gets to the node which has an address matching the address broadcast, that node removes the transfer from the loop.
THE POINT-TO-POINT DMA (PTP-DMA) protocol allows for the private passing of messages between two nodes attached to the loop 509. This is important in that this minimizes the traffic traveling around the FCMC ring 509 as it removes the transfer when it arrives at the destination instead of the transfer traversing the entire ring system. The PTP-DMA protocol essentially uses the following structures DMA FIFO 14, the Comp SEG 201, and the Compare Ids 214. The methodology is as follows. The DMA FIFO 14 contains the address of the node to which the data are destined along with the PIP-DMA context tag. This is the address of the node which will ultimately remove the data from the link as described in the UFSM (FIG. 9). The PTP-DMA context bit indicates to the receiver that the data is not to be stored at any intermediate node location. The programming of the DMA FIFO 14 involves the sequential loading of 4 arguments into the FIFO 14 from the PCI bus 10. The PCI Interface chip 10 detects a write to location FFF00000h. It accepts the transfer and places the write onto the LAD bus 51, first the address phase which is strobed into the CREG 118 and then the data phase which is strobed into the BREG 117. The address is decoded by the Address Decoder 119 which indicates that this argument is to be stored in the DMA Command FIFO 14. The data argument travels on the bus 159 to REG 109, and then to the BMUX 105. It then is latched into the EREG 104 and travels out the bus 150 to the AD -- FIFO -- PIN bus 64 where it is written the DMA Command FIFO 14. This first argument contains The DMA type and Transfer count. The next 3 arguments are loaded by PCI bus 50 writes to locations FFF00004h (32 bits of the Destination Address (lower portion)), FFF00008h (the Source Address), and FFF0000Ch (the upper 8 bits of the 40 bit address which is to be put out on the FCMC bus 509, the Point to Point Destination address and byte enables). The Unloading of the DMA Control FIFO 14 is described in the DPSM section. The first three entries from the DMA Command FIFO 14 are driven onto the AD -- FIFO -- PIN bus 64 into the Local Bus FPGA 100. Within this array, the data are driven on the 150 bus to the DREG 102. From there it is driven on the data bus 153 into the AMUX 115. Out of the AMUX 115 the data are driven on the bus 1271 into the FREG 116. The FREG 116 drives out the data bus 165 out of the FPGA to the LAD bus 51 to the PCI Interface chip 10. The Local Bus State Machine FPGA 13 drives the register addressing information to the PCI Interface chip 10 and strobes the write to the chip. The fourth entry is driven out of the DMA Command FIFO 14 onto the AD -- FIFO -- PIN bus 64 into the Local Bus FPGA 100. Within the array the data are driven on the 150 bus to the DMA Uadd register 106 where it is stored until the DMA operation is commenced.
When the DMA operation starts, the PCI Interface chip 10 starts reading the block of data from the PCI bus. The chip presents the address on the LAD bus 51 to the Local Bus FPGA 100, which drives it on its internal bus 165 to the CREG 118. The data are driven on the address bus 157 to the BMUX 105 to the EREG 104. There, the contents of the DMA Uadd 106 register is fist driven out on the AD -- FIFO -- PIN bus 64 and loaded into the PCI Up FIFO 16. Next the address in the EREG 104 is driven out on the AD -- FIFO -- PIN bus 64 and loaded into the PCI Up FIFO 16. The DMA operation follows the address cycle with a block read on the PCI bus 50. The PCI Interface chip 10 transfers those data to a series of writes on the LAD bus 51. Each data transferred on the bus is driven onto the internal data bus 165 of the Local Bus FPGA 100, and into the BREG 117. From there it is driven into the REG 109 from the 159 bus and out on to the 154 bus into the BMUX 105. From the BMUX 105 the data are stored in the EREG 104 and then driven out of the EREG 104 on the 150 bus to the AD -- FIFO -- PIN bus 64 and into the PCI Up FIFO 16. A counter within the Local Bus State Machine 13 counts each data entry and at the end of the transfer drives the transfer count on 63 bus into the Type FIFO 17 in order to transmit the word count to the serial section. The serial section transmits the data as described in the INSERT MODE section. When the packet is received by the next node in line, the packet is first loaded into the RX-FIFO 25. The packet is dequeued from the RX-FIFO 25 and the two address words are staged into the address staging registers 203, then 202 and 212 while the 8 bit nodal address information is sent to the Comp Ids comparator 214 and the PTP-DMA context bit is sent to the Receive Decode C-PLD 27. The output of the final staging registers are used to address the RX Window RAM 23. The data read from the RX Window RAM is driven onto the WIND bus 69 and received back into the FC Data Path FPGA 200 via bus 258. The Receivers (buffers) 217 drive the data on bus 260 to the REG 218 where it is stored. The state of the PIP-DMA context bit is used to decide whether to keep the data. If the decision is to keep the data, bit 19 through 0 from the REG 218 are merged into bit positions 31 through 12 respectively in GMUX 219 and bits 11 through 0 are read from the register file 213 and then bits 31 through 0 are all stored in the JREG 220 in preparation to be sent to the memory. Finally, if the result of the Comp Ids comparator 214 was false, the packet is reloaded out of the register file 213 back to the transmit path on the RFD bus 261 which routes the data through the FMUX 209, the IREG 208, and out the EN -- DATA bus 275 to be driven to the next node in the loop. If the result of the Comp Ids comparator 214 is true, the packet is not fed back to the transmitter.
The software protocol is as follows. The software functionality for the point to point protocol, involves the programming of the DMA Command FIFO 14 with the 4 arguments for the initialization of the DMA transfer. This is accomplished by a series of register writes to the PCI-FCMC 500. No other initialization is required.
THE POINT-TO-MULTI-POINT DMA (PTM-DMA) protocol allows for the private passing of messages between multiple nodes attached to the loop 509. This is important in that this minimizes the traffic traveling around the FCMC ring 509 as it removes the transfer when it arrives at the destination instead of the transfer traversing the entire ring system. The PTM-DMA protocol essentially uses the following structures DMA FIFO 14, the Comp SEG 201, and the Compare Ids 214. The methodology is as follows. The DMA FIFO 14 contains the address of the node to which the data are destined without the use of the PTP-DMA context tag. This is the address of the node which will ultimately remove the data from the link as described in the UFSM (FIG. 9). Without the PTP-DMA context bit to indicate to the receiver that the data is not to be stored, the data are stored at all intermediate node locations. All other aspects of the transmission of the PTM-DMA are identical to PTP-DMA described earlier. When the packet is received by the next node in line, the packet is first loaded into the RX-FIFO 25. The packet is dequeued from the RX-FIFO 25 and the two address words are staged into the address staging registers 203, then 202 and 212 while the 8 bit nodal address information is sent to the Comp Ids comparator 214. The output of the final staging registers are used to address the RX Window RAM 23. The data read from the RX Window RAM is driven onto the WIND bus 258 and received back into the FC Data Path FPGA 200. The Receivers (buffers) 217 drive the data on bus 260 to the REG 218 where it is stored. From the REG 218, bits 20 through 29 are driven back to the Comp SEG comparator 201 where the decision is made whether to keep the data. If the decision is to keep the data, bit 19 through 0 from the REG 218 are merged into bit positions 31 through 12 respectively in GMUX 219 and bits 11 through 0 are read from the register file 213 and then bits 31 through 0 are all stored in the JREG 220 in preparation to be sent to the memory. Finally, if the result of the Comp Ids comparator 214 was false, the packet is reloaded out of the register file 213 back to the transmit path on the RFD bus 261 which routes the data through the FMUX 209, the IREG 208, and out the EN -- DATA bus 275 to be driven to the next node in the loop. If the result of the Comp Ids comparator 214 is true, the packet is not fed back to the transmitter.
The software protocol is as follows. The software functionality for the point to multi-point protocol, involves the programming of the DMA Command FIFO 14 with the 4 arguments for the initialization of the DMA transfer. This is accomplished by a series of register writes to the PCI-FCMC 500. No other initialization is required.
SPIN LOCK ALLOCATION PROCEDURE (SLAP)--The SLAP is accomplished by a subtle variation on the shared memory procedure. As discussed in the Packet Termination Procedure (Non-SLPA), the loop address used to remove the packet from the link, in the case of the SLAP variant, is that of the node initiating the transfer. The write into memory is suppressed initially and is only written when the transfer travels completely around the loop and is returned to the initiating node. This guarantees, if one reads the location to be written and sees that the data has been written, and if one reads the location dedicated to any other node and that location has not been written (should an other node be writing its dedicated location at ANY point in time, it would necessarily see BOTH the write to its location AND the write to this nodes location), then this node wins the allocation procedure.
The SLAP variant allows for the rapid arbitration for data between independent computers. The coordination of these rapidly shared data, however, involves a unique design problem that is solved by the present invention. In order to control the use of these data, control locations are defined and arbitrated between each of the nodes. In other words, one must know whether a resource can be used by a node, and that information is provided by the contents of designated areas, within the on-board Memory, for which it can be arbitrated in an unambiguous way.
A methodology was created which can insure the reliable arbitration of these shared resources to insure that when several nodes are competing for a resource, only one is granted the resource. This methodology according to the present invention uses a software spin lock along with a hardware protocol to insure the unique granting of the resource to a single node. This Spin Lock Allocation Procedure (SLAP), according to the present invention, is part of Fiber Channel Reflective Memory System (FCRMS) previously described. The PCI-FCMC is a collection of point to point connections which when taken together create a logical loop. Information is passed from one node to the next until it moves completely around the loop. It is in this environment in which the SLAP was created to provide a method whereby two nodes could, upon simultaneous request for a resource, distinguish who was given the resource and who was not.
The way in which this problem is solved according to the present invention is to map a number of unique areas equivalent to the number of nodes. This technique creates a shared memory resource, the size of which is dependent upon the number of nodes involved in the arbitration. Each area is mapped to be written by only one of the arbitrating nodes. This insures that there are no conflicts in usage of each memory area between nodes. Each node is able to read all the memory areas for all the nodes.
The hardware protocol of the SLAP on the PCI-FCMC works as a variant of a normal write transfer in the Memory System. In a normal transfer, when a piece of data is written in to a local memory destined to be shared, those data are first written locally, then placed upon the link, and thus, written into the memory of any other nodes sharing these data. The data are removed from the loop prior to it being returned to the initiating node. In the case of the SLAP variant of the shared memory operation, the area is created with subsections which are assigned uniquely to any node which needs to arbitrate for the shared resource. At the beginning of the arbitration, this area is tested to determine whether the resource is presently in use. If not, a request is generated, but not written into local memory. It is only placed on the loop. The transfer is passed around the ring to each node which in turn, if involved in the arbitration, must write the request value into that node's memory. The transfer lastly arrives back at the originating node (it is not stripped by the prior node, but by the originating node), and is finally written into the memory of the originating node. Another variant of this procedure could be accomplished by initially writing to a "shadow" in memory. The transfer, when it is receive into each of the nodes is offset into a different memory area. This different memory area is then read at this other location looking for the arrival of the data around the loop.
FIG. 13 represents the flow of the software using of the spin lock feature. The variable `x` represents the number of nodes participating in the spin lock arbitration. The `y` variable represents the relative position of this participating node. The first operation is to set the `x` variable to zero (1H). Each location representing an arbitrating node is read in sequence and checked for active arbitration (2H,3H,4H, and 5H). If there exists an active request, the software exits and rearbitrates (50H). If there are not active requesters, the software moves to begin its own request (51H). The software writes a request to its designated location (6H). It then scans that location until it reads the just written data indicating (7H and 8H) the transfer has gone completely around the loop. Next the `x` variable is reset to zero (9H). Each location representing an arbitrating node is reread in sequence and checked for active arbitration (10H, 11H, 12H, and 13H). If this requesting node is the only requesting node, the software wins (53H) the arbitration (17H). If other nodes are requesting, the software moves (54H) to clear its request (14H, 15H, and 16H), and then moves (55H) to retry the arbitration after a random wait period (18H) to avoid deadlock.
Shared memory systems previously known allow for the rapid exchange of data between independent computers. The accomplishment of this exchange has been implemented in several ways. When a parallel multidrop bus was used, nodes could be powered-down/removed or powered-up/added without disturbing the network. With the advent of the serial loop implementation, the insertion or extraction of a node now had the effect of disrupting the network. Because of the necessity of providing reliable communication between nodes at all times, the present invention provides ring healing in a new and unique way.
ENCORE ADAPTIVE RING-HEALING (EAR)--A variant in the ring structure allows for the use of a balanced Electrical interface for the ring element rather than the Fiber Optic element in the preceding detailed description of a preferred embodiment. This variation, as illustrated in FIG. 4, substitutes Electrical Driving and Receiving elements for the Fiber optic elements. An important characteristic of this design is the `Isolated healing element` (IHE, 403). This element allows for the removal and insertion of a node while the ring is up and functioning. Variants of this design would provide dual redundant power to the IHE 403, or allow that the IHE 403 be a stand alone plug-able element to which the node is attached for the ring element rather than the Fiber Optic element in the preceding example.
The methodology according to the present invention provides an adaptive ring-healing (EAR) which utilizes a hardware switch controlled by a `power good` indication, and a protocol initiating a complete ring resynchronization upon detection of the link event. The problem involves providing an solution for the case where nodes, potentially at their extreme separation from each other, fail. If the solution were simply to multiplex the data through the node, then the resultant ring repair would provide an unreliable connection. This would limit the length of the node to node runs to a sub-multiple of the maximum length of the run, with the divisor being the maximum number of failing nodes. This limitation would obviously severely limit the useful length of the link. It was thus necessary to come up with a technique which would allow the use of maximum length point to point connections.
The structure of the EAR involves the use of a multiplexing device in the data path between the output of the serializing/deserializing devices and the driver/equalizer. The device provides a direct path from the output serializing device and the output driver/equalizer. It also has a tap from the output of the receiver/equalizer. This tap is fed into the second port of the multiplexor. This multiplexor is unique in that it provides a resynchronization on the second port of the multiplexing device. The solution afforded by the present invention is unique in that the resynchronization port is employed as a technique to synchronize an asynchronous device to the synchronous bus. In the case of the present invention, each point to point connection is treated as an asynchronous connection and the device is run synchronously with the source of the signal. In this way, the part, when in bypass mode, acts as a resyncing repeater, and thus, allows for no reduction of internodal distance.
The hardware protocol involves the sensing of the existence of good power to the interface. If the power good indication goes away, a signal is sent to the interface causing a switch of the interface from participating mode to bypass mode. This switch causes a perturbation on the link causing a `loss of sync` from the receiving chipset.
Software Protocol involves the sensing of the `loss of sync` signal from the chipset. When this condition is detected, the node transmits out a message to `take down the link`. When all the nodes on the link are brought down, the link resync/recovery procedure begins. The link resync/recovery procedures needs to handle two distinct uses of "global memory". The first involves using the memory for global shared resources, and the second is for communication.
Global shared resources are always protected with a spin lock. If a loss of sync is detected the "owner" of the shared resource is responsible for refreshing everyone on the ring. If no one owns the spin lock at the time of the failure, then the resource is up to date on all the nodes and refresh is unnecessary. Because of the algorithm used for attaining a spin lock, it is impossible to become the owner of a shared resource while a "loss of sync" condition exists.
Communication between nodes always involves a request, followed by a response that the request is complete. Should a "loss of sync" condition be detected before the final response is received, all requests are retransmitted when the error state is remedied. Because of the serial nature of the ring it is inherent that when a response packet is received, all data for the request has also been received.
LOOP POLLING--The operation of Loop Pooling involves writing to a region which starts the Loop Poll Command (LPC). Upon receipt of this command the serial hardware initiates a special frame that contains his Node ID. This frame is sent around the loop where each node appends his own Node ID and Type as an additional 32-bit word. Each node will insert his 8-bit node ID into bits 19-12 of a 32-bit word and the Type will be inserted into bits 7-0. All remaining bits in each nodes' 32-bit word will be set to zero. When the Frame loops back to the originating node, the entire list is written to the destination address. The Programmer must mask (write all ones) to a buffer of 256 Double-Words in local (CPU) memory or in the local memory of the Originating node to be able to recognize the end of the Loop Node-ID List. When writing to this address, the data phase must contain the destination address of the destination buffer.
MAILBOX INTERRUPT OPERATION--The operation of the Mailbox interrupt is controlled by the initialization of location within the RX Window RAM with the Mailbox context bit. The programming of the RX Window RAM is described earlier. When the packet is received by the node, the packet is first loaded into the RX-FIFO 25. The packet is dequeued from the RX-FIFO 25 and the two address words are staged into the address staging registers 203, then 202 and 212 while the 8 bit nodal address information is sent to the Comp Ids comparator 214. The output of the final staging registers are used to address the RX Window RAM 23. The data read from the RX Window RAM is driven onto the WIND bus 258 and received back into the FC Data Path FPGA 200. One bit of those data is the Mailbox context bit. If this bit is set in the entry addressed by the incoming packet, this context is written into the type FIFO 17. After the data associated with the transfer are removed from the PCI Down FIFO 15 and written into memory, a PCI interrupt command is written into the PCI Interface chip 10, initiating a PCI bus 50 interrupt.
LOOP DATA FLOW OPERATION--After a power up reset or when a node switches loop back modes, the loop toggles from a non-synchronized mode to a synchronized mode. Immediately after loop synchronization, each node transmits an initialization frame to the next node in the loop. This frame contains the source node ID that was stored in the transmitting node, thus allowing every node to recognize the ID of the node transmitting to it. This loop initialization scheme gives each node the ability to determine when a data frame has completed the loop and is to be terminated, or when it is to be retransmitted to the next node in the loop.
The following is an example of normal loop transfer:
1. Node 2 receives Node 1's loop ID during the Loop initialization procedure
2. Node 2 receives some local writes in its memory space.
3. Node 2 builds a packet with Node 1's loop ID in the address phase 1 of all the sub-frames to be transmitted out to the loop.
4. Once step 2 is completed and Node N begins receiving the frame, Node N compares the source loop node ID from address phase 1 of the incoming frame to its own loop ID. As node 2 inserted Node 1's loop ID, no match occurs and Node N retransmits the frame to the next node in the loop (Node 1).
5. When Node 1 receives the frame a match occurs and Node 1 terminates the loop transfer.
The following is an example of a normal spin lock loop transfer:
1. Node 2 receives some local writes to its memory space defined as spin lock, but suppresses the actual write into its memory.
2. Node 2 builds a packet with its own loop ID in the address phase 1 of the sub-frames of the spin lock transfer. This prevents any node in the loop from terminating the spin lock loop transfer as it circles the loop.
3. Once the loop transfer returns to Node 2, a loop ID match occurs and Node 2 terminates the loop transfer. At that time, the data are written into the local memory.
Although the invention has been shown and described in terms of a preferred embodiment, nevertheless changes and modifications are possible which do not depart from the spirit, scope and teachings of the invention. Such changes and modifications are deemed to fall within the purview of the invention and the appended claims.
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A data processing system includes a plurality of nodes, a serial data bus interconnecting the nodes in series in a closed loop for passing address and data information, and at least one processing node. In one construction, this processing node has a processor, a printed circuit board, a memory partitioned into first and second sections and a local bus connecting the processor, a block sharable memory section of the memory, and the printed circuit board. The local bus is used for transferring data in parallel from the processor to a directly sharable memory section of the memory on the printed circuit board and for transferring data from the block sharable memory to the printed circuit board. The printed circuit board includes a sensor for sensing when data is transferred into the directly sharable memory, a queuing device for queuing the sensed data, a serializer for serializing the queued data, a transmitter for transmitting the serialized data onto the serial data bus to the next successive processing node, a receiver for receiving serialized data from next preceding processing node, and a deserializer for deserializing the received serialized data into parallel data.
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FIELD OF THE INVENTION
[0001] The invention relates to the field of the soft hydrocracking of hydrocarbons (“mild hydrocracking,” in English). The invention consists in optimizing the thermal integrations between the hot and cold streams of the unit so as to reduce the consumption of hot and cold utilities, and, as a result, the greenhouse gas (GHG) emissions.
[0002] This invention can be viewed as an enhancement of the application filed on Dec. 18, 2012 under No. FR 12/03,469.
EXAMINATION OF THE PRIOR ART
[0003] The prior art is shown by the diagram of FIG. 1 that will be described in detail in the paragraph “detailed description of the invention.”
SUMMARY DESCRIPTION OF THE FIGURES
[0004] FIG. 1 shows the thermal integrations of a mild hydrocracking process according to the prior art.
[0005] FIG. 2 shows the new thermal integrations of the mild hydrocracking process according to the invention.
SUMMARY DESCRIPTION OF THE INVENTION
[0006] This invention describes a process for mild hydrocracking of a fraction of the vacuum distillate (DSV or “VGO” in English) type or the deasphalted oil (DAO) type for the purpose of constituting the feedstock of a catalytic cracking unit, comprising:
A mild hydrocracking zone R, A high-pressure hot separator tank B- 1 , whose feedstock constitutes the effluent obtained from R, A high-pressure cold separator tank B- 2 , whose feedstock constitutes the gas stream obtained from B- 1 , A low-pressure cold separator tank B- 3 , whose feedstock is the liquid stream obtained from B- 2 , A zone K for washing with an amine and for compression of the gaseous effluent obtained from B- 2 , called recycled hydrogen, A pump P- 2 compressing the VGO feedstock before mixing with the recycled hydrogen obtained from K and the addition of hydrogen, A stripper C- 1 of the liquid streams obtained from B- 1 and B- 3 , whose bottom product constitutes the feedstock of the fractionator C- 2 , A fractionator C- 2 , separating the naphtha, the diesel and the residue, and comprising a diesel-circulating reflux, A diesel stripper C- 3 , stripping the diesel obtained from C- 2 , A furnace F- 1 heating the feedstock of the mild hydrocracking zone R, A furnace F- 2 heating the feedstock of the fractionator C- 2 ,
with said process comprising optimized heat exchanges between different streams at different levels of said process for the purpose of ultimately obtaining a reduction in the consumption of energy and the cost of the unit and thus minimizing the environmental impact of the process while increasing its profitability.
[0018] Contrary to the prior art, the consumption of energy that is necessary for the compression of the recycling is taken into account in the energy balance of the process. This leads to a new scheme for optimized thermal integration in which the number of exchanges in the compression loop of the recycling is smaller. Actually, the smaller the number of exchanges, the smaller the loss of feedstock (delta P or pressure difference) that is undergone through the exchangers of the loop and consequently the lower the energy consumption for the compression of the recycling. A smaller number of exchanges in the compression loop of the recycling also brings about a significant reduction in the cost of exchangers installed in the loop, given the high pressure in the loop (between 70 and 130 bar).
[0019] More specifically, this invention can be defined as a process for mild hydrocracking of a fraction of the DSV or DAO type for the purpose of constituting the feedstock of a catalytic cracking unit, with the process comprising optimized heat exchanges between different streams at different levels of said process, or specifically:
[0020] a) At the exchange train of the heating of the low-pressure feedstock, by exchange:
In E- 7 A and E- 7 B with the stripped diesel obtained from C- 3 , In E- 4 with the gaseous effluent obtained from B- 1 , In E- 10 A and E- 10 B/C with the bottom of the fractionator, And in the following order: E- 7 B, E- 4 , E- 10 A, E- 7 A, E- 10 B/C,
[0025] b) At the exchange train of the cooling of the gaseous effluent obtained from B- 1 , by exchange:
In E- 3 with the mixture of the hydrogen addition and a portion of the recycled hydrogen, And then in E- 4 with the low-pressure feedstock,
[0028] c) At the exchange train of the heating of the liquid obtained from B- 3 , by exchange:
In E- 6 with the diesel-circulating reflux, And then in E- 5 with the bottom of the fractionator C- 2 ,
[0031] d) At the exchange train of the cooling of the effluent from the mild hydrocracking zone R, by exchange:
In E- 1 with the high-pressure feedstock of R, with E- 1 consisting of several calendars, In E- 2 with the feedstock of the fractionator C- 2 , with E- 2 being able to consist of several calendars and the calendars being able to be located between calendars of E- 1 ,
[0034] e) At the exchange train of the cooling of the bottom of the fractionator C- 2 , by exchange:
First in E- 8 with the diesel for reboiling the diesel stripper C- 3 , Then in E- 9 with the feedstock of the fractionator C- 2 , Then in E- 5 with the liquid obtained from B- 3 , And finally in E- 10 with the feedstock of the process, with E- 10 being able to consist of several calendars in series.
[0039] All of the preceding heat exchanges make it possible to reduce the overall energy consumption for heating the streams of the process and compressing the recycling, from 2 to 10%, and also make it possible to reduce the total number of exchangers of the unit and the number of high-pressure exchangers.
DETAILED DESCRIPTION OF THE INVENTION
[0040] To understand the invention, it is first necessary to describe the scheme of thermal integrations according to the mild hydrocracking process of the prior art shown in FIG. 1 . To facilitate understanding, the elements that are common to the scheme according to the prior art and to the scheme according to this invention retain the same name and the same symbol in FIG. 1 (according to the prior art) and FIG. 2 (according to the invention). The new elements are introduced with different letters.
[0041] The feedstock of the unit (stream 1 a ) can be a vacuum distillate (DSV or VGO, in English “vacuum gas oil”) or else a deasphalted oil (DAO). Hereinafter, without being limiting, the example of a VGO feedstock will be used. In a general manner, the feedstock of the process according to the invention will be mentioned. Let us recall in a succinct manner that a vacuum distillate is a fraction that is obtained from a vacuum distillation whose distillation interval is typically located within the range of 180° C. to 450° C. and that a deasphalted oil is an oil that has undergone a deasphalting treatment with a suitable solvent, generally propane or pentane.
[0042] The VGO (stream 1 a ) reaches a temperature of approximately 90° C. and low pressure at the inlet of the unit. The VGO is heated to a temperature that is generally between 300° C. and 450° C., and preferably between 350° C. and 400° C. (414° C. in the example, stream 5 b ), corresponding to the inlet temperature in the reaction zone R.
[0043] The heating of the VGO is usually done in a first step at low pressure:
First of all, using stripped diesel (stream 18 a ) by means of the exchanger E- 7 , Then using the diesel-circulating reflux (stream 20 a ) by means of the exchanger E- 6 , And then using the effluent from the bottom of the fractionator C- 2 (stream 19 c ) by means of the exchanger E- 10 that generally consists of two calendars in series.
[0047] Next, the VGO is compressed by a pump P- 2 and mixed with a very hydrogen-rich stream (stream 10 c ), and then it is heated, usually at high pressure:
Using the gaseous effluent (stream 7 b ) by means of the exchanger E- 4 , Using the reaction effluent (stream 6 a ) by means of the exchanger E- 1 that consists of several calendars in series (7, in the example, more generally between 4 and 10), with the calendars being called A to G in FIG. 1 for indicating that they are 7 in number. The VGO stream ( 4 e ) exits therefrom. And finally using the furnace F- 1 from which the VGO stream (stream 5 b ) exits at the temperature required for the input into the hydrocracking reactor (R).
[0051] After compression, a fraction of the VGO is short-circuited for the flexibility of the process (stream 3 ).
[0052] The reaction effluent (stream 6 a ) is cooled by heat exchange to a temperature of approximately 280° C. (more generally between 200 and 300° C.):
With the reaction feedstock by means of the exchanger E- 1 , With the bottom of the stripper C- 1 by means of the exchangers E- 2 A and E- 2 B generally positioned between the calendars E- 1 .
[0055] The gaseous phase of the reaction effluent at 280° C. (stream 7 a ), rich in hydrogen, is separated from the liquid phase (stream 12 ) in a high-pressure separator tank B- 1 .
[0056] Next, this gaseous phase (stream 7 a ) is cooled and partially condensed:
By heat exchange with the hydrocarbon effluent of the low-pressure cold tank B- 3 (stream 11 a ) in the exchangers E- 5 A and E- 5 B, By heat exchange with the stream 4 a in the exchanger E- 4 , with the stream 4 a being the mixture of VGO with hydrogen, By heat exchange with the stream 10 a in the exchanger E- 3 that consists of two calendars in series (E- 3 A and E- 3 B), with the stream 10 a being the mixture of the hydrogen addition (stream 9 ) with a portion of the recycled hydrogen (stream 21 ), And finally in a cooling tower A- 1 to a temperature of approximately 57° C. (57° C. in the example, more generally between 30° C. and 80° C.).
[0061] The stream exiting from the cooling tower A- 1 is separated into two streams in the high-pressure cold tank B- 2 :
A gas stream (stream 8 ) that is very rich in hydrogen, which is washed with an amine and then compressed in the zone K before being mixed again with the VGO feedstock, A liquid stream that is first expanded and then sent to the low-pressure cold tank B- 3 .
[0064] The liquid hydrocarbon stream that is obtained from B- 3 (stream 11 a ) is heated by means of the exchangers E- 5 B and E- 5 A, and then mixed with the liquid phase of the high-pressure hot tank B- 1 (stream 12 ).
[0065] The recycled hydrogen that is obtained from K is partially recycled toward the hydrocracking reactor(s) (R) (stream 22 ) and partially mixed (stream 21 ) with the hydrogen addition (stream 9 ) for forming the stream 10 a. The stream 10 a is heated by the stream 7 e and then the stream 7 c by means of the exchanger E- 3 that consists of two calendars in series.
[0066] Next, the stream 10 c, very rich in hydrogen, is mixed with the stream 2 (VGO) for forming the stream 4 a.
[0067] The mixture of streams 11 c and 12 is stripped with the steam in the stripper C- 1 . A fraction that is rich in light gases is separated at the top of C- 1 (stream 13 ). The stripped stream (stream 15 a ) is sent to the fractionator C- 2 after having been heated:
By the bottom of the fractionator C- 2 (stream 19 b ) by means of the exchanger E- 9 , Then by the reaction effluent by means of the exchanger E- 2 that generally consists of two calendars in series, And then in a furnace F- 2 to a temperature of approximately 370° C. (more generally of between 350 and 400° C.).
[0071] The gasoline fractions that are obtained at the top of C- 1 and C- 2 are mixed for forming the stream 14 .
[0072] The stream 20 a, diesel-circulating reflux, is cooled:
By means of the exchanger E- 6 , by heat exchange with the VGO feedstock of the unit (stream 1 b ), And then by means of a cooling tower A- 3 .
[0075] The diesel that is drawn off from the fractionator C- 2 (stream 16 ) is stripped in a so-called diesel stripper column C- 3 , reboiled by heat exchange with the bottom of the fractionator C- 2 (stream 19 a ) by means of the exchanger E- 8 .
[0076] The stripped diesel (stream 18 a ) is cooled by the low-pressure feedstock (stream 1 a ) by means of the exchanger E- 7 , and then it is cooled by the cooling tower A- 2 to a temperature of approximately 65° C. (more generally between 50° C. and 70° C.).
[0077] The bottom of the fractionator C- 2 , also called residue, is cooled:
By heat exchange in E- 8 with the diesel stream, By heat exchange in E- 9 with the product at the bottom of the stripper C- 1 (stream 15 a ), And finally by heat exchange with the feedstock (stream 1 c ) in the exchanger E- 10 that generally consists of two calendars in series.
[0081] FIG. 2 according to this invention can be described in the following manner:
[0082] In the process according to the invention, the heating of the VGO (stream 1 a ) is done:
Using the stripped diesel (streams 18 a and 18 b ) by means of the exchangers E- 7 A and E- 7 B, Using the gaseous effluent obtained from B- 1 (stream 7 b ) by means of the new exchanger E- 4 , Using the effluent from the bottom of the fractionator C- 2 (streams 19 d and 19 e ) by means of the exchangers E- 10 A and E- 10 B/C, And in the following order: E- 7 B, E- 4 , E- 10 A, E- 7 A, E- 10 B/C.
[0087] These changes relative to the prior art make it possible to bring the low-pressure feedstock upstream from the pump P- 2 (stream 1 f ) at a higher temperature (252° C. according to the invention instead of 232° C. in the prior art).
[0088] The stream if is compressed by means of P- 2 and then separated into two streams (stream 2 and stream 3 ) in a manner that is identical to the prior art.
[0089] The stream 2 is next mixed with hydrogen (stream 10 b ), hydrogen that will have been heated by means of the exchanger E- 3 in a single calendar instead of the two calendars in the prior art. The resulting mixture (stream 4 b ) is heated directly by the effluent of the reactor R (stream 6 a ) by means of E- 1 , contrary to the prior art where the mixture (stream 4 a ) was first heated by the gaseous effluent obtained from B- 1 by means of a calendar before being heated by the effluent of the reactor R in E- 1 . In addition, in the process according to the invention, E- 1 consists of a smaller number of calendars relative to the prior art (5 calendars instead of 7 in the example).
[0090] In the process according to the invention, the stream 11 a that is obtained from B- 3 is first heated in E- 6 using the diesel-circulating reflux (stream 20 a ) and then in E- 5 using the residue obtained from the fractionator C- 2 (stream 19 c ). In the prior art, the stream 11 a was heated by the gaseous effluent that is obtained from B- 1 in two calendars. These new heat exchanges (E- 5 and E- 6 ) make it possible to reduce the loss of feedstock in the loop for compression of hydrogen and the number of high-pressure exchangers.
[0091] In the process according to the invention, the stream 15 a (bottom of the stripper C- 1 ) is first heated with the bottom of the fractionator C- 2 in the exchanger E- 9 , and then with the reaction effluent by means of two calendars E- 2 A and E- 2 B. This makes it possible to have a stream at the inlet of the furnace F- 2 (stream 15 d ) at a temperature that is identical to that of the prior art. The thermal power of the furnace F- 2 is therefore identical in the process according to the invention and in the prior art.
[0092] All of these modifications relative to the prior art make it possible to reduce the requirements for hot utilities of the process and the cost of equipment of the process. Actually, the small number of exchanges in the compression loop makes it possible to reduce the energy consumption of the recycling compressor and the cost of high-pressure exchangers.
[0093] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
[0094] In the foregoing and in the examples, all temperatures are set forth uncorrected in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.
[0095] The entire disclosures of all applications, patents and publications, cited herein and of corresponding French application No. 13/55.050, filed Jun 3, 2013, are incorporated by reference herein.
EXAMPLE ACCORDING TO THE INVENTION
[0096] A mild hydrocracking unit consists of 3 reactors (7 catalytic beds).
[0097] Capacity: 442 t/h
[0098] Temperature of the reactors: 420° C. (mean temperature of each bed)
[0099] Pressure of the reactors: 101 to 129 bars effective
[0100] LHSV=0.313 h −1
[0101] Table 1 indicates the primary temperatures of the mild hydrocracking unit according to the prior art and according to the invention.
[0000]
TABLE 1
Temperature of the Streams
According to the Prior Art
According to the Invention
1a
90
2 and 3
232
252
4a
225
—
4b
243
238
5a
391
386
5b
414
6a
422
6f, 7a, and 12
280
7c
246
181
7f
184
—
8
57
10a
124
10b
181
226
10c
223
—
11c
266
15d
355
15e
370
18a
270
18b
136
208
18c
65
132
18d
—
65
19a
336
19d
206
294
19f
—
210
20a
236
20b
188
207
20c
175
[0102] Table 2 indicates the number of heat exchanges of each stream of the compression loop of the mild hydrocracking unit according to the prior art and according to the invention.
[0000]
TABLE 2
Number of Heat Exchanges in the Compression Loop
Number of Heat Exchanges
Process According
Process According
to the Prior Art
to the Invention
Hydrogen (Stream 10a)
2
1
High-Pressure
8
5
Hydrogen/VGO Mixture
(Stream 4a)
Reaction Effluent (Stream
9
7
6a)
Gaseous Effluent of B-1
5
2
(Stream 7a)
Total
24
15
[0103] The number of heat exchanges in the compression loop runs from 24 to 15. This makes it possible to reduce the energy consumption of the recycling compressor (Table 3).
[0000] Table 3 indicates the powers of the exchanges with utilities of the mild hydrocracking unit according to the prior art and according to the invention.
[0000]
TABLE 3
Energy Balance
Process
Thermal Power
Process According
According
(MWeq)
to the Prior Art
to the Invention
Deviation
Furnace F-1
12.2
15.1
+2.9
Furnace F-2
6.9
6.9
—
Compression of the
65.1
58.6
−6.5
Recycling (1)
Furnaces F-1 + F-2 +
84.2
80.6
−3.6
Compression
(1) The compression power of the recycling compressor is converted into MWeq by using the following factor: 1 MW of compression power = 4.37 MWeq of HP steam
[0104] The process according to the invention makes it possible to reduce the consumption of the recycling compressor by 6.5 MWeq.
[0105] The overall thermal power of the furnaces (F- 1 +F- 2 ) is slightly higher in the process according to the invention, but overall a reduction of the hot utilities by 3.6 MW is observed, or a reduction of 4.3%.
[0106] Another advantage of the invention is the increase in the temperature of the residue at the outlet of the process so as to be sent directly into the FCC riser without preheating or cooling in advance. In the prior art, this stream should be heated by 4° C. (or 0.9 MW) before going to the riser.
[0107] The process according to the invention also makes it possible to reduce the cost of the exchangers using the reduction of the number of high-pressure calendars and the total number of calendars.
[0000] Table 4 indicates the number and the cost of the exchangers of the mild hydrocracking unit according to the prior art and according to the invention. Only the exchangers having heat exchanges between streams of the process are considered.
[0000]
TABLE 4
Exchangers Having Heat Exchanges Between Streams of the Process
According to the
According to the
Prior Art
Invention
Deviation
Total Number of
20
17
−3
Exchangers
Number of High-
14
9
−5
Pressure Exchangers
Cost of Installed
44.2
36.9
−7.3
Exchangers (M$)
[0108] The process according to the invention makes it possible to reduce the cost of exchangers by 7.3 M$, or a reduction of 16% of the cost of the exchangers having heat exchanges between streams of the process.
[0109] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.
[0110] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
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This invention describes a process for mild hydrocracking of heavy hydrocarbon fractions of the vacuum distillate type or the deasphalted oil type with optimized thermal integration for the purpose of reducing the cost of the exchangers that are used as well as greenhouse gas emissions.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to an SiO 2 —TiO 2 glass suited especially for components used in EUV lithography, such as substrate materials for reflective mirror optics and masks or the like.
[0002] During a lithographic process, the structures for integrated circuits present on the mask are transferred to a silicon wafer by projection of laser radiation of a given wavelength. Especially in EUV lithography a wavelength of approximately 13 nm is used. Given the fact that there do not exist any materials that are pervious to light of that wave-length, reflective masks and optics are used in that process. It is the object of that technique to realize on the silicon wafer structures in widths of up to 35 nm.
[0003] SiO 2 —TiO 2 glasses with a TiO 2 content in the range of between approximately 6 and 8 percent by weight, for example, are employed as a preferred material in the production of components for EUV lithography, the thermal expansion occurring in the temperate range of between −50 and +100° Celsius being very small. For example, a glass of that type having a TiO 2 content of 6.85 percent by weight shows zero expansion in the temperature interval from 19 to 25° Celsius.
[0004] Flame hydrolysis is a commonly used method for the production of SiO 2 —TiO 2 glasses. As part of that method, gaseous SiO 2 (for example SiCl 4− or Si-alkoxide vapor) and TiO 2 precursors (such as TiCl 4− or Ti-alkoxide vapor) are exposed to a natural gas flame or a detonating gas flame (compare in this regard U.S. Pat. No. 5,970,751, WO 0232622 and U.S. Pat. No. 4,491,604, for example). The initial compounds thereby react, forming SiO 2 and TiO 2 droplets or mixtures thereof, which in turn are deposited on a die positioned below the flame. As a rule, the temperature conditions are selected to ensure that a compact glassy body is formed by that process. The process is also generally known as flame-hydrolytic direct deposition.
[0005] Flame-hydrolytic direct deposition is a preferred method for the production of SiO 2 —TiO 2 glasses, being a single-step process by means of which relatively large dimensions (masses of up to several hundred kilograms) can be produced in a comparatively low-cost way.
[0006] During EUV lithography, the structures to be transferred from the mask are inscribed by an electron beam. The realization of structures of smaller widths requires in this case ever higher acceleration speeds. As a result, instead of being moderated by the layers near the mask surface, an ever greater part of the electron beam will penetrate into and damage the substrate material below those layers. That damage normally makes itself felt by compaction of the material in the irradiated places. As it is only the irradiated side of the substrate material that gets compacted, i.e. that shrinks, the substrate may get distorted. This is a critical factor with respect to the imaging quality. The specifications for EUV mask substrates prescribe a flatness value of 50 nm PV (peak-to-valley value according to SEMI P37-1101). Extensive polishing and finishing processes are necessary if this value is to be reached. Any subsequent variation, which may occur for example during electron beam irradiation while inscribing the mask, may become critical already at a distortion of a few 10 nm.
[0007] Now, it has been found that SiO 2 —TiO 2 glasses produced by the flame-hydrolysis process are especially sensitive to damage by radiation.
[0008] In view of this it is a first object of the present invention to disclose an improved SiO 2 —TiO 2 glass which, compared with conventional SiO 2 —TiO 2 glasses, offers improved resistance to radiation.
[0009] It is a second object of the invention to disclose an improved SiO 2 —TiO 2 glass which is suited in particular for use in EUV lithography.
[0010] It is a third object of the invention to disclose a manufacturing process for the production of an improved SiO 2 —TiO 2 glass which, compared with conventional SiO 2 —TiO 2 glasses, offers better resistance to radiation.
SUMMARY OF THE INVENTION
[0011] The invention achieves this object by an SiO 2 —TiO 2 glass body which preferably is made by flame-hydrolysis and whose content of H 2 is <10 17 molecules/cm 3 , preferably <5·10 16 molecules/cm 3 .
[0012] It has been detected by the invention that the sensitiveness of SiO 2 —TiO 2 glasses or SiO 2 —TiO 2 glass bodies produced by flame-hydrolysis processes, is predominantly due to their hydrogen content.
[0013] As a result of the flame-hydrolysis process, conventional SiO 2 —TiO 2 glasses comprise free OH groups and physically solved elementary hydrogen, both of which can be regarded as doping agents. SiO 2 —TiO 2 glasses produced by a flame-hydrolysis process rarely have a concentration of OH groups of less than 300 ppm, while the H 2 content is normally 10 18 molecules/cm 3 or higher. When the flame-hydrolysis process takes place in a detonating gas flame, then the H 2 content may even be higher by one order of magnitude.
[0014] The damaging effect of the hydrogen is in contradiction to experience made in the past with the damage behavior of quartz glasses for transmissive lithography processes (at 248 and 193 nm). A high hydrogen content leads in this case to decreased reduction in transmission under irradiation, i.e. has a positive effect on the functionality of the material. In contrast, an influence of the hydrogen content of the material on a possible radiation-induced compacting effect has not been known heretofore.
[0015] Now, when the H 2 content is reduced according to the invention to less than 10 17 molecules/cm 3 , preferably to <5·10 16 molecules/cm 3 , a clearly lower sensitiveness of the SiO 2 —TiO 2 glass to radiation-induced shrinking (compaction) is observed.
[0016] As has been mentioned before, such SiO 2 —TiO 2 glasses with reduced hydrogen content are especially well suited as radiation-resistant components for EUV lithography and/or as starting materials for the production of such components, i.e. especially as mask substrates or mirror substrates.
[0017] With respect to the production method, the object of the invention is further achieved by a method where an SiO 2 —TiO 2 glass is produced preferably by flame-hydrolysis, whereafter the content of H 2 is reduced by annealing of the glass.
[0018] The glass is preferably annealed for this purpose at a temperature of between approximately 400 and 8000 Celsius.
[0019] Preferably, the glass is annealed for a period of 12 hours to 7 days, more preferably of 2 to 5 days.
[0020] Duration and temperature are preferably selected for this purpose to obtain a H 2 content <5·10 17 molecules/cm 3 , preferably <5*10 16 molecules/cm 3 .
[0021] The temperature is conveniently selected in this case to be as high as possible to achieve H 2 diffusion, but at the same time to be low enough to not change the structure of the glass. Annealing is, thus, preferably carried out at a temperature below the glass transition temperature T g .
[0022] Annealing is carried out, preferably, in an atmosphere that does not cause strong oxidation, for example in air, a vacuum or in a protective gas, such as He or Ar.
[0023] Production of the quartz glass by the flame-hydrolysis process is preferably effected by “rocking”, i.e. with a relative movement between the burner and the quartz glass body in axial and radial direction, see U.S. Pat. No. 6,595,030 which is fully incorporated by reference.
[0024] The diameter of the cylindrical quartz glass body so produced is preferably ≦180 mm, for example 220 mm to 260 mm. As a rule, only an inner “good” glass zone of, for example, 120 to 140 mm is used out of that cylinder. The resulting quartz glass body can then be further processed by remolding, cutting, grinding, lapping and/or polishing, to form components preferably for EUV lithography.
[0025] According to a preferred embodiment of the invention the homogeneity (peak-to-valley, PV) of the coefficient of thermal expansion does not exceed 6 ppb/K.
[0026] It is understood that the features of the invention mentioned above and those yet to be explained below can be used not only in the respective combination indicated, but also in other combinations or in isolation, without leaving the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Further features and advantages of the invention will be apparent from the description that follows of certain preferred embodiments, with reference to the drawing in which:
[0028] FIG. 1 shows a plot of the variation of the PV value as a function of the H 2 content, together with a regression plot;
[0029] FIG. 2 shows a plot of the radiation-induced radius of curvature, as a function of the H 2 content, together with a regression plot;
[0030] FIG. 3 shows the homogeneity of the CTE (measured by interferometer, IF) over the local coordinate (PV 1.1 ppb/K) and ultrasound (US) over the local coordinate (PV 4.6 ppb/K); and
[0031] FIG. 4 shows the homogeneity of the TiO 2 content over the local coordinate (PV value=0.06 percent by weight).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] The improved resistance to radiation of SiO 2 —TiO 2 glasses with a low H 2 content, produced by flame-hydrolysis, was verified by the following experiment:
EXAMPLE
[0033] An SiO 2 —TiO 2 quartz glass cylinder is produced from SiCl 4 and TiCl 4 by the flame-hydrolysis process as described in U.S. Pat. No. 6,595,030. The quartz glass body so obtained showed the homogeneity of Ti content and CTE illustrated in FIG. 3 and FIG. 4 . Starting out from the cylinder, mask substrates having a diameter of 6 inches were produced by cutting, remolding, lapping and polishing.
[0034] Three polished mask substrates of 6 inches in diameter, with different H 2 concentrations, were first subjected to an initial flatness measurement, whereafter the entire lower surfaces of the substrates were irradiated with electrons in identical way. This was followed by a second flatness measurement and determination of the distortion of the substrate. To this end, both the induced radius of curvature and the variation of the PV value can be used as measure of flatness variation.
[0035] The distortion of the substrate and the H 2 content in the glass show a strong linear correlation, the flatness variation increasing as the H 2 content rises and/or the induced radius of curvature decreasing as the H 2 content rises.
[0036] The results obtained for three different substrates, all produced by the flame-hydrolysis process, with different H 2 content, are summarized in Table 1.
[0037] In order to reduce the hydrogen content, Substrate II was subjected to a separate temperature treatment after the flame-hydrolytic deposition process, at temperatures generally below the glass transition temperature, i.e. in a range of 400 to 800° Celsius. That treatment was carried out in air (not, however, in an atmosphere with pure oxygen).
[0038] The data from the temperature treatment of Substrate II are summarized in Table 2. In contrast, Substrates I and III were not subjected to any further temperature treatment.
[0039] The H 2 content values determined were those summarized in Table I. The residual hydrogen content values were determined in the present case by Raman spectroscopy.
TABLE 1 Induced Radius of H 2 content curvature PV variation [10 16 molecules/cm 3 ] [m] [nm] Substrate I 350 33400 73 Substrate II 3 66600 37 Substrate III 100 56100 44
[0040]
TABLE 2
Temperature
at start
Final temperature
Duration
[° C.]
[° C.]
[h]
5
500
3
500
500
60
500
5
5
[0041] The interdependencies of the PV variation and/or the induced radius of curvature and the H 2 content, resulting from the data summarized in Table 1, are illustrated in FIGS. 1 and 2 .
[0042] These show the measured values contained in Table 1 together with the linear regression according to the method of least squares and relevant tolerances (2σ lines).
[0043] In FIG. 1 , the flatness variation (PV variation in nanometers) of polished mask substrates, made from SiO 2 —TiO 2 glass with a TiO 2 content of 6.8 percent by weight, is given as a function of the H 2 -Gehalt in the substrate material after electron beam irradiation (in 10 16 molecules/cm 3 ). The linear regression is plotted with R 2 =99,19% and with relevant tolerance lines (2σ lines for the forecast range of 95%).
[0044] In FIG. 2 , the corresponding correlation of the induced radius of curvature (given in 103 m) is plotted as a function of the H 2 content (in 10 16 molecules/cm 3 ). The linear regression is plotted in this case with R 2 =99,84% and with the tolerance lines (2σ lines).
[0045] It can be clearly seen that the PV variation increases linearly with the rise of the H 2 content in the stated range.
[0046] Likewise, it can be seen that the induced radius of curvature decreases linearly with the rise of the H 2 content in the stated range.
[0047] In FIG. 3 the homogeneity of the CTE is demonstrated by plotting ΔCTE (in ppb/K) over the local coordinate (in mm), measured (a) by interferometry IFM (PV value: 1.1 ppb/K) and (b) by ultrasound US (PV value: 4.6 ppb/K).
[0048] In FIG. 4 the homogeneity of the TiO 2 content is demonstrated by plotting the TiO 2 content (in wt.-%) over the local coordinate, measured in millimeters (PV value: 0.06 wt.-%).
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The invention discloses an SiO 2 —TiO 2 glass, which is preferably made by flame-hydrolysis and which distinguishes itself by increased resistance to radiation, especially in connection with EUV lithography. By purposefully reducing the hydrogen content, clearly improved resistance to radiation and reduced shrinking is achieved.
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FIELD OF THE INVENTION
The present invention relates to computerized tomography (CT) X-ray imaging and in particular to methods for generating high-resolution CT images.
BACKGROUND OF THE INVENTION
In CT X-ray imaging of a patient, X-rays are used to image internal structure and features of a region of the patients body. The imaging is performed by a CT-imaging system, hereinafter referred to as a “CT scanner”, which generally comprises an X-ray source and an array of closely spaced X-ray detectors positioned to face the X-ray source. The X-ray source and array of detectors are mounted in a gantry so that a person being imaged with the CT scanner, generally lying on an appropriate support couch, can be positioned within the gantry between the X-ray source and the array of detectors. The gantry and couch are moveable relative to each other so that the X-ray source and detector array can be positioned axially, along a “z-axis”, at desired locations along the patient's body. The gantry comprises a stationary structure, referred to as a stator, and a rotary element, referred to as a rotor. The rotor is mounted to the stator so that the rotor, is rotatable in a plane perpendicular to the z-axis about a center, referred to as an “isocenter”, of the rotor. The z-axis is usually chosen for convenience to pass through the rotor isocenter so that the rotor rotates about the z-axis.
In third generation CT scanners the X-ray source and detectors are mounted to the rotor. Some, generally older, “single-slice” third generation CT scanners image a region of a patient by imaging a plurality of relatively thin slices of the region, one slice at a time. A single-slice third generation CT scanner comprises a single, generally curved row of detectors located along an arc of a circle that has its plane perpendicular to the z-axis and its center located at a “focal spot” of the scanner's X-ray source. The X-ray source provides a planar, fan-shaped X-ray beam for illuminating the X-ray detectors with X-rays. The fan beam emanates from the focal spot of the X-ray source and is coplanar with the row of X-ray detectors. A vertex angle of the fan beam is referred to as a “fan angle” and a bisector of the fan angle is referred to as an “axis” of the fan beam.
In fourth generation CT scanners, the X-ray detector array comprises detectors positioned around the perimeter of a circle to form a full circle of detectors. The circle of detectors is stationary and the X-ray source is mounted to the rotor and rotates with the rotor. A single-slice fourth generation CT scanner comprises a single circle of X-ray detectors and a fan beam for illuminating the detectors with X-rays. A fourth generation scanner operates similarly to a third generation scanner and the following discussion which generally refers to third generation configurations of CT scanners relates to fourth generation CT scanners as well, with appropriate adjustments readily understood by persons of the art.
In some single slice CT scanners, to image a region of a patient, the patient is moved stepwise along the z direction to “step” the region through the gantry that houses the X-ray source and detector array. Following each step, the X-ray source is rotated around the isocenter to illuminate a thin slice of the region with X-rays from a plurality of different, usually equally spaced angles, referred to as “view angles”. Generally, the X-ray source is rotated through an angle of 360° or (180+Φ) degrees, where Φ is an angular width of the fan angle of the fan beam provided by the X-ray source. A “step and rotate” scan is referred to as an “axial scan”.
At each view angle, each detector in the array of detectors measures intensity of X-rays from the source that pass through the slice along an “attenuation path” from the X-ray source to the detector. The measured intensity provides a value for a line integral of the absorption coefficient of the material along the attenuation path. (The line integral is often, conventionally, referred to as a “Radon transform” but will herein be referred to as a line integral. It is further noted that “line integral data” is alternatively referred to herein also as “line attenuation data”.) The set of line integral values for a slice generated from intensity measurements provided by all the detectors in the detector array for a given view angle of the X-ray source is referred to as a “view” at the view angle.
The set of all the views of the slice is referred to as a “projection” of the slice. A “span” of view angles in a projection refers to an angular difference between a smallest view angle and a largest view angle of views comprised in a projection. For each view angle in a span of a projection, the projection comprises line integrals for a plurality of parallel attenuation paths, each of which passes through the slice at an angle equal to the view angle but at a different distance from the z-axis. A set of line integrals in a projection of a slice for parallel attenuation paths that pass through the slice at an angle equal to a given view angle is referred to as a “parallel” view of the slice at the view angle. In symbols, if the line integral for an attenuation path that passes through the slice at an angle φ and a distance s from the z axis is represented by R(φ,s) and the parallel view at angle φ having N samples is represented by PV(φ,N) then PV(φ,N)={R(φ, s 1 ), R(φ, s 2 ) . . . R(φ, s N )}. To distinguish between a parallel view at a view angle and a view provided by a fan beam at the view angle (for which each attenuation path passes through the slice at different angle) the latter view will hereinafter be referred to as a “fan beam view”.
Let a function “R φ (s)” of s having a value equal to the line integral R(φ,s) for a given constant angle φ be referred to as a Radon function at the angle φ. It is noted that the Radon functions at view angle φ and (φ+180°) are the same. A convention is therefore used hereinafter that an angle of a Radon function is greater than or equal to 0° and less than 180°. The set of line integrals at different distances s from the isocenter that are comprised in parallel views PV(φ,N) and PV(φ+180°,N) at angles φ and (φ+180°) respectively provide samples for the same Radon function R φ (s).
To generate an image of a slice from a projection of the slice, each parallel view of the slice provided by the projection is used to generate a Fourier transform of a corresponding Radon function of the slice. The Fourier transforms of the Radon functions provide values for a two-dimensional Fourier transform of the X-ray absorption coefficient of tissue in the slice. The two dimensional Fourier transform is processed in accordance with any of various two-dimensional filtered back projection algorithms known in the art to generate a two dimensional spatial function. The spatial function represents the X-ray absorption coefficient of material in voxels of the slice as a function of position of the voxels. The values for the absorption coefficient for the slice are used to characterize and image tissue in the slice. Values of the absorption coefficient for a plurality of contiguous slices in the region of the patient's body can be used to used to provide a three-dimensional image of internal organs in and features of the region.
Resolution of a CT image of a slice generated from attenuation measurements provided by a CT scanner is a function, inter alia, of a sampling rate at which samples, i.e. line integrals, are acquired for each Radon function of the slice. To an extent that the number of samples acquired for a Radon function increases, a Nyquist sampling rate for the function and a maximum frequency for the Fourier transform of the Radon function increases. As the Nyquist sampling rate increases spatial resolution of the absorption coefficient function and corresponding CT image of the slice increases and approaches an upper limit determined by a size of a cross section of attenuation paths through the slice.
For a fan beam of a CT scanner that is rotated (180°+Φ) about an isocenter located on the fan beam axis, a number of different line integrals provided for each Radon function of the slice is generally equal to the number of detectors in the scanner's detector array. Hereinafter, a fan beam rotated about an isocenter located on the fan beam's axis is said to be “center rotated”. Increasing the angle through which a center rotated fan beam is rotated from (180°+Φ) to 360° does not increase the number of samples acquired for each Radon function of a slice. For a center rotated fan beam, rotated through 360°, X-ray detectors on opposite sides of the fan beam axis provide line integrals for same attenuation paths through the slice. Parallel views of the slice at view angles φ and (φ+180°) provide line integrals for the same attenuation paths through the slice and for the same Radon function R φ (s).
To double a number of different line integrals acquired for each Radon function of a slice, it is known to offset the fan beam axis from the isocenter and rotate the beam about the isocenter through about 360°. For a fan beam that is “offset rotated” through 360°, X-ray detectors on opposite sides of the fan beam axis provide line integrals for different, generally interleaved, attenuation paths through the slice. In particular a parallel view for a view angle φ and for a view angle (φ+180°) provide different line integrals for a same Radon function R φ (s). A number of samples for the Radon function R φ (s) may be doubled by combining the samples provided by the view at view angle φ and at view angle (φ+180°). Doubling the number of different line integrals acquired for each Radon function of the slice doubles the Nyquist sampling rate for the Radon functions of the slice and generally improves resolution of images generated from attenuation measurements acquired with the fan beam.
In some single slice CT scanners a “helical scan” of a patient is performed instead of an axial scan as described above. In a helical scan, a region of a patient to be imaged is continuously advanced through the gantry while the X-ray source simultaneously continuously rotates around the patient and fan beam views of slices in the region are acquired “on the fly”.
The two dimensional filtered back projection algorithms used to generate an image of a slice from “axial scan” line integrals assume that the line integrals of all the fan beam views used to image a slice are for attenuation paths through the patient that are coplanar with the slice. For helical scans, however, no two fan beam views are coplanar. A first fan beam view in a helical scan is displaced along the z-axis from a second fan beam view of the helical scan by a distance determined by the pitch of the helical scan and an angular difference between the view angles of two views. However, usually, for single slice scanners, the pitch of a helical scan is small and for an angular difference of 360° between the view angles of first and second fan beam views, a difference between the z-coordinates of the views is relatively small. As a result, usually, for “helical” single-slice scanners, high resolution, high Nyquist sampling rate data for providing high resolution images can be acquired for each slice using offset rotation of the scanner's fan beam and rotating the beam through 360°.
Modern CT scanners are often multislice scanners designed to simultaneously image a plurality of slices of a patient. A multislice third generation CT scanner comprises a detector array having a plurality of parallel rows of X-ray detectors closely spaced one next to the other along the z-axis direction. The scanner's X-ray source provides a cone shaped beam of X-rays, rather than a planar, fan-shaped X-ray beam for illuminating the X-ray detectors. A multislice fourth generation CT scanner comprises a detector array having a plurality of closely spaced circles of detectors and an X-ray cone beam for illuminating the detectors.
Cone beam geometry may be described with reference to a midplane of the cone beam, which is a plane perpendicular to the z-axis that includes the focal spot of the X-ray source, which generates the cone beam. A vertex angle of the fan-shaped cross section of the cone beam in a plane perpendicular to the midplane that passes through the focal spot is a “cone angle” of the cone beam. For each cone beam view angle a cone beam illuminates a plurality of slices in a region of a patient, where the focal spot of the X-ray source and at least one row of X-ray detectors define each slice. A cone beam view at a given cone beam view angle comprises views acquired with the cone beam for all the slices that the cone beam illuminates at the cone beam angle.
As in the case for single slice scanners, multislice CT scanners can be operated to provide axial scans and/or helical scans of a patient. However, in an axial scan performed by a multislice scanner, the steps are substantially larger than the steps in a single slice scanner. Furthermore, as a cone beam in a multislice scanner is rotated about the z-axis at a fixed z-coordinate, except for views, “midplane views”, acquired from X-rays that propagate in the cone beam midplane, none of the views are coplanar. For a helical scan performed by a multislice scanmer, the pitch of the helical scan is substantially larger than a pitch of a helical scan performed by a single slice scanner. For a helical scan of a multislice scanner, not only are none of the views acquired by the scanner coplanar, but parallel cone beam views acquired by the scanner for view angles differing by 180° are displaced from each other along the z-axis by relatively large distances. In a helical scan performed by a multislice scanner, the midplane of the scanner's cone beam may be displaced along the z-axis by more than 20 mm in a 360° rotation of the scanners' X-ray source. For both axial and helical scans lack of coplanarity increases as the cone beam angle increases.
As a result, for a multislice scanner having a cone beam characterized by a large cone angle data processing schemes conventionally used for processing data from single slice scanners or from small cone angle multislice scanners may introduce overly obtrusive artifacts in images provided by the scanners. In particular prior art methods for combining parallel views at φ and (φ+180°) acquired from 360° offset rotation of the scanner's cone beam to generate “high sampling rate” Radon functions and therefrom an image having enhanced resolution may result in and an unacceptable level of artifacts in the image.
U.S. Pat. No. 5,802,134, the disclosure of which is incorporated herein by reference discloses a nutating slice CT image reconstruction apparatus and method for generating a set of projection data that is used to reconstruct a series of planar image slices. A cone beam image reconstruction algorithm is discussed by Ge Wang, et.al. in an article entitled, “A General Cone-Beam Reconstruction Algorithm; IEEE Transactions on Medical Imaging; Vol. 12. No. 3; September 1993. A method of generating images from cone beam data is presented in an article by Marc Kachelriesz et. al. entitled “Advanced single-slice rebinning in cone beam spiral CT”; Med. Phys. 27 (4); April 2000.
SUMMARY OF THE INVENTION
An aspect of some embodiments of the present invention relates to providing methods for improving the resolution of images provided by multislice scanners.
An aspect of some embodiments of the present invention relates to providing a method for processing data for imaging a region of a patient that is previously acquired by a multislice CT scanner in which the scanner's cone beam is offset rotated.
The inventor has determined that in an image of a region generated by a multislice scanner from offset rotation parallel views at φ and (φ+180°) that are combined to provide high sampling rate Radon functions, artifacts are often caused by low spatial frequency components of the Fourier transform of the region's absorption coefficient generated from the Radon functions. Therefore, in accordance with an embodiment of the present invention, for an image of a region provided by a multislice scanner, low spatial frequency Fourier components of the absorption coefficient for voxels in the region are generated from cone beam views that are not combined to provide high resolution Radon functions. High spatial frequency components of the Fourier transform of the absorption coefficient for voxels are generated from data acquired from offset rotated cone beam views in a view angle span of about 360° that are combined to provide high sampling rate Radon functions.
The low spatial frequency Fourier components of the absorption coefficients are filtered and back projected to determine a “low frequency” absorption coefficient for voxels in the slice and therefrom a “low frequency” image of the voxels. The high spatial frequency components of the absorption coefficients are filtered and back projected to determine a “high frequency” absorption coefficient for voxels in the slice and therefrom a “high frequency” image of the voxels. The low and high frequency images are added to provide a final image of the region.
By generating low frequency components of the Fourier transform of the absorption coefficient from cone beam views that are not combined to provide high resolution Radon functions, artifacts in the image are moderated. The high frequency components of the Fourier transform, which are provided from parallel views at φ and (φ+180°) that are combined to provide high sampling rate Radon functions, provide for improved resolution of the final image.
In accordance with an embodiment of the present invention, before adding the high frequency image to the low frequency image to produce the final image, the high frequency image is weighted to provide a desired ratio between the low and high frequency images in the final image. Weighting of the high frequency image enables the final image to be smoothed or sharpened as required to provide desired viewing of the imaged region.
There is therefore provided, in accordance with an embodiment of the present invention, a CT scanner for providing an image of a region comprising: at least one X-ray cone beam for illuminating the region with X-rays; a plurality of rows of X-ray detectors that generate signals responsive to line attenuation of X-rays from the at least one X-ray source that pass through the region; a controller that controls the at least one X-ray cone beam to acquire line attenuation data for the region for different view angles of the region; and a processor that receives the signals and:
a) determines low spatial frequency components of the image from the data;
b) generates a first spatial image of the region from the low frequency components;
c) determines high spatial frequency components of the image from the data;
d) generates a second spatial image of the region from the high frequency components; and
e) combines the first and second images to generate the CT image.
Optionally, the at least one X-ray cone beam is offset rotated. Additionally or alternatively the at least one X-ray cone beam comprises a plurality of X-ray cone beams.
In some embodiments of the present invention, the controller controls the at least one cone beam to acquire line attenuation data of the region for a span of view angles of about 360°. Optionally, the processor processes the line attenuation data to generate parallel views for the span of view angles.
Optionally, the low frequency spatial components are band limited by a Nyquist frequency ω N determined by a number of line integrals in a parallel view. Optionally, the low frequency spatial components are Fourier components.
In some embodiments of the present invention, the high frequency spatial components are band limited by a Nyquist frequency 2ω N determined by twice a number of line integrals in a parallel view. Optionally, the processor interleaves parallel views having an angular separation of 180° and Fourier transforms the interleaved parallel views to determine the high frequency Fourier components. Optionally, the processor interleaves parallel views with a number of null values equal to a number of line integrals in a parallel view and Fourier transforms the interleaved parallel views to determine the high frequency Fourier components.
Optionally, to generate the second image the processor generates a first partial high frequency image from interleaved parallel views in a portion of the view angle span from 0° to about 180° and a second partial high frequency image from a portion of the view angle span from about 180° to about 360° and combines the first and second partial images.
In some embodiments of the present invention, the processor filters the high frequency data with a high band pass filter f H (ω). Optionally, the high frequency filter f H (ω) is equal substantially to zero for values of ω substantially less than ω N and values of ω greater than 2ω N . Additionally or alternatively, f H (ω) is substantially equal to one for values of ω in a neighborhood of ω N . In some embodiments of the present invention, f H (ω) decreases adiabatically to zero at a value ω in a neighborhood of 2ω N .
In some embodiments of the present invention, the processor filters the low frequency components with a low frequency band pass filter f L (ω).
In some embodiments of the present invention, the functions f H (ω) and f L (ω) are related by an expression f(ω)=f H (ω)+f L (ω) where f(ω) is equal substantially to one for values of ω substantially less than ω N and equal to substantially zero for ω greater than 2ω N . Optionally, f(ω) is equal substantially to one for values of ω in a neighborhood of ω N . Additionally or alternatively, f(ω) optionally decreases adiabatically to zero at a value of ωless than and in a neighborhood of 2ω N .
In some embodiments of the present invention, low frequency filter f L (ω) has non-zero values for ω less than ω N and is equal to substantially zero for values of ω greater than ω N . In some embodiments of the present invention, f L (ω) is equal to substantially one for values of ω substantially less than ω N . In some embodiments of the present invention, f L (ω) adiabatically, decreases to zero at a value for ω in a neighborhood of ω N .
There is further provided, in accordance with an embodiment of the present invention, a method of generating a CT image from line attenuation data of a region comprising: determining low spatial frequency components of the image from the data; generating a first spatial image of the region from the low frequency components; determining high spatial frequency components of the image from the data; generating a second spatial image of the region from the high frequency components; and combining the first and second images to generate the CT image.
Optionally, the line attenuation data comprises data acquired using an offset rotated X-ray cone beam. Optionally, the line attenuation data comprises data acquired using X-ray cone beams provided by a plurality of X-ray sources.
In some embodiments of the present invention, the line attenuation data comprises data from cone beam views of the region in a span of view angles of about 360°.
Optionally, processing the line attenuation data comprises generating parallel views for the span of view angles.
Optionally, determining low frequency spatial components comprises determining frequency components that are band limited by a Nyquist frequency ω N determined by a number of line integrals in a parallel view.
Optionally, determining the low frequency spatial components comprises Fourier transforming each parallel view to determine low frequency Fourier components.
Additionally or alternatively, determining high frequency spatial components comprises determining frequency components that are band limited by a Nyquist frequency 2ω N determined by twice a number of line integrals in a parallel view.
Optionally, determining the high frequency Fourier components comprises generating interleaved parallel views by interleaving data from parallel views having an angular separation of 180° and Fourier transforming the interleaved parallel views to determine high frequency Fourier components.
Optionally, determining the high frequency Fourier components comprises generating interleaved parallel views by interleaving data from each parallel view with a number of null values equal to a number of line integrals in a parallel view and Fourier transforming the interleaved parallel views. Optionally, determining the second image comprises generating a first partial high frequency image from interleaved parallel views in a portion of the view angle span from 0° to about 180° and a second partial high frequency image from a portion of the view angle span from about 180° to about 360° and combining the first and second partial images.
In some embodiments of the present invention, the method comprises filtering the high frequency data with a high band pass filter f H (ω). Optionally, high frequency filter f H (ω) is equal substantially to zero for values of ω substantially less than ω N and values of ω greater than 2ω N . Alternatively or additionally f H (ω) is substantially equal to one for values of ω in a neighborhood of ω N . In some embodiments of the present invention, f H (ω) decreases adiabatically to zero at a value ω in a neighborhood of 2ω N .
In some embodiments of the present invention, the method comprises filtering the low frequency components with a low frequency band pass filter f L (ω).
In some embodiments of the present invention, the functions f H (ω) and f L (ω) are related by an expression f(ω)=f H (ω)+f L (ω) where f(ω) is equal substantially to one for values of ω substantially less than ω N and equal to substantially zero for ω greater than 2ω N . Optionally, f(ω) is equal substantially to one for values of ω in a neighborhood of ω N . Additionally or alternatively, f(ω) optionally decreases adiabatically to zero at a value of ω less than and in a neighborhood of 2ω N .
In some embodiments of the present invention, low frequency filter f L (ω) has non-zero values for ω less than ω N and is equal to substantially zero for values of ω greater than CON. In some embodiments of the present invention, f L (ω) is equal to substantially one for values of ω substantially less than ω N . In some embodiments of the present invention, f L (ω) adiabatically, decreases to zero at a value for ω in a neighborhood of ω N .
There is further provided, in accordance with an embodiment of the present invention, a method of generating a CT image of a region from cone beam data comprising: acquiring line attenuation data for first and second parallel views of the region at view angles separated by an angular difference of 180°; interleaving data from each parallel view with null values; generating in accordance with a 3D back projection algorithm first and second images of the region using data in the first and second interleaved views respectively; and combining the first and second images to generate the CT image of the region.
BRIEF DESCRIPTION OF FIGURES
Non-limiting examples of embodiments of the present invention are described below with reference to figures attached hereto and listed below. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with a same numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are chosen for convenience and clarity of presentation and are not necessarily shown to scale.
FIG. 1 schematically shows a third generation multislice scanner imaging a region of a patient using a cone beam generated by the scanner,
FIG. 2 schematically shows attenuation paths for a cone beam view acquired with the cone beam shown in FIG. 1 ;
FIG. 3 schematically shows attenuation paths for a cone beam parallel view at a view angle of 0° acquired by the CT scanner shown in FIG. 1 ;
FIG. 4 schematically shows attenuation paths for a cone beam parallel view at a view angle of 315° (−45°) acquired by the CT scanner shown in FIG. 1 ;
FIG. 5 schematically shows attenuation paths for a cone beam parallel view at a view angle of 0° acquired by the CT scanner shown in FIG. 1 interleaved with attenuation paths of a parallel view at a view angle 180° acquired by the scanner,
FIG. 6 shows a schematic graph of line integral values for attenuation paths of the 0° cone beam parallel view shown in FIG. 3 ;
FIG. 7 shows a schematic graph of line integral values for interleaved attenuation paths at 0° and 180° shown in FIG. 5
FIGS. 8A and 8B schematically show high sampling rate parallel views at 0° and 180°, in accordance with an embodiment of the present invention, and
FIG. 9 shows a flow chart of a method of generating an image from data acquired by a CT scanner, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 schematically shows a third generation multislice CT scanner 120 imaging a region 122 of a patient 124 . Only features of multislice scanner 120 germane to the discussion are shown in FIG. 1 and only a portion of patient 124 is shown so that features germane to the discussion are clearly visible.
Multislice scanner 120 comprises a detector array 126 having rows 128 and columns 130 of X-ray detectors 132 and an X-ray source 134 having a focal spot 136 that provides a cone beam 138 of X-rays for illuminating region 122 of patient 124 . X-ray source 134 and detector array are mounted to a rotor 140 of a gantry (not shown) comprised in multislice scanner 120 . Rotor 140 is rotatable around the z-axis of a coordinate system 42 . By way of example, detector array 126 is shown comprising three rows 128 of detectors 132 , which rows are individualized by labels DR 0 , DR 1 and DR −1 . Patient 124 is supported on a couch (not shown) during imaging of the patient. The couch is controllable to be translated axially along the z-axis to position region 122 as required between X-ray source and detector array 126 .
Cone beam 138 has a midplane MP 0 defined by focal spot 136 and detector row DR 0 , and two “declination planes”, DP −1 and DP 1 defined by focal spot 136 and by detector rows DR −1 and DR 1 respectively. A vertex angle Φ of midplane MP 0 is a fan angle of cone beam 138 and a bisector 141 of fan angle Φ is an axis of cone beam 138 . A sagittal plane SP 0 of cone beam 138 is a plane that passes through axis 141 and is perpendicular to midplane MP 0 . A vertex angle Ψ of sagittal plane SP 0 is a cone beam angle of cone beam 138 . A column 130 of detectors 132 and focal spot 136 define a plane parallel to the z-axis, hereinafter referred to as an axial plane, of cone beam 138 . An axial plane “AP” of cone beam 138 defined by a given column 130 of detectors 132 makes an angle with sagittal plane SP 0 that is referred to as an “azimuthal angle”. An axial plane AP for a particular column 142 of detectors 132 is shown in FIG. 1 and its azimuthal angle is indicated as angle θ.
An intersection point 144 of the z-axis with midplane MP 0 of cone beam 138 is an isocenter of the scanner. Optionally, as shown in FIG. 1 , axis 141 of cone beam 138 is offset from isocenter 144 and cone beam 138 is offset rotated to acquire attenuation measurements and therefrom line integrals for region 122 . In FIG. 1 scanner 120 is shown by way of example acquiring attenuation measurements for region 122 at a view angle of 0°.
Multislice scanner 120 can generally be operated in an axial mode or in a helical mode to image region 122 of patient 124 . In an axial mode region 122 is stepped axially along the z-axis through rotor 140 of the scanner. Following each step, rotor 140 rotates around the z-axis to rotate X-ray source 134 and cone beam 138 around region 122 , generally through 360°, to acquire attenuation measurements along each attenuation path through the region from focal spot 136 to a detector 132 for each of a plurality of cone beam view angles. In a helical mode, region 122 is moved continuously along the z-axis through rotor 140 as rotor 140 simultaneously, continuously rotates around the z-axis to acquire attenuation measurements.
At any view angle φ of cone beam 138 , the cone beam simultaneously illuminates three slices of region 122 , a slice in each of midplane MP 0 , declination plane DP −1 and declination plane DP 1 and acquires a view for each of the slices. The slices in planes MP 0 , DP −1 and DP 1 are schematically shown for Φ=0° in FIG. 1 by ellipses labeled respectively SL 0 , SL −1 (0°) and SL 1 (0°). The labels for “off-midplane” slices SL −1 (0°) and SL 1 (0°) include as arguments the view angle of cone beam 138 because slices of region 122 that lie in declination planes DP 1 and DP −1 are different for different view angles φ of cone beam 138 .
In an axial mode scan for a fixed z-axis position of the patient, none of the views of slices of region 122 acquired during rotation of cone beam 138 around the region, except for midplane views, are coplanar. In a helical mode scan none of the views of slices of region 22 acquired by scanner 120 are coplanar. As a result, generally, conventional 2D filtered back projection procedures used to generate an image of a region from data acquired by single slice scanners are not used to generate an image provided by a multislice scanner such as multislice scanner 120 , particularly if the multislice scanner has a large cone angle.
In some procedures, cone beam data acquired by each row 128 of detectors 132 during a scan of region 22 is binned to provide parallel views of the region for a plurality of different view angles. Data in the parallel views is interpolated, filtered, weighted and back-projected in accordance with various known 2D or 3D back-projection algorithms to determine absorption coefficients for voxels in region 122 and therefrom an image of the region.
Let a cone beam parallel view at a given view angle for cone beam 138 comprise line integrals for all attenuation paths through region 122 whose projections onto the midplane MP 0 make an angle with the y-axis equal to the view angle. Hereinafter for ease of visualization and presentation, projections onto midplane MP 0 will be shown and also referred to as projections onto the x-y plane of coordinate system 42 . Since attenuation paths that lie in a same axial plane have a same projection on the xy-plane, a cone beam parallel view comprises line integrals for groups of attenuation paths lying in, “belonging to”, same axial planes. For exemplary multislice scanner 120 comprising three rows 128 of detectors 132 , a cone beam parallel view comprises line integrals for each of a plurality of groups of three attenuation paths. A set of line integrals in a cone beam parallel view for attenuation paths defined by detectors 132 in a same row 128 of detectors 132 is referred to as a parallel view of the cone beam parallel view. Each cone beam parallel view therefore comprises three parallel views, one parallel view for each detector row DR 0 , DR 1 and DR −1 .
FIG. 2 schematically shows attenuation paths 150 for a cone beam view of region 122 at a view angle of 0° (axis 141 is parallel to the y-axis of coordinate system 42 ) for cone beam 138 . For clarity of presentation attenuation paths 150 are shown for only 13 columns 130 of detectors 132 , which columns define 13 axial planes AP ( FIG. 1 ) of cone beam 138 . The axial planes AP in FIG. 2 are optionally oriented at equally spaced azimuthal angles. FIG. 2 also shows projections 150 ′ of attenuation paths 150 and a projection SL′ of ellipses SL 0 , SL −1 (0°) and SL 1 (0°) on the xy-plane. Note that because cone beam 138 is assumed to be offset rotated, a projection 141 ′ of axis 141 of cone beam 138 is offset from the origin of coordinate system 42 and the axis is not coincident with the y-axis. A projection of isocenter 144 on the x-y plane is coincident with the origin of coordinate system 42 .
FIG. 3 schematically shows attenuation paths 160 for a cone beam parallel view of region 122 at a view angle of 0° and projections 160 ′ of the paths and projection SL′ of ellipse SL 0 on the xy-plane. Circle 161 lies in midplane MP 0 ( FIG. 1 ) of cone beam 138 and indicates a circle around which focal spot 136 moves as cone beam 138 rotates around isocenter 144 to acquire a cone beam views of region 122 at a plurality of cone beam view angles. Circle 161 ′ is a projection of circle 161 on the x-y plane. In the 0° parallel cone beam view, to moderate clutter, only ellipse SL 0 that lies on midplane MP 0 ( FIG. 1 ) is shown. To aid in visualization, a dashed line 166 connects all attenuation paths 160 defined by detectors 132 in a same row 128 ( FIGS. 4 and 5 ) of detectors 132 . Each dashed line 166 is labeled with the label of the detector row 128 that defines attenuation paths 160 that are connected by the dashed line. A parallel view for a particular row 128 of detectors 132 comprises line integrals for all attenuation paths connected by the dashed line 166 corresponding to the row of detectors. For example, for the 0° cone beam parallel view shown in FIG. 3 , the parallel view at 0° defined by detector row DR 1 comprises line integrals for attenuation paths connected by dashed line DR 1 .
FIG. 4 is similar to FIG. 3 , but schematically shows attenuation paths 170 and their respective projections 170 ′ for a parallel cone beam view at 315° (i.e. −45° in FIG. 4 , rotation is positive in the counterclockwise direction about the z-axis).
FIG. 5 schematically shows attenuation paths 180 , shown in dashed lines, for a cone beam parallel view at 180° superposed on attenuation paths 160 , shown in solid lines, for the 0° cone beam parallel view shown in FIG. 3 . Projections 160 ′ of attenuation paths 160 and projections 180 ′ of attenuation paths 180 on the xy-plane are also shown. Because cone beam 138 is offset rotated, projections 180 ′ are not coincident with the projections 160 ′ and instead “interleave” projections 160 ′.
Let a parallel view at a view angle φ for a detector row DR r (r being the subscript that denotes a particular row 128 shown in FIG. 1 ) be represented by PV(φ,r,s). Each parallel view PV(φ,r,s) comprises a set of samples at different discrete values of s for a Radon function R φ′ (r,s), where 0°≦φ′<180°, and φ′=φ mod 180°. Each parallel view PV(φ,r,s) comprises a number of samples for an associated Radon function R φ′ (r,s) equal to a number of detectors 132 in its associated detector row DR r . The argument s represents distance from isocenter 144 of a projection onto midplane MP 0 ( FIG. 1 ) of cone beam 138 of an attenuation path belonging to PV(φ,r,s). (In accordance with the convention that projections onto midplane MP 0 are projections onto the xy-plane, s is the distance of the projection of the attenuation path on the xy-plane from projection 144 ′ of isocenter 144 ′). The distance s is measured along a line, hereinafter referred to as a “Radon line”, “RL(φ′)” that is perpendicular to the projection and passes through isocenter 144 at the angle φ′ with respect to the x-axis.
FIG. 4 shows the Radon line RL(135°) (135°=315° mod 180°) for the parallel views PV(315°,−1,s), PV(315°,0,s) and PV(315°,1,s) comprised in parallel cone beam view at view angle 315° shown in the figure. The s coordinates of PV(315°,r,s) are the s coordinates of the intersections of projections 170 ′ with Radon line RL(135°). In FIG. 5 the common Radon line RL(0°) for cone beam parallel views at view angles 0° and 180° is coincident with the x-axis and the x-axis is therefore also labeled RL(0°) To determine values for the absorption coefficient of voxels in region 122 that are illuminated by X-rays in cone beam 138 , each parallel view PV(φ,r,s) is interpolated to replace the original set of line integrals that it contains with a set of line integrals evaluated at equally spaced values of s along the parallel view's Radon line RL(φ′). Let spacing between equally spaced values of the s-coordinate for which line integrals are interpolated be represented by Δs. Hereinafter, it is assumed that the line integrals in a parallel view PV(φr,s) are appropriately interpolated at equally spaced values of s.
FIG. 6 shows a schematic graph 190 of interpolated line integral values indicated by shaded circles 192 for a parallel view PV(φ,r,s) for φ=0°, r=1 and for s coordinates along Radon line RL(0°) shown in FIG. 5 , which is coincident with the x-axis. For orientation, a projection SL′ 1 of slice SL 1 ( FIG. 1 ) is shown on graph 190 . Values of line integrals for the parallel view PV(0°,1,s) are indicated with shaded circles 192 for s coordinates that are intersection points of lines 194 with the x-axis. Lines 194 schematically represent attenuation paths that pass through slice SL 1 at distances s from isocenter 144 for which interpolated line integral values 192 are determined. Isocenter 144 coincides with the origin of the x and y axis of graph 190 .
In some prior art methods for generating an image of region 122 from “interpolated line integral data” acquired by scanner 120 the data is processed using any of various 2D or 3D filtered back projection algorithms.
By way of example, for a “low resolution image” of region 122 , in accordance with some prior art 3D filtered back projection schemes, each interpolated parallel view PV(φ,r,s) is Fourier transformed to provide a Fourier transform “FR φ′ (φ,r,ω)” of the Radon function R φ′ (r,s) where,
FR φ ′ ( φ , r , ω ) = ∫ - ∞ ∞ PV ( φ , r , s ) exp ( - ⅈ ω s ) ⅆ s .
(Whereas a parallel view PV(φ,r,s) is a discrete set of data and integration of a parallel view is performed by summing, for convenience of presentation, integrals are used rather than sums.) Each function FR φ′ (φ,r,ω) is generally multiplied by the “Jacobian” filter |ω| and inverse Fourier transformed to provide a “filtered Radon function”
R φ ′ * ( φ , r , s ) = ∫ - ω N ω N F R φ ′ ( φ , r , ω ) exp ( ⅈ ω s ) ω ⅆ ω ,
where ω N is a Nyquist frequency that band limits the function FR φ′ (φ,r,ω). The Nyquist frequency is approximately equal to 1/(2Δs). Spacing Δs is proportional to a number of samples in each parallel view PV(r,φ,s), which is substantially equal to a number “N” of detectors in a row 128 of detectors. (The filtered Radon function at angle (φ′, R* φ′ (φ,r,s) has φ as an argument because as noted above, φ′=φ mod 180°. Therefore, there are two filtered Radon functions R* φ′ (φ,r,s) for each angle φ′, one generated from the interpolated parallel view PV(φ,r,s) and one generated from the interpolated parallel view PV(φ+180°,r,s)).
In the above discussion, a Radon function R φ′ (r,s) and its Fourier transform FR φ′ (φ,r,ω) are defined for a specific single value of r and that samples for the Radon function are acquired from parallel views PV(φ,r,s) having a same value of r as the Radon function. However, it is noted that a Radon function may be defined by samples provided by a plurality of parallel views PV(φ,r,s) having different values of r, i.e. a Radon function may be defined by samples provided by a plurality of detector rows 128 ( FIG. 1 ). For simplicity of presentation it is assumed that a Radon function is defined for a specific value of r and that its Fourier transform is defined by the integral noted at the beginning of the preceding paragraph.
For helical scan data, the functions R* φ′ (φ,r,s) that are used to determine a value for the absorption coefficient of a voxel located at coordinates (x, y, z) in region 122 are limited to a span of about 180°, i.e. for the functions R* φ′ (φ,r,s) that are used to determine a value for the absorption coefficient (φ L <φ<φ U where (φ U −φ L ) is equal to about 180°. The limitation to a span of about 180° is generally made to moderate “discordance” in the data caused by lack of coplanarity of views acquired in the scan and thereby possible image artifacts generated by such discordance. Each function R* φ′ (φ,r,s) is defined by samples from a single parallel view for which φ=φ′. The filtered Radon function R* φ′ (φ′,r,s) for the helical scan is therefore a low sampling rate function limited by the Nyquist frequency φ N that is determined by a number of samples in the single parallel view, i.e. the number of detectors 128 in a row 132 of detectors.
The functions R* φ′ (φ′,r,s) are generally interpolated responsive to the coordinates of the voxel using any of various 2D back-projection or 3D back-projection methods known in the art to define a function of angle φ′, R*(φ′,x,y,z), for the coordinates (x,y,z). If the absorption coefficient of the voxel is represented by ρ(x,y,z), then ρ(x,y,z) is determined by back projecting R*(φ′,x,y,z) in accordance with a relationship
ρ ( x , y , z ) = ∫ 0 π R * ( φ ′ , x , y , z ) ⅆ φ ′ .
Limiting view angles used to determine each absorption coefficient ρ(x,y,z) to a span of about 180°, tends to moderate artifacts in an image provided from the absorption coefficients that are generated by lack of coplanarity, “i.e. discordance”, of views acquired by cone beam 138 .
For an axial scan, the functions R* φ′ (φ,r,s) that are used to determine a value for the absorption coefficient of a voxel located at coordinates (x, y, z) in region 122 are limited to a span of about 360°, i.e. for the functions R* φ′ (φ,r,s) that are used (p L <φ<φ U where (φ U −φ L ) is about 360°. Each function R* φ′ (φ,r,s) is generally interpolated responsive to the coordinates of the voxel using any of various methods known in the art to define a function of angle φ′ and φ, R*(φ′,φ,x,y,z), for the coordinates (x,y,z). The functions R*(φ′,φ,x,y,z) are used to determine a function R*(φ,x,y,z). In order to moderate image artifacts that may arise due to the one beam angle a value for the function R*(φ′,x,y,z) for a given value of φ′ and given values for the spatial coordinates (x,y,z) is determined from a weighted average of R*(φ′,φ,x,y,z)| φ=φ′ and R*(φ′,φ,x,y,z)| φ=(φ′+180°) .
It is noted that even though for the axial case R*(φ′,x,y,z) is defined using parallel views in a 360° view angle span, R*(φ′,x,y,z) remains a “low frequency function” limited by the Nyquist frequency φ N , since the sampling frequency of each of the functions R*(φ′,φ,x,y,z) is about 1/(2Δs). As in the case for the helical mode ρ(x,y,z) is determined from R*(φ′,x,y,z) in accordance with the expression
ρ ( x , y , z ) = ∫ 0 π R * ( φ ′ , x , y , z ) ⅆ φ ′ .
A resolution of an image generated from values of ρ(x,y,z) is a function of the band limiting Nyquist frequency ω N . To an extent that ω N is larger, resolution of an image of region 122 improves. In prior art, to increase a sampling rate and thereby increase CON and improve a resolution of an image of region 122 , data from each parallel view PV(φ,r,s) and its “companion” parallel view PV(φ+180°,r,s) are combined to provide a “high sampling rate” set of line integrals for each Radon function R φ′ (r,s).
Since, optionally, cone beam 138 is offset rotated, s coordinates along a Radon line RL(φ′) for a parallel view PV(φ,r,s) are located between and equidistant from adjacent s coordinates along Radon line RL(φ′) for a “companion” parallel view PV(φ+180°,r,s). The line integrals for a parallel view PV(φ,r,s) are “interleaved” with the line integrals for a companion view PV(φ+180°,r,s). The parallel view PV(φ,r,s) together with its companion parallel view PV(φ+180°,r,s), when combined, provide twice as many samples and thereby double a sampling rate for the Radon function R φ′ (r,s) as does either parallel view alone.
By way of example, FIG. 7 shows a schematic graph 200 of line integral values for parallel view PV(0°,1,s) shown in FIG. 6 together with “interleaved” line integral values for the companion parallel view PV(180°,1,s). Values of line integrals for the parallel view PV(180°,1,s) are shown with un-shaded circles 202 for values of s coordinates at intersection points of dashed lines 204 with the x-axis.
Let the combined set of line integrals from a parallel view PV(φ,r,s) and its companion 180° parallel view PV(φ+180°,r,s) be referred to as a high resolution parallel view at angle φ and let the high resolution parallel view be represented by “HPV(φ,r,s)”. For both helical and axial scans, the sets of high resolution parallel views HPV(φ,r,s) are generally processed similarly to the manner in which low resolution parallel views PV(φ,r,s) generated from helical or axial scan data are processed to provide values for the absorption coefficient ρ(x,y,z) of region 122 .
Each function HPV(φ,r,s) is Fourier transformed to provide a high resolution Fourier transform “FR hφ (,r,ω)” of the Radon function R ω (r,s), where
FR h φ ( , r , ω ) = ∫ - ∞ ∞ HPV ( r , φ , s ) exp ( - ⅈ ω s ) ⅆ s .
The function FR hφ (,r,ω) is band limited by a Nyquist frequency equal to about 2ω N rather than ω N because each high resolution parallel view HPV(φ,r,s) comprises about twice the number of samples as each low resolution parallel view PV(φ,r,s). Each function FR hφ (r,ω) is filtered to provide a high resolution filtered Radon function
R h φ * ( r , s ) = ∫ - 2 ω N 2 ω N FR h φ ( r , ω ) exp ( ⅈ ω s ) ω ⅆ ω .
For a voxel at coordinates (x, y, z), for each angle φ the functions R* hφ (r,s) are processed to define a high resolution function R* hφ (x,y,z) and therefrom a high resolution value ρ h (x,y,z) for the absorption coefficient of the voxel where
ρ
h
(
x
,
y
,
z
)
=
∫
0
R
h
φ
*
(
x
,
y
,
z
)
ⅆ
φ
.
However, a parallel view PV(φ,r,s) and its 180° companion parallel view PV(φ+180°,r,s) that are used to provide a high frequency parallel view HPV(φ,r,s) are generally not coplanar (companion views are coplanar only for midplane views in an axial scan) and do not in actuality comprise samples of a same Radon function. As a result, an image, in accordance with prior art, of region 122 provided from ρ h (x,y,z) generally comprises an unsatisfactory level of artifacts.
In accordance with an embodiment of the present invention, to reduce artifacts and provide a high frequency image of region 122 an image of region 122 is provided by generating low frequency and high frequency “partial” images of the region and combining the two.
For the low frequency image, each parallel view PV(φ,r,s) is Fourier transformed to provide a Fourier transform FR φ′ (φ,r,ω) of the Radon function R φ′ (r,s) at angle φ′, where as in prior art
FR φ ′ ( φ , r , ω ) = ∫ - ∞ ∞ PV ( φ , r , s ) exp ( ⅈ ω s ) ⅆ s
(noting again that φ′=φ mod 180°). A low frequency filtered Radon function “LR* φ′ (φ,r,s)”, in accordance with an embodiment of the present invention, is then determined optionally using a low frequency filter f L (ω) in accordance with an equation,
LR
φ
′
*
(
φ
,
r
,
s
)
=
∫
-
ω
N
ω
N
FR
φ
′
(
φ
′
,
r
,
ω
)
exp
(
ⅈ
ω
s
)
ω
f
L
(
ω
)
ⅆ
ω
.
Low frequency filter f L (ω) has non-zero values for ω less than ω N and is equal to substantially zero for values of ω greater than ω N . Optionally f L (ω) is equal to substantially one for values of ω substantially less than ω N . The filter f L (ω), optionally adiabatically, decreases to zero at a value for ω, which is less than ω N , in a neighborhood of ω N .
For helical scan data, functions LR* φ′ (ω,r,s) that are used, in accordance with an embodiment of the present invention, to determine a value for the absorption coefficient of a voxel located at coordinates (x, y, z) in region 122 are limited to a span of about 180°, i.e. φ L <φ<φ U where (φ U −φ L ) is equal to about 180° and have φ=φ′. For a voxel located at coordinates (x, y, z) in region 122 , for each angle φ′, the functions LR* φ′ (φ′,r,s) are interpolated responsive to the coordinates of the voxel using any of various methods known in the art to define a function LR*(φ′,x,y,z) and a low frequency absorption coefficient ρ L (x,y,z) is determined for the voxel, where
ρ
L
(
x
,
y
,
z
)
=
∫
0
π
LR
*
(
φ
′
,
x
,
y
,
z
)
ⅆ
φ
′
.
For an axial scan, the functions LR* φ′ (r,φ,s) that are used to determine a value for the absorption coefficient of a voxel located at coordinates (x, y, z) in region 122 are limited to a span of about 360°, i.e. φ L <φ<φ U where (φ U −φ L ) is about 360°. Each function LR* φ′ (r,φ,s) is interpolated responsive to the coordinates of the voxel using any of various methods known in the art to define a function of angle φ′ and φ, LR*(φ′,φ,x,y,z), for the coordinates (x,y,z). The functions LR*(φ′,φ,x,y,z) are used to determine a function LR*(φ′,x,y,z). A value for the function LR*(φ′,x,y,z) for a given value of φ′ and given values for the spatial coordinates x,y,z is optionally determined from a weighted average of LR*(φ′,φ,x,y,z)| φ=φ′ and R*(φ′,φ,x,y,z)| φ=(φ′+180°) . The function LR*(φ′,x,y,z) is used to determine ρ L (x,y,z) as above with
ρ
L
(
x
,
y
,
z
)
=
∫
0
π
LR
*
(
φ
′
,
x
,
y
,
z
)
ⅆ
φ
′
.
The absorption coefficients ρ L (x,y,z) for voxels at different locations in region 122 are used, in accordance with an embodiment of the present invention, to generate a low frequency image “IM L (x,y,z)” of the region. For helical scan data the low frequency image is generally relatively free of artifacts because each of the parallel views used to determine ρ L (x,y,z), in accordance with an embodiment of the present invention, is provided from a span of view angles substantially less than 360° and optionally to a span of view angles about equal to 180°. For axial scan data the low frequency image is generally relatively free from artifacts as a result of the weighting procedure used to combine data from companion views to determine LR*(φ′,x,y,z).
For the high frequency image, for an axial or helical scan, to determine a value for the absorption coefficient of a voxel located at coordinates (x, y, z) in region 122 a high frequency parallel view, HPV(φ′,r,s) is defined for each view angle φ′ in a span of 180°. The high frequency parallel view HPV(φ′,r,s) comprises a set of line integrals from a parallel view PV(φ′,r,s) and its companion 180° parallel view PV(φ′+180°,r,s). (It is noted that in accordance with an embodiment of the present invention, data from a view angle span of about 360° is used to generate the functions HPV(φ′,r,s).) Each function HPV(φ′,r,s) is Fourier transformed to provide a high frequency Fourier transform “HFR φ′ (r,ω)” of the Radon function R φ′ (r,s), where
HFR
φ
′
(
r
,
ω
)
=
∫
-
∞
∞
HPV
(
φ
,
r
,
s
)
exp
(
-
i
ω
s
)
ⅆ
s
.
A high frequency filtered Radon function “HR* φ′ (r,s)”, in accordance with an embodiment of the present invention, is then determined from each Fourier transform HFR φ′ (r,ω) optionally using a “high-frequency” filter f H (ω). In symbols, high frequency filtered Radon function HR* φ′ (r,s) is defined by the equation,
HR
*
φ
′
(
r
,
s
)
=
∫
-
2
ω
N
2
ω
N
HFR
φ
′
(
r
,
ω
)
exp
(
i
ω
s
)
ω
f
H
(
ω
)
ⅆ
ω
.
High frequency filter f H (ω) is equal substantially to zero for values of ω substantially less than ω N and values of ω greater than 2ω N . Optionally f H (ω) is substantially equal to one for values of ω in a neighborhood of ω N . Optionally f H (ω) decreases adiabatically to zero at a value ω less than ω N . Optionally f H (ω) decreases adiabatically to zero at a value ω in a neighborhood of 2ω N . Optionally, the functions f H (ω) and f L (ω) are related by an expression f(ω)=f H (ω)+f L (ω) where f(ω) is equal substantially to one for values of ω substantially less than ω N and equal to substantially zero for ω greater than 2ω N . Optionally, f(ω) is equal substantially to one for values of ω in a neighborhood of ω N . Optionally, f(ω) decreases adiabatically to zero at a value of ω less than and in a neighborhood of 2ω N .
For the voxel located at coordinates (x, y, z), for each angle φ′, the functions HR* φ′ (r,s) are interpolated with respect to variables r and/or s responsive to the coordinates of the voxel using any of various methods known in the art to define a high frequency function of φ′, HR*(φ′,x,y,z). A high frequency value “ρ H (x,y,z)” for the absorption coefficient of the voxel is determined in accordance with the expression
ρ
H
(
x
,
y
,
z
)
=
∫
0
π
HR
*
(
φ
′
,
x
,
y
,
z
)
ⅆ
φ
′
.
In some embodiments of the present invention, for a voxel at coordinates (x, y, z) each parallel view PV(φ,r,s) in a 360° span of parallel view is converted into a high sampling rate parallel view by padding the parallel view with dummy, null value line integrals. A dummy line integral is added at each s value for which a companion view at (φ+180°) to the view at φ provides a line integral so that the dummy line integrals are interleaved with the real line integral values of the view at φ. By way of example, FIG. 8A shows a schematic graph 210 of line integral values 192 for parallel view PV(0°,1,s), which are shown in FIG. 6 , padded, in accordance with an embodiment of the present invention with dummy null value line integrals 212 indicated by circles enclosing an “X”. FIG. 8B shows a schematic graph 214 of line integral values 202 for parallel view PV(180°,1,s) which are shown in FIG. 7 , padded with dummy value line integrals 216 in accordance with an embodiment of the present invention. Each padded parallel view is separately processed similarly to the manner in which each high frequency parallel view HPV(φ,r,s) discussed above is processed.
Let a padded parallel view, in accordance with an embodiment of the present invention, be represented by PPV(φ,r,s). Each function PPV(φ,r,s) is Fourier transformed to provide a high frequency Fourier transform “PFR φ (r,ω)” of the Radon function R φ′ (r,s), where
PFR φ ′ ( φ , r , ω ) = ∫ - ∞ ∞ PPV ( r , φ , s ) exp ( - i ω s ) ⅆ s
(and as usual φ=φ′ or φ′+180°). The function PFR φ′ (φ,r,ω) is then filtered using the high frequency filter f H to generate a filtered “padded” Radon function PR* φ′ (φ,r,s), where
PR * φ ′ ( φ , r , s ) = ∫ - 2 ω N 2 ω N PFR φ ′ ( φ , r , ω ) exp ( i ω s ) ω f H ( ω ) ⅆ ω .
As above, the functions PR* φ′ (φ,r,s) are interpolated with respect to variables r and/or s responsive to the coordinates (x, y, z) of the voxel using any of various methods known in the art to define a high frequency function of φ′, PR* φ′ (φ,x,y,z). A high frequency filtered Radon function HR* φ′ (r,s) is defined by adding functions generated from companion parallel views at view angles φ′ and (φ′+180°). In symbols HR*(φ′x,y,z)=(PR* φ′ )(φ′,x,y,z)+PR* φ′ (φ′+180°, x,y,z)). The functions HR*(φ′,x,y,z) are then integrated to determine the absorption coefficient for the voxel in accordance with the expression
ρ
H
(
x
,
y
,
z
)
=
∫
0
π
HR
*
(
φ
′
,
x
,
y
,
z
)
ⅆ
φ
′
.
It is noted that the use of padded companion parallel views, in accordance with an embodiment of the present invention, for determining a high frequency filtered Radon function HR* φ′ (r,s) is possible, because all the steps involved in generating a filtered Radon function are linear. The inventors have found that it can be computationally simpler to pad views with zeros before filtering and combine data from companion views after filtering rather than combine data from companion views before filtering. For 3D back-projection schemes, first combining data from companion views PV(φ,r i ,s) and PV(φ+180°,r j ,s) for different combinations of {r i ,r j } and then filtering the combined data generally requires massive computational effort due to a very large number of possible combinations for {r i ,r j }.
The absorption coefficients ρ H (x,y,z) for voxels at different locations in region 122 are used, in accordance with an embodiment of the present invention, to generate a high frequency image “IM H (x,y,z)” of the region. The high frequency image is generally relatively free of artifacts because, high frequency components of the Fourier transform of the absorption coefficient generated from parallel views comprising data from view angle spans of about 360° do not generally generate artifacts.
A high resolution image “IM HR (x,y,z)” for region 122 relatively free of artifacts is provided, in accordance with an embodiment of the present invention, from the low frequency image IM L (x,y,z) and the high frequency image IM H (x,y,z), where IM HR (x,y,z) is defined by an equation IM HR (x,y,z)=IM L (x,y,z)+αIM H (x,y,z). In the expression for IM HR (x,y,z) α is a weighting factor that determines how much of the high spatial frequencies contribute to IM HR (x,y,z) and thereby a sharpness and resolution of the image IM HR (x,y,z). In accordance with an embodiment of the present invention, the weighting factor α is adjusted in real time during imaging of a region of a patient to increase or decrease sharpness of the image.
Whereas the above exemplary methods for processing cone beam data, in accordance with an embodiment of the present invention, employ 3D back projection, practice of the present invention is not limited to algorithms that employ 3D back projection. For example, the inventor has found that as a cone angle of a cone beam increases, 2D back projection methods for processing cone beam data that combine 180° companion views to provide high resolution images tend to generate more artifacts in the images. Artifacts in a high resolution image of a region generated by a “high resolution” 2D back projection algorithm can be mitigated, in accordance with an embodiment of the present invention, by generating low and high frequency partial images of the region using the 2D back projection algorithm. The high and low frequency partial images are then combined, in accordance with an embodiment of the present invention, to provide a high resolution image. As in the exemplary methods discussed above, the low frequency partial image is generated from parallel views comprising data from view angle spans of about 180° for helical scan data and by averaging data from companion views in a view angle span of about 360° for axial scan data. The high frequency partial image is generated from companion views combined to provide parallel views comprising data from view angle spans of about 360°.
FIG. 9 shows a flow chart 220 of a method of generating a CT image of a region from line integral data of the region, in accordance with an embodiment of the present invention.
In a block 222 line integral data for the region is acquired. In a block 224 low spatial frequency components of a Fourier transform of the image are determined from the data and in a following block 226 the low frequency components are filtered and back projected to generate a low frequency image of the region. Optionally, filtering comprises filtering the low frequency data with a low frequency filter f L (ω).
In a block 228 high spatial frequency components of the Fourier transform of the image are determined from the data and in a following block 230 the high frequency components are filtered and back projected to generate a high frequency image of the region. Optionally, filtering comprises filtering the high frequency data with a high frequency filter f H (ω).
In a block 232 the low frequency and high frequency images are combined to provide an image of the region. Optionally, combining the low and high frequency images comprises weighting the images.
It is noted that whereas in the above discussion “offset data” is generated by offset rotating an X-ray beam, offset data can be generated using methods known in the art by using multiple X-ray sources. By way of example, U.S. Pat. No. 4,637,040, the disclosure of which is incorporated herein by reference, describes acquiring CT attenuation data using “at least two distinct point sources for emitting radiation”. Methods in accordance with embodiments of the present invention for generating images from offset rotated data are applicable as well to processing multiple X-ray source data.
In the description and claims of the present application, each of the verbs, “comprise”. “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.
The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the present invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments will occur to persons of the art. The scope of the invention is limited only by the following claims.
|
CT scanner is disclosed for providing an image of a region comprising: at least one X-ray cone beam for illuminating mthe region with X-rays; a plurality of rows of X-ray detectors that generate signals responsive to line attenuation of X-rays from the at least one controller that controls providing an image of a region comprising: at least one X-ray cone beam for illuminating the region with X-rays; a plurality of rows of X-ray detectors that generate signals responsive to line attenuation of X-rays from the at least one X-ray source that pass through the region; a controller that controls the at least one X-ray cone beam to acquire line attenuation data for the region for different view angles of the region; and a processor that receives the signals and: a) determines low spatial frequency components of the image from the data; b) generates a first spatial image of the region from the low high spatial frequency components of the image from the data; d) generates a second spatial image of the region from the high frequency components; and e) combines the first and second images to generate the CT image.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to copending U.S. provisional application entitled, “Enhanced Nail Clippers,” having Ser. No. 60/644,674 filed Jan. 18, 2005, which is entirely incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to nail clippers. More specifically, the invention relates to nail clippers for animals, such as dogs and cats.
DESCRIPTION OF THE RELATED ART
[0003] Some animals, such as dogs, have veins present in the center and toward the base of their nails. If an owner or groomer accidentally cuts the quick of the nail (the vein), not only does it cause the animal pain, but the wound bleeds profusely. For animals with light colored nails, the quick can often be seen with the naked eye. For animals with dark colored nails it is very difficult to see where the quick ends. It is important to cut an animal's nail as close to the quick as possible because the quick will grow over time if the nails are not cut back filly. To shorten the quick the animal must be anesthetized and all the nails cut to the base and through the quick.
[0004] Nail clippers are available today that use an adjustable stop that limit the amount of nail that is cut off. This prevents the user from cutting the quick only if they know exactly how much to cut off. If the guard is set to a length that is safe on one nail it may not be safe on another nail. Animals' nails grow and wear differently even on the same foot/paw.
[0005] Another type of clipper that attempts to deal with this issue clips the nail based on diameter. That method assumes that the quick ends where the nail is at a specific diameter. Although this may help keep the user from cutting the nails too short, it does not identify the location of the quick and, thus, the possibility of either cutting the quick or leaving the nails too long remains.
[0006] U.S. Pat. No. 6,220,251 to Jeong et al. (hereinafter “Jeong”), entitled Combination Vision Enhancement Kit and Nail Clipper, illustrates a conventional nail clipper with accompanying lens to magnify the respective cutting area. Furthermore, the Jeong patent teaches a light source that could further be used to enhance the field of view (See Col. 2, lines 45-53) by illuminating the general viewing area. The Jeong patent is generally focused on nail clippers to be used for human nails, and so fails to recognize the need to clip animal nails as close to the quick as possible.
[0007] As such, there remains an unsatisfied need in the market for nail clippers that better provide for clipping animals' nails, given the unique features of such nails as just previously mentioned.
SUMMARY OF THE INVENTION
[0008] Various embodiments of the present invention are illustrated in the present disclosure. A first embodiment of the present invention is a system for enhancing the clipping of a nail. The system comprises a lighting element for transilluminating the nail, a power supply for powering the lighting element, and a switch for activating the lighting element.
[0009] A second embodiment is a nail clipper that includes a lighting element coupled to a first reciprocating blade. The lighting element is positioned to transilluminate a patient's nail.
[0010] A third embodiment is a system for enhancing the clipping of a patient's nail. The system comprises means for transilluminating the patient's nail such that the quick of the nail becomes better visible.
[0011] A fourth embodiment is a method for better manicuring an animal's nail. The method includes: aligning a lighting element to a target nail such that the target nail is transilluminated to visually expose the location of the animal's quick; positioning a cutting instrument to a desirable location, relative to the quick, of the target nail; and cutting the target nail with the cutting instrument.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0013] FIG. 1 is an illustration of a conventional pet nail clipper.
[0014] FIG. 2A is an illustration of a pet's nail when not illuminated by a device embodying the present invention.
[0015] FIG. 2B is an illustration of a pet's nail when transilluminated by a device embodying the present invention.
[0016] FIG. 3 is a perspective view illustrating an embodiment of an enhanced nail clipper system in accordance with the present invention.
[0017] FIG. 4A is a perspective view illustrating a first embodiment of an enhanced nail clipper in accordance with the present invention.
[0018] FIG. 4B is a perspective view illustrating a second embodiment of an enhanced nail clipper in accordance with the present invention.
[0019] FIG. 5 is a perspective view illustrating a third embodiment of the enhanced nail clipper in accordance with the present invention.
[0020] FIG. 6 is a perspective view illustrating a fourth embodiment of the enhanced nail clipper in accordance with the present invention.
[0021] FIG. 7 is a block diagram illustrating a novel method for grooming an animal's nails in accordance with the present invention.
DETAILED DESCRIPTION
[0022] Referring now in more detail to the drawings, in which like numerals indicate corresponding parts throughout the several views, FIG. 1 illustrates a conventional nail clipper 1 used to cut an animal's nails. The nail clipper 1 is generally comprised of a pair of cutting blades 2 and 3 , each with a cutting edge 4 and 5 , positioned reciprocate of each other. A handle 8 is coupled to the pair of cutting blades 2 and 3 . A bolt 6 is used to couple the blades 2 and 3 and to pivot in a first plane. A biasing spring 7 can also be included to bias the handles 8 in an open position. In some cases, the biasing spring 7 may be excluded.
[0023] Typically, the cutting blades 2 and 3 are composed of hardened metal, sharpened at the edges 2 and 3 . The handle 8 can be composed of a hardened plastic, rubber, metal, or wood.
[0024] In practice, the nail clippers 1 function very similar to a pair of scissors. A user places the target nail between the cutting edges 4 and 5 , grips the handle 8 , and squeezes to cause the cutting edges 4 and 5 to come together and clip the target nail.
[0025] FIG. 2A is an illustration 10 of an animal's nail when not illuminated by a device embodying the present invention. A nail 13 protrudes from a toe 12 . Often, the nail 13 will curve as it grows out from the toe 12 . A pad 14 is often found on the bottom of the toe 12 .
[0026] FIG. 2B is an illustration 20 of a pet's nail 23 when transilluminated by a device embodying the present invention. Similar to the nail 13 of FIG. 2A , nail 23 grows from the toe 22 , and tends to curve downward as it grows. When transilluminated by a light source, that is when illuminated to reveal the interior of the nail 13 , the quick 26 becomes viewable. A target cutting area 27 is beyond the tip of the quick 26 .
[0027] FIG. 3 is a perspective view illustrating an embodiment of an enhanced nail clipper system 100 in accordance with the present invention. Enhanced nail clipper system 100 is illustrated as mounted or affixed to a conventional nail clipper 101 . In this case, the system 100 may be an aftermarket product and retrofitted to one of a number of nail clipper models.
[0028] The first embodiment of the enhanced nail clipper system 100 includes a lighting element 115 confined within a lighting housing 110 . The lighting housing 110 , in this embodiment is mounted atop a first blade member 102 and positioned in such a way as to transilluminate a target nail when placed between the cutting edges 104 and 105 of the nail clipper 101 .
[0029] The lighting element 115 is powered by a wire lead 120 running from the lighting housing 110 to a toggle switch 130 . In this case the toggle switch 130 is mounted on an interior portion of the handle 108 of the nail clipper 101 . The toggle switch 130 is wired to a power supply 140 .
[0030] The lighting element 115 could utilize a number of illumination technologies. Light emitting diodes (LEDs), incandescent, and laser are all types of lighting elements that could be used to transilluminate the target nail. It should be construed by those having ordinary skill in the art that any of these lighting technologies mentioned and those not mentioned could be utilized and should be broadly captured as a lighting element 115 . All such embodiments should be included within the scope of the present invention without departing from the spirit of the invention.
[0031] The particular footprint of the lighting housing 110 is beyond the scope of the present invention. The housing 110 can be mounted or affixed to the cutting blade 102 in a number of ways including by adhesive, such as glue or epoxy, or magnetically. The manner and approach in which the housing 110 is affixed to the cutting blade 102 is generally beyond the scope of the present invention.
[0032] There are a number of on/off type switches known in the art that could be used as the aforementioned toggle switch 130 . Some examples of switches include: push button on/off switches, dip switches, compression switches, motion-sensitive switches, membrane switches, capacitive switches, and rotary switches. It should be construed by those having ordinary skill in the art that any of these switching technologies mentioned and those not mentioned could be utilized and have been broadly defined as a toggle switch 130 . All such embodiments should be included within the scope of the present invention.
[0033] Power supply 140 could be any of a number of power supplies, such as a potential energy source (battery) or kinetic energy converter. The particular power generation technology is beyond the scope of the present invention. The power supply 140 , although illustrated as being integrated with the handle 108 of the nail clippers 101 , could be positioned in a number of ways. For example, the power supply 140 (and switch 130 ) could be integrated in with the lighting housing 110 to comprise one single element. The particular positioning and the particular type of power supply are beyond the scope of this embodiment of the present invention
[0034] In practice, a user turns on the system 100 , by toggling the switch 130 to an on position. A target nail is positioned between the cutting edges 104 and 105 of the clippers 101 such that the lighting element 115 transilluminates the matter comprising the target nail. Upon locating the quick, the user can align the cutting edges 104 and 105 accordingly, and make an accurate cut.
[0035] FIG. 4A is a perspective view illustrating a first embodiment of an enhanced nail clipper 200 in accordance with the present invention. In this embodiment, a lighting element 215 and its accompanying housing 210 are integral with the nail clipper 200 . In this embodiment, the lighting housing is mounted to a cutting blade 202 of the clipper 200 . In alternative embodiments, the lighting element 215 may be housed elsewhere, such as in the handle 208 of the clippers 200 , and a fiber optic cable and/or some other lighting conduit, such as a lightpipe, could be used to direct light to the appropriate position relative to the cutting edges 204 and 205 . The lighting element 215 could also be placed on the outside edge of the cutting element so that it shines on both sides of the blade 202 .
[0036] FIG. 4B is a perspective view illustrating a second embodiment of an enhanced nail clipper 250 in accordance with the present invention Nail clipper 250 is based upon a second type of animal nail clipper prevalent in the market today. Nail clipper 250 , is comprised of a first handle 258 and a second handle 259 that are movable with respect to each other in a first plane of motion in order to provide relative movement between a first cutting blade 252 and a stationary anvil 253 . Cutting blade 252 moves with respect to anvil 253 in a second plane of motion, which in this embodiment, is substantially perpendicular to the first plane of motion.
[0037] Stationary anvil 253 is molded such that a hole exists 251 . The hole 251 is positioned to receive a target nail, whereby the first cutting blade 252 will sweep across and cut the target nail when the first and second handles 258 and 259 are squeezed together. A biasing spring (not shown) may be positioned between the first and second handles 258 and 259 to bias the clipper 250 in an open position.
[0038] Nail clipper 250 further includes a lighting element 265 positioned relative to the hole 251 so as to transilluminate the medium of the target nail. Lighting element 265 is placed within a lighting housing 260 which is affixed and/or integrated with the stationary anvil 253 . A wire 270 is illustrated in this embodiment, which is used to deliver power to the lighting element 265 from a power source (not shown).
[0039] FIG. 5 is a perspective view illustrating a third embodiment of the enhanced nail clipper 300 in accordance with the present invention. Again, a conventional nail clipper is the basis of the enhanced nail clipper 300 . Nail clipper 300 includes handles 308 coupled with opposing cutting blades 302 and 303 , each with cutting edges 304 and 305 . When the handles are squeezed together, the cutting edges, 304 and 305 , close against each other in a first plane, thus cutting a target nail. A biasing spring 307 can be used to bias the handles 308 in an open position.
[0040] Enhanced nail clipper 300 includes a lightpipe 310 positioned to transilluminate a target nail to be positioned by the user between the cutting edges 304 and 305 . A fiber optic cable 320 , or some other means, is used to direct light from a lighting element 350 to the lightpipe 310 . The lighting element 350 , in this embodiment, is embedded in a cavity 309 of one of the handles 308 .
[0041] Coupled to the lighting element 350 is a push-button switch 330 . A power source 340 is also housed within the cavity 309 . Certain electronic components 345 , such as diodes or resistors can also be found in the cavity. The push-button switch 330 can protrude from the handle 308 , such that the user can turn on and off the lighting element 350 when desired. Again a number of switching technologies could be used without departing from the spirit of the present invention.
[0042] FIG. 6 is a perspective view illustrating a fourth embodiment of the enhanced nail clipper 400 in accordance with the present invention. Enhanced nail clipper 400 is similar to that of FIG. 4A , wherein a lighting element 415 is positioned relative to the cutting edges 404 and 405 to transilluminate a target nail. Lighting housing 410 is mounted or integrated with a cutting blade 402 . A cavity 409 in one of the handles 408 houses a power source 440 and possibly some discrete electronic components 445 . Enhanced nail clipper 400 further includes a compression switch 430 to control power being delivered to the lighting element 415 .
[0043] The compression switch 430 is comprised of first and second contact points 431 and 432 , mounted reciprocal each other on an interior portion of the handle 408 . A spring 433 is coupled to one of the contact points. When the handles are squeezed together, the spring 433 comes into contact with both contact points, thus completing a circuit and delivering power to the lighting element 415 . Not shown is a biasing spring which may be mounted between the handles 408 and exclusive of the compression switch 430 .
[0044] FIG. 7 is a block diagram illustrating a novel method 500 for grooming an animal's nails in accordance with the present invention. The method 500 begins by aligning a lighting element with a target nail so as to transilluminate the nail, thus exposing the quick (step 510 ). This can be accomplished in a number of ways, such as those illustrated in previous figures. Other conceived methods of accomplishing this step are by placing a light source, not part of the nail clipper, in a position such that the target nail is transilluminated. Such a light could be a desk lamp or a light source integrated with the procedure table.
[0045] The method 500 continues by positioning the cutting instrument along the target nail so as to cut off the desired length while not cutting the quick (step 520 ). The quick is now viewable by way of step 510 . The method 530 proceeds with cutting the target nail 530 .
[0046] It should be emphasized that the above-described embodiments of the present invention, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of the present invention and protected by the following claims.
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Systems, methods, and devices for better manicuring a patient's nails are disclosed. A representative embodiment is a system that includes a lighting element for transilluminating the nail, a power supply for powering the lighting element, and a switch for activating the lighting element.
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BACKGROUND OF THE INVENTION
Field of the Invention
The present application relates to medical diagnostic apparatus for introducing a high intensity light beam into a fiber optic cable.
Description of Related Art
Fiber optic cable illumination apparatus is used for medical diagnostic purposes wherein a focused lamp supplies light to an optic cable interface. Such devices operate most efficiently when the proper lamp is properly focused. However, present units permit improper lamps to be substituted during lamp replacement. Additionally, present illumination apparatus requires manual electrical connections be made during lamp replacement necessitating a higher degree of skill by the operator than is desirable.
Fiber optic systems are known to have inefficient light introduction interfaces due to the spaces between the fibers which contribute little to the interface when the light source impinges directly upon them. Also, due to the contour of the light beam impinging on the flat, planar fiber ends, an effect known as Newtonian ring interference causes rings of color light to appear at the cable output which reduces the illumination quality of the cable bundle. Known illumination apparatus have not effectively overcome this phenomenon.
OBJECTS OF THE INVENTION
In view of the foregoing deficiencies of medical illumination apparatus, it is an object of the invention to provide a more powerful and efficient high intensity light source for the transmission of light by means of fiber-optical cables.
A further object of the invention is to provide an essentially pure white light for fiber-optical cable transmission and to provide a more efficient application of light to a fiber optical cable interface.
Yet another object of the invention is to provide a method of preventing electrical shock to personnel servicing the lamp assembly when the lamp supporting drawer is extended and to insure proper electrical connection to the lamp assembly before energizing the lamp electrical connections.
A further object of the invention is to provide a lamp replacement system for medical diagnostic apparatus which substantially eliminates the likelihood of improper lamps being installed through the use of an electrical interlock which completes the circuit to the lamp only upon the proper lamp being properly positioned with respect to the optical cable interface.
SUMMARY OF THE INVENTION
These objects are accomplished, in part, through the novel use of an internally focused metal halide arc lamp as a light source for medical diagnostic illumination apparatus. The halide arc lamp provides a significantly greater light intensity than a comparable wattage incandescent lamp. Additionally, the halide arc lamp provides light of a multi-color spectra through a differential reflector focusing configuration such that the light quality at the focal beam is adjusted to achieve an exceptionally intense white light which is superior for purpose of illumination in the medical field wherein the light source is distributed through fiber optic cables.
It has been found that among the problems attendant with fiber optic light transmission technology is the inefficient transmission of light into the cables through the fiber optic cable interface and the presence of Newtonian interference rings at the cable output. The invention employs a metal halide arc light having a focused output beam having an axis, the focal point of the beam is directed to impact at the fiber optic cable interface and the beam axis is at an angle of about 10° relative to the cable interface axis. This angle increases the amount of light carried through the cable through enhancement of the acceptance angle of the converging beam to the end of the cable bundle while also minimizing the Newtonian ring interference at the light output.
In order to avoid potential shock hazard, the circuit to the bulb power receptacles located in the housing and the bulb connectors mounted on a slidable drawer supporting the lamp is interrupted when the drawer is opened to expose the lamp for replacement purposes. The electrical circuit to the lamp is automatically restored when the drawer is closed.
Further, the apparatus includes an interlock feature located on a bracket directly attached to the proper lamp and when a proper lamp and bracket are installed, an interlock tab defined on the lamp mounting bracket closes an electrical interlock switch when the bracket is properly positioned which completes the circuit to the bulb power receptacles. This unique tab interlock is such that improper lamps placed within the bracket cannot activate the unit, nor can the electrical interlock switch be inadvertently activated through other means.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of medical diagnostic illumination apparatus in accord with the invention having a lamp supporting drawer partially extended from its cabinet enclosure,
FIG. 2 is an enlarged detail cut-away perspective view of the cabinet and drawer as viewed from the drawer outer side,
FIG. 3 is an enlarged plan detail cut-away view showing the lamp bracket interlock switch assembly,
FIG. 4 is a elevational detail view, partly in cross-section, showing the bracket interlock tab engaging the interlock switch, the insulator columns being omitted for purposes of illustration,
FIG. 5 is a front elevational view of the lamp bracket, per se,
FIG. 6 is a rear elevational view of the lamp bracket partially inserted into the lamp bracket holder per se, the insulator columns not being illustrated,
FIG. 7 is a elevational detail side view, partially in cross-section of the heat sink and lamp assembly, the insulator columns and lamp bracket holder being omitted for purpose of illustration,
FIG. 8 is a detail plan view, partially in section, of the drawer face and lamp assembly, the lamp bracket holder being omitted for purpose of clarity,
FIG. 9 is a detail plan view of the lamp assembly lamp plugs in engagement with the floating receptacle bracket when the drawer is closed,
FIG. 10 is an elevational detail sectional view of the connector system showing lamp plug engagement with the floating receptacle bracket when the drawer is closed, the lamp components and the lamp bracket holder being omitted for purpose of illustration
FIG. 11 is an elevational view of the lamp assembly and bracket, per se, the insulator columns being omitted for purpose of illustration,
FIG. 12 is an enlarged detail elevational view of the floating lamp connector, partially in section, and
FIG. 13 is an elevational view of the floating receptacle connector member as taken along 13--13 of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A medical diagnostic fiber optic light source apparatus for the supplying of light for illumination to a fiber optic cable interface utilizing the invention is generally indicated at 10 of FIG. 1, and the light source apparatus includes a cabinet housing 12 with a slidingly insertable drawer 14 adapted to facilitate component maintenance. Inside the housing 12 is a standard power supply, not shown, which provides electrical power to the drawer circuitry.
When the drawer 14 is extended from the cabinet front opening compartment 16, the resulting exposed, energized electrical surfaces pose an electrical shock hazard which is avoided in the invention by using a separating connector system, as illustrated in FIG. 10, which automatically electrically disconnects an installed 250 watt focused beam metal halide arc lamp 18, as the drawer is withdrawn from the cabinet.
The separating connector system comprises two power connector pins 20 on standoff insulators 22 which horizontally extend from a vertically mounted lamp bracket 24 with a bridging insulative spacing member 26 between them. Electrical connection between the pins 20 and the metal halide arc lamp 18 are made by wires 28 extending from a lamp base connector 30 and a second lamp terminal 31 to solder pads on the spacing member 26 in electrical connection with the power connector pins 20. These rigidly extending pins 20 make connection with two complementary aligned, longitudinally spaced radially floating sleeve connectors 32 mounted upon and through an opposing insulated cabinet mounted receptacle bracket 34 when the lamp bracket 24 is correctly seated in the lamp bracket holder 36 which is fixed to the drawer 14.
The cabinet receptacle bracket 34 is fabricated of a durable insulating material such as nylon secured by screws 38 to a contiguous cabinet mounting plate 40, FIG. 2. While the preferred embodiment employs enlarged sleeve connector mounting holes 33 in the bracket 34 which cooperate with floating sleeves connectors 32 and their associated connector nuts 42 which are secured in a spaced relationship to the bracket 34, it is anticipated that other locations and connector types may be substituted for the configuration of the preferred embodiment without departing from the inventive concepts. The space 44 between the bracket and the floating sleeve connectors allows the sleeve connectors 32 to axially pivot thereby facilitating alignment with the pins 20 which enables the drawer to be closed and the electrical connections made in spite of any relatively minor pin and sleeve connector misalignment which may exist. Electrical connection is made to the sleeve connectors 32 by means of a ring lug connector terminated wire 46 which is secured between the two connector nuts 42 and to which electrical current is supplied by the power supply, not shown.
An interlock switch 48 prevents power supply energization unless the arc lamp bracket 24 is properly in place as is sensed by the cooperation of a lamp bracket interlock tab 50 with the interlock switch plunger 52. The lamp bracket lower edge 54 engages the lamp bracket holder bottom flange 56 when the bracket 24 is fully inserted, as illustrated in FIG. 2. As seen in FIG. 6, the lamp bracket side edges 58 slidingly engage spaced lamp bracket holder guide tabs 60, homogeneously formed of the bracket holder material, thereby assuring proper lamp bracket alignment as the bracket 24 is inserted into the guide tabs 60 for parallel mounting upon holder 36. Should improper bulb installation occur, the power connector pins 20 will not align with and engage the cabinet floating sleeve connectors 32 thereby preventing power from being applied to the lamp 18. Furthermore, the bracket interlock tab 50, an extension of the lamp bracket 24, will ensure that the floating sleeve connectors 32 will be activated only if the lamp 18 is correctly in place prior to closing the lamp drawer 14. The tab construction is such that other bulbs placed within the unit cannot activate the unit, nor can the unit be activated by another means. When the lamp bracket 24 is properly fully seated in the lamp bracket holder 36, the interlock tab 50 extends downward through a drawer interlock hole 62, FIG. 4, which is mounted on the drawer bottom surface 64 adjacent and beneath the lamp bracket holder.
The interlock switch 48 is mounted to the lower surface to the drawer bottom 64 in a longitudinal orientation. The plunger 52 longitudinally extends from the interlock switch 48 to a position beneath the drawer interlock hole 62 and the plunger end is beveled to provide a cam surface engageable by tab 50 which axially displaces the plunger when the lamp bracket 24 is correctly and fully seated. The interlock switch 48 interrupts the electrical power to the cabinet power supply if the arc lamp 18 is not installed or is improperly installed thereby assuring safe operation.
The mounting alignment and location of metal halide lamps is critical for the proper application of highly focused light onto the associated fiber optic bundle. By using an interlock tab 50 in conjunction with the square lamp bracket holder 36 and bracket holder guide tabs 60, the lamp assembly is not only positioned laterally, but is also maintained in the preferred square, vertical position by the engagement of the lamp bracket top flange 70 and the bracket holder top edge 55.
The employment of an internally focused beam high intensity metallic halide arc lamp in accord with the invention provides a white light for illumination which is less prone to affect target color appearance than one of a yellow hue, and to the inventors' knowledge, such lamps have not been used previously with medical diagnostic apparatus. The light output of a metal halide arc lamp is a consequence of the process by which a differential reflector focusing technique is applied to the light of multiple color spectra such that the light quality at the focal beam is adjusted to achieve white light. Furthermore, the lamp provides significantly greater light intensity for a given wattage bulb than that which can be attained with an incandescent lamp.
The invention anticipates that in order to use a metal halide arc lamp a special configuration must be employed in order to provide enhanced performance, acceptable service life and economical construction. One of the critical factors associated with the very high intensity of metal halide lamps is the characteristically great amount of lamp heat generated by the lamp's operation, and specifically present in the light beam at its focal point 72, FIGS. 7 and 8. In order to safely dissipate the arc lamp heat and minimize thermal stresses to the system components, three techniques are used.
First, by employing a member interposed between the arc lamp 18 and bracket 24 which will allow for thermal expansion of the lamp and components coming in contact with it, mechanical stresses to the components can be minimized thereby increasing service life. Such a member's effectiveness in minimizing stresses can be further enhanced if it has good insulative qualities. In the preferred invention, spacers 74 are interposed between an annular circumferential ceramic halide arc lamp collar 76 and the lamp bracket 24. The halide arc lamp collar 76 is interposed adjacent to the lamp face 78 and spaced from the lamp bracket 24 to minimize drawer face heating. The spacers 74 in this configuration serve several purposes: a) they remove the lamp face from the bracket; b) they provide a means of adjustment for lamps having diverse focal points; and c) by using spacers of diverse selected lengths, the focused lamp beam axis and bundle interface angle can be varied to enhance the bundle interface angle of acceptance.
The support of the halide arc lamp on the bracket 24 is completed by fixing the halide lamp intermediate the collar spacers 74 and four washers 86 mounted on spaced standoff insulators 82. Each standoff insulator 82 is mounted upon and extends from the lamp bracket 24 alongside the lamp collar 76 and is secured with a screw 84 to securely clamp the arc lamp 18 into place between a spacer 74 and a washer 86 as can be appreciated by reference to FIG. 9.
Secondly, a vaned heat sink 88 is placed intermediate the lamp bracket holder 36 and the drawer face 90, which has a central aperture 92 for passage of the lamp light beam 94 through the heat sink 88 to the fiber optic bundle interface 80, FIG. 8. Air is constantly forced over the heat sink 88 by a fan within cabinet 12 discharging air through port 95, FIG. 1, thereby keeping drawer face 90 temperatures within an acceptable range.
Thirdly, the drawer face heating due to arc lamp radiation is also minimized by the orientation of the lamp beam axis at an approximately 10° horizontal angle relative to the face plane and bundle central axis 96, as seen in FIG. 8, which allows proper application of the light to the fiber optic interface yet minimizes the heat applied to the forward face of the drawer and the enclosure.
The most important benefit of angling the arc lamp to the optic bundle axis is an increased efficiency of light transferred to the bundle from the beam focal point 72 at the bundle interface 80. In using metal halide arc lamps in conjunction with fiber optic cables, it has been found that by directing the light to the bundle interface at an angle, rather than in alignment with the bundle axis, a more efficient transfer of light results due to enhancement of the acceptance angle of the converging beam to the end of the bundle, consequently, more light is transferred to and carried through the bundle. It has been determined that by deviating the lamp beam axis between 8° and 12° from the optic fiber bundle axis optimum improved results are achieved, and preferably, a 10° angle deviation is employed.
Newtonian ring interference patterns normally occur which degrade the output light quality from fiber optic cables. Newtonian rings are caused by light interference from the contact of the conical light wave's spherical front when it contacts the planar fiber optic fiber interface. The invention's significant advancement to the art of angling the arc lamp as previously described improves the quality of light at the bundle output by the minimization of Newtonian ring interference patterns.
A turret assembly 98 is located on the drawer face 90 which is rotatable and selectively aligns the fiber optic interface of one of several sizes of fiber optic cables with the aperture 92, the appropriate size of cable may be inserted in the correspondingly sized connection sleeve 102. The cables are secured by set screws 106 installed on each of the several turret connection sleeves 102.
It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention.
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The invention pertains to a fiber optic lamp system such as those employed in medical diagnostic systems using a cabinet containing a power supply having a front extendible drawer containing a 250 watt focused beam metal halide arc lamp mounted in a removable bracket which includes a sensing tab extension. The bracket sensing tab operates an electrical interlock switch when the proper lamp is properly installed. The interlock switch controls power to the system whose circuit includes pin and floating sleeve electrical connectors which automatically directly completes the circuit to the arc lamp upon the drawer being closed. The amount of light transferred to the fiber optic cable is optimized by offsetting the axis of focused light with respect to the optic cable axis at the cable interface.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid crystal display device (hereinafter LCD), more particularly to an LCD having a wide viewing angle without color shift.
2. Background of the Invention
An LCD has the characteristics of light weight, thin thickness and low power consumption. It has been used in various information display terminals or visual equipment. The major operating mode for the LCD can be the twisted nematic(“TN”) and the super twisted nematic(“STN”). Though they are presently commercially used in various LCD means, the characteristic of narrow viewing angle has still remained unsolved.
An In-Plane Switching(IPS) mode LCD has been suggested to solve the foregoing problems.
FIG. 1 is a plane view showing a general IPS mode LCD. A common electrode 11 is formed on the substrate 10 in the form of comb. A pixel electrode 13 is also formed on the substrate 10 in the form of comb, the comb-like electrodes 11 and 13 form a teeth shape. When an external voltage is applied between the common electrode 11 and the pixel electrode 13 , an electric field F 1 is formed therebetween and the liquid crystal molecules 15 are moved such that their long axes are parallel to the electric field F 1 .
There is a color shift in the direction of long and short axes due to the optical anisotropy since the long and short axes of liquid crystal molecule are different from each other in length.
As well known, the refractive anisotropy(or birefringence, Δn) has occurred due to the difference of the lengths of the long and the short axes. The refractive anisotropy(Δn) is also varied from the observer's viewing directions. Therefore a predetermined color is appeared on the region where the polar angle if 0 degree and the azimuth angles range of degrees 0, 90, 180 and 270 in spite of the white state. This results in color shift and more detailed description thereof is attached with reference to the equation 1.
T≈T 0 sin 2 (2χ)·sin 2 (π·Δnd/λ) equation 1
wherein,
T : transmittance;
T 0 : transmittance to the reference light;
χ: angle between an optical axis of liquid crystal molecule and a polarizing axis of the polarizing plate;
Δn: birefringence;
d: distance or gap between the upper and lower substrates(thickness of the liquid crystal layer); and
λ: wavelength of the incident light.
So as to obtain the maximum transmittance T, the χ should be π/4 or the Δnd/λ should be π/2 according to the equation 1. As the Δnd varies with the birefringence difference of the LC molecules from viewing directions, the λ value is varied in order to make Δnd/λ to be π/2. According to this condition, the color corresponding to the varied wavelength λ appears.
Accordingly, as the value of Δn relatively decreases at the viewing direction “a” toward the short axes of the LC molecules, the wavelength of the incident light for obtaining the maximum transmittance relatively decreases. Consequently a blue color having shorter wavelength than a white color is emerged.
On the other hand, as the value of An relatively increases at the viewing direction “b” toward the short axes of the LC molecules, the wavelength of incident light relatively increases. Consequently a yellow color having a longer wavelength than the white color is emerged. This causes deterioration to the resolution of IPS-LCDs.
To prevent the above disadvantages caused by color shift, a method for forming multi-domain within a unit pixel has been suggested. According to this method, one portion of an alignment layer is rubbed to a first direction, the other portion of the alignment layer is rubbed to second direction symmetrized the first direction. This method, however, is required additional masks compared to the conventional process of liquid crystal molecules alignment.
SUMMARY OF THE INVENTION
Accordingly, one object of the invention is to provide a LCD having wide viewing angle without color shift occurrence.
Another object of the present invention is to provide a method for fabricating such LCD mentioned above.
So as to accomplish the objects for the present invention, an LCD, comprising: a substrate; and a common electrode and a pixel electrode having same spiral shape formed on the substrate and being opposed each other, wherein an electric field formed between the common electrode and the pixel electrode is radial shape.
Further, the present invention provides an LCD having an electric field formed in parallel to surface of a substrate, comprising; a common electrode formed on the substrate with annular shape whose both edges are spaced each other; and pixel electrode formed on the substrate with annular shape whose both edges are spaced each other corresponding to the shape of the common electrode, wherein an electric field formed between the common electrode and the pixel electrode is radial shape and symmetric shape which is based on the kernel of respective electrode.
Also, to accomplish the above objects, the present invention provides a method for fabricating an LCD comprising the step of: forming a common electrode of spiral shape on a substrate; forming a pixel electrode of spiral shape to be opposed the common electrode; and coating an alignment layer on the surface of the substrate where the common electrode and the pixel electrode are disposed thereon, wherein a radial electric field is formed when a voltage is applied between the common electrode and the pixel electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a plane view showing a general IPS mode LCD.
FIG. 2 a is a plane view showing an electrode structure and an arrangement of liquid crystal molecules in LCD according to one embodiment of the present invention.
FIG. 2 b is a cross sectional view showing an electrode structure of LCD according to another embodiment of the present invention.
FIG. 3 is a plane view showing a liquid crystal molecules of negative dielectric anisotropy according to one embodiment of the present invention.
FIG. 4 is a plane view showing an electrode structure of an LCD according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the invention will be described in detail with reference to attached drawings.
FIG. 2 a and FIG. 2 b are drawings for showing liquid crystal molecule of positive dielectric anisotropy when it is vertically aligned. A common electrode 31 and pixel electrode 33 of squared spiral structure are opposed.
An electric field is formed across the common electrode 31 and the pixel electrode 33 when an external voltage is applied therebetween. At this time, the electric field has a radial shape since the common electrode 31 and the pixel electrode 33 are spiral shaped, then liquid crystal molecules 35 are aligned along the electric field of the radial shape. Accordingly, long axes and short axes of liquid crystal molecules are observed at the same time by the user in every azimuth angle of the screen. Therefore, the color shift is not occurred, since optical anisotropy is compensated.
FIG. 2 b is a cross-sectional view taken along the line a-b of FIG. 2 a and the electric field is indicated as arrows. As shown in the drawings, liquid crystal molecules 35 are symmetrical due to the electric field's being symmetrical. A common electrode 31 is formed on the substrate used as an upper or a lower plate for LCD(not shown) and an insulating layer 30 is deposited thereon. A pixel electrode 33 is formed on the insulating layer 30 not to overlap the common electrode 31 . The height difference referenced as “h” between the upper of pixel electrode and the lower of the common electrode is decided according to the thickness of insulating layer 30 . Although, FIG. 2 b shows the formation of pixel electrode 33 on the common electrode 31 by an insulating layer 30 , it is also available that the common electrode 31 and the pixel electrode 33 are formed on the same plane without the height difference “h”. Thereafter an alignment layer 36 is formed on the pixel electrode 33 and the insulating layer 30 . The alignment layer 36 is a homeotropic layer which needs no rubbing treatment.
Therefore according to this embodiment, liquid crystal molecules 35 are aligned radially in accordance with electrode 31 , 33 structure without some times rubbing process.
FIG. 3 shows liquid crystal molecules 45 of negative dielectric anisotropy used in the electrode structure of FIG. 2 a . The liquid crystal molecules 45 are aligned substantially in a same direction of the liquid crystal molecules 35 of FIG. 2 a except the liquid crystal molecules 45 aligned such that their short axes are perpendicular to the direction of electric field. Namely, the liquid crystal molecules 45 are aligned in symmetric configuration based on kernel of the pixel electrode 43 of spiral shape. Accordingly, the optical anisotropy which depends upon the viewing angles III and IV is equal to each other.
Although FIG. 2 a and FIG. 3 a show a square type spiral structure, the square can be replaced with a circle or a triangle.
FIG. 4 shows another embodiment of the invention, where a common electrode 51 and a pixel electrode 53 are shaped of annular whose both edges are separated each other such as the letter “C”. Those electrodes include withdrawal rods 51 - 1 and 53 - 1 which are withdrawn to the exterior of the band so as to be applied an external voltage. When an external voltage is applied to the common electrode 51 and the pixel electrode 53 through those rods 51 - 1 and 53 - 1 , a radial electric field is formed and then the liquid crystal molecules 55 are aligned along the direction of the electric field. The optical isotropy of liquid crystal molecule 55 equals each other. That means, the equal value of optical anisotropy in a viewing angle (V) and in a viewing angle (VI) prevents color shift and enhances the characteristics of viewing angle.
The electrode structure of FIG. 4 may be applied to the liquid crystal molecules of positive dielectric anisotropy as well as those of negative dielectric anisotropy. The electrode are also changeable as long as electric field is symmetrical from all directions based on central portion of the electrode.
Further, the pixel and the common electrodes can be disposed on the same plane and can be disposed by insulating layer upwardly with a predetermined height.
As described above, the liquid crystal molecules are symmetrical against all direction of views since the common electrode and the pixel electrode are arranged for forming the electric field to be radial shape. Therefore the liquid crystal molecules have the same optical isotropy which prevents color shift of the conventional IPS mode devices and improving the characteristics of viewing angle.
Also this invention can reduce manufacturing steps and masks since additional rubbing processes are not required.
While only preferred embodiments have been discussed and described, various changes and modifications can be made without departing from the spirit and scope of the invention as defined by the following claims.
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Disclosed is an LCD preventing color shift and simultaneously improving the characteristics of viewing angle. The LCD comprises a substrate and a common electrode and a pixel electrode having same spiral shape formed on the substrate and being opposed each other, wherein an electric field formed between the common electrode and the pixel electrode is radial shape.
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CROSS REFERENCE
[0001] This application is a continuation of PCT Application No. PCT/DE00/00428 filed 15 Feb. 2000 and which named the United States as a designated country.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of pre-packaged foods and, more particularly, concerns a method and an apparatus for separating discshaped bodies from a source body, wherein the environment of the face of the source body is illuminated.
BACKGROUND OF THE INVENTION
[0003] The respective face of the source body is optically detected with a detection device by means of the contrast between the environment of the face and the face. The slice thickness required for a predetermined slice weight is determined from the specific gravity of the source body and face. The separation of the disc-shaped body is controlled with the value determined in this way.
[0004] Many foods such as cheese, ham, sausage, etc. are provided for sale in the market prepacked in sliced form, a relatively large proportion being supplied as so-called equalized goods with a fixed weight. When cutting up the products, the fixed weight must be maintained as exactly as possible according to the tolerance standards of the prepacking regulations. Fluctuations in product cross-section within a product string, and also from one product string to the next, make it difficult, if not impossible, to meet these tolerance standards. Therefore it is advantageous to utilize methods for detecting the product cross-section at the right time, which allow adaptation of product advance the moment there is also a change in cross-section.
[0005] DE-C-28 20 583 C2 and EP 246 668 A2 describe a method in which the weight of the already cut-off slices is determined with scales, and advance is adjusted according to the measured total weight. This method is intricate and tedious because all scales need a certain time to reach their position of equilibrium. Rapid weighing is therefore thwarted by physical laws such as e.g. natural oscillation processes, poor filtering of interference, etc. and the unavoidable time lapse between weighing and cutting operations.
[0006] Also known, e.g. from U.S. Pat. No. 4,557,019, are methods which are based on scanning the surfaces of the products before the cutting operation. In this case the outer casing of the source body to be sliced is scanned, e.g. by a triangulation method, before the cutting operation and advance is later adapted during the cutting operation according to the previously calculated volume or the measured cross-sections. Due to the non-uniform shape of the products, however, the exact positioning is lost during transport to the cutting shaft. When the products are picked up by a gripper claw, particularly due to the associated buckling movement. Hence the actual cross-section is changed from the calculated one. Due to the limited number of cameras, shadow areas in which the surface is not correctly detected occur, depending on the actual shape of the products. Also, hollow layers and severe distortions as a rule lead to overestimates of volume. Although the illumination and soiling of the scanning device in this method are relatively unproblematic, the actual cross-sectional area is not determined with sufficient accuracy.
[0007] DE-A-38 08 790 A1 describes a method for detecting the cut surfaces during the cutting operation, in which the cut surface is illuminated with lamps and detected with a CCD camera, using the reflection behavior. Both the camera and the lamps are mounted in front of the cut surface. The method is limited in that if the height of fall cannot be made high enough for reasons of cutting technology, such as in the case of portions which, owing to their height increasing with cutting or special shingle techniques, come very close in front of the cutting surface. Also, problems arise with cutting devices which work with very high cutting outputs of up to 2,000 cuts per minute. At these high speeds the slice which has already been cut off is still falling while the picture is already being taken for the following slice which has not yet been cut. The camera and lighting angle must therefore inevitably be very flat, and it is almost impossible to accomplish illumination without throwing disturbing shadows or without uncontrolled back reflection. Furthermore, the camera and the lighting must be mounted in areas with extremely high contamination.
[0008] The above-mentioned drawbacks could be reduced with the cutting device described in DE-C-37 14 199 C2, by mounting the lighting elements directly behind the cutting plane adjacent to the cutting blade. Due to direct determination of the cut surface, the actual cross-sectional area can be detected very precisely. With the apparatus described, however, there arises problems with the picture quality due to reflection and shadow formation with different source bodies and due to shadow formation by additional elements of the cutting apparatus, e.g. holding arms.
[0009] U.S. Pat. No. 5,129,298 describes a cutting apparatus in which the contour of a source body is illuminated with dark field lighting. For this purpose, three lighting elements are mounted behind the source body for lighting a ground glass screen, in order to direct light rays obliquely from above in the longitudinal direction of the source body onto the upper cut edge and obliquely from the side onto the side edges. Due to reflection and shadow formation, however, the quality of illumination can be impaired. Also, hollow layers and indentations on the underside of the product cannot be detected.
[0010] From DE-C-42 06 196 C2 is known the use of an advance tunnel in conjunction with cutting machines. Traditional advance tunnels however are used only for safety reasons and for better guiding of the source body.
SUMMARY OF THE INVENTION
[0011] It is therefore an object of the invention to provide a method and an apparatus for separating disc-shaped bodies from a source body, in which one or more of the above-mentioned problems are avoided.
[0012] In accordance with the present invention there is provided a method for separating disc-shaped bodies from a source body wherein the environment of the face of the source body is illuminated, the respective face of the source body is optically detected with a detection device by means of the contrast between the environment of the face and the face, the slice thickness required for a predetermined slice weight is determined from the specific gravity of the source body and face, separation of the disc-shaped body is controlled with the value determined in this way, and the source body is guided in a tunnel and illuminated with a plurality of lamps which are mounted in planar fashion along the longitudinal direction of the source body in the tunnel.
[0013] With the method of the invention, the environment of the face of the source body should be illuminated, the respective face of the source body should be optically detected with a detection device by means of the contrast between the environment of the face and the face, the slice thickness required for a predetermined slice weight should be determined from the specific gravity of the source body and face, and separation of the disc-shaped body should be controlled with the value determined in this way.
[0014] A preferred apparatus comprises a separating device, an advance device for advancing the source body towards the separating device, an optical detection device for determining the face contour of the source body, and lamps for illuminating the environment of the cut surface, wherein the detection device determines the face by means of the contrast between the environment of the face and the source body. Furthermore, the source body is advanced as a function of the measured face.
[0015] The object is achieved by the fact that the source body is guided in a tunnel and the source body is illuminated with a plurality of lamps which are mounted in planar fashion along the longitudinal direction of the source body in the tunnel.
[0016] In accordance with the present invention there is provided a method for separating disc-shaped bodies from a source body having a face and a longitudinal direction, including the steps of: guiding the source body in a tunnel, mounting a plurality of lamps in a planar fashion along the longitudinal direction of the source body in the tunnel, illuminating the source body and the environment of the face of the source body with said plurality of lamps, optically detecting a respective face of the source body with a detection device by means of the contrast between the environment of the face and the face, determining the slice thickness required for a predetermined slice weight from the specific gravity of the source body and face, and controlling separation of the disc-shaped body from the source body utilizing the value determined in the preceding step.
[0017] Correspondingly, the apparatus includes a tunnel in which the source body is guided, the tunnel having an end adjacent a separating device, and means for mounting a plurality of lamps in the tunnel and in a planar fashion along the longitudinal direction of the source body. As a result, uniform, high-contrast illumination of the environment of the face is ensured. It was found that disturbing reflection and shadow formation can be substantially reduced by planar arrangement of lamps in a tunnel.
[0018] It was discovered that a tunnel is eminently suitable for improved illumination of the cut edges of the source body if a plurality of lighting elements are mounted in the tunnel.
[0019] Due to the fact that the lamps form a tunnel which begins a sufficient distance before the separating device or cutting plane and ends at the separating device, the source body is illuminated uniformly all round. Shadow formation can be reduced and the contrast increased by installing the lamps in a tunnel made of reflective material. The tunnel advantageously has up to four different regions which deliver different types of radiation. In a first region diffuse radiation occurs with an intensity that is reduced towards the cutting plane. The first region consists of the front surface of the tunnel adjacent to the cut surface, the central region of the tunnel cover, the front and central portions of the side walls, and the tunnel bottom.
[0020] Advantageously, the lamps may be individually adjusted by individually orienting the direction of radiation of the lamps, which can be accomplished, for example, by utilization of a motorized means. Advantageously the adjustment of the lamps is made with a corresponding control system comprising a memory for storing settings for the lamps. As a result, the settings for different ambient conditions can be adjusted once and called up again at any time without great effort, and the lamps can be adjusted with corresponding adaptation to the precise ambient conditions.
[0021] Because the lamps are controlled in pulsed fashion and the detection device is controlled in correspondingly triggered fashion, product-damaging heat generation is avoided and the camera focus and signal-to-noise ratio against ambient light are advantageously increased.
[0022] Advantageously, the lamps are readjusted during operation by the control system, which evaluates reflection signals and contrast information of the detection device and adjusts the lamps in such a way that the reflection is minimized and the contrast increased.
[0023] In a second region, radiation directed rearwards away from the cutting plane is delivered. This second region is composed of the front portion of the tunnel cover adjacent to the cutting plane, and serves in particular to illuminate additional elements such as product hold-down devices. In a third region, radiation directed obliquely forwards towards the cutting plane is delivered so that the cut edge is illuminated and the contrast increased. The third region is composed of the rear portion of the tunnel cover.
[0024] In a fourth region, radiation is directed straight onto the source body. This fourth region is composed at least of the central region of the exposed side wall. This region serves to illuminate the side surface of the source body.
[0025] It is particularly advantageous if at least the side wall, with which the source body is in contact, is slidable. Then the face can be oriented and detected optimally. By sliding the side walls, the lighting conditions can also be optimized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Reference is now made more particularly to the drawings which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the drawing figures. The embodiment of the invention is described in more detail below with the aid of the attached drawings in which:
[0027] [0027]FIG. 1 is a schematic view of an apparatus for separating disc-shaped bodies from a source body;
[0028] [0028]FIG. 2 is a front view of the apparatus;
[0029] [0029]FIG. 3 is a perspective view of a lighting frame for the apparatus; and
[0030] [0030]FIG. 4 is a longitudinal sectional view of the lighting frame.
DETAILED DESCRIPTION
[0031] [0031]FIG. 1 shows a schematic view of the apparatus for separating disc-shaped bodies 1 from a source body 2 , in which the source body 2 is mounted on an advance device 3 and delivered by the latter to a separating device 4 . The separating device 4 is, in the embodiment shown, an eccentrically rotating circular blade. The source body 2 is carried by a lighting frame 6 in the vicinity of the cut surface 5 . The upper side of the source body 2 is guided by a hold-down device 7 , which is inclined in the direction of transport T. The lighting frame 6 and the advance device 3 are inclined, so that the direction of transport T forms an angle of approximately 45° in relation to the horizontal. The disc-shaped bodies 1 then drop down by force of gravity and are transported away from the separating device 4 by a discharge belt 8 . The discharge belt 8 is a horizontal conveyor belt. The cut surface 5 of the source body 2 is detected by a camera 9 which is mounted on the right in front of the cut surface and at a relatively flat angle thereto. The
[0032] camera angle must be relatively flat, above all in case of very high cutting outputs, so that the uncut slices can already be photographed while the already cut-off slices are falling. Lighting elements 10 a, 10 b, 10 c are mounted in the lighting frame 6 and radiate downwards in the direction of the cut edge of the source body 2 .
[0033] [0033]FIG. 2 shows the front view of the apparatus. The source body 2 , e.g. sausage, ham, cheese, etc., is mounted in the lighting frame 6 and illuminated by the lighting elements 10 a, 10 b, 10 c which are installed in the lighting frame 6 .
[0034] The separating device 4 in this particular preferred embodiment is a circular blade which rotates on its own axis, with the shaft being mounted so as to rotate eccentrically. As a result, disc-shaped bodies 1 are separated cyclically one after the other from the source body 2 . The camera 9 is mounted at a flat angle on the right, in front of the cut surface 5 and the lighting frame 6 , and detects the whole opening of the lighting frame 6 . It can be seen that the lighting frame 6 forms a tunnel through which the source body 2 passes during the cutting operation. This tunnel begins, as can be seen in FIG. 1, at sufficient distance before the cutting plane and ends at the cutting plane. The camera 9 detects both the cut surface 5 and the front region of the lighting frame 6 directly. A detection device 11 connected to the camera 9 evaluates the contours between the cut surface 5 and the opening of the lighting frame 6 and determines the respective face of the source body 2 . From the previously established specific gravity of the source body 2 and the measured face, the slice thickness required for a predetermined slice weight is calculated. The advance device 3 is controlled by the detection device 11 in such a way that during subsequent cutting, the corresponding slice thickness is separated from the source body 2 .
[0035] The cut surface is detected as a dark field in the photography method described, i.e. the environment of the cut surface 5 is brightly lit and the cut surface 5 appears dark. For this purpose, as FIG. 3 reveals, the lighting frame 6 is divided into several regions I, II, III, IV wherein the adjustable lighting elements 10 are installed. The lighting elements 10 are adjusted differently in the individual regions. The portions of the lighting frame 6 detected directly by the camera form the background for the product contour and must give off a diffuse and weak light. Therefore the lamps 10 are oriented in such a way that region I exhibits a diffuse radiation, i.e. the radiation intensity is reduced towards the cutting plane, with the edge also giving off radiation. Region I consists of the front edge of the lighting frame 6 , a transverse strip in the middle of the cover 12 and the free side wall 13 of the lighting frame 6 , the front side edge and the side wall with which the source body 2 is in contact.
[0036] In region II a directed field is provided towards the rear for illuminating any component parts such as e.g. the hold-down device 7 , so that they do not cause any disturbing shadow on the illuminated surface of the source body 2 . The component parts can also be provided with additional lighting elements attached therein. The surface of the source body 2 is also illuminated by region II to avoid shadow formation, e.g. due to undulations of the product surface. Region II is located in the front region of the cover 12 of the lighting frame 6 .
[0037] In the rear region of the cover 12 , counter to the direction of transport T, is provided a region III which delivers directed radiation forwards in the direction of the edge of the source body 2 . The direction of radiation is oblique so that radiation through the source body 2 is as low as possible. Due to direct illumination of the edge, the contour of the source body 2 is emphasized.
[0038] Region IV is provided in the exposed at the center of the side wall 13 of the lighting frame 6 . Region IV delivers radiation directed straight onto the source body 2 . The other side wall with which the source body 2 is in contact may advantageously be slidable.
[0039] The lamps installed in regions I to IV may be manually or automatically adjustable, so that the lighting conditions can be adapted to the source bodies 2 and certain design conditions, such as for accommodating additional components and special hold-down devices 7 for the product. For this purpose a control system may be provided, not shown, comprising a memory in which settings of the lamps 10 , which are stipulated for different ambient conditions, are filed. The control system is further designed in such a way that the individual lamps 10 can be adapted not only for the main setting, but also for different variations during the cutting operation. For this purpose the control system is connected by an interface to the detection device and to actuators of the lamps 10 , wherein the detection device detects disturbing reflection and lack of contrast focus and delivers corresponding information to the control system for readjustment of the lamps 10 .
[0040] The detection device 11 should be able to make a correction of the surface or its edge, depending on the pixel position of the detected image, thus equalizing the distortions by the angle of view and the distortions of the lens of the camera 9 . Then correct determination of the cross-sectional area is possible. This rectification should preferably be carried out by corresponding hardware, so that with each cut, an image evaluation and adaptation of advance can take place immediately.
[0041] [0041]FIG. 4 shows the lighting frame 6 in longitudinal section. From the path of the rays, which differs in the different regions I, II and III, it can be seen that the source body 2 is illuminated in planar fashion along its longitudinal direction, with different degrees of brightness and directions of radiation being provided. A first section A extends from the cut surface 5 , in the longitudinal direction of the source body 2 , counter to the direction of transport T. This section A has a low radiation intensity which is caused in particular by the fact that the light in region II is directed rearwards and the lamps 10 in section A give off diffuse radiation of low intensity. The section B located behind section A, seen counter to the direction of transport T, exhibits a high radiation intensity. For this purpose the lamps 10 in region I are controlled in such a way that they give off very bright light. A third section C in the region of the edge of the cut surface 5 is also irradiated with a high intensity by controlling the lamps 10 in region III accordingly.
[0042] It is particularly advantageous if the individual lamps 10 are controlled in pulsed fashion so that negligible generation of heat occurs. The camera 9 and the detection device 11 are, for this purpose, significantly operated in correspondingly triggered or shuttered fashion, so that a good camera focus and a high signal-tonoise ratio against ambient light are guaranteed. Furthermore a suitable additional lighting means can be arranged in front of the face 5 , with the result that the dark field can be evaluated with differentiation, e.g. to distinguish between fat and lean meat, or to detect holes existing in cheese and to factor the same in the weight calculation.
[0043] The radiation intensity of the lamps 10 can also be controlled by a lighttransmitting element provided on the inner surface of the lighting frame, in which the light transmitting capacity is controllable. The element can be constructed after the fashion of an LCD display with a control matrix, with individual regions of the element being controllable differently. Or a plurality of elements which are each independently adjusted with a certain light transmitting capacity for the whole element may be provided.
[0044] Other objects, features and advantages will be apparent to those skilled in the art. While preferred embodiments of the present invention have been illustrated and described, this has been by way of illustration and the invention should not be limited except as required by the scope of the appended claims.
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A device for separating disc-shaped bodies from an original body includes a separating device, a feeding device, an optical recognition device for determining the front face contour of the original body and lamps for illuminating the surroundings of the cutting surface. The recognition device detects the front face using the contrast between the surroundings of the front face and the original body in relation to the determined front face. The lamps are mounted in a tunnel and arranged in a planar manner along the longitudinal direction of the original body. The method includes the steps of guiding the source body in a tunnel, mounting a plurality of lamps in a planar fashion along the longitudinal direction of the source body in the tunnel, and illuminating the source body and the environment of the face of the source body with said plurality of lamps.
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PRIORITY INFORMATION
[0001] This application claims priority under 35 U.S.C. 119(e) from U.S. Provisional Patent Application No. 61/229,152, filed Jul. 28, 2009, for a “Long Lasting, Energy and Thermally Efficient, Customizable Solid-State Lighting Fixtures,” by Desphande, is hereby incorporated by reference in its entirety for its teachings.
FIELD OF THE INVENTION
[0002] This invention relates to environment friendly general illumination apparatuses. The invention particularly relates to Eco-friendly, long lasting, energy efficient, solid-state lighting apparatuses.
BACKGROUND OF INVENTION
[0003] Global concerns have been raised regarding the amount of power consumed by currently used incandescent lamps and high pressure sodium vapor lamps, and by extension, the amount of atmospheric CO2 released due to such power consumption. Also incandescent lamps have shorter life span and use hazardous materials, thus attracting high maintenance costs and are non-friendly to ecosystem and unsustainable by nature. Because of this, solid-state based illumination has received attention as an optimum energy-conserving, eco-friendly light source, of future.
[0004] The proven unsustainability of conventional incandescent lighting sources has led to the change in energy policies across the world. To combat climate change the European Union has agreed to phase out conventional light sources that are energy inefficient. According to an EU Directive, from 1 Sep., 2009 manufacturers and importers may no longer sell incandescent lamps with an output of 80 W (950 lm) or more or which are frosted and not in Energy Class A. Clear lamps with more than 950 lm must achieve at least Energy Class C, and ones with less than 950 lm at least Energy Class E. Lamps in Energy Classes F and G will be banned from 1 Sep., 2009. For the lighting industry there are already phase-out scenarios for household lighting and lighting in the tertiary sector (street, office and industry lighting) and these scenarios are currently being discussed. The less efficient light sources will start being phased out as early as this year.
[0005] Cuba exchanged all incandescent light bulbs for CFLs, and banned the sale and import of them in 2005. Brazil and Venezuela phased out incandescent light bulbs in 2005. In Argentina, selling and importing incandescent light bulbs will be forbidden starting 31 Dec. 2010. In Canada the provincial government has announced intention to ban the sale of incandescent light bulbs by 2012. In USA, federal Clean Energy legislation effectively banned (by January 2014) incandescent bulbs that produce 310-2600 lumens of light. Bulbs outside this range (roughly, light bulbs currently less than 40 Watts or more than 150 Watts) are exempt from the ban. Also exempt are several classes of specialty lights, including appliance lamps, “rough service” bulbs, 3-way, colored lamps, and plant lights.
[0006] Philippines, In February 2008, called for a ban of incandescent light bulbs by 2010 in favor of more energy-efficient fluorescent globes to help cut greenhouse gas emissions and household costs during her closing remarks at the Philippine Energy Summit.
[0007] Switzerland banned the sale of all light bulbs of the Energy Efficiency Class F and G, which affects a few types of incandescent light bulbs. Most normal light bulbs are of Energy Efficiency Class E, and the Swiss regulation has exceptions for various kinds of special-purpose and decorative bulbs.
[0008] The Irish government was the first European Union (EU) member state to ban the sale of incandescent light bulbs. It was later announced that the member states of the EU agreed to a phasing out of incandescent light bulbs by 2012. United Kingdom has enlisted the help of retailers with a voluntary, staged phase out.
[0009] In February 2007 the Australian Federal Government announced the introduction of minimum energy performance standards (MEPS) for lighting products.
[0010] Though the very unsustainable nature of the incandescent lamps is now well understood by the masses but the alternatives that we currently have e.g. CFLs (compact fluorescent lamps) are also not the best choice.
[0011] CFLs, like all fluorescent lamps, contain small amounts of mercury as vapor inside the glass tubing, averaging 4.0 mg per bulb. A broken compact fluorescent lamp will release its mercury content. Safe cleanup of broken compact fluorescent lamps differs from cleanup of conventional broken glass or incandescent bulbs. Because household users in most regions have the option of disposing of these products in the same way they dispose of other solid waste most CFLs are going to municipal solid waste instead of being properly recycled.
[0012] Moreover the cost of CFLs is higher than incandescent light bulbs. Typically this extra cost may be repaid in the long-term as CFLs use less energy and have longer operating lives than incandescent bulbs. However, there are some areas where the extra cost of a CFL may never be repaid, typically where bulbs are used relatively infrequently such as in little-used closets and attics. It is also currently not possible to obtain CFL versions of the range of colours and effects. In the past decade, hundreds of Chinese factory workers who manufacture CFLs for export to first world countries were being poisoned and hospitalized because of being exposed to mercury (The Sunday Times, May 3, 2009).
[0013] To overcome the economic, environmental and health issues associated with the conventional incandescent lights and CFLs (Compact fluorescent lamps), the alternative solution for illumination purposes, use of environment friendly general illumination fixtures based on smart use of solid-state lighting devices.
[0014] Solid-state lighting has the potential to revolutionize the lighting industry. Light-emitting diodes (LEDs)—commonly used in signs, signals and displays—are rapidly evolving to provide light sources for general illumination. This technology holds promise for lower energy consumption and reduced maintenance.
Characteristic Benefits of Solid State Lighting Include:
[0000]
1. Long life—LEDs can provide 50,000 hours or more of life, in comparison, an incandescent light bulb lasts approximately 1,000 hours.
2. Energy savings—the best commercial white LED lighting systems provide more than twice the luminous efficacy (lumens per watt) of incandescent lighting. Colored LEDs are especially advantageous for colored lighting applications because filters are not needed.
3. Better quality light output—LEDs have minimum ultraviolet and infrared radiation.
4. Intrinsically safe—LED systems are low voltage and are generally cool to the touch.
5. Smaller flexible light fixtures—The small size of LEDs makes them useful for lighting tight spaces.
6. Durable—LEDs have no filament to break and can withstand vibrations. Last longer than any conventional light source
7. Reduced maintenance costs and energy costs
8. Focused Lighting—Directed light for increased system efficiency, directional resulting in highly controllable optical systems.
9. No moving parts, nothing to break, rupture, shatter, leak or contaminate the environment.
10. Green Technology—They emits no ultraviolet rays, infrared heat, and contains no mercury or lead.
11. Their long life and small size means far less waste.
12. Low Voltage current driven solid-state device operating at voltages as low as 3 VDC.
13. Cold Start Capable no ignition problems in cold environments—even down to −40° C.
[0028] The term “solid state” refers to the fact that light in an LED is emitted from a solid object—a block of semiconductor—rather than from a vacuum or gas tube, as is the case in traditional incandescent light bulbs and fluorescent lamps. Compared to incandescent lighting, however, SSL creates visible light with reduced heat generation or parasitic energy dissipation, similar to that of fluorescent lighting. In addition, its solid-state nature provides for greater resistance to shock, vibration, and wear, thereby increasing its lifespan significantly.
[0029] SSL devices are based on the semiconductor diode, When the diode is forward biased (switched on), electrons are able to recombine with holes and energy is released in the form of light. This effect is called electroluminescence and the color of the light is determined by the energy gap of the semiconductor. One of the major challenges in using SSL is the management of heat that dissipates from the junction diode. The efficiency of the LED depends largely on its heat-dissipation. The ambient temperature of the surrounding environment has an effect on the performance of the LED by leading to its self-heating. Overdriving it in a high ambient temperature may have an adverse effect on its light-emitting capacity. As the semiconductor die in the LED heats up, the light output of the LED decreases thus reducing its efficiency. Thus over-heating of the LED may lead to a device failure.
[0030] The possible approach to compensate for LED self-heating effect is to design the body of fixture panel of the LED lighting device in a way that it dissipates as much heat as possible. The maximum heat dissipation can be achieved by virtue of the design and material of the lighting fixture panel on which the solid-state lighting devices are mounted upon.
[0031] Some of the inventions which illustrate various designs of the LED based illumination devices are:
[0032] US20080089069 filed by Medendorp teaches a solid state lighting subassembly or fixture which includes an anisotropic heat spreading material. In this invention the said anisotropic heat spreader in thermal contact with the solid state light source and the thermally conductive component of the lighting fixture so as to spread heat from the solid state light source in a preferential direction from the solid state light source to said thermally conductive component.
[0033] US20080062689 filed by Villard teaches an LED lighting fixture which includes a support plate having a first surface and a second surface, a plurality of panels connected to the first surface, in which each panel has an array of LEDs mounted to a planar surface thereof, and a power supply provided on the second surface of the support plate for driving the LED arrays.
[0034] U.S. Pat. No. 7,488,093 to Huang, et al. teaches an LED lamp which includes a frame, LED module, a heat sink and a cover. The LED module has a plurality of LEDs. The heat sink is mounted on the frame. The heat sink is attached to a side of the LED module for dissipating heat generated by the LEDs of the LED module. A heat pipe interconnects the heat sink and the cover. The cover is secured so as to shield a top portion of the heat sink and space from the top portion of the heat sink. In addition to the heat sink which can dissipate the heat generated by the LEDs, the heat is also dissipated by the cover via the heat pipe.
[0035] US20080231201 filed by Higley et al teaches a (LED) lighting fixture which comprising: a main housing having a bottom surface supporting an array of LEDs, a top surface and sides, at least one driver provided in a side housing attached to a side of the main housing to drive the LED array, the thickness of the driver housing equal to or greater than the thickness of the main housing, and plurality of heat spreading fins arranged on the top surface of the main housing.
[0036] The inventions mentioned above do not address the needs of customizability, fast production, maintenance, precision dimensional accuracy and affordability of the SSL fixture based lighting solution.
[0037] Thus, in the light of the above mentioned background of the art, it is evident that, there is a need for a solid-state lighting solution which:
provides efficient heat dissipation; can be thermally efficient; provides efficient power utilization; can be environmental friendly; can be custom manufactured with high degree of speed and flexibility; can be easily serviceable; and can be easily installed. is affordable and low cost can combat global warming
SUMMARY OF THE INVENTION
[0047] The principle object of the present invention is to provide lighting solutions which are power efficient, environment friendly and long lasting and can be custom manufactured with high degree of speed, accuracy and flexibility.
[0048] Another significant object of the invention is to provide the solid state lighting apparatuses which can achieve a power factor ratio >0.98 by utilizing a power supply unit to reduce the reactive power.
[0049] It is another object of the present invention to provide the solid state lighting apparatuses which can achieve more than 90% of the light in required area by mounting a lens on solid state lighting sources thereby preventing the scattering of the light in unnecessary areas. The amount of light which goes in undesired planes is minimal 0.01-20%.
[0050] It is another object of the present invention is to provide high degree of flexibility to adapt the design of the fixture according to utility by using CAD and CNC process.
[0051] Another object of the invention is to reduce the waste of raw material thereby utilizing maximum percentage raw material for produce solid state lighting fixtures using CAD and CNC process.
[0052] Still another object of the invention is to provide light weight lighting apparatuses which can be produced and transported economically and have a higher economical scrap value even on completion of life term of the lighting apparatuses.
[0053] Yet another object of the invention is to provide the solid state lighting apparatuses which are easily serviceable, wherein the power supply units are an independent component and can be replaced in case of failures.
[0054] Another object of the invention is to design the fixtures in a manner such that the entire bodies of the fixtures are acting as efficient heat sink, wherein the heat dissipation is maximum in x, y coordinates in lateral direction of the fixtures due to thickness (z-axis) of the fixtures in the range from 0.5 to 6 mm and the fixture is made of at least one thermally conductive sheet metal and the sheet metal material is selected from the set of aluminum, iron, steel, copper or combinations or alloys thereof.
[0055] Yet another object of the invention is to achieve larger surface area for dissipating heat in the solid state lighting apparatuses by exposing maximum surface area on both bottom and top sides of the fixture in x and y axis.
[0056] Yet another object of the invention is to achieve optimum and homogenous luminous photometry by inclining one or more plane of the fixture including the base plane of the fixture into desired angle, the said angle can be in the range from 0-360 degree.
[0057] Further object of the invention is to provide a photo sensor means which is coupled with AC or DC input power, the said photo sensor means configured to selectively control the power input to the solid state lighting apparatus, wherein the photo sensor means can be Day light sensor or High Accuracy Ambient Light Sensor.
[0058] A still another object of the invention is to provide retrofitting lighting apparatuses which can be replaced without making considerable changes in existing infrastructure. Their design aspects do not require special enclosures of physical infrastructure to be made. Taking an example of a street light, by virtue of the custom built retrofit design, the poles need not to be changed rather the retrofit design of proposed lighting apparatuses can replace the existing hoods.
[0059] Still another object of the invention is to provide lighting apparatuses which can be withstand extreme conditions of weather including rains, dust storms, snow fall, wind and heat.
[0060] A further object of the invention is to provide water proofing up to desired levels (ingress protection) to the lighting apparatuses which are achieved by virtue of its design.
[0061] Yet another object of the invention is to provide lighting apparatuses which are having anodized bodies to achieve corrosion and scratch free surfaces for smooth heat flow.
[0062] Another object of the invention is to protect top side heat dissipating areas of the fixture including primary heat sink and secondary heat sink and heat dissipating panels from any sort of bird droppings and/or any other droppings.
[0063] Before the present apparatuses, and methods enablement are described, it is to be understood that this invention in not limited to the particular apparatuses, and methodologies described, as there can be multiple possible embodiments of the present invention and which are not expressly illustrated in the present disclosure or drawings. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.
[0064] The present invention provides lighting solutions which are power efficient, environmental friendly and long lasting and can be custom manufactured with high degree of speed, accuracy and flexibility. The lighting fixtures of the current invention are also easily serviceable.
[0065] According to one embodiment of the invention, long lasting, energy efficient, solid-state lighting apparatus having customizable design, wherein the said apparatus comprises a fixture having at least one mounting surface, optionally one or more slit, hole or fin, selectively punched on the mounting surface of the fixture for achieving additional heat dissipation and minimizing the resistance to wind. One or more plane of the fixture including the base plane of the fixture can adjustably be inclined to achieve desired photometry.
[0066] The above said fixture is made of at least one thermally conductive sheet metal, wherein the thermally conductive sheet metal is selected from the set of aluminum, iron, steel, copper or combinations or alloys thereof. The fixture is manufactured by computerized numerically controlled (CNC) process; the said fixture is characterized in having;
i. the entire body of the fixture acting as primary heat sink, wherein the fixture is designed in a manner, such that the heat dissipation is maximum in x, y coordinates laterally of the fixture due to optimized thickness (z-axis) of the fixture maintained in the range from 0.5 to 6 mm; ii. anodization for preventing corrosion and scratches thereby increasing thermal conductivity; iii. a power supply unit enclosed in a housing of fixture, wherein the power supply unit provides required DC or AC voltage to one or more solid state light emitting sources, wherein the required DC or AC voltage can be generated from AC or DC input power; iv. optimized design enabling maximum light spread in the required area;
[0071] At least one metal core Printed Circuit Board (MCPCB) mounted on the mounting surface and at least one solid state light emitting source is mounted on the said MCPCB. Optionally one or more lens mounted on one or more solid state light emitting sources for preventing the scattering of the light in unnecessary areas and thereby directing the light into desired areas. Optionally one or more protective transparent or translucent sheet covering one or more solid state light emitting sources for preventing the insects entering the lighting apparatus wherein the material of the protective transparent or translucent sheet can be selected from glass, plastic, and/or clear polycarbonate. Optionally a coated/plated layer of copper sandwiched between the primary heat sink and MCPCB, wherein such layer may further have a means for preventing corrosion. The said solid state light emitting source can be selected from the group of low power or high power LEDs including LED, OLED, PLED. One or more layers of thermal interface material (e.g. silicon rubber) placed between primary heat sink and MCPCB as well as primary heat sink and secondary heat sink and two or more secondary heat sinks.
[0072] The lighting apparatus further comprising one or more heat dissipating panels acting as secondary heat sink mounted on the front or reverse side of fixture, optionally having one or more slit, hole or fin, selectively punched on the secondary heat sink for achieving additional heat dissipation and minimizing the resistance to wind and wherein such secondary heat sink is made of at least one thermally conductive material selected from the set of aluminum, iron, steel, copper or combinations or alloys thereof. One or more layers of thermal interface material (e.g. silicon rubber) placed between primary heat sink and MCPCB as well as primary heat sink and secondary heat sink and two or more secondary heat sinks.
[0073] Further the lighting apparatus is installed with a photo sensor means and/or motion sensor means when used for public lighting purposes, a photo sensor means and/or motion sensor means coupled with AC or DC input power or power supply unit, the said photo sensor means and/or motion sensor means are configured to selectively control the power input to the solid state lighting apparatus, wherein the photo sensor means can be Day light sensor or High Accuracy Ambient Light Sensor. Further the lighting apparatus enabled to achieve ingress protection standards wherein the standards can be IP65, IP66, and IP67 or any other Ingress Protection standards issued by the European Committee for Electro Technical Standardization.
[0074] According to another embodiment of the invention, long lasting, energy efficient, solid-state lighting apparatus having customizable design, wherein the said apparatus comprises a fixture having at least one mounting surface, optionally one or more slit, hole or fin, selectively punched on the mounting surface of the fixture for achieving additional heat dissipation and minimizing the resistance to wind. The above said fixture is made of at least one thermally conductive sheet metal, wherein the thermally conductive sheet metal is selected from the set of aluminum, iron, steel, copper or combinations or alloys thereof. The fixture is manufactured by computerized numerically controlled (CNC) process; the said fixture is characterized in having;
i. the entire body of the fixture acting as first primary heat sink, wherein the fixture is designed in a manner, such that the heat dissipation is maximum in x, y coordinates laterally of the fixture due to optimized thickness (z-axis) of the fixture maintained in the range from 0.5 to 6 mm; ii. anodization for preventing corrosion and scratches thereby increasing thermal conductivity; iii. a power supply unit enclosed in a housing of fixture, wherein the power supply unit provides required DC or AC voltage to one or more solid state light emitting sources; iv. optimized design enabling maximum light spread in the required area;
[0079] At least one metal core Printed Circuit Board (MCPCB) mounted on the mounting surface and at least one solid state light emitting source is mounted on the said MCPCB and the said solid state light emitting source can be selected from the group of low power or high power LEDs including LED, OLED, PLED, second primary heat sink with heat insulating sheet and/or buffer spacing is placed on the rear side of the fixture and at least one solid state light emitting source from MCPCB which is mounted on first primary heat sink is connected thermally to such heat sink by way of metallic thermal interface and isolators through cut-out opening provided in the first primary heat sink.
[0080] The fixtures of the above said apparatuses are made by using CNC Process comprising the steps of:
a. Selecting a sheet metal, wherein the said sheet metal can be selected from set of aluminum, iron, steel, copper or combinations or alloys thereof; b. Inserting the sheet metal in to a CNC machine, wherein programmed instructions cause the processor in the CNC machine to enable punching of the sheet metal in accordance to the fed design of one or more fixture and c. Optionally bending the punched fixture at one or more places using the CNC machine.
[0084] A method for manufacturing of long lasting, energy efficient, solid-state lighting apparatus having customizable design comprising steps of:
a. Feeding at least one design of the fixture in to a CNC machine along with a sheet metal; b. Punching the sheet metal as per the design to achieve one or more fixtures; c. Optionally Bending the punched fixtures at one or more places; d. Anodizing the fixture to achieve corrosion and scratch free surface; e. Fixing of nutsurts/inserts/rivet nuts (hardware) pneumatically in to the fixture; f. Mounting on the fixture at least one metal core Printed Circuit Board (MCPCB) on which at least one solid state light emitting source is already mounted; and g. Mounting one or more power supply unit in a housing of the fixture.
[0092] The method further comprises placing second primary heat sink with heat insulating sheet and/or buffer spacing on the rear side of the fixture and connecting thermally at least one solid state light emitting source from MCPCB which is mounted on first primary heat sink to second primary heat sink by way of metallic thermal interface and isolators through cut-out opening provided in the first primary heat sink; placing coated layer of copper between the primary heat sink and MCPCB, wherein such coated layer may further have a means for preventing corrosion; and mounting one or more heat dissipating panels (secondary heat sinks) on the front or reverse side of fixture.
[0093] Further the method having optionally mounting a photo sensor means and/or a motion sensor in front and/or rear side of the fixture; optionally mounting one or more lens on one or more solid state light emitting sources; optionally covering one or more protective transparent or translucent sheet on one or more solid state light emitting sources; and placing one layer of thermal interface material between primary heat sink and MCPCB as well as primary heat sink and secondary heat sink and between two or more secondary heat sinks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0094] The foregoing summary, as well as the following detailed description of preferred embodiments, are better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings example constructions of the invention; however, the invention is not limited to the specific apparatuses and methods disclosed. In the drawings:
[0095] FIG. 1 illustrates a front view of solid state lighting apparatus which is used for street light application according to one exemplary embodiment of the invention.
[0096] FIG. 2 illustrates a back view of solid state lighting apparatus which is used for street light application according to one exemplary embodiment of the invention.
[0097] FIG. 3 illustrates an isometric front view of solid state lighting apparatus which is used for street light application according to one exemplary embodiment of the invention.
[0098] FIG. 4 illustrates a top view of solid state lighting apparatus which is used for Bay Light application according to another exemplary embodiment of the invention.
[0099] FIG. 5 illustrates a bottom view of solid state lighting apparatus which is used for Bay Light application according to another exemplary embodiment of the invention.
[0100] FIG. 6 illustrates a top view of solid state lighting apparatus which is used for Bay Light application according to another exemplary embodiment of the invention.
[0101] FIG. 7 illustrates an isometric front view of solid state lighting apparatus which is used for flood light application according to one exemplary embodiment of the invention.
[0102] FIG. 8 illustrates an isometric front view of solid state lighting apparatus which is used for High Mast application according to another exemplary embodiment of the invention.
[0103] FIG. 9 illustrates an isometric back view of solid state lighting apparatus which is used for High Mast application according to another exemplary embodiment of the invention.
[0104] FIG. 10 illustrates an isometric front view of solid state lighting apparatus which is used for Indoor down light application according to one exemplary embodiment of the invention.
[0105] FIG. 11 illustrates an isometric back view of solid state lighting apparatus which is used for Indoor down light application according to one exemplary embodiment of the invention.
[0106] FIG. 12 shows cross sectional view of solid state lighting apparatuses with first level of heat management system according to one embodiment of the invention.
[0107] FIG. 13 shows cross sectional view of solid state lighting apparatuses with enhanced second level of heat management system according to another embodiment of the invention.
[0108] FIG. 14 shows cross sectional view of solid state lighting apparatuses with enhanced third level of heat management system according to one embodiment of the invention.
[0109] FIG. 15 shows cross sectional view of solid state lighting apparatuses with enhanced fourth level of heat management system according to another embodiment of the invention.
[0110] FIG. 16 shows optical and electrical experimental data as per IES LM 79-08 of the solid state lighting fixtures.
[0111] FIG. 17 shows flux distribution diagram of the solid state lighting apparatus based on the IESNA luminaire classification system.
DETAILED DESCRIPTION
[0112] Some embodiments of this invention, illustrating all its features, will now be discussed in detail.
[0113] The words “comprising,” “having,” “containing,” and “including,” and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.
[0114] It must also be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Although any apparatuses or methods or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred apparatuses and methods are now described.
[0115] Heat Sink: A component designed to lower the temperature of the electronic/semiconductor device to which it is connected by dissipating excess heat generated at its junction point. It is often finned, and made from metals which dissipate heat faster such as aluminum, copper etc. In the current case the whole body of the fixture acts as a heat sink and heat sink is used in the form of sheet metal.
[0116] Fixtures: unless otherwise defined in this invention “fixtures” refer to a system which comprises one or more Solid State Lighting devices mounted upon the metallic frame along with the other electrical/electronic and non-electrical/electronic components.
[0117] Solid-state light emitting source (SSL): refers to a type of low power or high power lighting devices that uses light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination.
[0118] The present invention provides lighting solutions which are power efficient, environmental friendly and long lasting and can be custom manufactured with high degree of speed, accuracy and flexibility. The lighting fixtures of the current invention are also easily serviceable.
[0119] A long lasting, energy efficient, solid-state lighting apparatus having customizable design, wherein the said apparatus comprises:
a) a fixture having at least one mounting surface, wherein the said fixture is made of at least one thermally conductive sheet metal and is manufactured by computerized numerically controlled (CNC) process, the said fixture is characterized in having;
i. the entire body of the fixture acting as primary heat sink, wherein the fixture is designed in a manner, such that the heat dissipation is maximum in x, y coordinates laterally of the fixture due to optimized thickness (z-axis) of the fixture maintained in the range from 0.5 to 6 mm; ii. anodization for preventing corrosion and scratches thereby increasing thermal conductivity; iii. a power supply unit enclosed in a housing of fixture, wherein the power supply unit provides required DC or AC voltage to one or more solid state light emitting sources; iv. optimized design enabling maximum light spread in the required area;
b) at least one metal core Printed Circuit Board (MCPCB) mounted on the mounting surface; and c) at least one solid state light emitting source mounted on the said MCPCB.
[0127] FIGS. 1 , 2 , and 3 illustrates a front, back and isometric front views of solid state lighting apparatus which is used for street light application according to one exemplary embodiment of the invention. A long lasting, energy efficient, solid-state lighting apparatus having customizable design, wherein the said apparatus comprises a fixture 102 having two mounting surfaces 104 , namely a left side mounting surface 104 a and a right side mounting surface 104 b , optionally one or more slit 108 , hole 110 or fin 112 , selectively punched on the mounting surface 104 of the fixture 102 for achieving additional heat dissipation and minimizing the resistance to wind. The said slit 108 , hole 110 or fin 112 can be any shape based on the requirements. One or more plane of the fixture 102 including the base plane of the fixture can adjustably be inclined into desired angle to achieve desired photometry; the said angle can be in the range from 0-360 degree.
[0128] The above said fixture 102 is made of at least one thermally conductive sheet metal, wherein the thermally conductive sheet metal is selected from the set of aluminum, iron, steel, copper, or combinations or alloys thereof. The said fixture 102 is manufactured by computerized numerically controlled (CNC) process; the said fixture is characterized in having;
i. the entire body of the fixture 102 acting as primary heat sink, wherein the fixture is designed in a manner, such that the heat dissipation is maximum in x, y coordinates laterally of the fixture due to thickness (z-axis) of the fixture 102 in the range from 0.5 to 6 mm; ii. anodization for preventing corrosion and scratches thereby increasing thermal conductivity; iii. a power supply unit 116 (not shown in the figures) enclosed in a housing 114 of fixture 102 wherein the power supply unit 116 provides required DC or AC voltage to one or more solid state light emitting sources; iv. optimized design enabling maximum light spread in the required area;
[0133] The base plane of the fixture 102 supports each element of the solid state lighting apparatus 100 . A metal core Printed Circuit Board (MCPCB) 118 mounted on the central mounting surface of the fixture 102 , optionally a coated layer of copper 168 (not shown in the figures) sandwiched between the primary heat sink 102 and MCPCB 118 and Two high intensity solid state light emitting sources 120 are mounted on the MCPCB 118 and edges thereof secured thereon the central mounting surface 104 and the said solid state light emitting sources 120 can be selected from the group of low power or high power LEDs including LED, OLED, and PLED, wherein protective transparent sheet 124 or lens 122 (not shown in figures) are mounted on the high intensity solid state light emitting sources 120 for preventing the scattering of the light in unnecessary areas and thereby directing the light in to desired area.
[0134] Two MCPCBs 118 mounted on the left and right side of the mounting surfaces 104 a and 104 b and an array of solid state light emitting source 120 mounted on the MCPCBs 118 . Two protective transparent sheets 124 are employed for covering the solid state light emitting sources 120 for preventing the insects entering the lighting apparatus, According to one embodiment of the invention, the material of the protective transparent sheet 124 can be selected from glass and/or clear polycarbonate.
[0135] The above said MCPCB 118 comprises of three layers namely bottom layer, middle (insulation) layer and top layer (not shown in the figures). The bottom layer is made up of at least one thermally conductive material selected from the set of aluminum, iron, steel, copper or combinations or alloys thereof. The bottom layer is connected with the mounting surface 104 of the fixture 102 with a thermal interface layer. The middle layer is made of electrically insulating material and used to conduct the heat from the top layer of the MCPCB 118 and not allowing conduction of electricity from the top layer to bottom layer. The top layer is made up of copper or any other metal having better heat and electrical conductivity than copper e.g. Gold plated copper. At least one solid state light emitting source 120 mounted thereon the top layer of the MCPCB 118 .
[0136] Two heat dissipating panels 126 (not shown in the figures) acting as secondary heat sink are mounted (left and right side, each one respectively) thereon the reverse side of fixture 102 wherein the secondary heat sink 126 is made of at least one thermally conductive material selected from the set of aluminum, iron, steel, copper or combinations or alloys thereof. Optionally one or more slit 108 , hole 110 or fin 112 , selectively punched on the mounting surface 104 of the fixture 102 for achieving additional heat dissipation and minimizing the resistance to wind. The said slit 108 , hole 110 or fin 112 can be any shape based on the requirements.
[0137] The secondary heat sink 126 on the top-side heat dissipating area is covered by means of a metal covering 128 affixed thereon the fixture 102 protecting the elements underneath and wherein the metal covering 128 prevents coating of upper heat dissipating area from bird droppings and any other droppings, these droppings reduces heat dissipation ability of the top side heat dissipating area of the fixture 102 .
[0138] A housing 114 secured thereon the distal ends of the fixture 102 . A power supply units 116 are mounted inside said housing 114 , the solid state lighting apparatus 100 is easily serviceable, wherein the power supply units are independent components and can be replaced in case of failures. The power supply units 116 electrically connected to each of solid state light emitting sources 120 by means of connecting wires extending from the power supply units 116 to the solid state light emitting source 120 . The said power supply unit 116 achieves a power factor >0.98 thereby reducing the reactive power. The required DC or AC voltage can be generated from AC or DC input power. The AC/DC input power supply can be converted into required DC power supply for operation of the solid state light emitting sources 120 by using AC to DC converter, or DC to DC converter as per requirement.
[0139] Further solid state lighting apparatus 100 is installed with a photo sensor means 134 and/or motion sensor means 172 (not shown in the figures) when used for public lighting purposes, a photo sensor means 134 and/or motion sensor means 172 coupled with AC or DC input power or power supply unit, the said photo sensor means 134 and motion sensor means 172 are configured to selectively control the power input to the solid state lighting apparatus 100 , wherein the photo sensor means 134 can be Day light sensor or High Accuracy Ambient Light Sensor.
[0140] The motion sensor means 172 can be worked in two ways for saving the energy, one way operation based on sensing the motion wherein motion sensor means 172 is configured to control the power input to switch ON the solid state lighting apparatus 100 . If there is no motion is sensed by the motion sensor means 172 thereby configured to control the power input to switch OFF the solid state lighting apparatus 100 . Second way of operation is based on sensing the motion, wherein upon detection of motion the motion sensor means 172 is configured to allow 100% power input to the solid state light emitting sources 120 to improve light intensity by 100%. If there is no motion sensed by the motion sensor means 172 the power input to the solid state light emitting sources 120 is reduced to reduce the light intensity up to 90%.
[0141] According to one embodiment of the invention, solid state lighting apparatus 100 is installed with a timer 174 (not shown in the figures) coupled with AC or DC input power, the said timer means configured to selectively control the power input to the solid state lighting apparatus. The timer 174 can be worked in n number of ways to selectively control the power supply of the solid state lighting apparatus 100 for switching ON and OFF and controlling light intensity by controlling the power supplied to the apparatus 100 .
[0142] An apparatus engagement means 136 with two holes in c-channel 138 providing the ability for angular adjustment to the fixture 102 so as to adjust the photometry of the light along the width of the road. Further, the said apparatus 100 enables to achieve ingress protection standards wherein the standards can be IP65, IP66, and IP67, etc.
[0143] FIG. 4 illustrates a top view of solid state lighting apparatus which is used for High Bay Light application according to another exemplary embodiment of the invention. The solid state lighting apparatus 200 having five separate fixtures 202 connected to form one fixture 200 using connecting means 256 a , 256 b with help of the screws 250 . The fixture 202 is made of at least one thermally conductive material and the thermally conductive material is selected from the set of aluminum, iron, steel, copper, or combinations or alloys thereof.
[0144] Each fixture having one or more slits 208 (not shown in figure) or fins 212 , selectively punched on mounting surface 204 of the each fixture 202 for achieving additional heat dissipation and minimizing the resistance to wind. The slit 208 or fin 212 can be any shape based on the requirements.
[0145] The above said fixtures 202 is made of at least one thermally conductive sheet metal, wherein the thermally conductive sheet metal is selected from the set of aluminum, iron, steel, copper, or combinations or alloys thereof. The said fixture manufactured by computerized numerically controlled (CNC) process; the said fixture is characterized in having;
i. four separate fixtures 202 connected to form one fixture 202 , thereby achieving independent heat management system for each of the four fixtures as well as the central fixture; ii. the entire body of the fixture 202 acting as primary heat sink, wherein the fixture is designed in a manner, such that the heat dissipation is maximum in x, y coordinates laterally of the fixture due to thickness (z-axis) of the fixture 202 in the range from 0.5 to 6 mm; iii. anodization for preventing corrosion and scratches thereby increasing thermal conductivity; iv. optimized design enabling maximum light spread in the required area; v. One or more plane of the fixture 202 including the base plane of the fixture can adjustably be inclined into desired angle to achieve desired photometry; the said angle can be in the range from 0-360 degrees. vi. light spread/throw optionally will be achieved with combination of different lenses placed on the solid state light emitting sources
[0152] A hook 258 is attached at the top of the fixture 202 for fixing the said lighting apparatus 200 with the required object.
[0153] FIG. 5 illustrates a bottom view of solid state lighting apparatus which is used for Bay Light application according to another exemplary embodiment of the invention. Five metal core Printed Circuit Boards (MCPCB) 218 (not shown in the figure) mounted on each mounting surfaces of the five fixtures 202 , optionally a coated layer of copper 268 (not shown in the figure) sandwiched between the primary heat sink 202 and MCPCB 218 and an array of solid state light emitting source 220 is mounted on the MCPCBs 218 . Transparent sheets 224 are employed for covering the solid state light emitting sources 220 for preventing the insects entering the lighting apparatus, according to one embodiment of the invention, the material of the protective transparent sheet can be selected from glass and/or clear polycarbonate.
[0154] The above said MCPCB 218 comprises three layers namely bottom layer, middle (insulation) layer and top layer (not shown in the figure). The bottom layer is made up of at least one thermally conductive material selected from the set of aluminum, iron, steel, copper or combinations or alloys thereof. The bottom layer is connected with the mounting surface 204 (not shown in figure) of the fixture 202 with a thermal interface layer. The middle layer is made of electrically insulating material and used to conduct the heat from the top layer of the MCPCB 218 and not allowing conduction of electricity from the top layer to bottom layer. The top layer is made up of copper or any other metal having better heat and electrical conductivity than copper e.g. Gold plated copper. At least one solid state light emitting source 220 mounted thereon the top layer of the MCPCB 218 .
[0155] Optionally five heat dissipating panels 226 (not shown in the figures) acting as secondary heat sink are mounted thereon the reverse side of fixtures 202 wherein the heat dissipating panel 226 is made of at least one thermally conductive material selected from the set of aluminum, iron, steel, copper or combinations or alloys thereof. Optionally one or more slit 208 , or fin 212 , selectively punched on the mounting surface 204 of the fixtures 202 for achieving additional heat dissipation and minimizing the resistance to wind. The said slit 208 , or fin 212 can be any shape based on the requirements. Two layers of thermal interface material (not shown in the figures) 270 placed between primary heat sink 202 and MCPCB 218 as well as primary heat sink 202 and secondary heat sink 226 conducting the heat from primary heat sink 202 to secondary heat sink 226 . The layer of thermal interface material can be silicon rubber sheet. A power supply unit 216 (not shown in figure) is mounted inside the solid state lighting apparatus 200 which is easily serviceable, wherein the power supply units are an independent component and can be replaced in case of failures.
[0156] The said power supply unit 216 achieves a power factor >0.98 thereby reducing the reactive power. The required DC or AC voltage can be generated from AC or DC input power. The AC/DC input power can be converted into DC power supply for operation of the solid state light emitting sources by using AC to DC converter, or DC to DC converter as per requirement. Further, the said apparatus 200 enables to achieve ingress protection standards wherein the standards can be IP54, IP65, IP66, and IP67, etc.
[0157] FIG. 6 illustrates a top front view of solid state lighting apparatus which is used for flood light application according to one exemplary embodiment of the invention. The solid-state lighting apparatus 300 comprises a fixture 302 . One or more plane of the fixture 302 including the base plane of the fixture can adjustably be inclined into desired angle to achieve desired photometry; the said angle can be in the range from 0-360 degree. The fixture 302 comprises two power supply units 360 .
[0158] The above said fixture 302 is made of at least one thermally conductive sheet metal, wherein the thermally conductive sheet metal is selected from the set of aluminum, iron, steel, copper, and combinations or alloys thereof. The fixture is manufactured by computerized numerically controlled (CNC) process; the said fixture is characterized in having;
i. the entire body of the fixture 302 acting as primary heat sink, wherein the fixture is designed in a manner, such that the heat dissipation is maximum in x, y coordinates laterally of the fixture due to thickness (z-axis) of the fixture 302 in the range from 2 to 6 mm; ii. anodization for preventing corrosion and scratches thereby increasing thermal conductivity; iii. one or more power supply units 360 of fixture 302 wherein the power supply units 360 provides required DC or AC voltage to one or more solid state light emitting sources; iv. optimized design enabling maximum light spread/throw in the required area; v. optionally light spread/throw will be achieved with combination of different lenses placed on the solid state light emitting sources 320 .
[0164] The base plane of the solid state lighting apparatus 300 , A metal core Printed Circuit Board (MCPCB) mounted on base plane of fixture 302 optionally a coated layer of copper 368 (not shown in the figure) sandwiched between the base plane (primary heat sink) 302 and MCPCB 318 and an array of solid state light emitting source 320 is mounted on the MCPCB 318 . Protective transparent sheets 324 are employed for covering the solid state light emitting sources 320 . According to one embodiment of the invention, the material of the transparent sheet can be selected from glass and/or clear polycarbonate. The solid state light emitting sources 320 used in the solid state lighting apparatus 300 can be selected from the group of high power LEDs including LED, OLED, and PLED.
[0165] The above said MCPCB 318 comprises of three layers namely bottom layer, middle (insulation) layer and top layer (not shown in the figure). The bottom layer is made up of at least one thermally conductive material is selected from the set of aluminum, iron, steel, copper or combination or alloys thereof. The bottom layer is connected with the mounting surface of the fixture. The middle layer is made of insulating material and used to conduct the heat from the top layer of the MCPCB 318 and not allowing conduction of electricity from the top layer to bottom layer. The top layer is made up of copper or any other metal having better heat and electrical conductivity than copper e.g. Gold plated copper. At least one solid state light emitting source 320 mounted thereon the top layer of the MCPCB 318 .
[0166] A power supply unit 360 is mounted inside said fixture 302 , the solid state lighting apparatus 300 is easily serviceable, wherein the power supply unit 360 is an independent component and can be replaced in case of failures. The fixture 302 is covered by means of a cover plate 328 . The said power supply unit 360 achieves a power factor >0.98 thereby reducing the reactive power. The required DC or AC voltage can be generated from AC or DC input power. The AC/DC input power can be converted into DC power supply for operation of the solid state light emitting sources by using AC to DC converter, or DC to DC converter as per requirement.
[0167] According to one exemplary embodiment of the invention, covering plate 328 (shown in the FIG. 7 ) provided on top side heat dissipating area of the fixture 302 to protect it from any sort of bird droppings and/or any other droppings.
[0168] FIG. 7 illustrates an isometric front view of solid state lighting apparatus which is used for flood light application according to one exemplary embodiment of the invention.
[0169] FIG. 8 illustrates an isometric front view of solid state lighting apparatus which is used for High Mast application according to another exemplary embodiment of the invention The solid-state lighting apparatus 400 comprises a fixture 402 . Optionally one or more slits 408 , selectively punched on the fixture 402 for achieving additional heat dissipation and minimizing the resistance to wind. The said slit 408 can be any shape based on the requirements. One or more plane including the base plane of the fixture 402 can adjustably be inclined into desired angle to achieve desired photometry; the said angle can be in the range from 0-360 degree.
[0170] The above said fixture 402 is made of at least one thermally conductive sheet metal, wherein the thermally conductive sheet metal is selected from the set of aluminum, iron, steel, copper, and combinations or alloys thereof. The fixture 402 is manufactured by computerized numerically controlled (CNC) process; the said fixture is characterized in having;
i. the entire body of the fixture 402 acting as primary heat sink, wherein the fixture is designed in a manner, such that the heat dissipation is maximum in x, y coordinates laterally of the fixture due to thickness (z-axis) of the fixture 402 in the range from 0.5 to 6 mm; ii. anodization for preventing corrosion and scratches thereby increasing thermal conductivity; iii. one or more power supply units 416 (not shown in figure) fixed inside the fixture 402 wherein the power supply units 416 provides required DC or AC voltage to one or more solid state light emitting sources; iv. optimized design enabling maximum light spread/throw in the required area; v. optionally light spread/throw will be achieved with combination of different lenses placed on the solid state light emitting sources 420 . vi. combination of short range light throw plane 456 a and long range light throw plane 456 b will achieve desired photometry and coverage on the ground.
[0177] At least one metal core Printed Circuit Board (MCPCB) mounted on short range light throw plane 456 a and an array of solid state light emitting source 420 is mounted on the MCPCB 418 . Protective transparent sheet 424 (not shown in the figure) employed for covering the solid state light emitting sources 420 . According to one embodiment of the invention, the material of the transparent sheet can be selected from glass and/or clear polycarbonate. The solid state light emitting sources 420 can be selected from the group of high power LEDs including LED, OLED, and PLED.
[0178] At least one metal core Printed Circuit Board (MCPCB) 418 mounted on long range light throw plane 456 b and high power solid state light emitting sources 420 (not shown in the figure) are mounted on the MCPCB 418 , wherein lens 422 are mounted on the high power solid state light emitting sources 420 for preventing the scattering of the light in unnecessary areas and thereby directing the light in to desired area.
[0179] The above said MCPCB 418 comprises three layers namely bottom layer, middle (insulation) layer and top layer (not shown in the figure). The bottom layer is made up of at least one thermally conductive material is selected from the set of aluminum, iron, steel, copper or combination or alloys thereof. The bottom layer is connected with the mounting surface of the fixture. The middle layer is made of insulating material and used to conduct the heat from the top layer of the MCPCB 418 and not allowing conduction of electricity from the top layer to the bottom layer. The top layer is made up of copper or any other metal having better heat and electrical conductivity than copper e.g. Gold plated copper. At least one solid state light emitting source 420 mounted thereon the top layer of the MCPCB 418 .
[0180] Power supply units 416 (not shown in the figure) are mounted inside the said fixture 402 , the solid state lighting apparatus 400 is easily serviceable, wherein the power supply unit 416 is an independent component and can be replaced in case of failures. The fixture 402 is covered by means of a cover plate 428 (shown in FIG. 9 ). The said power supply unit 416 achieves a power factor >0.98 thereby reducing the reactive power. The required DC or AC voltage can be generated from AC or DC input power. The AC/DC input power can be converted into DC power supply for operation of the solid state light emitting sources by using AC to DC converter or DC to DC converter as per the requirements.
[0181] An apparatus engagement means 436 providing the ability for angular adjustment to the fixture 402 so as to adjust the photometry of the light on the ground, wherein the apparatus engagement means 436 is attached with fixture 402 by help of pins 450 (shown in FIG. 9 ). The apparatus engagement means 436 is attached with high mast pole with help of bolts via holes 454 . Further, the said apparatus 400 enables to achieve ingress protection standards wherein the standards can be IP65, IP66, and IP67, etc.
[0182] FIG. 9 illustrates an isometric back view of solid state lighting apparatus which is used for High Mast application according to another exemplary embodiment of the invention. Covering plate 428 provided on top side of heat dissipating area of the fixture 402 to protect it from any sort of bird droppings and/or any other droppings which reduces heat dissipation ability of the top side heat dissipating area of the fixture 402 .
[0183] FIG. 10 illustrates an isometric front view of solid state lighting apparatus which is used for Indoor down light application according to one exemplary embodiment of the invention. A long lasting, energy efficient, solid-state lighting apparatus having customizable design, wherein the said apparatus comprises a fixture 502 having at least one mounting surface 504 .
[0184] The above said fixture 502 is made of at least one thermally conductive sheet metal, wherein the thermally conductive sheet metal is selected from the set of aluminum, iron, steel, copper, or combinations or alloys thereof. The said fixture 502 is manufactured by computerized numerically controlled (CNC) process; the said fixture is characterized in having;
i. the entire body of the fixture 502 acting as primary heat sink, wherein the fixture is designed in a manner, such that the heat dissipation is maximum in x, y coordinates laterally of the fixture due to thickness (z-axis) of the fixture 502 in the range from 0.5 to 6 mm; ii. anodization for preventing corrosion and scratches thereby increasing thermal conductivity; iii. power supply units 516 (not shown in the figure) attached with reverse side of the fixture 502 , wherein the power supply units 516 provides required DC or AC voltage to one or more solid state light emitting sources; iv. optimized design enabling maximum light spread in the required area; v. the mounting surfaces 504 can be bend along specified bending lines to desired inclination thereby achieving desired photometry.
[0190] The base plane of the fixture 502 supports each element of the solid state lighting apparatus 500 . At least one metal core Printed Circuit Board (MCPCB) 518 mounted on the mounting surface 504 of the fixture 502 and at least one solid state light emitting sources 520 are mounted on the MCPCB 518 . The said solid state light emitting sources 520 can be selected from the group of low power or high power LEDs including LED, OLED, and PLED. Independent/common protective transparent or translucent sheet 524 (not shown in figure) may be employed for covering the solid state light emitting sources 520 for preventing the insects entering the lighting apparatus. According to one embodiment of the invention, the material of the protective transparent or translucent sheet 524 can be selected from glass, clear polycarbonate or any other material.
[0191] The above said MCPCB 518 comprises three layers namely bottom layer, middle (insulation) layer and top layer (not shown in the figure). The bottom layer is made up of at least one thermally conductive material is selected from the set of aluminum, iron, steel, copper or combination or alloys thereof. The bottom layer is connected with the mounting surface of the fixture. The middle layer is made of insulating material and used to conduct the heat from the top layer of the MCPCB 518 and not allowing conduction of electricity from the top layer to the bottom layer. The top layer is made up of copper or any other metal having better heat and electrical conductivity than copper e.g. Gold plated copper. At least one solid state light emitting source 520 mounted thereon the top layer of the MCPCB 518 .
[0192] A power supply unit 516 is mounted in protective box cum heat sink 528 (shown in FIG. 11 ) on reverse side of the fixture 502 , the solid state lighting apparatus 500 is easily serviceable, wherein the power supply unit(s) 516 are an independent component and can be replaced in case of failures. The said power supply unit 516 achieves a power factor >0.98 thereby reducing the reactive power. The required DC or AC voltage can be generated from AC or DC input power. The AC/DC input power can be converted into DC power supply for operation of the solid state light emitting sources 520 by using AC to DC converter or DC to DC converter as per the requirements. Further the said apparatus 500 enables to achieve ingress protection standards of all levels.
[0193] FIG. 11 illustrates an isometric back view of solid state lighting apparatus which is used for Indoor down light application according to one exemplary embodiment of the invention.
[0194] FIG. 12 shows cross sectional view of solid state lighting apparatuses with first level of heat management system according to one embodiment of the invention. A fixture acting as primary heat sink 602 has front side and back side. On the front side, the MCPCB 618 is attached using thermal interface 622 to further enhance the heat dissipation; Secondary heat sink 626 is provided exactly opposite to MCPCB 618 on the back side of the primary heat sink 602 . Optionally the secondary heat sink 626 can also be mounted on front side of the primary heat sink 602 as shown in FIG. 12 . As well as secondary heat sinks 626 can be put to work on the both the sides of the primary heat sink 602 simultaneously based on the requirement. Further, a well designed clamp 624 is used for clamping MCPCB 618 and secondary heat sinks 626 to the primary heat sink 602 with screws 628 and isolating bushes 630 thereby achieving desired Ingress protection. At least one solid state light emitting source 620 is mounted on the MCPCB 618 .
[0195] FIG. 13 shows cross sectional view of solid state lighting apparatuses with enhanced second level of heat management system according to another embodiment of the invention. A fixture acting as primary heat sink 702 has front side and back side and its front side is plated/coated with copper metal 732 or any other metal conductor having better heat conductivity than copper and this copper or any other metal is further plated/coated by suitable anti-corrosive heat conducting metal 734 (e.g. TIN plating on copper). On the front side, the MCPCB 718 is attached, using thermal interface 722 . To further enhance the heat dissipation; Secondary heat sink 726 is provided exactly opposite to MCPCB 718 on the back side of the primary heat sink 702 . Optionally the secondary heat sink 726 can also be mounted on front side of the primary heat sink 702 as shown in FIG. 13 . Further in an embodiment the secondary heat sinks 726 can be put to work on the both the sides of the primary heat sink 702 simultaneously based on the requirement. Further, a well designed clamp 724 is used for clamping MCPCB 718 and secondary heat sinks 726 to the primary heat sink 702 with screws 728 and isolating bushes 730 thereby achieving desired Ingress protection. At least one solid state light emitting source 720 is mounted on the MCPCB 718 .
[0196] FIG. 14 shows cross sectional view of solid state lighting apparatuses with enhanced third level of heat management system according to one embodiment of the invention. According to this embodiment of the invention, concentration of large number of Light emitting sources is achieved in a smallest possible area of the fixture. A fixture acting as first primary heat sink 802 has front side and back side. On the front side the MCPCB 818 is attached using thermal interface 822 , multiple numbers of solid state light emitting sources mounted on the MCPCB 818 , now partially thermally isolated second primary heat sink 830 is attached to the first primary heat sink 802 through thermal interface 822 . The first primary heat sink 802 on which MCPCB 818 is mounted has a cut-out opening of the suitable size in proportion with area of the MCPCB 818 , so that some percentage area of the MCPCB 818 doesn't come in contact with first primary heat sink 802 . One metallic thermal interface 832 is inserted in the cut-out opening of first primary heat sink 802 ; the said metallic thermal interface 832 connects the area of the MCPCB 818 which is not connected to first primary heat sink 802 to second primary heat sink 830 via thermal interface 822 , the said metallic thermal interface 832 is thermally isolated from the first primary heat sink 802 thereby achieving diversion of certain percentage of heat to second primary heat sink 830 from the MCPCB 818 thereby aim of concentrating solid state light emitting sources 820 in a smallest possible area without concentration of the heat in the said area is achieved.
[0197] Secondary heat sink 826 is provided exactly opposite to MCPCB 818 on the back side of the second primary heat sink 830 using thermal interface 822 . Further, a well designed clamp 824 is used for clamping MCPCB 818 and secondary heat sinks 826 to the first and second primary heat sinks 802 and 830 respectively with screws 828 and isolating bushes 830 thereby achieving desired Ingress protection.
[0198] FIG. 15 shows cross sectional view of solid state lighting apparatuses with enhanced fourth level of heat management system according to another embodiment of the invention. According to this embodiment of the invention, concentration of large number of Light emitting sources is achieved in a smallest possible area of the fixture. A fixture acting as first primary heat sink 902 has front side and back side. On the front side the MCPCB 918 is attached using thermal interface 922 , multiple numbers of solid state light emitting sources mounted on the MCPCB 918 , now fully thermally isolated second primary heat sink 930 is attached to the first primary heat sink 902 through thermal isolators 934 and/or buffer space. The first primary heat sink 902 on which MCPCB 918 is mounted has a cut-out opening of the suitable size in proportion with area of the MCPCB 918 , so that some percentage area of the MCPCB 918 doesn't come in contact with first primary heat sink 902 . One metallic thermal interface 932 is inserted in the cut-out opening of first primary heat sink 902 ; the said metallic thermal interface 932 connects the area of the MCPCB 918 which is not connected to first primary heat sink 902 to second primary heat sink 930 via thermal interface 922 , the said metallic thermal interface 932 is thermally isolated from the first primary heat sink 902 thereby achieving diversion of certain percentage of heat to second primary heat sink 930 from the MCPCB 918 thereby aim of concentrating solid state light emitting sources 920 in a smallest possible area without concentration of the heat in the said area is achieved.
[0199] Secondary heat sink 926 is provided exactly opposite to MCPCB 918 on the back side of the second primary heat sink 930 using thermal interface 922 . Further, a well designed clamp 924 is used for clamping MCPCB 918 and secondary heat sinks 926 to the first and second primary heat sinks 902 and 930 respectively with screws 928 and isolating bushes 938 thereby achieving desired Ingress protection.
[0200] In one embodiment, the fixtures for mounting solid state light emitting sources of our invention are manufactured by computerized numerically controlled process (CNC). CNC process provides accuracy to the design of the fixtures and consumes less time and power. Moreover the CNC process enables fabricators to greatly increase the productivity and to adapt change in fixture designs very quickly thereby giving rise to customized lighting fixtures. This CNC process gives rise to high level of productivity thereby making the product affordable to larger sections of society in a short time, helping to enable us in combating the Global warming threats in a shorter span of time.
[0201] CNC machine utilizes an AC servo motor to drive the ram (eliminating the hydraulic power supply and chiller). The benefits of the CNC process are the following:
a) Electrical consumption is less than one-half of comparable hydraulic machines b) Higher positioning speed improves productivity c) Space-saving design saves the cost of valuable floor space d) offers significantly faster punching speeds than mechanical turrets e) Brush table design provides scratch-free processing, and also minimizes noise during punching f) Free-standing, PC-based network CNC Control allows for flexible layouts g) instantly access part programs, multi-media help files and production schedules h) Power vacuum slug pull system virtually eliminates slug pull concerns
[0210] Our invention utilizes CNC process as a core production process for the production of complete body of thermally efficient fixtures wherein the thickness of the fixtures is optimized to achieve maximum thermal conductivity.
[0211] One of the major advantages that can be achieved by using the CNC process is that one eliminates the investment required in making the dies (required for die casting of the components). In order to produce variety of components which are a part of fixtures, creation of various die-casts is required in the existing processes and the quantum of monetary investment in the same becomes unreasonable.
[0212] In one of the preferred embodiment solid state lighting apparatuses of our invention are made by CNC process which gives a degree of flexibility to adapt the design according to the requirements without any unnecessary investment in the creation of casting moulds and dies for extrusion. High degree of customization is possible.
[0213] Another benefit of the CNC process is that it utilizes in some cases almost 100% of the sheet metal (raw material) which is fed in to the CNC machine. So the scrap which comes out is least, and can be recycled, unlike the scrap of a casting process which is difficult to recycle.
[0214] In another embodiment the thickness of the sheet metal which is fed in to the CNC machine to prepare lighting fixtures are optimized to achieve maximum possible thermal conductivity.
[0215] The fixtures of the above said apparatuses are made by using CNC Process comprising the steps of:
a. Selecting a sheet metal, wherein the said sheet metal can be selected from set of aluminum, iron, steel, copper or combinations or alloys thereof; b. Inserting the sheet metal in to a CNC machine, wherein programmed instructions cause the processor in the CNC machine to enable punching of the sheet metal in accordance to the fed design of one or more fixture and c. Optionally bending the punched fixture at one or more places using the CNC machine.
[0219] A method for manufacturing of long lasting, energy efficient, solid-state lighting apparatus having customizable design comprising steps of:
a. Feeding at least one design of the fixture in to a CNC machine along with a sheet metal; b. Punching the sheet metal as per the design to achieve one or more fixtures; c. Optionally Bending the punched fixtures at one or more places; d. Anodizing the fixture to achieve corrosion and scratch free surface; e. Fixing of nutsurts/inserts/rivet nuts (hardware) pneumatically in to the fixture; f. Mounting on the fixture at least one metal core Printed Circuit Board (MCPCB) on which at least one solid state light emitting source is already mounted; and g. Mounting one or more power supply unit in a housing of the fixture.
[0227] The method further comprises placing second primary heat sink with heat insulating sheet and/or buffer spacing on the rear side of the fixture and connecting thermally at least one solid state light emitting source from MCPCB which is mounted on first primary heat sink to second primary heat sink by way of metallic thermal interface and isolators through cut-out opening provided in the first primary heat sink; optionally placing coated layer of copper between the primary heat sink and MCPCB, wherein such coated layer may further have a means for preventing corrosion; and mounting one or more heat dissipating panels (secondary heat sinks) on the front or reverse or both side of fixture.
[0228] Further method having optionally mounting a photo sensor means and/or a motion sensor rear/front side of the fixture; optionally mounting one or more lens on one or more solid state light emitting sources; optionally covering one or more protective transparent or translucent sheet on one or more solid state light emitting sources and optionally placing one or more layers of thermal interface material between primary heat sink and MCPCB as well as primary heat sink and secondary heat sink and two or more secondary heat sinks.
[0229] Test Results and Experimental Data
[0230] Features and advantages of the solid state lighting apparatus which is used for street light application according to one exemplary embodiment of the invention are as mentioned below:
a. Helps Conserve Electricity. b. High Input Power Factor (>0.98) eliminates electrical Losses. c. Low Harmonic Distortion (THD<15%) eliminates the cable heating. d. High Color Rendering Index (CRI≧0.80) allows a clear visual identification, increases night security and also guarantees better video images from security camera systems. e. Long Life more than 50,000 Hours. f. Low Heat Emission and Ultra Low Carbon Foot Print g. 99% of the material used is recycled h. No Light Pollution as LED can be precisely directed for specific application. i. Reduces maintenance cost as LED wavelength repels insects. j. Instant ON/OFF. k. Twist lock photo cell/Day light sensor for auto ON/OFF and l. Extra spread with strong Centre Focus.
Example 1
[0243] Technical specifications of the solid state lighting apparatuses which are used for street light applications are as mentioned below:
[0000]
SL 001B
SL 001C
SL 001D
036
040
48
MODELS
SL 001A 032 AL
AL
AL
AL
Parameters
Input Voltage
85-265 VAC
Frequency Range
47-63 Hz
Power Factor
>0.98
Total Harmonic
<15%
Distortion (THD)
Power Efficiency
85%
LED
32 W
36 W
40 W
48 W
Consumption
Total Power
37 W
42 W
46 W
56 W
Consumption
LED Luminous
112 lm/w to 130 lm/w
Efficiency
Color
Ultra White: 6500 K
Temperature
(CCT)
Color Index
0.8
(CRI)
Light Source
1 Watt LED
The Maximum
120 degree Horizontal Axis; 70 degree Vertical Axis
Light Intensity
angle
Junction
60° C. ± 10% (Ta = 25° C.)/140° F. ± 10%
Temperature (Tj)
(Ta = 77° F.)
Working
−40° C. to ± 55° C./−40° F. to ± 131° F.
Temperature
Working
10%-90% RH
Humidity
Working Life
>50,000 Hrs
Lamp Housing
Aluminum
Material
Dimensions
435(L) ×
435(L) ×
435(L) ×
435(L) ×
(mm)
453(W) × 84(H)
453(W) ×
453(W) ×
453(W) ×
84(H)
84(H)
84(H)
Net Weight
4.5 Kg
4.5 Kg
5.5 Kg
5.5 Kg
IP Rating
IP 65/IP 66/IP 67
[0244] Features and advantages of the solid state lighting apparatuses which are used for Bay Light applications and flood light applications are differ from the street light application by not having twist lock photo cell for auto ON/OFF and they are having all other features and advantages of the solid state lighting apparatuses which are used for street light applications. Below is the table shows the comparison between High Pressure Sodium Lamp (HPS) and the solid state lighting apparatus which are used for street light applications of the our invention:
[0000]
Item
High Pressure Sodium Lamp
LED Streetlight
Photometric Performance
Poor: Being a round Lamp,
Excellent engineering backed
⅔ of lumens Generated falls
by efficient LED drivers
on the ground through
ensures even spreading of
Reflector causing lower lux.
light and center focus.
Also lower color Temp.
Photometric performance is
Results in poor visibility and
excellent.
dark spots between two
poles.
Radiator Performance
Poor: HPS Lamp creates heat
Excellent, (The LED color
in excess of 572 F. The color
spectrum does not radiate
spectrum of HPS creates
ultraviolet light, no infrared
ultraviolet/infrared rays.
rays, no heat, and no
radiation produced.)
Electrical Performance
Poor: High Losses, Low
Excellent: High Power Factor
Power Factor, High
eliminates losses, Low
Distortion
Distortion avoids heating in
cables
Working life
Short (<5,000 hrs)
Very high (>50,000 hrs)
Working voltage Range
Narrow (±7%)
Wide (±45%)
Power Consumption
Very High
Very Low (80 to 90% power
saving)
Startup Speed
Quite Slow (Over 10
Instant
minutes)
Strobe (Power Supply)
Alternating Current Drive
Direct current Drive
Optical Efficiency
Low (<60%)
High (>90%)
Color Index/Distinguish
Poor, Ra < 35 (The color of
Good, Ra > 80 (The color of
Features
object looks faded, Boring
object is Fresh, clearly
and poor)
identifiable And Cool effect)
Color Temperature
Quite Low (Yellow or
Ideal Color Temperature
Amber, dull feeling) 2000 K
between 5500 to 6500 K cool
white
Glare
Strong Glare
No Glare (cool and
comfortable)
Light Pollution
High Pollution
Non polluting
Heat Generation
Very High (>572° F.)
Cool light source (<140° F.)
Lampshade Turns Dark
High Dust Absorption easily
Static Proof does not
changes color of Lampshade
accumulate dust. Lamp
remains fresh
Lampshade Aging Turns
Very fast
No lampshade required
Yellow
Shockproof Performance
Lead/Gas pollution
Non polluting
Maintenance Costs
Very High, frequent
Very Low, LED life >50,000
replacement of Lamp,
hrs. LED light spectrum
rectifier circuit and cleaning/
repels insects, light lamp
removing of dead insects
looks always neat and clean.
from Lampshade
Product Cubage
Very large
Small (Slim Appearance)
Cost-effective
High maintenance and High
Very Low maintenance and
Power consumption makes
very Low power
HPS an expensive proposal
consumption makes LED an
over 10 years of usage.
excellent cost effective
lighting solutions
Conversion to Solar Street
Not Possible
Easily Possible
Light
Integrated Performance
Poor
Excellent
Example 2
[0245] Below is the table shows the cost analysis and energy saving comparison between High Pressure Sodium Lamp (HPS) and the solid state lighting apparatus which are used for street light application of the our invention:
[0246] HPS Street Light of 250 Watt Vs. Solid State Street Light of 68 Watt.
[0000]
Lamp Source/Item
HPSV Streetlight
LED Streetlight
Remark
Light Source (Watt)
250
68
Power Consumption
Lamp Power
250
76.16
Consumption (a) (Watt)
Electrical Distribution (b)
Rectifier
SMPS based
(Watt)
switching power
0
11.424
Comprehensive Cable
15
4.5696
International
Loss (6%) (c) (Watt)
standard: 5%
Transformer loss (3%) (d)
7.5
2.2848
The lowest
(Watt)
level for 100
KVA
transformer is
3%
Reactive Power
0.7
0.997
Compensation (e)(P.F.)
Subtotal Lamp's Power
389.286
94.72
Consumption (f) (Watt)
(a + b + c + d)/(e) = f
(a + b + c + d)/(e) = f
12
Daily Consumption
4.67
1.137
(= f/1000 ×
(Kwh)
above)
Calculated by
per day use in
hrs.
10 Years Consumption
17050.71429
4148.848465
(Subtotal) (Kwh)
10 Years Saving In Power
—
12901.86582
Consumption (Kwh)
Percentage of Energy
75.67
Saving
SAVINGS IN MAINTENANCE IS NOT CONSIDERED,
EARNING THROUGH CARBON CREDIT IS NOT CONSIDERED.
Example 3
HPS Street Light of 150 Watt Vs. Solid State Street Light of 48 Watt
[0247]
[0000]
Lamp Source/ Item
HPSV Streetlight
LED Streetlight
Remark
Light Source (Watt)
150
48
Power Consumption
Lamp Power
150
53.76
Consumption (a) (Watt)
Electrical Distribution (b)
Rectifier
SMPS based
(Watt)
switching power
0
8.064
Comprehensive Cable
9
3.2256
International
Loss (6%) (c) (Watt)
standard: 5%
Transformer loss (3%) (d)
4.5
1.6128
The lowest
(Watt)
level for 100
KVA
transformer is
3%
Reactive Power
0.7
0.997
Compensation (e)(P.F.)
Subtotal Lamp's Power
233.571
66.86
Consumption (f) (Watt)
(a + b + c + d)/(e) = f
(a + b + c + d)/(e) = f
12
Daily Consumption
2.80
0.802
(= f/1000 ×
(Kwh)
above)
Calculated by
per day use in
hrs.
10 Years Consumption
17050.71429
2928.598917
(Subtotal) (Kwh)
10 Years Saving In Power
—
7301.829655
Consumption (Kwh)
Percentage of Energy
71.37
Saving
SAVINGS IN MAINTENANCE IS NOT CONSIDERED,
EARNING THROUGH CARBON CREDIT IS NOT CONSIDERED.
Example 4
[0248] The results of experiments conducted regarding the Flux distribution in upward and downward directions are as mentioned below
[0249] Materials and Methods:
[0250] Catalog Number: 68 WATT LED STREET LIGHT
[0251] Luminaire: Formed and machined aluminum housing, clear glass enclosures.
[0252] Lamp: 62 White LEDs—60 with clear plastic optics and 2 with clear glass optics below
[0253] LED Power Supply; ONE SSUDR/01/80 W
[0254] Electrical Values: 120.0VAC, 0.7302 A, 87.53 W, PF=0.999
[0255] Luminaire efficacy: 64.3 Lumens/Watt
[0256] Note: This test was performed using the calibrated photodector method of absolute photometry*
[0257] *Data was acquired using the calibrated photodetector method of absolute photometry. A UDT model #211 photodetector and udt model #S370 optometer combination were used as a standard. A spectral mismatch correction factor was employed based on the spectral responsivity of the photodetector and the spectral power distribution of the test subject.
[0258] Flux Distribution
[0000]
Lumens
Downward
Upward
Totals
House Side
2397.72
0.01
2397.73
Street Side
3218.86
15.85
3234.71
Totals
5616.58
15.86
5632.44
Example 5
Luminaire Testing Specification and Report
[0259] Catalog Number: 68 W LED Street Light
[0260] Luminaire: Extruded and machined aluminum housing, clear glass enclosures.
[0261] Lamp: 62 White LEDs—60 with clear plastic optics and 2 with clear glass optics.
[0262] LED Power Supply: One SSL/DR/01/80 W
[0263] Luminaire Efficacy: 66.0 Lumens/Watt
[0264] The other details are illustrated in FIGS. 16 and 17
[0000]
LUMINAIRE
LUMINAIRE
ZONE
LUMENS
LUMENS
FORWARD
3219
57.1
LIGHT
FL (0°-30°)
773
13.7
FM (30°-60°)
1647
29.2
FH (60°-80°)
688
12.2
FVH (80°-90°)
111
2.0
BACK
2398
42.6
LIGHT
BL (0°-30°)
847
15.0
BM (30°-60°)
1217
21.6
BH (60°-80°)
326
5.8
BVH (80°-90°)
9
0.2
UPLIGHT
16
0.3
UL (90°-100°)
16
0.3
UH (100°-180°)
0
0.0
TRAPPED LIGHT
NA
NA
Example 6A
[0265] Another experiment conducted shows comparison of Luminous efficiency of a 20 W LED lighting device with tube lights of 40 W at different angles.
[0000]
Fitting of tube
Fitting of street lights of 20 W LED
lights of 40 W
3 m
6 m
10 m
3 m
6 m
10 m
Angle
distance
distance
distance
distance
distance
distance
Straight
14 lux
7 lux
3 lux
6 lux
3 lux
1 lux
Connection
45 Deg
11 lux
7 lux
3 lux
NA
NA
NA
fitting
90 Deg
11 lux
7 lux
3 lux
NA
NA
NA
fitting
Example 6B
[0266] Another experiment conducted shows comparison of Luminous efficiency of a 45 W LED lighting device with sodium lights of 250 W at different angles.
[0000]
Fitting of Sodium
Fitting of street lights of 45 W LED
lights of 250 W
3 m
6 m
10 m
3 m
6 m
10 m
Angle
distance
distance
distance
distance
distance
distance
Straight
26 lux
17 lux
6 lux
22 lux
13 lux
6 lux
Connection
45 Deg
26 lux
14 lux
5 lux
22 lux
13 lux
5 lux
fitting
90 Deg
10 lux
8 lux
3 lux
6 lux
5 lux
NA
fitting
[0267] Financial Benefits:
[0268] 1. 67% to 72% saving in the electricity consumption.
[0269] 2. Minimum maintenance charge.
[0270] It is found through estimation that if LED street lights are implemented in all the places through out the world, the benefits will be as below:
1) Saving in electricity 1.9×1020 Joules 2) Remarkable decrease in consumption of electricity. 3) Financially, saving of 1.83 Trillion dollars 4) Prevention of addition of 10.68 Giga tons of carbon dioxide to the environment. 5) The electricity produced in about 280 electricity production centres, which is being used in illuminating the street lights, can be used for different purposes.
Example 7
[0276] Another experiment was conducted which shows the comparison result between High Pressure Sodium Lamp (HPS) and our solid state lighting apparatus.
[0000]
Model
48 W LED Street Light vs 255 H.P.
Sodium Vapor Lamp
Test Procedure referred
T-EQP/035
Test facilities used:
Nomenclature
Make/Model
SI. Number
1) Single & Three Phase Analyzer
Infratek/106A-
01054012
3/0.05
2) Power Quality Analyzer
Fluke/434
DM910008
3) Digital Illumination Meter
Yokogawa/510 02
020191
[0277] Test Results
[0000]
Sr.
Test
No
Parameters
Test method/Requirements
Observation
1
Power
When the LED Lamp is operated with Rate
50.04 w
Consumption
Voltage 230 volt A.C. and Rated frequency 50 Hz,
the total power consumption shall be
measured
2
Input Power
Input power factor shall be measured at rated
0.997
Factor
voltage 230 volt A.C. and Rated frequency 50 Hz
3
Input Voltage
When the LED Lamp is operated with input
45 volt-200
Range
voltage range from minimum to maximum
lux
operating range, output lux shall be measured at
96 volt-550 lux
approximately 5 feet height
230 volt-560
lux
263 volt-560
lux
4
Distortion
The total harmonic distortion of the input
18.2%
Level (Total
current shall be meausred When the LED Lamp
Harmonics
is operated at its rated voltage 230 volt A.C.
Distortion of
and Rated frequency 50 Hz
input current)
1
Power
When the HPS Lamp is operated with Rate
255 W
Consumption
Voltage 230 volt A.C. and Rated frequency 50 Hz,
the total power consumption shall be
measured
2
Input Power
Input power factor shall be measured at rated
0.395
Factor
voltage 230 volt A.C. and Rated frequency 50 Hz
3
Input Voltage
When the HPS Lamp is operated with input
183 volt-326
Range
voltage range from minimum to maximum
lux
operating range, output lux shall be measured at
230 volt-1800
approximately 5 feet height
lux
258 volt-2600
lux
4
Distortion
The total harmonic distortion of the input
13.0%
Level (Total
current shall be meausred When the HPS Lamp
Harmonics
is operated at its rated voltage 230 volt A.C.
Distortion of
and Rated frequency 50 Hz
input current)
Example 8
[0278] Yet another on-site Installation experimental data is as follows:
[0000]
INSTALLATION DATA
Voltage: 120
EXISTING
FIX.
EXISTING
EXISTING
RPL. FIX.
POST RPL
POST
LOCATION
SL#
TYPE
LOAD
Fe
TYPE
LOAD
RPL Fe
Sidney St.
31442
150 w
2.63a
2.43
48 w LED
.52a
3.33
HPS
Sidney St.
21592
150 w
2.58a
2.14
48 w LED
.52a
2.62
HPS
Sidney St.
25339
150 w
2.10a
2.76
48 w LED
.52a
2.63
HPS
[0279] The solid state lighting apparatuses of our invention have applications and customized for utilities including but not limited to stand alone lighting purposes. Industrial Indoor lighting purposes, indoor domestic commercial purposes, street light purposes, flood light purposes, high mast purposes, stadiums and other public spaces like air ports, etc.
[0280] The preceding description has been presented with reference to various embodiments of the invention. Persons skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described apparatuses and methods of operation can be practiced without meaningfully departing from the principle, spirit and scope of this invention.
ADVANTAGES OF THE INVENTION
[0281] The solid state lighting apparatuses of the proposed invention having the following advantages
a) Helps Conserve Electricity. b) High Input Power Factor (0.98) eliminates electrical Losses. c) Low Harmonic Distortion (THD<15%): Eliminates the cable heating caused by high level of Harmonic distortion of conventional Lights. d) High Color Rendering Index (CRI≧0.80): The natural color spectrum of white LED Street light of our invention allows a clear visual identification of forms and colors. This increases night security and also guarantees better video images from security camera systems. e) Long Life (>50,000 Hours): While most conventional gas discharge lamps can only be used for 5000 hours, the LED Street Light of our invention has an average life span of more than 50000 hours. f) Low Heat Emission and Ultra Low Carbon Foot Print: To reduce carbon footprint is the need of the hour. The next ten years are very crucial for the survival of this Planet. Introduction and implementation of Energy efficient Projects is an absolute MUST. By introducing LEDs in the Illumination Sector, more than 80% of energy can be saved. The conventional Lights generate a lot of heat, due to which the Air conditioners get more loaded and the compressors run for a longer time. LEDs help in reducing heat and therefore save the run time of Air conditioners. In turn, there is an indirect savings in energy in this case (INDOOR APPLICATION). g) Environmentally Friendly and Recognized Green Technology: LED street light of our invention are environmentally friendly right from the selection of raw material, the manufacturing process, the function of energy saving on installation, long Life and 99% of the fixture can be recycled after the life span. The LED Lights are recognized as GREEN TECHNOLOGY Products Globally. h) No Light Pollution: Because LED Street light of our invention can be precisely directed, Light pollution is minimal. This does not only help astronomers observing the night skies, it also protects many animals as well as human health and i) Insect-Friendliness: Since the street Light of LED of our invention is less appealing to many night-active insects, almost no insects die in the lamps, which also greatly reduces cleaning and maintenance costs. j) Scrap value at end of life cycle is substantial k) Welding operation is done to keep minimal metal grain structure undisturbed.
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The invention provides lighting apparatuses which are power efficient, environment friendly and long lasting and can be manufactured with high degree of speed, accuracy and flexibility. The lighting apparatuses are easily serviceable and can be produced, transported economically and have higher economical value even on completion of life term of the lighting apparatuses. The present invention reduce the waste of raw material thereby utilizing maximum percentage raw material for produce solid state lighting fixtures using CAD and CNC process and provides retrofitting lighting apparatuses which can be replaced without making considerable changes in existing infrastructure.
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FIELD OF THE INVENTION
The invention is in the field of instruments for measuring the thickness of a web and, more specifically, the invention relates to a roller caliper gauge which is especially adapted for use in controlling the nip of calendar stacks via actuator systems such as forced air or induction heating systems for regulation of product thickness of a moving web.
BACKGROUND OF THE INVENTION
In the manufacture of paper such as newsprint, one of the finishing operations performed is that of calendaring. One of the variables which is controlled in the course of the calendaring operation to govern the character of the finished product is the thickness of the paper being calendared. One system which is employed to control the web caliper is an arrangement of air showers comprising a plurality of valves which are regulated to control the shower of air directed against the web.
In the prior art, a reel hardness sensor is used to generate a signal which controls the air valves. More particularly, the reel hardness sensor is a disc containing a piezoelectric crystal. The disc rotates against the paper reel to cause the crystal to put out a signal as a measure of reel hardness.
Accurate caliper measurement is found to be of particular importance in newsprint roll building. The system of the prior art described hereinabove does not permit of measurement to afford the desired degree of control of peak to peak profiles as is desirable in newsprint roll building. In addition, in the case of a calendar stack control using reel hardness control, the usage of hot and cold air is excessive owing to the inherent time delay between a corrective calendar stack change and the subsequent result as seen on the reel hardness profile.
SUMMARY OF THE INVENTION
One object of our invention is to provide a roller caliper gauge which is especially adapted for use in newsprint roll building.
Another object of our invention is to provide a roller caliper gauge which affords a closer control of peak to peak profiles in newsprint roll building than do systems of the prior art.
Still another object of our invention is to provide a roller caliper gauge adapted to achieve peak to peak profiles of less than 3 microns in the manufacture of newsprint as compared with 8.0 to 10 microns using the reel hardness control arrangement of the prior art.
Yet another object of our invention is to provide a roller caliper gauge which reduces usage of hot and cold air in a calendar stack control with air showers to only 15 percent of maximum from about 65 percent of maximum when using reel hardness control as in the prior art.
Still another object of our invention is to provide a roller caliper gauge which substantially eliminates the inherent time delay between a corrective stack change and the subsequent result as seen on the reel hardness profile in systems of the prior art.
A still further object of our invention is to provide an on-line caliper sensor which is capable of measuring newsprint profiles at speeds in excess of 3,000 ft. per minute with an absolute accuracy of better than ± one micron.
A still further object of our invention is to provide a roller caliper gauge which affords a precise measurement of thickness on a high-speed paper web.
Yet another object of our invention is to provide a roller caliper gauge which is adapted for use in measuring the thickness of a web having an adhesive coating on one side.
A still further object of our invention is to provide a roller caliper gauge for use on a very wide web where it is difficult to achieve a close tolerance on the relative lateral positioning of the two sides of the sensor.
Other and further objects of our invention will appear from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings to which reference is made in the instant specification and which are to be read in conjunction therewith and in which like reference characters are used to indicate like parts in the various views:
FIG. 1 is an elevation of our roller caliper gauge with parts shown in section.
FIG. 2 is a fragmentary sectional view with parts broken away of the sensor head of our roller caliper gauge.
FIG. 3 is a bottom plan of the sensor head of our roller caliper gauge.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, our roller caliper gauge which is adapted to make a precise measurement of the thickness of a moving web W indicated in dot-dash lines in FIG. 1, includes an upper head indicated generally by the reference character 10 carried by a support 12. The upper head 10 cooperates with a lower head indicated generally by the reference character 14 carried by a support 16. The web W passes over an entry roller 18 supported on space pedestals, one pedestal 20 of which is shown in FIG. 1 as it moves into the space between heads 10 and 14. After leaving the space between the heads, the web travels over an exit roller 22 supported on a pair of spaced pedestals, one pedestal 24 of which is shown in FIG. 1.
The upper head 10 includes an upper head housing upper half 26, the upper end of which is closed by an end plate 28 secured to the upper housing half 26 by any suitable means such as by screws 30. An upper head housing lower half 32 partially telescopes within the upper half 26 and is attached thereto by any suitable means, such for example as screws 34. The lower end of the lower half 32 is closed by a lower end plate 36 to be described more fully hereinbelow. Screws or the like 38 secure the end plate 36 in the head 32.
Plate 36 carries a pair of spaced roller bearing supports 40 and 42 secured to the plate by any suitable means such as by welding or the like. A pair of rollers 44 and 46 are rotatably carried by the supports 40 and 42 in a manner to be described.
Each of the rollers 44 and 46 has a shaft 48 secured in the supports 40 and 42. Each shaft 48 carries a pair of spaced bearings 50 and 52, the outer rings of which are received in the ends of the associated roller such as the roller 46 shown in FIG. 2.
We form the lower end plate 36 with a housing 54 extending downwardly between the rollers 44 and 46 at a location about halfway along the lengths of the rollers. Housing 54 receives an inductive coil 56 embedded in a suitable potting compound 58. A plug 60 retains the coil 56 within the housing 54. A spring 62 is disposed between the plug 60 and the coil properly to position the coil within the housing 54. Respective electrical leads 64 and 66 from the coil 56 pass through suitable openings in the plug 60 to the interior of the upper head 10 and to a connector 68 carried by the upper end plate 28. Suitable connections can be made from the connector 68 to the external circuitry.
The lower head 14 includes a lower half 70 which for purposes of ease in manufacture is substantially identical to the upper half 26 of the upper head 10. We secure a lower end plate 72 in the lower end of housing half 70 by any suitable means, such for example as by screws 74. Lower head 14 includes an upper half 76 which is retained in assembled relationship with the lower half 70 by means of screws 78, the inner ends of which are formed as pins 80 disposed in slots 82 in the outer surface of the upper half 76.
The lower head 14 includes an upper end plate 84. A diaphragm 86 extending over the upper surface of the plate 84 is retained in position on the plate 84 by a retaining ring 88 secured to the plate 84 by screws 90 or the like. Diaphragm 86 carries a pressure pad or platen 92 which is adapted to be actuated in a manner to be described to hold the web W in engagement with the rollers 44 and 46.
We form the upper surface of the plate 84 with an annular passage 94 to which air under pressure is fed through an inlet passage 96 by means of a hose 98. We connect the hose 98 to a hose 100 leading to a suitable supply (not shown) of air under pressure. A relief passage 102 having a diameter considerably smaller than that of the passage 98 connects the annular space 94 to the interior of the lower head 14.
Respective upper and lower fittings 104 and 106 screwed into the upper and lower plates 84 and 72 receive the ends of a spring 108 which draws the upper plate 84 downwardly to bring a peripheral flange 110 on the retaining ring 88 into engagement with the upper end of the housing upper half 76. The head 112 may be turned to adjust the tension of the spring 108 to the degree desired for proper operation of the device.
In operation of our roller caliper gauge in a system, for example, for controlling the calendar stack nip in a high speed newsprint-forming machine, head 10 is set up with relation to the rollers 18 and 22 so that the distance "a" between a plane tangent to the rollers 44 and 46 and a plane tangent to the rollers 18 and 22 is about 0.040 inches. The head 10 is arranged so that the distance "b" between a plane tangent to the rollers 44 and 46 and the plane in which the lower surface of housing 54 lies is about 0.007 inches. The current from a suitable alternating current source 114 is passed through the coil 56. In response to a change in the inductance of the coil resulting from a variation in the thickness of the web W a control system 116 puts out a suitable signal which is a measure of thickness and which may be used, for example, to control the calendar air shower valves.
Advantages inherent in inductive measuring techniques in general are their immunity to noise and their ability to operate in harsh environments. However, problems arise when applying such techniques to a moving paper web. Factors such as vibration, low web strength, high web speeds, adhesive coatings, embedded slugs and shives, lateral positioning errors and wide temperature excursions all contribute to runability problems such as sheet breaks, holes or streaking, and measurement errors. Our system provides a solution to such problems.
When our system is running, air under pressure is supplied to the space provided by recess 94 to move the pad or reference platen 92 upwardly into engagement with the under side of the web W to move the upper surface of the web into engagement with the rollers 44 and 46. This engagement of the upper surface of the web is limited to line contact with the rollers 44 and 46.
The restriction of contact between the web and the non-rolling side of the sensor system to the two lines of closest approach between the rollers 44 and 46 on one side and the flat surface of the platen 92 on the other side appreciably reduces the lateral drag force as compared with sensors of the prior art. If the rollers 44 and 46 were not present, atmospheric pressure would hold the web in close contact with the central portion of the flat surface of platen 92 creating drag which by itself would be enough to break the paper web W at high speeds. In designs of the prior art where contact with the web is on both sides, the additional drag caused by the resulting pinching effect can break the web at lower speeds and where stronger papers are being made.
An additional defect resulting from the pinching effect characteristic of two-sided contacting sensor designs, was the requirement that the reference platen had to be of low mass to accommodate the presence of shives and slugs in the web which tended to cause frequent sheet breaks. In our arrangement these paper contaminants no longer cause problems and the reference platen 92 can now be made thicker and more temperature stable resulting in increased accuracy.
For the same reason, the reference platen can be made larger in diameter, thus decreasing its sensitivity to lateral alignment errors inherent in wide or infrequently serviced scanning mechanisms. Our system thus contributes to improved initial and long-term precision as compared with arrangements of the prior art.
Preferably, to improve measurement stability we hold the housing 54 at a constant temperature using a heater 118 and a temperature sensing element 120 connected in a feedback circuit. Our system provides good control of the measuring coil temperature, owing to the fact that it is separated from the web W by a heat insulating air gap "b" of approximately 7 to 10/1000 of an inch. This improved temperature regulation results in improved accuracy because of smaller measurement shifts going on and off sheet, smaller temperature gradients within the coil housing 54, less heater power required to maintain a given temperature and a less critical relationship between the heater set point and the web temperature. We attach the rollers 44 and 46 to the upper head 10 with sufficient space around them to avoid attracting water into the housing via the Magnus effect which results in an area of low pressure at the trailing edge of a high speed roller. The sheet forming rollers 18 and 22 smooth out the pass line of the web in the presence of flutter and wrinkles in the web, as is well known to persons skilled in the art.
In operation of the system in the manufacture of newsprint at high speeds, the rollers 44 and 46 press about 1/8 of an inch into the web pass line as defined by the sheet-forming rollers 18 and 22. This distance may be reduced for stiffer, heavier weight sheets or increased for soft sheets.
The Magnus effect contributes to the reduction of drag by relieving the atmospheric pressure which would normally keep the reference platen in contact with the moving web. As a result, the web contacts the reference platen only at the two lines of closest approach of the platen 92 and the rollers 44 and 46.
The bleed passage 102 enables the platen to move more freely, allows the use of a more rugged pressure gauge and improves the operation of the pressure regulator.
Optional components (not shown) of a type well-known in the art, such as pneumatic, hydraulic or electromechanical actuators, to move the system on or off sheet may be included. The measuring and temperature control circuits employed with our system use standard inductive and thermoelectric techniques well-known to those skilled in the art. Calibration may be performed using stationary, laboratory-calibrated standards made of glass, mica, mylar or other stable non-conductive materials. Conductive materials such as stainless steel, brass or titanium may be used with magnetically permeable reference targets if suitable allowances are made which are dependent upon the particular gauge elements employed.
It will be seen that we have accomplished the objects of our invention. We have provided a roller caliper gauge which is especially adapted for use on high speed webs. Our roller caliper gauge affords a closer control of peak to peak profiles than do reel hardness control systems of the prior art. Our roller caliper gauge appreciably reduces hot and cold air usage in a system for controlling a calendar stack with air showers. Our on-line caliper sensor is capable of measuring newsprint profiles at speeds in excess of 3000 per minute with an accuracy of better than ± one micron. Our gauge is adapted for use in measuring the thickness of a web having a sticky coating on one side. It is useful on a very wide web where it is difficult to achieve a close tolerance on the relative lateral positioning of the two sides of the sensor.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.
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A roller caliper gauge for providing an accurate measurement of the thickness of a high speed web of paper or the like in which a proximity device located within a housing disposed between a pair of rollers on a head on one side of the web is responsive to a web in an operative position adjacent to the housing. A platen on a head on the other side of the housing is pneumatically moved toward the rollers to cause the web to make line contact with the rollers when in the operative position.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of and claims priority from U.S. patent application Ser. No. 09/473,765, filed on Dec. 29, 1999 now U.S. Pat. No. 7,114,820.
TECHNOLOGICAL FIELD
The invention relates to uniform backlighting of flat-panel displays by means of a thin light pipe.
BACKGROUND OF THE INVENTION
Modern electronic devices often have a liquid crystal display to transmit information to the user. In order to make the display readable even in twilight or darkness, the display is generally lit by means of light emitting diodes (LED), but especially in portable devices powered by a battery and/or an accumulator, this also has a shortening effect on the actual operating time of the device. In addition, the requirement for uniform brightness of the display is essential in view of readability, but it increases power consumption to compensate for the loss of light caused by diffuser plates and the like. Instead of using opaque baffles, an alternative is to use a diffractive light pipe structure to conduct the light in the favorable direction, from the light source to the display, whereby there is also more freedom for the disposition of components.
With regard to known techniques related to the art of the invention, reference is made to solutions described in connection with the prior art ( FIGS. 1 to 2 ). A known arrangement is to use ‘thick’, ‘plate-like’ light pipes, on one end of which there is a light source, and on one flat side of the plate with the largest area and/or inside the light pipe there is a lighted object for achieving uniform illumination thereof. It is also known that when the light pipe is made thinner, the distribution of the illumination of the display may become less advantageous. However, there is very little extra room in modern mobile stations and other equipment provided with a display, and thick light pipe structures cannot be used in them without a negative effect on the usability of the device. Thick elements also mean increased material costs to the manufacturer and thereby more pressure on pricing.
There are also known techniques with a thin, plate-like light pipe, from one end of which a light source emits light to the space between the upper and lower surfaces of the light pipe. The bottom of the light pipe may be randomly roughened, e.g. the lower surface of a plate-like light pipe, when the display or a corresponding object to be illuminated is positioned above the upper surface of the light pipe, in the direction of the viewer. The purpose of the roughening is to distribute the light to scatter as uniformly as possible in the direction of the display. There may also be a diffuser, a reflector or a corresponding extra layer under the roughened surface to direct the light that has passed through the roughening back to the light pipe, through it and from it in the direction of the display to increase its illumination.
Although it is the total reflection principle that the propagating light obeys on its way through the light pipe, the random roughening on the light pipe surface may cause problems to the homogeneity of the light, especially at the opposite end to the light source. In other words, much less light comes to the other end of the display than left the first end of the light pipe at the light source. Increasing the number of light sources as well as increasing their power, combined with the use of diffuser plates between the light pipe and the display and/or the light source and the light pipe improve the uniformity of illumination, but also increase power consumption and space requirements.
FIG. 1A illustrates the lighting arrangement of display 1 by using a thin, flat light pipe 3 , the lower surface 4 of which is randomly roughened. FIG. 1B represents the local efficiency of the light source, by which light produced by the light source can be converted to backlighting (outcoupling efficiency η hereinafter). The local outcoupling efficiency is represented as a function of location, the coordinate measured from the source end of the light pipe. Because the outcoupling efficiency itself is constant all the way, the brightness of the display as seen by an outside observer is according to FIG. 1C , which thus represents the local brightness of a slice of the display as a function of the distance measured from the end at the light source. FIG. 1D shows in principle how individual rays 5 and 6 leaving a light source L 1 propagate in a light pipe 3 and are converted into background light at points 5 A to 5 E, 6 A and 6 B.
Another technique for evening out the inhomogeneous brightness, which changes as a function of location as shown in FIG. 1C , is to change the local outcoupling efficiency η as a function of distance by placing dots at which the light is scattered or reflected on the top or bottom of the light pipe. The dots are, for instance, small lenses, which are located at long intermediate distances in the first end of the light source and at shorter intermediate distances in the other end so that there is a smaller difference in brightness B between the first and second end of the display. FIG. 2 illustrates a known arrangement like that described above for illuminating a flat-panel display 7 with a light pipe 9 , in which arrangement the lower surface of the light pipe 9 is covered with lenses. The amount of light 8 is greater in the first end of the light pipe 9 near the light source L 2 than in the second, opposite end. Because the purpose is to illuminate the display more uniformly, and the local outcoupling efficiency η of the light depends on the local number of scattering and/or reflecting lenses, it is advantageous to make the density of the optical elements smaller near the light source than far from it. To improve the lighting still more, a reflector 10 can be used to return unfavorably directed light back to the direction of the display 7 .
Estimating the transmission properties of the light pipe either by experimental or calculatory methods by using known techniques is practically impossible because of the great number of prototypes needed and the number and small size of the lenses, whereby obtaining an acceptable, optimal result with the known technique is questionable.
SUMMARY OF THE INVENTION
It is an objective of the invention to provide a new light pipe, which provides uniform illumination of the background of the display and which is easy to manufacture.
For producing the backlighting of a flat-panel display, a patterned light pipe is used in the invention, in which light pipe at least one surface has been treated to achieve diffraction properties, by which the local outcoupling efficiency of the light pipe can be changed as a function of the distance and/or wavelength measured from the light source. The outcoupling efficiency of the light pipe depends on at least one parameter, which describes the diffraction properties of the surface. The local outcoupling efficiency is influenced by quantities characterizing the diffractive surface, such as the periodicity of the surface formations of the patterns of the diffraction profile, the period d, the fill factor c and/or the height/depth of the ridges/grooves of the profile. Surface formations that are suitable as basic diffraction profiles according to a preferred embodiment of the invention include binary, rectangular wave, sinusoidal, and/or triangular wave, and by forming suitable combinations thereof the properties of the invention can be optimized for each application.
In addition, according to a preferred embodiment of the invention, the properties of a diffractive light pipe can be improved by dividing its surface to form pixels, in which its gridded properties are locally uniform. Especially at the end at the light source, the orientation of the pixels can be used advantageously to improve the distribution of the light and thus the brightness of the backlighting of the display.
An example of preferred embodiments of the invention is a binary, gridded like diffraction structure of the surface.
The patterns on the light pipe surface can be, for instance, of two types of diffractive pixels, which are both of the binary type. Some of the pixels in the vicinity of the light source are oriented so that the diffraction profiles, and thus the pixels themselves are at 90° rotational geometry to each other, when the imaginary axis of rotation is parallel with the normal of the surface of the light pipe. In addition, modified basic profiles or combinations thereof can be used.
Other preferred embodiments of the invention are presented in the subclaims.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be described in detail with reference to the following drawings, in which
FIG. 1 shows a known arrangement based on random roughening in order to provide lighting,
FIG. 2 shows a known arrangement, which is based on the use of lens-like scatterers instead of random roughening for directing the light to the object,
FIG. 3 shows a light pipe arrangement according to a preferred embodiment of the invention,
FIG. 4 shows a detail of a light pipe according to a preferred embodiment of the invention,
FIG. 5 shows the diffraction and reflection taking place in a light pipe according to a preferred embodiment of the invention,
FIG. 6 represents the local outcoupling efficiency η of the diffractive structure as a function of the distance measured from the light source,
FIG. 7 shows light pipes according to a preferred embodiment of the invention,
FIG. 8 illustrates the basic profiles of the grooves and ridges of the diffractive structure of a light pipe according to a preferred embodiment of the invention,
FIG. 9 illustrates the pixelized, diffractive basic structure of a light pipe according to a preferred embodiment of the invention,
FIG. 10 represents a modified profile and/or pixel structure of a light pipe according to a preferred embodiment of the invention.
FIGS. 1 and 2 represent methods formerly known from prior art for backlighting.
FIGS. 1A , 2 , 3 A, 5 A, 7 A, 7 B, 7 C, 9 A, 9 B, 10 A represent the principles of the patterns of the microstructure of the diffraction profile geometry, and are thus not necessarily in the right scale in relation to the macroscopic dimensions or thickness of the light pipe.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3A shows how the illumination of a flat-panel display 301 can be arranged by means of a light pipe 303 according to a preferred embodiment of the invention. The light pipe 303 has a binarized diffraction surface, in which the geometrical properties of the surface profile change when the distance from the light source increases. Locally, the geometrical changes are small as compared to the adjacent formations, and they approximate at a certain accuracy a grid structure, in which the grid constant changes as a function of location. The light 302 is equally strong throughout the whole diffractive light pipe element 303 , although individual rays of light 302 are stronger at the first end 303 A of the light pipe 303 close to the light source L 3 than at the opposite end 303 B. The local outcoupling efficiency η of the diffraction element 303 C has been changed by utilizing its dependence on the fill factor c. In addition, it is advantageous for the invention to use, for instance, a Lambertian white reflector 304 below the light pipe 303 to reflect or scatter the part of the light which has passed through the bottom of the light pipe 303 in the wrong direction back to the light pipe 303 to be used for the illumination of the display 301 .
FIG. 3B represents the local outcoupling efficiency η of the diffractive construction according to a preferred embodiment of the invention as the function of a location measured from the light source L 3 .
FIG. 3C represents the local brightness B of the display achieved by a diffractive structure according to a preferred embodiment of the invention as the function of a location measured from the light source L 3 , when the outcoupling efficiency of FIG. 3B has been compensated for achieving a constant brightness by changing the geometry of the diffractive profile, e.g. the fill factor. Brightness is constant, and thus independent of location.
The length 30 mm of the horizontal axis in FIGS. 3B and 3C is only an example, and the length and/or width of a real display as well as other dimensions of the light pipe can differ from this substantially.
FIG. 3D illustrates the passage in the light pipe 313 of the rays 315 , 16 A and 16 B of light, which have left the light source L 3 , and their conversion into rays 15 A to 15 E, which are transmitted out from the light pipe. Note that in the transmissions and reflections taking place at points 15 A to 15 E, the macroscopic brightness of the light equals that in FIG. 3C outside the light pipe as seen by an observer in the direction of the display, although with regard to an individual ray of light, in a microscopic scale, the intensity of the ray of light is reduced as the function of a distance measured from the light source, also in consequence of multiple reflections and/or transmissions. Uniform brightness is achieved by directing a larger part of the locally available light out from the light source by means of a diffractive structure according to a preferred embodiment of the invention ( FIG. 3A ).
FIG. 4 illustrates the structure of the surface geometry of a diffractive light pipe in one of the preferred embodiments of the invention. Characteristic parameters of a binary diffraction profile are cycle length d, fill factor c and ridge height h of the profile n 1 is the refractive index of the light pipe material, and n 2 is the refractive index of the medium between the light pipe and the display.
FIG. 5A illustrates the propagation of light with the principle of total reflection in a diffractive light pipe according to the invention, in view of a ray of light, which passes in the direction α in relation to the normal of the inner surface of the light pipe. A detail 517 , which illustrates the passage of the ray of light at one period of the diffractive structure, is delimited by a dashed line from the light pipe.
FIG. 5B is an enlargement of the detail 517 in FIG. 5A . The optical geometry is the same as in FIG. 5A . When a ray of light hits the diffractive profile d, its diffraction is represented by angles of transmission and reflection, β pT and β pR , respectively, certain orders of which are marked in FIG. 5B . For instance, 0 R is the ordinary reflection of the principal ray.
FIG. 6 shows the outcoupling efficiency η of the diffractive surface as the function of the fill factor c standardized with the period d, in other words, the dependence of the outcoupling efficiency as the function of the ratio c/d. The dependence is represented for three angles of incidence of the principal ray: 60° (continuous line), 70° (dashed line) and 80° (dotted line). The results shown in the figure are based on calculated mean values of the transverse electric and magnetic fields of the propagating light. Rays of light, which are directly transmitted or advantageously reflected have been taken into account. The absorption of the white reflector plate on the bottom of the light pipe has not been taken into account in the calculation.
FIG. 7 shows, by way of example, preferable embodiments of the invention achieved by using a binary profile of the light pipe ( FIG. 8 ). FIG. 7A illustrates the principle of a diffractive structure 718 grooved transversely to the propagation direction of the light as seen from above, the direction of the display. FIGS. 7B and 7C show the principles of light pipe sections 719 , 720 made by curved grooving. A dotted line A–B shows the places of the grooves C and ridges of the diffraction profile and the geometric principle as a viewer would see them when looking from the side of the diffraction element 718 , 719 , 720 (bottom or top edge in the figure) on the level of the surface of the light pipe, perpendicular to the propagation direction of the light. Other diffraction profiles ( FIGS. 8 and 10 ) are also possible in alight pipe section 718 , 719 , 720 either as such or by combination. Possible differences in brightness on the display can be equalized by using a wavelike groove structure ( FIG. 7C ).
FIG. 8 illustrates alternative diffraction profiles for the surface formation of a light pipe (and pixels contained in it) according to a preferred embodiment of the invention, and related parameters, which influence the optical properties of the surface. FIG. 8A shows a binary groove/ridge profile for a diffraction surface and/or its pixels. In the figure, h is the height of the ridges, c is the fill factor and d is the length of the groove/ridge period of the profile. FIG. 8B shows a sinusoidal profile, in which h is the height of the ridge, d is the length of the period and c is the fill factor as defined on the basis of the half-wave width of the sinusoidal ridge. As an example of a multilevel diffraction profile structure, FIG. 8C shows a three-level structure with its characteristic parameters: h 1 and h 2 are the heights of the levels of the grooves of a locally gridded structure, d is the length of the period and c is the fill factor. FIG. 8D shows a detail of a diffractive profile structure provided with triangular ridges, in which the height of the ridge is h, the length of the period d and the fill factor c as defined on the basis of the half-wave width of the ridge as in FIG. 8B . The fill factor can also be varied by changing the apex angle of the triangular ridge. In addition to these, other profiles can also be used. For instance, profiles that are achieved by combining at least two basic profiles shown by FIG. 8 can be used either as such, by combining and/or modifying them and/or combining with them mathematically represented periodical forms, which can be described by means of parameters associated with the basic profiles. An example of this is a diffraction profile, which is obtained from a sinusoidal wave profile ( FIG. 8B ) by combining with it other sinusoidal profiles, the period lengths and fill factors of which are functions of the mathematical value of the period length and fill factor or phase of the form of a basic profile (e.g. FIGS. 8A to 8D ).
FIG. 9 shows a preferable embodiment of the invention, in which the diffraction surface of the light pipe consists of pixel-like patterns. The purpose of the pixelization and/or orientation of the pixels is to influence the uniformity of the light at the first end of the light pipe by means of diffraction, and thus to improve the properties of the diffraction surface of the light pipe. The diffractive surface can be divided into pixels so that the pixels closest to the light source form (orientation B) an equalizing portion 902 , in which the light of the light source is distributed as a result of diffraction to form a macroscopically uniform lighting. The pixels of such an equalizing portion 902 based on diffraction are preferably positioned according to the orientation B and even in different geometry in relation to the period length and the fill factor or in relation to another degree of freedom, which is essential with regard to the application. The purpose of pixels 903 , 904 , which are further away in the direction of propagation of the light are either to couple light out from the pipe section in order to produce lighting (pixel 903 , orientation A) and/or to distribute the light coming from the light source to make it still more uniform (pixel 904 , orientation B). It is advantageous to use more light distributing pixels 902 , 904 in the vicinity of the light source 901 than further from it. In this diffraction structure according to a preferred embodiment of the invention used here as an example, the purposes of the pixels are determined on the basis of their orientation ( FIG. 9A ).
FIG. 9B shows the propagation of light in a pixel, which equalizes the lighting. As a result of diffraction, the incoming ray of light is distributed in many directions, which are described by means of orders representing intensity maximums. The directions of the diffraction maximums corresponding to the orders ±2, ±1 and 0, which also correspond to the propagation directions of the rays of light, are marked in the figure.
The pixels can be locally homogeneous, and/or the fill factor and period can change within them as the function of a quantity measured from the light source, such as distance. Although the pixelizing is represented here in a rectangular application, it can also be applied in other geometrical shapes, such as the groove patterns shown in FIG. 7 , when an uniform backlighting of a display is optimized by the placement of the light source.
FIG. 10 shows modifications of the basic profiles of a diffractive light pipe according to a preferred embodiment of the invention. FIG. 10A represents a profile, which is binary, but can also be derived from the basic forms of FIG. 8 , as applied to the pixelization of a diffraction surface according to FIG. 9 , for example. Some of the pixels in FIG. 10A are deflected from the level of the surface of the light pipe (horizontal) to the angle Φ, some to the angle φ, and some are parallel with the surface of the light pipe. After the presentation of the FIGS. 10A and 10B , it will naturally be clear to a person skilled in the art that in a pixelization, which is incorporated in the structure of a macroscopic piece, the angles of deflection and the relation of the number of deflected pixels to the number of non-deflected pixels in a light pipe also has an effect on its diffraction properties. FIG. 10B shows a diffraction profile according to a preferred embodiment of the invention as derived from the basic forms of FIG. 8 , when the surface formations are deflected to the angle Θ from the level determined by a pixel shown in FIG. 10A . It will also be clear to a person skilled in the art that structures, which are skewed in relation to the peak of the surface formation, are also possible in a diffraction profile. FIG. 10 represents the principles of the geometry of diffraction profiles, and thus the size and/or angles of deflection of the pixels are not necessarily in the right scale to the periods and/or heights of the surface formations.
The theory related to the prior art about the behavior of light in diffraction, about the effect of the parameters of microgeometry, the properties of the light source and its distance has been dealt with, e.g. in the book Micro-optics: Elements, systems and applications, edited by Hans Peter Herzig, Taylor and Francis, 1997, and especially in chapter 2: Diffraction Theory of Microrelief Gratings by Jari Turunen.
There are also other publications related to the prior art, such as Illumination light pipe using micro-optics as diffuser, Proceedings Europto series, Holographic and Diffractive Techniques, SPIE 2951, 146–155. 1996.
A diffraction phenomenon is observed in monochromatic light when the light meets a piece or a group of pieces (grating), the characteristic dimension of which is in the range of the wavelength of light. The incoming ray of light is divided, and its direction of propagation is changed. The new directions of the rays of light, both for the reflected and the transmitted rays, can be expressed by means of the wavelength, its integer orders and the characteristic dimension of the piece participating in the diffraction. Formulas (1) and (2) can be applied in the calculation of direction angles corresponding to the orders of the propagation directions of the diffracted light. For transmitted orders we have:
sin β pT = p λ n 2 d + n 1 n 2 sin α ( 1 )
and for the reflected:
sin β pR = p λ n 2 d + sin α ( 2 )
where α is the angle of direction of the incoming ray of light in relation to the normal of the surface, β pT is the angle of direction of the order p of the conducted light, and β pR is the angle of direction of the order p of the reflected light, p is the order of the ray of light, l is the wavelength of the primary, incoming light, n 1 is the optical refractive index of the diffractive light pipe, n 2 is the refractive index of the medium surrounding the light pipe, and b is the period of the diffractive structure.
An embodiment of the invention is described here as an example. A prototype is made of the light pipe, with the purpose of illuminating a flat-panel display. Three sources of light are used, the wavelength of the transmitted light being 570 nm. The optimal diffractive structure of the light pipe is implemented with the parameters of the table below.
Quantity
Value
Period
length
2.5396
µm
Groove
depth
0.5311
µm
Fill
ratio
c
/
d
0.2
–0
.5
The period length of the diffractive profile is preferably designed between 1.5 μm–3.5 μm. A suitable depth of the grooves in a diffractive structure according to a preferred embodiment of the invention is from 0.3 to 0.7 μm, i.e. in the range of the wavelength, when visible light is used. On the basis of this, it will be clear to a person skilled in the art that by using suitable materials, a technique according to the preferred embodiments of the invention can also be scaled to other electromagnetic wave movements, the wavelength of which differs from that of visible light, such as applications and problems related to medical and/or technical X-raying and/or analysis methods.
By means of the preferred embodiments of the invention, the outcoupling efficiency of the diffraction surface of the light pipe can be increased as a function of the distance measured from the light source to compensate for the reduction of the amount of light used for illumination when moving away from the light source. When the outcoupling efficiency is increased at the same rate as the amount of light available decreases, an uniform brightness of the display is achieved.
The local outcoupling efficiency of the surface of a light pipe according to a preferred embodiment of the invention can be regulated by changing the period of the diffraction profile and/or the depth of the grooves. The order of the mode of scattering and the scattering angle of the outcoupling rays of light can also be regulated by changing the period of the diffraction profile. The dependence of the illumination on the angle of incidence of the ray of light is stronger at the source end of the light pipe than at the opposite end. The distribution of the illumination observed on the surface of the light pipe can be equalized by changing the period of the profile of the diffraction structure.
In addition, the diffraction profiles and/or even whole pixels can be modified suitably by turning them in relation to three possible degrees of freedom, and/or by tilting the diffraction profile or its elements, elongated surface formations and/or their local formations. Within an individual pixel, the different parts of the diffraction profile can be turned in relation to straight lines parallel with the surface to an angle suitable for the application ( FIG. 10B ). Even whole pixels can be deflected in angles which differ from the level of the surface of the display ( FIG. 10A ). The diffraction structure and/or grouping of the light pipe and/or the pixels, grooves and/or ridges contained thereby can also be designed according to fractal geometry.
A surface according to a preferred embodiment of the invention in a diffractive light pipe can be manufactured directly on the surface by using nanolitographic methods with an electron beam, for instance, or by molding the light pipe. A preferable material for manufacturing the light pipe is polymethyl-methacrylate PMMA. An advantage of the invention is that a light pipe according to it can be manufactured by mass production means and methods based on extrusion, for instance. A further advantage of the invention is that its elaboration for the application can be carried out quickly by constructing a diffractive structure on a selected substrate, whereby the diffractive structure is also indiscernible for the user.
It is also possible to use more complicated profiles than those described in a preferred embodiment of the invention ( FIGS. 8 to 10 ) for uniform distribution of light, but when the structure becomes more complicated, the manufacturing costs are also likely to increase. Complicated techniques are described at least in the publications by Noponen et al (1992): ‘Synthetic diffractive optics in the resonance domain’, J. Opt. Soc. Am. A9 1206–1213. and Vasara et al (1992): Applied Optics 31, 3320–3336.
The diffractive structure on the surface of the light pipe can be made either on one side of the light pipe section or on both sides thereof. Diffraction surfaces made on both sides need not be identical. The invention is especially suitable for use in connection with a light emitting diode (LED), for example. The invention is also very suitable for use with a technique based on liquid crystal displays (LCD), for instance.
It is advantageous if all energy from the light source can be converted into the lighting of the background of the display. That requirement is met most advantageously with regard to the application of preferred embodiments of the invention when a LED is used as the light source, but also other light sources such as lasers and/or white light sources can be used. It is known for a person skilled in the art that the light can be filtered and/or polarized. It is also known for a person skilled in the art that use of combined techniques of white light as filtered and/or polarized can be used, including combinations thereof, in which structures that store light energy are used, in other words, solutions based on phosphorescence and/or fluorescence. In order to minimize the amount of light outcoupled from the sides and ends of the light pipe section, the edges of the light pipe section can also be coated with clear and/or diffuse films or treated with a grinding suitable for the purpose.
In order to make the propagation time of the ray of light in the light pipe section as long as possible, (that is, to maximize the amount of light that is outcoupled for effective use), the light pipe section can be shaped as an asymmetric trapezium or the like, whereby the energy of the rays of light propagating in the direction of the diffractive surface and being thus otherwise led out from the ends can be utilized for lighting.
Uniform distribution of light at the first end of the light pipe can be influenced by pixelization of the diffraction structure ( FIG. 9 ). A special portion 902 can be made at the source end of the light pipe, with the purpose of equalizing the distribution of the light from the light source ( FIG. 9A ).
The distribution of light based on diffraction in an appropriate pixel 902 ( FIG. 9 ) will be demonstrated in the following example. When diffraction of light is discussed in this connection, the directions of the intensity maximums mean the propagation directions of the diffracted rays of light, in which light can be seen as a result of diffraction. When the period length of a grating in the diffraction structure is 2.5 μm, the depth of the grooves 0.5 μm, the fill factor 0.5 and the wavelength of incoming light is 470 nm with an angle of incidence α=60°, intensity maximums are seen in directions that differ from the direction of the 0th order of the transmitted principal ray, which are 8.2°, 16.1°, 23.5° for the corresponding orders ±1, ±2 and ±3, respectively. The deviations from the principal ray of the same orders with the wavelength 570 nm are ±10°, ±19.3 and ±27.8, respectively. When the angle of incidence of the principal ray increases, the diffraction angles corresponding to the intensity maximums decrease to some extent. For example, when the wavelength is 470 nm but the angle of incidence is 80°, a ray of light of the 1st order is seen in the direction 7.3°. In addition, the distribution of the light energy between rays of light representing different diffraction orders depends strongly on the angle of incidence of the principal ray.
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A light pipe includes a surface provided with a pattern that has diffractive properties, where the pattern has uniform, mutually different areas on the surface such that some of the areas are configured to distribute light from a light input end of the light pipe to form macroscopically uniform distribution of light and some other areas are configured to couple light out from the light pipe in order to produce lighting, and where the relative proportion of surface covered by areas configured to distribute light is arranged to decrease in relation to increase of distance from the light input end.
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This application is a division of pending application Ser. No. 495,541, filed May 17, 1983 now U.S. Pat. No. 4,499,263.
This invention relates to a method for separating vapor from solid particles containing same. In another aspect, the invention relates to a method and apparatus for separating vaporous diluent or solvent from solid polymer particles.
In many polymerization processes for the production of normally solid polymer, a stream is formed which is a slurry of the particulate polymer suspended in a liquid medium, ordinarily the reaction diluent. For example, in the polymerization of ethylene in a hydrocarbon diluent under controlled conditions of temperature and pressure, a slurry of nonagglomerating solids and diluent can be formed. This process is called particle form polymerization. In this process, or other processes in which the polymer is prepared in solution and subsequently precipitated upon the slurry, there is a problem of separating the solid polymer from the liquid diluent. A convenient method to carry out the separation is by flashing the hydrocarbon into a vapor by reducing the pressure on the slurry. However, this method does not ordinarily affect complete removal of the hydrocarbon from the polymer and the remaining solids retain residual amounts of diluent which must be removed before the polymer can be handled in the atmosphere with safety. This is particularly important to prevent explosion when the polymer is to be subsequently transferred by pneumatic conveying means.
OBJECTS OF THE INVENTION
It is an object of this invention to provide method and apparatus for separating vapor from particles which contain the vapor.
It is another object of the invention to provide method and apparatus for the drying of particles such as polymer particles containing residual or adherent diluent or solvent.
Yet another object of this invention is to provide method and apparatus for transferring solids containing residual diluent to a pneumatic polymer transfer line.
SUMMARY OF THE INVENTION
According to certain aspects of the present invention, there is provided an apparatus comprising of substantially enclosed first chamber, a means for introducing particulate material into an upper portion of the substantially enclosed first chamber from a higher pressure zone while preventing pressurization of said substantially enclosed first chamber to the higher pressure. A sparger is positioned in a lower portion of the substantially enclosed first chamber. A conduit means is connected to the upper portion of the substantially enclosed first chamber and establishes a path to the sparger. A substantially enclosed second chamber is associated with the substantially enclosed first chamber in such a manner so that it can receive particulate material by gravity feed from the first chamber. A second sparger is positioned in a lower portion of the substantially enclosed second chamber. A vapor outlet is connected to an upper portion of the substantially enclosed second chamber. A means for metering particulate material from a lower portion of the substantially enclosed second chamber is also provided.
In another aspect of the present invention, there is provided a process comprising introducing polymer particles containing a first amount of diluent or solvent into a first zone. A first mixture of inert gas and diluent or solvent vapor at a first temperature is introduced into the first zone to evaporate a first portion of the diluent or solvent from the polymer particles. From the first zone, there is withdrawn a second mixture of inert gas and diluent or solvent vapor. A first portion of this second mixture is recycled to the first zone. Polymer particles containing a second amount of diluent or solvent are withdrawn from the first zone and introduced into a second zone. In the second zone, the introduction of inert gas separates a second portion of the diluent or solvent from the polymer particles and forms a third mixture of inert gas and diluent or solvent vapor. A first portion of the third mixture is withdrawn from the second zone. A second portion of the third mixture is withdrawn from the second zone and used to form the first mixture. The polymer particles containing a third amount of diluent or solvent are withdrawn from the second zone from whence they can be passed to pneumatic conveying means if desired. Preferably, the process is further characterized by countercurrent flow of gases and polymer particles, in which embodiment the process can be conveniently carried out in the above described apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE schematically illustrates certain features of one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides an improved process for the removal of vapor from particles. The invention has special utility for the removal of residual diluent or solvent from polymers, especially polymers which are produced or recovered in slurry form. In some cases, the diluent or solvent can be the monomer itself, in whole or in part. Generally, however, the polymer is produced in the presence of liquid hydrocarbon diluents under polymerization process conditions. Suitable diluents include paraffins, preferably containing less than about 12 carbon atoms, monomers, which are generally olefins provided they are liquid at polymerization conditions or soluble in the liquid medium. Naphthenic hydrocarbons having 5 or 6 carbon atoms in the ring, such as cyclohexane, methylcyclopentane, ethylcyclohexane, and the like may also be employed. Other suitable liquid hydrocarbon diluents which can be utilized to conduct particle form polymerization include propane, propylene, n-butane, i-butane, i-octane, and the like.
The polymers to which the present invention is applicable include most any olefinic polymer such as polyethylene, polypropylene, and other polymers and copolymers of 1-olefins having up to about 8 carbon atoms and no branching near the double bond than the four position. The size of the polymer particle is not particularly important in the invention and commonly the polymer to be dried has an aggregate size distribution ranging from fine powder such as about 200 mesh to granular particles as large as 1/4 inch or more. Particles larger than a 1/4 inch however are generally not preferred because it is more difficult for the diluent or solvent to diffuse from such large particles.
The polymerization reaction to produce such particles can be conducted in most any type of reactor. The two most common types of reactors for producing a slurry of polymer particles in solvent or diluent are the stirred and loop reactors. Of the two, the loop reactor with a settling leg is preferred. One of the advantages of such a reactor is that it provides a settled slurry from the reactor which reduces the amount of solvent which would otherwise have to be removed. Of particular importance are those processes in which ethylene, or mixtures of ethylene with other unsaturated hydrocarbons, are contacted with a suspension of chromium oxide-containing catalysts in a liquid hydrocarbon diluent, the contacting occurring at a temperature such that substantially all of the polymer produced is insoluble in the diluent and in solid particle form, the particles being substantially non-tacky and non-glutenative and suspended in the liquid diluent. Examples of suitable materials for the monomer or comonomer include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 1,3-butadiene. The liquid hydrocarbon diluents which are suitable include paraffins having 3 to 12, preferably 3 to 8 carbon atoms per molecule, such as propane, n-butane, n-pentane, isopentane, n-hexane, isooctane, and the like, most preferably isobutane. The temperature of the polymerization depends upon the hydrocarbon diluent chosen and other factors such as the catalyst and monomer and is generally in the range of about 230° F. and below. The pressure of the reaction is sufficient to maintain the diluent in a liquid phase and is normally about 100 to 700 psia. The reactor effluent, which generally contains 30 to 60 weight percent solids formed by the polymerization process is treated according to the present invention.
In the prior art, the reactor effluent was first flashed to remove a major portion of the solvent and then passed to dryer, such as indirectly heated auger dryers, to remove additional solvent. As a final step, the polymer would be purged with inert gas to remove residual solvent. It was found that a simple purge such as the final devolatilization step was not completely satisfactory. After a dried granular polymer has been purged with rather large volumes of inert gas, a significant amount of solvent may remain with the polymer. This is probably due to two factors: (1) some channeling of the inert gas through the bed reduces the efficiency of the purge and (2) solvent dissolved in solid polymer does not have sufficient driving force and time to diffuse to the surface of the particles and hence into the void passages from which it can be swept out by the purge.
According to certain aspects of the present invention, an apparatus 2 comprises a substantially enclosed first chamber 4 and a substantially enclosed second chamber 6. The substantially enclosed second chamber 6 is preferably associated with the substantially enclosed first chamber 4 so as to gravity feed from the substantially enclosed first chamber 4. Preferably, a standpipe 8 connects the chamber 4 with the chamber 6. More preferably, the chamber 4 and the chamber 6 are formed from an elongated vessel 10 having a generally cylindrical inside wall 12 so that it exhibits a generally circular cross section. A partition 14 divides the inside of the vessel 10 into the first chamber 4 and the second chamber 6. The partition 14 is preferably generally funnel-shaped and depends from the inside wall 12 of the vessel 10 with the mouth of the funnel facing the first chamber 4, the generally frusto conical inside of the funnel defining the lower end of the first chamber 4, and the outside of the funnel defining the upper end of the second chamber 6. The lower portion of the funnel forms the standpipe 8. If desired, a feeder such as a star valve 9 can be positioned in the standpipe 8. Preferably, the vessel 10 is generally vertically oriented so that material in the first chamber 4 will gravity feed into the second chamber 6.
A means 16 for introducing particulate material into the chamber 4 while preventing excessive pressurization of the chamber 4 is provided for introducing particulate material into an upper portion of the substantially enclosed first chamber 4. Preferably, the means 16 comprises a surge vessel 18 having an inlet 20 which is associated with an inlet valve 22 and an outlet 24 which is associated with an outlet valve 26, the outlet 24 being connected with the upper portion of the first chamber 4 when the valve 26 is open. The inlet 20 is connected to a source 28 of polymer particles containing residual solvent or vapor when the valve 22 is open. A stepper 30 is connected to the valve 22 by an appropriate linkage which can be electrical, hydraulic, or pneumatic for example to sequentially open and close the valve 22. The valve 26 is also connected to a stepper, preferably the stepper 30 by suitable linkage so that it also sequentially opens and closes. The stepper 30 is operable to send impulses to the valve 22 and the valve 26 to sequentially open the valve 22, close the valve 22, open the valve 26, and close the valve 26, and then to repeat the sequence. The source 28 of particulate material will generally be combined with fluid, usually gas and residual liquid, and be in an elevated pressure. The surge vessel 18 and associated valve mechanisms provide a means for withdrawing slugs of particulate material from the source 28 without allowing uncontrolled depressurization of zone 28.
A first sparger 32 for the distribution of vapor is positioned in a lower portion of the substantially enclosed first chamber 4. A first conduit means 34 connects the upper portion of the substantially enclosed first chamber 4 with the first sparger 32. Preferably, the conduit means 34 comprises a blower 36 connected to the upper portion of the chamber 4 by a second conduit means 38, a heater 40; a third conduit means 42 connecting the heater 40 and the blower 36 and a fourth conduit means 44 connecting the heater 40 and the sparger 32. The second conduit means 38 preferably comprises a filter 46, a first conduit 48 connecting the filter 46 with the upper portion of the chamber 4, and a second conduit 50 connecting the filter 46 and the blower 36. The third conduit means 42 preferably comprises a three-way valve 52, a third conduit 54 connecting the blower and the three-way valve and a fourth conduit 56 connecting the three-way valve 52 and the heater 40. The fourth conduit means 44 preferably comprises a fifth conduit 58 which connects the heater 40 and the sparger 32. The three-way valve 52 is preferably further connected to a sixth conduit 60, which is routed for proper and safe disposal or further processing as desired. A means 62 is associated with the three-way valve 52 and the conduit 48 by suitable linkages for detecting the pressure in the conduit 48 and manipulating the three-way valve 52 responsively to the thus detected pressure. A preferred means 62 comprises a pressure integral controller.
Further preferably, a second three-way valve 64 is disposed in the fourth conduit 56 between the first three-way valve 52 and the heater 40 and a seventh conduit 66 which by-passes the heater 40 is connected to the three-way valve 64 and the conduit 58. A means 68 is associated with the fifth conduit 58 downstream of the connection between the seventh conduit 66 and the conduit 58 for detecting the temperature in the fifth conduit and manipulating the second three-way valve 64 responsively to the thus detected temperature to control the flows through the heater 40 and the seventh conduit 66. Preferably, the means 68 comprises a temperature integral controller which is associated with the fifth conduit 58 and, via a suitable linkage, with the three-way valve 64.
A second sparger 70 is positioned in a lower portion of the substantially enclosed second chamber 6. The sparger 70 is connected to a source of inert gas 72 by a conduit means 74 which is preferably provided with a means for controlling fluid flow therethrough which in the illustrated embodiment comprises a flow integral controller 76 associated with the conduit means 74 so as to detect fluid flow therethrough and connected by appropriate linkage to a valve 78 positioned in the conduit means 74 so as to control the flow through the conduit means 74. The means 76 is operable to detect the flow through the conduit means 74 and manipulate the valve 78 responsively thereto.
A conduit means 80 is connected to an upper portion of the chamber 6. Preferably, the conduit means 80 comprises a conduit 82, a conduit 84 and a valve 86 connecting the conduit 82 with the conduit 84. The conduit 84 can be sent to the flare or used as fuel. A means 88 for detecting the pressure within the conduit means 82 is associated therewith for detecting the pressure in the conduit means 82 and, via suitable linkage, manipulating the valve 86 responsively to the thus detected pressure. Preferably, the means 88 comprises a pressure integral controller 90 which senses the pressure within the conduit 82, compares the thus detected pressure to a set point signal 92 produced as is hereinafter described and provides a signal 94 which acts upon the valve 86. The signal 92 is received by the means 88 from a means 94 connected with the conduit 60 for analyzing the contents of the sixth conduit 60 and producing the signal 92 which is representative of some portion of the thus detected contents. A suitable means 94 can be any conventional process analyzer for measuring the concentration of a component in a gas stream, for example, a chromatographic analyzer such as an Optichrom 2100 manufactured by Applied Automation, Inc., Bartlesville, Okla. Together the means 94, the means 88, and the linkage 94 provide a means for manipulating the valve 86, which is preferably a motor valve responsively to the concentration of a gaseous component, preferably an inert gas in the conduit 60. A means 96 is connected to a lower portion of the second chamber 6 for metering a particulate material from the lower portion. The means 96 preferably comprises a star valve or the like 98 and a conduit 100 connecting a lower portion of the chamber 6 with the star valve 98. Preferably, the star valve 98 is positioned so as to pass particulate material from the chamber 6 and to a pneumatic conveying device 102. A motor 104 is connected to the star valve 98 and is operable to manipulate the star valve 98. The motor 104 is actuated or controlled in response to a signal 106 which is received from a level detector 108 which is associated with the first chamber 4 to detect the level of particulate material therein and produce the signal 106 which is representative of the thus detected level. A suitable level controller 108 is a radiation type level controller such as is commercially available from Texas Nuclear of Texas.
According to further aspects of the invention, there is provided a process comprising introducing polymer particles and a first amount of diluent or solvent into a first zone, such as the chamber 4, preferably the upper portion thereof. Preferably, the polymer particles undergo a pressure drop as they enter the first zone so that a portion of the diluent or solvent flashes to vapor and can be removed via conduit means 34 for example. The first amount of diluent or solvent will usually be in the range of from about 0.3 to 3 percent by weight of the polymer particles and contained diluent or solvent. The pressure drop undergone by the particles will be to some extent dependent upon the diluent or solvent employed. Where the polymer particle is formed from polyethylene and the diluent or solvent comprises isobutane, the polymer particles enter the first zone from a pressure within the range of from about 17 to about 35 psia. The pressure in the first zone is generally within the range of from about 14.8 psia to about 17 psia.
A first mixture of inert gas and diluent or solvent vapor at a first temperature is introduced into the first zone to evaporate a first portion of the diluent or solvent from the polymer particles and is preferably introduced into a lower portion of the first zone. By using hot gas in the first purge step, the temperature of the polymer and its contained diluent or solvent is raised by some 5° to 50° F. or so, thereby raising the vapor pressure of the solvent and increasing the driving force for solvent to diffuse from the polymer particles. Preferably, the first mixture of inert gas and diluent or solvent is introduced into the chamber 4 and flows upwardly countercurrently to the polymer particles through the standpipe 8. Preferably, the size of the first mixture stream flowing up standpipe 8 is small. It can be controlled by selecting the height of the standpipe 8 or by providing it with a restriction such as the valve 9, which can be a star valve. The polymer particles containing a second amount of diluent or solvent are withdrawn from a lower portion of the first zone, preferably through the standpipe 8 while being contacted countercurrently with the second portion of the third mixture, which forms the first mixture for purging the particles.
A second mixture of inert gas and diluent or solvent vapor is withdrawn from the first zone, preferably from the upper portion thereof such as via conduit 48. A first portion of the second mixture is recycled to the first zone 4 via the means 34 preferably being introduced into a lower portion thereof through the sparger 32. Recirculation of the vapors to the first zone permits the solvent concentration in the inert carrier to build up to a controlled level, generally in the range of 2 to 80 mole percent solvent, usually 2 to 20 mole percent solvent. While the presence of solvent in the inert gas tends to reduce the diffusional driving force for solvent to leave the polymer somewhat, it has the benefit of making it more economical to recover solvent from the gas which is bled off via line 60 for example. As an aid to diluent or solvent removal from the particles contained within the chamber 4, it is preferable to heat the first portion of the second mixture prior to recycling it to the lower portion of the first zone. This is conveniently accomplished in the disclosed invention by passing the portion of the gases to be recycled through the heater 40. Where isobutane is the diluent to be removed from the particles, the second mixture is heated to a temperature within the range of from about 150° F. to about 200° F. prior to recycle to the lower portion of the first zone. The recovery of diluent or solvent from conduit 60 can be carried out by a conventional means such as condensation, absorption, or adsorption. Inert gas from solvent recovery may be recycled to source 72 if desired.
The polymer particles which now have been depleted in diluent or solvent to contain a second amount thereof are introduced into a second zone which can be defined by the chamber 6. Preferably, relatively warm polymer from the first zone passes by gravity through the standpipe 8 into the second zone 6 where it will be purged with fresh inert gas which desirably contains essentially no solvent. A convenient inert gas for this purpose is nitrogen although other types of inert gases can be used if desired. The inert gas is introduced into the second zone to separate a second portion of the diluent or solvent from the polymer particles and form a third mixture of inert gas and diluent or solvent vapor. The inert gas from the source 72 may be at ambient temperature, but optionally it may be preheated by means not shown. When it is preheated, the limiting temperature for preheating the inert gas to either of the purged zones is the softening point of the polymer. However, it must be borne in mind that the softening point of the polymer may be lowered by the presence of dissolved solvent.
A first portion of the third mixture of inert gas and diluent or solvent vapor is withdrawn from the second zone via conduit 82, for example. The flow rate of the first portion of the third mixture is preferably regulated responsively to the concentration of one of diluent or solvent or inert gas being carried by the conduit 60 for diluent or solvent recovery. Generally, the analyzer 94 will be set to maintain a concentration of diluent or solvent vapor in the line 60 at a preselected amount in the range of from about 2 to about 20 mole percent diluent or solvent by providing the signal 92 to manipulate the valve 86 which controls flow through line 82. An important control feature of the invention thus comprises detecting the concentration of at least one of inert gas, diluent or solvent vapor in the second portion of the second mixture and withdrawing the first portion of the third mixture from the second zone 6 responsively to the thus detected concentration.
The second portion of the third mixture is withdrawn from the zone defined by the chamber 6 and used to form the first mixture which preferably flows countercurrently to the polymer particles up the standpipe 8.
Polymer particles containing a third amount of diluent or solvent are then withdrawn from the second zone, preferably from the lower portion thereof via conduit 100 for example. Generally, the third amount of diluent or solvent will be within the range of from about 0.001 to about 0.1 weight percent of the polymer and diluent or solvent withdrawn together from the second zone. Preferably, the polymer particles are withdrawn from the second zone responsively to the detected level of polymer particles in the first zone defined by the chamber 4. This is conveniently carried out according certain aspects of the invention by detecting a level of polymer particles in the first zone such as by level controller 108 and withdrawing the polymer particles from the second zone responsively to the detected level by manipulating the speed of the motor 104 driving the star valve 98 by the signal 106. The polymer particles can then be picked up by the pneumatic conveying means 102 and conveyed for further processing steps.
Residence time of the polymer in each purge zone is preferably in the range of 30 to 60 minutes, and a height to diameter ratio for the beds of about 5:1 is desirable. Gas flow rate through the beds is preferably in the range of about 5 to about 10 volumes/volume/hour. Purge zone pressures are preferably near but above atmospheric pressure.
The invention is illustrated by the following calculated example.
CALCULATED EXAMPLE
Powdered high density polyethylene containing 1.5 weight percent isobutane solvent is fed from a polymer dryer to a surge vessel operating at 160° F. (71° C.) and 20.7 psia (143 kPa). Polymer flow in and out of the surge vessel is controlled by conventional means such as timer-actuated ball valves or star valve feeders. Polymer flows from the surge vessel at a rate of 20,000 lb/hr of dry polymer (containing 300 lb/hr of isobutane solvent) into the first purge zone operating at 14.8 psia (102 kPa) and 160° to 180° F. (71° to 82° C.). Residence time for the polymer in the first purge zone is about 30 to 60 minutes.
From the first purge zone the polymer passes to the second purge zone which operates at a slightly higher pressure than the first purge zone. Temperature in the second purge zone ranges from about 100° to 180° F. (38° to 82° C.). Polymer residence time in the second purge zone is about 30 minutes. Purged polymer containing no significant amount of solvent passes via a star valve feeder to a transport and storage system. Nitrogen at about 100° F. (38° C.) is introduced into the lower section of the second purge zone via a flow controller and a suitable sparger to obtain good flow distribution of gas through the bed at a rate of 300 lb/hr. A small stream of this nitrogen is also introduced into the polymer discharge line just above the star valve. Purge nitrogen containing 100 lb/hr of isobutane solvent is removed from the second purge zone via a pressure controller which is reset by an ARC on the purge gas removed from the primary purge. Thus the backpressure is controlled at a pressure such that nitrogen passes from the second purge zone to the first purge zone in only sufficient amount to maintain the isobutane solvent concentration in the purge from the first purge zone at an essentially constant concentration. The ARC is any conventional process analyzer for measuring the concentration of a hydrocarbon in a gas stream, for example, a chromatographic analyzer system such as an Optichrom 2100 manufactured by Applied Automation, Inc., Bartlesville, Okla.
Purge gas from the first purge zone at 160° F. (71° C.) and 14.8 psia (102 kPa) is filtered and compressed by a blower to 21 psia (145 kPa) and 200° F. (93° C.). The stream is split by a three-way motor valve manipulated by a pressure controller to maintain a constant back pressure on the first purge zone. Vent gas rate is 833 lb/hr nitrogen containing 200 lb/hr of isobutane solvent vapor; recirculating gas at a rate of 1,500 lb/hr is cooled to 180° F. (82° C.) and 15 psia (103 kPa) and injected into the lower portion of the first purge zone through a gas distributor. Polymer bed level is maintained in the first purge zone by a radiation-type level controller such as is made by Texas Nuclear of Texas.
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A system for recovering vapor, such as residual isobutane, from powder, such as polyethylene powder, comprises surge vessel and a two-compartment purge column. The polymer passes through the surge vessel by means of valves such as ball valves on the inlet and outlet of the surge vessel. Hot vapor, such as isobutane, is used to strip a large portion of the residual isobutane from the polyethylene in the top section of the purge column. Part of the isobutane leaving the column goes to a hydrocarbon recovery section and part is heated and recycled as the stripping medium. In the bottom section, nitrogen is used to strip the remaining isobutane from the polymer. An analyzer controller sensing nitrogen in the isobutane stream to recovery controls pressure in the bottom section by manipulating a valve in the nitrogen off-gas line form the bottom section to control the nitrogen content of the isobutane stream being recycled as stripping medium.
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This application is a continuation of application Ser. No. 08/178,734, filed Jan. 7, 1994, now abandoned.
FIELD OF THE INVENTION
The present invention relates to methods for pasteurizing shell eggs. More particularly the present invention relates to methods for reducing or eliminating Salmonella from shell eggs and for improving the storage capabilities of shell eggs.
BACKGROUND OF THE INVENTION
It is well known that Salmonella organisms have been associated with egg products. More recently, Salmonella enteritidis (SE) has been detected within shell eggs. Presently, the presence of Salmonella within the shell egg is a major concern. Some states have enacted legislation preventing the serving of unpasteurized egg products unless fully cooked. In fact, since as early as 1969, the USDA has overseen the processing of liquid egg removed from the shell to reduce the level of Salmonella contamination to acceptable levels. However, no commercially acceptable methods have been developed to combat Salmonella in shell eggs. Since shell eggs must be used in situations where a liquid egg product cannot, it is therefore desirable to develop a commercially acceptable process for the reduction of Salmonella within shell eggs to provide a safe and functionally acceptable shell egg to the consumer.
Thermal treatments of shell egg to prevent embryonic growth in fertile eggs, to reduce incidence of spoilage during long term storage, and maintain internal quality received considerable research attention from about 1943 to about 1953. This research resulted from the nature of the egg industry at that time in that most of the eggs were produced by small flocks and the majority of the eggs used by the food industry were collected as seasonal surpluses in the spring. As a result of the production practices the eggs were more likely to lose interior quality or become unfit for human consumption because of bacterial growth or embryonic development. Research into "thermostabilization" was directed at solving these problems, which were largely perceived as embryonic growth and the contamination of the egg from contaminants external to the shell. (See Egg Science, Chapter 4, 3d Ed., 1986).
U.S. Pat. No. 2,423,233 to Funk describes the thermostabilization of shell eggs. The '233 patent described a process of heating the shell egg to arrest embryonic development in the egg. As described in the '233 patent, when heating with water the preferred times and temperatures for the heat treatment were 138 degrees Fahrenheit for from five to ten minutes. However, the work of Dr. Funk was not concerned with the elimination of pathogenic organisms. In fact, the times and temperatures suggested by Dr. Funk for heating with water would not be sufficient to cause high enough levels of Salmonella enteritidis destruction to insure that a safe shell egg would result. Furthermore, because eggs available through modern production and distribution are fresher and have a lower pH they require a different thermal process than was used by Funk.
Accordingly, it is one object of the present invention to provide a safe shell egg product which is essentially free of Salmonella and more preferably free of Salmonella enteritidis.
It is another object of the present invention to provide a commercially acceptable process for reducing the levels of Salmonella enteritidis in shell eggs to acceptable levels.
It is still a further object of the present invention to provide a method of producing a Salmonella negative shell egg without requiring additional thermal treatments which could reduce the functionality of the shell egg.
SUMMARY OF THE INVENTION
The present invention provides methods for producing a pasteurized shell egg while retaining the normal appearance of the shell egg contents. The present invention, therefore, relates to a commercially viable method of producing a pasteurized shell egg. One particular embodiment of the present invention involves heating the shell egg in an aqueous solution of a predetermined temperature for a predetermined time. The heating at a predetermined time for a predetermined temperature provide to the albumen of the shell egg a total thermal treatment which can be described by an equivalent time and an equivalent temperature which define a point above the "whites" line of FIG. 1 but is insufficient to cause coagulation of either the albumen or the yolk of the shell egg.
In another aspect of the present invention the equivalent time and equivalent temperature define a point above the "yolk" line of FIG. 1, but again insufficient to cause coagulation of either the albumen or the yolk of the shell egg.
Another aspect of the present invention involves heating the shell egg in an aqueous solution of a predetermined temperature and maintaining the shell in the aqueous solution for a predetermined time, wherein the predetermined time and the predetermined temperature provide to the albumen of the shell egg a thermal treatment sufficient to cause a 9D reduction in S. enteritidis but insufficient to cause coagulation of the albumen or the yolk of the shell egg. A further aspect of this embodiment involves providing a thermal treatment sufficient to cause a 9D reduction in S. enteritidis from the yolk of the shell egg, but again insufficient to cause coagulation of the albumen or the yolk of the shell egg.
Yet another aspect of the present invention provides a method of producing a pasteurized shell egg by heating the shell egg in an aqueous solution of a predetermined temperature and maintaining the shell egg in the aqueous solution for a predetermined time, wherein the predetermined time and the predetermined temperature define a point above the Apparent F O line of FIG. 1, and wherein the predetermined time and the predetermined temperature are insufficient to cause coagulation of the albumen or the yolk of the shell egg. A further aspect of the present invention provides a thermal treatment wherein the predetermined time and the predetermined temperature define a point below the Expected Salmonella line of FIG. 1.
The present invention is also directed to a pasteurized shell egg, wherein the albumen of said shell egg has received a thermal treatment sufficient to cause a 9D reduction in Salmonella enteritidis but insufficient to cause significant coagulation. In another aspect of the thermally treated shell egg, the yolk of the shell egg receives a thermal treatment sufficient to cause a 9D reduction in Salmonella enteritidis but insufficient to cause coagulation.
The foregoing and other objects and aspects of the present invention are explained in greater detail in the specification below and the drawings herein, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of the apparent F O line superimposed on the thermal death time curves for Salmonella.
FIG. 2 is a graph of the thermal curve for a representative thermal treatment received by a shell egg according to the methods of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The term "shell egg" as used herein refers to poultry eggs, in the shell thereof with the shell essentially unbroken, wherein the egg yolk and the egg white are essentially liquid. Thus it is desired that shell eggs of the present invention contain yolks and whites which are substantially uncoagulated, in contrast to "soft boiled" (i.e., an egg placed in boiling water for three minutes) or "hard boiled" eggs (an egg cooked until both yolk and white are coagulated and solid). While any poultry egg may be used to carry out the present invention (including chicken, turkey, duck, goose, quail, and pheasant eggs), chicken eggs are particularly preferred.
One aspect of the present invention involves the heating of shell eggs in an aqueous solution of a specified temperature for a time sufficient to cause at least a reduction in Salmonella enteritidis (SE) of greater than 5 log cycles (5D). More preferably, the shell egg is placed in aqueous solution wherein the time in the solution and the temperature of the solution impart a treatment to the shell egg sufficient to cause a greater than 7D reduction in SE, and most preferably a reduction in SE of greater than 9D. It is preferred that the treatment of the shell egg be sufficient to cause the reduction in SE in the albumen of the shell egg and most preferable that the treatment be sufficient to cause the SE reduction in both the albumen and the yolk of the shell egg. These reductions in SE should be accomplished while retaining the functionality of the shell egg (e.g., maintaining the egg yolk and egg white in essentially liquid form).
For comparative purposes, it is noted that PCT Application No. WO 93/03622 to Cox describes a method of "hyperpasteurization" of shell eggs. As is described in FIG. 10 of Cox, relatively severe thermal treatments are expected to be required before Salmonella is destroyed. The data points shown in FIG. 10 of Cox may be used to construct a line which reflects what would be an expected Salmonella destruction line for shell eggs. This "Expected Salmonella" line is labelled as such and is shown in FIG. 1 herein ("Expected Salmonella") and has the equation log(t)=8.456-0.1183T, where t is time in minutes and T is temperature in °C. However, these more severe thermal treatments could cause loss in functionality to the shell egg (e.g., partial or complete coagulation of the egg yolk or egg white).
Eggs contain air cells, and the liquid component of eggs have gases such as oxygen and carbon dioxide therein. Cox describes altering the natural proportion of indigenous gases in the eggs being treated by means such as infusing oxygen into the egg or withdrawing gases from the egg. In carrying out the present invention, it is preferred that no such treatment steps be carried out which alter the natural indigenous gases present in the shell egg. Thus, the heating, holding, and cooling steps may be carried out at atmospheric pressure.
In the present invention, the thermal treatment employed preferably defines a point below the "Expected Salmonella" line of FIG. 1. Furthermore, the treatment of the shell egg should be insufficient to cause coagulation of either the albumen or the yolk of the shell egg. The methods of the present invention result in a SE negative shell egg having essentially the natural proportion of indigenous gases.
The method of the present invention involves placing shell eggs in an aqueous solution of a predetermined temperature and then maintaining the shell egg in the aqueous solution for a predetermined time sufficient to cause the reductions in SE described above. Preferably the volume of the aqueous solution is sufficiently great to minimize the reduction in temperature of the solution by the addition of the lower temperature shell eggs. Optionally, the eggs may be agitated or the aqueous solution may be circulated about the eggs to facilitate the transfer of heat from the solution to the eggs. Any suitable aqueous solution may be employed, including tap water and water with salt such as NaCl added.
After maintaining the eggs in the aqueous solution for the required time, the eggs may be removed and allowed to cool at room temperature. Cooling may be carried out by other means, such as by direct refrigeration, as long as the treatment received by the shell egg is sufficient to achieve the desired reduction in SE. The heat treatment received by the shell egg after removal from the aqueous solution may be considered in determining the total thermal treatment received by the shell egg, as will be apparent from the discussion below.
As will be appreciated by those skilled in the art, after thermally treating the shell eggs the shell eggs may be oiled or waxed in accordance with known techniques with a suitable edible oil such as mineral oil to improve the keeping quality of the eggs.
In selecting the heating temperatures and times to use in carrying out the present invention, any number of methods may be used, including the equivalent point method of thermal evaluation to determine the total thermal treatment at various locations of the shell egg, including the albumen and the yolk, inoculation studies may be conducted to determine the treatment conditions which yield the desired reduction in SE, or a F O value could be determined for the shell egg which results in the desired SE reduction. Furthermore, times and temperatures may be selected to give differing reductions in SE in different sections of the shell egg. For example, a time and temperature condition may be selected to provide a 9D reduction in SE in the albumen of the egg while imparting a 7D reduction in the yolk.
While lower temperatures may be used, in practice, aqueous solution temperatures of greater than about 134° F. (or about 56° C.) and less than about 140° F. (or about 60° C.) are preferred and, as discussed above, it is preferred that the temperature of the solution remain approximately constant for the time the shell eggs are heated. Times of from about 20 minutes to about 45 minutes or greater may be selected to achieve the desired reduction in Salmonella with shorter times being required for higher temperatures. The specific times and temperatures required may vary with size, age and pH of the shell egg and whether the shell egg has been oiled before or after thermal treatment.
If an equivalent point analysis of the thermal treatment received by a particular portion of the shell egg is utilized to determine the reduction of SE in the shell egg, then the resulting equivalent time and equivalent temperature should define a point above the desired Salmonella thermal death time curves such as those shown in FIG. 2 and Table 6 of the USDA Egg Pasteurization Manual, ARS 74-38, Agricultural Research Service, United States Department of Agriculture, Albany, Calif. (1969) which are labelled as such and reproduced in FIG. 1 herein and labelled as "Whites," "Yolk" and "Whole Egg".
If an F O analysis is employed in carrying out the present invention, then to assure a sufficient reduction in Salmonella such that no shell eggs test positive for Salmonella utilizing approved tests for Salmonella, such as those approved by the USDA for use in liquid egg processing and discussed in the Egg Pasteurization Manual, then actual time and temperature combinations which define points at or above both the Apparent F O line and the Salmonella thermal death time curve of FIG. 1 should be utilized. As will be understood by one of skill in the art, variations in shell egg physical characteristics, such as size, age, pH, etc., may cause the shell egg "Apparent F O " line of FIG. 1 to shift.
Shell eggs produced by the methods of the present invention preferably receive a thermal treatment such that the shell eggs have a shelf life of 12, 24 or 36 weeks or more under refrigerated conditions. The term "refrigerated" as used herein means the eggs are stored at a temperature of 4° C.
For storage and shipping, shell eggs of the present invention may be packaged in a suitable container, such as egg cartons or egg flats, constructed of materials such as cardboard or plastic polymer.
Shell eggs of the present invention may be used for any purpose for which raw eggs are currently used, including the table-side preparation of Caesar salads, the preparation of fried eggs, the preparation of hard-boiled eggs, the preparation of other egg dishes, baking, etc.
The present invention is explained in greater detail in the following Examples. These Examples are intended to be illustrative of the present invention, and are not to be taken as limiting thereof.
EXAMPLE 1
Salmonella Thermal Resistance
Two experiments were conducted to determine the thermal resistance of SE (Phage type 8) in artificially infected shell eggs and the resulting changes in interior quality due to elevated processing temperatures. During the first experiment fresh shell eggs weighing approximately 62 grams each were obtained from the University research unit. The eggs were dipped in an iodoform solution, excess solution was removed with a cheese cloth and permitted to air dry on sterile plastic egg flats. Each egg was inoculated with 10 6 viable cells from a 24 hour Trypticase soy broth culture of SE (phage type 8). The shell was perforated with a sterile blunt 18 gauge needle. A sterile blunt glass needle on a 10μ pipet was used to inject the culture near the yolk surface and the hole in the shell was then sealed with a small piece of aluminum foil and Super Glue. Groups of 36 eggs were subjected to temperatures of 22.2 (unheated control), 56, 56.75 and 57.5° C. Eggs within a temperature-group were subjected to a range of heating time periods ranging from 15 to 45 minutes. The study was replicated in time. Heating was carried out in a shaking water bath equipped with polyethylene egg flats perforated with numerous 1 cm holes to increase water circulation around the eggs.
Immediately following the heat treatment, each egg was broken separately and the albumen plus yolk was mixed for 30 seconds in a sterile Stomacher bag containing 200 ml of lactose broth using a Stomacher Lab - Blender 400 1 . The mixed egg content was incubated in a sterile glass container for 24 hours at 39° C. A representative culture was then transferred to selenite-cysteine broth and incubated for 24 hours at 39° C. The incubated culture was streaked on brilliant green agar plates and incubated for 24 hours at 39° C. The suspect colonies were transferred to TSI slants. The second experiment was conducted to evaluate the effect of heating, oiling and storage on interior egg quality. Four storage treatments of zero, one, two and four weeks were used, each with oiled and non-oiled eggs. The eggs were heated in a water bath at 56.75° C. for 36 minutes and 57.5° C. for 23 minutes. Eggs were oiled following heat treatment. Thirty eggs from the control and each treatment were stored at room temperature (22.2° C. and 7.2° C.).
A group of 14 eggs from each variable was used to determine pH, foam volume, whipping time, foam depth, foam stability, grade and a second group of 14 eggs was used to evaluate Haugh units.
EXAMPLE 2
Microbiology
Table 1 presents the results of the thermal treatments on the survival of S. enteritidis inoculated into shell eggs. As temperature increased, the time required to obtain Salmonella negative eggs decreased. At 56° C., exposure time required to obtain no positive eggs was greater than 41 minutes. At 56.75 and 57.5° C., exposure times greater than 28 and 23 minutes, respectively, were required to obtain eggs negative for Salmonella. Standard USDA tests for Salmonella were utilized.
TABLE 1______________________________________Number of samples positive after heating at 56, 56.75 and57.5° C. Temperature of WaterTime in Waterbath 56° C. 56.75° C. 57.5° C.min. •No. - No. + No. - No. + No. - No. +______________________________________15 12-416 12-1119 12-220 12-823 12-224 12-727 12-028 12-229 12-331 12-032 12-033 12-637 12-441 12-145 12-0______________________________________ •No. - No. + · Number of samples heated - number positive
EXAMPLE 3
Thermal Evaluation
Times at temperatures where none of the twelve inoculated eggs were positive, were used in a regression equation to determine the thermal death time curve (TDTC) presented in FIG. 1. As the "Apparent F O " line. The equation for the line is:
log (t)=-0.1216×T+8.4274
where t is the time in minutes and T is temperature in degrees Centigrade. The R 2 =0.86.
The above equation may be consider a workable approximation or an "Apparent F O " line for S. enteritidis in shell eggs. The temperature range and times used to obtain the data were selected with the intent of determining if commercially reasonable thermal treatments would have sufficient lethality for Salmonella sp. It is expected that increasing the number of samples and extending the temperature range would result in some changes in the slope of the line, especially at lower temperatures (Cotterill et al., 1973). Based on concerns for the interior quality and their use in cooking, the practical upper temperature range would probably be less than 60° C.. At temperatures in the range of 55 to 65° C., Cotterill et al. (1973) generally found linear TDTC for destruction of S. oranienburg. It is anticipated that the F O line for other forms of Salmonella in shell egg are also linear over that temperature range.
It is established that different strains of Salmonella, the type of egg product, and other environmental conditions will effect the thermal inactivation of Salmonella. Shah et al. (1991) presented D values for 17 strains of S. enteritidis in whole egg ranging from 13.7 to 31.3 seconds at 60° C. The average D was 19.2±5.4 sec. and was reported to be similar to previous data. Cotterill et al. (1973) and USDA (1969) provide data showing the influence of egg product type, pH, salt, and sugar on the thermal resistance of Salmonella sp. When evaluating the thermal resistance of Salmonella in intact shell eggs, the location of the bacteria within the egg becomes important. The thermal resistance of Salmonella in different egg products is as follows: plain yolk>whole egg or pH 7 egg white>pH 9 egg white (USDA, 1969). Therefore, increased thermal treatments would be required for plain yolk over whole egg or pH 7 egg white or pH 9 egg white.
In this study, the culture was placed in the egg white near the surface of the yolk. The consensus of those actively studying S. enteritidis infection of shell eggs is that the bacteria is found in the egg white of naturally infected eggs produced by infected hens (Gast and Beard, J. Food Prot., 55:152-156 (1991); Beard, Egg Industry, 92:3337 (1992)). The "Apparent F O " line was plotted in FIG. 1, a redrawing of FIG. 6 from the Egg Pasteurization Manual (USDA, 1969). This allows a visual evaluation of the thermal processes applied to intact shell eggs relative to accepted minimal pasteurization processes for liquid egg products.
When comparing the "Apparent F O " line and actual processes to the lines for pH 9 egg white and whole egg or pH 7 egg white, the shell egg processes seem to be more than adequate to achieve reductions of S. enteritidis sufficient for an accepted pasteurization process for protection of public health. The pH of the egg whites in this study ranged from 8.4 to 8.6 which is typical for shell eggs the age of those used in this study.
Although natural infections of the yolk are not expected at the time of ovulation, it is clear that under adverse handling conditions, S. enteritidis can be introduced into the egg and grow to very high numbers in the yolk (Hammack et al., Poultry Science, 72:373-377 (1993)). At 56° C. (134° F.), if the cells were in the yolk, the minimum holding time would be 36.42 minutes for an adequate pasteurization process. Since the apparent F O line crosses the USDA yolk pasteurization line at about 134° F., it is therefore preferred that thermal treatments for shell eggs at temperatures above 134° F. be selected.
In addition to the F O analysis described above, an equivalent point analysis of the time-temperature curve of the thermal treatment imparted to the shell egg may be utilized to determine the total thermal treatment imparted various locations in the shell egg. A temperature probe was inserted into shell eggs in the aqueous solution at various depths into the egg. Temperatures were taken in the albumen at the yolk/albumen interface and in the yolk. These temperatures were taken using a hypodermic needle probe model HYP4-16-1-1/2-100-EU-48-RP manufactured by BIOMEGA® of Stamford Conn. The probe was inserted into the egg through a cork which was glued to the egg and prevented water from entering the egg through the aperture created by the probe. A DAYTRONIC® System 10 data acquisition unit was connected through an RS-232 serial connection to a personal computer. Temperature measurements were taken every 5 seconds and recorded. A representative thermal curve for a thermal treatment to the shell eggs is shown in FIG. 2. To evaluate the equivalent point for the thermal curve shown in FIG. 2, the thermal reduction relationship (G Ea ) is calculated using the following equation: ##EQU1## where Ea is the activation energy (J/mol), R is the Universal Gas Constant (8.314 J/mol,K), T(t) is temperature as a function of time (°K.) and t final is the final processing time (s). This integration process is then repeated for a number of activation energies (Ea). Each G Ea value defines a line of equivalent thermal treatments for that particular activation energy (Ea). The intersection of the lines defined by the G Ea 's is the equivalent point of the thermal process. (Swartzel, 1986, J. Agric. Food Chem., 34:397).
Performing such an equivalent point analysis for the SE negative tests described above results in the following equivalent times and temperatures:
TABLE 2______________________________________Equivalent Point Data Albumen YolkBath Temp. Bath Time Eq. Temp. Eq. Time Eq. Temp. Eq. Time______________________________________56° C. 45 min. 54.45° C. 51.14 min. NA NA56.75° C. 32 min. 53.0° C. 39.58 min. 53.54° C. 38.41 min.57.5° C. 31 min. 54.86° C. 38.49 min. 54.33° C. 37.47 min.______________________________________
From these results an expected reduction in SE may be ascertained or additional thermal conditions predicted to achieve other reductions in SE.
Use of the time and temperature relationships discussed above should result in a shell egg which may be guaranteed to be Salmonella negative. As used herein Salmonella negative means a negative result indicating the absence of harmful Salmonella as determined by USDA approved methods of Salmonella testing. This insured Salmonella negative shell egg is referred to herein as a pasteurized shell egg.
EXAMPLE 4
Quality and Function
Quality and functional attributes of shell eggs heated at 56.75 and 57.5° C. with and without oiling are summarized in Table 2. The expected ability of oiling egg shells to maintain fresh egg pH and interior quality is evident. The egg white pH of the oiled eggs is clearly lower than for the unoiled eggs regardless of storage temperature. The thermal treatments did not seem to have an effect on egg white pH, but did seem to have an impact on interior quality as indicated by the Haugh unit values. For the non-thermally treated eggs, oiling held egg white pH and resulted in higher Haugh values at both storage temperatures. Oiling the thermally treated eggs appeared to help maintain interior quality if they were stored at room temperature (22.2° C.). The thermal treatments alone, provided good protection of interior quality. All thermally treated eggs regardless of oiling or storage temperature would be considered high A or AA quality grades. There seemed to be less correlation of egg white pH with interior quality than might have been expected. This is particularly so when comparing the egg white pH and Haugh units of oiled and unoiled eggs. That result suggests the thermal treatments are stabilizing interior quality independently of deterioration mechanisms related to change in egg white pH. Funk U.S. Pat. No. 2,423,233 (1947) claimed that heating shell eggs for 5 to 40 minutes at temperatures of 60 to 43.4° C., respectively, would maintain interior quality without impairing the whipping qualities. However, he did not define quality or whipping qualities.
TABLE 3__________________________________________________________________________Quality and Functional attributes of thermally treated shell eggswith and without oiling four weeks storage at 22.2 or 7.2° C. Egg White pH Haugh Unit Whip Volume.sup.a Whip Time.sup.b 22/2 C. 7.2 C. 22.2 C 7.2 C. 22.2 C. 7.2 C. 22.2 C. 7.2 C.__________________________________________________________________________No OilNo Heat 9.3 9.2 20 60 1,000 900 40 4556.75 C., 36 min. 9.2 8.9 78 82 550 650 220 11057.5 C., 23 min. 9.2 9.1 74 82 750 600 280 130OiledNo Heat 8.0 8.1 58 70 950 800 45 4556.75 C., 36 min. 7.9 8.2 80 80 550 650 190 20057.5 C., 23 min. 8.0 8.1 81 82 600 700 200 210__________________________________________________________________________ .sup.a Whip Volume in ml. .sup.b Whip Time in sec.
In this study, the whipping qualities as indicated by whip volume and whip time were adversely effected by the thermal treatments. This indicates that the thermal treatments were substantial and parallel damage that is expected when liquid egg white is pasteurized. Oiling or storage temperature did not seem to have an effect on function of the egg white.
Thermally treated eggs, when broken out onto a plate, appear quite similar to unheated eggs with the exception of some slight opaqueness of the albumen. The normal shape of the thick egg white is maintained and there appears to be the normal amount of outer thin albumen. The yolk membrane may exhibit some weakness. Although yolk indices were not determined, trained observers note some flattening of the yolk relative to unheated controls. The yolk membranes of heated shell eggs did not exhibit any additional fragility over the four week storage and seemed to withstand handling for Haugh unit determinations as expected for eggs of the same interior quality.
The foregoing examples are illustrative of the present invention, and are not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.
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The present invention relates to producing a safer shell egg through thermal treatment. The present invention provides methods of producing a shell egg wherein the albumen and the yolk of the shell egg receives a thermal treatment sufficient to pasteurize the shell egg and thereby combat the risk of salmonella. The present invention provides methods of providing thermal treatments to the shell egg through introduction of the shell egg into an aqueous solution of a predetermined temperature and maintaining the shell egg in the solution for a predetermined time sufficient to cause the required reduction in salmonella. The predetermined times and temperatures may be characterized by use of the equivalent point method of thermal evaluation, by use of the F O line for shell egg or by other methods of determining the reduction in salmonella.
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FIELD OF THE INVENTION
The instant invention relates to a system for controlling power windows of vehicles, and more particularly, the instant invention relates to a system for controlling power windows of vehicles wherein the vehicles include sets of front and rear windows in which each window of a set is individually controllable by switches on a module position proximate a driver's seat.
BACKGROUND OF THE INVENTION
Most four door vehicles with electrically operated power windows have a control module proximate the driver's seat. The module may be located between two front seats in a five passenger vehicle or on the driver's side door of a six passenger vehicle. In currently used configurations, the module includes a separate rocker or pushbutton switch for each window so that there are four rocker switches thereon. In addition to the rocker switches, the module usually includes a locking switch providing a feature for locking the passenger windows so that children in the back or right front seat cannot operate the windows without the driver unlocking the windows. This results in an array of five switches operable by the driver.
When a driver decides to open or close any window or to lock or unlock the rear windows, it is preferable that this task be as simple as possible.
In addition to the aforedescribed considerations, it is also desirable to decrease the expense of the various systems utilized in an automobile. If the expense of a particular system may be reduced while not compromising desirable qualities of the vehicle, then so much the better. If it is possible to reduce expense while enhancing other qualities of the vehicle, then the reduction in expense is certainly desirable. On way of reducing expense of a system is to reduce the number of components of the system. While this reduction in components may save only a modest amount per vehicle, if thousands of vehicles utilize the improvement, then the savings to the manufacturer and consumer can be significant, especially when combined with other cost reduction measures.
SUMMARY OF THE INVENTION
In view of the aforementioned considerations, it is an object of the instant invention to provide a new and improved system for controlling power windows wherein operation of the systems are simplified while decreasing the expense of the systems.
Upon further study of the specification and appended claims, further objects and advantages of this invention will become apparent to those skilled in the art.
In view of the aforementioned objects and other objects, the invention contemplates a power window system for a vehicle wherein the vehicle has sets of front and rear electrically operated windows in which each set includes a left and right hand window and wherein each window is raised and lowered by an electric motor and operating switch which is controlled by a motor switch which is ganged to a mode selector switch. The new and improved system utilizes a main module disposed proximate the driver's seat which has mounted thereon two operating switches for the front windows and mode selection switch connected to a power source of a power circuit, which mode selection switch is movable between first, second and third positions. When the mode selection switch is in the first position, all of the motors are connected through the motor switches to the power circuit so that the operating switch associated with each motor operates that motor. When the mode selection switch is in the second position, the operating switches for the front windows raise and lower the front windows; however, the motor switches controlling the rear windows are disabled so that the rear windows are not operable by either driver or passenger sitting in the front seats or those sitting in the back seats. When the mode selection switch is in the third position, the rear operating switches are disconnected and the front operating switches of the front windows are disconnected from the motors for the front windows and connected to the motors for the rear windows, whereby the operating switches normally associated with the front windows operate the rear windows.
In accordance with an additional embodiment of the invention, indicator lamps are provided which indicate which operating switches are active and what function they perform. At least one front indicator lamp is associated with the front windows and at least one primary rear indicator lamp and one secondary rear indicator lamp is associated with the rear windows. When the mode selection switch is in the first position, the front indicator lamp is illuminated and the primary rear indicator lamp is illuminated, indicating the operating switches on the console will raise and lower the front windows and the operating switches proximate the rear windows will raise and lower the rear windows. When the mode selection switch is in the second position, only the front indicator lamp is illuminated, indicating that the operating switch on the console will operate the front windows and the rear windows are inactive from all switches. When the mode selection switch is in the third position, the secondary left rear and right rear front indicator lamps are the only indicator lamps illuminated, indicating that only the front operating switches operate the rear windows.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is a perspective view of the cabin of a four door automobile having a window control module configured in accordance with the principles of the instant invention;
FIG. 2 is an enlarged planar view of the module of FIG. 1;
FIG. 3 is a schematic view showing a circuit diagram of a control circuit for operating electric window motors in accordance with the instant invention, the circuit being shown in a first mode;
FIG. 4 is a view similar to FIG. 3, but showing the circuit in a second mode;
FIG. 5 is a view similar to FIGS. 3 and 4, but showing the circuit in a third mode;
FIG. 6 is a truth table for the circuit when in the first mode of FIG. 3;
FIG. 7 is a truth table for the circuit when in the second mode of FIG. 4; and
FIG. 8 is a truth table for the circuit when in the third mode of FIG. 5.
DETAILED DESCRIPTION
Referring now to the drawings, there is shown a cabin 10 of an automobile body, which cabin includes left and right front doors 12 and 14, which front doors include left and right front power windows 16 and 18. The cabin 10 also includes left and right rear doors 20 and 22 which include left and right rear power windows 24 and 26. Proximate the left front door 12 and left front window 16, there is a driver's seat 28, while proximate the right front door 14 and right front window 18, there is a front passenger seat 30. In accordance with a preferred embodiment of the invention, disposed between the front seats 28 and 30, there is a console 32 which has a control module 34 thereon. A rear bench seat or a pair of bucket seats 35 extend between the rear doors 20 and 22. Mounted on the left rear door 20, there is a left control module 36 and on the right rear door 22, there is a right control module 38.
The modules 34, 36 and 38 each include switches for controlling the windows 16, 18, 24 and 26. In accordance with the principles of the instant invention, the console module 34 includes a left window operating switch 40 and a right window operating switch 42. The left window operating switch 40 has a first button 44 for raising the associated left front window 16 and a second button 46 for lowering the left, front window, while the right switch 42 has a first button 48 for raising the right front window 18 and a second button 50 for lowering the right front window. The rear module 36 has a left operating switch 52, while the right rear module 38 has a right operating switch 54. The left rear switch 52 has a first button 56 for raising the left rear window 24 and a second button 58 for lowering the left rear window, while the right switch 54 has a front button 60 for raising the right rear window 26 and a second button 62 for lowering the right rear window 26. While the term "button" is utilized, it is to be understood that the button pairs 44, 46; 48, 50; 56, 58; and 60, 62 may also be opposite ends of rocker switches.
In accordance with the principles of the instant invention, a mode selection switch 70 is mounted on the console module 34 and is slidable between first, second and third positions 72, 74 and 76, respectively, to select first, second and third operating modes. In the first operating mode, the switches 40 and 42 operate the left and right windows 16 and 18, respectively, the switch 52 on the rear door 20 operates the left rear window 24 and the switch 54 on the right rear door 22 operates the right rear window 26. When the mode selection switch 70 is in second position 74, the second mode occurs wherein the left and right rear switches 52 and 54 are disabled so that a person, such as a child sitting in the back seat 35, cannot operate the left and right rear windows 24 or 26. While the circuitry is in the second mode, the driver in the seat 28 or a person in the front seat 30 can operate the left and right front windows 16 and 18 by operating the left and right front switches 40 and 42, but cannot raise and lower the rear windows 24 and 26. When the mode selection switch 70 is placed in the third position 76, then the circuitry is in the third mode and the left and right front switches 40 and 42 operate the left and right rear windows 24 and 26, respectively, the left and right front windows 16 and 18, respectively, being disabled.
In order for the driver to know at a glance which of the switches 40, 42, 52 and 54 are active and what functions the switches perform, the console module 34 has sets of indicator lamps comprising a left front indicator lamp 80 and a right front indicator lamp 82, as well as a primary left rear window indicator lamp 84 and a primary right rear window indicator lamp 86, and a secondary left rear window indicator lamp 88 and a secondary right rear window indicator lamp 90. When the mode selection switch 70 is in the first position 72 and the circuitry is in the first mode, lamps 80, 82 are lit indicating that the front windows are operable by the switches 40 and 42 and the primary rear lamps 84 and 86 are lit indicating that the rear window switches 52 and 54 are active. When the switch 70 is in the second position 74 indicating that the circuitry is in the second mode, indicator lamps 80 and 82 are lit, showing that the switches 40 and 42 operate the front windows 16 and 18 while primary and secondary lamps 84, 86, 88 and 90 are extinguished indicating that the rear windows are not operable by any of the switches 40, 42, 52 or 54. When the mode selection switch 70 is in the third position 76 placing the circuitry in the third mode, only the secondary left rear window lamp 88 and secondary right rear window lamp 90 are lit, indicating that the operating switches 40 and 42 operate only the rear windows 24 and 26.
Referring now to FIGS. 3, 4 and 5, power and control circuitry 100 is shown in the first, second and third modes, respectively. The modes are selected by moving the mode selection switch 70 to the first, second and third positions, 72, 74 and 76. The windows 16, 18, 24 and 26 are driven by electric motors 102, 104, 106 and 108, respectively. The electric motors 102-108 are energized through motor switches 110, 112, 114 and 116, respectively. The motor switches each have terminals 1, C, 2 and 3, which correspond to terminals 1, C, 2 and 3 in the mode selection switch 70. The mode selection switch 70 and motor switches 110-116 are ganged by conventional means to operate simultaneously as a single switch assembly.
In the power and control circuit 100, the left side components comprised of the motors 102 and 106, motor switches 110 and 114 and the operating switches 40 and 52 are wired to the mode selection switch 70 in substantially identical fashion as the right side components, comprised of the motors 104 and 108, motor switches 112 and 116 and operating switches 42 and 54. In addition, the left front components comprising the motor 102, motor switch 110 and operating switch 40 are wired to the mode selection switch 70 in substantially an identical fashion as the right front components comprised of the motor 104, motor switch 112 and operating switch 42. It is likewise the case that the left rear motor 106, motor switch 114 and operating switch 52, are wired substantially identically to the right rear components comprising the motor 108, motor switch 116 and operating switch 54.
While the lamps are shown as pairs of lamps 80-82, 88-90 and 84-86, the instant invention contemplates using but a single lamp for each pair of doors to indicate which of the operating switches 40, 42; 52, 54 are active and the functions they perform.
Considering now the first mode, wherein the power and control circuitry 100 is configured as is shown in FIG. 3 and the truth table of FIG. 6 applies, it is seen that pairs of contacts 120 and 122 in the mode selection switch 70 and the motor switches 110, 112, 114 and 116 each connect terminals C to terminals 1. As a result, 12-volt direct current from a power source line 130 is available to operate all of the motors 102-108 upon operating any of the buttons 44, 46, 50, 48, 56, 58, 60 and 62, in their respective operating switches 40, 42, 52 and 54. In addition, the 12-volt direct current illuminates the left and right front lamps 80 and 82, as well as the primary left and right rear lamps 84 and 86.
Considering the current flow specifically, current on the power line 130 is connected via line 132 to a front bus 134 and to a rear bus 136 to provide current to terminals 2 in the operating switches 40, 42, 52 and 54. In addition, current is supplied by lines 140 and 142 to the terminals C in mode selection switch 70. When either of the buttons 44 or 46 in the operating switch 40 is pressed or either of the buttons 50 or 48 in the operating switch 42 is pressed, terminal a or terminal b in the operating switch 40 or 42 is connected to terminal 2. Actuating switches 44 or 46 causes current from terminal 2 of switch 40 to flow through motor switch 110 and motor 102 to ground 150. In the same fashion, actuating switches 48 or 50 causes current from terminal 2 of switch 42 to flow through motor switch 112 and motor 104 to ground 150 pushing button 46 lowers the left front window 16 and button 44 raises the left front window 16; pushing button 50 lowers the right front window 18 and button 48 raises the right front window.
With respect to raising and lowering the rear windows 24 and 26, when either the button 58 or button 56 in the left rear operating switch 52 is pressed or either the button 60 or 62 in the right rear window operating switch 54 is pressed, the motor terminals a or b are connected to hot terminal 2 so that current flows from the terminals 2 through the motors 106 or 108 to ground at 160. Consequently, any of the operating switches 40, 42, 52 or 54 may operate its respective window and, as is indicated in the truth table of FIG. 6, none of the motors or switches is disabled.
The left front lamp 80 and right front lamp 82, as well as the primary left rear lamp 84 and primary right rear lamp 86 are illuminated. This is because the current on line 142 flows through contact 120 and lines 160 and 162 to the lamps 84 and 86 and flows from line 140 through contact 122 and lines 164 and 166 to the lamps 80 and 82. The secondary rear lamps 88 and 90 are not illuminated because the line 168 is connected to open terminal 3 in the mode selection switch 70.
Referring now to FIG. 4 and the truth table of FIG. 7, it is seen now that the contacts 120 and 122 now span terminals C and 2 in mode selection switch 70 as well as in motor switches 110, 112, 114 and 116. When the contacts 120 and 122 are in the second mode (position 74 of FIG. 2), motors 102 and 104 are still connected to the source of current because jumpers 170 and 171 connect terminal 2 to terminal 1 in the left and right front motor switches 110 and 112. However, the left and right rear motor switches 114 and 116 are open because lines 176, 200, 177 and 202 are connected to terminal 1 of these switches and there is no jumper in the rear motor switches between terminal 1 and terminal 2. Accordingly, the left and right rear motors 106 and 108 for the left and right rear windows 24 and 26 are inoperable by the operating switches 52 and 54.
When the power and control circuitry 100 is in the second mode, the only lamps lit are the left front and right front lamps 80 and 82, respectively. This is because the line 164 is connected by contact 122 and jumper 180 to the power source line 130. The primary rear lamps 84 and 86 and the secondary left and right lamps 88 and 90 are not lit because the lines 160 and 168, respectively, are connected to open terminals 1 and 3 in the mode selection switch 70. As is seen in the truth table of FIG. 7, the left rear motor 106 and the right rear motor 108 are disabled because the switches 52 and 54 are disabled so that, in the second mode, only the front windows 16 and 18 are operable.
Referring now to FIG. 5 and to the truth table of FIG. 8, the power and control circuitry 100 is in the third mode where the left and right operating switches 40 and 42 operate only the rear windows 24 and 26, respectively. When in the third mode, the contacts 120 and 122 connect terminals C to terminals 3 in the mode selection switch 70 as well as the motor switches 110, 112, 114 and 116. When the contacts 120 and 122 connect terminals C to terminals 3 in motor operating switch 110, the motor operating switch 110 is disconnected from the left front motor 102 and is connected to the left rear motor 106. This is because the jumpers 170 and 171 are open at terminal 2, terminal 2 having been bypassed upon connecting terminal C to terminal 3. Terminal 3 is connected by lines 190 and 192 to the motor switch 114 on the left side of the Vehicle and by lines 194 and 196 to motor switch 116 on the right side of the vehicle. Lines 190, 192, 194 and 196 are connected to terminal 3 in motor switches 114 and 116 respectively so that contacts 120 and 122 take current from terminal 3 to terminal C and through the motors 106 or 108 upon pressing any one of the buttons 44, 46, 48 or 50 in the front operating switches 40 and 42. The rear operating switches 52 and 54 are disabled because lines 176 and 200 are connected to open terminals 1 in motor switch 114 and lines 177 and 202 are connected to open terminals 1 in rear operating switch 116. When the circuitry 100 is in the third mode, the only indicating lamps lit are the secondary left rear lamp 88 and the secondary right rear lamp 90. This is because the only line to indicating lamps energized is line 168 which is energized because contact 120 takes current from terminal C to terminal 3 and line 168. Left front lamp 80 and right front lamp 82 are not lit because line 164 is connected to open terminal 2 via jumper 180 connected to open terminal 1. The primary left rear lamp 84 and primary right rear lamp 86 are not lit because line 160 is connected to terminal 1 in mode selection switch 70 and terminal 1 is open.
As is seen in the third mode truth table of FIG. 8, the left and right front motors 102 and 104 are disabled and the left and right operating switches 25 and 54 are disabled so that the only operating switches and motors functioning are operating switches 40 and 42 and motors 106 and 108.
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
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A power window system for a four window vehicle has a console module positioned proximate the front seats of the vehicle, which console module has operating switches for the front windows and a mode selection switch thereon. The rear windows are normally operated by a pair of rear window operating switches disposed proximate the rear windows. When the mode selection switch is in the first position, front operating switches operate the front windows and the rear operating switches operate the rear windows. When the mode selection switch is in the second position, the rear operating switches are disabled and the front operating switches operate only the front windows. When the mode selection switch is in the third position, the front operating switches operate only the rear windows. An array of indicator lights is provided on the module to indicate which switches are active and what function they perform.
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BACKGROUND OF THE INVENTION
The invention concerns itself with a procedure for the rolling of metal strips in roll stands having pairs of combined rolls. The rolls of each pair are driven in opposite directions and at different circumferential speeds. The metal strip surrounds each roll over at least part of its circumference. The thickness of the metal strip is reduced by creation of various shear stresses in the various material cross-section zones which produces traverse sliding of the crystals.
In this procedure, "traverse-sliding" describes an action in which a form change takes place by which the crystals of the rolling stock are only deformed by thrust forces acting parallel to the slide area in the sliding direction, in the absence of which a twist of the slide area occurs. This "traverse-sliding" is the result of the different circumferential speeds of the roll pairs driven against each other in opposite directions, creating a shear stress, that is, an elastic stress which originates in outer forces acting in the cross-section area of the rolling stock.
With this type of rolling procedure, we are concerned with a traverse-sliding or a thrust-rolling procedure. The invention is also concerned with a rolling mill for execution of this procedure which can be designated in a manner corresponding to the previously-described definitions as a traverse-sliding, resp. thrust rolling mill. Rolling procedures and rolling mills of this type are described in German patent publications DE-OS No. 19 40 265 and DE-AS No. 21 33 058.
During a rolling operation with the conventional rolling mill, two material sliding zones are formed, namely a pre-stretch zone and a compression zone, on the contact areas between each roll and the rolling stock. The frictional forces within the zones are directed against each other. Such a slide zone formation between the rolling stock and the working rolls is prevented by the traverse-sliding, thrust rolling procedure. The advantage which results is that the rolling operation may be executed by preventing the high starting forces that are required in the common rolling procedures.
In the actual operating experience with the device made known through publication DE-OS No. 19 40 265, supra, of the newly-designed control of the thickness of the rolled stock have developed. To solve these problems, automatic thickness control has been tried. However, in every case shortcomings were experienced in efforts to achieve optimum rolling results, in spite of the technical expenditures. Therefore, it has been suggested in the publication DE-AS No. 21 33 058, supra, to create a rolling device of the same type which is distinguished by the fact that each of the combined working rolls is driven by its own motor. The roll, having a higher circumferential speed, is driven at a constant speed which is independent of the necessary load, whereas, with a roll having a lesser circumferential speed, the loading applied is selected in a reverse ratio. Consequently, therefore, the ratio of the circumferential speed of the combined working rolls corresponds to the ratio of the thickness of the rolling stock at its entrance and exit section.
This method eliminates the need for expensive and complicated automatic thickness controls. However, since each individual roller must be equipped with its own drive motor and its own variable gear, the expenditure is considerable. If a rolling device is equipped with a number of rolls, the installation of many motors and variable gear arrangements present spacing difficulties.
The principle object of the present invention is to eliminate the problems experienced with German patent publications DE-OS No. 19 40 265 and DE-AS No. 21 33 058, supra, by providing a procedure and a rolling mill of the same type in which a thickness control is completely eliminated from all traverse-sliding, or thrust rolling zones.
Another object of this invention is the provision of a method in which the final thickness control for the rolling stock is made by maintaining a pre-determined circumferential speed differential ratio between the individual rollers of the traverse-sliding or thrust-rolling stand by the control of the reduction per pass on a 4-high roll stand arranged ahead and/or after the traverse-sliding or thrust-rolling stand.
A further object of the present invention is the provision of apparatus for execution of the above rolling method.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.
SUMMARY OF THE INVENTION
According to this invention, a pre-determined circumferential speed differential ratio is maintained between the individual rolls of the traverse-sliding or thrust-rolling stand by mechanical and/or electrical control combinations of the individual roll pair drives. One form of the invention comprises a gear set which is activated by a common drive and is coupled with the rolls of a roll pair. So that different rolling programs may be executed, this invention also provides that the circumferential speed differential ratio between the individual rolls of the traverse sliding or thrust-rolling stand is pre-determined by a cascade connection arrangement of the gears.
It is a further importance in this invention that the roll gap control of the 4-high roll stand or stands be activated by measurements of thickness of the rolling stock on the inlet and outlet side of the traverse-sliding or tension-rolling stands. In addition, according to this invention, the RPM of the drive for the traverse-sliding or shear-rolling stand is maintained at a constant value and the reduction per pass and/or the run-off speed of the forwardly-located 4-high roll stand is controlled and/or pre-adjusted. A further extension of this invention consists of making the rolls of each pair of combined rolls of different diameters to pre-determine a certain circumferential speed differential ratio between the rolls in each pair, whereas all other circumferential speed differential ratios are derived from the cascade connections of the gear drives.
By means of the procedures carried out in accordance with this invention, the remarkable advantage is that the pre-determined reduction is achieved at the start of the rolling mill operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:
FIG. 1 is a schematic side view of a rolling mill embodying the principles of the present invention,
FIG. 2 is a view similar to FIG. 1, showing a first modification,
FIG. 3 is a view similar to FIG. 1, showing a third modification,
FIG. 4 is a schematic view of the 4-high stand viewed at a right angle to the plane IV--IV in FIG. 1,
FIG. 5 is a schematic view of the rolling mill in the area of the traverse-sliding or thrust-rolling stand viewed at a right angle to the plane in FIG. 1,
FIG. 6 is a schematic sectional view of the traverse-sliding or thrust-rolling stand taken along line VI--VI of FIG. 5, looking in the direction of the arrows,
FIG. 7 is a schematic side view on an enlarged scale of the 4-high roll stand shown in FIG. 1 having a controllable roll-gap, and
FIG. 8 is a schematic side view on an enlarged scale of the traverse-sliding or thrust-rolling stand, shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawing, there is shown a rolling mill for thickness reduction of metal strip material, having on the inlet side a drag reel 1 and on the exit side a pull reel 2. The rolling mills in the embodiments shown in FIGS. 1-3 consists of a so-called traverse-sliding, or thrust-rolling stand 3 and out at least 4-high one roll stand 4. In the rolling mill embodiment shown in FIG. 1, the 4-high roll stand 4 is arranged in front (on the inlet side) of the traverse-sliding, or thrust-rolling stand 3. In the embodiment shown in FIG. 2, the 4-high roll stand 4 is located at the exit side of the traverse-sliding or thrust-rolling stand 3.
In the embodiment shown in FIG. 3, a 4-high roll 4' is located in front of the inlet side an a further 4-high roll stand 4" is located at the outlet side of the traverse-sliding or thrust-rolling stand 3. In each of the three rolling mills shown in FIGS. 1-3, the metal strip material 5 is pulled from the roll-off or drag reel 1 by drive apparatus 6' and thereafter is introduced into the actual rolling mill by another drive apparatus 6".
In the rolling mill of FIG. 1, the metal strip material 5 passes first through the roll gap between the two driven work rolls 7 of the 4-high roll stand 4, in which the rolls 7 are adjusted by means of the two support rollers 8 to provide a controlled rolling pressure against the metal strip material 5. According to FIG. 1, thickness measuring devices 9 and 9' are provided on the inlet and outlet sides, respectively, of the 4-high roll stand 4. Measuring devices 9 and 9' continuously measure the thickness of the material which enters and exits the quarto-stand 4. The metal strip 5 is then introduced into the thrust-rolling stand 3 through a guide roll 10. From there, the metal strip 5 passes tangentially onto the lower roll 11' of a first combined roll pair 11, embraces a large part of its circumference and then enters the roll gap of the roll pair 11 tangentially to its upper roll 11" and contacts a large part of its circumference.
From the upper roll 11" of the first combined roll pair 11, the metal strip material 5 is transfered, for the purpose of stress relief, through a so-called S-roll pair 11'" in a manner similar to the passage through the roll pair 11 and from there onto the lower roll 12' of a second combined roll pair 12. The roll 12' as well as the roll 12" is surrounded in the same way as rollers 11' and 11" of the first combined roll pair 11 before it is exposed again for stress relief operation through an S-roll pair 12'". It is then introduced into a third combined roll pair 13 formed by a lower roll 13' and upper roll 13".
The metal strip material 5 passes from the circumference of the upper roll 13" of the third roll pair 13 for the purpose of further stress relief over a S-roll pair 13'" towards the outlet side of the traverse sliding, or thrust-rolling stand 3. From there is passes over a guide pulley and drive roll 14 as well as a guide pulley 15 towards a roll-up or pull-reel 2. At the back of the outlet side of the thrust-rolling stand 3 is located a thickness measuring device 16 which continuously measures the thickness of the finished rolled metal strip material 5 and transfers the measurement back to the 4-high roll stand 4 for a combined thickness control. Cutting shears 17 are arranged at the outlet side of the thrust-rolling stand 3 and severs the metal strip material 5 according to demand.
The rolling mill embodiment shown in FIG. 2, consists basically of the same components as the rolling mill described in connection with FIG. 1. One difference, however, is that the 4-high roll stand 4 is not arranged ahead of the inlet side of the thrust-rolling stand 3, but a the outlet side thereof. A further difference in the rolling mill according to FIG. 2, compared to the one shown in FIG. 1, is that the thickness measuring device 9 is arranged between the outlet side of the thrust-rolling stand 3 and the inlet side of the 4-high roll stand 4, and the thickness measuring device 16, as well as the cutting shears 17, is arranged at the outlet side of the 4-high roll stand 4.
The embodiment shown in FIG. 3 consists of yet another design. In this case, a 4-high roll stand 4' is arranged ahead of the inlet side of the thrust-rolling stand 3 and another 4-high roll stand 4" is arranged at the back, that is to say, at the outlet side of the thrust-rolling stand 3. Thickness measuring devices 9" and 9'" are arranged on the inlet and outlet sides, respectively, of the 4-high roll stand 4'. A thickness-measuring device 16 is also arranged at the outlet side of the 4-high roll stand 4".
An important criterion of the rolling mills built in accordance with FIGS. 1-3 is that the thrust-rolling stand 3 is operated completely without thickness control, that is to say, each of the three combined work roll pairs 11, 12, and 13 is operated with a constant reduction per pass, determined by the corresponding rolling program. The percentage-wise reduction per pass is not controlled by a corresponding adjustment of the roller gap, but is operated in such a way that the rolls 11", 12", and 13" of the combined operating roll pairs 11, 12, and 13 receive a correspondingly larger circumferential speed for the percentage-wise reduction per pass than the rolls 11', 12', and 13' of the individual roll pairs 11, 12, and 13. However, in cases where the thrust-rolling stand 3 (as shown in FIGS. 1-3), has several roll pairs 11, 12, and 13 arranged consecutively in the rolling direction, the circumferential speed of the roll 12' of the second roll pair 12 has the same circumferential speed as the roll 11" of the first roll pair 11. On the other hand, the circumferential speed of roll 13' of the third roll pair 13 has the same circumferential speed as the roll 12" of the second roll pair 12. This condition can be achieved by a mechanical and/or electrical combination of the individual roll pair drives.
In cases where each roll pair 11, 12, and 13 is equipped with its own drive, the combined adjustment of the circumferential speed for the rolls of the consecutively-arranged roll pairs 11, 12, and 13 is most simply accomplished by an electrical combination of the consecutive drives, whereby the electrical combination circuits which is used for the corresponding circumferential speed differential ratio between the two rolls of the previous roll pair should be considered. Electrical combination circuits are employed as a part of the process-calculator connected to the rolling mill. To guarantee a safe and problem-free operation of the thrust-rolling stand 3, all its roll pairs 11, 12, and 13 are driven by one common electrical motor 18, as can be seen from FIGS. 5 and 6. This drive motor 18 is connected directly with a shaft 19, which drive the roll 11' of the first roll set 11. On this shaft 19 and locked against turning are mounted three gear wheels 20', 20", and 20'" for selective engagement with a corresponding number of gear wheels 21', 22", and 21'", respectively, which are displacably-mounted on the shaft 22, which forms the drive for the upper roll 11" of the roll set 11. The wheels 20', 20", and 20'", therefore, form with the wheels 21', 21", and 21'" a variable shift arrangement, so that the circumferential speed of the upper roll 11 of roll set 11" may be varied relative to the circumferential speed of the lower roll 11' of the same roll set.
Tightly locked on the drive shaft for the upper roll 11" is a gear wheel 23, which is continuously engaged with a wheel 24 through an intermediate gear element (not shown), and is locked to a shaft 25 which drives the lower roll 12' of the second roll set 12. Also locked on the shaft 25 are three gear wheels 20', 20", and 20'" to which are arranged a corresponding number of displacement wheels 21', 21", and 21'" which are adjustable on the driving shaft for the roll 12" of the second roll set 12 in such a way that they are coupled for alternative selection with the wheels 20', 20", and 20'", respectively, of shaft 25 and therefore form a second variable gear shift mechanism.
Also mounted on the drive shaft for the roll 12", for rotation therewith, is an intermediate gear wheel (not shown) which is continuously engaged with a gear wheel 28 which is mounted for rotation with the drive shaft 29 for the roll 13' of the third roll set 13. Three gear wheels 20', 20" and 20'" are selectively engaged with displacable gear wheels 21', 21", and 21'", respectively, mounted on the drive shaft for the roll 13" of the third roll set 13, thereby forming a variable gear shift mechanism between the rolls 13' and 13".
The traverse-sliding or thrust-rolling stand 3, equipped with the drive arrangement shown in FIGS. 5 and 6, may be operated by only one drive motor 18 and a number of different rolling programs with variable reduction per pass and without any thickness control within the thrust-rolling stand 3. The extent of the corresponding reduction per pass within the roll gaps of the combined working roll pairs 11, 12, and 13 is activated exclusively by the individual variable gear shift mechanism by variations of the circumferential speeds of the upper rolls 11", 12", and 13" relative to the lower rolls 11', 12', and 13'. The thickness tolerance will be automatically reduced percentage-wise for the corresponding percentage-wise reduction per pass.
When a separate drive motor 18 is used for each of the three roll pairs 11, 12, and 13, as mentioned above, the corresponding gear members which mechanically connect the roll sets are eliminated. In place of these mechanical gear members, electrical combination circuits, as mentioned above, are arranged which connect the different drives 18 with each other. The control of the final thickness for the metal strip material 5 is brought about in every case for all rolling mills shown in FIGS. 1-3 outside the thrust-rolling stand 3, and with the help of the pre- and/or post-arranged 4-high roll stands 4, 4', and 4".
To initiate the control of the final thickness of the metal strip material 5, the thickness measurement is made on the inlet side and the outlet side of the 4-high roll stands 4. In the embodiments shown in FIG. 1, the inlet side measurement is made by the thickness measuring devices 9 and 9' and thickness measurement on the outlet side of the thrust-rolling stand 3 is made by the thickness measuring device 16. The thickness measuring device 16 signals any deviation from a pre-determined end-thickness to the process calculator or the like in which the determined intermediate thicknesses are stored which are to be created on the metal strip material 5 within the thrust-rolling stand 3. Depending on the amount of this deviation, the process calculator then controls the adjusting device 31 for the support rolls 8 of the 4-high roll stand 4, which brings about a corresponding roll gap change between the work rolls 7.
Under exceptional circumstances, it would be possible to change, by means of an infinitely variable speed drive, the differential ratio of the circumferential speed between the roll 13' and 13" of the last roll pair 13 within the thrust-rolling stand, by a differential gear by means of the process calculator to achieve the pre-determined end-thickness of the metal strip material 5.
Both work rolls 7 of the 4-high roll stand 4 are driven by a so-called twin-drive or as shown in FIG. 4, by a common drive motor 32 and a pinion roll stand 33. The thickness-measuring device 9 determines the change in thickness of the entering metal strip material 5 and so serves as a pre-control. The thickness-measuring device 9' determines the thickness change of the metal strip material 5 resulting from the roll gap change in the 4-high roll stand 4 before it enters the thrust-rolling stand and activates the post-control of the thickness. It thereby serves as a monitor for AGC-control (automatic gage control) within the roll gap of the 4-high roll stand 4. A correction of the drive speed for the motor 32 is achieved through a stress-measuring device at the guide pulley 10 between the 4-high roll stand 4 and the thrust-rolling stand 3, so that the circumferential speeds of the roll sets 11, 12, and 13 of the thrust-rolling stand 3 can be held constant to their pre-determined circumferential speed differential ratios.
The method of operation of the rolling mill shown in FIG. 2 corresponds generally with the operation of the one shown in FIG. 1. One difference, however, is that, in order to control the thickness of the metal strip material 5, the 4-high roll stand 4 is arranged at the rear of the outlet side of the thrust-rolling stand 3. The thickness-measuring device 16 passes a signal of any difference from the pre-determined wall thickness to a process calculator which releases a roll gap correction to the work rolls 7 of the 4-high roll stand 4 by a corresponding operation of the adjusting device 31. Based on this process calculator, the thickness-measuring device 9 also operates ahead of the inlet side of the 4-high roll stand 4, wherein thickness changes in the metal strip material 5 coming from the thrust-rolling stand 3 are determined to release a proportionate roll gap change. In this case, the process calculator does not have to show program components which are dependent on the adjusted intermediate thickness within thrust-rolling stand 3.
The embodiment shown in FIG. 3 of the drawing represents an especially advantageous operating rolling mill, but which requires a higher expenditure. It provides especially good operating results and, therefore, can be used for the rolling of quality metal strip material 5. The good operating result is achieved by the fact that a thickness control provided on the metal strip material 5 by the 4-high roll stand 4' is made before it enters the traverse-sliding or thrust-rolling stand 3, which control may be initiated by the thickness-measuring devices 9" and 9'" through the process calculator. After the exit of the metal strip material 5 from the thrust-rolling stand 3 and the 4-high roll stand 4", the thickness-measuring device 16 determines the thickness present in the strip. The measuring device 16 makes after-corrections through the process calculator to the pre-arranged 4-high roll stand 4' and introduces, in case it is necessary, a required after-control to the 4-high roll stand 4" to achieve the final thickness of the metal strip material 5.
FIG. 7 shows, in enlarged scale, the 4-high roll stand 4 used according to FIG. 1. FIG. 8 shows, in enlarged scale, the thrust-rolling stand 3 used according to FIG. 1. On the left side of FIG. 7 is indicated the exit thickness of the metal strip material 5. The right side of FIG. 7 shows, in solid lines, the rated size of the metal strip material 5 which has to be present when the indicated end-thickness of this metal strip material 5 is exactly kept (also shown on the right hand side of FIG. 8 by solid lines).
Indicated by dash-point lines in the FIGS. 7 and 8, are negative deviations from the rate sizes of the material thickness, which deviations must be corrected by a positive after-control of the roll gap within the 4-high stand 4 according to FIG. 7. The dash-lines, however, indicate positive deviations from the rated sizes and for its elimination and a roll gap after-control within the 4-high stand 4 is required in the negative sense. FIG. 8 indicates, in addition, the consecutive roll pairs 11, 12, and 13 of the thrust-rolling stand 3 with the S-roll pairs 11'", 12'", and 13'" arranged after them, which introduce during a rolling operation, a stress relief within the metal strip material 5.
The following table shows eight different rolling programs which, for example, may be executed with the rolling mill according to FIG. 1. It is assumed that the 4-high roll stand 4 is laid out for a control range which permits a thickness reduction between 10 and 40 percent. It is also assumed that the circumferential speed-differential ratio for the roll pair 11 of the thrust-rolling stand 3 may be pre-adjusted over the added variable speed control gear for thickness reduction of 10 percent, 30 percent, and 50 percent. The second roll pair 12 of the roll stand 3 permits 10, 20, and 40 percent thickness reductions over its variable speed control gear. For the roll pair 13 it is possible to achieve a thickness reduction of 10 and 30 percent through its variable speed control gear.
In column 1 of the table the different rolling programs are determined by identification numbers. Column 2 shows which strip thickness reduction is achieved. Column 3 shows the effective strip thickness reduction for which the 4-high stand 4 is selectively adjusted before the start of the corresponding rolling operation. Column 4 shows, percentage-wise, the selected reduction steps of the three roll pairs 11, 12, and 13 for the operation of the thrust-rolling stand 3. Finally, column 5 of the table shows the individual total thickness reduction in percent for the individual rolling program.
TABLE______________________________________1 2 3 4 5______________________________________ Thrust-rolling stand (3)Roll- Quarto- Roll- Roll- Roll-ing Strip Thick- Rolling ing ing ing TotalOper- ness Reduc- Stand Pair Pair Pair Reduc-ation tion (4) (11) (12) (13) tion______________________________________1 5.0-3.0 4.12 10% 10% 10% 40%2 4.0-2.0 3.51 30% 10% 10% 50%3 2.5-1.0 2.0 30% 20% 10% 60%4 2.0-0.6 1.58 30% 40% 10% 70%5 2.0-0.45 1.66 50% 40% 10% 77,5%6 2.0-0.36 1.70 50% 40% 30% 82%7 2.0-0.30 1.44 50% 40% 30% 85%8 2.0-0.26 1.25 50% 40% 30% 87%______________________________________
From this table it is clear that for each of the eight listed rolling operations, a wall thickness control has to occur exclusively within the area of the 4-high roll stand 4 to achieve the desired final thickness of the strip material 5. This is due to the fact that the 3 roll pairs 11, 12, and 13 of the traverse-sliding or thrust-rolling stand 3 operate in every case through the variable speed gears, with fixed pre-adjusted circumferential speed-differential ratios, which naturally are selected in dependence on the outlet speed of the 4-high roll stand through the process calculator.
It may be mentioned here that certain circumferential speed-differential ratios between the two rolls of each roll pair 11, 12, and 13 of the traverse-sliding or thrust rolling stand 3 may be achieved by the use of different rolling barrel diameters if it is required to reduce the design expenditures for the individual variable speed gears. This offers the possibility of achieving a circumferential speed-differential ratio of 10% for each of the 3 roll pairs 11, 12, and 13 of the traverse-sliding or thrust rolling stand 3.
If, for example, the lower rolls 11', 12', and 13' of the three roll pairs 11, 12, 13, respectively, have a barrel diameter of 400 mm, then the complimenting upper rolls 11", 12", and 13", respectively, have to be designed for a barrel diameter of 440 mm to achieve the corresponding revolutions per minute of the circumferential speed-differential ratio of 10%.
In the above design, the first gears 20', 21' may be eliminated for each of the three variable speed gears. During lay-out of the two remaining gears, the fixed circumferential speed-differential ratio has to be correspondingly considered.
So that a continuous rolling of strip material may be executed, an additional reel 1' is added to the initial reel 1 shown in FIGS. 1 to 3, so that the strip material 5' may be pulled off over a drive apparatus 6'".
The strip starting end of the strip material 5' may be welded, with the help of a welding device 34, to the end of the strip material 5, for example, during a short interruption of the rolling operation of the whole rolling mill. Since no thickness control is made on thrust rolling stand 3, the rigid drive permits, after execution of the welding procedure, a start-up from zero speed with constant thickness reduction.
It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.
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A method of and apparatus for rolling metal strips in a rolling mill having a 4-high roll stand and a tension roll stand comprising a plurality of pairs of combined rollers. The method comprises advancing the metal strips through the 4-high roll stand and tension roll stand, so that the strip extends between the roller of each pair of combined rollers and is partially wrapped around each of the rollers. The rollers of each pair are rotated in opposite directions at a pre-determined circumferential differential speed ratio.
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TECHNICAL FIELD
The present invention relates to a method and a receiver for receiving signals in a mobile station. In particular the present invention relates to a method and a receiver for receiving a VAMOS transmitted signal.
BACKGROUND
The rapid growth of the subscriber base in Global System for Mobile communication (GSM) has increased the need for increased voice capacity. Therefore mobile network operators and telecom equipment manufacturers have agreed to open a new Release 9 work item in the Third Generation partnership Project (3GPP) standardization. The work item has been named “Voice services over Adaptive Multi-user channels on One Slot” (VAMOS). It is described in 3GPP TSG GERAN GP-081949 “New WID: Voice services over Adaptive Multi-user Orthogonal Sub channels”.
The VAMOS air interface is based upon the concept of Adaptive Symbol Constellation, see 3GPP TSG GERAN GP-081633 Draft TR on Circuit Switched Voice Capacity Evolution for GERAN. Two different mobile station supports are envisaged for VAMOS aware mobile stations:
1. VAMOS aware mobile stations with legacy architecture: These mobile stations are supporting Downlink Advanced Receiver Performance (DARP) phase 1 capability and can operate the new designed training sequences. Radio performance requirements for these mobile stations will be specified with higher priority.
2. VAMOS aware mobiles with advanced receiver architectures.
The new modulation introduced in 3GPP TSG GERAN GP-081949 “New WID: Voice services over Adaptive Multi-user Orthogonal Sub channels” employs a time varying signal constellation called adaptive alpha-QPSK. This quaternary constellation is parameterized by a real-valued parameter. This real-valued parameter defines the shape of the signal constellation, and it can change from burst to burst. The real and imaginary parts of the baseband signal are assigned to two users and constitute two sub-channels.
Mobile station architectures based on the DARP phase 1 capability employ so-called Single Antenna Interference Cancellation (SAIC). SAIC mobile stations were designed to demodulate a Gaussian Minimum Shift Keying (GMSK) carrier and suppress GMSK-modulated interference. These mobile stations are typically designed to suppress one dominant interferer. They can be used to suppress the second sub-channel in an alpha-QPSK modulated signal and therefore can be used as receivers for the VAMOS technique.
However, the SAIC methodology does not exploit the fact that when alpha-QPSK modulation is used, the second sub-channel has a very particular structure for example a constant 90 degree phase shift with respect to the first sub-channel. Moreover, a SAIC receiver will experience the second sub-channel as the dominant interference and it will lose effectiveness suppressing additional external interferers.
VAMOS aware mobile stations that exploit knowledge of the two training sequences for the two users and of the shape signal constellation have been proposed, see the international patent application No. PCT/SE2008/051255. When an ordinary QPSK demodulator or a proper modification of a QPSK modulator to deal with alpha-QPSK is used, then joint detection is performed. This type of receiver offers optimal performance whenever the signal is corrupted by Gaussian white noise only. But such a receiver is unable to effectively suppress any external interference.
Hence, there exists a need for an improved receiver. In particular there is a need for a receiver adapted to receive a VAMOS transmitted signal.
SUMMARY
It is an object of the present invention to overcome or at least reduce some of the problems associated with existing receivers.
It is another object to provide an improved receiver for a VAMOS aware mobile station receiver with one antenna branch. Such receiver falls within the category 2 of VAMOS mobile station with advanced receiver architecture described above.
At least one of the above objects is obtained by the method and the receiver as set out in the appended claims. Thus, in accordance with the present invention a receiver, in particular a VAMOS receiver is provided, which receiver is adapted to split the complex-valued baseband signal into its real and imaginary parts, thus creating a two branch system. The two branch system is modeled as a Multiple Input Multiple Output, MIMO, system with two real-valued inputs and two real-valued outputs. The receiver is further adapted to use correlations of the noise, both in time and between branches of a channel to suppress the interference for multi-users in the same channel.
In accordance with one embodiment the receiver is adapted to take into account the known symmetries present in a symbol constellation when more than one user exist in the same channel. This is for example the case in adaptive symbol constellation such as an adaptive alpha-QPSK constellation. Using the receiver in accordance with the above can provide the same performance as a joint detection receiver in the presence of Gaussian white noise, while giving better interference suppression than either SAIC or joint detection in the presence of GMSK modulated interference.
The invention also extends to a method for receiving a signal in accordance with the above.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described in more detail by way of non-limiting examples and with reference to the accompanying drawings, in which:
FIG. 1 is a view illustrating an alpha QPSK modulator,
FIG. 2 is a view illustrating a variant of the alpha QPSK modulator,
FIG. 3 is a flowchart illustrating procedural steps performed during Multi-user detection with single antenna interference cancellation, and
FIG. 4 is a view of a receiver adapted to use reduced state multi-user detection with single antenna interference cancellation.
DETAILED DESCRIPTION
In FIG. 1 the modulator described in 3GPP TSG GERAN GP-081633 Draft TR on Circuit Switched Voice Capacity Evolution for GERAN is shown. In FIG. 2 the modulator described in 3GPP TSG GERAN GP-090113 VAMOS Physical Layer Adaptation Schemes is shown. It is a slight generalization of the modulator shown in FIG. 1 . The difference between the modulators depicted in FIG. 1 and FIG. 2 is that in FIG. 2 two different pulse shaping filters are used.
The parameter α defines the shape of the constellation and the signal is rotated by an angle θ. Without loss of generality, assume that the receiver must decode the signal intended for user 1. The baseband received signal (r n ) sampled at the symbol rate can be written in terms of an L-tap complex-valued channel (h k ) k=0 L-1 , the desired user binary symbols (a n ) n=0 N , the binary symbols for user 2, (b n ) n=0 N , the synchronization position n0 and noise plus interference (w n ):
r
n
+
n
0
=
α
2
∑
k
=
0
L
-
1
h
k
ⅇ
(
n
-
k
)
j
θ
a
n
-
k
+
j
2
-
α
2
2
∑
k
=
0
L
-
1
h
k
ⅇ
(
n
-
k
)
j
θ
b
n
-
k
+
w
n
(
1
)
The baseband model (1) gives a mathematical representation of a received signal transmitted by the modulator shown in FIG. 1 .
Equivalently, after de-rotation by θ,
r n + n 0 ′ = α 2 ∑ k = 0 L - 1 h k ′ a n - k + j 2 - α 2 2 ∑ k = 0 L - 1 h k ′ b n - k + w n ′ ( 2 )
where the prime indicates that the signal and the channel taps have been de-rotated.
Below some known technologies, namely SAIC and joint detection are described. A SAIC receiver uses a signal model of the form
r n + n 0 ′ = α 2 ∑ k = 0 L - 1 h k ′ a n - k + z n , ( 3 )
where (z n ) models the noise plus interference. By Comparing equation (2) and equation (3), it can be noted that the knowledge of the structure of the signal intended for user 2 is not used. That is, the explicit form of the second term on the right hand side of (2) is not used by a SAIC receiver.
On the other hand, a joint detection receiver uses the model in accordance with equation (2) but it is unable to exploit any correlations between the real and imaginary parts of (w n ′). Thus, such a receiver is optimal only if (w n ′) is white, circularly symmetric complex Gaussian noise. It can be noted that GMSK interference is not a circularly symmetric, white Gaussian process.
Taking real and imaginary parts in Equation (2), and using the fact that the symbols (a n ) n=0 N and (b n ) n=0 N are real-valued, the following pair of equations is obtained.
ℛ
e
(
r
n
+
n
0
′
)
=
α
2
∑
k
=
0
L
-
1
ℛ
e
(
h
k
′
)
a
n
-
k
-
2
-
α
2
2
∑
k
=
0
L
-
1
??
m
(
h
k
′
)
b
n
-
k
+
ℛ
e
(
w
n
′
)
??
m
(
r
n
+
n
0
′
)
=
α
2
∑
k
=
0
L
-
1
??
m
(
h
k
′
)
a
n
-
k
+
2
-
α
2
2
∑
k
=
0
L
-
1
ℛ
e
(
h
k
′
)
b
n
-
k
+
??
m
(
w
n
′
)
(
4
)
By defining
r → n = [ ℛ e ( r n + n 0 ′ ) ?? m ( r n + n 0 ′ ) ] ,
H k = [ α 2 ℛ e ( h k ′ ) - 2 - α 2 2 ?? m ( h k ′ ) α 2 ?? m ( h k ′ ) 2 - α 2 2 ℛ e ( h k ′ ) ] , w → n = [ ℛ e ( w n ′ ) ?? m ( w n ′ ) ]
It is possible to re-write equation (4) into a matrix form:
r
→
n
=
∑
k
=
0
L
-
1
H
k
[
a
n
-
k
b
n
-
k
]
+
w
→
n
(
5
)
This is a 2×2 Multiple Input Multiple Output (MIMO) real-valued system, with spatially and temporally correlated noise ({right arrow over (w)} n ). In order to obtain optimum performance both sequences of symbols (a n ) n=0 N and (b n ) n=0 N must be simultaneously demodulated. Known interference suppression and symbol detection algorithms can be applied to equation (5). For example the methodology for synchronization and channel estimation of time dispersive MIMO systems can be applied to the model (5), see e.g. the international patent application No. PCT/IB2005/002149. Another example is the MLSE with spatio-temporal interference cancellation described in: “MLSE and Spatio-Temporal Interference Rejection Combining With Antenna Arrays, D. Asztely and B. Ottersten, Ninth European Signal Processing Conference Eusipco-98”, which can also be applied to equation (5). Only one of the two branches in (5) is necessary in order to perform joint demodulation of both sequences of symbols. The other branch provides the diversity necessary for spatial or spatio-temporal interference suppression.
In accordance with one embodiment the following example of interference cancellation based on the model equation (5) is given. In the example given the Interference Rejection Combining methodology described in “Interference cancellation using antenna diversity for EDGE-enhanced data rates in GSM and TDMA/136, Bladsjo, D.; Furuskar, A.; Javerbring, S.; Larsson, E. Vehicular Technology Conference, 1999. VTC 1999—Fall. IEEE VTS 50th Volume 4, Issue, 1999 Page(s):1956-1960 vol. 4” is as follows. Let Q=E└{right arrow over (w)} n ·{right arrow over (w)} n T ┘ be the 2×2 spatial covariance matrix of the noise. First, a Cholesky (in general any square-root) factorization Q −1 =D T D is performed. Decorrelation of the 2 branches in equation (5) is achieved by multiplying both sides of equation (5) by D.
D
·
r
→
n
=
∑
k
=
0
L
-
1
D
·
H
k
[
a
n
-
k
b
n
-
k
]
+
D
·
w
→
n
.
(
6
)
This simple linear transformation performs interference suppression. Writing {right arrow over (y)} n =D·{right arrow over (r)} n , G k =D·H k , {right arrow over (e)}=D·{right arrow over (w)} n equation (6) becomes:
y → n = ∑ k = 0 L - 1 G k [ a n - k b n - k ] + e → n , ( 7 )
where ({right arrow over (e)} n ) is a two dimensional white noise. The model in accordance with equation (7) can now be considered as a time dispersive 2×2 MIMO system with additive Gaussian white noise. Optimum detectors are known for these signals. Better performance can be obtained if ({right arrow over (w)} n ) in equation (5) is modeled as a Vector Autoregressive process as in “MLSE and Spatio-Temporal Interference Rejection Combining With Antenna Arrays, D. Asztely and B. Ottersten, Ninth European Signal Processing Conference Eusipco-98, or if the modeling methodology described in PCT/IB2005/002149 is used.
The methodology for multi-user detection and interference suppression with a single antenna is summarized in the flowchart in FIG. 3 .
Thus, first in a step 301 the received signal is modeled as a two-user, one dimensional, complex-valued alpha-QPSK modulated signal. Next, in a step 303 , the received signal is split into real and imaginary parts. Next, in a step 305 a model using symmetries in channel impulse response to obtain a real-valued 2×2 MIMO system with colored noise is generated. Then, in a step 307 a spatio-temporal interference rejection combining to suppress external interference is applied. Then, in a step 309 joint demodulation of two users in 2×2 MIMO system is performed.
More generally, the methodology described in equations (4)-(7) can be applied to baseband models of the form
r n + n 0 = α 2 ∑ k = 0 L - 1 h k ⅇ ( n - k ) j θ a n - k + j 2 - α 2 2 ∑ k = 0 L - 1 g k ⅇ ( n - k ) j θ b n - k + w n , ( 8 )
where (h k ) k=0 L and (g k ) k=0 L model the channels for users 1 and 2 respectively, and the symbols (a n ) n=0 N and (b n ) n=0 N are real-valued. No particular relationships between the channels for the two users are assumed and the two user signals are pulse amplitude modulated (PAM).
The baseband model (8) gives a mathematical representation of a received signal transmitted by the modulator shown in FIG. 2 .
After de-rotation by θ, (8) becomes
r n + n 0 ′ = α 2 ∑ k = 0 L - 1 h k ′ a n - k + j 2 - α 2 2 ∑ k = 0 K - 1 g k ′ b n - k + w n ′ , ( 9 )
where the prime indicates that the signal and the channel taps have been de-rotated.
Taking real and imaginary parts in equation (9), and using the fact that the symbols (a) n=0 N and (b n ) n=0 N are real-valued, the following pair of equations are obtained
ℛ e ( r n + n 0 ′ ) = α 2 ∑ k = 0 L - 1 ℛ e ( h k ′ ) a n - k - 2 - α 2 2 ∑ k = 0 K - 1 ?? m ( g k ′ ) b n - k + ℛ e ( w n ′ ) ,
?? m ( r n + n 0 ′ ) = α 2 ∑ k = 0 L - 1 ?? m ( h k ′ ) a n - k + 2 - α 2 2 ∑ k = 0 K - 1 ℛ e ( g k ′ ) b n - k + ?? m ( w n ′ ) . ( 10 )
Define
r → n = [ ℛ e ( r n + n 0 ′ ) ?? m ( r n + n 0 ′ ) ] ,
H k = [ α 2 ℛ e ( h k ′ ) - 2 - α 2 2 ?? m ( g k ′ ) α 2 ?? m ( h k ′ ) 2 - α 2 2 ℛ e ( g k ′ ) ] , w → n = [ ℛ e ( w n ′ ) ?? m ( w n ′ ) ] .
Then (10) can be recast in matrix form
r
→
n
=
∑
k
=
0
L
H
k
[
a
n
-
k
b
n
-
k
]
+
w
→
n
.
(
11
)
This is a 2×2 MIMO real-valued system, with spatially and temporally correlated noise ({right arrow over (w)} n ). The MIMO model has the same functional form as the model described in equation (5). Thus, interference suppression together with joint detection may also be applied to this model in exactly the same way, for example applying spatial decorrelation as in equations (6) and (7), or using more advanced spatio-temporal decorrelation methods.
From equation (5) it is seen that the trellis for the (soft or hard) demodulation of the two streams of binary user symbols (a n ) n=0 N and (b n ) n=0 N has 4 L transitions. A typical channel length in GSM is L=5. This yields 1024 transitions. The complexity of the demodulator can be greatly reduced by re-shaping or shortening the channel impulse response. Since equation (5) is a 2×2 MIMO system, this procedure can be quite complex and difficult.
However, the special structure of the channel can be used as follows. A single-input-single-output all-pass filter that transforms the complex channel (h k ′) k=0 L-1 into a minimum phase channel is calculated. Such filters are widely used in GSM/EDGE for the demodulation of 8PSK modulated signals, see “Equalization Concepts for EDGE, W. Gerstacker and R. Schober, IEEE Transactions on Wireless Communications Vol 1 No 1, January 2002. These are scalar filters and there are efficient algorithms to calculate them. Moreover, since the filter is an all-pass filter it does not alter the color of the noise, nor does the all-pass filter enhance or suppress the noise. Applying the all-pass filter to both sides of equation (2) a model of the form:
r ~ n + n 0 ′ = α 2 ∑ k = 0 L - 1 h ~ k ′ a n - k + j 2 - α 2 2 ∑ k = 0 L - 1 h ~ k ′ b n - k + w ~ n . ( 11 )
is obtained.
This model has the same form as equation (2). The carrier to interference plus noise is the same as in equation (2), but the channel ({tilde over (h)} k ′) k=0 L-1 is minimum phase. This means that for every
M ≥ 0 , ∑ k = 0 M h ~ k ′ 2 ≥ ∑ k = 0 M h k ′ 2 .
In other words, the energy is concentrated in the first taps. The model of equation (11) can be transformed into a model of the foil of equation (5) by following exactly the same steps leading from equation (2) to equation (5) above. The minimum phase property allows for a reduced state equalization since it is possible to choose M<L and write the model in the form:
r ~ → n = ∑ k = 0 M - 1 H ~ k [ a n - k b n - k ] + ∑ k = M L - 1 H ~ k [ a n - k b n - k ] + w ~ → n , ( 12 )
Where
r
~
→
n
=
[
ℛ
e
(
r
~
n
+
n
0
′
)
??
m
(
r
~
n
+
n
0
′
)
]
,
H
~
k
=
[
α
2
ℛ
e
(
h
~
k
′
)
-
2
-
α
2
2
??
m
(
h
~
k
′
)
α
2
??
m
(
h
~
k
′
)
2
-
α
2
2
ℛ
e
(
h
~
k
′
)
]
,
w
~
→
n
=
[
ℛ
e
(
w
~
n
)
??
m
(
w
~
n
)
]
.
The Viterbi trellis search is performed on a reduced trellis with 4 M transitions, and the remaining L−M taps corresponding to the second sum on the right hand of equation (12) can be fed back as in a decision feedback estimator. In FIG. 4 a view illustrating an exemplary receiver arrangement 400 using reduced state multi-user detection with single antenna interference cancellation is shown.
The receiver of FIG. 4 comprises a single input single output all-pass filter 401 . The all-pass filter can be adapted to receive a received input signal and a channel estimate. Using the all-pass filter will reduce the computational load on the receiver. The output from the all-pass filter is fed to a receiver block 403 . The receiver 403 can in accordance with one embodiment be adapted to perform the steps described above in conjunction with FIG. 3 . The method steps of FIG. 3 can for example be performed using a specially programmed computer 404 or a similar device such as an ASIC. The output from the receiver block is fed to reduced state equalization block 405 with M<L MLSE taps.
The receiving method and receiver as described herein provides improved receiver performance, surpassing the known technologies for interference suppression with only one antenna branch. The receiver achieves excellent performance in both interference and coverage scenarios with low complexity for VAMOS.
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A receiver, in particular a VAMOS receiver, is provided. The receiver is adapted to split the complex-valued baseband signal into its real and imaginary parts. The two branch system thus created is modeled as a real-valued Multiple Input Multiple Output, MIMO, system. The receiver is further adapted to use correlations of the noise, both in time and between branches of a channel to suppress the noise for multi-users in the same channel. In accordance with one embodiment the receiver is adapted to take into account the known symmetries present in a symbol constellation when more than one user exists in the same channel. This is for example the case in adaptive symbol constellation such as an adaptive alpha-QPSK constellation. Using the receiver in accordance with the above can provide the same performance as a joint detection receiver in the presence of Gaussian white noise, while giving better interference suppression than either SAIC or joint detection in the presence of GMSK modulated interference.
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This application claims benefit of U.S. Provisional application Ser. No. 60/298,517, filed Jun. 15, 2001.
FIELD OF THE INVENTION
The present invention relates to roofing systems.
BACKGROUND OF THE INVENTION
Rigid foam panels are currently available for use as an insulating underlayment in roof construction. Typically these are 4′ by 8′ (1.22 m by 2.44 m) panels 1.5″ (3.8 cm) thick made of a 1.6 pound per cubic foot polyurethane foam with a tar paper top layer. Such a material is not crush resistant enough to be used as a roof surface material and can also be easily punctured.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide a sturdy, weatherproof, seamless roofing system that uses rigid foam boards or panels to create a seamless waterproof roof.
SUMMARY OF THE INVENTION
The roofing panels of this invention differ from the prior art underlayment product in several respects. The panels of this invention are:
a) made of a denser polyurethane foam (approximately 3 pounds per cubic foot) and,
b) include an integral top layer of non-woven 250 gram polyester fabric that is saturated by the foam during manufacture by the laminator in a controlled factory environment.
The higher density affords more crush resistance, while the well bonded top layer resists punctures and provides a better adhesion surface for elastomeric top coats.
The roofing panels are bonded to roof substrate with low rise foam polyurethane adhesive which seeps through loose tongue-in-groove joints to form a blob at the top, which is shaved off and covered with a fabric top layer.
After the adhesive cures, a very secure bond between the panels results.
The low rise foam adhesive is a two-part mixture that has distinct phases after mixing. By varying the formulations of the two parts, the “cream time” (i.e.—to achieve the consistency of shaving cream) as well as the “tack free” time can be controlled.
The panels are placed on the foam just after cream consistency and well before tack-free time so that the foam rises through the joints. After the adhesive cures to a solid consistency, the blobs are removed from all of the joints. This is typically accomplished by grinding using a disk pad grinder.
The roof is finished by applying a layer of waterproof elastomeric coating which covers the entire surface creating a monolithic structure.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can best be understand in connection with the accompanying drawings, in which:
FIG. 1 is a top plan view of a roof section; showing outlines of roofing panels of this invention;
FIG. 2 is a top plan view of an embodiment for a tongue-in-groove roofing panel of this invention;
FIG. 3 is an edge crossection detail view of further embodiment for an all-groove panel of this invention with an insertable tongue board;
FIG. 4 is an edge crossection view of yet another embodiment for tongue-in-groove roofing panels of this invention, shown adhesively bonded to a roof substrate;
FIG. 5 is an edge crossection detail view of a still further alternate embodiment of this invention, shown with a ship-lap joint configuration;
FIG. 6 is an edge crossection detail view showing a panel joint of this invention in a finished roof section;
FIG. 7 is a high level flow chart of the roofing system method of this invention; and,
FIG. 8 is a roof edge detail view in crossection, illustrating flashing and interfacing to the roofing system of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The roofing system of this invention uses rigid foam boards or panels to create a seamless waterproof roof. It can be used over a number of different substrates including metal decking, tar and gravel, or polyurethane foam in new construction as well as re-roofing applications.
Rigid foam panels are currently available for use as insulating underlayment in roof construction. Typically these are 4′ by 8′ (1.22 m by 2.44 m) panels 1.5″ (3.8 cm) thick made of a 1.6 pound per cubic foot polyurethane foam with a tar paper top layer. Such a material is not crush resistant enough to be used as a roof surface material and can also be easily punctured.
The roofing panels of this invention differ from this underlayment product in several respects. Although panel size as well as material are similar, the panels of this invention are made of a denser polyurethane foam (approximately 3 pounds per cubic foot) and include an integral top layer of non-woven 250 gram polyester fabric that is saturated by the foam during manufacture by the laminator in a controlled factory environment. The higher density affords more crush resistance, while the well bonded top layer resists punctures and provides a better adhesion surface for elastomeric top coats.
FIG. 1 is a top view of a roof 1 section showing the outline of the individual roof panels. The panel seams are staggered by using alternate whole panels A as well as half panels B at the roof edge 2 . This is done to prevent any tendency for propagation of inadvertent seam separations.
FIG. 2 shows a top view of a tongue-in groove panel 5 tongue edges 6 and groove edges 7 .
Since a protruding tongue of polyurethane foam could be damaged in transit, an alternate embodiment of a tongue-in groove construction is shown in FIG. 3 . In this all-groove construction, each polyurethane panel 10 has grooves 11 cut in all four edges. A length of polyurethane plank 12 is then inserted in groove 11 on two edges at the work site. Plank 12 is dimensioned as a press fit in groove 11 and protrudes from the edge to form the tongue after insertion. Planks 12 would be shipped separately in protective packaging to the work site.
FIG. 4 is an edge crossection view of roofing panels 5 bonded to roof substrate 16 with low rise foam polyurethane adhesive 17 which seeps through loose tongue-in-groove joints to form a blob 18 at the top. Factory bonded fabric 15 is a top layer. Typically, the groove 7 is ⅞″ (22 mm) wide while the tongue is ¾″ (19 mm) wide; this affords enough space for the adhesive foam to rise through while affording close line-up of the top surfaces of adjacent boards 5 . After adhesive 17 cures, a very secure bond between panels 5 results.
FIG. 5 is a detail of an alternative panel joint. Here panels 20 have a ship-lap edge which is also dimensioned so as to permit rising foam adhesive to flow through the joint. For ship-lap panels 20 , the order in which they are laid into the foam is important.
As shown in FIG. 5, panel X should be laid down before panel Y so that there would not be a tendency to lift panel Y during the foam rising phase.
Foam adhesive is a two-part mixture that has distinct phases after mixing. By varying the formulations of the two parts, the “cream time” (i.e.—to achieve the consistency of shaving cream) as well as the “tack free” time can be controlled. For this invention, a cream time of about 1 minute and a tack-free time of about 4 minutes is ideal. The panels are placed on the foam just after cream consistency and well before tack-free time so that the foam rises through the joints.
After the adhesive cures to a solid consistency, the blobs 18 are removed from all of the joints. This is typically accomplished by grinding using a cutter, such as a knife or disk pad grinder. At this stage, the joint is flush with the fabric top surface of the adjacent panels.
The roof is finished by applying a layer of waterproof elastomeric coating which covers the entire surface creating a monolithic structure.
FIG. 6 is a detail of a finished joint between two panels 5 after the blob 18 has been removed and elastomeric coating 25 has been applied. Coating 25 can be an acrylic, urethane or silicone material. It can be sprayed or brushed on.
Flow chart 7 is a concise description of the overall installation process. Two people are generally involved as a team. One worker sprays a panel-width line of low rise polyurethane adhesive, while the second worker follows (after the mix is of cream consistency) and lay down panels. As per FIG. 1, the first panel at an edge is either a full or half panel to create the staggered seam pattern. Only after the entire roof (or large section) is paneled, are the seep-through joint blobs removed. All debris must be removed carefully before a final seal coat is applied.
Penetrations and wall flashings are first sealed with spray foam prior to sealing.
FIG. 8 is a detail at a roof edge showing an end panel 5 interfacing with aluminum edging 30 which bridges wall 31 , beam 29 and foam panel 5 . A V-groove 28 is cut from the corner of panel 5 at the juncture of edging 30 to permit an aluminum surface to be bonded and sealed to the fabric 15 top layer by waterproof coating 25 .
It is further noted that other modifications may be made to the present invention, within the scope of the invention, as noted in the appended claims.
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A crush resistant seamless roofing system is formed by a layer of adjacent panels having loose joints filled by expanding rising foam adhesive, which is trimmed to remove excess foam adhesive above a top plane of the roofing system. The roofing system thus formed is covered by a fabric layer and a coating.
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/985,646, filed Apr. 29, 2014, the entirety of which is herein incorporated by reference.
BACKGROUND
[0002] Friction materials used in high torque applications need to withstand high temperatures. One example application is in the context of synchronizer rings, which are commonly found in manual and dual clutch transmissions. Synchronizer rings are known to include an outer surface having a plurality of gear teeth, and an inner surface having a friction material bonded thereto by way of an adhesive.
[0003] One known type of friction material includes machined (i.e., cut) grooves. These friction materials include a consistent density and surface finish throughout. A second type of known friction material also includes pressed or molded grooves and a consistent surface finish throughout. However, unlike the first type, the material within the pressed/molded grooves has an increased density relative to the adjacent, raised material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] A method of forming a friction material according to an exemplary aspect of the present disclosure includes, among other things, depositing a plurality of particles on a substrate such that the particles provide a plurality of projections and channels between adjacent projections.
[0005] A friction material according to an exemplary aspect of the present disclosure includes, among other things, a working layer provided by a plurality of particles. The working layer includes a first section having a first surface finish and a first density. The working layer further includes a second section having a second surface finish different than the first surface finish and a second density different than the first density.
[0006] A system according to an exemplary aspect of the present disclosure includes, among other things, a mechanical component, and a friction material connected to the mechanical component. The friction material includes a working layer provided by a plurality of particles. The working layer further includes a first section having a first surface finish and a first density, and a second section having a second surface finish different than the first surface finish and a second density different than the first density.
[0007] The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The drawings can be briefly described as follows:
[0009] FIG. 1 illustrates an example mechanical component, which in this example is a synchronizer ring.
[0010] FIG. 2 is a flow chart illustrating an example method of making the disclosed friction material.
[0011] FIG. 3 schematically illustrates a hopper assembly, which may be used in the method of FIG. 2 .
[0012] FIGS. 4A-4B are cross-sectional views of the example friction material, and illustrate the friction material at various stages of formation.
[0013] FIG. 5 is a close-up view of the encircled area in FIG. 1 .
DETAILED DESCRIPTION
[0014] FIG. 1 illustrates an example mechanical component, which in the illustrated example is a synchronizer ring 10 . While a synchronizer ring 10 is illustrated, it should be understood that this disclosure extends beyond synchronizer rings. This disclosure is useful in other applications, such as other high torque applications, including, but not limited to, clutch plates and torque converters.
[0015] The synchronizer ring 10 includes a plurality of gear teeth 12 extending from a radially outer surface 14 thereof. During operation, a radially inner surface 16 of the synchronizer ring 10 is exposed to large amounts of heat. The radially inner surface 16 includes a friction material 18 bonded thereto by way of an adhesive. The synchronizer ring 10 may be made of steel or brass, as examples.
[0016] FIG. 2 illustrates an example method 20 for forming a friction material 18 according to this disclosure. In the method 20 , at step 22 , a plurality of particles 24 ( FIG. 3 ) are deposited onto a substrate 26 . The particles 24 may be selected from any number of materials including carbon, silica, glass, and vermiculite. The substrate 26 may be a carbon fiber weave, paper, textile, aramid, or cloth material, to name a few examples. In one example, the particles 24 are deposited onto the substrate 26 via a hopper 28 and a spreader 30 , which includes a plurality of elongate openings 32 , as illustrated in FIG. 3 . A spreader 30 is not required in all examples.
[0017] The result of step 22 is illustrated in FIG. 4A . In FIG. 4A , the friction material 18 includes the substrate 26 and a working layer 34 , which is provided by the particles 24 . The working layer 34 includes a plurality of projections 36 opposite the substrate 26 . The projections 36 are provided by the accumulation of particles caused by the elongate openings 32 in the spreader 30 .
[0018] After step 22 , the projections 36 are naturally provided with a rounded contour 38 . Further, the projections 36 are spaced-apart by a distance D 1 . The distance D 1 can vary depending on the particular application (e.g., depending on the size of the synchronizer ring 10 ). In one example, the distance D 1 is within a range of 0.1875 to 0.5 inches. In one specific example, D 1 is 0.375 inches.
[0019] The spaces between adjacent projections 36 define channels 40 . At the channels 40 , the friction material 18 has a height D 2 . The height D 2 may be relatively small in some examples. In particular, in one example, the distance D 2 may be such that the boundary of the channels 40 is provided by the substrate 26 . On the other hand, the friction material 18 has a height D 3 at the rounded contour 38 of the projections 36 . The distance D 3 is greater than the distance D 2 .
[0020] After step 22 , a resin R (schematically shown in FIG. 4A ) is applied to the friction material 18 , at step 42 . The particles 24 making up the working layer 34 absorb the resin R. Step 42 may be repeated to ensure an appropriate level of saturation.
[0021] At step 44 , the projections 36 are machined (e.g., sanded) to essentially flatten the previously rounded contours 38 . The flattened height is shown at D 4 . The height D 4 is less than D 3 and greater than D 2 in one example. FIG. 4A shows, in phantom, the flat contour 46 of the projections 36 . FIG. 4B shows the machined projections 36 exhibiting the flat contour 46 .
[0022] At step 48 , the friction material 18 is applied to the mechanical component, which in this example is the synchronizer ring 10 . In one example, which is schematically illustrated in FIG. 5 , the friction material 18 is bonded to the radially inner surface 16 of the synchronizer ring 10 by an adhesive layer 50 . Heat H and pressure P are applied to the friction material 18 , the adhesive layer 50 , and the synchronizer ring 10 to ensure a proper bond. The adhesive layer 50 may be any known type of adhesive suitable for high temperature applications. The adhesive layer 50 is provided between an outer surface 51 of the friction material 18 , which is opposite a radially inner working surface 53 of the friction material 18 .
[0023] The result of step 48 is shown in FIG. 5 . In FIG. 5 , the working layer 34 is compressed such that the friction material 18 has a substantially uniform height D 5 throughout. The height D 5 in one example is less than or equal to the height D 2 .
[0024] When compressed, the working layer 34 has alternating first sections 52 and second sections 54 . In this example, the first sections 52 correspond to locations where the projections 36 were provided (projections 36 are illustrated in phantom in FIG. 5 ). The second sections 54 , on the other hand, correspond to locations where the channels 40 were provided (channels 40 are shown in phantom in FIG. 5 ).
[0025] Because of the machining from step 44 , the first sections 52 have a first surface finish which is smoother than the surface finish of the second sections 54 . Since the second sections 54 are not machined in step 44 , the second sections 54 are left with a rougher, more granular surface finish (e.g., because of the unmachined nature of the deposited particles 24 ).
[0026] Further, because the first sections 52 correspond to the locations where the projections 36 once existed, the first sections 52 are more dense than the second sections 54 . The reasons for this increase in density is twofold. First, there were more particles forming the projections 36 than in locations adjacent the channels 40 . Thus, at step 42 , more resin R was absorbed by the projections 36 . Second, even after step 44 , the flattened projections 36 had a height D 4 greater than the height D 2 adjacent the channels 40 . Thus, when compressed in step 48 , the particles within the first sections 52 are packed closer together than the particles in the second sections 54 .
[0027] By providing the different first and second sections 52 , 54 , the friction material 18 exhibits good wear characteristics because of the relatively smooth surface of the first sections 52 at the working surface 53 . The friction material 18 also exhibits good friction properties because of the granular surface finish of the second sections 54 at the working surface 53 . The friction properties of the second sections 54 are particularly beneficial for cold shifting, as the granular nature of the second sections 54 helps to break the cooling fluid (e.g., oil) film adjacent the radially inner surface 16 of the synchronizer ring 10 .
[0028] Additionally, because the first section 52 has a higher density than the second sections 54 , cooling fluid is directed to the second sections 54 , and is allowed to permeate through the friction material 18 via the relatively lower density second sections 54 , which increases the cooling of the synchronizer ring 10 and the friction material 18 itself. This increase in cooling in turn increases performance of the synchronizer ring, and extends the life of both the synchronizer ring and the friction material.
[0029] In the example of FIG. 3 , the openings 32 are linear openings, which extend parallel to one another. This provides the friction material 18 with a plurality of linear, parallel first and second sections 52 , 54 . Other patterns, such as zig-zags, come within the scope of this disclosure, however. While parallel first and second sections 52 , 54 are mentioned above, the first and second sections 52 , 54 may not be parallel when applied to the radially inner surface 16 of the synchronizer ring 10 , as the radially inner surface 16 may be conical.
[0030] Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples.
[0031] One of ordinary skill in this art would understand that the above-described embodiments are exemplary and non-limiting. That is, modifications of this disclosure would come within the scope of the claims. Accordingly, the following claims should be studied to determine their true scope and content.
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One exemplary aspect of the present disclosure relates to a method of forming a friction material. The method includes depositing a plurality of particles on a substrate such that the particles provide a plurality of projections and channels between adjacent projections. This disclosure also relates to the friction material itself, and a system including a mechanical component and the friction material.
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This application is a Divisional of 09/658,087, filed Sep. 8, 2000, now U.S. Pat. No. 6,607,688, issued Aug. 19, 2003, which is a Continuation-in-Part of U.S. patent application Ser. No. 09/445,522, having a §102(e) date of Dec. 7, 1999, now U.S. Pat. No. 6,379,603, issued on Apr. 30, 2002, which was based upon PCT application PCT/US97/09916, filed Jun. 9, 1997.
FIELD OF THE INVENTION
The present invention relates to an improved gate design for drop gate injection molding of rubber compounds to form rubber articles. More particularly, the present invention relates to the unexpected combination of a drop gate with a lattice gate for increased gate heating efficiency and reduced cycle time while the rubber part is being injection molded.
BACKGROUND OF THE INVENTION
In a typical elastomer injection molding process, uncured viscous elastomeric compound is introduced into an elongated barrel of an injection molding machine at ambient temperatures. The compound is advanced through the barrel towards a mold connected to the downstream end of the barrel, usually by either a rotating screw conveyor or a reciprocating ram or piston disposed in the barrel. As the elastomeric compound advances, it is heated by heat conduction and mechanical shear heating in the barrel to reduce its viscosity and render the elastomer more flowable and amenable to subsequent injection into the mold. Typically, the less viscous the compound, the more easily it flows through a conventional gate system and the more easily it fills a mold cavity to produce a satisfactorily molded object.
One type of conventional gate for injection molded products is a “drop gate” design. This type of gate is used when a side injection system is not feasible depending upon the mold design used for certain injection molded products. With a drop gate, the elastomer is forced through a small diameter orifice and into the molded part. The majority of the shear heating occurs at the orifice area of the gate. FIG. 10 is a schematic drawing of a drop gate design 100 used to mold an article. A sprue pad 102 feeds elastomer to drop gate runners 104 . From the runners 104 , the elastomer flows through the drop gate orifices 106 , which have a smaller diameter than the drop gate runners 104 , and fills the mold cavity 108 .
WO 98/56559 discloses another gate design for injection molding rubber compounds. The gate design is a lattice gate. The lattice gate minimizes differences in temperature and pressure that result in a parabolic rubber flow through the gate. This is achieved by a series of crossed flow channels. WO 98/56559 teaches replacement of the conventional flat gate of the prior art with the inventive lattice gate.
SUMMARY OF THE INVENTION
The present invention is directed to an improved method and apparatus for a drop injection gate for molding rubber. The inventive method reduces curing time and improves the heat characteristics of the rubber as it is injected.
One aspect of the invention is an improved method of drop gate injection molding rubber. The method comprising injecting a rubber into a drop gate and through drop gate runners and into a mold cavity. The rubber flows at cross angles after the rubber is injected into the gate and before the rubber enters into the drop gate runners.
Another aspect of the invention is an improved drop injection gate for injection molding rubber into a mold cavity. The gate is comprised of drop gate runners. The gate has a region adjacent to the drop gate runners comprising a first and a second plurality of spaced flow channels disposed at intersecting angles to each other to create cross direction flow of the rubber before the rubber enters into the drop gate runners.
In another aspect of the invention, the drop injection gate has more than one separate region adjacent to drop gate runners comprising the first and second plurality of spaced flow channels disposed at intersecting angles to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described by way of example and with reference to the accompanying drawings in which:
FIG. 1 is a schematic representation of the inventive hybrid gate system;
FIG. 2 is an overhead view of the bottom plate of the lattice portion of the hybrid gate system;
FIG. 3 is a perspective view of the bottom plate;
FIG. 4 is an overhead view of the top plate of the lattice portion of the hybrid gate system;
FIG. 5 is the gate after the top and bottom plates have been assembled;
FIGS. 6 and 7 are section views of the gate along lines 6 — 6 and 7 — 7 of FIG. 5, respectively;
FIG. 8 is another embodiment of the bottom plate;
FIG. 9 is another embodiment of the bottom plate;
FIG. 10 is schematic representation of a conventional drop gate design used to mold an article.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is related to the design of an improved gate system for improving mixing and temperature uniformity and decreasing mold times in a drop gate mold injection system. The improved gate system is the unexpected combination of a lattice gate and a drop gate. FIG. 1 is a schematic representation of the inventive hybrid gate system 2 . The hybrid gate system 2 incorporates a lattice gate 4 after the sprue inlet 6 . Elastomeric material flows into the hybrid gate 2 through the sprue inlet 6 , and then flows through the lattice gate 4 . An outlet distribution channel 8 from the lattice gate 4 feeds the elastomer from the lattice gate 4 to the drop gate runners 10 . From the runners 10 , the elastomer flows through the drop gate orifices 12 and fills the mold cavity 14 .
The plates comprising the lattice gate 4 are illustrated in FIGS. 2 to 7 . FIGS. 2 and 3 illustrate the bottom plate 16 , also known as the gate plate. Offset from the center of the plate 16 is a distribution area 18 . Adjacent to the distribution area 18 is a plurality of flow channels 20 . At the opposing end of the flow channels 20 is a U-shaped outlet distribution channel 8 . The U-shaped outlet distribution channel 8 has a central portion 22 coincident with the ends of the flow channels 20 . At the terminal ends 24 of the side portions 26 of the outlet distribution channel 8 are ports 28 to the drop gate runners 10 .
The top plate 30 , also known as the sprue plate, is illustrated in FIG. 4 . Centrally located in the top plate 30 is the sprue bore 32 . Adjacent to the sprue bore 32 is a plurality of flow channels 34 .
When the flow channels 20 , 34 of the top and bottom plates 16 , 30 are formed into the respective plates 16 , 30 , as seen from overhead, the inclination direction of the channels 20 , 34 is identical. The plurality of flow channels 20 , 34 formed in the plates 16 , 30 are parallel to each other and inclined at angles β of about 30° to about 70°, preferably at angles of about 45° to about 60°, with respect to a centerline 36 . As the angle β of the parallel flow channels 16 , 30 increases with respect to the centerline 36 of each plate 16 , 30 , the time required for any elastomeric compound to flow through the channels 20 , 34 also increases, and vice versa. The flow channels 20 , 34 are illustrated with a semi-circular cross-section; however, it is within this invention to form the flow channels 20 , 34 with other cross-sections, such as elliptical, triangular, or square as desired.
FIGS. 5, 6 , and 7 illustrate the lattice gate 4 after the top and bottom plates 16 , 30 have been assembled. The sprue inlet bore 32 of the top plate 30 is aligned along a same axis with the drop gate ports 28 , while being offset from the center of the distribution area 18 of the bottom plate 16 . Also, the plurality of flow channels 20 , 34 are coincident with the edge of the distribution area 18 at one end, while the opposing end of the flow channels 20 , 34 are coincident with the central portion 22 of the outlet distribution channel 8 . As the elastomeric compound flows into the lattice gate 4 through the sprue bore 32 , the compound fills the distribution area 18 due to the injection pressure. The compound then flows into the cross directional flow channels 20 , 34 , exiting the flow channels 20 , 34 into the central portion 22 of the outlet distribution channel 8 . The injection pressure of the elastomer forces the compound to then flow through the side portions 26 of the outlet distribution channel 8 and through the drop gate runner ports 28 .
For the illustrated lattice gate configuration, spacing must be maintained between the flow channels 20 , 34 and the side portions 26 of the outlet distribution channel 8 . If this spacing is insufficient, the elastomeric compound may not travel completely through the lattice gate 4 , but it may enter the distribution channel 8 prior to complete mixing of the compound through the flow channels 20 , 34 . This spacing can be seen in FIG. 6 .
In the illustrated lattice gate configuration, the distribution area 18 has a predominantly circular configuration and depth greater than the flow channels 20 , 34 so that the injection pressure may be used to exert pressure on an essential component about which the elastomeric compound is to be molded; e.g. a central steel tube in a molded motor mount. The illustrated distribution area 18 is specific to a particular application. The shape of the distribution area 18 is designed to meet the needs of each specific molding application. For example, the distribution area 18 of a bottom plate 38 may be configured as a single portion flow channel 18 ′ connecting the sprue bore of the top plate to the flow channels 20 , 34 ; such a variation is illustrated in FIG. 8 .
Additionally, the outlet distribution channel 8 may have a configuration other than a U-shape. A U-shape outlet distribution channel addresses the need to have two spaced drop gate ports 28 feeding two drop gate runners 10 . If the specific molding application or injection machine permits, the outlet distribution channel 8 may have another configuration, such as a straight line flow channel 8 ′ with a central drop gate port 40 , as illustrated in FIG. 8 .
If the production of the molded article requires more than the illustrated two drop gate runners 10 , the shape of the outlet distribution channel 8 may be further modified to accommodate more drop gate orifices. Another alternative for an injection molding apparatus employing plural drop gate runners 10 is to form the top and bottom plates with multiple sprue inlets and lattice gate portions FIG. 9 illustrates a configuration that may be employed for the bottom plate 42 . The hybrid injection gate 2 has two separate lattice gates 44 . Each lattice gate has a distribution area 46 , flow channels 48 , a distribution channel 50 , and drop gate ports 52 . Such a hybrid gate 2 permits the use of four drop gate runners 10 to feed to mold cavity 14 .
The use of the lattice gate in combination with the drop gate, i.e. the inventive hybrid gate 2 , results in a faster cycle time for molding articles compared to the conventional drop gate system 100 . This is illustrated in the comparison tests set forth below.
Comparative Cure Time Tests
A 40-ton vertical injection molder was used for the test. The mold employed was a production engine mount mold with exchangeable top plates. The first set of top plates had a drop gate design delivery system only (schematically illustrated in FIG. 10 ). The second set of top plates had the lattice gate followed by an identical drop gate delivery system (schematically illustrated in FIG. 1 ). The drop gate design delivery system had a 0.229 cm (0.090″) injection orifice. The lattice gate had a structure of 45/5/0.099 cm/3.175 cm (channel angle/number of channels/channel radius/length) (45/5/ 0.039″/1.25″), and had a construction similar to the lattice gate 4 illustrated in FIG. 5 . For all of the runs, the mold temperature was 154° to 163° C. (310° to 325° F.), depending upon the location within the mold. The rubber temperature at the time of injection was 127° to 130° C. (260° to 265° F.). The top plates with the lattice gate design were not treated with any release coatings.
Engine mount bushings were injected on the 40-ton injector using bushing metals without adhesive to permit easy removal of the metal insert from the molded rubber. To determine the extent of cure, the rubber was cut open at the point of least cure. The size of the uncured region at the point of least cure gives a relative state of cure. The bushing was considered sufficiently cured if there was no sign of uncured or doughy rubber. While many of the parts that had uncured rubber inside immediately after injection would eventually have cured completely from the latent heat within the bushing, the intent of the comparative tests was to establish a baseline for comparison of the two gate designs. Thus, all comparisons were done by cutting the part open immediately after removal from the mold.
The minimum cure time for each type of gate was determined by reducing the cure time in successive steps until such time at which uncured regions were seen in the parts. The same elastomeric compound was used for all the trials. The compound used was a standard commercial product.
Comparison Cure Times
Injection
Cure
Total
Gate
time
Time
Cycle
Completely
Part No.
Type
(seconds)
(seconds)
time
Cured?
Comments
1
Hybrid
18
270
298
Yes
Fully cured
2
Hybrid
18
240
258
Yes
Fully cured
3
Hybrid
18
180
198
Yes
Fully cured
4
Hybrid
18
120
138
Yes
Fully cured
5
Hybrid
18
60
78
No
Part looks fully
cured, point of least
cure occurring at
center metal insert
6
drop
5
360
365
Yes
˜½″-¾″
D glossy spot
but no dough
7
drop
6
300
306
No
Process
conditioning part,
but had ˜1″ × ¾″
uncured area
Observations from Trials
In Part No. 5 , the bushing was almost completely cured at 60 seconds, but rubber porosity occurred at the interface between the smaller metal insert and the rubber. The metal insert acted as a heat sink, cooling the rubber at its surface and slowing the cure rate. A conservative estimate for Part No. 5's minimum cure time can be estimated at 90 seconds, this being extrapolated from the 60 second and 120 second cure times although the actual minimum cure time could be closer to 60 seconds.
In Part Nos. 1 to 5 , there was no significant flashing, i.e., all of the rubber traveled through the injection gate prior to entry through the drop gate runner orifice.
It was noted that for Part Nos 1 to 5 the injection time may be reduced by the use of release coatings on the lattice gate plates.
The use of the lattice gate in combination with the drop gate reduced the part cure time from 360 seconds to 90 seconds (see above discussion), the total cycle time for the part from 365 to 108 seconds. This is a 75% reduction in cure time and a reduction of over 70% in the total cycle time. Even if the minimum cure time for Part No. 5 is not extrapolated out to 90 seconds and the cure time of Part No. 4 is used instead to determine the cure time improvement, the cure time for Part No. 4 is reduced by 66%, and total cycle time is reduced by over 60%.
As discussed previously, the majority of rubber shear heating occurs at the orifice area of the gate. By incorporating a lattice gate prior to the drop gate, the hybrid injection gate is more efficient in heating the rubber prior to the rubber entering the mold cavity. This can be clearly seen by the substantially reduced cure times of the trial runs.
Using the hybrid concept permits the incorporation of the lattice gate into the gate design where the known plane of entry lattice gate design alone could not be used. The flow from the lattice gate is instead channeled through outlet distribution channels acting as mold runners to move the rubber to the drop gate and into the mold cavity.
The present invention of incorporation of a lattice gate with a drop gate is capable of reducing cure times required to mold parts. Such reduced cure times are especially beneficial for molded parts with very thick cross-sections. The mixing of the molding compound as it flows through the channeled entry lattice gate also improves the mixing and temperature uniformity of the molding compound prior to entry of the compound into the mold.
While the invention has been described in combination with embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing teachings. Accordingly, the invention is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and scope of the appended claims.
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The present invention is directed towards the hybrid combination of a drop gate injection molding system and a lattice gate. The lattice gate is located prior to the orifice of the drop gate. The lattice gate is comprised of a series of cross-direction flow channels through which the rubber flows, with mixing of the rubbers at the intersections of the flow channels. This hybrid molding system permits shorter cure times, and improved process cycle time for curing rubbers.
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[0001] The present application is a National Stage filing and claims priority to PCT/CH2006/000292 having an international filing date of Jun. 1, 2006.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a high-security cable, which is manufactured of a mixture of plastic yarns or of plastic yarns and metal wires.
[0003] High-security cables are used in many applications. Today, in particular, high-security cables are known, which are used as safety arrester cables, in particular for connecting a wheel of a racing car to its chassis. Such a safety arrester cable is known from WO 03/048602. The mentioned cable consists of a mixed yarn of threads with relatively rigid plastic filaments with an extension until breakage of 2 to 5%, and of relatively elastic plastic filaments with an extension to breakage of 12 to 25%. Here, the various plastic filaments are twisted into yarn strands, wherein the yarn strands are twisted in a balanced manner, whilst the cable manufactured of these yarn strands is twisted in an unbalanced manner. Such a cable not only has large tensile strength, but also an increased extension, by which means one may achieve an improved energy uptake. Given a full loading, the total energy is not transmitted directly to the anchoring, which often represents the critical location in the complete system, thanks to the accordingly increased energy uptake by the cable itself.
[0004] The known safety arrester cable which used in Formula 1 racing, may only have a relatively short extension path for reasons of safety, in order to prevent the broken-off wheel which now hangs on the arrester cable, from being thrown onto the cockpit or the head of the driver. However, a longer extension path would not only be acceptable, but, as the case may be, even desirable with other racing vehicles, or in other applications. The applicant has carried out further research and development in this direction, and has particularly sought after solutions which practically permit the creation of a customer-specific adaptation to the specifications.
[0005] Considering the so-called work-to-break-energy curve of any material, then such a curve in principle has the shape of an acute triangle in a coordinate system, with which the force is plotted on the abscissa and the elasticity E on the ordinate. The tensile strength of the material is reflected in the height of the triangle, and the elasticity of the material is represented by the inclination of the hypotenuse of the right-angled triangle. If then, different materials are processed into a cable, then usually the material-specific peaks are clearly recognisable in the complete enveloping curve. This leads to extremely unfavourable tear behaviour, depending on the load.
[0006] It is therefore the object of the present invention to provide a high-security cable which, on account of its special manufacture, is capable of achieving a smoothing of the work-to-break-energy curve, by which means, as a whole, the energy which may be absorbed until breakage is to be increased. This object is achieved by a high-security cable with the features claimed herein. The invention relates also to the use of such a high-security cable for different applications, which until now have not been considered for cable of this type. In particular, the expanded application also results due to the fact that the cables may be manufactured of a combination of filaments of one or more plastics, as well as of wires of one or more metals or metal alloys.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The present invention solves the aforementioned problem by providing a high-security cable capable of achieving a smoothing of the work-to-break energy curve.
[0008] According to one aspect of the invention, a high-security cable is manufactured of a mixture of plastic yarns or of plastic yarns and metal wires, wherein the cable comprises a first constituent part of untwisted or twisted yarns, or untwisted or twisted yarns and metal wires, a second constituent part of doubled yarn, the doubled yarn manufactured of plastic yarns or of plastic yarns and metal wires, and a third constituent part of cord manufactured from the doubled yarns, wherein the doubled yarn is manufactured from plastic yarns or of plastic yarns and metal wires.
[0009] Further advantageous designs of the subject-matter of the invention are to be deduced from the dependent claims. Their design, purpose and effect are explained in the subsequent description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention.
[0011] In the drawings:
[0012] FIG. 1 is a force-extension diagram for various materials, in a symbolic representation.
[0013] FIG. 2 is a further force-extension diagram of a single material, consisting of yarn, of double yarn and of cord.
[0014] FIG. 3 shows a force-extension diagram of a high-security cable, which is designed according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] High-security cables in most cases are manufactured of a single material, wherein one usually assumes the greatest force application which is capable of acting on the cable. Until now, one has used two or three different materials in a mixed manner only for reasons such as weather-durability, UV-durability and temperature-durability or other demands of a specific nature. Thereby, one has consistently limited oneself either to textile cables of natural fibres and plastic fibres, or purely metal cables. Cables which consist of both types of fibres and wires in a mixed manner, are not obtainable on the market.
[0016] As is schematically represented in the force-extension diagram of FIG. 1 the different materials which are indicated here as M 1 , M 2 , M 3 or M 4 , have different modules of elasticity and different maximal loads-to-break (load-to-break curves). The respective curves symbolically represent mono-filament or multi-filament cables without twisting. Such curves have a more or less steep flank, a relatively small maximum plateau up to maximal extension, which leads to breakage.
[0017] In a large series of trials, the applicant has now found that the curves change, if instead of a simple yarn in a twisted form or untwisted form, one processes this further into doubled yarns or to cord. With this, it has been found that this form of further processing permits the flank of the gradient curve to become less steep, and, depending on the type of processing, one may maintain the maximal force transmission over a longer extension path. In other words, the previously pointed curves, as are known from FIG. 1 , may be stretched out. By way of this, the curves flatten inasmuch as the extension path also increases given an increasing increase of the force, wherein this occurs in the initial phase, as well as further increasing with the maximal force which may be applied. The total work which such a cable is capable of absorbing, is represented by the area below the enveloping curve.
[0018] However, depending on the application, it is however not at all desirable to obtain a respective extension already before the maximum force is present. The object of the invention is to be seen in providing a cable which has an as small as possible extension path up to reaching the maximal applicable force, but to permit an as large as possible extension up to breakage when applying the maximal force. The maximal work which may be absorbed, may be optimised by way of this.
[0019] Now, an example is shown by way of the force-extension diagram according to FIG. 3 , with which four different materials symbolised by M 1 to M 4 are processed, wherein all materials are present in the form as a yarn or wires, as well as in the form of doubled yarns, and finally in the form of cord. One may realise a curve which may be symbolically displayed practically as a rectangle, by way of the presence of these materials in all three processed forms, wherein each material does not necessarily have to be present in all three processed forms, although this definitely represents the most optimal design.
[0020] Since the definitions of the terms used here are not uniform on an international level, the terms are hereinafter defined as are to be understood in the present invention. The smallest element is a monofilament or a single wire. Here, the fineness of the wire is not fixed. In the present invention, yarn is to be understood as an endless product consisting of several filaments. Here, the yarn may be non-twisted or twisted. A yarn according to the invention may analogously also consist of a multitude of fine metal wires. These metal wires too may be non-twisted or twisted.
[0021] With regard to the invention, a doubled yarn is to be understood as a product which consists of two yarns which are wound with one another. Each yarn may be S-twisted or Z-twisted. Here, S-twisting is to be understood as a left-hand twisting and Z-twist is to be understood as a right-hand twisting.
[0022] The individual yarns not only vary in the twist direction in which they are twisted, but they also differ in the number of twists per meter. This measure number may vary in the magnitude from about 30 twists per meter up to maximally 600 twists per meter. Whilst the S-twisting or the Z-twisting may be used independently of the type of material, the variation of the twists per meter may be dependent on different factors, such as for example the stiffness of the materials and of course on the effect to be achieved. Basically it is the case, that the lower the twisting, the lower is the extension path until breakage, wherein however one should additionally take into account the fact that although the extension path until breakage increases with a very large number of twists per meter, the maximal force until breakage is however reduced. The latter is particularly the case with yarns, which are completely manufactured of metal, or for yarns which contain a metal component.
[0023] As already mentioned, with regard to the invention, one advantageously assumes cords which consist of three yarns. Thereby, within a cord, the variation of the yarns applied therein, with regard to the properties of the materials, as well as with regard to the number of twists per meter, should not be too great. One may deduce various cords as well as their composition of different yarns, from the subsequent table, wherein only the details with regard to the twists of the yarn are specified, but not their material composition.
[0024] With regard to the materials being considered here, one may essentially ignore the purely natural fibres. Apart from the known carbon fibres with tensile strength of 20 cN/dtex, the essentially more elastic m-aramide fibres which have a tensile strength of 4.7 CN/dtex are of course also considered here. The mentioned elastic m-aramide fibres may also be combined very well with the relatively rigid p-aramide fibres, which have a tensile strength of 19 cN/dtex. The very modern PBP-fibres which even have a tensile strength of about 37 cN/dtex, have a particularly high tensile strength. Cables which are manufactured of such high tensile fibres are capable of accommodating tensile forces which far exceed the usually occurring forces. Despite this, often such high-security cables which are manufactured of such high tensile materials, are extremely problematic on application. The smallest elastic extension up to breakage of only 1.5 to maximal 3.5% limits their application. The cables must be able to absorb a part of the energy via the extension, wherever very high forces may occur during a relatively short period of time, since otherwise the occurring brief, enormously high forces only lead to a destruction of the fastening points of the cables. Even then, when these fastening points are able to be dimensioned significantly greater than the cables in many cases, according to experience, problems occur at the fixation points.
[0025] In order to increase the deformation work which is undergone by the cable, the admixture of metal wires which may be integrated either in the yarn or the cord, in particular by way of a so-called core-spinning method, is particularly suitable, wherein the metal wire or wires lie in the centre, whilst the plastic yarns run around them. With regard to the metal wires of interest here, of course various steel wires are to be considered, but in particular also wires of nickel or of an austenitic nickel-chrome alloy have proven their worth. Austenitic nickel-chrome alloys were processed in the form of wires with a diameter of below 0.5 mm into doubled yarns, and these processed further into a cable with a diameter of 12 to 13 mm. Such a cable with a length of 600 mm permits the transmission of a maximal force of 57.8 kN. The work-to-break here was also 10′000 Nm.
[0026] What is essential according to the present invention, is the fact that the cable must consist of three different constituent parts, specifically on the one hand of yarns, on the other hand of doubled yarns, and thirdly of cords, wherein simultaneously, of each material constituent part, this material should be present as yarn as well as doubled yarn and as cord. Only thus is it ensured that the three different extension regions of the same material may also be utilised.
[0027] It is only due to the combination of all three processing steps that the maximal extendibility of the material is also fully utilised. Although the processing of metal wires in the high-security cable according to the invention is not absolutely necessary, such wires have been found to be extremely advantageous for covering certain extension ranges. In the case that the high-security cable contains shares of p-aramide fibres, m-aramide fibres or PBO-fibres, then the share of these fibres which have a tensile strength of more than * cN/dtex energy, must consist mostly of the constituent parts of yarn and cord, but to a lower extend as pure cord.
[0028] The application of such high-security cables according to the invention is hardly suitable for cables which merely need to transmit a relatively constant high tensile force. However, the high-security cables according to the invention may be applied wherever extreme high peak loads of a high-security cable occur. In particular, tests have shown that such safety arrester cables are suitable for application in sports car racing, for connecting a wheel to the chassis of the racing car. It has been found that with such an application, it makes sense to design the cable according to the invention such that several windings are shaped into parallel loops, so that at least one open loop is formed at the open end.
[0029] A further field of application of these cables according to the invention lies in the fact that these may be used in order to make safety arrester cables therefrom, which may be attached along ski slopes, and in particular along the race circuits in alpine sports.
[0030] High-security cables may only fulfil the safety standards demanded of them when these are applied under clear conditions. Accordingly, they are hardly suitable for long-term falling-stone arrester structures or avalanche protective structures. The prevailing environmental influences over a longer period would manifest themselves with regard to the performance of the high-security cable. However, the high-security cables may be advantageously be processed into nettings which may serve as a temporary avalanche protector netting. Accordingly, such cables may also be processed into nettings as temporary falling-stone arrester netting.
[0031] The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.
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A high-security cable is provided, wherein the high-security cable is capable of achieving a smoothing of a work-to-break energy curve. The high-security cable is manufactured of a mixture of plastic yarns or of plastic yarns and metal wires, wherein the cable comprises a first constituent part of untwisted or twisted yarns, or untwisted or twisted yarns and metal wires, a second constituent part of doubled yarn, the doubled yarn manufactured of plastic yarns or of plastic yarns and metal wires, and a third constituent part of cord manufactured from the doubled yarns, wherein the doubled yarn is manufactured from plastic yarns or of plastic yarns and metal wires. The high-security cable can be used as a safety arrester cable, and can also be used to form a netting to serve as safety arrester netting or falling-rock protection netting.
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BACKGROUND
[0001] Gas turbine engines include alternating stages of rotating blades and stationary vanes. Each vane stage comprises a plurality of stator segments. A segment could include a plurality of vanes extending between an outer platform and an inner platform. Stator segments are commonly formed by casting or by brazing.
[0002] To relieve any build-up of stress caused by temperature gradients in the vanes and platforms during engine operation, the inner platform typically includes relief slits between adjacent vanes. These relief slits also help isolate vanes from vibration modes of adjacent vanes. The stator segment also includes a damper to reduce vibration amplitudes, thereby helping prevent vane cracking.
SUMMARY
[0003] According to an embodiment shown herein, stator for a turbo-machine having a plurality of airfoils extending radially therefrom has a base from which the airfoils depend, and slits disposed in the base, each slit disposed adjacent a pair of airfoils, wherein first set of adjacent slits and a distance between a second set of adjacent slits varies.
[0004] According to a further embodiment shown herein, a gas turbine engine stator having a plurality of airfoils depending radially inwardly therefrom has a base from which the airfoils depend, and slits disposed in the base, each slit disposed between a pair of airfoils, first set of adjacent slits and a distance between a second set of adjacent slits varies.
[0005] According to a still further embodiment shown herein, method for creating a stator having a plurality of blades depending therefrom includes the steps of designing slits, each slit disposed between a set of adjacent blades, wherein the slits have varying distances therebetween wherein a first area between a first set of the slits has a first frequency mode that is not in tune with a second area between a second set of the slits having a second frequency mode, and creating the slits within the stator.
[0006] Although different examples have the specific components shown in the illustrations, embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components of another of the examples.
[0007] These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic view of a gas turbine engine that incorporates an embodiment disclosed herein.
[0009] FIG. 2 is a top, segmented, view of a portion of FIG. 1 taken along the lines 2 - 2 .
[0010] FIG. 3 is a bottom view of FIG. 2 .
[0011] FIG. 4 shows a method of determining spacing within the embodiment shown in FIGS. 2 and 3 .
DETAILED DESCRIPTION
[0012] Referring to FIG. 1 , an example turbo-machine, such as a gas turbine engine 10 , is circumferentially disposed about an axis A. The gas turbine engine 10 includes a fan 14 , a low pressure compressor section 16 , a high pressure compressor section 18 , a combustion section 20 , a high pressure turbine section 22 , and a low-pressure turbine section 24 . Other example turbo-machines may include more or fewer sections and different arrangements.
[0013] During operation, air is compressed in the low pressure compressor section 16 and the high pressure compressor section 18 . The compressed air is then mixed with fuel and burned in the combustion section 20 . The products of combustion are expanded across the high pressure turbine section 22 and the low pressure turbine section 24 .
[0014] The low pressure compressor section 16 and the high pressure compressor section 18 include low pressure rotors 28 and high pressure rotors 30 , respectively. The high pressure turbine section 22 and the low pressure turbine section 24 each include high pressure rotors 36 and low pressure rotors 38 , respectively. The rotors 36 and 38 rotate in response to the expansion to rotatably drive the high pressure compressor section 18 and the low pressure compressor section 16 .
[0015] The rotor 36 is coupled to the low pressure rotor 28 with a spool 44 , and the rotor 38 is coupled to the rotor 30 with a spool 46 . Bearings rotatably support the spools 44 and 46 during operation of the gas turbine engine 10 .
[0016] A plurality of vanes, for instance, low pressure compressor vanes 48 , high pressure compressor vanes 50 , high pressure turbine vanes 52 and low pressure turbine blades 54 are interspersed between the rotors 28 , 30 , 36 , 38 to direct air as it passes between sections of the engine 10 . The blades may also be referred to as airfoils.
[0017] The examples described in this disclosure are not limited to the two-spool gas turbine architecture described, however, and may be used in other architectures, such as the single-spool axial design, a three-spool axial design, and still other architectures. That is, there are various types of gas turbine engines, and other turbo-machines, that can benefit from the examples disclosed herein.
[0018] Referring now to FIGS. 2 and 3 , an example stator 56 has a plurality of segments 70 (one of which is shown in FIG. 2 ) that abut each other to form a ring (shown in FIG. 1 ). An example stator 56 may have seven or eight such segments 70 connected end-to-end to each other. Each segment has a radially curved base 75 having forward end 80 and aft end 85 . A forward side wall 90 and an aft sidewall 95 each extend radially upwardly from forward end 80 and aft end 85 of the base 75 respectively. Forward brim 100 extends forward axially from side wall 90 and aft brim 105 extends aft from side wall 95 such that the brims 100 , 105 do not extend over the base 75 . A sheet (not shown), usually made of a shaped metal, may be placed against the base 75 between the sidewalls 90 , 95 to damp structural vibrations in the segments.
[0019] Depending downwardly from the base 75 , a plurality of vanes 50 (e.g., blades or airfoils) extend. The vanes 50 and the segment 70 may be formed together as clusters to minimize the costs of manufacturing a segment. The vanes 50 have a curved cross-sectional shape 110 that is contained on the base 75 . Each vane 50 has a forward end portion 115 and an aft end portion 120 . The vanes 50 may be angled relative to Axis A as may be required by the requirements of the engine 10 .
[0020] It has been discovered by the Applicants herein, that a segment 70 made in a cluster and that has multiple vanes or airfoils may have very similar vibratory modes to other segments, which can result in resonance or mistuning that could shorten the life of a segment. Harmonious vibratory modes may be destructive to a lifespan of a segment 70 .
[0021] Between each vane 50 , a slit 125 is disposed (e.g., cut or formed or the like) that extends through aft brim 105 , aft side wall 95 and into the base 75 at an angle corresponding to the disposition of the vanes 50 from the base 75 . The slits 125 are not regularly spaced and the distance or widths W between slits 125 differ. For instance width W (including an area including a vane/airfoil and a piece of the base 75 ) may be different from width W 2 or width W 3 or width W n . The depth of each slit 125 may vary though they may extend to the forward end portion 115 of the airfoil/vane 50 . The width of each slit 125 may also vary though they may be kept uniform for ease of construction. The slits 125 may be filled with a damping material 127 such as an elastomer or the like, which may further limit vibratory modes and act to minimize the flow of air through the slits 125 . The slits 125 may also be mechanically blocked by a damping sheet 127 (see FIG. 2 ) or the like. The slits 125 extend radially through the base 75 from a top 130 to a bottom 135 thereof. There may be a slit 125 between or adjacent to each vane 50 . The slits 125 may be skewed relative to each other to improve the (dis)harmonics of each width W.
[0022] Though the segment 70 demonstrated herein is used in the high pressure compressor section 18 of the engine 10 , one of ordinary skill in the art recognizes that the teachings herein may be used in other sections of the engine 10 .
[0023] Referring now to FIG. 4 , a method of creating a segment using widths W n is shown. The varying widths/distance W n that create discordant resonant frequencies are determined that deliberately mistune each width relative to other widths (step 205 ), operation of the segment 70 with varied widths is simulated (step 210 ), the efficacy of chosen widths as to the life of the segment 70 (e.g., minimize damage to the segment 70 ) in reaction to the chosen widths W n is determined (step 215 ) and the slits are created if appropriate (step 220 ). In essence, each width is a tuning fork with given vibratory modes that might combine with other modes that may damage the segment 70 . By varying each width W n and each width's attendant vibratory modes thereby, a non-destructive discordance is created.
[0024] Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.
[0025] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.
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A stator for a turbo-machine having a plurality of airfoils extending radially therefrom has a base from which the airfoils depend, and slits disposed in the base, each slit disposed adjacent a pair of airfoils, wherein a first set of adjacent slits and a distance between a second set of adjacent slits varies
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This is a continuation of application Ser. No. 765,266, filed Feb. 3, 1977 now abandoned.
BACKGROUND OF THE INVENTION
The invention is generally related to water distributing systems and devices, and is specifically directed to a center-pivot, field irrigation system capable of operating at low or high water pressure, and a constant-volume sprinkler head for such irrigation systems.
Center-pivot irrigation systems typically comprise an extremely long water conduit "arm", which is pivotally connected at one end to a source of water under pressure. The conduit arm is carried in an elevated position, usually by a plurality of radially spaced wheeled towers which are powered by hydraulic, pneumatic or electrical motors to rotatably sweep the conduit arm through and over a circular field. The conduit arm includes a predetermined number of water sprinkling heads, which are radially spaced over its length and constructed to distribute a spray of water on the circular or annular field area over which they pass.
Center-pivot irrigation systems have strongly and successfully established themselves in the farming community. Although initially expensive, they presently represent one of the most efficient manners of irrigation, insuring that most of the crop receives an adequate supply of water and thus increasing crop yield.
For some period of time, center-pivot irrigation systems have operated a reasonably high water pressure, typically on the order of 70 psi. This has been environmentally and economically unsound, since such levels of operation require more elaborate pumping equipment, as well as conduit and sprinkler heads capable of withstanding such pressures. High pressure equipment is more expensive to operate due to fuel consumption. Further, the extreme pressure causes substantial evaporation of the water for at least two reasons. First, the water is often propelled through the air for significant distances where higher pressures are used, and the more exposure to the air, particularly when it is dry, the greater the degree of evaporation. Secondly, irrigation systems of this type often create a spray by directing a high velocity water jet against a deflector. The resulting spray is a fine mist, at least in part, which is highly subject to evaporation before it reaches the ground, and the problem is severely compounded by windy conditions, which also tend to blow the spray away from the intended area.
Consequently, many of the newer systems have been designed to operate at low water pressure, typically on the order of 20 psi. Lower pressures clearly have the advantage of less operating cost, and there is usually less evaporation under still conditions. However, evaporation and misdirection of the spray pattern have continued to be a problem under windy conditions, resulting in erratic and nonuniform distribution of water over the field. Nonuniform distribution is even more pronounced where differences in elevation occur in the field even where such differences in elevation occur in the field even where such differences are not great. A severe pressure drop occurs wherever there is any degree of elevational difference in the conduit arm. This results in poor water distribution in the high areas of the field, whereas over watering occurs in the low spots. Thus, the field becomes "spotted" with areas which have received too little or too much irrigation, and much or all of the advantage of low pressure irrigation is lost. This is not, of course, conducive to optimum crop yield.
The inventive irrigation system and sprinkler head therefore are the result of an endeavor to develop a low pressure center-pivot system capable of uniformly distributing water over the field notwithstanding differences in elevation or windy conditions, and that overcomes high percentage water losses due to evaporation.
The irrigation system comprises an elevated conduit arm that is pivotally connected to a stationary point (usually the well pipe), and is powered to rotatably sweep through and over the field. The system further comprises a plurality of sprinkler heads spaced over the length of the conduit arm, each of which is constructed to create a spray formed from water droplets that are large enough to resist being blown off-course by the wind, but not so large as to damage farm plants that may be small and fragile after sprouting and during early development.
Because the area of a circular field increases exponentially as the field radius increases, the system must be properly designed to insure that the sprinkler heads have the capacity to cover the entire field with a sufficient volume of water, and that this predetermined volume is uniformly distributed even without elevation differences or windy conditions. Thus, assuming that the sprinkler heads are equidistantly spaced, each successive head in the radially outward direction generally must have a greater output capacity since the annular area which it overlies is greater than the annular area which next precedes it. Stated otherwise, although the annular band width of all sprinkler head areas may be essentially constant with equidistant spacing, each successive area nevertheless increases appreciably because its effective radius increases. Accordingly, the output capacity of each sprinkler head must be chosen to deliver the proper volume of water per unit of time based on the specific area which it overlies and serves.
Although I prefer increasing the output capacity of successive sprinkler heads as a function of their radial distance from the pivot point, it would be possible to use sprinkler heads of the same output capacity and decrease the spacing therebetween as a function of increasing radial distance from the pivot point. Because the output capacity of my unique sprinkler head can be varied much more easily (due to interchangeability of control components) than can sprinkler head spacing on the conduit arm, the equidistant spacing approach is strongly preferred. This is particularly so since proper water distribution is necessarily conditioned on geographic area, annual rainfall, type of crop and the like. Further, many existing systems already have equidistantly spaced sprinkler heads but can be readily converted to the inventive system.
Having designed the system to be capable of uniform and sufficient water distribution over the entire field, the problem of pressure fluctuations due to differences in elevation can be overcome on an individual sprinkler head basis. This is accomplished through the use of a volume control device within the sprinkler head that maintains a constant volume output even in the face of water pressure fluctuations in the conduit arm. Thus, assuming that water under a predetermined minimum pressure of sufficient volume is always supplied to the conduit arm, the individual sprinkler heads respond to the delivered pressure and distribute the same volume of water in the same spray pattern throughout all phases of the operation.
I have overcome the problem of wind affects by designing a sprinkler head that creates a flow pattern that is less than 360°, and which is always directed into the wind. This is specifically accomplished with a deflector designed to create the desired flow pattern upon impingement by a low pressure water jet. The deflector is mounted for rotation in an essentially horizontal plane and includes a wind-sensitive vane that always keeps the deflector in a position directing the spray into the wind. The deflector is also constructed to be tipped about an essentially horizontal axis, and aileron-like devices are also included which cause the deflector to tip under severe windy conditions, directing the spray pattern somewhat downward as well as into the wind.
I have found that the inventive low pressure, center-pivot irrigation system employing these unique sprinkler heads successfully combats the problem of uneven water distribution and spotty crop production due to differences in elevation, windy conditions, friction loss and water evaporation. Further, since the sprinkler head is designed with component interchangeability in mind, an irrigation system can be custom designed to the conditions of a specific field with very little difficulty.
The inventive irrigation system and sprinkler head include a number of additional advantageous structural features, which will become apparent from the drawings and description below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary view in side elevation of a low pressure, center-pivot irrigation system embodying the inventive concept;
FIG. 2 is a schematic and graphic representation of the irrigation system and one-half to the field which the system irrigates;
FIG. 3 is an enlarged view in side elevation of a sprinkler head constructed in accordance with the inventive concept;
FIG. 4 is a view in top plan of the sprinkler head;
FIG. 5 is an enlarged fragmentary sectional view of the sprinkler head taken along the line 5--5 of FIG. 4, showing the component construction in detail in a first operating state;
FIG. 6 is a further fragmented view of FIG. 4 with the sprinkler head in a second operating position;
FIG. 7 is a fragmentary sectional view of the sprinkler head taken along the line 7--7 of FIG. 3;
FIG. 8 is a fragmentary sectional view of the sprinkler head taken along the line 8--8 of FIG. 3;
FIG. 9 is an enlarged perspective view of a spray deflector used in the sprinkler head;
FIG. 10 is an enlarged fragmentary sectional view of an alternative embodiment of portions of the sprinkler head;
FIG. 11 is a fragmentary sectional view taken along the line 11--11 of FIG. 10;
FIG. 12 is a perspective view of a constant-volume flow control device used in the alternative sprinkler head;
FIG. 13 is an enlarged fragmentary sectional view similar to FIG. 5 of an alternative embodiment of the sprinkler head, in a first operating position;
FIG. 14 is a further enlarged fragmentary sectional view of the sprinkler head shown in a second operating position;
FIG. 15 is a fragmentary sectional view taken along the line 15--15 of FIG. 13;
FIG. 16 is an alternative embodiment in perspective view of an auxiliary flow structural component for the sprinkler head;
FIG. 17 is a view in bottom plan of the auxiliary flow component of FIG. 16;
FIG. 18 is a further alternative embodiment in perspective view of an auxiliary flow structural component for the sprinkler head; and
FIG. 19 is a view in bottom plan of the auxiliary flow component of FIG. 18.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With initial reference to FIG. 1 a center-pivot irrigation system constructed for operation at low water pressures is represented generally by the numeral 11. Irrigation system 11 consists of an extremely long water conduit "arm", which is made up of a plurality of conduit sections 12a-12g which are serially connected to permit the flow of water over the entire length. One end of the conduit arm is pivotally connected to a source of water under pressure, such as a well pipe, and this connection is generally designated 13 in FIG. 1. The conduit arm is carried in an elevated position by a plurality of wheeled "towers" 14a-14g, the towers being disposed at the interconnection points of the conduit sections 12a-12g as shown. As such, there are the same number of towers as conduit sections, thus providing adequate support for the entire length of the water conduit arm. Supportive structure for each of the conduit sections 12a-12g is generally designated 15 in FIG. 1.
As is well known in the art, the wheeled towers 14a-14g are motivated hydraulically, pneumatically or electrically in a coordinated manner so that the conduit arm rotatably sweeps through and over a field relative to the center pivot 13.
Each of the conduit sections 12a-12g includes a plurality of water sprinkling or spray heads 16 which are equidistantly spaced over the entire length of the water conduit arm. With additional reference to FIG. 2, it will be seen that the irrigation system 11 is designed to irrigate a circular field having a diameter of 2800 feet, which is approximately 1/2 mile. Thus, the water conduit arm has a radial length of 1400 feet, and each of the 7 conduit sections 12a-12g is 200 feet long and includes 20 equidistantly spaced spray heads 16 to distribute water over its associated annular area. Thus, this particular irrigation system includes 140 spray heads which are designed to deliver a predetermined volume of water as described in further detail below. It will be appreciated to the person of ordinary skill that this irrigation system is exemplary, and it is possible for the system to be of varying lengths, depending on the field size, with varying numbers of conduit sections. The irrigation system may also include a greater or lesser number of spray heads having different volume flow capabilities, the objective being to distribute a predetermined volume of water onto the field in a given amount of time as uniformly as possible.
As shown in FIG. 2, the circumferential distance traveled by each spray head varies significantly based on its radial distance from the center pivot 13. The figures extending radially outward to the left in FIG. 2 represent the circumferential distances traveled by the respective towers 14a-14g as they move through the field. As an exemplary comparison, the outermost tower 14g travels approximately 4398 feet in one revolution of the conduit arm, whereas the innermost tower 14a travels only 628 feet through the same revolution. Thus, the tower 14g travels seven times the distance traveled by tower 14a, and a comparison of the volume of water distributed by a spray head 16 proximate the tower 14g and one proximate the tower 14a must reflect the difference in travel. Generally, where the spray heads 16 are equidistantly spaced over the length of the conduit arm, as with the irrigation system 11, the water distributing capacity of a given spray head must be established as a function of its radial distance from the center pivot 13. In the preferred embodiment, each spray head 16 has a water distributing capacity which is directly related to the distance it travels and the annular area which it irrigates; and its capacity in this respect is therefore greater than the spray head 16 which is radially inboard and less than that of the spray head 16 which is next radially outboard. It may also be possible to arrange the spray head 16 in groups or sets of two or three having the same water distributing capacity, with the set capacity increasing as a function of radial distance from the center pivot.
Where each spray head 16 has a different water distributing capacity, as in the preferred embodiment, I also prefer to identify each one with some type of symbol which is visually discernible at a distance. Thus, with reference to FIG. 3, the spray head 16 shown in side elevation includes the numeral "1", which quickly identifies it as the first or innermost spray head 16 in the conduit arm. Of course, the spray head identification may vary from system to system. For example, rather than a progressing continuous number sequence, it may be desirable to also identify the spray head by a letter which corresponds to the particular conduit section to which it belongs; e.g., A-1, 2, 3 . . . 20; B-1, 2, 3 . . . 20, etc. The objective of spray head identification is that the user be capable of quickly identifying the specific position of a specific spray head simply by observation. This is highly important where the system is custom designed to a particular field, and the agricultural user is not well versed on water distributing capacity in terms of outlet orifice sizes, inlet pressures, volume control rates and the like.
FIGS. 3-9 disclose the specific construction of a spray head 16 which is uniform throughout the system, with the exception that some of the components are interchangeable to vary its water distributing capacity.
Each spray head 16 is connected directly to its associated section of the water conduit arm for fluid communication therewith. This is accomplished through the use of an adapter 17 which is rigidly secured to the conduit section, as by a threaded connection, and which includes a threaded nipple 18 (FIG. 5). Each of the spray heads 16 includes an upright housing 21 generally taking the form of an enclosed bowl, the lower end of which defines an internally threaded inlet permitting it to be rigidly screwed onto the threaded nipple 18 to define a housing inlet. The housing 21 in turn consists of a lower bowl portion 22 and a cover portion 23 which are threadably or otherwise mated as best shown in FIGS. 5 and 6. The upper end of the cover 23 defines a central outlet disposed in axial alignment with the housing inlet and the threaded nipple 18.
A nozzle member 24 of circular cross section and having an outlet of predetermined diameter is sized to frictionally project through the outlet of housing 21, being held in place by a retaining flange 24a. The outer diameter of the retaining flange 24a corresponds to the inner diameter of a cylindrical member 25 which projects axially downward in alignment with the housing inlet and outlet. Cylindrical member 25 is integrally formed with the cover 23 and open at its lower end. A conical filter screen 26 is held in place over the open end of the cylindrical member 25 by a retaining clip 27 or other suitable means.
A ring 28 is secured to the inner surfaces of cylindrical member 25, axially spaced from the end surface of the flange 24a to define an annular recess. A resilient washer 31 is disposed in the annular space, having a thickness generally corresponding thereto. In its nomral form, resilient washer 31 is concavo-convex so that its outlet side is spaced from the end surface of the flange 24a with the exception of a peripheral region of contact with the flat undersurface of the flange 24a. Washer 31 is formed with a fluid control passage 31a which is of uniform internal diameter in its normal state, such diameter being somewhat less than the internal diameter of the nozzle member 24.
As described, the resilient washer 31 serves as a control element to maintain the output of the spray head 16 at an essentially constant volume notwithstanding fluctuations of water pressure within the water conduit arm. More specifically, water entering the housing 21 through the threaded nipple 18 generally takes the form of a water jet. Upon striking the conical screen 26, it is dispersed outwardly to exert a uniform force over the bottom surface of washer 31. The washer 31 is designed to resiliently deform over a predetermined range of pressures. In the lower range, the washer 31 maintains the conical form shown in FIG. 5, and the control passage 31a remains in its widest position to permit the greatest volume of water to pass therethrough. At the higher end of the pressure range, the washer 31 deforms toward and ultimately into a flat position as shown in FIG. 6, increasingly engaging the flat undersurface of flange 24a, with the passage 31a becoming more and more restrictive on the inlet side. This has the effect of restricting the volume of water passing through and into the nozzle member 24. However, the volume of water is essentially the same since the pressure is increased to deliver the same amount of water through the smaller passage.
Between the lowest and highest pressures, the resilient washer 31 deforms in a modulating manner so that the proper volume of flow always leaves the nozzle 24.
The annular space between the outer surface of the cylindrical projection 25 and the inner surface of the housing 21 serves to capture air, which is compressed by the water within the housing 21. This compressed air serves as the shock absorber to rapid pressure fluctuations within the water conduit arm, thus preventing water vibration.
As pointed out above, the housing 21 of each spray head 16 is rigidly and immovably secured to the associated conduit section by the adapter 17. Each spray head 16 also consists of a frame 32 which is movable relative to the housing 21 in three respects which are described below. Frame 32 consists of a normally vertical upright member 33 having three spaced horizontal projections 34-36. The projections 34, 35 serve as the movable interconnection between the frame 32 and housing 21, as best shown in FIGS. 5, 7 and 8. As particularly shown in FIG. 7, projection 35 terminates in a collar 35a which completely encircles the nozzle member 24, but which is slightly elongated in its inner dimension to permit a limited amount of movement. Similarly, projection 34 terminates in a collar 34a which completely encircles the extreme lower end of the housing 21, but is even more elongated in its inner dimension to permit a greater degree of movement of the frame 32 relative to the housing 21. The collars 34a, 35a are in essential alignment with the vertical axis of the housing 21. As particularly shown in FIG. 5, collar 35a rests on and is supported by the extreme top of housing 21, and the materials from which these respective components are formed permit a low friction, bearing relationship so that the frame 32 may easily be rotated about the vertical axis of the housing 21. Further, by reason of the elongated inner dimension of the collars 34a, 35a, the movable frame may be tipped on the order of 10°-15° (see the broken line representation of FIG. 3), such tipping movement occurring relative to the bearing engagement of the collar 35a relative to the top of housing 21. As such, the tipping movement is essentially rotated about a horizontal axis passing through or proximate the top of housing 21. It will be appreciated that this horizontal tipping axis could be more precisely defined were the frame 32 to be pivotally pinned relative to the housing 21. However, I prefer the described structure because of its simplicity and economy of manufacture.
With specific reference to FIGS. 3-6 and 9, the projection 36 terminates in a bearing member 36a having an irregularly shaped bearing passage which slidably receives a shaft 37 of similar cross sectional shape. The irregular configuration, which is a segment of a circle (FIG. 4) enables the shaft to slide up and down vertically, while at the same time precluding rotation of the shaft 37 within the bearing 36a.
A spray deflector 38 is integrally formed at the bottom of shaft 37, and disposed in overlying relationship to the nozzle member 34. Deflector 38 is circular in shape in the preferred embodiment, including a central recess 38a and a plurality of radially disposed vanes 38b. As shown in FIG. 9, the vanes 38b are disposed in the plane of the recess 38a, and thus cause water received from the nozzle member 24 to be deflected radially outward into a spray pattern of predetermined configuration. As shown in FIG. 4, the pattern extends circumferentially on the order of 180°; the thickened portion of deflector 38 immediately rearward of the recess 38a (FIG. 9) precluding a spray pattern of greater angular circumference. The angular position of the spray deflector 38 relative to the movable frame 32 causes the resulting spray pattern to be directed away from the frame 32, as shown in FIG. 4, so that there is no interference by the frame with the spray.
Shaft 37 is sufficiently long to permit the spray deflector 38 to drop by gravity to a position engageably covering the nozzle 24 (FIG. 5) when the device is not in operation (i.e., when there is no water pressure). This particular feature prevents dirt, insects and other matter from entering the nozzle 24 during period of nonuse, and subsequently clogging the output of the device. Normal operating water pressure will force the spray deflector 38 upward into the position shown in FIG. 6, and it will be maintained in this operating position as long as the water jet from nozzle 24 continues.
Movable frame 32 includes a tail or rudder member 41 of general triangular configuration which extends rearwardly from the vertical member 33. As shown in FIG. 4, tail member 41 is uniformly thin in cross section, and it is disposed in a vertical plane which bisects the spray pattern created by deflector 38. As constructed, the tail member 41 causes the movable frame 32 to act as a weather vane, sensing the wind direction and pointing the spray deflector 38 directly into the wind. This of course insures that virtually all of the water emanating from the spray pattern falls on the annular area directly below the spray head 16 in question, rather than being blown by the wind onto another area or away from the field entirely.
With continued reference to FIGS. 1 and 2, a pair of generally triangularly shaped ailerons 42 project laterally from the angular trailing edge of trail member 41. As shown, the greatest lateral dimension of the ailerons 42 is near the bottom of the tail member 41, and this lateral dimension decreases in the upward direction. As constructed and disposed, the ailerons 42 are always exposed to a horizontal force component of the wind, and the size of the areas which they expose is chosen to permit a wind of sufficient velocity to tip the movable frame 32 into the broken line position shown in FIG. 3. Thus, under strong wind conditions, the spray pattern of deflector 38 not only is directed into the wind, but it is also directed angularly downward to prevent the spray from being blow away.
The particular construction of the deflector 38 also helps in this regard, since it is designed to create a spray of water droplets that are large enough to resist being blow off course by the wind, as is the case with a fine spray mist, but not so large as to damage the crop or the field.
Preferably, the irrigation system 11 is custom designed to the field through the appropriate selection of spray heads 16 to accomplish the objective of uniform water distribution in the proper amount. As pointed out above, the water distributing capacity of the spray heads 16 generally increases as a function of radial distance from the center pivot. However, this is not necessarily a linear relationship. For example, if the field to be irrigated includes areas of appreciable difference in elevation, it may be desired to provide spray heads 16 capable of delivering greater volumes of water in the higher areas, and spray heads 16 capable of delivering lesser volumes of water for the lower areas. This of course would take into account the anticipated water run off from the higher to lower areas.
Uniform construction and component interchangeability of the spray heads 16 is advantageous in this regard. It will be appreciated that the water distributing capacity of a spray head 16 is determined by the size of passage 31a in the resilient washer 31, as well as the inner diameter of nozzle 24. Both of these components are readily interchangeable to obtain the desired water distributing capacity. If further changes are necessary, it is also possible to interchange the cover portion 23 having an outlet of lesser size.
In operation, water is supplied to the irrigation system 11 at the center pivot 13 at approximately 20 psi. The system is designed for a minimal pressure drop from the center to the outermost point in the conduit arm with the system on flat ground. Stated otherwise, essentially uniform pressure appears at each of the spray heads 16 where there is no difference in elevation over the length of the conduit arm. Thus, when differences in elevation appear, such as between the towers 14a and 14f of FIG. 1, the resilient washer 31 of each spray head 16 will deform appropriately to maintain a constant volume of water from the nozzle 24. This insures that the proper amount of water falls on the annular area which a particular spray head 16 overlies. The spray heads 16 always face into the wind due to tail member 41, to insure that all water falls on the associated annular area; and the ailerons 42 cause the device to tip angularly downward under strong wind conditions to prevent the spray from blowing away.
FIGS. 10-12 disclose an alternative embodiment of the resilient washer, the modified form being generally designated 131. With respect to unmodified structure, like numerals represent the respective components.
Resilient washer 131 is designed to permit a greater flow of water in its undeformed state through the provision of auxiliary flow passages. To this end, resilient washer 131 is constructed to be essentially flat in its undeformed state, presenting a flat inlet surface 131a to the incoming water. The outlet face 131b, however, takes the form of a shallow conical recess capable of being deformed into engagement with the associated nozzle member 24. A passage 132, having a uniform cross section in the undeformed state, connects the surfaces 131a, 131b.
As best shown in FIG. 11, the outside diameter of resilient washer 131 is slightly less than the inside diameter of cylindrical member 25, thus creating an annular space 133 therebetween. The washer 131 is maintained in a centered position through the inclusion of three identical legs 134, which are equiangularly spaced on its outer peripheral face and integrally formed therewith. As shown in FIGS. 10 and 12, each of the legs 134 has an axial dimension slightly greater than the thickness of the washer 131, which causes the washer 131 to be axially spaced from the flange 24a as indicated by the reference numeral 135.
The thickness of the legs 134 is chosen so that the resilient washer 131 is frictionally retained within the cylindrical member 25. Alternatively, a retaining ring 28 could be used, although it would have to be circumferentially discontinuous to permit the passage of water in the annular space 133.
As constructed, with the resilient washer 131 in its undeformed state, water passes not only through the passage 132, but also through the annular space 133 and axial space 135 to increase the overall volume. This of course occurs when water pressure in the conduit arm has been decreased and the output volume needs to be maintained constant or increased. As water pressure increases, the resilient washer 131 deforms, thus changing the size of the passage 132 and, as a result, maintaining the volume constant. When water pressure builds up sufficiently, the conical surface 131b begins to engage the flange 24a, thus cutting off the auxiliary volume through the annular space 133. Operation of the device and system is otherwise the same.
FIGS. 13-15 disclose an alternative embodiment of portions of the sprinkler head which accomplish auxiliary flow in the low pressure state in a different manner. With respect to unmodified structure in FIGS. 13-15, the same numerals appearing in previous embodiments are again used, with the modified structure bearing new reference numerals.
The overall device, which bears the general reference numeral 141, includes an upright housing 21, of which the lower bowl portion 22 is the same. Housing 21 includes a modified upper or cover portion 142 which is threadably received by the lower portion 22 in sealed relation as in other embodiments. However, the cover 142 does not include an integrally formed cylindrical member 25. Rather, a separate cylindrical member 143 is provided which serves to establish a controlled auxiliary flow under low pressure conditions. The upper portion of auxiliary flow member 143 defines a nozzle member 143a and the lower cylindrical portion 143b serves to house a resilient washer 31. The auxiliary flow member 143 is constructed for interchangeability, with the outer diameter of the nozzle 143a corresponding to the inside diameter of the housing outlet opening to permit a press fit. As shown in FIGS. 9 and 10, the outer top surface of the lower cylindrical portion 143b abuts the inside bottom surface of the cover portion 142, and the inner top surface, which is annular in shape, defines a control surface with which the washer 41 cooperates.
With additional reference to FIG. 15, the lower cylindrical portion 143b has formed therein a pair of auxiliary flow channels 143c which are generally semicircular in cross section and diametrically opposed. Each of the flow channels 143c comprises a shallow groove which extends axially upward on the inner face of the cylindrical portion 143b, and then radially inward to a "blind" or dead end position on the control surface before it reaches the outlet of the nozzle 143a. As will become apparent, it is essential that the auxiliary flow channels 143c extend radially inward to some degree, although the distance may vary with the particular application.
The resilient washer 31 is frictionally received by the inner surface of the lower cylindrical portion 143b, as shown in FIGS. 13 and 14. FIG. 13 depicts the sprinkler head 141 in a low pressure operating state, in which the magnitude of water pressure entering the device is incapable of flexing the resilient washer 31. Consequently, the washer 31 remains in its unflexed or unstressed state, with the opening therethrough remaining of constant diameter to pass the maximum volume of water. The auxiliary flow channels 143c increase the volume of water passing through the nozzle outlet in this low pressure operating state by creating a bypass flow around the resilient washer 31.
This auxiliary flow continues as long as the water pressure continues to be low. As soon as water pressure increases, the resilient washer 31 begins to flex toward face engagement with the inside top surface of the lower cylindrical portion 143b. Thus, as the control passage of the resilient washer 31 becomes more restrictive, as shown in FIG. 14, the washer 31 itself also progressively decreases the bypass flow through the auxiliary channels 143c until it reaches its flattened position as shown in FIG. 14. In this position, the upper face of the washer 31 fully engages the inside top control surface of the auxiliary flow member 143, thus completely terminating the bypass flow.
The annular area between the cylindrical member 143 and the housing 21 retains a pocket of air for shock absorbing purposes in the same manner as the previously described embodiments.
FIGS. 16 and 17 disclose an alternative embodiment of the auxiliary flow member, which is represented generally by the numeral 151. The sole difference with the auxiliary flow member 141 resides in the inclusion of eight auxiliary passages 151c rather than two such passages. The auxiliary passages 151c are equiangularly spaced to provide uniform, balanced flow. The increased number of passages increases the volume of water passing through the nozzle outlet with the sprinkler head operating at minimum pressure.
FIGS. 18 and 19 disclose a further alternative embodiment of the auxiliary flow member, which is represented generally by the numeral 161. This device includes four equiangularly spaced auxiliary passages 161c each of which has a circumferential width greater than its radial depth, and thus has a greater flow capacity than one of the passages 151c. The passages 161c also extend axially upward along the inner cylindrical surface of member 161, thereafter tapering radially inward in a "blind" end.
It will be appreciated that interchangeability of the auxiliary flow members 141, 151, 161 permits selection appropriate to the volume of auxiliary flow required. Thus, for a particular agricultural field, an irrigation system can be custom designed through appropriate selection of the auxiliary flow devices.
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The disclosure is directed to a center pivot irrigation system capable of operation under high or low water pressure and a constant volume sprinkler head therefor, which together provide uniform water distribution over an agricultural field notwithstanding the presence of hills and valleys in the field, pressure fluctuations of the water source, friction losses or the direction or magnitude of the wind. The system employs a plurality of sprinkler heads each of which provides a constant volume of water to the annular area over which it travels. Because the annular areas increase in size and total water requirements with increasing distance from the center pivot, the water delivering capacity of each sprinkler head is chosen as a direct function of its radial distance from the center pivot, thus insuring the same water distribution to all points on the field. Each sprinkler head is designed to produce a spray pattern that extends laterally outward with a predetermined directional orientation. A vertical tail or rudder associated with the sprinkler head acts in weather vane fashion to direct the directional spray pattern into the wind at all times, thus preventing the water spray from being blown from its intended area, which results in nonuniform distribution. The sprinkler heads are also constructed for tipping relative to a vertical axis, and ailerons extending laterally from the rudder act to tip the head and spray pattern downward to a degree in the face of particularly strong winds, thus insuring that the water reaches its destination.
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TECHNICAL FIELD
The present disclosure relates to the mining arts, and more particularly, to an apparatus for removing debris in conjunction with a roof drilling apparatus in a mine.
BACKGROUND OF THE INVENTION
Most earth drilling systems employ some form of rotary or percussion powered drills. Typically, a drilling machine, such as for forming a hole for an explosive charge, or for anchoring a roof bolt, includes a drill socket for receiving a stem with a drill bit on the distal down hole section thereof. The stem/bit on a rotary drill machine is rotated by a shaft, sometimes called a spinner, mounted on a drill head to form the drill hole. The rotary driving motion of the spinner is usually hydraulically or pneumatically driven.
Various types of drilling systems utilize a drilling fluid in combination with a drilling tool. This drilling fluid may be a liquid such as water or a water-containing liquid. The uses of a drilling fluid may include assisting in removing drill cuttings from a borehole, stabilizing borehole walls to prevent caving, controlling dust produced during the drilling process, and cooling and cleaning the drill bit. Such use of a drilling tool with a drilling fluid may be termed wet-drilling.
As can be seen in FIG. 1 , wet-drilling generally involves the introduction of the drilling fluid into a borehole in a surface to be drilled, such as through a channel within the drill bit. As the drilling fluid is introduced into the borehole, the fluid cools the cutting edge of the drill bit and flush away the dust and cuttings within the borehole. The combination of fluid and cuttings is generally forced out of the borehole through an annulus between the drill bit and the borehole. By flushing away the cuttings, the longevity of the drill bit may be extended because the drill bit is not forced to continuously re-cut the cuttings within the borehole. By reducing or eliminating the dust created during the drilling process, the air quality in the mine may be greatly improved.
In the case of overhead drilling, such as in the drilling in the roof of a mine shaft, the amount of drilling fluid used may be increased in comparison to a horizontally drilled borehole. This additional fluid may be necessary to maintain the advantages of wet-drilling, as gravity forces the fluid out of the overhead borehole more quickly than a horizontal borehole. As gravity forces the combination of fluid, dust, and cuttings (i.e. the waste fluid) down the shaft of the drill bit, the spinning of the drill, especially at the drill head, may cause this waste fluid to be rapidly and somewhat violently dispersed in the mine shaft in the area of the drill. This dispersed waste fluid deleteriously accumulates in the mine and makes for unpleasant working conditions.
Accordingly, a need is identified for an apparatus that provides an improvement in wet-drilling overhead boreholes within a mine.
SUMMARY
One aspect of the disclosure is an apparatus for use in wet drilling a face of a mine passage with a fluid. The apparatus includes a drill head for drilling the face using the fluid and a pump associated with the drill head for collecting used fluid and for directing fluid away from the drill head. In one embodiment the pump is a centrifugal pump. In another embodiment, the apparatus further includes an impeller for inducing flow of the fluid in an exiting direction which is generally perpendicular to an entering direction.
The drill head and the pump may each include an opening for receiving a drilling member for drilling the face of the mine passage. The pump may be attached to the drill head such that the opening in the drill head is coaxial with the opening of the pump.
In another embodiment, the pump includes a housing forming a chamber surrounding an impeller. The housing may include an inlet and an outlet. The inlet may include a frustoconical collar for directing fluid into the pump.
Another aspect of the disclosure relates to an apparatus for use with a drilling shaft in wet-drilling a face of a mine passage with a liquid. The apparatus includes a drill head for powering the drilling shaft for drilling the face in connection with the liquid and a centrifugal pump adapted for collecting used liquid and for directing said fluid away from the drill head.
In one embodiment, the pump includes an impeller. The impeller may comprise an annular disc having a plurality of curved blades for displacing the liquid.
In another embodiment, the apparatus further includes a first motor for driving the drilling shaft. The first motor may also drive the centrifugal pump. Alternately, the apparatus may include a second motor for driving the centrifugal pump.
An additional embodiment further includes a pump housing, wherein the housing comprises an inlet concentric with the drilling shaft and an outlet. The inlet may further include a grate.
In a further embodiment, the drill head and centrifugal pump may each include an aperture for receiving the drilling shaft, and the apertures may be aligned concentrically.
A further aspect of the disclosure relates to a method of wet drilling a face of a mine passage. The method includes the steps of drilling a borehole into the face of the mine passage using a drilling liquid and collecting the used liquid from the drilling step. The method may further include the step of recirculating the used liquid for reuse as the drilling liquid. This may include the step of removing debris from the used liquid.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 illustrates a prior art drill for use in wet-drilling;
FIG. 2 a is a perspective view of a drill apparatus according to one aspect of the disclosure;
FIG. 2 b is a side elevational view of the apparatus;
FIG. 3 is an exploded view of a pump associated with the apparatus;
FIG. 4 is a top plan view of the pump of the above embodiment;
FIG. 5 is a schematic of an embodiment of the drill apparatus in use with a recirculating system;
FIG. 6 is a cross-sectional view of the pump of FIG. 4 through the line 6 - 6 ;
FIG. 7 is a front elevational view of one embodiment of the apparatus.
DETAILED DESCRIPTION
One embodiment of the present invention relates to an apparatus 10 for collecting and disposing of fluid in association with a drilling tool used in combination with a drilling fluid, such as a wet drilling tool in a wet-drilling environment. The apparatus 10 may be used in conjunction with the drilling of a face 20 of a mine passage with the use of a drilling fluid F. The drilling fluid F may be a liquid such as water or a water-containing fluid.
As can be seen in FIG. 2 a , the apparatus 10 may include a drill head 12 for rotating and driving a drill shaft 16 and drill bit (not pictured). In the wet-drilling embodiment, the drilling fluid F may be introduced to the mine face 20 or borehole through a passage within the drill shaft 16 (see FIG. 2 b ). As the fluid F enters an overhead borehole and collects the dust and cuttings within the borehole, it exits the borehole as waste W. This waste W may follow a generally downward path along the drill shaft 16 .
The drill head 12 may also be used in association with a pump 14 to collect this waste W. The pump 14 may be aligned with the drill head 12 along a longitudinal axis of the drill shaft 16 . In that manner, the pump 14 may recover the waste W from the borehole and divert the waste to a desired location. The pump 14 may be attached to a portion of the drill head 12 such that the pump 14 lies between the borehole and the drill head 12 during use.
The pump 14 may be any pump capable of transporting the waste W from one location to another, such as a centrifugal pump. As shown in more detail in FIG. 3 , the pump 14 may include a collar 22 for collecting waste W. The collar 22 may be of a frustoconical shape, with a wide annulus facing upward, and a smaller, concentric annulus associated with the body of the pump 14 . In practice, this collar 22 is adapted to collect and divert waste W to the pump.
The pump 14 may include a housing 24 for receiving the waste W collected by the collar 22 . The housing 24 is sealed with a pump cover 32 , which may include a central cover aperture 34 through which the drilling shaft 16 may pass. The pump cover 32 may further include one or more cover openings 38 for allowing waste W to enter the pump 14 . These openings may include a mesh or filter to prevent large pieces of cuttings from entering and possibly clogging the pump. In one embodiment, the pump cover 32 includes a plurality of cover openings 38 forming a grate 39 , wherein the cover openings 38 are dimensioned so as to prevent large particles from entering the pump. These cover openings 38 are located within the smaller annulus of the collar 22 .
Within the housing 24 , the pump 14 may further include an impeller 26 for directing the waste W to an outlet 28 . The impeller 26 may take any shape capable of diverting the waste to the outlet, but is shown in the shape of an annular disc with one or more curved blades 36 . The impeller 26 of a centrifugal pump is configured to direct fluid entering the top of the pump in a perpendicular direction, toward an outer wall of the housing 24 .
The impeller further includes a central aperture 30 through which the drill shaft 16 may pass. The central cover aperture 34 may align with the central aperture 30 of the impeller 26 . The drill shaft 16 may pass through the concentrically aligned central aperture 30 of the impeller 26 and cover aperture 34 , as well as the collar 22 . In this way, the drill head 12 may drive the drill shaft 16 through the pump 14 . The pump 14 , therefore, is positioned between the drill head 12 and the borehole during use.
As can be seen in FIG. 4 , the pump 14 is generally circular in shape, and the housing 24 may include an outwardly spiraling extended portion 40 for directing waste W to the outlet 28 . The outlet 28 may further include a port fitting 42 for connecting the outlet 28 to a tube or hose (not shown) for transporting the waste W from the pump 14 to a desired location.
In one embodiment, the waste W may be recirculated subsequent to collection so as to be reused as a drilling fluid F. As illustrated in FIG. 5 , drilling fluid F may be supplied to the drill head 12 from a fluid source 52 . The fluid F is then utilized in a wet-drilling process as described above. The waste W may be collected by the pump 14 , and then may be diverted to a collector 54 , wherein debris from the waste W may be removed. This collector 54 may comprise any mechanism capable of removing debris and/or sediment from the waste W, such as a filter, a settling tank, a centrifuge, or the like. Once the debris and/or sediment has been removed from the waste W, the cleaned fluid portion of the waste may be reused as drilling fluid F. This fluid F may be delivered from the collector 54 to the fluid source 52 in order to be reused within the drilling process. The transfer of fluid within this embodiment may be accomplished via gravity, or any number of pumps (not shown) associated with the various system components.
FIG. 6 illustrates a cross-sectional view of the pump 14 and drill head 12 as viewed through line 6 - 6 of FIG. 4 . The drill head 12 includes a driver 44 for rotating and driving the drill shaft 16 . In one embodiment, the drill head 12 further includes a driving extension 46 in communication with the driver 44 for driving the impeller 26 . The driving extension 46 may engage an underside of the impeller within the housing 24 through one or more connectors 48 . These connectors 48 may be in the form of a screw, bolt, or any other fitment for holding the impeller 26 and driving extension 46 in relative contact for coordinated movement.
The driver 44 of the drill head 12 may be configured for simultaneously driving both the drill shaft and the impeller 26 . In such an embodiment, the impeller 26 may further include an extension 50 dimensioned for contacting the housing 24 so as to seal an internal volume of the housing 24 from the driver 44 and the drive extension 46 . In an alternate embodiment as shown in FIG. 7 , the pump 14 may include a motor M for driving the impeller 26 independently of the drill head 12 .
The foregoing descriptions of various embodiments are provided for purposes of illustration and not intended to be exhaustive or limiting. Modifications or variations are also possible in light of the above teachings. The embodiments described above were chosen to provide the best application to thereby enable one of ordinary skill in the art to utilize the disclosed embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the claimed inventions.
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A pump collects waste fluid and debris from the drilling of a borehole in a mine and for disposing of the waste fluid in a controlled manner. The pump collects the waste fluid into the pump housing through a grate. The pump also includes a centrally located hole which allows a drilling shaft to pass through the body of the pump. The pump further includes a funnel-shaped collar for collecting waste fluid that is dispersed from the mine borehole. A drill head may be attached to the pump for powering the drilling shaft, and for powering an impeller within the pump.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from Swedish Patent Application No. 0004244-0, filed Nov. 20, 2000, and U.S. Provisional Patent Application Serial No. 60/253,702, filed Nov. 28, 2000. These applications are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to novel compounds, to pharmaceutical compositions comprising the compounds, to processes for their preparation, as well as to the use of the compounds for the preparation of a medicament which particularly acts on the central nervous system.
BACKGROUND OF THE INVENTION
[0003] Many diseases of the central nervous system are influenced by the adrenergic, the dopaminergic, and the serotonergic neurotransmitter systems. For example, serotonin has been implicated in a number of diseases and conditions which originate in the central nervous system. A number of pharmacological and genetic experiments involving receptors for serotonin strongly implicate the 5-HT 2c receptor subtype in the regulation of food intake (Obes. Res. 1995, 3, Suppl. 4, 449S-462S). The 5-HT 2c receptor subtype is transcribed and expressed in hypothalamic structures associated with appetite regulation. It has been demonstrated that the 5-HT 2c receptor agonist m-chlorophenylpiperazine (mCPP), which has some preference for the 5-HT 2c receptor, reduces food intake in mice that express the normal 5-HT 2c receptor while the compound lacks activity in mice expressing the mutated inactive form of the 5-HT 2c receptor (Nature 1995, 374, 542-546). In a recent clinical study, a slight but sustained reduction in body weight was obtained after 2 weeks of treatment with mCPP in obese subjects (Psychopharmacology 1997, 133, 309-312). Recently, a series of pyrrolo[3,2,1-ij]quinoline derivatives was identified to be 5-HT 2C receptor agonists having selectivity over the 5-HT 2A receptor (Isaac M., et al., Bioorg. Med. Chem. Lett. 2000, 10, 919-921). The compounds are said to offer a novel approach to the treatment of obesity and epilepsy.
[0004] Weight reduction has also been reported from clinical studies with other “serotonergic” agents (see, e.g., IDrugs 1998, 1, 456-470). For example, the 5-HT reuptake inhibitor fluoxetine and the 5-HT releasing agent/reuptake inhibitor dexfenfluramine have exhibited weight reduction in controlled studies. However, currently available drugs that increase serotonergic transmission appear to have only a moderate and, in some cases, transient effects on the body weight.
[0005] The 5-HT 2c receptor subtype has also been suggested to be involved in CNS disorders such as depression and anxiety (Exp. Opin. Invest. Drugs 1998, 7, 1587-1599; IDrugs 1999, 2, 109-120).
[0006] The 5-HT 2c receptor subtype has further been suggested to be involved in urinary disorders such as urinary incontinence (IDrugs 1999, 2, 109-120).
[0007] Compounds which have a selective effect on the 5-HT 2c receptor may therefore have a therapeutic potential in the treatment of disorders like those mentioned above. Of course, selectivity also reduces the potential for adverse effects mediated by other serotonin receptors.
INFORMATION DISCLOSURE
[0008] U.S. Pat. No. 3,253,989 discloses the use of mCPP as an anorectic agent.
[0009] EP-A1-863 136 discloses azetidine and pyrrolidine derivatives which are selective 5-HT 2c receptor agonists having antidepressant activity and which can be used for treating or preventing serotonin-related diseases, including eating disorders and anxiety.
[0010] EP-A-657 426 discloses tricyclic pyrrole derivatives having activity on the 5-HT 2c receptor and which inter alia may be used for treating eating disorders.
[0011] EP-A-655 440 discloses 1-aminoethylindoles having activity on the 5-HT 2c receptor and which may be used for treating eating disorders.
[0012] EP-A-572 863 discloses pyrazinoindoles having activity on the 5-HT 2c receptor and which may be used for treating eating disorders.
[0013] J. Med. Chem. 1978, 21, 536-542 and U.S. Pat. No. 4,081,542 disclose a series of piperazinylpyrazines having central serotonin-mimetic activity.
[0014] J. Med. Chem. 1981, 24, 93-101 discloses a series of piperazinylquinoxalines with central serotoninmimetic activity.
[0015] WO 00/12475 discloses indoline derivatives as 5-HT 2b and/or 5-HT 2c receptor ligands, especially for the treatment of obesity.
[0016] WO 00/12510 discloses pyrroloindoles, pyridoindoles and azepinoindoles as 5-HT 2c receptor agonists, particluarly for the treatment of obesity.
[0017] WO 00/12482 discloses indazole derivatives as selective, directly active 5-HT 2c receptor ligands, preferably 5-HT 2c receptor agonists, particularly for use as anti-obesity agents.
[0018] WO 00/12502 discloses pyrroloquinolines as 5-HT 2c receptor agonists, particularly for use as anti-obesity agents.
[0019] WO 00/35922 discloses 2,3,4,4α-tetrahydro-1H-pyrazino[1,2-α]quinoxalin-5(6H)ones as 5HT 2c agonists, which may be used for the treatment of obesity.
[0020] WO 00/44737 discloses aminoalkylbenzofurans as 5-HT 2c agonists, which may be used for the treatment of obesity.
[0021] Further compounds reported to be 5HT 2c receptor agonists are, for example, indazolylpropylamines of the type described in WO 00/12481; indazoles of the type described in WO 00/17170; piperazinylpyrazines of the type described in WO 00/76984; heterocycle fused γ-carbolines of the type described in WO 00/77001, WO 00/77002 and WO 00/77010; benzofurylpiperazines of the type described in WO 01/09111 and WO 01/09123; benzofurans of the type described in WO 01/09122; benzothiophenes of the type described in 01/09126; aminoalkylindazoles of the type described in WO 98/30548; indoles of the type described in WO 01/12603; indolines of the type described in WO 01/12602; pyrazino(aza)indoles of the type described in WO 00/44753 and tricyclic pyrroles or pyrazoles of the type described in WO 98/56768.
[0022] GB-B-1,457,005 discloses 1-piperazinyl-2-[2-(phenyl)ethenyl]-quinoxaline derivatives which exhibit anti-inflammatory activity.
[0023] Chem. Pharm. Bull. 1993, 41(10) 1832-1841 discloses 5-HT 3 antagonists including 2-(4-methyl-1-piperazinyl)-4-phenoxyquinoxaline.
[0024] GB-B-1,440,722 discloses 2-(1′-piperazinyl)-quinoxaline compounds having pharmaceutical activity against depression.
[0025] WO 96/11920 discloses CNS-active pyridinylurea derivatives.
[0026] WO 95/01976 discloses indoline derivatives active as 5-HT 2c antagonists and of potential use in the treatment of CNS disorders.
[0027] WO 97/14689 discloses arylpiperazine cyclic amine derivatives, which are selective 5-HT 1d receptor antagonists.
[0028] WO 98/42692 discloses piperazines derived from cyclic amines, which are selective antagonists of human 5-HT 1a , 5-HT 1d and 5-HT 1b receptors.
[0029] GB-B-1,465,946 discloses substituted pyridazinyl, pyrimidinyl and pyridyl compounds which are active as β-receptor blocking agents.
[0030] EP-A-711757 discloses [3-(4-phenyl-piperazin-1-yl)propylamino]-pyridine, pyrimidine and benzene derivatives as α-adrenoceptor antagonists.
[0031] WO 99/03833 discloses arylpiperazine derivatives, which are 5-HT 2 antagonists and 5-HT 1a receptor agonists and therefore are useful as remedies or preventives for psychoneurosis.
[0032] WO 96/02525 discloses arylpiperazine-derived piperazide derivatives having 5-HT receptor antagonistic activity.
[0033] WO 99/58490 disloses aryl-hydronaphthalen-alkane amines which may effectuate partial or complete blockage of serotonergic 5-HT 2c receptors in an organism.
OBJECT OF THE INVENTION
[0034] It is an object of the present invention to provide new compounds.
[0035] Another object of the invention is a pharmaceutical composition comprising compounds for use in therapy as an active ingredient.
[0036] Finally, an object of the invention is a method of treatment or prophylaxis of a serotonin related disease, especially a disease related to the 5-HT 2c receptor.
SUMMARY OF THE INVENTION
[0037] According to the invention novel compounds of the general formula (I) are provided:
[0038] wherein
[0039] R 1 is hydrogen, C 1 -C 4 -alkyl, C 3-4 -alkenyl, C 1-4 -acyl, C 1-4 -alkoxycarbonyl, 2-hydroxyethyl, 2-cyanoethyl, tetrahydropyran-2-yl, or a nitrogen protecting group;
[0040] R 2 is hydrogen, C 1-4 -alkyl, hydoxymethyl, C 1-4 -alkoxymethyl, or fluoromethyl;
[0041] R 3 and R 4 independently of each other are hydrogen, methyl, C 1-4 -alkyl, aryl, heteroaryl wherein aryl and heteroaryl residues in turn may be substituted in one or more positions independently of each other by halogen, C 1-4 -alkyl, C 1-4 -alkoxy, C 1-4 -alkylthio, C 1-4 -alkylsulphonyl, methanesulphonamido, acetyl, nitro, cyano, hydroxy, trifluoromethyl, trifluoromethoxy, trifluoromethylthio, amino, methylamino, dimethylamino, or acetamido; or
[0042] R 3 and R 4 together with the carbon atoms to which they are bound form a 5- or 6-membered aromatic or heteroaromatic ring, which optionally is independently substituted in one or more positions by halogen, methyl, methoxy, methylthio, methylsulphonyl, nitro, cyano, hydroxy, trifluoromethyl, trifluoromethylthio, amino, methylamino, dimethylamino or acetamido;
[0043] R 5 and R 6 independently of each other are hydrogen, C 1 -C 4 -alkoxy-C 2 -C 4 -alkyl, hydroxy-C 2 -C 4 -alkyl, C 1 -C 6 -alkyl, C 2 -C 6 -acyl, aryl, heteroaryl, aryl-C 1 -C 2 -alkyl, heteroaryl-C 1 -C 2 -alkyl, aryl-C 1 -C 2 -acyl, heteroaryl-C 1 -C 2 -acyl, and wherein any aryl or heteroaryl, alone or as part of another group, may be independently substituted in one or more positions by C 1-4 -alkyl, C 1-4 -alkoxy, C 1-4 -alkylthio, C 2-4 -acyl, C 1-4 -alkylsulphonyl, cyano, nitro, hydroxy, C 2-3 -alkenyl, C 2-3 -alkynyl, fluoromethyl, trifluoromethyl, trifluoromethoxy, halogen, dimethylamino, or methylamino; or
[0044] R 5 and R 6 together with the nitrogen atom to which they are bound form a saturated heterocyclic ring having 4-7 ring members which ring may contain an additional heteroatom and which may be substituted by methyl, oxo or hydroxy;
[0045] R 7 is hydrogen or a substituent selected from halogen, methyl, methoxy, and ethoxy; and
[0046] n=1-3;
[0047] and pharmaceutically acceptable salts, hydrates, geometrical isomers, tautomers, optical isomers, N-oxides and prodrug forms thereof.
[0048] In case the compounds of formula (I) can be in the form of optical isomers, the invention comprises the racemic mixture as well as the individual enantiomers as such.
[0049] In case the compounds of formula (I) contain groups which may exist in tautomeric forms, the invention comprises the tautomeric forms of the compounds as well as mixtures thereof.
[0050] In case the compounds of formula (I) can be in the form of geometrical isomers, the invention comprises the geometrical isomers as well as mixtures thereof.
[0051] In another aspect, this invention provides a method for preparing a compound of this invention. The method includes converting a compound of formula (II):
[0052] to the just-mentioned compound.
[0053] In formula (II), R 3 and R 4 independently of each other are hydrogen, methyl, C 1-4 -alkyl, aryl, heteroaryl wherein aryl and heteroaryl residues in turn may be substituted in one or more positions independently of each other by halogen, C 1-4 -alkyl, C 1-4 -alkoxy, C 1-4 -alkylthio, C 1-4 -alkylsulphonyl, methanesulphonamido, acetyl, nitro, cyano, hydroxy, trifluoromethyl, trifluoromethoxy, trifluoromethylthio, amino, methylamino, dimethylamino or acetamido; or
[0054] R 3 and R 4 together with the carbon atoms to which they are bound form a 5- or 6-membered aromatic or heteroaromatic ring, which may be substituted in one or more positions by halogen, methyl, methoxy, methylthio, methylsulphonyl, nitro, cyano, hydroxy, trifluoromethyl, trifluoromethylthio, amino, methylamino, dimethylamino or acetamido; and
[0055] each of Hal 1 and Hal 2 , independently, is halogen.
[0056] In further another aspect, the invention provides the compounds according to formula (I) above for use in therapy.
[0057] Still another aspect of the invention provides a pharmaceutical composition comprising a compound according to formula (I) above as the active ingredient, preferably together with a pharmaceutically acceptable carrier and, if desired, other pharmacologically active agents.
[0058] In yet another aspect, the invention provides a method for the treatment of a human or animal subject suffering from a serotonin-related disease, particularly 5-HT 2c receptor-related, especially eating disorders, particularly obesity; memory disorders, schizophrenia, mood disorders, anxiety disorders, pain, substance abuse, sexual dysfunctions, epilepsy and urinary disorders.
[0059] Another aspect of the invention provides the use of the compounds according to formula (I) above for the manufacture of a medicament for the treatment of a serotonin-related disease, particularly 5-HT 2c receptor-related, especially eating disorders, particularly obesity; memory disorders; schizophrenia, mood disorders, anxiety disorders, pain, substance abuse, sexual dysfunctions, epilepsy and urinary disorders.
[0060] Finally a method for modulating 5HT 2c receptor function is an aspect of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0061] According to the present invention, a class of novel compounds has been developed which bind to the 5-HT 2c receptor (agonists and antagonists) and which therefore may be used for the treatment of serotonin-related disorders.
[0062] First, the various terms used, separately and in combinations, in the above definition of the compounds having the general formula (I) will be explained.
[0063] By “heteroatom” is meant nitrogen, oxygen, sulphur, and in heteroaromatic rings, also selenium.
[0064] The term “aryl” includes phenyl, 1-naphthyl and 2-naphthyl.
[0065] The term “heteroaryl” includes five- and six-membered heteroaromatic rings such as pyrrole, imidazole, thiophene, furan, selenophene, thiazole, isothiazole, thiadiazole, oxazole, isoxazole, oxadiazole, pyridine, pyrazine, pyrimidine, pyridazine, pyrazole, triazole and tetrazole.
[0066] C 1-6 -alkyl, which may be straight or branched, is preferably C 1-4 -alkyl. Exemplary alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, and isohexyl.
[0067] C 1-4 -alkoxy may be straight or branched. Exemplary alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy and tert-butoxy.
[0068] C 2-4 -alkenyl may be straight or branched. Exemplary alkenyl groups include vinyl, 2-propenyl and 1-methyl-2-propenyl.
[0069] C 1 -C 4 -alkoxy-C 2 -C 4 -alkyl may be straight or branched. Exemplary groups include 2-(methoxy)ethyl, 3-methoxy-1-propyl, 4-ethoxy-1-butyl and the like.
[0070] Exemplary aryl-C 1 -C 2 -acyl include benzoyl and phenylacetyl. Exemplary heteroaryl-C 1 -C 2 -acyl include nicotinoyl and 3-pyridinylacetyl and the like.
[0071] C 2-4 -acyl may be saturated or unsaturated. Exemplary acyl groups include acetyl, propionyl, butyryl, isobutyryl, and butenoyl (e.g. 3-butenoyl).
[0072] Halogen includes fluorine, chlorine and bromine.
[0073] Where it is stated above that aryl and heteroaryl residues may be substituted, this applies to aryl and heteroaryl per se as well as to any combined groups containing aryl or heteroaryl residues, such as heteroaryl-C 1 -C 2 -alkyl and aryl-C 1 -C 2 -acyl.
[0074] The term “N-oxides” means that one or more nitrogen atoms, when present in a compound, are in N-oxide form (N→O).
[0075] The term “prodrug forms” means a pharmacologically acceptable derivative, such as an ester or an amide, which derivative is biotransformed in the body to form the active drug. Reference is made to Goodman and Gilman's, The Pharmacological basis of Therapeutics, 8 th ed., McGraw-Hill, Int. Ed. 1992, “Biotransformation of Drugs, p. 13-15.
[0076] “Pharmaceutically acceptable” means being useful in preparing a pharmaceutical composition that is generally safe, non-toxic and neither biologically nor otherwise undesirable and includes being useful for veterinary use as well as human pharmaceutical use.
[0077] “Pharmaceutically acceptable salts” mean salts which are pharmaceutically acceptable, as defined above, and which possess the desired pharmacological activity. Such salts include acid addition salts formed with organic and inorganic acids, such as hydrogen chloride, hydrogen bromide, hydrogen iodide, sulfuric acid, phosphoric acid, acetic acid, glycolic acid, maleic acid, malonic acid, oxalic acid, toluenesulphonic acid, methanesulphonic acid, fumaric acid, succinic acid, tartaric acid, citric acid, benzoic acid, ascorbic acid, and the like.
[0078] R 1 is preferably hydrogen or methyl. Most preferably R 1 is hydrogen.
[0079] R 1 may also serve as a nitrogen protecting group, and then R 1 is t-butoxycarbonyl (t-BOC), benzyl, or trityl.
[0080] R 2 is preferably hydrogen or methyl (especially in the 2-position of the piperazine ring).
[0081] R 3 and R 4 are preferably (independently) hydrogen, halogen or methyl. When R 3 and R 4 form a ring together with the ring carbons to which they are bound, such a ring is preferably benzene (to give quinoxaline) or thiophene (to give thieno[3,4-b]pyrazine). When substituted, the rings are preferably mono- or disubstituted, preferably by halogen or methyl.
[0082] When R 7 is other than hydrogen it may occupy any available position of the phenyl ring.
[0083] The group —CH 2 N(R 5 )(R 6 ) may be attached to the orto-, meta-, or the para position, relative to the alkylenedioxy side-chain, of the phenyl ring, preferably the meta position.
[0084] n in formula (I) is 1-3 where n is the number of methylene groups. n is preferably 1, having the meaning that the two oxygen atoms in formula (I) are spaced between a —CH 2 CH 2 — group;
[0085] Preferred compounds of the general formula (I) above are:
[0086] 2-(1-Piperazinyl)-3-{2-[3-(4-morpholinylmethyl)phenoxy]ethoxy}pyrazine;
[0087] 2-(1-Piperazinyl)-3-{2-[3-(1-pyrrolidinylmethyl)phenoxy]ethoxy}pyrazine;
[0088] 2-(1-Piperazinyl)-3-{2-[3-(4-methyl-1-piperazinylmethyl)phenoxy]ethoxy}pyrazine;
[0089] 2-(1-Piperazinyl)-3-{2-[3-{(2-methoxyethyl)amino}methyl)phenoxy]ethoxy}pyrazine;
[0090] 2-(1-Piperazinyl)-3-{2-[3-{(isopropylamino)methyl}phenoxy]ethoxy}pyrazine,
[0091] and their pharmacologically acceptable salts and solvates.
[0092] In another aspect, this invention relates to compounds of any of the formulae herein and their use as delineated herein, wherein R 5 and R 6 together with the nitrogen atom to which they are bound form a saturated heterocylic ring having 4-7 ring members, and which may contain an additional heteratom. Exemplary rings are azetidine, pyrrolidine, piperazine, homopiperazine, morpholine, thiomorpholine, or piperidine. The saturated heterocyclic ring may be substituted by methyl, oxo, or hydroxy.
[0093] As mentioned above, the compounds of the present invention are useful for the treatment (including prophylactic treatment) of serotonin-related disorders, especially 5-HT 2c receptor-related, in a human being or in an animal (including e.g. pets), such as eating disorders, especially obesity; memory disorders, such as Alzheimer's disease; schizophrenia; mood disorders, including, but not restricted to, major depression and bipolar depression, including both mild and manic bipolar disorder, seasonal affective disorder (SAD); anxiety disorders, including situational anxiety, generalised anxiety disorder, primary anxiety disorders (panic disorders, phobias, obsessive-compulsive disorders, and post-traumatic stress disorders), and secondary anxiety disorders (for example anxiety associated with substance abuse); pain; substance abuse; sexual dysfunctions; epilepsy and urinary disorders, such as urinary incontinence.
[0094] The compounds of the present invention in radiolabeled form, may be used as a diagnostic agent.
[0095] The compounds of the general formula (I) above may be prepared by a method of this invention, or by, in analogy with, a conventional method. This invention relates to methods of making compounds of any formulae herein comprising reacting any one or more of the compounds or formulae delineated herein including any processes delineated herein.
[0096] For example, as shown in Scheme 1, a compound of formula (I) may be prepared by first treating a compound of formula (II), wherein Hal is halogen and R 3 and R 4 are as defined above, with an appropriate piperazine of formula (III), wherein R 1 and R 2 have the same meaning as in formula (I) and where R 1 may be a suitable nitrogen protecting group, such as trityl, benzyl or tert-butoxycarbonyl, to provide a compound of formula (IV). The reaction is carried out in a solvent, such as, acetonitrile, dioxane, tetrahydrofuran (THF), n-butanol, N,N-dimethylformamide (DMF), or in a mixture of solvents such as DMF/dioxane, optionally in the presence of a base, such as K 2 CO 3 , Na 2 CO 3 , Cs 2 CO 3 , NaOH, triethylamine, pyridine, or the like, at 0-200° C. for 1-24 hours.
[0097] The compound of formula (IV) is reacted with a diol of formula (V), wherein n has the same meaning as in formula (I), to provide intermediate (VI). The reaction is carried out in a solvent, such as, dioxane, THF, DMF or pyridine, and the like, in the presence of a base such as K-t-BuO, Na-t-BuO, NaH, or the like, at 0-150° C. for 1-24 hours.
[0098] Intermediate (VI) is reacted with a hydroxybenzaldehyde compound of formula (VII), wherein R 7 has the same meaning as in formula (I), to provide the aldehyde intermediate (VIII). The reaction may be carried out in the presence of diethyl azodicarboxylate (DEAD) or 1,1′-azobis(N,N-dimethylformamide) (cf. Tetrahedron Lett. 1995, 36, 3789-3792), preferably DEAD, and triphenylphosphine (PPh 3 ) in a solvent such as THF or dichloromethane (Mitsunobu reaction; see: Org. React. 1992, 42, 335-656.).
[0099] Subjecting intermediate (VIII) to a standard reductive alkylation procedure (such as described in J. Org. Chem. 1996, 61, 3849-3862), with an appropriate amine of formula (IX), wherein R 5 and R 6 have the same meaning as in formula (I), results in a compound of this invention (I).
[0100] When R 1 in formula (I) is a nitrogen protecting group as defined below, the subsequent N-deprotection may be performed under standard conditions, such as those described in Protective Groups in Organic Synthesis, John Wiley & Sons, 1991, to provide compounds of formula (I) wherein R 1 is hydrogen. Nitrogen protecting groups are known in the art and include those described in T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2d. Ed., John Wiley and Sons (1991) and subsequent editions thereof.
[0101] An obtained compound of formula (I) may be converted to another compound of formula (I) by methods well known in the art.
[0102] The processes described above may be carried out to give a compound of the invention in the form of a free base or as an acid addition salt. A pharmaceutically acceptable acid addition salt may be obtained by dissolving the free base in a suitable organic solvent, such as ether or in a mixture of ether and methanol, and treating the solution with an acid, in accordance with conventional procedures for preparing acid addition salts from base compounds. Examples of addition salt forming acids are maleic acid, fumaric acid, succinic acid, methanesulfonic acid, acetic acid, oxalic acid, benzoic acid, hydrochloric acid, sulphuric acid, phosphoric acid, and the like.
[0103] The compounds of formula (I) may possess one or more chiral carbon atoms, and they may therefore be obtained in the form of optical isomers, e.g., as a pure enantiomer, or as a mixture of enantiomers (racemate) or as a mixture containing diastereomers. The separation of mixtures of optical isomers to obtain pure enantiomers is well known in the art and may, for example, be achieved by fractional crystallization of salts with optically active (chiral) acids or by chromatographic separation on chiral columns.
[0104] In accordance with the present invention, the compounds of formula (I), in the form of free bases or salts with physiologically acceptable acids, can be brought into suitable galenic forms, such as compositions for oral use, for injection, for nasal spray administration or the like, in accordance with accepted pharmaceutical procedures. Such pharmaceutical compositions according to the invention comprise an effective amount of the compounds of formula (I) in association with compatible pharmaceutically acceptable carrier materials, or diluents, as are well known in the art. The carriers may be any inert material, organic or inorganic, suitable for enteral, percutaneous, subcutaneous or parenteral administration, such as: water, gelatin, gum arabicum, lactose, microcrystalline cellulose, starch, sodium starch glycolate, calcium hydrogen phosphate, magnesium stearate, talcum, colloidal silicon dioxide, and the like. Such compositions may also contain other pharmacologically active agents, and conventional additives, such as stabilizers, wetting agents, emulsifiers, flavouring agents, buffers, and the like.
[0105] The compositions according to the invention can e.g. be made up in solid or liquid form for oral administration, such as tablets, pills, capsules, powders, syrups, elixirs, dispersable granules, cachets, suppositories and the like, in the form of sterile solutions, suspensions or emulsions for parenteral administration, sprays, e.g. a nasal spray, transdermal preparations, e.g. patches, and the like.
[0106] As mentioned above, the compounds of the invention may be used for the treatment of serotonin-related disorders in a human being or an animal, such as eating disorders, particularly obesity, memory disorders, schizophrenia, mood disorders, anxiety disorders, pain, substance abuse, sexual dysfunctions, epilepsy and urinary disorders. The dose level and frequency of dosage of the specific compound will vary depending on a variety of factors including the potency of the specific compound employed, the metabolic stability and length of action of that compound, the patient's age, body weight, general health, sex, diet, mode and time of administration, rate of excretion, drug combination, the severity of the condition to be treated, and the patient undergoing therapy. The daily dosage may, for example, range from about 0.001 mg to about 100 mg per kilo of body weight, administered singly or multiply in doses, e.g. from about 0.01 mg to about 25 mg each. Normally, such a dosage is given orally but parenteral administration may also be chosen.
[0107] The specific examples below are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. Without further elaboration, it is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent. All publications cited herein are hereby incorporated by reference in their entirety.
EXAMPLES
[0108] General
[0109] NMR spectra were recorded on a Bruker Advance DPX 400 MHz spectrometer at 25° C. Chemical shifts are given in ppm relative to tetramethylsilane. LC/MS data were obtained using an HP1100 hplc system coupled to a Micromass platform LC mass spectrometer running MassLynx. Details of the hplc are: Column, Phenomenex C18 Luna, 30×46 mm at 40±1° C. Eluant gradient T=0, 95% (0.1% formic acid in water) and 5% (0.1% formic acid in acetonitrile, then a linear gradient to T=2.5 min, 5% (0.1% formic acid in water) and 95% (0.1% formic acid in acetonitrile), then a further 1 min at these conditions. Eluent flow rate was 2 mL/min. Detection was by UV diode array at window 210-400 nm. Alternate +ve and −ve ion APCI mass spectra were collected throughout the 3.5 min, scanning between 100 and 650 mass units. High resolution MS were obtained on a Micromass LCT spectrometer. Developing solvents for TLC on silica were di-isopropylether or ethyl acetate/light petroleum mixtures.
Example 1
2 -(1-Piperazinyl)-3-{2-[3-(4-morpholinylmethyl)phenoxy]ethoxy}pyrazine
Step 1: 2-Chloro-3-(4-tert-butoxycarbonyl-1-piperazinyl)pyrazine
[0110] The title compound was prepared according to the procedure described in WO 00/76984. A mixture of N-Boc-piperazine (11.47 g, 61.5 mmol), K 2 CO 3 (8.5 g, 61 mmol) and 2,3-dichloropyrazine (9.20 g, 61.7 mmol) in acetonitrile (100 mL) was stirred at 100° C. for 40 h. The reaction mixture was concentrated, dissolved in toluene, washed with water, dried (MgSO 4 ), and concentrated. The residue was purified by chromatography on silica gel using toluene/EtOAc (7:3) as eluent to give 18.3 g (100%) of the title product. HRMS m/z calcd for C 13 H 19 N 4 O 2 (M) + 298.1197, found 298.1206.
Step 2: 2-[3-(4-tert-Butoxycarbonyl-1-piperazinyl)-2-pyrazinyloxy]ethanol
[0111] The title compound was prepared according to the procedure described in WO 00/76984. KO-t-Bu (9.92 g, 103 mmol) was added to a mixture of the product obtained in step 1 (18.14 g, 60.7 mmol) and ethylene glycol (25 mL, 448 mmol) in pyridine (125 mL) at 85° C. The reaction mixture was stirred for 15 h and then poured into ice-water and extracted with toluene. The organic phase was dried (MgSO 4 ) and concentrated. The residue was purified by chromatography on silica gel using toluene/EtOAc (1:1) as eluent to give 16.9 g (85%) of the title product. HRMS m/z calcd for C 15 H 24 N 4 O 4 (M) + 324.1798, found 324.1784.
Step 3: tert-Butyl4-{3-[2-(3-formylphenoxy)ethoxy]-2-pyrazinyl}-1-piperazinecarboxylate
[0112] A solution of the compound obtained in step 2 above (1.5 g, 4.7 mmol) in dry tetrahydrofuran (THF; 10 mL) was treated with 3-hydroxybenzaldehyde (0.74 g, 6.06 mmol) and triphenylphosphine (1.59 g, 6.06 mmol). This solution was stirred at room temperature then treated with diethyl azodicarboxylate (0.96 mL, 6.06 mmol) in dry THF (5 mL). After 1 hr, TLC indicated some remaining 2-[3-(4-tert-butoxycarbonyl-1-piperazinyl)-2-pyrazinyloxy]ethanol. The reaction was heated at reflux under nitrogen for 5 h, then left to cool to room temperature overnight. TLC again showed unreacted starter. The mixture was treated with further triphenylphosphine (0.80 g, 3.03 mmol), diethyl azodicarboxylate (0.5 mL, 3.03 mmol) and 3-hydroxybenzaldehyde (0.40 g, 3.03 mmol), then stirred at RT for a further 3 hrs (reaction complete by TLC). The volatiles were removed in vacuo and the residue was purified by flash column on silica gel, eluting with petroleum ether/ethyl acetate (2:1). This furnished 0.33 g (16%) of the title product as a colourless oil. 1 H NMR (CDCl 3 ) δ1.5 (s, 9H); 3.5 (bs, 8H), 4.45 (m, 2H); 4.75 (m, 2H); 7.2 (d, 1H); 7.45 (s, 1H); 7.5 (m, 2H); 7.6 (s, 1H); 7.75 (s, 1H).
Step 4: tert-Butyl4-(3-{2-[3-(4-morpholinylmethyl)phenoxy]ethoxy}-2-pyrazinyl)-1-piperazinecarboxylate
[0113] A stirred solution of the aldehyde from step 3 above (71.2 mg, 0.166 mmol) in 1,2-dichloroethane (5 mL) was treated with morpholine (19 mg, 0.22 mmol), 3 Å molecular sieves and sodium triacetoxyborohydride (52 mg, 0.25 mmol). The mixture was stirred at room temperature for 5 h (TLC monitoring). The solution was filtered and the filtrate was treated with an excess of saturated aqueous sodium bicarbonate. The ether extracts were separated and dried over magnesium sulfate. The mixture was filtered and solvent was removed in vacuo to give 54 mg (65%) of the title product as a yellow oil. Pure by NMR. 1 H NMR (CDCl 3 ) δ1.4 (s, 9H); 2.35 (m, 4H); 3.4 (m, 10H); 3.65 (m, 4H); 4.3 (m, 2H); 4.65 (m, 2H); 6.75 (d, 1H); 6.9 (m, 2H); 7.2 (t, 1H); 7.5 (s, 1H); 7.7 (s, 1H).
Step 5: 2-(1-Piperazinyl)-3-{2-[3-(4-morpholinylmethyl)phenoxy]ethoxy}pyrazine
[0114] The product from step 4 above (54 mg, 0.11 mmol) was dissolved in dry ether (20 mL), stirred at room temperature and treated with hydrogen chloride in ether (˜6 M; 5 mL). The resulting white suspension was stirred for 2 h, then quickly filtered off. The hydrochloride salt (hygroscopic), was dissolved in water and neutralized with sodium carbonate. The free base was extracted into dichloromethane. The organic layers were dried magnesium sulfat, filtered, and concentrated in vacuo to furnish 13 mg (29%) of the title product as a pale yellow oil. LS/MS purity 100%. 1 H NMR (CDCl 3 ) δ1.8 (b, 1H); 2.45 (m, 4H); 2.95 (m, 4H); 3.45 (s, 2H); 3.55 (m, 4H); 3.7 (m, 4H); 4.35 (t, 2H); 4.7 (t, 2H); 6.85 (d,1H); 6.95 (m, 2H); 7.25 (t, 1H); 7.55 (s, 1H); 7.75 (s, 1H).
[0115] The following compounds were prepared analogously from tert-butyl4-{3-[2-(3-formylphenoxy)ethoxy]-2-pyrazinyl}-1-piperazinecarboxylate (obtained in Example 1, Step 3) and the requisite amine.
Example 2
2-(1-Piperazinyl)-3-{2-[3-(1-pyrrolidinylmethyl)phenoxy]ethoxy}pyrazine
[0116] Yield 31%. LS/MS purity 100%. 1 H NMR (CDCl 3 ) δ1.7 (m, 4H); 2.45 (m, 4H); 2.9 (m, 4H); 3.4 (m, 4H); 3.5 (s, 2H); 4.3 (m, 2H); 4.6 (m, 2H); 6.7 (d, 1H); 6.85 (m, 2H); 7.15 (t, 1H); 7.45 (s, 1H); 7.7 (s, 1H).
Example 3
2-(1-Piperazinyl)-3-{2-[3-(4-methyl-1-piperazinylmethyl)phenoxy]ethoxy}pyrazine
[0117] Yield 56%. LS/MS purity 100%. 1 H NMR (CDCl 3 ) δ2.15 (s, 3H); 2.35 (b, 9H); 2.85 (m, 4H); 3.35 (m, 6H); 4.2 (m, 2H); 4.55 (m, 2H); 6.7 (d, 1H); 6.8 (m, 2H); 7.1 (t, 1H); 7.4 (s, 1H); 7.6 (s, 1H).
Example 4
2-(1-Piperazinyl)-3-{2-[3-{(2-methoxyethyl)amino}methyl)phenoxy]ethoxy}pyrazine
[0118] Yield 37%. LS/MS purity 100%. 1 H NMR (CDCl 3 ) δ2.8 (t, 2H); 3.05 (m, 6H); 3.35 (s, 3H); 3.6 (m, 6H); 3.8 (s, 2H); 4.35 (m, 2H); 4.7 (m, 2H); 6.8 (d, 1H); 6.95 (d, 2H); 7.25 (t, 1H); 7.55 (s, 1H); 7.8 (s, 1H).
Example 5
2-(1-Piperazinyl)-3-{2-[3-{(isopropylamino)methyl}phenoxy]ethoxy}pyrazine
[0119] Yield 60%. LS/MS purity 100%. 1 H NMR (CDCl 3 ) δ1.1 (d, 6H); 1.85 (b, 1H); 2.85 (m, 1H); 3.0 (m, 4H); 3.5 (m, 4H); 3.8 (s, 2H); 4.35 (m, 2H); 4.7 (m, 2H); 6.8 (d, 1H); 6.9 (m, 2H); 7.2 (t, 1H); 7.5 (s, 1H); 7.75 (s, 1H).
Example 6
2-(1-Piperazinyl)-3-{2-[3-{(3-methoxyphenylamino)methyl}phenoxy]ethoxy}pyrazine
[0120] LC/MS purity 100%.
Example 7
2-(1-Piperazinyl)-3-{2-[3-{(2-hydroxyethylamino)methyl}phenoxy]ethoxy}pyrazine
[0121] LC/MS purity 97%.
[0122] Preparation of Pharmaceutical Compositions
[0123] Example: Preparation of Tablets
Ingredients mg/tablet 1. Active compound 10.0 2. Cellulose, microcrystalline 57.0 3. Calcium hydrogen phosphate 15.0 4. Sodium starch glycolate 5.0 5. Silicon dioxide, colloidal 0.25 6. Magnesium stearate 0.75
[0124] The active ingredient 1 is mixed with ingredients 2, 3, 4 and 5 for about 10 minutes. The magnesium stearate is then added, and the resultant mixture is mixed for about 5 minutes and compressed into tablet form with or without film-coating.
[0125] Pharmacological Tests
[0126] The ability of a compound of the invention to bind or act at specific 5-HT receptor subtypes can be determined using in vitro and in vivo assays known in the art. The biological activity of compounds prepared in the Examples was tested using different tests.
[0127] Affinity Assay
[0128] The 5-HT 2c receptor affinity of compounds in the Examples was determined in competition experiments, where the ability of each compound in serial dilution to displace 3 H-labelled 5-HT, bound to membranes prepared from a transfected HEK293 cell line stably expressing the human 5-HT 2c receptor protein, was monitored by Scintillation Proximity Assay technology. Non-specific binding was defined using 5 μM mianserin. Results obtained for exemplary compounds of the invention are illustrated in Table 1 below. Typically, the 5HT 2c receptor affinity values (K i , nM) were in the range of 1 nM to 1500 nM, preferably 1 nM to 100 nM.
TABLE 1 5-HT 2C Receptor Affinity Compound Ki (nM) Example 1 18 Example 5 3
[0129] Efficacy Assay
[0130] The agonist efficacy at the 5-HT 2c receptor of the compounds in the Examples was determined by the ability of each compound to mobilise intracellular calcium in transfected HEK293 cells, stably expressing the human 5-HT 2c receptor protein, using the calcium-chelating fluorescent dye FLUO-3 (Sigma, St. Louis, Mo., U.S.A.).
[0131] Typically, the maximum responses of 5-HT 2c agonists were in the range of 15-100% relative to the maximum response of 5-HT (serotonin) at a concentration of 1 μM.
|
The invention relates to compounds of the general formula (I)
wherein R1, R2 and R3 are as described in the specification, which compounds are ligands to the serotonin 5-HT 2c receptor.
| 2
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. provisional patent application No. 61/961,304 entitled “Method and Apparatus for Melting and Resolidifying ZBLAN Optical Fiber Under Microgravity Conditions” filed Oct. 10, 2013.
FIELD
[0002] This disclosure relates generally to the production of fiberoptic waveguides utilizing a novel melting and resolidifying apparatus and method while under microgravity conditions.
BACKGROUND
[0003] It is well known in prior art of the superior light transmission properties of ZBLAN fiberoptic waveguides (a.k.a. fiber) as well as its application in fiber lasers and amplifiers. Unfortunately, all ZBLAN fiber-forming methods involve fabrication from a melt, which creates inherent problems such as the formation of bubbles, core-clad interface irregularities and inclusions. The ZBLAN fiber drawing process generally occurs at 310° C. in a controlled atmosphere (to minimize contamination by moisture or oxygen impurities which significantly weaken the fiber) using a narrow heat zone compared to silica glass. Drawing is complicated by a small difference (only 124° C.) between the glass transition temperature (approximately 260° C.) and the melting temperature (approximately 310° C.). As a result, ZBLAN fibers often contain undesired crystallites. It is known that the crystallite concentration can be reduced or eliminated by melting and resolidifying ZBLAN in zero gravity (a.k.a. microgravity). The theory is that microgravity conditions reduce convection processes that cause crystallite formation in ZBLAN glasses.
[0004] The disclosed subject matter helps to avoid this and other problems.
[0005] Known art, such as French patent application Nos. 76.18878 and 77.09618, discloses fabricating a ZBLAN optical fiber in 1 G (normal gravity). However, such known methods of fabricating ZBLAN optical fibers often contain undesired crystallites. These optical fibers may suffer from reduced light transmission and, in the case of use in fiber lasers, undesirable heat generation and an associated upper power limit.
[0006] Known art, such as U.S. Pat. No. 2,749,255 by Nack, et. al., discloses cladding a glass fiber with a higher melting temperature cladding via a cladding system comprised of a fiber metalizing system employing nickel carbonyl or gas plating methods. The advantage of this gas plating method is that the metallic cladding (e.g. nickel plating) deposition occurs at a lower temperature (approximately 180-250° C.) than, for example, the ZBLAN glass transition temperature (approximately 260° C.) and the melting point of the ZBLAN glass material (approximately 310° C.)
[0007] Additional known art, such as U.S. Pat. No. 5,991,486 by Braglia, discloses an optical fiber that has the core made of a rare earth doped non-oxide glass and cladding made of an oxide glass. The glass of the core has a melting temperature lower than that of the glass of the cladding and lying within the range of the softening temperatures of the cladding. To produce the fiber, a preform, obtained by introducing an element made of the non-oxide glass into the hole of a capillary tube made of the oxide glass, is brought to a temperature lying within the range of softening temperatures of the oxide glass and not lower than the melting temperature of the non-oxide glass, and is drawn. The capillary tube, during the drawing process, serves as a container for the molten glass of the core.
SUMMARY
[0008] The disclosure relates to an improved apparatus and method for the production of transparent fiberoptic waveguide materials (e.g. ZBLAN) utilizing a novel melting and resolidifying process while under microgravity conditions, and to this end the apparatus is provided with means for manufacturing specially clad optical fiber under normally controlled conditions and, while under the influence of microgravity (e.g. free fall or on-orbit conditions), melting and resolidifying the optical fiber core to eliminate any imperfections in said optical fiber core caused by solidification in a gravity environment.
[0009] The advantage of using the invention is the provision of a novel means of cladding an optical fiber core with a higher melting temperature cladding to permit easy handling (e.g. spooling or bundling) and optical fiber core melting/re-solidification of a compact and contained assembly under microgravity conditions.
[0010] An additional advantage is that the optical fiber can be clad during conventional controlled condition fabrication (i.e. fiber drawing) with a cladding that is of a higher melting temperature than the core ZBLAN material, it being a particular feature of the invention that the cladding is either a glass cladding of higher melting temperature or a vapor deposited higher melting temperature metal cladding or a combination of the two. After cladding is accomplished, the fiber may be wound on a spool, stretched out in strands, bundled in strands, etc., placed in a furnace assembly and exposed to microgravity conditions. While under microgravity conditions, the furnace is activated and the temperature applied is just enough to melt the ZBLAN fiber core but not enough to melt the outer cladding layer(s). The furnace is then allowed to cool over a period of time, while still under microgravity conditions, thus permitting the ZBLAN fiber core to resolidify under microgravity conditions. This method provides a superior transparent ZBLAN product, eliminating any imperfections in said optical fiber caused by solidification in a gravity environment.
[0011] Another advantage offered by the inventive means is the provision of manufacturing the ZBLAN fiber under controlled conditions, exposing it to microgravity conditions, melting, resolidifying and stripping the cladding material from the core ZBLAN fiber without harming the core ZBLAN fiber or exposing it to harmful moisture.
[0012] A further advantage of this method is that it permits individual samples (e.g. 1 meter lengths) of fiber to be processed by first melting the core material and exposing the fiber to microgravity conditions (i.e. a drop tower, aircraft parabolic flight or suborbital flight) for a very short period (e.g. on the order of 1 second to 5 minutes) and rapidly (e.g. on the order of 1 second to 5 minutes) resolidifying the core material under microgravity conditions. This is possible due to the low thermal mass of each piece of fiber. The rapid cooling may be accomplished by some well-known means of quenching (e.g. air blast, refrigerant blast, liquid immersion, etc.). Thus, the fiber samples may be processed under microgravity conditions without the need for transporting to orbit.
DETAILED DESCRIPTION
[0013] In one embodiment, the apparatus of the invention includes fabricating a ZBLAN fiber on Earth via many well-known means in the prior art (e.g. French patent application Nos. 76.18878 and 77.09618) and then cladding the fiber with a higher melting temperature cladding via a cladding system comprised of a fiber metalizing system described for example in U.S. Pat. No. 2,749,255 and other systems well known in the art employing nickel carbonyl or gas plating methods. The advantage of this gas plating method is that the metallic cladding (e.g. nickel plating) occurs at a lower temperature (approximately 180-250° C.) than the ZBLAN glass transition temperature (approximately 260° C.) and the melting point of the ZBLAN core material (approximately 310° C.). This plating method provides a cladding that permits the fiber to be wound on a spool, individual strands can be bundled and heated en masse or the fiber can be transported past a zone heater (e.g. in the fashion of a reel to reel magnetic tape recorder) to melt the ZBLAN core at a temperature of 310° C. without melting the cladding material (e.g. nickel with a melting temperature of 1455° C.) thus preventing the ZBLAN fiber from adhering to itself while coiled on a spool and melted under microgravity conditions in any simple furnace well known in the art.
[0014] The advantage of spooling/bundling the clad optical fiber and melting the optical fiber core on the same spool/bundle versus drawing the fiber from a preform under microgravity conditions is that it provides the highest packing density (i.e. most processed material in the least amount of volume) possible as well as providing an extremely simple and totally automatic on-orbit processing (i.e. melting and cooling system) apparatus. Both advantages are critical for processing under microgravity conditions since volume and mass as well as time are limited resources for space missions or free fall situations.
[0015] Another advantage of this process is that the metallic cladding can be removed by simply exposing the metallic clad fiber to an atmosphere of carbon monoxide gas heated to approximately 130° C., whereupon the nickel cladding combines with the carbon monoxide to form nickel carbonyl gas and is stripped from the optical fiber. After removal of the metallic cladding, the remaining optical fiber can then be clad with any material desired (e.g. a UV curable polymer).
[0016] While nickel carbonyl is cited as the preferred metallic cladding material, other metallic plating materials that are useful in the plating or metallization of the materials described include copper acetyl acetonate; the nitrosyls (nitrosyl carbonyls, for example); cobalt nitrosyl carbonyl; hydrides (such as antimonyhydride or tin hydride); metal alkyls; chromyl chloride; and carbonyl halogens (for example, osmiumcarbonyl broniide, ruthenium carbonyl chloride, and the like).
[0017] In another embodiment, an optical fiber is provided whose core is made of a rare earth doped, non-oxide glass (e.g. ZBLAN), wherein the cladding is made of an oxide glass and wherein, furthermore, the core is made of a glass whose melting temperature is lower than that of the cladding glass and lies within the range of softening temperatures of the latter.
[0018] The term “range of softening temperatures” means, in this description, the temperature range between the glass transition temperature Tg (where the glass has a viscosity of 10 12 Pa·s) and the temperature at which the glass has a viscosity of 10 4 Pa·s (viscosity at which the “gob” falls down by gravity and the fiber can be drawn with minimum force).
[0019] A fiber of this kind eliminates the cladding melting issue, mechanical resistance and chemical inertia problems of fibers completely made of non-oxide glass, since the cladding (which, for example, makes up most of the material of the single mode fiber) is made of an oxide glass.
[0020] Important aspects to be taken into account in choosing the two glasses to be used in a fiber of this kind are given by the thermal expansion coefficient and by the refractive index of the glasses themselves. Specifically, the two glasses must have, at temperatures lower than the glass transition temperature, essentially similar thermal expansion coefficients as well as compatible viscosities, in order to prevent the cladding from inducing stresses on the core or vice versa while the fiber being drawn cools off. In regard to refractive indexes, they must be such that the numerical aperture allows obtaining cores whose radius is in the required order of magnitude. The numerical aperture is given by NA=(n 1 2 −n 2 2 ) 1/2 , with n 1 , n 2 being the refractive indexes of the core and of the cladding respectively, and it is linked to radius r of the core and to wavelength λ by the relation λ=2 πr·NA/2.405. Suitable numerical apertures range between 0.3 and 0.5.
[0021] Non-oxide glasses which can be used in the presence of an oxide glass cladding can be, for instance, ZBLAN glasses, chalcogenide glasses, aluminum fluoride glasses, or phosphate-fluoride glasses.
[0022] These glasses have glass transition temperatures Tg ranging from a minimum of about 265° C. (for ZBLAN) to a maximum of about 475° C. (for glasses containing Ba), melting temperatures in the order of 700-740° C., thermal expansion coefficients α (for temperatures lower than Tg, particularly temperatures in the range 30 to 300° C.) ranging from a minimum of about 11·10 −6 ° C. −1 (for glasses containing Ba or As) and a maximum of about 19·10 −6 ° C. (for ZBLAN), and refractive index ranging from 2 to about 2.5.
[0023] Oxide glasses with glass transition and melting temperatures, thermal expansion coefficients, viscosities and refractive indexes compatible, for the purposes of the present invention, with those of the aforesaid non-oxide glasses are specifically lead silicate glasses with high lead oxide content, preferably between 30% and 70% (molar percentages), whose refractive index varies from 1.69 to 2.14. In choosing the specific composition, it should be kept in mind that glasses whose lead oxide content is close to the upper limits of the range have thermal expansion coefficients which are very similar to those of chalcogenide or ZBLAN glasses and refractive indexes yielding the required numerical aperture for the fiber, but they may have excessively low glass transition temperatures. By contrast, glasses whose lead oxide content is close to the lower limits of the range have suitable glass transition temperatures but may have excessively low thermal expansion coefficients and refractive indexes. Glasses whose lead oxide content is within the preferred range represent, in any case, a good compromise solution, also taking into account that any stresses induced in the drawing process can be eliminated with an annealing operation at temperature lower than the glass transition temperature Tg of the core glass.
[0024] Alternatively, instead of binary SiO 2 ═PbO glasses, lead silicate glasses also containing minor percentages of additional oxides, e.g. TiO 2 , can be used. The presence of these additional oxides allows, as is well known to the person skilled in the art, modifying the characteristics of a lead silicate glass in order to obtain the required compatibility of all parameters of interest in the two glasses.
[0025] Glasses containing oxides of the M 2 O 5 type, where M is Nb or Ta, instead of PbO, are also suitable. The refractive indexes of said glasses also exceed 2.
[0026] Further details of other suitable glasses can be found in U.S. Pat. No. 5,991,486.
[0027] The invention also provides a method for the fabrication of the aforesaid fiber, wherein a preform comprising a cladding and a core is drawn, in which the ratio between the diameters corresponds to that required to obtain the desired optical fiber. According to the invention for preform production an oxide glass capillary tube is used as cladding, into the interior of which there is introduced an element of non-oxide glass (e.g. ZBLAN), whose melting temperature is lower than that of the oxide glass and lies within the range of softening temperatures of the latter, and, for the drawing process, the preform is brought to a temperature lying within said range and not lower than the melting temperature of the non-oxide glass.
[0028] The non-oxide glass element can be introduced into the capillary in its molten state, by capillarity or by pouring, or in its solid state, in the form of a rod.
[0029] As can be clearly seen, with the described method the fiber is obtained either by starting from the non-oxide glass already in its molten state, or by drawing a cold-formed preform.
[0030] The glasses used have preferably melting temperatures (for the non-oxide glass) and softening temperatures (for the oxide glass) ranging between about 700° and 750° C., and such refraction indexes as to give rise, in the drawn fiber, to a numerical aperture ranging between 0.3 and 0.5. Further prior art details of drawing glass clad fibers using this method can be found in U.S. Pat. No. 5,991,486.
[0031] Additionally, the aforementioned method of coating the fiber with metal may be used to apply metal over the aforementioned glass cladding to completely eliminate the possibility of glass cladding adhering to itself during the core melting operation. As stated earlier, the metallic cladding can be removed by simply exposing the metallic clad fiber to an atmosphere of carbon monoxide gas heated to approximately 130° C. whereupon the nickel cladding combines with the carbon monoxide to form nickel carbonyl gas and is stripped from the optical fiber. After removal of the metallic cladding, the remaining optical fiber can then be clad with any material desired (e.g. a UV curable polymer).
[0032] The aforementioned processes also have the advantage of eliminating any exposure to water, water vapor or aqueous solutions, all of which will potentially damage the fiber core.
[0033] It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
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An apparatus used for the fabrication of fiberoptic waveguides utilizing a novel melting and resolidifying apparatus and method while under microgravity conditions is disclosed. In one embodiment, the optical fiber core has a lower melting point than the cladding and the core is melted and resolidified under microgravity conditions. The molten lower melting point core is thus contained by the higher melting point cladding while under microgravity conditions.
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BACKGROUND OF THE INVENTION
The invention concerns a cross frog of a grooved rail junction plate having a cross frog tip movably arranged on a sliding plate, wing rails running along the cross frog tip, as well as auxiliary rails transitioning into connecting bars, which in turn delimit a groove with an allocated section of wing rail.
A corresponding cross frog can be found in AT 326 713. The cross frog tip forms a unit with the auxiliary rail, which in turn is screwed or welded to the connecting bars. The cross frog tip is moreover arranged on a sliding plate, which is supported on bases of the wing rails and the auxiliary rails.
In accordance with DE-A-35 19 683 in order to align the crossings in their correct position with respect to each other, the same are held by an ingot or a supported plate.
A spring-movable cross frog tip for flat bottom rails is known from U.S. Pat. No. 2,377,273.
In a cross frog for junction plates and crossings of a rail of flat bottom rails, the cross frog tip can be pivoted around an axis and has a stub-shaped projection, which extends between the connecting bars that run at a spacing from each other or the adapters connected thereto (DE-A-2061264).
SUMMARY OF THE INVENTION
It is the object of the invention to develop further a cross frog of the kind described above, wherein the cross frog tip has a simple design and can be adjusted within the desired range, making possible a problem-free exchange in the case of a repair or upgrade.
According to a further aspect of the invention, it should be ensured that an incorrect positioning of the cross frog tip is precluded and that a derailment can consequently be prevented.
According to the invention, the object is attained essentially in that the cross frog tip switches over without connection into the auxiliary rail.
Deviating from the prior state of the art, the cross frog tip is not connected to the auxiliary trail or connecting bar. Rather, the cross frog tip itself can be adjusted with respect to the auxiliary rail. Therefore, it is also not required that the cross frog tip have a spring-elastic configuration. The cross frog tip can consequently be configured as a short compact component, which can be adjusted in dependence upon the direction to be traveled.
For this purpose, it is provided that the cross frog tip switches over via a lap joint into the respective auxiliary rail, whereupon the lap joint to be traversed is closed in dependence upon the position of the cross frog tip and a gap runs in the remaining lap joint.
Particularly advantageous conditions result if the impact surface of the auxiliary rail facing toward the cross frog tip encloses an angle α at its travel edge with preferably α≈30°, and the impact surface of the cross frog tip at the connecting line between the pivot point of the cross frog tip and the point of intersection between the impact surface and the travel edge of the cross frog tip enclose an angle β of preferably about 90°.
A particularly stable design results if the auxiliary rail is configured as a four-edge profile of guide rail material. Moreover, the auxiliary rail should be welded to the sliding plate.
In order to be able to pivot the cross frog tip configured as a rigid component within the desired range, it is provided that the cross frog tip can be rotatably mounted on a pivot point plate going out from the sliding plate, wherein a mounting plate, which is connected to the pivot point plate, can extend over the surface along the cross frog tip.
The cross frog tip can be rotatably mounted in accordance with the invention between the pivot point plate going out directly from the sliding plate and the mounting or fixing plate connected thereto, whereupon in particular the pivot point plate is penetrated by a connector or collar, which is the bearing of the cross frog tip, and is connected, for example, screwed, to the mounting plate.
Other bearing possibilities are also possible.
The cross frog tip design should be constructed with a box-like design, wherein the upper boundary of the box is the sliding plate. The latter is connected, in turn, to a support structure, which goes out from the wing rails.
The box design is delimited on the underside by base plates, on which the wing rails are welded.
In a particularly emphasized further development of the invention is proposed a tip configured as a control tip and mounted ahead of the cross frog tip, which can be movably mounted on the sliding plate or one special sliding plate and is positively coupled to the cross frog tip in such a way that a switchover of the control tip leads to a switchover or adjustment of the cross frog tip in the travel direction.
By means of this measure, it is ensured that in the case of an incorrect travel, the cross frog tip rests always on the travel rail in correspondence with the position of the control tip, so that a danger-free passing through is ensured.
The cross frog itself is in particular a flatbed cross frog. The wing rails can consequently be configured as full-head rails with an internal positive side. This ensures the configuration of a stable movable cross frog tip with a good downshift.
The auxiliary rail can be connected via a lap joint to the connecting bar.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details, advantages, and features of the invention result not only from the claims and the features disclosed therein (alone and/or in combination), but also from the following description of the preferred embodiments shown in the drawings,
wherein:
FIG. 1 shows a plan view of the area of a cross frog,
FIG. 2 shows a longitudinal section through the area of the cross frog of FIG. 1 ,
FIG. 3 shows a section view of a sliding plate with pivot point plate,
FIG. 4 shows a mounting plate,
FIG. 5 shows a cross section through a unit of FIGS. 3 and 4 , consisting of a sliding plate, pivot point plate, and mounting plate,
FIG. 6 shows a further embodiment of the area of a cross frog,
FIG. 7 shows a longitudinal section through the area of the cross frog of FIG. 6 ,
FIG. 8 shows a plan view of the area of the cross frog of FIG. 1 with the cross frog tip removed,
FIG. 9 shows a section along the line IX—IX of FIG. 8 , and
FIG. 10 shows a lateral view of the area of the cross frog of FIG. 8 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Different illustrations or sections of the flatbed cross frogs can be seen in the figures, wherein the described design is intended in particular for deep grooves with more than 80 mm, but without having as a result a limitation of the teaching of the invention.
In FIG. 1 is shown a plan view of a cross frog 10 in box-like design having a movable cross frog tip 12 . The cross frog 10 consists as is usual of a base plate 14 having wing rails 16 , 18 welded thereon, as well as connecting bars 20 , 22 , which are connected to auxiliary rails 24 , 26 via a lap joint 28 . The auxiliary rails 24 , 26 can also be sections of correspondingly processed connecting bars or grooved rails.
According to the section view of FIG. 9 , a sliding plate 34 goes out from a support structure 30 , 32 that goes out from the wing rails 16 , 18 , in whose front region 36 the cross frog tip 12 can move, that is, it can be pivoted in the actual sense and slidingly supported.
In the section view of FIG. 1 , it can also be seen that the sliding plate can be connected so as to be vertically adjustable via, for example, a crosslock 66 , to the support structure 32 .
The auxiliary rails 24 , 26 , which are welded by means of the overlapping joint 28 (also called lap joint) to the connecting bars or grooved rails 20 , 22 , are in particular those consisting of rectangular profiles of guide rail material having an edge length of 80 mm. The auxiliary rails 24 , 26 delimit with the wing rails 16 , 18 running alongside thereof grooves 40 , 42 that transition into the grooves of the connecting bars 20 , 22 .
According to the invention, the cross frog tip 12 is a rigid compact component that can be pivoted around an axis 44 in order to rest selectively with its tip 46 on one of the wing rails 16 , 18 in dependence upon the passage direction through the cross frog 10 .
In order to be able to pivot the cross frog tip 12 , a pivot point plate 48 going out from the sliding plate 34 , which is configured in block-like shape or cuboid shape, is welded to said sliding plate and a mounting or fixing plate 50 can be detachably mounted thereon. In accordance with the illustrations shown in FIGS. 2 , 3 and 4 , the mounting plate 50 encompasses moreover the pivot point plate 48 along its longitudinal sides. As a consequence, the mounting plate 50 has, with the exception of its front area 56 , a U-geometry in section, whose lateral legs 52 , 54 extend along longitudinal lateral walls 56 , 58 of the pivot point plate 48 . The mounting plate 50 is moreover detachably connected to the pivot point plate 48 welded to the sliding plate 34 via studs 52 , 54 or other suitable connecting. elements.
The front area 56 of the mounting plate 50 extends above a connector or collar 58 , which is an insert in the pivot point plate 48 . In the intermediate space between the front section 56 of the mounting plate 50 , which extends above the connector of the collar 58 , and the upper side 60 of the pivot point plate 48 , runs a rear section 59 of the cross frog tip 12 , which is penetrated by the connector 58 in correspondence to the section view according to FIG. 8 and consequently forms bearings for the cross frog tip 12 , and therefore specifies the rotation axis 44 . A breakthrough 62 aligned with the connector of the collar 58 is arranged on the mounting plate 50 , which is penetrated by a stud 64 that can be screwed into the connector of the collar 58 .
The cross frog tip 12 has a section in the area of the pivot point plate 48 in order to make possible a pivoting. On the upper side of the cross frog tip 12 , in the area of the mounting plate 50 , is also provided a recess or cavity 66 , into which runs the mounting plate 50 . The depth of the recess 66 with respect to the thickness of the mounting plate 50 is coordinated in such a way that the upper side of the mounting plate 50 runs within the recess 66 or aligned with respect to the outer surface of the cross frog tip 12 . On the other hand, however, it is ensured that the cross frog 12 can be pivoted toward the mounting plate 60 . As a consequence, and induced by the described design, the cross frog tip 12 has a H-shaped geometry in section in its rear area 59 .
The connector 58 of the pivot point plate 48 and the coaction with the rear section 59 of the cross frog tip 12 , taking into consideration the mounting plate 50 and if required any existing spacer washers, ensure the rotational mobility of the cross frog tip 12 within the desired range.
An even transition to one of the auxiliary rails 24 or 26 occurs, on the one hand, in dependence upon the position of the cross frog tip 12 because said tip is a rigid component. On the other hand, a gap forms with respect to the other auxiliary rails 26 or 24 . In order to cross the groove 42 , the cross frog tip 12 rests with its tip 46 on the wing rail 16 in accordance with the depiction of FIG. 1 . At the same time, the cross frog tip 12 transitions evenly into the auxiliary rail 26 that delimits the groove 42 . A gap 68 forms instead between the cross frog tips 12 and the auxiliary rail 24 .
In order to make possible the corresponding adjustments of the cross frog tip 12 with respect to the auxiliary rails 24 , 26 , the auxiliary rail 24 , 26 has an impact surface 70 , 72 running alongside the cross frog tip, which encloses an angle α of preferably 30° with respect to the travel edge 74 , 76 . The impact surface 78 , 80 of the cross frog tip 12 , instead, encloses an angle β of preferably 90° with respect to a straight line 82 , 84 , which connects the rotation axis 44 with the point of intersection of the impact surface 78 , 80 to the travel edge 86 , 88 of the cross frog tip 12 .
Because of these structural design conditions, the impact surfaces are planarly superimposed in the direction of travel, whereas in the direction that is not traveled is formed a gap (the gap 68 in the exemplary embodiment of FIG. 1 ).
In FIGS. 6 and 7 is shown a supplement of the teaching of the invention, wherein the same reference numerals are utilized for the same elements, in accordance with the exemplary embodiment of FIGS. 1 through 4 and 8 through 10 . Thus, the area 100 of a cross frog shown in the plan view of FIG. 6 also exhibits a so-called control tip 102 , which is pivotably arranged on a sliding plate 104 , which runs opposite to the sliding plate 34 with reference to the groove crossing point 106 of the area 100 of the cross frog on which the cross frog tip 12 is pivotably arranged. The control tip 102 is pivotably mounted around an axis 108 , which extends parallel to the rotation axis 44 of the cross frog tip 12 .
The control tip 102 runs with its tip 110 preferably recessed, that is, at a spacing from the break point 112 , 114 of the wing rails 16 , 18 , while the break point 112 , 114 is within the area of the crossing point 106 of the grooves 40 , 42 .
According to the illustration of FIG. 6 , the tip 110 of the control tip 102 can have outwardly bent sections 116 , 118 in its lateral walls, whose corresponding moldings 120 , 122 are allocated to the wing rails 16 , 18 in order to make possible an even abutment.
The control tip 102 is coupled to the cross frog tip 12 in such a way according to the invention, that it is ensured that the cross frog tip 12 is constantly adjusted in the travel direction, in order to preclude an incorrect travel and thereby prevent a derailment, if required. The positive coupling can occur via a swinging fork 124 , which can be pivoted around an axis or a pivot point 126 . The swinging fork 124 is connected thereafter to the cross frog tip 12 and to the control tip 102 .
In order to adjust the cross frog tip 12 and thereby the control tip 102 is provided a drive, which can be operated, for example, electrically or hydraulically. A manual adjustment can also be considered. In the exemplary embodiment, the drive should preferably be allocated to the control tip 102 (symbolized with the double arrow 128 ), even though the cross frog tip 12 should be (preferably) actively driven. A linkage tester should likewise be provided, which is indicated by the double arrow 130 . The linkage tester 130 , swinging fork 124 , and drive 128 , including the corresponding pivot points 114 , run below the sliding plates 34 , 104 , which can also be configured as one piece.
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A cross frog of a grooved rail junction plate having a cross frog tip movably arranged on a sliding plate, wing rails running along the same, as well as auxiliary rails that transition into connecting bars, which delimit a respective groove with an allocated section of wing rail. In order to adjust the cross frog tip within the desired range and to make possible a problem-free exchange in the case of a repair or upgrade with a simple design, it is proposed that the cross frog tip transition without connection into the auxiliary rails.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/141,594, filed Dec. 30, 2008, the entire content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] An aspect of the present invention relates to an optical filter and a flat display panel having the optical filter.
[0004] 2. Description of the Related Art
[0005] As demand for large screen display panels increases among consumers, flat display panels have been widely developed. The flat display panels include liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), organic light emitting displays (OLEDs), and vacuum fluorescent displays (VFDs).
[0006] An optical filter is typically installed on the front surface of a flat display panel. The optical filter is used to protect the display panel from external shock or scratches, prevent reflection of external light, correct colors, shield EMI, enhance bright room contrast, and control other optical characteristics of the display panel. To perform these functions, the optical filter includes multiple function layers, which each include a film and an individual function layer formed on the film. Thus, manufacturing costs increase, and it is difficult to make flat display panel thinner.
SUMMARY OF THE INVENTION
[0007] An aspect of an embodiment of the present invention is directed toward an optical filter in which function layers for enhancing contrast and shielding electromagnetic interference (EMI) are incorporated, and a flat display panel having the optical filter.
[0008] An embodiment of the invention provides an optical filter including: a base film; and a function incorporation layer on the base film and for shielding electromagnetic interference and absorbing external light, the function incorporation layer having a cross mesh pattern, wherein the cross mesh pattern includes a plurality of pattern lines, and wherein at least a part of the cross mesh pattern protrudes from a surface of the function incorporation layer.
[0009] The function incorporation layer may include a base member on the base film, and the cross mesh pattern having at least a part thereof embedded in the base member.
[0010] The base member may have an inner wall defining a groove in the base member, and wherein each of the pattern lines may include: a first conductive layer including an inner portion on the inner wall of the groove and an outer portion; and a second conductive layer being on the inner portion and having a first portion inside the groove and a second portion protruding from a surface of the function incorporation layer; and the outer portion of the first conductive layer being on the second conductive layer.
[0011] The first conductive layer may have a higher external light absorption rate than that of the second conductive layer.
[0012] The second conductive layer may have a higher electric conductivity than that of the first conductive layer.
[0013] Each of the pattern lines may include: a first conductive layer; and a second conductive layer at least partially within the first conductor layer.
[0014] The optical filter may further include a reflection prevention layer, wherein the reflection prevention layer is coated on the function incorporation layer, exposed to light and developed to expose at least one edge portion.
[0015] The optical filter may further include an other base film on the function incorporation layer and a reflection prevention layer on the other base film, wherein the reflection prevention layer is on the other base film, and the reflection prevention layer and the other base film have a smaller size than the function incorporation layer for exposing at least one edge portion of the cross mesh pattern to ground the cross mesh pattern.
[0016] The pattern lines may include: a plurality of first pattern lines parallel to each other and extending in a substantially horizontal direction on a display panel; and a plurality of second pattern lines parallel to each other and extending in a substantially vertical direction on the display panel, the plurality of second pattern lines crossing the plurality of first pattern lines.
[0017] The pattern lines may include: a plurality of first pattern lines parallel to each other and extending in a first direction on a display panel; and a plurality of second pattern lines parallel to each other and extending in a second direction on the display panel, and wherein at least one of the first direction or the second direction is inclined with respect to a vertical or horizontal imaginary line on the display panel, the plurality of second pattern lines crossing the plurality of first pattern lines.
[0018] The pattern lines may include: a plurality of first pattern lines parallel to each other and separated by a first interval, each of the plurality of first pattern lines extending in a first direction and having a first width and a first height; and a plurality of second pattern lines parallel to each other and separated by a second interval, each of the plurality of second pattern lines extending in a second direction crossing the first direction and having a second width and a second height, wherein when the first width is substantially identical to the second width, the second height is smaller than the first height, and the second interval is larger than the first interval.
[0019] Another embodiment of the present invention provides a display device including: a display panel; a base film on the display panel; a function incorporation layer on the base film and for shielding electromagnetic interference and absorbing external light, the function incorporation layer having a cross mesh pattern, wherein the cross mesh pattern includes a plurality of pattern lines, and wherein at least a part of the cross mesh pattern protrudes from a surface of the function incorporation layer facing toward the reflection prevention layer.
[0020] The function incorporation layer may include a base member on the base film, and the cross mesh pattern having at least a part thereof embedded in the base member.
[0021] The base member may have an inner wall defining a groove in the base member, and wherein each of the pattern lines may include: a first conductive layer including an inner portion on the inner wall of the groove and an outer portion; and a second conductive layer being on the inner portion and having a first portion inside the groove and a second portion protruding from a surface of the function incorporation layer facing toward the reflection prevention layer; and the outer portion of the first conductive layer being on the second conductive layer.
[0022] Each of the pattern lines may include: a first conductive layer; and a second conductive layer at least partially within the first conductor layer.
[0023] The first conductive layer may have a higher external light absorption rate than that of the second conductive layer.
[0024] The second conductive layer may have a higher electric conductivity than that of the first conductive layer.
[0025] The display device may further include a reflection prevention layer, wherein the reflection prevention layer is coated on the function incorporation layer, exposed to light and developed to expose at least one edge portion.
[0026] The display device may further include an other base film on the function incorporation layer and a reflection prevention layer on the other base film, wherein the reflection prevention layer is on the other base film, and the reflection prevention layer and the other base layer film have a smaller size than the function incorporation layer for exposing at least one edge portion of the cross mesh pattern to ground the cross mesh pattern.
[0027] The pattern lines may include: a plurality of first pattern lines parallel to each other and extending in a substantially horizontal direction on a display panel; and a plurality of second pattern lines parallel to each other and extending in a substantially vertical direction on the display panel, the plurality of second pattern lines crossing the plurality of first pattern lines.
[0028] The pattern lines may include: a plurality of first pattern lines parallel to each other and extending in a first direction on a display panel; and a plurality of second pattern lines parallel to each other and extending in a second direction on the display panel, and wherein at least one of the first direction or the second direction is inclined with respect to a vertical or horizontal imaginary line on the display panel, the plurality of second pattern lines crossing the plurality of first pattern lines.
[0029] The pattern lines may include: a plurality of first pattern lines parallel to each other and separated by a first interval, each of the plurality of first pattern lines extending in a first direction and having a first width and a first height; and a plurality of second pattern lines parallel to each other and separated by a second interval, each of the plurality of second pattern lines extending in a second direction crossing the first direction and having a second width and a second height, wherein when the first width is substantially identical to the second width, the second height is smaller than the first height, and the second interval is larger than the first interval.
[0030] The display device may further include a color correction adhesive for attaching the base film to the display panel and for performing a color correction.
[0031] The display device may further include: a color correction layer on a surface of the base film facing the display panel; and a transparent adhesive between the color correction layer and the display panel.
[0032] The display device may further include a reflection prevention layer and another base film between the reflection prevention layer and the function incorporation layer, each of the reflection prevention layer and the another base film having a size for exposing the at least one edge portion of the cross mesh pattern to ground the mesh pattern.
[0033] Another embodiment of the present invention provides a display device including: a display panel; a base film on the display panel; a function incorporation layer on the base film and for shielding electromagnetic interference and absorbing external light, the function incorporation layer having a cross mesh pattern; a reflection prevention layer on the function incorporation layer and having a size for exposing at least one edge portion of the cross mesh pattern to ground the cross mesh pattern, wherein at least a part of the cross mesh pattern protrudes from a surface of the function incorporation layer facing toward the reflection prevention layer, wherein the cross mesh pattern includes: plurality of first pattern lines parallel to each other and separated by a first interval, each of the plurality of first pattern lines extending in a first direction and having a first width and a first height; and a plurality of second pattern lines parallel to each other and separated by a second interval, each of the plurality of second pattern lines extending in a second direction crossing the first direction and having a second width and a second height, wherein when the first width is set to be substantially identical to the second width, the second height is smaller than the first height, and the second interval is larger than the first interval, and wherein each of the first and second pattern lines includes: a first conductive layer; and a second conductive layer at least partially within the first conductor layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The accompanying drawings, together with the specification, illustrate exemplary embodiments of the present invention, and, together with the description, serve to explain the principles of the present invention.
[0035] FIG. 1 is a plan schematic view of an optical filter according to an embodiment of the present invention;
[0036] FIG. 2 is a cross-sectional schematic view taken along line II-II of FIG. 1 ;
[0037] FIGS. 3A-3D are cross-section schematic views showing the sequence of a method for forming a function incorporation layer for enhancing contrast and shielding EMI shown in FIG. 2 ;
[0038] FIG. 4 is an enlarged perspective schematic view of a portion A of FIG. 1 ;
[0039] FIG. 5 illustrates the blocking of incident light in the function incorporation layer for enhancing contrast and shielding EMI;
[0040] FIG. 6 is a plan schematic view of an optical filter according to another embodiment of the present invention;
[0041] FIG. 7 is an enlarged perspective schematic view of a portion B of FIG. 6 ;
[0042] FIG. 8 is a plan schematic view of a modified example of the optical filter of FIG. 1 ;
[0043] FIG. 9 is a plan schematic view of another modified example of the optical filter of FIG. 1 ;
[0044] FIG. 10 is a plan schematic view of another modified example of the optical filter of FIG. 1 ;
[0045] FIGS. 11A-11D are cross-sectional schematic views illustrating a method for manufacturing an optical filter according to an embodiment of the present invention;
[0046] FIG. 12 is a cross-sectional schematic view of a flat display panel having an optical filter according to an embodiment of the present invention;
[0047] FIG. 13 is a cross-sectional schematic view of a flat display panel having an optical filter according to another embodiment of the present invention; and
[0048] FIG. 14 is a cross-sectional schematic view of a flat display panel having an optical filter according to another embodiment of the present invention.
DETAILED DESCRIPTION
[0049] In the following detailed description, only certain exemplary embodiments of the present invention are shown and described, by way of illustration. As those skilled in the art would recognize, the invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Also, in the context of the present application, when an element is referred to as being “on” another element, it can be directly on the another element or be indirectly on the another element with one or more intervening elements interposed therebetween. Like reference numerals designate like elements throughout the specification.
[0050] FIG. 1 is a plan schematic view of an optical filter 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional schematic view taken along line II-II of FIG. 1 . Referring to FIGS. 1 and 2 , the optical filter 100 includes a first base film 110 , a function incorporation layer 120 , and a reflection prevention layer 130 .
[0051] The first base film 110 may be formed of a material capable of transmitting a visible ray. The first base film 110 enables the optical filter 100 to be directly attached to the front surface of a display panel. The first base film 110 may be formed of a material including polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethyelenen napthalate (PEN), polyethyeleneterepthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide (PI), polycarbonate (PC), triacetate cellulose (TAC), and/or cellulose acetate propinonate (CAP). However, the material of the first base film 110 is not limited thereto and any material that is flexible and capable of transmitting a visible ray may be employed.
[0052] The first base film 110 may have a set (or predetermined) color. Accordingly, the transmissivity of a visible ray of the optical filter 100 may be adjusted, a viewing experience may be improved, a color purity may be improved, or the color may be corrected. The function incorporation layer 120 is formed on the first base film 110 . In the present embodiment, the function incorporation layer 120 is formed to both perform a bright room contrast enhancement function and the EMI shielding function. That is, the function incorporation layer 120 is a layer in which a contrast enhanced layer and an EMI shield layer are incorporated. The EMI shielding layer shields EMI that is generated by the display panel and harmful to a human body. The contrast enhanced layer enhances bright room contrast by absorbing external light. In the function incorporation layer 120 , a mesh pattern 122 is partially buried in a base member 121 . The mesh pattern 122 is formed to both perform the bright room contrast enhancement function and the EMI shielding function, which will be described in more detail later.
[0053] The mesh pattern 122 a extends horizontally and parallel to one another, and the mesh pattern 122 b extends vertically and parallel to one another, as shown in FIG. 1 . The mesh pattern extending horizontally is referred to as a first mesh pattern 122 a , while the mesh pattern extending vertically is referred to as a second mesh pattern 122 b . The mesh patterns 122 a and 122 b protrude from the upper surface of the base member 121 in the function incorporation layer 120 . Thus, a grounding function to a ground member of the display panel may be improved.
[0054] In the present embodiment, the reflection prevention layer 130 may include a reflection reduction layer and a surface hardness enforcement layer. The reflection reduction layer may be formed of either an anti-reflection (AR) layer or an anti-glare (AG) layer. Alternatively, the reflection reduction layer may be formed of an AR/AG combined layer. Thus, the reflection reduction layer disperses the external light at a surface thereof and reduces (or prevents) the reflection of the surrounding environment by the surface of the optical filter 100 .
[0055] In another embodiment, the reflection prevention layer 130 may be formed of a single layer of a surface hardness enforcement layer. The surface hardness reinforcement layer is a hard coating layer including a hard coating material. Thus, the reflection prevention layer 130 may protect against scratches on the optical filter 100 generated by external matter(s).
[0056] In the present embodiment, the reflection prevention layer 130 is formed on the function incorporation layer 120 . The reflection prevention layer 130 may be formed by coating, for example, a roll wet coating. The reflection prevention layer 130 is formed away from an edge portion of the function incorporation layer 120 such that the mesh pattern 122 may be exposed above the base member 121 . As a result, ground to the ground member is possible. The method for forming the function incorporation layer 120 and the reflection prevention layer 130 on and above the first base film 110 is described in more detail below. The characteristics, materials, and formation method of the reflection prevention layer 130 are not limited to the above-described embodiment.
[0057] Referring to FIGS. 3A-3D , in a method of forming the function incorporation layer 120 for enhancing contrast and shielding EMI of FIG. 2 , the base member 121 having a groove 121 a is prepared. The base member 121 with the groove 121 a may be made by coating a base material forming the base member 121 on a mold designed according to a set (or predetermined) mesh pattern 122 and curing, for example, UV curing, the coated base member 121 . Alternatively, the groove 121 a may be formed in a flat base member 121 in a laser etch method performed according to the set (or predetermined) mesh pattern 122 .
[0058] Next, a first conductive layer 122 aa is formed on the groove 121 a of the base member 121 . The first conductive layer 122 aa is not necessarily black in color and may be in a dark color that is dark enough to effectively absorb external light. For example, the first conductive layer 122 aa may be grey. Thus, the mesh pattern 122 of the function incorporation layer 120 enhances bright room contrast. The first conductive layer 122 aa may have a low electrical conductivity. The first conductive layer 122 aa may be formed of, for example, a material including chromium (Cr) or nickel (Ni).
[0059] Next, a second conductive layer 122 ab is formed on the first conductive layer 122 aa . The second conductive layer 122 ab is to supplement the low conductivity of the first conductive layer 122 aa so that the second conductive layer 122 ab may be formed by plating a metal exhibiting an electrical resistance lower than that of the first conductive layer 122 aa . The second conductive layer 122 ab may be formed of, for example, a material including aluminum (Al), silver (Ag), or copper (Cu). Thus, the electric conductivity of the second conductive layer 122 ab is greater than that of the first conductive layer 122 aa . As a result, the mesh pattern 122 of the function incorporation layer 120 may shield EMI with the same effect as that of the conventional EMI shield layer.
[0060] Finally, a third conductive layer 122 ac is formed on the second conductive layer 122 ab . Although the third conductive layer 122 ac may be formed of the same (or substantially the same) material as and in the same (or substantially the same) method as that of the first conductive layer 122 aa , the present invention is not limited thereto. In one embodiment, the third conductive layer 122 ac has a color that can absorb the external light better than the second conductive layer 122 ab.
[0061] As described above, as the second conductive layer 122 ab exhibiting a higher electrical conductivity but a lower external light absorption characteristic is surrounded by the first conductive layer 122 aa and the third conductive layer 122 ac that are darker than the second conductive layer 122 ab , the bright room contrast of the function incorporation layer 120 may be enhanced. Also, since the second conductive layer 122 ab exhibiting a higher electrical conductivity exists in the mesh pattern 122 of the function incorporation layer 120 , the EMI shield function may also be enhanced. In an embodiment in which the process of FIG. 3D is omitted, the second conductive layer may be formed by utilizing a metal having a dark color, if possible, only when the electrical resistance of the metal is lower than that of the first conductive layer.
[0062] FIG. 4 is an enlarged perspective view of a portion A of FIG. 1 . Referring to FIG. 4 , the mesh pattern 122 of the function incorporation layer 120 includes the first mesh pattern 122 a extending horizontally and parallel to each other and the second mesh pattern 122 b extending vertically and parallel to each other. Since the first mesh pattern 122 a is arranged to extend horizontally, the first mesh pattern 122 a mainly absorbs external light incident at an angle from the upper or lower side of the display panel. Also, since the second mesh pattern 122 b is arranged to extend vertically, the second mesh pattern 122 b mainly absorbs external light incident at an angle from the left or right side of the display panel. A horizontal viewing angle is generally more noticeable (important) than a vertical viewing angle in a flat display panel. Also, in general, it is more important to absorb the external light that is vertically incident. Here, the mesh pattern 122 limits the viewing angle, but absorbs external light.
[0063] Thus, in the horizontal direction, since the absorption of external light is less important, but obtaining a wide viewing angle is more important, to decrease the effect of the second mesh pattern 122 b absorbing the external light that is horizontally incident and assuming that the width of the first mesh pattern 122 a is the same as that of the second mesh pattern 122 b , the height of the second mesh pattern 122 b is set to be lower than that of the first mesh pattern 122 a . Also, the interval between each part of the second mesh pattern 122 b is set to be greater than that between each part of the first mesh pattern 122 a . In contrast, in the vertical direction, since obtaining a wide viewing angle is less important, but the absorption of external light is more important, to increase the effect of the first mesh pattern 122 a absorbing external light that is vertically incident and assuming that the width of the first mesh pattern 122 a is the same (or substantially the same) as that of the second mesh pattern 122 b , the height of the first mesh pattern 122 a is set to be greater than that of the second mesh pattern 122 b . Also, the interval between each part of the first mesh pattern 122 a is set to be less than that between each part of the second mesh pattern 122 b.
[0064] Thus, the optical filter 100 according to the present embodiment is configured such that the absorption of external light in the vertical direction in which incident external light is relatively large may be increased (or maximized) and the obtaining of a viewing angle in the horizontal direction may be increased (or maximized). The mesh pattern 122 of the function incorporation layer 120 of the optical filter 100 is formed both in the vertical and horizontal directions and has a sufficiently high electric conductivity so that the EMI shield function may be sufficiently performed.
[0065] In the embodiment of FIG. 4 , the height of the second mesh pattern 122 b is lower than that of the first mesh pattern 122 a , but the present invention is not limited thereto. For example, the purpose of an aspect of the present invention may be achieved even when the height of the second mesh pattern 122 b is not lower than that of the first mesh pattern 122 a , which will be described below with reference to FIG. 5 .
[0066] FIG. 5 illustrates the blocking of incident light in the function incorporation layer 120 for enhancing contrast and shielding EMI. The size of a mesh pattern 122 a ′ indicated by a two-dot chain line and the interval between the mesh patterns are, respectively, ½ of the size of the mesh pattern 122 a indicated by a solid line and ½ of the interval between the mesh patterns 122 a . FIG. 5 shows that the same external light absorption effect may be obtained in both of the embodiment of the optical filter 10 having the mesh pattern 122 a indicated by a solid line and the embodiment of the optical filter 10 having the mesh pattern 122 a ′ indicated by a two-dot chain line.
[0067] In more detail, assuming that external light is incident at a set (or predetermined) inclination with respect to the surface of the optical filter 100 , external light incident (indicated by the arrows) at the inclination shown in FIG. 5 is all absorbed by the mesh pattern 122 a indicated by the solid line. Likewise, external light incident (indicated by the arrows) at the same inclination is all absorbed by the mesh pattern 122 a ′ indicated by the two-dot chain line. That is, in an ideal state, even when the size (height) of the mesh pattern 122 decreases, by decreasing the interval between each of the mesh pattern 122 a at a similar or the same rate, the capability of absorbing external light may be about the same (or maintained unchanged).
[0068] FIGS. 6 and 7 schematically illustrate an optical filter 200 according to an embodiment of an aspect of the present invention in which the overall size of the first mesh pattern 222 a extending horizontally and parallel to each other using the above principle is decreased by half and the interval between each of the first mesh patterns 222 a is also decreased by half. Referring to FIGS. 6 and 7 , while the size of a second mesh pattern 222 b and the interval between each of the second mesh pattern 222 b are maintained unchanged, the size of a first mesh pattern 222 a and the interval between each of the first mesh pattern 222 a are decreased by half. Accordingly, unlike the embodiment shown in FIG. 4 , in the embodiment shown in FIG. 7 , the height of the second mesh pattern 222 b is not less than that of the first mesh pattern 222 a . Thus, by adjusting the interval between each of the second mesh pattern 222 b or the interval between each of the first mesh pattern 222 a , the technical object of an aspect of the present invention may be achieved without forming the second mesh pattern 222 b to be lower than the first mesh pattern 222 a.
[0069] FIG. 8 is a plan view of an optical filter 300 according to a modified example of the optical filter of FIG. 1 . The optical filter 300 of the present embodiment is different from the optical filter 100 of FIG. 1 in that a second mesh pattern 322 b is inclined at a set (or predetermined) angle of θ 1 , for example, inclined at an angle θ 1 between 0° and 45°, with respect to a vertical imaginary line. This modified example is designed to reduce a Moiré phenomenon that might otherwise occur due to interference between the mesh pattern 122 of the function incorporation layer 120 and the pattern of the display panel 10 , that is, all patterns that may be generated from the display panel 10 including an electrodes pattern and a barrier ribs pattern. In particular, since a first mesh pattern 322 a extending horizontally greatly contributes to the absorption of the external light incident vertically, the first mesh pattern 322 a is maintained parallel to a horizontal imaginary line. The present embodiment is particularly desired for this in mind. However, the present invention is not limited thereto.
[0070] As another modified example of the embodiment of FIG. 1 , a mesh pattern 422 of an optical filer 400 may be arranged as shown in FIG. 9 . Referring to FIG. 9 , in the optical filter 400 of the present embodiment, a second mesh pattern 422 b is inclined at a set (or predetermined) angle of θ 1 , for example, inclined at an angle θ 1 between 0° and 45°, with respect to a vertical imaginary line, and a first mesh pattern 422 a is inclined at a set (or predetermined) angle of θ 2 , for example, inclined at an angle θ 2 between 0° and 45°, with respect to a horizontal imaginary line, which is a difference from the embodiment of FIG. 1 . The reason for this is the same (or substantially the same) as that described above for the embodiment of FIG. 8 .
[0071] As another modified example of the embodiment of FIG. 1 , a mesh pattern 522 of an optical filer 500 may be arranged as shown in FIG. 10 . Referring to FIG. 10 , in the optical filter 500 of the present embodiment, a first mesh pattern 522 a is inclined at a set (or predetermined) angle of θ 2 , for example, inclined at an angle θ 2 between 0° and 45°, with respect to a horizontal imaginary line, which is a difference from the optical filter 100 of FIG. 1 . The reason for this is the same (or substantially the same) as that described above for the embodiment of FIG. 8 .
[0072] FIGS. 11A-11D are cross-sectional schematic views illustrating a method for manufacturing an optical filter 100 according to an embodiment of an aspect of the present invention. First, the base member 121 with a groove 121 a is arranged on the first base film 110 . For example, the base member 121 may be formed by transferring a shape of a mold having a set (or predetermined) mesh pattern 122 to a base material coated on the first base film 110 . Alternatively, after the base member 121 that is flat is formed on the first base film 110 , the groove 122 a may be formed in the upper surface of the base member 121 , for example, by a laser etch method.
[0073] The function incorporation layer 120 is completed by forming the mesh pattern 122 on the base member 121 shown in FIG. 11B . The function incorporation layer 120 may be formed in the method described with reference to FIGS. 3A-3D .
[0074] A material forming the reflection prevention layer 130 is coated on the function incorporation layer 120 shown in FIG. 11C . For the reflection prevention layer 130 , the above descriptions will be referred to. Both side edge portions of the function incorporation layer 120 are separated from the reflection prevention layer 130 (or side edge portions of the reflection prevention layer 130 are removed from the function incorporation layer 120 ) to externally expose the mesh pattern 122 formed at both side edge portions of the function incorporation layer 120 . The separation may be performed by a physical and/or chemical method. For example, chemical etching and/or an optical method by utilizing a laser may be used for the separation. Also, a physical separation in a method of attaching an adhesive tape and detaching the same may be used.
[0075] FIG. 11D illustrates that both side edge portions of the function incorporation layer 120 are separated from the reflection prevention layer 130 , but the scope of the present invention is not limited thereto. For example, only one side edge portion, both side edge portions, or all four side edge portions of the function incorporation layer 120 may be separated from the reflection prevention layer 130 .
[0076] FIG. 12 is a cross-sectional schematic view of the flat display panel 1 having the optical filter 100 according to an embodiment of an aspect of the present invention. Referring to FIG. 12 , the flat display panel of the present embodiment is manufactured by attaching the first base film 110 of the optical filter 100 manufactured in the method shown in FIGS. 11A-11D to the display panel 10 using a color correction adhesive 20 . Here, the color adhesive layer 20 may perform both color correction and adhesion function. By incorporating the color correction layer and the adhesive layer as a single layer, manufacturing costs may be reduced and the manufacturing process may be simplified.
[0077] Thus, as the function incorporation layer 120 and the reflection prevention layer 130 both are included in the first base film 110 , manufacturing costs are reduced and a manufacturing process is simplified so that the flat display panel 1 may be made thinner. Also, not only the EMI shield function but also the bright room contrast enhancement function may be performed by the function incorporation layer 120 that is a single layer.
[0078] FIG. 13 is a cross-sectional view of a flat display panel 2 having an optical filter according to another embodiment of an aspect of the present invention. The present embodiment is different from the embodiment of FIG. 12 in that a color correction layer 22 and an adhesive layer 21 are separately formed. In the optical filters according to the above-described embodiments, both of the function incorporation layer 120 and the reflection prevention layer 130 are formed on the base film 110 that is a single layer. However, the present invention is not limited thereto.
[0079] FIG. 14 is a cross-sectional view of a flat display panel 3 having an optical filter according to another embodiment of an aspect of the present invention. Referring to FIG. 14 , a reflection prevention layer 132 may be formed on a separate base film 131 , and the reflection prevention films 131 and 132 may be formed on the function incorporation layer 120 . The sizes of the reflection prevention films 131 and 132 are determined such that the mesh pattern 122 at least one side edge portion of the function incorporation layer 120 may be exposed. Thus, a separate separation process is not needed.
[0080] The flat display panels 1 , 2 , and 3 according to the embodiments of an aspect of the present invention may be PDPs, LCDs, FEDs, OLEDs, or VFDs. Also, the optical filters 100 , 200 , 300 , 400 , and 500 according to the embodiments of an aspect of the present invention may be used for PDPs, LCDs, FEDs, OLEDs, or VFDs.
[0081] As described above, the optical filters according to embodiments of an aspect of the present invention and the flat display panels according to embodiments of an aspect of the present invention may include both of the function incorporation layer and the reflection prevention layer on a single base film. Thus, manufacturing costs are reduced, a manufacturing process is simplified, and a flat display panel may be made thinner. Also, not only the EMI shielding function but also the bright room contrast enhancement function may be performed by a single function incorporation layer.
[0082] An aspect of the present invention may be utilized in the fields of manufacturing and using an optical filter and a flat display panel having the optical filter.
[0083] An aspect of an embodiment of the invention provides an optical filter including a base film, a function incorporation layer formed on a first surface of the base film, and a reflection prevention layer formed on the function incorporation layer, wherein the function incorporation layer shields electromagnetic interference and absorbs external light. Both of the function incorporation layer and the reflection prevention layer are provided on a single base film. Thus, manufacturing costs may be reduced, a manufacturing process may be simplified, and a flat display panel may be made thinner.
[0084] The function incorporation layer has a mesh pattern having cross patterns in it and at least a part of the mesh pattern may protrude from an upper surface of the function incorporation layer. The function incorporation layer may include a base member formed on a first surface of the base film and a mesh pattern having at least a part thereof buried in the base member and having cross patterns in it. Thus, a ground capability with a ground member of a display panel is guaranteed.
[0085] The reflection prevention layer may be coated on the function incorporation layer. In this case, a separate base film for the reflection prevention layer is not needed. Since all function layers are formed on a single base film, manufacturing costs may be reduced. However, an edge portion corresponding to the reflection prevention layer can be separated so that the mesh pattern at least one side edge portion of the display panel may be externally exposed.
[0086] Alternatively, a reflection prevention film on which the reflection prevention layer is formed may be coupled to the function incorporation layer after the reflection prevention layer is formed on the separate base film. In this case, the size of the reflection prevention film is determined so that the mesh pattern at least one side edge portion of the function incorporation layer may be exposed. Thus, a separate separation process is not needed.
[0087] The mesh pattern may include a first mesh pattern extending in an approximately horizontal direction on the display panel and parallel to each other and a second mesh pattern extending in an approximately vertical direction on the display panel and parallel to each other. The first and second mesh patterns form cross patterns.
[0088] Alternatively, the second mesh pattern may be formed to be inclined with respect to a vertical imaginary line. Then, a Moiré phenomenon generated with the pattern, for example, a lattice shaped pattern, of the display panel may be prevented. Additionally, the first mesh pattern may be formed to be inclined with respect to a horizontal imaginary line. Alternatively, only the first mesh pattern may be formed to be inclined with respect to the horizontal imaginary line.
[0089] Assuming that the width of the first mesh pattern and the width of the second pattern are identical or almost similar to each other, the height of the second mesh pattern is smaller than that of the first mesh pattern. Also, the interval between the second mesh patterns is larger than that between the first mesh patterns. Accordingly, the external light incident in the vertical direction that has a great effect on a bright room contrast is absorbed much by the first mesh patterns while the external light incident in the horizontal direction is relatively less absorbed by the second mesh patterns. Thus, a horizontal viewing angle may be sufficiently obtained while the bright room contrast is enhanced.
[0090] However, the height of the second mesh pattern does not necessarily have to be smaller than the height of the first mesh pattern. By reducing the size, including the width of the first mesh pattern and the interval between the first mesh patterns, at the same reduction rate, the height of the second mesh pattern may be maintained larger than or almost same as the height of the first mesh pattern while the performance of absorbing the external light incident in the vertical direction is maintained.
[0091] Each of the first and second mesh patterns may be formed of an external black conductive layer and an internal conductive layer. The external black conductive layer has a higher external light absorption rate than the inner conductive layer because the color of the external black conductive layer is darker than the inner conductive layer. Thus, the function incorporation layer may enhance the bright room contrast. In contrast, the inner conductive layer has a higher electrical conductivity than the external black conductive layer. Thus, the function incorporation layer may enhance an EMI shield function.
[0092] The mesh pattern may be formed by forming a black conductive layer on an inner wall of a groove of the base member forming the function incorporation layer, a conductive layer inside the groove to protrude from the upper surface of the function incorporation layer, and another black conductive layer on the conductive layer.
[0093] According to another aspect of the embodiment of the invention, there is provided a flat display panel including a display panel, a base film arranged on the front surface of the display panel, a function incorporation layer formed on a first surface of the base film, and a reflection prevention layer formed on the function incorporation layer, wherein the function incorporation layer shields electromagnetic interface and absorbs external light. Both of the function incorporation layer and the reflection prevention layer are provided on a single base film. Thus, manufacturing costs may be reduced, a manufacturing process may be simplified, and a flat display panel may be made thinner.
[0094] The base film may be attached to the flat display panel using a color correction adhesive. The color correction adhesive simultaneously performs a color correction function and an adhesive function. Since a color correction layer and an adhesive layer are incorporated, manufacturing costs may be reduced and a manufacturing process may be simplified.
[0095] Alternatively, the color correction layer may be arranged on a second surface of the base film and the color correction layer may be substantially attached to the first surface of the flat display panel using a transparent adhesive.
[0096] According to another aspect of an embodiment of the invention, there is provided a flat display panel including a display panel, a first base film arranged on the first surface of the display panel, a function incorporation layer formed on a first surface of the first base film, and a reflection prevention layer having a second base film formed on the function incorporation layer, wherein the function incorporation layer shields electromagnetic interface and absorbs external light. The reflection prevention layer is formed on a separate base film and the reflection prevention film is arranged on the function incorporation layer. The size of the reflection prevention film may be determined such that a mesh pattern at least one side edge portion of the function incorporation layer may be exposed. Thus, a separate separation process is not needed.
[0097] While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, and equivalents thereof.
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An optical filter including: a base film; and a function incorporation layer on the base film and for shielding electromagnetic interference and absorbing external light, the function incorporation layer having a cross mesh pattern, wherein the cross mesh pattern includes a plurality of pattern lines, and wherein at least a part of the cross mesh pattern protrudes from a surface of the function incorporation layer facing toward the reflection prevention layer.
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This is a division of application Ser. No. 221,729, filed Jul. 20, 1988, now abandoned.
The invention relates to self-crosslinking vinyl ester dispersions which contain, as crosslinking components, silanolalkoxy- and/or silanoloxy-functional comonomers, if appropriate, in combination with ethylenically unsaturated N-methylolamide and/or N-methylolether amide comonomers.
BACKGROUND OF THE INVENTION
The use of self-crosslinking vinyl ester dispersions in the production of non-wovens is known. Self-crosslinking polymeric binders increase the wet and dry strength on mechanical load and improve the resistance to water and solvents during cleaning. The crosslinking agents employed in practice are predominantly monomers containing N-methylol groups, such as N-methylol drivatives of unsaturated organic acid amides (N-methylolacrylamide) or ethers thereof (N-(iso-butoxyumethyl)-acrylamide). When these compounds are used as crosslinking agents, free methylol groups are present in the dispersion or are formed by hydrolysis of the derivatives in aqueous medium. Formaldehyde is eliminated from N-methylol compounds in aqueous media, but the equilibrium is far over towards the intact methylol group. Aqueous dispersions of self-crosslinking copolymers containing N-methylol groups, therefore, always contain formaldehyde, even if in only small amounts. As a consequence of the toxicological doubts regarding formaldehyde, which have been discussed for some time, and the regulation that only formaldehyde-free plastic dispersion systems may be used for non-wovens in the sanitary and hygiene areas, there is a necessity to reduce the formaldehyde content in self-crosslinking polymer dispersions or to make available formaldehyde-free self-crosslinking polymer dispersions.
Various ways of reducing the formaldehyde content or preparing formaldehyde-free binders for non-wovens are known from the specialized literature.
DE-Al 3,202,122 (U.S.A. 4,476,182) describes formaldehyde-free acrylate dispersions having hydroxyl and carboxyl groups. Although the fiber non-wovens strengthened using these systems have good mechanical values, the resistance towards organic solvents is, however, not sufficient, meaning the crosslinking agents, such as, for example, glyoxal, must be added in order to achieve good stability during cleaning.
In DE-Al 3,328,456 (EP-Al 143,175), formaldehyde-free, crosslinking polymer systems containing crosslinking components based on N-methylolamide and/or N-methylolether amide groups are claimed. The formaldehyde reduction is achieved here by adding a formaldehyde acceptor based on cyclic ureas, such as, for example, ethyleneurea, which bonds the free formaldehyde produced. The disadvantage of this procedure is that the wet strength values, in particular, of the bound non-wovens are reduced by adding water-soluble organic substances, and formaldehyde is still present, although in bound form, and may be liberated, for example, on heating.
A route which is analogous to DE-Al 3,328,456 and has the abovementioned disadvantages is used in EP-Bl 80,635. Here, urea as formaldehyde scavenger is added to the dispersion.
A further process for reducing the content of the free formaldehyde in the binder dispersion is claimed in EP-A3 121,864 (USA 4,449,978). Here, the formaldehyde emission is reduced by replacing N-methylolacrylamide units by acrylamide units. Formaldehyde-free dispersions cannot be obtained using this procedure, but above all, the strength properties and the resistance during cleaning of the non-wovens treated with this binder are greatly reduced.
Formaldehyde-free acrylate dispersions are claimed in EP-A2 193,107. Derivatives of acrylamidoglycolic acid as crosslinking components are copolymerized here with (meth)acrylates. Although the fiber non-wovens strengthened using these dispersions are distinguished by high wet strength and by high water and washing lye resistance, the resistance to organic solvents is, however, unsatisfactory--it is necessary to introduce additional crosslinking agents into the dispersion.
EP-A2 184,153 describes formaldehyde-free binders, for non-wovens, based on copolymers containing unsaturated dicarboxylic acids and (meth)acrylamide as crosslinkable comonomers. Due to the absence of self-crosslinkability, the fiber non-wovens strengthened therewith have inadequate mechanical strength values and poor solvent resistance.
The processes described show that although it is, in priciple, possible to provide formaldehyde-free or formaldehyde-reduced binder systems for strengthening non-wovens, the strength values and, in particular, the solvent resistance, above all in the case of complete substitution, have not yet reached the level of binder systems containing N-methylol units.
The object was, therefore, to develop, as binders for non-wovens, crosslinkable, aqueous copolymer dispersions, above all containing vinyl esters having a greatly reduced content of free formaldehyde or containing no free formaldehyde and imparting good mechanical values and solvent resistances on the strengthened fiber non-wovens.
BRIEF DESCRIPTION OF THE INVENTION
Surprisingly, the object has been achieved in that the crosslinking monomers containing N-methylolamide or N-methylolether amide groups have been substituted, partially or completely, by monomers containing silanolalkoxy groups or silanoloxy groups.
The invention relates to the use of self-crosslinking vinyl ester dispersions having a reduced formaldehyde content or containing no formaldehyde for strengthening textile fiber structures and based on copolymers of the following compositions:
(a) 40-99% by weight of vinyl esters of branched or linear carboxylic acids having 1 to 12 carbon atoms,
(b) 1-6% by weight of vinyltrialkoxysilanes and/or alkylvinyldialkoxysilanes containing branched or linear alkyl or alkoxy radicals having 1 to 4 carbon atoms,
(c) 0-40% by weight of ethylene,
(d) 0-10% by weight of ethylenically unsaturated, hydroxyalkyl-functional compounds,
(e) 0-10% by weight of ethylenically unsaturated carboxylic acids,
(f) 0-5% by weight of amides, N-alkylamides and/or N-alkoxyalkylamides of ethylenically unsaturated carboxylic acids, and
(g) 0-1% by weight of ethylenically polyunsaturated compounds.
The amounts by weight are relative to the total weight of the copolymer, and the individual proportions add up to a total of 100% by weight.
DETAILED DESCRIPTION OF THE INVENTION
As component (a), vinyl acetate, vinyl propionate, vinyl isobutyrate, vinyl 2-ethylhexanoate, vinyl versatate and vinyl laurate, for example, preferably vinyl acetate, can be employed. Component (a) is preferably employed in an amount of 70 to 98% by weight for hard binder systems, and preferably in an amount of 40 to 80% by weight for soft binder systems.
Component (b), employed in amounts from 1-6% by weight, preferably contains methyl radicals as alkyl radicals, and methoxy, ethoxy, methoxyethylene, ethoxyethylene, methoxypropylene glycol ether or ethoxypropylene glycol ether radicals as alkoxy radicals. In particular, vinyl trimethoxysilane and vinyl triethoxysilane are used. Component (b) is preferably copolymerized in amounts from about 1-4% by weight.
Component (c), ethylene, is preferably employed in soft binder systems in amounts from about 5 to 35% by weight.
As component (d), hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and hydroxymethacrylate are preferably employed. Component (d) is preferably copolymerized in amounts from about 0-7.5% by weight.
Component (e) preferably covers monocarboxylic acids, such as acrylic acid, methacrylic acid and crotonic acid, and ethylenically unsaturated dicarboxylic acids and monoesters thereof, such as maleic acid, fumaric acid and itaconic acid. The preferred content of (e) in the polymer is 0 to about 5% by weight.
As component (f), acrylamide, N-methylolacrylamide and N-(iso-butoxymethyl)acrylamide are preferred; (f) is preferably employed in amounts from about 0.5 to about 2.5% by weight. In particular formaldehyde-free polymer dispersions do not contain any compound (f).
As component (g), difunctional and trifunctional, unsaturated compounds, such as allyl methacrylate, divinyl adipate and triallyl cyanurate are preferably employed. Component (g) is preferably employed in amounts up to about 0.75% by weight.
In spite of the high reactivity of the silanoloxy or silanoalkoxy groups, the dispersions containing the copolymers according to the invention are coagulate-free and have a low degree of premature crosslinking and, accordingly, high stability on storage. Surprisingly, a very high degree of self-crosslinking, which even exceeds that of N-methylolamide-containing copolymers, is obtained when using vinyl silanes, which means that extremely high degrees of crosslinking and, accordingly, good values for mechanical strength and solvent resistance are obtained at significantly lower contents than when using N-methylolamide-containing comonomers. This is the decisive factor in making substantial or complete substitution of N-methylolamide-containing comonomers by vinyl silane units possible. A further advantage is the significantly milder crosslinking temperature of vinyl silanes compared with customary self-crosslinking comonomers; this temperature considerably reduces the thermal load during crosslinking and drying of the fiber non-wovens. Finally, due to the more advantageous copolymerization parameters of non-woven binders based on vinyl acetate, the polymerization can be carried out under significantly more economical conditions when N-methylolamide comonomers are substituted by vinyl silanes.
For the broad applicational spectrum of fiber non-wovens strengthened by crosslinking binder systems, various demands are placed on the hardness of the polymer systems, which is known to those skilled in the art under the term "hard and soft hand", and is directly related to the so-called glass-transition temperature of the base polymers used. Thus, hard polymer systems are desired, for example, for strengthening cotton non-wovens and polyester non-wovens for roof sheeting coatings, which can be achieved by using large amounts of vinyl acetate for the copolymers. Soft systems are desired for the production of non-wovens for the hygiene sector such as, for example, cleaning cloths and diapers, which can be achieved by using copolymer systems having glass-transition temperatures of 0° C. This is possible, for example, by using vinyl esters of carboxylic acids having more than four carbon atoms, such as vinyl versatate and vinyl laurate as the principal copolymer component or by copolymerization of ethylene with vinyl esters of carboxylic acids having less than four carbon atoms.
The vinyl ester copolymer dispersions claimed according to the invention can be prepared by customary methods of emulsion polymerization. The monomers may be introduced into the aqueous dispersant at the beginning of the polymerization, but they may alternatively be metered partially or completely during the polymerization. The dispersants used may be any emulsifiers and protective colloids conventionally used in emulsion polymerization. It is possible to use mixtures of protective colloids and emulsifiers, but protective colloids and emulsifiers may each be employed alone. Emulsifiers which can be employed are anionic, cationic and nonionic emulsifiers. The polymerization can be carried out in a temperature range from 0 to 100° C. using water-soluble free-radical forming catalysts which are customary in emulsion polymerization, if appropriate, together with reducing agents. The solids content of the dispersions is 45 to 60% by weight.
The comonomer compositions which contain copolymerized vinyl silane units and are claimed according to the invention can be used to produce fiber non-wovens, strengthened after application and drying, which have good mechanical properties and solvent resistance. Compared with customary polymer compositions containing for example, N-methylolacrylamide units, they have not only the advantage of containing no formaldehyde, but also, due to the milder crosslinking conditions during the silanol condensation, the crosslinking occurs during film formation even at low temperatures of about 50° C.--milder drying conditions can be chosen during strengthening of the non-wovens, which reduces the discoloration of the non-wovens, which is undesirable in practice caused by the high thermal load which is customary for crosslinking and drying.
The binders can be applied to the non-wovens in a manner which is known per se, by impregnation, foam impregnation, spraying, padding or printing. After squeezing out the binder, the impregnated non-woven is dried at about 100 to about 150° C. The binder content in the dried and conditioned non-woven is generally 20-40 % by weight.
EXAMPLE 1
Determination of the degree of crosslinking of the conditioned films
The conditioned films are heated for 6 hours in refluxing ethyl acetate. The ethyl acetate is then evaporated, and the residue remaining is weighted.
DEGREE OF CROSSLINKING
Proportion of the insoluble residue, relative to the total sample weight in ethyl acetate
______________________________________Copolymers Degree of Crosslinking______________________________________96% of VAc 92% 4% of NMA98% of VAc 96% 2% of ViSi96% of VAc 98.5% 4% of ViSi98% of VAc 96% 1% of NMA 1% of ViSi______________________________________ VAc: vinyl acetate NMA: Nmethylolacrylamide ViSi: vinyl trimethoxysilane
EXAMPLE 2
Solvent resistance of the crosslinking binders
Cellulose and polyester non-wovens are strengthened using dispersions containing the copolymers described below. The amount of binder applied is 30% by weight, relative to the total weight of fibers and binder. The maximum tensile forces (N) are determined in the dry and wet state in water and perchloroethylene.
__________________________________________________________________________Example 2 Cellulose non-woven Polyester non-wovenCopolymer 1 min. 1 min.composition Original H.sub.2 O Dry Wet Original H.sub.2 O Dry Wet__________________________________________________________________________Hard binder systemsVAc 96% 17 7 17 8 14 11 16 7NMA 4%VAc 98%NMA 1% 20 8 17 8 12 8 16 7ViSi 1%VAc 97%HEA 1% 14 6 17 7 11 7 14 7ViSi 2%Soft binder systemsVAc 71%E 25% 13 8 11 2 15 11 14 1.5NMA 4%VAc 83%E 15% 13 6 13 2 14 9 14 1.5ViSi 2%__________________________________________________________________________ E = ethylene HEA = hydroxyethyl acrylate
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Binders for strengthening textile fiber structures and based on aqueous, self-crosslinking vinyl ester dispersions having a reduced formaldehyde content or containing no formaldehyde. The low content of free formaldehyde in the dispersion is achieved by partial or complete substitution of the crosslinking comonomers containing N-methylol groups by vinylalkoxysilanes as crosslinking agents. Non-woven treated with these formaldehyde-free or low formaldehyde binder systems are distinguished by high strength values and excellent solvent resistance.
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FIELD OF THE INVENTION
[0001] The present invention relates to electronic seals generally and more particularly to tamper-resistant electronic seals.
BACKGROUND OF THE INVENTION
[0002] The following U.S. Patents are believed to be representative of the prior art:
[0003] U.S. Pat. No. 4,750,197; 5,056,837; 5,097,253; 5,127,687; 5,169,188; 5,189,396; 5,406,263; 5,421,177; 5,587,702; 5,656,996 and 6,069,563.
SUMMARY OF THE INVENTION
[0004] The present invention seeks to provide an improved electronic seal.
[0005] There is thus provided in accordance with a preferred embodiment of the present invention a tamper-resistant remotely monitorable electronic seal including a shaft portion, a socket arranged to engage the shaft portion in a monitorable manner, whereby disengagement of the socket and the shaft portion results in a monitorable event, and a wireless communicator associated with at least one of the shaft portion and the socket and being operative to provide a remotely monitorable indication of the monitorable event. Preferably, the wireless communicator is a transceiver. Additionally, the shaft portion includes at least one conductive path which is interrupted in response to disengagement of the socket and the shaft portion and wherein the wireless communicator is operative to provide a remotely monitorable indication of the monitorable event.
[0006] In accordance with another preferred embodiment of the present invention, the shaft portion includes a frangible shaft portion having a press-fit tip, the socket includes a press-fit socket arranged to engage the press-fit tip in a destructably removable manner, whereby disengagement of the socket and the shaft portion results in breakage of the shaft portion, the at least one conductive path extends at least through the shaft portion and is breakable in response to breakage of the shaft portion, and the wireless communicator is associated with at least one of the shaft portion and the press-fit socket and is operative to provide a remotely monitorable indication of the integrity or lack of integrity of the at least one conductive path. Preferably, the at least one conductive path is defined by conductors extending through the shaft portion which are in electrical contact with a conductor formed in the press-fit socket when the shaft portion and the socket are in press-fit engagement. Additionally, the press-fit tip includes a toothed tip. Alternatively, the at least one conductive path includes at least one reed switch which is operated by a magnet associated with the socket whereby when the shaft portion is separated from the socket for any reason, the at least one conductive path is broken.
[0007] In accordance with yet another preferred embodiment of the present invention, the shaft portion includes a frangible shaft portion having a lockable portion, the socket includes a locking element arranged to engage the lockable portion in a destructably removable manner, whereby disengagement of the locking element and the shaft portion results in breakage of the shaft portion, the at least one conductive path extends at least through the shaft portion and is breakable in response to breakage of the shaft portion, and the wireless communicator is associated with at least one of the shaft portion and the socket and is operative to provide a remotely monitorable indication of the integrity or lack of integrity of the at least one conductive path. Preferably, the shaft portion includes a groove adaptable for lockable engagement with the locking element. Additionally, the at least one conductive path includes at least one reed switch which is operated by a magnet associated with the socket whereby when the shaft portion is separated from the socket for any reason, the at least one conductive path is broken.
[0008] In accordance with a further preferred embodiment of the present invention, the communicator is located in a sensing circuitry and communicator housing integrally formed with the shaft portion. Preferably, the frangible shaft portion includes at least one frangible location having relatively weak mechanical strength as compared with other portions of the shaft portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:
[0010] FIGS. 1A and 1B are simplified pictorial illustrations of two stages in the assembly of a press-fit electronic seal constructed and operative in accordance with a preferred embodiment of the present invention;
[0011] FIGS. 2A and 2B are simplified pictorial illustrations of two different types of breaks produced in the press-fit electronic seal of FIGS. 1A and 1B ;
[0012] FIGS. 3A and 3B are simplified pictorial illustrations of two stages in the assembly of a lockable electronic seal constructed and operative in accordance with a preferred embodiment of the present invention;
[0013] FIGS. 4A and 4B are simplified pictorial illustrations of two different types of breaks produced in the lockable electronic seal of FIGS. 3A and 3B ;
[0014] FIGS. 5A and 5B are simplified pictorial illustrations of two stages in the assembly of a press-fit electronic seal constructed and operative in accordance with another preferred embodiment of the present invention;
[0015] FIGS. 6A and 6B are simplified pictorial illustrations of two different types of breaks produced in the press-fit electronic seal of FIGS. 5A and 5B ;
[0016] FIGS. 7A and 7B are simplified pictorial illustrations of two stages in the assembly of a lockable electronic seal constructed and operative in accordance with another preferred embodiment of the present invention; and
[0017] FIGS. 8A and 8B are simplified pictorial illustrations of two different types of breaks produced in the lockable electronic seal of FIGS. 7A and 7B .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] Reference is now made to FIGS. 1A and 1B , which are simplified pictorial illustrations of two stages in the assembly of a press-fit electronic seal constructed and operative in accordance with a preferred embodiment of the present invention.
[0019] As seen in FIGS. 1A and 1B , there is provided a tamper-resistant electronic seal which preferably comprises a shaft portion 10 , which is integrally formed with or fixed to a sensing circuitry and transceiver portion 12 . Shaft portion 10 preferably has a generally cylindrical configuration and terminates in a press-fit tip 14 , preferably formed with a series of circumferential teeth 16 which are adapted for press-fit engagement with corresponding tooth-like recesses formed in a socket 18 . The press-fit engagement between tip 14 of shaft portion 10 and socket 18 is preferably such that it is impossible to remove the tip 14 from the socket 18 without breaking the shaft portion 10 .
[0020] Shaft portion 10 preferably includes a weakened frangible portion 20 , located intermediate the sensing circuitry and transceiver portion 12 and the tip 14 . Frangible portion 20 is preferably located closer to sensing circuitry and transceiver portion 12 than to tip 14 and typically has a lesser thickness than the remainder of the shaft portion 10 .
[0021] A conductive loop 22 preferably extends through shaft portion 10 through to the tip 14 thereof and is configured and mounted in shaft portion 10 , such that breakage of the shaft portion 10 produces a disconnection or significant change in the electrical properties of the conductive loop 22 .
[0022] In accordance with a preferred embodiment of the present invention, sensing circuitry 23 and an RF transceiver 24 are housed within sensing circuitry and transceiver portion 12 . Sensing circuitry 23 is electrically coupled to conductive loop 22 and senses the integrity thereof. Receiving an output from sensing circuitry 23 is transceiver 24 , which is operative to provide transmitted information indicating whether the conductive loop 22 is intact. Conventional wireless monitoring circuitry (not shown) may be employed to receive information which is transmitted by RF transceiver 24 and indicates tampering with the seal which results in breakage of the shaft portion 10 .
[0023] Reference is now made to FIGS. 2A and 2B , which are simplified pictorial illustrations of two different types of breaks produced in the press-fit electronic seal of FIGS. 1A and 1B . As noted above, application of force to the seal of FIGS. 2A and 2B in an attempt to separate shaft portion 10 from socket 18 will not cause tip 14 to be disengaged from socket 18 , without first breaking the shaft portion 10 . FIG. 2A shows such a break at a location along the shaft portion 10 which lies just above the tip 14 . It is seen that this break produces a disconnection or significant change in the electrical properties of the conductive loop 22 .
[0024] FIG. 2B shows such a break at the frangible portion 20 along the shaft portion 10 . It is seen that this break also produces a disconnection or significant change in the electrical properties of the conductive loop 22 .
[0025] Reference is now made to FIGS. 3A and 3B , which are simplified pictorial illustrations of two stages in the assembly of a lockable electronic seal constructed and operative in accordance with a preferred embodiment of the present invention.
[0026] As seen in FIGS. 3A and 3B , there is provided a tamper-resistant reusable lockable electronic seal which preferably comprises a shaft portion 30 , which is integrally formed with or fixed to a sensing circuitry and transceiver portion 32 . Shaft portion 30 preferably has a generally cylindrical configuration and terminates in a lockable tip 34 , preferably formed with an undercut groove 36 which is adapted for lockable engagement with a corresponding locking element 38 forming part of a lock 40 , defining a socket, which includes a magnet 41 . Lock 40 is here shown to be a key-operated lock, it being appreciated that any other suitable type of lock may be employed. The locking engagement between tip 34 of shaft portion 30 and locking element 38 is preferably such that without first unlocking the lock, it is impossible to remove the tip 34 from engagement with the locking element 38 without breaking the shaft portion 30 .
[0027] Shaft portion 30 preferably includes a weakened frangible portion 42 , located intermediate the sensing circuitry and transceiver portion 32 and the tip 34 . Frangible portion 42 is preferably located closer to sensing circuitry and transceiver portion 32 than to tip 34 and typically has a lesser thickness than the remainder of the shaft portion 30 .
[0028] A conductive loop 44 , including a series connected reed switch 45 which is closed by magnet 41 when shaft portion 30 is in lockable engagement with lock 40 , preferably extends through shaft portion 30 through to the tip 34 thereof and is configured and mounted in shaft portion 30 , such that breakage of the shaft portion 30 produces a disconnection or significant change in the electrical properties of the conductive loop 44 .
[0029] In accordance with a preferred embodiment of the present invention, sensing circuitry 46 and an RF transceiver 48 are housed within sensing circuitry and transceiver portion 32 . Sensing circuitry 46 is electrically coupled to conductive loop 44 and senses the integrity thereof. Receiving an output from sensing circuitry 46 is transceiver 48 , which is operative to provide transmitted information indicating whether the conductive loop 44 is intact. Conventional wireless monitoring circuitry (not shown) may be employed to receive information which is transmitted by RF transceiver 48 and indicates when the shaft portion 30 is located in lockable engagement with lock 40 and when the shaft portion 30 is separated from lock 40 due to either tampering with the seal, which results in breakage of the shaft portion 30 , or disengagement of shaft portion 30 and lock 40 by using a key to unlock lock 40 . It is appreciated that the provision of reed switch 45 and magnet 41 enables sensing circuitry 46 to sense when the shaft portion 30 is located in lockable engagement with lock 40 and when the shaft portion 30 is separated from lock 40 for any reason, and allows for recording of engagements and disengagements of shaft portion 30 and lock 40 .
[0030] Reference is now made to FIGS. 4A and 4B , which are simplified pictorial illustrations of two different types of breaks produced in the lockable electronic seal of FIGS. 3A and 3B . As noted above, application of force to the seal of FIGS. 4A and 4B in an attempt to separate shaft portion 30 from locking element 38 will not cause tip 34 to be disengaged from locking element 38 , without first breaking the shaft portion 30 . FIG. 4A shows such a break at a location along the shaft portion 30 which lies just above the tip 34 . It is seen that this break produces a disconnection or significant change in the electrical properties of the conductive loop 44 .
[0031] FIG. 4B shows such a break at the frangible portion 42 along the shaft portion 30 . It is seen that this break also produces a disconnection or significant change in the electrical properties of the conductive loop 44 .
[0032] It is appreciated that the reed switch and magnet shown in the illustrated embodiments of FIGS. 3A-4B can also be used in the embodiments of FIGS. 1A-2B .
[0033] Reference is now made to FIGS. 5A and 5B , which are simplified pictorial illustrations of two stages in the assembly of a press-fit electronic seal constructed and operative in accordance with another preferred embodiment of the present invention.
[0034] As seen in FIGS. 5A and 5B , there is provided a tamper-resistant electronic seal which preferably comprises a shaft portion 50 , which is integrally formed with or fixed to a sensing circuitry and transceiver portion 52 . Shaft portion 50 preferably has a generally cylindrical configuration and terminates in a press-fit tip 54 , preferably formed with a series of circumferential teeth 56 which are adapted for press-fit engagement with corresponding tooth-like recesses formed in a socket 58 . The press-fit engagement between tip 54 of shaft portion 50 and socket 58 is preferably such that it is impossible to remove the tip 54 from the socket without breaking the shaft portion 50 .
[0035] Shaft portion 50 preferably includes a weakened frangible portion 60 , located intermediate the sensing circuitry and transceiver portion 52 and the tip 54 . Frangible portion 60 is preferably located closer to sensing circuitry and transceiver portion 52 than to tip 54 and typically has a lesser thickness than the remainder of the shaft portion 50 .
[0036] A pair of elongate conductors 62 and 64 preferably extends through shaft portion 50 through to the tip 54 thereof and is configured and mounted in shaft portion 50 , such that breakage of the shaft portion 50 produces a disconnection or significant change in the electrical properties of at least one and preferably both of conductors 62 and 64 . Preferably, conductors 62 and 64 communicate with respective contacts 66 and 68 which are exposed at the end of tip 54 and are arranged to electrically engage an electrical shorting contact 70 at the corresponding interior surface of socket 58 when shaft portion 50 is fully press-fit mounted into socket 58 , thereby defining a conductive loop.
[0037] In accordance with a preferred embodiment of the present invention, sensing circuitry 71 and an RF transceiver 72 are housed within sensing circuitry and transceiver portion 52 . Sensing circuitry 71 is electrically coupled to conductors 62 and 64 and senses the integrity of a conductive loop which is defined by conductors 62 and 64 when the shaft portion 50 is fully seated in socket 58 . Receiving an output from sensing circuitry 71 is transceiver 72 , which is operative to provide transmitted information indicating whether the conductive loop is intact. Conventional wireless monitoring circuitry (not shown) may be employed to receive information which is transmitted by RF transceiver 72 and indicates tampering with the seal which results in breakage of the shaft portion 50 .
[0038] Reference is now made to FIGS. 6A and 6B , which are simplified pictorial illustrations of two different types of breaks produced in the press-fit electronic seal of FIGS. 5A and 5B . As noted above, application of force to the seal of FIGS. 6A and 6B in an attempt to separate shaft portion 50 from socket 58 will not cause tip 54 to be disengaged from socket 58 , without first breaking the shaft portion 50 . FIG. 6A shows such a break at a location along the shaft portion 50 which lies just above the tip 54 . It is seen that this break produces a disconnection or significant change in the electrical properties of the conductive loop defined by conductors 62 and 64 .
[0039] FIG. 6B shows such a break at the frangible portion 60 along the shaft portion 50 . It is seen that this break also produces a disconnection or significant change in the electrical properties of the conductive loop.
[0040] Reference is now made to FIGS. 7A and 7B , which are simplified pictorial illustrations of two stages in the assembly of a lockable electronic seal constructed and operative in accordance with another preferred embodiment of the present invention.
[0041] As seen in FIGS. 7A and 7B , there is provided a tamper-resistant lockable electronic seal which preferably comprises a shaft portion 80 , which is integrally formed with or fixed to a sensing circuitry and transceiver portion 82 . Shaft portion 80 preferably has a generally cylindrical configuration and terminates in a lockable tip 84 , preferably formed with an undercut groove 86 which is adapted for lockable engagement with a corresponding locking element 88 forming part of a lock 90 , defining a socket, which includes a magnet 91 . Lock 90 is here shown to be a key-operated lock, it being appreciated that any other suitable type of lock may be employed. The locking engagement between tip 84 of shaft portion 80 and locking element 88 is preferably such that without first unlocking the lock, it is impossible to remove the tip 84 from engagement with the locking element 88 without breaking the shaft portion 80 .
[0042] Shaft portion 80 preferably includes a weakened frangible portion 92 , located intermediate the sensing circuitry and transceiver portion 82 and the tip 84 . Frangible portion 92 is preferably located closer to sensing circuitry and transceiver portion 82 than to tip 84 and typically has a lesser thickness than the remainder of the shaft portion 80 .
[0043] A pair of elongate conductors 94 and 96 , at least one of which includes a series connected reed switch 98 which is closed by magnet 91 when shaft portion 80 is in lockable engagement with lock 90 , extends through shaft portion 80 through to the tip 84 thereof and is configured and mounted in shaft portion 80 , such that breakage of the shaft portion 80 produces a disconnection or significant change in the electrical properties of at least one and preferably both of conductors 94 and 96 . Preferably, conductors 94 and 96 communicate with respective contacts 102 and 104 which are exposed at the end of tip 84 . Contacts 102 and 104 are arranged to electrically engage an electrical shorting contact 106 at the corresponding interior surface of lock 90 when shaft portion 80 is in lockable engagement with lock 90 . This electrical engagement, together with the closing of series connected reed switch 98 by magnet 91 , thereby defines a conductive loop.
[0044] In accordance with a preferred embodiment of the present invention, sensing circuitry 108 and an RF transceiver 110 are housed within sensing circuitry and transceiver portion 82 . Sensing circuitry 108 is electrically coupled to conductors 94 and 96 and senses the integrity of a conductive loop which is defined by conductors 94 and 96 when the shaft portion 80 is in lockable engagement with lock 90 . Receiving an output from sensing circuitry 108 is transceiver 110 , which is operative to provide transmitted information indicating whether the conductive loop is intact. Conventional wireless monitoring circuitry (not shown) may be employed to receive information which is transmitted by RF transceiver 110 and indicates when the shaft portion 80 is located in lockable engagement with lock 90 and when the shaft portion 80 is separated from lock 90 due to either tampering with the seal, which results in breakage of the shaft portion 80 , or disengagement of shaft portion 80 and lock 90 by using a key to unlock lock 90 . It is appreciated that the provision of reed switch 98 and magnet 91 enables sensing circuitry 108 to sense when the shaft portion 80 is located in lockable engagement with lock 90 and also enables sensing circuitry 108 to sense when the shaft portion 80 is separated from lock 90 for any reason, and allows for recording of engagements and disengagements of shaft portion 80 and lock 90 .
[0045] Reference is now made to FIGS. 8A and 8B , which are simplified pictorial illustrations of two different types of breaks produced in the lockable electronic seal of FIGS. 7A and 7B . As noted above, application of force to the seal of FIGS. 8A and 8B in an attempt to separate shaft portion 80 from locking element 88 will not cause tip 84 to be disengaged from locking element 88 , without first breaking the shaft portion 80 . FIG. 8A shows such a break at a location along the shaft portion 80 which lies just above the tip 84 . It is seen that this break produces a disconnection or significant change in the electrical properties of the conductive loop defined by conductors 94 and 96 .
[0046] FIG. 8B shows such a break at the frangible portion 92 along the shaft portion 80 . It is seen that this break also produces a disconnection or significant change in the electrical properties of the conductive loop defined by conductors 94 and 96 .
[0047] It is appreciated that the reed switch and magnet shown in the illustrated embodiments of FIGS. 7A-8B can also be used in the embodiments of FIGS. 5A-6B .
[0048] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove as well as variations and modifications which would occur to persons skilled in the art upon reading the specification and which are not in the prior art.
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A tamper-resistant remotely monitorable electronic seal including a shaft portion ( 10 ), a socket arranged to engage the shaft position in a monitorable manner, whereby disengagement of the socket (12) and the shaft portion results in a monitorable event, and a wireless communicator associated with at least one of the shaft portion and the socket and being operative to provide a remotely monitorable indication of the monitorable event.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention herein pertains to astragals which are used with dual door installations such as patio or french doors and particularly pertains to astragals having an extruded major component.
2. Description of The Prior Art and Objectives of the Invention
Exterior patio and french doors have become increasingly popular with homeowners and builders in recent years causing a greater demand for weather resistant astragals which are positioned therebetween. Such astragals are positioned for example, to the fixed door to form a side jamb to allow the swingable door to close thereagainst. Other installations use an astragal joined to the head jamb and sill of the door frame between two swingable doors. Conventional astragals were originally constructed entirely of wood and in recent years the durability and maintenance free aspects of aluminum have caused an upsurge in the demand for the more durable, weatherproof aluminum astragals. U.S. Pat No. 4,644,696 illustrates a typical extruded astragal having two major components. Other double door constructions utilize extruded aluminum and wood combinations as shown in U.S. Pat. No. 4,573,287 where the extruded components protect the wood from weather exposure.
Astragals which are formed entirely of aluminum extrusions are durable but are difficult for carpenters and the like to install since door bolts and other fittings necessary for proper door operation must be precisely aligned. Door bolt openings can be factory aligned in the astragals, however if misalignment with the door is discovered at the job site carpenters are perplexed in making the necessary adjustments since the metal extrusions must be cut or shaped with special tools which many carpenters do not have. Also, extruded components cannot be easily patched and painted as can the wood components as is often necessary during construction and assembly. Astragals formed only of wood suffer from harsh weather and must be constantly painted and maintained for proper appearance.
Thus, with the problems and disadvantages of prior art astragals, the present invention was conceived and one of its objectives is provide an astragal utilizing the desired characteristics of both wooden and extruded aluminum components.
It is yet another objective of the present invention to provide an astragal which can be easily assembled and installed at the job site without special tools or training.
It is also an objective of the present invention to provide an astragal having an aluminum extruded exterior portion and a wooden interior portion.
It is still another objective of the present invention to provide an astragal which includes a pair of rearwardly extending walls of different lengths which form a U-shaped channel for securing the interior wooden member tightly therein.
It is yet another objective of the present invention to provide an astragal which can be easily fitted with a door bolt at the job site using conventional carpenter's tools.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.
SUMMARY OF THE INVENTION
The aforesaid and other objectives are realized by providing an astragal consisting of an extruded aluminum exterior portion having a face and a series of rearwardly extending walls. A pair of parallel center walls extending from the face form a channel for receiving a wooden interior portion which can be conveniently cut and fitted with a door bolt and other hardware. The extruded aluminum portion provides weather resistant cladding for the interior portion, yet is aesthetically pleasing and can be quickly installed. The wooden interior portion has a wide exposed section and a narrower clad section which includes a pair of grooves for receiving barbed terminal ends of the rearwardly extending extruded center walls. A seal wall is also provided on the extruded portion in opposing relation to one of the center walls whereby conventional weather stripping can be inserted therebetween to insure a weathertight seal when the door is closed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a patio door installation having a fixed and a swingable door with the astragal of the invention therebetween;
FIG. 2 shows a top sectional view of the installation as seen along lines 2--2 as shown in FIG. 1 but with the swingable door slightly open;
FIG. 3 shows an enlarged top view of the wooden interior portion of the astragal as shown in FIG. 2; and
FIG. 4 shows a top view of the enlarged exterior portion of the astragal as shown in FIG. 2 removed from the interior portion.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred form of the invention is shown in FIGS. 2, 3 and 4 whereby an astragal is formed having a wooden interior portion which is joined to an extruded aluminum exterior portion. The extruded aluminum portion has baked-on enamel or a similar durable finish in a desired color. The extruded portion includes a pair of slightly offset, rearwardly extending center walls which have barbed terminal ends. A seal wall also is provided which includes a serrated surface which provides assistance in holding conventional weather stripping. The wooden interior portion has a wide exposed section and a narrower clad section. Two grooves are positioned in the wooden interior portion along the outer surface for receiving the barbed terminal ends of the center walls of the extruded exterior portion. The narrower clad section of the interior portion has a somewhat rounded end for ease during insertion between the parallel center walls of the exterior extruded portion.
DETAILED DESCRIPTION OF THE DRAWINGS AND OPERATION OF THE INVENTION
For a better understanding of the invention, turning now to the drawings, FIG. 1 illustrates a typical patio door installation having astragal 10 of the invention between fixed door 11 and swingable door 12. Astragal 10 rest on a foam or other weather seal 13 on threshold sill 14. Various other doors could likewise benefit from astragal 10 such as where both doors are swingable and the illustration provided in FIG. 1 is for purposes of explanation of astragal 10 only.
FIG. 2 shows astragal 10 as seen along lines 2--2 of FIG. 1 but with door 12 slightly opened. As seen astragal 10 includes an extruded aluminum exterior portion 15 and a wooden interior portion 16. Weather stripping 17 which comprises a conventional foam weather strip is positioned in extruded exterior portion 15 between left center wall 18 and seal wall 19. Left center wall 18 and right center wall 20 have barbed terminal ends 21, 22 respectively and are different lengths with left center wall 18 extending rearwardly approximately three-fourths of an inch and right center wall 20 extending rearwardly approximately one inch.
Front end 23 of wooden interior portion 16 is somewhat rounded as shown in more detail in FIG. 3. This allows ease in insertion between left center wall 18 and right center wall 20 as illustrated in enlarged fashion in FIG. 4. Wooden interior portion 16 as seen, includes a wide exposed section 24 which has a width at A of approximately eleven-sixteenths of an inch whereas width B of narrower clad section 25 has a width of only approximately nine-sixteenths of an inch. Section 25 has a lesser width than section 24 so outer walls 27, 28 of section 24 will be flush with the outer surfaces of center walls 18, 20 as seen in FIG. 2 upon assembly. As further depicted in FIG. 3, grooves 30, 31 are provided in clad section 25 for reception of respectively, barbed terminal ends 21, 22 of center walls 18, 20 of extruded exterior portion 15 which acts as cladding as earlier explained for wooden interior portion 16. As would also be understood, exterior portion 15 may be extruded aluminum with a baked-on enamel or other finish to withstand harsh weather conditions as it is exposed to the weather as featured in FIG. 1.
In FIG. 4, center line C--C is shown drawn through exterior portion 15 with dimension line D being longer than dimensional line E. Dimension line D is longer than dimension line E as right center wall 20 is further from center line C--C than is left center wall 18. Center walls 18, 20 are offset approximately three-sixteenths of an inch to provide appropriate space for swingable door 12 to open and close. Dimension line D may be for example seven-sixteenths inches in length whereas dimension line E may be only approximately two-sixteenths inches in length. As further shown in FIG. 4, seal wall 19 extends from the front or face 33 of extruded exterior portion 15 substantially in parallel alignment with left center wall 18. Right center wall 20 also extends rearwardly from face 33 in parallel alignment with left center wall 18 but is slightly longer. Seal wall 19 has a serrated inner wall surface 32 which opposes left center wall 18 to assist in gripping weather stripping 17 as seen in FIG. 2. Barbed terminal ends 21, 22 have biased interior faces 41, 42 respectively to ease reception of clad section 25 between center walls 18, 20.
By the use of the combination wooden interior portion 16 and extruded exterior portion 15 which acts as cladding to protect portion 16, ease in working and installation is achieved. With only the use of hand tools carpenters can easily insert wooden portion 16 into exterior extruded portion 15 and can install door bolt 35 for receiving door catch 37 on the job. Wooden portion 16 can be easily secured with wood screws 36 or the like to fixed door 11 as also shown in FIG. 2. Serrated wall surface 32 of seal wall 19 opposes left center wall 18 and forms a pocket therebetween for receiving conventional weather stripping 17 therebetween.
The illustrations and examples provided herein are for explanatory purposes and are not intended to limit the scope of the appended claims.
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An easy to assemble and install astragal is provided consisting of an exterior aluminum extrusion and an interior wooden portion. The exterior extrusion includes a pair of rearwardly extending center walls which form a channel for receiving the wooden interior portion. Attachments and door hardware can be conveniently installed in the wooden interior portion while the extruded exterior acts as cladding for durability.
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RELATED U.S. PATENT DATA
This is a division of U.S. patent application Ser. No. 08/299,621, filed Sep. 2, 1994 now U.S. Pat. No. 5,584,167.
FIELD OF THE INVENTION
This invention relates to working vehicles such as agricultural combines and the like provided with a crawler respectively on the left and the right sides, operating section, driving means with belt and a hulling machine with a grain sorting device.
BACKGROUND OF THE INVENTION
Tracked agricultural combines are a common type of working vehicle. In these prior combines, left and right crawlers or track assemblies are respectively driven by left and right hydrostatic transmission device (hereinafter abbreviated to HST) and steering is conducted by using independent left and right operating levers linked to a trunnion lever of an associated HST. This form of control causes these combines to be difficult to operate smoothly. They are poor in maneuverability because speed changing operations and turning operations have to be made by using the two levers.
Under the circumstances disclosed in Japanese patent publication No. sho 40-18576, speed changing means such as acceleration pedal and turning means such as steering wheel are respectively linked to each trunnion lever of each HST on the left and the right and forward/backward movement is made by using speed changing means and left/right turning movement is made by using turning means in order to conduct operation smoothly.
However, in the conventional art, many kinds of cams are needed to link the speed changing means and the turning means to each gear lever on both sides and accordingly many kinds of bevel gears are needed to couple various means with the cams.
OBJECTIVES AND SUMMARY OF THE INVENTION
Meanwhile, according to this invention it becomes possible to produce a working vehicle comprising: a gear shaft which is put in a gear box 28 and rotates in association with change of gear lever 35; left and right sliders 58, 59 which are designed to slide on gear shaft 33 along its axial line; left and right speed changing means 26, 27 which are linked to said left and right sliders 58, 59 and used to drive left and right crawlers 2; steering wheel 32 which is coupled to said gearbox 28 so as to freely rotate the main slider 53 which is slid by turning said steering wheel and thereby makes said sliders 58, 59 slide, characterized in that said gear shaft 33 and said left and right sliders 58, 59 are moved in one body by manipulating said gear lever 35 in order that said speed changing means 26, 27 may be switched to direct to the same direction at the same time and make said crawlers go straight forward or backward and that either one of said left and right sliders 58, 59 slid by said main slider 53 is put in such position by turning said handle 32 as to stop or move said one of said crawlers in the reverse direction to turn said working vehicle. Because of this invention, the left and the right sliders 58, 59 and the main slider 53 can be incorporated around the gear shaft 33 in a compact manner and the gear lever 35 and the steering wheel 32 can functionally be arranged around the gear shaft 33 and thereby the structure of the operating section A of FIG. 4 can be simplified and the production cost can be easily reduced.
Also in the conventional hulling machine driving systems, the tension roller clutch for applying tension to the belt with a lever to transmit the engine's driving power to the hulling section is used as the clutch of the hulling section. However, in such tension roller clutches, because the lever for switching the clutch is linked to clutch arm with wire, the operating system inevitably becomes much more complex, especially when the clutch of this type is used in a large agricultural machine such as combine. From this standpoint, it seems better to use a clutch motor in place of the aforementioned lever to switch the tension roller clutch. However, when the clutch motor is used at high speed, a large impact tends to be applied on the belt and when it is used at slow speed, maneuverability tends to be poor.
On the contrary, the combine of this invention is comprised of an engine 16 mounted on the machine floor, a belt for transmitting the driving force of said engine to the working section and a tension roller clutch 145 provided approximately in the middle point of the belt. A clutch motor 150 and control means for said tension roller clutch 145 makes the action of said tension roller clutch 145 caused by the input of said clutch motor 150 fast before said tension roller clutch touches said belt and makes said action gradually slow after said tension roller clutch touches said belt. By this device, maneuverability is improved and tension suddenly applied on the belt by sudden switching-on of the clutch motor can be avoided and thereby incidents of its breaking can be minimized to prolong the life of the belt.
Also, as disclosed in Japanese utility model application laid-open publication No. hei 3-108332, in the hulling section, the front grain sorting plate and the rear grain sorting plate are conventionally put one on the other in order that grains may fall through both plates. Therefore, their total thickness is great. Moreover, the difference in each of their weight tends to be great, whereby the difference in momentum between them also tends to be great. For this reason, the structure of vibration control equipment and their driving means can hardly be simplified.
However, the combine according to this invention, in which hulling machine 4, provided with cylinder 5 and grain sorter 7, is mounted on the vehicle floor and thereby substantially forms a combine characterized in that said grain sorter 7 is provided with front grain sorting plate 169 and rear grain sorting plate 170 which allow grains to fall for screening and said rear grain sorting plate 170 is provided with first grain flowing plate 179 to take out screened grains. Therefore, the total length of the two sorting plates can be reduced; the difference in each of their weight can also be reduced and so the difference in momentum between their swinging movement can be reduced. On this account, the structure of vibration control equipment and their driving means can be simplified.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of this invention will be apparent from the following description taken in connection with the accompanying drawing wherein:
FIG. 1 is a side view of the combine.
FIG. 2 is a plan of the combine.
FIG. 3 is a rear view of operating section of the combine.
FIG. 4 is a partially cutaway rear view of the operating section.
FIG. 5 is a cross-sectional bottom view of the operating section.
FIG. 6 is a cross-sectional side view of the operating section taken from the left.
FIG. 7 is another cross-sectional side view of the operating section taken from the left.
FIG. 8 is an illustration showing gear lever in the neutral position and handle in the neutral position too. (At this time the combine is still.)
FIG. 9 is an illustration showing the gear lever in the forwarding position and the handle in the neutral position. (At this time the combine goes straight forward.)
FIG. 10 is an illustration showing the gear lever in the forwarding position and the handle turned clockwise. (At this time the combine turns to the right.)
FIG. 11 is an illustration showing the gear lever in the forwarding position and the handle turned more clockwise. (At this time the combine spins or sharply turns to the right.)
FIG. 12 is a perspective view of the operating section.
FIG. 13 is a rear view of driving system for hulling machine.
FIG. 14 is a cross-sectional view of engine section.
FIG. 15 is a rear view of clutch section.
FIG. 16 is a side view of the clutch section.
FIG. 17 is a plan of the clutch section.
FIG. 18 is a partially enlarged rear view of the clutch section.
FIG. 19 is an illustration showing the whole engine driving system.
FIG. 20 is a side view of the hulling section.
FIG. 21 is a plan of the hulling section.
FIG. 22 is an elevation of the hulling section.
FIG. 23 is a side view of grain sorting machine.
FIG. 24 is an enlarged side view of swinging grain sorting plates.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention will be described in more detail according to the attached drawings. In FIGS. 1 and 2, vehicle floor 1 is mounted on frame 3 which supports two crawlers or propulsion tracks 2, one on the left and one on the right side of the agricultural combine. A hulling machine 4 provided with a screw type transport cylinder 5, a treating drum 6 and a grain sorter 7 is mounted on the vehicle floor 1. Grain tank 8 is designed to hold grains taken out from the hulling machine 4 by way of grain lifting pipe 9. Reaper 10 is designed to move up and down by means of hydraulic pressure cylinder 11 located below in front of the hulling machine 4. The operators' cabin 12 is provided with seat 13 and an operation panel 14 is located before the grain tank 8. Engine cover 15 enclosing engine 16 is located behind the grain tank 8. Auger 17 is for taking out grains from the grain tank 8.
The reaper 10 is provided with a couple of headers 18 to push their front end into yet unreaped plants and feeder house 19 is located behind the middle of the two headers to feed reaped plants to the hulling machine 4. Provided between the headers 18 are reel 20 for taking in unreaped plants, first blade 21 and second blade 22, each capable of alternating motion and auger 23 for taking in reaped plants. Reaped plants taken from the headers 18 are carried to the hulling machine 4 by means of chain conveyer 24 inside the feeder house 19.
Provided on the right side of the hulling machine is a second return pipe 25 to get yet unhulled grains back to the hulling machine 4 through the treating drum 6 in order to get them rehulled and resorted.
FIG. 3 is an outline of the operating system relating to this invention. The operating system controls the position of right tilting plate 26 and left tilting plate 27 which respectively controls an hydraulic pressure motor provided on each HST 120 that drives the crawlers 2 on both sides of the combine, whereby the combine can be moved forward and backward or turned to the right or the left, gently or sharply according to the circumstances.
As shown in FIGS. 3 and 4, in the operating system an operating gear is enclosed in gearbox 28 of which the shape is long in the lateral direction of the combine. In the middle part of top plate 29 of the gearbox 28, a hollow column 30 to house a steering wheel shaft 31 is erected. Provided to on top of the steering wheel shaft 31 is a round steering wheel 32. A main gear shaft 33 is put horizontally in the gearbox 28. To the right outside end 34 of the gear shaft 33, the lower end of gear lever 35 (power transmission control) is fixed by means of lever stay 36. In the figures, 37 denotes foot, 38 denotes wire stay, 39 denotes gear case, 40 denotes brackets for the holding gear case, 41 denotes securing bolts for the gear case, 42 denotes lever guide for the gear lever and 43 denotes the floor.
As shown in FIGS. 5 and 6, base 45 which receives the steering wheel shaft 31 is rotatably placed between the top plate 29 and bottom plate 44. A pinion gear 46 is provided around the base 45 which is supported by bearing 47. Also, as shown in FIGS. 4 to 6, a sliding shaft 50 spanning left and right side walls 48, 49 of the gearbox 28 is placed parallel to the gear shaft 33 at a certain distance thereto. The shape of the cross section of the gear shaft 33 is generally triangular. Bearings 52 support and let the gear shaft rotate freely.
As shown in FIGS. 5 to 7, a main slider 53 is mounted on the sliding shaft 50 in such a way as to freely move to the right and to the left. The main slider 53 is composed of base 54 freely slidable on the sliding shaft 50 and actuator 55 positioned just below the gear shaft 33. A rack 56 extending in the axial direction of the gear shaft 33 is provided under the actuator 55 and allowed to engage with the pinion gear 46. In the figure, 57 denotes the rack guide.
By the above mentioned structure, the main slider 53 is moved to the right or the left on the sliding shaft 50 by means of the rack 56 and the pinion gear 46 which is attached to the base 45 of the steering wheel shaft 31, when the steering wheel 32 is turned to the right (clockwise) or to the left (counter-clockwise).
Two sliders 58 and 59 are slidably mounted on the sliding shaft 50 and the main gear shaft 33, one on the right side and another on the left side thereof. Springs 60 and 61 are attached to the outside of the sliders 58, 59 respectively in order to get the sliders 58, 59 back to the original neutral position. On the other hand, an inverted U shaped stopper 62 is provided in the center of the top plate 29 of the gearbox 28 so that the sliders 58, 59 can be stopped at the neutral position by the stopper. Left arm holder 63 is provided on the right end of the left slider 58 so as to freely rotate thereon, as shown in FIGS. 4 to 7. Moreover, a stopper 64 for preventing the left arm holder 63 from rotating counter-clockwise is extended from the front side of the left arm holder 63 so that the stopper 64 can slide on the sliding shaft 50 freely. A left guide supporting arm 65 is extended down and backward from the rear side of the left arm holder 63. A boss 66 is attached to the end of the arm 65 and a pivot pin 67, the axis of which extends in the longitudinal direction, is horizontally inserted in the boss 66 so as to freely rotate. The rear end of the pivot pin 67 is fixed to the center of the front side of the left guide member 68 which extends in the lateral direction and of which the rear side opens backward. A bushing 69 supports the left arm holder 63.
As shown in FIGS. 4 to 6, a left swinging arm 70 is extended from on the left end of the left slider 58. The upper end of the left link 71, which can be freely extended and contracted, is connected to the end of the left swinging arm 70 by means of connecting pin 72. The lower end of the left link 71 and the front side of the left guide member 68 are connected by means of connecting pin 73.
According to the above mentioned structure, the left guide member 68 is moved with the left slider 58 in one body on the sliding shaft 50 and the main gear shaft 33 in association with the sliding movement of the main slider 53. Also, the left guide member 68 is designed to swing up and down around pivot pin 74 together with the left slider 58 which is rotated in association with the rotating movement of the main gear shaft 33 caused by the gear lever 35. In FIG. 6, W shows the rotation range of the main gear shaft 33 and within the range the end of the left guide 68 swings up and down.
As shown in FIGS. 4 to 7, the left rotator 75 is engaged with the left guide member 68 in such a way as to freely rotate and slide to the right and left along the left guide member. The left rotator 75 and outside end of left rotator supporting arm 76 is joined by means of bearing shaft 77 and the inside end of the arm 76 is joined to the rear wall 79 of the gearbox 28 by means of boss 80 so that the arm 76 can pivot and freely swing up and down with arm bearing shaft 81. Outside the gearbox 28, the end of the arm bearing shaft 81 is joined to the left end of the left tilting plate actuating arm 82 by bolt 83 and the right end of the arm 82 is connected to the right tilting plate 27, which controls hydraulic pressure motor, by means of the left connecting wire 84. In FIG. 5, 85 denotes the stopper for the left rotator 75 and 86 denotes the wire connecting pin.
By this structure, when the left guide member 68 slides to the right or the left keeping its tilting position, the left rotator supporting arm 76 is swung by means of the left rotator 75. At this time, the left tilting plate actuating arm 82 swings up and down oppositely to the swinging movement of the rotator supporting arm 76. This moves the right tilting plate 27 by way of the left connecting wire 84 to control the hydraulic pressure motor.
The above description has been made in relation to a series of members from the left slider 58 to the right tilting plate 27. A similar description can also be made in relation to a series of members from right slider 59 to the left tilting plate 26 because both series of members are made in a symmetrical relationship. However, by way of precaution, the names of the corresponding other members are listed as follows: 87 denotes the right arm holder, 88 the stopper for the right arm holder, 89 the right guide supporting arm, 90 the right boss, 91 the pivot pin, 92 the right guide, 93 the stopper for the right rotator, 94 the right swinging arm, 95 the right link, 97 the connecting pin, 98 the right rotator, 99 the right rotator supporting arm, 100 the bearing shaft, 101 the boss, 102 the arm bearing shaft, 103 the right tilting plate actuating arm, 104 the actuating arm fixing bolt, 105 the right connecting wire, 106 the bushing and 107 the wire connecting pin.
Now a sequence of motions caused by the above mentioned members will be described in reference with FIG. 4 and FIGS. 8 to 11. As shown in FIG. 8, the left and right guides 68, 92, the left and right rotator supporting arms 76, 99 and the left and right tilting plate actuating arms 82, 103 generally keep in the horizontal position as long as the gear lever 35 and the steering wheel 32 are put in the neutral position.
Meanwhile, when the gear lever 35 is put in the forwarding position, the main gear shaft 33 begins to rotate by which the left and right sliders are slid, the left and right swinging arms and the left and right links are moved and the left and right guides 68, 92 are turned around the pivot pins 67, 91. And thereby the left and right rotator supporting arms 76, 99, the arm bearing shafts 81, 102 and the left and right tilting plate actuating arms 82, 103 are put in the tilting position as shown in FIG. 9.
In this case, the tilting angle of the left tilting plate 26 is equal to that of the right tilting plate 27 and so the left and right crawlers 2, turn forward at the same speed; thus, the combine goes straight forward.
However, when the handle is turned clockwise, the steering wheel shaft 31 is rotated accordingly and the rack 56 coupled with the pinion 46 is moved to the left, by which the main slider 53 pushes and makes the left slider 58 slide to the left.
As a result, the left guide 68 coupled with the left slider 58 is slid to the left with its tilting position unchanged and the left rotator 75 is slid generally to the center of the left guide as shown in FIG. 10, by which the left rotator supporting arm 76 and the right tilting plate actuating arm 82 take approximately horizontal positions and the right tilting plate 27 takes an approximately neutral position.
In this case, the speed of the right crawler 2 is decreased or even reduced to zero, while the left crawler 2 keeps advancing as it is. As a result, the combine turns to the right gently.
When the steering wheel 32 is turned more clockwise, the left guide 68 is slid more to the left with its tilting position unchanged and the left rotator 75 having been generally in the middle of the left guide 68 is moved to the right end of the left guide as shown in FIG. 11, by which the left ends of the left rotator supporting arm 76 and the right tilting plate actuating arm 82 are lowered and the right ends are raised. As a result, the right tilting plate 27 is tilted so as to cause the associated crawler to go backward.
In this case, the right crawler 2 turns back, while the left crawler 2 turns fore. Thus, the combine can spin or turn clockwise sharply.
The combine can be spun or turned counter clockwise by turning the steering wheel 32 in the direction opposite the above. Also, regardless of the steering wheel position, the combine can be stopped by getting the gear lever 35 back to the neutral position or moved backward by putting the gear lever in the retreating position or turned to the right or the left while being moved backward by using both the steering wheel and the gear lever. By such excellent maneuverability of the combine many kinds of cropping jobs can be carried out in an efficient manner.
That is, because the combine can be turned freely regardless of the gear lever position or stopped regardless of the steering wheel position, not only is maneuverability easy but misoperation can be avoided and safety of workers in jobs is assured, by which cropping jobs can be made efficiently.
In this example, the sliders 58, 59 are arranged in the left and right of the gearbox 28; however, as a matter of course they can be arranged above and below or obliquely to each other according to the circumstances.
As shown in FIGS. 13 to 19, engine 16 for driving the hulling machine 4, radiator 108 for cooling the engine and sirocco fan 109 for cooling the radiator 108 are arranged separately above and below in the hulling section. Output shaft 111 on the flywheel 110 side of the engine 16 is connected to counter shaft 113 supported by shaft bearing 112 on the right side of the engine 16 by a universal joint 114. Pulleys 115, 116, 117, each fixed to the counter shaft 113, are respectively connected to input pulley 119 of the hulling machine's shaft 118, input pulley 122 of HST's shaft 121 and input pulley 125 of input shaft 124 for driving the auger 123 by using transmission belts 126, 127 and 128 in order to drive the hulling machine 4, the crawlers 2 and the grain tank 8.
The hulling machine shaft 118 and the hulling machine counter shaft 129 are connected to each other by using reduction gears 130, 131 and 132. The hulling machine counter shaft 129 is connected to gearbox shaft 137 by using pulleys 138, 139 and belt 140. The gearbox shaft 137 is connected to the cylinder shaft 133 with two stage speed change gears 134, 135 and switching gear 136, by which the cylinder 5 can be rotated in two, high/low, different speeds. Meanwhile, 141 and 142 denote first and second conveyers of the hulling machine 4, 184 denotes the grain fan and 181 denotes a prefan or an auxiliary fan of the grain fan 184.
Additionally, the tension on the transmission belt 126 connecting the counter shaft 113 and the hulling machine shaft 118 is controlled by the tension roller clutch 145. The tension roller 145, which can be mounted on or dismounted from the belt 126, is held by roller bearing shaft 148 on one upper end of tension arm 147 of which the other lower end is pivotally fixed to bearing shaft 146 on the top of the bearing shaft base 112. On the other side of the belt 126 on which tension is applied by the tension roller clutch 145, there is an electric clutch motor 150 pivotally mounted on plate 149. Shaft 154 on the top of rotating arm 152 fixed to motor shaft 151 and shaft 155 on the top of plate 153 unmovably fixed to the top of the tension roller clutch 145 are connected to each other to jointly move by using tension spring 156 and connecting rod 158 provided with guide rod 157. By this device, the tension roller clutch can be mounted on or dismounted from the belt 126 by turning the motor in right or reverse direction.
The connecting rod 158 which is laid in line with the tension spring 156 between the two shafts 154 and 155 is provided so that it comes to be generally in line with the rotating arm 152 when the tension roller clutch 145 is put on. In this device in order to prolong the belt's life, speed of the tension roller clutch from its touching the belt to its showing the maximum tension is designed to gradually slow down and action in response to on/off of the clutch is also designed to take place after a certain time interval.
The motor shaft 151 is provided with a butting piece 159 so that the piece is butted against stoppers 160, 161 mounted on the clutch motor 150 when the tension roller clutch is switched on or off, whereby the motor's position is limited. More specifically, the piece 159 is butted against the stopper 160 so that the spring 156 and the connecting rod 158 can maintain their position over the fulcrum of the motor shaft 151 when the tension roller clutch is switched on. Also the piece 159 is butted against the stopper 160 so that they can maintain their position when one side of the belt 126 to which the tension roller clutch 145 is touched is so tensed as to get the tension arm 147 back to the off-position and the other side of the belt 126 is slackened by the engine stop (this gives the cylinder 5 inertia rotation), for example, while the tension roller clutch is being switched on, whereby their position is prevented from turning over the limited range.
As described above, compared to the conventional means in which the tension roller clutch and clutch lever are connected with and operated by wire, this new system, in which the on/off switching of the tension roller clutch is conducted by the clutch motor 150, can simplify the structure of the operation section, widely reduce manipulating power and make the tension roller clutch conduct exact on/off switching.
Also in this case, abrupt on/off switching of the tension roller clutch 145 is avoided by putting a certain time interval before that switching by using the motor. That is, when the roller clutch is switched on, action before the belt is tensed by the tension roller clutch can be made to gradually slow down by the semi-circle movement of the rotating arm 152. In this way, the sudden clutch impact on the belt 126 is avoided and the belt is prevented from breaking, whereby the life of the belt can be prolonged.
As shown in FIGS. 20, 21 and 22, the screw-type cylinder 5 is comprised of cylindrical body 162, the length of which is generally equal to the length of the hulling machine 4. A spirally winding vane 163 on the outside of the cylindrical body and projection 164 for exhausting dust is provided at the rear end of the cylindrical body 162. The screw type cylinder 5 is supported by bearings with its axis laid in the longitudinal direction; its front end is an inlet communicating with the feeder house 19 and its rear end is near outlet 167 for purging dust. Provided to under the cylinder is receiving net 168 where the reaped plants taken in from the feeder house can be hulled.
The grain sorter is provided with swinging grain sorting plates 169, 170 to which swinging link 171 gives swinging movement in the longitudinal direction. Provided in the front grain sorting plate 169 is a feed pan 172 under the front part of the cylinder 5, first chaff sieve 173 to regulate the amount of falling grains, first screening net 174 under the first chaff sieve 173 and sieve line 175 connected to the rear part of the first chaff sieve 173. Provided to the rear grain sorting plate 170 is a second chaff sieve 176 under the rear part of the sieving line 175, sieve line 177 connected to the rear part of the second chaff sieve 176, returning plate 178 above the sieve line 177 and below the rear end of the receiving net 168 and first and second grain flowing plates 179, 180. The front end of the returning plate 178 is located above the front end of the sieve line and the rear end thereof is located under the rear end of the receiving net 168.
In addition to the above mentioned members: There is a fan 181 for removing dust which sends sorting air onto the feed pan 172. A grain fan 184 which sends sorting air through the first and second air ducts 182, 183 and under the first chaff sieve 173 and first sorting net 174. A first trough 185 and first conveyer 186 which receives grains from the first sorting net 174 and feeds them to the grain lifting pipe 9. A second sorting fan 187 which sends sorting air under the second chaff sieve 176 and onto the second grain flowing plate 180. A second trough 188 and second conveyer 189 which receive grains from the second flowing plate 180 and sends them to the second returning pipe 25. A third outlet 190 which is in communication with the sieve line 177 on the rear end of the rear grain sorting plate 170 in this system, where grains on the first trough 185 are sent to the grain tank 8 and returned grains on the second trough 188 are sent to the treating drum 6.
As shown in FIGS. 20, 23 and 24, fixed before the rear grain sorting plate 170 is a first grain flowing plate 179. The difference in weight between the front and the rear grain sorting plates 169, 170 is made as little as possible. The first grain flowing plate 179 is always located behind and under the rear end of the first sorting net 174. The rear end of the front grain sorting plate 169 and the front end of the rear grain sorting plate 170 are respectively joined to each end of arm 192, the center of which is held by and can freely swing around pivot 191, whereby when one grain sorting plate goes forward, another goes backward reciprocally. By this device, grains are always sent from the first sorting net 174 through the first flowing plate 179 to the first trough 185 even when the two grain sorting plates are drawn the nearest to or the farthest from each other or even when the amount of grains falling from the first sorting net 174 comes to be great. Also because the first sorting net 174 and the first grain flowing plate 179 are reciprocally moved, grains are prevented from staying on the plate 179 and this makes it possible to screen grains from dust in wet condition and eventually leads to the improvement in working efficiency.
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A tracked agricultural combine vehicle for harvesting, hulling and sorting grain includes a grain working section driven via a tension roller clutch controlled power transmission belt and further including integrated control means for left and right side propulsion track assemblies wherein individual track steering commands in the form of differential track speed control are derived from a common steering wheel input; vehicle speed is controlled by a single input means which controls the speed of both tracks.
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BACKGROUND OF THE INVENTION
The invention relates to the use of additive combinations which are suitable for avoiding undesired skin formation in lacquer systems that dry by oxidation, and for improving the through-drying of the lacquer films.
The additives used according to the invention are characterised by the presence of primary, secondary or tertiary aliphatic amines and/or mixtures thereof in combination with dicarbonyl compounds.
The invention is in the field of colourless and pigmented lacquers and paints which dry by oxidation and are based on oils which dry by oxidation, alkyd resins, epoxy esters and other, refined oils which dry by oxidation, as well as in the field of printing inks. It relates to novel additives which are capable of delaying skin formation in the above-mentioned lacquer systems. Such additive systems are additionally capable of improving the through-drying and the flow of the lacquer systems.
Oils and binders which crosslink by oxidation by the action of oxygen (preferably atmospheric oxygen) by means of the addition of drying agents, for example metal carboxylates of transition metals, and as a result form a solid binder film may form a skin on their surface when they are stored in open or closed containers. That crosslinking, which takes place even before the product is actually used, is undesirable to a large degree and should therefore be avoided, because it renders handling of the lacquer, for example, more difficult and impairs uniform distribution of the siccatives. The accumulation and incorporation of the siccatives that are necessary for drying in the lacquer skin that forms can lead to significant delays in the drying of the lacquer on application.
Skin formation is also disadvantageous and therefore undesirable in the case of the applied lacquer film. Too rapid drying of the lacquer surface prevents uniform through-drying of the lower film layers by shielding them from the oxygen that is necessary for drying, which is unable sufficiently to penetrate the lacquer film and be distributed therein owing to too rapid drying at the surface. Disturbances in the flow of the lacquer film, for example adhesion problems or films which are not sufficiently hard, may result.
It is therefore state of the art to add to the lacquer organic substances which inhibit the reaction of the siccative metal with (atmospheric) oxygen. This can be effected both by binding of the oxygen and by complexing of the siccative metal. That object is achieved in the art mostly by the addition of oximes (especially butanoneoxime) or suitable phenolic compounds. A list of such known compounds will be found, for example, in H. Kittel “Lehrbuch der Lacke und Beschichtungen”, Colomb Verlag 1976; J. Bieleman “Lackadditive” Wiley VCH 1998; Römpp Lexikon “Lacke und Druckfarben”, Thieme Verlag 1998. In WO 00/11090, pyrazoles are recommended for that purpose.
However, phenolic anti-skinning agents markedly delay the onset of drying, so that they are suitable only for specific lacquer formulations. Oximes, on the other hand, such as, for example, methyl ethyl ketoxime or butyraldoxime, delay the onset of drying only slightly owing to their volatility. The most important disadvantage of oximes, which are nowadays used on a large scale, is their toxicity. For example, in a long-term inhalation study on rats and mice, an increased occurrence of liver tumours was observed following exposure to butanoneoxime, on the basis of which the German MAK (maximum concentration at the workplace) commission has classified the substance as a category 2 carcinogen (MAK-Liste 1997). For the user, the result is that complicated personal protective measures must be maintained when processing lacquers containing oximes as anti-skinning agents.
Accordingly, the object of the present invention was to provide anti-oxidants (anti-skinning agents) which prevent skin formation on lacquers over a long period of time and which do not delay the onset of drying, or delay it only very slightly. In addition, the resulting film hardnesses should not be adversely affected, and the products should have no disadvantageous toxicological properties.
A further object of the present Application was to prepare anti-skinning agents which can be incorporated into many different lacquers that dry by oxidation and which, on the basis of their physical properties, can be used without difficulty and widely in corresponding lacquer formulations.
SUMMARY OF THE INVENTION
Accordingly, the invention relates to the use of mixtures, described hereinbelow, of aliphatic amines of the general formula (Ia) and/or their salts of formula (Ib):
in which the radicals
R 1 , R 2 and R 3 each independently of the others represents hydrogen (H), linear or branched C 1 -C 20 -alkyl radical which is optionally unsaturated, optionally mono- or poly-substituted preferably by hydroxyl, alkoxy or amine radical or C 5 - 7 -cycloalkyl radical; the amine radical optionally also being substituted as described, and A − represents a salt-forming anion,
with compounds of formula (II)
in which the radicals
R 1 , and R 4 , each independently of the other represents hydrogen (H), C 1 -C 4 -alkyl radical, C 6 -C 24 -aryl radical or C 5 -C 7 -cycloalkyl radical, hydroxy radical or C 1 -C 4 -alkoxy radical, —O − (oxygen anion), and if present: R 2 , represents H, C 1 -C 4 -alkyl radical, A − (anion) if present: R 3 , represents H, C 1 -C 4 -alkyl radical, and n represents 0, 1 or 2, as anti-skinning agents in lacquers that dry by oxidation.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention there may be used as the salt-forming anion A − halides—such as chloride, bromide, iodide—sulfates such as ½ SO 4 2− , carboxylates such as acetate, butyrate, lactate, etc. In the case of the use according to the invention, it is also possible for the salt-forming anions A − to form in situ from the constituents of the mixture. The salt-forming anion A − is thus formed, for example, from a compound of formula (II) shown.
Within the scope of the invention, mixtures of compounds of the general formulae (Ia), (Ib) and (II) are used alone or in the form of solutions in water and/or organic solvents. All conventional solvents, for example aromatic compounds, white spirit, ketones and alcohols, can be used.
For use, the novel anti-skinning agents of the general formulae (Ia), (Ib) and (II) may be used in any desired admixture with one another. They are preferably used in the ratio (Ia)+(Ib):(II)=from 0.01:10 to 10:0.01 wt. %. They may be used in pure form or in the form of solutions in organic solvents or, alternatively, in the form of an aqueous dispersion or emulsion, aqueous in this connection being understood to mean that water is either the only solvent or is added in an amount of over 50 wt. %, based on the solvent mixture, together with conventional organic solvents (e.g. alcohols).
The amount of the additives employed according to the invention that is used is dependent primarily on the amount of siccatives used in the lacquer formulation. In general, approximately from 1 to 16 moles of mixtures of the compounds of formulae (Ia), (Ib) and (II) are to be added per mole of metal used in the primary drier or primary driers. Preference is given to the use of equimolar mixtures of compounds of formulae (Ia), (Ib) and (II), but it is also possible to use the compounds according to the invention in any other relative proportions. The particular preferred amounts to be used are dependent also on the nature of the binder and of the pigments used. Accordingly, especially preferred amounts in the case of unpigmented lacquers based on long-oil alkyd resins are, for example, from 3 to 9 moles of a compound of formula (Ia) and/or (Ib) in a mixture with from 3 to 9 moles of a compound of formula (II), based on the amount of metal used in the primary drier. In particular systems, the relative amount of additive to be used may even be greater than 16 moles of the mixture according to the invention (based on the amount of metal in the siccative).
It is an advantage of the anti-skinning agents according to the invention that, in a wide range of binders and when different siccatives are used, they reliably prevent skin formation without adversely affecting other drying properties of the lacquer.
EMBODIMENTS
The following embodiments of the mixtures of compounds of formulae (Ia), (Ib) and (II) which are suitable for use according to the invention are to be mentioned as non-limiting examples illustrating the invention:
a) 47% N,N-dimethylethanolamine, 53% 2,4-pentanedione b) 50% N,N-dimethylethanolamine, 50% 2,4-pentanedione c) 68% N,N-dimethylaminododecane, 32% 2,4-pentanedione d) 50% hexadecylamine, 50% 2,4-pentanedione e) 50% cyclohexylamine, 50% 2,4-pentanedione f) 64% dicyclohexylamine, 36% 2,4-pentanedione g) 76% N-methyl-didecylamine, 24% 2,4-pentanedione h) 68% hexadecylamine, 32% 2,5-hexanedione i) 41% ethylenediamine, 59% 2,3-butanedione j) 77% N-methyl-didecylamine, 23% dihydroxyacetic acid k) 50% N,N-dimethylethanolamine, 50% dihydroxyacetic acid l) 63% N,N-dimethylethanolamine, 37% malonic acid m) 75% N-methyl-didecylamine, 25% malonic acid
EXAMPLES OF ANTI-SKINNING AGENTS ACCORDING TO THE INVENTION
1. To a lacquer formulation consisting of 40.0 g of a long-oil alkyd resin (Alkydal F 681® from Bayer AG), 4.0 g of white spirit D 60, 4.0 g of xylene, 1.0 g of n-butanol there are added 0.18 g of a cobalt-containing siccative (Trockner 69® from Borchers GmbH, contains 6 wt. % Co) and 0.4 g of a calcium-containing siccative (Octa-Soligen Calcium 10® from Borchers GmbH, contains 10 wt. % calcium). 0.28 g of the mixture indicated under a) is added to the formulation, and the time taken for a skin to form on the surface of a closed, approximately half-full 125 ml PE beaker is determined. Skin formation was prevented for 63 days. By comparison, the skinning time, determined under identical conditions, of a sample without anti-skinning additive was 8 days, and that of a sample containing a conventional, suitable amount of butanoneoxime (0.1 g) was 23 days. The drying time of a corresponding lacquer film (100 μm wet film layer thickness) of the mixture according to the invention was 3 hours 40 minutes (needle track drying in accordance with test specification 100-94 of Borchers GmbH). The drying time, determined under identical conditions, of a lacquer film without anti-skinning additive was 3 hours 50 minutes, and that of a sample containing a conventional, suitable amount (0.1 g) of butanoneoxime was determined as 8 hours. The pendulum hardness according to König (determined in accordance with DIN 53 157) of the above-mentioned films was 21 seconds after a storage time of one week for all three samples.
2. To a lacquer formulation consisting of 40.0 g of a long-oil alkyd resin (Alkydal F 681® from Bayer AG), 4.0 g of white spirit D 60, 4.0 g of xylene, 1.0 g of n-butanol there are added 0.18 g of a cobalt-containing siccative (Trockner 69® from Borchers GmbH, contains 6 wt. % Co) and 0.4 g of a calcium-containing siccative (Octa-Soligen Calcium 10® from Borchers GmbH, contains 10 wt. % calcium). 0.23 g of the mixture indicated under g) is added to the formulation, and the time taken for a skin to form on the surface of a closed, approximately half-full 125 ml PE beaker is determined. Skin formation was prevented for more than 60 days. By comparison, the skinning time, determined under identical conditions, of a sample without anti-skinning additive was 5 days, and that of a sample containing a conventional, suitable amount of butanoneoxime (0.1 g) was 52 days. The drying time of a corresponding lacquer film (100 μm wet film layer thickness) of the mixture according to the invention was 2 hours 50 minutes (needle track drying in accordance with test specification 100-94 of Borchers GmbH). The drying time, determined under identical conditions, of a sample without anti-skinning additive was 3 hours 30 minutes, and that of a sample containing a conventional, suitable amount (0.1 g) of butanoneoxime was determined as 4 hours.
3. To a lacquer formulation consisting of 40.0 g of a long-oil alkyd resin (Alkydal F 681® from Bayer AG), 4.0 g of white spirit D 60, 4.0 g of xylene, 1.0 g of n-butanol there are added 0.18 g of a cobalt-containing siccative (Trockner 69® from Borchers GmbH, contains 6 wt. % Co) and 0.4 g of a calcium-containing siccative (Octa-Soligen Calcium 10® from Borchers GmbH, contains 10 wt. % calcium). 0.44 g of the mixture indicated under e) is added to the formulation, and the time taken for a skin to form on the surface of a closed, approximately half-full 125 ml PE beaker is determined. Skin formation was prevented for 104 days. By comparison, the skinning time, determined under identical conditions, of a sample without anti-skinning additive was 8 days, and that of a sample containing a conventional, suitable amount of butanoneoxime (0.1 g) was 23 days. The drying time of a corresponding lacquer film (100 μm wet film layer thickness) of the mixture according to the invention was 3 hours 35 minutes (needle track drying in accordance with test specification 100-94 of Borchers GmbH). The drying time, determined under identical conditions, of a sample without anti-skinning additive was 3 hours 50 minutes, and that of a sample containing a conventional, suitable amount of butanoneoxime (0.1 g) was determined as 8 hours. The pendulum hardness according to König (determined in accordance with DIN 53 157) of a lacquer film to which the mixture according to the invention had been added was 23 seconds after a storage time of one week. By comparison, the pendulum hardness, determined under identical conditions, of the above-mentioned lacquer films without anti-skinning additive or with butanoneoxime was in each case 21 seconds after a storage time of one week.
4. To a lacquer formulation consisting of 40.0 g of a long-oil alkyd resin (Alkydal F 681® from Bayer AG), 4.0 g of white spirit D 60, 4.0 g of xylene, 1.0 g of n-butanol there are added 0.18 g of a cobalt-containing siccative (Trockner 69® from Borchers GmbH, contains 6 wt. % Co) and 0.4 g of a calcium-containing siccative (Octa-Soligen Calcium 10® from Borchers GmbH, contains 10 wt. % calcium). 0.26 g of the mixture indicated under h) is added to the formulation, and the time taken for a skin to form on the surface of a closed, approximately half-full 125 ml PE beaker is determined. Skin formation was prevented for more than 25 days. The drying time of a corresponding lacquer film (100 μm wet film layer thickness) of the mixture according to the invention was 5 hours 30 minutes (needle track drying in accordance with test specification 100-94 of Borchers GmbH). By comparison, the skinning time, determined under identical conditions, of a sample without anti-skinning additive was 4 days. The drying time, determined under identical conditions, of a sample without anti-skinning additive was 5 hours.
5. To a lacquer formulation consisting of 40.0 g of a long-oil alkyd resin (Alkydal F 681® from Bayer AG), 4.0 g of white spirit D 60, 4.0 g of xylene, 1.0 g of n-butanol there are added 0.18 g of a cobalt-containing siccative (Trockner 69® from Borchers GmbH, contains 6 wt. % Co) and 0.4 g of a calcium-containing siccative (Octa-Soligen Calcium 10® from Borchers GmbH, contains 10 wt. % calcium). 0.05 g of the mixture indicated under i) is added to the formulation, and the time taken for a skin to form on the surface of a closed, approximately half-full 125 ml PE beaker is determined. Skin formation was prevented for more than 25 days. By comparison, the skinning time, determined under identical conditions, of a sample without anti-skinning additive was 6 days, and that of a sample containing a conventional, suitable amount (0.1 g) of butanoneoxime was 17 days. The drying time of a corresponding lacquer film (100 μm wet film layer thickness) of the mixture according to the invention was 4 hours (needle track drying in accordance with test specification 100-94 of Borchers GmbH). The drying time, determined under identical conditions, of a sample without anti-skinning additive was 5 hours, and that of a sample containing a conventional, suitable amount of butanoneoxime (0.1 g) was determined as 4 hours 30 minutes. The pendulum hardness according to König (determined in accordance with DIN 53 157) of the lacquer film to which the mixture according to the invention had been added was 35 seconds after a storage time of one week. By comparison, the pendulum hardness, determined under identical conditions, of the lacquer film without anti-skinning additive was 33 seconds after a storage time of one week.
6. To a lacquer formulation consisting of 40.0 g of a long-oil alkyd resin (Alkydal F 681® from Bayer AG), 4.0 g of white spirit D 60, 4.0 g of xylene, 1.0 g of n-butanol there are added 0.18 g of a cobalt-containing siccative (Trockner 69® from Borchers GmbH, contains 6 wt. % Co) and 0.4 g of a calcium-containing siccative (Octa-Soligen Calcium 10® from Borchers GmbH, contains 10 wt. % calcium). 0.26 g of the mixture indicated under k) is added to the formulation, and the time taken for a skin to form on the surface of a closed, approximately half-full 125 ml PE beaker is determined. Skin formation was prevented for 70 days. By comparison, the skinning time, determined under identical conditions, of a sample without anti-skinning additive was 5 days, and that of a sample containing a conventional, suitable amount of butanoneoxime (0.1 g) was 36 days. The drying time of a corresponding lacquer film (100 μm wet film layer thickness) of the mixture according to the invention was 2 hours (needle track drying in accordance with test specification 100-94 of Borchers GmbH). The drying time, determined under identical conditions, of a sample without anti-skinning additive was 2 hours 50 minutes, and that of a sample containing a conventional, suitable amount (0.1 g) of butanoneoxime was determined as 2 hours 30 minutes.
7. To a lacquer formulation consisting of 41.0 g of a medium-oil alkyd resin (Alkydal F 48® from Bayer AG), 4.0 g of white spirit D 60, 4.0 g of xylene, 1.0 g of n-butanol there are added 0.08 g of a cobalt-containing siccative (Trockner 69® from Borchers GmbH, contains 6 wt. % Co) and 0.4 g of a calcium-containing siccative (Octa-Soligen Calcium 10® from Borchers GmbH, contains 10 wt. % calcium). 0.18 g of the mixture indicated under 1) is added to the formulation, and the time taken for a skin to form on the surface of a closed, approximately half-full 125 ml PE beaker is determined. Skin formation was prevented for 52 days. By comparison, the skinning time, determined under identical conditions, of a sample without anti-skinning additive was 7 days.
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The present invention relates to a coating composition containing an oxidatively drying binder and, as anti-skinning agents, a mixture of
A) an aliphatic amine corresponding to formula (Ia) and/or its salts corresponding to formula (Ib):
wherein
R 1 , R 2 and R 3 each independently of the others represents hydrogen (H); a linear or branched C 1 -C 20 -alkyl radical which is optionally unsaturated or which is optionally mono- or poly-substituted by a hydroxyl radical, an alkoxy radical, an amine radical corresponding to the formula N(R 1 )(R 2 ), or a C 5 -C 7 -cycloalkyl radical, and A − represents a salt-forming anion, and
B) with a compound corresponding to formula (II)
wherein
R 1 and R 4 each independently of the other represents hydrogen (H), a C 1 -C 4 -alkyl radical, a C 6 -C 24 -aryl radical or a C 5 -C 7 -cycloalkyl radical, a hydroxyl radical or a C 1 -C 4 -alkoxy radical, —O − (oxygen anion), R 2 represents H, a C 1 -C 4 -alkyl radical, or A − (anion), R 3 represents H, a C 1 -C 4 -alkyl radical, and n represents 0, 1 or 2.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a sensor IC, and more particularly, to a sensor IC such as a magnetic sensor IC integrated with a magnetic sensor and additional circuits, and a pressure sensor IC integrated with a pressure sensor and additional circuits.
2. Description of the Related Art
FIG. 1 shows a schematic diagram of a prior art magnetic sensor IC. The magnetic sensor IC 21 is constructed with a single Hall sensor Hs, a single differential amplifier DAV, and load resistors Rc1, Rc2, all of which are formed on the same semiconductor chip.
The Hall sensor Hs is provided with the power source voltage Vcc, and is operative with a constant voltage. A sensor output voltage produced from an output terminal of the Hall sensor Hs is given by a sum of an unbalanced voltage V Hoff in the Hall sensor Hs and a product (V HO .B) of sensitivity V HO of the Hall sensor Hs and magnetic flux density B of a magnetic field applied to the magnetic sensor IC 21.
The sensor output voltage of the Hall sensor Hs is provided to input terminals of the differential amplifier DAV. The differential amplifier DAV is constructed with transistors Q1, Q2, a current-feedback resistor R E , and constant current sources J1, J2. Output currents Ic1, Ic2 of the differential amplifier DAV are respectively converted to voltages by the load resistors Rc1, Rc2, and are produced as an output voltage Vout1 between output terminals T6, T7.
In the differential amplifier DAV, values of the load resistors Rc1, Rc2, the current-feedback resistor R E , and bias currents I1, I2 generated in the current sources J1, J2 are adjusted so that a voltage gain of the differential amplifier DAY could be a value A, where Rc1=Rc2, and I1=I2.
In this case, the output voltage Vout1 of the magnetic sensor IC 21 is given by the following equation (1).
Vout1=A.V.sub.HO.B+A.(V.sub.Hoff +V.sub.Aoff) (1)
where
A: voltage gain of the differential amplifier DAV,
VHO: sensitivity of the Hall sensor Hs,
B: magnetic flux density of a magnetic field applied to the magnetic sensor IC,
V Hoff : an unbalanced voltage in the Hall sensor Hs, and
V Aoff : an input offset voltage of the differential amplifier DAV.
In the equation (1), a first term indicates a Hall output voltage component when the magnetic flux density B is applied to the magnetic sensor IC 21. The following equation (2), which is given by dividing the first term of the equation (1) by the magnetic flux density B, indicates sensitivity K1 of the magnetic sensor IC 21.
K1=A.V.sub.HO ( 2)
A second term of the equation (1) is given by multiplying the sum of the unbalanced voltage V Hoff and the input offset voltage V Aoff of the differential amplifier DAV by the voltage gain A of the differential amplifier DAV, and indicates an unbalanced voltage component.
In a process of manufacturing the above-discussed magnetic sensor IC, deviation of electrode size of the Hall sensor Hs, etc., may usually occur due to dispersion in a photo etching process and a diffusion process, etc. Whereby, the unbalanced voltage V Hoff of the Hall sensor Hs is dispersed. Further, due to the dispersion in the photo etching process and the diffusion process, etc., the input offset voltage V Aoff of the differential amplifier DAV is also dispersed.
In the prior art magnetic sensor IC shown in FIG. 1, an amount of dispersion of the unbalanced voltage V Hoff of the Hall sensor Hs and an amount of dispersion of the input offset voltage V Aoff of the differential amplifier DAV are respectively multiplied by the voltage gain A of the differential amplifier DAV. Therefore, the output voltage Vout1 is dispersed. Accordingly, in the prior art magnetic sensor IC, there is a problem that it is difficult to use for measuring a magnetic field with high precision.
Further, the large dispersion of the unbalanced voltage component may prevent a magnetic sensor IC of high-sensitivity from being produced.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a sensor IC which has high sensitivity. Dispersion occurring in an output voltage of the sensor IC may be reduced. This permits the disadvantages described above to be eliminated.
The object described above is achieved by a sensor IC generating a voltage according to magnetic flux density of an applied magnetic field, the sensor IC comprising: a plurality of Hall sensors having an identical shape formed adjacent to each other in a semiconductor chip, each of the Hall sensors generating a sensor output voltage which includes a Hall output voltage component in proportion to the magnetic flux density; a plurality of differential amplifiers having an identical formed adjacent to each other in the semiconductor chip, each of the differential amplifiers multiplying the sensor output voltage produced from a corresponding one of the Hall sensors by a given gain; and a summing circuit summing output signals produced from the plurality of differential amplifiers.
According to the above-discussed sensor IC, sensitivity for the magnetic flux density may be increased n times of a prior art sensor IC which is constructed with a single Hall sensor and a single differential amplifier. Further, since in a configuration of the sensor IC according to the present invention, voltages in unbalanced components occurring due to both unbalanced voltages of the Hall sensors and input offset voltages of the differential amplifiers are substantially averaged, a standard deviation of the voltage of the unbalanced components causing dispersion of the output voltage may be reduced to 1/√n of that of the prior sensor IC.
Therefore, a highly sensitive sensor IC with small dispersion of the output voltage may be constructed.
The object described above is also achieved by the sensor IC mentioned above, wherein the sensor IC further comprises a waveform-shaping circuit comparing an output voltage of the summing circuit with a reference voltage and converting a two level digital signal.
According to the above-discussed sensor IC, when the magnetic flux density of the magnetic field to be detected is larger than a given threshold level, the waveform-shaping circuit produces an output signal of a H level or a L level. Since in the sensor IC according to the present invention, the sensitivity for the magnetic flux density may be increased and the dispersion of the input voltage to the waveform-shaping circuit may be reduced, the sensor IC can determine whether the magnetic flux density is larger than the given threshold level with high sensitivity and high precision.
The object described above is also achieved by a sensor IC generating a voltage according to applied pressure, the sensor IC comprising: a plurality of semiconductor pressure sensors having an identical shape formed adjacent to each other in a semiconductor chip, each of the sensors generating a sensor output voltage which includes a detected voltage component in proportion to the applied pressure; a plurality of differential amplifiers having an identical circuit formed adjacent to each other in the semiconductor chip, each of the differential amplifiers multiplying the sensor output voltage produced from a corresponding one of the semiconductor pressure sensors by a given gain; and a summing circuit summing output signals produced from the plurality of differential amplifiers.
Further, according to the above-mentioned sensor IC, sensitivity for the applied pressure may be increased n times that of a prior art sensor IC which is constructed with a single semiconductor pressure sensor and a single differential amplifier. Further, since in a configuration of the sensor IC according to the present invention, voltages in unbalanced components occurring due to both unbalanced voltages of the semiconductor pressure sensors and input offset voltages of the differential amplifiers are substantially averaged, a standard deviation of the voltage of the unbalanced components causing dispersion of the output voltage may be reduced to 1/√n of that of a prior sensor IC.
Therefore, a high-sensitive sensor IC with small dispersion of the output voltage may be constructed.
Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic diagram of a prior art magnetic sensor IC;
FIG. 2 shows a schematic diagram of a first embodiment of a magnetic sensor IC according to the present invention;
FIG. 3 shows a schematic diagram of a second embodiment of a magnetic sensor IC according to the present invention; and
FIG. 4 shows a schematic diagram of a third embodiment of a pressure sensor IC according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First, a description will be given of a first embodiment of a sensor IC according to the present invention, by referring to FIG. 2. FIG. 2 shows a schematic diagram of the first embodiment of a magnetic sensor IC according to the present invention. A magnetic sensor IC 11 shown in FIG. 2 is constructed with n Hall sensors Hs1 to Hsn, n differential amplifiers DA1 to DAn, and load resistors Rc1, Rc2 (current addition circuit), which are formed on the same semiconductor chip. The magnetic sensor IC 11 may be formed by using, for example, a silicon-bipolar process.
In the semiconductor chip of the magnetic sensor IC 11, the n Hall sensors Hs1 to Hsn having the same shape are formed close, i.e., adjacent, to each other. In the semiconductor chip, the n differential amplifiers DA1 to DAn having the same pattern and the same circuit are formed close, i.e., adjacent, to each other. Further, in the semiconductor chip, the load resistors Rc1, Rc2 having the same shape and the same value are formed close, i.e., adjacent, to each other.
The Hall sensors Hs1 to Hsn are provided with a power source voltage Vcc, and are operative with a constant voltage. A sensor output voltage produced from the Hall sensor Hs1 is given by the sum of an unbalanced voltage V Hoff1 in the Hall sensor Hs1 and a product (V HO1 .B) of sensitivity V HO1 of the Hall sensor Hs1 and magnetic flux density B of a magnetic field applied to the magnetic sensor IC 11.
In the same way the Hall sensor Hs1, sensor output voltages produced from the Hall sensors Hs2 to Hsn are respectively given by sums of unbalanced voltages V Hoff2 to V Hoffn in the Hall sensors Hs2 to Hsn and products ((V HO2 .B) to (V HOn .B)) of sensitivity V HO2 to V HOn of the Hall sensors Hs2 to Hsn and the magnetic flux density B of the magnetic field applied to the magnetic sensor IC 11.
The sensor output voltages of the Hall sensors Hs1 to Hsn are respectively provided to input terminals of the corresponding differential amplifiers DA1 to DAn. The differential amplifier DA1 is constructed with transistors Q11, Q21, a current-feedback resistor R E1 , and constant current sources J11, J21. Each of the differential amplifiers DA2 to DAn has the same configuration. Between collectors of the transistors Q11 to Q1n, Q21 to Q2n and the power source voltage Vcc, the load resistors Rc1, Rc2 are respectively connected in common.
Output currents Ic11 to Ic1n, and Ic21 to Ic2n of the differential amplifiers DA1 to DAn are respectively summed to each other by the load resistors Rc1, Rc2, and are produced as an output voltage Vout2 between output terminals T1 and T2.
In the above configuration, a voltage V1 of the output terminal T1 and a voltage V2 of the output terminal T2 are respectively represented by the following equations (3) and (4).
V1=Vcc-Rc1.(Ic11+. .+Ic1n) (3)
V2=Vcc-Rc2.(Ic21+. .+Ic2n) (4)
Therefore, the output voltage Vout2 of the magnetic sensor IC 11 is shown in the following equation (5). ##EQU1##
In the first embodiment, values of the load resistors Rc1, Rc2, the current-feedback resistors R E1 to R En , bias currents I11 to I1n generated in the current sources J11 to J1n, and bias currents I21 to J2n generated in the current sources J21 to J2n are adjusted so that a voltage gain of each of the differential amplifiers DA1 to DAn could be a value A, where Rc1=Rc2, R E1 =..=R En , I 11 =I 21 =..=I 1n =I 2n .
In the above conditions, the output voltage Vout2 of the magnetic sensor IC 11 is given by the following equation (6). ##EQU2## where: A: voltage gain of the differential amplifiers DA1 to DAn,
V HO1 to V HOn : sensitivity of the Hall sensors Hs1 to Hsn,
B: magnetic flux density of a magnetic field applied to the magnetic sensor IC,
V Hoff1 to V Hoffn : unbalanced voltages in the Hall sensors Hs1 to Hsn, and
V Aoff1 to V Aoffn : input offset voltages of the differential amplifiers DA1 to DAn.
In the equation (6), the first term indicates a Hall output voltage component when the magnetic flux density B is applied to the magnetic sensor IC 11. The second term of the equation (6) indicates an unbalanced voltage component given by sums of the unbalanced voltages V Hoff1 to V Hoffn in the Hall sensors Hs1 to Hsn and the input offset voltages V Aoff1 to V Aoffn of the differential amplifiers DA1 to DAn, the sums being multiplied with the voltage gain A of the differential amplifiers DA1 to DAn.
Since the n Hall sensors Hs1 to Hsn have the same shape and are formed close to each other in the same semiconductor chip, the n Hall sensors Hs1 to Hsn may have the same physical characteristics. Therefore, sensitivity V HO1 to V HOn of the Hall sensors Hs1 to Hsn may be substantially equal to each other. The above situation is represented as follows:
V.sub.HO1 ≈V.sub.HO2 ≈. .≈V.sub.HOn =V.sub.HO(7)
Substituting the equation (7) to the equation (6), the following equation (8) is obtained. ##EQU3## where n is the number of Hall sensors and the number of differential amplifiers.
In the equation (8), the first term indicates the Hall output voltage component when the magnetic flux density B is applied to the magnetic sensor IC 11. The following equation (9) given by dividing the first term by the magnetic flux density B indicates sensitivity K2 of the magnetic sensor IC 11.
K2=A.V.sub.HO.n (9)
A ratio of the sensitivity of the magnetic sensor IC 11 according to the present invention indicated by the equation (9) to the sensitivity of the prior art magnetic sensor IC 21 indicated by the equation (2) is obtained by dividing the equation (9) by the equation (2) as follows:
A.V.sub.HO.n/(A.V.sub.HO)=n (10)
The equation (10) shows that the sensitivity of the magnetic sensor IC 11 shown in FIG. 2 is n times that of the prior art magnetic sensor IC 21 shown in FIG. 1.
In general, it is known that when devices or circuits have the same shapes in the same semiconductor chip, electrical characteristics of the devices or circuits for a large number of semiconductor chips have a normal distribution.
When a standard deviation of a population of the normally-distributed electrical characteristics is represented by σ 0 and when n devices or n circuits are connected in parallel, a standard deviation σ of the electrical characteristics of the n devices or the n circuits is given by the following equation (11). ##EQU4##
When the n devices or the n circuits are constructed so that their electrical characteristics are substantially averaged, the standard deviation σ of the electrical characteristics of the devices or the circuits may also be represented by the above equation (11) in the same way that the n devices or the n circuits are connected in parallel.
In the prior art magnetic sensor IC 21 shown in FIG. 1, a single Hall sensor Hs and a single differential amplifier DAV are used. Therefore, in the population of a large number of semiconductor chips of the magnetic sensor IC 21, when a standard deviation of the unbalanced voltage V Hoff of the Hall sensor Hs is represented by σ HO , and when a standard deviation of the input voltage V Aoff of the differential amplifier DAV is represented by σ AO , a standard deviation σ 1 of the voltage in the unbalanced component included in the output voltage Vout1 of the magnetic sensor IC 21 is represented by the following equation (12) by using the equation (1). ##EQU5##
On the other hand, in the magnetic sensor IC 11 of the first embodiment, in the second term of the above-mentioned equation (8), the n unbalanced voltages V Hoff1 to V Hoffn of the Hall sensors Hs1 to Hsn are summed to each other, and the n input offset voltages V Aoff1 to V Aoffn of the differential amplifiers DA1 to DAn are summed to each other.
Therefore, the magnetic sensor IC 11 shown in FIG. 2 indicates configurations that the n unbalanced voltages V Hoff1 to V Hoffn of the Hall sensors Hs1 to Hsn are substantially averaged, and the n input offset voltages V Aoff1 to V Aoffn of the differential amplifiers DA1 to DAn are substantially averaged.
Accordingly, in the population of a large number of semiconductor chips of the magnetic sensor IC 11, when a standard deviation of each of the unbalanced voltages V Hoff1 to V Hoffn of the Hall sensors Hs1 to Hsn is represented by σ HO , a standard deviation σ H of the unbalanced voltage of the Hall sensor, in a case where the unbalanced voltage component of the Hall sensor included in the output voltage Vout2 of the magnetic sensor IC 11 is converted to the unbalanced voltage of one Hall sensor, is given by the following equation (13) using the equation (11). ##EQU6##
In the same way, in the population of a large number of semiconductor chips of the magnetic sensor IC 11, when a standard deviation of each of the input offset voltages V Aoff1 to V Aoffn of the differential amplifiers DA1 to DAn is represented by σ AO , a standard deviation σ A of the input offset voltage, in a case where the input offset voltage component of the differential amplifier included in the output voltage Vout2 of the magnetic sensor IC 11 is converted to the input offset voltage of one differential amplifier, is given by the following equation (14) by using the equation (11). ##EQU7##
In these cases, a standard deviation σ 2 of the voltage in the unbalanced component included in the output voltage Vout2 of the magnetic sensor IC 11 is obtained by using the equations (8), (13), and (14) as follows: ##EQU8##
Dividing the equation (15) by the equation (12), the following equation (16) is obtained. ##EQU9##
In this way, the standard deviation of the voltage in the unbalanced component of the magnetic sensor IC 11 may be reduced to 1/√n that in the magnetic sensor IC 21.
A rate of the Hall output voltage component to the dispersion of the unbalanced component included in the output voltage of the magnetic sensor IC is represented by the following equation (17) for the magnetic sensor IC 21, and is represented by the following equation (18) for the magnetic sensor IC 11. ##EQU10##
When dividing the equation (18) by the equation (17), relative sensitivity of the magnetic sensor IC 11 of the first embodiment to the prior art magnetic sensor IC 21 is obtained, and is represented by the following equation (19). ##EQU11##
Therefore, in the magnetic sensor IC 11 which is constructed with the n Hall sensors Hs1 to Hsn and the n differential amplifiers DA1 to DAn, the sensitivity may be increased n times that of the prior art magnetic sensor IC 21 which is constructed with the single Hall sensor Hs and the single differential amplifier DAV. Further, dispersion of the output voltage in the magnetic sensor IC 11 may be reduced to 1/√n of that in the prior art magnetic sensor IC 21. Moreover, the relative sensitivity, taking the dispersion of the output voltage into account, may be represented by n/√n as shown in the equation (19). Accordingly, a highly sensitive magnetic sensor IC may be constructed.
In this way, since the magnetic sensor IC 11 may have characteristics of high sensitivity and small dispersion of the output voltage, the sensor is usable in applications involving measuring a magnetic field with high precision.
Next, a description will be given of a second embodiment of a magnetic sensor IC according to the present invention, by referring to FIG. 3. FIG. 3 shows a schematic diagram of the second embodiment of the magnetic sensor IC according to the present invention. Elements in FIG. 3 which are the same as those of FIG. 2 are given the same reference numerals.
A magnetic sensor IC 12 shown in FIG. 3 is constructed with n Hall sensors Hs1 to Hsn, n differential amplifiers DA1 to DAn, load resistors Rc1, Rc2 (current addition circuit), a Schmidt trigger circuit Sc, and an output transistor QO, which are formed in the same semiconductor chip.
The Schmidt trigger circuit Sc compares an output voltage Vout2 between the terminals T1 and T2 with a reference voltage, and produces a digital signal having two levels (H level and L level).
When the output voltage of the Schmidt trigger circuit Sc is at the H level, the transistor QO turns on, and when at the L level, the transistor QO turns off. At that time, from a collector (output terminal T3) of the transistor QO, an output signal of two levels, a GND level (L level) and an open level (H level), is obtained.
In this configuration, in the magnetic sensor IC 12, when the magnetic flux density B of the magnetic field to be tested is larger than a threshold value, for example, an H-level output signal is produced.
In the magnetic sensor IC 12, in the same way as the previously-discussed magnetic sensor IC 11, dispersion of the unbalanced component causing dispersion of the output voltage Vout2 between the terminals T1 and T2 may be reduced. Therefore, in the magnetic sensor IC 12, sensitivity may be increased, and precision of the threshold for the magnetic flux density B may also be increased. Accordingly, the magnetic sensor IC 12 is usable for applications involving high precision measurement of a magnetic field.
Next, a description will be given of a third embodiment of a pressure sensor IC according to the present invention, by referring to FIG. 4. FIG. 4 shows a schematic diagram of the third embodiment of the pressure sensor IC according to the present invention. Elements in FIG. 4 which are the same as those of FIG. 2 are given the same reference numerals.
A pressure sensor IC 13 shown in FIG. 4 is constructed with n gage resistor elements (semiconductor pressure sensors) Ps1 to Psn, n differential amplifiers DA1 to DAn, and load resistors Rc1, Rc2 (current addition circuit), which are formed in the same semiconductor chip. The pressure sensor IC 13 may be formed by using, for example, the silicon-bipolar process.
In the pressure sensor IC 13, the gage resistor elements Ps1 to Psn are provided instead of the Hall sensors Hs1 to Hsn of the magnetic sensor IC 11 shown in FIG. 2.
In the semiconductor chip of the pressure sensor IC 13, the n gage resistor elements Ps1 to Psn having the same shape are formed close, i.e., adjacent, to each other, the n differential amplifiers DA1 to DAn having the same pattern and the same circuit are formed close, i.e., adjacent, to each other, and the load resistors Rc1, Rc2 having the same shape and the same value are formed close, i.e., adjacent, to each other. Between collectors of the transistors Q11 to Q1n, Q21 to Q2n and the power source voltage Vcc, the load resistors Rc1, Rc2 are respectively connected in common.
The gage resistor elements Ps1 to Psn are constructed by using the piezo resistance effect of a silicon crystal, and form a bridge circuit of diffusion resistors R P1 to R P4 on a silicon diaphragm. Between output terminals of the gage resistor elements Ps1 to Psn, a detected voltage is generated in proportion to an applied pressure.
In the pressure sensor IC 13, sensor output voltages produced from the gage resistor elements Ps1 to Psn are respectively given by sums of the detected voltages V PO1 .P to V POn .P in proportion to the applied pressure and the unbalanced voltages V Poff1 to V Poffn in the gage resistors elements Ps1 to Psn, where symbols V PO1 to V POn1 represent sensitivity of the gage resistor elements Ps1 to Psn, and a symbol P is the applied pressure.
The sensor output voltages of the gage resistor elements Ps1 to Psn are respectively provided to input terminals of the corresponding differential amplifiers DA1 to DAn. Output currents Ic11 to Ic1n, and Ic21 to Ic2n of the differential amplifiers DA1 to DAn are respectively summed to each other by the load resistors Rc1, Rc2, and are produced as an output voltage Vout3 between output terminals T4 and T5.
In the above configuration, a voltage V4 of the output terminal T4 and a voltage V5 of the output terminal T5 are respectively represented by the following equations (20) and (21).
V4=Vcc-Rc1.(Ic11+. .+Ic1n) (20)
V5=Vcc-Rc2.(Ic21+. .+Ic2n) (21)
Therefore, the output voltage Vout3 of the pressure sensor IC 13 is represented by the following equation (22). ##EQU12##
In this embodiment, values of the load resistors Rc1, Rc2, the current-feedback resistors R E1 to R En , bias currents I11 to I1n generated in the current sources J11 to J1n, and bias currents I21 to J2n generated in the current sources J21 to J2n are adjusted so that a voltage gain of each of the differential amplifiers DA1 to DAn could be a value A, where Rc1=Rc2, R E1 =..=R En , I 11 =I 21 =..=I 1n =I 2n .
In the above conditions, the output voltage Vout3 of the pressure sensor IC 13 is given by the following equation (23). ##EQU13## where V PO =V PO1 ≈V PO2 ≈. .≈V POn ,
A: voltage gain of the differential amplifiers DA1 to DAn,
V PO1 to V POn : sensitivity of the gage resistor elements Ps1 to Psn,
P: pressure applied to the pressure IC, V Ppoff1 to V Poffn : unbalanced voltages in the gage resistor elements Ps1 to Psn, and
V Aoff1 to V Aoffn : input offset voltages of the differential amplifiers DA1 to DAn.
The equation (23) is substantially the same as the equation (8) for the first embodiment.
In the same way as the magnetic sensor IC 11 of the first embodiment, the pressure sensor IC 13 shown in FIG. 4 indicates a configuration in which the n unbalances voltages V Poff1 to V Poffn of the gage resistor elements Ps1 to Psn are substantially averaged, and the n input offset voltages V Aoff1 to V Aoffn of the differential amplifiers DA1 to DAn are substantially averaged.
Therefore, in a population of a large number of semiconductor chips of the pressure sensor IC 13, when a standard deviation of each of the unbalanced voltages V Poff1 to V Poffn of the gage resistor elements Ps1 to Psn are represented by σ PO , a standard deviation σ P of the unbalanced voltage of the gage resistor element, in a case where the unbalanced voltage component of the gage resistor element included in the output voltage Vout3 of the pressure sensor IC 13 is converted to the unbalanced voltage of one gage resistor element, is given by the following equation (24) using the equation (11). ##EQU14##
In the same way, in the population of a large number of semiconductor chips of the pressure sensor IC 13, when a standard deviation of each of the input offset voltages V Aoff1 to V Aoffn of the differential amplifiers DA1 to DAn are represented by σ AO , a standard deviation σ A of the input offset voltage, in a case where the input offset voltage component of the differential amplifier included in the output voltage Vout3 of the pressure sensor IC 13 is converted to the input offset voltage of one differential amplifier, is given by the following equation (25) by using the equation (11). ##EQU15##
In these cases, a standard deviation σ 3 of the voltage in the unbalanced component included in the output voltage Vout3 of the pressure sensor IC 13 is obtained by using the equations (23), (24), and (25) as follows: ##EQU16##
Therefore, in the pressure sensor IC 13 shown in FIG. 4, which is constructed with the n gage resistor elements Ps1 to Psn and the n differential amplifiers DA1 to DAn, the sensitivity may be increased n times that of a pressure sensor IC which is constructed with a single gage resistor element and a single differential amplifier. Further, a standard deviation of the voltage in the unbalanced component causing the dispersion of the output voltage in the pressure sensor IC 13 may be reduced to 1/√n of that in the pressure sensor IC having the single gage resistor element and the single differential amplifier, as indicated in the equation (26).
Accordingly, a high-sensitive pressure sensor IC with small dispersion of the output voltage may be constructed.
In this way, since the pressure sensor IC 13 may have characteristics of high sensitivity and small dispersion of the output voltage, this sensor is usable for applications involving high precision measurement of pressure.
Further, the present invention is not limited to these embodiments, but other variations and modifications may be made without departing from the scope of the present invention.
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A sensor IC generates a voltage according to magnetic flux density of an applied magnetic field. The sensor IC includes a plurality of Hall sensors having an identical shape formed adjacent to each other in a semiconductor chip, each of the Hall sensors generating a sensor output voltage which includes a Hall output voltage component in proportion to the magnetic flux density. The sensor IC further includes a plurality of differential amplifiers having an identical circuit formed adjacent to each other in the semiconductor chip, each of the differential amplifiers multiplying the sensor output voltage produced from a corresponding one of the Hall sensors by a given gain. In the sensor IC, by a summing circuit, output signals produced from the plurality of differential amplifiers are summed.
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TECHNICAL FIELD
[0001] The invention relates to wear protectors for work tools, and more particularly to removable wear protectors for the edge portions of work tools.
BACKGROUND
[0002] Work tools for earthmoving and other jobs have a high wear rate because of the environments in which they work. One example is with respect to buckets on shovels or loaders. The buckets are used to dig and move many different types of materials that abrade even the toughest steels used to make the buckets. Buckets, as well as other work tools, will often have removable ground engaging portions so that high wear parts of the buckets can be protected with replaceable parts. It is economical to do this compared to the cost of replacing or substantially rebuilding a bucket or other work tool.
[0003] One of the high wear areas of a work tool, such as a bucket, is on the sides. As the bucket digs into material, the side plates or bars penetrate the material and are subject to wear. Replaceable protectors are useful to protect the sides themselves and avoid costly wear or damage to the bucket. U.S. Pat. No. 5,088,214, issued to Jones on Feb. 18, 1992 discloses a wing protector removably attached to the bucket to protect it. U.S. Pat. No. 5,852,888, issued Dec. 29, 1998, to Cornelius, discloses another embodiment of such a guard.
[0004] Because of the harsh environment in which such protectors operate, and the need to reduce weight and increase bucket penetration to optimize work efficiency, protector design is important. It is also important to control cost by simplifying design and reducing the time it takes to remove worn protectors and install replacements. The present invention is directed to overcoming one or more of the problems set forth above.
SUMMARY OF THE INVENTION
[0005] In one aspect of the present invention, a work tool has an elongated surface. A protector has a mounting element and a work element. A connector element is fastened along the surface of the working portion and is slidably engaged with the mounting portion. A retainer assembly has a retainer positioned upright to the edge portion through an outer surface of the work element. The retainer assembly holds the protector from sliding relative to the connector element.
[0006] In another aspect of the present invention, a protector has a working element and a mounting element. The working element has an outer surface with an opening. The mounting element has first and second end portions and a central portion. Each of the end portions has a substantially equal length and a lengthwise “T” shaped opening. The central portion has a length at least as great as the length of the end portions. The central portion also defines a cavity that, in cross-section, has a profile larger than the “T” shaped openings.
[0007] In yet another aspect of the present invention, a side protector for a side of a work tool has a working element, a mounting element and a retaining element. The working element has a width substantially equal to a width of a top surface of the side. The mounting element is slidably engageable with a connector element of the side protector. The retaining element has an opening alignable with an opening of the connector when the mounting element is slidably engaged with the connector element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a three quarter view of an illustrative work tool having an embodiment of the present invention installed on the work tool.
[0009] [0009]FIG. 2 is a longitudinal, cross-sectional view along liens A-A of FIG. 1.
[0010] [0010]FIG. 3 is a cross-sectional view along lines B-B of FIG. 2.
[0011] [0011]FIG. 4 is a cross-sectional view along lines C-C of FIG. 2.
[0012] [0012]FIG. 5 is top view of a connector element of the embodiment of FIG. 1 shown mounted to a side of the work tool.
[0013] [0013]FIG. 6 is three-quarter view of an exemplary retainer assembly for the present invention.
[0014] [0014]FIG. 7 is a cross-sectional view taken along lines C-C of FIG. 6.
DETAILED DESCRIPTION
[0015] Referring to FIG. 1, a work tool 10 is shown for a work machine (not shown). In the example to be illustrated, the work tool 10 is a bucket 12 . The bucket 12 is configured for use on, for example, a shovel for mining. It should be understood that the following example with respect to the bucket 12 is for illustration only. The principles of the present invention may be used with respect to a variety of tools and on a variety of machines.
[0016] The bucket 12 has a bottom element 14 , a top element 16 and a back element 18 . A pair of sides 20 , 22 join the bottom element 14 and top element 16 , as well as the back element 18 . Depending upon the design and construction of the bucket 12 , the top, bottom and back elements 14 , 16 , 18 may be formed of a single piece or may be separately welded portions. In any event, the elements 14 , 16 , 18 and sides 20 , 22 together form an enclosure or working portion 24 of bucket 12 . The bucket 12 is capable of penetrating material to be loaded through initial engagement of its bottom element 14 . Material is loaded into and held for dumping with the working portion 24 . Teeth 28 and edge protectors 30 assist in the ability to penetrate the material and are replaceable when they are worn. The bucket 12 is connectable to the work machine through arm or linkage mounts 32 .
[0017] Thus, each side 20 or 22 encloses one end 34 or 36 of the bucket 12 . For convenience further reference will be made principally to the one (first) side 20 of the sides 20 , 22 at end 34 . It should be understood that the other (second) side 22 of the bucket 12 will have similar construction and elements. To the extent such elements of side 22 are illustrated in the figures, each element will have a corresponding reference numeral to that of the first side 20 , but with an “a” following the reference numeral.
[0018] The first side 20 has a side bar 38 that reinforces the side 20 and defines an edge portion 40 of the side 20 . The second side 22 has an associated side bar 38 a and edge portion 40 a . The side bar 38 is of thicker material to offer additional protection from wear for edge portion 40 and adjacent parts of the side 20 which would otherwise be formed of the thinner material forming the rest of side 20 . In one example, the side bars 38 , 38 a may be steel of 60 mm in width, whereas the thinner material of the remainder of sides 20 , 22 may be 20 mm width steel. Side bars 38 , 38 a are typically welded in place as part of the sides 20 , 22 . More specifically, in the embodiment shown, each of the side bars 38 , 38 a is butt welded to a surface 42 , 42 a on the thinner material of side 20 , 22 . A pair of protectors 44 , 44 a , each called a side protector or side bar protector in the embodiment shown, is further provided. Each side bar protector 44 , 44 a is associated with a respective side 20 , 22 .
[0019] Referring now to FIGS. 2 - 6 , an embodiment of the side bar protector 44 with reference to the first side 20 is shown. In FIG. 2, the side bar protector 44 is shown in cross-section along line A-A of FIG. 1. The side bar 38 is shown in elevation. Side bar protector 44 is shown removably attached to edge portion 40 on a surface 46 . The side bar protector 44 has a mounting element 48 and a working element 50 . The mounting element 48 includes first and second end portions 51 , 52 and a center portion 53 . A connector element 54 is fastened or mounted to the side bar 38 . These will be more fully explained through reference to FIGS. 3, 4 and 5 .
[0020] Referring to FIG. 3, a cut-a-way portion of the side bar 38 is shown. Side bar 38 has a width 56 of the edge portion 40 at surface 46 defined between the walls 57 ′, 57 ″ of the side bar 38 . The surface 46 is elongated, generally extending along the length of side 20 (best seen in FIG. 2). With respect to the side 20 , the surface 46 first engages material when the bucket 12 is in use. The connector element 54 is attached or fastened lengthwise along the surface 46 of the side bar 38 . Preferably this attachment is permanent in the sense that it is not readily displaced in order to withstand the punishment of earthmoving or other harsh environments. The attachment may, for example, be accomplished by welds 58 . The construction of the connector element 54 provides for welding in a cutout or opening 60 (shown in detail in FIG. 5). The cutout is shown in two parts 60 ′ and 60 ″, the reason for which will be explained later. In cross-section in FIG. 3, the connector element 54 is “T” shaped or in the form of a dovetail. The “T” 62 has a lower end 64 and an upper end 66 . The lower end 64 has a width that is less than the width of the upper end 66 .
[0021] Referring now to the side bar protector 44 , the working element 50 has an outer surface 70 and a width 72 . The working element 50 engages material during bucket 12 use. The width 72 represents the overall width of the side bar protector 44 . This width 72 is preferably substantially the same as the width 56 of the side bar 38 . The outer surface 70 is preferably curvilinear across most of its section, with ends 74 ′, 74 ″ truncated. The overall shape of the outer surface 70 and size of the working element 68 facilitates the function of the side bar protector 44 , as will be explained.
[0022] The mounting element 48 is of a construction or shape sufficient to be slidably engageable with the connector element 54 . The protector 44 has an inner surface 76 that helps define the shape of the mounting element 48 for such engagement. Referring more particularly to FIG. 2, the first and second end portions 50 , 51 are at least partly formed in a “T” or dovetail 82 complementary to the shape of the “T” 62 . The “T” 82 is defined by a part 76 ′ of the inner surface 76 , as are two end surfaces 80 ′, 80 ″. When protector 44 is in position, the end surfaces 80 ′, 80 ″ will be immediately adjacent or touching the surface 46 of the side bar 38 . Thus, the complementary “T” or dovetail also has lower 84 and upper 86 ends formed by the inner surface 76 . Stress relievers 87 ′, 87 ″ are also shown formed by the inner surface 76 . Inner surface 76 further defines a cone shaped void 88 .
[0023] When assembled, the side bar protector 44 is slidably engaged with the connector element 54 through mating of the “T” configurations 62 , 82 . This mating and the complementary construction of the “T” configurations 62 , 82 is in a manner sufficient to hold the protector 44 from movement relative to the connector element 54 in a direction 89 away from the sides 57 ′, 57 ″ (that is, not lengthwise to surface 42 ). It will be appreciated that this movement away from the sides 57 ′, 57 ″ is generally initiated in response to a force component on the protector 44 that is perpendicular to protector 44 .
[0024] Now referring to FIG. 4, a retainer assembly 90 is shown. The retainer assembly 90 provides means for restraining the protector 44 with respect to the side bar 38 . In this case, retention refers to restraining the movement of the side bar protector 44 relative to the connector element 54 (and thus the side bar 38 ) in a direction 91 (FIG. 2) along the surface 42 . In FIG. 4, this lengthwise direction 91 is in and out of the page. The retainer assembly 90 includes a barrel 92 and a retainer, shown as a stud, 94 . The retainer assembly 90 is associated with a retainer portion 95 of the protector 44 when the protector 44 is assembled on side 20 .
[0025] The center portion 53 can be seen in FIG. 2 and FIG. 4 to be free of any “T” shaped opening that will engage with the “T” 62 of connector element 54 . An opening 96 extends through the working element 50 from the outer surface 70 to a second part or portion 76 ″ of the inner surface 76 . Opening 96 opens into cavity 97 defined in and by center portion 53 , in particular by part 76 ″ of the inner surface 76 . Extending inwardly from the outer surface 70 , the opening 96 is shown with cylindrical walls 98 . The opening 96 and cavity 97 together represent retainer portion 95 to facilitate lengthwise retention of the connector element 54 with protector 44 . In other embodiments, the opening 96 may be tapered inwardly to permit easier clean out of material that becomes packed in the opening 96 during use of the bucket 12 . Other configurations may also be used. Adjacent the inner surface portion 76 ″, the opening 96 opens up to accommodate the barrel 92 . In this embodiment, the inner surface portion 76 ″ adjacent opening 96 has step 100 defining a diameter larger than that of opening 96 and then continues with cylindrical walls 102 to an inner end portion 104 . Cylindrical walls 102 define a larger diameter than cylindrical walls 98 and step 100 .
[0026] The cavity 97 , in the cross-section of FIG. 4, defines a profile or area larger than the “T” 82 of the connector element 54 . Thus, the profile of the cavity will typically also be greater than the profile of the “T” 62 (shown in FIG. 3). Additionally, the cavity 97 profile is increased by the area defined by step 100 (shown in two parts, 100 ′, 100 ″). The “enlarged” profile provides the situation where the retainer element 95 will be free of any engagement or interference with the “T” 82 of the connector element 82 when the protector 44 may be slid across the connector element 54 .
[0027] Referring to FIGS. 6 and 7, the retainer assembly 90 is shown in more detail. Stud 94 has a head portion 106 that has walls 108 defining a lesser diameter than walls 98 of opening 96 . The stud 94 tapers at a middle portion 110 and has a threaded bottom portion 112 . In other embodiments, the stud 94 may use a retention means other than threads, so long as it is able to engage with barrel 92 . The head portion 106 shown has a socket portion 113 to fasten or unfasten the stud 94 . Different shapes may include a hex head or other structure by which to engage the stud. The stud 94 may also be of different shapes, such as a single diameter head portion.
[0028] The barrel 92 has an opening 114 of a shape or construction sufficient for stud 94 to seat or mate and to limit further movement of the stud 94 into the barrel 92 . Thus, barrel 92 will have walls 116 that have the same taper as the middle portion 110 of the stud 94 . The barrel 92 also has a threaded portion 118 to threadably engage with bottom portion 112 of stud 98 . A complementary step 119 to step 100 is also shown in FIGS. 6 and 7. The step 119 is divided into two step portions 119 ′, 119 ″ that are parallel to one another on opposite sides of barrel 92 .
[0029] Referring now particularly to FIGS. 2 and 5, the preferred arrangement of the connector element 54 and protector 44 will be further discussed. In FIG. 5, the connector element 54 is shown in top view on the surface 46 of side bar 38 . The connector element 54 has two identical portions 54 ′, 54 ″ that are connected along a central axis 120 . In this embodiment, the identical portions 54 ′, 54 ″ are castings welded together. The connector element 54 is also symmetrical about a longitudinal axis 122 oriented lengthwise down surface 46 . Located at the intersection of the central and longitudinal axes 120 , 122 is an opening 124 sized to receive barrel 92 . The opening 124 passes through the full width of connector element 54 and, when the connector element 54 is welded to the side bar 38 , opens onto the surface 42 . Opening 124 and opening 96 are positioned in the connector element 54 and protector 44 , respectively, so as to be alignable one with the other when the connector element 54 and protector 44 are assembled.
[0030] Connector element 54 further has the previously described opening 60 . The opening 60 is in two parts 60 ′, 60 ″, one each being located in the identical side portions 54 ′, 54 ″. The openings 60 ′, 60 ″ provide a space for welding the connector element 54 to the side bar 38 . As shown, welds 58 ′, 58 ″ are made along edges 126 ′, 126 ″ of the openings 60 ′, 60 ″ and on the surface 42 of the side bar 38 .
[0031] The dovetail or “T” 62 is also shown in two parts 62 ′, 62 ″ in first and second end portions 128 ′, 128 ″ of connector element 54 . Each part 62 ′, 62 ″ extends an equal length “L” in its respective end portion 128 ′, 128 ″ of the connector element 54 . As discussed, a portion 130 (length L′) of the connector element 54 is free from having the dovetail or “T” configuration. In FIG. 2, it can be seen that the dovetail or “T” 82 of the side bar protector 44 is similarly in two parts 82 ′, 82 ″. These parts 82 ′, 82 ″ (in effect, openings) represent a portion of “T” 82 and each have a length L″ sufficient to permit them to engage with the parts 62 ′, 62 ″, respectively. Engagement of the parts 82 ′, 82 ″ is preferably substantially along the entire length L of parts 62 ′, 62 ″. Thus length L is preferably substantially equal to length L″.
[0032] Industrial Applicability
[0033] The side bar protector 44 or 44 a provides substantial protection to the side bar 38 or 38 a and is replaceable when worn. This is preferable to replacing a work tool 10 such as a bucket 12 or rebuilding the work tool 10 to repair worn sides 20 , 22 . In the embodiments illustrated, the use of connector element 44 or 44 a , as well as the other aspects described, provide for a side bar protector 54 or 54 a that is of substantially equal width to the side bar 38 . This provides weight reduction and less resistance of the bucket 12 when digging into material.
[0034] To assemble, the side bar protector 44 is mounted to the connector element 54 previously welded to the side bar 38 . This is accomplished by placing one of the parts 82 ′ or 82 ″ of “T” 82 over the center portion 130 of the connector element 54 . In other words, one of the parts 82 ′, 82 ″ of “T” 82 is placed in the central portion 130 . Prior to this, however, barrel 92 is placed in opening 96 . Opening 96 restrains barrel 92 in position while the side protector 44 is mounted. When positioning barrel 92 , steps 19 ′, 119 ″ are aligned parallel with longitudinal axis 122 .
[0035] With one part 82 ′, 82 ″ in position in central portion 130 , the side bar protector 44 is then slid along the connector element 54 to engage with and along the dovetail or “T” parts 62 ′, 62 ″ to interlock the “T” 82 , 82 ″ parts therewith. The side bar protector 44 is slid until opening 96 aligns with opening 114 in barrel 92 . With the steps 119 ′, 119 ″ aligned along axis 122 , the dovetail 82 of the side bar protector 44 slides without interference across or over barrel 92 . It will be appreciated that the length L′ of central portion 130 is at least as long as length L″ of the dovetail of the side bar protector 44 . Preferably it is slightly longer to permit one of the dovetail parts 62 ′ or 62 ″ to be easily placed over portion 130 to initiate mounting.
[0036] Referring to FIG. 2, the preferred assembly accommodates a weld joint (such as at 132 ) made when fabricating side 20 . Because the connector element 54 and protector 44 do not extend down the side 20 beyond surface 42 , this arrangement tends to eliminate interference such a weld joint might otherwise cause.
[0037] Once the connector element 54 and side bar protector 44 are in the proper position relative to one another, stud 94 is positioned in opening 114 of the barrel 92 and tightened. Thus, stud 94 as configured assumes an upright or a generally perpendicular orientation to surface 42 through engagement with barrel 92 . The barrel 92 is constrained from rotation and from removal through opening 96 by interference of steps 119 ′, 119 ″ with inner surface 76 at step 100 . Stud 94 further constrains the relative movement of side bar protector 44 relative to connector element 54 in direction 89 . This occurs through interference of head portion 106 of stud 94 with walls 98 of opening 96 in side bar protector 44 .
[0038] The symmetrical construction of the side bar protectors 44 , 44 a and connector elements 54 , 54 a provide significant benefit. Typically, the bottom one-third to one-half of a side bar protector 44 that is closest to the bottom element 14 will have the highest wear. When worn, the stud 94 can be removed. The side bar protector 44 is then removed, turned around, and installed with the opposite unworn or lesser worn portion 128 ′ or 128 ″ re-installed toward the bottom element 14 . The use of two separate, but identical parts 54 ′, 54 ″ (such as illustrated in FIG. 5) to construct the connector element 54 also reduces cost in manufacture. Similarly the side bar protectors 44 , 44 a could be so constructed. Of course, constructions other than the symmetrical or “two part” part embodiment illustrated may be used.
[0039] From FIG. 1 it can be seen that the side bar 38 is essentially straight. This accommodates easier fabrication and mounting of the side bar protector 44 . However, the side bar 38 may also be curvilinear. In such instances, the connector element 54 and protector 44 would preferably have a similar curvilinear shape. In practice, a tolerance of about 0.7 mm between the dovetail elements of the protector 44 and connector element 54 has proven adequate. Depending upon the application, construction of the particular embodiment of the side bar protector for that application, and other needs, the tolerance may need to be changed. Other constructions and orientations may be used.
[0040] The embodiments illustrated above and in the drawings have been shown by way of example. There is no intent to limit the invention to the exemplary forms disclosed. All modifications, equivalents and alternatives falling within scope of the appended claims are intended to be covered.
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Work tools, such as buckets of earthmoving machines, have a high wear rate from moving material or other activities. It is advantageous to provide replaceable wear protectors that are sacrificed to reduce or eliminate the need to repair or rebuild the work tools themselves. It is also important to provide a wear protector that is readily installed at the job site and can be securely, but simply retained in place. And the wear protector should not overly affect the operation of the work tool, such as through excess weight, resistance to material penetration or the like. Provided is a wear protector utilizing a connector element fastened to the work tool and a protector slidably engageable with the connector element. A simplified retainer assembly holds the protector in place on the connector element. The wear protector accommodates a compact design to address the problems described.
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[0001] This nonprovisional application is a continuation of International Application No. PCT/EP2013/003796, which was filed on Dec. 16, 2013, and which claims priority to German Patent Application No. 10 2013 000 030.0, which was filed in Germany on Jan. 4, 2013, and which are both herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a fastening system for built-in shower heads.
[0004] 2. Description of the Background Art
[0005] Built-in shower heads, which are intended for installation in suspended ceilings or in walls, are known. In known ceiling-mount shower heads, the hydraulic connection between the water inlet of the built-in shower head and the house connection line typically also serves to mechanically connect the built-in shower head to the water-carrying structure. Moreover, large-size ceiling-mount shower heads require connection geometries with very large dimensions in order to be able to accommodate the weights that arise as well as dynamic loads. An additional disadvantage is that the position of the ceiling-mount shower head is also determined largely by the position of the supply pipe.
[0006] Moreover, in comparison to designs that have hitherto been customary, some modern built-in shower heads have significantly higher weights. Prior art fastening systems are increasingly stretched to their limits on account of the higher weights.
SUMMARY OF THE INVENTION
[0007] It is therefore an object of the present invention to solve the problems arising from the prior art, and in particular to specify a fastening system that ensure easy assembly and secure retention, even for very heavy built-in shower heads. Moreover, the faucet should be economical to produce and must be reliable.
[0008] In an exemplary embodiment, an object is attained by a fastening system that is distinguished by the fact that the shower head housing is connected to a transmission device with an input side and an output side that converts a first motion at the input side into a lifting motion in the direction of installation at the output side, and the output side is connected to the wall or ceiling by a fastener. The use of a transmission device makes it possible to generate very high fastening forces at the output side of the transmission device with relatively small actuating forces at the input side of the transmission device. This is achieved through reduction of the motion at the input side relative to the lifting motion at the output side. In addition to the force amplification achieved through the reduction, the transmission device can also achieve a redirection, so that the motion at the input side is entirely different from the lifting motion required for fastening the built-in shower head. The lifting motion here can correspond to a motion that the built-in shower head makes on the way to the installed position. As an example, this can be a cutout in the wall or ceiling, with the lifting motion in this case taking place in the perpendicular direction, which is to say at right angles to the wall or ceiling. In the case of a ceiling, the lifting motion thus corresponds to the vertical. Due to the use of the transmission device and the redirection, even especially heavy variants of built-in shower heads can thus be fastened securely, since the high holding forces are applied by the transmission device. Moreover, installation is facilitated since the motion at the input side can be oriented in such a manner that it is especially easy for the installer to perform.
[0009] To this end, the first motion can be a rotary motion. An installer can carry out such a rotary motion in an especially easy manner by, for example, a screwdriver, hex wrench, or electric screwdriver.
[0010] In addition, to simplifying the installation it is preferred for the fastener to comprise at least one hook and at least one associated catch. The embodiment in which the hook is located at the output side of the transmission device and executes the lifting motion is especially preferred here. The hook can engage a catch on the wall or ceiling side in an undercut manner for the purpose of fastening. For its part, the catch can be implemented in an especially simple manner as a ring, eye, or opening in a sheet metal part, which in each case is attached to the wall or ceiling. It is especially economical and simple for the fastener to have a sheet metal angle that is attached to the ceiling and of a hook attached to the transmission device that engages at least one opening of the stationary sheet metal angle.
[0011] It is additionally advantageous for safety when especially heavy built-in shower heads are used for an additional securing device to be provided that acts in the event of unintentional release of the fastener or transmission device. It is especially beneficial here if the additional securing device can be implemented as a safety cable that is securely attached on one end to the built-in shower head, and on the other end is securely attached to the ceiling. The length of the safety cable is dimensioned such that it permits the lifting motion required for installation. During installation, the safety cable can then be installed at both ends with the built-in shower head still in the lowered state, to subsequently be completely enclosed by the built-in shower head after the lifting motion has taken place. In this way, the safety cable is fully enclosed and is no longer visible from outside.
[0012] In addition, it is advantageous for the first motion to be a rotary motion whose axis of rotation is oriented in the direction perpendicular to the lifting motion. With a rotary motion whose axis of rotation is essentially at right angles to the lifting motion, installation can be carried out from one side of the built-in shower head. Only lateral openings are necessary for this purpose, for example in order to act on the input side of the transmission device with a tool or other manipulator. The openings can thus be placed on the side of the built-in shower head and hence outside the directly visible area. Even very small openings are sufficient here, for example in order to act on a screw with a hex key, so that the area of the visible surfaces is only marred by very small openings. In addition to an exact right-angle orientation, the axis of rotation can also be inclined slightly relative to the ceiling or wall, for example by 5° to 20°, achieving a larger spacing that facilitates installation using tools.
[0013] In an embodiment, provision is additionally made for the transmission device to have at least one pivoted lever that is supported so as to pivot about a pivot axis, wherein a first side of the pivoted lever is designed as part of the fastener and a second side has a slotted link with at least one sliding block guided therein. While the first side is implemented as a hook, for example, which executes the lifting motion during advance of the transmission device, the opposite end of the pivoting lever can be driven by a linear motion of the sliding block, which is capable of moving inside the slotted link and relative to the pivoted lever. It should be noted here that it suffices on the first side of the pivoted lever if a hook attached thereto carries out only an approximation of a lifting motion. It is not strictly necessary for a linear motion of the hook to be implemented exactly. Through the use of a slotted link with a sliding block, the redirection of the first motion at the input side of the transmission device can be implemented at the second side of the transmission device in a wide variety of directions. Consequently, this produces an especially high degree of freedom in the design of the transmission device.
[0014] It has proven especially beneficial in this context, particularly for ceiling mounting, for the pivot axis of the pivoted lever to lie in, for example, a horizontal plane. In the case of wall mounting, a vertical plane parallel to the wall would then be provided instead of the horizontal plane.
[0015] In addition, the sliding block can be guided by a guide along a path of motion, for example, in a horizontal direction, and to be movable by the rotary motion. In the case of ceiling mounting, the path of motion can thus be parallel to the ceiling, and the sliding block can be moved in alternation along this path of motion by suitable rotation. In consequence, the pivoted lever is then rotated about the pivot axis by the guided motion of the sliding block. This is achieved in that during this motion the sliding block moves relative to the slotted link provided in the pivoted lever. In addition to the described embodiment with a slotted link located in the pivoted lever, an opposite principle can also be used. In that case, provision is made to move a slotted link relative to the pivoted lever, and the sliding block is implemented on the pivoted lever. In addition to the exemplary horizontal orientation of the path of motion that has been described, this orientation can also be inclined in a range from 0° to 30° relative to the ceiling or wall. Simplified access is achieved for a tool applied at an angle, for example, especially through pivoting downward away from a ceiling. In particular, an inclination of 5° or 10°, for example, is suitable for creating improved access for execution of the first motion via a tool, since an additional spacing from the ceiling is created in a lateral region of the built-in shower head.
[0016] In addition, it has proven to be of value for the sliding block to have an internal thread that stands in engagement with a rotatable screw that is fixed in the longitudinal direction. Such a screw can have a tool engagement implemented as a hex socket, for example, and is attached to the built-in shower head such that it can rotate while at the same time being fixed in the longitudinal direction. Depending on the embodiment selected, the sliding block or the slotted link, each of which is provided with an internal thread and stands in engagement with the screw, can be moved along the path of motion by the screw. Moreover, an especially large reduction can be achieved through the use of the screw, making even heavy shower heads easy to install.
[0017] Further, an object of the invention can be attained with a built-in shower head having a fastening system since this ensures especially simple installation and secure retention in the installed position.
[0018] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
[0020] FIG. 1 is an oblique view of a built-in shower head according to an exemplary embodiment of invention with a fastener;
[0021] FIG. 2 is an enlarged partial view of the built-in shower head from FIG. 1 ;
[0022] FIG. 3 is a cross-sectional view of the fastening system from FIG. 1 in an open state; and
[0023] FIG. 4 is a cross-sectional view of the fastening system from FIG. 1 in a closed state.
DETAILED DESCRIPTION
[0024] FIG. 1 shows a built-in shower head 1 according to the invention in an oblique view from above. The built-in shower head 1 includes a shower head housing 2 , water-carrier 3 , a water connection 4 , and multiple spray face-plates 5 . Located on each of two opposite sides is a transmission device 6 that converts a first motion 7 at an input side 8 into a lifting motion 9 at an output side 10 of the transmission device 6 . The output side 10 of the transmission device 6 is simultaneously implemented as part of a fastener 11 , which has a hook 12 and a catch 13 . The catch 13 is stamped as an opening in a piece of angled sheet metal 14 . The sheet metal 14 additionally has a hole 15 , where one end of a chain is attached as a securing device 16 . The chain is also connected at its opposite end to the shower head housing 2 . The length of the chain is dimensioned such that during installation the securing device 16 is first attached at both ends in order to subsequently insert the hook 12 in the catches 13 and carry out the lifting motion 9 .
[0025] FIG. 2 shows the transmission device 6 with the securing device 16 , again in an enlarged view. The transmission device 6 has a pivoted lever 17 with a slotted link 18 . Located in the slotted link 18 is a sliding block 19 , which in the embodiment shown is implemented as a stud with a U-shaped sliding body. The pivoted lever 17 is mounted so as to be rotatable about a pivot axis 20 . A screw 21 that is mounted so as to be rotatable and is fixed in the axial and lateral directions is provided for actuating the transmission device 6 . The screw 21 can be rotated by via a screwdriver, not shown, through a tool opening 22 . The screw 21 thus forms the input side 8 of the transmission device 6 , and is actuated through the first motion 7 in the form of a rotary motion.
[0026] The attached figures are used to explain in even greater detail the way the screw 21 interacts with the movable sliding block 19 , which can be moved by a guide 23 in the horizontal direction along a path of motion 24 . It is evident from FIG. 2 that as soon as the sliding block 19 moves away from the pivot axis 20 , a first side of the pivoted lever 17 is moved upward, away from the shower head housing 2 , as a result of the interaction between the sliding block 19 and the slotted link 18 . At the same time, a second side 26 of the pivoted lever 17 is moved downward. The situation shown in FIG. 2 corresponds to a preinstalled state with lowered built-in shower head 1 .
[0027] FIG. 3 shows a cross-sectional view through a transmission device 6 according to the invention in the opened state. The angled sheet metal 14 with the catch 13 is fastened to a ceiling 27 with a fastener. The second side 26 of the hook 12 engages the catch 13 of the sheet metal 14 . The way that the screw 21 can be actuated through the tool opening 22 via a tool is also clearly discernible in this view.
[0028] In the example shown, the screw 21 is implemented as a setscrew with a hex socket. It is also evident in the cross-sectional view that the guide 23 for the sliding block 19 are implemented as a tongue and groove joint. The sliding block 19 is thus guided, and can move along the path of motion 24 .
[0029] Lastly, FIG. 4 shows another embodiment of a fastening system according to the invention in a fully installed state, and consequently in the installed position. The sliding block 19 is moved to the left by the screw 21 , causing the first side 25 of the pivoted lever 17 to move upward toward the ceiling 27 . Due to the simultaneous lowering of the hook 12 on the second side 26 of the pivoted lever 17 , the entire built-in shower head 1 is moved in the direction of the lifting motion 9 toward the ceiling 27 .
[0030] With the present invention, even especially heavy built-in shower heads can be attached to ceilings or walls securely and with little installation effort. Moreover, the external appearance of the built-in shower head 1 is only marred by very small tool openings. In addition to the horizontal orientation of the screw 21 and the tool opening 22 shown, it is also possible to place them inclined by an angle of inclination a so that a tool can be inserted more easily into the tool opening 22 from a position located below the built-in shower head 1 . The angle α between the wall or ceiling and the longitudinal axis of the screw 21 should be between 0° and 45°, preferably between 5° and 30°. This facilitates operability since the grip end of the inserted tool is thus located further from the ceiling 27 , and gives the installer more space for manual installation.
[0031] Lastly, it should be noted that the present invention is not limited to the exemplary embodiments shown. Rather, numerous variations of the claims are possible within the scope of the invention. Thus, for example, other transmission principles can be used within the scope of the present invention in place of the transmission device 6 with a pivoted lever and a sliding block guide. Worm drives and spindle drives, such as are used in car jacks, may be cited here by way of example. Moreover, additional guide(s) that ensure a defined horizontal lifting motion can be provided for lateral installation in a wall.
[0032] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
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A fastening system for installation shower heads for installing in a wall or ceiling, including a shower head housing and water-conductor for connecting at least one water connection to at least one jet creator. The shower head housing is connected to a transmission device having an input side and an output side, which converts a first motion on the input side into a reciprocating motion in the installation direction on the output side, and the output side is connected to the wall or ceiling by a fastener.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to medical devices comprising synergistic combinations of triclosan and chlorhexidine.
[0002] Whenever a medical device comes in contact with a patient, a risk of infection is created. Thus, a contaminated examination glove, tongue depressor, or stethoscope could transmit infection. The risk of infection dramatically increases for invasive medical devices, such as intravenous catheters, arterial grafts, intrathecal or intracerebral shunts and prosthetic devices, which not only are, themselves, in intimate contact with body tissues and fluids, but also create a portal of entry for pathogens.
[0003] A number of methods for reducing the risk of infection have been developed which incorporate anti-infective agents into medical devices, none of which have been clinically proven to be completely satisfactory. Such devices desirably provide effective levels of anti-infective agent during the entire period that the device is being used. This sustained release may be problematic to achieve, in that a mechanism for dispersing anti-infective agent over a prolonged period of time may be required, and the incorporation of sufficient amounts of anti-infective agent may adversely affect the surface characteristics of the device. The difficulties encountered in providing effective anti-microbial protection increase with the development of drug-resistant pathogens.
[0004] One potential solution to these problems is the use of a synergistic combination of anti-infective agents that requires relatively low concentrations of individual anti-infective agents which may have differing patterns of bioavailability.
[0005] Two well known anti-infective agents are chlorhexidine and triclosan. The following patents and patent application relate to the use of chlorhexidine and/or triclosan in medical devices.
[0006] U.S. Pat. No. 4,723,950 by Lee relates to a microbicidal tube which may be incorporated into the outlet tube of a urine drainage bag. The microbicidal tube is manufactured from polymeric materials capable of absorbing and releasing anti-microbial substances in a controllable, sustained, time-release mechanism, activated upon contact with droplets of urine, thereby preventing the retrograde migration of infectious organisms into the drainage bag. The microbicidal tube may be produced by one of three processes: (1) a porous material, such as polypropylene, is impregnated with at least one microbicidal agent, and then coated with a hydrophilic polymer which swells upon contact with urine, causing the leaching-out of the microbicidal agent; (2) a porous material, such as high density polyethylene, is impregnated with a hydrophilic polymer and at least one microbicidal agent; and (3) a polymer, such as silicone, is compounded and co-extruded with at least one microbicidal agent, and then coated with a hydrophilic polymer. A broad range of microbicidal agents are disclosed, including chlorhexidine and triclosan, and combinations thereof. The purpose of Lee's device is to allow the leaching out of microbicidal agents into urine contained in the drainage bag; similar leaching of microbicidal agents into the bloodstream of a patient may be undesirable.
[0007] U.S. Pat. No. 5,091,442 by Milner relates to tubular articles, such as condoms and catheters, which are rendered antimicrobially effective by the incorporation of a non-ionic sparingly soluble antimicrobial agent, such as triclosan. The tubular articles are made of materials which include natural rubber, polyvinyl chloride and polyurethane. Antimicrobial agent may be distributed throughout the article, or in a coating thereon. A condom prepared from natural rubber latex containing 1% by weight of triclosan, then dipped in an aqueous solution of chlorhexidine, is disclosed. U.S. Pat. Nos. 5,180,605 and 5,261,421, both by Milner, relate to similar technology applied to gloves.
[0008] U.S. Pat. Nos. 5,033,488 and 5,209,251, both by Curtis et al., relate to dental floss prepared from expanded polytetrafluoroethylene (PTFE) and coated with microcrystalline wax. Antimicrobial agents such as chlorhexidine or triclosan may be incorporated into the coated floss.
[0009] U.S. Pat. No. 5,200,194 by Edgren et al. relates to an oral osmotic device comprising a thin semipermeable membrane wall surrounding a compartment housing a “beneficial agent” (that is at least somewhat soluble in saliva) and a fibrous support material composed of hydrophilic water-insoluble fibers. The patent lists a wide variety of “beneficial agents” which may be incorporated into the oral osmotic device, including chlorhexidine and triclosan.
[0010] U.S. Pat. No. 5,019,096 by Fox, Jr. et al. relates to infection-resistant medical devices comprising a synergistic combination of a silver salt (such as silver sulfadiazine) and chlorhexidine.
[0011] International Patent Application No. PCT/GB92/01481, Publication No. WO 93/02717, relates to an adhesive product comprising residues of a co-polymerizable emulsifier comprising a medicament, which may be povidone iodine, triclosan, or chlorhexidine.
[0012] In contrast to the present invention, none of the above-cited references teach medical articles comprising synergistic combinations of chlorhexidine and triclosan which utilize relatively low levels of these agents.
SUMMARY OF THE INVENTION
[0013] The present invention relates to polymeric medical articles comprising the anti-infective agents chlorhexidine and triclosan. It is based, at least in part, on the discovery that the synergistic relationship between these compounds permits the use of relatively low levels of both agents, and on the discovery that effective antimicrobial activity may be achieved when these compounds are comprised in either hydrophilic or hydrophobic polymers. It is also based on the discovery that chlorhexidine free base and triclosan, used together, are incorporated into polymeric medical articles more efficiently. Medical articles prepared according to the invention offer the advantage of preventing or inhibiting infection while avoiding undesirably high release of anti-infective agent, for example into the bloodstream of a subject.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention relates to medical articles comprising synergistic combinations of chlorhexidine and triclosan.
[0015] Chlorhexidine may be provided by way of any form, salt or derivative thereof, including but not limited to chlorhexidine free base and chlorhexidine salts such as chlorhexidine diphosphanilate, chlorhexidine digluconate, chlorhexidine diacetate, chlorhexidine dihydrochloride, chlorhexidine dichloride, chlorhexidine dihydroiodide, chlorhexidine diperchlorate, chlorhexidine dinitrate, chlorhexidine sulfate, chlorhexidine sulfite, chlorhexidine thiosulfate, chlorhexidine di-acid phosphate, chlorhexidine difluorophosphate, chlorhexidine diformate, chlorhexidine dipropionate, chlorhexidine di-iodobutyrate, chlorhexidine di-n-valerate, chlorhexidine dicaproate, chlorhexidine malonate, chlorhexidine succinate, chlorhexidine malate, chlorhexidine tartrate, chlorhexidine dimonoglycolate, chlorhexidine monodiglycolate, chlorhexidine dilactate, chlorhexidine di-α-hydroxyisobutyrate, chlorhexidine diglucoheptonate, chlorhexidine di-isothionate, chlorhexidine dibenzoate, chlorhexidine dicinnamate, chlorhexidine dimandelate, chlorhexidine di-isophthalate, chlorhexidine di-2-hydroxynaphthoate, and chlorhexidine embonate. The term “chlorhexidine”, as used herein, may refer to any of such forms, derivatives, or salts, unless specified otherwise. Chlorhexidine salts may be solubilized using polyethylene glycol or propylene glycol, or other solvents known in the art.
[0016] The term triclosan refers to a compound also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether.
[0017] Medical articles that may be treated according to the invention are either fabricated from or coated or treated with biomedical polymer and include, but are not limited to, catheters including urinary catheters and vascular catheters (e.g., peripheral and central vascular catheters), wound drainage tubes, arterial grafts, soft tissue patches, gloves, shunts, stents, tracheal catheters, wound dressings, sutures, guide wires and prosthetic devices (e.g., heart valves and LVADs). Vascular catheters which may be prepared according to the present invention include, but are not limited to, single and multiple lumen central venous catheters, peripherally inserted central venous catheters, emergency infusion catheters, percutaneous sheath introducer systems and thermodilution catheters, including the hubs and ports of such vascular catheters.
[0018] The present invention may be further applied to medical articles that have been prepared according to U.S. Pat. No. 5,019,096 by Fox, Jr. et al.
[0019] The present invention provides, in various alternative non-limiting embodiments, for: (I) compositions which provide a local concentration of chlorhexidine of between 100 and 2000 μg/ml and a local concentration of triclosan of between 250 and 2000 μg/ml; (2) treatment solutions of a polymer comprising between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan, wherein a medical article may be dipped or soaked in the polymer solution; (3) medical articles treated with a treatment solution as set forth in (2) above, and articles physically equivalent thereto (that is to say, articles prepared by a different method but having essentially the same elements in the same proportions); (4) treatment solutions of a polymer comprising between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan; and between 0.5 and 1 percent (preferably 0.75 percent) of silver sulfadiazine, wherein a medical article may be dipped or soaked in the polymer solution; and (5) medical articles treated with a treatment solution set forth in (4) above, and articles physically equivalent thereto (that is to say, articles prepared by a different method but having essentially the same elements in the same proportions). Percentages recited herein refer to percent by weight, except as indicated otherwise.
[0020] In preferred embodiments, the ratio, by weight, of the total amount of anti-infective agent to polymer in the treatment solution is less than 1.5.
[0021] In one particular non-limiting embodiment, the present invention provides for a hydrophilic polymeric medical article (i.e., a medical article fabricated from a hydrophilic polymer) treated by dipping or soaking the article in a treatment solution of a hydrophilic polymer comprising chlorhexidine and triclosan wherein the chlorhexidine and triclosan are present in amounts such that their combination, in the treated article, has effective antimicrobial activity. The terms “treat”, “treated”, etc., as used herein, refer to coating, impregnating, or coating and impregnating a medical article with polymer/anti-infective agent. The term “hydrophilic polymer”, as used herein, refers to polymers which have a water absorption greater than 0.6 percent by weight (and, in preferred embodiments, less than 2 percent by weight; as measured by a 24 hour immersion in distilled water, as described in ASTM Designation D570-81) including, but not limited to biomedical polyurethanes (e.g., ether-based polyurethanes and ester-based polyurethanes, as set forth in Baker, 1987, in Controlled Release of Biologically Active Agents, John Wiley and Sons, pp. 175-177 and Lelah and Cooper, 1986 , Polyurethanes in Medicine, CRC Press, Inc., Fla. pp. 57-67; polyurethanes comprising substantially aliphatic backbones such as Tecoflex™ 93A; polyurethanes comprising substantially aromatic backbones such as Tecothane™; and Pellethane™), polylactic acid, polyglycolic acid, natural rubber latex, and gauze or water-absorbent fabric, including cotton gauze and silk suture material. In a specific, non-limiting embodiment, the hydrophilic medical article is a polyurethane catheter which has been treated with (i.e., dipped or soaked in) a treatment solution comprising (i) between about 1 and 10 percent, preferably between about 2 and 6 percent, and more preferably about 3 percent, of a biomedical polyurethane; (ii) between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and (iii) between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan. In related non-limiting embodiments of the invention, the treatment solution may further comprise silver sulfadiazine, preferably in a concentration of between 0.5 and 1 percent (more preferably 0.75 percent). Section 6, below, presents working examples of embodiments set forth in this paragraph.
[0022] In another particular non-limiting embodiment, the present invention provides for a hydrophilic polymeric medical article treated by dipping or soaking the article in a treatment solution of a hydrophobic polymer comprising chlorhexidine and triclosan, wherein the chlorhexidine and triclosan are present in amounts such that their combination, in the treated article, has effective antimicrobial activity. The term “hydrophobic polymer”, as used herein, refers to a polymer which has a water absorption of less than 0.6 percent and includes, but is not limited to, silicone polymers such as biomedical silicones (e.g., Silastic Type A) or elastomers (e.g., as set forth in Baker, 1987, in Controlled Release of Biologically Active Agents, John Wiley and Sons, pp. 156-162), Dacron, polytetrafluoroethylene (PTFE, also “Teflon”), polyvinyl chloride, cellulose acetate, polycarbonate, and copolymers such as silicone-polyurethane copolymers (e.g., PTUE 203 and PTUE 205 polyurethane-silicone interpenetrating polymer). In a specific, non-limiting embodiment, the medical article is a polyurethane catheter which has been dipped or soaked in a treatment solution comprising (i) between about 1 and 10 percent, preferably between about 2 and 6 percent, and more preferably about 3 percent, of a polyurethane-silicone copolymer; (ii) between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and (iii) between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan. In related non-limiting embodiments of the invention, the treatment solution may further comprise silver sulfadiazine, preferably in a concentration of between 0.5 and 1 percent (more preferably 0.75 percent). Section 7, below, presents working examples of embodiments set forth in this paragraph.
[0023] In another particular non-limiting embodiment, the present invention provides for a hydrophobic polymeric medical article treated by dipping or soaking the article in a treatment solution of hydrophobic polymer comprising chlorhexidine and triclosan, wherein the chlorhexidine and triclosan are present in amounts such that their combination, in the treated article, has effective antimicrobial activity. In a specific, non-limiting embodiment, the medical article is a silicone catheter or a polyvinylchloride catheter which has been dipped or soaked in a treatment solution comprising (i) between about 1 and 10 percent, and preferably about 5 percent, of a silicone polymer; (ii) between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and (iii) between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan. In related non-limiting embodiments of the invention, the treatment solution may further comprise silver sulfadiazine, preferably in a concentration of between 0.5 and 1 percent (more preferably 0.75 percent). In still other related embodiments, a coating of a hydrophobic polymer may be applied over the treated article. Section 8, below, presents working examples of embodiments set forth in this paragraph.
[0024] In another particular non-limiting embodiment, the present invention provides for a hydrophobic polymeric medical article treated by dipping or soaking the article in a treatment solution of hydrophilic polymer comprising chlorhexidine and triclosan, wherein the chlorhexidine and triclosan are present in amounts such that their combination, in the treated article, has effective antimicrobial activity. In a specific, non-limiting embodiment, the medical article is a silicone catheter or Teflon graft which has been dipped or soaked in a treatment solution comprising (i) between about 1 and 10 percent, preferably between about 2 and 6 percent, and more preferably about 3 percent, of a biomedical polyurethane polymer; (ii) between 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; and (iii) between 0.5 and 5 percent, and preferably between 0.5 and 2 percent, of triclosan. In related non-limiting embodiments of the invention, the treatment solution may further comprise silver sulfadiazine, preferably in a concentration of between 0.5 and 1 percent (more preferably 0.75 percent).
[0025] Medical articles prepared according to the invention may be treated on their external surface, internal surface, or both. For example, and not by way of limitation, where the medical article is a catheter, the internal surface and/or external surface of the catheter may be treated according to the invention. For example, where it is desired to treat both internal and external surfaces, an open-ended catheter may be placed in a treatment solution such that the treatment solution fills the catheter lumen. If only the external surface is to come in contact with treatment solution, the ends of the catheter may be sealed before it is placed in the treatment solution. If only the internal surface is to come in contact with treatment solution, the solution may be allowed to pass through and fill the lumen but the catheter is not immersed in the treatment solution.
[0026] Successful treatment of a medical article with a polymer comprising an anti-infective agent may be problematic, particularly where the medical article has a hydrophobic surface. The adherence of the polymer may depend upon (1) the polymeric matrix in which the anti-infective agent is suspended; (2) compatibility (or lack thereof) between the agent-polymeric matrix and the surface of the article; (3) the solvent system; and (4) the thickness of polymer/anti-infective agent desirably applied. Furthermore, the rates of release of various anti-infective agents from diverse polymers may differ. For example, the rate of release of chlorhexidine from a silicone matrix is faster than the rate of release of silver sulfadiazine from the same matrix. In order to compensate for this difference, one potential solution would be to increase the amounts of chlorhexidine and silver sulfadiazine in the matrix. Unfortunately, polymers comprising high levels of chlorhexidine and silver sulfadiazine have been found to adhere poorly to silicone catheters. In order to provide an alternative solution to the problem, two different methods for treating medical articles have been developed: a one-step method, and a two-step method, both of which are set forth below.
[0027] According to the one-step method of the invention, a polymeric medical article may be treated with a solution comprising one or more anti-infective agents, and optionally containing a biomedical polymer, dissolved in one or more solvent(s), wherein the solvent(s) selected are capable of swelling the polymeric medical article to be treated; such a solution is referred to herein as an “impregnating solution”, and the process by which the article is treated with anti-infective agent is referred to as “impregnation”. Suitable solvents include, but are not limited to, tetrahydrofuran (“THF”), dichloromethane, carbon tetrachloride, methanol, ethanol, methyl ethyl ketone, heptane, and hexane, and mixtures thereof. The biomedical polymer may be hydrophilic or hydrophobic, and includes the various polymers set forth above.
[0028] If a hydrophilic polymeric medical article is to be impregnated with chlorhexidine and triclosan, the impregnating solution may, in specific non-limiting embodiments, comprise the following (percentages of solvents in this paragraph being volume/volume): (1) 95% ethanol; (2) 70% ethanol/30% water; (3) 50% ethanol/50% water; (4) 30% reagent alcohol/70% THF containing 2-3% of a biomedical polyurethane; (5) 90% reagent alcohol/10% THF; or (6) 100% reagent alcohol. Preferred soaking times vary between 5 minutes and 1 hour.
[0029] In specific, non-limiting embodiments of the invention, a hydrophilic medical article such as a polyurethane catheter may be impregnated using a solvent mixture of 70-90% ethanol and 10-30% water and chlorhexidine and triclosan for between 10 and 60 minutes. The article may then be dried for 24-48 hours.
[0030] If a hydrophobic polymeric medical article is to be impregnated with chlorhexidine and triclosan, the impregnating solution may, in specific non-limiting embodiments, comprise the following (percentages of solvents in this paragraph being volume/volume): (1) 10% methanol/90% THF; (2) 10% ethanol/90% THF; (3) 30% methanol/70% THF; (4) 30% ethanol/70% THF; (5) 1-5 percent silicone polymer in 10% methanol/90% THF; (6) 1-5 percent silicone polymer in 10% ethanol/90% THF; (7) 1-2 percent polylactic acid in 10% methanol/90% THF; (8) 1-2 percent polylactic acid in 10% ethanol/90% THF; (9) 1-5 percent silicone polymer in 30% methanol/70% THF; (10) 1-5 percent silicone polymer in 30% ethanol/70% THF; (11) 1-2 percent polylactic acid in 30% methanol/70% THF; (12) 1-2 percent polylactic acid in 30% ethanol/70% THF; (13) 1-5 percent silicone polymer in 100% methyl ethyl ketone; and (14) 1-2 percent polyurethane in 30% ethanol/70% THF. For specific examples, see Section 15, below.
[0031] In specific embodiments, the impregnating solution comprises between 0.2 and 10 percent anti-infective agent and between 0.5 and 4 percent biomedical polymer.
[0032] The medical article, or a portion thereof, may be immersed in the impregnating solution to swell, after which the article may be removed and dried at room temperature until all solvent has evaporated and the article is no longer swollen. During the swelling process, anti-infective agent (and small amounts of polymer when present in the impregnating solution) may be distributed within the polymeric substrate of the article; during drying, the anti-infective agent and biomedical polymer (where present) may migrate somewhat toward the surface of the article. After drying, the article may be rinsed in either water or alcohol and wiped to remove any excess anti-infective agent and/or polymer at the surface. This may leave a sufficient amount of anti-infective agent just below the surface of the article, thereby permitting sustained release of the agent over a prolonged period of time. Anti-infective agents which may be incorporated by this process include but are not limited to chlorhexidine, triclosan, silver sulfadiazine, parachlorometaxylene, benzalkonium chloride, bacitracin, polymyxin, miconasole and rifampicin, as well as combinations thereof.
[0033] In preferred, non-limiting embodiments of the invention, synergistic combinations of chlorhexidine and triclosan may be dissolved in a mixture of methanol and tetrahydrofuran to produce an impregnating solution that may be used to render a silicone catheter anti-infective.
[0034] In one specific, non-limiting example, the amount of chlorhexidine may be between 1 and 5 percent and preferably between 1.5 and 2.25 percent of the impregnating solution, and the amount of triclosan may be between 0.5 and 5 percent, and preferably between 0.5 and 2 percent. The resulting impregnating solution may further contain between 1 and 10 percent and preferably between 2 and 4 percent of a biomedical polymer such as a silicone polymer (e.g., Silastic Type A), polyurethane, or polycaprolactone. Specific examples of the one-step method are provided in Section 12 below.
[0035] According to the two-step method of the invention, the one-step method may be used to impregnate a medical article with anti-infective agent, and then the medical article may be dipped into a polymeric solution and dried. This method forms a polymeric coating on the article and further controls the rate of release of anti-infective agent. When the two-step method is practiced, the biomedical polymer may be omitted from the first soaking step. Optionally, an anti-infective agent may further be comprised in the polymeric coating. In a specific, non-limiting example, a silicone catheter may be dipped in a mixture of methanol and tetrahydrofuran containing between about 1 and 5 percent, and preferably between 1.5 and 2.25 percent, of chlorhexidine; between 0.5 and 5 percent and preferably between 0.5 and 2 percent of triclosan; and between 1 and 10 percent, and preferably between 2 and 4 percent, of a biomedical polymer (preferably a silicone polymer such as Silastic Type A) for about 30 minutes, dried, and then dipped in a higher concentration (but less than 10 percent) of biomedical polymer dissolved in a suitable solvent. For example, but not by way of limitation, a coating may be applied using a solution of 30% ethanol/70% THF containing 2-3 percent of a biomedical polyurethane, or a solution of 1-5 percent of Silastic Type A.
[0036] Alternatively, a hydrophilic medical article, such as a polyurethane catheter, may be impregnated with one or more antimicrobial agents and then coated with a polymer.
[0037] Examples of the two-step method are set forth in Sections 8, 16 and 17 below.
[0038] As set forth in Section 17, below, it has further been discovered that when medical articles were treated with mixtures of chlorhexidine free base and triclosan, uptake of chlorhexidine and triclosan was enhanced, and the antimicrobial activity of such articles was improved. While not desiring to be bound to any particular theory, it is believed that chlorhexidine free base and triclosan form a complex with improved solubility. The foregoing effect was observed when chlorhexidine free base and triclosan were combined in a respective molar ratio of 1:2; according to the invention, chlorhexidine free base and triclosan may be dissolved in a solvent or solvent system at chlorhexidine free base: triclosan molar ratios of 1:1 to 1:3. The total weight percent of chlorhexidine free base plus triclosan is between 1 and 10 percent. The chlorhexidine free base and triclosan may be dissolved in a solvent system comprising water, alcohol, or tetrahydrofuran, and mixtures thereof, to produce an impregnating solution. In one specific, non-limiting example of the invention, a 1:2 ratio of chlorhexidine free base and triclosan may be dissolved in a solvent system which is 70 percent tetrahydrofuran and 30 percent reagent alcohol. A medical article, for example, a polyurethane article, may be impregnated with chlorhexidine free base/triclosan by immersing the article in such an impregnating solution so that the medical article swells without losing substantial structural integrity. After impregnation, the article may be dried, and then optionally coated with a polymeric solution, according to the two-step method set forth above.
[0039] Anti-infective medical articles prepared by other methods (e.g., extrusion, casting) but being otherwise substantially the same as articles produced by dipping or soaking, are within the scope of the claimed invention.
5. EXAMPLE
Combinations of Chlorhexidine and Triclosan Exhibit Synergistic Activity in Bacterial Cultures
[0040] Various concentrations of chlorhexidine diacetate (“CHA”) and/or triclosan (“TC”) were dispensed in 1.0 ml trypticase soy broth (“TSB”) containing 20 percent bovine calf serum (“BCS”) and inoculated with 10 7 colony-forming units (“CFU”) of Staphylococcus aureus. After one minute, the cultures were diluted with drug-inactivating medium (1:100 dilution in LTSB drug inactivating medium, which is 5% Tween 80, 2% lecithin, 0.6% sodium oleate, 0.5% sodium thiosulfate, 0.1% protease peptone and 0.1% tryptone) and 0.2 ml of the diluted culture was subcultured on a trypticase soy agar plate for the determination of colony counts. The results, shown in Table 1, demonstrate the synergistic activity of combinations of chlorhexidine and triclosan. For example, whereas 500 micrograms per milliliter of CHA causes an approximately 17-fold decrease in CFU, and 500 micrograms per milliliter of triclosan causes an approximately 2400-fold decrease, the combination of these agents is associated with zero CFU, an at least 1×10 7 -fold decrease.
TABLE I (Anti-infective CFU/ml Agent kill) Concentration (μg/ml) (1 minute) CHA 2000 2.1 × 10 3 CHA 1000 5.0 × 10 4 CHA 500 6.0 × 10 5 TC 500 4.2 × 10 3 TC 250 2.0 × 10 5 CHA + TC 2000 + 500 0 CHA + TC 2000 + 250 0 CHA + TC 1000 + 250 0 CHA + TC 500 + 500 0 CONTROL 1.0 × 10 7
6. EXAMPLE
Combinations of Chlorhexidine and Triclosan are More Effective Than Combinations of Chlorhexidine and Silver Sulfadiazine When Applied to Hydrophilic Catheters
[0041] Polyurethane central venous catheters fabricated Of Tecoflex 93-A polyurethane were dipped in solutions containing 3 percent of a biomedical poly-urethane (Tecoflex 93-A; “PU”) and CHA, TC and/or silver sulfadiazine (“AgSD”) dissolved in 30 percent ethanol and 70 percent tetrahydrofuran (“THF”) (v/v) and air-dried. Bacterial adherence on these catheters was measured as follows. A 2 cm segment of dipped catheter was suspended in 3 ml TSB containing 10 percent BCS and incubated in a water bath shaker at 37° C. The media was changed daily. After 2 days the catheter segments were removed and transferred to fresh media containing 10 6 CFU/ml of Staphylococcus aureus and incubated for 24 hours. The segments were removed, rinsed with saline, and then suspended in LTSB drug-inactivating medium and sonicated for 20 minutes to remove the adherent bacteria. Aliquots from the LTSB extract were then subcultured on trypticase soy agar plates to determine colony counts. The results are presented in Table II, and demonstrate that combinations of CHA and TC are superior in preventing bacterial adherence when compared with CHA alone or in combination with AgSD.
TABLE II Adherent Bacteria Coating (CFU/ml) 3% PU + 2.5% CHA 5 × 10 4 3% PU + 1.5% CHA + 0.75% AgSD 2 × 10 4 3% PU + 1.5% CHA + 1% TC 5 3% PU + 1.5% CHA + 0.75% AgSD + 1% TC 40
[0042] In additional experiments, additional segments of the same type of polyurethane catheters coated with CHA, TC and/or AgSD were tested for the ability to produce zones of inhibition in trypticase soy agar plates seeded with 0.3 ml of 106 CFU of Staphylococcus aureus, Enterobacter cloacae, Candida albicans, and Pseudomonas aeruginosa. The coated catheter segments were placed vertically on the seeded plates, which were then incubated for 24 hours at 37° C. before the zones of inhibition were measured. The results, shown in Table III, demonstrate the superior effectiveness of mixtures of chlorhexidine and triclosan.
TABLE III Zone of Inhibition (mm) Coating*: Organism A B C D S. aureus 14.5 15.0 13.0 16.5 E. cloacae 9.0 12.0 7.5 3.0 C. albicans 12.0 12.0 11.5 0 P. aeruginosa 12.5 12.5 12.0 0
7. EXAMPLE
Hydrophilic Catheters Coated with Hydrophobic Polymer Comprising Chlorhexidine and Triclosan Have Antimicrobial Activity
[0043] The antimicrobial effectiveness of polyurethane central venous catheters (fabricated from Tecoflex 93-A polyurethane) coated with chlorhexidine diacetate and either triclosan or silver sulfadiazine in two polymeric coatings of differing water absorption were tested. The polymeric coatings, applied as set forth in Section 6 above, comprised either polyurethane 93A (“PU 93A”), a hydrophilic polyurethane having a water absorption of about 1-2 percent or polyurethane-silicone interpenetrating polymer (“PTUE 205”), a hydrophobic silicone-polyurethane copolymer having a water absorption of only 0.4%. Antibacterial activity was measured by zones of inhibition, using methods as set forth in Section 6, above. The results, as regards antibacterial activity toward Staphylococcus aureus, Enterobacter cloacae, and Candida albicans at days 1 and 3 of culture, are shown in Tables IV, V, and VI, respectively, and demonstrate that combinations of chlorhexidine diacetate and triclosan were effective when comprised in hydrophilic (PU 93A) as well as hydrophobic (PTUE 205) coatings.
TABLE IV Antibacterial Activity Against S. aureus Zone of Inhibition (mm) Coating Day 1 Day 3 3% PTUE 205 + 1.5% CHA + 1.5% TC 16.0 11.0 3% PTUE 205 2% CHA + 0.75% AgSD 14.5 11.0 3% PU 93A + 1.5% CHA + 1.5% TC 16.0 11.5 3% PU 93A + 2% CHA + 0.75% AgSD 14.5 11.0
[0044] [0044] TABLE V Antibacterial Activity Against E. cloacae Zone of Inhibition (mm) Coating Day 1 Day 3 3% PTUE 205 + 1.5% CHA + 1.5% TC 12.0 6.0 3% PTUE 205 2% CHA + 0.75% AgSD 8.5 0 3% PU 93A + 1.5% CHA + 1.5% TC 11.0 7.0 3% PU 93A + 2% CHA + 0.75% AgSD 7.0 0
[0045] [0045] TABLE VI Antibacterial Activity Against C. albicans Zone of Inhibition (mm) Coating Day 1 Day 3 3% PTUE 205 + 1.5% CHA + 1.5% TC 11.0 7.0 3% PTUE 205 + 2% CHA + 0.75% AgSD 12.0 9.5 3% PU 93A + 1.5% CHA + 1.5% TC 12.5 7.0 3% PU 93A + 2% CHA + 0.75% AgSD 10.0 6.5
8. EXAMPLE
Hydrophobic Catheters Treated with Hydrophobic Polymer Comprising Chlorhexidine and Triclosan Have Antimicrobial Activity
[0046] Silicone central venous catheters fabricated from Dow Corning Q7-4765A silicone polymer or Q7-4765B silicone polymer were used to determine the effectiveness of impregnation with hydrophobic polymers comprising chlorhexidine diacetate and triclosan on hydrophobic substrates. The silicone catheters were soaked for about 30 minutes in a solution of 5 percent methanol and 95 percent THF (v/v) comprising (i) 2 percent medical adhesive Silastic Type A and (ii) chlorhexidine diacetate and either triclosan or silver sulfadiazine. The dipped catheters were dried and then dipped in a solution of 5 percent methanol and 95 percent THF (v/v) containing 5 percent Silastic Type A (“SilA”), and dried again. The catheter segments were then tested for the production of zones of inhibition on trypticase soy agar plates inoculated with S. aureus or E. cloacae. The results are presented in Table VII.
TABLE VII Zone of Inhibition (mm) Treatment S. aureus E. cloacae 2% SilA + 1.5% CHA + 0.5% TC, then 5% SilA >50 21 2% SilA + 1.5% CHA + 0.5% AgSD, then 5% 17 15 SilA
9. EXAMPLE
Triclosan Exhibits Prolonged Release from Polymer Coatings
[0047] Silicone central venous catheters fabricated from Dow Corning Q7-4765A silicone polymer or Q7-4765B silicone polymer were treated as set forth in Section 8, above, and then, immediately after drying, were extracted in dichloromethane/methanol/water (50%/25%/25%, v/v) in order to determine the amount of agent contained in the catheter segment tested (i.e., the uptake). To determine the rate of drug release, catheter segments were suspended in saline and incubated at 37° C. for up to seven days; the saline was collected and replaced with fresh saline on the first day and every 48 hours thereafter, and the amount of drug present in the collected saline was measured. The results are presented in Table VIII.
TABLE VIII Uptake Release (μg/cm) Treatment (μ/cm) Day 1 Day 3 Day 5 Day 7 2% SilA + 2% CHA, 60 28.0 4.1 3.1 2.6 then 5% SilA 2% SilA + 2% TC, then 1168 10.0 9.5 11.1 11.4 5% SilA
[0048] Silicone catheters impregnated with Silastic Type A comprising either 2% triclosan or 2% chlorhexidine diacetate were then tested for the ability to produce zones of inhibition on trypticase soy agar plates inoculated with S. aureus, E. cloacae, C. albicans, or P. aeruginosa. The results of these experiments are shown in Table IX, and demonstrate that when higher concentrations of triclosan or chlorhexidine diacetate alone were used, triclosan-treated catheters were found to be equally or more effective than CHA-treated catheters.
TABLE IX Zones of Inhibition (mm) 2% SilA + 2% CHA, 2% SilA + 2% TC, Treatments: then 5% SilA then 5% SilA Organism Day 1 Day 3 Day 1 Day 3 S. aureus 17.5 16.0 >50 >50 E. cloacae 15.0 9.0 40.0 40.0 C. albicans 13.5 6.0 13.0 13.0 P. aeruginosa 13.0 0 8.5 0
10. EXAMPLE
Uptake of Chlorhexidine and Triclosan in PTFE Grafts
[0049] Arterial grafts fabricated from polytetrafluoroethylene (“PTFE”) were cut into segments and impregnated with Silastic Type A comprising chlorhexidine diacetate or triclosan in 30% methanol/70% THF (v/v), in proportions set forth below. The treated grafts were then extracted with dichloromethane/methanol/water (50%/25%/25%, v/v), and the amounts of solubilized anti-infective agents were determined. Table X shows the uptake of agent by the treated grafts.
TABLE X Treatment Agent Uptake (μg/cm) 2% SilA + 2% CHA 895 2% SilA + 2% TC 2435
11. EXAMPLE
Antimicrobial Effectiveness of Medical Articles Fabricated from Teflon, Dacron or Natural Rubber Latex and Impregnated with Combinations of Chlorhexidine and Triclosan
[0050] Chlorhexidine diacetate and either triclosan or silver sulfadiazine, in proportions set forth below, were dissolved in 5% methanol/95% THF (v/v). Segments of Dacron grafts, PTFE grafts, and natural rubber latex urinary catheters were then soaked in the resulting solutions for 15 minutes to impregnate the segments with anti-infective agents. This procedure allows the polymer substrates of the devices to incorporate anti-infective agent. The segments were then removed from the soaking solution, dried, rinsed with water, and wiped. The ability of the treated segments to produce zones of inhibition on trypticase soy agar plates inoculated with S. aureus and E. cloacae was then tested. The results, shown in Tables XI-XIII, demonstrate that the combination of chlorhexidine and triclosan produced superior antimicrobial results compared to the combination of chlorhexidine and silver sulfadiazine.
TABLE XI PTFE Graft Zone of Inhibition (mm) Impregnating Solution S. aureus E. cloacae 5% CHA + 0.5% TC 37.0 22.0 1.5 CHA + 0.75% AgSD 22.0 16.5
[0051] [0051] TABLE XII Dacron Graft Zone of Inhibition (mm) Impregnating Solution S. aureus E. cloacae 5% CHA + 0.5% TC >40 30.0 1.5 CHA + 0.75% AgSD 26.0 27.0
[0052] [0052] TABLE XIII Latex Catheter Zone of Inhibition (mm) Impregnating Solution S. aureus E. cloacae 5% CHA + 0.5% TC 26.0 20.0 1.5 CHA + 0.75% AgSD 18.0 12.0
12. EXAMPLE
Antimicrobial Effectiveness of Silicone Catheters Prepared by a One-Step Impregnation Method
[0053] Silicone catheters, as used in Example 8, were prepared by a one-step impregnation method as follows. Segments of the silicone catheters were soaked for about 30 minutes in impregnating solutions of 90% THF/10% methanol (v/v) containing 2% Silastic Type A, chlorhexidine, and either silver sulfadiazine or triclosan. The segments were then dried, and tested for their ability to produce zones of inhibition (at one and three days) in trypticase soy agar plates inoculated with S. aureus, E. cloacae, C. albicans, and P. aeruginosa. The results, presented in Table XIV, demonstrate the effectiveness of chlorhexidine and triclosan-impregnated catheters.
TABLE XIV Zones of Inhibition (mm) 2% SilA + 2% SilA + 1.5% CHA, + 1.5% CHA, + Treatments: 0.5% TC 0.5% AgSD Organism Day 1 Day 3 Day 1 Day 3 S. aureus >40 39 17.5 13.5 E. cloacae 21 21 15 8 C. albicans 13.5 7 13.5 6 P. aeruginosa 13.5 6.5 13 0
[0054] Additional formulations of impregnating solutions were tested for their ability to render the same type of silicone catheter segments anti-infective against C. albicans, the microorganism which appeared to be inhibited only by relatively high amounts of anti-infective agent. The following impregnating solutions comprised chlorhexidine, triclosan and either Silastic Type A, polycaprolactone, or no polymer in a 5% methanol/95% THF solvent. Table XV shows that when both polymer and anti-infective agent were comprised in the impregnating solution, higher anti-infective activity was achieved.
TABLE XV Impregnating Solution Zone of inhibition (mm) 4% SilA + 5% CHA + 1% TC 12.0 1% polycaprolactone + 5% CHA + 1% TC 12.0 No polymer, 5% CHA + 1% TC 6.5
13. EXAMPLE
Diffusion of Anti-Infective Agents from Medical Articles Treated with Impregnating solutions with and Without Polymer
[0055] The following impregnating solutions, “A” and “B”, were used to impregnate segments of Dacron and PTFE grafts. The treated grafts were then rinsed with saline, and the amounts of anti-infective agent incorporated into the grafts were determined, before and after rinsing, by extraction of anti-infective agent with dichloromethane/methanol/water (50%/25%/25%, v/v). The results, set forth in Table XVI, demonstrate that the addition of a polymer to the impregnating solution produces a treated medical article which exhibits greater retention of anti-infective agent.
TABLE XVI Drug Levels (μg/cm) Dacron Graft PTFE Graft Solution: A B A B Solution A Before rinsing 392 548 73 90 After rinsing 353 547 56 88 Solution B Before Rinsing 409 573 50 44 After Rinsing 132 553 24 44
14. EXAMPLE
Drug Uptake and Release by Hydrophilic Catheters Impregnated with Chlorhexidine or Triclosan
[0056] Polyurethane central venous catheter segments fabricated of Tecoflex 93-A polyurethane were impregnated with solutions “C”, “D”, “E”, “F” and “G” set forth below by soaking the catheter segments for about two minutes followed by drying and rinsing with water. Drug uptake was measured by extracting the impregnated catheter segments with dichloromethane/methanol/water (50%/25%/25% v/v). Drug release was measured over a period of six days by suspending the catheter segments in saline (one 2 cm segment in 2 ml saline), and agitated in a heated water bath at 37° C.; the saline was changed daily and drug release was measured as described above. The results are shown in Table XVII. Polyurethane, as set forth below, is Tecoflex 93-A polyurethane.
TABLE XVII Drug Release (μg/cm) Uptake Day No. Solution Drug (μg/cm) 1 2 3 4 5 6 C CHA 197 78 36 20 2.6 0.8 0.8 D TC 300 0.4 .13 0.1 0.1 0.1 0.1 E CHA 202 66 16.8 7.0 5.0 5.0 5.0 TC 230 0.4 0.3 <.1 <.1 <.1 <.1 F CHA 254 15 9.6 7.8 2.5 2.5 2.5 G CHA 223 7.1 3.5 3.0 0.8 0.8 0.8 TC 368 <.1 <.1 <.1 <.1 <.1 <.1
15. EXAMPLE
Release of Chlorhexidine and Triclosan from Impregnated Silicone Catheter Segments
[0057] Segments of silicone central venous catheters fabricated from Dow Corning Q7-4765A silicone polymer or Q7-4765B silicone polymer were impregnated with either solution H or I by soaking for 30 minutes, and then the release of drug was measured daily by methods set forth above. The results of these measurements are presented in Table XVIII.
TABLE XVIII Daily Release (μg/cm) Solution Drug Day 1 Day 2 Day 3 Day 4 Day 5 H CHA 2.7 1.0 0.6 0.9 0.9 I CHA 0.8 0.9 0.6 0.8 0.8 TC 2.6 5.6 2.3 1.5 1.5
16. Method of Rendering Polyurethane Catheters Infection-Resistant by Impregnation with a Synergistic Combination of Chlorhexidine and Triclosan
[0058] A one-step method (“Method 1”) and a two-step method (“Method 2”) were used to treat polyurethane catheters.
[0059] Method 1: An entire polyurethane central venous catheter assembly including the hub, extension line and catheter body may be soaked in an alcoholic solution containing chlorhexidine and triclosan for a specific time period sufficient to impregnate these elements with chlorhexidine and triclosan without altering the integrity of the polyurethane substrate. The following solvent systems and soaking times are suitable. The concentrations of chlorhexidine and triclosan range from 0.5-5%.
TABLE XIX Solvent system Soaking time 95% ethanol/5% water 2-30 minutes 100% reagent alcohol 2-30 minutes 90% reagent alcohol/10% water 5-60 minutes 80% reagent alcohol/20% water 5-60 minutes 70% reagent alcohol/30% water 10-60 minutes 90% ethanol/10% water 5-60 minutes 80% ethanol/20% water 5-60 minutes 70% ethanol/30% water 10-60 minutes 20% methanol/10% isopropanol/ 10-60 minutes 40% reagent alcohol/ 30% water
[0060] Selection of the solvent mixture depends on the type of polyurethane substrate and antimicrobials used for impregnation. After soaking, the catheter is rinsed in water for 24 to 48 hours to allow the catheter to regain its original integrity and size.
[0061] Method 2. A catheter impregnated with chlorhexidine and triclosan according to Method 1 is then dipped in 70% THF/30% reagent alcohol/1-3% polyurethane/1-3% chlorhexidine/1-3% triclosan.
[0062] Catheters prepared by Method 1 provide a relatively slow and steady release rate from the luminal surface and outer surface for a prolonged period of time. This pattern of drug release results from the relatively lower ratio of drug to polyurethane matrix (0.015).
[0063] Catheters prepared by Method 2 exhibit biphasic drug release. The higher ratio of drug to polyurethane in the outer coating (1.3) permits an initial release of large amounts of drugs (which may inactivate bacteria entering through the skin at the time of insertion) followed by slow and steady release of drug impregnated in the catheter by Method 1. The outer polyurethane coating acts as a barrier and permits the controlled release of drug over a prolonged period of time.
[0064] As specific examples, Tecoflex polyurethane catheters were prepared using the following method and then tested for antimicrobial efficacy in their luminal and outer surfaces:
[0065] i) catheters were soaked in 2% chlorhexidine dissolved in 100% reagent grade alcohol for 1 hour, rinsed in water, and dried for 24-48 hours (“Catheter C”);
[0066] ii) catheters were soaked in 2% chlorhexidine+2% triclosan dissolved in 100% reagent grade alcohol for 15 minutes, rinsed in water, and dried for 24-48 hours (“Catheter TC”);
[0067] iii) catheters were soaked in 2% triclosan in 70% reagent alcohol/30% water for 2 minutes, rinsed in water, and dried for 24-48 hours (“Catheter T”);
[0068] iv) catheter C (above) was dipped in 3% polyurethane+2% chlorhexidine dissolved in 70% THF/30% reagent alcohol (“Catheter C-C”);
[0069] v) catheter C (above) was dipped in 3% polyurethane+2% chlorhexidine+0.75% AgSD dissolved in 70% THF/30% reagent alcohol (“Catheter C-A”);
[0070] vi) catheter T (above) was dipped in 2% chlorhexidine+2% triclosan dissolved in 70% THF/30% reagent alcohol (“Catheter T-R”);
[0071] vii) catheter TC (above) was dipped in 2% chlorhexidine+2% triclosan dissolved in 70% THF/30% reagent alcohol (“Catheter TC-R”); and
[0072] viii) catheter TC (above) was dipped in 2% chlorhexidine+0.75% AgSD dissolved in 70% THF/30% reagent alcohol.
[0073] Trypticase soy agar plates were seeded with 10 CFU Staphylococcus aureus/ml and 0.5 cm segments of catheter were embedded vertically. The plates were then incubated for 24 hours at 37° C. and zones of inhibition were measured. The results are shown in Table XX.
TABLE XX Catheter type (mm) Zone of Inhibition Surface Lumen Outer C 15 15 T 21 21 TC 25 25 C-C 15 18 C-A 15 18 T-R 21 25 TC-R 23 26 TC-A 23 26
17. Method of Rendering Polyurethane Catheters Infection-Resistant by Impregnation with a Synergistic Combination of Chlorhexidine Free Base and Triclosan
[0074] It was further discovered that when catheters were coated using insoluble chlorhexidine free base and triclosan, a soluble chlorhexidine/triclosan complex was formed which improved the drug uptake and, therefore, the efficacy of the catheter.
[0075] Method 3: Catheters prepared by Method 1 (see Section 16) were dried for 24-72 hours and then their outer surfaces were dipped in a polyurethane solution (1-3% polyurethane dissolved in THF/alcohol). Catheters prepared by this method exhibited a large amount of drug release initially followed by a small but synergistically effective amount of drug release for a prolonged period of time.
[0076] Method 4: Followed the same procedure as Method 1, except that insoluble chlorhexidine free base (CHX) was solubilized with triclosan (1 molar CHX:2 molar triclosan ratio), which forms a complex with CHX. After soaking for 5-10 minutes the catheters were dried for 1-3 days and then the outer surface was dipped in either a polyurethane solution alone (1-3% polyurethane) or a solution of polyurethane containing CHX and triclosan (TC).
[0077] When relatively soluble chlorhexidine salts such as chlorhexidine acetate (CHA) were used to impregnate catheters, the release was undesirably rapid. We investigated the use of CHX as a substitute for CHA. CHX is not soluble is water or alcohol but, surprisingly, we found that when it was combined in a 1:2 molar ratio with triclosan, an alcohol soluble complex formed.
[0078] The uptake of chlorhexidine from a solution containing CHX-TC complex was greater than that obtained from a CHA-TC solution despite a higher CHA concentration in the soaking solution. Due to higher chlorhexidine levels and higher rate of chlorhexidine release from the substrate resulting from impregnation with CHX-TC complex, the infection resistance of the catheters was greater than those containing only CHA.
[0079] Method 5: Same as method 4 but the soaking and outer coating solutions also contained soluble chlorhexidine acetate.
[0080] As specific examples, the following experiments were performed using Tecoflex catheters:
[0081] (1) Catheters were prepared according to Method 3. Specifically, catheters were soaked in 5% CHA+1% TC dissolved in reagent alcohol for 10 minutes, dried for three days, and then the outer surface was dipped in 2.7% Tecoflex polyurethane dissolved in THF/reagent alcohol (70%/30%); the resulting catheters are referred to as type 1, and the polyurethane/THF/reagent alcohol solution is referred to as Solution J.
[0082] (2) A second group of catheters was prepared as in (1), but instead of using Solution J for the outer coating, another solution was used: 0.5% CHX+0.5% TC+2.7% polyurethane dissolved in 70% THF/30% reagent alcohol (“Solution K”). The resulting catheters are referred to as type 2.
[0083] (3) Catheters were prepared using Method 5. Specifically, catheters were soaked in a solution containing 2% CHX+2% CHA+2% TC dissolved in reagent alcohol for 10 minutes, dried for 3 days and their outer surfaces were dipped in Solution J. The resulting catheters are referred to as type 3.
[0084] (4) Catheters were prepared as in (3) but were dipped in Solution K to produce an outer coating. The resulting catheters are referred to as type 4.
[0085] (5) Catheters were prepared according to Method 4. Specifically, catheters were soaked for 10 minutes in 3% CHX+3% TC in reagent alcohol, dried for 3 days, and outer surface coated in Solution J. The, resulting catheters are referred to as type 5.
[0086] (6) Catheters were prepared as in (5) but outer surface coated with Solution K. The resulting catheters are referred to as type 6.
[0087] (7) Catheters were prepared according to Method 3. Specifically, catheters were soaked in a solution containing 5% CHA+1% TC in reagent alcohol for 10 minutes, dried for 3 days and then outer surface coated using Solution J. The resulting catheters are referred to as type 7.
[0088] (8) Catheters were prepared as in (7), except were outer surface coated with 2.7% polyurethane+3% CHA in 70% THF/30% reagent alcohol. The resulting catheters are referred to as type 8.
[0089] Segments of catheter types 1-8 were placed vertically in inoculated trypticase soy agar plates inoculated with 108 CFU of Staphylococcus aureus per plate, and incubated for 24 hours. After measuring the zones of inhibition, the catheters were transferred daily to fresh culture plates (shown in Table XXI).
TABLE XXI Catheter type (mm) Day Zone of Inhibition 1 21 12.0 2 21 13.0 3 21 17.0 4 21 20.0 5 21 20.0 6 21 23.0 7 21 5.0 8 21 9.0
[0090] The amount of drug uptake per cm/catheter in catheters prepared using various soaking solutions was measured as set forth above.
TABLE XXII Drug Uptake/cm catheter Soaking Solution Chlorhexidine Triclosan 5% CHA 260-310 — 5% CHA + 2% TC 280-300 450-480 2% CHX + 2% TC + 2% CHA 480-520 300-370 3% CHX + 3% TC 550-660 600-700
[0091] The luminal adherence of bacteria was quantified in catheters impregnated with antimicrobials and then coated with a solution of 2.7 percent Tecoflex 93A and various antimicrobial agents. Bacterial adherence was measured as follows. 12 cm segments of test and control 7Fr catheters were each connected to an individual channel of a peristaltic pump via an extension line, hub, and injection cap. The hubs were inoculated initially and after 24 hours with 10 6 cfu of S. aureus which causes the extension line to become colonized thus acting as a continuous source of bacteria for seeding lumens. The lumens were continuously perfused at a rate of 20 ml/hour with trypticase soy broth (TSB) diluted 1:10 with physiological saline over the course of 7 days. At the end of one week the catheter segments were disconnected and their outer surfaces disinfected with 70% ethanol. Each lumen was flushed with sterile TSB to remove non-adherent bacteria. Each catheter was then cut into 2 cm segments each of which is further divided into 2 mm subsegments and placed in tubes containing 4 ml of antiseptic inactivating broth (LTSB). The tubes were sonicated for 20 minutes at 4° C. to remove bacteria adhering to the lumens. To quantify the adherence, a 0.5 ml aliquot of the LTSB extract was subcultured on trypticase soy agar plates. The results are shown in Table XXIII.
TABLE XXIII DRUG IN BACTERIAL SOAKING SOLUTION DRUG IN ADHERENCE (cfu/cm) OUTER COATING IN LUMEN 5% CHA 3% CHA 3 × 10 4 5% CHA + 0.5% TC 2% CHA + 2% TC 3 × 10 2 2% CHX + 2% CHA + 2% CHA + 2% TC 0 2% TC 3% CHX + 3% TC 0.5% CHX + 0.5% TC 0 0 (control) 0 4 × 10 6 2% CHX + 2% CHA + no outer coating 5 2% TC
[0092] Various publications are cited herein, which are hereby incorporated by reference in their entireties.
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The present invention relates to polymeric medical articles comprising the anti-infective agents chlorhexidine and triclosan. It is based, at least in part, on the discovery that the synergistic relationship between these compounds permits the use of relatively low levels of both agents, and on the discovery that effective antimicrobial activity may be achieved when these compounds are comprised in either hydrophilic or hydrophobic polymers. It is also based on the discovery that chlorhexidine free base and triclosan, used together, are incorporated into polymeric medical articles more efficiently. Medical articles prepared according to the invention offer the advantage of preventing or inhibiting infection while avoiding undesirably high release of anti-infective agent, for example into the bloodstream of a subject.
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CROSS REFERENCE TO RELATED APPLICATION
This is a divisional of application Ser. No. 08/172,158 filed Dec. 23, 1995, now U.S. Pat. No. 5,479,679.
This application claims the priority of German Application Nos. P 42 43 833.0 filed Dec. 23, 1992 and P 43 34 035.0 filed Oct. 6, 1993.
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for feeding a fiber tuft mass (fiber batt), composed of, for example, cotton fibers, synthetic fibers or the like, to a fiber processing machine, such as a carding machine or a cleaner to prepare the fiber for spinning. The apparatus has a fiber advancing mechanism formed of a feed roll and a cooperating feed table followed by at least one opening device such as an opening roll. The fiber advancing mechanism also serves as a batt thickness sensor. For this purpose the feed table is formed of a plurality of individually movable feed table segments which undergo excursions as the throughgoing fiber batt changes in thickness. Each movable feed table segment is biased towards the feed roll by a spring arrangement and is connected, with the intermediary of the respective springs, with a rotatably supported biased common holding element which senses the sum of the displacements of the individual feed table segments.
In a known apparatus of the above-outlined type, generally referred to as pedal-type or piano key-type regulating device, a fiber batt feeding aggregate and a rapidly rotating opening roll are arranged in series. The batt feeding aggregate is formed of a feed roll with feed table and upstream thereof (as viewed in the direction of fiber feed) there is arranged a sensor device having a fiber batt advancing roll cooperating with a plurality of sensor fingers. Thus, the sensing and feeding of the fiber material to the opening roll are spatially separated. By means of the sensor fingers the sensor device mechanically detects thickness variations of the fiber batt at several locations along the width of the fiber batt. Each sensor finger is an angled, two-arm lever rotatably held in its mid portion. The free end zone of one lever arm forms the sensor member proper, while at the free end zone of the other lever arm a tension spring is attached. In this manner each sensor finger is movably mounted for displacement in response to thickness variations in the fiber batt and each sensor finger is individually biased by its tension spring in such a manner that the sensor fingers press the fiber material against the feed roll. All tension springs are attached with one of their ends to one lever arm of a rotatably supported common two-arm summing lever. The other arm of the summing lever is attached to a weight, whereby to each sensor finger a fiber material pressing force is imparted with the intermediary of the tension springs and the summing lever. With the other lever arm of the summing lever an inductive proximity switch is associated which transforms excursions into electric pulses. A delayed, path-dependent shift register ensures that the corresponding regulating pulse affects the rotary speed of the downstream connected feed roll of the feed roll/feed table assembly (feeding assembly) for the opening roll only when the respective sensed areas of the fiber batt arrive in the working zone of the fiber feeding assembly.
It is a disadvantage of the above-outlined prior art construction that it is structurally complex and it is complicated to assemble. A great number of individual structural elements are required, for example, a separate rotary bearing has to be provided in order to support individually each sensor finger. Such rotary bearings are complex, expensive and they must be aligned with high precision. It is a further disadvantage of the prior art arrangement that the sensor fingers are separately connected with the common summing lever. Thus, the tension springs are needed as separate force-transmitting elements between the lever arms of the sensor fingers and the spaced lever arm of the summing lever. The individual tension springs are attached (hooked) at their ends with a certain clearance and their elongation may lead to tolerances and deviations which jeopardizes accurate measurements during operation. Particularly the determination of the sum of the thickness deviations is imprecise because the excursion of each individual sensor finger is measured indirectly. Because of the possibility of deviations in the tension springs, a uniform clamping of the fiber material along its width is adversely affected as well.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved apparatus of the above-outlined type from which the earlier discussed disadvantages are eliminated, which is particularly structurally simple and makes possible an improved measurement and clamping of the fiber batt.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the apparatus for feeding a fiber batt to a fiber processing machine includes a feed roll; a feed table formed of a plurality of separately movable feed table segments each cooperating with the feed roll and defining therewith a nip through which the fiber batt passes; a plurality of springs each being affixed to the feed table segment to form integral components therewith; and an elongated holding element extending spaced from, and generally parallel to the feed roll. Each spring is affixed to the holding element. The feed table segments are individually movable away from the feed roll against a force of respective springs in response to thickness variations in the fiber batt as the fiber batt passes through the nip. There is further provided a support for rotatably supporting the holding element. The feed table segments impart torques on the holding element through the respective springs as a function of movements of the feed table segments and the holding element is rotated by the torques to an extent representing a sum of the torques. A sensor is connected to the holding element for generating a signal as a function of rotary displacements of the holding element.
The invention provides an apparatus which is structurally simple and is uncomplicated to install and further makes possible an improved measurement (thickness sensing) and clamping of the fiber material. By the plurality of feed table segments an individual (zonewise separated) measuring and clamping of the fiber material along the entire width of the fiber batt is possible. Further, the mechanical summing is structurally simple; only a single sensor is required. It is a particular advantage of the invention that each feed table segment and the associated spring constitute an integral structural component. The spring has several functions: it firmly holds the feed table segment (securement of the segment), it holds the segment in position relative to the feed roll, and, being itself secured to the holding element, it also secures the segment to the holding element. Furthermore, as the segment undergoes an excursion in response to a thickness variation of the throughgoing fiber batt, it imparts a torque to the holding element, that is, it transfers the excursion of the segment directly to the holding element as a rotary motion. By virtue of the measures according to the invention, particularly by virtue of the integral construction of each segment and its spring on the one hand and the springs and the holding element, on the other hand, all excursions of the feed trays are transferred through a short path to the holding element simply, directly and immediately to thus sense the sum of the displacements. The apparatus is simple, because individual rotary bearings for the individual feed table segments are no longer needed. Furthermore, the apparatus is easy to install since there is no need to secure each individual segment via a spring but the entire apparatus may be installed as a single structural component.
The invention has the following additional advantageous features:
The spring is a leaf spring and with each feed table segment there is associated at least one leaf spring and is connected therewith by screws, rivets or an adhesive. By using leaf springs, the connection is particularly simple and permanent since relatively large surfaces are available for securement.
With each feed table segment there are connected two leaf springs which, as viewed in the direction of fiber feed, are attached at the upstream and downstream ends of the segments.
Each leaf spring is, at one end, firmly secured to the feed table segment and is, at the other end, firmly secured to the holding element.
The leaf springs for each feed table segment are spaced from one another in the direction of fiber feed.
The leaf springs are arranged parallel to one another.
The leaf springs are relatively stiff in the direction viewed parallel to the distance between feed table segment and holding element and are relatively soft in the direction viewed perpendicularly to a plane defined by such distance and the axis of the feed roll.
The holding element is a longitudinal beam oriented axially parallel to the feed roll.
The holding element is torsion resistant.
An axially extending torsion bar is attached to an end of the holding element. The torsion bar is biased by a spring or is itself a torsion spring.
The torsion bar is supported with a soft resilient force.
The torsion bar is supported in a stationary bearing.
The bias of the torsion bar is adjustable.
The holding element is, at one end, supported in a rotary bearing.
The torsion bar is associated with a measuring element for measuring the extent of the rotary displacement of the holding element.
The measuring element is an inductive path sensor.
The measuring element includes expansion measuring strips.
The feed table segments arranged along the length of the feed roll mechanically detect thickness variations of the fiber batt at various locations along the fiber batt width and the variations are, by means of the common holding element, combined into an average value of thickness variations.
Dependent upon the deviation Of an actual average value from a desired value, the fiber quantities (supply rate) to the fiber processing machine are varied.
The fiber feeding apparatus is, as a measuring and clamping device, arranged directly upstream of the opening roll. In this manner the feed table fulfills not only its usual role as a clamping device but has a dual function because it simultaneously serves as a measuring member so that additional devices for measuring the thickness fluctuations in the inlet zone of the fiber processing machine may be omitted.
The feed table segments are arranged above the feed roll.
The leaf springs project in the securing zone of the feed table segments into the nip between the slowly rotating feed roll and the rapidly rotating opening roll.
With the feed table segments there is associated a fixed abutment element which has a dual function: it prevents the feed table segments from contacting the feed roll and provides for a bias for the leaf springs.
The feed roll support is fixed.
The distance between the surfaces of the feed table segments and the circumferential surface of the feed roll decreases along the roll circumference viewed in the working direction.
The distance between the feed table segments on the one hand and the circumferential surface of the feed roll on the other hand is the smallest at the clamping location (nip).
The feed table segments are hollow extruded components. The cavity of the segments is coupled to a vacuum or air pressure source.
In the clearance between two adjoining feed table segments a seal is arranged.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic side elevational view of a carding machine incorporating the invention.
FIG. 2 is a perspective view of a preferred embodiment of the invention.
FIGS. 3 and 4 are schematic sectional side elevational views of two further preferred embodiments of the invention.
FIGS. 5, 6 and 7 are schematic perspective views of three further preferred embodiments of the invention.
FIGS. 8 and 9 are sectional side elevational views of two further preferred embodiments of the invention.
FIG. 10 is a schematic side elevational view of a further preferred embodiment of the invention illustrating the feed table segments underneath the feed roll.
FIG. 11 is a sectional side elevational view of a pneumatic fiber tuft feeder incorporating the invention.
FIG. 12 is a sectional side elevational view of a further preferred embodiment of the invention.
FIGS. 13, 14, 15a, 15b, 16, 17, 18a, 18b, 19a, 19b and 19d are schematic perspective views of eleven further preferred embodiments of the invention.
FIG. 19c is a schematic side elevational view of yet another preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, there is illustrated therein a carding machine which may be, for example, an EXACTACARD DK 760 model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany. The carding machine has a feed roll 1, a feed table 2, a licker-in 3, a main carding cylinder 4, a doffer 5, a stripping roll 6, crushing rolls 7 and 8, a web guiding element 9, a sliver trumpet 10, calender rolls 11 and 12 as well as travelling flats 13.
Turning to FIG. 2, above the feed roll 1 there are serially arranged feed table segments 2a, each being connected with a holding element 15--functioning as a summing beam--by means of an associated front leaf spring 14a and a rear leaf spring 14b. Each leaf spring has first and second zones of securement, such as 14a' and 14a" shown for the right-most spring 14a in FIG. 2. Each leaf spring is attached to a respective feed table segment 2a in the first zone of securement and to the holding element 15 in the second zone of securement. Each leaf spring is relatively hard in the direction Q which extends from the first to the second zone of securement and which is perpendicular to the rotary axis 1' of the feed roll 1, whereas each leaf spring is relatively soft in the direction R which is perpendicular to the direction Q and to the rotary axis 1' of the feed roll 1. The holding element 15, whose length dimension is oriented parallel to the rotary axis 1' of the feed roll 1, is provided at one end with a torsion bar 18 fixedly held in a stationary support 16. From the opposite end of the holding element 15 a shaft 35 extends which is movably supported in a bearing 17. Between the feed table segments 2a and the feed roll 1 a fiber batt 19 passes which, in the zone of the clamping location (nip) between feed roll and feed table segment has a thickened part 20, causing the feed table segment 2a to execute an excursion in the direction of the arrow G. By virtue of such an excursion the leaf springs 14a and 14b are moved in the directions of arrows F, F'. Such an excursion leads to a rotary motion of the holding element 15 in the counterclockwise direction as indicated by the arrow D, causing a torsional deformation of the torsion bar 18 in the direction of the arrow A, whereby the expansion measuring strips 23 are deformed and such a deformation may be represented by a signal. After regulation, the torsion effect is cancelled, that is, the torsion bar 18 and the holding element 15 rotate back in the direction of arrows B and C, respectively, the leaf springs 14a, 14b swing back in the direction of the arrows E, E' and the feed table segment 2a moves in the direction H into its initial position
In the embodiment illustrated in FIG. 3, the holding element, that is, the summing (adding) beam 15 clampingly holds the springs 14 (only one visible). Each feed table segment 2a (only one visible) has at one end a foot 2a' affixed to the lower end of the respective spring 14.
The embodiment according to FIG. 4 includes a channel 34 which extends from a non-illustrated card feeder and which opens in the fiber grasping zone formed of the feed roll 1 and the feed table segments 2a. The channel 34 has an apertured portion 33 shrouded by suction hoods 32. Similarly to FIG. 3, the feed table segments 2a have a foot 2a' and are connected by respective leaf springs 14 with the holding element 15. In the fiber intake zone a sealing flap 31 extends which at its upper end is secured to the holding element 15.
In the embodiment illustrated in FIG. 5 the fiber batt 19 is advanced on a transfer tray 39 to the feed roll 1 above which the feed table segments 2a are supported by respective springs 14 which extend generally horizontally and are secured to the holding element 15. Underneath the springs 14 a rectangular abutment bar 37 extends parallel to the feed roll 1. The abutment bar 37 prevents the feed bar segments 2a from contacting the feed roll 1. The rear terminus of each leaf spring 14 is secured to the holding element 15 which is rotatably supported by bilaterally extending shafts 35a, 35b which, in turn, are rotatably held in bearing blocks 17a, 17b. At their extensions beyond the bearing blocks 17a, 17b the shafts 35a, 35b carry respective levers 28a, 28b which are biased in the direction of fiber feed by means of respective compression springs 21a, 21b. To each lever 28a, 28b there is connected a plunger armature of respective inductive path sensors 22a, 22b which emit a signal representing the extent of the displacement of the plunger armature.
The embodiment illustrated in FIG. 6 is similar to that shown in FIG. 5 except that instead of shafts 35a, 35b shown in FIG. 5, the holding element 15 is, at each end, provided with torsion bars 18a, 18b which are held in fixed supports 16a, 16b, respectively. The torsion bars 18a, 18b carry expansion measuring strips 23 by means of which the motion, that is, the rotation of the holding element 15 is detected.
In the embodiment illustrated in FIG. 7 the construction which is similar to that of FIG. 5, also has a regulatable biasing device 27 which includes a stationary nut 25 affixed to the machine frame, a threaded spindle 29 threadedly engaging and passing through the nut 25, a pressure plate 26 carried at one end of the spindle 29 and a handwheel 24 attached to the opposite end of the spindle 29. The pressure plate 26 is connected with the loading arm 28 of the shaft 35 by means of a compression spring 30. The desired bias on the holding element 15 is thus adjustable by turning the handwheel 24. It will be understood that instead of the handwheel 24 a motorized adjusting mechanism may be used.
In the embodiment illustrated in FIG. 8 the frontal and rear leaf springs 14a and 14b are of different length and the frontal leaf springs 14a are so designed that they extend into the nip between the feed roll 1 and the licker-in (opening roll) 3. The leaf springs 14a and 14b are attached by screws 38 at their lower ends to the feed table segments 2a and at their upper ends to the holding element 15. The abutment bar 37 is mounted adjacent a projection 42 provided on a rear portion of each feed table segment 2a, and the clearance between the abutment bar 37 and each projection 42 is so designed that even in case of a bias the feed table segments 2a cannot contact the feed roll 1. To ensure that the leaf springs 14a, 14b do not enter into contact with the walls of the holding element 15 and the feed table segments 2a to thus allow an unimpeded motion of the feed table segments, the feed table segments 2a and the holding element 15 are provided with recesses 36 in the zone of the leaf springs 14a, 14b. On the underface of the holding element 15 a support bar 40a is carried whereas on the top face of each feed table segment 2a a support post 40b is arranged. Between each post 40b and the support bar 40a a spiral spring 41 is arranged which, in addition to the leaf springs 14a and 14b resiliently suspends the respective feed table segment 2a from the holding element 15.
In the embodiment illustrated in FIG. 9 the leaf springs 14a and 14b attaching each feed table segment 2a to the holding element 15 are inclined rather than in a perpendicular arrangement with respect to the segments 2a and the holding element 15 as it was the case in the earlier described embodiments. Further, the holding element 15 has along its entire length, that is, in a direction transversely to the advancing direction of the fiber material, an abutment bar 37b affixed to an underside thereof with which cooperate respective abutment posts 37a mounted on the top face of each feed table segment 2a. The distance between the abutment bar 37b on the one hand and the abutment posts 37a on the other hand is less than the width of the smallest clearance between the feed roll 1 and the feed table segments 2a to thus securely prevent any feed table segment 2a from contacting the feed roll 1.
In the embodiment illustrated in FIG. 10 the feed table segments 2a (only one visible) are arranged underneath the feed roll 1. Here too, the individual feed table segments 2a are connected with the holding element 15 by means of leaf springs 14a, 14b. The holding element 15 is at both ends connected with a torsion bar 18. A regulating device (microcomputer) 50 is provided, an input of which receives signals which represent the displacements of the torsion bar 18 and an output connected to the drive motor 52 of the feed roll 1 to regulate the speed of the feed roll 1 as a function of the thickness variations of the fiber batt 19 as it passes between the feed roll 1 and the feed table segments 2a.
Turning to FIG. 11, there is illustrated a fiber tuft feeder which supplies a carding machine with the fiber batt 19. The fiber tuft feeder may be an EXACTAFEED FBK 533 model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany. The fiber material is pneumatically delivered in a fiber tuft conveying duct to the upper, reserve chute 43 and the material is driven downwardly by the air pressure onto a feed roll 44. The feed roll 44 cooperates with feed table segments 45 (only one segment is visible in FIG. 11), each being connected to a holding element 15 by separate leaf springs 14a, 14b. Upon thickness variations of the material passing between the feed table segments 45 and the feed roll 44 the respective feed table segment 45 is pushed away from the feed roll 44. Upon such occurrence, the leaf springs 14a, 14b bend and tend to rotate the holding element 15 in a clockwise direction as viewed in FIG. 11. The evaluation of the turning motion of the holding element is effected in a manner similar to the earlier-described embodiments. From the feed roll 44 the fiber batt 19 is admitted by means of an opening roll 47 into the feed chute 46 from which it is advanced onto the transfer plate 39 by a pair of cooperating withdrawing rolls.
In the embodiment illustrated in FIG. 12 the holding element 15 is a hollow extruded member, made for example of aluminum, having hollow spaces 15c and 15d. The oscillation behavior of the feed table segments 2a is an important consideration. If the segments 2a were imparted a frequency close to their natural frequency, they would start oscillating with a natural frequency which would present an uncontrolled movement which would endanger their function. Consequently, the natural frequency of the segments should be as high as possible. Since the natural frequency is primarily dependent from the own flexure, the weight must be held small. For this reason aluminum is selected for the holding element 15. The selection of a light-weight material for the holding element 15 is further advantageous because the reduced weight facilitates the installing operation. Also, the selection of aluminum allows production of the shape of the beam 15 by means of an extrusion process. This eliminates the need for mechanical shaping. Between the holding element 15 and the feed table segments 2a an abutment bar 37 is arranged.
An abutment bar 37 is provided between the holding element 15 and the feed table segments 2a. The abutment bar 37 extends in a space defined by outer top grooves provided in the feed table segments 2a. A cooperation between a side wall of the top grooves and the abutment bar 37 limits the excursion path for each feed table segment 2a. In the holding element 15 throughgoing grooves 55a, 55b are provided which have a T-shaped cross section and each accommodates a respective fastening rail 56a, 56b for fastening the leaf springs 14a, 14b by means of screws 57a, 57b.
In the embodiment shown in FIG. 13 the lower ends of the leaf springs 14a project downwardly beyond the lower end of the feed table segments 2a by a distance a. The leaf springs 14a which are made of hardened steel form in the zone of the narrow transition gap wear-resistant elements exerting a high pressing force. In this zone the leaf springs 14a are in direct contact with the fiber material.
The embodiment according to FIG. 14 has a one-piece feed table 2. The holding element 15 (summing beam) is also a throughgoing, one-piece element and is rotatably held with respect to the stationary machine frame for performing measurements. An abutment and securing strip 58 is provided, whose part 58b clamps a series of leaf springs 14a against the holding element 15, for example, by means of screw connections. The part 58a of the securing strip 58 is at a clearance b to the leaf springs 14a so that this zone 58a provides an abutment for the leaf springs 14a to limit their excursions away from the feed roll 1. The leaf springs 14a also serve as clamping springs for the fiber material. The free ends of the leaf springs 14a may swing away from the frontal face 2' of the feed table 2.
In the construction shown in FIG. 15a the one-piece feed table 2 is resiliently held relative to the machine frame. For this purpose a spring 59 is provided so that a deviation in case of thickness variations of the fiber batt and the generation of a signal for monitoring the material thickness and the regulation of the material supply is possible.
According to the embodiment illustrated in FIG. 15b the feed table 2 is stationarily held while the feed roll 1 is resiliently supported with the aid of a spring 60. With the feed table 2 leaf springs 14a are associated.
In the embodiment shown in FIG. 16 the feed table 2 is, with the aid of springs 61a, 61b, supported resiliently relative to the holding element 15.
In FIG. 17 which shows a structure similar to FIG. 16, the feed table 2 is at one end pivotally secured to the machine frame with the aid of a pivot bearing 62.
In the embodiment illustrated in FIG. 18a the feed table 2 is supported in a guide 63 allowing the feed table to execute horizontal displacements as indicated by the arrows I, K. This arrangement prevents a vertical motion component of the feed table and thus the inductive path sensor 22 senses only the horizontal displacements of the feed table 2. At one end of the feed table 2 a tension spring 64 is provided to urge the feed table in the direction of the arrow I and to thus provide a pressing force on the fiber material in cooperation with the feed roll 1. FIG. 18b illustrates the excursions of the leaf springs 14 of the FIG. 18a embodiment towards and away from the surface 2' of the feed table 2, as indicated by the arrows L and M.
FIGS. 19a-19d show various embodiments concerning the location of rotary support for the feed table 2. According to FIG. 19a, the feed table is supported at one end by means of springs 66. A pivot pin 65 is provided in the zone of the leaf springs 14a at the frontal end of the feed table 2 to be received in a bearing socket (not shown). In the structure according to FIG. 19b, the feed table 2 is supported by springs 67 in the zone of the leaf springs 14a at the frontal end and at the rear terminus the feed table 2 is rotatably supported by a pivot pin 66. FIG. 19c shows an embodiment similar to FIG. 19a in which, however, the pivotal support 68 is situated above the feed table 2. In FIG. 19d the construction is similar to that of FIG. 19b in which, however, the pivotal support 69 is situated in approximately the lateral middle of the feed table 2.
In the embodiments of FIGS. 18a, 19a-19d the excursion of the leaf springs 14a imparts a force on the feed table 2 which functions as a summing beam and whose linear shift (FIG. 18a) or rotation (FIGS. 19a-19d) is measured. It is noted that the springs 59, 60, 61a, 61b, 64, 66 and 67 are harder than the leaf springs 14a which form the sensor elements.
Advantageously, the apparatus may also be used as laboratory instrument for determining the cleanability of cotton.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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An apparatus for feeding a fiber batt to a fiber processing machine includes a feed roll; a feed table formed of a plurality of separately movable feed table segments each cooperating with the feed roll and defining therewith a nip through which the fiber batt passes; a plurality of springs each being affixed to the feed table segment to form integral components therewith; and an elongated holding element extending spaced from, and generally parallel to the feed roll. Each spring is affixed to the holding element. The feed table segments are individually movable away from the feed roll against a force of respective springs in response to thickness variations in the fiber batt as the fiber batt passes through the nip. There is further provided a support for rotatably supporting the holding element. The feed table segments impart torques on the holding element through the respective springs as a function of movements of the feed table segments and the holding element is rotated by the torques to an extent representing a sum of the torques. A sensor is connected to the holding element for generating a signal as a function of rotary displacements of the holding element.
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FIELD OF THE INVENTION
The present invention relates to a reciprocating engine and to a working fluid inlet system for a reciprocating engine, such as a steam inlet system for a heat engine such as a Rankine cycle engine, the reciprocating engine being of the type that does not rely upon an internal chemical reaction (such as an internal combustion engine) for the reciprocating movement.
BACKGROUND OF THE INVENTION
One of the earliest forms of engine developed for providing mechanical work was a Rankine cycle engine, often referred to as a ‘steam engine’ because the majority of such engines used steam as their working fluid (and were thus considered to be steam driven). Steam engines were reciprocating engines that typically had a reciprocating piston in a cylinder, with an inlet valve and an exhaust valve (usually at the same end of the cylinder), the piston being connected by a rod and a crank to a flywheel or the like.
During operation of the engine, with the piston at ‘top dead centre’ (referred to as ‘TDC’), the inlet valve was opened, allowing steam to enter from a boiler. The expanding steam drove the piston in its expansion (or power) stroke, whereupon the inlet valve would close, allowing the steam in the cylinder to expand to a lower pressure. As the piston reached ‘bottom dead centre’ (referred to as ‘BDC’), the exhaust valve would open allowing the steam, which was generally still at significant pressure, to escape as the piston travelled back up the cylinder to TDC on its return stroke.
In such an operation, it is ideal to open and close the inlet valve infinitely quickly, and to close the inlet valve early in the power stroke, providing a high expansion ratio. However, in the early 1900's valve actuation technology was limited and poor efficiencies were thus accepted throughout the development of such engines. Indeed, the inability to close the inlet valve early enough was a major factor leading to the development of compound engines (double, triple and even quadruple expansion engines) where steam would be routed to a second, larger capacity cylinder where it was similarly expanded. Sometimes there was also a third, or even a fourth stage where this would be repeated.
While engines of this type generally performed satisfactorily, subsequent developments in engine design produced engines of greater efficiency and higher horsepower to weight ratios, such as the internal combustion engine, the steam turbine and the like. As a result, the use of steam engines fell away, so much so that steam engines became quite rare.
However, with increasing emphasis on environmental and pollution considerations, and with the continuing rise in the price of fossil fuels, there has recently been renewed interest in steam engines, particularly for use in small cogeneration or combined heat and power (CHP) systems.
Accordingly, there is a renewed need for improvements to, in particular, the inlet valve systems for such steam engines and, in general, to the working fluid inlet systems for reciprocating engines of any type where a high pressure gas or vapour is fed to a cylinder in a controlled manner.
SUMMARY OF THE INVENTION
The present invention provides a working fluid inlet system for a reciprocating engine, the engine including at least one cylinder with a reciprocating piston therein and having a variable volume expansion chamber capable of receiving a working fluid via an inlet valve, the inlet system including:
a pilot valve having an open condition where secondary fluid passes therethrough to act on the inlet valve, and a closed condition; and actuating means for controlling the condition of the pilot valve; wherein the inlet valve is adapted to open in response to the action of the secondary fluid.
The present invention also provides a reciprocating engine utilizing the working fluid inlet system described above, together with a method of operating such a reciprocating engine. In this respect, the engine may have one or more reciprocating piston/cylinder arrangements, there being at least one of the inlet systems of the present invention associated therewith.
Indeed, the present invention also provides a reciprocating engine including at least one cylinder with a reciprocating piston therein and having a variable volume expansion chamber capable of receiving a working fluid via an inlet valve, the engine including a working fluid inlet system and exhaust means, the working fluid inlet system including a pilot valve having an open condition where secondary fluid passes therethrough to act on the inlet valve, and a closed condition, and actuating means for controlling the condition of the pilot valve, wherein the inlet valve is adapted to open in response to the action of the secondary fluid, the exhaust means including at least one exhaust valve in the piston and at least one exhaust port in the piston, the exhaust valve being configured to open automatically when the pressure above the piston drops to a threshold pressure above an exhaust port pressure.
Ideally, as will be explained below, the reciprocating engine will be a Rankine cycle engine that uses steam as the working fluid, and that has only a single reciprocating piston/cylinder arrangement that preferably operates on the uniflow principle. However, it will be appreciated that the reciprocating engine need not necessarily contain a ‘piston’ and a ‘cylinder’ in the traditional sense, but rather simply needs to have an expansion volume and a positive displacement expander.
For example, a system of this type that may contain other than a piston/cylinder arrangement is a Wankel rotary expansion chamber comprising a triangular rotor which rotates on an eccentric shaft and is within, and geared to, an epitrochoidal housing. Thus, the continued reference throughout this specification to a piston/cylinder arrangement should be interpreted to cover at least this type of arrangement.
Also, in the preferred configuration the working fluid and the secondary fluid will be sourced from the same supply. Indeed, it is envisaged that, in most situations, the working fluid will be steam from a boiler, and the secondary fluid will also be steam, supplied by the same boiler (although the engine may be powered by solar energy or some other low grade heat source, and may use any organic working fluid). Thus, the reference to ‘secondary fluid’ throughout the specification should not be seen as requiring the secondary fluid to be of a different type (or from a different source) to the working fluid.
It will be appreciated that the inlet system of the present invention provides for rapid opening and closing of the inlet valve, and for the timing of at least the closing of the inlet valve to be controllable so as to be early in the expansion (power) stroke of the engine. Such ease of variable valve timing avoids the need to maintain constant inlet valve admission and cut-off timing, which in many traditional steam engines required throttling of the steam to run at part power, introducing obvious inefficiencies.
Additionally, the present invention permits the inlet valve to be actuated indirectly (by the pilot valve) rather than directly, which avoids the need for an electrical or mechanical actuating means capable of generating large forces at high speeds.
GENERAL DESCRIPTION OF THE INVENTION
The secondary fluid for use with the pilot valve may be any suitable fluid, pressurized in any suitable manner, and may for instance be any suitable pressurized liquid or gas/vapour. It is expected that the secondary fluid will usually be steam, although it should be understood that a suitable hydraulic fluid would suffice. Indeed, suitable fluids are envisaged to be water, air, nitrogen, synthetic and mineral oils, or suitable mixtures such as a water/glycol mixture.
Given that the preferred working fluid for the operation of the engine is steam (as will be explained below), whatever steam generation system is employed for that purpose may also be used to generate useful steam (as the secondary fluid) for the pilot valve. For example, in a preferred form, the steam for both the working fluid and the secondary fluid may be generated in a boiler, as mentioned above.
Boilers can be of many different architectures, but generally consist of a volume in which water is contained, such as a series of tubes. Heat is then applied to the exterior of this volume and is transferred through the walls of the vessel, causing the water to become heated and boil, producing steam. This is then commonly further heated to produce superheated steam. Common types of boilers include firetube boilers, water tube boilers, and flash boilers. In all types, water is typically added continuously or periodically to replenish that boiled off.
The pilot valve preferably operates between two conditions, namely its open condition and its closed condition. When in its open condition, the pilot valve permits passage of the secondary fluid therethrough to act on the inlet valve. In a preferred form, the pilot valve is urged towards its open condition against a closing force, such that the rest position for the pilot valve is its closed condition. An advantage of this arrangement is that the pilot valve can be configured so as to act as an emergency relief valve in the event of boiler overpressure, given that such overpressure will tend to open the valve rather than close it.
The pilot valve may be of any suitable type and may, for instance, be a poppet valve, a spool valve or a flapper valve. Where the pilot valve is a poppet valve, the poppet valve preferably opens by unseating a poppet from its seat, allowing fluid to pass.
Where the pilot valve is a spool valve, the spool valve preferably includes a stepped cylindrical spool in a sleeve that has radial flow ports. In this form, sliding the spool in the sleeve exposes the flow ports to open them. Advantageously, such a valve can be of the overlapped type. This provides a dead zone in the travel of the spool where the inlet valve is not in fluid communication with either the boiler or the exhaust port, thus preventing short-circuiting between the boiler and the exhaust port.
Where the pilot valve is a flapper valve, the flapper valve preferably includes a flapper that swings between two opposing nozzles by a continuous stream of secondary fluid via pressure drop orifices. Each nozzle preferably communicates with respective chambers in the inlet valve, where, in one form, a spool is held central by springs.
Turning now to the inlet valve of the system of the present invention, the inlet valve is preferably of a type that is also operable between open and closed conditions, in the preferred form in response to the action of the secondary fluid from the pilot valve. In its open condition, the inlet valve permits entry of the working fluid to the expansion chamber of the cylinder to do work on the piston as it expands, in the normal manner. Again, the inlet valve is preferably urged towards its open condition (preferably by the secondary fluid) against a closing force, such that the rest position for the inlet valve is also its closed condition.
The inlet valve may also be of any suitable type and will ideally either be a poppet valve or a spool valve. In one form, the inlet valve is a poppet valve and includes a poppet piston running in a cylinder to a poppet stem. The secondary fluid admitted by the pilot valve preferably exerts force on the poppet piston, overcoming a resilient means (such as a spring) which normally holds the poppet shut. This results in the inlet valve opening. Preferably, the area of the poppet piston on which the secondary fluid acts is larger than the poppet area, assuming that the pressures of the secondary fluid and the working fluid are the same.
In this form, the poppet valve may be oriented in either direction relative to the flow of pressurised fluid as it opens. Preferably, the poppet valve is oriented such that the boiler pressure tends to hold it closed. This avoids the need for a strong resilient force to hold it closed, as would be the case if the orientation were reversed. Further, this arrangement assists in avoiding leaks, as the increased pressure results in an increased closing force and thus increased sealing pressure (namely, valve seat contact pressure).
Referring to the actuating means of the system of the present invention, the actuating means preferably controls the operation of the pilot valve between its open condition and its closed condition. Whilst the preferred form of actuating means provides electrical actuation that is electronically controlled, it will be appreciated that the actuating means may be provided by a suitable mechanical, electrical, electromagnetic, piezoelectric or other actuation arrangement. A suitable such arrangement may be one that would give rise to similar precision and speed of operation of the pilot valve as is provided by the electronic means about to be described.
In a preferred form, the actuating means is an electronically controlled solenoid, the electronic control being provided by a control module in association with a timing means. In this form, the control module may include a processing device (such as a microcontroller) which is able to process set and dynamic parameters so as to provide a control signal (via an output port) to the solenoid, the control signal being suitable for actuating or holding the solenoid so as to control the pilot valve between its open and closed conditions.
In a preferred form of the invention, at least some of the dynamic parameters are provided by, or determined using, a signal from the timing means to the control module. The set parameters, on the other hand, may reside on the control module (for example, in FLASH memory, or an EPROM, or memory on-board a microcontroller) such that they are able to be accessed by the processing device. In this form of the invention, the set parameters are effectively pre-programmed into the control module.
The processing of the dynamic parameters preferably provides data such as crank-angle position and speed data, during operation of the engine.
Other dynamic parameters provided to the processing means may be any of the engine's operating conditions, such as the pressure of the working fluid and/or the secondary fluid, or the temperatures and pressures within the cylinder, although these will typically not be provided by the timing means.
The timing means may be any type of rotational position transducer that can provide ‘real time’ crank position data to the processing means. In a preferred form, the timing means will be a timing disc arranged to rotate with the crankshaft of the engine. The timing disc will preferably have pre-set protrusions thereon configured to be representative of pre-determined crank-angle positions. Timing sensors may then be provided that are capable of sensing the passing of respective protrusions to generate timing signals for the processing means in order to determine crank-angle speed and position data.
By pre-programming the control module with set parameters related to, for instance, the delay time between energizing the solenoid and the opening of the pilot valve, the delay time between the pilot valve opening and the inlet valve opening, the delay time associated with gas flow, and variations to these delay times caused by changes in the engine's operating conditions, the processing means is able to determine, during operation, at what time shortly prior to the predicted next TDC time the solenoid should be energized. This permits the solenoid to actuate the pilot valve, which in turn opens the inlet valve, at precisely the required time with respect to the arrival of the piston at TDC.
Preferably, a very high initial voltage is provided to the solenoid, enabling the current, the associated magnetic field, and hence the solenoid plunger retraction force, to build up quickly, minimizing any delay time.
Further, once the solenoid plunger has commenced moving, the voltage and current are preferably lowered to a ‘holding’ value to maintain the plunger in a retracted position (and thus the pilot valve in its open condition) against the resilient means (such as a return spring). In this form, it is not essential to sense when the plunger commences moving—the time may be entered as one of the set parameters.
In the same manner, the control module may be pre-programmed with set parameters related to, for instance, the delay time between de-energising the solenoid and the closing of the pilot valve, the delay time between the pilot valve closing and the inlet valve closing, the delay time associated with gas flow and variations to these delay times caused by changes in the engine's operating conditions. Thus, the control module preferably sends the de-energisation signal to the solenoid shortly prior to the desired inlet valve closing time.
In this respect, and given that to achieve high expansion ratios the inlet valve should only remain open for a short time after TDC, any closing delay time is preferably short. In one form, this may be achieved by including means capable of rapidly dissipating the solenoid field energy to ensure rapid plunger extension under the influence of the resilient means (such as the return spring) when the solenoid de-energises.
Without such a rapid dissipation means, there is a risk that the solenoid de-energisation process would commence before the solenoid is fully energized for opening the pilot valve. This would, of course, lead to the inlet valve not opening fully, or at all, leading to a loss of efficiency.
Finally, the inlet system of the present invention may also be advantageously used to control the pressure that builds up in the dead space in the expansion chamber just before the piston reaches TDC. In one form, a pressure transducer may be included in the expansion chamber to monitor cylinder pressure. This could supply further dynamic parameters to the control module to vary the inlet opening timing slightly. For instance, in the event that the cylinder pressure gets too high in the final movement of the piston to TDC, the control module may energise the solenoid early to open the inlet valve earlier, allowing the pressure build up to vent to the boiler via the inlet valve.
In order to provide a general understanding of the manner of operation of a reciprocating engine having a working fluid inlet system in accordance with the present invention, an in-use scenario will briefly be described.
Once operating, the sequence of operating steps for a reciprocating engine of the steam driven Rankine cycle type will, in general terms, be as follows:
1. As the piston nears TDC, the actuating means operates to open the pilot valve against a closing force, permitting secondary fluid (steam) to move therethrough. The actuating means is preferably the electronically controlled solenoid/timing means arrangement described above, which is capable of predictively controlling the pilot valve between its open and closed conditions, in terms of being open and closed, and also in terms of the rate and timing of opening and closing. 2. The steam then engages with a suitable configured inlet valve, causing the inlet valve to open, again against a closing force. 3. The working fluid (steam) enters the expansion chamber of the cylinder via the inlet valve, expanding and forcing the piston away from TDC on its expansion (power) stroke, towards BDC. 4. The actuating means operates to close the pilot valve, denying steam to the inlet valve, and allowing the closing force to close the inlet valve. 5. Once the piston has passed BDC, it returns towards TDC on its return stroke. Expanded steam within the cylinder exhausts through exhaust valve(s) located in the cylinder wall and/or, more preferably, in the piston head itself. This latter configuration prevents the piston from having to work against the compression of steam in the cylinder during the return stroke, as will be described in more detail below. 6. As the piston again nears TDC, the actuating means again operates to open the pilot valve against the closing force, again permitting secondary fluid (steam) to move therethrough. 7. The cycle of steps 1 to 6 then continues.
In relation to the use of piston head exhaust valves, if utilized the exhaust valves are preferably configured so as to open automatically when the pressure above the piston drops to a threshold pressure above the exhaust port pressure. In this respect, the piston preferably includes exhaust ports associated with the exhaust valves, these piston exhaust ports venting to aligned exhaust ports in the cylinder wall (or the crankcase, if desired).
Preferably, the piston exhaust ports and the cylinder wall exhaust ports are configured to overlap during the entire stroke, allowing exhaust venting at any crank angle provided the exhaust valves are open. In a more preferred form, a conventional exhaust port opened by the piston just before BDC will also be used. This initiates exhausting in the event that cylinder pressure has not dropped sufficiently to allow the piston head exhaust valves to open.
The use of the such an exhaust valve arrangement with the inlet valve system of the present invention, which itself allows very early and sharp cut off, allows an engine to run very efficiently at virtually all load conditions. Indeed, the presence of both arrangements permits the engine to run at different displacements, effectively making it a variable displacement engine. Furthermore, the cylinder can of course be sized such that full expansion of the gas occurs at BDC when operating at full load, which would provide maximum efficiency. Then, at part loads the amount of inlet gas may be reduced such that full expansion occurs before the piston reaches BDC.
With this embodiment of the invention, the piston head exhaust valves would open so that gas could flow in the reverse direction through the valves (that is, into the expansion volume above the piston), thus avoiding doing work to generate a partial vacuum and again maintaining efficiency.
The piston head exhaust valves may be any suitable valves, although it is preferable that they be of a type that is not unduly influenced by the inertia forces generated as a result of the acceleration of the piston. Also, the exhaust valves should be of a type that ensures that the system of closing the valve at TDC does not lead to wear or damage of the valves.
The piston head exhaust valves will thus preferably be springs, and will ideally be reed valves. However, other arrangements could be used, such as poppet valves with compression coil spring arrangements.
Additionally, leaf springs may be used at the head of the cylinder to assist in closing the reed valves and also to cushion the impact of the piston head exhaust valves on the cylinder head. Whilst this impact is cushioned somewhat by the gas that must be expelled from between the faces of the reed valves and the leaf springs as they come into contact, other options to cushion this impact may be used, such as the use of fluid jets emanating from the cylinder head, or a fluid coating on the springs themselves may assist in prolonging the life of the reed valves.
From the above general description, it can be seen that the working fluid inlet system of the present invention provides a simple solution to the operation and control problems that have been associated with many types of reciprocating engines for many years.
In particular, the system of the invention is particularly useful as the inlet valve system for a Rankine cycle heat engine that uses steam as its working fluid to drive a piston. It permits an efficient reciprocating steam engine to be built without the cost, complexity, weight and size of multiple expansion cylinders, because a high expansion ratio can be achieved in one cylinder by providing early cut off.
A further advantage is that the valve timing may be fully programmable. Indeed, unlike many mechanisms, the timing of the admission and cut-off of working fluid to the expansion chamber can be varied independently and over a wide range, without the need for complex mechanisms.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described with reference to a preferred embodiment illustrated in the accompanying drawings. However, it is to be understood that the following description is not to limit the generality of the above description.
In the drawings:
FIG. 1 is a perspective view of a reciprocating engine incorporating a working fluid inlet system in accordance with a preferred embodiment of the present invention;
FIG. 2 shows a cross-section through the reciprocating engine of FIG. 1 ;
FIG. 3 a is an exploded view of a part of the cross-section of FIG. 2 , with the piston nearing TDC;
FIG. 3 b is an exploded view of a part of the cross-section of FIG. 2 with the piston moving away from TDC and towards BDC;
FIG. 3 c is an exploded view of a part of the cross-section of FIG. 2 with the piston approaching BDC;
FIGS. 4 a and 4 b are schematics of a first alternative pilot valve and inlet valve arrangement respectively for use with an embodiment of the present invention;
FIG. 5 is a schematic of a second alternative pilot valve and inlet valve arrangement for use with an embodiment of the present invention;
FIG. 6 is a perspective view of a piston adapted in accordance with a further embodiment of the present invention;
FIGS. 7 a to 7 d are exploded views of part of the cross-section of FIG. 2 , sequentially showing the operation of the piston of FIG. 6 ; and
FIG. 8 is an exploded view of a part of the cross-section of FIG. 2 showing a further embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Illustrated in FIG. 1 is a reciprocating engine 10 that operates on the Rankine cycle and uses steam as its working fluid. The engine 10 is not illustrated with all of the components necessary for operation, as will be explained shortly.
The engine 10 generally includes a boiler 12 suitable to generate the steam necessary for use as the working fluid and, for the preferred inlet system of the present invention, the secondary fluid. In this respect, a skilled addressee will appreciate that suitable flow passages for all aspects of the engine are not necessarily visible in all of the Figures. For example, a flow passage from the boiler 12 to the pilot valve in subsequent Figures is not evident in all cross-sections in the Figures, but of course is present in the engine.
The engine 10 includes a reciprocating piston in a cylinder, with a variable volume expansion chamber, shown generally by reference numeral 14 . The reciprocating piston is operatively connected to an electrical generator 16 via a crankshaft 28 (not completely shown in FIG. 1 ).
FIG. 1 also shows parts of the engine that are unrelated to the present invention, such as the solenoid 22 and the injector pump 24 that regulate the flow of water into the boiler 12 , together with several heat transfer vanes 26 that are associated with the TDC end of the cylinder.
In relation to the inlet system of the illustrated embodiment of the present invention, all that is evident from FIG. 1 is the presence of various aspects of the actuating means that controls the operation of the pilot valve. In particular, FIG. 1 shows the solenoid 18 and the timing disc 20 , the timing disc 20 being operatively connected to the crankshaft 28 . However, in FIG. 2 the timing disc 20 is better illustrated than in FIG. 1 , in that its operative connection to the crankshaft 28 is apparent. Also, the cylinder 30 within which the piston 32 is configured for reciprocating movement (in the normal manner) is more apparent in FIG. 2 than in FIG. 1 .
The elements such as the boiler 12 , the generator 16 , the vanes 26 , and the water inlet solenoid/valve arrangement 22 / 24 are all also evident in FIG. 2 , but will not be described in further detail. Indeed, with regard to the configuration and operation of the piston 32 , the cylinder 30 , the crankshaft 28 , the generator 16 , and their associated engine parts, these will be well understood by a skilled addressee and will not be described in further detail. These elements do not form an essential part of the inlet system of the present invention.
However, the interaction and configuration of the elements within the area marked A in FIG. 2 are important to the present invention and will now be described in further detail in conjunction with the illustrated elements of the actuating means of the present embodiement, namely the timing disc 20 and the solenoid 18 .
The inlet system of the present embodiment is best illustrated in FIGS. 3 a , 3 b and 3 c . In this respect, although these figures provide a sequential illustration of the inlet system (and engine) in different conditions, most of the elements of the inlet system are common to each figure. It is thus suitable to describe those common elements before describing the sequential operation.
Referring simply to FIG. 3 a , the solenoid 18 is operatively connected to a pilot valve that is shown in the form of a poppet valve 34 . Since the solenoid 18 is not attached to the piston to be physically moved thereby, the solenoid can be considered as physically separate from the piston. The poppet valve 34 can be opened by the retraction of the solenoid's plunger 37 (in association with the link member 35 ) against a closing force provided by a spring 36 . When in its open condition, the poppet valve allows passage of secondary fluid (steam) into the chamber 38 of the inlet valve 40 , which in this embodiment is also a poppet valve. Additionally, steam is able to be fed to, for instance, an injector (not shown) via passage 45 .
When the secondary fluid enters the chamber 38 , its pressure unseats the poppet 42 and thus opens the inlet valve 40 against a closing force provided by a spring 44 . Working fluid (steam) is then able to enter the cylinder pre-chamber 46 via steam feed-lines 48 from the boiler 12 .
When the solenoid 18 is de-energised, the closing force of spring 36 closes the poppet valve 34 , shutting off the steam to the inlet valve chamber 38 , which in turn allows the closing force of spring 44 to shut off steam to the expansion chamber. In this respect, it should be noted that steam is able to exhaust from the inlet valve chamber 38 via a port 39 to a system condenser, as necessary.
In relation to the timing of the operation of the solenoid 18 , and returning to FIG. 1 , the timing disc 20 includes two upper protrusions 52 and 54 and a lower protrusion (not shown) on the underside of the disc about 30° around from protrusion 52 .
Sensors 56 and 58 sense the protrusions as the timing disc rotates with the crankshaft 28 . Protrusion 54 passes sensor 56 at TDC (as is evident by the position of the piston 32 in FIG. 2 ), whilst protrusion 52 passes this sensor 90° before TDC. The times of these protrusions passing these points are recorded as dynamic parameters in a control module (which may include a microcontroller), which is a part of the actuating means of the present invention.
The control module, as mentioned above, is then able to calculate the appropriate time to energise the solenoid, in light of the known delay time of the solenoid due to its inductance, and the inertia and pressure forces of the pilot and inlet valves, to open the inlet valve at or near TDC as required. With appropriate programming of suitable set and dynamic parameters, the control module will do this accurately despite fluctuations in speed over the cycle, and despite increases or decreases in the speed of the engine.
The lower protrusion (not shown), passes sensor 58 at some time after TDC (in this embodiment, at about 30°). This assists the control module to determine the time to de-energise the solenoid 18 to close the inlet valve, again in light of known delay times. In this respect, it will be appreciated that angles smaller or larger than 30° could be used in order to provide large and small expansion ratios respectively.
Referring now to the sequential comparisons between FIGS. 3 a , 3 b and 3 c , the basic operation of the engine becomes clear.
As already mentioned, FIG. 3 a shows the piston 32 nearing TDC (or having just arrived at TDC) in the cylinder 30 . The solenoid 18 is de-energised such that the pilot valve is in its closed condition by virtue of the spring 36 having closed the poppet valve 34 . Secondary fluid (steam) is thus denied to the inlet valve 40 and working fluid is thus denied to the expansion chamber.
In FIG. 3 b , the solenoid 18 has energised to open the poppet valve 34 against the closing force of the spring 36 , allowing steam to enter the inlet valve chamber 38 . This steam has opened the inlet valve 40 against the closing force of its spring 44 to permit working fluid (steam) to enter the expansion chamber via pathways 43 . In FIG. 3 b , the expansion of this steam has urged the piston away from TDC (towards BDC) on its expansion (power) stroke.
In FIG. 3 c , the solenoid 18 has again de-energised to close the inlet valve 40 during the last of the expansion stroke and for the entire return stroke.
Illustrated in FIGS. 4 a , 4 b and 5 are alternative pilot valve and inlet valve arrangements that are also suitable for use with the inlet system of a preferred embodiment of the present invention.
FIG. 4 a shows a pilot valve in the form of a spool valve 60 . The cylindrical spool 62 is actuated by a solenoid (or another suitable mechanical, electromagnetic, or piezoelectric actuator) at X against the return force of a resilient means in the form of a spring 64 . In FIG. 4 a , the spool valve is shown in its closed condition, preventing entry of secondary fluid (steam) into inlet port 64 and then to the outlet port 66 . FIG. 4 a also illustrates the preferred overlapped configuration of the central spool 65 with respect to the stepped entry 67 to the outlet port 66 , which avoids any short-circuiting between the inlet port 64 and the low pressure return port 68 .
Once energized, the solenoid moves the spool valve to its open condition that, in terms of FIG. 4 a is to the left of the page, allowing the secondary fluid (steam) to pass therethrough. Upon de-energisation, and upon the return of the spool valve to its closed condition, remaining steam in the valve exhausts via the low pressure return port 68 .
FIG. 4 b shows an inlet valve, also in the form of a spool valve, which operates in a similar manner. However, the spool valve 70 is actuated by the inflow of secondary fluid (steam) to the chamber 72 from the outlet port 66 of the pilot valve.
Again, the spool valve 70 is opened against a return force provided by a resilient means in the form of a spring 74 . The high pressure working fluid (steam) enters the spool valve 70 via inlet port 76 when in its open condition, and travels through the spool valve 70 to the outlet port 78 for entry to the working chamber of the cylinder of the engine.
The arrangement illustrated in FIG. 5 differs from the arrangement in FIGS. 4 a / 4 b by the replacement of the spool arrangement of the pilot valve with a flapper arrangement The flapper arrangement 82 includes a flapper 84 that swings between opposing nozzles 86 , 88 due to a continuous stream of secondary fluid (steam) entering via inlet pressure drop orifices 90 , 92 .
Each nozzle 86 , 88 communicates with a respective chamber 94 , 96 at each end of the inlet valve, which is itself a spool valve 98 of the same general type as described above. In this arrangement, the cylindrical spool 100 is held central by respective resilient means in the form of springs 102 , 104 .
As the back pressure of the nozzles 86 , 88 differs when the flapper 84 is in a non central position, the flapper itself being electro-magnetically driven by coils 106 , 108 , the spool 100 is pushed from one side to the other against the centering force of the springs 102 , 104 by the pressure imbalance.
Alternatively, instead of the use of the centering springs 102 , 104 at each end of the spool 100 , a centering feedback spring connected to the flapper may be used.
As will be appreciated, there are various advantages and disadvantages of the different valve arrangements and combinations described in FIGS. 4 a , 4 b and 5 , which will usually dictate, for particular applications, which configurations will be most suitable.
Referring now to the further embodiment illustrated in FIG. 6 , illustrated is a piston adapted to include exhaust valves in its head, the exhaust valves being in the form of reed valves 33 associated with exhaust ports 35 . In this form, the piston mounted exhaust valve operating sequence is preferably as follows:
1. As the piston travels downwards under the force of expanding gas above it (as shown in FIG. 7 a ), the pressure will gradually drop until the pressure differential above the exhaust port pressure is not sufficient to hold the reed valves closed. At this point, the reed valves will open, which at full load operation will occur just before BDC. It will be noted that opening of these valves is assured by exhaust ports 37 in the cylinder wall opening (or becoming accessible) just before BDC. If the gases have not fully expanded, this can cause the pressure drop required for the reed valves to open. 2. FIG. 7 b shows the piston just before BDC but before the cylinder wall exhaust ports 37 have been exposed, with the reed valves 33 already open. 3. FIG. 7 c shows the piston at BDC with the reed valves 33 open. 4. As the piston travels upwards from BDC, the reed valves 33 stay open, allowing all of the gas above the piston to vent through it and out through the ports 37 without a substantial build up of pressure. 5. As the piston nears TDC, leaf springs 139 mounted on the cylinder head (or integral with the head itself contact the reed valves 33 , causing the reed valves 33 to close at or before TDC, as illustrated in FIG. 7 d . If the reed valves 33 close before TDC, some compression of the remaining gases will occur. 6. At this stage, the inlet valve will be open and high pressure gas will enter the relatively small compression volume. As the piston moves away from TDC this gas will hold the reed valves 33 shut, enabling the gas to work against the piston on its downward stroke.
It will be appreciated that this valve arrangement allows maintenance of full uni-flow operation.
Illustrated in FIG. 8 is a further embodiment, related to the recovery of energy from the inlet valve system, particularly from the operation of the pilot valve and the secondary fluid used to actuate the inlet valve. In this respect, it will be appreciated that the energy used to operate the inlet valve can be significant.
Often the inlet valve will be actuated (via the pilot valve) using a high pressure (secondary) fluid. Where this secondary fluid is compressible, its use may occur without appreciable expansion of the fluid, and some of this energy can be recovered by venting this fluid into the expansion chamber of the cylinder when the inlet valve closes. Ideally, this coincides with the early part of the expansion stroke, allowing the additional fluid to do work against the piston.
FIG. 8 shows an arrangement that vents the secondary fluid into the expansion chamber. When the pilot valve closes, the secondary fluid above the pilot valve exits via a pilot valve exhaust port 120 and then passes via a check valve 122 into the expansion chamber. As the expansion chamber is at high pressure at this time, this may hinder the closing the inlet valve. To assist in preventing this, an additional volume is connected to the exhaust passage upstream of the check valve. This will allow the gas to expand to an intermediate pressure immediately, allowing the inlet valve to shut as required.
When the pressure of the gas in the expansion chamber has dropped sufficiently, this stored gas will then start to exit via the check valve into the expansion chamber.
Finally, it will be appreciated that there may be other variations and modifications made to the configurations described herein that are also with the scope of the present invention.
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The invention relates to a reciprocating engine and a working fluid inlet system therefore. The engine includes at least one cylinder with a reciprocating piston therein and a variable volume expansion chamber capable of receiving a working fluid via an inlet valve. The inlet system includes a pilot valve having an open condition and a closed condition. In the open condition, the secondary fluid passes therethrough to act on the inlet valve. The system also includes an actuating means for controlling the condition of the pilot valve. The inlet valve is adapted to open in response to the action of the secondary fluid. The engine may also include exhaust means, possibly by porting in the piston and a cylinder wall. The working fluid may be used as the secondary fluid.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. provisional application Ser. No. 60/057,947 filed on Sep. 5, 1997, which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A MICROFICHE APPENDIX
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to certain means of counteracting the negative effects of mechanical resonances on the operation of stepper motors. More particularly, it concerns the reduction of the effects on stepper motors of resonant wave(s) in a machine or device to which a stepper motor is attached. As used hereafter, the term "stepper motor" refers primarily to the "hybrid" type stepper motor; however, the same principles would also apply to the permanent magnet, variable reluctance, canstack, axial airgap and other types of stepper motor designs where the stator is mechanically affixed to the outer motor housing.
Such waves are the natural result of mechanical resonance(s) in any particular machine or device. These mechanical waves of energy, when coupled to a stepper motor's rotor assembly (through the motor output shaft) and/or stator assembly (through the motor's case) can substantially increase the amount of energy required for a stepper motor to continue its rotational movement from one magnetic pole to the next. The result can range from an increase in the electrical energy required by the stepper motor for the same amount of output torque (at a given speed), to the complete stalling of the stepper motor.
The present invention consists of an apparatus and method for counteracting the negative effects on the operation of a stepper motor of mechanical resonances in a particular machine or device. The primary results of the present invention is a substantial increase in a stepper motor's speed range and a significantly improved torque curve.
2. Description of the Background Art
It is well known in the field of stepper motors that each particular stepper motor will have one or more resonant points over its frequency range of operation. The size, mechanical construction, air gap and many other physical characteristics of a stepper motor vary over a wide range, thereby resulting in a divergence of inherent stepper motor resonances. There are also mechanical resonances in any machine or device to which a stepper motor may be attached.
When a stepper motor is attached to any machine or device, the stepper motor, along with such machine or device, become one system that will have its own unique mechanical resonances. These "system" resonances can cause problems with the operation of a stepper motor, including increased demand at certain operating frequencies for electrical energy (for the same torque output), to the complete stalling of the stepper motor.
To date, there have been very limited and rather unsuccessful efforts to counteract the negative effects of such stepper motor/machine system resonances. Rather, it is the custom in the industry to operate a particular stepper motor within a frequency range in which it is not seriously affected by any system resonance.
Another common industry approach to the problem of system resonances has been to use an isolation mounting technique similar to that used in the mounting of a variety of mechanical devices, including internal combustion engines, transmissions, and other types of electrical motors. This approach involves the partial separation of the stepper motor from the machine or device by means of a flexible standoff, usually made from rubber (or similar flexible material), that lowers the total energy of the mechanical waves moving towards or from the stepper motor in the direction parallel to the stepper motor's rotor assembly. Such isolation mounting devices operate within a limited frequency range (depending upon the type and shape of the isolating material), and are directed at reducing the amount of transmitted and reflected energy that is moving in a linear direction parallel with respect to the stepper motor's rotor; such types of isolation mounts do not significantly affect the amount of mechanical wave energy that is transmitted to or from the stepper motor in a direction that is perpendicular to the stepper motor's rotor assembly (i.e., mechanical waves moving energy clockwise or counterclockwise with respect to the motion of the rotating rotor assembly of the stepper motor).
Another common industry approach is the use of viscous dampers placed on the output shaft of the stepper motor. These are designed to act in a manner similar to a flywheel by temporarily smoothing out short term various in torque. However, such devices, like isolation mounts, do not directly deal with the problem of the mechanical waves interfering with the relationship of the stator assembly and the rotor assembly inside the stepper motor. They also have the disadvantage of adding drag to the output shaft at all speeds, thereby wasting energy. Lastly, they do not significantly improve dynamic speed range, but in fact, may decrease maximum speed capability.
BRIEF SUMMARY OF THE INVENTION
To overcome the foregoing deficiencies, the present invention is specifically designed to counteract the effect of mechanical waves moving clockwise or counterclockwise to the rotor assembly of the stepper motor, thereby substantially decreasing the amount of energy at a resonance point that a stepper motor must use to continue its rotational movement with the same amount of torque. This invention has the advantage of requiring less energy into the stepper motor and a very substantial increase in dynamic speed range (increases of over 100% have been observed).
In accordance with an aspect of the invention, the effect of mechanical energy waves that exert rotational forces upon the rotor assembly of a stepper motor that are detrimental to the torque output and dynamic speed range of said stepper motor is reduced by employing a mounting bracket that is capable of holding a stepper motor in a manner that permits the stator assembly of the stepper motor to rotate clockwise or counterclockwise relative to the rotor assembly, depending upon the direction and amount of force on the rotor assembly exerted by said mechanical energy waves, and further providing means for adjusting the amount of clockwise or counterclockwise rotation of the stator assembly in response to the mechanical energy waves.
In accordance with another aspect of the invention, the effect of mechanical energy waves that exert rotational forces upon the rotor assembly of a stepper motor that are detrimental to the torque output and dynamic speed range of said stepper motor is reduced by providing a stepper motor housing that is capable of permitting the stator assembly in the stepper motor to rotate clockwise or counterclockwise relative to the rotor assembly in the stepper motor in a manner that depends upon the direction and amount of force on the rotor assembly exerted by the mechanical energy waves, and further providing means for adjusting the amount of clockwise or counterclockwise rotation of the stator assembly in response to the mechanical energy waves.
An object of the invention is to reduce the effects of resonant mechanical waves that exert clockwise or counterclockwise forces that act upon the output shaft of a stepper motor such that the dynamic relationship between the stator assembly and rotor assembly in a stepper motor is adversely affected, thereby reducing torque or even stalling the stepper motor.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
FIG. 1 schematically shows a stepper motor in cross-section connected to an external power switching circuit.
FIG. 2 shows a front view of a clasp for mounting a stepper motor in accordance with the invention, attached to a stepper motor.
FIG. 3 shows a side view of a clasp for mounting a stepper motor in accordance with the invention, attached to a stepper motor.
FIG. 4 shows a front view of a flange for mounting a stepper motor in accordance with the invention, attached to a stepper motor.
FIG. 5 shows a side view of a flange for mounting a stepper motor in accordance with the invention, attached to a stepper motor.
FIG. 6 schematically shows a stepper motor in cross-section that has been modified with a flexible coupling between the external housing and frame and the stator assembly in accordance with the invention and connected to an external power switching circuit.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 6. It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to details and the order of the steps, without departing from the basic concepts as disclosed herein.
Referring to FIG. 1, in a stepper motor 1, the stator assembly 2 is affixed, and stationary with respect to, the stepper motor's 1 external housing and frame 3. The rotor assembly 4 is mounted on the stepper motor's 1 output shaft 5. The positional relationship of the rotor assembly 4 to the stator assembly 2 is critical to the operation of a stepper motor 1. In a stepper motor 1, the magnetic poles 6(a) of the stator assembly 2 are energized by means of electric coils 7 wrapped around the magnetic poles 6(a) that are attached to an external power switching circuit 8. The electric coils 7 are energized in a particular sequence that causes the magnetic poles 6(b) on the rotor assembly 4 to be alternatingly attracted and repelled to the magnetic poles 6(a) on the stator assembly 2, thereby causing the rotor assembly 4 to move with respect to the stator assembly 2. Consequently, the output shaft 5 turns in relationship to the stepper motor's 1 external housing and frame 3.
When the stepper motor 1 is attached to any type of machine or device, the stepper motor 1 becomes mechanically coupled to such machine or device. This attachment will create a new mechanical system with its own unique physical properties that are a result of the combination of the stepper motor 1 and the attached machine or device. With respect to this invention, the most important element of the physical properties of such a "system" is the frequency(ies) of mechanical resonance(s) that such a system has.
When such a mechanical system nears a resonance point, very strong mechanical waves arise. If such a resonant mechanical wave is transmitted perpendicular to the rotary motion of the output shaft 5 of stepper motor 1, then it can strongly affect the physical relationship between the stator assembly 2 and the rotor assembly 4 due to the very large increase in the amount energy required for a magnetic pole 6(b) on the rotor assembly 4 to reach the next magnetic pole 6(a) on the stator assembly 3. To overcome this increased resistance, the existing industry technique has been to apply more energy to the electrical coils 7 by the power switching circuit 8.
At lower switching frequencies, most stepper motors 1 and power switching circuits 8 have sufficient reserve capacity to apply enough extra energy to the electrical coils 7 to overcome the effects of a resonance wave below 1,000 to 4,000 pulses per second, depending upon the particular stepper motor 1. However, at higher switching speeds (which is relative to the particular stepper motor 1), the power switching circuit 8 is not able to overcome the problem of resonance and the stepper motor 1 will operate at very reduced torque and/or stall at or near a resonance point.
The present invention approaches the resonance wave problem in an entirely different manner. By designing the mounting bracket for stepper motor 1 in such a manner as to permit a small amount of rotational movement of the external housing and frame 3 with respect to the rotor assembly 4, the physical relationship of stator assembly 2 and the rotor assembly 4 is also allowed to change. This enables the magnetic pole 6(a) of the stator assembly 2, towards which the magnetic pole 6(b) of rotor assembly 4 is traveling, to stay in the same relative physical position (or relationship) to the approaching magnetic pole 6(b) of rotor assembly 4 as happens at non-resonant frequencies, thereby using less energy than would otherwise be required bring the two magnetic poles 6(a) and 6(b) into alignment. This lower energy threshold is sufficient in most cases to enable the stepper motor I to continue operating normally rather than lose torque or stall without having to apply more energy to the electrical coils 7. Once the stepper motor 1 increases or decreases switching speed above or below the resonant mechanical frequency, the external housing and frame 3 returns to its original position. The stator assembly 2 and the rotor assembly 4 are then able to continue operating in a normal manner.
The present invention can be implemented both externally to, and internally in, the stepper motor 1. First, referring to FIG. 6, it can be incorporated into the stepper motor 1 itself; and second, referring to FIGS. 2 and 5, the invention can be incorporated into a variety of external mounting devices or brackets for holding stepper motor 1 to the particular machine or device. Similarly, referring to FIG. 2 through FIG. 4, a variety of flexible materials can be utilized to obtain a small amount of rotation of the external housing and frame 3 (and thus, stator assembly 2) with respect to the rotor assembly 4. Different materials (with different amounts of compliance) may have varying results on the performance. Experimentation to find the optimum materials for a particular size and type of stepper motor 1 for use on a particular machine or device would be an expected part of the utilization of this invention.
The physical implementation of this invention, either externally to stepper motor 1 or internally in stepper motor 1 may be accomplished in many ways. Three means will be briefly described here by way of example, but not limitation. Referring to FIG. 2, a stepper motor 1 of standard construction can be held in a specifically designed mount 9 such as that shown diagrammatically. This type of mount basically acts like a clasp that holds the stepper motor 1 in place by the external housing and frame 3, yet allows for a small amount of rotation of the external housing and frame by means of the compliance characteristic of the rubber 10 (or other similar compliant material) placed between the mount 9 and the stepper motor 1.
Referring to FIG. 5, a stepper motor 1 can be mounted with a flange 11 that is made of two pieces 12(a) and 12(b) that are free to rotate a small amount with respect to each other by means of a flexible connecting material 13. Flange 11 will enable the stepper motor 1 to be firmly attached to a machine or device in a manner almost identical to that of using the mounting holes typically provided in the external housing and frame 2, yet still allow the external housing and frame 2 to rotate a small amount with respect to the rotor assembly 4.
Referring to FIG. 6, a stepper motor 1 can be manufactured in a manner as shown that separates the industry standard external housing and frame 3 from the stator assembly 2 by means of a flexible coupling material 14, but that holds external housing and frame 3 to the stator assembly 2 in such a manner as to permit a small amount of rotation between the stator assembly 2 and the rotor assembly 4.
Although the description above contain many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents.
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An apparatus and method for the reduction of the effects of resonant mechanical waves that exert clockwise or counterclockwise forces that act upon the output shaft of a stepper motor such that the dynamic relationship between the stator and rotor in a stepper motor is adversely affected, thereby reducing torque or even stalling the stepper motor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional patent application No. 60/826,924 filed Sep. 26, 2006; the entire disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates generally to methods for separating nucleic acids such as genomic DNA, plasmid DNA and mRNA from contaminating cellular components such as proteins, lipids, soluble membrane components and the like. In particular, the invention relates to the improved process for anion exchange based purification of nucleic acids, such that a resin equilibration step is eliminated from the separation protocol. The invention further improves the recovery of nucleic acids by the addition of a composition that increases the pH of the elution solution.
BACKGROUND OF THE INVENTION
[0003] The last three decades has seen considerable effort in the development of improved methods for the isolation and purification of nucleic acids from biological sources. This has been due mainly to the increasing applications of nucleic acids in the medical and biological sciences. Genomic DNA isolated from blood, tissue or cultured cells has several applications, which include PCR, sequencing, genotyping, hybridization and southern blotting. Plasmid DNA has been utilized in sequencing, PCR, in the development of vaccines and in gene therapy. Isolated RNA has a variety of downstream applications, including blot hybridization, in vitro translation, cDNA synthesis and RT-PCR.
[0004] The analysis and in vitro manipulation of nucleic acids is typically preceded by a nucleic acid isolation step in order to free the nucleic acid from unwanted contaminants which may interfere with subsequent processing procedures. For the vast majority of procedures in both research and diagnostic molecular biology, extracted nucleic acids are required as the first step. In a typical DNA extraction protocol, cells or homogenized tissue samples containing the nucleic acid of interest are harvested and lysed using standard methods, for example using enzymes such as Proteinase K and lysozyme; detergents, such as SDS, Brij, Triton X100, or using other chemicals such as sodium hydroxide, guanidium isothiocyanate, etc. (See for example, Sambrook et al, Molecular Cloning—A Laboratory Manual 2nd edition 9.14 (New York: Cold Spring Harbor Laboratory 1989). Following removal of the cellular debris, the crude lysate is treated with organic solvents such as phenol/chloroform to extract proteins. RNA may be removed or reduced if required by treatment of the enzymes such as RNAse. However, the presence of contaminants such as salts, phenol, detergents and the like can interfere with many downstream manipulations for which the nucleic acid is intended.
[0005] Currently several procedures are available for the chromatographic purification of DNA (genomic and plasmid) and RNA, for example, by employing silica based membrane purification, size exclusion chromatography, reversed phase chromatography, gel filtration, magnetic bead based purification, or ion-exchange chromatography. Ion exchange chromatography is one of the most commonly used separation and purification methods and has been used for purification of plasmid DNA, genomic DNA and RNA.
[0006] See for example, U.S. Pat. No. 6,410,274 (Bhikhabhai), U.S. Pat. No. 6,310,199 (Smith et al), U.S. Pat. No. 6,090,288 (Berlund et al), U.S. Pat. No. 5,990,301 (Colpan et al), U.S. Pat. No. 5,856,192, U.S. Pat. No. 5,866,428 (Bloch), U.S. Pat. No. 5,80,1237 (Johansson), EP 1125943 b1 (Macherey-Nagel GmbH & Co), EP 992583 B1, EP 616639 (Qiagen), U.S. Pat. No. 5,707,812, U.S. Pat. No. 5,561,064 (Vical Inc.).
[0007] While anion exchange chromatographic procedures for the purification of nucleic acids have been extensively referenced, one of the shortcomings of current protocols is the impaired recovery of nucleic acid during the elution step, (Endres, H. N. et al, Biotechnol. Appl. Biochem., (2003), 37(3), 259-66; Prazeres, D. M. et al, J.Chromatog. A. (1998), 806(1), 31-45; Urthaler J. et al, Acta Biochim.Pol., (2005), 52(3), 703-11; Ferreira, G. N. et al, Bioseparation, (2000), 9(1), 1-6.; Ferreira, G. N., et al, Biotechnol. Prog., (2000), 16(3), 416-24. Addition of organic agents such as polyols and alcohols during adsorption and desorption has been shown to improve selectivity and recovery during anion exchange purification of DNA (Tseng, W. C. et al, J. Chromatogr. B Analyt. Technol. Biomed. Life Sci., (2003), 791(1-2), 263-72). However, there appear to be no reports that specifically address the recovery issues often seen during DNA desorption from anion exchange resins. The present invention addresses this problem since it relates to improving recoveries of bound DNA from anion exchange resins. In particular, the invention allows improved desorption of the DNA from the solid support without further manipulation of the protocol.
[0008] Plasmid DNA, genomic DNA and RNA have similar charge properties to one another and are polyanions having high charge density. Binding to positively charged ion exchange resins is therefore possible in the presence of up to 0.7M sodium chloride, depending on the length and conformation of the nucleic acid to be adsorbed. An increase in nucleic acid length as well as double stranded conformation results in an increase in binding strength between the nucleic acid and the anion exchanger. However, this effect is only proportional to nucleic acid length up to about 2 kilobases. The very strong interaction between the negatively charged phosphate backbone of the nucleic acid and ion exchange resin hampers elution of the nucleic acid using conventional methods, where a simple increase in ionic strength of the salt eluant is sufficient for recovery of 70-100% of the bound material. However, in the case of longer chain nucleic acids, an increase in ionic strength up to 3M salt only allows recoveries of 20-50% of the bound nucleic acid. Recovery of the remaining bound material can be accomplished with a combination of high salt concentration and elevated pH using sodium hydroxide. However, sodium hydroxide is not only caustic, but may also lead to irreversible denaturation of nucleic acids and degradation over time.
[0009] Currently, ion-exchange resin is either provided in dried format (silica based resins) or in water in the presence of antimicrobial growth inhibitors. The resin is equilibrated with sample loading solution when the purification protocol is carried out. It is advantageous to simplify the process by eliminate this resin equilibration step.
BRIEF DESCRIPTION OF THE INVENTION
[0010] Surprisingly, it has now been found that nucleic acids can be efficiently eluted from anion exchange resins under conditions of high salt concentration and the presence in the elution solution of an additive that increases the pH of the solution, the pH of the solution being suitably in the range of about pH 9 to about pH 13, and more preferably in the range of about pH 11 to about pH 12. One example of an additive is guanidine or a guanidine-like derivative. Another example is a potassium carbonate. The addition of either additive to the elution solution has been shown to improve recovery of nucleic acids from anion exchange resins from 20-50% to 70-95%.
[0011] Thus, in a first aspect the present invention provides a method for the separation and/or purification of a nucleic acid from cells, comprising:
a) generating an aqueous solution containing the nucleic acid by lysing said cells with a lysis solution; b) contacting the aqueous solution containing the nucleic acid with an anion exchanger bound to a solid support matrix under conditions such that the anion exchanger binds the nucleic acid; and c) eluting the anion exchanger with an aqueous mobile phase comprising a nucleic acid elution salt solution;
characterised in that the elution solution comprises an additive such that the pH of the aqueous mobile phase is between about pH 9 and about pH 13, wherein the presence of the additive in the elution solution provides an increase in the nucleic acid recovery from the anion exchanger, as compared with the recovery of the nucleic acid in the absence of the additive.
[0015] Thus, the present invention provides a method for the use of a compound as an additive to the elution solution to allow high recovery of nucleic acids from anion exchange resins without impairing the nucleic acid stability as compared with conventional ion exchange chromatographic procedures. Nucleic acids, consist of a chain (or a paired chain of deoxyribose phosphate monomers covalently linked via phosphodiester bonds, each sugar phosphate moiety carrying a single aromatic heterocyclic base: adenine (A), guanine (G), cytosine (C), thymine (T found solely in DNA), and uracil (U found solely in RNA). In aqueous solutions of a pH>2, the highly soluble hydrophilic sugar-phosphate polymer backbone contributes one negative charge for each phosphodiester group, with the exception of the terminal phospho-monoester, which may carry up to two negative charges. DNA is thus a polyanion, where the net negative charge of the nucleic acid molecule is related directly to chain length. Nucleic acids therefore, display strong binding affinities to anion exchange resins such that a high salt concentration in the elution solution is required to efficiently remove the nucleic acid from the resin.
[0016] The positive impact of guanidine and guanidine-like compounds particularly arginine on recovery of nucleic acids from anion exchange resins is most pronounced at alkaline pH, for example, between about pH 9 and about pH 13, more particularly at pH values between about 10 and 12. A pH range of between about 10.5 and 11.6 appears to provide optimum recovery. Recovery of nucleic acids is highest when arginine or guanidine carbonate is added to the elution solution. Without being bound by theory, one of the unique properties of the guanidinium group is its delocalized positive charge property which is due to the conjugation between the double bond and the nitrogen lone pairs. The guanidinium group is able to form multiple hydrogen-bonds preferentially with guanine bases, which may act to cause local deformation of the nucleic acid structure, which change in conformation of nucleic acids contributes to a change in desorption kinetics thereby favouring high recoveries of nucleic acids during anion exchange chromatography. Macromolecules are known to bind to adsorptive surfaces through multiple points of attachment creating microenvironments on chromatography media surfaces, which allow adsorption that can become close to irreversible with conventional desorption techniques. While traditional anion exchange chromatography allows the elution of bound molecule from the positively charged ligand through an increase in competing salt anions, it has been observed that elution of nucleic acids, especially high molecular weight (HMW) nucleic acids (above 0.1 kilobases), is not efficient with salt anions alone. It has also been observed that the cation used as a counter ion, as well as the pH of elution has an effect on recovery of HMW nucleic acids, the use of strongly alkaline (such as with sodium hydroxide) may be detrimental to recovery because of the co-elution of contaminants and detrimental effects on product stability.
[0017] In one embodiment, the additive is a compound having the formula (I)
[0000]
[0000] (and more particularly the carbonate or bicarbonate salt thereof), where R is selected from H, and lower alkyl, optionally substituted by amino. Suitably, lower alkyl is a C 1 to C 4 alkyl group, for example methyl, ethyl, propyl and butyl, preferably, methyl or ethyl. Where R is an amino-substituted lower alkyl group, examples of the compounds according to formula (I) include 2-aminoethyl-guanidine, 3-aminopropyl-guanidine and 4-aminobutyl-guanidine (agmatine). In a particularly preferred embodiment, R is hydrogen, thus compound (I) is guanidine, as its carbonate or bicarbonate salt.
[0018] In a second embodiment, the additive is a compound having the formula (I):
[0000]
[0000] wherein R is the group:
[0000]
[0000] where n is 1, 2 or 3, preferably 3. In this case, the additive is arginine, suitably L-arginine, D-arginine, or a mixture of both optical isomers.
[0019] In a third embodiment, the additive is an inorganic salt that provides a similar pH. An example of such a salt is potassium carbonate. Another example is sodium carbonate.
[0020] In embodiments according to the invention, it is preferred that the guanidine and guanidine-like compound or the potassium carbonate is present as an additive in the elution solution at a concentration of between 0.1 and 2 Molar, preferably between 0.25M and 0.5M. The elution solution will typically comprise a salt solution, suitably between about 0.7 M and 3M to which the additive is added. Suitably, the pH of the aqueous mobile phase is between about pH 9 and about pH 13, the preferred range of pH being between about pH 10 and about pH 12, more preferably between about pH 10.5 and about pH 11.6.
[0021] The term “nucleic acid” as used herein refers to any DNA or RNA molecule, or a DNA/RNA hybrid, or mixtures of DNA and/or RNA. The term “nucleic acid” therefore is intended to include genomic or chromosomal DNA, plasmid DNA, amplified DNA, total RNA and mRNA. The process according to the present invention is particularly suitable for the preparation and/or purification of genomic DNA derived from complex mixtures of components derived from cellular and tissue samples from any recognised source, including normal and transformed cells, with respect to species (e.g. human, rodent, simian), tissue source (e.g. brain, liver, lung, heart, kidney skin, muscle) and cell type (e.g. epithelial, endothelial, blood).
[0022] Furthermore, the present method is suitable for the preparation and/or purification of genomic DNA having a size of from about 0.1 kilo-bases to about 200 kilo-bases, or of plasmid DNA, cosmid, BAC or YAC. The present invention is useful for purifying plasmid DNA and cosmid DNA, in particular for downstream applications in molecular biological research, such as cloning and sequencing, gene therapy and in diagnostic applications both in vivo and in vitro.
[0023] Anion exchange resins suitable for use with methods of the present invention include both strong anion exchangers and weak anion exchangers, wherein the anion exchange resin suitably comprises a support carrier to which charged or chargable groups have been attached. The ion exchange resin may take the form of a bead, a membrane or a surface. Examples of strong anion exchange resins include Q-sepharose fast flow resin, Q-sepharose XL and CaptoQ. Examples of weak ion exchange resins include ANX fast flow resin and DEAE Sephadex A25 resin. (GE Healthcare)
[0024] By employing an additive disclosed above in the aqueous mobile phase it is possible to increase recovery of nucleic acid from the anion exchanger of at least 40% and typically between about 40% and about 400%, as compared with the recovery of said nucleic acid from the same anion exchanger and in the absence of the additive in the elution solution, all other conditions being equal.
[0025] In a second aspect, the invention provides a kit for the separation and/or purification of nucleic acid from a cellular sample, the kit comprising a lysis solution for generating an aqueous solution containing the nucleic acid from the cellular sample; an anion exchanger bound to a solid support matrix for binding the nucleic acid; an elution solution for eluting the nucleic acid from the anion exchanger; and optionally desalting means for desalting the eluted nucleic acid. Suitably there is present in the elution solution an additive such that the pH of said elution solution is between about pH 9 and about pH 13.
[0026] In one embodiment, the additive is arginine. In another embodiment the additive is guanidine present as its carbonate or bicarbonate salt. In yet another embodiment, the additive is potassium carbonate.
[0027] Preferably, the anion exchanger is ANX fast flow resin. Alternatively the anoin exchanger is DEAE Sephadex A25 resin, Q-sepharose fast flow resin, Q-sepharose XL and CaptoQ (all from GE Healthcare).
[0028] In a third aspect, the invention provides a further improved process for the separation and purification of nucleic acids. Specifically, in the method for the separation and/or purification of a nucleic acid from cells, comprising: a) generating an aqueous solution containing the nucleic acid by lysing the cells with a lysis solution; b) contacting the aqueous solution containing the nucleic acid with an anion exchanger under conditions such that the anion exchanger binds the nucleic acid; c) eluting the nucleic acid from the anion exchanger with an aqueous mobile phase comprising a nucleic acid elution solution; and d) desalting the eluted nucleic acid; the improvement comprises providing the anion exchanger in a pre-packed column, wherein the column is packed using a salt solution with an antimicrobial agent, further wherein the salt concentration used in packing the column is similar to the salt concentration in the aqueous solution of the contacting step, and wherein the column does not need equilibration prior to said contacting step.
[0029] The pre-packed anion exchange column according to an aspect of the invention is packed with a salt solution. The salt concentration in the solution is similar to the salt concentration of the column loading solutions, such that there is no need to equilibrate the column prior to loading the DNA sample preparation. This simplifies the nucleic acid purification process and improves the efficiency. An antimicrobial growth agent is included in the column packing solution to ensure long term storage of the anion exchange column. An example of a suitable salt is sodium chloride. An example of a suitable antimicrobial agent is ethanol.
[0030] One embodiment of the invention further includes an elution solution with a composition such that the pH of the solution is between about pH 9 and about pH 13. The presence of this composition in the elution solution provides an increase in the nucleic acid recovery from the anion exchanger, as compared with the recovery of nucleic acid in the absence of the composition. One example of such a composition is potassium carbonate, another is arginine, yet another is guanidine carbonate.
[0031] In a fourth aspect, the invention provides a kit for the separation and/or purification of nucleic acid from a cellular sample, the kit comprising a lysis solution for generating an aqueous solution containing the nucleic acid from the cellular sample; an anion exchanger for binding the nucleic acid; an elution solution for eluting the nucleic acid from the anion exchanger; and optionally desalting means for desalting the eluted nucleic acid. Suitably the anion exchanger is packed as a column with a salt solution with an antimicrobial agent, and wherein said column does not need equilibration prior to binding of said nucleic acid.
[0032] One variation of this aspect further comprises in the elution solution an additive such that the pH of the elution solution is between about pH 9 and about pH 13. In one embodiment, the additive is arginine. In another embodiment the additive is guanidine present as its carbonate or bicarbonate salt. In yet another embodiment, the additive is potassium carbonate.
[0033] The salt concentration used in the packing of the column is similar to the salt concentration in the sample loading solution. Essentially the purification process in the improved protocol utilizes one salt strength from equilibration to loading and loading completion. The salt strength is increased only in the elution step.
[0034] Other features and advantages of the invention will be apparent from the following description of the preferred embodiments, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 shows pulse-field gel electrophoresis analysis of purified genomic DNA from human blood samples, using a method according to one embodiment of the invention.
[0036] FIG. 2 shows an agarose gel image of purified genomic DNA from human blood samples.
[0037] FIG. 3 shows comparison of restriction enzyme (EcoRI) digested and un-digested genomic DNA that was purified from human blood samples.
[0038] FIG. 4 shows real time PCR amplification results obtained from the genomic DNA samples from human blood, with very similar amplification profiles observed among the samples.
[0039] FIG. 5 shows pulse-field gel electrophoresis analysis of purified genomic DNA from rat liver samples, using a method according to one embodiment of the invention.
[0040] FIG. 6 shows real time PCR amplification results obtained from the genomic DNA samples from rat liver samples, with very similar amplification profiles observed among the samples.
[0041] FIG. 7 shows comparison of restriction enzyme (HindII) digested and un-digested genomic DNA that was purified from rat liver samples.
[0042] FIG. 8 shows pulse-field gel electrophoresis analysis of purified genomic DNA from cultured MRC5 cells samples, using a method according to one embodiment of the invention.
[0043] FIG. 9 shows comparison of restriction enzyme (EcoRI) digested and un-digested genomic DNA that was purified from MRC5 cells samples.
[0044] FIG. 10 shows an agarose gel picture of plasmid DNA isolated from E. coli using pre-equilibrated column according to one embodiment of the invention (Lanes 2 and 3) as compared to plasmid DNA purified using standard column (Lanes 4 and 5). Lane 1 is a 1 Kb DNA marker.
[0045] FIG. 11 shows an agarose gel picture of restriction digest of a 6.3 Kb plasmid DNA isolated using pre-equilibrated column according to one embodiment of the invention. Three duplicate samples are shown. The left lane shows a 1 Kb DNA marker.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] The following examples serve to illustrate the DNA purification processes according to embodiments of the present invention and are not intended to be limiting.
(A) Protocols Used in the Examples
[0047] (a) Isolation of Genomic DNA from Blood
[0048] Genomic DNA isolation from blood is done in 2 steps. The first step is the lysis of blood and the second step is purification of genomic DNA using ion-exchange column chromatography.
[0049] Lysis: This process involved 2 steps. First white blood cells are isolated and then the isolated white blood cells are lysed using lysis solution. The protocol used for the isolation of white blood cells and lysis of white blood cells is as follows. Five ml of blood is used as an example here. However, the protocol can be adjusted accordingly based on the amount of blood used.
1. Add 5 ml of whole blood to a 50 ml conical centrifuge tube. 2. Add 5 ml of pre-chilled Lysis1 solution and 15 ml of chilled water to the sample. Place the tubes in a rack and mix well by inverting the tubes 10-15 times. 3. Incubate at ambient temperature for 10 minutes. 4. Centrifuge at 1500×g for 10 minutes. 5. Discard the supernatant into a waste container containing diluted bleach solution (or follow appropriate safety precautions as recommended by the EHS) without disturbing pellet. 6. Add 1 ml of Lysis1 solution and 3 ml of water to the centrifuge tube and re-suspend the pellet by vortexing briefly. 7. Centrifuge at 5000×g for 10 minutes. 8. Discard the supernatant carefully without disturbing the white blood cell pellet. 9. Re-suspend the white blood cell pellet in 5 ml of Lysis2 solution by vortexing at highest speed for 30 sec to 1 min. 10. Add 50 μl of Proteinase K (20 mg/ml) (AG Scientific), vortex briefly and incubate at ambient temperature for 20 minutes. 11. Add 5 ml of Loading Solution to the centrifuge tube and mix well by swirling the tube and load this solution on the purification column.
Purification: The Purification Process also Includes a De-Salting Process (Steps 17-21).
[0000]
12. Remove the cap from the top of an ion-exchange purification column (approximately 1.5 ml of ion-exchange resin in a plastic tube, packed using an automated process on an instrument). Discard the solution by decanting. Cut the closed end of the column at the notch and place the columns in 50 ml centrifuge tubes using column adaptors.
13. Transfer the lysis solution obtained from step 11 above to the column and allow it to flow completely through the resin by gravity.
14. Apply 5 ml of Loading Solution to the column.
15. When all the Loading solution passes through the resin, place the columns in fresh 50 ml centrifuge tubes.
16. Add 2.5 ml of Elution solution to the column and collect the product in the eluate.
Desalting:
[0000]
17. Remove the cap of desalting column and discard the solution. Cut the closed end of the column at notch and place the column in a centrifuge tube using the adaptor.
18. Equilibrate the column by applying 25 mL of 1×TE buffer (10 mM Tris-HCl, pH 8.0, 1 mM EDTA). This can be accomplished by using LabMate PD-10 buffer reservoir (GE Healthcare) in one step.
19. Transfer the eluate (2.5 ml) from the purification step 16 to desalting column and allow it to flow by gravity.
20. When the solution has completely entered the gel bed, place the column in fresh 50 ml centrifuge tube.
21. Add 3.5 ml of 1×TE buffer to each column and collect the eluate containing genomic DNA. The desalted samples are now ready for quantitation and downstream applications.
(b) Isolation of Genomic DNA from Tissue Samples
[0071] The tissue sample is prepared by the following steps. It is critical to have a completely homogenized sample to obtain good yield of genomic DNA from the purification process.
1. Weigh approximately 100 mg of tissue by slicing into very fine pieces. 2. Wash the tissue with 1×PBS buffer. Add 1 ml of 1×PBS buffer, vortex and centrifuge at 1000 RPM for 1 min. Discard the washing and remove any traces of buffer left in the tube using a pipette. 3. Add 0.5 ml of 1×PBS buffer and homogenize the sample by handheld homogenizer.
[0075] Tissue samples so prepared are subjected to the following steps for the isolation of genomic DNA. Steps 4-7 are for sample lysis; steps 8-12 are for purification; and steps 13-17 are for de-salting.
4. Add 0.5 mL of Lysis solution to the homogenized sample (PBS and lysis solution in 1:1 ratio) and vortex at the highest possible speed for 20-30 sec. 5. Add 50 μl of proteinase K (20 mg/ml) solution, vortex briefly and incubate at 60° C. for 1-1.5 hours. 6. After the incubation period, cool the reaction tubes in an ice bath for 3 min. Add 20 μl of RNAse A solution (20 mg/ml) and incubate at 37° C. for 15 min. 7. Dilute the crude lysate with 4 ml of DNAse free water and 5 ml of Loading solution and centrifuge at 5000×g for 15 min to pellet particulates.
Purification:
[0000]
8. Remove the cap from the top of purification column. Discard the solution by decanting. Cut the closed end of the column at the notch and place the columns in 50 ml centrifuge tubes using column adaptors.
9. Transfer the lysis solution to the column and allow it to flow completely through the resin by gravity.
10. Apply 5 ml of Loading Solution to the column.
11. When all the Loading solution passes through the resin, place the columns in fresh 50 ml centrifuge tubes.
12. Add 2.5 ml of Elution solution to the column and collect the product in the eluate.
Desalting:
[0000]
13. Remove the cap of desalting column and discard the solution. Cut the closed end of the column at notch and place the column in a centrifuge tube using the adaptor.
14. Equilibrate the column by applying 25 mL of 1×TE buffer. This can be accomplished by using LabMate PD-10 buffer reservoir.
15. Transfer the eluate (2.5 ml) from the purification step 12 to desalting column and allow it to flow by gravity.
16. When the solution completely entered the gel bed, place the column in fresh 50 ml centrifuge tube.
17. Add 3.5 ml of 1×TE buffer to each column and collect the eluate containing genomic DNA. The desalted samples are now ready for quantitation and downstream applications.
(c) Isolation of Genomic DNA from Cell Cultures
[0090] Cell cultured cells are collected and lysed according to the protocol below. The purification and desalting is done as described in protocol (b) (“Isolation of genomic DNA from tissue samples”) above.
1. Wash between 1×10 7 and up to 2.0×10 7 cells with 1×PBS buffer (2×5 mL). Suspend the cells in 5 ml of 1×PBS buffer and centrifuge at 2000×g for 10 min. Decant the buffer carefully from the pellet and repeat the process once more. 2. Re-suspend the cell pellet completely in 1 ml of 1×TE Buffer by vortexing for 30 seconds to 1 minute. 3. Add 4.5 ml of Lysis Solution and vortex for 15-30 sec. 4. Add 50 μl of Proteinase K (20 mg/ml) and vortex briefly (2 sec). 5. Incubate at 60° C. for 1-2 hours. 6. Cool the tube in an ice bath for 2 min and add 20 ul of RNase A (20 mg/ml). 7. Incubate at 37° C. for 15 min.
(d) Quantitation of the Purified Genomic DNA Samples
[0098] Quantitation of the purified genomic DNA samples was achieved with a UV spectrophotometer, using 1×TE Buffer pH8.0 as the blank and 1 cm path length cuvettes. Readings of three samples were taken at A260, A280 and A320. Yield of DNA (μg)=A260×50 μg×Eluted sample volume (3.5 ml).
[0000] (e) Detailed Composition of Solutions Used in the Protocols
(i) Blood gDNA Protocol:
[0099] Lysis1 solution: 30 mM Tris-HCl, 10 mM Magnesium chloride, 2% Triton X 100 and 0.6 M sucrose.
[0100] Lysis2 solution: 20 mM Tris-HCl, 20 mM EDTA, 20 mM sodium chloride and 0.1% SDS.
[0101] Loading solution: 700 mM sodium chloride,50 mM Tris and 1 mM EDTA.
[0000] (ii) Tissue Protocol:
[0102] Lysis solution: 20 mM Tris-HCl, 20 mM EDTA, 100 mM sodium chloride and 1% SDS.
[0103] Loading solution: 700 mM sodium chloride, 50 mM Tris and 1 mM EDTA.
[0000] (iii) Cell Culture Protocol
[0104] Lysis Solution: 20 mM Tris-HCl, 20 mM EDTA, 100 mM sodium chloride and 1% SDS.
(B) Evaluation of Various Solutions for Genomic DNA Elution
[0105] In an effort to find an optimal elution solution for genomic DNA purification, high ionic salt strength solutions were tested for elution of genomic DNA from the bound anion exchanger.
[0106] As an example, ANX Sepharose fast flow (high sub) resins were used here. These resins are very stable over a wide pH range (3-13), with an average particle size of 90 μm (We have subsequently tested other anion exchange resins and found they work well too). The columns were pre-packed using 700 mM NaCl with 30% ethanol as an antimicrobial agent. This gives the pre-packed resin a salt solution similar in strength as the sample loading solution. This eliminates the need for column equilibration prior to loading of the sample in loading solution for binding of the nucleic acid.
[0107] The source cell used here was human blood and the blood protocol described in (A) (a) above was followed. We found that even when a salt concentration of 2 to 3M was used it did not significantly improve the recovery of genomic DNA from the ion-exchange columns. After elution all the samples were desalted using NAP-10 or NAP-25 columns (GE Healthcare) and the DNA was quantified using UV spectrophotometer. To identify a buffer or a solution which could provide better recovery, different combinations of salts were evaluated.
[0108] The following elution buffer/solution combinations were evaluated for genomic DNA elution in individual experiments.
1. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl 2. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+0.2 M sodium carbonate 3. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+0.2 M sodium perchlorate 4. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+0.2 M sodium bicarbonate 5. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+0.2 M magnesium chloride 6. 2M Sodium iodide 7. 2M Sodium perchlorate 8. 3M Ammonium acetate 9. 3M Ammonium acetate+0.2M sodium bicarbonate 10. 3M Ammonium acetate+0.2M sodium carbonate 11. 3M Ammonium acetate+0.2M sodium biborate 12. 3M Ammonium bicarbonate 13. 3M Sodium bicarbonate (not dissolved completely) 14. 3M Sodium carbonate 15. 3M Sodium phosphate (not dissolved completely, precipitates) 16. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+25 mM sodium hydroxide 17. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+50 mM sodium hydroxide 18. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+75 mM sodium hydroxide 19. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+100 mM sodium hydroxide 20. 50 mM Tris-HCl, pH 8.0, 1 mM EDTA, 200 mM NaCl+75 mM Lithium hydroxide 21. 2M Salt+500 mM L-Arginine 22. 1M sodium chloride+1M sodium carbonate
[0131] Representative results are shown below in Table 1. From the data it is clear that 2M salt solution itself elutes less than half of the genomic DNA that could be eluted with a combination of salt and sodium hydroxide, or salt and Arginine.
[0000]
TABLE 1
Representative elution solution combinations and genomic DNA yields
Eluant
Yield
Purity
2M Salt buffer
32 μg
1.80
2M Salt buffer + 50 mM NaOH
72 μg
1.87
2M Salt buffer + 75 mM NaOH
79 μg
1.89
2M Salt buffer + 75 mM LiOH
76 μg
1.92
2M Salt buffer + 100 mM NaOH
72 μg
1.88
2M Salt buffer 500 mM NaOH
74 μg
1.8
2M Salt + 1M Sodium carbonate
56 μg
1.76
[0132] Recovery of the remaining bound material can be accomplished with a combination of high salt concentration and elevated pH using sodium hydroxide. However, sodium hydroxide is not only caustic, but may also lead to irreversible denaturation of nucleic acids and degradation over time.
[0133] It has also been observed that the cation used as a counter ion, as well as the pH of elution has an effect on recovery of HMW nucleic acids, the use of strongly alkaline (such as with sodium hydroxide) may be detrimental to recovery because of the co-elution of contaminants and detrimental effects on product stability.
[0134] Since arginine, which has a carboxylic acid group and also a guanidinium group, was showing a dramatic effect in the elution process, we evaluated other amino acids and guanidinium salts and also the combination of amino acid and guanidinium salt to identify whether it is the carboxylic acid group or guanidinium group that contributes to the improved recovery. The results are summarized in Table 2.
[0000]
TABLE 2
Evaluation of various amino acids and guanidinium salts for their
effects in improving genomic DNA elution
Eluant
Yield
Purity
3M Salt buffer
37 μg
1.78
2M Salt buffer + 1M Sodium carbonate
62 μg
1.73
2M Salt buffer + 0.5M Arginine
82 μg
1.80
2M Salt buffer + 0.1M Arginine
46 μg
1.78
2M Salt buffer + 0.5M Aspartic acid
39 μg
1.63
2M Salt buffer + 0.5M Aspartic acid + 0.5M
41 μg
1.57
Guanidine HCl
2M Salt buffer + 0.5M Guanidine
39 μg
1.64
2M Salt buffer 50 mM NaOH
76 μg
1.81
[0135] We noticed that the elution solutions which improve genomic DNA recovery and elution have a common feature, that is an elevated pH of around 10.5 to 11.6. It appears that improved elution of nucleic acids employing guanidinium is facilitated by the presence in the elution solution of carbonate (or bicarbonate). Based on this observation further experiments were performed to test the effect of elevated pH. We compared 2M sodium chloride with sodium carbonate or 2M sodium chloride with Tris base or arginine. The results obtained are given in Table 3.
[0000]
TABLE 3
Evaluation of various solutions with similar pH for their effects on
improving genomic DNA elution
Eluant
Yield
Purity
2M Salt buffer
64 μg
1.81
2M Salt buffer + 0.25M Arginine
110 μg
1.81
2M Salt buffer + 0.5M Arginine
118 μg
1.82
2M Salt buffer + 0.5M Sodium carbonate
93 μg
1.79
2M Salt buffer + 1M Sodium carbonate
93 μg
1.74
2M Salt buffer + 0.5M Tris base
86 μg
1.77
2M Salt buffer + 1M Tris base
85 μg
1.77
2M Salt buffer + 50 mM NaOH
118 μg
1.82
2M Salt buffer + 0.5M Arginine
101 μg
1.82
2M Salt buffer + 0.5M Arginine
97 μg
1.82
[0136] Based on the evaluation of several different solutions pH appears to play a critical role in the recovery of genomic DNA in addition to the salt strength. Combination of 1 to 2M sodium chloride, with 0.25M to 0.5M arginine, 0.5-1 M sodium carbonate and 0.5 to 1 M Tris can be used for improved elution.
[0137] Since elevated pH appeared to be the factor that helped recover higher amount of genomic DNA from the ion-exchange resins, several more combinations of salt with guanidine derivatives were evaluated as an elution solution, all of which provided higher pH for the elution solution.
1. 2M NaCl+0.2 M L-Arginine 2. 2M NaCl+0.5M Guanidine carbonate 3. 2M NaCl+0.5M Guanidine carbonate+0.5M Glycine 4. 2M NaCl+0.5M Guanidine carbonate+0.5M L-glutamic acid 5. 2M NaCl+0.5M Guanidine propionic acid
[0143] The results clearly demonstrate that addition of arginine, guanidine carbonate or other guanidine derivatives such guanidine propionic acid to 1M to 2M sodium chloride solution has similar effects on the elution of genomic DNA from the ion-exchange resins (Table 4).
[0000]
TABLE 4
Evaluation of additional solutions with similar pH for their effects in
improving genomic DNA elution
Eluant
Yield
Purity
2M Salt buffer + 0.25M Arginine
121 μg
1.8
2M Salt buffer + 0.5M Guanidine carbonate
128 μg
1.8
2M Salt buffer + 0.5M Guanidine carbonate + 0.5M
130 μg
1.81
Glycine
2M Salt buffer + 0.5M Guanidine carbonate + 0.5M
125 μg
1.79
L-Glutamic acid
2M Salt buffer + 0.5M Guanidine propionic acid
126 μg
1.77
(C) Comparison of L-Arginie, Guanidine Carbonate and Potassium Carbonate in Elution Solution
[0144] Since a combination of sodium chloride and sodium carbonate did provide some improvement in the recovery, a solution of potassium carbonate in combination with sodium chloride is evaluated, in comparison with guanidine carbonate and L-arginine. The pH of a solution of sodium chloride and sodium carbonate is not optimal for complete recovery of the nucleic acids from the ion-exchange resin. Since potassium carbonate will give higher pH solution, it is expected to give higher recovery of the nucleic acids from ion-exchange resins. Indeed a combination of sodium chloride and potassium carbonate did give a solution with higher pH and the elution profile compared well with a solution containing guanidine carbonate or arginine. The experimental details are similar to those of section (B) supra. Again, human blood was used as the genomic DNA source and the blood protocol described in (A) (a) was followed. The results are shown in Table 5.
[0000]
TABLE 5
Evaluation of the effect of L-Arginie, Guanidine Carbonate and Potassium
Carbonate in elution solutions
Eluant
Yield
Purity
1M NaCl + 0.5M L-Arginine
146
1.77
1M NaCl + 0.5M Guanidine carbonate
139
1.77
1M NaCl + 0.5M Potassium carbonate
144
1.79
[0145] From the data in Table 5, it is clear that a sodium chloride solution containing potassium carbonate is equally effective in genomic DNA elution, when compared with a solution containing either guanidine carbonate or L-arginine, from ion-exchange resins.
[0146] Based on the systematic evaluation of various additives, pH appears to play a critical role in the recovery of nucleic acid in addition to the salt strength. Combination of 1 to 2 M sodium chloride, with 0.25 to 0.5M arginine, 0.5M potassium carbonate or 0.5M guanidine carbonate can be used for improved elution. 0.5 to 1 M sodium carbonate or 0.5M to 1 M Tris base can also be used to increase the elution as well.
(D) Genomic DNA Purification from Blood
[0147] An 8 ml sample of human blood was lysed using the procedure described in the protocol section. The crude lysate was diluted with loading solution and loaded on the ion-exchange purification column. After all the solution passed through the resin an additional 5 ml of loading solution was added onto the column. When there was no more solution on the top of the resin, 2.5 ml of elution solution (1M sodium chloride+0.5 M potassium carbonate) was added and the eluate containing genomic DNA was collected in a collection tube. The product obtained was desalted using NAP-25 column. The size of the genomic DNA isolated was determined by Pulse Field Gel Electrophoresis ( FIG. 1 ). The purity of the product was assessed by UV spectrophotometry and by gel analysis ( FIG. 2 ). The genomic DNA obtained by this method was also evaluated in downstream applications such as restriction digestion ( FIG. 3 ), Multiplex PCR and Real Time PCR ( FIG. 4 ).
[0148] By Pulse Field Gel Electrophoresis, it is clear that the purified genomic DNA from Blood are of large size ( FIG. 1 ). The purity of the sample was examined by an agarose gel analysis ( FIG. 2 ). It demonstrates that the genomic DNA isolated is pure and without RNA contamination.
[0149] The quality of the purified genomic DNA was assessed by several methods.
[0150] The DNA was subjected to restriction enzyme digest using EcoRI. Purified genomic DNA (250 ug) was digested with 40 units of the enzyme. The digested sample was analyzed on an agarose gel side-by-side with un-digested sample DNA. The gel image shows that all the genomic DNA was completely digested ( FIG. 3 , Lanes 2, 4, 6 represent the purified, un-digested genomic DNA, while Lanes 1, 3, 5 are samples digested with the enzyme).
[0151] The quality of the genomic DNA samples was indirectly measured by the efficiency in a multiplex PCR reaction. A long range multiplex PCR for the P450 genes were used for this test (CodeLink P450 protocol, GE Healthcare). Three amplicons from genes CYP2D6, CYP3A4, and CYP3A5 were amplified in a single reaction. The size in amplicons ranges from 335 bp to 2600 bp. The size and yield of the PCR products were determined via the Agilent Biolanalyzer 2100 and DNA 7500 kit. The multiplex PCR reactions worked well for all the samples tested (data not shown).
[0152] The quality of the genomic DNA samples was also tested by real time PCR assays. Real time PCR experiments were done using Applied Biosystems 7900HT Fast Real Time PCR System. All the samples tested show very similar amplication profiles ( FIG. 4 ).
[0153] The same purification process has been successfully applied to blood samples from other animals as well. High quality genomic DNA was isolated from different animals such as rat, Guinea pig, horse, chicken and sheep.
(E) Isolation of Genomic DNA from Tissue Samples
[0154] Two hundred milligrams of rat liver tissue was homogenized and lysed as described in the protocol section. The crude lysate was diluted with loading solution and centrifuged to pellet any particulates. The clear lyasate was loaded on the ion-exchange purification column. After all the solution passed through the resin, 5 ml of loading solution was added to the column. When there was no more solution left on the top of the resin, 2.5 ml of elution solution (1M sodium chloride+0.5 M potassium carbonate) was added to the column and the product was collected in the eluate. The genomic DNA thus obtained was desalted using NAP-25 column. The purity of the product was assessed by UV spectrophotometry and by gel analysis. Multiple samples were processed to access the consistency of the protocol. The size of the genomic DNA isolated was determined by Pulse Field Gel Electrophoresis ( FIG. 5 ). The genomic DNA obtained by this method was also evaluated in downstream applications such as real time PCR ( FIG. 6 ), and restriction digestion ( FIG. 7 ).
[0155] By Pulse Field Gel Electrophoresis, it is clear that all the purified genomic DNA samples from rat liver tissue are of large size ( FIG. 5 ). The purity of the sample was examined by an agarose gel analysis. It demonstrated that the genomic DNA isolated is pure and without RNA contamination (data not shown).
[0156] The quality of the purified genomic DNA was assessed by several methods.
[0157] The quality of the genomic DNA samples was tested by real time PCR assays. Real time PCR experiments were performed using Applied Biosystems 7900HT Fast Real Time PCR System. All the samples tested show very similar amplication profiles ( FIG. 6 ).
[0158] The DNA was subjected to restriction enzyme digest using HindIII. Purified genomic DNA (250 ug) was digested with 40 units of the enzyme. The digested sample was analyzed on an agarose gel side-by-side with un-digested sample DNA. The gel image shows that all the genomic DNA was completely digested ( FIG. 7 , Lanes 2, 4, 6, 8 represent the purified, un-digested genomic DNA, while Lanes 1, 3, 5, 7 are samples digested with the enzyme).
(F) Isolation of Genomic DNA from Cell Cultures
[0159] Approximately 2×10 7 MRC5 cells were lysed using the procedure described in the protocols section. The crude lysate was diluted with loading solution and transferred to the ion-exchange purification column. After all the solution passed through the resin, 5 ml of loading solution was added to the column. When there was no more solution left on the top of the resin, 2.5 ml of elution solution was added to the column and the product was collected in the eluate. The genomic DNA thus obtained was desalted using NAP-25 column. The purity of the product was assessed by UV spectrophotometry and by gel analysis. The size of the genomic DNA isolated was determined by Pulse-Field Gel Electrophoresis. The genomic DNA obtained by this method was also evaluated in downstream applications such as real time PCR and restriction digestion.
[0160] By Pulse Field Gel Electrophoresis, it is clear that all the purified genomic DNA samples from MRC5 cells are of large size (100 Kb; FIG. 8 ). The purity of the sample was examined by an agarose gel analysis. It demonstrated that the genomic DNA isolated is pure and without RNA contamination (data not shown).
[0161] The quality of the purified genomic DNA was assessed by restriction digest. The DNA was subjected to restriction enzyme digest using EcoRI. Purified genomic DNA (250 ug) was digested with 40 units of the enzyme. The digested sample was analyzed on an agarose gel side-by-side with un-digested sample DNA. The gel image shows that all the genomic DNA was completely digested ( FIG. 9 , Lanes 2, 4, 6, 8, 10, 12 represent the purified, un-digested genomic DNA, while Lanes 1, 3, 5, 7, 9, 11 are samples digested with the enzyme).
(G) Isolation of Plasmid DNA from E. Coli
[0162] The purification medium (anion exchanger) is provided in a pre-equilibrated format. The excellent flow characteristics of the media facilitate gravity-flow, which in combination with pre-equilibration reduces hands-on and total process time. The solution used for pre-equilibration has been optimized to prevent the majority of impurities from binding to the medium, leading to higher purity and yield of plasmid DNA.
[0163] The protocol is optimized for the purification of up to 250 μg of high-copy and low-copy number plasmid from E. coli. When working with low-copy number plasmids (10-50 copies per cell) the amount of plasmid in the lysate may be limiting and larger culture volumes will be required. The following shows a step by step protocol:
1. Harvest 25 to 50 ml (high-copy plasmid) or 150 ml (low-copy plasmid) overnight LB culture at 5000 g for 15 min at 4° C. 2. Resuspend cell pellet in 6 ml Resuspension buffer 1 (100 mM Tris-Cl pH7.5; 10 mM EDTA; 0.4 mg/ml RNase I) 3. Add 6 ml Lysis buffer 2 (200 mM NaOH; 1% SDS), invert to mix 6 times, incubate for 5 min. Note that if Lysis buffer 2 has SDS precipitation, it should be dissolved at 37° C. prior to step 3. 4. Add 6 ml chilled Neutralization buffer 3 (3M potassium Acetate pH 5.5), invert to mix 6 times, incubate on ice for 15 min. 5. Centrifuge at 20000 g for 30 min at 4° C. During centrifugation, prepare purification column and drain packing solution. 6. Carefully remove supernatant and apply to purification column; allow complete gravity flow. 7. Apply 10 ml Wash buffer (50 mM Tris-Cl pH8; 1 mM EDTA; 650 mM NaCl) to column; allow complete gravity flow. 8. Repeat step 7. 9. Apply 4 ml Elution buffer (50 mM Tris-Cl pH8; 1 mM EDTA; 1.2 M NaCl) to column and collect eluate by gravity-flow into suitable centrifuge tube. 10. Add 4 ml isopropanol to eluate, mix by inversion. Centrifuge at 15000 g for 30 min at 4° C. Carefully remove supernatant. 11. Wash pellet with 5 ml 70% ethanol. Centrifuge at 15000 g for 10 min. Carefully remove supernatant. 12. Air dry pellet and dissolve DNA in 1 ml TE buffer.
[0176] Purified plasmid DNA concentration should be determined by UV spectrophotometry (A 260 ) and through comparison with a known standard by agarose gel electrophoresis and subsequent densitometric analysis. If available, the UV spectrophotometric ratios A 260 :A 280 and A 260 :A 230 provide a limited indication of purity as measures of protein, RNA and salt contamination. Endotoxin can be determined by a number of methods, such as the QCL systems from Cambrex Corp.
[0177] Agarose gel electrophoresis and subsequent densitometric analysis can be used to assess the percentage of supercoiled plasmid DNA relative to genomic DNA and denatured supercoiled and nicked (linear and open circular) plasmid.
[0178] FIG. 10 shows an agarose gel of plasmid isolated using this protocol. As an example, a 6.3 Kb high copy number plasmid from E. coli TOP10 cell was isolated according to this protocol (Lanes 2 and 3). The anion-exchange resin was provided in a pre-packed column format, pre-equilibrated with a salt solution (0.7 M NaCl) in 30% ethanol. Prior to loading the plasmid containing lysate, simply remove the cap, pour off the packing fluid and cut off the recessed porton of the column tip. The remaining packing solution was allowed to drain from the resin by gravity-flow prior to addition of clarified lysate.
[0179] Lanes 4 and 5 shows the same plasmid isolated using standard column. Here, the columns were not pre-equilibrated, but were equilibrated prior to loading of the lysate. It can be seen that the isolated plasmid DNA are of similar quality and quantity from both pre-equilibrated columns and columns equilibrated immediately prior to sample loading.
[0180] We further tested the quality of the DNA by restriction digest. The sample plasmid DNA purified using the pre-equilibrated column was easily digested ( FIG. 11 ). Further analyses were performed of these samples, including sequencing, transfection assay and endotoxin assay (Cambrex QXL-LAL assay). The results shown that the sample DNA are well suited for both sequencing analyses and transfection assay. Further, endotoxin levels in these samples are low. (Data not shown).
[0181] All patents, patent publications, and other published references mentioned herein are hereby incorporated by reference in their entireties as if each had been individually and specifically incorporated by reference herein. While preferred illustrative embodiments of the present invention are described, one skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration only and not by way of limitation. The present invention is limited only by the claims that follow.
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The invention provides an improved method for the purification of nucleic acid molecules, which method comprises generating a cellular lysate containing the nucleic acid; contacting the lysate with an anion exchanger bound to a solid support matrix under conditions such that the anion exchanger binds the nucleic acid; followed by eluting the nucleic acid from the anion exchanger with an aqueous mobile phase comprising an elution solution; and desalting the eluted nucleic acid such that it is suitable for downstream applications. The improvement of the method includes providing the anion exchanger in a packed column, wherein the column is packed using a salt solution containing an antimicrobial agent. In addition, the salt solution has a salt concentration similar to that of the lysate, such that the column does not need equilibration prior to sample loading.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Korean Patent Application No. 2012-0047484, filed on May 4, 2012, and all the benefits accruing therefrom under 35 U.S.C. §119, the contents of which in its entirety are herein incorporated by reference.
BACKGROUND
[0002] 1. Field
[0003] The present disclosure relates to a method for preparing monolithic silica aerogel. More particularly, the present disclosure relates to a method for preparing monolithic silica aerogel, including hydrophobitizing monolithic wet silica gel by dipping it into an alkylsilane solution.
[0004] 2. Description of the Related Art
[0005] Silica aerogel, which is given many attentions recently as an ultralight advanced material, is a material having unlimited applicability to industrial fields of energy and environment by virtue of its physical properties, such as high porosity, large surface area, low density, transparency and low heat conductivity. Therefore, porous silica aerogel is applicable to industrial fields related to heat insulating materials, noise-protecting materials, storage materials, ultralight materials for cars and space crafts, electrochemical materials, catalysts of electronic materials, catalyst carriers, or the like. Thus, it is expected that silica aerogel is useful as a key material in various industrial fields.
[0006] Particularly, use of silica aerogel as a heat insulating material is one of the most commercially practical uses of silica aerogel. Transparent silica aerogel may be used as a heat insulating window, while opaque silica aerogel may be used effectively as a heat insulating material for various low-temperature or high-temperature heat insulating materials. Transparent aerogel allows transmission of solar light and effective shielding of heat, and thus may provide an energy-saving window system when used for a skylight. Currently, skylight ceiling window systems having a double pane window in which translucent silica aerogel particles are filled have been commercialized and distributed for practical use. However, such systems have a limitation in transparency and are problematic in that the aerogel particles are driven downwardly due to the gravity during long-time use. Meanwhile, monolithic transparent aerogel may be filled into double pane windows to be used as heat insulating windows. However, except some specialized uses, it is difficult to commercialize such windows in terms of cost efficiency, because silica aerogels are required to be formed into monoliths having the same size as the windows.
[0007] Monolithic hydrophilic silica aerogel shows transparency and high heat insulating property, but is sensitive to moisture in the air. Thus, such silica aerogel causes cracking on the surface and inner part of the aerogel when exposed to the air for a long time, thereby making it difficult to maintain its originally high heat insulating property. Therefore, it is required to provide a method for preventing moisture absorption in the atmosphere for the purpose of commercialization of such aerogel. For this, many studies have been conducted and many methods have been suggested to provide hydrophobic aerogel.
[0008] Particularly, the following methods for preparing hydrophobic silica aerogel have been suggested. First, Korean Patent Laid-Open publication No. 2011-0125773 discloses a method for preparing hydrophobic silica aerogel, which includes preparing a sol solution by using a tetraethoxysilane precursor and an alcohol solvent, and introducing hexamethyldisilazane during the synthesis of gel. This is a general method for imparting hydrophobic property to silica aerogel. However, the method results in a rapid increase in shrinkage of silica aerogel and degradation of heat conductivity.
[0009] Next, U.S. Pat. No. 5,888,425 discloses a method for preparing hydrophobic silica aerogel, which includes preparing silicatic lyogel, subjecting the lyogel to a solvent exchange with another organic solvent, reacting the gel with a chlorine-free silylating agent to hydrophobitize it via alkyl radical reaction, and subjecting the resultant gel to subcritical drying. WO 98/02336 discloses a method for preparing hydrophobic silica aerogel, which includes reacting water glass with acid to form lyogel, subjecting the lyogel to a solvent exchange with another organic solvent, silylating the gel by using disiloxane, and subjecting the resultant gel to drying. As such, the above methods essentially require a solvent exchange with an organic solvent and use of an excessive amount of silylating agent for hydrophobitization, and thus have poor cost efficiency.
[0010] In addition, the process of hydrophobitization in the methods for preparing hydrophobic silica aerogel according to the related art has a difficulty in application to monolithic aerogel, is complicated due to the use of mixed solution after pH adjustment, and shows poor cost efficiency due to the continuous use of expensive butanol and alkylsilylating agent from a reflux process to a hydrophobitization operation. Further, the drying operation at high temperature after the hydrophobitization causes problems of high shrinkage and degradation of heat conductivity.
[0011] To enhance the applicability of hydrophobic monolithic silica aerogel, it is important to provide aerogel to which hydrophobic property is imparted while minimizing deformation of aerogel. According to the related art, silica aerogel is hydrophobitized by using an excessive amount of silylating agent. Thus, the related art is not cost efficient and is problematic in that it causes an increase in shrinkage and degradation of heat insulating property during the hydrophobitization. Under these circumstances, there is a need for providing hydrophobic monolithic silica aerogel having excellent heat insulating property by imparting hydrophobic property thereto in a more cost-efficient manner.
REFERENCES OF THE RELATED ART
Patent Document
[0000]
Korean Laid-Open Patent Publication No. 2011-0125773
U.S. Pat. No. 5,888,425
WO 98/02336
SUMMARY
[0015] The present disclosure is directed to providing a method for preparing hydrophobic monolithic silica aerogel having excellent hydrophobic property and heat insulating property in a simple and cost efficient manner, which comprises carrying out hydrophobitization through a dipping process by dipping monolithic wet silica gel obtained by using an alkoxide precursor into an alkylsilane solution as a dipping solution. The present disclosure is also directed to providing a method for controlling a degree of hydrophobitization of hydrophobic monolithic silica aerogel.
[0016] In one aspect, there is provided a method for preparing hydrophobic monolithic silica aerogel, comprising: dipping monolithic wet silica gel obtained by using an alkoxide precursor into an alkylsilane solution as a dipping solution to perform hydrophobitization of the surface and inner part of the monolithic wet silica gel by a dipping process.
[0017] According to an embodiment, the method may comprise: preparing monolithic wet silica gel by using an alkoxide precursor; hydrophobitizing the monolithic wet silica gel by dipping the wet gel into an alkylsilane solution through a dipping process; and carrying out supercritical drying of the hydrophobitized monolithic wet silica gel.
[0018] According to an embodiment, the alkylsilane may be at least one selected from the group consisting of methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, phenyltrimethoxysilane, hexamethyldisilane, methoxytrimethylsilane, triethylethoxysilane, trimethylchlorosilane, vinyltriethoxysilane and dimethyldiethoxysilane.
[0019] According to an embodiment, the solvent used for the alkylsilane solution may be selected from the group consisting of methanol, dimethylformamide and a mixture thereof.
[0020] According to an embodiment, the alkylsilane solution may have a concentration of 3-30 vol %.
[0021] According to an embodiment, the alkylsilane solution may be maintained at a temperature of 25-80° C.
[0022] According to an embodiment, the monolithic wet silica gel may be dipped in the alkylsilane solution for 6-48 hours.
[0023] The method for preparing hydrophobic monolithic silica aerogel disclosed herein is economical by virtue of the use of a small amount of alkylsilane compound and imparts hydrophobic property to monolithic silica aerogel in a cost efficient and time efficient manner. In addition, the method disclosed herein reduces shrinkage of hydrophobic monolithic silica aerogel, enables production of hydrophobic monolithic silica aerogel in a translucent form, and allows the hydrophobic monolithic silica aerogel to maintain low heat conductivity similar to the heat conductivity of hydrophilic silica aerogel. Further, the hydrophobic monolithic silica aerogel may be used directly as a heat insulating panel by virtue of excellent hydrophobic property and heat insulating property.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a flow chart of the method for preparing hydrophobic monolithic silica aerogel according to an embodiment; and
[0025] FIG. 2 is a photograph illustrating a method for measuring water contact angles of hydrophobic monolithic silica aerogel according to an embodiment.
DETAILED DESCRIPTION
[0026] Exemplary embodiments now will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown.
[0027] Provided is a method for preparing hydrophobic monolithic silica aerogel, comprising dipping monolithic wet silica gel obtained by using an alkoxide precursor into an alkylsilane solution as a dipping solution to perform hydrophobitization of the surface and inner part of the monolith wet silica gel.
[0028] More particularly, the method disclosed herein comprises: preparing monolithic wet silica gel by using an alkoxide precursor; dipping the monolithic wet silica gel into an alkylsilane solution to perform hydrophobitization of the monolithic wet silica gel by a dipping process; and carrying out supercritical drying of the hydrophobitized monolithic wet silica gel.
[0029] Hereinafter, the method for preparing hydrophobic monolithic silica aerogel will be explained in more detail.
[0030] First, monolithic wet silica gel is prepared by using an alkoxide precursor.
[0031] The alkoxide precursor may be at least one selected from a tetramethoxysilane precursor and tetraethoxysilane precursor, but is not limited thereto.
[0032] Herein, the monolithic wet silica gel may be prepared by any method known to those skilled in the art. For example, it may be prepared by a known sol-gel process, but is not limited thereto. Particularly, to provide monolithic wet silica gel, a gelation catalyst is introduced to a silica sol solution, followed by mixing for a predetermined time, and introducing the solution to a mold with a predetermined size while maintaining its solution state, thereby carrying out gelation. The sol-gel process is described in many references including Sol-Gel Science, C. J. Brinker and G. W. Scherer, New York, Academic press, 1990.
[0033] The wet silica gel has a surface with a Si—OH structure.
[0034] Then, the monolithic wet silica gel is dipped into an alkylsilane solution so that the wet gel is hydrophobitized through a dipping process.
[0035] Although there is no particular limitation, the alkylsilane may be at least one selected from the group consisting of methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, phenyltrimethoxysilane, hexamethyldisilane, methoxytrimethylsilane, triethylethoxysilane, trimethylchlorosilane, vinyltriethoxysilane and dimethyldiethoxysilane. Particularly, the alkylsilane may be at least one selected from the group consisting of methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane and phenyltrimethoxysilane.
[0036] The solvent for the alkylsilane solution is not particularly limited as long as it is an organic solvent, and may be selected from the group consisting of methanol, dimethylformamide and a mixture (methanol/dimethylformamide) thereof.
[0037] In addition, the alkylsilane solution may have a concentration of 3-30 vol %, particularly 5-20 vol %, and more particularly 15-20 vol %. When the alkylsilane solution has a concentration less than 3 vol %, it shows hydrophilic property. The alkylsilane solution shows a continuous increase in hydrophobicity up to 30 vol %. However, when the concentration exceeds 30 vol %, there is no significant effect upon improvement in hydrophobicity despite the use of such an expensive alkylsilane solution.
[0038] The alkylsilane solution may be maintained at a temperature of 25-80° C., particularly 25-70° C., and more particularly 50-70° C. When the temperature is lower than 25° C., it is not possible to realize hydrophobicity within a predetermined time. On the other hand, a temperature higher than 80° C. is not applicable to a dipping process, since it is similar to the boiling point of the dipping solution.
[0039] The alkylsilane may be dipped in the alkylsilane solution for a dipping time of 6-48 hours, particularly 24-48 hours. When the dipping time is less than 6 hours, it is not possible to realize hydrophobicity. On the other hand, when the dipping time is more than 48 hours, it is not possible to obtain any significant improvement in hydrophobicity with time.
[0040] Dipping of the monolithic wet silica gel into the alkylsilane solution may be carried out in a batchwise or continuous mode, but is not limited thereto.
[0041] When the monolithic wet silica gel is dipped and hydrophobitized in the alkylsilane solution in which an alkylsilane compound with a structure of Rx—Si—(OR) (4-x) (wherein R is an alkyl group) is dissolved, Si—OH groups present on the surface of the wet gel and —OR groups of the alkylsilane compound are condensed to form Si—O—Si(R x (OR) (3-x) ). Finally, Si—O—Si—R structure is formed on the surface of the monolithic wet silica gel. Therefore, —R groups are substituted on the silica surface, thereby realizing hydrophobic property. In this manner, the surface and inner part of the wet silica gel are hydrophobitized.
[0042] In the method, the process of preparing wet silica gel is separated from the process of hydrophobitizing using a dipping process. When both processes are carried out simultaneously, it is not possible to obtain a desired effect as demonstrated by the following Test Example 1.
[0043] Then, the hydrophobitized monolithic wet silica gel is subjected to supercritical drying to obtain finished hydrophobic monolithic silica aerogel.
[0044] The obtained hydrophobic monolithic silica aerogel may be used in the form of hydrophobic silica aerogel powder after pulverization.
[0045] In brief, the hydrophobic monolithic silica aerogel disclosed herein is obtained by imparting hydrophobic property to monolithic wet silica gel by dipping it into an alkylsilane solution diluted with an organic solvent. FIG. 1 is a schematic view illustrating the method disclosed herein.
[0046] In addition, the method disclosed herein allows partial or total hydrophobitization of the surface of monolithic silica aerogel by using a dipping process. Thus, it is possible to control a degree of hydrophobitization of monolithic silica aerogel.
[0047] The hydrophobic monolithic silica aerogel obtained by the method disclosed herein is cost efficient by virtue of a simple and economical process, and has excellent heat insulating property and hydrophobic property so that it may be used in various industrial fields, including heat insulating panels.
[0048] The examples and experiments will now be described. The following examples and experiments are for illustrative purposes only and not intended to limit the scope of the present disclosure.
Example 1
Hydrophobic Monolithic Silica Aerogel Using Dipping Process
[0049] Tetraethoxysilane precursor is diluted with methanol and dimethylformamide as solvents in a molar ratio of 1:6:4, and then 4 moles of water and 0.005 moles of aqueous ammonia are introduced thereto to carry out hydrolysis for 2 hours. Then, gelation is carried out by using ammonium fluoride catalyst to obtain monolithic wet gel, which, in turn, is aged for 24 hours. In a separate container, methyltrimethoxysilane is diluted with methanol to provide about 3 L of solution with a concentration of 10 wt %. Then, the wet gel is introduced to the solution to perform surface hydrophobitization while maintaining room temperature (25° C.) for 24 hours. The treated wet gel is subjected to carbon dioxide substitution and supercritical drying to obtain finished monolithic silica aerogel.
Comparative Example 1
Hydrophilic Monolithic Silica Aerogel
[0050] Example 1 is repeated except that the hydrophobitization using a dipping process is omitted. As a result, hydrophilic monolithic silica aerogel is obtained.
[0051] The hydrophilic monolithic silica aerogel is determined for shrinkage, water contact angle and heat conductivity. The results are shown in the following Table 1.
Comparative Example 2
Hydrophobic Monolithic Silica Aerogel Using Co-Precursor Process
[0052] Example 1 is repeated, except that a co-precursor process in which 0.6 moles of methyltrimethoxysilane is introduced during the preparation of wet gel so that the preparation of wet silica gel is carried out simultaneously with the hydrophobitization using a dipping process. As a result, hydrophobic monolithic silica aerogel is obtained.
Test Example 1
[0053] Each monolithic silica aerogel obtained according to Example 1 and Comparative Examples 1 and 2 is determined for shrinkage, and water contact angle of each aerogel is also measured to determine hydrophobic property. In addition, to measure the heat conductivity of each monolithic silica aerogel according to Example 1 and Comparative Examples 1 and 2, a heat flow meter is used. Herein, a heat flow meter (Model: HFM 436/3/1 Lambda) available from Netzsch Co. is used to measure heat conductivity. The instrument is based on standard methods defined by ISO 8301 and ASTM C518, and is operated at 0.005-0.5 W/m·K. The instrument is used to measure the heat conductivity of the hydrophobic monolithic silica aerogel obtained as described above.
[0054] The results are shown in Table 1. Table 1 shows the shrinkage, water contact angle and heat conductivity of each monolithic silica aerogel according to Example 1 and Comparative Examples 1 and 2.
[0000]
TABLE 1
Shrinkage
Water contact
Heat conductivity
(%)
angle (°)
(W/m · K)
Ex. 1
24.2
121
0.0131
Comp. Ex. 1
50.1
0
0.0137
Comp. Ex. 2
54.6
99
0.0171
[0055] As can be seen from Table 1, the monolithic silica aerogel (Example 1) hydrophobitized by using a dipping process has low shrinkage, large water contact angle and low heat conductivity.
Example 2
Hydrophobic Monolithic Silica Aerogel with Different Dipping Solution Concentration
[0056] Monolithic silica aerogel is hydrophobitized by using a dipping process in the same manner as described in Example 1, except that four methyltrimethoxysilane solutions having different concentrations (5, 10, 15, 20 wt %) are used for the dipping process.
[0057] Each hydrophobic monolithic silica aerogel obtained in this Example is determined for shrinkage, water contact angle and heat conductivity. The following Table 2 shows the shrinkage, water contact angle and heat conductivity of monolithic silica aerogel hydrophobitized with dipping solutions having a concentration of 5, 10, 15 and 20 wt %.
[0000]
TABLE 2
Dipping solution
Shrinkage
Water contact
Heat conductivity
concentration (%)
(%)
angle (°)
(W/m · K)
5
24.7
108
0.0126
10
24.2
121
0.0128
15
24.0
130
0.0131
20
24.2
136
0.0125
[0058] As shown in Table 2, the monolithic silica aerogel hydrophobitized with a varied concentration of dipping solution maintains low shrinkage and heat conductivity, and shows an increase in water contact angle as the concentration of dipping solution increases.
Example 3
[0059] Monolithic silica aerogel is hydrophobitized by using a dipping process in the same manner as described in Example 1, except that temperature of a 10 wt % methyltrimethoxysilane/methanol dipping solution is varied to 25° C. and 70° C. and dipping time is varied to 6 hours and 24 hours.
[0060] Each hydrophobic monolithic silica aerogel obtained in this Example is determined for shrinkage, water contact angle and heat conductivity. The following Table 3 shows the shrinkage, water contact angle and heat conductivity of monolithic silica aerogel hydrophobitized by using a dipping solution with a temperature of 25° C. and 70° C. for a dipping time of 6 hours and 24 hours.
[0000]
TABLE 3
Heat
Dipping solution
Dipping
Shrinkage
Water contact
conductivity
temperature(° C.)
time (h)
(%)
angle (°)
(W/m · K)
RT(25)
24
24.2
121
0.0128
RT(25)
6
24.4
0
0.0128
70
6
18.7
123
0.0125
70
24
20.8
134
0.0133
[0061] As can be seen from Table 3, the monolithic silica aerogel hydrophobitized with a varied temperature of dipping solution shows a drop in shrinkage and an increase in water contact angle as the temperature increases to 70° C., and maintains low heat conductivity. In addition, when the dipping process is carried out at a temperature of 70° C. for 6 hours, the silica aerogel has decreased shrinkage and increased water contact angle as compared to the silica aerogel hydrophobitized at room temperature for 24 hours. Therefore, it can be seen that monolithic silica aerogel is hydrophobitized in a shorter time at a higher temperature of dipping solution.
Example 4
[0062] Monolithic silica aerogel is hydrophobitized by using a dipping process in the same manner as described in Example 1, except that 10 wt % methyltrimethoxysilane/methanol dipping solution is used for a dipping time of 6-48 hours (6, 12, 24, 48 hours).
[0063] Each hydrophobic monolithic silica aerogel obtained in this Example is determined for shrinkage, water contact angle and heat conductivity. The following Table 4 shows the shrinkage, water contact angle and heat conductivity of monolithic silica aerogel hydrophobitized by using a dipping solution for 6-48 hours (6, 12, 24, 48 hours).
[0000]
TABLE 4
Dipping time
Shrinkage
Water contact
Heat conductivity
(h)
(%)
angle (°)
(W/m · K)
6
24.4
0
0.0128
12
22.3
103
0.0136
24
24.2
121
0.0128
48
22.6
139
0.0132
[0064] As can be seen from Table 4, the monolithic silica aerogel hydrophobitized with variable dipping times shows an increase in water contact angle as the dipping time increases, and maintains low shrinkage and heat conductivity.
Example 5
[0065] Monolithic silica aerogel is hydrophobitized by using a dipping process in the same manner as described in Example 1, except that different alkylsilane solutions are used. The alkylsilane solutions used in this Example include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane and phenyltrimethoxysilane solutions.
[0066] Each hydrophobic monolithic silica aerogel obtained in this Example is determined for shrinkage, water contact angle and heat conductivity. The following Table 5 shows the shrinkage, water contact angle and heat conductivity of monolithic silica aerogel hydrophobitized by using different dipping solutions.
[0000]
TABLE 5
Shrinkage
Water contact
Heat conductivity
Dipping solution
(%)
angle (°)
(W/m · K)
Methyltrimethoxysilane
24.2
121
0.0128
Ethyltrimethoxysilane
33.0
122
0.0127
Propyltrimethoxysilane
34.2
133
0.0131
Phenyltrimethoxysilane
38.3
132
0.0137
[0067] As can be seen from Table 5, when the monolithic silica aerogel is hydrophobitized by using different dipping solutions, methyltrimethoxysilane provides the lowest shrinkage and water contact angle, and propyltrimethoxysilane provides the highest water contact angle, and thus high hydrophobic property. Even when different dipping solutions are used, low heat conductivity is still maintained.
Example 6
[0068] Monolithic silica aerogel is hydrophobitized by using a dipping process in the same manner as described in Example 1, except that different solvents for a dipping solution are used. The solvents used in this Example include methanol, dimethylformamide and a mixed solvent of methanol/dimethylformamide (molar ratio=6/4).
[0069] Each hydrophobic monolithic silica aerogel obtained in this Example is determined for shrinkage, water contact angle and heat conductivity. The following Table 6 shows the shrinkage, water contact angle and heat conductivity of monolithic silica aerogel hydrophobitized by using different solvents for a dipping solution.
[0000]
TABLE 6
Shrinkage
Water contact
Heat conductivity
Dipping solution
(%)
angle (°)
(W/m · K)
Methanol
24.2
121
0.0128
Methanol/dimethyl-
20.8
126
0.0124
formamide
Dimethylformamide
18.3
133
0.0124
[0070] As can be seen from Table 6, when the monolithic silica aerogel is hydrophobitized by using different solvents for a dipping solution, dimethylformamide causes a decrease in shrinkage and an increase in water contact angle. Even when different solvents are used, low heat conductivity is still maintained.
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Provided is a method for preparing hydrophobic monolithic silica aerogel, comprising dipping monolithic wet silica gel obtained by using an alkoxide precursor into an alkylsilane solution as a dipping solution to perform hydrophobitization of the surface and inner part of the monolithic wet silica gel by a dipping process. The method is economical by virtue of the use of a small amount of alkylsilane compound and imparts hydrophobic property to monolithic silica aerogel simply in a cost efficient and time efficient manner. In addition, the method reduces shrinkage of hydrophobic monolithic silica aerogel, enables production of hydrophobic monolithic silica aerogel in a translucent form, and allows the hydrophobic monolithic silica aerogel to maintain low heat conductivity similar to the heat conductivity of hydrophilic silica aerogel. The hydrophobic monolithic silica aerogel may be used directly as a heat insulating panel by virtue of excellent hydrophobic property and heat insulating property.
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FIELD OF THE INVENTION
The present invention relates to recombinant hepatitis viral vectors useful for the expression of functional heterologous gene products in liver cells. These vectors also find use in anti-viral, anti-tumor and/or gene therapy, particularly for the correction of inherited single-gene defects.
BACKGROUND OF THE INVENTION
A large number of human genetic disorders could be treated by expression of missing or mutant genes in the liver. These disorders include familial hypercholesterolemia (deficiency of LDL receptors), ornithine transcarbamylase deficiency (a lethal liver metabolic disease), and hepatobiliary disease of cystitic fibrosis to name but a few metabolic disorders which effect the liver. In addition to correction of metabolic disorders effecting the liver, a number of primary tumors of the liver are known and would benefit from expression of anti-neoplastic genes in the liver [e.g., VDEPT; Huber et al. (1991) Proc. Natl. Acad. Sci. USA 88:8039].
In addition to permitting correction of inherited disorders which effect the liver, the ability to express genes in the liver permits gene therapy for a number of disorders whose primary defect is not located in the liver. For example, a number of inborn errors of metabolism result in high concentrations of toxic metabolites in the blood; transfer of a correct gene encoding the defective enzyme to the liver could permit metabolism of the toxic metabolites relieving the metabolic defect even though the site of the deficiency is outside of the liver (e.g., replacement of adenosine deaminase to remove toxic levels of adenosine and deoxyadenosine in the circulation of severe combined immunodeficiency patients).
Current approaches to targeting genes to the liver have focused upon ex vivo gene therapy. Ex vivo liver-directed gene therapy involves the surgical removal of liver cells, transduction of the liver cells in vitro (e.g., infection of the explanted cells with recombinant retroviral vectors) followed by injection of the genetically modified liver cells into the liver or spleen of the patient. A serious drawback for ex vivo gene therapy of the liver is the fact that hepatocyctes (i.e., liver cells) cannot be maintained and expanded in culture. Therefore, the success of ex vivo liver-directed gene therapy depends upon the ability to efficiently and stably engraft the genetically modified (i.e., transduced) hepatocyctes and their progeny. It has been reported that even under optimal conditions, autologous modified liver cells injected into the liver or spleen which engraft represent only a small percentage (less than 10%) of the total number of cells in the liver [Chowdhury et al. (1991) Science 254:1802]. Ectopic engraftment of transduced primary hepatocytes into the peritoneal cavity has been tried to address the problem of engraftment in the liver [Ledley, et al. (1987) Proc. Natl. Acad. Sci. USA 84:5335; Wilson et al. (1988) Proc. Natl. Acad. Sci. USA 85:3014 and Wolff et al. (1987) Proc. Natl. Acad. Sci. USA 84:3344].
Given the problems associated with ex vivo liver-directed gene therapy, in vivo approaches have been investigated for the transfer of genes into hepatocytes, including the use of recombinant retroviruses, recombinant adenoviruses, liposomes and molecular conjugates [Jaffe et al. (1992) Nature Gent. 1:372; Kaneda et al. (1989) Science 243:375; and Wu et al. (1989) J. Biol. Chem. 16985]. While these in vivo approaches do not suffer from the drawbacks associated with ex vivo liver-directed gene therapy, they do not provide a means to specifically target hepatocytes. In addition, several of these approaches require that a partial hepatectomy be performed in order to achieve prolonged expression of the transferred genes in vivo [Wilson (1992) J. Biol. Chem. 267:963].
Ideally, liver-directed gene therapy would be achieved by in vivo transfer of genes using vectors which specifically target hepatocytes. Hepatotrophic viruses, such as human hepatitis B virus (HBV), can be delivered via the circulation and their gene products are known to be expressed specifically in the liver. However, to date, the ability to express a foreign gene in the context of a HBV has not been reported. The art needs human HBV vectors capable of carrying and expressing foreign genes to allow in vivo liver-directed and liver-specific gene therapy.
SUMMARY OF THE INVENTION
The present invention relates to recombinant hepatitis viral vectors useful for the expression of functional heterologous gene products in liver cells. It is contemplated that these vectors will find use in anti-viral, anti-tumor and/or gene therapy, particularly for the correction of inherited single-gene defects. These novel recombinant vectors may be used to deliver genes to cells in vivo by a variety of means including infection and direct injection of vector DNA.
The present invention provides a recombinant hepatitis virus genome comprising heterologous gene sequences capable of expressing at least one functional heterologous gene product. The present invention is illustrated using recombinant HBV genomes (i.e., the human HBV); however, the invention contemplates the use of any hepatitis B virus, including but not limited to woodchuck hepatitis virus (WHV), ground squirrel hepatitis virus (GSHV), tree squirrel hepatitis virus (TSHV), duck hepatitis virus (DHBV) and heron hepatitis virus (HHBV). The art is well aware that the genomic organization of these various hepatitis B virus is similar and that the teachings of the present invention can be translated to other hepatitis B viruses (e.g., DHBV, WHV, etc).
It is contemplated that in some embodiments, the recombinant virus genome further comprises an endogenous viral promoter. In one embodiment, the viral promoter of the recombinant virus genome is selected from the group consisting of the core/pol promoter and the preS1 promoter. In another embodiment, the recombinant virus genome further comprises a heterologous promoter. In one embodiment with a heterologous promoter, the heterologous promoter of the recombinant virus genome is selected from the group consisting of the CMV-IE promoter, the human elongation factor 1α gene promoter, the SV40 enhancer/promoter, the Rous sarcoma virus long terminal repeat, the α-fetoprotein gene promoter and the recombinant Moloney murine leukemia virus long terminal repeat containing CMV-IE/HIV-1 TAR sequences listed in SEQ ID NO:16. In one preferred embodiment of the recombinant virus genome, the genome is replication competent. However, in an alternative embodiment, the recombinant virus genome is replication defective.
In one particularly preferred embodiment, the present invention provides a recombinant hepatitis B virus genome comprising pol gene sequences, X gene sequences and preS1/preS2/S gene sequences and heterologous gene sequences wherein the recombinant genome is capable of expressing at least one functional heterologous gene product. In one embodiment, the recombinant hepatitis B virus genome is replication defective; the replication defective virus may be capable of being packaged into infectious viral particles or alternatively it may exceed in size the packaging limit. In one embodiment of the replication-defective recombinant hepatitis B virus genome contains a deletion within the pol gene. It is contemplated that the deletion within the pol gene may be located within the preS/preS2/S gene sequences. However, it is also contemplated that the deletion may be located within the pol gene and the preS/preS2/S gene sequences. In addition, it is contemplated that the recombinant virus genome will lack a functional X and/or S gene. In embodiments of the present invention in which the genome lacks a functional S gene, it is contemplated that the recombinant virus genome further lacks functional preS1/S and preS2/S genes.
The present invention also provides methods for the encapsidation of a recombinant hepatitis B virus genome, comprising the steps of providing: i) a recombinant hepatitis B virus genome comprising pol gene sequences, X gene sequences and preS1/preS2/S gene sequences and heterologous gene sequences wherein the recombinant genome is capable of expressing at least one functional heterologous gene product and wherein the recombinant genome lacks the ability to produce at least one viral product required for packaging said viral genome; ii) at least one plasmid capable of providing in trans hepatitis B virus gene products sufficient to complement the recombinant viral genome lacking the ability to produce at least one viral product required for packaging; as well as a liver cell; and b) introducing the recombinant hepatitis virus genome and the plasmid(s) into the liver cell under conditions such that the recombinant hepatitis virus genome is encapsidated into viral particles. It is contemplated that the liver cell of the present invention be selected from the group consisting of human liver cells [including HepG2 cells (ATCC HB 8065), HuH7 cells, Hep 3B (ATCC HB 8064), WRL 68 (ATCC CL 48), Chang liver (ATCC CCL 13), SK-HEP-1 (ATCC HTB 52) and PLC/PRF/5 (ATCC CRL 8024)], avian liver cells (e.g., duck and chicken liver cells), non-human primate liver cells, and rodent liver cells. Any cell capable of expressing the viral gene products provided in trans and capable of express the gene products encoded by the recombinant viral genome (and capable of permitting replication of the viral genome if the genome is replication competent) may be employed.
In one embodiment of the method, the recombinant virus genome contains a deletion within the pol gene. In embodiments of the invention with pol gene deletion, it is contemplated that at least one plasmid used in the method encode the product of the hepatitis B virus pol gene. It is also contemplated that the recombinant virus genome contains a deletion within the preS/preS2/S gene sequences. In particular, it is contemplated that the plasmid encodes the products of the hepatitis B virus preS/preS2/S gene sequences. It is also contemplated that the recombinant virus genome contains a deletion within the pol gene and the preS/preS2/S gene sequences.
In another embodiment of the method, the plasmid encodes the products of the hepatitis B virus preS/preS2/S gene sequences and the product of the hepatitis B virus pol gene. In yet another embodiment, the recombinant virus genome lacks a functional X gene.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic representation of the HBVtat virus (monomer form opened at the unique EcoRI site) as contained on pTHBVT.
FIG. 1B is a schematic representation of the HBVtat virus (head to tail dimer form) as contained on pTHBVT-d.
FIG. 1C schematic representation of mutant HBVtat viruses which shows the location of the mutations introduced into the X gene (a) and the frameshift mutation introduced into the pol ORF (b).
FIG. 2 is an autoradiograph of CAT assays which illustrate transactivation of the HIV-1 LTR by HBVtat in HepG2 cells.
FIG. 3 is an autoradiograph of CAT assays which illustrate transactivation of the HIV-1 LTR by individual HBV gene products in HepG2 cells.
FIG. 4 is an autoradiograph of CAT assays which illustrate transactivation of the HIV-1 LTR by the pol mutant of HBVtat in HepG2 cells.
FIG. 5A is an autoradiograph of a Northern blot performed to detect RNA expressed from HBVtat in transfected HepG2 cells (HBV DNA used as probe).
FIG. 5B is autoradiograph of a Northern blot performed to detect RNA expressed from HBVtat in transfected HepG2 cells (tat DNA used as probe).
FIG. 6A is an autoradiograph showing endogenous polymerase activities in intracellular core particles and extracellular viral particles of HBVtat as compared to wild-type HBV.
FIG. 6B is an autoradiograph showing the endogenous polymerase activity of HBVtat complemented with HBsAg (L, M and S).
DEFINITIONS
To facilitate understanding of the invention, a number of terms are defined below.
As used herein, the term "hepatitis virus" refers to a hepatotrophic virus in the group termed hepadnaviruses. Hepatitis viruses include the human hepatitis B virus (HBV) which infects humans and certain non-human primates, woodchuck hepatitis virus (WHV), ground squirrel hepatitis virus (GSHV), tree squirrel hepatitis virus (TSHV), duck hepatitis virus (DHBV) and heron hepatitis virus (HHBV).
As used herein, the term "capable of expressing at least one functional heterologous gene product" when used in reference to a recombinant viral vector containing heterologous gene sequences means the viral vector is capable of producing a functional gene product from the heterologous gene sequences. A "functional" gene product is a gene product capable of carrying out the functions normally associated with that gene product. For example, a functional Tat protein is capable of transctivating the HIV-1 LTR. The functional heterologous gene product may be expressed as a fusion protein with viral protein sequences. A "functional HBV gene" (e.g., a functional X gene, a functional S gene) indicates that the HBV gene is capable of expressing a functional gene product (e.g., in the case of the S gene, a functional S gene is capable of expressing functional HBsAg). The location of the open reading frames (ORFs) encoding HBV gene products are known. For example, the start or ATG codon for the HBV X gene is located at nucleotides 1376-1378 of SEQ ID NO:1 (DNA sequence of the genome of HBV adw 2 in a linear form opened at the unique EcoRI site of the genome) and the stop codon for the X gene (TAA) is encoded by nucleotides 1838-1840 of SEQ ID NO:1. The start codon for the core gene is located at nucleotides 1873-1875 and the stop codon (TAG) is located at nucleotides 2458-2460 of SEQ ID NO:1. The start codon for the pol gene is located at nucleotides 2309-2311 and the stop codon (TGA) is located at nucleotides 1623-1625 of SEQ ID NO:1. The location of additional ORFs (e.g., precore, surface antigens, etc.) within SEQ ID NO:1 are known to the art.
Recombinant HBV genomes which lack gene sequences encoding gene products required for packaging of the viral genome may be encapsidated by providing the missing viral gene products in trans. Plasmids capable of expressing the missing gene products or helper virus capable of expressing the missing gene products may be transferred into a cell along with the defective genome. The defective genome will be packaged into mature viral particles as long as the transfected cell expresses all necessary viral gene products and the defective viral genome does not exceed the maximum packaging size.
Plasmids which are capable of providing in trans HBV gene products "sufficient to complement a recombinant viral genome deficient in at least one HBV gene product required for packaging viral DNA" are plasmids which direct the expression of the missing HBV gene products at a level sufficient to permit encapsidation of the deficient recombinant viral genome into mature viral particles (i.e., infectious particles).
A recombinant HBV genome which lacks a functional HBV gene (e.g., the X gene) is a genome which lacks the ability to produce a functional HBV gene product. The inability to produce a functional form of a given HBV gene product may be due to a deletion of all or a part of a HBV gene, point mutations, insertions, and/or frame-shift mutations which preclude expression of a functional gene product.
As used herein, the term "encapsidating" refers to the insertion of a viral genome into a mature viral particle (i.e., an infectious as opposed to a core viral particle when used in the context of HBV). The terms "encapsidating" and packaging" are used herein interchangeably.
A "liver cell" refers to any cell derived from a liver including primary hepatocytes, cultured liver cells, cells within the liver tissue of an animal (including a human) and hepatoma cell lines.
As used herein, the term "polyA + RNA" refers to RNA molecules having a stretch of adenine nucleotides at the 3' end. This polyadenine stretch is also referred to as a "poly-A tail". Eucaryotic mRNA molecules contain poly-A tails and are referred to as polyA + RNA.
As used herein, the term "in trans" is used in reference to complementation of a defective viral genome indicates that a piece of genetic material other than the viral genome encodes the viral gene products which cannot be expressed by the defective viral genome.
The term "trans-acting" is used in reference to the controlling effect of a regulatory gene on a gene present on a different chromosome. In contrast to promoters, repressors are not limited in their binding to the DNA molecule that includes their genetic information. Therefore, repressors are sometimes referred to as trans-acting control elements.
The term "trans-activation" as used herein refers to the activation of gene sequences by factors encoded by a regulatory gene which is not necessarily contiguous with the gene sequences which it binds to and activates. For example, the HIV-1 regulatory protein Tat is encoded by the tat gene and binds to and activates (i.e., trans-activates) expression from the HIV LTR.
As used herein, the term "cis" is used in reference to the presence of genes on the same chromosome. The term "cis-acting" is used in reference to the controlling effect of a regulatory gene on a gene present on the same chromosome. For example, promoters, which affect the synthesis of downstream mRNA are cis-acting control elements.
As used herein, the term "packaging signal" or "packaging sequence" refers to sequences located within the hepatitis B virus genome which are required for encapsidation of viral DNA during viral particle formation.
As used herein, the terms "hepatitis virus vector," "HBV vector" or grammatical equivalents are used in reference to hepatitis B viruses which have been modified so as to serve as vectors for introduction of nucleic acid into cells.
As used herein, the term "vector" is used in reference to nucleic acid molecules that transfer DNA segment(s) from one cell to another. The term "vehicle" is sometimes used interchangeably with "vector."
The term "expression vector" as used herein refers to a recombinant DNA molecule containing a desired coding sequence and appropriate nucleic acid sequences necessary for the expression of the operably linked coding sequence in a particular host organism. Nucleic acid sequences necessary for expression in procaryotes usually include a promoter, an operator (optional), and a ribosome binding site, often along with other sequences. Eucaryotic cells are known to utilize promoters, enhancers, and termination and polyadenylation signals.
The terms "in operable combination", "in operable order" and "operably linked" as used herein refer to the linkage of nucleic acid sequences in such a manner that a nucleic acid molecule capable of directing the transcription of a given gene and/or the synthesis of a desired protein molecule is produced. The term also refers to the linkage of amino acid sequences in such a manner so that a functional protein is produced.
The term "genetic cassette" as used herein refers to a fragment or segment of DNA containing a particular grouping of genetic elements. The cassette can be removed and inserted into a vector or plasmid as a single unit.
The term "transfection" as used herein refers to the introduction of foreign DNA into eucaryotic cells. Transfection may be accomplished by a variety of means known to the art including calcium phosphate-DNA co-precipitation, DEAE-dextran-mediated transfection, polybrene-mediated transfection, electroporation, microinjection, liposome fusion, lipofection, protoplast fusion, retroviral infection, and biolistics.
As used herein, the term "transduction" refers to the delivery of a gene(s) using a viral vector by means of infection rather than by transfection.
As used herein, the term "TATA element" or "TATA box" is used in reference to a segment of DNA, located approximately 19-27 base pairs upstream from the start point of eucaryotic structural genes and viral genes, to which RNA polymerase binds. The TATA box is approximately 7 base pairs in length, often comprising the sequence "TATAAAA." The TATA box is also sometimes referred to as the "Hogness box."
The term "CAAT box" or "CAAT element" refers to a conserved DNA sequence located approximately 75 bp upstream from the start point of eucaryotic structural genes, to which RNA polymerase binds.
As used herein, the term "tat" is used in reference to the HIV gene which encodes "Tat," a protein which induces high-level expression of HIV genes.
As used herein, the term "long terminal repeat (LTR)" is used in reference to domains of base pairs located at the ends of retroviral DNA's. These LTRs may be several hundred base pairs in length. LTR's often provide functions fundamental to the expression of most eucaryotic genes (e.g., promotion, initiation and polyadenylation of transcripts).
As used herein, the term "TAR" is used in reference to the "trans-activation response" genetic element located in the U5 region of the HIV LTR. This element mediates the action of tat, by physically binding to the viral trans-activator tat.
As used herein, the terms "complementary" or "complementarity" are used in reference to polynucleotides (i.e., a sequence of nucleotides) related by the base-pairing rules. For example, for the sequence "A-G-T," is complementary to the sequence "T-C-A." Complementarity may be "partial," in which only some of the nucleic acids' bases are matched according to the base pairing rules. Or, there may be "complete" or "total" complementarity between the nucleic acids. The degree of complementarity between nucleic acid strands has significant effects on the efficiency and strength of hybridization between nucleic acid strands. This is of particular importance in amplification reactions, as well as detection methods which depend upon binding between nucleic acids.
As used herein, the term "hybridization" is used in reference to the pairing of complementary nucleic acids. Hybridization and the strength of hybridization (i.e., the strength of the association between the nucleic acids) is impacted by such factors as the degree of complementary between the nucleic acids, stringency of the conditions involved, the T m of the formed hybrid, and the G:C ratio within the nucleic acids.
As used herein, the term "T m " is used in reference to the "melting temperature." The melting temperature is the temperature at which a population of double-stranded nucleic acid molecules becomes half dissociated into single strands. The equation for calculating the T m of nucleic acids is well known in the art. As indicated by standard references, a simple estimate of the T m value may be calculated by the equation: T m =81.5+0.41(% G+C), when a nucleic acid is in aqueous solution at 1M NaCl (see e.g., Anderson and Young, Quantitative Filter Hybridization, in Nucleic Acid Hybridization (1985). Other references include more sophisticated computations which take structural as well as sequence characteristics into account for the calculation of T m .
As used herein the term "stringency" is used in reference to the conditions of temperature, ionic strength, and the presence of other compounds such as organic solvents, under which nucleic acid hybridizations are conducted. With "high stringency" conditions, nucleic acid base pairing will occur only between nucleic acid fragments that have a high frequency of complementary base sequences. Thus, conditions of "weak" or "low" stringency are often required with nucleic acids that are derived from organisms that are genetically diverse, as the frequency of complementary sequences is usually less.
As used herein, the term "primer" refers to an oligonucleotide, whether occurring naturally as in a purified restriction digest or produced synthetically, which is capable of acting as a point of initiation of synthesis when placed under conditions in which synthesis of a primer extension product which is complementary to a nucleic acid strand is induced, (i.e., in the presence of nucleotides and an inducing agent such as DNA polymerase and at a suitable temperature and pH). The primer is preferably single stranded for maximum efficiency in amplification, but may alternatively be double stranded. If double stranded, the primer is first treated to separate its strands before being used to prepare extension products. Preferably, the primer is an oligodeoxyribonucleotide. The primer must be sufficiently long to prime the synthesis of extension products in the presence of the inducing agent. The exact lengths of the primers will depend on many factors, including temperature, source of primer and the use of the method. Primers are used in the polymerase chain reaction for the amplification of a specific target sequence.
As used herein, the term "probe" refers to an oligonucleotide (i.e., a sequence of nucleotides), whether occurring naturally as in a purified restriction digest or produced synthetically, which is capable of hybridizing to another oligonucleotide of interest. Probes are useful in the detection, identification and isolation of particular gene sequences. It is contemplated that any probe used in the present invention will be labelled with any "reporter molecule," so that is detectable in any detection system, including, but not limited to enzyme (e.g., ELISA, as well as enzyme-based histochemical assays), fluorescent, radioactive, and luminescent systems. It is further contemplated that the oligonucleotide of interest (i.e., to be detected) will be labelled with a reporter molecule. It is also contemplated that both the probe and oligonucleotide of interest will be labelled. It is not intended that the present invention be limited to any particular detection system or label.
As used herein, the term "target" refers to the region of nucleic acid bounded by the primers used for polymerase chain reaction. Thus, the "target" is sought to be sorted out from other nucleic acid sequences. A "segment" is defined as a region of nucleic acid within the target sequence.
As used herein, the term "polymerase chain reaction" ("PCR") refers to the method of K. B. Mullis U.S. Pat. Nos. 4,683,195 and 4,683,202, hereby incorporated by reference, which describe a method for increasing the concentration of a segment of a target sequence in a mixture of genomic DNA without cloning or purification. This process for amplifying the target sequence consists of introducing a large excess of two oligonucleotide primers to the DNA mixture containing the desired target sequence, followed by a precise sequence of thermal cycling in the presence of a DNA polymerase. The two primers are complementary to their respective strands of the double stranded target sequence. To effect amplification, the mixture is denatured and the primers then annealed to their complementary sequences within the target molecule. Following annealing, the primers are extended with a polymerase so as to form a new pair of complementary strands. The steps of denaturation, primer annealing and polymerase extension can be repeated many times (i.e., denaturation, annealing and extension constitute one "cycle"; there can be numerous "cycles") to obtain a high concentration of an amplified segment of the desired target sequence. The length of the amplified segment of the desired target sequence is determined by the relative positions of the primers with respect to each other, and therefore, this length is a controllable parameter. By virtue of the repeating aspect of the process, the method is referred to as the "polymerase chain reaction" (hereinafter "PCR"). Because the desired amplified segments of the target sequence become the predominant sequences (in terms of concentration) in the mixture, they are said to be "PCR amplified".
With PCR, it is possible to amplify a single copy of a specific target sequence in genomic DNA to a level detectable by several different methodologies (e.g., hybridization with a labeled probe; incorporation of biotinylated primers followed by avidin-enzyme conjugate detection; incorporation of 32 P-labeled deoxynucleotide triphosphates, such as dCTP or dATP, into the amplified segment). In addition to genomic DNA, any oligonucleotide sequence can be amplified with the appropriate set of primer molecules. In particular, the amplified segments created by the PCR process itself are, themselves, efficient templates for subsequent PCR amplifications. Amplified target sequences may be used to obtain segments of DNA (e.g., genes) for insertion into recombinant HBV vectors.
As used herein, the terms "PCR product" and "amplification product" refer to the resultant mixture of compounds after two or more cycles of the PCR steps of denaturation, annealing and extension are complete. These terms encompass the case where there has been amplification of one or more segments of one or more target sequences.
As used herein, the terms "restriction endonucleases" and "restriction enzymes" refer to bacterial enzymes, each of which cut double-stranded DNA at or near a specific nucleotide sequence.
As used herein, the term "recombinant DNA molecule" as used herein refers to a DNA molecule which is comprised of segments of DNA joined together by means of molecular biological techniques.
DNA molecules are said to have "5' ends" and "3' ends" because mononucleotides are reacted to make oligonucleotides in a manner such that the 5' phosphate of one mononucleotide pentose ring is attached to the 3' oxygen of its neighbor in one direction via a phosphodiester linkage. Therefore, an end of an oligonucleotides referred to as the "5' end" if its 5' phosphate is not linked to the 3' oxygen of a mononucleotide pentose ring and as the "3' end" if its 3' oxygen is not linked to a 5' phosphate of a subsequent mononucleotide pentose ring. As used herein, a nucleic acid sequence, even if internal to a larger oligonucleotide, also may be said to have 5' and 3' ends. In either a linear or circular DNA molecule, discrete elements are referred to as being "upstream" or 5' of the "downstream" or 3' elements. This terminology reflects the fact that transcription proceeds in a 5' to 3' fashion along the DNA strand. The promoter and enhancer elements which direct transcription of a linked gene are generally located 5' or upstream of the coding region However, enhancer elements can exert their effect even when located 3' of the promoter element and the coding region. Transcription termination and polyadenylation signals are located 3' or downstream of the coding region.
As used herein, the term "an oligonucleotide having a nucleotide sequence encoding a gene" means a DNA sequence comprising the coding region of a gene or in other words the DNA sequence which encodes a gene product. The coding region may be present in either a cDNA or genomic DNA form. Suitable control elements such as enhancers/promoters, splice junctions, polyadenylation signals, etc. may be placed in close proximity to the coding region of the gene if needed to permit proper initiation of transcription and/or correct processing of the primary RNA transcript. Alternatively, the coding region utilized in the expression vectors of the present invention may contain endogenous enhancers/promoters, splice junctions, intervening sequences, polyadenylation signals, etc. or a combination of both endogenous and exogenous control elements.
As used herein, the term "transcription unit" refers to the segment of DNA between the sites of initiation and termination of transcription and the regulatory elements necessary for the efficient initiation and termination. For example, a segment of DNA comprising an enhancer/promoter, a coding region and a termination and polyadenylation sequence comprises a transcription unit.
As used herein, the term "regulatory element" refers to a genetic element which controls some aspect of the expression of nucleic acid sequences. For example, a promoter is a regulatory element which facilitates the initiation of transcription of an operably linked coding region. Other regulatory elements are splicing signals, polyadenylation signals, termination signals, etc. (defined infra).
Transcriptional control signals in eucaryotes comprise "promoter" and "enhancer" elements. Promoters and enhancers consist of short arrays of DNA sequences that interact specifically with cellular proteins involved in transcription [Maniatis, T. et al, Science 236:1237 (1987)]. Promoter and enhancer elements have been isolated from a variety of eucaryotic sources including genes in yeast, insect and mammalian cells and viruses (analogous control elements, i.e., promoters, are also found in procaryotes). The selection of a particular promoter and enhancer depends on what cell type is to be used to express the protein of interest. Some eucaryotic promoters and enhancers have a broad host range while others are functional in a limited subset of cell types [for review see Voss, S. D. et al., Trends Biochem. Sci., 11:287 (1986) and Maniatis, T. et al., supra (1987)]. For example, the SV40 early gene enhancer is very active in a wide variety of cell types from many mammalian species and has been widely used for the expression of proteins in mammalian cells [Dijkema, R. et al., EMBO J. 4:761 (1985)]. Two other examples of promoter/enhancer elements active in a broad range of mammalian cell types are those from the human elongation factor 1α gene [Uetsuki, T. et al., J. Biol. Chem., 264:5791 (1989), Kim, D. W. et al., Gene 91:217 (1990) and Mizushima, S. and Nagata, S., Nuc. Acids. Res., 18:5322 (1990)] and the long terminal repeats of the Rous sarcoma virus [Gorman, C. M. et al., Proc. Natl. Acad. Sci. USA 79:6777 (1982)] and the human cytomegalovirus [Boshart, M. et al., Cell 41:521 (1985)].
As used herein, the term "promoter/enhancer" denotes a segment of DNA which contains sequences capable of providing both promoter and enhancer functions (i.e., the functions provided by a promoter element and an enhancer element, see above for a discussion of these functions). For example, the long terminal repeats of retroviruses contain both promoter and enhancer functions. The enhancer/promoter may be "endogenous" or "exogenous" or "heterologous." An "endogenous" enhancer/promoter is one which is naturally linked with a given gene in the genome. An "exogenous" or "heterologous" enhancer/promoter is one which is placed in juxtaposition to a gene by means of genetic manipulation (i.e., molecular biological techniques) such that transcription of that gene is directed by the linked enhancer/promoter.
The term "factor" refers to a protein or group of proteins necessary for the transcription or replication of a DNA sequence. For example, SV40 T antigen is a replication factor which is necessary for the replication of DNA sequences containing the SV40 origin of replication. Transcription factors are proteins which bind to regulatory elements such as promoters and enhancers and facilitate the initiation of transcription of a gene.
Promoters and enhancers may bind to specific factors which increase the rate of activity from the promoter or enhancer. These factors may be present in all cell types or may be expressed in a tissue-specific manner or in virus infected cells. In the absence of such a factor the promoter may be inactive or may produce a low level of transcriptional activity. Such a low level of activity is referred to as a baseline or "basal" rate of activity. Additionally, viral promoter and enhancers may bind to factors encoded by the virus such that the viral promoter or enhancer is "activated" in the presence of the viral factor (in a virus infected cell or in a cell expressing the viral factor). The level of activity in the presence of the factor (i.e., activity "induced" by the factor) will be higher than the basal rate.
The term "stable transfection" or "stably transfected" refers to the introduction and integration of foreign DNA into the genome of the transfected cell. The term "stable transfectant" refers to a cell which has stably integrated foreign DNA into the genomic DNA.
The term "transient transfection" or "transiently transfected" refers to the introduction of foreign DNA into a cell where the foreign DNA fails to integrate into the genome of the transfected cell. The foreign DNA persists in the nucleus of the transfected cell for several days. During this time the foreign DNA is subject to the regulatory controls that govern the expression of endogenous genes in the chromosomes. The term "transient transfectant" refers to cells which have taken up foreign DNA but have failed to integrate this DNA.
As used herein, the term "gene of interest" refers to the gene inserted into the polylinker of an expression vector. When the gene of interest encodes a gene which provides a therapeutic function (such as an anti-tumor gene), the gene of interest may be alternatively called a remedial gene.
As used herein, the term "remedial gene" refers to a gene whose expression is desired in a cell to correct an error in cellular metabolism, to inactivate a pathogen or to kill a cancerous cell. For example, the adenosine deaminase (ADA) gene is the remedial gene when carried on a retroviral vector used to correct ADA deficiency in a patient.
As used herein, the terms "nucleic acid molecule encoding," "DNA sequence encoding," and "DNA encoding" refer to the order or sequence of deoxyribonucleotides along a strand of deoxyribonucleic acid. The order of these deoxyribonucleotides determines the order of amino acids along the polypeptide (protein) chain. The DNA sequence thus codes for the amino acid sequence.
The term "Northern Blot" as used herein refers to the analysis of RNA by electrophoresis of RNA on agarose gels to fractionate the RNA according to size followed by transfer of the RNA from the gel to a solid support, such as nitrocellulose or a nylon membrane. The immobilized RNA is then probed with a labeled probe to detect RNA species complementary to the probe used. Northern blots are a standard tool of molecular biologists (Sambrook, J. et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Press, Cold Spring Harbor, N.Y., pp 7.39-7.52). "Southern blot" refers to an analogous technique in which DNA rather than RNA is separated and analyzed.
The term "dot blot" as used herein refers to spotting a sample of containing protein or nucleic acid onto a solid support. The solid support is then probed with a labeled nucleic acid or antibody probe to detect the protein or nucleic acid species of interest. Alternatively the reaction products of an assay containing a radioactive substrate can be spotted onto a solid support and the unincorporated substrate washed prior to exposure of the support to X-ray film.
DESCRIPTION OF THE INVENTION
The present invention provides for the first time recombinant human hepatitis B virus (HBV) vectors capable of expressing functional heterologous gene products. The description of the invention is divided into: I. Hepatitis Viruses; II. Construction of Recombinant HBV Vectors; and III. Expression of Functional Heterologous Genes in Recombinant HBV Vectors.
I. Hepatitis Viruses
Hepadnaviruses include hepatitis B virus (HBV), woodchuck hepatitis virus (WHV), ground squirrel hepatitis virus (GSHV), tree squirrel hepatitis virus (TSHV), duck hepatitis virus (DHBV) and heron hepatitis virus (HHBV). HBV infects only humans and some non-human primates. Hepatitis viruses are hepatotropic viruses which comprise the smallest DNA viruses known; the genome of hepadnaviruses are only about 3200 base pairs in size.
Hepadnaviruses have genomes which comprise a circular DNA molecule which is only partially double-stranded (termed open circular or ocDNA). A cohesive overlap maintains the circular structure of the viral DNA; the plus and minus strands of the viral genome contain short direct repeats (DR1 and DR2) which form the cohesive overlap. DR1 and DR2 are important for replication of the viral DNA. Following attachment to and entry of HBV particles into liver cells, the virus is uncoated and the ocDNA is transported to the nucleus. The viral genome can then replicate and viral transcripts can be generated or the viral DNA can persist in a latent state [Blum et al. (1988) Liver 8:307]; the viral DNA can also integrate into the host's genome (the integrated viral DNA is always subgenomic in size and frequently contains rearrangement; pregenomic RNA is not transcribed from the integrated viral DNA). The presence of integrated HBV sequences is associated with hepatocellular carcinoma (HCC) in humans, rodents and birds.
Viral replication involves repair of the ocDNA to form covalently closed circular DNA (cccDNA); cccDNA serves as the template for transcription to form the RNA pregenome. The RNA pregenome is transported to the cytoplasm where it is packaged into core particles. Reverse transcription of the RNA pregenome occurs in these core particles to form a new minus strand of the viral DNA. Plus strand DNA synthesis then occurs using the minus strand as template; an intramolecular template switch (which is dependent upon the presence of the DRs) occurs to permit completion of the plus strand DNA and the formation of cccDNA. During the synthesis of the plus and minus DNA strands, core particles are assembled into mature virions by coating of the core particles with surface antigens. The mature virions are then exported from the liver cell.
The genomic organization of these viruses is extremely compact and efficiently organized with overlapping open reading frames (ORFs) [Ganem and Varmus (1987) Ann. Rev. Biochem. 56:651 and Nassal and Schaller (1993) Trends Microbiol. 1:221]. Hepatitis B virus (HBV), the prototype of hepadnaviruses and causative agent for human hepatitis, carries four major overlapping ORFs: preS1/preS2/S (collectively known as the envelope or surface gene), preC/C, X and P. The envelope gene contains the preS1, preS2 and S regions which are delineated by three in-frame initiation codons and code for three envelope proteins: large (L), middle (M) and major (S). The preC/C gene contains the preC and C regions, also delineated by two in-frame initiation codons, which code for secreted HBV e antigen (HBeAg) and capsid or core protein (HBcAg). The X gene codes for the transactivating protein which has activity on HBV enhancers and other cellular genes [Rossner (1992) J. Med. Virol. 36:101]. The C-terminus of the X gene overlaps with the N-terminus of the preC/C gene. The P or polymerase (pol) gene contains the longest ORF. It encompasses about 80% of the entire viral genome and overlaps with the C-terminus of the preC/C gene, the entire envelope gene and the N-terminus of the X gene. The product of the pol gene (designated as pol protein) contains three major functional domains: the terminal protein domain at the N-terminus, the reverse transcriptase/DNA polymerase in the central domain and the RNase H domain at the C-terminus [Bartenschlager and Schaller (1988) EMBO J. 7:4185 and Radziwill et al. (1990) J. Virol. 64:613]. The terminal protein and reverse transcriptase/DNA polymerase domains are separated by a spacer or tether region. Four promoter elements; the preS1, preS2/S, X and C or core/pol promoters, which regulate transcription of pregenomic and subgenomic messengers for expression of the corresponding genes, have been identified on the HBV genome [for a review see Schaller and Fischer (1991) Curr. Top. Microbiol. Immunol. 168:21]. Almost all nucleotides appear to be included in coding sequences and are therefore indispensable for the generation of infectious viral particles containing replication competent virus. Only the spacer or tether region may be non-essential for the pol gene function or HBV replication [Chang et al. (1990) J. Virol. 64:5553 and Radziwill et al. (1990), supra].
To date, HBV or other hepadnaviruses have not been engineered and used as gene transfer tools in recombinant DNA technology. Since HBV infection is known to be primarily specific for liver cells, the ability to use HBV as a recombinant vector or delivery system would be very useful for targeting a therapeutic gene(s) to liver cells. Several animal viruses have been successfully used as gene delivery vectors. Retroviruses, for example, which appear to be evolutionarily related to hepadnaviruses, have been successfully manipulated and used to deliver genes in vitro and in vivo [Eglitis et al. (1985) Science 230:1395; Miller et al. (1993) Methods Enzymol. 217:581; and Naldini et al. (1996) Science 272:263]. However, existing retroviral vectors, as well as other animal viruses used to deliver foreign genes [e.g., adenovirus, adeno-associated virus (AAV), etc] are not liver-specific with regard to either infection or expression.
The unusually efficient genome of HBV is a factor regarded by the art as a limitation on the ability to manipulate or engineer the HBV genome. Mutations, insertions or deletions in many regions of the HBV genome have deleterious effects on viral gene expression and replication [Beames and Lanford (1995) J. Virol. 69:6833; Faruqi et al. (1991) Virol. 183:764; Machein et al. (1992) Arch. Virol. [Suppl] 4:133; Melegari et al. (1994) Virol. 199:292; Nakatake et al. (1993) Virol. 95:305; and Radziwill et al. (1990), supra]. The tether region of the pol gene, however, seems to be manipulable or even dispensable. Computer sequence analysis shows that this region is located upstream of the preS1 gene and overlaps with the preS1 and preS2 regions [Faruqi et al. (1991), supra and Radziwill et al. (1990), supra]. Part of the tether region, however, does not overlap with any other HBV genes. A mutational analysis of the pol gene of HBV has demonstrated that up to 90 codons of the intervening tether sequence can be deleted without significant loss of the endogenous polymerase activity [Radziwill et al. (1990), supra]. It has also been shown that such a deletion has no effect on the RNA encapsidation process [Bartenschlager et al. (1990) J. Virol. 64:5324]. Mutants of HBV containing deletions in the preS1 region which overlaps the tether region are capable of replication [Melegari et al. (1994), supra]. The duck hepatitis B virus (DHBV) genome carrying the gene for protein A (369 bp encoding 123 amino acids) inserted in the tether region also retains the capability of expressing an active endogenous polymerase [Chang et al. (1990), supra]; this recombinant replication defective DHBV however did not direct the expression of functional protein A (i.e., no protein capable of binding to immunoglobulin G-Sepharose was detected in lysates of cells infected with this recombinant DHBV). This region, moreover, tolerates many mutations resulting in amino acid changes [Hirsch et al. (1990) Nature 344:552 and Li et al. (1989) J. Virol. 63:4965]. The tether region, therefore, seems to be dispensable for HBV replication and appears to be the most suitable site for manipulating the HBV genome. However, to date, the expression and functional activity of a foreign gene inserted in the tether region or in any other regions in the HBV genome has not been reported.
The present invention provides methods for the successful manipulation of the HBV genome to accommodate a foreign gene whose functional activity can be demonstrated in the context of the full length HBV genome in hepatoma cell lines. Recombinant HBV vectors containing the HIV-1 tat gene in the tether region were constructed (HBVtat recombinants). Transient expression in hepatoma cell cultures shows that the tat gene contained on these HBV vectors is expressed with functional activity. The HBVtat recombinant exhibits functional polymerase activity, albeit at a reduced level compared to the wild type HBV. The expression of other HBV genes and the capacity to form virus particles does not seem to be affected by the foreign gene insertion. The HBVtat recombinants of the present invention illustrate the production of replication competent HBV vectors capable of directing the functional expression of foreign gene sequences. The present invention also provides replication defective recombinant HBV vectors which may delivered to cells within viral particles (i.e., they may be packaged or encapsidated) or which may be delivered to cells via injection of the recombinant HBV DNA. Each category of recombinant HBV vectors is discussed below.
II. Construction of Recombinant HBV Vectors
The present invention provides recombinant HBV vectors which are capable of expressing functional heterologous gene products. The HBV recombinant vector may be designed so as to be replication competent or replication defective. The HBV recombinant vector may be capable of being packaged into infectious viral particles or may be a non-infectious virus. "Replication competent" viruses are capable of synthesizing additional copies of the viral genetic material. A replication competent virus need not be capable of producing infectious viral particles, although it may be capable of producing infectious viral particles. "Replication defective" viruses are incapable of synthesizing additional copies of the viral genome. Replication defective viruses may be encapsidated into infectious viral particles by providing in trans the viral proteins required to coat the viral genome with a mature viral particle. Infection of a cell with a replication defective recombinant viral vector will result in the transfer of the viral genome to the cell but will not result in the intracellular synthesis of the recombinant viral genome.
A. Replication Competent HBV Vectors
Replication competent recombinant HBV vectors contain heterologous gene sequences inserted into the tether region of HBV. The inserted heterologous sequences are inserted in such a manner that the reading frame for the pol gene and the surface antigen genes (preS1/preS2/S gene) is maintained. This type of vector illustrated herein by the construction of the recombinant HBVtat virus (Ex. 1). The HBVtat virus contains the HIV-1 tat gene in the tether region of HBV. This recombinant virus is replication competent, expresses functional Tat, functional pol activity, functional surface antigens and produces extracellular viral particles (Exs. 2-5). The production of functional pol activity, functional surface antigens and extracellular viral particles and the incorporation of nucleotides into the viral template (i.e., evidence of viral replication) is sufficient evidence to demonstrate the production of infectious recombinant viral particles. Direct demonstration of the production of infectious recombinant particles may be achieved using the protease treatment of extracellular recombinant viral particles and infection of a liver cell line as described in Example 6.
Replication competent HBV vectors can be delivered to liver cells via infection or by transfer of the recombinant viral DNA (e.g., injection of naked DNA, lipofection, electroporation, etc.). If the recombinant HBV vector is to be delivered to cells via infection, the size of the heterologous gene sequences must create a viral genome which does not exceed the packaging capacity; the maximum size of the insert should be less than or equal to about 700-800 bp.
Replication competent viruses which have a genome too large to be packaged (i.e., non-infectious recombinant viruses) may be delivered to the cell using any suitable gene transfer method (e.g., lipofection, electroporation, calcium phosphate-DNA coprecipitation, DEAE-dextran mediated transfection, injection, including microinjection, of DNA, etc.). If the recombinant non-infectious HBV vector is to be used for in vivo delivery of heterologous genes, direct injection of naked DNA into the liver of the recipient may be employed as described in Example 7. If the recombinant non-infectious HBV vector is to be used for ex vivo delivery of heterologous genes, any means of transferring DNA to cells known to the art may be employed.
B. Replication Defective HBV Vectors
The present invention also provides recombinant HBV vectors which are replication defective; these viruses contain deletions or alterations in the HBV sequences which renders the recombinant virus incapable of replication. Replication defective recombinant HBV may be encapsidated by providing in trans viral gene products such as pol and/or surface antigens which are not produced by the recombinant HBV vector. As long as the size of the recombinant HBV genome is within the packaging limit for the HBV particle, recombinant HBV particles will be produced.
The present invention provides replication defective HBV vectors in which the majority of the pol ORF has been deleted to permit the insertion of heterologous gene sequences up to about 2.2 kb in length. The total genome size of these recombinant HBV vectors is within the packaging limit of the HBV particle. Example 6 provides details for the construction of these viruses and methods for the packaging of the replication defective viral genomes for delivery via infection.
III. Expression of Functional Heterologous Genes in Recombinant HBV Vectors
The heterologous gene sequences inserted into the recombinant HBV vectors of the present invention may be expressed using either endogenous HBV promoters or enhancer/promoters or using heterologous promoters or enhancer/promoters.
A. Endogenous Viral Promoters
The transcription of the heterologous gene sequences contained within the recombinant HBV vectors of the present invention may be directed by an endogenous (i.e., an HBV) promoter. A number of endogenous promoters are present within the HBV genome; these promoters control the transcription of the viral genes. As described in the examples below, transcription of the heterologous gene sequences inserted into the tether region of the HBV pol gene is controlled by the preS1 promoter. The preS1 promoter (i.e., the TATA box) is located between nt 2784-2790 of SEQ ID NO:1 (the wild-type HBV adw2 genome). The location of other HBV promoters and enhancers (e.g., the core/pol promoter) is known to the art and these may be employed for the expression of heterologous gene sequences contained within the recombinant HBV vectors of the present invention.
B. Heterologous Promoters
The transcription of the heterologous gene sequences contained within the recombinant HBV vectors of the present invention may be directed by a heterologous promoter. When a heterologous promoter (or enhancer/promoter) is employed for the expression of the heterologous gene sequences, the heterologous promoter is placed in the same transcriptional orientation as the endogenous promoter(s) present on the recombinant HBV vector.
The heterologous promoter chosen will allow for high levels of transcription in the host cell (i.e., in liver cells). The expression of the heterologous gene sequences may be driven by a promoter or by an enhancer and promoter. Promoters and enhancers are short arrays of DNA which direct the transcription of a linked gene. While not intending to limit the invention to the use of any particular heterologous promoters and/or enhancer elements, the following are preferred promoter/enhancer elements as they direct high levels of expression of operably linked genes in a wide variety of cell types including liver cells.
i) The SV40 enhancer/promoter is very active in a wide variety of cell types from many mammalian species [Dijkema, R. et al., EMBO J., 4:761 (1985)]. The SV40 enhancer/promoter is available on a number of expression vectors [e.g., pZeoSV (Invitrogen)].
ii) The SRα enhancer promoter comprises the R-U5 sequences from the LTR of the human T-cell leukemia virus-1 (HTLV-1) and sequences from the SV40 enhancer/promoter [Takebe, Y. et al., Mol. Cell. Biol., 8:466 (1988)]. The HTLV-1 sequences are placed immediately downstream of the SV40 early promoter. These HTLV-1 sequences are located downstream of the transcriptional start site and are present as 5' nontranslated regions on the RNA transcript. The addition of the HTLV-1 sequences increases expression from the SV40 enhancer/promoter.
iii) The human cytomegalovirus (CMV) major immediate early gene (IE) enhancer/promoter is active in a broad range of cell types [Boshart, M. et al., Cell 41:521 (1985)]. The 293 cell line (ATCC CRL 1573) [J. Gen. Virol., 36:59 (1977), Virology 77:319 (1977) and Virology 86:10 (1978)], an adenovirus transformed human embryonic kidney cell line, is particularly advantageous as a host cell line for vectors containing the CMV enhancer/promoter as the adenovirus IE gene products increase the level of transcription from the CMV enhancer/promoter. The CMV-IE enhancer/promoter is available on a number of vectors [e.g., pcDNA I, pcDNA I/Amp, pCDM8 (all from Invitrogen)].
iv) The recombinant LTR whose sequence is provided in SEQ ID NO:16 is a Moloney murine leukemia LTR containing CMV-IE/HIV-1 TAR sequences. This recombinant LTR is very active in human liver cells [Robinson et al. (1995), supra].
v) The enhancer/promoter from the human elongation factor 1α gene is abundantly transcribed in a very broad range of cell types [Uetsuki, T. et al., J. Biol. Chem., 264:5791 (1989) and Mizushima, S. and Nagata, S., Nuc. Acids. Res. 18:5322 (1990)]. The sequence of this enhancer/promoter is provided in SEQ ID NO:15.
vi) The promoter from the α-fetoprotein gene; this promoter is expressed at high levels in liver cells (e.g., hepatoma cells). Promoters and enhancer/promoters from other genes expressed at high levels in liver are suitable for use in the HBV vectors of the present invention.
vii) The enhancer/promoter from the Rous sarcoma virus (RSV) LTR. This enhancer/promoter is available on a number of expression vectors [e.g., pREP4, pREP7, pRc/RSV pEBVHis (all from Invitrogen)].
EXPERIMENTAL
The following examples serve to illustrate certain preferred embodiments and aspects of the present invention and are not to be construed as limiting the scope thereof.
In the experimental disclosure which follows, the following abbreviations apply: M (molar); mM (millimolar); μM (micromolar); mol (moles); mmol (millimoles); μmol (micromoles); nmol (nanomoles); g (gravity); gm (grams); mg (milligrams); μg (micrograms); pg (picograms); L (liters); ml (milliliters); μl (microliters); cm (centimeters); mm (millimeters); μm (micrometers); nm (nanometers); hr (hour); min (minute); msec (millisecond); °C. (degrees Centigrade); AMP (adenosine 5'-monophosphate); cDNA (copy or complimentary DNA); DTT (dithiotheritol); ddH 2 O (double distilled water); dNTP (deoxyribonucleotide triphosphate); rNTP (ribonucleotide triphosphate); ddNTP (dideoxyribonucleotide triphosphate); bp (base pair); kb (kilo base pair); TLC (thin layer chromatography); tRNA (transfer RNA); nt (nucleotide); VRC (vanadyl ribonucleoside complex); RNase (ribonuclease); DNase (deoxyribonuclease); poly A (polyriboadenylic acid); PBS (phosphate buffered saline); OD (optical density); HEPES (N-[2-Hydroxyethyl]piperazine-N-[2-ethanesulfonic acid]); HBS (HEPES buffered saline); SDS (sodium dodecyl sulfate); Tris-HCl (tris[Hydroxymethyl]aminomethane-hydrochloride); rpm (revolutions per minute); ligation buffer (50 mM Tris-HCl, 10 mM MgCl 2 , 10 mM dithiothreitol, 25 μg/ml bovine serum albumin, and 26 μM NAD+, and pH 7.8); EGTA (ethylene glycol-bis(β-aminoethyl ether) N, N, N', N'-tetraacetic acid); EDTA (ethylenediaminetetracetic acid); ELISA (enzyme linked immunosorbant assay); LB (Luria-Bertani broth: 10 g tryptone, 5 g yeast extract, and 10 g NaCl per liter, pH adjusted to 7.5 with 1N NaOH); superbroth (12 g tryptone, 24 g yeast extract, 5 g glycerol, 3.8 g KH 2 PO 4 and 12.5 g, K 2 HPO 4 per liter); DMEM (Dulbecco's modified Eagle's medium); ABI (Applied Biosystems Inc., Foster City, Calif.); Amersham (Amersham Corporation, Arlington Heights, Ill.); ATCC (American Type Culture Collection, Rockville, MY); Beckman (Beckman Instruments Inc., Fullerton Calif.); BM (Boehringer Mannheim Biochemicals, Indianapolis, Ind.); Bio-101 (Bio-101, Vista, Calif.); BioRad (BioRad, Richmond, Calif.); Brinkmann (Brinkmann Instruments Inc. Wesbury, N.Y.); BRL, Gibco BRL and Life Technologies (Bethesda Research Laboratories, Life Technologies Inc., Gaithersburg, Md.); CRI (Collaborative Research Inc. Bedford, Mass.); Eastman Kodak (Eastman Kodak Co., Rochester, N.Y.); Eppendorf (Eppendorf, Eppendorf North America, Inc., Madison, Wis.); Falcon (Becton Dickenson Labware, Lincoln Park, N.J.); IBI (International Biotechnologies, Inc., New Haven, Conn.); ICN (ICN Biomedicals, Inc., Costa Mesa, Calif.); Invitrogen (Invitrogen, San Diego, Calif.); New Brunswick (New Brunswick Scientific Co. Inc., Edison, N.J.); NEB (New England BioLabs Inc., Beverly, Mass.); NEN (Du Pont NEN Products, Boston, Mass.); Nichols Institute Diagnostics (Nichols Institute Diagnostics, San Juan Capistrano, Calif.); Pharmacia (Pharmacia LKB Gaithersburg, Md.); Promega (Promega Corporation, Madison, Wis.); Stratagene (Stratagene Cloning Systems, La Jolla, Calif.); UVP (UVP, Inc., San Gabreil, Calif.); USB (United States Biochemical Corp., Cleveland, Ohio); and Whatman (Whatman Lab. Products Inc, Clifton, N.J.).
Unless otherwise indicated, all restriction enzymes were obtained from New England Biolabs and used according to the manufacturers directions. Unless otherwise indicated, synthetic oligonucleotides were synthesized using an ABI DNA synthesizer, Model No. 391.
EXAMPLE 1
Construction of a Recombinant HBV Vector
In order to investigate the ability to insert and express a foreign gene in the context of the HBV genome, the entire HIV-1 tat gene was inserted into the tether region of the pol gene. This construct and a number of intermediate constructs are described below.
a) Construction of pTHBV and pTHBVT-d
The full length genome (EcoRI-EcoRI) of HBV adw2 subtype was inserted into the pT7T318U vector (Pharmacia Biotech) which had been digested with EcoRI to create the plasmid pTHBV. pTHBV contains the entire HBV genome (subtype adw2). The DNA sequence of the HBV genome contained within pTHBV is listed in SEQ ID NO:1.
A replication competent plasmid for wild-type HBV was constructed by ligation of two head-to-tail copies of the full-length HBV (EcoRI-EcoRI) sequence into the pT7T3 18U vector. The resulting plasmid was termed pTHBV-d. The DNA sequence of pTHBV-d is listed in SEQ ID NO:2. In SEQ ID NO:2, the HBV sequences are located from nt 247 through nt 6688 inclusive; the remaining sequences are from the pT7T3 18U vector.
b) Construction of pTHBVT and pTHBVT-d
An HBVtat recombinant was initially constructed by insertion of the HIV-1 tat gene into the unique BstEII site in the tether region and in-frame with the pol ORF; this recombinant is contained on the plasmid pTHBVT which is shown schematically in FIG. 1A. In FIG. 1, all the ORFs encoded on the EcoRI-EcoRI monomer of the HBV genome (3221 bp) are shown with the positions of all initiation codons according to the adw2 subtype. The ORFs start from the blunt end and stop at the arrow end. The four domains of the pol gene corresponding to the functional activities are indicated [Faruqi et al. (1991) Virol. 183:764 and Robinson (1990) in Hepadnaviridae and their replication, Fields et al. eds., Fields Virology, Raven Press, Ltd. N.Y.] The solid vertical bar represents the preS1 promoter which is located 39 bp upstream of the tat insertion; the transcription initiation site of the preS1 RNA (2.4 kb) is indicated by an arrow. The NcoI site at the initiation codon of the X gene and the BspEI site downstream of the initiation codon of the pol gene are also shown. The following abbreviations are used in FIG. 1: "RT/Pol," reverse transcriptase and DNA polymerase; "TP," terminal protein.
To construct pTHBVT, a 267-base pair (bp) HIV-1 tat cDNA fragment with additional BstEII sites at both ends was amplified from plasmid pCEP-tat [Robinson et al. (1995) Gene Therapy 2:269] by PCR using the upstream primer 5'-TGCGGGTCACCAATGGAGCCAGTAGATCCTAAT-3' (SEQ ID NO:3) and the downstream primer 5'-ATATGGTGACCCTTCCGTGGGCCCTGTCGGGTC-3' (SEQ ID NO:4) (the BstEII sites are underlined in each primer). The PCR was conducted using Pfu DNA polymerase (Stratagene), a DNA polymerase capable of proof-reading, was used to minimize the error rate of the polymerase. The PCR tat fragment was subcloned into the unique BstEII site in the pol ORF of the HBV genome contained within pTHBV. The resulting construct was designated pTHBVT. DNA sequencing was performed to confirm the presence of the expected sequence. The DNA sequence of pTHBVT is listed in SEQ ID NO:5. In SEQ ID NO:5, the HBV sequences are located from nt 247 through nt 3069 and 3337 through 3734; the tat sequences are located from nt 3070 through 3336; the remaining sequences are from the pT7T318U vector. The recombinant virus contained within pHBVT is referred to as HBVtat.
The tat insert present in pTHBVT contains the entire tat ORF with its own initiation codon but without a stop codon. This insertion was located 39 bp downstream from the preS1 promoter and did not interfere with the ORFs of the HBV structural genes.
A replication competent plasmid for the HBVtat virus was constructed by ligation of two head-to-tail copies of the HBVtat (EcoRI-EcoRI) sequence into the pT7T318U vector. The resulting plasmid was termed pTHBVT-d. The DNA sequence of pTHBVT-d is listed in SEQ ID NO:6. In SEQ ID NO:6, the HBV sequences are located from nt 247 through nt 3069, 3337 through 6557 and 6825 through 7222, ; the tat sequences are located from nt 3070 through 3336 and nt 6558 through 6824; the remaining sequences are from the pT7T318U vector.
FIG. 1B provides a schematic of pTHBVT-d. Expression of the HBV genes and the tat gene from this replicative plasmid (i.e., pTHBVT-d) was controlled by the HBV promoters. This dimeric construct was used to study the functions and characteristics of HBVtat.
In FIG. 1B, the linear map of the HBVtat replication competent plasmid (pTHBVT-d) (9859 bp) with two EcoRI-EcoRI monomers in a head to tail tandem configuration subcloned into the pT7T318U vector is shown. All ORFs are depicted by solid bars. The locations of the tat insertion are indicated by hatched boxes (diagonal hatch marks). The following abbreviations are used in FIG. 1B: "T3," T3 promoter; "T7," T7 promoter; "AmpR," ampicillin resistance. The arrowheads above T3 and T7 indicate the direction of transcription from these promoters.
c) Other Constructs
The plasmid pLTR-CAT [referred to as U3-R-CAT in Chang, L. -J. et al., J. Virol. 76:743 (1993)] is a reporter plasmid which contains the HIV-1 LTR directing the expression of the CAT gene.
The plasmid pCEP-tat contains the CMV-IE promoter directing the expression of the tat gene [Chang, L. -J. et al., J. Virol. 76:743 (1993)]. pCEP-tat was constructed as follows. pSP72tat (described below) was digested with XhoI and BamHI to isolate the tat gene. This XhoI/BamHI fragment was then inserted into either the eucaryotic expression vector pCEP4 (Invitrogen) to generate pCEP-tat. Pfu polymerase (Stratagene) was used in place of Taq DNA polymerase in the PCR because of its lower error rate. PCR conditions were as described above.
pSP72tat was made by cloning the tat gene into pSP72 (Promega). The tat gene was isolated using PCR from the plasmid pSV-tat [Peterlin, B. M. et al. Proc. Natl. Acad. Sci. USA 83:9734 (1986)]. The primers used to amplify the tat gene were 5'-AAGGATCCTCG AGCCACCATGGAGCCAGTAGATCCT-3' (SEQ ID NO:7) and 5'-CAAGATCTGCA TGCTAATCGAACGGATC TGTC-3' (SEQ ID NO:8). Reaction conditions were as described [Chang, L. -J. et al. (1993) J. Virol. 67:743]. Briefly, Pfu polymerase (Stratagene) was used according to the manufacturer's instructions in a 50 μl reaction containing 0.5 μg of each primer, 0.01 μg of pSVtat [Peterlin, B. M. et al. (1986) Proc. Natl. Acad. Sci. USA 83:9734] for 30 cycles under the following conditions: step 1: 94° C. for 5 min; step 2: 50° C. for 1 min; step 3: 72° C. for 1 min; step 4: 92° C. for 1 min and step 5: repeat steps 2-4 for 30 cycles. Pfu DNA polymerase (Stratagene) was used in the PCR. The tat gene was recovered from the PCR products by digestion with BamHI and BglII and inserted into pSP72 (Promega) digested with BamHI and BglII to generate pSP72tat.
EXAMPLE 2
Functional Expression of HIV-1 tat by the HBVtat Recombinant Virus
The ability to express a foreign gene inserted into the HBV genome was investigated. The expression of the tat gene of HBVtat was determined by cotransfection of HBVtat and the HIV-1 LTR-CAT reporter plasmid, pLTR-CAT in HepG2 (human liver) and LMH (chicken liver) cells. The functional activity of the tat protein (Tat) was determined through transactivation of HIV-1 LTR using the CAT assay.
a) Tissue Culture and Cotransfection of HepG2 and LMH Cells
Human hepatoblastoma cells (HepG2; ATCC HB 8065) were cultured and maintained at 37° C. in 5% CO 2 in Auto-Pow MEM Eagle (modified) medium (ICN Biomedicals, Inc.) supplemented with 10 mM sodium bicarbonate, 2 mM L-glutamine, 10% fetal bovine serum, 50 units/ml penicillin G sodium, 0.01 mg/ml streptomycin and 50 units/ml nystatin (HepG2 medium). Chicken hepatoma cells [LMH; Condreay et al. (1990) J. Virol. 64:3249] were cultured and maintained at 37° C. in 5% CO 2 in a mixture of 1:1 Auto-Pow MEM Eagle (modified) (ICN Biomedicals, Inc.) and F12 (ICN Biomedicals, Inc.) media with the same supplementation as above for the HepG2 medium.
Transfection of HepG2 and LMH cells were performed in 60-mm tissue culture dishes by the Lipofectin procedure (GIBCO BRL, Life Technologies) as recommended by the manufacturer. A 1:6 ratio of DNA:Lipofectin was used for HepG2 transfection whereas a 1:3 ratio was used for LMH transfection. In brief, HepG2 or LMH cells were subcultured 20 hr prior to transfection. Cells were fed with fresh media 1 hr before transfection. The plasmid DNA and Lipofectin were each diluted into 300 μl of unsupplemented medium. These two solutions were combined, incubated for 30 min at room temperature, and then applied to cells that had been washed twice with the unsupplemented medium. The transfected cells were incubated at 37° C. in 5% CO 2 . Four hours after transfection, an equal volume of the appropriate medium plus 10% fetal bovine serum (no supplementation with antibacterial agents) was added with further incubation. At 20 hr after transfection, the culture medium was changed to supplemented HepG2 or LMH medium.
For the CAT assay, a total amount of 5 μg of DNA per 60 mm tissue culture dish was used. HepG2 or LMH cells were transfected with the CAT reporter plasmid (pLTR-CAT) in the presence or absence of HBV plasmids or pCEP-tat.
The expression of HBV genes was assayed in HepG2 cells and a total amount of 10 μg of DNA per 60 mm tissue culture dish was used for transfection. Complementation of the hepatitis B surface antigens (HBsAg) was studied by cotransfecting an equimolar ratio of a plasmid producing HBsAg (pSV-45) with the HBVtat plasmid.
To assess transfection efficiency, all transfections were performed in the presence of human growth hormone plasmid pXGH5 (Nichols Institute Diagnostics). Each transfection included 0.1 μg of the pXGH5 plasmid which allows the transfected cells to express human growth hormone into the culture supernatant. Secreted human growth hormone was quantitated by radioimmunoassay using the commercially available kit provided by Nichols Institute Diagnostics. For preliminary detection and normalization of the expression of HBV genes, hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) secreted in the cell media were determined by a Microparticle Enzyme Immunoassay (MEIA) (Abbott Laboratories).
b) CAT Assay
CAT assays were performed as described [Chang, L. -J. et al., (1993) J. Virol. 76:743]. Briefly, the transfected cells were harvested 48-72 hr after the addition of the DNA and cell lysates were prepared as follows. The cells were washed three times in PBS and subjected to three cycles of freeze-thawing in a 37° C. water bath and a dry-ice ethanol bath. The protein concentration in the cell lysates was determined by using a DC protein assay kit (BioRad). To obtain results within the linear kinetic range of CAT activity, the amount of cell lysate used in each reaction was adjusted to give a detectable signal within 1 hr and less than 60% consumption of the input substrate [ 14 C]chloramphenicol (0.5 μCi; 55 mCi/mmol; ICN). The enzyme concentration was determined by a serial dilution for lysates with high levels of CAT activity.
Following the incubation of the cell lysate and the substrate, the reaction products were spotted onto a TLC plate and chromatographed in a solution containing 95% chloroform and 5% methanol for 45 min. The plates were allowed to dry and then were autoradiographed by exposing the plates to photographic film for 12 hr at room temperature. The amount of chloramphenicol present in acetylated or non-acetylated forms was quantitated by exposing the TLC plates to an imaging plate for 2 hr and scanning with a phosphoimager (Model BAS 1000, Fuji Medical Systems, USA Inc.). The relative level of CAT enzyme was determined after normalization for transfection efficiency and total quantity of protein in each cell lysate.
c) Expression of HIV-1 tat in Cells Transfected With HBVtat
The expression of the tat gene of HBVtat was determined by cotransfection of HBVtat and the HIV-1 LTR-CAT reporter plasmid in HepG2 (human liver) and LMH (chicken liver) cells. The functional activity of the tat protein (Tat) was determined through transactivation of HIV-1 LTR using the CAT assay. A representative autoradiogram of a CAT assay performed on cell lysates prepared from cotransfected cells is shown in FIG. 2.
In FIG. 2, lane 1 shows CAT activity in HepG2 cells transfected with pCEP-tat (positive control); lane 2 shows CAT activity in mock-transfected HepG2 cells (negative control; cells were cotransfected with pT7T318U and pLTR-CAT); lane 3 shows CAT activity in HepG2 cells cotransfected with pLTR-CAT and pTHBV-d ("wt", wild-type HBV); lane 4 shows CAT activity in HepG2 cells cotransfected with pLTR-CAT and pTHBVT-d (HBVtat) and lane 5 shows CAT activity in HepG2 cells cotransfected with pLTR-CAT and pTHBVTX - -d (X - mutant of HBVtat; described in section d, below). The activity of the CAT enzyme expressed was determined 48 hr post-transfection. Relative levels of the CAT expression (normalized to an internal control human growth hormone) are shown as % product converted with standard deviations. The negative control represents the basal activity of the unactivated HIV-1 LTR. Elevated levels of the CAT enzyme activity reflect transactivation of HIV-1 LTR. The following abbreviation are used in FIG. 2: "AcCm," acetylated chloramphenicol; "Cm," unacetylated chloramphenicol.
The results shown in FIG. 2 demonstrate that in HepG2 cells, the basal activity of the CAT enzyme expressed from the HIV-1 LTR-CAT plasmid in the absence of Tat was low (FIG. 2, lane 2). However, when HBVtat was present, HIV-1 LTR was activated to a level similar to that activated by the Tat positive control (FIG. 2, lane 4 vs lane 1). These results illustrate the expression of functional Tat by the HBVtat recombinant.
The tat gene was also expressed and functioned in LMH cells but not as well as in HepG2 cells. The transactivation activity of HBVtat in these cells was about 40% of that of the Tat positive control. This suggests that HBV is not expressed as well in the chicken liver cells (LMH) as in the human liver cells (HepG2). Further studies of the HBVtat recombinant, therefore, were performed only in HepG2 cells.
Diminished expression of the tat gene controlled by the endogenous HBV promoter/enhancer elements in chicken hepatoma cells probably reflects the species and cell specificity of hepadnaviruses. It is known that HBV gene expression is regulated by liver specific promoter/enhancer elements [Schaller and Fischer (1991) Curr. Top. Microbiol. Imnuunol. 168:21 and Shaul (1991), Regulation of hepadnavirus transcription, A McLachlan (ed.), in Molecular biology of hepatitis B viruses, CRC Press, Boca Raton, Fla.]. Liver specific factor(s) has been shown to interact with the HBV enhancer [Patel et al. (1989) J. Virol. 63:5293] and to be essential for its activity [Jameel and Siddiqui (1986) Mol. Cell. Biol. 6:710]. Therefore, it is possible that the chicken LMH cells, although hepatocyte cells, may lack particular factor(s) required for regulating efficient expression of HBV genes. Evidence supporting tissue and species specificity of HBV is plentiful. It has been demonstrated that even though the HBV enhancer can function in a cell line derived from rat hepatocytes, the activity is only 30% of that expressed in human hepatoblastoma cells (HepG2) [Patel et al. (1989), supra]. In addition, DHBV replicates more efficiently in chicken hepatoma cells (LMH) than in human liver cells (HuH-7 and HepG2) [condreay et al. (1990) J. Virol. 64:3249].
d) Tat Expression from HBVtat is Responsible for Transactivation of the HIV-1 LTR
Although the wild type HBV transactivated HIV-1 LTR to a lesser extent than did the HBVtat recombinant (FIG. 2, lane 3 vs lane 4), it was still possible that the transactivation function of HBVtat was enhanced by other HBV genes, such as the X gene [Siddiqui et al. (1989) Virol. 169:479 and Twu et al. (1990) Virol. 177:406]. To test this possibility, mutations of the X gene in HBVtat were constructed and used to cotransfect HepG2 cells (along with pLTR-CAT) as follows.
Mutation of the X gene of HBVtat was performed by site-directed PCR mutagenesis. Three oligonucleotide primers were designed. The upstream primer 5'-TTACTAGTGCCATTTGTTCAGTGGTTCG-3' (SEQ ID NO:9) was homologous to the sequence at the unique SpeI site (underlined) located 142 bp upstream of the X gene. The downstream primer 5'-GTGCACACGGACCGGCAGATG-3' (SEQ ID NO:10) anneals to the sequence at the unique RsrII site (underlined) located 197 bp downstream of the X gene. The mutagenic primer 5'-ATACATCGTTTCCcTGGCTGCTAGGCTGTACTGCtAACTGGATCCTTC-3' (SEQ ID NO:11 was targeted to the sequence at the unique NcoI site (underlined) at the initiation codon of the X gene with change from A to C at the 1376 nucleotide (nt) and from C to T at the 1397 nt (nt numbering according to sequence of the HBV genome as set forth in SEQ ID NO:1). These changes abolished the initiation codon of the X gene and the original NcoI site with addition of a stop codon (mutated nucleotides shown in boldface lower cases). These mutations conserved the pol coding sequences. The mutation was performed by multiple PCR as described [Picard et al. (1994) Nucleic Acids Res. 22:2587]. Briefly, mutagenesis was performed as a one-tube PCR with 3 consecutive steps each comprising 10 amplification cycles. In step 1, the mutagenic primer (SEQ ID NO:11) (10 pmol) and the downstream primer (SEQ ID NO:10) (10 pmol) were used to amplify a megaprimer using pTHBV as the template (3.6 fmol or 15 ng of the plasmid); the 95 μl PCR contained 2.5 units Pfu DNA polymerase, 0.2 mM all four dNTPs, 20 mM Tris-Cl, pH 8.75, 10 mM KCl, 10 mM (NH 4 ) 2 SO 4 , 2 mM MgSO 4 , 0.1% Triton X-100 and 0.1 g/l BSA. The enzyme was added last and the reaction was overlaid with mineral oil. The reaction was started by incubation at 95° C. for 3 min. Ten amplification cycles consisting of 94° C., 1 min; 56° C., 1 min.; 72° C., 2 min. were performed followed by 5 min. at 72° C.; the reaction was then held at 4° C. In step 2, the upstream primer (SEQ ID NO:9) (50 pmol) was added to the above reaction to permit the synthesis of the mutated X gene using 10 amplification cycles as described above. In step 3, additional downstream primer (SEQ ID NO:10) (50 pmol) was added to permit further DNA amplification using 10 amplification cycles as described above.
The PCR fragment containing the mutated X gene sequences was then cut with SpeI and RsrII and cloned into the unique sites in the HBVtat plasmid. The resulting plasmid was termed pTHBVTX - ; the sequence of pTHBVTX - is provided in SEQ ID NO:12. In SEQ ID NO:12, the HBV sequences are located from nt 247 through nt 3069 and 3337 through 3734; the tat sequences are located from nt 3070 through 3336; the remaining sequences are from the pT7T318U vector.
HepG2 cells were cotransfected with pLTR-CAT (CAT reporter plasmid) and pTHBVTX - (X - mutant of HBVtat) and CAT assays were performed on cell lysates as described above. FIG. 2, lane 5 shows a representative CAT assay from cells cotransfected with pLTR-CAT and pTHBVTX - . As shown in FIG. 2, the X - mutant of HBVtat (HBVtatX - ) showed a only small reduction in the transactivation activity compared with that of the original HBVtat construct (FIG. 2, lane 5 vs lane 4). These results thus demonstrate that the major transactivation activity (86%) of HBVtat was accounted for by the tat insertion.
e) HBV Core, Pol and Surface Gene Products do not Transactivate the HIV-LTR
To see if HBV genes other than the X gene also contributed to the transactivation function, transient expression and the CAT assay of individual HBV genes were performed in HepG2 cells. Plasmids containing the core (pCHBVC), pol (pCHBVP), HBsAg (PSV-45), X (pSG-X) genes were obtained or constructed as follows.
To construct the HBV core expression plasmid, pCHBVC, a 1,500 nt fragment from the NlaIII site to the unique AvrII site which includes the entire sequence of the core gene was PCR-amplified from the HBV genome-containing plasmid, pKSVHBV1 [Seifer et al. (1990) Virol. 179:300] and cloned into the pTZ19R vector (Pharmacia). The sequence between the HindIII and XbaI sites containing the core gene was subcloned into the eukaryotic expression vector pcDNA-I/amp (Invitrogen) to generate pCHBVC.
The HBV pol plasmid (pCHBVP) was constructed by subcloning a 2,734 nt fragment containing the entire pol ORF from pKSVHBV1 into the pTZ19R vector by multiple cloning steps using restriction enzymes and PCR. The sequence coding for the entire HBV pol ORF was cut and subcloned into the HindIII/EcoRV sites of the eukaryotic expression vector pcDNAI/amp. The subcloned sequences of these recombinant plasmids were verified by restriction mapping and DNA sequencing. The sequence of pCHBVP is provided in SEQ ID NO:13. In SEQ ID NO:13, the pol ORF begins at nt 3095 and ends at nt 5632.
pSG-X was constructed by inserting the X gene contained within a ˜600 bp NcoRI-BglII fragment together with a 113 bp EcoRI-NcoI fragment from the hygromycin gene [this fragment served as a stuffer fragment and may be obtained from the pCEP4 vector (Invitrogen)] into the EcoRI/BglII sites of the eukaryotic expression vector pSG5 (Stratagene).
The pSV45H plasmid carries the entire HBV surface antigen ORFs for the simultaneous expression of L, M and S surface proteins (i.e., the preS1, preS2 and S sequences) [Persing et al. (1986) Science 234:1388]. Expression of the surface antigen ORFs in pSV45H is under the transcriptional control of the SV40 promoter (i.e., a 342 bp PvuII-HindIII fragment of SV40). pSV45H was constructed as described by Persing et al., supra. Briefly, the unique BstEII site within the HBV genome (adw991 subtype) was converted into a BglII site by the addition of a BglII linker. The resulting genome was then digested with BglII and the 2.3 kb BglII fragment containing the entire preS region and the HBV polyadenylation signal (within the core gene) was inserted into pSV65 digested with BamHI. pSV65 contains 342 bp PvuII-HindIII fragment of SV40 (the promoter region) inserted into pSP65 (Promega).
Each of the above plasmids expressing a single HBV gene were cotransfected with pLTR-CAT into HepG2 cells as described above. Cell lysates were prepared and CAT assays were conducted as described above. A representative autoradiograph is shown in FIG. 3. In FIG. 3, lanes 1-7 contain extracts from HepG2 cells cotransfected with pLTR-CAT and either pTHBV-d ("wt," wild-type HBV), pCHBVC ("core"), pCHBVP ("pol"), pSV45H ("HBsAg"), pSG-X ("X"), pCEP-tat ("+," positive control) or pT7T318U ("-," negative control). Relative levels of the CAT expression (normalized to an internal control human growth hormone) are shown as % product converted with standard deviations. The following abbreviation are used in FIG. 3: "AcCm," acetylated chloramphenicol; "Cm," unacetylated chloramphenicol.
The results shown in FIG. 3 indicate that the level of the transactivation of the X gene was as high as that of the wild type HBV, whereas the transactivation activities of the core, pol or surface genes were insignificant.
EXAMPLE 3
Expression of the tat Gene in HBVTat is Controlled by the preS1 Promoter
Although the tat insert was designed to be expressed as a pol-Tat fusion recombinant using the core/pol promoter, the tat ORF was also proximal to the preS1 promoter (FIG. 1A). It was thus possible that the tat gene might be expressed by the preS1 promoter. To determine which promoter was used for the expression of the tat gene in HBVtat, a frameshift mutation was generated near the beginning of the pol gene in HBVtat as follows.
A frameshift mutation of the pol ORF of HBVtat was generated by digesting pTHBVT with BspEI site (a unique site located at position 2331 nt of the HBV genome) downstream of the initiation codon of the pol gene and subsequently filling in (2332 to 2336 nt) with Klenow Fragment (GIBCO BRL, Life Technologies). The resulting plasmid was termed pTHBVTP - . The DNA sequence of pTHBVTP - is provided in SEQ ID NO:14. In SEQ ID NO:14, the HBV sequences are located from nt 247 through nt 3073 and 3341 through 3737; the tat sequences are located from nt 3074 through 3340; the remaining sequences are from the pT7T318U vector.
pTHBVTP - is shown schematically in FIG. 1C. A plasmid containing a head to tail dimer of the HBV genome present in pTHBVTP - was generated as described in Example 1 (i.e., an EcoRI-EcoRI dimer) and the resulting plasmid was termed pTHBVTP - -d and the virus produced by this construct is referred to as HBVtatP - .
FIG. 1C (b) diagrams the mutation present in pTHBVTP - . The dotted lines indicate the frameshift mutation in the pol ORF by digestion of the BspEI site and filling in at 2332 to 2336 nt. The inserted nucleotides are shown as boldface letters.
The mutation present in pTHBVTP - disrupted the reading frame of the pol gene. It, therefore, ablated the expression of the tat insert as a pol-Tat fusion recombinant. These mutated sites were verified by restriction mapping and DNA sequencing. The pTHBVTP - -d and pLTR-CAT plasmids were cotransfected into HepG2 cells to examine the effect of the frameshift mutation in the pol ORF. Cotransfections were conducted as described in Example 2. A representative autoradiograph of CAT assays run using cell lysates from cotransfected HepG2 cells is shown in FIG. 4.
In FIG. 4, lanes 1 and 2 depict CAT activity present in cells cotransfected with pLTR-CAT and pTHBVT-d (HBVtat) or pTHBVTP - -d (HBVtatP - ), respectively. Lanes 3 and 4 depict CAT activity from cells transfected with pCEP-tat ("+," positive control) and pT7T318U ("-," negative control), respectively. Relative levels of the CAT expression (normalized to an internal control human growth hormone) are shown as % product converted with standard deviations. The following abbreviation are used in FIG. 4: "AcCm," acetylated chloramphenicol; "Cm," unacetylated chloramphenicol.
The frameshift mutation present in HBVtatP - disrupted the translation of the pol ORF, thus abolishing the expression of the tat gene as a pol-Tat fusion recombinant. Transient expression in HepG2 cells and the CAT assay showed that the pol frameshift mutant of HBVtat (i e., HBVtatP - ) exhibited a transactivation function similar to that of the original HBVtat construct (FIG. 4, lane 1 vs lane 2). This result indicated that although the tat gene was in-frame with the pol ORF, the transactivation function of HBVtat was not dependent on the expression of the pol-Tat fusion recombinant. It also suggested that the expression of functional Tat was likely controlled by other mechanisms, such as the use of the preS1 promoter or internal translation initiation.
To determine whether the tat gene was expressed by the preS1 promoter, a Northern blot analysis of RNA expressed from HBVtat was performed. It was expected that the pregenomic RNA for HBVtat expressed by the core/pol promoter should be about 270 bases longer than that expressed from the wild type HBV in accordance with the size of the tat insertion. If a tat transcript was expressed by the preS1 promoter, the size of this subgenomic RNA should also be increased by about 270 bases. The sizes of the preS2/S and the X messages for the HBVtat construct would expected to be the same as those for the wild type HBV.
HepG2 cells were transfected with wild-type HBV (pTHBV-d), HBVtat (pTHBVT-d), pCEP-tat (positive control) and pT7T318U (negative control) as described in Example 2; a total of 10 μg of DNA per 60 mm tissue culture dish was used per transfection. Total RNA was isolated from the transfected cells 72 hours after transfection using TRIzol™ reagent (GIBCO BRL, Life Technologies) as described by the manufacturer. The amount of total RNA was determined by spectrophotometry. An equal amount of RNA for each sample was separated on a 1.2% agarose-0.22M formaldehyde gel as described [Tsang et al. (1993) BioTechniques 14:380]. The RNA was transferred to a Hybond-N membrane (Amersham) and hybridized with a 32 P-HBV DNA probe. The same blot was stripped by washing in a boiling 0.5% SDS solution as described by the membrane manufacturer and rehybridized with a 32 P-tat DNA probe using standard methods [Sambrook et al. (1989) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.]. The resulting autoradiographs are shown in FIG. 5.
In FIG. 5, total RNA from HepG2 cells transfected with wild type HBV (lane 1, "wt"), HBVtat (lane 2), pCEP-tat as a positive control for the tat gene expression (lane 3, "tat(+)") and pT7T318U as a negative control (lane 4, "mock") was fractionated, transferred and hybridized with either the 32 P-HBV DNA probe (FIG. 5A) or the 32 P-tat DNA probe (FIG. 5B). Sizes of the transcripts expressed from the cells transfected with wild type HBV and HBVtat that contain the HBV sequences are shown on the left and right, respectively.
The Northern blot (FIG. 5) showed that five species of RNA expressed from HBVtat, 3.70, 3.10, 2.65, 2.00 and 0.80 kb in length, were detected using the HBV probe (FIG. 5A, lane 2) and four species of RNA, 3.50, 2.40, 2.05 and 0.80 kb in length, were detected from the wild type HBV (FIG. 5A, lane 1). Only three species of the RNA transcripts expressed from HBVtat, 3.70, 3.10 and 2.65 kb in length, were detected by the tat probe (FIG. 5B, lane 2). These results indicated that the tat insert was expressed by the core/pol promoter and by the preS1 promoter since the pregenomic RNA (3.70 kb) and the subgenomic RNA (2.65 kb) for HBVtat were about 250 bases larger than expected for the wild type HBV. It appears that the tat gene was also expressed in another RNA species of about 3.10 kb in length. Because of its size, it is presumed that this tat transcript may be derived from the pregenomic RNA.
Taken together, these data demonstrate that the expression of functional Tat from HBVtat is controlled by the preS1 promoter. The above data also demonstrated that the tat gene inserted in the tether region is expressed by two promoters: the core/pol promoter and the preS1 promoter. Since the pol-Tat fusion recombinant expressed by the core/pol promoter is not responsible for the transactivation activity of HBVtat, the functional Tat appears to be expressed by the preS1 promoter as a Tat-pol fusion product. It is known that the tat protein functions in the nucleus and that the pol protein interacts with the 5'epsilon sequence of the pregenomic RNA and is encapsidated into core particles in the cytoplasm [Hirsch et al. (1991) J. Virol. 65:3309 and Junker-Neipmann et al. (1990) EMBO J. 9:3389]. While not limiting the present invention to any particular mechanism, it is conceivable that the pol-Tat fusion protein is encapsidated into core particles in the cytoplasm and thus is not transported into the nucleus where the tat protein would function. The data presented above showing that the pol-Tat fusion protein does not contribute to the Tat function is consistent with this hypothesis. Since the entire sequence of the pol protein is required for the encapsidation and packaging of cytoplasmic viral core particles [Bartenschlager et al. (1990) J. Virol. 64:5324 and Hirsch et al. (1990) Nature 344:552], the Tat-pol fusion recombinant lacking the terminal protein domain of pol would not be incorporated into core particles. Therefore, this Tat form may migrate to the nucleus. The above data support the conclusion that the functional Tat-pol fusion recombinant is expressed by the preS1 promoter because a RNA transcript of increased size relative to the preS1 RNA and attributable to the tat insertion has been detected. Alternatively, expression of this fusion protein by internal initiation at the tat initiation codon in the pregenomic RNA is also possible.
As shown above, the tat gene of HBVtat is also expressed as a 3.1 kb RNA and this RNA species is not detected from the expression of wild type HBV. The insertion of the tat gene into the HBV genome possibly induces the formation of this RNA species. In accordance with its size, this tat RNA species possibly originates from the pregenomic RNA. Since RNA splicing has been reported in hepadnaviruses [Hantz et al. (1992) Virol. 190:193; Obert et al. (1996) EMBO J. 15:2565; and Wu et al. (1991) J. Virol. 65:1680] and sequence analysis of HBVtat reveals consensus splice donor sites on the HBV genome flanking the tat insert and a consensus splice acceptor site and a branch point within the tat sequence. While not limiting the present invention to any particular mechanism, it is thought that this tat transcript is derived from splicing of the pregenomic RNA of the HBVtat recombinant.
Regardless of the exact mechanism by which Tat is produced in the recombinant HBV, the above data demonstrate for the first time the ability to express foreign gene sequences in the context of the HBV genome.
EXAMPLE 4
HBV Genome With HIV-1 tat Insertion Retains Endogenous Polymerase Activity
To examine the effect of the tat insertion in the HBV genome on viral gene expression and function, HBVtat was transiently expressed in HepG2 cells. The viral DNA polymerase activity was examined by endogenous polymerase assay and the ability to incorporate radioactively-labeled deoxynucleotides into the viral genome by core-associated DNA polymerase was examined. In addition, cytoplasmic lysates and culture media containing intracellular core and extracellular viral particles, respectively, were harvested from HepG2 cells transfected with wild type HBV or HBVtat and examined for the presence of relaxed circular and linear double stranded viral genome and single stranded DNA.
a) Transfection of HepG2 Cells and Endogenous Polymerase Assay of HBVtat
HepG2 cells were transfected with wild-type HBV (pTHBV-d), HBVtat (pTHBVT-d), a mock control (pT7T318U); transfections were conducted as described in Example 2. HepG2 cells were also cotransfected with either wild-type HBV or HBVtat and the HBsAg plasmid, pSV45H. For the cotransfections, an equimolar ration of the pSV45H and HBVtat plasmids were used (total amount of DNA was 10 μg/60 mm dish). Transfection efficiency was assessed by performing all transfections in the presence of pXGH5 (human growth hormone plasmid) and secreted growth hormone was quantitated by radioimmunoassay as described in Example 2. For preliminary detection and normalization of the expression of HBV genes, hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) secreted in the cell media were determined by MEIA (Abbott Laboratories).
i) Isolation of Extracellular HBV Particles
Four to five days after transfection, the culture media from transfected cells were collected and centrifuged in a Sorvall RT6000B Refrigerated Centrifuge (Dupont) at 5,000 rpm for 10 min to remove cellular debris. The extracellular viral particles were pelleted over a 25% sucrose cushion in 50 mM Tris (pH 8.0), 150 mM NaCl and 10 mM EDTA solution using an ultracentrifuge SW 41 rotor (Beckman) at 30,000 rpm for 7 to 20 hr. The pellets were resuspended in 50 mM Tris (pH 7.5), 150 mM NaCl and 10 mM EDTA. To remove DNA not present in virus particles, 6 mM MgCl 2 and 100 μg/ml of DNase I were added to the suspension with incubation at 37° C. for 30 min. The virus particles were precipitated by addition of one-third volume of 26% PEG 8000, 1.4M NaCl, and 25 mM EDTA. After centrifugation, the pellets were suspended in the following solutions as appropriate. For endogenous polymerase assay, the pellets were suspended in 30 μl of polymerase buffer (50 mM Tris pH 8.0, 40 mM MgCl 2 , 50 mM NaCl, 1% Nonidet P-40 and 0.3% β-mercaptoethanol). The pellets were suspended in 50 mM Tris (pH 7.5), 150 mM NaCl and 10 mM EDTA for DNA extraction and southern blot analysis.
ii) Isolation of Intracellular HBV Core Particles
Transfected HepG2 cells in 60 mm tissue culture dishes were lysed by addition of lysis buffer (10 mM Tris-HCl [pH 7.5], 50 mM NaCl, 1 mM EDTA, 0.25% Nonidet P-40, and 8% sucrose) and incubated for 2-5 min at room temperature. The cell lysate was collected and subjected to microcentrifugation to remove nuclei and cellular debris. To eliminate transfected plasmids and cytoplasmic RNA, the lysate was incubated with 6 mM MgCl 2 , 100 μg/ml of DNase I, and 10 μg/ml of RNase A at 37° C. for 30 min. The viral core particles were precipitated by addition of one-third volume of 26% PEG 8000, 1.4M NaCl, and 25 mM EDTA followed by centrifugation. The pellets were then suspended in appropriate solutions as described above.
iii) Endogenous Polymerase Assay
Viral materials pelleted from culture media or cell lysates were suspended in 30 μl polymerase buffer. To the mixture, were added 11 μM of each of dATP, dGTP, and dTTP and 10 μCi of [α- 32 P] dCTP (3,000 Ci/mmol; Amersham). The reaction was performed at 37° C. for 1 hr. Chase buffer containing 0.2 mM unlabeled dCTP, and 0.1 mM of each of dATP, dGTP, and dTTP were then added with further incubation for 30 min. The reaction was stopped by addition of sodium dodecyl sulfate (SDS) and proteinase K to final concentrations of 1% and 1 μg/μl, respectively, and incubated at 37° C. for at least 2 hr. The 32 P-labeled viral DNA was isolated by phenol-chloroform extraction and ethanol precipitation. The labeled viral DNA was then electrophoresed through a 1.2% agarose gel. The 32 P-labeled viral DNA was then transferred to a nylon membrane and analyzed by autoradiography. The relative level of the endogenous polymerase activity was analyzed using a phosphoimager.
b) Extraction of Viral DNA and Southern Blot Analysis
Viral materials pelleted from culture media or cell lysates were suspended in 50 mM Tris (pH 7.5), 150 mM NaCl and 10 mM EDTA. Nucleic acids were then purified by proteinase K digestion and phenol-chloroform extraction, and collected by ethanol precipitation. Viral DNA was assayed by agarose gel electrophoresis and Southern blot analysis using standard methods (Sambrook et al., supra).
The results of the endogenous polymerase assay conducted using extracellular HBV particles collected from HepG2 cells transfected with HBVtat demonstrated that radioactively-labeled deoxynucleotides could be incorporated into the viral genome by core-associated DNA polymerase. Cytoplasmic lysates and culture media containing intracellular core and extracellular viral particles, respectively, were harvested from HepG2 cells transfected with wild type HBV or HBVtat. The samples were normalized to the internal transfection control (secreted human growth hormone) and to the amounts of HBsAg and HBeAg secreted into the culture media. The reaction products were separated on 1.0% agarose gels and detected by autoradiography as shown in FIG. 6A.
For the results shown in FIG. 6A, the viral core particles and cell-free particles were isolated from the transfected HepG2 cells and the culture media, respectively, 4-5 days post-transfection. Approximately equal amounts of core particles and extracellular viral particles were used after normalizing to an internal control human growth hormone secreted and to quantities of HBsAg and HBeAg produced. FIG. 6A shows the endogenous polymerase activities in intracellular core particles (lanes 1-3) and in extracellular viral particles (lanes 4-6) of HBVtat compared with wild type HBV. Lane 2 and lane 5, HBVtat; Lane 1 and lane 4, wild type HBV; Lane 3 and lane 6, mock transfection.
As shown in FIG. 6A, labeled DNA bands, corresponding to relaxed circular and linear double stranded viral genome and single stranded DNA, were detected, albeit at reduced levels, as a result of the DNA polymerase activity of HBVtat (FIG. 6A, lane 2 and 5), thus indicating that HBV with the tat insert (HBVtat) retained the polymerase function. The average level of endogenous polymerase activity in the intracellular core particles of HBVtat measured by phosphoimager was about 15% of that of wild type HBV and that in the extracellular viral particles of HBVtat was about 8% of that of wild type HBV. Southern blot analysis of the DNA isolated from the intracellular core and extracellular viral particles of HBVtat confirmed these results. Thus, the insertion of the 267 bp tat gene within the tether region of the pol gene reduced but did not abolish the polymerase function.
Previous studies have established that the L protein is absolutely required for the formation and secretion of HBV free virus particles [Bruss and Ganem (1991) Proc. Natl. Acad. Sci. USA 88:1059 and Sheu and Lo (1995) Gene 160:179]. While not limiting the present invention to any particular mechanism, a possible cause of the marked reduction in the endogenous polymerase activity of cell-free HBVtat particles may be, therefore, interference with expression of the L protein, because the insertion between the initiation codon and the promoter of preS1 gene might interrupt the expression of the L protein. To test this possibility, HepG2 cells were cotransfected with HBVtat and a plasmid carrying the entire HBsAg gene (pSV45H) to complement the HBsAg in trans. HepG2 cells were also cotransfected with the wild-type HBV and pSV45H. The extracellular viral particles were isolated from the cotransfected cultures and tested for endogenous polymerase activity as described above. A representative result of this analysis is shown in FIG. 6B.
FIG. 6B shows the endogenous polymerase activity of HBVtat complemented with HBsAg (L, M and S). An equal molar ratio of HBVtat and the HBsAg plasmid were cotransfected and transiently expressed in HepG2 cells as described above. The extracellular viral particles were harvested and analyzed for the endogenous polymerase activity. Lane 2, HBVtat complemented with HBsAg; Lane 1, wild type HBV complemented with HBsAg. RC, relaxed circular; L, linear; SS, single stranded.
As seen in FIG. 6B, complementation of HBsAg did not seem to improve the endogenous polymerase activity of HBVtat. The ratio of the endogenous polymerase activities of the trans-complemented HBVtat to those of the wild type HBV was as high as the ratio without L complementation. These results suggest that the reduction in the HBVtat polymerase activity was not due to a reduction in the L protein synthesis.
The results presented above demonstrate that insertion of the tat gene in-frame with the pol gene reduces the endogenous polymerase activity of the pol protein. The reduction of the endogenous polymerase activity in the extracellular free virus particles was greater than that detected in the intracellular core particles. This suggested that the tat insertion might interfere with the L protein synthesis and thus affect the secretion of the free virus particles. The HBsAg complementation experiment described above, however, did not support this hypothesis; that is, the complementation did not increase the endogenous polymerase activity in the recombinant cell-free viral particles. While not limiting the present invention to any particular theory, it is possible that insertion of the foreign gene in-frame with the pol gene has a direct effect on the function of the polymerase enzyme. The insertion may influence the structural conformation of the pol protein and thus result in a reduced enzymatic activity. Attempted trans-complementation with wild-type pol protein did not show significant increase in the endogenous polymerase activity of HBVtat. This was not unexpected since it is known that the pol protein acts primarily in cis for encapsidation and packaging of pregenomic RNA; that is, pregenomic RNAs from which the pol protein is synthesized are preferentially encapsidated [Bartenschlager et al. (1990), supra and Hirsch et al. (1990), supra].
EXAMPLE 5
The Insertion of tat has no Significant Effect on the Expression of other HBV Genes
Similar levels of HBeAg and HBsAg were detected in the culture media of cells transfected with HBVtat and wild type HBV at the same transfection efficiency (Table 1). For the results shown in Table 1, HepG2 cells were transfected and HBsAg and HBeAg secreted into the culture medium was quantitated using the MEIA assay as described in Example 4. Furthermore, the detection of endogenous polymerase activity of the extracellular viral particles of HBVtat indicated that HBVtat could form complete virus particles. The insertion of the HIV-1 tat gene into the HBV genome, therefore, does not appear to abrogate the expression of HBV genes or the capability of forming and secreting extracellular virions.
TABLE 1______________________________________Detection Of HBsAg And HBeAg Produced By HepG2 Cells Transfected With Wild Type HBV And HBVtat Amounts (S/N.sup.b ± Standard Deviation)Samples.sup.a HBsAg HBeAg______________________________________wt HBV 56.03 ± 27.35 249.18 ± 65.29 HBVtat 60.06 ± 13.83 226.56 ± 85.76 mock 1.20 ± 0.04 1.18 ± 0.05______________________________________ .sup.a Samples were culture media of HepG2 cells transfected with wildtyp HBV, HBVtat or mock (pT7T318U) and were assayed for HBsAg and HBeAg by MEIA. .sup.b HBsAg and HBeAg produced were determined as S/N values as describe by the manufacturer (Abbott). ≧2.00 S/N is the cut off rate for positive results. According to the manufacturer, ≧7.00 S/N of HBsA detected is equivalent to 4-15 ng/ml concentration but the absolute concentration of HBeAg is not determined.
Based on the amounts of HBsAg and HBeAg produced from HBVtat, expression of other HBV genes does not seem to be affected by the tat insertion. The data presented herein indicates that the HBVtat recombinant can replicate and form viral particles since extracellular viral particles have been harvested and assayed for endogenous polymerase activity as well as for the viral DNA. Detection of the extracellular viral particles also indicates that the expression of the L protein is not affected by the tat insertion because the L protein is absolutely necessary for virion assembly [Bruss and Ganem (1991) Proc. Natl. Acad. Sci. USA 88:1059 and Bruss and Vieluf (1995) J. Virol. 69:6652].
EXAMPLE 6
Construction of HBV Vectors and Insertion of Foreign Genes
The preceding examples demonstrated the ability to express a functional foreign gene product in the context of the HBV genome. To accommodate foreign or heterologous gene sequences up to about 2.0 to 2.2 kb in length, HBV vectors lacking the majority of the pol ORF are constructed. These vectors retain regulatory sequences required for replication, packaging and expression of the inserted foreign gene (i.e., these vectors contain DR1, DR2, the packaging signal, enhancers, the core/pol promoter and the preS1 promoter). Because it has been reported that the HBV X gene is strongly associated with the development of hepatocellular carcinoma [Hohne et al. (1990) EMBO J. 9:1137 and Koike et al. (1989) Mol. Biol. Med. 6:151], the HBV backbone employed in the HBV vectors preferentially lacks the ability to express the X gene product.
a) Construction of a Recombinant HBV Vector Lacking A Functional X Gene
Conveniently, the X- form of HBV in plasmid pTHBVTX - (described in Ex. 2) may be used as a source of an HBV genome lacking a functional X gene. The X mutation present in pTHBVTX - is placed into a HBV genome lacking the tat gene as follows. pTHBVTX - is digested with SpeI and RsrII and the ˜900 bp fragment containing the mutation is inserted into the large fragment obtained by digestion of pTHBV (described in Ex. 1) with SpeI and RsrII to generate pTHBVX - . pTHBVX - is then digested with SphI and the linear pTHBVX - molecule is inserted into the SphI site of pT7T3 18U to generate pTHBVX - /SphI. pTHBVX - /SphI is then digested with BstEII and EcoRV and the ˜4.3 kb fragment containing 1.44 kb of HBV sequences and vectors sequences present between the EcoRI site of HBV is removed. The plasmid, which now lacks the majority of the pol ORF (i.e., sequences located between the BstEII site at nt 2823 and the EcoRV site at nt 1042 of the circular map of HBV), can then be circularized using methods known to the art including the use of synthetic oligonucleotides to provide a polylinker region between the BstEII end and the EcoRV end. As the art well knows an infinite number of suitable polylinker sequences may be employed. The preferred polylinker will contain recognition sites for restriction enzymes which do not cut within either the HBV sequences present on the vector or within the gene of interest to be inserted. It is not required that a polylinker be used to permit insertion of the gene of interest. The gene of interest may be obtained by PCR amplification using primers which allow the insertion of the gene of interest into the BstEII and EcoRV sites present on the open (i.e., not circularized) vector. Once the vector has been circularized (either by insertion of a polylinker followed by insertion of the gene of interest or by insertion of the gene of interest), the vector is digested with SphI and a head to tail dimer containing the HBV sequences and the gene of interest (the dimer is joined at the SphI site) is inserted into pT7T3 18U vector (Pharmacia). The gene of interest may be expressed using endogenous HBV promoters (e.g., preS1 promoter) or alternatively, it may be expressed using a heterologous promoter. If a heterologous promoter is employed, this promoter is joined to the gene of interest in such a manner that the transcription from the heterologous promoter is in the same orientation as that of the HBV promoters (e.g., the preS1 promoter).
The resulting plasmid, pΔHBVX - -d/GOI, retains regulatory HBV sequences required for replication, packaging and expression of the inserted foreign gene (GOI, gene of interest); however, the deleted HBV genome contained on this plasmid is replication-defective (due to an inablity to produce functional pol). In order to produce virus particles containing the replication-defective recombinant HBV genome, the recombinant HBV is cotransfected into cells along with plasmids which encode HBV pol and surface antigen gene products as described below.
b) Packaging of the Recombinant HBV Genome
To encapsidate or package the recombinant HBV genome containing the gene of interest, HepG2 cells are cotransfected with the recombinant HBV construct containing the gene of interest and plasmids containing the HBsAg genes (pSV45H, described in Ex. 2) and the HBV pol gene (pCHBVP, described in Ex. 2) using any suitable transfer protocol (e.g., lipofection as described in Example 2). Four to five days after transfection, the culture medium from the cotransfected HepG2 cells is collected and extracellular recombinant viral particles are collected as described in Example 4.
The presence of infectious recombinant HBV particles is demonstrated by infection of HepG2 cells and examination of the infected cells for the presence and/or expression of the gene of interest. Because HepG2 cells have been reported to be refractory to infection by HBV particles unless the viral particles are first treated with V8 protease, the recombinant HBV particles are treated with V8 protease before they are used to infect HepG2 cells.
c) Protease Treatment of Recombinant HBV Particles
V8 protease treatment is carried according the method of Lu et al. [J. Virol. (1996) 70:2277]. Briefly, recombinant HBV particles are collected as described in Ex. 4 with the exception that the precipitated viral particles are resuspended in 0.05M potassium phosphate buffer (pH 7.4) at a concentration of equivalent to 2×10 9 HBV DNA molecules per ml (HBV DNA may be quantitated using DNA dot blots, a standard technique in the field). The resuspended recombinant HBV particles are then incubated with 1.2 mg V8 protease per ml at 37° C. overnight. Protease is then removed by ultracentrifugation through a 20% sucrose cushion at 36,000 rpm in a SW41 rotor (Beckman) at 10° C. for 8 hr. Recombinant virus particles (i.e., virions) are then resuspended in 150 μl PBS prior to infection of HepG2 cells.
d) Infection of HepG2 Cells With Protease-Treated Recombinant HBV Particles
HepG2 cells are maintained as described in Example 2. Semiconfluent HepG2 cells are washed with HepG2 medium (pH adjusted to 5.5 with MES) and approximately 10 7 virions/ml in HepG2 medium (pH 5.5) are added and the cells are incubated for 12 hr at 37° C. The cells are then washed twice with HepG2 medium (pH 5.5), followed by three washes with PBS and final with a wash using HepG2 medium to remove unabsorbed virus. The cells are then cultured in HepG2 medium.
e) Demonstration of Transfer of Gene Transfer Via Infection With Recombinant HBV Virions
Five to eight days after infection, cells are removed by treatment with trypsin and the presence of intracellular recombinant HBV DNA and/or RNA is demonstrated using standard techniques [e.g., preparation of total DNA followed by Southern blot analysis, lysis of a small aliquot of cells (2,000 to 4,000) in water followed by PCR analysis using primers capable of hybridizing to HBV sequences and/or the gene of interest, preparation of total or polyA+ RNA followed by Northern blot analysis]. The presence of intracellular recombinant HBV vector DNA or RNA produced by the recombinant HBV genome is indicative of infection of HepG2 cells by the recombinant HBV and thus gene transfer by the recombinant HBV virions.
EXAMPLE 7
Construction of Non-Infectious Recombinant HBV Vectors for the Delivery of Genes Without the Need to Package the HBV Vector
In Example 6, the production and packaging of recombinant replication defective HBV vectors capable of being packaged into infectious particles was described. An alternative approach to using the HBV genome as a vector for gene therapy (i.e., the transfer of genes), is the use of non-infectious HBV vectors which may be either replication competent or replication defective; preferably these vectors are replication competent (i.e., capable of synthesizing additional copies of the viral genome to allow persistent cccDNA in the transduced cell). These vectors cannot be packaged into viral particles because the size of the recombinant viral genome exceeds the packaging limit.
In this approach, the recombinant HBV vector contains at least the HBV pol, core and surface antigen genes (and therefore DR1 and DR2) as well as the gene of interest (the core and pol genes are required to establish persistent ccc viral DNA formation in the transduced cell). The gene of interest is inserted into the tether region of the pol gene as described for the production of HBVtat in Example 1 (i.e., the insertion of the tat gene sequences into the tether region). Sequences encoding the gene of interest will contain the ATG or start codon for the gene of interest but will lack the stop codon located at the 3' end of the gene of interest. Because the resulting recombinant HBV genome is not intended to be packaged into viral particles, there is no limit to size of the foreign gene sequences which can be inserted. The recombinant HBV vector containing the gene of interest is contained within a plasmid and super-coiled plasmid DNA is injected (as naked DNA) into the liver of the recipient. Given the lifecycle of HBV (i.e., the presence of the viral DNA as ccc DNA in the nucleus, the presence of viral RNA in the cytoplasm and the transport of reverse transcribed viral DNA back into the nucleus for the production of additional ccc viral DNA), the recombinant HBV genome would persist in the transduced liver cells (which are essentially non-dividing cells) allowing long term expression of the gene of interest.
As discussed in Example 6, the expression of the HBV X gene is associated with the development of hepatocellular carcinoma therefore the HBV backbone employed is preferentially incapable of expressing the X gene product. The X - form of HBV in plasmid pTHBVX - is used as the source of an HBV genome lacking a functional X gene (construction described in Example 6; this genome contains a mutated X gene and lacks the tat insert present in pTHBVTX - ). The desired genome of interest maybe inserted into the BstEII site of pTHBVX - . The gene of interest is inserted in such a manner as to maintain the reading frame of the pol gene using techniques known to the art (i.e., the start codon of the gene of interest is in frame with the pol gene and the gene of interest lacks a stop codon). A plasmid containing a dimeric form of pTHBVX - containing the gene of interest is generated as described in Example 1 (i.e., a head to tail dimer fused at the EcoRI site within the pol gene) to allow expression of the recombinant virus. Because the insertion of a gene of interest into the pol gene may result in the production of a gene product of interest/pol fusion protein or pol/gene product of interest/pol fusion protein (as described above for expression of Tat within the HBVtat virus), the resulting pol fusion protein may have diminished pol activity as compared to wild-type pol. In this case, sequences encoding the wild-type pol gene under the transcriptional control of an enhancer/promoter capable of high level expression in mammalian (preferably human) liver cells are inserted into the plasmid containing dimer of the recombinant X - HBV genome; the wild-type pol gene cassette is inserted 3' or downstream of the recombinant HBV sequences and in the same transcriptional orientation as the recombinant HBV sequences. Suitable enhancer/promoters for driving the expression of the wild-type pol gene in liver cells include, but are not limited to, the CMV-IE enhancer/promoter, the human elongation factor 1α gene enhancer/promoter (SEQ ID NO:15), the SV40 enhancer/promoter, the RSV LTR, the α-fetoprotein gene enhancer/promoter and a recombinant MuLV LTR containing CMV-IE/HIV-1 TAR sequences (SEQ ID NO:16) (Robinson et al. (1995), supra]. The insertion of the wild-type pol gene cassette permits trans-complementation of the recombinant HBV virus containing the pol/gene of interest fusion.
In order to reduce the likelihood that liver cells transduced with the above recombinant HBV vectors would be subject to attack from the recipient's immune system due to expression of HBV surface antigens, the HBV genome is mutated to abolish expression of the surface antigens while maintaining expression of the pol/gene of interest fusion gene. Site directed mutagenesis is employed to change the start codon (ATG) for the S gene (which encodes the smallest surface antigen) to ACG. The ATG for the S gene is located at nucleotides 157-159 in SEQ ID NO:1; thus, the T at nt 158 is changed to a C. To abolish expression of the preS1 gene, the ATG of the preS1 gene located at nucleotides 2856-2858 in SEQ ID NO:1 is changed to ACG (i.e., the T at nt 3857 is changed to a C). To abolish expression of the preS2 gene, the ATG of the preS2 gene located at nucleotides 3213-3215 in SEQ ID NO:1 is changed to ACG (i.e., the T at nt 3214 is changed to a C).
The reading frames for all three of the surface antigen genes and the pol gene overlap in such a manner that changing the ATG codons of the S, preS1 and preS2 genes results in silent substitutions in the pol gene (in each case a CAT codon in the pol gene is changed to a CAC codon; both codons encode histidine). Because the ACG codon can be used as a start codon (albeit with a lower efficiency than an ATG codon), a stop codon is inserted into the surface antigen genes in such a manner that a silent substitution in the pol gene is generated. The C residue at nucleotide number 173 in SEQ ID NO:1 is changed to an A residue to create a stop codon within the surface antigen genes while maintaining the amino acid sequence encoded by the pol gene (an ATC in the pol gene is changed to a ATA; both codons encode isoleucine).
To introduce the above non-infectious, X - recombinant HBV genomes (with wild-type or mutated S genes and with or without the wild-type pol gene cassette) into the liver of recipient, plasmids containing a dimeric form of the HBV genome are grown in suitable host cells and supercoiled plasmid is prepared using standard techniques. The supercoiled plasmid containing the recombinant HBV genome is then suspended in sterile normal saline (or any other pharmacologically acceptable liquid lacking nucleases) and the suspension is injected directly into the liver of the recipient (e.g., by trans-abdominal injection). Approximately 50 μg of plasmid DNA is injected per injection site and 4 to 5 injection sites are used per liver. Expression of the gene of interest and presence of viral DNA and/or RNA is examined by removal of a small piece of liver tissue following injection (1 to 2 weeks post-injection), preparation of DNA and/or RNA followed by PCR analysis, Southern blot analysis, Northern blot analysis, detection of the product of the gene of interest using a suitable assay. In addition, expression of the gene of interest may be demonstrated by an improvement in clinical parameters in cases where the gene of interest provides a protein lacking in the recipient.
All publications and patents mentioned in the above specification are herein incorporated by reference. Various modifications and variations of the described method and system of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in molecular biology or related fields are intended to be within the scope of the following claims.
__________________________________________________________________________# SEQUENCE LISTING - - - - (1) GENERAL INFORMATION: - - (iii) NUMBER OF SEQUENCES: 16 - - - - (2) INFORMATION FOR SEQ ID NO:1: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 3221 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1: - - AATTCCACTG CCTTCCACCA AACTCTGCAG GATCCCAGAG TCAGGGGTCT GT -#ATCTTCCT 60 - - GCTGGTGGCT CCAGTTCAGG AACAGTAAAC CCTGCTCCGA ATATTGCCTC TC -#ACATCTCG 120 - - TCAATCTCCG CGAGGACTGG GGACCCTGTG ACGAACATGG AGAACATCAC AT -#CAGGATTC 180 - - CTAGGACCCC TGCTCGTGTT ACAGGCGGGG TTTTTCTTGT TGACAAGAAT CC -#TCACAATA 240 - - CCGCAGAGTC TAGACTCGTG GTGGACTTCT CTCAATTTTC TAGGGGGATC TC -#CCGTGTGT 300 - - CTTGGCCAAA ATTCGCAGTC CCCAACCTCC AATCACTCAC CAACCTCCTG TC -#CTCCAATT 360 - - TGTCCTGGTT ATCGCTGGAT GTGTCTGCGG CGTTTTATCA TATTCCTCTT CA -#TCCTGCTG 420 - - CTATGCCTCA TCTTCTTATT GGTTCTTCTG GATTATCAAG GTATGTTGCC CG -#TTTGTCCT 480 - - CTAATTCCAG GATCAACAAC AACCAGTACG GGACCATGCA AAACCTGCAC GA -#CTCCTGCT 540 - - CAAGGCAACT CTATGTTTCC CTCATGTTGC TGTACAAAAC CTACGGATGG AA -#ATTGCACC 600 - - TGTATTCCCA TCCCATCGTC CTGGGCTTTC GCAAAATACC TATGGGAGTG GG -#CCTCAGTC 660 - - CGTTTCTCTT GGCTCAGTTT ACTAGTGCCA TTTGTTCAGT GGTTCGTAGG GC -#TTTCCCCC 720 - - ACTGTTTGGC TTTCAGCTAT ATGGATGATG TGGTATTGGG GGCCAAGTCT GT -#ACAGCATC 780 - - GTGAGTCCCT TTATACCGCT GTTACCAATT TTCTTTTGTC TCTGGGTATA CA -#TTTAAACC 840 - - CTAACAAAAC AAAAAGATGG GGTTATTCCC TAAACTTCAT GGGCTACATA AT -#TGGAAGTT 900 - - GGGGAACTTT GCCACAGGAT CATATTGTAC AAAAGATCAA ACACTGTTTT AG -#AAAACTTC 960 - - CTGTTAACAG GCCTATTGAT TGGAAAGTAT GTCAAAGAAT TGTGGGTCTT TT -#GGGCTTTG 1020 - - CTGCTCCATT TACACAATGT GGATATCCTG CCTTAATGCC TTTGTATGCA TG -#TATACAAG 1080 - - CTAAACAGGC TTTCACTTTC TCGCCAACTT ACAAGGCCTT TCTAAGTAAA CA -#GTACATGA 1140 - - ACCTTTACCC CGTTGCTCGG CAACGGCCTG GTCTGTGCCA AGTGTTTGCT GA -#CGCAACCC 1200 - - CCACTGGCTG GGGCTTGGCC ATAGGCCATC AGCGCATGCG TGGAACCTTT GT -#GGCTCCTC 1260 - - TGCCGATCCA TACTGCGGAA CTCCTAGCCG CTTGTTTTGC TCGCAGCCGG TC -#TGGAGCAA 1320 - - AGCTCATCGG AACTGACAAT TCTGTCGTCC TCTCGCGGAA ATATACATCG TT -#TCCATGGC 1380 - - TGCTAGGCTG TACTGCCAAC TGGATCCTTC GCGGGACGTC CTTTGTTTAC GT -#CCCGTCGG 1440 - - CGCTGAATCC CGCGGACGAC CCCTCTCGGG GCCGCTTGGG ACTCTCTCGT CC -#CCTTCTCC 1500 - - GTCTGCCGTT CCAGCCGACC ACGGGGCGCA CCTCTCTTTA CGCGGTCTCC CC -#GTCTGTGC 1560 - - CTTCTCATCT GCCGGTCCGT GTGCACTTCG CTTCACCTCT GCACGTTGCA TG -#GAGACCAC 1620 - - CGTGAACGCC CATCAGATCC TGCCCAAGGT CTTACATAAG AGGACTCTTG GA -#CTCCCAGC 1680 - - AATGTCAACG ACCGACCTTG AGGCCTACTT CAAAGACTGT GTGTTTAAGG AC -#TGGGAGGA 1740 - - GCTGGGGGAG GAGATTAGGT TAAAGGTCTT TGTATTAGGA GGCTGTAGGC AC -#AAATTGGT 1800 - - CTGCGCACCA GCACCATGCA ACTTTTTCAC CTCTGCCTAA TCATCTCTTG TA -#CATGTCCC 1860 - - ACTGTTCAAG CCTCCAAGCT GTGCCTTGGG TGGCTTTGGG GCATGGACAT TG -#ACCCTTAT 1920 - - AAAGAATTTG GAGCTACTGT GGAGTTACTC TCGTTTTTGC CTTCTGACTT CT -#TTCCTTCC 1980 - - GTCAGAGATC TCCTAGACAC CGCCTCAGCT CTGTATCGAG AAGCCTTAGA GT -#CTCCTGAG 2040 - - CATTCCTCAC CTCACCATAC TGCACTCAGG CAAGCCATTC TCTGCTGGGG GG -#AATTGATG 2100 - - ACTCTAGCTA CCTGGGTGGG TAATAATTTG GAAGATCCAG CATCTAGGGA TC -#TTGTAGTA 2160 - - AATTATGTTA ATACTAACGT GGGTTTAAAG ATCAGGCAAC TATTGTGGTT TC -#ATATATCT 2220 - - TGCCTTACTT TTGGAAGAGA GACTGTACTT GAATATTTGG TCTCTTTCGG AG -#TGTGGATT 2280 - - CGCACTCCTC CAGCCTATAG ACCACCAAAT GCCCCTATCT TATCAACACT TC -#CGGAAACT 2340 - - ACTGTTGTTA GACGACGGGA CCGAGGCAGG TCCCCTAGAA GAAGAACTCC CT -#CGCCTCGC 2400 - - AGACGCAGAT CTCCATCGCC GCGTCGCAGA AGATCTCAAT CTCGGGAATC TC -#AATGTTAG 2460 - - TATTCCTTGG ACTCATAAGG TGGGAAACTT TACGGGGCTT TATTCCTCTA CA -#GTACCTAT 2520 - - CTTTAATCCT GAATGGCAAA CTCCTTCCTT TCCTAAGATT CATTTACAAG AG -#GACATTAT 2580 - - TAATAGGTGT CAACAATTTG TGGGCCCTCT CACTGTAAAT GAAAAGAGAA GA -#TTGAAATT 2640 - - AATTATGCCT GCTAGATTCT ATCCTACCCA CACTAAATAT TTGCCCTTAG AC -#AAAGGAAT 2700 - - TAAACCTTAT TATCCAGATC AGGTAGTTAA TCATTACTTC CAAACCAGAC AT -#TATTTACA 2760 - - TACTCTTTGG AAGGCTGGTA TTCTATATAA GCGGGAAACC ACACGTAGCG CA -#TCATTTTG 2820 - - CGGGTCACCA TATTCTTGGG AACAAGAGCT ACAGCATGGG AGGTTGGTCA TC -#AAAACCTC 2880 - - GCAAAGGCAT GGGGACGAAT CTTTCTGTTC CCAATCCTCT GGGATTCTTT CC -#CGATCATC 2940 - - AGTTGGACCC TGCATTCGGA GCCAACTCAA ACAATCCAGA TTGGGACTTC AA -#CCCCGTCA 3000 - - AGGACGACTG GCCAGCAGCC AACCAAGTAG GAGTGGGAGC ATTCGGGCCA AG -#GCTCACCC 3060 - - CTCCACACGG CGGTATTTTG GGGTGGAGCC CTCAGGCTCA GGGCATATTG AC -#CACAGTGT 3120 - - CAACAATTCC TCCTCCTGCC TCCACCAATC GGCAGTCAGG AAGGCAGCCT AC -#TCCCATCT 3180 - - CTCCACCTCT AAGAGACAGT CATCCTCAGG CCATGCAGTG G - # - # 3221 - - - - (2) INFORMATION FOR SEQ ID NO:2: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 9325 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: circular - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: - - CCCATTCGCC ATTCAGGCTG CGCAACTGTT GGGAAGGGCG ATCGGTGCGG GC -#CTCTTCGC 60 - - TATTACGCCA GCTGGCGAAA GGGGGATGTG CTGCAAGGCG ATTAAGTTGG GT -#AACGCCAG 120 - - GGTTTTCCCA GTCACGACGT TGTAAAACGA CGGCCAGTGC CAAGCTATAT AA -#ATTAACCC 180 - - TCACTAAAGG GAATAAGCTT GCATGCCTGC AGGTCGACTC TAGAGGATCC CC -#GGGTACCG 240 - - AGCTCGAATT CCACTGCCTT CCACCAAACT CTGCAGGATC CCAGAGTCAG GG -#GTCTGTAT 300 - - CTTCCTGCTG GTGGCTCCAG TTCAGGAACA GTAAACCCTG CTCCGAATAT TG -#CCTCTCAC 360 - - ATCTCGTCAA TCTCCGCGAG GACTGGGGAC CCTGTGACGA ACATGGAGAA CA -#TCACATCA 420 - - GGATTCCTAG GACCCCTGCT CGTGTTACAG GCGGGGTTTT TCTTGTTGAC AA -#GAATCCTC 480 - - ACAATACCGC AGAGTCTAGA CTCGTGGTGG ACTTCTCTCA ATTTTCTAGG GG -#GATCTCCC 540 - - GTGTGTCTTG GCCAAAATTC GCAGTCCCCA ACCTCCAATC ACTCACCAAC CT -#CCTGTCCT 600 - - CCAATTTGTC CTGGTTATCG CTGGATGTGT CTGCGGCGTT TTATCATATT CC -#TCTTCATC 660 - - CTGCTGCTAT GCCTCATCTT CTTATTGGTT CTTCTGGATT ATCAAGGTAT GT -#TGCCCGTT 720 - - TGTCCTCTAA TTCCAGGATC AACAACAACC AGTACGGGAC CATGCAAAAC CT -#GCACGACT 780 - - CCTGCTCAAG GCAACTCTAT GTTTCCCTCA TGTTGCTGTA CAAAACCTAC GG -#ATGGAAAT 840 - - TGCACCTGTA TTCCCATCCC ATCGTCCTGG GCTTTCGCAA AATACCTATG GG -#AGTGGGCC 900 - - TCAGTCCGTT TCTCTTGGCT CAGTTTACTA GTGCCATTTG TTCAGTGGTT CG -#TAGGGCTT 960 - - TCCCCCACTG TTTGGCTTTC AGCTATATGG ATGATGTGGT ATTGGGGGCC AA -#GTCTGTAC 1020 - - AGCATCGTGA GTCCCTTTAT ACCGCTGTTA CCAATTTTCT TTTGTCTCTG GG -#TATACATT 1080 - - TAAACCCTAA CAAAACAAAA AGATGGGGTT ATTCCCTAAA CTTCATGGGC TA -#CATAATTG 1140 - - GAAGTTGGGG AACTTTGCCA CAGGATCATA TTGTACAAAA GATCAAACAC TG -#TTTTAGAA 1200 - - AACTTCCTGT TAACAGGCCT ATTGATTGGA AAGTATGTCA AAGAATTGTG GG -#TCTTTTGG 1260 - - GCTTTGCTGC TCCATTTACA CAATGTGGAT ATCCTGCCTT AATGCCTTTG TA -#TGCATGTA 1320 - - TACAAGCTAA ACAGGCTTTC ACTTTCTCGC CAACTTACAA GGCCTTTCTA AG -#TAAACAGT 1380 - - ACATGAACCT TTACCCCGTT GCTCGGCAAC GGCCTGGTCT GTGCCAAGTG TT -#TGCTGACG 1440 - - CAACCCCCAC TGGCTGGGGC TTGGCCATAG GCCATCAGCG CATGCGTGGA AC -#CTTTGTGG 1500 - - CTCCTCTGCC GATCCATACT GCGGAACTCC TAGCCGCTTG TTTTGCTCGC AG -#CCGGTCTG 1560 - - GAGCAAAGCT CATCGGAACT GACAATTCTG TCGTCCTCTC GCGGAAATAT AC -#ATCGTTTC 1620 - - CATGGCTGCT AGGCTGTACT GCCAACTGGA TCCTTCGCGG GACGTCCTTT GT -#TTACGTCC 1680 - - CGTCGGCGCT GAATCCCGCG GACGACCCCT CTCGGGGCCG CTTGGGACTC TC -#TCGTCCCC 1740 - - TTCTCCGTCT GCCGTTCCAG CCGACCACGG GGCGCACCTC TCTTTACGCG GT -#CTCCCCGT 1800 - - CTGTGCCTTC TCATCTGCCG GTCCGTGTGC ACTTCGCTTC ACCTCTGCAC GT -#TGCATGGA 1860 - - GACCACCGTG AACGCCCATC AGATCCTGCC CAAGGTCTTA CATAAGAGGA CT -#CTTGGACT 1920 - - CCCAGCAATG TCAACGACCG ACCTTGAGGC CTACTTCAAA GACTGTGTGT TT -#AAGGACTG 1980 - - GGAGGAGCTG GGGGAGGAGA TTAGGTTAAA GGTCTTTGTA TTAGGAGGCT GT -#AGGCACAA 2040 - - ATTGGTCTGC GCACCAGCAC CATGCAACTT TTTCACCTCT GCCTAATCAT CT -#CTTGTACA 2100 - - TGTCCCACTG TTCAAGCCTC CAAGCTGTGC CTTGGGTGGC TTTGGGGCAT GG -#ACATTGAC 2160 - - CCTTATAAAG AATTTGGAGC TACTGTGGAG TTACTCTCGT TTTTGCCTTC TG -#ACTTCTTT 2220 - - CCTTCCGTCA GAGATCTCCT AGACACCGCC TCAGCTCTGT ATCGAGAAGC CT -#TAGAGTCT 2280 - - CCTGAGCATT CCTCACCTCA CCATACTGCA CTCAGGCAAG CCATTCTCTG CT -#GGGGGGAA 2340 - - TTGATGACTC TAGCTACCTG GGTGGGTAAT AATTTGGAAG ATCCAGCATC TA -#GGGATCTT 2400 - - GTAGTAAATT ATGTTAATAC TAACGTGGGT TTAAAGATCA GGCAACTATT GT -#GGTTTCAT 2460 - - ATATCTTGCC TTACTTTTGG AAGAGAGACT GTACTTGAAT ATTTGGTCTC TT -#TCGGAGTG 2520 - - TGGATTCGCA CTCCTCCAGC CTATAGACCA CCAAATGCCC CTATCTTATC AA -#CACTTCCG 2580 - - GAAACTACTG TTGTTAGACG ACGGGACCGA GGCAGGTCCC CTAGAAGAAG AA -#CTCCCTCG 2640 - - CCTCGCAGAC GCAGATCTCC ATCGCCGCGT CGCAGAAGAT CTCAATCTCG GG -#AATCTCAA 2700 - - TGTTAGTATT CCTTGGACTC ATAAGGTGGG AAACTTTACG GGGCTTTATT CC -#TCTACAGT 2760 - - ACCTATCTTT AATCCTGAAT GGCAAACTCC TTCCTTTCCT AAGATTCATT TA -#CAAGAGGA 2820 - - CATTATTAAT AGGTGTCAAC AATTTGTGGG CCCTCTCACT GTAAATGAAA AG -#AGAAGATT 2880 - - GAAATTAATT ATGCCTGCTA GATTCTATCC TACCCACACT AAATATTTGC CC -#TTAGACAA 2940 - - AGGAATTAAA CCTTATTATC CAGATCAGGT AGTTAATCAT TACTTCCAAA CC -#AGACATTA 3000 - - TTTACATACT CTTTGGAAGG CTGGTATTCT ATATAAGCGG GAAACCACAC GT -#AGCGCATC 3060 - - ATTTTGCGGG TCACCATATT CTTGGGAACA AGAGCTACAG CATGGGAGGT TG -#GTCATCAA 3120 - - AACCTCGCAA AGGCATGGGG ACGAATCTTT CTGTTCCCAA TCCTCTGGGA TT -#CTTTCCCG 3180 - - ATCATCAGTT GGACCCTGCA TTCGGAGCCA ACTCAAACAA TCCAGATTGG GA -#CTTCAACC 3240 - - CCGTCAAGGA CGACTGGCCA GCAGCCAACC AAGTAGGAGT GGGAGCATTC GG -#GCCAAGGC 3300 - - TCACCCCTCC ACACGGCGGT ATTTTGGGGT GGAGCCCTCA GGCTCAGGGC AT -#ATTGACCA 3360 - - CAGTGTCAAC AATTCCTCCT CCTGCCTCCA CCAATCGGCA GTCAGGAAGG CA -#GCCTACTC 3420 - - CCATCTCTCC ACCTCTAAGA GACAGTCATC CTCAGGCCAT GCAGTGGAAT TC -#CACTGCCT 3480 - - TCCACCAAAC TCTGCAGGAT CCCAGAGTCA GGGGTCTGTA TCTTCCTGCT GG -#TGGCTCCA 3540 - - GTTCAGGAAC AGTAAACCCT GCTCCGAATA TTGCCTCTCA CATCTCGTCA AT -#CTCCGCGA 3600 - - GGACTGGGGA CCCTGTGACG AACATGGAGA ACATCACATC AGGATTCCTA GG -#ACCCCTGC 3660 - - TCGTGTTACA GGCGGGGTTT TTCTTGTTGA CAAGAATCCT CACAATACCG CA -#GAGTCTAG 3720 - - ACTCGTGGTG GACTTCTCTC AATTTTCTAG GGGGATCTCC CGTGTGTCTT GG -#CCAAAATT 3780 - - CGCAGTCCCC AACCTCCAAT CACTCACCAA CCTCCTGTCC TCCAATTTGT CC -#TGGTTATC 3840 - - GCTGGATGTG TCTGCGGCGT TTTATCATAT TCCTCTTCAT CCTGCTGCTA TG -#CCTCATCT 3900 - - TCTTATTGGT TCTTCTGGAT TATCAAGGTA TGTTGCCCGT TTGTCCTCTA AT -#TCCAGGAT 3960 - - CAACAACAAC CAGTACGGGA CCATGCAAAA CCTGCACGAC TCCTGCTCAA GG -#CAACTCTA 4020 - - TGTTTCCCTC ATGTTGCTGT ACAAAACCTA CGGATGGAAA TTGCACCTGT AT -#TCCCATCC 4080 - - CATCGTCCTG GGCTTTCGCA AAATACCTAT GGGAGTGGGC CTCAGTCCGT TT -#CTCTTGGC 4140 - - TCAGTTTACT AGTGCCATTT GTTCAGTGGT TCGTAGGGCT TTCCCCCACT GT -#TTGGCTTT 4200 - - CAGCTATATG GATGATGTGG TATTGGGGGC CAAGTCTGTA CAGCATCGTG AG -#TCCCTTTA 4260 - - TACCGCTGTT ACCAATTTTC TTTTGTCTCT GGGTATACAT TTAAACCCTA AC -#AAAACAAA 4320 - - AAGATGGGGT TATTCCCTAA ACTTCATGGG CTACATAATT GGAAGTTGGG GA -#ACTTTGCC 4380 - - ACAGGATCAT ATTGTACAAA AGATCAAACA CTGTTTTAGA AAACTTCCTG TT -#AACAGGCC 4440 - - TATTGATTGG AAAGTATGTC AAAGAATTGT GGGTCTTTTG GGCTTTGCTG CT -#CCATTTAC 4500 - - ACAATGTGGA TATCCTGCCT TAATGCCTTT GTATGCATGT ATACAAGCTA AA -#CAGGCTTT 4560 - - CACTTTCTCG CCAACTTACA AGGCCTTTCT AAGTAAACAG TACATGAACC TT -#TACCCCGT 4620 - - TGCTCGGCAA CGGCCTGGTC TGTGCCAAGT GTTTGCTGAC GCAACCCCCA CT -#GGCTGGGG 4680 - - CTTGGCCATA GGCCATCAGC GCATGCGTGG AACCTTTGTG GCTCCTCTGC CG -#ATCCATAC 4740 - - TGCGGAACTC CTAGCCGCTT GTTTTGCTCG CAGCCGGTCT GGAGCAAAGC TC -#ATCGGAAC 4800 - - TGACAATTCT GTCGTCCTCT CGCGGAAATA TACATCGTTT CCATGGCTGC TA -#GGCTGTAC 4860 - - TGCCAACTGG ATCCTTCGCG GGACGTCCTT TGTTTACGTC CCGTCGGCGC TG -#AATCCCGC 4920 - - GGACGACCCC TCTCGGGGCC GCTTGGGACT CTCTCGTCCC CTTCTCCGTC TG -#CCGTTCCA 4980 - - GCCGACCACG GGGCGCACCT CTCTTTACGC GGTCTCCCCG TCTGTGCCTT CT -#CATCTGCC 5040 - - GGTCCGTGTG CACTTCGCTT CACCTCTGCA CGTTGCATGG AGACCACCGT GA -#ACGCCCAT 5100 - - CAGATCCTGC CCAAGGTCTT ACATAAGAGG ACTCTTGGAC TCCCAGCAAT GT -#CAACGACC 5160 - - GACCTTGAGG CCTACTTCAA AGACTGTGTG TTTAAGGACT GGGAGGAGCT GG -#GGGAGGAG 5220 - - ATTAGGTTAA AGGTCTTTGT ATTAGGAGGC TGTAGGCACA AATTGGTCTG CG -#CACCAGCA 5280 - - CCATGCAACT TTTTCACCTC TGCCTAATCA TCTCTTGTAC ATGTCCCACT GT -#TCAAGCCT 5340 - - CCAAGCTGTG CCTTGGGTGG CTTTGGGGCA TGGACATTGA CCCTTATAAA GA -#ATTTGGAG 5400 - - CTACTGTGGA GTTACTCTCG TTTTTGCCTT CTGACTTCTT TCCTTCCGTC AG -#AGATCTCC 5460 - - TAGACACCGC CTCAGCTCTG TATCGAGAAG CCTTAGAGTC TCCTGAGCAT TC -#CTCACCTC 5520 - - ACCATACTGC ACTCAGGCAA GCCATTCTCT GCTGGGGGGA ATTGATGACT CT -#AGCTACCT 5580 - - GGGTGGGTAA TAATTTGGAA GATCCAGCAT CTAGGGATCT TGTAGTAAAT TA -#TGTTAATA 5640 - - CTAACGTGGG TTTAAAGATC AGGCAACTAT TGTGGTTTCA TATATCTTGC CT -#TACTTTTG 5700 - - GAAGAGAGAC TGTACTTGAA TATTTGGTCT CTTTCGGAGT GTGGATTCGC AC -#TCCTCCAG 5760 - - CCTATAGACC ACCAAATGCC CCTATCTTAT CAACACTTCC GGAAACTACT GT -#TGTTAGAC 5820 - - GACGGGACCG AGGCAGGTCC CCTAGAAGAA GAACTCCCTC GCCTCGCAGA CG -#CAGATCTC 5880 - - CATCGCCGCG TCGCAGAAGA TCTCAATCTC GGGAATCTCA ATGTTAGTAT TC -#CTTGGACT 5940 - - CATAAGGTGG GAAACTTTAC GGGGCTTTAT TCCTCTACAG TACCTATCTT TA -#ATCCTGAA 6000 - - TGGCAAACTC CTTCCTTTCC TAAGATTCAT TTACAAGAGG ACATTATTAA TA -#GGTGTCAA 6060 - - CAATTTGTGG GCCCTCTCAC TGTAAATGAA AAGAGAAGAT TGAAATTAAT TA -#TGCCTGCT 6120 - - AGATTCTATC CTACCCACAC TAAATATTTG CCCTTAGACA AAGGAATTAA AC -#CTTATTAT 6180 - - CCAGATCAGG TAGTTAATCA TTACTTCCAA ACCAGACATT ATTTACATAC TC -#TTTGGAAG 6240 - - GCTGGTATTC TATATAAGCG GGAAACCACA CGTAGCGCAT CATTTTGCGG GT -#CACCATAT 6300 - - TCTTGGGAAC AAGAGCTACA GCATGGGAGG TTGGTCATCA AAACCTCGCA AA -#GGCATGGG 6360 - - GACGAATCTT TCTGTTCCCA ATCCTCTGGG ATTCTTTCCC GATCATCAGT TG -#GACCCTGC 6420 - - ATTCGGAGCC AACTCAAACA ATCCAGATTG GGACTTCAAC CCCGTCAAGG AC -#GACTGGCC 6480 - - AGCAGCCAAC CAAGTAGGAG TGGGAGCATT CGGGCCAAGG CTCACCCCTC CA -#CACGGCGG 6540 - - TATTTTGGGG TGGAGCCCTC AGGCTCAGGG CATATTGACC ACAGTGTCAA CA -#ATTCCTCC 6600 - - TCCTGCCTCC ACCAATCGGC AGTCAGGAAG GCAGCCTACT CCCATCTCTC CA -#CCTCTAAG 6660 - - AGACAGTCAT CCTCAGGCCA TGCAGTGGAA TTCCCTATAG TGAGTCGTAT TA -#AATTCGTA 6720 - - ATCATGGTCA TAGCTGTTTC CTGTGTGAAA TTGTTATCCG CTCACAATTC CA -#CACAACAT 6780 - - ACGAGCCGGA AGCATAAAGT GTAAAGCCTG GGGTGCCTAA TGAGTGAGCT AA -#CTCACATT 6840 - - AATTGCGTTG CGCTCACTGC CCGCTTTCCA GTCGGGAAAC CTGTCGTGCC AG -#CTGCATTA 6900 - - ATGAATCGGC CAACGCGCGG GGAGAGGCGG TTTGCGTATT GGGCGCTCTT CC -#GCTTCCTC 6960 - - GCTCACTGAC TCGCTGCGCT CGGTCGTTCG GCTGCGGCGA GCGGTATCAG CT -#CACTCAAA 7020 - - GGCGGTAATA CGGTTATCCA CAGAATCAGG GGATAACGCA GGAAAGAACA TG -#TGAGCAAA 7080 - - AGGCCAGCAA AAGGCCAGGA ACCGTAAAAA GGCCGCGTTG CTGGCGTTTT TC -#CATAGGCT 7140 - - CCGCCCCCCT GACGAGCATC ACAAAAATCG ACGCTCAAGT CAGAGGTGGC GA -#AACCCGAC 7200 - - AGGACTATAA AGATACCAGG CGTTTCCCCC TGGAAGCTCC CTCGTGCGCT CT -#CCTGTTCC 7260 - - GACCCTGCCG CTTACCGGAT ACCTGTCCGC CTTTCTCCCT TCGGGAAGCG TG -#GCGCTTTC 7320 - - TCAATGCTCA CGCTGTAGGT ATCTCAGTTC GGTGTAGGTC GTTCGCTCCA AG -#CTGGGCTG 7380 - - TGTGCACGAA CCCCCCGTTC AGCCCGACCG CTGCGCCTTA TCCGGTAACT AT -#CGTCTTGA 7440 - - GTCCAACCCG GTAAGACACG ACTTATCGCC ACTGGCAGCA GCCACTGGTA AC -#AGGATTAG 7500 - - CAGAGCGAGG TATGTAGGCG GTGCTACAGA GTTCTTGAAG TGGTGGCCTA AC -#TACGGCTA 7560 - - CACTAGAAGA ACAGTATTTG GTATCTGCGC TCTGCTGAAG CCAGTTACCT TC -#GGAAAAAG 7620 - - AGTTGGTAGC TCTTGATCCG GCAAACAAAC CACCGCTGGT AGCGGTGGTT TT -#TTTGTTTG 7680 - - CAAGCAGCAG ATTACGCGCA GAAAAAAAGG ATCTCAAGAA GATCCTTTGA TC -#TTTTCTAC 7740 - - GGGGTCTGAC GCTCAGTGGA ACGAAAACTC ACGTTAAGGG ATTTTGGTCA TG -#AGATTATC 7800 - - AAAAAGGATC TTCACCTAGA TCCTTTTAAA TTAAAAATGA AGTTTTAAAT CA -#ATCTAAAG 7860 - - TATATATGAG TAAACTTGGT CTGACAGTTA CCAATGCTTA ATCAGTGAGG CA -#CCTATCTC 7920 - - AGCGATCTGT CTATTTCGTT CATCCATAGT TGCCTGACTC CCCGTCGTGT AG -#ATAACTAC 7980 - - GATACGGGAG GGCTTACCAT CTGGCCCCAG TGCTGCAATG ATACCGCGAG AC -#CCACGCTC 8040 - - ACCGGCTCCA GATTTATCAG CAATAAACCA GCCAGCCGGA AGGGCCGAGC GC -#AGAAGTGG 8100 - - TCCTGCAACT TTATCCGCCT CCATCCAGTC TATTAATTGT TGCCGGGAAG CT -#AGAGTAAG 8160 - - TAGTTCGCCA GTTAATAGTT TGCGCAACGT TGTTGCCATT GCTACAGGCA TC -#GTGGTGTC 8220 - - ACGCTCGTCG TTTGGTATGG CTTCATTCAG CTCCGGTTCC CAACGATCAA GG -#CGAGTTAC 8280 - - ATGATCCCCC ATGTTGTGCA AAAAAGCGGT TAGCTCCTTC GGTCCTCCGA TC -#GTTGTCAG 8340 - - AAGTAAGTTG GCCGCAGTGT TATCACTCAT GGTTATGGCA GCACTGCATA AT -#TCTCTTAC 8400 - - TGTCATGCCA TCCGTAAGAT GCTTTTCTGT GACTGGTGAG TACTCAACCA AG -#TCATTCTG 8460 - - AGAATAGTGT ATGCGGCGAC CGAGTTGCTC TTGCCCGGCG TCAATACGGG AT -#AATACCGC 8520 - - GCCACATAGC AGAACTTTAA AAGTGCTCAT CATTGGAAAA CGTTCTTCGG GG -#CGAAAACT 8580 - - CTCAAGGATC TTACCGCTGT TGAGATCCAG TTCGATGTAA CCCACTCGTG CA -#CCCAACTG 8640 - - ATCTTCAGCA TCTTTTACTT TCACCAGCGT TTCTGGGTGA GCAAAAACAG GA -#AGGCAAAA 8700 - - TGCCGCAAAA AAGGGAATAA GGGCGACACG GAAATGTTGA ATACTCATAC TC -#TTCCTTTT 8760 - - TCAATATTAT TGAAGCATTT ATCAGGGTTA TTGTCTCATG AGCGGATACA TA -#TTTGAATG 8820 - - TATTTAGAAA AATAAACAAA TAGGGGTTCC GCGCACATTT CCCCGAAAAG TG -#CCACCTGA 8880 - - AATTGTAAAC GTTAATGTTT TGTTAAATTT CGCGTTAAAT ATTTGTTAAA TC -#AGCTTATT 8940 - - TTTTAACCAG TAAGCAGAAA ATGACAAAAA TCCTTATAAA TCAAAAGAAT AG -#ACCGAGTT 9000 - - AGTTGTGAGT GTTGTTCCAG TTTGGAACAA GAGTCCACTA TTAAAGAACG TG -#GACTCCAA 9060 - - CGTAAAACCG TCTATCAGGG CGATGGCCCA CTACGTGAAC CATCACCCAA AT -#CAAGTTTT 9120 - - TGGAGGTCGA GGTGCCGTAA AGCACTAAAT CGGAACCCTA AAGGGAGCCC CC -#GATTTAGA 9180 - - GCTTGACGGG GAAAGCCGGC GAACGTGGCG AGAAAGGAAG GGAAGAAAGC GA -#AAGGAGCG 9240 - - GGCGCTAGGG CGCTGGCAAG TGTAGCGGTC ACGCTGCGCG TAACCACCAC AC -#CCGCCGCG 9300 - - CTTAATGCGC CGCTACTGGG CGCGT - # - # 9325 - - - - (2) INFORMATION FOR SEQ ID NO:3: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 33 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: - - TGCGGGTCAC CAATGGAGCC AGTAGATCCT AAT - # - # 33 - - - - (2) INFORMATION FOR SEQ ID NO:4: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 33 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: - - ATATGGTGAC CCTTCCGTGG GCCCTGTCGG GTC - # - # 33 - - - - (2) INFORMATION FOR SEQ ID NO:5: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 6371 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: circular - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5: - - CCCATTCGCC ATTCAGGCTG CGCAACTGTT GGGAAGGGCG ATCGGTGCGG GC -#CTCTTCGC 60 - - TATTACGCCA GCTGGCGAAA GGGGGATGTG CTGCAAGGCG ATTAAGTTGG GT -#AACGCCAG 120 - - GGTTTTCCCA GTCACGACGT TGTAAAACGA CGGCCAGTGC CAAGCTATAT AA -#ATTAACCC 180 - - TCACTAAAGG GAATAAGCTT GCATGCCTGC AGGTCGACTC TAGAGGATCC CC -#GGGTACCG 240 - - AGCTCGAATT CCACTGCCTT CCACCAAACT CTGCAGGATC CCAGAGTCAG GG -#GTCTGTAT 300 - - CTTCCTGCTG GTGGCTCCAG TTCAGGAACA GTAAACCCTG CTCCGAATAT TG -#CCTCTCAC 360 - - ATCTCGTCAA TCTCCGCGAG GACTGGGGAC CCTGTGACGA ACATGGAGAA CA -#TCACATCA 420 - - GGATTCCTAG GACCCCTGCT CGTGTTACAG GCGGGGTTTT TCTTGTTGAC AA -#GAATCCTC 480 - - ACAATACCGC AGAGTCTAGA CTCGTGGTGG ACTTCTCTCA ATTTTCTAGG GG -#GATCTCCC 540 - - GTGTGTCTTG GCCAAAATTC GCAGTCCCCA ACCTCCAATC ACTCACCAAC CT -#CCTGTCCT 600 - - CCAATTTGTC CTGGTTATCG CTGGATGTGT CTGCGGCGTT TTATCATATT CC -#TCTTCATC 660 - - CTGCTGCTAT GCCTCATCTT CTTATTGGTT CTTCTGGATT ATCAAGGTAT GT -#TGCCCGTT 720 - - TGTCCTCTAA TTCCAGGATC AACAACAACC AGTACGGGAC CATGCAAAAC CT -#GCACGACT 780 - - CCTGCTCAAG GCAACTCTAT GTTTCCCTCA TGTTGCTGTA CAAAACCTAC GG -#ATGGAAAT 840 - - TGCACCTGTA TTCCCATCCC ATCGTCCTGG GCTTTCGCAA AATACCTATG GG -#AGTGGGCC 900 - - TCAGTCCGTT TCTCTTGGCT CAGTTTACTA GTGCCATTTG TTCAGTGGTT CG -#TAGGGCTT 960 - - TCCCCCACTG TTTGGCTTTC AGCTATATGG ATGATGTGGT ATTGGGGGCC AA -#GTCTGTAC 1020 - - AGCATCGTGA GTCCCTTTAT ACCGCTGTTA CCAATTTTCT TTTGTCTCTG GG -#TATACATT 1080 - - TAAACCCTAA CAAAACAAAA AGATGGGGTT ATTCCCTAAA CTTCATGGGC TA -#CATAATTG 1140 - - GAAGTTGGGG AACTTTGCCA CAGGATCATA TTGTACAAAA GATCAAACAC TG -#TTTTAGAA 1200 - - AACTTCCTGT TAACAGGCCT ATTGATTGGA AAGTATGTCA AAGAATTGTG GG -#TCTTTTGG 1260 - - GCTTTGCTGC TCCATTTACA CAATGTGGAT ATCCTGCCTT AATGCCTTTG TA -#TGCATGTA 1320 - - TACAAGCTAA ACAGGCTTTC ACTTTCTCGC CAACTTACAA GGCCTTTCTA AG -#TAAACAGT 1380 - - ACATGAACCT TTACCCCGTT GCTCGGCAAC GGCCTGGTCT GTGCCAAGTG TT -#TGCTGACG 1440 - - CAACCCCCAC TGGCTGGGGC TTGGCCATAG GCCATCAGCG CATGCGTGGA AC -#CTTTGTGG 1500 - - CTCCTCTGCC GATCCATACT GCGGAACTCC TAGCCGCTTG TTTTGCTCGC AG -#CCGGTCTG 1560 - - GAGCAAAGCT CATCGGAACT GACAATTCTG TCGTCCTCTC GCGGAAATAT AC -#ATCGTTTC 1620 - - CATGGCTGCT AGGCTGTACT GCCAACTGGA TCCTTCGCGG GACGTCCTTT GT -#TTACGTCC 1680 - - CGTCGGCGCT GAATCCCGCG GACGACCCCT CTCGGGGCCG CTTGGGACTC TC -#TCGTCCCC 1740 - - TTCTCCGTCT GCCGTTCCAG CCGACCACGG GGCGCACCTC TCTTTACGCG GT -#CTCCCCGT 1800 - - CTGTGCCTTC TCATCTGCCG GTCCGTGTGC ACTTCGCTTC ACCTCTGCAC GT -#TGCATGGA 1860 - - GACCACCGTG AACGCCCATC AGATCCTGCC CAAGGTCTTA CATAAGAGGA CT -#CTTGGACT 1920 - - CCCAGCAATG TCAACGACCG ACCTTGAGGC CTACTTCAAA GACTGTGTGT TT -#AAGGACTG 1980 - - GGAGGAGCTG GGGGAGGAGA TTAGGTTAAA GGTCTTTGTA TTAGGAGGCT GT -#AGGCACAA 2040 - - ATTGGTCTGC GCACCAGCAC CATGCAACTT TTTCACCTCT GCCTAATCAT CT -#CTTGTACA 2100 - - TGTCCCACTG TTCAAGCCTC CAAGCTGTGC CTTGGGTGGC TTTGGGGCAT GG -#ACATTGAC 2160 - - CCTTATAAAG AATTTGGAGC TACTGTGGAG TTACTCTCGT TTTTGCCTTC TG -#ACTTCTTT 2220 - - CCTTCCGTCA GAGATCTCCT AGACACCGCC TCAGCTCTGT ATCGAGAAGC CT -#TAGAGTCT 2280 - - CCTGAGCATT CCTCACCTCA CCATACTGCA CTCAGGCAAG CCATTCTCTG CT -#GGGGGGAA 2340 - - TTGATGACTC TAGCTACCTG GGTGGGTAAT AATTTGGAAG ATCCAGCATC TA -#GGGATCTT 2400 - - GTAGTAAATT ATGTTAATAC TAACGTGGGT TTAAAGATCA GGCAACTATT GT -#GGTTTCAT 2460 - - ATATCTTGCC TTACTTTTGG AAGAGAGACT GTACTTGAAT ATTTGGTCTC TT -#TCGGAGTG 2520 - - TGGATTCGCA CTCCTCCAGC CTATAGACCA CCAAATGCCC CTATCTTATC AA -#CACTTCCG 2580 - - GAAACTACTG TTGTTAGACG ACGGGACCGA GGCAGGTCCC CTAGAAGAAG AA -#CTCCCTCG 2640 - - CCTCGCAGAC GCAGATCTCC ATCGCCGCGT CGCAGAAGAT CTCAATCTCG GG -#AATCTCAA 2700 - - TGTTAGTATT CCTTGGACTC ATAAGGTGGG AAACTTTACG GGGCTTTATT CC -#TCTACAGT 2760 - - ACCTATCTTT AATCCTGAAT GGCAAACTCC TTCCTTTCCT AAGATTCATT TA -#CAAGAGGA 2820 - - CATTATTAAT AGGTGTCAAC AATTTGTGGG CCCTCTCACT GTAAATGAAA AG -#AGAAGATT 2880 - - GAAATTAATT ATGCCTGCTA GATTCTATCC TACCCACACT AAATATTTGC CC -#TTAGACAA 2940 - - AGGAATTAAA CCTTATTATC CAGATCAGGT AGTTAATCAT TACTTCCAAA CC -#AGACATTA 3000 - - TTTACATACT CTTTGGAAGG CTGGTATTCT ATATAAGCGG GAAACCACAC GT -#AGCGCATC 3060 - - ATTTTGCGGG TCACCAATGG AGCCAGTAGA TCCTAATCTA GAGCCCTGGA AG -#CATCCAGG 3120 - - AAGTCAGCCT AAAACTGCTT GTACCAATTG CTATTGTAAA AAGTGTTGCT TT -#CATTGCCA 3180 - - AGTTTGTTTC ATGACAAAAG CCTTAGGCAT CTCCTATGGC AGGAAGAAGC GG -#AGACAGCG 3240 - - ACGAAGAGCT CATCAGAACA GTCAGACTCA TCAAGCTTCT CTATCAAAGC AA -#CCCACCTC 3300 - - CCAATCCCGA GGGGACCCGA CAGGGCCCAC GGAAGGGTCA CCATATTCTT GG -#GAACAAGA 3360 - - GCTACAGCAT GGGAGGTTGG TCATCAAAAC CTCGCAAAGG CATGGGGACG AA -#TCTTTCTG 3420 - - TTCCCAATCC TCTGGGATTC TTTCCCGATC ATCAGTTGGA CCCTGCATTC GG -#AGCCAACT 3480 - - CAAACAATCC AGATTGGGAC TTCAACCCCG TCAAGGACGA CTGGCCAGCA GC -#CAACCAAG 3540 - - TAGGAGTGGG AGCATTCGGG CCAAGGCTCA CCCCTCCACA CGGCGGTATT TT -#GGGGTGGA 3600 - - GCCCTCAGGC TCAGGGCATA TTGACCACAG TGTCAACAAT TCCTCCTCCT GC -#CTCCACCA 3660 - - ATCGGCAGTC AGGAAGGCAG CCTACTCCCA TCTCTCCACC TCTAAGAGAC AG -#TCATCCTC 3720 - - AGGCCATGCA GTGGAATTCC CTATAGTGAG TCGTATTAAA TTCGTAATCA TG -#GTCATAGC 3780 - - TGTTTCCTGT GTGAAATTGT TATCCGCTCA CAATTCCACA CAACATACGA GC -#CGGAAGCA 3840 - - TAAAGTGTAA AGCCTGGGGT GCCTAATGAG TGAGCTAACT CACATTAATT GC -#GTTGCGCT 3900 - - CACTGCCCGC TTTCCAGTCG GGAAACCTGT CGTGCCAGCT GCATTAATGA AT -#CGGCCAAC 3960 - - GCGCGGGGAG AGGCGGTTTG CGTATTGGGC GCTCTTCCGC TTCCTCGCTC AC -#TGACTCGC 4020 - - TGCGCTCGGT CGTTCGGCTG CGGCGAGCGG TATCAGCTCA CTCAAAGGCG GT -#AATACGGT 4080 - - TATCCACAGA ATCAGGGGAT AACGCAGGAA AGAACATGTG AGCAAAAGGC CA -#GCAAAAGG 4140 - - CCAGGAACCG TAAAAAGGCC GCGTTGCTGG CGTTTTTCCA TAGGCTCCGC CC -#CCCTGACG 4200 - - AGCATCACAA AAATCGACGC TCAAGTCAGA GGTGGCGAAA CCCGACAGGA CT -#ATAAAGAT 4260 - - ACCAGGCGTT TCCCCCTGGA AGCTCCCTCG TGCGCTCTCC TGTTCCGACC CT -#GCCGCTTA 4320 - - CCGGATACCT GTCCGCCTTT CTCCCTTCGG GAAGCGTGGC GCTTTCTCAA TG -#CTCACGCT 4380 - - GTAGGTATCT CAGTTCGGTG TAGGTCGTTC GCTCCAAGCT GGGCTGTGTG CA -#CGAACCCC 4440 - - CCGTTCAGCC CGACCGCTGC GCCTTATCCG GTAACTATCG TCTTGAGTCC AA -#CCCGGTAA 4500 - - GACACGACTT ATCGCCACTG GCAGCAGCCA CTGGTAACAG GATTAGCAGA GC -#GAGGTATG 4560 - - TAGGCGGTGC TACAGAGTTC TTGAAGTGGT GGCCTAACTA CGGCTACACT AG -#AAGAACAG 4620 - - TATTTGGTAT CTGCGCTCTG CTGAAGCCAG TTACCTTCGG AAAAAGAGTT GG -#TAGCTCTT 4680 - - GATCCGGCAA ACAAACCACC GCTGGTAGCG GTGGTTTTTT TGTTTGCAAG CA -#GCAGATTA 4740 - - CGCGCAGAAA AAAAGGATCT CAAGAAGATC CTTTGATCTT TTCTACGGGG TC -#TGACGCTC 4800 - - AGTGGAACGA AAACTCACGT TAAGGGATTT TGGTCATGAG ATTATCAAAA AG -#GATCTTCA 4860 - - CCTAGATCCT TTTAAATTAA AAATGAAGTT TTAAATCAAT CTAAAGTATA TA -#TGAGTAAA 4920 - - CTTGGTCTGA CAGTTACCAA TGCTTAATCA GTGAGGCACC TATCTCAGCG AT -#CTGTCTAT 4980 - - TTCGTTCATC CATAGTTGCC TGACTCCCCG TCGTGTAGAT AACTACGATA CG -#GGAGGGCT 5040 - - TACCATCTGG CCCCAGTGCT GCAATGATAC CGCGAGACCC ACGCTCACCG GC -#TCCAGATT 5100 - - TATCAGCAAT AAACCAGCCA GCCGGAAGGG CCGAGCGCAG AAGTGGTCCT GC -#AACTTTAT 5160 - - CCGCCTCCAT CCAGTCTATT AATTGTTGCC GGGAAGCTAG AGTAAGTAGT TC -#GCCAGTTA 5220 - - ATAGTTTGCG CAACGTTGTT GCCATTGCTA CAGGCATCGT GGTGTCACGC TC -#GTCGTTTG 5280 - - GTATGGCTTC ATTCAGCTCC GGTTCCCAAC GATCAAGGCG AGTTACATGA TC -#CCCCATGT 5340 - - TGTGCAAAAA AGCGGTTAGC TCCTTCGGTC CTCCGATCGT TGTCAGAAGT AA -#GTTGGCCG 5400 - - CAGTGTTATC ACTCATGGTT ATGGCAGCAC TGCATAATTC TCTTACTGTC AT -#GCCATCCG 5460 - - TAAGATGCTT TTCTGTGACT GGTGAGTACT CAACCAAGTC ATTCTGAGAA TA -#GTGTATGC 5520 - - GGCGACCGAG TTGCTCTTGC CCGGCGTCAA TACGGGATAA TACCGCGCCA CA -#TAGCAGAA 5580 - - CTTTAAAAGT GCTCATCATT GGAAAACGTT CTTCGGGGCG AAAACTCTCA AG -#GATCTTAC 5640 - - CGCTGTTGAG ATCCAGTTCG ATGTAACCCA CTCGTGCACC CAACTGATCT TC -#AGCATCTT 5700 - - TTACTTTCAC CAGCGTTTCT GGGTGAGCAA AAACAGGAAG GCAAAATGCC GC -#AAAAAAGG 5760 - - GAATAAGGGC GACACGGAAA TGTTGAATAC TCATACTCTT CCTTTTTCAA TA -#TTATTGAA 5820 - - GCATTTATCA GGGTTATTGT CTCATGAGCG GATACATATT TGAATGTATT TA -#GAAAAATA 5880 - - AACAAATAGG GGTTCCGCGC ACATTTCCCC GAAAAGTGCC ACCTGAAATT GT -#AAACGTTA 5940 - - ATGTTTTGTT AAATTTCGCG TTAAATATTT GTTAAATCAG CTTATTTTTT AA -#CCAGTAAG 6000 - - CAGAAAATGA CAAAAATCCT TATAAATCAA AAGAATAGAC CGAGTTAGTT GT -#GAGTGTTG 6060 - - TTCCAGTTTG GAACAAGAGT CCACTATTAA AGAACGTGGA CTCCAACGTA AA -#ACCGTCTA 6120 - - TCAGGGCGAT GGCCCACTAC GTGAACCATC ACCCAAATCA AGTTTTTGGA GG -#TCGAGGTG 6180 - - CCGTAAAGCA CTAAATCGGA ACCCTAAAGG GAGCCCCCGA TTTAGAGCTT GA -#CGGGGAAA 6240 - - GCCGGCGAAC GTGGCGAGAA AGGAAGGGAA GAAAGCGAAA GGAGCGGGCG CT -#AGGGCGCT 6300 - - GGCAAGTGTA GCGGTCACGC TGCGCGTAAC CACCACACCC GCCGCGCTTA AT -#GCGCCGCT 6360 - - ACTGGGCGCG T - # - # - # 6371 - - - - (2) INFORMATION FOR SEQ ID NO:6: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 9859 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: circular - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6: - - CCCATTCGCC ATTCAGGCTG CGCAACTGTT GGGAAGGGCG ATCGGTGCGG GC -#CTCTTCGC 60 - - TATTACGCCA GCTGGCGAAA GGGGGATGTG CTGCAAGGCG ATTAAGTTGG GT -#AACGCCAG 120 - - GGTTTTCCCA GTCACGACGT TGTAAAACGA CGGCCAGTGC CAAGCTATAT AA -#ATTAACCC 180 - - TCACTAAAGG GAATAAGCTT GCATGCCTGC AGGTCGACTC TAGAGGATCC CC -#GGGTACCG 240 - - AGCTCGAATT CCACTGCCTT CCACCAAACT CTGCAGGATC CCAGAGTCAG GG -#GTCTGTAT 300 - - CTTCCTGCTG GTGGCTCCAG TTCAGGAACA GTAAACCCTG CTCCGAATAT TG -#CCTCTCAC 360 - - ATCTCGTCAA TCTCCGCGAG GACTGGGGAC CCTGTGACGA ACATGGAGAA CA -#TCACATCA 420 - - GGATTCCTAG GACCCCTGCT CGTGTTACAG GCGGGGTTTT TCTTGTTGAC AA -#GAATCCTC 480 - - ACAATACCGC AGAGTCTAGA CTCGTGGTGG ACTTCTCTCA ATTTTCTAGG GG -#GATCTCCC 540 - - GTGTGTCTTG GCCAAAATTC GCAGTCCCCA ACCTCCAATC ACTCACCAAC CT -#CCTGTCCT 600 - - CCAATTTGTC CTGGTTATCG CTGGATGTGT CTGCGGCGTT TTATCATATT CC -#TCTTCATC 660 - - CTGCTGCTAT GCCTCATCTT CTTATTGGTT CTTCTGGATT ATCAAGGTAT GT -#TGCCCGTT 720 - - TGTCCTCTAA TTCCAGGATC AACAACAACC AGTACGGGAC CATGCAAAAC CT -#GCACGACT 780 - - CCTGCTCAAG GCAACTCTAT GTTTCCCTCA TGTTGCTGTA CAAAACCTAC GG -#ATGGAAAT 840 - - TGCACCTGTA TTCCCATCCC ATCGTCCTGG GCTTTCGCAA AATACCTATG GG -#AGTGGGCC 900 - - TCAGTCCGTT TCTCTTGGCT CAGTTTACTA GTGCCATTTG TTCAGTGGTT CG -#TAGGGCTT 960 - - TCCCCCACTG TTTGGCTTTC AGCTATATGG ATGATGTGGT ATTGGGGGCC AA -#GTCTGTAC 1020 - - AGCATCGTGA GTCCCTTTAT ACCGCTGTTA CCAATTTTCT TTTGTCTCTG GG -#TATACATT 1080 - - TAAACCCTAA CAAAACAAAA AGATGGGGTT ATTCCCTAAA CTTCATGGGC TA -#CATAATTG 1140 - - GAAGTTGGGG AACTTTGCCA CAGGATCATA TTGTACAAAA GATCAAACAC TG -#TTTTAGAA 1200 - - AACTTCCTGT TAACAGGCCT ATTGATTGGA AAGTATGTCA AAGAATTGTG GG -#TCTTTTGG 1260 - - GCTTTGCTGC TCCATTTACA CAATGTGGAT ATCCTGCCTT AATGCCTTTG TA -#TGCATGTA 1320 - - TACAAGCTAA ACAGGCTTTC ACTTTCTCGC CAACTTACAA GGCCTTTCTA AG -#TAAACAGT 1380 - - ACATGAACCT TTACCCCGTT GCTCGGCAAC GGCCTGGTCT GTGCCAAGTG TT -#TGCTGACG 1440 - - CAACCCCCAC TGGCTGGGGC TTGGCCATAG GCCATCAGCG CATGCGTGGA AC -#CTTTGTGG 1500 - - CTCCTCTGCC GATCCATACT GCGGAACTCC TAGCCGCTTG TTTTGCTCGC AG -#CCGGTCTG 1560 - - GAGCAAAGCT CATCGGAACT GACAATTCTG TCGTCCTCTC GCGGAAATAT AC -#ATCGTTTC 1620 - - CATGGCTGCT AGGCTGTACT GCCAACTGGA TCCTTCGCGG GACGTCCTTT GT -#TTACGTCC 1680 - - CGTCGGCGCT GAATCCCGCG GACGACCCCT CTCGGGGCCG CTTGGGACTC TC -#TCGTCCCC 1740 - - TTCTCCGTCT GCCGTTCCAG CCGACCACGG GGCGCACCTC TCTTTACGCG GT -#CTCCCCGT 1800 - - CTGTGCCTTC TCATCTGCCG GTCCGTGTGC ACTTCGCTTC ACCTCTGCAC GT -#TGCATGGA 1860 - - GACCACCGTG AACGCCCATC AGATCCTGCC CAAGGTCTTA CATAAGAGGA CT -#CTTGGACT 1920 - - CCCAGCAATG TCAACGACCG ACCTTGAGGC CTACTTCAAA GACTGTGTGT TT -#AAGGACTG 1980 - - GGAGGAGCTG GGGGAGGAGA TTAGGTTAAA GGTCTTTGTA TTAGGAGGCT GT -#AGGCACAA 2040 - - ATTGGTCTGC GCACCAGCAC CATGCAACTT TTTCACCTCT GCCTAATCAT CT -#CTTGTACA 2100 - - TGTCCCACTG TTCAAGCCTC CAAGCTGTGC CTTGGGTGGC TTTGGGGCAT GG -#ACATTGAC 2160 - - CCTTATAAAG AATTTGGAGC TACTGTGGAG TTACTCTCGT TTTTGCCTTC TG -#ACTTCTTT 2220 - - CCTTCCGTCA GAGATCTCCT AGACACCGCC TCAGCTCTGT ATCGAGAAGC CT -#TAGAGTCT 2280 - - CCTGAGCATT CCTCACCTCA CCATACTGCA CTCAGGCAAG CCATTCTCTG CT -#GGGGGGAA 2340 - - TTGATGACTC TAGCTACCTG GGTGGGTAAT AATTTGGAAG ATCCAGCATC TA -#GGGATCTT 2400 - - GTAGTAAATT ATGTTAATAC TAACGTGGGT TTAAAGATCA GGCAACTATT GT -#GGTTTCAT 2460 - - ATATCTTGCC TTACTTTTGG AAGAGAGACT GTACTTGAAT ATTTGGTCTC TT -#TCGGAGTG 2520 - - TGGATTCGCA CTCCTCCAGC CTATAGACCA CCAAATGCCC CTATCTTATC AA -#CACTTCCG 2580 - - GAAACTACTG TTGTTAGACG ACGGGACCGA GGCAGGTCCC CTAGAAGAAG AA -#CTCCCTCG 2640 - - CCTCGCAGAC GCAGATCTCC ATCGCCGCGT CGCAGAAGAT CTCAATCTCG GG -#AATCTCAA 2700 - - TGTTAGTATT CCTTGGACTC ATAAGGTGGG AAACTTTACG GGGCTTTATT CC -#TCTACAGT 2760 - - ACCTATCTTT AATCCTGAAT GGCAAACTCC TTCCTTTCCT AAGATTCATT TA -#CAAGAGGA 2820 - - CATTATTAAT AGGTGTCAAC AATTTGTGGG CCCTCTCACT GTAAATGAAA AG -#AGAAGATT 2880 - - GAAATTAATT ATGCCTGCTA GATTCTATCC TACCCACACT AAATATTTGC CC -#TTAGACAA 2940 - - AGGAATTAAA CCTTATTATC CAGATCAGGT AGTTAATCAT TACTTCCAAA CC -#AGACATTA 3000 - - TTTACATACT CTTTGGAAGG CTGGTATTCT ATATAAGCGG GAAACCACAC GT -#AGCGCATC 3060 - - ATTTTGCGGG TCACCAATGG AGCCAGTAGA TCCTAATCTA GAGCCCTGGA AG -#CATCCAGG 3120 - - AAGTCAGCCT AAAACTGCTT GTACCAATTG CTATTGTAAA AAGTGTTGCT TT -#CATTGCCA 3180 - - AGTTTGTTTC ATGACAAAAG CCTTAGGCAT CTCCTATGGC AGGAAGAAGC GG -#AGACAGCG 3240 - - ACGAAGAGCT CATCAGAACA GTCAGACTCA TCAAGCTTCT CTATCAAAGC AA -#CCCACCTC 3300 - - CCAATCCCGA GGGGACCCGA CAGGGCCCAC GGAAGGGTCA CCATATTCTT GG -#GAACAAGA 3360 - - GCTACAGCAT GGGAGGTTGG TCATCAAAAC CTCGCAAAGG CATGGGGACG AA -#TCTTTCTG 3420 - - TTCCCAATCC TCTGGGATTC TTTCCCGATC ATCAGTTGGA CCCTGCATTC GG -#AGCCAACT 3480 - - CAAACAATCC AGATTGGGAC TTCAACCCCG TCAAGGACGA CTGGCCAGCA GC -#CAACCAAG 3540 - - TAGGAGTGGG AGCATTCGGG CCAAGGCTCA CCCCTCCACA CGGCGGTATT TT -#GGGGTGGA 3600 - - GCCCTCAGGC TCAGGGCATA TTGACCACAG TGTCAACAAT TCCTCCTCCT GC -#CTCCACCA 3660 - - ATCGGCAGTC AGGAAGGCAG CCTACTCCCA TCTCTCCACC TCTAAGAGAC AG -#TCATCCTC 3720 - - AGGCCATGCA GTGGAATTCC ACTGCCTTCC ACCAAACTCT GCAGGATCCC AG -#AGTCAGGG 3780 - - GTCTGTATCT TCCTGCTGGT GGCTCCAGTT CAGGAACAGT AAACCCTGCT CC -#GAATATTG 3840 - - CCTCTCACAT CTCGTCAATC TCCGCGAGGA CTGGGGACCC TGTGACGAAC AT -#GGAGAACA 3900 - - TCACATCAGG ATTCCTAGGA CCCCTGCTCG TGTTACAGGC GGGGTTTTTC TT -#GTTGACAA 3960 - - GAATCCTCAC AATACCGCAG AGTCTAGACT CGTGGTGGAC TTCTCTCAAT TT -#TCTAGGGG 4020 - - GATCTCCCGT GTGTCTTGGC CAAAATTCGC AGTCCCCAAC CTCCAATCAC TC -#ACCAACCT 4080 - - CCTGTCCTCC AATTTGTCCT GGTTATCGCT GGATGTGTCT GCGGCGTTTT AT -#CATATTCC 4140 - - TCTTCATCCT GCTGCTATGC CTCATCTTCT TATTGGTTCT TCTGGATTAT CA -#AGGTATGT 4200 - - TGCCCGTTTG TCCTCTAATT CCAGGATCAA CAACAACCAG TACGGGACCA TG -#CAAAACCT 4260 - - GCACGACTCC TGCTCAAGGC AACTCTATGT TTCCCTCATG TTGCTGTACA AA -#ACCTACGG 4320 - - ATGGAAATTG CACCTGTATT CCCATCCCAT CGTCCTGGGC TTTCGCAAAA TA -#CCTATGGG 4380 - - AGTGGGCCTC AGTCCGTTTC TCTTGGCTCA GTTTACTAGT GCCATTTGTT CA -#GTGGTTCG 4440 - - TAGGGCTTTC CCCCACTGTT TGGCTTTCAG CTATATGGAT GATGTGGTAT TG -#GGGGCCAA 4500 - - GTCTGTACAG CATCGTGAGT CCCTTTATAC CGCTGTTACC AATTTTCTTT TG -#TCTCTGGG 4560 - - TATACATTTA AACCCTAACA AAACAAAAAG ATGGGGTTAT TCCCTAAACT TC -#ATGGGCTA 4620 - - CATAATTGGA AGTTGGGGAA CTTTGCCACA GGATCATATT GTACAAAAGA TC -#AAACACTG 4680 - - TTTTAGAAAA CTTCCTGTTA ACAGGCCTAT TGATTGGAAA GTATGTCAAA GA -#ATTGTGGG 4740 - - TCTTTTGGGC TTTGCTGCTC CATTTACACA ATGTGGATAT CCTGCCTTAA TG -#CCTTTGTA 4800 - - TGCATGTATA CAAGCTAAAC AGGCTTTCAC TTTCTCGCCA ACTTACAAGG CC -#TTTCTAAG 4860 - - TAAACAGTAC ATGAACCTTT ACCCCGTTGC TCGGCAACGG CCTGGTCTGT GC -#CAAGTGTT 4920 - - TGCTGACGCA ACCCCCACTG GCTGGGGCTT GGCCATAGGC CATCAGCGCA TG -#CGTGGAAC 4980 - - CTTTGTGGCT CCTCTGCCGA TCCATACTGC GGAACTCCTA GCCGCTTGTT TT -#GCTCGCAG 5040 - - CCGGTCTGGA GCAAAGCTCA TCGGAACTGA CAATTCTGTC GTCCTCTCGC GG -#AAATATAC 5100 - - ATCGTTTCCA TGGCTGCTAG GCTGTACTGC CAACTGGATC CTTCGCGGGA CG -#TCCTTTGT 5160 - - TTACGTCCCG TCGGCGCTGA ATCCCGCGGA CGACCCCTCT CGGGGCCGCT TG -#GGACTCTC 5220 - - TCGTCCCCTT CTCCGTCTGC CGTTCCAGCC GACCACGGGG CGCACCTCTC TT -#TACGCGGT 5280 - - CTCCCCGTCT GTGCCTTCTC ATCTGCCGGT CCGTGTGCAC TTCGCTTCAC CT -#CTGCACGT 5340 - - TGCATGGAGA CCACCGTGAA CGCCCATCAG ATCCTGCCCA AGGTCTTACA TA -#AGAGGACT 5400 - - CTTGGACTCC CAGCAATGTC AACGACCGAC CTTGAGGCCT ACTTCAAAGA CT -#GTGTGTTT 5460 - - AAGGACTGGG AGGAGCTGGG GGAGGAGATT AGGTTAAAGG TCTTTGTATT AG -#GAGGCTGT 5520 - - AGGCACAAAT TGGTCTGCGC ACCAGCACCA TGCAACTTTT TCACCTCTGC CT -#AATCATCT 5580 - - CTTGTACATG TCCCACTGTT CAAGCCTCCA AGCTGTGCCT TGGGTGGCTT TG -#GGGCATGG 5640 - - ACATTGACCC TTATAAAGAA TTTGGAGCTA CTGTGGAGTT ACTCTCGTTT TT -#GCCTTCTG 5700 - - ACTTCTTTCC TTCCGTCAGA GATCTCCTAG ACACCGCCTC AGCTCTGTAT CG -#AGAAGCCT 5760 - - TAGAGTCTCC TGAGCATTCC TCACCTCACC ATACTGCACT CAGGCAAGCC AT -#TCTCTGCT 5820 - - GGGGGGAATT GATGACTCTA GCTACCTGGG TGGGTAATAA TTTGGAAGAT CC -#AGCATCTA 5880 - - GGGATCTTGT AGTAAATTAT GTTAATACTA ACGTGGGTTT AAAGATCAGG CA -#ACTATTGT 5940 - - GGTTTCATAT ATCTTGCCTT ACTTTTGGAA GAGAGACTGT ACTTGAATAT TT -#GGTCTCTT 6000 - - TCGGAGTGTG GATTCGCACT CCTCCAGCCT ATAGACCACC AAATGCCCCT AT -#CTTATCAA 6060 - - CACTTCCGGA AACTACTGTT GTTAGACGAC GGGACCGAGG CAGGTCCCCT AG -#AAGAAGAA 6120 - - CTCCCTCGCC TCGCAGACGC AGATCTCCAT CGCCGCGTCG CAGAAGATCT CA -#ATCTCGGG 6180 - - AATCTCAATG TTAGTATTCC TTGGACTCAT AAGGTGGGAA ACTTTACGGG GC -#TTTATTCC 6240 - - TCTACAGTAC CTATCTTTAA TCCTGAATGG CAAACTCCTT CCTTTCCTAA GA -#TTCATTTA 6300 - - CAAGAGGACA TTATTAATAG GTGTCAACAA TTTGTGGGCC CTCTCACTGT AA -#ATGAAAAG 6360 - - AGAAGATTGA AATTAATTAT GCCTGCTAGA TTCTATCCTA CCCACACTAA AT -#ATTTGCCC 6420 - - TTAGACAAAG GAATTAAACC TTATTATCCA GATCAGGTAG TTAATCATTA CT -#TCCAAACC 6480 - - AGACATTATT TACATACTCT TTGGAAGGCT GGTATTCTAT ATAAGCGGGA AA -#CCACACGT 6540 - - AGCGCATCAT TTTGCGGGTC ACCAATGGAG CCAGTAGATC CTAATCTAGA GC -#CCTGGAAG 6600 - - CATCCAGGAA GTCAGCCTAA AACTGCTTGT ACCAATTGCT ATTGTAAAAA GT -#GTTGCTTT 6660 - - CATTGCCAAG TTTGTTTCAT GACAAAAGCC TTAGGCATCT CCTATGGCAG GA -#AGAAGCGG 6720 - - AGACAGCGAC GAAGAGCTCA TCAGAACAGT CAGACTCATC AAGCTTCTCT AT -#CAAAGCAA 6780 - - CCCACCTCCC AATCCCGAGG GGACCCGACA GGGCCCACGG AAGGGTCACC AT -#ATTCTTGG 6840 - - GAACAAGAGC TACAGCATGG GAGGTTGGTC ATCAAAACCT CGCAAAGGCA TG -#GGGACGAA 6900 - - TCTTTCTGTT CCCAATCCTC TGGGATTCTT TCCCGATCAT CAGTTGGACC CT -#GCATTCGG 6960 - - AGCCAACTCA AACAATCCAG ATTGGGACTT CAACCCCGTC AAGGACGACT GG -#CCAGCAGC 7020 - - CAACCAAGTA GGAGTGGGAG CATTCGGGCC AAGGCTCACC CCTCCACACG GC -#GGTATTTT 7080 - - GGGGTGGAGC CCTCAGGCTC AGGGCATATT GACCACAGTG TCAACAATTC CT -#CCTCCTGC 7140 - - CTCCACCAAT CGGCAGTCAG GAAGGCAGCC TACTCCCATC TCTCCACCTC TA -#AGAGACAG 7200 - - TCATCCTCAG GCCATGCAGT GGAATTCCCT ATAGTGAGTC GTATTAAATT CG -#TAATCATG 7260 - - GTCATAGCTG TTTCCTGTGT GAAATTGTTA TCCGCTCACA ATTCCACACA AC -#ATACGAGC 7320 - - CGGAAGCATA AAGTGTAAAG CCTGGGGTGC CTAATGAGTG AGCTAACTCA CA -#TTAATTGC 7380 - - GTTGCGCTCA CTGCCCGCTT TCCAGTCGGG AAACCTGTCG TGCCAGCTGC AT -#TAATGAAT 7440 - - CGGCCAACGC GCGGGGAGAG GCGGTTTGCG TATTGGGCGC TCTTCCGCTT CC -#TCGCTCAC 7500 - - TGACTCGCTG CGCTCGGTCG TTCGGCTGCG GCGAGCGGTA TCAGCTCACT CA -#AAGGCGGT 7560 - - AATACGGTTA TCCACAGAAT CAGGGGATAA CGCAGGAAAG AACATGTGAG CA -#AAAGGCCA 7620 - - GCAAAAGGCC AGGAACCGTA AAAAGGCCGC GTTGCTGGCG TTTTTCCATA GG -#CTCCGCCC 7680 - - CCCTGACGAG CATCACAAAA ATCGACGCTC AAGTCAGAGG TGGCGAAACC CG -#ACAGGACT 7740 - - ATAAAGATAC CAGGCGTTTC CCCCTGGAAG CTCCCTCGTG CGCTCTCCTG TT -#CCGACCCT 7800 - - GCCGCTTACC GGATACCTGT CCGCCTTTCT CCCTTCGGGA AGCGTGGCGC TT -#TCTCAATG 7860 - - CTCACGCTGT AGGTATCTCA GTTCGGTGTA GGTCGTTCGC TCCAAGCTGG GC -#TGTGTGCA 7920 - - CGAACCCCCC GTTCAGCCCG ACCGCTGCGC CTTATCCGGT AACTATCGTC TT -#GAGTCCAA 7980 - - CCCGGTAAGA CACGACTTAT CGCCACTGGC AGCAGCCACT GGTAACAGGA TT -#AGCAGAGC 8040 - - GAGGTATGTA GGCGGTGCTA CAGAGTTCTT GAAGTGGTGG CCTAACTACG GC -#TACACTAG 8100 - - AAGAACAGTA TTTGGTATCT GCGCTCTGCT GAAGCCAGTT ACCTTCGGAA AA -#AGAGTTGG 8160 - - TAGCTCTTGA TCCGGCAAAC AAACCACCGC TGGTAGCGGT GGTTTTTTTG TT -#TGCAAGCA 8220 - - GCAGATTACG CGCAGAAAAA AAGGATCTCA AGAAGATCCT TTGATCTTTT CT -#ACGGGGTC 8280 - - TGACGCTCAG TGGAACGAAA ACTCACGTTA AGGGATTTTG GTCATGAGAT TA -#TCAAAAAG 8340 - - GATCTTCACC TAGATCCTTT TAAATTAAAA ATGAAGTTTT AAATCAATCT AA -#AGTATATA 8400 - - TGAGTAAACT TGGTCTGACA GTTACCAATG CTTAATCAGT GAGGCACCTA TC -#TCAGCGAT 8460 - - CTGTCTATTT CGTTCATCCA TAGTTGCCTG ACTCCCCGTC GTGTAGATAA CT -#ACGATACG 8520 - - GGAGGGCTTA CCATCTGGCC CCAGTGCTGC AATGATACCG CGAGACCCAC GC -#TCACCGGC 8580 - - TCCAGATTTA TCAGCAATAA ACCAGCCAGC CGGAAGGGCC GAGCGCAGAA GT -#GGTCCTGC 8640 - - AACTTTATCC GCCTCCATCC AGTCTATTAA TTGTTGCCGG GAAGCTAGAG TA -#AGTAGTTC 8700 - - GCCAGTTAAT AGTTTGCGCA ACGTTGTTGC CATTGCTACA GGCATCGTGG TG -#TCACGCTC 8760 - - GTCGTTTGGT ATGGCTTCAT TCAGCTCCGG TTCCCAACGA TCAAGGCGAG TT -#ACATGATC 8820 - - CCCCATGTTG TGCAAAAAAG CGGTTAGCTC CTTCGGTCCT CCGATCGTTG TC -#AGAAGTAA 8880 - - GTTGGCCGCA GTGTTATCAC TCATGGTTAT GGCAGCACTG CATAATTCTC TT -#ACTGTCAT 8940 - - GCCATCCGTA AGATGCTTTT CTGTGACTGG TGAGTACTCA ACCAAGTCAT TC -#TGAGAATA 9000 - - GTGTATGCGG CGACCGAGTT GCTCTTGCCC GGCGTCAATA CGGGATAATA CC -#GCGCCACA 9060 - - TAGCAGAACT TTAAAAGTGC TCATCATTGG AAAACGTTCT TCGGGGCGAA AA -#CTCTCAAG 9120 - - GATCTTACCG CTGTTGAGAT CCAGTTCGAT GTAACCCACT CGTGCACCCA AC -#TGATCTTC 9180 - - AGCATCTTTT ACTTTCACCA GCGTTTCTGG GTGAGCAAAA ACAGGAAGGC AA -#AATGCCGC 9240 - - AAAAAAGGGA ATAAGGGCGA CACGGAAATG TTGAATACTC ATACTCTTCC TT -#TTTCAATA 9300 - - TTATTGAAGC ATTTATCAGG GTTATTGTCT CATGAGCGGA TACATATTTG AA -#TGTATTTA 9360 - - GAAAAATAAA CAAATAGGGG TTCCGCGCAC ATTTCCCCGA AAAGTGCCAC CT -#GAAATTGT 9420 - - AAACGTTAAT GTTTTGTTAA ATTTCGCGTT AAATATTTGT TAAATCAGCT TA -#TTTTTTAA 9480 - - CCAGTAAGCA GAAAATGACA AAAATCCTTA TAAATCAAAA GAATAGACCG AG -#TTAGTTGT 9540 - - GAGTGTTGTT CCAGTTTGGA ACAAGAGTCC ACTATTAAAG AACGTGGACT CC -#AACGTAAA 9600 - - ACCGTCTATC AGGGCGATGG CCCACTACGT GAACCATCAC CCAAATCAAG TT -#TTTGGAGG 9660 - - TCGAGGTGCC GTAAAGCACT AAATCGGAAC CCTAAAGGGA GCCCCCGATT TA -#GAGCTTGA 9720 - - CGGGGAAAGC CGGCGAACGT GGCGAGAAAG GAAGGGAAGA AAGCGAAAGG AG -#CGGGCGCT 9780 - - AGGGCGCTGG CAAGTGTAGC GGTCACGCTG CGCGTAACCA CCACACCCGC CG -#CGCTTAAT 9840 - - GCGCCGCTAC TGGGCGCGT - # - # 985 - #9 - - - - (2) INFORMATION FOR SEQ ID NO:7: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 36 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7: - - AAGGATCCTC GAGCCACCAT GGAGCCAGTA GATCCT - # -# 36 - - - - (2) INFORMATION FOR SEQ ID NO:8: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 32 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8: - - CAAGATCTGC ATGCTAATCG AACGGATCTG TC - # - # 32 - - - - (2) INFORMATION FOR SEQ ID NO:9: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 28 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9: - - TTACTAGTGC CATTTGTTCA GTGGTTCG - # - # 28 - - - - (2) INFORMATION FOR SEQ ID NO:10: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 21 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:10: - - GTGCACACGG ACCGGCAGAT G - # - # - #21 - - - - (2) INFORMATION FOR SEQ ID NO:11: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 48 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:11: - - ATACATCGTT TCCCTGGCTG CTAGGCTGTA CTGCTAACTG GATCCTTC - #48 - - - - (2) INFORMATION FOR SEQ ID NO:12: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 6371 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: circular - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12: - - CCCATTCGCC ATTCAGGCTG CGCAACTGTT GGGAAGGGCG ATCGGTGCGG GC -#CTCTTCGC 60 - - TATTACGCCA GCTGGCGAAA GGGGGATGTG CTGCAAGGCG ATTAAGTTGG GT -#AACGCCAG 120 - - GGTTTTCCCA GTCACGACGT TGTAAAACGA CGGCCAGTGC CAAGCTATAT AA -#ATTAACCC 180 - - TCACTAAAGG GAATAAGCTT GCATGCCTGC AGGTCGACTC TAGAGGATCC CC -#GGGTACCG 240 - - AGCTCGAATT CCACTGCCTT CCACCAAACT CTGCAGGATC CCAGAGTCAG GG -#GTCTGTAT 300 - - CTTCCTGCTG GTGGCTCCAG TTCAGGAACA GTAAACCCTG CTCCGAATAT TG -#CCTCTCAC 360 - - ATCTCGTCAA TCTCCGCGAG GACTGGGGAC CCTGTGACGA ACATGGAGAA CA -#TCACATCA 420 - - GGATTCCTAG GACCCCTGCT CGTGTTACAG GCGGGGTTTT TCTTGTTGAC AA -#GAATCCTC 480 - - ACAATACCGC AGAGTCTAGA CTCGTGGTGG ACTTCTCTCA ATTTTCTAGG GG -#GATCTCCC 540 - - GTGTGTCTTG GCCAAAATTC GCAGTCCCCA ACCTCCAATC ACTCACCAAC CT -#CCTGTCCT 600 - - CCAATTTGTC CTGGTTATCG CTGGATGTGT CTGCGGCGTT TTATCATATT CC -#TCTTCATC 660 - - CTGCTGCTAT GCCTCATCTT CTTATTGGTT CTTCTGGATT ATCAAGGTAT GT -#TGCCCGTT 720 - - TGTCCTCTAA TTCCAGGATC AACAACAACC AGTACGGGAC CATGCAAAAC CT -#GCACGACT 780 - - CCTGCTCAAG GCAACTCTAT GTTTCCCTCA TGTTGCTGTA CAAAACCTAC GG -#ATGGAAAT 840 - - TGCACCTGTA TTCCCATCCC ATCGTCCTGG GCTTTCGCAA AATACCTATG GG -#AGTGGGCC 900 - - TCAGTCCGTT TCTCTTGGCT CAGTTTACTA GTGCCATTTG TTCAGTGGTT CG -#TAGGGCTT 960 - - TCCCCCACTG TTTGGCTTTC AGCTATATGG ATGATGTGGT ATTGGGGGCC AA -#GTCTGTAC 1020 - - AGCATCGTGA GTCCCTTTAT ACCGCTGTTA CCAATTTTCT TTTGTCTCTG GG -#TATACATT 1080 - - TAAACCCTAA CAAAACAAAA AGATGGGGTT ATTCCCTAAA CTTCATGGGC TA -#CATAATTG 1140 - - GAAGTTGGGG AACTTTGCCA CAGGATCATA TTGTACAAAA GATCAAACAC TG -#TTTTAGAA 1200 - - AACTTCCTGT TAACAGGCCT ATTGATTGGA AAGTATGTCA AAGAATTGTG GG -#TCTTTTGG 1260 - - GCTTTGCTGC TCCATTTACA CAATGTGGAT ATCCTGCCTT AATGCCTTTG TA -#TGCATGTA 1320 - - TACAAGCTAA ACAGGCTTTC ACTTTCTCGC CAACTTACAA GGCCTTTCTA AG -#TAAACAGT 1380 - - ACATGAACCT TTACCCCGTT GCTCGGCAAC GGCCTGGTCT GTGCCAAGTG TT -#TGCTGACG 1440 - - CAACCCCCAC TGGCTGGGGC TTGGCCATAG GCCATCAGCG CATGCGTGGA AC -#CTTTGTGG 1500 - - CTCCTCTGCC GATCCATACT GCGGAACTCC TAGCCGCTTG TTTTGCTCGC AG -#CCGGTCTG 1560 - - GAGCAAAGCT CATCGGAACT GACAATTCTG TCGTCCTCTC GCGGAAATAT AC -#ATCGTTTC 1620 - - CTTGGCTGCT AGGCTGTACT GCTAACTGGA TCCTTCGCGG GACGTCCTTT GT -#TTACGTCC 1680 - - CGTCGGCGCT GAATCCCGCG GACGACCCCT CTCGGGGCCG CTTGGGACTC TC -#TCGTCCCC 1740 - - TTCTCCGTCT GCCGTTCCAG CCGACCACGG GGCGCACCTC TCTTTACGCG GT -#CTCCCCGT 1800 - - CTGTGCCTTC TCATCTGCCG GTCCGTGTGC ACTTCGCTTC ACCTCTGCAC GT -#TGCATGGA 1860 - - GACCACCGTG AACGCCCATC AGATCCTGCC CAAGGTCTTA CATAAGAGGA CT -#CTTGGACT 1920 - - CCCAGCAATG TCAACGACCG ACCTTGAGGC CTACTTCAAA GACTGTGTGT TT -#AAGGACTG 1980 - - GGAGGAGCTG GGGGAGGAGA TTAGGTTAAA GGTCTTTGTA TTAGGAGGCT GT -#AGGCACAA 2040 - - ATTGGTCTGC GCACCAGCAC CATGCAACTT TTTCACCTCT GCCTAATCAT CT -#CTTGTACA 2100 - - TGTCCCACTG TTCAAGCCTC CAAGCTGTGC CTTGGGTGGC TTTGGGGCAT GG -#ACATTGAC 2160 - - CCTTATAAAG AATTTGGAGC TACTGTGGAG TTACTCTCGT TTTTGCCTTC TG -#ACTTCTTT 2220 - - CCTTCCGTCA GAGATCTCCT AGACACCGCC TCAGCTCTGT ATCGAGAAGC CT -#TAGAGTCT 2280 - - CCTGAGCATT CCTCACCTCA CCATACTGCA CTCAGGCAAG CCATTCTCTG CT -#GGGGGGAA 2340 - - TTGATGACTC TAGCTACCTG GGTGGGTAAT AATTTGGAAG ATCCAGCATC TA -#GGGATCTT 2400 - - GTAGTAAATT ATGTTAATAC TAACGTGGGT TTAAAGATCA GGCAACTATT GT -#GGTTTCAT 2460 - - ATATCTTGCC TTACTTTTGG AAGAGAGACT GTACTTGAAT ATTTGGTCTC TT -#TCGGAGTG 2520 - - TGGATTCGCA CTCCTCCAGC CTATAGACCA CCAAATGCCC CTATCTTATC AA -#CACTTCCG 2580 - - GAAACTACTG TTGTTAGACG ACGGGACCGA GGCAGGTCCC CTAGAAGAAG AA -#CTCCCTCG 2640 - - CCTCGCAGAC GCAGATCTCC ATCGCCGCGT CGCAGAAGAT CTCAATCTCG GG -#AATCTCAA 2700 - - TGTTAGTATT CCTTGGACTC ATAAGGTGGG AAACTTTACG GGGCTTTATT CC -#TCTACAGT 2760 - - ACCTATCTTT AATCCTGAAT GGCAAACTCC TTCCTTTCCT AAGATTCATT TA -#CAAGAGGA 2820 - - CATTATTAAT AGGTGTCAAC AATTTGTGGG CCCTCTCACT GTAAATGAAA AG -#AGAAGATT 2880 - - GAAATTAATT ATGCCTGCTA GATTCTATCC TACCCACACT AAATATTTGC CC -#TTAGACAA 2940 - - AGGAATTAAA CCTTATTATC CAGATCAGGT AGTTAATCAT TACTTCCAAA CC -#AGACATTA 3000 - - TTTACATACT CTTTGGAAGG CTGGTATTCT ATATAAGCGG GAAACCACAC GT -#AGCGCATC 3060 - - ATTTTGCGGG TCACCAATGG AGCCAGTAGA TCCTAATCTA GAGCCCTGGA AG -#CATCCAGG 3120 - - AAGTCAGCCT AAAACTGCTT GTACCAATTG CTATTGTAAA AAGTGTTGCT TT -#CATTGCCA 3180 - - AGTTTGTTTC ATGACAAAAG CCTTAGGCAT CTCCTATGGC AGGAAGAAGC GG -#AGACAGCG 3240 - - ACGAAGAGCT CATCAGAACA GTCAGACTCA TCAAGCTTCT CTATCAAAGC AA -#CCCACCTC 3300 - - CCAATCCCGA GGGGACCCGA CAGGGCCCAC GGAAGGGTCA CCATATTCTT GG -#GAACAAGA 3360 - - GCTACAGCAT GGGAGGTTGG TCATCAAAAC CTCGCAAAGG CATGGGGACG AA -#TCTTTCTG 3420 - - TTCCCAATCC TCTGGGATTC TTTCCCGATC ATCAGTTGGA CCCTGCATTC GG -#AGCCAACT 3480 - - CAAACAATCC AGATTGGGAC TTCAACCCCG TCAAGGACGA CTGGCCAGCA GC -#CAACCAAG 3540 - - TAGGAGTGGG AGCATTCGGG CCAAGGCTCA CCCCTCCACA CGGCGGTATT TT -#GGGGTGGA 3600 - - GCCCTCAGGC TCAGGGCATA TTGACCACAG TGTCAACAAT TCCTCCTCCT GC -#CTCCACCA 3660 - - ATCGGCAGTC AGGAAGGCAG CCTACTCCCA TCTCTCCACC TCTAAGAGAC AG -#TCATCCTC 3720 - - AGGCCATGCA GTGGAATTCC CTATAGTGAG TCGTATTAAA TTCGTAATCA TG -#GTCATAGC 3780 - - TGTTTCCTGT GTGAAATTGT TATCCGCTCA CAATTCCACA CAACATACGA GC -#CGGAAGCA 3840 - - TAAAGTGTAA AGCCTGGGGT GCCTAATGAG TGAGCTAACT CACATTAATT GC -#GTTGCGCT 3900 - - CACTGCCCGC TTTCCAGTCG GGAAACCTGT CGTGCCAGCT GCATTAATGA AT -#CGGCCAAC 3960 - - GCGCGGGGAG AGGCGGTTTG CGTATTGGGC GCTCTTCCGC TTCCTCGCTC AC -#TGACTCGC 4020 - - TGCGCTCGGT CGTTCGGCTG CGGCGAGCGG TATCAGCTCA CTCAAAGGCG GT -#AATACGGT 4080 - - TATCCACAGA ATCAGGGGAT AACGCAGGAA AGAACATGTG AGCAAAAGGC CA -#GCAAAAGG 4140 - - CCAGGAACCG TAAAAAGGCC GCGTTGCTGG CGTTTTTCCA TAGGCTCCGC CC -#CCCTGACG 4200 - - AGCATCACAA AAATCGACGC TCAAGTCAGA GGTGGCGAAA CCCGACAGGA CT -#ATAAAGAT 4260 - - ACCAGGCGTT TCCCCCTGGA AGCTCCCTCG TGCGCTCTCC TGTTCCGACC CT -#GCCGCTTA 4320 - - CCGGATACCT GTCCGCCTTT CTCCCTTCGG GAAGCGTGGC GCTTTCTCAA TG -#CTCACGCT 4380 - - GTAGGTATCT CAGTTCGGTG TAGGTCGTTC GCTCCAAGCT GGGCTGTGTG CA -#CGAACCCC 4440 - - CCGTTCAGCC CGACCGCTGC GCCTTATCCG GTAACTATCG TCTTGAGTCC AA -#CCCGGTAA 4500 - - GACACGACTT ATCGCCACTG GCAGCAGCCA CTGGTAACAG GATTAGCAGA GC -#GAGGTATG 4560 - - TAGGCGGTGC TACAGAGTTC TTGAAGTGGT GGCCTAACTA CGGCTACACT AG -#AAGAACAG 4620 - - TATTTGGTAT CTGCGCTCTG CTGAAGCCAG TTACCTTCGG AAAAAGAGTT GG -#TAGCTCTT 4680 - - GATCCGGCAA ACAAACCACC GCTGGTAGCG GTGGTTTTTT TGTTTGCAAG CA -#GCAGATTA 4740 - - CGCGCAGAAA AAAAGGATCT CAAGAAGATC CTTTGATCTT TTCTACGGGG TC -#TGACGCTC 4800 - - AGTGGAACGA AAACTCACGT TAAGGGATTT TGGTCATGAG ATTATCAAAA AG -#GATCTTCA 4860 - - CCTAGATCCT TTTAAATTAA AAATGAAGTT TTAAATCAAT CTAAAGTATA TA -#TGAGTAAA 4920 - - CTTGGTCTGA CAGTTACCAA TGCTTAATCA GTGAGGCACC TATCTCAGCG AT -#CTGTCTAT 4980 - - TTCGTTCATC CATAGTTGCC TGACTCCCCG TCGTGTAGAT AACTACGATA CG -#GGAGGGCT 5040 - - TACCATCTGG CCCCAGTGCT GCAATGATAC CGCGAGACCC ACGCTCACCG GC -#TCCAGATT 5100 - - TATCAGCAAT AAACCAGCCA GCCGGAAGGG CCGAGCGCAG AAGTGGTCCT GC -#AACTTTAT 5160 - - CCGCCTCCAT CCAGTCTATT AATTGTTGCC GGGAAGCTAG AGTAAGTAGT TC -#GCCAGTTA 5220 - - ATAGTTTGCG CAACGTTGTT GCCATTGCTA CAGGCATCGT GGTGTCACGC TC -#GTCGTTTG 5280 - - GTATGGCTTC ATTCAGCTCC GGTTCCCAAC GATCAAGGCG AGTTACATGA TC -#CCCCATGT 5340 - - TGTGCAAAAA AGCGGTTAGC TCCTTCGGTC CTCCGATCGT TGTCAGAAGT AA -#GTTGGCCG 5400 - - CAGTGTTATC ACTCATGGTT ATGGCAGCAC TGCATAATTC TCTTACTGTC AT -#GCCATCCG 5460 - - TAAGATGCTT TTCTGTGACT GGTGAGTACT CAACCAAGTC ATTCTGAGAA TA -#GTGTATGC 5520 - - GGCGACCGAG TTGCTCTTGC CCGGCGTCAA TACGGGATAA TACCGCGCCA CA -#TAGCAGAA 5580 - - CTTTAAAAGT GCTCATCATT GGAAAACGTT CTTCGGGGCG AAAACTCTCA AG -#GATCTTAC 5640 - - CGCTGTTGAG ATCCAGTTCG ATGTAACCCA CTCGTGCACC CAACTGATCT TC -#AGCATCTT 5700 - - TTACTTTCAC CAGCGTTTCT GGGTGAGCAA AAACAGGAAG GCAAAATGCC GC -#AAAAAAGG 5760 - - GAATAAGGGC GACACGGAAA TGTTGAATAC TCATACTCTT CCTTTTTCAA TA -#TTATTGAA 5820 - - GCATTTATCA GGGTTATTGT CTCATGAGCG GATACATATT TGAATGTATT TA -#GAAAAATA 5880 - - AACAAATAGG GGTTCCGCGC ACATTTCCCC GAAAAGTGCC ACCTGAAATT GT -#AAACGTTA 5940 - - ATGTTTTGTT AAATTTCGCG TTAAATATTT GTTAAATCAG CTTATTTTTT AA -#CCAGTAAG 6000 - - CAGAAAATGA CAAAAATCCT TATAAATCAA AAGAATAGAC CGAGTTAGTT GT -#GAGTGTTG 6060 - - TTCCAGTTTG GAACAAGAGT CCACTATTAA AGAACGTGGA CTCCAACGTA AA -#ACCGTCTA 6120 - - TCAGGGCGAT GGCCCACTAC GTGAACCATC ACCCAAATCA AGTTTTTGGA GG -#TCGAGGTG 6180 - - CCGTAAAGCA CTAAATCGGA ACCCTAAAGG GAGCCCCCGA TTTAGAGCTT GA -#CGGGGAAA 6240 - - GCCGGCGAAC GTGGCGAGAA AGGAAGGGAA GAAAGCGAAA GGAGCGGGCG CT -#AGGGCGCT 6300 - - GGCAAGTGTA GCGGTCACGC TGCGCGTAAC CACCACACCC GCCGCGCTTA AT -#GCGCCGCT 6360 - - ACTGGGCGCG T - # - # - # 6371 - - - - (2) INFORMATION FOR SEQ ID NO:13: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 7463 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: circular - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13: - - GGCGTAATCT GCTGCTTGCA AACAAAAAAA CCACCGCTAC CAGCGGTGGT TT -#GTTTGCCG 60 - - GATCAAGAGC TACCAACTCT TTTTCCGAAG GTAACTGGCT TCAGCAGAGC GC -#AGATACCA 120 - - AATACTGTCC TTCTAGTGTA GCCGTAGTTA GGCCACCACT TCAAGAACTC TG -#TAGCACCG 180 - - CCTACATACC TCGCTCTGCT AATCCTGTTA CCAGTGGCTG CTGCCAGTGG CG -#ATAAGTCG 240 - - TGTCTTACCG GGTTGGACTC AAGACGATAG TTACCGGATA AGGCGCAGCG GT -#CGGGCTGA 300 - - ACGGGGGGTT CGTGCACACA GCCCAGCTTG GAGCGAACGA CCTACACCGA AC -#TGAGATAC 360 - - CTACAGCGTG AGCATTGAGA AAGCGCCACG CTTCCCGAAG GGAGAAAGGC GG -#ACAGGTAT 420 - - CCGGTAAGCG GCAGGGTCGG AACAGGAGAG CGCACGAGGG AGCTTCCAGG GG -#GAAACGCC 480 - - TGGTATCTTT ATAGTCCTGT CGGGTTTCGC CACCTCTGAC TTGAGCGTCG AT -#TTTTGTGA 540 - - TGCTCGTCAG GGGGGCGGAG CCTATGGAAA AACGCCAGCA ACGCAAGCTA GC -#TTCTAGCT 600 - - AGAAATTGTA AACGTTAATA TTTTGTTAAA ATTCGCGTTA AATTTTTGTT AA -#ATCAGCTC 660 - - ATTTTTTAAC CAATAGGCCG AAATCGGCAA AATCCCTTAT AAATCAAAAG AA -#TAGCCCGA 720 - - GATAGGGTTG AGTGTTGTTC CAGTTTGGAA CAAGAGTCCA CTATTAAAGA AC -#GTGGACTC 780 - - CAACGTCAAA GGGCGAAAAA CCGTCTATCA GGGCGATGGC CGCCCACTAC GT -#GAACCATC 840 - - ACCCAAATCA AGTTTTTTGG GGTCGAGGTG CCGTAAAGCA CTAAATCGGA AC -#CCTAAAGG 900 - - GAGCCCCCGA TTTAGAGCTT GACGGGGAAA GCCGGCGAAC GTGGCGAGAA AG -#GAAGGGAA 960 - - GAAAGCGAAA GGAGCGGGCG CTAGGGCGCT GGCAAGTGTA GCGGTCACGC TG -#CGCGTAAC 1020 - - CACCACACCC GCCGCGCTTA ATGCGCCGCT ACAGGGCGCG TACTATGGTT GC -#TTTGACGA 1080 - - GACCGTATAA CGTGCTTTCC TCGTTGGAAT CAGAGCGGGA GCTAAACAGG AG -#GCCGATTA 1140 - - AAGGGATTTT AGACAGGAAC GGTACGCCAG CTGGATTACC AAAGGGCCTC GT -#GATACGCC 1200 - - TATTTTTATA GGTTAATGTC ATGATAATAA TGGTTTCTTA GACGTCAGGT GG -#CACTTTTC 1260 - - GGGGAAATGT GCGCGGAACC CCTATTTGTT TATTTTTCTA AATACATTCA AA -#TATGTATC 1320 - - CGCTCATGAG ACAATAACCC TGATAAATGC TTCAATAATA TTGAAAAAGG AA -#GAGTATGA 1380 - - GTATTCAACA TTTCCGTGTC GCCCTTATTC CCTTTTTTGC GGCATTTTGC CT -#TCCTGTTT 1440 - - TTGCTCACCC AGAAACGCTG GTGAAAGTAA AAGATGCTGA AGATCAGTTG GG -#TGCACGAG 1500 - - TGGGTTACAT CGAACTGGAT CTCAACAGCG GTAAGATCCT TGAGAGTTTT CG -#CCCCGAAG 1560 - - AACGTTTTCC AATGATGAGC ACTTTTAAAG TTCTGCTATG TGGCGCGGTA TT -#ATCCCGTG 1620 - - TTGACGCCGG GCAAGAGCAA CTCGGTCGCC GCATACACTA TTCTCAGAAT GA -#CTTGGTTG 1680 - - AGTACTCACC AGTCACAGAA AAGCATCTTA CGGATGGCAT GACAGTAAGA GA -#ATTATGCA 1740 - - GTGCTGCCAT AACCATGAGT GATAACACTG CGGCCAACTT ACTTCTGACA AC -#GATCGGAG 1800 - - GACCGAAGGA GCTAACCGCT TTTTTGCACA ACATGGGGGA TCATGTAACT CG -#CCTTGATC 1860 - - GTTGGGAACC GGAGCTGAAT GAAGCCATAC CAAACGACGA GCGTGACACC AC -#GATGCCTG 1920 - - CAGCAATGGC AACAACGTTG CGCAAACTAT TAACTGGCGA ACTACTTACT CT -#AGCTTCCC 1980 - - GGCAACAATT AATAGACTGG ATGGAGGCGG ATAAAGTTGC AGGACCACTT CT -#GCGCTCGG 2040 - - CCCTTCCGGC TGGCTGGTTT ATTGCTGATA AATCTGGAGC CGGTGAGCGT GG -#GTCTCGCG 2100 - - GTATCATTGC AGCACTGGGG CCAGATGGTA AGCCCTCCCG TATCGTAGTT AT -#CTACACGA 2160 - - CGGGGAGTCA GGCAACTATG GATGAACGAA ATAGACAGAT CGCTGAGATA GG -#TGCCTCAC 2220 - - TGATTAAGCA TTGGTAACTG TCAGACCAAG TTTACTCATA TATACTTTAG AT -#TGATTTAA 2280 - - AACTTCATTT TTAATTTCTC TAGCGCGTTG ACATTGATTA TTGACTAGTT AT -#TAATAGTA 2340 - - ATCAATTACG GGGTCATTAG TTCATAGCCC ATATATGGAG TTCCGCGTTA CA -#TAACTTAC 2400 - - GGTAAATGGC CCGCCTGGCT GACCGCCCAA CGACCCCCGC CCATTGACGT CA -#ATAATGAC 2460 - - GTATGTTCCC ATAGTAACGC CAATAGGGAC TTTCCATTGA CGTCAATGGG TG -#GACTATTT 2520 - - ACGGTAAACT GCCCACTTGG CAGTACATCA AGTGTATCAT ATGCCAAGTA CG -#CCCCCTAT 2580 - - TGACGTCAAT GACGGTAAAT GGCCCGCCTG GCATTATGCC CAGTACATGA CC -#TTATGGGA 2640 - - CTTTCCTACT TGGCAGTACA TCTACGTATT AGTCATCGCT ATTACCATGG TG -#ATGCGGTT 2700 - - TTGGCAGTAC ATCAATGGGC GTGGATAGCG GTTTGACTCA CGGGGATTTC CA -#AGTCTCCA 2760 - - CCCCATTGAC GTCAATGGGA GTTTGTTTTG GCACCAAAAT CAACGGGACT TT -#CCAAAATG 2820 - - TCGTAACAAC TCCGCCCCAT TGACGCAAAT GGGCGGTAGG CGTGTACGGT GG -#GAGGTCTA 2880 - - TATAAGCAGA GCTCTCTGGC TAACTAGAGA ACCCACTGCT TACTGGCTTA TC -#GAAATTAA 2940 - - TACGACTCAC TATAGGGAGA CCCAAGCTTG CATGCCTGCA GGCAACTCTT GT -#GGTTTCGT 3000 - - ATCTCTTACC TTACTTTTGG AAGAGAAACT GTACTTGAAT ATTTGGTCTC TT -#TCGGAGTG 3060 - - TGGATTCGCA CTCCTCCAGC CTATAGACCA CCAAATGCCC CTATCTTATC AA -#CACTTCCG 3120 - - GAAACTACTG TTGTTAGACG ACGGGACCGA GGCAGGTCCC CTAGAAGAAG AA -#CTCCCTCG 3180 - - CCTCGCAGAC GCAGATCTCA ATCGCCGCGT CGCAGAAGAT CTCAATCTCG GG -#AATCTCAA 3240 - - TGTTAGTATT CCTTGGACTC ATAAGGTGGG AAACTTCACT GGGCTTTATT CC -#TCTACAGC 3300 - - ACCTATCTTT AATCCTGAAT GGCAAACTCC TTCCTTTCCT AAAATTCATT TA -#CAAGAGGA 3360 - - CATTATTAAT AGGTGTCAAC AATTTGTGGG CCCTCTCACT GTAAATGAAA AG -#AGAAGATT 3420 - - GAAATTAATT ATGCCTGCTA GATTCTATCC TACCCACACT AAATATTTGC CC -#TTAGACAA 3480 - - AGGAATTAAA CCTTATTATC CAGATCAGGT AGTTAATCAT TACTTCCAAA CC -#AGACATTA 3540 - - TTTACATACT CTTTGGAAGG CGGGTATTCT ATATAAGAGA GAAACCACAC GT -#AGCGCATC 3600 - - ATTTTGCGGG TCACCATATT CTTGGGAACA AGAGCTACAG CATGGGAGGT TG -#GTCATCAA 3660 - - AACCTCGCAA AGGCATGGGG ACGAATCTTT CTGTTCCCAA CCCTCTGGGA TT -#CTTTCCCG 3720 - - ATCATCAGTT GGACCCTGTA TTCGGAGCCA ACTCAAACAA TCCAGATTGG GA -#CTTCAACC 3780 - - CCATCAAGGA CCACTGGCCA GCAGCCAACC AGGTAGGAGT GGGAGCATTC GG -#GCCAGGGT 3840 - - TCACCCCTCC ACACGGCGGT GTTTTGGGGT GGAGCCCTCA GGCTCAGGGC AT -#GTTGACCC 3900 - - CAGTGTCAAC AATTCCTCCT CCTGCCTCCG CCAATCGGCA GTCAGGAAGG CA -#GCCTACTC 3960 - - CCATCTCTCC ACCTCTAAGA GACAGTCATC CTCAGGCCAT GCAGTGGAAT TC -#CACTGCCT 4020 - - TCCACCAAGC TCTGCAAGAC CCCAGAGTCA GGGGTCTGTA TTTTCCTGCT GG -#TGGCTCCA 4080 - - GTTCAGGAAC AGTAAACCCT GCTCCGAATA TTGCCTCTCA CATCTCGTCA AT -#CTCCGCGA 4140 - - GGACCGGGGA CCCTGTGACG AACATGGAGA ACATCACATC AGGATTCCTA GG -#ACCCCTGC 4200 - - CCGTGTTACA GGCGGGGTTT TTCTTGTTGA CAAGAATCCT CACAATACCG CA -#GAGTCTAG 4260 - - ACTCGTGGTG GACTTCTCTC AATTTTCTAG GGGGATCACC CGTGTGTCTT GG -#CCAAAATT 4320 - - CGCGATCCCC AACCTCCAAT CACTCACCAA CCTCCTGTCC TCCAATTTGT CC -#TGGTTATC 4380 - - GCTGGATGTG TCTGCGGCGT TTTATCATAT TCCTCTTCAT CCTGCTGCTA TG -#CCTCATCT 4440 - - TCTTATTGGT TCTTCTGGAT TATCAAGGTA TGTTGCCCGT TTGTCCTCTA AT -#TCTAGGAT 4500 - - CAACAACAAC CAGTACGGGA CCATGCAAAA CCTGCACGAC TCCTGCTCAA GG -#CAACTCTA 4560 - - TGTTTCCCTC ATGTTGCTGT ACAAAACCTA CGGATGGAAA TTGCACCTGT AT -#TCCCATCC 4620 - - CATCGTCTTG GGCTTTCGCA AAATACCTAT GGGAGTGGGC CTCAGTCCGT TT -#CTCTTGGC 4680 - - TCAGTTTACT AGTGCCATTT GTTCAGTGGT TCGTAGGGCT TTCCCCCACT GT -#TTGGCTTT 4740 - - CAGCTATATG GATGATGTGG TATTGGGGGC CAAGTCTGTA CAGCATCGTG AG -#TTCCTTTA 4800 - - TACCGCTGTT ACCAATTTTC TTTTGTCTCT GGGTATACAT TTAAACCCTA AC -#AAAACAAA 4860 - - AAGATGGGGT TATTCCCTAA ACTTCATGGG TTATGTAATT GGAAGTTGGG GA -#ACATTGCC 4920 - - ACAGGATCAT ATTGTACAAA AAATCAAACA CTGTTTTAGA AAACTTCCTG TT -#AACAGGCC 4980 - - TATTGATTGG AAAGTATGTC AAAGAATTGT GGGTCTTTTG GGCTTTGCTG CT -#CCTTTTAC 5040 - - ACAATGTGGA TATCCTGCCT TAATGCCCTT GTATGCATGT ATACAAGCTA AA -#CAGGCTTT 5100 - - CACTTTCTCG CCAACTTACA AGGCCTTTCT AAGTAAACAG TACATGAACC TT -#TACCCCGT 5160 - - TGCTCGGCAA CGGCCTGGTC TGTGCCAAGT ATTTGCTGAT GCAACCCCCA CT -#GGCTGGGG 5220 - - CTTGGCCATA GGCCATCAGC GCATGCGCGG AACCTTTGTG GCTCCTCTGC CG -#ATCCATAC 5280 - - TGCGGAACTC CTAGCCGCTT GTTTTGCTCG CAGCCGGTCT GGAGCGAAAC TC -#ATCGGAAC 5340 - - TGACAATTCT GTCGTCCTCT CGCGGAAATA TACCTCGTTT CCATGGCTAC TA -#GGCTGTGC 5400 - - TGCCAACTGG ATCCTTCGCG GGACGTCCTT TGTTTACGTC CCGTCGGCGC TG -#AATCCCGC 5460 - - GGACGACCCC TCTCGGGGCC GCTTGGGACT CTCTCGTCCC CTTCTCCGTC TG -#CCGTTCCA 5520 - - GCCGACCACG GGGCGCACCT CTCTTTACGC GGTCTCCCCG TCTGTGCCTT CT -#CATCTGCC 5580 - - GGTCCGTGTG CACTTCGCTT CACCTCTGCA CGTTGCATGG AGACCACCGT GA -#ACGCCCAT 5640 - - CAGATCCTGC CCAAGGTCTT ACATAAGAGG ACTCTTGGAC TCCCCCCATC CA -#TCACACTG 5700 - - GCGGCCGCTC GAGCATGCAT CTAGAGGGCC CTATTCTATA GTGTCACCTA AA -#TGCTAGAG 5760 - - GATCTTTGTG AAGGAACCTT ACTTCTGTGG TGTGACATAA TTGGACAAAC TA -#CCTACAGA 5820 - - GATTTAAAGC TCTAAGGTAA ATATAAAATT TTTAAGTGTA TAATGTGTTA AA -#CTACTGAT 5880 - - TCTAATTGTT TGTGTATTTT AGATTCCAAC CTATGGAACT GATGAATGGG AG -#CAGTGGTG 5940 - - GAATGCCTTT AATGAGGAAA ACCTGTTTTG CTCAGAAGAA ATGCCATCTA GT -#GATGATGA 6000 - - GGCTACTGCT GACTCTCAAC ATTCTACTCC TCCAAAAAAG AAGAGAAAGG TA -#GAAGACCC 6060 - - CAAGGACTTT CCTTCAGAAT TGCTAAGTTT TTTGAGTCAT GCTGTGTTTA GT -#AATAGAAC 6120 - - TCTTGCTTGC TTTGCTATTT ACACCACAAA GGAAAAAGCT GCACTGCTAT AC -#AAGAAAAT 6180 - - TATGGAAAAA TATTTGATGT ATAGTGCCTT GACTAGAGAT CATAATCAGC CA -#TACCACAT 6240 - - TTGTAGAGGT TTTACTTGCT TTAAAAAACC TCCCACACCT CCCCCTGAAC CT -#GAAACATA 6300 - - AAATGAATGC AATTGTTGTT GTTAACTTGT TTATTGCAGC TTATAATGGT TA -#CAAATAAA 6360 - - GCAATAGCAT CACAAATTTC ACAAATAAAG CATTTTTTTC ACTGCATTCT AG -#TTGTGGTT 6420 - - TGTCCAAACT CATCAATGTA TCTTATCATG TCTGGATCAT CCCGCCATGG TA -#TCAACGCC 6480 - - ATATTTCTAT TTACAGTAGG GACCTCTTCG TTGTGTAGGT ACCGCTGTAT TC -#CTAGGGAA 6540 - - ATAGTAGAGG CACCTTGAAC TGTCTGCATC AGCCATATAG CCCCCGCTGT TC -#GACTTACA 6600 - - AACACAGGCA CAGTACTGAC AAACCCATAC ACCTCCTCTG AAATACCCAT AG -#TTGCTAGG 6660 - - GCTGTCTCCG AACTCATTAC ACCCTCCAAA GTCAGAGCTG TAATTTCGCC AT -#CAAGGGCA 6720 - - GCGAGGGCTT CTCCAGATAA AATAGCTTCT GCCGAGAGTC CCGTAAGGGT AG -#ACACTTCA 6780 - - GCTAATCCCT CGATGAGGTC TACTAGAATA GTCAGTGCGG CTCCCATTTT GA -#AAATTCAC 6840 - - TTACTTGATC AGCTTCAGAA GATGGCGGAG GGCCTCCAAC ACAGTAATTT TC -#CTCCCGAC 6900 - - TCTTAAAATA GAAAATGTCA AGTCAGTTAA GCAGGAAGTG GACTAACTGA CG -#CAGCTGGC 6960 - - CGTGCGACAT CCTCTTTTAA TTAGTTGCTA GGCAACGCCC TCCAGAGGGC GT -#GTGGTTTT 7020 - - GCAAGAGGAA GCAAAAGCCT CTCCACCCAG GCCTAGAATG TTTCCACCCA AT -#CATTACTA 7080 - - TGACAACAGC TGTTTTTTTT AGTATTAAGC AGAGGCCGGG GACCCCTGGG CC -#CGCTTACT 7140 - - CTGGAGAAAA AGAAGAGAGG CATTGTAGAG GCTTCCAGAG GCAACTTGTC AA -#AACAGGAC 7200 - - TGCTTCTATT TCTGTCACAC TGTCTGGCCC TGTCACAAGG TCCAGCACCT CC -#ATACCCCC 7260 - - TTTAATAAGC AGTTTGGGAA CGGGTGCGGG TCTTACTCCG CCCATCCCGC CC -#CTAACTCC 7320 - - GCCCAGTTCC GCCCATTCTC CGCCCCATGG CTGACTAATT TTTTTTATTT AT -#GCAGAGGC 7380 - - CGAGGCCGCC TCGGCCTCTG AGCTATTCCA GAAGTAGTGA GGAGGCTTTT TT -#GGAGGCCT 7440 - - AGGCTTTTGC AAAAAGCTAA TTC - # - # 7463 - - - - (2) INFORMATION FOR SEQ ID NO:14: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 6375 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: circular - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:14: - - CCCATTCGCC ATTCAGGCTG CGCAACTGTT GGGAAGGGCG ATCGGTGCGG GC -#CTCTTCGC 60 - - TATTACGCCA GCTGGCGAAA GGGGGATGTG CTGCAAGGCG ATTAAGTTGG GT -#AACGCCAG 120 - - GGTTTTCCCA GTCACGACGT TGTAAAACGA CGGCCAGTGC CAAGCTATAT AA -#ATTAACCC 180 - - TCACTAAAGG GAATAAGCTT GCATGCCTGC AGGTCGACTC TAGAGGATCC CC -#GGGTACCG 240 - - AGCTCGAATT CCACTGCCTT CCACCAAACT CTGCAGGATC CCAGAGTCAG GG -#GTCTGTAT 300 - - CTTCCTGCTG GTGGCTCCAG TTCAGGAACA GTAAACCCTG CTCCGAATAT TG -#CCTCTCAC 360 - - ATCTCGTCAA TCTCCGCGAG GACTGGGGAC CCTGTGACGA ACATGGAGAA CA -#TCACATCA 420 - - GGATTCCTAG GACCCCTGCT CGTGTTACAG GCGGGGTTTT TCTTGTTGAC AA -#GAATCCTC 480 - - ACAATACCGC AGAGTCTAGA CTCGTGGTGG ACTTCTCTCA ATTTTCTAGG GG -#GATCTCCC 540 - - GTGTGTCTTG GCCAAAATTC GCAGTCCCCA ACCTCCAATC ACTCACCAAC CT -#CCTGTCCT 600 - - CCAATTTGTC CTGGTTATCG CTGGATGTGT CTGCGGCGTT TTATCATATT CC -#TCTTCATC 660 - - CTGCTGCTAT GCCTCATCTT CTTATTGGTT CTTCTGGATT ATCAAGGTAT GT -#TGCCCGTT 720 - - TGTCCTCTAA TTCCAGGATC AACAACAACC AGTACGGGAC CATGCAAAAC CT -#GCACGACT 780 - - CCTGCTCAAG GCAACTCTAT GTTTCCCTCA TGTTGCTGTA CAAAACCTAC GG -#ATGGAAAT 840 - - TGCACCTGTA TTCCCATCCC ATCGTCCTGG GCTTTCGCAA AATACCTATG GG -#AGTGGGCC 900 - - TCAGTCCGTT TCTCTTGGCT CAGTTTACTA GTGCCATTTG TTCAGTGGTT CG -#TAGGGCTT 960 - - TCCCCCACTG TTTGGCTTTC AGCTATATGG ATGATGTGGT ATTGGGGGCC AA -#GTCTGTAC 1020 - - AGCATCGTGA GTCCCTTTAT ACCGCTGTTA CCAATTTTCT TTTGTCTCTG GG -#TATACATT 1080 - - TAAACCCTAA CAAAACAAAA AGATGGGGTT ATTCCCTAAA CTTCATGGGC TA -#CATAATTG 1140 - - GAAGTTGGGG AACTTTGCCA CAGGATCATA TTGTACAAAA GATCAAACAC TG -#TTTTAGAA 1200 - - AACTTCCTGT TAACAGGCCT ATTGATTGGA AAGTATGTCA AAGAATTGTG GG -#TCTTTTGG 1260 - - GCTTTGCTGC TCCATTTACA CAATGTGGAT ATCCTGCCTT AATGCCTTTG TA -#TGCATGTA 1320 - - TACAAGCTAA ACAGGCTTTC ACTTTCTCGC CAACTTACAA GGCCTTTCTA AG -#TAAACAGT 1380 - - ACATGAACCT TTACCCCGTT GCTCGGCAAC GGCCTGGTCT GTGCCAAGTG TT -#TGCTGACG 1440 - - CAACCCCCAC TGGCTGGGGC TTGGCCATAG GCCATCAGCG CATGCGTGGA AC -#CTTTGTGG 1500 - - CTCCTCTGCC GATCCATACT GCGGAACTCC TAGCCGCTTG TTTTGCTCGC AG -#CCGGTCTG 1560 - - GAGCAAAGCT CATCGGAACT GACAATTCTG TCGTCCTCTC GCGGAAATAT AC -#ATCGTTTC 1620 - - CATGGCTGCT AGGCTGTACT GCCAACTGGA TCCTTCGCGG GACGTCCTTT GT -#TTACGTCC 1680 - - CGTCGGCGCT GAATCCCGCG GACGACCCCT CTCGGGGCCG CTTGGGACTC TC -#TCGTCCCC 1740 - - TTCTCCGTCT GCCGTTCCAG CCGACCACGG GGCGCACCTC TCTTTACGCG GT -#CTCCCCGT 1800 - - CTGTGCCTTC TCATCTGCCG GTCCGTGTGC ACTTCGCTTC ACCTCTGCAC GT -#TGCATGGA 1860 - - GACCACCGTG AACGCCCATC AGATCCTGCC CAAGGTCTTA CATAAGAGGA CT -#CTTGGACT 1920 - - CCCAGCAATG TCAACGACCG ACCTTGAGGC CTACTTCAAA GACTGTGTGT TT -#AAGGACTG 1980 - - GGAGGAGCTG GGGGAGGAGA TTAGGTTAAA GGTCTTTGTA TTAGGAGGCT GT -#AGGCACAA 2040 - - ATTGGTCTGC GCACCAGCAC CATGCAACTT TTTCACCTCT GCCTAATCAT CT -#CTTGTACA 2100 - - TGTCCCACTG TTCAAGCCTC CAAGCTGTGC CTTGGGTGGC TTTGGGGCAT GG -#ACATTGAC 2160 - - CCTTATAAAG AATTTGGAGC TACTGTGGAG TTACTCTCGT TTTTGCCTTC TG -#ACTTCTTT 2220 - - CCTTCCGTCA GAGATCTCCT AGACACCGCC TCAGCTCTGT ATCGAGAAGC CT -#TAGAGTCT 2280 - - CCTGAGCATT CCTCACCTCA CCATACTGCA CTCAGGCAAG CCATTCTCTG CT -#GGGGGGAA 2340 - - TTGATGACTC TAGCTACCTG GGTGGGTAAT AATTTGGAAG ATCCAGCATC TA -#GGGATCTT 2400 - - GTAGTAAATT ATGTTAATAC TAACGTGGGT TTAAAGATCA GGCAACTATT GT -#GGTTTCAT 2460 - - ATATCTTGCC TTACTTTTGG AAGAGAGACT GTACTTGAAT ATTTGGTCTC TT -#TCGGAGTG 2520 - - TGGATTCGCA CTCCTCCAGC CTATAGACCA CCAAATGCCC CTATCTTATC AA -#CACTTCCG 2580 - - GCCGGAAACT ACTGTTGTTA GACGACGGGA CCGAGGCAGG TCCCCTAGAA GA -#AGAACTCC 2640 - - CTCGCCTCGC AGACGCAGAT CTCCATCGCC GCGTCGCAGA AGATCTCAAT CT -#CGGGAATC 2700 - - TCAATGTTAG TATTCCTTGG ACTCATAAGG TGGGAAACTT TACGGGGCTT TA -#TTCCTCTA 2760 - - CAGTACCTAT CTTTAATCCT GAATGGCAAA CTCCTTCCTT TCCTAAGATT CA -#TTTACAAG 2820 - - AGGACATTAT TAATAGGTGT CAACAATTTG TGGGCCCTCT CACTGTAAAT GA -#AAAGAGAA 2880 - - GATTGAAATT AATTATGCCT GCTAGATTCT ATCCTACCCA CACTAAATAT TT -#GCCCTTAG 2940 - - ACAAAGGAAT TAAACCTTAT TATCCAGATC AGGTAGTTAA TCATTACTTC CA -#AACCAGAC 3000 - - ATTATTTACA TACTCTTTGG AAGGCTGGTA TTCTATATAA GCGGGAAACC AC -#ACGTAGCG 3060 - - CATCATTTTG CGGGTCACCA ATGGAGCCAG TAGATCCTAA TCTAGAGCCC TG -#GAAGCATC 3120 - - CAGGAAGTCA GCCTAAAACT GCTTGTACCA ATTGCTATTG TAAAAAGTGT TG -#CTTTCATT 3180 - - GCCAAGTTTG TTTCATGACA AAAGCCTTAG GCATCTCCTA TGGCAGGAAG AA -#GCGGAGAC 3240 - - AGCGACGAAG AGCTCATCAG AACAGTCAGA CTCATCAAGC TTCTCTATCA AA -#GCAACCCA 3300 - - CCTCCCAATC CCGAGGGGAC CCGACAGGGC CCACGGAAGG GTCACCATAT TC -#TTGGGAAC 3360 - - AAGAGCTACA GCATGGGAGG TTGGTCATCA AAACCTCGCA AAGGCATGGG GA -#CGAATCTT 3420 - - TCTGTTCCCA ATCCTCTGGG ATTCTTTCCC GATCATCAGT TGGACCCTGC AT -#TCGGAGCC 3480 - - AACTCAAACA ATCCAGATTG GGACTTCAAC CCCGTCAAGG ACGACTGGCC AG -#CAGCCAAC 3540 - - CAAGTAGGAG TGGGAGCATT CGGGCCAAGG CTCACCCCTC CACACGGCGG TA -#TTTTGGGG 3600 - - TGGAGCCCTC AGGCTCAGGG CATATTGACC ACAGTGTCAA CAATTCCTCC TC -#CTGCCTCC 3660 - - ACCAATCGGC AGTCAGGAAG GCAGCCTACT CCCATCTCTC CACCTCTAAG AG -#ACAGTCAT 3720 - - CCTCAGGCCA TGCAGTGGAA TTCCCTATAG TGAGTCGTAT TAAATTCGTA AT -#CATGGTCA 3780 - - TAGCTGTTTC CTGTGTGAAA TTGTTATCCG CTCACAATTC CACACAACAT AC -#GAGCCGGA 3840 - - AGCATAAAGT GTAAAGCCTG GGGTGCCTAA TGAGTGAGCT AACTCACATT AA -#TTGCGTTG 3900 - - CGCTCACTGC CCGCTTTCCA GTCGGGAAAC CTGTCGTGCC AGCTGCATTA AT -#GAATCGGC 3960 - - CAACGCGCGG GGAGAGGCGG TTTGCGTATT GGGCGCTCTT CCGCTTCCTC GC -#TCACTGAC 4020 - - TCGCTGCGCT CGGTCGTTCG GCTGCGGCGA GCGGTATCAG CTCACTCAAA GG -#CGGTAATA 4080 - - CGGTTATCCA CAGAATCAGG GGATAACGCA GGAAAGAACA TGTGAGCAAA AG -#GCCAGCAA 4140 - - AAGGCCAGGA ACCGTAAAAA GGCCGCGTTG CTGGCGTTTT TCCATAGGCT CC -#GCCCCCCT 4200 - - GACGAGCATC ACAAAAATCG ACGCTCAAGT CAGAGGTGGC GAAACCCGAC AG -#GACTATAA 4260 - - AGATACCAGG CGTTTCCCCC TGGAAGCTCC CTCGTGCGCT CTCCTGTTCC GA -#CCCTGCCG 4320 - - CTTACCGGAT ACCTGTCCGC CTTTCTCCCT TCGGGAAGCG TGGCGCTTTC TC -#AATGCTCA 4380 - - CGCTGTAGGT ATCTCAGTTC GGTGTAGGTC GTTCGCTCCA AGCTGGGCTG TG -#TGCACGAA 4440 - - CCCCCCGTTC AGCCCGACCG CTGCGCCTTA TCCGGTAACT ATCGTCTTGA GT -#CCAACCCG 4500 - - GTAAGACACG ACTTATCGCC ACTGGCAGCA GCCACTGGTA ACAGGATTAG CA -#GAGCGAGG 4560 - - TATGTAGGCG GTGCTACAGA GTTCTTGAAG TGGTGGCCTA ACTACGGCTA CA -#CTAGAAGA 4620 - - ACAGTATTTG GTATCTGCGC TCTGCTGAAG CCAGTTACCT TCGGAAAAAG AG -#TTGGTAGC 4680 - - TCTTGATCCG GCAAACAAAC CACCGCTGGT AGCGGTGGTT TTTTTGTTTG CA -#AGCAGCAG 4740 - - ATTACGCGCA GAAAAAAAGG ATCTCAAGAA GATCCTTTGA TCTTTTCTAC GG -#GGTCTGAC 4800 - - GCTCAGTGGA ACGAAAACTC ACGTTAAGGG ATTTTGGTCA TGAGATTATC AA -#AAAGGATC 4860 - - TTCACCTAGA TCCTTTTAAA TTAAAAATGA AGTTTTAAAT CAATCTAAAG TA -#TATATGAG 4920 - - TAAACTTGGT CTGACAGTTA CCAATGCTTA ATCAGTGAGG CACCTATCTC AG -#CGATCTGT 4980 - - CTATTTCGTT CATCCATAGT TGCCTGACTC CCCGTCGTGT AGATAACTAC GA -#TACGGGAG 5040 - - GGCTTACCAT CTGGCCCCAG TGCTGCAATG ATACCGCGAG ACCCACGCTC AC -#CGGCTCCA 5100 - - GATTTATCAG CAATAAACCA GCCAGCCGGA AGGGCCGAGC GCAGAAGTGG TC -#CTGCAACT 5160 - - TTATCCGCCT CCATCCAGTC TATTAATTGT TGCCGGGAAG CTAGAGTAAG TA -#GTTCGCCA 5220 - - GTTAATAGTT TGCGCAACGT TGTTGCCATT GCTACAGGCA TCGTGGTGTC AC -#GCTCGTCG 5280 - - TTTGGTATGG CTTCATTCAG CTCCGGTTCC CAACGATCAA GGCGAGTTAC AT -#GATCCCCC 5340 - - ATGTTGTGCA AAAAAGCGGT TAGCTCCTTC GGTCCTCCGA TCGTTGTCAG AA -#GTAAGTTG 5400 - - GCCGCAGTGT TATCACTCAT GGTTATGGCA GCACTGCATA ATTCTCTTAC TG -#TCATGCCA 5460 - - TCCGTAAGAT GCTTTTCTGT GACTGGTGAG TACTCAACCA AGTCATTCTG AG -#AATAGTGT 5520 - - ATGCGGCGAC CGAGTTGCTC TTGCCCGGCG TCAATACGGG ATAATACCGC GC -#CACATAGC 5580 - - AGAACTTTAA AAGTGCTCAT CATTGGAAAA CGTTCTTCGG GGCGAAAACT CT -#CAAGGATC 5640 - - TTACCGCTGT TGAGATCCAG TTCGATGTAA CCCACTCGTG CACCCAACTG AT -#CTTCAGCA 5700 - - TCTTTTACTT TCACCAGCGT TTCTGGGTGA GCAAAAACAG GAAGGCAAAA TG -#CCGCAAAA 5760 - - AAGGGAATAA GGGCGACACG GAAATGTTGA ATACTCATAC TCTTCCTTTT TC -#AATATTAT 5820 - - TGAAGCATTT ATCAGGGTTA TTGTCTCATG AGCGGATACA TATTTGAATG TA -#TTTAGAAA 5880 - - AATAAACAAA TAGGGGTTCC GCGCACATTT CCCCGAAAAG TGCCACCTGA AA -#TTGTAAAC 5940 - - GTTAATGTTT TGTTAAATTT CGCGTTAAAT ATTTGTTAAA TCAGCTTATT TT -#TTAACCAG 6000 - - TAAGCAGAAA ATGACAAAAA TCCTTATAAA TCAAAAGAAT AGACCGAGTT AG -#TTGTGAGT 6060 - - GTTGTTCCAG TTTGGAACAA GAGTCCACTA TTAAAGAACG TGGACTCCAA CG -#TAAAACCG 6120 - - TCTATCAGGG CGATGGCCCA CTACGTGAAC CATCACCCAA ATCAAGTTTT TG -#GAGGTCGA 6180 - - GGTGCCGTAA AGCACTAAAT CGGAACCCTA AAGGGAGCCC CCGATTTAGA GC -#TTGACGGG 6240 - - GAAAGCCGGC GAACGTGGCG AGAAAGGAAG GGAAGAAAGC GAAAGGAGCG GG -#CGCTAGGG 6300 - - CGCTGGCAAG TGTAGCGGTC ACGCTGCGCG TAACCACCAC ACCCGCCGCG CT -#TAATGCGC 6360 - - CGCTACTGGG CGCGT - # - #- # 6375 - - - - (2) INFORMATION FOR SEQ ID NO:15: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 483 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:15: - - AAGCTTTGGA GCTAAGCCAG CAATGGTAGA GGGAAGATTC TGCACGTCCC TT -#CCAGGCGG 60 - - CCTCCCCGTC ACCACCCCCC CCAACCCGCC CCGACCGGAG CTGAGAGTAA TT -#CATACAAA 120 - - AGGACTCGCC CCTGCCTTGG GGAATCCCAG GGACCGTCGT TAAACTCCCA CT -#AACGTAGA 180 - - ACCCAGAGAT CGCTGCGTTC CCGCCCCCTC ACCCGCCCGC TCTCGTCATC AC -#TGAGGTGG 240 - - AGAAGAGCAT GCGTGAGGCT CCGGTGCCCG TCAGTGGGCA GAGCGCACAT CG -#CCCACAGT 300 - - CCCCGAGAAG TTGGGGGGAG GGGTCGGCAA TTGAACCGGT GCCTAGAGAA GG -#TGGCGCGG 360 - - GGTAAACTGG GAAAGTGATG TCGTGTACTG GCTCCGCCTT TTTCCCGAGG GT -#GGGGGAGA 420 - - ACCGTATATA AGTGCAGTAG TCGCCGTGAA CGTTCTTTTT CGCAACGGGT TT -#GCCGCCTC 480 - - GAG - # - # - # 483 - - - - (2) INFORMATION FOR SEQ ID NO:16: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 825 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: other nucleic acid (A) DESCRIPTION: /desc - #= "DNA" - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:16: - - AATGAAAGAC CCCACCTGTA GGTTTGGCAA GCTAGCTTAA GTAACGCCAT TT -#TGCAAGGC 60 - - ATGGAAAAAT ACATAACTGA GAATAGAGAA GTTCAGATCA AGGTCAGGAA CA -#GATGGAAC 120 - - AGCTGAATAT GGGCCAAACA GGATATCTGT GGTAAGCAGT TCCTGCCCCG GC -#TCAGGGCC 180 - - AAGAACAGAT GGAACAGCTG AATATGGGCC AAACAGGATA TCTGTGGTAA GC -#AGTTCCTG 240 - - CCCCGGCTCA GGGCCAAGAA CAGATGGTCC CCAGATGCGG TCCAGCCCTC AG -#CAGTTTCT 300 - - AGCTGGAGTT CCGCGTTACA TAACTTACGG TAAATGGCCC GCCTGGCTGA CC -#GCCCAACG 360 - - ACCCCCGCCC ATTGACGTCA ATAATGACGT ATGTTCCCAT AGTAACGCCA AT -#AGGGACTT 420 - - TCCATTGACG TCAATGGGAG TTTGTTTTGG CACCAAAATC AACGGGACTT TC -#CAAAATGT 480 - - CGTAATAACC CCGCCCCGTT GACGCAAATG GGCGGTAGGC GTGTACTCTA GA -#TGCTACAT 540 - - ATAAGCAGCT GCTTTTTGCC TGTACTGGGT CTCTCTGGTT AGACCAGATC TG -#AGCCTGGG 600 - - AGCTCTCTGG CTAACTAGGG AACCCACTGC TTAAGCCTCG AATTCAGCTC AA -#TAAAAGAG 660 - - CCCACAACCC CTCACTCGGG GCGCCAGTCC TCCGATTGAC TGAGTCGCCC GG -#GTACCCGT 720 - - GTATCCAATA AACCCTCTTG CAGTTGCATC CGACTTGTGG TCTCGCTGTT CC -#TTGGGAGG 780 - - GTCTCCTCTG AGTGATTGAC TACCCGTCAG CGGGGGTCTT TCATT - #825__________________________________________________________________________
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The present invention relates to recombinant hepatitis viral vectors useful for the expression of functional heterologous gene products in liver cells. It is contemplated that these vectors will find use in anti-viral, anti-tumor and/or gene therapy, particularly for the correction of inherited single-gene defects. These novel recombinant vectors may be used to deliver genes to cells in vivo by a variety of means including infection and direct injection of vector DNA.
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BACKGROUND
[0001] Technical Field
[0002] The present invention relates to a wind turbine tower and to a method for erecting a wind turbine tower.
[0003] Description of the Related Art
[0004] For towers of wind turbines, the construction of a durably stable and even foundation is of great importance. The foundation of a wind turbine is constructed by first creating, in a foundation bed, what is termed a blinding layer, that is to say a layer of cement or concrete which is as planar and as horizontal as possible. Then, anchor rods are fixed to the foundation segments, i.e., the lower segments of the tower consisting of multiple segments, by means of which anchor rods the foundation segment is positioned on the blinding layer. In order to even out unevennesses in the blinding layer and to orient the foundation segment as horizontally as possible, the anchor rods are screwed into the underside of the foundation segment to varying extents. To that end, the anchor rods have a threaded rod.
[0005] DE 102 26 996 A1 describes a method for erecting a foundation of a wind turbine tower consisting of multiple segments. To that end, a foundation bed is excavated and a stable, essentially even and horizontal blinding layer is created. A foundation segment of the wind turbine is placed on the blinding layer, wherein at least three height-adjustable anchor rods are attached, by means of a supporting foot attached to the end of the anchor rod, to the foundation segments in a distributed manner such that only the anchor rods are established at predefined supporting points on the blinding layer. Then, a reinforcement is produced on the blinding layer and the remaining foundation is cast up to above the lower rim of the foundation segment using a foundation material such as concrete.
[0006] In the German patent application forming the basis for priority, the German Patent and Trademarks Office has searched the following documents: DE 102 26 996 A1, DE 20 2010 001 337 U1, US 2013/0129525 A1 and WO 2012/168467 A2.
BRIEF SUMMARY
[0007] The present invention is directed to a wind turbine tower and a method for erecting a wind turbine tower, which permits simple and exact orientation and/or levelling of the lower tower segment.
[0008] Thus, provided is a wind turbine tower with a plurality of tower segments which are placed one on top of another so as to form the tower. A lower tower segment has a lower end face and in the lower region of the tower segment or in the region of the lower end face a plurality of cavities and through bores between the lower end face of the lower tower segment and a bottom of the cavity. The cavities are configured for receiving a levelling unit for levelling the lower tower segment. The cavities are preferably provided on the inside of the lower tower segment and represent an effective possibility for receiving levelling units.
[0009] According to one aspect, a plurality of levelling units is placed in the cavities. Each of the levelling units has a supporting foot and/or a rod which can be inserted through the through bore into the cavity. The levelling unit is configured to set the length of the rod or the separation between the lower end of the supporting foot and the bottom of the cavity for levelling the lower tower segment.
[0010] According to a further aspect, the levelling unit has a hydraulic unit for setting the length of the rod for levelling the lower tower segment.
[0011] It is thus possible for the lower tower segment to be levelled in particular automatically and very precisely by means of the hydraulic unit.
[0012] According to a further aspect, the levelling unit has a supporting frame with two sidewalls, a bottom and a cover as well as an intermediate bottom. The bottom and the intermediate bottom each have a cutout, such that the supporting frame can be inserted into the cavity if the rod and/or the supporting foot has been inserted through the through hole into the cavity.
[0013] According to a further aspect, a nut is screwed onto the rod. For arresting the levelling of the lower tower segment, the nut is screwed onto the rod such that it bears beneath the intermediate bottom.
[0014] According to a further aspect, the supporting foot and the (threaded) rod can be configured as one part or in two parts.
[0015] The invention also relates to a method for erecting a wind turbine tower which has a lower tower segment that has a plurality of cavities in the lower region. The lower tower segment further has a plurality of through bores between a lower end face of the lower tower segment and a bottom of the cavity. One end of the supporting foot and/or of a rod is inserted through the through bore. A levelling unit is placed into the cavity and the lower tower segment is oriented and/or levelled using the levelling units by setting the separation between the lower end of the supporting foot and the bottom of the cavity or the cavity itself.
[0016] The invention relates to the concept, of providing, in the lower region of the lowest tower segment of the tower of the wind turbine and on the inside of the tower, a plurality of cavities which are open inwards and which each have a through bore towards the underside of the lowest tower segment. A levelling unit is inserted into this cavity, wherein a (threaded) rod with a foot is pushed through the through bore from below, such that the tower segment rests on the feet.
[0017] The height or the length of the (levelling) foot can optionally be set hydraulically. If, at this point, a plurality of cavities and levelling units is provided along the circumference of the lower tower segment, it is then possible, by controlling the hydraulics, to set the height of the levelling feet of the respective levelling units such that the lowest tower segment is levelled to horizontal. In order to check the horizontal levelling, optical measuring units such as lasers or the like can be used.
[0018] The levelling unit has a (levelling) foot with a (threaded) rod which is provided through the through bore between the lower end face of the lowest tower segment and the bottom of the cavity. A nut is provided at the upper end of the threaded rod. Then, a levelling frame (e.g., in the form of a supporting frame) can be inserted into the cavity. The levelling frame has a bottom and an intermediate bottom, each with a cutout, such that the levelling frame can be introduced into the cavity after the threaded rod has been introduced through the through bore. The intermediate bottom of the levelling frame is then located above the nut. The frame can then be screwed upwards by actuating the nut, such that it bears against the underside of the intermediate bottom. In this case, the load exerted by the lower tower segment on the foundation, can be transmitted to the levelling foot via the intermediate bottom, the nut and the threaded rod.
[0019] A plurality of cavities and/or recesses is provided on the inside and in the lower region of the lower tower segment. A through bore is provided between the cavity and the lower end face of the lower tower segment. The cavity and the through bore can subsequently be bored or milled into the lower tower segment. Alternatively, during production of the tower segment, which is typically a concrete tower segment, both the cavities and the through holes can be left free.
[0020] Further configurations of the invention form the subject matter of the subclaims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0021] Advantages and exemplary embodiments of the invention are explained in more detail below with reference to the drawing.
[0022] FIG. 1 shows a schematic representation of a wind turbine according to the invention,
[0023] FIG. 2A shows a schematic representation of a lower tower segment of a wind turbine tower according to a first exemplary embodiment,
[0024] FIG. 2B shows a schematic section view of a lower tower segment according to the first exemplary embodiment,
[0025] FIG. 3 shows a schematic representation of a levelling unit for levelling a lower tower segment of a wind turbine tower according to a second exemplary embodiment,
[0026] FIG. 4 shows a schematic plan view of the levelling unit of FIG. 3 ,
[0027] FIG. 5 shows a schematic side view of the levelling unit of FIG. 3 ,
[0028] FIG. 6 shows a schematic representation of a threaded rod of the levelling unit according to the second exemplary embodiment,
[0029] FIG. 7 shows a view of a nut of a levelling unit according to the second exemplary embodiment, and
[0030] FIGS. 8A-8B respectively show a schematic section view A-B and A-A and B-B of the nut of FIG. 7 .
DETAILED DESCRIPTION
[0031] FIG. 1 shows a schematic representation of a wind turbine according to the invention. The wind energy 100 has a tower 102 and a nacelle 104 on the tower 102 . The tower 102 has a plurality of tower segments 102 a which are placed one after another on a foundation 10 in order to form the tower 102 . On the nacelle 104 there is provided an aerodynamic rotor 106 with three rotor blades 200 and a spinner 110 . When the wind turbine is in operation, the aerodynamic rotor 106 is set in rotation by the wind and thus also turns a rotor of a generator, which is coupled either directly or indirectly to the aerodynamic rotor 106 . The electric generator is arranged in the nacelle 104 and generates electrical energy. The pitch angles of the rotor blades 200 can be changed by pitch motors at the rotor blade roots of the respective rotor blades 200 .
[0032] FIG. 2A shows a schematic representation of a detail of a lower tower segment of a wind turbine tower according to a first exemplary embodiment. A plurality of cavities 102 b is provided in the lower tower segment 102 a. The lower tower segment 102 a has a (lower) end face 102 d. In the lower tower segment 102 a there is provided a plurality of through holes or through bores 102 c which extend between the lower end face 102 d and a bottom 102 e ( FIG. 2B ) of the cavity 102 b. A levelling unit 300 is provided in the cavity 102 b. The levelling unit 300 has a supporting frame 310 , an intermediate bottom 311 , a hydraulic unit 320 , a threaded rod 330 and a supporting foot 350 . A levelling foot 360 is provided at the lower end of the supporting foot 350 . The supporting foot 350 and the levelling foot 360 can be configured as one component. The threaded rod 330 and the supporting foot 350 can be configured as one component (with the threaded rod above and the supporting foot below) or as separate components. A nut 340 is screwed on over the upper end of the threaded rod 330 . The supporting foot 350 with the levelling foot 360 is inserted into the through bore 102 c. Then, the threaded rod 330 can be secured to (e.g., screwed onto) the supporting foot and the nut 340 can be screwed onto the threaded rod 330 . After this, a supporting frame 310 of the levelling unit 300 is introduced into the cavity 102 b. To that end, in reference also to FIG. 3 , the bottom 310 c and the intermediate bottom 311 each have a cutout 310 f, 311 a, ( FIG. 5 ) such that the frame 310 is pushed into the cavity 102 b and the supporting foot 350 is accommodated in the two cutouts 310 f, 311 a. The levelling unit 300 also has a hydraulic unit 320 with a hydraulic connection 321 . A hydraulic hose 321 can be connected to the hydraulic connection 321 , such that the hydraulic unit 320 can be activated. When the hydraulic unit 320 is activated, it can then press on the upper end of the threaded rod 330 and can thus raise or lower the lower tower segment 102 a.
[0033] FIG. 2B shows a schematic section view of a lower tower segment according to the first exemplary embodiment. The lower tower segment 102 a has a lower end face 102 d and a plurality of cavities 102 b. Preferably, the cavities 102 b are configured such that they are open towards the inside of the tower segment. The cavities 102 b have a bottom 102 e. Between the bottom 102 e of the cavity 102 b and the end face 102 d of the lower tower segment there is provided a through bore 102 c. A supporting foot 350 can be inserted (from below) into this through bore 102 c. The supporting foot 350 can have a levelling foot 360 . Optionally, the supporting foot 350 and the levelling foot 360 can be configured as one component. After the supporting feet 350 have been introduced into the through bores 102 c, a lower tower segment can be placed on a foundation 10 of the wind turbine. Optionally, a cutout 11 can be provided on the upper side of the foundation 10 . The supporting feet 350 and thus the lower tower segment or the lower end face 102 d of the lower tower segment can be placed in the region of the cutout 11 . After the lower tower segment 102 a has been oriented by means of the levelling unit 300 , the cutout 11 can be filled with Pagel mass or with a curable casting compound. This is advantageous because thus the weight of the lower tower segment and of the further tower segments and finally of the nacelle and of the rotor then rests not only on the supporting feet 350 , but is distributed by the Pagel mass 20 .
[0034] FIG. 3 shows a schematic representation of the levelling unit according to a second exemplary embodiment. The levelling unit 300 has a (supporting) frame 310 with two sidewalls 310 a, 310 d, a cover 310 b, a bottom 310 c and an intermediate bottom 311 . The bottom 310 c and the intermediate bottom 311 can each have a longitudinal cutout 310 f, 311 a. The levelling unit 300 further has a threaded rod 330 , a supporting foot 350 and a levelling foot 360 at one end of the supporting foot 350 . The nut 340 is screwed on over the other end of the threaded rod 330 . In the installed state, the second end of the threaded rod 330 projects beyond the intermediate bottom 310 . The supporting foot and the threaded rod 330 can be configured as separate components or as one component.
[0035] FIG. 4 shows a schematic representation of a schematic cross section of a levelling unit according to FIG. 3 . The levelling unit has a supporting frame with two sidewalls 310 d, 310 a. Further, the levelling unit has an intermediate bottom 311 and a bottom 310 c. A cutout 312 is provided in the bottom 310 c. The same is true in corresponding fashion for the intermediate bottom 311 . The cutout 312 serves for receiving the threaded rod 350 , 330 .
[0036] The levelling unit further has a threaded rod 330 and a nut 340 .
[0037] FIG. 5 shows a perspective side view of a levelling unit according to the second exemplary embodiment. The levelling unit 300 has a supporting foot 350 with a (levelling) foot 360 . The levelling unit 300 further has a supporting frame 310 with a bottom 310 c, a cover 310 b, two sidewalls 310 a, 310 d and an intermediate bottom 311 . The intermediate bottom 311 and the bottom 310 c each have a cutout such that the threaded rod can be received in the cutout.
[0038] FIG. 6 shows a schematic representation of a threaded rod 330 .
[0039] FIG. 7 shows a schematic representation of the nut 340 . The nut 340 has a plurality of holes 341 and optionally an internal thread.
[0040] FIGS. 8A and 8B respectively show a section view, along A-A and B-B, of the nut of FIG. 7 . The nut 340 has a plurality of holes 341 on its outer side.
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A wind turbine tower is provided with a plurality of tower segment which are placed one on top of the other in order to form the tower. A lower tower segment has a lower end face, and in the lower region of the lower tower segment, the lower tower segment has a plurality of recesses and through-bores between the lower end face of the lower tower segment and a base of the recesses. The recesses are designed to receive a leveling unit for leveling the lower tower segment. The recesses are preferably provided on the inner face of the lower tower segment and provide an effective possibility for receiving leveling units.
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REFERENCE TO RELATED APPLICATION
[0001] This application claims priority benefit of Provisional Patent Application Serial No. 60/______, filed Apr. 19, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to games, and more particularly to a game which combines traditional board game elements and an unrelated activity such as preparing a meal. Steps of the unrelated activity are melded into steps of playing the game.
[0004] 2. Description of the Prior Art
[0005] Parlor games such as board games have become a favored way of passing time sociably with friends and acquaintances. Parlor games enable participants to pass time pleasurably while escaping from pressures and demands of day to day living. Sociable gatherings also frequently center about meals. Meals provide an enjoyable activity in which conversation usually plays a significant role. When the purpose of a meal is to foster social interaction as well as for mere nourishment, beverages, particularly alcoholic beverages are usually available.
[0006] The role of host in gatherings can be quite time consuming, especially where significant time must be devoted to preparation and serving of food and beverages. This can interfere with the host's attention to and interaction with guests. One approach to freeing a host to interact with the guests is to engage the services of others such as servants or persons engaged for one gathering. However, it is not always economically feasible and may not be desirable to introduce additional people into a household during a social event. It is desirable to accomplish the diverse tasks related to food and beverage preparation while enabling hosts to interact with guests.
[0007] It will further be appreciated that both parlor games and meals are significant elements of certain social gatherings. It would be desirable to combine these two disparate elements of a social gathering into one.
SUMMARY OF THE INVENTION
[0008] The present invention addresses the need of combining entertaining activities, such as parlor games, with food and beverages typically provided at social gatherings. It also addresses the problem of accommodating the conflicting demands on the time and attention of hosts.
[0009] To these ends, there is set forth a board game which incorporates at least some of the tasks associated with a feast or other social gathering. Specifically, individual tasks in preparing food and beverages are apportioned among the players of the game as steps of the game. Tasks can thereby be relatively evenly divided among those present at the gathering, and may be performed in a social setting.
[0010] The novel game includes a board game, player tokens or pieces which are moved along spaces arranged in paths on the board, dice for determining progress of each player piece at each turn or move, and cards bearing instructions. Several categories of cards are provided. Activity cards which are color coordinated with spaces on the board require an action by each player landing on a space associated with the cards. For example, an activity card may bear a question requiring a response. A correct answer to a question appearing on an activity card entitles the player to proceed. Arrival at the end of each path determines, by order of finishing, which players perform which tasks associated with preparation of food and beverages. Instruction cards are provided to guide each player in accomplishing his or her tasks. Preferably, there are three paths which are to be negotiated by all players, with each path corresponding to one course of the feast. This affords the players to assume different roles in preparation of food and beverage as play progresses. It will be seen that participation in the game by both guests and hosts accomplishes the dual purposes of preparing and serving a meal while promoting social interaction among the participants.
[0011] This and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0013] [0013]FIG. 1 is a plan view of the board apparatus.
[0014] [0014]FIG. 2 is a plan view of the obverse of a first variety of an activity card which is part of the game apparatus.
[0015] [0015]FIG. 3 is a plan view of the reverse of the activity card of FIG. 2.
[0016] [0016]FIG. 4 is a plan view of the obverse of a second variety of an activity card which is part of the game apparatus.
[0017] [0017]FIG. 5 is a plan view of the reverse of the activity card of FIG. 4.
[0018] [0018]FIG. 6 is an enlarged detail view of a space seen at the right center of the board, as depicted in FIG. 1, seen in plan view.
[0019] [0019]FIG. 7 is an enlarged detail view of a space seen at the upper center of the board, as depicted in FIG. 1, seen in plan view .
[0020] [0020]FIG. 8 is a plan view of the obverse of a first variety of an instructional card which is part of the game apparatus.
[0021] [0021]FIG. 9 is a plan view of the reverse of the instructional card of FIG. 8.
[0022] [0022]FIG. 10 is a plan view of the obverse of a postcard which is optionally utilized as an invitation for the novel game.
[0023] [0023]FIG. 11 is a plan view of the reverse of the postcard of FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Turning now to FIG. 1 of the drawings, the game apparatus includes a board 10 which bears a plurality of position spaces arranged serially in three progressions or paths 12 , 14 , 16 . Tokens or player pieces (not shown) are to be moved along paths 12 , 14 , 16 by alighting upon and occupying a position space. The exact number of spaces of movement is determined by a number generating device, for example, a chance device such as a die or dice (not shown). A player piece may be, for example, a miniature figurine or any small object which is readily placed on and occupies any position space of paths 12 , 14 , 16 . Player pieces are well known in board games wherein a representative token for each player is to be moved along and occupy serially arranged spaces on a board, and hence will not be described in greater detail herein. Dice and other chance devices such as spinners are equally well known and hence will not be described.
[0025] Path 12 is seen to have an initial or starting space 17 , which for convenience in accommodating a plurality of player pieces may be divided into a plurality of sections 17 a, 17 b, 17 c, 17 d (see FIG. 6). Division of space 17 into sections enables an intuitive grasp of how to prepare to play, and has no significance regarding progress along path 12 or regarding competitive advantage. The same holds true for that section shown in FIG. 1 bearing the legend “Round 1”. Space 17 abuts a space 18 , which in turn abuts a space 20 .
[0026] It will be seen that path 14 has a starting space 24 and a final or finish space 26 , and that path 16 has a starting space 28 and a finish space 30 . The game is played in three phases, each phase corresponding to one path 12 , 14 , or 16 . The goal of the game is to be the first player to advance from the starting space (e.g., space 17 of path 12 ) to the finish space (e.g., space 22 of path 12 ) in each of the three phases.
[0027] The embodiment depicted and described herein utilizes three paths 12 , 14 , 16 , and accommodates four player pieces. Each player piece represents either a single person or a group or team, such as a couple. Each player, or one representative from each team, operates the chance device, which in the preferred embodiment is dice, to determine order of play. When order of play is determined, the first player throws the dice and advances along path 12 starting from starting space 17 according to the count determined by the dice. The number of spaces (e.g., spaces 18 and 20 and succeeding spaces) corresponds to the throw of the dice.
[0028] It will be seen that space 18 bears brown coloring 32 and that space 20 bears green coloring 34 . Similarly, all succeeding spaces bear coloring (not indicated). Preferably, there are at least four colors provided. The spaces of paths 14 and 16 are similarly treated with coloring. Upon having his or her playing piece alight on any space as a result of a move or turn, the player who has made the move draws an activity card. The obverse of an exemplary activity card 36 is shown in FIG. 2. It will be seen that activity card 36 bears coloring 38 which is coordinated with, preferably being identical to, one of the colors borne by spaces of path 12 . In the present example, coloring 38 is similar or identical to coloring 32 of space 18 . The player whose playing piece has alighted on space 18 must draw a card from a plurality of cards bearing similar coloring.
[0029] There are a plurality of varieties of activity cards, each variety being associated with a different type of activity and containing instructions to perform an activity such as providing a verbal response to an inquiry. Illustratively, activity card 36 is associated with toasting. To perform the activity associated with card 36 , the player who has drawn card 36 turns to the reverse side 40 of card 36 . As seen in FIG. 3, reverse side 40 bears indicia corresponding to an instruction to complete a toast, basic elements of which are suggested on card 36 . Completion of the activity specified on card 36 entitles the player to roll 1 die and move his or her playing piece along path 12 , accordingly. Alternatively, an activity card may require the player drawing the same to move his or her player piece by a specified number of spaces forwardly or backwardly. Some activity cards may not affect position of the player piece on the board.
[0030] [0030]FIG. 4 shows a second variety of activity card. Card 42 has an obverse side 44 bearing indicia corresponding to instructions. Reverse side 46 of card 42 (see FIG. 5) poses a question which is to be answered by the player who has drawn card 42 . Card 42 bears coloring 48 corresponding to coloring 34 of space 20 of board 10 . A player whose playing piece alights upon space 20 , or any other space bearing similar coloring, must draw one card from a plurality of that variety of activity cards which bears similar coloring. The player must follow directions appearing upon the drawn card.
[0031] This principle is followed for all spaces of path 12 , wherein all spaces bear one of the colors associated with each variety of activity cards. Two further exemplary varieties of activity cards include one variety dedicated to music and one variety dedicated to questions relating to trivia. That variety dedicated to music requires the player drawing the card to select a melody from several presented on the card, and to hum, whistle, tap the beat of that melody, or otherwise reproduce aspects of the specified melody without uttering any words associated with the melody, so that other players can identify the melody. The player drawing the card and the first player to successfully identify the melody are permitted to advance along the board according to instructions borne on the card.
[0032] The variety of cards dedicated to trivia preferably relate to the theme of the present game, namely, food or beverages. The player drawing the card reads a question appearing upon the card and if successfully answering within a predetermined time interval, such as thirty seconds, is permitted to advance along the board.
[0033] Neither one of the further exemplary varieties is shown. These further varieties are provided as part of the game apparatus to increase the number of varieties of activities, so that ability of participants to satisfy demands of the activity cards does not favor any player or players who are particularly able in just one field of knowledge. The additional fields of knowledge and endeavor have a tendency to even out individual performances when responding to an activity card. It will be appreciated that the number of varieties of activity cards correlates to the number of different colors borne by the spaces of board 10 .
[0034] Optionally, reverse side 40 of card 36 may bear coloring 38 which is identical to that seen on the obverse side. This promotes ready organization of the cards prior to playing the game or thereafter.
[0035] Play proceeds with each player or team taking a turn to move according to the order established at the beginning of the game. The first player to arrive at finish space 22 of path 12 may select among the options shown in FIG. 7. Arrival at finish space 22 signifies either alighting directly on finish space 22 or alternatively, passing finish space 22 as a result of the numerical value indicated by the number generator. In FIG. 7, it is seen that finish space 22 is subdivided into four sections, one section 22 a being designated “Winner”, a second section 22 b being designated “Wait Staff”, a third section 22 c being designated “Beverage Manager”, and the final section being designated “Appetizer Chef”. Players arriving at finish space 22 after the first player to do so may select among the remaining options as they arrive at finish space 22 , and are thus deprived of options selected prior to their arrival. The last player to arrive at finish space 22 must move immediately, by default, without utilizing the chance device, to the space corresponding to the final available option. Of course, spaces other than finish space 22 could be designated as being associated with performing a step in preparing food or beverage or both, rather than or in addition to finish space 22 being so designated.
[0036] The legends designated on the various sections of finish space 22 relate to the role to be played by that player whose playing piece occupies the corresponding section 22 a, 22 b , 22 c, or 22 d. The player designated “Winner” is relieved of the necessity to perform any chore related to preparing food or beverage or both. The others must assume responsibilities associated with their respective designated roles. As exemplified in FIGS. 8 and 9, each of the participants having responsibilities relating to preparation of food or beverage is given an instructional card. The instructional card directs the player drawing the same to perform a step in the preparation of food or beverage or both to be consumed during the gathering associated with the game, and further provides specific instructions regarding a particular item of food or beverage. As employed herein, preparation encompasses cleaning and other ordinary activities that would be performed by professional wait staff, including, for example, removing dishes, drinking glasses, and any waste associated with food and beverages generated during the game.
[0037] An exemplary card 50 bears instructions for the responsibility to be assumed by that player drawing card 50 . General instructions relating to the role appear on the obverse side of instructional card 50 . Specific instructions, in this example, relating to one of the predetermined comestibles to be prepared as part of the feast, are shown on the reverse side 52 of card 50 . Different instructions are provided for the roles of “Wait Staff” and “Beverage Manager”.
[0038] Once all of the participants have negotiated first path 12 and have completed the duties associated with their respective roles, the food and beverages that have been prepared are consumed. Play at board 10 then resumes, with the participants utilizing the spaces of path 14 . The rules of play for the second phase, that utilizing path 14 , are similar to those which apply to the first phase. At the conclusion of board play of the second phase, the entree is prepared by a protocol similar to that which applied to the appetizers prepared at the conclusion of the first phase of play. Roles and instructions appropriate to an entree of a meal must obviously differ from those for appetizers, but the same general principles prevail.
[0039] The overall principles are again repeated for the third phase of play, that employing the spaces of path 16 and culminating in preparation of dessert. Again, roles and instructions for dessert differ from those appropriate for appetizers and entrees.
[0040] Preferably, a pamphlet of instructions (not shown) is provided for explaining the game. Because preparation of a full meal may prove a considerable undertaking, the instructions preferably list all ingredients which may be required in order to follow preparation instructions, estimate time required to complete preparation of portions of the meal, and may provide directions advising the host as to what must be done to maintain expeditious progress throughout the game, as well as stating the rules of play.
[0041] It will be apparent that different meals may be prepared utilizing the same board, which is generic with regard to types of food. To this end, alternative sets of activity cards and instructional cards may be provided or made available. The alternative sets of cards differ in the recipes, types of food, and to some extent, roles, but will follow the same method of play as that set forth above.
[0042] Optionally, the game apparatus includes a plurality of postcards, a representative postcard 54 being illustrated in FIG. 10. Postcards are provided as invitations which may be mailed to prospective guests. Apart from the conventional return address lines, destination address lines, and indication of a preferred location for affixing for postage, all shown on the obverse side 56 of postcard 54 , there is indicia 58 corresponding to the actual invitation, including for example announcement of a social gathering and playing of an associated board game, and blank lines 60 for entering specific supplies which may be requested of the various guests. Requesting guests each to bring some of the required supplies reduces burden on the host, although the latter may be willing to provide all necessities if desired. Although it is most practical that invitations be configured as postcards, as depicted in FIG. 10, they may take any form configured as mail.
[0043] Certain aspects of the preferred embodiments may be modified without departing from the inventive concept. For example, color coordinating cards and spaces can be modified to employ any visual similarity other than color. For example, spaces and cards may bear similar pictorial devices, border decoration, or other visually distinguishable characteristics readily enabling activity cards to be visually associated with their respective position spaces.
[0044] The number of players and phases, where the latter refers to courses and paths of serially arranged playing spaces, may be varied to suit.
[0045] The game apparatus need not literally comprise a board. Conventional game boards are formed from paper or cardboard stock, and are imprinted with an image containing position spaces, instructions, and other indicia necessary or desirable to the play of the game. While a conventional game board is seen as the preferred embodiment, the novel game may be played utilizing any surface provided with an image of at least one path comprising sequentially disposed position spaces. The image could be painted or otherwise inscribed upon the surface of furniture, countertops, a flaccid material such as a blanket or section of plastic sheet, or any other object. Alternatively, the image could be projected onto a screen, a wall, or other surface, or could be provided as a dynamic display, such as a cathode ray tube, a flat screen display, other apparatus enabling visible reproduction of images, or a combination of these. To play the game, it is merely necessary to make an image of the path of position spaces visible to the participants. Similarly, the player pieces may take any form appropriate to the medium displaying the image of the path or paths.
[0046] Arrangements other than a chance device may be employed for determining the number of spaces to be negotiated during a move. For example, cards (not shown) bearing numerical values may be drawn in lieu of dice being thrown or a spinner being operated. Mental calculations and operations may be substituted for mechanical apparatus determining a number. For example, the digits of the year of one's birth, one's Social Security number, address, or of other significance to a player may be summed until one digit remains, that digit determining magnitude of a move of a player piece. This may be done by moving the piece by the exact numerical value shown, or by using the numerical value in some other way, as long as the number generator ultimately determines magnitude of each move of a player piece along the board.
[0047] An automatic device such as a digital random number generator may be employed, particularly where the game is rendered in digital fashion, with the image being provided on a cathode ray tube or other display. The method of generating numbers for moving player pieces is not critical to the game.
[0048] It will be appreciated that activity cards and instructional cards bearing instructions may be replaced or supplemented by any suitable medium for conveying the subject matter. Therefore, any indicia bearing member, including dynamic displays or even audible devices, will be regarded as equivalent to paperboard cards.
[0049] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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A board game which combines traditional board game elements with an unrelated activity, that of preparing a meal. The board has three paths of serially arranged spaces along which player tokens travel. A chance device determines the number of spaces moved. Upon alighting on any particular space, a card is drawn, which card is color coordinated to the space just occupied. The card specifies an interactivity such as a question to be answered or a musical theme to be tapped, hummed or whistled. The player must interactively respond. Upon completion of the first path, players select, on a first-to-arrive basis, a task associated with meal preparation, serving, and cleanup. An example is mixing and serving of a beverage, or cooking the entree. One option is to be relieved of any task. Upon completion of the path by his or her token, each player receives an instructional card advising details of the associated task. The game is played in three phases, each utilizing one path and corresponding to three phases of a meal, such as appetizer, entree, and dessert. Optionally, invitations to a combined meal and game are sent prior to the event by postcard. The invitation optionally specifies
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The present application claims priority from provisional application serial No. 60/318,052 filed Sep. 7, 2001. The content of that application is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Performance additives in high performance polymers using polyhedral oligomeric silsesquioxanes (POSS) and polyhedral oligomeric silicates (POS) as nanoscopic reinforcements, porosity control agents, thermal and oxidative stability aids to improve the properties of the polymers.
2. Description of the Prior Art
There is a continuing need for polymeric materials that exhibit higher performance characteristics. In particular, many electronic and space vehicle component designs now demand materials with improved thermal and oxidative stability relative to that offered by the current level of imide, epoxy, and ester-based polymer resins. There exists a particular deficiency in the area of space resistant polymeric materials as there are no commercially available polyimides that are resistant to degradation by atomic oxygen. Prior art in this field describes attempts to improve survivability of imides to the space environment through the application of metals or metal-oxide coatings, which results in modest improvements but is not practical because of the additional processing steps and property mismatches (e.g. thermal expansion). Other approaches have involved the incorporation of fillers into polyimides through sol-gel methods or the blending of inorganic fillers. While conceptually simple the utility of this approach has also been limited. For example Yanno et al. have reported the use of complex processing steps (Hsiue, G -H, Chen, J -K., Liu, Y -L J. Appl. Polym. Sci ., 2000, 76, 1609-1618) and Gilman et al. have described the inherent incompatibility of such organofunctionalize fillers to uniformally disperse (Brown, J. M., Curliss, D., Vaia, R. A., Chem. Mater ., 2000, 12, 2279-3384) into the material at the molecular or nanoscopic level. Additional prior art has focused on the polymerization of silicones (Katz, U.S. Pat. No. 5,073,607) and phosphine oxides ((a) Smith, C. D., Grubbs, H., Webster, H. F. Gungor, A., Wightman, J. P., McGrath, J. E., 1991 , High Perform. Polym , 3, 211. (b) Fewell, L. L., J. Appl. Polym. Sci ., 1990, 41, 391) into polyimides in attempts to ensure uniform dispersion of an oxide forming component that can serve to protect the polyimide through formation of a passivating layer. This approach has been successful in retarding the rate at which damage in polyimides occurs during atomic oxygen exposure but the method has proven of little utility in protecting from degradation by other types of radiation nor is the approach general enough to offer protection to other types of polymeric materials, such as epoxies, esters, elastomers and sealants, that are also desirable for use on space vehicles.
A related need for higher performance polymeric materials also exists in many electronic component designs. The requirements for improved thermal (in excess of 400° C.) and oxidative stability (to atomic oxygen, ozone, etc.) and reduced dielectric properties are similar to those needed for survivability in space environments. Prior art has been deficient in offering a generally applicable and easily implemented solution for upgrading the properties of imides, epoxy, ester and related polymeric materials desirable for use in the manufacture and packaging of electronic devices and systems. There exists a particular deficiency in the area of thermally stable, tough, and low dielectric constant (k<2.5) polymeric materials. Prior art in this field has involved the incorporation of fillers into polyimides through sol-gel methods or the blending of inorganic fillers. While conceptually simple the utility of this approach has also been limited due to inherent incompatibility, dispersion, and complex processing issues. Other approaches describe attempts to create desirable improvements in such polymers through the blending of amic-acid or imidized polymers with porogenic-type materials that introduce open-cell porosity upon their removal of the porgen by heating or extraction. (U.S. Pats. No. 6,204,202; 6,177,360; 6,107,357; 5,953,627). The effectiveness of this approach has been limited in that the introduction of open-cell porosity results in materials with poor ductility and durability whereas pores with a closed-cell structure would result in materials with more desirable properties.
All of the prior art pertaining to high performance polymeric materials fails to utilize nanoscopic entities as building blocks for the improvement of the characteristics of material and physical properties such as operational temperature range, durability, oxidative stability, flammability, and mechanical strength. Furthermore the prior art fails to recognize the important contribution that nanoscale reinforcements and varied nanoscopic topologies (shapes) can have on the physical properties.
Polyhedral oligomeric silsesquioxane (POSS) cage molecules, monomers, polymers, and resins as well as polyhedral oligomeric silicate (POS) (spherosilicate) cage molecules, monomers, polymers, and resins are increasingly being utilized as building blocks for the preparation of novel catalytic materials and as performance enhancement additives for commodity and engineering polymers. Their nanometer size and unique hybrid (inorganic-organic) chemical composition are responsible for the many desirable property enhancements that have been observed upon incorporation of POSS/POS reagents into polymer systems. Of special importance for high performance polymers is that the thermochemical properties of POSS molecules are very high (400-500° C.). (Mantz, R. A., Jones, P. F., Chaffee, K. P., Lichtenhan, J. D., Gilman, J. W., Ismail, I. M. K., Burmeister, M. J. Chem. Mater ., 1996, 8, 1250-1259) Additionally, POSS-siloxane copolymers have previously been shown to exhibit excellent resistance to oxidation by atomic oxygen. (Gilman, J. W., Schlitzer, D. S., Lichtenhan, J. D., J. Applied Poly. Sci . 1996, 60, 591-596). The ability of the nanoscopic POSS entity to be polymerized into all elastomers, thermoplastics, and thermoset polymers along with its inherent ability to absorb radiation and ability to form passivating silica layers upon oxidation renders it a general solution from which to develop the next generation of high performance resins for electronic and space system applications. The resulting silica layer and POSS nanoreinforcement also serve to protect the virgin material from damage by ultraviolet radiation as they both absorb UV of 256 nm and higher (FIG. 1 ).
SUMMARY OF THE INVENTION
This invention teaches the use of nanoscale POSS and POS chemicals as performance additives that can be polymerized or noncovalently blended into high performance polymers (imides, epoxies, ester) for the introduction of nanoscopic reinforcements, porosity control agents, thermal and oxidative stability aids that improve the interfacial, surface, physical and mechanical properties of high performance polymeric resin systems. The precisely defined nanoscopic features provided by the POSS/POS agents provide multi-length scale levels of reinforcement in such polymers and hence can be used synergistically with conventional fillers and fiberous reinforcements and fillers. POSS/POS can be incorporated into high performance polymers using nonreactive compounding or blending, reactive processing and reactive grafting, or through copolymerization.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates formation of a passivating surface layer upon oxidation of a POSS-resin;
FIG. 2 shows examples of common silsequioxane, silicate, POSS nanostructures and fragments;
FIG. 3 shows the anatomy of a POSS nanoscale chemical;
FIG. 4 shows open-cage mono, di, and poly functional amines;
FIG. 5 shows closed-cage mono, di, and poly functional amines;
FIG. 6 shows a route for efficient synthesis of POSS-analines;
FIG. 7 shows a synthetic route yielding a POSS-polyimide polymer;
FIGS. 8 and 9 show cast films and thermal mechanical properties for a POSS-polyimide polymer;
FIG. 10 shows the formula and structure for a fluorinate POSS-polyimide; and
FIGS. 11 and 12 shows the formula and structure for POSS-polyetherimides.
Definition of Formula Representations for Nanostructures
Nanoscale chemicals are defined by the following features. They are single molecules and not compositionally fluxional assemblies of molecules. They possess polyhedral geometries with well-defined three-dimensional shapes. Clusters are good examples whereas planar hydrocarbons, dendrimers and particulates are not. They have a nanoscopic size that ranges from approximately 0.7nm to 5.0 nm. Hence, they are larger than small molecules but smaller than macromolecules. They have systematic chemistries that enable control over stereochemistry, reactivity and their physical properties.
For the purposes of understanding this invention's nanoscale chemical compositions, the following definition for formula representations of Polyhedral Oligomeric Silsesquioxane (POSS) and Polyhedral Oligomeric Silicate (POS) nanostructures is made.
[(RSiO 1.5 ) n (R′SiO 1.5 ) m ] Σ# for heteroleptic compositions (where R≠R′)
[(RSiO 1.5 ) n (RXSiO 1.0 ) m ] Σ# for functionalized heteroleptic compositions (where R groups can be equivalent or inequivalent)
[(RSiO 1.5 )]∞ for polymeric compositions
[(XSiO 1.5 )] Σ# for homoleptic silicate compositions
In all of the above R=organic substituent (H, siloxy, cyclic or linear aliphatic or aromatic groups that may additionally contain reactive functionalities such as alcohols, esters, amines, ketones, olefins, ethers or halides). X includes but is not limited to OH, Cl, Br, I, alkoxide (OR), acetate (OOCR), peroxide (OOR), amine (NR 2 ) isocyanate (NCO), and R. The symbols m and n refer to the stoichiometry of the composition. The symbol Σ indicates that the composition forms a nanostructure and the symbol # refers to the number of silicon atoms contained within the nanostructure. The value for # is usually the sum of m+n. It should be noted that Σ# is not to be confused as a multiplier for determining stoichiometry, as it merely describes the overall nanostructural characteristics of the system (aka cage size).
POSS Fragments are defined as structural subcomponents that can be assembled into POSS nanostructures and are represented by formula [(RSiO 1.5 ) n (RXSiO 1.0 ) m ]. Note the symbols Σ# are absent as these fragments are not polyhedral nanostructures.
Examples of common silsesquioxane, silicate, POSS nanostructures and fragments are shown in FIG 2 .
DETAILED DESCRIPTION OF THE INVENTION
A structural representation for nanoscale chemicals based on the class of chemicals known as polyhedral oligomeric silsesquioxanes (POSS) is shown in FIG. 3 .
Their features include a unique hybrid (organic-inorganic) composition that possesses many of the desirable physical characteristics of both ceramics (thermal and oxidative stability) and polymers (processibility and toughness). In addition they possess an inorganic skeleton which is externally covered by compatiblizing organic groups R and reactive groups X where R=organic substituent (H, siloxy, cyclic or linear aliphatic or aromatic groups that may additionally contain reactive functionalities such as alcohols, esters, amines, ketones, olefins, ethers or halides). X includes but is not limited to OH, Cl, Br, I, alkoxide (OR), acetate (OOCR), peroxide (OOR), amine (NR 2 ) isocyanate (NCO), olefin, and R.
Methods describing the systematic variation of cage size and distribution (U.S. patent application Ser. No. 09/631,892) (the disclosure of which is hereby incorporated by reference), along with the systematic variation of R and R—Y groups on the POSS/POS systems have been accomplished using the following methods: silation, U.S. Pat. No. 5,484,867; hydrosilation, U.S. Pat. No. 5,939,576; metathesis, U.S. Pat. No. 5,942,638, group substitution, U.S. Pat. No. 6,100,417; and through direct synthesis (U.S. Pat. No. 5,047,492 and U.S. patent application Ser. No. 10/186,318 (the disclosure of which is hereby incorporated by reference)). The design and synthesis of POSS/POS compounds with cage sizes and shapes along with R and RY groups desirable for all conceivable has been accomplished using the above mentioned methods.
The unique hybrid (organic-inorganic) composition possesses many of the desirable physical characteristics of ceramics (thermal and oxidative stability) and polymers (processibility and toughness). In addition, the inorganic skeleton, comprised of silicon-oxygen bonds, is externally covered by compatiblizing organic groups R and reactive groups Y where R=organic substituent (H, siloxy, cyclic or linear aliphatic or aromatic groups that may additionally contain reactive functionalities such as alcohols, esters, amines, ketones, olefins, ethers or halides). Y includes but is not limited to OH, Cl, Br, I, alkoxide (OR), acetate (OOCR), peroxide (OOR), amine (NR 2 ) isocyanate (NCO), olefin, and R. The inorganic skeleton coupled with the peripheral groups combine to form chemically precise cage-like low density nanoscopic materials that improve the physical properties of a wide range of materials.
The size of POSS is roughly equivalent to that of most polymer dimensions, thus at a molecular level POSS can effectively introduce porosity into existing polymer morphologies (see Table 1).
TABLE 1
Relative sizes of POSS, polymer dimensions, and fillers.
Particle Type
Particle Diameter
Amorphous Polymer Segments
0.5
nm to 5 nm
Octacyclohexyl POSS
1.5
nm
Random Polymer Coils
5
nm to 10 nm
Colloidal Silica
9
nm to 80 nm
Crystalline Lamellae
1.0
nm to 9,000 nm
Fillers/Organoclays
2
nm to 100,000 nm
Representative formula for nanoscale POSS/POS chemicals that are desirable for incorporation into high performance polymers via nonreactive blending are the closed-cage homoleptic systems corresponding to the formula [(RSiO 1.5 )] Σ# and [(XSiO 1.5 ) n ] Σ# and the open-cage formula corresponding to functionalized homoleptic POSS [(RSiO 1.5 ) n (RXSiO 1.0 ) m ] Σ# and functionalized heteroleptic POSS [(RSiO 1.5 ) n (R′SiO 1.5 ) m (RXSiO 1.0 ) p ] Σ# and POSS resins [RSiO 1.5 ]∞.
These systems can be incorporated into high performance polymers through mixing with monomer or at the prepolymerization stages. The methods of incorporation involve high shear mixing, solvent mixing, milling and blending with high shear mixing being preferred. The level of property enhancement is dependent upon loading level, the size/shape and distribution of the POSS nanostructures and upon processing conditions. The loading levels range from 0.1% to 99% with levels of 10-30% being preferred.
Representative open-cage formula for nanoscale POSS/POS chemicals that are desirable for incorporation into high performance polymers via reactive blending and reactive grafting include monofunctional systems, difunctional systems and polyfunctional formulations (FIG. 4 ).
Representative formula for nanoscale POSS/POS chemicals that are desirable for incorporation into high performance polymers via copolymerization include both closed-cage and open-cage formulations and are shown in FIG. 5 .
While both open-cage and closed-cage nanostructures can be incorporated into identical formulations the open-cage nanostructures are desirable for formulations that required additional ductility. While the closed-cages are more rigid, they also provide formulations with enhanced modulus relative to open-cage nanostructures. Open-cage formulations containing residual silanol groups also show enhanced adhesion.
Monofunctional POSS-monomers are suitable for grafting onto high performance polymers as pendant side-chain groups and as chain terminators in the same manner as a traditional monoamine or monanhydride. Monofunctional POSS-monomers are particularly useful for reinforcing thermoplastics resins and for providing additional reinforcement to themoset systems. (Lee, A., Lichtenhan, J. D., Macromolecules 1998, 31, 4970-4974). Difunctional POSS-monomers are designed for direct copolymerization into the backbone of polymers in the same manner as a traditional diamine or dianhydride. Difunctional POSS-monomers are particularly useful for incorporation into thermoplastics systems yet can also be used as crosslinkers. Polyfunctional amines are ideally suited as crosslinkers, and adhesion promoters for thermoset systems.
The amine-functionalized POSS systems shown in FIGS. 4 and 5 have direct utility in imides, epoxies, urethanes, urea, novolac, and amide polymer systems. These same structural formula can also be modified with anhydride, epoxy, maleimide, oxazoline, cyanate esters, ester, acid, and alcohol functionalities that would render them desirable for incorporation into other high performance polymers such as nylons, polyurethanes, epoxides, cyanate esters, bismaleimides, polybenzoxizoles, polybenzimidizoles, polybenzthiozoles, polyesters, and phenolics.
Methods of Monomer and Polymer Synthesis
In order to prepare POSS-monomers and POSS-polymers economically and on a commercial scale, improved synthetic routes to several key materials have been developed. One of these processes involves the nitration and amination of aromatic POSS-systems to yield mono, bis or polyfunctional POSS-amines (FIG. 6 ).
Note this process is general and can be conducted on all types of POSS cages and resins. It is advantageous over existing methods because the reduction step is accomplished in one step at room temperature using inexpensive zinc metal and muratic acid both of which are commodity chemicals. Prior reductive methods have required the use of either expensive rare metals (e.g. Rh) or have required high temperatures and pressures.
Alternate methods of POSS-analine monomer synthesis include metal catalyzed coupling reactions by well known processes such as the Heck reaction, the Suzuki reaction, the Stille reaction and the Sona Gashira reaction. For example, the preparation of POSS-analine using the Heck route is most desirably accomplished through the reaction of a vinyl-functionalized POSS cage with an amine functionalized aromatic halide (or visa versa) in the presence of a palladium or nickel catalyst. The Suziki route yields POSS-analines by reacting an aromatic halide functionalized POSS with an amine functionalized aromatic halide in the presence of boronic acid and a palladium or nickel catalyst. The Stille method produces POSS-analines through the reaction of an aromatic halide functionalized POSS with a tin or silicon functionalized aromatic amine (or visa versa) in the presence of a palladium or nickel catalyst. The Sona Gashira method produces POSS-analines through the reaction of an acetylene functionalized POSS with an amine functionalized aromatic halide (or visa versa) in the presence of a palladium or nickel catalyst.
The incorporation of the various POSS-analine monomers into various types of polymers is straightforward. An advantage of the POSS-monomer technology over other related nano and filler technologies is that is designed to be used in turnkey fashion and does not require alteration of existing manufacturing protocols. Furthermore, it results in entirely new compositions of matter that utilize nanoscopic reinforcements directly polymerized into the polymer back bone. For example difunctional POSS amines are readily reacted with pyromellitic dianhydride (PMDA) and oxydianiline (ODA) to yield Kapton®-type polymers (FIG. 7 ).
The resulting POSS-polyimide copolymer is a tough yellowish resin with excellent thermal, mechanical properties as well as oxidative stabilities (FIGS. 8, 9 , and Table 2).
TABLE 2
Selected erosion and mechanical data for Kapton ™
and the POSS polyimide equivalent.
AO
Erosion
Youngs
*Tg
*Tg
Rate
Modulus
Tensile
Strain
(° C.)
(° C.)
Material
(cm 3 /atom)
(Ksi)
(Ksi)
(%)
air
N 2
Kapton ®
1
348
9.0
4.86
386
389
10% POSS-
0.1
370
10.8
6.59
380
381
Kapton ®
20% POSS-
0.01
321
7.5
3.89
370
373
Kapton ® 90%
Ultem ™
*Glass transition was measured via DMA. The Tg of Dupont's Kapton H is reported to range from 360-410° C. depending upon the method of measurement.
In comparison it was observed that POSS incorporation into polyimides results in an order of magnitude reduction of the erosion rate caused by exposure to atomic oxygen. These findings are consistent with the findings of Gilman et al. for POSS-siloxane copolymers. Additionally beneficial are the increases in modulus tensile and strain properties which indicate that POSS incorporation also improves toughness of these high performance materials. Analysis of these same materials through dynamical mechanical testing indicates the presence of a rubber plateau at 400° C. This rubbery region indicates that the POSS-reinforced systems are amenable to approximately a 50° C.-100° C. higher usage temperature relative to the non-nanoreinforced system. The increased usage temperature directly results from the POSS-entities controlling the motion of the polymer chains at elevated temperatures and thereby retaining mechanical integrity throughout a broader temperature range (despite the similarity in glass transition (Tg)).
In a likewise manner, POSS-amines can be reacted with fluorinated anhydrides such as 4,4′(hexafluoroisopropylidene)dipthalic anhydride (6-FDA) along with ODA to form colorless POSS-polyimides (FIG. 10 ).
In a likewise manner POSS-amines can be reacted with 4,4′-(4,4′-Isopropylidenediphenoxy)-bis(pthalic anhydride) (Ult) and ODA to form the nanoreinforced version of Ultem® (FIG. 11 ).
POSS-amines can be reacted with a wide range of other anhydrides such as 3,3′,4,4′-Benzophenonetetracarboxylic dianhydride (BPDA) along with ODA to form a wide range of nanoreinforced POSS-Imide copolymer. Combination of amine and anhydride ratios offers a tremendous ability to tailor mechanical and physical properties. (FIG. 12 ).
The incorporation of POSS/POS in to polyimide and related high performance polymer formulations can be accomplished through conventional blending and mixing techniques including both high and low shear mixing, milling, solvent and supercritical fluid assisted blending as well as through conventional polymerization techniques.
The degree of enhancement of physical properties is dependant upon the loading level of the POSS/POS component incorporated, the size of the silicon-oxygen cage, the size of the nanostructure (R-group effects), the nature of incorporation, and the interfacial compatibility between the nanoreinforcement and the polymer.
POSS/POS can be used both as a stand alone replacement or as an additive to existing high performance polymer formulations. POSS incorporation as an additive into existing polymer systems has been shown to effect significant improvements in mechanical and physical properties.
EXAMPLES
Alloying performance polymers with POSS/POS. Prior to mixing, all POSS/POS and polymers should be predried at 60° C. to 100° C. under vacuum for three hours or via a similarly effective procedure to ensure removal of traces of water or other volatiles. POSS/POS is introduced using a weight loss feeder at the desired wt % into the mixing vessel of a shear mixer containing the desired formulation components. The mixing residence time can be varied from 1 min to 60 min prior use of the formulation. Twin screw compounding is the preferred method of incorporation.
Solvent Assisted Application Method for Formulation. POSS/POS is added to a vessel containing the desired polymer, prepolymer or monomers and dissolved in a sufficient amount of an organic solvent (e.g. hexane, toluene, dichlormethane etc.) to effect the formation of one homogeneous phase. The mixture is then stirred under high shear at room temperature for 30 minutes and the volatile solvent is then removed and recovered under vacuum or using a similar type of process including distillation. Note that supercritical fluids such as CO 2 can also be utilized as a replacement for the flammable hydrocarbon solvents. The resulting formulation may then be used directly or stage-reacted for subsequent processing.
General Polymerization Method for POSS-polyimides. All monomers used are purified using standard recrystallization techniques. Using oven-dried glassware, and dry solvents, conduct the reaction under nitrogen. The corresponding anilines are added in 25 mL round bottom flask, in a nitrogen glove box and the anhydride is added to another 25 mL round bottom flask. 3 mL of purified N,N-dimethylacetamide (DMAc) is added to each flask. The anilines will dissolve, however the anhydride will form a slurry. The aniline solution is then transferred via syringe to a 250 mL 3-neck reactor flask equipped with a mechanical stirrer. The aniline flask is then wash twice with 1 mL of DMAc and the washes are added to the reactor. 5 mL of DMAc is added to the reactor. The anhydride slurry is then added to the reactor via syringe and the flask is also washed twice with 1 mL of DMAc. Upon addition of the anhydride to the reactor, the solution will turn yellow and homogenous almost immediately. The reaction is let run for 4 hours. A film is then cast from the resulting polyamic acid on a glass plate and placed in a clean oven with flowing nitrogen at 80 degrees Celsius for 4 hours. The temperature of the oven is then slowly raised to 300 degrees Celsius at which point the film is let cure for approximately 1 hour.
Nitration: Preparation of [(c-C 5 H 9 )SiO 1.5 ) 7 (O 2 NC 6 H 5 SiO 1.5 ) 1 ] Σ8 . A 10 gram sample of [(c-C 5 H 9 )SiO 1.5 ) 7 (C 6 H 5 SiO 1.5 ) 1 ] Σ8 was dissolved in approximately 150 of carbon tetrachloride. In a 500ml flask 50 mL of H 2 SO 4 followed by 50 mL of HNO 3 were added slowly while stirring. The mixture is then slowly transferred to a muratic acid solution and allowed to stir for 1 hr. The acid/POSS/CCl 4 solution is then slowly added to a 500 ml of chilled deionized water. The mixture is then transferred to a separatory funnel and extracted using three 25 mL extractions of CCl 4 . The bottom CCl 4 organic layer is then extracted with brine and neutralized with sodium bicarbonate. The volatiles are the removed under vacuum. The product may be further purified by dissolving in 75 mls of THF and precipitating into 300 mls of MeOH and dried to produce [(c-C 5 H 9 )SiO 1.5 ) 7 (O 2 NC 6 H 5 SiO 1.5 ) 1 ] Σ8 as a fine white powder (90% yield).
Reduction: Preparation of [(c-C 5 H 9 )SiO 1.5 ) 7 (H 2 NC 6 H 5 SiO 1.5 ) 1 ] Σ8 . A 5 gr sample of [(c-C 5 H 9 )SiO 1.5 ) 7 (O 2 NC 6 H 5 SiO 1.5 ) 1 ] Σ8 and 6 equivalents dissolved in THF in a 500 mL round bottom flask while stirring. To the resulting dark gray slurry, is added approximately 7 equivalents of concentrated (12M) HCl. As the reaction proceeds, the soln will become clear and any excess zinc will agglomerate and sink to the bottom of the stirring flask. The resulting ZnCl 2 that is formed is soluble in THF. The reaction is stirred for 1 hr, then filtered and taken to dryness. The resulting solid is then redissolved in a minimum of diethylether and precipitated into excess methanol, filtered and dried. The resulting [(c-C 5 H 9 )SiO 1.5 ) 7 (H 2 NC 6 H 5 SiO 1.5 ) 1 ] Σ8 is obtained in quantitative yield as an off-white fine powder.
Although the present invention has been described above, it will be appreciated that certain alterations or modifications thereon will be apparent to those skilled in the art. It is therefore that the appended claims be interpreted as covering all such alterations and modifications that fall within the true spirit and scope of the invention.
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Performance additives in high performance polymers using polyhedral oligomeric silsesquioxanes (POSS) and polyhedral oligomeric silicates (POS) as nanoscopic reinforcements, porosity control agents, thermal and oxidative stability aids to improve the properties of the polymers.
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BACKGROUND OF THE INVENTION
This invention relates to transmission of information between multiple digital devices on a network and between multiple networks on an internetwork. More particularly, this invention relates to a method and apparatus for allowing an intermediate system within a local area network (LAN) to transparently filter multicast packets from a wide area network or internetwork (WAN) directed to that LAN so that those packets are only delivered to end systems that wish to receive them.
Related technology is discussed in co-assigned U.S. patent applications Ser. Nos. 08/502,835, 08/313,674, now U.S. Pat. No. 5,568,469 and application Ser. No. 08/506,533, now U.S. Pat. No. 5,666,362.
Standards
This specification presumes some familiarity with the general concepts, protocols, and devices currently used in LAN networking applications and in WAN internetworking applications. One set of protocols used for networking within a LAN is the IEEE 802 protocol suite, available from the IEEE (Institute for Electrical and Electronics Engineers). These IEEE 802 protocols have been revised and reissued by the ISO (International Organization For Standardization) with the designation ISO 8802. Among the protocols specified in IEEE 802 are IEEE 802.3, the LAN protocols commonly referred to as Ethernet. A separate set of protocols used in internetworking, i.e. connecting multiple LANs, is referred to as the TCP/IP Protocol Suite. (TCP and IP are acronyms for Transmission Control Protocol and Internet Protocol.) The TCP/IP Suite is promulgated in a series of documents released by the Internet Engineering Task Force. The documents are referred to as RFC's (Requests For Comment) and are available over the Internet at URL http://www.cis.ohio-state.edu:80/hypertext/information/rfc.html or via FTP at ds.internic.net. An overview of concepts necessary for an understanding of the invention is presented below. For a more detailed discussion of background information, the reader should consult the above mentioned standards documents or a number of readily available reference works including Stevens, R. W., TCP/IP Illustrated, Addison Wesley, 1994.
FIG. 1
FIG. 1 illustrates a local area network (LAN) 40 of a type that might be used today in a moderate sized office or academic environment and of a type in which the present invention may be effectively employed. LANs are arrangements of various hardware and software elements that operate together to allow a number of digital devices to exchange data within the LAN and also may include internet connections to external wide area networks (WANs) such as WANs 42 and 44. Typical modern LANs such as 40 are comprised of one to many LAN intermediate systems (ISs) such as ISs 60-62 that are responsible for data transmission throughout the LAN and a number of end systems (ESs) such as ESs 50a-d, 51a-c, and 52a-g, that represent the end user equipment. The ESs may be familiar end-user data processing equipment such as personal computers, workstations, and printers and additionally may be digital devices such as digital telephones or real-time video displays. Different types of ESs can operate together on the same LAN. In one type of LAN, LAN ISs 60-61 are referred to as bridges and WAN ISs 63 and 64 are referred to as routers, however many different LAN configurations are possible, and the invention is not limited in application to the network shown in FIG. 1.
The LAN shown in FIG. 1 has segments 70a-e, 71a-e, and 72a-e, and 73a. A segment is generally a single interconnected medium, such as a length of contiguous wire, optical fiber, or coaxial cable or a particular frequency band. A segment may connect just two devices, such as segment 70a, or a segment such as 72d may connect a number of devices using a carrier sense multiple access/collision detect (CSMA/CD) protocol or other multiple access protocol such as a token bus or token ring. A signal transmitted on a single segment, such as 72d, is simultaneously heard by all of the ESs and ISs connected to that segment.
Packets
In a LAN such as 40, data is generally transmitted between ESs as independent packets, with each packet containing a header having at least a destination address specifying an ultimate destination and generally also having a source address and other transmission information such as transmission priority. ESs generally listen continuously to the destination addresses all packets that are transmitted on their segments, but only fully receive a packet when its destination address matches the ESs address. An ES such as 52g may transmit data with any other ES on the LAN by transmitting a data packet containing a destination address for the intended destination. If the intended destination is directly connected to the same segment, such as ES 52d, then ES 52d simply hears and receives the packet as it is being transmitted by 52g. If, however, the destination ES is not directly connected to the same segment as the source ES, then LAN 40 is responsible for transmitting the data to a segment to which the destination ES is connected. Generally, a source ES is not aware of whether a destination ES in its LAN is directly connected to its segment. The source simply transmits the packet with a destination address and assumes that the network will deliver the packet. Transmissions within the LAN are generally source driven, i.e. the LAN will deliver a data packet from a source to the destination address specified in the packet regardless of whether that destination ES actually wants to receive the packet. In general, packets contain user data that the user of an ES wishes to receive, such as portions of a data file which will be reassembled at the ES after all packets that make that file are received or portions of a video stream which will be displayed to the user. Packets may also be control packets, containing control information that is used to facilitate communication within the network.
Drivers, Adaptors, and LAN Topology
Each of the ISs and ESs in FIG. 1 includes one or more adaptors and a set of drivers. An adaptor generally includes circuitry and connectors for communication over a segment and translates data from the digital form used by the computer circuitry in the IS or ES into a form that may be transmitted over the segment. An ES such as 50b will have one adaptor for connecting to its single segment. A LAN IS such as 61 will have five adaptors, one for each segment to which it is connected. A driver is a set of instructions resident on a device that allows the device to accomplish various tasks as defined by different network protocols. Drivers are generally software programs stored on the ISs or ESs in a manner that allows the drivers to be modified without modifying the IS or ES hardware.
LANs may vary in the topology of the interconnections among devices. In the context of a communication network, the term "topology" refers to the way in which the stations attached to the network are interconnected. Common topologies for LANs are bus, tree, ring, and star. LANs may also have a hybrid topology made up of a mixture of these. The overall LAN pictured in FIG. 1 has essentially a tree topology, but incorporating one segment, 72d, having a bus topology. A ring topology is not shown in FIG. 1, but it will be understood that the present invention may be used in conjunction with LANs having a ring topology.
Bridges
The LAN ISs in LAN 40 include bridges 60-63. Bridges are understood in the art to be a type of computer optimized for very fast data communication between two or more segments. For example, bridge 60 is a computer having a processor, a memory for storing network information, connections to two or more separate segments, and a buffer memory for storing packets received from one segment for transmission on another segment. Bridge 60 receives packets from a source segment such as 70f, stores the packets, and then transmits the packets on another segment such as 70a, when the bridge detects that the other segment is silent. A bridge makes no changes to the packets it receives on one segment before transmitting them on another segment. Bridges are not necessary for operation of a LAN and in fact are generally invisible to both the ESs to which they are connected and to other bridges and routers. By invisible it is meant that a prior art bridge does not communicate any control packets to other devices in the network and facilitates communications between devices on two different segments in such a way that neither the sending device nor the receiving device is aware that the devices are not on the same segment.
At its most simple, a bridge temporarily stores any packet data received on one of its connections, or ports, and then, as each other port is available, the bridge forwards, or bridges, the packet out of each other port. Even at this most simple level, a bridge such as 60 tends to isolate network traffic on segments and reduces the chances of collision between packets. Modern bridges, as described below, also provide filtering functions whereby a bridge learns the LAN addresses of all ESs that may be reached through each of its ports and forwards packets only out of the port to which the destination ES of that packet is connected. Filtering bridges are enabled to quickly examine the LAN address of every received packet to determine whether and to which segment that packet must be bridged. As an example, when filtering bridge 62 receives a packet on segment 72a addressed to 52b, that packet is bridged only to segment 72b and not to segments 72c and 72d.
In order to accomplish this filtering function, a bridge must somehow know which ESs are attached to each segment connected to the bridge. Generally, this is done in one of two ways: a bridge may be configured by a human network manager to know the LAN addresses of the ESs connected to each segment, or a bridge may be enabled to learn the LAN address of ESs connected to each segment as the bridge is receiving packets. Bridges enabled to learn which ESs are connected to each of their segments do so by examining the LAN source address of packets received on a particular port. A self-learning bridge generally stores the information it learns from examining the source address of packets in a portion of the bridge's memory referred to herein as a Bridge Filtering Table (BFT). Once a bridge has placed entries in its BFT, upon receiving a packet, the bridge will examine the LAN destination address of the buffered packet and if, according to the BFT, the destination address is on the same segment from which the packet was received then the packet has presumable already been received by the destination ES and the bridge discards the buffered packet. If the destination ES is on a different segment from the originating ES then the bridge bridges the packet by transmitting it on the destination ES's segment. If the destination address is not present in the BFT, then the bridge must bridge the packet to all other segments to insure that the proper ES receives the packet. In this way, self-learning bridges gradually learn more and more about the ESs connected to them and gradually reduce unnecessary data flow through the LAN. In a prior art bridge, construction of the BFT and subsequent filtering of packets is accomplished transparently by the bridge without the need for the ESs to be aware of the bridge or to transmit any control packets to the bridge. A prior art bridge neither transmits nor receives control packets with other devices in the LAN.
Some prior art bridges implement an algorithm known as the Spanning Tree Algorithm which allows them to ensure that a segment that is connected to more than one bridge only receives packets from one of them. This algorithm is described fully in IEEE standard 802.1d.
LAN Broadcast and Group Address Packets
In the previous discussion, it was assumed that every packet in the LAN contained a destination address indicating delivery to just one destination. This is referred to in the art as a unicast packet. It is 5 also possible for a source in LAN 40 to transmit a packet to all the ESs in the network using a special address known as a broadcast address. A broadcast address is special destination address reserved by the LAN protocol for broadcast packets. In most LAN implementations, the broadcast address can never be a source address for a packet and therefore the broadcast address will never be entered into a BFT. Every bridge receiving a broadcast packet will attempt to find the packet's destination address in that bridge's BFT, will fail, and will therefore bridge the packet to all ports, which is exactly what is desired for a broadcast packet. As an alternative, a bridge may be pre-configured by its driver software to recognize broadcast packets and forward them to all ports.
In 802.3 Ethernet, Ethernet addresses are 48 bits. The broadcast address is defined as FFFF or all I's. 802.3 also defines a set of Ethernet Group Addresses, indicating more than one but less than all destinations. Ethernet Group Addresses are reserved addresses that cannot be assigned to any individual ES or IS. Within a standard prior art LAN, any packet having a Ethernet Group Address is broadcast to every ES in the LAN, and it is up to the individual ESs to determine whether they want to receive the packet based on that packets Group Address.
Routers
ESs within LAN 40 can communicate with any other ES in LAN 40 either directly if the ESs are on the same physical segment or through a bridge. However, if an ES wishes to communicate with an ES or other service on a different LAN, that data must be transmitted over a WAN such as 42. FIG. 2 depicts WAN 42. WAN 42 is a network of networks, or an internetwork. (The largest and most well known internetwork is the world-wide Internet.) WANs are generally comprised of a number of larger computers that are optimized for WAN transmissions, herein referred to as routers 64 and 68a-e. A router is a generally larger computer than a bridge, but, like a bridge, it too has a processor, a memory for storing network information, and connections to two or more separate segments. Some routers, like router 64, provide WAN services to a LAN and in addition can forward WAN packets through the mesh network to facilitate WAN communication. Other routers are multi-user multipurpose computers or file-servers that include routing functions. Still other routers are computers exclusively reserved for handling WAN data traffic.
Communication of WAN packets over WAN 64 via the routers is very different from packet communication within LAN 40 and occurs under a different protocol having a different addressing scheme. Unlike bridges, routers communicate control packets with every ES to which they are attached as well as to other routers in the WAN. A router uses information it receives via control packets and possibly configuration information supplied by a human operator to build a representation for itself of the network, which the router stores in a routing table. A router examines the WAN destination address of every packet it receives and uses information stored in its routing table to make an individual routing determinations about a packet based on the packet's destination address, other information in the packet's header, and the router's knowledge about the dynamic state of the WAN. Unlike a bridge, a router may make two different routing determinations for different packets with the same destination address based on the dynamic state of the WAN. A router such as 64 is generally unaware of the presence of any bridges within a LAN to which it is connected and sends all data into the LAN as though router 64 was directly connected to each ES within the LAN.
Typically, a WAN such as 42 will have a different addressing scheme and different packet structure than that used in the LAN. Every ES in LAN 40 that wishes to receive packets from WAN 42 must have assigned to it a separate WAN address. In TCP/IP, WAN addresses are 32 bits long and are generally written in a dotted decimal notation having values from 0.0.0.0 to 255.255.255.255. Router 64 learns the LAN address and the WAN address of every ES in LAN 40 and translates packets and addresses between LAN 40 and WAN 42.
FIG. 3 depicts a packet as it may be transmitted to or from router 64 on LAN segment 73a. The packet is essentially an Ethernet packet, having an Ethernet header 202 and a 48-bit Ethernet address (00:60:8C:19:AA) 204, and an Ethernet trailer 230. Within the Ethernet packet 200 is contained, or encapsulated, an IP packet, represented by IP header 212, containing a 32 bit IP address 214 (199.35.126.34). Packet 200 contains a data payload 220 which holds the data the user is interested in receiving or holds a control message used for configuring the network.
WAN Multicasting
WAN 42 may be enabled to route WAN multicast packets (WMPs) which are delivered only to those routers that request receipt of them. When running according to the TCP/IP Suite, routers and ESs accomplish multitasking through a special protocol referred to as the Internet Group Management Protocol (IGMP). In IGMP, a source that wishes to send WMPs will be assigned a special WAN multicast destination address from a list of addresses reserved by IGMP for multicast. Within LAN 40, WMPs are translated by router 64 into LAN packets having a LAN destination address that is a LAN Group Address. IGMP includes a direct algorithmic mapping between a WAN IP Multicast Address and a LAN Group Address. According to IGMP, a router such as 64 periodically queries ESs connected to it to report back to the router if they wish to receive any WMP streams. This query is broadcast within LAN 40 to one of the reserved Ethernet Group Addresses. An ES that wants to receive a WMP stream will respond to this IGMP Query by sending an IGMP Report back to router 64. The IGMP report is addressed to a LAN address that corresponds to the WMP address that the ES wishes to receive. An IGMP Report lists a WMP address that the ES wishes to receive. An ES sends a separate report for each WMP stream it wishes to receive. In the art, it is sometimes said that the ES joins a multicast group each time it indicates to the router that it wishes to receive a particular WMP stream. The router compiles the IGMP reports it receives from one or more ESs and then the router sends a request to other routers in WAN 42 requesting delivery of particular WMP streams.
Three details of IGMP are important for the following discussion. One is that an ES may leave a multicast group (i.e. stop receiving WMPs to that multicast address) at any time without informing the router that it no longer wishes to receive those WMPs. The ES simply does not respond the next time that the router sends an IGMP Query on the LAN. (Newer versions of IGMP allow an ES to send a packet telling the router that they no longer wish to receive a particular WMP stream, but these newer versions do not require ESs to do so.) A second important detail of IGMP is that in the case where a LAN such as 40 contains two routers with connections to the same WAN, the IGMP protocol includes a mechanism for preventing both routers from transmitting Query packets to the LAN. According to IGMP, when a router receives a Query packet on any of its LAN ports, it examines the WAN source address of that packet and if the source address is lower than the router's own WAN address, the router stops transmitting Query packets. Thus, eventually, only one router (the one with the lowest IP address) will transmit Query packets on any given LAN.
A final important detail of IGMP is that ESs monitor their segment and read any IGMP Reports that appear on their segment. According to IGMP, an ES does not send an IGMP Report for a WMP address if the ES detects that another ES on its segment has already requested that WMP address. The second ES will simply receive the WMPs as they are being transmitted to the first ES to request them. What this means is that under IGMP, a router never knows whether only one or more than one ESs on the LAN to which it is connected actually wishes to receive a particular WMP stream. The router therefore cannot direct WMPs to a particular ES LAN destination address, but must direct the WMP to one of the reserved LAN Group Addresses. As described above, within LAN 40, Group Address packets are delivered via the bridges to every segment in the LAN. Therefore, even if just ES 72b in LAN 40 requests a particular WAN MP stream, that WMP stream will be converted to a LAN Group Address and be delivered to every ES in LAN 40. In the case of a heavy WMP stream such as a video link, this can result in a huge amount of unwanted LAN traffic.
One prior art solution to this problem would be to reconstruct LAN 40 and replace each of the bridges 60-63 with computers that function more as routers. These "routers" would then be able to participate in the overall IGMP protocol and direct WMP packets only to those segments where they were wanted. This is an expensive proposition, however, increasing the cost of the LAN hardware infrastructure, LAN management, and likely decreasing the overall speed of the LAN.
Layers
A final background concept important to understanding the present invention is the concept of layered network protocols. Modern communication standards, such as the TCP/IP Suite and the IEEE 802 standards, organize the tasks necessary for data communication into layers. At different layers, data is viewed and organized differently, different protocols are followed, and different physical devices handle the data traffic. FIG. 4 illustrates one example of a layered network standard having a number of layers, which we will refer to herein as: the Physical Layer, the Data Link Layer, the Routing Layer, the Transport Layer and the Application Layer. These layers correspond roughly to the layers as defined within the TCP/IP Suite. (The 802 standard has a different organizational structure for the layers and uses somewhat different names.)
At the Physical Layer, data is treated as an unformatted bit stream transmitted from one transmitter to one or more receivers over a single segment. In IEEE 802, for example, the Physical Layer handles the encoding/decoding of physical transmission signals, the generation/removal of preambles for transmitted data used for synchronization (such as start and stop bits), and the bit transmission/reception protocol. Different Physical Layer protocols and devices exist for transmitting data as electrical signals, optical signals, or radio signals over wire, optical fiber, or other media. ES and IS hardware generally interact with the physical layer through adaptors that accepts binary data from the IS or ES and translate that data into signals transmittable on the medium. The adaptors includes the circuitry and connections necessary for communication over the medium. Adaptors for PCs are commonly available as standard bus cards which plug into a PC parallel bus and have a connector for connecting to the medium on which network signals are transmitted.
At the Data Link Layer (DLL) (sometimes referred to as Layer 2 or the MAC layer), data is treated as a series of independent packets, each packet containing its own destination address and fields specifying packet length, priority, and codes for error checking. A bridge is one type of device that assists with transmissions over the network at the Data Link Layer. IEEE 802 is primarily concerned with the data link and physical layers: Ethernet and Token Ring are two common protocols that operate at the Data Link Layer and Physical Layer.
At the Routing Layer (sometimes referred to as Layer 3), data is treated as a series of independent routing packets. A routing packet contains information necessary for correct delivery of the packet over a large WAN such as the internet. This information is used at the Routing Layer to transfer the packet through the network to its destination. A router is a device that assists with transmissions over the network at the Routing Layer. In the TCP/IP Suite, protocols that handles transmission at the Routing Layer include IP, IGMP, and ICMP.
At the transport layer, data is seen as a connection between two hosts on the network. Transport layer protocol in TCP/IP includes TCP and UDP.
The Application layer includes programs that a user interacts with to use network functions, such as e-mail, ftp, remote login, or http. Data at the application layer is often viewed as files.
An important ideal in layered standards is the ideal of layer independence. A layered protocol suite specifies standard interfaces between layers such that, in theory, a device and protocol operating at one layer can co-exist with any number of different protocols operating at higher or lower layers, so long as the standard interfaces between layers are followed.
To tie the concept of layers back to the preceding discussion, it may be seen that in LAN 40, WAN transmissions take place at the Routing Layer while LAN transmissions take place at the lower Data Link Layer. At the Routing Layer, ESs communicate control packets to the routers to which they are attached. However, at the Data Link Layer, ESs communicate no control packets with bridges and therefore ESs cannot participate in a multicast protocol at the Data Link Layer.
From the preceding it will be seen that what is needed is a LAN capable of correctly accepting and delivering WAN multicast packets to end systems that desire to receive them, but that does not experience the heavy amounts of undesired traffic generated in prior art LANs.
Further descriptions of LAN technology may be found in related co-pending and co-assigned applications such as U.S. Ser. No. 08/506,533 entitled METHOD AND APPARATUS FOR ASYNCHRONOUS PPP TO SYNCHRONOUS PPP CONVERSION incorporated herein by reference for all purposes.
For purposes of clarity, the present discussion refers to network devices and concepts in terms of specific examples, namely Ethernet and TCP/IP. However, the method and apparatus of the present invention may operate with a wide variety of types of network devices including networks dramatically different from the specific examples illustrated in FIG. 1 and described below. In particular, the present invention would have application within a set of proprietary WAN and LAN standards has been developed by Apple Computer Corporations and is referred to as Applelink and SMRP. It is therefore not intended that the invention be limited except as done so in the attached claims.
SUMMARY OF THE INVENTION
According to the present invention, an improved LAN is capable of receiving WMPs from a WAN via a router and delivering those WMPs only on segments having at least one ES that wishes to receive the WMPs. The invention accomplishes this by modifying layer 2 intermediate systems within the LAN to listen to layer 3 routing control packets and to make layer 2 filtering decisions based on information in the layer 3 packets. The invention includes a mechanism for a layer 2 intermediate system to generate layer 3 Query Packets when no higher level system is generating such packets in the LAN. The invention represents a substantial improvement over many types of prior art LANs where WAN MPs are flooded to every segment in the LAN. Under one embodiment of the present invention, no modification is required in the protocols or hardware of the ESs or the WAN. Stated another way, the present invention accomplishes filtering of Routing Layer (layer 3) packets at the Data Link Layer (layer 2), without the need for any modification of Routing Layer protocols. The present invention allows a bridge to forward WMPs selectively, based on Routing Layer requests from the ESs.
A bridge according to the present invention accomplishes these advantages by carefully monitoring all Routing Layer Multicast data and control packets and making forwarding decisions thereby. The bridge uses this information to augment its filtering database, thereby allowing for very fast filtering of unwanted WMPs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a local area network of one type in which the invention may be effectively employed;
FIG. 2 is a diagram of a wide area network of one type in which the invention may be effectively employed;
FIG. 3 is a diagram of an IP packet encapsulated in an Ethernet packet;
FIG. 4 is a diagram showing a layered network protocol;
FIG. 5 is a block circuit diagram of an improved bridge according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The following detailed discussion will describe the function of an improved bridge according to the invention in terms of a two protocol suites that have previously been discussed, 802.3 and TCP/IP. It will be understood to those of skill in the art that the invention also has application in other protocol suites employing an analogous multicast protocol.
FIG. 5 is a block diagram of a bridge 62 with improvements according to an embodiment of the invention. The bridge has five ports 80a-e which provide circuitry and connections that enable the bridge to communicate on each segment 72a-e. Packets received over any port are stored in Shared Packet Buffer Memory 82. Controller 84 reads each received packet and processes that packet based on the instructions specified in driver 86. Controller 84 includes connections (not shown) to each other bridge component for sending and receiving control signals.
As is known in prior art bridges, controller 84 maintains a Bridge Filtering Table (BFT) 88 in an area of memory separate from the packet buffer. As is known in the prior art, BFT 88 contains entries for each ES LAN address from which a packet is received. Each entry specifies the LAN address from which a packet is received and includes a means for indicating a port to which that address is connected. According to a default operation mode, bridge 62 gradually learns about ESs to which it is connected by reading the LAN source addresses of packets received on its ports. Once a bridge has identified a particularly ES LAN address and stored an identifier for the port to which that ES is connected in BFT 88, packets received at bridge 62 addressed to that LAN address are bridged only to the port to which the ES is connected. In this way, bridge 62 gradually reduces unnecessary traffic on the network.
According to the invention, bridge 62 is additionally enabled to filter IGMP multicast packets based on their LAN group address as follows. On power up or system reset or when none of its ports are designated Query Ports as described below, an improved bridge 62 according to the invention, acts as though it were a router and transmits IGMP Query packets at regular intervals out of each of its ports A-E. Initially, each of these ports are designated by bridge 62 as non-Query Ports. Bridge 62 transmits Queries with a fake WAN source address which is set to be a higher value than any possible WAN source address of a real IP router. This fake WAN source address is assigned to a bridge according to the invention. Standard prior art bridges do not have a WAN source address because they do not communicate at layer 3. In response to these Queries, ESs attached to bridge 62 that wish to receive WMPs will transmit Reports on their segments. These reports will be received at bridge 62. These Reports have a destination address equal to the multicast address from which the ESs wish to receive packets and the source address of the ES sending the Report. Each time bridge 62 hears a Report on one of its ports, it stores an identifier for the port and the LAN Group address in BFT 88 indexed according to that LAN Group Address and indicating on which port the Report Packet was received by placing a flag value in an appropriate location (in the example in FIG. 5, bridge 62 places a "1" in a column designating ports B and D wish to receive WMP packets addressed to Ethernet Group address 09:10:7D:00). When any subsequent packets are received at bridge 62 destined for that LAN Group, bridge 62 looks up the LAN Group Address in BFT 88 and forwards those packets only out of the ports specified in that group.
Whenever bridge 62 receives a Query Packet on one of its ports, it examines the WAN Source Address of the Query. If the WAN source address of the received Query Packet is greater than bridge 62's fake WMP source address, bridge 62 continues sending out its own Query Packets at a periodic interval and it marks the port on which the Query was received as a non-Query Port. If the WAN source address of the received Query Packet is less than bridge 62's fake WMP source address, bridge 62 stops sending out its own Query Packets and marks the port on which the Query Packet was received as a Query Port. In this way, a bridge according to the invention will always "lose" to a real IP router connected to a segment of the bridge's LAN. Alternatively, bridge 62 could examine a LAN source address to determine priority.
According to a further embodiment of the present invention, there may be different types of LAN intermediate systems according to the invention each having different capabilities. For example, in one LAN some ISs according to the invention may be fully IEEE 802.1d compliant bridges that therefore fully implement the bridge Spanning Tree Algorithm while other ISs according to the invention may not fully implement the Spanning Tree Algorithm. In this case it would be desirable in the LAN for an IS that is fully compliant with IEEE 802.1d to be selected as a fake router over an IS that is not fully 802.1d compliant. Accordingly, according to one embodiment of the invention, there are reserved two different fake WAN source addresses for LAN intermediate systems to use when they generate Query packets. The higher of these two fake addresses are assigned to the non-802.1d IS. In this case, when an IS receives a Query Packet on one of its ports, it examines the WAN source address of the Query. If the WAN source address of the received Query Packet is greater than the ISs fake WAN source address, the IS continues sending out its own Query Packets at a periodic interval and it marks the port on which the Query was received as a non-Query Port. If the WAN source address of the received Query Packet is less than the ISs fake WAN source address, the IS stops sending out its own Query Packets and marks the port on which the Query Packet was received as a Query Port. If, however, the WAN source address of the received Query Packet is the same as the ISs fake WAN source address, then the IS compares its LAN address to the LAN source address of the received Query Packet and designates the port a Query Port if the LAN source address of the received Query Packet is less than the IS LAN source address.
Once a port has been designated a Query Port, according to one embodiment of the invention, bridge 62 will maintain that designation until bridge 62 fails to see an IGMP Query Packet on that port within a specified timeout. After a timeout elapses, the port reverts back to a non-Query Port designation. According to a further embodiment of the invention, a bridge is able to cope with an idiosyncracy of IGMP concerning the timeout. In IGMP, the frequency at which a router sends out queries is not specified and there is no information in the IGMP Query Packet that indicates the interval. Therefore, it is not always clear what an appropriate time out for a given Query Port should be. According to this embodiment, a bridge will monitor the frequency at which Query Packets are received on a query port and will then set a timeout that is several times longer than the determined frequency. If no Query Packet is received on a query port for a timeout period, a bridge according to this embodiment will designate the port a non-Query port. When all ports on a bridge according to the invention are designated non-Query Ports, the bridge begins to generate and transmit Query packets.
On non-Query Ports, bridge 62 monitors IGMP Report packets and uses information stored therein to build the BFT. According to the invention, bridge 62 does not forward any IGMP Report packets out of non-Query Ports. Bridge 62 only forwards Report packet out of Query Ports. The reason for this is to prevent ESs on other ports from suppressing their IGMP Report packets because those ESs see another Report on the same LAN having the same WMP request. As explained above, in the IGMP protocol, in order to prevent all ES from each sending their own copy of the Report, ESs monitor all IGMP Report packets on their segment and if they see a Report go by that reports an WMP they are interested in, they don't request that WMP. However, bridge 62 does need to receive a separate Report packet from at least one of each of its segments so that it will know to which segments it must bridge WMPs.
One advantage of the present invention is that it may be implemented in a LAN such as 40 while requiring no new software in the ESs and no new protocol between the ESs and the routers or between the ESs and the bridges. In one embodiment, the present invention may be implemented by modifying some or all of the bridges in a LAN and making no other modifications to the LAN or WAN.
The invention has now been explained with reference to specific embodiments. Other embodiments will be apparent to those of skill in the art. In particular, method steps have been grouped and labelled as being part of various sub-methods in order to increase clarity of the disclosure, however, these steps could be differently grouped without changing the essential operation of the invention. It is therefore not intended that this invention be limited, except as indicated by the appended claims.
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A bridge (62) capable of reducing unwanted WAN multicast packet traffic in a LAN is disclosed. The bridge examines the contents of WAN multicast query and report packets and includes this information in its filtering database (88). The bridge designates ports on which query packets are received as query ports. When there is no WAN router generating multicast query packets into the LAN, the bridge simulates the behavior of a WAN router and generates WAN multicast query packets so as to cause report packet generation by end systems. A timeout interval for undesignating query ports and a method for determining an appropriate timeout for a port is disclosed.
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BACKGROUND
The invention generally relates to a system and technique for orienting and positioning a lateral string in a multi-lateral system.
A multi-lateral well includes a parent wellbore and one or more lateral wellbores that extend from the parent wellbore. Quite often, a main parent casing string lines the parent wellbore; and liner string(s) hang from the parent casing string and extend from the parent wellbore into the lateral wellbore(s).
Conventionally, for purposes of creating a multi-lateral well, the parent wellbore is first drilled and then cased with a casing string. A particular lateral wellbore may then be established by first milling a window (called a “parent casing window”) out of the wall of the parent casing string. The parent casing window forms the entry point of the lateral wellbore from the parent wellbore. After the lateral wellbore is drilled, a lateral liner string is run downhole so that the liner string hangs from the parent casing string and extends into the lateral wellbore. Depending on the particular multi-lateral system, the liner string may be cemented in place inside the parent casing string and/or may be sealed to the parent casing string.
It is often desirable to position the depth and orient the azimuth of the liner string with respect to the parent wellbore. For example, the liner string may have a window (called a “liner window”) that needs to be positioned at the correct depth and properly oriented for purposes of, for example, permitting fluid communication between the central passageway of the liner string and the central passageway of the parent casing string. Furthermore, the liner window when properly positioned and oriented may be used to provide mechanical access to the parent wellbore beneath the liner string window. This access may be used for purposes of an intervention into this part of the parent wellbore.
Conventional systems to orient the liner string include features that are located on the parent casing window. However, many such systems have typically been somewhat unreliable.
Thus, there is a continuing need for better ways to orient a lateral string with respect to a parent wellbore.
SUMMARY
In an embodiment of the invention, a method that is usable with a subterranean well that has a first string that lines a borehole includes running a second string into the well and engaging a deflecting face on a deflector to deflect the second string through a window of the first string. The technique includes performing at least one of positioning the second string and orienting the second string using a profile on the deflector downhole of the deflecting face.
Advantages and other features of the invention will become apparent from the following description, drawing and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a subterranean well according to an embodiment of the invention.
FIG. 2 is a more detailed view of a portion of the well of FIG. 1 according to an embodiment of the invention.
FIGS. 3 and 4 are flow diagrams depicting techniques to run a lateral liner string into a lateral wellbore according to different embodiments of the invention.
FIG. 5 is a top perspective view of the tubing deflector of FIGS. 1 and 2 according to an embodiment of the invention.
FIG. 6 is a cross-sectional view taken along line 6 - 6 of FIG. 5 according to an embodiment of the invention.
FIG. 7 is a cross-sectional view depicting initial engagement of the liner string with the tubing deflector according to an embodiment of the invention.
DETAILED DESCRIPTION
Referring to FIG. 1 , an embodiment 10 of a multi-lateral subterranean well in accordance with the invention includes a tubular string 20 that extends into a parent wellbore that is lined by a parent casing string 15 . The string 20 includes a packer 24 (shown in the set position) from which hangs a tubular liner string 30 . The liner string 30 extends through a milled casing window 38 of the parent casing string 15 and into a lateral wellbore 17 of the well 10 .
It is noted that the well 10 that is depicted in FIG. 1 is simplified for clarifying the following description. Thus, the well 10 may have other and different features in other embodiments of the invention. For example, in other embodiments of the invention, a well may include multiple lateral wellbores and liner strings.
For purposes of routing the liner string 30 into the lateral wellbore 17 , the well 10 includes a tubular, tubing string deflector (herein called the “deflector 40 ”), that is held in place generally concentric to the casing string 15 by means (an indexing casing coupler or a whipstock packer, as examples) known to those skilled in the art and is located beneath the casing window 38 . The deflector 40 includes a generally inclined deflecting face 42 that is sloped at an angle with respect to the longitudinal axis of the parent wellbore to deflect the liner string 30 (that generally follows the longitudinal axis of the parent wellbore before contacting the deflecting face 42 ) into the lateral wellbore 17 , as depicted in FIG. 1 .
As also depicted in FIG. 1 , in some embodiments of the invention, the liner string 30 includes a liner window 34 , a window that is formed in the wall of the liner string 30 (before the liner string 30 is run downhole, for example) so that when position at the appropriate depth and properly oriented, the liner window 34 provides access (via a longitudinal passageway 41 of the deflector 40 ) to the portion of the parent wellbore located beneath the window 34 . Thus, without the window 34 , access to and fluid communication with the parent wellbore below the window 34 is prevented.
As further described below, in some embodiments of the invention, a profile is formed on the deflector 40 to ensure proper positioning of the liner string 30 (to the appropriate depth) and proper orientation of the liner string 30 (at the appropriate azimuth) so that 1.) the liner window 34 aligns with the portion of the parent wellbore beneath the window 34 (and also faces the passageway 41 of the deflector 40 ); and 2.) the liner window 34 is located above the passageway 41 . This profile of the deflector 40 mates with a corresponding profile of the liner string 30 to, when the profiles engage, provide a positive indication (via a partial weight displacement of the string 20 ) at the surface of the proper depth and azimuth of the liner string 30 (and liner window 34 ).
Thus, as further described below, engagement of the two profiles is detectable at the surface of the well 10 to indicate that the liner string 30 is at the proper depth and azimuthal orientation. As a more specific example, in some embodiments of the invention, the deflector 40 includes a keyway profile that is constructed to receive a corresponding key profile of the liner string 30 when the liner string 30 has the appropriate depth and azimuthal orientation.
In some embodiments of the invention, the keyway profile of the deflector 40 is located below the deflecting face 42 so that when the deflector 40 is mounted to the inside of the casing string 15 (in a separate run into the well, for example), the casing window 38 exposes the keyway profile to the lateral wellbore 17 . The keyway profile is designed to provide a tracking range to, for a predefined range of potential azimuthal positions of the liner string 30 , rotate the liner string 30 into the proper final azimuthal position in which the liner window 34 is directed downhole and toward the opening of the passageway 41 . For purposes of coarsely adjusting the azimuth of the liner string 30 so that the key profile of the string 30 is within this tracking range, the string 20 may include a gyro 39 , in some embodiments of the invention.
For example, as depicted in FIG. 1 the gyro 39 may be located near the liner window 34 (in some embodiments of the invention) for purposes of providing feedback (via a telemetry path (not shown)) to the surface of the well 10 regarding the azimuth of the liner string 30 . Therefore, by rotating the liner string 30 in accordance with the feedback that is provided by the gyro 39 , the liner string 30 may be rotated to a position near its final proper azimuthal position, as the deflector's keyway profile (via its engagement with the key profile of the liner string 30 ) performs the fine rotational adjustment of the liner string 30 to place the liner string 30 at the final proper azimuthal position. At the conclusion of this fine rotational adjustment, the key and keyway profiles mate to offset at least some weight on the string 20 so that an operator at the surface of the well can detect the engagement. The packer 24 may then be set to hang the liner string 30 , in some embodiments of the invention.
In other embodiments of the invention, the coarse azimuthal positioning of the liner string 30 is established by a trial and error tactic in that the liner string 30 may be incrementally rotated and then lowered to see if engagement between the key and keyway profiles occur (as indicated by the partial weight displacement of the string 20 ); and if not, the liner string 30 is pulled back uphole and rotated by another incremental adjustment. Therefore, this process is repeated until the partial weight displacement is detected at the surface of the well 10 .
In some embodiments of the invention, to facilitate azimuthal orientation of the liner string 30 , the liner string 30 includes a swivel clutch 33 , a device that decouples rotation of an upper portion 28 of the liner string 30 from a lower portion 32 portion of the string 30 . Thus, due to the clutch 33 , the upper portion 28 of the liner string 30 may be rotated without rotating the lower portion 32 to facilitate azimuthal orientation of the liner string 30 .
FIG. 2 depicts a more detailed section 50 (see FIG. 1 ) of the well 10 . Referring to FIG. 2 , as shown, in some embodiments of the invention, the deflector 40 includes a keyway profile 60 that is constructed to receive and mate with a corresponding key profile 70 of the liner string 30 when the liner string 30 is in its proper final azimuthal and depth positions. The keyway 60 and key 70 profiles may be switched, in other embodiments of the invention, so that the keyway profile 60 is located on the liner string 30 , and the key profile 70 is located on the deflector 40 . Thus, many variations are possible and are within the scope of the appended claims.
Although specific keyway 60 and key 70 profiles are depicted in FIG. 2 , it is noted that these profiles are for purposes of example only to illustrate one out of many possible embodiments of the invention. For the embodiment that is depicted in FIG. 2 , the keyway profile 60 includes a slot 61 that is constructed to receive a corresponding radial extension 74 of the key profile 70 when the profiles 60 and 70 mate. Furthermore, as depicted in FIG. 2 , the keyway profile 60 may include a radial extension 62 that supports a corresponding radial extension 72 (of the key profile 70 ) that extends above the extension 62 when the profile 60 and 70 mate. The keyway profile 60 may include another radial extension 63 that extends below the radial extension 72 (of the key profile 70 ). The keyway 60 and key 70 profiles are also illustrated in a perspective view of the deflector 40 in FIG. 5 .
Referring to FIG. 3 , in some embodiments of the invention, a technique 100 may be used to run a liner string, such as the liner string 30 , downhole. Referring to FIG. 3 , the technique 100 includes lowering (block 102 ) the liner string 30 downhole and determining (block 104 ) whether the liner string 30 is near the deflector 40 . If not, then the lowering continues, as depicted in block 102 .
When the liner string is near the deflector 40 (as indicated by the deployed length of the string 20 , for example), then the technique 100 includes using a downhole survey mechanism (i.e., an azimuth orientation device) (such as the gyro 39 of FIG. 1 ) to rotate the liner string 30 to orient an upper section of the liner string 30 with respect to a milled casing window, as depicted in block 106 . Therefore, referring to FIG. 1 in conjunction with FIG. 3 , this rotation may include rotating the upper section 28 of the liner string 30 with respect to the lower section 32 . The bifurcated rotation is permitted due to the swivel clutch 33 . Referring to FIG. 3 , after this rotation, the liner string 30 is lowered (block 108 ) and a determination is made (diamond 110 ) whether engagement between the mating profiles of the liner string 30 and deflector 40 have occurred. If so, then the technique 100 ends. Otherwise, the liner string continues to be lowered downhole pursuant to block 108 .
Alternatively, in some embodiments of the invention, the liner string 30 may not include an azimuth orientation device, such as a gyro. Instead, a trial and error technique may be used to orient the liner string 30 with respect to the parent borehole. More specifically, FIG. 4 depicts another technique 130 for running a liner string downhole. Referring to FIG. 4 , pursuant to the technique 130 , the liner string is lowered downhole (block 132 ) and a determination is made (diamond 134 ) whether engagement has occurred between the key and keyway profiles of the liner string and deflector. If so, then the technique 130 ends, as proper azimuthal orientation and depth positioning of the liner string has occurred. Otherwise, a determination is made (diamond 136 ) whether the key profile of the liner string is past the keyway profile of the deflector, as depicted in diamond 136 . This may be determined by, for example, monitoring the length of the string that is used to position the liner string. If the liner string has not been lowered past the profile, then the liner string is continued to be run downhole, pursuant to block 132 .
If the liner string has been run past the mating profile, then the liner string is picked up to a location above the deflector, as depicted in block 138 . After this pickup, the upper section of the liner string is incrementally rotated (block 140 ) and the trial and error technique continues by lowering the liner string downhole pursuant to block 132 . Eventually, the liner string has the proper azimuthal orientation and depth so that the key and keyway profiles engage, as indicated by partial weight displacement that is detectable at the surface of the well.
FIG. 5 depicts a top perspective view of the tubing deflector 40 , in accordance with some embodiments of the invention. Referring to FIG. 5 , in some embodiments of the invention, the deflector 40 may be hollow (and thus, include the longitudinal passageway 41 ), and the deflecting face 42 may present an approximate U-shaped channel along about its longitudinal axis to guide the key profile of the liner string toward a narrowed region 160 that coincides with a longitudinal axis 150 (of the deflector 40 ). The longitudinal axis 150 , in turn, coincides with the keyway profile 60 of the deflector 40 . Referring also to FIG. 6 (depicting a cross-section of the deflecting face 42 along line 6 - 6 of FIG. 5 ), in some embodiments of the invention, the deflecting face 42 may include surfaces 162 and 164 that may be generally level, as depicted in FIG. 6 at the uphole end of the deflecting force 42 and increasingly slanted toward the longitudinal axis 150 at the downhole end of the deflecting face 42 . It is noted that in some embodiments of the invention, the surfaces 162 and 164 may not be inclined towards the longitudinal axis 150 . The surfaces 162 and 164 follow the perimeter of the channel around the entry of the passageway 41 of the deflecting face 42 to meet at the longitudinal axis 150 (at narrowed region 160 ) to guide the key profile 70 (see FIG. 2 ) of the liner string 30 toward the keyway profile 60 .
As a more specific example, FIG. 7 depicts the cross section of the deflector 40 shown in FIG. 6 , along with a cross-sectional view of the liner string 30 during the initial engagement between the key profile 70 of the liner string 30 and the deflecting face 42 of the deflector 40 . As depicted in FIG. 7 , the radial extension 74 of the key profile 70 extends into the open groove of the face 42 . As also depicted in FIG. 7 , separation between the inclined faces 162 and 164 provides a tracking range 180 that permits capture of the key profile 70 over a predetermined azimuthal range and guidance of the key profile 70 toward the longitudinal axis 150 and into the keyway profile 60 .
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, 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 technique that is usable with a subterranean well that has a first string that lines a borehole includes running a second string into the well and engaging a deflecting face of a deflector to deflect the second string into a window of the first string. The technique includes performing at least one of positioning the second string and orienting the second string using a profile on the deflector downhole of the deflecting face.
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This application is a continuation of a U.S. application Ser. No. 11/186,997, filed Jul. 20, 2005 now U.S. Pat. No. 7,131,375 patented Nov. 7, 2006, which, in turn, is a continuation of U.S. application Ser. No. 11/014,321, filed Dec. 16, 2004, now U.S. Pat. No. 6,981,444 patented Jan. 3, 2006, which, in turn, is a continuation of U.S. application Ser. No. 10/110,356, filed Aug. 5, 2002, now U.S. Pat. No. 6,848,364 patented Feb. 1, 2005, which, in turn, is a section 371 of international application no. PCT/US00/28379, filed Oct. 13, 2000, which, in turn, is a continuation-in-part of U.S. application Ser. No. 09/419,493, filed Oct. 15, 1999, now abandoned.
This invention relates to blankets for printing presses and in more particular to blankets for printing presses using a pre-manufactured or pre-made blanket material which is then formed on a sleeve.
BACKGROUND OF THE INVENTION
Prior art seamless cylindrical or sleeved offset printing blanket technology is well known in the industry and documented in several patents, for example, those assigned to Heidelberg Harris (U.S. Pat. Nos. 5,323,702; 5,429,048; 5,440,981; 5,553,541; 5,535,674 and 5,654,100) and to Reeves Brothers Inc. (U.S. Pat. No. 5,522,315) the contents of all of which patents are hereby incorporated by reference. Two examples of the prior art seamless sleeved blankets 10 A, 10 B are illustrated in the schematic drawings of FIGS. 1 to 3 . FIGS. 2 and 3 are taken in sections parallel to the circular end of the roll. For ease of illustration, the curvature of the roll has not been shown. The FIG. 2 version 10 A contains two windings of spiral wound thread 12 A and is typical of blankets produced by Reeves and Day (for the Heidelberg presses). The 10 A version also has a sleeve 14 A, usually of nickel, the spiral wrapped threads 12 A, a compressible layer 16 A made of typically a rubber containing microspheres, a reinforcing layer 18 A carrying another roll of spiral wrapped threads 12 A, made of rubber with threads being cotton, polyester or other materials, and the printing layer 20 A having a printing face 22 A. Of course, the blanket including its sleeve actually curve around forming a continuous cylinder. FIG. 3 showing the version 10 B, contains only one winding of spiral thread 12 A and includes a thick rubber base layer 14 B. This construction is typical of Sumitomo produced sleeves for use on Mitsubishi presses. This seamless cylindrical sleeve has the inner nickel sleeve 16 B, a compressible layer 18 B which can be joined to the base 14 B by an adhesive layer 20 B. A printing layer 22 B is provided and has a printing face 24 B. Again, the sleeve 10 B actually curves around to form a seamless cylinder as shown in FIG. 1 .
In the prior art, cylindrical offset sleeved printing blankets, such as discussed above, are produced by spiral winding carrier and reinforcing threads 12 A/ 12 B helically around a continuous sleeve 24 A/ 16 B. The sleeve is usually coated with an adhesion promoting primer. A first layer of polymeric coated thread is spiral wound onto the coated sleeve by passing the thread through a dip tank containing the solvated and uncured polymeric material as it is spiraled around the rotating sleeve. Dispersed in the polymeric material of this first layer are hollow microspheres that provide compressibility to the finished blanket. The amount of the coating is typically controlled as the thread exits the dip tank through a restrictive opening which must be large enough to allow the microspheres to pass through while small enough to prevent excessive coating and the resulting inability to dry and set the polymeric material before sagging can occur. The coating is relatively thick such that the solvents must be evaporated very slowly prior to curing to prevent trapped gasses from blowing unwanted voids in the finished layer. The long evaporation time tends to slow down the production rate. The polymeric material is then cured. The resulting compressible layer is very rough, uneven and overbuilt, requiring grinding to the required dimensions.
The polymeric material applied by this method tends to maintain its form around the diameter of the thread resulting in unfilled valleys between this layer and the coated sleeve. This unfilled area leads to gauge loss (thickness or diameter loss of a finished blanket sleeve—which can result in loss of printing contact) in the finished product and is sometimes compensated for by carrying out the additional steps by spreading a filling layer of solvated polymeric material onto the coated sleeve with a doctor blade set up prior to winding of the coated threads. Of course, all of the polymeric material may be applied with a doctor blade set up, as a calendered sheet or other methods known to the art and the threads omitted or spiraled around or under the applied polymeric layer.
After grinding the first inner layer to the required dimensions, a second outer layer of polymeric coated thread is wound around the sleeve in a similar fashion to the first layer; however, microspheres are not included. This layer serves as a reinforcing layer and stabilizes the overformed printing surface. Again, the polymeric material may also be applied with a doctor blade set up, as a calendered sheet or other method known to the art and the threads omitted or spiraled around or under the thus applied polymeric layer.
The overlaid printing surface may be applied as a solvated polymeric compound utilizing a doctor blade set up or as a solid by several methods known to the art such as any known extrusion or calendering process. The completed composite is cross wrapped or otherwise held in place, then cured with pressure applied to the outer layer by several methods known to the art to mold and adhere all layers together. In the final step the cured composite is again ground to the required dimensions in such a way as to provide a surface profile conducive to ink transfer.
This process results in a cylindrical offset printing blanket that is completely seamless throughout all of its layers but requires every step to be carefully performed on an individual, sleeve by sleeve basis. Efficiencies associated with mass batching of component parts are very limited, if not impossible. It has also been found that cylindrical offset printing blankets produced by this method tend to draw in the width, wrinkle or crease the paper web during use resulting in unacceptable side to side registration through successive printing units. In the prior art, to overcome this deficiency the compressible layer is profiled in a convex manner during the grinding operation to provide a spreading effect on the paper web, further requiring the individual processing of each sleeve during this step in the manufacturing process.
SUMMARY OF THE INVENTION
This invention utilizes a pre-made or pre-manufactured, unitary flat offset printing blanket made by any of the methods known to the art of flat offset printing blanket manufacturing to produce, in mass, a unitized composite blanket covering which can be applied, in a seamed fashion, to a continuous supporting sleeve, such that the seam has a negligible effect on print length and gap bounce. The pre-made blanket material will contain requisite reinforcements which are generally layed out in a rectangular manner, and are not spiral wound. The seam is preferably parallel to the longitudinal axis of the sleeve and not skewed ideally by more than 1/16″ of inch for a plate of 1/16″ of inch plate gap to avoid registration and print length issues. For other size plate gaps one could use other tolerance but preferably not larger than the plate gap. The opposing ends of the flat blanket should butt together as closely as possible but preferably leave some gap to provide a good fit should cut blanket lengths vary, and the resulting gap should preferably be narrower than the plate gap of the press for which the sleeve is designed if it is to be aligned in that manner. In this way, the two gaps (one in the blanket—the other on the press plate cylinder) can be aligned during use so that there is no loss of print area or it is limited to the plate gap area. Alternatively, the seam can be made to coincide with any non-utilized area of a plate cylinder, such as, for example, in the trim margins of adjacent print areas.
The invention may include a blanket index, location or locking system or the like, which could use a pin and opening or other mechanism and insures that the blanket and plate gap (or other chosen area) always match perfectly. Preferably, the gap between the opposing ends of the blanket can be filled with a resilient and solvent resistant compound to minimize gap bounce and especially to prevent water and solvents from wicking into the ends of the blanket. If this wicking is not prevented, swelling and delamination would be expected to occur.
In use, installation time is maintained at a minimum by providing a blanket in cylindrical or sleeve form when installed on the press's blanket cylinder. By utilizing flat blanket technology, there is no need for special profiling to spread the paper web. The unitized composite blanket covering may also be purchased as a standard material available from any number of offset printing blanket manufacturers and applied to a continuous supporting sleeve according to the method of this invention.
The sleeve could be made of metallic, for example, nickel or steel, or non-metallic construction, say a solid, laminate or winding of films, such as mylar or thermoplastics. The use of a non-metallic sleeve is possible as there is no need to vulcanize or subject the product to high heat to cure during manufacture.
OBJECTS OF THE PRESENT INVENTION
It is the object of this invention to provide a seamed offset printing blanket that maintains the benefits of the prior art (maximized print length, minimized gap bounce and reduced installation time) while reducing manufacturing time and expense.
It is an object of the present invention to provide a seamed sleeved blanket for a printing press.
It is another object of the present invention to provide a method for making a seamed sleeved blanket for a printing press.
It is yet another object of the present invention is to provide a method for using the seamed sleeved blanket of the present invention.
A still further object of the present invention is to provide a seamed sleeved blanket in combination with a printing press.
Yet a further object of the present invention is to provide a combination of seamed sleeved blanket, printing press and indexing, locating or locking system.
Another object is to provide a seamed sleeved blanket which can utilize a non-metallic sleeve.
These and other objects of the present invention will become apparent from the following specification and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a prior art seamless blanket showing where the sections shown in FIGS. 2 and 3 are taken along the lines 2 / 3 - 2 / 3 (the slash meaning “or”).
FIG. 2 is a cross-sectional view of a segment of a prior art seamless sleeved blanket with the actual curvature being omitted for simplicity.
FIG. 3 is a cross-sectional view of a segment of a second prior art seamless sleeved blanket with the curvature being omitted for simplicity.
FIG. 4 is a schematic view of the seamed blanket of the present invention showing where the section shown in FIG. 5 is taken along the lines 5 - 5 .
FIG. 5 is a cross-sectional view of a segment of an embodiment of seamed blanket of the present invention, with the curvature being omitted for simplicity.
FIG. 6 is a schematic view indicating how a sheet of the pre-manufactured blanket material is wrapped around the sleeve to make the seamed sleeved blanket of the present invention.
FIG. 7 is a perspective view of the sleeve of the present invention showing how it may be notched to index or lock it into place with respect to a press's blanket cylinder.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A schematic drawing of the seamed sleeved blanket 40 produced according to this invention can be seen in FIGS. 4 through 7 . As shown in FIG. 6 , according to this invention a conventional, flat offset printing blanket material 42 may be manufactured by methods well known to the art or purchased in roll form and cut to specific dimensions so that it can be wrapped (as indicated by the large arrows) as a solid sheet around a continuous supporting sleeve 44 to produce the seamed sleeved blanket 40 of the present invention and shown in FIG. 4 , the gap or seam being given numeral 45 . Referring to FIG. 5 , preferably the following construction method can be used. The blanket material 42 could be of any desired commercially available structure and could have a rubber surface 46 , say 0.023 inches thick over a first outer fabric layer 48 (reinforcement), say 0.009 inches thick, over a compressible layer 50 , say 0.014 inches thick, over a middle fabric layer 52 (reinforcement), say 0.011 inches thick, over an adhesive layer 54 , say 0.0002 inches thick, over an inner fabric layer 56 (reinforcement), say 0.015 inches thick. The sleeve could be metallic or non-metallic, and if metallic, preferably of nickel. The expandable nickel sleeve has been the sleeve of choice for sleeve offset blankets. There are alternative materials that can be used such as fiberglass, kevlar, plastic, and/or polyethylene (PET) sleeve. Some of these materials and particularly PET have several advantages over the nickel: lower cost, safer for the operator (no sharp edges), more durable than nickel in the manufacturing and pressroom environment. While the reinforcement shown was fabric, other conventional reinforcements could also be used. The sleeve 44 would be treated with a primer 58 , say 0.002 inches thick, and covered with a urethane or other adhesive 60 , say 0.002 inches thick, that bonds or adheres the blanket material 42 to the sleeve 44 . The across the roll dimension may be cut equal to or less than the length of the sleeve 44 and the around or circumferencial dimension may be cut equal to or no more than 1/16″ less than the outer surface length or circumference of the sleeve for use on a press with a plate gap of 1/16 of an inch. Of course, for other size plate gaps, this dimension could very. The ends 62 and 64 (of FIG. 4 ) of the flat blanket material 42 may also be cut or skived at an angle so that the ends meet in the seam 45 (indicated by the heavy double arrow in FIG. 5 ) generally flush from top 68 (outer surface) to bottom 70 (inner surface) (see FIG. 5 ) when wrapped around the sleeve 44 . The roll goods from which the cuts are made may be of any length and width common in the industry but should be maximized to provide the greatest number of cuts possible without excessive cutting waste. Manufacturing or purchasing in this form takes advantage of the efficiencies associated with mass production. It is well known that the wider and longer a roll of printing blanket material is produced, the less the cost per unit area.
The requirements of the flat offset printing blanket material 42 are the same as for any offset printing blanket and may vary according to the specific end use. A typical blanket physicals are: compressible layer 0.008 to 0.014 thick, stretch less the 1.25%, ply adhesion>2 lbs./linear inch, tensile stretch>300 pounds/linear inch, Shore A Durometer 70-85. Additionally, the printing face 72 usually will be overbuilt for grinding of the finished product to the required dimensions. The preferred printing blanket construction according to this invention is one containing one or more, but preferably, three plies 48 , 52 and 56 of reinforcing fabric bonded together with an adhesive or solvent polymeric resistant cement, preferably a nitrile cement is used. Alternatively, nonwovens, films or other supporting substrate, could be used instead of fabric. As the blanket material was pre-manufactured, the reinforcement generally will not be spiral wound but will run parallel and perpendicular at right angles to the center axis of the blanket cylinder axis and/or the axis of the blanket sleeve when installed on the blanket cylinder. It is believed that the absence of non-spiral windings in the present invention is beneficial to printing, keeping registration and avoiding web draw in. The blanket material should preferably contain a compressible or foam layer 50 between the two upper fabric plies 48 and 52 that is uniform in thickness across the width. This carcass construction should be in a range of 0.025 to 0.070, and preferably, approximately 0.055 inches in thickness. Of course other thickness could be used. A solvent resistant polymeric printing face 46 preferably made of nitrile or nitrile blends with other polymers is applied over the top ply of fabric and should be in a range of 0.010 to 0.070 and preferably no less than 0.044 inches thick so that the total gauge of the finished flat blanket is in a range of 0.030 to 0.110 and preferably approximately 0.096 inches thick.
After the individual pieces of blanket material 42 are cut to the appropriate size to fit around the sleeve, they are dried in an oven, for about 30 minutes at, for example, 150° F. to remove moisture or otherwise treated to remove moisture. Note, the blankets' sleeve is not subject to this drying, making the use of many non-metallic sleeve materials possible. The dried or moisture free blanket 42 is coated with a thin layer of self-curing polymeric material, preferably urethane 54 such as Por-A-Mold S-2868 manufactured by Synair. These self-curing urethanes are hindered by water so that moisture left in the blanket material 42 will prevent adequate cure and adhesion. The coated blanket is then wrapped around the sleeve 44 . The sleeve 44 has a thickness ranging from 0.002 to 0.010, and preferably 0.005 inches thick. The continuous sleeve may be made of suitable expandable or stretchable metal, and preferably nickel. The sleeve and completed blanket should be expandable or stretchable as that is the usual manner in which they are installed on a blanket cylinder. That is, the sleeve is expanded or stretched with air pressure to permit it to be so installed.
Other bonding materials may be used but often require heat activation. Application of heat to the already cured flat blanket can degrade its physical properties.
Nickel sleeves 22 are preferred but any sleeve, made of a rigid or semi-rigid material and having a Youngs Moduus and thickness that allows it to be expanded sufficiently to slip over the printing cylinder during installation and removal while retracting to fit the outer diameter of the cylinder tightly during use, may be used. As noted, it is possible to use non-metallic materials for the sleeve in the present invention as the sleeve never need be exposed to high temperatures. The sleeve dimensions must be chosen so that the interference between the inside diameter of the sleeve and the outside diameter of the printing cylinder on which it will be mounted prevents slippage around the cylinder during use. For example, 0.005 inch thick nickel sleeve should have an inside diameter of 0.002 to 0.020 less than the outside diameter of the blanket cylinder on which it will be mounted.
The sleeve 22 is first treated and primed (see FIG. 5 , numeral 58 ) in a manner common to the art and further coated with the self-curing urethane. The preferred primer is a single coat primer such as Pliogrip 6025, marketed by Ashland Chemical. Two coat primer systems may also be used.
The urethane or other coating is preferably applied to the back of the flat blanket by a doctor blade to completely fill the interstices of the fabric backing increasing the overall blanket thickness minimally or not at all. The urethane coating is applied to the sleeve by brushing but may also be applied by dipping, spreading with a doctor blade, spraying or other methods known to the art. The adhesive thickness may vary depending on the adhesive system used and should be consistent with the adhesive manufacturer's directions.
Hydrogenated nitrile rubber compounds have been successfully used in place of the urethane as solvated and spread adhesives or as calendered adhesive sheets. This method requires curing of the completed composite under pressure and at elevated temperatures while the urethane can be cured at room temperature. Of course, there are many other non-rigid adhesives that can be used to bond the blanket to the sleeve, such as acrylics or rubber based adhesives. They are only limited by the need for solvent and water resistance.
The ends 62 and 64 of the blanket are butted to each other such that the joint or seam 45 runs preferably parallel to the longitudinal axis of the sleeve. This butt joint should not be skewed by more than 1/16″ to prevent misregistration (see discussion above), short print, walking, or unacceptable movement of the printed web.
While being manufactured, to hold the flat blanket material in place on the sleeve, it may be secured in place with clamps and spiral wrapped with mylar or other tape under controlled tension (2-10 lbs./in.), removing the clamps as the tape spiral traverses the length of the sleeve. The mylar or other tape is butt or spiral would in such a way that successive wraps overlap one another sufficiently (5 to 95%—preferably, 40 to 60%) to apply pressure to the entire surface of the blanket. Alternatively, the blanket may be secured with adhesive tape prior to wrapping with mylar and/or the entire blanket may be enclosed in a mold that simultaneously holds the blanket in position and applies the appropriate pressure. The self-curing urethane cures and bonds the flat blanket to the primed nickel sleeve within 24 hours at room temperature. This cure rate can be accelerated with exposure to elevated temperatures, so long as those temperatures do not degrade the product. 150° F. is a good curing temperature that would reduce the cure time to about 8 hours. The mylar tape or mold is then removed.
This invention includes the concept of using a manufacturing fixture or mold to improve the manufacturing quality of the blankets. The idea is to use a device such as a manufacturing fixture or a mold that would allow the seam to be located, aligned precisely, and securely held during the curing process. The fixture would also apply even pressure on the surface of the blanket after it has been wrapped around the tubular sleeve. This replaces the manual method of “wrapping” the blanket prior to curing the bonding agent. The result is that the blanket quality can be reproduced consistently. The skill level of the manufacturing person is not as critical. It will also lend to automating the entire manufacturing process in order to reduce the cost and increase the quality. For example, the mold or fixture would be generally “C” shaped in cross-section and closed by over center clamps that pull the mold or fixture closed. That is, the “C” closes upon itself to form an “O”, with the blanket material sleeve in the center of the “O”. After the material cures, the blanket sleeve is released from the mold and finished, as by grinding on its outer surface.
The remaining gap 45 , if any, between the opposing ends of the blanket, can be filled with the urethane or nitrile material and allowed to cure adhering the two ends together and providing a suitable surface. The gap 45 should be filled with a resilient and solvent resistant compound to minimize gap bounce and to prevent water and solvents from wicking into the ends of the blanket. Of course, if the ends 62 and 64 are really a close fit or touching, then only sealing may be needed to prevent wicking, any such small or negligible gap not needing further filling.
It is also preferred that when used the gap filler material be of a different color from the blanket face so that the seam location is easily identified for proper alignment during installation. The same urethane is also utilized to seal the blanket materials 42 edges and prevent wicking into the sides of the blanket. The different color seam and a mark on the blanket cylinder could form part of an indexing system for properly locating the seam. Of course, another indicator than the seam could also be placed on the blanket cylinder and used with an appropriate mark on the blanket cylinder for indexing purposes.
Grinding to the appropriate diameter and surface roughness finishes the composite seamed cylindrical blanket. The diameter is specific to the press on which the sleeve will be used should be such that, in combination with the blanket's compressibility, excessive pressure does not cause slippage around the print cylinder. The appropriate surface roughness is achieved by selection of the face compound and grinding media. The “roughness average” (Ra) should be in the range of 0.2 to 2.0 microinches.
Prior art cylindrical blankets are typically built with a minimally thick composite covering the nickel sleeve. This results in excessive heat transfer to the cylinders on which they are mounted. During grinding, the heat transfer to the grinding mandrel can cause distortions requiring two stage or wet grinding. The blanket is first rough ground, allowed to cool and then finished. The thickness of the composite covering of this invention is such that heat transfer is negligible. Grinding may be accomplished in a single step and without the mess or capital expense associated with wet grinding.
According to this invention, multiple flat blanket pieces may be seamed together on a single sleeve for use on presses having multiple printing plates and thus multiple plate gaps. Such a blanket would have seams corresponding to the plate gaps and could be made to register with them. Also, according to the present invention any seam or seams on the sleeved blanket could be set up to fall in any corresponding area on the plate cylinder that did not interfere with useful printing.
The use of a mold to hold the flat blanket in position and apply pressure while the urethane cures allows for the possibility of using pre-ground or cast face blanket coverings. The impressions left by cure tapes/wraps require grinding of the finished sleeve, while the use of a mold leaves no such impressions. In this method, the gauge of the flat blanket material 42 covering and the outside diameter of the nickel sleeve control the outside diameter of the finished sleeve. Surface profiles are imparted in mass to the rolls of flat blanket material prior to cutting by methods well known to the art and reduce another unit by unit processing step.
The manufacturing costs associated with the prior art are high and the process is very slow. Output from the method of the present invention is three to four times higher than that of the prior art. And much of the auxiliary equipment such as blanket curing ovens, winding lathes, etc., are not needed. Production or purchasing of the blanket material covering in roll or flat form and large quantity significantly reduces the cost and individual seamed sleeves of the present invention can be completed at a rate of at least one every hour on the same machinery without the auxiliary equipment.
Unit to unit variations are common in the prior art. According to this invention, all seamed sleeves of the present invention produced from the same master roll of flat blanket material will be very consistent in properties.
In the prior art, there are no reinforcing or stabilizing threads in the horizontal direction. The threads applied in the circumferencial direction are not parallel to the end plane of the sleeve. It is possible that this thread orientation is responsible for the tendency to draw in the paper web during use and the consequent side to side misregistration from printing unit to printing unit. The seamed cylindrical blanket of this invention provides threads both perpendicular and parallel to the axis of the sleeve and no such registration shift issues occur. The need for profiling the compressible layer is not necessary.
Prior art seamless, sleeved or cylindrical blankets have historically slipped fractionally around the printing cylinder during use which causes print distortion. The proper combination of the blanket compressibility and finished outside diameter of the secured sleeved blanket of the present invention has been found to eliminate this slippage.
In addition, sleeves may be used in the invention that are made of plastic, rubber, fiberglass, kevlar or other suitable materials having appropriate elasticity characteristics. Since our invention requires no final vulcanization process, sleeve materials with softening point less than 300° F. can now be considered for use. This was not possible with cylindrical blanket made by the prior art.
This invention also provides for a sleeve to blanket cylinder lock up system. The lock up system guarantees that once the blanket is installed if will not slip circumferentially or axially on the blanket cylinder. This movement has been a problem with prior art. For example, a notch or opening 80 could be provided in the sleeve which cooperates with a raised portion or pin 82 (indicated in dashed lines in FIG. 7 ) on the plate cylinder. Other suitable two part mechanisms or male and female portions that fit together could also be used, one in the sleeve with the other in the plate cylinder. Should a full locking system not be desired or needed, the sleeve and plate cylinder could be provided with appropriate indexing marks to locate the seam in the desired area, be it in the plate gap or other non-utilized non-printing area of the plate on the plate cylinder of the press.
While the preferred form of seamed, sleeved blanket and method of making and using the same of the present invention have been disclosed and described, it should be understood that other equivalent steps and elements of those called for in the below claims fall within the scope of the appended claims.
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An offset lithographic printing press combined with a gapped or seamed cylindrical offset printing blanket having pre-made blanket material mounted on a cylindrical sleeve is disclosed, wherein conventional, manufactured blanket material in flat form is adhered to a cylindrical sleeve to economically produce a cylindrical sleeved blanket. The leading and trailing ends of the flat blanket material are joined in close proximity such that a small gap is formed. A seam may be made with a filler material that fills the remaining gap resulting in a seamed sleeved blanket. In use, the blanket's printing surface, which excludes the gap or seam, is aligned with the printing plate's image-bearing surface. Consequently, no loss of print length results from the gap or seam.
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RELATED APPLICATION
[0001] This present disclosure relates to subject matter contained in Japanese Patent Application Number 2008-335442. (filed on Dec. 27, 2008) which is expressly incorporation herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a carbide bar for a dental rotary instrument, wherein the bar is adopted for the dental instrument as a cutting and polishing tool for a dental artificial subject. Thus, the carbide bar is set to dental hand piece accordingly. This developed bar especially attains effective cutting and smooth polishing for dental materials such as plasters or plastics and eliminates prior defects accordingly.
[0004] 2. Description of the Prior Art
[0005] A carbide bar is normally used in dental instrument and it is made of tungsten carbide as cutting portion while the carbide portion is adhered or waxed in chemical method onto a shank which is made by such as stainless bar, and then it is finished into a proper shape so that it can be used properly for the dental instrument. Then the shank is firmly screwed into the bottom handle of the hand piece. This carbide bar has good durability so that it may be used for cutting and polishing a wide range of dental materials such as plasters, ceramics, metals, and so on.
[0006] The carbide bar in general, as shown in FIG. 1 , has plural blades which are twisted gradually rightward from a bottom to a top portion. When the bar is rotated in right turn same as a rotation work, the cutting and polishing is started. However, when some extra and big force is caused for the working procedure, the fastening force between the bar and the bottom hand piece is gradually to grow loose and finally it results for direction of de-screwing therebetween. Thus, it is worried that the carbide bar is fallen off from the hand piece, and it may cause some dangerous situation for the worker.
[0007] At the same time, in this prior art, while the cutting and polishing are performed, cutting dusts are caused and are unavoidably accumulated among the blades, and therefore this accumulation causes a problem for smooth cutting and polishing, and sometimes it is required to clear those dusts there from even during the working time. Especially for wet materials or else for water supply in the performing process, the dusts are increased among the blades, whereon the cutting efficiency is largely deteriorated.
[0008] The performing work in this prior art may also promote to scatter the dusts toward the worker, and thus the working efficiency is also badly influenced.
[0009] As explained in the prior art, it has some problems to be cleared to perform the cutting and polishing works. As the blades are twisted rightward from the bottom to the upward, the carbide bar is afraid to be loosened and to be fallen off from the hand piece during round rotation work, so that it may cause the dangerous situation for the user. Also, thus the caused dusts are unavoidably accumulated during cutting process among the blades, which may cause ill performance of the work in efficiency for cutting and polishing. At the same time, during these cutting and polishing process, these accumulated dusts are required to be cleared off because the situations may affect smooth process thereof. Especially for cutting wet materials or continuing the relative cutting work with water supplying, the dusts are increased among the blades. In order to clear this situation, the worker has to stop his continued work to clear them. Thus, the caused dusts might be scattered against the worker for low efficiency of the work.
SUMMARY OF THE INVENTION
[0010] In view of explained defects, the present invention has been developed.
[0011] This invention has an object to provide a carbide bar for dental rotary instrument which can cut and polish dental materials smoothly with good efficiency in safe manners without inviting accumulated dusts too much. For this developed bar, it is now more required to attain smoother finish for the polishing surface than performing a great deal of cutting and polishing work.
[0012] This invention has now adopted the carbide bar with plural blades which are twisted gradually leftward from a bottom to a top portion, wherein loading force between the bar and the hand piece is always maintained against the operating rotation to keep the connection between the bar and the hand piece. At the same time, the caused dusts are reduced for depositing between the blades and are not scattered against the performing worker. By this adoption, the danger where the bar is loosened and departed from the hand piece is avoided while accumulation of dusts between the blades and scattering of the dusts toward the performing worker are also eliminated.
[0013] When preparing an artificial dental material, surface of the material should be produced as smooth as possible, and this smoothness attributes to adaptation feeling for an user of this material and also promotes to reduce adherence of oral plaque during actual use for the user. Thus the smooth finish for the material is necessary for using the submitted materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a front view of a carbide bar used in the prior art, wherein plural blades are twisted slightly and gradually rightward from a bottom to a top portion.
[0015] FIG. 2 is a front view of a carbide bar developed by the present invention, wherein plural blades are twisted leftward from the bottom to the top portion.
[0016] FIG. 3 is a front view of a carbide bar, showing a first embodiment developed by this invention.
[0017] FIG. 4 is a front view of a second embodiment for a carbide bar having the other shape of blades developed by the invention.
[0018] FIG. 5 is also a front view of a third embodiment for a carbide bar having another shape of blades developed by the present invention.
[0019] FIG. 6 is a plan view of top blades portion for the embodiment 1, wherein blade composition can be clearly seen by this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The preferred embodiments shall be explained below with Figures from 1 to 6 , but prior to the explanation, we should like to emphasize below.
[0021] After various and actual experiments in trial and error manners, the following merits are found by the inventors. The number of the blades to be adopted in this invention should be composed of 6, 7 and 8. In theory, when the blades number is increased, the cut and polished surface become smoother, but the blades over the FIG. 8 pieces do not have enough gaps between the blades to incur the stacking of the caused dusts. Accordingly, the number of the blades to be 6, 7 and 8 is recommended. It is also recommended that the maximum pitch for the blades is between 2.0-2.5 mm should be adopted. With regard to the type of the blade, it is also recommended to adopt plane-cut type, not cross-cut type, because the cross-cut type blade may invite harsh surface.
[0022] The size for cutting and polishing portion is recommended to be 3-15 mm, preferably 10-15 mm. The diameter of the portion should be 3-10 mm. This diameter means the maximum size around the portion.
[0023] Form of the adopted carbide bar is optional, but it is now preferable to produce the form in a bullet type or a cylinder type as shown in the Figures.
[0024] As repeated, the numbers of the blades should be 6, 7 and 8.
[0025] The angle of the blade should be between 55°-80°, preferably 60°-75°.
[0026] FIG. 1 is a front view of a carbide bar used in the prior art, wherein plural blades are twisted slightly rightward from a bottom to a top portion. A numeral 4 shows a loading force caused by cutting and polishing work, while the numeral 5 shows the force to be carried by the bar.
[0027] FIG. 2 shows a front view of the carbide bar developed by this invention, wherein plural blades are slightly twisted leftward from the bottom to the top portion.
[0028] FIG. 3 and FIG. 4 are front views of the carbide bars developed by the present invention as Embodiment 1 and Embodiment 2, wherein the numeral 1 shows the cutting and polishing portion while the numeral 1 a shows a blade while the numeral 2 shows a shank.
[0029] FIG. 5 is also the front view of Embodiment 3, wherein the other cylinder shape of the bar adopted and this cylinder shape is devised to be smaller toward top from the bottom like a conical form.
[0030] With reference to FIG. 6 , it shows a plan view of a top portion for the cutting portion of the carbide bar, and this is the Embodiment 1 as above shown. A numeral 6 is the surface ditch of the blade. This cutting portion of the carbide bar should not be preferably as the blade in the tip end, and at this tip end a part of ditch portion should be formed. The ditch surface of this tip end should be preferably inclined at a angle against an axis, and further this blade tip should be formed in contrast angle to the center of the axis.
[0031] Now, the actual embodiments are performed. The Embodiment 1 (Emb.1) is performed with the cylinder type in FIG. 3 , while the Embodiment 2 (Emb.2) is also performed with the bullet type in FIG. 4 , where the blades are twisted leftward with adoption of 8 pieces and with the plane cut system. The experiment is now performed by the dental hand piece engine at 10,000 rpm, for 30 seconds, where a super hard plaster and an acryl plate are cut and polished for testing, and at the same time the super hard plaster in wet condition is also tested in the same condition for confirming the cut dust stacking. In this test, a comparison tests (Com.1, Com.2 and Com.3) are also performed in the conditions that Com.1 is equipped with leftward twisting blades in the same cylinder type adopting 4 pieces blades in the plane cut, and Com.2 with leftward twisting blades and with 4 pieces blades in the plane cut while Com.3 with rightward twisting blades and with 10 pieces blade in cross cut. This test results were now shall be produced in next pages in Table I and Table II as follows:
[0000] For these Tables, an abbreviation can be referred and used as below.
Emb.1=Embodiment 1
Emb.2=Embodiment 2
Emb.3=Embodiment 3
Com.1=Comparison Test 1
Com.2=Comparison Test 2
Com.3=Comparison Test 3
Com.4=Comparison Test 4
Com.5=Comparison Test 5
[0032]
[0000] TABLE I Emb. 1 Com. 1 Form of bar cylinder cylinder Type of blade leftward leftward twisted twisted Plane cut plane cut Number of blades 8 pcs 4 pcs At the time Cut Qty 249 381 of superhard (mg) plaster Cut surface 1.05 1.69 Ra(μm) Cut face ◯ X finish Stacking ◯ ◯ of dusts
For the Tables including Table I, II and III, the marks “◯” and “X” means as follows
Mark ◯: Satisfactory results obtained.
Mark X: Unsatisfactory results obtained.
[0000]
TABLE II
Emb. 2
Com. 2
Com. 3
Form of bar
bullet
bullet
bullet
Type of blade
leftward
leftward
rightward
twisted
twisted
twisted
plane cut
plane cut
plane cut
Number of blades
8 pcs
4 pcs
10 pcs
At the time
Cut Qty
289
320
191
of superhard
(mg)
plaster
Cut surface
1.00
2.03
1.85
cutting
Ra(μm)
Cut face
◯
X
X
finish
Stacking
◯
◯
X
of dusts
[0033] On checking the above Table I and Table II, we should like to explain the results of the same. With regard to Table I, our Embodiment 1 method is a little bit inferior to the Comparison test 1 in the cut quantity, but the difference is very small and acceptable. The each cut quantity shows some difference in accordance with the number of blades, but Embodiment 1 is still satisfactory. The cut surface of Embodiment 1 is much better than Comparison Test 1, while the cut face finish is in Embodiment 1 is also better than Comparison Test 1. With regard to the stacking of dusts, both Embodiment and Comparison Test are all right.
[0034] With regard to our Embodiment 2, when we check and observe this Table 2 with comparison Test 2 and 3, we can obtain the satisfactory and similar results accordingly similar to our Table I. We also observe we can attain satisfactory condition for the stacking of the dusts even if the cutting is performed in the wet condition.
[0000]
TABLE III
Emb. 3
Com. 4
Com. 5
Type of blade
Leftward
Rightward
Rightward
twisted
twisted
twisted
plane cut
cross cut
plane cut
Number of Blades
6 pcs
12 pcs
12 pcs
At the time
Cut Qty
57
50
44
of acryl plate
(mg)
cutting
Cut surface
1.37
1.67
1.52
Ra(μm)
Cut face
◯
X
X
finish
Stacking
◯
X
X
of dusts
[0035] When we check and compare our Embodiment 3 with the comparison tests 4 and 5 in this Table III with the acryl plate cutting performance, we also find satisfactory results for all points. Now, under our deep study and observation for the three tables as represented and performed comparisons in our developed carbide bars with prior bars, we have obtained satisfactory results. We are now in a position to provide our developed carbide bar for the dental rotary instruments, whereas we may submit the fine machines, namely the carbide bar for the dental rotary instruments and by this machine submission, the field workers and also the patients can enjoy the same in good efficient manners and in good feeling in the dental world.
[0036] It is further understood by those skilled in the art that the foregoing description is preferred embodiment of the disclosed method and that various changes and modifications may be made in this invention without departing from the sprit and scope thereof.
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This invention discloses a carbide bar for a dental rotary instrument which eliminates defects of the prior art. In the prior art, blades of the carbide bar are twisting on to rightward from a bottom to a top portion and this twisting offers some inconvenience such as detaching connection between hand piece and the bar during rotation work and stacking of cutting dusts for ill efficiency. This invention has now developed a new method for the blades, which should be twisted leftward from the bottom to the top to clear the submitted inconvenience.
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This is a continuation of application Ser. No. 686,713, filed May 17, 1976 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is generally related to nozzles and more specifically to high pressure nozzles for producing at least two distinct flow patterns.
2. Description of the Prior Art
High pressure nozzles are well knwon in the art and the concept of a high pressure nozzle having a safe and effective indexing means to produce at least two different spray patterns are also known in the art. However, most of these types of prior art devices are very bulky or have features which make them hazardous to use or difficult to adjust when under fluid pressure in excess of 500 psi.
The present invention provides a small, compact nozzle which, by partial rotation of the cap, changes the nozzle flow from a high pressure central jet to a lower pressure coaxial spray. Typically, a constant volume pump is used to supply the fluid to operate these high pressure nozzles.
SUMMARY OF THE INVENTION
Briefly, the present invention comprises an improvement to high/low pressure nozzles in which a high pressure stream of fluid can be converted to a lower pressure coaxial stream of fluid by rotating the cap of the nozzle to thereby produce a secondary stream of fluid which is coaxial with the central stream.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cross sectional view of my nozzle;
FIG. 2 is an end view of the nozzle insert located in my nozzle;
FIG. 3 is a side view of FIG. 2;
FIG. 4 is a front view of the secondary fluid supply members;
FIG. 5 is a side view of the rear portion of my nozzle;
FIG. 6 is a side view of the shield;
FIG. 7 is a side view of the body of my nozzle; and
FIG. 8 is a side view of a driver for my nozzle.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, FIG. 1 shows a cutaway view of my nozzle which is designated by reference numeral 10. Nozzle 10 comprises a first body member 12 and a second rotatable body member or cap 13 which extends over a portion of body member 12. Body member 12 and body member 13 coact to define an annular fluid chamber 25. Body member 12 is adapted to be connected to a source of high pressure fluid and contains a fluid flow passage 20 for receiving the high pressure fluid and a set of openings 19 which are in fluid communication with an annular chamber 25. Body member 12 contains a central opening 27 having a nozzle insert 30 located therein. Nozzle insert 30 has been made a separate portion from body member 12, but in an alternate embodiment, could be made from the same material as body member 12. Typically, nozzle insert 30 may be press-fit or threaded into body member 12 so that it is securely attached thereto.
Body member 12 is held in contact with body member 13 through a set of male threads 17 which are located in body member 12 and a set of female threads 18 which are located in body member 13. An annular recess 15 located around and in body member 12 contains an O ring 16 for sealing the high pressure fluid within the nozzle and preventing the flow of fluid between the two members.
Nozzle 30 contains an axial or central opening 31, a tapered portion 33 with a fan-type axial opening 32. However, a circular or other shaped opening could also be used. A circular ridge 34 is located on the outer portion of the nozzle and deflects the fluid stream that emanates from annular chamber 25. Located downstream from nozzle insert 30 is a diverging section 24. The diverging section 24 is located within rotatable member 13. Located on the outside of body member 13 and extending partially inside to form a continuous surface with diverging section 24 is a safety shield 14. Typically, safety shield 14 is made from a bright orange, polymer plastic to warn people of the danger of the high pressure fluid.
Circular ridge 34 protects sufficiently so as to deflect the fluid outward from the central flow of fluid but not so great so as to deflect the fluid into the diverging section 24.
Referring to other Figs., the specific details of the nozzle are shown more explicitly. FIG. 4 shows an end view of body member 12 showing the four openings 19 for passage of fluid into chamber 25 as well as a central opening 27 for which nozzle insert 30 is located therein.
In the operation of the nozzle shown, it is desired to have two different streams of fluid to a first central high pressure stream or jet and a second lower pressure coaxial stream of fluid. It should be pointed out that while the two streams are referred to as lower pressure, the pressure of the fluid stream is still within a range that could cause harm to an operator if a portion of the operator's skin should come in contact with the high pressure fluid.
The first high pressure fluid stream is obtained when member 13 is rotated so that the surface 21 (FIG. 1) is in contact with surface 22 (FIGS. 1 and 3). With surfaces 21 and 22 in contact, fluid is trapped in chamber 25 and only a central stream of fluid issues from nozzle insert 30. However, once surface 21 and surface 22 are separated by rotating member 13, with respect to member 12, fluid discharges between surface 21 and surface 22. Therefore, besides the central stream of fluid emanating through nozzle opening 32, there is a second outer or coaxial stream of fluid.
In operation of the nozzle, the fluid flows along surface 22 and deflects off ridge 34. However, as mentioned, the deflection is such that the fluid is not deflected into the diverging walls but is generally deflected at an angle which is less than the angle of deflection of diverging section 24. This is accomplished by having the angle of ridge 34 parallel to the angle of wall 24 or having the angle of the ridge diverge with respect to the angle of diverging wall 24. When the fluid issues from both the annular chamber 25 and the inner nozzle opening 32, one has a coaxial fluid flow at a lower pressure if the upstream openings or restrictions are designed appropriately. That is, the pressure of the stream is reduced if the upstream area or restriction (not shown) is only slightly larger than the combined area of the central opening and the annular opening. With this type of restriction or area relationship, the nozzle can be connected to aspirate a second fluid, such as soap, into the stream.
In the preferred use of my nozzle, the fluid is supplied by a constant volume pump. With a constant volume supply, the smaller the opening in the nozzle, the higher velocity of the stream and, conversely, the larger the nozzle opening, the slower the velocity of the fluid emanating from the nozzle. Accordingly, with all the fluid discharging through nozzle insert 30, one has a high velocity stream of fluid. However, when the area for the same amount of fluid to discharge through is increased, the velocity correspondingly decreases.
Typically, to aspirate a second fluid such as soap, the unit would operate as follows: the high pressure source would be connected to direct fluid through central nozzle 30. A second source of fluid which is not under pressure, would be connected to the line running between the first high pressure source and nozzle 30. The positive pressure associated with high pressure fluid would prevent a second solution from being drawn into the nozzle. However, as the flow velocity increases, the pressure decreases. Under proper conditions, a venturi effect is produced, i.e., a negative pressure or vacuum is produced which will suck the second solution through the nozzle. In this case, the soap will be sucked into the stream to provide a flow of soapy water. The venturi effect and aspirators are well known in the art; therefore, no further description of its operation will be supplied.
Referring to FIG. 8, reference numeral 40 identifies a driver that fastens over and around member 13. Driver 40 comprises an elongated hexagonal section having a pair of set screws 42 located therein. Set screws 42 lock driver 40 to member 13 by setting in an annular groove 44.
The purpose of driver 40 is two-fold, namely, to provide a gripping region so the user can turn body 13 with respect to pipe 41 and member 12 and to also provide a stop to prevent member 13 from accidentally being turned too far; that is, to prevent member 13 from being accidentally removed when the unit is under high pressure.
Referring again to FIG. 8, reference numeral 45 designates a surface on driver 40 which will abutt against end surface 47 if driver 40 is turned too far, thus preventing accidental unscrewing of member 13 from member 12; that is, rotation of driver 40 and member 13 stops when surface 45 contacts non-rotating surface 47.
A further feature of the present invention is that when the invention is used with a constant volume pump, one can produce a continuously variable flow pattern intermediate to the two extreme positions. That is, the nozzle has a proportional control because the area openings are variable. Thus, one can vary the rinse pattern and one can also vary the amount of soap or detergent in the fluid stream by turning nozzle 13 which will correspondingly increase or decrease the pressure to the source of aspirating fluid which, in the preferred embodiment, is soap. For example, as the suction pressure increases, one draws more soap into the stream; conversely, if the suction pressure decreases, one draws less soap into the stream. Therefore, the present invention provides for both a variable supply of soap and also a variable rinse pattern in the same nozzle and with a single control.
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A high pressure spray nozzle is provided having a central stream of fluid that can be changed to a coaxial flow of fluid by rotation of the housing cap to thereby produce an outer stream of fluid which is a coaxial to the central stream of fluid.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a geared pump for conveying fluids lacking or having insufficient lubricating ability, the pump including at least one connection for suction of the fluids and at least one connection for expulsion of the fluids, ducts and interstices joining the connection for the suction of the fluids and the connection for the expulsion of the fluids, and a conveying device for the fluids that is disposed in one of the interstices and includes an operating chamber in which two gearwheels rotate, the gearwheels mesh with each other while generating conveying spaces and reducing the conveying spaces again down to a minimum value, at least one duct on the suction side opens into the suction side of the operating chamber and at least one duct expels the fluids issuing from the pressure side of the operating chamber, and the meshing gearwheels are formed of a material from the group consisting of nonferrous metal, steel, special steel, industrial ceramics, metals and metal alloys produced by powder metallurgy, thermosetting and thermoplastic synthetic materials, thermosetting and thermoplastic synthetic materials containing fillers and synthetically produced carbon.
Geared pumps with an internal gear tooth system and those with an external gear tooth system are used in technology to a considerable extent for hydraulic power transmission in the pressure range of about 10 to 250 bar. They are used in the pressure range of about 2 to 10 bar for pure conveying tasks for the conveying of lubricating fluids such as oils of all kinds or of diesel fuel. When conveying fluids which lubricate badly or not at all, for example water, low-boiling hydrocarbons, in particular gasoline or kerosene, or liquids formed of solutions or mixtures, with the use of geared pumps, problems occur even after a short time at low output-side fluid pressures of about 2 to 10 bar. The friction becomes too high and the pumps fail due to erosion and/or corrosion. Problems of that kind also lead to the failure of the pumps in operating fields where temporary dry operation or periodically interrupted lubricating films have to be used.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a geared pump, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type, and which is suitable for conveying fluids that lubricate badly or not at all or run in a trouble-free manner under conditions in which dry operation occurs temporarily or a lubricating film periodically breaks down.
With the foregoing and other objects in view there is provided, in accordance with the invention, a geared pump for conveying fluids lacking or having insufficient lubricating ability, the pump comprising at least one connection for suction of fluids and at least one connection for expulsion of the fluids; ducts and interstices joining the connection for the suction of the fluids and the connection for the expulsion of the fluids; and a fluid conveying device disposed in one of the interstices and including an operating chamber having suction and expulsion sides, two gearwheels rotating in the operating chamber and mutually meshing for generating conveying spaces and reducing the conveying spaces again to a minimum value, and a housing of the operating chamber surrounding the gearwheels; at least one of the ducts for the suction of the fluids opening into the suction side of the operating chamber, and at least one of the ducts for the expulsion of the fluids opening from the pressure side of the operating chamber; the mutually meshing gearwheels formed of a material from the group consisting of nonferrous metal, steel, special steel, industrial ceramics, metals and metal alloys produced by powder metallurgy, thermosetting and thermoplastic synthetic materials, thermosetting and thermoplastic synthetic materials containing fillers and synthetically produced carbon; and the housing of the operating chamber formed of a synthetically produced material with a matrix formed of a carbonized, non-graphitized carbon and a filler bonded into the matrix, the filler formed of 35 to 97% by weight graphite, 0 to 62% by weight non-graphitized petroleum pitch coke or coal-tar pitch coke and 3 to 20% by weight mineral constituents.
Parts formed of carbon have been used for a long time in mechanical engineering, for example as sliding rings, sealing rings, sliding supports, gliding rings or shut-off valves (see, for example, articles by L. Jorres, in the publication entitled "Ingenieur-Werkstoffe 1" [Engineering Materials 1] No. 11/12 (1989) and "Ingenieur-Werkstoffe 2" [Engineering Materials 2], No. 1/2 (1990)). It is noted that if particular reference is not made to corresponding differences in material qualities, graphite is also to be included in the term carbon when used below. However, the use of such parts formed of carbon is not without problems because the use of carbon parts always depends on the selection of a material pairing which is suitable for the prevailing operating conditions. Parts formed of carbon which have proven to be good when operating with a certain countercurrent material in a certain operating medium can prove to be unsuitable when operating with another countercurrent material or in another operating medium. It is therefore extremely important to find suitable carbon qualities for the respective applications and there is no general technical rule for achieving that object. The mutual suitability of sliding or supporting materials that are paired with each other also depends on the machines and their structural conditions in which and with which the materials must run against each other. Therefore, for example, sliding ring seals are known in which one or both sealing rings is formed of a carbon material (German Utility Model G 94 19 961.2), or shut-off valves in dry-running rotation compressors or in wet-running wing cell pumps are also used if liquids with lubricating properties which are not very distinctive have to be conveyed. At first sight, such prior art could allow the conclusion to be drawn that the use of carbon parts in geared pumps, for which protection is requested in the instant patent application, is obvious to the expert. However, that is not the case. Despite the presence of a need therefor, up to the time of the invention there were no geared pumps which were suitable for conveying fluids with no or insufficient lubricating ability because, heretofore, appropriate attempts to convey such media with geared pumps had failed due to early failure of the pumps caused by erosion and/or corrosion. Many experts are even of the opinion that the conveying of fluids of the aforementioned type with geared pumps cannot be controlled technically. It is therefore a result of inventive activity if geared pumps are provided which are suitable for conveying such fluids that lubricate badly or not at all, in continuous operation.
An essential feature of the pumps is that the housing of the operating chamber of the pump, which housing surrounds the conveying gearwheels, is formed of a synthetically produced carbon material which is fluid-tight. In such a pump both gearwheels located in the conveying chamber are mounted axially in a sliding manner on the walls of the conveying chamber which surround them on both sides and which is formed of the carbon material. In the case of an externally geared pump the two sides of the operating chamber are additionally constructed as supporting blocks for the axles of the gearwheels, so that the axles of the gearwheels are also mounted in fittingly shaped supporting bushes of carbon. Furthermore, in the case of an internally geared pump the external gearwheel having the internal gear tooth system is additionally mounted in a sliding manner along its entire periphery in the radial direction on the inner jacket of the conveying or operating chamber, which inner jacket likewise is formed of the carbon material, and in the case of an externally geared pump the radially external tooth surfaces slide in a sealing manner along the inner jacket of the conveying chamber.
In contrast with the heretofore-existing applications of machine elements being formed of carbon materials in the field of dynamic seals and sliding elements, where the parts being formed of the carbon materials always only had one stress direction and one sliding surface, with the pumps in accordance with the invention several supporting configurations are united which in part differ substantially with respect to their loads and the demands made of their sliding properties. Within the meaning of the invention, a single material pairing must correspond to this particular combination of demands. In addition, during the operation of the pumps in accordance with the invention, operational states can also occur where the fluid film between the elements which slide against each other breaks down, for example when the pump starts or when the conveying current is chopped. The pumps in accordance with the invention are also suitable for conditions where a brief dry operation or operation with mixed friction is required.
The housing of the operating chamber is preferably formed of a carbon material with a matrix of a carbon which is carbonized but not heated to graphitization temperature. This matrix is obtained for the production of the carbon material by coking or carbonizing the bonding agent of an initial product body, wherein the bonding agent contains coking substances. The initial product body is formed of the binder and certain fillers. When this body is carbonized, work must be carried out below a temperature where graphitization processes begin. A final temperature of 900 to 1000° C. is preferably used. The coking or carbonizing is carried out in the manner known to the expert in the field of carbon technology with the exclusion of substances which have an oxidizing effect. The bonding agent used is either a coal-tar pitch, a petroleum pitch or a mixture of one of the aforementioned pitch types and a synthetic resin. When selecting the bonding agent it must be observed that after the carbonizing the bonding agent has a coke yield of at least 50%, preferably of more than 60% and in particular preferably of more than 65% by weight (determination according to DIN 51905). The binder is mixed with the filler in the manufacture of the carbon material. In this respect, the binder can be mixed with the filler both in liquid form and in finely powdered form. Mixing in a finely powdered form is used particularly when pitches with high softening points are processed. However, it is also possible to mix the binder in liquid form with the filler at temperatures above its softening point. After the mixing, shaped carbon bodies can be pressed from mixtures produced according to both mixing methods. The preferred procedure in working with pitches is the introduction and mixing-in of the bonding agent in powdered form and the subsequent pressing of shaped bodies from the mixture of filler powder and binder powder which is obtained. If a mixing of a binder in liquid form with the filler has been selected, it is advantageous to grind the obtained mixture of binder and filler before pressing, to form shaped bodies into a fine granulation and then to press this ground material to form shaped bodies. The pressing preferably takes place in die presses or isostatic presses. All of the so-called green shaped bodies produced according to one of the aforementioned methods are then supplied to the carbonizing process.
The filler content in the initial product and in the carbon material is formed of 35 to 97% by weight graphite, 0 to 62% by weight non-graphitized petroleum pitch coke or coal-tar pitch coke and 3 to 20% by weight mineral constituents which influence the tribological properties of the material.
In accordance with another feature of the invention, the graphitic part of the filler can be natural graphite, Kish graphite, electrographite, i.e. graphite produced by a synthetic, electrothermal method, or even graphitized coke, or it can be formed of a mixture of one or more of the aforementioned substances. In the electrothermal production of graphite, the material must be exposed to a temperature of at least 1800° C., preferably of more than 2400° C. up to 3000° C. during the graphitization process, which must likewise be carried out with the exclusion of media having an oxidizing effect.
The second part of the filler is formed of non-graphitized petroleum pitch coke or coal-tar pitch coke. These cokes already belong to the relatively hard part of the carbon material which has less lubricating ability, but which increases the capacity for resistance to abrasion.
In accordance with a further feature of the invention, the third-part of the filler is formed by hard materials which preferably are formed of or contain oxides, carbides, nitrides, borides or silicates.
In accordance with an added feature of the invention, silicon dioxide, silicon carbide, aluminum oxide, boron carbide, silicon nitride or feldspar are particularly preferred. These substances have the task of further increasing the resistance of the carbon material to abrasion and, during operation, of keeping the counter-running surfaces clean through the use of a light abrasive action.
Before being brought together with the bonding agent, each of the constituents which later form the filler is ground to the fineness of flour. The ground material produced in this respect preferably has sieving values which lie in the region of the combination of d 50 =15 μm and d 95 =55 μm. Grains with a size greater than 400 μm are sieved out.
After firing, the shaped bodies which are produced are still porous because of the loss of pyrolysis products of the binder content. They must also be made fluid-tight for use as structural material in pumps.
In accordance with an additional feature of the invention, this takes place by filling the pore system of the bodies to which liquid has access with a liquid impregnating medium that either solidifies or is hardened after the impregnation.
Thermosetting and thermoplastic synthetic resins are used as the least expensive impregnating medium which is also preferred in this case.
In accordance with yet another feature of the invention, resins from the group formed of phenolic resins, in particular of the resol type, furan resins or polyester resins, perfluorinated hydrocarbon resins or polyamide resins are particularly preferred in this case. When using synthetic resins as impregnating media it must be observed that the usage temperature of the pump is limited by the actual thermal loading capacity of the impregnating medium. Carbon parts for pumps which are to be operated at very high temperatures are impregnated with liquid metals or their alloys, for example copper and copper alloys or antimony and antimony alloys. In order to provide for the greatest demands, the carbon parts can also be made fluid-tight by a so-called Chemical Vapor Impregnation (CVI) that is known to the expert. In this process, gaseous substances are introduced at high temperatures into the pore system of the carbon parts. Those substances form carbon or other hard materials upon thermal decomposition. Along with this thermal decomposition, at least the pore openings are completely filled with carbon or with one of the hard materials, which effects a sealing of the body.
The gearwheels which mesh with each other in the conveying chamber or the operating area of the pump can be formed of different materials according to the structure, mechanical or thermal loading or the medium to be conveyed. In order to convey water, special steel or a nonferrous metal is preferably used, with the parts preferably having been made by a powder-metallurgical method. However, parts made from complete metal pieces or complete pieces of a metal alloy can also be usedp although their production is more costly and, in practice, they no longer have any pores. The parts can be formed of thermosetting or thermoplastic synthetic materials, for example hardened phenolic resins, furan resins, or polyester resins, or polyamides or polyimides, in the case of demands which are not too high with respect to the resistance to corrosion in the region of comparatively low temperatures. In order to improve the mechanical and thermal properties, these thermosetting resins and thermoplastic materials are frequently used, to advantage, in forms equipped with powdery and/or fibrous fillers. When selecting the fillers the expert refers to known specialist knowledge. Gearwheels made of industrial ceramics, for example porcelain or silicon carbide or, in particular, made of synthetically produced carbon grades suitable for use as sliding ring material or supporting material, are used for applications at higher temperatures and/or under operating conditions where there is more corrosion. In order to improve their tribological properties, the carbon bodies can be provided with an impregnation or coating of a hard material, for example SiC, TiC, WC, TiB 2 , Si 3 N 4 or BC according to one of the methods known from the prior art, for example CVI, CVD (Chemical Vapor Deposition) or CVR (Chemical Vapor Reaction). The expert selects the material which is suitable according to the given technical limiting conditions with the aid of tests that can be carried out easily.
If the pump housing which is formed of the carbon material and which limits the operating chamber of the pump, has a correspondingly stable, i.e. thick-walled construction, an additional cover supporting and protecting this housing is not necessary. However, the housing formed of the carbon material is usually surrounded by a cover which supports it mechanically, absorbs internal pressures and protects it against mechanical damage such as knocks or impacts. This cover can be formed of a metallic material, a synthetic material or a material reinforced with fibers. It is constructed in accordance with known technological regulations.
In accordance with yet a further feature of the invention, one of the preferred types of structure of the pumps in accordance with the invention is that of internally geared pumps where two gearwheels are disposed one inside the other in the operating chamber of the pump, the internal gearwheel is driven, and the gearwheels rotate in such a way that when the external gear tooth system of the internal gearwheel meshes with the teeth located on the inside of the external, annular gearwheel, on the suction side of the pump, new conveying areas are constantly created, into which the fluids to be conveyed penetrate, and on the pressure side of the pump these conveying areas are continuously reduced again down to a minimum value, resulting in the fluids located in the conveying areas being expelled into the pressure duct. A condition for the operability of such a pump is that the internal gearwheel has a smaller number of teeth than the external gearwheel.
In accordance with yet an added feature of the invention, the housing of the operating chamber of the pump is formed of two parts which are connected to each other in a fluid-tight manner. The first part has the form of a cup with a base and a cylindrical jacket-shaped wall. The second part covers the interior of the first part completely, having a fluid-tight connection with the upper part of the cylindrical jacket-shaped wall of the first part. The second part preferably lies on the upper, free edge of the wall of the first part in a fluid-tight manner. Upon operation of the pump as usual, one must imagine that the cup provided with the cover lies on its wall surface. The gearwheels of the conveying device are mounted within the chamber which is formed by the cup and the cover, with all of the walls of the carbon material which limit the chamber on the inside simultaneously representing the supports. In the process, the following different supporting configurations result. On one hand, the surface area of the external gearwheel which is on the outside when seen in the radial direction is mounted on the inner wall of the cylindrical jacket-shaped wall of the cup and is rolled away there when the pump is operated, and on the other hand both sides of the two gearwheels are mounted in a sliding and sealing manner at the side walls of the operating chamber, that is to say on one hand on the base of the cup and on the other hand at the inside of the cover. The suction-side and pressure-side recesses in the side walls of the operating chamber, which recesses are necessary for the operation of the pump and are coordinated with the conveying areas in the gearwheels of the pump and are connected to the corresponding suction and pressure ducts, can be disposed in one of the two lateral parts which limit the operating chamber (base of the cup or cover). The lateral part in which these recesses with their duct connections are located then has to be constructed to be so thick that there is room therein for these functional elements of the pump. These recesses are preferably accommodated in the lateral part of the operating area which is directed away from the driving mechanism of the pump. However, it is also possible to place these functional elements on the driving mechanism side or to place the recesses on both sides of the operating chamber.
In accordance with yet an additional feature of the invention, the operating chamber housing is formed of carbon and is formed of three parts, namely a part which completely surrounds the operating chamber in the radial direction and which is hollow-cylindrical on its inside, and two plates or blocks which completely cover two open sides of this part that is hollow-cylindrical on the inside, the plates or blocks forming a seal with the ends of these two sides in a fluid-tight manner. The supporting configuration of the gearwheels and the driving mechanism of the internal gearwheel corresponds to that of a pump with a two-part housing, with the difference being that the support disposed in the base of the cup in the two-part structure is now replaced by the support in a block-shaped or plate-shaped side wall. The method by which the pump or the supporting configuration of the gearwheels functions is not changed thereby. As far as the configuration of the suction-side and the pressure-side recesses and the fluid ducts connected to them are concerned, the structural features described with regard to the previously described two-part form of the housing of the operating chamber are also possible in this case. In addition, with the three-part embodiment, parts of the suction-side and the pressure-side ducts can also be disposed in the wall of the part which is hollow-cylindrical on the inside.
In accordance with again another feature of the invention, the inner gearwheel of the internally geared pump preferably has a shaft disposed centrally on one of its flat sides, the shaft is sealed on this side, is led through the housing of the operating chamber to the outside and is connected there to a driving mechanism. However, for reasons of quiet running it can be necessary to equip the inner gearwheel with shafts issuing from both flat sides, wherein one shaft of which is led in a sealed manner through the housing of the operating chamber and is connected to a driving mechanism, and the other shaft is mounted in the other side wall of the housing of the operating chamber.
In accordance with again a further feature of the invention, in order to provide an improved control of the gearwheels of an internally geared pump, one or both of the flat sides of the driven gearwheel has a cylindrical projection thereon disposed concentrically about the shaft of the gearwheel and firmly connected to the gearwheel, and the projection fits into a complementary hollow-cylindrical recess in the adjacent inner wall surface of the operating chamber and is rotatably mounted there with little tolerance. If the shaft only extends to one side of the gearwheel, then such cylindrical projections with their complementary supports can nevertheless be located on the two sides of the gearwheel in the adjacent side wall of the operating chamber. The cylindrical projection can also be constructed in the form of a cylindrical jacket disposed concentrically about the shaft, wherein the radially outer surface area of the cylinder jacket is the running surface which slides in the support. For reasons of cost, the structure is preferably used with an additional supporting configuration which is only disposed on one of the flat sides.
In accordance with again an added feature of the invention, the geared pump is an externally geared pump, two gearwheels are each provided with a respective external gear tooth system and are disposed next to each other in an operating chamber, and the teeth of these gearwheels mesh with each other in sealing the suction chamber from the pressure chamber of the pump, with the fluid which is in the intermediate teeth areas of the teeth that are not meshed with each other being conveyed from the suction side to the pressure side and being expelled on the pressure side by the pressure which is built up by the conveying.
Additionally, according to the invention, with this type of pump, at least the walls of the operating chamber are formed of a carbon material, and the gearwheels bear at several locations on and in the walls which limit the operating chamber. Firstly, the sides of the gearwheels disposed in the axial direction slide in a sealing manner on the side walls of the operating chamber. Secondly, the external radial sides of the teeth of the gearwheels slide along their entire width in a sealing manner on the internal wall of the cover part which limits the operating area in the radial direction, and thirdly, the shafts of the gearwheels are mounted in supporting blocks of carbon which are located in the lateral parts of carbon material that form the lateral walls of the operating chamber.
In accordance with a concomitant feature of the invention, the housing of the operating chamber of an externally geared pump of this kind is preferably formed of three parts. Firstly, it includes two supporting blocks which contain the supports for the shafts of the gearwheels and which at the same time are used as lateral limiters of the operating chamber of the pump on both sides which are disposed in the axial direction with respect to the gearwheels. Secondly, it includes a jacket-shaped cover part which is connected to the two lateral blocks or plates in a fluid-tight manner, is compact in itself and on its inside follows the radial outer contour of the gearwheels, contains the suction chamber and the pressure chamber and is provided with openings for the fluid inlet and the fluid outlet.
The pumps according to the invention are preferably used to convey liquids of the previously mentioned type with pressures on the pressure side of 2 bar and more, and with 3 to 8 bar being preferred in particular.
The production of a carbon material for a housing of the operating chamber of internally geared pumps is described by way of example in the following: 78% by weight of a macrocrystalline natural graphite which can be purchased, 14% by weight of a graphitized coal-tar pitch coke and 8% by weight of a mixture of 60 parts by weight of quartz powder and 40 parts by weight of feldspar, all of which had been ground to a grain fineness of d 50 =15 μm, d 95 =55 μm and with which a grain content of more than 350 μm had been sieved out, were mixed intensively in a dry state. Then 30 parts by weight of a finely powdered coal-tar pitch were added to 70 parts by weight of this mixture, wherein the coal-tar pitch had a softening point according to DIN 51920 of 110° C. and a coke residue according to DIN 51905 of 62%. After that, fillers and pitch binders were homogenously mixed at room temperature in a rapid mixer. After discharge from the mixer, the finely powdered mixture was poured into the compression mold of a die press and pressed there without external heating under a pressure of 200 MPa to form a shaped body. If the somewhat difficult handling with the finely powdered mixture is to be avoided, heating to a product temperature of about 150° C. with further mixing can also take place after the thorough mixing of the powdery filler with the powdery binder. After the discharge from the mixer and the cooling of the mixture it must then be broken up or ground to a fineness with a maximum grain size of 1 mm. The bulk ground material which is obtained in this way and which can be handled more easily is then pressed to form shaped bodies, as was previously described. The shaped bodies were then heated in an annular furnace with a burning regime for fine-grained carbon material up to a final temperature of 1200° C., with the binder being carbonized and a porous, firm carbon body being obtained. This body was then impregnated with an impregnating resin of the phenol resol type in accordance with the vacuum pressure method, in order to produce fluid-tightness. The parts that are necessary for the housing of a geared pump were then produced by machining from the impregnated blank being formed of the carbon material. The fluid-tight carbon material had the following physical data:
______________________________________ hardness HRB 10/100 (DIN 51917) 100bulk density (DIN IEC 413) 1.83 g/cm.sup.3bending strength (DIN 51902) 55 MPaE-modulus (DIN 51915) 20 GPa______________________________________
An internally geared pump in accordance with the invention, having gearwheels which were formed of powder-metallurgically produced special steel (Material No. Sint C 40, DIN 30910), in which the walls of the operating chamber were formed of a carbon material, and the production of which has been described in Example 1, was operated in continuous operation without any trouble with water as the medium to be conveyed at a speed of 3000/min and a conveying capacity of 6 l/min for 30 days. After this extended time test none of the parts located in the operating chamber showed any appearances of erosion or corrosion. The sliding and supporting surfaces were in an excellent state.
Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a geared pump for conveying fluids, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic, cross-sectional view through an operating chamber of an internally geared pump;
FIG. 2 is a cross-sectional view through a block of a carbon material which contains one side wall of an operating chamber of an internally geared pump, which is taken along a line II--II of FIG. 3, in the direction of the arrows;
FIGS. 3, 3a and 3b are cross-sectional views through an operating chamber of an internally geared pump parallel to an axle of an internal gearwheel;
FIG. 4 is a cross-sectional view through an externally geared pump parallel to axles of gearwheels; and
FIG. 5 is a cross-sectional view through an externally geared pump at right angles to axles of gearwheels.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a cross section through an internally geared pump. The pump has a suction connection indicated by an arrow pointing downward at the top and an expulsion connection indicated by an arrow pointing downward at the bottom. As seen from the outside to the inside, the pump includes a cast metal housing 1 that surrounds a jacket of a carbon housing 2 of an operating chamber 3 in a protective and supporting manner. The operating chamber 3 is then followed by a supporting zone 4, which is represented in this case as a gap that is too large, between the housing formed of the carbon material 2 and a radially outer running surface 5 of an external gearwheel 6. The external gearwheel 6 has an internal gear tooth system 7 which has one more tooth than an external gear tooth system 8 of an internal gearwheel 9 which runs therein. On one hand, the internal gearwheel 9 is driven by way of a shaft 10 which is disposed eccentrically in the pump housing. On the other hand, the external gearwheel 6 is disposed centrally in the operating chamber 3. Upon rotation, the teeth 8 of the internal gearwheel 9 engage depressions of the internal gear tooth system 7 of the external gearwheel 6 completely on one side, then they free interstices 11 to an increasing extent on a suction side of the pump because of a gear difference in the two gear tooth systems 7, 8 that engage with each other. Liquid to be conveyed can flow from recesses 12 shown in FIG. 2 into the interstices. The recesses are located on a suction side of the pump, are called "suction recesses" in this case, are disposed in a side wall 13 of the operating chamber 3 which can be seen in FIG. 3 and are connected to a suction duct 16 of the pump seen in FIG. 2. The teeth 8 of the internal gearwheel 9 close these interstices 11 on the subsequent pressure side of the pump, while the liquid located in the interstices is expelled into recesses 14 which are called "pressure recesses" in this case, are connected to a pressure duct 15 seen in FIG. 2 and are disposed on the pressure side of the pump. On the side of the shaft 10, the internal gearwheel 9 has a concentric cylindrical projection 17 which is mounted in an additional support 18 shown in FIG. 3. The support is used to increase the quiet running of the pump.
FIG. 2 shows a cross section through a block formed of a carbon material which forms one of the lateral walls of the operating chamber 3. The block is again surrounded by a housing 1 of cast metal, into which the suction duct 16 and the pressure duct 15 of the pump are also formed. The suction duct 16 is connected from the suction connection to the recess 12 which is the so-called "suction recess" in the side wall of the operating chamber 3 and the pressure duct 15 is connected from the expulsion connection to the recess 14 which is the so-called "pressure recess" in the side wall of the operating chamber 3. The method in which the pump functions can be followed easily in combination with the description given in FIG. 1. The gearwheels 6 and 9 rotating in the operating chamber 3 are mounted in a sliding manner on the surface of the block of carbon which forms the side wall and which is illustrated herein, and the outer gearwheel 6, as shown in FIG. 1, slides additionally with its outer running surface 5 on the internal wall of the jacket of the carbon housing 2 of the operating chamber 3 as an additional support.
FIG. 3 shows a cross section through the operating chamber 3 of an internally geared pump, parallel to the direction of the shaft 10 of the internal gearwheel 9. A first part of the housing is a carbon housing 19 which is cup-shaped in this case and which on one hand supports the radial support 4 for the external gearwheel 6 on the inside of its cylindrical jacket-shaped internal wall 20 and on which the two lateral surfaces of the gearwheels 6 and 9 on an internal surface of a base 21 are mounted, is also surrounded in this case by a housing 1 of cast metal. The internal gearwheel 9 has a cylindrical projection 17 disposed concentrically about its shaft 10, with a radial supporting surface 22 which is fitted into a complementary opposed supporting surface 23 located in the base of the cup-shaped part of the housing 19, and which runs in the housing. The side wall 13 of the operating chamber 3 is a second plate or blocked-shaped part of the housing which covers the first part 19.
The embodiment of FIG. 3a differs from that of FIG. 3 in that the housing of the operating chamber 3 is formed of three parts, namely one part which completely surrounds the operating chamber 3 in the radial direction and which is hollow cylindrical on its inside and two plate or block-shaped parts which completely cover the two open sides of this part that is hollow cylindrical on the inside. The plates or blocks form a seal with the ends of these two open sides in a fluid tight manner.
In the embodiment of FIG. 3b, the internal gearwheel 9 has two cylindrical projections 17 disposed concentrically about the shaft 10 which passes through them. These projections 17 fit into complementary hollow cylindrical recesses in the respective adjacent inner wall surface of the operating chamber and are rotatably mounted there with little tolerances. The shaft 10 protrudes from both flat sides of the inner gear wheel 9 and its bearings are disposed in recesses in the side walls of the housing of the operating chamber.
FIGS. 4 and 5 show two cross sections through an externally geared pump, wherein the one shown in FIG. 4 is parallel to shafts 24, 24' of gearwheels 25, 25' and the other shown in FIG. 5 is at right angles to the shafts 24, 24' of the gearwheels 25, 25'. As can be seen in FIG. 5, the liquid to be conveyed enters a suction chamber 26 of the pump driven by one of the shafts 24, 24' of the gearwheels 25, 25', is enclosed in intermediate teeth areas 27 of the gearwheels 25, 25' rotating in opposite directions, is conveyed into a pressure chamber 28 of the pump and from there is expelled from the pump. The suction chamber 26 and the pressure chamber 28 of the pump are separated from each other by the tightly meshing teeth of the gearwheels 25, 25'. In this case as well, the operating chamber 3 of the pump is surrounded by a housing of a carbon material 2 which abuts an outer periphery 29 and lateral surfaces 30 of the gearwheels 25, 25' in a sliding and sealing manner and forms various supports. The various carbon parts which form the walls of the operating chamber 3 and their function can be recognized clearly in FIG. 4. The side walls are formed by blocks 31 and 31' which at the same time contain supports 32, 32', 32", 32"' for the shafts 24, 24' of the gearwheels 25, 25'. The sides of the blocks 31, 31' facing the operating chamber 3 form sealing sliding supports for the lateral surfaces 30 of the gearwheels 25, 25'. In the circumferential direction the operating chamber 3 is completely enclosed by the carbon jacket 2 which abuts the outer periphery 29 of the gearwheels 25, 25' in a sealing and sliding manner along conveying zones formed by the intermediate teeth areas 27. This jacket also has openings for the suction duct 26 and the pressure duct 28 of the pump.
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An internally or externally geared pump for conveying fluids lacking or only having insufficient lubricating ability, includes gearwheels moving in an operating chamber of the pump, conveying fluids and being mounted completely in parts formed of a carbon material. Supports are formed from accurately worked lateral walls and a jacket of the operating chamber formed of the carbon material. The jacket surrounds the gearwheels in the radial direction and is likewise constructed as a support. Chambers on the suction side and on the pressure side for fluid supply and fluid removal, which are necessary for the operation of the pump, are molded into side walls of the operating chamber which is formed of carbon.
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SUMMARY OF THE INVENTION
In accordance with the present invention, the maneuvering device essentially comprises a shaft arranged on the drawbar of the trailer, the shaft being adjustable for height. At least one wheel is mounted at the end of the shaft with the axis of the wheel being perpendicular to the shaft. The present invention also includes at least one driving means for driving the wheel in rotation about its axis and means for swivelling the wheel.
In accordance with a first embodiment of the present invention, the driving means for driving the wheel comprises an electric or internal combustion motor and a speed reducer, both of which are mounted on the top free end of the shaft so as to ensure the transmission of the rotary movement to the wheel. In this first embodiment, the shaft consists of a hollow casing adjustable for height terminating at, for example, a simple rack and pinion assembly in which a pin is located which transmits the rotary movement of the driving means to at least one wheel.
Because of the height adjustability, the wheel may be raised or lowered in relation to the drawbar of the trailer depending upon whether the operator has hooked the trailer onto the towing vehicle; or whether the operator has the intention of moving it independently of the towing vehicle. In this embodiment, the wheel swivelling means comprises a handle or a manual steering wheel arranged, for example, on the casing of the driving motor.
In accordance with another embodiment of the present invention, the wheel driving means comprises an electric or an internal combustion motor and a speed reducer, both of which are mounted on the axis of the wheel. In this second embodiment, the shaft is adjustable for height and is able to slide in a sleeve integral with the drawbar of the trailer.
BACKGROUND OF THE INVENTION
This invention relates to a motorized device for aiding the maneuvering of trailers such as caravans, horse box or boat trailers and the like subsequent to detachment of the trailers from the towing vehicle.
Conventional trailers generally comprise a retractable device which aids in manual maneuvers after the trailers are detached from the towing vehicle. Such devices generally comprise a wheel mounted on a pivoting shaft or on a pivoting fork. However, it will be appreciated that as the weight and dimensions of a trailer becomes relatively large, it becomes difficult to steer the trailers by hand and to push them for the purpose of changing their position. This task becomes all the more arduous when the ground is uneven.
Accordingly it is an object of the present invention to provide a device for trailer maneuvering which particularly aids the maneuvering of trailers subsequent to their detachment from the towing vehicle.
It is another object of the present invention to provide a trailer maneuvering device which comprises at least one driving motor and which aids the operator in movements from place to place, without the operator having to exert considerable muscular effort.
Still another object of the present invention is to provide a simple maneuvering device of strong construction which is particulary well suited to the trailers on which it is mounted.
Preferably, the means for swivelling the wheel may comprise a motor which is integral with the sleeve; the movement of rotation being transmitted via a means of transmission and reduction to the shaft fitted with a means of longitudinal engagement. In this embodiment, a remote control enables the swivelling of the wheel and the turning thereof to be controlled in such a manner that the trailer may be easily steered.
Also in a preferred embodiment, at least one of the driving means comprises an additional power take-off which permits various accessories like a hydraulic pump, a winch or the like to be coupled thereto.
The above discussed and other features and advantages of the present invention will be appreciated and understood by those of ordinary skill in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, wherein like elements are numbered alike and the several Figures:
FIG. 1 is a perspective view of a first embodiment of a trailer maneuvering device of the present invention; and
FIG. 2 is a perspective view of a second embodiment of a trailer maneuvering device of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, a maneuvering device for trailers is shown in accordance with a first embodiment of the present invention. This maneuvering device comprises a hollow casing 1 mounted on the drawbar of a trailer (not shown) such as a caravan, boat trailer or the like. Hollow casing 1 is slidably received in a sleeve 3 which is integral with the drawbar (not shown) and which is adjusted for height by a conventional rack and pinion assembly 5 shown diagrammatically mounted on casing 1. The bottom end 7 of hollow casing 1 has two wheels 9 mounted on a common axis 11 substantially perpendicular to casing 1.
Driving means such as an internal combustion motor followed by a reducer, combined together in a casing 13, is arranged on the top of casing 1. The driving means transmits its turning movement to a pin 2 mounted inside hollow casing 1 and then, in accordance with suitable gearing, movement is transmitted to wheels 9.
The maneuvering device of the present invention further comprises means for swivelling wheels 9 in order to be able to steer the trailer in a desired direction. In the case of FIG. 1, this swivelling means is preferably composed of a handle 15 integral with casing 13 which transmits the pivoting movement exerted manually by the operator to the wheels 9.
Preferably, the maneuvering device of the present invention is also provided with a safety device which immediately stops the driving means as soon as the operator is no longer in a position to control the device. This safety device may be composed of a conventional declutching lever 17 which the operator must hold at the same time as the handle 15 in a known manner.
The maneuvering device of the present invention may also include an auxiliary power take-off 19 which may be engageable with the aid of a lever 21. Power take-off 19 permits various accessories to be coupled thereto. For example, such accessories may consist of a hydraulic pump to work a hydraulic installation, such as a tipping trailer; or a traction winch intended, for example, for boat trailers or trailers intended for vehicle recovery.
In the embodiment shown in FIG. 2, a shaft 1 is arranged in a slideable and adjustable manner in a sleeve 3 made integral with the drawbar 16 of a trailer. Preferably, height adjustment of shaft 1 is made with the aid of a lever 5 whose rotation enables a threaded rod 6 to mesh with an internal thread made in shaft 1.
The driving means 13 for the wheel 9 in rotation about its axis 11 is preferably mounted on the end of shaft 1; preferably substantially on the same axis 11 as that of wheel 9. It will be appreciated that the swivelling means for the wheel 9 may also comprise a handle of the abovementioned type. However, it may also comprise a motor 15, preferably an electric motor, followed by a speed reducer which is integral with sleeve 3 and which acts on a longitudinal key 31. Key 31 permits a reducing action over the whole length of shaft 1, that is if shaft 1 is adjusted for height. Of course, other means may also be provided such as a splined shaft together with a toothed belt for accomplishing this reduction in action.
This embodiment of FIG. 2 is particulary well suited for a remote control with the aid of a remote control board 33. An extremely simple maneuver is made by the operator on pressing the key according to the easily understood symbols. Thus as shown at 33 in FIG. 2, the control enables the machine to steer the trailer in every direction; forwards, backwards, to the right and to the left, without any effort on the part of the user. It will be appreciated that when the symbol keys "front" and "to the right" are pressed simultaneously, the two motors 13 and 15 are simultaneously actuated. As a result, motor 33 moves the trailer forward and the motor 15 makes the shaft 1 pivot to the right. An advantage of remote control unit 33 is that the user may control the maneuvers of all the positions while having complete visibility about the trailer. It will be further appreciated that the structural details of remote control unit 31 are well known; and that such units are commercially available.
In the event that the electric cable which connects remote control 31 to the machine becomes detached, a safety system is switched on, causing the machine to automatically stop.
The energy required for the operation of the present invention may be supplied by a 12 or 24 volt automobile type battery (not shown) which is located on the trailer and recharged, for example, by the alternator of the towing vehicle.
In an alternative embodiment, electric motor 13 may be replaced by an internal combustion engine of which a second power take-off has to be coupled to reducer 15, possibly with the aid of a flexible drive.
The maneuvering device of the present invention has many important features and advantages. For example, when guided by the driver, the present invention is able to push or pull the trailer in all directions without great effort on the part of the driver. In addition, the speed is advantageously adjusted to a value near that of walking pace.
It will be appreciated that other accessories may also be provided to the maneuvering device of the present invention such as a headlight 51 (see FIG. 1) or the like. Similarly, the present invention contemplates the use of any suitable and known method for fixing or attaching the maneuvering device of the present invention to the trailer drawbar.
While preferred embodiments have been shown and described, various 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 motorized device for aiding the maneuvering of trailers subsequent to detachment from the towing vehicle is presented which comprises a shaft attachable to the drawbar of the trailer and which is adjustable for height. At least one wheel is mounted at the end of the shaft with the axis of the wheel being perpendicular to the shaft. At least one driving device for driving the wheel in rotation about its axis and a swivelling device for swivelling the wheel are also provided.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the field of network communications, and in particular to a wireless device that facilitates Bluetooth connectivity between other devices.
[0003] 2. Description of Related Art
[0004] Bluetooth is a wireless network standard that provides for the establishment of wireless networks in an ad hoc manner. Each Bluetooth-enabled device is configured to broadcast a short-range signal; when a new device is within range of the device, an initiation protocol commences to establish a communication channel between the devices. A class 1 Bluetooth device has a nominal range of 100 meters; a class 2 device, 10 meters; and a class 3 device, less than 10 meters. Most Bluetooth devices are expected to be class 2 devices with range of 10 meters.
[0005] Bluetooth supports both secure and non-secure communications between devices. Each Bluetooth device is identifiable by a unique 48-bit address, and includes a 128-bit private authentication key, an 8-128 bit private encryption key, and a 128-bit random number generator. The initiation protocol uses the device's unique address, a randomly generated number, and a secret PIN (Personal Identification Number) to facilitate a secure key-exchange over an as-yet-unsecured channel. The initiation process typically calls for the PIN to be manually entered into the Bluetooth device.
[0006] The Bluetooth initiation protocol is apparently based on a paradigm of two Bluetooth users coming within range of each other, or, a single user having direct access to both Bluetooth devices at the same time, such as a user of a Bluetooth-enabled PDA (Personal Data Assistant) arriving at a Bluetooth-enabled ATM (Automated Teller Machine). For example, the user arrives at the ATM and the Bluetooth initiation process commences based on the aforementioned detection of emanations from one or both of the Bluetooth-enabled devices. The user is prompted to enter the PIN on the PDA, for example, then prompted for a confirmation via a keypad on the ATM. Obviously, a user would not want to commence the transaction with the ATM unless the user were at the locale of the ATM.
[0007] Difficulties, or at least inconveniences, present themselves when Bluetooth devices are physically distant from each other, and a sole user desires to establish communications between these devices. Even though the devices may be within a common 10 meter range of each other, communications will not be established unless and until the user interacts with each device to effect the selection of each other, to enter one or more PINs as required, and so on. If the devices are not co-located, the user must travel back and forth between each device as the initiation protocol is effected. In like manner, difficulties or inconveniences present themselves after devices are “paired” for communication via the exchange of PINs. When an actual communication between the devices is desired, such as the transfer of a file from one device to another, the user may be required to configure or re-configure each device as a master or slave for this communication, and in some cases, must configure each device to effect a particular communication scheme or protocol.
BRIEF SUMMARY OF THE INVENTION
[0008] It is an object of this invention to ease the task of initiating communications between two Bluetooth devices. It is a further object of this invention to provide a remote access device that facilitates communication between and among Bluetooth devices.
[0009] These objects and others are achieved by a remote access device that is configured to communicate with each Bluetooth device within a locale. When communication is desired between two Bluetooth devices within this locale, the remote access device allows the user to send commands and other information from the remote access device to each Bluetooth device to effect the initialization of the communication channel between the two devices. Using the remote access device, the user can make selections on each Bluetooth device, enter PINs as required, respond to confirmation requests, and the like. Because each Bluetooth device may be distant from the remote access device and distant from each other, the use of the remote access device allows a user to enable communications between the Bluetooth devices without traveling back and forth between physically separated Bluetooth devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention is explained in further detail, and by way of example, with reference to the accompanying drawings wherein:
[0011] [0011]FIG. 1 illustrates an example block diagram of a Bluetooth network in accordance with this invention.
[0012] [0012]FIG. 2 illustrates an example block diagram of a remote access device in accordance with this invention.
[0013] [0013]FIG. 3 illustrates an example block diagram of a Bluetooth device in accordance with this invention.
[0014] Throughout the drawings, the same reference numerals indicate similar or corresponding features or functions.
DETAILED DESCRIPTION OF THE INVENTION
[0015] [0015]FIG. 1 illustrates an example block diagram of a Bluetooth network 100 in accordance with this invention. Illustrated in FIG. 1 are three Bluetooth devices 110 , 120 , 130 , and a remote access device 150 . As in a conventional Bluetooth network, the devices 110 , 120 , 130 are configured to communicate with each other, but only after an initialization protocol is effected to enable the communication. This initialization protocol may be as simple as selecting each other device from a list of devices displayed on each device, identifying which device is master and which is slave, and so on. Because communication security is becoming more prevalent, the more common initialization protocol will also include security parameters, such as the user's PIN. For ease of reference, the information communicated during the initialization process is hereinafter termed “initialization information”, the receipt of which effects an enabling of communications between the devices.
[0016] Generally, the initialization information is communicated each time a communication channel is to be established between two “paired” Bluetooth devices, although the principles of this invention may also be extended to facilitate pairings between Bluetooth devices, as discussed further below.
[0017] In accordance with this invention, the remote access device 150 is first configured to be able to communicate with each Bluetooth device 110 - 130 . This may be effected in the conventional manner, by progressing from one Bluetooth device 110 - 130 to the next with the remote access device, and establishing a pairing between each Bluetooth device 110 - 130 and the remote access device 150 , by entering a common PIN in each.
[0018] If a particular Bluetooth device lacks an input means for entering a PIN, the device is configured to have an internal PIN that is provided to the user. To establish a pairing between the remote access device 150 and this particular device the user merely enters the internal PIN into the remote device 150 while the remote device 150 is in the vicinity of this particular device.
[0019] If a particular Bluetooth device includes the ability to accept input information from a remote controller, such as an infrared controller, and if the remote device 150 also includes the means, such as an infrared transmitter, to provide this remote input information, the remote access device 150 can be establish the pairing with this particular Bluetooth device remotely.
[0020] After the remote access device 150 is paired to each of the Bluetooth devices 110 , 120 , 130 , the remote access device 150 facilitates the initialization protocol for specific communications by allowing a user the opportunity to respond to requests for initialization information from each of the Bluetooth devices 110 , 120 , 130 via the remote access device 150 . In the simple initialization protocol, for example, a Bluetooth device 110 may communicate a list of authorized/paired devices 120 , 130 to the remote access device 150 for the user to select the appropriate device with which to effect the initialization process. Alternatively, as detailed further below, the remote access device 150 may be configured to display a list of authorized/paired devices from its internal memory, to allow a user to effect the initialization protocol between select devices by selecting devices from the list.
[0021] By allowing the user to initiate actions or respond to queries via the remote access device 150 , the user can effect the initialization of communications between two Bluetooth devices without having to travel from one device to the other as the initialization protocol sequence progresses. A typical initialization process for establishing secure communications follows.
[0022] A user accesses the remote access device 150 and requests a list of available Bluetooth devices. These devices are generally the devices that have been previously paired with the device 150 and are currently in range of the device 150 . From this list, the user selects a master device, such as device 110 , and a slave device, such as device 130 , and then initiates a “connect” sequence. If the devices 110 and 120 have previously been accessed by the device 150 , the device 150 merely communicates the previously defined initialization information to each of the devices 110 and 130 , or, the device 150 serves as a relay for the transfer of information between each device 110 and 130 . Alternatively, the devices 110 and 130 may be configured to transfer information between each other upon receipt of the initialization information from the device 150 . These and other protocols for effecting the initialization protocol between two devices 110 , 130 via a remote device 150 that provides user commands to each of the devices 110 , 130 will be evident to one of ordinary skill in the art in view of this disclosure.
[0023] In a preferred embodiment of this invention, the remote access device 150 is configured as a remote control device as well. The PCT International Publication WO 01/20572, “REMOTE CONTROL OF AN ELECTRONIC DEVICE THROUGH DOWNLOADING OF CONTROL INFORMATION IN A MOBILE STATION”, filed 10 Sep. 1999 for John R. Bell, and incorporated by reference herein, discloses a portable device that is configured to download control information for an other device, and thereafter uses this information to control the other device. Of particular note, this referenced publication discloses the remote control of Bluetooth devices via a programmable portable device. In the context of this invention, the control information may be preprogrammed into the remote device 150 , or the control information may be communicated to the remote device 150 from the particular device 110 , 120 , 130 , or from a remote source, such as an Internet site. In this manner, the remote access device 150 provides the functionality of a remote control device as well as a device that facilitates the enabling of communication between Bluetooth devices.
[0024] [0024]FIG. 2 illustrates an example block diagram of a remote access device 150 in accordance with this invention. The device 150 includes a keypad 210 , or other input device, for accepting user directives, typically in response to messages that are displayed on a display 220 , or other rendering device. For example, the input device 210 and/or rendering device 220 may be audio devices, video devices, or any other devices that effect input and output transactions with a user. The device 150 also includes a communicator 240 for communicating with Bluetooth devices, and a controller 250 that controls the operation of each of the devices 210 , 220 , and 240 . A preferred embodiment of the remote access device 150 also includes a memory for storing initialization information and other material that facilitates the enabling of communications between external devices, such as devices 110 , 120 , 130 of FIG. 1.
[0025] [0025]FIG. 3 illustrates an example block diagram of a Bluetooth device 110 in accordance with this invention. The device 110 includes a functional element 310 that provides the primary functionality of the device 110 , such as a television function, a PDA function, and so on. The device 110 also includes a communicator 340 , a controller 350 , and a memory 360 that facilitate the enabling of communication with other Bluetooth devices. In a conventional Bluetooth device, the interaction with the user to effect communication with other Bluetooth devices is effected locally. In accordance with this invention, the Bluetooth device 110 is configured to also effect the interaction with the user via the communicator 340 . Messages are transmitted from the device 110 , and responses or commands from the remote access device 150 of FIGS. 1 and 2 are received via the communicator 340 in the device 110 and the communicator 240 in the device 150 . As noted above, in a preferred embodiment, the functional element 310 is also remotely controllable by the remote access device 150 , via the communicators 240 , 340 .
[0026] The foregoing merely illustrates the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are thus within its spirit and scope. For example, although the invention is presented above with a remote access device 150 that is separate and distinct from Bluetooth devices 110 , 120 , 130 , the functionality of the remote access device 150 could be built into select Bluetooth devices, such as PDAs, palmtop and laptop computers, and so on. In like manner, the functionality of the remote access device 150 could also be incorporated into traditional stationary devices, such as televisions, personal computers, and so on, to allow a user to effect communication between devices from the Bluetooth device that is most convenient to the user at the time. These and other system configuration and optimization features will be evident to one of ordinary skill in the art in view of this disclosure, and are included within the scope of the following claims.
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A remote access device is configured to communicate with each Bluetooth device within a locale. When communication is desired between two Bluetooth devices within this locale, the remote access device allows the user to send commands and other information from the remote access device to each Bluetooth device to effect the initialization of the communication channel between the two devices. Using the remote access device, the user can make selections on each Bluetooth device, enter PINs as required, respond to confirmation requests, and the like. Because each Bluetooth device may be distant from the remote access device and distant from each other, the use of the remote access device allows a user to enable communications between the Bluetooth devices without traveling back and forth between physically separated Bluetooth devices.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to a ceiling panel and, more particularly, to a clip which is provided on the edge of the ceiling panel to space the edges of the ceiling panel from the vertical webs of the runners supporting the ceiling panel and to lock the ceiling panel in position within the runners.
2. Description of the Prior Art
U.S. Pat. No. 4,712,350 discloses the use of a bump 30 on the vertical web of a runner to position a ceiling panel relative the vertical web. This structure in no way teaches or suggests the invention described below.
Summary of the Invention
The invention is directed to a corner clip for a ceiling panel in a suspended ceiling system. The corner clip is formed with a right angle shaped base with two arms. Adjacent the intersection of the two arms a ringed post projects from the base. A ceiling panel is provided within a suspended ceiling system which comprises four inverted T-shaped runners. Each runner has a flange upon which the ceiling panel may sit and a vertical web which is to be spaced from the edge of the ceiling panel. At least one corner clip is provided in a corner of the ceiling panel. A hole is provided in the corner of the ceiling panel and the post of the corner clip is pressed into the hole in the corner of the ceiling panel and the two arms of the corner clip engage adjacent vertical webs of the ceiling runners to space the edge of the ceiling panel from the edge of the vertical web of a runner.
An alternate structure can be used. A round disc clip is provided with a ringed post in the center of the disc. At least one disc is provided along one side of the ceiling panel. A hole is provided along one edge of the ceiling panel and the post of the disc is pressed into the hole. The edge of the disc engages the adjacent vertical web of the ceiling runner to space the edge of the ceiling panel from the edge of the web of the runner.
This results in the positioning of the ceiling panel in the center of the opening in the grid structure so that the ceiling panel is supported on at least two edges by the flanges of the runners, and the ceiling panel is locked in position so that it cannot shift to disengage from the flanges of the runners.
DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the corner clip.
FIG. 2 is a cross-section view of the location of the corner clip relative the ceiling panel and the ceiling runner.
FIG. 3 is a top view of the corner clip in position.
FIG. 4 is a perspective view of the round disc.
FIG. 5 is a cross-section view of the location of the round clip relative the ceiling panel and the ceiling runner.
FIG. 6 is a top view of the round clip in position.
FIG. 7 is a cross-section view of the corner clip in position.
FIG. 8 is a cross-section view of the round clip in position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A corner clip 2 is provided for ceiling panels which are supported in a suspended ceiling system. At least two corner clips are used on two adjacent corners of the ceiling panel. The corner clip is a flat right angle shaped base structure with two arms 6 and 8. Adjacent the intersection of the two arms a ringed post 10 projects from the base.
At least one ceiling panel 4 is provided in a suspended ceiling system. The suspended ceiling system is composed of four inverted T-shaped runners 12. Each runner has a bulb member 13, a vertical member 14 and a horizontal member 16. The ceiling panel is supported on the horizontal members of at least two opposite runners. It is desired that the ceiling panel have its edges 18 and corners spaced from the vertical web 14 of the runners. The spacing of the edges of the ceiling panel from the vertical webs locates the ceiling panel centrally of the four adjacent runners and thus insures that the ceiling panel is fully supported on at least two opposite runner horizontal flanges. In at least two adjacent corners of the ceiling panel by a panel edge supported by a runner, there is provided a hole 20 which is partly bored in the ceiling panel. Into each of the holes 20, there is inserted the ringed post 10 which will hold the corner clips in position in the corner of the ceiling panel. The arms of each corner clip contact the vertical members 14 of two adjacent runners to maintain a fixed spacing between the edge of the ceiling panel and the runners' vertical member. It is clear that four corner clips could be used as a substitute for the two corner clip arrangement.
The above corner clip and the following round clip are particularly useful as locking clips with a removable ceiling panel. Such a panel has two opposite sides that do not have a flange 17 above the kerf. Therefore, these two sides do not have the sides supported on the horizontal member 16 of a runner 12. The other two opposite sides have flanges 17 that rest on the horizontal member 16 to support those two sides, and therefore the ceiling panel, on the runners of the ceiling suspension system. The locking clips hold the ceiling panel in position so that the horizontal members are not disengaged from the panel.
FIG. 2 shows the kerf 19 which is on the left side of the ceiling panel 4. The depth of the kerf 21 on the right side of the adjacent ceiling panel is less than the depth of kerf 19. Kerf 21 would be the size of the kerf on the right side of ceiling panel 4. Each ceiling panel has a kerf 21 on one side and a kerf 19 on its opposite side. Because of the deeper kerf 19, the panel may be moved in the direction of the deeper kerf and this, in turn, will permit the kerf 21 to disengage from its runner horizontal member. Lowering the disengaged side below its horizontal member and moving the ceiling panel in the direction of the disengaged side will permit kerf 19 to disengage from its horizontal member. The corner and round clips placed on the side with the deeper kerf lock the ceiling panel in position and will prevent accidental movement of the ceiling panel in the direction of the deeper kerf and possible disengagement of the ceiling panel from its horizontal members.
FIGS. 4-6 show the use of the round disc clip. The round disc clip 22 is provided for ceiling panels which are supported in a suspended ceiling system. At least one disc clip is used on one side of the ceiling panel. The disc clip is a flat circular structure 24. From the center of the disc, a ringed post 26 projects from the flat circular structure 24.
At least one ceiling panel 4 is provided in a suspended ceiling system. The suspended ceiling system is composed of four inverted T-shaped runners 12. Each runner has a bulb member 13, a vertical member 14 and a horizontal member 16. The ceiling panel is supported on the horizontal members of at least two opposite runners. It is desired that the ceiling panel have at least two edges 18 spaced from the vertical web 14 of the runners. The spacing of the edges of the ceiling panel from the vertical webs locates the ceiling panel so that it is fully supported on at least two opposite runner horizontal flanges. Along one side of the ceiling panel there is provided a hole 20 which is partly bored in the ceiling panel. Into the hole 20 there is inserted the ringed post 26 which will hold the disc clip in position. The edge 28 of the flat circular structure 24 contacts the vertical member 14 of the adjacent runner to maintain a fixed spacing between the edge 18 of the ceiling panel 4 and the runner vertical member. Two disc clips could be used on one edge of the ceiling panel near each end of the panel edge. With a removable ceiling panel, the disc clip is placed on the side of the panel with the deeper kerf.
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A corner clip is provided on the edge of a ceiling panel and the end(s) of the clip space the panel from the ceiling runner vertical web. The clip can be a right angle shape having a downwardly projecting portion which fits into a recess in the back of the ceiling panel. The clip can be a disc shape having a downwardly projecting portion which fits into a recess in the back of the ceiling panel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a non-provisional of U.S. Provisional Application No. 61/426,985, entitled “DUAL CURRENT-MODE CONTROLLER FOR REGULATION OF ELECTROSURGICAL GENERATOR OUTPUT POWER,” which was filed on Dec. 23, 2010. This application is also a non-provisional of U.S. Provisional Application No. 61/530,528, entitled “CONSTANT POWER SOURCE BY NONLINEAR CARRIER-CONTROL OF A BUCK CONVERTER FOR USE IN AN ELECTROSURGICAL GENERATOR,” which was filed on Sep. 2, 2011. All of the contents of the previously identified applications are hereby incorporated by reference for any purpose in their entirety.
BACKGROUND OF THE INVENTION
An electrosurgical generator is commonly used in surgical practice to perform arc cutting and coagulation. The electrosurgical generator produces a high-frequency electric current to cut tissue with limited blood loss and enhanced cutting control compared to a metal blade. Standard industry practice is for electrosurgical generators to measure and average the alternating current (AC) output power over several cycles and use a low-bandwidth control loop to adjust the duty cycle of a pulse width modulated (PWM) converter, modulating the carrier of a fixed-output-impedance resonant inverter to achieve the desired output characteristic. However, the feedback control loop and several cycles average gives rise to latency issues.
One example of an industry practice is for electrosurgical generators to mimic medium-frequency (MF) amplitude modulated (AM) broadcast transmitters via a method commonly called the Kahn Envelope Elimination and Restoration technique. Such generators typically use a class-D or class-E RF output stage operating with constant voltage amplitude at the electrosurgical analogy of a carrier frequency. In various known embodiments, the generators are combined with an efficient converter power supply amplitude modulator, sometimes referred to as a class-S modulator. The converter power supply amplitude modulator may be configured to regulate the RF output voltage, current, or power dissipated in the tissue load to a desired power versus impedance characteristic called a power curve.
The assumption of such a technique is that the tissue load changes at rates substantially lower than the audio frequency (AF) band. However, this assumption is not entirely accurate when viewed through the prism of arcing, which is the primary mechanism of cutting and coagulation in electrosurgery. Arcing in electrosurgery can extinguish and re-ignite in the middle of a cycle, and changes in its characteristics can occur on scales much broader than the AF. Therefore, this assumption may be one of convenience more so than fact, since the feedback of RE for purposes of control is well known to be very difficult due to the lag introduced by most common feedback controller techniques.
The commonly used envelope feedback regulation for electrosurgery is accomplished by measuring and averaging the alternating current (AC) output power and load impedance via voltage and current sensor feedback over many (sometimes hundreds) of cycles. This approach is complex, and its slow response during arcing leads to poor regulation of the AC output power, resulting in undesirable thermal spread or other well known tissue damage such as charring and scarring. Thus, a need exists for an electrosurgical generator that overcomes these and other deficiencies.
SUMMARY OF THE INVENTION
Using a high frequency inverter to form an arc between the output of an electrosurgical generator and tissue of a patient, a surgeon can induce joule heating in the affected cells; this causes the desired surgical effects of cutting, coagulation, and dissection. In an exemplary embodiment, the electrosurgery utilizes joule heating produced by the electrosurgical generator. The electrosurgical generator produces an accurate power source output characteristic, to which maximum voltage and current limits are added. The voltage and current limits of the electrosurgical generator contribute to the safety of the process. Furthermore, in an exemplary embodiment the voltage and current limits are configured to produce particular tissue effects which may be desirable in various surgical applications.
In an exemplary embodiment, an electrosurgical generator control system produces constant power output without measuring output voltage or output current, and regulates the output power with substantially deadbeat control. The electrosurgical generator control system performs near deadbeat control by regulating inductor current to a specified value, equal to a reference current. Thus, in an exemplary embodiment, the electrosurgical generator control system achieves a desired inverter output characteristic with an efficient and substantially deadbeat control method for AC output power. Furthermore, an exemplary electrosurgical generator control system switches between operating modes based in part on at least one of a measured output voltage, a measured inductor current, and by observing a duty cycle command generated by the control system. Additionally, an exemplary control system provides the ability to adjust the voltage and current limits and facilitate precision control of desired tissue effects. The desired tissue effects may include at least one of cut depth and the amount of surface hemostatis versus thermal spread.
Compared to prior art electrosurgical generators, an exemplary electrosurgical generator reduces unintended tissue damage by improving regulation of output power. In accordance with an exemplary embodiment, an electrosurgical generator controls the power during a cycle, and reacts to a change in power if arcing occurs. Voltage sources, especially, demonstrate the tendency to have large, uncontrolled power excursions during normal electrosurgical use. The magnitude of the power excursions may be dependent on various factors. One factor is how far the surgeon is away from the tissue when an arc occurs in the sinusoidal cycle. Furthermore, in the prior art, the current sources may introduce long, unintended arcs, even if distance from the tissue was well controlled. Therefore, in an exemplary embodiment, the electrosurgical generator may be configured to control power within a carrier frequency cycle for full arc and plasma control throughout the cycle. Power control within the duration of a carrier frequency cycle is advantageous over the prior art systems because arcing occurs faster than typical voltage or current detection feedback mechanisms can respond.
Furthermore, the exemplary electrosurgical generator is less complex than prior art electrosurgical generators. Moreover, it is an objective of this application to present an inverter topology and control algorithm which combines current-mode and voltage-mode control to realize the desired output characteristic of an electrosurgical generator in a markedly simpler and more accurate fashion. By directing which of two conversion stages is to be current-mode controlled, constant power, constant current, and constant voltage outputs can be achieved with excellent regulation and fast transitions.
In an exemplary embodiment, effective regulation of an electrosurgical generator's output is important to achieving the desired clinical effects. If output power is allowed to exceed the desired value, excessive thermal spread may occur, unnecessarily damaging and scarring tissue and impeding healing. If maximum output voltage exceeds the limiting value, charring of tissue may occur, which is frequently undesirable as it may unnecessarily damage tissue and obscure the surgical field. Use of an exemplary electrosurgical generator control scheme in an electrosurgical generator can provide near-deadbeat regulation of output power. In addition, the electrosurgical generator control scheme tends to assure that thermal spread is minimized by accurately supplying the specified power within a few cycles. Additionally, in various embodiments, fast and accurate regulation provided by the constant voltage mode minimizes unintentional tissue charring. Thus, reduced thermal spread and charring should result in better surgical outcomes by reducing scarring and decreasing healing times.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
A more complete understanding of the present invention may be derived by referring to the detailed description and draft statements when considered in connection with the appendix materials and drawing figures, wherein like reference numbers refer to similar elements throughout the drawing figures, and:
FIG. 1 illustrates a schematic of an electrosurgical generator circuit, in accordance with various embodiments;
FIG. 2 illustrates a graphical representation of desired output characteristics, in accordance with various embodiments;
FIG. 3 illustrates a schematic of an electrosurgical generator circuit, in accordance with various embodiments;
FIG. 4 illustrates a schematic of an exemplary electrosurgical generator in constant power output mode, in accordance with various embodiments;
FIG. 5 illustrates a schematic of an exemplary electrosurgical generator circuit with buck converter and boost inverter control, in accordance with various embodiments;
FIG. 6 illustrates another graphical representation of desired output characteristics, in accordance with various embodiments;
FIG. 7 illustrates a schematic of an exemplary buck converter circuit with current programmed mode control, in accordance with various embodiments;
FIG. 8 illustrates a graphical representation of the interaction between the nonlinear carrier control current limit and measured inductor current, and the establishing of a corresponding duty cycle, in accordance with various embodiments;
FIG. 9 illustrates yet another graphical representation of desired output characteristics using duty cycle limits, in accordance with various embodiments; and
FIG. 10 illustrates a schematic of an exemplary non-dissipative snubber circuit, in accordance with various embodiments.
DETAILED DESCRIPTION
While exemplary embodiments are described herein in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that logical electrical and mechanical changes may be made without departing from the spirit and scope of the invention. Thus, the following detailed description is presented for purposes of illustration only.
In accordance with an exemplary embodiment, an electrosurgical generator controller operates with near-deadbeat control to maintain a desired AC output of an electrosurgical generator, which operates in at least one of a constant voltage mode, a constant current mode, and a constant power mode. The mode selection is generally based on the impedance associated with the tissue being cut. Different types of tissue, such as muscle and fat, have different impedances. In terms of electrosurgical operations, constant power output tends to uniformly vaporize tissue, resulting in clean dissection. Whereas constant voltage output tends to explosively vaporize or carbonize tissue (“black coagulation”), and constant current output tends to thermally coagulate tissue without vaporization (“White coagulation”). Carbonization is surgically useful if the surgeon wishes to rapidly destroy surface tissue, and thermal coagulation is regularly coupled with mechanical pressure to seal hepatic or lymphatic vessels shut. However, it is desirable for the surgeon to operate using constant power output and importantly, return to using constant power output as quickly as possible if there is deviation.
With reference to the schematic shown in FIG. 1 , in an exemplary embodiment, an electrosurgical generator 100 comprises a DC-DC buck converter 101 , a DC-AC boost inverter 102 , an inductor 103 , a transformer 104 , and an electrosurgical generator (ESG) control system 110 . In the exemplary embodiment, a DC voltage source Vg is electrically coupled to DC-DC buck converter 101 . Furthermore, inductor 103 is electrically coupled between DC-DC buck converter 101 and DC-AC boost inverter 102 . The output of DC-AC boost inverter 102 transmits power to the primary winding of transformer 104 , which passes through the secondary winding of transformer 104 to the load Z. Additionally, the load Z changes because tissue impedances vary, and also changes because the cutting process is an arc process. The impedance of an arc varies as it goes through several “phases” of formation and eventual extinguishment within a carrier frequency cycle.
In an exemplary embodiment, ESG control system 110 is in communication with both DC-DC buck converter 101 and DC-AC boost inverter 102 . The ESG control system 110 is configured to control the duty cycle d 1 of DC-DC buck converter 101 and the duty cycle d 2 of DC-AC boost inverter 102 . Additionally, ESG control system 110 is configured to measure power characteristics of electrosurgical generator 100 , and control electrosurgical generator 100 based at least in part on the measured power characteristics. Examples of the measured power characteristics include the current through inductor 103 and the voltage at the output of DC-AC boost inverter 102 . In various embodiments of control modes, ESG control system 110 controls buck converter 101 by generating duty cycles based on a combination and/or selection of duty cycle inputs from various controllers depending on the mode of operation (e.g., constant current, constant power, or constant voltage).
With respect to the AC output of the electrosurgical generator and in exemplary embodiments, “constant power” is defined to mean the average power delivered in each switching cycle is regulated to a substantially fixed value. Likewise, “constant voltage” and “constant current” are defined as the rms value of the AC voltage or current, respectively, being regulated to a substantially fixed value. In various embodiments, the substantially fixed values of the constant power, constant voltage, and constant current may be selected by a user or selected from a lookup table. In accordance with an exemplary embodiment, ESG control system 110 comprises a current-mode controller 111 , a voltage-mode controller 112 , a mode selector 113 , and steering logic 114 . In one exemplary embodiment, mode selector 113 compares the output voltage V out (t) and the inductor current i L (t) to “predetermined limits” (discussed in further detail herein) in order to determine the desired mode of operation of electrosurgical generator 100 . An exemplary graphical representation of the desired output characteristics is illustrated in FIG. 2 . In an exemplary embodiment, as the load impedance increases and causes the voltage to increase, the corresponding increasing output voltage triggers the transitioning of the operating mode from constant current (A) to constant power (B) to constant voltage (C). Similarly, in an exemplary embodiment, as the load impedance decreases and causes the current to increase, the corresponding decreasing output voltage triggers the opposite transitioning from constant voltage (C) to constant power (B) to constant current (A) operating modes.
In various embodiments, a constant power mode may be maintained by varying just the duty cycle of a DC-AC boost inverter. With reference to FIG. 3 , an ESG control system 310 comprises a current-mode controller 311 , a voltage-mode controller 312 , a mode selector 313 , and steering logic 314 . In this exemplary embodiment, current-mode controller 311 compares the inductor current i L (t) to a control current limit i C . In an exemplary embodiment, the control current limit i C is set by a user, or provided by a look-up table. In an exemplary embodiment, current-mode controller 311 uses a latch circuit to generate a switching waveform δ(t) with a duty cycle d 1 . The inputs of the latch circuit are the current comparison and a clock signal. In an exemplary embodiment, the switching waveform δ(t) is switched “high” at the start of a switching period if the inductor current i L (t) is lower than control current limit i C . Furthermore, in the exemplary embodiment, the switching waveform δ(t) is switched “low” in response to the inductor current i L (t) exceeding the control current limit i C . In other words, a comparison of the inductor current i L (t) to control current limit i C facilitates adjusting the inductor current i L (t) to match the control current limit i C . For small inductor current ripple, in other words Δi L <<i L , the current-mode controller regulates the inductor current i L (t) to an approximately constant value, substantially equal to control current limit i C .
In various embodiments and with continued reference to FIG. 3 , voltage-mode controller 312 comprises a comparator 321 , a compensator 322 , and a pulse-width modulator 323 . Furthermore, in various embodiments, voltage-mode controller 312 compares the output voltage v out (t) with a reference voltage V max at comparator 321 . The output of comparator 321 is communicated to compensator 322 which in turn outputs an error signal that drives PWM 323 . In the various embodiments, the output of compensator 322 is an input signal to PWM 323 , which sets the duty cycle d 2 of the signal.
Furthermore, in various embodiments, mode selector 313 comprises an encoder and performs multiple comparisons. The output voltage v out (t) is compared with a first voltage limit V limit _ 1 to generate “signal a”. The output voltage v out (t) is compared with a second voltage limit V limit _ 2 to generate “signal b”. Similarly, the inductor current i L (t) is compared with a first current I limit _ 1 to generate a “signal c”. The inductor current i L (t) is compared with a second current limit I limit _ 2 to generate a “signal d”. In one exemplary embodiment and with reference to Table 1, the mode selection is set by mode selector 313 based on the above described comparisons. Table 1 lists comparison outcomes and corresponding mode. In an exemplary embodiment, Table 1 lists a “1” value if the output voltage or inductor current is greater than the compared limit, and a “0” value if the output voltage or inductor current is less than the compared limit. For example, if output voltage v out (t) exceeds both the first voltage limit V limit _ 1 and the second voltage limit V limit _ 2 , then the encoder selects the constant voltage mode. Further, the second voltage limit V limit _ 2 is equivalent to reference voltage V max , the same used in the comparison at voltage-mode controller 312 .
TABLE 1
a
b
c
d
Mode
0
0
1
1
I
1
0
1
0
P
1
1
0
0
V
Constant Power Output
In various embodiments, constant AC power output is achieved by setting duty cycle d 1 to a fixed value, and running the DC-AC boost inverter stage as a current-programmed boost inverter by varying duty cycle d 2 . As previously mentioned, electrosurgical generator controller 310 performs near deadbeat control by regulating inductor current to an approximately constant value, equal to a control current limit i C . For illustration purposes, FIG. 4 represents an exemplary schematic of the electrosurgical generator in constant power output mode.
In steady-state, the average voltage of v 1 (t) is constant in response to the input voltage Vg being constant, the DC-DC buck converter being bypassed by being set to 100% duty cycle, and no average voltage being able to exist across inductor L. The use of current programmed mode control results in the average current of i 1 (t) being regulated to an approximately fixed value with deadbeat or near-deadbeat control. In order to regulate i 1 (t), duty cycle d 2 is varied by the current mode controller to maintain i 1 (t) at a fixed value. Given the fixed voltage v 1 and current i 1 , the power at input of DC-AC boost circuit 102 (i.e., a switch network) is also constant. In an exemplary embodiment, the switch network is nearly lossless, resulting in the output power being approximately equal to the input power. Since the input power is constant, the output power of DC-AC boost circuit 102 is also constant.
Constant Voltage Output
In various embodiments and with renewed reference to FIG. 3 , constant voltage output is achieved by setting duty cycle d 1 of DC-DC buck converter 101 to a fixed value, and using voltage-mode control for duty cycle d 2 of DC-AC boost circuit 102 . In an exemplary embodiment, the voltage-mode control involves measuring the output voltage v out (t) of DC-AC boost circuit 102 with a sensor network, feeding the sensed output voltage v out (t) to a control loop in voltage-mode controller 312 , and adjusting the converter's duty cycle command based on the relative difference between the measured output voltage v out (t) and the reference output voltage V max . In other words, the duty cycle d 2 is set to increase or decrease the output voltage to match V max . In an exemplary embodiment, V max may be set by a user or based on values in a look-up table.
Constant Current Output
In an exemplary embodiment, constant current output is achieved by operating DC-AC boost circuit 102 at a fixed duty cycle d 2 and current-mode controlling DC-DC buck converter 101 . In an exemplary embodiment, the current-mode control accurately controls the average inductor current such that the output of buck converter 101 is a constant current. In one embodiment, current-mode controller 111 compares inductor current i L (t) to control current limit i C , where the control current limit i C is a desired fixed value. In other words, electrosurgical generator controller 310 is configured to vary duty cycle d 1 in order to maintain inductor current i L (t) at the fixed value. In various exemplary embodiments, as with v out (t), i L (t) is measured with a sensor and not an estimated value. As a result, the constant current output mode produces an AC output current whose magnitude is regulated with near-deadbeat speed.
Mode Transition Via Direct Measurement
In various embodiments, an electrosurgical generator system implementing the three modes of constant power, constant voltage, or constant current produces a very fast, very accurate regulation of the AC output characteristic. Various modes are impacted by measured characteristics, while other modes do not need to respond to the same measured characteristics. Specifically, electrosurgical generator controller 310 may switch between operating modes based in part on measured output voltage v out (t). Furthermore, electrosurgical generator controller 310 may adjust the operating parameters in the constant voltage mode based on the measured output voltage v out (t). In other words, the selection of which stage of the converter to current-mode control may be achieved with minimal feedback and without a need for extraneous measurements, averaging, or feedback of the output.
Transitioning between the three modes, in an exemplary embodiment, is determined by monitoring the voltage of the primary winding of transformer 104 and the inductor current. As previously described, in accordance with one exemplary embodiment, the transition from one mode to the next is summarized in Table 1. An exemplary ESG transitions modes from constant current to constant power to constant voltage as the output voltage v out (t) increases. Specifically, in an exemplary embodiment, electrosurgical generator 300 operates in the constant current mode if the output voltage v out (t) is less than a first voltage limit V limit _ 1 . If the output voltage v out (t) exceeds the first voltage limit, electrosurgical generator 300 transitions to the constant power mode. If the output voltage v out (t) exceeds a second voltage limit V limit _ 2 , electrosurgical generator 300 transitions to the constant voltage mode, where the output voltage v out (t) is limited and held constant. In an exemplary embodiment, the first voltage limit V limit _ 1 and the second voltage limit V limit _ 2 are set by a user or from a look-up table.
Similarly, electrosurgical generator 300 transitions from constant voltage mode to constant power mode to constant current mode as inductor current i L (t) increases. Specifically, in an exemplary embodiment, electrosurgical generator 300 operates in the constant voltage mode if the inductor current i L (t) does not exceed a first current I limit _ 1 . If the inductor current i L (t) does exceed the first current I limit _ 1 , then the mode transitions to the constant power mode. If the inductor current i L (t) exceeds a second current limit I limit _ 2 , electrosurgical generator 300 transitions to the constant current mode, where the inductor current i L (t) is limited and held constant. In an exemplary embodiment, the first current limit I limit _ 1 and the second current limit I limit _ 2 are set by a user or from a look-up table.
ESG with Buck Converter and Boost Inverter Control
In accordance with various embodiments and with reference to FIG. 5 , an electrosurgical generator 500 having an ESG control system 510 comprises a current-mode controller 511 , a voltage-mode controller 512 , a mode selector 513 , and steering logic 514 . In various embodiments, the operational mode of electrosurgical generator 500 is one of constant (or maximum) current I max , constant power P 1 from a buck converter, constant power P 2 from boost inverter, or constant (or maximum) voltage V max . These modes are illustrated in an exemplary embodiment with reference to FIG. 6 . The output selection of mode selector 513 is communicated to steering logic 514 . In an exemplary embodiment, steering logic 514 controls which of at least one of current-mode controller 511 and voltage-mode controller 512 are enabled. Furthermore, steering logic 514 may select which conversion stage receives the output of current-mode controller 511 and/or voltage-mode controller 512 , in various embodiments, steering logic 514 switches between operating either DC-DC buck converter 101 or DC-AC boost inverter 102 with current-mode control for constant power, depending on which portion of constant power regions (P 1 or P 2 ) is currently the operating mode. For example, the voltage mode controller 512 and/or current mode controller 511 may adjust the duty cycles d 1 and/or d 2 for the operating mode (constant current mode, constant voltage mode, constant power P 1 , or constant power P 2 ). Furthermore, steering logic 514 selects the duty cycle that each of DC-DC buck converter 101 and/or DC-AC boost inverter 102 receives.
In various embodiments, the current-mode controller 511 compares the inductor current i L (t) to a nonlinear carrier control current limit i C (t). In an exemplary embodiment, the nonlinear carrier control current limit i C (t) is set by the selection of Pset, which may be done by a user, or provided by a look-up table. In an exemplary embodiment, current-mode controller 511 uses a latch circuit to compare inductor current i L (t) to control current limit i C (t), comprising either a current limit signal (I) or a power limit signal (P 1 ). The control signal for a P/I switch is the mode signal, which is communicated from mode selector 513 . The inputs of the latch circuit are a clock signal and the comparison of control current limit i C (t) and inductor current i L (t), comprising one of the current limit signal (I) or a power limit signal (P 1 ). The selection of the current-mode controller 511 output is in response to the current mode of the electrosurgical generator 500 . The operating mode of the electrosurgical generator 500 may be communicated from the output of mode selector 513 . In an exemplary embodiment, the switching waveform δ(t) is switched “high” at the start of a switching period if the inductor current i L (t) is lower than nonlinear carrier control current limit i C (t). Furthermore, in the exemplary embodiment, the switching waveform δ(t) is switched “low” in response to the inductor current i L (t) exceeding the nonlinear carrier control current limit i C (t). In other words, a comparison of the inductor current i L (t) to nonlinear carrier control current limit i C (t) facilitates adjusting pulse duration of buck converter's 101 duty cycle, as previously described.
To generate and control a constant current from electrosurgical generator 500 , the average value of inductor current i L (t) is controlled to be substantially equal to fixed control current limit K*Pset, which is a fixed, non-time varying value. For small inductor current ripple, in other words Δi L <<i L , the current-mode controller regulates the inductor current i L (t) to an approximately constant value, substantially equal to the fixed control current limit.
With respect to using a buck converter to generate substantially constant power (e.g., constant power P 1 ), implementation of a nonlinear carrier control current limit is further described. In addition to generating a constant power source based on varying just the duty cycle of a DC-AC boost inverter, a buck converter may also be configured to generate substantially constant power output. In accordance with various exemplary embodiments, substantially constant power output of a buck converter may be achieved by adjusting a duty cycle's active period for the buck converter, in an exemplary embodiment and with reference to FIG. 7 , a buck converter system comprises a power source Vg, a buck converter circuit 710 , a controller 720 , and a load 730 . The impedance of the load may be static or dynamic. In the various embodiments, the controller 720 receives a feedback signal 711 representative of the output of the buck converter 710 . In an exemplary embodiment, the feedback signal 711 is a measurement of the current passing through an inductor 712 coupled to buck converter circuit 710 .
In various embodiments, controller 720 receives real time feedback of the inductor current i L (t) from the buck converter. The feedback signal 711 is used by controller 720 to adjust the duration of the active and non-active portions of the duty cycle. Adjustment of the duty cycle portions in real time, or substantially in real time, may be configured to produce a constant power source from buck converter 710 . In various embodiments, two characteristics of the inductor feedback signal 711 are used to make the determination of duty cycle adjustments. The two characteristics are, first, the value of inductor current i L (t) and second, the slope of the change in the inductor current i L (t). These two characteristics may be used to provide implied information regarding the current and voltage of the output power into load 730 , and this implied information may be used to adjust the magnitude of the duty cycle in real time and produce substantially constant power output.
The pulse duration of the duty cycle of DC-DC buck converter 710 is varied using current mode controller 720 . The varying pulse duration of the duty cycle controls the inductor current i L (t), which is responsive to load 730 in contact with buck converter 710 . As the impedance of load 730 varies, the voltage across inductor 712 also varies, and the current through inductor 712 varies as well.
Described in more detail, at the beginning of the buck converter duty cycle, the active portion (also referred to as the pulse duration of the pulse period or the “on” portion) of the duty cycle is initiated. With respect to a buck converter, the active portion of the pulse period closes a switch between a power source and an inductor, thereby allowing power to flow through the inductor. In various embodiments and with reference to FIG. 8 , the inductor feedback signal i L (t) is compared to a nonlinear carrier control current i C (t). The nonlinear carrier control current i C (t) is a time-varying, nonlinear control signal that may be set for customized uses based on the desired output power. In response to the inductor feedback signal i L (t) exceeding the control current i C (t), the duty cycle switches to the non-active portion (also referred to as the “off” portion). The duty cycle stays in the non-active portion until the end of the pulse period. At the end of the pulse period, the cycle begins again with another pulse duration.
In various embodiments, the switching cycle has a fixed time period. Comparison of the inductor feedback signal i L (t) and the nonlinear carrier control current i C (t) is able to facilitate substantially constant power output based on a variable division of active and non-active portions of the duty cycle. As briefly described and with continued reference to FIG. 8 , the inductor current value and the slope of the change in the inductor current i L (t) are used to adjust the duty cycle. By way of example and without limitation, the inductor current slope affects the timing of how long the inductor current i L (t) is less than the nonlinear carrier control current i C (t). A lower slope value indicates that the inductor current i L (t) is increasing at a slower rate, and therefore it will take a longer period of time until the inductor current i L (t) exceeds the control current i C (t). In other words, the more time is takes for the inductor current i L (t) to exceed the control current i C (t), the longer the corresponding pulse duration. For example, see the comparison between the pulse duration at 2 T S and 3 T S . A higher slope value of inductor current i L (t) indicates that the inductor current is increasing at a quicker rate, and therefore it will take a shorter period of time until the inductor current i L (t) exceeds the control current limit i C (t). The shorter period of time results in the duty cycle staying in the active portion for a shorter period and having shorter pulse duration.
The nonlinear carrier control current i C (t) is part of a nonlinear carrier control (NLC) technique. In various embodiments, the NLC technique applied to the buck converter is based on a nonlinear time dependent variable, which is the nonlinear carrier. In various embodiments, the nonlinear time dependent variable is determined by the input voltage Vg, period of the switching cycle, and the desired power output. The application of NLC technique and production of substantially constant power output creates a buck converter that is a power source. In other words, the buck converter may implement NLC techniques to generate a fixed amount of power and be a power source. In contrast, prior art use of NLC techniques was typically configured to cause a converter to absorb a fixed amount of power and be a power sink. One of the benefits of using NIX control techniques is that a buck converter in combination with a boost inverter can produce a constant power source over a wider impedance range than using just a boost inverter alone. For example, an electrosurgical generator as described herein is capable of operating over an impedance range of about 64 to 4000 ohms. Using both a boost inverter and buck converter to source constant power facilitates operating over the wide impedance range without unreasonably high peak voltages.
In accordance with various exemplary methods, producing constant power output in a buck converter with a load having variable resistance includes turning on a switch of the buck converter at the beginning of the duty cycle to initiate a pulse, and monitoring the current through the inductor. The inductor current linearly increases while the buck converter is operating in the active portion of the duty cycle. The exemplary method may further include comparing, at a control circuit, the inductor current i L (t) to a nonlinear carrier control current i C (t), and turning off the switch of the buck converter in response to the magnitude of the inductor current meeting or exceeding the magnitude of the nonlinear carrier control current. In response to turning off the switch of the buck converter, the inductor current ramps down during the non-active portion of the duty cycle. The changing inductor current slope corresponds to the changing impedance of the load, which may be used to adjust the pulse duration of the duty cycle in order to produce substantially constant power output from the buck converter. In various embodiments, the nonlinear carrier control current is derived from the following equation:
i C ( t ) = P Vg * Ts t ,
where P is power at the load, Ts is the switching cycle period, Vg is the input DC voltage source magnitude, and t is the time (assuming t=0 occurs at the start of the switching cycle). Additionally, as is understood by one in the art, the inductor current has minor fluctuation during each cycle due to turning the buck converter on and off, and the minor fluctuation may not be due to any change in the load impedance. In various embodiments, changes to the load impedance result in a change in inductor current slopes and a change to the average value of the inductor current.
Although a buck converter with substantially constant power output is described in terms of implemention in an electrosurgical generator, such a buck converter may also be implemented in various applications, such as are welding and gas-discharge lamps (i.e. street lamps).
In an exemplary embodiment and with renewed reference to FIG. 5 , voltage-mode controller 512 comprises a comparator 521 , a compensator 522 , and a pulse-width modulator (PWM) 523 . Furthermore, in an exemplary embodiment, voltage-mode controller 512 compares the measured output voltage v out (t) with a reference voltage V max at comparator 521 . The output of comparator 521 is communicated to compensator 522 which in turn outputs an error signal that drives PWM 523 . In the exemplary embodiment, the output of compensator 522 is an input signal to PWM 523 , which sets the duty cycle d 2 of the signal in certain modes.
In various embodiments, constant voltage output may also be achieved by setting duty cycle d 1 of DC-DC buck converter 101 to a fixed value, and limiting the duty cycle d 2 of DC-AC boost inverter 102 to a maximum duty cycle d max . Implementing a duty cycle limit on DC-AC boost inverter 102 during the constant voltage output generally amounts to running DC-AC boost inverter 102 in an open-loop. In various embodiments, limiting the duty cycle d 2 of DC-AC boost inverter 102 to a maximum duty cycle d max results in poorer steady-state output voltage regulation in comparison to mode transitions using direct measurement, but provides the significant advantage of limiting the peak output voltage on a per-cycle basis, with little or no risk of transient overshoot. For various electrosurgical applications, the steady-state value of the maximum output voltage v out (t) is of lesser importance, as it would be unusual to operate in this output mode for any length of time. Per-cycle transient voltage limiting, however, may be highly useful as a means to limit potential undesirable arcing. Additionally, in various embodiments, a maximum duty cycle may be easily varied without the need to linearize an output voltage measurement or tune a compensator, and in this exemplary embodiment no sensor is required on the output since no direct measurement is taken.
Furthermore, configurations such as exemplary electrosurgical generator 500 may have additional inputs into the mode selection. In another exemplary embodiment and with reference to FIG. 5 , mode selector 513 comprises an encoder and performs multiple comparisons. The output voltage v out (t) is compared with three separate voltage limits (V limit _ 1 , V limit _ 2 , V limit _ 3 ) to generate three voltage comparison signals. Similarly, the inductor current i L (t) is compared with three separate current limits (I limit _ 1 , I limit _ 2 , I limit _ 3 ) to generate three current comparison signals. With reference to FIG. 6 , in various embodiments, mode selector 513 uses the voltage comparison signals and the current comparison signals to determine whether electrosurgical generator 500 is operating in the constant current output region (A), the region P 1 of the constant power output region (B), the region P 2 of the constant power output region (B), or the constant voltage output region (C). Furthermore, the output mode signal from mode selector 513 controls the switch position in steering logic 514 . Moreover, the output mode signal from mode selector 513 controls the switch position in current-mode controller 511 . For example, if output voltage V out (t) exceeds the first voltage limit V limit _ 1 , the second voltage limit V limit _ 2 , and the third voltage limit V limit _ 3 , then the encoder selects the constant voltage mode. The constant voltage mode signal from mode selector 513 would cause the switches' position of steering logic 514 to be “V”. As another example, if output voltage v out (t) exceeds the first voltage limit V limit _ 1 but does not exceed the the second voltage limit V limit _ 2 , and inductor current i L (t) exceeds first current limit I limit _ 1 and second current limit I limit _ 2 , but does exceed I limit _ 3 , then mode selector 513 determines that the operating mode is constant power P 1 . The constant power P 1 mode signal from mode selector 513 would cause the switches' position of steering logic 514 to be “P 1 ” as illustrated in FIG. 5 and Table 2. The values “1” and “0” represent any fixed value between 0% and 100% that is not closed-loop controlled. In other words, there is no feedback signal actively changing the fixed values represented by “1” and “0”.
TABLE 2
Duty cycle of buck and boost conversion stages by operating mode
Constant Current
Constant Power
Constant Power
Constant Voltage
I max
P 1
P 2
V max
Buck
ESG controlled with fixed
ESG controlled with nonlinear
1
1
Converter
control current limit
carrier control current limit
Boost
0
0
ESG controlled with fixed
Voltage mode
Inverter
control current limit
controlled
Constant Power Output
In an exemplary embodiment, constant AC power output is achieved by setting one or both of duty cycle δ 1 and duty cycle δ 2 to desired values. Moreover, electrosurgical generator 500 operates with constant AC power output in either a first constant power region P 1 or a second constant power region P 2 . In various embodiments, the converter switches between generating constant power using boost inverter 102 or buck converter 101 , depending on the impedance of the load. Moreover, in various embodiments, electrosurgical generator 100 may operate both boost inverter 102 and buck converter 101 at the same time, which results in a constant power output having a high voltage and low power.
In steady-state and operating in first constant power region P 1 , inductor current i L (t) is compared to a nonlinear carrier control current i C (t) in current-mode controller 511 . The pulse duration of the duty cycle of the DC-DC buck converter is varied using the current mode controller 511 . The varying pulse duration of the duty cycle controls the inductor current i L (t), which is responsive to the load in contact with the buck converter. As the impedance of the load varies, the voltage across the inductor v L (t) also varies, and the current through the inductor i L (t) varies as well. As previously described, at the beginning of the duty cycle, the active portion of the duty cycle is initiated. In response to the inductor current i L (t) exceeding the nonlinear carrier control current i C (t), the duty cycle switches to the non-active portion. The duty cycle stays in the non-active portion until the end of the duty cycle, upon which the next duty cycle begins in the active portion, in alternative embodiments, during the comparison of the inductor feedback signal i L (t) and the nonlinear carrier control current i C (t), once the control current exceeds the inductor current, the duty cycle switches to the active portion. In accordance with the exemplary embodiment, electrosurgical generator 500 generates constant power using buck converter 101 during first constant power region P 1 .
In steady-state and operating in second constant power region P 2 , the average voltage of v 1 (t) is constant in response to the input voltage Vg being constant, the DC-DC buck converter being bypassed by being set to 100% duty cycle, and no average voltage being able exist across inductor 103 . The use of current programmed mode control results in the average current of i 1 (t) being regulated to an approximately fixed value with deadbeat or near-deadbeat control. In order to regulate i 1 (t), duty cycle δ 2 is varied by the current mode controller to maintain i 1 (t) at a fixed value. Given the fixed voltage and current, the power at input of DC-AC boost inverter (i.e., a switch network) is also constant. In an exemplary embodiment, the switch network is nearly lossless, resulting in the output power being approximately equal to the input power. Since the input power is constant, the output power of DC-AC boost inverter 102 is also constant.
Constant Voltage Output
In an exemplary embodiment, constant voltage output is achieved by setting duty cycle δ 1 of DC-DC buck converter 101 to a fixed value, and duty cycle δ 2 of DC-AC boost inverter 102 is voltage-mode controlled. In an exemplary embodiment, the voltage-mode control involves measuring the output voltage v out (t) of DC-AC boost inverter 102 with a sensor, feeding the sensed output voltage to a control loop in voltage-mode controller 512 , and adjusting the converter's duty cycle command based on the relative difference between the measured output voltage and the reference output voltage. In other words, the duty cycle δ 2 is set to increase or decrease the output voltage to match V max . In an exemplary embodiment, V max may be set by a user or based on values in a look-up table. In an alternative embodiment, the boost inverter is run at a fixed duty cycle with no feedback of the output voltage.
Constant Current Output
In an exemplary embodiment, constant current output is achieved by operating DC-AC boost inverter 102 at a fixed duty cycle δ 2 and current-mode controlling DC-DC buck converter 101 . In an exemplary embodiment, the current-mode control accurately controls the average inductor current such that the output of buck converter 101 is a constant current. In one constant current embodiment, current-mode controller 511 compares inductor current i L (t) to a control current limit i C (t). In various embodiments, control current limit i C (t) may be a selected, fixed value or may be set by K*Pset, where K*Pset is a constant current set by the user during use. In various embodiments, Pset is set during the design stage. In other words, ESG control system 510 is configured to vary duty cycle δ 1 in order to maintain inductor current i L (t) at the fixed value. As a result, the constant current output mode produces an AC output current whose magnitude is regulated with near-deadbeat speed.
Electrosurgical Generator Modes
Similar to the transition of modes in electrosurgical generator 300 , in an exemplary embodiment, electrosurgical generator 500 also implements the three modes of constant power, constant voltage, or constant current to produce a very fast, very accurate regulation of the AC output characteristic. Various modes are impacted by measured characteristics, while other modes do not need to respond to the same measured characteristics. Specifically, ESG control system 510 switches between operating modes based in part on measured characteristics, such as inductor current and voltage. In other words, the selection of which stage of the converter to current-mode control is achieved with minimal feedback and without a need for extraneous measurements, averaging, or feedback of the output. Also, and as previously mentioned, the ESG control system 510 performs near deadbeat control by regulating inductor current to an approximately constant value, equal to a reference current.
Mode Transition Via Direct Measurement
Transitioning between the three modes, in an exemplary embodiment, is determined by monitoring the voltage of the primary winding of transformer 104 and the inductor current. Furthermore, the determination of transitioning between the modes may also based on the voltage and current of the primary winding of transformer 104 . In various embodiments, ESG control system 510 transitions modes from constant current to constant power to constant voltage as the output voltage v out (t) increases.
Specifically, in various embodiments, electrosurgical generator 500 operates in the constant current mode if the output voltage v out (t) is less than a first voltage limit (V limit _ 1 ). If the output voltage v out (t) exceeds the first voltage limit, electrosurgical generator 500 transitions to a first constant power mode (P 1 ). If the output voltage v out (t) exceeds a second voltage limit (V limit _ 2 ), electrosurgical generator 500 transitions to a second constant power mode (P 2 ). If the output voltage v out (t) exceeds a third voltage limit (V limit _ 3 ), electrosurgical generator 500 transitions to the constant voltage mode. Where the output voltage v out (t) is limited and held constant. In an exemplary embodiment, the first voltage limit (V limit _ 1 ), the second voltage limit (V limit _ 2 ), and the third voltage limit (V limit _ 3 ) are set by a user or from a look-up table.
Moreover, an exemplary ESG control system 510 transitions from constant voltage mode to constant power mode to constant current mode as inductor current i L (t) increases. Specifically, in an exemplary embodiment, electrosurgical generator 500 operates in the constant voltage mode if the inductor current i L (t) does not exceed a first current limit (I limit _ 1 ) if the inductor current i L (t) does exceed the first current limit (I limit _ 1 ), then the mode transitions to the second constant power mode (P 2 ). If the inductor current i L (t) exceeds a second current limit (I limit _ 2 ), then the mode transitions to the first constant power mode (P 1 ). If the inductor current i L (t) exceeds a third current limit (I limit _ 3 ), electrosurgical generator 500 transitions to the constant current mode, where the inductor current i L (t) is limited and held constant. In an exemplary embodiment, the first current limit (I limit _ 1 ), the second current limit (I limit _ 2 ), and the third current limit (I limit _ 3 ) are set by a user or from a look-up table.
Mode Transition Via Duty Cycle
In various alternative embodiments, the selection of operating modes may be based in part on the duty cycle. For example, if the electrosurgical generator is operating in constant power mode using the buck converter and the duty cycle reaches 100% active, the controller may be configured to switch to the constant power mode using the boost inverter. The switch to the boost inverter enables the electrosurgical generator to operate over a higher range of impedances.
In various embodiments, duty cycle limits may be used in the electrosurgical generator controller to control the mode transitions. With reference to FIG. 9 , in various embodiments, an exemplary mode selector may use duty cycle comparison signals to determine whether electrosurgical generator 500 is operating in the constant current output region (A), the region P 1 of the constant power output region (B), the region P 2 of the constant power output region (B), or the constant voltage output region (C).
In an exemplary embodiment, the duty cycle comparison signals are generated from the comparison of the buck converter duty cycle d buck (also referred to as d 1 herein) and the boost inverter duty cycle d boost (also referred to as d 2 herein) to at least four separate duty cycle limits (d limit _ 1 , d limit _ 2 , d limit _ 3 , and d limit _ 4 ). For example, if the buck converter duty cycle d buck exceeds the first duty cycle limit d limit _ 1 and the second duty cycle limit d limit _ 2 , and also the boost inverter duty cycle d boost exceeds the third duty cycle limit d limit _ 3 , then the electrosurgical generator operates in the constant voltage mode and constant voltage output region (C). Similarly, if the boost inverter duty cycle d boost is less than the third duty cycle limit d limit _ 3 , and the fourth duty cycle limit d limit _ 4 , and the buck converter duty cycle d buck is less than the first duty cycle limit d limit _ 1 , then the electrosurgical generator operates in the constant current mode and constant current output region (A). Further, as is illustrated in FIG. 9 , the duty cycle comparison signals may also result in the electrosurgical generator operating in the region P 1 of the constant power output region (B), or the region P 2 of the constant power output region (B). Therefore, in one exemplary embodiment, mode selector 513 is configured to determine the operating mode basd at least in part on comparisons of the buck converter duty cycle d buck and boost inverter duty cycle d boost to the duty cycle limits and to generate mode output signals to control steering logic 514 and/or current mode controller 511 .
In accordance with an exemplary embodiment, both the current-mode control 311 and the current-mode controller 511 may be able to maintain an approximately constant value of inductor current i L (t) by adjusting the current within 1-2 cycles. In another exemplary embodiment, the current-mode controller adjusts the inductor current within 1-10 cycles. In yet another embodiment, the current-mode controller adjusts the inductor within 10-100 cycles. Any of these examples may comprise a “low cycle” adjustemtn. This low cycle adjustment can be considered “deadbeat control” or “near-deadbeat control”. In accordance with an exemplary embodiment, near-deadbeat control minimizes unintentional charring by ensuring that only the requested quantum of power is delivered to the electrosurgical instrument. In the prior art, slow transient response of the converter to changes in load impedance may result in excessive delivery of power that may not be detected for 500 cycles or more. Stated another way, in an exemplary embodiment, an electrosurgical generator has an operating bandwidth of 100-500 kHz, compared to the prior art bandwidth of 1-10 kHz.
Although the mode transitions operate with near-deadbeat control, it still takes at least 1-2 cycles to change modes, and in some embodiments up to 100 cycles. Thus, should the load impedance suddenly increase while in either constant power mode, the converter will continue to supply constant power for the remainder of at least one cycle before transitioning to the constant voltage mode. In accordance with an exemplary embodiment and with reference to FIG. 10 , an electrosurgical generator further comprises a non-dissipative voltage snubber circuit 1000 to prevent undesirable voltage spikes. The snubber circuit 1000 may be coupled to an electrosurgical generator such as electrosurgical generator 300 or electrosurgical generator 500 . The non-dissipative voltage snubber circuit 1000 is coupled to the primary winding of the transformer 104 . In an exemplary embodiment, a duty cycle d S of snubber circuit 1000 is varied to maintain v CS (t) at a fixed value. Furthermore, instruments used for electrosurgery typically have leads that are several meters long. The long leads can result in an inductive load to the electrosurgical generator. Therefore, snubber circuit 1000 may further be configured to damp voltage spikes generated when switching the inductive load.
In general, any number of current, voltage, or duty cycle limits, and any number of subdivisions of constant current, constant power, or constant voltage modes may be used to facilitate operating mode selection and transition in order to provide near deadbeat control of an electrosurgical generator. The electrosurgical generator may include any electrosurgical generator control system comprising a mode selector that determines the current operating mode, steering logic that selects from the possible operating modes of constant current, constant power, or constant voltage, where the operating mode is based in part on the outputs of a current mode controller and a voltage mode controller. The operating mode and transitions between operating mode are configured to provide near deadbeat control of an electrosurgical generator having both a DC-DC buck converter and a DC-AC boost inverter.
Failure to maintain either accurate regulation of output power or sufficient means of voltage limiting may lead to higher output voltages, leading to unintentional charring, or higher output power, leading to unintentional thermal spread. The exemplary embodiments of the electrosurgical generators described herein accurately and quickly maintain the proper power characteristics, and allow a user to control the cutting process.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of any or all the draft statements. As used herein, the terms “includes,” “including,” “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, no element described herein is required for the practice of the invention unless expressly described as “essential” or “critical.”
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An electrosurgical generator may reduce unintended tissue damage by improving regulation of output power. The electrosurgical generator may control the power during a cycle, and react to a change in power if arcing occurs. Voltage sources, especially, demonstrate the tendency to have large, uncontrolled power excursions during normal electrosurgical use. The magnitude of the power excursions may be dependent on various factors. An exemplary electrosurgical generator control scheme reduces or minimizes the thermal spread by accurately supplying the specified power within a few cycles. Additionally, fast and accurate regulation provided by the constant voltage mode reduces or minimizes unintentional tissue charring. Thus, reduced thermal spread and charring should result in better surgical outcomes by reducing scarring and decreasing healing times. An electrosurgical generator controller may be configured to control both a DC-DC buck converter and a DC-AC boost inverter based in part on electrical parameters of the electrosurgical generator.
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BACKGROUND OF THE INVENTION
This invention relates to vehicle suspension apparatus, and more particularly, to a suspension apparatus including track frames mounted on a shaft.
In the mounting of a track frame on a shaft of a vehicle, so that the track frame is pivotable about the axis of the shaft, it is known to provide an inner track frame chamber wherein oil is contained for lubricating purposes. In general, the shaft has fitted to an end thereof a cap, and a retaining member is bolted to the track frame, the retaining member fitting tightly to the track frame so that oil within the track frame around the shaft is retained therein.
In the shipment of a vehicle such as that described, it is advantageous to remove the retaining member from its associated track frame, whereupon the cap secured to the end of the shaft becomes exposed. In such state, oil filling the chamber of that track frame may run past the end cap from the chamber therein and be lost.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the problems as set forth above.
In accordance with the present invention, the invention is a vehicle suspension apparatus comprising shaft means, and frame means mounted on the shaft means, and defining chamber means in which oil can be contained in the proximity of the shaft means. A cap is secured to the shaft means. A retaining member is secured to the frame means. Plate means are positioned between the cap and retaining member, the retaining member, plate means and cap acting to retain the frame means on the shaft means. Seal means are operatively associated with the plate means for providing sealing relation between the plate means and frame means for retaining oil contained in the chamber means.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects of the invention will become apparent from a study of the drawing, which is a sectional view of a portion of a vehicle incorporating the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Shown in FIG. 1 is a main frame 10 of a vehicle. A shaft 12 is disposed through an aperture 14 in the main frame 10, and a track frame 16 is mounted on the shaft 12 so as to be pivotable about the longitudinal axis of the shaft 12, appropriate bearings 18 being provided to allow such pivoting. The track frame 16 defines a chamber 20 in which oil is contained in the proximity of the shaft 12, the chamber 20 communicating with a drain passage 22 having a drain plug 24 therein.
A cap 26 is removably secured to an end of the shaft 12 by means of bolts 28, the cap 26 being disposed within a stepped bore 30 defined by the frame 16. Positioned within the bore 30 adjacent the cap 26 is a plate 32 defining an annular channel about the outer periphery thereof, in which is placed an annular elastomeric seal 34. The annular seal 34 is in sealing relation with the bore 30 of the frame 16. Both the cap 26 and the plate 32 can be removed freely from within the bore 30. A snap ring 36 is positionable within the bore 30 in the frame 16 to retain the plate 32 in the position shown.
A retaining member 38 is removably secured to the frame 16 by means of bolts 40. The retaining member 38 has a trunnion mount 42 thereon and includes an annular projecting portion 44 sized to fit within the bore 30 and having an extended surface 46 in close proximity to the plate 32. Thus, the plate is positioned between the cap 26 and retaining member 38, and the retaining member 38, plate 32 and cap 26 act to retain the frame 16 on the shaft 12.
The plate 32 defines a threaded bore 48 therethrough in which is disposed a removable threaded bolt 50.
It will be seen that with the parts positioned as thus far described, with a lateral, rightward load on the shaft 12 generally along the longitudinal axis thereof, i.e., directed toward the retaining member 38, the cap 26 is in contact with the plate 32 which is in turn in contact with the retaining member 38. Thus, high lateral loads placed on the shaft 12 are taken by the retaining member 38 during normal operation of the vehicle. During such normal operation, it will be understood that chamber 20 is substantially filled with oil.
Upon removal of the retaining member 38 for purposes of shipping the vehicle, the snap ring 36 retains the plate 32 in place, and the seal 34 continues to provide sealing relation between the plate 32 and the frame 16, so that oil is retained in the chamber 20. With the vehicle in such state, it will be noted that the vehicle can be moved for purposes of shipping thereof.
It will be seen that in such state, the plate 32 is retained in place relative to the frame by the snap ring.
If it is desired that the plate 32 be removed subsequent to removal of the retaining member 38, oil may be drained from the chamber 20 by removal of the drain plug 24. The bolt 50 may then be removed from the plate 32, so that the plate 32 defines passage means 48 therethrough. The passage means 48 allow air to flow from the outside of the plate 32 to the inside thereof in the area of the cap 26, so as to allow relatively easy removal of the plate 32 from within the bore 30. Such removal would be rather more difficult without such passage means 48 being provided, since air would by necessity have to flow past the annular seal 34 upon withdrawal of the plate 32. Also, to aid in removal of the plate 32, a long threaded bolt (not shown) may be threadably disposed through the bore 48, and brought into contact with the cap 26, whereupon further rotation of the long bolt will draw the plate 32 away from the cap 26 and from the bore 30 defined by the frame 16.
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A vehicle suspension apparatus includes a shaft on which track frames are pivotally mounted, the shaft at the ends thereof having fitted on each end thereof a cap, the track frame on that end having secured thereto a retaining member with a plate in sealing relation with the track frame and disposed between the cap and retaining member.
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FIELD OF THE INVENTION
[0001] This invention relates to gaming techniques and, in particular, to a technique for paying awards to a player.
BACKGROUND OF THE INVENTION
[0002] A very popular slot machine is called the “Wheel of Fortune”™. The Wheel of Fortune has three rotating reels for displaying symbols in a main game and, upon the reels displaying a certain combination of symbols, a large wheel spins. The large wheel has printed on it various payout awards, and the wheel randomly stops at a certain position to award the player the payout for that wheel position.
[0003] The Wheel of Fortune slot machine appeals to players due to the added excitement of a spinning wheel. What is desirable is a gaming technique that adds further excitement to increase player appeal.
SUMMARY
[0004] Various embodiments of games having payout wheels are described herein. In one embodiment, in a main or primary game, a plurality of reels displays combinations of symbols that signify instant awards, no awards, or the activation of a secondary game. The secondary game, forming part of the gaming system, consists of a plurality of wheels that provide special awards upon the display of a predetermined combination of symbols on the reels in the primary game.
[0005] In one embodiment, the plurality of wheels consists of a first wheel having relatively low payout awards associated with each position on the first wheel. The first wheel is spun and stopped to identify an award. At least one of the positions identifies that the award is to come from a second wheel, which has higher payout awards associated with each position on the second wheel. The second wheel is then spun and stopped to identify an award. There may also be a third wheel having award amounts higher than those on the second wheel, where the third wheel is activated upon a certain position on the second wheel being selected.
[0006] In one embodiment, the third wheel has a position which, when randomly selected, awards a player a jackpot value.
[0007] The awards provided by the wheels may be in addition to any award provided by the primary game that initiated the secondary game.
[0008] In one embodiment, only one wheel is spun at a time. In one embodiment, the wheels are concentric. Any number of wheels may be used.
[0009] The primary game may be any type of game, including those games displaying cards. The invention may be implemented as a video game, or use motor driven reels and wheels, or use a combination of motor driven reels or wheels and a video display of reels or wheels.
[0010] The invention is applicable to any type of gaming system, such as an on-line system using the Internet, a stand-alone gaming machine, or linked gaming machines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a perspective view of a video gaming machine which may incorporate software to carry out the present invention.
[0012] [0012]FIG. 2 illustrates basic hardware components in a conventional video gaming machine, where the program stored in the program memory carries out the particular game.
[0013] [0013]FIG. 3 is a flowchart illustrating the steps for carrying out one embodiment of the present invention.
[0014] [0014]FIGS. 4 and 5 illustrate sample displays on a CRT screen or other type of screen for an on-line gaming system, or a stand-alone gaming machine, or a linked gaming machine.
[0015] [0015]FIG. 6 illustrates an electromechanical reel and wheel assembly that can be used instead of, or in combination with, a gaming system using a video screen.
[0016] [0016]FIG. 7 illustrates a paytable.
[0017] [0017]FIGS. 8, 9, and 10 illustrate other displays of the bonus selectors.
DETAILED DESCRIPTION
[0018] Elements in the various figures identified with the same numerals may be identical and will not be redundantly described.
[0019] Although the present invention may be carried out on any type of computer platform, such as a stand-alone gaming machine, linked-gaming machines, or an on-line gaming system, where a user may interact with a remote server on a conventional personal computer to play the game described herein, the game will be described with respect to a stand-alone gaming machine.
[0020] [0020]FIG. 1 illustrates a video type gaming machine 10 having a video screen 12 , a coin input 14 , and control inputs 16 , such as buttons. Instead of buttons, a keyboard or touch screen may be used. For on-line gaming system, the display device would be a conventional monitor connected to the user's home computer.
[0021] [0021]FIG. 2 illustrates the hardware functional blocks in a conventional gaming machine. A program memory 18 contains computer instructions for allowing a processor 22 to carry out the various steps of the game. The hardware of FIG. 2 may be conventional and need not be described in detail. Processor 22 may be any type of microprocessor or any other device used to carry out a routine. A conventional gaming machine may be programmed to carry out the inventive game by changing the program in the machine's memory. For an on-line gaming system, the program may simply be downloaded into the user's home computer.
[0022] A typical stand-alone gaming machine also has a money detector 24 , control inputs 16 , an award table memory 26 , an award mechanism 28 such as a coin hopper or means to provide a code on tickets or a magnetic card, a display controller 30 , and a display screen 12 . The award table memory 26 associates the final positions on the reels and wheels in the machine with a monetary amount to be paid to the player. In an on-line system, the various control and memory functions would be carried out using shared resources in one or more computers. The display controller 30 receives relatively simply commands from processor 22 and converts the commands into complex pixel displays on screen 12 .
[0023] Operation of one embodiment of the present invention will be described with respect to the flowchart of FIG. 3 and the sample displays of FIGS. 4 and 5.
[0024] In step 1 of FIG. 3, the game is initiated by any known technique such as by pressing a button, touching a display screen, pulling a handle, depositing money, depositing coded instruments, clicking a mouse, or by any other means. The initiation of the game causes the three reels 40 in FIG. 4 to spin (either physically or on a video screen) and randomly stop on three positions across a payline (step 2 ). There may be multiple paylines. The three symbols may constitute losing symbols or winning symbols, where the winning symbols provide an instant award. The three symbols may also be a combination of certain special symbols, such as shown in FIG. 4 by the “Triple Deal”™ symbols being displayed, in which case the bonus wheels 44 are activated as part of a secondary game. Step 3 illustrates the decision of whether the symbol combination on the reels 40 spin the bonus wheels 44 . If the symbol combination does not spin bonus wheels 44 , the process goes to step 4 , where an award, if any, is paid to the player, and the game is ended (step 5 ).
[0025] If the special symbol combination appears across the payline (as shown in FIG. 4) to activate the bonus wheels 44 , the game proceeds to step 6 , where the first wheel 46 is spun. In the embodiment shown in FIG. 4, the first wheel 46 has relatively low payouts a identified around its periphery. In one embodiment, the numbers around the wheel identify a multiplication of the total bet for that game. For example, if three coins are bet, and the first wheel 46 identifies that the award is “ 4 ,” the bonus payout will be twelve coins.
[0026] After the first wheel 46 has been spun and stopped, if the indicator 48 does not indicate an award value but indicates a down-arrow 49 pointing toward the second wheel 50 (step 7 ), as shown in FIG. 4, the second wheel spins and randomly stops (step 8 ). The second wheel 50 has higher payout indicators on its periphery and, in one embodiment, these payout indicators are a multiple of ten times the payout indicators on the first wheel 46 . An award to the player identified by the second wheel 50 is then paid out unless a down-arrow position on the second wheel 50 is selected (step 9 ), as shown in FIG. 5. In such a case, the third wheel 52 is spun and randomly stopped (step 10 ). The third wheel 52 , in the embodiment shown in FIG. 5, has award values that are a hundred times as great as the award values on the first wheel 46 . If the stop position of the third wheel 52 is also a down-arrow (step 11 ), shown in FIG. 5, then a jackpot is awarded to the player (step 12 ).
[0027] There may be any number of down-arrows 49 on the wheels, and the award amounts may be any amount. Typically, the award amounts will be progressively higher with each successive wheel.
[0028] In addition to the bonus wheel amounts, the special symbol combination on the reels 40 that gives rise to the activation of the bonus wheels 44 may also pay instant award.
[0029] The process of FIG. 3 is carried out by the instructions in program memory 18 (RAM or ROM) in combination with processor 22 .
[0030] As would be conventional, the various control inputs shown in FIG. 4, such as Bet One, Spin Reels, Bet Max, Cash Out, and Payout Table (which displays the payout table on the video screen), may be activated by using either a mouse, a touch screen, or physical buttons. FIG. 4 also shows a bill insert slot 56 that may be either virtual or actual.
[0031] By adjusting the award amounts and the number of down-arrows 49 on the bonus wheels 44 , the probabilities of obtaining the various awards are easily adjustable.
[0032] Any number of bonus wheels 44 may be used, such as two, three, four, or more, and any configuration of the wheels may be used. For example, the wheels may be separate instead of concentric. Further, the wheels 44 may be in other forms, such as numeric displays on reels.
[0033] [0033]FIG. 6 illustrates an electromechanical version of the game where, instead of the game being completely carried out in software and displayed on a video screen, electric motors, such as stepper motors 62 and 63 (among others not illustrated), rotate the reels and bonus wheels 68 . The operation of the machine is otherwise identical to that described with respect to FIGS. 3 - 5 . The position of the reels 66 and wheels 68 may be predetermined by the program software, and the reels and wheels may be spun so as to achieve the predetermined outcome. Since the angular positions of stepper motors are easily determined by the number of pulses provided to the stepper motors, the positions of the reels 66 and wheels 68 are easily determined using conventional techniques.
[0034] [0034]FIG. 7 is an example of a payout table that may be displayed on the display glass of a gaming machine and stored in the paytable ROM. The symbol combinations are shown in the left column, and the payouts per coin bet are in the remaining columns. Note that the spinning of the bonus wheels, using the paytable of FIG. 7, is only activated upon the outcome of the AAA (e.g., Triple-Deal™) symbol combination with the maximum 3-coin wager to encourage a maximum bet. Of course, the activation of the bonus wheels may be set for any game outcome.
[0035] FIGS. 8 - 10 are examples of other displays that embody the concept of the present invention. In FIG. 8, the complete bonus wheels are visible, with the jackpot symbolized in the center.
[0036] [0036]FIG. 9 illustrates the various bonus levels in non-circular areas. The bonus values are shown in spaces representing honeycomb cells, and a bee randomly lands on a space in the appropriate level. If the bee lands on a bonus value, that bonus is received. If the bee lands on an arrow, the next level is activated.
[0037] [0037]FIG. 10 illustrates the bonus levels as rectangular rings, where a space in an appropriate level is randomly highlighted. If a bonus value space is highlighted, that bonus is received. If an arrow is highlighted, the next level is activated. The jackpot amount is displayed in the middle of the rings. Many other types of displays are suitable.
[0038] If the gaming concepts described herein are implemented in an on-line gaming system, the various positions of the reels and the wheels will be typically determined by a remote server, and the award will be paid to, for example, a player's account. The jackpot may be fixed or progressive. The game software may reside on any tangible medium, such as a CD ROM or a diskette, or may be transmitted over the Internet or via radio waves.
[0039] Additionally, the game may be carried out by a series of linked gaming machines, where the jackpot is progressive and common to all the gaming machines that are linked to the system.
[0040] While particular embodiments have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit and scope of this invention.
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Various embodiments of games having payout wheels are described herein. In one embodiment, in a main or primary game, a plurality of reels displays a combination of symbols. A second game forming part of the gaming system consists of a plurality of wheels that are initiated upon the display of a predetermined combination of symbols on the reels in the primary game. At least one outcome of a first wheel indicates that the payout will be decided by an additional wheel, having higher payouts than the first wheel. The invention may be implemented using video techniques or electromechanical techniques.
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SUMMARY OF THE INVENTION
The object of the present invention is a new class of imidazopyridine compounds having an interesting pharmacological activity.
More precisely, the compounds of the invention have the following structural formula: ##STR2## wherein R represents a hydrogen atoms, an alkyl radical of 1 to 3 carbon atoms, a methoxy group or a halogen atom,
R 1 represents a hydrogen atom, an alkyl radical of 1 to 3 carbon atoms,
n represents an integer of 1 to 10,
X represents a pharmaceutically acceptable ion.
The abovementioned compounds (I) possess skeletal muscle paralysing activity, which develops through the block of nervous impulse transmission at the level of the skeletal neuromuscular junction.
BACKGROUND OF THE INVENTION
Drugs with this property are classified, either as blockers of competitive type, if they compete with ACh on cholinergic receptors situated on the post-junctional membrane, or as blockers of depolarizing type, if the neuromuscular block is preceded by depolarization of the membrane. Moreover, agents provided with a combined competitive and depolarizing action are known, even if scarcerly used in therapy.
Drugs provided with skeletal muscle paralysing activity are clinically used, especially in anaesthesiology.
Skeletal muscle paralysing agents of the depolarizing type are mainly provided with fast starting and shortly lasting action. That makes them suitable for many therapeutic uses, even if it is known they may show serious complications, such as arrhythmias, cardiac arrest and, frequently, post-surgery muscular pains, just because of their mechanism of action, which causes muscular fasciculation before the effect of neuromuscular block starts.
The skeletal paralysing agenst of competitive type do not show the unwanted side effects, which may arise when using depolarizing blocking agents, but they are characterized by a slow onset and a long lasting duration of action. Moreover, they could induce unwanted side effects, such as release of histamine, ganglionic block, muscarinic receptor block (mainly, cardiac receptors) and inhibition of the norepinephrine reuptake; which effects could also induce relevant interference with the autonomic control of circulation.
DETAILED DESCRIPTION OF THE INVENTION
It has now been found that the new compounds of formula (I) possess a competitive neuromuscular blocking activity, whose paralysing action promptly arises is short lasting and, at active doses, does not detectably interfere with the cardiovascular system.
The compounds of the present invention have been pharmacologically studied, using as a standard fazadinium bromide, i.e. 1,1-azabis 3-methyl-2-phenylimidazo 1,2-a pyridinium bromide, a known compound of the commerce, provided with a competitive skeletal muscle paralysing activity.
The neuromuscular blocking activity has been evaluated:
in vitro, using the phrenic-diaphragm preparation according to the method described by Bulbring E. (Brit. J. Pharmac. Chemother. 1, 38, 1946). The preparation, taken from male Sprague-Dawley rats weighing 200-250 g, was placed into a bath for isolated organs, thermostatically kept at 37° C. and containing a nutritional liquid oxygenated with 5% carboxygen. The phrenic nerve was stimulated by means of square wave impulses (12 per min., duration 0.5 msec., overmaximal voltage). All compounds under examination and the reference standard were added to the bath at cumulative concentrations and showed to be active. The dose-effect curve, determined for each of them, allowed to calculate the EC 50 or effective concentration able to reduce the muscular contraction of 50% (Table 1);
in vivo, using the sciatic-gastrocnemious preparation, substantially following the method described by Hughes R. (Br. J. Anaesth. 44, 27, 1972). Male Sprague-Dawley rats weighing 200-250 g, anaesthetized (urethane 1,2 g/kg i.p.) and submitted to forced ventilation, were treated. The sciatic nerve was stimulated at a rate of 6 impulses per min. by means of square waves and overmaximal voltage with a duration of 0.5 msec. The left carotid artery was incannulated for the continuous registration of arterial blood pressure and heart rate.
The compounds to be tested were administered by i.v. route at increasing doses, given at intervals of at least 30 min. from one to another and, in any case, after the effect of previous administration had completely exhausted.
All compounds under examination and the fazadinium bromide showed to be active, so that it was possible to draw for each of them the dose-effect curve that allowed to calculate the ED 50 (effective dose causing the 50% reduction of muscular contraction) listed in Table 2. In addition, the time of latence (the interval between the administration and the maximal effect) and that of complete recovery have been determined. The percentage variations of arterial blood pressure and heart rate at ED 50 on muscular contraction are reported in Table 2.
In addition to the study on rat, the compounds under examination were administered by i.v. route to seven-day-old chicks in order to observe what type of paralysis (flaccid or spastic) had been induced. All compounds under examination have caused flaccid paralysis, showing that their mechanism of action is of a non-depolarizing type.
Acute toxicity or LD 50 was determined in male Sprague-Dawley rats weighing 1.2 g/kg i.p. The compounds under examination were administered by i.v. route at different level doses (5 animals for each dose). The LD 50 were then calculated according to the method of Litchfield J. T. and Wilcoxon F. J. (J. Pharmac. Exp. Ther., 95, 99, 1949). The results obtained are reported in Table 3.
The compounds of the invention can be dissolved in suitable solvents making them suitable to the administration, which is generally performed by parenteral, intravenous or intramuscular route. The pharmaceutical compositions can be formulated in a way suitable to single or multiple dosage depending on their specific use.
TABLE 1______________________________________Neuromuscular blocking activity "in vitro".Compound EC.sub.50 (μM/l)______________________________________Example 10 31.4Example 9 28.9Example 11 12.9Example 2 11.9Example 12 115.2Example 4 28.7Example 8 13.6Example 3 14.3Example 7 15.4Example 5 14.7Example 1 15.0Fazadinium bromide 13.9______________________________________
TABLE 2______________________________________Neuromuscular blocking activity"in vivo" and cardiovascular effects Cardiovascular effectsNeuromuscular block Arterial Re- blood Heart ED.sub.50 Latence covery pressure rateCompound (μg/kg i.v.) (min.) (min.) Δ % Δ %______________________________________Example 10 4.0 2.8 14.0 -30 +28Example 9 3.3 2.1 7.0 -31 +25Example 11 2.1 2.3 8.8 -40 +42Example 2 1.9 2.2 9.2 -45 +22Example 12 5.6 2.6 12.2 -5.sup.(a) +6Example 4 5.0 1.3 6.2 -28 +1Example 8 1.3 2.1 7.7 -40 +68Example 3 1.6 1.2 5.0 -28 +40Example 7 3.0 1.5 9.8 -50 -8Example 5 1.9 1.5 6.4 -39 +26Example 1 3.0 2.2 7.9 -37 +28Fazadinium 1.0 1.5 6.6 -16 +30bromide______________________________________ .sup.(a) -24% at minimal active dose on muscular contraction.
TABLE 3______________________________________Acute toxicity in rat.Compound LD.sub.50 (μM/kg i.v.)______________________________________Example 10 8.8Example 9 3.2Example 11 3.1Example 2 2.7Example 12 9.7Example 4 4.3Example 8 2.0Example 3 2.0Example 7 6.0Example 5 2.6Example 1 3.9Fazadinium bromide 1.5______________________________________
The compounds of the present invention may be prepared by reacting under heating a bis-(2-pyridylamino)alkylene (IV) optionally substituted with an α-halo-acylbenzene (III), in a suitable polar solvent, particularly an alcohol with low boiling point, and then dehydrating in acid conditions the imidazopyridinium derivative so obtained.
Schematically the process may be indicated as follows: ##STR3## wherein R, R 1 , n and X have the above mentioned meanings.
The reaction for building the imidazolic ring usually is carried out at a temperature between 60° and 120° C. and in practice the intermediate compound II may not be isolated and the reaction may proceed until the formation of the final compound I.
The intermediate compounds II are new compounds themselves and show to be pharmacologically active.
EXAMPLE 1
1,1'-(1,6-Hexamethylene)bis[2-(4'-fluoro)phenyl]imidazo[1,2-a]pyridinium perchlorate
A mixture consisting of 2.0 g of 1,6-bis(2-pyridylamino)hexane and 3.24 g α-chloro-p.fluoroacetophenone and 60 ml of 96% ethyl alcohol is refluxed for 16 hours and then 4.0 ml of 70% perchloric acid is added thereto and the mixture is heated at the boiling point for 2 hours. Cooling at room temperature and filtration gives 2.45 g 1,1'-(1,6-hexamethylene)bis[2-(4'-fluoro)phenyl]imidazo[1,2-a]pyrdidinium perchlorate, which, after recrystallization from acetonitryle, melts at 262°-265° C.
Analysis: found: C=53.99%; H=4.62%; N=7.82%. C 32 H 30 F 2 N 4 .2ClO 4 - requires: C=54.32%; H=4.27%; N=7.92%.
EXAMPLE 2
1,1'-(1,8-Octamethylene)bis-2-phenylimidazo[1,2-a]piridinium perchlorate
The process is similar to that described in Example 1, starting from 1,8-bis(2-pyridylamino)octane and α-bromoacetophenone to obtain with a yield of 56%, 1,1-(1,8-octamethylene)bis-2-phenylimidazo[1,2-a]pyridinium perchlorate, which melts at 204°-205° C.
Analysis: found: C=57.64%; H=5.21%; N=7.84%; C 34 H 36 N 4 .2ClO 4 - requires: C=58.37%; H=5.19%; N=8.01%.
EXAMPLE 3
1,1'-(1,8-Octamethylene)bis(2-phenyl-3-methyl)imiadazo[1,2-a]pyridinium perchlorate
The process is similar to that described in Example 1, starting from 1,8-bis(2-pyridylamino)octane and α-bromopropiophenone to obtain, with a 30%, 1,1'-(1,8-octamethylene)bis(2-phenyl-3-methyl)imidazo-[1,2-a]pyridinium perchlorate, which melts at 203°-205° C.
Analysis: found: C=59.82%; H=5.41%; N=7.92%; C 36 H 40 H 4 .2ClO 4 - requires: C=59.42%; H=5.54%; N=7.70%.
EXAMPLE 4
1,1'-(1,4-Tetramethylene)bis(2-phenyl-3-methyl)imidazo[1,2-a]pyridinium perchlorate
The process is similar to that described in Example 1, starting from 1,4-bis(2-pyridylamino)butane and α-bromopropiophenone to obtain, with a 29% yield, 1,1'-(1,4-tetramethylene)bis(2-phenyl-3-methyl)imidazo[1,2-a]pyridinium perchlorate, which melts at 302°-304° C.
Analysis: found: C=56.95%; H=4.82%; N=8.12%; C 32 H 32 N 4 .2ClO 4 - requires: C=57.24%; H=4.80; N=8.34%.
EXAMPLE 5
1,1'-(1,6-Hexamethylene)bis[2-(4'-methoxy)phenyl]imidazo[1,2-a]pyridinium bromide monohydrate
A mixture consisting of 1.0 g of 1,6-bis(2-pyridylamino)hexane, 2.16 g of α-bromo-p.metoxyacetophenone and 30 ml of 96% ethyl alcohol is refluxed for 4 hours and then 2.0 ml of 47% bromidric acid are added and the mixture is heated at the boiling point for a further 2 hours. The solvent is evaporated and the residue suspended in water, adjusted to pH 7 by addition of sodium hydroxide and filtered to give 2.0 g of 1,1'-(1,6-hexamethylene)bis[2-(4'-methoxy)phenyl]imidazo[1,2-a]pyridinium bromide monohydrate -elting at 281°-283° C. and, after crystallization from water, at 282°-284° C.
Analysis: found: C=57.17%; H=5.21%; N=7.82% C 34 H 36 N 4 O 2 .2Br - .H 2 O requires: C=57.48%; H=5.39%; N=7.89%.
EXAMPLE 6
1,1'-(1,8-Octamethylene)bis-2-phenylimidazo[1,2-a]pyridinium bromide trihydrate
The process is similar to that described in Example 5, starting from 1,8-bis(2-pyridilamino)octane and α-bromoacetophenone to obtain, with a 55% yield, 1,1'-(1,8-octamethylene)bis-2-phenylimidazo[1,2-a]pyridinium bromide trihydrate, which melts at 100°-110° C.
Analysis: found: C=56.85%; H=5.76%; N=7.32%. C 34 H 36 N 4 .2Br - .3H 2 O requires: C=57.15%; H=5.92%; N=7.83%.
EXAMPLE 7
1,1'-(1,6-Hexamethylene)bis[2-(4-bromophenyl)]imidazo[1,2-a]pyridinium bromide
The process is similar to that described in Example 5, starting from 1,6-bis(2'-pyridylamino)hexane and α,p-dibromoacetophenone, to obtain, with a 45% yield, 1,1'-(1,6-hexamethylene)bis-[2-(4-bromophenyl)]imidazo[1,2-a]pyridinium bromide, melting at 268°-273° C.
Analysis: found: C=48.66%; H=3.66%; N=7.20%; C 32 H 30 Br 2 N 4 .2Br - .3H 2 O requires: C=48.66%; H=3.83%; N=7.09%.
EXAMPLE 8
1,1'-(1,6-Hexamethylene)bis(2-phenyl-3-methyl)imidazo[1,2-a]pyridinium perchlorate
A mixture consisting of 2 g of 1,6-bis(2-pyridylamino)hexane, 3.92 g of α-bromopropiophenone and 100 ml 96% ethyl alcohol, is refluxed for 60 hours. After evaporating the solvent, the residue is taken up with acetone and filtered to give 1,85 g of 1,1'-(1,6-hexamethylene)bis(2-phenyl-2-hydroxy-3-methyl-2,3-dihydro)imidazo[1,2-a]pyridinium bromide melting at 145°-150° C. (yield 36%). After crystallization from isopropanol/ethyl acetate the solid melts at 151°-154° C.
Grams 1.85 of 1,1'-(1,6-hexamethylene)bis(2-phenyl-2-hydroxy-3-methyl-2,3-dihydro)imidazo[1,2-a]pyridinium bromide are dissolved in 30 ml water.
After heating to boiling temperature, 20 ml 70% perchloric acid are added and it is refluxed for 30'. By cooling to room temperature and filtration of the solid precipitate, 1,13-(1,6-hexamethylene)bis(2-phenyl-3-methyl)imidazo[1,2-a]pyridinium perchlorate melting at 235°-240° C. is obtained with a 85% yield. After crystallization from 90% ethanol, the solid melts at 249°-250° C.
Analysis: found C=58.62%; H=5.07%; N=8.14% C 34 H 36 N 4 .2ClO 4 - requires: C=58.37%; H=5.19%; N=8.01%.
EXAMPLE 9
1,1'-(1,4-Tetramethylene)bis-2-phenylimidazo[1,2-a]pyridinium perchlorate
The process is similar to that described in Example 8, starting from 1,4-bis(2-pyridylamino)butane and α-bromoacetophenone to obtain at first, with a 34% yield, 1,1'-(1,4-tetramethylene)bis(2-hydroxy-2-phenyl-2,3-dihydro)imidazo[1,2-a]pyridinium bromide melting at 234°-236° C. and then, with a 87% yield, 1,1'-(1,4-tetramethylene)bis-2-phenylimidazo[1,2-a]pyridinium perchlorate melting at 275°-277° C. and, after crystallization from 70% ethyl alcohol, at 278°-279° C.
Analysis: found: C=55.09%; H=4.54%; N=8.35% C 30 H 28 N 4 .2ClO 4 - requires: C=56.00%; H=4.39%; N=8.71%.
EXAMPLE 10
1,1'-(1,2-Ethylene)bis-2-phenylimidazo[1,2-a]pyridinium perchlorate
The process id similar to that described in Example 8, starting from 1,2-bis(2-pyridylamino)ethane and α-bromoacetophenone to obtain at first, with a 30% yield, 1,1'-(1,2-ethylene)bis(2-hydroxy-2-phenyl-2,3-dihydro)imidazo[1,2-a]pyridinium bromide meltint at 246°-248° C. and then, with a 90% yield, 1,1'-(1,2-ethylene)bis-2-phenylimidazo[1,2-a]pyridinium perchlorate melting at 308°-310° C. and, after crystallization from water, at 312°-314° C.
Analysis: found; C=54.04%; H=3.84%; N=8.99% C 28 H 24 N 4 .2ClO 4 - requires: C=54.65%; H=3.93%; N=9.10%.
EXAMPLE 11
1,1'-(1,6-Hexamethylene)bis-2-phenylimidazo[1,2-a]pyridinium perchlorate
The process is similar to that described in Example 8, starting from 1,6-bis(2-pyridylamino)hexane and α-bromoacetophenone to obtain at first, with a 40% yield, 1,1'-(1,6-hexamethylene)bis(2-hydroxy-2-phenyl-2,3-dihydro)imidazo[1,2-a]pyridinium bromide, which by addition of sodium perchlorate in water it formes the corresponding perchlorate melting at 216°-225° C. and then, with a 90% yield, 1,1'-(1,6-hexamethylene)bis-2-phenylimidazo[1,2-a]pyridinium perchlorate melting at 222°-234° C. and, after crystallization from 90% ethyl alcohol, at 226°-228° C.
Analysis: found: C=57.29%; H=4.86%; N=8.29% C 32 H 32 N 4 .2ClO 4 - requires: C=57.23%; H=4.80%; N=8.34%.
EXAMPLE 12
1,1'-(1,2-Ethylene)bis(2-phenyl-3-methyl)imidazo[1,2-a]pyridinium perchlorate
The process is similar to that described in Example 8, starting from 1,2-bis(2-pyridylamino)ethane and α-bromopropiophenone to obtain at first 1,1'-(1,2-ethylene)bis(2-phenyl-2-hydroxy-3-methyl-2,3-dihydro)imidazo[1,2-a]pyridinium bromide and then 1,1'-(1,2-ethylene)bis(2-phenyl-3-methyl)imidazo[1,2-a]pyridinium perchlorate, which, after crystallization from 80% ethyl alcohol, melts at 310°-312° C.
Analysis: found: C=55.88%; H=4.50%, N=8.20%; C 30 H 28 N 4 .2ClO 4 - requires: C=56.00%; H=4.39%; N=8.71%.
EXAMPLE 13
1,1'-(1,6-Hexamethylene)bis(3-ethyl-2-phenyl)imidazo[1,2-a]pyridinium perchlorate
The process is similar to that described in Example 8, starting from 1,6-bis(2-pyridylamino)hexane and α-bromobutyrophenone to obtain at first 1,1'-(1,6-hexamethylene)bis(3-ethyl-2-phenyl-2-hydroxy-2,3-dihydro)imidazo[1,2-a]pyridinium bromide and then 1,1'-(1,6-hexamethylene)bis(3-ethyl-2-henyl)imidazo[1,2-a]pyridinium perchlorate melting at 235°-236° C.
Analysis: found: C=58.68%; H=5.50%; N=7.70%; C 36 H 40 N 4 .2ClO 4 - requires: C=59.42%; H=5.54%; N=7.70%.
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New imidazopyridine derivatives are described, having the following formula: ##STR1## wherein R represents a hydrogen atom, an alkyl radical of 1 to 3 carbon atoms, a methoxy group or a halogen atom,
R 1 represents a hydrogen atom, an alkyl radical of 1 to 3 carbon atoms,
n represents an integer of 1 to 10,
X represents a non-toxic pharmaceutically acceptable ion, which possess a skeletal muscle paralyzing activity.
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RELATED APPLICATION
This application relies for priority upon Korean Patent Application No. 2000-66830, filed on Nov. 10, 2000, the contents of which are herein incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor device and a method therefor, and more particularly, to a gate electrode structure with an improved profile, and a method for manufacturing the same.
2. Description of the Related Art
As the degree of integration in semiconductor memory devices increases, areas occupied by separate devices, for example, a transistor, are reduced. In the transistor, hot carriers are generated in a channel region due to a short channel effect according to the reduction in area. In order to solve problems associated with the hot carrier effects, a lightly doped drain and source (LDD) transistor, in which source and drain regions are formed after forming spacers on the sidewalls of the gate electrode of the transistor and the sidewalls of a capping layer, are provided. Here, the capping layer is an insulating film formed on the gate electrode to protect the gate electrode in subsequent processing steps.
In general, a polycide, a structure with a refractory metal silicide layer formed on top of the polysilicon gate, is used to form a gate electrode. Typically, a thermal process is used to decrease the resistance of the gate electrode after forming the capping layer and the gate electrode. However, the refractory metal silicide layer becomes much larger than the capping layer during thermal expansion due to a variation in the coefficients of thermal expansion between the two materials. Accordingly, the profile of the gate electrode structure is not vertical but sloped.
Recently, a self-aligned contact hole is formed between the gate electrodes and then filled with a conductive material. As the semiconductor device is highly integrated, the slope of the sidewall of the gate electrode decreases and a sidewall spacer becomes thinner. Accordingly, the possibility of shorts between a conductive layer formed in the self-aligned contact hole and the gate electrodes substantially increases.
In order to prevent such shorts between the gate electrodes and the conductive layer, there have been attempts to increase the thickness of the spacer. However, as the thickness of the spacer increases, the distance between the gate electrodes becomes smaller. Therefore, voids are generated when the space between the gate electrode structures is filled with an interlayer insulating layer. Subsequently, voids are filled with the conductive material and undesirably connected to the conductive layer formed in an adjacent self-aligned contact hole, resulting in device failure.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a gate electrode structure, in which the slope of the profile of the gate electrode structure increases.
Accordingly, to achieve the above object, after sequentially forming a gate electrode conductive layer, for example, a polycide formed of polysilicon and a refractory metal silicide layer, and an insulating layer to form a capping layer on a semiconductor substrate, a thermal process is performed on the semiconductor substrate. The capping layer and the gate electrode are then formed by patterning an insulating layer and a conductive layer.
In another embodiment, after forming the conductive layer for the gate electrode and the insulating layer for the capping layer, the capping layer is formed by patterning the insulating layer. The thermal process is performed on the semiconductor substrate including the conductive layer. Then, the gate electrode and the spacer are formed.
According to the above-mentioned method, it is possible to skip a thermal process between a process of patterning the gate electrode and a process of forming the spacer by performing a thermal process on the conductive layer before the patterning process for forming the gate electrode. Also, it is possible to prevent the slope of the profile of the gate electrode structure from being decreased by patterning the conductive layer for the gate electrode, which is already thermally expanded. Here, that the slope of the profile of the gate electrode structure becomes decreased may mean that the slope of the side surface of the gate electrode structure is less than 80° in a peripheral region and is less than 83° in a core region.
BRIEF DESCRIPTION OF THE DRAWING(S)
The above object and advantages of the present invention will become more apparent by describing in detail a preferred embodiment thereof with reference to the attached drawings in which:
FIGS. 1 through 3 illustrate a method of forming a gate electrode structure having an improved profile according to an embodiment of the present invention;
FIG. 4 illustrates a method of forming a gate electrode structure having an improved profile according to another embodiment of the present invention;
FIGS. 5A and 5B show profiles of a gate electrode structure manufactured according to a conventional technology;
FIGS. 6A and 6B show the profile of a gate electrode structure manufactured according to an embodiment of the present invention;
FIGS. 7A and 7B show the profile of a gate electrode structure manufactured according to another embodiment of the present invention; and
FIG. 8 shows the ranges of fluctuation of the critical dimensions (CD) of gate electrode structures formed according to a conventional technology and according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, an oxide film 12 for forming a gate insulating film, a polysilicon layer 14 , a tungsten silicide layer 16 that is one of refractory metal silicide layers, and a silicon nitride film 18 for forming a capping layer are formed on a semiconductor substrate 10 . It will be appreciated by a person skilled in the art that other silicide layers such as a cobalt silicide layer or a titanium silicide layer can be used instead of the tungsten silicide layer 16 . Metal oxide films such as a silicon oxide film, a silicon oxinitride film, an aluminum oxide film, or a tantalum oxide film can be used instead of the silicon nitride film 18 depending on process conditions.
After forming a silicon nitride film 18 , a thermal process can be performed on the semiconductor substrate 10 . The tungsten silicide layer 16 is expanded by the thermal process. A rapid thermal processing (RTP) or a furnace can be used for the thermal process.
In FIG. 2, a capping layer 18 a, gate electrodes 16 a and 14 a, and a gate oxide film 12 a are formed by sequentially patterning a silicon nitride film 18 , a tungsten silicide layer 16 , a polysilicon layer 14 , and a silicon oxide film 12 . During the above patterning process, the same mask can be used with respect to all the layers formed on the semiconductor substrate 10 .
In FIG. 3, spacers 20 are formed on the sidewalls of the gate electrodes 14 a and 16 a and the capping layer 18 a. A stacked structure of a gate oxide film, a gate electrode, and a capping layer and spacers are referred herein to as a gate electrode structure. Although not shown, any damage to the sidewall surfaces of the gate electrodes 14 a and 16 a and the capping layer 18 a can be cured by growing an oxide film in an oxygen atmosphere before forming the spacers 20 .
FIG. 4 shows another method of forming a gate electrode structure according to one embodiment of the present invention. After sequentially forming a silicon oxide film 52 , a polysilicon layer 54 , a refractory metal silicide layer 56 , and a silicon nitride film (not shown) on a semiconductor substrate 50 , a capping layer 58 is formed by patterning the silicon nitride film. The thermal process is performed after forming the capping layer 58 . A gate electrode (not shown) and a gate oxide film (not shown) are formed by sequentially patterning the refractory metal silicide layer 56 , the polysilicon layer 54 , and the silicon oxide film 52 using the capping layer 58 as a mask. As shown in FIG. 3, spacers (not shown) may be formed on the sidewalls of the gate electrode and the capping layer 58 .
The (sloped) profile of the sidewalls of the gate electrode manufactured according to the present invention and the profile of the gate electrode formed according to the conventional technologies are shown in FIGS. 5A, 5 B, 6 A, 6 B, 7 A, and 7 B. The gate electrodes and the capping layers shown in FIGS. 5A, 5 B, 6 A, 6 B, 7 A, 7 B, and 8 denote a gate electrode formed of a polysilicon layer of 800 Å and a tungsten silicide layer of 1000 Å, and a capping layer formed of a silicon nitride film of 1800 Å. They are thermally treated for approximately 15 seconds at approximately 1050° C.
FIGS. 5A, 6 A, and 7 A show the gate electrode and the capping layer formed in the peripheral region of the semiconductor integrated circuit. FIGS. 5B, 6 B, and 7 B show the gate electrode and the capping layer formed on the core region of the semiconductor integrated circuit.
In the peripheral region, an angle formed between the sidewall of the gate electrode and the semiconductor substrate is about 77° in the conventional technology. However, an angle formed between the sidewall of the gate electrode and the semiconductor substrate increases to 80° (in the first embodiment) and 84° (in the second embodiment) according to the present invention. In the core region, an angle formed between the sidewall of the gate electrode and the semiconductor substrate is about 82° in the conventional technology. However, an angle formed between the sidewall of the gate electrode and the semiconductor substrate is about 86° in accordance with the first and second embodiments of the present invention.
When the gate electrode is formed according to the present invention, as shown in FIG. 8, the range of fluctuation of the critical dimension (CD) of the gate electrode is 39 nm, which is less than 59 nm, which is the range of fluctuation of the CD of the gate electrode according to the conventional technologies. Therefore, it is possible to form the gate electrode having more stable operation characteristics with the present invention. In FIG. 8, the horizontal axis denotes a design CD of the gate electrode and the vertical axis denotes a delta CD, which shows the range of fluctuation.
Thus, it is possible to prevent the slope of the profile of the gate electrode from being decreased by patterning the already-heat-treated tungsten silicide layer 16 , i.e., which is thermal expanded, during the formation of the gate electrode. Therefore, the spacer formed on the sidewalls of the gate electrode structure can have a desired thickness. Accordingly, an insulating effect by the spacer is not reduced. Also, the range of fluctuation of the threshold value of the gate electrode is reduced. Accordingly, it is possible to form a gate electrode having stable operation characteristics.
Having illustrated and described the principles of our invention in a preferred embodiment thereof, it should be readily apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. We claim all modifications coming within the spirit and scope of the accompanying claims.
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A gate electrode, in which the slope of the profile of a gate electrode forming material layer, for example, a refractory metal silicide layer is prevented from being decreased due to thermal expansion by patterning a refractory metal silicide layer after performing a thermal process on a refractory metal silicide layer, thereby having a stable operation characteristic, and a method for manufacturing the same are provided.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National Stage of International Application No. PCT/EP2015/053577, filed Feb. 20, 2015 and which claims priority to German Application No. 10 2014 207 023.6 filed Apr. 11, 2014. The entire disclosure of each of the above listed applications is incorporated herein by reference.
FIELD
[0002] The invention relates to a motor vehicle vacuum pump having a pump housing surface, on which a noise absorption cap is mounted, said cap defining a noise damping volume.
BACKGROUND
[0003] As part of ever stricter regulations relating to environmental protection, motor vehicle manufacturers are being compelled to design engines to be efficient and to have a low consumption. An automatic start-stop system is already available in almost all vehicles. Moreover, there is increasingly the possibility of switching off the internal combustion engine while coasting.
[0004] With such switching concepts for the internal combustion engine, it is hardly possible to use a mechanical vacuum pump for servo assistance of the braking force. There is therefore a demand for electric vacuum pumps for modern applications. These vacuum pumps often run dry since it is also no longer possible to supply the vacuum pump with oil in a manner dependent on a running internal combustion engine.
[0005] The absence of the engine noise of the internal combustion engine brings the operating noise of the vacuum pumps to the fore in terms of what is audible. In order to minimize these operating noises, various measures are implemented in order to reduce structure borne noise and airborne noise.
[0006] The publication WO 2011/134448 A2 discloses a vacuum pump having a pump housing, in which pump at least one pump housing part is formed by a sandwich-type sheet metal material comprising two sheet metal layers, between which is arranged a plastic layer, by means of which the sheet metal layers are vibrationally decoupled from one another. The vacuum pump can comprise a muffler, which is formed from the sandwich-type sheet metal material. Vacuum pumps having noise absorption caps are known from PCT/DE2013/100370 (not a prior publication). In addition, a multifunctional decoupling element is arranged between the pump housing surface and the noise absorption cap, said cap performing a sealing function and, in this prior art, also a valve function in addition to a noise decoupling function.
[0007] The decoupling element serves to decouple the noise absorption cap acoustically, particularly in respect of vibrations and/or structure borne noise occurring during the operation of the motor vehicle vacuum pump. By virtue of the acoustic decoupling of the noise absorption cap brought about by means of the decoupling element, unwanted development of noise during the operation of the motor vehicle vacuum pump can be considerably reduced. The decoupling element also forms a seal between the pump housing surface and the noise absorption cap with respect to the environment of the motor vehicle vacuum pump. A separate seal between the pump housing surface and the noise absorption cap can thus be omitted.
[0008] However, it is not possible, using the measures of damping the airborne noise by means of the noise absorption cap and damping the structure borne noise by means of the decoupling element, for all the structure borne noise to be suppressed and, specifically, for the noise peaks at the resonant frequencies to be reduced.
[0009] It is an object of the invention to further optimize a motor vehicle vacuum pump having a pump housing surface, on which a noise absorption cap defining a noise damping volume is mounted, in respect of unwanted development of noise during the operation of the motor vehicle vacuum pump.
SUMMARY
[0010] The object is achieved by means of a motor vehicle vacuum pump having a pump housing surface, on which a noise absorption cap is mounted, said cap defining a noise damping volume, wherein a double-sided adhesive connector is arranged between the pump housing surface and the noise absorption cap, said adhesive connector performing both a sealing function and a connecting function between the pump housing surface and the noise absorption cap in addition to a noise decoupling function.
[0011] For simplicity of assembly, it is advantageous here that the double-sided adhesive connector ( 60 ) is formed integrally from a viscoelastic material.
[0012] The use of a double-sided adhesive connector ( 60 ) made from an acrylate has proven particularly advantageous here.
[0013] It is advantageous here that the double-sided adhesive connector is of annular design. In this case, it is not at all essential that the annular adhesive connector should follow the contour of the components to be connected, allowing the use of adhesive connectors of standard dimensions.
[0014] The double-sided adhesive connector is advantageously of almost circular design.
[0015] To increase the fastening area, it is advantageous that the noise absorption cap for the double-sided adhesive connector has surfaces for adhesive bonding and/or fastening lugs on the pump cover and on the noise absorption cap.
[0016] It is advantageous that the double-sided adhesive connector is embodied and arranged in such a way that the noise absorption cap is acoustically decoupled from the pump housing surface and, in this way, the structure borne noise can be minimized.
[0017] The embodiment in which the double-sided adhesive connector, the noise absorption cap and the pump housing surface differ in hardness in such a way that the noise absorption cap is substantially vibrationally decoupled from the pump housing surface and thus also compensates tolerances as regards deviations from the flatness of the surfaces to be joined is particularly advantageous.
DESCRIPTION OF THE DRAWINGS
[0018] Further advantages, features and details of the invention will become apparent from the following description, in which various illustrative embodiments are described in detail with reference to the drawing, in which:
[0019] FIG. 1 shows an exploded view of a noise absorption cap of a motor vehicle vacuum pump in the prior art;
[0020] FIG. 2 shows an illustration of a pump housing according to the invention with the noise absorption cap; and
[0021] FIG. 3 shows an illustration of a pump cover surface upon which the noise absorption cap is installed.
DETAILED DESCRIPTION
[0022] FIGS. 1 and 2 show part of a motor vehicle vacuum pump 1 according to the invention having a pump housing 3 . The pump housing 3 comprises a housing pot (not shown), which is screwed to a pump cover 5 . It is possible to integrate into the housing pot a suction connection, via which a working medium, e.g. a gaseous medium, such as air or carbon dioxide, is drawn into a working chamber in the interior of the pump housing 3 when the motor vehicle vacuum pump 1 is driven.
[0023] The motor vehicle vacuum pump 1 is embodied as a vane pump having one or more vanes and a rotor. The rotor is connected in terms of drive to an electric motor. The general construction and operation of a vane pump are described in the publication WO2011/134448 A2, for example.
[0024] The motor vehicle vacuum pump 1 driven by the electric motor is operated without lubricating oil. The motor vehicle vacuum pump 1 operated without lubricating oil and driven by electric motor is installed in a motor vehicle, which can comprise a further drive in addition to an internal combustion engine drive, e.g. an electric motor drive.
[0025] When the internal combustion engine drive is switched off, the motor vehicle vacuum pump 1 driven by the electric motor is operated in the motor vehicle in order to produce a reduced pressure, e.g. in a brake booster embodied as a vacuum-type booster.
[0026] With its side facing away from a pump housing surface 8 , the pump cover 5 defines the working chamber of the motor vehicle vacuum pump 1 . Provided in the pump housing surface 8 is a passage opening 10 , which allows a gaseous working medium to pass through from the working chamber of the motor vehicle vacuum pump 1 . The passage opening 10 is embodied as a slotted hole and has the form of a circular arc in plan view.
[0027] The pump cover 5 with the pump housing surface 8 has essentially the form of a circular disk, on which three fastening recesses 11 , 12 , 13 are formed radially on the outside. The fastening recesses 11 to 13 delimit through holes, through which fastening means can be passed.
[0028] The pump cover 5 is formed from an aluminum material. The aluminum material is preferably a spray-compacted aluminum material. The spray-compacted aluminum material preferably has a silicon component of more than fifteen percent and contains particles of hard material. The aluminum material is preferably in the form of an alloy which, in addition to silicon, can also contain other elements, such as iron or nickel. The particles of hard material are preferably formed by silicon carbide.
[0029] A decoupling element 20 and a noise absorption cap 30 are attached to the pump housing surface 8 of the pump cover 5 . The decoupling element 20 has substantially the same shape as the pump cover 5 but is formed from a different material than the pump cover 5 . Radially on the outside, three fastening lugs 21 , 22 , 23 are formed on the decoupling element 20 , said lugs, together with the fastening recesses 11 to 13 on the pump cover 5 , being used to fasten the noise absorption cap 30 of the decoupling element 20 and of the pump cover 5 on the pump housing pot (not shown). Flexible bushes are placed on the fastening lugs or, alternatively, are formed integrally, and surround the fastening means, namely the screws.
[0030] The decoupling element 20 separates the noise absorption cap 30 vibrationally from the pump cover 5 . For this purpose, the decoupling element 20 is formed in this example from a silicone rubber material which is relatively soft in comparison with the aluminum material from which the pump cover 5 is formed.
[0031] In addition to the noise decoupling function, the decoupling element 20 also performs a sealing function. The decoupling element 20 comprises a main body 25 , which has essentially the form of a circular disk. Two annular beads are formed radially on the outside on both sides of the main body 25 .
[0032] The decoupling element 20 furthermore performs a valve function. For this purpose, a valve 28 is integrated into the decoupling element 20 . The valve 28 is embodied as a duckbill valve and is connected integrally to the main body 25 of the decoupling element 20 . The duckbill of the valve 28 extends from the pump housing surface 8 into the interior of the noise absorption cap 30 .
[0033] Radially on the outside, the noise absorption cap 30 has a fastening flange with three fastening lugs 31 , 32 , 33 . The fastening lugs 31 to 33 are used for the passage of screws 35 , 36 , 37 , with the aid of which the noise absorption cap 30 , together with the decoupling element 20 and the pump cover 5 , can be fastened on the pump housing pot (not shown) of the pump housing 3 .
[0034] The noise absorption cap 30 is formed from a plastic material of a hardness different from the materials from which the pump cover 5 and the decoupling element 20 are formed.
[0035] Although the decoupling element 20 has bushes to receive the screws 35 , 36 , 37 , the screws transmit structure borne noise between the pump cover 5 and the noise absorption cap 30 .
[0036] FIG. 2 shows the solution according to the invention, which shows a connection between the two components, the pump cover 5 and the noise absorption cap 30 , with the aid of a viscoelastic adhesive connector 60 . In one illustrative embodiment, an acrylate material that offers double-sided adhesive bonding, of the kind that can be obtained under the brand name 3M-4959 F, is used. The acrylate adhesive core of the material forms a virtually inseparable unit with the two functional adhesive surfaces. Unlike conventional foam adhesive strips, the adhesive, which is viscoelastic throughout, forms a durable, stress-free composite structure. Moreover, the adhesive connectors are vibration-damping and, by virtue of their closed-cell structure, have a sealing effect.
[0037] By using the viscoelastic adhesive connector 60 , noise transmission by the screwed joint between the pump and the noise absorption cap is prevented. The structure borne noise, which propagates at about 250 Hz with the respective harmonic components based on the rotational frequency of the pump, is suppressed by the adhesive connector in an effective manner that is very specific to frequencies below 1000 Hz.
[0038] Here, the frequencies caused by the vane rotations of the vacuum pump are damped very specifically by 10 dB, while the overall spectrum of the structure borne noise is damped by 5 dB. The fact that it is precisely frequencies in the lower range which are successfully reduced results in a significant improvement in terms of the subjective noise level.
[0039] An optimum sealing function is achieved by adhesive bonding with the metallic or plastic substrate without the sealing element, the adhesive connector, needing to have additional grooves or structures. The metallic surface of the pump cover 5 is joined flat to the plastic surface of the noise absorption cap.
[0040] The adhesive connector is a disk shaped ring which follows the outer contour of the pump cover and of the noise absorption cap. In FIG. 2 , the adhesive connector is flush with the outer contour of the noise absorption cap and the circumferential rim 42 thereof. However, the adhesive connector can quite possibly be inserted and installed in such a way as to be set back. Because it is not absolutely necessary to follow the outer contour, only a sufficiently large joining surface being required, standard adhesive connectors with predetermined outside radii can be used.
[0041] FIG. 3 shows a pump cover surface 8 on which an adhesive connector is arranged, on the right with a border a and on the left with a flush edge. It can be seen that there is a higher degree of freedom in the design of the outer contour of the pump if the adhesive connector does not also have to be adapted to the contour.
[0042] In order to simplify assembly, a shallow groove, e.g. in the noise absorption cap in the surface of the circumferential rim, can be provided, allowing the adhesive connector to be positioned in a simple manner. For fastening, sealing and noise decoupling, it is not necessary for the pump cover 5 and the noise absorption cap 30 to have fastening lugs 21 , 31 etc. The pump cover and the noise absorption cap can be produced without these protrusions and thus occupy a reduced installation space.
[0043] In an alternative embodiment, use is made of fastening lugs and the shape of the adhesive connector is adapted in order to achieve a larger fastening surface.
[0044] An advantageous embodiment uses a circular ring about 3 mm thick composed of the abovementioned material.
[0045] It is entirely reasonable that person skilled in the art should interpret the term vacuum pump in a very wide sense, describing not only the production of a conventional vacuum but also the production of a reduced pressure that approaches a vacuum. The principle of the invention shown is not restricted to a reduced pressure to be achieved.
LIST OF REFERENCE SIGNS
[0000]
1 motor vehicle vacuum pump
3 pump housing
5 pump cover
8 pump housing surface
10 passage opening
11 fastening recess
12 fastening recess
13 fastening recess
20 decoupling element
21 fastening lug
22 fastening lug
23 fastening lug
25 main body
28 valve
30 noise absorption cap
31 fastening lug
32 fastening lug
33 fastening lug
35 screw
36 screw
37 screw
42 circumferential rim
60 adhesive connector
a spacing
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The invention relates to a motor vehicle vacuum pump having a pump housing surface, on which a noise absorption cap is mounted, said cap defining a noise damping volume.
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FIELD OF THE INVENTION
This invention relates to evaporative emission control systems for the fuel systems of internal combustion engine powered automotive vehicles, particularly to apparatus for confirming the integrity of an evaporative emission control system against leakage.
BACKGROUND
A typical evaporative emission control system in a modern automotive vehicle comprises a vapor collection canister that collects volatile fuel vapors generated in the headspace of the fuel tank by the volatilization of liquid fuel in the tank. During conditions conducive to purging, the evaporative emission space which is cooperatively defined by the tank headspace and the canister is purged to the engine intake manifold by means of a canister purge system that comprises a canister purge solenoid valve connected between the canister and the engine intake manifold and operated by an engine management computer. The canister purge solenoid valve is opened by a signal from the engine management computer in an amount that allows the intake manifold vacuum to draw volatile vapors from the canister for entrainment with the combustible mixture passing into the engine's combustion chamber space at a rate consistent with engine operation to provide both acceptable vehicle driveability and an acceptable level of exhaust emissions.
U.S. governmental regulations require that certain future automotive vehicles powered by internal combustion engines which operate on volatile fuels such as gasoline have their evaporative emission control systems equipped with on-board diagnostic capability for determining if a leak is present in the evaporative emission space. It has heretofore been proposed to make such a determination by temporarily creating a pressure condition in the evaporative emission space which is substantially different from the ambient atmospheric pressure, and then watching for a change in that substantially different pressure which is indicative of a leak.
Commonly owned U.S. Pat. No. 5,146,902 "Positive Pressure Canister Purge System Integrity Confirmation" discloses a system and method for making such a determination by pressurizing the evaporative emission space by creating a certain positive pressure therein (relative to ambient atmospheric pressure) and then watching for a drop in that pressure indicative of a leak. Leak integrity confirmation by positive pressurization of the evaporative emission space offers certain benefits over leak integrity confirmation by negative pressurization, as mentioned in the referenced patent.
Pending, allowed, commonly owned application Ser. No. 07/995,484 filed 23 Dec. 1992 discloses an arrangement and technique for measuring the effective orifice size of relatively small leakage from the evaporative emission space once the pressure has been brought substantially to a predetermined magnitude that is substantially different from ambient atmospheric pressure. Generally speaking, this involves the use of a reciprocating pump to create such pressure magnitude in the evaporative emission space and a switch that is responsive to reciprocation of the pump mechanism. More specifically, the pump comprises a movable wall that is reciprocated over a cycle which comprises an intake stroke and a compression stroke to create such pressure magnitude in the evaporative emission space. On an intake stroke, a charge of atmospheric air is drawn in an air pumping chamber space of the pump. On an ensuing compression stroke, the movable wall is urged by a mechanical spring to compress a charge of air so that a portion of the compressed air charge is forced into the evaporative emission space. On a following intake stroke, another charge of atmospheric air is created.
At the beginning of the integrity confirmation procedure, the pump reciprocates rapidly, seeking to build pressure toward a predetermined level. If a gross leak is present, the pump will be incapable of pressurizing the evaporative emission space to the predetermined level, and hence will keep reciprocating rapidly. Accordingly, continuing rapid reciprocation of the pump beyond a time by which the predetermined pressure should have been substantially reached will indicate the presence of a gross leak, and the evaporative emission control system may therefore be deemed to lack integrity.
The pressure which the pump strives to achieve is set essentially by its aforementioned mechanical spring. In the absence of a gross leak, the pressure will build toward the predetermined level, and the rate of reciprocation will correspondingly diminish. For a theoretical condition of zero leakage, the reciprocation will cease at a point where the spring is incapable of forcing any more air into the evaporative emission space.
Leaks smaller than a gross leak are detected in a manner that is capable of giving a measurement of the effective orifice size of leakage, and consequently the arrangement is capable of distinguishing between very small leakage which may be deemed acceptable and somewhat larger leakage which, although considered less than a gross leak, may nevertheless be deemed unacceptable. The ability to provide some measurement of the effective orifice size of leakage that is smaller than a gross leak, rather than just distinguishing between integrity and non-integrity, may be considered important for certain automotive vehicles, and in this regard the arrangement is especially advantageous since the means by which the measurement is obtained is accomplished by an integral component of the pump, rather than by a separate pressure sensor.
The means for obtaining the measurement comprises a switch which, as an integral component of the pump, is disposed to sense reciprocation of the pump mechanism. Such a switch may be a reed switch, an optical switch, or a Hall sensor, for example. The switch is used both to cause the pump mechanism to reciprocate at the end of a compression stroke and as an indication of how fast air is being pumped into the evaporative emission space. Since the rate of pump reciprocation will begin to decrease as the pressure begins to build, detection of the rate of switch operation can be used in the first instance to determine whether or not a gross leak is present. As explained above, a gross leak is indicated by failure of the rate of switch operation to fall below a certain frequency within a certain amount of time. In the absence of a gross leak, the frequency of switch operation provides a measurement of leakage that can be used to distinguish between integrity and non-integrity of the evaporative emission space even though the leakage has already been determined to be less than a gross leak. Once the evaporative emission space pressure has built substantially to the predetermined pressure, the switch's indication of a pump reciprocation rate at less than a certain frequency will indicate integrity of the evaporative emission space while indication of a greater frequency will indicate non-integrity.
The pump is also used to perform flow confirmation that would confirm the absence of blockage in the purge flow conduits.
SUMMARY OF THE INVENTION
The present invention relates to further improvements in the organization and arrangement of the pump.
The invention retains advantages of the earlier pump: by enabling integrity confirmation to be made while the engine is running; by enabling integrity confirmation to be made over a wide range of fuel tank fills between full and empty so that the procedure is for the most part independent of tank size and fill level; by providing a procedure that is largely independent of the particular type of volatile fuel being used; and by providing a reliable, cost-effective means for compliance with on-board diagnostic requirements for assuring leakage integrity of an evaporative emission control system.
Additionally, the invention provides the pump with novel internal valving for selectively communicating the air pumping chamber space, a first port leading to the evaporative emission space, and a second port leading to atmosphere. This novel arrangement employs fewer parts, and consequently offers opportunity for improved manufacturing economy and in-use reliability
The foregoing, along with additional features, advantages, and benefits of the invention, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a presently preferred embodiment of the invention according to the best mode contemplated at this time for carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general schematic diagram of an evaporative emission control system embodying principles of the present invention, including relevant portions of an automobile.
FIG. 2 is a longitudinal cross sectional view through one of the components of FIG. 1, by itself.
FIG. 3 is a fragmentary view of a portion of FIG. 3 showing an operative position different from that of FIG. 2.
FIG. 4 is a graph plot useful in appreciating certain principles of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an evaporative emission control (EEC) system 10 for an internal combustion engine powered automotive vehicle comprising in association with the vehicle's engine 12, fuel tank 14, and engine management computer 16, a conventional vapor collection canister (charcoal canister) 18, a canister purge solenoid (CPS) valve 20, and a leak detection pump (LDP) 24.
The headspace of fuel tank 14 is placed in fluid communication with an inlet port of canister 18 by means of a conduit 26 so that they cooperatively define an evaporative emission space within which fuel vapors generated from the volatilization of fuel in the tank are temporarily confined and collected until purged to an intake manifold 28 of engine 12. A second conduit 30 fluid-connects an outlet port of canister 18 with an inlet port of CPS valve 20, while a third conduit 32 fluid-connects an outlet port of CPS valve 20 with intake manifold 28. A fourth conduit 34 fluid-connects a vent port of canister 18 with a first port 46 of LDP 24. LDP 24 also has a second port 44 that communicates directly with atmosphere.
Engine management computer 16 receives a number of inputs (engine parameters) relevant to control of the engine and its associated systems, including EEC system 10. One electrical output port of the computer controls CPS valve 20 via an electrical connection 36, and another, leak detection pump 24 via an electrical connection 40.
LDP 24 has a vacuum inlet port 48 that is communicated by a conduit 50 with intake manifold 28, and an electrical outlet at which it provides a signal to computer 16 via an electrical connection 54.
While the engine is running, operation of LDP 24 is commanded from time to time by computer 16 as part of an occasional diagnostic procedure for confirming the integrity of EEC system 10 against leakage. During occurrences of such diagnostic procedure, computer 16 commands CPS valve 20 to close. At times of engine running other than during such occurrences of the diagnostic procedure, LDP 24 does not operate, and computer 16 selectively operates CPS valve 20 such that CPS valve 20 opens under conditions conducive to purging and closes under conditions not conducive to purging. Thus, during times of operation of the automotive vehicle, the canister purge function is performed in the usual manner for the particular vehicle and engine so long as the diagnostic procedure is not being performed. When the diagnostic procedure is being performed, the evaporative emission space is closed so that it can be pressurized by LDP 24.
Attention is now directed to details of LDP 24 with reference to FIG. 2. LDP 24 comprises a housing 56 composed of several parts assembled together, these parts preferably being suitable fuel-resistant plastic. Interior of the housing, a movable wall 58 divides housing 56 into a vacuum chamber space 60 and an air pumping chamber space 62. Movable wall 58 comprises a general circular diaphragm 64 that is flexible, but essentially non-stretchable, and that has an outer peripheral margin captured in a sealed manner between two of the housing parts. The generally circular base 66 of an insert 68 is held in assembly against a central region of a face of diaphragm 64 that is toward chamber space 60. A cylindrical shaft 70 projects centrally from base 66 into a cylindrical sleeve 72 formed in one of the housing parts. A mechanical spring 74 in the form of a helical metal coil is disposed in chamber space 60 in outward circumferentially bounding relation to shaft 70, and its axial ends are seated in respective seats formed in base 66 and that portion of the housing bounding sleeve 72. Spring 74 acts to urge movable wall 58 axially toward chamber space 62 while the coaction of shaft 70 with sleeve 72 serves to constrain motion of the central region of the movable wall to straight line motion along an imaginary axis 75. The position illustrated by FIG. 2 shows spring 74 forcing a central portion of a face of diaphragm 58 that is toward chamber space 62 against a stop 76, and this represents the position which the mechanism assumes when the LDP is not being operated.
Ports 44 and 46 selectively communicate with each other and with chamber space 62 by valve arrangements that comprise two one-way umbrella valves 84, 86, and a plunger valve 88. Housing 56 comprises a walled enclosure 90 directly below, and separated from, chamber space 62 by a wall 92 that is perpendicular to axis 75. Enclosure 90 may be considered to comprise a generally circular sidewall 94 extending downward from wall 92 and a somewhat dome-shaped end wall 96 forming the enclosure's bottom. Port 44 intercepts the side of the dome of wall 96 so as to be open to the interior of enclosure 90. Port 46 passes through sidewall 94 and continues on until it intercepts a circular wall 98 that extends downward from wall 92 coaxial with axis 75 but that lies radially inwardly of sidewall 94 and also stops short of end wall 96. Port 46 is open to the space surrounded by wall 98 and has no communication with the interior of enclosure 90 along that portion of its length that lies between walls 94 and 98.
A portion of wall 92 that is disposed radially outwardly of wall 98 relative to axis 75 provides a mounting for valve 84 that allows air to pass from port 44, through the interior of enclosure 90 between walls 94 and 98, and into chamber space 62 through one or more through-holes 87 in wall 92, but not in the opposite direction. FIG. 2 shows the normally closed condition of the umbrella-type valve 84, whose center is retentively held on wall 92, and the outer peripheral margin of which seals against wall 92 in outwardly spaced relation to the one or more through-holes 87 in the wall, thus closing these through-holes to flow.
Plunger valve 88 is the vent valve for the evaporative emission system, and it serves two purposes: one, it comprises a head 100 for selectively unseating from and seating on the otherwise open lower end of wall 98 constituting a valve seat, so as to allow and disallow atmospheric venting of the evaporative emission space via the canister vent port; and two, it comprises a stem 102 that provides a mounting for one-way valve 86. The mounting comprises providing stem 102 with a circular groove 104 that seats, and axially and radially locates, valve 86 to be coaxial with the stem. Valve 86 has a central through-hole 106 allowing it to be fitted onto stem 102 and seated in groove 104 in the manner shown and described.
Stop 76 is provided as the upper axial end of a cylindrical sleeve 108 that is integrally formed with, and extends coaxial to axis 75 through, wall 92 between the space circumferentially bounded by wall 98 and chamber space 62. It provides axial guidance for travel of plunger valve 88 by affording a close sliding fit with the upper end of stem 102. A second helical coil spring 110 acting against head 100 imparts an upward axial bias force on plunger valve 88 causing the rounded upper end of stem 102 to bear against the center of movable wall 58 in the condition depicted by FIG. 2. The force exerted by spring 110 is however insufficient relative to the opposing force of spring 74 to dislodge the center portion of movable wall 58 from stop 76 in the FIG. 2 condition; rather the force of spring 110 is selected to assure that when the central region of movable wall 58 has been displaced upwardly greater than a certain distance from stop 76, spring 110 will force the contemporaneous closure of the open lower end of wall 98 by valve head 100 and the positioning of valve 86 on the central region of wall 92 that is circumferentially bounded by wall 98. The fragmentary view of FIG. 3 shows the condition where such upward displacement of wall 58 has occurred.
The shapes of both dome 96 and head 100 provide seatings for the respective ends of spring 110. Head 100 is essentially a circular flange that radially overlaps the opening at the lower end of wall 98. For closing that end in a sufficiently sealed manner, an annular seal 112 is on the face of head 100 for sealing to the circular rim of wall 98.
The central region of wall 92 that is bounded by wall 98 is nominally thickened, but it contains an annular groove 114 that is axially open toward valve 86 and one or more through-holes 116 that extend axially from the groove to chamber space 62. The outer circular margin of valve 86 radially overlaps the I.D. of wall 98 so that in the FIG. 3 position, the valve is closing chamber space 62 from the space surrounded by wall 98.
A solenoid valve 118 is disposed atop housing 56, as appears in FIG. 2. Valve 118 is like that disclosed in Ser. No. 07/995,484 and comprises a solenoid that is connected via connection 40 with computer 16. In addition to vacuum inlet port 48, valve 118 comprises an atmospheric port (not shown) for communication with ambient atmosphere and an outlet port that communicates with chamber space 60 by means of an internal passageway that is schematically represented at 117.
In the position depicted by FIG. 2, the atmospheric port of valve 118 is communicated to chamber space 60, resulting in the latter being at atmospheric pressure. When the solenoid of valve 118 is energized, the atmospheric port is closed and the vacuum inlet port 48 opened, thereby communicating vacuum inlet port 48 to chamber space 60.
The LDP has two further components, namely a permanent magnet 124 and a reed switch 126. The two are mounted on the exterior of the housing wall on opposite sides of where the closed end of sleeve 72 protrudes. Shaft 70 is a ferromagnetic material, and in the position of FIG. 2, it is disposed below the magnet and reed switch where it does not interfere with the action of the magnet on the reed switch. However, as shaft 70 moves upwardly within sleeve 72, a point will be reached where it shunts sufficient magnetic flux from magnet 124, that reed switch 126 no longer remains under the influence of the magnet, and hence the reed switch switches from one state to another. Let it be assumed that the reed switch switches from open to closed at such switch point, being open for positions of shaft 70 below the switch point and closed for positions of shaft 70 above the switch point. This switch point is however significantly below the uppermost limit of travel of the shaft, such limit being defined in this particular embodiment by abutment of the upper end of shaft 70 with the closed end wall of sleeve 72. For all upward travel of shaft 70 above the switch point, reed switch 126 remains closed. When shaft 70 once again travels downwardly, reed switch 126 will revert to open upon the shaft reaching the switch point. Reed switch 126 is connected with an output terminal 52 so that the reed switch's state can be monitored by computer 16 via connection 40.
Sufficient detail of FIG. 2 having thus been described, the operation of the invention may now be explained. First computer 16 commands CPS valve 20 to be closed. It then energizes valve 118 causing intake manifold vacuum to be delivered through valve 118 to vacuum chamber space 60. For the typical magnitudes of intake manifold vacuum that exist when the engine is running, the area of movable wall 58 is sufficiently large in comparison to the force exerted by spring 74 that movable wall 58 is displaced upwardly, thereby reducing the volume of vacuum chamber space 60 in the process while simultaneously increasing the volume of air pumping chamber space 62. The upward displacement of movable wall 58 is limited by any suitable means of abutment and in this particular embodiment it is, as already mentioned, by abutment of the end of shaft 70 with the closed end wall of sleeve 72.
The motion of wall 58 away from stop 76 allows spring 110 to concurrently push plunger valve 88 upward so that after an initial upward displacement of wall 58, head 100 of plunger valve 88 closes the open end of wall 98 and valve 86 is positioned on wall 92 to function as a one-way valve for allowing flow out of chamber space 62, but not into it. The plunger valve's closure of the open lower end of wall 98 closes the atmospheric vent to the canister vent port. As the volume of air pumping chamber space 62 increases during the upward motion of movable wall 58, a certain pressure differential is created across one-way valve 84 resulting in the valve opening at a certain relatively small pressure differential to allow atmospheric air to pass through port 44 into chamber space 62. When a sufficient amount of ambient atmospheric air has been drawn into chamber space 62 to reduce the pressure differential across valve 84 to a level that is insufficient to maintain the valve open, the valve closes. At this time, air pumping chamber space 62 contains a charge of air that is substantially at ambient atmospheric pressure, i.e. atmospheric pressure less drop across valve 84.
Under typical operating conditions, the time required for the charge of atmospheric air to be created in air pumping chamber space 62 is well defined. This information is contained in computer 16 and is utilized by the computer to terminate the energization of valve 118 after a time that is sufficiently long enough, but not appreciably longer, to assure that for all anticipated operating conditions, chamber space 62 will be charged substantially to atmospheric pressure with movable wall 58 in its uppermost position of travel. The termination of the energization of solenoid valve 118 by computer 16 immediately causes vacuum chamber space 60 to be vented to atmosphere. The pressure in chamber space 60 now quickly returns to ambient atmospheric pressure, causing the net force acting on movable wall 58 to be essentially solely that of spring 74.
The spring force now displaces movable wall 58 downwardly compressing the air in chamber space 62. When the charge of air has been compressed sufficiently to create a certain pressure differential across one-way valve 86, the latter opens. Continued displacement of movable wall 58 by spring 74 forces some of the compressed air in chamber space 62 through port 46 and into the evaporative emission space via the canister vent port. Spring 110 is sufficiently strong to resist the force of the compressed air so that plunger valve 88 continues to prevent the atmospheric venting of the canister vent port.
When movable wall 58 has been displaced downwardly to a point where shaft 70 ceases to maintain reed switch 126 closed, the latter opens. The switch opening is immediately detected by computer 16 which immediately energizes solenoid 118 once again. The energizing of solenoid 118 now causes manifold vacuum to once again be applied to chamber space 60, reversing the motion of movable wall 58 from down to up. The downward motion of movable wall 58 between the position at which shaft 70 abuts the closed end wall of sleeve 72 and the position at which reed switch 126 switches from closed to open represents a compression stroke wherein a charge of air in chamber space 62 is compressed and a portion of the compressed charge is pumped into the evaporative emission space. Upward motion of movable wall 58 from a position at which reed switch 126 switches from open to closed to a position where the end of shaft 72 abuts the closed end of sleeve 70 represents an intake stroke. It is to be noted that switch 126 will open before movable wall 58 abuts the rounded end of the plunger valve stem, and in this way it is assured that the movable wall will not assume a position that one, prevents it from being intake-stroked when it is intended that the movable wall should continue to reciprocate after a compression stroke, and two, displaces the plunger valve from the FIG. 3 position.
At the beginning of a diagnostic procedure, the pressure in the evaporative emission space will be somewhere near atmospheric pressure, and therefore the time required for spring 74 to force a portion of the charge from chamber space 62 into the evaporative emission space will be relatively short. This means that movable wall 58 will execute a relatively rapid compression stroke once vacuum chamber 60 has been vented to atmosphere by valve 88. If a gross leak is present in the evaporative emission space, LDP 24 will be incapable of building pressure substantially to a predetermined level which is utilized in the procedure once the possibility of a gross leak has been eliminated. Hence, continued rapid reciprocation of movable wall 58 over a length of time that has been predetermined to be sufficient to provide for the pressure to build in the evaporative emission space substantially to the level at which a later part of the procedure is otherwise conducted, will indicate the existence of a gross leak, and the procedure may be terminated at this juncture. Thus, the frequency at which switch 126 operates is used in the first instance to determine whether or not a gross leak is present, such gross leak being indicated by continuing rapid actuation of the switch over such a predetermined length of time.
If no gross leak is present, the evaporative emission space pressure will build substantially to a predetermined magnitude, or target level, which is essentially a function of solely spring 74. In the theoretical case of an evaporative emission space which has zero leakage, a point will be reached where spring 74 is incapable of providing sufficient force to force any more compressed air into the evaporative emission space. Accordingly, switch 126 will cease switching when that occurs.
If, once the target pressure has been substantially reached, there is some leakage less than a gross leak, pump 24 will function to maintain pressure in the evaporative emission space by replenishing the losses due to the leakage. A rate at which the pump reciprocates is related to the size of the leak such that the larger the leak, the faster the pump reciprocates and the smaller the leak, the slower it reciprocates. The rate of reciprocation is detected by computer 16 by monitoring the rate at which switch 126 switches. The rate of switch actuation can provide a fairly accurate measurement of the effective orifice size of the leakage. Leakage that is greater than a predefined effective orifice size may be deemed unacceptable while a smaller leakage may be deemed acceptable. In this way, the integrity of the evaporative emission space may be either confirmed or denied, even for relatively small effective orifice sizes. At the end of the procedure, computer 16 shuts off LDP 24 and allows CPS valve 20 to re-open on subsequent command.
A lack of integrity may be due to any one or more of a number of reasons. For example, there may be leakage from fuel tank 14, canister 18, or any of the conduits 26, 30, and 34. Likewise, failure of CPS valve 20 to fully close during the procedure will also be a source of leakage and can be detected. Even though the mass of air that is pumped into the evaporative emission space will to some extent be an inverse function of the pressure in that space, the LDP may be deemed a positive displacement pump because of the fact that it reciprocates over a fairly well defined stroke.
FIG. 4 is a typical graph plot illustrating how the present invention can provide a measurement of leakage. The horizontal axis represents a range of effective leak diameters, and the vertical axis, a range of pulse durations. In the case of the pumps that have been described, pulse duration would be defined as the time between consecutive actuations of reed switch 126 from closed to open, but it can be defined in other ways that are substantially equivalent to this way or that provide substantially the same information. The graph plot contains four graphs each of which represents pulse duration as a function of leak diameter for a particular combination of three test conditions, such three conditions being fuel level in the tank, location of an intentionally created leak orifice, and the duration of the test. As one can see, the four graphs closely match each other, proving that a definite relationship exists for the invention to provide a reasonably accurate measurement of leakage, even down to sizes that have quite a small effective orifice diameter. This measurement capability enables the engine management computer, or any other on-board data recorder, to log results of individual tests and thereby create a test history that may be useful for various purposes. The memory of the computer may be used as an indicating means to log the test results. The automobile may also contain an indicating means that draws the attention of the driver to the test results, such an indicating means being an instrument panel display. If a diagnostic procedure indicates that the evaporative emission system has integrity, it may be deemed unnecessary for the result to be automatically displayed to the driver; in other words, automatic display of a test result may be given to the driver only in the event of an indication of non-integrity. A test result may be given in the form of an actual measurement and/or a simple indication of integrity or non-integrity.
Because of the ability of the LDP to provide measurement of the effective orifice size of leakage, it may be employed to measure the performance of CPS valve 20 and flow through the system at the end of the diagnostic procedure that has already been described herein. One way to accomplish this is for computer 16 to deliver a signal commanding a certain opening of CPS valve 20, thus creating what amounts to an intentionally introduced leak. If the CPS valve responds faithfully, the LDP will reciprocate at a rate corresponding substantially to the amount of CPS valve opening that has been commanded. If there is a discrepancy, it will be detected by the computer, and an appropriate indication may be given. If no discrepancy is detected, that is an indication that the CPS valve and the system are functioning properly.
While a presently preferred embodiment of the invention has been illustrated and described, it should be appreciated that principles are applicable to other embodiments that fall within the scope of the following claims. An example of such an embodiment could comprise an electric actuator to stroke the movable wall. Of course, any particular embodiment of the invention for a particular usage is designed in accordance with established engineering calculations and techniques, using materials suitable for the purpose.
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An on-board diagnostic system for an evaporative emission control system of an internal combustion engine powered vehicle employs a positive displacement reciprocating pump to create in evaporative emission space a pressure that differs significantly from ambient atmospheric pressure. The pump is powered by using engine intake manifold vacuum to force an intake stroke during which both an internal spring is increasingly compressed and a charge of ambient atmospheric air is created in an air pumping chamber space. Vacuum is then removed, and the spring relaxes to force a compression stroke wherein a portion of the air charge is forced into the evaporative emission space. The rate at which the pump reciprocates to alternately execute intake and compression strokes indicates the pressure and flow through a leak in the evaporative emission space. Detection of this rate serves as a measurement of leakage for the purpose of distinguishing integrity of the evaporative emission space from non-integrity. The disclosed pump has a novel arrangement of its internal valving that reduces the number of parts required in comparison to a previous pump.
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[0001] This is a continuation application of U.S. patent application Ser. No. 10/757,435, filed on Jan. 15, 2004, which claims the benefit of priority of provisional application Ser. No. 60/448,491, filed Feb. 21, 2003, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method and a network element for handling policy information in multiple network nodes storing subscriber specific information, e.g., PDF (Policy Control Functions or Policy Decision Functions, also abbreviated as PCF).
BACKGROUND OF THE INVENTION
[0003] As described above, the present invention relates to handling of policy information. Such a handling is necessary in case a user would like to establish a session (e.g., a multimedia session) in which for the establishment additional information are required. Such additional information could be, for example, services required for the session, addresses of particular servers necessary for the session, information regarding handling of the session or whether the user is entitled to use the corresponding services necessary for the session. Moreover, also charging and/or billing information can be included.
[0004] The handling of policy information is carried out in a Policy Control Function (PDF). This is a logical policy decision element that uses standard IP (Internet Protocol) mechanisms to implement policy in the IP media layer. The PDF makes decisions in regard to network based IP policy using policy rules, and communicates these decisions to a GGSN (Gateway GPRS Support Node, GPRS=General Packet Radio Service), which serves the UE (user entity) of the user/subscriber. In detail, the decisions are communicated to a Policy Enforcement Point (PEP) located in the GGSN. This is a logical entity that enforces policy decisions made by the PDF. Between the GGSN and the PDF, a so-called Go interface is defined. Further details on PDF and policy control over Go interface can be found in ETSI TS 29 207 V5.0.0 (2002-06), for example.
[0005] In the following, a session authorization mechanism carried out on establishing a session is described briefly.
[0006] When a UE wishes to establish a session, it sends a set-up request (e.g., SIP INVITE) to the P-CSCF. This set-up request indicates e.g., the media streams to be used. The P-CSCF sends the necessary information to the PDF which makes a decision on the request, i.e., authorizes the session or does not authorize the decision. This decision is included in a response called “authorization token” which is subsequently used by the PDF in order to identify the session and the media it has authorized.
[0007] The P-CSCF sends a corresponding response to the UE which includes a description of the negotiated media together with the authorization token from the PDF. After this, the UE issues a request (for example, a PDP context activation) to reserve the resources necessary to provide a required QoS (Quality of Service) for the media stream. In this request, the authentication token from the PDF provided via the PDF and Flow Id(s) (flow identifier(s)) identifying the flow(s) on the PDP context are included.
[0008] The GGSN receives the reservation request and sends a policy decision request to the PDF in order to determine if the resource request should be allowed to proceed. Included in this request are the authentication token and the Flow Id(s) provided by the UE. The PDF uses this authorization token and the Flow Id(s) in order to correlate the request for resources with the media authorization previously provided to the P-CSCF. After this, the PDF sends a decision to the GGSN. Then, the GGSN sends a response to the UE indicating that the resource reservation is complete. Thus, the session can be started.
[0009] As to the function of the Authorization Token and the Flow Id(s), it is noted that in 3GPP R5, the Authorization Token and Flow Id(s) are used as binding information. The Authorization Token is also used to derive the IP address of the PDF storing the policy information.
[0010] In 3GPP (Third Generation Partnership Project) R5 (Release 5), the PDF is part of a P-CSCF (Proxy Call Session Control Function). The P-CSCF is a network element providing session management services (e.g., telephony call control).
[0011] In the next release, namely 3GPP R6, separating the PDF from the P-CSCF will be studied. That is, in such an environment, the PDF is independent from the P-CSCF, as described in 3GPP TR 23.917V0.4.10 (2002-12), for example. Therefore, a plurality of PDFs may be arranged, in order to handle policies for different kinds of sessions, for example.
[0012] It is possible that in the future there is a N-M relation between the P-CSCF and the PDF, i.e., that there is a plurality of P-CSCF and a plurality of PDF related to each other. This N-M relation is already in 3GPP R5 between the GGSN and the PDF. For the P-CSCF, this means that it could send session information to many PDFs. This could be done either on session basis e.g. by using a simple round-robin mechanism. Or then the P-CSCF could consider the load of the PDFs and could send session information to the least loaded PDF. As an alternative, the P-CSCF could also send session information on UE basis, e.g. so that information on all sessions of a UE would be sent to the same PDF. And yet as another alternative, session information of roaming UEs could be sent to certain PDFs, whereas session information of home UEs would be sent to other PDFs.
[0013] It is possible that in the future, the P-CSCF is served by one PDF and one PDF serves many P-CSCFs (1 to N relation). In that case, when the UE is served by many P-CSCFs for different application sessions, the same problems as described above may occur.
[0014] As described above, the PDF derives policy information from the received session information. If session information of a UE may reside in multiple PDFs, requesting policy information becomes more complex.
SUMMARY OF THE INVENTION
[0015] Thus, the object underlying the present invention resides in providing a mechanism, by which in a system comprising a plurality of nodes storing specific subscriber information (e.g., PDFs) an easy handling of policy information is possible.
[0016] This object is solved by a method for establishing sessions in a network comprising a user entity, a network control node and a plurality of network nodes storing subscriber specific information, the method comprising the steps of receiving a session establishing request at the network control node, forwarding a policy request message from the network control node to each network node of the plurality of network nodes storing subscriber specific information which comprise policy information required for the session to be established, processing the policy request message to generate a policy decision message and sending the policy decision message to the network control node from each of the network nodes having received the policy request message, generating a single policy decision confirmation message based on the received policy decision messages in the network control node, and sending the single policy decision message to the user entity.
[0017] Thus, according to the invention, a network control element contacts a plurality of nodes storing subscriber specific information (e.g., PDFs). This network control element provides the contact with the user entity, such that only a single request message is required which includes policy information for the plurality of nodes. Likewise, only a single decision message is necessary which comprises all policy decisions of the plurality of nodes.
[0018] Hence, the handling of policy information from the viewpoint of the user entity is as simple as in the prior art, namely, only single messages are required although now a plurality of nodes are provided.
[0019] That is, although the structure comprising a plurality of nodes storing subscriber specific information (e.g., PDFs) is more complex that in the prior art according to which only one node is present, the handling of the policy information does not become complicated
[0020] The network control element may be itself a network node of the plurality of network nodes storing subscriber specific information. That is, one of the network nodes storing subscriber specific information (e.g., PDF) controls the other PDFs.
[0021] Alternatively, the network control element may be a network service element serving the user entity. For example, the network service element may be a GSGN.
[0022] If network control element may be itself a network node of the plurality of network nodes storing subscriber specific information, the network control element may be selected by network connection serving element serving the user entity. For example, a default network node storing subscriber specific information may be selected. That is, for example a GSGN selects the one PDF of a plurality of PDFs.
[0023] The single policy decision message may comprise an authorization token from each node storing subscriber specific information. That is, all necessary authorization tokens are sent in the single message, such that no multiple messages for conveying the authorization tokens are required.
[0024] When the user entity is located in a visited operator domain, the following steps may be carried out: inserting policy information into a session set-up protocol message, sending the session set-up protocol message to a network control element in the home domain of the user entity, forwarding the policy information to a home subscriber database node, extracting an address of a home node storing subscriber specific information of the user entity from the subscriber database node, creating home policy information based on the extracted address, and forwarding the home policy information to a network control element of the visited network.
[0025] In this way, also the situation can be handled that a subscriber is roaming. Namely, the necessary policy information are sent during a session set-up to a home subscriber database node, and a network control element of the visited network is provided with necessary information.
[0026] The policy information may comprise an authentication token in general, so that the created home policy information may comprises a home Authentication Token.
[0027] Furthermore, the network control element of the visited network may create a visited policy information. That is, when roaming, there might be two different kinds of policy information, namely home and visited policy information.
[0028] The home policy information may be inserted into another session set-up protocol message
[0029] The session set-up protocol used for the above-referenced session set-up may be a Session Initiation Protocol (SIP).
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 shows a block diagram illustrating the procedure according to a first embodiment of the invention
[0031] FIG. 2 shows a block diagram illustrating the procedure according to a second embodiment of the invention, and
[0032] FIG. 3 shows a signalling flow diagram illustrating the procedure according to a third embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] In the following, preferred embodiments are described by referring to the enclosed drawings.
[0034] As described in the foregoing, the present invention is directed to the case that a plurality of PDFs (as examples for nodes storing subscriber specific information) are present which are independent from the P-CSCF.
[0035] According to a preferred embodiment of the invention, the GGSN contacts only one PDF and this selected PDF then contacts other PDFs if information on all sessions of a UE is not sent to the same PDF.
[0036] This situation is illustrated in the block diagram shown in FIG. 1 . It is noted that FIG. 1 only shows the principle necessary for understanding the invention, so that network elements required for establishing a connection but which are not essential for describing the invention are omitted for simplifying the illustration.
[0037] In detail, FIG. 1 shows a network system in which a plurality of PDFs (PDF(A), PDF(B), PDF(C), PDF(D)) are provided. In a message A 1 , the UE requests set-up of a session. Included in this message are a plurality of Authorization Tokens for the multiple PDFs, and also Flow Id(s). The GGSN takes only one of the Authorization Tokens (e.g. first or last) and determines the IP address of the PDF with that. In the illustrated case, it is assumed that the GGSN takes only the Authorization Token for PDF(A). The GGSN does not determine the IP addresses of the other PDFs (i.e., PDF(B), PDF(C) and PDF(D
[0038] The GGSN then sends a COPS (Common Open Policy Service) Request message (indicated by A 2 in FIG. 2 ) to the selected PDF(A) with all the binding information (in particular, including all Authorization Tokens) sent by the UE to the GGSN. The PDF(A) takes the remaining Authorization Tokens and contacts the remaining PDFs in order to receive policy information from those. That is, in the case as illustrated in FIG. 1 , the PDF(A) contacts PDF(B), PDF(C) and PDF(D) in messages A 3 to A 5 , respectively, and receives the policy information in messages A 6 to A 8 , respectively
[0039] The remaining PDFs addresses of PDF(B), PDF(C) and PDF(D) can be configured in the PDF(A) or the PDF(A) can make a DNS query based on the PDF FQDN (Fully Qualified Domain Name). All the subsequent GGSN requests will be sent to the PDF(A) and PDF(A) will trigger the request to the remaining PDFs. All the subsequent decisions from the PDFs will be triggered by the PDF(A) to the GGSN. Also the PDF(A) will trigger all the GGSN reports regarding changes related to the IP flows (carried by the PDP context) to the remaining PDFs.
[0040] In the present case, the policy decision is included in a message A 9 sent from the selected PDF(A) to the GGSN. The GGSN sends the policy decision to the UE in message A 10 .
[0041] Hence, the handling of policy information in a system comprising a plurality of PDFs according to the first embodiment of the invention is uncomplicated. In particular, the UE does only have to send a single set-up request message in which all necessary Authorization Tokens are included. The GGSN does only have to contact one single PDF (i.e., PDF(A) which handles the policy information with respect to the other PDFs involved. The policy decision is again sent in a single message from the PDF(A) to the GGSN and finally to the UE. Thus, the procedure for obtaining a policy information is from the viewpoint of the UE almost the same as according to the prior art: it requires only a single message although a plurality of PDFs are involved.
[0042] According to a modification of the first embodiment, a default PDF is introduced. The default PDF IP address is configured to the GGSN access point basis. That is, the address of the default PDF is stored in the GGSN so that this address does not have to be derived from Authentication Tokens received from the UE, for example. The GGSN always contacts this default PDF which then contacts the correct PDFs in order to receive policy information from those. In this way, the load on the GGSN is reduced and only a single PDF has to perform contacting other PDFs
[0043] That is, in case of the situation as illustrated in FIG. 1 , PDF(A) could be such a default PDF. In this case, it is not necessary for the GGSN to derive the address of PDF(A) since it is already set as a default, and it is not necessary to process the corresponding Authentication Token in the GGSN, which reduces the operation load on the GGSN.
[0044] Alternatively to the above, according to a second embodiment of the present invention, the GGSN contacts the multiple PDFs. That is, it is possible for 3GPP R6 that the GGSN requests separate authorization decisions from the involved PDFs regarding the authorization of the IP flows associated with components from different application sessions carried by a single PDP context
[0045] This situation is illustrated in FIG. 2 . The system shown in FIG. 2 is similar to that shown in FIG. 1 except that the GGSN contacts the plurality of PDFs and not a selected PDF. The message B 1 by which the UE requests a session set-up is the same as the message A 1 .
[0046] In contrast to the first embodiment, the GGSN considers all of the available Authorization Tokens in the PDP context and determines if different PDFs are involved.
[0047] The GGSN makes a separate authorization request including the binding information (the related Authorization Token and Flow Id(s)) to each of the concerned PDFs. This is illustrated in FIG. 2 by the messages B 2 to B 5 , respectively. When the GGSN receives the authorization decisions from the PDFs (illustrated by messages B 6 to B 9 ), then it combines them into one authorization decision for the PDP context.
[0048] That is, the message B 10 containing the authorization decision sent to the UE is the same as the message A 10 shown in FIG. 1 .
[0049] Thus, according to the second embodiment, the GGSN handles contacting of the different PDFs. This reduces the load on the PDF, since, in contrast to the first embodiment, there is no selected PDF(A) or a default PDF which needs to comprise also a functionality of contacting the other PDFs.
[0050] According to the first and the second embodiment described above, it is assumed that the PDFs reside in the same operator domain. In 3GPP R5, the PDF may reside either in the visited operator domain or in the home operator domain (depending on the GGSN location). In the future, i.e., in 3GPP R6, if the PDF resides in the visited operator domain, it may want to communicate with the PDF of the home operator domain (to receive UE specific policies from the home operator domain).
[0051] Using the Authorization Token in order to determine the PDF of the home operator domain requires some changes to the current mechanism in case of roaming UEs (i.e. UEs using the P-CSCF in the visited operator domain). According to the prior art (as described in the introductory part of the present application), the PDF in the P-CSCF allocates the Authorization Token.
[0052] However, in the future, i.e., when P-CSCF and PDF are separated, the Authorization Token may have to be allocated also in the home operator domain (so that the PDF in the visited operator domain can contact the PDF in the home operator domain).
[0053] This situation is described in the following as a third embodiment. It is noted that the way how the different PDF(s) located in the visited operator domain are accessed by the GGSN itself or the selected PDF(A) is the same as in the first embodiment and the second embodiment. In the present third embodiment, the creation of Authentication Tokens is described which require access to a home domain PDF.
[0054] According to the third embodiment, a node in the home operator domain forwarding SIP messages (e.g. S-CSCF) inserts the Authorization Token into the SIP messages (e.g., INVITE when establishing a session). The Authorization Token includes the PDF FQDN (Fully Qualified Domain Name). This PDF, i.e., the PDF in the home domain, stores UE specific information. In contrast thereto, the PDF(s) in the visited operator domain stores only session based information. For a policy decision, information of both PDF(s) located in the home domain and PDF(s) located in the visited operator domain might be necessary.
[0055] If the S-CSCF includes the Authorization Token to SIP messages, the S-CSCF may get the PDF fully qualified domain name e.g. from the HSS as indicated in FIG. 3
[0056] FIG. 3 shows a principle structure how the Authentication Token is created. It is noted that only the network elements and the flow necessary for the invention are shown in order to simplify the illustration. The UE sends a SIP INVITE message to the P-CSCF of the visited operator domain. The P-CSCF forwards the INVITE message to the S-CSCF of the home domain. The S-CSCF further processes and forwards the session set-up (as indicated by the dotted arrow), in the following, however, only the creation of the authentication token is shown. The S-CSCF sends a SIP REQUEST message to the HSS of the subscriber (UE). The HSS responds with a the PDF FQDN. Hence, the S-CSCF knows the PDF FQDN and creates the Authentication Token of the home PDF (abbreviated as Auth Token (home) in FIG. 3 ) which includes the PDF FQDN. It is noted that also a plurality of Authentication Tokens (home) may be created in case a plurality of PDFs are provided in the home domain which contain relevant information for the session to be established by the particular subscriber.
[0057] Meanwhile, the S-CSCF receives a SIP ACK message during the remaining set-up of the session (as indicated by the dotted arrow). Thereafter, the S-CSCF inserts the Auth Token (home) into the SIP ACK message and forwards this to the P-CSCF in the visited operator domain. This P-CSCF also creates an Authentication Token for the visited operator domain (abbreviated as Auth Token (visited) in FIG. 3 ). It is noted that also a plurality of Auth Tokens (visited) may be created in case a plurality of PDFs in the visited operator domain are involved.
[0058] Finally, the P-CSCF inserts the created Auth Tokens (visited) into the SIP ACK messages and sends it to the UE. After this, the UE has received the necessary Authentication Tokens both of the visited and home domain such that it can start a session
[0059] As an alternative, if the Authorization Token is not used to determine the PDF in the home operator domain, the PDF in the visited operator domain could perform a UE identity analysis (e.g. IMSI analysis) in order to determine the PDF in the home operator domain
[0060] Thus according to the above embodiments, the GGSN can communicate with one PDF only and could receive policy information affecting an entity (e.g. a PDP context) from one network element (a selected PDF, a default PDF or the GGSN) only.
[0061] The above description and accompanying drawings only illustrate the present invention by way of example. Thus, the embodiment may vary within the scope of the attached claims.
[0062] For example, the PDF as described in the above embodiments is just an example for a node storing subscriber specific information in the home operator domain. HSS (Home Subscriber Server) is another example of such a node. That is, also the HSS could be provided in such a structure that different HSS servers are provided. In this case, the Authorization Token includes the HSS FQDN instead of the PDF FQDN.
[0063] Moreover, the GGSN is only an example for a network service element serving the user entity.
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The invention proposes a method for establishing sessions in a network comprising a user entity, a network control node and a plurality of network nodes storing subscriber specific information, the method comprising the steps of receiving a session establishing request at the network control node, forwarding a policy request message from the network control node to each network node of the plurality of network nodes storing subscriber specific information comprising policy information required for the session to be established, processing the policy request message to generate a policy decision message and sending the policy decision message to the network control node from each of the network nodes having received the policy request message, generating a single policy decision confirmation message based on the received policy decision messages in the network control node, and sending the single policy decision message to the user entity.
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FIELD OF THE INVENTION
This invention relates to a new heavy oil hydrocracking process using a multimetallic liquid catalyst in a slurry-bed, particularly an improvement of lightweight treatment of heavy oil in the petroleum processing technology. According to the present invention, a slurry-bed hydrocracking reactor and the highly dispersed multimetallic liquid catalyst are mainly applied during the process. A fixed-bed hydrotreating reactor is also used on line to enhance lightweight oil yield from heavy oil under normal pressure.
BACKGROUND OF THE INVENTION
In today's world, research on slurry-bed hydrocracking processes are very active. There are now more than ten such technologies that are in pilot test stage. Some of them have already had industrialized application. But, in these technologies, there exist numerous limitations and shortcomings. The following are some examples.
One example is the VEBA-Combi-Cracking (VCC) process developed in Germany. This process adopts red mud, i.e., a kind of solid material with iron content, and the fine coke powder of Bovey coal as a catalyst. In this technology, not only is the reaction pressure (30-75 Mpa) relatively high, but also a relatively large amount of catalyst, such as about 5% weight percent of raw materials, must be used.
A second example is the Micro-Cat technology developed by ExxonMobil. In this technology, phospho-molybdic acid and molybdenum naphthenate are used as catalyst. Although the dispersion rate and activity of the catalyst are high, this technology remains for now in an experimental scale (1 drum/day). A reason may be that the cost of catalyst is relatively high with low economic profit.
A third example is the HDH technology developed by the Venezuelan INTEVEP Company. This technology uses as a catalyst a kind of inexpensive natural ore that is a special local product currently in Venezuela after it is crushed and fined. Although the catalyst is inexpensive, it must be used in a very large amount (2-3 m %). The required separation system for solid matter of catalyst and non-converted bottom oil is relatively complex. Furthermore, the mineral ore is produced specially only in Venezuela.
Still another example is the Canadian CANMET process. The catalyst used in this process is FeSO 4 ·H 2 O with a relatively high dosage (1-5%). The desulfuration and denitrogenation rate of this process is not high, although it does appear to achieve the expected quality of products. There also exist some problems in the separation of catalyst and non-converted bottom oil.
A fifth example is the SOC technology developed by a Japanese company, Ashi Kasei Industrial Co. In this technology, the catalyst, consisting of highly dispersed superfine powder and transition metallic compound, is used with high reaction activity and good anticoking effects. But, this process requires a high reaction pressure (20-22 Mpa) and a relatively high investment cost in the facility.
There are other technologies currently available around the world, such as the Aurabon technology developed by the American UOP Company, the HC3 technology developed by Canada, etc. But, some of these technologies are only being tested on an experimental scale, some use too great a dosage of catalyst, some adopt a solid catalyst, and some use expensive catalysts or require high reaction pressures. In these prior processes, the catalyst used is a single catalyst or a mixture of catalysts. Most of the raw materials being processed using the above-discussed technologies were high sulfur-containing heavy oil. The applications of these prior technologies were also limited in processing low sulfur-containing heavy oil.
SUMMARY OF THE INVENTION
In order to avoid the shortcomings of the prior processes, the object of the present invention is to provide a new and improved heavy oil hydrocracking process using a multimetallic liquid catalyst in the slurry-bed.
In order to carry out the aims of this invention, the technical embodiment of this invention can be realized through the following methods:
According to the present invention, a heavy oil hydrocracking process using a multimetallic liquid catalyst in a slurry-bed reactor under normal (atmospheric) pressure is provided. A slurry-bed hydrocracking reactor charged with a multimetallic liquid catalyst and an online fixed-bed hydrotreating reactor are installed. An online mixer is used to make full mixture of feed oil with catalyst, followed by low-temperature sulfidation. The effluent out of the reactors is separated under a high-pressure or low-pressure separating system or using a conventional separating system. Vacuum gas oil is separated and recycled.
Particularly, the present invention provides a heavy oil hydrocracking process using multimetallic liquid catalyst in the slurry-bed reactor under normal pressure conditions. The feeds, namely heavy oil mixed with catalyst and hydrogen, come into the bottom of a slurry bed hydrocracking reactor. The effluent out of the top of the reactor enters a high-temperature and high-pressure separation system whereby the effluent is separated into vapor flow and liquid flow. Vapor flow enters an online fixed-bed hydrotreating reactor, while liquid flow enters a low-pressure separation system. The vapor flow out of the top of the low-pressure separation system is also directed into the online fixed bed hydrotreating reactor after being cooled. The effluent out of the fixed bed hydrotreating reactor is fed into a conventional separation system, such as vacuum distillation tower.
The high-pressure separation system of the present invention preferably includes a hot high-pressure separator and a cold high-pressure separator. The low-pressure separation system used in the present invention preferably includes a flash drum, a vacuum distillation tower, a low-pressure separator, and a cold low-pressure separator
The vacuum gas oil fractionated out of the vacuum distillation tower is returned, at least partially, to a slurry-bed hydrocracking reactor for further treatment.
The fixed-bed hydrotreating reactor is on line in the process of this invention. The hydrogen source comes from hot material flow of the slurry-bed hydrocracking reactor. The online mixer for mixing raw materials and catalyst is preferably a shear pump or a static mixer. In a particularly preferred embodiment, the shear pump is a shear pump with 2-7 levels.
A first portion of the vacuum gas oil fractionated out of the vacuum distillation tower in the low-pressure separation system is returned to the slurry-bed hydrocracking reactor. The other portion is returned to the slurry-bed hydrocracking reactor together with the slurry to enhance the yield of diesel oil.
According to the present invention, the hydrocracking reactor is a total feedback mixed reactor, and the slurry in the reactor is cycled continuously from a circulating pump to maintain a total feedback mixed state. The slurry typically comprises untreated residual oil, liquid catalyst, recycled bottoms, recycled vacuum gas oil and fresh hydrogen.
In carrying out the process of the present invention, the preferred reaction conditions of the slurry-bed hydrocracking reactor are about as follows:
reaction pressure: 8-12 Mpa,
reaction temperature: 420-460° C.,
total volume hourly space velocity: 0.8-1.4 h −1 ,
recycling ratio of bottom oil/fresh raw materials: 0.3-0.8,
dosage of catalyst based on metal: 50-2000 ppm,
ratio of hydrogen to fresh raw materials: 600-1000.
The preferred conditions of the online fixed-bed hydrotreating reactor are about as follows:
reaction temperature: 300-400° C.,
reaction pressure : a little less than the pressure of the hydrocracking reactor of suspension bed,
volume hourly space velocity: 1.0-2.0 h −1 , and,
ratio of hydrogen/oil: 300-1000.
In other words, the process of the present invention includes many technical innovations to provide a completely new and improved slurry-bed hydrocracking technology. The present invention uses a highly dispersed multimetallic liquid catalyst in a slurry-bed hydrocracking reactor, and it adopts on line a fixed-bed hydrotreating reactor so that the technology can solve persistent problems of processing residual oil including low sulfur petroleum as well as high sulfur petroleum. The process of this invention is especially effective to process at normal pressures residual oil having relatively high content of nitrogen and/or metal, a relatively high viscosity, a high acid number and/or a high residual coke content. The process of this invention is further characterized in adopting a slurry-bed hydrocracking reactor charged with multimetallic liquid catalyst and an online fixed-bed hydrotreating reactor. The process of this invention also uses an online mixer to effect thorough mixing and low-temperature sulfuration of the raw materials and catalyst The process of this invention is further characterized in adopting a high and low-pressure separation system and a conventional separation system for treating the effluent out of the reactor. The process of this invention also adopts the recycle technology for processing the vacuum gas oil. In the present process, the fully mixed and heated slurry is flowed into the bottom of a slurry-bed hydrocracking reactor, while the effluent flowing out of the top of the reactor is fed to a high-temperature and high-pressure separation system, where the effluent is separated after it enters the hot high-pressure separation reactor. The material flow in the vapor phase is fed into an online fixed-bed hydrotreating reactor, while the material flow in the liquid phase is fed to a low-pressure separation system. The material flow in liquid phase coming from the low-pressure separation system (excluding the bottom oil) is also fed into the online fixed-bed hydrotreating reactor. Then, the material flow, after being hydrogenated and treated through the fixed bed, is fed to the conventional separation system for separating into a variety of products. The high-pressure separation system preferably includes a hot high-pressure separator and a cold high-pressure separator. The low-pressure separation system preferably includes a flash drum, a vacuum distillation tower, a low-pressure separator, and a cold low-pressure separator. The conventional separation system preferably includes a vacuum distillation tower. The vacuum gas oil fractionated out of the vacuum distillation tower is at least partially returned to the slurry-bed hydrocracking reactor for further treatment.
In order to achieve the above-mentioned aims, the process of this invention was designed such that the fixed-bed hydrotreating reactor would be used throughout the processing. The preferred used hydrogen source for the present invention comes from hot material flow of the slurry-bed hydrocracking reactor. The mixer for mixing raw materials and catalyst is preferably a multistage shear pump or a static mixer. The multistage shear pump may advantageously be a shear pump with 2-7 levels. A first part of the vacuum gas oil fractionated out of the vacuum distillation tower in the low-pressure separation system is preferably returned to the slurry-bed hydrocracking reactor. The other part preferably is returned to the slurry-bed hydrocracking reactor together with the fresh feed. The slurry in the slurry reactor is recycled continuously from a recirculating pump to maintain a total feedback mixed state. The slurry may typically contain untreated residual oil, liquid catalyst, recycled bottoms, recycled vacuum gas oil and fresh hydrogen.
In the present invention, the reaction conditions of the slurry-bed hydrocracking reactor are preferably as follows: the reaction pressure is about 8-12 Mpa; the reaction temperature ranges from about 420-460° C.; the total volume hourly space velocity is about 0.8-1.4 h −1 ; the recycling ratio of bottom oil over fresh feed oil is about 0.3-0.8; the dosage of catalyst used relative to total weight of metal is about 50-2000 ppm; and the ratio of hydrogen to fresh feed oil is about 600-1000. The conditions of the online fixed-bed hydrocracking reactor are preferably as follows: the reaction temperature is about 300-400° C.; the pressure is preferably just a little below the pressure of the slurry-bed hydrocracking reactor; the volume hourly space velocity is about 1.0-2.0 h −1 ; and the ratio of hydrogen over feed oil is about 300-1000. The catalyst used by the slurry-bed hydrocracking reactor is preferably a highly dispersed multimetallic liquid catalyst. The principal components of the multimetallic liquid catalysts according to the present invention are the multimetallic salts. The catalyst used in the fixed-bed hydrotreating reactor may be catalyst 3936 or RN-2 hydrocracking catalyst, or similar catalysts as are commonly used in the industry.
There are numerous differences between the hydrocracking technology of the present invention and the several hydrocracking technologies of the prior art processes. Some of those key differences include the following:
(1) The slurry-bed hydrocracking reactor in the present invention applies highly dispersed (micron or nm) multimetallic liquid catalyst. The effective metal components of the catalyst include nickel, iron, molybdenum, manganese, cobalt and the like. Because a major part of the metal components of the catalyst is recovered from the industrial waste materials, the cost is thereby greatly reduced. The multimetallic liquid catalysts of the present invention differ fundamentally from the solid powder catalysts or the dispersed catalysts with small amounts of other components which are commonly used in the world.
(2) Another feature of the present invention is the adoption of a novel catalyst dispersion and low-temperature sulfuration technology. In the present invention, a 2-4 level shear pump is preferably used in the flow pipeline for raw oil and catalyst which are thereby dispersed and mixed at about 2000-5000 turns/m. Thereafter, the sulfuration of catalyst in the mixed materials is completed using gas containing hydrogen sulfide at the temperature of about 100-180° C.
(3) In still another difference from the prior processes, the present invention adopts a circulating cracking route with vacuum gas oil and bottom oil. The main products of the process are naphtha and diesel oil as well as a small amount of bottom oil.
(4) As the present invention adopts a total return mixed cracking reactor, only a relatively small amount of coke formation results. The temperature of the reactor is very even and easy to control so that it simplifies the reactor operation and temperature control. Additionally, this invention adopts a high-temperature, high-pressure online hydrotreating reactor that not only efficiently makes full use of existing reaction temperature and pressure, but also makes products of very high quality.
In comparison with the prior processes, the present invention has the following additional advantages:
(1) The multimetallic liquid catalyst used in the process of the present invention is highly dispersed resulting in surprisingly improved performance. The particle size of the catalyst is small (on the order of about 0.1-5 micron) with high activity, therefore only a very small dosage (>0.1%) is needed. In addition, as many metal components in the catalyst come from industrial waste materials, the cost of this catalyst is very low.
(2) Due to the high activity of the multimetallic liquid catalyst of the present invention, the reaction temperature is relatively high (e.g., about 430-460° C.) with a high cracking conversion rate (80-90%) and with little coking formation (<1%).
(3) Low reaction pressure can be used, (e.g., hydrogen partial pressure of reaction of about 8-12.0 Mpa). The industrial process is simple and, for example, only 1-2 reactors need to be used in the process, thereby resulting in low capital costs for construction of facilities to carry out the process of this invention.
(4) As the present invention utilizes a total return mixed cracking reactor in combination with a vacuum gas oil circulating cracking and high-temperature, high-pressure online treating reactor, it avoids the need to build more hydrotreating and vacuum gas oil hydrocracking cracking facilities. It also results in products of high quality. After separating the product into components, the naphtha recovered can be used as reforming stock and for cracking materials, and the diesel oil is sweet oil on average having a hexadecane number with low-nitrogen content and of high quality.
Because vacuum gas oil or bottom oil circulation is adopted as a feature of this invention, it increases the flexibility of the operation of the facility. The present process is preferably applied to mainly produce naphtha and diesel oil. If necessary, however, it can also be slightly modified to produce high quality vacuum gas oil.
The process of the present invention can play a specific role. It can realize a very high recovery rate. It has very advantageous benefits in processing all kinds of heavy oils, including those of low quality, as well as viscous crude, including normal pressure residual oil and very viscous ones. It is especially effective in processing petroleum residual oil with high nitrogen content, high metal content, high viscosity, having a high acid number and having high residual coke, still realizing conversion rates of more than 80-95%. Thus, the process of this invention truly has a wide-range of industrial applications.
DETAILED DESCRIPTION OF THE DRAWING
FIG. 1 shows a schematic process flow chart of the present process, wherein the reference numerals in the appended drawing are described as follows:
1 indicates a hydrogen heating furnace.
2 indicates an oil heating furnace.
3 indicates a hot high-pressure separator.
4 indicates a slurry-bed hydrocracking reactor.
5 indicates a flash drum.
6 indicates a vacuum distillation tower.
7 indicates a separator.
8 indicates a fixed-bed hydrotreating reactor.
9 indicates a cold high-pressure separator.
10 indicates a cold low-pressure separator.
11 indicates an atmospheric vacuum distillation tower.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the actual operation of the present invention as indicated in FIG. 1, a highly dispersed multimetallic catalyst (UPC series) is used in a slurry-bed hydrocracking reactor. Catalyst No. 3936 or RN-2 hydrotreating catalyst is used in the hydrotreating reactor having a fixed bed. A residual oil of raw materials containing a highly dispersed multimetallic catalyst and a little curing agent is mixed with vacuum gas oil or bottom oil and pumped to the residual oil heating furnace 2 . After being heated to about 380-480° C., the residual oil is mixed again with the hydrogen coming out of the hydrogen heating furnace 1 and having a corresponding temperature. This first mixed stream is then fed into the slurry-bed hydrocracking reactor 4 . The effluent out of the hydrocracking reactor 4 is flashed and distilled into gas and liquid phases in a hot high-pressure separator 3 . The material flow in the gas phase, including mixed hydrogen, is fed online directly into fixed-bed hydrotreating reactor 8 from the top of separator 3 . The liquid flow (i.e., black oil with catalyst) coming out of the bottom of separator 3 is fed into a flash drum 5 to be flash distilled after it is decompressed. The material flow out of the top of the flash drum 5 , together with the sidedraw material flow out of vacuum distillation tower 6 , and also together with the material flow out of the bottom of separator 7 , are joined with each other to form a second mixed stream. At least a portion of this second mixed stream may be sent to reactor 8 for hydrotreating, or a portion may be remixed with the oil out of the bottom of vacuum distillation tower 11 which is used as exit equipment for processing vacuum gas oil. Alternatively, this second mixed stream could also be mixed with the recycled bottoms, then sent to the slurry bed hydrocracking reactor 4 via heating furnace 2 . The liquid flow out of the bottom of the flash drum 5 is sent to a vacuum distillation tower 6 . A part of the bottom oil in the bottoms stream from the vacuum distillation tower 6 is withdrawn from the system while another part is recirculated as bottom oil. The material flow out of the top of the vacuum distillation tower 6 is sent to a separator 7 . The gas phase from the top of the separator 7 is withdrawn from the system as end gas. The reaction product and hydrogen coming from the fixed-bed online hydrotreating reactor 8 is sent into a cold high-pressure separator 9 to effect separation of oil, gas and water after being heat-exchanged and cooled down and being water-flooded whereby ammonium salt is generated after the dissolution step. Sulfur-containing wastewater with dissolved NH 3 and H 2 S is withdrawn from cold high-pressure separator 9 and is sent together with the combination of sulfur-containing wastewater coming from the cold low-pressure separator 10 to be processed jointly. The flashed gas from the cold high-pressure separator had a high content of hydrogen. Most of that hydrogen is returned to the reaction system as recycled hydrogen after being boosted in pressure by a recycled hydrogen compressor and mixed with fresh hydrogen. In order to maintain the needed concentration of recycled hydrogen to meet system requirements, it may be necessary to blow off a small amount of gas from the cold high-pressure separator as a waste hydrogen gas stream. In order to minimize hydrogen loss, a membrane separator may be used to recover some of the hydrogen from this waste hydrogen stream. The end gas released by the membrane separator is sent off to be desulfated. The oil flow through the cold high-pressure separator 9 and cold low-pressure separator 10 is sent to atmospheric vacuum distillation tower 11 after being heat exchanged and heated. A mixed naphtha stream is then recovered from the top of the vacuum distillation tower 11 , a diesel oil product is obtained as a sidedraw from tower 11 , and bottom oil out of the bottom of the vacuum distillation tower 11 is mixed with decompressed vacuum gas oil taken as a sidedraw from vacuum distillation tower 6 to form raw materials for the catalytic cracking equipment.
EXAMPLE
In the following example, Karamay atmospheric residue was used in connection with carrying out a hydrocracking process in accordance with this invention. The reaction temperature of the Karamay atmospheric residue in the 30-100 ton/year medium-size facility was 400-480° C. The hydrogen partial pressure was 4-12 Mpa. Multimetallic liquid catalyst Type UPC-21 was used. The total volume hourly space velocity of raw materials was 1.0-1.3 h −1 . The volume hourly space velocity of fresh raw materials was 0.4-0.8 h −1 . The yield of this slurry-bed hydrocracking cracking process reaches up to 90-97 m % when carried out at temperatures below 524° C. The concrete data for this process is as follows.
1. Product distribution resulting from the suspension bed hydrocracking cracking of atmospheric residue from Karamay Oil field, China under different reaction temperatures (single pass yield):
Reaction temperature,
430
435
440
445
450
° C.
hydrogen partial
10.0
10.0
10.0
10.0
10.0
pressure, Mpa
Hydrogen-oil ratio,
740/1
742/1
757/1
737/1
735/1
Mm 3 /m 3
Total volume volume
1.13
1.13
1.10
1.13
1.14
hourly space
velocity, h −1
Product distribution,
m %
C1-C4 (gas) yield
4.63
4.70
4.76
4.96
5.03
C5-180° C. (naphtha
6.67
7.97
9.27
10.28
11.68
fraction) yield
180-350° C. (diesel oil
19.02
22.56
24.08
27.41
30.55
fraction) yield
350-524° C. (vacuum
39.89
39.51
37.50
37.62
35.00
gas oil fraction)
yield
<524° C. yield
70.21
75.13
75.61
80.27
82.25
>524° C. (bottom oil)
30.84
26.06
25.39
20.90
19.00
yield
Hydrogen loss: m %
1.06
1.09
1.13
1.18
1.25
Total yield: m %
101.6
101.19
101.0
101.18
101.25
2. Product distribution resulting from the suspension bed hydrocracking of atmospheric residue from Karamay Oil Field, China under different reaction temperatures (single pass and circulating yield):
Reaction temperature, ° C.
440
440
445
445
Hydrogen partial pressure, Mpa
10.0
10.0
10.0
10.0
Hydrogen-oil ratio, Mm 3 /m 3
757/1
800/1
737/1
800/1
Recycling ratio (fresh raw
100
66/34
100
70/30
material/bottom oil)
Total volume volume hourly space
1.10
1.14
1.13
1.14
velocity, 1/h
Volume volume hourly space
1.10
0.75
1.13
0.80
velocity of fresh raw material, h −1
Product distribution, m %
C1-C4 (gas) yield
4.76
5.50
4.96
7.40
C5-180° C. (naphtha fraction)
9.27
9.60
10.28
13.80
yield
180-350° C. (diesel oil fraction)
24.08
27.30
27.41
29.60
yield
350-524° C. (vacuum gas oil
37.50
53.10
37.62
45.40
fraction) yield
<524° C. yield
75.61
96.30
80.27
96.20
>524° C. (bottom oil) yield
25.39
4.60
20.90
5.00
Hydrogen loss: m %
1.13
0.92
1.18
1.18
Total yield: m %
101.0
100.92
101.18
101.18
3. Composition and characteristics of the naphtha fraction (IBP-180° C.) before and after refining
Before
After
After
After
After
Refining condition
refining
refining
refining
refining
refining
Fraction components of refining
—
IBP-350
IBP-350
IBP-350
IBP-500
raw materials, ° C.
Refining temperature, ° C.
—
360
380
400
400
Refining pressure, Mpa
—
10.0
10.0
10.0
10.0
Composition of Hydrocarbon
family, m %
Normal paraffin hydrocarbon
20.61
24.94
24.97
25.05
21.30
Isoalkane
32.81
38.04
38.95
39.62
36.50
Naphthene hydrocarbon
15.91
31.63
31.34
30.97
33.65
aromatic hydrocarbon
10.40
5.39
4.74
4.36
6.10
olefine hydrocarbon
20.27
0.0
0.0
0.0
0.0
Potential content of aromatic
—
38˜42
38˜42
38˜42
38˜42
hydrocarbon, m %
Octane value
78.1
73.4
73.9
74.3
75.0
Density (20° C.), g/cm 3
0.7543
0.7451
0.7454
0.7519
0.7499
Sulfur, μg/g
440
0.5˜1.0
0.5˜1.0
0.2˜0.6
0.5˜1.0
Nitrogen, μg/g
658
1.0˜2.0
1.0˜2.0
0.5˜1.5
1.0˜2.0
Basic nitrogen, μg/g
160
<1.0
<1.0
<1.0
<1.0
4. Composition and characteristics of the diesel oil fraction (180-350° C.) before and after refining
Before
After
After
After
After
Item
refining
refining
refining
refining
refining
Fraction components of refining
—
IBP-350
IBP-350
IBP-350
IBP-500
raw materials, ° C.
Refining temperature, ° C.
—
360□
380□
400□
400□
Refining pressure, Mpa
—
10.0
10.0
10.0
10.0
Density (20° C.), g/cm 3
0.8464
0.8303
0.8241
0.8202
0.8449
Viscosity (20° C.), mm 2 /s
8.79
3.83
3.47
3.40
3.97
Viscosity (40° C.), mm 2 /s
3.16
2.70
2.33
2.18
2.58
Sulfur, μg/g
570
18.2
13.5
12.4
19.3
Nitrogen, μg/g
1510
5.5
4.3
4.1
8.9
Basic nitrogen, μg/g
780
5.0
3.9
3.6
5.9
Aniline point, ° C.
62.2
72.0
72.0
70.1
67.9
Centane value
49.6
58.1
60.3
62.2
53.1
Acidity, mg KOH/100 ml
35.62
3.40
2.41
2.14
3.45
Solidifying point, ° C.
−38
−37
−37
−32
−37
Cold filtering point, ° C.
<−20
<−20
<−20
<−20
<−20
While the invention has been described in connection with a preferred and several alternative embodiments, it will be understood that there is no intention to thereby limit the invention. On the contrary, it is intended that this invention cover all alternatives, modifications and equivalents as may be reasonably included within the spirit and scope of the invention as defined by the appended claims, which are the sole definition of the invention.
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The invention relates to a new and improved heavy oil hydrocracking process using a multimetallic liquid catalyst in a slurry-bed reactor, particularly an improvement of lightweight treatment of heavy oil in the petroleum processing technology. According to the present invention, a slurry-bed hydrocracking reactor and a highly dispersed multimetallic liquid catalyst are mainly applied during the process. A fixed-bed hydrotreating reactor is also used on line to enhance lightweight oil yield from heavy oil under normal pressure.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to novel cationic lipids that can be used in combination with other lipid components such as cholesterol and PEG-lipids to form lipid nanoparticles with oligonucleotides, to facilitate the cellular uptake and endosomal escape, and to knockdown target mRNA both in vitro and in vivo.
[0002] Cationic lipids and the use of cationic lipids in lipid nanoparticles for the delivery of oligonucleotides, in particular siRNA and miRNA, have been previously disclosed. Lipid nanoparticles and use of lipid nanoparticles for the delivery of oligonucleotides, in particular siRNA and miRNA, has been previously disclosed. Oligonucleotides (including siRNA and miRNA) and the synthesis of oligonucleotides has been previously disclosed. (See U.S. patent applications: U.S. 2006/0083780, U.S. 2006/0240554, U.S. 2008/0020058, U.S. 2009/0263407 and U.S. 2009/0285881 and PCT patent applications: WO 2009/086558, WO2009/127060, WO2009/132131, WO2010/042877, WO2010/054384, WO2010/054401, WO2010/054405 and WO2010/054406). See also Semple S. C. et al., Rational design of cationic lipids for siRNA delivery, Nature Biotechnology, published online 17 Jan. 2010; doi:10.1038/nbt.1602.
[0003] Other cationic lipids are disclosed in U.S. patent applications: U.S. 2009/0263407, U.S. 2009/0285881, U.S. 2010/0055168, U.S. 2010/0055169, U.S. 2010/0063135, U.S. 2010/0076055, U.S. 2010/0099738 and U.S. 2010/0104629.
[0004] Traditional cationic lipids such as CLinDMA and DLinDMA have been employed for siRNA delivery to liver but suffer from non-optimal delivery efficiency along with liver toxicity at. higher doses. It is an object of the instant invention to provide a cationic lipid scaffold that demonstrates enhanced efficacy along with lower liver toxicity as a result of lower lipid levels in the liver. The present, invention employs low molecular weight cationic lipids with one short lipid chain to enhance the efficiency and tolerability of in vivo delivery of siRNA.
SUMMARY OF THE INVENTION
[0005] The instant invention provides for novel cationic lipids that can be used in combination with other lipid components such as cholesterol and PEG-lipids to form lipid nanoparticles with oligonucleotides. It is an object of the instant invention to provide a cationic lipid scaffold that demonstrates enhanced efficacy along with lower liver toxicity as a result of lower lipid levels in the liver. The present invention employs low molecular weight cationic lipids with one short lipid chain to enhance the efficiency and tolerability of in vivo delivery of siRNA.
BRIEF DESCRIPTION OF THE FIGURES
[0006] FIG. 1 : LNP (Compound 1) efficacy in mice.
[0007] FIG. 2 . LNP (Compound 1) efficacy in. rat (ApoB siRNA).
[0008] FIG. 3 . Cationic lipid (Compound 1) levels in rat liver.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The various aspects and embodiments of the invention are directed to the utility of novel cationic lipids useful in lipid nanoparticles to deliver oligonucleotides, in particular, siRNA and miRNA, to any target gene. (See U.S. patent applications: U.S. 2006/0083780, U.S. 2006/0240554, U.S. 2008/0020058, U.S. 2009/0263407 and U.S. 2009/0285881 and PCI patent applications: WO 2009/086558, WO2009/127060, WO2009/132131, WO2010/042877, WO2010/054384, WO2010/054401, WO2010/054405 and WO2010/054406). See also Semple S. C. et al., Rational design of cationic lipids for siRNA delivery, Nature Biotechnology, published online 17 Jan. 2010; doi:10.1038/nbt.1602.
[0010] The cationic lipids of the instant invention are useful components in a lipid nanoparticle for the delivery of oligonucleotides, specifically siRNA and miRNA.
[0011] In a first embodiment of this invention, the cationic lipids are illustrated by the Formula A:
[0000]
[0000] wherein:
[0012] R 1 and R 2 are independently selected from H, (C 1 -C 6 )alkyl, heterocyclyl, and polyamine, wherein said alkyl, heterocyclyl and polyamine are optionally substituted with one to three substituents selected from R′, or R 1 and R 2 can be taken together with the nitrogen to which they are attached, to form a monocyclic heterocycle with 4-7 members optionally containing, in addition to the nitrogen, one or two additional heteroatoms selected from M, O and S, said monocyclic heterocycle is optionally substituted with one to three substituents selected from R′;
[0013] R 3 is selected from H and (C 1 -C 6 )alkyl, said alkyl optionally substituted with one to three substituents selected from R′;
[0014] R′ is independently selected from halogen, R″, OR″, SR″, CN, CO 2 R″ and CON(RH) 2 ;
[0015] R″ is independently selected from H and (C 1 -C 6 )alkyl, wherein said alkyl is optionally substituted with halogen and OH;
[0016] n is 0, 1, 2, 3, 4 or 5; and
[0017] L 1 and L 2 are independently selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl, said alkyl and alkenyl are optionally substituted with one or more substituents selected from R′;
[0018] or any pharmaceutically acceptable salt or stereoisomer thereof.
[0019] In a second embodiment, the invention features a compound having Formula A, wherein:
[0020] R 1 and R 2 are each methyl:
[0021] R 3 is H;
[0022] b is 0;
[0023] L 1 is selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl; and
[0024] L 2 is selected from C 3 -C 9 alkyl and C 3 -C 9 alkenyl;
[0025] or any pharmaceutically acceptable salt or stereoisomer thereof.
[0026] In a third embodiment, the invention features a compound having Formula A, wherein:
[0027] R 1 and R 2 are each methyl;
[0028] R 3 is H;
[0029] n is 0;
[0030] L 1 is selected from C 3 -C 9 alkyl and C 3 -C 9 alkenyl; and
[0031] L 2 is selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl;
[0032] or any pharmaceutically acceptable salt or stereoisomer thereof.
[0033] In a fourth embodiment, the invention features a compound having Formula A, wherein:
[0034] R 1 and R 2 are each methyl;
[0035] R 3 is H;
[0036] n is 1;
[0037] L 1 is selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl; and
[0038] L 2 is selected from C 3 -C 9 alkyl and C 3 -C 9 alkenyl;
[0039] or any pharmaceutically acceptable salt or stereoisomer thereof.
[0040] In a fifth embodiment, the invention features a compound having Formula A, wherein:
[0041] R 1 and R 2 are each methyl;
[0042] R 3 is H;
[0043] n is 2;
[0044] L 1 is selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl; and
[0045] L 2 is selected from C 3 -C 9 alkyl and C 3 -C 9 alkenyl;
[0046] or any pharmaceutically acceptable salt, or stereoisomer thereof.
[0047] Specific cationic lipids are:
[0000] (2S)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1 -yloxy]undecan-2-amine (Compound 1);
(2S)-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]undecan-2-amine (Compound 2);
(2S)-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]dodecan-2-amine (Compound 3);
(2R)-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]dodecan-2-amine (Compound 4);
(2S)-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]decan-2-amine (Compound 5);
(2S)-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]nonan-2-amine (Compound 6);
(2S)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1 -yloxy]tridecan-2-amine (Compound 7);
(2S)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]nonan-2-amine (Compound 8);
(2R)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]dodecan-2-amine (Compound 9);
(2S)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]dodecan-2-amine (Compound 10);
(2S)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]decan-2-amine (Compound 11); and
(2S,12Z,15Z)-N,N-dimethyl-1-(octyloxy)henicosa-12,15-dien-2-amine (Compound 12);
(2R,12Z,15Z)-1-(decyloxy)-N,N-dimethylhenicosa-12,15-dien-2-amine (Compound 13);
(2R,12Z,15Z)-1-(hexyloxy)-N,N-dimethylhenicosa-12,15-dien-2-amine (Compound 14);
(2R,12Z,15Z)-1-(hexadecyloxy)-N,N-dimethylhenicosa-12,15-dien-2-amine (Compound 15);
(2R,12Z,15Z)-N,N-dimethyl-1-(undecyloxy)henicosa-12,15-dien-2-amine (Compound 16);
N,N-dimethyl-2-{[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]methyl}undecan-1-amine (Compound 17);
N,N-dimethyl-3-{[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]methyl}dodecan-1-amine (Compound 18); and
(2S)-N,N-dimethyl-1-({8-[(1R,2R)-2-{[(1S,2S)-2-pentylcyclopropyl]methyl}cyclopropyl]octyl}oxy)tridecan-2-amine (Compound 19);
or any pharmaceutically acceptable salt or stereoisomer thereof.
[0048] In another embodiment, the cationic lipids disclosed are useful in the preparation of lipid nanoparticles.
[0049] In another embodiment, the cationic lipids disclosed are useful components in a lipid nanoparticle for the delivery of oligonucleotides.
[0050] In another embodiment, the cationic lipids disclosed are useful components in a lipid nanoparticle for the delivery of siRNA and miRNA.
[0051] In another embodiment, the cationic lipids disclosed are useful components in a lipid nanoparticle for the delivery of siRNA.
[0052] The cationic lipids of the present invention may have asymmetric centers, chiral axes, and chiral planes (as described in: EX. Eliel and S. H. Wilen, Stereochemistry of Carbon. Compounds, John Wiley & Sons, New York, 1994, pages 1119-1190), and occur as racemates, racemic mixtures, and as individual diastereomers, with all possible isomers and mixtures thereof, including optical isomers, being included in the present invention, in addition, the cationic lipids disclosed herein may exist as tautomers and both tautomeric forms are intended to be encompassed by the scope of the invention, even though only one tautomeric structure is depicted.
[0053] It is understood that substituents and substitution patterns on the cationic lipids of the instant invention can be selected by one of ordinary skill in the art to provide cationic lipids that are chemically stable and that can be readily synthesized by techniques known in the art, as well as those methods set forth below, from readily available starting materials. If a substituent is itself substituted with more than one group, it is understood that these multiple groups may be on the same carbon or on different carbons, so long as a stable structure results.
[0054] It is understood that one or more Si atoms can be incorporated into the cationic lipids of the instant invention by one of ordinary skill in the art to provide cationic lipids that are chemically stable and that can be readily synthesized by techniques known in the art, from readily available starting materials.
[0055] In the compounds of Formula A, the atoms may exhibit their natural isotopic abundances, or one or more of the atoms may be artificially enriched in a particular isotope having the same atomic number, but an atomic mass or mass number different, from the atomic mass or mass number predominantly found in nature. The present invention is meant to include all suitable isotopic variations of the compounds of Formula A. For example, different isotopic forms of hydrogen (H) include protium ( 1 H) and deuterium ( 2 H). Protium is the predominant hydrogen isotope found in nature. Enriching for deuterium may afford certain therapeutic advantages, such as increasing in vivo half-life or reducing dosage requirements, or may provide a compound, useful as a standard for characterization of biological samples. Isotopically-enriched compounds within Formula A can be prepared without undue experimentation by conventional techniques well known to those skilled in the art or by processes analogous to those described in the Scheme and Examples herein using appropriate isotopically-enriched reagents and/or intermediates.
[0056] As used herein, “alkyl” means a straight chain, cyclic or branched saturated aliphatic hydrocarbon having the specified number of carbon atoms.
[0057] As used herein, “alkenyl” means a straight chain, cyclic or branched, unsaturated aliphatic hydrocarbon having the specified number of carbon atoms including but not limited to diene, triene and tetraene unsaturated aliphatic hydrocarbons.
[0058] Examples of a cyclic “alkyl” or “alkenyl are:
[0000]
[0059] As used herein, “heterocyclyl” or “heterocycle” means a 4- to 10-membered aromatic or nonaromatic heterocycle containing from 1 to 4 heteroatoms selected from the group consisting of O, N and S, and includes bicyclic groups. “Heterocyclyl” therefore includes, the following: benzoiimdazolyl, benzofuranyl, benzofurazanyl, benzopyrazolyl, benzotriazolyl, benzothiophenyl, benzoxazolyl, carbazolyl, carbolinyl, cinnolinyl, furanyl, imidazolyl, indolinyl, indolyl, indolazinyl, indazolyl, isobenzofuranyl, isoindolyl, isoquinolyl, isothiazolyl, isoxazolyl, naphthpyridinyl, oxadiazolyl, oxazolyl, oxazoline, isoxazoline, oxetanyl, pyranyl, pyrazinyl, pyrazolyl, pyridazinyl, pyridopyridinyl, pyridazinyl, pyridyl, pyrimidyl, pyrrolyl, quinazolinyl, quinolyl, quinoxalinyl, tetrahydropyranyl, tetrazolyl, tetrazolopyridyl, thiadiazolyl, thiazolyl, thienyl, triazolyl, azetidinyl, 1,4-dioxanyl, hexahydroazepinyl, piperazinyl, piperidinyl, pyrrolidinyl, morpholinyl, thiomorpholinyl, dihydrobenzoimidazolyl, dihydrobenzofuranyl, dihydrobenzothiophenyl, dihydrobenzoxazolyl, dihydrofuranyl, dihydroiimdazolyl, dihydroindolyl, dihydroisooxazolyl, dihydroisothiazolyl, dihydrooxadiazolyl, dihydrooxazolyl, dihydropyrazinyl, dihydropyrazolyl, dihydropyridinyl, dihydropyrimidinyl, dihydropyrrolyl, dihydroquinolinyl, dihydroietrazolyl, dihydrothiadiazolyl, dihydrothiaxolyl, dihydrothienyl, dihydrotriazolyl, dihydroazetidinyl, methylenedioxybenzoyl, tetrahydrofuranyl, and tetrahydrothienyl, and N-oxides thereof all of which are optionally substituted with one to three substituents selected from R″.
[0060] As used herein, “polyamine” means compounds having two or more amino groups. Examples include putrescine, cadaverine, spermidine, and spermine.
[0061] As used herein, “halogen” means Br, Cl, F and I.
[0062] In an embodiment of Formula A, R 1 and R 2 are independently selected from H and (C 1 -C 6 )alkyl, wherein said alkyl is optionally substituted with one to three substituents selected from R′, or R 1 and R 2 can be taken together with the nitrogen to which they are attached to form a monocyclic heterocycle with 4-7 members optionally containing, in addition to the nitrogen, one or two additional heteroatoms selected from N, O and S, said monocyclic heterocycle is optionally substituted with one to three substituents selected from R′.
[0063] In an embodiment of Formula A, R 1 and R 2 are independently selected from H, methyl, ethyl and propyl, wherein said methyl, ethyl and propyl are optionally substituted with one to three substituents selected from R′, or R 1 and R 2 can be taken together with the nitrogen to which they are attached to form a monocyclic heterocycle with 4-7 members optionally containing, in addition to the nitrogen, one or two additional heteroatoms selected from N, O and S, said monocyclic heterocycle is optionally substituted with one to three substituents selected from R′.
[0064] In an embodiment of Formula A, R 1 and R 2 are independently selected from H, methyl, ethyl and propyl.
[0065] In an embodiment of Formula A, R 1 and R 2 are each methyl.
[0066] In an embodiment of Formula A, R 3 is selected from H and methyl.
[0067] In an embodiment of Formula A, R 3 is H.
[0068] In an embodiment of Formula A, R′ is R″.
[0069] In an embodiment of Formula A, R″ is independently selected from H, methyl, ethyl and propyl, wherein said methyl, ethyl and propyl are optionally substituted with one or more halogen and OH.
[0070] In an embodiment of Formula A, R″ is independently selected from H, methyl, ethyl and propyl.
[0071] In an embodiment of Formula A, n is 0, 1 or 2.
[0072] In an embodiment of Formula A, n is 0 or 1.
[0073] In an embodiment of Formula A, n is 0.
[0074] In an embodiment of Formula A, L 1 is selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl, which are optionally substituted with halogen and OH.
[0075] In an embodiment of Formula A, L 1 is selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl.
[0076] In an embodiment of Formula A, L 1 is selected from C 3 -C 24 alkenyl.
[0077] In an embodiment of Formula A, L 1 is selected from C 12 -C 24 alkenyl.
[0078] In an embodiment of Formula A, L 1 is C 18 alkenyl.
[0079] In an embodiment of Formula A, L 1 is:
[0000]
[0080] In an embodiment of Formula A, L 1 is C 8 alkyl.
[0081] In an embodiment of Formula A, L 2 is selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl, which are optionally substituted with halogen and OH.
[0082] In an embodiment of Formula A, L 2 is selected from C 3 -C 24 alkyl and C 3 -C 24 alkenyl.
[0083] In an embodiment of Formula A, L 2 is selected from C 3 -C 24 alkenyl.
[0084] In an embodiment of Formula A, L 2 is selected from C 12 -C 24 alkenyl.
[0085] In an embodiment of Formula A, L 2 is C 19 alkenyl.
[0086] In an embodiment of Formula A, L 2 is:
[0000]
[0087] In an embodiment of Formula A, L 2 is selected from C 3 -C 9 alkyl and C 3 -C 9 alkenyl, which are optionally substituted with halogen and OH.
[0088] In an embodiment of Formula A, L 2 is selected from C 5 -C 9 alkyl and C 5 -C 9 alkenyl, which are optionally substituted with halogen and OH.
[0089] In an embodiment of Formula A, L 2 is selected from C 7 -C 9 alkyl and C 7 -C 9 alkenyl, which are optionally substituted with halogen and OH.
[0090] In an embodiment of Formula A, L 2 is selected from C 3 -C 9 alkyl and C 3 -C 9 alkenyl.
[0091] In an embodiment of Formula A, L 2 is selected from C 5 -C 9 alkyl and C 5 -C 9 alkenyl.
[0092] In an embodiment of Formula A, L 2 is selected from C 7 -C 9 alkyl and C 7 -C 9 alkenyl.
[0093] In an embodiment of Formula A, L 2 is C 3 -C 9 alkyl.
[0094] In an embodiment of Formula A, L 2 is C 5 -C 9 alkyl.
[0095] In an embodiment of Formula A, L 2 is C 7 -C 9 alkyl.
[0096] In an embodiment of Formula A, L 2 is C 9 alkyl.
[0097] In an embodiment of Formula A, “heterocyclyl” is pyrolidine, piperidine, morpholine, imidazole or piperazine.
[0098] In an embodiment of Formula A, “monocyclic heterocyclyl” is pyrolidine, piperidine, morpholine, imidazole or piperazine.
[0099] In an embodiment of Formula A, “polyamine” is putrescine, cadaverine, spermidine or spermine.
[0100] In an embodiment, “alkyl” is a straight chain saturated aliphatic hydrocarbon having the specified number of carbon atoms.
[0101] In an embodiment, “alkenyl” is a straight chain unsaturated aliphatic hydrocarbon having the specified number of carbon atoms.
[0102] Included in the instant invention is the free form of cationic lipids of Formula A, as well as the pharmaceutically acceptable salts and stereoisomers thereof. Some of the isolated specific cationic lipids exemplified herein, are the protonated salts of amine cationic lipids. The terra “free form” refers to the amine cationic lipids in non-salt form. The encompassed pharmaceutically acceptable salts not only include the isolated salts exemplified for the specific cationic lipids described herein, but also all the typical pharmaceutically acceptable salts of the free form of cationic lipids of Formula A. The free form of the specific salt cationic lipids described may be isolated using techniques known in the art. For example, the free form may be regenerated by treating the salt with a suitable dilute aqueous base solution such as dilute aqueous NaOH, potassium carbonate, ammonia and sodium bicarbonate. The free forms may differ from their respective salt forms somewhat, in certain physical properties, such as solubility in polar solvents, but the acid and base salts are otherwise pharmaceutically equivalent to their respective free forms for purposes of the invention.
[0103] The pharmaceutically acceptable salts of the instant cationic lipids can be synthesized from the cationic lipids of this invention which contain a basic or acidic moiety by conventional chemical methods. Generally, the salts of the basic cationic lipids are prepared either by ion exchange chromatography or by reacting the free base with stoichiometric amounts or with an excess of the desired salt-forming inorganic or organic acid in a suitable solvent or various combinations of solvents. Similarly, the salts of the acidic compounds are formed by reactions with the appropriate inorganic or organic base.
[0104] Thus, pharmaceutically acceptable salts of the cationic lipids of this invention include the conventional non-toxic salts of the cationic lipids of this invention as formed by reacting a basic instant cationic lipids with an inorganic or organic acid. For example, conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like, as well as salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxy-benzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, trifluoroacetic (TFA) and the like.
[0105] When the cationic lipids of the present invention are acidic, suitable “pharmaceutically acceptable salts” refers to salts prepared form pharmaceutically acceptable non-toxic bases including inorganic bases and organic bases. Salts derived from inorganic bases include aluminum, ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous, potassium, sodium, zinc and the like. Particularly preferred axe the ammonium, calcium, magnesium, potassium and sodium salts. Salts derived from pharmaceutically acceptable organic non-toxic bases include salts of primary, secondary and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as arginine, betaine caffeine, choline, N,N 1 -dibenzylethylenediamine, diethyiamin, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, polyamine resins, procaine, purines, theobromine, triethylamine, trimethylamine tripropylamine, tromethamine and the like.
[0106] The preparation of the pharmaceutically acceptable salts described above and other typical pharmaceutically acceptable salts is more fully described by Berg et al., “Pharmaceutical Salts,” Pharm. Set, 1977:66:1-19.
[0107] It will also be noted that the cationic lipids of the present invention are potentially internal salts or zwitterions, since under physiological conditions a deprotonated acidic moiety in the compound, such as a carboxyl group, may be anionic, and this electronic charge might then be balanced off Internally against the cationic charge of a protonated or alkylated basic moiety, such as a quaternary nitrogen atom.
EXAMPLES
[0108] Examples provided are intended to assist in a further understanding of the invention. Particular materials employed, species and conditions are intended to be further illustrative of the invention arid not limitative of the reasonable scope thereof. The reagents utilized in synthesizing the cationic lipids are either commercially available or are readily prepared by one of ordinary skill in the art.
[0109] Synthesis of the novel cationic lipids is a linear process starting from epichlorohydrin (i) (General Scheme 1). Epoxide opening, ring closure with lipid alkoxide delivers epoxy ether intermediate ii. Original addition to the epoxide provides secondary alcohol intermediate iii. Mitsinobu inversion with azide followed by reduction yields primary amine intermediates v. Reductive animation provides the tertiary amine derivatives vi.
[0000]
[0110] An alternative synthesis of the novel cationic lipids starting from epichlorohydrin (i) is depicted in General Scheme 2. Epoxide opening, ring closure with lipid Grignard delivers epoxide intermediate vii. Alkoxide addition to the epoxide provides secondary alcohol intermediate iii. Mitsinobu inversion with azide followed by reduction yields primary amine intermediates v. Reductive animation provides the tertiary amine derivatives vi.
[0000]
[0111] Synthesis of the homologated cationic lipids x (General Scheme 3) begins with oxidation of intermediate iii to ketone vii using Dess-Martin Periodinane. Conversion of the ketone to the nitrile viii is accomplished with TOSMIC. Reduction of the nitrite with lithium aluminum hydride gives primary amine ix. Reductive animation provides cationic lipids x.
[0000]
[0112] Synthesis of doubly homologated cationic lipids xiii begins with ketone vii. Peterson olefination generates the unsaturated amide xi. Conjugate reduction with L-Selectride gives amide xii. Amide reduction with lithium aluminum hydride gives cationic lipids xiii.
[0000]
[0000] (2S)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]undecan-2-amine (Compound 1)
[0000]
[0113] A 250 ml, rb flask was charged with magnetic stirbar, tetrabutyl ammonium bromide (TBAB, 2.72 g, 8.4 mmol), linoleyl alcohol (225 g, 884 mmol), and sodium hydroxide (50.7 g, 1.2 mol), then cooled in an ice bath. The (S)-epichlorohydrin (156 g, 1.69 mol) was added slowly over 2 hours and then warmed to ambient temperature and stirred overnight, 259 mL of hexane was added and allowed to stir for 15 mins, then mixture was filtered and organic layer was concentrated in vacuo. The product was purified using 0-10% ethyl acetate/hexane gradient on 330 g silica column to give (2R)-2-{[(9Z,12Z)-octadeca-9,12-dien-1-yloxyl]methyl}oxirane. 1 H NMR (CDCl 3 , 300 mHz) δ 0.90-0.86 (m, 3 H), 1.29 (s, 16 H), 1.55-1.64 (m, 2 H), 2.00-2.07 (m, 4 H), 2.58-2.61 (m, 1 H), 2.74-2.80 (m, 3 H), 3.12-3.15 (m, 1 H) 3.34-3.52 (m,3 H), 3.67-3.72 (dd, J=12 Hz, 1 H) 5.30-5.35 (m, 4 H); HRMS (m+1) calc'd 323.2872, found 323.2951.
[0000]
[0114] The epoxide (15 g, 46.5 mmol) was dissolved in THF and cooled to 0° C. under stream of Nitrogen. Octyl Grignard (25.6 mL 2M solution, 51.2 mmol) was added dropwise and then heated in microwave at 120° C. for one hour. The precipitate was filtered off and the solvent evaporated in vacuo. The crude oil was directly loaded onto a silica gel column and eluted with 0-10% gradient (hexane-ethyl acetate) to give (2R)-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]undecan-2-ol. LC/MS (m+1)=437.6.
[0000]
[0115] Triphenyl phosphine (14.4 g, 55 mmol) was dissolved in THF and cooled to 0° C. under nitrogen. Di-tertbutyl azodicarboxylate (13.7 g, 59.5 mmol) was added slowly and the reaction was stirred for 30 mins. Then the alcohol (20 g, 45.8 mmol) was added dropwise and allowed to stir for 10 mins, then diphenyl phosphorylazide (15.1 g, 55 mmol) was added and allowed to stir overnight, warming to ambient temperature. The reaction was evaporated to dryness in vacuo and directly loaded onto a silica gel column and eluted with 0-10% ethyl acetate/hexane gradient to provide (2S)-2-azidoundecyl (9Z,12Z)-octadeca-9,12-dien-1-yl ether which was carried directly into the next reaction without characterization.
[0000]
[0116] Triphenyl phosphine (4.54 g, 17.3 mmol) and the azide (8 g, 17.3 mmol) were dissolved in THF. The reaction mixture was split into 3 μw tubes and Irradiated at 120° C. for 1 hour each. Considerable pressure built in each tube so care should be noted. LC indicated 100% conversion to phosphoimine intermediate. To each, tube was added ˜3 mL of water and the reaction irradiated for 10 min at 120° C. The reaction mixtures were combined and concentrated to remove organic solvent. Hexane was added to precipitate phosphine oxides which were filtered through sintered glass funnel. The solvent was then removed in vacuo. The crude product was purified using HPLC with 30 min run and 60-100% water/acetonitrile gradient. The combined HPLC fractions were neutralized with sodium bicarbonate evaporated in vacuo. The pure product was partitioned between water/hexanes. The organic layer was dried over sodium sulfate, filtered and evaporated in vacuo to afford (2S)-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]undecan-2-amine (2), 1 H NMR (CDCl 3 , 300 mHz) δ 0.88-0.87 (m, 6H), 1.25-1.29 (s, 32 H), 1.54-1.54 (m, 2 H), 2.03-2.05 (m, 4 H), 2.23 (s, 2 H), 2.75-2.76 (m, 2 H), 2.96 (m, 1 H), 3.13-3.18 (m, 1 H), 3.38-3.45 (m, 3 H), 5.31-5.38 (m, 4 H); LC/MS (m+1)=436.7.
[0000]
[0117] The primary amine (3.5 g, 8 mmol) was dissolved in THF and formaldehyde (3.26 g, 40.2mol) was added, followed by triacetoxy borohydride (5.1 g, 24.1 mmol). The reaction was stirred at ambient temperature for 15 mins. LC/MS indicated 100% conversion to product. Added 1M NaOH until basic and extracted with hexane and washed with water. Retained organic layer and removed solvent in vacuo. Purified using 60-100% water/acetonitrile 30 min gradient on C8 HPLC. Combined fractions and added sodium bicarbonate and evaporated organics in vacuo. The product, was partitioned between water/hexanes and the organics were dried over sodium sulfate, filtered and evaporated in vacuo to deliver (2S)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]undecan-2-amine (1). 1 H NMR (CDCl 3 , 300 mHz) δ 0.88-0.87 (m, 6 H), 1.285 (s, 33 H), 1.55(m, 2 H), 1.80 (m, 1 H), 2.00-2.05 (s, 4 H), 2.29-2.31 (2 H), 2.50 (m, 1 H), 2.76-1.77 (m, 2 H), 3.36-3.51(m, 6 H), 5.34-5.36 (m, 4 H); LC/MS (m+1)=464.9.
[0118] Compounds 3-11 are novel cationic lipids and were prepared according to General Scheme 1 above.
[0000] Compound Structure LC/MS (m + 1) 3 450.4 4 450.6 5 423.6 6 408.6 7 492.8 8 436.6 9 479.7 10 478.7 11 451.7
(2S)-N,N-dimethyl-1-[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]undecan-2-amine (Compound 12)
[0000]
[0119] A round bottomed flask was charged with magnetic stir bar, copper cyanide (1.45 g, 16.2 mmol), epichlorohydrin (15 g, 162 mmol) and purged with nitrogen. THF was added, the solution cooled to −78° C. and linoleyl Grignard (68.8 g, 195 mmol) was added slowly. After addition of Grignard the reaction was allowed to warm to ambient temperature. The reaction was quenched with saturated ammonium chloride solution and extracted with ether. The organics were dried over sodium sulfate, filtered and evaporated in vacuo. The intermediate chloro-alcohol was purified via flash chromatography (silica, 0-35% ethyl acetate/hexanes). The alcohol was dissolved in THF and allowed to stir with solid NaOH pellets at ambient temperature for 16 hours, then filtered off NaOH and washed organic layer with water. The organics were dried over sodium, sulfate, filtered and evaporated in vacuo to provide (2S)-2-[(10Z,13Z)-nonadeca-10,13-dien-1-yl]oxirane. 1 H NMR (CDCl 3 , 300 mHz) δ 0.87-0.90 (m, 3 H), 1.27-1.52 (m, 22 H), 2.01-2.19 (m, 4 H), 2.40-2.46 (m, 1 H), 2.71-2.76 (m, 3 H), 2.89-2.91 (m, 1 H), 5.30-5.36 (m, 4 H); LC/MS (m+H+acetonitrile)=349.5.
[0000]
[0120] The alcohol (2.55 g, 19.6 mmol) was dissolved in DCM and cooled to 0° C. To this solution was added tin chloride (1.63 mmol, 1.63 mL of a 1M solution). The epoxide (5 g, 16.3 mmol) was added to the reaction mixture dropwise and the reaction was aged for 1 hour at 0° C. The reaction was evaporated in vacuo, dissolved in hexanes and purified by flash chromatography (0-20% ethyl acetate/hexanes) to give (2R, 12Z,15Z)-1-(octyloxy)henicosa-12,15-dien-2-ol. LC/MS (m+H)= 437.6.
[0000]
[0121] The alcohol was carried on to final Compound 12 as described for Compound 1. 1 H NMR (CDCl 3 , 300 mHz) δ 0.85-0.091 (m, 6 H), 1.272 (s, 34 H), 1.46 (m, 1 H), 1.57(m, 1 H), 1.65 (s, 4 H), 2.01-2.08 (3 H), 2.30 (m, 6 H), 2.52 (m, 1 H), 2.75 -2.79 (m, 2 H), 3.29-3.4 (m, 2 H), 3.46-3.51 (dd, J=9.76 Hz, 1 H), 5.30-5.39 (m, 4 H); LC/MS (m+H)=464.7.
[0122] Compounds 13-16 are novel cationic lipids and were prepared according to General Scheme 2 above.
[0000] Compound Structure LC/MS (m + 1) 13 492.7 14 436.7 15 577.0 16 506.8
N,N-dimethyl-2-{[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]methyl} undecan-1-amine (Compound 17)
[0000]
[0123] To a solution of alcohol iii (15 g, 34.3 mmol) in dichloromethane (50 mL) was added Dess-Martin Periodinane (14.6 g, 343 mmol) and the reaction was stirred at ambient temperature for 16 hours. The solids were filtered and the filtrate partitioned between water/DCM. The organics were dried over sodium sulfate, filtered and evaporated, in vacuo. Purification by flash chromatography (silica, 0-15% ethyl acetate/hexanes) gave ketone vii. LC/MS (M+H)=435.6.
[0000]
[0124] To a solution of ketone vii (10 g, 23.0 mmol) in DME (40 mL) was added TOSMIC (5.8 g, 29.9 mmol) and the solution was cooled to 0° C. To the cooled solution was added potassium tert-butoxide (46 mmol, 46 mL of a 1M solution in tBuOH) dropwise. After 30 minutes the reaction was partitioned between hexanes and water. The organics were dried over sodium sulfate, filtered and evaporated in vacuo. Purification by flash chromatography (silica, 0-10% ethyl acetate/hexanes) gave nitrile viii. LC/MS (M+H)=446.6.
[0000]
[0125] To a solution of nitrile viii (4.6 g, 10.4 mmol) in THF (25 mL) was added lithium aluminum hydride (0.8 g, 20.7 mmol) at ambient temperature. The reaction was quenched with sodium sulfate decahydrate solution and the solids were filtered. The filtrate was dried over sodium sulfate, filtered and evaporated in vacuo to give crude amine ix which was carried directly into next reaction, LC/MS (M+H)=450.6.
[0000]
[0126] A solution of amine ix (4.7 g, 10.3 mmol) and formaldehyde (2.5 g, 31.1 mmol) in THF (25 mL) was treated with sodium, triacetoxyborohydride (6.6%, 31.1 mmol) at ambient temperature. After aging for 15 minutes, the reaction was quenched with 1M sodium hydroxide and partitioned between water and hexanes. The organics were dried over sodium sulfate, filtered and evaporated in vacuo. Purification by preparative reverse phase chromatography (C8 column, acetonitrile/water gradient) gave compound 17. LC/MS (M+H)=479.6. 1 H NMR (CDCl 3 , 400 mHz) δ 5.36 (m, 4H), 3.38 (m, 3H), 3.26 (m, 1H), 2.75 (t, J=6.4 Hz, 2H), 2.22 (m, 1H), 2.19 (s, 6H), 2.04 (m, 5H), 1.71 (m, 1H), 1.54 (m, 2H), 1.28 (m, 32H), 0.83 (m, 6H).
[0000] N,N-dimethyl-3-{[(9Z,12Z)-octadeca-9,12-dien-1-yloxy]methyl}dodecan-1-amine (Compound 18)
[0000]
[0127] A solution of silyl amide (12.4 g, 78 mmol) in THF (50 mL) was cooled to −78 ° C. and treated with nBuLi (62.4 mmol, 25 mL of a 2.5M solution) and aged for 10 minutes. To this solution was transferred ketone vii (12 g, 27.6 mmol) in a small portion of dry THF. The reaction was aged 15 minutes then warmed to ambient temperature, quenched with sodium bicarbonate solution and partitioned between water and hexanes. The organics were dried over sodium sulfate, filtered and evaporated in vacuo to give amide xi LC/MS (M+H)=505.6.
[0000]
[0128] Amide xi (7 g, 13.9 mmol) was treated with L-Selectride (55.6 mmol, 55.6 mL of a 1M solution) in a microwave vial. The reaction was sealed and irradiated in a microwave reaction set at 70° C. for 16 hours. The reaction was then diluted with dichloromethane and quenched by careful addition of sodium perborate solid until effervescence stopped. The solids were filtered and the filtrate evaporated in vacuo to give xii. LC/MS (M+H)=507.6.
[0000]
[0129] To a solution of amide xii (7 g, 13.8 mmol) in THF (30 mL) was added lithium aluminum hydride (1.1 g, 27.7 mmol). The reaction was quenched with sodium sulfate decahydrate solution and the solids filtered. The organics were evaporated in vacuo and the product purified by preparative reverse phase chromatography (CS column, acetonitrile/water gradient) to give compound 18. LC/MS (M+H)=493.6. 1 H NMR (CDCl 3 , 400 mHz) δ 5.38 (m, 4H), 3.38 (m, 2H), 3,26 (m, 2H), 2.78 (t, J=6.4 Hz, 2H), 2.25 (m, 8H), 2.04 (m, 4H), 1.56 (m, 4H), 1.29 (m, 32H), 0.89 (m, 6H).
[0000] (2S)-N,N-dimethyl-1-[(8-{2-[(2-pentylcyclopropyl)methyl]cyclopropyl}octyl)oxy]tridecan-2-amine (Compound 19)
[0000]
[0130] A solution of diene (24 g, 51.6 mmol) in dichloromethane (100 mL) was cooled to −15° C. To this solution was added diethyl zinc (310 mmol, 310 mL of a 1M solution) followed by diiodomethane (25 mL, 310 mmol) and the reaction was aged for 16 hours while slowly warming to ambient temperature. The reaction was quenched with ammonium chloride solution and partitioned between water and dichloromethane. The organics were dried over sodium sulfate, filtered and evaporated in vacuo. Purification by flash chromatography (silica, 0-25% ethyl acetate/hexanes) gave bis-cyclopropane intermediate xiv. LC/MS (M+H)=493.6.
[0000]
[0000] Compound xiv was carried on to final compound 19 as outlined for compound 1 above, LC/MS (M+H)=520.8.
[0131] Compound 20 is DLinKC2DMA as described in Nature Biotechnology, 2010, 28, 172-176, WO 2010/042877 A1, WO 2010/048536 A2, WO 2010/088537 A2, and WO 2009/127060 A1.
[0000]
[0132] Compound 21 is MC3 as described in WO 2010/054401, and WO 2010/144740
[0000]
LNP COMPOSITIONS
[0133] The following lipid nanoparticle compositions (LNPs) of the instant invention are useful for the delivery of oligonucleotides, specifically siRNA and miRNA:
Cationic Lipid/Cholesterol/PEG-DMG 56.6/38/5.4;
Cationic Lipid/Cholesterol/PEG-DMG 60/38/2;
Cationic Lipid/ Cholesterol/PEG-DMG 67.3/29/3.7;
[0134] Cationic lipid/Cholesterol/PEG-DMG 49.3/47/3,7;
Cationic Lipid/Cholesterol/PEG-DMG 50.3/44.3/5.4;
Cationic Lipid/Cholesterol/PEG-C-DMA/DSPC 40/48/2/10;
Cationic Lipid/Cholesterol/PEG-DMG/DSPC 40/48/2/10; and
Cationic Lipid/Cholesterol/PEG-DMG/DSPC 58/30/2/10.
LNP Process Description:
[0135] The Lipid Nano-Particles (LNP) are prepared by an impinging jet process. The particles are formed by mixing lipids dissolved in alcohol with siRNA dissolved in a citrate buffer. The mixing ratio of lipids to siRNA are targeted at 45-55% lipid and 65-45% siRNA. The lipid solution contains a novel cationic lipid of the instant invention, a helper lipid (cholesterol), PEG (e.g. PEG-C-DMA, PEG-DMG) lipid, and DSPC at a concentration of 5-15 mg/ml with a target of 9-1.2 mg/mL in an alcohol, (for example ethanol). The ratio of the lipids has a mole percent range of 25-98 for the cationic lipid with a target of 35-65, the helper lipid has a mole percent range from 0-75 with a target of 30-50. the PEG lipid has a mole percent range from 1-1.5 with a target of 1-6, and the DSPC has a mole percent range of 0-15 with a target of 0-12. The siRNA solution contains one or more siRNA sequences at a concentration range from 0.3 to 1 .0 mg/mL with a target of 0.3-0.9 mg/mL in a sodium citrate buffered salt solution with pH in the range of 3.5-5. The two liquids are heated to a temperature in the range of 15-40° C., targeting 30-40° C., and then mixed in an impinging jet mixer instantly forming the LNP. The teeID has a range from 0.25 to 1.0 mm and a total flow rate from 10-600 mL/min. The combination of flow rate and tubing ID has effect of controlling the particle size of the LNPs between 30 and 200 nm. The solution is then mixed with a buffered solution at a higher pH with a mixing ratio in the range of 1:1 to 1:3 vol:vol but targeting 1:2 vol:vol. This buffered solution is at a temperature in the range of 15-40° C., targeting 30-40° C. The mixed LNPs are held from 30 minutes to 2 hrs prior to an anion exchange filtration step. The temperature during incubating is in the range of 15-40° C., targeting 30-40° C. After incubating the solution is filtered through a 0.8 um filter containing an anion exchange separation step. This process uses tubing IDs ranging from 1 mm ID to 5 mm ID and a flow rate from 10 to 2000 mL/min. The LNPs are concentrated and diafiltered via an ultrafiltration process where the alcohol is removed and the citrate buffer is exchanged for the final buffer solution such as phosphate buffered saline. The ultrafiltration process uses a tangential flow filtration format (TFF). This process uses a membrane nominal molecular weight cutoff range from 30-500 KD. The membrane format can be hollow fiber or flat sheet cassette. The TFF processes with the proper molecular weight cutoff retains the LNP in the retentate and the filtrate or permeate contains the alcohol; citrate buffer; final buffer wastes. The TFF process Is a multiple step process with an initial concentration to a siRNA concentration of 1-3 mg/mL. Following concentration, the LNPs solution is diafiltered against the final buffer for 10-20 volumes to remove the alcohol and perform buffer exchange. The material is then concentrated an additional 1-3 fold. The final steps of the LNP process are to sterile filter the concentrated LNP solution and vial the product.
Analytical Procedure:
[0136] 1) siRNA Concentration
[0137] The siRNA duplex concentrations are determined by Strong Anion-Exchange High-Performance Liquid Chromatography (SAX-HPLC) using Waters 2695 Alliance system (Water Corporation, Milford Mass.) with a 2996 PDA detector. The LNPs, otherwise referred to as RNAi Delivery Vehicles (RDVs), are treated with 0.5% Triton X-100 to free total siRNA and analyzed by SAX separation using a Dionex BioLC DNAPac PA 200 (4×250 mm) column with UV detection at 254 nm. Mobile phase is composed of A: 25 mM NaClO 4 , 10 mM Tris, 20% EtOH, pH 7.0 and B: 250 mM NaClO 4 , 10 mM Tris, 20% EtOH, pH 7.0 with liner gradient from 0-15 min and flow rate of 1 ml/min. The siRNA amount is determined by comparing to the siRNA. standard curve.
2) Encapsulation Rate
[0138] Fluorescence reagent SYBR Gold is employed for RNA quantitation to monitor the encapsulation rate of RDVs. RDVs with or without Triton X-100 are used to determine the free siRNA and total siRNA amount. Tire assay is performed using a SpectraMax M5e microplate spectrophotometer from Molecular Devices (Sunnyvale, Calif.). Samples are excited at 485 nm and fluorescence emission was measured at 530 nm. The siRNA amount is determined by comparing to the siRNA standard curve.
[0000] Encapsulation rate=(1=free siRNA/total siRNA)×100%
3) Particle Size and Polydispersity
[0139] RDVs containing 1 μg siRNA are diluted to a final volume of 3 ml with 1×PBS. The particle size and polydispersity of the samples is measured by a dynamic light scattering method using ZetaPALS instrument (Brookhaven Instruments Corporation, Holtsville, N.Y.). The scattered intensity is measured with He—Ne laser at 25° C. with a scattering angle of 90°.
4) Zeta Potential Analysis
[0140] RDVs containing 1 μg siRNA are diluted to a final volume of 2 ml with 1 mM Tris buffer (pH 7.4). Electrophoretic mobility of samples is determined using ZetaPALS instrument (Brookhaven Instruments Corporation, Holtsville, N.Y.) with electrode and He—Ne laser as a light source. The Smoluchowski limit is assumed in the calculation of zeta potentials.
5) Lipid Analysis
[0141] Individual lipid concentrations are determined by Reverse Phase High-Performance liquid Chromatography (RP-HPLC) using Waters 2695 Alliance system (Water Corporation, Milford Mass.) with a Corona charged aerosol detector (CAD) (ESA Biosciences, Inc, Chelmsford, Mass.). Individual lipids in RDVs are analyzed, using an Agilent Zorbax SB-CIS (50×4.6 mm, 1.8 μm particle size) column with CAD at 60° C. The mobile phase is composed of A: 0.1% TFA in H 2 O and B: 0.1% TFA in IPA. The gradient changes from 60% mobile phase A and 40% mobile phase B from time 0 to 40% mobile phase A and 60% mobile phase B at 1.00 min; 40% mobile phase A and 60% mobile phase B from 1.00 to 5.00 min; 40% mobile phase A and 60% mobile phase B from 5.00 min to 25% mobile phase A and 75% mobile phase B at 10.00 min; 25% mobile phase A and 75% mobile phase B from 10.00 min to 5% mobile phase A and 95% mobile phase B at 15.00 min; and 5% mobile phase A and 95% mobile phase B from 15.00 to 60% mobile phase A and 40% mobile phase B at 20.00 min with flow rate of 1 ml/min. The individual lipid concentration is determined by comparing to the standard curve with all the lipid components in the RDVs with a quadratic curve fit. The molar percentage of each lipid is calculated based on its molecular weight.
[0142] Utilizing the above described LNP process, specific LNPs with the following ratios were identified:
Nominal Composition:
Cationic Lipid/Cholesterol/PEG-DMG 60/38/2
Cationic Lipid/Cholesterol/PEG-DMG/DSPC 58/30/2/10
[0143]
[0000]
Luc siRNA
5′-iB- A U AAGG CU A U GAAGAGA U ATT -iB 3′
(SEQ.ID.NO: 1)
3′-UU U A UUCC GA U A CUUCUC UAU -5′
(SEQ.ID.NO: 2)
AUGC - Ribose
iB - Inverted deoxy abasic
UC - 2′ Fluoro
AGT - 2′ Deoxy
AGU - 2′ OCH 3
Nominal Composition
Cationic Lipid /Cholesterol/PEG-DMG 60/38/2
Cationic Lipid/Cholesterol/PEG-DMG/DSPC 40/48/2/10
Cationic Lipid/Cholesterol/PEG-DMG/DSPC 58/30/2/10
[0144]
[0000]
ApoB siRNA
5′-iB-CUUU AA C AA UUCCU GAAA U TsT -iB-3′
(SEQ ID NO.: 3)
3′-UsU GAAA U UG UU AAGGA CUs UsUsA -5′
(SEQ ID NO.: 4)
AUGC - Ribose
iB - Inverted deoxy abasic
UC - 2′ Fluoro
AGT - 2′ Deoxy
AGU - 2′ OCH 3
UsA - phophorothioate linkage
Example 1
[0145] Mouse In Vivo Evaluation of Efficacy
[0146] LNPs utilizing Compounds 1-12, in the nominal compositions described immediately above, were evaluated for in vivo efficacy. The siRNA targets the mRNA transcript for the firefly ( Photinus pyralis ) luciferase gene (Accession #M15077). The primary sequence and chemical modification pattern of the luciferase siRNA is displayed above. The in vivo luciferase model employs a transgenic mouse in which the firefly luciferase coding sequence is present in all cells. ROSA26-LoxP-Stop-LoxP-Luc (LSL-Luc) transgenic mice licensed from the Dana Farber Cancer Institute are Induced to express the Luciferase gene by first removing the LSL sequence with a recombinant Ad-Cre virus (Vector Biolabs). Due to the organotropic nature of the virus, expression is limited to the liver when delivered via tail vein injection. Luciferase expression levels in liver are quantitated by measuring light output, using an IVIS imager (Xenogen) following administration of the luciferin substrate (Caliper Life Sciences). Pre-dose luminescence levels are measured prior to administration of the RDVs. Luciferin in PBS (15 mg/mL) is intraperitoneally (IP) injected in a volume of 150 μL. After a four minute incubation period mice are anesthetized with isoflurane and placed in the IVIS imager. The RDVs (containing siRNA) in PBS vehicle were tail vein injected n a volume of 0.2 mL. Final dose levels ranged from 0.1 to 0.5 mg/kg siRNA. PBS vehicle alone was dosed as a control. Mice were imaged 48 hours post dose using the method described above. Changes in luciferin light output directly correlate with luciferase mRNA levels and represent an indirect measure of luciferase siRNA activity. In vivo efficacy results are expressed as % inhibition of luminescence relative to pre-dose luminescence levels. Systemic administration of the luciferase siRNA RDVs decreased luciferase expression in a dose dependant manner. Greater efficacy was observed in mice dosed with Compound 1 containing RDVs than with the RDV containing the octyl-CLinDMA (OCD) cationic lipid ( FIG. 1 ). OCD is known and described in WO2010/021865.
Example 2
Rat In Vivo Evaluation of Efficacy and Toxicity
[0147] LNPs utilizing compounds in the nominal compositions described above, were evaluated for in vivo efficacy and increases in alanine amino transferase and aspartate amino transferase in Sprague-Dawley (Crl:CD(SD) female rats (Charles River Labs). The siRNA targets the mRNA transcript for the ApoB gene (Accession #NM 019287). The primary sequence and chemical modification pattern of the ApoB siRNA is displayed above. The RDVs (containing siRNA) in PBS vehicle were tail vein injected in a volume of 1 to 1.5 ml. Infusion rate is approximately 3 ml/min. Five rats were used in each dosing group. After LNP administration, rats are placed in cages with normal diet and water present. Six hours post dose, food is removed from the cages. Animal necropsy is performed 24 hours after LNP dosing. Rats are anesthetized under isoflurane for 5 minutes, then maintained under anesthesia, by placing them in nose cones continuing the delivery of isoflurane until ex-sanguination is completed. Blood is collected from the vena cava using a 23 gauge butterfly venipuncture set and aliquoted to serum separator vacutainers for serum chemistry analysis. Punches of the excised caudate liver lobe are taken and placed in RNALater (Ambion) for mRNA analysis. Preserved liver tissue was homogenized and total RNA isolated using a Qiagen bead mill and the Qiagen miRNA-Easy RNA isolation kit following the manufacturer's instructions. Liver ApoB mRNA levels were determined by quantitative RT-PCR. Message was amplified from purified RNA utilizing a rat ApoB commercial probe set (Applied Biosystems Cat #RN01499054_ml). The PCR reaction was performed on an ABI 7500 instrument with a 96-well Fast Block. The ApoB mRNA level is normalized to the housekeeping PPIR (NM 011149) mRNA. PPIB mRNA levels were determined by RT-PCR using a commercial probe set (Applied Biosytems Cat. No. Mm00478295_ml). Results are expressed as a ratio of ApoB mRNA/PPIB mRNA. All mRNA data is expressed relative to the PBS control dose. Serum ALT and AST analysis were performed on the Siemens Advia 1800 Clinical Chemistry Analyzer utilizing the Siemens alanine aminotransferase (Cat#03039631) and aspartate aminotransferase (Cat#03039631.) reagents. Similar efficacy was observed in rats dosed with Compound 1 containing RDV than with the RDV containing the cationic lipid DLinKC2DMA (Compound 20) or MC3 (Compound 21, FIG. 2 ). Additionally, 3 out of 4 rats treated with 3 mg/kg DLinKC2DMA (Compound 20) failed to survive 48 hours and 2 out of 4 rats treated with 3 mg/kg MC3 (Compound 21) failed to survive 48 hours, 1 out of 4 rats treated with 10 mg/kg Compound 1 survived at 48 hours post dose.
Example 3
Determination of Cationic Lipid Levels in Rat Liver
[0148] Liver tissue was weighed into 20-ml vials and homogenized in 9 v/w of water using a GenoGrinder 2000 (OPS Diagnostics, 1600 strokes/min, 5 min). A 50 μL aliquot, of each tissue homogenate was mixed with 300 μL of extraction/protein precipitating solvent (50/50 acetonitrile/methanol containing 500 nM internal standard) and the plate was centrifuged to sediment precipitated protein. A volume of 200 μL of each supernatant was then transferred to separate wells of a 96-well plate and 10 μl samples were directly analyzed by LC/MS-MS.
[0149] Standards were prepared by spiking known amounts of a methanol stock solution of compound into untreated rat liver homogenate (9 vol water/weight liver). Aliquots (50 μL) each standard/liver homogenate was mixed with 300 μL of extraction/protein precipitating solvent (50/50 acetonitrile/methanol containing 500 nM internal standard) and the plate was centrifuged to sediment precipitated protein. A volume of 200 μL of each supernatant was transferred to separate wells of a 96-well plate and 10 μl of each standard was directly analyzed by LC/MS-MS.
[0150] Absolute quantification versus standards prepared and extracted from liver homogenate was performed using an Aria LX-2 HPLC system (Thermo Scientific) coupled to an API 4000 triple quadrupole mass spectrometer (Applied Biosystems). For each run, a total of 10 μL sample was injected onto a RDS Hypersil C8 HPLC column (Thermo, 50×2 mm, 3 μm) at ambient temperature.
[0151] Mobile Phase A: 95% H 2 O/5% methanol/10 mM ammonium formate/0.1 % formic acid Mobile Phase B: 40% methanol/60% n-propanol/10 mM ammonium formate/0.1 % formic acid. The flow rate was 0.5 mL/min and gradient elution profile was as follows: hold at 80% A for 0.25 min, linear ramp to 100% B over 1.6 min, hold at 100% B for 2.5 min, then return and hold at 80% A for 1.75 min. Total runtime was 5.8 min. API 4000 source parameters were CAD: 4, CUR: 15, GS1: 65, GS2: 35, IS: 4000, TEM: 550, CXP: 15, DP: 60, EP: 10. In rats dosed with Compound 1 containing RDV liver levels were lower than with the RDV containing the cationic lipid DLinKC2DMA (Compound 20) or MC3 (Compound 21, FIG. 3 ).
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The instant invention provides for novel cationic lipids that can be used in combination with other lipid components such as cholesterol and PEG-lipids to form lipid nanoparticles with oligonucleotides. It is an object of the instant invention to provide a cationic lipid scaffold that demonstrates enhanced efficacy along with lower liver toxicity as a result of lower lipid levels in the liver. The present invention employs low molecular weight cationic lipids with one short lipid chain to enhance the efficiency and tolerability of in vivo delivery of siRNA.
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STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.
FIELD OF THE INVENTION
This invention pertains to the field of flares, and more particularly to the construction of the flare case for naval decoy flares for the protection of aircraft and other potential targets from hostile missiles and aircraft that target infrared energy. This field includes explosive cases of infrared flares, illumination flares or flares designed to emulate the infrared, visible light and or electromagnetic signature of an airborne missile, space craft or aircraft.
BACKGROUND OF THE INVENTION
Naval aviation has always had special requirements for aircraft and weapon systems and their countermeasure equipment not required by the United States military counterpart systems in the other services. These increased requirements, result in part from the tremendous forces generated by aircraft operating from a carrier deck. In aircraft operating from a carrier deck the force of a catapult boost to the platform and weapon system on take off and rapid de-acceleration of a tail hook arrested landing increase strength requirements. Also naval countermeasure systems are often stored on deployed ships where physical strength requirements are higher due to the more hostile corrosive and physical environment of a sea-going vessel.
The Navy has historically used cylindrical decoy flare containers while the Air Force and Army Air Corps used rectangular or square flare cases. Now when faced with increased standardization requirements between the services, the Navy is required to adapt some of the square or rectangle flares for naval use and these standardized flares must pass stringent naval safety and handling testing. Past testing of rectangular or square cased flares exhibited the end caps lacking the strength to contain the energetic material under the increased naval requirements. Various means to increase the push out force on the end caps have been tried and tested but generally increasing the push out force necessary to open the end cap also increases the pressure necessary to properly release the encapsulated payload when the impulse cartridge fires.
Staking, side crimps and end cap tabs have been tested as a possible solution to the problem but all have failed to increase the push out force required for naval testing parameters without increasing the vulnerability to water intrusion and corrosion. Pinning can meet the increased push out force but creates holes in the flare case that exacerbates the entry of water and increases damage from the corrosive naval operating environment and increases assembly costs. Magneforming has shown promise as a possible solution but is prohibitively expensive.
Consequently, a need remains for a reliable, safe construction technique for square, rectangular or cylindrical decoy flare cases which exhibit the increased push out force required for naval testing parameters while still meeting the release requirements upon firing, that is not prohibitively expensive.
SUMMARY OF THE INVENTION
An object of the invention is to provide an improved decoy flare of rectangular or square construction that increases the push out force necessary to keep a payload containment cap in place and thus avoids releasing the payload without firing the flare.
Another object of the present invention is to teach a standardized case for energetic infrared, visible light or electromagnetic flares that meet all services testing requirements.
Another object of the invention is to provide a flare case that avoids water intrusion apertures and thus increases corrosion resistance.
A still further object of the present invention is to provide a case improvement for square or rectangular flares that allows decoy flares produced by the various United States and NATO military services to pass the differing service test requirements for safety, ease of release, interoperability and standardization.
A further object of the present invention is to teach a flare case and payload containment cap for variously shaped flares that can be sealed with a sealant to reduce the possibility of water intrusion.
Another object of the present invention is to teach a decoy flare that has the increased strength necessary to avoid accidental release of the payload during storage, handling, and carrier operations without prohibitive increased manufacturing costs.
A further object of the present invention is to teach a case construction that can be employed in the new decoy flares currently under development, e.g., the MJU-53/B and MJU-61/B being designed for cross service use.
Still another object of the instant invention is to disclose a decoy flare that can pass the demanding safety and corrosion testing for naval shipboard operation without increasing the force required for releasing the payload containment cap beyond allowable levels upon firing the flare.
Another object on the instant invention is to teach a payload containment cap and means of affixing the cap within a flare case that allows for placement of the payload containment cap at any depth within the flare case thus accommodating different size payloads in a standard flare case.
A further object is to teach a flare case and payload containment cap that can be firmly held in place at any point within the flare case by indents impinged into the case whereby the payload containment cap is firmly affixed between indents and movement both outward or inward is avoided.
In accomplishing these and other objectives and features of the invention there is provided a cylindrical, rectangular or square flare case that uses a payload containment cap held in place by crimping the case at one or more corners or at measured spacing around a cylindrical case. One variation presses the case inward at one or more of the case corners to extend over the top of the payload containment cap, resulting in an increase of force required to force the cap off and release the payload. Another variation indents the case at one or more of the case corners in a way that the case is deformed inward and over the top of the payload containment cap thereby increasing the internal pressure necessary to force the cap off of the flare case. Another embodiment using a cylindrical case flare places crimps at a 120 degree spacing around the top perimeter resulting in three crimps per case. Still another embodiment of the present invention uses pairs of indents impinged in place at a desired depth in the flare case thus holding the payload containment cap from moving outward or inward, and allows placement of the payload containment cap at any distance within the flare case. The depth of the indenture or corner crimp may be varied so as to regulate the pressure required to jettison the end cap upon firing of the impulse cartridge when the flare is used. In general, cylindrical flares with standard end caps result in a higher internal release pressure found adequate in naval safety testing but the teachings of the present invention could be easily adapted to a cylindrical flare case where one wished to increase release pressure required to remove the end cap. The construction of flare cases taught by the instant disclosures can be used with silicone or other sealant known to those skilled in the art to reduce the possibility of water intrusion and increase corrosion control. It has also been shown advantageous to place a rubber pad between the payload containment cap and the payload thus reducing abrasive wear or shock in handling and storage.
The corner crimp technique is a new feature considered an advantage over most existing crimps in that they will retain heavier payloads in rectangular and square cases. The corner crimps also withstand environmental and durability tests without problems. The crimps are easily adjustable. The retaining force can be adjusted by changing the crimp angles and depths. The tooling required to produce the crimp is inexpensive and can be teamed with hydraulic, air or arbor presses.
BRIEF DESCRIPTION OF THE DRAWINGS
Having summarized the invention, a detailed description follows with reference being made to the accompanying drawings that form part of the specification, of which:
FIG. 1 is a view of a non-cylindrical flare case showing the corner crimps of the present invention.
FIG. 2 is a closer view of the flare case of FIG. 1 that more clearly shows the impinged crimps at each corner of flare case 10 .
FIG. 3 is a view of the upper portion of a flare case shown with the payload containment cap held in place by the corner crimps of the present invention.
FIG. 4 is the top of a flare case having the signature corner crimps further enhanced with a silicone sealant.
FIG. 5 is the upper portion of a rectangular flare case delineating the indented case of one embodiment of the present invention.
FIG. 6 is a view of the case of FIG. 5 shown in proximity to a sealable payload containment cap.
FIG. 7 is a view of one end of the flare case of FIG. 6 with the payload containment cap shown held in place with the corner indentures.
FIGS. 8 a, b and c show stress vectors for the various geometrical shapes of the flare cases employing the present invention.
FIG. 9 teaches a dual stage flare case with two payloads separated by a payload containment cap.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings a flare case indicated generally by the referenced numeral 10 is shown in various views. This flare case 10 may be of various shapes both cylindrical and other geometrical construction such as square, rectangular and triangular. The current invention is intended specifically to solve interoperability problems required to adapt Air Force and Army Air Corps flares to the more vigorous operating environment of the United States Navy and the drawings will concentrate on those case designs. It should be understood that while a cylindrical flare case design has generally been shown to have adequate strength and has historically been used by the US Navy, the present invention can be adapted with any cylindrical flare. When payload release force needs to be increased or where the payload is smaller than the flare case requiring the payload containment cap to be positioned within the case rather than at the end, the present invention can accommodate the changes. The preferred embodiment of both the indented and crimped flare case of the disclosed invention is with non-cylindrically shaped flare cases requiring payload containment cap release strengths beyond that obtained with a smooth case construction.
Turning now to FIG. 1 a case 10 is shown in a flare case of rectangular design with crimps 11 located on each of the four corners. The flare case of FIG. 1 shows the flare containment case to have a launcher and firing circuit end 14 and a payload release end 15 . Crimps 11 are placed at each corner so as to stress the material at a high strength point before the crimps release. Crimps 11 , placed at the top of each corner, are more effective and can be made much stronger than when crimps 11 are placed along the sides of a rectangle case, as the material along the sides has a tendency to flex and render the crimps ineffective or erratic with the amount of force required to release. Another embodiment of the present invention might place crimps 11 only on one pair of the diagonally opposing corners. This technique would attenuate the force required for the release of a payload. Likewise, the size of the crimp would intuitively affect the amount of force required for release.
FIG. 2 is a closer view of the flare case of FIG. 2 that more clearly shows the impinged crimps at each corner of flare case 10 .
FIG. 3 shows a flare case 10 with a flare payload containment cap 20 having a recessed lip 21 which is under the crimps 11 when the top is assembled and crimped into place.
FIG. 4 shows the flare case 10 of FIG. 3 with an application of sealant 12 sealing the case 10 with the cap 20 so as to avoid any aperture for moisture intrusion. Any sealant may be used but a silicone sealant tested provided good results and is anti corrosive.
FIG. 5 shows a rectangular flare case where indentations are pressed into the case. These indentations extend into the case but do not puncture the flare case 10 .
FIG. 6 shows case 10 of FIG. 5 with a corresponding payload containment cap or top 20 having a perimeter 21 . The flare case payload containment cap 20 is further defined by a recessed lip 24 around the perimeter 21 operatively sized to accommodate one or more indentations 13 when the case payload containment cap 20 is in place within the flare containment case perimeter 21 . The corner of the cap 20 may be beveled, creating bevels 22 that correspond with indentations 13 when top 20 is in place whereby the inwardly depending indentations 13 snugly fit over the top of the bevels 22 and hold top 20 firmly in place on case 10 . The extent of the indentation 13 will vary the force required to jettison the top 20 and release a payload.
FIG. 7 shows the flare case of FIG. 6 assembled. As taught in conjunction with FIG. 4, a layer of sealant may be used to seal top 20 to case 10 and avoid water intrusion.
It is important to note that the invention may be practiced with many embodiments not particularly shown in the figures. Theoretically, a flare case may be manufactured in any geometric shape and the crimping and indentations of the present inventions may be employed on any flare case and the position and number may be varied to change the jettison force required to remove the flare cover when an impulse cartridge is fired. The indents impinged in the flare case may be positioned in pairs thus trapping a payload containment cap in place at any desired depth within the flare case. Another embodiment could contain one smaller payload held in place with a payload containment cap within the flare case and a second payload held in place with a payload containment cap at the release end of the flare case allowing for multistage flare packages.
Two different corner crimp variations have been designed and tested. Both a corner indented embodiment and a corner crimped embodiment worked well, retaining the payload as required and releasing the payload when the flare is functioned. The first corner crimp design tested was the version in FIG. 1 . The corners of the metal flare case are bent down at an angle by press tooling. The depth and angle of the crimped corners help determine the retaining forces on the payload containment cap that in turn holds the payload in place. The material used in the fabrication of the containment cap also plays a large role in determining the retaining force of the crimp. The payload containment cap 20 denoted in the drawings may be manufactured out of any material and both metal and plastic caps were tested. If a plastic payload containment cap is used, the corners of the end cap will deform as the cap is pushed past the crimp.
FIG. 9 teaches a dual stage flare case 10 with standard corner crimps 11 for firmly containing the payload containment cap in place on the flare release end of the case. It also shows indents 13 located in pairs and operatively spaced so as to trap a payload containment cap in position holding a payload in place at the firing end of case 10 allowing another payload to be encased and held in place by the crimps 11 at the release end.
The corner crimps work well in rectangular and square cases because they take advantage of the material strength of the crimped items. FIG. 8 a , FIG. 8 b and FIG. 8 c illustrate force vectors on different shaped cases. FIG. 8 a shows arrows in side locations of a rectangular profile. Forces in these locations can easily flex a thin walled case and make crimps at these locations ineffective. FIG. 8 b shows force vectors pointing outward from the center of a circular case profile. Forces in these locations are resisted by the hoop strength of the case material. Therefore, crimps on the perimeter of a cylinder tend to be very strong. FIG. 8 c shows force arrows at corner locations of a rectangular case profile. Crimps put in the four corners of such a profile also tend to be very strong, more like the strength exhibited by a cylindrical case embodiment where the hoop strength of the material is stressed before the crimps release.
The corner crimp can be varied in numerous ways in order to obtain payload retainment/release requirements. The two ways illustrated in the drawings have both been extensively tested and work well. While the payload containment cap push out forces depend on a variety of factors, the containment cap material plays a large role. With thicker walled cases, the crimps tend to retain their shape, requiring the corners of the end cap to deform to allow the end cap to pass the crimps and release the payload. The angle and depth at which the crimp and payload containment cap corners engage also affect cap push out forces. These can be adjusted in a variety of ways to suit the particular application.
Reasonable other variations and modifications of the above described flare case are possible within the scope of the foregoing description, the drawings and the appended claims to the invention.
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A flare containment case is taught wherein the case has a end cap which is crimped into the sealed position with variously spaced crimps or indentations which may be machined in such a way as to increase and control the end cap release pressure.
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FIELD OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a cover (module cover) for an air bag system for protecting occupant by opening at the time of a collision or so of a car.
In the air bag system, the folded air bag is attached to a mounting plate called as a retainer, and the air bag is covered by the cover. The cover is also attached to the retainer similarly.
Further, an inflator is attached to the retainer directly or through an appropriate mounting member, and the inflator discharges a gas when collision of a car occurs to open the air bag immediately.
The cover the air bag system which is attached to steering wheel of the car is a box type having a side wall and canopy. Further, as the side wall and canopy, a reinforced material by burying or adding a reinforcement such like a network member of synthetic fiber, a thin metal plate, and a synthetic resin plate, can be used.
A starting line (tear line) for a cleavage of the cover when the air bag opens, is provided on the cover. In the tear line portion, the strength is lower than that of the surrounding portion, and the tear line is formed in the state of fixed linear shape. The cover cleaves along the tear line when the air bag opens.
One example of the conventional air bag system is explained based on FIGS. 4 and 5.
In FIG. 4, a retainer 10 has a cover mounting member comprising a plate member 14 to which an air bag 12 is attached and a standing piece 16 for standing to the opposite direction of the occupant from the edge of the plate member 14. The air bag 12 is covered by a module cover 10 in the state of folding, and a base side of the cover 18 is fixed by means of a rivet 20 relative to the standing piece 16. A reinforcement (not shown) is buried in the cover by an insert molding method. 22 is an inflator and is fixed on the retainer 10 so that the top side of the inflator projects into the air bag 12 through an opening 24 formed in the plate member 14. 26 is a ring and an edge portion of the opening of the air bag 12 is sandwiched between the ring 26 and the edge portion of the opening 24 of the plate member 14. Whereby, the air bag 12 is fixed on the retainer 10. 28 is a tear line provided on the cover 18.
According to the air bag system as mentioned above, if the inflator 22 actuates in response to the collision of the car, a large amount of gas is discharged from the inflator 22 immediately to open the air bag 12. In accordance with the opening of the air bag 12, as shown in FIG. 5, the cover 18 cleaves along the tear line 28, and the air bag 12 opens within the car immediately to achieve the protection of the occupant.
Since the cover is essentially composed of a synthetic resin, it has a flexibility. further, the conventional reinforcement buried or added to the cover is also a network member of synthetic fiber, thin metal plate, and synthetic resin plate, it has a flexibility. Therefore, as shown in FIG. 5, although a cleavage piece 18a reaches at the state as shown in a just after the air bag 12 opens, the cleavage piece 18a is going to return to the position as shown in a' by an elasticity of itself soon. Accordingly, the air bag 12 is lifted to the direction of the occupant by the force of the cleavage piece 18a which is going to return to the original position (A and B in the drawings) when the air bag 12 opens.
OBJECT AND SUMMARY OF THE INVENTION
The object of the present invention is to provide an improved cover an air bag system, in which the air bag opens to all directions immediately and largely since the cleavage piece of the cover can hold the deformation at the time of when the air bag opens.
The feature of the present invention is to bury or add a plastic deformation member.
In the cover for air bag system of the present invention, if the cover cleaves and deforms at the time of when the air bag opens, the cleavage piece formed becomes easy to hold the shape after the deformation by the plastic deformation member. Therefore, the module cover remains in the state in which the module cover cleaves largely, and the air bag can open to all directions immediately and widely.
In the present invention, the plastic deformation member is preferably to have a plate shape. However, a wire type and tape type can be used. Further, in all of the plastic deformation member of the plate type, the member may have a large number of holes such like a punching metal, and a smaller hole. What is preferable is that a through hole of a rivet for fixing the cover on the retainer is provided on the plate type plastic deformation member.
As the plastic deformation member of the present invention, a metal, a synthetic resin, and metal ceramic composites (cermet) are most suitable. In view of a corrosion-resistant, although aluminum, copper, nickel, and an alloy thereof are cited as the desirable material, a stainless can be also used. Furthermore, iron with anticorrosive material is also suitable for use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of the air bag system using the cover of one embodiment of the present invention.
FIG. 2 is a perspetive view for showing an arrangement of the reinforcement on the cover of the present invention.
FIG. 3 is an illustration for showing operation of the air bag system of the present invention.
FIG. 4 is a vertical sectional view of the conventional air bag system.
FIG. 5 is an illustration for explaining operation of the conventional air bag system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, the embodiments of the present invention are explained.
FIG. 1 is a sectional view of the air bag system using the cover of one embodiment of the present invention. FIG. 2 is a perspective view for showing the arrangement of the reinforcement of the cover. FIG. 3 is a sectional view for showing a deformation when the cover opens.
A cover 18 of the air bag system is the cover which is attached to a steering wheel. The cover 18 has a box shape having a side wall 18A and canopy 18B and is essentially composed of a synthetic resin, and a network member 30 for reinforcing is the cover is buried in the side wall 18A and canopy 18B. The network member 30 is divided into four pieces and is arranged so that a gap between each network member corresponds to a tear line 28.
The other marks of FIG. 1 indicate the same member in the conventional example, respectively.
In the cover for air the bag system or the air bag system providing the cover as mentioned above, if the inflator 22 actuates to open the air bag 12, the cover 18 cleaves along the tear line 28, thereby opening the air bag 12 within the car. At this time, since the cleavage piece 18a of the cover holds deformed posture by a plastic deformation member 32, the air bag 12 can open immediately and widely.
As the above plastic deformation member, a metal material having a high plastic deformability is suitable for the use.
In the above mentioned embodiment, the inflator is directly attached to the retainer. However, it is possible to apply the present invention to the cover for the air bag system in which the inflator is attached to the retainer through an appropriate member. Further, the present invention can be used for the cover for the air bag system other than the type which is attached to the steering wheel, for example, for an assistant driver's seat.
In the present invention, the network member 30 is preferable to be composed of a synthetic fiber, a metal fiber, or other fibers similar to these two. In stead of the network member 30, it is clear that a material having capable of reinforcing the cover such like a thin metal plate and synthetic resin plate can be used.
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A cover for air bag system in which a plastic deformation member is buried or added in order to hold a deformation state when the cover cleaves and deforms by opening the air bag.
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This is a continuation of Ser. No. 08/612,621, filed Mar. 6, 1996.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to methods used to fabricate semiconductor devices, and more specifically to processes used to improve the electrical contact between metal filled vias and metal interconnect structures.
(2) Description of Prior Art
The semiconductor industry is continually striving to improve the performance of silicon devices and circuits, while still attempting to maintain, or decrease the manufacturing cost of silicon chips, comprised of these higher performing silicon devices and circuits. Micro-miniaturazation, or the ability of the semiconductor industry to create silicon devices with sub-micron features, has allowed the performance, as well as the cost, objectives to be met. Sub-micron device features result in performance improvements via decreases in parasitic capacitances, and resistances. In addition smaller device features allow the silicon chip size to be reduced, resulting in a greater number of silicon chips to be realized from a specific size substrate, thus reducing the manufacturing cost of a specific chip. The attainment of micro-miniaturazation has been highlighted by advances in specific semiconductor fabrication disciplines, such as photolithography, as well as reactive ion etching. The development of more sophisticated exposure cameras, as well as the use of more sensitive photoresist materials, have allowed sub-micron images in photoresist layers to be routinely achieved. In addition, advances in dry etching, or reactive ion etching, (RIE), have allowed the sub-micron images in photoresist layers to be successfully transferred to underlying materials, used for the fabrication of advanced silicon devices.
The use of sub-micron features, although allowing the performance and cost objectives of the semiconductor industry to be realized, does present specific fabrication problems, not encountered for the fabrication of silicon devices using less aggressive designs. For example conventional approaches restrict the size of a contact or via, so that it comfortably falls on an underlying metal structure. This fully landed contact, or via, is usually made smaller than the width of the underlying metal structure by the amount of photolithographic misalignment allowed in the process. To take advantage of the micro-miniaturazation breakthroughs, these contacts or vias are now created with sub-micron dimensions. This brings about the problem of filling sub-micron vias with metal. The use of chemically vapor deposited tungsten, to fill sub-micron vias, is being used for via fills, taking advantage of the ability of tungsten to sustain high current densities without risking electromigration failure. However the mechanism of filling narrow diameter holes with CVD metals, results in a seam or void, at the center of the metal fill. This seam or void, when subjected to subsequent process steps, such as dry etching, used to form a metal plug in the narrow diameter hole, can evolve into a defect that can result in topology problems for subsequent overlying metallization structures. Many solutions for the metal seam phenomena have been described. For example Cheffings, et al, in U.S. Pat. No. 5,387,550, describe a process for filling voids or seams, in tungsten filled contact holes, with silicon. Marangon, et al, in U.S. Pat. No. 5,407,861, describe a process for minimizing the seam, by using a novel etch back process, to create the tungsten plug, without subjecting the exposed seam to additional dry etching procedures.
The process described in this invention will use a different approach. This invention will show a method of maintaining packing densities by reducing the size of the underlying metal structure, while increasing the size of the overlying metal filled via. The amount of contact area between the overlying metal filled via, and the underlying metal structure, is increased by removal of some passivation insulator from the sides of the underlying metal structure, making these exposed sides available for contact from the subsequent overlying, metal filled via. This approach, of using wider metal filled vias, reduce the seam problem, encountered with narrower via counterparts.
SUMMARY OF THE INVENTION
It is an object of this invention to fabricate silicon devices comprised of metal filled contact or vias, larger in width then the width of underlying interconnect metallization structure.
It is another object of this invention to open a contact or via, in a dielectric layer, that has been planarized via chemical-mechanical polishing procedures.
It is still another object of this invention to open a contact or via, in a dielectric layer, to expose the top surface of the underlying interconnect metallization structure.
It is yet another object of this invention to increase the contact area, between a subsequent metal filled via, and an underlying interconnect metallization structure, by continuing to remove dielectric layer material, and exposing a top portion of sides of the interconnect metallization structure.
It is still yet another object of this invention to fill the opened contact or via, with metal, contacting the top surface, as well as the sides of the underlying interconnect metallization structure.
In accordance with the present invention a method is described for fabricating a metal filled contact or via, larger in width then the width of an underlying interconnect metallization structure, and contacting the top surface, as well as the sides of the underlying interconnect metallization structure. A first dielectric layer is deposited on an underlying silicon device structure, followed by the opening of contact holes to active device regions of the underlying silicon device structure. A first metal layer is deposited, completely filling the opened contact holes, and patterned to form a first level interconnect metallization structure. A second dielectric layer is deposited on the first level interconnect metallization structure, as well as on the regions of underlying first dielectric layer, not covered by the first level interconnect metallization structure. A chemical-mechanical polishing procedure is performed to planarize the second dielectric layer. Photolithographic and dry etching procedures are next employed to open a hole in the second dielectric layer, to expose the top surface of the underlying first level interconnect metallization structure, with the opening in the second dielectric layer, larger in width then the width of the first level interconnect metallization structure. The dry etching procedure is then continued to remove additional second dielectric layer material, recessing the opened hole, to expose the top part of the sides of the first level interconnect metallization structure. After photoresist removal, a thin barrier layer, followed by a second metal layer, is deposited, completely filling the recessed opened hole, and contacting the top surface, as well as the exposed sides of the first level interconnect metallization structure. The unwanted areas of the second metal layer, and the thin barrier layer, are next removed to create a metal filled contact or via, larger in width than the width of the underlying first level interconnect metallization structure.
BRIEF DESCRIPTION OF THE DRAWINGS
The object and other advantages of this invention are best described in the preferred embodiment with reference to the attached drawings that include:
FIG. 1, which schematically shows a typical N channel, (NFET), device, with a first level interconnect metallization structure.
FIGS. 2-3, which schematically show the creation of a via hole, in a planarized dielectric layer, to the underlying first level interconnect metallization structure.
FIGS. 4-5, which schematically show the stages of processing used to metal fill the via hole, and form the desired metal plug, larger in width then the width of the underlying first level interconnect metallization structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method for creating metal filled vias, larger in width then the width of an underlying interconnect metallization structure, and contacting the top surface, as well as a top portion of the sides of the underlying interconnect metallization structure, will now be covered in detail. This invention can be used as part of metal oxide semiconductor field effect transistor, (MOSFET), devices, that are now being manufactured in industry, therefore only the specific areas unique to understanding this invention will be covered in detail. FIG. 1, schematically shows a an N channel, (NFET), structure, that this invention will be applied to. A starting, P type substrate, 1, consisting of single crystalline silicon, having a <100> crystallographic orientation, is used. Thick field oxide regions, 2, (FOX), are formed for isolation purposes. The FOX regions are formed by initially creating an composite insulator oxidation mask, composed of an overlying silicon nitride layer and an underlying silicon dioxide layer. After patterning the composite insulator oxidation mask, to create the desired device region shape, followed by photoresist removal, a thermal oxidation is performed in the unmasked regions to grow between about 4000 to 6000 Angstroms of a FOX, 2, silicon dioxide region. After removal of the composite insulator oxidation mask, exposing the subsequent NFET device region, a thin gate insulator layer, 3, of silicon dioxide, is thermally grown to a thickness between about 50 to 300 Angstroms. A layer of polysilicon is next deposited using low pressure chemical vapor deposition, (LPCVD), procedures, to a thickness between about 2000 to 4000 Angstroms. The polysilicon layer is doped via an ion implantation of either phosphorous or arsenic, at an energy between about 50 to 100 Kev., at a dose between about 1E15 to 1E16 atoms/cm 2 . Standard photolithographic and reactive ion etching, (RIE), procedures, using Cl 2 as an etchant, are used to produce polysilicon gate structure, 4, shown schematically in FIG. 1.
After photoresist removal, via plasma oxygen ashing, followed by careful wet cleans, a lightly doped, N type, source and drain region, 5, is created via an ion implantation of phosphorous, at an energy between about 30 to 60 Kev., at a dose between about 1E12 to 5E13 atoms/cm 2 . A silicon oxide layer is next deposited using either LPCVD or plasma enhanced chemical vapor deposition, (PECVD), processing, to a thickness between about 1500 to 4000 Angstroms, using tetraethylorthosilicate as a source. An anisotropic, RIE procedure, using CHF 3 as an etchant, is then employed to create insulator sidewall spacer, 6. A heavily doped, N type, source and drain region, 7, is next formed, again via an ion implantation procedure, now via use of arsenic, at an energy between about 50 to 100 Kev., at a dose between about 1E14 to 5E15 atoms/cm 2 . Another silicon oxide layer, 8, is again deposited using either LPCVD or PECVD processing, at a temperature between about 400 to 800° C., to a thickness between about 3000 to 6000 Angstroms. Conventional photolithographic and RIE procedures, using CHF 3 as an etchant, are used to open contact hole, 9, to source and drain region, 7, as well as to polysilicon gate structure, 4. The opening of contact hole, 9, is between about 0.1 to 1.0 uM, in diameter. After photoresist removal, via plasma oxygen ashing and careful wet cleans, a metallization layer of aluminum, containing between about 1 to 3 weight % copper, and between about 0.5 to 1.0 weight % silicon, is deposited, using r.f. sputtering, to a thickness between about 4000 to 8000 Angstroms, completely filling contact hole, 9. An alternative is to use a metallization layer of tungsten, deposited via LPCVD procedures, at a temperature between about 400 to 600° C., again to a thickness between about 4000 to 8000, using tungsten hexafluoride as a source, and again completely filling contact hole, 9.
Patterning of the metallization layer is performed using conventional photolithographic and RIE procedures, using Cl 2 as an etchant, to produce metal structure, 10, shown schematically in FIG. 1, after photoresist removal, accomplished using plasma oxygen ashing and careful wet cleans. The width of the metal structure, 10, is between about 0.15 to 1.2 uM. The narrow metal lines are intentionally created to shrink the metal line--space periodicity, which is easier to accomplish then decreasing the subsequent, overlying metal filled via--space periodicity.
A deposition of a silicon oxide layer, 11, is next performed, using PECVD processing, at a temperature between about 400 to 600° C., to a thickness between 3000 to 10000 Angstroms. A chemical mechanical polishing procedure is then used to planarize silicon oxide layer, 11, for purposes of optimizing subsequent via hole formation, in silicon oxide layer, 11. Photoresist layer, 12, is then applied and exposed to open regions, 13, in photoresist layer, 12, shown schematically in FIG. 2. Opening, 13, is formed, directly overlying metal structure, 10, to a width between about 0.2 to 1.3 uM, intentionally larger then the width of underlying metal structure, 10. A RIE procedure, using CHF 3 is then performed, using opening, 13, in photoresist layer, 12, to create opening, 14, in silicon oxide layer, 11. The RIE procedure is performed to initially remove all of insulator layer, 11, from the top surface of metal structure, 10. Then the dry etching process is continued to remove between about 1000 to 5000 Angstroms of additional silicon oxide layer, 11, recessing opening 14, below the top surface of metal structure, 10, and thus exposing a portion of the sides of metal structure, 10. This is schematically shown in FIG. 3. Photoresist removal is again accomplished using plasma oxygen ashing and careful wet cleans.
A layer of titanium nitride, 15, with an optional underlying layer of titanium, not shown, is illustrated schematically in FIG. 4. The titanium nitride layer, 15, is deposited using r.f. sputtering, or via use of chemical vapor deposition processes, to a thickness between about 50 to 1000 Angstroms, and is used for barrier, as well as for electromigration resistance enhancements. Another metallization layer of aluminum, containing between about 1 to 3% copper, and between about 0.5 to 1.0% silicon, is deposited, using r.f. sputtering, to a thickness between about 4000 to 8000 Angstroms, completely filling opening, 14. Again an alternative is to use a metallization layer of tungsten, deposited via LPCVD processes, at a temperature between about 300 to 600° C., to a thickness between about 4000 to 8000 Angstroms. The removal of unwanted metal, aluminum or tungsten, as well as titanium nitride, is accomplished via either a selective, RIE procedure, using Cl 2 as an etchant, or via use of a chemical mechanical polishing procedure, selectively stopping at the top surface of silicon oxide layer, 11. This procedure results in the formation of metal plug, 16, filling opening, 14, and contacting the top surface, as well as a portion of the exposed sides of underlying metal structure, 10. This is described schematically in FIG. 5. The creation of a metal filled via, or metal plug, larger in width then the underlying metal structure, reduces the stringent photolithographic alignment requirements, experienced when using small vias, on larger underlying metal structures. In addition this process allows the insulator layer, surrounding the underlying metal structure, to be recessed, exposing additional contact surfaces, thus reducing contact or interface resistances, and enhancing performance.
This process, although shown as an application to NFET device structures, can benefit applications for P channel, (PFET), device structures, complimentary, (CMOS), device structures, as well as benefitting BiCMOS designs.
While this invention has been particularly shown and described with reference to, the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of this invention.
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A process has been developed in which the contact area, between an overlying metal filled via structure, and an underlying metal interconnect structure, has been increased. The process features opening a via hole, in a dielectric layer, to an underlying metal interconnect structure, with the via hole being larger in width then the width of the underlying metal interconnect structure. Continued selective removal of the dielectric layer, in the via hole, results in exposure of the sides of the metal interconnect structure. Subsequent formation of an overlying metal filled via structure, in the via hole, results in an increase in contact area between the overlying metal filled via structure, and the narrow, metal interconnect structure.
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BACKGROUND OF THE INVENTION
The present invention relates to a ball mainly used for games of children.
As balls for sports and games of children such as soccer balls are conventionally used balls of hard rubber inflated with air as in the case of balls for adults. Balls of hard rubber of this type bring about a lot of fun since they have good elasticity and bound well. On the other hand, since they are relatively hard and heavy, they may hurt the faces or heads of children. Furthermore, with an inflated ball of hard rubber, the internal pressure of the ball is reduced due to leakage of air. Then, a puncture is caused and the ball loses its bounce, requiring care such as refilling of air. Therefore, balls of this type are not suitable for children from this respect as well.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a ball which is excellent in safety, which has suitable elasticity, and which does not lose elasticity as a result of loss of air which causes a puncture.
It is another object of the present invention to provide a ball which has water-resistance in addition to the properties as described above.
It is still another object of the present invention to provide a ball which has a thin surface film or layer which is strongly adhered to an inner soft foam.
According to an aspect of the present invention, there is provided a ball comprising a spherical soft foam, and a surface layer of polyvinyl chloride formed on the surface of the foam. This ball may be manufactured by forming the surface layer of the ball by rotational casting, injecting a foamable composition within the cavity defined by the surface layer, and foaming the composition to form the soft foam.
Alternatively, the ball may be manufactured by coating the surface of a spherical soft foam with a polyvinyl chloride resin paste, charging the foamed body into a ball forming mold, and curing the resin paste.
Still alternatively, the ball may be manufactured by coating the inner surface of a ball forming mold with a polyvinyl resin paste, charging a spherical foam into the mold, and curing the resin paste. According to the present invention, the soft foam preferably consists of polyurethane or rubber.
According to another aspect of the present invention, there is also provided a ball comprising a spherical body of foamed vinyl chloride having a spherical cavity at the center thereof. This ball is manufactured by rotational casting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cutaway perspective view of a ball according to an embodiment of the present invention;
FIG. 2 is a partial, enlarged, sectional view of the ball shown in FIG. 1;
FIG. 3 is a sectional view of a ball according to another embodiment of the present invention;
FIG. 4 is a sectional view according to still another embodiment of the present invention;
FIG. 5 is a sectional view of a ball according to still another embodiment of the present invention; and
FIG. 6 is a plan view of a semispherical body of polyurethane foam formed in a step according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described by way of its examples.
EXAMPLE 1
FIG. 1 is a partially cutaway perspective view of a game ball according to the present invention. A surface layer 1 of 2 to 10 mm thickness is formed by rotational casting of foamed polyvinyl chloride having a specific gravity of 0.2 to 0.5. A soft polyurethane foam of cold-cure type is injected into the cavity defined by the surface layer 1, forming a spherical body. The compositions of the soft polyvinyl chloride of the surface layer 1 and the soft urethane foam 2, and methods for manufacturing the same were as follows:
______________________________________Vinyl Chloride Resin Paste 100 parts by weightDioctyl Phthalate 120 parts by weightAzodicarbonamide 2.5 parts by weightStabilizer (zinc stearate) 2.0 parts by weightFoam Stabilizer 1.0 part by weightPigment 3.0 parts by weight______________________________________
The raw materials as represented above were kneaded into a paste. The composition obtained was charged into a ball forming mold in the amount of 140 g. The surface layer of 3 mm thickness was obtained by rotational casting.
______________________________________Trifunctional polyether 95 parts by weightpolyol having 3,000 MWQuadrifunctional polyether 5.0 parts by weightpolyol having 750 MWDiethanolamine 1.0 part by weightTriethylenediamine 0.2 part by weightDibutyltindilaurate 0.2 part by weightSilicone Oil 1.5 parts by weightH.sub.2 O 4.0 parts by weightTolylenediisocyanate (80/20) 48.0 parts by weight______________________________________
The raw materials as presented above were mixed together and the resultant composition was injected into the cavity formed by the surface layer described above.
With a ball of the structure as described above, since the spherical shape is maintained by the soft urethane foam charged inside the surface layer 1, a puncture may not be caused by leakage of air as in the case of a conventional ball. Therefore, the ball of the example does not require much care and may withstand semipermanent use. Since the surface layer 1 is also made of soft vinyl chloride, it has proper flexibility and absorbs impact upon collision with faces or heads of children. Spraining or hurting of fingers may be prevented. Thus, the ball of this example has properties preferable as a ball for children. The ball of the example also has suitable elasticity as will be shown below and may not impair the fun of a game.
Elasticity Test Results
Diameter of Ball: 18 cm
Drop Height: 1 m above the ground (free drop)
Bounce: 0.45 m
In a ball manufactured in this manner, the surface layer 1 of foamed polyvinyl chloride has closed cells, while the soft polyurethane foam 2 has open cells.
FIG. 2 is a partial, enlarged, sectional view of the ball shown in FIG. 1. Reference numeral 3 denotes a through hole having a diameter of 3 to 7 mm which is formed after the raw material is injected therethrough for rotational casting. A nonfoamed soft resin 4 such as polyurethane elastomer closes the through hole 3.
Since the surface layer 1 has closed cells, it is high in water resistance and hardly absorbs water. On the other hand, since the soft polyurethane foam 2 has open cells, it is low in water resistance and easily absorbs water. Therefore, if the through hole 3 formed in the surface layer is left unclosed, water may permeate into the soft polyurethane foam 2 through the through hole 3 when the ball lands in a pond or puddle. Then, the ball becomes heavier and has a lower elasticity.
However, by closing the through hole 3 with the nonfoamed soft resin 4 which is excellent in water resistance, permeation of water may be prevented.
EXAMPLE 2
A ball of this example has a water-resistant film 5 interposed between the surface layer 1 and the soft polyurethane foam 2, as shown in FIG. 3. Referring to FIG. 3, the surface layer has a thickness of 2 to 10 mm and is formed by rotational casting of foamed polyvinyl chloride having a specific gravity of 0.2 to 0.5. The water-resistant film 5 coated by spray coating is formed on the inner surface of the surface layer 1. The soft polyurethane foam 2 of cold-cure type is injected inside the water-resistance film 5, providing a spherical body.
The ball of the example may be manufactured in the following manner.
The raw materials for the foamed PVC as in Example 1 were kneaded into a paste. The paste was charged in the amount of 140 g into a ball forming mold. The surface layer 1 of 3 mm thickness was formed by rotational casting.
A resin solution of the following composition was spray-coated on the inner surface of the surface layer 1 to form the water-resistant film 5:
______________________________________Acrylic Resin Latex 100 parts by weightCarboxymethyl Cellulose 0.5 part by weightMelamine Resin 1.0 part by weight______________________________________
After mixing the soft polyurethane foam raw materials of the composition same as that in Example 1, the resultant composition was injected into the cavity defined by the surface layer 1 in the amount of 120 g. Foaming was performed to provide a water-resistant and no-puncture ball having a diameter of 18 cm.
The ball of the structure as described above is safe to play with and a puncture is not formed. Moreover, since the water-resistant film 5 is formed on the inner surface of the surface layer 1, the permeation of the water introduced through the surface layer 1 into the soft polyurethane foam 2 may be prevented.
Examples of the resin solution for forming the water-resistant film include natural rubber latex, synthetic rubber latex, polyamide resin or the like in place of the resin solution containing the acrylic resin as a main component.
EXAMPLE 3
A ball of this example is shown in FIG. 4.
Referring to FIG. 4, reference numeral 6 denotes a spherical body consisting of foamed polyvinyl chloride. A substantially spherical cavity 7 is formed at the center of the spherical body 6. The spherical body 6 of foamed polyvinyl chloride may be manufactured in the following manner:
______________________________________Raw Material Composition:______________________________________Vinyl Chloride Resin Paste 100 parts by weightDioctyl Phthalate 120 parts by weightAzodicarbonamide 2.5 parts by weightStabilizer (zinc stearate) 2.0 parts by weightFoam Stabilizer 1.0 parts by weightPigment 3.0 parts by weight______________________________________
These raw materials were kneaded into a paste. The paste was charged into a ball forming mold in the amount of 120 g. Rotational casting was performed to provide spherical body 6 having a diameter of 7 cm. A substantially spherical cavity 7 having a diameter of 2.3 cm was formed at the center of the spherical body 6.
With a ball of this structure, the spherical shape of the ball is maintained not by the air pressure filled inside the cavity at the center but by the rigidity and elasticity of the spherical body 6 of foamed polyvinyl chloride. Therefore, a puncture may not be caused by leakage of air as in the case of a conventional ball. The ball of the example can thus withstand semipermanent use without requiring much care. Since the ball is made of foamed vinyl chloride, it has suitable flexibility. The flexibility of the ball is further enhanced by the cavity 7 formed at the center. Therefore, the impact is absorbed and spraining of a finger is not caused when the ball is caught, or injury is not caused when the ball collides with a face or head of a child. Thus, the ball of the example has suitable properties for handling by children. Furthermore, since the ball of the example has suitable elasticity as seen from the test results presented below, it may not impair the fun of games of children.
Elasticity Test Results
Drop Height: 1 m above the ground (free drop)
Bounce: 0.4 m
EXAMPLE 4
A ball of the example is shown in FIG. 5. Referring to FIG. 5, the spherical body 6 consists of foamed polyvinyl chloride. The substantially spherical cavity 7 is formed at the center of the spherical body 6. A water-resistant film 8 containing an acrylic resin as a main component is formed on the surface of the cavity 7 by spray coating.
The ball of this example may be manufactured in the following manner.
The raw material for the foamed PVC as in Example 3 were kneaded into a paste. The paste was charged into a ball forming mold in the amount of 120 g. Rotational casting was performed to provide a spherical body having a diameter of 7 cm. A substantially spherical cavity 7 having a diameter of 2.3 cm was formed at the center of the spherical body 6.
A through hole was formed from the surface of the spherical body 6 to the cavity 7. A resin solution having the composition represented below was coated by spray coating on the surface of the cavity 7 through this through hole to form a water-resistant film 8.
______________________________________Acrylic Resin Latex 100 parts by weightCarboxymethyl Cellulose 0.5 part by weightMelamine Resin 1.0 part by weight______________________________________
The through hole formed for the purpose of spray coating was closed to provide the ball of this example.
The ball of the structure as a described above is safe and is free from a puncture as in the case of Example 3. Moreover, the permeation of water introduced from outside into the cavity 7 is prevented by the water-resistant film 8. Therefore, even if the ball lands in a pond or the like and absorbs water, it can be completely dried within a shorter period of time than with the ball of Example 3. Since the water-resistant film 8 is formed not on the surface of the spherical body but on the surface of the cavity 7, the feeling and appearance of the ball may not be impaired irrespective of the type of material used for the water-resistant film 8.
EXAMPLE 5
A semispherical body having a diameter of 20 cm was cut out by three-dimensional cutting from a polyurethane foam block having a specific gravity of 0.027. Part of the inner portion of the semispherical body was further cut out by three-dimensional cutting to provide a semispherical polyurethane foam 10 having a semispherical outer shape and a semispherical cavity 9 inside, as shown in FIG. 6. Two such semispherical polyurethane foams 10 were adhered together to form a spherical polyurethane foam having a spherical outer shape and a cavity inside. Subsequently, a polyvinyl chloride resin paste having the composition represented below was coated to a thickness of 1 mm by spray coating:
______________________________________Vinyl Chloride Resin Paste 100 parts by weightDioctyl Phthalate 120 parts by weightAzodicarbonamide 2.5 parts by weightStabilizer (zinc stearate) 2.0 parts by weightFoam Stabilizer 1.0 part by weightPigment 3.0 parts by weight______________________________________
These raw materials were charged into an electroforming mold having a diameter of 20 cm. After heating at 280° C. for 15 minutes by rotational casting, the composition was cooled and was released from the mold. A ball having a surface layer of polyvinyl chloride and of 0.5 mm thickness formed on the surface of a polyurethane foam was obtained.
The peeling test of the surface layer and the polyurethane foam of the ball of this example was performed. No peeling was observed; the polyurethane foam was broken instead.
Although the cavity was formed in this example, it need not be formed. The soft foam having the spherical shape can be alternatively formed by charging a soft foamable raw material into a ball forming mold and foaming the raw material. However, it is preferable to cut out the spherical body by, for example, three-dimensional cutting from a soft foam of block shape as in Example 5.
The polyvinyl chloride resin paste to be coated on the surface of the soft foam having the spherical outer shape obtained in this manner is used to form the surface layer of the ball. Although the paste generally contains a foaming agent, it need not contain a foaming agent if the surface layer is to be formed very thin. If the surface layer must be formed to a relatively great thickness, a resin paste having a high viscosity is used. The resin paste may be coated with a brush or by other suitable means. However, when the paste is coated by spray coating, the surface layer may be coated to a uniform thickness and can be formed to a very small thickness.
After the paste is coated, the foam is charged into a ball forming mold. Although an electroforming mold used in FIG. 5 is preferable, other molds such as aluminum molds, metal sheet molds or the like may also be used. The size of the cavity of the mold is preferably equal to or slightly smaller than the size of the ball to be manufactured. A ball consisting of a soft foam with the integral surface layer is obtained by curing the resin paste coated on the soft foam inside the cavity of mold. If the polyvinyl chloride resin containing a foaming agent is used, the surface layer of polyvinyl chloride foam is formed by foaming simultaneously with curing.
In Example 5, after the soft foam having a spherical outer shape is prepared, a polyvinyl chloride resin paste for forming the surface layer is coated on the surface of the soft foam. Therefore, the surface layer of the soft foam is partially impregnated with the resin paste. Therefore, a strong adhesion is obtained between the surface layer and the soft foam with a ball obtained by curing, so that the soft foam and the surface layer may not separate over a long period of time. In this case, if the cells are exposed to the surface of the soft foam to be coated with the resin paste, the soft foam can be easily impregnated with the resin, resulting in a strong adhesion. For this reason, when the soft foam is cut out from the block, it is preferable to cut out a spherical body in such a manner as to expose the cells to the surface thereof. When the ball is manufactured by molding, a thin skin layer is formed on the molded spherical body, so that the effects of impregnation with the resin paste become relatively small.
Since the polyvinyl chloride resin paste can be coated to a very small thickness in Example 5, a no-puncture ball having a very thin surface layer can be obtained. In this case, the feeling of the soft foam is transmitted to the hands through the surface layer. If the surface layer is a thin layer, the surface layer need not be a foamed layer. Therefore, even if the surface layer is made of nonfoamed polyvinyl chloride resin, a no-puncture ball which is sufficiently soft and safe can be obtained.
EXAMPLE 6
A semispherical body having a diameter of 20 cm was cut out by three-dimensional cutting from a polyurethane foam block having a specific gravity of 0.027. A semispherical polyurethane foam 10 having a semispherical cavity 9 was obtained by cutting out part of the inner portion of the semispherical body by three-dimensional cutting, as shown in FIG. 6. Two such semispherical polyurethane foams 10 were adhered by an adhesive to provide a polyurethane foam having a spherical outer shape and a cavity inside. A polyvinyl resin paste of the composition same as that used in Example 5 was coated to a thickness of 2 mm by spray coating on the surface of a cavity of an electroforming, ball-forming mold having a diameter of 20 cm.
Subsequently, the polyurethane foam was charged into this electroforming mold. Rotational casting was performed at 280° C. for 15 minutes. The ball was cooled and was released from the mold. Thus, a ball having a polyurethane foam and a surface layer of polyvinyl chloride having a thickness of 1 mm and formed integrally with the foam was obtained.
The ball exhibited excellent characteristics as the ball in Example 5.
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The invention provides a ball for a game having a spherical soft polyurethane foam and a surface layer of foamed polyvinyl chloride formed on the surface of the spherical body. The ball is produced by first casting the surface layer in a mold to form a hollow foamed PVC body having closed cells, and then charging a foamed polyurethane composition into the hollow thus formed, to produce a sphere of polyurethane having open cells within the surface layer. Also provided is a ball for games having a spherical body of foamed polyvinyl chloride and having a spherical cavity at the center. The ball is safe, has proper flexibility, and is not subject to punctures.
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This is a continuation-in-part of United States patent application Ser. No. 304,425, filed on Nov. 6, 1972, and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to chemical processes, and more particularly, to an efficient and inexpensive method for recovering uranium from process effluents, and the like.
2. Description of the Prior Art
In order to produce fuel for nuclear reactors, it is often necessary to convert uranium hexafluoride into uranium dioxide. A number of techniques have been developed for this purpose. It has been suggested, for example, to mix an aqueous solution of uranium hexafluoride with ammonia and carbon dioxide in the AUC process. In addition to a uranium precipitate, this process also produces a filtrate and an absorption washer waste that contain NH 4 F (ammonium fluoride), ammonia and carbon dioxide as well as trace amounts of uranium. The carbon dioxide is removed from the filtrate through an expeller and thermosiphon evaporator loop, an expensive and complicated item of process equipment.
In subsequent stages, moreover, colloidal suspensions, or gels, are formed that liquify when stirred and solidify on standing. This characteristic, known as thixotropy, renders the fluoride precipitation and recovery stage inefficient, time-consuming and expensive.
There are further considerations that transcend the conventional chemical process economics. For instance, not only must the process wastes be environmentally acceptable but the uranium accumulated within the process stages also must at no time reach a "critical" mass sufficient to initiate an accidental nuclear fission reaction. In this latter regard, it has been noted that higher than usual concentrations of uranium in the filtrate that provides the feed for this process tends to cause an (NH 4 ) 3 UF 8 precipitate in the first stage expeller.
It is possible that this precipitate might settle into a critical assembly that would produce a dangerous nuclear reaction.
Accordingly, there is a need for a safe, less expensive and more efficient uranium dioxide conversion waste treatment process than that which heretofore has been available.
SUMMARY
In accordance with the invention, these foregoing problems associated with the treatment of the aqueous effluents that are produced in converting uranium hexafluoride into uranium dioxide are, to a large extent, overcome. A typical example of the invention commences with an effluent, filtrate or process liquid and absorption washer waste from the AUC process in which the filtrate has a titratable basicity of 2.0 to 2.5 equivalents per liter (eq/1) and an hydronium concentration that corresponds to a pH of about 9.0 to 9.5. In passing it should be noted that the pH system is a quantitative measure of solution alkalinity. Neutral solutions, for example, have a pH of 7; acidic solutions have pH values that are less than 7; and pH of alkaline solutions is greater than 7.
A typical liquid effluent providing a suitable feed or process liquid for the practice of the present invention might contain large amounts of ammonium, carbonate and fluoride as well as a relatively small amount or uranium. This liquid is poured into an acidification vessel in which it is mixed with enough H 2 SO 4 (sulfuric acid) to reduce the pH to 7 or less. The reactant liquid is stirred and cooled to release CO 2 gas, thereby reducing the carbonate concentration to an acceptable level. This reduction in carbonate concentration promotes a more complete uranium separation in the second stage of the process because, it has been found, "high" carbonate concentrations seem to hinder uranium precipitation.
The process liquid then is tranferred to a uranium precipitation tank, and an aqueous ammonia solution or gaseous ammonia is added to the liquid in order to increase the pH to a range of 8.5 to 9. After establishing a suitably basic solution, H 2 O 2 (hydrogen perioxide) is added to the uranium precipitation tank for the purpose of uranium separation. In accordance with a feature of the invention, the sulfates carried over from the sulfuric acid treatment remain in solution in the uranium precipitation tank.
The uranium is almost completely separated in this stage, the separation factor being greater than 0.99. It has been found, moreover, that the uranium precipitates as a new inorganic chemical compound, UO 4 .2NH 3 .2HF [uranyl peroxide -2-ammonia-2-(hydrogen fluoride)].
After the uranium precipitation is complete, the sulfate-bearing process liquid filtrate is transferred to a fluoride precipitator and filter tank in order to recover this element. To separate the fluorides, calcium oxide is added to the filtrate and the pH of the resulting liquid increases to about 12. The precipitate settling out of this third stage contains CaF 2 (calcium fluoride), CaSO 4 (calcium sulfate), and CaO.xH 2 O (hydrated calcium oxide). It appears that the sulfate, added in the first stage as a part of the reagent used to drive off the carbon dioxide, provides the unusual and unexpected benefit in the third stage of promoting better filtration by preventing the formation of the thixotropic colloid that has balked prior fluoride filtration techniques.
In this third stage, water vapor and ammonia also are evaporated and passed through a condenser to produce aqueous ammonia, a portion of which may be recycled back into the second stage for pH adjustment. The balance of the aqueous ammonia can, moreover, be made available for other uses. For example, this extra aqueous ammonia can be "rectified" or separated into water and dry ammonia gas. The dry ammonia gas then can be applied to the AUC process from whence the effluents under consideration were derived. Some of the dry ammonia gas also can be applied to pH adjustment in the second stage, if this stage is designed to accept gaseous ammonia.
The liquid that is discharged from this process can be disposed of through ordinary sewage facitities because the industrial and environmental contaminants in this waste are within the present or anticipated acceptable maxima for these materials.
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 specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic process flow diagram illustrating the principles of the invention;
FIG. 2 illustrates (at 10,000 magnifications with a scanning electron microscope) the clearly defined and highly ordered crystalline structure that characterizes the new uranium compound produced in the process that is shown in FIG. 1;
FIG. 3 is the X-ray powder diffraction pattern of the new uranium compound shown in FIG. 2 in comparison with the X-ray powder diffraction pattern of a hitherto known uranium compound; and
FIG. 4 illustrates the monoclinic crystal structure that characterizes the new compound that is shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For a more complete appreciation of the invention, attention is invited to the following description of an illustrative embodiment of the invention. To store and prepare raw materials for the process, two tanks, a filtrate storage tank 10 and fluid bed absorption washer waste tank 11 are provided. The washer waste tank, moreover, is equipped with a stirrer 12 and inlet piping 13 and 14 in order to add NH 4 HCO 3 , and aqueous NH 3 , respectively, to the waste. To inlets 13 and 14 and the reagents added to the washer waste through these inlets are for process study purposes. The temperature of the mixer, moreover, is maintained through a steam jacket 15, also provided for study purposes.
Typical average chemical compositions along with other chemical and physical data for these effluents are tabulated as follows:
______________________________________ F. B. Absorp. AUC Filtrate Washer Waste 1:1 Mixture______________________________________NH.sub.4 .sup.+ 146 g/l *60 g/l 103 g/lTot. carbonatespecies as CO.sub.3 .sup.= 74 g/l *153 g/l 114 g/lF.sup.- 100 g/l nonappreciable 50 g/lU (tot.) 267 mg/l **70 mg/l 168 mg/lFe (tot.) **66 mg/lCr (tot.) **1 mg/lNi (tot.) **0.9 mg/lpH 9.0-9.5 8.8-9.0 9.0Titrable 2.0-2.5N 2.0-2.5N 2.0-2.5NbaseDensity(at 18°C) 1.10 g/cc 1.06 g/ccSpecific 0.92 0.94heat Cal/g-°C Cal/g-°C______________________________________ *Calculated from mass balance **Observed
The AUC filtrate and the washer waste are drawn from the tanks 10 and 11 through conduits 16 and 17, respectively. The two fluids are combined in equal proportion, in one or more mixing tanks 20 to form a mixture, or liquid that is passed through a conduit 21 to an acidification vessel 22. Naturally, the process can be applied to either the AUC filtrate or to the washer waste alone.
Illustratively, the vessel 22 is equipped with a stirrer 23, a CO 2 gas discharge 24, an H 2 SO 4 inlet 25, a pH meter 26 and an immersed cooling water coil 27.
H 2 SO 4 is added to the stirred and cooled mixture in the vessel through an L-shaped tube (not shown) until the pH is less than 7 and preferably, about 6.5. Other strong acids, hydrochloric, nitric, and hydrofluoric acids, for example, are suitable for carbonate separation. Weaker acids, e.g. acetic acid, are likely to be relatively inefficient and uneconomical for this purpose.
The L shaped tube is used for acid addition because it enables the CO 2 that is released through the contact between sulfuric acid and the AUC - waste mixture to flow through the liquid before being discharged into the atmosphere. This feature of the invention minimizes the liberation of other volatile materials that usually occurs because of the local heat that is generated through the liquid-acid contact.
Preferably, the cooling coil 27 maintains the solution temperature below 40°C in the first stage of the process. In an illustrative embodiment of the invention, about 200 liters (1) of only AUC filtrate having a composition of the sort decribed in the above table, are transferred from the AUC filtrate storage tank 10 to acidification vessel 22. Depending on the CO 3 - - concentration, 10 to 20 l of the concentrated H 2 SO 4 is added to the vessel 22 in order to lower the pH to 6.5. Although the 6.5 pH is a preferred value, any acidic pH less than 7 should be acceptable, the acid being added until the desired amount of carbonate is driven off. The liquid in the vessel 22 is vigorously stirred during acid addition and is cooled to less than 40°C, if necessary, in order to eliminate the inclusion of other volatile materials in the CO 2 gas that is being released through the discharge 24.
When the final CO 3 - - concentration in the resulting liquid is reduced to less than 5 g/l, the filtrate is transferred into a uranium precipitator and filter 30 through a conduit 31. The uranium precipitator 30 is equipped with H 2 O 2 and gaseous NH 3 inlets 32 and 33, respectively, Aqueous ammonia, however, could be used in this instance if desired.
In operation, and in accordance with a further feature of the invention, the liquid mixture or residual mixture has a concentration of SO 4 - - (sulfate) ions in solution as a consequence of H 2 SO 4 addition in the preceding acidification stage. As described subsequently in more complete detail, the sulfate ion appears to inhibit thixotropy and promote filtration in the third stage. Thus, the addition of H 2 SO 4 in the first state not only eliminates the need for a great deal of elaborate thermosiphon evaporator and related apparatus in that stage, but also provides a more subtle and unexpected benefit in the last stage of the process.
The residual mixture that is transferred to the precipitator and filter tank 30 is heated to 45° to 50°C. On reaching this temperature range, the heating is discontinued. The residual mixture than is made basic by adding NH 3 through the inlet 33 in either an aqueous solution or as a gas. Although NH 3 is described for the purpose of illustration, any base should serve the purpose of the invention as long as the cation from the base is acceptable in the process waste and produces the uranium precipitate that is hereinafter described in more complete detail. Ammonia, moreover, is particularly suitable for the purpose of the invention because ammonium ions are in the feed mixture at the start of the process.
The pH of the residual mixture should be adjusted to a range of 8.5 to 9. In this connection, a pH of 9 has been found most suitable for the process. After the foregoing heating and pH adjustment, the H 2 O 2 is added to the solution by way of the inlet 32. About 2 ml of 60 percent H 2 O 2 is required for each liter of the residual mixture in the tank 30 in order to provide an adequate excess for optimum uranium precipitation.
The uranium precipitator 30, moreover, also has a pair of filters candles with a total filter surface of 350 cm 2 and a porosity of 0.4 μ with a 98percent nominal hold-back to provide extraction means 34 to separate the uranium precipitate from the residual mixture. To promote mixing and settling, the precipitator and filter tank 30 also has a stirrer and an internal steam coil, none of which is shown in the figure of the drawing. Extracting the filtrate from the precipitator and filter tank 30 is promoted by maintaining a vacuum on the filter candles 34 through a vacuum pump (not shown in the figure drawing). The reaction mixture is stirred and a precipitate forms slowly. Typically, the stirring is continued for approximately one hour followed by one hour for settling. At the end of the second hour, the precipitation is almost complete and has been shown to have a value in excess of 99percent uranium precipitation.
As shown in the drawings, the uranium precipitate is removed from the precipitator and filter tank 30 through a separation means 35 after about seven or eight batches have been processed in the precipitator and filter 30. Preferably, the separation means 35 comprises a plain suction filter assembly having a PALL Grade H stainless steel sintered filter plate. It has been found that some of the uranium precipitate should remain in the precipitator and filter after most of this material has been removed by way of the separation means in order to provide seeding for the next precipitation. This seeding improves the settling and filterability of subsequent residual mixture batches. It is believed that this occurs because the uranium in the supernatant (the liquid above settled precipitate) is reduced significantly through filtering in the precipitate layer that formed on the filter candles 34. It has been further theorized that this phenomenon occurs because very fine particles suspended in the supernatant are retained in the precipitate layer, and, or perhaps alternatively, the uranium which has not been precipitated also is sorbed in this layer.
The filtrate that is drawn through the filter candles 34 flows into a F - or CaF 2 -CaSO 4 -CaO.xH 2 O precipitation and filter tank 36 as shown in the drawing. The tank 36 has an inlet 37 through which solid CaO is added to the reaction liquid. A vapor discharge 40 also is provided through which NH 3 vapor and water vapor are withdrawn from the tank 36. Process efficiency, moreover, is increased through NH 3 recovery and recycling. A precipitate discharge 41 also is associated with the tank in order to enable the F - , SO 4 - - , and hydrate compounds to be withdrawn. Barium oxide, magnesium oxide and calcium hydroxide also might be suitable for the purpose of precipitating the F - and SO 4 - - and liberating the NH 3 , although these reagents would be less attractive than the illustrative CaO.
A further filtrate discharge 42 is provided in order to withdraw the depleted process liquid, which, in accordance with a feature of the invention, has concentrations of chemical matter that are so low that they could be discharged into conventional waste disposal systems.
In operation, a vacuum of about 40-100 mm of water (gauge) is maintained in the tank 36 in order to accelerate NH 3 and water vapor discharge. Conventional chemical process equipment also associated with the CaF 2 precipitator and filter tank 36 includes an air inlet or sparge, a stirrer, a steam jacket, and an internal water cooling coil (not shown in the drawing).
Preferably, the filtrate in the CaF 2 precipitator and filter tank 36 is heated to 80° to 85°C. On reaching this temperature range, heating is discontinued and solid CaO is added to the liquid. The reaction between the liquid and CaO is exothermic, i.e., the reaction generates heat.
Consequently, the CaO is added to the liquid very slowly through the use, for example, of a feed screw. The CaO is added until, in the preferred embodiment, a 20 percent excess of CaO over the calculated amount that is necessary to precipitate all of the F - and SO 4 - - is reached. Thus, for example, for a 200 l filtrate batch, approximately 50 kg of CaO is added over a period of 11/2 hours.
The resulting reaction mixture is stirred continuously as the gaseous NH 3 and water vapor are liberated. These gases, are passed through a stainless steel plate and frame type heat exchanger or condenser 43 in order to condense the gaseous NH 3 and water vapor and produce an aqueous NH 3 .
As shown in the drawing, the condenser 43 is provided for the purpose of NH 3 recovery. A portion of the aqueous NH 3 is withdrawn from the condenser 43 by way of the NH 3 inlet 33 and is recycled into the uranium precipitator 30 for pH adjustment in that second stage, as hereinbefore described.
As previously mentioned, an important although subtle advantage of the invention is the relatively trouble free and efficient filtration of solid matter from the reaction liquid in the CaF 2 precipitator tank 36 because of the SO 4 - - carried through to this third and last stage of the process seems to inhibit gel development within the tank. Thus, it appears that gel formation which tends to frustrate precipitation of solid matter in prior filtrates does not develop because of the presence of the sulfate ion that was carried over from the initial addition of H 2 SO 4 to the first stage of the process.
The pH of the liquid in the tank 36 is not particularly important but generally reaches a value of about 12. After the CaO addition is complete, the filtrate is boiled to expell more gaseous NH 3 and leave a residual slurry in the CaF 2 precipitation tank 36. This slurry is not thixothropic and contains, in solid form, a mixture of CaF 2 , CaSO 4 , and CaO.xH 2 O. The filtering of this solid matter from slurry is relatively easy and, in the illustrative embodiment of the invention, produces 100 kg of precipitate cake in each hour.
Preferably, the CaF 2 precipitator and filter tank 36 comprises a Dorr-Oliver vacuum drum filter that is equipped with roller discharging and is connected to a vacuum pump and tank assembly.
Process waste liquid that is discharged through the conduit 42 contains an insignificant concentration of industrial waste products and contaminants. For example, the NH 4 + is in an amount of less than 100 mg/l; the CO 3 - - occurs in an amount that corresponds to normally dissolved CO 2 ; F - concentration is less than 10 mg/l; and U is less than 1 mg/l.
Turning once more to FIG. 1 it has been found that the uranium precipitate that forms on the separation means 35 is a bright yellow precipitate that has a novel chemical composition identified as UO 4 .2NH 3 .2HF [uranyl peroxide-2-ammonia-2-(hydrogen fluoride)]. FIG. 2 of the drawing illustrates (at a magnification of 10,000 with a scanning electron microscope) the clearly defined highly ordered crystalline structure that characterizes this compound. This substance has an X-ray powder diffraction pattern exhibiting some similarities to that which has been reported for UO 4 .4H 2 O. A comparison between the two diffraction patterns that are unique to and identify the compounds under consideration is shown in FIG. 3. Two salient differences between these patterns are apparent from a study of this figure. As viewed in FIG. 3 the UO 4 .2NH 3 .2 HF line pattern appears to have been shifted slightly to the right of the UO 4 .4H 2 O pattern. The intensity of the UO 4 .2NH 3 .2HF lines is much greater than the UO 4 .4H 2 O lines. This greater intensity demonstrates the better crystallinity and relatively larger crystallite size of the UO 4 .2NH 3 .2HF compound.
Chemical analyses, moreover, further support this proof of a new inorganic compound because these analyses indicate that the precipitate in the filter 30 contains almost no water but contains, instead, apparently equimolecular amounts of ammonium and fluoride.
EXAMPLE
Preparation
The sample used for identification was drawn from 200 l of an AUC waste solution containing 0.0021 M (molar) uranyl ion, 9.32 M ammonium, 9.10 M fluoride, 0.02 M total carbonate, and having a pH of 9.0. The total amount of other impurities was less than 50 mg/l.
The precipitation was carried out at 50°C by adding 600 ml of 40 percent hydrogen peroxide solution, corresponding to an approximately 20 fold excess relative to uranyl ion. The deeply orange-red mixture was stirred vigorously till the first turbidity appeared and then allowed to stand for a few hours. The bulk of the filtrate, which contained 0.5 mg/l uranium, was decanted; the remaining suspension being filtered, preferably over a steel filter plate, in the separation means 35. (FIG. 1) The precipitate was washed with distilled water until free of ammonium and fluoride and vacuum dried at room temperature.
Chemical Analyses -- For uranium, ammonia, fluoride, peroxidic oxygen, iron, water and total carbonate
The amount of uranium in the sample was determined through a volumetric method. A sample of the dried solid precipitate was dissolved in dilute sulfuric acid and was freed of cationic impurities by extraction of the latter with cupferron/chloroform. This extraction technique is described in TID-7029 (National Technical Information Service, U.S. Department of Commerce, Springfield, Va. 22151.) The uranium was reduced to the tetravalent state in a Jones reductor and subsequently oxidized with ferric iron. The ferrous iron so formed was titrated with 0.025 N potassium dichromate with sodium diphenylaminesulfate as an indicator.
Fluoride was determined in an acidic solution of the precipitate sample in the following fashion. The solution was buffered with chloroacetic acid and sodium hydroxide at pH 2.6 and directly titrated with 0.1 N thorium nitrate solution. Alizarin S was used as an indicator.
Ammonia in the precipitate sample was determined through the conventional Kjeldahl method. This method is described, for example, on pages 311 through 313 of ANALYTICAL CHEMISTRY--AN INTRODUCTION by D. A. Skoog et al., Holt, Rinchart and Winston, N.Y., 1965.
Peroxidic oxygen was determined in the precipitate by means of titration with 0.1 N potassium permanganate solution, in the manner that is more completely described in the paper published by G. W. Watt, S. O. Achorn and J. L. Marley. (J. Am. Chem. Soc. 3341, 1950) Water analysis was done with the familiar Karl Fisher method.
All of these substances -- uranium, fluoride, ammonia and peroxidic oxygen were identified in the precipitate that was collected from the separation means 35 (FIG. 1) through the foregoing analytic techniques.
The results of the foregoing analyses are as follows:
Table 1______________________________________Chemical Analysis and Molar Ratios for UO.sub.4.2NH.sub.3.2HF % Calc. for Molar Ratio UO.sub.4.2NH.sub.3.2HF % Found Found______________________________________U 63.3 61.4±0.1 1.00NH.sub.4 .sup.+ 9.6 9.8±0.1 2.11±0.04F 10.1 10.4±0.1 2.12±0.04peroxidic O 8.5* 8.8±0.1 2.14±0.04carbonate (as CO.sub.3 .sup.=) -- 0.7±0.1 --Fe -- 0.38±0.001 --H.sub.2 O -- 0.2±0.1 --______________________________________ *Two atoms of peroxidic oxygen permolecule of UO.sub.4.
The water and the carbonate are obvious impurities and some known formula that would fit the observed molar ratios was sought. No known compound fits the results of the foregoing chemical analyses. The formula UO 4 .2NH 3 .2HF, however, is entirely compatable with the above mentioned chemical analyses.
X-ray Powder Diffraction Analysis
Diffraction patterns for the precipitate, as illustrated in FIG. 3, were obtained with a Guinier camera. The X-rays were generated in a tube with a copper target. This target emits an X-ray radiation that has a specific frequency and wave length which is termed "K.sub.α 1 line." More specifically, this particular radiation is identified as "CuK.sub.α 1 radiation in which the radiation wave length (λ) is equal to 1.5405 Angstrom units (A)", where 1 Angstrom equals 10 - 8 cm.
With respect to the proof of the unique and novel chemical nature of the precipitate at the separation means 35 (FIG. 1) attention is once more invited to FIG. 3. As a starting point, the X-ray powder diffraction pattern is unambiguously indexed with the known powder diffraction pattern for UO 4 .4H 2 O. In order to convert the raw X-ray diffraction pattern data into some indication of the crystal structure for this new compound, a "least squares" mathematical analysis was applied to the X-ray data in a conventional manner. The least squares analysis indicated that the crystal lattice, or the structural arrangement of the atoms that form the individual crystals is "monoclinic". In passing, a monoclinic crystal structure is defined by three sides a, b and c, wherein; the included angles between sides a and b and sides b and c equal 90°, the included angle between sides a and c does not equal 90°, side c is less than or equal to side a in length and side b is arbitrary in length. The monoclinic arrangement of this new compound is shown in FIG. 4. Expressed in terms of conventional crystal classifications, the angle β between the horizontal side a and the vertical side c of the crystal is 93.39° ±0.001°. The angle γ that is formed between the two horizontal crystal crystal sides a and b is 90° and the lengths of the sides a, b and c are, respectively, 11.719±0.002A, 6.648±0.001A; and 4.225±0.001A. These crystal classification parameters are unique to this chemical compound and are not repeated in any other substance.
The results of the X-ray analysis that provided the raw data from which the crystal structure was developed is given in Table 2.
Table 2______________________________________Powder Diffraction Pattern of UO.sub.4.2NH.sub.3.2HF (CuK .sub.1radiation; λ= 1.5405 A)______________________________________d (A) I(obs.) hkl (est.)______________________________________5.85 200 100 broad 1104.23 001 203.53 201 203.47 111 203.37 310 50 1113.33 201 020 102.93 400 52.89 220 52.703 311 52.614 021 52.571 311 52.478 401 52.420 221 102.355 221 32.341 401 52.209 510 52.197 420 52.179 130 52.111 002 52.020 202 32.002 511 20 1121.983 421 31.963 112 31.945 202 10 diff 1311.926 330 10 1311.912 421 10 5111.829 312 31.812 601 31.781 022 31.773 331 11.760 402 11.748 312 51.731 601 5 diff1.682 620 101.662 040 5 diff1.621 710 31.609 530 31.598 240 31.591 621 31.569 512 11.556 422 11.545 041 3 diff1.535 621 11.522 132 51.504 241 3 diff1.484 711 10 5121.475 602 11.461 800 11.443 440 5 3321.403 332 1 diff1.375 113 1 diff1.356 801 5 1131.347 203 622 31.336 730 11.321 712 313 5 1501.305 042 3 5321.295 023 31.283 242 622 11.275 313 11.264 640 242 3 diff1.257 821 3 diff______________________________________
where the Miller indices hkl are well known notations used to identify the planes in a crystal lattice, see C. Kittel, Introduction to Solid State Physics, pg. 13, John Wiley & Sons, 1953, d is the separation between the planes that are characterized by the Miller indices and I is the relative intensity of a diffraction line with respect to the most pronounced line in the diffraction pattern.
In both UO 4 .2NH 3 .2HF and UO 4 .4H 2 O the essential structural framework is formed by UO 4 -units, with NH 3 ,+HF and H 2 O, respectively, occupying "interstitial" positions between these UO 4 units. It further appears from an analysis of the data that the nitrogen and fluorine atoms in the UO 4 .2NH 3 .2HF compound occupy the same lattice points that are occupied by the water molecule oxygen atoms in the UO 4 .4H 2 O with which the new compound has been compared.
This new chemical compound UO 4 .2NH 3 .2HF is a useful feed material for UO 2 production. The compound, moreover, is produced without generating environmental pollutants. In practice, the UO 4 .2NH 3 .2HF precipitate can be cycled back into UO 2 production in a number of ways. Typically, three of these processes are described below.
In the first technique, UO 4 .2NH 3 ,2HF is mixed with the AUC powder in the UO 2 conversion process. In this method the UO 4 .2HN 3 .2HF and AUC mixture is first calcined to UO 3 . Stoichiometric UO 2 in which there is exactly two oxygen atoms for each atom of uranium is produced from the calcined UO 3 , by burning or "reducing" all excess oxygen in the calcined UO 3 with hydrogen gas. Fluoride impurities present in the stoichiometric UO 2 are removed through pyrohydrolysis, that is, an application of steam to the material to produce easily separable HF. The stoichiometric UO 2 powder is spontaneously combustible in air, or "pyrophoric." Accordingly, this UO 2 is partially oxidized with a controlled amount of air to eliminate this pyrophoric quality. The result of this second oxidation is a stable nonstoichiometric compound of about UO 2 .08 to UO 2 .20.
In the second technique, the UO 4 .2NH 3 .2HF is heated at high temperatures (e.g., 750°C) in the presence of steam and air (i.e. calcined and pyrohydrolyzed). This procedure produces U 3 O 8 powder that has less than 100 ppm fluoride. The resulting U 3 O 8 can be blended, in varying amounts, with a stable UO 2 powder that is obtained from the AUC conversion for future processing.
In the third technique UO 4 .2NH 3 .2HF is dissolved in nitric acid HNO 3 ). The resulting uranyl nitrate solution is fed into the AUC precipitation. The precipitate is converted into stable UO 2 in the same manner as described in connection with the first technique.
Thus the invention provides not only an efficient secondary recovery process for extracting useful quantities of uranium from process effluents in a way that eliminates environmental pollutants, but it also provides a new and useful chemical compound.
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A process for treating the aqueous effluents that are produced in converting gaseous UF 6 (uranium hexafluoride) into solid UO 2 (uranium dioxide) by way of an intermediate (NH 4 ) 4 UO 2 (CO 3 ) 3 ("AUC" Compound) is disclosed. These effluents, which contain large amounts of NH.sub. 4 + (ammonium), CO 3 - - (carbonate), F - (fluoride), and a small amount of U (uranium), are mixed with H 2 SO 4 (sulfuric acid) in order to expel CO 2 (carbon dioxide) and thereby reduce the carbonate concentration. The uranium is precipitated through treatment with H 2 O 2 (hydrogen peroxide) and the fluoride is easily recovered in the form of CaF 2 (calcium fluoride) by contacting the process liquid with CaO (calcium oxide). The presence of SO 4 - - (sulfate) in the process liquid during CaO contacting seems to prevent the development of a difficult-to-filter colloid. The process also provides for NH 3 (ammonia) recovery and recycling. Liquids discharged from the process, moreover, are essentially free of environmental pollutants. The waste treatment products, i.e. CO 2 , NH 3 , and U are economically recovered and recycled back into the UF 6 →UO 2 conversion process. The process, moreover, recovers the uranium as a precipitate in the second stage. This precipitate is a new inorganic chemical compound UO 4 .2NH 3 .2HF [uranyl peroxide-2-ammonia-2- (hydrogen fluoride)].
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RELATED APPLICATIONS AND CLAIM OF PRIORITY
This application is a continuation-in-part of U.S. application Ser. No. 07/322,670, filed Mar. 13, 1989, now abandoned.
BACKGROUND OF THE INVENTION
For many years, enzyme assays and immunoassays have been successfully used in a wide variety of clinical, veterinary, and bio-analytical laboratory applications. Increasingly, as the availability of monoclonal and polyclonal antibodies has expanded, the range of applications to which these antibodies has extended include environmental monitoring applications (Vanderlaan et. al., 1988). Enzyme and antibody assay technology ahs been used to measure drug abuse, hormones, to monitor therapeutic drugs and to screen for environmental pollutants. These tests are generally simple to use, sensitive, and inexpensive. they are typically, however, colorimetric assays and are at best semi-quantative.
Biosensors offer an alternative format for the performance of established enzyme assays and immunoassays and create new opportunities for the application of established assays to continuous monitoring situations. Biosensors also offer distinct advantages (Taylor, 1987) in being very rapid (sub-second response rates), with condiderably improved limits of detection (typically ppb), are quantitative, and provide electronic outputs that may be integrated into simple data loggers or complex feedback control systems.
Parallel significant advances in microelectronics fabrication technology and biotechnology have created a unique interface of materials science and biology. Biosensors are measurement devices that detect and discriminate among molecules or substances of interest (analytes) through the recognition reactions of biologically active molecules (Lowe, 1985). The biosensor is a microelectronic device or chip, while biorecognition molecules are bioactive proteins. The biosensor measures the concentration of an analyte and produces a proportionate, electrical signal. In biosensors, biologically active molecules provide the needed molecular specificity and confer the ability to detect and discriminate among various substances to be analyzed. Microfabricated solid state devices provide the means for electrical transduction. Together and through their association, these two elements combine to produce an electrically based measurement signal that is the result of the physical chemical changes associated with biorecognition and serve as the raw output data of the biosensor test (Thompson and Krull, 1991).
FIG. 1 schematically illustrates the layout for a typical biosensor instrument. Typically, the biosensor instrument consists of three functionally distinct parts; the biotransducer or biosensor device, the device interrogator and signal processor, and the output device.
Biosensor devices are typically configured as shown in the schematic of FIG. 2. Biosensor devices typically contain two basic parts. The first part is an organic biorecognition layer that contains the biorecognition molecules. The second part is a microdevice which provides the electrical signal and is an electrical or electronically based component. Together, these components form the active element or biotransducer of the biosensor instrument. The biologically active component may be a thin organic film of enzyme, immunochemically active protein, stabilized receptor, a tissue slice, or a cell fragment. This part provides the molecular specificity o recognition of the analyte present in the test sample or process stream. The biologically active part of the transducer converts the analyte into another substance or produces some physical chemical change which can be detected by the electrically or electronically active part of the biotransducer. The electronically or electrically active part of the biotransducer accordingly produces a current or voltage change in response to the appearance of the product of the biological transmutation or conversion reaction. The current or voltage change is an analog signal which may be amplified locally before going on to the second part of the biosensor instrument--the signal processor.
Biosensor devices are integral components of biosensor instruments. The signal processor captures the signal from the biotransducer, may amplify, smooth or perform some mathematical operations on the data, then present it to the next part of the instrument--the output. The output section is responsible for presenting the acquired data in a form suitable for the senses and compatible with other information sources to produce sound and timely decision making by the end user.
This general description of biosensor technology encompasses a wide range of bioanalytical devices, some of which are pH or ion selective electrodes, while others are complicated optical devices.
Electroactive polymer biosensor devices must transmute the chemical potential energy associated with the concentration of an analyte into a proportionate, measurable, electrical signal. The specificity of these electroactive polymer biosensor devices is derived for the biorecognition reactions of immobilized enzymes, enzyme-linked antibody conjugates, and stabilized receptors. Several approaches to the use of electroactive polymers are possible. These are potentiometric, amperometric, chemoresistive, and methods based upon field effect phenomena. In all these methods the electroactive polymer serves as an active, functional, and integral part of the bio-transducer.
Potentiometric biosensor devices derive their responses from the changes in the steady state potential which accompanies the change in redox composition of the electroactive polymer film. This is a direct detection method not requiring the input of externally generated energy. Films may be free standing or supported by ohmic contact to a inert electrode. Changes in extent of oxidation are reflected in changes in the population of polaron o bipoloran states and accompanying counterion ingress. Thus electroactive polymer films therefore serve as ionophore containing membranes of ion-selective electrodes (ISEs). The membrane potential of the electroactive polymer is directly related to some potentiometrically measurable ionic product of the biorecognition reaction (Thompson et al., 1986). In general, all electroactive polymers display som measurable change in steady state or open circuit potential as a function of doping level. This is true over some specified range of redox composition.
Band-gap, p-type semiconducting polymers such as polyacetylene and polypyrrole can change their open-circuit electrode potentials through a maximum of the difference between the mid-gap energy (intrinsic semiconductor) and the conduction band edge, and typically, this change is between the mid-gap energy and the Fermi energy, E F -E CB (Morrison, 1980). For polyacetylene, the open circuit potential is an invariant 0.45V vs SCE for CH x compositions above the insulator to semiconductor/metal transition (ca. 4 mol % of dopant per --C═C--unit) (Guiseppi-Elie and Wnek, 1990). Thus the maximum voltage change (over all dopant compositions) associated with these materials is 1/2 the band gap, E g , or ca. 0.70 V. Direct potentiometric detection of nucleotides co-deposited in electropolymerized polypyrrole has been reported by Shimidzu (1987) and potentiometric measurements of the concentrations of various anions by electropolymerized polypyrrole films have been reported by Dong et. al. (1988). Both these works suggest interesting and unusual behavior of electroactive polypyrrole in potentiometric measurement mode. Since n-type semiconducting band-gap polymers are violently reactive in aqueous environments, their applicability to biosensors is necessarily without consideration.
Redox polymers such as poly(vinylferrocene) and poly(viologen) establish an open circuit potential which reflects the equilibria between oxidized and reduced forms of the redox-active moiety (Lewis et. al., 1984). These devices work by indirectly linking the biorecognition reaction to a change in redox composition of the film. Any signature redox active species which can alter the equilibrium at the polymer modified electrode surface provides a means for biotransduction. These systems all show behavior that can be predicted by the Nernst equation and electrochemical kinetics. Because potentiometric devices based on electroactive polymers are steady state devices they are subject to limitations arising from errors such as interfering ions, non-specific protein binding (Collins and Janata, 1982), surface charge adsorption, and the sensitivity limitations imposed by Band theory and the 59 mV/decade sensitivity of the Nernst equation (Thompson and Krull, 1991).
Amperometric biosensors formed from electroactive polymers ar by far the most common generic approach to biosensors (Janata and Bezegh, 1988). With such devices, two principles dominate: i) redox mediation and ii) electrocatalysis. Redox mediation implies the oxidoreduction of an electroactive species other than the on of interest. Umana and Waller (1986) used the amperometric reduction of iodine (I 2 +2e→2I) mediated through the Mo IV -catalyzed reaction of H 2 O 2 with iodide (H 2 O 2 +2H + 2I+2I→I 2 +2H 2 O) under aerobic conditions.l Iwakura et. al. (1988) achieved direct redox mediation with ferrocenecarboxylic acid under anaerobic conditions. Similar devices have since also been demonstrated by Caglar and Wnek (1991). In such devices the electroactive polymer functions simply as a retaining matrix for the mediator and is itself not actively involved in transduction. The related works of Heller (1990) and Hale et. al. (1991) use oligomers and polymers of ferrocene-based redox mediators as active participants to transduction (Gorton et. al., 1990). These are true transducer-active polymer films as they both mediate and directly transmute the redox activity of the enzyme to amperometrically discharged current at metallic or carbon paste electrode.
The simplest amperometric biosensors of this type are those based on the discharge of a redox active bi-products of the biochemical transmutation reaction. The early glucose biosensors which amperometrically discharged H 2 O 2 are of this type (Clark, 1987). There is evidence that electroactive polyaniline modified inert electrodes can electrocatalyze the reduction of ascorbic acid (Hepel, 1990) and hydrogen peroxide (Guiseppi-Elie and Wilson, 1990), both of which are associated with biochemical reactions. Polyaniline modified platinum electrodes have also been reported to electrocatalyze the oxidation of formic acid (Gholamian et. al., 1987). The potential for using electroactive polymer modified electrodes for electrocatalysis in Clark-typ amperometric biosensors is evident but little explored.
Chemoresistive biosensor devices based on electroactive polymer membrane films take advantage of the very large and rapid change in electrical conductivity which accompanies "doping" of the electroactive polymer (Baughman and Shacklette, 1990). The principle of operation in this approach is based on the measurement of biochemically modulated changes in the electronic resistance of the membrane film. The membrane films, fabricated on solid state devices, change their electrical impedance characteristics in response to the biological reactions with which they are associated. Chemoresistive biosensor devices are composed of a fully contiguous membrane film of electroactive polymer fabricated over the interdigit area of Interdigitated Microsensor Electrodes (IMEs) or array microelectrodes. IMEs generally have digit dimensions and separation distances which range from 1 to 20 microns. These dimensions are readily achievable with commonly available microlithography technology. The number of digits and the digit length together define the meander length for the device and this is selected to match the resistance range of the particular electroactive polymer being employed. The short separation distance and long meander length found on IMEs allow the generation of high electric fields with modest voltages while allowing effective work with highly resistive membrane materials. The device sensitivity is provided by the large (up to 12 orders of magnitude) (Frommer and Chance, 1986), dynamic ( ms - μs response) (Thackeray et. al., 1985) chemoresistance range of chemically sensitive, electroactive polymer membrane films.
Chemoresistive sensor devices based on electroactive polymer films were introduced by Paul et. al. (1985). These redox dependant chemoresistance devices emphasized voltage modulation of the chemoresistive response. Thackeray et. al. (1985) describe a device based on poly(3-methylthiophene) which illustrates a key strength of this method--The low detection limit (<10 -15 moles of oxidant) to elicit a response above noise level and the significant amplification possible with proper design of IME and fabrication of the chemically sensitive film (Lofton et. al., 1986). While the foregoing illustrates the general principles of chemoresistance detection the electroactive polymer films used were not conferred with biospecificity and are accordingly not biosensors. Taylor et al. (1988) report receptor-based biosensors using the chemoresistance principle but the polymers used were not electroactive (Taylor, 1989). Malmros et. al. (1987/88) describe a chemoresistance biosensor based on free-standing polyacetylene. This report suggests that the measured chemoresistance response was due primarily to changes in ionic resistance attendant to increases in the extent of wetting of Shirakawa polyacetylene upo doping with aqueous H 2 O 2 or I 2 . Chemoresistance biosensors have also been reported by Watson et. al. (1987/88) and Cullen et. al. (1990).
These films are well known to bridge substantial device scale distances (Focke et. al. 1989). Using established methods designed to confer general chemical and biospecificity to these films (Guiseppi-Elie, 1988) and using these devices in a kinetic mode (Karube, 1987) opens up additional possibilities for FETs (Garnier et. al., 1991).
While there have been a large number of prior art biosensors, it would be desirable to have a system and method which can be utilized for the interrogation capture and analysis of chemoresistive sensor responses.
It is thus an object of the present invention to provide a novel analytical method which can be utilized for the interrgogation, capture and analysis of chemoresistive sensor responses.
It is a further object of the present invention to provide novel components which together comprise an electroactive polymer sensor interrogation system.
It is still yet a further object of the present invention to provide chemical and biosensor devices formed from chemically modified and derivatized electroactive polymer films
It is still an additional object of the present invention to provide an analytical method for monitoring the time rate of change (kinetic) or extent of change (equilibrium) of the resistance of the electroactive polymer film as it spontaneously reacts with a redox active analyte to which it has been rendered specific
These and other objects of the present invention will become apparent from the following summary and detailed description which follow.
SUMMARY OF THE INVENTION
The present invention provides an analytical method for the interrogation, capture, and analysis of the chemoresistive sensor responses of chemical and biosensor devices using the electroactive polymers disclosed and claimed in co-pending U.S. application Ser. No. 07/322,676. Chemoresistive sensor responses are the changes in electrical resistance which result when an electroactive and electrically conducting polymer is made to react with a redox active analyte to which it is rendered specific.
This analytical method may be implemented using components which together comprise an Electroactive Polymer Sensor Interrogation System (hereinafter "EPSIS"). EPSIS comprises an analog electronic instrument with software that ar designed to work together to execute a sequenced series of steps for the extraction of these chemically or biochemically induced, electrically-based sensor responses. A system capable of carrying out the analytical methodology of the present invention is marketed as the Model 240 U EPSIS by AAI/Abtech of Yardley, PA.
The present invention is also directed to chemical and biosensor devices formed from chemically modified and derivatized electroactive polymer films. Previous inventions have described processes and the products resulting from the conferment of chemical and biological specificity to electroactive polymers. The present invention is directed toward the application of these devices to chemical and biosensor applications and to an analytical method for the use of these devices.
In one embodiment of this invention, chemical and biosensor devices are formed by the fabrication of electroactive polymer films on interdigitated microsensor electrodes. Films such a polypyrrole, polyaniline, and polythiophene are grown by electropolymerization from solutions of the corresponding monomer. Films are grown to bridge the interdigit space of the devices. Films may also be cast from solution or colloidal suspension, by dip-coating or spin-coating, where appropriate. Through various chemical modification and derivatization schemes (U.S. Pat. application Ser. No. 322,670) these devices may be functionalized and so conferred with chemical and/or biological specificity. The analytical method of this invention calls for monitoring the time rate of change (kinetic) or extent of change (equilibrium) of the resistance of the electroactive polymer film as it spontaneously reacts with a redox active analyte to which it has been rendered specific.
Key elements of the analytical method are:
(1) The use of an initialization potential which serves to establish a unique redox composition of the film and hence the set the electrical resistivity, open-circuit potential of the device.
(2) The use of very small or non-pertubating net voltage pulses, on the order of 5-25 mV, to interrogate the dynamically changing chemoresistance of the device.
(3) A voltage pulse sequence which floats of disconnects the sensor device during the pulse delay or OFF cycle.
(4) The measurement of the open circuit potential during the pulse delay or OFF cycle and the use of this measured potential to serve as the base potential to which subsequent pulse potentials are added.
The analytical method involves three sequenced phases resulting and an analytically significant result which is related to analyte concentration. These phases are Pre-Initialization, Initialization, and Interrogation. The Interrogation phase comprises three distinct steps to its execution; Voltage Pulse Application, Current Sample, and Device Float. The method of the present invention utilizes a real-time read of the open-circuit potential of the device versus the externally placed reference electrode, such as a Ag°/AgCl,3MCl - . This value of potential becomes an important part of the data record for the particular experiment and is used to qualify the integrity and suitability of the device for the subsequent steps.
The method then superposes an interrogation pulse voltage on the open circuit potential to inquire as to changes in electrical resistivity. In one example, a chemical sensor is formed from the fabrication of a fully contiguous film of electroactive polyaniline over the interdigit space of an interdigitated microsensor electrode (IME). The resulting device is shown to be responsive to hydrogen peroxide and to produce a linear response over the range 10 -7 to 10 -2 M H 2 O 2 in 0.2M HCl.
In a second example, a mediated chemical sensor is formed from the fabrication of a fully contiguous film of electroactive polypyrrole over the interdigit space of an interdigitated microsensor electrode (IME). The resulting device is shown to be responsive to the mediated concentration of iodine produced by the action of hydrogen peroxide on iodide ion in the presence of Mo.sup.(VI). This device is shown to responsive to hydrogen peroxide and to respond linearly over the range 10 -4 M to 10 -2 M H 2 O 2 in the presence of 10 -2 M I - and 10 -3 M Mo.sup.(VI) in pH 6.0, 0.1M phosphate buffered potassium chloride.
In still yet another example, a glucose biosensor is formed from the fabrication of a fully contiguous film of glucose-functionalized electroactive polypyrrole over the interdigit space of an interdigitated microsensor electrode. The resulting device is made to respond to the concentration of glucose through the biorecognition reaction of glucose oxidase. The device is shown to be responsive to a redox inactive molecule such as glucose through the biotransmutation reaction of glucose oxidase. A kinetic dose/response curve for the chemoresistive glucose biosensor based on the system (PPy/PVAVS/GOx) is shown to be linear for variations in glucose concentration over the range 0.1 to 20 μg/ml in pH 6.0, 0.1M phosphate buffered potassium chloride at 20° C.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an block diagram which illustrates the three basic elements of the archetypical chemical and/or biosensor instrument of the current invention.
FIG. 2 illustrates the functional elements of the chemical or biosensor device.
FIG. 3 illustrates the various designs for the chemical and biosensor devices formed from Electroactive Polymer Microsensor Electrode
FIG. 4 is a section view illustrating the various electrode connections to the chemical and biosensor cell.
FIG. 5 is a schematic of the Electroactive Polymer Sensor Interrogation System which may be utilized to perform the analytic method of the present invention.
FIG. 6A is a schematic illustration of the potentiometric Pre-Initialization Circuit employed by EPSIS during Phase of operation.
FIG. 6 is a schematic illustration of the potentiostatic Initialization Circuit employed by EPSIS during Phase 2 of operation.
FIG. 6C is a schematic illustration of the Sensor Interrogation or Chemoresistance Measurement Circuit employed by EPSIS during Phase 3 of operation.
FIG. 7 is a graph showing the electrical resistivity and the anodic charge capacity (measured by potential step coulometry) of polyaniline films as a function of the impressed potential vs SCE in 0.2M HCl.
FIG. 8 is a graph showing the electrical resistivity (expressed as coulombs of charge) and the poise potential in V v SCE versus the externally impressed potential vs SCE in pH 6.0. 0.1 M phosphate buffered potassium chloride.
FIG. 9 is a graph showing a typical differential chemoresistive response of a polyaniline-based sensor to 1 mM hydrogen peroxide in 0.2M HCl relative to its response in 0.2M HCl.
FIG. 10 is an illustration of a typical chemical sensor reaction, SCHEME 1.
FIG. 11 is a graph showing the kinetic chemoresistive responses of the polyaniline-based sensor illustrated in FIG. 9 to various concentrations of hydrogen peroxide in 0.2M HCl.
FIG. 12 is an illustration of a typical mediated chemical sensor reaction, SCHEME 2.
FIG. 13 is a graph showing the kinetic chemoresistive responses of a polypyrrole-based sensor (PPy/PVAVS) to various concentrations of solution phase hydrogen peroxide in the presence of I - and Mo.sup.(VI) at 20° C.
FIG. 14 is an illustration of a typical mediated biosensor reaction, SCHEME 3.
FIG. 15 is a graph showing the kinetic dose/response curve for the chemoresistive glucose biosensor based on the system (PPy/PVAVS/GOx) for variations in glucose concentration over the range 0.1 to 20 μg/ml in pH 6.0, 0.1M phosphate buffered potassium chloride a 20° C.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method for obtaining analytically significant responses from chemical and biosensor devices based on electroactive polymer films. In the analytical method of the present invention, the use of an initialization potential to fix the starting redox composition, and consequently also fix the ionic and electronic resistivity and the electrode potential of the device, the use of non-pertubating voltage pulses for interrogation, the use of a float or disconnect period between the application of voltage pulses, the measurement and update of the device potential during each float period, and the use of this measured float potential to establish the new pulse potential for subsequent pulse application are utilized.
The initialization potential is potentiostatically applied for a period sufficiant to fix the redox composition of the polyme film. This potential may be anodic or cathodic and may fix the composition to be predominantly oxidized and conducting or predominantly reduced and non-conducting. Typically, the potential is chosen to reduce the polymer film, render it non-conducting or resisitive, and fix its redox composition to be predomninantly reduced. It is understood by those skilled in the art, that for this class of material such initialization also fixes the color of the device film as well as the geometric dimensions of the film. The length of time required for initialization depends upon the nature of the film, the thickness of the film, the total active or exposed area of the film in contact with the electrolyte, and the nature of the electrolyte. The initialization period is typically 8 to 30 secs and may be 1 sec to 3 mins. Alternatively, initialuization may be made to proceed until a limiting background current is achieved or a particular threshold of current achieved.
Immediately subsequent to initialization, an interrogating voltage pulse is applied to the device. This voltage pulseis intended to reveal the electrical conductivity of the electroactive polymer film. This pulse must therefore be non-pertubing to the film and should not itself serve to alter the redox composition or conductivity of the film. The voltage pulse may be in the range + or -5 to 25 mV and may be 1 to 100ms duration and is typically 10 mV for a 50ms duration. Larger voltages may be applied and for longer durations. The resulting current indicates the electrical conductivity of the film bearing device and ma be mathematically converted to absolute or normalized resistivity or conductivity.
At the end of the interrogating voltage pulse period the device is disconnected form the voltage source, is permitted to electrically float, and to spontaneously react with the analyte species of its test environment. During this float period the device responds with a change in redox composition, ionic and electrical conductivity, and electrode potential. The float period is typically ten times the pulse period and may be 10ms to 1000ms duration and is typically 500ms. During the float period, the open circuit or poise potential of the individual electrodes of the device are measured versus the externally place Ag/AgCl,3MCl - reference electrode. No current is drawn or voltage applied during this measurement. The measured float potential is used as the base potential value for the application of the subsequent interrogation voltage pulse.
The 10 mV pulse potential is added to the float potential such that the subsequentially applied potential differs from th device open circuit potential by only the value of the interrogation pulse potential. As an example, if the measured open circuit potential of the device during the float period is found to be 345 mV vs the Ag/AgCl,3MCl - reference electrode and the desired pulse voltage is 10 mV, then the subsequent voltage pulse applied to the device is 355 mV vs Ag/AgCl,3MCl - for a net voltage applied of 10 mV.
Chemical and biosensor devices are formed from electroactive polymer films of polyaniline and polypyrrole and are shown to produce analytically significant results. This invention is further illustrated by reference to the following non-limiting examples. These examples serve to illustrate the wide utility of the method as it is successfully applied to chemical as well as biosensors.
INTERDIGITATED MICROSENSOR ELECTRODES--IME Devices
Interdigitated Microsensor Electrodes (IMEs) are inert, array microelectrodes designed for the simultaneous interrogation of the electrical, electrochemical, and optical properties of thin polymer films and coatings. Microfabricated from magnetron sputtered gold over and an adhesion metal of chromium or titanium, on an insulating ceramic substrate of glass, quartz, lithium niobate or passivated silicon these devices were developed for application to chemoresistive biosensor assays. The IME devices are inert, rugged, durable and versatile and occur in three different electrode configurations shown in FIG. 3; Monolith (M), Combined Differential (CD), and Full Differential (FD). These IMEs consist of 50 digit or finger pairs. Each digit is 0.4985 cm long and 15 μm wide and is separated by 15 μm spaces on a chip which is typically 1.0 cm(W)×1.5 cm(L)×0.05 cm(T) with a total exposed metal area of 0.569 cm 2 .
ELECTROACTIVE POLYMER MICROSENSOR ELECTRODES--EPME Devices
Electroactive Polymer Microsensor Devices (EPMEs) serve as the underlying transducers for the fabrication of biosensor devices. Transducer-Active Films based on polyaniline, polypyrrole, polythiophene, or other electroactive polymer is fabricated as a fully contiguous film over the device. Film fabrication occurs by electropolymerization of aniline, pyrrole or thiophene monomer from electrolyte solutions. The electropolymerization medium contains polymeric counter-anions and supporting electrolyte and may contain surfactants, levelling agents, bioactive proteins, catalysts and other agents directed at enhancing the performance or properties of the film. Electropolymerization is carried out directly at IME devices resulting in EPME devices.
The Electroactive Polymer Sensor Interrogration System (EPSIS)
Electroactive polymer sensor interrogation was accomplished with the EPSIS 240 U system. EPSIS is a sensor interrogation, data capture, and analysis instrumentation package for the development of biosensor assays using Biospecific EPME devices. The EPSIS 240 U unit is commercially available through AAI/Abtech, Inc., 1273 Quarry Commons Drive, Yardley, PA 19067. Wnile the present analytical methodology was carried out using the AAI/Abtech EPSIS 240 U system, it is to be appreciated that the focus of the present invention is on the analytical methodology and that this methodology may be performed by a wide variety of apparatus. EPSIS uses the Biospecific EPME device in a biosensor cell comprising a platinum counter electrode and an externally placed miniature Ag/AgCl/3MCl - reference electrode. Both the counter electrode and the reference electrode functions may be fabricated on the same EPME device chip which carries the biospecific agents. For the purpose of illustration and for experiments performed here, these are shown as separate electrodes in the biosensor cell arrangement illustrated in FIG. 4.
EPSIS instrumentation consists of the EPSIS 240 U sensor interrogator and EPSISOFT™ software installed on a PC XT computer outfitted with a 12 bit AD card. A scematic represenation is shown in FIG. 5. The EPSIS 240 U consists of a potentiometric circuit, a potentiostatic circuit and a chemoresistance interrogation circuit illustrated in FIGS. 6A-6C. These instrument functions are integrated into a sensor interrogation system designed to reveal the chemoresistance dynamics of electroactive polymer films as they respond to biologically modulated changes in electrical conductivity.
Because the biospecific, transducer-active films display very dramatic changes in electrical impedance as a function of extent of oxidoreducton, the biospecific EPME device may be used as a highly sensitive biotransducer. FIG. 7, as an example, illustrates the changes in the electrical resistivity and the anodic oxidative capacity of electroactive polyaniline films as a function of electrode potential in 0.20M HCl. Similar results are shown for polypyrrole (Chidsey and Murray, 1986). The method senses the kinetic and equilibrium changes in chemoresistance of these devices as the resistivity of the device is modulated by reaction with the signature products of the biorecognition molecules with which the area derivatized.
The general procedure for the interrogation of the electroactive polymer microsensor devices (EPMEs), interdigitated microsensor electrodes (IMEs) or other chemoresistive device based on electroactive polymer films, involves three separate, sequenced phases that are integrated into a sensor analysis scheme. These phases are listed below.
1. Pre-Initialization Phase
2 Initialization Phase
3. Interrogation
The three phases, executed in sequence, represent a single complete cycle for the successful extraction of raw sensor response data. The raw data extracted should be relatable to the desired measurement objective, i.e. the activities (chemical potential) of analytes to which th device is sensitive. Subsequent data reduction, analysis, and presentation follows these two phases. Pre-Initialization Phase: Initially, a real-time read of the open circuit potential of the device versus a suitable externally placed reference electrode such as a Ag°/AgCl, 3MCl - .
This potential serves to qualify the device for subsequent initialization and interrogation and therefore serves as a diagnostic tool as to the suitability of your device for further experimentation.
During pre-initialization all two, three or four electrodes of the microsensor device are internally shorted to serve as the common input for the potentiometric circuit shown on this is illustrated in FIG. 6A. The potentiometric circuit is a high input impedance FET operatinal amplifier.
Electrode potential, the initialization potential, to the internally shorted microsensor device. All of the two, three or four electrodes of the microsensor device are simultaneously polarized to this potential. The device is maintained at this fixed potential, relative to the externally placed reference electrode for the user specified length of time, the Initialization Period.
Initialization conditions or reconditions the microsensor device to an initial or starting extent of oxidation or reduction from which accurate sensor response measurements may be made during the subsequent interrogation phase. During initialization, the chemically sensitive polymer film may be partially or completely oxidized or reduced. This process, in effect, standardizes the starting electrical conductivity of the chemoresistive film. The instantaneously measured ope circuit rest potential of the device following initialization is hypothetically the same as the initialization potential. Initialization therefore serves to establish a common precondition which is the same for each device, the same from one device to another, and the same from one measurement to another with the same device.
During initialization all two, three or four electrodes of the microsensor device remain temporarily shorted as EPSIS electronically switches from a potentiometric to a potentiostatic mode and the initialization potential is app ied. This configuration is illustrated in FIG. 6B. The applied initialization potential is referenced to a suitable, externally placed reference electrode, such as SCE or Ag Ag°/AgCl. The initialization currrent is carried by a suitable inert, counter or auxiliary electrode. The VALUE of potential used is dependent upon the analyte to be measured, the background environment or matrix of this analyte, the redox characteristics of the chemically sensitive film of the device, and the extent of oxidation/reduction desired for this conditioning. Initialization is a redox process that involves facile electron transfer and results in a standardized chemoresistive film.
The chemoresistive microsensor device is then as to its dynamically changing state of electrical conductivity (chemoresistance). This it achieved by applying a pulsed DC voltage between the individual electrodes of the microsensor device and sampling the resulting current.
Interrogation probes the device for its electrically based response to the externally derived chemical or biological stimuli. The stimulus is in all cases the chemical potential of the analyte. The device response is a change in its electrically based material property, modulated by the chemical potential of the analyte under test. Interrogation reveals raw data on the electrical condition of the device and in particular is concerned with either the extent of variation of the resistive property of the device from its initialization condition or with the time rate of variation of the resistance of the device away from its initialization condition.
During interrogation as shown in FIG. 6C, the two, three or four leads of the microsensor device are temporarily disconnected. The now independent leads give rise to two separate interrogation circuits that share a common input electrode, COM(1,2)3 (in a bridge configuration). In this electrode configuration, the pulsed DC voltage is applied between COM(1,2)3 and ANAI and simultaneously between COM(1,2)3 and REF2. The microsensor device portion of the interrogation circuit is treated as a complex impedance from which we desire to know only of the equivalent DC resistance. The desired mode of interrogation is a pulsed square wave technique. During interrogation a discontinuous pulse.voltage train is applied between the common electrode, COM (1,2)3, and ANA1 and REF2. The voltage pulse should be small and non-perturbing (approx. 25 mV). The voltage pulse is applied relative to the open circuit potential of the device and is superposed on the open circuit potential. The duty cycle is established such that the time between pulses is long compared to the applied pulse width, typically 10 times.
The pulse that is applied may be positive or negative, but should not be an alternating positive and negative value. The duty cycle of the pulse must be sufficient to allow for the dissipation of any Faradaic or capacitative charging in the device.
During the voltage pulse delay period of the interrogation cycle, the electrodes of the microsensor device are briefly reconnected to provide a measurement of the open circuit or rest potential. The electrode configuration is the same as the connect or potentiometric mode of the pre-initialization phase. This open circuit potential serves as the referenced basis for the subsesquent voltage pulse. The open circuit potential of the device is measured at the end of each pulse delay. This potential then serves as the referenced basis for the subsequent pulse. This cycle is repeated again and again for the number of cycles selected for interrogation and until the end of the experiment. The resulting interrogation current is sampled over a fixed period of the applied voltage pulse. Current sampling in this manner negates the contribution of any current transients that may result from Faradic charging processes or other polarization processes in the device or in the background electrolyte. The sampled current is directed to a current-to-voltage converter, then integrated and presented as coulombs of charge over the time base.
The external sensitivity setting yo select will be determined by a number of experimental variables; the thickness of any chemoresistive film fabricated upon the sensor device, the concentration of electroactive species in the vicinity of the microsensor device, the active device area (and to some extent, its shape), the pre-integration delay and the integration period. The selection of too large an electrode area or too long an integration period--both of which may lead to amplifier saturation and to unusable output signal--are common experimental errors.
EXAMPLE 2
Electropolymerization of aniline (An) and cyclic voltammetric characterization of polyaniline (PAn) films were carried out using an EG&G PAR 173 Potentiostat/Galvanostat outfitted with a PAR 179 Digital Coulometer. Where needed, potentiodynamic sweeps were accomplished by interfacing the PAR 173 to a PAR 175 Universal Programmer. Cyclic voltammograms were recorded on an Esterline Angus XYY' 540 Recorder. Aniline (C 6 H 5 NH 2 ) was supplied by Aldrich and used after distillation under reduced nitrogen pressure. The solvents acetone and 2-propanol were supplied by Aldrich and used as supplied. Ominsolve water was supplied by VWR Scientific. Hydrogen peroxide was supplied by Sigma. Phosphate (0.1M) buffered potassium chloride (pH 7.2) solutions were prepared according to procedures of the Handbook of Physics and Chemistry. Pt foil electrodes were fabricated in these laboratories and saturated calomel electrodes (SCE) wer supplied by Fisher.
Electropolymerization was done at Interdigitated Microsensor Electrodes (IMEs) Model 1550-CD-P. The IME 1550-CD-P devices were cleaned in a Branson 1200 Ultrasonic Cleaner by sequential washing --first in acetone, followed by 2-propanol and finally in Omnisolve triply distilled water. Chemically cleaned microsensor devices were then made the working electrode in a three electrode electrochemical cell in which a similarly cleaned Pt foil electrode served as the counter electrode and an SCE served as the reference electrode. Cathodic cleaning of the IME 1550-CD-P was carried out in pH 7.2 phosphate buffered potassium chloride by cycling between -2.0V and -1.2V vs SCE for eight minutes. To promote adhesion of the electroactive polyniline film, the cathodically cleaned device was subsequently immersed for 30 minutes in a freshly prepared 0.2mg/ml solution of 4-aminothiophenol (Aldrich) in Omnisolve water followed by rinsing in Omnisolve water. Polyaniline films were fabricated by electropolymerization from aqueous solutions of aniline (An) monomer in the presence of HCl. Films were fabricated potentiostatically at potentials of 0.65V-0.8 V and typically was 0.65 V vs SCE or potentiodynamically over the range -0.2 to +0.65 V vs SCE at 50 mV/sec.
Electropolymerization solutions were typically 1M aniline in 0.2M HCl in triply distilled water. The result in all cases was a fully contiguous film of electroactive polyaniline fabricatd over the interdigit areas and adhered to a 1550-CD-P EPME device.
EXAMPLE 3
Electropolymerization of pyrrole (Py) and cyclic voltammetric characterization of polypyrrole (PPy) films were carried out using an EG&G PAR 173 Potentiostat/Galvanostat outfitted with a PAR 179 Digital Coulometer. Where needed, potentiodynamic sweeps were accomplished by interfacing the PAR 173 to a PAR 175 Universal Programmer. Cyclic voltammograms were recorded on an Esterline Angus XYY' 540 Recorder. Pyrrole (C 4 H 4 NH), potassium iodide, ammonium molybdate(VI) tetrahydrate, and the solvents; acetone, 2-propanol, were supplied by Aldrich and used as supplied. Hydrogen peroxide was supplied by Sigma. Phosphate (0.1M) buffered potassium chloride (pH 6.0) solutions were prepared in the standard way. Pt foil electrodes were fabricated in these laboratories and saturated calomel electrodes (SCE) were supplied by Fisher. Electropolymerization was done at Interdigitated Microsensor Electrodes (IMEs) Model 1550-CD-P. The IME 1550-CD-P devices were cleaned in a Branson 1200 Ultrasonic Cleaner by sequential washing --first in acetone, followed by 2-propanol and finally in Omnisolve triply distilled water. Chemically cleaned microsensor devices were then made the working electrode in a three electrode electrochemical cell in which a similarly cleaned Pt foil electrode served as the counter electrode and an SCE served as the reference electrode. Cathodic cleaning of the IME 1550-CD-P was carried out in pH 7.2 phosphate buffered potassium chloride by cycling between -2.0V and -1.2V vs SCE for eight minutes.
To promote adhesion of the electroactive polypyrrole films, the cathodically cleaned device was subsequently immersed for ca. 1 hr in a freshly prepared 100μg/ml solution of potassium p-toluenethiosulfonate (Aldrich) in Omnisolve water followed by rinsing in Omnisolve water. Polypyrrole films were fabricated by electropolymerization from aqueous solutions of pyrrole (Py) monomer in the presence of poly(vinylacetamide-vinylsulphonate, 60:40) (PVAVS) at potentials of 0.65V-0.8 V vs SCE. Electropolymerization solutions were typically 10 -2 M pyrrole in triply distilled water. The poly(vinylacetamide-vinylsulphonate 60:40) was of MW 20,000-80,000 supplied by Polysciences and was prepared to a final concentration which varied from 10 -3 to 10 -2 M in repeat units. Where needed, ammonium molybdate hexahydrate was also added to the electropolymerization solution to produce a final concentration which was 10 -3 M Mo.sup.(VI). The result in all cases was a fully contiguous electroactive polymer blend of PPy/PVAVS fabricated over the interdigit areas and adhered to a 1550-CD-P EPME device.
EXAMPLE 4
The EPME device is conferred with appropriate biospecificity for application as a biosensor. By conferring biological specificity to the device, the materials property change of the transducer-active polymer film may be linked directly or indirectly to the concentrations of specific analytes in the vicinity of the device. A contemporary problem in biosensor R&D is the development of approaches, methods and techniques for conferring biospecificity of response to these chemically sensitive films. Approaches based on the use of macrocycles, permselective membranes, electrochemical pre-concentration techniques are used to confer general chemical specificity. Approaches based on the use of enzymes, enzyme-linked antibodies, and stabilized receptors give rise to a wide range of possible chemoresistive biosensors. The conferment of biospecificity to the transducer action of these transducer-active polymer films is readily achieved by derivatization. Derivatization methods may based on adsorption, occlusion, codeposition and specific immobilization of bioactive molecules to these films. Methods for the surface modification, functionalization, and derivatization by specific immobilization of biologically active molecules to the surfaces of transducer-active polymers are easily developed and applied by the methods set forth in U.S. application Ser. No. 322,670 incorporated herein by reference.
Biospecificity was conferred to electroactive polypyrrole (PPy) films by electropolymerization of pyrrole (Py) monomer in the presence of the enzyme glucose oxidase (GOx) and the polymer poly(vinylacetamide-vinylsulphonate, 60:40) (PVAVS) at potentials of 0.65V-0.8 V vs SCE. Electropolymerization solutions were typically 10 -2 M pyrrole in triply distilled water. The GOx was Aspergillus niger Type VII-S of 129K units/g activity (Sigma) prepared to a final concentration of lmg/ml. The poly(vinyl acetamide-vinylsulphonate 60:40) was of MW 20,000-80,000 supplied by Polysciences and was prepared to a final concentration which varied from 10 -3 to 10 -2 M in repeat units. Where needed, ammonium molybdate hexahydrate was also added to the electropolymerization solution to produce a final concentration which was 10 -3 M Mo.sup.(VI). The result in all cases was a fully contiguous electroactive polymer blend of PPy/PVAVS/GOx fabricated over the interdigit areas and adhered to a 1550-CD-P EPME device.
EXAMPLE 5
General Chemical Sensor Response
Polyaniline-based sensor devices prepared according to Example 2 were evaluated for their chemically induced sensor responses using the EPSIS system Described in Example 1. The three step interrogation phase of EPSIS is repeated for a user-selected number of pulse cycles applied in sequence. The integrated device current for each pulse is then plotted directly to the data display area of the EPSISOFT Main Menu Screen and is shown as microcoulombs of charge versus interrogation time in seconds. A typical chemoresistive sensor response of a polyaniline membrane film to 1 mM H 2 O 2 in 0.2M HCl along with a similar blank response (0.2M HCl) is displayed in FIG. 9. The response is for the PAn film initialized at -100 mV vs Ag/AgCl,3MCl - for 30 sec and interrogated at 10 mV pulse potential with a pulse width of 50ms and rest period of 500 ms. The Figure shows the response obtained over 164 such three-step, pulse cycles or for a total of 90.7 sec. Typically there is a brief induction period followed by a sharp rise in the chemoresistance of the film. Exploration (in 50 mV increments) of various initialization potentials, from the open circuit potential of the mixed emeraldine base (0.43 V vs Ag/AgCl,3MCl - ) down to the fully reduced leucoemeraldine base (-0.30V vs Ag/AgCl,3MCl - ), produced the largest kinetic response for initializations at -0.1V vs Ag/AgCl,3MCl - . Initialization at -100 mV vs Ag/AgCl,3MCl - reduces the PAn film and sets its equilibrium redox composition and attendant electrical conductivity according to FIG. 7. The time rate of change of the electrical conductivity of PAn film appears to be largest from this composition. Removal of this potential allows the film to spontaneously react with the hydrogen peroxide in its immediate environment as shown in FIG. 10, Scheme I. Subsequent immediate three-step, DC pulse interrogation reveals the concomitant changes in electrical conductivity of the film as it reacts with hydrogen peroxide and modulates its properties.
At the end of this interrogation cycle the.membrane film may be re-initialized and a similar response reproducibly obtained. Kinetic response data is derived for the initial rate of change of the chemoresistive response. Ideally, this is the initial slope of the response curve or it may be the amount of change after a specified period of interrogation time. The latter approach is used to analyze the kinetic responses of PAn films to various concentrations of H 2 O 2 FIG. 9 shows the sensor calibration curve of differential response rate obtained for concentrations over the range 10. -7 to 10 -2 M H 2 O 2 in 0.2M HCl.
The chemoresistive PAn devices are seen to be linear over the range 10 -7 to 10 -2 M H 2 O 2 in 0.2M HCl with good sensitivity and a detection limit which is below 10 ; M H 2 O 2 . The stability of these devices is of paramount importance if they are to be used commercially and in continuous monitoring applications. Preliminary evidence from cyclic voltammetric characterization of PAn films suggests that the device performance may be altered by continuous exposure to high concentrations (>10 -2 M) of hydrogen peroxide.
EXAMPLE 6
Biospecific responses result from linking the chemoresistive device with the biorecognition reaction of a biologically active molecule. The simplest demonstrable case is that for an oxidoreductase enzyme such as glucose oxidase which produces hydrogen peroxide and hence elicits a chemical response similar to that described preceding. The direct reaction of hydrogen peroxide with polypyrrole and polyacetylene has been found to favor chemical oxidation over charge transfer reaction. For this reason mediation is found to be necessary. FIG. 12, Scheme II, shows the approach used by Umana and Waller (1986) and applied here to chemoresistive signal detection.
I this scheme hydrogen peroxide reacts with iodide in the Mo.sup.(VI) catalyzed generation of iodine. Iodine then reacts with the polypyrrole film effecting an increase in its electrical conductivity. In this scheme the polypyrrole is a direct participant to transduction as its electrical properties are indirectly modulated by redox charge transfer with the analyte of interest. Test solutions were prepared to 10 -2 M I - and 10 -3 M M Mo.sup.(VI) in 2 ml volumes of pH 6.0 phosphate buffer. Incremental additions of hydrogen peroxide produced the calibration plot shown in FIG. 10.
The chemoresistive system PPy/PVAVS is seen to be capable of detecting hydrogen peroxide down to 10 -4 M with good sensitivity. This system could therefore be used to detect the non-redox-active molecule glucose through the biorecognition reaction of the enzyme glucose oxidase.
EXAMPLE 7
The Glucose Biosensor
Glucose oxidase is a very stable, structurally rigid glycoprotein with an approximate globular diameter of ca. 86 A (Nakamura, et. al., 1976). The two redox active Flavin Adenine Dinucleotide (FAD/FADH2) centers of the enzyme are located deep within the glycoprotein shell (Worthington Manual, 1977). For this reason, direct charge transfer between these redox centers and the redox active polymer films of the current biosensor devices is not possible (Heller and Degani, 1987). However, use can be made of the reactions which serve to couple the biorecognition reaction of the enzyme with the biospecific hydrogen peroxide response described preceding.
As shown in FIG. 14, Scheme III, glucose oxidase readily oxidizes glucose to gluconic acid while the redox active FAD cofactor is reduced to FADH 2 . Under aerobic conditions the FAD is regenerated by solution phase, diffusible, molecular dioxygen which is itself reduced to hydrogen peroxide. In the current biosensor device, the hydrogen peroxide is nascently produced within the polymer matrix where it, oxidizes the electroactive polymer from its initialized or reduced redox composition to a more conducting redox composition. The dynamically changing chemoresistance of the device is followed as described previously. Biospecific chemoresistive responses of glucose biosensors formed from electroactive polypyrrole and conferred with the biospecificity of the enzyme glucose oxidase (PPy/PVAVS/GOx) were obtained for films initialized at -250 mV vs Ag/AgCl,3MCl - for 60 sec followed by interrogation with a 10 mV pulse potential of pulse width of 50ms and rest period of 500 ms. The responses show an initial quiescent period (corresponding to the blank or background response) prior to addition of the substrate dose. Addition of the substrate is followed by a further brief induction period then by rapid change in the device chemoresistance. Response saturation occurs after about two minutes. The kinetic response taken as the initial rate of change of chemoresistance following dose addition was measured for various glucose concentrations over the range of 0.1 to 20.0 mg/1 and is presented in FIG. 11 as a calibration plot. A linear relationship was observed between the initial rate and the logarithm of the glucose concentration in the range 0.1 to 20 μg/ml glucose.
Glucose biosensor probes prepared in the above manner were found to be stable for up to six weeks when stored at 5° C. in pH 6.0 phosphate buffered potassium chloride. The leaching of GOx from the membrane film appears to be the major source of reduced activity. Methods to specifically immobilize the enzyme are being developed.
While the present invention has been described with reference to the enclosed Figures and detailed description, it is to be appreciated that other embodiments fulfill the spirit and scope of the present invention, and that the true nature and scope of the present invention is to be determined with reference to the claims appended hereto.
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The change in electrical resistance of an electroactive polymer such as polypyrrole, polyaniline or polythiophene when it reacts with an analyte is used to measure the analyte. The open circuit electrical potential of an electroactive polymer film is measured and an electrical potential is applied to the polymer film relative to a reference electrode to oxidize or reduce the polymer film to provide an initial reduced or oxidized state. Then the electrical resistance of the polymer film is measured in the absence of an analyte and the electrical resistance is again measured while the polymer film reacts with the analyte. The analyte concentration is determined from the rte and total amount of electrical resistance change. The electrical resistance is preferably measured by applying a to the polymer film a discontinuous non-perturbating voltage pulse, removing the voltage for a period, making a measurement of open circuit potential and applying a subsequent discontinuous nonperturbating voltage pulse relative to the open-circuit potential. In measuring glucose as the analyte, reaction of glucose with glucose oxidase contained by the polymer film produces hydrogen peroxide which oxidizes the polymer film and makes it more conductive.
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BACKGROUND
[0001] 1. Field of Invention
[0002] The invention is directed to a downhole clean-up tool or junk basket for use in oil and gas wells, and in particular, to downhole clean-up tools that are capable of creating a hydraulic barrier within the wellbore annulus above the collection member to facilitate capture of debris flowing within the wellbore annulus.
[0003] 2. Description of Art
[0004] Downhole tools for clean-up of debris in a wellbore are generally known and are referred to as “junk baskets.” In general, the junk baskets have a screen or other structure that catches debris as debris-laden fluid flows through the screen of the tool. Generally, this occurs because at a point in the flow path, the speed of the fluid carrying the debris decreases such that the junk or debris falls out of the flow path and into a basket or screen.
SUMMARY OF INVENTION
[0005] Broadly, downhole tools for clean-up of debris within a well comprise a mandrel and a collection member for capturing debris within the wellbore. A fluid flow member for creating a hydraulic barrier above an opening of the collection member is operatively associated with the mandrel. Creation of the hydraulic barrier facilitates movement of the debris laden fluid within the wellbore into the collection member by restricting upward movement of the debris laden fluid. In one particular embodiment, the fluid flow member includes one or more ports disposed above the opening of the collection member, at least one of the ports being oriented to expel a fluid flowing down the bore of the mandrel into the wellbore annulus to create the hydraulic barrier.
BRIEF DESCRIPTION OF DRAWINGS
[0006] FIG. 1 is a partial cross-sectional view of a specific embodiment of a downhole tool disclosed herein.
[0007] FIG. 2 is a partial cross-sectional view of the downhole tool shown in FIG. 1 disposed in a tool string and disposed in a wellbore.
[0008] While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0009] Referring now to FIGS. 1-2 , in one particular embodiment, downhole tool 30 comprises mandrel or body 31 having upper end 32 , lower end 33 , and bore 34 defined by inner wall surface 35 . Both upper and lower ends 32 , 33 include threads 39 for releasably connecting downhole tool 30 within a tool or work string (not shown in FIG. 1 ). Bore 34 runs the entire longitudinal length of body 31 . Bore 34 permits a fluid flowing down the tool string to pass through downhole tool 30 where it can ultimately be expelled from the tool string into the wellbore to facilitate a downhole operation such as milling. Upon being expelled into the wellbore, the fluid travels up the wellbore annulus carrying debris so that it can be captured by downhole tool 30 .
[0010] Downhole tool 30 captures the debris within collection member 40 . As shown in the embodiment of FIGS. 1-2 , collection member 40 included upper end 41 and lower end 42 . Upper end 41 includes one or more openings 43 for receiving debris laden fluid. Lower end 42 is closed so that debris is captured within cavity 44 . One or more ports 46 are disposed around collection member 40 to permit fluid and small debris to flow out of cavity 44 . Thus, port(s) 46 facilitate circulation of debris laden fluid into and out of cavity 44 so that debris that is too large to pass through port(s) 46 is captured within cavity 44 .
[0011] To facilitate capturing debris within cavity 44 , downhole tool 30 includes one or more fluid flow members to create a hydraulic barrier within the wellbore annulus above opening(s) 43 . Creation of the hydraulic barrier restricts the upward movement of the debris laden fluid within the wellbore annulus. As a result, more debris laden fluid is directed into opening(s) 43 so that debris can be captured within cavity 44 . In the embodiment of FIGS. 1-2 , the fluid flow member that creates the hydraulic barrier is one or more ports 37 . Port(s) 37 are in fluid communication with bore 34 so that a portion of the fluid flowing through bore 34 is directed out of port(s) 37 into the wellbore annulus.
[0012] Although each port 37 can be shaped and sized as desired or necessary to create the hydraulic barrier, in certain embodiments, one or more of ports 37 include a jet nozzle to facilitate creation of the hydraulic barrier. In addition, one or more of ports 37 can be disposed at an angle that is perpendicular to a longitudinal axis of downhole tool 30 . Alternatively, one or more ports 37 can be disposed at an acute angle, oriented in a downward direction such as shown in FIGS. 1-2 .
[0013] Referring now to FIG. 2 , in operation, downhole tool 30 is placed in tool string 14 and lowered to the desired location within casing 12 of wellbore 10 . A fluid is flowed or pumped down tool string bore 16 into mandrel bore 34 . A portion of the fluid flowing through mandrel bore 34 is directed through ports 37 into wellbore annulus portion 18 as indicated by arrows 17 . Additional fluid continues down bore 34 , and thus tool string 14 until it is ultimately expelled from tool string 14 into the wellbore. Upon being expelled into the wellbore, the fluid travels up wellbore annulus portion 19 carrying debris as indicated by arrows 21 . Upon encountering the hydraulic barrier created by fluid flowing out of ports 37 (arrows 17 ), the debris laden fluid flowing up through wellbore annulus portion 19 is restricted from flow further up wellbore annulus portion 18 , or above wellbore annulus portion 18 . As a result, the debris laden fluid is directed toward opening 43 of collection member 40 as indicated by arrow 23 .
[0014] It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. For example, the port(s) 37 can be disposed perpendicular to an axis of the downhole tool or they can be disposed at any other angle desired or necessary to create the hydraulic barrier within the wellbore annulus. Further, it is to be understood that the term “wellbore” as used herein includes open-hole, cased, or any other type of wellbores. In addition, the use of the term “well” is to be understood to have the same meaning as “wellbore.” Moreover, in all of the embodiments discussed herein, upward, toward the surface of the well (not shown), is toward the top of Figures, and downward or downhole (the direction going away from the surface of the well) is toward the bottom of the Figures. However, it is to be understood that the tools may have their positions rotated in either direction any number of degrees. Accordingly, the tools can be used in any number of orientations easily determinable and adaptable to persons of ordinary skill in the art. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
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A downhole tool for removing debris from a wellbore comprises a body having a bore, a collection member, and a means for creating a hydraulic barrier within a wellbore annulus. The hydraulic barrier within the wellbore annulus restricts upward movement of a debris laden fluid within the wellbore annulus causing the debris laden fluid to be directed toward the collection member. Thus, the hydraulic barrier facilitates removal of debris from the wellbore.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to downhole packers. More particularly, the present invention relates to a two-stage, retrievable, expandable packer for sealing an annulus within a wellbore.
2. Background of the Related Art
Downhole packers are typically used to seal an annular area formed between two coaxially disposed tubulars within a wellbore. A packer may seal, for example, an annulus formed between production tubing disposed within wellbore casing. Alternatively, some packers seal an annulus between the outside of a tubular and an unlined borehole. Routine uses of packers include the protection of casing from pressure, both well and stimulation pressures, and protection of the wellbore casing from corrosive fluids. Other common uses may include the isolation of formations or of leaks within wellbore casing, squeezed perforation, or multiple producing zones of a well, thereby preventing migration of fluid or pressure between zones. Packers may also be used to hold kill fluids or treating fluids in the casing annulus.
Packers typically are either permanently set in a wellbore or retrievable. Permanent packers are installed in the wellbore with mechanical compression setting tools, fluid pressure devices, inflatable charges, or with cement or other materials pumped into an inflatable seal element. Due to the difficulty of removing permanent packers, retrievable packers to permit the deployment and retrieval of the packer from a particular wellbore location. Retrievable packers have a means for setting and then deactivating a sealing element, thereby permitting the device to be pulled back out of the wellbore.
Conventional packers typically comprise a sealing element between upper and lower retaining rings or elements. The sealing element is compressed to radially expand the sealing element outwardly into contact with the well casing therearound, thereby sealing the annulus.
One problem associated with conventional packers arises when a relatively large annular area between two tubulars is to be sealed. Conventional packers, because they rely solely on compressive forces applied to the ends of the sealing member, are sometimes ineffective in sealing these larger areas. If the annular area to be sealed is relatively large, the sealing element must be extensively compressed to fill the annulus. Often times, the element buckles due to the compressive forces, thereby effecting an incomplete seal or a seal that is prone to premature failure. Therefore, there is a need for an expandable packer that can be more effectively used in sealing annular areas between tubulars.
SUMMARY OF THE INVENTION
A packer for sealing an annulus in a wellbore is provided wherein the sealing element is actuated in a two-stage process. In one aspect, the packer comprises a body having a sealing element, a shoulder disposed there-around, and a slideable member arranged on the body. The slideable member has a first surface disposable beneath the element to increase the inner diameter thereof and a second surface disposable against an end of the element to compress the element against the shoulder to increase the outer diameter thereof.
In another aspect, the invention comprises a packer for sealing an annulus in a wellbore, comprising an annular body having at least one port disposed in an outer surface thereof; a shoulder disposed about the body; a slideable member slideably disposed about the body; and a sealing element disposed about the body between the shoulder and the slideable member whereby the element is expandable upon movement of the slideable member towards the shoulder. The slideable member has a first surface disposable beneath the element to increase the inner diameter thereof and a second surface disposable against an end of the element to compress the element and increase the outer diameter thereof. The ratchet mechanism retains the element in the compressed position to seal an annular area between the body and the inner surface of the tubular.
In still another aspect, a method for actuating a packer in a wellbore is provided. The method comprises running a body into the wellbore, the body comprising a sealing element a shoulder, and a slideable member slideably disposed there-around, wherein the slideable member comprise a first surface and a second surface; forcing the first surface beneath the element to increase the inner diameter thereof; and forcing the second surface against an end of the element to increase the outer diameter thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a partial section view of a down hole packer.
FIG. 1A is an enlarged section view of a ratchet housing.
FIG. 2 is a partial section view of a downhole packer disposed in a wellbore during a first stage of activation.
FIG. 2A is an enlarged section view of a containment ring.
FIG. 3 is a partial section view of a downhole two-stage packer after the first stage of activation.
FIG. 3A an enlarged section view of a mating engagement between a cylinder and a lower piston.
FIG. 4 is a partial section view of a downhole two-stage packer at the beginning of a second stage of activation.
FIG. 4A is an enlarged section view of a first section of a lower gauge ring.
FIG. 5 is a partial section view of a downhole two-stage packer after a second stage of activation.
FIG. 6 is a partial section view of a downhole two-stage packer during the release and recovery of the packer.
FIG. 6A is an enlarged section view of an ratcheting piston assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a partial section view of a two-stage down hole packer 100 . The packer 100 includes a body 102 , a lower piston 200 , a sealing element 300 , a shoulder 400 , a ratcheting piston assembly 500 , and a running ring 600 , each disposed about an outer surface of the body 102 . FIG. 1A is an enlarged section view showing portions of the ratcheting piston assembly in greater detail. The ratcheting piston assembly 500 includes a ratchet housing 510 , a slip ratchet 530 , containment rings 540 , 541 , an upper piston 550 , a seal ring 570 , and a cylinder 580 .
For ease and clarity of description, the packer 100 will be further described in more detail as if disposed within a tubular 700 in a vertical position wherein the top of the packer is the left-hand corner of FIGS. 1-6. It is to be understood, however, that the packer 100 may be disposed in any orientation, whether vertical or horizontal. Furthermore, the packer 100 may be disposed in a borehole without a tubular casing there-around.
The body 102 is a tubular member having a longitudinal bore 103 there-through. The body 102 also includes a first port 105 that allows for fluid communication between the bore 103 and a first variable volume chamber 120 which is adjacent an upper surface of the lower piston 200 . The body 102 further includes a second port 107 that allows for fluid communication between the bore 103 and a second variable volume chamber 130 . The second chamber 130 will be described below in operation with the packer 100 .
The lower piston 200 is disposed about the body 102 with a first end adjacent the sealing element 300 . A plurality of shear pins 236 releasably retain the lower piston 200 in a first position relative to the body 102 . The lower piston 200 includes two annular grooves 231 , 232 disposed therein to house elastomeric seals or the like to form a fluid barrier between the first chamber 120 and fluid in the wellbore. Referring to FIG. 1A, the lower piston 200 includes a sloped surface 233 . Also included in the lower piston is a recessed groove 234 disposed in an inner surface thereof that is engageable with a lock ring 250 . The piston 200 further includes a tapered shoulder 240 which contacts a similarly tapered inner surface 585 of the cylinder 580 . The engagement of the shoulders 240 , 585 allows the lower piston 200 and the cylinder 580 to move together along body 102 .
As will be explained, the tapered surface 233 travels underneath an inner surface of the sealing element 300 . The tapered shoulder 240 engages the tapered shoulder 585 of the cylinder 580 , and the recessed groove 234 of the lower piston 200 engages the lock ring 250 . Thereafter, the lower piston 200 and the cylinder 580 move together along the body 102 as one unit. The lock ring 250 prevents movement of the lower piston 200 in an opposite direction.
The sealing element 300 is an annular member disposed about the body 102 between the lower piston 200 and the shoulder 400 . The sealing element 300 may have any number of configurations to effectively seal the annulus created between the body 102 and a tubular there-around. For example, the sealing element 300 may include grooves, ridges, indentations or protrusions designed to allow the sealing element 300 to conform to variations in the shape of the interior of the tubular. The sealing element 300 can be constructed of any expandable or otherwise malleable material which creates a set position and stabilizes the body 102 relative to the tubular and which a differential force between the bore 103 of the body 102 and the wellbore does not cause the sealing element 300 to relax or shrink over time due to tool movement or thermal fluctuations within the wellbore. For example, the sealing member 300 may be a metal, a plastic, an elastomer, or a combination thereof.
The shoulder 400 is an annular member disposed about a lower portion of the body 102 , and adjacent a lower portion of the sealing element 300 . In the preferred embodiment, the shoulder is a releasable shoulder and includes a first 402 and second section 404 . The first section 402 is offset from the second section 404 thereby forming a cavity 415 between an inner surface of the second section 404 and the outer surface of the body 102 . Referring to FIGS. 4 and 4A, the first section 402 of the shoulder 400 includes a plurality of shear pins 405 which releasably engage the shoulder 400 to the body 102 . The first section 402 further includes a recessed groove 410 disposed about an inner surface thereof. The recessed groove 410 houses a snap ring 420 disposed about the outer surface of the body 102 . The snap ring 420 is disposed about the body 102 within an annular groove (not shown) formed in the outer surface of the body 102 and extends within the recessed groove 410 . The snap ring 420 prevents the shoulder 400 from upward axial movement along the body which may be caused by contact between the packer 100 and the wellbore, as the packer 100 is run into the well.
Referring again to FIG. 1, the second section 404 of the shoulder 400 includes a substantially flat upper surface which abuts a lower surface of the sealing member 300 . The upper surface also includes a radial protrusion 407 which abuts the lower surface of the sealing element 300 . As the sealing element 300 moves radially outward from the body 102 , the radial protrusion 407 presses into the sealing element 300 thereby providing a seal between the sealing element 300 and the shoulder 400 .
The ratcheting piston assembly 500 includes the slip ratchet 530 and containment rings 540 , 541 disposed about an upper end of the body 102 . An inner surface of the slip ratchet 530 includes teeth or serrations 532 to contact the outer surface of the body 102 . An outer surface of the slip ratchet 530 may be tapered to form a wedged or coned surface to complement a similar inner surface of the ratchet housing 510 . The containment rings 540 , 541 are concentric rings disposed about the body 102 . An expandable member 542 is disposed about the body 102 between the two rings 540 , 541 . The expandable member 542 is a spring-like member which applies an axial force against the containment rings 540 , 541 . In particular, the expandable member 542 creates an axial force which drives the teeth 532 of the inner surface of the slip ratchet 530 into the outer surface of the body 102 thereby holding the ratcheting piston assembly 500 firmly against the body 102 .
The ratchet housing 510 is an annular member disposed about the slip ratchet 530 and containment rings 540 , 541 . The ratchet housing 510 includes a first 502 and second section 504 . The first section 502 is offset from the second section 504 , thereby forming a substantially flat shoulder 501 . The first section 502 is disposed radially between the body 102 and the upper end of the cylinder 580 . The second section 504 is disposed radially about the slip ratchet 530 and a lower section of the upper piston 550 . The shoulder 501 is adjacent to and contacts the upper surface of the cylinder 580 . The ratchet housing 510 further includes an annular groove disposed about an outer surface of the first section 502 to house an elastomeric seal or the like to form a fluid barrier between the ratchet housing 510 and the cylinder 580 .
Referring to FIG. 2, the upper piston 550 is an annular member disposed about the body 102 adjacent the ratchet housing 510 . The upper piston 550 includes a first 552 and second section 554 . The first section 552 is offset from the second section 554 thereby forming a substantially flat shoulder 556 . The first section 552 is disposed radially between the body 102 and the second section 504 of the ratchet housing 510 . The second section 554 is disposed radially about the seal ring 570 . The shoulder 556 is adjacent to and contacts an upper surface of the second section 504 of the ratchet housing 510 . The upper piston 550 further includes an annular groove disposed about an outer surface of the first section 552 to house an elastomeric seal or the like to form a fluid barrier between the upper piston 550 and the ratchet housing 510 . The second port 107 is disposed within the outer surface of the body 102 adjacent the offset interface between the first 552 and second 554 sections of the upper piston 550 .
Referring again to FIG. 1, the cylinder 580 is disposed about the lower piston 200 between the ratchet housing 510 and the sealing element 300 . An upper surface of the cylinder 580 abuts the shoulder 501 of the ratchet housing 510 . The first chamber 120 is formed by an inner surface of the cylinder 580 and an outer surface of the body 102 . The lower piston 200 lies within a portion of the chamber 120 . The chamber 120 is in fluid communication with the bore 103 via the port 105 formed in the outer surface of the body 102 . Both the cylinder 580 and the lower piston 200 are longitudinally movable along the body 102 .
The cylinder 580 also includes a recessed groove 589 formed in an inner surface thereof. The recessed groove 589 houses the lock ring 250 . As stated above, the recessed groove 234 within the lower piston 200 is engageable with the lock ring 250 which extends radially from an inner surface of the cylinder 580 . After the lower piston 200 moves axially along the outer surface of the body 102 to a predetermined position, the lock ring 250 snaps into place within the recessed groove 234 of the lower piston 200 . Afterwards, the cylinder 580 and the lower piston 200 move along the housing together.
The cylinder 580 further includes a lower end having an axial protrusion or extension 581 which abuts an upper end of the sealing element 300 . As the sealing element 300 moves radially outward from the body 102 , the extension 581 presses into the sealing element 300 thereby providing a seal between the sealing element 300 and the cylinder 580 . Referring to FIG. 6, the cylinder 580 also includes a recessed groove or indentation 583 formed in an inner surface thereof toward a second end of the cylinder 580 . The indentation 583 engages a ridge or radial protrusion 505 extending from an outer surface of the ratchet housing. The radial protrusion 505 rests within the indentation 583 , engaging the ratchet housing 510 to the cylinder 580 .
Referring to FIGS. 2 and 2A, the running ring 600 is disposed about a split ring 610 at an upper end of the body 102 . For assembly purposes, the running ring 600 and the slip ring 610 are separate pieces. The running ring 600 and the split ring 610 prevent upward axial forces from moving the slideable components described herein once the packer 100 has been actuated within the wellbore. The split ring 610 is disposed about an annular groove disposed within the outer surface of the body 102 . The running ring 600 and the split ring 610 are releasably engaged to each other and the body 102 by a plurality of shear pins 620 . A stop ring 543 is also disposed about the body 102 within the first chamber 120 . The stop ring 543 prevents the ratcheting piston assembly 500 from over-travelling along the body 102 upon the operation and release of the packer 100 . The operation of the packer 100 and the interaction of the various components described above will be described in detail below.
FIG. 2 is a partial section view of a downhole packer 100 disposed in a wellbore during a first stage of activation. The packer 100 is first attached within a string of tubulars (not shown) and run down a wellbore 700 to a desired location. A fluid pressure is then supplied through the ports 105 , 107 , and to the first and second chambers 120 , 130 . The fluid pressure within the chambers 120 , 130 is substantially equal to the pressure within the bore 103 .
Referring to FIGS. 1-2, once the fluid pressure reaches a predetermined value which exceeds the sum of the wellbore pressure and the shear strength of the pins, the pins 236 shear allowing the lower piston 200 to move axially along the body 102 from a first position to a second position before any other components of the packer 100 are set in motion. In this manner, the lower piston moves to a position underneath the inner surface of the sealing element 300 as shown in FIG. 3 .
FIG. 3 is a partial section view of the packer of FIG. 2 after the first stage of activation. As shown in FIGS. 3 and 3A, the lower piston 200 has traveled underneath the element 300 to its second position thereby moving the element 300 closer to the inner surface of the tubular 710 there-around. As the lower piston 200 reaches the second position, the lock ring 250 snaps into the annular groove 234 . Thereafter, the lower piston 200 and the cylinder 580 move along the body 102 as one unit.
FIG. 4 is a partial section view of the packer of FIG. 2 at the beginning of a second stage of activation. During the second stage of activation, the fluid pressure through second port 107 acting upon a piston surface formed on upper piston 550 reaches a predetermined value which sets the upper piston 550 in motion. Movement of the upper piston 550 away from the seal ring 570 enlarges the volume of the second chamber 130 which is illustrated in FIG. 4 .
The ratchet housing 510 , slip ratchet 530 , cylinder 580 and lower piston 200 move along the body 102 with the upper piston 550 . The slip ratchet 530 with teeth 532 on an inner surface thereof prevent the ratcheting piston assembly 500 from travelling back towards its initial position. In the preferred embodiment, the teeth 532 are angled opposite the direction of travel to grip the outer surface of the body to prevent axial movement. The expandable member 542 disposed between the containment rings 540 , 541 acts to provide a spring-like axial force directly to the upper surface of the slip ratchet 530 thereby driving the teeth toward the surface of the body 102 . FIG. 6, described below, shows an expanded view of the containment rings 540 , 541 and the slip ratchet 530 .
As the components 200 , 510 , 530 , and 580 , travel along the body 102 , the lower surface of the cylinder 580 transfers force against the upper surface of the sealing element 300 . Because the lower surface of the sealing element is held by the shoulder 400 , element 300 is compressed by the opposing forces and caused to expand radially as shown in FIG. 5 .
FIG. 5 is a partial section view of the packer of FIG. 2 after the second stage of activation. As shown, the sealing element 300 has been longitudinally compressed and fully expanded in the radial direction thereby effectively sealing the annulus there-around. The second chamber 130 has further increased in volume. Further, as mentioned above, the axial protrusion 581 disposed on the lower surface of the cylinder 580 and the similar axial protrusion 407 disposed on the upper surface of the shoulder 400 provide a fluid seal with the sealing member 300 . Consequently, the sealing element 300 provides a fluid-tight seal within the annulus.
In one aspect, the packer 100 is removable from a wellbore. FIG. 6 is a partial section view of the packer during the release and recovery of the packer. To release the activated packer 100 , upward forces are applied which exceed the shear value of the pins 405 . An upward axial force may be supplied from the surface of the well. Once the pins 405 release, the shoulder 400 travels axially along the body 102 from a first position to a second position. The release of the shoulder 400 relaxes the sealing element 300 . The ratcheting assembly 500 is also released and free to move axially along the body 102 between the stop ring 543 and the seal ring 570 . The stop ring 543 prevents the upper ratcheting assembly 550 from over-travelling along the body 102 in the direction of the sealing element 300 , as shown in FIG. 6 A. The stop ring 543 also prevents the cylinder 580 from further contacting the sealing element 300 and re-activating the packer 100 .
While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope thereof is determined by the claims that follow.
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A two-stage packer and method for sealing an annulus in a wellbore is provided. The packer may be set by a force which will not cause a sealing element to buckle, collapse, or otherwise fail. In one aspect, the packer comprises a body having a sealing element and shoulder disposed there-around, and a slideable member slideably arranged on the body, the slideable member having a first surface disposable beneath the element to increase the inner diameter thereof and a second surface disposable against an end of the element to increase the outer diameter thereof. The method comprises running a body into the wellbore, the body comprising a sealing element and a slideable member slideably disposed there-around, wherein the slideable member comprises a first surface and a second surface; forcing the first surface beneath the element to increase the inner diameter thereof; and forcing the second surface against an end of the element to increase the outer diameter thereof.
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TECHNICAL FIELD
The present invention relates to a displacement measuring method for a motor, which is especially suitable for analyzing the magnetic field signals of the planar motor and enabling fine displacement detection of the planar motor.
BACKGROUND ART
The rotary motor may provide a driving power which can be converted to a planar movement by a mechanism. The mechanism is usually complex and the precision and speed of its transmission are limited for this, which is disadvantageous along with other problems such as frequent calibration, high cost, poor reliability and too big size. The early planar motor is operated by two planar type motors which are directly driven, which structure increases the complexity of the transmission system. In contrast, the planar motor, which can directly utilize electro-magnetic energy to drive the planar movement, has advantages of high concentration of force, low dissipation of heat and high precision etc, thus the inter-mediate transmitting device is saved which was used for converting a rotary movement into a planar movement and into another planar movement. And it becomes possible to integrate the object being controlled with the motor which has advantages such as quick response, good sensitivity, good servo control and simple structure.
Signal subdivision has a wide applicability in the fields of machinery and electronics. The magnetic field signals of the planar motor are distributed periodically, and when the signal varies in the one period, a fixed spatial displacement occurs correspondingly. Usually, the measurement circuit performs the measurement for the displacement by counting periods of the signal. When only counting the periods is performed, apparently, the resolution is the displacement corresponding to the one period of the signal. Thus, in order to improve the resolution of the instrument, subdivision must be required.
SUMMARY OF THE INVENTION
One goal of the present invention is to provide a method for measuring the displacement of the rotor of a planar motor, to measure relative displacements of the rotor and stator of the planar motor in X and Y directions and enable high subdivision of the signal and simple and quick signal processing.
To achieve the above-mentioned goal, the technical solution provided by the invention is as follows:
1) a magnetic field is generated by a magnetic steel array on the stator of a planar motor and four magnetic induction intensity sensors are disposed on the rotor of a planar motor, the coordinates of the first sensor are (X 1 , Y 1 ), the coordinates of the second sensor are (X 3 , Y 1 ), the coordinates of the third sensor are (X 2 , Y 2 ) and the coordinates of the fourth sensor are (X 4 , Y 2 ); the sampled signals of the first sensor, the second sensor, the third sensor and the fourth sensor are B a , B b , B c and B d , and the sampled signals B a , B b , B c and B d are processed in a signal processing circuit, wherein, the X-direction coordinates X 1 , X 2 , X 3 and X 4 are spaced apart from each other sequentially by a distance of one fourth of the X-direction magnetic field pitch τ x of the planar motor, and the Y-direction coordinates Y 1 and Y 2 are spaced apart from each other by a distance of one fourth of the Y-direction magnetic field pitch τ y of the planar motor;
2) supposing the X-direction displacement resolution as Δx, and the Y-direction displacement resolution as Δy, the magnitude of the magnetic induction intensity of the magnetic field generated by the magnetic steel array is measured as B M , the X-direction counting unit is initialized to be n x =0, the Y-direction counting unit is initialized to be n y =0, the X-direction magnetic field reference values are initialized to be
B ksx = B a 0 - B b 0 2 , B kcx = B co - B do 2 ,
and the Y-direction magnetic field reference values are initialized to be
B ksy = B a 0 + B b 0 2 , B kcy = B c 0 + B d 0 2 ,
wherein, B a0 , B b0 , B c0 and B d0 are respectively the sampled signals from the first sensor, the second sensor, the third sensor and the fourth sensor when the rotor of the planar motor is at the initial position;
3) the measurement starts, the sampled signals B a , B b , B c and B d of the first sensor, the second sensor, the third sensor and the fourth sensor are obtained by sampling, and the sampled signals B a , B b , B c and B d are processed in the signal processing circuit to obtain four signals B sx , B cx , B sy and B cy , wherein
B
sx
=
B
a
-
B
b
2
,
B
cx
=
B
c
-
B
d
2
,
B
sy
=
B
a
+
B
b
2
,
B
cy
=
B
c
+
B
d
2
;
4) it is determined by the signal processing circuit that whether the X-direction displacement is generated and whether the Y-direction displacement is generated,
a. if the X-direction displacement is generated, then whether the X-direction displacement is forward or backward is needed to be determined further, and if the generated X-direction displacement has a forward direction, then the X-direction counting unit performs n x =n x +1, and if the generated X-direction displacement has a backward direction, then the X-direction counting unit performs n x =n x −1, and the X-direction magnetic field reference values are updated to B ksx =B sx , B kcx =B cx ; thus the X-direction displacement measurement is completed;
if the X-direction displacement is not generated, then the X-direction displacement measurement is completed directly;
b. if the Y-direction displacement is generated, then whether the Y-direction displacement is forward or backward is needed to be determined further, and if the generated Y-direction displacement has a forward direction, then the Y-direction counting unit performs n y =n y +1, if the generated Y-direction displacement has a backward direction, then the Y-direction counting unit performs n y =n y −1, and the Y-direction magnetic field reference values are updated to B ksy =B sy , B kcy =B cy , and the Y-direction displacement measurement is completed;
if the Y-direction displacement is not generated, then the Y-direction displacement measurement is completed directly;
5) when the X-direction displacement measurement and the Y-direction displacement measurement are both completed, the X-direction relative displacement of the rotor of the planar motor is calculated as x=n x ·Δx, and the Y-direction relative displacement is calculated as y=n y ·Δy; and
6) the steps 3) to 5) are repeated to enable the real-time measurement for the displacement of the rotor of the planar motor.
In the above-mentioned technical solution, it is characterized in that, whether the X-direction displacement is generated and whether the X-direction displacement is forward or backward determined in the step 4) are performed as follows,
if
B ksx B cx - B kcx B sx B M 2 ≥ Δ x ,
then the relative displacement of the rotor of the planar motor in the X-direction is Δx; and if not, then it is considered that the relative displacement in the X-direction is not generated by the rotor of the planar motor;
if B ksx B cx −B kcx B sx ≧0, then the relative displacement of the rotor of the planar motor in the X-direction is in the forward direction; and if not, then the relative displacement of the rotor of the planar motor in the X-direction is in the backward direction.
In the above-mentioned technical solution, it is characterized in that, whether the Y-direction displacement is generated and whether the Y-direction displacement is forward or backward determined in the step 4) are performed as follows,
if
B ksy B cy - B kcy B sy B M 2 ≥ Δ y ,
then the relative displacement of the rotor of the planar motor in the Y-direction is Δy; and if not, then it is considered that the relative displacement in the Y-direction is not generated by the rotor of the planar motor;
if B ksy B cy −B kcy B sy ≧0, then the relative displacement of the rotor of the planar motor in the Y-direction is in the forward direction; and if not, then the relative displacement of the rotor of the planar motor in the Y-direction is in the backward direction.
The technical solution provided by the present invention is advantageous in various aspects, that is, the relative displacement of the rotor to the stator in the motor is measured by directly taking the magnetic field in the motor itself as a detection signal for the displacement. In this way, various disadvantages can be avoided such as difficulty in installing the sensors, and the resolution of the measuring system is improved to enable a high subdivision. And the calculations of transcendental functions and quadrant determination are avoided which is good for real-time high speed operation and has a higher engineering value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall structural schematic diagram showing the method for measuring the displacement of the rotor of a planar motor applied to a moving-coil type planar motor according to the present invention.
FIG. 2 is a schematic diagram showing the positions where a first sensor, a second sensor, a third sensor and a fourth sensor are installed on the rotor of a planar motor.
FIG. 3 is a flowchart showing the method for measuring the displacement of the rotor of a planar motor according to the present invention.
In which, 1 —stator of planar motor; 2 —magnetic steel array; 3 —rotor of planar motor; 4 —first sensor; 5 —second sensor; 6 —third sensor; 7 —fourth sensor; 8 —signal processing circuit.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the following, taking a moving-coil type planar motor as an example, the method for measuring the displacement of the rotor of the planar motor of the invention is illustrated in connection with the drawings and embodiments.
Referring to FIGS. 1 and 2 , a sensor arrangement is shown in which the method for measuring the displacement of the rotor is applied to a moving-coil type planar motor. A magnetic field B=B M (sin x+sin y) is generated by a magnetic steel array 2 on a stator 1 of a planar motor, wherein, B M is the magnitude of the magnetic induction intensity of the magnetic field B generated by the magnetic steel array 2 , x is the X-direction displacement of the rotor of the planar motor, and y is the Y-direction displacement of the rotor of the planar motor. Four magnetic induction intensity sensors are disposed on the rotor 3 of the planar motor, the coordinates of the first sensor 4 are (X 1 , Y 1 ), the coordinates of the second sensor 5 are (X 3 , Y 1 ), the coordinates of the third sensor 6 are (X 2 , Y 2 ) and the coordinates of the fourth sensor 7 are (X 4 , Y 2 ), the sampled signals of the first sensor, the second sensor, the third sensor and the fourth sensor are B a , B b , B c and B d respectively, and the sampled signals B a , B b , B c and B d are processed in a signal processing circuit 8 , wherein, the X-direction coordinates X 1 , X 2 , X 3 and X 4 are spaced apart from each other sequentially by a distance of one fourth of the X-direction magnetic field pitch τ x of the planar motor, and the Y-direction coordinates Y 1 and Y 2 are spaced apart from each other by a distance of one fourth of the Y-direction magnetic field pitch τ y of the planar motor.
FIG. 3 is a flowchart for measuring the displacement of the rotor of the planar motor according to the present invention. According to the above-mentioned sensor arrangement, the sampled signals B a , B b , B c and B d of the first sensor, the second sensor, the third sensor and the fourth sensor are respectively
B a =B M (sin x +sin y ) (1)
B b =B M (−sin x +sin y ) (2)
B c =B M (cos x +cos y ) (3)
B d =B M (−cos x +cos y ) (4)
The B a , B b , B c and B d are processed respectively to obtain four signals B sx , B cx , B sy and B cy , wherein
B
sx
=
B
a
-
B
b
2
,
B
cx
=
B
c
-
B
d
2
,
B
sy
=
B
a
+
B
b
2
,
B
cy
=
B
c
+
B
d
2
.
Suppose B sx , B cx , B sy and B cy at the time i as B isx , B icx , B isy and B icy respectively. According to the equations (1), (2), (3) and (4), and the definitions of B sx , B cx , B sy and B cy , B isx , B icx , B isy and B icy can be obtained as follows:
B isx =B M sin x (5)
B icx =B M cos x (6)
B isy =B M sin y (7)
B icy =B M cos y (8)
Suppose B sx , B cx , B sy and B cy at the time i+1 as B (i+1)sx , B (i+1)cx , B (i+1)sy and B (i+1)cy respectively. According to the equations (1), (2), (3) and (4), when the X-direction relative displacement Δ x of the rotor of the planar motor occurred from the time i to i+1 and the Y-direction relative displacement Δ y of the rotor of the planar motor occurred from the time i to i+1 are very small, then B (i+1)sx , B (i+1)cx , B (i+1)sy and B (i+1)cy are approximated as follows:
B (i+1)sx =B M sin( x+Δ x )≈ B M (sin x+Δ x cos x ) (9)
B (i+1)cx =B M cos( x+Δ x )≈ B M (cos x−Δ x sin x ) (10)
B (i+1)sy =B M sin( y+Δ y )≈ B M (sin y+Δ y cos y ) (11)
B (i+2)cy =B M cos( y+Δ y )≈ B M (cos y−Δ y sin y ) (12)
The equations (5) to (12) are calculated to obtain:
B
(
i
+
1
)
sx
B
icx
-
B
(
i
+
1
)
cx
B
isx
B
M
2
≈
Δ
x
(
13
)
B
(
i
+
1
)
sy
B
icy
-
B
(
i
+
1
)
cy
B
isy
B
M
2
≈
Δ
y
(
14
)
In the application of the real-time measurement for the displacement of the rotor of the planar motor, the left parts of the equations (13) and (14) are calculated from the sampled signals of the first sensor, the second sensor, the third sensor and the fourth sensor; and Δx and Δy are the X-direction displacement resolution and the Y-direction displacement resolution respectively which are set at initialization. During the real-time measurement, whether
B ( i + 1 ) sx B icx - B ( i + 1 ) cx B isx B M 2 ≥ Δ x
and whether
B ( i + 1 ) sy B icy - B ( i + 1 ) cy B isy B M 2 ≥ Δ y
are determined respectively and simultaneously. If
B ( i + 1 ) sx B icx - B ( i + 1 ) cx B isx B M 2 ≥ Δ x ,
then it is considered that the X-direction displacement generated by the rotor is Δx; if not, then it is considered that the X-direction displacement generated by the rotor is less than Δx. If
B ( i + 1 ) sy B icy - B ( i + 1 ) cy B isy B M 2 ≥ Δ y ,
then it is considered that the Y-direction displacement generated by the rotor is Δy; if not, then it is considered that the Y-direction displacement generated by the rotor is less than Δy.
If it is considered that the X-direction displacement is generated by the rotor, then the direction of displacement Δx is needed to be determined further; if B (i+1)sx B icx −B (i+1)cx B isx ≧0, then it is considered the direction of displacement Δx is the forward direction, and at the same time, the X-direction counting unit performs n x =n x +1; and if B (i+1)sx B icx −B (i+1)cx B isx <0, then it is considered that the direction of displacement Δx is the backward direction, and at the same time, the X-direction counting unit performs n x =n x −1.
If it is considered that the Y-direction displacement is generated by the rotor, then the direction of displacement Δy is needed to be determined further; if B (i+1)sy B icy −B (i+1)cy B isy ≧0, then it is considered that the direction of displacement Δy is the forward direction, and at the same time, the Y-direction counting unit performs n y =n y +1; and if B (i+1)sy B icy −B (i+1)cy B isy <0, then it is considered that the direction of displacement Δy is the backward direction, and at the same time, the Y-direction counting unit performs n y =n y −1.
When the X-direction displacement measurement and the Y-direction displacement measurement are both completed, the X-direction relative displacement of the rotor is calculated as x=n x ·Δx, and the Y-direction relative displacement is calculated as y=n y ·Δy.
Additionally, the present invention provides a method for measuring the displacement of the rotor of a planar motor, the method comprising the following steps,
1) a magnetic field is generated by a magnetic steel array 2 on a stator 1 of a planar motor and four magnetic induction intensity sensors are disposed on a rotor 3 of the planar motor, the coordinates of the first sensor 4 are (X 1 , Y 1 ), the coordinates of the second sensor 5 are (X 3 , Y 1 ), the coordinates of the third sensor 6 are (X 2 , Y 2 ) and the coordinates of the fourth sensor 7 are (X 4 , Y 2 ), the sampled signals of the first sensor, the second sensor, the third sensor and the fourth sensor are B a , B b , B c and B d respectively, and the sampled signals B a , B b , B c and B d are processed in a signal processing circuit 8 , wherein, the X-direction coordinates X 1 , X 2 , X 3 and X 4 are spaced apart from each other sequentially by a distance of one fourth of the X-direction magnetic field pitch τ x of the planar motor and the Y-direction coordinates Y 1 and Y 2 are spaced apart from each other by a distance of one fourth of the Y-direction magnetic field pitch τ y of the planar motor;
2) supposing the X-direction displacement resolution as Δx, and the Y-direction displacement resolution as Δy, the magnitude of the magnetic induction intensity of the magnetic field generated by the magnetic steel array 2 is measured as B M , the X-direction counting unit is initialized to be n x =0, the Y-direction counting unit is initialized to be n y =0, the X-direction magnetic field reference values are initialized to be
B ksx = B a 0 - B b 0 2 , B kcx = B co - B do 2 ,
and the Y-direction magnetic field reference values are initialized to be
B ksy = B a 0 + B b 0 2 , B kcy = B c 0 + B d 0 2 ,
wherein, B a0 , B b0 , B c0 and B d0 are respectively the sampled signals from the first sensor, the second sensor, the third sensor and the fourth sensor when the rotor of the planar motor is at the initial position;
3) the measurement starts, the sampled signals B a , B b , B c and B d of the first sensor 4 , the second sensor 5 , the third sensor 6 and the fourth sensor 7 are obtained by sampling, and the sampled signals B a , B b , B c and B d are processed in the signal processing circuit 8 to obtain four signals B sx , B cx , B sy and B cy , wherein
B
sx
=
B
a
-
B
b
2
,
B
cx
=
B
c
-
B
d
2
,
B
sy
=
B
a
+
B
b
2
,
B
cy
=
B
c
+
B
d
2
;
4) it is determined by the signal processing circuit 8 whether the X-direction displacement is generated and whether the Y-direction displacement is generated,
a. if the X-direction displacement is generated, then whether the X-direction displacement is forward or backward is needed to be determined further; and if the generated X-direction displacement has a forward direction, then the X-direction counting unit performs n x =n x +1; if the generated X-direction displacement has a backward direction, then the X-direction counting unit performs n x =n x −1, and the X-direction magnetic field reference values are updated to B ksx =B sx , B kcx =B cx ; thus the X-direction displacement measurement is completed;
if the X-direction displacement is not generated, then the X-direction displacement measurement is completed directly;
b. if the Y-direction displacement is generated, then whether the Y-direction displacement is forward or backward is needed to be determined further, and if the generated Y-direction displacement has a forward direction, then the Y-direction counting unit performs n y =n y +1, if the generated Y-direction displacement has a backward direction, then the Y-direction counting unit performs n y =n y −1, and the Y-direction magnetic field reference values are updated to B ksy =B sy , B kcy =B cy ; thus the Y-direction displacement measurement is completed;
if the Y-direction displacement is not generated, then the Y-direction displacement measurement is completed directly;
5) when the X-direction displacement measurement and the Y-direction displacement measurement are both completed, the X-direction relative displacement of the rotor is calculated as x=n x ·Δx, and the Y-direction relative displacement is calculated as y=n y ·Δy; and
6) the steps 3) to 5) are repeated to enable the real-time measurement for the displacement of the rotor of the planar motor.
In the above-mentioned technical solution, it is characterized in that, whether the X-direction displacement is generated and whether the X-direction displacement is forward or backward determined in the step 4) are performed as follows,
if
B ksx B cx - B kcx B sx B M 2 ≥ Δ x ,
then the relative displacement of the rotor in the X-direction is Δx; and if not, then it is considered that the relative displacement in the X-direction is not generated by the rotor;
if B ksx B cx −B kcx B sx ≧0, then the relative displacement of the rotor in the X-direction is in the forward direction; and if not, then the relative displacement of the rotor in the X-direction is in the backward direction.
In the above-mentioned technical solution, it is characterized in that, whether the Y-direction displacement is generated and whether the Y-direction displacement is forward or backward determined in the step 4) are performed as follows,
if
B ksy B cy - B kcy B sy B M 2 ≥ Δ y ,
then the relative displacement of the rotor in the Y-direction is Δy; and if not, then it is considered that the relative displacement in the Y-direction is not generated by the rotor;
if B ksy B cy −B kcy B sy ≧0, then the relative displacement of the rotor in the Y-direction is in the forward direction; and if not, then the relative displacement of the rotor in the Y-direction is in the backward direction.
Embodiment
The said magnetic field pitch τ x =τ y =35.35 mm, the said X-direction displacement resolution Δx=15 μm, the said Y-direction displacement resolution Δy=15 μm, and the magnitude of the magnetic induction intensity of the magnetic field generated by the magnetic steel array is measured as B M =80 mT.
1) a magnetic field is generated by a magnetic steel array 2 on the stator 1 of a planar motor and four magnetic induction intensity sensors are disposed on the rotor 3 of the planar motor; the coordinates of the first sensor 4 are (X 1 , Y 1 ), the coordinates of the second sensor 5 are (X 3 , Y 1 ), the coordinates of the third sensor 6 are (X 2 , Y 2 ) and the coordinates of the fourth sensor 7 are (X 4 , Y 2 ), the sampled signals of the first sensor, the second sensor, the third sensor and the fourth sensor are B a , B b , B c and B d , respectively, and the sampled signals B a , B b , B c and B d are processed in a signal processing circuit 8 , wherein, the X-direction coordinates X 1 , X 2 , X 3 and X 4 are spaced apart from each other sequentially by a distance of 8.8375 mm, and the Y-direction coordinates Y 1 and Y 2 are spaced apart from each other by a distance of 8.8375 mm;
2) supposing the X-direction displacement resolution as Δx=15 μm, the Y-direction displacement resolution as Δy=15 μm, the magnitude of the magnetic induction intensity of the magnetic field generated by the magnetic steel array 2 is measured as B M =80 mT, the X-direction counting unit is initialized to be n x =0, the Y-direction counting unit is initialized to be n y =0, the X-direction magnetic field reference values are initialized to be
B ksx = B a 0 - B b 0 2 , B kcx = B co - B do 2 ,
and the Y-direction magnetic field reference values are initialized to be
B ksy = B a 0 + B b 0 2 , B kcy = B c 0 + B d 0 2 ,
wherein, B a0 , B b0 , B c0 and B d0 are respectively the sampled signals from the first sensor, the second sensor, the third sensor and the fourth sensor when the rotor of the planar motor is at the initial position;
3) the measurement starts, the sampled signals B a , B b , B c and B d of the first sensor 4 , the second sensor 5 , the third sensor 6 and the fourth sensor 7 are obtained by sampling, and the sampled signals B a , B b , B c and B d are processed in the signal processing circuit 8 to obtain four signals B sx , B cx , B sy and B cy , wherein
B
sx
=
B
a
-
B
b
2
,
B
cx
=
B
c
-
B
d
2
,
B
sy
=
B
a
+
B
b
2
,
B
cy
=
B
c
+
B
d
2
;
4) it is determined by the signal processing circuit 8 whether the X-direction displacement is generated and whether the Y-direction displacement is generated,
a. if
B ksx B cx - B kcx B sx 6400 ≥ 15 ,
then the relative displacement of the planar motor in the X-direction is 15 μm, and whether the X-direction displacement is forward or backward is determined further, if B ksx B cx −B kcx B sx ≧0, then the X-direction displacement is in the forward direction, and the X-direction counting unit performs n x =n x +1, and if B ksx B cx −B kcx B sx <0, then the X-direction displacement is in the backward direction, and the X-direction counting unit performs n x =n x −1, and the X-direction magnetic field reference values are updated to B ksx =B sx , B kcx =B cx ; thus the X-direction displacement measurement is completed;
if
B ksx B cx - B kcx B sx 6400 < 15 ,
then the X-direction displacement measurement is completed directly;
b. if
B ksy B cy - B kcy B sy 6400 ≥ 15 ,
then the relative displacement of the planar motor in the Y-direction is 15 μm, and whether the Y-direction displacement is forward or backward is determined further, if B ksy B cy −B kcy B sy ≧0, then the Y-direction displacement is in the forward direction, and the Y-direction counting unit performs n y =n y +1, and if B ksy B cy −B kcy B sy <0, then the Y-direction displacement is in the backward direction, and the Y-direction counting unit performs n y =n y −1, and the Y-direction magnetic field reference values are updated to B ksy =B sy , B kcy =B cy ; thus the Y-direction displacement measurement is completed;
if
B ksy B cy - B kcy B sy 6400 ≥ 15 < 15 ,
then the Y-direction displacement measurement is completed directly;
5) when the X-direction displacement measurement and the Y-direction displacement measurement are both completed, the X-direction relative displacement of the rotor is calculated as x=15*n x , and the Y-direction relative displacement is calculated as y=15*n y ; and
6) the steps 3) to 5) are repeated to enable the real-time measurement for the displacement of the rotor of the planar motor.
Through the above-mentioned steps, a method for measuring the displacement of the rotor of the planar motor is provided, the relative displacements of the rotor and the stator in the X-direction and the Y-direction are measured respectively, enabling high subdivision to signals and simple and fast processing for signals.
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A method for measuring the displacement of a planar motor rotor. The measuring method comprises: four magnetic induction intensity sensors are distributed on the planar motor rotor; sampled signals of the four distributed sensors are processed to obtain signals B sx , B cx , B sy and B cy and magnetic field reference values B ksx , B kcx , B ksy and B kcy ; and X-direction displacement and Y-direction displacement can be measured respectively according to inequalities (I) and (II) by judgments, wherein Δ x and Δ y are X-direction displacement resolution and Y-direction displacement resolution respectively, and BM is the magnetic induction intensity amplitude of the magnetic field of said planar motor. The method provided by the invention is simple in calculation, can avoid calculation of a transcendental function and solve the quadrant judgment problem, is favorable to real-time high-speed operation and has a high engineering value.
B
ksx
B
cx
-
B
kcx
B
sx
B
M
2
≥
Δ
x
(
I
)
B
ksy
B
cy
-
B
kcy
B
sy
B
M
2
≥
Δ
y
(
II
)
| 6
|
CROSS REFERENCES TO RELATED APPLICATIONS
The subject application is closely related to applications now U.S. Pat. Nos. 5,058,411, filed Oct. 22, 1991; and 5,074,923, filed Dec. 24, 1991. The patents are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates generally to composite annular structures formed with a metal matrix and with a filament reinforcement. More particularly, it relates to annular structures having a titanium base matrix and reinforced by filaments of silicon carbide and to the HIPing of such structures to enhance the composite character thereof.
The preparation of titanium alloy base foils, sheets, and similar articles and of reinforced structures in which silicon carbide fibers are embedded in a titanium base alloy are described in U.S. Pat. Nos. 4,775,547; 4,782,884; 4,786,566; 4,805,294; 4,805,833; and 4,838,337 assigned to the same assignee as the subject application. The texts of these patents are incorporated herein by reference. Preparation of composites as described in these patents is the subject of intense study inasmuch as the composites have very high strength properties in relation to their weight. One of the properties which is particularly desirable is the high tensile properties imparted to the structures by the high tensile properties of the silicon carbide fibers or filaments. The tensile properties of the structures is related to the rule of mixtures. According to this rule, the proportion of the property, such as tensile property, which is attributed to the filament, as contrasted with the matrix, is determined by the volume percent of the filament present in the structure and by the tensile strength of the filament itself. Similarly the proportion of the same tensile property which is attributed to the matrix is determined by the volume percent of the matrix present in the structure and the tensile strength of the matrix itself.
Prior to the development of the processes described in the above-referenced patents, such structures were prepared by sandwiching the reinforcing filaments between foils of titanium base alloy and pressing the stacks of alternate layers of alloy and reinforcing filament until a composite structure was formed. However, that prior art practice was found to be less than satisfactory when attempts were made to form ring structures in which the filament was an internal reinforcement for the entire ring.
The structures taught in the above-referenced patents and the methods by which they are formed, greatly improved over the earlier practice of forming sandwiches of matrix and reinforcing filament by compression.
Later it was found that while the structures prepared as described in the above-referenced patents have properties which are a great improvement over earlier structures, the attainment of the potentially very high ultimate tensile strength of these structures did not measure up to the values theoretically possible. The testing of composites formed according to the methods taught in the above patents has demonstrated that although modulus values are generally in good agreement with the rule of mixtures predictions, the ultimate tensile strength is usually much lower than predicted by the underlying properties of the individual ingredients to the composite. A number of applications have been filed which are directed toward the overcoming the problem of lower than expected tensile properties. These include an application Ser. No. 07/445,203, filed Dec. 4, 1989 now U.S. Pat. No. 5,201,939 and U.S. Pat. Nos. 4,978,585, issued Dec. 18, 1990; 5,017,438, issued May 21, 1991; and 5,045,407, issued Sep. 3, 1991. The texts of these applications are incorporated herein by reference.
One of the structures which has been found to be particularly desirable in the use of the technology of these reference patents is an annular article having a metal matrix and having silicon carbide filament reinforcement extending many times around the entire ring. Rings of a few inches to a few feet in diameter are prepared with such reinforcing filaments. Such ring structures have very high tensile properties relative to their weight, particularly when compared to structures made entirely of metal.
The fiber reinforced ring can be used, for example, as a reinforcement ring structure for compressor disks of a jet engine. In order to serve to reinforce the disk in a compressor stage of a jet engine a large number of layers of reinforcement are required. It has been found that it is very difficult to continue to add more and more layers of filament reinforcement to a ring structure because of differences in thermal expansion coefficient and other factors.
One of the problems which results from the continued addition of outer layers of filament reinforced matrix to a ring structure is that the outer rings tend to cause a compression and buckling of the outer filaments as conventional consolidation occurs during HIPing. Such buckling of the filaments can cause damage to the filaments and accordingly to the rings of which the filaments are a part. Such buckling tends to occur as the number of fiber layers is increased so that when the number reaches 20 or 30 successive layers, any additional layers which are added beyond such value can result in buckling and damage to the filaments, as the overall structure is consolidated through the HIPing operation.
One way in which this problem has been solved is by forming a series of concentric rings which are then assembled together to provide a reinforced ring structure having more than 100 layers of reinforcement. Such ring structures may be of quite large diameter of the order of a foot or several feet and must nevertheless be nested together within very close tolerances of only a few thousands of an inch.
BRIEF STATEMENT OF THE INVENTION
In one of its broader aspects, the objects of the present invention can be achieved by first providing an unconsolidated multilayer filament reinforced ring structure.
The ring structure has a silicon carbide filamentary reinforcement embedded within a plasma deposited metal matrix. The ring is sealed within a HIPing can to have an annular shape conforming generally to that of the ring structure to be HIPed. The outer wall of the HIPing can be made to be substantially stronger than the inner and side walls of the can. The can and its contents are HIPed and the action of the HIPing on the contained ring is asymmetrical in that the inner and side walls undergo more movement as a result of the HIPing than does the outer wall. As a result, the ring structure is preferentially hipped from the inner and side surfaces and is thus asymmetrically HIPed. This asymmetrical HIPing causes the ring structure to be consolidated preferentially from the inside and avoids the buckling of and damage to the reinforcing filaments of the outer portions of the ring.
BRIEF DESCRIPTION OF THE DRAWINGS
The description which follows will be understood with greater clarity if reference is made to the accompanying drawings in which:
FIG. 1 is a radial section of a reinforced ring structure in an asymmetric HIPing can; and
FIG. 2 is an axial section taken through one half of the ring structure and can of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
A low pressure r.f. plasma-spray process is used for the fabrication of multi-layer titanium base alloy ring elements where the titanium base alloy serves as a matrix in a composite structure containing reinforcing filaments. The low pressure r.f. plasma spray process may be that disclosed in the above patents or it may be that disclosed in copending application Ser. No. 07/524,527, filed May 17, 1990, now U.S. Pat. No. 5,120,567, the text of which is incorporated herein by reference.
The silicon carbide filaments are the principal filaments of concern for these reinforced composite structures. However, other reinforcing filaments including ceramic filaments such as single crystal Al 2 O 3 filaments may be used as well.
The titanium base alloy can be a conventional titanium alloy, such as Ti-64, Ti-6242, or Ti-1421 or it can be a titanium aluminide. Such aluminide may be a gamma aluminide containing 48 atomic % titanium, 48 atomic % aluminum, 2 atomic % of niobium and 2 atomic % of chromium, for example. Titanium alloy Ti-64 has a composition of Ti-6Al-4V, by weight. Titanium alloy 6242 has composition Ti-6Al-2Sn-4Zr-2Mo, by weight. Titanium alloy 1421 has a composition Ti-14Al-21Nb by weight.
The composite ring elements, which may be from a few inches to a few feet in diameter, are fabricated by plasma-spraying of a 1/8 inch thick layer of the matrix alloy onto a cylinder of mild steel. The steel mandril is removed from the matrix alloy layer by chemical dissolution in a nitric acid solution or by thermal debonding using the thermal expansion difference between the titanium alloy matrix and the mild steel. The "as-sprayed" titanium alloy matrix ring is then wound with a continuous SiC filament as described in the patents referenced in the background statement above. The filament wound cylinder is then oversprayed with additional titanium base matrix alloy to completely cover the filament. The winding and spraying steps are repeated until the desired number of plies is obtained on the composite ring element.
Since the low pressure RF plasma-spray process yields an as-sprayed density less than theoretical, it is necessary to HIP densify the composite ring. The term HIP signifies heating and isostatic pressing which is a well-known conventional processing step. The dimensional change of the ring during HIPing can lead to fiber buckling in the outermost layers of the composite ring. Such buckling can break fibers and reduce the strength of the composite ring. Using this practice, there is a practical limit of 20 to 30 layers which can be deposited at one time before it becomes necessary to densify the ring. Such densification of a structure having 20 or 30 initial layers seeks to avoid the buckling and damage to the rings which is occasioned by the HIPing of a composite structure having more than 20 or 30 layers to be densified at one time.
However, the composite structure to be formed is one having as many as 150 layers. A structure with about 150 layers of composite is a novel structure which is deemed suitable for use, for example, as reinforcing rings in aircraft engine compressor structures. One way of achieving this number of layers is by "nesting" multiple composite ring elements which are separately fabricated. Following the separate fabrication such composite ring elements are "nested" together to form a ring assembly which can be HIP bonded to form a composite ring with the desired number of plies.
We have discovered that it is possible to HIP a reinforced multilayer ring structure having many layers of reinforcement of silicon carbide filament. For example, we can obtain a structure which has a lower level of buckling of the outer reinforcing filaments, or no such buckling or damage to such outer filaments, through a novel process which we have devised. Our novel process is described now with reference the accompanying drawings.
Referring now first to FIG. 1, FIG. 1 is a radial section of a ring structure in which a filament reinforcement, such as silicon carbide, is embedded in a plasma spray deposited titanium base alloy matrix. The ring structure 12 is made up of reinforcing filament 14 and embedding matrix 16. The reinforcement 14 is not illustrated fully around the ring or in the number of layers actually present in the ring for clarity of illustration and reference. In a sample, such as illustrated in FIG. 1, the number of reinforcing layers of filament would exceed 20 and may very well exceed 30 individual layers. Such layers are, as indicated above, formed by winding a single filament around the entire circumference of the ring structure prior to the plasma spray depositing of the next layer of titanium base alloy. The ring structure 12 is enclosed within a HIPing can for purposes of consolidation to full density. The can includes an inner thinner layer 18 of a canning metal such as a mild steel and an outer thicker layer 20 of such a mild steel canning material.
The section taken along the axis of the ring structure is illustrated in FIG. 2. In this figure the outer thicker section 20 encloses the outermost surface of the fiber reinforced ring structure 12 while thinner canning elements 18, 22 and 24 form the other three enclosing surfaces of an essentially annular canning element 10.
In the sectional view of FIG. 2, the rows of reinforcing elements, shown as dots in the figure, are illustrated in a smaller number than actually exists in the structure. This smaller number of the reinforcing filaments are illustrated in this fashion for clarity of illustration of representation. Enclosing HIPing can 10 is welded in place on the ring structure 12 so as to provide a closely fitting annular housing for the ring structure. It is then evacuated through a conventional vacuum port, which is not shown in the figures. Following the evacuation, the ring structure and its enclosing can are HIPed within a HIPing environment at elevated temperature and pressure for a suitably long time. HIPing may be carried out, for example, at 1000° C., 15 ksi for one or two or more hours.
HIPing of the structure, as illustrated in FIGS. 1 and 2, produces some novel effects in the ring structure 12 and these novel effects are now described.
One such novel effect is that the HIPing of the ring structure is asymmetrical. By this is meant that the pressure of a HIP operation is potentially isostatic. The phrase "HIP" itself means heating and isostatic pressing. A HIPing occurs where a structure is placed in a HIPing environment because the environment is at elevated pressure and acts with the same pressure on all surfaces of the article to be HIPed. However, the applicants have modified the practice in carrying out the present invention. Pursuant to the present invention, the can which is employed to house the article to be HIPed is not formed of uniform wall thickness or wall strength. Rather, the wall thickness or strength of the exterior wall 20 is greater than that of the interior wall 18 and also of the lateral walls 22 and 24. Because the outer wall has a greater thickness or strength, it resists the compression of the HIPing atmosphere and the result is that the HIPing action acts with greater force and effect on the interior wall 18 as well as on the lateral walls 22 and 24. As a consequence of the uneven application of pressure, greater compaction of the ring structure 12 occurs at the interior and at the sides of the structure than occurs at the outer surface of the ring structure. This constitutes an asymmetric compaction or asymmetric consolidation of the ring structure itself. Because this compaction is outwardly asymmetric, there is a reduced tendency to cause buckling of and damage to the outer reinforcing filaments of the ring structure 12. The consolidation accordingly is accomplished by compressing from the sides and the internal surface of the ring to move the consolidated material toward the center of the body of the ring and outward from the center of the ring.
Because there is less compaction of the outer surface of the ring, it is possible to include a larger number of layers of reinforcing fibers in the ring structure to be consolidated. Thus if the ring structure suffers buckling and damage of the outer fibers when carrying out a conventional HIPing practice when there are 30 layers of reinforcing filaments in a ring, such as 12. It can be found that the 30 layers are successfully consolidated using the practice of the present invention because the buckling of the outer layers of filament and the damage which results from such buckling is avoided. The consolidation of the ring is accomplished but the buckling is prevented.
The following example illustrates the method of the present invention.
EXAMPLE
A single, nominally four inch diameter, four inch wide, four ply composite ring was fabricated using a Ti-14Al-21Nb matrix alloy and layers of SCS-6 SiC filament. The rings were fabricated by initially spraying a layer about 1/8 inch thick of Ti-1421 matrix alloy onto a steel mandrel that had been coated with 0.005 inches of Al 2 O 3 . After cooling, the 1/8 inch thick Ti-1421 ring debonded from the steel mandrel at the steel-Al 2 O 3 interface.
A four ply composite ring was fabricated using the 1/8 inch thick Ti-1421 ring as mandrel. The composite ring was fabricated by alternately machining the "as-sprayed" surface smooth, machining a helical groove about 0.003" deep with a spacing of 112 grooves per inch, winding continuous SCS-6 SiC filament in the groove, and overspraying the wound ring with additional Ti-1421 material. The above process was repeated until four plies were provided on the ring. If the ring became "out-of-round" because of the repeated thermal cycles, the partially completed ring was restored to roundness by thermally sizing it on a solid 304L stainless steel mandrel at 950° C. for 15 minutes at temperature.
After plasma spray fabrication of the composite ring was completed, the composite four ply ring was cut into three rings of smaller widths.
Two of the narrower rings cut from the 4-inch wide ring were sealed in HIP cans which had been machined from mild steel. The HIP can design comprised an inner can ring, an outer can ring, and two end can rings which closely matched the dimensions of each composite ring. Provisions were made to evacuate the HIP cans prior to sealing. In one HIP can, the wall thickness of the inner can ring was the same as the wall thickness of the outer can ring (0.070"). For the second HIP can, the wall thickness of the outer can ring (0.210") was three times as thick as the wall thickness of the inner can ring (0.070"). The intent of the asymmetrical can design was to force the inside diameter of the ring to move outwards rather than have the outside diameter move inwards during the HIP densification.
The two HIP cans were HIP'd for 3 hours at 1000° C. at 15 ksi pressure. After HIPing, the cans were removed by chemical dissolution in an acid solution. Table I shows the inside and outside diameters of each ring pair before and after HIPing. It is evident from the Table that the inside diameter of the asymmetrical canned ring grew larger, but the symmetrically canned ring also decreased in diameter. In addition, the outside diameter of the asymmetrically canned composite ring decreased about 4 fold less than did the symmetrically canned composite ring. The data in the Table demonstrate that the desired densification effect was achieved using the asymmetric and the symmetric HIP cans.
TABLE______________________________________Nested Ring Dimensional Changes During HIPing______________________________________ ID Before ID After ID Difference (inches) (inches) (inches) % ChangeSym- 3.367 3.362 -0.005 -0.15metricAsym- 3.364 3.366 +0.002 +1.06metric OD Before OD After OD Difference (inches) (inches) (inches) % ChangeSym- 3.655 3.647 -0.008 -0.22metricAsym- 3.655 3.653 -0.002 -0.05metric______________________________________
In general, it has been found that for a filament reinforcement embedded within a plasma sprayed deposited matrix, it is preferable to have the filament reinforcement portion of the composite in tension and to have the matrix portion of the composite in compression. It should be noted that the result of consolidation employing the asymmetric method of the present invention results in a structure which does have the filament reinforcement of the composite in tension and the matrix of the composite in compression.
One of the things which is beneficial in practice Of the present invention for the asymmetric HIPing of ring shaped composite structures is that the structures are designed to operate in tension; that is their primary strength value is in developing a high tension as articles within the ring are urged outward. The reinforcing filament is wound in a circumferential fashion to enhance the tensile properties of the ring. In carrying out the asymmetric HIPing of the ring structure having a filament reinforcement, the effect is to move the inner portion of the ring structure outward and in doing so to reach the point at which the filament reinforcement resists the further outward movement of the material of the ring. In other words, the asymmetric HIPing of the ring structure takes advantage of the fact that a high tensile property resides within the reinforcing filament so that as the material is moved the material of the inner portion of the ring is moved outward during HIPing the reinforcement is placed under greater tension as this occurs and it is the greater tensile capability of the filament which is one of the most attractive properties of the filament reinforced ring structure. Accordingly, one of the features of the present invention is to provide a reinforced ring structure which optimizes through the asymmetric HIPing process, the enhancement of the application of the tensile property of the reinforcement. This contrasts entirely and distinctly with a prior practice of symmetric HIPing which has, as noted in the above specification, resulted in excessive compaction and as a result in damage to the outer filaments of the structure. It is deemed feasible because of this result of the asymmetric HIPing that rings having many more plies to the extent of 50 or 60 plies of reinforcement can be advantageously HIPped employing the practice of the present invention.
Also, pursuant to the present invention, it is possible to process rings which have greater concentrations of less dense material. For example, in the example given above, much of the less dense material is removed through the machining and grooving operations. However, because of the outward movement of material of the rings during the asymmetric HIPing, it is possible to HIP rings which have lower density initial matrices and to cause an outward movement of the matrix material to the point where the tensile properties of the reinforcing filaments take over and the outward movement is stopped by the tensile resistance of the filament reinforcement itself.
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A method for asymmetrically consolidating a ring structure having a filamentary reinforcement embedded in a plasma sprayed deposited matrix is taught. The method involves fabricating a filament reinforced plasma sprayed deposit matrix structure and asymmetrically consolidating the structure. The asymmetric consolidation is accomplished by placing a thicker and/or stronger can surface on the outer portions of the ring structure and a thinner and/or weaker can structure on the inner and side surfaces of the reinforced ring structure. The HIPing of the reinforced ring structure with the asymmetric can results in a preferential compaction of the ring from the inside toward the outside and avoids the buckling of and damage to the reinforcement filaments on the outer portions of the structure.
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The invention described herein may be manufactured and used by or for the government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a device and method for clearing obstructions in surf zones. More particularly, the device and method relates to clearing obstacles and mines by sundering the subsoil beneath and alongside the obstructions in a surf zone, thereby eliminating subsoil support from beneath the obstruction, and causing the obstruction either to drop away from the surface of the water or to float away. Most particularly, the device and method facilitate successful amphibious operations by clearing obstructions within the transit path of landing vehicles and/or naval support vessels.
2. Description of the Related Art
Military amphibious assault operations require the movement of large numbers of troops and massive amounts of supplies into a confined shore area, such as a beach, over a short period of time. Generally, these amphibious assaults are conducted in areas occupied by opposing military forces. In defending against an amphibious attack, the opposing military forces may place non-explosives obstacles, such as artificial barriers or reefs, concrete cubes, log posts, steel hedgehogs, steel tetrahedrons, sea urchins, wire and the like, within the surf zone of an expected line of assault to impede efficient movement of landing craft traveling to the shore. In using man-made non-explosive obstacles, defending forces attempt to delay the amphibious assault and/or channelize an assault into a defended area. Interrupts in the movement of troops and supplies across the surf zone to the shore may result in a significant disadvantage, including loss of personnel and equipment, to the assaulting forces.
Additionally, amphibious assault operations may necessarily cross surf zone areas having naturally occurring obstacles within a transit path of assault boats to the shore. The obstacles may be coral, rocks, or other large objects or protrusions in the water which are hazardous to speeding landing craft carrying heavy equipment and troops. These naturally occurring obstacles protrude into the path of advancing landing craft, impeding their transit, possibly disabling or sinking the landing crafts and/or support vessels.
Another hazard to an amphibious assault operation is deployed mines. The removal of mines is a particularly difficult endeavor. Mines are conventionally used to impede the progress of military forces through an area, either sea or land. Used against an amphibious assault within a surf zone, mines are particularly troublesome for the successful completion of the assault. Selective placement of mines within the surf zone may hinder or halt the transit of landing craft to shore.
All of these obstructions, man-made non-explosive obstacles, naturally occurring obstacles and/or mines may force advancing troops to by-pass the most expeditious transit route through a surf zone, causing delays, loss of surprise, and/or the loss of a concentrated advancing amphibious force. With the loss of force concentration, an advancing force may receive high rates of casualties and/or lose military advantage against the defending forces.
Several approaches to obstacle and mine clearance are known. U.S. Pat. No. 5,661,258 (Garcia et al.) discloses an air-delivered ordnance explosive for clearing navigable sea channels. U.S. Pat. No. 5,598,152 (Scarzello et al.) discloses an underwater vehicle that detects possible mine locations and deposits mine-clearing explosives close-by. U.S. Pat. No. 5,437,230 (Harris et al.) discloses a standoff mine neutralization system using an unpowered air vehicle. U.S. Statutory Invention Registration no. H162 (Sullivan, Jr. et al.) discloses a system for wide-area mine clearance using multiple fuel-containing containers.
However, these approaches are deficient when used for surf zone operations. First, amphibious assault operations require an unannounced assault in a given area. By limiting the amount of time the enemy knows of the assault, enemy forces are denied preparation time to reposition armaments and defense positions during the amphibious onslaught. Second, rapid execution of the amphibious operation is required to deny a defending force use of its reserve forces. Third, the successful destruction of an obstruction with conventional explosives depends partly on the composition of the obstruction. Fourth, destruction of obstructions requires the detonation of high yield explosives. These explosives are dangerous to handle and move, complicating their use in training and operational use. Additionally, the high yield explosives are environmentally hazardous, further complicating training for the safe use of the explosives. Fifth, a device and method which are useful against man-made and natural obstacles are needed, because the rapidly evolving military situation before and during an amphibious assault may not allow the amphibious forces time to identify the particular type of obstruction. Sixth, high yield explosives create significant crater or berms along the subsoil surface which create hazards for landing vehicles within the surf zone. Accordingly, none of the identified techniques provide for reliable clearance of man-made non-explosive obstacles, naturally occurring obstacles and mines in surf zones during amphibious assault operations.
In view of the foregoing, improvements in clearing obstructions in surf zone areas have been desired. In addition to improved reliability of clearing both obstacles and mines from landing craft transit paths, it has been desired to provide a device which is relatively safe to deploy.
The present invention addresses these needs.
SUMMARY OF THE INVENTION
The present invention provides a device for clearing obstructions from surf zones. The device comprises an elongated generally cylindrical housing having a first end and a second end, the housing encasing a fuse positioned inside of the first end and a compartment containing a gas generating compound positioned inside of the second end, the fuse ignitionally attached to the compound and being capable of causing the compound to initiate burn, the compound having a burn time which is capable of producing sufficient amounts of gas capable of rupturing the housing. The device of the present invention may be used for military or civilian applications. The device may be placed at the desired detonation location by a swimmer or remote means, or may launched to the desired detonation location by a rocket mechanism.
Additionally, a method for clearing obstructions from a surf zone comprising the steps of providing the previously described device, interring the device within subsoil proximate to the obstructions, and, detonating the compound wherein a burning of the compound forms sufficient amounts of gas to rupture the housing and sunder subsoil support of the obstructions effective to clear the obstructions is disclosed.
These and other features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following detailed description, reference will be made to the attached drawings in which:
FIG. 1 is a side cross-sectional view of a preferred projectile for the present invention.
FIG. 2 is a side cross-sectional view of another embodiment of the invention.
FIGS. 3A-3D show a schematic of the present invention lowering and clearing obstacles in a surf zone.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is a device and method for clearing obstructions from surf zones by sundering subsoil support from beneath and alongside the obstructions. By removing the supporting subsoil, the obstructions sink a sufficient depth for landing craft and vessels to transit over the obstructions to the shore or are otherwise cleared from the path of the landing craft and vessels.
The shore is any land mass adjacent to a body of water, such as beach, coast, cliffs, and the like, which is within an objective area of an amphibious assault. Within the adjacent water body, a surf zone exists having a subsoil bottom. Generally, surf zones exist between a combat amphibious force and a shore, or coast, where an amphibious attack is to occur. This is a distance of approximately three miles distance or less. More particularly, the surf zone is from about 5 meters to about 500 meters from the shore. The surf zone is considered that area which is too far from shore for a landing craft to disembark the troops and equipment on board, and close enough to the shore which allows objects within the water to impede the process of the landing craft and support vessels, which is generally at the line of surf formation along the shore. This generally occurs with a water depth of from about the high water mark to about a point of high tide mark, and may vary of from about 3 feet to about 20 feet. In this area, man-made and natural obstructions may impede the landing craft from reaching the shore, by grounding and/or sinking it. When grounded away from the shore, landing craft are useless to the advancing amphibious force and are at risk to enemy bombardment.
The subsoil may be any water bed material which is encountered by an amphibious assault force transiting to shore. This includes sand, coral, mud, light vegetation, other soft and semi-hard bottoms, and the like. Obstructions rest on top of or constitute part of the subsoil or may be buried therein.
Obstructions are any obstacles, man-made or naturally occurring, mines, protrusions, objects, and the like, which impede the movement of landing craft and support vessels through a surf zone area. Accordingly, obstructions must be of such shallow depth as to interfere with the transit of landing craft, vessels or support ships. In general, this includes depths which are of equal distance or less as the drafts of such vessels.
The obstructions are sunk by the present invention to a sufficient depth for landing craft and vessels to transit over the sunk obstruction and continue on to the shore. This includes obstructions such as artificial barriers or reefs, concrete cubes, steel hedgehogs, steel tetrahedrons, coral, rocks, sea urchins, wire and the like. Accordingly, the obstruction need only be sunk to a depth which is greater than the draft of the landing craft and/or support vessel that will transit in that surf zone area. The depth varies by the type of landing craft and support vessel used, but generally ranges from about 8 feet or less, more particularly from about 6 feet or less, most particularly 4 feet or less.
Additionally, by removing subsoil support form beneath an obstruction which has a specific gravity less than the surrounding water, the obstruction breaks away from the subsoil and floats away. This includes obstructions such as log posts and other timber objects, plastic materials, fabric materials and the like. The obstruction is freed from an "anchoring" subsoil support sufficient to allow free drifting. Current and surf conditions are factors which affect the amount of subsoil support removal in floating these obstructions.
In addition to military amphibious operations, the present invention is directed to civilian applications. Pier and seawall clearance, bridge piling removal and the like may be accomplished by the present invention. Generally, rocket delivery of the gas generating compound is not required or preferred. Accordingly, swimmers and remote means such as robots, mechanical arms and the like, are used to place the gas generating compound proximate to the obstructions. Preferably, the several devices are placed at specified intervals or stacked together reaching to the bottom of the obstruction. The swimmer and remote means may also be used in military operations to place the gas generating compound proximate to the obstructions, when combat conditions permit.
The present invention is considered to be located proximate to obstructions when that location provides for movement of the obstruction with the release of the gas. The location varies with the factors of subsoil type, depth, compound composition, charge design, obstruction composition, and the like, with these factors being known to those skilled in the art. More preferably, proximate locations are located beneath the obstructions, at approximately four feet depth in the subsoil, at a 1/2 distance between the edge of the obstruction and its center of gravity. Most preferably, proximate allows removal of the obstruction effective to permit amphibious assault operations over the obstruction area. However, multiple devices may be placed proximate to a single obstruction, with each device adding incrementally to the obstruction removal. Use of multiple devices allow a cascading sundering effect, and less explosive material within each device for a given obstruction.
As shown in FIG. 1, the device of the present invention comprises a generally cylindrical shape or projectile 10. The projectile 10 has a housing 12 made of any resilient material, such as metal, ceramic, other hard materials and the like, capable of withstanding firing or launch. The housing 12 has a frangible or rupturable portion 12a in one embodiment shown in FIG. 1 or a frangible or rupturable panel or wall 18, as shown in another embodiment in FIG. 2. The projectile 10 also has the capability of over-the-horizon firing or launching and the housing 12 must be sufficiently hard to withstand impact of the projectile 10 into the surf and to inter, or embed, into the subsoil without rupture from this distance, if needed. However, the distance may be any distance allowing accurate positioning of the projectile 10, preferably from about 50 miles or less, more preferably from about 20 miles or less, and most preferably from about 6 mile or less.
FIG. 1 also shows a fuse 13. The fuse 13 is shown in the forward section of the projectile 10 and must be capable of initiating a gas generating compound 14, which is a type of deflagration explosive. The fuse 13 may be of any construction as long as it is able to withstand projectile impact through the water and further down into the subsoil. The fuse 13 is timed to initiate burn once the projectile 10 is embedded in the subsoil. The fuse 13 is detonationally attached to the gas generating compound. The fuse 13 is located at the front of the warhead when a solid grain is used and at the rear of the warhead when a perforated grain gas generator compound 14 is used. A venturi 16 is used between the fuse 13 and the gas generating compound 14 to maintain the pressure in the section of the gas generator compound 14 above critical pressure level. Preferably, the fuse 13 is a time programmable delayed fuse. Fuse 13 ignition timing is dependent on the velocity of the impacting projectile 10 and the composition or type of subsoil in the surf zone area. Preferably, the time delay from subsoil impact to fuse 13 ignition is from about 0.1 seconds to about 10 seconds, more preferably from about 0.5 seconds to about 5 seconds, and most preferably from about 2 seconds to about 3 seconds. The fuses 13 have igniters. Preferably, the fuses 13 are modified M427 or M438, manufactured by General Dynamics of Burlington, Vt., replacing the explosive booster with an igniter.
The gas generating compound 14 shown in FIG. 1 is an explosive which produces excessive or large amounts of gas over a short period of time. Excessive or large amounts of gas are those amounts which are capable of effectively sundering an existing subsoil so as to create an increased depth or clearing of an obstruction thereon. Unlike high yield explosives which have burn rates of from about 5,000 to about 10,000 meters per second, gas generating compounds are slow burning. This slower release of gas increases the amount of released gas over the burn time of the explosive of from about 0.25 inches per second to about 4 inches per second, more preferably from about 0.5 inches per second to about 2 inches per seconds. Gas generation and the contingent pressures are relational to the rate of reaction of the chemical reaction of the gas generating compound 14. At an appropriate gas pressure, the frangible or rupturable front portion of housing 12 in one embodiment in FIG. 1, and the frangible or otherwise rupturable panel 18 in the embodiment shown in FIG. 2 permit release of the gas produced by compound 14. The gas generating compounds are designated as a class 1, subclass 5 or 6 (1.5 or 1.6) according to the publication Ammunition and Explosives Ashore Safety Regulations for Handling, Storing, Renovations and Shaping, Commander Naval Sea Systems Command, Mar. 1, 1995, page 7-2. High yield explosives are listed as 1.1 and 1.2. The size of the compartment containing the gas generating compound is preferably from about 10 inches to about 30 inches long, more preferably from about 15 inches to about 20 inches long. The volume of the compartment is preferably from about 40 in 3 to about 480 in 3 , more preferably from about 60 in 3 to about 180 in 3 . Gas generating compounds used in the present invention include compounds such as ammonium nitrate propellants, hydrazine based propellants, and similar compounds. Most preferably, the explosive is sodium azide. Gas generating compounds which permit the sunder of the subsoil for the present invention are known to those skilled in the art.
Obstruction clearance within surf zones by sundering the supporting subsoil beneath and alongside the obstruction permits use of gas generating compounds which do not have the environmental hazards of noise hazards to wildlife, heavy metals, hydrogen cyanide, hydrochloric acid, and the like. These gas generating compounds do not create craters and berms which are hazardous to assaulting forces in the amphibious operation. Gas generating explosives produce little to no noise, no heavy metals, and generate gases which are mostly carbon dioxide and nitrogen. Additionally, the gas generating compounds are safer to handle and move in comparison to high yield explosives. Accordingly, fewer accidents occur and the gas generating explosives may be more universally used, with training in the use of these explosives occurring more regularly, and reduced amounts of explosives may be used for clearing obstructions.
With gas generating compound 14, as compared to high yield explosives, the slower release of gases permits the sunder, or breaking apart, of the subsoil. This sunder may be characterized as a foaming, "fluidization" or liquidizing of the subsoil. In comparison, the compacted release of gas in high yield explosives tears subsoil particles away from each other. As the gases from the gas generating compound 14 are produced, the projectile 10 is ruptured, at frangible or rupturable portion 12a in FIG. 1 and frangible or rupturable panel 18 in FIG. 2, and the gases escape into the subsoil. The gases destabilize the subsoil, and cause a foaming effect. Formation of large amounts of gas sunder the subsoil support beneath the obstruction, thereby eliminating subsoil support from beneath the obstruction, causing the obstruction to fall into or break loose from the subsoil. When the obstruction has a specific gravity greater than the surrounding water, the weight of the obstruction forces it into the non-support area left by the escaping gases, thereby lowering the obstruction from the water surface and the depth of the obstruction increases to an amount sufficient to permit landing craft to pass over the obstruction and onto the shore. When the specific gravity of the obstruction is less than the surrounding water, the sundered subsoil releases the obstruction and the obstruction is allowed to float away.
The projectile 10 may be launched into the subsoil or placed there by a swimmer, remote arm, robot or the like. When the projectile 10 is launched into the subsoil, a rocket mechanism, or motor, 15 is used. The rocket mechanism 15 has the lift ability to propel the projectile 10 from the launch platform to the area of the obstructions in the surf zone. The rocket mechanism 15 also propels the projectile 10 sufficiently to penetrate through the water and into the subsoil. Preferably, the rocket mechanism 15 propels the projectile through a water depth of from about five feet or less, more preferably from about 8 feet or less, and most preferably ten feet or less. Additionally, the rocket mechanism 15 preferably propels the projectile 10 to penetrate into the subsoil from about 1 foot to about 8 feet, more preferably from about 2 feet to about 6 feet, most preferably from about 3 feet to about 4 feet. Any rocket motor which permits an accurate placement of the projectile 10 is contemplated in the present invention. Accuracy is preferably from about six meters or less, more preferably from about three meters or less, most preferably form about two meters or less distance from the obstruction. The rocket motor 15 is preferably a HYDRA 70 rocket motor by General Dynamic Ordnance Systems of Burlington, Vt. or the Boosted Kinetic Energy Penatrator (BKEP).
The projectile 10 may be launched or fired from a mobile or stationary platform in support of amphibious assault operations. The platforms include amphibious ships, landing craft, support or other sea-going vessels, oil platforms, low and high performance aircraft, land based launch systems and the like. These platforms are only required to be within the effective rocket range of the projectile 10. Preferably, the projectile 10 is launched from any launcher currently in military service. More preferably the projectile 10 is launched from a 2.75 inch rocket launcher. Most preferably, the projectile 10 is launched from a M260, M261 or ground based modified M261 launcher system, manufactured by Harvard Interiors of St. Louis, Mo. One or more projectiles 10 may be directed to a specific obstacle or a barrage of projectiles may be introduced to an obstacle location.
The device present invention may also not have a rocket motor 15 and be placed beneath or alongside an obstruction by a swimmer, remote means such as mechanical arms, extension rods, robots, and the like. Preferably, a hole is dug alongside and beneath the obstruction with the device placed therein. More preferably, several devices are placed alongside and beneath an obstruction. When delivered by a swimmer or remote means, the device comprises a delivery apparatus, which is designed to facilitate swimming or remote means movement, the design of the delivery apparatus known to those skilled in the art.
In operation, the device is delivered immediately before or during an amphibious assault. The device is launched from a platform, after which it travels over the surf zone and enters the water proximate to the obstruction. The projectile 10 travels through the water and is interred in the subsoil proximate to the base of the obstruction in the subsoil. Preferably, the projectile 10 enters the surface of the water and subsoil at an acute angle and stops directly underneath the obstruction. Alternatively, the projectile 10 enters the water surface at a 90° angle, to minimize deflection of the projectile 10 with either the water or subsoil surface. Once interred in the subsoil, the fuse 13 detonates and ignites the gas generating compound 14, allowing it to burn.
FIGS. 3A to 3D show the operation of the present invention. FIG. 3A shows an initial position of a rock obstruction 20 and log post obstruction 30 within a surf zone which has a subsoil 21 and water surface 22. The rock obstruction 20 has a specific gravity greater that the surrounding water and rests on the subsoil 21 with the subsoil 21 supporting the weight of the rock obstruction 20. The rock obstruction 20 has a depth of 6 from the water surface 22 in this initial position. Depth 6 is an amount less than the draft of a landing craft. Also shown in FIG. 3A, log post obstruction 30 has a specific gravity less than the surrounding water and is anchored in the subsoil 21. The depth of δ o of log post obstruction 30 is an amount less than the draft of a landing craft.
In FIG. 3B, shows the placement of a projectile 10 into the subsoil 21, and beneath the rock obstruction 20. The projectile 10 travels along flight line 40, through the water surface 22, passing along the side of the rock 20 and log post 30 obstructions, into subsoil 21, with final placement in a proximate location beneath and alongside rock 20 and log post 30 obstructions. Preferably the projectile 10 enters the water surface 22 at an acute angle φ from the horizontal, to enter the subsoil 21 also at an acute angle φ, allowing the projectile 10 to finally stop beneath and alongside the rock 20 and log post 30 obstructions.
As seen in FIG. 3C, once the projectile 10 is placed proximate to the rock 20 and log post 30 obstructions, the fuse 13 of the projectile 10 detonates and burns the gas generating compound, releasing large amounts of gas. Gas bubbles 23 sunder the subsoil 21 from beneath the obstruction 20. The subsoil 21 mixes with the evolving gas, dissipating and liquidizing the subsoil 21. Once the subsoil 21 is sundered, the gas bubbles 23 escape from beneath and alongside the obstructions 20 and 30, causing the subsoil 21 to foam and liquify. This foaming of the subsoil 21 causes the rock obstruction 20 to fall away from the water surface 22, and causes the log post obstruction 30 to be released and float away from the subsoil 21.
In FIG. 3D, the depth δ of the rock obstruction 20 increases to δ' as the rock obstruction 20 falls into the area of foamed subsoil 21. Depth δ' is a amount which is greater than the draft of a landing craft, allowing the landing craft to pass over the rock obstruction 20 along the water surface 22. Additionally, the foaming of the subsoil 21 release the log post obstruction 30 form the subsoil 21. Once released, the log post obstruction 30 floats to the water surface 22 and floats out of the path of the landing craft. The initial depth δ o of the log post obstruction 30 is eliminated as a threat to the transiting landing craft.
As further seen in FIG. 3D, no craters, berms or voids are created in the subsoil 21 once the rock obstruction 20 and log post 30 obstructions are sunk and cleared from the path of the landing craft. Accordingly, no crater hazard remains for the landing vehicles coming ashore.
Additionally, multiple projectiles 10 may be used either launched as a unit, or in rapid succession. Factors to determine the appropriateness of multiple projectile 10 launches are known by those skilled in the art.
While there have been described what are presently believed to be the preferred embodiments of the invention, those skilled in the art will realize that changes and modifications may be made thereto without departing from the spirit of the invention. It is intended that the claims attached hereto include all such changes and modifications that fall within the true scope of the invention.
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A device for clearing obstructions from surf zones comprising an elongatedenerally cylindrical housing having a first end and a second end, the housing encasing a fuse positioned inside of the first end and a compartment containing a gas generating compound positioned inside of the second end, the fuse detonationally attached to the compound and being capable of causing the compound to initiate burn, the compound having a burn time which is capable of producing sufficient amounts of gas capable of rupturing the housing with the burning of the compound. A method for clearing obstruction which provides the device, interring the device within the subsoil proximate to the obstructions, and, detonating the compound wherein a burning of the compound forms sufficient amounts of gas to rupture the housing and sunder subsoil support of the obstructions effective to clear the obstructions also is disclosed.
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FIELD OF THE INVENTION
[0001] This invention relates in general to fastening devices and more particularly to a fastening device for preventing decorative items, including Christmas stocking holders from falling of a mantle or shelf.
BACKGROUND OF THE INVENTION
[0002] Many people place decorative holder accessories on the edge of fireplace mantels. These decorative accessories support Christmas stockings, Christmas lights, figurines and other decorative items such as garland or strings of mistletoe. Typically, the holder accessory takes the form of a weighted figurine with an attached hanger that extends over the front edge of the mantel. The figurine is weighted heavily to keep not only itself in place, but also to keep it from slipping off the mantle despite the weight of decorations hanging from it hanger. This weighted figurine technique applies well to all mantle surface types, including harder surfaces such as marble or granite. However, weighted figurines have limited weight holding capability. The weighted figurines can be accidentally pulled off a mantel by a child and damage the figurine or flooring beneath the mantle. More importantly, the falling weighted figurine can cause personal injury. This is particularly the case when a curious small child may pull at a stocking, dislodging the figurine and directing the falling object toward the child's face or head. With a typical mantle height a weighted figurine could be traveling between 6 and 10 mph when it strikes a small child. The weighted figurine can cause serious personal injury to the child.
[0003] Most of the currently available Christmas stocking holders are designed for a single purpose, hanging Christmas stockings. Stringing lights, garland or other decorations between stocking holders is not a realistic option for two reasons. First, the hooks are often too small or too awkward to use for anything other than hanging stockings. In addition, the vast majority of these products cannot support the weight of lights or garland. Even the heaviest products tend to slide out of place when items are strung from adjacent stocking holders since they frequently slide on the mantel surface.
[0004] One prior art Christmas stocking holder is taught in U.S. Pat. No. 5,642,819 issued Jul. 1, 1997 to Ernesto Ronia. The stocking holder taught in this patent consists of a plurality of C type clamps that clamp onto the front edge of a mantel or shelf. The clamps are spaced from each other and have a rod passing underneath, and being supported by, the C clamps. Affixed permanently to the top of each of the C clamps is a candle holder. Christmas stockings or other decorations are suspended from the rod that passes underneath and is supported by the C clamps.
[0005] Another prior art means for supporting articles from a mantel, shelf or other planar surface is taught in U.S. Pat. No. 6,378,827 issued Apr. 30, 2002 to Jeffrey Kacines. This means for supporting articles is a one piece metal clip that has a general C shape with decorative additions and a point for hanging items such as Christmas stockings. When the clip is slid onto the edge of a mantel or shelf, the opening of the clip is expanded creating a spring pressure to hold the clip on the edge of the mantel or shelf.
[0006] The above cited prior art teaches a rather complex stocking holder and one that can be too easily pulled from the edge of a mantel or shelf. Therefore, there is a need in the art for an improved device for securing decorative accessories and other items on the front, top edge of a mantel, or hanging from the front edge of a mantel.
SUMMARY OF THE INVENTION
[0007] The foregoing need in the prior art is satisfied by the present invention. A strong, but simple and inexpensive fastening device is taught which can safely hold decorative accessories hanging from the front edge of fireplace mantels or shelves, and at the same time other decorative accessories on the top of the front edge of mantels and shelves. The decorative accessories cannot be inadvertently knocked off or pulled off the mantel or shelf and injure a person such as a child, damage a floor or furniture, and/or break the decorative accessories. Such decorative accessories include, but are not limited to, strings of lights, garland, Christmas stockings, strings of mistletoe, figurines and other decorations.
[0008] The novel fastening device consists of three parts. There is a retainer that attaches to either the rear of the mantle or to a wall behind the mantle. There is a fastener that attaches to an item to be secured or is part of the item. Finally, there is a tether in the form a string or wire that connects the retainer to the fastener. The retainer can take the form of a thin strip of material that can easily be inserted into the space between a mantel or shelf and the wall at the back edge of the mantel or shelf. The fastener attaches to a figurine or other item on top of the mantel or shelf, or to a stocking holder or other item hanging in front of the hangar or shelf, when these items are to be prevented from falling from the mantel or shelf. The tether is a strong line, string or wire that is attached between the retainer and the fastener. The tether prevents a figurine or other item from falling off or being pulled from the front edge of the mantel, including anything else hanging there from or being attached thereto.
[0009] For applications where a weighted stocking holder is not weighted sufficiently, the tether should be used between the retainer and the fastener. This will allow for lighter weight, less expensive, figurine stocking holders. In the case of weighted stocking holders, the tether need not be taught, but short enough to prevent the item from gaining significant velocity should it be pulled from the shelf or mantel. In this case, a single retainer can accommodate several fasteners or items.
[0010] As mantels come in many widths a way is provide for adjusting the length of the tether so that the weighted stockholding or other item will always remain in the proper position at the front edge of the mantel or shelf.
DESCRIPTION OF THE DRAWING
[0011] The invention will be better understood upon reading the following Detailed Description in conjunction with the drawing in which:
[0012] FIG. 1 shows an embodiment of the invention having a fastener with a candle holder and candle that sits on the front edge of a mantel and has an integral hook that extends over the edge of the mantel for hanging a Christmas stocking, a light string, garland or other ornaments.
[0013] FIG. 2 shows another embodiment of the invention that has a flat fastener that sits on the front edge of a mantel, and has an integral hook that extends over the edge of the mantel for hanging a Christmas stocking, a light string, garland or other ornaments;
[0014] FIG. 3 shows a view of a portion of a fastener and retainer and a tether;
[0015] FIG. 4 shows a view of a portion of the fastener and retainer and how the tether connects the two; and
[0016] FIG. 5 shows an embodiment of the invention that is used with a weighted stocking holder in the form of a figurine.
DETAILED DESCRIPTION
[0017] The subject invention is a novel, simple and inexpensive, yet safe fastening apparatus for securing decorative items, including Christmas stocking holders, to the front edge of a mantle or shelf, and/or retaining other decorative items on top of the mantel or shelf.
[0018] FIG. 1 shows the invention used on a fireplace mantel 10 and FIG. 2 shows the invention used on a shelf 20 . FIG. 5 shows the invention used on a fireplace mantel with a weighted stocking holder that has a ceramic or metallic figurine. The version of the novel apparatus shown in FIG. 1 has a hangar 13 with an integral candle holder 16 . In addition, one version of a retainer 12 of the invention is shown in FIG. 1 and a variant retainer 22 is shown in FIG. 2 . They perform the same function and may be interchanged. In addition, one hangar 13 is shown in FIG. 1 and a variant hangar 23 is shown in FIG. 2 . They perform the same function and may be interchanged. The hangar 13 shown in FIG. 1 , with integral candle holder 16 , may be used on a shelf 20 with retainer 22 ; and hangar 23 shown in FIG. 2 may be used with mantel 10 in FIG. 1 . Only two figures are shown for the sake of simplicity.
[0019] FIG. 1 shows a brick fireplace 11 with a mantel 10 thereon on which the invention is used to hang a stocking 19 at Christmas time. This embodiment of the invention has a hangar 13 that may be made of metal or plastic and sits on the top front edge of mantel 10 . Hangar 13 has a J hook 14 extending down over the front edge of mantel 10 on which stocking 19 is hung with a loop of material 19 a often made as part the stocking.
[0020] The invention also has a retainer 22 that wedges in between mantel 10 and wall 29 into which the brick fireplace 11 is built. In FIG. 1 retainer 12 is a relatively thin, flat piece of material that can be pushed between wall 29 and the back edge of mantel 10 as shown. Retainer 12 includes a ring 12 a attached thereto upon which force can be applied to push retainer 12 between wall 29 and mantel 10 . A tether in the form of a string, wire or plastic line 18 (hereinafter referred to as tether 18 ) can preferably be tied to ring 12 a before retainer 12 is inserted between the wall and mantel, but it can be tied afterwards. Alternatively, instead of using retainer 12 a screw hook or eyelet screw (not shown) may be screwed into the wall at or near the point where retainer 12 would be inserted between wall 29 and mantel 10 . Tether 18 is tied to the screw hook or eyelet screw instead of to ring 12 a.
[0021] Hangar 13 has a small tab 15 at its rear edge that angles up and away from the top surface of mantel 10 . Tab 15 has a hole there through (not shown in FIG. 1 but shown in FIGS. 3 and 4 ). Hangar 13 , without stocking 19 and candle 17 is set on the top front edge of mantel 10 as shown and tether 18 is passed through the hole in tab 15 and is tied thereto. Tether 18 is strong enough to prevent hangar 13 from being pulled from the mantel 10 when a fair amount of pulling force is applied to hangar 13 or anything hung thereon, such as stocking 19 . Stocking 19 is hung from J hook 14 of hangar 13 using loop 19 a as shown. A candle 17 is then inserted into candle holder 16 . Candle 17 can be a real candle or may be one of the newer battery powered candles that are common. If a candle 17 is not desired a figurine or other decoration may be placed on top of and may be fastened to candle holder 16 .
[0022] A number of hangars 13 (not shown), as described in the previous paragraph, may be spaced along the front edge of mantel 10 and garland or a string of lights may be strung along the top of the J hook 14 of each hangar 13 . In addition, while a stocking 19 is shown hung from hangar 13 , anything else may be hung there from within its weight limitations.
[0023] As briefly mentioned above, the retainer 22 of FIG. 2 may be used in lieu of retainer 12 in FIG. 1 .
[0024] FIG. 1 shows a wall 29 with a shelf 20 fastened thereto, and having vertical support from element 21 . The invention is used with shelf 20 to hang a stocking 28 or other decorative ornament thereon. This embodiment of the invention has a hangar 23 that may be made of metal or plastic and sits on the top front edge of shelf 20 as shown. Hangar 23 has a J hook 24 extending down over the front edge of shelf 20 on which a stocking 28 is hung with a loop of material 28 a often made as part the stocking.
[0025] FIG. 2 shows another embodiment of a part of the invention. Retainer 22 is a relatively thin, L shaped piece of metal that can be pushed between wall 29 and the back edge of shelf 20 as shown. Instead of a ring as in FIG. 1 , retainer 22 has a tab 22 a that angles up and away from the top of shelf 20 and has a hole there through (not shown in this Figure but shown in FIGS. 3 and 4 ). For ease of installation a piece of string, wire or plastic line 26 (hereinafter referred to as tether 26 ) can preferably be tied through the hole in tab 22 a before clip 22 is inserted between the wall and mantel, but it can be tied thereto afterwards. Hangar 23 has a small tab 25 at its rear edge that angles up and away from the top of mantel 20 . Tab 25 also has a hole there through (not shown in FIG. 2 but shown in FIGS. 3 and 4 ). Hangar 23 , without stocking 28 hanging there from, is set on the top front edge of mantel 20 as shown and tether 18 is passed through the hole in tab 25 and is tied thereto. Tether 18 is strong enough to prevent hangar 23 from being pulled from mantel 10 when a fair amount of pulling force is applied to hangar 23 or anything hung thereon, such as stocking 28 . Stocking 28 is then hung from J hook 24 of hangar 23 using loop 28 a as shown.
[0026] In the following paragraphs an alternative way of attaching a hangar to a retainer is described. With this alternative no tying of a tether is required. While the following description is with reference to tab 25 of hangar 23 in FIG. 2 , it also applies to retainer 22 with its tab 22 a in FIG. 2 , and to hangar 13 with its tab 15 in FIG. 1 . With this alternative way of attaching a hangar to a retainer, the retainer 12 in FIG. 1 is not utilized because a ring 12 a is not needed. Only a retainer such as retainer 22 is needed because it has a tab 22 a with a keyhole shaped hole 30 through it.
[0027] FIG. 3 shows an alternative way of attaching hangar 23 to retainer 22 in FIG. 2 . Shown is a partial view of hangar 23 without J hook 24 . Tab 25 of hangar 23 has a hole 30 through it as previously described with reference to FIG. 2 . Hole 30 is keyhole shaped and has an elongated slot 30 a and a larger diameter portion 30 b . Instead of using string or wire as shown and described with reference to FIGS. 1 and 2 , the tether 26 is a strong plastic line 26 having molded, spaced beads 26 a along it. With this tether 26 there is no manual tying to be done to assemble and use the novel holding apparatus. The diameter of beads 18 a is only slightly less than the diameter of portion 30 b of the hole 30 and the diameter of line 26 between beads 26 a is only slightly less than the diameter of elongated slot 30 a.
[0028] FIG. 4 shows the alternative tether 26 attached to tab 25 of hangar 23 . Tether 26 and some number of its beads 26 a are first inserted through the larger diameter portion 30 b of hole 30 . This can be done because of the relative dimensions as described in the previous paragraph. After beaded tether 26 is inserted through hole portion 30 b a sufficient amount it is moved upward into elongated slot 30 a . Since beads 26 a have a diameter larger than the width of slot 30 a beaded tether 26 cannot be pulled back through tab 25 .
[0029] When using the beaded tether 26 as part of the invention, retainer 22 is first inserted between wall 29 and the rear edge of shelf 20 or a mantel 10 . Tab 22 a has a keyhole shaped hole 30 through it, alike that shown in FIGS. 2 and 3 , through which at least the first bead 26 a on a first end of tether 26 is inserted through portion 30 b and is then slid up into the elongated slot 30 a in tab 22 a . With hangar 23 positioned on the top front edge of shelf 20 or mantel 10 the other (second) end of beaded line 26 is inserted through portion 30 b of keyhole shaped hole 30 through hangar 23 until there is no slack in beaded tether 26 . Tether 26 is then slid up into the elongated slot 30 a of tab 25 . With no slack in beaded tether 26 hangar 23 cannot fall off mantel 10 or shelf 20 . Any excess length of beaded line 26 after it passes through hole 30 in tab 25 of hangar 23 may be cut off.
[0030] FIG. 5 shows another embodiment of the invention wherein the invention is used with an existing weighted stocking holder 13 that has a ceramic or metallic figurine 33 . Such a weighted stocking holder 13 has a J hook 14 that has a stocking 19 hung there from as previously described with reference to FIG. 1 . If a child pulls on such a weighted stocking holder 13 , without the use of the invention, the holder would fall and obviously do damage to the face of the child.
[0031] In this embodiment of the invention there would be no hangar with J hook because it is already part of the prior art weighted stocking holder 33 . Instead the hangar 13 of FIG. 1 is replaced by a flat metallic or plastic base plate 34 that is adhesively fastened to the bottom of the weighted stocking holder 13 . Base 34 has a tab 15 with a hole there through, as described with reference to FIG. 1 , to which tether 18 is tied or attached. Base 34 may also be manufactured as an integral part of the weighted stocking holder 33 .
[0032] As previously described with reference to FIG. 1 there is a retainer 12 that wedges in between mantel 10 and the wall 29 into which the brick fireplace 11 is built. Retainer 12 includes a ring 12 a attached thereto upon which force can be applied to push retainer 12 between wall 29 and mantel 10 . Tether 18 is tied to ring 12 a before retainer 12 is inserted between the wall and mantel, but it can be tied afterwards. Alternatively, instead of using retainer 12 , retainer 22 or a screw hook or eyelet screw (not shown) may be screwed into the wall at or near the point where retainer 12 would be inserted between wall 29 and mantel 10 . Tether 18 is tied to the screw hook or eyelet screw instead of to ring 12 a . Base 34 has a small tab 15 at its rear edge that angles up and away from the top of mantel 10 . Tab 15 has a hole there through as previously described with reference to FIG. 1 to which tether 18 is tied. Tether 18 is strong enough to prevent figurine 33 and stocking 19 from being pulled from mantel 10 when a fair amount of pulling force is applied thereto. Instead of tether 18 the alternative tether means shown in and described with reference to FIGS. 3 and 4 may also be used.
[0033] This embodiment of the invention may alternatively also be used for retaining only a figurine 33 or other decorative item sitting near the front edge of a shelf or mantel 10 . The J hook 14 does not exist in this application. Figurine 33 preferably has made as part thereof base 34 that has a tab 15 to which tether 18 is tied or otherwise attached. However, base 10 may be adhesively attached to the bottom of separate figurine 33 by a purchaser of the invention. The retainer 12 is as previously described, and the alternative retaining means shown in and described with reference to FIGS. 3 and 4 may be used instead. The figurine 33 with base 34 attached thereto is secured using tether 18 and retainer 12 or alternative screw hook or eyelet screw as previously described.
[0034] While what has been described herein is the preferred embodiment of the invention it will be understood by those skilled in the art that numerous changes may be made without departing from the spirit and scope of the invention. For example, when the invention is used on a shelf 20 , retainer 22 a can alternatively be a U shaped piece of material that is inserted onto the back edge of the shelf with one portion underneath the shelf, a second portion at the rear of the shelf, and a third portion on top of the shelf. Tether 26 is attached to the first portion that extends on top of the shelf. This alternative embodiment is practical because shelving material is generally of a common thickness.
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An apparatus is disclosed for securing decorative items such as figurines, lights, garland and Christmas stockings on top of or hanging over the front edge of a shelf or mantel. The apparatus has a retainer that is secured to the wall or the rear of a mantel or shelf, a fastener that is fixed to the decorative item, and an adjustable length tether connecting the two. The retainer is preferably a flat piece that inserts between the rear edge of the shelf or mantel but may be a U shaped clip mounted on the back edge of a shelf. The apparatus prevents the decorative items from being accidentally knocked off or pulled off the shelf or mantel.
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CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application earlier filed in the Korean Intellectual Property Office on the 20 Mar. 2012 and there duly assigned Serial. No. 10-2012-0028390.
BACKGROUND OF THE INVENTION
1. Field of the Invention
One or more embodiments of the present invention relate to a thin film depositing apparatus for generating a process gas of a deposition source and depositing the process gas on a surface of a substrate, and more particularly, to a thin film depositing apparatus for performing a deposition process by reciprocating with respect to a deposition source and a thin film depositing method used by the thin film depositing apparatus.
2. Description of the Related Art
A deposition process whereby a process gas generated from a deposition source is deposited on a surface of a substrate is widely used in a thin film manufacturing process, such as a thin film transistor manufacturing process of an organic light-emitting display device.
Recently, an atomic layer deposition (ALD) process, whereby a thin film may be more uniformly and precisely formed, has been preferred. In such an ALD process, deposition is repeatedly performed at the same location on a substrate more than 300 times.
Thus, to perform such a repetitive deposition process, a scan-type deposition process where a substrate is mounted on a transfer shuttle in a deposition chamber and reciprocates with respect to a deposition source is used.
In general, auxiliary plates having the same size as that of a mounting unit for the substrate are attached to the front and rear parts of the transfer shuttle. The auxiliary plates alternately close a process gas outlet whenever the substrate passes the process gas outlet of the deposition source, which is positioned in the deposition chamber. For example, when the substrate mounted on the transfer shuttle is transferred in one direction, the auxiliary plate at the front part of the transfer shuttle closes the process gas outlet before the substrate enters the process gas outlet of the deposition source, and then, after the substrate passes the process gas outlet, the auxiliary plate at the rear part of the transfer shuttle closes the process gas outlet. That is, the auxiliary plate at the front part of the transfer shuttle, a mounting plate of the transfer shuttle, and the auxiliary plate at the rear part of the transfer shuttle are alternately positioned in front of the process gas outlet of the deposition source, by reciprocating across the front of the process gas outlet.
As described above, the process gas outlet is alternately closed by the auxiliary plates. This is because a state of a process gas of the deposition source is maintained constant while a deposition process is performed. If the auxiliary plates are not used, the process gas outlet is in a completely opened state before and after the transfer shuttle passes the process gas outlet, and thus, the inside of the deposition chamber may be severely contaminated by the process gas of the deposition source. To prevent such a contamination, a separate shutter can be installed at the deposition source so that a process gas is discharged only when a substrate on the transfer shuttle passes the process gas outlet, which leads to less contamination to surroundings. However, a state of the process gas discharged from the process gas outlet is not maintained constant, and thus, this cannot ensure a uniform deposition quality. Therefore, the auxiliary plates are installed at the transfer shuttle so as to constantly discharge the process gas of the deposition source and alternately close the process gas outlet.
However, when the auxiliary plates are installed at the front and rear parts of the mounting plate of the transfer shuttle, the size of a deposition chamber needs to be increased corresponding to the size of the auxiliary plates. That is, since the auxiliary plates having almost the same size as that of the mounting plate are installed at the front and rear parts of the transfer shuttle, a sufficient space for a reciprocating operation needs to be secured, considering the sizes of the transfer shuttle and the auxiliary plates, and the size of the deposition chamber also needs to be increased corresponding thereto.
Therefore, there is a need to develop a method of effectively decreasing the size of a deposition chamber by using auxiliary plates.
SUMMARY OF THE INVENTION
One or more embodiments of the present invention provide a thin film depositing apparatus that uses auxiliary plates for alternately closing a process gas outlet of a deposition source and has an improved structure for the miniaturization of a deposition chamber, and a thin film deposition method using the thin film depositing apparatus.
According to an aspect of the present invention, there is provided a thin film depositing apparatus including a deposition chamber through which a process gas outlet of a deposition source is arranged; a transfer shuttle disposed in the deposition chamber, the transfer shuttle comprising a mounting plate for loading a substrate, the transfer shuttle being reciprocal with respect to the process gas outlet; and at least one bendable auxiliary plate installed at one side of the transfer shuttle, the bendable auxiliary plate closing the process gas outlet when opposite the process gas outlet, the bendable auxiliary plate comprising a folding member for placing the bendable auxiliary plate in each of an unbent state and bent state dependent upon the position of the transfer shuttle.
The bendable auxiliary plate may have a main body part attached to the one side of the transfer shuttle and an end part, wherein the folding member may include a hinge shaft rotatably connecting the end part to a main body part of the auxiliary plate, and an actuator rotating the end part with respect to the hinge shaft, the actuator performing a bending and unbending operation of the bendable auxiliary plate.
The apparatus may further include another auxiliary plate installed at an opposite side of the transfer shuttle, the another auxiliary plate closing the process gas outlet when opposite the process gas outlet.
The another auxiliary plate may be unbendable.
The another auxiliary plate may be bendable and include a corresponding folding member.
The end part of the bendable auxiliary plate may be disposed alongside a corresponding sidewall of the deposition chamber when the another auxiliary plate is disposed opposite the process gas outlet.
Each of the auxiliary plates may bent to dispose the corresponding end parts alongside a corresponding sidewall of the deposition chamber when the other of the auxiliary plates is unbent and disposed opposite the process gas.
The bendable auxiliary plate may be unbent while the transfer shuttle is reciprocated with respect to the process gas outlet, while the end part of the bendable auxiliary plate may be disposed alongside a corresponding sidewall of the deposition chamber when the process gas outlet is not closed and the transfer shuttle is stationary.
According to another aspect of the present invention, there is provided a thin film depositing method including: loading a substrate on a mounting plate attached to a transfer shuttle disposed within a deposition chamber, the transfer shuttle being reciprocal with respect to a process gas outlet and having first and second auxiliary plates installed on opposite sides of the mounting plate, the first auxiliary plate being in an unbent state closing the process gas outlet and the second auxiliary plate being in a bent state, when loading the substrate; moving the transfer shuttle across the process gas outlet to perform a deposition process; unbending the second auxiliary plate when moving the transfer shuttle across the process gas outlet in a first direction and closing the process gas outlet with the second auxiliary plate when the transfer shuttle moves passed the process gas outlet; and bending the second auxiliary plate when moving the transfer shuttle across the process gas outlet in a second direction opposite the first direction.
The depositing method may include bending the first auxiliary plate when moving the transfer shuttle past the process gas outlet in the first direction, and unbending the first auxiliary plate when moving the transfer shuttle across the process gas outlet in the second direction.
According to another aspect of the present invention, there is provided a thin film depositing method including: loading a substrate on a mounting plate attached to a transfer shuttle disposed within a deposition chamber in a loading position, the transfer shuttle being reciprocal with respect to a process gas outlet and having first and second auxiliary plates installed on opposite sides of the mounting plate, the first auxiliary plate being in an unbent state and the second auxiliary plate being in a bent state, when loading the substrate; moving the transfer shuttle in a first direction; closing the process gas outlet with the first auxiliary plate and unbending the second auxiliary plate, while moving the transfer shuttle in the first direction; forming a deposition process on the substrate when the transfer shuttle crosses the process gas outlet while moving in the first direction; closing the process gas outlet with the second auxiliary plate when the transfer shuttle passes the process gas outlet in the first direction; moving the transfer shuttle in a second direction opposite the first direction; forming a deposition process on the substrate when the transfer shuttle crosses the process gas outlet while moving in the second direction; and closing the process gas outlet with the first auxiliary plate when the transfer shuttle passes the process gas outlet in the second direction.
The depositing method may include repeatedly moving the transfer shuttle in the first and second directions until the deposition process is completed, and bending the second auxiliary plate while moving the transfer shuttle to the loading position.
According to the thin film depositing apparatus and the thin film depositing method, the auxiliary plate suitable for use in constantly maintaining a state of a process gas of a deposition source may be used, and, thanks to the use of the auxiliary plate, a burden of increasing the size of the deposition chamber may be alleviated.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference symbols indicate the same or similar components, wherein:
FIGS. 1A through 1C are diagrams illustrating a structure and a sequential operation of a thin film depositing apparatus according to an embodiment of the present invention;
FIGS. 2A and 2B are diagrams sequentially illustrating an operation of an auxiliary plate of the thin film depositing apparatus illustrated in FIGS. 1A through 1C , according to embodiments of the present invention;
FIGS. 3A through 3C are diagrams illustrating a structure and a sequential operation of a thin film depositing apparatus according to another embodiment of the present invention; and
FIGS. 4A through 4D are diagrams illustrating a structure and a sequential operation of a thin film depositing apparatus according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
First, a thin film depositing apparatus according to an embodiment of the present invention will now be described with reference to FIGS. 1A through 1C .
Referring to FIGS. 1A through 1C , the thin film depositing apparatus includes a deposition chamber 10 including a process gas outlet 11 through which a process gas of a deposition source is discharged and a transfer shuttle 100 for mounting a substrate 1 which reciprocates across the front of the process gas outlet 11 and then passes the process gas outlet 11 .
The transfer shuttle 100 on which the substrate 1 is mounted on a mounting plate 101 reciprocates at a position where the substrate 1 and the process gas outlet 11 face each other and passes the process gas outlet 11 , and deposition is performed on the substrate 1 through the process gas outlet 11 .
The transfer shuttle 100 includes an auxiliary plate 110 and an auxiliary plate 120 that are installed at the front and rear sides of the transfer shuttle 100 . The auxiliary plates 110 and 120 screen the process gas outlet 11 . If the process gas outlet 11 is completely in an opened state after the substrate 1 on the mounting plate 101 passes the process gas outlet 11 , the inside of the deposition chamber 10 is severely contaminated. Thus, to prevent contamination, the auxiliary plates 110 and 120 at the front and rear sides of the transfer shuttle 100 alternately screen the process gas outlet 11 .
As illustrated in FIGS. 1A through 1C , the auxiliary plates 110 and 120 each include a folding member 130 that performs a bending or unbending operation. In other words, the folding member 130 is unbent at a position where the process gas outlet 11 is screened, and the folding member 130 is bent at a position adjacent to side walls 12 or 14 of the deposition chamber 10 . Accordingly, the auxiliary plates 110 and 120 are bent whenever approaching the side walls 12 or 14 of the deposition chamber 10 , resulting in a decrease in a length of each of the auxiliary plates 110 and 120 , whereby a space of the deposition chamber 10 may be minimized. If each of the auxiliary plates 110 and 120 does not include the folding member 130 , a space where the auxiliary plates 110 and 120 are transferred in a completely unbent state needs to be secured, and thus, the size of the deposition chamber 10 needs to be increased corresponding to the secured space. In this embodiment, however, the auxiliary plates 110 and 120 may be bendable so that the space of the deposition chamber 10 may be decreased.
The folding member 130 may be configured as illustrated in FIGS. 2A and 2B . Referring to FIGS. 2A and 2B , the auxiliary plate 120 is illustrated, and the auxiliary plate 110 also has the same structure as that of the auxiliary plate 120 .
The auxiliary plate 120 includes a main body part 121 fixed to the transfer shuttle 100 (not shown) and an end part 122 that is rotatably connected to the main body part 121 with respect to a hinge shaft 131 . An actuator 132 is installed to connect the main body part 121 and the end part 122 and may be, for example, an air cylinder. In this regard, when the actuator 132 contracts, as illustrated, in FIG. 2A , the end part 122 is bent by 90 degrees with respect to the main body part 121 , thereby decreasing the length of the auxiliary plate 120 in a proceeding direction thereof. On the other hand, when the actuator 132 expands, as illustrated in FIG. 2B , the end part 122 is unbent and lies in parallel with the main body part 121 .
The thin film depositing apparatus, including the bendable-type auxiliary plates 110 and 120 may operate as follows.
First, the substrate 1 on which deposition is to be performed is mounted on the mounting plate 101 of the transfer shuttle 100 . The mounting of the substrate 1 is generally performed using a robot arm (not shown).
Subsequently, when the mounting of the substrate 1 is completed, a deposition process is initiated with a reciprocating operation of the transfer shuttle 100 . At this time, a process gas of a deposition source is constantly discharged through the process gas outlet 11 . In this regard, as illustrated in FIG. 1A , when the transfer shuttle 100 is transferred in a right direction, the auxiliary plate 110 is in a unbent state and closes the process gas outlet 11 , and the auxiliary plate 120 is bent to be adjacent to a side wall 12 of the deposition chamber 10 so that the length of the auxiliary plate 120 is decreased.
As illustrated in FIG. 1B , when the transfer shuttle 100 is transferred in a left direction from this state, the mounting plate 101 of the transfer shuttle 100 faces the process gas outlet 11 and then a deposition process starts being performed on the substrate 1 . Meanwhile, the auxiliary plate 120 is unbent and prepares to close the process gas outlet 11 .
Subsequently, as illustrated in FIG. 1C , when the transfer shuttle 100 is transferred further in a left direction, the auxiliary plate 120 that has unbent closes the process gas outlet 11 , and the auxiliary plate 110 is bent to be adjacent to an opposite side wall 14 of the deposition chamber 10 .
A transfer of the transfer shuttle 100 in an inverse direction is performed in an inverse order to that described above. When an atomic layer deposition (ALD) process, which has been recently used, is performed, such a reciprocating operation is repeatedly performed hundreds of times.
Therefore, according to this embodiment, the auxiliary plates 110 and 120 that alternately close the process gas outlet 11 have a bendable function, and thus, the size of the deposition chamber 10 may be smaller than that of a conventional fixed-type deposition chamber. In other words, the deposition chamber 10 includes the auxiliary plates 110 and 120 and thus allows a process gas to be discharged from a deposition source, whereby the size of the deposition chamber 10 may be decreased.
FIGS. 3A through 3C are diagrams illustrating a structure and a sequential operation of a thin film depositing apparatus according to another embodiment of the present invention.
In the previous embodiments, the auxiliary plates 110 and 120 are of a bendable type. In this embodiment, however, an auxiliary plate 220 is a bendable type and an auxiliary plate 210 is of a fixed type. That is, as the number of driving elements increases, a breakdown may frequently occur, and thus, only the auxiliary plate 220 is configured to be of a bendable type, whereby the size of a deposition chamber 20 is decreased and the number of driving elements is also decreased accordingly. The folding member 130 of the auxiliary plate 220 may have the same structure as that of the folding member 130 of the auxiliary plate 120 illustrated in FIGS. 2A and 2B .
The thin film depositing apparatus including the fixed-type auxiliary plate 210 and the bendable-type auxiliary plate 220 may operate as follows.
First, a substrate 1 on which deposition is to be performed is mounted on a mounting plate 201 of a transfer shuttle 200 . The mounting of the substrate 1 is generally performed using a robot arm (not shown).
Subsequently, when the mounting of the substrate 1 is completed, a deposition process is initiated with a reciprocating operation of the transfer shuttle 200 . At this time, a process gas of a deposition source is constantly discharged through a process gas outlet 21 . In this regard, as illustrated in FIG. 3A , when the transfer shuttle 200 is transferred in a right direction, the auxiliary plate 210 closes the process gas outlet 21 , and the auxiliary plate 220 positioned adjacent to a side wall 22 of the deposition chamber 20 is bent so that the length of the auxiliary plate 220 is decreased.
As illustrated in FIG. 3B , when the transfer shuttle 200 is transferred in a left direction from this state, the mounting plate 201 of the transfer shuttle 200 faces the process gas outlet 21 and a deposition process starts being performed on the substrate 1 . Meanwhile, the auxiliary plate 220 is unbent and prepares to close the process gas outlet 21 .
Subsequently, as illustrated in FIG. 3C , when the transfer shuttle 200 is transferred further in a left direction, the auxiliary plate 220 that has unbent closes the process gas outlet 21 .
A transfer of the transfer shuttle 200 in an inverse direction is performed in an inverse order to that described above.
Therefore, according to this embodiment, the auxiliary plate 220 has a bendable function, and thus, the size of the deposition chamber 20 may be decreased. In addition, the auxiliary plate 210 is of a fixed type, and thus, the number of driving elements may also be appropriately decreased.
FIGS. 4A through 4D are diagrams illustrating a structure and a sequential operation of a thin film depositing apparatus according to another embodiment of the present invention.
As in the previous embodiment, in this embodiment, only an auxiliary plate 320 is of a bendable type, and an auxiliary plate 310 is of a fixed type. A folding member 130 of the auxiliary plate 320 may have the same structure as that of the folding member 130 of the auxiliary plate 120 illustrated in FIGS. 2A and 2B .
In this embodiment, a bendable operation of the auxiliary plate 320 is not performed during a reciprocating process for deposition, but, when a transfer shuttle 300 is transferred to a loading position for loading or unloading a substrate 1 on or from a mounting plate 301 , the auxiliary plate 320 is bent.
That is, if desired, as illustrated in FIGS. 4A through 4D , a deposition chamber 30 in which the loading position for loading or unloading the substrate 1 is further arranged at an outer side of a reciprocating position may be used.
In this embodiment, the auxiliary plate 320 is bent adjacent to a side wall 32 of the deposition chamber 30 only at the loading position so as to decrease the length thereof, and the auxiliary plate 320 is in a continuously unbent state during a reciprocating process for deposition. This is because the reciprocating process is repeatedly performed hundreds of times in a deposition process such as ALD, and thus, if the auxiliary plate 320 is bent or unbent whenever the reciprocating process is performed, this may be a burden on the folding member 130 .
Therefore, the auxiliary plates 310 and 320 are in a completely unbent state while being transferred, and the auxiliary plate 320 is bent only at the loading position, which contributes to decreasing the size of the deposition chamber 30 to some extent, as compared to a case where both the auxiliary plates 310 and 320 are of a fixed type.
The thin film depositing apparatus including the deposition chamber 30 that further secures the loading position may operate as follows:
First, as illustrated in FIG. 4A , the transfer shuttle 300 is transferred to the loading position and a substrate 1 on which deposition is to be performed is mounted on a mounting plate 301 . The mounting of the substrate 1 is generally performed using a robot arm (not shown). In this regard, the auxiliary plate 320 is in a bent state adjacent to the side wall 32 of the deposition chamber 30 .
Subsequently, when the mounting of the substrate 1 is completed, a deposition process is initiated with a reciprocating operation of the transfer shuttle 300 . At this time, a process gas of a deposition source is constantly discharged through a process gas outlet 31 . In this regard, as illustrated in FIG. 4B , when the transfer shuttle 300 lies on the right side of the process gas outlet 31 , the auxiliary plate 310 , which is of a fixed type, closes the process gas outlet 11 , and the auxiliary plate 320 , which is of a bendable type, is in a continuously unbent state during the reciprocating process.
As illustrated in FIG. 4C , when the transfer shuttle 300 is transferred in a left direction from this state, the mounting plate 301 of the transfer shuttle 300 faces the process gas outlet 31 and the deposition process is then performed on the substrate 1 .
Subsequently, as illustrated in FIG. 4D , when the transfer shuttle 300 is transferred further in a left direction, the auxiliary plate 320 closes the process gas outlet 31 .
A transfer of the transfer shuttle 300 in an inverse direction is performed in an inverse order to that described above.
Therefore, according to the present embodiment, the auxiliary plate 320 is bent at the loading position, and thus, the size of the deposition chamber 30 may be decreased. In addition, both the auxiliary plates 310 and 320 are in an unbent state during the reciprocating process, and thus, there is a decreasing probability of a breakdown due to a frequent bending operation.
As described above, according to the one or more embodiments of the present invention, a thin film depositing apparatus includes an auxiliary plate suitable for use in constantly maintaining a state of a process gas of a deposition source, whereby a burden of increasing the size of a deposition chamber may be appropriately alleviated.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
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A thin film depositing apparatus and a thin film depositing method used by the thin film depositing apparatus. The thin film depositing apparatus includes a deposition chamber through which a process gas outlet of a deposition source is arranged; a transfer shuttle disposed in the deposition chamber, the transfer shuttle comprising a mounting plate for loading a substrate, the transfer shuttle being reciprocal with respect to the process gas outlet; and at least one bendable auxiliary plate installed at one side of the transfer shuttle, the bendable auxiliary plate closing the process gas outlet when opposite the process gas outlet, the bendable auxiliary plate comprising a folding member for placing the bendable auxiliary plate in each of an unbent state and bent state dependent upon the position of the transfer shuttle.
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FIELD OF THE INVENTION
This invention relates to a method of encapsulating flavors or fragrances into microcapsules having a hydrogel shell and an oil core.
BACKGROUND OF THE INVENTION
Microcapsules incorporating a flavor or fragrance compound are useful to provide a controlled release of the contained flavor or fragrance. Such products may be used in the food processing industry, where encapsulated flavor particles may provide a flavor burst upon chewing the food. Such products may also be used in the cosmetic and toiletry industries, where encapsulated fragrance particles may provide a burst of scent upon capsule fracture. The capsule may comprise a shell surrounding a core material in which the flavor or fragrance compound is contained.
Microcapsules may be formed by a coacervation or crosslinking process, in which lipids are coated by tiny droplets of proteins, carbohydrates, or synthetic polymers suspended in water. The process of coacervation is, however, difficult to control and depends on variables such as temperature, pH, agitation of the materials, and the inherent variability introduced by a natural protein or carbohydrate.
In the manufacture of microcapsules containing a flavor or fragrance compound, several features are desirable. It is desirable to produce microcapsules that have strong walls and that do not agglomerate. It is desirable that the compound be readily loaded into an oil microparticle, that is, be readily absorbed into the oil core of the microcapsule. Once absorbed, it is also desirable that the compound be irreversibly retained in the oil core of the microcapsule, that is, be adsorbed into the microcapsule.
The amount of compound that may be encapsulated depends upon several factors including its solubility in water, partition coefficient, molecular weight, water content, volatility, and the ratio of blank capsule to water amounts. Flavors and fragrances may be mixtures of hundreds of components, each of which may widely in these properties. A flavor or fragrance compound that is lipophilic may be readily contained in an oil core of a microcapsule, while a flavor or fragrance compound that is hydrophilic may be less readily contained in an oil core. For example, the flavor compound diacetyl (DA) is about 20% to about 30% water soluble. For diacetyl, typical maximum absorption into an oil is up to only about 55%. A highly water soluble compound such as diacetyl is also more difficult to retain in the oil core once it is loaded.
A compound's solubility in an aqueous phase versus an oil phase is determined by its partition coefficient, abbreviated as K. The partition coefficient of a compound is the ratio of the compound's concentration in one liquid phase to the compound's concentration in another liquid phase. The partition coefficient thus is an inherent property of the compound with two given liquid phases, such as a lipid phase and an aqueous phase, and reflects the compound's distribution at equilibrium between the water phase and the lipid phase. Any means of decreasing the water solubility of a compound will shift the at equilibrium of the compound and thus shift its partitioning between an aqueous phase and a lipid phase. For example, addition of a salt will decrease the water solubility of a compound and will increase its partitioning into the lipid phase. Similarly, crosslinking a protein membrane to strengthen the membrane and physically decrease the amount of water, or physically removing water from the environment, causing capsule wall or membrane shrinking, will decrease the water solubility of a compound and will increase its partitioning into the oil phase.
Flavors or fragrances that are water soluble may interfere with encapsulation of an oil particle. For example, flavor or fragrance compounds that are water soluble cannot be encapsulated using gelatin coacervation. This is because for coacervation to occur, there must be a droplet to coat, and for these water soluble materials, there are no droplets to coat. In addition, the water soluble flavor or fragrance may partition so as to locate the flavor or fragrance compound in an aqueous environment outside the encapsulated oil particle rather than inside the oil particle. If a flavor or fragrance compound is too water soluble, the coacervation process ceases to function due to the colloid becoming either too thick or too thin. A colloid that is too thick has no flow, and thus cannot properly coat the oil surface. A colloid that is too thin is not retained on the oil surface. In the extreme, a water soluble flavor or fragrance compound can totally solubilize the colloid, leaving no wall material to deposit on the oil surface.
Besides water solubility, a flavor or fragrance compound that contains fatty acids affects the pH of a coacervation reaction. If a base is added in an attempt to adjust pH, the fatty salts produced in the reaction impart an undesirable soap taste to a flavor compound. If a flavor or fragrance compound contains water soluble esters, the coacervation temperature is affected and hence the final gelation temperature is altered. While it is therefore desirable to limit compounds that contain either fatty acids or water soluble esters, there is a tradeoff in the potency and profile results for the encapsulated compound. This limits the range of formulations that are able to be effectively encapsulated.
Currently, flavor or fragrance compounds that are difficult to encapsulate are diluted with oils such as vegetable oil or mineral oil. This alters its oil to water partition coefficient, in which the compound attempts to reach an equilibrium between the oil and aqueous phases. The oil serves to reduce the natural water solubility of most compounds and, in many cases, reduces it below the level at which it interferes with coacervation. A flavor or fragrance compound that is highly water soluble, however, does not have this effect. A compound that has a water solubility greater than 25% prefers to partition in an aqueous phase, and a ratio of lipid:water greater than 90% is needed to encapsulate these compounds. The coacervation process, however, is generally limited to about 22% lipid. Thus, this technique is of only limited applicability for water soluble flavor or fragrance compounds.
Several techniques are known in the art for absorbing compounds into a microcapsule, such as cyclodextrin entrapment or silica plating. A drawback of the cyclodextrin entrapment technique is that the binding effect varies widely depending upon the particular flavor or fragrance compound. A drawback of the silica plating technique is that there is no barrier to protect the flavor or fragrance compound from evaporation. Thus, there is a need for an efficient method of absorbing the many types of flavor and fragrance compounds to the desired level of loading in an encapsulated oil. There is also a need for an efficient method of adsorbing flavor and fragrance compounds once they have been encapsulated.
SUMMARY OF THE INVENTION
This invention relates to a method of encapsulating a flavor or fragrance compound by controlled water transport of the compound into a capsule having an oil core. The method comprises preparing a microcapsule having a hydrogel shell and an oil core, and thereafter adding an amphiphilic flavor or fragrance compound in the presence of water to the microcapsule to transport the compound through the hydrogel shell and into the oil core. The compound is transported into the core by aqueous diffusion through the hydrogel shell. The oil core is retained in the hydrogel shell during the aqueous diffusion. A flavor or fragrance compound is thus encapsulated in the hydrogel shell containing the retained oil core.
The shell may consist of a carbohydrate or a protein, which may be crosslinked or non-crosslinked, or a synthetic polymer such as polyvinyl pyrollidone or methyl cellulose. The oil core may comprise, for example, vegetable oil, mineral oil, benzyl alcohol, or mixtures thereof. In a preferred embodiment, the oil is a short chain triglyceride of fractionated coconut oil. As more particularly defined hereinafter, "oil" is meant to include a wide range of substances that are dispersible in water due to their hydrophobic nature.
In an alternative embodiment of the invention, the microcapsule may be prepared in a dry form. An amphiphilic flavor or fragrance compound is added, in the presence of a controlled volume of water, to a substantially dry microcapsule having a hydrogel shell surrounding an oil core. The compound is transported through the hydrogel shell by aqueous diffusion into the oil core and is retained in the core. The microcapsule having the flavor or fragrance compound retained in the oil core is then dried.
In a preferred form of the invention, a flavor or fragrance compound is encapsulated by preparing a microcapsule of a coacervate of an oil core and a hydrogel shell, adding the flavor or fragrance compound in the presence of water to the microcapsule for transportation of the compound into the oil core, transporting the compound through the hydrogel shell by aqueous diffusion, and retaining the oil core in the hydrogel shell during the transportation to provide the encapsulated flavor or fragrance and retained oil core in the hydrogel shell.
The invention is also directed to the products produced by the methods of the invention.
One advantage of the invention is that the microcapsule may contain a concentration of the flavor or fragrance compound that heretofore has not been feasible. A second advantage is that the walls of the blank microcapsules have a substantially uniform thickness, strength, and resiliency. Another advantage is the increased yield of encapsulated flavor or fragrance, since essentially no flavor or fragrance compound is lost to the environment. Still another advantage is the economy in manufacturing the flavor or fragrance compounds of the invention, since the same technology is used for all flavors and fragrances.
The objectives and other advantages of this invention will be further understood with reference to the following detailed description and examples.
DETAILED DESCRIPTION
In a preferred practice of the invention, microcapsules containing a desired flavor or fragrance compound are formed by a coacervation process. In coacervation, there is separation of a colloid into a colloid-rich phase (the coacervate) and an aqueous solution of the coacervating agent (the equilibrium liquid), forming an oil coated with protein, carbohydrate, or polymeric droplets so as to suspend the oil in water. In the process, two lipid phases and one aqueous phase are ultimately absorbed into one lipid phase and one aqueous phase. The first lipid phase forms the microcapsule core. The core is surrounded by a hydrogel capsule, defined herein as a colloid in which the dispersed phase (colloid) has combined with the continuous phase (water) to produce a viscous jellylike product. The core consists of an oil which is a term used herein to define a wide range of substances that are quite different in their chemical nature. Oils may be classified by their type and function and encompass mineral oils (petroleum or petroleum-derived), vegetable oils (chiefly from seeds and nuts), animal oils (usually occurring as fats; the liquid types include fish oils), essential oils (complex volatile liquids derived from flowers, stems, leaves, and often the entire plant), and edible oils (chiefly vegetable oils as well as some special fish oils). Oils derived from living organisms are chemically identical with fats, the only difference being one of consistency at room temperature. In one embodiment, the oil may be mineral oil, vegetable oil, or benzyl alcohol. In a preferred embodiment, the oil is a short chain triglyceride of fractionated coconut oil, available under the tradenames Migylol® (Huls Corp., Piscataway, N.J.) or Captex® (Abitec Corp., Janesville, Wis.). The hydrogel shell may be either carbohydrate, protein, or a synthetic polymer such as polyvinyl pyrollidone or methyl cellulose. In a preferred embodiment, the oil is Migylol® or Captex® and the shell is gelatin. The second lipid phase is the desired flavor or fragrance compound, which is to some extent both water-soluble and lipid-soluble, that is, it is amphiphilic, which is the term used herein to define its dual solubility properties. The aqueous phase is used to transport, by partition coefficient equilibrium, the slightly water soluble flavor or fragrance compound into the oil core of the microcapsule by aqueous diffusion. Equilibrium dynamics continue until the three phases (two lipid and one aqueous) are absorbed into two phases (one lipid and one aqueous).
For some water soluble compounds, less water is required for absorption or partitioning into the oil phase. Conversely, for some highly lipid soluble compounds, more water may be required for partitioning into the oil phase. Thus, by transiently varying the amount of water that is available to a compound, taking into account the compound's partition coefficient, a compound may be absorbed through the hydrogel shell into an oil.
Adsorption of the compound in the oil can be controlled. Dehydration of the microcapsule or crosslinking of the capsule shell locks the flavor or fragrance compound inside the microcapsule. In dehydration, a substantial volume of the water is removed from the capsule, thereby reducing the loss of the partially water-soluble flavor or fragrance compound from the oil core into an aqueous environment. Alternatively, crosslinking of the hydrogel shell of the coacervate renders the encapsulated oil thermostable, since a capsule containing crosslinks is a stable structure. The use of known chemical crosslinking agents, such as formaldehyde or glutaraldehyde, to irreversibly crosslink the oil-containing capsule is known. Other crosslinking agents such as tannic acid (tannin) or potassium aluminum sulfate (alum) are similarly known. An optional capsule hardening step, as disclosed in U.S. Pat. Nos. 2,800,457 and 2,800,458, consists of adjusting a suspension of capsular material to pH 9 to 11, cooling to 0° C. to 5° C., and adding formaldehyde. Formaldehyde and glutaraldehyde are also effective chemical crosslinking agents. For the food industry and the cosmetic/toiletry industries, suitable cross-linking agents may be selected depending upon the specific application.
Certain naturally-occurring enzymes are also good cross-linking agents. Crosslinking using enzymes, such as transglutaminase, is disclosed in co-pending application Ser. No. 08/791,953 entitled Enzymatically Protein-Encapsulating Oil Particles by Complex Coacervation, which is hereby incorporated by reference in its entirety. Enzymes work by catalyzing the formation of bonds between certain amino acid side chains in proteins. In addition, because the enzymes are naturally occurring, encapsulated oils that are enzymatically crosslinked do not suffer from the problems inherent with formaldehyde and glutaraldehyde crosslinking, and hence may be ingested or applied without the concern of toxicity of the crosslinking agent. Because crosslinking is a enzyme catalyzed reaction, however, the proper environmental conditions must exist for optimum enzyme activity.
For compounds with high water solubility, defined herein as at least about 20% water soluble, it is preferable to concentrate the microcapsule to 55% solids or to start with dry microcapsules and gravimetrically add water and compound to get the desired results. For compounds with low water solubility, defined herein as less than about 20% water soluble, a hydrated microcapsule preparation may be used.
EXAMPLE 1
Blank capsules that are hydrated are prepared by pre-warming deionized water to 50° C.±2° C. A gum solution is prepared by vigorously agitating prewarmed deionized water (87.2018 g), carboxymethyl cellulose, sodium salt (1.8447 g), and gum arabic FCC powder SP Dri (0.1845 g). The solution is mixed until the solids are completely dissolved, then the solution is cooled to about 35° C. to about 40° C. A gelatin solution is prepared by vigorously agitating prewarmed deionized water (163.0453 g) and 250 Bloom type A gelatin (18.4461 g) in a preemulsion tank until the gelatin is completely dissolved, then the solution is cooled to about 35° C. to about 40° C. Without agitation, the gum solution is added to the gelatin solution in the preemulsion tank and the foam is allowed to dissipate for about 15-20 min. The pH is adjusted to about 5.5 with either a dilute sodium hydroxide solution (50% w/w) or a dilute citric acid solution (50% w/w).
Vegetable oil (180.02 g of Captex® 355 mixed triglycerides or Migylol®) is added with slow agitation, avoiding pooling of the oil. The capsule size is adjusted to about 100 microns to about 400 microns and the size is verified microscopically. The solution is slowly cooled at about 1° C. per 5 min until the solution reaches about 28° C. If the capsule walls are intact, as determined by microscopic examination of capsules showing uniform deposition of protein with no free protein floating in the water phase, the solution may be quickly cooled to about 10° C. If the capsule walls are thin, as determined by microscopic examination of capsules showing nonuniform deposition of protein and free protein floating in the water phase, the solution is reheated to about 32° C. to about 33° C. The solution is mixed at about 5° C. to about 10° C. for 1 h. The solution is then heated to about 15° C. to about 20° C. Fifty percent glutaraldehyde is added and allowed to mix for about 16 h. Agitation is then discontinued and the capsules are allowed to separate by flotation. Approximately 48% to 50% (approximately 379 lbs to 395 lbs) of water is drained from the bottom of the tank into a separate vessel. If capsules are present in the drained liquid, draining is stopped and agitation is begun to resuspend the separated capsules into solution. The separation step is then repeated. Once separation is complete, agitation is again begun in order to resuspend the capsules into solution. Sodium benzoate (10% w/w) is added with thorough mixing. If necessary, citric acid is added to adjust the pH to less than 4.0.
Blank capsules, defined herein as encapsulated oil with no flavor or fragrance value, that are dry are prepared by the following method. A syloid solution is prepared by mixing a silica compound syloid 244 grade 68 powder (15.9497 g) with deionized water (143.5477 g) until the powder is completely dispersed and no lumps are present. The flavor is mechanically mixed until smooth, then the syloid solution is mixed with the flavor until it is completely dispersed with no lumps, thinning out after about 30 min of stirring. The product is concentrated by centrifugation to about 50% or more solids. The material is then dried in either a vacuum oven dryer at about 80° C. or in a fluid bed dryer at about 70° C.
The dry crosslinked capsules (400 g) are placed in a stainless steel mixing bowl (Hobart Lab Scale Mixer). The desired neat flavor (428.6 g) is mixed with deionized water (171.4 g) on a magnetic stirrer for 5 min. The dry capsules are mixed with the water/flavor mixture on the Hobart Mixer at power level 1-2 for 5 min. The mixture is poured into a plastic storage container, using a rubber spatula to scrap the sides of the mixing bowl, and the container is closed. The mixture is allowed to incubate for 24 h for flavor absorption before the product is used.
EXAMPLE 2
Blank capsules that are hydrated are prepared by pre-warming deionized water to 50° C.±2° C. A gum solution is prepared by vigorously agitating prewarmed deionized water (87.2018 g), carboxymethyl cellulose, sodium salt (1.8447 g), and gum arabic FCC powder SP Dri (0.1845 g). The solution is mixed until the solids are completely dissolved, then the solution is cooled to about 35° C. to about 40° C. A gelatin solution is prepared by vigorously agitating prewarmed deionized water (163.0453 g) and 250 Bloom type A gelatin (18.4461 g) in a preemulsion tank until the gelatin is completely dissolved, then the solution is cooled to about 35° C. to about 40° C. Without agitation, the gum solution is added to the gelatin solution in the preemulsion tank and the foam is allowed to dissipate for about 15-20 min. The pH is adjusted to about 5.5 with either a dilute sodium hydroxide solution (50% w/w) or a dilute citric acid solution (50% w/w).
Vegetable oil (180.02 g of Captex® 355 mixed triglycerides or Migylol®) is added with slow agitation, avoiding pooling of the oil. The capsule size is adjusted to about 100 microns to about 400 microns and the size is verified microscopically. The solution is slowly cooled at about 1° C. per 5 min until the solution reaches about 28° C. If the capsule walls are intact, as determined by microscopic examination of capsules showing uniform deposition of protein with no free protein floating in the water phase, the solution may be quickly cooled to about 10° C. If the capsule walls are thin, as determined by microscopic examination of the capsules showing nonuniform protein deposition and free protein in the water phase, the solution is reheated to about 32° C. to about 33° C. The solution is mixed at about 5° C. to about 10° C. for 16 h, then agitation is discontinued and the capsules are allowed to separate by flotation. Approximately 48% to 50% (approximately 379 lbs to 395 lbs) of water is drained from the bottom of the tank into a separate vessel. If capsules are present in the drained liquid, draining is stopped and agitation is begun to resuspend the separated capsules into solution. The separation step is then repeated. Once separation is complete, agitation is again begun in order to resuspend the capsules into solution. Sodium benzoate (10% w/w) is added with thorough mixing. If necessary, citric acid is added to adjust the pH to less than 4.0. The capsules are stored at about 5° C. to about 10° C.
The hydrated uncrosslinked beads (815.20 g) are added to a glass reactor at about 5° C. to about 10° C. Stirring at about 95-100 rpm is begun while maintaining the temperature at about 5° C. to about 10° C. Neat flavor or fragrance (181.8 g) is added to the glass reactor. The mixture is stirred for about 2 h at about 5° C. to about 10° C. to allow the flavor or fragrance to absorb into the capsules. Fifty percent glutaraldehyde (3.0 g) is then added and allowed to mix at about 15° C. to about 20° C. for 16 h. Sodium benzoate (10.25 g of a 10% solution) is added to the reactor. Citric acid (20%) is added to adjust the pH of the solution to 3.9. The capsules are stabilized by adding a well-mixed xanthan gum/propylene glycol mixture (1 part xanthan to 2 parts propylene glycol). The mixture is stirred for about 30 min until the capsules are stabilized. Once the capsules are stabilized, they are ready for use.
EXAMPLE 3
Sodium alginate (8.22 g, type FD 155, Grinsted Corp.) was dissolved in deionized water (300 g). The solution was stirred until homogeneous. Microcapsules (3.75 g) were added with stirring until a homogeneous phase formed. Miglyol® (99.9 g) was then added with vigorous stirring to form an oil-in-water emulsion. The emulsion was fed through a vibrating needle (1.22 mm internal diameter) that was positioned about one inch above the lowest point of an eddy generated in a glass beaker by vigorous stirring of a 4% w/w aqueous CaCl 2 solution (150 ml). The flow rate of the emulsion through the needle was adjusted to prevent formation of a jet. Emulsion droplets, upon entering the CaCl 2 solution, immediately gelled, yielding particles of about 800 μm diameter. After the emulsion was added, the slurry of beads was permitted to stand for about 30 min to allow migration of calcium ions into the microcapsules. The microcapsules were dewatered at room temperature either by centrifugation or by vacuum filtration, and were subsequently dried by techniques known in the art such as vacuum oven drying or fluid bed drying.
The resulting microcapsules had a slight tendency to stick together due to the presence of some surface oil. A free-flowing, dry alginate-encapsulated flavor or fragrance compound was obtained by mixing the microcapsules (about 58%) and water (about 7%) with the desired flavor or fragrance compound (about 35%). The optimal absorption time is between about one hour and ten hours, depending upon the partition coefficient of the particular flavor or fragrance compound.
It should be understood that the embodiments of the present invention shown and described in the specification are only preferred embodiments of the inventors who are skilled in the art and are not limiting in any way. Therefore, various changes, modifications or alterations to these embodiments may be made or resorted to without departing from the spirit of the invention and the scope of the following claims.
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A method of encapsulating an amphiphilic flavor or fragrance compound into a microcapsule having a hydrogel shell and an oil core. The flavor or fragrance compound is transported into and solubilized in the core by partition coefficient equilibrium using water in the capsule wall to transport the compound into the core. Microcapsules made by the method of the invention may have a wall thickness and contain a high concentration of the flavor or fragrance compound that has not previously been feasible.
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FIELD OF THE INVENTION
[0001] The present invention relates to new amino acid diamides in non α position which are useful as adjuvants for administration of biological active ingredients. The compounds under the invention facilitate the oral, intraduodenal, intracolonic and pulmonary administration of heparin, low-molecular-weight heparins, very-low-molecular-weight heparins, and other glycosaminoglycans and derivatives.
BACKGROUND OF THE INVENTION
[0002] Heparin is currently used in parenteral administration for the prevention and treatment of deep venous thrombosis. Heparin and related derivatives are ineffective or are destroyed in the gastrointestinal tract by acid or enzymatic hydrolysis. In addition, the size and ionic charge of the molecules could prevent absorption.
[0003] Various adjuvants (for example, non-ionic surfactants) have been used to improve the oral absorption of heparin. Recently, modified amino acids have been used to facilitate the administration of various biological agents, in particular heparin (WO 98/34632, WO 01/51454, WO 97/36480).
[0004] These compounds are essentially derived from 4-amino-phenylbutyric acid:
and various amides such as:
[0005] In particular, the following derivatives
Primarily those derivatives relative to n=2 and n=5 (WO 97/36480) are claimed as agents that facilitate the oral absorption of biological products.
DESCRIPTION OF THE INVENTION
[0006] In the framework of its research on the oral absorption of heparin, the applicant has discovered a new family of chemical products that facilitate and considerably increase the oral absorption of heparin and its low-molecular-weight derivatives, particularly by colonic administration.
[0007] These products have the following structure
where: n=2 to 8
wherein R 1 is selected from amongst the group consisting of functional groups alkyl, halogen, NO 2 , OH, OCH 3 either alone or associated and R 2 is selected from the group consisting of functional groups H, alkyl, halogen, NO 2 , OH, OCH 3 .
[0009] These products are new. The research conducted by the applicant has demonstrated the originality of structure. In effect, the applicant has been able to show that the above mentioned products, structure C, n=3 (example 1) and n=5 (example 2), synthesised by the applicant have no effect on colonic absorption of a low-molecular-weight heparin (bemiparin) in the rat. Likewise, the products that have the structure D, n=3 (example 3)
synthesised by the applicant have no effect on the colonic absorption of bemiparin (see Table 1).
[0010] Table 1 shows the anti-Xa activity/ml in plasma after intracolonic administration in rat of Bemiparin and of the association of Bemiparin along with compounds from the examples 1, 2 and 3, as shown therein:
TABLE 1 Dosage Post-administration time (h) Treatment Admin, route (mg/kg) 0.5 2 4 Bemiparin Intracolonic 30 0.103 0.222 0.345 Bemi. + ex. 1 Intracolonic 30 + 30 0.299 0.196 0.147 Bemi. + ex. 2 Intracolonic 30 + 30 0.367 0.193 0.111 Bemi. + ex. 3 Intracolonic 30 + 30 0.520 0.316 0.240
These results tend to show the importance of the hydrogen bond between the O and H atoms of the invention products.
[0011] Another characteristic of the invention relates to the importance of the nature and position of the R 1 substituent as well as the chain length (n value).
[0012] The applicant has also discovered that the derivatives that have the Cl or NO 2 substituents in position 3 are at least as active as the derivatives that have an OH in position 1.
[0013] Among the invention products, the preferred compounds are those that correspond to n=3 and to the OH (example 4), Cl (example 17), NO 2 (example 11) substituents.
[0014] The invention products are usable in the form of an acid or in the form of a soluble salt, biologically acceptable, or of a pharmaceutical composition containing a heparin or a heparin derivative (ester, amide, oligosaccharides, etc.) as well as an adjuvant known for its favourable action (polyethylene glycol, alginate, chitosan and derivatives, propylene glycol, carbopol, etc.).
[0015] One of the preferred compositions consists of associating one of the products described above with a low-molecular-weight heparin such as bemiparin for an oral use in the prevention and treatment of venous and arterial thrombosis.
[0016] Another application of the invention products consists of associating them with any non-anticoagulant derivative of heparin for an oral utilization in conditions such as inflammation, allergy and cancer.
[0017] In general, the invention products enhance the oral absorption, particularly by the colonic route, of glycosaminoglycans and glycosaminoglycan oligosaccharides.
[0018] The properties of the invention products have been investigated in an experimental model described below that consists of measuring the intracolonic absorption in the rat of a low-molecular-weight heparin, bemiparin, with a mean molecular mass of around 3,500 daltons and an anti-Xa activity of around 100 units/mg.
[0019] The results obtained show, in particular for the products of examples 4 (see FIG. 1 ), 11 and 17 (see FIG. 2 ), a strong increase in the absorption of bemiparin measured by the plasma anti-Xa activity.
[0020] FIG. 1 shows the intracolonic absorption in the rat of bemiparin and of the compounds of examples 4, 5 and 9, which are shown below.
[0021] FIG. 2 shows the intracolonic absorption in the rat of the compounds of examples 10, 11 and 17, which are shown below.
[0022] Another advantage of the invention products and of their interest as agents that increase the oral absorption of oligosaccharides derived from heparin has been demonstrated by the study of the intracolonic absorption of a very-low-molecular-weight heparin, RO-14, (2,500 daltons, 80 to 100 units anti-Xa/mg). The pharmaceutical composition RO-14+product of example 4 (see FIG. 3 ) shows a high, long-lasting anti-Xa activity.
[0023] FIG. 3 shows the intracolonic absorption in the rat of the association of the pharmaceutical composition RO-14 with the product of example 4.
[0024] A series of examples is provided below in order to clarify the invention, without limiting the scope of the invention. These examples describe the procedure for the preparation of compounds 1 to 22 indicated below, as well as their intracolonic absorption-enhancing effect of the low-molecular-weight heparin, Bemiparin.
EXAMPLE 1
4-[4-(hydroxybenzoylamino)benzoylamino]butanoic acid. (compound 1)
[0025]
[0026] To a solution of 4.41 g (18.69 mmol) of methyl 4-(4-aminobenzoylamino)butanoate dissolved in 80 ml of ethyl acetate, very slowly add 2.49 g (15.97 mmol) of 2-hydroxybenzoyl chloride dissolved in 10 ml of ethyl acetate. Then add 1.61 g (15.97 mmol) of triethylamine and keep the reaction mixture at room temperature for 24 hours. Eliminate the solvent at low pressure, add 40 ml of 10% NaOH to the crude product and continue stirring the mixture until the solid has completely disappeared. Immediately acidify with concentrated hydrochloric acid, filter the resulting solid and wash several times with water. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 1.48 g (27%) of 4-[4-(2-hydroxybenzoylamino)benzoylamino]butanoic acid as a white solid.
[0027] M.P.: 211-213° C.
[0028] IR (KBr): ν3360, 2970, 2680, 1700, 1665, 1620, 1540, 1510, 855, 770, 750, 695 cm −1
[0029] 1 H NMR (DMSO, 400 MHz): δ 1.75 (m, 2H, —CH 2 —), 2.27 (t, 2H, J=7.2 Hz, —CH 2 —CO—), 3.27 (m, 2H, —CH 2 —N—), 6.97 (m, 2H, aromatic), 7.43 (m, 1H, aromatic), 7.79 (d, 2H, J=8.5 Hz, aromatic), 7.85 (d, 2H, J=8.5 Hz, aromatic), 7.94 (m, 1H, aromatic), 8.39 (t, 1H, J=5.3 Hz, — NH —CH 2 —), 10.51 (s, 1H, —NH-Ph) ppm
[0030] 13 C NMR (DMSO, 100 MHz): 24.6, 31.6, 38.6, 117.2, 117.9, 119.1, 119.8, 127.9, 129.3, 129.9, 133.7, 140.7, 158.0, 165.6, 166.4, 174.2 ppm
[0031] MS m/z (%): 342 (M + , 4), 324 (5), 239 (19), 204 (18), 168 (21), 120 (100), 92 (19), 65 (33)
[0032] Elemental analysis of C 18 H 18 N 2 O 5 Calculated: % C=63.15; % H=5.30; % N=8.18. Found: % C=63.10; % H=5.32; % N=8.04.
EXAMPLE 2
6-[4-(2-hydroxybenzoylamino)benzoylamino]hexanoic acid. (compound 2)
[0033]
[0034] To a solution of 2.81 g (10.64 mmol) of methyl 6-(4-aminobenzoylamino)hexanoate dissolved in 50 ml of acetonitrile, very slowly add 1.42 g (9.10 mmol) of 2-hydroxybenzoyl chloride dissolved in 5 ml of acetonitrile. Then add 0.92 g (9.10 mmol) of triethylamine and keep the reaction mixture at room temperature for 24 hours. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the solid has completely disappeared. Immediately acidify with concentrated hydrochloric acid, filter the resulting solid and wash several times with water. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 1.11 g (33%) of 6-[4-(2-hydroxybenzoylamino)benzoylamino]hexanoic acid as a white solid.
[0035] M.P.: 201-203° C.
[0036] IR(KBr): ν3330, 3050, 2950, 2680, 2570, 1700, 1675, 1600, 1540, 855, 770, 750 cm −1
[0037] 1 H NMR (DMSO, 400 MHz): δ 1.32 (m, 2H, —CH 2 — CH 2 —CH 2 —), 1.51 (m, 4H, — CH 2 —CH 2 — CH 2 —), 2.20 (t, 2H, J=7.3 Hz, —CH 2 —CO—), 3.23 (m, 2H, —CH 2 —N—), 6.97 (m, 2H, aromatic), 7.43 (m, 1H, aromatic), 7.78 (d, 2H, J=8.5 Hz, aromatic), 7.84 (d, 2H, J=8.5 Hz, aromatic), 7.93 (m, 1H, aromatic), 8.35 (t, 1H, J=5.1 Hz, — NH —CH 2 —), 10.51 (s, 1H, — NH -Ph), 11.62 (s, 1H, —OH), 11.95 (s, 1H, —COOH) ppm
[0038] 13 C NMR (DMSO, 100 MHz): δ 14.2, 24.5, 25.5, 28.6, 34.1, 60.3, 68.5, 114.3, 125.9, 164.1, 173.5 ppm
[0039] MS m/z (%) 263 (M-18, 3), 236 (4), 218 (2), 172 (5), 143 (20), 115 (16), 97 (49), 69 (100), 55 (49), 41 (65)
[0040] Elemental analysis of C 20 H 22 N 2 O 5 Calculated: % C=64.85; % H=5.99; % N=7.56. Found: % C=64.51; % H=5.86; % N=7.45.
EXAMPLE 3
4-[3-(2-hydroxybenzoylamino)benzoylamino]butanoic acid. (compound 3)
[0041]
[0042] To a solution of 2.60 g (11.00 mmol) of methyl 4-(3-aminobenzoylamino)butanoate dissolved in 25 ml of ethyl acetate, very slowly add 1.40 g (10.00 mmol) of 2-hydroxybenzoyl chloride dissolved in 5 ml of ethyl acetate. Then add 1.00 g (10.00 mmol) of Et 3 N (triethylamine) and keep the reaction mixture at room temperature for 24 hours. Eliminate the solvent at low pressure, add 40 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 1.60 g (48%) of 4-[3-(2-hydroxybenzoylamino) benzoylamino]butanoic acid as a white solid.
[0043] M.P.: 172-174° C.
[0044] IR(ATR): ν 3291, 2940, 1714, 1611, 1551, 1455, 1335, 1232, 1214, 878, 817, 735 cm −1
[0045] 1 H NMR (DMSO, 400 MHz): δ 1.77 (q, 2H, J=7.0 Hz, —CH 2 —), 2.28 (t, 2H, J=7.4 Hz, —CH 2 —CO—), 3.28 (m, 2H, —CH 2 —N—), 6.97 (m, 2H, aromatic), 7.43 (m, 2H, aromatic), 7.59 (m, 1H, aromatic), 7.87 (m, 1H, aromatic), 7.98 (m, 1H, aromatic) 8.12 (m, 1H, aromatic), 8.50 (t, 1H, J=5.0 Hz, — NH —CH 2 —), 10.50 (s,1H, —NH—) ppm
[0046] 13 C NMR (DMSO, 100 MHz): δ 24.5, 31.2, 38.7, 117.3, 117.4, 119.1, 120.2, 122.7, 123.5, 128.6, 129.1, 133.8, 135.4, 138.2, 158.5, 166.1, 166.7, 174.2 ppm
[0047] MS m/z (%): 238 (M + −104, 61), 210 (3), 186 (2), 160 (3), 137 (9), 119 (100), 120 (30), 92 (50), 91 (12), 65 (31)
[0048] Elemental analysis of C 18 H 18 N 2 O 5 Calculated: % C=63.14; % H=5.31; % N=8.18. Found: % C=63.01; % H=5.23; % N=8.21.
EXAMPLE 4
4-[2-(2-hydroxybenzoylamino)benzoylamino]butanoic acid. (compound 4)
[0049]
[0050] To a suspension of 20.36 g (91.71 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 200 ml of dry methylene chloride, add 42.33 g (391.92 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 11.87 g (117.57 mmol) of triethylamine and a solution of 15.52 g (78.38 mmol) of acetylsalicyloyl chloride dissolved in 20 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 200 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 21.66 g (81%) of 4-[2-(2-hydroxy-benzoylamino)benzoylamino]butanoic acid as a white solid.
[0051] M.P.: 173-174° C.
[0052] IR(ATR): ν 3322, 2925, 2852, 1688, 1652, 1633, 1597, 1529, 1448, 1260, 1228, 756 cm −1
[0053] 1 H NMR (DMSO, 400 MHz): δ1.76 (q, 2H, J=7.0 Hz, —CH 2 —), 2.28 (t, 2H, J=7.3 Hz, —CH 2 —CO—), 3.27 (m, 2H, —CH 2 —N—), 6.96 (m, 2H, aromatic), 7.20 (m, 1H, aromatic), 7.42 (m, 1H, aromatic), 7.50 (m, 1H, aromatic), 7.68 (m, 1H, aromatic), 7.83 (m, 1H, aromatic) 8.48 (m, 1H, aromatic), 8.50 (t, 1H, J=5.0 Hz, — NH —CH 2 —), 11.62 (S broad , 1H, —OH), 12.03 (S broad , 1H, —COOH), 12.19 (s, 1H, —NH-Ph) ppm
[0054] 13 C NMR (DMSO, 200 MHz): δ 24.2, 31.1, 38.9, 117.2, 117.9, 119.3, 121.7, 123.1, 123.3, 128.1, 129.2, 131.3, 133.7, 137.8, 158.1, 165.5, 168.1, 174.2 ppm
[0055] MS m/z (%): 342 (M + , 5), 265 (4), 239 (100), 222 (11), 121 (50), 120 (64), 119 (62), 92 (54), 77 (10), 65 (53), 39 (39)
[0056] Elemental analysis of C 18 H 18 N 2 O 5 Calculated: % C=63.15; % H=5.30; % N=8.18. Found: % C=63.15; % H=5.38; % N=8.15.
EXAMPLE 5
5-[2-(2-hydroxybenzoylamino)benzoylamino]pentanoic acid. (compound 5)
[0057]
[0058] To a suspension of 1.61 g (6.81 mmol) of 5-(2-aminobenzoylamino)pentanoic acid in 20 ml of dry methylene chloride, add 1.41 g (11.94 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 0.88 g (8.73 mmol) of triethylamine and a solution of 1.15 g (5.82 mmol) of acetylsalicyloyl chloride dissolved in 5 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 20 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 1.26 g (61%) of 5-[2-(2-hydroxybenzoylamino) benzoyl-amino]pentanoic acid as a white solid.
[0059] M.P.: 168-170° C.
[0060] IR(ATR): ν 3310, 1698, 1648, 1626, 1597, 1521, 1269, 1223, 1139, 746 cm −1
[0061] 1 H NMR (400 MHz, DMSO): δ1.54 (m, 4H, —CH 2 — CH 2 —CH 2 —CH 2 —), 2.21 (t, 2H, J=7.2 Hz, —CH 2 —CO), 3.26 (m, 2H, —CH 2 —N—), 6.97 (m, 2H, aromatic), 7.18 (m, 1H, aromatic), 7.40 (m, 1H, aromatic), 7.51 (m, 1H, aromatic), 7.67 (m, 1H, aromatic), 7.84 (m, 1H, aromatic), 8.47 (m, 1H, aromatic), 8.72 (t, 1H, J=5.4 Hz, — NH —CH 2 —), 11.62 (s, 1H, —OH), 11.98 (s, 1H, —COOH), 12.18 (s, 1H, —NH-Ph) ppm
[0062] 13 C NMR (200 MHz, DMSO): δ 22.0, 28.3, 33.3, 38.9, 117.2, 118.0, 119.3, 121.74, 123.2, 123.5, 128.0, 129.3, 131.3, 133.7, 137.8, 158.0, 165.5, 168.0, 174.4 ppm
[0063] MS m/z (%): 356 (M + , 1), 337 (9), 239 (72), 119 (100), 99 (18), 92 (59), 77 (15), 65 (48), 41 (25)
[0064] Elemental analysis of C 19 H 20 N 2 O 5 Calculated: % C=64.04; % H=5.66; % N=7.86. Found: % C=63.90; % H=5.69; % N=7.75.
EXAMPLE 6
8-[2-(2-hydroxybenzoylamino)benzoylamino]octanoic acid. (compound 6)
[0065]
[0066] To a suspension of 2.00 g (7.20 mmol) of 8-(2-aminobenzoylamino)octanoic acid in 25 ml of dry methylene chloride, add 1.36 g (12.60 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 0.93 g (9.22 mmol) of triethylamine and a solution of 1.21 g (6.15 mmol) of acetylsalicyloyl chloride dissolved in 5 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 20 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 1.41 g (58%) of 8-[2-(2-hydroxybenzoylamino)benzoylamino]octanoic acid as a white solid.
[0067] M.P.: 124-125° C.
[0068] IR(ATR): ν 3310, 2931, 2855, 1698, 1654, 1627, 1585, 1526, 1495, 1448, 1409, 1361, 1315, 1268, 1222, 1196, 1168 cm −1
[0069] 1 H NMR (400 MHz, DMSO): δ1.25 (m, 6H, —CH 2 —CH 2 — CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —), 1.46 (m, 4H, —CH 2 — CH 2 —CH 2 —CH 2 —CH 2 — CH 2 CH 2 —), 2.14 (t, 2H, J=7.5 Hz, —CH 2 —CO), 3.23 (m, 2H, —CH 2 —N—), 6.95 (m, 2H, aromatic), 7.18 (m, 1H, aromatic), 7.41 (m, 1H, aromatic), 7.50 (m, 1H, aromatic), 7.65 (m, 1H, aromatic), 7.84 (m, 1H, aromatic), 8.44 (m, 1H, aromatic), 8.67 (t, 1H, J=5.7 Hz, — NH —CH 2 —), 11.61 (s, 1H, —OH), 11.90 (s, 1H, —COOH), 12.13 (s, 1H, —NH-Ph) ppm
[0070] 13 C NMR (200 MHz, DMSO): δ24.5, 26.4, 28.50, 28.52, 28.8, 33.6, 39.2, 117.2, 117.9, 119.3, 121.8, 123.2, 123.8, 128.0, 129.2, 131.2, 133.7, 137.7, 158.1, 165.5, 167.9, 174.5 ppm
[0071] MS m/z (%): 398 (M + , 1), 379 (3), 351 (2), 278 (5), 251 (6), 239 (94), 197 (9), 137 (11), 119 (100), 100 (17), 92 (51), 77 (8), 65 (37), 41 (20)
[0072] Elemental analysis of C 19 H 20 N 2 O 5 Calculated: % C=66.32; % H=6.58, % N=7.03. Found: % C=66.03; % H=6.47; % N=7.05.
EXAMPLE 7
6-[2-(2-hydroxybenzoylamino)benzoylamino]hexanoic acid. (compound 7)
[0073]
[0074] To a suspension of 0.30 g (1.20 mmol) of 6-(2-aminobenzoylamino)hexanoic acid in 5 ml of dry methylene chloride, add 0.23 g (2.10 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 0.15 g (1.53 mmol) of triethylamine and a solution of 0.20 g (2.05 mmol) of 2-acetylsalicyloyl chloride dissolved in 5 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 10 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 0.24 g (62%) of 6-[2-(2-hydroxybenzoylamino)benzoylamino]hexanoic as a white solid.
[0075] M.P.: 165-167° C.
[0076] IR(ATR): ν 3348, 2923, 2853, 1688, 1595, 1523, 1493, 1414, 1360, 1272, 903, 815, 759 cm −1
[0077] 1 H-NMR (400 MHz, DMSO): δ1.31 (m, 2H, —CH 2 — CH 2 —CH 2 —), 1.51 (m, 4H, —CH 2 — CH 2 —CH 2 — CH 2 CH 2 —), 2.17 (t, 2H, J=7.4 Hz, —CH 2 —CO—), 3.24 (m, 2H, —CH 2 —NH—), 6.96 (m, 2H, aromatic), 7.18 (m, 1H, aromatic), 7.41 (m, 1H, aromatic), 7.50 (m, 1H, aromatic), 7.66 (m, 1H, aromatic), 7.84 (m, 1H, aromatic), 8.46 (m, 1H, aromatic), 8.69 (S broad , 1H, — NH —CH 2 —), 11.61 (s, 1H, —OH), 11.93 (s, 1H, —COOH), 12.16 (s, 1H, —NH-Ph) ppm
[0078] 13 C NMR (200 MHz, DMSO): δ 24.2, 26.0, 28.5, 33.6, 39.1, 117.2, 118.0, 119.3, 121.8, 123.2, 123.7, 128.0, 129.3, 131.2, 133.7, 137.7, 158.0, 165.4, 167.9, 174.4, ppm
[0079] MS m/z (%): 352 (M + −18, 3), 351 (4), 265 (3), 251 (9), 239 (56), 211 (6), 132 (7), 119 (100), 102 (5), 92 (62), 77 (15), 65 (52), 41 (26)
[0080] Elemental analysis of C 20 H 22 N 2 O 5 Calculated: % C=64.85; % H=5.99; % N=7.56. Found: % C=64.57; % H=5.93; % N=7.57.
EXAMPLE 8
4-[2-(2-nitrobenzoylamino)benzoylamino]butanoic acid. (compound 8).
[0081]
[0082] To a suspension of 3.90 g (17.50 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 40 ml of dry ethyl acetate, add 3.26 g (17.56 mmol) of 2-nitrobenzoyl chloride dissolved in 5 ml of dry ethyl acetate and 1.76 g of triethylamine. Allow the reaction mixture to stir for 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the solid has completely disappeared. Immediately acidify with concentrated HCl and extract the product with ethyl acetate. Eliminate the solvent at low pressure and recombine the crude product with dry ether, obtaining a white solid. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 3.34 g (51%) of 4-[2-(2-nitrobenzoylamino)benzoylamino]butanoic acid as a white solid.
[0083] M.P.: 142-144° C.
[0084] IR(ATR): ν 3348, 2923, 2853, 1688, 1595, 1523, 1493, 1414, 1360, 1272, 903, 815, 759 cm −1
[0085] 1 H-NMR (400 MHz, DMSO): δ1.73 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.26 (t, 2H, J=7.0 Hz, —CH 2 —CO—), 3.24 (m, 2H, —CH 2 —NH—), 7.24 (m, 1H, aromatic), 7.56 (m, 1H, aromatic), 7.80 (m, 4H, aromatic), 8.10 (m, 1H, aromatic), 8.38 (m, 1H, aromatic), 8.82 (S broad , 1H, — NH —CH 2 —), 12.02 (s, 1H, —COOH), 12.06 (s, 1H, —NH-Ph) ppm
[0086] 13 C NMR (200 MHz, DMSO): δ 24.1, 31.0, 38.6, 120.8, 121.6, 123.6, 124.6, 128.2, 128.3, 131.5, 131.98, 132.02, 134.1, 138.3, 147.1, 163.3, 168.1, 174.1 ppm
[0087] MS m/z (%): 371 ( + , 4), 353 (6), 268 (26), 236 (49), 208 (36), 150 (54), 134 (100), 120 (55), 119 (55), 104 (39), 90 (47), 76 (57), 44 (58)
[0088] Elemental analysis of C 18 H 17 N 3 O 6 Calculated: % C=58.22; % H=4.61; % N=11.32. Found: % C=58.15; % H=4.55; % N=11.35.
EXAMPLE 9
3-[2-(2-hydroxybenzoylamino)benzoylamino]propanoic acid. (compound 9)
[0089]
[0090] To a suspension of 0.5 g (2.40 mmol) of 3-(2-aminobenzoylamino)propanoic acid in 10 mL of dry methylene chloride, add 0.45 g (4.20 mmol) of trimethylsilyl chloride and allow the reaction to reflux under argon during 2 hours. Then place the flask in an ice bath and add 0.31 g (3.07 mmol) of triethylamine and a solution of 0.40 g (2.05 mmol) of 2-acetylsalicycoyl chloride dissolved in 5 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 0.37 g (56%) of 3-[2-(2-hydroxybenzoylamino)benzoylamino]propanoic acid as a white solid.
[0091] M.P.: 200-202° C.
[0092] IR(ATR): ν 3331, 3051, 2657, 1718, 1649, 1626, 1593, 1523, 1269, 1225, 904, 853, 749 cm −1
[0093] 1 H-NMR (400 MHz, DMSO): δ 2.52 (t, 2H, J=7.4 Hz, —CH 2 —CO—), 3.46 (m, 2H, —CH 2 —N—), 6.97 (m, 2H, aromatic), 7.18 (m, 1H, aromatic), 7.41 (m, 1H, aromatic), 7.51 (m, 1H, aromatic), 7.65 (m, 1H, aromatic), 7.85 (m, 1H, aromatic), 8.45 (m, 1H, aromatic), 8.79 (S broad , 1H, — NH —CH 2 —), 11.61 (s, 1H, —OH), 12.15 (s, 1H, —COOH), 12.25 (s, 1H, —NH-Ph), ppm
[0094] 13 C NMR (200 MHz, DMSO): δ 35.4, 35.5, 117.2, 118.02, 119.3, 121.7, 123.1, 123.2, 128.0, 129.4, 131.4, 131.7, 137.8, 157.9, 165.3, 168.1, 172.7 ppm
[0095] MS m/z (%): 328 (M + , 6), 293 (3), 250 (5), 239 (100), 208 (20), 119 (65), 92 (50), 65 (60), 44 (42)
[0096] Elemental analysis of C 17 H 16 N 2 O 5 Calculated: % C=62.19; % H=4.91; % N=8.53. Found: % C=61.82; % H=4.72; % N=8.39.
EXAMPLE 10
2-[2-(2-hydroxybenzoylamino)benzoylamino]ethanoic acid. (compound 10)
[0097]
[0098] To a suspension of 4.74 g (24.44 mmol) of 2-(2-aminobenzoylamino)ethanoic acid in 40 ml of dry methylene chloride, add 5.05 g (4.28 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 3.16 g (31.32 mmol) of triethylamine and a solution of 4.13 g (20.88 mmol) of acetylsalicyloyl chloride dissolved in 10 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 40 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 3.54 g (54%) of 2-[2-(2-hydroxybenzoylamino) benzoylamino]ethanoic acid as a white solid.
[0099] M.P.: 222-224° C.
[0100] IR(ATR): ν 3286, 2978, 1730, 1650, 1627, 1598, 1584, 1526, 1242, 900, 835, 752 cm −1
[0101] 1 H-NMR (400 MHz, DMSO): δ3.95 (d, 2H, J=4.9 Hz, —CH 2 —), 6.97 (m, 2H, aromatic), 7.21 (m, 1H, aromatic), 7.41 (m, 1H, aromatic), 7.55 (m, 1H, aromatic), 7.80 (m, 2H, aromatic), 8.52 (m, 2H, aromatic), 9.07 (S broad, 1 H, — NH —CH 2 —), 11.58 (s, 1H, —OH), 12.18 (s, 1H, —COOH), 12.70 (s, 1H, —NH-Ph) ppm
[0102] 13 C-NMR (200 MHz, DMSO): δ 41.2, 117.2, 118.0, 119.3, 121.8, 122.3, 123.2, 128.1, 129.3, 131.8, 133.7, 138.1, 157.9, 165.4, 168.4, 171.0 ppm.
[0103] MS m/z (%): 278 (M + −36, 16), 239 (37) 234 (17), 195 (14), 107 (9), 119 (100), 92 (36), 77 (22) 65 (28), 50 (19)
[0104] Elemental analysis of C 20 H 22 N 2 O 5 Calculated: % C=61.14; % H=4.49; % N=8.91. Found: % C=60.90; % H=4.42; % N=8.98.
EXAMPLE 11
4-[2-(2-hydroxy-4-nitrobenzoylamino)benzoylamino]butanoic acid. (compound 11)
[0105]
[0106] To a suspension of 1.00 g (4.50 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 ml of dry methylene chloride, add 4.50 g (38.50 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 0.58 g (5.70 mmol) of triethylamine and a solution of 0.77 g (38.50 mmol) of 2-hydroxy-4-nitrobenzoyl chloride dissolved in 10 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 0.50 g (34%) of 4-[2-(2-hydroxy-4-nitro-benzoylamino)benzoylamino]butanoic acid as a yellow solid.
[0107] M.P.: 209-211 C.
[0108] IR(ATR): ν 3378, 2939,.1702, 1592, 1520, 1449, 1420, 1347, 1326, 1300, 1259, 1232, 1215, 1162, 813, 748, 737 cm −1
[0109] 1 H-NMR (400 MHz, DMSO): δ1.75 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.28 (t, 1H, J=7.3 Hz, —CH 2 CO—), 3.26 (m, 2H, —CH 2 —N—), 7.20 (m, 1H, aromatic), 7.52 (m, 1H, aromatic), 7.66 (m, 1H, aromatic), 7.74 (m, 2H, aromatic), 8.10 (m, 1H, aromatic), 8.49 (m, 1H, aromatic), 8.71 (t, J=5.4 Hz, — NH —CH 2 —), 12.12 (s, 2H, —OH, —COOH), 12.30 (s, 1H, —NH) ppm
[0110] 13 C-NMR (200 MHz, DMSO): δ 24.2, 31.1, 38.7, 111.4, 113.6, 121.1, 123.5, 124.0, 125.4, 128.1, 131.2 132.1, 137.4, 149.9, 156.8, 162.5, 167.8, 174.2 ppm
[0111] MS m/z (%): 284 (M + −103, 55), 253 (4), 238 (16), 222 (1), 211 (2), 182 (8), 154 (9), 146 (13), 119 (90), 92 (47), 63 (48), 53 (21), 30 (100)
[0112] Elemental analysis of C 18 H 17 N 3 O 7 Calculated: % C=55.81; % H=4.42; % N=10.85. Found: % C=55.79; % H=4.44; % N=10.74.
EXAMPLE 12
4-[2-(2-hydroxy-5-nitrobenzoylamino)benzoylamino]butanoic acid. (compound 12)
[0113]
[0114] To a suspension of 1.00 g (4.50 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 ml of dry methylene chloride, add 4.50 g (38.50 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 0.58 g (5.70 mmol) of triethylamine and a solution of 0.77 g (38.50 mmol) of 2-hydroxy-5-nitrobenzoyl chloride dissolved in 10 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization in dioxane/H 2 O. This yields 0.99 g (67%) of 4-[2-(2-hydroxy-5-nitrobenzoylamino)benzoylamino]butanoic acid as a cream-coloured solid.
[0115] M.P.: 239-241° C.
[0116] IR(ATR): ν3315, 3079, 2626, 1695, 1651, 1631, 1584, 1373, 1334, 1218, 831, 756, 746 cm −1
[0117] 1 H-NMR (400 MHz, DMSO): δ1.75 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.28 (t, 1H, J=6.8 Hz, —CH 2 —CO—), 3.26 (m, 2H, —CH 2 —N—), 7.15 (m, 1H, aromatic), 7.18 (m, 1H, aromatic), 7.53 (m, 1H, aromatic), 7.65 (m, 1H, aromatic), 7.26 (m, 1H, aromatic), 8.45 (m, 1H, aromatic), 8.70 (m, J=5.4 Hz, — NH —CH 2 —), 8.76 (m, 1H, aromatic), 12.09 (s, 2H, —OH, —COOH), 12.90 (s, 1H, —NH) ppm
[0118] 13 C-NMR (200 MHz, DMSO): δ 24.2, 31.1, 38.7, 117.9, 119.8, 122.2, 123.5, 124.3, 127.2, 128.1, 128.5, 131.1, 137.3, 139.7, 162.0. 162.3, 167.8, 174.2 ppm
[0119] MS m/z (%): 369 (M + −18, 1), 352 (10), 335 (1), 311 (3), 296 (3), 284 (31), 253 (11), 237 (3), 209 (6), 166 (6), 137 (8), 119 (74), 92 (55), 63 (43), 42 (56), 41 (72), 30 (100)
[0120] Elemental analysis of C 18 H 17 N 3 O 7 Calculated: % C=55.81; % H=4.42; % N=10.85. Found: % C=55.89; % H=4.50; % N=10.80.
EXAMPLE 13
4-[2-(2-hydroxy-4-methoxybenzoylamino)benzoylamino]butanoic acid. (compound 13)
[0121]
[0122] To a suspension of 1.00 g (4.50 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 ml of dry methylene chloride, add 4.50 g (38.50 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 0.58 g (5.70 mmol) of triethylamine and a solution of 0.71 g (38.5 mmol) of 2-hydroxy-4-methoxybenzoyl chloride dissolved in 10 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 0.54 g (38%) of 4-[2-(2-hydroxy-4-methoxybenzoylamino)benzoylamino]butanoic acid as a white solid.
[0123] M.P.: 201-203° C.
[0124] IR(ATR): ν 3306, 2939, 1711, 1643, 1622, 1582, 1524, 1508, 1438, 1383, 1244, 1208, 1178, 1144, 964, 830, 751, 671 cm −1
[0125] 1 H-NMR (400 MHz, DMSO): δ 1.76 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.29 (t, 1H, J=7.3 Hz, —CH 2 —CO—), 3.29 (m, 2H, —CH 2 —), 3.78 (s, 3H, —CH 3 ), 6.48 (m, 1H, aromatic), 6.58 (m, 1H, aromatic), 7.17 (m, 1H, aromatic), 7.50 (m, 1H, aromatic), 7.71 (m, 1H, aromatic), 7.76 (m, 1H, aromatic), 8.45 (m, 1H, aromatic), 8.77 (t, J=5.4 Hz, — NH —CH 2 —),12.05 (s, 2H, —OH, —NH), 12.22 (s, 1H, —COOH) ppm
[0126] 13 C-NMR (200 MHz, DMSO): δ 24.2, 31.1, 38.7, 55.4, 101.3, 106.7, 109.9, 121.5, 122.6, 122.9, 128.1, 129.9, 131.5, 138.1, 160.9, 163.8, 166.0, 168.2, 174.2 ppm
[0127] MS m/z (%): 372 (M + , 3), 353 (2), 269 (84), 228 (16), 222 (17), 182 (4), 151 (100), 120 (58), 119 (59), 92 (47), 65 (24), 52 (12), 30 (53)
[0128] Elemental analysis of C 19 H 20 N 2 O 6 Calculated: % C=61.28; % H=5.41; % N=7.52. Found: % C=60.89; % H=5.37; % N=7.40.
EXAMPLE 14
4-[2-(2-hydroxy-5-methoxybenzoylamino)benzoylamino]butanoic acid. (compound 14)
[0129]
[0130] To a suspension of 1.00 g (4.50 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 ml of dry methylene chloride, add 4.50 g (38.50 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 0.58 g (5.70 mmol) of triethylamine and a solution of 0.71 g (38.5 mmol) of 2-hydroxy-5-methoxybenzoyl chloride dissolved in 10 mL of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 0.791 g (56%) of 4-[2-(2-hydroxy-5-methoxybenzoylamino)benzoylamino]butanoic acid as a cream-coloured solid.
[0131] M.P.: 191-193° C.
[0132] IR(ATR): ν 3330, 2877, 1702, 1593, 1523, 1494, 1473, 1449, 1419, 1356, 1328, 1306, 1266, 1205, 1188, 1174, 1047, 931, 792, 746, 687 cm −1
[0133] 1 H-NMR (400 MHz, DMSO): δ 1.76 (m, 2H, —CH 2 — CH 2 CH 2 —), 2.28 (t, 1H, J=7.3 Hz, —CH 2 —CO—), 3.27 (m, 2H, —CH 2 —), 3.73 (s, 3H, —CH 3 ), 6.91 (m, 1H, aromatic), 7.04 (m, 1H, aromatic), 7.18 (m, 1H, aromatic), 7.38 (m, 1H, aromatic), 7.50 (m, 1H, aromatic), 7.76 (m, 1H, aromatic), 8.46 (m, 1H, aromatic), 8.70 (t, J=5.4 Hz, — NH —CH 2 —), 11.10 (s, 1H, —OH), 12.03 (s, 1H, —NH), 12.09 (s, 1H, —COOH) ppm
[0134] 13 C-NMR (200 MHz, DMSO): δ 24.2, 31.1, 38.7, 55.4, 112.8, 118.1, 118.3, 120.5, 121.7, 123.1, 123.8, 128.0, 131.2, 137.7, 151.6, 151.9, 164.8, 168.0, 174.2 ppm
[0135] MS m/z (%): 372 (M + , 5), 353 (3), 269 (100), 254 (88), 198 (11), 150 (20), 120 (55), 119 (45), 92 (50), 79 (33), 65 (29), 52 (21), 30 (51)
[0136] Elemental analysis of C 19 H 20 N 2 O 6 Calculated: % C=61.28; % H=5.41; % N=7.52. Found: % C=61.21; % H=5.40; % N=7.47.
EXAMPLE 15
4-[2-(4-nitrobenzoylamino)benzoylamino]butanoic acid. (compound 15)
[0137]
[0138] To a suspension of 2.14 g (9.63 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 40 ml of dry methylene chloride, add 1.83 g (16.87 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 1.24 g (12.33 mmol) of triethylamine and a suspension of 1.53 g (8.22 mmol) of 4-nitrobenzoyl chloride in 10 ml of dry ethyl acetate. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization in dioxane/H 2 O . This yields 1.33 g (43%) of 4-[2-(4-nitrobenzoylamino) benzoylamino] butanoic acid as a cream-coloured solid.
[0139] M.P.: 206-208 C.
[0140] IR(ATR): ν 3282, 3090, 1731, 1655, 1626, 1597, 1558, 1517, 1444, 1417, 1399, 1350, 1326, 1297, 1258, 1227, 1166, 854, 836, 766, 715 cm −1 1 H-NMR (400 MHz, DMSO): δ 1.77 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.29 (t, 1H, J=7.3 Hz, —CH 2 —CO—), 3.31 (m, 2H, —CH 2 —N—), 7.24 (m, 1H, aromatic), 7.58 (m, 1H, aromatic), 7.85 (m, 1H, aromatic), 8.14 (d, 2H, J=8.7 Hz, aromatic), 8.42 (d, 2H, J=8.7 Hz, aromatic), 8.58 (m, 1H, aromatic), 8.46 (m, 1H, aromatic), 8.91 (t, J=5.4 Hz, — NH —CH 2 —), 12.06 (s, 1H, —NH), 12.72 (s, 1H, —COOH) ppm 13 C-NMR (200 MHz, DMSO): δ 24.1, 31.0, 38.9, 120.5, 120.8, 123.4, 124.1, 128.2, 128.5, 132.2, 138.8, 140.1, 149.4, 162.7, 168.5, 174.2 ppm
[0141] MS m/z (%): 371 (M + , 5), 353 (3), 334 (1), 269 (22), 268 (29), 253 (6), 238 (59), 224 (9), 150 (23), 146 (23), 120 (50), 119 (100), 104 (39), 92 (69 ), 76 (48), 64 (29), 50 (27), 30 (50)
[0142] Elemental analysis of C 18 H 17 N 3 O 6 Calculated: % C=58.22; % H=4.61; % N=11.32. Found: % C=58.15; % H=4.65; % N=11.10.
EXAMPLE 16
4-[2-(4-methoxybenzoilamino)benzoilamino]butanoic acid. (compound 16)
[0143]
[0144] To a suspension of 2.14 g (9.63 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 ml of dry methylene chloride, add 8.90 g (82.39 mmol) of trimethylsilyl chloride and place the reaction at reflux for 5 hours. Then place the flask in an ice bath and add 1.25 g (12.36 mmol) of triethylamine and a solution of 1.40 g (8.24 mmol) of 4-methoxybenzoyl chloride dissolved 10 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 2.32 g (79%) of 4-[2-(4-methoxybenzoylamino)benzoylamino]butanoic acid as a cream-coloured solid.
[0145] M.P.: 172-174° C.
[0146] IR(ATR): ν 3320, 2960, 2837, 1720, 1630, 1592, 1532, 1509, 1446, 1301, 1254, 1167, 1096, 1025, 841, 748 cm −1 H-NMR ( 400 MHz, DMSO): δ 1.79 (m, 1H, —CH 1 — CH2 1 —CH2 1 —), 2.31 (t, 0H, J=7.4 Hz, —CH2 1 —CO—), 3.33 (m, 1H, —CH2 1 —N—), 3.83 (s, 2H, —CH2 2 ), 7.11 (d, 1H, J=8.8 Hz aromatic), 7.16 (m, 0H, aromatic), 7.53 (m, 0H, aromatic), 9 (m, 1H, aromatic), 7.89 (d, 2H, J=8.8 Hz, aromatic), 8.65 (m, 1H, aromatic), 8.87 (t, J=5.4 Hz, — NH —CH3 2 —), 12.08 (s, 1H, —NH), 12.49 (s, 1H, —COOH) ppm
[0147] 13 C-NMR (100 MHz, DMSO): δ 24.2, 31.1, 38.7, 55.5, 114.2, 120.0, 120.1, 122.4, 126.7, 128.2, 128.8, 132.1, 139.7, 162.2, 163.9, 168.7, 174.2 ppm
[0148] MS m/z (%): 356 (M + , 4), 338 (9), 319 (3), 253 (19), 252 (18), 238 (5), 209 (5), 135 (100), 119 (35), 107 (7), 92 (22), 74 (28), 64 (11), 50 (7), 41 (10)
[0149] Elemental analysis of C 19 H 20 N 2 O 5 Calculated: % C=64.04; % H=5.66; % N=7.86. Found: % C=63.97; % H=5.63; % N=7.79.
EXAMPLE 17
4-[2-(4-chlorobenzoylamino)benzoylamino]butanoic acid. (compound 17)
[0150]
[0151] To a suspension of 2.00 g (9.01 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 ml of dry methylene chloride, add 8.36 g (77.00 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 1.17 g (11.55 mmol) of triethylamine and a solution of 1.35 g (7.70 mmol) of 4-methoxybenzoyl chloride dissolved 10 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 1.79 g (65%) of 4-[2-(4-chlorobenzoylamino)benzoylamino]butanoic acid as a cream-coloured solid.
[0152] M.P.: 182-184° C.
[0153] IR(ATR): ν 3069, 2939, 1692, 1672, 1628, 1592, 1525, 1491, 1444, 1332, 1310, 1284, 1259, 1222, 1180, 1110, 1096, 1011, 902, 845, 756, 745 cm −1
[0154] 1 H-NMR (400 MHz, DMSO): δ 1.79 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.31 (t, 1H, J=7.4 Hz, —CH 2 —CO—), 3.32 (m, 2H, —CH 2 —N—), 7.18 (m, 1H, aromatic), 7.54 (m, 1H, aromatic), 7.64 (d, 2H, J=8.5 Hz, aromatic), 7.83 (m, 1H, aromatic), 7.92 (d, 2H, J=8.5 Hz, aromatic), 8.61 (m, 1H, aromatic), 8.89 (t, J=5.4 Hz, — NH —CH 2 ), 12.07 (s, 1H, —NH), 12.61 (s, 1H, —COOH) ppm
[0155] 13 C-NMR (200 MHz, DMSO): δ 24.2, 31.1, 38.7, 55.5, 114.2, 120.3, 120.4, 122.9, 128.2, 128.8, 129.0, 132.2, 133.3 136.9, 139.3, 163.3, 168.6, 174.2 ppm
[0156] MS m/z (%): 360 (M + , 11), 342 (4), 323 (1), 258 (30), 238 (15), 213 (6), 187 (8), 162 (6), 141 (33), 139 (100), 119 (38), 111 (56), 92 (25), 75 (20), 65 (11), 41 (11)
[0157] Elemental analysis of C 18 H 17 ClN 2 O 4 Calculated: % C=59.92; % H=4.75; % N=7.76. Found: % C=59.71; % H=4.77; % N=7.72.
EXAMPLE 18
4-[2-(4-chloro-2-hydroxybenzoylamino)benzoylamino]butanoic acid. (compound 18)
[0158]
[0159] To a suspension of 2.00 g (9.00 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 40 ml of dry methylene chloride, add 8.36 g (77.00 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 1.17 g (11.50 mmol) of triethylamine and a solution of 1.45 g (7.70 mmol) of 4-chloro-2-hydroxybenzoyl chloride dissolved in 5 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 1.35 g (47%) of 4-[2-(4-chloro-2-hydroxybenzoylamino)benzoylamrino]butanoic acid as a white solid.
[0160] M.P.: 205-206 C.
[0161] IR(ATR): ν 3319, 3067, 2936, 1688, 1583, 1525, 1494, 1447, 1408, 1350, 1330, 1302, 1261, 1214, 919, 796, 755 cm −1
[0162] 1 H-NMR (400 MHz, DMSO): δ 1.75 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.28 (t, 2H, J=7.3 Hz, —CH 2 —CO—), 3.26 (m, 2H, —CH 2 —N—), 7.01 (m, 2H, aromatic), 7.18 (m, 1H, aromatic), 7.50 (m, 1H, aromatic), 7.65 (m, 1H, aromatic), 7.87 (m, 1H, aromatic), 8.46 (m, 1H, aromatic), 8.69 (t, 1H, J=5.12 Hz, — NH —CH 2 —), 12.07 (S broad , 3H, —OH, —COOH, —NH-Ph) ppm
[0163] 13 C NMR (200 MHz, DMSO): δ 24.3, 31.1, 38.6, 116.6, 117.8, 119.3, 121.9, 123.2, 123.9, 128.0, 131.1, 131.7, 137.3, 137.6, 158.4 163.9, 167.9, 174.2 ppm.
[0164] MS m/z (%): 376 (M + , 2), 273 (65), 238 (17), 222 (7), 155 (25), 146 (5), 120 (39), 119 (100), 99 (13), 92 (43), 63 (27), 30 (45)
[0165] Elemental analysis of C 18 H 17 ClN 2 O 5 Calculated: % C=57.38; % H=4.59; % N=7.43. Found: % C=57.19; % H=4.57; % N=7.41.
EXAMPLE 19
4-[2-(5-chloro-2-hydroxybenzoylamino)benzoylamino]butanoic acid. (compound 19)
[0166]
[0167] To a suspension of 2.30 g (10.4 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 40 ml of dry methylene chloride, add 9.56 g (88.50 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 1.34 g (13.30 mmol) of triethylamine and a solution of 1.67 g (8.85 mmol) of 5-chloro-2-hydroxybenzoyl chloride dissolved in 5 ml of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Purify the reaction product by recrystallization (EtOH/H 2 O). This yields 0.95 g (29%) of 4-[2-(5-chloro-2-hydroxybenzoylamino)benzoylamino]butanoic acid as a white solid.
[0168] M.P.: 222-223 C.
[0169] IR(ATR): ν 3315, 2958, 1693, 1657, 1594, 1524, 1479, 1447, 1360, 1325, 1303, 1272, 1213, 914, 812, 749 cm −1
[0170] 1 H-NMR (400 MHz, DMSO): δ 1.75 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.28 (t, 2H, J=7.3 Hz, —CH 2 —CO—), 3.26 (m, 2H, —CH 2 —N—), 7.01 (m, 2H, aromatic), 7.18 (m, 1H, aromatic), 7.50 (m, 1H, aromatic), 7.50 (m, 1H, aromatic), 7.63 (m, 1H, aromatic), 7.83 (m, 1H, aromatic), 8.43 (m, 1H, aromatic), 8.67 (t, 1H, J=5.5 Hz, — NH —CH 2 —), 11.99 (S broad , 3H, —OH, —COOH, —NH-Ph) ppm
[0171] 13 C NMR (200 MHz, DMSO): δ 24.2, 31.1, 38.6, 118.9, 120.5, 122.3, 122.8, 123.3, 124.3, 128.0, 129.4, 131.6, 132.9, 137.4, 155.8, 163.1, 167.8, 174.2 ppm.
[0172] MS m/z (%): 376 (M + , 3), 273 (100), 238 (22), 155 (18), 120 (40), 119 (80), 99 (13), 92 (46), 63 (26), 30 (35)
[0173] Elemental analysis of C 18 H 17 ClN 2 O 5 Calculated: % C=57.38; % H=4.59; % N=7.43. Found: % C=57.27; % H=4.58; % N=7.41.
EXAMPLE 20
4-[2-(2-chlorobenzoylamino)benzoylamino]butanoic acid. (compound 20)
[0174]
[0175] To a suspension of 2.00 g (9.01 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 mL of dry methylene chloride, add 8.36 g (77.00 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 1.17 g (11.55 mmol) of triethylamine and a solution of 1.35 g (7.70 mmol) of 2-chlorobenzoyl chloride dissolved in 5 mL of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl and extract several times with ethyl acetate. Dry the organic phase with MgSO 4 anhydrous and eliminate at low pressure. Wash the crude product several times with ether and finally, purify by recrystallization (EtOH/H 2 O). This yields 1.27 g (36%) of 4-[2-(2-chlorobenzoylamino)benzoylamino]butanoic acid as a brown solid.
[0176] M.P.: 110-112° C.
[0177] IR(ATR): ν 3308, 1730, 1659, 1627, 1598, 1560, 1513, 1445, 1433, 1310, 1287, 1255, 1168 cm −1
[0178] 1 H-NMR (400 MHz, DMSO): δ 1.73 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.26 (t, 2H, J=7.0 Hz, —CH 2 —CO—), 3.24 (m, 2H, —CH 2 —N—), 7.21 (m, 1H, aromatic), 7.51 (m, 4H, aromatic), 7.65 (m, 1H, aromatic), 7.79 (m, 1H, aromatic), 8.53 (m, 1H, aromatic), 8.82 (S broad , 1H, — NH —CH 2 —), 11.89 (s, 1H, —COOH), 12.05 (s, 1H, —NH) ppm
[0179] 13 C NMR (100 MHz, DMSO): δ 24.1, 31.1, 38.6, 120.4, 121.1, 123.3, 127.6, 128.2, 128.9, 129.8, 130.2, 131.7, 132.0, 136.3, 138.5, 164.3, 168.2, 174.1 ppm.
[0180] MS m/z (%): 360 (M + , 1), 342 (7), 289 (9), 269 (8), 257 (50), 213 (57), 178 (16), 139 (97) 120 (22), 119 (100), 111 (60), 85 (67), 75 (81), 63 (32), 50 (63), 30 (76)
[0181] Elemental analysis of C 18 H 17 ClN 2 O 4 Calculated: % C=59.92; % H=4.75; N=7.76. Found: % C=59.95; % H=4.77; % N=7.68.
EXAMPLE 21
4-[2-(2-bromobenzoylamino)benzoylamino]butanoic acid. (compound 21)
[0182]
[0183] To a suspension of 2.00 g (9.01 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 mL of dry methylene chloride, add 8.36 g (77.00 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 1.17 g (11.55 mmol) of triethylamine and a solution of 1.68 g (7.70 mmol) of 2-bromobenzoyl chloride dissolved in 5 mL of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl, filter the resulting solid and wash several times with water and with ether. Finally, purify by recrystallization (EtOH/H 2 O). This yields 1.95 g (63%) of 4-[2-(2-bromobenzoylamino)benzoylamino] butanoic acid as a cream-coloured solid.
[0184] M.P.: 117-118° C.
[0185] IR(ATR): ν 3280, 3176, 1731, 1654, 1628, 1598, 1557, 1510, 1444, 1428, 1312, 1286, 1251, 1166, 743, 664 cm −1
[0186] 1 H-NMR (400 MHz, DMSO): δ1.74 (m, 2H, —CH 2 — CH 2 CH 2 —), 2.26 (t, 2H, J=7.3 Hz, —CH 2 —CO—), 3.23 (m, 2H, —CH 2 —N—), 7.21 (m, 1H, aromatic), 7.45 (m, 1H, aromatic), 7.53 (m, 2H, aromatic, 7.61 (m, 1H, aromatic), 8.53 (m, 1H, aromatic), 8.81 (t, 1H, J=5.28 Hz, — NH —CH 2 —), 11.84 (s, 1H, —COOH), 12.03 (s, 1H, —NH) ppm
[0187] 13 C NMR (100 MHz, DMSO): δ 24.1, 31.1, 38.6, 118.6, 120.4, 121.1, 123.3, 128.1, 128.2, 128.7, 131.7, 132.0, 133.2, 138.5, 138.6, 165.2, 168.1, 174.2 ppm.
[0188] MS C 18 H 17 N 2 O 4 79 Br m/z (%): 404 (M + , 1), 303 (32), 257 (20), 238 (20), 221 (22), 185 (100), 178 (12), 157 (31) 143 (26), 119 (60), 90 (31), 76 (41), 50 (39)
[0189] Elemental analysis of C 18 H 17 BrN 2 O 4 Calculated: % C=53.35; % H=4.23; N=6.91. Found: % C=53.32; % H=4.26; % N=6.89.
EXAMPLE 22
4-[2-(3-chlorobenzoylamino)benzoylamino]butanoic acid. (compound 22)
[0190]
[0191] To a suspension of 2.00 g (9.01 mmol) of 4-(2-aminobenzoylamino)butanoic acid in 20 mL of dry methylene chloride, add 8.36 g (77.00 mmol) of trimethylsilyl chloride and allow the reaction to reflux for 5 hours. Then place the flask in an ice bath and add 1.17 g (11.55 mmol) of triethylamine and a solution of 1.35 g (7.70 mmol) of 3-chlorobenzoyl chloride dissolved in 5 mL of dry methylene chloride. Allow the reaction to stir for 30 minutes in an ice bath and 24 hours at room temperature. Eliminate the solvent at low pressure, add 30 ml of 10% NaOH to the crude product and continue stirring the mixture until the oil has completely disappeared. Immediately acidify with concentrated HCl and extract several times with ethyl acetate. Dry the organic phase with MgSO 4 anhydrous and eliminate at low pressure. Wash the crude product several times with ether and finally, purify by recrystallization (EtOH/H 2 O). This yields 0.83 g (30%) of 4-[2-(3-chlorobenzoylamino)benzoylamino]butanoic acid as a cream-coloured solid.
[0192] M.P.: 165-166° C.
[0193] IR(ATR): ν 3307, 3159, 1741, 1721, 1669, 1626, 1589, 1523, 1447, 1419, 1326, 1308, 1256, 1180, 759 cm −1
[0194] 1 H-NMR (400 MHz, DMSO): δ1.78 (m, 2H, —CH 2 — CH 2 —CH 2 —), 2.30 (t, 2H, J=7.0 Hz, —CH 2 —CO—), 3.30 (m, 2H, —CH 2 —N—), 7.21 (m, 1H, aromatic), 7.56 (m, 1H, aromatic), 7.65 (m, 1H, aromatic), 7.71 (m, 1H, aromatic), 7.84 (m, 2H, aromatic), 7.91 (m, 1H, aromatic), 8.57 (m, 1H, aromatic), 8.88 (t, 1H, J=5.3 Hz, — NH —CH 2 —), 12.05 (s, 1H, —COOH), 12.57 (s, 1H, -Ph-NH) ppm
[0195] 13 C NMR (100 MHz, DMSO): δ 24.1, 31.1, 38.6, 120.4, 121.1, 123.3, 127.6, 128.2, 128.9, 129.8, 130.2, 131.7, 132.0, 136.3, 138.5, 164.3, 168.2,174.1 ppm.
[0196] MS m/z (%): 360 (M + , 8), 323 (5), 258 (38), 238 (41), 213 (19), 139 (100) 120 (64), 119 (95), 111 (96), 92 (55), 75 (40), 65 (32), 50 (28), 39 (39)
[0197] Elemental analysis of C 18 H 17 ClN 2 O 4 Calculated: % C=59.92; % H=4.75; % N=7.76. Found: % C=59.87; % H=4.78; % N=7.76.
[0000] The activity of all compounds of the examples described above was studied in animals according to the following experimental model:
[0000] 1. Purpose and Rationale
[0198] Evaluate the absorption of the test product when administered by intracolonic route to rats, whether or not in the presence of adjuvants. The plasma concentration is measured by assaying the Factor Xa-inhibition capacity. The rat is used because it is one of the species commonly used in this type of test.
[0000] 2. Description of the Test Method
[0000] 2.1. Experimental System
[0000]
Description: Wistar male rats, acquired from an accredited supplier.
Weight 200-250 g
Age 9 to 11 weeks
2.2. Mode of Administration
[0202] One intracolonic administration.
[0000] 2.3. Dosage Levels and Administration Volume
[0000]
Dosage level 30 mg/kg of test product +30 mg/kg of adjuvant
Administration volume 1 ml/kg
2.4. Vehicle
[0205] 25% (v/v) propylene glycol in bidistilled water. After dissolving the test product along with the adjuvant if applicable, adjust the pH to approximately 7.4 with NaOH. 3.5. Experimental Design
[0206] The animals will be in fasted state for approximately 18 h with free access to water
[0207] The animals will be randomized to the various experimental groups, with one remaining animal as a reserve per group:
[0208] On the day of the test, the treatments will be administered by intracolonic route, following anaesthesia with ketamine. Administration will be done using a catheter of approximately 8 cm, connected to a 1-ml syringe. The catheter will be introduced in its entirety into the colon through the anus and the test product will be administered slowly into the colon.
[0209] Following the administration of the test product, within the times established in the table, a citrated blood sample (3.8% at a ratio of 1:9) will be drawn by intracardiac puncture under anaesthesia with ketamine.
[0210] Blood centrifugation: 3000 rpm, 10 minutes, 4° C. Plasma freezing (−20±5° C.) until determining the anti-Factor Xa activity.
[0211] A control group that will receive no treatment will be included, simply that one blood sample will be drawn per animal under the same conditions as the treatment group, with considered to be the baseline value of anti-Xa activity.
[0212] The anti-Xa activity will be assayed by the chromogenic method (anti-FXa activity assay kit).
[0000] 3. Evaluation of the Results
[0213] The mean, the standard deviation (RSD) and the standard error of the mean of each experimental group will be calculated for each parameter. If considered adequate, the values obtained in the different experimental groups will be compared by a statistical analysis.
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Amino acid diamides in non α position of formula (1), wherein R 1 is selected from amongst the group consisting of the functional groups alkyl, halogen, NO 2 , OH, OCH 3 alone or associated and R 2 is selected from the group consisting of functional groups H, alkyl, halogen, NO 2 , OH, OCH 3 , which are useful as adjuvants for the administration of biological active agents, as well as pharmaceutical compositions containing these diamides of formula (1) and the use thereof for the manufacture of antithrombotic medications and for the manufacture of a medication for the treatment of a disease selected from amongst the group consisting of inflammation, cancer and allergy.
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This is a continuation of U.S. Ser. No. 355,851, filed May 18, 1989, now U.S. Pat. No. 4,935,732; which is a continuation of U.S. Ser. No. 110,658, filed Oct. 20, 1987, now abandoned.
APPENDIX
An appendix containing a hexadecimal code listing of the control program for the main central processing unit of FIG. 15 in the programming language used with the microprocessor illustrated therein is attached. The appendix contains subject matter which is copyrighted. A limited license is granted to anyone who requires a copy of the program disclosed therein for purposes of understanding or analyzing the present invention, but no license is granted to make a copy for any other purpose including the loading of a processing device with code in any form or language.
CROSS REFERENCE TO RELATED APPLICATIONS
The following reference is made to other applications which are filed Oct. 20, 1987 which are incorporated herein by reference in their entirety.
"Paging Receiver For Receiving Pages From Analog Or Digital Paging Transmitters", Ser. No. 110,512 filed Oct. 20, 1987, now U.S. Pat. No. 4,928,100.
"Paging Receiver With Dynamically Programmable Functionality", Ser. No. 110,664 filed Oct. 20, 1987, now U.S. Pat. No. 4,849,750.
"Paging Receiver With Paging Receiver Identification Code Digits Transmitted In Order of Increasing Significance", Ser. No. 110,511 filed Oct. 20, 1987, now U.S. Pat. No. 4,857,915.
"Paging Receiver Displaying Place of Origin of Pages", Ser. No. 110,522 filed Oct. 20, 1987, now U.S. Pat. No. 4,853,688.
"Paging Receiver With Continuously Tunable Antenna", Ser. No. 110,514 filed Oct. 20, 1987, now U.S. Pat. No. 4,851,830.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to RF paging receivers which receive pages comprised of either numeric characters and/or alphanumeric characters and convey the page to a person possessing the paging receiver.
2. Description on the Prior Art
Paging systems are in use throughout the world. There are paging systems which transmit pages from satellite transmitters to different cities. An example of such a system is that operated by National Satellite Paging which transmits only numeric pages. A system operated by Metrocast permits pages to be transmitted to any city within the system through dedicated communication links between the cities. In the Metrocast system, pages to be transmitted locally are exclusively made by calling into the city where the page is to be made by a local telephone call. A page to be made on a regional basis is called in by an 800 number telephone call to a central facility in San Diego from which the page is transmitted to the city where the page is to be broadcast by the dedicated communication link. The page is received from the communication link at the city where it is to be broadcast and then broadcasted locally by an existing paging service to transmit the page to the person to be paged.
To date, there is no existing national paging system which substantially covers the geographical United States. Because of the cost of hardware, a system like the Metrocast system is not economical in small cities or rural areas where the paging volume is relatively low. Accordingly, while the objective of achieving nationwide paging has been attempted for many years, no existing system integrates local and national paging substantially throughout the geographical United States or throughout the world. The vast majority of paging systems operate totally locally with each system having a limited functionality because of its inability to deliver regional paging. Most paging receivers are tuned to receive only a single channel which inherently limits usage in time frames when heavy paging conditions exist in a local paging system and further prevent usage in other geographical locations where other channels are used.
Typically each existing paging system has unique specifications which prevents operation of one paging receiver in other systems. For example, the paging receiver identification codes are not universal. Furthermore, existing paging receivers will only receive transmissions from a single type of transmitter (analog or digital) systems. As a result of paging receivers differing in design and operation, the cost of paging receivers is higher as a result of smaller manufacturing volumes than would be realized if a single paging receiver was usable for a worldwide network.
Paging receivers in the Metrocast system cyclically scan a plurality of closely spaced channels to detect the presence of a page for the paging receiver on any one of the closely spaced channels. This paging receiver suffers from the inherent disadvantage that the continual scanning of the closely spaced channels requires a substantial power consumption causing the batteries of the pager to have a short life span. Short battery life increases the cost of operation and can cause pages to be lost when the batteries are not promptly replaced.
All paging systems currently issue a paging receiver identification code to each of the paging receivers for purposes of providing a unique identification. There currently is no universal standard for issuing identification numbers to pagers, with the largest system having capacity for issuing only 2,000,000 paging receiving identification codes. Worldwide, there currently are over 12,000,000 pagers in use with projected growth on an annual basis in the paging industry exceeding 20%. Thus, current paging systems do not permit a worldwide paging system to be realized as a result of the actual and projected number of pagers being far larger than the capacity of the identification codes in the largest existing paging system.
All pagers currently monitor the one or more channels which they are designed to receive to detect if a paging receiver identification code accompanying a page on the one or more channels on which they are designed to receive matches a stored paging receiver identification code. If a match exists, then a page is processed and an alarm and a display of the message is made to alert the wearer of the paging receiver of the message contained with the page. These systems transmit the pager identification code in an order of decreasing significance of the digits of the identification code. In other words, if a paging receiver has the identification code 12345, the transmitter precedes the transmission of the page with the sequence of digits 12345. Each pager which receives the channel on which the paging receiver identification code is transmitted continually detects each of the successive digits and maintains its radio frequency receiver on until a mismatch is found between the transmitted and stored paging receiver identification code digits. As a result of the fact that many paging receivers have identification codes in which their more significant digits are common to other paging receivers within a system, a substantial amount of battery power is consumed detecting if a page is intended for a particular paging receiver. Each paging receiver which receives the digits of the paging receiver identification code in an order of decreasing significance is statistically likely to have its radio frequency receiver turned on for most of the transmission of the digits of the paging receiver identification code until the lesser significant digits of the paging receiver identification code are received for the reason that it is the lesser significant paging receiver identification code digits which distinguish one paging receiver from another and only the least significant digit which distinguishes the paging receiver which is desired to receive a particular page from all other paging receivers. Accordingly, the transmission of the paging receiver identification code digits in an order of decreasing significance substantially increases power consumption lessening the life of the batteries of the paging receiver.
Throughout the world different frequency bands have been adopted for tramsmitting pages. In the United States, transmissions are authorized on VHF and UHF bands. In the United States, the channels of the VHF and UHF bands are separated by 5 KHz steps. Moreover, for each of these bands transmitters are in existence which transmit pages by frequency modulation of a digital carrier wave and other transmitters which transmit pages by frequency modulation of an analog carrier wave. Currently no paging receiver exists which is compatible with transmissions from both analog and digital transmitters. Furthermore, Europe has allocated VHF channels for paging with individual channel frequencies being separated by 6.25 KHz steps and Far Eastern countries has allocated paging channels on a 280 MHz VHf band with individual channels being separated by 2.5 KHz steps. Currently, no paging receivers exist which are operational on any more than one of the above-identified frequency bands. The inability of current paging receivers to receive pages on the different frequency bands allocated throughout the world prevents worldwide paging to be received on a single paging receiver.
None of the commercially marketed paging receivers are programmable by command to receive different channels which severely restricts the paging receivers to usage in limited geographical areas. In the United States there are a large number of paging channels in use in different geographical parts of the country. Because of the fact that the existing paging receivers cannot be programmed by command to receive different channels, it is impossible to universally receive pages throughout the country because of the fact that reception of channels is limited to a single channel fixed upon obtaining the paging receiver from the paging service or to cyclically scan a group of closely spaced channels such as with the paging receiver used by the Metrocast system. Neither approach leads itself to being dynamically usable to accept pages in another geographical area where a different channel or channels are in use. The prior art paging receivers' inability to rapidly change the channels which may be received severely limits the usage of paging for business or other travel.
In the prior art as a consequence of paging receivers being designed to receive only a single channel in a particular frequency band or to scan a sequence of closely spaced channels, antenna gain has not been a problem in achieving reception of pages with sufficient signal strength to permit proper decoding and display of the page. Antenna tuning systems have been used to tune a receiver's antenna in military communication for maximum antenna gain prior to receiving communications. However, these systems do not tune antenna gain dynamically during the reception of the communication. When a paging receiver is used to accept multiple bands of channels, environmental characteristics such as variable inductance and capacitance which vary with location, will tend to prevent maximum antenna gain from being achieved especially when the paging receiver is being carried by a person in motion.
Currently, no paging system exists which truly permits paging on a national and international level. This is a consequence of the inability of the paging receivers to receive a large number of channels and further the deficiency of the existing systems in having a universal paging receiver identification code which uniquely identifies each of the paging receivers throughout the world with the possibility existing in the current systems of several pagers having the same paging receiver identification code. A universal paging receiver identification code is needed having the capacity to uniquely identify all of the paging receivers throughout the world.
Currently in the United States a relatively small number of channels are used in the large metropolitan areas where most of the paging traffic occurs. As paging traffic increases in view of the relatively small number of channels predominantly in use in metropolitan areas, there is the likelihood that message traffic during the three peak paging periods that occur each day will increase to the point where the predominantly used small number of channels will become so busy that it is impossible to rapidly transmit pages to a paging receiver. Because of the fact that current paging receivers are not programmable by remote command to receive pages on different channels existing networkds do not have the ability to dynamically switch channels in large metropolitan areas, when one channel becomes so busy that rapid paging is not possible, to another lesser used channel to eliminate delays in transmitting pages to a paging receiver. In fact, in large metropolitan areas there currently are VHF and UHF mobile channels that are currently under utilized due to the current cellular radio system which could be used as alternative paging channels to receive traffic on commonly used stations.
FM analog and digital paging protocols exist. Existing protocols for the FM analog and digital paging systems do not have a high efficiency in transmitting data per transmitted code. Existing digital transmitters modulate a digital FM transmitter with a binary signal which utilizes frequency shift keying of the basic carrier signal to transmit high levels of a bit with a burst of the shifted frequency and the low level bit with the unshifted frequency of the carrier. Thus, each identifiable digit of the transmission from an FM digital paging transmitter can encode only two distinct levels for each frequency burst of the carrier. Analog FM paging transmitters frequency modulate a sinusoidal carrier with a total of 15 tones to create a hexadecimal value transmitting system in which no modulation of the basic carrier frequency is considered to be the "F" value and the remaining 15 different values are encoded by modulating the FM carrier with distinct tones. Paging receivers which are designed to receive analog transmissions require substantial reception time of each tone to validly detect each character. Thus, while the protocol of FM analog paging transmitters transmits a much higher number of data values for each frequency burst, the slowness of the paging receivers in detecting the discrete tones does not result in a high throughput speed of transmitting characters.
Existing paging systems which permit paging in multiple cities suffer from the deficiency that a long distance phone call is required to phone in a page which is to be transmitted to a remote city. Because of the fact that the long distance phone call is charged to the person wishing to make the page or to the operator of the system (800 service), the expense of using these paging systems is increased and may discourage users from making non-local pages. No national or regional prior art paging system permits a page to be initiated from a geographic area outside the area where the paging receiver is normally located by the making of a local phone call and further for the paging receiver to be programmed to receive the page on a particular channel found at the location where the page is to be received.
Current paging receivers do not execute a repertoire of commands permitting the functional characteristics of the paging receiver to be programmed dynamically by RF transmission. Current paging receivers do respond to commands which provide an alarm to the person wearing the paging receiver that a page has been received such as activating a display and/or providing an audio alarm. However, current paging receivers do not execute a diversity of commands in which the system influences operation and structure of the paging receiver, including commands activating the display to indicate if the page has originated locally or from another region, causing the message transmitted with the page to be stored in a particular memory location in the paging receiver and programming the channels on which the paging receiver is to receive pages and permitting the paging receiver to serve as a relay for pages either to be transmitted or received.
Moreover, the prior art paging receivers do not control the scanning of channels in accordance with a program which automatically causes the RF receiver to monitor the channel on which the last page was received for a predetermined time interval and if no carrier is detected on that channel then scanning one or more additional programmed channels for a predetermined time interval until either a carrier is detected on one of the channels being scanned in which case that channel is scanned for the predetermined time interval or in the absence of any carrier being detected on the one or more channels being scanned shutting down the RF receiver after the predetermined time interval. No prior art paging system is known in which a code is transmitted with the paging receiver identification code to restrict reception of pages in particular geographic areas.
Cellular radio systems dynamically assign channels on which cellular radio receivers are to receive telephone calls. To make or receive a telephone call, a mobile cellular radio is locked onto a set up channel through communications with the transmitter which are established when the cellular radio receiver is turned on. The cellular system then assigns the mobile cellular radio to a specific channel while the mobile cellular radio is making or receiving a telephone call within a cell. As the cellular radio receiver moves from one cell to another cell, the channel is dynamically changed from one channel to another channel to maintain a strong signal frequency. A cellular radio receiver does not have a channel memory which stores channels which are to be scanned to establish if a call is forth coming. The dynamic assignment of a channel is initiated by the transmitter for the sole purpose of establishing the channel over which voice communications are to be initiated or to be maintained when moving from one cell to another.
U.S. Pat. No. 4,422,071 discloses a system for programming an identification code of a receiver by a radio frequency communication between a transmitter and the receiver.
SUMMARY OF THE INVENTION
The present invention provides the first paging receiver which is compatible with all existing UHF and VHF paging channel bands and existing paging system FM analog and digital transmitters found in the United States, Japan and Europe. A paging receiver in accordance with the present invention may be programmed dynamically to receive channels in multiple bands including the VHF and UHF bands in the United States, the VHF band in Europe and the 280 VHF Japanese band. The dynamic programmability of channels of the paging receiver of the present invention permits operation in all of the geographic areas identified above with a single paging receiver by programming the paging receiver by a channel programming command to receive one or more channels in the geographic areas to which the pager will be transported. The transmitter transmitting the page in the area where the paging receiver is to receive the page transmits the page on a channel on which the paging receiver has been dynamically programmed to receive the page.
The paging receiver of the present invention and its protocol is compatible with all existing analog and digital transmitters and permits pages transmitted by either analog or digital paging transmitters to be received by a single paging receiver with total transparency to the user of the paging receiver. Furthermore, the adoption of a universal protocol in which each code transmission by a FM digital transmitter encodes multiple values greater than two achieves a high data throughput rate. Moreover, the signal processing circuitry of the paging receiver provides a rapid response time to each transmitted code from either an analog or digital transmitter which further permits the time duration of transmission of each character to be shortened providing a high data throughput. Finally, in accordance with a preferred embodiment of the present invention, a paging receiver identification code format is adopted which permits 100,000,000 distinct paging receivers to be used by the system enabling international use.
The present invention substantially enhances the battery life of batteries used to power the paging receiver. In the first place, each digit of the paging receiver identification code is transmitted as a header on each page in an order of increasing significance of the paging receiver identification code digits. The paging receiver compares each received paging receiver identification code digit with the corresponding digits of its unique stored paging receiver identification code to detect if a mismatch exists at which time the paging receiver is turned off to conserve power until it is turned on again under a control program of the main central processing unit. The comparison of the transmitted paging receiver identification code digits and the stored pager receiver identification code digits continues sequentially until either a total match is found at which time the command and/or page transmitted with the paging receiver identification code is processed or the paging receiver tuner is shut down to conserve power.
Furthermore, reception of pages by a particular paging receiver may be restricted by use of a destination code. Each paging receiver contains a memory for storing a destination code. Pages which are to be received on an area basis by a paging receiver are transmitted with the destination code being the first digit of the transmission of the paging receiver identification code. If a match is not found between the transmitted destination code and any stored destination code contained in the memory of the paging receiver, the paging receiver is immediately shut down to conserve power. If a match is found between a transmitted destination code and any stored destination code, the paging receiver then processes the subsequently transmitted paging receiver identification code digits which are transmitted in an order of increasing significance of its digits as described above. The invention eliminates the problem of each paging receiver which is to receive a national or regional page from responding to resident local paging which consumes substantial amounts of battery life.
Furthermore, in accordance with the invention, each paging receiver contains a memory for storing the last channel on which a carrier was detected. The control program of the main central processing unit for the paging receiver automatically activates the paging receiver to receive the last channel first because of the statistical probability that pages are more likely to be found on that channel than on additional channels stored in a channel memory which are thereafter received by the paging receiver in an order determined by a control program. Battery life is enhanced by ordering the sequence in which channels are to be received such that the statistically most likely channel on which a transmission is likely to be received is the first channel received when a plurality of channels are to be scanned for the presence of carrier.
The diverse command repertoire of the paging receiver further enhances its usage by permitting programming of channels, processing of storage location of pages in memory, place of origin display of pages, use of the paging receiver to relay pages to external devices and regional or group specific reception of pages.
A method for receiving a page in a remote area when a paging receiver has been transported from a local area where the paging receiver has been programmed to receive pages on one or more channels to the remote area in accordance with the invention includes programming the paging receiver by one or more channel programming commands transmitted by an RF carrier from a transmitter located in the local area while the paging receiver is located in the local area to receive one or more programmed channels in the remote area; transporting the paging receiver from the local area to the remote area where the page is to be received; and relaying the page from the local area to a transmitter located in the remote area and transmitting the page from the transmitter in the remote area on one of the one or more programmed channels to the paging receiver. The paging receiver has a channels memory for storing channel on which the paging receiver is to receive pages and a controller, responsive to a channel programming command for decoding each channel frequency changing command to obtain a channel to be stored in the channel memory and causing storage in the channel memory. The paging receiver receives a page over one of the channels programmed by the channel programming command while located in the remote area. Further in accordance with the method, a destination code is stored in a memory of the paging receiver to distinguish pages originating in the remote area and transmitted within the remote area and pages originating in the local area, relayed to the transmitter in the remote area and transmitted by the transmitter in the remote area to the paging receiver located in the remote area; and the paging receiver in the remote area compares each transmission received on the one or more programmed channels with the stored destination code and turns off the paging receiver upon a match not being detected between the stored destination code and a transmission on one of the one or more programmed channels. Further in accordance with the method, programming the memory of the paging receiver with the destination code is accomplished with the channel programming command; and storage of the destination code is in the channel memory. The first character of each page transmitted by the transmitter in the remote area to the paging receiver is the destination code stored in the memory; and the paging receiver receives at least one additional digit in a page if a match is detected between the transmitted and stored destination codes and turns off immediately if a match is not found. The paging receiver is issued a unique paging receiver identification code; the page transmitted by the transmitter in the remote area is transmitted with a paging receiver identification code immediately following the destination code with digits of the transmitted paging receiver identification code being transmitted in an order of increasing significance; when a match is detected between the transmitted and stored destination code, the paging receiver compares successive digits of the transmitted paging receiver identification code and corresponding digits of the stored paging receiver identification codes; the paging receiver turns off imediately upon a match not being detected between a digit of the transmitted and stored paging receiver identification codes; and the paging receiver decodes a page following the transmitted paging receiver identification code if all of the digits of the transmitted and received paging receiver identification codes match.
A method for receiving a page by a paging receiver in a local area on a channel on which other paging receivers receive pages includes programming the paging receiver by one or more channel programming commands transmitted by a RF carrier from a transmitter located in the local area to the paging receiver located in the local area with one or more channels to be received in the local area and programming a memory with a destination code distinguishing pages to be received on the one or more programmed channels in the local area from a page to be received by the paging receiver or a group of paging receivers less than a total number of paging receivers within the local area that receive the one or more programmed channels; the paging receiver in the local area comparing each transmission received on the one or more programmed channels with the stored destination code and turning off the paging receiver upon a match not being detected between the stored destination code and a transmission received on one of the programmed one or more programmed channels, the channel programming command programming the destination code; and storage of the destination code and the one or more programmed channels being in a channel memory. A first character of each page to be transmitted to the paging receiver is the destination code stored in the memory; and the paging receiver receives at least one additional code transmission in a page if a match is detected between the transmitted and stored destination codes and turns off immediately if a match is not found. The paging receiver is issued a unique paging receiver identification code; the page is transmitted with a paging receiver identification code immediately following the destination code with digits of the paging receiver identification code and corresponding digits of the stored paging receiver identification code being compared; the paging receiver turns off immediately upon a match not being detected between a digit of the transmitted and stored paging receiver identification codes; and the paging receiver decodes a page following the transmitted paging receiver identification code if all of the digits of the transmitted and received paging receiver identification codes match.
A RF paging receiver which is programmable by a transmitted channel programming command to receive one or more channels in a plurality of areas including one or more areas in which pages do not originate and being programmable to control in which of the plurality of areas pages may be received by the paging receiver over the one or more channels, for pages to be received in a first area, each page containing a multidigit transmitted paging receiver identification code which identifies a paging receiver to receive a command in the first area over theone or more channels and for pages to be received in a second area each page containing an area destination code distinguishing the second area from the first area which is transmitted prior to transmission of the multidigit paging receiver identification code in accordance with the invention includes a RF tuner for receiving a channel on which pages are to be received; a channels memory storing one or more channel to be received by the RF tuner, the channels being theone or more programmable channels which may be received in the first area or the one or more channels which may be received in the second area, the one or more channels which may be received in the second area containing the destination code; a controller responsive to the RF tuner, for decoding each channel programming command into a specific channel to be received by the RF tuner, programming the channel memory with a specific channel contained in the decoded command including destination code which is to be received, decoding a first received character or digit of a transmission and comparing the first character or digit received with the stored destination code, if a match exists between the first character or digit and the destination code, the control means causing the RF tuner to remain in an activated state to sequentially receive one or more digits of the transmission and if a match does not exist between the first digit and the destination code, the controller causing the RF tuner to turn off.
A RF paging receiver for receiving pages on a channel frequency which are to be received selectively within one or more areas within a plurality of areas in which pages are transmitted on the channel with each page being transmitted with a predetermined protocol in which a destination code controlling in which of the areas the paging receiver is to receive the page when reception of a page in less than all of the plurality of areas is desired followed by a multidigit paging receiver identification code identifying the paging receiver which is to receive the page in accordance with the invention includes a RF tuner for receiving the channels on which the pages are to be transmitted; a memory for storing a unique multidigit paging receiving identification code of the paging receiver; a memory for storing the destination code controlling areas in which the tuner is to receiver pages on the channel; and a controller, responsive to the RF tuner, decoding a first character or digit of a page received on the channel and comparing the stored destination code with the first character or digit in response to match not being found turning off the RF tuner. The controller, in response to a match being found between the stored area destination code and the first character or digit of the received transmission on the channel frequency, maintains the RF tuner in an activated state for receiving the transmitted paging receiver identification code sequentially digit by digit and comparing each decoded digit sequentially with corresponding digits of the stored unique paging receiver identification code to determine if a match exists and if a match of all digits of the transmitted and stored digits of the paging receiver identification codes is found, processes the page and when a match is not found during the sequential comparison of digits of the stored and transmitted paging receiver identification codes, turns off the RF tuner. The protocol of the transmission of the paging receiver identification code is with the digits transmitted in an order of increasing significance, and the controller compares the transmitted paging receiver identification code digits with the stored paging receiver identification code digits in the order of increasing significance until a match is not found between one of the stored and transmitted digits of the paging receiver identification codes at which time the controller deactivates the RF tuner or a complete match is found between the stored and transmitted digits of the paging receiver identification codes at which time the message is processed by the controller. A channel memory is provided which is programmable to store one or more channels to be received by the RF receiver and wherein the paging receiver receives channel programming commands each specifying a particular channel to be received from a number of possible channels which may be programmed to be received and a destination code to be stored in the memory for storing the destination code if reception in less than all of the plurality of areas is desired; and the controller is responsive to each channel programming command to store in the channel memory the channel to be received and to store in the memory for storing the destination code any destination code transmitted with a channel programming command and the controller activates the RF receiver to receive one or more of the programmed channels. The controller sequentially activates the RF tuner to receive the stored channels in the channel memory in a predetermined order in the absence of detection of a carrier from all of the stored channels by the RF tuner. The activating the RF tuner to receive sequentially the stored channels in a predetermined order is repeated cyclically for a predetermined channel receiving time interval in the absence of detection of a carrier on all of the stored channels and causes activation of the RF tuner to receive stored channels in the predetermined order. The controller in response to the detection of the carrier being received by the RF tuner activates the RF receiver cyclically during a predetermined channel receiving time interval to cause the RF receiver to cyclically receive the carrier. During each cycle of receiving the carrier by the RF, the controller activates the tuner to receive the channel for a first predetermined time interval and monitors the RF tuner to determine if the channel carrier is received during the first predetermined time interval and if the channel carrier is received, the controller continues the activation of the RF tuner to cause the sequential reception and decoding of digits of a transmitted paging receiver identification code specifying a particular paging receiver to receive the channel programming command and compares the received digits sequentially with corresponding digits of a paging receiving identification code stored in the memory for storing the paging receiver identification code of the paging receiver in an order of increasing significance of the digits of the stored paging receiver identification code. When the controller detects a complete match between the transmitted digits of the paging receiver identification code and the stored digits of the paging receiver identification code, the controller further decodes the channel programming command and programs the channel memory with the decoded channel to be received. The controller stores in an operating channel section of the channel memory the last channel on which the RF tuner detected a channel carrier and upon turning on of the paging receiver, the channel stored in the operating channel section is received by the RF tuner. The controller causes storage of channels which are to be programmed to be received by channel programming commands in an area channel memory section of the channel memory and the controller activates the RF tuner to receive the channels in a predetermined order first from the operating channel section and then sequentially from the area channel section of the channel memory. The controller sequentially activates the RF tuner to receive the channels stored in the channel memory in response to detection of a channel carrier from any one of the programmed channels, stores the channel of the detected channel in the operating channel section and activates the RF tuner to receive the channel stored in the operating channel section. A plurality of tuners each for receiving channels from a band of frequencies which have been programmed to be received by the channel programming command is provided, only one of the tuners being activated at any one time to receive a programmed channel and a power controller is provided, coupled to the controller and to the plurality of tuners, for controlling the activation of the plurality of tuners by the selective application of power to only the tuner which is to receive a programmed channel and wherein the controller provides the power controller with a signal identifying from which band of channels a channel is from which one of the plurality of tuners is to receive. The controller sequentially activates one or more of the individual tuners to receive channels stored in the channel memory under the control of a control program. The control program of the controller sequentially activates one or more of the plurality of tuners to receive channels stored in the channel memory in a predetermined order when a channel carrier from any one of the stored channels is not detected by any one of the tuners.
A RF paging receiver which is programmable by a command to receive pages over one or more channels and is further programmable by a command with a destination code to enable reception of the pages on the one or more programmable channels by a designated group, which are not to be received by all other paging receivers receiving the one or more channels being transmitted with the destination code in accordance with the invention includes a memory for storing the destination code; a memory for storing the channels on which the paging receiver is to receive pages; a RF tuner for receiving a command for programming the memory for storing channels with one or more channels on which pages are to be received and a command for programming the memory for storing the destination code; and a controller, responsive to the RF tuner, for decoding commands to receive pages on the particular channels and commands specifying a destination and storing in the memory for storing channels the one or more channels on which pages are to be received and storing a destination code in the memory for storing the group destination code, and comparing a first received character of a page on one of the programmed channels with any programmed destination codes stored in the memory storing the destination code and if a match does not exist, turning off the RF tuner. The destination code is transmitted as a first part of each page which is to be received by a paging receiver as part of the designated group and the controller turns off the RF receiver immediately upon not detecting a match between a stored destination code and a transmitted destination code. Each channel and associated destination code are programmed by a channel programming command; and the controller decodes each channel programming command to obtain a channel to be received and any destination code to be associated with that channel for receiving pages by the paging receiver. A single channel memory is used for storing the programmed channels and any associated destination codes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a preferred embodiment of a paging receiver in accordance with the present invention.
FIG. 2 is a diagram of the channel memory used for storing channels to be received.
FIG. 3 is a functional block diagram of the operation of a paging receiver in accordance with the present invention in processing signals from an analog and digital transmitters.
FIG. 4 is a diagram illustrating the order of transmission of the digits of the paging receiver identification code.
FIG. 5 is a diagram illustrating the order of transmission of a destination code and the digits of the paging receiver identification code.
FIG. 6 is a flowchart illustrating the order of scanning the channels of the channel memory and processing of the destination code and the paging receiver identification code.
FIG. 7 is a circuit schematic of the antenna circuit 14 of FIG. 1.
FIG. 8 is a circuit schematic of the amplifier and mixer 18 of FIG. 1.
FIG. 9 is a circuit schematic of the amplifier and mixer 22 of FIG. 1.
FIG. 10 is a circuit schematic of the amplifier and mixer 20 of FIG. 1.
FIGS. 11A-C are a circuit schematic of the voltage controlled oscillator 30 of FIG. 1.
FIG. 12 is a circuit schematic of the phase lock loop 28 of FIG. 1.
FIG. 13 is a circuit schematic of the IF processing circuit 34 of FIG. 1.
FIGS. 14A-B are a circuit schematic of the tone decoder 56 of FIG. 1.
FIGS. 15A-B are a circuit schematic of the main CPU 24 of FIG. 1.
FIG. 16 is a circuit schematic of the ASIC circuit A2 of the antenna controller 44 of FIG. 1.
FIG. 17 is a circuit schematic of the buffer amplifier 50 and low pass filter 52 of FIG. 1.
FIG. 18 is a circuit schematic of the power controller 26 of FIG. 1.
FIGS. 19A-B are a circuit schematic of the antenna controller 44 of FIG. 1 without the ASIC circuit of FIG. 16.
FIG. 20 is a circuit schematic of the LCD display driver 62' of FIG. 1.
FIG. 21 illustrates the operation of the present invention in making a page to a remote area.
DESCRIPTION OF THE PREFERRED EMBODIMENT
I. Paging Receiver Architecture
FIG. 1 illustrates a block diagram of paging receiver 10 in accordance with the invention. Actual circuits for implementing the various blocks of the block diagram of FIG. 1 are set forth below in FIGS. 7-20. Additionally, the main control program for the main CPU 24 is set forth in the above-reference Appendix. An internal antenna 12 functions to receive a total of 10,600 possible channels from the three discrete frequency bands referred to above in the Description of the Prior Art. Because of the large number of possible channels which may be received in the distinct three frequency bands, the antenna 12 has a broad band characteristic. In the paging receiver of the present invention, the antenna 12 is designed to be resonant as close as is reasonably possible in all of the three frequency bands which it is designed to receive. In other words, an optimum impedance match is desired. However, the effects of the environment in which the antenna 12 is disposed during operation (a paging receiver is typically clipped to the belt of a person) cause a variation in the degree of resonance as a consequence of variable inductance and capacitance cause by a person's body etc. in the environment of the antenna. Thus, the gain of the antenna 12 is subject to substantial variation as a consequence of the person on which the pager is located and the physical environment in which the pager is located both of which can substantially degrade the gain of the received page applied to antenna circuit 14. The antenna circuit 14 is a tuner containing variable capacitance diodes to which is applied an ANTENNA TUNING SIGNAL to maximize the gain of the antenna 12 for the particular channel that RF tuner 16 is tuned to receive. A circuit schematic of the antenna circuit is illustrated in FIG. 7. The antenna circuit 14 is tuned by the ANTENNA TUNING SIGNAL which functions to tune the antenna 12 to achieve maximum gain in a manner described below in detal. The RF tuner 16 is comprised of three separate radio frequency amplifiers and mixers 18, 20 and 22 which respectively receive UHF and 280 MHz VHF and VHF frequency bands. A circuit schematic of the UHF amplifier and mixer circuit 18 is illustrated in FIG. 8; a circuit schematic of the 280 VHF amplifier and mixer circuit 20 is illustrated in FIG. 10; and a circuit schematic of the VHF amplifier and mixer circuit 22 is illustrated in FIG. 9. Only one of the amplifiers and mixers 18, 20 and 22 is energized during reception of any of the channels which cuts down on power consumption. A main CPU 24 controls the activation of a power controller 26 which selectively activates one of the amplifier and mixer circuits 18, 20 and 22 depending upon in which of the UHF, 280 VHF and VHF frequency bands a page is to be received. The digital RECEIVER TUNING SIGNAL outputted by the main CPU 24 specifies one of the 10,600 possible channels to be received by the preferred embodiment which are stored in ROM 58 as discussed below. The RECEIVER TUNING SIGNAL is applied to phase lock loop 28 which frequency locks voltage controlled oscillator 30 on the particular channel specified by the RECEIVER TUNING SIGNAL. When a particular channel is to be received by the RF tuner 16, the main CPU 24 digitally commands the power controller 26 to activate a particular one of the amplifier and mixer circuits 18, 20 and 22 which is to receive the channels to be received. By deactivating the remaining two amplifier mixer circuits power is conserved over that which would be consumed if all three amplifiers and mixer circuits 18, 20 and 22 were simultaneously activated. A circuit schematic of the main CPU 24 is illustrated in FIG. 15 with a suitable control program contained in the above-referenced Appendix; a circuit schematic of the power controller circuit is illustrated in FIG. 18; a circuit schematic of the phase lock loop circuit 28 is illustrated in FIG. 12; and a circuit schematic of the voltage controlled oscillator 30 is illustrated in FIG. 11. The voltage controlled oscillator 30 produces an output frequency which is mixed with the signal being received by one of the amplifier and mixers 18, 20 and 22 to produce a 21.4 MHz output signal. The 21.4 MHz output signal is filtered by a 21.4 MHz filter 32. The output of the 21.4 MHz filter 32 is applied to an IF processing signal circuit 34 to produce the IF signal of 450 kHz. The output signal from the mixer oscillator 36 is applied to an IF amplifier 38 which amplifies the IF signal to a level sufficient for discrimination by FM discriminator circuit 40. A RSSI circuit (received signal strength indicator) 42 produces an output signal having a magnitude directly proportional to the level of the output signal from the discriminator 40. A circuit schematic of the IF processing circuit 34 is illustrated in FIG. 13. The RSSI signal outputted by the RSSI circuit 42 is applied to an antenna controller circuit 44. The antenna control circuit 44 contains an analog-to-digital converter 46 which converts the analog RSSI signal into digital format suitable for processing by a dedicated ASIC microprocessor. The antenna controller 44 contains an ASIC microprocessor based control circuit which executes a computer program contained in a ROM in the ASIC circuit. The ASIC circuit functions to produce a wobble signal which is outputted as a variable digital value which is applied to digital-to-analog converter 48 to produce the ANTENNA TUNING SIGNAL having a variable analog value which causes the antenna circuit 14 to be tuned variably through a frequency band for the purpose of continually locking on the point of maximum gain as a channel is being received. The variation in signal amplitude caused by the wobbling of the tuning frequency of the antenna circuit 14 is detected by the RSSI circuit 42 so that the antenna controller circuit 44 continually outputs an ANTENNA TUNING SIGNAL which tunes the antenna circuit 14 to achieve maximum gain for the antenna 12. The ANTENNA TUNING SIGNAL compensates for environmental factors which change the gain of the antenna 12 during reception such as variable inductance and capacitance caused by a person's body. A circuit schematic of the antenna controller 44 is illustrated in FIG. 16. The discriminator circuit 40 outputs either no signal (level F) or one of fifteen discrete sinusoidal frequencies each of which encodes a different signal value received from either an analog or digital FM paging receiver transmitter as described below. A buffer amplifier 50 amplifies the sinusoidal output signal from the discriminator circuit 40 to a level to create a square wave having a period equal to the period of the sinusoidal signal outputted by the discriminator 40. The square wave outputted by the buffer amplifier 50 is filtered by low pass filter 52 to attenuate frequencies below 400 hertz. A circuit schematic of the buffer amplifier and low pass filter is illustrated in FIG. 17. The output of the low pass filter 52 is applied to high pass filter 54 which attenuates frequencies above 3000 hertz. A tone decoder circuit 56 converts the discrete tones contained within the 400 to 3000 hertz pass band defined by the low pass filter 52 and high pass filter 54 as described below in FIG. 3 to produce an output level signal indicative of 16 possible values. The main CPU 24 processes successive coded transmissions of data by combining them into a two-digit decimal number and decoding the two-digit number into alphanumeric characters. A table correlating the decimal values with their corresponding characters is set forth below. The control program for the main CPU 24, set forth in the Appendix referred to above, is stored in ROM 58. The ROM 58 also stores the possible channels which may be received, which in the preferred embodiment are 10,600, a command structure table used for decoding each of the commands discussed below, as well as the display control for the LCD display 64'. Variable data is stored in RAM 60. The RAM 60 has separate memory sections for storing pages including specific memory sections which are addressable by command, the channels which are programmed to be received by the channel programming command including any destination code for restricting the place of reception of pages or a group of paging receivers to receive a page in a geographical area in a channel memory and the paging receiver identification. In the preferred embodiment there are 15 separate memory sections which store pages with sections 11-14 being addressable by command and sections 1-10 and 15 not being addressable by command. The main CPU 24 controls a liquid crystal display driver circuit 62'. A circuit schematic of the liquid crystal display driver is illustrated in FIG. 20. The liquid crystal driver circuit 62' drives a liquid crystal display 64 described below in FIG. 3. An external data port 67 is used to relay the output signal from the discriminator 52 to another data processing or storage device 67' when the main CPU 24 executes an external data command discussed below. A port 68 is coupled to the main CPU 24 for driving an external printer. A port 69 is provided for establishing necessary communications between the main CPU 24 and an external printer. A display switch 70 is used for activating the display 64'. A light switch 71 is used for activating back lighting of the display 64'. The switches 70 and 71 may also be used for inputting data when suitable displays are made on the display 64' by the control program of the main CPU 24. Port 72 is connected to the paging receiver battery (not illustrated) for providing power. Port 73 is provided for activating an audio alarm contained in the paging receiver and port 74 permits connection to an external antenna which may be used when the paging receiver is connected to an external device such as a printer.
A commercial embodiment of the paging receiver 10 illustrated in FIG. 1 has 10,600 discrete channels stored in ROM 58 from the three discrete bands which may be received by the amplifier and mixers 18, 20 and 22 as described above. The main CPU 24 is responsive to a channel programming command, described below with reference to the commands which the main CPU 24 executes, to dynamically tune the RF tuner 16 to discrete channels. Each channel programming command is decoded by the main CPU 24 to extract a channel, from the 10,600 possible channels stored in ROM 58, to be stored in a channel memory section 62 of the random access memory 60 described below with reference to FIG. 2.
II. Channel Memory
FIG. 2 illustrates the channel memory 62 which is comprised of an operating channel section 64 storing a single channel and an area channel section 66 storing up to 15 discrete channels to be scanned sequentially by the RF tuner 16 under the control of the operating program of the main CPU 24. Illustrated below the operating channel section 64 and the area channel section 66 is an arrow indicating the order of channel reception by the RF tuner 16 when channels are being scanned to detect a carrier frequency. The control program of the main CPU 24 changes the channel stored in the operation channel section 64 to automatically have the channel of the last received carrier received by the RF tuner 16 stored therein. The channel stored in the operation channel section 64 is one of the channels that the channel memory 62 of the RAM 60 has been programmed to receive by the channel programming command. It should be understood that while 15 possible discrete channels may be stored in the area channel section 66, it is only required that the area channel section 66 be programmed with only one channel which is typically the case when the paging receiver is to operated locally to receive only a single channel. In that case, the operating channel section 64 automatically stores the only channel that the RF receiver 16 will receive upon activation by the main CPU 24 and reception of the carrier signal. Furthermore, it should be understood that any number of channels may be utilized in practicing the invention. Each time the control program of the main CPU 24 outputs a channel from the channel memory 62 to be received by the RF tuner 16, the main CPU 24 applies the RECEIVER TUNING SIGNAL in the form of a digital signal to the phase lock loop 28 which activates the voltage controlled oscillator 30 to produce a 21.4 MHz signal from the single activated amplifier and mixer circuit 18, 20 and 22. The control program of the main CPU 24 analyzes the signal which is outputted from the channel memory 62 and applies a control signal to the power controller 26 which selectively applies power from the power circuit 66 to only the particular one of the RF amplifier and mixers 18, 20 and 22 which is to receive the channel specified by the RECEIVER TUNING SIGNAL thereby saving power consumption of the battery.
The individual channels of the area channel section are programmed at the time that the paging receiver identification code is sent to the paging receiver identification code memory described below when the pager is issued to a customer and further are also reprogrammed when the customer desires to "roam" to another service area such as during business travel in which it may be desired to receive pages on the same channels that the paging receiver is currently programmed to receive in which case a destination code will be added by the channel programming command or to receive different channels in which case different channels will be programmed. The programming of channels may also be accomplished dynamically during local paging to switch the paging receiver to channels which are not as busy as a channel that the paging receiver is currently programmed to receive. As is apparent from FIG. 2, during channel scanning for the purpose of finding a channel on which at least one carrier is present, channels to be received are selectively outputted from the operating channel section 64 first and then from the successive section 66 of the area channel section. Each of these channels causes the phase lock loop 28 to lock the voltage controlled oscillator 30 to a channel necessary to produce the 21.4 megahertz signal from the activated RF amplifier and mixer circuits 18, 20 and 22 which is to receive the particular channel. The control program causes the channel which is stored in the operating channel section 64 to be cyclically received for a predetermined time interval, such as but not limited to 15 minutes, by activating the RF tuner 16 once every 900 milliseconds, or other appropriate channel, to sample the channel for the presence of a carrier signal and if carrier signal is present to compare the paging receiver identification code discussed below transmitted with the page in the order of increasing significance of the digits until a mismatch between the transmitted paging receiver identification code digits and the digits of a paging receiver identification code stored in the random access memory 60 is detected at which time the RF tuner 16 is shut off to conserve power.
III. Universal Reception of Pages From Either Analog or Digital Transmitters
FIG. 3 illustrates a detail block diagram of the buffer amplifier 50, low pass filter 52, high pass filter 54 and tone decoder 56 of the present invention for universally processing signals transmitted from either analog or digital FM paging transmitters. The preferred form of the signal protocol of the present invention utilizes the following tones to encode 16 discrete signal values as stated in a hexadecimal numbering system as follows: 600 Hz.=0; 741 Hz.=1; 882 Hz.=2; 1023 Hz.=3; 1164 Hz.=4; 1305 Hz.=5; 1446 Hz.=6; 1587 Hz.=7; 1728 Hz.=8; 1869 Hz.=9; 2151 Hz.=A; 2435 Hz.=B; 2010 Hz.=C; 2295 Hz.=D; 4059 Hz.=E; and no tone (absence of modulated carrier signal)=F. Any existing analog FM paging transmitter can be used to output a carrier wave having a frequency which is frequency modulated with the above-described tones. Similarly, any existing digital FM paging transmitter can be used to output a square wave signal having a period modulated with the above-described frequencies encoded thereon. The output from the frequency discriminator 40 is applied to a sine wave to square wave converter 50' which amplifies the sinusoidal input signal to convert it to a square wave having a period equal to a period of the sinusoidal input signal. The output of the sine wave to square wave converter is applied to a noise debouncer circuit 70' which removes jitter from the input square wave signal to provide precise period information on its output. The output from the noise debouncer circuit 70' is applied to a shift register 72' having a number of stages requiring a predetermined time duration of the input square wave outputted by the noise debouncer circuit 70' to be applied to produce an output. The shift register 72' is reset each time the signal level from the sine wave to square wave converter 50' is zero or changes frequency. The function of the shift register 72' is to eliminate transient signals which are not valid signal levels. The number of stages is chosen to be sufficient to produce an output when an actual tone used for encoding valid information is received while blocking transmission of invalid transient shorter duration tones. Output signals having a duration less than the time required to fill up the shift register 72' are not applied to a group of 15 digital filters 74'. Each of the digital filters has a pass band centered around a different one of the tones set forth above. When a square wave having a frequency falling within the pass band of any one of the fifteen digital filters is applied to the fifteen digital filters 74', an output square wave signal is produced as inputted to the fifteen digital filter from the shift register 72'. A 4 MHz. oscillator 76 applies a 4 MHz. internal reference signal to an AND gate 80 to which the output of the fifteen digital filters 74' is also applied. The high frequency of the oscillator 76 permits a large number of samples to be taken for each high level state of the output of the fifteen digital filters 74'. By providing the high level sampling frequency, it is possible to precisely determine the frequency of the fifteen tones used for encoding signal values with a high degree of accuracy over a single cycle. The ability to detect accurately the frequency over a single cycle provides an extremely high throughput of information when a single cycle is used to encode sixteen possible data values. The sampled output from the fifteen digital filters 74' is passed by AND gate 80 to a counter 82 which counts the number of samples of the output of the digital filters 74' which have a high state during a fixed time period of sampling by AND gate 80. The time interval during which the counter 82 counts the number of high level states passed by the AND gate 80 is not critical but should be chosen to be long enough to permit a high number of possible samples to be taken from a single cycle of the lowest frequency of the 15 tones identified above to permit a high degree of accuracy in the detection of the encoded frequencies transmitted with each page to encode character information. The output of the counter 82 is connected to a range comparator 84 which has an associated ROM 86. The ROM 86 has fifteen discrete address ranges stored therein with each address range being associated with a single one of the 15 tones. Each of the addresses within each range is addressed by a count applied from the counter 82. The range comparator 84 compares the output from counter 82 with addresses of the fifteen discrete ranges contained in the ROM 86 and passes the count from counter 82 to the look-up ROM 88 if a match occurs between the count outputted by the counter 82 and an address of one of the fifteen ranges stored in the ROM 86. If a match does not occur, the count from counter 82 is not passed to the look-up ROM 88. The range comparator 84 resets the counter 82 either upon the elapsing of the predetermined time interval during which the count from the counter 82 has been outputted to the look-up ROM 86 or when there is no match from between the count from the counter 82 and an address contained in one of the ranges stored in the ROM 86. The look-up ROM 88 outputs one of sixteen different numerical values which are representative of the sixteen possible signal values which may be encoded with each hexadecimal digit transmitted by either an analog or digital paging transmitter. The output of the look-up ROM 88 is applied to a signal duration comparator 90' which outputs one of the 16 numerical vaues (0-15) stored in the look-up ROM 88 to the main CPU 24 when the output of the look-up ROM is present for a duration for a time interval such as 10 milliseconds or longer. The purpose of the signal duration comparator 90' is to remove transient conditions which are not indicative of the true transmission of a hexadecimal level by an analog or digital transmitter.
The output numerical values from the signal duration comparator 90' are combined by the main CPU 24 in accordance with its operating program to produce a two-digit decimal number which is decoded to characters in accordance with the following conversion table when characters are transmitted to a paging receiver in accordance with alphanumeric commands A4 and A6 discussed below. When characters are transmitted to a paging receiver in accordance with numeric commands A3 and A5 discussed below, sequential numerical values from the signal duration comparator 90' are decoded as numbers (0-9) as stated above.
______________________________________CONVERSION TABLETwo DigitAddress Character______________________________________01 !02 "03 #04 $05 %06 &07 '08 (09 )10 *11 +12 '13 -14 .15 /16 017 118 219 320 421 522 623 724 825 926 :27 ;28 <29 =30 >31 ?32 ○33 A34 B35 C36 D37 E38 F39 G40 H41 I42 J43 K44 L45 M46 N47 O48 P49 Q50 R51 S52 T53 U54 V55 W56 X57 Y58 Z59 [6061 ]62636465 a66 b67 c68 d69 e70 f71 g72 h73 i74 j75 k76 l77 m78 n79 o80 p81 q82 r83 s84 t85 u86 v87 w88 x89 y90 z91 {92 |93 }94 →95 ←96979899______________________________________
The decoded characters are applied by the main CPU 24 to the random access memory 60 in ASCII character encoding format and to the LCD driver 62' which provides power and logic for their display on the LCD display 64'. The LCD display 64' is of a dot matrix type and has a display which time multiplexes displays as follows. When a page is received, the main control program causes the display 64 to flash with the address location in memory where the page is stored. In response to the flashing of the display as described above, the wearer of the paging receiver presses switch 70 which causes the location header to be displayed. The location headers are "LOCAL" indicating if the page originated in the same area where the paging receiver normally receives pages or "NATIONAL" or "REGIONAL" indicating that the page did not originate in the area where the paging receiver has received the message. In response to the location header, the wearer of the paging receiver presses switch 70 which causes the page to be displayed on display 64' which is stored in the memory area of RAM 60 which was flashed initially. It should be understood that alternatively separate display areas for the memory location header, location header, and page displays may be provided.
IV. Battery Saving
The paging receiver 16 has predetermined scanning time intervals necessary for detecting the presence of the carrier signal, the presence of individual code transmissions (tones) and to cyclically scan up to the 15 possible channels in the channel memory 62. In the embodiment of FIG. 1, the scanning time necessary to detect only the presence of the carrier of the channel frequency is 315 milliseconds for all 15 channels which may be received if the area channel section 66 is completely programmed. It takes approximately 10 milliseconds for the phase lock loop 28 to respond to a channel to be received and another approximately 11 milliseconds for the amplifier and mixers 18, 20 and 22 to respond to the presence or absence of the channel carrier. When a carrier is detected, it takes approximately 33 milliseconds for it to be received by the RF tuner 16 and processed by the main CPU 24 to determine its identity and to compare it with the stored paging receiver identification code as described below. When the channel of the channel memory 62 are cyclically scanned, the RF tuner 16 in the embodiment of FIG. 1 is powered up once every 900 m.s. for a period of 15 minutes at which time the reception by the RF tuner is stopped under the control program.
Each paging receiver is issued a unique paging receiver identification code. A preferred form of the paging receiver identification code is described below in FIG. 4 with reference to a memory map of the paging receiver identification code memory which is located within the random access memory 60. It should be understood that the invention is not limited to the number of digits as described below in the preferred form of the paging receiver identification code and further that is used herein "digit" means any number in any numbering base with the preferred numbering base of the present invention for paging receiver identification codes being base 10. With respect to FIG. 4, each paging receiver identification code 90 is comprised of a group of three most significant digits 92 which have regional significance and are referred to as an "area designation code". In a preferred form of the present invention, these digits are the telephone area code of the location where the person normally wearing the paging receiver resides. For international use, the country code may also be added as an area designation code. Five additional digits 94 of decreasing significance are used to distinguish each bearer of a paging receiver in the particular area identified by the area designation code 92. In a preferred form of the invention, a command is issued by the local channel transmitter to which the paging receiver is normally tuned to receive messages for programming the eight digit paging receiver identification code 90 for storage in the RAM 60. An eight digit paging receiver identification code 90 was chosen in the preferred embodiment of the present invention for the reason that it permits a total of 100,000,000 paging receivers to be uniquely identified in a base ten numbering system. In the preferred form of the present invention, while individual characters are sent by successive tone modulations of a frequency modulated carrier with sixteen possible values per frequency tone, the paging receiver identification codes are issued in a base ten numbering system for the reason that it is easier for most users to understand a base ten numbering system than a base sixteen numbering system.
A significant feature of the present invention in prolonging battery life in the individual paging receiver is that the paging receiver identification code identifying the paging receiver to which a page is directed is sent with the digits in an order to increasing significance. With reference to FIG. 4, the right-most least significant digit is sent first followed by digits of increasing significance as identified by the circled numbers in each of the individual digits of the paging receiver identification code 90 and the arrow above the individual digits labelled "ORDER OF ID DIGIT TRANSMISSION". The paging receiver identification code is processed by the paging receiver in the order of increasing significance of the digits as described with respect to FIG. 4.
In a system with 1,000 paging receivers, the following example demonstrates the battery life saving achieved by the present invention for paging receivers having identification codes 93110000 through 93110999 with the present invention as contrasted with the prior art. If the paging receiver identification code digits are sent in the order of decreasing significance as in the prior art, which is the opposite of the order illustrated in FIG. 4, each paging receiver will respond to the first five digits. Assuming three pages per day, per paging receiver, the paging receiver will turn on RF tuner 16 3000 times per day. If it assumed that each cycle of turning on the RF tuner 16 consumes 300 milliseconds of on time, then each paging receiver will have its RF tuner 16 on for fiteen minutes per day. With the present invention, when the paging receiver identification code is sent in an order of increasing significance of the digits, as illustrated in FIG. 4, 900 paging receivers will immediately turn off after the transmission of the first digit because there will be no match between the first digit transmitted with the page and the stored paging receiver identification code digit as illustrated in FIG. 4. Upon the transmission of the second digit, ninety more paging receivers will turn off. Upon the transmission of the third digit nine more will turn off. With the same 3000 pages per day, the average time a pager will be on is only one minute per day. This produces a 93.4% reduction in battery consumption attributed to the turning on of the RF tuner 16 to merely determine if a page is possibly to be received on a channel to which the paging receiver has been programmed to receive. If a system is expanded to 10,000 pages, the battery savings will be increased with the on time in a system in accordance with the prior art in which the paging receiver identification code digits are sent in the order of decreasing significance being two and one-half hours per day versus only ten minutes per day of on time when the digits of the paging receiver identification code are sent in the order as described in FIG. 4 with it being assumed that the RF tuner 16 on time is the same as described above.
V. Channel Scanning
The operation of the paging receiver in turning on to detect the presence of a channel on one of the channels which it is programmed to receive and the scanning of a plurality of channels of the channel memory 62 is described as follows. Upon turning on of the paging receiver, the channel of the operating channel 64 is sampled for 15 minutes. If one of the amplifier mixer sections 18, 20 and 22 does not detect a tone frequency (a 0-9 tone of 690 milliseconds) of the operating channel section, within 15 minutes, the paging receiver will scan the channel stored in the operating channel memory section 64. If there is no detection of any receptions after the 30 minutes of scanning, the operating program of the main CPU 24 will turn off the RF tuner 16 and display on the message portion 68 of the display 64 "out of range" and activate a beeper.
In the embodiment of the invention illustrated in FIG. 1, when the paging receiver 10 is scanning the channels stored in the memory 62, it is searching for the presence of an RF carrier and the paging receiver identification code. When no carrier is present, the RF receiver 16 will turn on and detect that no carrier is present in approximately 11 m.s. of time and progresses to the next channel stored in the channel memory 62 as indicated by the "ORDER OF CHANNEL RECEPTION." When a last digit of the paging receiver identification code is detected for two consecutive on intervals of the RF tuner 16, the paging receiver will stay on that particular channel for the duration of the paging receiver identification code which spans 1912 milliseconds in the preferred embodiment. Each time carrier from one of the channels is detected or the paging receiver identification code is detected, the fifteen minute timer is reset. This allows the paging receiver to remain on a channel. The paging receiver then samples the channel once every 900 milliseconds for an 11 or 33 m.s. duration to respectively detect if carrier is present and, if so, to identify the code which was transmitted.
The full channel scanning mode of the paging receiver as described above with respect to FIG. 2 requires a sampling time on each channel of approximately 11 milliseconds to detect the carrier wave or 33 milliseconds to fully detect a code transmission depending upon the presence of a carrier signal. If no carrier is present, the paging receiver will detect the lack of a carrier within 6 milliseconds and scan to the next channel. When a carrier is detected, the pager will look for tones 0-9 during the sampling time interval of approximately 33 milliseconds. If a tone is detected, it is stored in the random access memory 60 and scanning of the channels in the full scanning mode as described with respect to FIG. 2 above is continued. When the RF receiver then again receives the same channel, a sample is taken. If a tone is still present, and it is the same tone stored in the random access memory 60 on the previous sampling interval, a match occurs with the previous digit and sampling sequentially occurs with successive digits of the paging receiver identification code until either a match is found in which case the main CPU 24 executes one of the commands described below or a match is not found in which case the RF tuner 16 is turned off and the cyclical sampling every 900 milliseconds continues.
VI. National, Regional, Remote Area, Local, Sublocal and Group Paging
When it is desired to program the paging receiver 10 to receive a fixed channel in a local area for purely local operation, programming may be accomplished manually or automatically. As used herein, "local" identifies an area identified by the area designation code 92. Automatic programming is done with the channel programming command AC with the desired operating channel being sent twice to the pager as described below. The operating program for the main CPU 24 recognizes the sequential sending of the same channel twice by a channel programming command and stores the repeated channel in the area channel section 66 and operating channel section 64. By storing only a single channel in the operation channel section 64 and the area channel 66, the paging receiver is forced to receive only a single channel which is desirable for local operation.
Nationwide, regional, remote area, sublocal and group paging by the paging receiver is programmed as follows. In order to differentiate nationwide, regional (a plurality of areas including one or more areas outside the area identified by the area designation code), remote area (an area other than the area identified by the area designation code), sublocal (a part of an area within an area identified by the area designation code) and group (one or more paging receivers located within the local area) paging from local paging, the paging signal contains a "destination code" having one or more characters which precede the paging receiver identification code that are not recognized by a paging receiver as part of a local page. This ensures that only persons to receive national, regional, remote area, sublocal and group pages will be alerted when transmission occurs. In a preferred form of the invention, the "destination code" is a letter, which is transmitted prior to the transmission of the paging receiver identification code. Paging receivers which are to receive national, regional, remote area, sublocal or group pages are programmed by the channel programming command to store a destination code as a header on the channel. Thus, on a particular channel where some pages are transmitted with destination codes, only the first digit of each page is required to be compared with the stored destination code to enable an identification by a paging receiver programmed to receive pages with destination codes if a page is potentially directed to that paging receiver. The paging receiver which has been programmed with a destination code immediately turns off when a match is not found between the first digit of a page on a received frequency and the stored destination code thereby saving power required to compare the following digits of the stored and transmitted paging receiver identification codes as described below.
FIG. 5 illustrates the order of transmission of the destination code and the digits of the paging receiver identification code for pages which are to be received with use of the destination code. Like reference numerals in FIGS. 4 and 5 are used to identify like parts. The first digit which is transmitted is the destination code 96. Thereafter the individual digits of the paging receiver identification code are transmitted in an order of increasing significance as described with reference to FIG. 4. When it is desired to program a paging receiver to receive pages with use of the destination code, the individual channels of the area channel section 66 of memory 62 are programmed by the channel programming command as described below. However, the first digit of the channels which are to be programmed to be received by the channel programming command contain the destination code 96 character such as the letter A, B, C, etc., which is not recognized as part of a paging receiver identification code, which preferably are base ten numbers. When a paging receiver receives the first digit of the paging receiver identification code, that digit is compared with the first digit of the channels stored in the area channel section 66. If a match occurs, the operating program of the main CPU 24 causes the RF tuner 16 to stay in an on state to compare the subsequent digits of the received paging receiver identification code with the stored paging receiver identification code. If there is no match between the first digit of the transmitted page and the destination code, then the paging receiver RF tuner 16 is immediately turned off to save battery power. By turning off the paging receiver immediately upon the detection of no match between the destination code 96, when the paging receiver is transported to a remote area its on time to receive pages will not be influenced by pages "local" to the remote area for the reason that the first digit mismatch which must occur when any page originating from an area into which the paging receiver has been transported will immediately be detected as a mismatch causing the RF tuner 16 to be turned off.
FIG. 6 illustrates a flow chart illustrating the operation of the control program of the main CPU 24 in scanning channels including the processing of pages transmitted with destination codes. The program starts at point 100 where the channel of the operation channel section 64 is scanned by the RF receiving section 16. If channel carrier is not present, the RF tuner 16 turns off for 900 milliseconds and then again checks if carrier is present. If carrier is present, the operating program proceeds to point 102 where a determination is made whether or not the program is in the scanning mode in which the channels of the operating channel section 94 and area channel section 96 are sequentially scanned for an interval of 30 minutes as illustrated in FIG. 2. If the program is not in the scanning mode, which is indicative of only the operation channel section channel 94 being scanned, the program proceeds back to point 100. If the answer is "yes" at point 102, the program proceeds to point 104 to check if the channels of the area channel section 66 have been checked. If the answer is "no," the program proceeds back to point 105 where the channels of the area channel section are scanned. The program then proceeds back to point 100. If the answer is "yes" at point 104, the program proceeds to point 106 to determine if a destination code 96 is present on the channel being received. If the answer is "no," the program branches to point 108 where the next channel in the area channel section 66 is scanned. The program proceeds from point 108 to point 100. If the answer is "yes" at point 106 that a destination code 96 is detected, the program proceeds to point 110 where a comparison is made between the transmitted destination code and any destination code which is stored in the channels of the area channel section 66. If the answer is "no" at point 110, the program proceeds to point 112 where the next channel within the area channel section 66 is received. If the answer is "yes" at point 110, the program proceeds to point 114 to compare the first digit of the paging receiver identification code transmitted on the channel frequency with the stored paging receiver identification code. If there is no match at point 114, the program proceeds to point 116 where the next channel of the area channel section 66 is scanned. If the answer is "yes" at point 114, the program proceeds to point 118 where the remaining digits of the paging receiver identification code are compared. If the answer is "no" at the comparison of any one of the remaining digits of the paging receiver identification code at point 118, the program proceeds to point 120 to scan the next channel of the area channel section 66. If the answer is "yes" at point 118, the paging receiver locks on the channel at point 122 by setting the phase lock loop 28 to continue to receive that channel and the following command is decoded by the operating program of the main CPU 24 and executed.
VII. Commands
An important part of the present invention is the command structure which permits the functionality of the paging receiver to be changed dynamically by the transmitter in a manner not achieved by the prior art. All commands which are executed by the main CPU 24 are sent according to a protocol. An example of the paging protocol is set forth below with a nationwide telephone number page to paging receiver IF 789 12345 with telephone number 424, 6464 and a warble tone. ##STR1##
The operating program of the main CPU 24 is programmed to respond to a command repertoire explained as follows. A command sequence immediately follows the pager receiver identification code and always begins with a tone "A" followed by the command tone. Set forth below is a command table explaining the command structure.
______________________________________COMMAND TABLE______________________________________A0 BATTERY SAVEA1 REPEATA2 PROGRAM IDA3 LOCAL & NUMERIC (16 NUMBERS)A4 LOCAL & MESSAGE - ALPHA (511 CHAR)A5 NATIONAL & NUMERIC (16 NUMBERS)A6 NATIONAL & MESSAGE - ALPHA (511 CHAR.)A7 ALPHA FIXED MEMORY LOCATIONA8 RESERVEDA9 EXT DATA (OPENS AUDIO TO EXIT JACK)AA DO NOT USE!AB OUT OF SERVICEAC CHANNEL PROGRAMAD SUBLOCAL PAGERS FROM RESTRICTED AREAS OR GROUPS OF PAGING RECEIVERSAE DO NOT USE!______________________________________
A0 Battery Save
The battery save command is followed by a two digit decimal format indicating how many seconds the paging receiver should sleep before beginning its channel sampling. It is followed by an AE message terminator with no tone alert necessary. The two digit number represents the number of 10 second increments to sleep with a maximum of 990 seconds (16.5 minutes).
A022AE=220 second sleep period
A099AE=990 second sleep period
A1 Repeat Page
The repeat command indicates that the page being sent is a repeat of the previous page. The previous message display will be used, and the numeric or alphanumeric page should match a previous page which has been stored in the random access memory 60 during the execution of the A3-A6 commands which cause a page to be stored in the random access memory. If a page match is detected by the paging receiver, the page is discarded. If the first page was not received, the page should be stored in the random access memory 60 and the wearer of the paging receiver alerted. The status display will show "RPT" indicating a repeat page and the first page was not found in memory, i.e.,
______________________________________A1, A3 424DE6464AE REPEAT 424-6464 (local, numeric,which is the execution of command A3 described below)______________________________________
A2 Program ID
The program ID command is used to send a new paging receiver identification code to the paging receiver. The previous paging receiver identification code will be overwritten by this command. No tone alert is necessary, but the paging receiver should display the new paging receiver identification code as a page, i.e.,
______________________________________CHANGE 789 12345 TO ID 789 45678A2789DE4567DE8AE (NEW ID)______________________________________
A3 Local and Numeric (16 Digits)
The A3 command sequentially illuminates the display 64' indicating the page is of local origin, and a numeric telephone number display as a page. This command is used by a local transmitter to transmit pages originating within the area identified by the area designation code. The main CPU 24 will receive and decode the paging single digit format i.e.,
______________________________________A3956DE1030AE TEL # 956-1030The maximum numeric message length is 16 digits.______________________________________
A4 Local and Message (Alphanumeric)
The A4 command sequentially illuminates the display 64' indicating the page is of local origin and an alphanumeric display as a page. The alphanumeric format is sent with each character being encoded as a two digit number 01-99 as explained above. The main CPU 24 will receive and decode the page in a two-digit format as discussed below. The message length will be 511 characters or less. This command is used by a local transmitter to transmit pages originating within the area identified by the area designation code 92.
The message length when in the alphanumeric mode will be 511 characters in length. The display will flash, indicating the message is 511 characters long, i.e., ##STR2##
A5 National and Numeric (16 Digits)
The A5 command sequentially illuminates the display 64' indicating that the origin of the page is not local and a numeric message as a page. This command is used by a local paging service, within the area identified by the area designation code, which relays a page to a transmitter located at a remote area where a paging receiver is to receive a page transmitted by the transmitter located at the remote area. The main CPU will receive and decode the page a single digit format, e.g.,
______________________________________TEL # 956 1001A6956DE10E1AE (NOTE: REPEAT DIGIT FOR SECOND ZERO)______________________________________
A6 National and Message (Alphanumeric)
The A6 command sequentially illuminates the display 64' indicating that the origin of the page is not local an alphanumeric message as a page. This command is used by a local paging service, within the area identified by the area designation code, which relays a page to a transmitter located at a remote area where a paging receiver is to receive a page transmitted by the transmitter located at the remote area. The page which is sent in a two digit decimal order with the number field being 01-99 in the same manner as explained above. The main CPU 24 will receive and decode the page in a two-digit format identical to the A4 command.
The maximum message length is 511 characters. The example is identical to the A4 command discussed above with the first two tones being A6.
A7 Alphanumeric Specific Message Memory
The A7 command permits a subset of commands to follow. The digit immediately following the A7 command will indicate in which section of addressable sections of the random access memory 60 to place the message. If a message exists in this memory location of the random access memory, it will automatically overwrite the message memory. The command subset will be 1-4 indicating memory locations 11-14. An ordinary message will not overwrite the 11-14 message locations. The message will immediately follow:
A7 1 (message location 11)
A7 2 (message location 12)
A7 3 (message location 13)
A7 4 (message location 14).
The message locations 11-14 will only be overwritten by messages with the same command (e.g. memory location 11 will only be overwritten by the A7 (1) command) or erased by the user. The message type will always be "Special Call" and will be sent as an alphanumeric message.
A8 Reserved
A9 External Data Message
The A9 command alerts the person being paged that the audio must be routed to the external data jack 67 for remote processing. The paging receiver will forward the audio to the external data jack 67 until the AE message is received, indicating end of data transmission, i.e. A9---DATA----AE.
AA Invalid
The AA command cannot be used, as it would be processed by the main CPU 24 as an AE (end of file) command.
AB Out of Service
The AB command will illuminate an out of service display on the memory section 68 of the display 64' and may or may not have numeric data following. This command may be used when system maintenance is required, or to alert the wearer of the paging service that service is being denied, until the bill is paid, i.e. ABAE (illuminates out of service message upon turn on and for two seconds).
The paging receiver still receives messages as normal. The out of range display turns on. The LCD display 64' displays "out of service" until the next page is allowed. The switching system will prevent any messages from being sent to the pager.
AC Channel Programming
The AC channel programming alerts the person wearing the paging receiver that channel frequency programming information is forthcoming. The frequencies are stored in the channel memory 62 transmitted as four digit decimals numbers, each separated by the DE delimeter. As explained above, up to 15 channels may be loaded into the area channel section 66 or the operation channel section 64. A preceding V indicates VHF, a U UHF, a J indicates Japan and an E indicates Europe.
When only one channel is desired, such as for local paging, the channel is repeated at least twice, to alert the paging receiver that only one channel is desired to be programmed in the area channel section 66 of the channels memory 62. All previous channel in the area channel section 66 of the channel memory 62 are erased. The memory cells have the new channel number entered to fix the paging receiver to receive a single channel. The memory cells will remain programmed until the next channel reprogramming of the paging receiver, i.e.
__________________________________________________________________________AC0123DE0123AE (CH.V 123 NO SCANNING)AC0E10DE0107DE0210DE1050DE7AEA (CH.v10,v107,u210,u50).__________________________________________________________________________
The channel programming sequence is as follows:
______________________________________0001 - 0DDD VHF 5 KHz steps1001 - 1DDD VHF 6.25 KHz steps (Europe)2001 - 2DDD UHF 5 KHz steps3001 - 3B2B 280 MHz 2.5 KHz steps (Japan).______________________________________
Channel codes 4001, 5001, 6001, 7001, 8001, 9001 are open for additional channels to be added. The total upward reserve channel capacity in ROM 58 is 16,458 channels.
The following sub-commands are utilized for instructing the main CPU 24 to perform functions pertaining to the programming of channels.
NO Command (Add One Channel)
When no sub-command is sent, one channel is to be added to the area channel section 66. e.g. AC 0237 DE 7AEA (add VHF channel 237 to area channel section 66).
Sub-command 4000 (Typically Regional)
When 4000 is transmitted, it erases the entire area channel section 66 and the operation channel section 64 of the channel memory 62 and cannot be used in adjacent areas which must be programmed with the 6000 sub-command. e.g. AC 4000 DE 0156 DE 2132 DE 7AEA. This command erases and stored VHF 156 and UHF 132 channel frequencies in the area channel section.
Sub-command 5000
When 5000 may transmitted, the desination code is programmed. This command erases the operating channel 64 and the area channel section 66 and forces the reception of a particular channel. The command is used for dynamic frequency agility. The paging receiver is fixed to receive a fixed channel. e.g. AC 5000 DE 0171 DE 7AEA. This command erases the operating channel 64 and the area channel section 66 and forces the paging receiver to VHF channel 171, causing the operating channel section 64 to store VHF channel 171.
Sub-command 6000 (National)
This command is divided into the loading of the 15 possible destination codes 96 and the channel.
__________________________________________________________________________ACB6122DE0200 DE0000 DE0000 DE0000 DE0212 DE0311DE0408DE2511 DE2139 DE7AEA__________________________________________________________________________
This represents the 6000 national command followed by the destination code 96 or local code for each of the 15 possible channels in the area channel section. The five channels follow and will be as follows:
______________________________________6122 National, channel 1 = A, channel 2 = B, channel 3 = B0200 Channel 4 = local, channel 5 = B, filler code0000 Channel 8 = 11, filler code0000 Channel 12-15, filler code0212 VHF channel 2120311 VHF channel 3110408 VHF channel 4082511 UHF channel 5112139 UHF channel 1397AEA Stop channel command.______________________________________
Channel Programming Termination (7AEA)
The channels to be sent to the paging receiver are sent in the following order:
______________________________________0XXX channels (VHF) (ascending numerical order)1XXX channels (VHF Europe)2XXX channels (UHF Europe)3XXX channels (280 MHz).______________________________________
The last channel sent is actually a terminate message code. It is 7AEA (7AAA).
The paging receiver will receive the last frequency code and immediately terminates the page. The 7AEA terminate frequency code is necessary at the end of every AC channel program message. During the transmission of channel codes, the AEA code may appear (e.g. channel 1AEA). In order to prevent termination of the message, the AC command changes the AEA termination command to 7AEA. 7AEA is an invalid channel code.
AD Company COMMAND
The AD command allows a 32 alphanumeric character company message to be sent to the paging receiver. The message is always alphanumeric, e.g., AD 4247, DE 4637, DE 5100, DE 4833, DE 3941, DE 4639, AE Jones Paging.
When a company message is desired, it will be sent after the paging receiver identification code has been programmed. When the paging receiver is turned on, the company message will be displayed instead of a self test message which is typically used. If no company message resides in the paging receiver, the self test message will display.
The 32 character part of the random access memory 60 is battery protected to permit the message to permanently reside in the paging receiver. It may be changed by simply sending a new AD command and message to the pager. This permits the company message to be changed at will.
AE - Invalid
The AE command cannot be used, as it cannot be encoded and also conflicts with the end of file command.
End Of Page Command AE or AEA
All pages require the end of page command. The end of page command serves a two fold purpose indicating the end of transmission and determines the type of tone alert.
AE=2041 hertz--50% duty cycle--2 seconds
AEA=2041 hertz--25/75% duty cycle--2 seconds.
Certain commands do not send a tone alert. A listing of the commands is as follows:
______________________________________A0 BATTERY SAVE (NO ALERT)A1 REPEAT (NO ALERT) *A2 PROGRAM ID (ALERT) - DISPLAY IDA3 LOCAL & TEL NUMERIC (ALERT)A4 LOCAL & SP ALPHA (ALERT)A5 NAT. & TEL NUMERIC (ALERT)A6 NAT. & ALPHA (ALERT)A7 ALPHA FIXED MEMORY (ALERT)A8 UNASSIGNED (ALERT)A9 SPECIAL & DATA AUDIO (ALERT)AB OUT OF SERVICE (ALERT)AC CHANNEL PROGRAM (ALERT)AD COMPANY MESSAGE (ALERT).______________________________________ * AL will alert if first page was not received or if previously erased.
VIII. Remote Area Paging
FIG. 21 illustrates the operation of the present invention in receiving pages at a remote area. A local transmitter 130 transmits one or more channel programming commands as described above which specify one or more channels on which a paging receiver 132 is to receive pages while located at a remote area. The channel programming commands are received by the paging receiver 132 while it is located in transmission distance of the local transmitter 130. Theone or more channel programming commands specifying the one or more channels to be received in the remote location also include the destination code 96 described above used to differentiate pages to be received by the paging receiver 132 while in the remote are from pages originating in the remote area on the same one or more programmed channels. The paging receiver 132 is transported to the remote area as indicated by the downwardly pointing vertical arrow in the right-hand portion of FIG. 21. The downwardly pointing vertical arrow in the left-hand portion of FIG. 21 illustrates the relaying of a page originating at the local area or delayed through the local area to a remote transmitter 134 located in the remote area where the page is transmitted by transmitter 134 and received by the paging receiver 132. The remote transmitter 134 sequentially in time transmits the destination code as the first character which is transmitted, the paging receiver identification code digits in an order of increasing significance and the actual page. The paging receiver 132 while in the remote area compares the first digit of each transmission on the one or more channels that the paging receiver is programmed to receive with the stored destination code. If there is a match between the first character transmitted with a page on the one or more channels that the paging receiver 132 is programmed to page and the destination code, the paging receiver 132 compares the subsequent digits of the transmitted paging receiver identification code following the destination code in an order of increasing significance with the stored paging receiver identification code digits. The RF tuner 16 of the paging receiver is immediately turned off upon a mismatch of either the destination code or one of the digits of the transmitted and stored paging receiver identification code. If the transmitted and received destination codes and paging receiver identification codes match, the page is displayed on the display 64. It should be noted that pages originating in the remote area will not cause the RF tuner 16 to be turned on past the point in time of transmission of the destination code because of the mismatch which will occur thereby saving the battery of the paging receiver.
A method of the present invention in paging a sublocal area within an area or a group within the local area such as a company is as follows. The paging receiver is programmed with the channel programming command to receive one or more channels. The destination code is used in the same manner as described above with regard to FIG. 21 in identifying pages to be received in a remote area except that it is assigned to paging receivers within part of the local area (subarea) or to paging receivers belonging to a group such as a company. The destination code is transmitted with the channel programming command to identify one or more channels on which pages on a sublocal or a group level are to be detected. Thereafter, the paging receiver which has been programmed to receive on the programmed one or more channels on a sublocal or a group basis compares the first digit of each transmission occurring on the one or more programmed channels to detect if there is a match between the destination code stored in the channel memory 62 and the first character which is transmitted. If there is no match, the RF tuner 16 is immediately shut off thereby saving the battery of the paging receiver. If there is a match, the paging receiver compares the transmitted digits of the paging receiver identification code in an order of increasing significance with the stored paging receiver identification code digits. If there is a mismatch between any one of the paging receiver stored and transmitted paging receiver identification code digits, the RF tuner 16 is immediately shut off. If there is a complete match between the destination code and the stored and transmitted paging receiver identification code digits, the paging receiver processes the subsequently transmitted page. Thus, it is seen that paging receivers may be programmed on a sublocal or on a group specific basis within a local area to receive pages on channels which are in widespread use in a local paging system while achieving battery savings by not turning on the paging receiver to receive subsequent digits of the paging receiver identification code for every transmission occurring on the programmed channels.
IX. FIGS. 7-20
As has been explained above, FIGS. 7-20 illustrate circuit schematics for implementing the blocks of FIG. 1. Integrated circuits are identified by their industry designation. It should be understood that other implementations of the blocks of FIG. 1 may be utilized in practicing the present invention.
X. Appendix
Each line of the hexadecimal code listing in the Appendix contains the following information as explained from left to right. The first two characters identify the start of a line which are "S0", "S1" or "S9". The two characters following the start of line characters are a hexadecimal representation of the number of bytes following on the line. The following four characters are a starting address in memory for the code following thereafter. The final two characters are a check sum for error correction purposes.
While the invention has been described in terms of its preferred embodiments, it should be understood that numerous modifications may be made thereto without departing from the spirit and scope of the invention as defined by the appended claims. It is intended that all such modifications fall within the scope of the appended claims. ##SPC1##
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A paging receiver is disclosed which is compatible with transmissions from analog or digital paging transmitters. The paging receiver has a command structure which permits it to be dynamically programmable to change its functionality including programming of the channels which the paging receiver is to receive. The programmability of the channels permits the paging receiver to be used for making national, regional, remote area, local area, and sublocal area pages, and pages to a group in the local area and to switch from channels which are heavily used during peak paging times to lesser used channels. The paging receiver transmits paging receiver identification code digits in an order of increasing significance which significantly lessens power consumption for all paging receivers tuned to a particular channel for determining if a page is to be received which prolongs paging receiver battery life. The paging receiver displays the place of origin of pages as either being of local origin or from other areas. The paging receiver antenna is continuously tunable to permit compensation for variation in antenna gain caused by environmental factors which can seriously degrade signal strength.
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REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 08/868,499 filed Jun. 4, 1997, now U.S. Pat. No. 5,879,323 issued Mar. 9, 1999, which is a divisional of allowed U.S. patent application Ser. No. 08/646,853 filed May 8, 1996 now U.S. Pat. No. 5,767,648.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the transdermal electrokinetic mass transfer of medication into a diseased tissue, and, more specifically, to a portable apparatus for the iontophoretic delivery of medication across the skin and incorporation of the medication into diseased tissues and blood vessels adjacent to the delivery site. The apparatus provides a new method for treating and managing diseases presenting cutaneous lesions.
2. Prior Art
Iontophoresis has been employed for several centuries as a means for applying medication locally through a patient's skin and for delivering medicaments to the eyes and ears. The application of an electric field to the skin is known to greatly enhance the skin's permeability to various ionic agents. The use of iontophoretic transdermal delivery techniques has obviated the need for hypodermic injection for many medicaments, thereby eliminating the concomitant problems of trauma, pain and risk of infection to the patient.
Iontophoresis involves the application of an electromotive force to drive or repel oppositely charged ions through the dermal layers into a target tissue. Particularly suitable target tissue include tissues adjacent to the delivery site for localized treatment or tissues remote therefrom in which case the medicament enters into the circulatory system and is transported to a tissue by the blood. Positively charged ions are driven into the skin at an anode while negatively charged ions are driven into the skin at a cathode. Studies have shown increased skin penetration of drugs at anodic or cathodic electrodes regardless of the predominant molecular ionic charge on the drug. This effect is medicated by polarization and osmotic effects.
Regardless of the charge of the medicament to be administered, a iontophoretic delivery device employs two electrodes (an anode and a cathode) in conjunction with the patient's skin to form a closed circuit between one of the electrodes (referred to herein alternatively as a "working" or "application" or "applicator" electrode) which is positioned at the delivered site of drug delivery and a passive or "grounding" electrode affixed to a second site on the skin to enhance the rate of penetration of the medicament into the skin adjacent to the applicator electrode.
Recent interest in the use of iontophoresis for delivering drugs through a patient's skin to a desired treatment site has stimulated a redesign of many of such drugs with concomitant increased efficacy of the drugs when delivered transdermally. As iontophoretic delivery of medicaments become more widely used, the opportunity for a consumer/patient to iontophoretically administer a transdermal dosage of medicaments simply and safely at non-medical or non-professional facilities would be desirable and practical. Similarly, when a consumer/patient travels, it would be desirable to have a personal, easily transportable apparatus available which is operable for the iontophoretic transdermal delivery of a medication packaged in a single dosage applicator. The present invention provides a portable iontophoretic medicament delivery apparatus and a unit-dosage medicament-containing applicator electrode which is disposable and adapted for use with the apparatus for self-administering medicament.
SUMMARY OF THE INVENTION
The present invention discloses a portable iontophoretic transdermal or transmucoscal medicament delivery apparatus and a unit dosage medicament applicator electrode adapted for use with the apparatus for the self-administration of a unit dose of a medicament into the skin. The apparatus is particularly suited for the localized treatment of herpes infections. Recurrent herpetic infections (fever blisters or herpes labialis) are very common and usually involve the mucocutaneous juncture. The established treatment for recurrent herpetic lesions (oral or genital) has been primarily supportive; including local topical application of anesthesia. Severe cases have been treated with systemic Acyclovir® (Zovirax Burroughs-Wellcome). Some cases the condition is managed with prophylactic long-term dosing administration with a suitable antiviral agent at great expense. Systemic treatment of acute herpetic flare-ups may reduce the normal 10-12 day course of cutaneous symptoms into a 6-8 day episode. Topical treatment of lesions with Acyclovir® has not been as effective as in vitro studies would suggest. A compound which is not presently available to clinicians but has demonstrated significant anti herpetic activity is 5-iodo-2 deoxyuridine (IUDR). Both of those agents have shown limited clinical efficacy when applied topically to the herpetic lesion. It is the present inventor's contention that the limited efficacy of topical administration previously observed is, at least in part, due to the poor skin penetration of these medicaments when applied topically. The present invention provides improved transdermal delivery of these medicaments and demonstrates improved clinical results in the case of Herpes.
Oral Herpes (most commonly Herpes simplex I infection) as well as genital Herpes (usually Herpes Simplex II infection) afflict many people, cause discomfort, shame, and may contribute to more severe and costly illnesses such as cervical cancer, prostate cancer, and perinatal blindness from herpetic conjunctivitis. The present invention discloses a portable, user-friendly transdermal delivery device and a method for using the device with Acyclovir® (or similar antiviral agent) to greatly benefit these afflicted patients. The present inventor has constructed embodiments of this device and conducted human clinical trials which clearly demonstrate improved therapeutic efficacy using iontophoretically administered antiviral agents when compared to unassisted topical application of the agent.
It is an object of the present invention to provide an iontophoretic medicament delivery apparatus which is portable and operable for self-administration of medicament into the skin of a person.
It is another object of the present invention to provide an improved iontophoretic transdermal drug delivery apparatus having a medicament-containing application electrode which disperses a single dosage and is disposable and non-reusable.
It is a feature of the present invention that the iontophoretic medicament delivery apparatus is easily maneuverable and operable when hand-held.
It is another feature of the present invention that the iontophoretic medicament delivery apparatus is battery powered and conveniently transported by a person.
It is a further feature of the present invention that the iontophoretic medicament delivery apparatus employs a tactile electrode which is in electrical contact with the skin of a user's hand when the apparatus is held in the user's hand, obviating the need for a separate grounding electrode connector or wire.
It is still another feature of the present invention that the iontophoretic medicament delivery apparatus is adapted to be operable with a disposable medicament containing applicator electrode which applicator electrode includes an absorbent, inert, non-corrosive portion containing a therapeutic agent.
It is yet another feature of the present invention to provide an embodiment of an iontophoretic transdermal delivery device wherein the disposable iontophoretic medicament-containing applicator electrode is adapted for releasable attachment to use with a hand-held base assembly housing a grounding electrode.
It is yet another feature of the present invention that the disposable iontophoretic medicament applicator electrode include indicator means operable for enabling a user to determine when the medicament within the removable applicator electrode has been released in delivery and/or depleted.
It is yet another feature of the present invention that the circuitry employed in the disposable iontophoretic medicament applicator include current limiting means operable for limiting the electrical current flowing between the surface of the applicator and the skin to less than about one milliampere per square centimeters of application electrode skin-contacting, surface.
It is another advantage of the present invention that the iontophoretic medicament delivery apparatus employs a disposable application electrode which conducts the electrical current to the tissue through the solution in which the medicament is dissolved.
It is still another advantage of the present invention that the improved disposable iontophoretic medicament applicator is inexpensive, safe to use, substantially unitary in construction and greatly increases the therapeutic efficacy of a medicament administered thereby.
The apparatus in accordance with the present invention provides a means for topically administering medicament directly and with, high efficiency into a diseased tissue thereby providing a novel method for treating clinical conditions presenting mucocutaneous symptoms and particularly mucocutaneous Herpes Simplex viral eruptions and sequelle associated therewith.
In one embodiment the electrode comprises a unitary flexible strip (such as SILASTIC®- by Dow Corning) having perforations dimensioned to accommodate a medicament placed therein. The perforations or "cells" can be made to store and dispense gels, ointments, fluids and other medicament vehicles without requiring the reformulation of the either the medicament or the vehicle.
The above objects, features and advantages of the invention are realized by the improved monopolar iontophoretic, medicament applicator which is easily transportable. The applicator employs a detachable medicament containing application electrode. The objects, features and advantages of the invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when it is taken in conjunction with the accompanying drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational plan view of the iontophoretic medicament delivery apparatus showing the circumferential tactile ground electrode on the outer surface of the base housing and a disposable iontophoretic application electrode;
FIG. 2 is a side elevational view of the disposable non-reusable iontophoretic application electrode with a portion broken away to view the medicament dose packet;
FIG. 3 is a top view of a medicament dispensing electrode adapted for use with an iontophoresis handpiece.
FIG. 4 is a side elevational exploded view of the medicament dispensing electrode of FIG. 3.
FIG. 5 is a perspective view illustrating the medicament dispensing electrode of FIGS. 3 and 4 attached to an iontophoresis handpiece in preparation for use.
FIG. 6 is a perspective view illustrating a patient preparing to self-administer medicament to lesions adjacent to the mouth employing the iontophoretic electrode/handpiece delivery system in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows, in side elevation, a preferred embodiment of the hand-held iontophoretic transdermal medicament delivery apparatus of the present invention. The apparatus, indicated generally by the numeral 10, has an elongate base assembly 11 the major portion of which is preferably formed of plastic and shaped to conform to and comfortably fit within a users hand. An applicator electrode module 12, containing a unit dose of medicament 23, is releasably attached to a applicator electrode receptacle 14 on the distal end of the base assembly 11. The application electrode 12 is preferably a "clip-on" type of electrode similar in configuration to an electrocardiogram electrode. In the drawing presented in FIGS. 1 and 2, electrically conductive elements such as wires and busses are presented as heavy lines. A wire 16 provides electrical connection between the applicator electrode receptacle 14 and wire 1 within the neck 15 of the base assembly 11. Connecting wire 18, in turn, provides electrical connection between the wire 16 and the current driver unit 19 housed within the base assembly 11. A conductive tactile electrode 20 forms a portion of the exterior skin-contacting surface of the base assembly 11 preferably circumferentially enclosing a portion of the base housing or it may be interrupted or discontinuous on the outer surface. The tactile electrode 20 is in electrical communication with the cathode 24C of battery 24 by means of a buss 17 and conductive urging spring 25 which secures the battery in position within the base assembly 11. For the self-administration of medicament a user must have. skin contact with the tactile electrode 20 for the unit to operate. Current driver 19 underlies the cathodic (ground) tactile electrode 20 and is electrically connected via wire 21 to a voltage multiplier 22. The voltage multiplier 22 receives low voltage power from the anode 24a of the battery power source 24 and increases the available voltage for presentation to the application electrode 12. The battery 24 is preferably a size AA or AAA. Battery 24 is held in place by an electrically conductive biasing spring 25 and ensures that electrical power is available at the application electrode 12 when the user grasps and holds the base housing 11 of the apparatus 10 thereby touching the cathodic tactile electrode 20. The application electrode 12 and the tactile electrode 20 thus form a closed circuit in series with the user's skin.
When current flows across the user's skin to the application electrode in response to an applied voltage the current promotes and hastens the penetration of the medicament 23 contained in a reservoir 26 within the working electrode 12 into the skin. The polarity of the working electrode 12 is preferably unidirectional to promote the above described penetration without requiring a separate grounding electrode. The working application electrode 12 will be described in greater detail below.
The base assembly 11 of apparatus 10 serves as a housing to the aforesaid components as a handle. The portion of the base assembly 11 exclusive of the tactile electrode, is preferably made of a plastic such as polyethylene, acrylonitrile, butadiene, styrene or similar durable plastic. The battery portion 24 is connected to a voltage multiplier 22 which steps up the voltage supplied by the battery 24 and applies the stepped up voltage to the current driver 19. Current driver 19 presents a defined current and voltage output at the application electrode 12 the value of the current, which may be empirically determined being sufficient to drive the medicament through the porous, open-celled material 27 (FIG. 2) within the application electrode interposed between the skin contacting surface 13 and reservoir 26 containing the unit dose medicament and penetrate the patient's skin. The circuitry limits the maximum current available to the application electrode to preferably to less than about one milliampere per two square centimeters of the skin-contacting surface area 13 of the application electrode 12. However, depending upon working electrode's 12 skin-contacting surface 13 configuration, the current level can vary from about 0.1 to about 1.2 milliamps. Currents ranging between 0.1 ma to 5 ma have been used clinically by the present inventor, but the higher currents caused the user minor discomfort and, with chronic use over time, may produce untoward effects.
FIG. 2 shows a preferred embodiment of the iontophoretic medicament-containing application electrode 12. The application electrode 12 is preferably disposable and non-reusable and is suitable, for example, for transdermally delivering antiviral agents such as Acyclovir® for the treatment of cold sores or genital herpes. The size of the skin-contacting surface 13 of application electrode 12 may vary to accommodate specific clinical applications. The application electrode 12 is detachably housed within a recess within the receptacle 14 which recess presents an electrically conductive interior surface to complete the electrical flow path from the connecting wires 18 and 16 to a conductive element 29 within the application electrode. The electrical current from the current driver 19 is conducted through conductive inner surface of the application electrode receptacle 14 to the electrically conductive element 29 within the applicator electrode which element 29 is in electrical contact with the inner surface of the receptacle in contact therewith to drive the medicament 23 or treatment agent through the open-celled sponge-like matrix material 27 and through the user's skin (not shown). The medicament or treatment agent 23 is contained within a rupturable polymer reservoir 26 until dispensed during treatment. A slight exertion of pressure or squeezing of the reservoir 26 against reservoir puncture means 28 releases the medicament or treatment agent into an open-celled sponge-like material 27 within the application electrode for iontophoretic delivery into the patient's skin. Medicament 23 release can occur at the time of application or upon peruse compression of the electrode 12. Application electrode 12 can be advantageously designed to include a stripping portion adapted so that upon removal of the application electrode 12 from the electrode receptacle 14 a protruding stripping portion (not shown) scrapingly strips the conductive coating from the conductive support arm 29 to prevent reuse of the disposable electrode 12. Application electrode 12 is intentionally packaged with a single dose packet or reservoir 26 of treatment agent or medicament 23. In addition to the medicament, the reservoir 26 can include a coloring agent, such as iodine, which turns dark blue upon contact with starch in the open-celled material to visibly indicate that the unit dose encapsulation has been used. Other suitable coloring agents can include pH indicators, wet saturation indicators or oxidizable pigments.
The open-celled sponge-like material 27 surrounding reservoir 26 should be inert to the medicament or treatment agent being employed, as well as being non-corrosive and stable when in contact with the treatment agent. Suitable materials include plastic pads, such as polyethylene, paper or cotton, porous ceramics, open-celled porous polytetrafluoroethylene, polyurethane and other inert plastics, and open-celled silicone rubber, such as may be employed with vertically aligned medicament-containing tubes. A typical medicament that can be contained within the rupturable polymer reservoir 26 is xylocaine or similar topical anesthetic.
The disposable electrode 12 possesses the advantages of preventing leaching or migration of the medicament from within the rupturable polymer reservoir, no attendant loss of efficacy, a long shelf life and little or no electrode corrosion. A suitable electrical control circuit for use in the iontophoretic medicament delivery apparatus 12 is shown in U.S. patent application, Ser. No. 07/579,799, filed Sep. 10, 1990, now U.S. Pat. No. 5,160,316 and hereby specifically incorporated by reference herein in pertinent part.
FIG. 3 shows a particularly preferred embodiment of a disposable, one-time use electrode 30 for use with the iontophoresis handpiece 10 of the present invention. FIG. 3 is a top view of the disposable electrode 30 with the upper release film 41 (FIG. 4) removed. A non-conductive substrate 31 is formed into a flat strip having a central portion A and two end portions B. The end portions B each have a cut-out therein containing an electrically conductive gel 32. The gel 32 may be imbedded within a mesh or it may be constrained within the cut out by means of a porous, non-wicking and non-electrically conducing containment layer 34 and 35 much as tea is contained within a porous tea bag. The central portion A of the strip 31 has a medicament-containing reservoir 33 therewithin. The medicament-containing reservoir 33 may comprise a suitable medicament embedded within the mesh of a pharmacologically inert material. The medicament-containing reservoir 33 is positioned between die cuts 36 in the non-conductive substrate 31 which die cuts provide means for facilitating the predictable bending the electrode strip 30 to matingly conform to the shape of the exterior surface of an iontophoresis handpiece 10 (FIG. 1). Magnets 43 and 43' (shown in phantom in FIG. 3) disposed laterally to the central portion A provide means for magnetically activating a handpiece when the electrode is in position.
An exploded side view of the electrode 30 is shown in FIG. 4. The conductive gel 32 filling the cut-outs may be contained within a mesh or may be contained within the cut-out by means of porous, non-wicking layers 34 and 35. Similarly, the medicament-containing cut-out 33 may comprise the medicament embedded within a mesh, a gel, or similar substrate which releases the medicament in response to an electrical communication therewith. The upper containment layer 34 and the lower containment layer 35 serve to restrain the conductive gel within the medicament reservoir 33 to their respective cut-outs. An upper release film 41 is used to protect the adhesive surface (not shown) on the uppermost surface of the containment layer 34. A lower release film 42 serves a similar function to protect the adhesive surface of the lower medicament containment layer 35. The cut-outs 36 are shown to penetrate the strip of non-conductive material 31 adjacent to the medicament-containing reservoir 33. It is particularly desirable to provide one or more activating magnetic bodies 43 and 43' within the strip 31 in order to properly position the electrode strip 30 and activate the handpiece 10. Since it is anticipated that the handpiece/electrode assembly of the present invention will most likely be used in the bathroom, it is particularly desirable to hermetically seal the handpiece's internal operational mechanisms. The on/off switch within the handpiece can be in the form of a magnetically responsive switch which is turned "on" and "off" in response to the position of the electrode.
Turning now to FIG. 5, we see a disposable electrode 30 in the process of being applied to the terminal end of an iontophoresis handpiece 10. The electrode 30 is applied to the active terminal 16 of the handpiece in such a manner that the medicament-containing reservoir 33 overlies and is in electrical contact with the active terminal 16 of the handpiece 10. The conductive gel layers 32 are positioned on the handpiece to overly the ground electrode on the handpiece 10. The ground electrode is indicated at 20 in FIG. 5.
An alternate but equally effective embodiment of FIG. 4 electrode can be manufactured from a mold injected soft, inert material, non-conductive and non-porous (such as SILASTIC®- by Dow Corning) in the shape embodied in FIG. 3. The unit will contain vertically aligned open cells for containing and acting as reservoir for therapeutic medicaments as well as a conductive gel (if necessary). Such an embodiment is less costly to produce and avoids the process of assembling numerous layers.
The iontophoresis handpiece and electrode assembly in accordance with the preferred embodiment shown in FIGS. 3 and 4 is shown being used by a patient 60 in FIG. 6. The patient 60 grasps the handpiece by means of placing a finger 61 on at least one of the conductive gel ground electrodes thereby grounding the patient's body. The active electrode driver 19 of the handpiece is in electrical communication with the medicament-containing reservoir 33. The medicament-containing reservoir 33, thus positioned and grasped by the patient, is advanced to come in contact with a lesion 63 on the patient's skin. Upon contact, electrical current flows between the active electrode 19 in the handpiece to the ground electrode(s) 32 via passage through the medicament-containing reservoir 33 comprising the active electrode. The polarity of the current may be reversed to accommodate the charge on the medicament. The flow of an electrical current facilitates entry of the medicament within the reservoir 33 into the skin overlying the lesion 63 thereby locally delivering the medicament to the exact area to be treated.
EXPERIMENTAL CLINICAL TRIALS
The inventor has conducted a clinical study using a prototype iontophoretic device in accordance with the present invention for the treatment of cold sores. The clinical response was promising. A second independent, qualified investigator, a board-certified Urologist, conducted a study using the present apparatus and method for treating male genital herpes lesions with encouraging results. Table 1 summarizes data (discussed below) supporting the claim to unexpected clinical benefits treating disease with this novel method. The method and medicament application device when used together for treating these common, embarrassing, and previously not easily-treatable ailments provide surprising advantages.
The embodiment of the device shown in FIG. 1 and described hereinabove is a improvement over the prototype used in the clinical study, which was a larger unit, not user friendly, which required physically connecting wires to the patient's body which created anxiety, and could not be used without attending personnel. Notwithstanding design, the apparatus used in the clinical study summarized in Table 1 employed electronics similar to the apparatus described herein and was used to optimize the clinical performance of the embodiment 12 of the device described herein.
TABLE 1______________________________________STAGE I TREATMENT RESULTSRESPONSE IUDR ACYCLOVIR ® TOTALS______________________________________No response 1 1 2Some response 1 3 4Major response 26 42 68______________________________________
The study included a control situation wherein seven patients were found who had simultaneous concurrent herpes lesions at separate locations on their bodies. In each case one lesion was treated with iontophoretic application of antiviral agent (Acyclovir® or IUDR) and the other lesion was treated in the standard method employed in the prior art comprising repeated topical application of the same antiviral agent. The iontophoretically enhanced treated lesion received a single 10-15 minute treatment. All iontophoretically treated lesions demonstrated resolution in 24 hours and none of the unassisted topically treated lesions demonstrated a similar response. The results for the control group are summarized in Table 2.
TABLE 2______________________________________CONTROL GROUP RESULTS No response Some resp. Major resp.______________________________________IUDRTreated lesion 0 0 7Control lesion 5 2 0ACYCLOVIR ®Treated lesion 0 0 1Control lesion 1 0 0______________________________________
The clinical studies included patient volunteers with full informed consent who suffered from recurrent cold sores. The study demonstrated greatest treatment efficacy if the herpes lesion received iontophoretic treatment within 36 hours of lesion onset. The treatment incorporated an electrode saturated with Acyclovir® ointment (ZOVIRAX®) or IUDR (STOXIL®) Ophthalmic drops as supplied by the manufacturer. Thus mounted Anodic electrode of the prototype system was used for a 10-15 minute application directly to the lesion with the average current setting of 0.2 ma-0.6 ma which was well tolerated by all patients.
The lesion was evaluated in 24 hours. In 92% of the iontophoretically treated cases (>70 lesions treated) a major response was noted. A major response was categorized by resolution of pain in <6 hours and lesion crusted and healing within 24 hours. The normal course of cold sores involves an average period of 10-12 days before resolution and healing occurs. The present apparatus and clinical method for treatment of mucocutaneous Herpes Simplex (type I and Type II) eruptions presented herein have been described and performed with excellent results. This novel user friendly apparatus in combination with the disclosed clinical treatment method presents a very effective new treatment for Herpes Simplex eruptions.
While the invention has been described above with references to specific embodiments thereof, it is apparent that many changes, modifications and variations in the materials, arrangements of parts and steps can be made without departing from the inventive concept disclosed herein. For example an impregnated conductive gel can also be used to as medicament containing medium to increase the physical stability and the tissue adhering characteristics of the electrode. Accordingly, the spirit and broad scope of the appended claims is intended to embrace all such changes, modifications and variations that may occur to one of skill in the art upon a reading of the disclosure. All patent applications, patents and other publication cited herein are incorporated by reference in their entirety.
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A portable iontophoresis apparatus for facilitating delivery of medication across the cutaneous membrane into adjacent underlying tissues and blood vessels. The apparatus employs a modular, detachable non-reusable medicament-containing applicator electrode which is adapted to attach to a base assembly. The apparatus is designed to be hand-held and includes a circumferential tactile electrode band on the base assembly which provides electrical connection between the skin of the user's hand and one pole of a bipolar power source housed within the base assembly. The opposing pole of the power source is connected to the applicator electrode. The user's body completes the electrical circuit between the applicator and tactile electrodes. A method for using the device for the treatment of Herpes simplex infection and related viral infections which produce similar cutaneous lesions is presented. The apparatus, when used in accordance with the method described herein, demonstrated >90% treatment efficacy in clinical trials.
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BACKGROUND OF THE INVENTION
This invention relates to a three-wheeled stroller and particularly to a foldable three-wheeled stroller.
Foldable strollers with four wheels are known in the art. FIG. 1A and 1B show a foldable three-wheeled stroller which is disclosed in U.S. patent application Ser. No. 397,688 filed by the applicant of the present invention now U.S. Pat. No. 4,934,728. The stroller can be folded by turning the front fork member rearward to place the front wheel between the rear wheels. However, it has been found that the stroller is unsatisfactory because the size of the stroller does not decrease sufficiently when folded.
SUMMARY OF THE INVENTION
An object of the invention is to provide a stroller with an improved construction which can minimize the size of the folded stroller.
Another object of the invention is to provide a stroller with an improved construction which includes a a three-wheeled base frame on which is mounted a foldable elongated U-shaped tube and a pair of rear support tubes.
According to the present invention, a foldable stroller comprises: a base frame having a fork portion; a front wheel attached to the fork portion; two rear wheels detachably connected to the rear end of the base frame; first means for detachably connecting the rear wheels to the rear end of the base frame; an elongated U-shaped support tube having two arm tubes which have lower ends detachably connected to the sides of the base frame, the arm tubes being bent to incline rearward; a second means for detachably connecting the lower ends of the arm tubes to the base frame; a pair of rear support tubes having lower ends pivotally connected to the sides of the base frame, said rear support tubes having upper portions bent forward and pivotally connected to the arm tubes of the U-shaped support tube, the rear support tubes further having a transverse connecting rod member extending therebetween; and a seat assembly mounted on the U-shaped support tube.
The present exemplary preferred embodiment will be described in detail with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B show a foldable stroller known in the art;
FIG. 2 is a perspective view of a stroller according to the present invention;
FIG. 3 is an exploded view of the stroller of FIG. 2;
FIG. 4 is a perspective view of the stroller after being folded; and
FIG. 5 is a perspective view of the stroller with the rear wheels being detached.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 2, and 3, a stroller incorporating the present invention includes a base frame 10, a front wheel 12, a footrest plate 13, a mudguard 14, two rear wheels 20, two rear support rods 30, a U-shaped front support tube 50, a seat assembly 70 and a canopy assembly 90.
The base frame 10 is elongated from the front end to the rear end thereof. The frame 10 is constituted of two tubes 10a which are bent at their front portions so that they converge forward and then constitute a fork-like part to hold the front wheel 12. Front ends 11 of the tubes 10a are forked and respectively fixed to two ends of a shaft 120 of the front wheel 12. A footrest plate 13 is welded to the tubes 10a. The front end of the footrest plate 13 has a curved notch 130 and is connected to a mudguard 14 near the notch 130. A transverse tube 18 is fixed to the rear ends of the tubes 10a to carry the rear wheels 20. Two holes 180 are provided in the tube 18 near the two ends thereof. A shaft pin 21 has a portion fixed in a hollow shaft of each wheel 20. Each wheel 20 is attached releasably to each end of the tube 18 by inserting the projecting portion of the shaft pin 21 into the tube 18 and fastening the same to the tube 18 by means of a detachable lock pin 22. The lock pin 22 has a pull ring 221 and a resilient projection 222, and is inserted into the tube 18 through the hole 180 of the tube 18 and the hole 210 of the shaft pin 21 until the pull ring 221 abuts the wall of the tube 18. The resilient projection 222 prevents the lock pin 22 from moving out of the tube 18. The pull ring 221 is used to pull out the lock pin 22 from the tube 18.
The two rear support rods 30 are interconnected by a transverse rod 40. Each rear support rod 30 has an L-shape. The lower end of each rod 30 is movably attached to each tube 10a with a screw 19. The top end of each rod 30 extends forward and is movably fastened to each arm tube 50a of the U-shaped support rod 50 by means of a screw assembly 54 which permits movement of the arm tube 50a and the rod 30.
The arm tubes 50a are bent at their lower sides and the lower ends 51 thereof are forked and detachably connected to the tubes 10a. The detachable connection is accomplished by using internally threaded hollow members 150 which are inserted in and welded to the tubes 18 to receive headed screw members 16 which screw the lower ends of the arm tubes 50a to the tubes 18. The headed screw members 16 can be easily detached from the threaded tubes 150. The upper portion of the U-shaped tube 50 is separable from the arm tubes 50a and serves as a handle 60. The handle 60 is telescopically connected to the arm tubes 50a and is provided with a plurality of adjustment holes 62. Holes 55 are provided in the arm tubes 50a in alignment with a black support rod 58. The height of the handle 60 can be adjusted by moving the handle 60 inward or outward from the arm tubes 50a, aligning one of the holes 62 with each hole 55 and then positioning the handle 60 with respect to the arm tubes 50a by using headed screw members 57. The back support rod 58 is attached to two hollow seats 58a of the arm tubes 50a which are in alignment with the holes 55. The screw members 57 which position the handle 60 extend into the hollow seats 58a to position the back support rod 58. Two arm-rest members 52 are attached to the arm tubes 50a.
The seat assembly 70 has a back whose top is provided with a sleeve 72 to be attached to the back support rod 58. The sleeve 72 can be detached from the back support rod 58 by detaching the screw members 57. The seat assembly 70 further has bottom fastening straps 74 to connect the bottom portion of the seat assembly 70 to the lower bent portions of the arm tubes 50a. A safety belt 75 is attached to the seat assembly 70. An accommodating bag 73 is provided at the back of the seat assembly 70.
The canopy assembly 90 has a canopy frame 92 whose ends 93 are attached to the arm tubes 50a at the holes 56. The assembly 90 also has a canopy 95 which is superimposed on the canopy frame 92 and whose rear end 951 is sleeved on a tube 96. The tube 96 is attached to two rod portions 94 of the canopy frame 92. Fastening rings 954 are attached to the canopy 95 to hook up the projecting heads of the screw members 54, thereby holding firmly the canopy 95 on the canopy frame 92.
The stroller of the present invention can be folded easily as shown in FIGS. 4 and 5. First, the arm tubes 50a are detached from the tubes 10a by loosening the screws 16 and then pulling the tubes 10a forward, thereby also pulling the rear support rods 30 downward and forward. Afterward, the rear wheels 20 are detached from the rear transverse rod 18 by pulling the pull rings 221 of the lock pins 22 out from the rod 18. The stroller is thereby folded in a compact size that can be easily carried and stored. The user may carry the stroller in a small vehicle to a strolling place.
With the invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope of the invention. It is therefore intended the invention be limited only as indicated in the appended claims.
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A stroller has a base frame which includes a front fork end connected to a front wheel and a rear end connected to two rear wheels. An elongated U-shaped tube member has its lower ends detachably connected to two sides of the base frame. A pair of rear support rods are pivoted to both the base frame and the U-shaped tube member. The stroller can be folded when the U-shaped tube member is detached from the base frame. The rear wheels can be detached from the base frame for convenient storage.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation of U.S. Pat. No. 9,250,972 B2, filed Jun. 19, 2006 and patented on Sep. 22, 2015, the entirety of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to the field of server provisioning and more particularly to server provisioning to heterogeneous target platforms and/or heterogeneous tasks.
Description of the Related Art
The enterprise has evolved over the past two decades from the smallest of peer to peer networks running multi-user applications without coordination, to massive distributed computing systems involving dozens of servers and thousands of clients across a vast geographical expanse. In the earlier days of enterprise class computing, deploying multi-user applications often involved nothing more than installing an application in a centralized location and providing communicative access to the different users over a small, computer communications network. Evolved configurations involved client-server computing where the power of the client computers could be exploited to support the execution of the application logic and the application data could be served from a central location.
The demands of modern enterprise class computing require more than simplistic client-server arrangements and involve the distributed deployment of multiple applications and application components across multiple different servers in different local networks banded together over a wide area utilizing high speed broadband communicative links. Creating an enterprise environment for single installation can be treated as a laboratory experiment and trial-and-error tactics rule the day. Where the installation must be repeated with consistency across installations, however, a more coordinated approach must be followed. A coordinated approach particularly can be important where customers receive the installation or the application itself as a product or service. In this circumstance, customers cannot tolerate an imperfect installation or an installation that appears to be more of a laboratory experiment than a coordinated effort.
Generally speaking, within the enterprise class environment, the coordinated installation of an application across one or more server computing platforms in a repeatable fashion has come to be known as “server provisioning” borrowing a term from the field of telecommunications. Server provisioning literally implies the deployment of an application onto a host computing platform in a coordinated and repeatable fashion. In the simplified provisioning exercise, an operator installs and configures the various applications in the host computing platform according to a pre-defined installation plan ordinarily specified by an application manufacturer or a systems integrator.
In as much as only a single host computing platform and host operating systems are to be considered in the course of the simplified provisioning exercise, the process can be relatively straightforward. In the larger enterprise, however, the process can be quite complex. So complex has server provisioning become, several manufacturers have developed automated tools for managing the server provisioning process. In conventional server provisioning tools, a set of applications and applications can be configured in a master arrangement and the master arrangement can be replicated to a target platform. Unfortunately, conventional server provisioning tools rely heavily on the nature of the target platform and are hardwired to a specified platform. To that end, conventional server provisioning tools are ill-equipped to handle heterogeneous computing environments including multiple different target platform types.
BRIEF SUMMARY OF THE INVENTION
Embodiments of the present invention address deficiencies of the art in respect to server provisioning in a heterogeneous computing environment and provide a novel and non-obvious method, system and computer program product for secure and verified distributed orchestration and provisioning. In one embodiment of the invention, a server provisioning method can be provided. The server provisioning method can include establishing grouping criteria, grouping different target computing nodes into different groups of target computing nodes according to the established grouping criteria, server provisioning a root node in each of the different groups of target computing nodes, and relying upon the root node in each of the different groups to peer-to-peer server provision remaining nodes in each of the different groups.
Establishing grouping criteria can include establishing grouping criteria according to a type of target node, a type of server provisioning task, or both. In particular, grouping different target computing nodes into different groups of target computing nodes according to the established grouping criteria can include computing a detailed provisioning task value for each of the target computing nodes indicating a presence and an absence of different components required for server provisioning each of the target computing nodes, and grouping sets of the target computing nodes having similar detailed provisioning task values.
Utilizing the detailed provisioning task value, server provisioning a root node in each of the different groups of target computing nodes can include assembling a bundle for distribution to the root node for each of the different groups of target computing nodes, the bundle including in each instance a set of components required for server provisioning target nodes in a respective group of target nodes. Thereafter, the bundle can be forwarded to the root node.
Finally, relying upon the root node in each of the different groups to peer-to-peer server provision remaining nodes in each of the different groups can include specifying a threshold for available bandwidth and a maximum random delay time for use by peer-to-peer provisioning logic in the root node in determining when to server provision the remaining nodes, and providing a bundle to the root node for distribution to each of the remaining nodes at an interval computed from the threshold and maximum random delay.
In another embodiment of the invention, a server provisioning data processing system can be provided. The system can include an orchestration and provisioning server coupled to multiple target computing nodes over a computer communications network. Each of the target computing nodes can include peer-to-peer provisioning logic including program code enabled to server provision coupled nodes at a lower hierarchical level with a bundle received from a node at a higher hierarchical level. A certificate managing authority also can be coupled to the target computing nodes.
The system further can include orchestration and provisioning logic disposed in the orchestration and provisioning server. The logic can include program code enable to group different ones of the target computing nodes into different hierarchically arranged groups of the target computing nodes according to grouping criteria, and to server provisioning a root node in each of the different groups of target computing nodes. The grouping criteria can include only target computing node type, only provisioning task type, or both target computing node type and provisioning task type.
Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. The embodiments illustrated herein are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein:
FIG. 1 is a schematic illustration of a computing enterprise configured for orchestrated peer-to-peer server provisioning;
FIG. 2 is a flow chart illustrating a process for orchestrated peer-to-peer server provisioning; and,
FIG. 3 is a flow chart illustrating a peer-driven process of server provisioning in the computing enterprise of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention provide a method, system and computer program product for orchestrated peer-to-peer server provisioning. In accordance with an embodiment of the present invention, different target peers in a pool of server targets in a computing enterprise can be grouped according to server provisioning requirements in a peer hierarchy. The server provisioning requirements can relate to the set of components required to be deployed onto a particular target based upon the presence and the absence of specific components required for a complete deployment. In this regard, the set of required components can vary according to the type of peer targeted to receive the deployment, the type of deployment task, or both the type of peer and the type of deployment task.
Thereafter, different server provisioning bundles can be assembled for delivery to the peers in the different groups along with a specification of the server provisioning tasks to be performed in order to complete the deployment in the target group of peers. Notably, each peer in each different group can be enabled to receive the bundle and the instructions and to further deploy the bundle and the instructions to other coupled peers at lower levels in the hierarchy. In this way, a set of target peers directly receiving a server provisioning bundle can be substantially less than the set of target peers intended to receive the server provisioning bundle and the responsibility of server provisioning can be shared with the nodes in the target group of peers.
In illustration, FIG. 1 is a schematic illustration of a computing enterprise configured for orchestrated peer-to-peer server provisioning. The computing enterprise can include multiple, heterogeneous target computing nodes 160 communicatively coupled to one another over a computer communications network. Each of the target computing nodes 160 can include computing structure and a corresponding operating system in order to enable each of the target computing nodes 160 to host and manage the execution of computing logic.
An orchestration and provisioning server 110 can be coupled to the target computing nodes 160 . The orchestration and provisioning server 110 can include knowledge of the target computing nodes 160 such as the location of each of the nodes 160 in terms of network and sub-network, the operating system hosted within each of the nodes 160 , the service pack level for each operating system, the fix pack level for each operating system, and the software installed in each of the nodes 160 , at both the application and component level. The orchestration and provisioning server 110 further can include a policy that among other parameters, defines the maximum number of servers to be provisioned linearly. The maximum number can be computed according to a number of factors, for example, the processing power of the orchestration and provisioning server 110 as compared to others of the nodes 160 , the distribution mechanism for the server provisioning task, e.g. push or pull, and the number of nodes 160 in the environment.
The orchestration and provisioning server 110 can include orchestration and provisioning program logic 200 . The orchestration and provisioning logic 200 can include program code enabled to group different ones of the target computing nodes 160 according to provisioning task requirements to fulfill server provisioning for the target computing nodes 160 . Specifically, the target computing nodes 160 can be grouped according to the number and identity of components necessary to deploy onto the target computing nodes 160 , or the type of provisioning tasks necessary to deploy selected components for server provisioning onto the target computing nodes 160 , or both. In one aspect of the invention, the number of groups can be determined according to the policy defining a maximum number of nodes 160 to be provisioned linearly.
Importantly, the program code of the orchestration and provisioning logic 200 can be further enabled to compute a set of metrics for a detailed provisioning task (DPT) 170 . The DPT 170 can specify a minimal set of components for a provisioning task and can represent the presence and the absence of different required components in a particular one of the target computing nodes 160 . The different required components can vary according to the specific type of the provisioning task, or the type of type of the particular one of the target computing nodes 160 . As an example, a value of “0” can represent the absence of a required component, while the value of “1” can represent the presence of a required component. In this way, a single value can encode the set of required components that must be installed onto a specified one of the target computing nodes 160 in order to fulfill a provisioning task.
The program code of the orchestration and provisioning logic 200 yet further can be enabled to compare the DPT 170 for each of the target computing nodes 160 in order to group clusters of the target computing nodes 160 according to similar metrics. In particular, those of the target computing nodes 160 having the most similar set of metrics in a DPT 170 can be considered to require a similar set of components in order to complete a server provisioning task. Consequently, a collection of components necessary to meet the requirements of a server provisioning task for a group of the target computing nodes 160 can be assembled in a bundle 130 , such as an Open Services Gateway Initiative (OSGI) bundle, and provided to the group for provisioning onto the target computing nodes 160 in the group.
Notably, each of the target computing nodes 160 in the group can include peer to peer provisioning (P2PP) logic 150 . The P2PP logic 150 can include program code enabled to receive the bundle 130 and apply the bundle 130 to other coupled ones of the target computing nodes 160 in the group of target computing nodes 160 . In this way, the program code of the orchestration and provisioning logic 200 need only apply the bundle 130 to a root node in the group of target computing nodes 160 . The P2PP logic 150 of the root node in the group of target computing nodes 160 in turn can apply the bundle to other nodes in the group of target computing nodes 160 and so forth.
Finally, a certificate managing authority 120 can be communicatively coupled to the orchestration and provisioning server 110 and to each of the target computing nodes 160 . The certificate managing authority 120 can be configured to verify on request the source of the bundles 130 so as to ensure a secure environment for server provisioning.
In more particular illustration of the operation of the orchestration and provisioning logic 200 , FIG. 2 is a flow chart illustrating a process for orchestrated peer-to-peer server provisioning. Beginning in block 210 , a list of target nodes can be selected for server provisioning. In block 220 , criteria for grouping the target nodes can be selected. The criteria can include the similarity in the number and type of components to be installed as compared to those components already present in the nodes. The number and type of components can vary not only according to node type (e.g. type of host operating system), but also according to task type (e.g. type of application to be installed, or installation operation that can vary from an installation to an updating to an un-installation).
In block 230 , the target nodes can be grouped according to the selected criteria limited only by the number of groups suggested by the policy. In block 240 , a first group can be selected for consideration and in block 250 , a bundle can be computed for the group. The bundle can include a collection of components and supporting files required to complete server provisioning for the nodes in the group at both the root level and levels below the root level within the hierarchy of the group. Thereafter, in block 260 the bundle can be provided to the root node for the group. The root node in turn can install the requisite components in the bundle and can provide the bundle to nodes below the root node for server provisioning therein.
In decision block 270 , if additional groups of nodes remain to be considered, in block 280 , a next group of nodes can be selected for consideration and the process can repeat through block 250 . In particular, the process can repeat for each computed group wherein each computed group receives a bundle specifically arranged to account for the type of node, the type of provisioning task, or both. When the root nodes of the groups have received and applied the bundles, reports can be generated indicating the results of each of the server provisioning tasks for each of the nodes. The reports can filter back to the orchestration and provisioning server and ultimately can be stored in block 290
As the P2PP logic in the nodes within each group receive a bundle for distribution to other nodes at lower hierarchical levels, the program code of the P2PP logic can undertake measures to avoid network overloading in the course of peer-to-peer distributing the bundles. In particular, as shown in FIG. 3 , beginning in block 310 a node can receive a bundle for use in server provisioning. In block 320 , a random period of time can elapse subsequent to which in block 330 , the traffic on the network can be sensed to determine available network bandwidth. The random period of time can be specified by the provisioning server along with the receipt of the bundle.
In decision block 340 , if sufficient network bandwidth exists, in block 350 the bundle can be provisioned to the next set of nodes at a lower level in the nodal hierarchy within the set of grouped target computing nodes. Thereafter, in block 360 , a resulting report can be received from each of the nodes in the next set of nodes and reported back to a provisioning node at a higher hierarchical level in block 270 . In this way, each of the nodes at each level in the hierarchy can share in the burden of performing the provisioning task without requiring the provisioning server to provision each node in the hierarchy sequentially.
Embodiments of the invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, and the like. Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system.
For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD.
A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers. Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.
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Embodiments of the present invention address deficiencies of the art in respect to server provisioning in a heterogeneous computing environment and provide a method, system and computer program product for secure and verified distributed orchestration and provisioning. In one embodiment of the invention, a server provisioning method can be provided. The server provisioning method can include establishing grouping criteria, grouping different target computing nodes into different groups of target computing nodes according to the established grouping criteria, server provisioning a root node in each of the different groups of target computing nodes, and relying upon the root node in each of the different groups to peer-to-peer server provision remaining nodes in each of the different groups.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A “SEQUENCE LISTING”
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates to ejectors, and more particularly to a compressible gas ejector having an unexpanded motive gas exposed to a load gas, wherein the interface of the unexpanded motive gas and the load gas can be located in a suction chamber or a downstream diffuser.
[0006] 2. Description of Related Art
[0007] Steam jet ejectors are employed in the chemical process industries, refineries as well as power generation plants, stills, vacuum deaerator evaporators, crystallizers, steam vacuum refrigeration, flack coolers, condensers, vacuum pan dryers, dehydrators, vacuum impregnators, freeze dryers and vacuum filters. The ejector provides a vacuum that can be applied, depending upon the design of the ejector, from relatively small loads to significant loads. Ejectors can also be used to evacuate air and/or combustion products in aerodynamic and combustion processes.
[0008] Ejectors can also be used to provide the vacuum (pressure below atmospheric) for the production of natural fats and oils and derivative oleochemicals. In addition, degumming, bleaching, interestification, fractionation, winterization and deodorization are often supported by ejectors.
[0009] As seen in FIG. 1 , a prior art ejector includes a motive venturi, a suction chamber and a downstream diffuser. The motive venturi includes a converging section, a throat and a diverging section, wherein the suction chamber encompasses (and is thus fluidly exposed to) the open diverging end of the motive venturi. The suction chamber is fluidly exposed to a suction inlet and hence to a load gas and the diffuser. The diffuser is also a venturi and includes a converging section beginning in the suction chamber, a throat and a diverging section.
[0010] Generally, the ejector converts pressure energy, for example, a motive stream, into kinetic energy (velocity). Referring to FIG. 1 , prior art steam ejectors 1 obtain the desired by velocity by the adiabatic expansion of the motive steam through a convergent and divergent section of the motive venture 3 . As seen in FIG. 1 , the velocity of the motive steam continually increases as the motive steam passes along the divergent section of the motive venturi. The motive steam is typically expanded to the pressure of the load gas. The high velocity motive steam then passes into a suction chamber 5 . The resulting high velocity, motive steam is then retarded in the suction chambers while the load steam is accelerated in the suction chamber and forms a mixture.
[0011] The mixture passes through the converging section, the throat and the diverging section of a diffuser 7 , wherein the high velocity is converted back into pressure. Thus, the mixture can be vented to atmospheric pressure, or additional ejectors can be employed to sufficiently raise the pressure to atmospheric pressure.
[0012] In certain applications, it is advantageous for the ejector to remove a certain ratio of motive gas to load gas. Historically, in sub critical flows, the ejectors are only able to provide a motive mass flow to load mass flow ratio of approximately 2.0. However, certain applications can be provided with increased efficiency, if the ratio of motive mass flow to load mass flow is on the order of 1.5. Therefore, the need exists for a compressible gas ejector that can reduce the ratio of motive gas mass flow to load gas mass flow.
BRIEF SUMMARY OF THE INVENTION
[0013] The present ejector provides a compressible gas ejector with an improved motive gas mass flow to load mass gas flow ratio.
[0014] In one configuration, the present compressible gas ejector provides for the direct contact of unexpanded motive gas with the load gas. Depending upon the particular construction, the interface between the unexpanded motive gas and the load gas can be located in the suction chamber or a converging section of the diffuser.
[0015] Contrary to prior teachings which suggest detrimental instability upon exposing unexpanded motive flow in the suction chamber, the present configuration provides stable mass flow rates, with the unexpanded motive gas directly mixing with the load gas.
[0016] In a further configuration, the compressible gas ejector, includes a converging motive funnel, the motive funnel having a converging section being substantially free of a downstream diverging section; a suction chamber fluidly connected to the motive funnel; and a diffuser downstream of the suction chamber, the diffuser including a converging section and a downstream diverging section. In one configuration, a downstream end of the motive funnel is disposed within the converging section of the diffuser.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0017] FIG. 1 is a cross-sectional view of a prior art steam ejector.
[0018] FIG. 2 is a cross-sectional view of the present ejector.
[0019] FIG. 3 is a cross sectional view of a regulator for controlling flow through the motive funnel.
[0020] FIG. 4 is a cross sectional view of an alternative regulator.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring to FIG. 2 , the present compressible gas ejector 10 is shown. For purposes of description, a motive gas 12 is introduced into the ejector to draw a load gas 14 into the ejector so as to form a mixture 16 , wherein the mixture exits the ejector 10 at a downstream location. The term “motive gas” 12 is intended to encompass any of a variety of motive flows including steam, vapor or other compressible flows, as well as mixtures thereof. The term “load gas” 14 is intended to encompass any of a variety of load gases such as, but not limited to process by-products, combustion products or other compressible flows, or mixtures thereof.
[0022] The ejector 10 includes a suction chamber, an upstream motive funnel 20 and a downstream diffuser 60 , wherein the motive gas 12 passes through the motive funnel 20 and mixes with the load gas 14 from the suction chamber and is discharged through the diffuser.
[0023] As seen in FIG. 2 , the upstream motive funnel 20 and the downstream diffuser 60 extend along a longitudinal axis and are generally coaxial. As the suction chamber 40 encompasses a portion of the motive funnel 20 and interfaces with the diffuser 60 , the suction chamber also includes a dimension extending along the longitudinal axis.
[0024] Therefore, for definitional purposes, a component or portion of the motive funnel 20 or the diffuser 60 can be described in terms of a “length” which is a dimension extending along the longitudinal axis. A width of a component is that dimension transverse to the longitudinal axis.
[0025] The suction chamber 40 includes a suction inlet 42 fluidly connected to the load gas 14 , which is to be drawn into the ejector 10 and passed through the diffuser 60 .
[0026] The converging motive funnel 20 is fluidly connected to a source of the motive gas such as steam from a turbine discharge. The motive funnel 20 includes an entrance port 22 and a downstream exit port 24 , wherein the entrance port is larger than the exit port. A converging section 26 extends from the entrance port 22 , and in selected configurations, terminates at the exit port 24 . Thus, in contrast to prior ejectors, the present converging motive funnel 20 does not include a diverging portion, and thus presents unexpanded motive gas 12 to the load gas 14 .
[0027] In other configurations, the motive funnel 20 can include a throat 30 downstream of the converging section 26 , wherein the throat defines a substantially constant cross-section along the longitudinal axis and terminates at the exit port 24 of the motive funnel. Typically, the throat 30 of the motive funnel 20 will have a length that is less than the length of the converging section 26 of the motive funnel. In this construction, a downstream end of the throat 30 defines the exit port 24 , and hence the downstream end of the motive funnel 20 .
[0028] The motive funnel 20 is selected to provide substantially unexpanded motive gas 1 2 at the exit port 24 . Thus, the particular convergence within the motive funnel 20 is at least partially determined by the intended operating parameters.
[0029] In one satisfactory configuration, the diameter of the entrance port 22 can be between approximately 1.85 to 2.25 times the diameter of the exit port 24 . The inlet diameter of the entrance port 22 of the converging section of the motive funnel 20 can be greater than the length of the motive funnel. Typical angles for the converging section of the motive funnel 20 are between approximately 35° and approximately 80°, with at least one satisfactory angle of approximately 60°.
[0030] It is understood the motive funnel 20 , or the downstream end of the throat 30 , can include a de minimis diverging taper 32 , such as along a wall thickness of the funnel. That is, the exit port 24 can include a diverging flare on the order of less than 5% of the area of the exit port. However, such diverging taper 32 does not allow a material expansion of the motive gas.
[0031] In selected configurations as seen in FIG. 3 , the motive funnel 20 includes a regulator 34 to effectively reduce the cross sectional area of the exit port 24 without changing pressure of the motive gas. The regulator 34 thus provides for the selective reduction in the amount of motive gas 12 passing through the motive funnel 20 . In one configuration, the regulator 34 moves relative to the exit port 24 to effectively change the cross sectional area of the exit port. The regulator 34 is selected to substantially maintain the pressure drop along the ejector 10 , thereby maintaining efficiency of the ejector.
[0032] In one configuration of the regulator 34 , the regulator includes a generally tapered spike 36 which can be moved along the longitudinal axis towards and away from the exit port 24 of the motive funnel 20 . Referring to FIG. 3 , the spike 36 can be curvilinear such as parabolic. In one configuration of the parabolic spike 36 , the curvature is defined by the relation Y=√ {square root over (0.008)}(x) . In an alternative configuration, the spike 36 defines a conical cross-section, as seen in FIG. 4 .
[0033] The diffuser 60 includes a converging section 62 , a throat 64 and a diverging section 68 . The converging section 62 includes an inlet 61 and a downstream outlet 63 coincident with the throat 64 . In contrast to prior ejectors, the present diffuser converging section 62 has a length that is less than an inlet diameter of the converging section. In certain constructions, the inlet diameter of the converging section 62 is on the order of twice the length of the converging section 62 . Functionally, the diameter of the inlet 61 and the length of the converging section 62 are selected to substantially maintain a steady state operation of the ejector 10 at the intended flow rates.
[0034] It is further contemplated, that in selected configurations, the diameter of the inlet 61 of the converging section 62 is at least 1.5, and can be greater than twice the diameter of the outlet 63 (the throat 64 of the diffuser 60 ). As the inlet diameter of the converging section 62 increases, the interface area between the load gas 14 and the unexpanded motive gas 12 increases, with the downstream end of the motive funnel 20 remaining within the length of the converging section of the diffuser.
[0035] In certain constructions, the diverging section 66 of the diffuser 60 is longer than the converging section 62 of the diffuser, wherein the diverging section can be at least twice the length of the converging section.
[0036] As seen in FIG. 2 , the exit port 24 of the motive funnel 20 is disposed within the inlet of the converging section 62 of the diffuser 60 . That is, as the converging section 62 of the diffuser 60 extends along the longitudinal dimension, the exit port 24 is located within the same length of the longitudinal dimension. The amount of penetration of the motive funnel 20 into the converging section 62 of the diffuser 60 can range from approximately 1% of the length of the converging section to approximately 50% of the length of the converging section.
[0037] Therefore, a flow path of the motive gas 12 passes through the motive funnel 20 and the exit port 24 , to then enter the converging section 62 of the diffuser 60 . Load gas 14 is drawn in through the suction inlet 42 and mixes with the motive gas 12 in the converging section 62 of the diffuser 60 to form the entrained mixture 16 , wherein the entrained mixture passes through the diffuser 60 and increases pressure.
[0038] It has been found advantageous to employ the present ejector 10 in a sub critical flow regime. That is, the pressure of the motive gas 12 is less than twice the pressure of the load gas 14 .
[0039] Further, it has been found that the motive funnel 20 can discharge the motive gas 12 into the suction chamber 40 , or the converging section 62 of the diffuser 60 at a pressure that is lower than the load gas 14 .
[0040] While the invention has been described in connection with a presently preferred embodiment thereof, those skilled in the art will recognize that many modifications and changes may be made therein without departing from the true spirit and scope of the invention, which accordingly is intended to be defined solely by the appended claims.
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A compressible gas ejector is configured to present unexpanded motive gas to a load gas, wherein the interface of the unexpanded motive gas and the load gas can be located in a suction chamber or within a downstream diffuser. The ejector includes a motive funnel for increasing the velocity of a relatively high pressure motive gas, the motive funnel substantially precluding adiabatic expansion of the motive gas.
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This application claims benefits of 60/238 205, filed Oct. 5, 2000.
BACKGROUND OF THE INVENTION
It is highly desirable for tires to exhibit good traction characteristics on both dry and wet surfaces. However, it has traditionally been very difficult to improve the traction characteristics of a tire without compromising its rolling resistance and tread wear. Low rolling resistance is important because good fuel economy is virtually always an important consideration. Good tread wear is also an important consideration because it is generally the most important factor that determines the life of the tire.
The traction, tread wear, and rolling resistance of a tire is dependent to a large extent on the dynamic viscoelastic properties of the elastomers utilized in making the tire tread. In order to reduce the rolling resistance of a tire, rubbers having a high rebound have traditionally been utilized in making the tire's tread. On the other hand, in order to increase the wet skid resistance of a tire, rubbers that undergo a large energy loss have generally been utilized in the tire's tread. In order to balance these two viscoelastically inconsistent properties, mixtures of various types of synthetic and natural rubber are normally utilized in tire treads. For instance various mixtures of styrene-butadiene rubber and polybutadiene rubber are commonly used as a rubber material for automobile tire treads. However, such blends are not totally satisfactory for all purposes.
The inclusion of styrene-butadiene rubber (SBR) in tire tread formulations can significantly improve the traction characteristics of tires made therewith. However, styrene is a relatively expensive monomer and the inclusion of SBR is tire tread formulations leads to increased costs.
Carbon black is generally included in rubber compositions which are employed in making tires and most other rubber articles. It is desirable to attain the best possible dispersion of the carbon black throughout the rubber to attain optimized properties. It is also highly desirable to improve the interaction between the carbon black and the rubber. By improving the affinity of the rubber compound to the carbon black, physical properties can be improved. Silica can also be included in tire tread formulations to improve rolling resistance.
U.S. Pat. No. 4,843,120 discloses that tires having improved performance characteristics can be prepared by utilizing rubbery polymers having multiple glass transition temperatures as the tread rubber. These rubbery polymers having multiple glass transition temperatures exhibit a first glass transition temperature which is within the range of about −110° C. to −20° C. and exhibit a second glass transition temperature which is within the range of about −50° C. to 0° C. According to U.S. Pat. No. 4,843,120, these polymers are made by polymerizing at least one conjugated diolefin monomer in a first reaction zone at a temperature and under conditions sufficient to produce a first polymeric segment having a glass transition temperature which is between −110° C. and −20° C. and subsequently continuing said polymerization in a second reaction zone at a temperature and under conditions sufficient to produce a second polymeric segment having a glass transition temperature which is between −20° C. and 20° C. Such polymerizations are normally catalyzed with an organolithium catalyst and are normally carried out in an inert organic solvent.
U.S. Pat. No. 5,137,998 discloses a process for preparing a rubbery terpolymer of styrene, isoprene, and butadiene having multiple glass transition temperatures and having an excellent combination of properties for use in making tire treads which comprises: terpolymerizing styrene, isoprene and 1,3-butadiene in an organic solvent at a temperature of no more than about 40° C. in the presence of (a) at least one member selected from the group consisting of tripiperidino phosphine oxide and alkali metal alkoxides and (b) an organolithium compound.
U. S. Pat. No. 5,047,483 discloses a pneumatic tire having an outer circumferential tread where said tread is a sulfur cured rubber composition comprised of, based on 100 parts by weight rubber (phr), (A) about 10 to about 90 parts by weight of a styrene, isoprene, butadiene terpolymer rubber (SIBR), and (B) about 70 to about 30 weight percent of at least one of cis 1,4-polyisoprene rubber and cis 1,4-polybutadiene rubber wherein said SIBR rubber is comprised of (1) about 10 to about 35 weight percent bound styrene, (2) about 30 to about 50 weight percent bound isoprene and (3) about 30 to about 40 weight percent bound butadiene and is characterized by having a single glass transition temperature (Tg) which is in the range of about −10° C. to about −40° C. and, further the said bound butadiene structure contains about 30 to about 40 percent 1,2-vinyl units, the said bound isoprene structure contains about 10 to about 30 percent 3,4-units, and the sum of the percent 1,2-vinyl units of the bound butadiene and the percent 3,4-units of the bound isoprene is in the range of about 40 to about 70 percent.
U.S. Pat. No. 5,272,220 discloses a styrene-isoprene-butadiene rubber which is particularly valuable for use in making truck tire treads which exhibit improved rolling resistance and tread wear characteristics, said rubber being comprised of repeat units which are derived from about 5 weight percent to about 20 weight percent styrene, from about 7 weight percent to about 35 weight percent isoprene, and from about 55 weight percent to about 88 weight percent 1,3-butadiene, wherein the repeat units derived from styrene, isoprene and 1,3-butadiene are in essentially random order, wherein from about 25% to about 40% of the repeat units derived from the 1,3-butadiene are of the cis-microstructure, wherein from about 40% to about 60% of the repeat units derived from the 1,3-butadiene are of the trans-microstructure, wherein from about 5% to about 25% of the repeat units derived from the 1,3-butadiene are of the vinyl-microstructure, wherein from about 75% to about 90% of the repeat units derived from the isoprene are of the 1,4-microstructure, wherein from about 10% to about 25% of the repeat units derived from the isoprene are of the 3,4-microstructure, wherein the rubber has a glass transition temperature which is within the range of about −90° C. to about −70° C., wherein the rubber has a number average molecular weight which is within the range of about 150,000 to about 400,000, wherein the rubber has a weight average molecular weight of about 300,000 to about 800,000, and wherein the rubber has an inhomogeneity which is within the range of about 0.5 to about 1.5.
U.S. Pat. No. 5,239,009 reveals a process for preparing a rubbery polymer which comprises: (a) polymerizing a conjugated diene monomer with a lithium initiator in the substantial absence of polar modifiers at a temperature which is within the range of about 5° C. to about 100° C. to produce a living polydiene segment having a number average molecular weight which is within the range of about 25,000 to about 350,000; and (b) utilizing the living polydiene segment to initiate the terpolymerization of 1,3-butadiene, isoprene, and styrene, wherein the terpolymerization is conducted in the presence of at least one polar modifier at a temperature which is within the range of about 5° C. to about 70° C. to produce a final segment which is comprised of repeat units which are derived from 1,3-butadiene, isoprene, and styrene, wherein the final segment has a number average molecular weight which is within the range of about 25,000 to about 350,000. The rubbery polymer made by this process is reported to be useful for improving the wet skid resistance and traction characteristics of tires without sacrificing tread wear or rolling resistance.
U.S. Pat. No. 5,061,765 discloses isoprene-butadiene copolymers having high vinyl contents which can reportedly be employed in building tires which have improved traction, rolling resistance, and abrasion resistance. These high vinyl isoprene-butadiene rubbers are synthesized by copolymerizing 1,3-butadiene monomer and isoprene monomer in an organic solvent at a temperature which is within the range of about −10° C. to about 100° C. in the presence of a catalyst system which is comprised of (a) an organoiron compound, (b) an organoaluminum compound, (c) a chelating aromatic amine, and (d) a protonic compound; wherein the molar ratio of the chelating amine to the organoiron compound is within the range of about 0.1:1 to about 1:1, wherein the molar ratio of the organoaluminum compound to the organoiron compound is within the range of about 5:1 to about 200:1, and herein the molar ratio of the protonic compound to the organoaluminum compound is within the range of about 0.001:1 to about 0.2:1.
U.S. Pat. No. 5,405,927 discloses an isoprene-butadiene rubber which is particularly valuable for use in making truck tire treads, said rubber being comprised of repeat units which are derived from about 20 weight percent to about 50 weight percent isoprene and from about 50 weight percent to about 80 weight percent 1,3-butadiene, wherein the repeat units derived from isoprene and 1,3-butadiene are in essentially random order, wherein from about 3% to about 10% of the repeat units in said rubber are 1,2-polybutadiene units, wherein from about 50% to about 70% of the repeat units in said rubber are 1,4-polybutadiene units, wherein from about 1% to about 4% of the repeat units in said rubber are 3,4-polyisoprene units, wherein from about 25% to about 40% of the repeat units in the polymer are 1,4-polyisoprene units, wherein the rubber has a glass transition temperature which is within the range of about −90° C. to about −75° C., and wherein the rubber has a Mooney viscosity which is within the range of about 55 to about 140.
U.S. Pat. No. 5,654,384 discloses a process for preparing high vinyl polybutadiene rubber which comprises polymerizing 1,3-butadiene monomer with a lithium initiator at a temperature which is within the range of about 5° C. to about 100° C. in the presence of a sodium alkoxide and a polar modifier, wherein the molar ratio of the sodium alkoxide to the polar modifier is within the range of about 0.1:1 to about 10:1; and wherein the molar ratio of the sodium alkoxide to the lithium initiator is within the range of about 0.05:1 to about 10:1. By utilizing a combination of sodium alkoxide and a conventional polar modifier, such as an amine or an ether, the rate of polymerization initiated with organolithium compounds can be greatly increased with the glass transition temperature of the polymer produced also being substantially increased. The rubbers synthesized using such catalyst systems also exhibit excellent traction properties when compounded into tire tread formulations. This is attributable to the unique macrostructure (random branching) of the rubbers made with such catalyst systems.
U.S. Pat. Nos. 5,620,939, 5,627,237, and 5,677,402 also disclose the use of sodium salts of saturated aliphatic alcohols as modifiers for lithium initiated solution polymerizations. Sodium t-amylate is a preferred sodium alkoxide by virtue of its exceptional solubility in non-polar aliphatic hydrocarbon solvents, such as hexane, which are employed as the medium for such solution polymerizations. However, using sodium t-amylate as the polymerization modifier in commercial operations where recycle is required can lead to certain problems. These problems arise due to the fact that sodium t-amylate reacts with water to form t-amyl alcohol during steam stripping in the polymer finishing step. Since t-amyl alcohol forms an azeotrope with hexane, it co-distills with hexane and thus contaminates the feed stream
Tire rubbers which are prepared by anionic polymerization are frequently coupled with a suitable coupling agent, such as a tin halide, to improve desired properties. Tin-coupled polymers are known to improve treadwear and to reduce rolling resistance when used in tire tread rubbers. Such tin-coupled rubbery polymers are typically made by coupling the rubbery polymer with a tin coupling agent at or near the end of the polymerization used in synthesizing the rubbery polymer. In the coupling process, live polymer chain ends react with the tin coupling agent thereby coupling the polymer. For instance, up to four live chain ends can react with tin tetrahalides, such as tin tetrachloride, thereby coupling the polymer chains together.
The coupling efficiency of the tin coupling agent is dependant on many factors, such as the quantity of live chain ends available for coupling and the quantity and type of polar modifier, if any, employed in the polymerization. For instance, tin coupling agents are generally not as effective in the presence of polar modifiers. However, polar modifiers such as tetramethylethylenediamine, are frequently used to increase the glass transition temperature of the rubber for improved properties, such as improved traction characteristics in tire tread compounds. Coupling reactions that are carried out in the presence of polar modifiers typically have a coupling efficiency of about 50-60% in batch processes. Lower coupling efficiencies are typically attained in continuous processes.
U.S. Pat. No. 6,489,403 discloses that coupling efficiency can be significantly improved by conducting the coupling reactions in the presence of a lithium salt of a saturated aliphatic alcohol, such as lithium t-amylate. In the alternative coupling efficiency can also be improved by conducting the coupling reaction in the presence of a lithium halide, or a lithium phenoxide. U.S. Pat. No. 6,489,403 specifically discloses a process for coupling a living rubbery polymer that comprises reacting the living rubbery polymer with coupling agent selected from the group consisting of tin halides and silicon halides in the presence of a lithium salt of a saturated aliphatic alcohol. The lithium salt of the saturated aliphatic alcohol can be added immediately prior to the coupling reaction or it can be present throughout the polymerization and coupling process.
Each tin tetrahalide molecule or silicon tetrahalide molecule is capable of reacting with up to four live polymer chain ends. However, since perfect stoichiometry is difficult to attain, some of the tin halide molecules often react with less than four live polymer chain ends. The classical problem is that if more than a stoichiometric amount of the tin halide coupling agent is employed, then there will be an insufficient quantity of live polymer chain ends to totally react with the tin halide molecules on a four-to-one basis. On the other hand, if less than a stoichiometric amount of the tin halide coupling agent is added, then there will be an excess of live polymer chain ends and some of the live chain ends will not be coupled. It is accordingly important for the stoichiometry to be exact and for all to the living polymer chain-ends to react with the coupling agent.
Conventional tin coupling results in the formation of a coupled polymer that is essentially symmetrical. In other words, all of the polymer arms on the coupled polymer are of essentially the same chain length. All of the polymer arms in such conventional tin-coupled polymers are accordingly of essentially the same molecular weight. This results in such conventional tin-coupled polymers having a low polydispersity. For instance, conventional tin-coupled polymers normally having a ratio of weight average molecular weight to number average molecular weight which is within the range of about 1.01 to about 1.1
U.S. Pat. No. 5,486,574 discloses dissimilar arm asymmetric radical or star block copolymers for adhesives and sealants. U.S. Pat. No. 5,096,973 discloses ABC block copolymers based on butadiene, isoprene and styrene and further discloses the possibility of branching these block copolymers with tetrahalides of silicon, germanium, tin or lead.
U.S. Pat. No. 6,043,321 discloses an asymmetrical tin-coupled rubbery polymer which is particularly valuable for use in manufacturing tire tread compounds, said asymmetrical tin-coupled rubbery polymer being comprised of a tin atom having at least three polydiene arms covalently bonded thereto, wherein at least one of said polydiene arms has a number average molecular weight of less than about 40,000, wherein at least one of said polydiene arms has a number average molecular weight of at least about 80,000, and wherein the ratio of the weight average molecular weight to the number average molecular weight of the asymmetrical tin-coupled rubbery polymer is within the range of about 2 to about 2.5.
SUMMARY OF THE INVENTION
The present invention relates to an anionic polymerization technique for synthesizing functionalized rubbery polymers containing polysiloxane that have excellent characteristics for utilization in (a) tire tread compounds that are highly loaded with silica, (b) shiny tire side-wall compounds, and (c) tire building bladders having improved mold release characteristics. The rubbery polymers of this invention can optionally be coupled with tin halides or silicon halides to further improve the characteristics of the rubber for use in tire tread compounds. The rubbers of this invention can be easily hydrolyzed which leads to good interaction with silica.
The present invention more specifically discloses a process for synthesizing a rubbery polymer that comprises (1) polymerizing at least one conjugated diolefin monomer to produce a living rubbery polymer, wherein said polymerization is an anionic polymerization that is initiated with an alkylsilyloxy protected functional lithium initiator having a structural formula selected from the group consisting:
wherein X represents a group IVa element selected from the group consisting of carbon, silicon, germanium, and tin, wherein Y represents phosphorous or nitrogen, wherein R represents alkyl groups that can be the same or different, wherein the alkyl groups contain from 1 to about 8 carbon atoms, and wherein A represents an alkylene group containing from 1 to about 8 carbon atoms; (2) adding a hexaalkylcyclotrisiloxane monomer to the living rubbery polymer; (3) allowing the hexaalkylcyclotrisiloxane monomer to polymerize to produce a living polysiloxane containing rubber; and (4) reacting the living polysiloxane containing rubber with a coupling agent selected from the group consisting of tin halides and silicon halides to produce a coupled polysiloxane containing rubber.
The present invention further discloses a process for synthesizing a functionalized rubbery polymer containing polysiloxane that comprises (1) polymerizing at least one conjugated diolefin monomer to produce a living rubbery polymer, wherein said polymerization is an anionic polymerization that is initiated with an alkylsilyloxy protected functional lithium initiator having a structural formula selected from the group consisting:
wherein X represents a group IVa element selected from the group consisting of carbon, silicon, germanium, and tin, wherein Y represents phosphorous or nitrogen, wherein R represents alkyl groups that can be the same or different, wherein the alkyl groups contain from 1 to about 8 carbon atoms, and wherein A represents an alkylene group containing from 1 to about 8 carbon atoms; (2) adding a hexaalkylcyclotrisiloxane monomer to the living rubbery polymer; (3) allowing the hexaalkylcyclotrisiloxane monomer to polymerize to produce a living polysiloxane containing rubber; and (4) shortstopping the polymerization to produce the functionalized rubbery polymer containing polysiloxane.
The hexaalkylcyclotrisiloxane monomers that can be used are of the structural formula:
wherein R represents an alkyl group containing from 1 to about 8 carbon atoms. R will typically represent an alkyl group containing from 1 to about 4 carbon atoms. Some representative examples of hexaalkylcyclotrisiloxane monomers that can be used include hexamethylcyclotrisiloxane, hexaethylcyclotrisiloxane, and hexapropylcyclotrisiloxane. It is normally preferred to use hexamethylcyclotrisiloxane. The polymerizations of this invention can optionally be conducted in the presence of a polar modifier.
The present invention further discloses a functionalized rubbery polymer wherein said functionalized rubbery polymer is comprised of a polymer chain having the structural formula:
wherein X represents a group IVa element selected from the group consisting of carbon, silicon, germanium, and tin, wherein n represents an integer from 1 to 10, wherein m represents an integer from about 1000 to about 10,000, wherein p represents an integer from about 2 to about 50, wherein R and R′ represents alkyl groups that can be the same or different, and wherein the alkyl groups contain from 1 to about 8 carbon atoms.
DETAILED DESCRIPTION OF THE INVENTION
The rubbery polymers of this invention will typically be synthesized by a solution polymerization technique that utilizes as the initiator an alkylsilyloxy protected functional lithium initiator of the structural formula: (a):
wherein X represents a group IVa element selected from the group consisting of carbon, germanium, silicon, and tin, wherein R represents alkyl groups that can be the same or different, wherein the alkyl groups contain from 1 to about 8 carbon atoms, and wherein A represents an alkylene group containing from 1 to about 8 carbon atoms; or (b):
wherein X represents a group IVa element selected from the group consisting of carbon, germanium, silicon, and tin, wherein Y represents phosphorous or nitrogen, wherein R represents alkyl groups that can be the same or different, wherein the alkyl groups contain from 1 to about 8 carbon atoms, and wherein A represents an alkylene group containing from 1 to about 8 carbon atoms. The alkylene group (A) can be straight chained or branched. For instance, A can represent a straight chained alkylene group of the structural formula —(CH 2 ) n — or it can represent a branched alkylene group, such as:
wherein R represents alkyl groups that can be the same or different, and wherein the alkyl groups contain from 1 to about 8 carbon atoms. R will typically represent an alkyl group containing from 1 to about 4 carbon atoms. It is preferred for R to represent methyl groups.
The alkylsilyloxy protected functional lithium initiator can be of the structural formula:
wherein X represents a group IVa element selected from the group consisting of carbon, silicon, germanium, and tin, wherein n represents an integer from 1 to 10, wherein R represents alkyl groups that can be the same or different, and wherein the alkyl groups contain from 1 to about 8 carbon atoms, or an alkylsilyloxy protected functional lithium compound of the structural formula:
wherein X represents a group IVa element selected from the group consisting of carbon, silicon, germanium, and tin, wherein Y represents phosphorous or nitrogen, wherein n represents an integer from 1 to 10, wherein R represents alkyl groups that can be the same or different, and wherein the alkyl groups contain from 1 to about 8 carbon atoms. These rubbery polymers will accordingly normally contain a “living” lithium chain end.
It is normally preferred for the alkylsilyloxy protected functional lithium initiator to be of the structural formula:
wherein R represents alkyl groups that can be the same or different, wherein the alkyl groups contain from 1 to about 8 carbon atoms, and wherein A represents an alkylene group containing from 1 to about 8 carbon atoms. A highly preferred initiator is 3-(t-butyldimethylsilyloxy)-1-propyllithium which is commercially available from FMC Corporation.
The polymerizations employed in synthesizing the living rubbery polymers will normally be carried out in a hydrocarbon solvent. Such hydrocarbon solvents are comprised of one or more aromatic, paraffinic or cycloparaffinic compounds. These solvents will normally contain from about 4 to about 10 carbon atoms per molecule and will be liquid under the conditions of the polymerization. Some representative examples of suitable organic solvents include pentane, isooctane, cyclohexane, methylcyclohexane, isohexane, n-heptane, n-octane, n-hexane, benzene, toluene, xylene, ethylbenzene, diethylbenzene, isobutylbenzene, petroleum ether, kerosene, petroleum spirits, petroleum naphtha, and the like, alone or in admixture.
In the solution polymerization, there will normally be from 5 to 30 weight percent monomers in the polymerization medium. Such polymerization media are, of course, comprised of the organic solvent and monomers. In most cases, it will be preferred for the polymerization medium to contain from 10 to 25 weight percent monomers. It is generally more preferred for the polymerization medium to contain 15 to 20 weight percent monomers.
The rubbery polymers that are coupled in accordance with this invention can be made by the homopolymerization of a conjugated diolefin monomer or by the random copolymerization of a conjugated diolefin monomer with a vinyl aromatic monomer. It is, of course, also possible to make living rubbery polymers that can be coupled by polymerizing a mixture of conjugated diolefin monomers with one or more ethylenically unsaturated monomers, such as vinyl aromatic monomers. The conjugated diolefin monomers which can be utilized in the synthesis of rubbery polymers which can be coupled in accordance with this invention generally contain from 4 to 12 carbon atoms. Those containing from 4 to 8 carbon atoms are generally preferred for commercial purposes. For similar reasons, 1,3-butadiene and isoprene are the most commonly utilized conjugated diolefin monomers. Some additional conjugated diolefin monomers that can be utilized include 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, 2-phenyl-1,3-butadiene, and the like, alone or in admixture.
Some representative examples of ethylenically unsaturated monomers that can potentially be synthesized into rubbery polymers which can be coupled in accordance with this invention include alkyl acrylates, such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate and the like; vinylidene monomers having one or more terminal CH 2 ═CH— groups; vinyl aromatics such as styrene, α-methylstyrene, bromostyrene, chlorostyrene, fluorostyrene and the like; α-olefins such as ethylene, propylene, 1-butene and the like, vinyl halides, such as vinylbromide, chloroethane (vinylchloride), vinylfluoride, vinyliodide, 1,2-dibromoethene, 1,1-dichloroethene (vinylidene chloride), 1,2-dichloroethene and the like; vinyl esters, such as vinyl acetate; α,β-olefinically unsaturated nitrites, such as acrylonitrile and methacrylonitrile; α,β-olefinically unsaturated amides, such as acrylamide, N-methyl acrylamide, N,N-dimethylacrylamide, methacrylamide and the like.
Rubbery polymers which are copolymers of one or more diene monomers with one or more other ethylenically unsaturated monomers will normally contain from about 50 weight percent to about 99 weight percent conjugated diolefin monomers and from about 1 weight percent to about 50 weight percent of the other ethylenically unsaturated monomers in addition to the conjugated diolefin monomers. For example, copolymers of conjugated diolefin monomers with vinylaromatic monomers, such as styrene-butadiene rubbers which contain from 50 to 95 weight percent conjugated diolefin monomers and from 5 to 50 weight percent vinylaromatic monomers, are useful in many applications.
Vinyl aromatic monomers are probably the most important group of ethylenically unsaturated monomers which are commonly incorporated into polydienes. Such vinyl aromatic monomers are, of course, selected so as to be copolymerizable with the conjugated diolefin monomers being utilized. Generally, any vinyl aromatic monomer which is known to polymerize with organolithium initiators can be used. Such vinyl aromatic monomers typically contain from 8 to 20 carbon atoms. Usually, the vinyl aromatic monomer will contain from 8 to 14 carbon atoms. The most widely used vinyl aromatic monomer is styrene. Some examples of vinyl aromatic monomers that can be utilized include styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, α-methylstyrene, 4-phenylstyrene, 3-methylstyrene and the like. In cases where the living rubbery polymer is comprised of repeat units that are derived from two or more monomers, the repeat units which are derived from the different monomers will normally be distributed in an essentially random manner However, the polysiloxane segment will be in a block at the end of the rubbery polymer segment.
The polymerizations employed in making the rubbery polymer are typically initiated by adding an organolithium initiator to an organic polymerization medium that contains the monomers. Such polymerizations are typically carried out utilizing continuous polymerization techniques. In such continuous polymerizations, monomers and initiator are continuously added to the organic polymerization medium with the rubbery polymer synthesized being continuously withdrawn. Such continuous polymerizations are typically conducted in a multiple reactor system.
The amount of organolithium initiator utilized will vary with the monomers being polymerized and with the molecular weight that is desired for the polymer being synthesized. However, as a general rule, from 0.01 to 1 phm (parts per 100 parts by weight of monomer) of an organolithium initiator will be utilized. In most cases, from 0.01 to 0.1 phm of an organolithium initiator will be utilized with it being preferred to utilize 0.025 to 0.07 phm of the organolithium initiator.
The polymerization temperature utilized can vary over a broad range of from about −20° C. to about 180° C. In most cases, a polymerization temperature within the range of about 30° C. to about 125° C. will be utilized. It is typically preferred for the polymerization temperature to be within the range of about 45° C. to about 100° C. It is typically most preferred for the polymerization temperature to be within the range of about 60° C. to about 85° C. The pressure used will normally be sufficient to maintain a substantially liquid phase under the conditions of the polymerization reaction.
The polymerization is conducted for a length of time sufficient to permit substantially complete polymerization of monomers. In other words, the polymerization is normally carried out until high conversions are attained. Then a hexaalkylcyclotrisiloxane monomer is added to the living rubbery polymer. The hexaalkylcyclotrisiloxane monomers that can be used are of the structural formula:
wherein R represents an alkyl group containing from 1 to about 8 carbon atoms. R will typically represent an alkyl group containing from 1 to about 4 carbon atoms. Some representative examples of hexaalkylcyclotrisiloxane monomers that can be used include hexamethylcyclotrisiloxane, hexaethylcyclotrisiloxane, and hexapropylcyclotrisiloxane. It is normally preferred to use hexamethylcyclotrisiloxane. The rubbery polymer will typically contain from about 0.1 weight percent to about 25 weight percent of the hexaalkylcyclotrisiloxane monomer, based on total bound monomers. The rubbery polymer will more typically contain from about 0.5 weight percent to about 5 weight percent of the hexaalkylcyclotrisiloxane monomer. The rubbery polymer will preferably contain from about 1 weight percent to about 3 weight percent of the hexaalkylcyclotrisiloxane monomer. The polymeric segment derived from the hexaalkylcyclotrisiloxane monomer will, of course, be in a block at the end of the polymer chain.
After the hexaalkylcyclotrisiloxane monomer has been exhausted the polymerization is terminated by the addition of a shortstop, such as an alcohol, or by the addition of a coupling agent, such as a tin halide and/or silicon halide. The tin halide and/or the silicon halide are continuous added in cases where asymmetrical coupling is desired. This continuous addition of tin coupling agent and/or the silicon coupling agent is normally done in a reaction zone separate from the zone where the bulk of the polymerization is occurring. In other words, the coupling will typically be added only after a high degree of conversion has already been attained. For instance, the coupling agent will normally be added only after a monomer conversion of greater than about 90 percent has been realized. It will typically be preferred for the monomer conversion to reach at least about 95 percent before the coupling agent is added. As a general rule, it is most preferred for the monomer conversion to exceed about 98 percent before the coupling agent is added. The coupling agents will normally be added in a separate reaction vessel after the desired degree of conversion has been attained. The coupling agents can be added in a hydrocarbon solution, e.g., in cyclohexane, to the polymerization admixture with suitable mixing for distribution and reaction.
In cases where the rubbery polymer will be used in compounds that are loaded primarily with carbon black, the coupling agent will typically be a tin halide. The tin halide will normally be a tin tetrahalide, such as tin tetrachloride, tin tetrabromide, tin tetrafluoride or tin tetraiodide. However, tin trihalides can also optionally be used. Polymers coupled with tin trihalides having a maximum of three arms. This is, of course, in contrast to polymers coupled with tin tetrahalides which have a maximum of four arms. To induce a higher level of branching, tin tetrahalides are normally preferred. As a general rule, tin tetrachloride is most preferred. However, silicon monohalides and/or tin monohalides can be used the shortstop the polymerization (kill the living polymer) and to functionalize the polymer without coupling.
In cases where the rubbery polymer will be used in compounds that are loaded with high levels of silica, the coupling agent will typically be a silicon halide. The silicon coupling agents that can be used will normally be silicon tetrahalides, such as silicon tetrachloride, silicon tetrabromide, silicon tetrafluoride or silicon tetraiodide. However, silicon trihalides can also optionally be used. Polymers coupled with silicon trihalides having a maximum of three arms. This is, of course, in contrast to polymers coupled with silicon tetrahalides which have a maximum of four arms. To induce a higher level of branching, silicon tetrahalides are normally preferred. As a general rule, silicon tetrachloride is most preferred of the silicon coupling agents.
A combination of a tin halide and a silicon halide can optionally be used to couple the rubbery polymer. By using such a combination of tin and silicon coupling agents improved properties for tire rubbers, such as lower hysteresis, can be attained. It is particularly desirable to utilize a combination of tin and silicon coupling agents in tire tread compounds that contain both silica and carbon black. In such cases, the molar ratio of the tin halide to the silicon halide employed in coupling the rubbery polymer will normally be within the range of 20:80 to 95:5. The molar ratio of the tin halide to the silicon halide employed in coupling the rubbery polymer will more typically be within the range of 40:60 to 90:10. The molar ratio of the tin halide to the silicon halide employed in coupling the rubbery polymer will preferably be within the range of 60:40 to 85:15. The molar ratio of the tin halide to the silicon halide employed in coupling the rubbery polymer will most preferably be within the range of 65:35 to 80:20.
Broadly, and exemplary, a range of about 0.01 to 4.5 milliequivalents of tin coupling agent (tin halide and silicon halide) is employed per 100 grams of the rubbery polymer. It is normally preferred to utilize about 0.01 to about 1.5 milliequivalents of the coupling agent per 100 grams of polymer to obtain the desired Mooney viscosity. The larger quantities tend to result in production of polymers containing terminally reactive groups or insufficient coupling. One equivalent of tin coupling agent per equivalent of lithium is considered an optimum amount for maximum branching. For instance, if a mixture tin tetrahalide and silicon tetrahalide is used as the coupling agent, one mole of the coupling agent would be utilized per four moles of live lithium ends. In cases where a mixture of tin trihalide and silicon trihalide is used as the coupling agent, one mole of the coupling agent will optimally be utilized for every three moles of live lithium ends. The coupling agent can be added in a hydrocarbon solution, e.g., in cyclohexane, to the polymerization admixture in the reactor with suitable mixing for distribution and reaction.
After the coupling has been completed, a tertiary chelating alkyl 1,2-ethylene diamine or a metal salt of a cyclic alcohol can optionally be added to the polymer cement to stabilize the coupled rubbery polymer. The tertiary chelating amines that can be used are normally chelating alkyl diamines of the structural formula:
wherein n represents an integer-from 1 to about 6, wherein A represents an alkylene group containing from 1 to about 6 carbon atoms and wherein R′, R″, R′″ and R″″ can be the same or different and represent alkyl groups containing from 1 to about 6 carbon atoms. The alkylene group A is of the formula —(—CH 2 —) m wherein m is an integer from 1 to about 6. The alkylene group will typically contain from 1 to 4 carbon atoms (m will be 1 to 4) and will preferably contain 2 carbon atoms. In most cases, n will be an integer from 1 to about 3 with it being preferred for n to be 1. It is preferred for R′, R″, R′″ and R″″ to represent alkyl groups which contain from 1 to 3 carbon atoms. In most cases, R′, R′″, R′″ and R″″ will represent methyl groups.
In most cases, from about 0.01 phr (parts by weight per 100 parts by weight of dry rubber) to about 2 phr of the chelating alkyl 1,2-ethylene diamine or metal salt of the cyclic alcohol will be added to the polymer cement to stabilize the rubbery polymer. Typically, from about 0.05 phr to about 1 phr of the chelating alkyl 1,2-ethylene diamine or metal salt of the cyclic alcohol will be added. More typically, from about 0.1 phr to about 0.6 phr of the chelating alkyl 1,2-ethylene diamine or the metal salt of the cyclic alcohol will be added to the polymer cement to stabilize the rubbery polymer.
After the polymerization, coupling, and optionally the stabilization step, has been completed, the coupled rubbery polymer containing polysiloxane can be recovered from the organic solvent The coupled rubbery polymer can be recovered from the organic solvent and residue by means such as decantation, filtration, centrification and the like. It is often desirable to precipitate the coupled rubbery polymer from the organic solvent by the addition of lower alcohols containing from about 1 to about 4 carbon atoms to the polymer solution. Suitable lower alcohols for precipitation of the rubber from the polymer cement include methanol, ethanol, isopropyl alcohol, normal-propyl alcohol and t-butyl alcohol The utilization of lower alcohols to precipitate the asymmetrically tin-coupled rubbery polymer from the polymer cement also “kills” any remaining living polymer by inactivating lithium end groups. After the coupled rubbery polymer is recovered from the solution, steam-stripping can be employed to reduce the level of volatile organic compounds in the coupled rubbery polymer.
The functionalized polysiloxane containing rubbers that are made by the process of this invention are of the structural formula:
wherein X represents a group IVa element selected from the group consisting of carbon, silicon, germanium, and tin, wherein n represents an integer from 1 to 10, wherein m represents an integer from about 1000 to about 10,000, wherein p represents an integer from about 2 to about 50, wherein R and R′ represents alkyl groups that can be the same or different, and wherein the alkyl groups contain from 1 to about 8 carbon atoms. The functionalized polysiloxane containing rubber will typically have a number average molecular weight which is within the range of about 50,000 to about 500,000. The functionalized polysiloxane containing rubber will more typically have a number average molecular weight which is within the range of about 100,000 to about 400,000.
The coupled rubbery polymers that can be made by using the technique of this invention are comprised of a tin and/or silicon atoms having at least three polydiene arms covalently bonded thereto. The asymmetrically coupled rubbery polymers containing polysiloxane that can be made by the process of this invention contain stars of the structural formula:
wherein M represents silicon or tin, wherein R 1 , R 2 , R 3 and R 4 can be the same or different and are selected from the group consisting of alkyl groups containing from 1 to about 8 carbon atoms, and rubbery polymer arms of the structural formula:
wherein X represents a group IVa element selected from the group consisting of carbon, silicon, germanium, and tin, wherein n represents an integer from 1 to 10, wherein m represents an integer from about 1000 to about 10,000, wherein p represents an integer from about 2 to about 50, wherein R and R′ represents alkyl groups that can be the same or different, and wherein the alkyl groups contain from 1 to about 8 carbon atoms, and wherein at least three members selected from the group consisting of R 1 , R 2 , R 3 and R 4 are rubbery polymer arms. In most cases, four rubbery arms will be covalently bonded to the tin atom or the silicon atom in the tin-coupled rubbery polymer. In such cases, R 1 , R 2 , R 3 and R 4 will all be rubbery polymer arms.
This invention is illustrated by the following examples which are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. Unless specifically indicated otherwise, all parts and percentages are given by weight.
EXAMPLE 1
In this experiment, a functionalized polyisoprene containing polydimethylsiloxane (PDMS) was synthesized. In the procedure used, 1000 grams of silica/alumina/molecular sieve dried premix containing 20 weight percent isoprene in hexane was charged into a reactor having a capacity of 1 gallon (3.8 liters). Then, 0.8 cc of 3-(t-butyldimethylsilyloxy)-1-propyllithium (0.72 M in hexane) was added to the reactor to initiate polymerization. The polymerization was allowed to proceed at 65° C. for 2 hours A small amount of tetrahydrofuran was added to the viscous polymer solution that formed. After full conversion, a polymer sample was taken and characterized by GPC. The molecular weight of the polyisoprene segment was 350,000 and the molecular weight distribution was only 1.03. At that point, hexamethylcyclotrisiloxane monomer was added and allowed to copolymerize at room temperature for about 48 hours. The polymerization was subsequently terminated by the addition of trimethylchlorosilane (1 M in THF). The polymer was subsequently dried and analyzed. The NMR analysis showed that the copolymer produced contained 92 percent 1,4-polyisoprene units, 7.4 percent 3,4-polyisoprene units, and 0.6 percent PDMS.
EXAMPLE 2
In this experiment the general procedure described in Example 1 was used to prepare an isoprene-butadiene rubber (IBR) containing a block of PDMS. In the procedure used, 1000 grams of silica/alumina/molecular sieve dried premix containing 20 weight percent isoprene and 1,3-butadiene monomers in hexane was charged into the reactor. The ratio of isoprene to 1,3-butadiene was 40:60. The molecular weight of the isoprene-butadiene segment was 140,000 g/mole and the molecular weight distribution was only 1.01. Hexamethylcyclotrisiloxane monomer was again added and allowed to polymerize at room temperature. The polymerization was subsequently terminated by the addition of trimethylchlorosilane (1 M in THF). The polymer was subsequently dried and analyzed.
While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention.
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The present invention relates to an anionic polymerization technique for synthesizing functionalized rubbery polymers containing polysiloxane that have excellent characteristics for utilization in (a) tire tread compounds that are highly loaded with silica, (b) shiny tire side-wall compounds, and (c) tire building bladders having improved mold release characteristics. The rubbery polymers of this invention can optionally be coupled with tin halides or silicon halides to further improve the characteristics of the rubber for use in tire tread compounds. The present invention more specifically discloses a process for synthesizing a rubbery polymer that comprises (1) polymerizing at least one conjugated diolefin monomer to produce a living rubbery polymer, wherein said polymerization is optionally carried out in the presence of a polar modifier, wherein said polymerization is an anionic polymerization that is initiated with an alkylsilyloxy protected functional lithium initiator having a structural formula selected from the group consisting:
wherein X represents a group IVa element selected from the group consisting of carbon, silicon, germanium, and tin, wherein Y represents phosphorous or nitrogen, wherein R represents alkyl groups that can be the same or different, wherein the alkyl groups contain from 1 to about 8 carbon atoms, and wherein A represents an alkylene group containing from 1 to about 8 carbon atoms; (2) adding a hexaalkylcyclotrisiloxane monomer to the living rubbery polymer; (3) allowing the hexaalkylcyclotrisiloxane monomer to polymerize to produce a living polysiloxane containing rubber; and optionally, (4) reacting the living polysiloxane containing rubber with a coupling agent selected from the group consisting of tin halides and silicon halides to produce a coupled polysiloxane containing rubber.
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[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 61/084,504 filed Jul. 29, 2008, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] I. Field of the Invention
[0003] Embodiments of this invention are directed generally to immunology and medicine. In certain embodiments the invention is directed to detection of autoreactive immune cell (B cell) that recognize the acetylcholine receptor.
[0004] II. Background
[0005] Myasthenia gravis (MG) is a human autoimmune disorder characterized by muscle weakness and fatigability. In this disease, antibodies against the acetylcholine receptor (AChR) bind to the receptor and destroy the receptor and thus interfere with the transmission of signals from nerve to muscle at the neuromuscular junction (Patrick and Lindstrom, 1973).
[0006] The acetylcholine receptor molecule is a transmembrane glycoprotein consisting of five subunits, two α, one β, one δ, with either an ε of γ subunit, organized in a barrel-staves-like structure around a central cation channel (Karlin, 1980; Changeux et al., 1984). Noda et al. (1983) described the cloning and sequence analysis of human genomic DNA encoding the α-subunit precursor of muscle acetylcholine receptor, and Schoepfer et al. (1988) reported the cloning of the α-subunit cDNA from the human cell line TE671. Human muscle AChR α-subunit exists in two forms, one of which has 25 additional amino acid residues, inserted between positions 58 and 59, that are coded by the 75 by exon p3A (Beeson et al., 1990). The α-subunit of AChR contains both the site for acetylcholine binding and is the immunodominant region for anti-AChR immune responses. However, antibodies have been detected against all subunits of AChR.
[0007] The autoimmune response in myasthenia gravis is directed mainly towards the extracellular domain of the AChR α-subunit (amino acids 1-210), and within it, primarily towards the main immunogenic region (MIR) encompassing amino acids 61-76 (Tzartos and Lindstrom, 1980; Tzartos et al., 1987; Loutrari et al., 1992). Many antibodies to the MIR bind only to the native conformation of the α subunits because they bind to sequences that are adjacent only in the native structure.
[0008] MG is currently treated by acetylcholinesterase inhibitors and by non-specific immunosuppressive drugs that have deleterious side effects. It would be preferable to treat MG with a method that involves antigen-specific immunotherapy but leaves the overall immune response intact. One such strategy of specific therapy could involve the administration of derivatives of AChR that do not induce myasthenia but are capable of affecting the immunopathogenic antibodies. However, since the anti-AChR antibody repertoire in myasthenia gravis has been shown to be polyclonal and heterogeneous (Drachman, 1994), the regulation of the disease requires modulation of many antibody specificities.
[0009] Previous studies were directed towards modulating the anti-AChR response and EAMG by either derivatives of Torpedo AChR, e.g., the reduced and carboxymethylated derivative, RCM-AChR (Bartfeld and Fuchs, 1978), synthetic peptides corresponding to Torpedo acetylcholine receptor (Shenoy et al., 1993), specific regions of AChR (Shenoy et al., 1993; Souroujon et al., 1992; Souroujon et al., 1993), or mimotopes selected from an epitope library (Balass et al., 1993). The Torpedo RCM-AChR did not induce EAMG in rabbits and was effective in suppressing the disease. However, RCM-AChR did induce EAMG in rats. The experiments carried out with the synthetic peptides and mimotopes were only partially successful in neutralizing MG autoimmune response, probably due to the incorrect folding of the short peptides that were recognized by only a portion of the anti-AChR antibodies and ineffective tolerance to acetylcholine receptor specific B cells.
[0010] MG is currently diagnosed by testing for antibodies against AChR by radioimmunoassay wherein the antigen is crude AChR extracted from human muscle or TE671 cells. This test presents some drawbacks, namely the antigen is not readily available and, in addition, the antibody titers detected are not well correlated with disease severity.
[0011] Thus, additional methods and compositions that are both reliable and convenient diagnostic test is needed.
SUMMARY OF THE INVENTION
[0012] Myasthenia Gravis is a chronic autoimmune condition characterized by fluctuating voluntary muscle weakness. Antibodies to acetylcholine receptors (AChR) destroy AChR in the neuromuscular junctions leading to MG. Symptoms of MG include fatigue, muscle weakness, double vision, drooping eyelids, and difficulty chewing or swallowing and in severe disease paralysis and respiratory distress. Currently, diagnosis of MG involves a combination of clinical history, nerve stimulation tests, and blood test for serum antibodies against AChR. Although serum antibodies to AChR are diagnostic for MG, the antibody titer does not correlate with disease severity and around 15% of patients with MG do not have serum antibodies to AChR. Therefore, a better marker for disease state is required to evaluate the clinical effectiveness of specific drugs in MG. Also the current test for anti-AChR antibodies, either radioimmunoassay or ELISA takes two days and has to be performed in special Medical centers like Mayo Clinic. The inventors have developed a simple novel reagent and/or kit comprising AChR conjugates, such as an Alexa-AChR conjugate, for flowcytometry of patient blood. The methods described herein typically use no radioactivity, and can screen MG patient blood samples in little over an hour for increased frequency of AChR+ B cells. This test could be performed in any hospitals or institutions having a FACS machine or access to such a facility or service. Since anti-AChR antibodies are secreted versions of the membrane bound B cell receptor (BCR) in MG patients, the inventors use AChR conjugates, e.g., Alexa-fluor AChR conjugates, to identify pathogenic AChR-specific B cells in blood of MG patients.
[0013] The present invention provides methods for monitoring MG in a subject comprising the steps of determining the presence and/or number of AChR reactive B-cells in a sample from the subject, determining the levels in a control sample, and assessing MG status in the subject relative to the control. Furthermore, this invention also describes how one can isolate and assess the function and biology of specific autoreactive cells that bind AChR.
[0014] Certain aspects of the invention includes methods of evaluating a patient for or with Myasthenia Gravis comprising the steps of: (i) contacting a sample comprising B cells with an acetylcholine receptor (AChR) conjugate; (ii) determining a level of AChR binding B cells in a sample; and (iii) comparing the level of AChR reactive B-cells with a reference or standard. In certain aspects the sample is a blood sample. In a further aspect the AChR conjugate comprises a fluorophore, such as, but not limited to Alexa fluorophore (e.g., Alexa-488 or Alexa-647). In other aspects determining a level of AChR binding B cells is by flow cytometry.
[0015] In other aspects the method can further comprise contacting the sample with B cell marker binding agent, such as but not limited to an antibody that binds a cell surface molecule including, but not limited to IgG, CD19, CD21, CD45R, CD20, CD22, CD23, and/or CD81.
[0016] In still further aspects, the methods can further comprise administering a treatment for myasthenia gravis.
[0017] In yet a further aspect includes a reagent and/or device for evaluating a patient of myasthenia gravis comprising an AChR conjugate.
[0018] In certain aspects the invention is directed to an acetylcholine receptor conjugate comprising at least 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 30, 50, 100 or more consecutive amino acids, including all values and ranges there between of an AChR polypeptide coupled to a detectable moiety.
[0019] Also contemplated are kits for detecting acetylcholine receptor reactive B cells comprising an acetylcholine receptor conjugate.
[0020] Certain aspects are also directed to methods of evaluating a patient for or with an autoimmune condition comprising the steps of: (i) contacting a sample comprising B cells with a protein or peptide conjugate that specifically binds a B cell associated with the autoimmune condition; (ii) determining a level of conjugate binding B cells in a sample; and (iii) comparing the level of conjugate reactive B-cells with a reference or standard. In certain aspects the autoimmune condition is MG, SLE or rheumatoid arthritis.
[0021] As used herein, the term “B cell” refers to a cell produced in the bone marrow expressing membrane-bound antibody specific for an antigen, in this case AChR. Following interaction with the antigen it differentiates into a plasma cell which secretes antibodies specific for the antigen or into a memory B cell. “B cell” and “B lymphocyte” is used interchangeably.
[0022] As used herein, the term “antigen-specific B cell” refers to a B cell which expresses antibodies that are able to distinguish between the antigen of interest (e.g., AChR) and other antigens and which specifically bind to that antigen of interest with high or low affinity but which do not bind to other antigens.
[0023] A “positive B cell” means any B cell which is labeled with any one of the labeling compounds of the invention and which is selected or sorted or otherwise separated from a mixture of cells by a device capable of detecting said labeling compound. For example, a B cell which is positive for a labeling compound of the invention is a B cell which is labeled with a labeling compound and which is selected by the device capable of detecting the labeling compound.
[0024] As used herein, the term “B cell marker” refers to surface molecules on the B cells which are specific for particular B cells. B cell markers suitable for use in the present invention include, but are not limited to surface IgG, kappa and lambda chains, Ig-alpha (CD79alpha), Ig-beta (CD79beta), CD19, B220 (CD45R), CD20, CD21, CD22, CD23, CD27, or any other CD antigen specific for B cells.
[0025] The term “bind” or “bound” refers to binding or attachment that may be covalent, e.g., by chemically coupling, or non-covalent, e.g., ionic interactions, hydrophobic interactions, hydrogen bonds, etc. Covalent bonds can be, for example, ester, ether, phosphoester, amide, peptide, imide, carbon-sulfur bonds, carbon-phosphorus bonds, and the like. The term “bound” is broader than and includes terms such as “coupled,” “fused,” “associated,” and “attached.”
[0026] As used herein, the term “labeling compound” refers to a compound used to label the AChR polypeptides or one or more B cell markers of the invention either directly or indirectly through, for example, a covalent bond, a tag, antibody, dioxigenin, or biotin. Such labels suitable for use in the present invention are well known in the art and include, but are not limited to fluorescent materials (e.g., PerCP, Allophycocyanin (APC), texas red, rhodamine, Cy3, Cy5, Cy5.5, Cy7, Alexa Fluor Dyes, phycoerythrin (PE), green fluorescent protein (GFP), a tandem dye (e.g., PE-Cy5), fluorescein isothiocyanate (FITC)), magnetic beads, radiolabel (e.g., 131 I-labeled antibody, 90 Y (a pure beta emitter)-labeled antibody, 211 At-labeled antibody), an enzyme, avidin or biotin, or any other tag or label known in the art useful for labeling AChR polypeptide and/or at least a second B cell marker.
[0027] The composition of the invention can be labeled prior to or after contacting a sample comprising a mixture of cells with an AChR polypeptide. The AChR polypeptide can be labeled with a labeling compound such as avidin or biotin, dioxigenin, flag tag or any other tag known in the art. A detectable moiety can then be bound to the AChR polypeptide through a covalent bond, a labeled streptavidin, anti-dioxigenin, anti-flag or any other anti-tag. The sample may also be contacted with a second composition comprising an antibody to one or more B cell marker. Detectable moieties include, but are not limited to fluorescent materials, magnetic particles or radiolabels.
[0028] In one embodiment, two or more samples may be taken from a subject. A first sample can be taken from the subject before treatment with a therapeutic agent, which for example, establishes a baseline to compare subsequent sample(s). A second sample can then be taken after treatment with the therapeutic agent to assess the effects of treatment.
[0029] In another embodiment, the test sample is from the subject who has or is suspected of having MG and the control sample is from a subject that does not have MG. In certain aspects, these methods and compositions are useful for determining B cell levels in any subject for whom the knowledge of the B cell levels in the subject would be helpful in treating or managing MG. Therefore, this method can be useful for monitoring or treating subjects having or suspected of having MG or monitoring a subject with MG. Thus, this method is useful for monitoring B cells associated with MG.
[0030] The present invention also provides kits and articles of manufacture for assaying AChR reactive B-cells levels in a subject. A kit may comprise AChR conjugate and one or more detectable moieties as well the reagents needed to express, purify, manipulate, and/or label an AChR polypeptide.
[0031] Other embodiments of this invention also include similar conjugation procedure to conjugate Alexa or other dyes with proteins or peptides that bind to B cells associated with other autoimmune diseases to detect frequency of antigen specific B cells in these diseases. Examples of autoimmune diseases and relevant proteins (autoantigens) involved in the development of these autoimmune diseases are given in Table 1. A conjugate of these autoantigens are contemplated for the assessment of these autoimmune disorders.
[0000]
TABLE 1
Other autoimmune diseases and their autoantigen(s).
Autoimmune Diseases
Autoantigens
Systemic lupus
DNA, RNA, Smith (SM) antigen
erythematous (SLE)
Hashimoto's thyroiditis
Thyroglobulin (Tg)
Uveitis
Interphotoreceptor retinoid binding
protein (IRBP)
Rheumatoid arthritis (RA)
Type II collagen, rheumatoid factor
Type I diabetes (IDDM)
Islet b cell antigens, glutamic acid
decarboxylase (GAD), and insulin
Graves' disease
Thyroid stimulatory hormone receptor
(Thyrotoxicosis)
(TSHR)
Goodpasture's syndrome
Type IV collagen
Pemphigus vulgaris
Desmoglein 2
Pemphigoid
Epidermal basement membrane protein
Pernicious anemia
Intrinsic factor, gastric parietal cell
antigen
Addison's disease
Adrenal gland antigen
Autoimmune haemolytic
Erythrocyte membrane protein
anemia
Idiopathic
Platelet membrane protein
thrombocytopenic purpura
Multiple sclerosis
Myelin basic protein (MBP). Myelin
oligodendrocyte glycoprotein (MOG),
proteolipid protein (PLP)
Primary bilary cirrhosis
Pyruvate dehydrogenase
Celiac disease
Gluten (gliadin)
Vasculitis
Neutrophil cytoplasmic antigen
Sjogren's syndrome
Ribonucleoprotein antigens (RO/SSA and
La/SSB)
[0032] Other embodiments of the invention are discussed throughout this application. Any embodiment discussed with respect to one aspect of the invention applies to other aspects of the invention as well and vice versa. The embodiments in the Example section are understood to be embodiments of the invention that are applicable to all aspects of the invention.
[0033] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”
[0034] It is contemplated that any embodiment discussed herein can be implemented with respect to any method or composition of the invention, and vice versa. Furthermore, compositions and kits of the invention can be used to achieve methods of the invention.
[0035] Throughout this application, the term “about” is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value.
[0036] The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.”
[0037] As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.
[0038] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
DESCRIPTION OF THE DRAWINGS
[0039] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
[0040] FIG. 1A portion of affinity-purified AChR is run on an SDS-PAGE gel to test for high purity prior to labeling.
[0041] FIG. 2 Mature B cells (CD19+CD21) from CFA-AChR immunized mice have higher levels of Alexa-488 conjugated AChR+ splenocytes than naïve or CFA immunized mice.
[0042] FIG. 3 Identifying AChR-specific B cells (CD19+) from lymph node of CFA-AChR immunized mice.
[0043] FIG. 4 Alexa-488 conjugated AChR+ cells are responsible for in vitro proliferative responses to AChR. (A) Double positive B cells (B220+AChR+) from CFA-AChR immunized mice were depleted by flow cytometry and (B) then stimulated in vitro with AChR.
[0044] FIG. 5 The characterization of AChR-binding peripheral blood lymphocytes by flow cytometry. Representative flow cytometry analysis of peripheral blood lymphocytes from naïve, LPS-immunized or CFA+AChR-immunized (EAMG) mice, 75 to 80 days post primary immunization. Cells were first gated on lymphocytes and then analyzed for B220 expression and either AChR binding or OVAbinding (A). Then lymphocytes were gated on B220+ cells to characterize IgM (B) or IgG2 (C) expression and either AChR binding or OVA binding. The numbers shown in bi-exponential plots indicate the relative percentage of cells in each quadrant. The experiment was repeated 5 times with similar results.
[0045] FIG. 6 Inhibition of Alexa fluor-AChR-binding to peripheral blood B cells with unlabeled AChR. Representative flow cytometry staining of peripheral blood lymphocytes with (+) or without (−) blocking by incubating cells with (+) unlabeled AChR prior to staining with Alexa fluor-AChR; anti-B220 and anti-IgM, anti-IgG2, or isotype controls (A). The numbers shown in bi-exponential plots indicate the relative percentage of cells in each quadrant. The mean percentage of B-cell, AChR-binding subsets with (+) or without (−) blocking with unlabeled AChR (B). Each circle represents the frequency of AChR-binding B cells after 3 immunizations with CFA+AChR from individual mice having EAMG (n=5). The bar indicates the mean frequency of AChR-binding B cells. The data shown are from one experiment that was repeated three times. *P<0.05, **P<0.01, ***P<0.001. t-test.
[0046] FIG. 7 The kinetics on the frequencies of AChR-binding B cells. Shown is the mean percentage of subsets of peripheral blood B cells which are AChR-binding from naïve, LPS-immunized or CFA+AChR-immunized (EAMG) mice. Cells were analyzed as shown in FIG. 1 . Each square represents the frequency of the total AChR-binding B cells (top row), AChR-binding IgM+ B cells (middle row) or AChR-binding IgG2+ B cells (bottom row) from individual mice with EAMG after each immunization. Significant differences between populations were determined by ANOVA with Tukey's post hoc test and represented by a *P<0.05, **P<0.01, and ***P<0.001. Results shown are combined from multiple flow cytometry experiments with a total n=5-15 mice per group.
[0047] FIG. 8 Correlation between AChR-binding peripheral blood B cells and markers of disease severity. Each triangle represents the frequency of AChR-binding IgM+ (A&B) or IgG2+ (C&D) after 3 immunizations with CFA+AChR from individual mice with EAMG (clinical grades 1-3) and naïve mice (clinical grade 0) (n=5-7 per group). Clinical evaluation was completed at the time of blood draw (day 80). R is the Spearman coefficient between AChR-binding B-cell frequency and clinical grade (A&C) or grip strength loss represented by the grip strength ratio (B&D).
[0048] FIG. 9 Plasma concentration of secreted anti-AChR Igs does not correlate with the AChR-specific B-cell frequencies in mice with EAMG. Mean IgM (A) and IgG2 (C) expressing AChR-specific B-cell frequencies are shown by open squares with a broken line with SEM, and values are indicated on the left y-axis. Mean and SEM plasma anti-AChR IgM (A) and IgG2 (C) OD values determined by ELISA are shown by open circles with a solid line, and values are indicated on right axis. Spearman correlation between individual plasma anti-AChR IgM (B) or IgG2 (D) concentrations and the frequency of the AChR-binding B cells after day 42 post immunization. Each circle represents data from an individual mouse after each immunization with CFA and AChR. Black arrows indicate time of boost immunizations. Results shown are from one experiment with a total n=4-10 mice. Experiment was repeated with similar results. r, Spearman correlation coefficient; ns, not significant.
[0049] FIG. 10 Alexa-AxChR binding CD19+ B cells in patients with MG.
DETAILED DESCRIPTION OF THE INVENTION
[0050] Patients with the neuromuscular disease Myasthenia Gravis (MG) are characterized by pathogenic autoantibodies directed towards AChR (Aharonov et al., 1975). The α-subunit of AChR is the immunodominant antigen, and within it especially the extracellular domain. Experimental autoimmune myasthenia gravis (EAMG) is an antibody-mediated autoimmune disease of the neuromuscular junction in which AChR is the major autoantigen and which serves as a model for MG.
[0051] Human muscle AChR α-subunit exists as two isoforms consisting of 437 and 462 amino acid residues (Beeson et al., 1990). The two isoforms are identical in their amino acid composition except for a sequence of 25 additional amino acid residues inserted after position 58 in the extracellular domain of the longer variant. These additional amino acids are encoded by the 75 by exon p3A.
[0052] The AChR molecule in its native conformation structure, consisting of five subunits, two α, one β, one δ, with either an ε of γ subunits are included in present invention. However, this invention may be extended to fragments of AChR capable of binding and labeling a B-cell reactive with AChR as part of the present invention.
[0053] An “autoimmune disease,” such as Myasthenia Gravis, is a disease or disorder arising from and directed against an individual's own tissues or organs, or a resulting condition there from. In many autoimmune disorders a number of clinical and laboratory markers may exist including, but not limited to production of autoantibodies. Without being limited to any one theory regarding autoimmune disease, it is believed that B cells demonstrate a pathogenic effect in human autoimmune diseases through a multitude of mechanistic pathways, including autoantibody production, immune complex formation, dendritic and T-cell activation, cytokine synthesis, and/or direct chemokine release. Each of these pathways may participate to different degrees in the pathology of autoimmune diseases such as MG.
[0054] The term “determining” is intended to include any method for evaluating or measuring the amounts of a substance or cell type in a sample. Examples of comparative controls include, but are not limited to, sera from normal healthy patient samples or reference ranges derived the sampling an analysis of a number of subject known not to have MG.
I. Acetylcholine Receptor
[0055] An acetylcholine receptor (AChR) is an integral membrane protein that responds to the binding of the neurotransmitter acetylcholine. Human acetylcholine receptor consists of subunits, arising from five genes, CHRNA (e.g., Accession No. EAX11127 (GI:119631532); NP — 001034612 (GI:87567783); P02708 (GI:113071)), CHRNB2 (e.g., Accession No. CAI16184 (GI:55960912)), CHRND (e.g., Accession No. NP — 000742 (GI:4557461)), CHRNE (e.g., Accession No. AAD24503 (GI:4580859)), and CHRNG (e.g., Accession No. P07510 (GI:126302510)), each of which is incorporated herein by reference as of the filing date of this application.
[0056] Molecular biology has shown that the nicotinic and muscarinic receptors belong to distinct protein superfamilies. The nAChRs are ligand-gated ion channels, and, like other members of the “cys-loop” ligand-gated ion channel superfamily, are composed of five protein subunits symmetrically arranged like staves around a barrel. The subunit composition is highly variable across different tissues. Each subunit contains four regions named M1, M2, M3, and M4, which span the membrane and consist of approximately 20 amino acids. The M2 region, which sits closest to the pore lumen, forms the pore lining. Binding of acetylcholine to the N termini of each of the two alpha subunits results in the 15° rotation of all M2 helices. The cytoplasm side of the nAChR receptor has rings of high negative charge that determine the specific cation specificity of the receptor and remove the hydration shell often formed by ions in aqueous solution.
[0057] AChR is found at the edges of junctional folds at the neuromuscular junction on the postsynaptic side, and is activated by acetylcholine release across the synapse. The diffusion of Na+ and K+ across the receptor causes depolarization, the end-plate potential, that opens voltage-gated sodium channels, which allows for firing of the action potential and potentially muscular contraction.
[0058] A. Conjugates
[0059] The invention provides a conjugate that contains a detectable moiety linked to an AChR polypeptide (e.g., affinity purified AchR). In certain aspects, the AChR polypeptide portion of the conjugate can have, for example, a length of at least, at most, or about 5, 10, 20, 30, 40, 50, 100, 150, 200, 250, 300, 400, or 450 consecutive amino acid residues, including all values and ranges there between, of for example SEQ ID NOs 1-3. It is understood that the term “AChR polypeptide portion of the conjugate” means the total number of residues in the AChR conjugate. An AChR polypeptide portion of the present invention may be prepared by purification methods, recombinant methods, and/or synthetic methods, all of which are known to one skilled in the art.
[0060] The AChR polypeptide portion according to the present invention may be prepared by recombinant methods. For example, a DNA nucleotide encoding the polypeptide is constructed by a conventional methods. The construction of the DNA nucleotide may be performed by PCR amplification using a suitable primer. Otherwise, the DNA nucleotide may be constructed by a standard method known to one skilled in the art, for example, by an automatic DNA synthesizer (available from Biosearch or Applied Biosystems). The DNA nucleotide constructed as described above is inserted into a vector containing at least one expression control sequence (e.g., promoter, enhancer, or the like) that is operatively linked to the DNA nucleotide to control the expression of the DNA nucleotide, thereby providing a recombinant expression vector, which, in turn, is used to transform a host cell. The resultant transformed cell can be cultured in a suitable medium and a condition to perform the expression of the DNA sequence. Then, a substantially pure peptide encoded by the DNA nucleotide is recovered from the culture. Such recovery may be carried out by a method generally known to one skilled in the art (e.g., chromatography). As used herein, the term “substantially pure peptide” means a peptide according to the present invention does not substantially comprise any other proteins derived from a host. References to the genetic engineering method for preparing the peptide according to the present invention include: Maniatis et al., 1982; Sambrook et al., 2 nd Ed. (1998) and 3 rd Ed. (2000); Gene Expression Technology, 1991; and Hitzeman et al., 1990.
[0061] Typical examples of synthetic methods include, but are not limited to, liquid or solid phase synthesis, fragment condensation, F-MOC or T-BOC chemistry ((Creighton, Proteins; Structures and Molecular Principles, 1983; Chemical Approaches to the Synthesis of Peptides and Proteins, 1997; A Practical Approach, 1989).
[0062] In a particular example AChR can be purified from a protein source such a cell line expressing a recombinant polypeptide or from Torpedo Californica electric organs (Aquatic Research Consultants, CA) according to published methods (Wu et al. 1997). AChR conjugates can be made by incubating AChR with detectable moiety containing a reactive moiety such as a succinimidyl ester moiety or other know reactive moiety. AChR polypeptides can be concentrated by, for example, centrifugation with centrifugal filters. AChR polypeptide can then be dialyzed and AChR concentration can be determined. AChR can then be contacted with a detectable moiety and/or a labeling reagent. Labeled AChR can then be further purified and concentration of labeled protein determined.
[0063] A number of peptide labeling methods are well known. (See Haugland, 2003; Brinkley, 1992; Garman, 1997; Means and Feeney, 1990; Glazer et al., 1975; Lundblad and Noyes, 1984; Pfleiderer, 1985; Wong, 1991; De Leon-Rodriguez et al., 2004; Lewis et al., 2001; Li et al., 2002; Mier et al., 2005).
[0064] B. Labeling and labels
[0065] In certain aspects an AChR polypeptide is conjugated to a detectable moiety by at least one covalent bond. In one aspect the covalent bond is a non-peptide bond. Typically AChR polypeptide is conjugated to the detectable moiety by way of chemical cross-linking, e.g., by using a heterobifunctional cross-linker A hetero-bifunctional crosslinker contains a functional group which can react with preferred first attachment sites, i.e. chemical groups of the AChR polypeptide and a further functional group which can react with a preferred second attachment site available for reaction with or the detectable moiety, vice versa with the first attachment site on the detectable moiety and the second attachment site on the AChR polypeptide. In certain aspects the chemical group for attachment can be synthesized in the detectable moiety itself, detectable moiety can have one or more attachment group(s). The first step of the procedure, typically called the derivatization, is the reaction of AChR polypeptide or the detectable moiety with the cross-linker. The product of this reaction is an activated AChR polypeptide or detectable moiety. In a second step, unreacted cross-linker is removed using usual methods such as column filtration, gel filtration, or dialysis.
[0066] Several hetero-bifunctional cross-linkers are known to the art. These include the preferred cross-linkers SMPH (Pierce), Sulfo-MBS, Sulfo-EMCS, Sulfo-GMBS, Sulfo-SIAB, Sulfo-SMPB, Sulfo-SMCC, SVSB, SIA and other cross-linkers available for example from the Pierce Chemical Company (Rockford, Ill., USA). The above mentioned cross-linkers all lead to formation of a thioether linkage. Other cross-linkers include for example SPDP and Sulfo-LC-SPDP (Pierce). The extent of derivatization with cross-linker can be influenced by varying conditions such as the concentration of each of the reaction partners, the excess of one reagent over the other, the pH, the temperature and the ionic strength. The degree of coupling, i.e. the amount of detectable moiety per AChR polypeptide, respectively, can be adjusted by varying the experimental conditions described above to match the requirements of the method of the invention. In a certain embodiment of the invention, the AChR polypeptide may be coupled, fused, or otherwise attached to a surface or substrate or particle.
[0067] Detectable moieties include fluorescent groups that are capable of absorbing radiation at one wavelength and emitting radiation at a longer wavelength, such as, for example, Alexa (e.g., Alexa-532, Alexa-488, Alexa-647, etc.), Hydroxycoumarin, Aminocoumarin, Methoxycoumarin, Coumarin, Cascade Blue, Lucifer Yellow, P-Phycoerythrin, R-Phycoerythrin, (PE), PE-Cy5 conjugates, PE-Cy7 conjugates, Red 613, Fluorescein, BODIPY-FL, BODIPY TR, BODIPY TMR, Cy3, TRITC, X-Rhodamine, Lissamine Rhodamine B, PerCP, Texas Red, Cy5, Cy7, Allophycocyanin (APC), TruRed, APC-Cy7 conjugates, Oregon Green, Tetramethylrhodamine, Dansyl, Dansyl aziridine, Indo-1, Fura-2, FM 1-43, DilC18(3), Carboxy-SNARF-1, NBD, Indo-1, Fluo-3, DCFH, DHR, SNARF, Monochlorobimane, Calcein, N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amine (NBD), ananilinonapthalene, deproxyl, phthalamide, amino pH phthalamide, dimethylamino-naphthalenesulfonamide, probes comparable to Prodan, Lordan or Acrylodan and derivatives thereof. Coumarin fluorescent dyes include, for example, amino methylcoumarin, 7-diethylamino-3-(4′-(1-maleimidyl)phenyl)-4-methylcoumarin (CPM) and N-(2-(1-maleimidyl)ethyl)-7-diethylaminocoumarin-3-carboxamide (MDCC). Preferred fluorescent probes are sensitive to the polarity of the local environment and are available to those of skill in the art.
[0068] C. Detecting AChR Conjugate Binding
[0069] In addition to the above, the present invention also provides a kit for the evaluation, assessment, prognosis, and/or diagnosis of MG. The AChR polypeptide in the diagnosis kit may be prepared using the method as described above. In certain aspects, a labeled AChR will be provided. Additionally, in order to facilitate the identification, detection and determination of B cells according to the present invention the AChR polypeptide according to the present invention may be provided in a labeled form. In other words, the AChR polypeptide according to the present invention may be linked (covalently bonded or crosslinked) to a detectable label, i.e. provided as an AChR conjugate. Particular examples of the detectable label that may be used in the present invention include, in addition to those described above, color developing enzymes (e.g., peroxidase, alkaline phosphatase, etc.), radio isotopes (e.g., 125 I, 32 P, 35 S, 131 I, 124 I, 18 F, Tc99m etc.), chromophores, light emitting materials or fluorescent materials (e.g., FITC, RITC, etc.). In certain aspects the label is a fluorophore such as an Alexa fluorophore. Similarly, as the detectable label, it is possible to use an antibody epitope, substrate, cofactor, inhibitor or affinity ligand. Such labeling work may be performed during or after the preparation of the AChR polypeptide.
[0070] If a fluorescent material is used as the detectable material, evaluation of AChR reactive B cells may be performed by an immunofluorescence staining method. For example, after the AChR polypeptide according to the present invention, labeled with a fluorescent material, is allowed to react with a B cell, fluorescence caused by the AChR polypeptide may be detected by a number of devices. If any fluorescence is observed, the B cell is recognized as a AChR reactive B cell. Additionally, if an enzyme is used as the detectable label, absorbance is measured by the enzymatic color developing reaction of a substrate. On the other hand, if a radioactive material is used as the detectable label, radiation quantity is measured to detect an AChR reactive B cell, and thus to diagnose MG.
II. Polypeptides and Peptides
[0071] As used herein, a “protein” or “polypeptide” refers to a molecule comprising at least ten amino acid residues. In some embodiments, a wild-type version of a protein or polypeptide are employed, however, in many embodiments of the invention, a modified protein or polypeptide is employed to evaluate the immune status of a subject. The terms described above may be used interchangeably. A “modified protein” or “modified polypeptide” refers to a protein or polypeptide whose chemical structure, particularly its amino acid sequence, is altered with respect to the wild-type protein or polypeptide. In some embodiments, a modified protein or polypeptide has at least one modified activity or function (recognizing that proteins or polypeptides may have multiple activities or functions). It is specifically contemplated that a modified protein or polypeptide may be altered with respect to one activity or function yet retain a wild-type activity or function in other respects, such as binding affinity for AChR reactive B cells.
[0072] In certain embodiments the size of a protein or polypeptide (wild-type or modified) may comprise, but is not limited to, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 275, 300, 325, 350, 375, 400, 425, 450, amino molecules or greater, and any range derivable therein, or derivative of a corresponding amino sequence described or referenced herein. It is contemplated that polypeptides may be mutated by truncation, rendering them shorter than their corresponding wild-type form, but also they might be altered by fusing or conjugating a heterologous protein sequence with a particular function (e.g., for targeting or localization, for enhanced immunogenicity, for purification purposes, etc.).
[0073] As used herein, an “amino molecule” refers to any amino acid, amino acid derivative, or amino acid mimic known in the art. In certain embodiments, the residues of the proteinaceous molecule are sequential, without any non-amino molecule interrupting the sequence of amino molecule residues. In other embodiments, the sequence may comprise one or more non-amino molecule moieties. In certain aspects, the sequence of residues of the proteinaceous molecule may be interrupted by one or more non-amino molecule moieties. Accordingly, the term “proteinaceous composition” encompasses amino molecule sequences comprising at least one of the 20 common amino acids in naturally synthesized proteins, or at least one modified or unusual amino acid.
[0074] Proteinaceous compositions may be made by any technique known to those of skill in the art, including (i) the expression of proteins, polypeptides, or peptides through standard molecular biological techniques, (ii) the isolation of proteinaceous compounds from natural sources, or (iii) the chemical synthesis of proteinaceous materials. The nucleotide as well as the protein, polypeptide, and peptide sequences for various AChR receptors are disclosed herein, and with a number of other AChR proteins and nucleic acids that can be found in the recognized computerized databases. One such database is the National Center for Biotechnology Information's GenBank and GenPept databases (on the World Wide Web at ncbi.nlm.nih.gov/). The coding regions for these genes may be amplified and/or expressed using the techniques disclosed herein or as would be know to those of ordinary skill in the art.
[0075] Amino acid sequence variants of AChR and other polypeptides of the invention can be substitutional, insertional, or deletion variants. A modification in a polypeptide of the invention may affect 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399, 400, or more non-contiguous or contiguous amino acids of the polypeptide, as compared to wild-type.
[0076] Deletion variants typically lack one or more residues of the native or wild-type protein. Individual residues can be deleted or a number of contiguous amino acids can be deleted. A stop codon may be introduced (by substitution or insertion) into an encoding nucleic acid sequence to generate a truncated protein. Insertional mutants typically involve the addition of material at a non-terminal point in the polypeptide. This may include the insertion of one or more residues. Terminal additions, called fusion proteins, may also be generated.
[0077] Substitutional variants typically contain the exchange of one amino acid for another at one or more sites within the protein, and may be designed to modulate one or more properties of the polypeptide, with or without the loss of other functions or properties. Substitutions may be conservative, that is, one amino acid is replaced with one of similar shape and charge. Conservative substitutions are well known in the art and include, for example, the changes of: alanine to serine; arginine to lysine; asparagine to glutamine or histidine; aspartate to glutamate; cysteine to serine; glutamine to asparagine; glutamate to aspartate; glycine to proline; histidine to asparagine or glutamine; isoleucine to leucine or valine; leucine to valine or isoleucine; lysine to arginine; methionine to leucine or isoleucine; phenylalanine to tyrosine, leucine or methionine; serine to threonine; threonine to serine; tryptophan to tyrosine; tyrosine to tryptophan or phenylalanine; and valine to isoleucine or leucine. Alternatively, substitutions may be non-conservative such that a function or activity of the polypeptide is affected. Non-conservative changes typically involve substituting a residue with one that is chemically dissimilar, such as a polar or charged amino acid for a nonpolar or uncharged amino acid, and vice versa.
[0078] Proteins of the invention may be recombinant, or synthesized in vitro. Alternatively, a non-recombinant or recombinant protein may be isolated from bacteria or other expression host known in the art.
[0079] The term “functionally equivalent codon” is used herein to refer to codons that encode the same amino acid, such as the six codons for arginine or serine, and also refers to codons that encode biologically equivalent amino acids (see Table below).
[0000]
TABLE 2
Codon Table
Amino Acids
Codons
Alanine
Ala
A
GCA GCC GCG GCU
Cysteine
Cys
C
UGC UGU
Aspartic acid
Asp
D
GAC GAU
Glutamic acid
Glu
E
GAA GAG
Phenylalanine
Phe
F
UUC UUU
Glycine
Gly
G
GGA GGC GGG GGU
Histidine
His
H
CAC CAU
Isoleucine
Ile
I
AUA AUC AUU
Lysine
Lys
K
AAA AAG
Leucine
Leu
L
UUA UUG CUA CUC CUG CUU
Methionine
Met
M
AUG
Asparagine
Asn
N
AAC AAU
Proline
Pro
P
CCA CCC CCG CCU
Glutamine
Gln
Q
CAA CAG
Arginine
Arg
R
AGA AGG CGA CGC CGG CGU
Serine
Ser
S
AGC AGU UCA UCC UCG UCU
Threonine
Thr
T
ACA ACC ACG ACU
Valine
Val
V
GUA GUC GUG GUU
Tryptophan
Trp
W
UGG
Tyrosine
Tyr
Y
UAC UAU
[0080] It also will be understood that amino acid and nucleic acid sequences may include additional residues, such as additional N- or C-terminal amino acids, or 5′ or 3′ sequences, respectively, and yet still be essentially as set forth in one of the sequences disclosed herein, so long as the sequence meets the criteria set forth above, including the maintenance of biological protein activity where protein expression is concerned. The addition of terminal sequences particularly applies to nucleic acid sequences that may, for example, include various non-coding sequences flanking either of the 5′ or 3′ portions of the coding region.
[0081] The following is a discussion based upon changing of the amino acids of a protein to create an equivalent, or even an improved, second-generation molecule. For example, certain amino acids may be substituted for other amino acids in a protein structure without appreciable loss of or even an increase in the interactive binding capacity with AChR reactive B cells. Since it is the interactive capacity and nature of a protein that defines that protein's biological functional activity, certain amino acid substitutions can be made in a protein sequence, and in its underlying DNA coding sequence, and nevertheless produce a protein with like properties. It is thus contemplated by the inventors that various changes may be made in sequences encoding AChR polypeptides without appreciable loss of their biological utility or activity.
[0082] In making such changes, the hydropathic index of amino acids may be considered. The importance of the hydropathic amino acid index in conferring interactive biologic function on a protein is generally understood in the art (Kyte and Doolittle, 1982). It is accepted that the relative hydropathic character of the amino acid contributes to the secondary structure of the resultant protein, which in turn defines the interaction of the protein with other molecules, for example enzymes, substrates, cell surface receptors, DNA, antibodies, antigens, and the like. It also is understood in the art that the substitution of like amino acids can be made effectively on the basis of hydrophilicity. U.S. Pat. No. 4,554,101, incorporated herein by reference, states that the greatest local average hydrophilicity of a protein, as governed by the hydrophilicity of its adjacent amino acids, correlates with a biological property of the protein. It is understood that an amino acid can be substituted for another having a similar hydrophilicity value and still produce a biologically equivalent and immunologically equivalent protein.
[0083] A. Polypeptides and Polypeptide Production
[0084] The present invention describes polypeptides, peptides, and proteins for use in various embodiments of the present invention. For example, specific polypeptides are used to evaluate AChR autoreactivity. In specific embodiments, all or part of the proteins of the invention can also be synthesized in solution or on a solid support in accordance with conventional techniques. Various automatic synthesizers are commercially available and can be used in accordance with known protocols. See, for example, Stewart and Young, (1984); Tam et al., (1983); Merrifield, (1986); and Barany and Merrifield (1979), each incorporated herein by reference. Alternatively, recombinant DNA technology may be employed wherein a nucleotide sequence which encodes a peptide of the invention is inserted into an expression vector, transformed or transfected into an appropriate host cell and cultivated under conditions suitable for expression.
[0085] One embodiment of the invention includes the use of gene transfer to cells, including microorganisms, for the production and/or presentation of proteins. The gene for the protein of interest may be transferred into appropriate host cells followed by culture of cells under the appropriate conditions. A nucleic acid encoding virtually any polypeptide may be employed. The generation of recombinant expression vectors, and the elements included therein, are discussed herein. Alternatively, the protein to be produced may be an endogenous protein normally synthesized by the cell used for protein production.
[0086] A number of selection systems may be used including, but not limited to HSV thymidine kinase, hypoxanthine-guanine phosphoribosyltransferase, and adenine phosphoribosyltransferase genes, in tk-, hgprt- or aprt-cells, respectively. Also, anti-metabolite resistance can be used as the basis of selection: for dhfr, which confers resistance to trimethoprim and methotrexate; gpt, which confers resistance to mycophenolic acid; neo, which confers resistance to the aminoglycoside G418; and hygro, which confers resistance to hygromycin.
III. Nucleic Acids
[0087] In certain embodiments, the present invention concerns recombinant polynucleotides encoding the proteins, polypeptides, peptides of the invention. The nucleic acid sequences for AChR polypeptides are included, all of which are incorporated by reference, and can be used to prepare an AChR polypeptide conjugate.
[0088] As used in this application, the term “polynucleotide” refers to a nucleic acid molecule that either is recombinant or has been isolated free of total genomic nucleic acid. Included within the term “polynucleotide” are oligonucleotides (nucleic acids 100 residues or less in length), recombinant vectors, including, for example, plasmids, cosmids, phage, viruses, and the like. Polynucleotides include, in certain aspects, regulatory sequences, isolated substantially away from their naturally occurring genes or protein encoding sequences. Polynucleotides may be RNA, DNA, analogs thereof, or a combination thereof.
[0089] In this respect, the term “gene,” “polynucleotide,” or “nucleic acid” is used for to refer to a nucleic acid that encodes a protein, polypeptide, or peptide (including any sequences required for proper transcription, post-translational modification, or localization). As will be understood by those in the art, this term encompasses genomic sequences, expression cassettes, cDNA sequences, and smaller engineered nucleic acid segments that express, or may be adapted to express, proteins, polypeptides, domains, peptides, fusion proteins, and mutants. A nucleic acid encoding all or part of a polypeptide may contain a contiguous nucleic acid sequence encoding all or a portion of such a polypeptide of 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 441, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, 800, 810, 820, 830, 840, 850, 860, 870, 880, 890, 900, 910, 920, 930, 940, 950, 960, 970, 980, 990, 1000, 1010, 1020, 1030, 1040, 1050, 1060, 1070, 1080, 1090, 1095, 1100, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 9000, 10000, or more amino acids of a polypeptide of the invention. It also is contemplated that a particular polypeptide may be encoded by nucleic acids containing variations having slightly different nucleic acid sequences but, nonetheless, encode the same or substantially similar protein.
[0090] In particular embodiments, the invention concerns isolated nucleic acid segments and recombinant vectors incorporating nucleic acid sequences that encode an AChR polypeptide. The term “recombinant” may be used in conjunction with a polypeptide or the name of a specific polypeptide, and this generally refers to a polypeptide produced from a nucleic acid molecule that has been manipulated in vitro or that is a replication product of such a molecule. In other embodiments, the invention concerns isolated nucleic acid segments and recombinant vectors incorporating nucleic acid sequences that encode an AChR polypeptide
[0091] The nucleic acid segments used in the present invention, regardless of the length of the coding sequence itself, may be combined with other nucleic acid sequences, such as promoters, polyadenylation signals, additional restriction enzyme sites, multiple cloning sites, other coding segments, and the like, such that their overall length may vary considerably. It is therefore contemplated that a nucleic acid fragment of almost any length may be employed, with the total length preferably being limited by the ease of preparation and use in the intended recombinant nucleic acid protocol. In some cases, a nucleic acid sequence may encode a polypeptide sequence with additional heterologous coding sequences, for example to allow for purification of the polypeptide, transport, secretion, post-translational modification, or for therapeutic benefits such as targeting or efficacy. As discussed above, a tag or other heterologous polypeptide may be added to the modified polypeptide-encoding sequence, wherein “heterologous” refers to a polypeptide that is not the same as the modified polypeptide.
[0092] Numerous expression systems exist that comprise at least a part or all of the compositions discussed above. Prokaryote- and/or eukaryote-based systems can be employed for use with the present invention to produce nucleic acid sequences, or their cognate polypeptides, proteins and peptides. Many such systems are commercially and widely available.
[0093] The insect cell/baculovirus system can produce a high level of protein expression of a heterologous nucleic acid segment, such as described in U.S. Pat. Nos. 5,871,986, 4,879,236, both herein incorporated by reference, and which can be bought, for example, under the name MAXBAC® 2.0 from INVITROGEN® and BACPACK™ BACULOVIRUS EXPRESSION SYSTEM FROM CLONTECH®.
[0094] In addition to the disclosed expression systems of the invention, other examples of expression systems include STRATAGENE®'s COMPLETE CONTROL™ Inducible Mammalian Expression System, which involves a synthetic ecdysone-inducible receptor, or its pET Expression System, an E. coli expression system. Another example of an inducible expression system is available from INVITROGEN®, which carries the T-REX™ (tetracycline-regulated expression) System, an inducible mammalian expression system that uses the full-length CMV promoter. INVITROGEN®also provides a yeast expression system called the Pichia methanolica Expression System, which is designed for high-level production of recombinant proteins in the methylotrophic yeast Pichia methanolica . One of skill in the art would know how to express a vector, such as an expression construct, to produce a nucleic acid sequence or its cognate polypeptide, protein, or peptide.
IV. Kits
[0095] Another embodiment of the invention is a kit comprising a AChR conjugate. Optionally, the kit comprises reagents for detecting or assessing at least a second B cell marker.
[0096] The kit comprises at least one container and a label or package insert on or associated with the container. Suitable containers include, for example, bottles, vials, syringes, etc. The containers may be formed from a variety of materials such as glass or plastic. The container can have a sterile access port for reconstituting and/or extracting an agent (for example the container may be a vial having a stopper pierceable by a hypodermic injection needle). The label or package insert can indicate that the composition is used for assessing or evaluating MG. Additionally, the kit may further comprise a second container comprising a pharmaceutically-acceptable buffer, such as bacteriostatic water, phosphate-buffered saline, Ringer's solution and dextrose solution. It may further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, and syringes.
EXAMPLES
[0097] The following examples are given for the purpose of illustrating various embodiments of the invention and are not meant to limit the present invention in any fashion. One skilled in the art will appreciate readily that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those objects, ends and advantages inherent herein. The present examples, along with the methods described herein are presently representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention. Changes therein and other uses which are encompassed within the spirit of the invention as defined by the scope of the claims will occur to those skilled in the art.
Example 1
Conjugation of Alexa Fluor 488 or 647 to AChR
[0098] AChR was purified from Torpedo Californica electric organs (Aqautic Research Consultants, CA) according to published methods (Wu et al., 1997)—AChR polypeptides include the polypeptides described in GenBank accession numbers AAR29363, AAR29362, AAR29361, AAA96705, AAA49276, AAA49275, AAA492774, including the corresponding human homologs, each of which is incorporated herein by reference in its entirety. Purified AChR protein was run in SDS page and fraction having 2 alpha and one of each beta, gamma, and delta subunits collected are shown in FIG. 1 . Alexa Fluor-AChR conjugates were made by incubating AChR with Alexa Fluor 488 or 647 reactive dye (Invitrogen) which has a succinimidyl ester moiety that reacts efficiently with primary amines of proteins. AChR was concentrated by centrifugation with CentriconYM (10,000 molecular weight) centrifugal filters (Millipore, Mass.). AChR was then dialyzed in PBS using Spectra/Por dialysis tubing (12-14,000 molecular weight). AChR concentration was determined by the Bio-Rad Protein assay using BSA to generate a standard curve for known protein concentration. AChR was then diluted to 2 mg/ml using PBS. Fifty microliters of 1M sodium bicarbonate (pH 8.3) was added to 500 μl of AChR. Next, AChR was added to vial of Alexa fluor reactive dye provided in the Alexa Fluor Protein Labeling Kit. (Invitrogen) and incubated for 1 hr at room temperature (RT) with constant stirring. Labeled AChR was purified according to manufacturers instructions. Concentration of labeled protein was determined as described previously.
Example 2
Testing the Frequency of AChR Specific B Cells in Experimental Autoimmune Myasthenia Gravis
[0099] To identify AChR-specific B cells, C57BL6 mice (Jackson Lab) were immunized with AChR to induce experimental autoimmune myasthenia gravis (EAMG) (Wu et al., 1997). Mice were sacrificed four weeks post-boost immunization and spleen cells were labeled with APC-anti-CD19, PE-anti-CD21/35, and Alexa 488-AChR. First lymphocytes were gated on single cells in suspension (FSC-A vs SSC-A, SSC-H vs SSC-W, and FSC-H vs FSC-W). Then cells were gated on B cells (APC-CD19) and analyzed for binding of PE-CD 21 (a mature B cell marker) and Alexa Flour 488 (FITC-like)-AChR. Mice immunized with AChR in complete Freund's adjuvant (CFA) had more than double the amount of mature AChR+ B cells (CD19+CD21+AChR+) than unimmunized naïve mice or CFA immunized mice. AChR in CFA immunized mice also had increased frequencies (mean 8.1%) of AChR+ B cells in the lymph node compared to naïve mice (3.8%). Also AChR+ (APC like Alex 647-AChR) binding B cells are consistently elevated weeks post immunization and the size of a majority of these cells are large (FSC-A), indicating that these cells are activated.
[0100] Alexa-AChR binding B cells were depleted and those B cell which are not bound to Alexa-AChR were tested for AChR specific B cell proliferation. Those B cells which did not bind to Alexa-AChR failed to induce AChR specific B cell proliferation.
[0101] These results indicate that it is possible to identify the presence of AChR-specific B cells in lymphocyte populations in vivo in EAMG mice. Now we can directly evaluate AChR-specific B cell activation, migration, survival and function in mice with MG. The Torpedo AChR has around 90% sequence homology with human AChR and human MG patients antibodies significantly cross react with Torpedo AChR. The following protocol can be used to test the frequency of Alexa-AChR specific B cells in MG patients.
[0102] Collection of Blood and Identification of AChR Binding B Cell Subsets:
[0103] 1. Collect blood in K2EDTA 10 ml BD Vacutainer Tubes (BD-366643, BD Biosciences). Collect 3 tubes per patient.
[0104] 2. Be sure to invert tube several times after blood has been collected.
[0105] 3. Centrifuge blood tubes for 15 min at 500 g at room temperature (RT).
[0106] 4. Remove plasma.
[0107] 5. Transfer plasma free blood to 50 ml conical tube and add equal volume of RT PBS and mix well.
[0108] 6. Layer blood over equal volume of Histopaque 1077 (10771-100 ml, Sigma-Aldrich).
[0109] 7. Centrifuge without break at 800 g for 20 min at RT.
[0110] 8. Remove lymphocyte layer and place in 15 ml conical tube. Wash with 10 ml RT PBS. Centrifuge at 300 g for 8 min at RT.
[0111] 9. Repeat wash.
[0112] 10. Resuspend cells in FACS Buffer (PBS, 2% FBS, 0.1% sodium azide) at 2×10 7 cells/ml.
[0113] 11. Block cells by incubating with human IgG (1 μg/10 6 cells) for 20 min on ice. (I-4506, Sigma Aldrich).
[0114] 12. Aliquot 100 μl of cells into 5 ml polystyrene round bottom tubes. Add 100 of fluorescent antibody (CD19, CD21) or fluorescent Alexa-AChR diluted in FACS Buffer (1 μg/10 6 cells).
[0115] Table 3 provides the antibody for staining to test the frequency of AChR specific B cells which are naïve/activated, memory, or plasma cells.
[0000]
TABLE 3
Naïve/Activated
Memory
Plasma
APC
AChR
AChR
AChR
FITC
CD27
CD27
IgG
PE
CD43
CD138
CD27
PE-CY7
CD19
CD19
CD38
[0116] Steps include:
[0117] 1. Incubate with the above antibodies for 45 min at 4 degree C. in dark.
[0118] 2. Add 2 ml of RT BD Pharm Lyse Buffer (555899), mix well, and incubate for 15 min at RT in dark.
[0119] 3. Centrifuge for 5 min at 200 g. Discard Buffer.
[0120] 4. Add 2 ml wash buffer, vortex, and centrifuge for 5 min at 200 g.
[0121] 5. Repeat wash.
[0122] 6. Resuspend 300 μl of 2% formaldehyde and store at 4° C.
[0123] 7. Analyze using BD FACS-Canto.
[0124] The methods and compositions represented by these example can be used as follows: (1) For testing the frequency acetylcholine receptor specific B cells using Alexa-AChR conjugate for myasthenia gravis (MG) diagnosis, including those MG patients who are not diagnosed with the conventional sera anti-AChR antibody assay by RIA or ELISA. The Alexa-AChR conjugate could be further used as a rapid biomarker for disease activity and testing the frequency of pathogenic B cell population during treatment of specific drugs in MG patients. (2) Flow cytometry using Alexa-AChR will provide more information about the type of cells producing anti-AChR antibodies, such as antibody class, frequency of these specific B cells, and type of B cells. Anti-AChR antibody secreting B cells (CD38 hi CD20 − CD27 hi CD21 lo ), naive B cells (CD19+ CD27 − CD21 hi CD38 lo ), and memory B cells (CD19+CD38 + CD138+CD27 + ) and possibly plasma cells can be detected. (3) Conjugation of human AChR or human AChR subunits (alpha, beta, epsilon, delta) or its extra cellular domain with Alexa to test the frequency of human AChR or its subunit specific B cells in MG and correlating with disease activity. (4) Use of Alexa-AChR or subunits of various species to test the frequency of AChR or subunit specific B cells during various stages of development in various animal models of MG and MG.
[0125] To identify AChR-specific B cells, mice were immunized with AChR to induce experimental autoimmune myasthenia gravis (EAMG) according to published methods (Wu et al., 1997). Mice were sacrificed four weeks post boost immunization with AChR in complete Freund's adjuvant. For control CFA immunized C57BL6 mice were used. Spleen cells, lymph node cells and blood mononuclear cells were labeled with APC-CD19, PE-CD21/35, and Alexa-488 AChR. First lymphocytes were gated on single cell suspension (FSC-A vs SSC-A, SSC-H vs SSC-W, and FSC-H vs FSC-W). Then cells were gated on B cells (APC-CD19+) and analyzed for binding of PE-CD21 (a mature B cell marker) and Alexa-488 (FITC-like) AChR. Splenocytes of mice immunized with AChR in CFA had more than double the amount of mature AChR+ B cells (CD19+CD21+AChR+) than unimmunized naïve mice and CFA immunized mice ( FIG. 2 ). AChR in CFA immunized mice also had increased frequencies of AChR+ B cells in the lymph node compared to naïve mice. FIG. 3 shows AChR+ (APC) binding B cells (FITC-CD19+) frequencies in pooled lymph nodes in three separate mice with EAMG. AChR+ (APC like Alex 647-AChR) binding B cells are consistently elevated weeks post immunization and the size of a majority of these cells are large (FSC-A) indicating that these cells are activated ( FIG. 3 ). In an independent experiment, Table 3 summarizes the mean percent CD19+ B cells which are AChR+ with SEM and N.
[0000]
TABLE 3
Percent of B cells that were AChR+
in lymph node and spleen by flow cytometry
Lymph Node
Spleen
Mean
SEM
N
Mean
SEM
N
Naïve (pooled)
5.6
0
1
6.4
0
1
CFA + AChR
10.38
.61
7
11.36
1.5
7
[0126] To determine if B cells that bind AChR are specific for autoreactive immune responses in EAMG, B220+AChR− B cells were isolated from spleens of mice immunized with AChR in CFA. Next the inventors stimulated sorted B220+AChR− (AChR+B cell depleted), total B220+ B cells from AChR in CFA immunized mice, and naïve mice in vitro with 1 μg/ml AChR ( FIG. 4 ). AChR+B cell depleted cells had significantly reduced AChR-specific proliferation responses compared to total B220+ cells from EAMG mice. These results indicate that AChR binding B cells are specific for AChR.
[0127] There are many challenges identifying rare AChR-specific B cells. These results demonstrate that it is possible to identify the presence of AChR-specific B cells in lymphocyte populations. The frequency in total lymphocytes in EAMG animals is about 200 AChR+/100,000. Even for in vitro stimulation of purified AChR+B cells a minimum of 160 million B cells per animal would need to be sorted. However, two rounds of sorting would be required to achieve greater than 95% purity of AChR+ B cells. These results indicate that it is possible to characterize AChR-specific B cells in vivo.
Example 3
The Frequency of Acetylcholine Receptor-Specific B Cells Correlates with Experimental Myasthenia Gravis Severity
[0128] Detection by flow cytometry of AChR-binding B cells among PBMCs of mice with EAM.G. Given the pathological significance of complement activation in MG, the inventors conducted a comparative flow cytometry study of AChR-binding B cells which express IgM or IgG2 in mice (Christadoss, 1988). To activate AChR-specific B lymphocytes, mice were immunized multiple times with AChR in CFA. The protocol was optimized by using whole blood drawn from mice with EAMG approximately 2 weeks post the third immunization with AChR emulsified in CFA; these results were then compared to those in naïve or LPS-immunized controls. Alexa fluor 647-AChR was used as a probe for potentially autoreactive AChR-specific B cells, while staining with Alexa fluor 647-OVA was used as a negative control. Shown in FIG. 5 is the typical staining patterns observed from blood stained with Alexa fluor-AChR, anti-B220, anti-IgM, and anti-IgG2. Alexa fluor-AChR preferentially bound to B220-expressing cells, which indicated to us that B cells are the main subset of peripheral lymphocytes capable of binding AChR ( FIG. 5A ). Furthermore, B220+ AChR-binding lymphocytes are most prominent in mice with EAMG. There is no significant increase in B220+ OVA-binding lymphocytes in mice with EAMG. These data suggest that the expansion of B220+ lymphocytes in mice with EAMG is specific to AChR-binding cells. To characterize these cells further, lymphocytes from the upper quadrants (B220+) were gated on and evaluated for expression of IgM or IgG2 and AChR-binding ( FIGS. 1B and 1C ). Although all mice had B220+IgM+ AChR-binding cells, these cells appeared at the highest frequencies in mice with EAMG ( FIG. 5B ). Conversely, only mice with EAMG had elevated frequencies of B220+IgG2+ AChR-binding cells ( FIG. 5C ). Background staining of blood lymphocytes with Alexa-OVA provided results showing the AChR-binding B cells are responsible for the increase in B cell frequencies. To confirm the specificity of this assay, inhibition of Alexa fluor 647-AChR binding to B cells was shown by incubating the cells with a 10-fold excess of unlabeled AChR prior to fluorescent labeling ( FIG. 6 ). Alexa fluor-AChR staining of total B220+ cells, and IgM+ and IgG2+ B cells was significantly reduced by inhibition with unlabeled AChR.
[0129] To determine the significance of the differences observed for AChR-binding B cell frequencies between mice with EAMG and controls, AChR-binding B cell frequency were evaluated at different time points following immunization with AChR in CFA. ( FIG. 7 ). Using the analysis scheme described in FIG. 5 , no significant differences in AChR-binding B cell frequencies were found at a week following the primary AChR immunization. After the second AChR immunization, the frequencies of AChR-binding peripheral blood B cells began to rise. Both B220+IgG2+ and B220+IgM+ AChR-binding B cell frequencies were significantly elevated compared to healthy and LPS immunized mice. After the third immunization, all subsets (B220+, B220+IgM+, B220+IgG2+) of AChR-binding B cells analyzed were significantly elevated compared to findings with subsets in healthy naïve or LPS immunized mice ( FIG. 7 ).
[0130] The appearance and frequency of peripheral blood AChR-specific B cells correlates with the severity of EAMG. Although the presence of serum antibodies to AChR indicates a possible diagnosis of MG, anti-AChR Ig concentrations are not reliable markers for disease severity (Christadoss et al., 1985; Krolick et al., 1994; Drachman et al., 1982). Clinical parameters of EAMG severity were used to determine whether the frequencies of peripheral blood AChR-specific B cells correlate with disease severity. The clinical grade of EAMG is a combination of several observed parameters of EAMG, such as posture, mobility, and muscle strength. Healthy unimmunized mice were assigned a clinical score of 0. A score of 1 is associated with no signs of EAMG prior to exercise or mild disease, a 2 indicates overall moderate symptoms of limb weakness, a score of 3 is associated with significant signs of muscle weakness without exercise and severe disease. After mice were immunized three times (day 75) with AChR in CFA, the frequencies of peripheral blood AChR-specific IgM+ and IgG2+ B cells were compared with the clinical grade of disease ( FIG. 8 ). Earlier time points (days 7, 28, 42) were not evaluated due to the lack of animals with severe disease. IgM+ AChR-specific B cells in blood had a significant correlation with the clinical grade of EAMG (r=0.6638, p<0.0001, n=5-7 per grade) ( FIG. 8A ). IgG2 b+ AChR-specific B cells in blood also had a strong correlation with clinical grade (r=0.767, p<0.0001, n=5-7 per grade) ( FIG. 8C ).
[0131] Grip strength ratios are a more objective measurement of loss of muscle strength, described in detail in methods. A grip strength ratio>1 indicates an increase in strength over time, while a grip strength ratio≦1 indicates a loss of grip strength overtime. Mice which developed severe EAMG would have grip strength ratios≦1. IgM+ AChR binding B cells in blood had a no significant correlation (r=−0.1688, p=0.3978, n=26) with grip strength ratio ( FIG. 8B ). However, IgG2 b+ AChR-binding B cells in blood had a negative correlation (r=−0.459, p<0.016, n=26) with the grip strength ratio ( FIG. 8D ). Taken together, these results indicate that increased frequencies of peripheral blood AChR-specific B cells correspond to loss of limb muscle strength (grip strength ratio<1) and to higher clinical grades of disease. Furthermore, AChR-specific IgG2 expressing B cells is a good biomarker of disease severity.
[0132] Plasma secreted anti AChR Igs do not correlate with the AChR-specific B cell frequencies in mice with EAMG. It has been previously demonstrated that sera or plasma anti-AChR Igs titers alone is not a reliable predictor of disease severity (Christadoss et al., 1985; Kroick et al., 1994; Lefvert et al., 1978). However, this new assay demonstrated that the frequencies of AChR-specific B cells is useful biomarker for disease severity. The association between AChR-specific B-cell frequencies and plasma anti-AChR concentrations was also evaluated ( FIG. 9 ). Mice were immunized with CFA and AChR and bled at days 7, 28, 42, and 56. Plasma was separated from cells by centrifugation and analyzed for secreted anti-AChR Igs. Blood was then stained for AChR-binding B cells. Overall, the concentrations of anti-AChR Igs and frequencies of AChR-specific B cells tended to increase throughout the induction phase of EAMG ( FIGS. 9A and 9C ). However, at a time when animals have no disease symptoms (day 28), plasma anti-AChR IgG2 titers are significantly elevated. After boost immunization (day 42), mice began to show signs of disease, while plasma anti-AChR IgG2 titers started to decrease, the AChR-specific, IgG2-expressing B cells first began to appear in the peripheral blood. No significant correlation was found between individual mouse plasma anti-AChR level and specific peripheral B cell populations ( FIGS. 9B and 9D ).
[0133] MG patients have higher frequency of AChR binding B cells. Peripheral blood from MG patients positive for anti-AChR or anti-MUSK antibody or healthy control were tested for their CD19+B cell binding to AChR by flow cytometry. Anti-AChR antibody positive MG patients, but not anti-MUSK+patients or healthy controls had higher frequency of B cells binding to AChR ( FIG. 10 ).
Materials and Methods
[0134] Mice and induction of EAMG. C57BL/6 mice were purchased from the Jackson Laboratories (Bar Harbor, Me., USA). AChR extracted from Torpedo californica or from murine muscle tissue was purified on a neurotoxin affinity column, as previously described (Wu et al., 2001). EAMG was induced by emulsifying 100 μl CFA with 100 μl AChR (20 μg) in PBS. A separate group of mice were immunized with 100 μl of LPS (5 mg) emulsified in incomplete Freund's adjuvant for comparison. Both groups were anesthetized, and then immunized (200 μl/animal) with multiple s.c. injections in shoulders and foot pads. Mice were immunized 3 times, 28 days apart. All animals were housed in a barrier facility at the University of Texas Medical Branch and maintained according to the Institutional Animal Care and Use Committee guidelines.
[0135] Clinical Evaluation of EAMG. Evaluation of disease severity and muscle weakness was performed immediately prior to blood draw and at 2 weeks after each immunization and measured as follows: Grade 0, normal mobility, posture and grip strength; Grade 1, hunchback posture, restricted mobility and decreased muscle grip strength after paw grip exercises; Grade 2, without exercise, observed hunchback posture, restricted mobility and decreased muscle grip strength; Grade 3, dehydrated and moribund with grade 2 weakness, death, or euthanasia due to paralysis. Mice were exercised by 30 paw grips on the cage top grid. Following exercise, and grip strength was measured by a dynamometer (Chatillon Digital Force Gauge, DFIS. 2, Columbus Instruments, Columbus, Ohio). The grip strength ratio for each mouse at each time point was determined by dividing the average grip strength post immunization by the average grip strength prior to immunization. A grip strength ratio>1 indicates an increase in strength over time, while a grip strength ratio≦1 indicates a loss of grip strength overtime.
[0136] Conjugation of Alexa Fluor 647 to AChR. AChR was purified from torpedo californica electric organs (Aquatic Research Consultants, CA) according to published methods (Wu et al., 2001). AChR was concentrated by centrifugation with CentriconYM (10,000 molecular weight) centrifugal filters (Millipore, Mass.). AChR was then dialyzed in PBS by using Spectra/Por dialysis tubing (12-14,000 molecular weight). AChR was labeled with Alexa Fluor 647 Protein Labeling Kit (Invitrogen) according to the manufacturer's instructions.
[0137] Blood collection, Flow Cytometry, and ELISA Blood was collected from the tail vein into K 2 EDTA microtubes at 7 days after primary immunization and at 2 weeks following the 2 nd and 3 rd immunization. In keeping with previously published ELISA protocols, blood was centrifuged at 500 g for 15 min, and plasma removed for analysis of secreted anti-AChR-Igs (Yang et al., 2005). Blood was then treated with BD Pharm Lyse Buffer. Fcγ receptors were blocked with anti-CD16/32 Ab (Ab 93, eBioscience). Fifty μl of whole blood was stained for surface markers with Alexa fluor 647-AChR or Alexa fluor 647-Ovalbumin (Ova) and PE-Cy7-anti B220 (RA3-6B2), then fixed and permeabilized by using a Cytoperm/Cytofix kit (BD Biosciences) according to standard protocols for flow cytometry. Cells were then stained with anti-IgG2 b (R12-3) and anti-IgM (eB121-15F9) Abs or isotype controls. Cell populations were determined using a BD FACS Canto and FlowJo v 7.2 (Tree Star).
[0138] Statistics. Cell phenotype was analyzed using an ANOVA with a two-tail p value. Correlation of cell frequencies to clinical grade, grip strength ratio, and plasma secreted anti-AChR Igs were determined by a Spearman correlation with a two-tail p value. The linear regression model was used to fit data.
REFERENCES
[0139] The following references, to the extent that they provide exemplary procedural or other details supplementary to those set forth herein, are specifically incorporated herein by reference.
U.S. Pat. No. 4,554,101 U.S. Pat. No. 4,879,236 U.S. Pat. No. 5,871,986 A Practical Approach, Athert on & Sheppard (Eds.), IRL Press, Oxford, England, 1989. Aharonov et al., Lancet., 2(7930):340-2, 1975. Balass et al., Proc. Natl. Acad. Sci. USA, 90(22):10638-10642, 1993. Barany and Merrifield, In: The Peptides , Gross and Meienhofer (Eds.), Academic Press, NY, 1-284, 1979. Bartfeld and Fuchs, Proc. Natl. Acad. Sci . USA, 75(8):4006-4010, 1978. Beeson et al., EMBO J., 9(7):2101-2106, 1990. Brinkley, Bioconjugate Chem ., 3(1):2-13, 1992. Changeux et al., Science, 225(4668):1335-1345, 1984. Chemical Approaches to the Synthesis of Peptides and Proteins, Williams et al. (Eds.), CRC Press, Boca Raton Fla., 1997. Christadoss et al., J. Neuroimmunol., 8:29-41, 1985. Christadoss, J. Immunol ., 140:2589-2592, 1988. Creighton, Proteins; Structures and Molecular Principles, W. H. Freeman and Co., NY, 1983 De Leon-Rodriguez et al., Chem. Eur. J., 10:1149-1155, 2004. Drachman et al., N. Engl. J. Med., 307:769-775, 1982. Drachman, N. Engl. J. Med ., 330(25):1797-1810, 1994. Garman, In: Non - Radioactive Labelling: A Practical Approach , Academic Press, London, 1997. Gene Expression Technology, Method in Enzymology, Genetics and Molecular Biology, Method in Enzymology, Guthrie & Fink (Eds.), Academic Press, San Diego, Calif., 1991. Glazer et al., In: Chemical Modification of Proteins . Laboratory Techniques in Biochemistry and Molecular Biology, Work and Work (Eds.), American Elsevier Pub. Co., NY, 1975. Haugland, In: Molecular Probes Handbook of Fluorescent Probes and Research Chemicals , Molecular Probes, Inc., 2003. Hitzeman et al., J. Bio. Chem., 255:12073-12080, 1990. Karlin, J. Theor. Biol ., 87(1):33-54, 1980. Krolick et al., Adv. Neuroimmunol., 4:475-493, 1994. Kyte and Doolittle, J. Mol. Biol ., 157(1):105-132, 1982. Lefvert et al., J. Neurol. Neurosurg. Psychiatry, 41:394-403, 1978. Lewis et al., Bioconjugate Chem., 12:320-324, 2001. Li et al., Bioconjugate Chem., 13:110-115, 2002. Loutrari et al., Eur. J. Immunol., 22(9):2449-2452, 1992. Lundblad and Noyes, In: Chemical Reagents for Protein Modification , Vols. I and II, CRC Press, NY, 1984. Maniatis, et al., Molecular Cloning , A Laboratory Manual, Cold Spring Harbor Press, Cold Spring Harbor, N.Y., 1982. Means and Feeney, Bioconjugate Chem ., 1(1):2-12, 1990. Merrifield, Science , 232(4748):341-347, 1986. Mier et al., Bioconjugate Chem., 16:240-237, 2005. Noda et al., Nature, 305(5937):818-823, 1983. Patrick and Lindstrom, Science , 180:871-872, 1973. Pfleiderer, In: Chemical Modification of Proteins , Modern Methods in Protein Chemistry, Tschesche (Ed.), Walter DeGryter, Berlin and NY, 1985. Sambrook et al., Molecular Cloning : A Laboratory Manual, Cold Spring Harbor Press, NY, 2nd Ed., 1998 Sambrook et al., Molecular Cloning : A Laboratory Manual, Cold Spring Harbor Press, NY, 3 rd Ed., 2000. Schoepfer et al., FEES Lett., 226(2):235-240, 1988. Shenoy et al., Clin. Immunol. Immunopathol., 66(3):230-238, 1993. Souroujon et al., Ann. NY Acad. Sci., 681:332-334, 1993. Souroujon et al., Immunol. Lett., 34(1):19-25, 1992. Stewart and Young, In: Solid Phase Peptide Synthesis , 2d. ed., Pierce Chemical Co., 1984. Structures and Molecular Principles, W. H. Freeman and Co., NY, 1983. Tam et al., J. Am. Chem. Soc., 105:6442, 1983. Tzartos and Lindstrom, Proc. Natl. Acad. Sci. USA , 77(2):755-759, 1980. Tzartos et al., Neuroimmunol., 15(2):185-194, 1987. Wong, Chemistry of Protein Conjugation and Cross - Linking , CRC Press, Boca Raton, Fla., 1991. Wu et al., Curr. Protoc. Immunol., 15:Unit 15-18, 2001. Wu, et al., In: Experimental Autoimmune Myasthenia Gravis in the Mouse. Current Protocols in Immunology . John Wiley & Sons, Inc, Chap. 15.8, 1997.
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Disclosed are methods, compositions, and diagnostic kits for detecting acetylcholine receptor (AchR) autoreactive immune cells in a subject. The methods comprise detecting the binding of AChR-conjugate to penpheral blood AChR-specific B cells for diagnosing autoimmune disorders, including Myasthenia gravis (MG), systemic lupus erythematous (SLE), and rheumatoid arthritis (RA). More specifically, the detection is achieved by using flow cytometric assay with Alexa-conjugated AchR.
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BACKGROUND OF THE INVENTION
1. Technical Field:
This invention relates to parking aid devices that are activated by the vehicle as it parks in a garage. The devices provide a visual or audio warning to the driver indicating that the vehicle is properly positioned.
2. Description of Prior Art:
Prior Art devices of this type have used a variety of different activation and signaling mechanisms to indicate the vehicles relative position, see for example U.S. Pat. Nos. 3,820,065, 4,145,681 and 4,318,077.
In U.S. Pat. No. 3,820,065 a parking aid is disclosed that uses a light bulb activated by spring urged feeler that extends from the device mounted on the front wall of the garage. A battery provides power energizing the light upon movement of the feeler activating the circuit.
U.S. Pat. No. 4,145,681 shows a parking guide signaling device for cars having an enclosure with a lightbulb and reflector with an extending activation lever. As the vehicle approaches it moves a lever activating the warning light.
In U.S. Pat. No. 4,318,077 a vehicle parking aid and signaling device is disclosed having a light source that is activated by the closing of a switch. A deformable member is engaged by the vehicle inflating an elastic bulb within the d evice closing the switch activating the warning circuitry and associated light source.
SUMMARY OF THE INVENTION
A self-contained electronic vehicle parking device that signals the vehicle's driver the relative position of the vehicle within the parking garage. The device comprises a power source interconnected to a pre-programmed electronic circuit that allows for single or multiple activation by a self-contained floor mounted pressure switch. The device indicates initial postion of the vehicle and warns of continued advancement of the vehicle.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphic representation of a vehicle approaching a garage wall and the parking device;
FIG. 2 is a schematic diagram of the eletronic circuit used in the device;
FIG. 3 is a tire position diagram indicating approach, activation and deactivation of a portion of the device;
FIG. 4 is a tire posititoning diagram showing an alternate form of the invention; and
FIG. 5 is a top plan view of a representation of a vehicle and garage with the device positioned within.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 of the drawings a vehicle parking device is disclosed for use in a parking garage 10 having a front wall 11 and an oppositely disposed side walls 12 and 13. A vehicle V is illustrated in FIGS. 1 and 5 of the drawings approaching the front wall 11. The vehicle parking device is comprised of an enclosure having a control and signaling unit 14 and a remote activation switch 15 interconnected therewith. The control and signaling unit 14 is best seen in FIG. 2 of the drawing having an electrical circuit 16 interconnected to a signal lamp 17 and a battery power source 18. A edge-triggered one-shot multivibrator 19 interconnects the above referred to components and is provided with power from the battery power source 18 at Vcc and c respectively. The switch 15 is of the low profile tpe and is positioned on a floor 20 of the garage 10, best seen in FIGS. 1 and 5 of the drawings. The switch 15 is connected to the battery power source 18 and the ultivibrator 19 at T. The signaling lamp 17 is connected to the battery power source 18 and a terminal Q of the multivibrator 19. It will be evident from the above description that activation of the switch 15 closes the power circuit and activates the multivibrator 19 applying power activating (in this embodiment) the signal lamp 17.
A predetermined delay within the multivibrator 19 will then remove power deactivating the lamp 17. This condition is illustrated in FIG. 3 of the drawings wherein a vehicle's tire 21 shown in solid lines is engaged on the switch 15. The set delay chosen in this example is 15 seconds which is sufficient time for the driver to stop the vehicle V in a predetermined safe distance from the wall 11. Should the vehicle V tire 21 move away and off the switch 15 as seen in FIG. 3 in broken lines at 22 before the expiration of the predetermined time then the power to the signal device 17 via the output Q would be turned off deactivating the signal lamp indicating to the vehicle V operator that the vehicle has travelled too far and is in immediate danger of impacting into the garage wall 11.
Only after the vehicle's V tire 21 disengages the switch 15 does the circuit reset to a wait further activation as seen in FIG. 3 by the positioning of the tire 22 in broken lines.
Referring now to FIGS. 2 and 4 of the drawings an alternate form of the invention is shown wherein a secondary switch 23 is disclosed in broken lines interconnected to the power battery source circuit directly so that upon activation by engagement of a tire 24 (shown in broken lines) the signal lamp 17 will be activated. The continuous non-timed activation of the signal lamp 17 by the secondary switch 23 warns the vehicle's operator to stop and back up the vehicle prior to impact with the wall. The operator can reposition the vehicle so that the tire 24 will rest as shown in solid lines in FIG. 4 of the drawings.
Thus, it will be seen that a new and useful vehicle parking indicator has been illustrated and described and that it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention, therefore I claim:
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A self contained electronic vehicle parking device that indicates the relative position of a vehicle in a garage to the operator. A multiple timing circuit is provided to preset indicator activation time and reset the circuit for the next use.
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This is a division of application Ser. No. 175,974, filed Aug. 7, 1980, now U.S. Pat. No. 4,363,201.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates in general to panel joints, and more specifically to panel joints for joining two upstanding panel members tightly together with their front surfaces disposed in a common plane.
2. Description of the Prior Art
In certain applications, wall panel members are required to be joined together to form a room or cubicle, with the joining hardware concealed. When the width of a wall exceeds a predetermined dimension, it is constructed of two or more in-line panels. The joints between the in-line panels must be tight, and they must remain tight during usage. The front surfaces of the in-line panels must be disposed in a common plane, and the composite wall must be flat without any bowing at the joint. Wall panels formed of wood or other non-metal panels, are relatively thick and heavy, and their surfaces may not be perfectly flat. The weight and non-flatness add to the problem of assembling panels with tight joints. Further, certain types of panels may vary slightly in thickness from panel to panel, which creates a very difficult joining problem as the slightest deviation in panel thickness is noticeable when two panels are joined in-line with concealed hardware.
It would thus be desirable to provide new and improved panel joints for relatively large, heavy panels which enable the panels to be quickly and tightly joined in-line with the desired orientation of the front panel surfaces in a common plane. It would further be desirable to remove or reduce any bow or out-of-flatness condition of the panel members, especially at the critical joint area, without increasing assembly time. Still further, it would be desirable to provide a new and improved panel joint which will quickly enable the assembler to compensate for a difference in thickness of the panels to be joined.
SUMMARY OF THE INVENTION
Briefly, the present invention includes new and improved panel joints for joining relatively thick wall panel members, such as wood, or other non-metallic materials, in-line with concealed hardware. The joints are quickly and easily formed by an assembler located adjacent to the front sides of the panels.
In a first embodiment, a new and improved joint is disclosed for use when the panel thickness dimensions will be substantially uniform from panel to panel. Metallic alignment plates and spacer members are fixed to the back surfaces of first and second wall panel members adjacent to the edges to be butted together, and the panel members are shipped to the job site, along with a single metallic joining member. The assembler positions the first and second wall panel members, such that the alignment plates, which extend outwardly from their associated panel towards the other panel, contact the rear surface of the other panel. The joining member has first and second columns of elongated openings or slots which engage the spacer members on the first and second panel members. The assembler then pounds the metallic joiner member vertically downward, which forces the joining member tightly against the alignment plates to remove any bow or waviness in the panels, and it forces the two adjoining edges tightly together by virtue of slots in one of the vertical columns which are angled or inclined slightly from the vertical.
In a second embodiment, a new and improved joint is disclosed for use when the panel thickness dimension may vary from panel to panel. Spacer members are fixed to the rear surfaces of first and second panel members, adjacent to the edges to be butted together. A metallic joining member is provided which has first and second portions or elements, which elements are clamped together to enable the joining member to function as a single member. Elongated slots are provided in each of the first and second elements. In a preferred embodiment, the spacers are fixed to one of the panel members through the elongated slots in one of the elements to slideably fix the joining member thereto for shipment. At the job site, the assembler places the first and second wall panels in position adjacent to one another and raises the joining member to allow the spacer members on the other panel to enter and be captured by the slots. The assembler then pounds the joining member vertically downward, to pull the adjacent edges tightly together. If the front surfaces of the two panels are in different planes due to the panels having slightly different thickness dimensions, the joining member is released by pounding it upwardly. The clamping means is loosened to permit the relative positions of the two elements of the joining member to be adjusted according to the variation in panel thickness. The clamping means is retightened and the panels are then reassembled.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be better understood, and further advantages and uses thereof more readily apparent when considered in view of the following detailed description of exemplary embodiments, taken with the accompanying drawings in which:
FIG. 1 is a front elevational view of first and second upstanding wall panel members joined with a panel joint constructed according to a first embodiment of the invention;
FIG. 2 is an end elevational view of the upstanding wall panel members shown in FIG. 1;
FIG. 3 is a plan view of the upstanding wall panel members show in FIG. 1;
FIG. 4 is a fragmentary, perspective view illustrating elements of the joint shown in FIGS. 1-3, and a step in the assembly of the joint;
FIG. 5 is a view similar to that of FIG. 4, illustrating the next assembly step;
FIG. 6 is a view similar to that of FIG. 5, illustrating the joining member in its downwardly forced frictional locking position;
FIG. 7 is a fragmentary, perspective view of joint elements constructed according to another embodiment of the invention; and
FIG. 8 is a view similar to that of FIG. 7, illustrating the complete joint, with the joining member disposed in its downwardly displaced frictional locking position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is an elevational view of a panel joint 10 constructed according to the teachings of the invention, with FIG. 2 being an end view of joint 10, and FIG. 3, a plan view. Joint 10 is especially suitable for joining wall panel members which have a uniform thickness dimension from panel to panel, but which may have a slight bow or waviness when viewed from an edge. Non-flat panels joined in-line with concealed hardware make an unattractive joint, if the panel surfaces are not aligned along the entire length of the joint. The joint of the present invention forces such alignment.
More specifically, panel joint 10 is an in-line joint, as opposed to an angular joint, with joint 10 joining first and second upstanding wall panel members 12 and 14. Wall panel members 12 and 14 are relatively large and heavy panels, formed of a material such as wood, or a wood substitute. Panel members 12 and 14 form a wall, or a portion of a wall, such as a wall for a cubicle which may be used as the cab for an elevator car. Wall panel member 12 has front and rear major flat surfaces 16 and 18, respectively, top and bottom edges 20 and 22, respectively, and first and second vertically extending side edges 24 and 26, respectively, with the second side edge 26 also being referred to as an "adjacent" edge, because it is the edge to be butted against wall panel member 14. Wall panel member 14 has first and second major flat surfaces 28 and 30, respectively, top and bottom edges 32 and 34, respectively, and first and second vertically extending side edges 36 and 38, respectively, with the first side edge 36 also being referred to as an "adjacent" edge. Joint 10 joins wall panel members 12 and 14 in-line with their front surfaces 16 and 28 aligned in a common vertical plane.
Joint 10 includes a plurality of metallic alignment plates 40 and 40' fixed in vertically spaced staggered relation to the rear surfaces 18 and 30, respectively, of the first and second wall panel members 12 and 14. The metallic alignment plates are fixed to the adjacent edges 26 and 36, with a portion of each alignment plate extending outwardly past the adjacent edge of the panel member it is fixed to, such that it overlaps and contacts the rear surface of the other panel member. Alignment plates 40 and 40' alternate with one another such that there is no interference between them. Alignment plates 40 and 40' are preferably grouped to provide a plurality of pairs 42, with each pair 42 including an alignment plate 40 fixed to panel member 12, and an alignment plate 40' fixed to panel member 14. The alignment plates of each pair 42 are closely spaced, with a larger spacing between adjacent pairs.
FIG. 4 is a perspective view of the uppermost pair 42 of alignment plates 40 and 40' as they would appear during a step in the formation of joint 10 shown in FIGS. 1, 2, and 3. FIG. 4 more clearly illustrates an exemplary construction of an alignment plate. Since alignment plates 40 and 40' may be of like construction, only alignment plate 40 will be described in detail. Alignment plate 40 is formed from a metallic plate or sheet, such as 0.188 inch thick steel. Alignment plate 40 has a generally elongated rectangular configuration which has a length dimension of about 6 inches, and a width dimension of about 2 inches. Plate 40 has first and second major flat opposed surfaces 44 and 46, respectively, with a plurality of holes formed therein which are countersunk on side 46. Imaginary center line 48 divides plate 40 into first and second halves 50 and 52, respectively, with the plurality of openings or holes being formed in the first half 50. Flat head screws 54 secure each alignment plate 40 to the rear surface 18 of the first wall panel member 12, with care being taken to ensure that the surface of each flat head screw 44 does not extend outwardly past the second major surface 46 of alignment plate 40.
Joint 10 additionally includes a plurality of spacer members 60 and 60' fixed in vertically spaced relation to the rear surfaces 18 and 30, respectively, of the first and second wall panel members 12 and 14, along their adjacent edges 26 and 36, respectively. In a preferred embodiment, spacer members 60 and 60' are located at like vertical positions, with spacer member 60 preferably being located between panel edge 26 and an imaginary vertical line 61 which interconnects the left hand edges of alignment plates 40, as viewed in FIG. 4. In like manner, spacer member 60' is preferably located between panel edge 36 and an imaginary vertical line 63 which interconnects the right hand edges of alignment plates 40'.
Since spacer members 60 and 60' may be of like construction, only spacer member 60 will be described in detail. More specifically, spacer member 60 is a metallic member which includes a smooth, round shank portion 62 having a predetermined diameter, such as about 0.5 inch, and a length dimension in the direction of the longitudinal axis 64 which is slightly greater, i.e., about 0.005 inch greater, than the thickness dimension of the alignment plates 40 plus the thickness dimension of a metallic joining member to be hereinafter described. Spacer member 60 further includes a smooth round head portion 66 having a predetermined diameter which is larger than the diameter of shank portion 62, such as about 0.75 inch, and a length dimension of about 0.125 inch. Instead of the shank 62 and head 66 joining at right angles relative to one another such that the underside of the head forms a flange, an angled or tapered cam surface 68 is provided between shank 62 and head 66. Cam surface 68 defines a predetermined angle with shank 62, such as an angle of about 25°. The longitudinal length of cam surface 68, i.e., measured along the longitudinal axis 64 of spacer member 60, is about 0.25 inch.
Spacer member 60 is secured to the back surface 18 of panel member 12 via suitable fastener means. As illustrated, spacer member 60 may have an opening coaxial with its longitudinal axis 64 for receiving a screw 70. A pilot opening may be pre-drilled in panel member 18 to accurately locate and guide screw 64. Spacer members 60 are attached to the back surface 18 of wall panel member 12 with the centers of the spacer members all being located on a common vertical imaginary line spaced a predetermined dimension from the adjacent edge of the wall panel member.
Joint 10 is completed by a joining member 80, best shown in FIG. 6. FIG. 6 is a fragmentary, perspective view of joint 10, after the completion thereof. Joining member 80 is formed from an elongated metallic plate member 82, such as a steel plate, having first and second major opposed flat surfaces 84 and 86, respectively. Plate member 82 further includes upper and lower ends, with reference to the view shown in FIG. 6, such as upper end 88, and a longitudinal axis or center line 90 which extends between its ends. Plate member 82 also has first and second side edges 92 and 94, respectively. As illustrated, plate member 82 may be bent adjacent to side edges 92 and 94 to provide leg portions 96 and 98 which extend vertically outward from major side or surface 86. Leg portions 96 and 98 function to stiffen the elongated joining member 80, and may be omitted if plate member 82 is formed from steel plate which has the required mechanical characteristics without additional stiffening. A metallic block member (not shown) may be welded adjacent to the upper end of the metallic joining member, for use in hammering the joining member 80 into, or out of, its frictional locking position to be hereinafter described. The length dimension of joining member 80 is selected such that the joining member will not extend below the bottom edges of the panel members, after the joining member 80 is disposed in its locking position.
A plurality of first elongated slots or openings 100 are provided on one side of longitudinal center line 90, and a plurality of second elongated slots or openings 102 are provided on the other side of center line 90. The longitudinal axes of the first slots 100 are vertically oriented, and the longitudinal axes of the second slots 102 are inclined such that the upper end 104 of each slot 102 is closer to the longitudinal center line 90 than the lower end 106 of the slot.
The longitudinal axes of the first slots 100 are all located on imaginary line 108, which is parallel to and spaced from the longitudinal center line 90. The second elongated slots 102 have centers which are all located on an imaginary line 110 which is parallel to and spaced from longitudinal center line 90. Unlike slots 100, however, the longitudinal axes 112 of slots 102 are not vertically oriented, but they are slightly inclined, such as by an angle of about 4° from the vertical line 110.
Slots 100 and 102 each have an enlarged first portion at its lower end, a second portion which has parallel sides, which starts at its upper end, and a third portion in the form of a tapered transition which extends between the enlarged first portion and the second portion. For example, slot 102 has an enlarged first portion 114 at its lower end 106, a second portion 116 starting at its upper end 104, which portion has parallel sides, and a tapered intermediate transition or third portion 118 which starts at the enlarged first portion 114 and tapers inwardly to the second portion 116. Enlarged portion 114 is constructed such that its lower end is in the form of a half circle, with the transition 118 extending from the ends of the half circle to the second portion 116. The diameter of the half circle is selected such that the head portion of the spacer member 60' will extend therethrough without interference.
Referring again to FIG. 4, the first step in forming joint 10 is illustrated. The assembler uprights the panel members 12 and 14 in approximately the position they will assume when they are assembled. For ease in positioning the alignment plates 40 and 40' properly, panel members 12 and 14 may initially be angled slightly such that they provide an angle slightly less than 180°, with the assembler being located on this side of the angle. When the adjoining edges 26 and 36 are just about touching, the assembler straightens the panels to cause the angle to swing to 180°, which will bring the alignment plates 40 and 40' against the rear surfaces 30 and 18, respectively, of the panel members, as shown in FIG. 5. Joining member 80 is then placed in position such that the spacer members 60 and 60' enter the enlarged portions of the elongated slots 100 and 102, respectively, and are captured thereby. The assembler then strikes the top edge of the joining member 80, or the special block provided for this purpose, with a hammer, forcing the joining member 80 into a downwardly displaced frictional locking position, as shown in FIG. 6.
As joining member 80 is forced vertically downward, the tapered transitions of slots 100 and 102 make it easy to capture the spacer members 40 and 40' in the slots, even when the panel members are bowed. Continued downward movement of joining member 80 results in the narrowing taper of transition 118 camming the joining member 80 into tight engagement with the alignment plates 40 and 40'. Joining member 80, being straight and flat, cams tightly against the alignment plates, forcing the alignment plates 40 and 40' into a common plane. Since surfaces 44 of the alignment plates, and thus the rear surfaces 18 and 30 of the panel members are all in a common plane, especially in the joint area, their front surfaces 16 and 28 are forced into a common plane at the joint area, with no mismatch or step. Continued downward movement of joining member 80 to its final locking position causes the adjoining edges of the panel members 12 and 14 to be drawn tightly together due to the inclined slots 102 acting upon the spacer members 60' to move wall panel member 14 tightly against wall panel member 16.
In the embodiment of the invention shown in FIGS. 1-6, the thickness dimensions of the wall panel members were assumed to be substantially uniform from panel to panel, such that when the rear surfaces of the panel members are straightened and aligned in a common plane by the alignment plates and joining member, the front surfaces will also be automatically aligned in a common plane. Certain types of wall panel members, however, may have a slight variation in panel thickness dimension from panel to panel. FIGS. 7 and 8 are fragmentary, perspective views of a panel joint 120 constructed according to another embodiment of the invention, which may be used to align the front surfaces of two in-line panel members in a common plane, notwithstanding a difference in their thickness dimensions. In general, the major differences between this embodiment of the invention and the embodiment of FIGS. 1-6 is the elimination of the alignment plates 40 and 40', and the dividing of the joining member 80 into first and second parts or elements along the longitudinal centerline 90. The first and second parts or elements of the joining member are adjustably clamped after the elements are adjusted relative to one another to accommodate the specific thickness dimensions of the wall panel members to be butted together and joined. Components in FIGS. 7 and 8 which may be the same as those in FIGS. 1-6 will be given like reference numerals, and will not be described again in detail.
More specifically, joint 120 includes a joining member 80' having first and second separate portions 82' and 82" with each portion having a substantially U-shaped cross-sectional configuration wherein portion 82' includes spaced leg portions 96' and 122, and a flat connecting bight portion 124. Portion 82" includes spaced leg portions 124 and 94', and a flat connecting bight portion 126. Leg portions 122 and 124 have aligned openings therein when the side surfaces of these leg portions are butted together, with additional aligned openings being vertically spaced at predetermined intervals. One of the openings of the aligned pairs is horizontally elongated, such as the horizontally elongated slot or opening 128 shown in leg portion 122. Suitable adjustable clamping or fastener means 130 link the two portions via the aligned openings, such as a nut 132, bolt 134, and lock washer 136.
The elongated slots in the flat bight portions of the two elements of the joining member 80' may be the same as in the embodiment set forth in FIGS. 1-6; or, as illustrated in FIG. 7, slot 100 may be modified to provide a slot 100' which has no enlarged portion and no tapered transition. The fact that this embodiment of the invention does not utilize the alignment plates of the first embodiment makes it possible to assemble the joining member 80' with panel member 16 at the factory, and thus one of the panel members and joining member 80' may be shipped as a unit. This has the advantage in that all elements of the joint are fixed to the panel members for shipment, precluding the loss of any of the essential joint elements.
If the slots in both joint elements are identical to those in the embodiment of FIGS. 1-6, the spacer members would also be the same as in the first embodiment. However, if the modified slots 100' are used, then a spacer member 140 would be used, instead of spacer member 60. Spacer member 140 includes a shank and head portion, but it does not have the tapered transition of spacer member 60. Spacer members 140 are inserted through slot 100' and then fastened to the rear of wall panel member 12, to capture joining member 80' but with sufficient clearance to allow it to move in a snug but slideable relation.
As illustrated in FIG. 7, joining member 80' is shipped to the job site with the first and second portions being initially set to join two panel members having the same thickness dimension. If it is found by the assembler in the field that panel member 14 is not as thick as panel member 12, or it is thicker than panel member 12, the assembler loosens the plurality of fastener means and adjusts the relative positions of the first and second portions or elements 82' and 82" to accommodate the difference in thickness. The fastener means is then retightened. This adjustment step may be accomplished with, or without panel member 14 connected to panel member 12, depending upon the easiest approach considering the space available to the assembler. Similar to the first embodiment, when joining means 80' is hammered downwardly to its frictional locking position, panel 14 will be cammed tightly against joining member 80' due to the taper or cam on the spacers 60' and the tapered portion of the slots 102, and the adjacent edges of the wall panel members 12 and 14 will be drawn tightly together due to the inclined slots 102 and spacer members 60'.
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Mid-wall panel joints for joining first and second upstanding wall panel members tightly together with their front surfaces in a common plane. A first embodiment utilizes a combination of spacer members and alignment plates fixed to the rear surfaces of the wall panel members, and an elongated joining member which has first and second columns of elongated slots. The spacer members on the first and second wall panel members extend through spacer head receiving portions of the elongated slots and the joining member is then downwardly advanced to a frictional locking position. A second embodiment utilizes spacer members and a split or divided elongated joining member, adjustably clamped together, which permits alignment of the front surfaces of the wall panel members in a common plane, notwithstanding the joining of wall panel members having different thickness dimensions.
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FIELD OF THE INVENTION
This invention relates to compositions and treated polymer fabrics.
BACKGROUND OF THE INVENTION
Polymer fabrics are extensively used in a wide variety of products, ranging from disposable towel sheets to sanitary napkins and from disposable diapers to surgical sponges. All these applications involve the absorption of water or aqueous liquids (urine, blood, lymph, spills of coffee, tea, milk, etc.). The fabrics must have good wicking properties, i.e., water must be readily taken up and spread.
Polymer fabrics are generally hydrophobic. It is desirable to improve the wicking/wetting ability of the polymer fabrics. Often wetting agents are used to improve the ability of the polymer fabric to pass water and bodily fluids through the polymer fabric and into an absorbent layer. Further, it is desirable that the polymer fabric maintain its wicking/wetting characteristics after repeated exposure to water or aqueous liquids.
SUMMARY OF THE INVENTION
This invention relates to a composition comprising: (i) at least one ester-acid, ester-salt or mixtures thereof and (ii) at least one amidic-acid, amidic-salt or mixtures thereof. These compositions are useful in treating polymer fabrics. The treated polymer fabrics have improved wicking/wetting characteristics. The treated polymer fabrics maintain these characteristics upon repeated exposure to aqueous fluids.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The term "hydrocarbyl" includes hydrocarbon, as well as substantially hydrocarbon, groups. Substantially hydrocarbon describes groups which contain non-hydrocarbon substituents which do not alter the predominately hydrocarbon nature of the group.
Examples of hydrocarbyl groups include the following:
(1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, aromatic-substituted aliphatic substitutents or aromatic-substituted alicyclic substituents, or, aliphatic- and alicyclic-substituted aromatic substituents and the like as well as cyclic substituents wherein the ring is completed through another portion of the molecule (that is, for example, any two indicated substituents may together form an alicyclic radical);
(2) substituted hydrocarbon substituents, that is, those substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominantly hydrocarbon substituent; those skilled in the art will be aware of such groups (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylthio, nitro, nitroso, sulfoxy, etc.);
(3) hetero substituents, that is, substituents which will, while having a predominantly hydrocarbon character within the context of this invention, contain other than carbon present in a ring or chain otherwise composed of carbon atoms. Suitable heteroatoms will be apparent to those of ordinary skill in the art and include, for example, sulfur, oxygen, nitrogen and such substituents as, e.g., pyridyl, furyl, thienyl, imidazolyl, etc. In general, no more than about 2, preferably no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group. Typically, there will be no such non-hydrocarbon substituents in the hydrocarbyl group. In one embodiment, the hydrocarbyl group is purely hydrocarbon.
(A) Polymer Fabrics
The polymer fabrics which are treated in accordance with this invention may be any polymer fabric, preferably a woven or nonwoven fabric, more preferably a nonwoven fabric. The polymer fabric may be prepared by any method known to those skilled in the art. When the fabric is nonwoven, it may be a spunbonded or melt-blown polymer fabric, preferably a spunbonded fabric. Spinbonding and melt-blowing processes are known to those in the art.
The polymer fabric may be prepared from any thermoplastic polymer. The thermoplastic polymer can be a polyester, polyamide, polyurethane, polyacrylic, polyolefin, combinations thereof, and the like. The preferred material is polyolefin.
The polyolefins are polymers which are essentially hydrocarbon in nature. They are generally prepared from unsaturated hydrocarbon monomers. However, the polyolefin may include other monomers provided the polyolefin retains its hydrocarbon nature. Examples of other monomers include vinyl chloride, vinyl acetate, methacrylic or acrylic acids or esters, acrylamides and acrylonitriles. Preferably, the polyolefins are hydrocarbon polymers. The polyolefins include homopolymers, copolymers and polymer blends.
Copolymers can be random or block copolymers of two or more olefins. Polymer blends can utilize two or more polyolefins or one or more polyolefins and one or more nonpolyolefin polymers. As a practical matter, homopolymers and copolymers and polymer blends involving only polyolefins are preferred, with homopolymers being most preferred.
Examples of polyolefins include polyethylene, polystyrene, polypropylene, poly(1-butene), poly(2-butene), poly(1-pentene),poly(2-pentene), poly(3-methyl-1-pentene), poly(4-methyl-1-pentene), poly-1,3-butadiene and polyisoprene or these hydrogenated analogs, more preferably polyethylene and polypropylene.
(B) The Mixtures
The polymer fabric is treated with at least one mixture comprising (i) an ester-acid, ester-salt or mixtures thereof, and (ii) an amidic-acid, amidic-salt or mixtures thereof to improve the hydrophilic character of the fabric. The treated polymer fabrics have improved wetting and wicking properties. The ester-acid has at least one ester group and at least one acid group while the ester-salt has at least one ester group and one salt group. The amidic-acid has an amide group and an acid group while the amidic-salt has an amide group and a salt group. The ester-acid, ester-salt and mixtures thereof are prepared by reacting a polycarboxylic acylating agent with a polyhydroxy compound. The polycarboxylic acylating agent may be an acid, anhydride, ester or acid chloride. The amidic-acid, amidic-salt or mixtures thereof is prepared by reacting a polycarboxylic acylating agent with an amine selected from secondary alkyl amines, amine-terminated polyoxyalkylenes, and tertiary alkyl primary amines under amide forming conditions
The polycarboxylic acylating agents include di- and tricarboxylic acylating agents. Polycarboxylic acylating agents include dimer acid acylating agents, hydrocarbyl-substituted succinic acylating agents, Alder acylating agents, and trimer acid acylating agents, preferably hydrocarbyl-substituted succinic acylating agents.
The dimer acylating agents are the products resulting from the dimerization of unsaturated fatty acids. Generally, the dimer acylating agents have an average from about 18, preferably about 28 to about 44, preferably to about 40 carbon atoms. In one embodiment, the dimer acylating agents have preferably about 36 carbon atoms. The dimer acylating agents are preferably prepared from fatty acids. Fatty acids generally contain from 8, preferably about 10, more preferably about 12 to 30, preferably to about 24 carbon atoms. Examples of fatty acids include oleic, linoleic, linolenic, tall oil and rosin acids, preferably oleic acid. e.g., the above-described fatty acids. The dimer acylating agents are described in U.S. Pat. Nos. 2,482,760; 2,482,761; 2,731,481; 2,793,219; 2,964,545; 2,978,463; 3,157,681 and 3,256,304, the entire disclosures of which are incorporated herein by reference. Examples of dimer acylating agents include Empol® 1041, 1016 and 1018 Dimer Acid, each available from Emery Industries, Inc. and Hystrene® dimer acids 3675, 3680, 3687 and 3695, available from Humko Chemical.
In another embodiment, the polycarboxylic acylating agents are dicarboxylic acylating agents which are prepared by reacting an unsaturated fatty acid (e.g., the above-described fatty acids, preferably tall oil acids or oleic acids) with alpha, beta-ethylenically unsaturated carboxylic acylating agent (e.g., acrylic or methacrylic acylating agents). This reaction is known as the "Ene" reaction or the Alder reaction. The acylating agents made by this reaction are referred to herein as Alder acylating agents. In U.S. Pat. No. 2,444,328, the disclosure of which is incorporated herein by reference. These Alder acylating agents include Westvaco® Diacid H-240, 1525 and 1550, each being commercially available from the Westvaco Corporation.
In a preferred embodiment the polycarboxylic acylating agents are hydrocarbyl-substituted succinic agents. The hydrocarbyl group has from about 8, preferably about 10, more preferably about 12 to about 150, more preferably to about 100, more preferably to about 50 carbon atoms. In one embodiment, the hydrocarbyl group contains from about 8, preferably about 10, more preferably about 12 to about 30, preferably to about 24, more preferably to about 18 carbon atoms. Preferably, the hydrocarbyl group is an alkyl group, an alkenyl group, a group derived from a polyalkene or mixtures thereof, more preferably an alkyl or alkenyl group. In one embodiment, the hydrocarbyl group may be an octyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, octenyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl, oleyl, tallow, soya or tetrapropenyl group.
In one embodiment the hydrocarbyl group is derived from olefins having from about 2 to about 30 carbon atoms or oligomers thereof. These olefins are preferably alpha-olefins (sometimes referred to as mono-1-olefins) or isomerized alpha-olefins. Examples of the alpha-olefins include 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 1-henicosene, 1-docosene, 1-tetraconsene, etc. Commercially available alpha-olefin fractions that can be used include the C 15-18 alpha-olefins, C 12-16 alpha-olefins, C 14-16 alpha-olefins, C 14-18 alpha-olefins, C 16-18 alpha-olefins, C 16-20 alpha-olefins, C 22-28 alpha-olefins, etc. The C 12 and C 16-18 alpha-olefins are particularly preferred.
Isomerized alpha-olefins may also be used to form Alder reaction products. These olefins are alpha-olefins that have been converted to internal olefins. The isomerized alpha-olefins suitable for use herein are usually in the form of mixtures of internal olefins with some alpha-olefins present. The procedures for isomerizing alpha-olefins are well known to those in the art. Briefly these procedures involve contacting alpha-olefins with a cation exchange resin at a temperature in a range of about 80° to about 130° C. until the desired degree of isomerization is achieved. These procedures are described for example in U.S. Pat. No. 4,108,889 which is incorporated herein by reference.
The hydrocarbyl group may also be derived from an oligomer of one or more of the above olefins. The oligomers are generally prepared from olefins having less than 7 carbon atoms, preferably ethylene, propylene or butylene, more preferably propylene. When the hydrocarbyl group is derived from an oligomer, the oligomer usually has from about 8 to about 30 carbon atoms. A preferred oligomer group has 12 carbon atoms and is a propylene tetramer. The hydrocarbyl group may be derived from mixtures of monoolefins.
When the hydrocarbyl group on the carboxylic acylating agent is derived from a polyalkene, the polyalkene has a number average molecular weight (Mn) from about 400, preferably about 700, more preferably about 800 to about 1500, preferably about 1200. The polyalkene is a homopolymer or an interpolymer of polymerizable olefin monomers of 2 to about 16 carbon atoms, preferably 2 to about 6 carbon atoms, more preferably 3 to 4 carbon atoms. The interpolymers are those in which 2 or more olefin monomers are interpolymerized according to well known conventional procedures to form polyalkenes. The monoolefins are preferably ethylene, propylene, butylene, or octylene with butylene preferred. A preferred polyalkene group is a polybutenyl group. Polyalkene groups and succinic acylating agents derived therefrom are disclosed in U.S. Pat. Nos. 3,215,707 (Rense); 3,219,666 (Norman et al); 3,231,587 (Rense); 4,110,349 (Cohen); and 4,234,435 (Meinhardt et al). These patents are incorporated by reference for its disclosure of polyalkene groups, succinic acylating agents as well as procedures for making either of the same.
The succinic acylating agents are prepared by reacting the above-described olefins or isomerized olefins with unsaturated carboxylic acids such as fumaric acids or maleic acid or anhydride at a temperature of about 160° to about 240° C., preferably about 185° to about 210° C. Free radical inhibitors (e.g., t-butyl catechol) may be used to reduce or prevent the formation of polymeric byproducts. The procedures for preparing the acylating agents are well known to those skilled in the art and have been described for example in U.S. Pat. No. 3,412,111; and Ben et al, "The Ene Reaction of Maleic Anhydride With Alkenes", J.C.S. Perkin II (1977), pages 535-537. These references are incorporated by reference for their disclosure of procedures for making the above acylating agents.
The polycarboxylic acylating agent may also be a tricarboxylic acylating agent. Examples of tricarboxylic acylating agents include trimer acid and Alder tricarboxylic acylating agents. These acylating agents generally contain an average from about 18, preferably about 30, more from about 36 to about 66, preferably to about 60 carbon atoms. Trimer acylating agents are prepared by the trimerization of the above-described fatty acids. The Alder tricarboxylic acylating agents are prepared by reacting an unsaturated monocarboxylic acid with alpha, beta-ethylenically unsaturated dicarboxylic acid (e.g., fumaric acid or maleic acid or anhydride). In one embodiment, the Alder acylating agent contains an average from about 12, preferably about 18 to about 40, preferably to about 30 carbon atoms. Examples of these tricarboxylic acylating agents include Empol® 1040 available commercially from Emery Industries, Hystrene® 5460 available commercially from Humko Chemical, and Unidyme® 60 available commercially from Union Camp Corporation.
In one embodiment, polyalkene substituted carboxylic acids may be used in combination with the fatty alkyl or alkenyl substituted carboxylic acids. The fatty alkyl or alkenyl groups are those having from about 8 to about 30 carbon atoms. It is preferred that the polyalkene substituted carboxylic acids and the fatty substituted carboxylic acids are used in mixtures of an equivalent ratio of from about (0-1.5:1), more preferably about (0.5-1:1), more preferably about (1:1).
The above polycarboxylic acylating agents are reacted with a hydroxy compound to form the ester-acids of the present invention. The hydroxy compounds may be polyhydric alcohols, hydroxyamines and hydroxy-containing polyoxyalkylene compounds. The hydroxy compounds include aliphatic or alkylenepolyols, polyoxyalkylene polyols, alkyl-terminated polyoxyalkylene polyols, polyoxyalkylene amines, polyoxyalkylated phenols, polyoxyalkylated fatty acids, polyoxyalkylated fatty amides, and alkanolamines.
In one embodiment, the hydroxy compounds include polyhydric alcohols, such as alkylene polyols. Preferably, these polyhydric alcohols contain from 2 to about 40, more preferably to about 20 carbon atoms; and from 2 to about 10, more preferably to about 6 hydroxyl groups. Polyhydric alcohols include ethylene glycols, including di- and triethylene glycol; propylene glycols, including di- and tripropylene glycol; glycerol; butanediol; hexanediol; sorbitol; arabitol; mannitol; sucrose; fructose; glucose; cyclohexanediol; trimethylolpropane erythritol; and pentaerythritols, including di- and tripentaerythritols; preferably diethylene glycol, triethylene glycol; glycerol, trimethyolpropane, sorbitol, pentaerythritol, and dipentaerythritol.
The polyhydric alcohols may be esterified with monocarboxylic acids having from 2 to about 30 carbon atoms, provided at least one hydroxyl group remains unesterified. Examples of monocarboxylic acids include acetic, propionic, butyric and the above-described fatty carboxylic acids, as well as saturated fatty acids, such as stearic, lauric and palmitic acids. Specific examples of these esterified polyhydric alcohols include sorbitol oleate, including mono- and oleates, sorbitol stearates including mono- and distearates, glycerol oleates, including glycerol mono-, di- and trioleate, and erythritol octanoates.
The hydroxy compounds may also be polyoxyalkylene polyols. The polyoxyalkylene polyols include polyoxyalkylene glycols. The polyoxyalkylene glycols may be polyoxyethylene glycols or polyoxypropylene glycols. Useful polyoxyethylene glycols are available from Union Carbide under the trade name Carbowax® PEG 300, 600, 1000 and 1450. The polyoxyalkylene glycols are preferably polyoxypropylene glycols where the oxypropylene units are at least 80% of the total. The remaining 20% may be ethylene oxide or butylene oxide. Useful polyoxypropylene glycols are available from Union Carbide under the trade name NIAX 425; and NIAX 1025. Useful polyoxypropylene glycols are available from Dow Chemical and sold by the trade name PPG-1200, and PPG-2000.
Representative of other useful polyoxyalkylene polyols are the liquid polyols available from Wyandotte Chemicals Company under the name PLURONIC Polyols and other similar polyols. These PLURONIC Polyols correspond to the formula ##STR1## wherein x, y, and z are integers greater than 1 such that the --CH 2 CH 2 O-groups comprise from about 10% to about 15% by weight of the total molecular weight of the glycol, the average molecular weight of said polyols being from about 2500 to about 4500. This type of polyol can be prepared by reacting propylene glycol with propylene oxide and then with ethylene oxide.
In another embodiment the hydroxy-compound is an alkyl-terminated polyoxyalkylene polyol. A variety of alkyl-terminated polyoxyalkylene polyols are known in the art, and many are available commercially. The alkyl-terminated alkylene polyols are produced generally by treating an aliphatic alcohol with an excess of an alkylene oxide such as ethylene oxide or propylene oxide. For example, from about 6 to about 40 moles of ethylene oxide or propylene oxide may be condensed with the aliphatic alcohol, such as methanol, ethanol, butanol, or fatty alcohols (i.e., those containing 8 to about 30 carbon atoms).
The alkyl-terminated polyoxyalkylene polyols useful in the present invention are available commercially under such trade names as "TRITON®" from Rohm & Haas Company, "Carbowax®" and "TERGITOL®" from Union Carbide, "ALFONIC®" from Conoco Chemicals Company, and "NEODOL®" from Shell Chemical Company. The TRITON® materials are identified generally as polyethoxylated alcohols or phenols. The TERGITOLS® are identified as polyethylene glycol ethers of primary or secondary alcohols; the ALFONIC® materials are identified as ethoxylated linear alcohols which may be represented by the general structural formula
CH.sub.3 (CH.sub.2).sub.d CH.sub.2 (OCH.sub.2 CH.sub.2).sub.c OH
wherein d varies between 4 and 16 and e is a number between about 3 and 11. Specific examples of ALFONIC® ethoxylates characterized by the above formula include ALFONIC® 1012-60 wherein d is about 8 to 10 and e is an average of about 5 to 6; ALFONIC® 1214-70 wherein d is about 10-12 and e is an average of about 10 to about 11; ALFONIC® 1412-60 wherein d is from 10-12 and e is an average of about 7; and ALFONIC® 1218-70 wherein d is about 10-16 and e is an average of about 10 to about 11.
The Carbowax® methoxy polyethylene glycols are linear ethoxylated polymer of methanol. Examples of these materials include Carbowax® methoxy polyethylene glycol 350, 550 and 750, wherein the numerical value approximates molecular weight.
The NEODOL® ethoxylates are ethoxylated alcohols wherein the alcohols are a mixture of alcohols containing from 12 to about 15 carbon atoms, and the alcohols are partially branched chain primary alcohols. The ethoxylates are obtained by reacting the alcohols with an excess of ethylene oxide such as from about 3 to about 12 or more moles of ethylene oxide per mole of alcohol. For example, NEODOL® ethoxylate 23-6.5 is a partially branched chain alcoholate of 12 to 13 carbon atoms with an average of about 6 to about 7 ethoxy units.
In another embodiment, the hydroxy compound is a hydroxyamine. The hydroxyamine may be an alkanolamine or a polyoxyalkylated amine. The hydroxyamine may be primary, secondary or tertiary alkanol amines or mixtures thereof. Such amines may be represented by the formulae: ##STR2## wherein each R is independently a hydrocarbyl group of one to about eight carbon atoms or hydroxyhydrocarbyl group of two to about eight carbon atoms and R' is a divalent hydrocarbyl group of about two to about 18 carbon atoms. The group --R'--OH in such formulae represents the hydroxyhydrocarbyl group. R' can be an acyclic, alicyclic or aromatic group. Typically, R' is an acyclic straight or branched alkylene group such as an ethylene, 1,2-propylene, 1,2-butylene, or 1,2-octadecylene group, more preferably an ethylene or propylene group, more preferably an ethylene group. Where two R groups are present in the same molecule they can be joined by a direct carbon-to-carbon bond or through a heteroatom (e.g., oxygen, nitrogen or sulfur) to form a 5-, 6-, 7- or 8-membered ring structure. Examples of such heterocyclic amines include N-(hydroxyl lower alkyl)-morpholines, -thiomorpholines, -piperazines, -piperidines, -oxazolidines, -thiazolidines and the like. Typically, however, each R is independently a methyl, ethyl, propyl, butyl, pentyl, or hexyl group. Examples of alkanolamines include monoethanol amine, diethanol amine, triethanol amine, diethylethanol amine, ethylethanol amine, butyldiethanol amine, etc.
The hydroxyamines can also be an ether N-(hydroxyhydrocarbyl)amine. These are hydroxypoly(hydrocarbyloxy) analogs of the above-described alkanolamines (these analogs also include hydroxyl-substituted oxyalkylene analogs). Such N-(hydroxyhydrocarbyl) amines can be conveniently prepared by reaction of epoxides with afore-described amines and can be represented by the formulae: ##STR3## wherein g is a number from about 2 to about 15 and R and R' are as described above. R may also be a hydroxypoly(hydrocarbyloxy) group.
In another embodiment, the hydroxy compound is a hydroxyamine, which can be represented by the formula ##STR4## wherein each R' is described above, R" is a hydrocarbyl group; each a is independently an integer from zero to 100, provided at least one a is an integer greater than zero; and b is zero or one.
Preferably, R" is a hydrocarbyl group having from 8 to about 30 carbon atoms, preferably 8 to about 24, more preferably 10 to about 18 carbon atoms. R" is preferably an alkyl or alkenyl group, more preferably an alkenyl group. R" is preferably an octyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, oleyl, soya or tallow group.
a is preferably 1 to about 100, more preferably 2 to about 50, more preferably 2 to about 20, more preferably 3 to about 10, more preferably about 5.
The above hydroxyamines can be prepared by techniques well known in the art, and many such hydroxyamines are commercially available. They may be prepared, for example, by reaction of primary amines containing at least 6 carbon atoms with various amounts of alkylene oxides such as ethylene oxide, propylene oxide, etc. The primary amines may be single amines or mixtures of amines such as obtained by the hydrolysis of fatty oils such as tallow oils, sperm oils, coconut oils, etc. Specific examples of fatty acid amines containing from about 8 to about 30 carbon atoms include saturated as well as unsaturated aliphatic amines such as octyl amine, decyl amine, lauryl amine, stearyl amine, oleyl amine, myristyl amine, palmityl amine, dodecyl amine, and octadecyl amine.
The useful hydroxyamines where b in the above formula is zero include 2-hydroxyethylhexylamine, 2-hydroxyethyloctylamine, 2-hydroxyethylpentadecylamine, 2-hydroxyethyloleylamine, 2-hydroxyethylsoyamine, bis(2-hydroxyethyl)hexylamine, bis(2-hydroxyethyl)oleylamine, and mixtures thereof. Also included are the comparable members wherein in the above formula at least one a is an integer greater than 2, as for example, 2-hydroxyethoxyethylhexylamine.
A number of hydroxyamines wherein b is zero are available from the Armak Chemical Division of Akzona, Inc., Chicago, Ill., under the general trade designation "Ethomeen" and "Propomeen". Specific examples of such products include "Ethomeen C/15" which is an ethylene oxide condensate of a cocoamine containing about 5 moles of ethylene oxide; "Ethomeen C/20" and "C/25" which also are ethylene oxide condensation products from cocoamine containing about 10 and 15 moles of ethylene oxide respectively; "Ethomeen O/12" which is an ethylene oxide condensation product of oleylamine containing about 2 moles of ethylene oxide per mole of amine. "Ethomeen S/15" and "S/20" which are ethylene oxide condensation products with soyaamine containing about 5 and 10 moles of ethylene oxide per mole of amine respectively; and "Ethomeen T/12, T/15" and "T/25" which are ethylene oxide condensation products of tallowamine containing about 2, 5 and 15 moles of ethylene oxide per mole of amine respectively. "Propomeen O/12" is the condensation product of one mole of oleyl amine with 2 moles propylene oxide. Preferably, the salt is formed from Ethomeen C/15 or S/15 or mixtures thereof.
Commercially available examples of hydroxyamines where b is 1 include "Ethoduomeen T/13", "T/20" and "T/25" which are ethylene oxide condensation products of N-tallow trimethylene diamine containing 3, 10 and 15 moles of ethylene oxide per mole of diamine, respectively.
Another group of hydroxyamines above are the commercially available liquid TETRONIC polyols sold by Wyandotte Chemicals Corporation. These polyols are represented by the general formula: ##STR5## wherein h and j are such that h is a number sufficient to provide a number average molecular weight of about 3000 to about 12000, preferably to about 6000, and j is a number sufficient to provide a number average molecular weight of about 25 to about 85. Examples of these alcohols include Tetronic® 701, 901, 1501, 90R1, and 150R1 polyols. Such hydroxyamines are described in U.S. Pat. No. 2,979,528 which is incorporated herein by reference. A specific example would be such a hydroxyamine having an average molecular weight of about 8000 wherein the ethyleneoxy groups account for 7.5%-12% by weight of the total molecular weight. Such hydroxyamines can be prepared by reacting an alkylenediamine such as ethylene diamine, propylenediamine, hexamethylenediamine, etc., with propylene oxide. Then the resulting product is reacted with ethylene oxide.
In another embodiment, the hydroxy compound may be a propoxylated hydrazine. Propoxylated hydrazines are available commercially under the tradename Oxypruf™, Examples of propoxylated hydrazines include Oxypruf™ 6, 12 and 20 which are hydrazine treated with 6, 12 and 20 moles of propylene oxide, respectively.
In another embodiment, the hydroxy compound may be a polyoxyalkylated phenol. The phenol may be substituted or unsubstituted. A preferred polyoxyalkylated phenol is a polyoxyethylated nonylphenol. Polyoxyalkylated phenols are available commercially from Rohn and Haas Co. under the tradename Triton® and Texaco Chemical Company under the tradename Surfonic®. Examples of polyoxyalkylated phenols include Triton® AG-98, N series, and X series polyoxyethylated nonylphenols.
In another embodiment, the hydroxy compound may be a polyoxyalkylene fatty ester. Polyoxyalkylene fatty esters may be prepared from any polyoxyalkylene polyol and a fatty acid. Preferably, the polyoxyalkylene polyol is any disclosed herein. The fatty acid is preferably one of the fatty monocarboxylic acid described above. Polyoxyalkylene fatty esters are available commercially from Armak Company under the tradename Ethofat™. Specific examples of polyoxyalkylene fatty esters include Ethofat™ C/15 and C/25, which are coco fatty esters formed using 5 and 15 moles, respectively, of ethylene oxide; Ethofat™ O/15 and O/20, which are oleic esters formed using 5 and 10 moles of ethylene oxide; and Ethofat 60/15, 60/20 and 60/25 which are stearic esters formed with 5, 10 and 15 moles of ethylene oxide respectively.
In another embodiment, the hydroxy compound may also be a polyoxyalkylated fatty amide. Preferably the fatty amide is polyoxypropylated or polyoxyethylated, more preferably polyoxyethylated. Examples of fatty acids which may be polyoxyalkylated include oleylamide, stearylamide, tallowamide, soyaamide, cocoamide, and laurylamide. Polyoxyalkylated fatty amides are available commercially from Armak Company under the trade name Ethomid® and from Lonza, Inc., under the tradename Unamide®. Specific examples of these polyoxyalkylated fatty amides include Ethomid® HT/15 and HT/60, which are hydrogenated tallow acid amides treated with 5 and 50 moles of ethylene oxide respectively; Ethomid® O/15, which is an oleic amide treated with 5 moles of ethylene oxide; Unamide® C-2 and C-5, which are cocamides treated with 2 and 5 moles of ethylene oxide, respectively; and Unamide® L-2 and L-5, which are lauramides treated with 2 and 5 moles of ethylene oxide, respectively.
The ester-acids of the present invention may be prepared from a hydroxyl-containing compound and a carboxylic acylating agent by conventional esterification techniques. The reaction occurs between about ambient temperature and the decomposition temperature of any of the reactants or the reaction mixture, more preferably about 50° C. to 250° C., more preferably about 70° C. to 175° C. The hydroxyl compound and carboxylic acid or anhydride are reacted at an equivalent ratio from, preferably about (1:1.5-4), more preferably (1:2). When a carboxylic anhydride is used, the ester-acid is formed by a ring opening reaction between the hydroxyl compound and the anhydride.
Salts of the above ester-acids may also be used in the present invention. Salts of the above ester-acids may be ammonium or metal salts. The metal of the metal salt may be an alkali metal, alkaline earth metal or transition metal, preferably an alkali metal, or an alkaline earth metal, more preferably an alkali metal. Specific examples of metal include sodium, potassium, calcium, magnesium, zinc or aluminum, more preferably sodium or potassium. The metal cations are formed by treating an ester-acid with a metal oxide, hydroxide, carbonate, phosphate, sulfate, or halide. The metal salt is formed between ambient temperature and about 120° C., more preferably room temperature to about 80° C.
The ammonium salt may be derived from ammonia or any amine. The ammonium cation may be derived from any of the amines described herein. The ammonium cation may be derived from the hydroxyamine forming the ester, and is therefore an internal salt. Preferably, the salt is formed from alkyl monoamines, or hydroxyamines. The hydroxyamines are described above. Preferably the amine which forms the ester-salt is represented by the formula ##STR6## wherein R', R", a and b are defined above.
The alkyl monoamines are primary secondary or tertiary monoamines. The alkyl monoamines generally contain from to about 24 carbon atoms in each alkyl group, preferably from 1 to about 12, and more preferably from 1 to about 6. Examples of monoamines useful in the present invention include methylamine, ethylamine, propylamine, butylamine, octylamine, and dodecylamine. Examples of secondary amines include dimethylamine, dipropylamine, dibutylamine, N-methyl,N-butylamine, N-ethyl,N-hexylamine, etc. Tertiary amines include trimethylamine, tributylamine, methyldiethylamine, ethyldibutylamine, etc.
In one embodiment, the ester-acid and ester-salt are represented by the formula ##STR7## wherein R 1 is a hydrocarbyl group as defined above for the hydrocarbyl-substituted succinic acylating agent; R 2 is a hydrocarbylene group, or a hydroxy substituted or hydroxyalkyl substituted hydrocarbylene; each R 3 is independently hydrogen, an alkyl group, a hydroxyalkyl group, a hydrocarbylcarbonyl or a polyoxyalkylene group; each R 4 is independently a hydrocarbylene group; each n is independently 1 to 150; q is zero or one; r is zero or one; M is a hydrogen, an ammonium cation or a metal cation, and
when r is zero, X is --H, --OAr, --OH, --OR 5 , ##STR8## when r is one, X is --H, --R 5 , ##STR9## or ##STR10## wherein each R 5 and R 6 is independently a hydrocarbyl group having up to 100 carbon atoms; R 7 is hydrogen or an alkyl group having from 1 to about 8 carbon atoms and Ar is a phenyl or a benzyl group.
Each R 5 and R 6 is independently a hydrocarbyl group having up to about 100 carbon atoms, preferably 2, preferably about 8 to about 50, preferably to about 30, more preferably to about 24. In one embodiment, each R 5 is independently an alkyl or alkenyl group. Generally, R 5 contains from 1 to about 28 carbon atoms, preferably to about 18, more preferably to about 12.
In another embodiment, each R 6 is independently an alkyl or alkenyl group, a polyalkene group, or mixtures thereof. In another embodiment, R 6 is a group defined the same as R 1 .
Ar is a phenyl, naphthyl or benzyl group. The phenyl, naphthyl or benzyl group may be substituted with a hydrocarbyl group or a polyoxyalkylenyl group. The hydrocarbyl group may contain 2 to about 18 carbon atoms, more preferably about 6 to about 12, more preferably about 9. The polyoxyalkylenyl group is preferably a polyoxyethenyl or polyoxypropenyl group.
R 2 is a hydrocarbylene, or a hydroxy substituted or hydroxyalkyl substituted hydrocarbylene. Preferably R 2 is an alkylene group having from 2 to about 8 carbon atoms, more preferably 2 to about 4; or hydroxy substituted or hydroxyalkyl substituted alkylene having from 2 to about 10 carbon atoms, more preferably about 4 to about 6 carbon atoms. When R 2 is an alkylene group, it is preferably an ethylene or propylene group.
Each R 3 is independently hydrogen, an alkyl group, a hydrocarbylcarbonyl group or a polyoxyalkylene group. Preferably each R 3 is independently a hydrogen; an alkyl group having from to about 20 carbon atoms, more preferably 1 to about 8; a hydroxy alkyl group having from 1 to about 8 carbon atoms, more preferably from 1 to about 4; a hydrocarbyl carbonyl group having from 1 to about 28 carbon atoms in the hydrocarbyl group, more preferably about 8 to about 30, more preferably about 8 to about 24; or a polyoxyethylene group, a polyoxypropylene group, or mixtures thereof, more preferably polyoxyethylene group.
In one embodiment each R 3 is independently an alkyl or alkenyl carbonyl group. The alkyl or alkenyl group is preferably a methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, decenyl, dodecenyl, tetradecenyl, hexadecenyl, or octadecenyl group.
In another embodiment, each R 3 is independently an alkyl or alkenyl group. The alkyl or alkenyl group is preferably an ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, oleyl, tallow or soya group.
In another embodiment, each R 3 is independently a hydroxyalkyl group. Preferably the hydroxyalkyl group is a hydroxymethyl or hydroxyethyl group, more preferably hydroxyethyl.
Each R 4 is independently a hydrocarbylene group. Preferably each R 4 is independently an alkylene group having from 1 to about 8, more preferably 2 to about 4 carbon atoms. Preferably, each R 4 is independently ethylene or propylene.
R 7 is hydrogen or an alkyl group having from 1 to about 8 carbon atoms. Preferably R 7 is hydrogen or a methyl, ethyl, propyl, butyl or hexyl group, more preferably hydrogen or methyl group, more preferably hydrogen.
Each n is independently 1 to about 150. Preferably each n is independently 1, more preferably 2, more preferably about 3 to about 50, more preferably to about 20, more preferably to about 10.
In one embodiment, q equals zero or one, r equals zero or one. In one embodiment, r equals zero and X is preferably --OH, --OR 5 , ##STR11## wherein R 1 , R 5 , R 6 , and M are as defined previously.
In another embodiment, r equals one, q equals one and X is preferably ##STR12## wherein R 1 , R 6 , and M are as defined previously.
In another embodiment, r equals zero, n equals one, R 2 is a hydroxy substituted or hydroxyalkyl substituted hydrocarbylene group and X is preferably --OH, ##STR13## wherein R 1 , R 5 , R 6 , and M are as defined previously.
The amidic-acids, and amidic-salts used in the present invention are prepared by the reaction of the above-described polycarboxylic acylating agents with at least one amine selected from the group consisting of a secondary amine, an amine-terminated polyoxyalkylene and a tertiary aliphatic primary amine. The amines are selected so that an amidic acid is formed between the amine and polycarboxylic acid.
In one embodiment, the amine is a secondary amine. The secondary amine is preferably a secondary cycloalkyl or alkyl amine. Each alkyl group independently has from 1, preferably about 3 to about 28, preferably to about 12, more preferably to about 6 carbon atoms. Each cycloalkyl group independently contains from 4 to about 28, preferably to about 12, more preferably to about 8 carbon atoms. Examples of cycloalkyl and alkyl groups include methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl groups. Preferred secondary alkyl amines include but are not limited to dipropyl amine, dibutyl amine, diamyl amine, dicyclohexylamine and dihexylamine.
The amine-terminated polyoxyalkylene and tertiary alkyl primary amine are primary amines which contain a secondary or tertiary carbon atom adjacent to the nitrogen. The substituted carbon atom adjacent to the nitrogen provides stearic hindrance which impedes imide formation.
In one embodiment, the primary amine is a tertiary-alkyl primary amine. In one embodiment, the alkyl group contains from about 4, preferably about 6, more preferably about 8 to about 30, preferably to about 24 carbon atoms. Usually the tertiary alkyl primary amines are monoamines represented by the formula ##STR14## wherein R 8 is a hydrocarbyl group containing from one to about 27 carbon atoms. Such amines are illustrated by tertiary-butyl amine, tertiary-hexyl amine, 1-methyl-1-amino-cyclohexane, tertiary-octyl amine, tertiary-decyl amine, tertiary-dodecyl amine, tertiary-tetradecyl amine, tertiary-hexadecyl amine, tertiary-octadecyl amine, tertiary-tetracosanyl amine, tertiary-octacosanyl amine.
Mixtures of amines are also useful for the purposes of this invention. Illustrative of amine mixtures of this type are "Primene 81R" which is a mixture of C 11 -C 14 tertiary alkyl primary amines and "Primene JMT" which is a similar mixture of C 18 -C 22 tertiary alkyl primary amines (both are available from Rohm and Haas Company). The tertiary alkyl primary amines and methods for their preparation are known to those of ordinary skill in the art. The tertiary alkyl primary amine useful for the purposes of this invention and methods for their preparation are described in U.S. Pat. No. 2,945,749 which is hereby incorporated by reference for its teaching in this regard.
In another embodiment the primary amine is amine-terminated polyoxyalkylene; such as an amino polyoxypropylene-polyoxyethylene-polyoxypropylene, or an amino polyoxypropylene. These amines are generally prepared by the reaction of a monohydric alcohol with an epoxide, such as styrene oxide, 1,2-butene oxide, ethylene oxide, propylene oxide and the like, more preferably ethylene oxide, propylene oxide or mixtures thereof. The terminal hydroxyl group is then converted to an amino group. These amines are represented by the structure: ##STR15## wherein p is 1 to about 150, R 9 is an alkoxy group having 1 to about 18 carbon atoms, and each R 10 is independently hydrogen or an alkyl group. Preferably p is 1 to 100, more preferably about 4 to about 40. Preferably each R 10 is independently hydrogen or an alkyl group having from 1 to 4 carbon atoms, more preferably hydrogen or a methyl group. R 9 is preferably an alkoxy group having from 1 to 12 carbon atoms, more preferably a methoxy group. These types of amines are available from Texaco Chemical Company under the tradename Jeffamine. Specific examples of these amines include Jeffamine® M-600; M-1000, M-2005 and M-2070 amines.
In another embodiment, the amine-terminated polyoxyalkylene is a diamine such as preferably amine terminated polypropylene glycols. These diamines are represented by the formula ##STR16## wherein q is from preferably 2 to about 150, more preferably to about 100, more preferably to about 75. Examples of these amines include Jeffamine® D-230 wherein q is about 2-3;, Jeffamine® D-400 wherein q is about 5-6, Jeffamine® D-2000 wherein q is an average of about 33, and Jeffamine® D-4000 wherein q is an average of about 68.
In another embodiment, the diamines are represented by the formula ##STR17## wherein d is a number in the range of from zero to about 200; e is a number in the range of form about 10 to about 650; and f is a number in the range of from zero to about 200. These diamines preferably have number average molecular weights in the range of about 600 to about 6,000, more preferably about 600 to about 2,000. Specific examples of the diamines include Jeffamine® ED-600 wherein d+f is approximately 2.5 and e is approximately 8.5; Jeffamine® ED-900 wherein d+f is approximately 2.5 and e is approximately 15.5; and Jeffamine® ED-2001 wherein d+f is approximately 2.5 and e is approximately 40.5.
In another embodiment, the diamines are represented by the formula ##STR18## wherein q is a number sufficient to provide said compound with a number average molecular weight of at least about 600. These compounds preferably have number average molecular weights in the range of about 600, more preferably to about 2,500, more preferably to about 2,200.
In another embodiment, the amine-terminated polyoxyalkylene is a triamine prepared by treating a triol with ethylene oxide, propylene oxide, or mixtures thereof, followed by amination of the terminal hydroxyl group. These amines are available commercially from Texaco Chemical Company under the tradename Jeffamine® triamines. Examples of these amines include, Jeffamine® T-403, which is trimethylolpropane treated with about 5-6 moles of propylene oxide, Jeffamine® T-3000, which is glycerine treated with 50 moles of propylene oxide, and Jeffamine® T-5000, which is glycerine treated with 85 moles of propylene oxide.
The diamines and triamines that are useful in accordance with the present invention are disclosed in U.S. Pat. Nos. 3,021,232; 3,108,011; 4,444,566; and Re. 31,522. The disclosures of these patents are incorporated herein by reference.
The above amines are reacted with the above polycarboxylic acid to form the amidic acids of the present invention. The process for preparing the amidic acids involves reacting the polycarboxylic acids with an amine at a equivalent ratio of about (2-4:1), more preferably (2:1), at room temperature to just below the temperature of imide formation, more preferably room temperature to 150° C., more preferably room temperature to 135° C. The reaction is usually accomplished within four hours, more preferably between 0.25 to about 2 hours.
In one embodiment, the amidic-acids and amidic-salts are represented by the formulae ##STR19## wherein each R 1 and R 4 is defined above; each R 12 is independently hydrogen, an alkyl group or polyoxyalkylene group; R 11 is an alkyl group or polyoxyalkylene group; n is 1 to about 150; and M is a hydrogen, an ammonium cation or a metal cation.
Preferably R 11 is an alkyl group, or a polyoxyalkylene group. When R 11 is an alkyl group, it is defined the same as R 12 . When R 11 is a polyoxyalkylene group, it is preferably a polyoxypropylene group or a polyoxypropylene-polyoxyethylene-polyoxypropylene group.
Preferably each R 12 is independently a hydrogen or an alkyl group having from 1 to about 20 carbon atoms, more preferably to about 8. In a preferred embodiment, each R 12 is independently an alkyl group having from 1 to about 8 carbon atoms. Preferably each R 12 is independently a methyl, ethyl, propyl, butyl or amyl group, more preferably a butyl or amyl group.
In another embodiment, the amidic-acid or amidic-salt is represented by Formula I, and R 12 is hydrogen and R 11 is a group having a tertiary carbon atom adjacent to the amino group. Preferably, R 11 is a tertiary aliphatic group having from about 4, preferably 6, more preferably 8 to about 28, preferably about 24 carbon atoms. Preferably, R 11 is a tert-octyl, tert-dodecyl, tert-tetradecyl, tert-hexadecyl, or tert-octadecyl group.
In another embodiment, the amidic-acid or amidic-salt is represented by Formula I wherein R 12 is a hydrogen and R 11 is a polyoxyalkylene group. Preferably R 11 is a polyoxypropylene group or a polyoxypropylene-polyoxyethylene-polyoxypropylene group.
In another embodiment, the amidic-acid or amidic-salt is represented by Formula II, wherein R 12 is hydrogen or a methyl group, preferably hydrogen. Preferably, each R 4 is independently an alkylene group having from 2 to about 8, more preferably 2 to about 4, more preferably 2 or 3 carbon atoms. Preferably, each R 4 is independently an ethylene or propylene group.
Preferably, each R 4 is independently an alkylene group having from 2 to about 8 carbon atoms, more preferably 2 to about 4. Preferably each R 4 is independently an ethylene or propylene group.
Preferably each n is independently 1 to about 150, more preferably 2 to about 50, more preferably 2 to about 20, more preferably from about 3 to about 10.
The following Examples relate to amidic-acids, amidic-salts, ester-acids and ester-salts of the present invention. Unless otherwise indicated in the following examples and elsewhere in the specification and claims, parts and percentages are by weight, temperature is degrees Celsius and pressure is atmospheric pressure. Neutralization number is the amount in milligrams of potassium hydroxide required to neutralize one gram of sample.
EXAMPLE 1
A reaction vessel, equipped with a mechanical stirrer and thermometer, is charged with 224 parts (0.8 mole) of tetrapropylene-substituted succinic anhydride, 72 parts (0.4 mole) of sorbitol and 20 milliliters of toluene. The reaction mixture is heated to 135° C. where 0.3 part of anhydrous sodium acetate is added to the mixture. The reaction mixture is stirred for 3.5 hours at 135° C. Toluene is removed by nitro9en blowing at 135° C. for about one-half hour. The product is a sticky amber semi-solid which has a neutralization number to phenolphthalein of 160 (theoretical 152).
An ammonium salt is prepared by adding 30 parts of the above product, 270 parts of cold tap water and 6.5 parts of concentrated ammonium hydroxide to a reaction vessel. The mixture is stirred for one-quarter hour at room temperature to produce the salt.
EXAMPLE 2
A reaction vessel, equipped with a mechanical stirrer, thermometer and nitrogen sparge, is charged with 165 parts (0.15 mole) of a polybutenyl-substituted succinic anhydride having a polybutenyl group having a number average molecular weight of about 950, and 42 parts (0.15 mole) of the succinic anhydride of Example 1. The anhydrides are stirred and heated to 90° C. where 27 parts (0.15 mole) of sorbitol, 0.25 part of anhydrous sodium acetate and 20 milliliters of toluene are added to the vessel. The mixture is heated to 140° C. and held with stirring for 4 hours under a nitrogen sparge of 0.2 standard cubic foot per hour (SCFH). The toluene is removed by nitrogen sparging at 1 SCFH at 140° C. for one-half hour. The product is a dark red-amber liquid having a neutralization number to phenolphthalein of 72.
An ammonium salt of the above product is prepared by dissolving 30 parts (0.038 equivalent) of the above product and 270 parts of tap water and 3.0 grams (0.044 equivalent) concentrated ammonium hydroxide. The mixture is stirred at room temperature for one-quarter hour to produce the salt.
EXAMPLE 3
A reaction vessel is charged with 165 parts (0.15 mole) of the polybutentyl succinic anhydride of Example 2, 42 parts (0.15 mole) of the tetrapropylene succinic anhydride of Example 1 and 45 parts (0.15 mole) of PEG-300, having approximately 300 molecular weight, available from Union Carbide Chemical Company. Then, 0.25 part of anhydrous sodium acetate and 20 milliliters of toluene are added to the reaction vessel. The mixture is heated to 140° C. and held for 3.5 hours with stirring. The toluene is removed by nitrogen blowing at 0.5 SCFH at 140° C. The product is a red-amber viscous liquid having a neutralization number to phenolphthalein of 72 (theoretical 67).
An ammonium salt of the above product is prepared by dissolving 30 parts (0.037 equivalent) of the above product in 270 parts of tap water and 3.0 parts (0.045 equivalent) of concentrated ammonium hydroxide. The mixture is stirred at room temperature for one-quarter hour to produce a salt.
EXAMPLE 4
A reaction vessel, equipped with a mechanical stirrer, a thermometer and a nitrogen inlet, is charged with 133 parts (0.5 equivalent) of the succinic anhydride of Example 1 and 150 parts (0.5 equivalent) of Carbowax 300, a polyoxyethylene glycol having approximately 300 molecular weight available from Union Carbide Chemical Co. The mixture is heated with stirring and nitrogen blowing at 0.3 SCFH to 150° C. and held for one hour. The product has a neutralization number to phenolphthalein of 103.5.
An ammonium salt of the above product is prepared by adding 100 parts (0.19 equivalent) of the above product to 90 parts of water and 10.5 parts (0.19 equivalent) concentrated ammonium hydroxide. The mixture is stirred for one-quarter hour at room temperature. The 50% aqueous solution has a pH of 7.0-7.5.
EXAMPLE 5
A vessel, equipped with a thermometer and a stirrer, is charged with 192 parts (0.5 mole) of Ethomeen C-15 and 130 parts (0.5 mole) of the succinic anhydride of Example 1. The reaction is exothermic. The reaction mixture is then heated to 110° C. and held for 2 hours. Infrared spectrum of the product shows no anhydride absorption peaks at 1770 C -1 and 1840 CM -1 . The product has a neutralization number of 84.
EXAMPLE 6
A reaction vessel is charged with 133 parts (0.5 mole) of the succinic anhydride of Example 1 and 80.5 parts (0.5 mole) of n-butyl diethanolamine. The reaction is exothermic to 80° C. The reaction mixtire is heated to 110° C. and stirred for 0.5 hours.
EXAMPLE 7
A reaction vessel is charged with 166 parts (0.5 mole) of a isomerized C 16 alpha-olefin substituted succinic anhydride and 74.5 parts (0.5 mole) of triethanolamine. The mixture is stirred on a roller for one-fourth hour. The vessel is heated to 100° C. and stirred on a roller for one-fourth hour.
EXAMPLE 8
A reaction vessel is charged with 47 parts (0.05 mole) of Ethoduomeen T-25 and 26 parts (0.1 mole) of the succinic anhydride of Example 1. The mixture is heated to 110°-120° C. and held for 2 hours with stirring. The product has a neutralization number to phenolphthalein of 60 (theoretical 76).
An amine salt of the above product was made by mixing 9.4 parts (0.01 equivalent) of the above product with 3.8 parts (0.01 equivalent) of Ethomeen C-15. The product is a dark amber viscous liquid.
EXAMPLE 9
Following the procedure of Example 8, 39 parts (0.15 mole) of the succinic anhydride of Example 1 and 47 parts (0.05 mole) of Ethoduomeen T-25 are reacted to form a product which has a neutralization number to phenolphthalein of 89 (theoretical 97). An ammonium salt of the above product is prepared by mixing 6.3 parts (0.01 equivalent) of the above product with 3.8 parts (0.01 equivalent) of Ethomeen C-15.
EXAMPLE 10
Following the procedure of Example 8, 26 parts (0.1 mole) of the succinic anhydride of Example 1 and 57 parts (0.1 mole) of Ethomeen C-15 are reacted to form a product which had a neutralization number to phenolphthalein of 74 (theoretical 67). An ammonium salt of the above product is prepared by mixing 8.4 parts (0.01 equivalent) of the above product with 3.8 parts (0.01 equivalent) of Ethomeen C-15.
EXAMPLE 11
Following the procedure of Example 8, 26 parts (0.1 mole) of the succinic anhydride of Example 1 and 42 parts (0.1 mole) of Unamide C-15, a cocamide treated with 5 moles of ethylene oxide, are reacted to form a product which had the neutralization number to phenolphthalein of 89 (theoretical 82). An ammonium salt of the above product is prepared by mixing 6.3 parts (0.01 equivalent) of the above product with 3.8 parts (0.01 equivalent) of Ethomeen C-15.
EXAMPLE 12
Following the procedure of Example 8, 26 parts (0.1 mole) of the succinic anhydride of Example 1 and 58 parts (0.1 mole) of Polyethylene Glycol 400 monolaurate are reacted to give a product which has a neutralization number to phenolphthalein of 71 (theoretical 66). An ammonium salt of the above product is prepared by reacting 7.9 parts (0.01 equivalent) of the above product with 3.8 parts (0.01 equivalent) of Ethomeen C-15.
EXAMPLE 13
A reaction vessel, equipped with a stirrer, thermometer, reflux condenser and addition funnel is charged with 269 parts of tetrapropenyl-substituted succinic anhydride. Then 374 parts Primene 81R (a mixture of C 12-14 t-alkyl primary amines available commercially from Rohm & Hass Co.) are added dropwise over 3 hours. The reaction is exothermic and the temperature of the reactant increases from room temperature to about 59° C. over the course of the amine addition. Stirring is continued for an additional hour at 55° C. After cooling to 40° C. the material is filtered and collected.
EXAMPLE 14
A reaction vessel, equipped as described in Example 1 is charged with 508 parts (2.0 moles) of tetrapropenyl-substituted succinic anhydride. The succinic anhydride is heated to 95° C., and 277 parts (2.1 moles) of dibutyl amine is added dropwise over 2 hours. The reaction is maintained at 95° C. for hour and cooled to room temperature. The product has 3.8% nitrogen and a neutralization number to phenolphthalein of 143.
EXAMPLE 15
A vessel, equipped as described in Example 1, is charged with 133 parts (0.5 mole) of tetrapropenyl-substituted succinic anhydride, 300 parts (0.5 mole) of Jeffamine M600, and 200 parts of xylene. The reaction mixture is heated to 135° C. under stirring. The temperature is maintained between 135° and 145° C. for 3 hours. Three and one-half milliliters of water is collected. The reaction is vacuum stripped to 135° C. and 10 millimeters of mercury. The residue is cooled to room temperature. The residue is a dark orange liquid which has 1.7% nitrogen.
EXAMPLE 16
A reaction vessel is charged with 288 parts (0.33 mole) of the product of Example 3 and 141 parts (0.33 mole) of Ethomeen C-15. The mixture is stirred for 10 minutes. The product is an orange clear liquid which has 2.2% nitrogen.
EXAMPLE 17
A reaction vessel is charged with 98 parts (0.25 mole) of the product of Example 2 and 101 parts (0.25 mole) of Ethomeen S/15. The mixture is stirred for 15 minutes. The product is an orange liquid having 3.2% nitrogen and a neutralization number to phenolphthalein of 58.2.
EXAMPLE 18
A reaction vessel is charged with 1064 parts (4.0 moles) of a tetrapropenyl-substituted succinic anhydride. Then, 640 parts (4.0 moles) of diamyl amine is added dropwise over 1.25 hours. The reaction is exothermic and the temperature rises to 57° C. from room temperature. The reaction mixture is then heated to 100° C. and held for 1.50 hours. The reaction mixture is cooled to 70° C. and 1193 parts (2.8 moles) of Ethomeen C/15 and 456 parts (0.9 moles) Ethomeen S/15 are added dropwise. The mixture is stirred for 15 minutes and an orange clear liquid product is obtained. The product has 3.28% nitrogen and a neutralization number to phenolphthalein of 67.5.
EXAMPLE 19
A reaction vessel is charged with 58 parts (0.12 mole) of an amidic-acid, prepared by reacting a tetrapropenyl succinic anhydride with a Jeffamine D-400 at a (2:1) equivalent ratio, and having a neutralization number to phenolphthalein of 119.5 and a percent nitrogen of 2.8%, and 16.1 parts (0.12 mole) of dibutylamine. The reaction mixture is heated to 50° C. and stirred for 50 minutes. The product is an orange-yellow syrup having a neutralization number to phenolphthalein of 99.5 and 4.5% nitrogen.
EXAMPLE 20
A reaction vessel is charged with 33 parts (0.13 mole) of a tetrapropenyl succinic anhydride, 140 parts (0.13 mole) of a polybutenyl succinic anhydride wherein the polybutenyl group has a number average molecular weight of about 950, and 50 parts (0.13 mole) of Jeffamine D-400. The mixture is stirred for 15 minutes. The reaction temperature rose to 80° C. The reaction mixture is heated to 100° C. for 45 minutes and stirred for 10 minutes. This intermediate product has a neutralization number to phenolphthalein of 74.2. Ethomeen C/15 (114 parts, 0.27 mole) is added to the vessel. The reaction mixture is stirred for 15 minutes. The product has a neutralization number to phenolphthalein of 48.7 and has 2.1% nitrogen.
EXAMPLE 21
A reaction vessel, equipped as described in Example 1, is charged with 280 parts (0.25 mole) of the polyisobutenyl succinic anhydride described in Example 8. The succinic anhydride is heated to 75° C. and the 40 parts (0.25 mole) of diamyl amine are added dropwise over 1 hour and 15 minutes. The reaction mixture is heated to 105° C. and the temperature is maintained for 11/4 hours. This intermediate product has a neutralization number to phenolphthalein of 62.1. Then 162 parts (0.25 mole) of Ethomeen C/20 are added at 82° C. and the reaction mixture is stirred for 15 minutes. The product is cooled to room temperature. The product has a neutralization number to phenolphthalein of 67.1, and 1.23% nitrogen.
EXAMPLE 22
A reaction vessel is charged with 39 parts (0.1 mole) of an amidic-acid prepared from a tetrapropenyl succinic anhydride and dibutyl amine and having a neutralization acid number to phenolphthalein of 143.5. Diethanol amine (10.6 parts, 0.1 mole) is added dropwise over 2 minutes, with stirring. The reaction mixture is stirred at room temperature for 15 minutes. The product has a neutralization acid number to phenolphthalein of 111 and 5.77% nitrogen.
As described above, the mixture used to treat the polymer fabrics are composed of (i) at least one ester-acid, ester-salt or mixture thereof, and (ii) at least one amidic-acid, amidic-salt or mixtures thereof. The mixture is composed of a sufficient amount of (i) and (ii) to provide wicking and wetting properties to the polymer fabric. In one embodiment, the amidic-acid, amidic-salt or mixture thereof is present in a major amount (greater than 50% by weight of the mixture). In this embodiment, the ester-acid, ester-salt or mixture thereof is present in a minor amount (less than 50% by weight of the mixture). In another embodiment, (i) the ester-acid, ester-salt or mixture thereof is present in an amount from about, 1%, preferably about 10% to about 99%, preferably about 75%, more preferably about 40%, more preferably about 30% by weight of the mixture. The amidic-acid, amidic-salt or mixture thereof is present in an amount from about 1%, preferably about 25%, more preferably about 60%, more preferably about 70% to about 99%, preferably about 95 %, more preferably about 90% by weight of the mixture. A useful mixture composed of 80% by weight of an amidic-acid, amidic-salt or mixture thereof and 20% by weight of an ester-acid, ester-salt or mixtures thereof.
The polymer fabrics are generally treated with about 0.25%, preferably about 0.5%, more preferably about 0.75% up to about 5%, preferably about 3%, more preferably about 2%, more preferably about 1% by weight of the mixture in an organic or aqueous mixture. The mixture may be a solution or dispersion. The organic mixture may be prepared by using volatile organic solvents. Useful organic solvents include alcohols, such as alcohols having from 1 to about 6 carbon atoms, including butanol and hexanol; or ketones, such as acetone or methylethylketone. Preferably the wetting agents are applied as an aqueous solution or dispersion. The wetting agents may be applied either by spraying the fabric or dipping the fabric into the mixture. After application of the wetting agents, the treated fabric is dried by any ordinary drying procedure such as drying at 120° C. for approximately 3 to 5 minutes.
A cowetting agent may be used to reduce wetting time of the above aqueous mixture. The cowetting agent is preferably a surfactant, more preferably a nonionic surfactant. Useful surfactants include the above described alkyl-terminated polyoxyalkylenes, and alkoxylated phenols. Preferably, the surfactant is an alkyl-terminated polyoxyalkylene.
The wetting time of the mixture may also be reduced by heating the mixture. Usually the mixture is applied at room temperature. However, a 10°-15° C. increase in temperature significantly reduces wetting time.
Preferably, after drying the treated polymer fabrics have from about 0.1, preferably about 0.5 to about 3%, preferably to about 1%, more preferably to about 0.8% pickup based on the weight of the fabric. Percent pickup is the percentage by weight of the mixture on a polymer fabric.
The following Table I contains examples of mixtures useful in the present invention.
TABLE I______________________________________ Ester-Acid, Amidic-Acid, WeightExamples Ester-Salt Amidic-Salt Ratio______________________________________A Example 1 Example 13 90:10B Example 2 + Example 14 10:90 Example 3 (50:50)% weightC Example 4 Example 22 40:60D Example 5 Example 17 50:50E Example 6 Example 18 20:80F Example 7 Example 20 + 25:75 Example 16 (75:25)% weightG Example 8 Example 21 5:95______________________________________
The following Table II contains examples of polypropylene fabrics treated with aqueous solutions or dispersions of the mixture (B). The polymer fabric may be any polypropylene fabric available commercially. The aqueous solution or dispersion contains at least one of the mixtures in the amount shown in the Table. The polypropylene fabric is dipped into the aqueous solution or dispersion and then dried for 3-5 minutes at 125° C.
TABLE II______________________________________ Amount Mixture (B)Examples Mixture (B) In Water______________________________________I Example A 1%II Example B 0.75%III Example C 0.5%IV Example D 0.75%______________________________________
The treated polymer fabrics have improved hydrophilic character. The treated fabrics show an improvement in the wicking/wetting ability of the fabrics. The polymer fabrics of the present invention may be formed into diapers, feminine products, surgical gowns, breathable clothing liners and the like by procedures known to those in the art.
The properties of the treated fabrics or products made with the fabrics may be measured by ASTM Method E 96-80, Standard Test Methods for Water Vapor Transmission of Materials, and INDA Standard Test 80 7-70 (82), INDA Standard Test for Saline Repellency of Nonwovens, often referred to as the Mason Jar Test. The latter test uses a 0.9% by weight saline solution.
While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.
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The invention relates to a composition mixture comprising (i) at least one ester-acid, ester-salt or mixtures thereof and (ii) at least one amidic-acid, amidic-salt or mixtures thereof a polymer fabrics treated with the same. The treated polymer fabrics have improved wicking/wetting characteristics. The treated polymer fabrics maintain these characteristics upon repeated exposure to aqueous fluids.
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BACKGROUND OF THE INVENTION
The invention is based on a damping device as generally defined hereinafter. A damping device has already been proposed in which the damper element has a feed pipe which engages a flow tube that pierces a fuel distributor line and communicates with a fuel supply line; between itself and the flow tube, the feed pipe forms a flow cross section with respect to the fuel distributor line. The disadvantage here, however, is that in order to save weight and space, the flow cross section between the feed pipe and the flow tube is kept relatively small, so that the damper element does not adequately damp both pressure fluctuations in the fuel distributor line, which are caused by pressure pulses in the injection valve, and pressure fluctuations originating in the fuel supply line, which are caused by the fuel feed pump.
OBJECT AND SUMMARY OF THE INVENTION
The damping device according to the invention has the advantage over the prior art that the damper element is simple to assemble with the fuel distributor line and together with the fuel distributor line is simple in structure; meanwhile little space is required to install the damper element, and both pressure fluctuations in the fuel distributor line and in the fuel supply line are damped.
Not only is it advantageous to join the feed pipe to the damper housing in order to facilitate assembly, but a further advantage is attained if the feed pipe is molded integrally on the damper housing. A particularly simple embodiment is attained if the damper housing and the fuel distributor line ar soldered together, because then seals and screws can be dispensed with.
A further advantage is that one feed pipe and the flow tube are axially spaced apart from one another, so that although fuel pressure fluctuations arising in the flow tube do act directly upon the damper element, not all the fuel flowing in via the flow tube has to flow into the damper.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows generally in cross-section a first exemplary embodiment of a damping device according to the invention;
FIG. 2 shows a further cross-sectional view of a second exemplary embodiment of a damping device according to the invention; and
FIG. 3 shows in cross-section a third exemplary embodiment of a damping device according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, reference numeral 1 indicates a rigid fuel distributor line, made for instance of metal, of a fuel injection system for internal combustion engines. The fuel distributor line has a plurality of plug connections 2, into which one end of fuel injection valves are inserted. A fastening flange 3 is joined, for instance by soldering, to the wall of the fuel distributor line 1, and a first flow opening 4, which coincides with a first opening 5 in the fuel distributor line 1, and a second flow opening 6, which coincides with a second opening 7 in the fuel distributor line 1, are provided in the fastening flange 3. The openings 5 and 7 in the fuel distributor line are located along the longitudinal axis of the fuel distributor line 1, spaced apart axially from one another. In alignment with the first opening 5 of the fuel distributor line 1, a flow tube 9 originating on the side of the fuel distributor line 1 opposite the first opening 5 at least partially pierces the fuel distributor line 1 and may optionally project so far as to extend into the first flow opening 4 of the fastening flange 3. The flow tube 9 communicates with a fuel supply line, not showh, which is connected to the supply outlet of a fuel feed pump (not shown) that pumps in a pulsating manner. When the flow pipe 9 projects into the first opening 5, the end 10 of the flow tube 9 that protrudes into the first opening 5 has a substantially smaller diameter than the first opening 5, so that between the circumference of the flow tube 9 at the end 10 and the first opening 5 or the first flow opening 4, fuel can flow unrestricted and freely into an annular cross section.
Remote from the fuel distributor line 1, a fastening flange 11 rests on the fastening flange 3 and the two flanges are joined with screws 12. The fastening flange 11 is in turn secured to a bottom part 13 of a damper element 14, for instance by soldering. In the bottom part 13, a first feed pipe 16 and a second feed pipe 17 are molded in such a way that they project from the bottom part 13, in fact such that when the fastening flange 11 and the fastening flange 3 are screwed together, the first feed pipe 16 is arranged to coincide with the first flow opening 4 or the first opening 5, and the second feed pipe 17 comes to coincide with the second flow opening 6 or the second opening 7. Seals in the form of seals 18, 19 are placed about the necks of feed pipes 16, 17, effecting sealing off and preventing leakage from the outside between the fastening flange 3 and the bottom part 13. Between the bottom part 13 and a lid 20 of the damper element 14, a resilient damper diaphragm 22 is fastened by means of a crimped edge 21, and in the damper element 14 the diaphragm 22 divides a fuel chamber 23, which communicates with the feed pipes 16, 17, from a damper chamber 24. A compression spring 26 is disposed in the damper chamber 24 and is supported at one end on the lid 20 and on the other on a spring support plate 27, which is secured to the damper diaphragm 22 by means of a rivet connection 28 which passes in a sealed manner through the damper diaphragm 22. The rivet connection 28 has a stop bolt 29 protruding into the fuel chamber 23, and at a predetermined allowable flexing of the damper diaphragm 22 this stop bolt 29 comes to rest on the inner wall of the bottom part 13. As a result, overstretching of the damper diaphragm 22 by the compression spring 26 in the pressureless state is avoided.
The inside diameters of the openings 5, 7, the flow openings 4, 6 and the feed pipes 16, 17 are selected to be as large as possible, so as to enable a free flow of fuel and an unhindered propagation of pressure fluctuations into the fuel chamber 23 of the damper element 14. The first feed pipe 16 and the flow tube 9 are spaced apart axially from one another by a distance A, so that fuel flowing in via the flow tube 9 does not have to flow exclusively into the fuel chamber 23, but rather can also, after it emerges from the flow tube 9, flow via the annular flow cross section between the circumference of the flow tube and the first flow opening 4 and the first opening 5 into the fuel distributor line 1. By means of the embodiment according to the invention, both pulsations of the fuel that are caused by the fuel feed pump and pulsations arising from the opening and closing of the fuel injection valves, which reach the fuel chamber 23 through the fuel distributor line 1, are damped.
In the second exemplary embodiment of a damping device shown in FIG. 2, elements remaining the same as and functioning like those in the exemplary embodiment of FIG. 1 are identified by the same reference numerals. Differing from the embodiment of FIG. 1, the bottom part 13 of the damper element 14 of FIG. 2 has insertion openings 31 and 32, into which tubular feed pipes 33 and 34 are inserted and joined with the bottom part, for instance by soldering. The feed pipes 33 and 34 protrude out from the bottom part 13 and may extend, for instance, as far as into the flow openings 4, 6 of the fastening flange 11. The end 10 of the flow tube 9 and the feed pipe 34 are oriented approximately in alignment with one another and are axially spaced apart from one another by an axial distance A, with the end 10 of the flow tube 9 terminating inside the fuel distributor line 1, so that a portion of the fuel flowing in via the flow tube 9 can immediately flow into the fuel distributor line 1. The distance A amounts to approximately 2 to 5 mm. A stop bolt 35 is joined to the bottom part 13 on one end, and on the other end it is oriented toward a stop plate 36 of the rivet connection 28 on the damper diaphragm 22, so that the movement of the damper diaphragm 22 in the direction toward the feed pipes 33, 34 is limited by the stop bolt 35. The feed pipes 33, 34 form sufficiently large cross sections so that pressure pulsations coming from the fuel distributor line 1 and from the flow tube 9 are rapidly deviated to the fuel chamber 23 and cancelled out.
In the third exemplary embodiment shown in FIG. 3, the elements that are the same as and function like those in the foregoing embodiments of FIGS. 1 and 2 again have the same reference numerals. Differing from the foregoing embodiments, in the embodiment of FIG. 3 the securing flanges 3, 11 and the screws 12 are lacking. The feed pipes 16, 17 formed onto the bottom part 13, or the feed pipes 33, 34 joined to the bottom part 13, protrude directly into the openings 5, 7 of the fuel distributor line 1 in the third exemplary embodiment of FIG. 3. Moreover, the bottom part 13 is soldered to the fuel distributor line 1 at 37 in the resultant plane between these two parts [i.e., between 1 and 13] in such a way that a fuel-tight connection is brought about between the surfaces of the fuel distributor line 1 and of the bottom part 13.
The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
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A damping device is proposed, which serves to equalize and reduce pressure fluctuations arising in fuel supply systems for internal combustion engines in motor vehicles. The damping device includes a damper element which has at least one damper diaphragm fastened in a damper housing and is arranged to define a fuel chamber which communicates via a feed pipe with a fuel distributor line. The feed pipe is oriented toward a flow tube which communicates with a fuel supply line and protrudes into the fuel distributor line. The fuel chamber of the damper element communicates via a further feed pipe with the fuel distributor line. The feed pipe and the flow tube are axially spaced apart from one another by a distance (A).
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