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TECHNICAL FIELD
[0001] The present invention relates to a method of diagnosing at a car dealer or a maintenance factory a driving operation of a vehicle for improvement of the fuel efficiency and to a method of ordinary fault diagnosis of a vehicle.
BACKGROUND OF THE INVENTION
[0002] Recently, users' concern relating to fuel efficiency (mileage) has risen. People prefer more fuel-efficient driving. Users who purchased vehicles tend to bring complaint and dissatisfaction suspecting malfunction when the fuel efficiency is lower than they expected.
[0003] The mileage of a vehicle per unit quantity of the fuel consumption represents the fuel efficiency. The patent literature 1 describes determination between right and wrong by comparing a current mileage with a predetermined target mileage, wherein determined result is informed to the user (driver).
[0004] Patent literature 2 discloses a scheme wherein, responsive to a state of fuel efficiency, at least one of intensity and tone for indicating the fuel efficiency is changed. For example, every time the fuel efficiency changes by a predetermined value, the intensity or tone is changed.
[0005] Patent literature 3 describes that behavior data of a vehicle is received from a car navigation device, driving attributes (properties) are determined from the behavior data, and distribution of acceleration is statistical processed to perform safety diagnosis. The fuel consumption is obtained from behavior data, and diagnosis is performed with respect to a fuel saving driving. In this method, with the use of a car navigation device, behavior data of the vehicle is transmitted to a driving diagnosis server, so, not only a load on the car navigation device is increased, but also the car navigation device itself needs a design change for use with this system.
DESCRIPTION OF THE PRIOR ART
Patent Literature
[0006] Patent literature 1
[0007] Japanese Patent Application Publication No. 2003-42000
[0008] Patent literature 2
[0009] Japanese Patent Application Publication No. 2007-256158
[0010] Patent literature 3
[0011] Japanese Patent Application Publication No. 2006-243856
SUMMARY OF THE INVENTION
Problems to be Resolved by the Invention
[0012] According to existing methods, a driver is informed whether the fuel efficiency is right or wrong, and whether the fuel efficiency is decreasing or increasing by use of the intensity and tone. Information like this is a mere notification about the operation during driving or about a good or bad fuel efficiency under the current situation. No information is provided about driving habits, about what driving operation caused a bad fuel consumption, or about how the driving operation may be improved.
[0013] Therefore, for complaint and dissatisfaction for fuel efficiency, diagnosis that can be performed in the same manner as ordinary failure diagnosis at a maintenance factory is desired. A scheme is desired wherein the diagnosis result may be presented to the user together with background data and advice may be given to the driver as to with what driving operation the fuel efficiency may be improved.
Means of Solving the Problem
[0014] A diagnosis apparatus of the present invention includes an electronic control unit comprising a non-volatile memory for storing driving data which indicate a state of fuel efficiency of the vehicle responsive to a driving operation in each driving cycle. The apparatus includes means for reading out driving data for multiple driving cycles from the electronic control unit, means for producing a chart showing a state of fuel efficiency for each driving operation by a driver in each driving cycle based on the retrieved driving data, and means for outputting the chart on a display device or a printer as a comparative result for each driving cycle.
[0015] According to the invention, for complaint and dissatisfaction for the fuel efficiency, diagnosis may be performed at a maintenance factory in a similar manner to an ordinary fault diagnosis of a vehicle, and the result of the diagnosis, an evaluation of driving operation and advice may be provided to the user along with background data. Thus, the user will recognize what kind of driving should be performed in order to get a better fuel efficiency.
[0016] According to one embodiment of the invention, a driving cycle is a driving period from turning the ignition of a vehicle ON to turning it OFF. When at least one of driving speed or driving distance does not reach a predetermined value, or when the engine is not rotating for a certain period after the engine is started, the electronic control unit is designed not to store driving data of this driving cycle in the non-volatile memory.
[0017] According to another embodiment of this invention, for each item of driving operation having an effect on a fuel efficiency, driving data includes evaluation scores calculated by an electronic control unit and advice messages to be presented to the user with respect to the state of fuel efficiency. The diagnosis device selects and visually outputs the advice message for the term of driving operation given a low evaluation score from multiple advice messages retrieved from the electronic control unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a block diagram of a relationship between an in-vehicle system and a diagnosis device at a service shop.
[0019] FIG. 2 is a functional block diagram of a control unit 40 of an in-vehicle system.
[0020] FIG. 3 is a diagram illustrating a method of getting a accelerator score according to accelerator operation.
[0021] FIG. 4 is a diagram illustrating a method of getting a accelerator score according to accelerator operation.
[0022] FIG. 5 is a diagram illustrating a method of getting a brake score according to brake operation.
[0023] FIG. 6 is a diagram illustrating a method of getting a brake score according to brake operation.
[0024] FIG. 7(A) is a diagram illustrating a method of getting a score according to an idling drive, FIG. 7(B) is a diagram illustrating one embodiment of a map which converts a total score to a value to calculate a life score.
[0025] FIG. 8 illustrates one embodiment of an accumulation of each score according to driving operation.
[0026] FIG. 9 is a flow chart which illustrates a process to calculate a total score.
[0027] FIG. 10 illustrates relationships between a vehicle speed and a fuel efficiency.
[0028] FIG. 11 illustrates one embodiment of advice messages.
[0029] FIG. 12 illustrates one embodiment of screen showing the diagnosis result of the driving which is displayed by a diagnosis device.
[0030] FIG. 13 illustrates another embodiment of screen showing the diagnosis result of the driving which is displayed by a diagnosis device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] Embodiments of the present invention are described below with reference to the drawings. FIG. 1 is a block diagram showing general relationship between an in-vehicle electronic control unit (ECU) and a diagnosis device of this invention. Electronic control unit 14 is a computer controlling such as fuel injection and an air-fuel ratio of a vehicle. Electronic control unit 14 comprises CPU 14 A, and RAM 14 B which provides a work area to the CPU and stores a program and data temporarily. ECU 14 also includes ROM 14 C which is a read-only memory saving a computer program, rewritable nonvolatile memory 14 D which maintains memory even after the power of the vehicle is turned off, input interface 14 F, and output interface 14 G.
[0032] ECU 14 receives output signal through in-vehicle network 11 from sensors mounted on various parts of the vehicle. The sensors include a vehicle speed sensor 11 A which detects vehicle speed, an accelerator opening degree sensor 11 B which detects degree of pressing on an accelerator, a brake opening degree sensor 11 C which detects a degree of pressing on a brake, a throttle opening degree sensor 11 E which detects a opening angle of a throttle, and crank angle sensor 11 F which is a base for timing of various controls.
[0033] Service shop 16 is a dealer shop for providing a maintenance service for vehicles. Service shop 16 is provided with a diagnosis system (HDS) 16 A for reading out for diagnosis data from the ECU of a vehicle, the data being stored in the ECU during driving. In service shop 16 , in a similar manner as ordinary failure diagnosis, a tablet terminal device of HDS 16 A is connected through a data link connector called DLC to ECU 14 of a vehicle brought for a diagnosis of fuel efficiency, and data saved in nonvolatile memory 14 D is read out. The tablet terminal device of HDS 16 A is a tablet mobile terminal developed specifically for the diagnosis system, and is connected to the ECU of the vehicle through DLC for reading out data saved in the ECU. The tablet terminal device of HDS 16 A may be coupled to a docking station to connect to a communications network in service station 16 , and may be connected to personal computer 16 B in service shop 16 , which forms the diagnosis device together with HDS. The tablet terminal device of HDS 16 A provides read out data from ECU 14 to personal computer 16 B.
[0034] The tablet terminal device of HDS 16 A converts the read out data to a xml file. Personal computer 16 B edits and processes the data received from HDS 16 A by a viewer program, and displays the data on display device 16 D such as liquid-crystal display or CRT, or prints out the data by printer 16 E.
[0035] Personal computer 16 B may be a notebook PC, thereby forming a mobile diagnosis device. PC 16 B may not be a separate PC. A tablet terminal device may be integrated with functions of personal computer and a monitor (display device) to form a tablet diagnosis device with a function of a monitor.
[0036] In addition, HDS 16 A can perform a fuel efficiency diagnosis function according to the present invention and an ordinary fault diagnosis function with the same hardware.
[0037] Data relating to fuel efficiency, saved in nonvolatile memory 14 D of ECU 14 and read out by tablet terminal device HDS 16 A, include historical data for five driving cycles (D/C) and data at the end of the latest driving cycle. The Examples of data items of the historical data are shown in table 1 for five driving cycles. Every time driving cycle finishes, historical data in the latest driving cycle is saved additionally, and data of the oldest driving cycle (five-cycle old) is erased, thus, data of the past 5 driving cycles including the latest data are saved.
[0038] Examples of data saved in each end of the latest driving cycle are shown in table 2. The driving cycle to be saved in a nonvolatile memory is the driving cycle wherein a vehicle is driven over 200 meters after vehicle speed reaches over 8 k/m and engine rotation continues over 3 minutes from the start of the engine. A driving cycle (D/C) that fails to fulfill these conditions may not provide sufficient data from the view point of an evaluation of fuel efficiency, because it is inadequate as a subject for evaluating driving operation. Therefore, when at least one of driving speed or driving distance does not reach a predetermined value or when the engine does not rotate continuously for a predetermined period from starting the engine driving data for this driving cycle as shown in the table 1-2 is not recorded in the non-volatile memory. Thus, only those driving data that are adequate for evaluation are selected and saved for the latest five driving cycles in the non-volatile memory.
[0000]
TABLE 1
Item
Unit
Explanation
Accelerating score
Point
Score of accelerator operation in each
(D/C)
Braking score
Point
Score of brake operation in each D/C
Idling score
Point
Score of idling operation in each D/C
Total score of D/C
point
Total score for three operations in each
D/C
Average speed
km/h
Average speed of vehicle in each D/C
(1D/C)
Driving time
Second
Driving time of vehicle in each D/C
(1D/C)
Accelerating
HEX
Advice message for accelerator operation
message
in each D/C
Braking message
HEX
Advice message for brake operation in
each D/C
Idling message
HEX
Advice message for idling operation in
each D/C
Fuel consumption
cc
Fuel consumption by idling in each D/C
for idling
Idling time
second
Not including idling stop time
Idling stop time
second
Idling stop time
Fuel consumption
cc
Fuel consumption for driving at a speed
(City)
lower than 72 km/h
Fuel consumption
cc
Fuel consumption for driving at a high
(Highway)
speed of over 72 km/h
Driving distance
m
Driving distance for driving at a speed
(City)
lower than 72 km/h
Driving distance
m
Driving distance for driving at a high
(Highway)
speed of over 72 km/h
[0000]
TABLE 2
Item
Unit
Explanation
The use of ECON
%
Frequency of use of ECON switch
switch
Driving time (using
minute
Driving distance for calculating the use
ECON switch)
of ECON switch
Lifetime total score
point
Lifetime score of vehicle
ECO class
HEX
Information on ECO class
[0039] Now, the content of each data included in the table 1-2 will be described.
[0040] FIG. 2 is a block diagram of controller 40 installed in a vehicle and generates driving data according to driving operation by a user. Controller 40 includes electronic control unit (ECU) 14 described with reference to FIG. 1 .
[0041] Driving condition detector 41 detects whether an accelerator operation of a vehicle is performed or not and whether a braking operation of the vehicle is performed or not. Various sensors 65 are installed in vehicle. The examples of sensors are shown in FIG. 1 . Driving condition detector 41 detects a diving operation based on output from sensors 65 .
[0042] When driving condition detector 41 detects that the accelerator operation is accelerator operation is performed, a driving condition of the vehicle corresponding to the accelerator operation is determined based on engine rotation and a throttle opening degree. Engine rotation can be calculated based on crank angle sensor 11 F installed in the vehicle. A throttle valve is installed in a suction passage to an engine, an opening angle of the throttle valve is detected by throttle opening degree sensor 11 E.
[0043] When driving condition detector 41 detects that the braking operation is performed, a driving condition of the vehicle corresponding to the braking operation is determined by a vehicle speed and negative acceleration. The vehicle speed and the acceleration can be detected by vehicle speed sensor 11 A installed in the vehicle. An acceleration of a vehicle may be detected by an acceleration sensor installed.
Data of an Accelerating Score
[0044] Accelerator scoring unit 43 , based on a driving condition according to an accelerator operation, calculates a score for the accelerator operation by evaluating the accelerator operation from the view point of fuel efficiency.
[0045] One example of a map preliminarily stored in ROM 14 C of controller 40 is shown in FIG. 3( a ). A horizontal axis of the map shows an engine rotational speed (rpm) and a vertical axis shows throttle opening degree (deg.). Line 111 represented by bold solid line is a line representing, predetermined optimum values of BSFC (Brake Specific Fuel Consumption, an unit is (g/kWh)) called net fuel consumption rate, or a driving condition to realize a value set as a best fuel efficiency. This is preliminarily determined depending on engine characteristics with respect to each engine rotational speed and throttle opening degree. If the throttle opening degree is about 40 deg. as shown by the dot of sign 112 when the engine rotational speed is 3000 rpm, it is shown that the optimum net fuel consumption rate can be achieved.
[0046] In FIG. 3 , it is not shown that the region wherein the engine rotational speed is less than approximately 800 rpm. This is the region wherein the engine is in the idling condition, and a control in the idling driving condition will be described below.
[0047] In FIG. 3 , when values of revolutions are the same, the higher the throttle opening degree, the lower the fuel efficiency is. There, in this case, a driving region is divided into three regions in the direction of longitudinal axis to set the three fuel efficiency conditions consisting of a good condition, a non-good condition, and a condition between the good condition and the non-good condition. In particular, it is divided into regions near line 111 of BSFC, the lower region of the region near line 111 of BSFC, and the higher region of the region near line 111 of BSFC, these regions are delimited by lines of 113 and 115 . The region lower than line 113 is a first region, the region between line 113 and line 115 is a second region, and the region higher than line 115 is a third region. The first region is the region in which the fuel efficiency is good, the third region is the region in which a fuel efficiency is not good, and the second region is in between them and is set as the region non-reaching to the non-good region.
[0048] The third region is equivalent to a driving region wherein an accelerator operation with a rapid acceleration is performed or a vehicle speed is too faster. The second region is equivalent to a driving region wherein an accelerator operation leads to gradual speed-up, and the first region is equivalent to a driving region in which a accelerator operation as executing cruise driving is performed and a vehicle speed is too faster.
[0049] Accelerator scoring unit 43 refers to a map based on an engine rotational speed (NE) detected according to an accelerator operation and detected throttle opening degree (TH), determines a length of described bar 39 and background color 33 . It is assumed that the detected engine rotational speed NE is 2000 rpm. Line 117 indicating 2000 rpm of revolutions is shown in the direction of a longitudinal axis. The throttle opening degree corresponding to intersection point C 1 between line 117 and line 113 is TH 1 , the throttle opening degree corresponding to intersection point C 2 between line 117 and line 115 is TH 2 , and the maximum value (90 degrees) of throttle opening degree is TH 3 .
[0050] On the other hand, FIG. 3( b ) illustrates accelerator region Ar, a position in the direction of a horizontal axis of accelerator region Ar is shown corresponding to a reference position R. An non-hatched region shows the condition of the accelerator operation with a good fuel efficiency, and hatched region shows the condition of the accelerator operation with a non-good fuel efficiency.
[0051] In FIG. 3( b ), the range from reference position R to first position PA 1 corresponds to the first region of map in FIG. 3( a ), the range from first position PA 1 to second position PA 2 corresponds to the second region, and the range from second position PA 2 to third position PA 3 corresponds to the third region. The distance from the reference position to PA 1 -PA 3 of the first-third positions are shown by LA 1 , LA 2 , and LA 3 , respectively. Accordingly, when the engine rotational speed NE is 2000 rpm, the range from zero to TH 1 , of the throttle opening degree, are allocated to the range from position R to position PA 3 , the range from TH 1 to TH 2 , of the throttle opening degree, are allocated to the range from position PA 1 to position PA 2 , the range from TH 2 to TH 3 , of the throttle opening degree, are allocated to the range from position PA 2 to position PA 3 .
[0052] Accelerator scoring unit 43 calculates on a pro-rata basis in which region in the map in FIG. 3 , a driving operation condition exists, which is represented by a detected engine rotational speed and a throttle opening degree. If it exists in the first region, the length of the bar 39 is calculated by LA 1 ×TH/(TH−0). If it exists in the second region, the length of the bar 39 is calculated by LA 1 +(LA 2 −LA 1 )×(TH−TH 1 )/(TH 2 −TH 1 ). If it exists in the third region, the length of the bar 39 is calculated depending by LA 2 +(LA 3 −LA 2 )×(TH−TH 2 )/(TH 3 −TH 2 ).
[0053] The bar 39 is an index to display an accelerator operation quantity or a braking operation quantity, on second display unit 15 , in real time, by expansion and contraction of a length to the right or to the left in the drawings. This display refers to the display in the vehicle, and does not refer to the present invention directly, so a description of a display by bar is omitted.
[0054] Accelerator scoring unit 43 , further, based on the calculated length of bar 39 , refers to map 121 in FIG. 4 , and gets a score for the current accelerator operation. The map is stored preliminarily in ROM 14 C of controller 40 . In this embodiment, the scope of a score is from zero to 100 points, the 100 points corresponds to reference position R, and zero point corresponds to the position where is the length of LA 3 away from reference position R. In an embodiment in FIG. 4 , the score corresponding to the length of the bar 39 is 90 points. As shown in FIG. 4 , the shorter the length of bar 39 or the better a fuel efficiency of accelerator operation is performed, the higher score can be gotten.
[0055] In this embodiment, the score is shown by an integer. Therefore, when the score corresponding to the length of bar 39 is with a decimal point, for example, the integer can be gotten by rounding.
[0056] Thus, during an accelerator operation, a score evaluated form the view point of fuel efficiency is calculated by accelerator scoring unit 43 at specified time intervals. This score is called an accelerator score (accelerating score). During drive cycle of a vehicle, the accelerator score is calculated sequentially at specified time intervals and stored in RAM 14 B, and used for calculating a total score and an average value of accelerator scores.
Braking Score
[0057] Now, braking scoring unit 44 in FIG. 2 will be described. Braking scoring unit 44 , based on a detected driving condition according to a braking operation, calculates the score for the braking operation by evaluating the braking operation from the view point of fuel efficiency.
[0058] Referring to FIG. 5 , one example of a preliminarily stored map in the memory of controller 40 is shown in (a). An horizontal axis of the map shows vehicle speed (km/h), a longitudinal axis shows acceleration (m/sec 2 ). And, the map has negative values because of a deceleration. Line 131 represented by bold solid line are values representing accelerations when a predetermined sudden braking operation is performed, during a usually driving (in this embodiment, vehicle speed is faster than almost 15 km/h). This is determined preliminarily through a simulation or the like. In this embodiment, it is set in −6 m/sec 2 but this is one example and it is not limited to this value.
[0059] In FIG. 5 , when vehicle speeds are the same, the bigger an absolute value of acceleration, the lower a fuel efficiency is. There, in this embodiment, driving region can be divided into three regions in the direction of longitudinal axis to set the three fuel efficiency conditions consisting of a good condition, a non-good condition, and the condition between the good condition and the non-good condition as well as an accelerator operation. Specifically, as a fuel efficiency is not in good condition, a third region including line 131 is set lower than line 133 , the third region corresponds to a driving region in which a braking operation leads to a rapid deceleration. And, a first region is set higher than line 135 as the region in which a fuel efficiency is good, and this is equivalent to a driving region in which the braking operation is performed with power that can stop a vehicle if the vehicle keep a safe distance between oneself and the car ahead. A second region is set between line 133 and line 115 as a region in which a fuel efficiency is comparatively good and does not reach to the non-good region. The first region and the second region are, further, if a braking operation is performed in these regions, on low μ road (road in which static friction coefficient μ is low), set as a driving region in which a slipping can be avoided more definite. Thus, the first region and the second region can be thought as the driving region in which a rapid deceleration is not performed and it is a safer driving region. Line 133 and line 135 delimiting the regions from first to three are determined preliminarily through a simulation or the like.
[0060] Thus, braking scoring unit 44 refers to the map set preliminarily and stored in the memory on a basis of vehicle speed (VP) and an acceleration (DR) detected, and determines the length of described bar 39 .
[0061] It is assumed that the detected vehicle speed (VP) is 70 km/h. Line 137 showing vehicle speed of 70 km/h is shown in a longitudinal axis direction. An acceleration corresponding to an intersection point D 3 between line 137 and line 131 is DR 3 , an acceleration corresponding to an intersection point D 2 between line 137 and line 133 is DR 2 , an acceleration corresponding to an intersection point D 1 between line 137 and line 135 is DR 1 .
[0062] In FIG. 5( b ), a braking region is illustrated, a position of braking region in the horizontal axis direction is illustrated corresponding to a reference position R. A non-hatched region illustrates a condition of the braking operation with a good fuel efficiency, and a hatched region illustrates a condition of the braking operation with a non-good fuel efficiency. First position PB 1 is set on a position corresponding to end DR 1 of the first region in FIG. 5( a ). Second position PB 2 is set on a position corresponding to end DR 2 of the second region in FIG. 5( a ), a position of the left end of hatched region is set on third position PB 3 . The distances from the reference position to the positions PB 1 -PB 3 of the first-third positions are illustrated by LB 1 , LB 2 , and LB 3 , respectively.
[0063] For example, when a detected vehicle speed VP is 70 km/m, the range from zero to DR 1 , of an acceleration, are allocated to the range from position R to position PB 1 , the range from DR 1 to DR 2 , of the acceleration, are allocated to the range from position PB 1 to position PB 2 , and the range from DR 2 to DR 3 , of the acceleration, are allocated to the range from position PB 2 to position PB 3 .
[0064] Braking scoring unit 44 determines a region of the map where a driving condition indicated by a detected vehicle speed VP and a detected acceleration DR are present. If it is present in the first region, the length of bar 39 is calculated on a pro-rata basis: LB 1 ×|DR|/|DR 1 |.
[0065] Here, | | shows an absolute value. And, if acceleration DR is present in second region 39 is calculated by LB 1 +(LB 2 −LB 1 )×(|DR|−|DR 1 |)/(|DR 2 |−|DR 1 |). If acceleration DR is present in the third region, the length of the bar 39 is calculated by LB 2 +(LB 3 −LB 2 )×(|DR|−|DR 2 |)/(|DR 3 |−|DR 2 |).
[0066] Braking scoring unit 44 , further, based on the calculated length of the bar 39 , refers to map 141 in FIG. 6 , and gets a score for the current braking operation. The map is stored preliminarily in ROM 14 C of controller 40 . In this embodiment, the scope of a score is from zero to 100 points, the 100 points corresponds to reference position R, and zero point corresponds to a position where is the length of LB 3 away from reference position R. In an embodiment in FIG. 6 , the score corresponding to the length of bar 39 is 70 points. As shown in FIG. 6 , the better fuel efficiency of braking operation is performed, the higher score can be gotten.
[0067] In this embodiment, the score is shown by an integer. Therefore, when the score corresponding to the length of the bar 39 is with a decimal point, for example, the integer can be gotten by rounding.
[0068] Thus, during a braking operation, a score evaluated form the view point of fuel efficiency is calculated by braking scoring unit 44 at specified time intervals. This score is called a braking score (braking score). During drive cycle of vehicle, the braking score is calculated sequentially at specified time intervals and stored in RAM 14 B, and used for calculating a total score and a average value of braking score.
Idling Score
[0069] Back to FIG. 2 , idling score calculating unit 41 detects an idling driving condition of a vehicle. When an idling driving is started at the start in one driving cycle, idling driving scoring unit 45 sets an initial value in an idling score. And, idling driving scoring unit 45 , each time when idling driving is detected, gets a timer (not shown) started to measure an elapsed time of the idling driving. And, after a predetermined time is past from a starting of the idling driving, the idle score is decreased by a predetermined value at specified time intervals.
[0070] Here, referring to FIG. 7(A) , a method of decreasing point value of an idling score is described. A driving cycle and an idling drive are started in time t 0 . An initial value is set in an idle score (100 points in this embodiment). The idle score is decremented by a predetermined value at specified time intervals from time point t 1 when a predetermined time (for example, one minute) has been past from the starting of the idling driving, to time point t 2 when idling driving is finished. Here, preferably, a predetermined time is set so that it is equivalent to a duration of the idling time needed in a stop of a vehicle or waiting at a traffic light or the like, and can be set based on a simulation and a empirical value. Thus, the idle score can be prevented from decreasing about idling drive having an ordinary duration in a stop of the vehicle or waiting at a traffic light or the like. As the idle driving over a predetermined time, for example, a parking or the like for some sort of business can be thought, so, the longer the duration of an idling time, the lower the value of an idle score is.
[0071] The value of an idle score at the time point t 2 when the idling drive is finished, for example, is stored and maintained in the memory of controller 40 . Again, if an idling drive starts at the time point t 3 , the value of an idle score (or, the value of an idle score at the time point t 2 ) maintained in the memory of controller 40 is read out at the time point t 4 when the predetermined time has been past from the start. And, the idle score is decremented by a predetermined value at specified time intervals until the time point t 5 when the idling drive is finished. Thus, during one driving cycle, the idle score is decreased according to the duration of the idle score.
[0072] Thus, every time an idling is performed, an idle score evaluated an idle operation from the view point of fuel efficiency is calculated by idle operation unit 45 . An idle score is calculated sequentially at specified time intervals and stored in RAM 14 B during a driving of a vehicle (during a driving cycle), and used for calculating a total score and an average score of an idle score.
A Calculation of an Average Score
[0073] Back to FIG. 2 , accumulation unit 47 accumulates the accelerator score, the brake score, and the idle score calculated as described above at specified time intervals. The accumulation, in this embodiment, is performed in every one drive cycle from the start of the engine to the stopping of the engine (or from an ignition ON to the ignition OFF).
[0074] In average score calculating unit 48 , each of the accumulated values of the scores of the described three scores accumulated by accumulation unit 47 is divided depending on an elapsed time of the corresponding operation respectively. And, average score calculating unit 48 sequentially calculates each of average values of the described three scores respectively. At the same time as this, a sum of these three scores is accumulated similarly and is divided depending on an elapsed time, and a total score is calculated sequentially. Thus, average values of the three individual values and a total score which are calculated sequentially depending on an elapsed time, are stored in RAM 14 B. When a driving cycle is finished by turning OFF an ignition key, the average values of the three individual values and the total score which are stored in RAM 14 B, are stored in nonvolatile memory 14 D as a accelerator score, a brake score, an idle score, and a total score, representing this driving cycle.
[0075] Here, referring to FIG. 8 , on time point t 0 , a driving cycle is started by turning ON an ignition key. An idling drive starts with the start of the driving cycle. An initial value (for example, 100 points) is set in an idle score. The idle score is decremented, according to an elapsed time after a predetermined time has been past after the start of the idling drive, as described referring to FIG. 7(A) . The idling drive is finished on time point t 1 , and, when an accelerator pedal is depressed, a vehicle speed gets higher. During an accelerator operation, an accelerator score is calculated at specified time intervals as described above. On time point t 2 , the accelerator operation is finished, and a pressing on a brake pedal is started. During a braking operation, a braking score is calculated at specified time intervals. The braking operation is finished on time point t 3 , a vehicle speed becomes zero, the vehicle stops, and the idling driving is started again. It is started to decrement the idle score from the last count after the predetermined time has been past. On time point t 4 , the accelerator operation starts again.
[0076] On starting time point of a driving cycle t 0 , an integrated value is zero. The accelerator score, the brake score, the idle score are calculated at each time point from time point t 0 to time point t 11 when a driving cycle is finished, but every time these scores are calculated, the score is added to the previous score and the integrated value of this time is calculated. The integrated value of the drawing illustrates this integration process in an image. The idle score is accumulated from time point t 0 to time point t 1 , this is shown by an region S 1 . The accelerator score is accumulated from time point t 1 to time point t 2 , this is shown by an region S 2 . An accumulation score on time point t 2 is S 1 +S 2 . The brake score is accumulated from time point t 2 to time point t 3 , this is shown by a region S 3 . The accumulation score on time point t 3 is S 1 +S 2 +S 3 .
[0077] Every time the integration process is performed, a total score is calculated by dividing by an elapsed time from the start of the driving cycle t 0 to the present time. For example, the total score at time point t 2 is calculated by (S 1 +S 2 )/(t 2 −t 0 ).
[0078] A total score when one driving cycle is finished is calculated by dividing a total score accumulated by the driving cycle by a length of time Tdc. An embodiment in FIG. 8 , it can be calculated by (S 1 +S 2 + . . . +S 11 )/Tdc. The total score when one driving cycle is finished shows an average fuel condition of this driving cycle. The total score when one driving cycle is finished is stored in nonvolatile memory 14 D of the controller 40 .
[0079] Average score calculation unit 48 calculates average values of three individual values with the same timing with calculating a total score. And that is, an integration score about an accelerator score is calculated, and an average value is calculated by dividing the integration score by an accelerator operation time. For example, when an driving in FIG. 8 is performed, an average of an accelerator scores on a time point t 5 is calculated by (S 2 +S 5 )/((t 2 −t 1 )+(t 5 −t 4 )). Similarly, the calculation of a brake operation and an idling operation are performed, and an average brake score and an average idle score are calculated respectively. About an average idle score, it may be calculated by including the described predetermined time referring to in FIG. 7 (for example, in an embodiment in FIG. 8 , an average idle score on time point t 1 is calculated by S 1 /t 1 ). And it may be calculated without including the described predetermined time (for example, in an embodiment in FIG. 8 , an average idle score on time point t 1 is calculated by S 1 /(t 1 −predetermined time)). These individual average scores with a total score are stored in RAM 14 B.
[0080] The calculation of an average score can be performed at long time intervals relatively, for example in the background of a calculation for an engine control. It is for reducing a load of ECU.
[0000] A Total Score Calculation flow
[0081] FIG. 9 is an embodiment of a flow of a total score calculation process performed by controller 40 . The process to being calculated is performed at specified time intervals (for example, 100 milliseconds).
[0082] In step S 1 , if an ignition switch is ON, this process will be performed. In step S 2 , a condition is detected from an accelerator operation, a brake operation, or an idle operation.
[0083] When the accelerator operation is detected, the map in FIG. 3 is selected (S 3 ), a length of a bar is determined referring to this map based on a detected engine rotational speed NE and a detected throttle opening degree TH (S 4 ). Then, an accelerator score is obtained referring to the map in FIG. 6 (S 5 ).
[0084] In step S 2 , when a brake operation is detected, the map in FIG. 5 is selected (S 6 ), a length of a bar is determined referring to this map based on a detected vehicle speed VP and a detected acceleration DR. Then, brake score is obtained referring to the map in FIG. 6 (S 5 ).
[0085] In step S 2 , when the idling operation is detected, it is determined whether a predetermined time has been past or not after the start of the idling driving this time (S 9 ). If it has not been past, in step S 10 , the value of an idling score at the end of the previous idling driving condition is maintained without change. And, if it has been past, in step S 11 , the idling score is decremented by a predetermined (subtracted) value. The initial value is set in an idle score at the start of a driving cycle.
[0086] In step S 12 , the accelerator score, the brake score, and the idle score which are calculated this time, are added to the previous integrated value, and an integrated value of this time is obtained. In step S 13 , the total score is calculated by dividing the integrated value of this time by an elapsed time after the start of the driving cycle.
[0087] Thus, the total score is calculated at specified time intervals and displayed for the period of the driving cycle. An average score calculated at the end of the driving cycle is stored as a total score in RAM 14 B, a lifetime score is calculated based on this total score.
[0088] A time interval of calculating an accelerator score or the like and a time interval of calculating a total score may be the same, and one may be longer than the other. For example, one may be 100 milliseconds and the other may be 5 minutes.
[0089] A Calculation of a Life Time Score
[0090] A total score shows an average fuel efficiency condition during a driving cycle, a lifetime score is an integrated value of the total scores for multiple driving cycles, and shows technological level of driving operation regarding fuel efficiency.
[0091] Lifetime score calculating unit 49 in FIG. 2 , every time each driving cycle is finished, converts a total score of driving cycle this time to a total score equivalent referring to a map in FIG. 7(B) . This map is preliminarily stored in ROM 14 C of controller 40 . If a total score is more than 50 points, a driving operation regarding a fuel efficiency is good, so the total score will be converted to a total score equivalent having a positive value. If a total score is less than 50 points, the driving operation regarding a fuel efficiency can not be said good, so the total score will be converted to a total score equivalent having a negative value.
[0092] In this embodiment, in the map, a change of a corresponding total score equivalent is small at zero neighborhood, at 50 points neighborhood, and at 100 points neighborhood of a total score. According to this, a total score can be converted to a total score equivalent reflecting technological level of driving operation regarding a fuel efficiency with more precision. A total score equivalent may be changed linearly corresponding to a change of a total score.
[0093] In this embodiment, an absolute value of a maximum value of a total score equivalent (+5 in this embodiment) and an absolute value of a minimum value of a total score equivalent (−5 in this embodiment) are the same, but both may be set to different sizes. For example, an absolute value of a minimum value can be bigger than an absolute value of a maximum value (for example, −10 and +5). A degree of subtraction of a lifetime score is bigger than a degree of addition of a lifetime score, so that it can be a strict evaluation score.
[0094] In this embodiment, a total score equivalent is shown by an integer. Accordingly, if a total score equivalent corresponding to a total score is obtained with a decimal point, for example, an integer can be obtained by rounding. When a total score is counted by every ten points, a total score equivalents may be defined in a table according to total scores of 0, 10, 20, . . . 100 points.
[0095] Lifetime score calculating unit 49 calculates a corrected value by multiplying the total score equivalent obtained in this way by the mileage of the driving cycle this time. It is shown that the longer a mileage, the more experiential amount a driver has. A corrected value can be a value reflecting experience by multiplying a mileage. The corrected value based on the total score equivalent of the driving cycle this time is calculated by multiplying the total score equivalent obtained in the map in FIG. 7(B) by the mileage (km) of the driving cycle this time.
[0096] Preferably, an upper limit should be set on a corrected value based on a total score equivalent calculated in every driving cycle. In this embodiment, 200 points is set as the upper limit of the corrected value.
[0097] Lifetime score calculating unit 49 calculates the lifetime score by adding the corrected value calculated in the driving cycle to the previous value of a lifetime score.
[0098] An initial value of a lifetime score is zero, and the lifetime score is renewed in every driving cycle. The higher a technological level of driving operation regarding a fuel efficiency, the more a value of lifetime score is. A calculated lifetime score stored is stored in nonvolatile memory 14 D.
Advice Messages
[0099] Back to FIG. 2 , a generating of an advice message by third display control unit 53 is described. In this embodiment, controller 40 calculates fuel efficiency (this is called a instantaneous fuel efficiency) with the same timing with calculating a total score. The total scores are calculated at specified time intervals, so the instantaneous fuel efficiency shows fuel efficiency per the time interval. On the other hand, controller 40 calculates an average fuel efficiency by dividing an integrated value of the instantaneous fuel efficiency from a start of a driving cycle this time to the present time by the time length from the start to the present time. An average fuel efficiency and an average score are stored in pairs in RAM 14 B of control unit 14 B.
[0100] Further, controller 40 calculates average values of the above mentioned scores and fuel efficiency (mileage) every five minutes. Specifically, as described with reference to FIG. 9 , every five minute intervals, acceleration scores, brake scores, and idle scores are added respectively, and the added values are divided by the time interval of five minute to produce five minute average values of the scores. Here, it should be noted that five minute interval is used as an example and other time intervals may be used. The five minute average values are stored in RAM 14 B for example.
[0101] From the view point of vehicle speed, the condition of vehicle speed is measured for providing advice to the driver about fuel efficiency. In this embodiment, driving condition detector 41 detects vehicle speed, in each driving cycle, at a predetermined time interval (the same timing as the calculation of accelerator score described above may be OK). A vehicle speed may be detected by using vehicle speed sensor 11 A as one of sensors 65 ( FIG. 2 ). Vehicle speed condition determination unit 54 determines the condition of vehicle speed based on a ratio in a certain driving time where a vehicle speed is within a predetermined range.
[0102] Here, referring to FIG. 10( a ), fuel efficiency, responsive to a vehicle speed, acquired from a simulation or a experiment is indicated. An overly high vehicle speed may decrease the fuel efficiency. A overly low speed may also decrease the fuel efficiency as compared to a moderate vehicle speed. The longer a driving time with overly high vehicle speed or a driving time with overly low vehicle speed are, the worse the fuel efficiency and an average accelerator score are.
[0103] The fuel efficiency responsive to accelerator operation, even if the amount of pressing the accelerator pedal is constant, decreases when the vehicle speed is overly high, and when the amount of pressing the accelerator pedal increases abruptly to produce intensive acceleration. When the vehicle is driven with an overly high speed, the driver should preferably be informed of the fact. As shown in FIG. 10( a ), driving with an overly low speed tends to decrease the fuel efficiency. Thus, the driver should preferably be informed of this fact so that the fuel efficiency may be improved.
[0104] Thus, in this embodiment, a larger time between the driving time at a vehicle speed that is equal to or lower than a low threshold value and the long driving time at a vehicle speed that is equal to or higher than high threshold value is detected. And, an advice is presented to the driver so that such driving is discouraged. According to this, the driver may recognize that the fuel efficiency may decrease due to the vehicle speed.
[0105] Every time a vehicle speed is detected, vehicle speed condition determination unit 54 determines whether the detected vehicle speed is equal to or lower than the low threshold value or the detected vehicle speed is equal to or higher than the high threshold value to provide an advice as described above. In order to determine a ratio of the driving time in an overly low speed to the driving time in an overly high speed from the start of one driving cycle to the past time, vehicle speed condition determination unit 54 counts a frequency wherein vehicle speed lower than the lower threshold value is detected and a frequency wherein vehicle speed higher that the higher threshold value is detected. And, the ratio of frequencies (in terms of percentage) of frequency that the vehicle speed is lower than the low threshold value to the frequency of detecting vehicle speed from the start of a driving cycle to the current time, and the ratio of frequencies (in terms of percentage) of frequency that the vehicle speed is higher than the high threshold value are calculated. This calculation may be performed in the same timing as the calculation of total score described above. The former ration is called a low vehicle speed ratio and the latter ratio is called a high vehicle speed ratio. The values of these ratios are stored in RAM 14 B in association with the total score and stored in nonvolatile memory 14 D at the end of the driving cycle.
[0106] Vehicle speed condition determination unit 54 refers to the map as shown FIG. 10( b ) based on the calculated low speed ratio and high speed ratio, and determines a vehicle condition. This map is stored in ROM 14 C of controller 40 . When a high-speed driving is performed at the speed that is equal to or higher than the higher threshold value in 70 percent of the elapsed time from the start of one driving cycle to the present time, a vehicle speed condition is determined as “high”.
[0107] When a low-speed driving is performed at the speed that is equal to or lower than the low threshold value in 70 percent of the elapsed time from the start of one driving cycle to the present time, the vehicle speed condition is determined as “low”.
[0108] FIG. 11 illustrates a configuration of message table 55 stored in ROM 14 C of controller 40 . Message table 55 stores advice messages according to each value of the driving operation scores for each driving operation. The advice message is a message to present an advice the driver from the view point of the fuel efficiency for driving operations.
[0109] As to an accelerator operation, as shown in (a), an advice message is stored according to a vehicle speed condition and a value of an average accelerator score. In this embodiment, three ranges are provided for the values of average accelerator scores, a low score rage being from 0 point to 29 points, a middle score rage being from 30 points to 69 points, and a high score rage being from 70 points to 100 points. There are three vehicle conditions of “good”, “low”, and “high” in each of the rages. Accordingly, there are at least nine kinds of messages shown by MA 1 -MA 9 as advice messages stored preliminarily.
[0110] As to the brake operation, as shown in FIG. 11( b ), advice messages are stored for the values of average brake scores. There are a low score rage, a middle score rage, and a high score rage according to the values of average brake scores. Accordingly, there are at least three kinds of messages shown by MB 1 -MB 3 as advice messages stored preliminarily.
[0111] As to the idling operation, as shown in FIG. 11( c ), advice messages are stored for the values of average idle scores. In this embodiment, there are a low score rage from 0 point to 49 points and a high score rage from 50 points to 100 points. Accordingly, there are at least two messages shown by M 11 and M 12 as advice messages stored preliminarily.
[0112] Third display control unit 53 displays an advice for a driving operation and information such as scores described above on display device 17 of the navigation apparatus for the vehicle having a navigation apparatus.
Other Data
[0113] Controller 40 calculates for the following items in addition to data described above, and stores them in nonvolatile memory 14 D at the end of a driving cycle. Nonvolatile memory 14 D stores these data described above and the following data of 1) and 2) for the latest five driving cycles. Or, if it exceeds five driving cycles, nonvolatile memory 14 D stores these data in a manner of FIFO (first-in-first-out) and deletes old data.
1) Fuel Consumption and Driving Distance in Urban Area.
[0114] Fuel consumption (cc) and driving distance (m) are provided when a vehicle is driven at the speed that is not greater than 72 km/h. When vehicle speed sensor 11 A indicates 72 km/h, ECU 14 calculates an amount of fuel consumption from a total time when ECU 14 activates an injector (a fuel injector). At the same time, a total of the driving distance at the speed that is equal to or lower than 72 km/h is calculated. A value calculated sequentially is stored in RAM 14 B, and a value at the end of a driving cycle is stored in nonvolatile memory 14 D.
2) Fuel Consumption and Driving Distance in Highway.
[0115] Fuel consumption (cc) and driving distance (m) when the vehicle is driven at a speed higher than 72 km/h. They are calculated by the calculation similar to calculations of the fuel consumption and driving data of 1). A value calculated sequentially is stored in RAM 14 B, and a value at the end of a driving cycle is stored in nonvolatile memory 14 D. Threshold value of 72 km/h is used expediently to distinguish a high speed driving from a medium and low speed driving.
3) ECON Switch
[0116] Frequency of use of ECON switch 15 A, a switch for selecting an eco-drive mode provided in a driver's seat, and a driving time of one driving cycle are stored in nonvolatile memory 14 D, overwriting at the endo of driving cycle to update data. Accordingly, only the latest data is provided to a diagnosis device.
[0117] In the ECO drive mode, idling stop time is extended, an air conditioner is controlled for an energy saving, power and rotation of the engine are suppressed, and vehicle control is performed giving priority to the fuel efficiency.
4) Lifetime Score of the Vehicle
[0118] A lifetime score described above is stored in nonvolatile memory 14 D.
5) An Eco Class of a Vehicle
[0119] The stage of lifetime score is made an eco class of the vehicle.
[0120] Now, referring back to FIG. 1 , a diagnosis with the use of driving data stored as described above is described. When a vehicle is brought in a service shop 16 for diagnosis, a service representative brings a tablet terminal device to a vehicle. The service representative connects a data link connector (DLC) to ECU 14 of the vehicle to read data stored in nonvolatile memory 14 D into a memory of the tablet terminal device. The data is supplied to a personal computer 16 B that is connected. Data to be read for diagnosis of a driving operation by the user are those data shown in table 1 and table 2 described above.
[0121] HDS includes a function to diagnose a malfunction of a vehicle, and performs an ordinary fault diagnosis by reading data needed for diagnosing the malfunction of the vehicle when there is a problem in the vehicle.
[0122] Personal computer 16 B in service shop 16 communicates with a personal computer of a user via the Internet connection. It is possible that the results of evaluation of a driving operation be presented to a personal computer of a user for browsing.
[0123] There is a computer program installed in personal computer 16 B wherein, the computer program compiles data of a driving operation for display on display device 16 D such as LCD, or outputs to printer 16 E. FIG. 12 and FIG. 13 illustrate one embodiment of charts compiled and presented on the screen of display device 16 D.
[0124] Section 241 of FIG. 12 indicates a fuel efficiency (km/l) where an average fuel efficiency for n (an integer of n≦5) driving cycles is indicated in terms of driving distance per a liter of fuel. It also shows driving distance, and a average vehicle speed. Section 243 shows an average fuel consumption (km/l) and driving distance when the vehicle is driven at the speed that is equal to or lower than 72 km/h for n driving cycles. It also shows an average fuel consumption (km/l) and driving distance when the speed is equal to or higher than 72 km/h.
[0125] Section 245 presents respective average values for n driving cycles for the total score, accelerator scores, brake scores, and idling scores. Scores are illustrated by the number of leafs. Section 246 next to section 245 presents a message on the points to be improved having the highest appearance frequency in evaluations of n driving cycles.
[0126] In this embodiment, among accelerator message ID, brake message ID, and idle message ID output from ECU, message having message ID having the highest appearance frequency for n driving cycles (an integer n is not greater than 5) is shown. When the appearance frequencies are equal, “bad message” is displayed preferentially in the order of accelerator, brake, and idling. In the embodiment of FIG. 11 , the message of “Turn ECON ON and idle stop may take place frequently” is shown.
[0127] Thus, by displaying a message of low score preferentially, an advice about a bad driving operation is displayed so that the driver may become aware of driving habits and an improvement.
[0128] But, in this embodiment, for example, a message for a low score that took place only once is not be displayed. A message having high appearance frequency is displayed preferentially. And, when the ratios of the appearance frequencies are equal, operation unit having a significant influence to the fuel efficiency is given priority and a message of a low score is displayed in the case of the same operation part. Thus, it is set to keep away from a nitpicky advice display for a driver who drives well.
[0129] In section 247 , for an eco stage, a life time score is divided into three stages according to scores and a degree of proficiency of driving operation for fuel efficiency saving is displayed by illustration of one or more leaves. Section 248 next to section 247 is illustrated by a circular graph showing a use frequency of an eco mode, which may be used by pushing ECO switch 15 A.
[0130] Section 249 illustrates a line chart where the fuel efficiency in each driving cycle changes for n driving cycles. At the same time, the driving distances in each driving cycle are illustrated by a color fill (hatching in the drawing). A vertical axis on the left side indicates the fuel efficiency and a vertical axis on the right side indicates the driving distances.
[0131] A graph included in section 251 illustrates data in more detail for the fuel efficiency and the vehicle speed illustrated in section 243 . Bar graph with a pale hatching illustrates the fuel efficiency in each driving cycle when the vehicle is driven at a medium and low speed. Bar graph with a dark hatching illustrates the fuel efficiency in each driving cycle when the vehicle is driven at a high speed.
[0132] Section 253 illustrates a driving time of the total in n driving cycles, a total idling time, and an amount of fuel consumption by a total idling. Section 255 illustrates a bar graph where the ratio of the usage of an idling stop is illustrated about a vehicle having automatic idling stop function.
[0133] FIG. 13 is a chart that illustrates specific numbers of details of the data of FIG. 12 . A chart of FIG. 16 is displayed when a user selects it on a personal computer. Section 257 illustrates the data of section 249 of FIG. 12 . Section 259 illustrates the data of section 251 of FIG. 12 by specific numbers. Section 261 displays the data of section 245 and section 253 of FIG. 12 where the data are broken down in details to compare on display in each driving cycle.
[0134] The charts of FIGS. 12 and 13 displayed on a diagnosis screen presents representation of the relationship between the driving operation and the fuel efficiency in each driving cycle of the latest several times (5 times at maximum) so that the user may recognize an incognizant driving habits and tendency in terms of data, and may recognize what to do to achieve better fuel efficiency.
[0135] In a service shop, a diagnosis for confirming no failures may be performed to a customer who visits for diagnosis relative to fuel efficiency. And, a serviceman my give a persuasive advice relative to incognizant driving habits and tendency in driving operation and may give guidance for improvement, by presenting comparative data on driving condition for driving operations.
[0136] As an evaluation for the driving operation may displayed or printed as data, the customer may perceive growth as data record each time the customer get a diagnosis. Thus, the customer is inspired for aspiring for a good driving operation as through it were a game.
[0137] While a specific embodiment of this invention has been described above, the scope of the present invention is not limited to the embodiments described herein. | An apparatus is provided for providing users diagnosis on driving operations in the same manner as diagnosing vehicle failures and for presenting evaluation with supporting data so that users may recognize their driving operations. The apparatus reads out driving data for a plurality of driving cycles from an electronic control unit on board the vehicle. The electronic control unit includes a memory for storing driving data representing fuel efficiency condition of the vehicle in accordance with driving operation by a user in each driving cycle of the vehicle. Charts are produced representing fuel efficiency condition for each driving operation by the user for each driving cycle, based on the read out driving data. The charts are output as comparison results for each one of the driving cycles. | 8 |
PRIORITY CLAIM
[0001] This Utility Patent Application is a Continuation In Part of U.S. Utility patent application Ser. No. 11/438,180, filed on May 22, 2006, which is a Continuation in Part of U.S. Utility patent application Ser. No. 10/823,509 filed on Apr. 12, 2004, which is a Continuation In Part of Ser. No. 10/755,045 filed on Jan. 9, 2004, now abandoned, but which was a Continuation of Ser. No. 09/606,429 filed on Jun. 28, 2000, now U.S. Pat. No. 6,677,606.
CONTRACTUAL ORIGIN OF THE INVENTION
[0002] The United States Government has rights in this invention pursuant to Contract No. W-31-109-ENG-38 between the University of Chicago and Argonne National Laboratory.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a method for interacting biomolecules with inorganic materials, and more specifically, the present invention relates to a method for detecting changes in genetic material and manipulating the genetic material using semiconductors.
[0005] 2. Background of the Invention
[0006] Exceptional electronic, optical, chemical and biological activities stem from materials scaled to nanoscaled dimensions, for example, dimensions ranging in size to less than 1000 nanometers.
[0007] The inventors have previously reported on the synthesis of semi-conductor particles having varied physical morphologies and interesting surface properties and reactivity. These reports are found in N. M. Dimitrijevic, et al., J. Am. Chem. Soc. 2005, 127, pp 1344; Z. V. Saponjic et al., Adv. Mater., 2005, 17, pp 111; T. Rajh, et al., J. Phys. Chem. B, 2002, 106, 10 543; and T. Paunesku et al., Nat. Mater., 2003, 2, 343, all incorporated herein by reference.
[0008] U.S. Pat. No. 6,667,606 B1 awarded to some of the inventors, and incorporated herein by reference, discloses nanoparticle:biomolecule composites exhibiting charge transfer characteristics at various excitation levels. Specifically, hybrid nanocomposites were developed that electronically link titanium dioxide nanoparticles to DNA oligonucleotides. TiO 2 is good for practical applications, because not only does it have photocatalytic properties, but it is also inexpensive, nontoxic, and photostable. Since TiO 2 nanoparticles are photoresponsive, they act as reporters of the electronic properties of the biomolecule.
[0009] Molecular recognition of biomolecules and their site selective bindings have unique applications in the fields of patterning, genome sequencing, and drug affinity studies. DNA oligonucleotides are especially promising because of their inherent programmability features of the nucleic-acid-based recognition system.
[0010] Single Nucleotide Polymorphisms (SNPs) are small changes in one's genetic makeup. They occur when one nucleobase replaces another in a sequence. For humans, SNPs show up in more than 1% of the population. However, most of the time, these mutations do not pose a significant health threat because they do not occur in the “coding sequences”, which compose 3%-5% of a person's DNA. However, when mutations do occur in these coding regions, protein synthesis can be altered, giving rise to higher chances for diseases such as breast cancer.
[0011] SNPs do not directly cause disease, which instead results from a combination of genetic, environmental, and lifestyle factors. However, they do indicate one's susceptibility or resistance to certain diseases and influence the severity and progression of the disease.
[0012] So far, the primary SNP detection protocols include Allele Specific Hybridization, Allele Specific Oligonucleotide Ligation, primer extension, and sequencing. However, these methods are costly, time consuming, and not the most sensitive.
[0013] A need exists in the art for a method to detect nucleotide polymorphisms which provides nearly real-time results. Also, the method should confer a sensitivity to reduce false positives and false negatives to absolute minimums.
SUMMARY OF THE INVENTION
[0014] An object of the present invention is to provide a method for detecting nucleotide sequence anomalies that overcomes many of the disadvantages of the prior art.
[0015] Another object of the present invention is to provide a metal oxide surface between 300 nm and 400 nm long and between 40 nm and 60 nm wide for coupling with organic moieties. A feature of the surface is that it is produced without contaminants or other matter on its surface. An advantage of the invented surface is that it facilitates direct contact with the organic moieties, thereby enhancing electrical communication therebetween.
[0016] Yet another object of the present invention is to provide an electrical switch comprising inorganic metal oxide and organic compounds. A feature of the invention is that the switch is activated when exposed to radiation of a predetermined frequency. An advantage of the invention is that the switch is small enough to be used in situ and in vivo to direct electron flow to targeted tissues.
[0017] Still another object of the present invention is to provide a method for determining the location and/or number of mutations in a nucleotide. A feature of the invention is that the determination is done in a matter of a few seconds. An advantage of the invention is that the relatively longer duration experienced when using conventional analysis methods is truncated.
[0018] Another object of the present invention is to provide a method for detecting the presence of mutations which are the hallmarks of certain diseases. A feature of the invention is the ability to detect a single nitrogenous heterocyclic base anomaly by observing a decrease in conductivity of the nucleic acid strand compared to a nonmutated nucleic acid strand. An advantage of the invention is that it is tailored to detect mutation types, and not just mutation presence.
[0019] Briefly, the invention provides a method for detecting anomalies in genetic material, the method comprising supplying the genetic material; establishing electronic communication between the genetic material and a semi-conductor particle, such as a metal oxide, so as to create a composite; contacting the composite with a first metal ion; and subjecting the contacted composite to energy in an amount and for a time sufficient to reduce the first metal ion to a first elemental metal.
[0020] Also provided is a device for detecting single nucleotide mismatching in genetic material, the device comprising a semiconductor particle; a ligand attached to the particle; the genetic material in electronic communication with the ligand so as to form an organic-inorganic composite; metal ion in electronic communication with the composite; and means for energizing the semiconductor particle for a time sufficient to cause said metal ion to plate on the semiconductor particle.
DESCRIPTION OF THE DRAWING
[0021] The present invention together with the above and other objects and advantages may best be understood from the following detailed description of the embodiment of the invention illustrated in the drawing, wherein:
[0022] FIG. 1 is a schematic diagram of electron flow in a dopamine-semiconductor construct, in accordance with features of the present invention;
[0023] FIG. 2 . is a schematic diagram of electron flow in a DNA-dopamine-semiconductor construct, in accordance with features of the present invention;
[0024] FIG. 3A is a schematic depiction of metal deposition based on proximity of nucleic-acid electron donors to a semiconductor, in accordance with features of the present invention;
[0025] FIG. 3B is a graph depicting dependence of metal deposition based on charge separation distance on a nucleic acid-semiconductor construct, in accordance with features of the present invention;
[0026] FIG. 4A is a photomicrograph-schematic view depicting visual means for determining metal deposition based on number of charge hopping sites on nucleic acid molecules, in accordance with features of the present invention;
[0027] FIG. 4B is a graph showing extent of metal deposition in direct proportion to the number of charge hopping sites on nucleic acid molecules, in accordance with features of the present invention;
[0028] FIG. 4C is a graph showing the relationship of decreasing distance between adenine and thymine moieties on a nucleic acid strand and reduction of ambient metal ions to solid metal, in accordance with features of the present invention;
[0029] FIG. 5A is a photomicrograph depicting metal deposition and lack of metal deposition in the presence of guanine hopping sites in DNA;
[0030] FIG. 5B is a graph depicting metal deposition and lack of metal deposition in the presence of mismatches in DNA; and
[0031] FIG. 6 is a graph depicting the spectra fingerprints relating to the number of oligonucleotides attached to a metal oxide particle, in accordance with features of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] A method to control charge transfer reactions in DNA using semiconductors is provided. The present invention takes advantage of photocatalytic properties of semiconductor particles such as TiO 2 to detect single nucleic acid substitutions in genetic material. The method also can detect base pair anomalies such as mismatches, inasmuch as such mismatches stymie (and usually slow down) charge transfer rates. When mismatches do not exist, the intact base pair(s) facilitates charge hopping along the nucleic acid molecule, thereby increasing charge transfer rates. This enhanced charge hopping or charge transfer along a nucleic acid strand manifests as the construct's ability to reduce metal ions to elemental metal or solid metal alloy. Generally, higher plating of solid metal equates with higher conductance characteristics of the nucleic acid strand. Conversely, lower plating observations or no solid metal formation equates with the presence of mismatches which tend to confer insulative (i.e., nonconductive) characteristics to the effected strand.
[0033] The invention comprises solutions of hybrid nanocomposites (ranging in size from 2 nm to 100 nm) in electrical communication with metal ions. In one embodiment, the hybrid nanocomposites consist of mismatched oligonucleotides linked to TiO2 via dopamine. Solutions of hybrid nanocomposites were illuminated or otherwise subjected to excitation energies, all in the presence of the metal ions. By analyzing the plating or deposition of the ions as elemental metal onto the semiconductors, the inventors determine the presence of specific mismatches. Separately, the construct is capable of inducing site-specific redox chemistry in TiO 2 -bound biological molecules, resulting in biological catalysis. This catalysis is the result of light-induced charge separation within the construct.
[0034] The presence of the mismatches prevents hole transfer from ligand molecules (positioned intermediate the semiconductor and the biological material) to the semiconductor, thereby extending the charge separations of the electron carriers on the hybrid construct. The nanocomposites consist of mismatched oligonucleotides linked to the semiconductor particles via dopamine. The oligonucleotides can be parts of DNA, RNA, and other material containing heterocyclic compounds such as nitrogenous bases, including, but not limited to purine and pyrimidine moieties. Dopamine serves as a conductive ligand.
[0035] In an embodiment of the present invention, a mismatch is defined as when a nucleobase is replaced with other while the change does not occur in the complementary chain of a double helix nucleic acid molecule. In this embodiment, when the change occurs in a single strand (target DNA), the strand is duplexed or otherwise probed with a known sequence (probe DNA) and if the result of the charge transfer behaves differently that expected for fully matched DNA, a mismatch is detected.
[0036] A salient feature of the device and method is the attachment of nucleic acid-based molecules to semiconductor molecules. Below is a protocol for attaching a TiO2 nanoparticle to a DNA oligonucleotide.
DNA/Dopamine/TiO2
Annealing Detail
[0037] As noted supra, the inventors have constructed inorganic-organic modules which enable the vectorial transport of electrons along the module and from one constituent of the module to another in a predetermined direction. The constituents are either covalently or noncovalently linked to each other. The semi-conductor particle which has various electronic ground and excited states, is combined with biological molecules or other organic material to produce the hybrid nanocomposite.
[0038] A ligand is utilized as a linker molecule between the nucleic acid moiety and the semi-conductor particle. Bidentate or tridentate modifiers, of the type discussed in U.S. Pat. No. 6,677,606, and incorporated herein in its entirety, are suitable. For the sake of illustration only, hydroxyl phenyls such as dopamine are utilized as a nucleophillic (i.e. electron donating) linker moiety. The selection of dopamine, the use of specific oligonucleotide structures, reagents and reagent concentrations are recounted here to allow the reader to understand the invented method, repeat the invented method and reproduce the hybrid nanocomposite detector. A myriad of substitutions of the individual parts of the construct are suitable as can be perceived by persons skilled in the chemical arts. For example, suitable bidentate molecules include, but are not limited to, enediol ligands such as dopamine, dihydroxyphenyl acetic acid (DOPAC), and combinations thereof. Other bidentate candidates are selected from the polyols, including, but not limited to, glycerol, polyethylene glycol, and glucose.
Metal Deposition Detail
[0039] FIGS. 1 and 2 provide schematic representations of the invented method. FIG. 1 represents the energy state of the invented hybrid nanocomposite not in the presence of nucleic acid. FIG. 1 shows that absorption of light of a sufficient energy (1.6 eV when TiO 2 modified with dopamine is used) results in the formation of electron/hole pairs. When this energy illuminates, irradiates, or otherwise interacts with TiO 2 , an electron from the highest occupied molecular orbital (HOMO) of dopamine is promoted to the conduction band (highest unoccupied shell) of the metal. Even with metal ions present in solution, no metal deposition on the semiconductor will occur because the attraction between the positively charged hole in the dopamine and the excited electron in the conduction band of the metal is stronger than that electron's attraction to metal ion.
[0040] However, and as depicted in FIG. 2 , when a hybrid nanocomposite is made comprising TiO 2 , dopamine and DNA with a GG base sequence along the same strand of a nucleic acid molecule, metal deposition becomes possible. (While FIG. 2 depicts silver as the metal ion reduced, this is for illustrative purposes only. Other metal candidates include, but are not limited to mercury, copper, gold, alloys thereof and combinations of these metals, including silver.)
[0041] Due to the potential difference and short distance between GG and dopamine through covalent bonding, GG (which has a higher potential energy than dopamine) donates electrons to dopamine. As a result, the positive hole which used to be in the HOMO of dopamine moves to GG, subsequently increasing the distance between the positively charged hole and the excited electron in the conduction band of TiO 2 . (In other words, the absorption of light by inventor-fabricated nanocrystallites results in charge separation, with holes (positive charge) being localized on the distally positioned oligonucleotide.) While the inventors chose guanine-containing sites on genetic material to facilitate site selective photooxidation of DNA (due to the relative ease of oxidation of guanine compared to other nucleobases) other nucleobases are also suitable electron donors.
[0042] One embodiment of the invention is particularly suited to detect a G mismatch, whereby the mismatch results in an absence of guanine and whereby the mismatch is positioned intermediate a distally positioned GG sequence and the ligand molecule. In this embodiment, a hole can not “jump” over the mismatch region to reach the final destination, i.e., the most distal GG hole sink. The inventors have determined that the intermediate G mismatch region imparts an insulative region to the strand, thereby rendering the chain less conductive such that the hole does not reach the sink or final GG trap.
[0043] In one embodiment, decreases of strand conductivity occur when bases are replaced with thymine (T), the most insulating base. Alternatively, an increase of conductivity occurs when T is replaced by cytosine (C). Surprisingly and unexpectedly, the inventors found that the chain is more conductive through a kink formed by mismatch base pairs.
[0044] Ultimately, the separation distance increases to a nonconductive distance such that the electron pair can no longer recombine. As a result, the attraction between the promoted electron and silver ions is greater. Furthermore, due to the potential difference between the conduction band of TiO 2 and Ag+, TiO 2 will donate electrons to the silver ions, reducing them to silver atoms which are dark in color. This is how silver deposition can be detected.
[0045] As GG moves farther away from the dopamine ligand on the DNA oligonucleotide, it becomes harder for the base pair sequence to donate an electron to the HOMO of dopamine. As is depicted in FIG. 3A , with increasing GG distance away from dopamine, and therefore from the semiconductor surface the positively charged hole remains closer to the conduction band of TiO 2 . This increasing distance results in increasing the probability of charge recombination and reducing the amount of silver deposition.
[0046] FIG. 3B shows the decreasing levels of silver deposition directly proportional to the distance of the electron donating GG sequence pair from the dopamine/semi-conductor particle construct. Furthermore, in an embodiment of the invented construct, the hole hopping from dopamine to the most distal GG site is enhanced with the presence of repeating adenine units compared to when the adenine units are separated by thymine.
[0047] FIG. 4 a shows that as G-C hopping sites are introduced in poly AT chain before a GG final hole trapping site, hole hopping becomes more efficient as observed with increased silver deposition. FIG. 4A depicts a visual increase in metal deposition. The inventors have found that the base packing along a nucleic acid strand is more compact with the increased presence of adenine, with a base-to-base distance of 3.3 Angstroms compared to a typical 3.5 Angstrom average distance. Thus, the increased presence of adenine serves as a means for decreasing the distance between base pairs and a means for enhancing strand conductivity.
[0048] FIG. 4B depicts a graphic natural logarithmic relationship between the number of charge transfer or charge hopping sites on a nucleic acid strand and the extent of metal deposition. “N” denotes the number of hopping sites.
[0049] FIG. 4C is a graph depicting the extent of metal deposition in the invented construct compared to the length in angstroms of several joined adenine-thymine couplets on a strand. The ordinate of the graph depicts percentage of excitation photons which are utilized in the plating or deposition process. As such, Φ is the quantum yield of silver deposition defined as number of photons that facilitate metal ion (silver in the figure) reduction. FIG. 5A depicts the separation of G-containing hopping sites by these several A-T couplets. FIG. 4C shows that the longer the length of the A-T strands interposed between the hopping sites, the less metal deposition occurs.
[0050] Introducing G-C hopping sites makes hole hopping more efficient and as a G hopping site is introduced every 15 Å, it becomes as efficient (42%) as in the case that a final GG accepting site is placed 7 Å from the nanoparticle surface.
[0051] When one of the G-C hopping sites is replaced with the G-T mismatch, silver deposition decreases ( FIG. 5A ) allowing for sensitive detection of single C to T DNA sequence variation (Single Nucleotide Polymorphism, SNP).
[0052] BRCA1 and BRCA2 are human breast cancer mutations in chromosome 17 and 13, respectively. Each of them is characterized by 12 SNPs several of them C/T SNP. These SNPs can be detected using metal deposition.
Example
[0053] Generally, genetic material adapted to receive a linker molecule with the aforementioned characteristics is utilized. For example, carboxyl-dT terminated oligonucleotides are suitable. In the laboratory, the inventors supplied the oligonucleotides in a stock solution having a concentration of about 20 μM.
[0054] Before illumination, the amino group of dopamine was linked to 4 different sets of DNA (16-20 nucleotides long) having carboxyl groups at the 5′ end (via the intermediate N-hydroxy-succinimide ester). About 50 μl of oligo stock solution, 450 μl of DMF, 5 mg of TSU (O-(N-succinimidyl)-N,N,N′,N′tetramehtylamonium tetrafluoroorate) and 7 μl of i-PrEtN (N,N′-diisopropyl amine) were combined. The solution was agitated for 6 hours at 4 degrees Celsius. Dialyze 500 μl against 50 ml of 1:1 H2O/DMF three times. Add 200 μl of dioxane, (bubble the solution with nitrogen (use small needle, check the nitrogen flow to go bubble by bubble before you start bubbling DNA solution, or) leave vials open in nitrogen atmosphere for a night). Add 7 μl of i-PrEEtN and dopamine to make 100 μM solution under nitrogen. The solution is incubated 24 hours in the dark and under nitrogen or similar fluid devoid of oxygen. The mixture is then dialyzed four times in room temperature against water under nitrogen (the water should be bubbled with nitrogen before dialysis), and then dried under vacuum. This yields oligonucleotides end-labeled with dopamine. Add 100 μl of TiO2/glycine isopropyl ether in 10 mM buffer.
[0055] Then, DA-DNA was attached to TiO 2. The absorption spectroscopy shown in FIG. 6 provides a means to determine the number of oligonucleotides that are bound to TiO 2. Dopamine serves as a conduit of charge for bases on the DNA, and thus, charge separation is possible for the hybrid nanocomposite. In the spectroscopy, the peak of TiO 2 shifts, and this change is proportional to the number of dopamine particles that are attached to TiO 2 , which indicates how many nucleic acid strands are linked to the dopamine. Though the spectroscopy indicates that the amount of DNA-DA bound to TiO 2 fluctuates (which depends on the accuracy and precision of lab techniques), the spectroscopy shows that binding was consistent, at 2-3 oligonucleotides per semi-conductor particle.
Particle Detail
[0056] Inorganic nanoparticles shaped as spheres, rods, disks, cylinders, pyramids, cubes, multi-apex (i.e., star-like), and other predetermined shapes are suitable semiconductor substrate configurations. Methods for preparing these various shapes are disclosed in U.S. patent application Ser. No. 11/438,180 filed on May 22, 2006, the entirety of which is incorporated herein by reference. Generally the particles range in size from between 2 nanometers and 100 nanometers.
[0057] A myriad of metal oxides are suitable nanoparticle candidates, including, but not limited to TiO 2 , WO 3 , Fe 2 O 3 , ZrO 2 , SnO 2 , VO 2 and combinations thereof.
[0058] Surprisingly and unexpectedly, the inventors found site-specific defects located at the tips of the synthesized rods. Hereinafter referred to as “corner defects”, these anomalies are related to the size and shape of features on the particle.
[0059] The site-specific defects include a deviation from the hexa-coordinated (Octahedral) configuration of the metal atoms in the lattice such that a constraining of the atomic arrangement of the atoms occurs. This confinement occurs within less than 10 atomic layers from the tip of the synthesized particle, resulting in an under-coordinated (i.e., less than the normal Oxygen-atom contingent) atomic character to the TI metal sites. This under-coordinate causes a lengthening of the Ti—Ti distances along the longitudinal axis of the crystal.
[0060] The incompletely coordinated Ti defect sites exhibit a high affinity for oxygen-containing ligands and present the opportunity for chemical attachment and modification. For example, and as more fully disclosed in Saponjic et al., Adv. Mater. 2005, No. 8, pp 965-971 and incorporated herein by reference, oxygen-rich enediol ligands form strongly coupled conjugated structures by repairing the coordination surface via chelation. As a consequence, the intrinsic properties of the semiconductor change and new, hybrid molecular orbitals are generated by mixing the orbitals of chelating ligands and the continuum states of the metal oxides. This results in the red-shift of the absorption compared to unmodified nanocrystallites.
[0061] The electronic “topography” of these conjugated structures can provide a means for directing attachment of the ligands (such as dopamine) to certain portions of the semi-conductor particle. Specifically, the inventors found that the under-coordinated defect sites facilitate direct chemical functionalization and specifically, the Ti—Ti atom positioning in the defect site represents an optimal docking site for the enediol groups of dopamine. As such, the surface tip defect promotes the binding of dopamine exclusively to the tips of the synthesized titanium particle. Two benefits are realized as a result: First, semiconductor particles can be manipulated and connected tip-to-tip to form “chainlike” structures, as noted in the “XXX patent application, referenced supra. The formation of such chainlike structures is found in Dimitrijevic et al., J. Am. Chem. Soc. 2005, 127 pp 1344-1345, heretofore incorporated herein by reference. Thus, plating of semiconductors with a first metal can be confined to one end of a chain, while additional metals can be used in plating other regions of the chain structure.
[0062] Alternatively, tailoring dopamine attachment to a first portion of a single semiconductor particle can result in plating of the semiconductor with a first metal (supplied via a first solution of first metal ion) being confined to that first portion of the semiconductor. Then, a second metal plating operation can be conducted, whereby the partially-plated construct is exposed to a second metal ion solution. Upon exposure to a second round of radiation, unplated regions of the partially plated semiconductor is plated with the second metal.
[0063] This plurality of different metal plating provides a means for optimizing the detection capabilities of the invented hybrid nanocomposite.
[0064] In one embodiment, a TiO 2 particle is provided, having the corner defects discussed supra. The corner defects facilitate covalent bonding with dopamine via a bidentate complex of dopamine OH groups with the under-coordinated TI surface atoms. Upon bonding with dopamine (one titanium atom to two hydroxyl groups on the dopamine), the constrained configuration of the Titanium atoms involved relax to the original octahedral lattice configuration, resulting in the formation of a very stable ligand-to-metal complex, estimated at 25 kcal/mole. This relaxation serves as a means for eliminating surface trapping centers which would otherwise constrain mobile electrons.
[0065] This dopamine preparation of the tips of the Titanium particle facilitates covalent bonding of genetic material such as nucleic acid, DNA, etc., to titanium particle via an intermediately positioned dopamine moiety, via a condensation reaction. Alternatively, dopamine can first be bound to the genetic material form a dopamine-DNA construct, with that construct then bound to the constrained sites of titanium.
[0066] While the invention has been described with reference to details of the illustrated embodiment, these details are not intended to limit the scope of the invention as defined in the appended claims. | A method for detecting anomalies in genetic material is provided, the method comprising supplying the genetic material; establishing electronic communication between the genetic material and a semi-conductor particle so as to create a composite; contacting the composite with a first metal ion; and subjecting the contacted composite to energy in an amount and for a time sufficient to reduce the first metal ion to a first elemental metal. Also provided is a device for detecting single nucleotide mismatching in genetic material, the device comprising a semiconductor particle; a ligand attached to the particle; the genetic material in electronic communication with the ligand so as to form an organic-inorganic composite; metal ion in electronic communication with the composite, such that the metal ion reduces to elemental metal when the semiconductor particle is exposed to radiation of a predetermined energy level. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and device for combining at least two data signals having a first data rate into a single data stream having a second data rate being higher than the first data rate for transmission on a shared medium and vice versa. Particularly, the present invention relates to a method and device for combining 84 T-1 (DS-1) channels of 1.544 Mb/s (megabits per second) each into one STM-1 frame corresponding to 155 Mb/s and 63 E-1 channels of 2.048 Mb/s each or 21 T-2 (DS-2) channels of 6.312 Mb/s each into one STM-1 frame, respectively. However, the concept of the present invention is also applicable for different protocols or other hierarchical levels of the SDH or SONET standard as apparent from the following description.
2. Description of the Related Art
The American National Standards Institute has established a standard for high-speed, multiplexed digital data transmission. This is the “synchronous optical network” standard, henceforth referred to as SONET. The SONET standard specifies optical interfaces, data rates, operation procedures and frame structures for multiplexed digital transmission via fiber optic networks.
The International Telecommunications Union (ITU) has adopted the Interface principles of SONET and recommended a new global transmission standard for high-speed digital data transmission. This standard is the “synchronous digital hierarchy” (SDH).
For an account of the SDH standard, reference should be made to the report 30 entitled “REPORT OF Q.22/15 MEETING” from “STUDY GROUP 15” of the ITU International Telecommunication Standardization Sector, bearing the document number “Temporary Document 62(3/15)” and the date “Geneva, 16-27 May 1994.”
The SDH standard is designed to enable manufacturers to develop telecommunications equipment which:
a) will be interchangeable in all telecommunication networks built around the world to its standard; and which b) is backwards compatible, i.e. can be used with data which is in the older telecommunications formats used in North America, Europe and Japan.
This is achieved by a complex hierarchy of so-called “Containers” (C) and “Virtual Containers” (VC), see FIG. 1 . The container, e.g. C-4, C-3, C-12, etc., are information structures designed to accommodate data traffic with specific transmission rates. The C-4 carries traffic with a base rate of up to 139264 kbit/s, the C-3 container carries either up to 44736 or 34368 kbit/s, etc. The containers are turned into virtual containers by adding Path Overhead information (POH) to it. By procedures defined as multiplexing, mapping, or aligning, data structures are generated which are constitutive to the SDH. These data structures are named “Administrative Unit Groups” (AUG) and “Synchronous Transport Module” (STM). The label of an STM is defined by the number of AUGs it carries: a STM-4 contains for example four AUGs. An AUG contains either one “Administration Unit” (AU) of type AU-4 or three of type AU-3. Referring to the simplest cases, in turn one AU-4 contains one C-4 signal and one AU-3 carries one C-3 signal.
The SDH/SONET data frames, i.e., the STM-N signals, are 125 microseconds long. The amount of data transmitted in each frame depends on the hierarchy level N of the signal. The higher hierarchical levels are transmitted at higher data rates than the basic STM-1 level of approximately 155 Mbit/s. The exact transmission rate is defined as 155.52 Mbit/s. However, here and in the following transmission rates are often denoted by their approximate values. This is, in particular, due to the fact that the exact data transmission rates are distorted by overhead data traffic and idle cell stuffing. The integer N indicates how many times faster the data is transmitted than in the STM-1 level. For example STM-4 denotes a data transmission rate of 622 Mbit/s, whereby each data frame contains four times as many bytes as does a frame of STM-1. The highest defined level is STM-64, which has a data rate of 9.95 Gb/s. Hence, each part of the STM-N signal is broadcast in the same time as the corresponding part of an STM-1 signal, but contains N times as many bytes.
The STM-1 signal, as shown in FIG. 2 , contains an information rectangle of 9 rows with 270 bytes/row corresponding to a SONET/SDH data rate of 155.52 Mbit/s. The first 9 bytes/row represent the “Section Overhead” henceforth SOH. The remaining 261 bytes/row are reserved for the VCs, which in FIG. 1 is a VC-4. The first column of a VC-4 container consists of the “Path Overhead” (POH). The rest is occupied by the payload (a C-4 signal). Several VCs can be concatenated to provide a single transmission channel with a corresponding bandwidth. For example, four VC-4 in a STM-4 signal can be concatenated to form a single data channel with approximately 600 Mbit/s capacity: in this case the four VCs are referred to in the standard terminology as VC-4-4c and the signal as STM-4c.
This flexibility of the SDH standard is partly due to the pointer concept: In SDH, the frames are synchronized, but the VCs within them are not locked to the frames. So the individual containers of the SDH signals do not have to be frame aligned or synchronized amongst each other. A “pointer” is provided in the Section Overhead which indicates the position of the above introduced POH, i.e., the start of a virtual container in the SDH frame. The POH can thus be flexibly positioned at any position in the frame. The multiplexing of information into higher order SDH frames becomes simpler than in the old data standards, and an expensive synchronization buffer is not required in SDH. Similarly, lower order signals can be extracted out of and inserted into the higher order SDH signals without the need to demultiplex the entire signal hierarchy. The pointers are stored in the fourth row of the Section Overhead.
The Section Overhead is further subdivided into: (i) The “Regenerator Section Overhead” or RSOH. This portion contains bytes of information which are used by repeater stations along the route traversed by the SONET/SDH Signal. The Regenerator Section Overhead occupies rows 1-3 of the Section Overhead. (ii) The “Multiplexer Section Overhead” or MSOH. This contains bytes of information used by the multiplexers along the SONET/SDH signal's route. The Multiplexer Section Overhead occupies rows 5-9 of the Section Overhead. These sections of the overhead are assembled and dissembled at different stages during the transmission process. FIG. 2 also shows an exploded view of the MSOH.
In the parallel SONET system, a base signal of 51.84 Mbit/s is used. It is called the Synchronous Transport Signal level 1, henceforth STS-1. This has an information rectangle of 9 rows with 90 bytes/row. The first three bytes/row are the section overhead and the remaining 87 bytes/row are the “synchronous payload envelope”, henceforth SPE. Three of these SPEs fit exactly into one Virtual Container-4. Thus signals in the STS-1 signal format can be mapped into an STM-1 frame. Furthermore, frame aligned STS-1 or STM-1 signals can be multiplexed into higher order STM-N frames.
In general, any lower data rate signal which is combined with other such signals into new data frames of higher rate is referred to as a “tributary” signal. For example in the previous paragraph, the three STS-1 signals which are combined into one STM-1 signal are tributary signals. It may be noted that the scope of the term tributary in this description exceeds the standard definition, as it is also used to describe the inter-level signal mapping in SDH.
The present invention relates to a data processing module for mapping data, i.e. tributaries, into and out of the SDH/SONET formats. The data processing achieved with the present invention concerns in particular the compilation of data which is at relatively low data rates into standard data frames of relatively high data rate, and vice-versa.
U.S. Pat. No. 5,452,307 describes a general data multiplexing system comprising a plurality of data multiplexing buses through which a plurality of low-speed digital signals are collected into, and distributed from, a multiplexer/demultiplexer. In a data multiplexing mode, the low-speed digital signals entered from a plurality of low-speed transmission lines have their signal format converted by respectively corresponding low-speed interface circuits, and the resulting signals are multiplexed in time slots designated within a multiplexed signal of primary level on the up bus line of the corresponding data multiplexing bus, under the controls of respectively corresponding bus control circuits. The high-speed multiplexer collects the primary multiplexed signals on the up bus lines of the plurality of data multiplexing buses, and further multiplexes the collected signals up to a predetermined signal level. Thereafter, it sends the resulting secondary multiplexed signal to a high-speed interface module having a high-speed transmission line interface. The high-speed interface module converts the received secondary multiplexed signal so as to match the interface of a high-speed transmission line, and sends the resulting signal to the high-speed transmission line. In a data demultiplexing mode, the signal of the high-speed transmission line is processed by the high-speed interface module and the high-speed demultiplexer, and the resulting signals are distributed through the down bus lines of the data multiplexing buses so as to send the low-speed digital signals to the low-speed transmission lines.
In M. Stadler et. al., “An Embedded Stack Microprocessor for SDH Telecommunication Applications”, in Proceedings of the IEEE 1998 Custom Integrated Circuits Conference (CICC'98), Santa Clara, Calif., USA, May 11-14, 1998, a microprocessor is disclosed which is integrated on the same die as the complete data path of a SDH Add-Drop Multiplexer (ADM). It handles over 1 Million interrupts per second from 29 asynchronous sources. The multiple asynchronous data sources are each connected either to multiple VC-3 mapping units (also called “mapper”) or to multiple VC-12 mapping units for overhead processing. On one hand, each VC-3 mapping unit is coupled to a TU-3 framing unit (also called “framer”) that also takes care of the pointer processing in order to facilitate the frequency adaption between the asynchronous data sources and the clock rate of the higher hierarchy levels. On the other hand, each VC-12 mapping unit is linked to a TU-12 framing unit that also takes care of the pointer processing in order to facilitate the frequency adaption between the asynchronous data sources and the clock rate of the higher hierarchy levels. Subsequently, all TU-3 and TU-12 framing units are combined into one data stream by a VC-4 mapping unit that itself is linked to a AU-4 framing unit for pointer processing and, thereafter, the data steam reaches a STM-1 framing unit, between each framing or mapping unit a different frequency area being realized.
With the increasing mix of voice and data on SDH/SONET networks there is a huge need for mapping low-speed plesiochronous digital hierarchy (PDH), i.e., a transmission system for voice communication using plesiochronous synchronization, channels into high-speed synchronous digital hierarchy (SDH) frames. This is presently done in a system such as the described above in M. Stadler et. al.
European patent application EP 0 874 487 A2 discloses a method, in which at least two data signals having a first data rate are multiplexed into a single data stream having a second data rate being higher than the first data rate for transmission on a shared medium or vice versa. Supercarrier control signals are generated. A supercarrier transmitter maps the supercarrier data signals and the supercarrier control signals into an output supercarrier signal of a high bit rate, and transmits same over high rate span. However, European patent application EP 0 874 487 A2 does not disclose a detailed solution for offering complete SDH/SONET processing for M low-speed channels in a single line of processing units operating at M times the speed of the low channels without the need of any further buffer in the data path behind the ports. Therefore it is difficult to implement the whole device using one single integrated circuit. Thus, it is a problem to construct the device with all its memories on one and the same chip.
Starting from this, it is an object of the present invention to provide a method and device to more efficiently perform the function of combining at least two data signals having a first data rate into a single data stream having a second data rate being higher than the first data rate for transmission on a shared medium and vice versa.
BRIEF SUMMARY OF THE INVENTION
The foregoing object is achieved by a method and a system as laid out in the independent claims. Further advantageous embodiments of the present invention are described in the sub claims and are taught in the following description.
According to the present invention a method and a device is provided for combining at least two data signals having a first data rate into a single data stream having a second data rate being higher than the first data rate for transmission on a shared medium or vice versa, said device comprises at least one port for receiving said at least two data signals and a port addressing unit for extracting data from the data signals received by said ports, wherein said port addressing unit is configured to place the extracted data at predetermined positions in said single data stream to be transmitted on said shared medium and at least one control data insertion unit is provided for placing control data in said single data stream.
Thus, a method and device proposed implementing a multiplexing structure in which the data from M parallel low-speed channels are multiplexed onto a data bus operating with M times the data rate of the M low-speed channels. A multiple-stage process where, e.g., 28 T-1 (DS-1) channels are re-mapped into one T-3 (DS-3) channel and 3 T-3 (DS-3) channels are then mapped into an STM-1 frame is advantageously avoided. However, it extents beyond simple multiplexing, since according to the present invention the data to be transmitted are fully processed in accordance with the applied protocol, e.g., SDH/SONET, in one go. Hence, the present invention teaches full SDH/SONET processing of the data and not only data multiplexing.
In order to facilitate full processing as aforementioned the data are augmented by additional control data which represent an encoding of the port number on which the corresponding data arrive (multiplex direction) or to which the data must be sent (demultiplex direction). Furthermore, control data such as path overhead information and section overhead information, including regenerator section overhead and multiplexer section overhead, are placed in the data stream. In case the control data are dependent on the data to be transmitted, also called “workload”, the control data insertion unit may be configured to at least partly derive said control data from said data positioned in said data stream.
In a preferred embodiment of the present invention the control data insertion unit is configured to place the extracted data into said single data stream according to a predetermined transmission protocol, such as SONET or SDH. Alternatively or in addition, the port addressing unit may be configured to place the extracted data into said single data stream according to a predetermined transmission protocol, such as SONET or SDH.
By applying the concept of the present invention to, e.g., a multiple low-speed into single high-speed SDH/SONET channel mapper/framer device and method, it is possible to offer complete SDH/SONET processing for M low-speed channels in a single line of processing units operating at M times the speed of the low-speed channels is possible. Advantageously, employing in parallel M such processing lines each at the speed of the low-speed channels can be omitted. The system clock rate has to be sufficient, e.g., for STM-1 speed (or even up to STM-64 speed). Although there is a high number of low-speed channels, e.g., 84, the clock rate is sufficient serving all low-speed channels.
In other words, the present invention provides a method and device which advantageously implements a single data path at STM-1 speed instead of implementing, e.g., 84 parallel data paths at 1.544 Mb/s speed. This reduces manufacturing costs. Furthermore, all portions of the device are accordingly driven by the same system clock.
Each processing unit in the data path is storing the necessary information for data processing in a set of registers identified by the encoded port number. Which each clock cycle the new data is processed according to the information stored for the corresponding port number. The information needed to store is the corresponding overhead bytes in the units which do VC mapping plus a counter which identifies the actual position in the corresponding frame. The storage needed for the overhead bytes for VC-11, VC-12 and VC-2 containers is preferably provided on the same chip without an external memory.
In another preferred embodiment of the present invention, the device further comprises at least one buffer for buffering the data received by said at least one port, whereby, preferably, the at least one buffer is formed by a FIFO. Generally, it is sufficient, to provide a buffer having the capacity of storing two bytes, since in a SDH/SONET environment the data are handled byte-wise. However, it might be advantageous to increase the input buffer in order to use it for pointer generation in accordance with a predetermined transmission protocol, such as SONET or SDH.
In order to provide flexible digital cross-connect and add/drop multiplexing functionality between channels the port addressing unit is preferably configured to extract data from said ports in a predetermined order.
The present invention can be realized in hardware, software, or a combination of hardware and software. Any kind of computer system—or other apparatus adapted for carrying out the methods described herein—is suited. A typical combination of hardware and software could be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which—when loaded in a computer system—is able to carry out these methods.
Computer program means or computer program in the present context meaning any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
The above, as well as additional objectives, features and advantages of the present invention, will be apparent in the following detailed written description.
The novel features of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 shows an overview over the SDH signal hierarchy up to the STM-N signal;
FIG. 2 shows a STM-1 signal with a VC-4 container according to standard provisions;
FIG. 3 shows a device for combining multiple data signals having a first data rate into a single data stream having a second data rate being higher than the first data rate for transmission on a shared medium according to the present invention in form of a multiple T1/E1 to single STM-1 mapper
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 3 , there is depicted a device 100 for combining multiple data signals having a first data rate into a single data stream having a second data rate being higher than the first data rate for transmission on a shared medium according to the present invention in form of a multiple T1/E1 to single STM-1 mapper. Each of said multiple data signals enter the device through ports 102 to 108 . In case that the device also functions in the demultiplex direction, the ports are also used to write data signal back to the respective lines (not shown). For the sake of clarity not all of the ports needed for an implementation as described below are shown. In fact, any number of ports could be used to implement a device in accordance with the concept of the present invention. In the present case, however, a multiple T1/E1 to STM-1 SDH/SONET mapper is shown which allows mapping of 84 T1 (SONET standard, 1.5 Mb/s) or 63 El (SDH standard, 2 Mb/s). The straight lines drawn between ports 104 , 106 and 106 , 108 symbolize the omitted rectangles for the remaining ports.
A data bus 110 connects the ports 102 to 108 with a port addressing unit 112 . On one hand, the port addressing unit 112 communicates over a data link 144 with one or more memory units 116 that are used to temporarily store data received from the ports 102 to 108 . On the other hand, the port addressing unit 112 transmits or receives through line 118 data to or from a TU-11 framer 120 . Subsequently, from the TU-11 framer 120 the data are forwarded to and returned from TUG-2/TUG-3/VC-4 mapper 122 over line 124 , respectively, depending on the mode of operation, multiplex-mode or demultiplex-mode. It is acknowledged that the TUG-2/TUG-3/VC-4 mapper 122 may also be split into a TUG-2 mapper, a TUG-3 mapper and a VC-4 mapper. Likewise, other portions of the described device may be merged into one functional unit. Independently from the functional point of view, the whole device is preferably implemented using one single integrated circuit. The TU-11 framer 120 and the TUG-2/TUG-3/VC-4 mapper 122 function as a data insertion unit in the sense that they apply control data to the data stream to be transmitted.
In the next level the data from the TUG-2/TUG-3/VC-4 mapper 122 are fed into a STM-1 framer 126 through connection 128 . From the STM-1 framer 126 the data stream reaches said shared medium (not shown) for transmitting the data received by the ports or vice versa. The shared medium is, e.g., an optical fibre. Thus the device according to FIG. 1 combines 84 T1 (SONET standard, 1.5 Mb/s) or 63 El (SDH standard, 2 Mb/s) channels into a single VC-4 container and finally an STM-1 (OC-3) frame.
The port addressing unit 112 accesses in read or write mode the ports 102 to 108 one by one in order to get and send data, respectively. The order in which the ports are accessed may be random, however, if it is desired to assign the same input ports in a multiplexing mode to identical output ports in demultiplexing mode, the order in which the different channels are multiplexed need to be identical to the order of demultiplexing. In case one channel is meant to be directed from one port onto another port the order of the port access in the multiplexing mode and demultiplexing mode needs to differ respectively.
Together with a STM-1 to STM-64 (OC-3 to OC-192) framer according to the SDH/SONET standard the device according to the present invention can be used to enable STM-64 (OC-192) frame handling with a channelization down to T1 level, including digital cross-connect and add/drop multiplexing functionality between all channels. The mapper is advantageously implemented using a data multiplexing or context switching architecture.
The data path width for the mapper is chosen as 1 byte. The units for VC-11/VC-12 framing and TU-11/TU-12 processing are designed in the data multiplexing or context switching architecture. Hence, these units work on 1 byte from a single T1/E1 channel at one clock cycle and on a corresponding byte from another T1/E1 channel in the next clock cycle. The corresponding parameters per channel are stored in the memory blocks 116 . The System clock is running at STM-1 rate for a 1 byte data path width. The TUG-2/TUG-3 mapper unit maps these 84 TU-11 or 63 TU-12 frames into 21 TUG-2 frames and these into 3 TUG-3 frames and these finally into a single data stream which is the payload for the VC-4 container. The VC-4 framer maps this data stream into a single VC-4 container and the STM-1 framer maps this into an AU-4 unit and finally into an STM-1 frame. The reverse direction is done accordingly. However, the design of the VC-4 and STM-1 framer units may also be implemented in other than the data multiplexing or context switching architecture.
Pointer processing is required at two points, at the TU-11/TU-12 level and at the AU-4 level. Pointer generation at the AU-4 level may be skipped since any clock rate adaptation is already solved at the TU-11/TU-12 level and the VC-4/STM-1 units are running with the same clock as the TU-11/TU-12 units. Pointer interpretation, however, is needed on both levels since received STM-1 frames with VC-11/VC-12 units may have been created in a very different way by other mappers.
The mapper should have an STM-1 (OC-3) line interface as well as an interface for VC-4 containers directly. The VC-4 interface allows exchange of VC-4 containers in both directions with the planned STM-1 to STM-64 (OC-3 to OC-192) framer and thereby enables mapping of T1/E1 channels into OC-192 frames and digital cross-connect between all channels down to the T1 level.
In the following the conversion from T1/E1 to STM-1 is described. There are two alternatives to realize the 84 T1 or 63 E1 ports. One way is to include 84 or 63 PLLs (Phase Locked Loop) on the chip. A simple serial data stream is received at each port and clock/data recovery is done at each port or each port receives serial data plus recovered clock from the I/O module. An approach to include 63 PLLs on a chip may is known from the aforementioned document written by M. Stadler et. al., in which a corresponding chip is described handling 63 E1 channels in an architecture with 63 parallel VC-12 and TU-12 processing units plus a special embedded stack microprocessor for handling all overhead byte processing.
Each port needs a small FIFO to buffer at least 2 bytes of incoming data. However, it may be better to enlarge the buffer so that the buffering for pointer generation is done with this buffer too. In this case, all the units above the buffer can run with the STM-1 system clock, any frequency adaptation is done within the buffer unit. The inclusion of VC-1 POH and STM-1 SOH bytes (and fixed stuff bytes) into the data stream can then be achieved by using clock cycles which do not read data bytes from the buffer whenever overhead bytes must be inserted. The overhead bytes are then written into these empty spaces in the data sequence. This is possible since the whole system runs with a single clock and clock rate adaptation is done in the port buffer, i.e., the position of all overhead bytes is known in advance.
In a second step, the port addressing unit reads 1 byte of data from each port-buffer in a predefined sequence. Digital cross-connect functionality on VC-11/VC-12 level is achieved by changing this sequence and hence the position of the VC-11/VC-12 in the final VC-4.
Thirdly, after the port addressing unit a frame-byte alignment unit is provided which ensures that each 8-bit portion on the data path is really 1 byte of the corresponding T1/E1 channel.
In a fourth step, in a VC-11/VC-12 overhead processor unit the required VC-1 path overhead bytes (V5, J2, Z6 and Z7) per port are included into the data stream. The VC-12 consists of the VC-1 POH plus 1023 data bits, six justification control bits, two justification opportunity bits, eight overhead communication channel bits, fixed stuff bits and bits reserved for future overhead communication purposes. The VC-11 consists of the VC-1 POH plus 771 data bits, six justification control bits, two justification opportunity bits, eight overhead communication channel bits, fixed stuff bits and bits reserved for future overhead communication purposes. The T1/E1 data can be mapped into the VC-11/VC-12 in an asynchronous mode, a bit-synchronous mode and a byte-synchronous mode.
In a fifth step, the TU-11/TU-12 unit then is responsible for pointer generation according to the buffer filling at receive line rate in respect to the data extraction from the corresponding port-buffer at System clock rate. The TU-11/TU-12 pointer points to the V5 byte of the VC-1 POH. The V5 byte is the first byte of the multiframe.
Next, the TUG-2/TUG-3/VC-4 mapper then maps the incoming byte data stream into 1 VC-4 container which contains 3 TUG-3 frames which each contains 7 TUG-2 frames which each contains either 4 TU-11 units or 3 TU-12 units. The TUG-3 is a 9-row by 86 column structure. 3 TUG-3s are then mapped into the 9-row by 261 column VC-4 with the following sequence of columns
1. VC-4 POH 2. fixed stuff 3. fixed stuff 4. first column of first TUG-3 5. first column of second TUG-3 6. first column of third TUG-3 7. second column of first TUG-3 8. second column of second TUG-3 . . . 259. 86th column of first TUG-3 260. 86th column of second TUG-3 261. 86th column of third TUG-3.
Each TUG-3 starts with 2 columns of fixed stuff followed by the byte-interleaved columns of the 7 TUG-2s it contains. Each TUG-2 consists of the columns of 4 byte-interleaved TU-11 or 3 byte-interleaved TU-12 without additional fixed stuff or overhead bytes. In total, each of the 261 columns of the VC-4 corresponds exactly to a corresponding column of a specific TU-11/TU-12 or to fixed stuff or to VC-4 POH. Hence, by reading 1-byte words from the FIFO buffer of each port in the correct sequence and filling in the required overhead and fixed stuff bytes one arrives at the correct VC-4 without the need for any further buffers in the data path. In principle this could be extended even up to the STM-1 frame. However, since it is desired to have the possibility to send VC-4s to the OC-3 to OC-192 framer and not just complete STM-1 frames, the STM-1 framer unit is kept separated from the TUG-2/TUG-3/VC-4 mapper unit with a buffer between both units.
Finally, the STM-1 framer creates the STM-1 frame from the VC-4 by including the corresponding overhead bytes. No pointer generation is needed here since all frequency adaptation was already done at the TU-11/TU-12 level. Accordingly the AU-4 pointer value will be fixed at zero.
In the following the procedure from STM-1/VC-4 to T1/E1 is described. Firstly, the STM-1 framer has to do AU-4 pointer interpretation and section overhead bytes processing.
In a second step, the VC-4/TUG-3/TUG-2 framer either receives the VC-4 from the STM-1 framer or directly through an external interface to the OC-3 to OC-192 framer. The framer processes the VC-4 POH bytes and forwards all TU-11/TU-12 overhead and data bytes towards the TU-11/TU-12 unit. Fixed stuff and VC-4 POH bytes are not forwarded.
Thirdly, the TU-11/TU-12 unit interprets the TU-11/TU-12 pointer values and forwards the data to the VC-11/VC-12 framer unit.
In a fourth step, the VC-11/VC-12 framer unit processes all VC-11/VC-12 overhead bytes and forwards the data without overhead and fixed stuff bytes/bits to the port addressing unit.
Finally, the port addressing unit sends the data to the corresponding output port buffer.
The arrangement of the TU-12s in a VC-4 is described in FIGS. 7-10 of ITU-T standard recommendation G.707. The arrangement of the TU-11s is given in FIGS. 7-11 of the same standard document. There is a clear correlation between time slots of a VC-4 container and the corresponding TU-11s/TU-12s. If K designates the TUG-3 number (1 to 3), L the TUG-2 number (1 to 7) and M the TU-12 number (1 to 3) or TU-11 number (1 to 4) then the columns of the VC-4 (1 to 261) occupied by TU-12 (K,L,M) are given as
10+( K− 1)+3*( L− 1)+21*( M− 1)+63*( x− 1) for x=1 to 4
and the columns occupied by a TU-11 (K,L,M) are given as
10+( K− 1)+3*( L− 1)+21*( M− 1)+84*( x− 1) for x=1 to 3.
1. VC-4 POH 2. fixed stuff—VC-4 3. fixed stuff—VC-4 4. fixed stuff—first TUG-3 5. fixed stuff—second TUG-3 6. fixed stuff—third TUG-3 7. fixed stuff—first TUG-3 8. fixed stuff—second TUG-3 9. fixed stuff—third TUG-3 10. 1. column oft. TU-11 11. 1. column of 2. TU-11 12. 1. column of 3. TU-11 13. 1. column of 4. TU-11 . . . . . . 93. 1. column of 84. TU-11 94. 2. column of 1. TU-11 . . . . . . 259. 3. column of 82. TU-11 260. 3. column of 83. TU-11 261. 3. column of 84. TU-11
The correlation of the TU-11s with the TUG-3s and TUG-2s is then a bit more complicated but not really relevant. The relation would be:
1. TUG-3-1. TUG-2:1. TU-11, 22. TU-11, 43. TU-11. 64. TU-11 1. TUG-3-2. TUG-2:4. TU-11, 25. TU-11. 46. TU-11, 67. TU-11 1. TUG-3-3. TUG-2:7. TU-11, 28. TU-11. 49. TU-11, 70. TU-11 1. TUG-3-4. TUG-2:10. TU-11, 31. TU-11, 52. TU-11, 73. TU-11 1. TUG-3-5. TUG-2:13. TU-11, 34. TU-11, 55. TU-11, 76. TU-11 1. TUG-3-6. TUG-2:16. TU-11, 37. TU-11, 58. TU-11, 79. TU-11 1. TUG-3-7. TUG-2:19. TU-11, 40. TU-11, 61. TU-11, 82. TU-11 2. TUG-3-1. TUG-2:2. TU-11, 23. TU-11, 44. TU-11, 65. TU-11 2. TUG-3-2. TUG-2:5. TU-11, 26. TU-11, 47. TU-11, 68. TU-11 2. TUG-3-3. TUG-2:8. TU-11, 29. TU-11, 50. TU-11, 71. TU-11 2. TUG-3-4. TUG-2:11. TU-11, 32. TU-11, 53. TU-11, 74. TU-11 2. TUG-3-5. TUG-2:14. TU-11, 35. TU-11, 56. TU-11, 77. TU-11 2. TUG-3-6. TUG-2:17. TU-11, 38. TU-11, 59. TU-11, 80. TU-11 2. TUG-3-7. TUG-2:20. TU-11, 41. TU-11 62. TU-11, 83. TU-11 3. TUG-3-1. TUG-2:3. TU-11, 24. TU-11, 45. TU-11, 66. TU-11 3. TUG-3-2. TUG-2:6. TU-11, 27. TU-11, 48. TU-11, 69. TU-11 3. TUG-3-3. TUG-2:9. TU-11. 30. TU-11. 51. TU-11, 72. TU-11 3. TUG-3-4. TUG-2:12. TU-11, 33. TU-11, 54. TU-11, 75. TU-11 3. TUG-3-5. TUG-2:15. TU-11. 36. TU-11. 57. TU-11, 78. TU-11 3. TUG-3-6. TUG-2:18. TU-11. 39. TU-11 60. TU-11, 81. TU-11 3. TUG-3-7. TUG-2:21. TU-11, 42. TU-11, 63. TU-11, 84. TU-11
A corresponding relation holds in case of 63 TU-12s instead of the 84 TU-11s. | A method and a device for combining at least two data signals having a first data rate into a single data stream having a second data rate higher than the first data rate for transmission on a shared medium or vice versa. The device has at least one port for receiving at least two data signals and a port addressing unit for extracting data from the data signals received by the ports. The port addressing unit is configured to place the extracted data at predetermined positions in the single data stream to be transmitted on the shared medium and at least one control data insertion unit is provided for placing control data in the single data stream. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to a method and apparatus for avoiding potential accidents in water-cooled nuclear reactors.
In the case of coolant loss reactor accidents, relatively large quantities of hydrogen are liberated by radiolytic decomposition of the water and by metal-water reactions. After the start of emergency cooling, hydrogen is only produced by radiolysis. This process proceeds relatively slowly, with the result that the hydrogen concentration in a pressurized water reactor can only reach the dangerous explosion limit of 4 vol % after prolonged periods.
Various methods have already been disclosed to prevent hydrogen and air forming an explosive mixture in the dangerous concentration limits of 4 vol % to 75 vol %, said methods supposedly preventing uncontrolled hydrogen combustion
Thus, boiling water reactors, in which the lower H 2 explosion limit is reached after a significantly shorter time than in the case of pressurized water reactors in the event of coolant loss, are equipped with nitrogen inerting systems. Using these systems, the air present in the containment is replaced by nitrogen to such an extent that the residual oxygen concentration is below the limiting value at which a hydrogen/oxygen explosion (oxyhydrogen explosion) is possible. However, the inerting makes normal reactor operation more complicated.
Another possibility for avoiding an explosive mixture in a reactor containment has been disclosed in U.S. Pat. No. 4,139,603. In this disclosure, a recombination facility in a reactor containment for combining hydrogen and oxygen to form water is described. The essential element of the recombination facility is a bundle of electrically heated rods by means of which the gases flowing therethrough are heated to at least about 620° C. The disadvantage of this facility is to be seen in the fact that a supply of electrical energy has to be ensured in all cases.
German Offenlegungsschrift 2,922,717 (corresponds to EP-B1 0 019 907) describes a method for the recombination of hydrogen enclosed in the containment vessel of a nuclear reactor installation, utilizing a powder which reduces the hydrogen being introduced into the containment vessel using an inert gas. A catalyst which is known per se is used as the powder, with the catalyst powder together with the inert gas being blown predominantly into the upper region of the containment vessel from a storage tank arranged outside the containment vessel.
In addition to the uncertainty of the effectiveness of this catalyst in a reactor atmosphere following an accident, the settling of the fine catalyst powder blown in (Al 2 O 3 powder with a particle size of 20 to 60 μm) in the entire containment must be regarded as a disadvantage.
In catalytic recombination, the originally present oxygen concentration of the containment air is not reduced since the radiolytically produced hydrogen only combines with the corresponding amount of radiolytically liberated oxygen.
The introduction of an easily reducible metal oxide powder for recombining the hydrogen is also known. In this case, however, not even the radiolytically liberated oxygen is recombined. The oxygen partial pressure is further increased by the radiolysis. In addition, the settling of the fine powder particles in the entire interior region of the containment is considered disadvantageous here as well.
Dangerous hydrogen concentrations in part regions of the containment can be prevented by thorough mixing of the containment atmosphere, e.g. by means of blowers and air circulation systems. However, this does not result in inerting.
The known methods aim almost exclusively to reduce the hydrogen concentration. Although, in the catalytic recombination methods, some of the oxygen is also bound, the oxygen partial pressure, during the reaction with radiolytically liberated hydrogen, does not fall below the partial pressure originally present in the containment air.
In the case of the inerting of boiling water reactors, this is achieved by a so-called preinerting. In preinerting, the containment is flushed and filled with nitrogen upon starting or restarting the plant until the Oz concentration has fallen to the specified Oz concentration.
SUMMARY OF THE PRESENT INVENTION
The object on which the invention is based is to keep the oxygen concentration in a nuclear reactor containment following a coolant loss accident so low, even in local areas of the containment, that an oxyhydrogen explosion is avoided with certainty.
By reason of the fact that, according to the method according to the invention, the oxygen concentration is reduced to below a certain critical limit, a hydrogen-oxygen oxyhydrogen explosion is reliably excluded. The reduction of the oxygen concentration in the reactor containment following an accident is accomplished by combustion processes in internal combustion engines, the air being removed from the containment atmosphere or from one or more subcompartments of the latter and the exhaust gas of the internal combustion engine being blown back into the containment or the subcompartments thereof.
Known fuels can be used as fuels for operating the internal combustion engines, with the customary liquid or gaseous fuels, such as, for example, gasoline, diesel oil, alcohol, hydrazide, hydrogen gas, propane etc. preferably being used.
The fuel can be stored or held ready both inside and outside the containment. Preferably, the fuel is held ready outside the reactor containment, from where it is piped to the internal combustion engine or engines. Accordingly, the feed pipe system, appropriately dimensioned and designed for safety, is to be installed from the fuel take-off point to the internal combustion engine. For reasons of redundancy and process engineering, it may be advantageous here to employ a plurality of internal combustion engines. If, therefore, in the text which follows only one internal combustion engine is mentioned, this is always intended to include also the use of a plurality of internal combustion engines.
The internal combustion engine is preferably set up inside the containment since this guarantees that no possibly radioactive air can escape into the environment of the nuclear reactor. However, it is quite possible to arrange the internal combustion engines outside the containment. In this arrangement, suitable measures must be taken to ensure that no radioactive containment air reaches the outside, this being accomplished, for example, by recycling the crankcase ventilator into the containment.
As internal combustion engines, it is possible to use both reciprocating piston engines and rotary piston engines, jet engines or the like. The decisive point is that the combustion process takes place in confined, rigid housings at elevated pressure. A so-called steam generator can also be used, operated with liquid hydrogen and oxygen on the principle of a jet engine. The internal combustion engines can be operated with or without a catalyst.
If the setting of the engine remains the same, the fuel/air mixture becomes increasingly enriched due to the closed circuit of the containment air via the combustion chamber of the engine since a fuel excess establishes itself and the air sucked in from the containment becomes increasingly oxygen-depleted.
In order to ensure that even separate zones, i.e. local areas of the containment air if required, are burnt as rapidly as possible by means of the method according to the invention for the purpose of reducing the proportion of oxygen, it is particularly advantageous if the intake branches to the internal combustion engines and/or the exhaust gas branches open into different regions of the containment.
The operation of, for example, an Otto engine is not only tied to the air ratio λ=1 determined by the combustion equations. It operates within the ignition range both in the rich mixture (fuel excess) and with a lean mixture (air excess). For gasoline, the lower ignition limit is about 1.4 and the upper limit is about 8 vol % of vapor (Dubbel, 12th edition, volume 2, page 173).
In the case of explosive mixtures, the explosion range is broadened by increasing the initial pressure, in particular, the upper explosion limit is shifted to higher values. The explosion range is likewise broadened with increasing temperature, i.e. the higher the temperature of the mixture at ignition, the easier it is for the initiated reaction to propagate (see article by W. Bartknecht entitled "Explosions, Progress and Protective Measures", Springer-Verlag 1980, pages 6 and 7).
As a consequence of the circulation according to the invention of the containment air by the internal combustion engine and of the concomitant decrease in the oxygen concentration of this air sucked in by the internal combustion engine, it may occur that the fuel-air mixture in the internal combustion engine falls below the explosion limit and the internal combustion engine no longer has the ability to function.
In order to maintain the functioning ability of the internal combustion engine in all cases, provision is made according to the invention to feed oxygen in an appropriate quantity to the engine intake branch from outside the reactor containment, in addition to the containment air. Mixture control can here be accomplished, for example, by means of the lambda probe. See in this regard the article by C. Reuber entitled "25 Years of Analytical Sensors", Elektronik Journal, August 1988, page 16.
In this way, the full capacity of the internal combustion engines employed is maintained, enabling these to be used, in a further development of the invention, as additional drive units in the case of accidents, for example, for appropriate machines, such as pumps, blowers for air circulation, etc.
The pump(s) driven by the internal combustion engine can be used, for example, for the borated water supply to the reactor cooling system and/or for afterheat removal. Pumps driven in this way can also be used for the supply of water to a spray system which is employed for pressure relief in the reactor cooling circuit and the containment vessel.
During the combustion of fuels containing hydrogen such as, for example, gasoline, diesel oil, alcohols and hydrogen gas and other gaseous fuels--steam is produced.
2 H.sub.2 +O.sub.2 =2 H.sub.2 O (condensable).
By virtue of the condensation of the steam, the pressure in the containment is reduced and the feeding in of an inert gas, such as, for example, nitrogen, would be necessary for pressure compensation.
During the combustion of carbon and of hydrazide with the oxygen of the containment air, the number of moles of the uncondensable gases does not change:
C+O.sub.2 =CO.sub.2
and N.sub.2 H.sub.4 +O.sub.2 =N.sub.2 +2 H.sub.O (condensable).
The additional supply of oxygen envisaged according to the invention, in order as described to maintain the operation of the internal combustion engine, would, with the additionally required or consumed carbon-containing fuel or hydrazide, cause a pressure build up. However, in the case of fuels containing hydrocarbons, this would remain below 0.06 bar, in particular if a residual oxygen content in the reactor containment were permitted. According to K. Nabert and G. Schon in the publication entitled "Safety-Related Characteristics of Combustible Gases and Vapors", second edition, Deutscher Eichverlag GmbH, Berlin, Federal Republic of Germany,
c maxO 2 - value of hydrogen is as follows:
in CO 2 =5.9 vol % and
in N 2 =5.0 vol %, wherein
c maxO 2 is the maximum concentration of the oxygen content of the air in vol %, relative to the overall mixture of fuel plus air plus inert gas, and is the concentration which the oxygen of the air in the overall mixture must not exceed in order, given an unknown concentration of the fuel and of the respective inert gas, to still just prevent an explosion.
In other words, with a residual oxygen concentration below 5 vol % in the containment atmosphere, an explosion would be reliably avoided.
By closing individual subcompartments of the containment and drawing off the air in these, and by blowing the exhaust gases back into these subcompartments, a partial inerting can also be achieved. It is also possible to combine the method according to the invention with the inerting known per se, for example, by reducing the oxygen concentration in some subcompartments of the containment and carrying out the known inerting, for example, with recombiners, in other subcompartments of the containment, for example, those which are designed as separate chambers. For this purpose, inert gas such as helium or nitrogen can be blown in.
Further features of the invention will be apparent from the following description and drawings, in which exemplary embodiments described below of a facility for carrying out the method according to the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic vertical section through the containment with internal combustion engines arranged in the containment, and
FIG. 2 is a schematic horizontal section through the containment with internal combustion engines arranged outside the containment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The illustrated containment 1 of a nuclear reactor is surrounded by a steel containment shell 1'. In the containment are arranged the reactor and the steam generators, heat exchangers, etc. which are subjected to radioactivity. If a loss of cooling water accident occurs a large quantity of hydrogen is liberated by radiolytic decomposition of the water, there being the risk at 4 vol. % and above of an oxyhydrogen gas explosion and hence the risk of damage to the containment itself. In order to prevent the formation of oxyhydrogen gas, two internal combustion engines 3 and 4, for example, are arranged in the containment. Via their intake branches 5, these internal combustion engines suck in the air from the containment, which, following combustion in the internal combustion engine, emerges into the containment again via the exhaust gas branch 6. Internal combustion engines eligible for consideration are those which are suitable for mixed operation (H 2 / liquid or gaseous fuel), for example, reciprocating piston engines, rotary piston engines, jet engines, steam generators, or the like, in which the combustion process takes place in confined, rigid housings, namely the engine housings of these internal combustion engines, at elevated pressure. As fuels, it is also possible to use gasoline, diesel oil, alcohol, hydrazide, gaseous fuels or the like.
In the arrangement shown schematically in FIG. 2, the internal combustion engines 4a, 4b are situated outside the containment 1, according to the exemplary embodiment, between the outer steel containment shell 1' and the containment 1. The intake branches 5a, 5b and the exhaust gas branches 6a, 6b are passed gastightly through the containment. The internal combustion engines 4a, 4b are provided with protection devices against the escape of radioactive containment air. These can comprise, for example, a crankcase ventilation 9 (internal combustion engine 4a) which opens gastightly into the containment 1. Fuel is fed to the individual internal combustion engines via pipes 16 which are connected to a fuel tank 15.
The internal combustion engine 3 according to FIG. 1 is arranged in a subcompartment of the containment 1 in such a way that its intake branch 5 and its exhaust gas branch 6 are likewise situated in this subcompartment. It can be advantageous to have the branches 5 and 6 open into other subcompartments and/or to provide a plurality of intake and exhaust gas branches, each opening into different subcompartments.
If a plurality of internal combustion engines from the containment 1 and/or from subcompartments of the containment can be drawn off via separate intake and exhaust gas branches 5a, 5b, 6a, 6b, with the exhaust gases similarly being piped into subcompartments of the containment. By virtue of the fact that the intake branches and/or exhaust gas branches open into different subcompartments of the containment 1, the oxygen partial pressure prevailing in these local areas of the containment is lowered rapidly and uniformly by combustion of the air present in this area. The formation of oxyhydrogen gas is thereby counteracted.
To reduce the pollutants introduced into the containment 1 with the exhaust gases, it is advantageous to arrange a catalyst 10 in the exhaust gas branches 6, 6b of the internal combustion engines 4, 4b.
In order to continue to ensure complete combustion in the internal combustion engine as the oxygen partial pressure falls, provision is furthermore made for the feed of extraneous air to the intake branches 5, 5a, 5b on the intake side of the internal combustion engines 3, 4a, 4b, this being possible in the exemplary embodiments shown via pipes 8. The pipes 8 are advantageously connected to oxygen cylinders 7, enabling pure oxygen to be admixed.
It is also possible, in addition to the provision according to the invention of internal combustion engines, for another recombiner to be introduced for inerting, for example, other subcompartments la of the containment 1. The blowing in of an inert gas, such as helium or nitrogen, is advantageous, said gas being fed in via the pipe 12a from a gas cylinder 12.
The feeding of an inert gas into the containment or into subcompartments of the containment into which the intake branches 5, 5a, 5b of the internal combustion engines 3, 4, 4a, 4b open is also advantageous for compensating a vacuum produced. Thus, for example, an inert gas, such as for example nitrogen or helium, is blown in from a gas cylinder 12 via the pipe 12b in order to achieve a pressure compensation.
In an advantageous further development of the method and apparatus according to the invention, the internal combustion engine(s), engine 4 shown in FIG. 1, drives a pump 2 or a set of pumps. Since the internal combustion engines are put into operation in the case of an accident, and by virtue of the feeding in of oxygen, can run trouble free in any operating situation, motive energy is available which can be used for controlling the accident. The intake line 2a of the pump 2 thus driven, or its delivery line 2b, is connected to the reactor cooling system, thus ensuring, for example, the borated water supply to the cooling system. The pump 2 can also be used to ensure the removal of afterheat.
The pump 2 is advantageously used for supplying water to a spray system 11 (FIG. 1). The spray system 11 is inserted in the containment vessel of the reactor for the purpose of pressure relief in the case of an accident. The use of the spray system 11 for cooling the reactor pressure vessel is also appropriate. | Method and apparatus for avoiding potential accidents in water-cooled nuclear reactors of the type having an enclosing containment, due to the formation of an explosive gas mixture in the containment. Air is withdrawn from the containment and fed to at least one internal combustion engine as combustion air for the engine. The exhaust gases created by the internal combustion engine are then recycled back into the containment. The result is the lowering of the oxygen partial pressure in the containment to below the critical limit for oxyhydrogen explosion. | 5 |
FIELD OF THE INVENTION
The present invention relates generally to clips and clamping devices, and more specifically to various embodiments of a clip providing for the securing together of the individual members of a pair of socks, stocking, hose or the like for laundering and/or storage.
BACKGROUND OF THE INVENTION
Even with today's modern automated appliances, time has become more and more precious. One of the more onerous tasks required of the typical household is that of periodic laundry. While automated washers and dryers have simplified this chore, it still requires the sorting of clothing and other washable articles into various types according to color and other properties, and requires further sorting when the laundry is done to place the clean clothing or articles in the proper area. While this part of the chore may be readily accomplished with most clothing articles, it nevertheless requires additional time, and in some cases a fair amount of care is required to sort properly some paired articles which may have a similar appearance between different individual units.
Socks, stocking, and hose and the like are a prime example, as oftentimes such clothing articles tend to be conservatively colored or patterned, and great care must be taken to preclude the mismatching of individual articles. While various devices have been developed to provide for such pairing of socks and the like for laundering and/or storage, they suffer from various deficiencies as will be discussed below.
The need arises for a clip providing for the pairing of socks, stocking, and hose and the like, which clip precludes damage to the sock or other article to which it is secured, or gathering of the fabric thereof. The clip should also be provided in a variety of colors, in order for household members or others to determine readily the clip(s) assigned for their use, and any socks or the like which may be secured thereby. A container may also be provided for the storage of unused clips in a handy place, e.g., adjacent a clothes hamper or the like.
DESCRIPTION OF THE PRIOR ART
U. S. Pat. No. 1,402,153 issued to George B. Dusinberre on Jan. 3, 1922 discloses a Clip formed of two mating and interlocking stampings of sheet material. The relative thinness of the material required for the interlocking portion of the clip requires that the portions be formed of a relatively durable material such as metal, which would not be suitable for the environment of the present invention due to its tendency to rust in moist conditions and to scratch or mar the interior of the washer and dryer drums when placed therein. Moreover, no additional means of improving the grip of the jaws is disclosed, which would likely result in slippage and disengagement from the article held therein during a washing or drying cycle.
U. S. Pat. No. 1,556,127 issued to William A. Pruett on Oct. 6, 1925 discloses a Bait Can Holder formed of relatively thin stamped material. A can is gripped within the device, which can serves as a stop for a lid portion. No means is seen to provide for the secure gripping of a relatively thin, flaccid article by the device, nor for storing any such articles therein.
U.S. Pat. No. 1,625,920 issued to Fred A. Thurman on Apr. 26, 1927 discloses a Box containing a plurality of segments therein and including a lid. The device is arcuate in form, and due to the separate lid, plural divisions therein, and inability to secure to a flat surface (e.g., laundry hamper) is unsuitable for use as a container for the clips of the present invention.
U. S. Pat. No. 3,900,181 issued to Nicholas J. Pitanis on Aug. 19, 1975 discloses a Dual Purpose Sock Holder having a breakaway hanger which may be removed after sale of the article held thereby. Two openings are provided, with plural teeth within each opening providing for the gripping of an article inserted therein. The requirement that an article of clothing inserted therein be drawn over the immovable teeth could result in the snagging or tearing of the article, and the gathering of the fabric within the openings would result in less efficient cleaning of the article(s) contained therein.
U.S. Pat. No. 4,765,335 issued to Ferenc J. Schmidt et al. on Aug. 23, 1988 discloses an Aneurism Clip formed of a single piece of titanium or titanium alloy. The deficiencies of such a metal clip used in the environment of the present invention have been noted above in the discussion of the Dusinberre patent. Moreover, the relatively narrow, rod-like jaws do not appear to provide the distribution of force desirable to preclude crushing of the fabric.
U. S. Pat. No. 4,807,334 issued to Russell 0. Blanchard on February 28, 1989 discloses an Article Hanger Clip having a series of staggered, opposed jaws therein. The lack of directly opposite gripping members appears to limit the amount of grip available for securing articles as they a through the turbulence of washing.
U. S. Pat. No. 4,939,823 issued to Milton L. Klein on Jul. 10, 1990 discloses a Sock Palter And Holder comprising a loop having a pin at one end and a cooperating socket at the opposite end. The article(s) secured thereby are punctured by the pin, and thus damaged, by using the device.
U. S. Pat. No. 5,044,051 issued to Milton L. Klein on Sept. 3, 1991 discloses a Pairer And Holder for Sock Pairs, And A Method Of Pairing And Holding Sock Pairs. The device is very similar to the patentee's '823 patent discussed immediately above.
U.S. Pat. No. Des. 34,560 issued to Frank E. DeLong on May 28, 1901 discloses a Paper Fastener formed of wire and having a relatively narrow engagement between the two jaws. The narrow gripping area provided by the wire elements, as well as the unsuitability of the metal material for use in the environment of the present invention, render the device unsuitable.
U.S. Pat. No. Des. 249,927 issued to Kiyoshi Takahashi et al. on Oct. 17, 1978 discloses a Biased Cup Clamp having a relatively thin gripping a edge between the two jaws, and thus unable to spread the gripping force properly for use with relatively soft, flaccid articles such as stockings and the like.
Finally, U.S. Pat. No. Des. 319,903 issued to Edward L. Barner on Sept. 10, 1991 discloses a Stocking Holder comprising a ring having a series of inwardly pointing projections therein. The fabric material must be gathered and stuffed through the ring and projections, which action would likely result in the snagging or tearing of the material, and inadequate washing and drying thereof.
None of the above noted patents, taken either singly or in combination, are seen to disclose the specific arrangement of concepts disclosed by the present invention.
SUMMARY OF THE INVENTION
By the present invention, an improved clip for the securing of individual socks, stockings, and hose or the like to form a pair thereof for laundering and storage, is disclosed.
Accordingly, one of the objects of the present invention is to provide an improved clip which includes relatively wide jaws providing for the distribution of clamping force to preclude crushing of articles therein, and means providing for the biasing of the jaws together.
Another of the objects of the present invention is to provide an improved clip in which the jaws are disposed at substantially right angles to the handle portion of the clip.
Yet another of the objects of the present invention is to provide an improved clip which includes spring means providing for the biasing of the jaws together.
Still another of the objects of the present invention is to provide an improved clip which includes latching means providing for the biasing of the jaws together.
A further object of the present invention is to provide storage means for such clips.
An additional object of the present invention is to provide an improved clip which is provided in plural colors to provide for ready recognition of a specific clip, and thereby readily identify any socks or the like secured thereto.
Another object of the present invention is to provide an improved clip which is monolithically formed of a single piece of material.
Yet another object of the present invention is to provide an improved clip which is formed of a resilient and pliable material in order to preclude damage to the interior of a laundry appliance.
A final object of the present invention is to provide an improved clip for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purpose.
With these and other objects in view which will more readily appear as the nature of the invention is better understood, the invention consists in the novel combination and arrangement of parts hereinafter more fully described, illustrated and claimed with reference being made to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of the clip of the present invention, showing the ball and socket latching means and identifying coloring.
FIG. 2 is a perspective view of a second embodiment, showing an alternative means of biasing the jaws together.
FIG. 3 is a perspective view of a third embodiment, showing a another alternative latching means and coloring.
FIG. 4 is a side view of a fourth embodiment, showing a latching means related to the embodiment of FIG. 1.
FIG. 5 is a perspective view of a container for the various clips of FIGS. 1 through 4.
Similar reference characters denote corresponding features consistently throughout the several figures of the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now particularly to FIG. 1 of the drawings, the present invention will be seen to relate to a clip 10 providing for the securing together of individual socks to form a matched pair S thereof. Clip 10 of FIG. 1 generally comprises a first and a second arm 12 and 14, joined at their proximal ends by an arcuate spring connecting member 16, serving to bias the two arms 12 and 14 apart from one another. The distal ends of each of the arms 12 and 14 include respective first and second jaws 18 and 20, arranged to be closely adjacent and parallel to one another when the first and second arms 12 and 14 are generally parallel to one another.
Jaws 18 and 20 will be seen to be joined to the distal ends of their respective arms 12 and 14 at the midpoints of the jaws, and to form substantially 90 degree angles with the axes of their respective arms 12 and 14. In other words, each of the jaws 18 and 20 resembles the cross member of a T shape, with the respective arms 12 and 14 forming the stems of the T shapes. Thus, the clip 10 may be suspended from an appropriate support (rod, hook, etc.) by the arcuate connecting portion 16, if desired with the jaws 18 and 20 being disposed substantially horizontally in order to spread the fabric of any material grasped therein to a greater degree, thereby allowing better drying of moist articles, less gathering of the fabric, etc.
The clip 10 of FIG. 1 provides a means for biasing the two jaws 18 and 20 together, comprising a ball and socket arrangement. A securing rod 22 is formed to extend from the inner side of the first arm 12, with a ball 24 formed at the distal end of the securing rod 22. A cooperating socket 26 is formed on the inner side of the second arm 14. The socket includes an outer lip 28 which is slightly smaller in diameter than the ball 24, thus requiring the ball 24 to be urged into the socket 26 past the lip 28, and firmly securing the ball 24 within the socket 26 once engaged, thereby to hold the jaws 18 and 20 in close proximity to one another and grasp firmly any articles interposed therebetween. As the clip 10 is preferably monolithically formed of a resilient material (e.g., plastic) as a single, unitary piece of material including the above components, the socket lip 28 provides sufficient compliance to allow the ball 24 to be forced past the lip 28 and to be retained within the socket 26. The operation may be easily reversed by drawing the two arms 12 and 14 apart, to cause the ball 24 to pop loose from the retaining lip 28, and thereby disengage from the socket 26 and allow the jaws 18 and 20 to be spread to remove or insert articles therebetween.
In addition to the above features, it will be noted that the clip 10 is provided with an identifying colored surface 30 (preferably red, in the case of the clip 10 of FIG. 1, although other colors may be used as desired). By providing different identifying colors for the various clips of the present invention, articles (e.g., sock pairs S) contained therein may be more easily and readily identified by a person sorting the completed laundry. If, for example, one member of the family (e.g., daughter) always uses a red colored clip for his/her socks, then the person sorting the laundry need only gather up all articles secured by red clips, and store them in the daughter's appropriate storage area (dresser drawer, etc.). Other clips may be provided in other colors to facilitate the sorting process.
FIG. 2 discloses a clip 32 comprising an alternative second embodiment of the present invention. Clip 32 includes first and second arms 34 and 36 and a connecting member 38 between the proximal ends thereof, in the manner of the clip 10 of FIG. 1. First and second jaws 40 and 42 extend from the distal ends 44 and 46 respectively of the first and second arms 34 and 36, in the manner of the clip 10 of FIG. 1. As in the case of the clip 10 of FIG. 1, these two arms 34 and 36 are biased apart by the resilient spring action of the connecting member 38. However, each of the distal ends 44 and 46 of the arms 34 and 36 will be seen to have an offset or sinusoidal curve, whereby each of the distal ends 44 and 46 bypasses and crosses by the opposite distal end. Thus, the biasing force provided by the connecting member 38 to urge the arms 34 and 36 apart, serves to urge the crossed distal ends 44 and 46 (and thus the two jaws 40 and 42) together.
In addition to the above construction and features, the facing sides of each of the jaws 40 and 42 include means providing for the secure gripping of an article interposed therebetween, such as the teeth 48 visible on the inner surface of the first jaw 40. Also, as in the case of the clip 10 of FIG. 1, some identifying coloring may be provided (e.g., white, black, etc.). Clip 32 may be used by applying pressure to the two arms 34 and 36 to urge them together, thereby causing the two jaws 40 and 42 to be spread apart due to the crossover provided by the sinusoidal and offset form of the two distal arm ends 44 and 46. The jaws are automatically urged together by the action of the resilient connecting member 38, serving to urge the arms 34 and 36 apart and thus urge the two jaws 40 and 42 together to secure an article or pair of articles therebetween.
FIG. 3 discloses a third embodiment of the present invention, comprising a clip 50. Clip 50 is similar to the clip 10 of FIG. 1, having first and second arms 52 and 54, an arcuate resilient connecting member 56 extending between the proximal arm ends, and first and second jaws 58 and 60 respectively extending from the distal ends of the first and second arms 52 and 54. The connecting member 56 urges the two arms 52 and 54, and thus the jaws 58 and 60 extending therefrom, apart from one another, and accordingly, means is provided to urge the two jaws together. A rod 62 extends from the inner surface of the second arm 54, and includes a flange 64 formed in its distal end. The flange 64 cooperates with a slot 66 formed in the first arm 52, and includes a series of notches 68 therein. The rod 62 is resiliently biased downward, so as to urge the flange 64 on the end thereof downward toward the bottom edge of the slot 66. Thus, one of the notches 68 will be automatically urged downward, due to the resilient nature of the material used, to catch on the bottom edge of the slot 66, thereby to secure the two arms 52 and 54 together as desired. By providing a plurality of notches 68 in the flange 64, the grip of the two jaws 58 and 60 may be selectively adjusted to provide grip for thicker or thinner materials. As in the case of the other embodiments, the two jaws 58 and 60 include gripping means or teeth 70, to provide a more effective grip. The colored surface 72 (e.g., blue) of the clip 50 will be seen to provide for ease of identification of that clip 50, and thus any articles contained therein, in the manner of the coloring provided for the clips of the other embodiments disclosed.
Yet another embodiment is disclosed in FIG. 4 of the drawings. The clip 74 of FIG. 4 is formed in a similar manner to the clip 10 of FIG. 1, and includes first and second arms 76 and 78, an arcuate resilient connecting member 80 serving to bias the two arms 76 and 78 away from one another, and first and second jaws 82 and 84 extending respectively from the distal ends of the first and second arms 76 and 78. The clip 74 also includes means providing for the urging of the two arms 76 and 78 together, comprising an extension 86 formed along the inner side of the first arm 76, with an elongated, generally ovoid protuberance 88 formed on the distal portion thereof. This ovoid protuberance 88 cooperates with a mating socket 90 extending from the inner side of the second arm 78, and having an outer lip 92 serving to capture the protuberance 88 within the socket 90. This arrangement operates in a similar manner to that of the ball and socket of clip 10 of FIG. 1, but the extended length of the ovoid protuberance 88 and cooperating socket 90 and lip 92, provide additional security and strength to secure the two arms 76 and 78 (and thus the jaws 82 and 84) toward one another. The operation of the clip 74 is otherwise the same as that for the clip 10 of FIG. 1, with the possible exception of the greater force which may be needed to secure the protuberance 88 within the socket 90 and to remove the protuberance 88 from the socket 90. The clip 74 may also be shaded or colored for identification purposes, as in the case of the clips 10, 32 and 50 respectively of FIGS. 1, 2, and 3, and the jaws 82 and 84 will be seen to include gripping means or teeth 94 thereon to provide for increased security of articles retained therein, in the manner of the clips of FIGS. 1, 2, and 3.
In addition to the above clips, the present invention also provides for storage means for such clips, comprising an open box 96 having a flange 98 secured to the upper edge of the rear side and extending downward therefrom. The rear side and flange 98 define a gap 100 therebetween, with the gap 100 providing for the securing of the box 96 over the edge of a generally planar surface, such as one wall of a laundry hamper. Thus, the box 96 may be installed accordingly, and one or more of the various embodiments of the clips discussed above placed therein for storage.
When soiled socks, stocking or the like are removed for laundering, one of the clips 10, 32, 50, or 74 having color coding according to the household member assigned that specific color of clip, may be used to secure the two socks or stockings together to form an inseparable pair as they are processed through the laundry. The resilient, relatively pliable and soft plastic material of the clips of the present invention ensure that the interiors of the clothes washer and dryer drums will not be marred during the washing and drying cycles. The generally rounded exterior elements of the clips, such as the resilient arm connecting members, further ensure that no sharp edges will catch on other clothing in the laundry cycle and cause damage to such clothing. When laundering is completed, the person sorting the laundered clothing is able to identify immediately the owner of the particular pair of socks and store the socks as a matched pair in their proper storage area without expending undue time and effort, and ready for use by the owner thereof. The clips may then be placed back in the storage box 96, preferably conveniently located at the laundry hamper, for further use.
It is to be understood that the present invention is not limited to the sole embodiments described above, but encompasses any and all embodiments within the scope of the following claims. | A clip preferably monolithically formed of a single piece of resilient and pliable material (e.g., plastic), provides for the securing together of individual units of stocking, socks, and hose and the like, into their proper pairs for ease of sorting for laundry and storage. The clip provides a gripping force biasing the jaws shut, by means of a spring action in the handle portion or by alternative latching means between the two handle portions, while the jaws are relatively wide to distribute the clamping or gripping forces so as to preclude crushing of the fabric or other pliable material gripped therein. The clip may be provided in a variety of colors, in order that they and any articles gripped therein may be recognized readily, and a storage container which is easily attachable in the laundry area (e.g., to the side of a laundry hamper) may be provided for the storage of the clips when they are not in use. The relatively soft and non-metallic material serves to preclude the scratching, marring or other damage to the interior or a laundry washer or dryer drum while in service. | 8 |
This application is a continuation of application Ser. No. 08/627,326, filed on Apr. 4, 1996 now abandoned, which is a continuation of application Ser. No. 08/364,650, filed on Dec. 27, 1994 now abandoned.
TECHNICAL FIELD
This invention relates to arrangements for provisioning service for a telecommunications customer.
Problem
FIG. 1 is a block diagram illustrating the operation of a typical semi-automatic arrangement for provisioning telecommunication service to a customer. The systems shown in FIG. 1 are available from AT&T Network Systems. The blocks with rounded corners represent centers where human interface is required to move, obtain, or transform information. The rectangular blocks represent automated operation systems. In both cases standard generic names are used to convey the main work accomplished by the area.
Block 1 represents the process whereby a customer discusses telecommunications service with a business representative. As a result of the discussion the business representative fills out a paper form which is passed on to a service order clerk 2 who enters the data in that paper form into a system for use by a service order retrieval distribution center (SORD) 3. In the SORD, checks are made automatically for inconsistencies in the data provided on the service order and these errors may then lead to renegotiation with the original customer, or different assignment of telephone company facilities. In the service order retrieval distribution center, items which require equipment to be ordered either from the warehouse or from a vendor are recognized and an order is transmitted to an equipment order bureau 4 for obtaining the equipment. The SORD acts as the service order data distribution center. Other data in the service order is passed on to the loop maintenance operation system (LMOS) 5 and a service order analysis control (SOAC) bureau 6. The LMOS is connected to a maintenance center (MC) 15, where the installers, central office frame, and maintenance personnel receive information about the service order and perform functions necessary to physically implement service. Errors are sent to the MC for human intervention/resolution.
The service order analysis control (SOAC) bureau 6 communicates with a loop facility assignment control system (LFACS) 7 to assign loop facilities (cable pairs) and a work order number to the customer. SOAC reads the service order and generates assignment requests to the Computer System for Main Frame Operations (COSMOS) 8 and LFACS. SOAC control also communicates with a computer system operations center 8 which generates data for transmission to the network administration center 9 and the main distribution frame control center 10. SOAC communicates with COSMOS to obtain the central office assignment for the service order. The assignment is based on customer class of service, load balance, and capacity. The output is the office equipment number and the work order number. COSMOS also supplies the directory number. Errors are sent to a Network Administration Center (NAC) 9, Frame Control Center (FCC) 10, or Loop Assignment Center (LAC) 11 for human intervention/resolution.
Errors can be detected in analyzing the service order at the loop assignment center, frame control center and the network administration center and any of these errors will eventually require correction hopefully without reinvolvement of the customer. Those errors which may require reinvolvement with a customer should be caught in the original analysis by the service order retrieval distribution bureau. SORD 3 also sends data to the recent change operation system (RCOS) 12 for making changes in the data base of local switch 13. The changes generated by the recent change operation system are analyzed by the recent change memory administration center (RCMAC) 14 to make sure they are valid.
As can be seen from this brief description, a problem of the prior art is that the process is complex and there are many opportunities for error requiring extensive rewording of the service order. It is also slow because of the many manual interventions that are required. Manual intervention by the loop assignment center 11, frame control center 10 and maintenance center 15 is required unless previously dedicated outside plant and office equipment are used. This method of operation also leads to a long delay from the time a customer requests service until the service is actually provided.
Solution
In accordance with the principles of applicants' invention this problem is significantly alleviated and a contribution is made to the art in accordance with a system described, for example, in FIG. 2. FIG. 2 is different from FIG. 1 in that the customer directly provides all information, importantly including a service reference number, to the automatic processing arrangement of the provisioning system. FIG. 2 contains all the blocks of FIG. 1 except for the block representing the service negotiation and the data entry performed by the service order clerk. The operation systems are only used to complete the service order. In the unlikely event a problem is found, the system will default to include error procedures. Instead of the service negotiation and data entry by the service order clerk, the caller (service requester 17) directly enters data into the system via a telephone connection for example to the local switch 13 which switch then provides data via data base control 118 and data base system 120 to the service order retrieval and distribution system. Data is delivered directly to SORD 3 which distributes the service order (and keeps status) to LMOS 5, SOAC 6, and equipment order 4. When the service order is verified SORD 3 sends the service order to RCOS 12 for transmittal to the switch 13.
Since many of the errors are introduced during the service negotiation phase (block 1, FIG. 1) the customer (service requester) is provided with a brochure for describing each service and providing a service reference number for each service available to customers in that region. Part of the data provided by the customer to the service order retrieval distribution bureau 3 via local switch 13 is the service reference number that describes the service.
More generally in accordance with applicants' invention, a customer directly provides data to a service provisioning complex of service bureaus. The data includes a reference number that specifies the type of service requested by the customer. In accordance with one specific embodiment of the invention, the reference number, may specify not only features but type of equipment and type of protocol to be used in interfacing the equipment with the local switch to which the customer is to be connected. Based on this number, the availability and consistency of options specified by the customer can be verified.
The customer may communicate with the switch via a dual tone multifrequency (DTMF) telephone, via a more advanced telephone in which data can be directly specified and transmitted such as an integrated services digital network (ISDN) station and where necessary, via speech (for example, for addresses). Only if the customer is directly connected to the switch when placing the order, can a dial telephone be used. The speech recognition equipment may be used for detecting spelled words.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of a prior art provisioning system for provisioning customer telecommunications service;
FIG. 2 is a block diagram for a provisioning system in accordance with applicants' invention;
FIGS. 3 and 4 are a detailed block diagram illustrating the operation of the invention, with the details of the switching system shown in FIG. 4; and
FIGS. 5A, 5B and 5C are a flow diagram illustrating the method of applicants' invention.
DETAILED DESCRIPTION
FIG. 3 is an architectural block diagram illustrating the operation of the invention with the details of the switching system shown in FIG. 4. The switching system (switch) 101 in this example is a 5ESS®-2000 described in AT&T Technical Journal, Vol. 73, No. 6, pages 28-39, November/December 1994, which switch is an advanced version of the 5ESS® Switch, extensively described in AT&T Technical Journal, Vol. 64, No. 6, part 2, pages 1305-1564, July/August 1985, manufactured by AT&T which has capabilities for switching both voice and data. This switch is adapted, for example, to handle integrated services digital network (ISDN) telephone stations such as telephone station 150. The ISDN telephone station set 150, comprises a handset 151 and display 152. This station set is equipped with an CCITT ISDN Basic Rate Interface (BRI), as described in CCITT Red Book Fascicle III.5 Series 1 Recommendation, and has the capability of handling standard Q.931 interface, as described in CCITT Red Book Fascicle VI.9 Recommendation Q.931. This switch is equipped to deal with station sets served via the basic rate interface (BRI) 162, or as telephone station 125 shows, those station sets served via the primary rate interface (PRI) 126.
The switching system also has the capabilities for dealing with ordinary analog telephones such as telephone station 130 via an analog line 129 or the telephone station 124 equipped, in this case, with an analog display services interface (ADSI) device 127 via an analog line 172. Further, the switching system can support a data link 117 to serve peripheral control devices like data base control 118 connected to a regional data base 120. Also, switching system 101 can support data link 135 to access Service Order Retrieval and Distribution system 136 and data link 139 to access Recent Change Operation System 138 to provide automated testing and implementing of service orders generated by customer requests. Further, switching system 101 can support data link 133 to access other switching systems via the CCS7 network 132 which interfaces switching system 142 serving station set 146 and regional data base 143.
The change required in the switching system to implement the present invention is the addition of a program in the processor 110 of the switch for executing the tasks described in the flow chart of FIG. 5. It is to be understood that depending on circumstances, the information being supplied to the calling customer may come from the local data base 116 or from a data base shared by a plurality of central office switching systems, like the data base control 118 and regional data base system 120. The switch 101 comprises a processor 110 for controlling the switch. The processor 110, in turn, comprises a central processing unit 108, call control 106 for controlling the operations of the central processing unit, and a data store 107 for storing call data. The switch also comprises a local data base system 116, storing data for: (1) customer lines connected to the system, such as the Q.931 equipped customer line 162, (2) interconnecting networks 132, (3) data links, such as data link 133 connected to the system, and (4) data about the data base control 118 connected to the system via data link 117. CPU 108 controls a transaction recorder 113 such as a magnetic tape unit which records usage information associated with services offered in accordance with applicant's invention. CPU 108 can also access a local data base system 116 for supplying data for display or audio prompt at telephone stations connected to switching system 101 or for supplying data or audio prompts in response to requests received from CCS7 network 132 over data link 133. The switch also comprises a voice and data switching network 112 which can be used for transmitting data among processor 110 and data base control 118, and for transmitting voice and data among data links coming into the system, such as data link 133 to CCS7 Network 132, and customer lines such as customer line 162. The CCS7 Network 132 which may include one or more switching systems is used for providing data or voice prompt to station 146 from switch 101.
Regional data base 120 is connected to the data base control 118 via data link 119. Voice and data switching network is 112 is connected to control unit 110 via a control connection 111. The data base control 118 and regional data base 120 are used for gathering provisioning information from the calling customer when requested by the local data base system 116 or externally initiated by the data base control 118 itself.
In this specific embodiment of the present invention, a customer requiring telephone service uses a brochure (Appendix I) to select the desired phone service code number. The corresponding data and equipment required to respond to the customer's request is shown in Table I, discussed hereinafter. The customer requests service by calling a special "free" number such as an 800 number. This call is initiated from the ISDN station set 150 by lifting the handset 151, which sends a Q.931 SETUP message over the BRI line 162 to the switching system 101. This service request is detected by the voice and data switching network 112 and relayed via control connection 111 to call control 106 in processor 110. Call control 106 then sends calling party identification and line status query message 122 to the data base control 118 via the data link 117. The data base control 118 queries the regional data base 120 over the data link 119 and finds the appropriate data message 122 which is sent to the voice and data switching network 112 via data link 117 for delivery to call control 106 via data link 111. Call control 106 places the data message in the Display Field of the appropriate Q.931 message sent to the calling party in response to the service request. The Q.931 protocol limits the maximum length of the Display Field information element to 44 octets.
FIG. 3 also illustrates a number of the types of data messages that are sent for implementing this invention. Data message 121 contains display control information for controlling a display on ISDN station set 150. Similar messages 128 are sent to the ADSI device 127 associated with the analog telephone station 124. Data messages 122 and 123 are query messages to request information from the data base system 120 in the case of data message 122 or from data base system 142 or terminating switching system 141 in the case of data message 123. These query data messages include the calling number and line status. The response is in data messages 121, 128, and 131 which include the response message.
The customer may wish to communicate his/her service request from a telephone that is not connected to switching system 101. In this specific embodiment switching system 101 has been designated as the system to communicate with the service order complex. In that case the customer at telephone 146 who is communicating with switching system 142 communicates through the common channel signaling 7 network 132 over data link 133 with switching system 101 in order to obtain the same kind of provisioning service available to customer at telephone 130 for example who is directly connected to switching system 101.
Data communications with an ISDN telephone are performed through the signaling channel which communicates via the voice and data switching network with CPU 108. Voice input for audio prompts to the customers is provided from announcement system 115. For customers placing their order from analog telephones such as telephone 130 requests are recognized in dual tone multifrequency (DTMF) receiver 114 and special non-numeric data is obtained from that customer using speech recognition unit 109. This unit might be used for example for obtaining an address probably by asking the customer to spell that address.
The service order retrieval and distribution bureau is connected by data link 137 to the recent change operation system for entering recent changes into the local data base system 116 of switching system 110 and is connected by data links to the other operations support system shown in FIGS. 1 and 2 such as the loop maintenance operation system, service order analysis control and through the latter loop facility assignment control system, computer system, loop assignment center and through the computer system, the network administration center and the frame control center.
FIGS. 5A, 5B, and 5C are a flow diagram of the method of one embodiment of the present invention. These figures depict the operation of the customer information and called party identification service arrangement, comprising the calling party station set 150, the switching system 101 and the regional data base control 118. Calls that are treated in accordance with the principles of this invention are called Rapid Accurate Provisioning (RAP) calls. Other calls are given treatment by "normal call processing" signifying treatment in accordance with the normal practices for calls.
FIG. 5 illustrates the actions required to request the provisioning of service. Action block 300 indicates that a customer station from which the request is to be made is initially idle. The customer station goes off hook and call control collects digits for the customer (action block 302). If the customer's line is an ISDN line the process of collecting digits is one of receiving a data message from the caller. If the caller is using an analog telephone then the process of collecting digits is the conventional one of collecting digits one at a time from dial pulse or dual tone multifrequency (DTMF) signaling. The call control program of the switch then performs digit analysis (action block 304). Test 306 then determines whether this is a rapid accurate provisioning service call. If not, then call control performs normal call processing (action block 310). If this is a rapid accurate provisioning call, as determined by the number dialed by the customer, then the call record is duly marked to indicate the type of call (action block 307).
Note that the call may be an originating call, i.e., a call from a customer directly served by the switching system which is performing this analysis, or it may be an incoming call, i.e., a call from a station connected to another switching system wherein the call has been forwarded to a switching system that can serve RAP calls. In the latter case the customer continues to interact with the switch in essentially the same way that a directly connected customer interacts using DTMF or ISDN signaling (dial pulse signals are not carried between switching systems) and the serving switching system will use information obtained by automatic number identification for identifying the telephone station of the caller.
Test 308 then determines whether the caller has a display type telephone. If not then the call control sends the calling customer's telephone number to the data base control (adjunct processor 14) to log the call and initiate voice prompt query system (action block 312). If the customer does have a display then the call control sends the customer telephone number and an identifyer of the type of terminal of the caller to the data base control process to log the call and initiate a display and voice prompt query session (action block 314). In either case the data base control then logs a session for the RAP application and determines the appropriate data query messages to be transmitted to the caller and sends this information to the call control program (action block 316). The call control program then provides data messages if appropriate or prompts to the caller and waits for caller response (action block 318).
If the caller is calling from an ISDN telephone then the queries are sent in Q.931 messages; if the caller is calling from an ADSI (analog display telephone) telephone, the messages to the ADSI telephone are in frequency shift key (FSK) signals and are sent from that telephone by dual tone multifrequency (DTMF) tones. Call control then determines whether the customer wishes to terminate the session, i.e., cancel all requests (test 320). If so, action block 336, described hereinafter, is entered. If the customer does not wish to terminate the session, call control waits for a reply from the customer either in the form of a data message or in the form of DTMF digits or where appropriate in the form of speech detected data. When this has been received call control sends the customer response to the data base control for further processing (action block 322). Data base control then applies the data to the session record which is being established for this call for analysis (action block 324). The data is then analyzed to see if there are any errors (test 326). If so, then the data base control sends an error message response to the previously sent data query message (action block 328) and sends this to call control (action block 318) for a reprompt and re-enters action block 318. If no data errors have been found in test 326 then test 330 is used to determine whether the data is now complete and if not, test 332 is used to find out if the customer wants to end the session. If the customer wants to end the session (test 332) then data base control sends a goodbye message to call control (action block 336) and clears the call record (action block 338) then call control resumes normal call processing (action block 310). If the customer wants to continue (test 332) then data base control sends the next appropriate data query message (action block 334) to call control for data in the appropriate format to send to the customer (action block 318).
If the data is complete (test 330) then data base control matches the RAP service number to predetermined offerings (action block 340) and if the service offering fails (test 342) data base control connects the customer to the service center (action block 343), clears the call (action block 338), and returns to normal call processing (action block 310). If the service offering (action block 340) does not fail (test 342) test 345 determines whether the customer confirms the order. If so, then data base control sends service data to SORD for implementation (action block 344) and provides the customer with a service order number and bids goodbye (action block 348), marks the call record (action block 350), and returns to normal call processing (action block 310). If the customer does not confirm the order, action block 336, previously described, and its subsequent action blocks, are executed.
To illustrate the use of the rapid accurate provisioning service applicants have provided excerpts from a typical customer service guide in Appendix 1 and the corresponding data and services are shown in Table I. The customer service guide is designed to give the customer the information needed to allow the customer to enter service provisioning requests. The introduction provides the customer with the number to call (for example, 1-800-RAP-SERV) and tells the customer what information the customer should be ready to provide. Then for each basic type of service the customer service guide gives a rapid service number used for identifying a basic type of service and the tariff for such service. The examples provided in Appendix 1 are for basic residential service; for a more advanced form of this residential service which includes call waiting; and for basic integrated services digital network (ISDN) voice, packet data, and circuit switched data service.
GLOSSARY
CF--Call Forwarding
CPE--Customer Premises Equipment
CW--Call Waiting
DN--Directory Number
DSL--Digital Subscriber Line
ILEN--Integrated Line Equipment Number of subscriber in switch
ISCN--Integrated Service Circuit Number of subscriber in switch
ISLU--Integrated Service Line Unit of subscriber in switch
LCC--Line Class Code of customer
LCEN--Line Card Equipment Number of subscriber in switch
LEN--Line Equipment Number of subscriber in switch
MW--Multiway calling
PH--Packet Handler for ISDN line
PIC--Preferred Interexchange Carrier
SLE--Subscriber Loop Equipment for connection between subscriber and switch
SPID--Single Point Identifier (for voice and circuit switched data)
TABLE 1__________________________________________________________________________SERVICE PROVIDER EXPANSION TO PROVISIONINGRAPID EXPANDED OFFICE DATASERVICE SERVICE & SERVICE PROVISIONINGNUMBER NAME PARAMETERS__________________________________________________________________________R10001 Analog - Basic DN LEN +LCC *PIC *DP/TT *CPE *PrivacyR10002 Analog - Upgrade DN LEN +LCC *PIC *DP/TT *CPE *Privacy *MW *CFB90001 ISDN DN Basic Voice, LCEN Circuit Switched ILEN Data, Packet +LCC Data PH *PIC *Privacy Circuit Switched Data SPID Packet Switched Data: +No. of Logical Channels +Packet Throughput +Packet Window - Send/Receive +Packet Size - Send/Receive +Voice features +Data features__________________________________________________________________________ *= RAP caller provided added information += Implied by RAP number
Table 1 indicates for each service the name of the service and the data which must be entered into the office data base in order to provide the service to the customer and the data which must be provided to the various service order bureaus in order to order the appropriate equipment and make sure that the appropriate connections are set up for the customer. Data without a footnote mark is basic data which must be supplied if the service of the RAP service order numbers is to be provided. Data with an asterisk is directly implied by the RAP service number. Data with a + sign is provided by the service requester.
For the case of basic analog service these parameters include the following:
1. Directory number: supplied by COSMOS unless there is an arrangement verified through prompts from the RAP system whereby a customer can retain a previous directory number, for example, for an upgrade of service or for a change from service provided by an alternate local exchange carrier.
2. The line equipment number (LEN) is provided by the COSMOS system.
3. The line class code is generated from the RAP service number plus other information provided by the customer in response to prompts.
4. The preferred interexchange carrier is supplied by the customer in response to prompts as indicated by the asterisk.
5. The choice of dial pulse or touch tone service is similarly provided by the customer in response to prompts.
6. Additional customer premises equipment (for example a call answering machine) is requested by the customer in response to prompts.
7. Privacy service wherein the customer's telephone number is not provided to the called party on incoming calling line identification, is requested by the customer in response to prompts.
All of these features are also available for the more advanced analog service which automatically specifies call waiting (CW), and which optionally includes, in addition, multiway calling (MW) and call forwarding (CF), both of which are specifiable by the customer.
For basic voice, packet data, and circuit switched data ISDN service, whose RAP number is B90001, the directory number, line card equipment number, integrated line equipment number must be supplied by the service bureaus. The line class code is imp lied by the RAP number. The customer must provide the preferred interexchange carrier and an indication of whether the privacy is requested. The provisioning of circuit switched data is implied by the RAP number and the SPID for that customer is supplied by the service bureau. In addition, basic voice features and data features for that type of service are implied by the RAP number. For the packet switched data features the RAP number implies the number of logical channels required, the packet throughput, the packet window of the number of packets which may be sent without an acknowledgment and the packet size are all implied from the RAP service number.
Clearly more complex ISDN services may require more input from the caller and will have a larger number of fields supplied by the service bureau or implied by the RAP number.
In order to implement the options implied by the RAP number, the data describing circuit switched data, circuit switched line and packet switched data arrangements must be provided to the office data base.
While in this preferred embodiment one basic number is used to identify a basic type of service, and options within that service are provided by the caller in response to prompts from the RAP provider, an alternative arrangement allows a caller to provide specific digits in the RAP service number to indicate specific options. For example, the third digit could be used to indicate specific combinations of features, for example of call waiting, three way calling, and call forwarding. The preferred embodiment has the advantage that the full flexibility of a computer based prompting system can be used wherein the prompts are tailored to the specific basic service requested by the caller; this is particularly advantageous for an arrangement such as the RAP service in which the typical customer uses the service very infrequently.
Generally, simple options can readily be provided through options offered by an announcement, since customers are likely to understand these options. More complex options or option sets should be provided through a separate RAP service number since a customer could easily become confused and may wish to select conflicting options. Auxiliary RAP numbers can also be described in the RAP brochure and used for offering complex feature sets for a basic service specified by the basic RAP number.
Advantageously, manufacturers of customer premises equipment will be able to specify the RAP code to be used, and the answers to queries for that RAP code. It is desirable to retain the RAP number in one of the service bureau's data base in case a customer encounters trouble. The data base can then be queried and the RAP number compared with the customer's recollection (perhaps aided by the manufacturer's brochure) of the type of service requested. Alternatively and additionally, the RAP number recollected by the customer can be compared with the features implemented for that customer to ensure that the features implied by the RAP number match the service features actually provided to the customer. This guards against inadvertent changes of customer service or mistakes in manual operations to implement the service.
Features implemented through the data bases of an intelligent network can also be specified by the RAP number. For example, a "warm line" service wherein elderly or disabled customers can reach a destination of their choice when they go off-hook can be implemented via a routing data base in the intelligent network. Such service can be specified by a RAP number and will be implemented through both central office features and intelligent network features.
It is to be understood that the above-described procedures are merely illustrative of the principles of the present invention and many variations may be devised by those skilled in the art without departing from the scope of the invention. For example, instead of delivering the customer information and called party identification message for visual display, the process could alternatively relay the information as a voice message.
__________________________________________________________________________APPENDIX I - CUSTOMER SERVICE GUIDE__________________________________________________________________________IntroductionWelcome to the newest and easiest way to order phone service. RapidAccurate Provisioning (RAP)allows you to order phone service in the most informal and comfortableway. Please review thefollowing service offerings and pick the one that best suits your needs.When you find the one rightfor you just call 1-800-RAP-SERV and have the following informationhandy.Your name and billing information (Credit card number).Address for service.Date of service.RAP Service Number.Do you need additional Customer Premises Equipment (e.g.,answering machine)?Do you want rotary or touch-tone service?Do you want privacy? (Don't allow others to obtain your phone number).What Interexchange Long Distance) Carrier do you want?Do you want data service? If so, be prepared to enter speed andprotocol.Remember that if you don't find the exact service you require you cansimply call or visit ourService Bureau during our regular business hours.RAPIDSERVICE SERVICENUMBER DESCRIPTIONR10001 Select this for basic residential single line phone service. The monthly service charge is tariffed as follows: Local Service $9.88 1 Rotary service $0.00 1 touch-tone service $0.73 1 line charge $9.15 Supplemental Line Charge/s $3.50 Monthly Service with Touch-Tone $13.38 (excludes Federal/State tax) Local Usage Service applies as follows No discount 9am-8pm 40% discount 8pm-9am No charge for first 175 minutes. Thereafter a $0.05 per minute charge applies.R10002 Select this for residential single line phone service with call waiting. The monthly service charge is tariffed as follows: Local Service $9.88 1 Rotary service $0.00 1 touch-tone seryice $0.73 1 line charge/s $9.15 1 Call Waiting $2.50 Supplemental Line Charge/s $3.50 Monthly Service with Touch-tone $15.88 (excludes Federal/State tax) Local Usage Service applies as follows: No discount 9am-8pm 40% discount 8pm-9am No charge for first 175 minutes. Thereafter a $0.05 per minute charge applies.B90001 Select this for our most popular small business "work-at-home" ISDN voice and data service. This service comes with two voice channels and a data channel to provide maximum flexibility on a single line. Multiple call appearances provide advanced call waiting and call handling capabilities. The service provides conferencing features, specifically including conference, transfer drop and hold. The monthly service charge is tariffed as follows: Local Service $30.30 1 line charge/s (2 channels) $18.30 1 multiple call appearance/s $3.00 1 conferencing feature $9.00 Supplemental Line Charge/s $3.50 Monthly Service (excludes $33.80 Federal/State tax) Local Usage Service applies as follows: No discount 9am-8pm 40% discount 8pm-9am No charge for first 175 minutes. Thereafter a $0.05 per minute charge applies. Packet Data service applies as follows: 0.25 per minute.__________________________________________________________________________ | A method of provisioning telecommunications service. A caller requesting service is connected to a switching system having prompting capabilities. The caller is prompted to enter a service type indicator selected from a brochure describing available service types. The service order request is automatically processed to determine whether the specified service is available to the caller and whether other data provided by the caller is consistent. Advantageously, a service order can be generated without requiring human intervention beyond the initial entry of data by the service requester. Advantageously, service request data can immediately be verified and data inconsistencies or incomplete data identified and requested of the caller immediately. Advantageously, errors in the process and the delay resulting from such errors are minimized. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical device using a waveguide in optical communications, and more specifically to an optical modulator.
2. Description of the Related Art
FIG. 1A shows the configuration of a conventional Mach-Zehnder modulator.
The modulator includes optical waveguides (A) and (B), and coplanar (CPW) electrodes 10 and 11 . The electrode includes the signal electrode 11 and the ground electrode 10 on both sides of the signal electrode 11 , and an electric polarization inversion area 13 is formed at the central portion. In this portion, an optical waveguide is formed on the +Z plane. A substrate is a Z-cut lithium niobate (LiNbO3), and SiO2 is formed as a buffer layer 12 for suppressing the optical absorption by the electrode between the substrate and the electrode. Although not shown in FIG. 1 , it is preferable to form Si film on SiO 2 to suppress the temperature drift by electric charge held between the buffer layers because of pyroelectric effect.
The optical modulator using an electro-optical crystal such as a LiNbO3 substrate, etc. is formed by providing a metal film on a part of the crystal substrate, forming an optical waveguide by heat diffusion or proton exchange in a benezenecarboxylic acid after patterning, and providing electrodes near the optical waveguide. At this time, to prevent the optical absorption by the electrode, an insulating film such as SiO 2 , etc. as a buffer layer is formed between the electrode and the substrate. Normally, an optical waveguide is formed on the −Z plane of crystal because, for example, when a waveguide is formed on the +Z plane in the LiNbO3 crystal, there is an unstable phenomenon of domain inversion occurring on the surface. Such a phenomenon is well known as described in the non-patent document 1, etc. In this example, the +Z plane is a plane uniquely determined by the crystal having spontaneous electric polarization. The spontaneous electric polarization direction is defined as a Z direction, the plane having a waveguide of an electric polarization inversion area in the example shown in FIG. 1 is a +Z plane, and the non-inversion area is a −Z plane. After forming an optical waveguide on the −Z plane, a strong electric field is applied to the substrate, thereby inverting the electric polarization direction of the −Z plane and obtaining a +Z plane.
When an optical modulator is driven at a high speed, the terminals of a signal electrode and a ground electrode are connected by a resistor to obtain a traveling wave electrode, and a microwave signal is applied from the input side. At this time, the refractive indexes of the parallel waveguides (A) and (B) are changed by an electric field into +Δna and −Δnb respectively, and the phase difference between the parallel waveguides (A) and (B) is changed, thereby outputting an intensity-modulated signal light from an output waveguide. By changing the shape of the section of the electrode, the effective refractive index of a microwave can be controlled, and by adjusting the speed between the light and microwave, a broadband optical response characteristic can be obtained. However, since the absolute values of the electric field to be applied to the parallel waveguides (A) and (B) are different so that Δna<Δnb, a phenomenon (chirp) of changing the wavelength of an output light during the transition from the ON status to the OFF status is generated. To solve this problem, the substrate electric polarization inverted in a part of an area is used. A signal electrode is designed to pass on the waveguide (A) in a non-inversion area, and on the waveguide (B) in an inversion area. In FIG. 7 , when L 1 =L 2 , the light passing the waveguides (A) and (B) respectively change in phase by +Δθs and −Δθg in the non-inversion area, and by +Δθg and −Δθs in the inversion area. The Δθg and Δθs respectively indicates the amount of phase change of the light by the ground electrode 10 and the signal electrode 11 . Therefore, the phases of the light passing the waveguides (A) and (B) change in the Y branch waveguide on the output side respectively by +(Δθs+Δθg) and −(Δθs+Δθg), thereby performing a phase modulation with equal absolute values and inverted signs. Therefore, the wavelength chirp can be set to 0. Additionally, the amount of chirp can be adjusted by changing the ratio between the L 1 and L 2 .
FIG. 1A is a top view of an optical modulator. FIG. 1B is a sectional view along the ling A-A′ of the optical modulator shown in FIG. 1A . Since the electric polarization of a substrate is a non-inversion area, the plane on which the optical waveguides (A) and (B) are provided is the −Z plane. That is, the direction of the +Z plane which is the direction of electric polarization is downward. The buffer layer 12 is provided on the optical waveguides (A) and (B) provided on the substrate, and the ground electrode 10 and the signal electrode 11 are provided on the buffer layer 12 . FIG. 1C is a sectional view along the line B-B′ of the optical modulator shown in FIG. 1A . Since the electric polarization of the substrate in this portion is an inversion area, the plane on which the optical waveguides (A) and (B) are provided is the +Z plane. That is, the direction of the +Z plane as the direction of the electric polarization is upward. The buffer layer 12 is provided on the optical waveguides (A) and (B) provided on the substrate, and the ground electrode 10 and the signal electrode 11 are provided on the buffer layer 12 .
When an optical modulator having the above-mentioned electric polarization inversion structure is used, the +Z plane of the crystal is necessarily used. However, as a result of detailed reliability test, we have found the phenomenon that the operation point of a modulator using the +Z plane greatly changes (changed by several 10V's) by adding a temperature test such as a heat cycle, etc. An operation point of a modulator depends on the phase difference between the parallel waveguides (A) and (B) shown in FIG. 1A , and a shift has a large undesired influence on the transmission characteristic, For a countermeasure against these problems, the techniques described in the patent documents 1 and 2 have been developed.
[Non-patent Document 1] S. Miyazawa, J. Appl. Phys., Vol. 50, No. 7, 1979
[Patent Document 1] Specification of Japanese Patent No. 02873203
[Patent Document 2] Japanese Patent Publication No. H05-078016
However, as an experiment result, the following points have been clearly indicated.
An operation point has changed on the +Z plane.
A change occurs when the +Z plane is used regardless of how performing a producing step.
The problems cannot be solved in the reliability establishing method for the temperature drift of the optical modulator generated by a conventional pyroelectric effect.
The conventional countermeasure against the temperature drift is explained below by referring to FIGS. 2A and 2B .
As shown in FIG. 2A , electric charge is generated on a strong dielectric crystal when a temperature changes. It is referred to as pyroelectric effect. By distributing the electric charge to the buffer layer 12 which is an insulating film asymmetrically about the optical waveguides (A) and (B), the phase asymmetrically changes between the two waveguides by the electric field formed by the electric charge, thereby causing a temperature drift. Thus, a method of symmetrically distributing electric charge by forming a conductive film 15 on the top surface of the buffer layer 12 as shown in FIG. 2B is well known.
However, since the degradation phenomenon found in the above-mentioned experiment cannot be completely solved in the method shown in FIGS. 2A and 2B , a new solving method is demanded.
SUMMARY OF THE INVENTION
The present invention aims at providing an optical device having an electric polarization inversion area and capable of effectively preventing the occurrence of the degradation of performance caused by the feature of an electric polarization inversion area.
The optical device according to the present invention includes: a dielectric substrate having spontaneous electric polarization, and a non-inversion area and an inversion area of the spontaneous electric polarization; an optical waveguide formed over a −Z plane of the non-inversion area and a +Z plane of the inversion area; an electrode formed near the optical waveguide; and a conductive layer provided on the plane covering at least the optical waveguide near the surface of the inversion area.
The present invention can provide an optical device capable of effectively preventing the occurrence of the degradation of performance by a temperature drift although an electric polarization inversion area is included.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A through 1C show the configuration of the conventional Mach-Zehnder modulator;
FIGS. 2A and 2B are explanatory views of a conventional countermeasure against a temperature drift;
FIGS. 3A through 3C show examples of the configurations of the optical modulator according to a mode for embodying the present invention;
FIGS. 4A through 4C show the second examples of the configurations of the optical modulator according to a mode for embodying the present invention;
FIGS. 5A through 5C show the third examples of the configurations of the optical modulator according to a mode for embodying the present invention;
FIGS. 6A through 6C show the fourth examples of the configurations of the optical modulator according to a mode for embodying the present invention;
FIG. 7 shows the fifth examples of the configurations of the optical modulator according to a mode for embodying the present invention; and
FIGS. 8A and 8B show the comparison of the operation point change experiment in the temperature cycle between the conventional modulator and the modulator according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The degradation phenomenon found in the above-mentioned experiment cannot be completely solved by the conventional technology shown in FIG. 2B . Therefore, it is estimated that the electric charge is accumulated in the crystal on the +Z plane, thereby causing a phase change in an optical waveguide portion and then the fluctuation in operation point. It is considered that the problem is caused by the unstable spontaneous electric polarization on the +Z plane. We have devised the method of forming a conductive layer near the surface of the +Z plane to stabilize the spontaneous electric polarization. The basic effect can be obtained from any material of the conductive layer, but it is preferable to have less absorption of light. That is, it is desired that effective means as a conductive layer does not generate an optical loss or change the application efficiency of an electric field. We have devised the method of forming an amorphous layer of the material of the substrate or the material having similar property as a substance that satisfies the conditions. For example, an effective material of the amorphous layer can be, LiNbO3, LiTaO3, BaTiO3, etc.
The effect of leveling the distribution of the electric charge accumulated on the +Z plane, and suppressing the fluctuation of the operation point of an optical modulator is considered to be obtained as follows. That is, when the electric charge is unevenly distributed on the +Z plane, the intensity of the electric field effectively applied to two optical waveguides is different when an electric field is applied from an electrode, thereby indicating different amounts of phase change between the two optical waveguides. As a result, chirp is generated or an operation point is moved. If the distribution of electric charge is uniform, the strength of an effective electric field applied to the two optical waveguides changes at the same level. Therefore, the amount of phase modulation applied by two optical waveguides to light does not relatively change. Therefore, no chirp is generated or an operation point does not move. When the electric charge is accumulated on the +Z plane due to unstable spontaneous electric polarization, an undesired influence can be removed by making the charge distribution homogeneous. If a conductive layer is formed near the surface of the +Z plane, the conductive layer is placed at constant electric potential. Therefore, the electric charge accumulated on the +Z plane is attracted at the constant electric potential of the conductive layer, thereby maintaining the distribution of the electric charge at a constant level. As a result, since the distribution of the electric charge accumulated on the +Z plane is constant, an undesired influence on the operation of an optical modulator can be removed.
The amorphous layer is in an amorphous state with the crystal lattice of the substrate disturbed, the material of the crystal layer is the same but different in characteristic, has no spontaneous electric polarization, and indicates higher conductivity than the crystal layer. We have found as a result of an experiment that the operation point of an optical modulator is stable for a heat cycle by having a very thin amorphous layer (having a thickness of about 5˜1000 Å for which an amorphous layer does not lower the electric field from an electrode, or sufficient modulation can be applied to light) on the +Z plane surface. Additionally, since the amorphous layer has the characteristic similar to that of the substrate, no optical absorption occurs even when it is directly formed on the surface of the substrate, thereby causing a transmission loss. Furthermore, since a desired effect can be expected by forming only a very thin layer, the efficiency of applying an electric field does not change.
FIGS. 3A through 3C show examples of the configuration of the optical modulator according to a mode for embodying the present invention.
The components also shown in FIGS. 1A through 1C are assigned the same reference numerals, and the explanation thereof is omitted here.
The top view in FIG. 3A is similar to that in FIG. 1A , but an amorphous layer is formed between the buffer layer and the substrate on the +Z plane. In the sectional view along the line A-A′ shown in FIG. 3B , since the portion is a non-inversion area of electric polarization, no amorphous layer is provided. Since the portion in the sectional view at the line B-B′ shown in FIG. 3C is an inversion area of electric polarization, an amorphous layer is provided to cover the top surface of the optical waveguides (A) and (B). Although an amorphous layer is provided as the most preferable example in a mode for embodying the present invention, it is only necessary that the layer has conductivity.
An amorphous layer is more effective when it is thicker, but since the amorphous portion has little electro-optic effect, there occurs degradation in modulation efficiency when it is extremely thick. Therefore, according to our experiment, the desired thickness is 5˜1000 Å.
FIGS. 4A through 4C show the second example of the optical modulator according to a mode for embodying the present invention.
The same components also shown in FIGS. 3A through 3C are assigned the same reference numerals, and the explanation thereof is omitted here.
Although an amorphous layer is effective by covering the waveguide portion on the +Z plane, the largest effect can be expected when the entire +Z plane is covered. That is, since the capacity of the amorphous layer as the earthing is larger when the area of the amorphous layer as a conductive layer becomes larger, the capability of leveling the distribution of the electric charge accumulated on the +Z plane becomes larger. Therefore, an amorphous layer is provided to cover the entire surface of the electric polarization inversion area as shown in the sectional view along the line B-B′ in FIG. 4C .
FIGS. 5A through 5C show examples of the third configuration of the optical modulator according to a mode for embodying the present invention.
The same reference numerals are assigned to the components also shown in FIGS. 3A through 3C , and the explanation thereof is omitted here.
A larger effect can be expected by forming a conductive layer 21 on the side of the substrate and is allowed to contact an amorphous layer 20 . That is, the conductive layer 21 and the amorphous layer 20 are incorporated into one unit and functions as the earthing, thereby leveling the distribution of the electric charge generated on the +Z plane on the earthing having a larger capacity, and improving the effect of the present invention. As the conductive layer 21 on the side portion, Si and Ti are excellent because there is no influence on an optical loss. Furthermore, it is preferable that the conductive layer 21 on the side portion is grounded. By grounding the conductive layer 21 , the effect as an earthing can be improved, and by providing the conductive layer 21 on the side portion, the wiring for an earthing can be easily connected.
FIGS. 6A through 6C show examples of the fourth configuration of the optical modulator according to a mode for embodying the present invention.
The components also shown in FIGS. 3A through 3C are assigned the same reference numerals, and the explanation thereof is omitted here.
In the case of an optical modulator of 40 Gbit/s requiring a broad band, the substrate on both sides of the optical waveguide is lowered (ridge groove 23 ) as a ridge structure. The ridge groove 23 is typically formed in the RIE (reactive ion etching) method. The present invention is also effective when an optical modulator of 40 Gbit/s provided with an electric polarization inversion area. As shown in FIGS. 6A and 6C , the amorphous layer 20 is formed on the +Z plane. It is not necessary that the amorphous layer 20 is amorphous, but any conductive layer is acceptable.
FIG. 7 shows an example of the fifth configuration of the optical modulator according to a mode for embodying the present invention.
The components also shown in FIGS. 3A through 3C are assigned the same reference numerals, and the explanation thereof is omitted here.
FIGS. 3A through 6C show examples of the configuration of the Mach-Zehnder modulator. However, since the present invention solves the undesired influence caused by the optical phase change on the +Z plane against a temperature change, the effect works also on the phase modulator. FIG. 7 shows the case where the present invention is applied to the phase modulator. The phase modulator shown in FIG. 7 modulates the optical phase by applying the RF voltage by arranging the electrode directly on an optical waveguide 25 . With the modulator, for example, the technology of leveling the modulation band in the low frequency area by inverting electric polarization in part as shown in FIG. 7 is known. Thus, when a modulation band is leveled in the low frequency area, the transmission efficiency is improved. Therefore, in the phase modulator, the configuration of providing an electric polarization inversion area is used as shown in FIG. 7 .
As a method of forming the amorphous layer 20 , it is also possible to directly forming a layer in a substrate by emitting an electronic beam other than forming it on the surface in the developing method by a sputter. In this case, the inside of the substrate including a waveguide area is an amorphous layer. In this case, the effect of the present invention also works sufficiently.
The present invention can also be effective using a conductive layer instead of an amorphous layer. An example of a conductive layer can be a thin metal film of Ti, Au, Pt, etc. and a transparent conductive film of ITO, ZnO, etc. However, since the conductive films of these types have optical absorption more or less, it is necessary to carefully consider the thickness of a film, etc.
FIGS. 8A and 8B show the comparison of the experiment about the fluctuation of an operation point in the temperature cycle of the modulator between the conventional modulator and the modulator according to the present invention.
FIG. 8A shows the case of the conventional modulator. FIG. 8B shows the case of the modulator according to the present invention.
The temperature cycle shows a change in operation point for a change in temperature when the temperature cycle of 100 cycles at −5° C.˜80° C. The conventional modulator and the modulator according to the present invention are formed in the same process and structure other than the thickness of the amorphous layer of 100 Å, but the present invention indicates an outstanding characteristic. That is, the fluctuation of an operation point of about 8V occurs in the conventional technology while the fluctuation of an operation point of less than 1V occurs in the present invention.
The configuration according to the mode for embodying the present invention can also be used with the conventional configuration shown in FIG. 2B , and can expect a larger effect. | Optical waveguides (A) and (B) of a Mach-Zehnder modulator is normally formed on a −Z plane as an electric polarization non-inversion area. However, when the signal electrode 11 and the ground electrode 10 are provided asymmetrically on two waveguides, chirp occurs in output light, which is undesired. Therefore, these electrodes are provided symmetrically about the two waveguides. To effectively perform optical modulation, a part of the substrate in which an optical waveguide exists is to be electric polarization-inverted. As a result of the electric polarization inversion the optical waveguide is on the +Z plane. However, electric charge is accumulated on the +Z plane from unstable spontaneous electric polarization of an electric polarization inversion area, and has undesired influence on the performance of the optical modulator. Therefore, a conductive amorphous layer is formed on the surface of the electric polarization inversion area. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the art of sanitary plumbing systems and more particularly to a novel and improved vacuum flush water closet.
2. Description of the Relevant Art
Vacuum flush sewage systems have been provided heretofore, but they have inherent disadvantages. Some disadvantages of some prior art vacuum flush water closets are that they are expensive, large size, complex and, to varying degrees, difficult to service. Another disadvantage of the prior art vacuum flush water closets is that, they incorporate control systems which are slow and inefficient in operation. A further disadvantage of some prior art water closets is, under certain circumstances, it is possible to actually create a vacuum lock in the bowl with the inherent and potential risk to the user.
SUMMARY OF THE INVENTION
In view of the foregoing, it is the purpose of the present invention to provide a novel and improved vacuum flush water closet excluding the aforementioned disadvantages of the prior art vacuum flush water closets.
A further objective of the present invention is to provide a novel and improved vacuum flush water closet which possesses the virtue of simplicity, compactness, reasonably lightweight, economic to produce and efficient in operation.
A further objective of the present invention is to provide a novel and improved vacuum flush closet that will prevent a vacuum lock within the bowl should the upper opening be sealed during a flush cycle.
A further objective of the present invention is to provide a novel and improved vacuum flush water closet incorporating a self contained water dispensing valve and sewage discharge valve control system operatively mounted around and below the bowl.
A further objective of the present invention is to provide a novel and improved vacuum flush water closet having a manually operated sewage discharge valve which is fixedly attached below the bowl. A pivotal lever connected to the sewage discharge valve extends through an opening in the front of the bowl pedestal. The water closet is attached to a base mounting plate which in turn is secured to the floor/deck. A water dispensing valve is operatively mounted on the bowl. A normally closed three-way vacuum switch is operatively mounted below the bowl controlling the flushing water through the water dispensing valve.
A further objective of the present invention is to provide a novel and improved vacuum flush water closet having a sewage discharge valve that is manually operated by a foot pedal extending forwardly from the front of the bowl pedestal. The pedestal contains the operating mechanisms for the sewage discharge valve and a normally closed three-way vacuum switch.
A further objective of the present invention is to provide a novel and improved vacuum flush water closet which is individually controllable for regulating the sewage discharge valve opening time of the overall flushing cycle without increase in water consumption.
A further objective of the present invention is to provide a novel and improved vacuum flush water closet which includes a manually operable sewage discharge valve, a bowl having an outlet aperture at the lower end thereof which is operatively connected to the sewage discharge valve, the bowl having an open upper end with the rim therearound, a hinged seat operatively mounted on the rim, a flushing water dispensing valve operatively mounted on the bowl for directing a limited volume of water into the bowl, a manually operated foot pedal for controlling the sewage discharge valve opening and a three-way vacuum switch for enabling vacuum operation of the water dispensing valve.
Other features and advantages of this invention will be apparent from the following detailed description, appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a three dimensional representation of the vacuum flush toilet showing the foot pedal in the up position.
FIG. 2 is a sectional side elevation of the toilet shown in FIG. 1; the section plane runs through the centerline of the toilet with the exception the foot pedal which is shown rotated 30 degrees out of its true position.
FIG. 3 is an exploded view of the toilet. The components are shown separated to aid in assimilation of the overall design.
FIG. 4 is a plan elevation of the toilet shown in FIG. 1.
FIG. 5 is a fragmentary, enlarged sectional plan view of one of the rim flushing water nozzles illustrated in FIG. 2 taken along line 1--1.
FIG. 6 is a schematic diagram of the toilet control system of the present invention.
FIG. 7 is a reduced scale rear elevation of the toilet shown in FIG. 1. The view includes the water dispensing valve and some waste pipe orientation choices.
FIG. 8 is a fragmentary enlarged plan view of the flush lever and a cross section through the flush water cam illustrated in FIG. 2 taken along the line 2--2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and particularly FIGS. 1, 2, and 3, an illustrative vacuum flushing water closet embodiment of the invention's shown which comprises a bowl, generally indicated by the numeral 10, on which is operatively mounted a conventional toilet seat, generally indicated by the numeral 11. The toilet seat may be made from any suitable material such as plastic or wood. As shown in FIGS. 2 and 3, the water closet (or toilet) of the present invention includes a flushing water spray ring, generally indicated by the numeral 12, which is mounted around the upper rim of the bowl 10. The bowl 10 is secured in place, as more fully described hereinafter, on a base mounting plate generally indicated by the numeral 13. The base mounting plate 13 may be of any suitable material such as steel or aluminum.
As shown in FIGS. 1, 2, and 3, the water closet of the present invention is provided with a foot pedal, generally indicated by the numeral 14, which manually opens the sewage discharge valve 15. The foot pedal 14 extends from the pedestal portion of the bowl 10 and projects outwardly and slightly to one side of the centerfront at an angle of approximately 30 degrees. The foot pedal 14 is attached directly to the sewage discharge valve generally indicated by the numeral 15. The foot pedal 14 also strokes a cam 16 which initiates a flushing cycle by depressing a three-way vacuum switch 17. The three-way vacuum switch 17 is operatively connected to the water dispensing valve 18. The flushing water supply is controlled by the water dispensing valve 18.
The bowl 10 is a one piece china construction, the bowl interior having a minimum surface area consistent with the optimum shape and the maximum volume. Maintaining a minimum interior surface area for the bowl 10 allows the limited quantity of flush water to achieve the maximum possible cleansing action. The interior-exterior surfaces of the bowl 10 are finished in a hard smooth coating such as a vitrified porcelain and may be supplied in a variety of colors.
As illustrated in FIGS. 2, 3 and 7, the bowl 10 is releasably secured to the base mounting plate 13 by two threaded studs attached to the base mounting plate and bolted through the china base of the pedestal portion of the bowl. The base mounting plate 13 may be attached to the floor/deck by bolting or welding.
As shown in FIG. 2 the bowl 10 includes a body portion 21 which has formed around the upper end thereof a circumferentially extended vertical wall portion 22 which is surmounted by a horizontal surface 23. The lower end of the bowl body 21 terminates in a discharge hole as indicated by the numeral 24.
The upper horizontal surface 23 further includes an inner peripheral wall 25 which is integrally formed at its upper end with the horizontal surface. It can be noted that the inner vertical wall 25 is spaced inwardly from the bowl wall 22 to form a constant width groove around the inner periphery of the bowl.
The aforementioned groove serves as a concealment for the spray ring outlet nozzles 30, strategically located around the inner rim of the bowl. The rim 23 further includes an outer peripheral wall 28, which slopes outwardly and downwardly to a rounded edge 29.
As shown in FIGS. 2 and 5, the spray ring 12 is located in the outer pocket formed by the vertical walls 22 and 28, and the enclosing top surface 23. The spray ring may be formed of flexible tubing such as reinforced vinyl hose and be of adequate size to accommodate the required flow rate. The spray ring 12 includes a plurality of nozzles 30 strategically located around the bowl 10. The nozzles project through oversized rectangular access holes 31 located in the vertical wall 22. Each nozzle is inserted in a tee 26 and each tee is inserted in the spray ring 12 forming an integral water tight conduit. Each nozzle 30 is securely held in position by individual spring clips 27 that snap in place through the rectangular access holes 31. The nozzles 30 may be rotated 180 degrees or more to direct the water flow as desired. As shown in FIG. 2, the nozzles 30 can be oriented in a common direction so that the ejecting flushing water creates a swirling pattern within the bowl 10 scouring the surface with a more effective cleansing action.
As shown in FIGS. 1 and 2, the toilet seat 11 is fitted with a plurality of bumpers to maintain an opening and seat support, the seat shown is of the open front type less cover, although a conventional seat is acceptable, As illustrative in FIG. 1 the toilet seat 11 is attached to the bowl 10 by a pair of hinges located at the rear of the seat. As shown in FIG. 2 each hinge 32 includes a threaded shaft 33 that extends through the china surface 23. Each shaft is secured to the china surface 23 by washer 34 and nut 35. Also attached to the shafts 33 is the water dispensing valve bracket 36 which is fastened to the shaft 33 by an additional nut 37.
As shown in FIGS. 2 and 3, the water dispensing valve 18 is inserted through the water dispensing valve bracket 36 and secured in place with a jam nut 38. The water dispensing valve 18 may be rotated 180 degrees or more to accommodate the flush water supply line orientation. The water dispensing valve 18 is connected to the spray ring 12 by a special tee with O-rings 29 which is self sealing and allows the water dispensing valve 18 to be swiveled to suit the flush water supply line orientation previously noted. As shown in FIGS. 2 and 3, the sewage discharge valve 15 is attached to the bowl 10 by the threaded spigot 41 which is inserted downwardly through the bowl and screwed into the top cap 42. A bowl neck seal 43 is situated between the top cap 42 and the bowl 10 maintaining a leak tight seal when the threaded spigot 41 is tightened in place.
As shown in FIGS. 2 and 3, the sewage discharge valve, generally indicated by the numeral 15, comprises the following major items; top cap 42, flexible diaphragm 44, bottom cap 45, exit pipe 46, a torus shaped vacuum reservoir 40, that slides over and seals around the exit pipe 46 and a check valve 47. The diaphragm 44 is the seal between the vacuum source and the bowl 10. Diaphragm 44 seals against the inner rim of the top cap 42 and is held in place by a helical compression spring 48. There also occurs a differential air pressure between the upper and lower surfaces of the diaphragm 44 which produces a net upward force augmenting the spring closure force on the seal. The outer lip of the diaphragm 44 has a circular bead and is secured in an annular recess between the horizontal flanges of the top cap 42 and 45 respectively and provide the clamping force to secure and seal the diaphragm outer edge.
As shown in FIGS. 2 and 3, the foot pedal, generally indicated by the numeral 14 is attached to the sewage discharge valve 15 by a bolt 50 and a support tube 51. The bolt 50 screws into the lower end of the guide rod 49, the upper end attached to the diaphragm 44. The diaphragm 44 has an inner annular bead which is secured between the valve seat 54 and the support collar 55, all three items are locked together by the bolt 53 which is threaded into the upper end of the support tube 44. A bearing washer 56 is inserted between the support collar 55 and the guide tube 49.
As shown in FIG. 2, the foot pedal generally indicated by the numeral 14 includes a flush pedal 58, flush arm 52 and shroud 60. The flush arm 52 is pivotally mounted to the hinge bracket 61 which in turn is bolted to the inner surface of the pedestal portion of the bowl 10. A helical tension spring 62 holds the foot pedal 14 in the raised position against a pair of adjustable spring loaded stops 63. The stops 63 are set so that the flush arm 52 in its raised position allows the diaphragm 44 to fully close without hindrance. In the down position the flush pedal 58 rests on the ground and the bolt 50 is adjusted by (screwing in or out) the guide rod 43. In the down position the diaphragm should be approximately 96% of its full downwards travel.
As shown in FIG. 2, the flush water cam 16 is pivotally mounted to the three-way switch bracket 64 which in turn is bolted to the inner surface of the pedestal portion of the bowl 10. The cam 16 is located in a slot cut in the web of the flush arm 52 as shown in FIG. 8. When the flush arm 52 rotates from the raised position to the down position the cam roller 65 strokes the cam 16.
As the cam roller 65 moves through its annular travel it causes the cam 16 to rotate a fixed amount. The cam roller 65 engages the cam 16 after the diaphragm 44 has traveled downwardly approximately 10% of its vertical travel. The cam roller 65 disengages from the cam at the end of its travel. On the upward return stroke, the cam roller 65 repeats the process of engaging and disengaging the cam 16.
As shown in FIG. 2, the three-way switch 17 is attached to the three-way switch bracket 64. The three-way switch 17 is a normally closed vacuum switch and is shown schematically in FIG. 6. The upper port 66 is connected to the vacuum source within the sewage discharge valve 15 through the check valve 47 and tee 68. A supplementary vacuum reservoir 40 is attached to the third port on the tee 68. The lower port 67 is connected to the water dispensing valve 18 through the bleeder check valve 71 and tee 69. It can be noted whereas a normal check valve allows free flow in one direction and no flow in the opposite direction; a bleeder check valve allows free flow in one direction and controlled flow (or bleed) in the opposite direction. When the cam 16 is depressed by the foot pedal, as previously described, the three-way vacuum switch 17 plunger connects the lower port 67 to the upper port 66. This creates a vacuum at the water dispensing valve 18 causing it to open and allowing water to flow to the bowl 10. When the cam 16 is released, the plunger of the three-way vacuum switch 17 returns to its at rest position and vents the line to the water dispensing valve 18 shutting off the water flow. All vacuum lines interconnecting and aforementioned components are of a flexible material such as a non-rigid vinyl and of a wall thickness capable of withstanding the collapsing pressures created by the internal vacuum. Typically, the bores are sized to allow adequate flow rates within the required response times and will be 1/8" int/dia to 3/16" int/dia.
In normal operation the water closet is flushed by depressing the foot pedal 14 to the floor, holding it momentarily (1/2 to 1 second) and then releasing it. The foot pedal 14 will return to its raised or up position automatically and the sewage discharge valve 15 will close isolating the bowl 10 from the vacuum source. When the foot pedal 14 is depressed to the floor the sewage discharge valve 15 is pulled open and the cam 16 depresses the three-way vacuum switch 17 during the pivoting of the flush arm 52. As can be noted in FIG. 6, source vacuum is present in the sewage discharge valve 15, in the components, 40, 47, 68 and the associated vacuum lines 72, 73 and 74. When the sewage discharge valve 15 is opened the vacuum level drops instantaneously and the check valve 47 prevents a similar loss of vacuum in the associated circuitry. The vacuum reservoir 40 maintains the level of vacuum necessary to operate the circuitry during the flush cycle. At the completion of the flush cycle the vacuum reservoir 40 is recharged by the vacuum source connected to the closed sewage discharge valve 15.
The dynamics of a normal flush cycle operates in the following prescribed manner. As the foot pedal 14 is depressed, the cam 16 holds open the three-way vacuum switch 17 allowing vacuum to the water dispensing valve 18. The water dispensing valve 18 opens and flush water flows into the bowl 10 through the spray ring 12. There is a residual volume of water in the bowl (1 pint approximately) from the previous flush and this exits the bowl 10 with the flushing water. When the foot pedal is fully depressed, the cam 16 is released and the three-way vacuum switch closes venting the vacuum lines and allowing the water dispensing valve 18 to return to its normally closed condition (shutting off the water). The bleeder check valve 71 delays vent air reaching the water dispensing valve momentarily during which period the flush water continues to flow depositing a further 1 pint and then shuts off. On the return or upward stroke of the foot pedal 14 the same procedure repeats in reverse with a residual 1 pint of flush water being deposited in the bowl 10 after the sewage discharge valve 15 closes at the completion of the upward stroke. A normal 3 pint flush comprises, 1 pint residual in the bowl 10 from the last flush, 0.5 pints on the down stroke and likewise on the up stroke and 1 pint when the foot pedal is fully down.
The dynamics of an irregular flush cycle are circumscribed as follows; if the foot pedal 14 is held down for an indefinite period the flush water will cease after an approximate total flow of 2.5 pints. That is made up of 1 pint residual water in the bowl 10 prior to the flush, 0.5 pints as the cam 16 is actuated by the downward stroke of the flush arm 52 and the final 1 pint delivered by the delayed closure of the water dispensing valve 18 as heretofore described. This is a delayed shutoff and prevents a continuous discharge of water. When the foot pedal 14 is released, the flush will complete its normal cycle; that is 0.5 pints will flow on the upstroke and a final 1 pint delivery to the bowl preparatory to the next flush. If the foot pedal 14 is stopped in mid-stroke, (that is at some position between the full up and the full down position), the three-way vacuum switch 17 will remain in the open (unvented) position. The water dispensing valve 18 will continue to flush water through the bowl 10 until the bleeder check valve 70 exhausts the vacuum reservoir 40. When the vacuum reservoir 40 is exhausted the water dispensing valve will close. The bleeder valve 70 has a controlled air flow orifice that is too slow to affect normal flush operations, but will terminate the flush if the three-way vacuum switch 17 is held open for an abnormally long period. This is described as a limiting shutoff and the present bleeder check valve 70 has fixed orifice that will exhaust the vacuum reservoir in approximately 5 seconds, although this can be varied by changing the orifice in the bleeder check valve 70.
Although the preferred embodiment of the invention herein disclosed will perform in the manner prescribed it is subject to improvements and/or revisions. Therefore, the present embodiments are to be considered indicative of and not restricting in the scope of the invention. The appended claims define the specifics of the invention and any and all changes that may be incorporated which fall within the meaning and intent of equivalency of the claims are intended to be included herein.
The following claims are advanced in support of the preferred embodiment of the invention and for which an exclusive property and privilege is considered appropriate. | A vacuum flush water closet having the bowl, rim and pedestal made of china. The water closet has a self contained flushing water dispensing valve and sewage discharge valve control system operatively mounted around and under the bowl. The water closet is secured to the floor/deck by use of a base mounting plate. The sewage discharge valve is fixedly secured to the underside of the bowl and the said valve is manually opened and spring closed. Flushing water is supplied through a flexible flush tube mounted around the underside of the upper rim of the bowl. The flushing water is directed by a vacuum operated water dispensing valve. The operation of the water dispensing valve is controlled by a 3-way vacuum switch. The sewage discharge valve is manually operated by a foot pedal mounted below and in front of the bowl. The duration of the sewage discharge valve opening time is controlled by the manual operation and release of the foot pedal. The flushing water volme is limited by a programmed operation of the water dispensing valve and operates independently of the sewage discharge valve opening time. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. The Field of the Invention
[0002] The present invention relates to exercise devices. More specifically, the present invention relates to an exercise device having resilient elongate members for providing resistance against which a user can exercise.
[0003] 2. Background and Relevant Art
[0004] Society in general is becoming more health-conscious. A result of this has been an increased demand for fitness devices that can be utilized to attain and maintain healthy levels of fitness. Multi-function exercise machines have been developed in response to this demand. Multi-function exercise machines are often adapted to be convenient to operate and store, while still providing the range of exercises necessary to provide effective all around fitness.
[0005] One type of conventional multi-function exercise machine utilizes a stack of weights to provide resistance needed by users during exercise. A user repetitively raises some, or all, of the weight stack. The force of gravity provides the resistance needed to allow the user to exercise. However, due to the mass of the weights, these machines are heavy and can be difficult for a home user to move.
[0006] Exercise machines that use flexible members to provide resistance have been developed as an alternative to weight stack machines. One such device available in the market incorporates two sets of flexible rods of varying resistance. The bottom end of each set of rods is attached to the base of the machine with the rods extending vertically upwards therefrom. A cable is attached to the top end of each set of rods by means of a large hook that is threaded through loops at the top end of each rod. By bundling the rods in this manner, the user can adjust the amount of resistance used during exercise. By displacing the cables, a user can utilize the resistance provided by the flexible rods to exercise various muscle groups.
[0007] However, the manner in which the hook apparatus must be used to bundle the flexible rods together is awkward, requiring the use of two hands, i.e. a first hand to hold the hook and a second hand to thread the hook through the loops on the rods. Since there are two sets of rods, this process must be done twice.
[0008] In addition, since there are two sets of rods, there are two independent sources of resistance, adding a level of complexity to the use of the exercise apparatus. For example, the user must carefully monitor the amount of resistance used on each side in order to maintain equilateral workout resistances for each side of the body. Moreover, the length of the user's stroke is limited to the how far the ends of the flexible rods can be displaced, whereas certain exercises require a long stroke.
[0009] There is, therefore, a need for an improved exercise device that utilizes flexible members to provide resistance. There is a need for an exercise device having readily adjustable resistance that is simple and efficient. There is also a need for a device that has an efficient stroke length.
BRIEF SUMMARY AND OBJECTS OF THE INVENTION
[0010] The exercise machine of the present invention has a support assembly to which are coupled a plurality of resilient elongate members, a cable and pulley system, and, optionally, a bench. The exercise machine is adapted to allow a user to exercise using the resistance provided by the flexible, resilient, elongate members. The configuration of the exercise machine provides many benefits including, for example: exercise rods positioned on a fulcrum at the intermediate portion of the rods, a capture device enabling one handed addition and removal of resistance rods, movement of both ends of the resilient elongate members when the cable is drawn, equivalent resistance on both ends of the cable independently of whether equal amounts of resistance are provided at the cable ends, a cable and pulley system providing compounding effects of the resistance, rotatable resilient elongate members allowing convenient storage of the device, and a plurality of additional features and benefits.
[0011] A resilient elongate member assembly comprises a plurality of elongate members positioned on a fulcrum. In a preferred embodiment, horizontally oriented resilient elongate members of the present invention are centrally positioned on the fulcrum. The resilient elongate members flex when a force is applied to them, and are used to provide resistance for the user to exercise against. The user is able to adjust the amount of resistance used during exercise by using a pair of capture devices to add or delete resilient elongate members utilized to provide resistance. These are coupled to each end of a resilient elongate member and are adapted to allow the user to selectively capture resilient elongate members to increase or decrease the resistance. In a preferred embodiment, the capture device is adapted to allow the user to add or delete resilient elongate members using one hand.
[0012] The cable and pulley system comprises a plurality of pulleys and one or more cables. The cable and pulley system is configured such that a pulley is coupled to each end of a resilient elongate member assembly. A cable is adapted to be threaded through these pulleys. Additional pulleys are used to alter the direction of the cable to accommodate traditional exercise positions. Handles and other exercise accessories are adapted to be selectively coupled to the cable and pulley system to allow a user to utilize the resistance provided by the resilient elongate members. The resilient elongate members flex downwards following the path of the cable to provide resistance. Further pulleys are cables can be coupled to the machine to enable a wide variety of exercise to be undertaken.
[0013] The cable and pulley system of the present invention allows the user to take a long stroke due to the mechanical advantage provided by the cable and pulley system. The cable and pulley system also eliminates the need to capture the same amount of resistance at each end of the resilient elongate member assembly.
[0014] The user can benefit from a bench as source of balance and stability when doing exercises. A leg exercise unit is attached to the bench. The leg exercise unit can be connected to the cable and pulley system, thus allowing the user to undertake a variety of leg exercises against the resistance of the resilient elongate members.
[0015] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to describe the manner in which the above-recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0017] [0017]FIG. 1 illustrates a perspective front view of an exercise machine according to one embodiment of the present invention;
[0018] [0018]FIG. 2 is a perspective view of the back of the exercise machine of FIG. 1 featuring cables of the cable and pulley system and having alternative pulley brackets mounted onto a lower, horizontal member of the frame;
[0019] [0019]FIG. 3A illustrates a perspective view of a resilient elongate member assembly of the exercise machine the present invention;
[0020] [0020]FIG. 3B illustrates a top view of the resilient elongate member assembly of FIG. 3A;
[0021] [0021]FIG. 4 illustrates a perspective view of a capture device that is configured to capture the ends of one or more resilient elongate members according to one embodiment of the present invention;
[0022] [0022]FIG. 5A illustrates a perspective view of an alternative embodiment of a resilient elongate member assembly of the present invention featuring vertically stacked elongate members;
[0023] [0023]FIG. 5B illustrates a the assembly of FIG. 5A;
[0024] [0024]FIG. 5C illustrates a perspective view of another alternative embodiment of a vertically stacked resilient elongate member assembly;
[0025] [0025]FIG. 6 illustrates a resilient elongate member assembly of an exercise machine of the present invention showing the ends of multiple resilient elongate members held by one of the capture devices of the assembly;
[0026] [0026]FIG. 7 is a schematic perspective view of one embodiment of the cable and pulley system of an exercise machine of the present invention;
[0027] [0027]FIG. 8 is a perspective view illustrating the exercise machine of the present invention in which the resilient elongate members and bench are in a storage position (device shown without cables);
[0028] [0028]FIG. 9 illustrates a resilient elongate member assembly having a fulcrum which is rotatable, such that the resilient elongate member assembly is movable into a substantially horizontal use position or a substantially vertical storage position.
[0029] [0029]FIG. 10 is a view illustrating the resilient elongate member assembly of the present invention, including the rotatable fulcrum components according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] An exercise machine 10 of the present invention is shown in FIG. 1. Exercise machine 10 of FIG. 1 includes a support assembly 11 comprising (i) a frame 12 and (ii) a fulcrum 30 . Support assembly 11 provides a mechanism for integrating components of the exercise machine 10 , the components including, for example, a plurality of resilient elongate members 28 , a cable and pulley system 24 (cables not shown in FIG. 1), and, optionally, a bench 26 .
[0031] Frame 12 comprises a post 14 , a base member 16 which contacts a support surface (e.g., a floor or the ground), a lower horizontal member 18 and an upper horizontal member 20 . Post 14 provides a rigid upright for connecting various components of the present invention. Base member 16 is coupled to the bottom end of post 14 and may include wheels thereon for convenient moving of device 10 . Base member 16 provides a bottom support for post 14 .
[0032] Lower horizontal member 18 is coupled to post 14 . Upper horizontal member 20 is coupled to the upper portion of post 14 . Frame 12 can include a variety of components combined in a variety of configurations without departing from the scope and spirit of the present invention. For example, frame 12 can be configured such that one or more of the referenced components is not present. For instance, upper horizontal member 20 , which facilitates overhead exercises, is not provided on a machine designed only for low reach exercises.
[0033] In an alternative embodiment of the present invention, the frame comprises another vertical surface such as a wall or pole. Thus, a cable and pulley system (e.g., system 24 ) and a fulcrum (e.g., fulcrum 30 ) may be coupled to such a surface (e.g., a pole or wall), in which case the surface forms a frame for the device. A frame of substantially horizontal orientation can also be used.
[0034] A resilient elongate member assembly 22 of the present invention comprises: (i) a plurality of resilient elongate members 28 ; (ii) a fulcrum 30 ; and (iii) capture devices 32 , 34 . The plurality of resilient elongate members 28 of the present invention are positioned on fulcrum 30 .
[0035] In another embodiment, a resilient elongate member assembly of the present invention comprises a plurality of resilient elongate members coupled integrally to a fulcrum, which is coupled to the frame. In yet another embodiment, a single resilient elongate member is employed.
[0036] A cable and pulley system 24 is also coupled to frame 12 . The cable(s) of the system 24 are shown, for example, in FIGS. 2 and 7. Cable and pulley system 24 provides a mechanism for utilizing the resistance provided by the plurality of resilient elongate members 28 . In one embodiment, the cable and pulley system 24 is selectively coupled to frame 12 and at least one of the plurality of resilient elongate members 28 .
[0037] With reference now to FIG. 2, there is shown the cable and pulley system 24 of exercise machine 10 as well as additional components of exercise machine 10 . The exercise machine 10 includes a bench 26 coupled to upstanding member 14 of frame 12 . Bench 26 has an adjustable seat 106 and a leg exercise unit 108 . When performing certain exercises on the machine, the user sits on adjustable seat 106 to provide the necessary support and balance. Leg lever 110 of leg exercise unit 108 may be attached to cable and pulley system 24 by cable 114 . Cable 114 is fixed at a first end to leg lever 110 , is threaded over pulley 112 , and can be selectively coupled at its second end to first end 90 a or second end 90 b of cable 90 . In an alternative embodiment, the second end of cable 114 splits into or couples to dual cables, each dual cable end being coupleable to a corresponding end 90 a or 90 b of cable 90 . When cable 114 is coupled to cable 90 , force exerted on leg lever 110 is transmitted through cable 114 and cable 90 , causing the captured resilient elongate members to flex.
[0038] A variety of components and configurations of exercise device 10 can be utilized without departing from the scope or spirit of the present invention. For example, in alternative embodiments, a bench unit is not included as part of the exercise machine, or other components not previously discussed are utilized.
[0039] The cable and pulley system 24 comprises pulleys 36 , 38 , 76 , 78 , 80 , 82 , 84 , 86 , and 88 and cables 90 , 96 , 98 , and 114 . Optionally, a single cable may be substituted for cables 90 , 96 , and 98 . Pulleys 76 , 78 , and 80 are coupled to upstanding member 14 . Pulleys 82 , 84 are coupled to lower horizontal member 18 . Pulleys 86 , 88 are coupled to upper horizontal member 20 . Pulleys 36 , 38 are coupled to resilient elongate members 28 .
[0040] Cable 90 is coupled to pulleys 76 , 78 , 80 , 82 , 84 , 36 , 38 . Cable 90 comprises a first end 90 a , a second end 90 b , and an intermediate portion 90 c . The intermediate portion 90 c is the portion of cable 90 threaded through pulleys 76 , 78 , 80 , 82 , 84 , 36 , and 38 . Handles 92 , 94 are shown coupled to cables 96 , 98 , (e.g., for lat pull down exercises) but may optionally be coupled directly to opposing ends 90 a , 90 b of cable 90 for a variety of other exercises if desired.
[0041] First end 90 a and second end 90 b of cable 90 allow users to exert a force on resilient elongate members 28 . When a user displaces first end 90 a and/or second end 90 b , interaction between intermediate portion 90 c and pulleys 36 and 38 displaces pulleys 36 and 38 .
[0042] In one embodiment, the coupling of pulleys 36 and 38 to the ends of the one or more of the plurality of resilient elongate members 28 , and the associated configuration of cable 90 , is such that movement of the first end 90 a or second end 90 b of cable 90 causes movement of both ends of one or more of the plurality of resilient elongate members. For example, in the embodiment of FIG. 2, movement of the first end 90 a or second end 90 b of cable 90 causes movement of both ends of the resilient elongate member shown as being flexed in FIG. 2.
[0043] One or both ends of another resilient elongate member can be captured by one or more respective capture devices 32 shown in FIG. 2 in order to increase resistance (see FIG. 6). In other words, either one end or both ends of a resilient elongate member may be captured in order to increase resistance.
[0044] Pulleys 82 and 84 of FIG. 2 may be coupled to the lower horizontal member of frame 14 through a variety of different methods, such as through the use of (i) an eyebolt coupled to the frame and (ii) a u-shaped bracket or eyebolt coupled thereto, which is in turn coupled to the respective pulley bracket. In another embodiment, such as shown in FIG. 1 and in FIG. 8, the pulleys are coupled to the frame through the use of a pulley bracket coupled to a first tube (or pin), which pivots within a second tube coupled to the frame.
[0045] Ballstops 91 , 93 coupled to respective ends 90 a , 90 b prevent cable 90 from slipping off the pulleys of cable and pulley system 24 . Ballstops 91 , 93 also enable a degree of tension in cable and pulley system 24 .
[0046] As previously mentioned, to exercise using the machine, force is exerted on cable 90 . Cable 90 is adapted to be moved by the user against the resistance of the resilient elongate members.
[0047] The first end 90 a of cable 90 can be selectively coupled to detachable handle 92 or cable 96 . The second end 90 b of cable 90 can be selectively coupled to detachable handle 94 or cable 98 . This selective coupling allows the user to attach detachable handle 92 to first end 90 a and attach detachable handle 94 to second end 90 b and then move detachable handles 92 , 94 in a direction away from pulleys 82 , 84 . The user can then carry out a variety of low reach exercises.
[0048] Thus, the user can assemble the cable and pulley system and exercise on the device by attaching first end 96 a of cable 96 to first end 90 a of cable 90 ; attaching first end 98 a of cable 98 to second end 90 b of cable 90 ; coupling cable 96 to pulley 86 ; coupling cable 98 to pulley 88 ; attaching detachable handle 92 to second end 96 b of cable 96 ; attaching detachable handle 94 to second end 98 b of cable 98 ; and moving detachable handles 92 , 94 in a direction away from pulleys 86 , 88 . Optionally, handles 92 , 94 may be attached directly to cable 90 . Additionally, instead of detachable handles 92 , 94 , the user may attach an overhead bar 100 (FIG. 1) to cable 90 or to cables 96 , 98 at second ends 96 b , 98 b using eyelets 102 , 104 respectively. A variety of other mechanisms may also be employed.
[0049] With reference now to FIGS. 3A and 3B, there is shown resilient elongate member assembly 22 , which comprises fulcrum 30 and resilient elongate members 28 and capture devices 34 .
[0050] In one preferred embodiment, there are six flexible, resilient elongate members 42 , 44 , 46 , 48 , 50 , 52 , although fewer or more flexible, resilient elongate members can be used. They are positioned to contact fulcrum 30 of support assembly 11 at their intermediate portions 42 c , 44 c , 46 c , 48 c , 50 c , 52 c . By having intermediate portions 42 c , 44 c , 46 c , 48 c , 50 c , 52 c positioned in contact with support assembly 11 , downward movement of the ends of the resilient elongate members is resisted. The resilient elongate members are flexibly coupled to fulcrum 30 .
[0051] As will be appreciated by those skilled in the art, a variety of configurations of the resilient elongate member assembly can be utilized without departing from the scope and spirit of the present invention. For example, a plurality of separate flexible resilient elongate members can be utilized.
[0052] Alternatively, the resilient elongate member assembly comprises a single elongate member comprising an intermediate portion and a plurality of flexible resilient elongate fingers extending from opposing ends of the intermediate portion. In one such embodiment, the intermediate portion is integral with the fingers. For example, the resilient elongate member assembly may be molded as a single integral piece. The intermediate portion, for example, may be directly or indirectly coupled to a frame.
[0053] With continued reference to FIG. 3A, in one embodiment, fulcrum 30 is coupled to post 14 of frame 12 in part through the use of baseplate 14 . In an alternative embodiment, fulcrum 30 or another fulcrum of the present invention is integrally coupled to the frame. Thus, the fulcrum of the present invention may be integrally or non-integrally coupled to the frame. The fulcrum may be immovably coupled to the frame or movably coupled to the frame.
[0054] In one embodiment, fulcrum 30 is movably coupled to frame 14 . By being movably coupled, fulcrum 30 allows the plurality of resilient elongate members 28 to be rotatable between a first position (e.g., substantially horizontal) for use and a second position (e.g., substantially vertical) for storage.
[0055] In the embodiment illustrated in FIGS. 3 A and 8 - 10 , fulcrum 30 is movably coupled to upstanding member 14 . A locking assembly such as locking pin assembly 131 allows a user to selectively lock fulcrum 30 in a first position for use or in a second position for storage. In another embodiment, the fulcrum is immovably affixed (e.g., integrally or non-integrally) to the frame.
[0056] Resilient elongate members 42 , 44 , 46 , 48 , 50 , 52 provide resistance against which the user can exercise. Each flexible, resilient elongate member 42 , 44 , 46 , 48 , 50 , 52 has a first end 42 a , 44 a , 46 a , 48 a , 50 a , 52 a and a second end 42 b , 44 b , 46 b , 48 b , 50 b , 52 b that extend away from respective intermediate portions thereof. Each resilient elongate member is comprised of a resilient material. In a preferred embodiment, the resilient elongate member is comprised of nylon, although other materials are possible, such as wood laminates, steel leaf springs, fiberglass and/or acetal.
[0057] The elongate members may further comprise a coating on the nylon material or other material employed, such as a protective coating, e.g., a polyolefin material, or a variety of other coatings which may provide a protective layer and/or an aesthetically pleasing appearance. However, such coatings are not required. In one embodiment, the elongate members comprise a gripping/wear-resistance material 27 (FIG. 3A) at the tips thereof, which may comprise an ABS plastic material, for example. A number or other indicia can be provided on the gripping/wear-resistance material 27 to identify the amount of resistance that is provided by each elongate member.
[0058] In a preferred embodiment, the resilient elongate members are adapted to provide a range of different amounts of resistance. In one embodiment, the amount of resistance provided by resilient elongate members 42 , 44 , 46 , 48 , 50 , 52 corresponds with the diameter of the resilient elongate member. A variety of different diameters may be employed. For example, resilient elongate members 46 , 44 , 42 , 48 , 50 , and 52 may have diameters of ⅞ inch, 1 inch, {fraction (11/16)} inch, 1 inch, ¾ inch and ⅝ inch respectively, for example. 1⅛ inch members may be vertically stacked above such members, for example. However, in alternative embodiments other diameters can be used. Optionally, seven elongate members, or one, two, three, four, five, eight, nine, ten, or a vast number of possibilities of other members may be employed. In an alternative embodiment all the resilient elongate members have the same diameter. In yet another embodiment, different resistance amounts are provided irrespective of the diameter of the resilient elongate members, e.g., by employing different materials.
[0059] Resilient elongate member 42 is shown in a flexed position in FIG. 3A. Coupled to resilient elongate member 42 at first end 42 a is a capture device 32 , which is in turn coupled to pulley 36 . Coupled to resilient elongate member 42 at second end 42 b is capture device 34 , which is in turn coupled to pulley 38 . In alternative embodiments, fewer or more pulleys can be coupled to the capture devices. In yet another embodiment, one or more resilient elongate members are coupled directly to resilient elongate members 28 .
[0060] With reference now to FIGS. 4 and 10, there is shown capture device 32 according to one embodiment of the present invention, which may be the same as or similar to capture device 34 . Capture device 32 comprises a main body 54 , a first capture member 56 coupled to the main body 54 , a second capture member 58 coupled to the main body 54 , and a first tab 60 and a second tab 62 extending from respective capture members. Capture members 56 , 58 are substantially horizontal in orientation. The main body 54 is coupled lengthwise to resilient elongate member 42 .
[0061] Extending outwards from main body 54 are first capture member 56 and second capture member 58 . Extending downwards from first capture member 56 is first tab 62 , and extending downwards from second capture member 58 is second tab 60 . As will be appreciated by those skilled in the art, capture devices with fewer or more capture members and tabs are possible.
[0062] Main body 54 may be coupled to a resilient elongate member by means of an upper aperture 64 , into which the resilient elongate member is inserted. Pulley 36 is coupled to the main body 54 of capture device 32 by means of a pin 66 extending through the pulley bracket and a lower aperture of main body 54 . Pin 66 allows pulley 36 to pivot in its coupling with main body 54 , while the machine is being used.
[0063] With reference now to FIGS. 5A and 5B, there is shown an alternative embodiment of a resilient elongate member assembly 22 z . The resilient elongate assembly 22 z comprises a fulcrum 30 z , a plurality of resilient elongate members 28 z and two capture devices 32 z , 34 z . In this embodiment, resilient elongate members 28 z are arranged in two rows 29 , 31 . There are eight resilient elongate members 42 z , 44 z , 45 , 46 z , 47 , 48 z , 50 z , 52 z . In order to be able to capture row 31 of resilient elongate members 28 z , capture device 32 z has a pair of capture members 57 , 59 mounted on top of capture members 56 z , 58 z . Capture device 34 z is similarly configured. By having more resilient elongate members, the total amount of resistance that the user is able to select is increased.
[0064] With reference now to FIG. 5C there is shown yet another alternative embodiment of a resilient elongate member assembly 22 y . In the embodiment, capture members 57 , 59 are mounted on top of capture device 32 y such that capture member 57 and capture member 59 form openings facing the same direction. The openings are configured to capture resilient elongate members 45 and 47 . Capture members 57 , 59 are mounted on top of capture members 56 y , 58 y . Capture device 34 y is similarly configured. In the embodiment, resilient elongate members 45 and 47 are positioned such that resilient elongate member 45 is placed immediately above resilient elongate member 47 .
[0065] With reference now to FIG. 6, there is shown how capture devices 32 , 34 are used to capture resilient elongate members. It can be seen that resilient elongate members 44 , 48 have been captured at their first ends 44 a , 48 a by capture device 32 . The capturing of resilient elongate members 44 , 48 is accomplished by capture members 56 , 58 . Thus, it can be seen that first end 44 a of resilient elongate member 44 is captured underneath capture member 56 of capture device 32 . The resilient elongate members are prevented from horizontal movement by respective tabs 60 . 62 .
[0066] Once captured, resilient elongate members 44 , 48 are subject to the force applied at pulley 36 and flex as a result of the application of force. By selecting the number and configuration of resilient elongate members to capture, the user is able to select the amount of resistance with which to exercise. The more resilient elongate members that are captured, the higher the resistance provided. In one embodiment, the amount of resistance depends on the diameter of the resilient elongate members captured. In an alternative embodiment, resilient elongate members of different materials can be used in the resilient elongate member assembly, and resistance can depend on the material of the resilient elongate members captured.
[0067] Capture device 32 allows a user to select and retain at least one end of resilient elongate member 44 . To capture the resilient elongate member 44 , the user presses downwards on first end 44 a and manipulates it around tab 62 or tab 60 to position an end 44 of the resilient elongate member 44 under a capture member 56 or 58 . Once first end 44 a is below capture device 32 , the user releases first end 44 a . By releasing first end 44 a , the resilience of the resilient elongate member biases the first end 44 a upward and under capture device 32 such that capture device 32 retains first end 44 a . The user can then perform the same operation with the second end 44 b of member 44 and capture device 34 if the user desires to capture both ends of resilient elongate member 44 . However, only a single end may be captured if desired.
[0068] Unlike devices of the prior art, capture device 32 of the present invention is adapted to eliminate the need to thread the resilient elongate members 28 onto a hook-like device. Neither do the resilient elongate members 28 need to be configured to receive a hook-like device. The present invention merely requires that the user manipulate the end of the resilient elongate member under the capture device. In addition to simplifying adjustment of the resistance amount, the user can make such adjustments using only one hand. This allows the user to use both hands to capture two resilient elongate members at the one time, making the process of varying the resistance more efficient. Further, each hand can manipulate more than one resilient elongate member at once. In a preferred embodiment, the user can capture every resilient elongate member simultaneously using both hands. To release a resilient elongate member, the operation is performed in reverse. Again, the release of the resilient elongate members can be accomplished using only one hand.
[0069] In the embodiment of FIGS. 1, 3A, and 6 , since resilient elongate member 42 is always affixed to the cable and pulley system, some resistance is always provided. From this starting point, any subsequent increase in resistance can be accomplished by capturing a resilient elongate member using one hand.
[0070] Once resilient elongate members 28 are captured, the resilient elongate members 28 can remain in a defined path as they flex. As a result, resilient elongate members 28 flex evenly.
[0071] Fulcrum 30 comprises an assembly that covers the top and bottom surfaces of an intermediate portion of elongate members. Thus, fulcrum 30 is configured such that one or both ends of a particular elongate member may be flexed. Fulcrum may be configured as a clamshell assembly (see, e.g., FIG. 10).
[0072] With reference now to FIG. 7, there is shown the cable and pulley system as illustrated in FIG. 2 according to one embodiment of the present invention. The cable and pulley system is adapted to convey resistance provided by one or more resilient elongate members. In one embodiment, one or more cables of the cable and pulley system are adapted to be coupled to a first and second point of resistance provided by the resilient elongate members. In the illustrated embodiment, pulleys 36 , 38 are essentially floating pulleys. By using floating pulleys, the total amount of displacement provided by the cable first and second ends is greater than the total amount of displacement provided by the first and second end of the resilient elongate member when the first end and second end of the resilient elongate member are flexed.
[0073] In the present embodiment, pulleys 36 , 38 are coupled to the resilient elongate members 28 by means of capture devices 32 , 34 . Movement of the resilient elongate members in response to a force applied to cable 90 is approximately doubled at the first end 90 a and second end 90 b of cable 90 . In other words, the amount of cable displaced as the user pulls both ends of the cable is approximately twice the amount of displacement of both ends of the resilient elongate members. This means that during an exercise routine the user has more cable to manipulate, so a longer stroke can be accomplished with a smaller relative displacement of the resilient elongate members. This allows the user to assume normal, traditional, and/or comfortable positions when using the machine. Pulleys 36 , 38 represent one example of a first and second point of resistance.
[0074] When force is exerted on cable 90 at either one or both ends 90 a , 90 b of cable 90 , both ends of captured resilient elongate members will move. Thus, a force can be exerted on cable 90 by a first and/or second grip member adapted to permit a user to utilize a resistance conveyed by the cable and pulley system. The amount of movement depends on the amount of resistance captured. In one embodiment, the resistive force of the first end of each resilient elongate member is equal to the resistive force of the second end of the resilient elongate member. However, unequal amounts of resistance captured on each side of the machine can result from having different configurations of flexible elongate members retained by the capture devices on each side of the exercise machine. The movement of each resilient elongate member is in inverse proportion to its resistive force. Thus, the end with captured resilient elongate members providing the least amount of total resistance will be drawn downwards the farthest distance.
[0075] Nevertheless, independent of the amount of resistance captured on each side, the resistance experienced at first end 90 a of cable 90 will be the same as that experienced at second end 90 b . This is achieved because of the configuration of the pulley and cable system of the present invention.
[0076] Thus, an equal amount of resistance will be provided to a first and second grip member 92 , 94 even through an unequal amount of resistance is provided at the first and second points of resistance (e.g., pulleys 36 , 38 ). If an equal amount of force is applied by the user to both ends 90 a , 90 b then the same amount of cable will be drawn at each end. This will occur despite any unevenness in the amount of movement of the first ends 42 a , 44 a , 46 a , 48 a , 50 a , 52 a , and second ends 42 b , 44 b , 46 b , 48 b , 50 b , 52 b of the resilient elongate members 42 , 44 , 46 , 48 , 50 , 52 .
[0077] This means that the user does not have to ensure that each capture device 32 , 34 captures the same number and type of resilient elongate members. In short, the user need not obtain an equal amount of resistance on each capture member 32 , 34 for each cable end 90 a , 90 b to obtain an equal proportion of encountered resistance during exercise. Thus, it is possible for the device to be used effectively with resilient elongate members captured only at one end, for example.
[0078] When force is exerted by a user at only one end of cable 90 , the mechanical advantage provided by pulleys 36 , 38 is approximately four fold. When force is exerted by a user at both ends of cable 90 , the mechanical advantage experienced is approximately two fold. Essentially, for any given amount of captured resistance, it is easier to pull with one hand at one end of cable 90 than with one hand at each end of cable 90 .
[0079] Thus, the total resistance experienced when force is simultaneously exerted at both ends of the cable is greater than the resistance experienced at the first end of the cable when force is exerted at the first end alone. In one embodiment, the total resistance experienced when force is simultaneously exerted at both ends of the cable is approximately twice the resistance experienced at the first end of the cable when force is exerted at the first end alone. In light of the unique configuration of this device, this resistance is experienced by the user along with the balanced feel of equal resistance in the opposing ends of the cable.
[0080] With reference now to FIGS. 8 - 10 , there is shown an embodiment of the exercise machine 10 illustrating the manner in which the exercise machine 10 is adapted to be placed in a storage position or a use position. In the embodiment shown, bench 26 and the plurality of resilient elongate members 28 are foldable to allow exercise machine 10 to be placed in a storage position.
[0081] When exercise machine 10 is in the storage position (FIG. 8), bench 26 and the plurality of resilient elongate members 28 are positioned adjacent to, and substantially parallel with, the upper portion of post 14 in a substantially vertical orientation. In the use position, bench 28 is positioned substantially perpendicular to post 14 and is resting on the floor and the plurality of resilient elongate members 28 are positioned substantially perpendicular to post 14 . For an example of bench 26 and the plurality of resilient elongate members 28 in a use position, see FIG. 1.
[0082] In the embodiment of FIGS. 8 - 10 , frame 12 comprises a pin 132 on which fulcrum 30 is rotatably coupled, such that fulcrum 30 is rotatably coupled to frame 12 . Pin 132 serves as an inner pin since it is positioned within fulcrum 30 during use.
[0083] With reference now to FIG. 10, fulcrum 30 comprises outer tube 134 , bushings 136 , 138 , end cap 139 , bottom fulcrum plate 142 , and top cover 144 . Outer tube 134 is mounted on inner pin 132 with the bushings placed therebetween. Outer tube 134 is selectively rotatable about inner pin 132 and has plate 142 coupled thereto. Locking pin assembly 131 is adapted to allow a user to selectively lock the resilient elongate members 28 in a storage position or in a use position by selectively locking outer tube 134 with respect to inner pin 132 . Locking pin assembly 131 maintains fulcrum 30 in a fixed position on frame 14 . In one embodiment, locking pin assembly 131 allows the user to select the amount of force used to secure the fulcrum 30 to frame 14 .
[0084] Inner pin 132 is coupled to baseplate 40 , which is coupled to post 14 of frame 12 . Inner pin 132 provides a support around which outer tube 134 rotates. Inner pin 132 includes a plurality bores 133 (e.g., three bores) spaced radially about inner pin 132 . The bores may be placed on the sides and bottom of pin 132 , for example, such that the elongate members selectively achieve (i) a substantially horizontal position when moved above pin 132 or substantially vertical positions when moved to either side of pin 132 .
[0085] Bores 133 are adapted to receive the distal end of a pin 131 a of locking pin assembly 131 , which can extend partially through outer tube 134 and into a bore 133 . This allows the user to lock fulcrum 30 in the storage position or the use position. As indicated above, outer tube 134 is adapted to rotate around inner pin 132 . Bushings 136 and 138 are positioned between inner pin 132 and outer tube 134 to reduce the friction between inner pin 132 and outer tube 134 during rotation of outer tube 134 . End cap 139 is positioned at the end of outer tube 134 distal to baseplate 40 . End cap 139 is adapted to cover the aperture formed by outer tube 134 .
[0086] In the embodiment shown, bottom fulcrum plate 142 of fulcrum 30 is coupled to outer tube 134 . A plurality of pins (e.g., six pins or any number corresponding to the number of elongate members) extend upwardly from bottom fulcrum plate 142 . The pins extending from plate 142 are adapted to be positioned in slots (not shown) formed on the underside surface of respective intermediate portions of resilient elongate members. In one embodiment, the configuration of slots in the elongate members and respective pins which fit therein allow for limited lateral movement of resilient elongate members, although the slots may be configured not to allow such lateral movement. The pins of plate 142 which fit into the slots in respective members 28 retain the intermediate portions of members 28 within fulcrum 30 even when the members 28 are moved to a storage position. Thus the members 28 do not slide out of the fulcrum 30 .
[0087] Top plate 144 of fulcrum 30 is configured to be positioned over the plurality of resilient elongate members 28 and coupled to bottom plate 142 with the elongate members extending through respective slots in the top plate. Thus, resilient elongate members 28 are positioned between bottom fulcrum plate 142 and top cover 144 shown in FIG. 10 in a clamshell configuration. Bottom plate 142 may be angled downwardly on the sides thereof to accommodate the downward movement of the opposing sides of the elongate members.
[0088] In another embodiment, the elongate members are positioned within slots in the fulcrum and are allowed to freely slide within the slots or have rings or pins on opposing sides of the elongate members near the fulcrum that prevent them from sliding off the fulcrum.
[0089] In the embodiment of FIG. 10, locking pin assembly 131 includes a locking pin 131 a coupled at its proximal end to a locking pin handle 131 b . The locking pin 131 a is slidably and/or rotatably coupled within a hollow body 131 c . Hollow body 131 c is threadedly coupled to the wall (e.g., the underside wall) of outer tube 134 . This allows the distal end of the locking pin 131 a to be inserted into a desired bore 133 in inner pin 132 in order to lock outer tube 134 with respect to inner pin 132 . Locking pin 131 a may be spring loaded and/or threaded at the distal end thereof such that pin 131 a may be conveniently, selectively, removably coupled within a desired bore 133 and conveniently maintain outer tube 134 in a desired position with respect to inner pin 132 .
[0090] To change the position of resilient elongate members 28 , a user uncouples locking pin 131 a away from inner pin 132 , e.g., by unthreading pin 131 a from a desired bore 133 (and/or pulling a springloaded pin out of the bore), then rotates outer tube 134 . Once the user rotates the outer tube 134 to a desired position, the user can then couple pin 131 a into another bore 133 , such as by threading the distal end of pin 131 a into bore 133 (and/or allowing a spring loaded pin to slide into the bore). Thus, in one embodiment, locking pin 131 a is spring loaded and distal threads on locking pin 131 a can be threaded into a bore 133 in order to affix fulcrum 30 into a tightly locked position. In yet another embodiment, a locking pin of the present invention is merely a threaded or non-threaded pin.
[0091] Fulcrum 30 of FIG. 10, however, is merely one embodiment of a fulcrum of the present invention. A fulcrum of the present invention may comprise a variety of different objects or surfaces which an elongate member or members contact as one or more ends of the elongate members is flexed. For example, a pin, rod, plate, beam, member, post, assembly, mechanism, or any surface thereof may act as a fulcrum. For instance, a surface of a post (e.g., the top surface of a post or other portion of a post on which a member or members may be mounted) may serve as an integral fulcrum on which an elongate member or plurality of members may be positioned as the end or ends thereof are flexed. As another example, a pin or beam extending from a frame is another example of a fulcrum upon which an elongate member can be positioned.
[0092] As a major advantage to the exercise device of the present invention, a variety of different exercises may be performed on the exercise devices of the present invention, such as leg curls, biceps curls, reverse flys, chest press, triceps press-downs, ab crunches, leg presses, leg extensions, lat pull downs, butterflys, and a variety of other exercises.
[0093] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | An exercise machine has resilient elongate members for providing balanced resistance in the form of elongate resilient members oriented horizontally such that the intermediate portion of the elongate members contact a fulcrum of the exercise machine. The user adjusts the amount of resistance provided by capturing different combinations and numbers of resilient elongate members. A cable and pulley system ensures a long stroke so that the use can perform a wide variety of exercises in comfortable positions. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 12/902,202, filed Oct. 12, 2010, entitled “CONTAINER, AND SELECTIVELY FORMED CUP, TOOLING AND ASSOCIATED METHOD FOR PROVIDING SAME,” which is incorporated by reference as if fully set forth herein, and claims the benefit of Provisional Application No. 61/253,633, filed on Oct. 21, 2009, entitled “CONTAINER, AND SELECTIVELY FORMED CUP, TOOLING AND ASSOCIATED METHOD FOR PROVIDING SAME,” which is incorporated by reference as if fully set forth herein.
BACKGROUND
1. Field
The disclosed concept relates generally to containers and, more particularly, to metal containers such as, for example, beer or beverage cans, as well as food cans. The disclosed concept also relates to cups and blanks for forming cups and containers. The disclosed concept further relates to methods and tooling for selectively forming a cup or bottom portion of a container to reduce the amount of material in the cup or bottom portion.
2. Background Information
It is generally well known to draw and iron a sheet metal blank to make a thin walled container or can body for packaging beverages (e.g., carbonated beverages; non-carbonated beverages), food or other substances. Typically, one of the initial steps in forming such containers is to form a cup. The cup is generally shorter and wider than the finished container. Accordingly, the cups are typically subjected to a variety of additional processes that further form the cup into the finished container. As shown, for example, in FIG. 1 , a conventional can body 2 has thinned sidewalls 4 , 6 and a bottom profile 8 , which includes an outwardly protruding annular ridge 10 . The bottom profile 8 slopes inwardly from the annular ridge 10 to form an inwardly projecting dome portion 12 . The can body 2 is formed from a blank of material 14 (e.g., without limitation, sheet metal).
There is a constant desire in the industry to reduce the gauge, and thus the amount, of material used to form such containers. However, among other disadvantages associated with the formation of containers from relatively thin gauge material, is the tendency of the container to wrinkle, particularly during redrawing and doming. Prior proposals have, in large part, focused on forming bottom profiles of various shapes that were intended to be strong and, therefore, capable of resisting buckling while enabling metal having a thinner base gauge to be used to make the can body. Thus, the conventional desire has been to maintain the material thickness in the dome and bottom profile to maintain or increase strength in this area of the can body and thereby avoid wrinkling.
Tooling for forming domed cups or can bodies has conventionally included a curved, convex punch core and a concave die core, such that a domed can body is formed from material (e.g., without limitation, a sheet metal blank) conveyed between the punch core and the die core. Typically, the punch core extends downwardly into the die core, forming the domed cup or can body. In order to maintain the thickness of the domed portion, the material is relatively lightly clamped on either side of the portion to be domed. That is, the material can move (e.g., slide) or flow toward the dome as it is formed in order to maintain the desired thickness in the bottom profile. Doming methods and apparatus are disclosed, for example and without limitation, in U.S. Pat. Nos. 4,685,322; 4,723,433; 5,024,077; 5,154,075; 5,394,727; 5,881,593; 6,070,447; and 7,124,613, which are hereby incorporated herein by reference.
There is, therefore, room for improvement in containers such as beer/beverage cans and food cans, as well as in selectively formed cups and tooling and methods for providing such cups and containers.
SUMMARY
These needs and others are met by embodiments of the disclosed concept, which provide metal containers, such as beverage and food cans, cups and blanks for forming cups and containers, and methods and tooling for selectively forming a cup or bottom portion of a container to reduce the amount of material in the cup or bottom portion.
As one aspect of the disclosed concept, a container comprises: a first sidewall; a second sidewall; and a bottom portion extending between the first sidewall and the second sidewall. The material of the bottom portion is stretched relative to the first sidewall and the second sidewall to form a thinned preselected profile.
The thinned preselected profile may be a dome. The material of the container at or about the dome may have a substantially uniform thickness. The container may be formed from a blank of material, wherein the blank of material has a base gauge prior to being formed. After being formed, the material of the container at or about the dome may have a thickness less than the base gauge. The thickness of the material at or about the dome may be about 0.0003 inch to about 0.003 inch thinner than the base gauge.
The container may be formed from a blank of material, wherein the blank of material has a preformed dome portion.
As another aspect of the disclosed concept, tooling is provided for selectively forming a blank of material into a container. The container includes a first sidewall, a second sidewall, and a bottom portion extending between the first sidewall and the second sidewall. The tooling comprises: an upper tooling assembly; and a lower tooling assembly. The blank of material is clamped between the upper tooling assembly and the lower tooling assembly, proximate to the first sidewall and proximate to the second sidewall. The bottom portion is stretched relative to the first sidewall and the second sidewall to form a thinned preselected profile.
As a further aspect of the disclosed concept, a method for selectively forming a container is provided. The method comprises: introducing a blank of material to tooling; forming the blank of material to include a first sidewall, a second sidewall and a bottom portion extending between the first sidewall and the second sidewall; clamping the material between the tooling proximate to the first sidewall and proximate to the second sidewall to resist movement of the material; and stretching the bottom portion to form a thinned preselected profile.
BRIEF DESCRIPTION OF THE DRAWINGS
A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
FIG. 1 is a side elevation view of a beverage can and a blank of material used to form the beverage can;
FIG. 2 is a side elevation view of one non-limiting example of a container and a blank of from which the container is formed in accordance with an embodiment of the disclosed concept, also showing, in phantom line drawing, a pre-formed blank of material in accordance with another aspect of the disclosed concept;
FIG. 3 is a side elevation section view of tooling in accordance with an embodiment of the disclosed concept;
FIG. 4 is a side elevation section view of tooling in accordance with another embodiment of the disclosed concept;
FIG. 5 is a top plan view of a portion of the tooling of FIG. 4 ;
FIG. 6 is a section view taken along line 6 - 6 of FIG. 5 ;
FIG. 7 is a section view taken along line 7 - 7 of FIG. 5 ;
FIG. 8 is an enlarged view of segment 8 of FIG. 6 ;
FIGS. 9A-9D are side elevation views of consecutive forming stages of a cup, in accordance with a non-limiting example embodiment of the disclosed concept;
FIGS. 10A-10C are side elevation views of consecutive forming stages of a cup, in accordance with another non-limiting example embodiment of the disclosed concept;
FIGS. 11A-11D are side elevation views showing the metal thickness of the cup thinned in accordance with a non-limiting example embodiment of the disclosed concept, respectively showing the substantial uniform thickness of the dome in a direction with the grain of the material, in a direction against the grain, in a direction at 45 degrees with respect to the grain, and in a direction 135 degrees with respect to the grain;
FIG. 12 is a graph plotting the metal thickness of the dome at various locations of the dome, in accordance with a non-limiting example embodiment of the disclosed concept; and
FIG. 13 is a graph plotting the metal thickness of the base metal and of the dome at the various locations of the dome of FIG. 12 , for each of the directions of FIGS. 11A-11D , as well as in the cross grain direction.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of illustration, embodiments of the disclosed concept will be described as applied to cups, although it will become apparent that they could also be employed to suitably stretch the end panel or bottom portion of any known or suitable can body or container (e.g., without limitation, beverage/beer cans; food cans).
It will be appreciated that the specific elements illustrated in the figures herein and described in the following specification are simply exemplary embodiments of the disclosed concept, which are provided as non-limiting examples solely for the purpose of illustration. Therefore, specific dimensions, orientations and other physical characteristics related to the embodiments disclosed herein are not to be considered limiting on the scope of the disclosed concept.
Directional phrases used herein, such as, for example, left, right, front, back, top, bottom, upper, lower and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.
As employed herein, the statement that two or more parts are “coupled” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts.
As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality).
FIG. 2 shows a blank of material 20 and a beverage can 22 having a selectively formed bottom profile 24 in accordance with one non-limiting example of in accordance with the disclosed concept. Specifically, as described in detail hereinbelow, the material in the can bottom 24 and, in particular the domed portion 26 thereof, has been stretched, thereby thinning it. Although the example of FIG. 2 shows a beverage can, it will be appreciated that the disclosed concept can be employed to stretch and thin the bottom portion of any known or suitable alternative type of container (e.g., without limitation, food can (not shown)), or cup (see, for example, cup 122 of FIGS. 9A-9D and 11A-11D , and cup 222 of FIGS. 10A-10C ), which is subsequently further formed into such a container.
It will also be appreciated that the particular dimensions shown in FIG. 2 (and all of the figures provided herein) are provided solely for purposes of illustration and are not limiting on the scope of the disclosed concept. That is, any known or alternative thinning of the base gauge could be implemented for any known or suitable container, end panel, or cup, without departing from the scope of the disclosed concept. In the non-limiting example of FIG. 2 , the can body 22 has a wall thickness of 0.0040 inch and a substantially uniform thickness in the can bottom 24 and dome 26 of 0.0098 inch. Thus, the material in the can bottom 24 has been thinned by about 0.0010 inch from the base gauge of the blank of material 20 of 0.0108 inch. It will be appreciated that this is a substantial reduction, which results in significant weight reduction and cost savings over conventional cans (see, for example, the can body 2 of FIG. 1 having a can bottom 8 thickness of 0.0108 inch). Additionally, among other advantages, this enables a smaller blank of material to be used to form the same can body. For example and without limitation, the blank 20 in the non-limiting example of FIG. 2 has a diameter of about 5.325 inches, whereas the blank 14 of FIG. 1 has a diameter of about 5.400 inches. This, in turn, enables a shorter coil width (not shown) of material to be employed (i.e., supplied to the tooling), resulting in less shipping cost.
Moreover, the disclosed concept achieves material thinning and an associated reduction in the overall amount and weight of material, without incurring increased material processing charges associated with the stock material that is supplied to form the end product. For example and without limitation, increased processing (e.g., rolling) of the stock material to reduce the base gauge (i.e., thickness) of the material can undesirably result in a relatively substantial increase in initial cost of the material. The disclosed concept achieves desired thinning and reduction, yet uses stock material having a more conventional and, therefore, less expensive base gauge.
Continuing to refer to FIG. 2 , it will be appreciated that the disclosed concept could employ, or be implemented to be employed with, preformed blanks of material 20 ′. For example and without limitation, a preformed blank of material 20 ′ having a preformed dome portion 26 ′ is shown in phantom line drawing in FIG. 2 . Such a preformed blank 20 ′ could be fed to the tooling 300 ( FIG. 3 ), 300 ′ ( FIGS. 4-8 ) and subsequently further formed into the desired cup 122 ( FIGS. 9A-9D and 11A-11D ), 222 ( FIGS. 10A-10C ) or container 22 ( FIG. 1 ). One advantage of such a preformed blank of material 20 ′, is the ability of a plurality of such blanks 20 ′ to nest, one within another, for purposes of transporting and shipping the blanks 20 ′. The preformed dome portion 26 ′ also provides a mechanism to grab and orient the blank 20 ′ within the tooling 300 ( FIG. 3 ), 300 ′ ( FIGS. 4-8 ), as desired. Furthermore, it also enables the width of the blank 20 ′ to be still further reduced. For example and without limitation, in the non-limiting example of FIG. 2 , the preformed blank 20 ′ has a reduced diameter of 5.300 inches.
FIGS. 3-8 show various tooling 300 ( FIG. 3 ), 300 ′ ( FIGS. 4-8 ) for stretching and thinning the container material (e.g., without limitation, blank; cup; can body), in accordance with the disclosed concept. Specifically, the selective forming (e.g., stretching) is accomplished by way of precise tooling geometry and placement. In accordance with one non-limiting embodiment, the process begins by introducing a blank of material (e.g., without limitation, blank 20 ) between components of a tooling assembly 300 ( FIG. 3 ), 300 ′ ( FIGS. 4-8 ), and forming a standard flat bottom cup 122 (see, for example, FIGS. 9A and 10A ) with base metal thickness or gauge.
As shown in FIGS. 3 and 4 , the tooling preferably includes a forming punch 304 ( FIG. 3 ), 304 ′ ( FIG. 4 ), and a lower tool assembly 306 ( FIG. 3 ), 306 ′ ( FIG. 4 ). After the cup 122 is formed, the forming punch 304 continues moving downward, pushing the cup 122 lower until the cup 122 contacts a lower pad 308 , 308 ′. In the non-limiting embodiment shown and described herein, the lower pad 308 has a contoured step bead 310 (best shown in the enlarged view of FIG. 8 as step bead 310 ′ in lower pad 308 ′), although it will be appreciated that such a step bead is not required. The contoured step bead 310 , 310 ′ facilitates holding the material substantially stationary, for example, by crimping it and locking the material just inboard of the cup sidewall 124 , as shown in FIG. 8 . In this manner, the material in the sidewall 124 is held securely, preventing it from sliding or flowing into the bottom portion 128 of the cup 122 . Accordingly, it will be appreciated that the disclosed concept differs substantially from conventional container bottom forming (e.g., without limitation, doming) methods and apparatus. That is, while the side portions of the cup or container in a traditional forming process might be clamped, relatively little pressure is applied so that movement (e.g., sliding; flowing) of the material into the bottom portion of the cup or container is promoted. In other words, traditionally clamping and stretching the material in the bottom portion of the container was expressly avoided, so as to maintain the thickness of the material in the bottom portion.
It will be appreciated that the aforementioned step bead 310 , 310 ′ is not a required aspect of the disclosed concept. For example, FIGS. 9A-9D illustrate the consecutive steps or stages of forming a non-limiting example cup 122 in accordance with an embodiment of the disclosed concept wherein the tooling 300 , 300 ′ includes the step bead 310 , 310 ′, whereas FIGS. 10A-10C illustrate the consecutive forming stages of a cup 222 in accordance with another embodiment of the disclosed concept wherein the tooling does not include any step bead. It will be appreciated that while four forming stages are shown in FIGS. 9A-9D and three forming stages are shown in the example of FIGS. 10A-10C , that any known or suitable alternative number and/or order of forming stages could be performed to suitably stretch and thin material in accordance with the disclosed concept. It will further be appreciated that any known or suitable mechanism for sufficiently securing the material to resist movement (e.g., sliding) or flow of the material into the bottom portion 128 (e.g., dome 130 ) could be employed, without departing from the scope of the disclosed concept. For example and without limitation, pressure to secure the sides 124 , 126 of the cup 122 or container body 22 ( FIG. 2 ), or locations proximate thereto, can be provided pneumatically, as generally shown in FIG. 3 , or by a predetermined number of biasing elements (e.g., without limitation, springs 312 , 314 ), as shown in FIGS. 4-7 , or by any other know or suitable holding means (e.g., without limitation, hydraulic force) or mechanism (not shown).
In accordance with one non-limiting embodiment of the disclosed concept, it will be appreciated that although the material is clamped (e.g., secured in a substantially fixed position) so as not to permit it to move (e.g., slide) or flow, and to instead be stretched in a subsequent forming step, the amount of force (e.g., pressure) that is necessary to apply such a clamping effect, is preferably minimized. In this manner, it is possible to provide the necessary clamping force to facilitate the disclosed stretching and thinning, without requiring a different press (e.g., without limitation, a press having greater capacity) (not shown). Accordingly, the disclosed concept can advantageously be readily employed with existing equipment in use in the field, by relatively quickly and easily retooling the existing press.
Table 1 quantifies the clamping force and deflection resulting from employing different numbers (e.g., 5; 10; 20) of springs (e.g., without limitation, springs 312 , 314 ) to apply the clamping force in accordance with several non-limiting example embodiments of the disclosed concept.
TABLE 1
deflec-
deflec-
tion
load
tion
load
×5
×10
×20
(mm)
(kg)
(in)
(lbs)
springs
springs
springs
4
6.2%
60
0.16
132.2
661.2
1,322.4
2,644.8
10.4
16.0%
156
0.41
343.8
1,719.1
3,438.2
6,876.5
11
16.9%
176
0.43
387.9
1,939.5
3,879.0
7,758.1
13
20.0%
195
0.51
429.8
2,148.9
4,297.8
8,595.6
Once the peripheral material is suitably clamped (e.g., secured in a substantially fixed in position, as shown for example and without limitation in FIG. 8 ), the punch 304 ′ continues to move downward, forcing the material in the cup bottom area 128 to be forced into the contour 316 ( FIGS. 6-8 ) of the tools 300 ′ causing the material to stretch into the contoured shape 130 ( FIGS. 9D, 10C, 11A-11D, 12 and 13 ), thereby thinning the material. A non-limiting example of a cup 122 which has been formed in accordance with this process is shown in FIGS. 9A-9D (tooling 300 ′ includes step bead 310 ′). Another example cup 222 is shown in FIGS. 10A-10C (tooling does not include step bead). It will be appreciated, for example with reference to FIG. 9D , that the material in the dome portion 130 ( FIGS. 9D and 11D ), 230 ( FIG. 106 ) can be stretched and, therefore, thinned by up to about 0.001 inch, or more. It will also be appreciated that while the contoured shape in the example shown and described herein is a dome 130 , 230 , that any other known or suitable alternative shapes could be formed without departing from the scope of the disclosed concept.
Referring to FIGS. 9C, 9D, 11A-11D, 12 and 13 , it will be appreciated that the stretched material of the dome portion 130 is also advantageously substantially uniform in thickness. More specifically, the material is uniform in thickness not only for various locations (see, for example, measurement locations A-I of FIGS. 12 and 13 ) along the width or diameter of the dome 130 , as shown in FIGS. 9C (partially formed cup dome 130 ′) and 9 D (completely formed cup dome 130 ), but also in various directions, such as with the grain as shown in FIGS. 11A and 13 , against the grain as shown in FIGS. 11B and 13 , at 45 degrees with respect to the grain as shown in FIGS. 11C and 13 , and at 135 degrees with respect to the grain, as shown in FIGS. 11D and 13 . The graphs of FIGS. 12 and 13 further confirm these findings. FIG. 13 shows, in one graph, a plot of the metal thicknesses at locations A-I for each of the foregoing directions with respect to the grain, as well as in the cross grain direction.
Accordingly, it will be appreciated that the disclosed concept provides tooling 300 ( FIG. 3 ), 300 ′( FIGS. 4-8 ) and methods for selectively stretching and thinning the bottom portion 24 ( FIG. 2 ), 128 ( FIGS. 9A-9D and 11A-11D ), 228 ( FIGS. 10A-10C ) of a container 22 ( FIG. 2 ) or cup 122 ( FIGS. 9A-9D and 11A-11D ), 222 FIGS. 10A-10C ), such as a domed portion 26 ( FIG. 2 ), 130 ( FIGS. 9D and 11A-11D ), 230 ( FIG. 10C ), thereby providing relatively substantially material and cost savings.
While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof. | A container, such as a beverage or food can is provided, which includes a first sidewall, a second sidewall and a bottom portion extending between the first and second sidewalls. The material of the bottom portion is stretched relative to the first sidewall and the second sidewall to form a thinned preselected profile, such as a dome. The material of the container at or about the dome has a substantially uniform thickness. The container is formed from a blank of material, which has a base gauge prior to being formed. After being formed, the material of the container at or about the dome has a thickness less than the base gauge. Tooling and a method for selectively forming a blank of material into a container, are also disclosed. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to an apparatus for simplifying the process of applying setting material onto a surface. More particularly, the present invention relates to an apparatus for applying a desired amount, level and location of setting material on a controlled area of surface for speedy and level setting of stones, such as marble, granite, or the like.
[0003] 2. Background of the Prior Art
[0004] In setting stones or tiles, there is a limit to the time allotted. Specifically, there is usually a preset time for the setting material, generally including “mud,” to set on a supporting surface. The minimum time to apply adhesive materials and “mud” to level a supporting surface, and then apply adhesive to a stone (or marble, granite, etc.) before placement is often limited.
[0005] In particular, minimum time is required for the installation of “mud” to level the supporting surface, and minimum time is required for the “mud” to set on that surface to a degree necessary for supporting stone or the like. To ensure economy and efficiency in setting stones or the like, time must be allotted to set up the required amount of stone or the like to be set in a day, and there must be a sure way of providing a level top surface to all of the stone.
[0006] Consequently, there exists an unfulfilled need for an apparatus and method for simple and efficient application of setting materials before stone placement.
SUMMARY OF THE INVENTION
[0007] It is a general object of the present invention to minimize the time in setting stone and the like, so that more stone can be set per day than could be heretofore.
[0008] It is a further object of the present invention to provide a novel apparatus and method for applying setting material which may be easily and efficiently manufactured and marketed.
[0009] Yet another object of the present invention is to provide a unique apparatus and method for applying setting material which is compatible with common stone adhesives and manner of attachment.
[0010] Another object of the present invention is to provide an apparatus and method to efficiently set stones and the like on a level plane.
[0011] It is further an object of the present invention to provide a method for applying “mud” which will set in a minimum amount of time, and provide a plurality of globular masses of setting material to level a supporting surface. In attaining the foregoing and other objects, the present invention provides a plate which is supported at a predetermined distance above a supporting surface. The plate is of a predetermined thickness, and is surrounded by a wall which is higher than the plate so that mud can be scraped from the plate and cannot fall outside the plate. The supporting legs of the plate are of adjustable length so that accommodations can be made in the length of the legs, whereby the top surface of the plate will be level, regardless of the supporting surface. The “mud” referred to is more or less a standard component of setting material that will harden at a certain height in a minimum amount of time. In addition, setting material preferably includes an adhesive substance to be applied to the supporting surface before application of the mud and to the stone, tile, and the like before placement onto the mud.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where
[0013] [0013]FIG. 1 is a perspective view of the plate assembly consistent with the present invention;
[0014] [0014]FIG. 2 is a somewhat schematic section of the plate as set up for applying setting material an embodiment of the present invention;
[0015] [0015]FIG. 3 is a somewhat schematic view in cross section showing the method of applying the setting material in an embodiment of the present invention;
[0016] [0016]FIG. 4 is a sectional view of the “mud” forming the setting material in accordance with the present invention;
[0017] [0017]FIGS. 5 and 5 a are exploded perspective views illustrating how the studs or legs of an embodiment of the present invention are mounted; and
[0018] [0018]FIG. 6 is an exploded perspective view of the plate assembly consistent with the present invention.
DETAILED DESCRIPTION
[0019] The invention summarized above and defined by the enumerated claims may be better understood by referring to the following detailed description, which should be read in conjunction with the accompanying drawings. This detailed description of particular embodiments, set out below to enable one to practice the invention, is not intended to limit the enumerated claims, but to serve as a particular example thereof. Those skilled in the art should appreciate that they can readily use the concepts and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent methods and systems do not depart from the spirit and scope of the invention in its broadest form.
[0020] Referring to FIG. 1, in order to set stones, tiles, or the like, an apparatus according to the present invention preferably includes a plate having a plurality of apertures, illustrated as sixteen holes 5 , a square plate 10 , and upstanding peripheral wall 15 , all of which may be made of any suitable material such as plastic, aluminum, steel, rubber, wood or the like, and held together in any suitable manner with such materials as screws, glues, bolts and the like. In an embodiment of the present invention, brass is used in making the apparatus and the apparatus is preferably welded together. Ideally, the holes 5 are drilled into the plate to prevent any undesirable surface defects. In an alternate embodiment, the holes 5 are stamped or punched through plate 10 .
[0021] In the illustration provided, there are sixteen aligned holes 5 . The number and dimensions of the holes 5 may vary with the overall size of the apparatus. In addition, the plate 10 may vary in size and shape. In an embodiment of the present invention, the plate 10 is square and manufactured with a border extending beyond the wall 15 , leaving a circumferential plate 20 . The circumferential plate 20 preferably extends a half inch on each side beyond the wall 15 .
[0022] In the middle of each wall 15 section, there is a sleeve 25 . The sleeve 25 is preferably secured at its lower end to the circumferential plate 20 . The sleeve 25 includes a sleeve circumference 30 which is ideally secured to the wall 15 . In an embodiment of the present invention, the sleeve circumference 30 contains a smooth surface along both the interior and exterior. In an alternate embodiment of the present invention, the plate 10 , wall 15 , and sleeves 25 can be made as one solid part.
[0023] A bore is preferably inserted through the sleeve 25 to enable a hole to be provided in the circumferential plate 20 in alignment with the sleeve 25 . A leg 35 extends through each sleeve 25 , of which there are preferably four, and the leg 35 is readily slideable into the bored hole. A spherical head 40 has a screw by which it is secured to the leg 35 . A knob 45 on a threaded stud 50 extends through a threaded hole 55 for clamping engagement with the leg 35 to hold the leg in place. In an alternate embodiment of the present invention, rather than the spherical head 40 , a knob or the like is coupled to the leg 35 . In yet another embodiment of the present invention, the leg 35 is threaded and the bored hole through plate 10 is threaded so that the leg 35 may be threadedly inserted through the circumferential plate 10 .
[0024] The legs 35 , of which there are preferably four, are each engageable with a threaded stud 50 in order to hold the plate 10 at a fixed height above the supporting surface. The height above the surface is determined by how far the legs 35 extend, and this can be adjusted quickly and readily by loosening or tightening the threaded stud 50 .
[0025] If the supporting surface is flat and level, there will not be any need for adjustment by way of the threaded stud 50 . If one area of the surface has a declivity or a rising high spot in it, this can be readily accommodated by way of adjusting one or more of the threaded studs 50 to adjust the leg 35 . If there is a large area representing a change in height of the supporting surface, then this can be accommodated by changing the entire height of the apparatus by adjusting all legs by manipulating all of the threaded studs 50 . In an embodiment of the present invention, the screw height is readily adjustable to conform with the surface 50 .
[0026] As illustrated in FIG. 2, application of the setting material commences with placing setting material within the wall 15 as a shapeless mass 200 .
[0027] [0027]FIG. 3 illustrates the step of smoothing the shapeless mass 200 of setting material across the top of the plate 10 . Smoothing the shapeless mass 200 of setting material across the top of the plate 10 causes the setting material to fall through the holes 5 to form substantially globular masses 300 .
[0028] [0028]FIG. 4 illustrates final formed setting material applied by an embodiment of the present invention. When the setting material falls through holes 5 , substantially globular masses 300 of setting material corresponding to holes 5 form beneath the plate 10 having a common level surface at 400 . Globular masses 300 of setting material have a common level surface 400 no matter where they occur, so that the stone or the like is set on a level plane. The globular masses 300 are shown as four in number in FIG. 3, but are shown as five in number in FIG. 4 to illustrate that the number of holes 5 can vary in embodiments of the invention. The structure heretofore described is removed while the setting material or mud is still in a semi-solid state so that it remains as globules as shown in FIGS. 3 and 4. Excess material can be left in a setting state on top of the plate 10 where it can be reclaimed for further use to form the globular masses 300 as shown in FIGS. 3 and 4.
[0029] A sketch shown in FIG. 5, illustrates how the spherical head 40 is mounted to the leg 35 . FIG. 5 a illustrates a sketch of the mounting of the threaded stud 50 having knob 45 through threaded hole 55 of sleeve 25 .
[0030] [0030]FIG. 6 is an illustration of an embodiment of the present invention for setting tiles. The apparatus includes a plate 10 , holes 5 and the wall 15 . The plate 10 and wall 15 are preferably welded together in order that there shall be no leaks, and fit quite nicely as shown. In this embodiment, no legs are included and setting material is placed within the wall 15 and smoothed over the holes 5 . Preferably, excess setting material is removed once the setting material has filled holes 5 . The apparatus is then removed to allow for placement of tiles or the like.
[0031] The assembly of an apparatus consistent with the present invention, is preferably a permanent one. The plate and the walls are of material that are sturdy, and the threaded stud 50 , the sleeve 25 , and the leg 35 are made of sturdy material as well as are ideally easily replaced. The number of holes shown herein is a handy number and may be chosen by the installer.
[0032] The number and size of the supporting surface and of the holes 5 are relatively small, speeding the application of setting material. Generally, the number of rows and columns of holes are partly dependent on the type of stones or tiles or the like to be laid. The number and size of the holes 5 and other parts of the apparatus are a matter of the size of the apparatus, and are designed based on the needs of the artisan.
[0033] The setting material on which the stone, or other flooring such as tile, is laid preferably consists of three layers. The first layer is preferably of adhesive or coating material painted on the back of a stone. The next or second layer is ideally mud of the approximate thickness of the plate 10 or of the length of the legs 35 , and the third is preferably another layer of adhesive or coating material of the thickness distributed by means of painting on the supporting surface, such as a floor.
[0034] The thickness of the first and third layers is so small that it need not be included in calculating the height of the globular masses 300 of mud. The setting of the adhesive or coating material forming the first and third layers is known in the art, and can be calculated. The adhesive or coating material is preferably spread by V-notched trowel.
[0035] The assembly as heretofore described is complete, and the number of holes is a matter of choice for the artisan laying the floor. | An apparatus and method is provided for use in laying stone and the like onto floors. The number of apertures in the apparatus may vary, and a wall surrounds the plate of the apparatus as set forth. There are four articles for adjusting the height of the apparatus above a supporting floor to adjust the amount and level of setting material to be applied. In an alternate embodiment, the thickness of the plate of the apparatus determines how thick the setting material to be applied. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national phase application pursuant to 35 U.S.C. §371 of International Application No. PCT/EE2008/000004, filed Mar. 27, 2008, which claims priority to Estonia Application No. P200700012, filed Mar. 28, 2007.
TECHNICAL FIELD OF THE INVENTION
[0002] The current invention is most widely in the field of molecular biology, more particularly in the field of virology and provides a means for introducing changes into a genome of a eukaryotic cell, which may be duplications, multiplications, insertions, deletions, inversions and/or translocations of a DNA sequence.
BACKGROUND OF THE INVENTION
[0003] Papillomaviruses are small species-specific DNA tumor viruses that establish latent infection in the basal cells of the differentiating epithelium with the help of viral oncoproteins and maintain their small, about 8 kb, circular doublestranded (ds) genomes as episomal multicopy nuclear plasmids in proliferating transformed cells (Howley and Lowy, 2001) via action of the viral replication proteins E1 and E2 (Ustav and Stenlund, 1991; Chiang et al., 1992; Sverdrup and Khan, 1994). The E1 protein is the replication origin recognition factor and viral helicase (Yang et al., 1993; Sedman and Stenlund, 1998), which in cooperation with E2 facilitates recognition and effective loading of the host cell replication complexes at the papillomavirus origin in the upstream regulatory region (URR) (Ustav et al., 1991, 1993; Remm et al., 1992; Russell and Botchan, 1995; Stenlund, 2003).
[0004] In the latently infected basal cells, the high-risk (HR)-HPV genomes persist as episomal multicopy circular nuclear plasmids in order to support the viral life cycle. However, coexistence of the integrated and the episomal forms of HPV DNA in the same cells has been reported (Cooper et al., 1991; Kristiansen et al., 1994; Alazawi et al., 2002; Peitsaro et al., 2002a, b; Andersson et al., 2005; Arias-Pulido et al., 2006; Kulmala et al., 2006; Pett et al., 2006). The trigger for HPV integration is unclear, but linear fragments generated by dsDNA breaks of the genome or by ‘onion skin’ type of defective viral replication mode (Männik et al., 2002) may serve as substrates for integration ( FIG. 7 , steps 1 and 2 ). The ability of HPV-16 E7 to induce abnormal centrosome numbers is well known, which subsequently results in chromosome missegregation and aneuploidy (Duensing and Munger, 2002, 2004). Increase of E1 concentration above a certain level results in overly frequent loading of the viral hexameric helicase and cellular replication complexes at the viral origin and induction of ‘onion skin’-type replication intermediates on the viral genome (Männik et al., 2002). Consequently, complicated topological structures of the ‘onion skin’-type replication intermediates as well as heterogeneous linear subgenomic fragments are generated. Based on tissue tropism, more than 100 different types of human papillomaviruses (HPVs) are divided into subgroups of mucosal or cutaneous papillomaviruses; individual viruses from each group are designated ‘high risk’ or low risk' according to the propensity of the infected transformed cells for malignant progression (zur Hausen, 2002; de Villiers et al., 2004; Munger et al., 2004).
[0005] Cells carrying integrated HR-HPV sequences have selective growth advantage due to the increased cell immortalization (Romanczuk and Howley, 1992; Jeon et al., 1995). In the case of HPV18, HPV31 and HPV35, nearly 100% of the viral sequences show integration into the cancer cell genome. Integrated and episomal viral genomes are commonly found in the HPV16 DNA-positive cancers (Cooper et al., 1991; Kristiansen et al., 1994; Peitsaro et al., 2002a, b; Andersson et al., 2005; Arias-Pulido et al., 2006).
[0006] The papillomaviruses do not follow once-per-cell cycle replication mode (Ravnan et al., 1992; Piirsoo et al., 1996); therefore, multiple unscheduled initiation events at the functional integrated HPV origin could extend into the adjacent genomic locus and trigger rearrangements like deletions or duplications of the sequences of the cellular genome by repair/recombination machinery.
DISCLOSURE OF THE INVENTION
[0007] The present invention is based on the ability of the HPV genome including its replication origin sequence to start DNA replication in two directions from the location of the replication origin sequence in the presence of HPV early proteins, in particular the E1 and E2 protein of various HPV strains. The authors have studied the events that may contribute to the formation of invasive cancers in the case of HR-HPV infections by demonstrating the effective HPV E1- and E2-dependent DNA amplification of the integrated HPV18 and HPV16 origins in HeLa and SiHa cells, respectively. The replication forks initiated at the integrated HPV origins extend into the flanking regions of cellular DNA. These amplified genomic sequences, resembling ‘onion skin’-type DNA replication intermediates as targets for the recombination and repair system that causes excisions of these sequences, resulting in de novo rearrangements and recombinations within the cellular DNA.
[0008] In result single-stranded or double-stranded DNA fragments were generated. These fragments possess biological activity. The fragments may be used as antisense DNA, DNAzyme or decoy-DNA. Moreover, any kind of these fragments may be used for therapeutical applications.
[0009] The integrated HR-HPV origin is effectively mobilized for replication by E1 and E2 produced from respective expression vectors, and from episomal HPV genomes transiently replicating in these cells. As a result, amplification of the integrated HR-HPV genome and flanking cellular DNA sequences occurs ( FIG. 7 , step 3), which can serve as targets for repair/recombination machinery. This results in rearrangements, including deletion as seen by the excision of HPV18 sequences or de novo integration of amplified sequences, as demonstrated by the analysis of the subclones ( FIG. 7 , step 4). One may assume that modifications of the genome providing gain of the function result in transformation of cells and will give a growth advantage to the cells after the loss of episomal viral genome.
[0010] Also de novo infection of papillomaviruses could result in intracellular mixture of episomal and integrated HPV and subsequent amplification of integrated HPV DNA together with flanking cellular sequences ( FIG. 7 , step 5). Therefore also the LR-HPVs is able to initiate DNA replication from the integrated HR-HPV origin. In addition to amplification of regulatory sequences or genes driving the cell cycle, there is also a possibility for the deletion of genomic sequences. The SiHa cell line itself is an example of such a process where cellular sequences flanking the HPV16 integration site (el Awady et al., 1987) lack approximately 300 kb within the intact chromosome 13 (according to the 36th assembly of human genome, NCBI, released in November 2005).
[0011] We can call it ‘hit-and-run’ mechanism as ‘lowrisk’ or ‘high-risk’ HPV episome itself could be lost quickly after the infection, but the damage caused by the chromosome-associated HR-HPV amplification remains.
[0012] The presented data suggest that papillomavirus DNA replication machinery can actively induce irreversible changes in the genomic make-up of the cell at sites of HPV origin integration. The results show that papillomavirus replication proteins are capable of mobilizing integrated HPV origin and that simultaneous DNA replication of episomal and integrated HPV origins may occur in HeLa cells. These kinds of changes provide a useful tool for research, if one wishes to amplify, excise or translocate a genomic sequence, either adjacent to the integration site of the HPV sequence or wishes to introduce foreign sequences to the cell with respectively constructed HPV vector. The kit including HPV replication origin and overexpression of genes encoding HPV E1 and E2 for introducing duplications, multiplications, insertions, deletions, inversions and/or translocations of a DNA sequence into a eukaryotic cell is particularly important as it exhibits unexpectedly good viability of the transfected cells thus making the system a good model for in vivo experimentation. Moreover, amplification of a DNA sequence encoding functional units of heredity allows this combination to serve as basis for gene expression and overexpression experiments. The beforementioned kit comprises a vector carrying HPV genome or a part of HPV genome including HPV replication origin sequence, and expression vector or vectors encoding HPV early proteins, e.g. E1 and E2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 HPV E1 and E2 proteins initiate the replication from episomal and integrated HPV origins in HeLa cells.
[0014] (A, B) HeLa cells were cotransfected with plasmids for expression of homologous E2 and E1 from HPV6b (lanes 1-4), HPV11 (lanes 5-8), HPV16 (lanes 9-12) and HPV18 (lanes 13-16) together with 0.5 μg of pUCURR-6b, -11, -16 and -18, respectively. As controls, either 5 μg pMHE1-18 and 5 μg pQMNE2-18 (lanes 17 and 18) or 0.5 μg pUCURR18 alone (lanes 19 and 20) was transfected. A 3 μg measure of total DNA extracted 24 and 48 h after transfection was digested with HindIII/DpnI and analyzed by Southern blotting with radiolabeled pUC probe (A) or all four HPV URR sequences (B). (C) Schematic presentation of the HPV6b, -11, -16 and -18 E1 expression constructs. (D) Analysis of expression of HA epitopetagged E1 of HPV6b (lanes 1 and 2), HPV11 (lanes 3 and 4), HPV16 (lanes 5 and 6) and HPV18 (lanes 7 and 8) 48 h after transfection with 3F10-HRP antibody. (E) Schematic representation of the episomal HPV18 genome and the integrated HPV18 in HeLa cells (Lazo, 1987; Meissner, 1999). Cellular DNA is shown as dashed line and HPV18 DNA as solid line. Open arrows represent the viral ORFs and noncoding URR shown as an open box.
[0015] FIG. 2 Replication of integrated HPV18 is dependent on E1 protein concentration, while E2 has no effect.
[0016] (A, E) Increasing amounts of HPV18 E1 expression plasmids (from 0.5 to 10 μg) were cotransfected with 1 μg of HPV18 E2 expression vector. Total cellular DNA was extracted 24 h and 48 h after transfection and 3 μg of DNA was digested with HindIII (A) or BamHI (E) and analyzed by Southern blotting with 32 P-labeled HPV18 URR probe. (B) Southern blot analysis of HeLa cells transfected with HPV18 E1 vector (5 μg) and an increasing amount of HPV18 E2 vector (0.5-10 pg). DpnI was used to remove input plasmids. (C) Western blot analysis of HPV18 E1 protein expression in HeLa cells 48 h after transfection with 3F10-HRP antibody. (D) Western blot analysis of HPV18 E2 protein with 4E4 antibody. (E) Total cellular DNA was extracted at various time points from cells transfected with 1 μg pQME2-18 and 10 μg pMHE1-18 (lanes 1-6) or from mock-transfected cells (lanes 7-12); 3 pg from each DNA sample was digested with BamHI/DpnI and subjected to Southern blotting analysis with 32 P-labeled HPV18 URR-specific probe.
[0017] FIG. 3 Amplification of integrated HPV16 URR in SiHa cells transfected with HPV E1 and E2 expression vectors.
[0018] (A) Schematic presentation of the integrated HPV16 genome in chromosome 13 in SiHa cells. Viral ORFs are shown as open arrows and URR is indicated by an open box. Numbers in italics indicate the nucleotides of viral genome at the junction with cellular DNA. Acc65I restriction sites at nt 880 and nt 5378 of the viral genome are shown (B) SiHa cells were transfected. with expression vectors for E1 and E2 as follows: 2.5-20 μg of HPV6b E1 (lanes 1-4); 2.5-20 μg of HPV11 E1 (lanes 5-8); 1.2-5 μg of HPV16 E1 (lanes 9-11) and 1.2-5 μg of HPV18 E1 (lanes 10-12). A 5 μg measure of homologous E2 expression vectors was added for each transfection. For controls, either 5 μg pMHE1-16 alone (lane 13) or 5 μg pQMNE2-16 alone (lane 14) was transfected into the cells. The total DNA was isolated 24 h after transfection and 3 pg was digested with Acc65I/DpnI and analyzed by Southern blotting using radiolabeled HPV16 URR probe. (C) Analysis of E1 protein expression in SiHa cells 24 h after transfection using Western blot.
[0019] FIG. 4 Amplification of the integrated HPV16 origin and flanking cellular sequences induced by HR-HPV E1 and E2 proteins.
[0020] (A) Graphical representation of amplification of HPV16 URR and flanking sequences of two independent experiments, as described in (B). A 5 μg portion of pMHE1-16 and 5 μg pQMNE2-16 (dashed line in panel A and second row in panel B) or 5 μg pMHE1-18 and 5 μg pQMNE2-18 (solid line in panel A and third row in panel B) were transfected into SiHa cells. A 3 pg portion of total cellular DNA was extracted 24 h after transfection, digested with different enzyme combinations (indicated at the top in panel B, restriction sites shown in panel A) and then subjected to Southern blot analysis. Filters were probed with either radiolabeled HPV16 URR (lane 3 in panel B) or with cellular sequences (panel B, lanes 1, 2, 4 and 5) from various distances from both sides of the viral integration (SL1, SL2, SR1 and SR2). The replication signals were quantified on PhosphorImager and normalized to the signal from the mock-transfected SiHa cells. The average increase in copy numbers of different sequences is calculated (shown by vertical italic numbers in the graph in panel A). (C) Graphical representation of the results from two independent experiments, where 5 μg pQMNE2-18 together with increasing amounts of pMHE1-18 (2.5 μg, dotted line; 5 μg, dashed line; 10 μg, solid line) was transfected into SiHa cells. The replication signals were analyzed as described above and the average copy numbers corresponding to different sequences (URR-16, SL1, SL2, SR1, and SR2) are shown in the table (D).
[0021] FIG. 5 Coreplication of integrated and episomal HPV18 in HeLa cells.
[0022] (A) Low-molecular-weight DNA was extracted from HeLa cells at 48 and 96 h after transfection and (B) total DNA isolated from transfected HeLa cells at 48 h was analyzed by Southern blotting. A 3 μg portion of pUCHPV18 alone (lanes 2 and 3 in panel A and lane 1 in panel B), together with 10 μg pMHE1-18 (lanes 4 and 5 in panel A and lane 2 in panel B) or 10 μg pMHE1-18 and 2.5 μg pQMNE2-18 (lanes 6 and 7 in panel A and lane 3 in panel B), was transfected into HeLa cells. As controls, HeLa cells were transfected with 1 μg pUC-URR18 and 10 μg pMHE1-18 (lanes 8 and 9 in panel A and lane 4 in panel B), or together with 2.5 μg pQMNE2-18 (lanes 10 and 11 in panel A and lane 5 in panel B). A 5 μg portion of total DNA or half of the material from 60 mm dish (in case of low-molecular-weight DNA) was digested with HindIII/DpnI followed by Southern blot analysis with labeled HPV18 URR probe. Mock transfections (lane 1 in panel A and lane 6 in panel B) as well as 100 pg of HindIII-digested pUCHPV18 and pUC-URR18 are shown (lane 12 in panel A and lane 7 in panel B). (C) Southern blot analysis of the total population (lane 2) and sorted GFP-positive cells (lane 3) cotransfected with 10 pg pUCHPV18 plasmid and 0.5 μg pEGFP-N1. Sample from mock transfection is shown in lane 1. Markers of pUCHPV18 plasmid are shown in lanes 4-7; numbers indicated in the figure correspond to the copy number per cell. The total cellular DNA was extracted 48 h after transfection and 1.6 μg of it (corresponding to 2.5×10 5 diploid cells) was analyzed in each lane as described above. The results from two independent experiments are presented in (D).
[0023] FIG. 6 Chromosomal rearrangements caused by the replication of integrated HPV16.
[0024] (A) Southern blot analysis of subclones from SiHa cells transfected with 10 μg pMHE1-16 alone (upper panel, lanes 1-43) or together with 5 μg pQMNE2-16 (lower panel, lanes 1-44). Single cell subcloning was performed 72 h after transfection. Total cellular DNA was extracted from each subclone and 3 μg of DNA was digested with BamHI and analyzed by Southern blot with radiolabeled HPV16 URR probe. Total DNA samples from SiHa cells were used for control (lane 44, upper panel; lane 45, lower panel). (B) HindIII, BglII and BamHI restriction analysis of subclones with rearrangements. Restriction pattern of control cells is shown in lanes 25-27. (C) Restriction map of SiHa chromosome 13 close to the HPV16 integration site. Lengths of the appropriate restriction fragments between two sites are depicted in parentheses. (D) Schematic representation of rearrangements at the HPV16 integration site in the third subclone as determined by DIPS-PCR. See Supplementary data for DNA sequence.
[0025] FIG. 7 Genomic instability of host cell induced by the HPV replication machinery.
[0026] Papillomavirus DNA is designated with −, host cell DNA is designated with = and different regions designated with -x-.
DESCRIPTION OF EMBODIMENTS
Example 1
E1 Protein Induces DNA Replication in Cells with Integrated HPV
[0027] Titration of the HPV18 E1 and E2 proteins in the transient assays showed that the efficiency of DNA replication initiation depends on the E1 protein concentration ( FIG. 2A ), while modulation of E2 concentration in a quite wide range had little effect on the efficiency of initiation of the DNA replication of the integrated HPV ( FIG. 2B ). The replication reached a plateau at 0.5 pg of transfected E2 expression plasmid ( FIG. 2B , lanes 6 and 7) and changed little at higher vector concentrations. The E2 expression level in our replication assays did not induce senescence or apoptosis of the transfected cells. High E1 levels caused smearing of the integrated HPV18 origin replication signals characteristic to the ‘onion skin’ type of replication mode. Cleavage of the integrated HPV18 sequences in HeLa cells ( FIGS. 1A , B and E) with BamHI generates a 1 kb URR fragment, which includes the complete functional HPV replication origin and 5.5 kb URR fragment containing nonfunctional origin linked to cellular sequence. The kinetics of accumulation of amplification products with time was studied from 24 h to 96 h after transfection ( FIGS. 2E and F). The amplification level of functional HPV18 URR was estimated up to 90 times at the 72 h time point compared with controls. Moderate amplification of a 5.5 kb fragment was detected at later time points. The amplification of 6-8 kb viral/cellular fragments in the presence of E1 and E2 ( FIG. 2A ) implies that DNA replication from HPV origin can extend into the flanking cellular sequences.
Example 2
Expression of E1 and E2 Proteins Induces Amplification of Episomal and Integrated HPV18 Origins in HeLa Cells
[0028] To test E1 expression constructs and to identify the conditions conducive to viral origin replication, the origin plasmids (pUC/URRs) of all HPVs, together with the homologous expression vectors for E1 and E2, were cotransfected into HeLa cells. The DpnI resistant replication signal from the transient assays was examined by Southern blot analysis of total DNA with common plasmid probe ( FIG. 1A ). Replication of all origin plasmids was clearly detected in HeLa cells. Western blot analysis to monitor E1 protein levels in transfected cells ( FIG. 1D ) confirms its effective and comparable expression in HeLa cells. E2 levels were kept constant and considerably low (5 pg of transfected E2 plasmid) in order to support replication without suppression of E6 promoter. HPV18 and HPV18 E1 proteins seem to be the most efficient in initiation of DNA replication within the used expression range, while HPV6B and HPV11 E1 proteins are clearly less efficient. In addition to the unit-sized plasmid, a smear of newly synthesized products with considerably larger and smaller size than input was detected, especially in the case of HR-HPV replication proteins ( FIG. 1A , lanes 9-12 and 13-16). Probing of the same blots with URR-specific probes showed additional replication signals of different intensity in every lane across the panel ( FIG. 1B , compare with panel A). These signals most probably result from the multiple integrated HPV18 URRs located in at least five different sites of the host genome (Lazo, 1987; Meissner, 1999). It has been demonstrated that also the URR with origin is present in addition to the coding sequences for viral oncoproteins E6 and E7 (schematically shown in FIG. 1E ). According to Lazo and Meissner, the HindIII digest generates three fragments of 8.4 kb ( 1 A), 7.9 kb ( 1 B) and 5.8 kb, carrying HPV18 sequences ( FIG. 1E ). The URR-specific probe for HPV18 detected amplification of exactly these fragments ( FIG. 1B ). The intensities of these bands correlated with the E1 expression levels and were the strongest in the lanes of HR-HPV E1 expression constructs ( FIG. 1B , lanes 9-18). LR-HPV E1 proteins were less efficient for replicating integrated HPV18 origin, which may be explained by lower specificity toward the HPV18 origin, although expression level of the E1 proteins was comparable. Intensive replication signal was detected also in the control lanes, where only the viral expression vectors were transfected, suggesting that integrated HPV18 origin is fully competent for initiation of DNA replication ( FIG. 1B , lanes 17 and 18). These results show that papillomavirus replication proteins are capable of mobilizing integrated HPV origin and that simultaneous DNA replication of episomal and integrated HPV origins may occur in HeLa cells.
Example 3
HPV E1 and E2 Proteins Efficiently Initiate Replication from Integrated HPV16 Origin in SiHa Cells
[0029] SiHa cell line derived from the cervical carcinoma of a 55-year-old Japanese female is aneusomic and has been found to contain 66-72 chromosomes. However, this cell line has been shown to be disomic with respect to chromosome 13, which contains one copy of the HPV16 genome (Meissner, 1999; Szuhai et al., 2000). Integration of the HPV16 genome has occurred, with disruption in the E2 and E4 ORFs at nucleotides 3132 and 3384 of HPV16 genome ( FIG. 3A ). Expression plasmids for the E1 and E2 proteins were transfected into SiHa cells and replication of integrated HPV16 origin DNA was analyzed using HPV16 URR probe. The E2 expression plasmid concentration was kept constant at the level where replication of integrated HPV16 had reached a plateau (data not shown). Increasing amounts of E1 expression plasmids were used in replication assays. In order to reach comparable levels of E1 expression, much higher amounts of HPV6b and HPV11 E1 expression plasmids had to be used in the transfection mixture ( FIGS. 3B and C). The results were interpreted using a previously derived physical map of the integration site of HPV16 (Meissner, 1999), shown schematically in FIG. 3A . Untransfected SiHa cells as well as cells transfected with HPV16 E1 or E2 plasmids alone gave the faint, similar-strength signal of 3.4 kb after the digestion of an equal amount of total DNA samples with Acc65I ( FIG. 3B , lanes 13-15). Cotransfection of the E2 plasmid with increasing amounts of the E1 vector resulted in a significant increase in the HPV16 URR-specific signal in the case of all four HPVs. This indicates that no endogenous expression of functional E1 or E2 protein could be detected in these cells. Expression vectors for the HPV16 (lanes 7-9) and HPV18 E1 proteins (lanes 10-12) induced most efficient initiation of DNA replication of the integrated HPV16 origin when compared with LR-HPV (lanes 1-3) and (lanes 4-6). Remarkably, at higher concentrations of E1 protein of HR-HPVs (lanes 8 and 9, 11 and 12), a heterogeneous mixture of fragments that did not migrate in the gel as a specific band was generated. Analysis of the replication products by 2D gel indicated formation of ‘onion skin’-type replication intermediates and linear dsDNA fragments as shown for BPV1 (Männik et al., 2002) and HPV16 in SiHa (data not shown). This confirms that integrated replication origins of HR-HPV types are functionally active for the HPV E1- and E2-dependent initiation of replication.
Example 4
Estimation of the Size of the Integrated HPV Replicon
[0030] The replication competence of the integrated HPV origins directed by viral replication proteins brings up an intriguing possibility that flanking cellular sequences on both sides of viral integration could be coamplified. We determined the size of the replicon also in SiHa cells by measuring the amplification levels of cellular sequences at various distances from integrated viral DNA replication origin. The HPV16 genome is integrated at chromosome 13q21-31 in SiHa cells. The integrated HPV16 as well as the flanking cellular DNA have been sequenced (Baker et al., 1987; Meissner, 1999). The 50 and 30 flanking cellular DNA sequences, determined by Baker et al., were subjected to BLAST search against the NCBI 36 assembly of human genome (released in November 2005). According to the results, 50 viral-cellular junction in SiHa was located at 72 686 871 by and 30 viral-cellular junction at 72 984 815 by of chromosome 13. This suggests that the distance between these junctional sequences is normally approximately 300 kb, indicating that considerable loss of genomic DNA has taken place in the process of integration of HPV16 DNA. Coordinates of the viral-cellular junctions, determined by BLASTsearch, were used to identify and amplify cellular sequences at various distances from integrated HPV16 using PCR. Sequence blocks with the furthermost nucleotide at 5.4 and 12.6 kb upstream (SL1, SL2 in FIG. 4A ) and 4.7 and 7.9 kb downstream of HPV16 on (SR1, SR2 in FIG. 4A ), together with URR sequence itself, were used as probes in the following quantitative Southern blot analysis. The goal was to determine the amplification level of genomic sequences at different distances on both sides of the integrated HPV origin in SiHa cells, cotransfected with expression plasmids for E1 and E2 proteins of either HPV16 ( FIG. 4B , row 2) or HPV18 ( FIG. 4B , row 3). The control transfection was performed with the carrier DNA alone ( FIG. 4B , row 1). The cellular DNA from transfected cells was digested with appropriate combinations of enzymes (lanes 1-5 in FIG. 4B ; location of restriction sites is depicted in the drawing in FIG. 4A ) and three analogous blots (with SiHa DNA, +HPV16 E1 and E2, and +HPV18 E1 and E2) were probed with four appropriate radiolabeled cellular sequences or URR probe (shown at the bottom of lanes 1-5 in FIG. 4B ). The hybridization signals of two independent experiments were quantified by Phosphorimager and normalized to the carrier-transfected SiHa cells ( FIG. 4A ). The data show that DNA replication, initiated from the HPV16 origin, will extend into the flanking cellular sequences on both sides and that the DNA replication fork travels a distance of at least 12.6 kb from the HPV16 origin, on average, as analyzed at 24 h after transfection. That makes the total size of the amplicon to be more than 25 kb. We estimated that, under the experimental conditions used, the transfection efficiency was approximately 40%. This means that more than half of the signal comes from the cells that do not have E1- and E2-induced amplification. This suggests that at the cellular level amplification as well as the replicon size is likely to be more than the estimated. values. The replication proteins of HPV18 were more efficient in initiating DNA replication of the HPV16 URR compared with HPV16 proteins (solid line compared with dashed line in graph in FIG. 4A ). However, there are almost no differences in the amplification of distal cellular sequences (SL1, SL2, SR1 and SR2) between these sets of replication proteins. Furthermore, we observed that even if the replication of integrated HPV16 origin is highly dependent on E1 concentration ( FIGS. 4C and D), the E1 concentration dependence of amplification of distal sequences decreases with the distance from the replication origin. There was a 10 times difference in the amplification signal of the HPV16 URR when 2.5 or 10 μg of HPV18 E1 plasmid was used, but less than 1.5 times difference in amplifying cellular sequences that are about 10 kb away (SL2 and SR2). These data suggest that overexpression of E1 protein may generate replication intermediates, locked for elongation, owing to the topological constraints in the ‘onion skin’ structures that would prevent traveling of replication forks further into the genome. Therefore, elongation of replication forks at considerable distances from the initiation site is determined presumably more by proper configuration of the template and replication complex functioning at it and less by the E1 level. These data also suggest that low E1 and E2 protein levels, for example from episomal HPV genome, and respective extension of the E1-driven replication into the flanking sequences may be highly relevant for induction of amplification of the HPV integration locus in HPV-infected cells.
Example 5
Coreplication of Integrated and Episomal HPV18 in HeLa Cells
[0031] HeLa cells were transfected with the plasmid carrying functional full-size HPV18 genome cloned into pUC19 plasmid. Extrachromosomal supercoiled plasmids from the transfected cells were extracted at certain time points by alkaline lysis. Analysis of the episomal replication products (provided in FIG. 5A ) shows that DpnI-resistant and HindIII-linearized HPV replication induced genomic instability HPV18 viral genome replication could be detected in HeLa cells at low level ( FIG. 5A , lanes 2 and 3), indicating that viral genome is basically functional and directs the expression of E1 and E2 replication proteins in some cells, although at low level. Cotransfection of HPV18 plasmid with E2 expression vector did not increase replication signal (data not shown); however, cotransfection of E1 expression vector with HPV18 genome considerably increased the replication signal of episomal HPV18 genome as well as showed a clear increase in the signal from integrated HPV18 sequences, especially at later time points ( FIG. 5A , lanes 4 and 5). This suggests that expression of E2 protein from the viral genome is sufficient to support E1-driven initiation of DNA replication of episomal as well as integrated HPV18 replication origins in HeLa cells. Detection of a clear, strong and increasing-in-time replication signal of the integrated HPV18 HindIII fragments in the extrachromosomal fraction suggests that excision of replicating integrated HPV18 sequences from the chromosomal DNA occurs, which is further followed by extrachromosomal replication of these plasmids. Cotransfection of HPV18 genome with E1 and E2 expression vectors tremendously increased HPV18 DNA replication ( FIG. 5 , lanes 6 and 7). The smear detected in the Southern blots is presumably caused by single-stranded DNA fragments extracted from the ‘onion skin’ replication intermediates during alkaline extraction. The control experiment, where pUCURR18 plasmid was used, showed replication signal only in the presence of E1 and E2 proteins ( FIG. 5 , lanes 8 and 9 compared with 10 and 11), as expected. Analysis of total genomic DNA from the same transfection after 48 h is presented in FIG. 5B . A relatively smaller fraction of cells was analyzed in this blot and it shows that without isolation of episomal DNA, the replication of HPV18 DNA is detected only in the case of cotransfection with E1 and E2 expression vectors ( FIG. 5B , lanes 2, 3 and 5). In order to evaluate the ability of the HPV18 genome to mobilize the integrated replication origin, we cotransfected cloned HPV18 genome together with EGFP expression vector (pEGFP-N1) into HeLa cells. The EGFP-positive cells were isolated using cell sorter FACS-ARIA 48 h after transfection. This allowed us to analyze only the transfected cells and remove background of integrated HPV sequences of untransfected cells. Total cellular DNA was digested with HindIII/DpnI and analyzed by Southern blotting. First, we showed an increase in the average apparent copy number of input episomal HPV18 plasmid by four-fold, from 40 to 170 per cell, as estimated by the intensity of the URR containing DpnI fragment ( FIG. 5C ). We reproducibly succeeded in detecting the replication of episomal HPV18 plasmid at the level of eight copies per cell. Most importantly, we also detected amplification of integrated HPV18 sequences by two-fold in these cells ( FIG. 5C , lane 3 and D, third bar). These data suggest that E1 and E2 proteins, expressed from the native context of the HPV18 genome in HeLa cells, initiate episomal DNA replication and also endogenous levels of these proteins produced from the episomal genome are sufficient for mobilization of the integrated HPV origin locus for unscheduled replication. These data provide experimental proof for the hypothesis that similar amplification of the integrated HRHPV sequences could occur in HPV-infected cells as in LG-SIL and HG-SIL cells if episomal HPV genomes producing replication proteins are present.
Example 6
Replication from Integrated HPV16 Origin Will Cause Chromosomal Rearrangements in SiHa Cells
[0032] Amplified HPV locus in SiHa cells is the potential target for repair/recombination machinery that may result in chromosomal alterations. The cells transfected with low amounts of HPV16 E1 and E2 expression plasmids were single cell subcloned 72 h after transfection. The subclones were expanded, total DNA was extracted and purified, and the HPV16 integration patterns of subclones were analyzed by Southern blot analysis using URR probe. Alterations in the restriction pattern of the integrated HPV16 locus could be detected only in cases when at least one of the cleavage sites for specific restriction enzyme is outside of the DNA fragment that was involved in rearrangement. Therefore, BamHI cleavage, which generates 21.5 kb DNA fragment from 1.8 kb upstream to B20 kb downstream of HPV16 URR, was used ( FIG. 6C ). Analysis of 43 tested subclones, generated after transfection with the E1 expression plasmid alone, did not reveal any changes in the BamHI restriction pattern ( FIG. 6A , upper panel). However, eight out of 44 subclones isolated from E1- and E2-transfected cells contained a novel HPV16 restriction pattern (lower panel in FIG. 6A , lanes 3, 8, 13, 15, 24, 27, 36 and 39), representing either an internal rearrangement or reintegration at a novel site. Additional analysis of these subclones with HindIII and BglII (sites in the scheme of FIG. 6C ) confirmed the rearrangement of the HPV16 URR containing sequences and showed that every subclone resulted from the individual event of repair/recombination ( FIG. 6B ). Thus, cells can survive the considerable changes induced by the HPV DNA replication machinery, which results in effective rearrangement of the genomic DNA. More precise analysis of one of the subclones ( FIG. 6B , lanes 1-3) by DIPS-KR suggests that in situ duplication of HPV16 genome together with 30 cellular DNA ( FIG. 6D ) has occurred. We determined that the nucleotide 190 of chromosome 13 from the 30 end of initially integrated HPV16 has been linked to nucleotide 3852 (within the E2 stop codon) of the HPV16 genome. Sequence homology could not be found between these sites, indicating that illegitimate recombination has taken place.
[0033] It is believed that the methods and examples shown or described above have been characterized as preferred, various changes and modifications may be made therein without departing from the scope of the invention as defined in the following claims.
Materials and Methods
[0034] Plasmids
[0035] Plasmids pQMNE2-6b, -11, -16 and -18 were prepared by cloning E2 ORFs from HPV6b (2723-3829 nt), -11 (2723-3826 nt), -16 (2756-3853 nt) and -18 (2817-3914 nt) into the multicloning site of eukaryotic expression vector pQM-NTag/Ai+(Quattromed Ltd) followed by deletion of intron. The pUCURR-6b, -11, -16 and -18 plasmids were cloned by inserting viral sequences containing the URR region of HPV6b (7292-101 nt), -11 (7022-94 nt), -16 (6361-282 nt) and -18 (6929-124 nt) into the multicloning site of pUC-19 plasmid. pMHE1-6b, -11, -16 and -18 vectors contained E6, E7 and E1 ORFs from HPV6b (102-2781 nt), -11 (102-2781 nt), -16 (83-2814 nt) or -18 (105-2887 nt) that were directed by CMV promoter in the pQM-NTag/Ai+vector with deleted intron and 3F12 epitope tag. Initiation codons for E6 and E7 oncogenes were deleted. The major splice donor site (AGGT) at the beginning of E1 ORFs was disrupted by inserting influenza hemagglutinin epitope tag (HA) inframe into the E1 coding sequence. The inserted HA tag had no effect on the E1 protein activities. Additional point mutation was introduced into the splicing acceptor site of HPV11 E1 ORF (2622 nt), (ACA-ACC), and this did not change the coding capacity. pUCHPV18 wt were cloned by inserting EcoRV-linearized HPV-18 genome (4670 nt within L2) into pUC19 SmaI site.
[0036] Cell Lines and Transfection
[0037] HeLa and SiHa cells were grown in Iscove's modified Dulbecco's medium (IMDM) supplemented with 10% fetal calf serum. Electroporation experiments were carried out as described by Ustav and Stenlund, 1991, using the Bio-Rad Gene Pulser II apparatus supplied with a capacitance extender (Bio-Rad Laboratories, USA). Capacitance was set to 975 mF and voltage to 220V in all experiments. Cells were plated onto 60 mm dishes and harvested at different time points.
[0038] Transient Replication Assays
[0039] Low-molecular-weight DNA was purified by alkaline lysis as described by Ustav and Stenlund, 1991. Total DNA was extracted from cells (FM Ausubel et al., 1998). DNA digested with appropriate enzymes was resolved in 0.5 or 0.8% agarose gel, blotted and hybridized with appropriate 32P-labeled probe generated by random priming (DecaLabel kit, Fermentas, Lithuania). The cellular sequences (SL1, SR2, SL1 and SL2) used in hybridization were amplified from SiHa genomic DNA with PCR using Taq polymerase and primers that were designed with the programs Primer3 (Rozen and Skaletsky, 2000) and GenomeTester (Andreson et al., 2006). Radioactive signals were quantified using ImageQuant software of PhosporImager SI (Molecular Dynamics, Amersham Biosciences, UK).
[0040] Immunoblotting
[0041] Total protein from an equal number of cells was separated by electrophoresis on 10% polyacrylamide-SDS gels and transferred to Immobilon-P membrane (Millipore, USA). Antibodies 3F10-HRP (Roche) and 4E4 were used to detect E1 and E2 proteins using the enhanced chemoluminescence detection kit (Amersham Biosciences).
[0042] Cell Sorting
[0043] For cell sorting, cells were cotransfected with pEGFP-N1 (Clonetech) and pUCHPV18 wt plasmids. Forty-eight hours after transfection, the transfected cells were sorted on the basis of EGFP fluorescence using the FACSDiva software and the FACSAria hardware (Becton Dickinson) equipped with a 13 mW argon ion laser set at 488 nm with a 530/30 nm filter. The purity of EGFP+cells, when reanalyzed, was 90±5%.
[0044] DIPS-PCR
[0045] DIPS-PCR assay was performed as described previously (Luft et al., 2001). The ds adapter was constituted from AS1 (5′-PO 4 -gatccaacgtgtaagtctg-NH 2 ) (SEQ. ID NO. 1) and AL1 (5′-gggccatcagtcagcagtcgtagccggatccagacttacacgttg-3′) (SEQ. ID NO. 2) DNA oligos. The primers used in PCR were AP1 (5′-ggccatcagtcagcagtcgtag-3′) (SEQ. ID NO. 3) and S1 (5′. agggaatcccaatgaaggac-3′) (SEQ. ID NO. 4). PCR products were analyzed by 1.2% agarose gel electrophoresis followed by purification of the product of interest and sequence determination. | The invention relates to a method for introducing changes into a eukaryotic genome in vivo wherein the HPV genome, which comprises HPV replication origin sequence, is used together with HPV early proteins in order to achieve DNA replication in vivo. There is also disclosed a kit for in vivo amplification, excision, translocation and/or inversion of a DNA sequence, which comprises a vector carrying HPV genome or a part of HPV genome including HPV replication origin sequence, and expression vector or vectors encoding HPV early proteins. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a logging into place tool. More particularly, the present invention relates to a logging into place tool having a gamma-ray tool and an electromagnetic telemetry tool attached to a drill stem test string.
2. Background of the Related Art
A drill-stem test (DST) system is commonly used in connection with hydrocarbon exploration and exploitation. The primary purpose of the DST is to obtain a maximum stabilized reservoir pressure, a stabilized flow rate, and representative samples formation fluids and gasses. The hydrocarbon reservoir's potential is evaluated utilizing various reservoir engineering calculations and the collected data/information.
Drill stem test systems commonly have a multi-section housing which contains or supports a number of test-related devices, which collectively may be referred to as the drill stem test tool or DST tool. The housing sections are formed with internal conduits which, when the housing sections are assembled, co-operate to define a network of fluid flow paths required for the testing procedure. The housing sections are assembled at the surface and then lowered on the end of the drill string (e.g., drill pipes or tubings) to the desired test depth corresponding to a prospective zone of interest.
Inflatable (or otherwise expandable) packers carried by certain of the housing sections engage the wellbore to isolate a test region. A single packer may be provided if only the bottom of the wellbore is to be tested, but it is common practice to provide a pair of packers which permit a test region intermediate of the top and bottom of the wellbore to be isolated.
For conventional testing, weight may be set down on the drill string to expand the packers against the wellbore. For inflate testing, a pump may be positioned in the drill-stem test string to pump wellbore drill fluid (commonly referred to as “mud”) into the packers for inflation. Once the packers are set, a test valve is opened to introduce a flow of fluid from the test region into one of the channels formed in the drill stem test string. Upon completion of the initial flow period, the test valve is then closed (i.e., shut-in) to allow the formation to recover and build back to its original shut-in pressure. Repetitive flows and shut-ins are routinely performed to gather additional reservoir evaluation data. The drill stem test system is then retrieved to permit interpretation of the recorded pressure and temperature data and analysis of the fluids and/or gas samples trapped by the DST tool during the flow period.
Typically, the DST tool is conveyed downhole using tubing or drill-pipe to a prospective zone of interest based upon previously measured depth and formation correlation from open hole wireline logs, e.g., a gamma-ray well log. However, during the process of conveying the DST tool with tubing or drill-pipe, improper or inaccurate measurements of the length of the drill string may take place due to inconsistent lengths of collars and drill-pipes, pipe stretch, pipe tabulation errors, etc., resulting in erroneous placement of the DST tool. Thus, DST tests may be performed in the wrong zone of interest, and incorrect decisions may result as to whether the formations being tested is a hydrocarbon-bearing formation. Furthermore, repeating the drill-stem test may be very costly both in expenses and time.
Therefore, a need exists for an apparatus and method for accurately logging a drillstem test tool into place as the DST tool is conveyed by drill pipe or tubing to the desired location.
SUMMARY OF THE INVENTION
Apparatus and method for accurately logging a drill-stem test (DST) tool into place as the DST tool is conveyed by drill pipe or tubing to the desired location are provided.
One aspect of the invention provides an apparatus for logging into place a drill stem test tool, comprising: a drill string comprising drill pipes or tubings; a drill stem test tool disposed on the drill string; an electromagnetic telemetry tool disposed on the drill string; and a gamma ray tool connected to the electromagnetic telemetry tool.
Another aspect of the invention provides a method for logging into place a drill stem test tool disposed on a drill string, comprising: lowering a drill stem test tool, an electromagnetic telemetry tool and a gamma ray tool disposed on a drill string into a wellbore; producing a partial log utilizing the gamma ray tool while the drill stem test tool is moved adjacent a correlative formation marker; compare the partial log to a well log to determine a depth position adjustment; and adjust a position of the drill stem test tool according to the depth position adjustment.
Another aspect of the invention provides an apparatus for testing a well, comprising: a downhole system comprising a drill stem test tool disposed on a drill string and an electromagnetic telemetry tool having a gamma ray tool disposed on the drill string; and a surface system comprising a controller disposed in communication with the downhole system.
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 schematic diagram of a well testing system incorporating a drill stem test tool, an electromagnetic telemetry tool having a gamma ray tool according to the invention.
FIG. 2 is a schematic diagram of an electromagnetic telemetry tool having a gamma ray tool according to the invention.
FIG. 3 is a schematic diagram of one embodiment of a test string incorporating an inflate straddle drill stem test tool having an electromagnetic telemetry tool and a gamma ray tool according to the invention.
FIG. 4 is a schematic diagram of another embodiment of a test string incorporating an inflate bottom hole drill stem test tool having an electromagnetic telemetry tool and a gamma ray tool according to the invention.
FIG. 5 is a schematic diagram of one embodiment of a well testing system having a downhole system and a surface system.
FIG. 6 is a flow diagram illustrating one embodiment of a method for logging into place a drill stem test tool according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a schematic diagram of a well testing system incorporating a drill stem test tool, an electromagnetic telemetry tool having a gamma ray tool according to the invention. The gamma ray tool and the electromagnetic telemetry tool instrumentation may be encapsulated in a pressure housing mounted within a drill-stem test tool. The well testing system 100 generally comprises a surface unit 110 and a downhole test string 120 . The surface unit 110 may include one or more processors, computers, controllers, data acquisition systems, signal transmitter/receiver or transceivers, interfaces, power supplies and/or power generators and other components. In one embodiment, the surface unit 110 is housed in a mobile truck. An antenna 112 , such as a metal ground stake or other receiving instrumentation may be disposed or driven into the ground and connected to the surface unit 110 to receive and/or transmit signals to and/or from components in the downhole test string 120 . In one embodiment, the antenna 112 is disposed at about 100 feet (radial distance) away from the surface unit 110 with another connection from the surface unit 110 to the Blow Out Preventor (BOP) or other electrically conductive path to the drill string. The downhole string 120 includes a plurality of drill-pipe or tubing 122 , an electromagnetic telemetry tool having a gamma ray tool attached thereon 124 , one or more packers 126 and a drill stem test (DST) tool 128 . The plurality of drill-pipe or tubing 122 are connected from the surface to extend to the other components of the test string downhole. The electromagnetic telemetry tool 124 includes a transceiver for communicating with the surface unit 110 . The one or more packers 126 provide a sealed section of the zone of interest in the wellbore to be tested.
FIG. 2A is a schematic diagram of an electromagnetic telemetry tool having a gamma ray tool according to the invention. The electromagnetic telemetry tool 124 generally includes a pressure and temperature sensor 210 , a power amplifier 220 , a downlink receiver 230 , a central processing unit 240 , a gamma ray tool 250 , and a battery unit 290 . The electromagnetic telemetry tool 124 is selectively controlled by signals from the surface unit to operate in a pressure/temperature sensing mode which provides for a record of pressure versus time or in a gamma ray mode which records gamma counts as the DST tool is raised or lowered past a correlative formation marker. The record of gamma counts is then transmitted to surface and merged with the surface system depth/time management software to produce a gamma-ray mini-log which is later compared to the wireline open-hole gamma ray log to evaluate the exact drill stem test tool depth.
The gamma ray tool 250 , shown in FIG. 2B, includes a radiation detector 258 for detecting naturally occurring gamma radiation from the formation. The detector 258 is of a type appropriate to the detection of gamma radiation and the production of an electrical signal corresponding to each detected gamma ray and having an amplitude representative of the energy of the gamma ray. The detector 258 includes a scintillation crystal or scintillator 260 which is optically coupled to a photomultiplier tube (PMT) 262 . The scintillator 260 may comprise a gadolinium-containing material, such as gadolinium orthosilicate that is suitably doped, for example with cerium, to activate for use as a scintillator. The quantity of cerium in terms of number of atoms is typically of the order of about 0.1% to about 1% of the quantity of gadolinium. The scintillator may comprise other materials, such as sodium iodide doped with thalium (Nal)(Tl), bismuth germanate, cesium iodide, and other materials.
Electrical power for the gamma ray tool 250 is supplied from the battery unit 290 . The gamma ray tool 250 includes power conditioning circuitry (not shown) for feeding power at appropriate voltage and current levels to the detector 258 and other downhole circuits. These circuits include an amplifier 268 and associated circuitry which receives the output pulses from photomultiplier tube (PMT) 262 . The amplified pulses are then applied to a pulse height analyzer (PHA) 270 which includes an analog-to-digital converter which may be of any conventional type such as the single ramp (Wilkinson rundown) type. Other suitable analog to digital converters may be used for the gamma ray energy range to be analyzed. Linear gating circuits may also be employed for control of the time portion of the detector signal frame to be analyzed. Improved performance can be obtained by the use of additional conventional techniques such as pulse pile-up rejection.
The pulse height analyzer 270 may assign each detector pulse to one of a number (typically in the range 256 to 8000) of predetermined channels according to its amplitude (i.e., the gamma ray energy), and produces a signal in suitable digital form representing the channel or amplitude of each analyzed pulse. Typically, the pulse height analyzer 270 includes memory in which the occurrences of each channel number in the digital signal are accumulated to provide an energy spectrum. The accumulated totals are then transferred via a buffer memory 272 (which can be omitted in certain circumstances) to the telemetry interface circuits 274 for transmission to the surface equipment.
At the surface, the signals are received by the signal processing circuits, which may be of any suitable known construction for encoding and decoding, multiplexing and demultiplexing, amplifying and otherwise processing the signals for transmission to and reception by the surface equipment. The operation of the gamma ray tool 250 is controlled by signals sent downhole from the surface equipment. These signals are received by a tool programmer 280 which transmits control signals to the detector 258 and the pulse height analyzer 270 .
The surface equipment includes various electronic circuits used to process the data received from the downhole equipment, analyze the energy spectrum of the detected gamma radiation, extract therefrom information about the formation and any hydrocarbons that it may contain, and produce a tangible record or log of some or all of this data and information, for example on film, paper or tape. These circuits may comprise special purpose hardware or alternatively a general purpose computer appropriately programmed to perform the same tasks as such hardware. The data/information may also be displayed on a monitor and/or saved in a storage medium, such as disk or a cassette. The surface system may also include a depth-measuring system for measuring a depth position of the drill string/tubing or a component on the drill string.
FIG. 3 is a schematic of one embodiment of a test string incorporating an inflatable straddle, drill stem test tool having an electromagnetic telemetry tool and a gamma ray tool according to the invention. The test string 300 includes a plurality of drill pipe sections 302 that extend from the surface. A plurality of components may be attached to the test string to perform the drill stem test for particular well conditions. For example, the test string may comprise an inflatable straddle assembly for testing a particular section of the wellbore. In one embodiment, as shown in FIG. 3, the test string 300 includes the following components connected in order downward from the drill pipe sections 302 ; first drill collars 304 , a reversing sub 306 , second drill collars 308 , a pressure activated reverse circulating sub 310 , a cross over sub 312 , a fluid recovery recorder 314 , a hydraulic main valve 316 , a reservoir flow sampler 318 , an inside recorder carrier 320 , an electromagnetic telemetry tool with a gamma ray tool 322 , hydraulic jars 324 , a safety joint 326 , a pump 328 , a screen sub 330 , a valve section 332 , a back-up deflate tool 334 , a first inflatable packer 336 , a recorder carrier and flow sub 338 , a hanger sub 340 , a drill collar spacer 342 , a bypass receiver sub 344 , a second inflatable packer 346 , a clutch drag spring unit 348 , an electronic or mechanical recorder 350 , and a bull nose 352 . The embodiment shown in FIG. 3 may be modified to include additional components or detail as needed for particular types of tests. Also, additional packers may be disposed adjacent the packers 336 and/or 346 to provide enhanced seal to the wellbore.
FIG. 4 is a schematic diagram of another embodiment of a test string incorporating an inflate bottom hole drill stem test tool having an electromagnetic telemetry tool and a gamma ray tool according to the invention. In the embodiment shown in FIG. 4, the test string 400 comprises an inflatable bottom hole assembly for testing a bottom section of the wellbore. The test string 400 includes the following components connected in order downward from drill pipe sections 402 ; first drill collars 404 , a reversing sub 406 , second drill collars 408 , a pressure activated reverse circulating sub 410 , a cross over sub 412 , a fluid recovery recorder 414 , Hydraulic Main Valve 416 , a reservoir flow sampler 418 , an inside recorder carrier 420 , an electromagnetic telemetry tool with a gamma ray tool 422 , hydraulic jars 424 , a safety joint 426 , a pump 428 , a screen sub 430 , a valve section 432 , a back-up deflate tool 434 , one or more inflatable packers 436 , a recorder carrier 438 and flow sub 439 , a drag spring extension sub 440 , a drill collar spacer 442 , a clutch drag spring unit 448 , an electronic or mechanical recorder 450 , and a bull nose 452 .
FIG. 5 is a schematic diagram of one embodiment of a logging into place system. The logging into place system 500 includes a downhole system 510 and a surface system 530 . In relation to the embodiment shown in FIG. 1, and the downhole system 510 includes the downhole test string 120 as shown in FIG. 1 . Referring to the block diagram in FIG. 5, the downhole system 510 includes a drill stem test string 511 , a gamma-ray tool 512 , central processing unit 514 , a modulator 516 , a pre-amplifier 518 , a power amplifier 520 , and a transmitter/receiver 522 . One or more of these components may be housed in the telemetry tool 124 (in FIG. 1 ). The DST string 511 provides for mechanical manipulation at surface to open and close downhole valves and also allow for surface manipulation in order to inflate the downhole pump in order to inflate packers against the wellbore. Housed within the DST string is the electromagnetic telemetry system with a gamma ray tool controlled by signals transmitted from the surface system. A command is transmitted from surface to downhole to start recording and storing to memory a record of gamma counts as the tool is conveyed up or down past a correlative marker (formation). As time and conveyed depth measurements are stored at surface by the surface system, the measurements are correlated to the downhole gamma counts after being transmitted. A mini gamma ray log is generated and compared to the wireline open-hole for drill-pipe conveyed depth versus the log depth from the original wireline open hole log. The DST tool is then positioned up or down relative to the correlated measured depth from the open hole log.
Communication between the downhole system 510 and the surface system 530 may be achieved through wireless electromagnetic borehole communication methods, such as the Drill-String/Earth Communication (i.e.: D-S/EC) method. The D-S/EC method utilizes the drill string or any electrical conductor, such as the casing or tubing and the earth as the conductor in a pseudo-two-wire-transmission mode.
The surface system 530 includes a receiving antenna 531 , a surface transmitter/receiver 532 , a preamplifier/filter 534 , a demodulator 536 , a digital signal processor 537 , a plurality of input/output connections or I/O 538 , and a controller 540 . The controller 540 includes a processor 542 , and one or more input/output devices such as, a display 546 (e.g. Monitor), a printer 548 , a storage medium 550 , keyboard 552 , mouse and other input/output devices. A power supply 554 and a remote control 556 may also be connected to the input/output 538 .
FIG. 6 is a flow diagram illustrating one embodiment of a method 600 for logging into place a DST tool according to the invention. To begin the logging into place method 600 , the DST tool is conveyed downhole into the wellbore with the electromagnetic telemetry tool and gamma ray tool. A plurality of drill pipes or tubings are connected onto the drill string until the measured depth is reached. (step 610 ) As the drill string is lowered into the wellbore past the prospective correlative formation, the tool is stopped and a downlink command from the surface system is sent ordering the gamma ray tool to start recording data to memory. (step 620 ) The drill string is then raised, for example, at a rate of approximately 5 meters per minute, to record gamma counts as the gamma ray tool passes by differing lithologies. After a distance of approximately 30 meters has logged, the complete record of downhole gamma counts is transmitted to surface. (step 630 ) A partial log (or mini log) is generated by merging the recorded surface depth/time records with the downhole gamma count record. (step 640 ) The partial log is then compared to a previously produced well log (e.g., open-hole gamma-ray log) and correlated to the same marker formation. (step 650 ) As the open hole gamma-ray log is considered correct, a depth position adjustment, if necessary, is calculated based on the comparison of the partial log to the open hole gamma-ray log. The drill-string is moved up or down by adding or removing drill pipe(s) or tubing(s) to adjust the position of the DST tool. (step 660 ) After the DST tool has been logged into place at a correct depth, the drill stem test may commence.
The drill stem test provides reservoir data under dynamic conditions, including stabilized shut-in formation pressures, flow pressures and rates. The DST also records temperature measurements and collects representative samples of the formation fluids. Additionally, the drill stem test also provides for data to calculate reservoir characteristics including but not limited, to permeability, well bore damage, maximum reservoir pressure, reservoir depletion or drawdown, radius of investigation, anomaly indications, and other qualitative and quantitative information regarding the well.
While the foregoing is directed to the preferred embodiment of thee present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | Apparatus and method for accurately logging a drill-stem test tool into place as the DST tool is conveyed by drill pipe or tubing to the desired location are provided. One aspect of the invention provides an apparatus for logging into place a drill stem test tool, comprising: a drill string comprising drill pipes or tubings; a drill stem test tool disposed on the drill string; an electromagnetic telemetry tool disposed on the drill string; and a gamma ray tool connected to the electromagnetic telemetry tool. Another aspect of the invention provides a method for logging into place a drill stem test tool disposed on a drill string, comprising: lowering a drill stem test tool, an electromagnetic telemetry tool and a gamma ray tool disposed on a drill string into a wellbore; producing a partial log utilizing the gamma ray tool while the drill stem test tool is moved adjacent a correlative formation marker; compare the partial log to a well log to determine a depth position adjustment; and adjust a position of the drill stem test tool according to the depth position adjustment. | 4 |
BACKGROUND OF THE INVENTION
In an injection stretching blow molding machine disclosed, for example, in the present inventor's U.S. Pat. No. 4,105,391, wherein a rotary disk is provided on the under-side of a base plate, the required number of neck molds are attached to the under-surface of and parallel to a tangent line of the rotary disk, and an injection molding mold, a temperature control member and a blow mold are disposed between the rotary disk and a machine bed, whereby when the rotary disk is stopped, the steps of injection molding parisons, temperature controlling, stretching blow molding hollow molded products and releasing are carried out. The blow mold and a mold closing mechanism are located between the rotary disk and a lower base plate which forms a part of the machine bed. This blow mold is opened and closed in a diametrical direction of the rotary disk by a mold opening and closing mechanism secured to the lower base plate, and in the state where the mold is open, laterally receives the neck mold parallel to the tangent line. When the rotary disk is stopped, the mold is closed by the mold opening and closing mechanism from both sides of the neck mold.
However, where a plurality of neck molds are provided, they are arranged in a linear fashion, and the neck molds and parisons held thereon are transported in the form of circular motion, and thus, the distance that the blow molds must be moved into their open positions becomes great in order to prevent them from contacting the blow molds. Further, the opening and closing mechanism for the blow molds is merely secured to the lower base plate, which mechanism is a mechanism uncapable of installing a tie bar to receive a mold closing reaction, that is, a reaction relative to the mold closing being a cantilever mechanism, and therefore, the mold closing force in an upper portion close to the neck mold is inevitably weak and in blow molding, the upper portion of the blow mold tends to open more than the lower portion thereof, which poses a disadvantage in that a parting line of the upper portion of a molded product becomes somewhat thick.
BRIEF SUMMARY OF THE INVENTION
It is, therefore, the primary object of the present invention to eliminate the above-discribed disadvantages caused to occur in the injection molding machine which was previously invented by the present inventor.
Another object of the present invention is to provide a new and improved injection stretching blow molding machine in which a rotary disk may be operated without any inconvenience even if neck molds, blow molds and the like are disposed in the form of a two-row. PG,4
A further object of the present invention is to provide an extremely economical injection stretching blow molding machine which can produce materially numerous synthetic resin bottles or hollow molded articles as compared with the above-mentioned prior art molding machine only by increasing the diameter of the rotary disc to a certain extent.
That is, the opening distance of the blow mold is set to a distance slightly greater than the diameter of a molded article, the mold opening and closing mechanism is provided with a support rod for supporting upper and lower portions of the mold, the blow mold so designed as to apply a balanced mold closing force to upper and lower portions and the opening and closing mechanism thereof are moved down to a position so that they may not contact with the neck molds, parisons held thereon and molded articles when the latter are transported, the blow molds are elevated until they may register with the neck molds when the neck molds and the like are completed to be transported and the parisons are stopped at the blowing position, the parisons are subjected to stretching and blowing, after which the molds are open to a degree slightly greater than the diameter of the molded article, and the blow molds and the opening and closing mechanism thereof are moved down to a position not to interfere with the transportion of the molded articles.
With such a mechanism as described above, a small mold opening distance will suffice, and a spacing between two rows of the mold opening and closing mechanisms arranged in two rows can be designed small and as a result, it becomes possible to install two rows of neck molds on a rotary disk having a reltively small diameter. Further, the injection molds, the temperature control member, the blow molds and the molded article releasing member may be installed in positions corresponding to the neck molds, and two rows of hot runners disposed under the injection molds may be connected by means of a connecting member. Thus, if molds for obtaining 10 articles are arranged in one row, twenty articles may be obtained in two rows, that is, this results from an arrangement to make it possible to design a volume manufacturing machine which can obtain twenty molded articles in one cycle.
In accordance with the aspects of the present invention, the injection blow molding machine comprises: a machine bed having four operation portions of an injection molding portion, a temperature control portion, a stretching and blowing portion and a releasing portion; a base plate which is attached with its peripheral portions in parallel to and above the machine bed; a rotary disk which is rotatably attached to the under-surface of the base plate and being provided with neck molds; a drive means secured to the middle portion of the base plate to rotate the rotary disk intermittently to the respective operation portions; a mold opening and closing mechanism, a temperature control mechanism, a stretching and blowing mechanism and a molded product releasing mechanism which are secured on the base plate and positioned respectively in the above injection molding, temperature control, stretching and blow molding, and molded product releasing portions; an injection mold disposed on the lower-side of the rotary disk movably up and down; a temperature control member; blow molds and injection mold opening and closing mechanism.
The aforementioned blow molds and the opening and closing mechanism are composed of a bed plate disposed movably up and down within the machine bed, a blow mold device mounted internally of a pair of mold opening and closing mechanisms and positioned on the bed plate leaving a predetermined space and provided with two sets of blow molds, which are movable in a horizontal direction on the base plate, corresponding to neck molds, and a stretching and blowing device positioned on said base plate.
Further, the aforementioned operation mechanisms are actuated by means of their respective drive mechanisms when the rotary disk is stopped at the predetermined position. The injection mold opening and closing mechanism is provided with parison cores, which are inserted into the cavities of the elevated injection molds. The temperature control mechanism is provided with temperature control cores, which are inserted into the temperature control member. The stretching and blowing mechanism is provided with stretching and blowing cores, which are inserted into the elevated blow molds.
Furthermore, the aforementioned blow molds and the mold opening and closing mechanism thereof move up to a predetermined height when the rotary disk is in its stopped state and parisons are being molded in the injection molding stage, and then the molds are closed and the stretching and blowing cores are inserted.
Elevating means used for the above-described respective cores, the blow molds and the mold opening and closing mechanism may include air or hudraulic mechanism, and drive means for the rotary disk may include an electric motor and reduction gear or a torque actuator, a hydraulic motor or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
The injection stretching and blow molding machine in accordance with the present invention is without showing the detailed portions illustrated in the accompanying drawings, in which:
FIG. 1 is a longitudinal sectional view of an injection molding portion and a stretching and blow molding portion when the molds are closed;
FIG. 2 is a plan view of a rotary disk and a base plate is shown by a chain line;
FIG. 3 is a plan view of a hot runner block; and
FIG. 4 is a longitudinal sectional view of an injection molding portion and a stretching and blow molding portion when the molds are open.
FIG. 5 is a longitudinal sectional view of a temperature control portion and a releasing portion of molded articles when the molds are open.
FIG. 6 is a plan view of a means of the molds for blow molding.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The specific embodiment of the present invention will now be described in detail in conjunction with the accompanying drawings.
A base plate 1 is horizontally disposed above a machine bed 2 leaving a predetermined space. A rotary disk 5 is fitted to the under-surface of the base plate 1, and is turned through 90 degree increments via a rotary shaft 4 by means of an actuator 3 positioned in the middle portion of the base plate.
To four sides of the under-surface of the rotary disk 5 are fitted a plurality of neck molds 6, which mold neck portions of hollow molded products such as bottles, parallel to a tangent line of the rotary disk 5.
As shown in FIG. 2, each neck mold 6 comprises an element in which a pair of rectangular die plates of a sectional die are joined by means of a spring 7 and a guide pin 8, and the mold is opened in a radial direction of the rotary disk 5 by a wedge 9 inserted into a seam of the sectional die. While two sets of neck molds 6, 6 are arranged in four sides in the illustrated embodiment, it should be noted that the neck molds 6 can be arranged in one row.
On the four sides of the rotary disk 5, there are formed an injection molding stage A, a temperature control stage B, a stretching and blow molding stage C and a molded product releasing stage D, and the rotary disk 5 is stopped at a position where each pair of neck molds 6, 6 faces a respective stage, so that during the stoppage of the rotary disk, the respective steps of molding, temperature controlling, and releasing are carried out.
The injection molding stage A is composed of a mold closing mechanism 10 provided on the machine bed 2, and a core mold closing mechanism 12 connected to the mold closing mechanism 10 by means of a tie bar 11 (FIG. 4) and positioned on the base plate 1. The mold closing mechanism 10 has a hot runner block 13 and two sets of injection molds 14 corresponding to the neck molds 6, 6 mounted thereon.
The core mold closing mechanism 12 has a core 15 mounted downwardly thereon which extends through the base plate 1, the rotary disk 5 and the neck molds 6, 6 and accommodated in the center of the closed injection mold 14. The molten resin from the injection device 16 passes through the hot runner block 13 and is poured into the cavity formed by the core 15 (FIG. 4) to form a bottomed parison 17 in the periphery of the core.
Next, the stretching and blow molding stage C is composed of a bed plate 18 provided movably up and down within the machine bed 2, a blow mold device 21 mounted internally of a pair of mold opening and closing mechanisms 19, 19 disposed on the bed plate leaving a predetermined space and provided with two sets of blow molds 20, 20 horizontally movable above the bed plate 18 corresponding to the neck molds 6, 6, and a stretching and blowing device 22 disposed on the base plate 1.
The mold opening and closing mechanisms 19, 19 are composed of a pair of fixed plates 19a, 19a opposedly provided on the bed plate 18, a plurality of guide bars 23, 23 horizontally provided over the fixed plates, two sets of mold mounting plates 24, 25 and a movable plate 19b movably supported on the guide bars, a hydraulic cylinder 26 directly connected to the external mold mounting plate 24, a piston 27 connected to the movable plate 19b, and a tension rod 19c provided over the internal mold mounting plate 25 and the movable plate 19b (see FIG. 6). The aforementioned blow mold device 21 has two sets of blow molds 20, 20 provided within the machine bed 2 so as to be opened and closed in a radial direction of the rotary disk 5, and opening and closing and mold clamping are carried out by a pair of hydraulic cylinders 26, 26 and pistons 27, 27. Reference numeral 28 designates an elevating device for the blow mold device 21 by hydraulic pressure disposed over the bed plate 18 and a bottom plate 29 of the machine bed.
The blow core elevating device 22 has blow cores 30, 30 mounted downwardly thereon which extends through the base plate, the rotary disk 5 and the neck molds 6, 6 and is inserted into the parison 17, the stretching and blow cores 30, 30 being provided with a stretching core 32 within a blow tube 31, as shown in FIG. 4, so that upon actuation of the air cylinder 33, the entire blow core moves down, and subsequently, upon actuation of the air cylinder 34, only the stretching core 32 further moves down to axially extend the parison 17 held by the neck molds 6, 6 in the center of the closed blow molds 20, 20 and is blown into the parison to fully expand the cavity.
A molded product releasing stage D, as shown in FIG. 5 is provided at a position opposed to the temperature control stage B provided between the injection molding stage A and the stretching and blow molding stage C. The base plate 1 of the temperature control stage B has a temperature control mechanism mounted thereon which inserts temperature control cores 35, 35 into a temperature control member 37 located on under-side of the rotary disk 5 extending through the base plate 1, the rotary disk 5 and the neck mold 6 by an air cylinder 36.
The temperature control member 37 is connected to an elevating device 38 mounted longitudinally on the side of the machine bed. This elevating device 38 is composed of an air or hydraulic cylinder 40 and a piston 41, and a plurality of temperature control members 37, 37 are mounted on seat plate 42 at an extreme end of a rod of the piston 41.
The base plate 1 of the molded product releasing stage D has a releasing mechanism 45 mounted thereon which inserts a guide core 43 and a member 44 for dividing and opening the neck mold in a radial direction of the rotary disk 5 extending through the base plate 1 and the rotary disk 5. The releasing mechanism 45 is actuated by an air or hydraulic cylinder 47, and a molded product 46 falls plumb down without being adhered to either side of the neck mold 6 opened by the guide core 43 extended through and inserted into the neck mold 6.
Next, the stretching and blow molding stage C operates as follows: First, as shown in FIG. 1, when the neck molds 6, 6 are at the stop positions and the parison 17 is being molded at the injection molding stage A, the blow molds 20, 20 move up together with the mold opening and closing mechanisms 19, 19 disposed on the bed plate 18 by the cylinder 28 until they register with the neck molds 6, 6. Next, the mold opening and closing mechanisms 19, 19 are actuated to close the molds and the stretching and blow cores 30, 30 move down as previously mentioned to stretch and blow mold the parison 17 into a hollow molded article 46.
Upon completion of said molding, the blow molds 20, 20 are opened and the hollow molded article 35 is held on the neck molds 6, 6. Then, the elevating device 28 is actuated, the blow mold device 21 is moved down together with the bed plate 18 into the machine bed 2 as shown in FIG. 4, and the stretching and blow cores 30, 30 move up onto the base plate. At the same time, the injection molds 14, 14 are opened and the bottomed parison 17 is released while being held on the neck molds 6, 6. Since such upward and downward operation is carried out even in the temperature control portion and molded article releasing portion, there is present no member to impair rotation of the rotary disk 3 in a transporting direction of the neck molds 6, 6, the parison 17 and the hollow molded article 45, and the rotary disk 5 causes the neck molds 6, 6 to be transported towards the subsequent step.
As described above, in the present invention, the blow mold device 21 is made movably up and down so that when the rotary disk 5 is rotated, the blow molds 20, 20 cause the blow mold device 21 to move down while being open to permit the parison 17 and hollow molded article 35 along with the neck molds 6, 6 to move towards and away from the stretching and blow molding stage without being placed in contact each other. In addition, the opening distance of the blow molds 20, 20 will suffice to be a degree such that they may not touch the outer wall of the hollow molded article 35, and therefore the distance may be materially shortened as compared with the aforementioned prior arts. Accordingly, the spacing of the central divided line of two rows of the neck mold die plates disposed on the rotary disk is represented by (Thickness of one side of blow mold 9×2)+(Movable plate 24×2)+(Radius of hollow molded article 22×2), which is approximately 260 mm in case of a hollow molded article having a diameter 80 mm. Where 10 molds in one row or hollow molded articles of said size are provided, the rotary disk may be fabricated to have a diameter of approx. 2600 mm.
If molds with 20 hollow molded articles of the same size arranged in one row should be disposed on the rotary disk in a manner similar to the aforementioned prior arts, the diameter of the rotary disk would be approximately 3300 mm, and the resultant members increase in size thus making it difficult to provide land transportation from makers to users and difficult to manufacture the molds. In this respect, the present invention is advantageous to manufacture them in size not considerably greater than those of prior art. | A molding machine disclosed herein comprises a rotary disk having a required number of neck molds attached to the under-surface thereof, said rotary disk being located under the base plate, rotary disk capable of being intermittently rotated to thereby successively transport the neck molds to an injection molding stage, a temperature control state and a molded article releasing stage for continuous operation from the injection molding of parisons to the releasing of hollow molded articles. The present invention is characterized in that blow molds and mold opening and closing mechanisms therefor disposed movably up and down in the stretching and blow molding stage are moved up at the stretching and blow molding whereas moved down at the transporting the parisons and hollow molded articles. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an alloy steel from which rolls of a cold rolling mill, in particular, work rolls are made. More specifically, the invention relates to a roll steel for rolls used in a cold rolling mill and this steel has extremely high wear resistance without any deterioration of resistance to thermal cracking, spalling resistance, and other mechanical characteristics.
2. Description of the Prior Art
As a prior steel from which rolls of a cold rolling mill, in particular, work rolls are made, the industry has adopted a kind of steel which contains 0.70 to 1.20 wt% of C, 0.15 to 1.00 wt% of Si, 0.15 to 1.00 wt% of Mn, 1.30 to 6.00 wt% of Cr, 0.20 to 0.50 wt% of Mo, and 0.40 wt% or less of V and has a Shore hardness (Hs) of 80 to 100. Recently, however, materials to be rolled become harder and the market trend is toward much thinner products This situation makes the rolling requirements severer, requiring the roll manufacturers to supply rolls with higher wear resistance.
To meet these requirements, the manufacturers tend to use high alloy materials to allow rolls of a cold rolling mill to have sufficiently high wear resistance in preference to other characteristics.
JIS SKD 11 steel, JIS SKH 57 steel, or improved roll steel derived therefrom are used to make rolls for Sendzimir or Cluster mills. If the roll diameter exceeds 300 mm, the manufacturing method thereof is under various restrictions. In addition, during rolling operation, the roll surface suffers many problems with its macroscopic or microscopic structure, including segregation associated with high alloying and coarse carbides dropped out of the surface. These problems are possible factors which may impair the surface of materials to be rolled.
SUMMARY OF THE INVENTION
The present invention provides, as a solution to those problems described above, a new and improved roll steel having high wear resistance equivalent to a cold die steel or high speed steel by minimizing an addition of alloying elements to the base made of some known kind of steel and adding a trace quantity of Ti to the base as substitutes therefor. The present steel offers all of the characteristics necessary for rolls used in a cold rolling mill.
The most important feature of the present invention is to add a trace quantity of Ti as a component to produce the present steel.
It is, therefore, an object of the present invention to provide a highly wear-resistant roll steel from which rolls of a cold rolling mill are made, comprising 0.70 to 1.50 wt% of C, 0.15 to 1.00 wt% of Si, 0.15 to 1.50 wt% of Mn, 2.50 to 10.00 wt% of Cr, 1.00 wt% or less of Mo, 1.00 wt% or less of V, 1.00 wt% or less of Ni, and 0.04 to 0.30 wt% of Ti with the balance being Fe and inevitable impurities.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing a relationship between Ti addition and abrasion loss and the numbers in parentheses are the sample numbers listed in Table 1 described later;
FIG. 2 is a graph showing relationships between Ti addition and mechanical properties and T.S, El and RA represent tensile strength (kgf/mm 2 ), elongation (%), and reduction of area (%), respectively;
FIG. 3 shows profiles for comparison of the surface roughness of the present and prior rolls before rolling with that of the rolls after rolling; and
FIG. 4(a) is a graph showing relationships between rolling distance and friction coefficient and FIG. 4(b) is a graph showing relationships between rolling distance and rolling speed. In those graphs, the solid line shows the present rolls and the dotted line shows the prior rolls.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now the components and their contents of the present roll steel are described below together with the reasons why the present inventors have adopted them.
(1) C: 0.70 to 1.50 wt%
C is an element which may affect most in giving to the present steel a hardness, one of the basic characteristics required for rolls used in a cold rolling mill. Less than 0.70 wt% of C provides an insufficient hardness for the material and more than 1.50 wt% of C deteriorates markedly the mechanical characteristics thereof. Thus, the inventors have adopted the C content, 0.70 to 1.50 wt%.
(2) Si: 0.15 to 1.00 wt%
Si usually acts as a deoxidizing element and is effective to improve hardenability and cracking resistance of the steel. Excess addition of the element, however, may impair the cleanliness of the steel due to deoxidation products and reduce the toughness. Thus, the inventors have adopted the Si content, 0.15 to 1 00 wt%.
(3) Mn: 0.15 to 1.50 wt%
Mn is a deoxidizing element like Si and has remarkable effects on improvement of hardenability. Excess addition of the element, however, may greatly drop the Ms point, increasing the quenching crack susceptibility. Thus, the inventors have adopted the Mn content, 0.15 to 1.50 wt%.
(4) Cr: 2.50 to 10.00 wt%
Cr has effects on improvement of not only tempering resistance but wear resistance by producing carbides of M 7 C 3 and M 3 C 2 types. The former is a fine carbide and the latter is coarse and greatly reduces the toughness. To prevent the latter from forming, it is necessary to select an appropriate ratio of Cr/C, for example, approximately 6. Thus, the inventors have adopted the upper limit of Cr content, 10.00 wt%, with that of the C content, 1.50 wt%.
(5) Mo: 1.00 wt% or less
Mo has remarkable effects on improvement of wear and tempering resistances, but more than 1 wt% of Mo may markedly deteriorate the mechanical properties and the heat treatment of the steel may be under some restrictions. In addition, Mo is expensive and may raise the production cost for rolls of a cold rolling mill when their diameters exceed 300 mm. Thus, the inventors have adopted the upper limit of Mo content, 1.00 wt%.
(6) V: 1.00 wt% or less
V, like Mo, has remarkable effects on improvement of wear resistance but more than 1 wt% of V may adversely affect the grindability of the roll. Its economic aspect has also caused the inventors to adopt the upper limit of V content, 1.00 wt%.
(7) Ni: 1.00 wt% or less
Ni is an important element to improve the hardenability. A proper amount of Ni must be added depending on the hardness penetration required for the roll, but more than 1.00 wt% of Ni may increase the retained austenite and cause fine dents on the roll surface. Thus, the inventors have adopted the upper limit of Ni content, 1.00 wt%.
(8) Ti: 0.04 to 0.30 wt%
Ti is the most important element for the present invention and is closely related to the characteristics required to achieve the object of the present invention. Therefore, this element and its content the inventors have adopted are described below in detail.
First, the significance of adding Ti to form the present steel is described.
The roll steels each having the components as shown in Table 1 were examined on various characteristics through several experiments. The experimental results are shown in FIGS. 1 through 4.
TABLE 1__________________________________________________________________________Chemical composition of samples (wt %)No. C Si Mn P S Ni Cr Mo V Ti__________________________________________________________________________1 0.84 0.35 0.41 0.013 0.005 0.12 3.02 0.25 0.07 --2 0.87 0.37 0.42 0.019 0.004 0.11 5.03 0.26 0.07 --3 0.84 0.36 0.40 0.017 0.008 0.13 4.98 0.23 0.06 0.034 0.86 0.35 0.40 0.015 0.007 0.10 5.05 0.25 0.08 0.045 0.86 0.34 0.39 0.012 0.006 0.10 4.95 0.25 0.05 0.066 0.85 0.36 0.44 0.015 0.004 0.12 4.96 0.24 0.06 0.087 0.85 0.35 0.42 0.017 0.005 0.13 4.98 0.23 0.06 0.138 0.84 0.34 0.45 0.022 0.008 0.11 5.03 0.22 0.06 0.199 0.85 0.37 0.42 0.019 0.006 0.10 5.10 0.21 0.05 0.2510 0.88 0.31 0.43 0.014 0.005 0.10 4.97 0.26 0.05 0.3011 0.85 0.35 0.44 0.013 0.004 0.14 4.99 0.25 0.07 0.4212 0.86 0.33 0.45 0.016 0.007 0.12 5.01 0.25 0.06 0.49__________________________________________________________________________
In the table, Nos. 1 and 2 samples are the prior arts, each having typical components as a material from which rolls for a cold rolling mill are made. Nos. 3 to 10 samples are the present roll steels and Nos. 11 and 12 samples are comparisons.
FIG. 1 is a graph showing a relationship between Ti addition and abrasion loss. Each sample was hardened and tempered to have an approximately HRC 63 hardness and then rubbed by an endless sanded belt type grinder under a pressure for a certain period. Abrasion losses (mg/cm 2 ) of those samples were measured and the wear resistance of each sample was compared with others. In the figure, the numbers in parentheses are the sample numbers.
From the figure, less than 0.04 wt% of Ti does not provide so large effects on the wear resistance but 0.04 wt% or more provides higher wear resistances than the prior arts. Around 0.15 wt% of Ti provides the wear resistance 3 times as high as that of the prior art which contains 5 wt% of Cr. This improvement of wear resistance is achieved by production of a very hard carbide TiC, which is dispersed finely and uniformly in the sample steel. However, more than 0.30 wt% of Ti causes segregation of TiC and reduction in grindability of the roll, preventing industrial applications of the steel. Thus, the upper limit of Ti content has been determined 0.30 wt%.
FIG. 2 is a graph showing relationships between Ti addition and mechanical properties. Each sample in Table 1 was hardened and tempered to have a HRC 32 hardness and its mechanical properties, that is, tensile strength (T.S, kgf/mm 2 ), elongation (El, %), and reduction of area (RA, %) were determined by tensile testing and compared with others.
As shown in FIG. 2, a Ti addition of 0.04 to to 0.30 wt% produces little variation in tensile strengh, elongation, and reduction of area.
The prior steels have been developed by adding a large quantity of Mo, V, W, and other alloying elements to provide higher wear resistance. This large addition of alloying elements greatly reduces the mechanical properties and the prior rolls for a cold rolling mill, which are required to have a high hardness, cannot be heat-treated enough if their barrel diameters exceed 300 mm.
The present steel, however, contains a trace quantity of Ti, which improves the wear resistance remarkably as shown in FIG. 1 without any adverse effect on the mechanical properties.
The present invention will be understood more readily by reference to the following examples in which several rolls made from the present steel are applied to a rolling mill in service. However, these examples are intended to illustrate the invention and are not to be construed to limit the scope of the invention.
EXAMPLES
A steel having the compositions similar to those of Nos. 5 and 6 samples in Table 1 was used to make work rolls for a cold tandem mill which rolls tin plates and the rolls were applied to the mill. The barrel diameter of each roll was 610 mm.
The rolls were used at the No. 6 final stand for rolling tin plates. The experimental rolling results were compared with those of the prior art containing 5 wt% of Cr and shown in Table 2 and FIGS. 3 and 4.
TABLE 2______________________________________Consumption per unit production ofpresent invention and prior art (5 wt % of Cr)Roll type Consumption per unit production______________________________________Present invention 0.06 mm/1000 tPrior art 0.35 mm/1000 t______________________________________ Note: The rolls were only used at the final stand of a tandem mill for ti plate rolling and the consumption per unit production was calculated on rolls which were replaced when they showed a certain level of wear due to normal operation.
Table 2 shows roll consumptions per unit production of the present invention containing Ti and the prior art comprising a 5 % Cr steel. For purpose of this specification, the consumption per unit production means a roll consumption caused by rolling 1000 t of products at the final stand. As shown in the table, the present invention exhibits a much lower roll consumptions, that is, approximately one sixth of what the prior art does.
Generally, rolls for a cold rolling mill must be ground to make the surface have a certain roughness before applied to rolling operation. Moreover, it is important to prevent the initial roughness from deteriorating during the rolling operation.
FIG. 3 shows profiles for comparison of the surface roughness of the present and prior rolls before rolling with that of the rolls after rolling.
The rolls made from the present steel did not show a large difference in surface roughness between before and after the rolling even if they rolled twice (in amount) what the prior rolls did.
The surface roughness of rolls is closely related to the friction coefficient. The friction coefficient is also a factor which affects stable rolling operation. When a friction coefficient between a roll and cold strip is 0.015 or less, the rolling operation usually becomes unstable, resulting in slip or wreck accidents. To avoid them, the rolls must be replaced when the friction coefficient drops to some level.
FIG. 4 shows relationships between rolling distance and friction coefficient [FIG. 4(a)] and those between rolling distance and rolling speed [FIG. 4(b)].
As may be seen from FIG. 4(a), the present rolls continued to have a friction coefficient of approximately 0.02 throughout the rolling, indicating that the rolls kept much stabler than the prior rolls and that they can make a great contribution to the rolling operation.
In addition, the present rolls exhibit a much smaller drop in initial friction coefficient (initial griding roughness) at a rolling distance of 0 to 100 km as compared with the prior rolls. Therefore it is possible to make initial grinding roughness of rolls after the roll replacement small and make friction coefficient small. (more than 0.015). Then it is possible to make rolling separate force low.
Thus, low initial rolling separate force permits a high rolling speed immediately after the roll replacement as shown in FIG. 4(b).
It should be noted that the practical experiments mentioned above were made with the rolls installed on the final No. 6 stand of a tandem mill and that the friction coefficients were calculated with the Bland and Ford's equation.
Those excellent results obtained from the present rolls installed on the practical mill are based on their high wear resistance, which may have large industrial influence.
As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims. | A steel from which rolls for a cold rolling mill are made and which gives to the rolls very excellent wear resistance in addition to thermal shock and spalling resistances and various mechanical characteristics is provided. Said steel comprises:
C : 0.70 to 1.50 wt %
Si: 0.15 to 1.00 wt %
Mn: 0.15 to 1.50 wt %
Cr: 2.50 to 10.00 wt %
Mo: 1.00 wt % or less
V : 1.00 wt % or less
Ni: 1.00 wt % or less
Ti: 0.04 to 0.30 wt %
with the balance being Fe and inevitable impurities. | 2 |
FIELD OF THE INVENTION
[0001] The present invention is directed generally to a fluid cleaning textile for use in lithographic and ink jet printing systems. More specifically, the present invention is directed to a non-woven textile which is usable as an image transfer surface cleaning device in lithographic printer machines and as an inkjet nozzle-cleaning device in inkjet printer cleaning systems. Even more specifically, the present invention is directed to a non-woven textile largely comprised of low denier splitable staple fibers for use in lithographic blanket and cylinder ink-cleaning devices and in inkjet nozzle ink-cleaning cassettes. The non-woven fabric is manufactured utilizing at least 80 percent, by weight, splitable fibers each of less than 100 mm in length and which are purposely structured to become less than one denier in size during processing into a finished non-woven. Such a non-woven has a mass per unit area in the range from 20 grams per square meter (gsm) to 500 gsm and a measured air permeability value from 2 cubic feet per minute at ½ inch of water pressure (CFM), to 500 CFM. The present non-woven fabric most preferably has a peak tensile strength to mass per unit area ratio of at least 2.90 Newtons per 5 centimeters per GSM.
BACKGROUND OF THE INVENTION
[0002] It is generally known in the art to use fabrics as cleaning media for printing machines. An inkjet printing machine cleaning fabric in disclosed in U.S. Pat. No. 6,957,881 to Nishina et al which describes the need to periodically maintain inkjet nozzle cleanliness and recites the use of a high density 0.1 denier fiber woven textile as a preferred media for an ink wiping device. Nishina does not disclose a specific fiber length nor make reference to a non-woven but does disclose the need for a cleaning fabric in an inkjet printing machine. A lithographic printer machine cleaning media is marketed as DuPont Sontara® PrintMaster and is advertised as providing a superior performance lithographic printer machine cleaning media due to its high absorbency, low linting, and high strength characteristics. Additionally, U.S. Pat. No. 5,974,976 to Gasparrini et al describes a reduced air content nonwoven fabric which is usable for cleaning various cylinders within a lithographic printing machine. Although Gasparrini does not claim any fiber detail comprising the non-woven, Sontara® is asserted as utilizing staple fibers which are equal to or more than 1 denier in size.
[0003] There is a continuing need to reduce printer machine down-time which, for the printer operator, equates to less waste, lower costs, less maintenance, and potentially higher profitability. A common configuration for a printer machine cleaning non-woven textile within a lithographic printer machine is in the form of a roll, which is installed into a housing cassette that is usable for periodically unwinding clean material, for delivering the clean non-woven material to the area requiring cleaning, and for rewinding consumed material within the cassette. Common configurations for printer machine cleaning non-woven materials within an inkjet printer encompass the aforementioned one, as well as rolls which do not unwind during use, continuous loop shapes, pads, or sheets, all of which are installed into a housing cassette which delivers the non-woven to the area requiring cleaning. The surface being cleaned in both lithographic and inkjet printer machines requires a non-woven to readily absorb fluid, to mechanically scrub and remove particulate from a surface, and also to retain the removed fluids and particulates, all without either depositing components of what comprises the non-woven or re-depositing any of the removed fluid and particulate.
[0004] It is common, in the prior art, to add woodpulp fibers to the composition of a non-woven to provided necessary absorbency. DuPont Sontara® PrintMaster acquires its high fluid absorbency through the use of a select amount of cellulose or woodpulp type fibers which are purposefully added to the non-woven construction. These natural fibers are well known to provide rapid and substantial absorbency similar to a “paper towel” used commonly for various applications. The limitation of this fiber type is its inherent nature to shed or to release portions of the woodpulp fibers upon contact with certain abrasive printer machine surfaces such as sharp nozzle plates, tacky rollers, or rough rollers, thus creating the need for an improved low-lint textile. Using synthetic man-made fibers and excluding the woodpulp content, as described in U.S. Pat. No. 7,745,358 to Benim et al, provides the ability to increase the shed resistance of a nonwoven by utilizing entirely synthetic fibers, such as polyester or poly(ethylene terephthalate).
[0005] It is also known to use continuous length filaments rather than staple fibers as one method to prevent fiber shed or fiber deposit. European patent 1,753,623 to Howey et al describes using a continuous filament synthetic construction which is thermally point-bonded to provide increased shed resistance. The two devices previously mentioned in European patent 1,753,623 to Howey et al, and U.S. Pat. No. 7,745,358 to Benim et al, increase the shed resistance of a non-woven but both discuss the use of thermal bonding to adhere the various components, when creating the final non-woven. Thermal bonding relies on a specific component of the non-woven to change phase from a solid to liquid and to then return to a solid. However, while this component is in the liquid phase, it tends to flow into adjacent components, thus acting as an adhesive within the non-woven structure. This reduces void space within the non-woven structure and also reduces fiber surface area, both of which negatively affect fluid absorbency and textile cleaning ability. If thermal point-bonding is not used in the construction of continuous length filament non-wovens, then these filaments are produced using the spunbond process which typically results in non-wovens having larger denier fibers. Such larger denier fibers will adversely affect mechanical cleaning ability or, if they are micro-denier sized, they can break and shed similarly to woodpulp containing non-wovens.
[0006] Freudenberg's Evolon® is an example of a micro-denier, continuous filament, cleaning non-woven and is detailed in U.S. Pat. No. 6,706,652 to Groten et al. BMP America first utilized Evolon® for lithographic and inkjet printer cleaning applications in 2004, recognizing that sub-denier or micro-denier splitable continuous filaments are preferred due to the amount of available surface area each fiber provides per surface area of finished textile. This high amount of available filament surface area provides a high amount of void space in which fluid can readily be absorbed. This is also supported by U.S. Pat. No. 7,745,358 Benim et al which also describes the addition of up to 10 percent of splitable staple micro-fibers to increase non-woven absorbency. When micro-denier splitable continuous filaments are highly entangled such as in Evolon®, the opportunity for a filament to break and shed exists but resistance to shed is much improved. Therefore, such micro-denier splitable continuous filaments have proven to be a viable option as a printer machine cleaning non-woven. However, they are challenging to manufacture and thus are costly. They also exhibit poor uniformity at lower basis weights.
[0007] The caliper thickness of such a non-woven, when used in a printer cleaning system, has a direct impact on the quantity of textile which can be contained within the delivery cassette. One way to decrease caliper thickness is to squeeze or calendar the non-woven to a lower caliper thickness value, as described in U.S. Pat. No. 5,974,976 to Gasparrini et al. However, calendaring often adds cost to a process, thus increasing final non-woven cost. It will thus be seen that a need exists for an improved non-woven which has the ability to mechanically scrub a surface, to present a uniform surface area, to absorb and retain waste, to resist shedding, to allow for quantitatively more non-woven within a given space, and to provide a cost advantage, all while meeting prior art non-woven strength specifications.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a non-woven textile suitable for use as a waste cleaning device for use in lithographic and inkjet printing machines.
[0009] Another object of the present invention is to provide a non-woven textile useable as a cleaning device for collecting and containing printer-ink.
[0010] Yet a further object of the present invention is to provide a printer-ink cleaning device that provides uniform and efficient removal of waste ink from an inked surface that is superior to prior art.
[0011] Typically, waste ink accumulates over time on a roller, cylinder, jacket, or print-blanket surface within a lithographic or offset printer. In accordance with the present invention, the non-woven fabric, when used as a lithographic printer ink cleaning device, can contact a surface which contains waste ink, will quickly remove such waste ink, and will resist fiber shed resulting from such contact with the surface containing the waste ink.
[0012] Inkjet printing typically relies on nozzles to spray atomized ink onto a printing media. Over time, these inkjet nozzles will collect excess ink and will also collect dust and other environmental contaminants, all of which need to be periodically cleaned and removed. In accordance with the present invention, the non-woven fabric, when used as an inkjet printer ink cleaning device, can contact a surface which contains waste ink and contaminants, such as a nozzle, will quickly remove such waste ink, and will resist fiber shed resulting from such contact with the surface containing the waste ink.
[0013] The present invention is directed to hydroentangled non-wovens which are formed from splitable staple fibers and which are suitable for use as strong, cost effective, and improved cleaning performance textiles that are utilized within offset and inkjet printing machines to clean various inked surfaces. The non-wovens have the ability to match or to surpass the cleaning ability of a continuous filament micro-denier non-woven, to surpass the tensile strength per unit mass ratio of commercially available printer machine cleaning non-wovens, to surpass the fiber uniformity of continuous filament non-wovens, to surpass the shed resistance of a continuous filament micro-denier non-woven and woodpulp or cellulose containing non-wovens, to match or surpass the absorbency of wood-pulp or cellulose containing non-wovens, and to be cost competitive in the commercial marketplace.
[0014] An important characteristic of the non-woven fabric in accordance with the present invention is its tensile strength to mass per unit area ratio. This value is determined by dividing the peak tensile strength of the non-woven by the weight per unit area of that non-woven. As an arbitrary numerical example, if a non-woven sample has a measured weight of 50 grams per square meter (gsm) and is measured to have a peak tensile strength of 100 Newtons per 5 centimeter (N/5 cm), that non-woven has a strength to weight ratio of 2 N/5 cm/gsm. Superior tensile strength to mass per unit area ratios indicate a higher entanglement of fibers and an overall improved non-woven construction, fiber structure, and uniformity.
[0015] Another important characteristic of the non-woven fabric of the present invention is the fiber size, quantified by denier and length, which comprises the non-woven. The fiber size is obtained by utilizing purposefully made splitable staple fibers of less than 100 mm in length and by mechanically processing the splitable fibers to obtain a highly tangled and uniform non-woven fabric largely consisting of fibers which have become smaller than one denier due to processing. Fibers which are smaller than one denier will be referred to as microdenier fibers and are synonymous with the term microfiber.
[0016] Splitable microdenier continuous filaments, as opposed to staple fibers, were introduced to ink cleaning applications by BMP in 2004 based on the recognition of the high amount of available surface area per unit volume of such filaments, which allowed for superior cleaning and fluid absorbency. This structure is also mechanically tough. However, an inherent limitation of non-wovens which contain continuous filaments is poor uniformity, when produced in relatively low basis weights and particularly in weights of less than 80 grams per square meter. The use of a split staple microfiber provides the non-woven of the subject invention with a uniform distribution of mass per unit area and a mechanically tough structure due to the staple fiber's ability to entangle in three dimensions within the textile versus a more typical two dimensional entanglement, which is common among non-wovens which contain continuous filaments. The high degree of staple microfiber entanglement and uniformity is also present when producing textiles at basis weights of less than 80 grams per square meter, which is the weight range where continuous microfiber textiles struggle.
[0017] Uniform distribution of mass within the non-woven is a direct result of the ability to process the staple fiber through a non-woven carding machine. The carding machine parameters and the staple fiber length are both specified to provide improved distribution, while longer fibers or other processes for creating a non-woven structure, such as the spunbond process, adversely affect mass distribution. After the splitable staple fibers are further processed and are split into smaller microdenier fibers, the mass distribution uniformity is only improved beyond the carding machine capability.
[0018] One way of measuring such uniformity is to test and to record air permeability at various locations throughout the finished textiles and to then compare the standard deviation of readings between the different textiles. The split staple microdenier textile, in accordance with the present invention, has a much lower standard deviation, which correlates to higher uniformity. The increased uniformity of microfibers, per unit area of the non-woven, provides a highly tangled structure which is shed resistant and mechanically superior, when compared to similar non-woven structures which are composed of larger denier or of continuous length fibers. The uniform structure also provides a strong capillary force which results in the non-woven having an affinity for ink in printer cleaning applications.
[0019] Capillary force in a non-woven is a function of the surface tension of fluid with respect to fiber type, of the contact angle of the fluid on the fiber and of the fiber surface area per unit volume of the non-woven. Capillary force in a non-woven is analogous to capillary head in a vertical capillary tube. This is based on the concept that the space between the fibers in the non-woven can be approximated as a vertical capillary tube. The equation for force in a vertical capillary tube is given as follows:
[0000] F= 2 πrσ LV cos θ LS
[0000] where,
F=Capillary Force r=Tube Radius σ LV =Surface Tension θ LS =Contact Angle
The fiber surface area, per unit volume of the non-woven, is a function of the non-woven's density and fiber size. The equation for fiber surface area, per unit volume of the non-woven, is given as follows:
[0000]
S
A
=
(
4
d
f
)
(
ρ
ρ
f
)
[0000] where,
SA=fiber surface area per unit volume d f =diameter of fiber ρ=density of non-woven needlefelt ρ f =density of fiber
A higher SA will create many individual capillary tubes within the non-woven thus creating a high capillary force, F in the non-woven.
[0028] The splitable staple fiber non-woven in accordance with the present invention overcomes the limitations of the prior materials. It is a substantial advance in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] While the novel features of the splitable staple fiber non-woven useable as an ink cleaning device in accordance with the present invention are set forth with particularity in the appended claims, a full and complete understanding of the invention may be made by referring to the detailed description of the preferred embodiments, as presented subsequently, and as illustrated in the accompanying drawings in which:
[0030] FIGS. 1A and 1B are plan views of the splitable staple fiber non-woven useable as an ink cleaning device in accordance with the present invention,
[0031] FIG. 1C is a plan view of a similar basis weight, prior art continuous filament microdenier non-woven;
[0032] FIG. 2A is a magnified (cross-sectional) views showing an appearance of the non-woven useable as an ink cleaning device in accordance with the present invention, compared to a similar basis weight continuous filament microdenier non-woven, as shown in FIG. 2B ;
[0033] FIG. 3A is a schematic view showing the appearance of staple splitable fibers largely comprising the nonwoven usable as an ink cleaning device in accordance with the present invention, as compared to a schematic view showing the appearance of continuous filaments in FIG. 3B ;
[0034] FIG. 4 is a cross-sectional view showing the appearance of a staple splitable fiber largely comprising the nonwoven usable as an ink cleaning device in accordance with the present invention;
[0035] FIG. 5 is a photograph showing a roll of the splitable staple fiber non-woven useable as an ink cleaning device in accordance with the present invention;
[0036] FIG. 6 is a chart showing the air permeability of prior art Evolon® 60 gsm nominal weight material;
[0037] FIG. 7 is a chart showing the air permeability of the splitable staple fiber non-woven in accordance with the present invention configured as a 60 gsm nominal weight material;
[0038] FIG. 8 is a chart showing the air permeability of the splitable staple fiber non-woven in accordance with the present invention configured as a 40 gsm nominal weight material; and
[0039] FIG. 9 is a representation of one manufacturing process of the present non-woven invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0040] The term non-woven, as used herein, refers to a textile without a specified pattern or quantity of fibers or filaments oriented in specific axes of the textile surface. The term can also be defined as the opposite structure of a knitted or woven textile structure.
[0041] The term hydroentangled, as used herein, describes a non-woven manufacturing method in which the fibers are locked into place and entangled using high pressure fluid jets.
[0042] The term splitable, as used herein, is used to describe a fiber that reduces its size when processed through a variety of steps. The fiber is typically composed of more than one polymeric substance contained within the same filament and is formed in a way such that the multiple polymers are segmented and separable by chemical or physical means. Common splitable fiber cross section structures include, but are not limited to, segmented pie, “islands in the sea,” segmented tri-lobes, segmented cross, segmented ribbons, striped round fibers, hollow fiber core, and hollow segmented pie. Common polymers used include, but are not limited to, polyethylene terephthalate (polyester or PET), co-polyester, Polyamide (Nylon 6 or Nylon 6,6), polypropylene, polyethylene, and polyvinyl alcohol.
[0043] The term staple is used to describe a natural fiber or a finite length synthetic fiber which has been cut from a filament. Typical cut length of the staple fiber is between 0.2 inches and 6 inches.
[0044] FIGS. 1A , 1 B, and 1 C are photos of three different non-wovens. FIG. 1A is a photo of a 45 gsm nonwoven composed of splitable staple fibers, in accordance with the present invention, and is shown to demonstrate the macroscopic uniformity of a sub-80 gsm textile. Small areas of textile may still exhibit zero fiber content. However, these areas are typically not significant enough to affect cleaning performance in most applications wherein a surface to be cleaned is contacted multiple times during a cleaning cycle. FIG. 1B is a photo of a 60 gsm non-woven composed of splitable staple fibers, in accordance with the present invention, and shows the most uniform fiber distribution. This photo demonstrates the superior non-woven uniformity that is attained from this invention. FIG. 1C is a photo of a 60 gsm prior art micro-denier splitable continuous filament non-woven which has similar macroscopic uniformity compared to the 45 gsm nonwoven composed of splitable staple fibers in accordance with the present invention.
[0045] FIGS. 2A and 2B are two scanning electron microscope photos of a magnified cross-sectional view comparing a splitable staple fiber non-woven, in accordance with the present invention in FIG. 2A , to a prior art continuous filament microdenier non-woven shown in FIG. 2B . The photo identified as the splitable staple fiber non-woven in FIG. 2A shows a higher degree of fibers entangled through the cross section of the textile or “Z-direction” of the textile (considering the X-Y plane to be the face of the textile).
[0046] FIGS. 3A and 3B provide a visual representation of the primary difference between staple fibers, as shown in FIG. 3A , and continuous filaments, as shown in FIG. 3B . These visual representations also help provide a visualization of the higher degree of entanglement which is potentially available from staple fibers versus continuous filaments.
[0047] FIG. 4 is a cross-sectional view showing the appearance of a single staple splitable fiber which largely comprises the splitable staple fiber nonwoven usable as an ink cleaning device in accordance with the present invention. The cross-section of a suitable single staple splitable fiber is not limited to this structure or polymer set, as described previously. Suitable splitable fiber cross section structures that are usable in the present invention include, but are not limited to, segmented pie, “islands in the sea,” segmented tri-lobes, segmented cross, segmented ribbons, striped round fibers, hollow fiber core, and hollow segmented pie. Common polymers which may be used include, but are not limited to, polyethylene terephthalate (polyester or PET), co-polyester, Polyamide (Nylon 6 or Nylon 6,6), polypropylene, polyethylene, and polyvinyl alcohol.
[0048] FIG. 5 is a photograph showing the appearance of the splitable staple fiber non-woven useable as an ink cleaning device, in accordance with the present invention, in roll form. This roll form depiction is provided as a visual example and is not intended to limit the present invention to any specific delivery form. Other potential forms of delivery include, but are not limited to, sheets, pads, belts, loops, cassettes, and formed shapes.
[0049] FIG. 6 is a chart showing twenty five air permeability readings of prior art Evolon® 60 gsm nominal weight material in units of CFM/ft 2 at ½ inch of water pressure. This chart can be used as a comparative tool to compare the uniformity of the prior art textile with the present invention. These values provide an average reading of 151 CFM/ft 2 and a standard deviation of 50.66.
[0050] FIG. 7 is a chart showing twenty five air permeability readings of the splitable staple fiber non-woven 60 gsm nominal weight material, in accordance with the present invention, in units of CFM/ft 2 at ½ inch of water pressure. The chart can be used as a comparative tool to characterize the uniformity of the textile. These values provide an average reading of 58.208 CFM/ft 2 and a standard deviation of 6.36 which should be noted as being a significant improvement compared to FIG. 6 .
[0051] FIG. 8 is a chart showing twenty five air permeability readings of the present splitable staple fiber non-woven, provided as a 40 gsm nominal weight material, in accordance with the present invention, in units of CFM/ft 2 at ½ inch of water pressure. This chart can also be used as a comparative tool to characterize the uniformity of the textile of the present invention. These values provide an average reading of 156.72 CFM/ft 2 and a standard deviation of 19.07 which is a substantial improvement compared to FIG. 6 .
[0052] FIG. 9 is a schematic depiction of one manufacturing process for making a splitable staple fiber non-woven in accordance with the present invention. A bale of staple splitable fibers 1 from a commercial source is mechanically opened by a conveyor belt 2 and fibers are sent to a carding machine 3 which provides a uniform distribution of fibers in the form of a web. The fibrous web is transported to a lapping machine 4 which layers the web in accordance with a desired target mass per unit area. The lapper 4 can provide layering in the same direction (or machine direction) of the manufacturing process. The lapper 4 can also provide layering in the perpendicular direction (or cross direction) of the manufacturing process. Multiple lappers can also be used before a conveyor belt 5 transports the layered web to the next process, which is a mechanical fiber splitting process. Splitting can be done in many physical or chemical ways, one way being hydro-entanglement, which is shown, as the layered web 6 is transported to perforated cylinders 7 which receive water that is directed out of opposing high pressure nozzles 8 . This drawing shows three sets of perforated cylinders 7 each having a set of nozzle jets 8 . The number of sets of perforated cylinders 7 can vary as long as the equipment can provide enough force to achieve the strength and uniformity properties desired for the splitable staple fiber non-woven in accordance with the present invention. A vacuum system 9 is then used to remove excess water from the now hydro-entangled non-woven before it is optionally squeezed with rollers 10 that further remove any residual excess water. The splitable staple fiber non-woven in accordance with the present invention is then sent through a drying system 11 before being optionally calendared at a calendaring station 12 to a lower thickness. Alternatively, the layered web can be mechanically split using needle punch technology or can be chemically split by dissolving a carrier membrane which surrounds the staple microfiber. Other splitting and entanglement procedures are also within the scope of the present invention.
EXAMPLES
Example #1
[0053] In this first example, 51 mm long EASTLON 2.0 denier mechanically splitable staple microfibers, composed of polyester and nylon, are processed through a bale opening machine ( 2 in FIG. 9 ) and a carding machine 3 to uniformly spread the fibers across the width of a moving belt 4 . The belt 4 transports the web of fibers or multiple layers of webs 5 , targeting a total final weight of 60 grams per square meter, to a series of high pressure water jets 8 and perforated cylinders 7 . Water jet orifices of the water jets 8 are spaced between 0.5 mm and 1.0 mm apart and with diameters ranging from 100 to 160 microns. Pressures of approximately 200 bar are used to split and to three-dimensionally entangle the splitable staple microfibers at multiple hydroentangling stations along the production path. The resultant split and entangled textile is then vacuum dried, using vacuum system 9 , squeezed using rollers 10 and heated in drying system 11 to remove all water content.
[0054] The result is a splitable staple microfiber 63 gram per square meter (gsm) textile (ASTM D-461 Section 11) with a thickness of 0.39 millimeters (ISO 9073-2) and an average peak tensile strength, in the machine direction, of 269 Newtons per 5 centimeters (N/5 cm) (ASTM D-5035-11). The ratio of this peak strength to weight is 4.27 N/5 cm per gsm. In comparison, Freudenberg's prior art Evoion®, at a weight of 60 gsm, has a measured average peak tensile strength, in the machine direction, of 165 N/5 cm and a strength to weight ratio of 2.75 N/5 cm per gsm. Air permeability testing is one way to compare material uniformity. As discussed previously, FIG. 6 shows twenty five air permeability readings (CFM/ft 2 at ½″ of H 2 O) of Freudenberg's prior art Evolon® at a weight of 60 gsm. These measurements were recorded using a Textest model FX3300 from TexTest AG, Zurich, Switzerland. The standard deviation of these readings is 50.66. This can be compared to 6.36, which is the standard deviation of twenty five readings of the 60 gsm target staple split textile in accordance with the present invention. The dramatically lower standard deviation of the present invention directly correlates to improved fiber uniformity which contributes to the significant strength to weight ratio of 4.27 N/5 cm per gsm of the subject invention.
[0055] The splitable staple fiber three dimensional entanglement of the present invention provides much better resistance to shed than does Freudenberg's prior art Evolon® which is more two dimensionally entangled. Abrasion resistance of the present invention textile was compared to that of Evolon® using a model 5130 Taber Abraser from Teledyne Taber, North Tonawanda, N.Y. Weight loss per unit area abraded was recorded in milligrams per square centimeter (mg/CM 2 ) and thickness loss was recorded in millimeters and was converted to percent thickness loss. Samples were tested for 100 cycles using an H-18 abrasion wheel with 1500 grams of total weight on each arm. The target 60 gsm textile of the present invention lost 113 mg/cm 2 and 16.0% of its original thickness while Evolon® 60 gsm lost 321 mg/cm 2 which is a factor of 2.8 times the 60 gsm textile amount, of the present invention and lost 22.4% of the original thickness which is a factor of 1.4 times the 60 gsm textile amount of the present invention. Thus, the present invention, of a splitable staple fiber non-woven has an improved tensile strength to mass per unit area ratio, improved uniformity, and improved resistance to shed while maintaining the prior art non-woven ability to mechanically scrub a surface and to absorb and retain waste.
Example #2
[0056] In this example, 51 mm long EASTLON 2.0 denier mechanically splitable staple microfibers, composed of polyester and nylon, are processed through a bale opening machine ( 2 in FIG. 9 ) and a carding machine 3 to uniformly spread the fibers across the width of a moving belt 4 . The belt 4 transports the web of fibers or multiple layers of webs 5 , targeting a total final weight of 40 grams per square meter, to a series of high pressure water jets 8 and perforated cylinders 7 . Water jet orifices of the water jets 8 are spaced between 0.5 mm and 1.0 mm apart with diameters ranging from 100 to 160 microns. Pressures of approximately 200 bar are used to split and to three-dimensionally entangle the splitable staple microfibers at multiple hydroentangling stations along the production path. The resultant split and entangled textile is then vacuum dried, using vacuum system 9 , squeezed using rollers 10 , and heated in drying system 11 to remove all water content.
[0057] The result is a splitable staple microfiber, 38 gram per square meter (gsm), textile (ASTM D-461 Section 11) with a thickness of 0.27 millimeters (ISO 9073-2) and an average peak tensile strength, in the machine direction, of 154 Newtons per 5 centimeters (N/5 cm) (ASTM D-5035-11). The ratio of this peak strength to weight is 4.05 N/5 cm per gsm. Recall that Freudenberg's prior art Evoion®, at a weight of 60 gsm, has a measured average peak tensile strength in the machine direction of 165 N/5 cm and a strength to weight ratio of 2.75 N/5 cm per gsm. As discussed, FIG. 8 shows twenty five air permeability readings (CFM/ft 2 at ½″ of H2O) of the 40 gsm target weight textile in accordance with the present invention. These measurements were recorded using a Textest model FX3300 from TexTest AG, Zurich, Switzerland. The standard deviation of these readings is 19.07 compared to the previously mentioned 50.66 value of Freudenberg's Evolon® 60 gsm, thus supporting the fact that splitable staple nonwovens can be made more uniform at lower basis weights compared to continuous filament nonwovens. Thus, the present invention provides a splitable staple fiber non-woven, which has an improved tensile strength to mass per unit area ratio and improved uniformity, while maintaining the prior art non-woven ability to mechanically scrub a surface, and to absorb and retain waste, to allow for quantitatively more non-woven within a given space, and to provide a cost advantage by reducing the amount of textile weight per unit area.
Example #3
[0058] In this example, 51 mm long EASTLON 2.0 denier mechanically splitable staple microfibers, composed of polyester and nylon, are processed through a bale opening machine 2 and a carding machine 3 to uniformly spread the fibers across the width of a moving belt 4 . The belt 4 transports the web of fibers or multiple layers of webs 5 , targeting a total final weight of 170 grams per square meter, to a series of high pressure water jets 8 and perforated cylinders 7 . Water jet orifices of the water jets 8 are spaced between 0.5 mm and 1.0 mm apart with diameters ranging from 100 to 160 microns. Pressures of approximately 200 bar are used to split and to three-dimensionally entangle the splitable staple microfibers at multiple hydroentangling stations along the production path. The resultant split and entangled textile is then vacuum dried, using vacuum system 9 , squeezed using rollers 10 , and heated in drying system 11 to remove all water content.
[0059] The result is a splitable staple microfiber, 162 gram per square meter (gsm), textile (ASTM D-461 Section 11) with a thickness of 0.76 millimeters (ISO 9073-2) and an average peak tensile strength, in the machine direction, of 595 Newtons per 5 centimeters (N/5 cm) (ASTM D-5035-11). The ratio of this peak strength to weight is 3.67 N/5 cm per gsm. Freudenberg's prior art Evolon® at a weight of 160 gsm, has a measured average peak tensile strength, in the machine direction, of 417 N/5 cm and a strength to weight ratio of 2.61 N/5 cm per gsm, once again demonstrating that the subject invention provides a splitable staple fiber nonwoven matching or surpassing the strength of a continuous filament nonwoven. Thus, the present invention provides a splitable staple fiber non-woven which has an improved tensile strength to mass per unit area ratio while maintaining the ability of the prior art non-woven to mechanically scrub a surface and to absorb and retain waste.
[0060] While preferred embodiments of a Splitable staple fiber non-woven useable as an ink cleaning device, in accordance with the present invention, have been set forth fully and completely hereinabove, it will be apparent to those persons skilled in the art that various changes and modifications may be made without departing from the spirit and scope thereof which is accordingly limited only by the following claims. | A non-woven textile constructed using splitable staple fibers is usable in lithographic and inkjet printer machine cleaning applications. The use of the splitable staple fiber non-woven in a lithographic printing machine provides improved removal and containment of waste inks, fluids, and paper dust within the printer machine. The use of the splitable staple fiber non-woven in an inkjet printing machine also provides removal of ambient particulate such as human hair or other particulate foreign to the printer machine contained within the printer machine. The cleaning ability of the non-woven textile is a function of several properties including the large amount of available fiber surface area per area of non-woven, the surface uniformity, the fibers' microscopic sharp edges, the capillary force, and the mechanical toughness provided by the highly entangled split staple fine denier fibers which make up the splitable staple fiber non-woven. | 3 |
BACKGROUND OF THE INVENTION
[0001] The packaging of the femoral stem component used in the orthopedic hip arthroplasty procedure has traditionally involved the use of inserts to stabilize the stem component within the package and these inserts have been tailored to the size of a particular stem component. Stem components are currently available in a substantial number of sizes with some manufacturers offering as many as ten sizes in order to better meet the needs of individual patients.
[0002] The traditional packaging of sterile medical devices such as implants including stem components has involved a system of an inner tray within an outer tray. Each tray is typically an open mouthed cavity with a peripheral rim to which a film is adhesively adhered to create a sealed package. The outer tray simply contains the inner tray which in turn contains the medical device, commonly stabilized within the tray with closed cell foam pieces. The pieces of foam are commonly selected to have configurations adapted to the particular device being packaged. Thus in the case of stem components different pieces of foam are required in progressing across the size range of such components. The two tray system provides some assurance that if the integrity of the outer tray is breached in shipping and handling, the steriiity of the packaged medical device is preserved by the inner tray.
[0003] This two tray system has some disadvantages. The foam used for stabilization within the inner tray is friable and, particularly with orthopedic implants with roughened surfaces to enhance bonding to living tissue, typically bone, it has been observed to abrade, creating a particulate contaminate. In addition, because the peripheral rim of the inner tray typically carries residual adhesive after the removal of the lid stock, it may not be placed on the surgical tray adjacent to the surgeon implanting the device. Consequently, the medical device must be fully removed from its protective packaging well before its use and is thus exposed to damage and being splashed with bodily fluids and tissue while awaiting implantation.
[0004] Thus there are benefits to be gained from a packaging approach in which a single package can be used across the size range of at least a single line of femoral stem components of a given design or from a single manufacturer. There are further benefits to be obtained from a complete package which can be removed from an inner tray and placed on a surgical tray thus providing protection for the packaged component until it is used and providing a convenient manner of presenting the component to the surgical team.
SUMMARY OF THE INVENTION
[0005] The present invention involves a package which is adapted to securely hold medical articles such as medical instruments or implants e.g. orthopedic implants such as any of a series of femoral stem components of artificial hip joints which have a dimension which does not vary greatly over a significant size range. This package is configured to provide a clearance which captures and closely approximates a minimally varying dimension of a medical article.
[0006] In the present invention a rigid, synthetic e.g. thermoplastic polymer package is provided having (A) a rigid base and (B) a cover having at least two compartments connected by a connecting hinge. The base and cover may also be connected by a peripheral hinge. The first compartment has a first interior surface and opposing first exterior surface where the first interior surface has one or more cavities whereby this first interior surface is adapted for movement restraining contact with a first portion of a medical article which has a fixed or minimally varying dimension. The second compartment has a second interior surface and opposing second exterior surface where the second interior surface has one or more cavities whereby this second interior surface is adapted for contact, preferably movement restraining contact, with a second portion of a medical article. The connecting hinge connects the first and second compartments to each other and provides for manual movement of the first compartment relative to the position of the second compartment to rotate the first interior surface away from the second interior surface and the opposite rotational movement is restricted or prevented e.g. the first interior surface cannot be rotated to cover the second interior surface.
[0007] One convenient way to provide the aforementioned clearance which captures and closely approximates a minimally varying dimension in a package for an orthopedic implant such as a hip implant is to provide a fairly flat rectangular package with three distinct but interconnected cavities, each of which accommodates one of the three distinct elements of a femoral stem component. In this regard, the typical stem component is comprised of a lower stem which is a long generally cylindrical portion adapted to be inserted into a femur, an angled shaft which is a short cylindrical portion adapted to be inserted into the femoral head or ball and a body which is a transition portion, also adapted to be inserted into the femur, which connects the short and long cylindrical portions. One edge of this body is typically just an extension of one edge of the lower stem and the other edge proceeds outward at an acute angle from the main axis of the lower stem. The angled shaft then extends outward from the end of the body distal from the lower stem at an acute angle to the main axis of the lower stem which is typically greater than the acute angle between the one edge of body and said axis. These three portions typically have about the same thickness such that they all extend about the same distance in a z direction where x and y directions extend along the length and width of the femoral stem component. In a preferred embodiment the largest member of the series femoral stem components for which the package is adapted just fits within the package with smaller members fitting in with some overall clearance.
[0008] One convenient approach is a package having a first compartment having first and second cavities connected by an integrally formed hinge to a second compartment having a cavity. In this approach the capturing clearance is provided by the cooperation of the second compartment's cavity adapted to contain the lower stem and the first compartment's cavity adapted to contain the body. In this approach, a communication port between these two cavities is sized to prevent the entrance of the body from the first compartment into the second compartment's cavity for the lower stem; and in the first compartment a wall of the first cavity adapted to contain the body distal from this port limits the motion of the body toward the second cavity adapted to contain the angled shaft. For this approach the cavities for the lower stem in the second compartment and the angled shaft in the first compartment may readily accommodate the full size range of the series with a significantly greater clearance. In a preferred embodiment, this distal wall of the body cavity is at an obtuse angle to the main axis of the lower stem cavity of the package. In a particularly preferred embodiment the body cavity has a wall which is a continuation of a wall of the lower stem cavity and the obtuse wall begins at the end of this continuation wall distal from the port between the lower stem cavity and the body cavity. In a particularly preferred embodiment the package is provided with two sets of cavities to accommodate the angled shaft and lower stem parts of the femoral stem component with both sets of cavities communicating with a common cavity for accommodating the body part. In an especially preferred version of this approach this common cavity for accommodating the body has two walk parallel to the main axis of the lower stem cavities, which are themselves parallel to each other, with each wall terminating at its end distal to the ports communicating with the lower stem cavities in an obtuse wall which in turn extends to one of the ports communicating with one of the cavities for accommodating the angled shaft.
[0009] One convenient approach to creating a package for a series of orthopedic implants such as femoral stem components is to create two flat generally rectangular tray components which are mirror images of each other, with each carrying one half of the three portions to adapted accommodate the lower stem, the body and the angled shaft, respectively, of the femoral stem component. These tray components are provided with means which reversibly lock them together so as to create the three communicating cavities which will accommodate the series of femoral stem components. In a preferred embodiment, each tray component is provided with a hinge located at approximately the juncture between the cavity for the lower stem and the cavity for the body which extends across the width of the tray component to define an upper tray section and a lower tray section. The two mating lower tray sections are provided with locking means which function to hold them together and the two mating upper tray sections are provided with locking means which function to reversibly hold them together. The two hinges and the reversible upper tray section locking means function to allow the two upper tray sections to be rotated away from each other. In an especially preferred embodiment the two tray components each carry two cavities for the lower stem and two cavities for the angled shaft and the two oblique walls discussed above.
[0010] In another approach, mating trays need not be utilized, but instead a generally flat rigid base is employed with a cover similar to the tray above but having deeper cavities in its first and second compartments. This base and cover may be either separate components or they themselves may be connected by a hinge at one of the peripheral edges of the cover.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a plan view of one of the two tray components 10 which may be a cover or base showing its longer hemi-tubular cavities 12 , the ports 13 leading from the cavities 12 to its transition cavity 14 , the oblique walls 16 of its transition cavity 14 , the ports 19 leading from cavity 14 to its shorter hemi-tubular cavities 18 , its hinge 20 , its reversible upper tray section locking means 30 and its reversible lower tray section locking means 32 .
[0012] FIG. 2 is a perspective view of the two tray components 10 facing each other such that they can be assembled by forcing them together to form a package for a femoral stem component. In addition to all the elements illustrated in FIG. 1 , also shown are the upper tray sections 40 and the lower tray sections 50 .
[0013] FIG. 3 is a perspective view of the two tray components 10 assembled together showing how the upper tray sections can rotate away from each other via the hinges 40 while the lower tray sections 50 remain affixed to each other.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention involves the design of packaging for medical articles such as medical instruments such cutting implements or implants such as orthopedic implants e.g. hip stems, shoulder stems, fixation devices which may be a length of e.g. stainless steel which is used to stabilize fractured bone, or other medical articles which may have abrasive surfaces or surfaces which have coatings or other materials for which contamination or surface removal by abrasion is a concern. In particular the invention may be used for a series of components e.g. shoulder or femoral stem components of various sizes e.g. for artificial joints such as for shoulders or hips, which components have a dimension which does not greatly vary over the size range of the series. The allowed variation in this dimension is such that the package can be designed to just accommodate this dimension for the largest member of the series and yet still accommodate the same dimension of the smallest member of this series without allowing undue motion of this smallest member. The package of the present invention can allow some range of motion to the smallest member of the series so long as this packaged component can still pass the shipping tests to which the manufacturers of medical articles, such as implants, routinely subject such products. This depends on the configuration and weight of the particular component being packaged and tested. In a preferred embodiment the packaging for a given series of stem components will provide a range of clearances for this dimension which ranges from essentially zero to 0.375 inches. The invention also involves the concept of designing such a common package with a clearance which captures this minimally varying dimension but also accommodates a range of sizes in the other dimensions of the medical articles e.g. stem components such as femoral stem components.
[0015] It is advantageous to construct the packaging such that the surfaces which contact the surfaces of the stem component have a high abrasion resistance. In this regard, medical articles such as orthopedic implants like stem components are typically constructed with a body portion which has a fairly rough surface to promote adhesion to the bones into which they are implanted. One type of surface with advantageous abrasion resistance is based upon thermoplastic aromatic polyether polyurethane. Deerfield Urethanes, a subsidiary of Bayer, markets suitable thermoplastic aromatic polyether polyurethane films under the trademark Dureflex® with grade PT9400 being particularly suitable. It is also advantageous to use this polyurethane surface to protect to the polished treated surfaces typical of orthopedic implants e.g. femoral stem components such as portions of the angled shaft.
[0016] It is also advantageous to construct the packaging out of materials which can be readily thermoformed into packages of suitable rigidity to support the largest component of the series for which the packaging is designed. The typical packaging material for medical implants including femoral stem components has been films of polyethylene terephthalate glycol (PETG) because they have adequate rigidity and mechanical strength and good thermal formability. However, it is desirable to have greater abrasion resistance than this material offers. It is convenient to laminate these films to films of thermoplastic aromatic polyether polyurethane and configure the packaging such that it is the polyurethane surface which faces the surfaces of the medical article e.g. stem component. The laminate is conveniently formed by melt laminating the polyurethane to the PETG. A preferred PETG for this lamination is Eastman's Eastar 6763 PETG resin. The thicknesses for both films should be compatible with both thermoforming the package configuration and providing adequate mechanical strength. A convenient range for the polyurethane is between about 0.01 and 0.025 inches while for the PETG it is between about 0.015 and 0.04 inches.
[0017] The packages with which the present invention is concerned can be conveniently designed using computer-aided design (CAD). One approach is to create three dimensional depictions of all the components in a given series such as the size range offered by a given manufacturer e.g. for stem components and then overlay them to determine the location and size of the minimally varying dimension. Commonly, for orthopedic implants such as stem components this is the length of the body portion measured along its outside edge which is a continuation of an outside edge of the lower stem component. Then a package can be designed which provides a clearance which closely approximates minimally varying this dimension and also accommodates the largest size component in the series e.g. the largest femoral component.
[0018] One approach to the packaging of a series of femoral stem components is illustrated in FIG. 1-3 . In this approach a base and a cover which may be two mirror image trays 10 are provided and are joined to each other in a face to face manner as illustrated in FIG. 2 . Each tray 10 carries a cavity 12 to accommodate the lower stem and first and second cavities 14 and 18 to accommodate the, body and angled shaft portions respectively of a stem component. The cavities 12 and 18 are hemi-tubular such that when two trays are joined in a face to face manner they provide tubular cavities to accommodate the somewhat cylindrical elements e.g. of the femoral stem component. These cavities 12 and 18 communicate with the cavity 14 which is designed to accommodate the body portion of the stem component via ports 13 and 19 , respectively. This cavity 14 is provided with two oblique walls 16 which are at an oblique angle to the main axis of the tray 10 or the cavities 12 . Either of the ports 13 and the oblique wall 16 directly opposite this port 13 in the direction of the main axis of the tray component 10 cooperate to capture the minimally varying dimension of the body of the stem component. The port 13 is designed such that the portion of the body adjacent to the lower stem of the series e.g. of femoral stem components for which the package is designed is unable to enter this port 13 . The distance from this port 13 to this oblique wall 16 approximates the length of the edge of the body portion which is a continuation of an outer edge of lower stem portion of e.g. the largest femoral stem component of the series for which the package is designed. Typically stem components such as femoral stem components carry an edge which proceeds at an oblique angle from the edge of the body portion which is a continuation of an outer edge of lower stem portion to the edge from which the angled shaft projects and it is this edge that the oblique wall 16 approximates. The trays 10 also each carry a hinge 20 which allows the package to be partially opened after assembly and two reversible closure means 30 and 32 to facilitate the assembly of the two trays 10 in a face to face manner.
[0019] The illustrated trays 10 are shown as each being symmetric about its main axis because this facilitates their production from a single mold. Any two tray components can then be placed face to face with their cavities facing inward to create an assembled package. However, non-symmetrical tray components could readily be designed to accommodate two different series of femoral stem components. In this case, separate molds would be required for the top and bottom tray components, but the number of sizes that the package could accommodate would be increased. Also, the base and cover or top and bottom trays may be connected by a peripheral hinge alone a top, bottom or side edge.
[0020] The package is provided with the ability to be partially opened to allow access to the packaged medical article such as a scalpel, catheter, drug coated implant, or an orthopedic implant e.g. a stem component while still providing some protection and support to this article. The hinges 20 divide each tray component 10 into an upper section or first compartment 40 having an interior surface 41 and exterior surface 42 and a lower section or second compartment 50 having an interior surface 51 and exterior surface 52 as illustrated in FIG. 2-3 . The hinges 20 also allow the two upper sections 40 to be rotated away from each other as illustrated in FIG. 3 . Thus the connecting hinges 20 (which may be integrally formed with the first and second compartments 40 , 50 ) provide for manual movement of the first compartment 40 relative to the second compartment 50 to rotate a first interior surface 41 of a cover or upper tray from a second interior surface of a base or lower tray. Also, the first compartment of the tray cannot be rotated about an axis of the hinge 20 to a position where the first interior surface 41 of the first compartment covers the second interior surface 51 of the second compartment because of stops formed by hinge walls 21 . The provision of separate closure means 30 for the upper tray section 40 and closure means 32 for the lower tray section 50 facilitates the partial opening.
[0021] This ability to partially open the package is viewed as a significant benefit to surgical teams e.g. a surgical team implanting an orthopedic article such as a femoral stem component. It allows them clean easy access to a medical article such as a stem component without having it exposed before it needs to be withdrawn from the protective packaging for use such as implantation. It also significantly reduces the risk of dropping the article in the course of removing it from its packaging. To extract a medical article e.g. the stem component from the partially opened package one must have a firm grip on it, while if the two tray components were not hinged for partial opening, but simply stripped from each other there is a chance the stem component would just fall from the packaging.
Working Example
[0022] A prototype set of tray components 10 were thermoformed from a melt lamination of 0.01 inch thick Duraflex®PT 9400 aromatic polyether polyurethane onto 0.02 inch thick Eastar® 6763 PETG in such a way that the internal surface facing the contents to be packaged was of the PT9400. Each tray 10 was essentially a rectangle about 10.156″ long by 3.875″ wide. It had a 0.125″ hinge groove which spanned its width located about 6.06″ from the short end distal from the angled shaft cavities. Each of the lower stem cavities was about 0.3586″ deep and 0.8481″ wide with radiused corners. The end of each lower stem cavity flared out to a width of 0.92″ at its end proximal to the body cavity 14 . The distance from the end of this flare to the oblique wall 16 directly opposite the end of this flare was about 2.0869″. Each of the angled shaft cavities 18 had a central axis at an angle of about 47° from the main axis of the tray component 10 . The oblique wall 16 deviated from this main axis by about 47°.
EMBODIMENTS OF THE INVENTION
[0023] 1. A rigid synthetic polymer package for medical articles comprising:
[0024] (A) a rigid base having an interior surface and an exterior surface; and
[0025] (B) a cover having at least two compartments including (a) a first compartment having (i) a first interior surface adapted for movement restraining contact with a first portion of a medical article, and (ii) an opposing first exterior surface; and (b) a second compartment having (i) a second interior surface adapted for contact with a second portion of said medical article, and (ii) an opposing second exterior surface; and
[0026] said base and cover having closure means for connected said base and cover together to provide a package for enclosing a medical article having a first portion and connected second portion; said closure means being manually openable for access and removal of said article;
[0027] wherein said first and second compartments of said cover are attached to each other by a connecting hinge adapted for manual movement of said first compartment relative to the second compartment to rotate said first interior surface away from said second interior surface and which cannot be rotated about said connecting hinge to a position where said first interior surface covers said second interior surface.
[0028] 2. A package, as described in embodiment 1, wherein said base is connected to said cover by a peripheral hinge.
[0029] 3. A package, as described in embodiment 1 or 2, wherein said base has at least two compartments including (a) a first compartment having (i) a first interior surface adapted for movement restraining contact with a first portion of a medical article, and (ii) an opposing first exterior surface; and (b) a second compartment having (i) a second interior surface adapted for contact with a second portion of said medical article, and (ii) an opposing second exterior surface.
[0030] 4. A package, as described in embodiment 3, wherein said base and cover are press fit together with said first and second compartments of said base aligned with said first and second compartments of said cover.
[0031] 5. A package, as described in embodiment 3 or 4, wherein said first and second compartments of said base are attached to each other by a connecting hinge for manual movement of said first compartment relative to the second compartment to rotate said first interior surface away from said second interior surface and said connecting hinge cannot be rotated to a position where said first interior surface covers said second interior surface.
[0032] 6. A package, as described in embodiments 1-5, wherein said interior surfaces of said base and cover comprise aromatic polyether polyurethane.
[0033] 7. A package, as described in embodiments 1-6, further comprising a medical article contained within said package and comprising a medical instrument, an implant, an orthopedic implant, a hip joint femoral stem, a shoulder implant, an implant with an abrasion sensitive coating, a cutting tool, or a fixation device for stabilizing a bone fracture.
[0034] 8. A package, as described in embodiments 1-7, wherein said first compartment of said cover has first and second cavities and said second compartment has a cavity with at least one channel connecting all three cavities.
[0035] 9. A package, as described in embodiments 1-7, wherein said first compartment of said cover has first and second cavities and said second compartment of said cover has a cavity with at least one channel connecting all three cavities and said base has a first compartment having first and second cavities connected by an integrally formed hinge to a second compartment having a cavity with at least one channel connecting all three cavities; and at least one of said cover channels faces at least one of said base channels; each channel having (i) a second compartment cavity which is a longer hemi-tubular shape generally parallel to a long edge of said package; (ii) a shorter hemi-tubular shaped second cavity of said first compartment which is at an acute angle to a longitudinal axis of said long edge; and said first cavity of said first compartment connects said longer and shorter hemi-tubular cavities and said first cavity has a significantly greater width parallel to a short edge of said package than said longer and shorter hemi-tubular cavities and with a wall in alignment with the longitudinal wall of said longer hemi-tubular cavity closer to the periphery of said package; and
said closure means adapted to reversibly lock said base and cover in a face to face configuration such that said longer and shorter hemi-tubular cavities form respective longer and shorter tubular cavities; and wherein said cavities cooperate to establish a clearance which closely approximates a dimension of the largest member of said series of orthopedic stem components of different sizes.
[0038] 10. A rigid thermoplastic package component comprising;
[0039] a cover having at least two compartments including (a) a first compartment having (i) a first interior surface adapted for movement restraining contact with a first portion of a medical article, and (ii) an opposing first exterior surface; and (b) a second compartment having (i) a second interior surface adapted for contact with a second portion of said medical article, and (ii) an opposing second exterior surface; and
[0040] said base and cover having closure means for connected said base and cover together to provide a package for enclosing a medical article having a first portion and connected second portion; said closure means being manually openable for access and removal of said article;
[0041] wherein said first and second compartments of said cover are attached to each other by a connecting hinge for manual movement of said first compartment relative to the second compartment to rotate said first interior surface away from said second interior surface and said connecting hinge cannot be rotated to a position where said first interior surface covers said second interior surface.
[0042] 11. A two piece package thermoformed from a rigid thermoplastic material for the transport and handling of any one of a series of femoral stem components of different sizes for a prosthetic hip joint comprising two facing generally rectangular tray components, with each tray component having
[0043] a. at least one channel which faces an essentially identical channel in the other tray, said channels having;
i. a longer hemi-tubular section generally parallel the long edge of its tray component; ii. a shorter hemi-tubular section at an acute angle to said long edge; and iii. a transition section connecting said longer and shorter hemi-tubular sections which provides a cavity of significantly greater width parallel to the short edge of its tray than said longer and shorter hemi-tubular sections and with a wall in alignment with the longitudinal wall of said longer hemi-tubular section closer to the periphery of said tray; and
[0047] b. means which allows it to be reversibly locked to said other tray component in a face to face configuration such that said longer and shorter hemi-tubular sections form a longer and shorter tubular section,
[0048] wherein said channels and said transition section cooperate to establish a clearance which closely approximates a dimension of the largest member of said series of femoral stem components of different sizes.
[0049] 12. The two piece package described in embodiment 11 wherein each of said tray components has a hinge located approximately at the juncture of said longer hemi-tubular section and said transition section which runs parallel to the short edge of said tray component and runs the width of said tray component, thus allowing the portion of said tray component containing said transition section and said shorter hemi-tubular section to rotate out of the plane of said tray component.
[0050] 13. The two piece package described in embodiment 12 wherein said rotatable portion of each of said tray components carries reversible locking means which functions independently of the locking means which holds the portion of each of said tray components carrying said longer hemi-tubular section to each other.
[0051] 14. A package described in embodiment 11-12 wherein both of said tray components is fabricated from a laminated thermoplastic such that the surfaces which are adapted to face the femoral components to be packaged are an aromatic polyether polyurethane.
[0052] 15. A package described in embodiments 14 wherein said aromatic polyether polyurethane is melt laminated to another thermoplastic resin.
[0053] 16. A package described in embodiment 15 wherein said other thermoplastic resin is polyethylene terephthalate glycol.
[0054] The above disclosure is for the purpose of illustrating the present invention and should not be interpreted as limiting the present invention to the particular embodiments described but rather the scope of the present invention should only be limited by the claims which follow and should include those modifications of what is described which would be readily apparent to one skilled in the art. | Packaging which can accommodate medical articles such as a series of orthopedic implants e.g. femoral stem components for prosthetic hip joints which have a dimension which varies minimally across the series but which vary considerably in overali size. The packaging is designed to minimize the travel of any member of the series packaged therein such that all the packaged components in the series can pass the standard handling and shipping tests typically used by the manufacturers of medical articles such as implants and preferably comprises two thermoformed tray components which each carry three types of cavities which are interconnected and designed to be assembled with their cavities facing each other to contain the lower stem, body and angled shaft of the stem component, respectively, with the cavities for the lower stem and the body cooperating to capture a minimally varying dimension of the series. | 0 |
BACKGROUND OF THE INVENTION
My copending patent application Ser. No. 698,043 which was filed Feb. 4, 1985, is titled POWER TRANSISTOR EMITTER BALLASTING and is assigned to the assignee of the present invention. This application teaches the use of a plurality of individual small emitters connected effectively in parallel through individual ballasting resistors to create a power transistor and is incorporated herein by reference. This application also teaches a distributed sense emitter associated with the power device emitters for responding to hot spots in the power transistor.
U.S. Pat. No. 4,146,903 issued to Robert C. Dobkin on Mar. 27, 1979, and is assigned to the assignee of the present invention. Its teaching is also incorporated herein by reference. This patent teaches the incorporation of a sense emitter in a power transistor in close proximity with the power emitter. Thermal gradients are sensed by comparing the potential developed between the sense emitter and a remotely located emitter. Means are included for turning the power transistor off when the gradient exceeds some predetermined threshold value. This is done by connecting a differential amplifier having a fixed offset potential between the sense emitter and the remote emitter. The differential amplifier output is coupled to the base of the power transistor. Thus, when the potential difference exceeds the offset, the power transistor base will be pulled low so as to shut it off. This arrangement has been used successfully in the LM138 series voltage regulators and has several advantages over prior art approaches. However, it requires a remote emitter that is not heated by the power emitter, or at least is heated to a lesser degree, to produce a gradient response.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a circuit that responds to the potential on a sense emitter in a power transistor structure and reduces conduction in the power transistor when the sense emitter-base potential indicates excessive temperature.
It is a further object of the invention to employ a differential amplifier having inputs coupled between the base and sense emitter of a power transist and an output coupled to the base circuitry so that the power transistor conduction is reduced when the sense emitter-base potential indicates excessive temperature.
The emitter-base voltage of a junction transistor is an accurate indicator of junction temperature. These transistors are commonly used in power IC's as sensors to provide thermal overload protection. However, a single sensor is usally located near a relatively large power transistor and it does not respond directly to peak temperatures within the power transistor. The approach described here uses a distributed sensor serpentined throughout the power array, that does respond to peak temperature.
It is practical to bias a distributed sense emitter at a current that results in zero emitter-base potential when it is uniformly heated to 200° C. Higher temperatures cause a reversal in emitter-base potential, but heating above 200° C. can be prevented by employing control circuitry to reduce dissipation in the power transistor when the sense potential reverses as it will at higher temperatures. If only half of the sense emitter is at the peak temperature it will have to rise an additional 20° C. to 220° C. for zero sense potential. With one-tenth the sensor at peak temperature, the sense potential is zero near 250° C. Thus, peak temperature is held to a reasonable value even when severe hot spots develop within the power array. This contrasts to conventional methods where destructive temperatures can develop with worst case conditions.
An advantage of the distributed sensor is that it can respond to an over temperature condition with a delay measured in tens of microseconds rather than the several milliseconds required for a sensor located outside the array. As a result, it is not necessary to limit the power dissipation electrically as was formerly required. Electrical power limiting must be based upon expected worst case conditions with component tolerances factored in. Eliminating this power limiting not only increases peak power ratings but also increases the continuous power rating that can be guaranteed. At the same time, better control of peak junction temperature is provided. In sum, the limit is established by the actual device temperature and not a hypothetical safe operating area limit based upon assumed operating conditions.
In the circuit of the invention a differential transistor pair has its bases coupled to the base and sense emitter of a power transistor to be protected. A relatively small current is pulled out of the sense emitter to establish a sense emitter potential that is a function of its hottest portion as described above. The differential pair operates into a current mirror load to provide a single ended drive that feeds a high gain amplifier stage which incorporates a frequency compensation capacitor in the conventional op amp manner. The high gain amplifier in turn drives a control stage that is coupled between the power transistor emitter return and the base drive input. As long as the differential pair is biased by means of a sense emitter running below a critical temperature, the high gain amplifier will be below its conduction threshold and its output will be high so as to turn the control stage off. Under this condition the power transistor will operate normally. When the sense emitter temperature exceeds the critical temperature, the differential pair will drive the high gain amplifier stage into conduction which will turn the control stage on. This will reduce the power transistor bias so that no further increase in temperature will be possible. Since the entire amplifier and control circuit is linear in its operation, and has considerable gain, the critical temperature threshold will operate effectively to prevent power transistor overheating at its hottest spot. The limit is therefore established by the actual device temperature and not a hypothetical safe operating area limit.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a simplified schematic diagram of the circuit of the invention.
FIG. 2 is a schematic diagram of the circuit of the invention.
DESCRIPTION OF THE INVENTION
A simplified schematic representation of the power transistor, its sense emitter and the thermal-control circuitry is shown in FIG. 1. The sense emitter 10 shares a common base 11 with the power transistor 12. A current source 13 biases the sense emitter at a current I 1 that results in zero emitter-base potential at the desired limiting temperature. An op amp 14 serves as the controller. When the potential on the sense emitter 10 is less than the base 11, the op amp output is high and is prevented from coupling into the base circuitry by a diode 15. Should the sense emitter potential rise to that of the base, the output of the top op amp will fall, absorbing the base drive through the diode. Making the sense potential zero at the limiting temperature is a matter of convenience. A non-zero value would require developing a reference voltage in the op amp input circuitry. Were protecting the power transistor the only consideration, the design of the control amplifier would be relatively straightforward. However, in many applications it is desirable that the power transistor go into thermal limit smoothly without oscillations that can cause electrical interference or other undesirable effects. This goal has yet to be achieved with the sensor outside the array, because the thermal delay to the sensor is beyond the electrical time constants that are practical in IC's for loop compensation. With the integral sensor, stabilization of the loop is possible because of much reduced delays. However, developing the required time constants with small capacitors has required internal bias currents of around one microampere. Microampere-level circuitry that must operate properly at temperatures around 175° C. requires new design approaches. A feature of the invention is to use inverted NPN transistors to control low current nodes as will be described below. When the emitter of a transistor is used as a collector, low current gain results, but circuit techniques can be used to compensate for this. What is important is that the inverted transistor does not have the parasitic leakage current of the normal node. This parasitic leakage itself can be in the microampere range at 175° C.
While the circuit of FIG. 1 forward biases the sense emitter and senses its potential with respect to the tranistor base, it is to be understood that the sense emitter could be reverse biased and its leakage sensed. This is feasible because the reverse leakage of a PN junction is related to its temperature. This mode of operation, while possible, is not as well behaved as the preferred version described here.
The output transistor and its shutdown circuit can be regarded as a composite transistor structure as shown in the schematic of FIG. 2. The power output transistor 12 has its collector available at terminal 16. Its main emitter 17 is actually composed of a plurality of individual emitters, each one including a series ballast resistor. Resistor 18 represents the effective value of the parallel-connected emitter resistors in the struture described in copending application Ser. No. 698,043 referenced above. Thus, terminal 19 represents the output transistor emitter. Terminal 20 represents the composite transistor base.
Transistor 21 is connected as a Darlington driver, the base of which constitutes the composite transistor base at terminal 20. Resistor 22 returns the emitter of driver transistor 21 to terminal 19.
Transistors 23 and 24 form a differential pair which has its tail current I 2 set by source 25. The base of transistor 23 is coupled to the base 11 of output transistor 12 and the base of transistor 24 is coupled to the sense emitter 10. Therefore, the differential pair will respond to the differential voltage between the base 11 and the sense emitter 10 of transistor 12.
Transistors 26 and 27 are coupled together in a current mirror configuration. It will be noted that these two transistors are operated in their inverted state as will be discussed in more detail below. This means that the electrodes shown as collectors will act as emitters and the emitter electrodes will act as collectors. Transistor 28 returns the collector (inverted emitter) of transistor 27 to its base to force it to operate as a diode. Transistor 28 isolates the current mirror base current from the collector of transistor 27. Sources 29 and 30, which supply relatively small matched currents I 3 and I 4 to the current mirror, act to provide the operating bias current. I 3 and I 4 are matched and substantially smaller than I 2 .
Resistors 31 and 32 act as coupling elements which are common to the current mirror and differentially connected transistors 23 and 24.
In normal operation, when sense emitter 10 is low, virtually all of current I 2 in source 25 will flow in transistor 24. This will pull the potential of the emitter (inverted collector) of transistor 27 up. This action causes the conduction of transistor 26 to be substantially greater than transistor 27. The collector (inverted emitter) of transistor 26 will therefore be low. Conduction in transistor 26 will pull the base of transistor 33 low so as to turn it and transistor 34 off. As a result I 5 from source 35 will pull the base of transistor 36 up so as to turn it off. Current I 5 from source 35 will flow in diode connected transistor 37 and resistor 38. These latter two components, along with I 5 , are selected to develop the desired potential at the base of transistor 36. Inverted transistor 39 provides a current sink return for the emitter current in transistor 33. This current sink ensures that transistor 34 is firmly shut off when transistor 33 is off. For the above described conditions power transistor 12 will operate normally as long as the potential across the ballast resistors 18 is less than the potential across resistor 38. The peak output current is limited at a value that will not fuse the chip metallization or bond wires by limiting the drop across resistor 18.
In the event that power transistor 10 develops a hot spot, or its operating temperature generally rises, the potential at sense emitter 10 will rise toward the base potential. When the differential is zero transistors 20 and 21 will conduct equally. Thus, the potential at the emitter (inverted collector) of transistor 26 will rise and the potential at the emitter (inverted collector) of transistor 27 will fall. If transistors 26 and 27 are matched, sources 29 and 30 are matched and resistors 31 and 32 are matched, the potential at the collector (inverted emitter) of transistor 26 will be insufficient to turn transistors 33 and 34 on. However, a further increase in temperature will cause the potential of sense emitter 10 to exceed the base 11 potential of transistor 12. In this region, near the shutdown condition, the differential amplifier will be in its highest gain state. With this temperature increase the current in transistor 26 will be reduced and transistor 27 current will be increased. When the conduction of transistor 26 is sufficiently reduced, source 29 will pull the base of transistor 33 up and supply current thereto. This will turn transistor 33, and hence transistor 34, on so that current from source 5 will flow in transistor 34. When the conduction in transistor 34 approaches the current in source 35, the base of transistor 36 will be pulled low thereby turning it on. When this occurs, the base of driver transistor 21 will be pulled down so as to control the current in transistor 12.
Capacitor 41 is connected between the input and output of the Darlington pair, transistors 33 and 34, to provide frequency compensation of the shutdown amplifier. This is desirable for stability of the circuit.
The capacitor value required for 41 depends on the transconductance of transistors 26 and 27, with lower operating currents giving lower transconductance and requiring smaller capacitance. The operating current of transistors 26 and 27 cannot be reduced so low that parasitic leakages on the active collectors (inverted emitters) affect bias currents at temperatures near 175° C. The inverted connection puts the tub leakage current on the collectors of transistors 23 and 24 which are operating at high current so that microampere-level leakages have negligible effects. This done, parasitic leakages on the active collectors of transistors 26 and 27 can be reduced to sub-microampere levels with careful design.
EXAMPLE
The circuit of FIG. 2 was constructed in IC form using conventional PN junction isolated monolithic silicon components. The NPN transistors were of vertical double diffused construction and the PNP transistors were of convention lateral construction. The following component values were used.
______________________________________COMPONENT VALUE UNITS______________________________________Resistor 18 0.15 ohmsResistor 22 200 ohmsCurrent Sink 13 100 microamperesCurrent Source 25 200 microamperesCurrent Sources 29, 30 1 microampereResistors 31, 32 800 ohmsCurrent Source 35 750 microamperesResistor 38 2.3k ohmsCapacitor 41 20 picofarads______________________________________
The circuit acted to limit the output transistor current when the sense emitter (at any point along its length) exceeded about 225° C. Since there is a time lag between the generation of heat and its arrival at the nearby sense emitter, the device response to narrow pulses is considerably enhanced by placing the sense emitter close to the power emitter. Whereas, the power transistor was rated at 90 watts at 300° K. it could dissipate 120 watts for a 10 ms pulse, 240 watts for a 1 ms pulse and 600 watts for an 0.2 ms pulse.
The invention has been described and a working example detailed. When a person skilled in the art reads the foregoing description, alternatives and equivalents, within the spirit and intent of the invention, will be apparent. Accordingly, it is intended that the scope of the invention be limited only by the following claims. | A thermal shutdown circuit for use with a high power transistor which incorporates a sense emitter. A differential amplifier is driven from the transistor base and the sense emitter and has an output that is coupled to the power transistor base. When the sense emitter potential exceeds the base potential, the amplifier output will pull the base down so as to limit the current in the power transistor. For a silicon transistor, the circuit will act to limit the hottest portion of the sense emitter to a maximum of about 250° C. When there are no hot spots and the sense emitter is heated uniformly, heating of the transistor will be limited to about 200° C. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for use with soil/groundwater sampling equipment, and in particular, to an expendable protective sleeve and method for use to keep soil samplers and bore casings free from debris and other undesirable materials, and to prevent the development of negative pore pressure upon removal of the sampling device.
2. Background Art
It has become common to obtain groundwater and soil samples from various locations. The soil samples may be used to determine if an area is suitable for construction of buildings, roadways, etc. Soil and groundwater samples my be used to determine if groundwater and/or soil contamination may be present.
When analyzing an area, it is important to collect soil and groundwater samples which have not been disturbed or tainted. The collection of undisturbed soil samples is prerequisite for proper engineering analysis of samples which have not been cross-contaminated from overlying strata subsurface contamination.
When taking soil and groundwater samples, it is common to use an auger which bores a hole into the earth. As the auger is moved downwardly, samples may be taken for analysis to determine soil characteristics and in what zones contamination may be present. To facilitate such sampling, it is common to use an auger with a hollow cylindrical center which can be used to carry a sampling device.
During the collection of soil and groundwater samples from the various types of bore holes, saturated soils commonly invade the bore hole or the bore hole casing causing delays in the boring operation and then uncertainty as to the validity of the data attained from the sampling process. Those skilled in the art will appreciate that a disturbed or tainted sample is of little use. Thus, a variety of techniques have been used to prevent this phenomenon.
One common technique includes placing water within the bore hole to overcome external hydrostatic pressure. In collecting environmental samples, however, the placement of clean water into the bore hole can render the test results suspect and is often not practical. First, the water may dilute or spread the contaminants for which the sample is being taken, thereby giving an artificially low contamination reading when the soil is analyzed. Second, when drilling in very permeable or sandy soil, additional water must be added frequently to prevent the soil from entering into the auger. The large quantities of water raise the dilution concerns discussed above. In remote locations the requirement of additional water is often also impractical or sometimes impossible, as there is often not a convenient source of water which is known to be pure. Obviously, pumping water from a stream or other natural water source is not desirable, as the water itself may be contaminated, thereby increasing the chance of inaccurate results.
Another technique involves suspending a metal plug from a drill rod that is advanced concurrently with the auger in the bore hole. When the desired depth is obtained, the plug is removed from the auger to allow soil or groundwater sampling. Unfortunately, when the metal plug is removed from the auger, negative pressure is often developed. This is especially true in saturated soils. The negative pressures draws groundwater, sand and other debris into the bore hole plugging the auger and preventing sampling until the auger has been unplugged.
In an attempt to overcome this concern, yet another technique to inhibit the invasion of soil and groundwater into the sample collection device prior to reaching the desired sampling depth involves the placement of tape over the open end of the sample collection device. This technique tends to inhibit the invasion of soil and groundwater into the sample collection device. However, the technique does not inhibit the development of a negative pressure when the sampler is removed from the bore hole, thus allowing groundwater, sand, or other contaminants to be draw into the auger and thereby potentially taint any further samples.
Thus there is a need for an apparatus and method for preventing soils and water from being drawn into a hollow auger thereby plugging the auger. Such an apparatus should be inexpensive to use and expendable. Such an apparatus should also not interfere with subsequent drilling/sampling.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an apparatus and method for inhibiting sand and other debris from plugging the bore hole and auger during the collection of soil and groundwater samples.
It is another object of the present invention to provide an apparatus and method which inhibits the collapsing of bore hole sidewalls below the leading edge of the auger during collection of soil and groundwater samples.
It is an additional object of the present invention to provide an apparatus and method which increases the speed of the sample collection process.
It is yet another object of the present invention to facilitate the collection process by allowing suspension of the sample collection device in the bore hole during advancement of the auger until a desired sampling depth is obtained without allowing the bore hole to be contaminated by unwanted debris.
It is an additional object of the present invention to prevent the invasion of contaminated soil and groundwater into the sample collection device as the collection device is lowered to the desired sampling depth.
It is yet another object of the present invention to provide such an apparatus and method which is inexpensive and easy to use.
These and other objects and advantages will be apparent from the present invention wherein an expendable protective sleeve is disposed within the auger forming the bore hole so as to cover the sample collection device and inhibit the flow of sand, soil or groundwater between the auger and sample collection device. The sleeve comprises an elongate portion typically formed in the shape of a cylinder having first and second ends. The first end is closed by a solid covering member, while the second end remains open.
In use the sleeve is slid onto the lower end of a sample collection device by placing the collection device in the open second end of the sleeve and moving the collection device downwardly, adjacent to the first, closed end of the sleeve. The soil sample collection device may then be placed in the auger with the open end disposed at the bottom.
In accordance of one aspect of the invention the sleeve is made of a water resistant, yet destructible material such as polyethylene or polypropylene. When the sampling device is ready to be used, is pushed or driven so that its lower end penetrates through the solid covering member in the first end of the sleeve and into contact with the soil or groundwater at the desired sampling depth. The sampling device may then be withdrawn and the undisturbed soil or groundwater contained therein analyzed for soil characteristics or pollutants.
In addition to preventing soil from entering into the sample collection device while prior to positioning at the desired depth, and preventing soil or groundwater from entering between the sample collection device and the auger, the sleeve also helps to prevent a negative pressure from forming within the bore hole when the sampling device is withdrawn. With traditional drilling equipment, the withdrawal of the sample collection device was often accompanied by a negative pressure (suction) which caused the bore hole to collapse and cause soil and groundwater to enter and plug into the central bore of the auger. The soil in such a position prevents the collection of additional soil samples.
The sleeve, by remaining in place while the sample collection device is withdrawn, lessens the likelihood that a negative pressure will develop. The sleeve also helps resist any collapse of the bore hole below the leading edge of the auger.
If samples at different depths are desired, the first sample will be taken as indicated above. The auger will then be advanced down to a position just above the site of the next sample with a second sample collection device and sleeve mounted thereabout. As the auger drills further into the soil, the sleeve of the first sample holder is destroyed. Thus, it is beneficial to form the sleeve from a material which will not contaminate either the soil or the groundwater which is being tested.
In accordance with the principals of the present invention, the method of using the sleeve includes sliding the sleeve onto the sample collection device and positioning the collection device so that the sleeve is disposed between the collection device and the auger. In such a position, the sleeve prevents groundwater and soil from extending upwardly therein. Once the sample collection device and sleeve are disposed within the auger, drilling may begin. At the desired depth, the sample collection device is pushed through the sleeve and the sample obtained. The sample collection device is then removed. The auger is then withdrawn, or the auger is advanced to additional testing positions and a sample collection device with a sleeve moved into position to take another sample.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a auger casing which is made in accordance with the teachings of the prior art;
FIG. 2 shows a cross-sectional view of an auger with a rod and bit disposed therein in accordance with the teachings of the prior art;
FIG. 3 shows a cross-sectional view of the prior art auger of FIG. 1, with a prior art sample collection device and the sleeve of the present invention;
FIG. 3A shows a cross-sectional view of the auger of FIG. 3, with the sample collection device and protective sleeve extending down into the soil into a position common to soil sampling techniques; and
FIG. 4 shows a perspective view of an expendable protective sleeve for soil samples made in accordance with the teachings of the present invention.
DETAILED DESCRIPTION
Reference will now be made to the drawings in which the various elements of the present invention will be given numeral designations and in which the invention will be discussed so as to enable one skilled in the art to make and use the invention. It is to be understood that the following description is only exemplary of the principles of the present invention, and should not be viewed as narrowing the pending claims.
Referring to FIG. 1, there is shown a perspective view of a hollow-stem auger, generally indicated at 10. The auger 10 includes an elongate, cylindrical central shaft 14 defining a hollow portion (not shown). The cylindrical shaft 14 has an upper end 18 which attaches to a drilling shaft (not shown) so that the drilling shaft rotates the auger 10 as the drilling shaft rotates.
At an opposite end of the auger 10 is a receptacle 22 for receiving a cutter head, such as that generally indicated at 26. As the auger 10 rotates about its long axis A--A, the cutter head 26 cuts through the soil. As shown in FIG. 1, the cutter head 26 is the type commonly referred to as a finger type. The cutter head 26 gets its name from the elongate fingers 30 which extend downwardly and cut through the soil. Those skilled in the art will appreciate that there are several other types of cutter heads which may be used.
Disposed about the central shaft 14 of the auger 10 is a flighting 34 which lifts cut soil out of the bore hole formed by the auger. Thus, the flighting 34 helps to prevent the auger 10 from getting clogged with cut soil.
Referring now to FIG. 2, there is shown a cross-sectional view of the auger 10 and a rod 40 and bit 44 disposed therein. As the auger 10 rotates, the rod 40 and bit 44 are rotated in like directions to penetrate the soil. The bit 44 also helps to prevent the flow of fluids into the central hollow 50 where it may contaminate soil or groundwater samples to be taken further down in the bore hole.
When the appropriate depth has been reached within the soil, the rod 40 and bit 44 are removed from the central hollow 50 of the auger 10 to allow a soil/groundwater sample collection device (not shown) to be passed down through the central hollow 50 and into contact with the soil or groundwater to be sampled. Unfortunately, the withdrawal of the bit 44 often creates a negative pressure (suction) within the central hollow 50 of the auger 10. This is especially true when the auger 10 extends into soil which is below groundwater. Adhesion of the saturated soil creates an effective seal such that withdrawal of the bit creates suction.
The negative pressure within the central hollow 50 draws soil and water upwardly as represented by the shaded area 60. Once the water or soil has entered the auger 10, it must be removed. If it is not, subsequent soil and groundwater samples may not be reliable, as the sampling container will first be filled with the water or soil drawn in, rather than the undisturbed soil below the auger 10.
Referring now to FIG. 3, there is shown cross-sectional view of the prior art auger 10 of FIGS. 1 and 2. The auger includes the central shaft 14 with a flighting 34 disposed thereabout. Disposed in the central hollow 50 of the central shaft 14 is the rod 40 and a soil sample collection device 70. Those skilled in the art will appreciate that there are numerous different types of soil sample and groundwater collection devices 70. For example, FIG. 3 shows a collection device 70 which has a hemispherical spring 74 having a plurality of cuts formed therein so that a plurality of fingers 78 formed thereby can deflect out of the way as a soil sample (not shown) enters the soil sample collection device 70 from an open lower end 82. Once the soil sample has passed the hemispherical spring 74 and into a holding portion 86, the fingers 78 return to their original position and prevent the soil sample from falling out. Other common types of soil sample collection device include trap valve type and other similar arrangements.
Those skilled in the art will appreciate that the major problem with such sample collection devices 70 is the risk that soil will begin to accumulate in the holding portion 86 of the device as the auger 10 is driven downwardly. For this reason, those operating the equipment generally have avoided placing the collection device 70 into the auger 10 until the auger is disposed above the desired location. The collection device 70 is then forced downwardly by the rod 40 into the undisturbed soil below the auger 10.
In accordance with the principles of the present invention, it has been found that the auger 10 can be operated with the soil sample collection device 70 in place without collecting unwanted soil by using a protective sleeve 90. The sleeve 90 has first and second ends, 92 and 96 respectively, the first end being closed by a covering member 100. The second end 92 is open so that the soil sample collection device 70 can be slid into the sleeve 90.
When the protective sleeve 90 is nested about the soil sample collection device 70 soil is not able to work its way up into the collection device. By removing this risk, the samples taken with the collection device 70 are generally more reliable. Additionally, the sleeve 90 adds little extra work other than the few seconds necessary to place it about the collection device 70.
Referring now to FIG. 3A, there is shown a fragmented cross-sectional view of the invention as shown in FIG. 3, but with the soil sample collection device 70 deployed in a collecting position. Because it is important to obtain undisturbed soil samples, it is necessary to extend the soil sampling collection device 70 below the end of the auger 10. This is usually accomplished by applying a downward force with the rod 40 which is sufficient to drive the soil sample collection device 70 to penetrate the soil. Those skilled in the art will recognize that there are specific standards for the amount of force used and the number of impacts made when driving the device 70 into the ground.
As the soil sample collection device 70 is driven into the ground, the force causes it to puncture the covering member 100 at the first end 92 of the sleeve 90. Once the lower end 82 of the collection device 70 punctures the covering member 100, soil can freely move through the lower end and into the holding portion 86 as indicated by the arrow 104.
Once the soil sample collection device 70 has been driven to the desired depth, the device can be withdrawn from the bore hole and the sample removed. Another soil sampling device, with a sleeve disposed thereon, may then be moved down the central hollow 50 of the auger 10 and adjacent the cutter head 26.
Typically, the sleeve 90 will remain in the hole formed by the soil sample collection device 70. In such a position, the sleeve 90 serves several important functions. One of the major problems with such sampling devices is that they create a negative pressure as they are withdrawn from the soil. The negative pressure can cause the walls of the bore hole to collapse, and can even result in soil or water being drawn up into the auger 10. The sleeve 90, however, minimizes the risk of a negative pressure being developed. The sleeve also inhibits the ability of the walls of the bore hole to collapse as the sample collection device 70 is withdrawn, further reducing the potential of soil plugging the auger.
Once the sample collection device 70 is withdrawn and replaced (when additional sampling is desired), the auger 10 will generally shred the sleeve 90 as it advances down to the position of the next sample. Thus, the second or replacement sample collection device will have its own sleeve.
Referring now to FIG. 4, there is shown a perspective view of a sampling sleeve made in accordance with the principles of the present invention. The sleeve 90 includes the first end 92 which is closed by the cover member 100, and the open second end 96 for sliding about the soil sample or groundwater sample collection device shown in FIGS. 3 and 3A. To receive the soil sample collection device, the inner diameter of the sleeve 90 must be slightly larger than the outer diameter of the collection device. It is preferred that the fit of the sleeve 90 about the collection device be relatively snug to prevent water from collecting between the sleeve and the collection device, but not so tight that the sleeve 90 will cling to the collection device as it is withdrawn through the auger and up the bore hole.
Because the sleeve 90 must resist the tendency of soils to enter into the collection device, the sleeve should be made of a durable material. While polyethylene and polypropylene have been mentioned, many other durable materials could also be used. Additionally, because the soil sampling collection devices often pass through water saturated soils, the sleeve 90 is preferably made with water resistant or waterproof materials. Those skilled in the art will be familiar with many different materials and will be able to identify advantages and disadvantages to each in light of the present disclosure.
Thus there is disclosed an expendable protective sleeve and a method for using the same for soil and groundwater sampling. Those skilled in the art will recognize numerous modifications which can be made without departing from the scope and spirit of the present invention. The appended claims are intended to cover such modifications. | A method for obtaining saturated soil samples includes conventional drilling equipment with a central hollow which receives a conventional soil sample collection device. An elongate sleeve with a closed end is nested about the sample collection device to prevent soil from entering the sample device before it is in position adjacent the soil to be sampled. Once in position, force is applied to the sample collection device to drive it into the soil. As the sample collection device is driven into the soil, it penetrates through the sleeve. The sample collection device is then withdrawn, leaving the sleeve in the hole formed by the collection device to help prevent collapse of the walls. The sleeve also helps to minimize any negative pressures which might develop as the sample collection device is withdrawn and which can result in soil plugging the central hollow of the auger. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable.
BACKGROUND OF THE INVENTION
The present invention relates in general to centrifugal pumping devices for circulatory assist and other uses, and, more specifically, to an improved method and apparatus for maintaining a centered position of a magnetically-levitated impeller.
Many types of circulatory assist devices are available for either short term or long term support for patients having cardiovascular disease. For example, a heart pump system known as a left ventricular assist device (LVAD) can provide long term patient support with an implantable pump associated with an externally-worn pump control unit and batteries. The LVAD improves circulation throughout the body by assisting the left side of the heart in pumping blood. One such system is the DuraHeart® LVAS system made by Terumo Heart, Inc., of Ann Arbor, Mich. The DuraHeart® system employs a centrifugal pump with a magnetically levitated impeller to pump blood from the left ventricle to the aorta. The impeller can act as a rotor of an electric motor in which a rotating magnetic field from a multiphase stator couples with the impeller and is rotated at a speed appropriate to obtain the desired blood flow through the pump.
A typical cardiac assist system includes a pumping unit, drive electronics, microprocessor control unit, and an energy source such as rechargeable batteries and/or an AC power conditioning circuit. The system is implanted during a surgical procedure in which a centrifugal pump is placed in the patient's chest. An inflow conduit is pierced into the left ventricle to supply blood to the pump. One end of an outflow conduit is mechanically fitted to the pump outlet and the other end is surgically attached to the patient's aorta by anastomosis. A percutaneous cable connects to the pump, exits the patient through an incision, and connects to the external control unit.
A control system for varying pump speed to achieve a target blood flow based on physiologic conditions is shown in U.S. Pat. No. 7,160,243, issued Jan. 9, 2007, which is incorporated herein by reference in its entirety. A target blood flow rate may be established based on the patient's heart rate so that the physiologic demand is met. The control unit may establish a speed setpoint for the pump motor to achieve the target flow.
A typical centrifugal pump employs a design which optimizes the shapes of the pumping chamber and the impeller rotating within the chamber so that the pump operates with a high efficiency. By employing a magnetic bearing (i.e., levitation), contactless rotation of the impeller is obtained and the pumping chamber can be more completely isolated from the exterior of the pump. The impeller typically employs upper and lower plates having magnetic materials (the terminology of upper and lower being arbitrary since the pump can be operated in any orientation). A stationary magnetic field from the upper side of the pump housing attracts the upper plate and a rotating magnetic field from the lower side of the pump housing attracts the lower plate. The forces cooperate so that the impeller rotates at a levitated position within the pumping chamber. Features (not shown) may also be formed in the walls of the pumping chamber to produce a hydrodynamic bearing wherein forces from the circulating fluid also tend to center the impeller. Hydrodynamic pressure grooves adapted to provide such a hydrodynamic bearing are shown in U.S. Pat. No. 7,470,246, issued Dec. 30, 2008, titled “Centrifugal Blood Pump Apparatus,” which is incorporated herein by reference.
The impeller has an optimal centered location within the pumping chamber with a predetermined spacing from the chamber walls on each side. Maintaining a proper spacing limits the shear stress and the flow stasis of the pump. A high shear stress can cause hemolysis of the blood (i.e., damage to cells). Flow stasis can cause thrombosis (i.e., blood clotting). In order to ensure proper positioning, active monitoring and control of the impeller position has been employed by adjusting the stationary magnetic field. However, position sensors and an adjustable magnetic source occupy a significant amount of space and add to the complexity of a system. With an implanted system, it is desirable to miniaturize the pump as much as possible. It is also desirable to reduce failure modes by avoiding complexity. Thus, it would be desirable to maintain a centered position of the impeller to limit hemolysis and thrombosis without needing active control of the stationary levitating magnetic field.
SUMMARY OF THE INVENTION
In one aspect of the invention, a centrifugal pump system comprises a disc-shaped impeller rotating about an axis and having a first magnetic structure disposed at a first surface and a second magnetic structure disposed at a second surface. A pump housing defines a pumping chamber which receives the impeller. A levitation magnetic structure is disposed at a first end of the pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator disposed at a second end of the pump housing for generating a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents flowing in response to the phase voltages. A controller calculates successive commanded values for the phase voltages in response to the determined phase currents and a variable commutation angle. The angle is selected to correspond to an axial attractive force of the stator that maintains a levitation of the impeller at a centered position within the pumping chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a circulatory assist system as one example of an implantable pump employing the present invention.
FIG. 2 is an exploded, perspective view of a centrifugal pump.
FIG. 3 is a cross section showing an impeller levitated to a centered position within a pumping chamber.
FIG. 4 is a block diagram showing multiphase stator windings and a control system according to the present invention.
FIG. 5 is a flow chart showing one preferred method for controlling pump operation.
FIG. 6 is a flow chart showing one preferred method for adjusting a commutation angle.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 , a patient 10 is shown in fragmentary front elevational view. Surgically implanted either into the patient's abdominal cavity or pericardium 11 is the pumping unit 12 of a ventricular assist device. An inflow conduit (on the hidden side of unit 12 ) pierces the heart to convey blood from the patient's left ventricle into pumping unit 12 . An outflow conduit 13 conveys blood from pumping unit 12 to the patient's aorta. A percutaneous power cable 14 extends from pumping unit 12 outwardly of the patient's body via an incision to a compact control unit 15 worn by patient 10 . Control unit 15 is powered by a main battery pack 16 and/or an external AC power supply and an internal backup battery. Control unit 15 includes a commutator circuit for driving a motor within pumping unit 12 .
FIG. 2 shows a centrifugal pump unit 20 having an impeller 21 and a pump housing having upper and lower halves 22 a and 22 b . Impeller 21 is disposed within a pumping chamber 23 over a hub 24 . Impeller 21 includes a first plate or disc 25 and a second plate or disc 27 sandwiched over a plurality of vanes 26 . Second disc 27 includes a plurality of embedded magnet segments 44 for interacting with a levitating magnetic field created by levitation magnet structure 34 disposed against housing 22 a . For achieving a small size, magnet structure 34 preferably is comprised of one or more permanent magnet segments providing a symmetrical, static levitation magnetic field around a 360° circumference. First disc 25 also contains embedded magnet segments 45 for magnetically coupling with a magnetic field from a stator assembly 35 disposed against housing 22 b . Housing 22 a includes an inlet 28 for receiving blood from a patient's ventricle and distributing it to vanes 26 . Impeller 21 is preferably circular and has an outer circumferential edge 30 . By rotatably driving impeller 21 in a pumping direction 31 , the blood received at an inner edge of impeller 21 is carried to outer circumferential 30 and enters a volute region 32 within pumping chamber 23 at an increased pressure. The pressurized blood flows out from an outlet 33 formed by housing features 33 a and 33 b . A flow-dividing guide wall 36 may be provided within volute region 32 to help stabilize the overall flow and the forces acting on impeller 21 .
The cross section of FIG. 3 shows impeller 21 located at a centered position wherein disc 27 is spaced from housing 22 A by a gap 42 and impeller disc 25 is spaced from housing 22 B by a gap 43 . During pump operation, the center position is maintained by the interaction of attractive magnetic forces between permanent magnets 40 and 41 in levitation magnet structure 34 with imbedded magnetic material 44 within impeller disc 27 , and between stator assembly 35 and imbedded magnet material 45 in impeller disc 25 , and by hydrodynamic bearing forces exerted by the circulating fluid which may be increased by forming hydrodynamic pressure grooves in housing 22 (not shown). By using permanent magnets in structure 34 , a compact shape is realized and potential failures associated with the complexities of implementing active levitation magnet control are avoided. In order to properly balance impeller 21 at the centered position, however, and because other forces acting on impeller 21 are not constant, an active positioning control is still needed. In particular, the hydrodynamic forces acting on impeller 21 vary according to the rotational speed of impeller 21 . Furthermore, the attractive force applied to impeller 21 by stator assembly 35 depends on the magnitude of the magnetic field and the angle by which the magnetic field leads the impellers magnetic field position.
A typical method for controlling voltages applied to a stator in order to provide the desired rotation for a permanent magnet rotor (i.e., the impeller) is a field-oriented control (FOC) algorithm, which is also known as vector control. It is known in FOC that the stator magnetic field should lead the impeller position by 90° for maximum torque efficiency. The magnitude of the attractive force on the impeller is proportional to the magnitude of the phase currents in the stator. Phase current is adjusted by the FOC algorithm according to torque demands for the pump. Since the commutation angle is typically fixed at 90°, the resulting attractive force varies according to torque output from the pump.
The present invention varies the commutation angle in a manner to compensate for variations in attractive force that would otherwise occur as a result of changes in speed and torque. Varying the commutation angle from 90° slightly reduces overall efficiency, but has no significant affect on overall pump performance. At any particular combination of the 1) magnitude of the phase current and 2) the speed of the impeller, a modified commutation angle for generating the phase voltages applied to the stator can be determined so that the attractive force generated by the stator properly balances they hydrodynamic forces and the magnetic forces of the levitation magnets in order to keep the impeller at the centered position.
The present invention is shown in greater detail in FIG. 4 wherein a controller 50 uses field oriented control to supply a multiphase voltage signal to a stator assembly 51 shown as a three-phase stator. Individual phases A, B, and C are driven by an H-bridge inverter 52 functioning as a commutation circuit driven by a pulse width modulator (PWM) circuit 53 in controller 50 . A current sensing circuit 54 associated with inverter 52 measures instantaneous phase current in at least two phases providing current signals designated i a and i b . A current calculating block 55 receives the two measured currents and calculates a current i c corresponding to the third phase as known in the art. The measured currents are input to an FOC block 56 and to a current observer block 57 which estimates the position and speed of the impeller as known in the art. The impeller position and speed are input to FOC block 56 . A target speed or rpm for operating the pump is provided by a conventional physiological monitor 58 to FOC block 56 . The target rpm may be set by a medical caregiver or determined according to an algorithm based on various patient parameters such heart beat.
FOC block 56 generates commanded voltage output values v a , v b , and v c which are input to PWM block 53 . The v a , v b , and v c commands may also be coupled to observer 57 for use in detecting speed and position (not shown). The system in FIG. 4 generally uses conventional elements as known in the art except for modifications to FOC block 56 which alter the field oriented control algorithm so that a variable commutation angle is provided instead of the conventional 90° angle. In a preferred embodiment, a predetermined lookup table 60 is used to generate a commutation angle to be used at various operating conditions of the pump.
In a preferred embodiment, the invention proceeds according to a method as shown in FIG. 5 which highlights a portion of the field oriented control algorithm where a variable commutation angle is adopted. Thus, in step 65 the phase currents are measured. Based on the measured phase currents, the speed and position of the impeller are estimated in step 66 . The phase currents are transformed into a two-axis coordinate system to generate quadrature current values in a rotating reference frame in step 67 . In step 68 , the quadrature current vector is rotated by a desired commutation angle. This angle is selected to provide a proper centering offset from the typical 90° commutation angle according to the phase current and speed as described below. Based on the difference (i.e., error) between the quadrature current values from steps 67 and 68 , the next quadrature voltages are determined in step 69 . In step 70 , the quadrature voltages are transformed back to the stationary reference frame in order to provide the multiphase voltage commands which are output to the PWM circuit.
According to one preferred embodiment of the invention, the values for the commutation angle which are offset from 90° by a centering offset to properly balance the levitated position of the impeller are determined in advance for various operating conditions of the pump and are compiled into a lookup table for use during normal pump operation. The attractive force applied to the impeller by the stator assembly varies with the magnitude of the magnetic field and the angle by which the magnetic field leads the impeller position (i.e., the commutation angle). The magnitude of the magnetic field is directly proportional to the phase current. Phase current may preferably be characterized as the peak value for one of the measured phase currents over a sampling interval. In one preferred embodiment, a sampling interval of 1/20 seconds is used. Since the drive currents are always symmetrical, all the phases are driven with the same phase current value so that any one of the phase currents can be used. The phase current values are determined by the FOC algorithm according to the torque requirements of the motor in order to maintain the desired speed. Therefore, the phase currents cannot be used as the primary variable to adjust the axial attractive force. However, commutation angle can be arbitrarily modified to achieve a desired attractive force without otherwise degrading operation of the pump (although a slight reduction in efficiency is produced).
Entries in the lookup table to be used to determine an offset commutation angle based on the magnitude of the phase current and the current operating speed, can be obtained experimentally during the design of the centrifugal pump system. During normal pump operation, a value for the commutation angle is obtained from the lookup table during each sampling interval using a method shown in FIG. 6 . Thus, an update routine is periodically entered in step 75 according to the sampling interval. A phase current and speed characterizing the sampling interval are determined in step 76 . In addition to peak current in a single phase, a phase current characteristic such as an RMS value or an average of the square of the current could be employed. Based on the phase current characteristic and the rotational speed of the impeller, an offset commutation angle is looked up in step 77 . The offset can be stored as an absolute commutation angle or can be stored as a difference from a 90° commutation angle. The commutation angle offset is then used in step 78 for performing the field oriented control method of determining the phase voltages for driving the stator assembly until a next update for the following sampling interval.
In one preferred embodiment, the lookup table includes 16 rows corresponding to the phase current characteristic and 10 columns corresponding to speed. Each row or column covers a respective range of values and all the columns and rows together cover a full operating regime of the pump. The table values can be determined experimentally using an impeller attached to a torque meter. An attractive force measurement fixture is attached to the stator assembly. For each rpm range corresponding to a table column, the phase current characteristic (i.e., the torque) is set to a corresponding range for a table row, with the pump operating using a standard field oriented control algorithm. The commutation angle is manually adjusted while monitoring the change in attractive force until the desired attractive force is obtained. The commutation angle achieving the desired attractive force is then stored in the table.
The present invention is also useful in the context of a centrifugal pump with a levitating impeller wherein the impeller position can be sensed. Instead of a lookup table, a control loop varying the commutation angle could be employed in order to maintain the desired impeller position. | A centrifugal pump system having an impeller rotating with first and second magnetic structures on opposite surfaces. A levitation magnetic structure is disposed at a first end of a pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator at a second end of the pump housing generates a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents. A controller calculates successive commanded values for the phase voltages in response to the determined phase currents and a variable commutation angle. The angle is selected to correspond to an axial attractive force of the stator that maintains a levitation of the impeller at a centered position within the pumping chamber. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of prior filed copending provisional application Ser. No. 60/071,805, titled “Suppression of Electromagnetic Interference in Parallel Data Channels through Spread Spectrum Phase Modulation,” filed on Jan. 20, 1998 by inventors Yongsam Moon, Deog-Kyoon Jeong, and Gyudong Kim.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates generally to electronic circuitry for parallel clock and data transmission. More particularly, the present invention relates to reducing electromagnetic interference (EMI) during such transmission.
2. Description of Related Art
As electronic and computer technology continues to evolve, communication of data among different devices, either situated nearby or at a distance, becomes increasingly important. It is also increasingly desirable to provide such data communications at very high speeds, especially in view of the large amount of data required for data communications in intensive data consuming systems using graphical or video information, multiple input-output channels, local area networks, and the like. Hence, it is now more desirable than ever to provide for high speed data communications among different chips on a circuit board, different circuit boards in a system, and different systems with each other.
A problem of increasing significance for such data communications is substantial electromagnetic interference (EMI) radiation, often exceeding acceptable levels. As the number of data lines and the rate of data driving and transmission increases, the EMI emitted increases correspondingly.
An early prior art method of reducing EMI radiation involves physical shielding. Physical shielding may reduce EMI radiation, but physical shielding may be cumbersome and costly, and may not be effective enough to sufficiently reduce EMI radiation depending on the frequencies involved.
Electromagnetic interference may have an adverse influence on the operations of electronic equipment. Thus, there are strict regulations on electromagnetic emission covering both industrial and consumer electronic equipment. Recently, there is increasing pressure to reduce EMI from such equipment.
An on-board parallel clock and data channel as shown by the example in FIG. 1 is a primary source of EMI for some systems. In the following analysis, we assume a dual edge clocking scheme for simplicity and since it is more favorable to the EMI problem. In the far-field, each metal wire may be considered as a single point, and the EMI power radiated by the wire trace is calculated as P(f)∝I 2 (f)·f 2 , where f is the signal frequency and I(f) is the current through the wire. For example, assuming that 8 bit data wires carry an identical alternating 01 sequence with a clock of 62.5 megahertz (MHz) with rising and falling times of 1 nanosecond (ns), an EMI peak occurs at 812.5 MHz as shown in FIG. 2 ( c ). Note that only the current waveform shown in FIG. 2 ( b ) is related with EMI rather than the voltage waveform shown in FIG. 2 ( a ).
In order to reduce the peak EMI, either the power spectrum of EMI must be evenly spread over a wide frequency range or high frequency components of the current must be reduced.
One of the conventional techniques is direct-sequence spread spectrum (DSSS), where each data is exor'ed with a pseudo-random sequence and then exor'ed with the same sequence to recover data in the receiver. This spreads the data in frequency prior to transmission and “despreads” it at the receiver, as shown by the example illustrated in FIG. 3 .
However, the DSSS technique has a substantial disadvantages and problems. One disadvantage is that the DSSS technique can be applied to data signals, but not to a clock signal. This is because the clock signal must be glitch and jitter free. In the example shown in FIG. 3, the EMI reduction is merely to negative 19.1 dB (decibels) at 812.5 MHz, and the remaining peak arises primarily from the unspread clock line. [1 dB=10 log 10 (P 2 /P 1 ), where P 1 and P 2 represent the power of two signals.] One of the problems is that the DSSS technique requires pseudo-random (PN) code generators in both transmitter and receiver for scrambling/descrambling and synchronization between transmitter and receiver.
SUMMARY OF THE INVENTION
The above described problems and disadvantages are overcome by the present invention. The present invention relates to a new spread spectrum phase modulation (SSPM) technique that is applicable to both data and clock signals. The SSPM technique is more suitable to board level designs than the direct-sequence spread spectrum (DSSS) technique. In addition, SSPM may be combined with controlled edge rate signaling to outperform DSSS.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing a typical configuration including a transmitter, a receiver, and a channel comprising a clock line and 8 data lines.
FIG. 2 ( a ) is a graph illustrating a voltage waveform output by a pad of a transmitter to a wire of a channel.
FIG. 2 ( b ) is a graph illustrating a current waveform output by a pad of a transmitter to a wire of a channel.
FIG. 2 ( c ) is a graph illustrating a power spectrum due to the current waveform of FIG. 2 ( b ).
FIG. 3 ( a ) is a schematic diagram showing a direct-sequence spread spectrum communication system, including pseudo-random code generators within a transmitter and a receiver.
FIG. 3 ( b ) is a graph illustrating the spreading of a data signal and the non-spreading of a clock signal by way of the direct-sequence spread spectrum technique.
FIG. 3 ( c ) is a graph illustrating the reduction of the peak values in the power spectrum when the direct-sequence spread spectrum technique is applied.
FIG. 4 ( a ) is a graph illustrating phase modulation of a signal in accordance with a preferred embodiment of the present invention.
FIG. 4 ( b ) is a graph illustrating the phase of the signal dithered by a pseudo-random code in accordance with a preferred embodiment of the present invention.
FIG. 5 ( a ) is a schematic diagram illustrating a spread spectrum phase modulation communication system in accordance with a preferred embodiment of the present invention.
FIG. 5 ( b ) is a graph illustrating the improved reduction of the peak values in the power spectrum when the spread spectrum phase modulation technique is applied in accordance with a preferred embodiment of the present invention.
FIG. 6 ( a ) is a graph illustrating an output voltage waveform having an increased transition time in accordance with a preferred embodiment of the present invention.
FIG. 6 ( b ) is a graph illustrating an output current waveform having an increased transition time in accordance with a preferred embodiment of the present invention.
FIG. 6 ( c ) is a graph illustrating the further improved reduction of the peak values in the power spectrum when the transition time is increased and the spread spectrum phase modulation technique is applied in accordance with a preferred embodiment of the present invention.
FIG. 7 is a schematic diagram showing SSPM transmitter circuitry in accordance with a preferred embodiment of the present invention.
FIG. 8 ( a ) is a schematic diagram showing circuitry for a T/2 Phase Detector in accordance with a preferred embodiment of the present invention.
FIG. 8 ( b ) is a graph illustrating clock and phase detection signals in accordance with a preferred embodiment of the present invention.
FIG. 8 ( c ) is a graph of phase difference vs. control voltage variation in accordance with a preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Spread Spectrum Phase Modulation and EMI Reduction
FIG. 4 ( a ) shows a signal waveform under phase modulation. The original and unmodulated signal 402 is shown in the top line of FIG. 4 ( a ). The phase modulated, or dithered, signal 404 and its phase 406 are shown in the second and third lines of FIG. 4 ( a ).
As shown, the phase 406 varies continuously between 0 degrees (EARLY state) and negative 180 degrees (LATE state). To prevent excessive phase change between the two successive phase values (EARLY state and LATE state), a SLOW state (EARLY to LATE transition) and a FAST state (LATE to EARLY transition) are inserted between transitions to and from EARLY and LATE states. In accordance with a preferred embodiment of the present invention, the SLOW and FAST states occupy at least 16 cycles, and the phase change between two successive cycles is limited to 12 degrees. Of course, within the scope of the present invention, the number of cycles occupied and the phase change between two successive cycles may vary from the particular numbers above.
FIG. 4 ( b ) is a graph illustrating the phase 408 of the signal dithered by a pseudo-random code (PN sequence) 410 in accordance with a preferred embodiment of the present invention. For purposes of illustration, the pseudo-random sequence 410 shown starts with the sequence 011010. Techniques for generating such pseudo-random sequences are known to those of ordinary skill in the pertinent art.
When the phase modulation is controlled by a PN sequence 410 such as shown in FIG. 4 ( b ), the resultant power spectrum will be spread like the power spectrum in FIG. 5 ( b ). The power spectrum in FIG. 5 ( b ) has peaks with a maximum power of negative 14.6 dB 1 GHz. In comparison, the power spectrum in FIG. 2 ( b ) has peaks with a maximum power of 0 dB. Thus, applying spread spectrum phase modulation in this way to the signal results in a magnitude 14.6 dB reduction in peak EMI.
Although the 14.6 dB reduction from this implementation of SSPM is substantial, it is less than the 19.1 dB reduction from the implementation of DSSS shown in FIG. 3 ( c ). Nevertheless, this implementation of SSPM is advantageous over DSSS because, unlike DSSS, SSPM does not require a pseudo-random code generator in the receiver and so requires simpler circuitry in comparison to the circuitry for DSSS shown in FIG. 3 ( a ).
A SSPM transmitter circuit 502 for parallel transmission of a clock signal and multiple data signals and for phase modulation of those clock and data signals is shown in FIG. 5 ( a ). The circuit 502 includes: a clock signal source 504 for generating the clock signal (CLK); a plurality of data signal sources 506 for generating the multiple data signals (D 0 , D 1 , D 2 , . . . , D 7 ); a control voltage source 508 for generating a control voltage (Vctrl 1 ); a first voltage-controlled delay line 510 coupled to the clock signal source 504 to receive the clock signal and coupled to the control voltage source 508 to receive the control voltage, the first voltage-controlled delay line delaying the clock signal according to the control voltage; and a plurality of voltage-controlled delay lines 512 coupled to the plurality of data signal sources 506 to receive the multiple data signals and coupled to the control voltage source 508 to receive the control voltage, the plurality of voltage-controlled delay lines delaying the multiple data signals according to the control voltage. The output of the circuit 502 is also shown in FIG. 5 ( a ). The first voltage-controlled delay line 510 outputs a dithered clock (dithered CLK) signal 514 . The plurality of voltage-controlled delay lines 512 output dithered data signals 516 .
Thus, the spread spectrum phase modulation (SSPM) technique can be applied to both clock and data without skew errors between data and clock as shown in FIG. 5 ( a ). The absence of skew errors is achieved by phase-modulating the clock and data through voltage-controlled delay lines (VCDLs 510 and 512 ) of which delays are controlled by the same control voltage. It is desirable that the phase difference between maximum and minimum delays applied by the VCDLs should be 180 degrees. This is because as the phase difference between maximum and minimum delays gets away from 180 degrees, the EMI reduction gets smaller according to our simulations.
Effect of Increased Transition Time (ITT) of Data Outputs
In order to reduce the high frequency component of the current, increasing the transition time (t s ) is desirable. However, the slow edge rate cannot be applied to a clock signal, so EMI reduction on a clock signal is not expected.
Since the negative 19.1 dB peak at 812.5 MHz in the case of DSSS is due primarily to the clock signal, no further peak reduction would occur by increasing the transition time (t s ) in the case of DSSS. In contrast, since the negative 14.6 dB peak at 1 GHz in the case of SSPM is not due primarily to the clock signal, that peak will be substantially further reduced occur by increasing the transition time (t s ) in the case of SSPM.
FIG. 6 ( a ) is a graph illustrating an output voltage waveform having an increased transition time (t s ) in accordance with a preferred embodiment of the present invention. The increased transition time (t s ) is more distinctly shown in FIG. 6 ( b ) which shows the corresponding output current waveform. The transition time (t s ) for the waveforms shown in FIGS. 6 ( a ) and 6 ( b ) is 5 nanoseconds (ns). In comparison, the transition time (t s ) for the waveforms shown in FIGS. 2 ( a ) and 2 ( b ) is 1 nanosecond (ns).
FIG. 6 ( c ) is a graph illustrating the further improved reduction of the peak values in the power spectrum when the transition time (t s ) is increased to 5 ns, and the spread spectrum phase modulation technique is applied in accordance with a preferred embodiment of the present invention. As can be seen from FIG. 6 ( c ), the peak at 1 GHz is further reduced to negative 31.3 dB.
FIG. 7 is a schematic diagram showing SSPM transmitter circuitry 700 in accordance with a preferred embodiment of the present invention. The transmitter circuitry 700 includes the phase selection circuit (PSC) 508 and a delay lock loop (DLL) 702 . Both the PSC 508 and the DLL 702 supply control voltages to a voltage-controlled delay line (VCDL) 510 . The same or similar circuitry would be used to supply control voltages to the other voltage-controlled delay lines 512 .
The transmitted signal (the CLK signal in the instance shown in FIG. 7) is modulated by the VCDL 510 . The delay applied by the VCDL 510 is controlled by two control voltages: Vctrl 1 and Vctrl 2 .
The generation of Vctrl 1 by the PSC 508 is controlled by a switching algorithm, and Vctrl 1 is used for interpolating the delay applied by the VCDL 510 . For example, the VCDL 510 generates a minimum delay (0) when Vctrl 1 is switched to V 15 . As another example, the VCDL 510 generates a maximum delay (T/2) when Vctrl 1 is switched to V 0 . According to a preferred embodiment of the present invention, Vctrl 1 is continuously switched from V 15 to V 14 , V 13 , V 12 , and so on to V 0 , then to V 1 , V 2 , V 3 , and so on to V 15 , etc.
The DLL 702 generates Vctrl 2 corresponding to a half period (T/2) delay difference. The DLL 702 includes a T/2Phase Detector 704 with CLK 0 and CLK 1 input signals, and UP and DOWN output signals. The DLL 702 adjust s Vctrl 2 until a rising edge of the CLK 0 signal and the falling edge of the CLK 1 signal are aligned.
As Vctrl 1 is continuously switched between V 15 and V 0 according to the switching algorithm using a pseudo-random sequence 410 , the delay applied by the VCDL 510 varies between 0 and T/2. Furthermore, because a low-pass filter 706 is used in the generation of Vctrl 1 , the phase and delay vary smoothly.
FIG. 8 ( a ) is a schematic diagram showing circuitry for a T/2 Phase Detector 704 in accordance with a preferred embodiment of the present invention. The T/2 Phase Detector 704 comprises a dynamic phase detector that has two input signals CLK 0 and CLK 1 and two output signals UP and DOWN.
For generating the UP signal output, the CLK 1 signal is input to a first inverter 802 and to gates of a first PMOS transistor 804 and a first NMOS transistor 806 . The source of the first PMOS transistor 804 is coupled to a supply voltage, and the drain of the first PMOS transistor 804 is coupled to the source of a second PMOS transistor 808 . The source of the first NMOS transistor 806 is coupled to the drain of the second PMOS transistor 808 , and the drain of the first NMOS transistor 806 is coupled to an electrical ground. The CLK 0 signal is input to a second inverter 810 .
In addition, the output of the first inverter 802 is coupled to a gate of a third PMOS transistor 812 . The output of the second inverter 810 and the gate of the second PMOS transistor 808 are coupled to a gate of a second NMOS transistor 814 . The node between the drain of the second PMOS transistor 808 and the source of the first NMOS transistor 806 is coupled to the gate of a third NMOS transistor 816 .
Furthermore, the source of the third PMOS transistor 812 is coupled to a supply voltage, and the drain of the third PMOS transistor is coupled to an input of a third inverter 818 . The source of the second NMOS transistor 814 is also coupled to the input of the third inverter 818 , and the drain of the second NMOS transistor 814 is coupled to the source of the third NMOS transistor 816 . The drain of the third NMOS transistor 816 is coupled to an electrical ground. Finally, the output of the third inverter 818 comprises the UP output signal.
For generating the DOWN signal output, the circuitry is the same as that for generating the UP signal, except that the CLK 0 and CLK 1 input signals are reversed as shown in the bottom half of FIG. 8 ( a ).
The circuitry shown in FIG. 8 ( a ) comprises a dynamic phase detector with fewer transistors and higher precision than prior dynamic phase detectors. Owing to the high precision of its dynamic logic operation, the T/2 Phase Detector 704 can operate without any phase offset.
FIG. 8 ( b ) is a graph illustrating clock and phase detection signals in accordance with a preferred embodiment of the present invention. As shown in FIG. 8 ( b ), the widths of UP and DOWN pulses are proportional to the phase difference of the inputs CLK 0 and CLK 1 . Further, there are no pulses in lock state.
FIG. 8 ( c ) is a graph of phase difference vs. control voltage variation in accordance with a preferred embodiment of the present invention. | A new spread spectrum phase modulation (SSPM) technique is applicable to both data and clock signals. The SSPM technique is more suitable to board level designs than the direct-sequence spread spectrum (DSSS) technique. In addition, SSPM may be combined with controlled edge rate signaling to outperform DSSS. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the decontamination arts including the sterilization arts. It finds particular application in conjunction with the decontamination of medical devices, especially medical devices such as endoscopes and other devices having channels or lumens that must be decontaminated after use.
[0002] Endoscopes and similar medical devices having channels or lumens formed therethrough are being used on an ever increasing basis in the performance of medical procedures. The popularity of these devices has led to calls for improvements in the decontamination of these devices between use, both in terms of the speed of the decontamination and the effectiveness of the decontamination.
[0003] One popular method for cleaning and disinfection or sterilization of such endoscopes employs an automated endoscope reprocessor which both washes and then disinfects or sterilizes the endoscope. Typically such a unit comprises a basin with a selectively opened and closed cover member to provide access to the basin. Pumps connect to various channels through the endoscope to flow fluid therethrough and an additional pump flows fluid over the exterior surfaces of the endoscope. Typically, a detergent washing cycle is followed by rinsing and then a sterilization or disinfection cycle and rinse. Various connections must be made to the endoscope to achieve flow through its channels. If any of the connections leaks the process may not work properly possibly leaving the endosope contaminated. Typically, such automated systems check for blockages in the channels, but such testing can be fooled if one of the connections is not tight.
SUMMARY OF THE INVENTION
[0004] A method of detecting proper connection of fixtures to one or more channels in an endoscope according to the present invention comprises the steps of:
[0005] placing a first opening into at least one of the one or more channels into a liquid;
[0006] having a gas within the channel;
[0007] drawing a vacuum on the gas through a second opening into the channel and thereby drawing some of the liquid into the channel;
[0008] detecting for air leaking into the channel.
[0009] Preferably, the step of detecting for air leaking into the at least one channel comprises monitoring the pressure within the channel. If it falls below a given amount in a given time period an indication can be given that the channel is leaking.
[0010] When the endoscope has two channels and where one of the fixtures separates theses channels from each other internally, the method preferably further includes the step of individually testing each of the two channels so as to detect gas leaking past the fixture which separates the two channels from each other. If leakage is detected in testing each of the two channels an indication is given that the fixture separating the two channels is leaking.
[0011] Preferably, a first one of the fixtures connects to the second opening and this fixture is exposed to atmosphere, and if leakage of air into the channel is detected an indication is given that first one of the fixtures is leaking. If leakage of air into the channel is detected an indication is given to a user that the channel failed the leakage test. Such indication is preferably provided visually on a screen.
[0012] Preferably, the first opening is at a distal end of an endoscope.
[0013] In one aspect of the invention, the step of detecting for air leaking into the at least one channel comprises monitoring for air bubbles within the at least one channel. Such a monitor could comprise a turbidity meter or even a visual inspection by the user. Alternatively, the step of detecting for air leaking into the at least one channel comprises monitoring a flow of the liquid through the at least one channels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention may take form in various components and arrangements of components and in various steps and arrangements of steps. The drawings are for purposes of illustrating preferred embodiments only, and are not to be construed as limiting the invention.
[0015] [0015]FIG. 1 is a front elevational view of a decontamination apparatus in accordance with the present invention;
[0016] [0016]FIG. 2 is a diagrammatic illustration of the decontamination apparatus shown in FIG. 1, with only a single decontamination basin shown for clarity; and,
[0017] [0017]FIG. 3 is a cut-away view of an endoscope suitable for processing in the decontamination apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] [0018]FIG. 1 shows a decontamination apparatus for decontaminating endoscopes and other medical devices which include channels or lumens formed therethrough; FIG. 2 shows the apparatus in block diagram form. The decontamination apparatus generally includes a first station 10 and a second station 12 which are at least substantially similar in all respects to provide for the decontamination of two different medical devices simultaneously or in series. First and second decontamination basins 14 a , 14 b receive the contaminated devices. Each basin 14 a , 14 b is selectively sealed by a lid 16 a , 16 b , respectively, preferably in a microbe-blocking relationship to prevent the entrance of environmental microbes into the basins 14 a , 14 b during decontamination operations. The lids can include a microbe removal or HEPA air filter formed therein for venting.
[0019] A control system 20 includes one or more microcontrollers, such as a programmable logic controller (PLC), for controlling decontamination and user interface operations. Although one control system 20 is shown herein as controlling both decontamination stations 10 , 12 , those skilled in the art will recognize that each station 10 , 12 can include a dedicated control system. A visual display 22 displays decontamination parameters and machine conditions for an operator and at least one printer 24 prints a hard copy output of the decontamination parameters for a record to be filed or attached to the decontaminated device or its storage packaging. The visual display 22 is preferably combined with a touch screen input device. Alternatively, a keypad or the like is provided for input of decontamination process parameters and for machine control. Other visual gauges 26 such as pressure meters and the like provide digital or analog output of decontamination or medical device leak testing data.
[0020] [0020]FIG. 2 diagrammatically illustrates one station 10 of the decontamination apparatus. Those skilled in the art will recognize that the decontamination station 12 is preferably similar in all respects to the station 10 illustrated in FIG. 2. However, the station 12 has not been shown in FIG. 2 for clarity. Further, the decontamination apparatus can be provided with a single decontamination station or multiple stations.
[0021] The decontamination basin 14 a receives an endoscope 200 (see FIG. 3) or other medical device therein for decontamination. Any internal channels of the endoscope 200 are connected with flush lines 30 . Each flush line 30 is connected to an outlet of a pump 32 . The pumps 32 are preferably peristaltic pumps or the like that pump fluid, such as liquid and air, through the flush lines 30 and any internal channels of the medical device. Specifically, the pumps 32 either can draw liquid from the basin 14 a through a filtered drain 34 and a first valve S1, or can draw decontaminated air from an air supply system 36 through a valve S2. The air supply system 36 includes a pump 38 and a microbe removal air filter 40 that filters microbes from an incoming air stream. It is preferable that each flush line 30 be provided with a dedicated pump 32 to ensure adequate fluid pressure and to facilitate the individual monitoring of the fluid pressure in each flush line 30 . A pressure switch or sensor 42 is in fluid communication with each flush line 30 for sensing excessive pressure in the flush line. Any excessive pressure sensed is indicative of a partial or complete blockage, e.g., by bodily tissue or dried bodily fluids, in a device channel to which the relevant flush line 30 is connected. The isolation of each flush line 30 relative to the others allows the particular blocked channel to be easily identified and isolated, depending upon which sensor 42 senses excessive pressure.
[0022] The basin 14 a is in fluid communication with a water source 50 such as a utility or tap water connection including hot and cold inlets and a mixing valve 52 flowing into a break tank 56 . A microbe removal filter 54 , such as a 0.2 μm or smaller absolute pore size filter, decontaminates the incoming water which is delivered into the break tank 56 through the air gap to prevent backflow. A pressure type level sensor 59 monitors liquid levels within the basin 14 a . An optional water heater 53 can be provided if an appropriate source of hot water is not available.
[0023] The condition of the filter 54 can be monitored by directly monitoring the flow rate of water therethrough or indirectly by monitoring the basin fill time using a float switch or the like. When the flow rate drops below a select threshold, this indicates a partially clogged filter element that requires replacement.
[0024] A basin drain 62 drains liquid from the basin 14 a through an enlarged helical tube 64 into which elongated portions of the endoscope 200 can be inserted. The drain 62 is in fluid communication with a recirculation pump 70 and a drain pump 72 . The recirculation pump 70 recirculates liquid from the basin drain 62 to a spray nozzle assembly 60 which sprays the liquid into the basin 14 a and onto the endoscope 200 . Coarse and fine screens 71 and 73 , respectively, filter out particles in the recirculating fluid. The drain pump 72 pumps liquid from the basin drain 62 to a utility drain 74 . A level sensor 76 monitors the flow of liquid from the pump 72 to the utility drain 74 . The pumps 70 and 72 can be simultaneously operated such that liquid is sprayed into the basin 14 a while it is being drained to encourage the flow of residue out of the basin and off of the device. Of course, a single pump and a valve assembly could replace the dual pumps 70 , 72 .
[0025] An inline heater 80 , with temperature sensors 82 , downstream of the recirculation pump 70 heats the liquid to optimum temperatures for cleaning and disinfection. A pressure switch or sensor 84 measures pressure downstream of the circulation pump 70 .
[0026] Detergent solution 86 is metered into the flow upstream of the circulation pump 70 via a metering pump 88 . A float switch 90 indicates the level of detergent available. Typically, only a small amount of disinfectant 92 is required. To more accurately meter this, a dispensing pump 94 fills a pre-chamber 96 under control of a hi/low level switch 98 and of course the control system 20 . A metering pump 100 meters a precise quantity of disinfectant as needed.
[0027] Endoscopes and other reusable medical devices often include a flexible outer housing or sheath surrounding the individual tubular members and the like that form the interior channels and other parts of the device. This housing defines a closed interior space, which is isolated from patient tissues and fluids during medical procedures. It is important that the sheath be maintained intact, without cuts or other holes that would allow contamination of the interior space beneath the sheath. Therefore, the decontamination apparatus includes means for testing the integrity of such as sheath.
[0028] An air pump, either the pump 38 or another pump 110 , pressurizes the interior space defined by the sheath of the device through a conduit 112 and a valve S5. Preferably, a HEPA or other microbe-removing filter 113 removes microbes from the pressurizing air. An overpressure switch 114 prevents accidental over pressurization of the sheath. Upon full pressurization, the valve S5 is closed and a pressure sensor 116 looks for a drop in pressure in the conduit 112 which would indicate the escape of air through the sheath. A valve S 6 selectively vents the conduit 112 and the sheath through an optional filter 118 when the testing procedure is complete. An air buffer 120 smoothes out pulsation of pressure from the air pump 110 .
[0029] Preferably, each station 10 and 12 each contain a drip basin 130 and spill sensor 132 to alert the operator to potential leaks.
[0030] An alcohol supply 134 controlled by a valve S3 can supply alcohol to the channel pumps 32 after rinsing steps to assist in removing water from the endoscope channels.
[0031] Flow rates in the supply lines 30 can be monitored via the channel pumps 32 and the pressure sensors 42 . The channels pumps 32 are peristaltic pumps which supply a constant flow. If one of the pressure sensors 42 detects too high a pressure the associated pump 32 cycles off. The flow rate of the pump 32 and its percentage on time provide a reasonable indication of the flow rate in an associated line 30 . These flow rates are monitored during the process to check for blockages in any of the endoscope channels. Alternatively, the decay in the pressure from the time the pump 32 cycles off can also be used to estimate the flow rate, with faster decay rates being associated with higher flow rates.
[0032] A more accurate measurement of flow rate in an individual channel may be desirable to detect more subtle blockages. A metering tube 136 having a plurality of level indicating sensors 138 fluidly connects to the inputs of the channel pumps 32 . One preferred sensor arrangement provides a reference connection at a low point in the metering tube and a plurality of sensors 138 arranged vertically thereabove. By passing a current from the reference point through the fluid to the sensors 138 it can be determined which sensors 138 are immersed and therefore determine the level within the metering tube 136 . Other level sensing techniques can be applied here. By shutting valve S1 and opening a vent valve S7 the channel pumps 32 draw exclusively from the metering tube. The amount of fluid being drawn can be very accurately determined based upon the sensors 138 . By running each channel pump in isolation the flow therethrough can be accurately determined based upon the time and the volume of fluid emptied from the metering tube.
[0033] In addition to the input and output devices described above, all of the electrical and electromechanical devices shown are operatively connected to and controlled by the control system 20 . Specifically, and without limitation, the switches and sensors 42 , 59 , 76 , 84 , 90 , 98 , 114 , 116 , 132 and 136 provide input I to the microcontroller 28 which controls the decontamination and other machine operations in accordance therewith. For example, the microcontroller 28 includes outputs O that are operatively connected to the pumps 32 , 38 , 70 , 72 , 88 , 94 , 100 , 110 , the valves S1-S7, and the heater 80 to control these devices for effective decontamination and other operations.
[0034] Turning also to FIG. 3, an endoscope 200 has a head part 202 , in which openings 204 and 206 are formed, and in which, during normal use of the endoscope 200 , an air/water valve and a suction valve are arranged. A flexible insertion tube 208 is attached to the head part 202 , in which tube a combined air/water channel 210 and a combined suction/biopsy channel 212 are accommodated.
[0035] A separate air channel 213 and water channel 214 , which at the location of a joining point 216 merge into the air/water channel 210 , are arranged in the head part 202 . Furthermore, a separate suction channel 217 and biopsy channel 218 , which at the location of the joining point 220 merge into the suction/biopsy channel 212 , are accommodated in the head part 202 .
[0036] In the head part 202 , the air channel 213 and the water channel 214 open into the opening 204 for the air/water valve. The suction channel 217 opens into the opening 206 for the suction valve. Furthermore, a flexible feed hose 222 connects to the head part 202 and accommodates channels 213 ′, 214 ′ and 217 ′ which via the openings 204 and 206 , are connected to the air channel 213 , the water channel 214 and the suction channel 217 , respectively. In practice, the feed hose 222 is also referred to as the light-conductor casing.
[0037] The mutually connecting channels 213 and 213 ′, 214 and 214 ′, 217 and 217 ′ will be referred to below overall as the air channel 213 , the water channel 214 and the suction channel 217 .
[0038] A connection 226 for the air channel 213 , connections 228 and 228 a for the water channel 214 and a connection 230 for the suction channel 217 are arranged on the end section 224 (also referred to as the light conductor connector) of the flexible hose 222 . When the connection 226 is in use, connection 228 a is closed off. A connection 232 for the biopsy channel 218 is arranged on the head part 202 .
[0039] A channel separator 240 is shown inserted into the openings 204 and 206 . It comprises a body 242 , and plug members 244 and 246 which occlude respectively openings 204 and 206 . A coaxial insert 248 on the plug member 244 extends inwardly of the opening 204 and terminates in an annular flange 250 which occludes a portion of the opening 204 to separate channel 213 from channel 214 . By connecting the lines 30 to the openings 226 , 228 , 228 a , 230 and 232 , liquid for cleaning and disinfection can be flowed through the endoscope channels 213 , 214 , 217 and 218 and out of a distal tip 252 of the endoscope 200 via channels 210 and 212 . The channel separator 240 ensures the such liquid flows all the way through the endoscope 200 without leaking out of openings 204 and 206 and isolates channels 213 and 214 from each other so that each has its own independent flow path. One of skill in the art will appreciate that various endoscopes having differing arrangements of channels and openings will likely require modifications in the channel separator 240 to accommodate such differences while occluding ports in the head 202 and keeping channels separated from each other so that each channel can be flushed independently of the other channels. Otherwise a blockage in one channel might merely redirect flow to a connected unblocked channel.
[0040] A leakage port 254 on the end section 224 leads into an interior portion 256 of the endoscope 200 and is used to check for the physical integrity thereof, namely to ensure that no leakage has formed between any of the channels and the interior 256 or from the exterior to the interior 256 .
[0041] The cleaning and sterilization cycle in detail comprises the following steps.
[0042] Step 1. Open the Lid
[0043] Pressing a foot pedal (not shown) opens the basin lid 16 a . There is a separate foot pedal for each side. If pressure is removed from the foot pedal, the lid motion stops.
[0044] Step 2. Position and Connect the Endoscope
[0045] The insertion tube 208 of the endoscope 200 is inserted into the helical circulation tube 64 . The end section 224 and head section 202 of the endoscope 200 are situated within the basin 14 a , with the feed hose 222 coiled within the basin 14 a with as wide a diameter as possible.
[0046] The flush lines 30 , preferably color-coded, are attached, one apiece, to the endoscope openings 226 , 228 , 228 a , 230 and 232 . The air line 112 is also connected to the connector 254 . A guide located on the on the station 10 provides a reference for the color-coded connections.
[0047] Step 3. Identify the User, Endoscope, and Specialist to the System
[0048] Depending on the customer-selectable configuration, the control system 20 may prompt for user code, patient ID, endoscope code, and/or specialist code. This information may be entered manually (through the touch screen) or automatically such as by using an attached barcode wand (not shown).
[0049] Step 4. Close the Basin Lid
[0050] Closing the lid 16 a preferably requires the user to press a hardware button and a touch-screen 22 button simultaneously (not shown) to provides a fail-safe mechanism for preventing the user's hands from being caught or pinched by the closing basin lid 16 a . If either the hardware button or software button is released while the lid 16 a is in the process of closing the motion stops.
[0051] Step 5. Start Program
[0052] The user presses a touch-screen 22 button to begin the washing/disinfection process.
[0053] Step 6. Pressurize the Endoscope Body and Measure the Leak Rate
[0054] The air pump is started and pressure within the endoscope body is monitored. When pressure reaches 250 mbar, the pump is stopped, and the pressure is allowed to stabilize for 6 seconds. If pressure has not reached 250 mbar in 45 seconds the program is stopped and the user is notified of the leak. If pressure drops to less than 100 mbar during the 6-second stabilization period, the program is stopped and the user is notified of the condition.
[0055] Once the pressure has stabilized, the pressure drop is monitored over the course of 60 seconds. If pressure drops more than 10 mbar within 60 seconds, the program is stopped and the user is notified of the condition. If the pressure drop is less than 10 mbar in 60 seconds, the system continues with the next step. A slight positive pressure is held within the endoscope body during the rest of the process to prevent fluids from leaking in.
[0056] Step 7. Check Connections
[0057] A second leak test checks the adequacy of connection to the various ports 226 , 228 , 228 a , 230 , 232 and the proper placement of the channel separator 240 . A quantity of water is admitted to the basin 14 a so as to submerge the distal end of the endoscope in the helical tube 64 . Valve S 1 is closed and valve S 7 opened and the pumps 32 are run in reverse to draw a vacuum and to ultimately draw liquid into the endoscope channels 210 and 212 . The pressure sensors 42 are monitored to make sure that the pressure in any one channel does not drop by more than a predetermined amount in a given time frame. If it does, it likely indicates that one of the connections was not made correctly and air is leaking into the channel. In any event, in the presence of an unacceptable pressure drop the control system 20 will cancel the cycle an indicate a likely faulty connection, preferably with an indication of which channel failed.
[0058] Pre-Rinse
[0059] The purpose of this step is to flush water through the channels to remove waste material prior to washing and disinfecting the endoscope 200 .
[0060] Step 8. Fill Basin
[0061] The basin 14 a is filled with filtered water and the water level is detected by the pressure sensor 59 below the basin 14 a.
[0062] Step 9. Pump Water through Channels
[0063] The water is pumped via the pumps 32 through the interior of the channels 213 , 214 , 217 , 218 , 210 and 212 directly to the drain 74 . This water is not recirculated around the exterior surfaces of the endoscope 200 during this stage.
[0064] Step 10. Drain
[0065] As the water is being pumped through the channels, the drain pump 72 is activated to ensure that the basin 14 a is also emptied. The drain pump 72 will be turned off when the drain switch 76 detects that the drain process is complete.
[0066] Step 11. Blow Air through Channels
[0067] During the drain process sterile air is blown via the air pump 38 through all endoscope channels simultaneously to minimize potential carryover.
[0068] Wash
[0069] Step 12. Fill Basin
[0070] The basin 14 a is filled with warm water (35° C.). Water temperature is controlled by controlling the mix of heated and unheated water. The water level is detected by the pressure sensor 59 .
[0071] Step 13. Add Detergent
[0072] The system adds enzymatic detergent to the water circulating in the system by means of the peristaltic metering pump 88 . The volume is controlled by controlling the delivery time, pump speed, and inner diameter of the peristaltic pump tubing.
[0073] Step 14. Circulate Wash Solution
[0074] The detergent solution is actively pumped throughout the internal channels and over the surface of the endoscope 200 for a predetermined time period, typically of from one to five minutes, preferably about three minutes, by the channel pumps 32 and the external circulation pump 70 . The inline heater 80 keeps the temperature at about 35° C.
[0075] Step 15. Start Block Test
[0076] After the detergent solution has been circulating for a couple of minutes, the flow rate through the channels is measured. If the flow rate through any channel is less than a predetermined rate for that channel, the channel is identified as blocked, the program is stopped, and the user is notified of the condition. The peristaltic pumps 32 are run at their predetermined flow rates and cycle off in the presence of unacceptably high pressure readings at the associated pressure sensor 42 . If a channel is blocked the predetermined flow rate will trigger the pressure sensor 42 indicating the inability to adequately pass this flow rate. As the pumps 32 are peristaltic, their operating flow rate combined with the percentage of time they are cycled off due to pressure will provide the actual flow rate. The flow rate can also be estimated based upon the decay of the pressure from the time the pump 32 cycles off.
[0077] Step 16. Drain
[0078] The drain pump 72 is activated to remove the detergent solution from the basin 14 a and the channels. The drain pump 72 turns off when the drain level sensor 76 indicates that drainage is complete.
[0079] Step 17.
[0080] Blow Air
[0081] During the drain process sterile air is blown through all endoscope channels simultaneously to minimize potential carryover.
[0082] Rinse
[0083] Step 18. Fill Basin
[0084] The basin 14 a is filled with warm water (35° C.). Water temperature is controlled by controlling the mix of heated and unheated water. The water level is detected by the pressure sensor 59 .
[0085] Step 19. Rinse
[0086] The rinse water is circulated within the endoscope channels (via the channel pumps 32 ) and over the exterior of the endoscope 200 (via the circulation pump 70 and the sprinkler arm 60 ) for 1 minute.
[0087] Step 20. Continue Block Test
[0088] As rinse water is pumped through the channels, the flow rate through the channels is measured and if it falls below the predetermined rate for any given channel, the channel is identified as blocked, the program is stopped, and the user is notified of the condition.
[0089] Step 21. Drain
[0090] The drain pump is activated to remove the rinse water from the basin and the channels.
[0091] Step 22.
[0092] Blow Air
[0093] During the drain process sterile air is blown through all endoscope channels simultaneously to minimize potential carryover.
[0094] Step 23. Repeat Rinse
[0095] Steps 18 through 22 are repeated to ensure maximum rinsing of enzymatic detergent solution from the surfaces of the endoscope and the basin.
[0096] Disinfect
[0097] Step 24. Fill Basin
[0098] The basin 14 a is filled with very warm water (53° C.). Water temperature is controlled by controlling the mix of heated and unheated water. The water level is detected by the pressure sensor 59 . During the filling process, the channel pumps 32 are off in order to ensure that the disinfectant in the basin is at the in-use concentration prior to circulating through the channels.
[0099] Step 25. Add Disinfectant
[0100] A measured volume of disinfectant 92 , preferably CIDEX OPA orthophalaldehyde concentrate solution, available from Advanced Sterilization Products division Ethicon, Inc., Irvine, Calif., is drawn from the disinfectant metering tube 96 and delivered into the water in the basin 14 a via the metering pump 100 . The disinfectant volume is controlled by the positioning of the fill sensor 98 relative to the bottom of the dispensing tube. The metering tube 96 is filled until the upper level switch detects liquid. Disinfectant 92 is drawn from the metering tube 96 until the level of the disinfectant in the metering tube is just below the tip of the dispensing tube. After the necessary volume is dispensed, the metering tube 96 is refilled from the bottle of disinfectant 92 . Disinfectant is not added until the basin is filled, so that in case of a water supply problem, concentrated disinfectant is not left on the endoscope with no water to rinse it. While the disinfectant is being added, the channel pumps 32 are off in order to insure that the disinfectant in the basin is at the in-use concentration prior to circulating through the channels.
[0101] Step 26. Disinfect
[0102] The in-use disinfectant solution is actively pumped throughout the internal channels and over the surface of the endoscope, ideally for a minimum of 5 minutes, by the channel pumps and the external circulation pump. The temperature is controlled by the in-line heater 80 to about 52.5° C.
[0103] Step 27. Flow Check
[0104] During the disinfection process, flow through each endoscope channel is verified by timing the delivering a measured quantity of solution through the channel. Valve S1 is shut, and valve S 7 = opened, and in turn each channel pump 32 delivers a predetermined volume to its associated channel from the metering tube 136 . This volume and the time it takes to deliver provides a very accurate flow rate through the channel. Anomalies in the flow rate from what is expected for a channel of that diameter and length are flagged by the control system 20 and the process stopped.
[0105] Step 28. Continue Block Test
[0106] As disinfectant in-use solution is pumped through the channels, the flow rate through the channels is also measured as in Step 15 .
[0107] Step 29. Drain
[0108] The drain pump 72 is activated to remove the disinfectant solution from the basin and the channels.
[0109] Step 30. Blow Air
[0110] During the drain process sterile air is blown through all endoscope channels simultaneously to minimize potential carryover.
[0111] Final Rinse
[0112] Step 31. Fill Basin
[0113] The basin is filled with sterile warm water (45° C.) that has been passed through a 0.2μ filter.
[0114] Step 32. Rinse
[0115] The rinse water is circulated within the endoscope channels (via the channel pumps 32 ) and over the exterior of the endoscope (via the circulation pump 70 and the sprinkler arm 60 ) for 1 minute.
[0116] Step 33. Continue Block Test
[0117] As rinse water is pumped through the channels, the flow rate through the channels is measured as in Step 15.
[0118] Step 34. Drain
[0119] The drain pump 72 is activated to remove the rinse water from the basin and the channels.
[0120] Step 35. Blow Air
[0121] During the drain process sterile air is blown through all endoscope channels simultaneously to minimize potential carryover.
[0122] Step 36. Repeat Rinse
[0123] Steps 31 through 35 are repeated two more times (a total of 3 post-disinfection rinses) to ensure maximum reduction of disinfectant residuals from the endoscope 200 and surfaces of the reprocessor.
[0124] Final Leak Test
[0125] Step 37. Pressurize the Endoscope Body and Measure Leak Rate
[0126] Repeat Step 6.
[0127] Step 38. Indicate Program Completion
[0128] The successful completion of the program is indicated on the touch screen.
[0129] Step 39. De-Pressurize the Endoscope
[0130] From the time of program completion to the time at which the lid is opened, pressure within the endoscope body is normalized to atmospheric pressure by opening the vent valve S5 for 10 seconds every minute.
[0131] Step 40. Identify the User
[0132] Depending on customer-selected configuration, the system will prevent the lid from being opened until a valid user identification code is entered.
[0133] Step 41. Store Program Information
[0134] Information about the completed program, including the user ID, endoscope ID, specialist ID, and patient ID are stored along with the sensor data obtained throughout the program.
[0135] Step 42. Print Program Record
[0136] If a printer is connected to the system, and if requested by the user, a record of the disinfection program will be printed.
[0137] Step 43. Remove the Endoscope
[0138] Once a valid user identification code has been entered, the lid may be opened (using the foot pedal as in step 1, above). The endoscope is then disconnected from the flush lines 30 and removed from the basin 14 a. The lid can then be closed using both the hardware and software buttons as described in step 4, above.
[0139] The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | A method detects proper connection of fixtures to one or more channels in an endoscope during a cleaning or disinfection procedure. The endoscope has a first opening into one of its channels. The method includes the steps of placing the endoscope at the first opening in a liquid while leaving a gas within the channel, drawing a vacuum on the gas through a second opening into the channel and thereby drawing some of the liquid into the channel, and detecting for air leaking into the channel. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of the co-pending application of the same inventor, titled "Method and Apparatus for Cleaning Fibers", filed May 15, 1989, under Ser. No. 351,384, issued on Dec. 11, 1990, as U.S. Pat. No. 4,976,822.
INFORMATION DISCLOSURE STATEMENT
It is well known in the art to recycle paper fibers by mechanically and chemically processing the paper into a slurry, and treating the slurry to remove ink, clay and other unwanted additives and contaminants. Conventional techniques including mechanical and chemical treatment, centrifuging, flotation, screening and the like will remove the greatest part of the unwanted material from the fibers, but the prior art techniques tend to leave a certain amount of ink and other contaminants on the fibers. As a result, the contaminants are present when the fibers are reused to make paper.
One technique utilized as a final step for removal of fine particles is to wash the fibers by allowing the fibers to collect on a screen, and flowing wash water over the fibers and through the screen. The concept is that the wash water will pick up the contaminants and carry the contaminants away from the fibers. The problem with the technique is that the fibers collect on the screen, and the mass of fibers tends to retain some of the contaminants so that the washing is not entirely effective. A similar technique is disclosed in the patent to Gartland U.S. Pat. No. 4,215,447. The Gartland device includes a screen on which the fibers tend to collect, and wash water is flowed through the fibers and through the screen. The Gartland improvement is in the provision of stirring means which removes clusters of fibers from the screen and causes the clusters to be entrained in a fluid stream moving from an inlet for the pulp to an outlet for the pulp. These clusters of fibers will of course retain ink and other contaminants to prevent complete cleaning of the fibers.
SUMMARY OF THE INVENTION
This invention relates generally to the cleaning of fibrous material, and is more particularly concerned with the removal of ink and other contaminants from fibers used in paper making and the like.
The present invention provides a method wherein a fluid suspension of fibers is cleaned by application of a washing fluid. More specifically, a slurry of fibers in fluid suspension is confined, at least one of the walls of the confinement being a screen. Fluidizing means assure that the fibers remain in a fluid state as a washing liquid is passed over the fibers to remove the undesirable contaminants. By proper selection of screens and adjustment of the pressure differential across the fluidized fiber, the undesirable contaminants can be removed without undue loss of fibers.
The apparatus of the present invention includes a first channel for passage of the fluidized fibers, the first channel having at least one wall made up of a screen. A second channel carries washing fluid, the second channel being arranged so that the washing fluid can pass through the screen to the first channel for cleaning the fiber and pass back to the second channel for discharge of the contaminants with the washing fluid.
In the preferred embodiment of the invention, the first channel includes screens on two opposed sides of the channel, and fluidizing means movable within the first channel. The first channel has second channel means contiguously disposed at the two screens, the arrangement being such that washing fluid can be directed along each screen and can be directed from one second channel means, through the first channel, and to another second channel means. The particular flow of the washing fluid is dependent on the pressure differentials used.
The present invention therefore provides a method and apparatus for cleaning fiber wherein the fiber remains in a fluidized state. In this fluidized state, a washing fluid is passed through the fibers to remove the unwanted contaminants from the fibers. The size of the screen, in conjunction with the pressure differential across the screen, will determine the maximum particle size that will be removed, and can be used for fractionating the fibers.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will become apparent from consideration of the following specification when taken in conjunction with the accompanying drawings in which:
FIG. 1 is an elevational view of a cleaning apparatus made in accordance with the present invention, the front of the passageway being removed to reveal the construction thereof;
FIG. 2 is an enlarged, fragmentary view showing the screen and fluidizing means in the device of FIG. 1;
FIG. 3 is a transverse cross-sectional view through a modified form of apparatus made in accordance with the present invention; and,
FIG. 4 is an enlarged, fragmentary view showing the screen and fluidizing means in the device of FIG. 3.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring now more particularly to the drawings, and to those embodiments of the invention here presented by way of illustration, FIG. 1 includes a central passageway 10 through which the slurry containing the fibers will pass. An inlet 11 allows entry of the slurry, and the cleaned material is discharged from the outlet 12. Those skilled in the art will understand that appropriate pumps or the like shown schematically at 13 will cause the slurry to move. Such apparatus is well known to those skilled in the art and no further showing is thought to be required.
On each side of the passageway 10 there are wash water channels 14 and 15. It will be noted that the channel 14 includes inlets/outlets 16 and 18, and channel 15 includes inlets/outlets 19 and 20. Each of the inlets/outlets 16-20 may be either an inlet or an outlet, or the wash water may be reversed periodically so the various inlets/outlets have different functions at different times. Pumps 17 and 23 are shown for moving the wash water through the channels 14 and 15. This will be discussed in more detail hereinafter.
The wall 21 between the channel 14 and the passageway 10 comprises a screen; and, the wall 22 between the passageway 10 and the channel 15 also comprises a screen. As a result, it will be understood that the wash water from the channels 14 and 15 can pass through the walls 21 and 22 and wash the fibers in the slurry flowing through the passageway 10.
An important feature of the present invention is the maintaining of the fibers in a fluidized state as the slurry flows through the passageway 10. More particularly, the individual fibers are not allowed to agglomerate or to collect on the screen 21 or 22. Anytime the fibers agglomerate, or collect together, it becomes difficult to bathe each fiber sufficiently in wash water and remove all contaminants from the fiber. Thus, the device in FIG. 1 includes fluidizing means generally designated at 24, the fluidizing means 24 including side plates 25 and a plurality of agitators 26. Agitators 26 are made of some impermeable material and are spaced throughout the length of the fluidizing means 24, the fluidizing means 24 in turn extending substantially the full distance of the passageway 10. Between the agitators 26, the fluidizing means 24 is open to the screens 21 and 22 so fluid can pass from within the fluidizing means 24 through the screens 21 and 22 and then to the channels 14 and 15.
At the upper end of the fluidizing means 24, it will be seen that there is a shaft 28, the shaft 28 comprising a means for causing vertical reciprocation of the fluidizing means 24. A conventional mechanism can be utilized to move the shaft 28 back and forth and cause the appropriate motion of the fluidizing means 24. A seal 27 prevents leakage around the shaft 28.
With the above description in mind, it should now be understood that a slurry including fibers to be cleaned will be admitted to the passageway 10 at the entrance 11. Appropriate pump pressure from the pump 13 will be applied to move the slurry from the entrance 11 to the discharge opening 12. As the slurry moves through the passageway 10, the fluidizing means 24 will be moved reciprocally and the plurality of agitators 26 will cause rather severe motion in the fluid to prevent fibers from agglomerating, and to prevent fibers from sticking to either of the screens 21 or 22. Meanwhile, wash water will be passed under pressure provided by pumps 17 and/or 23 through the channels 14 and 15. Arrangement of the apparatus is such that wash water can be directed as desired for the best cleaning. By way of example, wash water may be introduced at the inlet 16 at one end of the channel 14. The wash water may then be removed at the exit 20 of the channel 15. This arrangement will provide a counter flow of the two fluids, for the maximum cleaning ability. The process can be reversed, or two separate streams of wash water can be established, one in the channel 14 and one in the channel 15. It will be understood that the object of the invention is to cause the wash water to engage the slurry in the passageway 10 to pick up the various contaminants from the fibers, and to remove the contaminants in the slurry.
Looking now at FIG. 2 of the drawings, the construction is shown in more detail. The channel 14 is shown as having an outer wall 29, and the inner wall 21 which is a perforate screen. The agitators 26 are shown as angled devices extending into the passageway 10. Thus, as the fluidizing means 24 is moved reciprocally, the agitators 26 will move reciprocally. Agitators 26 are very close to the screen 21, so the agitators 26 will prevent accumulation on the screen somewhat by mechanically removing any fibers that are attached to the screen. More importantly, the motion of the agitators 26 will cause severe turbulence in the fluid within the passageway 10. This turbulence will be sufficient to maintain the fibers in a separated state, and also sufficient to prevent fibers from sticking to the screen 21.
It will be understood by those skilled in the art that used paper will generally be processed into a liquid, primarily by mechanical and chemical means, and some contaminants may be removed through prior processing. It is common to use sedimentation, centrifuging, and preliminary screening to remove some of the contaminants; and, flotation is commonly used for substantial cleaning of the fibers. Any of these conventional steps may be carried out initially, before the fiber is introduced to the apparatus shown in FIG. 1 of the drawings. As is stated above, the prior art techniques do not yield sufficiently clean fiber and something further is needed. The present invention can therefore be used as the final cleaning step, though of course some prior art steps may be omitted, and the apparatus and method of the present invention substituted therefor.
Attention is next directed to FIG. 3 of the drawings which shows a modified form of apparatus made in accordance with the present invention. The cleaning technique is the same as that discussed in connection with FIGS. 1 and 2, but the configuration of the apparatus is somewhat different.
In FIG. 3, there is a cylindrical container 30 having impermeable walls, and an inlet 31. At one end of the cylindrical container 30 there is an outlet designated at 32. Mounted within the container 30, and concentric therewith, there are two screens designated at 34 and 35. The screen 34 is stationarily mounted, and is provided with an inlet 36 and an outlet 38. While the inlet and outlet 36 and 38 are adjacent to each other, a wall 39 separates them for proper flow control.
Considering the description of the prior embodiment, it should be understood that a slurry or the like containing the fibers to be cleaned will be admitted through the inlet 36 so the fibers are contained in the passageway 40, between the two screens 34 and 35. A pump such as the pump 37 will cause the slurry to move around the passageway 40 and to be discharged at the discharge 38. However, while the slurry is moving around the passageway 40, wash water will be admitted through the inlet 31 to fill the channel 41. Appropriate pump pressure from the pump 33 will cause the wash water to move from the channel 41, through the screens 34 and 35 and to the center channel of the device to be discharged through the opening 32. As before, those skilled in the art will understand that the inlet and exit 36 and 38 are reversible, as are the inlet and exit 31 and 32. The flow can be periodically reversed or can be run in either direction as desired. Also, the inlet 31 may be located on an end of the apparatus, opposite the exit 32. The inlet and outlet 36 and 38 may also be located on the ends of the device, communicating with the passageway 40 between the screens 34 and 35.
If the inlet and outlet are located at the ends of the device, those skilled in the art will understand that the screen 34 can then be made to rotate, preferably counter to the rotation of the screen 35, for better agitation.
FIG. 4 is an enlarged section of the screens 34 and 35 and it will be seen that each of the screens includes a plurality of agitators 42. The agitators 42 are here shown as being angled members similar to the agitators 26, the agitators 42 being integrally formed with the screens 34 and 35; but, it will be understood that additional pieces can be attached to an existing screen if desired.
It will therefore be understood that the operation of the apparatus shown in FIGS. 3 and 4 is substantially the same as the operation of the device shown in FIGS. 1 and 2. The screen 35 will be substantially constantly rotated while the apparatus is in use. Rotation of the screen 35 will cause relative motion between the agitators 42 so the slurry in the passageway 40 will be in a highly turbulent flow. As is mentioned above, the turbulence will be sufficient to prevent fibers from collecting on either screen, and will be sufficient to prevent the agglomeration of fibers in the fluid stream. As a result, the wash water passing through the channel 41 and through the screens 34 and 35 will clean the fibers and carry the unwanted contaminants from the passageway 40, through the screen 34 or 35 and into the discharge 32.
It will also be understood by those skilled in the art that contaminants to be removed from the fiber must be small enough to pass through the openings in the screen 21, 22, 34, or 35. There is always a compromise in selecting a screen small enough to prevent the loss of fibers but large enough to allow loss of the unwanted contaminants. Utilizing the method and apparatus of the present invention it should further be recognized that the pressure of the wash water is another variable that will allow removal of more or less of the contaminants and more or less of the fibers.
Through the use of extremely high pressure, which is to say a large pressure differential across a screen, some small fibers might be forced through the screen. With a smaller pressure differential, relatively solid particles such as ink or clay might pass through the screen whereas a fiber will not pass through the screen. The present invention therefore provides additional controls, and excellent cleaning of the fibers with minimal loss of the fibers.
It will of course be understood by those skilled in the art that the particular embodiments of the invention here presented are by way of illustration only, and are meant to be in no way restrictive; therefore, numerous changes and modifications may be made, and the full use of equivalents resorted to, without departing from the spirit or scope of the invention as outlined in the appended claims. | The fibers of recycled paper are cleaned by agitating the slurry containing the fibers to maintain the fibers in suspension, and contacting the slurry with wash water to remove ink and other contaminants. The apparatus includes a passageway having screens forming opposite sides of the passageway. Agitators are within the passageway, and create enough turbulence to prevent fibers from settling or agglomerating. Channels adjacent to each screen carry wash water, and pump pressure creates a pressure differential across the screens to cause the wash water to contact the slurry and to be removed from the passageway. | 3 |
TECHNICAL FIELD
The present invention relates to a cable guide for guiding a cable member for conducting a signal and/or power in an articulated joint of a robot or the like.
BACKGROUND OF THE INVENTION
In an industrial robot or the like equipped with a multi-joint arm, an electric motor and sensors provided in each of the articulated joints corresponding to the shoulder, elbow and wrist are required to be fed with power and control signals from a control circuit incorporated in the main body of the robot. The cables for conducting the power to the electric motor and the control signals to the sensors extend along the length of the arm, and are typically given with a slack at each of the articulated joints to accommodate for the flexing movement of the articulated joint.
As methods for passing a cable through an articulated joint, it is known to provide a cable passage that bypasses the bearing portion of the articulated joint (as disclosed in Japanese patent laid open publication No. 63-288692) and to use a hollow shaft in the articulated joint to pass the cable therethrough (as disclosed in Japanese patent laid open publication No. 61-168478).
However, according to the technique disclosed in Japanese patent laid open publication No. 63-288692, because the wiring duct for protecting the cable is provided on the exterior of the articulated joint and there is no difference in that the cable extends along the exterior of the articulated joint, an increase in the external dimensions of the articulated joint cannot be avoided.
However, according to the technique disclosed in Japanese patent laid open publication No. 61-168478, because the cable is passed through the inner bore of the hollow shaft, a length of the cable corresponding to the length of the shaft must be spent at the articulated joint so that the total length of the cable becomes relatively large for the given length of the arm and this prevents a compact design of the articulated joint.
BRIEF SUMMARY OF THE INVENTION
In view of such problems of the prior art, a primary object of the present invention is to provide an improved cable guide for-an articulated joint of a robot or the like that allows a compact design of the articulated joint while minimizing the length of the cable.
To achieve such an object, the present invention provides a cable guide for guiding a cable member ( 27 ) for conducting a signal and/or power in an articulated joint that connects a first link member ( 2 ) and a second link member ( 2 ) to each other in a relatively rotatable manner, comprising: a hollow center drum ( 13 ) including a substantially circular outer peripheral wall ( 16 ) and fixedly attached to the first link member, the outer peripheral wall being provided with a hole ( 28 ) formed at a first angular position substantially aligning with the first link and a slot ( 17 ) formed at a second angular position and elongated circumferentially over an angle substantially corresponding to a range of angular movement of the second link member relative to the first link member in such a manner that the cable member is passed into the center drum from the hole and out of the center drum from the slot.
Preferably, the cable guide further comprises a substantially annular drum holder ( 14 ) coaxially surrounding the center drum and integrally attached to the second link member, the drum holder being provided with a cutout for preventing interference with a part of the cable member extending into the hole of the center drum. Thereby, the cable member can pass through the interior of the articulated joint along the shortest path, and the necessary length of the cable can be minimized.
If the cable guide further comprises a cable support member ( 21 ) integrally attached to the center drum and extending inside the center drum to a point adjacent to a center of a rotational movement between the first link member and second link member, the minimum radius of curvature of the cable member can be favorably controlled. If the center drum is provided with an end wall, the cable support member can be integrally formed with the end wall.
If the cable guide further comprises a shutter plate ( 23 L) slidably guided by the center drum for selectively closing the slot, dust and other foreign matter are prevented from getting into the cable support member, and the interior of the cable support member can be concealed from view.
The shutter plate may be actuated by a part of the cable member when opening the slot and by a part of the second link member when closing the slot.
The cable member may be retained by a part of the center drum at a point adjacent to the hole whereby the flexing of the articulated joint would not cause any unstable movement of the cable member.
The first link member and second link member may be relatively rotatably joined to each other on either side the center drum. Thereby, the center drum is entirely received in the articulated joint so that the articulated joint can be designed in a highly compact manner and the center drum is favorably protected. Also, the center drum is protected from excessive forces.
BRIEF DESCRIPTION OF THE DRAWINGS
Now the present invention is described in the following with reference to the appended drawings, in which:
FIG. 1 is a fragmentary sectional side view of a robot arm embodying the present invention taken along line I-I in FIG. 2 ;
FIG. 2 is a sectional plan view of the articulated joint in a straightened state; and
FIG. 3 is a sectional plan view of the articulated joint in a flexed state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show the outline of the structure of the cable guide for an articulated joint according to the present invention that can be applied to the elbow joint of an arm of an industrial robot or the knee joint of a bipedal robot. The illustrated embodiment is described in the following assuming for the convenience of description that the embodiment is applied to an articulated joint of a revolving arm (first link) which is joined to a fixed arm (second link) so as to be rotatable around a vertical or horizontal axis with respect to the-stationary fixed arm.
The revolving arm 1 is connected to the fixed arm 2 via a knuckle joint 3 in a relatively rotatable manner. The knuckle joint 3 that forms the articulated joint comprises two pairs of extensions 4 a, 4 b, 5 a, 5 b, one pair extending from the revolving arm 1 in a mutually spaced relationship along the rotational axial line and the other pair extending from the fixed arm in a similar manner. The pair of extensions 5 a, 5 b extending from the fixed arm 2 are each fitted with a ball bearing 6 . The pair of extensions 4 a, 4 b extending from the revolving arm 1 are interposed between the pair of extensions 5 a, 5 b extending from the fixed arm 2 . A shaft member 7 is fitted into the inner race of each of the ball bearings 6 fitted to the extensions 5 a, 5 b of the fixed arm 2 , and is fixedly attached to a corresponding one of the extensions 4 a, 4 b of the revolving arm 1 by using threaded bolts B so that the revolving arm 1 is rotatably supported by the fixed arm 2 .
The fixed arm 2 may consist of a tubular member having a rectangular cross section, and an electric motor 8 equipped with a reduction gear is mounted within the fixed arm 2 adjacent to the articulated joint. The output shaft of the electric motor 8 extends out of the fixed arm 2 , and the projecting end thereof is fixedly provided with a cogged drive pulley 9 . The shaft member 7 fixedly attached to the corresponding extension 4 a of the revolving arm 1 is centrally and fixedly provided with a cogged driven pulley 10 , and an endless cogged belt 11 is passed around the two cogged pulleys 9 and 10 . Thereby, by rotating the electric motor 8 fixedly attached to the fixed arm 2 , the shaft members 7 fixedly attached of the extensions 5 a, 5 b of the fixed arm 2 is made to turn, and the revolving arm 1 integrally connected to the extensions 4 a, 4 b is made to rotate in a horizontal plane. The reduction gear may be provided on the side of the knuckle joint 3 depending on the need of the design.
Between the extensions 4 a, 4 b of the revolving arm 1 is interposed a cable guide 12 which includes a center drum 13 and a drum holder 14 that are disposed so as to be rotatable relative to each other.
The center drum 13 consists of a drum-shaped member having a relatively small axial dimension and closed at the both axial ends and substantially around the periphery, and is provided with a funnel-like extension tube 15 extending from a part of the circumferential wall of the center drum 13 and having an axial line extending in a tangential direction. An opposite side of the circumferential wall 16 of the center drum 13 is formed with a slot 17 extending over an angular range (of about half a circumference in the case of the illustrated embodiment) corresponding to the moveable angle between the revolving arm 1 and fixed arm 2 .
The inner surface of each of the axial end walls 18 of the center drum 13 is provided with a rib 20 that defines a circumferential groove 19 in cooperation with the outer circumferential wall 16 . The circumferential groove 19 and rib 20 extending substantially over the entire circumference except for the part adjacent to the root portion of the extension tube 15 . One end of the rib 20 connects to a snail-like portion 21 formed as a spiral rib extending from the inner surface of the outer peripheral wall 16 toward the center, and the corresponding end of the circumferential groove 19 connects to a guide groove 22 formed as a recess in the snail-like portion 21 .
The circumferential groove 19 slidably receives a long shutter plate 23 L and a short shutter plate 23 S which extend from a middle part of the slot 17 in the two opposite directions. The shutter plates 23 L, 23 S are curved along the circumferential groove 19 . In particular, the long shutter plate 23 L is made of thin plastic plate which is flexible enough to freely slide into the guide groove 22 having a smaller radius of curvature than the circumferential groove 19 .
The outer peripheral part of each axial end wall 18 of the center drum 13 is provided with an annular shoulder 24 which is reduced in diameter from the outer circumferential wall 16 . This annular shoulder 24 is engaged the central part of the drum holder 14 over an angular range of more than half the entire circumference so that the center drum 13 can rotate around a certain point by being retained by the drum holder 14 .
The drum holder 14 is engaged by engagement pieces 25 a, 25 b formed at an end of the revolving arm 1 adjacent to the knuckle joint and is thereby integrally joined to the revolving arm 1 . The drum holder 14 is provided with a clearance groove 26 in an axially middle part thereof over an angular range of about half the entire circumference to stay clear from the extension tube 15 of the center drum 13 .
A cable 27 is drawn from the fixed arm 2 into the center drum 13 . The cable 27 is passed into a circular opening 28 of the extension tube 15 that faces the fixed arm 2 , and extends along the outer circumferential surface of the snail-like portion 21 in the center drum 13 . The cable 27 further extends through a gap defined between the ends 30 , 31 of the two shutter plates 23 L, 23 S opposing each other in the middle part of the slot 17 , and then into the revolving arm 1 , which consists of a tubular member having a rectangular cross section similarly as the fixed arm 2 .
When the knuckle joint 3 is flexed in the direction indicated by arrow A in FIG. 2 by actuating the electric motor 8 , the cable 27 is allowed to curve by being guided by the outer circumferential surface of the snail-like portion 27 . Because the part of the cable 27 that has been introduced into the circular opening 28 of the extension tube 15 is substantially immobile in a same way as the fixed arm 2 , the center drum 13 which is engaged by the part of the cable 27 extending in the fixed arm 2 by way of the circular opening 28 of the extension tube 15 is therefore integral with the fixed arm 2 , and remains immobile at all times. On the other hand, the drum holder 14 that is engaged by the revolving arm 1 rotates integrally with the revolving arm 1 .
The part of the cable 27 extending in the revolving arm 1 is secured to appropriate parts of the revolving arm 1 , for instance by using saddle members so as to maintain a fixed relationship to the revolving arm 1 . Therefore, as the revolving arm 1 rotates, the cable 27 therein moves in the direction indicated by arrow A in FIG. 2 , and at the same time pushes the end portion 31 of the long shutter plate 23 L. As a result, the long shutter plate 23 L moves into the guide groove 22 formed in the snail-like portion 21 in continuation with the circumferential groove 19 , and progressively opens the surface of the slot 17 opposing the end portion of the revolving arm 1 . At this time, the short shutter plate 23 S on the opposite side maintains a fixed relationship with the circumferential groove 19 until the flexing angle reaches a certain value.
In this manner, the cable 27 can freely bend over the angular range defined by the slot 17 formed in the outer circumferential wall 16 of the center drum 13 . Owing to the clearance groove 26 formed in the axially middle part of the drum holder 14 , the extension tube 15 would not interfere with the rotational movement of the drum holder 14 .
When the revolving arm 1 has rotated by about 90 degrees, a large part of the clearance groove 26 of the drum holder 14 is received in the space defined between the two extensions 5 a, 5 b of the fixed arm 2 so that only the outer circumferential wall 16 of the center drum 13 is visible from the exterior of the knuckle joint 3 (in the direction indicated by arrow C in FIG. 3 ). The part of the cable 27 extending inside the center drum 13 curves along-the outer circumferential surface of the snail-like portion 21 , and the minimum radius of curvature is determined by the curvature of radius of the snail-like portion 21 so that the cable 27 is prevented from being bent at an undesirably sharp angle. Furthermore, because the long shutter plate 23 L is inside the guide groove 22 of the snail-like portion 21 , the long shutter plate 23 L would not interfere with the cable 27 drawn into the center drum 13 .
When the revolving arm 1 is flexed even further from the state illustrated in FIG. 3 , one of the circumferential walls 29 of the clearance groove 26 engages the corresponding end portion 30 of the short shutter plate 23 S and closes the slot 17 so that the interior of the center drum 13 is prevented from becoming visible between the clearance grooves 26 from the direction indicated by arrow C in FIG. 3 .
When the revolving arm 1 is straightened, one of the engagement pieces 25 a of the revolving arm 1 engaging the drum holder 14 pushes the end portion 31 of the long shutter plate 23 L and closes the slot 17 . When the knuckle joint 3 is straightened, the slot 17 is completely closed by the long shutter plate 23 L. Thereby, dust and other foreign matter are prevented from getting into the center drum 13 , and the interior of the center drum 13 is prevented from becoming visible between the clearance grooves 26 from the direction indicated by arrow B in FIG. 2 .
The cable guide of the present invention described above is equally applicable to other articulated joints such as shoulders and wrists. The relationship between the revolving arm 1 and fixed arm 2 is only relative, and the present invention can also be implemented in a reversed relationship. As for the relationship between each arm 1 , 2 and cable 27 , as long as one of the arms and cable move in a substantially integral manner, it is possible to allow a relative rotation between the center drum 13 and drum holder 14 without any problem. The present invention is applicable not only to guide electric cables as described above but also to guide flexible tubes for supplying hydraulic and pneumatic media.
INDUSTRIAL APPLICABILITY
As can be appreciated from the foregoing description, according to the present invention, the dimensions of the part of an articulated joint for passing a cable can be minimized, and the weight of the robot can be reduced while the loss of power transmission can be reduced at the same time. Furthermore, because the cable is favorably concealed, not only the external appearance can be enhanced but also the cable is protected from damages. In particular, because the curvature of the cable at the time of flexing the articulated joint is controlled, the damage to the cable due to repeated bending can be minimized, and the reliability of the robot can be improved. Furthermore, because the relative rotation between the center drum and drum holder is effected without causing any excessive bending of the cable, the need for a powered actuator is eliminated while the structure is simplified at the same time.
Although the present invention has been described in terms of a preferred embodiment thereof, it is obvious to a person skilled in the art that various alterations and modifications are possible without departing from the scope of the present invention which is set forth in the appended claims. | To provide an improved cable guide for an articulated joint of a robot or the like that allows a compact design of the articulated joint while minimizing the length of the cable, a substantially circular outer peripheral wall ( 16 ) of a hollow center drum ( 13 ) fixedly attached to the first link member is formed with a hole ( 28 ) at a first angular position substantially aligning with the first link and a slot ( 17 ) formed at a second angular position and elongated circumferentially over an angle substantially corresponding to a range of angular movement of the second link member relative to the first link member in such a manner that the cable member is passed into the center drum from the hole and out of the center drum from the slot. Thereby, the cable member can pass through the interior of the articulated joint along the shortest path, and the necessary length of the cable can be minimized. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Nonprovisional application Ser. No. 09/833,016 filed Apr. 10, 2001, and therethrough from U.S. Nonprovisional application Ser. No. 09/387,737 filed Aug. 31, 1999 and now issued as U.S. Pat. No. 6,213,225, and therethrough from provisional 60/098,466 filed Aug. 31, 1998.
[0002] This application also claims priority from provisional 60/474,671 filed May 30, 2003.
[0003] This application also claims priority from provisional 60/474,672 filed May 30, 2003.
[0004] This application also claims priority from U.S. Nonprovisional application Ser. No. 10/189,305 filed Jul. 2, 2002, therethrough from U.S. Nonprovisional application Ser. No. 09/629,344 filed Aug. 1, 2000 and now issued as U.S. Pat. No. 6,412,577, and therethrough from U.S. Nonprovisional application Ser. No. 09/387,304 filed Aug. 31, 1999 and now issued as U.S. Pat. No. 6,095,262, and therethrough from provisional 60/098,442 filed Aug. 31, 1998.
FIELD OF THE INVENTION
[0005] The present invention relates generally to the drilling of oil and gas wells, or similar drilling operations, and in particular to orientation of tooth angles on a roller cone drill bit.
BACKGROUND AND SUMMARY OF THE INVENTION
[0006] Background: Rotary Drilling
[0007] Oil wells and gas wells are drilled by a process of rotary drilling, using a drill rig such as is shown in FIG. 10. In conventional vertical drilling, a drill bit 10 is mounted on the end of a drill string 12 (drill pipe plus drill collars), which may be more than a mile long, while at the surface a rotary drive (not shown) turns the drill string, including the bit at the bottom of the hole.
[0008] Two main types of drill bits are in use. One being the roller cone bit; an example of which is seen in FIG. 11. In this bit, a set of cones 16 (two are visible) having teeth or cutting inserts 18 are arranged on rugged bearings on the arms of the bit. As the drill string is rotated, the cones will roll on the bottom of the hole, and the teeth or cutting inserts will crush the formation beneath them. (The broken fragments of rock are swept uphole by the flow of drilling fluid.) The second type of drill bit is a drag bit, having no moving parts, seen in FIG. 12.
[0009] Drag bits are becoming increasingly popular for drilling soft and medium formations, but roller cone bits are still very popular, especially for drilling medium and medium-hard rock. There are various types of roller cone bits: insert-type bits, which are normally used for drilling harder formations, will have teeth of tungsten carbide or some other hard material mounted on their cones. As the drill string rotates and the cones roll along the bottom of the hole, the individual hard teeth will induce compressive failure in the formation.
[0010] The bit's teeth must crush or cut rock, with the necessary forces supplied by the “weight on bit” (WOB) which presses the bit down into the rock, and by the torque applied at the rotary drive. While the WOB may in some cases be 100,000 pounds or more, the forces actually seen at the drill bit are not constant: the rock being cut may have harder and softer portions (and may break unevenly), and the drill string itself can oscillate in many different modes. Thus, the drill bit must be able to operate for long periods under high stresses in a remote environment.
[0011] When the bit wears out or breaks during drilling, it must be brought up out of the hole. This requires a process called “tripping”: a heavy hoist pulls the entire drill string out of the hole, in stages of (for example) about ninety feet at a time. After each stage of lifting, one “stand” of pipe is unscrewed and laid aside for reassembly (while the weight of the drill string is temporarily supported by another mechanism). Since the total weight of the drill string may be hundreds of tons and the length of the drill string may be tens of thousands of feet, this is not a trivial job. One trip can require tens of hours and is a significant expense in the drilling budget. To resume drilling, the entire process must be reversed. Thus, the bit's durability is very important to minimize round trips for bit replacement during drilling.
[0012] Background: Drill String Oscillation
[0013] The individual elements of a drill string appear heavy and rigid. However, in the complete drill string (which can be more than a mile long), the individual elements are quite flexible enough to allow oscillation at frequencies near the rotary speed. In fact, many different modes of oscillation are possible. (A simple demonstration of modes of oscillation can be done by twirling a piece of rope or chain: the rope can be twirled in a flat slow circle, or, at faster speeds, so that it appears to cross itself one or more times.) The drill string is actually a much more complex system than a hanging rope and can oscillate in many different ways; see WAVE PROPAGATION IN PETROLEUM ENGINEERING, Wilson C. Chin, (1994).
[0014] The oscillations are damped somewhat by the drilling mud, or by friction where the drill pipe rubs against the walls, or by the energy absorbed in fracturing the formation: but often these sources of damping are not enough to prevent oscillation. Since these oscillations occur down in the wellbore, they can be hard to detect but are generally undesirable. Drill string oscillations change the instantaneous force on the bit, and that means that the bit will not operate as designed. For example, the bit may drill oversize, or off-center, or may wear out much sooner than expected. Oscillations are hard to predict since different mechanical forces can combine to produce “coupled modes”; the problems of gyration and whirl are an example of this.
[0015] Background: Roller Cone Bit Design
[0016] The “cones” in a roller cone bit need not be perfectly conical (nor perfectly frustroconical), but often have a slightly swollen axial profile. Moreover, the axes of the cones do not have to intersect the centerline of the borehole. (The angular difference is referred to as the “offset” angle.) Another variable is the angle by which the centerline of the bearings intersects the horizontal plane of the bottom of the hole, and this angle is known as the journal angle. Thus, as the drill bit is rotated, the cones typically do not roll true, and a certain amount of gouging and scraping takes place. The gouging and scraping action is complex in nature, and varies in magnitude and direction depending on a number of variables.
[0017] Conventional roller cone bits can be divided into two broad categories: Insert bits and steel-tooth bits. Steel tooth bits are utilized most frequently in softer formation drilling, whereas insert bits are utilized most frequently in medium and hard formation drilling.
[0018] Steel-tooth bits have steel teeth formed integral to the cone. (A hardmetal is typically applied to the surface of the teeth to improve the wear resistance of the structure.) Insert bits have very hard inserts (e.g., specially selected grades of tungsten carbide) pressed into holes drilled into the cone surfaces. The inserts extend outwardly beyond the surface of the cones to form the “teeth” that comprise the cutting structures of the drill bit.
[0019] The design of the component elements in a rock bit are interrelated (together with the size limitations imposed by the overall diameter of the bit), and some of the design parameters are driven by the intended use of the product. For example, cone angle and offset can be modified to increase or decrease the amount of bottom hole scraping. Many other design parameters are limited in that an increase in one parameter may necessarily result in a decrease of another. For example, increases in tooth length may cause interference with the adjacent cones.
[0020] Background: Tooth Design
[0021] The teeth of steel tooth bits are predominantly of the inverted “V” shape. The included angle (i.e., the sharpness of the tip) and the length of the tooth will vary with the design of the bit. In bits designed for harder formations, the teeth will be shorter and the included angle will be greater. Heel row teeth (i.e., the teeth in the outermost row of the cone, next to the outer diameter of the borehole) may have a “T” shaped crest for additional wear resistance.
[0022] The most common shapes of inserts are spherical, conical, and chisel. Spherical inserts have a very small protrusion and are used for drilling the hardest formations. Conical inserts have a greater protrusion and a natural resistance to breakage, and are often used for drilling medium hard formations.
[0023] Chisel shaped inserts have opposing flats and a broad elongated crest, resembling the teeth of a steel tooth bit. Chisel shaped inserts are used for drilling soft to medium formations. The elongated crest of the chisel insert is normally oriented in alignment with the axis of cone rotation. Thus, unlike spherical and conical inserts, the chisel insert may be directionally oriented about its center axis. (This is true of any tooth which is not axially symmetric.) The axial angle of orientation is measured from the plane intersecting the center of the cone and the center of the tooth.
[0024] Background: Rock Mechanics and Formations
[0025] There are many factors that determine the drillability of a formation. These include, for example, compressive strength, hardness and/or abrasivity, elasticity, mineral content (stickiness), permeability, porosity, fluid content and interstitial pressure, and state of underground stress.
[0026] Soft formations were originally drilled with “fish-tail” drag bits, which sheared the formation away. Roller cone bits designed for drilling soft formations are designed to maximize the gouging and scraping action. To accomplish this, cones are offset to induce the largest allowable deviation from rolling on their true centers. Journal angles are small and cone-profile angles will have relatively large variations. Teeth are long, sharp, and widely-spaced to allow for the greatest possible penetration. Drilling in soft formations is characterized by low weight and high rotary speeds.
[0027] Hard formations are drilled by applying high weights on the drill bits and crushing the formation in compressive failure. The rock will fail when the applied load exceeds the strength of the rock. Roller cone bits designed for drilling hard formations are designed to roll as close as possible to a true roll, with little gouging or scraping action. Offset will be zero and journal angles will be higher. Teeth are short and closely spaced to prevent breakage under the high loads. Drilling in hard formations is characterized by high weight and low rotary speeds.
[0028] Medium formations are drilled by combining the features of soft and hard formation bits. The rock breaks away (is failed) by combining compressive forces with limited shearing and gouging action that is achieved by designing drill bits with a moderate amount of offset. Tooth length is designed for medium extensions as well. Drilling in medium formations is most often done with weights and rotary speeds between that of the hard and soft formations. Area drilling practices are evaluated to determine the optimum combinations.
[0029] Background: Roller Cone Bit Interaction with the Formation
[0030] In addition to improving drilling efficiency, the study of bottom hole patterns has allowed engineers to prevent detrimental phenomena such as those known as tracking, and gyration. The impressions a tooth makes into the formation depend largely on the design of the tooth, the tangential and radial scraping motions of the tooth, the force and speed with which the tooth impacts the formation, and the characteristics of the formation. Tracking occurs when the teeth of a drill bit fall into the impressions in the formation formed by other teeth at a preceding moment in time during the revolution of the drill bit. Gyration occurs when a drill bit fails to drill on-center. Both phenomena result in slow rates of penetration, detrimental wear of the cutting structures and premature failure of bits. Other detrimental conditions include excessive uncut rings in the bottom hole pattern. This condition can cause gyration, result in slow rates of penetration, detrimental wear of the cutting structures and premature failure of the bits. Another detrimental phenomenon is bit lateral vibration, which can be caused by radial force imbalances, bit mass imbalance, and bit/formation interaction among other things. This condition includes directional reversals and gyration about the hole center often known as whirl. Lateral vibration results in poor bit performance, overgage hole drilling, out-of-round, or “lobed” wellbores, and premature failure of both the cutting structures and bearing systems of bits. (Kenner and Isbell, DYNAMIC ANALYSIS REVEALS STABILITY OF ROLLER CONE ROCK BITS, SPE 28314, 1994).
[0031] Background: Bit Design
[0032] Currently, roller cone bit designs remain the result of generations of modifications made to original designs. The modifications are based on years of experience in evaluating bit records, dull bit conditions, and bottom hole patterns.
[0033] One method commonly used to discourage bit tracking is known as a staggered tooth design. In this design, the teeth are located at unequal intervals along the circumference of the cone. This is intended to interrupt the recurrent pattern of impressions on the bottom of the hole. Examples of this are shown in U.S. Pat. No. 4,187,922 and UK application 2,241,266.
[0034] Background: Shortcomings of Existing Bit Designs
[0035] The economics of drilling a well are strongly reliant on rate of penetration. Since the design of the cutting structure of a drill bit controls the bit's ability to achieve a high rate of penetration, cutting structure design plays a significant role in the overall economics of drilling a well. Current bit designs have not solved the issue of tracking. Complex mathematical models can simulate bottom hole patterns to a limited extent, but they do not suggest a solution to the ever-present problem of tracking. The known angular orientations of teeth designed to improve tooth impact strength leave excessive uncut bottom hole patterns and do not solve the problem of tracking. The known angular orientations of teeth designed to increase bottom hole coverage, fail to optimize tooth orientation and do not solve the problem of tracking. Staggered tooth designs do not prevent tracking of the outermost rows of teeth. On the outermost rows of each cone, the teeth are encountering impressions in the formation left by teeth on other cones. The staggered teeth are just as likely to track an impression as any other tooth. Another disadvantage to staggered designs is that they may cause fluctuations in cone rotational speed, resulting in fluctuations in tooth impact force and increased bit vibration. Bit vibration is very harmful to the life of the bit and the life of the entire drill string.
[0036] Background: Cutting Structure Design
[0037] In the publication A NEW WAY TO CHARACTERIZE THE GOUGING-SCRAPING ACTION OF ROLLER CONE BITS (Ma, Society of Petroleum Engineers No. 19448, 1989), the author determines that a tooth in the first (heel) row of the drill bit evaluated contacts the formation at −22 degrees (measured with respect to rotation of the cone about its journal) and begins to separate at an angle of −6 degrees. The author determines that the contacting range for the second row of the same cone is from −26 degrees to 6 degrees. The author states that “because the crest of the chisel inserts are always in the parallel direction with the generatrix of the roller cone . . . radial scraping will affect the sweep area only slightly.” The author concludes that scraping distance is a more important than the velocity of the cutter in determining performance.
[0038] In U.S. Pat. No. 5,197,555, Estes discloses a roller cone bit having opposite angular axial orientation of chisel shaped inserts in the first and second rows of a cone. This invention is premised on the determination that inserts scrape diagonally inboard and either to the leading side (facing in the direction of rotation) or to the trailing side (facing opposite to the direction of rotation). It is noted that the heel row inserts engage the formation to the leading side, while the second row inserts engage the formation to the trailing edge. In one embodiment, the inserts in the heel row are axially oriented at an angle between 30 degrees and 60 degrees, while the inserts in the second row are axially oriented between 300 degrees and 330 degrees. This orientation is designed to provide the inserts with a higher resistance to breakage. In an alternative embodiment, the inserts in the heel row are oriented at an axial angle between 300 degrees and 330 degrees, while the inserts in the second row are axially oriented between 30 degrees and 60 degrees. This orientation is designed to provide the inserts with a broader contact area with the formation for increased formation removal, and thereby an increased rate of penetration of the drill bit into the formation.
[0039] Background: Single Objective Optimization
[0040] A single objective optimization problem can be stated as
Minimize f(x)
G i ( x )=0, i=1, . . . m
Subject to: G j ( x )≦0, j=1, . . . n (1)
x l ≦x≦x u
[0041] Where x is the vector of design parameters, f(x) is the objective function, G(x) is a vector function representing the equality and inequality constraints. Both objective function and constraint function may be linear or nonlinear functions.
[0042] Roller Cone Bit Design Using Multi-Objective Optimization
[0043] Design of roller cone drill bits is a complicated procedure, and optimization is very difficult. Before the late 1990s, optimization was normally a one-at-a-time activity of skilled designers. Since the 1999 publications of the present inventor, computer software has begun to be actually used in the design process in a new way, helping the designer refine and optimize specific designs for specific drilling conditions and formation properties.
[0044] The ultimate goals of drill bit design are rate of penetration and durability or bit life, but many intermediate targets can be used to help achieve these ultimate goals. For example, it is desirable that the average bit-axial force component be approximately equal on the three arms of the bit (“force balance”), and/or that the average volumetric rate of material removal be equal for the three cones of the bit (“energy balance”). For another example, it is generally desirable to minimize the bit net lateral force due to the tooth interactions with the hole bottom (“lateral balance”).
[0045] The question is how to address these intermediate objectives. The present application describes techniques for optimization of drill bit designs using multiple objectives. Multi-objective optimization permits various factors to be taken into account in a balanced way, without having to decide which factor is most important, or which factors will be dependent on each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The disclosed inventions will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:
[0047] [0047]FIG. 1 is a flow chart of the optimization procedure disclosed in the present invention.
[0048] [0048]FIG. 2 shows the tangential and radial velocity components of tooth trajectory, viewed through the cutting face (i.e., looking up).
[0049] [0049]FIGS. 3A, 3B, 3 C, and 3 D show plots of planar tooth trajectories for teeth in four rows of a single cone, referenced to the XY coordinates of FIG. 2.
[0050] [0050]FIGS. 4A and 4B show tangential and radial scraping distances, respectively, for the four tooth trajectories shown in FIGS. 3A-3D.
[0051] [0051]FIG. 5 is a sectional view of a cone (normal to its axis), showing how the tooth orientation is defined.
[0052] [0052]FIG. 6 shows time-domain plots of tooth tangential speed, for the five rows of a sample cone, over the duration of the trajectory for each row.
[0053] [0053]FIGS. 7A and 7B show how optimization of tooth orientation can perturb the width of uncut rings on the hole bottom.
[0054] [0054]FIGS. 8A and 8B show how optimization of tooth orientation can disturb the tooth clearances.
[0055] [0055]FIGS. 9A, 9B and 9 C show the screen views which a skilled bit designer would see, according to some embodiments of the invention, while working on a bit optimization which included optimization of tooth orientation.
[0056] [0056]FIG. 10 shows a drill rig in which bits optimized by the teachings of the present application can be advantageously employed.
[0057] [0057]FIG. 11 shows a conventional roller cone bit, and FIG. 12 shows a conventional drag bit.
[0058] [0058]FIG. 13 shows a sample XYZ plot of a non-axisymmetric tooth tip.
[0059] [0059]FIG. 14 shows axial and sectional views of the i-th cone, and illustrates the enumeration of rows and teeth.
[0060] [0060]FIGS. 15A-15D show how the planarized tooth trajectories vary as the offset is increased.
[0061] [0061]FIGS. 16A-16D show how the ERSD and ETSD values vary for all rows of a given cone as offset is increased.
[0062] [0062]FIG. 17 depicts the three major components of forces on a cone: axial bearing force, weight on cone, and cone moment.
[0063] [0063]FIG. 18 a is an illustration of a conventional unbalanced milled steel tooth bit 1810 . FIG. 18 b lists the rock volume, weight on cone, bearing force, and bearing moment for each of the three cones of the unbalanced bit 1810 .
[0064] [0064]FIG. 19 a shows the optimization of a nonlinear constraint requiring the minimal distance between teeth surfaces be 0.041317 inch. FIG. 19 b shows the optimization of another nonlinear constraint controlling the size of uncut bridges between teeth row. FIG. 19 c depicts a curved trajectory used to determine the lower and upper bounds of tooth orientation angles.
[0065] [0065]FIGS. 20 a - c show the optimization of the tooth crest length and tooth locations on cones 1 - 3 , respectively, before and after optimization.
[0066] [0066]FIGS. 21 a is an illustration of the now energy-balanced milled steel tooth bit 1810 . FIGS. 21 b lists the rock volume, weight on cone, bearing force, and bearing moment for each of the three cones of the balanced bit 1810 .
[0067] [0067]FIGS. 22 a illustrates the definition of a negative and positive tooth orientation angle. FIGS. 22 b lists the orientation angles used for all three cones in energy-balanced bit 1810 .
[0068] [0068]FIGS. 23A-23C shows a sample embodiment of a bit design process, using the teachings of the present application.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0069] The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment (by way of example, and not of limitation).
[0070] Overview of Sample Design Process
[0071] [0071]FIGS. 23A-23C show a sample embodiment of a bit design process using the teachings of the present application. Specifically, FIG. 23A shows an overview of the design process, and FIGS. 23B and 23C expand specific parts of the process.
[0072] First, the bit geometry, rock properties, and bit operational parameters are input (step 102 ). The 3D tooth shape, cone profile, cone layout, 3D cone, 3D bit, and 2D hole profile are then displayed (step 104 ).
[0073] Since there are two types of rotation relevant to the calculation of the hole bottom (cone rotation and bit rotation), transformation matrices from cone to bit coordinates must be calculated (step 106 ). (See FIG. 23B.) The number of bit revolutions is input (step 108 ), and each cone is counted (step 110 ), followed by each row of teeth for each cone (step 112 ). Next, the type of teeth of each row is identified (step 114 ), and the teeth are counted (step 116 ). Next, a time interval delta is set (step 118 ), and the position of each tooth is calculated at this time interval (step 120 ). If a given tooth is not “cutting” (i.e., in contact with the hole bottom), then the algorithm continues counting until a cutting tooth is reached (step 122 ). The tooth trajectory, speed, scraping distance, crater distribution, coverage ratio, and tracking ratios for all rows, cones, and the bit are calculated (step 124 ). This section of the process (depicted in FIG. 23B) gives the teeth motion over the hole bottom and displays the results (step 126 ).
[0074] Next, the bit mechanics are calculated. (See FIG. 23C.) Again, transformation matrices from cone to bit coordinates are calculated (step 128 ), and the number of bit revolutions and maximum time steps, delta, are input (step 130 ). The cones are then counted (step 132 ). The bit and cone rotation angles are calculated at the given time step (step 134 ), and the rows are counted (step 136 ). Next, the 3D tooth surface matrices for the teeth on a given row are calculated (step 138 ). The teeth are then counted (step 140 ), and the 3D position of the tooth on the hole bottom is calculated at the given time interval (step 142 ). If a tooth is not cutting, counting continues until a cutting tooth is reached (step 144 ). The cutting depth, area, volume, and forces for each tooth are calculated, and the hole bottom model is updated (based on the crater model for the type of rock being drilled). Next, the number of teeth cutting at any given time step is counted. The tooth force is projected into cone and bit coordinates, yielding the total cone and bit forces and moments. Finally, the specific energy of the bit is calculated (step 146 ).
[0075] Finally, all results are outputted (step 148 ). The process can then be reiterated if needed.
[0076] Four Coordinate Systems
[0077] Four coordinate systems are used, in the presently preferred embodiment, to define the crest point of a tooth in three-dimensional space. All the coordinate system obey the “Right Hand Rule”. These coordinate systems—tooth, cone, bit, and hole—are described below.
[0078] Local Tooth Coordinates
[0079] [0079]FIG. 13 shows a sample XYZ plot of a tooth tip (in tooth local coordinates). Tooth coordinates will be indicated here by the subscript t. (Of course, each tooth has its own tooth coordinate system.) The center of the X t Y t Z t coordinate system, in the presently preferred embodiment, is located at the tooth center. The coordinate of a tooth's crest point P t will be defined by parameters of the tooth profile (e.g., tooth diameter, extension, etc.).
[0080] Cone Coordinates
[0081] [0081]FIG. 14 shows axial and sectional views of the i-th cone, and illustrates the enumeration of rows and teeth. Cone coordinates will be indicated here by the subscript c. The center of the cone coordinates is located in the center of backface of the cone. The cone body is fixed with respect to these coordinates, and hence THESE COORDINATES ROTATE WITH THE CONE. (Of course, each cone has its own cone coordinate system.) The axis Z c coincides with the cone axis, and is oriented towards to the bit center. Cone axes Y c and X c , together with axis Z c , follow the right hand rule. As shown in FIG. 13, four parameters are enough to completely define the coordinate of the crest point of a tooth on cone profile. These four parameters are H c , R c , φ c , and θ c . For all the teeth on the same row, H c , R c , and φ c are the same.
[0082] Bit Coordinates
[0083] Similarly, a set of bit axes X b Y b Z b , indicated by the subscript b, is aligned to the bit. The bit is fixed with respect to these coordinates, and hence THESE COORDINATES ROTATE WITH THE BIT. Axis Z b preferably points toward the cutting face, and axes X b and Y b are normal to Z b (and follow the right-hand rule).
[0084] Hole Coordinates
[0085] The simplest coordinate system is defined by the hole axes X h Y h Z h , which are fixed in space. Note, however, that axes Z b and Z h may not be coincident if the bit is tilted. FIG. 2 shows the tangential and radial velocity components of tooth trajectory viewed through the cutting face (i.e., looking up). Illustrated is a small portion of a tooth trajectory, wherein a tooth's crest (projected into an X h Y h plane which approximates the bottom of the hole) moves from point A to point B, over an arc distance ds and a radial distance dr.
[0086] Transformations
[0087] Since all of these coordinate systems are xyz systems, they can be interrelated by simple matrix transformations.
[0088] Both the bit and the cones are rotating with time. In order to calculate the position on hole bottom where the crest point of a tooth engages into formation and the position that the crest point of a tooth disengages from formation, all the teeth positions at any time must be described in hole coordinate system X h Y h Z h .
[0089] The transformation from tooth coordinates X t Y t Z t to cone coordinates X c Y c Z c can be defined by a matrix Rtc, which is a matrix function of teeth parameters:
Rtc= ƒ( H c , R c , θ c , φ c ),
[0090] so that any point P t in X t Y t Z t can be transformed into local cone coordinates X c Y c Z c by:
P C =R tC *P t .
[0091] At time t=0, it is assumed that the plane X c O c Z c is parallel to the bit axis. At time t, the cone has a rotation angle λ around its negative axis (−Z c ). Any point on the cone moves to a new position due to this rotation. The new position of P c in X c Y c Z c can be determined by combining linear transforms.
[0092] The transform matrix due to cone rotation is R cone :
R cone =cos(λ) I +(1−cos(λ)) NcNc ′+sin(λ) Mc,
[0093] where N c is the rotation vector and M c is a 3*3 matrix defined by N c .
[0094] Therefore, the new position P crot of P c due to cone rotation is:
P
crot
=R
cone
*P
c
[0095] Let R cb1 , R cb2 , and R cb3 be respective transformation matrices (for cones 1 , 2 , and 3 ) from cone coordinate to bit coordinates. (These matrices will be functions of bit parameters such as pin angle, offset, and back face length.) Any point P ci in cone coordinates can then be transformed into bit coordinates by:
P b =R cbi *P ci +P c0i for i=1, 2, or 3,
[0096] where P c0i is the origin of cone coordinates in the bit coordinate system.
[0097] The bit is rotating around its own axis. Let us assume that the bit axes and hole axes are coincident at time t=0. At time t, the bit has a rotation angle β. The transform matrix due to bit rotation is:
Rbh =cos(β) I +(1−cos(β)) NbNb ′+sin(β) Mb
[0098] where Nb is the rotation vector and Mb is a 3*3 matrix defined by Nb. Therefore, any point Pb in bit coordinate system can be transformed into the hole coordinate system X h Y h Z h by:
Ph=Rbh *Pb.
[0099] Therefore, the position of the crest point of any tooth at any time in three-dimensional space has been fully defined by the foregoing seven equations. In order to further determine the engage and disengage point, the formation is modeled, in the presently preferred embodiment, by multiple stepped horizontal planes. (The number of horizontal planes depends on the total number of rows in the bit.) In this way, the trajectory of any tooth on hole bottom can be determined.
[0100] Calculation of Trajectories in Bottomhole Plane
[0101] With the foregoing transformations, the trajectory of the tooth crest across the bottom of the hole can be calculated. FIGS. 3A, 3B, 3 C, and 3 D show plots of planar tooth trajectories, referenced to the hole coordinates XhYh, for teeth on four different rows of a particular roller cone bit. The teeth on the outermost row (first row) scrapes toward the leading side of the cone. Its radial and tangential scraping distances are similar, as can be seen by comparing the first bar in FIG. 4A with the first bar in FIG. 4B. However, for teeth on the second row, the radial scraping motion is much larger than the tangent motion. The teeth on the third row scrape toward the trailing side of the cone, and the teeth on the forth row scrape toward the leading side of the cone.
[0102] [0102]FIGS. 4A and 4B show per-bit-revolution tangential and radial scraping distances, respectively, for the four tooth trajectories shown in FIGS. 3A-3D. Note that, in this example, the motion of the second row is almost entirely radial and not tangential.
[0103] Projection of Trajectories into Cone Coordinates
[0104] The tooth trajectories described above are projected on the hole bottom which is fixed in space. In this way, it is clearly seen how the tooth scrapes over the bottom. However, for the bit manufacturer or bit designer, it is necessary to know the teeth orientation angle on the cone coordinate in order either to keep the elongate side of the tooth perpendicular to the scraping direction (for maximum cutting rate in softer formations) or to keep the elongate side of the tooth in line with the scraping direction (for durability in harder formations). To this end, the tooth trajectories are projected to the cone coordinate system. Let P 1 ={x 1 , y 1 , z 1 } c and P 2 ={x 2 , y 2 , z 2 } c be the engage and disengage points on cone coordinate system, respectively, and approximate the tooth trajectory P 1 -P 2 as a straight line. Then the scraping angle in cone coordinates is:
R S = ( x 2 - x 1 ) 2 + ( y 1 + y 2 ) 2 and γ s = tan - 1 ( R S z 2 - z 1 )
[0105] The teeth can then be oriented appropriately with respect to this angle gamma. For example, for soft formation drilling the tooth would preferably be oriented so that its broad side is perpendicular to the scraping direction, in order to increase its rate of rock removal. In this case, the direction γ c of the elongate crest of the tooth, in cone coordinates, is normal to γ s , i.e., γ c =γ s +π/2. Conversely, for drilling harder formations with a chisel-shaped tooth it might be preferable to orient the tooth with minimum frontal area in the direction of scraping, i.e., with γ c =γ s .
[0106] Derivation of Equivalent Radial and Tangential Scraping
[0107] There are numerous parameters in roller cone design, and experienced designers already know, qualitatively, that changes in cone shape (cone angle, heel angle, third angle, and oversize angle) as well as offset and journal angle will affect the scraping pattern of teeth in order to get a desired action-on-bottom. One problem is that it is not easy to describe a desired action-on-bottom quantitatively. The present application provides techniques for addressing this need.
[0108] Two new parameters have been defined in order to quantitatively evaluate the cone shape and offset effects on tooth scraping motion. Both of these parameters can be applied either to a bit or to individual cones.
[0109] (1) Equivalent Tangent Scraping Distance (ETSD) is equal to the total tangent scraping distance of all teeth on a cone (or bit) divided by the total number of the teeth on the cone (or bit).
[0110] (2) Equivalent Radial Scraping Distance (ERSD) is equal to the total radial scraping distance of all teeth on a cone (or bit) divided by the total number of the teeth on the cone (or bit).
[0111] Both of these two parameters they have much more clear physical meaning than the offset value and cone shape.
[0112] Surprisingly, the arcuate (or bulged) shape of the cone primarily affects the ETSD value, and the offset determines the ERSD value. Also surprisingly, the ERSD is not equal to zero even at zero offset. In other words, the teeth on a bit without offset may still have some small radial scraping effects.
[0113] The radial scraping direction for all teeth is always toward to the hole center (positive). However, the tangential scraping direction is usually different from row to row.
[0114] In order to use the scraping effects fully and effectively, the leading side of the elongated teeth crest should be orientated at an angle to the plane of the cone's axis, which is calculated as described above for any given row.
[0115] [0115]FIG. 2 shows the procedure in which a tooth cuts into (point A) and out (point B) the formation. Due to bit offset, arcuate cone shape and bit and cone rotations, the motion from A to B can be divided into two parts: tangent motion ds and radial motion dr. Notice the tangent and radial motions are defined in hole coordinate system XhYh. Because ds and dr vary from row to row and from cone to cone, we derive an equivalent tangent scraping distance (ETSD) and an equivalent radial scraping distance (ERSD) for a whole cone (or for an entire bit).
[0116] For a cone, we have
ETDS = ∑ j Nr ds j Nt j Nc and ERSD = ∑ j Nr dr j Nt j Nc
[0117] where Nc is the total tooth count of a cone and Nr is the number of rows of a cone.
[0118] Similarly for a bit, we have
ETSD = ∑ i 3 ∑ j Nr ds ij Nt ij Nb and ERSD = ∑ i 3 ∑ j Nr dr ij Nt ij Nb
[0119] where Nb is the total tooth count of the bit.
[0120] [0120]FIGS. 15A-15D show how the planarized tooth trajectories vary as the offset is increased. These figures clearly show that with the increase of the offset value, the radial scraping distance is increased. Surprisingly, the radial scraping distance is not equal to zero even if the offset is zero. This is due to the arcuate shape of the cone.
[0121] [0121]FIGS. 16A-16D show how the ERSD and ETSD values vary for all rows of a given cone as offset is increased. From these Figures, it can be seen that the tangent scraping distance of the gage row, while very small compared to other rows but is not equal to zero. It means that there is a sliding even for the teeth on the driving row. This fact may be explained by looking at the tangent speed during the entry and exit of teeth into and out of the rock. (FIG. 6 shows time-domain plots of tooth tangential speed, for the five rows of a sample cone, over the duration of the trajectory for each row.) During the cutting procedure, the tangent speed is not equal to zero except for one instant. Because the sliding speed changes with time, the instantaneous speed is not the best way to describe the teeth/rock interaction.
[0122] Note that the tangent scraping directions are different from row to row for the same cone. FIG. 5 is a sectional view of a cone (normal to its axis), showing how the tooth orientation is defined in the present application: the positive direction is defined as the same direction as the bit rotation. This means that the leading side of tooth on one row may be different from that on another row.
[0123] The ERSD increases almost proportionally with the increase of the bit offset. However, ERSD is not zero even if the bit offset is zero. This is because the radial sliding speed is not always zero during the procedure of tooth cutting into and cutting out the rock.
[0124] Calculation of Uncut Rings, and Row Position Adjustment
[0125] [0125]FIGS. 7A and 7B show how optimization of tooth orientation can perturb the width of uncut rings on the hole bottom. The width of uncut rings is one of the design constraints: a sufficiently narrow uncut ring will be easily fractured by adjacent cutter action and mud flows, but too large an uncut ring will slow rate of penetration. Thus, one of the significant teachings of the present application is that tooth orientation should not be adjusted in isolation, but preferably should be optimized jointly with the width of uncut rings.
[0126] Interference Check
[0127] Another constraint is tooth interference. In the crowded geometries of an optimized roller cone design, it is easy for an adjustment to row position to cause interference between cones. FIGS. 8A and 8B graphically show how optimization of tooth orientation can disturb the tooth clearances. Thus, optimization of tooth orientation is preferably followed by an interference check (especially if row positions are changed).
[0128] Iteration
[0129] Preferably, multiple iterations of the various optimizations are used, to ensure that the various constraints and/or requirements are all jointly satisfied according to an optimal tradeoff.
[0130] Graphic Display
[0131] The scraping motion of any tooth on any row is visualized on the designer's computer screen. The bit designer has a chance to see quantitatively how large the motion is and in which direction if bit geometric parameters like cone shape and offset are changed.
[0132] [0132]FIGS. 9A, 9B and 9 C show the screen views which a skilled bit designer would see, according to some embodiments of the invention, while working on a bit optimization which included optimization of tooth orientation. These three views show representations of tooth orientation and scraping direction for each tooth row on each of the three cones. This simple display allows the designer to get a feel for the effect of various parameter variations
[0133] Multi-objective Optimization
[0134] Multi-objective optimization is concerned with the minimization of a vector of objectives F(x) that may be the subject of a number of constraints:
Minimize F(x)
G i ( x )=0, i=1, . . . m
Subject to: G j ( x )≦0, j=1, . . . n (2)
x l ≦x≦x u
[0135] Where x is a design variable with lower and upper bounds. F(x) is a vector and represents multiple objectives. G(x) is a vector function representing the equality and inequality constraints. Both objective function and constraint function may be linear or nonlinear functions.
[0136] There are many algorithms available to solve this multi-objective optimization problem. Goal Attainment Method developed by Gembicki and its modifications is one of the most efficient methods.
[0137] Modifications of an Objective
[0138] In multi-objective optimization, objectives may have different physical meanings, and their numerical values may significantly differ from each other. In this case, modifications of objective expression become necessary. For example, if one objective function is volumetric balance, that can be evaluated as the sum of the squares of the differences of each cone's rate from the average rate, i.e.
V 0 =( V 1 −V avg ) 2 +( V 2 −V avg ) 2 +( V 3 −V avg ) 2 . (3)
[0139] This formula (or some analogous formula, as discussed below) provides a single scalar value for each objective function. However, some further manipulation is preferably used to combine them.
[0140] Numerical Combination of Objective Values: Ultimately the separate objective values will be combined with some formula such as
Net Value=( A−A 0 ) 2 +( B−B 0 ) 2 +. . . (4)
or more generally
Net Value= Summa{w j (| A j −A j0 )| Ej )} (5)
[0141] where
[0142] A j is the j-th objective function value,
[0143] E j is the nonlinearity value for that objective function, and
[0144] W j is a weight given to the j-th objective function. (All the w j values add up to 1.)
[0145] Normalization: In the above example, the volume imbalance V 0 would ideally be zero. However, for nonzero values of V 0 , the size of V 0 will depend somewhat on V avg . Therefore, V 0 can be normalized to make it independent of the magnitude of V avg , e.g.
V* 0 =V 0 /V avg . (6)
[0146] Other objective functions can optionally be normalized in a similar way.
[0147] Translation: The above formula for V 0 was set up so that the ideal outcome would be V 0 =0. However, if another definition had been used, this would not necessarily be true. For example, if the definition
V′ 0 =( V 1 /( V 2 +V 3 )) 2 +( V 2 /( V 1 +V 3 )) 2 +( V 3 /( V 1 +V 2 ) (7)
[0148] is used, then the ideal value of V′ 0 would be 0.75. In this case, the definitions can optionally be translated so that the ideal value is zero, e.g.
V′*= 0.75− V′ 0 (8)
[0149] Scaling: Optionally, the objective functions can be scaled into values which all have comparable significance, e.g., where 0 is the ideal value for each objective, the objective values can be scaled so that values below 1 are wholly acceptable (almost perfect), and values above 10 are unacceptable.
[0150] Inversion: In some cases, the natural definition of the objective might be to make the largest possible value preferable. (A simple example of this is ROP.) One way to scale this, for comparability with other objectives, is to use a simple inversion, e.g., objective B might be defined as B=1/ROP.
[0151] Segmentation: Optionally, the objective function can be constructed using a combination of different relations. For example, if an objective X is scaled so that values of X below 1 are considered to provide no further advantage, then a revised objective value can be defined, for example, as
X″=X 2 when |X|≧1,
X″=X 8 when |X|<1. (9)
[0152] Note that this particular example retains continuity, which can help to assure that the optimization procedure converges.
[0153] Nonlinearity: Optionally, exponents on the different components can be made higher than 2, or made higher than 2 when the objective exceeds a certain preferred maximum value. This provides increased sensitivity to excursions of any one objective if desired.
[0154] Application of Multi-objective Optimization in Roller Cone Bit Design
[0155] Multiple Objectives
[0156] Drilling faster and longer are almost always the major objectives in designing a roller cone bit. In order to meet this objective, innovative design methods have been developed in recent years. One of the innovative methods is the optimization of teeth orientation. Another is the balanced cutting structures of roller cone bit.
[0157] In summary, a “perfect” roller cone bit has following objectives:
[0158] (1) Maximization of rate of penetration (drilling efficiency)
[0159] (2) Maximization of bit life (durability)
[0160] The above two objectives may be met by fulfilling some or all of the following sub-objectives:
[0161] (a) Maximization of the shear motion by teeth orientation
[0162] (b) Maximization of rock volume removed by each tooth
[0163] (c) Minimization of the difference of weight on each cone
[0164] (d) Minimization of the difference of bearing axial force on each bearing
[0165] (e) Minimization of the difference of cone moment on each cone
[0166] (f) Minimization of the lateral force of the bit
[0167] (g) Minimization of the tracking probability
[0168] (h) Minimization of the difference of rock volume removed by each cone
[0169] (i) Minimization of the difference of the work done by each cone
[0170] (j) Minimization of the difference of the wear on inner cutting structure and outer cutting structure
[0171] (k) Minimization of the difference of the insert wear of the bit
[0172] (l) Minimization of the difference of the loadings on each insert
[0173] (m) Minimization of the shock loadings on tooth, on cone and on bit
[0174] (n) . . .
[0175] These sub-objectives may be difficult to meet simultaneously and may be traded off in some way. A bit design engineer may usually be able to know the relative importance of these objectives. However, as the number of objectives increases, trade-offs are likely to become complex and less easily quantified. Therefore, it is necessary to develop a computer program to automate the optimization procedure once the objectives are selected or determined.
[0176] Multi-objectives of an Energy-Balanced Roller Cone Bit
[0177] In this section, it will be shown, as an example, how an energy-balanced roller cone bit is designed by using the multi-objective technology. It is required to design a roller cone bit with balanced cutting structure. The balanced cutting structure means that each cone removes the same amount of rock (volume balancing) and each cone subject to the same loads (force balancing). From the cone coordinate system, there are six forces acting on each cone: three linear forces and three moments. From the bit coordinate system, there are still six forces: three linear forces and three moments. However, the bit axial forces on each cone or weight on cone (WOC) are the most important forces because they relate directly to the weight on bit (WOB). It will be difficult to design a roller cone bit in which each cone is subject to the same forces in all directions. The three forces shown in FIG. 17 are considered as the most important forces acting on each cone which directly affect the bit performance: a force 1710 along bearing axial direction, Fb, a force 1711 along bit axial direction (weight on cone), Fw, and a moment 1712 Mc. Therefore, the objectives of an energy-balanced roller cone bit design can be defined as follows:
Objective 1 : V max - V min V mean ≤ ξ v ( 10 a ) Objective 2 : Fb max - Fb min Fb mean ≤ ξ Fb ( 10 b ) Objective 3 : Fw max - Fw min Fw mean ≤ ξ Fw ( 10 c ) Objective 4 : M c max - M c min M c mean ≤ ξ M c ( 10 d )
[0178] Where V max =max(V 1 , V 2 , V 3 ), and V min =min(V 1 , V 2 , V 3 ), and V mean =mean(V 1 , V 2 , V 3 ), and V 1 , V 2 , V 3 are rock removed by each cone, respectively.
[0179] Fb max =max(Fb 1 , Fb 2 , Fb 3 ), and Fb min =min(Fb 1 , Fb 2 , Fb 3 ), and Fb mean =mean(Fb 1 , Fb 2 , Fb 3 ), and Fb 1 , Fb 2 , Fb 3 are bearing axial force of each cone, respectively.
[0180] FW max =max(Fw 1 , Fw 2 , Fw 3 )x and Fw min =min(Fw 1 , Fw 2 , Fw 3 ), and Fw mean =mean(Fw 1 , Fw 2 , Fw 3 ), and Fw 1 , Fw 2 ,Fw 3 are weight on each cone, respectively.
[0181] Mc max =max(Mc 1 , Mc 2 , Mc 3 )x and Mc min =min(Mc 1 , Mc 2 , Mc 3 ), and Mc mean =mean(Mc 1 , Mc 2 , Mc 3 ), and Mc 1 , Mc 2 , Mc 3 are moment on each cone, respectively.
[0182] The balancing criterion defined by ξ v ,ξ Fb ,ξ Fw ,ξ Mc , depend on bit type, bit size. For insert type bit, these numbers should be less than 4%. For steel tooth bit, these numbers should be less than 5%. In most cases, these numbers are less than 2% for any type of roller cone bits.
[0183] Objectives as a Function of Design Variables
[0184] The above objectives must be expressed mathematically as functions of design variable. However, it is very difficult to express them explicitly because of the complicated three-dimensional bit geometry and the interaction between the teeth and the formation. Instead, a computer subroutine is developed in which design variables are the inputs, and objectives are the output.
[0185] As described in U.S. Pat. No. 6,213,225, a tooth is divided into many three-dimensional elements. The force acting on an element is proportional to the rock volume removed by that element. In order to calculate the forces acting on an element, it is necessary to first determine the rock volume removed by this element. To this end, a model to simulate the interaction between teeth and formation is needed. There are two kinds of models that may be used to calculate the volumes and forces.
[0186] (1) Volume and Forces Calculated from Three-Dimensional Model
[0187] A three-dimensional model of the interaction of the roller cone bit and formation has been developed, and the simulation procedure has been described in U.S. Pat. Nos. 6,095,262 and 6,213,225. Once bit geometric parameters, drilling operational parameters, and formation properties are defined, the three-dimensional model is able to simulate the drilling procedure in time domain. Therefore, the rock removed by any cutting element and the forces acting on any cutting element at any time step can be obtained. However, the run of the model is time costly. For example, a 20-second drilling simulation of an 12¼ steel tooth bit may need five minutes of CPU time. As a result, it is difficult to directly implement the three-dimensional model into the design optimization because optimization itself usually needs several hundreds of iterations. Therefore, it is necessary to first simplify a three-dimensional problem into a two-dimensional one as described below.
[0188] (2) Volume and Forces Calculated from Two-Dimensional Model
[0189] In this two-dimensional model, the cutting structure of a roller cone bit is projected to a vertical plane passing through the bit axis. The surface of the bottom hole is then formed by rotating the projected profile around the bit axis 360 degrees. Suppose a bit has a cutting depth A in one bit revolution. And for all teeth that are in cutting with the formation, the cutting depth A is assumed to be the same. Therefore, if the rotational speeds of the cone and bit are known, the crater distribution on the bottom will be able to be determined. At this time, it would be simple to calculate the rock volume removed by all the teeth. The volume matrix representing the volume removed by each row may have the form:
V=[V ij ],i=1,2,3; j=1,2,3,4 . . . (11)
[0190] Where i represents the cone number and j the row number. The elements of this matrix are all the functions of the design variables.
[0191] (3) Scaled Volume and Forces Used in the Optimization
[0192] In reality, the volume removed by each row depends not only on the above design variable, but also on the tracking condition and the three-dimensional bottom hole condition which vary with time. However, these condition changes are difficult to be sufficiently represented in a two-dimensional model. Therefore, the matrix V from the two-dimensional model must be scaled. The scaled matrix may be obtained from both two-dimensional and three-dimensional models as follows:
K v ( i,j )= V 3d0 ( i,j )/ V 2d0 ( i,j ) (12)
[0193] where V 3d0 (i,j) is the volume matrix of the initial designed bit under three-dimensional simulation. And V 2d0 (i,j) is the volume matrix of the initial designed bit under two-dimensional simulation.
[0194] The final scaled volume matrix has the following form:
V b ( i,j )= K v ( i,j )/ V ( i,j ) (13)
[0195] Let V 1 , V 2 , V 3 be the volume removed by cone 1 , cone 2 , and cone 3 , and this leads to
V i = ∑ i ∑ j V b ( i , j ) ( 14 )
[0196] Where V i are implicit functions of the design variables. At this point, Objective 1 is defined as:
Objective 1 : V max - V min V mean ≤ ξ v ( 10 a )
[0197] Similarly, the forces acting on each tooth and each cone can be calculated based on matrix V b (i,j). Therefore, the other three objectives related to forces can also be expressed as implicit functions of design variables in the same way and will not be described here.
[0198] Design Variables
[0199] There are many geometric parameters which can be taken as design variables: bit offset, bearing angle (pin angle), cone profile, row position, number of tooth row, number of teeth, tooth geometry (extension, crest length), tooth orientation angles, etc.
[0200] Constraints on Design Variables
[0201] There are two kinds of constraints: linear and nonlinear. The linear constraints are simply the bounds of design variables. For example, the lower and upper bounds of a tooth crest length are determined by requirements on tooth mechanical strength and structural limitation. Another example is the lower and upper bounds of the orientation angle that are calculated from the curved tooth trajectories described in U.S. Pat. No. 6,095,262. FIG. 19 c shows an example of a curved trajectory 1910 .
[0202] The nonlinear constraints represent the relationship among some design variables. A typical nonlinear constraint is the clearance between teeth surfaces on all three cones. FIG. 19 a shows the optimization requiring the minimal distance between teeth surfaces to be 0.041317 inch. In order to keep the cone rotate smoothly without teeth interference, a minimum clearance, δ, is required. The clearance can be expressed as a function of the design variables:
g 1 ( x 1 , . . . ,x n )≦δ (15)
[0203] Another nonlinear constraint is the width of the uncut formation rings (bridges) on bottom. FIG. 19 b shows the optimization of this nonlinear constraint. This width should be minimized or equalized to avoid the direct contact of cone surface to formation. This condition can be expressed as:
Δ w min ≦g 2 ( x 1 , . . . ,x n )≦Δ w max (16)
[0204] Of course, the explicit expressions of such constraints are difficult to develop. Instead, a computer subroutine is developed where design variables are then input, and clearance is the output.
[0205] Software Development
[0206] The techniques for solving a multi-objective optimization problem are wide and varied. Among others, the Weighted Sum Method, the Single Objective Method and the Goal Attainment Method are used very often in engineering (Gembicki, 1974, Grace, 1989).
[0207] The Goal Attainment Method is applied to solve the multi-objective optimization of the roller cone bit. Using this method, the objectives and the constraints defined above can now be expressed as a standard multi-objective optimization problem using the following formulations:
Minimize γ
f 1 ( x )− w i γ≦g i , i=1,2, . . . m
G i ( x )=0, i=1, . . . m
Subject to: G j ( x )≦0, j=1, . . . n
x l ≦x≦x u
[0208] Where f i (x) is the i-th objective, which is, in this case, one of the 4 objectives, g i , is the associated design goal which is, in this case, the expressions of the right hand side of the objectives. w i is a set of weighting coefficients that determines the search direction, and x is a set of design variables.
[0209] During the optimization, γ is varied, which changes the size of the feasible region. The introduction of the term w i γ into the problem enables the designer to always find a reasonable optimal solution even when the objectives and constraints are not adequately defined.
[0210] Design Procedure
[0211] An overview of the design process is shown in FIG. 1. First, the initial bit file, formation, and operational parameters are read (step 1002 ). The optimization objectives based on bit size and bit type are defined (step 1004 ). Begin three-dimensional drilling simulation. Output forces on tooth, on cone and on bit, bit-balanced conditions, bottom hole pattern, etc. (step 1006 ). If all the objectives are not met (step 1008 ), then the algorithm continues by defining design variables and their bounds and generating linear and nonlinear constraints (step 1010 ). The algorithm then calls the defined two-dimensional bit/formation interaction model and scales the two-dimensional results using the initial three-dimensional results (step 1012 ). Multi-objective optimization then begins (step 1014 ). If the optimization is successful (step 1016 ), then the bit is redesigned using the optimized bit parameters (step 1018 ). If not, steps 1010 to 1014 are repeated until optimization is successful.
[0212] It should be noted that although the optimization procedure is based on the results of a two-dimensional model, the initial results of the bit from three-dimensional model must be first obtained in order to scale the results of the two-dimensional model. And the final bit design is evaluated using the results from three-dimensional model. In some cases, a bit is optimized in two-dimensional model and may not be optimized in three-dimensional model. If this case occurs, the total optimization procedure must be repeated over again, and the objectives and bounds of design variables have to be changed.
Design Examples
[0213] A 12¼″ steel tooth bit (IADC 117) 1810 shown in FIG. 18 a is used as an example. As shown in FIG. 18 b, the conventional bit was unbalanced. The difference of rock removed by each cone was about 7.2%. The difference between bearing axial force is as high as 11.1%. Bit 1810 is redesigned and shown in FIGS. 21 a. The balanced condition is shown in FIGS. 21 b. It is seen that three cones now remove almost the same amount of rock volume and are subject to almost the same loads. The bearing force and the cone moment are not so well balanced, but the differences are less than 5%. Field run experience of the bit shows that this difference is acceptable. FIGS. 20 a - c show the crest length of teeth and tooth locations on all three cones before and after optimization. FIGS. 22 a illustrates the definition of a positive tooth orientation angle 2210 and a negative tooth orientation angle 2211 . FIGS. 22 b lists the orientation angles used for the three cones in energy-balanced bit 1810 .
[0214] According to a disclosed class of innovative embodiments, there is provided: A method of designing roller-cone drill bits, comprising the actions of: a) simulating operation of a drill bit having multiple design parameters; b) adjusting said multiple bit design parameters by reference to a multi-objective optimization which combines objectives related to maximizing rock removal of subelements, objectives related to equalization of rock removal among groups of said subelements, and also objectives related to minimization of one or more shock loading components; and c) after one or more iterations of said steps a) and b), outputting the results of said step b).
[0215] According to another disclosed class of innovative embodiments, there is provided: A method of designing roller-cone drill bits, comprising the actions of: adjusting multiple bit design parameters by reference to a multi-objective optimization which combines objectives related to maximizing rock removal of subelements, objectives related to equalization of rock removal among groups of said subelements, and also objectives related to minimization of one or more shock loading components.
[0216] According to another disclosed class of innovative embodiments, there is provided: A method of designing roller-cone drill bits, comprising the actions of: a) simulating operation of a drill bit having multiple design parameters; b) adjusting multiple bit design parameters by reference to a multi-objective optimization which combines objectives related to maximizing rock removal of subelements, objectives related to equalization of rock removal among groups of said subelements, and also anti-tracking objectives; and c) after one or more iterations of said steps a) and b), outputting the results of said step b).
[0217] According to another disclosed class of innovative embodiments, there is provided: A method of designing roller-cone drill bits, comprising the actions of: adjusting multiple bit design parameters by reference to a multi-objective optimization which combines objectives related to maximizing rock removal of subelements, objectives related to equalization of rock removal among groups of said subelements, and also anti-tracking objectives.
[0218] According to another disclosed class of innovative embodiments, there is provided: An algorithm for optimizing a roller-cone bit, comprising the actions of: reading the initial information on the bit to be optimized, the formation to be drilled, and the operational parameters; defining the optimization objectives based on the bit size and type; simulating the operation of the drill bit having the operational design parameters through the formation to be drilled; outputting the forces on the teeth, cones, and bit; bit-balanced conditions; and bottom hole pattern; defining design variables and their bounds; generating linear and nonlinear constraints on the design variables; calling a simplified two-dimensional bit/formation interaction model; scaling said two-dimensional results using the initial three-dimensional results; determining optimized bit parameters using said scaled results; and redesigning said bit using the optimized bit parameters.
[0219] Modifications and Variations
[0220] As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a tremendous range of applications, and accordingly the scope of patented subject matter is not limited by any of the specific exemplary teachings given.
[0221] For example, the various teachings can optionally be adapted to two-cone or four-cone bits.
[0222] In one contemplated class of alternative embodiments, the orientations of teeth can be perturbed about the optimal value, to induce variation between the gage rows of different cones (or within an inner row of a single cone), to provide some additional resistance to tracking.
[0223] Of course, the bit will also normally contain many other features besides those emphasized here, such as gage buttons, wear pads, lubrication reservoirs, etc.
[0224] Additional general background, which helps to show the knowledge of those skilled in the art regarding implementations and the predictability of variations, may be found in the following publications, all of which are hereby incorporated by reference: APPLIED DRILLING ENGINEERING, Adam T. Bourgoyne Jr. et al., Society of Petroleum Engineers Textbook series (1991), OIL AND GAS FIELD DEVELOPMENT TECHNIQUES: DRILLING, J.-P. Nguyen (translation 1996, from French original 1993), MAKING HOLE (1983) and DRILLING MUD (1984), both part of the Rotary Drilling Series, edited by Charles Kirkley, VECTOR OPTIMIZATION FOR CONTROL WITH PERFORMANCE AND PARAMETER SENSITIVITY INDICES, F. W. Gembicki, Ph.D thesis, Case Western Reserve Uni., Cleveland, Ohio, (1974), and COMPUTER-AIDED CONTROL SYSTEM DESIGN USING OPTIMIZATION TECHNIQUES, A. C. W. Grace, Ph.D thesis, University of Wales, UK (1989).
[0225] None of the description in the present application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope: THE SCOPE OF PATENTED SUBJECT MATTER IS DEFINED ONLY BY THE ALLOWED CLAIMS. Moreover, none of these claims are intended to invoke paragraph six of 35 USC section 112 unless the exact words “means for” are followed by a participle. | The present application describes techniques for optimization of drill bit designs using multiple objectives. Multi-objective optimization permits various factors to be taken into account in a balanced way, without having to decide which factor is most important, or which factors will be dependent on each other. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of pending U.S. patent application Ser. No. 07/771,452, filed 10/3/91 entitled "Automatic Shutoff Valve" and incorporated herein by reference.
BACKGROUND OF INVENTION
1. Field of the Invention
This invention relates to a low friction ball valve.
2. Description of the Prior Art
Ball and plug valves are both well known. However, problematically such valves require high rotational forces needed to change the fluid flow condition from ON to OFF or vice versa (i.e., to operate the valve). This is due to the friction between the valve ball and the valve seals. Lubricating the seals is also problematic since the lubricants lose their effect with age. Thus, there is a need for a low friction valve that does not require lubrication.
SUMMARY OF THE INVENTION
A spring-loaded ball valve is normally latched in an open condition thus allowing unimpeded fluid flow. The ball inside the valve rotates so that in the open position a collar on the ball surface is in contact with two rollers fixed in the valve body, and the ball is held away from a seal in the valve body. When the valve ball is rotated 90° to be closed, the rollers snap into detents in the ball surface, and this lets the ball come into firm contact with the seal.
The valve latch mechanism holds the valve in the open condition until it is unlatched (in one version) through the action of a BioMetal™ wire which contracts in length when heated by the passage of electrical current through the wire. Unlatching the latch mechanism allows a torsion spring to apply sufficient torque to the ball portion of the valve to rotate it 90 degrees to the closed position thus shutting off flow. The valve may also be operated manually or by other mechanical or electro-mechanical means. The ball valve allows rotation with minimal friction until the closed position is reached, at which time the ball firmly seats against the sealing O-ring.
DESCRIPTION OF THE DRAWINGS
FIG. 1A is a cross-sectional view of a ball valve.
FIG. 1B is a top view of the ball valve with cutaway views.
FIG. 1C is a side view of the ball valve to illustrate the latch mechanism.
FIG. 1D is a side view of the ball valve with the spring and latch mechanisms removed to provide manual on/off operations.
DETAILED DESCRIPTION
FIG. 1A is a cross-sectional view of the water shutoff valve 1. Valve 1 is a spring-loaded ball valve which permits changing its flow status from ON to OFF or vice versa by rotating the ball through 90 degrees. The valve is shown in a closed condition with valve ball 36 pressing against the O-ring seal 39, thus preventing fluid flow through the pipe fitting and input port 3 to the pipe fitting and output port 2. Through-hole 37 in valve ball 36 provides the path for fluid flow when the valve ball 36 is rotated 90 degrees.
One major problem encountered in prior art ball valves or plug valves pertains to the high rotational forces required to change the fluid flow condition from ON to OFF or vice versa. The high rotational forces are primarily due to the friction between the valve ball and the O-ring seals. This friction becomes more pronounced as the lubricants, normally applied during valve manufacturing, become sticky or hard as they age.
To minimize these friction forces, in accordance with the invention, a novel ball rotation system is used which allows the valve ball 36 to rotate with a small clearance or very slight contact between itself and the O-rings 38 and 39 when in the valve open condition, to prevent contamination particles from entering the valve mechanism. Rollers 40 and 42 which rotate on pins 41 and 43 respectively reduce friction. Roller 40 normally rides on the upper collar surface 56 of valve ball 36 during the open valve portion of rotation. Likewise, roller 42 rides on the lower collar surface 54. In this valve open condition the valve ball lightly touches the O-rings 38 and 39 as previously stated.
The valve-closed condition is more easily understood by the insert view 57 of FIG. IA. In this view the top portion of the valve ball is shown rotated to produce a top view of the valve ball 36. While this inserted view shows the top of valve ball 36 and roller 40, it should be understood that a bottom view would similarly show the valve ball collar 54 and associated roller 42. Again referring to the insert view 57, observe that, in the position shown, roller 40 is resting in detent 53 of the valve ball collar 56 and, while not shown, bottom roller 42 rests in detent 58. This allows the surface of valve ball 36 to press against O-ring 39 due to the resulting inlet water pressure. Although not shown, spring pressure could be provided to ensure ball valve 36 closure against O-ring 39 in the event of low water pressure. This could be accomplished using spring-loaded rollers, or the equivalent, pressing against the water inlet side of valve ball collars 56 and 54. Also note that to allow valve ball 36 to move in a +X direction, the bottom, rectangular end of shaft 44 fits into rectangular slot 51.
To reset the valve to an open condition, knob 5 must be rotated in a clockwise direction as viewed from the top of valve 1. Shaft 44 couples the rotational torque from knob 5 to valve ball 36. O-ring 45 seals against fluid leakage. Once again referring to insert view 57 it can be seen that a clockwise rotation of valve ball 36 causes the outer diameter of upper collar 56 to engage roller 40 in a manner which produces a movement of valve ball 36 in a -X direction. The outer diameter of lower collar 54 likewise engages roller 42. Once knob 5, shaft 44, rotor 47, and valve ball 36 are rotated 90 degrees to a latched, valve open position there is little if any frictional contact between the valve ball 36 surface and O-ring 39.
Bottom cover 49 provides access to the inner cavity of valve body 48 to facilitate assembly. O-ring 59 seals against fluid leakage. Top cover 50 encloses the rotor 47. The valve may be made from materials such as polycarbonate with the valve components being injection molded, or from other plastics, or from metal.
FIG. 1B is a top view of water shutoff valve 1 showing cutaway views of the rotor 47 and torsion spring 46 locations. Rotor 47 is now shown in a position representing a valve-open condition. The inner coil of torsion spring 46 is shown attached to the hub portion of valve body 48. The outer spring coil is attached to the rotor 47 using a hook arrangement at point 55. Spring 46 is now exerting a counterclockwise torque on rotor 47. The rotor is now locked in a valve-open position by the valve latching mechanism to be described later. When the valve latching mechanism releases the rotor 47 to rotate in a counterclockwise direction in order to establish a valve-closed condition, the amount of rotation is restricted to 90 degrees when rotor surface 61 hits the stop pin 60. Because rotor 47 is physically attached to shaft 44 the valve ball 36 will likewise be placed in a valve-closed condition as previously described in conjunction with FIG. 1A.
FIG. 1C shows a cutaway view of the latch mechanism used in one version to hold the valve in an open condition until a valve closure is required. Latching arm 62 engages rotor 47 at surface 47a in order to prevent any rotor movement. Latching arm 62 is pinned at point 74 and would normally rotate in a clockwise direction about that point due to the rotational moment impressed on the latching arm by rotor 47. However, the end of latching arm 62 contacts the lip of trip arm 64 in a manner which does not permit any rotation of the latching arm. Trip arm 64 rotates about point 75 and it receives a counterclockwise retaining torque from wire spring 65 which also holds trip wire 66 in a taut condition.
Trip wire 66 is a special shape memory alloy, metallic wire marketed under the name BioMetal™ by Mondotronics, Inc., Sunnyvale, Calif., which has the property of contracting in length when heated to a specific temperature. The method of heating involves passing an electrical current, on the order of 400 milliamperes, through the wire. Trip wire 66 is fastened at one end to mounting terminal 67 which, in turn, is fastened to printed circuit board 70. The other end of the trip wire is fastened to the bottom of trip arm 64 with a short extension to terminal 72 which provides a necessary electrical connection to printed circuit board 70.
To initiate a valve-closed condition the following chain of events takes place. First, the necessary drive signal from a control module (not shown) produces a heating current in trip wire 66, thus causing it to contract in length. The resulting force on the lower end of trip arm 64 causes the trip arm to rotate in a clockwise direction about point 75. The top end of trip arm 64 now moves a sufficient distance to release the end of latch arm 62. Latch arm 62 now rotates in a clockwise direction under the pressure of the rotor 47 which easily overcomes the retaining torque of wire spring 63. As rotor 47 rotates toward a valve-closed condition, the tip of latch arm 62 rides in contact with surface 47b. Once the rotor 47, and hence the valve ball 36 have rotated to a valve-closed condition, the tip of latch arm 62 rides in contact with surface 47c. At this position, point 62a of latch arm 62 contacts leaf-spring switch 68 causing its electrical contact to separate from the circuit board mounted contact 69. Had a mechanical malfunction occurred which might cause the valve to jam before it could reach a fully closed condition, the tip of latch arm 62 would not reach the surface 47c and switch 68, 69 contacts would not open, which in turn in one version will cause the associated microcontroller to produce an urgent attention alarm to alert people that a malfunction has occurred. It should also be noted that connector 71 is mounted to printed circuit board 70 to provide the necessary signal routing and interconnection for electrical cables 6, 16, and 4.
FIG. 1D shows a second version of shutoff valve 1 without the above-described spring and latch mechanisms, resulting in a simple, manually or electro-mechanically controlled ball valve having the low friction capabilities described in connection with FIG. 1A. The elements removed to provide the above valve configuration include spring 46, rotor 47, and top cover 50 shown in FIG. 1A, and latch arm 62, spring 63, along with printed circuit board 70 and all associated items mounted on or attached to the circuit board as shown in FIG. 1C.
The second version of the valve body is now shown as element 156. It can now be seen that rotation of the knob 5 through 90 degrees rotation, either manually or by other means, will cause the amount of flow of liquid or gas through the valve to vary from full, unrestricted flow to zero flow. This provides low rotational torque during approximately 80 degrees of valve ball rotation until rollers 40 and 42 engage the detents 53 and 58 (as previously described) at near to 90 degrees, at which position the valve is in a full off (closed) condition.
The primary advantage in using a latched valve is that it requires no holding power once it has been tripped to a closed position. Another advantage is that it requires no fluid flow through the valve or pressure differential across the valve to activate its closure mechanism, as is the case with certain hydraulically or pneumatically activated valves. It should also be recognized that, although the described valve utilizes a BioMetal™ wire to activate the unlatching mechanism, a device such as a solenoid could also be used. In addition, a manual means of activating the unlatching mechanism could be used.
The description of the invention herein is illustrative and not limiting; further modifications will be apparent to one skilled in the art, in the light of this disclosure and are included in the scope of the appended claims. | A low friction ball valve used for instance in an automatic shutoff valve system. The valve mechanism includes a spring loaded ball valve normally latched in the open position which is unlatched and hence closes in one version by the contraction of a BioMetal™ wire which activates a torsion spring to rotate the ball valve. When the valve is open, the ball inside the valve rests on rollers so that the ball is held slightly away from the seal of the valve located in the valve body. Closing the valve causes the rollers to snap into detents in the ball, and the ball then comes into firm contact with the seal. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to electrodes for sensing or stimulating or both, and more particularly the present invention relates to electrodes and sensors carried on a flexible substrate. Still more particularly the present invention relates to respiration sensor technology for detecting abnormal breathing of a client.
2. Description of the Prior Art
It is known in the prior art to employ respiration sensors to monitor patients' susceptible to sleep apnea and other disorders of the respiration system. U.S. Pat. No. 4,878,502 discusses a breathing sensor employing a tubular passage in which a ball is free to move to break a beam of light. The ball is moved in response to the flow of air associated with the breathing of a patient. An optoelectric inhalation sensor using thin film deposition is disclosed in U.S. Pat. No. 4,745,925.
Acoustic sensors for monitoring respiration are mentioned in U.S. Pat. Nos. 4,602,664 and 4,595,016. U.S. Pat. No. 4,366,821 shows a respiration monitoring system that preferably uses a gas sensor, and U.S. Pat. No. 4,350,166 discloses the use of a video monitor. U.S. Pat. No. 4,326,404 discloses the use of a sodium chloride crystal to sense moisture.
A pressure sensor for respiration monitoring is taught in U.S. Pat. No. 4,306,867. U.S. Pat. No. 4,289,142 teaches the use of an impedance plethysmograph for respiration sensing. The use of thermoresistive sensors for monitoring is suggested in U.S. Pat. Nos. 3,903,876; 3,884,219; and 3,999,537.
The advantages of providing multiple sensors on a single flexible substrate are taught in U.S. patent application Ser. No. 08/182,424, filed Jan. 18, 1994 by Bowman et al. This Bowman et al Application discusses employing a plurality of sensor electrodes positioned at the various orifices which vent the upper airway of a patient; normally the two nostrils and the mouth.
A continuing disadvantage with this and other prior art which employs flexible substrates is that when the substrate is flexed, the resulting pressure on the sensor electrodes causes changes in their electrical and thermoresistive specifications.
SUMMARY OF THE INVENTION
The present invention-overcomes the disadvantages found in the prior art by providing, for each sensor electrode mounted on the sensing surface of the substrate, at least one further essentially similar electrode mounted on the opposite side of the substrate and electrically connected to its related sensing electrode. As the substrate is flexed the result is to bend the sensor and its similar electrode in opposite directions such that the resistive change in the electrode under compression is counteracted by the resistive change in the electrode under tension.
Another advantage of the present invention is found when the cause of the change is the breath of a patient impinging on the thermoresistive sensing electrode. The related electrode will receive the residual heat caused by the airflow to the opposite side of the substrate and thus the overall change in resistance will be increased due to the electrodes on both sides of the substrate being electrically connected, for example, in series.
Though the advantages of connecting an electrode on one side of a flexible substrate with a substantially identical mate electrode on the opposite side of the substrate have been described above with reference to the improved respiration sensor of this invention, it will be apparent to one of skill in the art that there are other valuable uses for this unique combination of elements and the method of manufacturing them. For example, the above described combination of electrodes could be used for stimulating portions of a patient's body, and the correction of electrical pressure changes would advantageously effect the stimulation by keeping the overall resistance of the stimulating electrode more stable.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein:
FIG. 1 is an exemplary plan view showing a portion of a flexible substrate with mated pairs of essentially similar electrodes mounted on opposite sides of the substrate;
FIG. 2a is an plan view of the upper surface of the substrate of FIG. 1;
FIG. 2b is a plan view of the lower surface of the substrate of FIG. 1;
FIG. 3 is a perspective sectional view taken along section line 3--3 of FIG. 2a;
FIG. 4 is a partial plan view of a first surface of a flexible substrate in a respiration sensor utilizing the apparatus of this invention; and
FIG. 5 is a partial plan view of a second surface of the respiration sensor of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As will be apparent from the following discussion, FIGS. 1-3 are intended to be exemplary or representative of the general apparatus of this invention. FIGS. 4 and 5 disclose a preferred embodiment of this invention as used in a respiration or airflow sensor.
FIG. 1 shows a portion of a flexible substrate 11. Mounted on a first side of substrate 11 are a plurality of resistor elements 12, 13 and 14. Mounted on the opposite side of substrate 11 are another plurality of substantially identical resistor elements 22, 23 and 24. It is important to note that though this preferred embodiment of the apparatus of this invention uses a plurality of pairs or mates of resistors the invention will be effective even with one pair of resistor elements.
FIG. 2a shows a top or upper side view of substrate 11, which is here shown as having a connector tab 15 adapted to be joined to an electrical connector (not shown). Resistor elements 12, 13 and 14 are electrically connected to tab 15 through, respectively, electrical path pairs 16, 17 and 18.
FIG. 2b shows a bottom or lower side view of substrate 11 and connector tab 15. Resistor elements 22, 23 and 24 are electrically connected to tab 15 through, respectively, electrical path pairs 26, 27 and 28. It is apparent that the bottom view of substrate 11 as shown in FIG. 2b is essentially a mirror image of the top view of substrate 11 shown in FIG. 2a. Each mated pair of resistors, 12 and 22, 13 and 23, and 14 and 24 preferably comprise substantially identical resistors. In the preferred embodiment, all of the resistor elements have a resistance value that fluctuates or changes with pressure variations, and each of the resistor elements may be thermoresistive such that its electrical value may also change with temperature variations. Further, in the preferred embodiment the joinder of connector tab 15 to a connector (not shown) results in the electrical connection of each of resistors 12, 13 and 14 in parallel with its mated resistor, 22, 23 or 24.
FIG. 3 shows a perspective sectional view of substrate 11 with connector tab 15, the section taken along section line 3--3 of FIG. 2a. It again becomes apparent how mated pairs of resistors 12 and 22, 13 and 23, and 14 and 24 are mounted on opposing sides of substrate 11. Also shown are electrical path pairs 16, 17 and 18 connecting resistors 12, 13 and 14, respectively, to tab 15. (Electrical path pairs 26, 27 and 28 are present but only partially visible in FIG. 3 for the purpose of connecting, respectively, resistors 22, 23 and 24 to tab 15, as is clearly shown in FIG. 2b.)
From FIGS. 1-3 it is apparent that as substrate or base 11 is flexed each mated pair of resistors will flex in opposite directions to one another. For example, if resistor 12 is placed under compression, its paired resistor 22 will be placed under tension. As a result, because the pair of resistors are connected in parallel, the opposite changes in resistance values of the two resistor elements should be essentially off-setting. Thus the apparatus and the method of connection of this invention creates a substantially stable electrical resistance on the flexible substrate to reduce or remove disadvantages of the prior art caused by unavoidable resistance changes due to flexing of the base or substrate holding the resisters. This advantage prevails no matter what the device may be which utilizes the invention, as long as the device requires a flexible base on which are mounted one or more resistance elements that will flex when the base flexes.
Another use for the apparatus and method of FIGS. 1-3 is as a temperature sensor. For example, if resistors 12, 13 and 14 are of a thermoresistive material, such as carbon, and are situated directly in an air flow path, such as under the nostrils of a patient, the flow of air impinging on the resistors will cause a temperature change and thus alter the resistance value of each resistor. With the addition of the substantially similar mating resistors, 22, 23 and 24, a certain amount of residual air flow will reach around substrate 11 to impinge upon and change the resistance value of these added resistors as well. Because each of elements 22, 23 and 24 is connected to its respective mate 12, 13 or 14 through connector tab 15, the additional sensing of the air flow will increase the reliability and sensitivity of the sensing device.
It will be apparent that though using a plurality of resistors on each side of the flexible base has been described as preferred, the use of a single resistor with one mate will also fall within the scope of this invention and offer similar advantages over the prior art.
For the preferred embodiments of FIGS. 1-3 described above, flexible base or substrate 11 may be any one of a plurality of such apparatus well known and widely used in the art. Resistor or sensing elements 12-14 and 22-24 may be produced using several known technologies. In the preferred embodiments, a conductive ink having a high temperature coefficient of resistance and high resistance may be applied to a first side of base 11 using a silk screening process; thus producing resistor elements 12-14. Mating elements on the other side of base 11 may be produced in a similar manner to create mating resistor elements 22-24. Conductive paths 16-18 and 26-28 may preferably comprise a conductive ink having a low resistance and a low temperature coefficient of resistance. Normally the interconnecting electrical paths are silk screened on their respective side of base or substrate 11 in a separate step from the printing of the resistance or sensing elements.
Though each mated pair of resistors is preferably connected in parallel, it is apparent that each mated pair of resistors could be connected in series and still offer the same advantages over the prior art. Further, each of the parallel-connected mated pairs on either side of the substrate are preferably connected in series with one another, though it is apparent that they could as well be connected in parallel without departing from the scope and advantages of the present invention.
Referring now to FIG. 4, there is shown a partial plan view of a respiratory air flow sensor utilizing the apparatus and method of this invention. A first surface of a substrate 111 is shown having a pair of projections 42 and 43 on which are printed a set of carbon bars 112 and 113, respectively. Conductive ink bars 112 and 113 are carbon-based to give them a relatively high resistance and a relatively high temperature coefficient of resistance.
A connector tab 115 is shown having a set of connector bars 46 and 47 mounted thereon, and a silver conductive ink is printed on substrate 11 to print electrical conductive paths 116 and 117 that connect bars 112 and 113 in series to tab 115 and connector bars 46 and 47.
FIG. 5 shows the opposite surface of substrate 111 and projections 42 and 43 on which are printed another set of carbon-based conductive ink bars 122 and 123 that are substantially identical to bars 112 and 113 of FIG. 4. A set of connector bars 48 and 49 are printed on the opposite side of connector tab 115, and silver conductive ink is again used to print electrical conductive paths 126 and 127 that connect bars 122 and 123 in series to tab 115 and connector bars 46 and 47.
When tab 115 is joined to its connector (not shown), the electrical path including bars 112 and 113 is mated in parallel with the electrical path including bars 122 and 123. The mated paths may be connected in series rather than parallel if desired. Power is also applied at the time of connection of tab 115 to its connector.
When the sensor of FIGS. 4 and 5 is applied to a patient projections 42 and 43 are situated under the nostrils such that warm air is expelled directly onto carbon bars 112 and 113 on the patient side of base 111 to warm bars 112 and 113 and cause a change in their resistance. Bars 122 and 123 on the opposite side of base 111 will be exposed to the warmth of residual amounts of expired air and will also have a change in resistance. Because of the electrical connection between mating pairs of bars 112 and 123, as well as 113 and 123, the warm air flow from the patient's nostrils will be sensed with a greater sensitivity and more reliability than in prior art devices.
Further, as more fully described above in the discussion of FIGS. 1-3, when projections 42 and 43 are flexed, the resultant resistance drop in the bar under compression will be counteracted by the mating bar under tension, thus making the overall resistance change essentially zero. Having thus described the preferred embodiments of the present invention, those of skill in the art will readily appreciate the other useful embodiments within the scope of the attached claims. | An apparatus and method for electrically stable electrodes and sensors having a flexible base or substrate. One or more flexible and pressure sensitive resistors having a high resistance and a high temperature coefficient of resistivity are printed on a first surface of the flexible base, and a second set of one or more substantially identical resistors are printed on a second surface such that each resistor on the second surface is directly opposite a resistor on the first surface. The opposing resistors are then electrically interconnected in mating pairs, so that when the substrate is flexed, one resistor of each pair is compressed and the other is tensed with the result that the changes in resistance cancel one another. | 0 |
BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to noise abatement apparatus and a method of reducing noise levels and, more particularly, to a noise abatement apparatus and method for yarn treating machines which texture yarn at high production speeds.
It is well known that in many industrial operations workers are exposed to dangerously high noise levels which, over a period of time, can result in hearing impairment. It has also been known that worker productivity is adversely affected where the working conditions involve exposure to high levels of noise. As a result, various industrial and governmental bodies have proposed and enacted regulations and guidelines which require businesses to modify the production environments of their employees by reducing the sound levels to which the employees are exposed.
As a result of these regulations, resort has been had to the use of individually worn ear protectors or the use of sound baffles around various types of machinery.
The former solution has been found impractical due to the resistance of workers to consistently employing the ear protectors, and, since it is impractical to monitor machine operators to ascertain whether or not they are properly wearing ear protectors, of necessity, noise abatement techniques have been directed to installing various types of sound baffles around noise generating sources.
In a number of arrangements, it has been proposed to surround either the entire machine with a sound baffle or enclosure, or to mount sound absorbing panels on the machine to enclose the device which is the greatest sound generating source.
The technique of completely enclosing a piece of machinery, however, is practical only where the machinery is relatively cool running, i.e., non-heat generating, which is such a rare occurrence as to render this procedure of extremely limited utility.
The other proposed techniques of enclosing all or at least most of the principal noise generating sources of a machine have suffered from the disadvantages that such procedures encumber the use and operation of the machines by restricting access to the portions of the machines that require operator attention as well as contribute to heat build-up in the enclosed parts, thus requiring compensating and expensive cooling devices. Such cooling devices appreciably increase the cost of installing the sound insulating equipment which itself is an expensive undertaking, but which, nevertheless, is rendered necessary in the interest of preventing hearing impairment as well as augmenting productivity.
The following references are representative of the prior art:
3,393,765 3,747,735
3,604,531 3,782,087
3,633,706 3,860,086
3,695,386 3,866,708
3,700,068 3,867,875
3,713,509
The present invention provides solutions to the foregoing problems without encountering the drawbacks of the prior art arrangements by concentrating its improvements on a specific type of noise generating machinery, i.e., a false twist texturing machine, whereby a satisfactory noise reduction is achieved by substantially fewer modifications to the machine than would be the case where the prior are techniques are employed.
Specifically, the present invention is directed to noise abatement in connection with a false twist texturing machine of the type that is provided with a number of yarn texturing positions each of which is provided with yarn feeding means for drawing yarn from a take-up package through a heater and false twist spindle and then delivering the yarn to a yarn take-up package.
Noise abatement techniques as applied to false twist machines, it has been found, must take into consideration certain operational aspects of these machines, such as the fact that large quantities of heat are continuously generated by the heaters of the machines which must be dissipated so that the working environment may be maintained at a tolerable level. Additionally, access to the supply packages, heater, spindle and take-up packages must be continually provided for observation by an operator, so that any yarn breakages which frequently occur in these machines can be promptly rectified so as to minimize production losses and to avoid expensive fouling of the machine. As will be appreciated by those skilled in the art of texturing, presently operated false twist machines run at enormously high speeds corresponding to a yarn velocity through the machine on the order of 400 yards per minute, on the average. As a result, the noise generated by the moving parts of these machines are presently manufactured, can result in hearing impairment for an individual who is exposed to machines on a day-to-day basis.
According to the present invention, it has been found that substantially few modifications to a false twist texturing machine need be effected in order to bring the noise level of the machine operating at capacity within tolerable limits. Also, the cost of the modifications that are effected is substantially lower than that which would be the case if the total enclosure procedures were followed so that the present invention provides the economic incentive necessary to encourage manufacturers to adopt the sound suppressing method as described herein.
Specifically, it has been found that a significant noise level reduction can be achieved in yarn texturing machines where a number of relatively simple modifications to the machine are made. Specifically, according to the present invention, noise generated by tape pulleys is eliminated by appropriate modification of the pulleys and by enclosing in a suitably muffled enclosure the head end tape pulley. Additionally, tunnels are provided for the drive belt of the tape pulleys at a specific location with the tunnels being lined with sound absorption material so that noise generated within the gear housing will be attenuated in the tunnels. Also, the idler pulleys which are driven by the drive belt are provided with vibration isolation mountings and sleeves, the latter serving both to increase the diameter of the pulleys and thus reduce their rotational speed and to provide a dissimilar outer metal casing which will serve as a sound impedance barrier and frictional damper.
Also, according to the invention, all unnecessary openings in the gear housing are closed with panels which are mounted on the interior or exterior of the housing. Also, the inside surfaces of the gear housing should be lined with a sound absorption material.
Preferably, the conventional plastic sheet protectors that are provided with a conventional false twist machine as a protection for an operator and which are located adjacent the spindles can also be lined with a suitable sound adsorption material and these deflectors should be repositioned as closely as possible to the spindle heads.
Additional noise suppressing procedures, which are described in detail in the following description, will contribute to the overall noise reduction when combined with the foregoing procedures and devices, whereby the possibility of hearing impairment will be substantially reduced since the noise levels will be suppressed at the source as opposed to during their transmission or at the receiver. Thus, the necessity of enclosing the production portions of the machine, together with the attendant problems as a result of heat build-up are avoided, while the machine attendants will no longer be encumbered by earplugs or ear muffs, which can be a source of danger particularly in the event of an emergency in a plant.
The foregoing and other advantages will become apparent as consideration is given to the following detailed description and accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a single heater false twist texturing machine;
FIG. 2 is a perspective view with parts broken away of the spindle drive mechanism of the machine of FIG. 1;
FIG. 3 is an enlarged view of an idler pulley carried on the spindle drive mechanism;
FIG. 4 is a perspective view with parts broken away of the head end tape pulley;
FIG. 5 is a view in elevation with parts broken away of the pulley of FIG. 3;
FIG. 6 is a view in elevation, partly in section, of a tape pulley;
FIGS. 7A, 7B and 7C are top plan, side and front elevational views, respectively, illustrating the enclosure for the head end tape pulley; and
FIG. 8 is a perspective view with parts broken away of the gear housing showing the mounting relation of the head end tape pulley and sound insulation panels with respect thereto.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is illustrated a perspective view of a false twist texturing machine 10, the operation of which is conventional and widely understood in the textile industry. In brief, a texturing machine such as the Leesona 553 machine consists of a gear housing 12 at one end of the machine and a motor housing 14 at the other end of the machine. A frame such as at 16 extends between the housings 12 and 14 and supports a number of yarn texturing positions. Each yarn texturing position conventionally includes one or more supports for yarn supply packages such as at 18, a contact heater 20, a false twist spindle 22 and yarn take-up packages such as at 24 and 26. Suitable yarn drawoff and tensioning mechanisms (not shown) are also incorporated on these machines to pull yarn off the supply packages 18 over and in contact with the heater 20, through the false twist spindle and then to the take-up package 24.
With the false twist spindles 22 operating at extremely high speeds, for example, on the order of 300,000 to 500,000 rpm, the velocity with which yarn travels through the machine from the supply package 18 to the yarn take-up 24, must be correspondingly high, such as on the order of 400 to 500 yards per minute.
As in many conventional texturing machines, a single electric motor is employed as the source of power so that relatively complex gearing installations must be employed to distribute the power at the appropriate speeds to the various mechanisms of the machine. In the Leesona 553 machine, as noted above, the motor is located in housing 14 whereas the principal gearing mechanisms are located in housing 12. From the motor in housing 14, rotary power is transmitted to the gear housing 12 by any suitable means such as a drive shaft or belt connection to the gears. From the gear housing 12, a number of drive shafts extend for operating the yarn feeding devices (not shown) which draw the yarn from the supply packages 18, as well as rotary shafts for operating the lower and upper feed rolls (not shown) and the usual traverse units and take-up devices 24. Also, from the gear housing 12, a spindle drive belt extends along the frame 16 for driving the spindle mechanisms disposed on the spindle rail 28, which is illustrated in more detail in FIG. 2.
There is illustrated in FIG. 2 a segment of the spindle rail 28 which comprises, in general, an elongated platform 30, which extends from one end of the machine to the other, and is supported at each end and at intermediate intervals by bridges 32, which are secured to supports by rods fixed in bores, one of which is illustrated at 34.
Spaced along the platform 30 of spindle rail 28 are a plurality of tape pulleys indicated in dotted lines at 36, and rotatably mounted on the platform 30. As will be described in detail hereinafter, the tape pulleys 36 are driven by a drive belt and in turn the pulleys rotate a spindle tape which is, in turn, in driving engagement with the false twist spindles which are positioned in the apertures 38 of a cover 40, which extends the length of the frame 16.
Mounted on the side of the platform 30 is a plexiglas deflector 42, which preferably is positioned at the level of the false twist spindles to protect persons working about the machine from injury due to parts flying out of the spindle in the event a spindle is damaged during use. According to the present invention the inner side of the deflector 42 is lined with a sound absorbing material as at 44, which may be a polyurethane foam pad provided with a self-adhesive coating on one side. Preferably, the deflector 42 is supported by a plurality of hooked brackets as at 46, which are secured to the side edge of the platform 30.
Adjacent the gear housing 12, there is located a head end tape pulley 50 which is illustrated in FIG. 4. The pulley 50 is mounted on a slidable plate (not shown) since this pulley is connected to the power source through a timing belt 52, which engages a drive on the under side of the pulley 50. The timing belt, in turn, is driven by a pulley located in the housing 12 which also is in driving engagement with an endless drive belt 54, which extends along the length of the frame 16 and is in driving engagement with whorls 99 (FIG. 6) of each of the tape pulleys 36. The tension on the drive belt 54 is regulated in part by the positioning against the belt 54 of a number of idler pulleys 56, the construction and mounting of which will be described hereinafter in more detail.
It has been found that a large portion of the noise level of the texturing machine has its source in the gear housing 12 with respect to the drive mechanisms for the spindle tape 58, which is driven by the tape pulleys 50 and 36. Specifically, it has been found that the timing belt 52, while operating, contributes significantly to the noise level. According to the present invention, then, an enclosure for the end pulley 50 is provided which consists of a sound insulated enclosure 60, which is located between the cover 40 and the platform 30 of the spindle rail. The exterior dimensions of the enclosure 60 are, of course, shaped to close the space between the cover 40 and the platform 30. In addition, the width or thickness of the enclosure 60 should be selected to sufficiently attenuate the noises associated with the operation of the pulley 50 and timing belt 52. To this end, enclosure 60 is provided with tunnels as at 62, which are lined with sound absorption material 64, which may be a polyurethane foam, or other suitable sound absorbing material. The upper surface 66 of the enclosure 60 should be shaped to closely interfit with the undersurface of the cover 40, as illustrated.
More detailed illustrations of the enclosure 60 are shown in FIGS. 7A, 7B, and 7C. In FIG. 7A a top view of the enclosure 60 is depicted showing the orientation of the tunnels 62 and the relative dispositions of the sound insulation 64, on the interior of the enclosure 60.
The wall portions of enclosure 60 may be made from a single piece of sheet metal that is bent into the illustrated configuration to form the top wall 66 and the side walls 68. The wall portions 70 which extend from the rear edges of the side walls 68 are provided with cut-out sections 72 through which the spindle tape 58 passes.
Preferably, the polyurethane foam sections 64 are provided with self-adhesive coatings to facilitate their adherence to the interior walls of the enclosure 60.
Other troublesome sources of noise in the spindle drive mechanism of the texturing machine are the idler pulleys 56 which are disposed in pairs along the platform 30. As illustrated in FIGS. 3, 4 and 5, each pulley 56 is mounted on a flange rail 74, which extends upwardly from the platform 30, on either side of the path of travel of the drive belt 54.
As shown in FIGS. 3 and 5, each idler pulley is mounted on an adjustable stand 76. To this stand, according to the present invention, is attached a spacer bar 79, welded to a pair of L-shaped members 78, said members engaging the top of the flange rail 74. Isolation pads 80, which may be of rubber, are interposed between the L-shaped members 78 and the top of the rail 74.
The rail 74 is provided with apertures 82 for receiving mounting bolts 84, which are isolated from the rail by tubular Teflon bushings 77. A nut 86 is screwed on to bolt 84 to hold a plate member 88 in tightened engagement with another isolation pad 90, which is interposed between the plate 88 and the flange rail 74. Similarly, an isolation pad 92 is disposed between the spacer bar 79 and the other side of the flange rail 74. With the foregoing arrangement, the mounting of the pulleys 56 on the flange rail 74 can be securely effected in a manner that will substantially eliminate any structural vibration path from the pulley to the mounting rail during the operation of the texturing machine.
In addition, it has been found that the pulleys 56 when rotated at high speed emit a high frequency noise due to resonant vibration. According to the present invention, the generation of this high frequency noise is substantially reduced by the provision of a sleeve 94 which is constructed from a metal that is dissimilar with respect to the metal of the pulley 56. Specifically, where the body 96 of the pulley is of steel alloy, the sleeve 94 should be aluminum, which is press-fitted about the circumference of the body 96. As a result of the increase in the diameter of the pulley 56 by the provision of the sleeve 94, the pulley 56 will rotate at a lower rotational velocity when in use, thus further contributing to a reduction in noise level from this source.
As illustrated in FIG. 6, it has been discovered that another noise source that can be relatively easily suppressed is found in the balancing holes 98, which are formed in the underside of the tape pulleys 36. According to the present invention, the high frequency noise, which is emitted when the pulleys 36 are rotated at high speeds, can be entirely eliminated by simply cementing or otherwise securely adhering a thin plastic disc or annulus 100 so as to completely cover the balancing holes 98 for each of the tape pulleys. Thus, with this relatively inexpensive modification, a source of high frequency noise is eliminated.
In the Lessona 553 machine, as well as a number of other false twist texturing machines, the gear housing 12 (see FIG. 8) has a number of openings which, according to the present invention, are closed by damped sheet metal panels 102. Panels 102 may have their inside surfaces lined with polyurethane foam or other sound absorbing material. Clearly, the panels may be of any desired shape to fit the openings found on a specific housing. Also, sound absorption panels, such as at 104, should be used to line the inside surface of the door 106 of the housing 12. It has also been found useful to reposition and sound insulate the cooling vent opening 108 of the gear housing 12 by placing the opening in the top of the housing and surrounding the opening with a partial enclosure 110, which is lined with suitable sound absorbing material 112. The original opening in the end of the housing is sealed off.
In some spindle platform portions of texturing machines, it may be necessary to provide additional insulating walls between the pulley cover 40 and the spindle platform 30, to complete the enclosing of the head end tape pulley 50.
Another source of noise has been found to be the spindle tape 58 interaction with the spindle whorls. According to the present invention the conventional half-inch woven-surface tapes are replaced by 3/8-inch rubber-surfaced tapes to reduce the tangential tape drive noise.
Another source of noise is the V-notch threading aid at the top of each spindle, which produces a periodic pressure disturbance at a frequency twice that of the spindle rotational speed. Removing the V-notch and all perforations in the spindle wall eliminates this source of noise, amounting generally to an additional 2 or 3 dB(A) reduction after all the other above modifications have been made on the machine.
As a result of implementing the foregoing techniques a noise reduction of 8-10 dB(A) has been documented at a typical operator position in the center of a Leesona 553 36-spindle machine section running at 300,000 rpm. Measurements before and after modifying the machine were made at a position 60 inches high, measured vertically from the operator ramp, and 20 inches out, measured horizontally from the spindle line of the machine. The machine was situated on a hard reflecting plane in an otherwise acoustically soft environment with low ambient noise levels.
With the foregoing noise abatement devices, it will be seen that free access to the production portions of the machine is still provided and a very satisfactory reduction in noise level will be obtained. Further, it will be appreciated that implementing the noise abatement procedures described above will be relatively inexpensive, thus rendering it very practical to incorporate such modification in texturing machines.
As will be apparent to those skilled in this art, various modifications to the foregoing procedures and devices may be employed without departing from the spirit and scope of the present invention as defined in the appended claims. | The disclosure embraces noise abatement apparatus and a method of abating noise in a yarn texturing machine of the type that employs rotatable spindles driven by endless belts, heater means and yarn transport means, all of which are spaced along a frame between a gear housing and a motor housing; the apparatus includes sound insulating walls for enclosing the timing belt driven pulley located nearest the gear housing together with tunnels lined with sound absorbing material through which the endless belts of the machine pass from the gear housing over the frame of the machine; also, there are included means for isolating the vibrations of idler pulleys for the drive belts from the mounting rail as well as reducing sound propagation from the rotating idler pulleys; noise generated from within the gear housing of the machines is also suppressed. | 3 |
BACKGROUND OF THE INVENTION
The invention relates to a card reader for a games machine and especially to a chip card reader that can be used to test the contents of the card in order to enable the user to use it in the games machine or recover it when he wishes to stop playing.
In casinos and as a general rule in gaming rooms, games machines are used that work with coins or tokens that the user purchases at the cashier's desk.
A standard games machine is like the one shown in FIG. 1. It has a body or body-frame 101 provided with a window 102 or a display screen with which the user can be shown the parameters of the game. The machine may have an arm 103 or a control button, not shown, that can be used to start play. For example, this command may cause symbols to flow across the screen. The turn is won if the symbols form a winning combination and if not it is lost.
To be able to start play, the player must put one or more tokens 105 in a paying mechanism 104. When the turn is won, a feeder box 106 releases a certain number of tokens that corresponds, according to the rules of the game, for example to n times the amount of the wager.
The tokens at present are most usually metal tokens which may have different colors and diameters corresponding to different face values. They may also be made of materials of different natures. In order that the payment mechanism 104 may be able to distinguish between them, it is then necessary to use the magnetic signature given by the materials of different natures and/or different dimensions. The old practice of using coins instead of tokens is sometimes still used.
Apart from possible attempts at fraud, the use of tokens is not practical. It calls for the presence of relatively large numbers of staff in a central cashier's desk and accounting operations that could give rise to errors or even fraud. Furthermore, the use of tokens slows down the use of the machine and limits the amount of money that can be wagered.
It can be seen that a more modern system is replacing the use of tokens. However, to avoid upsetting the habits of the players and in order to preserve certain socially convivial aspects of the machine, the use of tokens is not being completely abandoned.
For this purpose, systems of cards such as chip cards are used. The games machine should therefore have a card reader that can read the contents of the card, namely the available sum of money memorized in the card which should be capable of processing the transactions made by the games machine at the user's request and which should be capable, after transaction, of making a recording in the card of the newly available sum.
However, these cards have a certain cost and when the amount of money recorded in the cards has been used up and the cards can no longer be used in their state, the owner of the games machine may need to recover them in order to reuse them.
OBJECTS AND SUMMARY OF THE INVENTION
The invention therefore relates to a chip card reader for a games machine capable of carrying out debit or credit operations on the monetary contents recorded in a chip card according to the wagers and gains made by a player. The reader comprises, for this purpose, a central processing unit, an associated program memory and at least one electrically re-recordable memory, characterized in that it further comprises:
means to compare the amount of money available at the end of a game with that of a given minimum monetary value, delivering a rejection signal when this available amount is smaller than or equal to the minimum value,
means to swallow up the card that are controlled by this rejection signal.
Furthermore, the invention provides for the reduction of the number of times that the memory of the chip card is accessed in order to limit its wear and tear.
According to the invention therefore, it is provided that:
after the insertion of a card into the reader, the money value recorded in the card is transferred into the re-recordable memory;
the central control unit updates the contents of the re-recordable memory, at each game played, as a function of the wages and gains made;
at the end of the game, the card restitution device activates the transfer, to the card, of the updated contents of the re-recordable memory and then, if the amount available is greater than the minimum value, it activates the restitution of the card to the player.
BRIEF DESCRIPTION OF THE DRAWINGS
Other particular features and advantages of the invention shall appear clearly in the following description given by way of a non-restrictive example with reference to the appended figures, of which:
FIG. 1 shows a games machine according to the prior art, already described here above;
FIG. 2 shows a games machine according to the invention;
FIG. 3 shows an exemplary circuit of the card reader according to the invention;
FIG. 4 shows circuits of the reader more specific to the invention.
FIG. 5 shows an organization of more specific circuits used to implement the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The games machine according to the invention shown in FIG. 2 is essentially identical in its appearance and in its operation to the standard machine shown in FIG. 1. Indeed, it is very important not to disturb the player in his habits.
FIG. 2 does not show the means that can be used to make the games machine function with tokens, but these means could exist and coexist in order to work with the card reader according to the invention.
The card reader 2 which enables the machine to be made to work by means of a "chip" card is preferably fixed to the right-hand side of the machine at an appropriate height so that a chip card can easily be inserted into the input slot 3 of the reader 2 and so as to enable the reading of the indications of a display device 7 with which this reader is provided. This device is used to indicate various data elements, especially the amount of the balance. The reader also has a means, such as a button 45, to activate the restitution of the card. The reader 2 may also be integrated into the machine.
So-called "chip" cards are currently well known in the prior art. There are two major groups of such cards, namely prepayment cards, used for example in telephone booths, and bank cards.
The chip card used in the games machine according to the invention will preferably have an external and electrical form identical to that of presently standardized cards, such as the prepayment cards or re-chargeable cards that are available in the market and that will make it possible, in particular, to totalize the gains coming from the wagers won. It will be possible however to provide for the use of any type of appropriate card, especially cards presently designed to play the role of electronic wallets which are particularly designed so that they can be replenished in an appropriate reader.
FIG. 3 gives a schematic view of the system for inserting a card into the reader and extracting it.
The reader 2, on its front face, has the input slot 3 behind which there is a card-grasping system such as a small conveyer belt 30 or a roller system which, by friction or clamping, takes charge of a card 1 that is inserted through the slot 3. A control system 31 such as a motor activates the motion of the device 30 so that it places the card in position before a read/write interface 20. A system of this kind is known in the prior art.
With the card in position before the read/write interface 20, this interface reads the contents of a memory possessed by the card and transmits these contents to the circuit 4 of the reader. The contents correspond to a sum of money that the user will be able to wager in the games machine.
The system of FIG. 3 also has a button 45 that can be activated by the user and enables the transmission of a signal to the circuit 4 so that this circuit commands the device 21 and the grasping device 30 to eject the card 1 through the slot 3 in order to return it to the player.
At the far right of the grasping device 30, there is a bin 5 that is used to receive the cards under conditions of operation that shall be explained here below.
FIG. 4 shows the circuits 4 of the reader. The circuits are very similar to those of the chip card readers such as bank cash dispensers for example.
They comprise essentially a central processing unit such as a microcontroller 40 that manages all the operations. This microcontroller is connected by a bus to a program memory 403, of the EPROM type for example, a second memory 42 of the EEPROM type for example that can be used to store a certain number of parameters which are likely to change such as the amount of money wagered and a third RAM type memory 405 acting as a random-access memory for the performance of the program of the microcontroller.
The memory designed to record the amount of money wagered changes constantly during the games played by the user and this memory 42 could be of another type than an EEPROM memory.
The microcontroller may, if necessary, be connected to an RTC (real time clock) circuit and to a safety module that comprises a DES or RSA diversification algorithm.
The bus is also connected to the display unit 7 used in particular to display the sums wagered, the gains obtained and the remaining sums. It is connected to the read/write interface 20 designed to transfer information to/from the card 1 of the player and possibly to/from the cards intended for staff to intervene for example on the parameters of the payment system (in particular the value associated with the minimum and maximum buttons). Finally, the bus is connected to a number of control buttons, in this case two buttons 408 and 409. These buttons in this exemplary embodiment are used by the players to make wagers. The first button corresponds for example to the minimum wager and the second to the maximum wager. Finally, in the reader, there are a certain number of interfaces designed to connect it to the exterior. In this exemplary embodiment, there is an interface 410 designed to connect it to the games machine.
The interface 410 enables the decoding of the instructions that appear on the bus designed for the games machine. The physical interface designed to be connected to the games machine takes the form of a connector 412 comprising a set of pins used to send out and to receive the signals to/from the games machine.
The signals that appear at this connector 412 will be determined by instructions flowing in the bus of the reader and decoded by the interface 410. These instructions will themselves be determined by the working program laid out in the memory 403. The program and the interface comprising the connector 412 are adapted to the types of machines used. In the exemplary embodiment described, the machine meets the specifications of the machines currently existing on the market.
FIG. 5 shows an organization of more specific circuits used to implement the invention.
The microcontroller 40 or microprocessor μP has ports S20 connected to the read/write device 20. At these ports, it receives the value of the amount available in the card. It sends this value to the memory 42.
At each transaction, the memory 42 sees this value modified by the microcontroller 40.
Furthermore, the memory 42 is designed to contain a minimum value (0 for example) below which the user can no longer use his card and below which he must be prohibited from continuing to play. At each transaction, the modified value of the available amount is compared with this minimum value in a comparator 41 which may be a wired logic circuit of the microcontroller 40 or a program contained in the ROM and performed by the microcontroller. If the available amount is smaller than the minimum value, the circuit 41 sends out a rejection signal and activates a confiscation control circuit 47 which commands the card-grasping device to route this card to a confiscation zone 5 (see FIG. 3). According to the operating mode of the reader, this confiscation may also be decided upon when the available amount is equal to the minimum value.
The circuit 41 also inhibits a restitution circuit EJECT 48 activated by the button 45, the role of which is to normally activate the restitution of the card to the user by the device 30.
When a player desires to use the reader 2, he inserts his card 1 into the slot 3 of the reader 2. This insertion launches the operation of the reader. The contents of the card 1 are then transferred to the memory 42. These contents are checked in order to validate their existence and their amount. This validation will make it possible, for example, to eliminate counterfeit cards or cards belonging to persons recorded in a black list that prohibits them from playing. It will be done by means of security recognition methods well known in the prior art.
When these controls have been performed and recognized to be valid, the microprocessor 40 displays the amount of the credit contained in the card on the display unit 7. The player then chooses the amount of the wager that he wishes to bring into play by pressing one of the two buttons 408 or 409. For intermediate wagers between the minimum wager and the maximum wager, the player can press the button 408 several times until he reaches the maximum wager. Certain machines prohibit maximum wagers by means of an inhibition signal sent by the machine. This action will be taken up on the display unit in various ways, for example by the display of the wager or of the decremented contents of the credit in the card, or both successively or simultaneously.
The player will then make the games machine work in an ordinary way, for example by activating the lever 103.
Depending on the result of the game, the reader receives a gain or a loss from the games machine. The microprocessor 40 updates the memory 42 by updating the amount remaining to the player's credit.
The value of the amount available is transferred to the comparison circuit 41 along with the minimum value that may be available. If the available amount is greater than the minimum value, the gain/loss obtained and/or the amount of the new credit is displayed on the display unit 406 and the player can once again play without having to recover tokens that would be redistributed if the machine were working with tokens.
It can be seen that it is possible to avoid loss of time as compared with the situation where tokens have to be obtained and put them back into the machine. The profitability of the machine is thus greatly improved.
If the available amount is smaller than the minimum value, the comparison circuit 41 puts out an inhibition signal Inh to the games machine. Furthermore, this signal is transmitted to the control circuit 47 which acts on the control device 31 to route the card towards the receptacle 5 internal to the reader.
If necessary, before this command, the microprocessor 40 may send the read/write interface 20 the newly updated amount so that it records it in the memory of the card 1.
When the user wishes to stop playing, he operates the button 45. This button applies a signal to the microprocessor 40. The microprocessor transfers the value of the available amount contained in the memory 42 to the read/write interface 20 through the link S20. This link records this new amount in a memory of the card 1. Furthermore, the microprocessor sends out a signal EJECT that is transmitted to the card restitution control device EJECT 48. This device activates the control means 31 to make the device 30 restitute the card through the slot 3 of the reader.
It must be noted that, during this operation triggered by the handling of the button 45, the available amount recorded in the memory 42 may be communicated to the comparison circuit 41 and compared with the minimum value. If the available amount is smaller than the minimum value and even, depending on the type of operation of the card, if there is equality, a rejection signal Inh may be emitted to prohibit the working of the circuit EJECT 48 and to activate the working of the device 47 with a view to keeping the card in the reader.
Here above, the minimum amount may be a zero value or the instructed value of the card.
The various transactions used by the cards of the players as well as a certain number of information elements pertaining to the game, among others the amounts distributed following the gain as explained further above, are stored in the memory 42 of the card reader. This makes it possible, at different times, for example at the end of the day, to collect this information with a view to performing checks and drawing up statistics. For this purpose, it is possible for example to use an additional interface, for example an RS232 serial line or an infrared system provided with an appropriate connector placed on the reader. Another approach consists in using a card known as MaxiCard (registered mark of the Applicant) with the manager of the games machine. This card is inserted into the reader which recognizes it and implements the program for the loading into the card of the data elements collected in the memories of the payment mechanism reader. | Card reader for game machine with a memory (42) which contains a minimum credit value and receives the credit value available from a card. At each stage of the game, the available credit value varies. The available credit value is compared, on each transaction, with the minimum value. When the available credit value is less than the minimum value, a circuit (47) triggers seizure of the card. A reader of this type can operate by performing all transactions in a memory within the reader, only reading the card memory when the card is inserted into the reader and updating it when the card is ejected. | 6 |
RELATED APPLICATIONS
This application is related to U.S. application Ser. No. 637,795 (corresponding to Japanese Patent Application No. 49-147239) entitled "Multi-Cylinder Internal Combustion Engine," and filed on the same date herewith.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus for purifying exhaust gas from a multi cylinder internal combustion engine and in particular is related to an ignition system for a multi cylinder internal combustion engine.
2. Description of the Prior Art
Recently, as is well known, air pollution caused by exhaust gas from internal combustion engines has increased resulting in serious social problems. In order to reduce the pollutants in exhaust gases, various types of apparatus for purifying exhaust gases have been proposed. Each proposed apparatus has some defect such as, inadequate purifying performance, increased size and complexity of the apparatus, and the like.
Vehicle engines are generally designed so that the air-fuel ratio in each of the cylinders is kept as uniform as possible. However, in the exhaust gas, the concentration of nitrogen oxides (referred to as NOx hereinafter) is high at the air-fuel ratio at which the fuel consumption is minimized under a partial load condition. On the other hand, the concentrations of both of carbon monoxide (referred to as CO hereinafter) and hydrocarbons (referred to as HC hereinafter) are high when the throttle is opened near its extreme position because of the low air-fuel ratio providing maximum engine output. Also, since the air-fuel mixture is incompletely burned in the cylinder while the engine runs at lower speed due to reasons such as low temperature of the inside wall of the cylinder, exhaust gases containing unburned components such as CO and HC are produced. Therefore, conventional multi cylinder internal combustion engines suffer from the defect that one or more concentrations of NOx, CO and HC in the exhaust are increased under almost any running condition of the engines.
As is well known, the concentrations of the CO and HC can be reduced by the effective combustion thereof at higher temperatures with sufficient air charges, but such conditions increase the concentration of the NOx. In order to reduce the NOx concentration, the combustion temperature, and concomittantly the engine efficiency, should be lowered. One such approach includes an exhaust gas recycling system wherein the exhaust gas is partially diverted to the intake system. However, this approach has defects. Since the combustion becomes unstable without additional fuel charges, additional fuel is added simultaneously with the recirculation of the exhaust gas by the operation of enriched air-fuel mixture apparatus. However, as it is required to control the unburned gas, including the residual gas, in the combustion chamber at about a constant ratio, the apparatus for the latter method can not be simplified in structure and is expensive.
SUMMARY OF THE INVENTION
According to the present invention, the foregoing various defects are eliminated by a design which has taken in consideration the following properties in internal combustion engines.
1. NOx concentation is reduced both at lower air-fuel ratios and at higher air-fuel ratios;
2. CO and HC concentrations are increased at lower air-fuel ratios; and
3. CO and HC concentrations are reduced and the oxygen concentration is increased at higher air-fuel ratios, provided there are no misfirings.
The invention is a multi cylinder internal combustion engine, in which all of the cylinders are grouped into a first group of cylinders to be supplied with enriched air-fuel mixture and a second group of cylinders to be supplied with enriched air-fuel mixture and a second group of cylinders to be supplied with lean air-fuel mixture to thereby reduce the NOx concentration. In the exhaust system, exhaust gases from each group of cylinders are mixed, wherein CO and HC from the first group are subjected to recombustion or oxidation reaction by way of exothermic reaction mainly due to the oxygen from the second group, to thereby reduce the concentrations of the CO and HC. At the same time, ignition timings for the first and second groups are separatedly controlled to minimize the reduction in the engine output and to effectively reduce the emission of noxious gases, CO, HC and NOx.
DESCRIPTION OF THE ACCOMPANYING DRAWINGS
This invention is to be described by way of a preferred embodiment thereof referring to the accompanying drawing, wherein
FIG. 1 is a vertical section of a four-cylinder internal combustion engine in accordance with the present invention.
FIG. 2 is another vertical section of the engine taken along the lines II--II of FIG. 1;
FIG. 3 is a vertical section of an ignition apparatus for the engine of FIG. 1;
FIG. 4 is a transverse section of the embodiment of FIG. 3 taken along lines IV--IV; and
FIG. 5 is a graphic representation for the illustration of ignition timing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 and FIG. 2, an air cleaner 1 is shown connected to an apparatus 2 for supplying enriched air-fuel mixture to a first group of cylinders and an apparatus 2' for supplying a lean air-fuel mixture to a second group of cylinders. Each apparatus 2, 2' may consist, for example, of a caburetor, fuel injection pump or the like. In the embodiment shown, a caburetor is employed. There are also shown venturies 3 and 3', throttle valves 4 and 4' and intake manifolds 5 and 5' for distributing the respective types of air-fuel mixture into the cylinders belonging to the corresponding groups. In the structure to be described hereinafter, those parts used with the first group of cylinders, group (a), are denoted by unprimed numbers, whereas those parts used with the second group of cylinders, group (b), are denoted by primed numbers. The cylinder group (a) and the cylinder group (b) have substantially the same construction.
The engine further includes, intake valves 6 and 6', exhaust valves 7 and 7', pistons 8 and 8' for each of the cylinder groups (a) and (b), connecting rods 9 and 9' for said pistons, crank shaft 10 connected to said connecting rods, combustion chambers 11 and 11', exhaust manifold 12, exhaust gas purifying apparatus 13, exhaust pipe 14 connected to said exhaust purifying apparatus 13, cylinder head 15, crank case 16, oil pan 17 and a fan 18 for cooling engine cooling water. The apparatus 13 may be constructed as a thermal reactor in this embodiment, provided in the exhaust system, and used for purifying the exhaust gas by means of catalysts or by way of re-combustion.
Reference numeral 20 represents retaining nuts for the above described air cleaner 1 and reference numeral 19 is a nut for mounting the above described crank shaft 10 to be crank case 16. Numerals 21, 22, 23 and 24 denote, respectively, ignition plugs provided to each of the four cylinders.
When the engine is started, air is aspirated through the air cleaner 1, mixed with fuel to form an enriched air-fuel mixture and a lean air-fuel mixture in the carburetor 2 and 2', respectively, passed through respective intake manifolds 5 and 5', and then admitted into the combustion chambers 11 and 11'. Thereafer, the air-fuel mixture goes through compression, ignition and expansion strokes as in the well known, and the remaining gases are passed via the exhaust manifold 12 to the thermal reactor 13.
By directing the outlet of the exhaust manifold 12 to the thermal reactor in a manner to cause swirling of the exhaust gas of the enriched air-fuel mixture and that of lean air-fuel mixture, the exhaust gases will mix throughly with each other after leaving said exhaust manifold 12. The CO and HC in the exhaust of the enriched air-fuel mixture is subjected to recombustion with residual oxygen contained in the exhaust of the lean air-fuel mixture to form a final exhaust gas of less CO and HC concentration which is released to the atmosphere via the exhaust pipe 14.
Additionally, since combustion occurs in the first group of cylinders at a lower air-fuel ratio and the second group of cylinders at a higher air-fuel ratio, the resulting NOx can be reduced to about one-tenth of that occurring in conventional engines wherein combustion is performed at the same air-fuel ratio for all of the cylinders.
Further, by adjusting the combined air-fuel ratio for all cylinders so as to be equal to or slightly above the theoretical ratio, CO and HC can be subjected to recombustion without providing additional air charge means to the exhaust system.
Referring to FIG. 3 and FIG. 4 a description will now be given of the ignition apparatus of this invention mounted to the multi cylinder internal combustion engine having the foregoing structure. The ignition apparatus is constructed as a wholly transistorized contactless ignition apparatus. A signal generator comprises a pair of pick-up coils 25 and 26 and a magnet 27. A driving shaft 28 is rotated by a means, such as a cam shaft (not shown) of the engine, and the rotation of said driving shaft 28 is transmitted via a governor 29 to the magnet 27 engaged over said shaft. The magnet 27 has a pair of poles N and S disposed symmetrically about the center of rotation. The pick-up coils 25 and 26 are respectively located on base plates 30 and 31 which are mounted within a distributor housing 32 so as to be individually rotatable in a coaxial relation to said driving shaft 28 in a manner explained hereafter. The magnet 27 and a distributor rotor 33 are secured integrally and are rotatable coaxially. The distributor rotor 33 distributes electric energy in a conventional manner by successively electrically connecting an electrode 34 to four electrodes 35 arranged on a distributor cap 36. The base plates 30 and 31 are rotated by different negative pressure diaphragms 37 and 38 for controlling the ignition timing of the plugs 21-24. That is, negative pressure for advancing ignition timing is applied to each of the chambers 41 and 42 sealed by each of the diaphragms 39 and 40 of the negative pressure diaphragms 37 and 38. The device 37 is adjusted so that the diaphragm 39 moves rod 45 against the force of a coil spring 43 to rotate clockwise the base plate 30 on which the pick-up coil 25 is attached, thereby causing a change in the induction timing of the electromotive force in the pick-up coil 25 relative to the rotation of the magnet 27 to obtain a negative pressure-ignition timing characteristic represented by the curve X in FIG. 5. On the other hand, the device 38 is adjusted so that the diaphragm 40 moves rod 46 against the force of the coil spring 44 to rotate clockwise the base plate 31 on which the pick-up coil 26 is attached, thereby causing a change in the induction timing of the electromotive force in the pick-up coil 26 relative to the rotation of the magnet 27 to obtain a negative pressure-ignition timing characteristic respresented by the curve Y in FIG. 5.
Since the pick-up coil 26 is mounted with an angle of 90° + α° relative to the pick-up coil 25, said α° being 2.5° in one specific embodiment, the ignition timing for the pick-up coil 26 is -5° as expressed in the crank angle relative to the ignition timing of 0° for said pick-up coil 25 during idling condition. Generally, the ignition timing is advanced as the load for the engine increases above the idling condition. In the present invention, by adjusting the resilient forces of the coil springs 43 and 44 or the areas of the diaphragms 39 and 40 subjected to the negative pressure created in the engine as the rpm increases, the ignition timing for the pick-up coil 26 advances at a greater rate than that for the pick-up coil 25. This is illustrated by curves X and Y. As shown curve X lies above curve Y during medium and low engine load conditions, but curve Y lies above curve X during high engine load conditions.
In FIG. 4, there is also illustrated a circuit comprising an igniter amplifier 47 preferably of the transistorized type, an ignition coil 48, a battery 49 and a key switch 50. Secondary winding 51 of the ignition coil 48 is connected by way of the electrode 34 to the distributor rotor 33 to thereby distribute electrical energy generated in said ignition coil 48 through the four electrodes 35 to each of the ignition plugs 21, 22, 23 and 24 shown in FIG. 1. The electric connections are made in such a manner that the ignition timings of the ignition plugs 21 and 22, provided for the first cylinder group (a) supplied with the enriched air-fuel mixture, are controlled by the pick-up coil 25, and the ignition timings of the ignition plugs 23 and 24, provided for the second cylinder group (b) supplied with lean air-fuel mixture, are controlled by the pick-up coil 26. The curve Z shown in FIG. 5 represents a centrifugal ignition timing advancing characteristic produced by the rotational movement of the magnet 27 relative to the drive shaft 28 caused by the action of the governor 29 resulting from the rotation of the distributor.
In the ignition apparatus having the foregoing construction, the ignition timings for the first cylinder group (a) are controlled by the governor 29 and by the negative pressure diaphragm 39 for advancing ignition timing, so that the ignition timings for the ignition plugs 21 and 22 provided for said cylinder group (a) are represented as the sum of the values given by the curve X and the curve Z in various load regions as shown in FIG. 5. Similarly, the ignition timings for the second cylinder group (b) are controlled by the governor 29 and by the negative pressure diaphragm 38 for advancing the ignition timing, so that the ignition plugs 23 and 24 provided for said cylinder group (b) are represented as the sum of the values given by the curve Y and the curve Z in various load regions as shown in FIG. 5.
Accordingly, the ignition timing for the second cylinder group (b) is behind that of the ignition timing for the first cylinder group (a) during medium or low engine load conditions. However, at high engine load conditions, the above ignition timings are reversed for the two cylinder groups.
Due to the basic nature of combustion, more NOx is produced from the second cylinder group (b) (receiving the lean air-fuel mixture) than from the first cylinder group (a) (receiving the enriched air-fuel mixture), when the ignition timings for them are the same. Therefore the total emission of NOx can further be reduced significantly by decreasing the NOx emission from said second cylinder group (b). By retarding the ignition timing for the second cylinder group (b) as much as possible, relative to the timing of group (a), during medium or low engine load conditions, the maximum temperature in the combustion chambers 11' is lowered and consequently the amounts of NOx exhausted from said cylinder group (b) are thereby reduced. Additionally, since the unburned fuel in cylinders (b) will exothermically oxidize due to the excess O 2 in the exhaust of cylinders (b), the exhaust gases will have an increased temperature which improves the efficiency of the exhaust gas purifying apparatus 13 thereby contributing to the burning of HC and CO from the exhaust of cylinders (a). In addition, reduction in engine outputs and in specific fuel consumption are minimized by advancing as much as possible the ignition timing for the other cylinder group (a).
During high engine load condition, by controlling the ignition timing of the cylinder group (b) nearly identical to or in advance of the ignition timing of the cylinder group (a), sufficient engine outputs can be produced also in the cylinder group (b) thereby enabling the improvements for the total engine outputs and fuel consumption.
During the high engine load condition further improvement in the outputs can of course be attained by somewhat reducing the air-fuel ratio. While in the embodiment described above the same centrifugal ignition timing is given to both of the pick-up coils 25 and 26, more effective exhaust purification and further improvements in outputs may be attained by providing different governors having different ignition timing characteristics to each of the pick-up coils 25 and 26 respectively so as to utilize at most of the properties of enriched and lean air-fuel mixtures relative to the revolutional numbers of an engine. Although the description is made to the above embodiment with the transistorized contactless type ignition apparatus, it will easily be understood that quite the same effects and advantages as in the above embodiment can also be attained with a contact breaker type apparatus conventionally used so far. | An ignition apparatus is disclosed for use in a multi cylinder internal combustion engine having a first group of cylinders supplied with an enriched air-fuel mixture and a second group of cylinders supplied with a lean air-fuel mixture. A first control device controls the ignition timing of the first cylinders and a second control device controls the ignition timing of the second cylinders. The first and second control devices are adapted to operate in such a way that the ignition timing for the second cylinders is retarded relative to that for the first cylinders at medium or low load conditions of the engine, and the ignition timing for the second cylinders is advanced relative to or nearly the same as that for the first cylinders under a high load condition. | 5 |
TECHNICAL FIELD
[0001] The present invention relates generally to shower accessories, and more particularly to a liquid agent dispenser for use with a shower head.
BACKGROUND
[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0003] While taking a shower it is common to utilize some type of cleaning agent such as soap, shampoo, conditioner, and/or body wash, for example to ensure a user is able to thoroughly clean their body. As such, residential showers are often littered with many different bottles that are often scattered along the floor and/or shelves. When so located, users may have difficulty identifying a proper bottle, or may slip on a bottle while bathing under the shower stream.
[0004] In addition to the above, commercial locations such as hotels, motels and locker rooms, for example, typically spend thousands of dollars each year to provide their guests with individual bottles of body wash and/or bars of soap, for example, which are discarded upon being opened by a guest. Such a process results in a huge waste of money and materials.
[0005] Regardless of where the shower is located, users must still dispense the cleaning agent directly onto their body and then manually spread the agent across their body as it encounters the shower stream. However, such a process often results in an uneven distribution of the cleaning agent, as some body portions are easier to access than others.
[0006] Accordingly, it would be beneficial to provide a liquid agent dispenser that can store and dispense any type of liquid agent directly into a shower head, so as to alleviate the drawbacks of the above noted devices.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a shower head liquid agent dispenser. One embodiment of the present invention can include a storage tank having a hollow interior space for storing a liquid agent such as soap, shampoo, conditioner and/or body wash. A first tubular member is connected to the bottom end of the storage tank and functions to feed the stored agent to a valve which can be manipulated by a user to between an on and off position, in order to control an operation of the device. A second tubular member can feed the liquid agent into a tee fitting which is connected to a building's shower arm. The tee fitting can function to mix the liquid agent with shower water and dispense the same into the shower head.
[0008] Another embodiment of the present invention can include an aerator that is interposed between the tee fitting and the shower arm.
[0009] Yet another embodiment of the present invention can include a shower head having the above described liquid agent dispenser secured thereon.
[0010] This summary is provided merely to introduce certain concepts and not to identify key or essential features of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Presently preferred embodiments are shown in the drawings. It should be appreciated, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0012] FIG. 1 is an exploded parts view of a shower head liquid agent dispenser that is useful for understanding the inventive concepts disclosed herein.
[0013] FIG. 2 is a perspective view of the shower head liquid agent dispenser in operation, in accordance with another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the description in conjunction with the drawings. As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the inventive arrangements in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention.
[0015] As described herein, the term “removably secured,” and derivatives thereof shall be used to describe a situation wherein two or more objects are joined together in a non-permanent manner so as to allow the same objects to be repeatedly joined and separated.
[0016] As described herein, the terms “connector,” “complementary connector” and derivatives thereof can include any number of different elements capable of repeatedly securing two items together in a nonpermanent manner. In the illustrated examples, the preferred connector utilizes a plurality of embedded elements forming a screw thread along an outside periphery of one component, and another plurality of embedded elements forming a screw thread along an inside periphery of a second component. As is known to those of skill in the art, such threaded elements can act to removably connect the illustrated components together in a secure and watertight manner. Threaded elements having lands and grooves for securing complementary objects together via a twisting motion are extremely well known.
[0017] Although described above as utilizing threaded elements capable of creating a secure attachment point between two objects when a rotational force is applied thereto, this is for illustrative purposes only, as any number of devices capable of creating a removable seal between two items can also be utilized. Several nonlimiting examples include opposing strips of hook and loop material (i.e. Velcro®), magnetic elements, tethers such as straps and ties, and compression fittings such as hooks, snaps and buttons, for example. Each illustrated connector can be permanently secured to the illustrated portion of the device via a permanent sealer such as glue, adhesive tape, or stitching, for example.
[0018] Identical reference numerals are used for like elements of the invention or elements of like function. For the sake of clarity, only those reference numerals are shown in the individual figures which are necessary for the description of the respective figure. For purposes of this description, the terms “upper,” “bottom,” “right,” “left,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIG. 1 .
[0019] FIGS. 1 and 2 illustrate one embodiment of a liquid agent dispenser 10 for use with a shower head assembly, that is useful for understanding the inventive concepts described herein. As shown, one embodiment of the dispenser 10 can include, essentially, a storage tank 12 , a first tubular member 20 , a valve 30 , a second cylindrical member 40 , a tee fitting 50 and an aerator 60 . Each of these components can be joined together and attached to a shower head assembly (See FIG. 2 ) to dispense any type of liquid agent that is stored in the tank 12 through the shower head assembly.
[0020] The tank 12 can function to store any type of liquid dispensing agents such as various soaps, shampoo, conditioner and/or body wash, for example. As described herein, the tank 12 can include a continuous outer wall 13 having a bottom end 14 and a neck 15 along the top end. The tank can include a hollow interior space 12 a that is accessible via the neck 15 and an aperture 14 a positioned within the bottom end. A cap 16 can be removably secured along the neck 15 via a connector such as the illustrated screw threads 15 a , for example.
[0021] The first tubular member 20 can function to transfer the stored liquid agent from the tank 12 to the valve 30 . In one embodiment, the member 20 can include a generally hollow conduit having an open first end 21 , and an open second end 22 . The first end 21 can include a shape and size that is complementary to the shape and size of the aperture 14 a of the tank 12 . The first end 21 can be mated with the aperture 14 a via any number of known methodologies such as welding or via threaded elements (not illustrated), for example, so as to form a watertight seal that allows the stored liquid agent to enter the open first end of the tubular member 20 .
[0022] In the preferred embodiment, the second end 22 of the first tubular member 20 can be removably secured to the below described valve 30 via a connector such as the illustrated threaded elements 22 a and 32 a , for example.
[0023] The valve 30 can function to allow a user to selectively allow and prevent dispensing of the liquid agent into the shower head assembly. In one embodiment, the valve 30 can include a main body 31 , having a first end 32 , a second end 33 , and rotatable handle 34 . Turning the handle 34 raises or lowers an internal valve pin which, respectively, allows fluid to pass through the valve body 31 and the ends 32 and 33 .
[0024] The second tubular member 40 can function to transfer the liquid agent from the valve 30 to the T-shaped connector 50 . In one embodiment, the member 40 can include a generally hollow conduit having an open first end 41 , and an open second end 42 . The first end 41 can be removably secured to the second end 33 of the valve 30 via a connector such as the illustrated threaded elements 41 a and 33 a , for example. Likewise, the second end of the second member 42 can be removably secured to the middle opening 53 of the below described tee fitting 50 via a connector such as the illustrated threaded elements 42 a and 53 a , for example.
[0025] The tee fitting 50 can function to introduce the liquid agent into the stream of water. In one embodiment, the tee fitting can include an open first end 51 , an open second end 52 , and a middle opening 53 . The middle opening 53 can be removably secured to the second end 42 of the second member 40 via a connector such as the illustrated threaded elements 42 a and 53 a , for example. The first end of the tee fitting 51 can be removably secured to the threaded end 5 a of a conventional shower head assembly 5 via a connector such as the illustrated threaded elements 51 a , for example.
[0026] An aerator 60 can be secured within, or connected to the second end 52 of the tee fitting 50 and can function to reduce the flow and/or pressure of water entering the fitting so as to allow the liquid agent to be introduced to the water flowing through the tee fitting. As shown, one end of the aerator 61 can be removably secured to the threaded end 1 a of a conventional building shower arm 1 via a connector such as the illustrated threaded elements 61 a , for example.
[0027] As described herein, each of the tank 12 , the first tubular member 20 , the valve 30 , the second tubular member 40 , the tee fitting 50 and the aerator 60 can be constructed from any number of different lightweight and durable materials that are resistant to oxidization and corrosion. Several nonlimiting examples can include, for example, stainless steel, hard plastic, composite materials, and the like. Moreover, each of these components can be constructed from identical construction materials or can be constructed from different materials.
[0028] In operation, the tee fastener of device 10 can be interposed between an existing shower arm 1 and shower head assembly 5 , with the storage tank 12 located above the same. When so positioned, a user can operate the shower controls (not shown) so that shower water flows through the tee fitting 50 and exits through the shower head 5 . When a user desires to mix the shower water with the liquid agent stored within the tank 12 , the user can rotate the handle 34 of the valve 30 , so as to allow the liquid agent to be gravity fed down through the second tubular member 40 and into the tee fitting.
[0029] At this time, the velocity and turbulence of the shower water exiting the aerator 60 thoroughly mixes with the liquid agent inside the tee fitting (i.e., shower mixture). As such, the combined shower water and liquid agent exit through the shower head 5 so that the user receives soapy water for showering and washing. As necessary, the user can vary the amount of liquid agent entering the water supply by adjusting the rotation of the valve handle 34 .
[0030] As such, the supply of liquid soap is easily accessible to the person taking a shower. Furthermore, the supply of liquid soap stored within the soap tank 12 exceeds the capacity of conventional bar soaps and containers of liquid soaps.
[0031] As described herein, one or more elements of the shower head liquid agent dispenser 10 can be secured together utilizing any number of known attachment means such as, for example, screws, glue, compression fittings and welds, among others. Moreover, although the above embodiments have been described as including separate individual elements, the inventive concepts disclosed herein are not so limiting. To this end, one of skill in the art will recognize that one or more individual elements such as the storage tank 12 , the first tubular member 20 , the valve 30 , the second cylindrical member 40 , the tee fitting 50 and/or the aerator 60 , for example, may be formed together as one or more continuous elements, either through manufacturing processes, such as welding, casting, or molding, or through the use of a singular piece of material milled or machined with the aforementioned components forming identifiable sections thereof.
[0032] To this end, in another embodiment, the ends of the valve 30 can be in direct communication with each of the storage tank 12 and the tee fastener, thereby eliminating the first and second tubular members. Moreover, in yet another embodiment, each of the above described components can be formed integrally with a new shower head assembly and/or shower arm, for example, so as to provide a single integrated product incorporating the combined functionality of the above described components.
[0033] As to a further description of the manner and use of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
[0034] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0035] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | A shower head liquid agent dispenser includes a storage tank having a hollow interior space for storing a liquid agent, a first tubular member that is connected to the bottom end of the storage tank, a valve which can be manipulated between an on and off position, a second tubular member that is connected to a tee fitting which is selectively connected to a building's shower arm and a shower head assembly. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] U.S. Provisional Patent Application No. 60/150,835 filed Aug. 26, 1999.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to a tool for preparing bone graft material by loading it into multiple tubes that may then be injected into a site needing bone graft material.
[0004] Bone graft material is typically harvested from a portion of a patient's body, such as a hip, and are used in repair procedures in another site, such as in fusing adjacent vertebra. Cheung et al, in the British Journal of Oral & Maxillofacial Surgery, Volume 35, pages 267-270 (1997) describe a bone graft condensing syringe system which uses a metal syringe, a plugger and a screw on cap along with a metal filling funnel to provide bone graft. Marx & Wong describe the use of a plastic syringe in J. Oral Maxillofacial Surgery, Volume 45, at pages 988-989 (1987) which compacts the bone graft material. A scalpel is required to cut off the needle end of the syringe to extrude out the graft material. Lambert et al., in Journal of Oral Maxillofacial Surg., pages 773-774 (1994) describe a syringe system employing a vented steel disc at the hub end of the syringe. The syringe is filled with bone, compressed with a plunger and extruded out with a steel rod through the hub which pushes out the disc and bone.
[0005] A series of Bonutti patents, U.S. Pat. Nos. 5,329,846; 5,545,222; 5,662,710 and 5,888,219 deal with a bone preparation system that uses a press to remove fluid from human tissue and insert the human tissue back into the person. The tissue may be bone.
[0006] The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with. respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. § 1.56(a) exists.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention provides a tool into which bone graft material is inserted. A ram in the tool fills tubes with the bone graft material. The filled tubes are then used to deploy bone graft material where needed with a second tool pressing the graft material out of the tubes. The tool and fill tubes provide the surgeon with prefilled tubes of known volume for surgical procedures which may be readily extruded into the surgical site.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:
[0009] [0009]FIG. 1 is a perspective view of the bone processing tool;
[0010] [0010]FIG. 2 is a perspective view of the bone processing tool of the invention exploded;
[0011] [0011]FIG. 3 is a side elevational view of the bone processing tool with parts cut away to show showing the tamper loading in bone;
[0012] [0012]FIG. 4 is a side elevational view of the bone processing tool with parts cut away to show showing the plunger filling a fill tube with bone;
[0013] [0013]FIG. 5 is a side elevational view of the fill tube holder;
[0014] [0014]FIG. 5 a is a partial enlarged view of the fill tube holder of FIG. 4 showing bone pushed into the fill tube by the plunger;
[0015] [0015]FIG. 6 is an exploded perspective view of the plunger and plunger rod; and
[0016] [0016]FIG. 7 is a cross-sectional view of the plunger.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Many surgical procedures involve the use of bone graft material.
[0018] Depending on the surgery, the bone graft material may simply be harvested and placed into the situs with little difficulty. However, many procedures require relatively accurate placement of a known volume of morselized bone into the site, such as with in U.S. Pat. Nos. 5,571,189 and 5,549,679 to an expandable fabric bag for stabilizing the spinal motion segment and various cages such as shown in U.S. Pat. Nos. 5,489,308; 5,059,193 to Kuslich; U.S. Pat. No. 4,501,269 to Bagby and U.S. Pat. No. 4,743,256 to Brantigan.
[0019] It has been found that bone graft media tends to jam tubes when the tubes are larger in diameter. Thus, while it is possible to fill a syringe with bone material, the end must be cut off to access the bone material. This cutting step can cause an unwanted injury unless performed very carefully.
[0020] Any taper in a fill tube will tend to cause a channel blockage, even if very high hydraulic pressures are applied. Strangely, the inventors have discovered that too large a diameter allows plugs to form. Smaller tubes have less wall surface area and require less pressure to fill.
[0021] The fill tubes are preferably short enough to handle easily, the preferred length should be about 11″ (27.94 cm) or less. A 0.014″ (0.355 mm) diameter tube has an area of 0.010 sq. inches (6.4 mm 2 ), a circumference of about 0.76″ (1.93 cm) and 50 pounds (22.7 kg) of hand pressure results in 5000 psi (34,473 kPa) within the tube. In contrast, a larger 0.025″ (0.635 mm) diameter fill tube has a circumference of 1.57″ (3.988 cm), and area of 0.049 sq. inches (31.6 mm 2 ) and 50 pounds (22.7 kg) of hand pressure results in 1020 psi (7,032 kPa). There is a relationship between force to diameter, diameter to friction, with length increasing friction.
[0022] The fill tubes distal ends are either entirely open or have a tool that mates with a specific cage to be filled. The proximal end of the fill tubes has a fixture for holding and securing to the filling tube device. The tubes inside diameter may be constant or slightly flared greater distally such that the diameter increases gradually from the proximal to the distal end. Otherwise, the bone material forms arches of particles, generating arch bridge-like strength causing the material to jam. Slots in the filling tool allows debris to fall back out from the filling process. Starting friction is overcome by pneumatic pressure, with air couplings to the piston providing the force to move the bone material into the fill tubes.
[0023] The ability to prepare a number of known volume tubes with bone material that will not jam provides a great advantage to the surgeon. They may be prepared ahead of time and may be used one after the other until the procedure is completed. The fill tubes provide a means for safely and quickly delivering a known quantity of bone material to a specific site. A push rod may be used to eject the bone material from the fill tubes into the surgical site by the surgeon.
[0024] With reference to the Figures, FIG. 1 shows the bone processing tool 10 with a fill tube 12 attached. The bone processing tool 10 includes a pneumatic cylinder 14 and piston 20 which is driven by an air supply and control through attachments 16 , 18 . The controls of the air supply are completely conventional and need not be illustrated herein. The cylinder 14 drives a piston 20 back and forth, which in turn moves plunger 22 and plunger rod 24 back and forth within chamber 26 of housing 30 . Housing 30 includes a region 32 in which bone graft material 34 may be inserted into a narrow slot 38 that leads to a small channel 36 into which plunger rod 24 moves. A bone graft tamper 40 with a tab 42 sized to mate with slot 38 may be used to tamp the bone material into the channel 36 . The fill tubes are attached to the proximal end of the tool via a fill tube holder 44 . The fill tubes 12 have an elongated shaft and a flared distal end 46 which mates with a receptacle 48 in the fill tube holder 44 .
[0025] In operation, a new fill tube 12 is attached to the tool 10 , bone graft material 34 is tamped into slot 38 down into channel 36 by tamper 40 and the cylinder is cycled to cause the plunger to push the bone material into the fill tube. The process is repeated until the fill tube 12 is filled, which may be determined by observing bone graft exiting the proximal end of the fill tube 12 .
[0026] While this invention may be embodied in many different forms, there are shown in the drawings and described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.
[0027] This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto. | A tool for processing an supplying bone graft material in individual tubes for later extrusion into the surgical site includes a pneumatic press and plunger to morselize and fill a plurality of fill tubes. The fill tubes are then used at the surgical site by pressing the bone material out with a push rod. | 0 |
RELATED APPLICATIONS
[0001] This application is related to Provisional Application Serial No. 60/047,484 filed May 23, 1997 and to application Ser. No. 09/050,150 filed Mar. 30, 1998.
FIELD OF THE INVENTION
[0002] The present invention relates to method and apparatus for the thermal ablation of the interior lining of an organ, and more particularly for destruction of Barrett's tissue and other lesions of the gastrointestinal tract by cryo-ablation of the gastrointestinal mucosa (gastrointestinal tract lining).
REVIEW OF THE RELATED TECHNOLOGY
[0003] Barrett's esophagus is a recognized precursor to 50% of all esophageal cancers. The incidence of esophageal cancer is rising and this disease is now among the top 15 cancers (Blot et al, JAMA, 270:1320 [1993]). Barrett's tissue has been found in 10% of an asymptomatic population undergoing upper gastrointestinal endoscopy.
[0004] Standard therapy for esophageal cancer is removal of the esophagus, with mortality rates up to 37%. Treatment of this cancer costs $25,000 to $50,000 dollars per patient.
[0005] Barrett's esophagus is characterized by abnormal cell growth along the inner lining of the esophagus above the lower esophageal sphincter. Recent studies have demonstrated that when the metaplastic columnar epithelium characteristic of Barrett's is removed, healing replaces the Barrett's tissue with normal stratified squamous epithelium (Sampliner et al, Gastrointestinal Endoscopy, 44:532-535 [1966]). This presumably reduces the risk of cancer.
[0006] Lives would be saved if Barrett's tissue could be removed quickly, inexpensively, and with low risk. However, the only available procedures have been slow, costly, uncomfortable, and/or dangerous. As a result, Barrett's esophagus goes untreated in many patients, whose health suffers.
[0007] The known ablation treatments for Barrett's esophagus include laser treatment (Ertan et al, Am. J. Gastro., 90:2201-2203 [1995]), ultrasonic ablation (Bremner et al, Gastro. Endo., 43:6 [1996]), photodynamic therapy (PDT) using photo-sensitizer drugs (Overholt et al, Semin. Surq. Oncol., 1 :372-376 (1995)), and multipolar electrocoagulation such as by use of a bicap probe (Sampliner et al, supra). The treatments are often made with the aid of an endoscope.
[0008] Both sonic and light treatments require expensive apparatus and treat only a small area at one time, so that an operation to remove the Barrett's tissue becomes tedious as well as more costly. One reported treatment with Nd:YAG laser used a 2.2-mm beam to treat large areas of the esophagus (Ertan et al, Am. J. Gastro. 90:2201-2203 [1995]). Furthermore, such therapies are often accompanied by esophageal strictures and significant patient inconveniences; since total avoidance of sun exposure and bright light is required for one month after photodynamic therapy.
[0009] Another problem is that there is no visual indication of which tissues have been treated, or the extent to which tissues have been treated. The physician, looking through an endoscope, cannot see the effects of the sound or light directly.
[0010] Cryotherapy of the esophagus via direct contact with a liquid nitrogen cryoprobe (metal probe cooled to a low temperature) has been studied in both animal models and humans (Rodgers et al, Cryobiology, 22:86-92 (1985); Rodgers et al, Ann. Thorac. Surq. 55:52-7 [1983]) and has been used to treat early esophageal cancer (Grana et al, Int. Surg., 66:295 [1981]). Disadvantages of this modality include the necessity for direct mucosal contact, which temporarily binds the probe to the esophagus, potentiating the risk of esophageal perforation and inability to control the exact area of mucosal ablation. Rodgers et al states that a cryoprobe must include a heating element to allow it to be removed. This precludes removal of the probe until thawing has occurred. The depth of the injury with a solid cryoprobe cannot be reliably controlled. If the tip heater malfunctions, or timing is not precise, the depth of freezing can become dangerous. In spite of the heating element, cats died from esophageal lesions in some cases, apparently caused by freezing too deeply and destroying the esophageal wall entirely. These studies highlight the fact that controlling the amount of tissue that is irreversibly damaged by cooling is one of the main problems with cryosurgery.
[0011] Use of a bicap electrocoagulation probe has been suggested as a means for ablation of Barrett's esophagus (Heier et al, Gastro. Endo., 43:185 [1996]). The use of a bicap electrocoagulation probe also suffers from many disadvantages. Since the tip is small and must be repeatedly energized, the operation will be slow and time-consuming. Furthermore, the depth of injury is difficult to control. Esophageal perforation could occur with excessive duration of the electrocautery current.
[0012] All the known ablation treatments using sound, light, or heat also suffer from another defect, a defect common to all: penetration of the damage. The treatments cannot be adjusted to destroy only the very thin lining with the Barrett's tissue; underlying tissue is destroyed as well.
[0013] As flesh is somewhat transparent to both sound and light, these energies will penetrate some distance below the surface. The proportion of energy absorbed by the tissue is generally constant, and so, at least to a first approximation, the intensity of the light or sound will fall off exponentially with depth. Therefore, the amount of tissue damage will also tend to decrease exponentially with distance. There is consequently no sharp line of demarcation between destroyed tissue and tissue which is not affected: the degree of damage decreases continuously. Healthy tissue is damaged along with diseased tissue.
[0014] The same type of damage results from heat probe or cryoprobe treatments. When the surface temperature of flesh is raised, heat travels by conduction into the tissue. The penetration of the heat—the temperature/depth function—depends on the surface temperature, the exposure time, and the heat capacity of the hot probe in contact with the surface. The degree of damage at any one depth depends on the temperature reached. Similar problems are involved with the freezing associated with contact by a solid cryoprobe.
[0015] Clearly, to raise the tissue temperature to a damaging level in only a thin layer of epithelium, heat must be applied quickly from a very high-temperature probe. However, this creates problems of possible sticking and require precise timing of the hot probe contact duration, lest heat penetrate too deeply.
[0016] Complicating the use of heat, there is also a time factor. Not only the peak temperature reached by tissue, but also how long the tissue “bakes” at the high temperature, determines the amount of damage. (This is the reason cold water should be put onto a burn, even after the burn is away from heat.)
[0017] With none of the existing therapies is one able to precisely control the depth of tissue damage while maintaining a sharp demarcation between damaged and undamaged tissue, with the physician being able to observe the precise location and degree of damage as it occurs. Ideally, the Barrett's tissue should be destroyed with the direct visualization and control by physician in a manner which avoids any substantial damage to adjacent healthy tissue.
SUMMARY OF THE INVENTION
[0018] The present invention overcomes the drawbacks of the prior art by using a direct spray of cryogenic liquid to ablate Barrett's tissue in the esophagus. Liquid nitrogen, an inexpensive and readily available liquified gas, is directed onto the Barrett's tissue through a tube while the physician views the esophagus through an endoscope. The apparatus and method of the present invention can be used to cause controlled damage to the mucosal layer at any location in the gastrointestinal tract in a manner in which re-epithelialization can occur. They can be used not only for the treatment of Barrett's esophagus, which is the preferred application of the present invention, but also for the treatment of any mucosal gastrointestinal lesion, such as tumor, polyps and vascular lesions. The apparatus and method can also be used for the treatment of the mucosal layer of any luminal area of the body which can be reached by an endoscope.
[0019] Liquid nitrogen spray has several distinct advantages over the prior art:
[0020] 1) As compared to some of the prior art therapies, there is a sharp demarcation between damaged tissue and non-damaged tissue. Above the freeze surface, all the cells are killed; below, they are not harmed. Thus, it is possible to ablate the Barrett's, or other gastrointestinal tract lesions, without damaging the underlying tissues. This minimizes both the trauma and the risk of infection.
[0021] 2) Unlike a solid cold probe, liquid nitrogen cannot stick to tissue and cause severe frostbite.
[0022] 3) The layer of destroyed tissue is thinner than with previous therapies, including solid-probe cryotherapy, and this again minimizes the damage as compared to the prior art. The reason that the liquid nitrogen spray can freeze a thinner layer than prior-art therapies is that it instantly boils when it touches flesh, because the temperature difference is usually more than 200° C. Liquids have high thermal conductivities, and to boil a liquid requires large amounts of heat (the latent heat of vaporization). These two factors together mean that heat is removed from the surface of the tissue at an extremely high rate, and because of this rapid surface cooling the freezing depth can be very shallow. The temperature differential in the flesh is much higher than it is with a hot metal probe because heat does not need to travel through a metal; the temperature is generated at the surface itself. As a result, the tissue surface can be frozen to well below zero before the tissue just under that frozen tissue has a chance to appreciably drop in temperature.
[0023] 4) Freezing kills cells, but connective tissue and other body substances are not damaged. Thus, the trauma is less as compared to heat burns. Shepherd et al, Cryobiology 21:157-169 [1984]).
[0024] 5) The cryoablation procedure requires only 15-20 minutes. Animal studies have been done both under general anesthesia and under conscious sedation. Thus, the procedure can be performed on adult humans with a local anesthetic or possibly without any anesthetic at all. Freezing is less painful than other methods of killing tissue because cold inherently anesthetizes the nerves. As the operation of the present invention can be performed without general anesthesia, the cost and danger are both reduced still further over treatments employed by the prior art.
[0025] 6) The cost of the procedure is minimal compared to that of the prior art, not only because of the short time for the operation and the relative safety (reducing insurance costs) but also because the capital cost is relatively low. No special medical grade of liquid nitrogen is required. A storage canister can presently be refilled with liquid nitrogen by a commercial gas service for a delivery fee of approximately $20, plus about $3 per liter for the liquified nitrogen itself. One treatment will use approximately a liter or less. The cost for nitrogen can be as low as $30 per month even if only one treatment is performed during that period.
[0026] 7) The procedure can be conducted in such a manner as to allow constant visualization by the physician of the tissue damage as it occurs. Means are provided for removal of moist air at the distal end of the endoscope while dry nitrogen is sprayed. Thus, fogging of the endoscope lens can be substantially avoided, allowing clear observation of the procedure as it occurs.
[0027] In order to realize the benefits of liquid nitrogen spray in the esophagus, the present invention provides these features:
[0028] (1) A standard “diagnostic” endoscope can be used, which is almost universally available to medical personnel, although a standard “therapeutic” endoscope can also be used. These relatively expensive pieces of equipment need not be purchased for the procedure.
[0029] (2) The endoscope allows the physician to see inside the esophagus and direct the spray of nitrogen. Unlike prior-art therapies, the present invention allows the physician to see what areas have been frozen to a low temperature because the esophageal wall frosts and turns white. The frosting lasts for several seconds because the entire inside of the esophagus is at a low temperature, hovering near freezing during the operation. This is due to the large amounts of cold nitrogen gas generated by boiling of the liquid nitrogen. Thus, it is possible for the physician not only to know what areas are frozen, but what areas have been frozen recently. This allows a systematic progress of cryotherapy over the area of Barrett's tissue without over-freezing or non-freezing of any area.
[0030] (3) The endoscope can be disposed with fiberoptics, a T.V. camera and a display screen to allow the surgeon to view the treatment and treated area of the esophagus.
[0031] (4) The liquid nitrogen delivery equipment can be very inexpensive by medical standards. Nitrogen may be delivered through a catheter of standard flexible tubing, such as TEFLON tubing. Plastic tubing is universally available, inexpensive, and safe because of its low thermal conductivity, which prevents the tubing from sticking to the esophageal wall. Other materials superior to TEFLON could be used.
[0032] (5) The flow of nitrogen can be controlled by a simple, reliable, and low-cost delivery system. The nitrogen container is pressurized to push the liquid through the catheter. In one embodiment of this invention, the flow is hand-controlled by the pressure via a valve located at the nitrogen storage container. If more precise control is needed, the liquid nitrogen may be pumped directly or the flow may be controlled by a valve close to the proximal end of the catheter. As an example, a solenoid valve can be used.
[0033] (6) If a more rapid delivery of liquified gas is required, a pressure building tube or coil for supplying heat can be provided on the nitrogen container or tank. Actuating this pressure building coil causes the liquid nitrogen to build up pressure in the container thus allowing the nitrogen to be more rapidly delivered to the catheter.
[0034] (7) During cryosurgery, the invention provides for removal of gas generated by the brisk boiling of liquid nitrogen. Removal is necessary for several reasons: first, the gas will build up a dangerous pressure if there is no escape path; second, the gas will tend to enter the stomach and bloat it because the esophagus is at least partially blocked by the endoscope, and the lower gastrointestinal tract presents a path of lessened resistance; third, the gas boiled off from the esophageal surface may be at a sub-zero temperature and should be removed to prevent over-freezing; and fourth, the initially moist air can be removed so as to avoid substantial condensation on the endoscope lens.
[0035] (8) The inventors have found that in using the cryospray in the relatively enclosed esophageal cavity the pressure of the spray is to be reduced. If the pressure is not reduced, the high volume of gas could unduly expand in the esophageal cavity and cause patient discomfort and/or rupture of vital tissue. In order to produce a cryogenic spray of reduced pressure, this invention proposes a vent between the gas supply tank and the catheter. Other methods for reducing pressure are envisioned by this invention.
[0036] (9) Importantly, the catheter is supplied attached to a vent. A catheter, not supplied with such a vent, will deliver a high pressure spray which could be injurious to internal tissue. As pointed out, methods other than a vent could be used to reduce pressure.
[0037] (10) The catheter employed by this invention is made of a material which is not brittle, such as PTFE and polyamide. In addition, the catheter is to be insulated. The catheter is designed to withstand extremely cold temperatures without becoming stiff and brittle and without affecting inherent flexibility and maneuverability of the endoscope. For example, the insulated catheter should be capable of withstanding temperatures down to −100° C. The temperature of gas sprayed at the tip is approximately between −20° C. to −50° C. However, higher and lower temperatures are contemplated by the inventors.
[0038] (11) The invention herein disclosed contemplates treating precancerous lesions.
[0039] The herein disclosed invention contemplates treating various internal lesions with a low pressure cryogenic spray. Low pressure can be determined by routine experiment by those skilled in the art. The inventors have found a pressure of approximately 3-5 psi to be operative. In addition, pressures up to around 45 psi would be effective.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0040] [0040]FIG. 1 is a partially schematic overview showing use of the apparatus of the present invention.
[0041] [0041]FIGS. 1A, 1B and 1 C are enlarged views of the placement of the endoscope and catheter in the esophagus.
[0042] [0042]FIG. 2 is a perspective end view of an endoscope with a protruding catheter. Part of the endoscope and catheter have been broken off for ease of illustration.
[0043] FIGS. 3 - 5 are perspective views of alternate embodiments of the catheter tip.
[0044] [0044]FIG. 6 is a partial schematic view of the improved cryosurgical system.
[0045] [0045]FIG. 7A is a perspective view of a tank and valve arrangement used to deliver liquified gas to the catheter. Part of the tank has been broken away for ease of illustration.
[0046] [0046]FIG. 7B is a perspective view thereof with the tank turned 90°.
[0047] [0047]FIG. 8 is a top plan view thereof.
[0048] [0048]FIG. 9 is a perspective view of an electronic control box and printer.
[0049] FIGS. 10 A-F are views illustrating a combined catheter, bleeder vent and luer lock fitting attached to a solenoid valve fitting. The catheter has been broken away for ease of illustration.
[0050] [0050]FIG. 11 is a packet or kit containing a combined catheter, bleeder vent and luer lock fitting along with a nasogastric tube.
[0051] [0051]FIG. 12A is a schematic block diagram of the cryosurgical apparatus and process of the present invention.
[0052] [0052]FIG. 12B is a “closed loop” schematic block diagram of the cryosurgical apparatus and process of the present invention.
[0053] [0053]FIG. 13 is a flow chart describing the cryosurgical procedure.
[0054] [0054]FIGS. 14A and 14B are an electronic diagram of the processor and recorder.
[0055] FIGS. 15 A- 15 D are photographs of cryoablation performed and as exemplified in the Example set forth herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0056] Referring to FIG. 1, an apparatus and method for cryo-surgical ablation of Barrett's esophagus has an endoscope 10 inserted into the esophagus E, of a patient P, adjacent to the stomach S. Barrett's tissue B lines the esophagus E above the lower esophageal sphincter.
[0057] A conventional therapeutic endoscope 10 is illustrated in the drawings, although a smaller diagnostic endoscope is preferably used from the standpoint of patient comfort, particularly when a balloon shield is not being used. A specially designed endoscope can also be used. The distal end 12 of such an endoscope 10 is shown in FIG. 2, showing an imaging camera lens 14 , illuminating light 16 , biopsy channel (bore or lumen) 18 with the catheter 20 therein, and an additional lumen 22 . The image picked up at the lens 14 is transferred via fiber optics to a monitoring camera 25 (FIG. 1) which sends TV signals via a cable 26 to a conventional monitor 28 , where the procedure can be visualized. By virtue of this visualization, the surgeon is able to perform the cryosurgery in the esophagus.
[0058] Through the lumen 18 is disposed a catheter 20 , preferably a conventional TEFLON catheter size 7 FR of 2-3 mm outside diameter. The catheter 20 protrudes from the distal end 12 (i.e., the end first inserted into the esophagus) of the endoscope 10 and extends to the proximal end 30 (closest to the operator, outside the patient) where a physician's hand H 1 guides the catheter 20 . As seen in the monitor image 28 of FIG. 1, the distal end 12 of the catheter 20 may be bent at an angle.
[0059] The catheter 20 is coupled to a tube extending near the bottom of a Dewar flask 32 filled with liquid nitrogen or other liquified gas LG. As used in the present specification, “gas” in the phrase “liquified gas” means any fluid which is physiologically acceptable and which has a sufficiently low boiling point to allow the cryotherapy of the present invention. For example, such boiling point is preferably below about −150° C. The gas is preferably nitrogen, as it is readily available, or alternatively argon.
[0060] The Dewar flask 32 may be adapted from an ordinary commercial container such as a THERMOS bottle holding as little as a quart of liquid, which can readily be refilled from a larger container. Liquid nitrogen is also easily and safely handled in foam-insulated containers (e.g., STYROFOAM cups). However, the container 32 is preferably a medium-capacity stainless-steel Dewar flask of several liters capacity. A larger container, able to provide liquid for numerous operations over several weeks time, may be used. For expediency the large container may be mounted on a cart.
[0061] The Dewar flask 32 is closed and the interior space is pressurized with a small air pump 34 , which may alternatively be mounted in the container lid or elsewhere.
[0062] [0062]FIG. 1 shows schematically that the proximal end of the catheter 20 is coupled to a tube 35 , preferably by a standard luer lock 37 , and the lower end of the tube 35 is immersed in liquid nitrogen LG while the interior is pressurized by a free-running pressure pump 34 through a tube 38 . A pressure gauge 40 is preferably provided, or alternatively a safety valve with a preset opening pressure (not shown). The pressure is selected so as to permit adequate spray from the distal end of the catheter 20 . The interior of the Dewar flask 32 is vented through a vent tube 42 which is preferably opened and closed by a valve operated by the physician's hand H 2 . FIG. 1 shows the thumb obstructing the end of the vent tube 42 . When the vent is closed, pressure builds up in the Dewar flask 32 and nitrogen is pumped through the tube 35 to catheter 20 .
[0063] While the valve is shown as a simple thumb-valve in FIG. 1, it will be understood that such a valve could be a mechanical valve or an electromechanical valve, preferably controlled by a trigger mechanism, or the like, as could be readily envisioned and constructed by those of ordinary skill in the art. In a preferred embodiment of this invention, an electrically operated solenoid valve is employed in delivering the liquified gas to the catheter. Of course, the solenoid is specifically adapted to function properly at cryogenic temperatures.
[0064] The vent tube 42 is left open until the physician has positioned the catheter near the Barrett's tissue, as guided by the hand H 1 and confirmed by viewing the monitor 28 . The physician then closes the vent 42 and liquid nitrogen is pushed into the proximal end of the catheter 20 at the luer lock 37 .
[0065] As the liquid nitrogen moves through the catheter 20 , it starts to boil and cool gas rushes ahead to emerge from the distal end or catheter tip 46 . The amount of boiling in the catheter 20 depends on the mass and thermal capacity of the catheter. Since the catheter is of small diameter and mass, the amount of boiling is not great. (The catheter would preferably be “French Seven”.) After the catheter is cooled to a low temperature, and becomes filled with liquid nitrogen, the liquid nitrogen reaches the distal end of the catheter 20 near the distal end of endoscope 12 and begins to spray out of the catheter onto the Barrett's tissue. It is to be noted that the present invention may be able to freeze the Barrett's tissue sufficiently without actual liquid nitrogen being sprayed from the catheter, and that a spray of liquid may not be needed if the very cold gas can accomplish the task of freezing the epithelium.
[0066] Freezing is apparent to the physician by the frozen tissue B acquiring a white color (cryoburn), due to surface frost (visible on the monitor 28 in FIG. 1); the white color indicates gastrointestinal mucosal freezing sufficient to destroy the diseased tissue. The physician manipulates the endoscope 10 , vent 42 , and/or catheter 20 to freeze all of the Barrett's tissue. Once the operation is complete, the endoscope 10 with catheter are withdrawn.
[0067] The invention also contemplates valving the nitrogen at the distal end of the catheter, immediately adjacent the Barrett's tissue. Apparatus for such valving 53 , shown in FIG. 3 and discussed below, allows for control of the liquid nitrogen flow.
[0068] Since there is no gross damage to the esophagus (for example, there is no laceration), there is no need to treat the frozen area. The columnar cells of the Barrett's tissue soon die, and the lining is sloughed off to be replaced by healthy squamous tissue.
[0069] Because the invention uses liquid spray via a catheter 20 rather than contact with a cold solid probe, there no risk of a cold apparatus sticking to the esophagus and tearing the tissue. The plastic material of the catheter, such as TEFLON, is in little danger of sticking to the tissue because of its low thermal conductivity and specific heat. Furthermore, it is not designed to touch the tissue.
[0070] Using a catheter the cooling rate (rate of heat removal) is much higher than with a solid probe since the sprayed liquid evaporates directly on the tissue to be frozen, which absorbs the entire heat of vaporization. The rate of rewarming is also high, since the applied liquid boils away almost instantly. No cold liquid or solid remains in contact with the tissue, and the depth of freezing is minimal.
[0071] Since freezing is accomplished by boiling liquid nitrogen, large volumes of this gas are generated. This gas must be allowed to escape. The local pressure will be higher than atmospheric since the gas cannot easily flow out of the gastrointestinal tract; nitrogen gas will tend to enter the stomach S, whose junction with the esophagus (the esophageal sphincter) is immediately adjacent to the Barrett's tissue freezing zone. The present invention provides for the gas to escape by several alternate methods.
[0072] First, the stomach may be suctioned with a separate tube 41 . For example, a nasogastric tube 41 as seen in FIGS. 1A, 1B and 1 C, which preferably runs outside of and adjacent to the endoscope 10 . Suction may be provided by a suction pump 45 or other conventional means for suction.
[0073] Second, an escape path may be provided by an additional lumen in the endoscope. Additional lumens are provided on so-called “therapeutic” endoscopes. “Diagnostic” endoscopes typically have only one lumen, which would be occupied by the liquid nitrogen-delivery catheter 10 when such an endoscope is used in the present invention. The use of a two-lumen “therapeutic” scope in the present invention provides an extra lumen for use as an escape path for gas venting. The application of suction to such a vent lumen is also preferably provided.
[0074] The lower esophageal sphincter may be blocked with an inflatable balloon 43 (FIGS. 1A and 1B), or some other shield, to prevent nitrogen gas from inflating the stomach. The balloon 43 may be of the “TTS” (through the scope) type, passing through an additional lumen on the endoscope as is shown in FIG. 1. Alternatively, a balloon may be placed alongside the endoscope 10 , such as an achalasia balloon. A bulb 44 or some other means for inflating and deflating the balloon 43 , such as a hand pump, can be provided. This may optionally be used in conjunction with stomach suction.
[0075] [0075]FIG. 2 shows a catheter tip 46 fastened on the end of the catheter 20 and adapted to spray liquid nitrogen in a radial pattern through plural holes 47 between the surface and an interior space fed by the catheter 20 . The length of the tip 46 is preferably chosen so that the entire area of the Barrett's tissue is frozen at once without the need for manipulating the endoscope or catheter to freeze the Barrett's area in sequential increments. The tip 46 may be of rigid material such as metal or stiff plastic, preferably the latter. Alternatively, the entire endoscope and/or catheter may be moved up or down the esophagus to ensure that the entire Barrett's area is sprayed.
[0076] [0076]FIG. 2 also shows the distal end 12 of the endoscope 10 including a camera lens 14 , illuminating light 16 , biopsy channel or lumen 18 with the catheter 20 therein, and an additional lumen 22 . The endoscope shown in FIG. 2 is a conventional therapeutic endoscope. A diagnostic endoscope would lack extra lumen 22 .
[0077] Alternatively to FIG. 2, the catheter 20 itself may include a plurality of radial holes 49 and an end plug 50 (FIG. 5) to force the nitrogen to flow out of the radial holes. The end plug 50 is controlled by a wire (not shown). The catheter tubing, even though of plastic, becomes much more rigid at very low temperatures and approximates the stiffness of the separate tip 46 .
[0078] [0078]FIG. 3 depicts a wire-controlled end valve embodiment in which a tip 52 interacts with a disc 53 proximally controlled by the physician via a wire 54 running through the inside of the catheter 10 . The liquid nitrogen hits disc 53 and becomes atomized into a radial spray.
[0079] [0079]FIG. 4 shows an end 56 of the catheter 20 cut at an angle to deflect the spray to one side.
[0080] With reference to FIGS. 6 - 9 , a particularly elegant and preferred gas supply system 70 is described. In this system, a pressurized gas tank 72 is employed. A convenient size for the tank has been found to be a 5.5 liter tank, and of course larger (e.g. 35 liter) or smaller size tank or even a canister would be operative. The inventors have found a double walled insulated tank (not shown) to be convenient because with adequate insulation the very low temperature of the liquid nitrogen gas can be maintained over a long period of time. The inventors have found the optimum pressure for the liquified gas in the tank to be 22 psi. The inventors have found 22 psi to be operative but higher or lower pressures are also operative.
[0081] Tank 72 is equipped with a pressure building coil or tube 74 for maintaining pressure. This coil 74 consists of metal tubing running from inside the tank to outside the tank and returning back to inside the tank. The tube 74 in operation contains circulating liquid nitrogen. If the pressure in the tank 72 drops below acceptable levels, valve 75 to the tube 74 can be opened to circulate gas outside of tank 72 through the tube 74 . The nitrogen liquid in the tube outside the tank will be warmed and returned to the tank. This warmed nitrogen liquid will boost the head pressure in the tank 72 and allow for more rapid delivery of nitrogen liquid to the catheter. In the tube arrangement shown, the valve 75 is hand operated, however, the valve could be automatic and would start circulating liquid through the tube or a coil once the pressure drops to unacceptable levels in the tank and to stop circulating once the pressure returns to normal. With normal pressure maintained in the tank, liquified gas will be more rapidly expelled from the tank to the catheter. The force of gas expelled from the tank is a function of the temperature and pressure of the liquid nitrogen in the tank. Because of the large temperature differential between the ambient temperature and the temperature of liquid nitrogen, only a short length of tubing 74 is required.
[0082] The gas supply system 70 illustrated in FIGS. 6 - 8 has a tank 72 equipped with valves and gauges. The tank 72 is equipped with a head gas valve 77 for relieving head pressure and a liquid nitrogen valve 78 which is opened to allow liquid nitrogen to flow to the solenoid valve 80 and then to catheter 20 . There are safety relief valves 81 , 82 on the tank 72 which relieve at pressures greater than 22 and 35 psi, respectively. In addition, the tank is equipped with a head pressure gauge 83 and a liquid level gauge 84 .
[0083] The improved cryosurgical gas delivery system 70 has improvements which allow the physician to more accurately and comfortably deliver the cryogenic gas to the patient. The improved system 70 has a foot-pedal operated solenoid valve switch 86 (FIGS. 6 and 9). This foot-pedal operated solenoid valve switch 86 actuates solenoid 80 between the tank 72 and catheter 20 . The foot pedal 86 has the advantage of allowing the physician's hand to be free during cryosurgery. Note, for example, that the system with the Dewar flask (FIG. 1) requires the physician's thumb to close vent 42 to produce pressure in the Dewar flask causing nitrogen gas to flow. The improved tank 72 heating coil or tube 74 and foot-pedal operated solenoid switch 86 allows for quick delivery of adequate amounts for cryogenic spray to treat Barrett's esophagus or other tissue requiring cryoablation.
[0084] Referring to FIGS. 6 - 8 and 10 , an elegant design feature of the improved system 70 is the ability of the system to force super-cooled nitrogen gas through the catheter 20 at low pressure. This feat is possible because the improved system has an auxiliary bleeder vent or bleeder 88 positioned between the liquid nitrogen gas supply tank 72 and the catheter 20 . The bleeder is positioned at a point in-line where the internal diameter of the system (i.e., catheter) is significantly reduced. This bleeder vent is designed to eliminate the elevated pressure produced at the catheter caused by the reduced internal diameter of the catheter relative to the larger internal diameter of the tube supplying gas to the catheter; and by the volatilization of the liquid nitrogen to gas phase nitrogen. This bleeder 88 reduces pressure in the catheter 20 and at catheter tip 46 by venting gas phase nitrogen out the bleeder vent 88 . With this venting of gas phase nitrogen, liquid phase nitrogen exits the catheter tip 46 as a mist or spray at a pressure of approximately 3-5 psi compared with the tank pressure of approximately 22 psi. Improved embodiments of this invention do not require a bleeder vent.
[0085] As an exemplary embodiment the vent may simply be a piece of tubing attached to the liquid nitrogen supply by a “T” connection. As the liquid nitrogen makes its way from the tank 72 to the proximal end of catheter 20 , the liquid is warmed and goes to gas phase. This phase change creates additional pressure throughout the length of the catheter, but is especially important at the solenoid/catheter junction, where the diameter of the supply tube relative to the catheter lumen decreases from approximately 0.5 inches to approximately 0.062 inches, respectively. Note that, in order to force low pressure liquid/gas nitrogen through this narrow opening, either the pressure of the supplied nitrogen must decrease or the diameter of the catheter must increase. The inventors did not wish to employ a highly pressurized system, nor did they wish to enlarge the catheter diameter. Accordingly, the auxiliary bleeder 88 allows the liquid phase nitrogen to pass through this reduced diameter catheter without requiring modification of tank pressure or catheter diameter. Without a pressure bleeder vent, the pressure of gas leaving the catheter would be too high and have the potential for injuring the tissue of the gastrointestinal tract.
[0086] The pressurized tank can be provided with a bleeder or bleed-off to assure that the pressure of the cryogenic spray discharged from the tip of the catheter does not inadvertently injure the patient.
[0087] While a Dewar flask (FIG. 1) is illustrated and was used in the experiments reported below, it should be understood that the liquified gas source can be of any type. For example, a pressurized tank or a reservoir, such that the liquified gas is piped into a connecting site on the procedure room wall. The main requirement being that the liquified gas supply be controllable by the physician.
[0088] It is an important preferred feature of the present invention that the spray be conducted in such a manner as to allow constant visualization by the physician of the tissue treatment as it occurs. If the temperature of the lens at the proximal end of the endoscope drops precipitously at the start of the liquid nitrogen spray, the moist air of the esophageal environment or of the air of the catheter which has been blown out ahead of the nitrogen flow will condense on the lens, thereby obscuring the physician's view of the operative site. This can be substantially avoided by means of the suction pump 45 which will immediately suck out the moist air which is present prior to the arrival of the liquid nitrogen spray or cold nitrogen gas. Because of this pumping out of the moist air as the spray commences and the replacement with extremely dry nitrogen gas, substantial amounts of moisture will not form on the lens 14 during the procedure, allowing an excellent view of the operative site by the physician during the procedure.
[0089] This condensation effect is augmented by the fact that the catheter itself is preferably not wrapped in additional insulation. This causes the temperature of the nitrogen gas exiting the catheter at the distal end to be relatively high at the beginning of the spraying operation and gradually cooling as the catheter cools. Indeed, in the tests conducted in the esophagus of pigs discussed below in the Examples, often 10-20 seconds were necessary before significant freezing was seen through the endoscope. If the catheter is substantially insulated, the interior of the catheter will cool much more quickly as it will not be picking up heat from the outside. With this insulated catheter, it is to be expected that the liquid nitrogen would be sprayed onto the tissue almost immediately, causing much faster freezing and, thus, allowing less control on the part of the physician.
[0090] Another reason that the lens does not fog or frost in the present invention is that the esophagus is flushed out with nitrogen gas, which is extremely dry. The nitrogen gas is moisture free because the liquid nitrogen is condensed out of atmospheric gases at a temperature −197° C. colder than the temperature at which moisture is condensed out.
[0091] The combination of relatively warm, and completely dry nitrogen gas, together with suction flushes all moist air from the esophagus. As the temperature of the gas entering the esophagus falls, so does the surface temperature of the camera lens 14 . Ordinarily at that time the lens 14 would be cold enough to condense moisture and fog, however, since the esophagus is dried out (in contrast to its usual highly moist state) there is no moisture to condense. Thus, the lens 14 stays un-fogged and un-frosted and continues to provide a clear view of the operation. On the other hand, if the esophagus is not vented with suction and/or the esophagus is not preliminarily flushed with dry nitrogen gas (perhaps because the catheter is insulated, lowering its heat capacity, and/or the nitrogen delivery pressure is too high), then the lens is likely to fog or frost and the physician cannot operate effectively.
[0092] In order to deal with the moist air problem, there is supplied in the preferred embodiment of this invention a nasogastric tube 41 (FIGS. 1 and 1A- 1 C). During the cryosurgical procedure the nasogastric tube is inserted prior to inserting the endoscope 10 and catheter 20 . The nasogastric tube 41 , when connected to a pump 45 , can serve to evacuate moist air from the esophagus prior to cryosurgery. With moist air removed, the T.V. camera lens 14 is not obscured by fog and the physician can perform cryosurgery with an unobstructed view. Alternatively, if fogging occurs during cryosurgery, the nasogastric tube and pump can be used to evacuate the esophagus.
[0093] In the most preferred embodiment, the composition of the catheter or the degree of insulating capacity thereof will be selected so as to allow the freezing of the mucosal tissue to be slow enough to allow the physician to observe the degree of freezing and to stop the spray as soon as the surface achieves the desired whiteness of color (cryoburn). The clear observation results from the removal of the moist air and sprayed nitrogen by the vacuum pump; in combination with the period of flushing with relatively warm nitrogen prior to application of the spray of liquid nitrogen which is caused by the relative lack of insulation of the catheter. Preferably, the catheter has a degree of insulation which permits at least five seconds to pass from the time said means for controlling is opened to the time that liquified gas is sprayed onto the mucosa.
[0094] With reference to FIGS. 6, 9 and 12 , an electronic monitoring and recording system 90 is illustrated. The electronic components of the system 90 comprise a temperature sensor or probe 92 and timer 96 . Also connected to the monitoring and recording system 90 are the foot-pedal 86 for actuating the solenoid 80 and recording console 95 . In FIG. 6 an electric power cord 93 runs from solenoid 80 to control box 90 .
[0095] The temperature sensor 92 is thin and can be inserted into the esophagus beside the catheter 20 . In a preferred embodiment, the temperature sensor 92 and catheter 20 can be inserted separately or as an integral unit of sensor and catheter combined, or alternatively the sensor can be inserted through an extra lumen of the endoscope to come in contact with the tissue of the esophagus. The temperature sensor 92 sends temperature readings to the electronic monitoring and recording system 90 for processing and recordation.
[0096] The liquid gas flow is started by actuating solenoid foot-pedal 86 and ends with release of the solenoid foot pedal 86 . The electronic monitoring and recording system 90 records the times at which cryoburn starts and ends. Temperature in the context of time will be recorded for the cryosurgery. This recordation allows for better data acquisition and documentation.
[0097] There is an automatic cut-off if a time or temperature limitation is exceeded. In the event of a cut-off, the electronic monitoring and recording system can be reactivated by pushing the reset button 98 (FIG. 9). Current time and temperature readings are presented in the windows 99 as LED numbers. The windows in FIG. 9 will indicate total time 100 ; shut-down time 101 ; cryotime 102 ; cryotime set 103 ; and temperature 104 . Within the main console of the electronic monitoring and recording system 90 of FIG. 9 is a printing unit 95 which prints and records 95 the time and temperature during the cryoburn. Every event is recorded, e.g. time, on and off, temperature, etc. FIGS. 6 and 9 show alternative models of the electronic monitoring and recording system. The printed record 97 is shown in FIG. 9.
[0098] The electronic console can be preprogrammed to be patient specific.
[0099] The operating sequence of components used in carrying out applicant's process are described in FIGS. 12A and 12B. FIG. 12A describes the nitrogen source 72 , foot-actuated 86 solenoid valve 80 , electronic control box and printer 90 , endoscope 10 with catheter 20 and T.V. monitor 28 for treating a patient with Barrett's Syndrome. In FIG. 12B is shown a completely automated system with sensors and a microprocessor for performing cryosurgery. The completely automated system of 12 B is similar to the system of 12 A except that various sensors for temperature, time, etc. 92 send an output signal(s) to a microprocessor controller 90 to control the shut-down of the system if pre-set limits are exceeded or if pre-set conditions are not met.
[0100] The steps for performing the esophageal cryosurgical procedure are described in flow chart FIG. 13.
[0101] The electronic circuitry for the electronic monitoring and recording system 90 is described in FIGS. 14A and 14B.
[0102] The components or paraphernalia required to practice the method of the present invention may be packaged and sold or otherwise provided to health-care providers in the form of a kit. The kit is preferably sealed in a sterile manner for opening at the site of the procedure. The kit will include the catheter, having the spray means at one end, as well as a means for connecting the catheter to the source of liquified gas. This means for connecting may be a simple luer connection on the opposite end of the catheter from the spray means. However, the term “means for connecting said catheter to a source of liquified gas” is intended to include any other device or apparatus which allows the catheter to be connected to the gas source.
[0103] Many of the components of the cryosurgical system are conventional medical appliances. For example, the endoscope is a conventional medical appliance and would not necessarily have to be supplied as part of a kit. One of the components to be supplied in a kit or sterilized package is a combined catheter-bleeder vent.
[0104] With reference to FIGS. 10 A- 10 F and 11 , this invention envisions the catheter 106 at its proximal end being integrally provided with a pressure reducing bleeder vent 107 as a single unit. The unit can be attached to the gas supply tube through a luer lock 37 connection and can be supplied to the user in a sterile package or kit 108 (FIG. 11).
[0105] With reference to FIGS. 10 A- 10 F, there is schematically represented tube connector 109 for connecting a tube running from the liquid nitrogen supply tank 72 , to solenoid 80 . The solenoid has a connector fitting to which can be attached a vented catheter. The vented catheter comprises as an integral unit a connector fitting 37 attached to the solenoid 80 along with a vent 107 between the connector 37 and the catheter 106 .
[0106] The catheter and bleeder unit can be supplied with various modifications in the placement of the bleeder vent relative to the catheter. In addition, envisioned are a variety of reductions between the solenoid valve and the catheter. For example, FIGS. 10 A- 10 C show that the actual position of the Bleeder relative too the catheter is open to design options. FIGS. 10 A- 10 F show a blunt reduction (i.e., reduction occurs just before the catheter). FIGS. 10 D- 10 F depict a tapered reduction (i.e. the diameter is reduced gradually over the entire length). Another option would include stepping reductions. In addition, the inventors contemplate that the vent can have a piece of tubing attached to lead away gas and the placing of a strainer (similar to a colander) inside of the tubing from the solenoid to the catheter. This strainer would serve as a mechanical means for separating the liquid phase from the gas phase.
[0107] Note particularly that the solenoid valve is specially designed to accept cryogenic gases and is commercially available.
[0108] Referring to FIG. 11, the inventors envision supplying the catheter and vent unit 105 as a separate item. In this way, the unit can be supplied in a sterile packet or kit 108 to be used with existing equipment found in hospital operating rooms. The kit may contain a nasogastric tube 41 .
[0109] The means for controlling the flow of liquified gas to the catheter is also preferably present in the kit and may be connected to or may be part of the means for connecting the catheter to the source of liquified gas. For example, the connector may contain a valve therein or the valve may be a separate element connected between the connector and the catheter or between the connector and the nitrogen source.
[0110] The endoscope may either be part of the kit or an available conventional endoscope may be used in conjunction with the remaining components of the kit.
[0111] The kit will also optionally contain the means for withdrawing gas, such as a tube and a means connectable to the tube for withdrawing gas from the tube. Such means connectable to the tube for withdrawing gas may be a vacuum pump or any other device or apparatus which will accomplish the function of withdrawing gas from the tube. The vacuum pump is optionally omitted from the kit as a source of vacuum is often found in hospital rooms in which such a procedure is to take place.
[0112] The means for blocking the lumen is also optionally present within the kit. Thus, for example, the kit may contain a balloon catheter or any other device or apparatus which can accomplish the function of blocking the lumen when in use.
[0113] The term “container” or “package” when used with respect to the kit is intended to include a container in which the components of the kit are intended to be transported together in commerce. It is not intended to comprehend an entire procedure room in which the individual components may happen to be present, an entire vehicle, a laboratory cabinet, etc. The claimed “means for causing fluid flowing therethrough to be sprayed in a radial direction” is intended to comprehend the illustrated embodiments of catheter tips shown in FIGS. 2 - 5 , as well as any functional equivalents thereof. Any device which can be connected to the end of a catheter which will direct fluid in the catheter to be sprayed substantially radially may be used. The terminology “a radial direction substantially perpendicular to the axis of the catheter” is intended to include a unidirectional spray over a small arc in the radial plane or an omnidirectional spray through 360° of the radial plane, or any arc therebetween. The term “substantially perpendicular” is not intended to limit direction of the spray to a plane at an angle of 90° to the axis of the catheter but to include any type of spray which will allow the mucosa of the lumen, such as the esophagus which is coaxial to the catheter to be sprayed, near the locus of the tip of the catheter and to exclude a spray which is only substantially axial. The claimed “means for controlling the flow of liquified gas” is intended to encompass the simple thumb-valve illustrated in FIG. 1, as well as any other mechanical, mechano-electrical, etc., device that will accomplish the function of controlling the flow of liquified gas from the source to the catheter. This includes any type of valve, including, for example, a trigger valve, a rotary valve, a stopcock, etc. The valve may be manually controlled, electrically driven, remotely controlled, etc. Other means for controlling the flow of liquified gas are not excluded.
[0114] The claimed “means for withdrawing gas” is intended to include the illustrated tube 41 and vacuum pump 45 , as well as any functional equivalent thereof. It does not matter whether the tube withdrawing the gas passes through the endoscope, around the endoscope, or even is placed into the area from which gas is to be withdrawn by incision. The only important function is the withdrawal of the gas from the area in question. While a vacuum pump is preferred, any other type of pump or device which will cause the withdrawal of the gas is intended to be encompassed by this terminology. Other means for withdrawing gas are not excluded.
[0115] The claimed “means for blocking the lumen” is intended to encompass not only the balloon catheter 43 and the shield of FIG. 3, but also any other device or technique which will accomplish the function of blocking the lumen, e.g., the esophagus when the condition being treated is Barrett's esophagus. Any manner of substantially preventing the gas being sprayed through the catheter from passing beyond the point of blockage is intended to be included by this terminology, including, for example, physically squeezing the lumen from the outside or chemically causing the lower esophageal sphincter to close, etc.
[0116] The claimed “means for forcing said liquified gas” is intended to include not only the illustrated pressure pump 34 but any other device or apparatus which will force the liquified gas from its source to the catheter. This includes use of a pre-pressurized container of liquified gas or apparatus which causes gas to liquify and then be directly directed to the catheter, etc. No manner of driving the liquified gas from the source to the catheter is intended to be excluded.
[0117] Each of the steps set forth in the method claims herein are likewise intended to comprehend not only the specific acts described in the specification but any other acts which will accomplish the function set forth in the method step. Thus, for example, the step of adjusting the catheter may be accomplished by hand, as illustrated in FIG. 1, or by any other technique up to and including use of a complicated remote controlled robotic adjusting apparatus. The same is true for all of the other method steps for performing specified functions.
[0118] The inventors have concluded from preliminary test results that a 30 second “cryoburn” time was adequate to ensure the appropriate tissue destruction, and thus appropriate cellular healing of damaged tissue (this conclusion was based on a 30 day follow up period). “Cryoburn” is a term defined by the instance that the normally “pinkish” esophageal tissue turns white (much like freezer burn). A range for the “cryoburn” time could be 5-10 seconds to 2 minutes or more depending on the substrate to be treated.
[0119] Due to the nature of the system, “cryoburn” does not immediately occur, but rather requires that the entire fitting and catheter system become cool. Typically this required approximately 20-30 seconds from the time that the solenoid foot pedal is depressed, and liquid nitrogen is allowed to flow from the tank.
[0120] During animal testing the approximate temperature that cryoburn was first observed was at approximately −10 degrees C. The temperature range for cryoburn would be approximately −10 to −90 degrees C.
[0121] In carrying out the procedure, a nasogastric tube is first inserted into the esophagus, after which an endoscope is inserted. The endoscope is supplied with light and fiber optic T.V. camera. Optionally, attached to the endoscope will be a temperature probe to sense the temperature and report the temperature to the recording console. Once the nasogastric tube, endoscope and temperature probe are in place, the catheter attached to the gas supply will be inserted into a lumen of the endoscope. Before liquid gas is supplied, the esophagus is ventilated using the nasogastric tube to remove moist air from the esophagus (if required). With the moisture evacuated and the endoscope is properly positioned, gas can be supplied to the catheter by actuating the solenoid with foot pedal. Once the solenoid is actuated gaseous nitrogen and then a spray of liquid nitrogen will come from the tip of the catheter. The cryoburn will generally last for 30 seconds to 2 minutes.
EXAMPLE
[0122] The cryospray device of FIG. 1 was used in experiments to assess the efficacy and safety of this device in mucosal ablation in the distal esophagus of swine. The catheter 20 was a long 7Fr ERCP-like catheter placed through the biopsy channel of an Olympus GIF-100 endoscope. The swine were sedated using telazol and xylazine given intravenously. General anesthesia was not necessary. Liquid nitrogen was sprayed on the distal 2 cm of the esophagus in 16 swine under direct endoscopic observation until a white “cryo-burn” appeared, usually within 10-20 seconds. FIG. 6 shows a photograph through the endoscope during such a procedure. Duration and location of the spray were varied to assess histologic response and depth of “cryo-burn”. The swine were then re-endoscoped on days 2, 7, 14, 21 and 30 to obtain biopsies from the injury site, assess mucosal ablation and re-epithelialization. All swine were then euthanized and underwent necropsy.
[0123] Freezing of the esophageal mucosa was recognizable by a white “cryo-burn” with sharply demarcated margins. This was followed by slow thawing within minutes and then mucosal erythema. Sixteen swine underwent hemi-circumferential to circumferential cryotherapy of their distal esophagus varying the duration of “cryo-burn” from 10-60 seconds. Blistering and sloughing of the superficial mucosa occurred within 2 to 7 days of the cryospray. Mucosal damage occurred only at the cryo site. Biopsies 48 hours after cryospray consistently demonstrated coagulative necrosis involving the mucosal layer and biopsies 30 days after cryospray consistently demonstrated complete re-epithelialization of the injured area. Complications included one esophageal stricture and one esophageal perforation in experiments with prolonged cryo-burn.
[0124] These experiments on living swine, which are a valid model of the human esophagus, establish that cryotherapy spray of liquid nitrogen via upper endoscopy is a simple technique capable of inducing controlled superficial mucosal damage with complete healing in the esophagus.
[0125] Photographs (FIGS. 15 A- 15 D) are exemplary of the cryogenic treatment of this invention. Note that the cryospray does not obscure the view of the esophagus. In addition, the cryospray, while producing a cryoburn, does not perforate the esophagus.
[0126] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means and materials for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention. Thus the expressions “means to . . . ” and “means for . . . ” as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure may now or in the future exist for carrying out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above; and it is intended that such expressions be given their broadest interpretation.
[0127] The inventors have continued to make improvements to their invention regarding use of low pressure, heated catheter, etc.
[0128] Prior Art Patents
[0129] Lee in U.S. Pat. No. 3,298,371 teaches a freezing probe to be used in neurosurgery. Attached to this freezing probe is a heater. This heater is provided in the event the insulation on the exterior of the probe is inadequate to thermally isolate non-target tissue surrounding the probe. In this way, non-target areas will not be affected by the cold, and only the cold probe tip will be presented to the target area.
[0130] Thomas U.S. Pat. No. 3,507,283 shows a cryosurgical probe which employs heating wires along the external surface of the instrument. Also shown by Thomas is a cover of heat shrinkable polytetrafluoroethylene to protect the user's hand from the cold.
[0131] Chang in U.S. Pat. No. 5,400,602 teaches various types of plastic materials used for cryotubing which remain flexible during use.
[0132] Griswold U.S. Pat. No. 5,658,276 teaches a cryoprobe with a heated exterior so that areas of the body not being treated by the probe are not damaged by the cold instrument. The heat is produced by a battery-energized resistive wire wrapped around the external surface of the probe.
[0133] U.S. Pat. No. 5,800,488 to Crockett teaches a cryoprobe wherein different methods are used to heat the external surface.
[0134] The inventors have continued to make improvements to their invention. They have produced a heated catheter. The heated catheter in a preferred embodiment is a composite constructed of three different materials; in three different layers. The catheter itself (as the first layer) is made of extruded polyimide. Surrounding the first layer (the catheter) is a layer of magnetic wire wrapped around the outer diameter of the polyimide catheter. As a top or final layer, there is supplied a thin polyester heat shrink.
[0135] More specifically, the heated catheter (cryocatheter) can be defined as an extruded polyimide tube (O.D. 0.092″). Over the catheter is wrapped a layer of magnetic copper wire (0.007″ diameter). A number of different diameter wires are available. The inventors put together prototypes with 0.003″ diameter wire, 0.002″ diameter wire, 0.005″ diameter wire, etc. A 0.007″ diameter wire was the best for the desired voltage, but the invention does not exclude the use of wires of other diameters.
[0136] The wrappings of wire that functioned the best were 8 wraps per inch (a single strand was run the length of the catheter, and the wrapping was applied back over this single strand to complete the electrical loop. Double strand wrapping with the wrap spacing (up to 25 wraps per inch) would be operative.
[0137] A selected preferred voltage for application is 12 volts and 1 amp. Voltages of 5, 12, 17 and 24 volts have been tested. The important thing to keep in mind is that different diameter wires work well if wrapped to the correct density and heated with the appropriate amount of voltages.
[0138] The final layer employed is a thin (0.00025″) polyester heat shrink. This heat shrink serves to hold the wire in place and to seal the wire from patient contact.
[0139] The hub, or connection of the catheter to the cryo-system, has been designed to incorporate the electrical contacts required by the heating system.
[0140] Advantages of the Heated Catheter
[0141] The heated catheter provides a number of advantages over a traditional catheter:
[0142] Polyimide, the Cryo-catheter material base, acts as a strong insulator and transports the liquid nitrogen with minimal thermal temperature loss resulting in a shorter time to achieve the clinically required cryoburn.
[0143] The heating mechanism allows the catheter to be removed from the endoscope lumen immediately following the cryo-therapy. Using a traditional catheter, the catheter is frozen into the endoscope lumen for 30-40 seconds following the therapy. This freezing to the endoscope lumen may result in damage to the endoscope.
[0144] In an embodiment of the invention, the bleeder valve has been found to be unnecessary so long as low pressure can be maintained by other means. In the improved embodiment, a cryoburn is carried out without the need for a bleeder valve. In this new embodiment with the tank pressure at 45 psi and the catheter being a 9 french, the cryo-procedure took 4 minutes and 50 seconds. With a 10 french catheter using 45 psi, the cryo-procedure took 2 minutes and 50 seconds to achieve a cryoburn temperature. With the bleeder valve, it takes 10-20 seconds to achieve cryoburn. The ideal low pressures operative for this invention should be in the range of 3-45 psi. The most ideal pressure is determinable by those skilled in the art.
[0145] It is clear from experiments performed that a bleeder valve is not absolutely essential to this invention since low pressure cryoablation can be carried out through low head pressure in the storage tank or through selection of the proper inner diameter of the catheter. Based on experiments carried out with the bleeder valve embodiment a shorter time period is required for cryoburn.
[0146] Insulated Fittings
[0147] The new fittings on the device will be vacuum insulated. This will keep the fittings from frosting or feeling super cool to the human touch.
[0148] In addition, the hub or connective fittings which couple the catheter to the cryosystem have been redesigned and improved to accommodate electrical contacts required for the heating system.
[0149] The inventors have continued to make improvements to their cryogenic heated catheter. Among the improvements contemplated by the inventors is the heating coil on the heated catheter being energized in “series” or that the catheter is heated with a continuous length energized from two ends. Also contemplated is a catheter with the heating element in parallel. This will result in heating short segments (5-10 segments per catheter) quickly and with more energy.
[0150] The inventors may adjust the wrappings of the heating coil so that the loops touch one another. A parallel electrical transfer may be necessary.
[0151] It may be feasible to employ flat wire (square wire) as opposed to round wire. Whether to use series or parallel spacing will be determined based on individual use.
[0152] The inventors contemplate coating the gap between the wires with a heat sink which will act to absorb radiated heat from the heating coil to dispense the heat to the outside of the catheter.
[0153] Also contemplated by the inventors is a spray coat or liquid paint of a nichrome conductor. In this embodiment the entire catheter could be energized quite quickly.
[0154] The inventors envision alternate means for diverting freezing temperatures from non-target areas. Examples of such diverting means is a polystyrene tape to function as an insulator. Alternatively, the catheter may be made of polystyrene or some other insulating material.
[0155] During the cryoburn the heat of the catheter remains active This prevents the accidental injury to non-target tissue.
[0156] Obviously, many modifications may be made without departing from the basic spirit of the present invention. Accordingly, it will be appreciated by those skilled in the art that within the scope of the appended claims, the invention may be practiced other than has been specifically described herein. | A method and apparatus to treat Barrett's tissue, a pre-cancerous condition, by removing the epithelium above the lower esophageal sphincter through cryo-ablation. An endoscope with fiber optics is used to view the operation, and a catheter for supplying liquid nitrogen is passed through the lumen of the endoscope. Liquid nitrogen at low pressure is sprayed directly onto the Barrett's tissue through the catheter while the physician views the operation through the fiberoptics of the endoscope and controls the spray via a valve. Freezing is indicated by whiteness and shows that the epithelium has been cryoablated. The apparatus can also be used to treat various other gastrointestinal tract lesions. The catheter is insulated to withstand extremely cold temperatures without becoming stiff and without affecting the inherent flexibility and maneuverability of the endoscope. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to latching mechanisms, particularly to a latching mechanism employed in an electronic device.
[0003] 2. Discussion of the Related Art
[0004] Components of electronic devices are generally protected by a housing. The housing surrounds or encloses the electronic parts to be protected. Most housing are not a single integral body but are several parts assembled together by latching mechanisms to form an integrated unit. If the latching mechanisms are easily detachable from the housing the protection offered by the housing may be compromised.
[0005] A typical latching mechanism used in electronic devices may includes screws or nuts and bolts for connecting the housings together. However, the screws or nuts and bolts are unsightly and may affect the overall appearance of the electronic device. In addition, assembly efficiency is low because the screws or nuts and bolts should be assembled one by one. Furthermore, the housings of the electronic device can be detached from each other easily because of easy access to the screws and the nuts and bolts and any visible indication of this intrusion may not be possible. Thus, the electronic device can be disassembled and valuable intellectual property can be duplicated or copied easily.
[0006] Therefore, a latching mechanism, for housings of electronic devices, which is easy to assembly, and thereby reducing assembling time, and difficult to be detached from an electronic device without damaging components and/or the latching mechanism is desired.
SUMMARY
[0007] An exemplary latching mechanism for connecting a first component and a second component. The latching mechanism for the first and second components includes an engaging portion formed/defined on the second component, a latch holder fixed relative to the first component, and a first latching member. A first latch-clasping piece extends from the latch holder. The first latching member has a second engaging portion. The second engaging portion engages with the first engaging portion of the second component. The first engaging portion of the second component and the first latching member are disposed between the first latch-clasping piece of the latch holder and the first component. The present invention further provides an electronic device employing the latching mechanism.
[0008] Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present latching mechanism. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views, and all the views are schematic.
[0010] FIG. 1 is an exploded, isometric view of a latching mechanism for housings of an electronic device connected by the latching mechanism of the present invention.
[0011] FIG. 2 is an isometric view of a first housing of the electronic device of FIG. 1 .
[0012] FIG. 3 is an exploded, isometric view of the latching mechanism of FIG. 1 .
[0013] FIG. 4 is an assembled, isometric view of the latching mechanism and the housings of FIG. 1 .
[0014] FIG. 5 is a side cross-sectional view of the latching mechanism connecting the housings along line V-V of FIG. 4 .
[0015] FIG. 6 is an enlarged view of a position VI of FIG. 5 .
[0016] FIG. 7 is an enlarged view of a position VII of FIG. 5 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] The present invention provides a latching mechanism. The latching mechanism is usually employed in electronic devices such as mobile phones, personal digital assistants, and laptop computers. The electronic devices include two housings that need to be connected together. It can be understood that the latching mechanism may also be used to connect two other components other than housings.
[0018] Referring to FIG. 1 , the latching mechanism used to connect a first housing 20 and a second housing 40 includes latch holders 60 a , 60 b , and first latching members 80 a , 80 b.
[0019] Also referring to FIG. 2 , the first housing 20 is approximately a rectangular-shaped member. The first housing 20 includes a bottom base 202 , two first sidewalls 204 extending perpendicularly from two opposite sides of the base 202 , and two second sidewalls 206 extending perpendicularly from another two opposite sides of the bottom base 202 . The second sidewalls 206 are joining to the first sidewalls 204 correspondingly, and the second sidewalls 206 are perpendicular to the first sidewalls 204 . A slot 208 is defined in each of the first sidewalls 204 from an inner side of the first sidewalls 204 . The first housing 20 may be other shapes different from a rectangle.
[0020] The second housing 40 is approximately a rectangular-shaped frame. The second housing 40 includes two first rims 402 disposed at two opposite sides of the housing 40 and two second rims 404 disposed at another two opposite sides. The second rims 404 are joining to the first rims 402 correspondingly, and the second rims 404 are perpendicular to the first rims 402 . A second latching member 406 extends from each of the first rims 402 , and at least one hooking member 408 extends from each of the second latching member 406 . The at least one hooking member 408 extends outwards of the second housing 40 perpendicularly. In the embodiment, three hooking members 408 extend from each of the second latching members 406 .
[0021] Referring to FIG. 1 and FIG. 3 , the latch holder 60 a includes a main portion 602 , a first latch-clasping piece 604 , and a plurality of second latch-clasping pieces 606 spaced from each other in a first predetermined manner. In the embodiment, the latch holder 60 a includes two second latch-clasping pieces 606 . The main portion 602 is an elongated strip. The first latch-clasping piece 604 extends from a lateral edge of the latch holder 60 a . The second latch-clasping pieces 606 extend from another lateral edge of the latch holder 60 a opposite to the first latch-clasping piece 604 and on a same side of the latch holder 60 a . The first latch-clasping piece 604 is an elongated strip. An interspace 609 is defined between the first latch-clasping piece 604 and the second latch-clasping pieces 606 . A groove 610 is defined in each second latch-clasping piece 606 .
[0022] The first latching member 80 a includes a base 802 and a plurality of resilient members 804 spaced apart from each other in the first predetermine manner corresponding the second latch-clasping pieces 606 . In the embodiment, the first latching member 80 a includes three resilient members 804 . The base 802 is an elongated strip. Each of the resilient members 804 extends from a side of the base 802 and immediately forms a 180 degrees U-shaped bend relative to the base 802 . A clearance 807 is defined between the base 802 and the resilient members 804 . An end of each resilient member 804 is bended slightly towards a direction of the base 802 , thereby forming a resilient slider 805 . A hook catch hole 806 is defined in each of the resilient members 804 . The first latching member 80 a is elastic so that the resilient members 804 can bend slightly towards to or away from the base 802 under an external force.
[0023] Referring to FIGS. 3-6 , when assembling the first and second housings 20 , 40 together, firstly, the latch holder 60 a and the first latching member 80 a is aligned next to each other such that the base 802 of the first latching member 80 a is received in the groove 610 of the latch holder 60 a , and the resilient members 804 of the first latching member 80 a are received in the interspace 609 of the latch holder 60 a and correspond to the grooves 610 . Then the latch holder 60 a and the first latching member 80 a are disposed at an internal side of one of the first sidewalls 204 of the first housing 20 . The base 802 of the first latching member 80 a is adjacent to the first sidewall 204 and received in one corresponding slot 208 of the first housing 20 . Next, the latch holder 60 a is fixed to the first housing 20 . In this embodiment, the latch holder 60 a is fixed to the first housing 20 by adhesive. However, the latch holder 60 a may also be fixed by other means such as bolts or rivets. Finally, the second housing 40 is coupled to the first housing 20 such that the second latching members 406 of the second housing 40 and the hooking members 408 on the second latching member 406 enter a space defined between the first latch-clasping piece 604 correspondingly. The resilient sliders 805 guides the hooking members 408 and substantially deform the resilient members 804 as a whole by a pushing force of the hooking members 408 on the second housing 40 . When the second housing 40 is pushed into a certain position such that the second latching member 406 is at a certain position of the space between the first latch-clasping piece 604 and resilient members 804 correspondingly, the hooking members 408 of the second housing 40 are hooked in the hook catch hole 806 . The resilient members 804 of the first latching member 80 a returns to a normal form at rest. Thereby, the second housing 40 is securely coupled to the first housing 20 .
[0024] Referring to FIG. 3 , a structure of the latch holder 60 b is similar to that of the latch holder 60 a , and a structure of the first latching member 80 b is similar to that of the first latching member 80 a . Referring to FIG. 6 and FIG. 7 , engagement mechanisms of the latch holder 60 b and the first latching member 80 b are the same as the engagement mechanisms of the latch holder 60 a and the first latching member 80 a . The latch holder 60 b and the first latching member 80 b engages with another first sidewall 204 of the first housing 20 and another second latching member 406 of the second housing 40 in a same manner as the latch holder 60 a and the first latching member 80 a engaging with the first and second housings 20 , 40 . After assembly, the latch holders 60 a , 60 b , the first latching members 80 a , 80 b , the slots 208 of the first housing 20 , and the hooking members 408 of the second housing 40 cooperatively connect the first and second housings 20 , 40 together. The hooking members 408 of the second housing 40 and the first latching members 80 a , 80 b are set between the first housing 20 and the latch holders 60 a , 60 b fixed to the first housing 20 and are not exploded. Therefore, an engagement between the second housing 40 and the first latching members 80 a , 80 b cannot be disassembled without damaging any components of the first and second housings 20 , 40 , the first and latch holders 60 a , 60 b , or the first and first latching members 80 a , 80 b . It can be seen that the first and second housings 20 , 40 cannot be disassembled without damaging such components.
[0025] Alternatively, other catching mechanisms can be formed on the first and second housings 20 , 40 in order to connect the first and second housings 20 , 40 more securely. The first latching members 80 a , 80 b may also be fixed on the first housing 20 . The latch holders 60 a , 60 b and the first latching members 80 a , 80 b can be integrally formed with the first housing 20 . The hooking members 408 may extend from the first latching members 80 a , 80 b , and the hook catch hole 806 is defined in the second housing 40 correspondingly.
[0026] It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention. | An exemplary latching mechanism for connecting a first component ( 20 ) and a second component ( 40 ). The latching mechanism includes at least one first engaging portion ( 408 ) formed/defined on the second component, at least one latch holder ( 60 a , 60 b ) fixed relative to the first component, and at least one first latching member ( 80 a , 80 b ). A first latch-clasping piece ( 604 ) extends from the at least one latch holder. The at least one first latching member has at least one second engaging portion ( 806 ). The second engaging portion engages with the first engaging portion of the second component. The first engaging portion of the second component and the first latching member are disposed between the first latch-clasping piece of the latch holder and the first component. The present invention further provides an electronic device employing the latching mechanism. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to human interfaces, inventory, and retailing sales, including point-of-sale terminals and, in particular, to libraries, tool cribs, and any other place where customers or end-users remove items from inventories and inventories need to be monitored.
[0003] 2. Description of Related Art
[0004] Radio frequency identification (RFID) is a technology that incorporates the use of electromagnetic or electrostatic coupling in the radio frequency (RF) portion of the electromagnetic spectrum to uniquely identify an object, animal, or person. RFID is coming into increasing use in industry as an alternative to the bar code. One advantage of RFID over the bar code is that it does not require direct contact or line-of-sight scanning. An RFID system typically consists of three components: an antenna and transceiver (often combined into one reader) and a transponder (tag). The antenna uses radio frequency waves to transmit a signal that activates the transponder. When activated, the tag transmits data back to the antenna. The data is used to notify a device, such as a programmable logic controller that an action should occur. The action could be as simple as raising an access gate or as complicated as interfacing with a database to carry out a monetary transaction. There are various kinds of RFID systems, including low frequency and high-frequency systems. Low-frequency RFID systems (30 KHz to 500 KHz) have short transmission ranges (generally less than six feet). High-frequency RFID systems (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) offer longer transmission ranges (more than 90 feet). In general, the higher the frequency, the more expensive the system is. RFID is sometimes called dedicated short-range communication (DSRC).
[0005] Much check-out work either in libraries or stores today is mindless work where the librarian or cashier simply scans books or inventory items that the customer has chosen. The customer, in turn, often swipes an ID card or credit card in order to acquire this inventory. There is a need to automate more of the mindless work using computing devices and RFID transceivers. Furthermore, there is a need to physically move the work to where it is mostly naturally likely to take place, either in a static location, such as at an exit, or dynamically in specialized shopping carts or with specialized mobile cell phones.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention is directed to methods, computer-readable mediums, systems, shopping carts, cell phones, and exit areas for interaction with inventory that satisfies these needs and others.
[0007] A first aspect is a method for interaction with inventory. An inventory RFID tag and a personal RFID tag are read in proximity to an RFID reader. The inventory RFID tag identifies an inventory item and the personal RFID tag identifies a personal item. The inventory item is associated with the personal item. The inventory item is checked out to the personal item.
[0008] Another aspect is a computer-readable medium having instructions for performing a method of interaction with inventory. An inventory RFID tag and a personal RFID tag are read in proximity to an RFID reader. The inventory RFID tag identifies an inventory item and the personal RFID tag identifies a personal item. The inventory item is associated with the personal item. The inventory item is checked out to the personal item.
[0009] Yet another aspect is a system for interaction with inventory that includes one or more inventory items, a check-out system, and one or more exit areas. The inventory items have inventory RFID tags. The check-out system includes at least one RFID reader. The RFID reader reads the inventory RFID tag and a personal RFID tag on a personal item. The check-out system associates the personal item with the inventory items when they are in proximity to the RFID reader. The exit areas are in communication with the check-out system. The exit areas allow passage of the person interacting with the inventory in response to a signal from the check-out system.
[0010] Still another aspect is a shopping cart for interaction with inventory that includes a holder and a list-making component. The holder receives at least one acquired item from a plurality of inventory items having inventory RFID tags. Acquired items have been read by an RFID reader. The list-making component creates and maintains an interim list of the at least one acquired item. The list-making component also provides a final list for reconciliation. The interim list associates the acquired item with a personal item having a personal RFID tag. The personal RFID tag is read by the RFID reader.
[0011] Still another aspect is a cell phone for interaction with inventory. The cell phone includes a list-making component and an RFID reader. The list-making component creates and maintains an interim list of acquired items from a plurality of inventory items having inventory RFID tags. The list-making component also provides a final list for reconciliation. The interim list associates at least one inventory item having at least one inventory RFID tag with a personal card having a personal RFID tag. The RFID reader reads the inventory RFID tag and the personal RFID tag, when the inventory RFID tag and the personal RFID tag are in proximity to the RFID reader.
[0012] Still another aspect is an exit area for interaction with inventory. The exit area includes an RFID reader, a check-out component, and a sensor. The RFID reader reads a personal card having a personal RFID tag and at least one inventory item having at least one inventory RFID tag, when the personal card and the at least one inventory item are in proximity to the RFID reader. The check-out component automatically checks-out the inventory item to the personal card, after the personal RFID tag and the inventory RFID tag are read by the RFID reader. The check-out component is in communication with the RFID reader. The check-out component receives information associated with the personal card and the inventory item from the RFID reader. The sensor operates at least one exit way upon receiving a signal from the check-out component. The sensor is in communication with the check-out component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, where:
[0014] FIG. 1 is a block diagram showing an exemplary method for interaction with inventory;
[0015] FIG. 2 is a block diagram showing another exemplary method for interaction with inventory;
[0016] FIG. 3 is a block diagram showing an exemplary computer-readable medium having instructions for performing a method of interaction with inventory;
[0017] FIG. 4 is a block diagram showing an exemplary system for interaction with inventory;
[0018] FIG. 5 is a block diagram showing an exemplary shopping cart for interaction with inventory;
[0019] FIG. 6 is a block diagram showing another exemplary shopping cart for interaction with inventory;
[0020] FIG. 7 is a block diagram showing an exemplary cell phone for interaction with inventory; and
[0021] FIG. 8 is a block diagram showing an exemplary exit area for interaction with inventory.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 shows an exemplary method for interaction with inventory. An inventory RFID tag 100 and a personal RFID tag 102 are read by an RFID reader 104 . The inventory RFID tag 100 identifies an inventory item 106 and the personal RFID tag 102 identifies a personal item 108 . At 110 , the inventory item 106 is associated with the personal item 108 and, then at 112 , the inventory item 106 is checked-out to the personal item 108 .
[0023] Many different kinds of RFID tags 102 , RFID readers 104 , and other RFID technologies may be used in embodiments of the present invention to operate in shopping carts, cell phones, exit or entry areas of a facility, and in various other ways.
[0024] Various embodiments of the present invention operate, at least in part, according to standards, such as JTC 1/SC 31 Automatic identification and data capture techniques, JTC 1/SC 17 Identification Cards and related devices, ISO TC 104/SC 4 Identification and communication, ISO TC 23/SC 19 Agricultural electronics, CEN TC 278 Road transport and Traffic Telematics, CEN/TC 23/SC 3/WG 3 Transportable Gas Cylinders—Operational Requirements—Identification of cylinders and contents, ISO/TC204 Transport Information and Control Systems, European Telecommunications Standards Institute (ETSI), European Radiocommunications Office (ERO), American National Standards Institute (ANSI), Universal Postal Union, and American Society for Testing and Materials (ASTM), among other standards.
[0025] Personal items 108 include, for example, a retail store customer card, a credit card, a debit card, a smartcard, a library card, a computing device, a cell phone, and many other kinds of cards and devices associated with inventory, customers, retail, leasing and the like. One advantage of having the personal RFID tag 102 on, for example, an identification card is that a person carrying the identification card need not take the identification card out for it to be read by the RFID reader 104 . In one embodiment, the personal item 108 is read upon entry to a facility and, then, upon exit associated with at least one inventory item 106 .
[0026] There are several exemplary ways the personal item 108 , such as an identification card, can be associated with the inventory item 106 . First, the personal item 108 and the inventory item 106 can be associated with each other because they are in proximity to each other during one or more readings by the RFID reader 104 . For example, when a person carrying the personal item 108 and the inventory item 106 approaches the RFID reader at an exit area, the RFID reader reads them both and associates them. If the person is carrying a plurality of personal items 108 , a computing machine can provide a selection by the person. If a specific type of personal item 108 is required by the facility, say a library card, then that one can be selected automatically from among a number of personal items 10 by the computing machine and optionally confirmed by the person.
[0027] A second exemplary way the personal item 108 can be associated with the inventory item 106 is through a shopping cart that is specially adapted to recognize particular events. An event is recognized, for example, when the inventory item 106 is placed in the cart and the inventory item is associated to the personal item, in response to the event. Then, there is a final reconciliation at an exit area for inventory control, in this example. Preferably, the reconciliation only occurs at the exit area to reduce computation and complexity.
[0028] A third exemplary way the personal item 108 can be associated with the inventory item 106 is by proximity to the RFID reader 104 , check-out system or exit area. For example, when a person carrying his library card and a stack of books enters a revolving door exit, a check-out system can associate the books with the library card, automatically check them out, and signal for the door to open. Alternatively, if, for example, the library card was expired, the check-out system could signal the revolving door to only permit the person to go back into the library and, optionally sound an alarm or alerting device.
[0029] A fourth exemplary way the personal item 108 can be associated with the inventory item 106 is through using a cell phone having the RFID reader 104 on it and specialized software that, optionally, may interact with a check-out system in a facility. For example, a person could avoid a movie line by using his cell phone to read the personal RFID tag 102 on his credit card, select a movie, and send the information to the cashier system, receiving in return an electronic ticket for entrance into the movie on his cell phone that, perhaps, interacts with a turnstile letting him enter the theatre. Of course, there are other ways the personal item 108 can be associated with the inventory item 106 .
[0030] FIG. 2 shows another exemplary method for interaction with inventory. In this exemplary method, there is an inventory 200 with a number of inventory items, {inventory item one 106 , inventory item two 202 , . . . inventory item n 204 }. Initially, each inventory item 106 , 202 , 204 is associated with a default inventory value 205 . With the default inventory value 205 , the inventory system can identify by reading and keep track of inventory items 102 , 202 , 204 that have not yet been associated with RFID tags. Each inventory item 106 , 202 , 204 is later associated with a unique inventory RFID tag so that inventory item one 106 is associated with inventory RFID tag 100 , inventory item two 202 is associated with inventory RFID tag 206 , . . . and inventory item n 204 is associated with inventory RFID tag 208 .
[0031] Initially, the personal item 108 is associated with a default value 210 , in this exemplary method. The default value may be a security code or identifier. The personal item 108 is later associated with one or more personal cards, such as a credit card 212 , an identification card 214 , a smart card 216 , and a debit card 218 . The personal item 108 may be associated with the cards 12 , 214 , 216 , 218 through a cell phone, cashier system, the Internet, or any other association method. Other kinds of cards may also be associated with the credit card in this exemplary method.
[0032] In an exit area 220 , the inventory RFID tags 100 , 206 , 208 are read by the RFID reader 104 and the corresponding inventory items 106 , 202 , 204 are associated to the personal item 108 . This may be done automatically when the items are in proximity to the RFID reader 104 or at some signal from a processor in the exit area, such as a check-out machine. Non-portable inventory items may be represented by tokens having an RFID tag. If any of the inventory items 106 , 202 , 204 is associated with the default inventory value 205 , a notification may be issued for assistance in the exit area 220 .
[0033] Before check-out, the inventory items may be provided for review on a display in the exit area 220 . For example, the check-out may request an acknowledgement, for example, swiping the personal item 108 or an associated card. Some sort of acknowledgement may be requested even to associate inventory items 106 , 202 , 204 to the personal item 108 . The acknowledgement may be an agreement to sale terms, contract terms, license terms, or the like.
[0034] After association, the inventory items 106 , 202 , 204 are checked-out to the personal item 108 . In an Internet application, for example, the inventory item may be shipped to a specified location 224 , after check-out. The person may be permitted to leave the exit area 220 after check-out by, for example, opening a door 222 . If there are any problems encountered during association or check-out, the person may be detained in the exit area 220 , alarms may sound, or notifications may be issued.
[0035] FIG. 3 shows an exemplary computer-readable medium having instructions for performing a method of interaction with inventory. In FIG. 3 , a processor 300 accesses a storage device 302 holding instructions in software 304 for performing a method of interaction with inventory. The storage device 302 may be a memory in the processor 300 , a CD, or any other kind of storage. The processor 300 may be in the exit area 220 or be associated with or a part of the RFID reader 104 , a cell phone, or another kind of machine. The RFID reader 104 could be part of the cell phone. The processor 2300 may be in any kind of facility, such as a library, retail store, or tool crib.
[0036] FIG. 4 shows an exemplary system for interaction with inventory. The system includes one or more inventory items 106 having inventory RFID tags 100 , a check-out system 400 , and at least one exit area 220 . The check-out system 400 includes at least one RFID reader 104 . The RFID reader 104 reads the inventory RFID tag(s) 100 and the personal RFID tag 102 on the personal item 108 , when they are in proximity to the RFID reader 104 . The check-out system 400 associates the inventory item(s) 106 to the personal item 108 .
[0037] The exit area 220 communicates with the check-out system 400 and allows passage, in response to a signal 402 from the check-out system 400 . Passage may be allowed by, for example, opening a door or operating a revolving door. The signal may be an indication of agreement to the association and check-out. The exit area 20 may be adapted to existing equipment in a retail store, a library, a tool crib, or any other kind of facility. The door may be coupled to one or more check-out queue to maximize throughput.
[0038] A returned items area 404 , such as a drop box receives returned items. The returned items area 404 may automatically de-associate the returned inventory item 106 from the personal item 108 by communicating with the check-out system 400 and/or exit area 220 .
[0039] FIGS. 5 and 6 show an exemplary shopping cart 500 for interaction with inventory. The shopping cart 500 includes a holder 502 and a list-making component 504 .
[0040] The holder 502 receives acquired items, {acquired item one 506 . . . acquired item M 508 }, from inventory. Acquired items 506 , 508 may be read with the RFID reader 104 at some point, such as when placed in the holder 502 . In a web application, the holder may be virtual and represented on a web page.
[0041] The list-making component 504 may include the RFID reader 104 . Alternately, the RFID reader 104 may be coupled to a part of the shopping cart 500 , say the holder 502 or the RFID reader 104 may be on a cell phone, with another device. The list-making component 504 creates and maintains an interim list 510 of acquired items 506 , 508 and also provides a final list 512 for reconciliation. The interim list 510 may associate acquired items to the personal item 108 or this may be done later at, say the exit area 220 or upon request by a person, machine, or device. In a web application, the list-making component 504 may be associated with a web page, icon, or the like.
[0042] The exit area 220 receives the final list 512 and requests an indication of agreement. The exit area 220 may have a number of exits in communication with the list-making component 504 to allow passage only after a valid sale. An alarm may be sounded by the list-making component 504 or the exit area 220 upon an invalid sale.
[0043] FIG. 7 shows an exemplary cell phone 700 for interaction with inventory. The cell phone 700 includes a list-making component 504 and an RFID reader 104 . An interim list 510 is created and then the cell phone 700 sends the final list 512 and an indication of agreement to the exit area 220 .
[0044] FIG. 8 shows an exemplary exit area 220 for interaction with inventory. The exit area 220 includes the RFID reader 104 , a check-out component 800 , and a sensor 802 . The RFID reader 104 reads RFID tags 102 , 100 , 208 for the personal card 108 and inventory item(s) 106 , 204 when they are in proximity to the RFID reader 104 .
[0045] The check-out component 800 automatically checks out the inventory items 106 , 204 to the personal item 108 , after they are read by the RFID reader 104 . The check-out component 800 communicates with the RFID reader 104 and receives information associated with the personal item 108 and the inventory item(s) 106 , 204 from the RFID reader 104 .
[0046] The sensor 802 operates one or more exit ways upon receiving a signal from the check-out component 800 and may receive other information from the check-out component 800 . For example, the check-out component may send a signal to the sensor 802 after receiving a confirmation, such as a personal card swipe or entry of a personal identification number (PIN).
[0047] One use case or scenario includes on entry to a facility, reading all RFIDs on a person, on exit, read all RFIDs on the person, associate the two and provide the association for reconciliation by the person. After reconciliation, depending on the application, a sale may take place using a payment method associated with one of the RFIDs on the person. For a library application, media would be checked out to the person's library card. For a tool shed application, tools that had left the inventory would be associated with the person. Of course, there are many applications for this exemplary method embodiment of the present invention.
[0048] In another scenario: on exit only, read all RFIDs on the person and all RFIDs in proximity to the person, associate the two and provide the association for reconciliation by the person. Do not allow exit until the association is confirmed by the person. In another embodiment, exit is allowed, however an alarm or other notice is provided of a potential shoplifting event. In one embodiment, it is determined which items were brought into the facility, which are not part of the inventory at the facility.
[0049] In another scenario, each RFID has a unique identifier. A computing device receiving an RFID reading is able to check what the RFID is associated with and perform the appropriate action. In this exemplary system, there is a database searchable by RFID identifiers. In another exemplary system, an RFID reader selectively reads RFIDs according to their type. For example, in a library application, a library RFID reader only reads the library card RFID on the person and ignores other RFIDs, such as credit cards, protecting the privacy of the person. In the library application, the unique identifier associated with the library card RFID need only be unique to a particular library. In a retail sales application, each credit card RFID for each person needs to be unique.
[0050] In another scenario, the person makes a virtual entry into and virtual exit from a virtual inventory, associating inventory to personal items.
[0051] Another scenario includes a cell phone used as a smartcard or credit card. The cell phone is associated with information, such as GPS tracking information, owner identify information, and the like. For example, the person walks into a library with his cell phone on, browses, picks up four books, walks out of the library, and the exemplary system automatically checks the four books out on the library account associated with the cell phone. In another example, the person walks into a convenience store with his cell phone on, picks up a food item, walks out of the store, and the exemplary system automatically charges the food item to a debit card associated with an RFID tag on the person. In another example, the person walks into a toy store, picks up a token having an RFID tag that is associated with a toy too large to carry, walks to the exit area, and the exemplary system automatically provides a selection of a credit card or debit card associated with the cell phone for purchasing the toy. In one embodiment, the cell phone has text message and review capability so that the person can review the purchase and order anything he forgot.
[0052] The exemplary embodiments of the present invention have many advantages, including minimizing shop-lifting by not allowing exit unless a customer's card were associated with the inventory at the point of exit. Moving the work to where it is mostly naturally likely to take place, either in a static location, such as at an exit, or dynamically in specialized shopping carts or with specialized mobile cell phones, has the advantage of virtually as many check-out queues as there are customers. Another advantage is the automation of check out jobs so that a person need not even check himself out, but is automatically scanned. Another advantage is allowing multiple queues and multiple exits, preventing bottlenecks that typically occur at single exits.
[0053] As described above, the embodiments of the invention may be embodied in the form of computer implemented processes and apparatuses for practicing those processes. Embodiments of the invention may also be embodied in the form of computer program code containing instructions embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other computer-readable storage medium, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the invention. The present invention can also be embodied in the form of computer program code, for example, whether stored in a storage medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the invention. When implemented on a general-purpose microprocessor, the computer program code segments configure the microprocessor to create specific logic circuits.
[0054] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. For example, various personal items other than types of cards may be used for practicing various embodiments of the present invention. In addition, future improvements or changes to standards may be used with minor adaptations of various embodiments of the present invention. Furthermore, various components may be implemented in hardware, software, or firmware or any combination thereof. Finally, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention is not to be limited to the particular embodiment disclosed as the best or only mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. | Customer interaction with inventory via radio frequency identification (RFID) are disclosed, where a unique RFID is combined into ID cards, credit, debit, and smartcards. The current inventory RFID technology and RFID reader are moved into a place convenient to the end-user or customer to remove the need for cashiers. Some applications include point-of-sale terminals, libraries, tool cribs, and places where customers or end-users remove items from inventories and inventories need to be monitored. | 6 |
[0001] The present application claims priority from U.S. Provisional Patent Application Ser. No. 61/129,221 filed on Jun. 12, 2008.
FIELD OF THE INVENTION
[0002] The present invention relates to the general field of orthopaedic surgery components and methods and is particularly concerned with an orthopaedic fixation component and method.
BACKGROUND
[0003] There exists a wide variety of situations wherein it is desirable to fixate adjacent bone pieces or segments to promote healing of a fracture. Such situations occur, for example, whenever a fragment of the greater trochanteric portion of the femur bone needs to be fixated to the shaft of the femur.
[0004] With the aging demographics of many industrialized countries, hip related surgical procedures are becoming increasingly prevalent. An example of such procedures is the so-called total hip replacement surgery or arthroplasty which is typically performed as a consequence of osteoarthritis of the hip joint. The procedure involves replacing the diseased cartilage and bone of the hip joint with artificial materials including an artificial prosthesis.
[0005] During the procedure, a segment of the greater trochanteric portion of the femoral bone is typically temporarily osteotomized, that is a the greater trochanter is surgically separated from the proximal end of the femur so that the soft tissue attached to the greater trochanter can be moved aside in preparation for implantation of the femoral stem of the replacement prosthesis into the medullar canal of the femoral shaft. Once the femoral stem of the prosthesis is seated within the medullar canal in the femur, the greater trochanter is re-attached to the proximal end of the femur.
[0006] The greater trochanter is subjected to considerable stress imparted thereon by anatomical structures such as muscles attachments during normal use of the hip. Accordingly, mechanical fixation of the greater trochanter to the femoral shaft is mandatory in order to promote healing of the fracture created by the osteotomizing step of the hip replacement procedure or traumatic injury.
[0007] Also, because of the considerable stress imparted on the greater trochanter as a consequence of the total hip arthroplasty procedure, it is estimated that this type of procedure is associated with a relatively high percentage of greater trochanter post-surgical fractures, which, in turn, may require fixation.
[0008] Other examples of situations wherein fixation of the greater trochanter to the femur shaft is required include trochanter and/or proximal femur reconstruction, corrective or revision hip surgery and the like.
[0009] One relatively common prior art method for fixating the greater trochanter to the proximal femur shaft is a so-called “cerclage” fixation technique wherein a flexible member, such as a cable, is drawn tight and clamped in order to encircle the target fixation site and to hold the bone portions together until they have time to heal.
[0010] Typically, the surgical cables are implanted using tensioning devices which apply tension to a surgical cable looped around the bone. Crimps are then added and deformed to clamp the cable loop in place.
[0011] The so-called “cerclage” methods, although somewhat useful, are associated with a number of drawbacks. For example, such procedures are typically considered relatively complex. Furthermore, cable failure, migration or loosening may lead to fixation loss and non-union of the bone fragments with clinical consequences such as pain, lack of functionality and the like.
[0012] Other types of components have been devised in attempts to provide solutions for fixating the greater trochanter to the femur shaft. For example, some components include a bone grip for engaging over the trochanter and a plate portion for extending down over the shaft of the femur.
[0013] A well known typical example of such type of component is the so-called “Cable-Ready” (a registered trade mark) greater trochanteric re-attachment system developed by Zimmer. This system involves the use of a component which has a substantially straight, flat and elongated plate portion, integral with a hooked portion terminating in a spike. Ideally, the hooked grip portion lies over the greater trochanter, and the plate portion overlies the shaft of the femur. Both portions have apertures to receive “cerclage” cables, which are passed around the bone, to secure the device in place.
[0014] Again, although somewhat useful, such devices also suffer from numerous drawbacks. Indeed, as is well known, the greater trochanter lies laterally, close to the skin, and can be easily palpated on the lateral side of the thigh. Because it is the most lateral point of the hip region, the greater trochanter may cause discomforts when lateral pressure is exerted on the side of the body such as when an individual lies on his or her side on a hard surface. Most prior art fixation plates increase the discomfort by being located over the most prominent portion of the greater trochanter. Also, some prior art devices require that relatively large incisions be performed in large leg muscles to position them properly over the greater trochanter, with all the discomfort and risk for complications associated with such operations.
[0015] Accordingly, there exists a need for an improved orthopaedic fixation component and it is a general object of the present invention to provide such an improved orthopaedic fixation component.
SUMMARY OF THE INVENTION
[0016] In a broad aspect, the invention provides an orthopaedic fixation component attachable to a femur, said femur defining a femur shaft, a femur head and a femur neck extending therebetween, said femur further defining a greater trochanter limiting laterally said femur neck, said orthopaedic fixation component comprising: a shaft section fixation portion and an end section fixation portion extending substantially longitudinally therefrom, said shaft section and end section fixation portions being respectively securable to said femur shaft and said greater trochanter; said end section fixation portion including a pair of end arms, said end arms being configured, sized and positioned to delimit a trochanter receiving recess for substantially fittingly receiving a prominent portion of said greater trochanter.
[0017] The proposed orthopaedic fixation component is intended to be used in particular with generally elongated bones such as the femur and in particular for greater trochanteric re-attachment although other applications are within the scope of the present invention.
[0018] The proposed orthopaedic fixation component provides a variety of advantages for both the surgeon and the intended patient, some of which are disclosed in greater details at the end of the detailed description portion of the present application. In short, the proposed orthopaedic fixation component is designed so as to improve fixation while reducing post-operative complications.
[0019] The present invention also relates to a method of using an orthopaedic fixation component in order to also improve fixation while reducing post-operative complications.
[0020] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] An embodiment of the present invention will now be disclosed, by way of example, in reference to the following drawings, in which:
[0022] FIG. 1 , in a perspective view, illustrates an orthopaedic fixation component in accordance with an embodiment of the present invention operatively mounted on a femoral bone, only a proximal portion of which is shown;
[0023] FIG. 2 , in a front view, illustrates the orthopaedic fixation component and femoral bone shown in FIG. 1 ;
[0024] FIG. 3 , in a perspective view similar to that of FIG. 1 , illustrates the insertion within the bone of some of the attachment screws used with the orthopaedic fixation component in accordance with the present invention;
[0025] FIG. 4 a , in a transversal cross-sectional view taking along arrows A-A of FIG. 3 , illustrates the spatial relationship between the inserted attachment screws shown in FIG. 3 ;
[0026] FIG. 4 b , in a transversal cross-sectional view taking along arrows B-B of FIG. 3 , illustrates the spatial relationship between shaft attachment screws shown in FIG. 3 and the stem of a replacement prosthesis;
[0027] FIG. 5 , in a top view, illustrates some of the features of the proximal portion of the orthopaedic fixation component in FIGS. 1 through 4 when the latter is anchored to the femoral bone shown in FIGS. 1 through 3 ;
[0028] FIG. 6 , in a front view, illustrates the orthopaedic fixation component shown in FIGS. 1 through 5 ;
[0029] FIG. 7 , in a transversal cross-sectional view, illustrates the cross-sectional configuration of an end arm, part of the orthopaedic fixation component, the cross-section being taken across line C-C of FIG. 6 ; and
[0030] FIG. 8 , in a transversal cross-sectional view, illustrates the cross-sectional configuration of an end arm, the cross-section being taken along lines D-D of FIG. 6 .
DETAILED DESCRIPTION
[0031] Referring to FIG. 1 , there is shown, in a perspective view, a fixation component in accordance with an embodiment of the present invention, generally indicated by the reference numeral 10 . The fixation component 10 is shown, by way of example, mounted to a femur generally indicated by reference numeral 12 . It should, however, be understood that the fixation component 10 is only shown mounted to a femur 12 by way of example and that the fixation component 10 could be used for fixating or securing bone segments located at other anatomical regions without departing from the present invention.
[0032] More specifically, the fixation component 10 is particularly well adapted to be used at anatomical regions involving substantially elongated bones defining a corresponding bone end region. By way of non limitative examples, the fixation component 10 could, for example, be used in applications involving the distal femur, the proximal tibia as well as the proximal and distal humerus regions.
[0033] As is well known, the femur 12 is an elongated bone. As shown in FIGS. 1 through 3 , the femur 12 includes a body or shaft 14 defining a pair of longitudinally opposed extremities or ends (only the proximal one of which is shown in the Figures). The body or shaft 14 of the femur is slightly bowed inferiorly and is narrowest at its mid-point. Its middle two quarters are approximately circular in transverse section. The distal end (not shown) of the femur shaft 14 is broadened by medial and lateral condyles where it articulates with the tibia and patella to form the knee joint.
[0034] The proximal end, shown in FIG. 1 , includes a femur head 16 , a femur neck 18 , a greater trochanter 20 and a lesser trochanter 22 . As is also well known, the femur head 16 is typically smooth and forms 2/3 of a sphere. It is directed medially, superiorly, and slightly inferiorly to fit into the acetabulum of the hip bone (not shown).
[0035] The femur neck 18 connects the femur head 16 to the femur body or shaft 14 , typically at an angle of approximately 125 degrees. The femur neck 18 is limited laterally by the greater trochanter 20 and is narrowest in diameter at its mid-section. A broad, rough inter-trochanteric line runs infero-medially from the greater trochanter. This inter-trochanteric line passes inferior to the lesser trochanter and becomes continuous with the spiral line on the posterior aspect of the femur.
[0036] The inter-trochanteric line is produced by the attachment of the massive illio-femoral ligament (not shown). The inter-trochanteric line separates the interior surface of the femur neck 18 from the femur body or shaft 14 of the femur 12 . A prominent ridge, the inter-trochanteric crest, unites the two trochanters 20 , 22 posteriorly.
[0037] In the anatomical position, a line joining the tips of the greater trochanters 20 normally passes through the center of the femur heads 16 (only on of which is shown) and the pubic tubercles (not shown). As shown more specifically in FIG. 2 , the greater trochanter 20 of the femur 12 is a substantially large, somewhat rectangular projection from the junction of the femur neck 18 and the femur body 14 . It provides an attachment for several muscles of the gluteal region. Some of these muscular attachments are illustrated schematically in FIG. 1 .
[0038] As is well known, both the gluteus medius and the gluteus minimus are used for abduction and medial rotation of the thigh as well as to steady the pelvis. The distal attachment of the gluteus medius is typically located on the lateral surface of the greater trochanter 20 while the distal attachment of the gluteus minimus is typically located on the anterior surface of the greater trochanter 20 .
[0039] The obturator internus and the gemelli, superior and inferior, are used for laterally rotating the extended thigh and abducting the flexed thigh. They are also used to steady the femur head 16 in the acetabulum (not shown). Both the obturator internus and the gemini superior and inferior have their distal attachment on the medial surface of the greater trochanter 20 .
[0040] Another muscle having its distal attachment on the greater trochanter 20 is the piriformis muscle attached to the superior border of the greater trochanter 20 . It should be understood that the muscular insertions illustrated in FIG. 1 are rough schematic representations of the three major muscle groups hereinafter discussed and should only be considered an approximation of the actual anatomical reality.
[0041] Referring now more specifically to FIG. 6 , there is shown in greater details some of the features of the fixation component 10 . In general terms, the fixation component 10 includes a shaft section fixation portion 24 and a substantially longitudinally and integrally extending end section fixation portion 26 for being respectively secured to a corresponding shaft section and a corresponding end section of bone such as the femur shaft 14 and the greater trochanter 20 shown in FIG. 1 through 3 .
[0042] In the preferred embodiment, the fixation component 10 has a generally asymmetrical “Y”-shaped configuration defining a shaft arm generally indicated by the reference numeral 28 attached to a pair of end arms generally indicated by the reference numerals 30 and 32 .
[0043] The end arms 30 , 32 typically extend integrally from the shaft arm 28 although they may be permanently or reversibly attached to the latter without departing from the scope of the present invention. Also, in the embodiment shown throughout the Figures, the shaft arm 28 and the end arms 30 , 32 are rigidly secured to each other in a substantially stable spatial relationship relative to each other.
[0044] However, in other embodiments of the invention (not shown) the shaft arm 28 and the end arms 30 , 32 could be pivotally, slidably or otherwise movably connected to each other so as to allow for selective spatial movement therebetween in predetermined combinations. For example, both end arms 30 , 32 could be fixedly secured to each other while being movably secured to the shaft arm 28 . Alternatively, the end arms 30 , 32 could be movable relative to each other.
[0045] In instances wherein the shaft arm 28 and/or the end arms 30 , 32 are movable relative to each other, the fixation component 10 may further be provided with arm movement preventing means for either permanently or releasably selectively preventing the relative movements between the shaft arm 28 and one or both of the end arms 30 , 32 .
[0046] The end arms 30 , 32 are typically configured, sized and positioned so as to diverge away from each other, together forming a substantially asymmetrical V-shaped configuration. Each one of the end arms 30 , 32 has a substantially elongated configuration defining a corresponding end arm proximal section 34 and a longitudinally opposed end arm distal section 36 . Typically, the end arm distal sections 36 of each end arm 30 , 32 merge integrally with each other.
[0047] Each one of the end arms 30 , 32 also defines a corresponding end arm outer edge 38 and a substantially transversely opposed end arm inner edge 40 . The end arm inner edges 40 together define a trochanter receiving recess 42 extending therebetween for receiving at least a selected portion of the greater trochanter 20 . The selected portion of the greater trochanter 20 adapted to be received within the trochanter receiving recess 42 is typically a particularly prominent or protruding portion 44 (seen in FIG. 1 ) of the greater trochanter 20 .
[0048] One of the main features of the present invention resides in that the end arms 30 , 32 are configured, sized and positioned such that the trochanter receiving recess 42 substantially fittingly receives the prominent portion 44 of the greater trochanter 20 . More specifically, the end arms 30 , 32 are configured, sized and positioned such that the opposed end arms inner edges 40 substantially partially encircle the prominent portion 44 of the greater trochanter 20 .
[0049] The end arm inner edges 40 typically merge with each other about their respective end arm distal sections 36 so as to form a nadir 46 . The end arms 30 , 32 are typically further configured, sized and positioned such that the nadir 46 is located substantially underneath the prominent portion 44 of the trochanter 20 when the fixation component 10 is operatively mounted on the femur 12 .
[0050] Another feature of the present invention resides in that the end arms 30 , 32 are configured, sized and positioned relative to each other so as to optimize the retaining action exerted thereby on the greater trochanter 20 so as to prevent relative movement between trochanteric portions and lessen the probability of creating a secondary fracture.
[0051] The end arms 30 , 32 provide a multi-directional holding action adapted to cancel out the tendency of the three major muscles of which the distal insertion is shown in FIG. 1 tending to exert a pulling action upon the greater trochanter 20 along multiple vectorial directions. This holding action prevents the trochanteric portions from being pulled in any one of the vectorial directions and, in particular, any one of the three major directions illustrated in FIG. 1 . The specific configuration, size and position of the end arms 30 , 32 is also adapted to take into account that there is an intense and strong pull, particularly of the abductor muscles of the hip during normal activities of daily living such as ambulation.
[0052] The end arms 30 , 32 are each provided with an end arm attachment means for attaching or anchoring the end arms 30 , 32 to the greater trochanter 20 . In the preferred embodiment, the end arm attachment means includes at least one and preferably two end arm fastening apertures 48 extending through corresponding end arms 30 or 32 .
[0053] Each end arm fastening aperture 48 is adapted to receive a corresponding fastening component such as an end arm bone screw 50 (seen for example in FIG. 1 ). Typically, each end arm fastening aperture 48 has a substantially countersunk portion. Typically, although by no means exclusively, the end arm bone screws 50 are of the self-locking type. Self-locking type screws are typically preferred, at least in part, because of the relatively thin layer of the cortex of the bone in the regions of the greater trochanter 20 .
[0054] As illustrated more specifically in FIG. 3 through 5 , the configuration, size and position of the end arms 30 , 32 and their corresponding end arm fastening apertures 48 is such that the end arm bone screws 50 provide an entrapment effect for further preventing trochanteric portions from being fractured or pulled out by various forces acting thereon.
[0055] The configuration, size and position of the end arms 30 , 32 is also chosen in order to take into consideration the position of the insertion of the main muscle attachments on the greater trochanter 20 .
[0056] Referring back to the schematically illustrated muscular insertions of FIG. 1 , it can be seen, the end arms 30 , 32 are configured, sized and positioned so that their respective inner and outer peripheral edges 40 , 38 substantially clear these muscular attachments or, at least, minimally interfere therewith so as to reduce the risks of clinical problems once the fixation component 10 is operationally attached to the femur 12 and also so as to facilitate the anchoring of the fixation component 10 to the femur 12 during surgery.
[0057] As shown more specifically in FIG. 6 , the end arms 30 , 32 , typically diverge away from each other in a proximal direction so as to define an end arm angle “A” therebetween, Typically, although by no means exclusively, the end arm angle “A” has a value of between 60 and 120 degrees.
[0058] Another feature of the present invention resides in the cross-sectional configuration of at least one and preferably both end arms 30 , 32 . As illustrated more specifically in FIGS. 7 and 8 , each end arm 30 , 32 preferably has a substantially concave end arm inner surface 51 and a substantially convex end arm outer surface 52 . Also, each of the end arms 30 , 32 is also provided with substantially rounded end arm inner and outer edges 40 , 38 .
[0059] The substantially concave end arm inner surface 51 is typically variable along the length of the end arms 30 , 32 and adapted to allow for an improved contact engagement between the end arm inner surfaces 51 and the substantially convex outer surface of the greater trochanter 20 .
[0060] The substantially arc-shaped cross-sectional profile of the end arms 30 , 32 is also adapted to increase the structural strength thereof and, hence, allow for minimization of the overall thickness of the end arms 30 , 32 for a given material and considering given auxiliary geometrical variables. The optimized fit between the contact surfaces of the end arm inner surface 51 and the outer surface of the greater trochanter 20 combined with the relatively small cross-sectional distance between the end arm inner and outer surfaces 51 , 52 is adapted to provide greater comfort to the patient with reduced risks of clinical complications.
[0061] As illustrated more specifically in FIGS. 1 through 5 , the end arm proximal portion 34 of at least one and typically both end arms 30 , 32 typically curves inwardly so as to substantially override at least a portion of the greater trochanter 20 and in operational position provide a retaining means against axial displacement of portions thereof.
[0062] Also, at least one and preferably both of the end arms 30 , 32 typically taper proximally so as to define a corresponding substantially pointed anchoring apex 53 . Typically, the pointed apex 53 is adapted to be inserted into the cortical portion of the upper portion of the greater trochanter 20 . Typically, although by no means exclusively, the distance D between the apex 53 and the nadir 46 has a value of between 40 and 70 millimetres.
[0063] Alternatively, in an embodiment of the invention not shown, the end arm proximal portion 34 of at least one of the end arms 30 , 32 could be deprived of a pointed apex 53 and/or made out of a substantially deformable material so as to allow the surgeon to bend the latter to a suitable shape for increasing the retention characteristics thereof.
[0064] Referring back to FIGS. 1 through 3 and 6 , there is shown that the shaft arm 28 typically has a substantially elongated configuration defining a shaft arm longitudinal axis 55 (shown in FIG. 6 ). Another feature of the present invention resides in that the substantially V-shaped configuration formed by the end arms 30 , 32 is preferably substantially or laterally offset relative to the shaft arm longitudinal axis 55 .
[0065] Since the main muscular attachments to the greater trochanter 20 are located substantially anteriorly, the end arms 30 , 32 are typically offset substantially posteriorly relative to the shaft arm longitudinal axis 55 so as to reduce the risk of interference or obstruction with the muscles attached to the greater trochanter 20 . Typically, as illustrated throughout the Figures, the end arm 32 being operatively mounted more anteriorly than the end arm 30 , the end arm 32 is positioned so as to extend at lesser angle relative to the shaft longitudinal axis 55 than the end arm 30 .
[0066] The shaft arm 28 is provided with a suitable shaft arm attachment means for attaching the shaft arm 28 to the femur shaft 14 . In the embodiment shown throughout the Figures, the shaft arm attachment means includes shaft arm attachment apertures 54 for receiving suitable attachment components such as shaft arm screws 56 (seen for example in FIG. 1 ). The shaft arm attachment apertures 54 are typically provided with a countersunk section.
[0067] Each shaft arms attachment aperture 54 typically extends through a corresponding shaft arm flange or tab 58 extending integrally and substantially laterally from the shaft arm 28 , The shaft arm flanges or tabs 58 and their corresponding shaft arm attachment apertures 54 are positioned in an offset relationship relative to each other so as to prevent the shaft arm screws 56 from interfering with each other when the fixation component 10 is operatively mounted.
[0068] Typically, the shaft arm tabs 58 and corresponding shaft arm attachment apertures 54 are grouped in pairs with members of a given pair extending in laterally opposite and longitudinally offset relationships relative to each other.
[0069] As illustrated more specifically in FIG. 4 b , the shaft arm attachment apertures 54 are positioned so as to no only provide sufficient clearance between the shaft arm screws 56 but also to so as to reduce the risks of interference with the femoral stem 60 of a hip replacement prosthesis when the fixation component 10 is used on a femur 12 having such a prosthesis.
[0070] The shaft arm attachment means typically further includes “cerclage” cable channels 66 extending substantially transversely across the shaft arm 28 for receiving “cerclage” cables 68 . Typically, although by no means exclusively, a pair of cerclage cable channels 66 extends through the shaft arm 28 proximally to each pair of shaft arm attachment apertures 54 .
[0071] The fixation component 10 could be provided with “cerclage” cables 68 already having a portion thereof secured to the shaft arm 28 or be simply adapted to receive conventional “cerclage” cables such as the Zimmer Co—Cr cables.
[0072] Alternatively, the fixation component 10 could be provided with or used in conjunction with a “cerclage” cable 68 made out of a super-elastic material. Preferably, although by no means exclusively, the super-elastic “cerclage” cable could be of the type having a braided tuberous structure. Such a cable is described in the PCT application bearing Serial No. PCT/CA2005/001859, naming Brailovski et al as inventors, the entire content of which is expressly incorporated herein by reference thereto.
[0073] Super-elastic cables having a braided tuberous structure provide a synergistic advantage when used with the hereinabove disclosed fixation component 10 by reducing the contact pressure on connected bones and maintaining compression between fragments during the fracture healing period.
[0074] In use, the specific configuration and size of the various sections of the fixation component 10 allows a surgeon to position the fixation component 10 on the femur 12 of an intended patient in such a manner that the end arms 30 , 32 are strategically positioned to reduce the risk of having portions or fragments of the greater trochanter 20 being displaced or pulled out of alignment relative to their optimal anatomical relationship with the femur shaft 14 .
[0075] The configuration, size and relative position of the end arms 30 , 32 relative to the shaft arm 28 take into consideration both the orientation and magnitude of the forces exerted by the muscles attached to the greater trochanter 20 and the insertion location of such muscles in order to reduce the risk of interference therewith.
[0076] The retaining action exerted by the end arms 30 , 32 on portions or fragments of the greater trochanter 20 is compounded by the strategic location of end arm fastening apertures 48 adapted to receive self-locking bone screws oriented to provide an entrapment effect.
[0077] Furthermore, the configuration of the fixation component 10 is designed in such a manner that the outward radial protrusion of the end arms 30 , 32 away from the greater trochanter 20 is also minimized. Indeed, as mentioned previously, the end arms 30 , 32 are configured, sized and positioned relative to the shaft arm 28 in such a manner that they create a trochanter receiving recess therebetween, the trochanter receiving recess 42 being, in turn, configured and sized for substantially fittingly circumventing the prominent portion 44 of the greater trochanter 20 .
[0078] Also, as mentioned previously, the configuration of the end arms 30 , 32 , including their cross-sectional configuration, is such that the fit with the surface of the greater trochanter 20 is optimized and the structural characteristics of the end arms 30 , 32 is improved, allowing for a thinner structure. The avoidance of the prominent portion 44 of the greater trochanter 20 synergistically combined with the improved contact with the greater trochanter 20 and the relatively thin profile reduces the protrusion of the end arms 30 , 32 from the femur 12 translates not only into an improved aesthetical appearance but also a greater comfort for the patient.
[0079] The shaft arm attachment means provided with the fixation component 10 allows the latter to be used with a wide variety of patients including patients requiring total hip arthroplasty prosthesis. Indeed, the strategic positioning of the shaft arm attachment apertures 54 allows for a suitable number of shaft arm screws 56 to be used in order to solidly anchor the shaft arm 28 to the femur shaft 14 while reducing the risk of interference of the shaft arm screws 56 not only with adjacent shaft arm screws 56 but also with the femoral stem 60 of a hip replacement prosthesis inserted within the medullary canal of the femur 12 such as shown in FIG. 4 b.
[0080] Furthermore, the “cerclage” cable channels 66 allow for the use of either conventional “cerclage” cables 68 or so-called super-elastic cables 68 . The use of super-elastic cables 68 and, in particular, super-elastic cables 68 having a braided tubular structure provides a synergistic effect when combined with the other features of the fixation component 10 .
[0081] By reducing the contact pressure on contacted bones, these cables 68 allow for the fixation component 10 to be used with patients having particularly fragile bone structures. Also, such cables 68 are adapted to maintain a compression force between fragments during the fracture healing period which is particularly crucial with such patients.
[0082] Furthermore, the positioning of the “cerclage” cable channels 66 in an alternating fashion with pairs of shaft arm attachment apertures 54 provides an optimal distribution of force exerted on the bone structure for obtaining secure anchorage while reducing the risk of traumatizing the femur shaft 14 .
[0083] The present invention also relates to a method of using an orthopaedic fixation component such as the hereinabove disclosed fixation component 10 or other suitable fixation components. The orthopaedic method, in accordance with the present invention, includes positioning a fixation component to a bone structure defining a bone shaft and a bone end section having a prominent region in such a manner that the fixation component substantially avoids the prominent section while providing an efficient retaining action for preventing relative displacement between the bone structures.
[0084] The proposed orthopaedic method also includes as an independent or combined step the use of a “cerclage” cable made out of a super-elastic material for attaching the fixation component to the bone. Preferably, the step of using a “cerclage” cable includes using a super-elastic “cerclage” cable having a braided structure for attaching the fixation component to the bone structure.
[0085] Although the present invention has been described hereinabove by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims. | An orthopaedic fixation component attachable to a femur, said femur defining a femur shaft, a femur head and a femur neck extending therebetween, said femur further defining a greater trochanter limiting laterally said femur neck, said orthopaedic fixation component comprising: a shaft section fixation portion and an end section fixation portion extending substantially longitudinally therefrom, said shaft section and end section fixation portions being respectively securable to said femur shaft and said greater trochanter; said end section fixation portion including a pair of end arms, said end arms being configured, sized and positioned to delimit a trochanter receiving recess for receiving a prominent portion of said greater trochanter. | 0 |
RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Provisional Patent Application Ser. No. 61/106,569 filed on Oct. 18, 2008, which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates in general to a method and apparatus for installing and supporting an electrical submersible pump cable, and in particular to an electrical submersible pump cable having spring loaded anchors for engaging an inside wall of coiled tubing after application of heat.
BACKGROUND OF THE INVENTION
[0003] Electrical submersible pumps (ESP) are normally installed on jointed production tubing and powered by an ESP cable attached to the outside of production tubing. All produced fluids are pumped up the production tubing to the surface.
[0004] Oil well completions are being developed to deploy ESPs on the bottom of continuous coiled tubing where the power cable is placed inside the coiled tubing. In these installations, produced fluids are pumped up the annulus between the coiled tubing and the production tubing, or well casing or liner. Many advantages are gained through the use of coiled tubing such as faster deployment, the elimination of a need for large workover rigs, and less frictional pumping losses.
[0005] Because an ESP cable cannot support its total vertical weight, cable support must be provided by the coiled tubing at regular intervals. Various proposals have been made to provide support, such as the use of dimpling and welding of the coil tubing after pulling the ESP cable through the tubing; however, improvements would be desirable.
SUMMARY OF THE INVENTION
[0006] Disclosed herein is an apparatus that allows for the transfer of the weight of a power cable to borehole tubing, such as coiled tubing, using compressible anchor assemblies and support pins. In one embodiment, the apparatus for supporting the weight of the power cable within the tubing in a borehole has a length of tubing, a length of power cable, a body member, a frangible support element and an anchor assembly. The body member is coupled to a portion of the outer periphery of the cable, with the body member having a first outer diameter and a second outer diameter, wherein the second outer diameter creates a flange for the anchor assembly. In one embodiment, the body member has an inner radius, the inner radius having helical grooves that match the power cable's pitch. When the body member is coupled to the power cable, a threaded connection is formed. Once the body member is coupled to the power cable, the anchor assembly is compressed to fit around the outer periphery of the body member, In an embodiment in which the frangible support element is a support pin, the support pin can be inserted through the anchor assembly's leaf springs such that the anchor assembly is fixed in a compressed state and coupled to the body member. In one embodiment of the present invention, there is a plurality of body members located along the length of the power cable, as well as a plurality of anchor assemblies located on each of the respective body members.
[0007] Once all of the anchor assemblies are in place and compressed, the cable may be transferred into the borehole tubing. The frangible support elements are subjected to a treatment method such that the support elements fail, causing the anchor assemblies to decompress and contact the inner wall of the borehole tubing. This contact point between the anchor assemblies and the inner wall of the borehole tubing acts to transfer the weight of the power cable to the borehole tubing.
[0008] In one embodiment of the present invention, the frangible support element is designed to fail at a predetermined temperature, such that support element can be heated to induce failure. In other embodiments of the present invention, the support element can be designed to fail at increased pressures, electrical charges, resonate frequency, or upon exposure to a solvent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a partial longitudinal cross sectional view illustrating an electrical cable and coiled tubing assembly constructed in accordance with an embodiment of the present invention.
[0010] FIG. 2 is the same partial sectional view as FIG. 1 following a treatment method.
[0011] FIG. 3 is a cross sectional view along line 3 - 3 of FIG. 1 .
[0012] FIG. 4 is a side view of the anchor assembly and support pin in accordance with an embodiment of the present invention.
[0013] FIG. 5 is a cross sectional view of the body member and anchor assembly and a side view of the electrical cable in accordance with an embodiment of the present invention.
[0014] FIG. 6 is a side view along line 6 - 6 of FIG. 5 .
[0015] FIG. 7 is an alternate embodiment of the apparatus shown in FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. For the convenience in referring to the accompanying figures, directional terms are used for reference and illustration only. For example, the directional terms such as “upper”, “lower”, “above”, “below”, and the like are being used to illustrate a relational location.
[0017] 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. In the drawings and specification, there have been disclosed illustrative embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
[0018] With reference now to FIG. 1 , the electrical power line for a submersible pump includes a string of continuous coiled tubing [ 10 ]. Coiled tubing [ 10 ] is steel, has an outer diameter [ 11 ] and an inner wall [ 13 ] and is of conventional materials and dimensions. Coiled tubing [ 10 ] is capable of being wound on a large reel for transport to a well site, and then forced into a well. Power cable [ 20 ] is shown inserted through the length of coiled tubing [ 10 ]. Power cable [ 20 ] is a type particularly for supplying AC power from the surface to a downhole motor for driving a centrifugal pump (not shown), which is located at the lower end of coiled tubing [ 10 ].
[0019] As shown in FIG. 3 , power cable [ 20 ] has three insulated conductors [ 22 ], each surrounded by an insulation layer [ 24 ]. An elastomeric jacket [ 26 ] is extruded over the three insulated conductors [ 22 ]. Elastomeric jacket [ 26 ] has a cylindrical outer diameter which is helically wrapped with a metal strip of armor [ 28 ], which forms helically spaced grooves [ 30 ] ( FIG. 1 ). In one embodiment, elastomeric jacket [ 26 ] is of a material, such as Nitrile rubber, which resists swelling when exposed to hydrocarbon liquid. In this embodiment, tightly wrapped armor [ 28 ] deforms elastomeric jacket [ 26 ] and provides adequate frictional engagement between elastomeric jacket [ 26 ] and minor [ 28 ], preventing slippage due to the weight of power cable [ 20 ].
[0020] Referring back to FIG. 1 , a plurality of body members [ 40 ] are mounted to power cable [ 20 ] at selected intervals. Each body member [ 40 ] has an anchor assembly [ 50 ] coupled on the body member's outer periphery.
[0021] In FIG. 2 , anchor assembly [ 50 ] has been released such that it is no longer in its compressed state. In one embodiment, anchor assembly [ 50 ] releases upon the application of heat to the coiled tubing. In other embodiments of the present invention, the release of anchor assembly [ 50 ] can be triggered by increased pressure, electrical charges, resonate frequency, or solvents. As shown in FIG. 2 , anchor assembly [ 50 ] contacts inner wall [ 13 ] of coiled tubing [ 10 ], thereby transferring the weight of power cable [ 20 ] to coiled tubing [ 10 ].
[0022] FIG. 3 represents a cross sectional view along line 3 - 3 of FIG. 1 . In one embodiment, anchor assembly [ 50 ] is made up of a first engaging member [ 52 ] and a second engaging member [ 54 ]. In another embodiment, anchor assembly [ 50 ] can be made up of only one engaging member that wraps around the entire circumference of the body member [ 40 ], and therefore only uses one frangible support element [ 60 ]. In one embodiment, each engaging member [ 52 , 54 ] can comprise a strip of resilient metal, such as steel. Each engaging member [ 52 , 54 ] has a set of lips at the engaging member's [ 52 , 54 ] edge, which form piano hinge [ 56 ] when interlocked together. In one embodiment, frangible support element [ 60 ] ( FIG. 4 ) can be a support pin and can be inserted into piano hinge [ 56 ], and thereby lock first engaging member [ 52 ] and second engaging member [ 54 ] together in a compressed, substantially cylindrical form. The deflection of each engaging member [ 52 , 54 ] from relatively flat to semi-cylindrical is below the yield point of the metal, such that engaging members [ 52 , 54 ] are elastic. In this compressed form, anchor assembly [ 50 ] is coupled to the body member by contacting the outer periphery of the first outer diameter [ 62 ] of the body member. Referring to FIG. 5 , second outer diameter [ 64 ] of the body member [ 40 ] has a diameter larger than that of first outer diameter [ 62 ] such that it forms a lower flange [ 65 ] and an upper flange [ 67 ]. Lower flange [ 65 ] keeps anchor assembly [ 50 ] from sliding downward when anchor assembly [ 50 ] is in a compressed state. Upper flange [ 67 ] supplies a downward force on anchor assembly [ 50 ], thereby preventing power cable [ 20 ] from slipping downward relative to anchor assembly [ 50 ] when anchor assembly [ 50 ] is in its decompressed state. Dashed lines [ 70 , 72 ] in FIG. 3 represent first engaging member [ 52 ] and second engaging member [ 54 ], respectively, following shearing of frangible support element [ 60 ] ( FIG. 4 ). As shown in FIG. 3 , once anchor assembly [ 50 ] is no longer compressed, first and second engaging members [ 52 , 54 ] spring out to contact the inner wall [ 13 ] of the coiled tubing [ 10 ], while also contacting first outer diameter [ 62 ] of body member [ 40 ].
[0023] FIG. 4 represents a side view of one embodiment of anchor assembly [ 50 ]. In the embodiment shown, anchor assembly [ 50 ] has first engaging member [ 52 ] and second engaging member [ 54 ]. When the two engaging members are compressed together, their respective lips interlock to form piano hinge [ 56 ]. Frangible support element [ 60 ] can then be inserted into piano hinge [ 56 ] in order to lock anchor assembly [ 50 ] into its compressed form. In one embodiment, each engaging member [ 52 , 54 ] contains a plurality of outward-protruding tabs [ 55 ] formed by perforations. Tabs [ 55 ] are operable to contact inner wall [ 13 ] of coiled tubing [ 10 ] when anchor assembly [ 50 ] is in its decompressed position. In one embodiment of the present invention, outward-protruding tabs [ 55 ] are shaped like the gratings of a cheese grater.
[0024] FIG. 5 represents a cross-sectional view of one embodiment of the present invention in which anchor assembly [ 50 ] is coupled to the outer periphery of body member [ 40 ]. In one embodiment, body member [ 40 ] has two symmetrical, semi-cylindrical body halves [ 74 , 76 ]. Each body half has a first outer diameter [ 62 ], lower flange [ 65 ], upper flange [ 67 ] (collectively “flanges”), and an inner diameter [ 66 ]. In an embodiment, flanges [ 65 , 67 ] are larger in diameter than first outer diameter [ 62 ]. Furthermore, in an embodiment of the present invention, flanges [ 65 , 67 ] are larger in diameter than the diameter of the sprung anchor assembly's load shoulder. The load shoulder is the upper edge portion of engaging members [ 52 , 54 ] which abut upper flange [ 67 ]. This allows anchor assembly [ 50 ] to provide an upward force to the upper flange [ 67 ], which in turn allows for transference of power cable's [ 20 ] weight to coiled tubing [ 10 ]. Additionally, FIG. 5 demonstrates how the pitch of inner diameter [ 66 ] matches helically spaced grooves [ 30 ] of power cable [ 20 ]. This matching of the pitch forms a threaded connection, which prevents power cable [ 20 ] from sliding down body member [ 40 ] when placed within the wellbore. FIG. 5 also demonstrates one embodiment in which body halves [ 74 , 76 ] do not meet, and thus only partially surround power cable [ 20 ]. This allows frangible support element [ 60 ] to be more easily inserted into piano hinge [ 56 ].
[0025] FIG. 6 represents a side view along line 6 - 6 of FIG. 5 . As shown, each body half [ 74 , 76 ] partially surrounds the outer periphery of the power cable [ 20 ], and each body half [ 74 , 76 ] also has a second outer diameter [ 64 ] that is larger than the first outer diameter [ 62 ] thereby forming lower flange [ 65 ] and upper flange [ 67 ].
[0026] FIG. 7 represents an optional embodiment in which combined body halves [ 74 , 76 ] completely surround power cable [ 20 ]. In this embodiment, each body half [ 74 , 76 ] can have a semi-circular aperture that form receiving aperture [ 61 ] when the body halves [ 74 , 76 ] are mated. Receiving aperture [ 61 ] is preferably sized to accommodate frangible support element [ 60 ].
[0027] In order to install the power cable [ 20 ] within the coiled tubing [ 10 ], the user pulls the power cable [ 20 ] through the coiled tubing [ 10 ] while anchor assembly [ 50 ] is secured in its compressed state. In one embodiment, once the power cable [ 20 ] is in place, the user can then apply heat to coiled tubing [ 10 ], preferably localized heat located near each anchor assembly [ 50 ], for example with a controlled induction heater, such that frangible support elements [ 60 ] melt, allowing engagement members [ 52 , 54 ] to spring open, thereby engaging inner wall [ 13 ] of coiled tubing [ 10 ]. In other embodiments of the present invention, a solvent can be pumped through the coiled tubing [ 10 ] and contact frangible support elements [ 60 ], causing frangible support elements [ 60 ] to dissolve or weaken to the point frangible support elements [ 60 ] shear and release engaging members [ 52 , 54 ] from their compressed state. In embodiments using heat to shear frangible support element [ 60 ], a solder having a liquidous temperature below the temperature that can harm the power cable can be used, and preferably a eutectic solder can be used. In one embodiment, frangible support element [ 60 ] has a fail temperature around 300 ° F. In embodiments wherein frangible support element [ 60 ] can be dissolved, a number of plastics are acceptable, for example, polypropylene or nylon.
[0028] The invention has significant advantages as embodiments of the present invention do not require the user to make indentions along the length of the coiled tubing, which can be time consuming, imprecise, and damaging to the power cable.
[0029] While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.
[0030] The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims. For example, screws can be added in various places to add additional stability. For instance, screws can be added on the flanges to ensure tight contact with the power cable. Additionally, the anchor assembly could be screwed into the body member. While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention. Additionally, the present invention may suitably comprise, consist or consist essentially of the elements disclosed and can be practiced in the absence of an element not disclosed. It is intended that all such variations within the scope and spirit of the invention be included within the scope of the appended claims. | An electrical line for installation in a well for transmitting power to a well pump includes a string of coiled tubing. An electrical cable having insulated electrical conductors embedded within an elastomeric jacket extends longitudinally through the interior passage of the tubing. Body members are placed around the outer periphery of the electrical cable, and the body members are compressed onto the electrical cable through the use of an anchor assembly. The anchor assembly is held in a compressed state through the use of frangible support elements. Once the electrical cable is in place within the coiled tubing, the user applies an external force to cause the support elements to fail, thereby releasing the anchor assembly from its compressed state. The anchor assembly contacts the inner wall of the coiled tubing, such that the weight of the electrical cable is transferred to coiled tubing. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates to a rotary apparatus and related methods for pressing or cutting articles. More specifically, this invention relates to a rotary pressing assembly configured to reduce the stress upon the pressing member when performing a pressing operation on articles which have a variation in surface area, density or thickness. Even more specifically, this invention relates to a rotary knife assembly configured to reduce the stress upon the knife blade while cutting a plurality of articles from a sheet or web of material.
BACKGROUND OF THE INVENTION
[0002] A typical rotary knife can be described as a “cookie cutter” wrapped three-dimensionally around a cylinder to form a knife roll. The cylindrical cutting surface of the knife roll is pushed into intimate contact with an anvil roll. Material that is fed between the knife roll and the anvil roll is progressively “crush-cut” or “die-cut.” A sharpened cutting edge of the knife roll typically has a flat width of between about 0.002″ (0.005 cm) to about 0.004″ (0.010 cm) and an included angle of between 60° and 110°. When such a knife cutting edge makes peripheral cuts, the surface area of the material being cut varies. This variation is significant between end cut regions relative to side cut regions. Since the loading on the knife cutting edge changes in direct proportion to the area being cut, the knife cutting edge is under higher stress while cutting a smaller surface area of material. This situation leads to a shortened knife roll life as this repeated stress causes damage to the knife cutting edge.
[0003] Ideally, during the progressive cutting action of the knife-edges, the cutting pressure (P) should remain constant. Cutting pressure is a function of the force (F) per unit area (A) as per the following mathematical relationship:
P=F/A
[0004] With constant cutting pressure, stress (σ) on the knife material also would remain constant.
[0005] The instantaneous area of cut, which is the area of knife-edge in contact with the anvil roll, changes significantly due to the varying shape(s) of the products being cut. For example, a greater area of cut is found typically when the knife-edge is predominantly aligned with the rotational axis of the knife roll (usually, at the end cut knife-edge region). Conversely, a significantly smaller area of cut occurs when the knife-edge is predominantly aligned perpendicularly to the rotational axis of the knife roll (usually, at the side cut knife-edge region). The ratio of these instantaneous cut areas can typically be as great as 40: 1, depending upon how the area is measured. This variation in instantaneous area of cut corresponds to variations in stress on the knife material—when the area is the greatest the stress is the lowest and vice versa.
[0006] Additional force is required to make the end-cuts where the area of cut is large (where the cutting edges are predominantly parallel to the rotational axis of the knife). That is, the force on the knife-edge must be made sufficiently large to yield satisfactory cuts being made in this end-cut region. This force generated by the loading mechanism is typically applied on the bearing journals at each side of the roll's working surface.
[0007] Once that force is set for the knife apparatus, it remains constant throughout each cutting operation. As a result, when the knife apparatus is performing cuts in a side region, and the area of cut is small, the pressure on this section of the knife blade is significantly increased. A further consequence is that barring catastrophic failure, knives nearly always prematurely fail at this side cut section.
[0008] The above discussion addressed variations in knife-edge pressure relating to variations in the surface area being cut. These pressure variations also occur where, for example, a finished product is being cut and that article has variations in thickness, density, or composition of materials in the area being cut. Any variations in pressure on the knife cutting edge contribute to the above described stress and premature failure of the knife.
[0009] In addition to the direct cost of repair or replacement of the knife roll, premature failure of a knife cutting edge has additional associated costs. One example of which is the down time required for the replacement and adjustment of the new knife roll. In a high-speed line operation this down time may result in a significant cost factor. Further, a cutting operation failure may necessitate discarding partially completed products along the line. This also may be significant depending upon the value of the product being produced. Clearly, a need exists to reduce the premature failure of rotary knives.
[0010] Various methods have been used to address this premature failure of rotary knife blades. Typically, these include use of damping materials in the fabrication of the rotary modules, using stronger materials such as tungsten carbide in the construction of the knife, and also by using peripheral devices such as air cylinders, springs, and mechanical devices incorporating load cells and automatic feedback controls (cf. U.S. Pat. No. 6,158,316 issued Dec. 12, 2000 to Ichikawa et al., U.S. Pat. No. 4,364,293 issued Dec. 21, 1982 to Hirsch, U.S. Pat. No. 4,962,683 issued Oct. 16, 1990 to Scheffer et al., and WIPO Publication WO 01/19573 dated Mar. 22, 2001). These methods have met with limited success. While use of expensive, stronger materials, such as tungsten carbide, seem to reduce the effects of the problem in some situations, the ability for these materials to satisfactorily compensate for stress variations are frequently exceeded.
[0011] The present invention overcomes these problems of the conventional technology as described above by modifying the bearer rings of a rotary knife apparatus in a way that results in reduced variations in stress on a rotary knife's cutting edge and thereby prolongs the life of the knife roll.
[0012] Further, the present invention is applicable to any rotary pressing operation in which bearer rings are employed. That is, the invention reduces variations in stress on a pressing head. Reduction of these variations reduces wear on the pressing head and thereby prolongs its life. Further, it results in a more uniform pressing operation yielding, for example in a channeling operation, a more uniform depth of channels.
SUMMARY OF THE INVENTION
[0013] It is an object of this invention to reduce stress variations upon a pressing head in a rotary pressing operation. Particularly, it is an object of this invention to modify the bearer rings of a rotary pressing apparatus to provide increased pressure at select locations when it is needed in the rotary pressing operation. More particularly, it is an object of this invention to modify the bearer rings of a rotary knife apparatus to reduce stress on the knife blade during the cutting of areas of reduced surface area.
[0014] In accordance with the present invention, there is provided a rotary knife apparatus for performing a cutting operation on a material, the rotary knife apparatus comprising a knife roll comprising a rotary shaft, wherein the rotary shaft comprises a rotational axis and an outer perimeter, wherein the outer perimeter comprises at least one knife blade and two bearer rings positioned on opposite sides of the knife blade; an anvil roll positioned such that a contact area exists between the anvil roll and each of the bearer rings, and further positioned such that during the cutting operation, pressure exists between the anvil roll and at least a part of the knife blade and between the anvil roll and each contact area; and, means for adjusting the pressure between the knife blade and the anvil roll by modifying at least one of the contact areas.
[0015] Also provided in accordance with the present invention is a rotary apparatus for performing a pressing operation on a material which is positioned between a pressing member and an anvil roll, the rotary apparatus comprising a first rotary member comprising a rotary shaft, wherein the rotary shaft comprises a rotational axis and an outer perimeter, wherein the outer perimeter comprises the pressing member and two bearer rings positioned on opposite sides of the pressing member; the anvil roll positioned such that during the pressing operation, a contact area exists between the anvil roll and each of the bearer rings, and further positioned such that pressure exists between the anvil roll, at least a part of the pressing member, and the material; and, a means for adjusting the pressure by modifying at least one of the contact areas.
[0016] Still further provided in accordance with the present invention is a method for performing a pressing operation on a material which is positioned between a pressing member and an anvil roll, said method comprising the steps of providing a first rotary member comprising a rotary shaft, wherein the rotary shaft comprises a rotational axis and an outer perimeter, wherein the outer perimeter comprises the pressing member and two bearer rings positioned on opposite sides of the pressing member; the anvil roll positioned such that during the pressing operation a contact area exists between the anvil roll and each of the bearer rings, and further positioned such that pressure exists between the anvil roll, at least a part of the pressing member and the material; and, adjusting the pressure by modifying at least one of the contact areas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed that the present invention will be better understood from the following description in conjunction with the following drawings, in which like reference numbers identify identical elements and wherein:
[0018] [0018]FIG. 1 a is a schematic of a rotary knife apparatus;
[0019] [0019]FIG. 1 b is a cross-sectional view of a typical rotary knife apparatus depicted in FIG. 1 a , illustrating examples of minimum knife-edge contact area and maximum knife-edge contact area;
[0020] [0020]FIG. 2 illustrates in both table and graph form the knife cut segment area as a function of the distance from the product end;
[0021] [0021]FIG. 3 is a plan view of the knife/bearer ring surface of an embodiment the present invention;
[0022] [0022]FIG. 4 a is a detailed plan view of a bearer ring notch;
[0023] [0023]FIG. 4 b is a cross-sectional view of the notch of FIG. 4 a taken through the lines A-A;
[0024] [0024]FIG. 5 is a plan view of the knife/bearer ring surface of an alternative embodiment the present invention;
[0025] [0025]FIG. 6 is a plan view of the heat seal roll bearer ring surface of an alternative embodiment the present invention;
[0026] [0026]FIG. 7 is a plan view of the heat seal roll bearer ring surface of an alternative embodiment the present invention;
[0027] [0027]FIG. 8 is a plan view of the channeling bearer ring surface of an alternative embodiment of the present invention;
[0028] [0028]FIG. 9 is a plan view of the channeling bearer ring surface of an alternative embodiment of the present invention; and
[0029] [0029]FIG. 10 is a plan view of the channeling bearer ring surface of an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention is employed to reduce stress variations upon a pressing head in a rotary pressing operation. This is achieved by modifying the bearer rings of a rotary pressing apparatus to provide increased pressure at select locations when it is needed in the rotary pressing operation. The following detailed description will first address this invention as it relates to a rotary knife apparatus.
[0031] [0031]FIG. 1 a depicts a typical rotary knife apparatus for use in the manufacture of sanitary napkins. For the sake of simplification of the following discussion, we will only address the situation depicted in FIG. 1 a where the end cut region 16 is parallel to the rotational axis 14 . Of course, if the napkins were being cut in a transverse direction, the greatest area of knife blade stress would then be on the long edge (now oriented in the direction parallel to the rotational axis) and a similar analysis would apply.
[0032] [0032]FIG. 1 b is a cross-sectional view of this rotary knife where the side cut section of the knife blade 18 is in contact with the anvil roll 12 . This represents the minimum area of cutting contact. For comparison the end cut knife-edge 18 , the maximum area of contact, is also depicted in this FIG. 1 b . It should be noted that FIG. 1 b shows these minimum and maximum areas positioned 180° relative to each other. This angular relationship may be different in real-life situations.
[0033] [0033]FIG. 2 graphically depicts in tabular and graphical form how significantly the area being cut (knife cut segment area) varies. At the end of the product (a tangent to which is parallel to rotational roll axis) the area is high. The area drops very quickly to a much lower value as a function of distance from the end cut. It is interesting to note that the area ratio increases as the radius of curvature of the cut perpendicular to the roll axis approaches infinity. The worst case (highest area ratio) would yield a rectangular product where a straight end cut that is parallel to the rotational axis of the knife roll. The best case (lowest area ratio) is a product whose end radius is zero, and the end of the product comes to a point.
[0034] An easy proof that this phenomenon occurs is that when a new knife has not yet been fully loaded to make a complete cut, only those areas perpendicular to the roll axis will cut the material. Complete cutting is accomplished by increasing the load between the knife roll and the anvil roll. If the area of cut were constant then the entire knife surface would cut all at once and no additional adjustment (load increase) would be necessary.
[0035] Accordingly, a minimum level of loading of the knife needs to be attained to permit satisfactory cutting of regions having relatively high surface area. However, increasing the loading between the knife roll and the anvil roll results in disruptions to the overall system. Energy is stored in the members that make-up the rotary knife apparatus. For example, the loading screws or the air cylinder rods compress and shorten, the top plate bends, the four posts stretch, the rolls bend away from each other, the bearer rings form flat areas where they touch the anvil roll, etc. Each mechanical part has a Modulus of Elasticity, a Poisson's ratio and many varying cross-sections and configurations. All yield and deflect some amount (x) under load. Each part may be thought of as a spring having a spring constant (k). The total knife apparatus being composed of many such springs, some in series and others in parallel to each other. The basic mathematical relationship of a spring is Hooke's law that follows the relationship:
F=kx
[0036] If one were to mathematically add together all the spring deflections, one could arrive at one resultant spring that equaled all the others put together. Using the deflection of that one spring, one can compute the resultant work done by the spring on a body that compresses it as the product of the average force and that deflection, i.e.:
E= ½( kx 2 )
[0037] There are two relevant conditions: (1) the force required to cut the product sides (being relatively small) and (2) the increased force to cut the product ends (being relatively large). The additional energy that is required to generate the force necessary to cut the end of the product is momentarily stored in the knife system spring(s). As the knife roll rotates to a lower knife contact area (having reduced product area to be cut), this stored energy is dynamically “reflected” back onto the reduced-area knife-edge material. In this way it is possible to exceed the elastic limit of the knife and/or anvil material at the reduced area of contact thereby resulting in damage and reducing knife-life.
[0038] One possible solution to this problem is to make a rotary knife system that is exceedingly stiff with a very high overall spring rate. In this way, in the relationship P=F/A as the area (A) changes the force (F) would automatically change also, thereby keeping the cutting pressure (P) a constant. Since the deflection (x) of the combined spring would be very small, very little extra energy would be stored to provide for the increased force required to cut the ends of the product. This solution is difficult to achieve and would result in an enormously ungainly module, very difficult to maintain in present machines.
[0039] When stored energy is considered it is assumed that there is movement in the system. The deflection (x) of the various parts comprising the rotary knife module has already been discussed. One can imagine that all the elastic members move, “breathe” up and down, in and out, as the dynamic cutting force change as a function of cutting area. One embodiment of the present invention addresses this problem by utilizing a particular elastic deformation—the deformation of the cylindrical surfaces of the bearer rings against the anvil roll. When two cylinders are pressed against each other under load, two things occur:
[0040] 1. A flat area is generated whose width (2b) can be calculated as a function of the face-width (L) of the shorter cylinder, the net force (F) pressing them together, the diameters of the two cylinders (D1, D2), the modulus of elasticity of each of the cylinders (E1 , E2) and their Poisson's ratio (v1, v2)
[0041] 2. Corresponding to the flat area generated, the axes of the two cylinders approach each other by the amount (Δx).
[0042] The mathematical relationship of these parameters can be expressed in the following formulae (from Standard Handbook of Machine Design, Joseph E. Shigley and Charles R. Mischke, McGraw Hill 1986, page 13-41):
b = ( 2 · F ) ( π · L ) · ( 1 - v1 2 ) E1 + ( 1 - v2 2 ) E2 ( 1 D1 ) + ( 1 D2 ) Δ x = 2 · F π · L · [ ( 1 - v1 2 ) E1 + ( 1 - v2 2 ) E2 ] · [ ln ( D1 b ) + ln ( D2 b ) + 2 3 ]
[0043] Dynamically, the flat cylinder interface width (2b) and the corresponding change in cylinder distance (Δx) move continually between the two conditions. The load sharing between the bearer rings and the knife cutting edges are also very dynamic and difficult to determine.
[0044] In an embodiment of the present invention the face width of the bearer rings is selectively modified so that the load sharing between the bearer rings and the cutting edges result in a satisfactory cutting pressure. That is, by reducing the bearer ring width as the end-cut is made, the force on the bearer ring is suddenly distributed over a smaller area thus increasing the flat-spot width (2b) and decreasing the distance between anvil and knife roll axes (Δx). This results in the temporary shifting more of the load onto the knife cutting surfaces when it is required.
[0045] This embodiment of the invention in which the bearer ring face width is so modified is depicted in FIG. 3. FIG. 3 illustrates an “opened” view of the bearer ring 20 and knife surface. As shown notches 32 appear in each of the bearer rings at selective locations that coincide with the end cut knife-edge 16 . This results in additional pressure being applied to the knife-edge to perform cuts of areas of increased surface area. It should be noted that similarly, increased pressure could be selectively applied to perform cutting of specific areas of increased thickness and/or density.
[0046] [0046]FIGS. 4 a and 4 b depict detail dimensions of these notches in a further embodiment of the invention based on a 30 mm wide bearer ring. These dimensions are based upon a Finite Element Analysis (FEA) modeling of stresses during a cutting operation using a typical knife roll-anvil roll combination as depicted in FIG. 1. The notches, or reduced surfaces, are quite narrow due to the sudden change in cutting surface area and are shaped to correspond to the graph in FIG. 2.
[0047] An additional feature of the embodiment of the invention depicted in FIG. 4 a is the presence of a ramped opening 42 to the bearer ring notch 32 . As this section of the bearer ring rotates into contact with the anvil roll this ramping lessens the severity of the change in bearing ring surface area and consequently change in resulting force. Further, the presence of a symmetrical ramp at the opposing side of the notch reduces the impact of the knife roll against that edge as it rotates past the notch. That is, this ramping is employed to reduce the shocks to the system not unlike a car tire entering and exiting a pothole.
[0048] The reduced surface areas of the bearing rings are not limited to the notches depicted in FIG. 3. In particular, the configuration of the reliefs in the bearer rings can be changed in amount, size and orientation to create different ratios of area reduction. This may or may not exactly match the load sharing between the bearer rings and the cutting edges, but helps reduce the difference between the required cutting pressures for various points of the cutting edge. By way of example, an alternative embodiment of the invention is depicted in FIG. 5 wherein the reduced surface area of the bearer rings is attained by a cross hatch pattern 52 located on the bearer ring surface at the appropriate locations.
[0049] A further alternative embodiment (not pictured) reduces the area of contact between the anvil and the bearer rings by modifying the anvil roll surface. That is, a configuration of relieved areas on the anvil roll surface (with or without modifying the bearer rings) would be employed. An example of which would be cross-hatched areas. Although any relieved anvil surface that modifies the anvil surface to create depressed areas and thereby reduces the surface area of contact with the anvil roll would yield the same beneficial results provided these areas were appropriately positioned and timed to coordinate with the variations in cutting surface areas. It is well known in the art to perform such timing coordination by means of gears or belts.
[0050] While the above discussions address embodiments in which a cutting operation is being performed, the present invention is not so limited. In particular, it is envisioned that any operation employing bearer rings in which a pressing operation is performed against an anvil can make use of the present invention. Examples of such operations are cutting, scoring, sealing, rolling, embossing, channeling, crimping, calendering, and the like. As with the cutting operation, the invention would minimize variations in pressure that occur as a result in variations of the surface area of the material being operated upon. This would help minimize stress and wear on the heads performing the operation and yield a more even application on the resulting product.
[0051] For example, FIG. 6 depicts a heat sealing operation being performed on women's sanitary napkins. In particular, FIG. 6 is an opened view of a heat seal roll with scalloped or notched bearer rings. As in the cutting operation illustrated in FIG. 3, notches 32 appear in each of the bearer rings 20 to coincide with end of napkin regions 64 to thereby increase pressure on the heat sealing head at this location. This increase in pressure is being applied at these locations to correlate with the increased surface area of the material being sealed. Similarly, increased pressure is provided, via additional notches 32 , to heat seal the increased surface area of the napkin wing edges that are essentially perpendicular to the machine direction.
[0052] [0052]FIG. 7 illustrates another embodiment of the invention which addresses changes in material thickness in a heat sealing operation. FIG. 7 depicts a heat sealing operation being performed on sanitary napkins. In such a heat sealing operation, the heat seal head lies beneath the bearer ring surfaces. In this manner pressure is applied to the material being sealed without the heat seal head coming in contact with the anvil roll. This differs from the knife cutting operation depicted in FIG. 1 b, in which the knife edge 18 is essentially on the same level of the bearer ring surface 20 .
[0053] A problem occurs in the sealing operation when a material of decreased thickness is encountered. The distance between the heat seal head and the anvil roll may be too large to permit a satisfactory seal. Depending on the thickness variation, it may be possible to adjust the apparatus by increasing pressure to satisfactorily address the areas of smaller thickness. However, such an adjustment will result in larger stresses on the heat sealing head when thicker areas are sealed. This results in reduced head life and a less uniform sealing operation.
[0054] The embodiment of the invention depicted in FIG. 7 adjusts for design differences in thickness of the material to be heat sealed by modifying the bearer rings. The illustrated sanitary napkins comprise two materials, items 72 and 74 . Item 74 is present throughout the napkin will item 72 is added essentially to the central region of the napkin. Thus, the napkin wing area 66 has a reduced thickness as it does not contain material 72 .
[0055] As in FIG. 6, notches are provided to yield increased pressure when increased surface area is being embossed (e.g., the napkin end region 64 ). In addition, there is an area of reduced width of the bearer rings 78 to compensate for the reduced thickness of the wing area 66 . That is, the width of the bearer ring is reduced from the width 76 used in a uniformly thick napkin, to a reduced width 78 . As discussed above with respect to a knife edge, reducing the bearer ring width in this manner results in the force on the bearer ring being suddenly distributed over a smaller area thus increasing the flat-spot width (2b) and decreasing the distance between anvil and the heat seal head (Δx). In this manner the present invention adjusts to perform heat sealing of reduced thickness of material.
[0056] This aspect of the invention is not just applicable to heat sealing. It is envisioned that this feature of the invention can be employed in other sealing operations as well as operations related to rolling, embossing, channeling, scoring, crimping and calendering.
[0057] [0057]FIG. 8 illustrates such an additional embodiment of the invention in which channeling is being performed. In this embodiment two types of channels areas are depicted—areas 82 essentially occurring in the machine direction, and areas 84 essentially occurring in a direction perpendicular to the machine direction. As with the cutting and sealing operations discussed above, additional pressure is required to channel the larger surface areas associated with areas 84 . This embodiment of the invention again employs notches 32 in the bearer rings 20 to provide additional pressure at only the 84 areas as the napkin is being channeled.
[0058] [0058]FIGS. 9 and 10 illustrate additional embodiments of the invention in which channeling is being performed. In these Figures more complicated patterns are being channeled and pressure on the channeling head is adjusted by a combination of notches 32 and areas of reduced bearer ring width in a manner analogous to the sealing operation depicted in FIG. 7.
[0059] While the above description of the invention related chiefly to the construction of sanitary napkins, the invention is not limited to sanitary napkins nor to the particular materials used in sanitary napkin construction. It is envisioned that the present invention is applicable to any operation utilizing a pressing operation against an anvil roll where bearer rings are employed. Such an anvil roll need not be a smooth surface, as by way of example, male/female embossing is contemplated by the invention. Further, the present invention is applicable to a wide variety of materials, including, but not limited to, foils, plastics, nonwovens, paper goods, and miscellaneous rolled goods.
[0060] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | This invention relates to a rotary apparatus and related methods for pressing or cutting articles. More specifically, this invention relates to a rotary pressing assembly configured to reduce the stress upon the pressing member when performing a pressing operation on articles which have a variation in surface area, density or thickness. Even more specifically, this invention relates to a rotary knife assembly configured to reduce the stress upon the knife blade while cutting a plurality of articles from a sheet or web of material. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 11/468,631, filed Aug. 30, 2006, which is continuation-in-part of U.S. patent application Ser. No. 11/263,753, filed Oct. 31, 2005, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention generally relate to controlling the flow of fluids and gases in a wellbore. More particularly, the present invention relates to a valve for selectively closing a flow path in a single direction.
[0004] 2. Description of the Related Art
[0005] Generally, a completion string may be positioned in a well to produce fluids from one or more formation zones. Completion devices may include casing, tubing, packers, valves, pumps, sand control equipment, and other equipment to control the production of hydrocarbons. During production, fluid flows from a reservoir through perforations and casing openings into the wellbore and up a production tubing to the surface. The reservoir may be at a sufficiently high pressure such that natural flow may occur despite the presence of opposing pressure from the fluid column present in the production tubing. However, over the life of a reservoir, pressure declines may be experienced as the reservoir becomes depleted. When the pressure of the reservoir is insufficient for natural flow, artificial lift systems may be used to enhance production. Various artificial lift mechanisms may include pumps, gas lift mechanisms, and other mechanisms. One type of pump is the electrical submersible pump (ESP).
[0006] An ESP normally has a centrifugal pump with a large number of stages of impellers and diffusers. The pump is driven by a downhole motor, which is typically a large three-phase AC motor. A seal section separates the motor from the pump for equalizing internal pressure of lubricant within the motor to that of the well bore. Often, additional components may be included, such as a gas separator, a sand separator, and a pressure and temperature measuring module. Large ESP assemblies may exceed 100 feet in length.
[0007] The ESP is typically installed by securing it to a string of production tubing and lowering the ESP assembly into the well. The string of production tubing may be made up of sections of pipe, each being about 30 feet in length.
[0008] If the ESP fails, the ESP may need to be removed from the wellbore for repair at the surface. Such repair may take an extended amount of time, e.g., days or weeks. Typically, a conventional check valve is positioned below the ESP to control the flow of fluid in the wellbore while the ESP is being repaired. The check valve generally includes a seat and a ball, whereby the ball moves off the seat when the valve is open to allow formation fluid to move toward the surface of the wellbore and the ball contacts and creates a seal with the seat when the valve is closed to restrict the flow of formation fluid in the wellbore.
[0009] Gas lift is another process used to artificially lift oil or water from wells where there is insufficient reservoir pressure to produce the well. The process involves injecting gas through the tubing-casing annulus. Injected gas aerates the fluid to make it less dense; the formation pressure is then able to lift the oil column and forces the fluid out of the wellbore. Gas may be injected continuously or intermittently, depending on the producing characteristics of the well and the arrangement of the gas-lift equipment.
[0010] The amount of gas to be injected to maximize oil production varies based on well conditions and geometries. Too much or too little injected gas will result in less than maximum production. Generally, the optimal amount of injected gas is determined by well tests, where the rate of injection is varied and liquid production (oil and perhaps water) is measured.
[0011] Although the gas is recovered from the oil at a later separation stage, the process requires energy to drive a compressor in order to raise the pressure of the gas to a level where it can be re-injected.
[0012] The gas-lift mandrel is a device installed in the tubing string of a gas-lift well onto which or into which a gas-lift valve is fitted. There are two common types of mandrel. In the conventional gas-lift mandrel, the gas-lift valve is installed as the tubing is placed in the well. Thus, to replace or repair the valve, the tubing string must be pulled. In the “sidepocket” mandrel, however, the valve is installed and removed by wireline while the mandrel is still in the well, eliminating the need to pull the tubing to repair or replace the valve.
[0013] Like other valves discussed herein, gas lift valves are typically “one way” valves and rely on a check valve to prevent gas from traveling back into the annulus once it is injected into a tubing string.
[0014] Although the conventional check valve is capable of preventing the flow of fluid in a single direction, there are several problems in using the conventional check valve in this type of arrangement. First, the seat of the check valve has a smaller inner diameter than the bore of the production tubing, thereby restricting the flow of fluid through the production tubing. Second, the ball of the check valve is always in the flow path of the formation fluid exiting the wellbore which results in the erosion of the ball. This erosion may affect the ability of the ball to interact with the seat to close the valve and restrict the flow of fluid in the wellbore.
[0015] Therefore, a need exists in the art for an improved apparatus and method for controlling the flow of fluid and gas in a wellbore.
SUMMARY OF THE INVENTION
[0016] The present invention generally relates to controlling the flow of fluids and gases in a wellbore. In one aspect, a valve for selectively closing a flow path in a first direction is provided. The valve includes a body and a piston surface formable across the flow path in the first direction. The piston surface is formed at an end of a shiftable member annularly disposed in the body. The valve further includes a flapper member, the flapper member closable to seal the flow path when the shiftable member moves from a first position to a second position due to fluid flow acting on the piston surface.
[0017] In another aspect, a valve for selectively closing a flow path through a wellbore in a single direction is provided. The valve includes a housing and a variable piston surface area formable across the flow path in the single direction. The valve also includes a flow tube axially movable within the housing between a first and a second position, wherein the variable piston surface is operatively attached to the flow tube. Further, the valve includes a flapper for closing the flow path through the valve upon movement of the flow tube to the second position.
[0018] In yet another aspect, a method for selectively closing a flow path through a wellbore in a first direction is provided. The method includes positioning a valve in the wellbore, wherein the valve has a body, a formable piston surface at an end of a shiftable member, and a flapper member. The method further includes reducing the flow in the first direction, thereby forming the piston surface. Further, the method includes commencing a flow in a second direction against the piston surface to move the shiftable member away from a position adjacent the flapper member. Additionally, the method includes closing the flapper member to seal the flow path through the wellbore.
[0019] In another embodiment, a valve embodying aspects of the invention is used in a gas lift arrangement to prevent the back flow of oil or gas injected into a tubing string from an annular area while reducing any obstruction of flow through the gas lift apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of 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.
[0021] FIG. 1 is a view illustrating a control valve disposed in a wellbore.
[0022] FIG. 2 is a view illustrating the valve in an open position.
[0023] FIG. 3 is a view illustrating the piston surface formed in a bore of the valve.
[0024] FIG. 4 is a view taken along line 4 - 4 of FIG. 3 to illustrate the piston surface.
[0025] FIG. 5 is a view illustrating the valve in the closed position.
[0026] FIG. 6 is a view illustrating a sidepocket mandrel assembly for use in a gas lift well.
[0027] FIG. 7 is a view taken along line 7 - 7 of FIG. 6 .
DETAILED DESCRIPTION
[0028] FIG. 1 is a view illustrating a control valve 100 disposed in a wellbore 10 . As shown, the control valve 100 is in a lower completion assembly disposed in a string of tubulars 30 inside a casing 25 . An electrical submersible pump 15 may be disposed above the control valve 100 in an upper completion assembly. As illustrated, a polished bore receptacle and seal assembly 40 may be used to interconnect the electrical submersible pump 15 to the valve 100 and a packer arrangement 45 may be used to seal an annulus formed between the valve 100 and the casing 25 . Generally, the valve 100 is used to isolate the lower completion assembly from the upper completion assembly when a mechanism in the upper completion assembly, such as the pump 15 , requires modification or removal from the wellbore 10 .
[0029] The electrical submersible pump 15 serves as an artificial lift mechanism, driving production fluids from the bottom of the wellbore 10 through production tubing 35 to the surface. Although embodiments of the invention are described with reference to an electrical submersible pump, other embodiments contemplate the use of other types of artificial lift mechanisms commonly known by persons of ordinary skill in the art. Further, the valve 100 may be used in conjunction with other types of downhole tools without departing from principles of the present invention.
[0030] FIG. 2 is a view of the valve 100 in an open position. The valve 100 includes a top sub 170 and a bottom sub 175 . The top 170 and bottom 175 subs are configured to be threadedly connected in series with the other downhole tubing. The valve 100 further includes a housing 105 disposed intermediate the top 170 and bottom 175 subs. The housing 105 defines a tubular body that serves as a housing for the valve 100 . Additionally, the valve 100 includes a bore 110 to allow fluid, such as hydrocarbons, to flow through the valve 100 during a production operation.
[0031] The valve 100 includes a piston surface 125 that is formable in the bore 110 of the valve 100 . The piston surface 125 shown in FIG. 2 is in an unformed state. The piston surface 125 is maintained in the unformed state by a fluid force acting on the piston surface 125 created by fluid flow through the bore 110 of the valve 100 in the direction indicated by arrow 115 . The piston surface 125 generally includes three individual members 120 . Each member 120 has an end that is rotationally attached to a flow tube 155 by a pin 195 and each member 120 is biased rotationally inward toward the center of the valve 100 . Additionally, each member 120 is made from a material that is capable of withstanding the downhole environment, such as a metallic material or a composite material. Optionally, the members 120 may be coated with an abrasion resistant material.
[0032] As illustrated in FIG. 2 , the valve 100 also may include a biasing member 130 . In one embodiment, the biasing member 130 defines a spring. The biasing member 130 resides in a chamber 160 defined between the flow tube 155 and the housing 105 . A lower end of the biasing member 130 abuts a spring spacer 165 . An upper end of the biasing member 130 abuts a shoulder 180 formed on the flow tube 155 . The biasing member 130 operates in compression to bias the flow tube 155 in a first position. Movement of the flow tube 155 from the first position to a second position compresses the biasing member 130 against the spring spacer 165 .
[0033] The valve 100 further includes a flapper member 150 configured to seal the bore 110 of the valve 100 . The flapper member 150 is rotationally attached by a pin 190 to a portion of the housing 105 . The flapper member 150 pivots between an open position and a closed position in response to movement of the flow tube 155 . In the open position, a fluid pathway is created through the bore 110 , thereby allowing the flow of fluid through the valve 100 . Conversely, in the closed position, the flapper member 150 blocks the fluid pathway through the bore 110 , thereby preventing the flow of fluid through the valve 100 .
[0034] As shown in FIG. 2 , a upper portion of the flow tube 155 is disposed adjacent the flapper member 150 . The flow tube 155 is movable longitudinally along the bore 110 of the valve 100 in response to a force on the piston surface 125 . Axial movement of the flow tube 155 , in turn, causes the flapper member 150 to pivot between its open and closed positions. In the open position, the flow tube 155 blocks the movement of the flapper member 150 , thereby causing the flapper member 150 to be maintained in the open position. In the closed position, the flow tube 155 allows the flapper 150 to rotate on the pin 190 and move to the closed position. It should also be noted that the flow tube 155 substantially eliminates the potential of contaminants from interfering with the critical workings of the valve 100 .
[0035] FIG. 3 illustrates the piston surface 125 formed in the bore of the valve 100 . To seal the bore 110 , the flow of fluid through the bore 110 of the valve 100 in the direction indicated by the arrow 115 is reduced. As the flow of fluid is reduced, the fluid force holding the piston surface 125 in the unformed state becomes less than the biasing force on the piston surface 125 . At that point, each member 120 of the piston surface 125 rotates around the pin 195 toward the center of the valve 100 to form the piston surface 125 illustrated in FIG. 4 . After the piston surface 125 is formed, the flow of fluid in the direction indicated by arrow 145 is commenced, thereby creating a force on the piston surface 125 . As the force on the piston surface 125 increases, the force eventually becomes stronger than the force created by the biasing member 130 . At that point, the force on the piston surface 125 urges the flow tube 155 longitudinally along the bore 110 of the valve 100 .
[0036] FIG. 5 is a view illustrating the valve 100 in the closed position. After the piston surface 125 is formed, the flow tube 155 moves axially in the valve 100 . This moves the upper end of the flow tube 155 out of its position adjacent the flapper member 150 . This, in turn, allows the flapper member 150 to pivot into its closed position. In this position, the bore 110 of the valve 100 is sealed, thereby preventing fluid communication through the valve 100 . More specifically, flow tube 155 in the closed position no longer blocks the movement of the flapper member 150 , thereby allowing the flapper member 150 to pivot from the open position to the closed position and seal the bore 110 of the valve 100 .
[0037] The flapper member 150 in the closed position closes the flow of fluid through the bore 110 of the valve 100 , therefore no fluid force in the bore 110 acts on the members 120 . To move the flapper member 150 back to the open position, the flow of fluid in the direction indicated by arrow 145 is reduced and the fluid on top of the flapper member 150 is pumped or sucked off the top of the flapper member 150 . At a predetermined point, the biasing member biasing the flapper member 150 is overcome and subsequently the biasing member 130 extends axially to urge the flow tube 155 longitudinally along the bore 110 until a portion of the flow tube 155 is adjacent the flapper member 150 . In this manner, the flapper member 150 is back to the open position, thereby opening the bore 110 of the valve 100 to flow of fluid therethrough, as illustrated in FIG. 2 .
[0038] In one embodiment, the valve 100 may be locked in the open position as shown in FIG. 2 by disposing a tube (not shown) in the bore 110 of valve 100 . The tube is configured to prevent the axial movement of flow tube 155 from the first position to the second position by preventing the formation of the piston surface 125 . Thus, the flapper member 150 will remain in the open position and the valve 100 will be locked in the open position. To lock the valve 100 , the tube is typically pulled into the bore 110 from a position below the valve 100 . In a similar manner, the valve 100 may be unlocked by removing the tube from the bore 110 of the valve 100 .
[0039] In another embodiment, the valve may be used in a gas lift application to prevent the back flow of gas (or production fluid) as gas is injected into a string or strings of production tubing. In one example, gas lift valves are disposed at various locations along the length of an annulus formed between production tubing and well casing. Gas lift valves are well known in the art and are described in U.S. Pat. No. 6,932,581, which is incorporated by reference in its entirety herein. Pressurized gas is introduced into the annulus from the well surface and when some predetermined pressure differential exists between the annulus and the tubing at a certain location, that valve opens and the gas is injected into the tubing string to lighten the oil and facilitate its rise to the surface of the well. The control valve of the invention is used in conjunction with the gas lift valves to prevent a backflow of gas or fluid from the production tubing to the annulus. Typically, the control valve is located adjacent the gas lift valve in the annulus. The valve permits gas to flow into the gas lift valve when it is open. However, when the gas lift valve closes, the control valve, with its closing members restricts the flow of gas or fluid back toward the annulus.
[0040] In gas lift applications, control valves according to the invention may be fixed in a sidepocket mandrel. A conventional sidepocket mandrel has a pocket bore size of about 1.750 inches and the control valve dimensions are designed accordingly. Employing control valves according to the invention permits fluid path dimensions to be maximized. Thanks to the flapper sealing member, no flow restriction or significant pressure drop occurs across the valve, and a more efficient operation of the pump is possible. Moreover, control valves according to the invention prove more reliable because they do not present any erosion related problems like conventional check valves.
[0041] As illustrated in FIG. 6 , in order to allow a larger amount of gas flowing into the tubing and optimizing the fluid flow path, a sidepocket mandrel 200 may be provided with two lateral bores 210 flowing into a main bore 220 which is connected in correspondence of its lower portion to the inside of the tubing string through a slot (not shown). The lateral bores 210 communicate with the main bore 220 through a drilled portion 230 which crosses the entire cross section of the main bore 220 and projects with its ends respectively into both the lateral bores 210 . Each of the two lateral bores 210 in the sidepocket mandrel is provided with a seat 211 a control valve 100 (not shown) can be threadably connected thereto, whereas the main bore 220 is provided with a conventional gas lift valve (not shown). FIG. 7 illustrates a cross section of the sidepocket mandrel assembly in correspondence of the drilled portion 230 .
[0042] A sidepocket mandrel as shown in FIGS. 6-7 is fixed to a tubing string located inside a wellbore and provided with control valves according to the invention in the respective seats 211 . Pressurizing gas in the annulus between the tubing string and the wellbore and opening the gas lift valve at the same time, initiate gas flowing through the mandrel 200 into the tubing so that the control valves 100 are driven in an open condition, wherein the gas is permitted to flow through the mandrel 200 and exercise the necessary pressure to keep the control valves opened. Two different streams of gas are created respectively inside each lateral bore 210 which finally commingle inside the main bore 220 . The gas then flows downwards inside the main bore 220 and finally enters the tubing string. The total amount of gas flowing through the mandrel 200 is directly dependent on the gas lift valve and, because in the opened condition the control valves do not cause any flow restriction, an optimization of the gas flow is obtained. Once the gas flow is either reduced or stopped the control valves close so as to prevent a backflow of gas or fluid from the production tubing to the annulus. The operation of the control valves according to the invention applied in gas lift applications is the same one as previously described in relation with FIGS. 2 to 5 .
[0043] Although a sidepocket mandrel with two lateral bores has been described hereinabove, it is apparent that with regard to the object of the invention the same considerations here apply for a sidepocket mandrel including only one lateral bore.
[0044] Although the invention has been described in part by making detailed reference to specific embodiments, such detail is intended to be and will be understood to be instructional rather than restrictive. For instance, the valve may be used in an injection well for controlling the flow of fluid therein. It should be also noted that while embodiments of the invention disclosed herein are described in connection with a valve, the embodiments described herein may be used with any well completion equipment, such as a packer, a sliding sleeve, a landing nipple, and the like.
[0045] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | The present invention generally relates to controlling the flow of fluids in a wellbore. In one aspect, a valve for selectively closing a flow path through a wellbore in a first direction is provided. The valve includes a body and a piston surface formable across the flow path in the first direction. The piston surface is formed at an end of a shiftable member annularly disposed in the body. The valve further includes a flapper member, the flapper member closable to seal the flow path when the shiftable member moves from a first position to a second position due to fluid flow acting on the piston surface. In another aspect, a valve for selectively closing a flow path through a wellbore in a single direction is provided. In yet another aspect, a method for selectively closing a flow path through a wellbore in a first direction is provided. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic bearing characterized in having a rotor levitated by electromagnet power and maintained at a certain levitated constant position through detecting its position.
Recently electromagnetic levitation devices which can convey or carry works without contact are utilized for carrier system in such an atmosphere where highly clean conditions must be maintained, like IC manufacturing equipments. In such electromagnetic levitation devices, a magnetic bearing having a rotor which is levitated with electromagnetic power and of which the levitating position is maintained in a certain constant position has been used. FIG. 14 shows a block diagram of a conventional electromagnetic bearing configuration. This kind of electromagnetic bearing has two electromagnets 42a, 42b which are positioned to be facing each other, and two position sensors 43a, 43b. Moreover, the electromagnetic bearing comprises a bridge circuit 44 to which a detecting signal from position sensors 43a, 43b is input, a comparator 46 which compares the output signal from the above bridge circuit 44 with a standard signal 45, a signal processing circuit 47 for processing an output signal of the comparator, and amplifier circuits 48a, 48b that amplify the output signal from the signal processing circuit 47 and transfer its output to electromagnets 42a, 42b.
In this electromagnetic bearing, a rotor 41 is levitated and held in a predetermined position. The position of the rotor is detected by the position sensor 43a, 43b, and a signal that changes according to the position of the rotor 41 is output from the bridge circuit 44 to the comparator 46. By operation the comparator 46, is obtained a signal that changes according to the compared difference of the output signal from the bridge circuit 44 with the standard signal 45, that is, a signal that changes according to the compared difference of the position of the rotor with its standard position, and this signal is then processed by signal processing circuit 47, and then output to the amplifiers 48a, 48b. By the amplifiers 48a, 48b the exciting current is supplied to electromagnets 42a, 42b. The rotor 41 is controlled to be held at a predetermined position as above.
In the prior art electromagnetic bearing, it is technologically difficult to detect the rotor's position with high accuracy using a conventional position sensor and because a position sensor is needed to detect the rotor position there exists a problem in that an expensive sensor of higher accuracy is needed in order to accurately control the rotor position.
And in the prior art electromagnetic levitation system, it is usually the case for holding the position accurately that an integrating element is inserted into the feedback loop. But this kind of an integrating element is more or less an approximate one. For example, it is not possible that direct current gain can not be infinite due to the step output of the operational amplifier when the integrating element is comprised of an analog circuit. And a further deviation is included to a certain degree because of quantization errors in AD conversion and in computer process when the integrating element is comprised by a digital control device. These problems show the existence of a certain limitation in the improvement of sustaining accuracy by arrangement of integrating element in the prior art electromagnetic levitation systems.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an electromagnetic bearing with which higher accuracy positioning can be realized by control with means having a simplified configuration.
The electromagnetic bearing of the present invention comprises an electromagnet to levitate a rotor by way of magnetic power, a hysteresis amplifier to supply an exciting current to the electromagnet, and a position control means to control the position of the rotor with a phase locked loop which controls the switching frequency of the hysteresis amplifier by way of controlling the exciting current to be supplied from the hysteresis amplifier according to the switching phase of the hysteresis amplifier. In this invention, a hysteresis amplifier is used which has characteristics such that its switching frequency changes according to the inductance. Thus, utilizing the fact that the switching frequency of the hysteresis amplifier changes according to the gap between a rotor and an electromagnet, the position of said rotor is detected without a position sensor.
The rotor is kept in a predetermined position by controlling the switching frequency maintain a predetermined constant value using the phase locked loop.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a first embodiment of the electromagnetic bearing in this invention;
FIG. 2 is an explanatory drawing of electromagnet and a rotor in a embodiment;
FIG. 3 shows the wave form drawing which describes the relation between electric current in the electromagnet coil and applied voltage, in the embodiment of FIG. 2;
FIG. 4 is a block diagram which describes the configuration of the hysteresis amplifier shown in FIG. 1;
FIG. 5 shows a character graph of hysteresis comparator characteristics in FIG. 4;
FIG. 6 is a wave form drawing of a current in magnetic coil by way of hysteresis amplifier in FIG. 4;
FIG. 7 is a circuit drawing of the equivalent circuit of electromagnet coil in an embodiment;
FIG. 8 is an explanatory drawing for the purpose of exhibiting current and applied voltage in the circuit of FIG. 7;
FIG. 9 is a wave form drawing of step-wise voltage applied in the circuit of FIG. 8;
FIG. 10 is a graph of characteristics, that exhibits the change in current when step-wise voltage (FIG. 9) in the circuit of FIG. 8 is applied;
FIG. 11 is a electromagnet and a rotor in an embodiment;
FIG. 12 is a block diagram of another configuration of a hysteresis amplifier;
FIG. 13 is a block diagram of a second embodiment of the electromagnetic bearing in accordance with this invention; and
FIG. 14 is a block diagram of a conventional electromagnetic bearing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Hereinafter a preferred embodiment of electromagnetic bearing in this invention will be described referring to FIG. 1 through FIG. 11.
FIG. 1 is a block diagram of an embodiment of a configuration of the electromagnetic bearing in this invention.
As shown in FIG. 1, the electromagnetic bearing in the first embodiment in this invention includes two electromagnets 12a, 12b which are laid out in an opposite direction in each other, both being disposed on opposite sides and facing the center of a rotor 11, hysteresis amplifiers 13a, 13b which supply an exciting current to the said electromagnets 12a, 12b, a phase comparator 14 which detects the phase difference of both switching wave shapes of each hysteresis amplifier 13a, 13b, and a loop filter 15 which supplies to each hysteresis amplifier 13a, 13b direct current to which the output from the said phase comparator 14 is supplied and converted.
In this electromagnetic bearing exciting current is supplied to electromagnets 12a, 12b from hysteresis amplifiers 13a, 13b and with magnetic force (attraction F 1 , F 2 ) of electromagnets 12a, 12b, the rotor 11 is levitated.
And the switching wave form of hysteresis amplifier 13a, 13b is input into phase comparator 14, and the phase difference between both wave forms is detected. The output of the phase comparator 14 is converted through loop filter 15 to a pair direct current outputs, which are respectively supplied to each hysteresis amplifier 13a, 13b. Like the above, a phase locked loop is composed with hysteresis amplifier 13a, 13b phase comparator 14 and loop filter 15, and the position X of the rotor 11 is controlled to be held and maintained at a predetermined position.
In accordance with this embodiment, a hysteresis amplifier 13 (which represents 13a and 13b), that has characteristics in that the switching frequency changes according to inductance, is applied as an amplifier which excites electromagnet 12 (which represents 12a, and 12b). That is to say, the position of a rotor 11 is calculated from the switching wave frequency of the hysteresis amplifier 13, utilizing the change in the switching frequency of the hysteresis amplifier 13 according to the gap (which is the position X of the rotor 11) between electromagnet 12 and the rotor 11. As a result, there is no need for a position sensor.
Again in this embodiment, the switching frequency of the hysteresis amplifier 13 is controlled to be constant using the phase Locked Loop, and therefore a rotor 11 is held and maintained at a certain position. Accordingly, higher precision control of a rotor 11 can be realized through the detectability of control error at phase shift level.
In particular, the integration element of the phase locked loop in this embodiment is ideal in mathematical relation in that phase is equal to the integral of angular frequency. Accordingly, higher precision control can be realized because the above-described error is avoided.
Next, an outline of operation in hysteresis amplifier 13 will be explained referring to FIG. 2, and FIG. 3.
As shown in FIG. 2, V is the voltage charged to the coil of an electromagnet 12, I is current passing through the coil, and X is the gap between electromagnet 12 and a rotor 11.
FIG. 3 shows the drawing of the wave, which exhibits the relationship between the current I and voltage V. Target current value I 0 , and its interval ±ΔI between upper and lower limits are set into the hysteresis amplifier and hysteresis amplifier 13 changes voltage V to -Vm when actual current value attains the upper limit I 0 +ΔI p and to V p when actual current value attains the lower limit I 0 -ΔIm.
In this embodiment, the position of a rotor 11 is detected from the of switching frequency, utilizing the characteristics that the switching frequency of voltage in the hysteresis amplifier is approximately in proportion to the gap between electromagnet 12 and rotor 11.
FIG. 4 is the block diagram of hysteresis amplifier configuration. As shown in FIG. 4, comparison amplifier 21 into which target current value I 0 is input and hysteresis comparator 22 into which output V from the said comparison amplifier is input are equipped in hysteresis amplifier 13. A switching element 23 which receives output voltage V' from hysteresis comparator 22 and switches two level voltage of the source 24 and output into the coil 20 of electromagnet 12, and an electric current detector 25 which detects the current in coil 20 of electromagnet 12 and output into comparison amplifier 21 are also equipped in the above hysteresis amplifier 13.
Target current value I 0 is the preferable value of current which should be in coil 20 of electromagnet, which is, generally speaking, given by the summation of bias current value and current value for control. And this target current value I 0 is supplied by loop filter 15 in FIG. 1.
Comparison amplifier 21 outputs voltage V[V=K v (I 0 -i), where K v is constant], which is proportionate to the difference between the target current value I 0 and current in coil i.
The threshold value of hysteresis comparator 22 changes according to the past history of input signal, and an example of its characteristics is shown in FIG. 5. Suppose that V on and -V OFF corresponds respectively to the higher level and lower level of output voltage V' of the hysteresis comparator 22 that ΔV p is input voltage when output voltage changes from -V OFF to V on , and that -ΔVm is input voltage when output voltage changes from V on to -V OFF .
Switching element 23 is such a element (transistor, FET, thyristor and etc.) that changes its voltage onto the coil 20, from higher voltage (V P ) to negative voltage (-Vm) or sufficiently lower enough voltage (V L ), according to the input signal level (V ON , V OFF ).
By the way, the switching wave form which is supplied to phase comparator 14 in FIG. 1 can be output form of hysteresis comparator 22 or of switching element 23, or the binary wave that is converted from the output of the electric current detector 25.
Next, the operation of hysteresis amplifier 13 will be explained hereunder.
The current in coil 20 fluctuates in chopping wave shape with its center of the target current value I 0 . The reason is as follows.
Suppose at a certain time, that current in coil 20 is I'(I 0 -ΔIm<I'<I 0 ), that V 0 is output voltage of hysteresis comparator 22, and that V p is the voltage applied to the coil 20.
Coil 20 forms a series circuit with inductance L and with resistor R as shown in FIG. 7, where the component values are set such that V p >>(I 0 +ΔI p )/R. In this case, coil current level increases gradually for inductance L of coil 20, and becomes equal to I 0 . At the same time, the output voltage of comparison amplifier also changes in its code (for example, positive to negative). But for some time thereafter, the output of the hysteresis comparator 22 stays at V on because of the hysteresis characteristics of hysteresis comparator 22. Therefore the current increases over I 0 .
In the meantime its output voltage changes to -V off and the voltage supplied to coil 20 also changes from V p to -V m , when the value of the output voltage V of comparison amplifier 21 becomes smaller than -ΔV m . Because of this, the current in coil 20 begins to decrease. Assuming that I 0 +ΔI p is the value of the current at the point where the output of hysteresis comparator 22 changes to -V off , there exists the relation of K v ·ΔI p =ΔV m .
In the meantime, the value of the current decreases to I 0 , but its value decreases furthermore without changing to V ON immediately because of the hysteresis characteristics of the hysteresis comparator 22. And now, since the value of output voltage V of comparison amplifier 21 becomes larger than ΔV p , the output of hysteresis comparator 22 changes to V ON , the voltage charged to coil 20 again turns to Vp, and the value of the current begins to increase. Assuming that I 0 -ΔIm is the value of the current at the point where the output of hysteresis comparator 22 changes to V ON , there exists the relation of K v ·ΔIm=ΔV p .
The hysteresis amplifier 13 repeats the operation above and as shown in FIG. 6, switching cycle T is t 1 +t 2 , and the switching frequency f is 1/T where t 1 is the period during which the current in coil 20 increases from I 0 -ΔIm to I 0 +ΔI p , and where t 2 is the period during which current in coil 20 decreases from I 0 +ΔI p to I 0 -ΔIm.
It will now be explained why the switching frequency of hysteresis amplifier 13 changes approximately in proportion to the gap X between electromagnet 12 and a rotor 11.
As shown in FIG. 8, coil 20 of electromagnet 12 is supposed to be a series connection of Inductance L and resistor R.
Here, suppose that step like voltage Va is charged to the both ends of coil 20 at the initial condition where is the current in coil ia(0)=0. That is to say, Va=0, at the time t<0, and Va=V h , at the time t≧0, as shown in FIG. 9.
Then, the current in coil increases up to the last value (V h /R) as shown in FIG. 10. At slightly above t=0, that is, when ia<<V h /R), the increase rate of the current is (R/L)·(V h /R)=(V h /L).
As mentioned before, when the relation (I 0 +ΔI p )=(V h /R) is satisfied in the operation of hysteresis amplifier 13, t 1 =L(ΔI p +ΔIm)/V h where t 1 is the period during which the current increases from I 0 -ΔIm to I 0 +ΔI p , because (V h /L)·t 1 =(ΔI p +ΔIm).
Likewise, when Vm is chosen such that the relation (I 0 -ΔI p )+(Vm/R)>>I 0 +ΔI p is satisfied, t 2 =L(ΔI p +ΔIm)/Vm where t 2 is the period when the current decreases from I 0 +ΔI p to I 0 -ΔIm.
Therefore, switching cycle T(=t 1 +t 2 ) is may be represented by T=L(ΔI p +ΔIm)·(1/V h +1/Vm).
On the other hand, the value of inductance L of coil 20 in electromagnet 12 is approximately inversely proportional to the gap X between electromagnet 12 and the rotor 11. As shown in detail in FIG. 11, supposing that N is total number of turns of coil 20 of electromagnet 12, that A is the cross sectional area of core 30 and that a rotor 11 is a ferromagnetic body (amplitude permeability μ≈∞), the relation is L≈N 2 A.sub.μo /2X=K L /X, where .sub.μ0 is initial amplitude permeability and K L =N 2 A.sub.μ0 /2.
Therefore the relation becomes to be T=(K L /X)·(ΔI p +ΔIm)·(1/V h +1/Vm), and switching frequency f (=1/T) turns to be f=K'x, but where K'=(V h ·Vm)/[K L (ΔI p +ΔIm) (V h +Vm)]. Therefore, the switching frequency f is approximately in proportion to gap X.
By the way, the present invention is not limited to the above embodiment. For example, although position of a rotor is controlled in the embodiment described above, in such a way that the phase of two hysteresis amplifiers are compared to each other, the position of a rotor may also as well be controlled in such a way that the phase of a hysteresis amplifier is compared with the phase of a reference signal of a predetermined frequency.
FIG. 12 shows block diagram of the different configuration concerning hysteresis amplifier.
In this hysteresis amplifier 113, comparison amplifier 21 shown in FIG. 21 is eliminated, and Target current value I 0 which is supplied from loop filter 15 in FIG. 1 and output of electric current detector 25 are directly input into hysteresis comparator 122. And this hysteresis comparator 122 has a comparison amplification function. That is, hysteresis comparator 122 outputs the voltage V that is in proportion to the difference between the target current value I 0 and coil current i, and is composed such that the threshold value changes according to the past history of output as well as having the hysteresis characteristics as shown in FIG. 5.
FIG. 13 shows the second embodiment of electromagnetic bearing in this invention. For simplification of explanation thereof, the same reference numeral is used to denote the same part as in the first embodiment and duplicate explanation is avoided.
In the second embodiment as shown in FIG. 13 the center of rotating axis of a rotor 11 should be horizontal. Electromagnetic bearing elements include electromagnet 12c which is located above the upper side of a rotor 11, hysteresis amplifier 13c which supplies exciting current to this electromagnet 12c, standard signal generating circuit 131 which outputs a reference or standard signal, phase comparator 14 which detects the phase difference of both wave forms of this standard signal and switching waveform to be input from hysteresis amplifier 13c, and loop filter 15 which supplies direct current to which the output of phase comparator 14 is converted to the hysteresis amplifier 13c.
In this electromagnetic bearing, an exciting current is supplied from the hysteresis amplifier 13c to electromagnet 12c, and with this the attractive force F 1 of the electromagnet 12c is generated to levitate and hold the rotor 11. In here the stationary value of attraction force F 1 of the electromagnet 12c is controlled to maintain the value required to offset the effect of gravity F 2 11 such that the rotor 11 acts upon the rotor which is held at a predetermined position. By the way, either one of the hysteresis amplifier shown in FIG. 4 or shown in FIG. 12 can be used in this second embodiment.
Since the position of the rotor is detected by monitoring the switching frequency of a hysteresis amplifier according to this invention and as explained above, a position sensor is not needed for this purpose and since the control error is detected at the phase level with a phase locked loop, higher precision control of the rotor position can be realized with simple configuration. | By using a hysteresis amplifier for driving an electromagnet, a highly accurate electromagnetic bearing may be produced without the need for independent position detectors to maintain the levitated position of a rotor constant. In one embodiment, the electromagnetic bearing includes multiple electromagnets for levitating a rotor in a predetermined position. Multiple hysteresis amplifiers each supply a switching signal for driving each of the electromagnets. The switching frequency of the switching signals changes in accordance with the inductance of the electromagnets, which varies in accordance with the relative position of the electromagnets. A phase comparator detects the phase difference between the switching waveforms of each hysteresis amplifier. A loop filter supplies a target current value converted from an output of the phase comparator to the hysteresis amplifiers. By controlling the input signals to the respective hysteresis amplifiers to maintain the frequency of the switching signal output of the respective hysteresis amplifiers constant, the position of the rotor is also maintained constant. Accordingly, a magnetic bearing may precisely control the levitated position of a rotor without the use of position detectors. | 5 |
BACKGROUND OF THE INVENTION
This invention relates generally to supports and more particularly to supports in the nature of a post which include apparatus to permit the post to withstand and to recover from a lateral force such as an impact by an automobile or the like.
A number of other inventors have addressed the problem of creating post-type supports or standards which are adapted to withstand and to recover from impact, whether due to an automobile, vandals, high winds, or other external sources. It has been recognized that a resilient spring section provided in such a post-type support permits the support to yield to such an outside force yet rebound to its original erect position once the force is removed. Such post-type supports have found use in connection with mailboxes, parking meters, traffic signs, and the like.
The post-type supports of the prior art, while dealing adequately with the problem of withstanding and recovering from destructive forces have failed to consider the desirability of constructing such a post so as to present a pleasing exterior consistent with the surrounding environment. There has also been little consideration given to constructing such a post which is environmentally compatible yet be simple to assemble by a "do-it-yourself" homeowner or the like.
SUMMARY OF THE INVENTION
In accordance with the present invention, a post for supporting a mailbox or the like comprises an enclosure constructed of a plurality of vertical members including corner-defining members and panel members situated between the corner-defining members. Bracket means are fixed to at least some of the corner-defining members so as to maintain the relative position of the members. Anchor means is provided for engaging the ground and a lower end of the enclosure is situated around the upper end of the anchor means. A biasing means in the form of a spring couples the bracket means to the anchor means. A mounting board is situated across the upper end of the members of the enclosure and is coupled to the bracket means, the mounting board being provided to receive a mailbox, sign, or other objects sought to be supported thereby.
In a preferred embodiment, the post of the present invention is provided in kit form including a pair of side assemblies, each assembly comprising a pair of elongated corner members, a rectangular panel member fixed between the corner members and bracing means fixed to the corner members for bracing each side assembly. Connecting means is provided for connecting the bracing means of one side assembly to the bracing means of another side assembly. The bracing means is adapted to be coupled to an anchor by a spring-biasing means. A mounting board is provided together with means for fastening the mounting board to the connecting means at one end of the pair of side assemblies. The kit includes at least one pair of additional side panels for joining the pair of side assemblies in spaced relation to each other so as to enclose the connecting means and coupling means. The side panels can be of various composition so as to provide the kit purchaser with decorative options.
One feature of the present invention is the use of an auger type anchor which can easily be installed in the ground without the use of a shovel or other digging implement. This feature has the advantage of permitting a "do-it-yourselfer" to install a post of the present construction without having to obtain additional tools and supplies prior to installation of the post.
Another feature of the present invention is the use of bracket means of common design for coupling the enclosure portion of the post to the spring biasing means and to the mounting board situated across the upper end of the members. A common bracing means is also used throughout the apparatus. This feature has the advantage of reducing the number of different parts actually employed in the construction of such a post thereby lowering inventory and design costs.
An additional feature of the present invention is the use of side panels for joining the side assemblies in relationship to each other which are slidably received in slots provided in the elongated corner members. The side panels can be of various construction including wood, metal, plastic, etc. This feature has the advantage of providing the "do-it-yourselfer" with a wide variety of choices for the appearance of the post-type support. It also permits replacement of the side panels at any time, for example, on the occasion of special seasons, holidays, etc.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived. The detailed description particularly refers to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view partially broken away showing a post in accordance with this invention fully assembled.
FIG. 2 is a perspective view of a side assembly intended for use in a kit for the construction of a post in accordance with the present invention.
FIG. 3 is a detailed perspective view of the top portion of the post partially broken away to reveal the installation of the upper bracket.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A supporting post 10 according to the present invention is shown in FIG. 1 to include an enclosure 12 having an upper end 14, a lower end, and an intermediate portion 18. The enclosure 12 is formed from a plurality of cornered defining members 20 which are spaced from each other by rectangular panel members 22. A base plate 24 is provided at the lower end 16 of the enclosure 12 and rests upon the underlying ground 26. The base plate 24 is shown to include a central opening 28. An upper end 30 of anchor means 32 projects through the opening of base plate 24 into the space 34 enclosed by enclosure 12.
The anchor means 32 is illustrated to comprise an auger 36 which can be screwed into the ground 26 so that the lower end 38 of the anchor means is firmly engaged in stable soil well below the surface of ground 26. It will be appreciated that the length of the anchor means 32 and its configuration are subject to variation and may depend on many variables including soil composition, wetness, etc.
A bracket means 40 is fixed to the interior of an intermediate portion 18 of enclosure 12. A biasing means 42 in the form of a spring is coupled to the eye 44 on the upper end 30 of the anchor 32. The spring 42 is also coupled to an adjustable coupling means 46 in the form of a threaded eye-bolt which penetrates the bracket means 40. A wing nut 48 permits adjustment of the tension in spring 42 so as to enhance the force applied by the spring to retain the post 10 in an upright position.
An additional bracket means 40 is provided at the upper end 14 of the enclosure. A mounting board 50 is situated across the upper end 14 of the enclosure, and coupling means in the form of stove bolts 52 are provided for coupling the mounting board 50 to bracket 40. It will be appreciated that the mounting board can be used as a supporting surface for a mailbox, a lamp, a sign, or other apparatus sought to be supported on a support in accordance with the present invention. It will further be appreciated that the mounting board can, in the appropriate circumstance, be integral with the apparatus mounted to the upper end 14 of the post 10.
In the preferred embodiment of the present invention, the materials for constructing a post as illustrated in FIG. 1 can be partially preassembled so as to be sold in kit form for a do-it-yourself construction using the minimum of tools. A pair of side assemblies 54 as shown in FIG. 2 are included in such a kit. Each side assembly 54 comprises two elongated corner defining members 20. The elongated defining members 20 include longitudinal slots 56. A rectangular panel member 22 is fixed with its longitudinal outer edges received in the confronting slots of the two corner members. The panel member 22 is preferably fixed in this position by nailing, bonding, or other equivalent means. Bracing means 58 are provided in the form of stretcher plates which are secured by fasteners 60 to a margin 62 inside slots 56 of corner members 20. The upper stretcher plate 64 is situated adjacent end 14 of the side assembly 54 while lower stretcher plate 66 is situated at an intermediate or mid portion 18 of the side assembly 54.
A connecting means 68 is provided for connecting the bracing means on one side assembly to the bracing means on the other side assembly. The connecting means 68 is shown in FIG. 3 to comprise bridging plate 70 and clips 72 which clip the bridging plate 70 to the stretcher plate 64. The bracing means 58 and connecting means 68 taken together form the bracket means 40 shown in FIG. 1.
The bridging plate 70 is shown in FIG. 3 to include a central round opening 74 and a pair of offset square openings 76. The bridging plate 70 also includes upstanding edges 78 which are separated from each other by corner notches 80. The stretcher plates 64 are shown to be received in a pair of corner notches 80 so that one of the upstanding edges 78 of the bridging plate 70 is positioned between the stretcher plate 64 and the adjacent panel member 22. The clip 72 clips upstanding edge 78 of the bridging plate 70 to stretcher plate 64.
The central round opening 74 in bridging plate 70 is used to receive the eye-bolt 46 as shown in FIG. 1. The square offset openings 76 are used to receive the bolts 52 as shown in FIG. 1. The bolts 52 are retained in position by retainers 82 in the form of nuts or clips which engage the bolts 52 and the upper surface of bridging plate 70.
To assemble a post in accordance with the present invention from a kit as previously described, the anchor means 32 is firmly installed in ground 26 at the desired location so that an upper end 30 protrudes slightly above the surface of ground 26. A base plate 24 is then situated on the ground so that the upper end 30 of anchor 32 protrudes through opening 28. The two side assemblies 54 are situated on base plate 24 such that the upper stretcher plates 64 are in a confronting relationship as are the lower stretcher plates 66. A bridging plate 70 is then inserted over the lower stretcher plates 66. The spring means 42 is coupled to eye 44 of the anchor upper end 30 and to the adjustable eye bolt 46. The upper end of the eye bolt 46 is passed through the central round opening 74 of the bridging plate 70 a distance sufficient to permit wing nut 48 to engage the threads of bolt 46. The wing nut 46 is then tightened so as to apply the desired pressure to the post 10. Another bridging plate 70 including the bolts 52 and retainers 82 is clipped to the upper stretcher plates so that the upper ends 84 of bolt 52 project beyond the upper end 14 of the side assemblies 54. A pair of side panels 86 are then slidably received downward from the top 14 in confronting slots 56 of the two adjacent side assemblies to complete the enclosure 12 except for an upward facing opening. The mounting board 50 is then positioned on the top 14 of the post so as to receive the upper ends 84 of bolts 52 which, together with fasteners such as nuts 88, act to secure the mounting board 50.
Once the post is so assembled, any lateral force on an upper portion of the post will cause the post to pivot about a lower edge 16 while the spring means 42 will act to ensure that the post will return to an upright position when the lateral force is removed. To change the side panels 86, the mounting board 50 is merely temporarily removed by disengaging fasteners 88 thereby permitting the side panels 86 to be slidably removed and replaced with other side panels. The mounting board 50 can then be reinstalled as before.
While the invention has been described in detail with reference to the illustrated preferred embodiment, variations and modifications exist within the scope and spirit of the invention as described. For example, the side assembly 54 is illustrated in FIG. 2 to comprise three separate elements, namely, the two corner members 20 and the intermediate panel member 22. These three members can be replaced by a unitary extruded plastic or aluminum member of the same general cross section and including slots 56. Appropriate bracing means 58 can be coupled to such an extruded member so as to form a side assembly substantially as shown. Additional variations and modifications within the scope and spirit of the invention as defined in the following claims will be apparent to those skilled in the art. | A post for supporting a mailbox or the like having an anchor engaging the ground and having an upper end, an enclosure having a plurality of vertical corner-defining members spaced from each other and including a vertical slot confronting the nearest adjacent corner-defining members and panel members situated between the corner-defining members, brackets fixed to at least some of the members of the enclosure within the intermediate portion for maintaining the relative position of the members, and a spring coupling a lower bracket to the anchor for biasing the lower ends of the vertical members toward the ground to support the enclosure in an upright position. | 4 |
[0001] This nonprovisional patent application claim priority to, and hereby incorporates herein by reference, U.S. Provisional Patent Application No. 62/263.309, filed 4 Dec. 2015, of the same title as shown above.
FIELD OF THE INVENTION
[0002] This invention relates to a specific substrate, for use in growing particularly engineered mushrooms, especially medicinal mushrooms.
BACKGROUND OF THE INVENTION
[0003] At this writing, states and commonwealths throughout the United States are debating and otherwise vetting (and in some cases approving) legislation concerning marijuana, generally his sativa. In lay discussions in the media and elsewhere, however, with widespread characterizations such as “medicinal marijuana” and “recreational marijuana,” there has been to date an under-emphasis on the important difference between tetrahydrocannabinol (THC) and cannabidiol (CBD), both as to psychogenic as, well as to medicinal effects. The present inventors believe this, will change rapidly, however, as more and more individuals begin to understand that CRD is a non-intoxicating cannabis compound that has important therapeutic properties, that can and should be administered either without accompanying THC for medicinal purposes or in a ratio with THC that is deliberately engineered. Even across all available cannabis strains at this writing, CBD usually accounts for at least 40% of an extract of Cannabis, and there are already known strains of cannabis that are very high in CBD content while also having little or no THC. Thoughtful practitioners of health and therapeutic supplementation therefore understand that the debate is not “marijuana or no marijuana?” but—what are the best sources of CBD and how is it best administered, in what dose or dosage range, in what if any ratio with THC, and−with which excipients?
[0004] In parallel to the importance of CBD (or carefully chosen CBD:THC ratios) for therapeutic purposes, medicinal mushrooms continue to play an important role in traditional Chinese herbalism, naturopathic medicine and nutritional therapies both in the United States and abroad. Mushrooms are considered to be one of the richest sources of natural antibiotics, with various species of fungi inhibiting the growth of a wide diversity of microorganisms (Vazirian, M. et al., “Antimicrobial effect of the Lingzhi or Reishi medicinal mushroom Ganoderma lucidum (higher Basidiomycetes) and its main compounds,” Int. J. Med. Mushrooms, 2014; 16(1): 77-84), Ganoderma lucidum , a well-known medicinal mushroom, has many pharmacological and biological activities including an antimicrobial effect. (Ibid.). The maitake mushroom ( Grifola frondosa ) contains grifolan, an important beta-glucan polysaccharide, that has been shown to activate macrophages, an important component of the immune system.
[0005] Laboratory studies have shown that maitake extract can block the growth of cancer tumors and boost the immune function of mice with cancer. It has also been found that shiitake mushrooms possess beneficial properties. A specific amino acid in shiitake helps speed up the processing of cholesterol in the liver. Shiitake also appears to be a formidable cancer fighter. A polysaccharide compound called lentinan has been isolated from shiitake, too, and in laboratory trials, lentinan appears to stimulate immune-system cells to clear the body of tumor cells. Shiitake appears to be effective against some of the more serious viruses, such as HIV and hepatitis B. Reishi mushrooms have been used in China and Japan for years as a medicine for liver disorders, hypertension, and arthritis, and researchers including Vazirian et al., above, have found that reishi has anti-allergic, anti-inflammatory, anti-viral, anti-bacterial, and antioxidant properties. In vitro experiments also indicate that reishi may help fight cancerous tumors.
[0006] Heretofore, to our knowledge, no one has made a sophisticated investigation into the conjunction of medicinal mushrooms and CBD.
[0007] In the commercial method of producing mushrooms, a suitably prepared substrate is impregnated with mushroom spores or previously collected mushroom mycelia. Under sterile lab conditions, the spores or mycelia are injected into the substrate, which has been prepared by soaking it in water and sterilizing it. Mycelia are the filamentous hyphen of a mushroom that collect water and nutrients to enable mushrooms to grow. The inoculated substrate is incubated to promote full colonization of the mycelia, at which point the mycelia-laced substrate is referred to as “spawn.” Spawning is usually done in a plurality of individual spawn growth vessels or “bags”. The substrate provides the nutrients necessary for mycelium growth. The mycelium-impregnated substrate is then allowed to develop under carefully controlled conditions of temperature and moisture, until the hyphen of the mycelium have permeated the substrate. This process usually takes anywhere from three to nine weeks for the mycelium to fully colonize the spawn bag. The spawn bag is allowed to continue to grow until the mycelium enriched product can be harvested between four to 10 weeks from the beginning of the process. Typically, mushroom growers purchase spawn or grow it themselves from agar plates, as will be known to one skilled in the art. In the commercial production of medicinal mushrooms, the spawn bag contains the final product, which is then sold or the contents processed into dry powdered product.
[0008] The idea of promoting enhanced uptake, as well as enhanced mycelium growth, by engineering improved substrates is disclosed, for example. In U.S. Pat. No. 7 , 178 , 285 , “Functional Substrates for Growth of Culinary and Medicinal Mushrooms.” In the context of U.S. Pat. No. 7 , 178 , 285 , one skilled in the art learned to maximize the uptake of desired constituents from the growth medium into the mycelium. U.S. Pat. No. 6 , 747 , 065 describes methods of producing mushroom mycelia rich in trace minerals by culturing the mycelia in a broth to which supplements have been added and, again, the emphasis is on maximizing uptake. However, it is possible that as to certain constituents of a medicinal mushroom, it can be as important to LIMIT uptake of certain desired medicinal compounds as it can be to enhance that uptake.
[0009] Accordingly, a need remains not only to converge the worlds of medicinal mushrooms and cannabis but to do do so in a way that controlled amounts of CBD and THC, in the desired ratio, appear in medicinal mushrooms grown in association with a reliable source of both compounds.
SUMMARY OF THE INVENTION
[0010] In order to meet this need, the present invention is a method of growing (preferably but not necessarily) Basiomycetes mushrooms on a substrate that includes unrefined, live or dried cannabis plants (whole or particulated), preferably those cannabis strains high in CBD and low in THC or containing a preferred ratio thereof, as part or all of the growth medium for the mushrooms. By titrating the type and amount of cannabis plant matter in the growth medium, desired uptake of CBD and THC is surprisingly accomplished in engineerable amounts and ratios. Using the whole or minimally particularized live cannabis plant gives new and unexpected results, in the mushroom substrate, in contrast to including cannabis extracts or other purified or semi-purified cannabis products in the growth medium. It is believed, although the inventors do not intend, to be bound by the following theory, that not only are the THC and CBD more accessible for controlled uptake, coming from a fresh (including responsibly dried) Cannabis constituent in the growth medium, but that also the fresh Cannabis plants themselves provide a surprisingly good substrate base for robust mushroom mycelia growth irrespective of their CBD and THC constituents. The resulting combination of mushroom mycelia and cannabis is believed to enhance the absorption of key constituents within the cannabis as well as infuse the cannabis based substrate with extracellular fungal compounds including but not limited to polysaccharide such as beta glucans, glycoproteins, polysaccharide peptides, proteoglycans, triterpenes, ergosterols and ergothionine.
DETAILED DESCRIPTION OF THE INVENTION
[0011] As used herein the tern “mushroom biomass” refers to mushroom mycelia, fruiting mbodies, spawn, or other life cycle stage of a mushroom, alone or in combination with each other or in combination with the substrate on which the mushroom is grown, including the functional substrates described herein. “Medicinal mushroom” refers to the varieties of mushrooms grown for their desired medicinal properties compounds, as is known in the art.
[0012] As an optional addition to the cannabis plants that make up the present growth substrate, other traditional substrate materials may be admixed with the cannabis plants as desired. Particularly suitable substrates for growing mushrooms include grains having high levels of anthocyanins, as noted by the color of the grain. By way of example, certain varieties of corn such as purple corn and black corn have high levels of anthocyanins. Purple barley and purple or black rice varieties are also known to contain high levels of anthocyanins. However, any other suitable mushroom growth substrate may be mixed with the cannabis plants or plant parts as desired, in the practice of the invention.
[0013] Any variety of mushroom will, benefit from the methods of the present invention, although due to the intended end use of the mushrooms the variety must be edible by humans. Suitable varieties include, but are not limited to, Trametrs versicolor Ganoderma lucidum, Hericium erinaceus, Lentinula edodes, Schizophylium commune, Pleuratus ostreatus, Agaricus blazei, Lentinula edodes, Flammulina velutipes, Grifola frondonsus, and Ohiocordyceps species. Preferably the mushrooms will derive from the family Basiomycetes.
[0014] The substrate is prepared for each individual spawn bag. The spawn bags are designed with a high efficiency particulate air (HEPA) filter and can be autoclave heat sterilized. The HEPA filter on the spawn bag allows the bag to breathe and protects the substrate from contamination. Each spawn bag contains 2-5 pounds of prepared substrate consisting of a batch mix of about 3 pounds whole live cannabis plants or particulated fresh cannabis plants with about 2 pounds water. (Alternatively, grains in the desired amount may be admixed with the cannabis plants in the desired ratio.) The unsealed spawn bags are then pasteurized or autoclave steam sterilized up to a temperature of about 250 degrees F. (at approximately 15 psig) for a period between 45 minutes to eight hours—enough to pasteurize or sterilize the substrate as to microorganisms but not enough to denature the cannabis plants as to their essential structure or components. The cook time is the time that steam is supplied and shutdown to the autoclave. HEPA-filtered clean air is then applied for rapid cool down of the autoclave. The cooking time is determined by monitoring the inner core temperatures of the spawn substrate. Following steam pasteurization or autoclaving to sterilize the substrate, the spawn bags are then inoculated with spawn. The spawn bags are then heat sealed and the bags gently tumbled by hand or machine to evenly distribute the spawn throughout the substrate. Thorough mixing may take a few seconds to a minute. Clean room conditions must be maintained during the process to prevent contamination of the substrate. The spawn bags are allowed to spawn run and mature for a period of about 21-90 days, alter which time the mycelium-enriched spawn bags are harvested. The live (fresh) product can be sold by individual spawn bags without opening (or harvesting) the bags.
[0015] If a dry product is, desired, the spawn bags are opened and the live product contents are spread out on dryer trays. The product is evenly distributed across the dryer tray with less than about 1″ height. The dryer trays are loaded into a dehydration unit including but not limited to freeze drying, air drying, Vacuum dehydration or convection drying. The air temperature of the dryer may be adjusted from ambient room temperature to about 190 degrees F. Usually the air temperatures are set to between 115 to 180 degrees F. and drying, times are automatically set from 16-24 hours. The air temperatures can be set lower, requiring longer dry times. The final dried product is tested to have a less than or equal to about 6% by weight moisture content Each spawn bag initially weighing 5 pounds (water and grain mix) is designed to produce slightly greater than 1 kg of dry product
[0016] The dry product is powdered using a grinder with 40 mesh or finer screen. The powder is then bottled or encapsulated directly or formulated into blends and then bottled of encapsulated. The thy product may also be mixed with other ingredients to be used in foods, functional foods, beverages or cosmetics.
[0017] Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims. Therefore, although the invention has been described with respect to particular methods and constituents, above, the scope of the invention is only to be limited insofar as is set forth in the accompanying claims. | The present invention is a method of wowing mushrooms, preferably but not necessarily) Basiomycetes mushrooms, on a substrate that includes unrefined, live or dried cannabis plants (whole or particulated) preferably those cannabis, strains high in CBD and low in THC or containing a preferred ratio thereof, as part or all of the growth medium for the mushrooms. | 2 |
BACKGROUND TO THE INVENTION
The present invention relates to a process for the production of chromium-based catalysts for the production of polyethylene and to the use of such catalysts.
DESCRIPTION OF THE PRIOR ART
Polyethylene is well known for use in the manufacture of various articles. It is generally desirable for the polyethylene resin to have good processing properties whereby the polyethylene melt may readily be processed to form the appropriate article. In order to achieve such good processability of the polyethylene resins, it is desired that the flow properties and the shear response (SR) of the polyethylene are improved by broadening the molecular weight distribution of the polyethylene. A number of different catalyst systems have been disclosed for the manufacture of polyethylene, in particular high density polyethylene HDPE. It is known in the art that the physical properties, in particular the mechanical properties, of a polyethylene product vary depending on what catalytic system was employed to make the polyethylene. This is because different catalyst systems tend to yield different molecular weight distributions in the polyethylene produced. It is known to employ a chromium-based catalyst i.e. a catalyst known in the art as a "Phillips catalyst". Such a chromium-based catalyst enables the production of polyethylene having desirable physical and rheological properties.
There is a continuous incentive to develop new chromium-based Phillips catalysts for the production of polyethylene resins having improved mechanical or processing properties. Technical developments in the art have permitted a reduced consumption of polymer for the manufacture of individual final parts or products, for example the use of thinner walls for plastics bottles.
A large number of chromium-based catalysts are available for the production of HDPE, and also medium density polyethylene (MDPE) , resins. For example, such catalysts include chromium deposited on various supports such as silica, silica-titania cogels, tergels, amorphous aluminium phosphate, alumina, Si--Al--P oxides, and silica-alumina supports such as cogels, coated silica or coprecipitated Cr--Al/silica supports.
EP-A-0072077 discloses the production of a chromium-based catalyst having a silica-alumina support. That specification discloses the deposition of a "Cr--Al complex" onto a silica carrier. The complex is obtained by reacting a Cr (III) compound, typically chromium acetylacetonate, with a trialkyl aluminium compound, typically triisobutyl aluminium (TIBAL), in an inert organic solvent and then impregnating a dry silica carrier with that complex.
Such a catalyst produced by that known process suffers from the disadvantage that shear response of the resultant polyethylenes produced using the catalyst in the polymerisation process could yet be improved. In addition, the catalyst produced in accordance with that prior specification does not have a particularly high activity with respect to the polymerisation of polyethylene.
SUMMARY OF THE INVENTION
It is an aim of the present invention to provide a process for producing a catalyst for use in the polymerisation of ethylene having improved rheological, and preferably also mechanical, properties. It is a further aim of the present invention to provide such a catalyst which has a good activity and also a good hydrogen response.
Accordingly, the present invention provides a process for producing a chromium-based catalyst for the production of polyethylene, the process comprising the steps of providing a catalyst support selected from silica, silica-titania and silica-zirconia; reacting the support with one of an aluminium alkyl compound or a chromium salt compound selected from at least one of chromium (III) acetylacetonate, chromium (III) acetate, chromium (III) oxalate and chromium (III) stearate; and thereafter reacting the support with the other of the aluminium alkyl compound or the chromium salt to produce a chromium-impregnated catalyst having a silica-alumina support, the catalyst composition comprising from 0.4 to 1.5 wt % chromium, based on the weight of the chromium-based catalyst and the alumina in the silica-containing support comprising from 0.5 to 4 wt % aluminium in the chromium-based catalyst.
In one embodiment of the process of the invention, the support is initially treated with the aluminium alkyl compound to form an alumina-containing silica support and thereafter the alumina-containing support is impregnated with chromium by treatment with the chromium salt.
In a second embodiment of the invention the support is treated with the chromium salt to impregnate chromium on the support and thereafter the chromium-impregnated support is treated with the aluminium alkyl compound thereby to incorporate alumina into the support.
The aluminium alkyl compound preferably comprises at least one of triisobutyl aluminium (TIBAL), triethyl aluminium (TEAL), tri-n-hexyl aluminum (TNHAL), tri-n-octyl aluminium (TNOAL) or methyl aluminium oxane (MAO). The aluminium alkyl compound is preferably deposited onto the support in the liquid phase and is present in an organic solvent.
Preferably, the support has a high surface area, typically greater than 400 m 2 /g, and a high pore volume, typically at least 1.5 cc/g.
The present invention also provides the use of the catalysts produced in accordance with the invention for increasing the shear response of polyethylene resins.
The present invention is predicated on the surprising discovery by the inventors that by subjecting a silica-containing carrier with consecutive treatments, in either order, of (a) depositing alumina on the carrier and (b) impregnating the carrier with chromium, this can provide a catalyst yielding polyethylene resins having improved processability, as represented by the shear response (SR). The shear response of the polyethylene resins can be improved as compared to the known process for producing a chromium-based catalyst having a silica-alumina support as disclosed in EP-A-0072077. The increased shear response in the resultant polyethylene resins can, for any given melt index, yield improved processability of the resins and also improved mechanical properties.
Furthermore, the use of catalysts produced in accordance with the invention can provide that the polyethylene polymerisation process has an improved, i.e. higher, hydrogen response. In other words, the melt index, for example the melt index MI 2 , of the polyethylene resins can readily be increased by increasing the hydrogen amount present in the polymerisation reactor.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described in detail with reference to the following non-limiting Examples and with reference to the accompanying drawings, in which:
FIG. 1 is a graph showing the relationship between the shear response and the melt index of resins produced in accordance with Examples 1 to 4 of the present invention and in accordance with Comparative Examples 1 and 2; and
FIG. 2 is a further graph showing the relationship between the shear response and the melt index of polyethylene resins produced in accordance with Examples 5 and 6 of the present invention and in accordance with Comparative Example 3 wherein each catalyst was subjected to a titanation treatment prior to activation thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLE 1
In this Example, a silica carrier for the resultant chromium-based catalyst was initially treated so as to deposit alumina thereon and thereafter the aluminated carrier was impregnated with chromium.
In the alumination step 120 g of silica were dried under nitrogen for 4 hours at 200° C. in a fluidised bed. The silica employed was a commercially available silica sold in commerce by the company Grace GmbH of Worms, Germany under Grade G5H. Thereafter, 100 g of the dried silica were introduced into a two liter glass reactor under a dry nitrogen blanket. The reactor was provided with a double jacket to allow cooling/heating thereof with water or oil. Then 850 ml of dry de-aerated hexane were poured into the reactor to form a silica slurry. Thereafter 30.29 g of a solution of triisobutyl aluminium (TIBAL) in a 50 wt % solution in hexane were added drop by drop, at room temperature, under stirring. The stirring was maintained for a period of 1 hour following complete TIBAL addition. The slurry was then allowed to settle for 30 minutes. The solution was then sucked off from the reactor using nitrogen gas overpressure and the residual solvent was removed by heating the reactor under vacuum. The reactor was then allowed to cool. All the operations up to this point were carried out under a nitrogen blanket to avoid any contact with air or moisture. The dried carrier was then treated with air and air injection was employed to avoid any temperature rise of the carrier above a temperature of around 100° C. The stabilised alumina-silica carrier had a yellow vanilla colour.
Following the alumination step, 100 g of the aluminated carrier were introduced into a 1000 ml bottle and the bottle and the silica-alumina carrier were subjected to a vacuum for 30 minutes. Then, 7 g of chromium (III) acetylacetonate (Cr(acac) 3 ) (97 wt % purity) were added to 400 ml of acetone. The thus-formed chromium-containing solution was added to the silica-alumina carrier drop by drop and then the bottle was shaken overnight. The acetone was then evaporated off in a rotavapour machine at a temperature of around 72° C. under a vacuum pressure of 400 mbars until a dry powder was obtained. The resultant catalyst was dried in an oven at a temperature of around 80° C. for one night. The final chromium-based catalyst had a blue colour.
EXAMPLE 2
In Example 2 a chromium-based catalyst having a support containing silica and alumina was produced by a process in which a silica carrier was initially subjected to a chromium-impregnation step following which the chromium-impregnated support was subjected to an alumination step, i.e. with a different order of steps of the chromium-impregnation and alumination than in Example 1.
In this Example, chromium is first deposited onto a silica support by impregnation by either an aqueous or an organic solution of a chromium compound followed by drying. The chromium compound comprised chromium (III) acetate. The support comprised a silica catalyst sold in commerce under the trade name HA30 by the company Grace GmbH of Worms, Germany. The resultant chromium-impregnated support contained 1 wt % Cr based on the weight of the chromium-impregnated support.
Thereafter, 120 g of the chromium-impregnated support were dried in a fluidised bed a temperature of 200° C. under nitrogen flow for 4 hours. Then 100 g of the dried catalyst were placed in a double-jacketed glass reactor under dry nitrogen and 800 ml of dried de-aerated hexane were introduced to form a slurry. Then 30.29 g of a 50 wt % solution of TIBAL in hexane were added drop by drop into the reactor at room temperature and under mechanical stirring. Stirring was carried on for a period of 1 hour after completion of the TIBAL addition. Stirring was then stopped and the mixture was allowed to settle for 30 minutes. The clear liquid solution was then sucked from the reactor and the residual solvent was then removed by heating the reactor under vacuum. The dried catalyst was then carefully stabilised by introducing air into the reactor. The air flow was established so as to avoid any temperature rise above 100° C. The final chromium-based catalyst containing a silica-alumina support was green in colour.
EXAMPLES 3 & 4
The catalysts produced in accordance with Examples 1 and 2 were evaluated for their performance in ethylene polymerisation to form polyethylene resins in bench scale polymerisation processes. Prior to use, the catalysts of Examples 1 and 2 were activated at a temperature of 650° C. in air and in a fluidised bed. The activity of each catalyst was controlled so as to have a productivity of around 1000 g PE/g catalyst.
The bench scale reactors had a volume of 4 liters. The required amount of activated catalyst was introduced into the reactor and then 21 of isobutane as a diluent were introduced into the reactor vessel. The reactor vessel was then heated to a polymerisation temperature of from 96 to 106° C. and an ethylene pressure was established so as to introduce around 6 wt % ethylene dissolved in isobutane into the polymerisation reactor. 1-hexene was injected into the system to provide a hexene concentration of from 0 wt % to around 0.5 wt % in isobutane.
The 1-hexene concentration and temperature were varied between different runs in the same Examples to provide polyethylenes of varying melt index MI 2 . The melt index MI 2 is determined using the procedures of ASTM D1238 having a load of 2.16 kg at a temperature of 190° C. For each polyethylene resin, the high load melt index (HLMI) was also determined using the procedures of ASTM D1238 using a load of 21.6 kg at a temperature of 190° C. The shear response, which is a ratio between the HLMI and MI 2 values and is representative of the processability of the polyethylene resins, was then calculated.
FIG. 1 shows the relationship between the shear response SR and the melt index MI 2 , for the polyethylene resins produced in accordance with Examples 3 and 4. Each Example comprised two or three runs producing polyethylene resins of different melt index by changing the polymerisation temperature and/or the 1-hexene concentration in the polymerisation reactor vessel. It may be seen from FIG. 1 that for any given value of the melt index MI 2 , the resins produced in accordance with Example 3, using the catalyst produced in accordance with Example 1, tend to have a higher shear response SR than the resins produced in accordance with Example 4, using the catalyst of Example 2. This indicates that the resins produced in accordance with Example 3 tend to have an improved processability as compared to the resins produced in accordance with Example 4.
COMPARATIVE EXAMPLE 1
In accordance with Comparative Example 1 a chromium-based catalyst having a silica-alumina support was produced in accordance with the prior art method generally disclosed in EP-A-0072077. In that process, a "Cr--Al complex" was prepared which was then impregnated onto a silica carrier, as opposed to the successive chromium-impregnation/alumination or alumination/chromium-impregnation steps employed in accordance with the methods of the embodiments of the present invention.
In Comparative Example 1, a "Cr--Al complex" of chromium (III) acetylacetonate and triisobutyl aluminium (TIBAL) was synthesised, with the synthesis steps being carried out under a nitrogen blanket to avoid any contact with moisture or air. Initially, 7.13 g of chromium (III) acetylacetonate (Cr(acac) 3 ) (97 wt % purity) were added into 100 ml of dry de-aerated hexane to form a slurry mixture in a double-jacketed reactor. The mixture was then heated under stirring until the boiling point of the mixture and then the mixture was refluxed at a temperature of around 70 to 80° C. in the double-jacketed reactor. After reflux, 30.29 g of TIBAL as a 50% a solution comprising 15.145 g of pure TIBAL and 15.145 g of dried de-aerated hexane were added drop by drop to the refluxed mixture containing chromium (III) acetylacetonate. An exothermal reaction then occurred and the system was refluxed for a further period of 1 hour. A solution of a dark brown complex was obtained. The solution was transferred, under nitrogen gas, into a 250 ml glass bottle and the mixture was then filtered under nitrogen to remove any insoluble compound. The resultant solution was kept under nitrogen.
In the following silica-impregnation step, 120 g of silica available in commerce from the company Grace GmbH of Worms, Germany under Grade G5H were dried in a fluidised bed under a flow of nitrogen for a period of 4 hours at a temperature of around 200° C. Then, 100 g of the dried silica were introduced into a 21 reactor under nitrogen and 850 ml of hexane were added to form a slurry. The previously formed complex of Cr(acac) 3 -TIBAL was added drop by drop, at room temperature, under mechanical stirring and the stirring was continued for a period of 1 hour after the complete addition of the complex. The hexane solution became clear whereas the silica turned dark brown.
The catalyst was then dried and stabilised by the following steps. Stirring was interrupted and the mixture was allowed to settle for a period of 30 minutes. The clear solution was transferred to another glass flask using nitrogen overpressure and the remaining solvent was evaporated by heating at a temperature of around 70° C. under vacuum in a vacuum flask. Any gas admitted into the system comprised nitrogen gas. The dried catalyst was stabilised by admitting a small flow of dry air into the reactor and the air flow was adjusted so as to keep the temperature below 100° C.
The thus-obtained unactivated catalyst had a green colour. The target composition of the catalyst was 1 wt % Cr and 2 wt % Al, each based on the weight of the chromium-based catalyst.
COMPARATIVE EXAMPLE 2
The catalyst formed in accordance with Comparative Example 1 was employed in a bench scale polymerisation process similar to the process described with reference to Examples 3 and 4. The polymerisation conditions, in particular the 1-hexene concentration and polymerisation temperature, were varied to yield polyethylene resins having differing melt indexes MI 2 in five runs. For each polyethylene resin so produced, the melt index MI 2 and the shear response SR were determined. The results are also shown in FIG. 1.
It may be seen that for Comparative Example 2, for any given melt index MI 2 the shear response SR significantly lower for the resins produced thereby as compared to the resins produced in accordance with Examples 3 and 4. This demonstrates that the catalysts prepared in accordance with the invention using consecutive chromium-impregnation/alumination steps in either order can yield polyethylene resins having improved shear response as compared to the resins produced using the catalyst known from EP-A-0072077. The resultant polyethylene resins formed in accordance with the present invention thus exhibit improved processability and also mechanical properties, as compared to the resins produced using the known catalyst.
The catalysts produced in accordance with the invention also have been found to exhibit a higher activity as compared to the catalyst produced in accordance with Comparative Example 1. If the catalyst produced in accordance with Comparative Example 1 is determined to have a relative activity of 100, the catalysts produced in accordance with the Examples 1 and 2 have relative activities of 120 and 150 respectively.
EXAMPLES 5 & 6
Examples 3 and 4 were repeated with the additional step, prior to the catalyst activation step, of titanating the catalysts of Examples 3 and 4 with titanium triisopropoxide at a temperature of around 300° C. to yield a target titanium content of around 4 wt % based on the weight of the catalyst.
Again, the resultant resins for each Example having varying melt index MI 2 were tested so as to measure the melt index and to determine the shear response for each resin. The results are shown in FIG. 2. Four runs were performed for each Example.
FIG. 2 shows that for Examples 5 and 6, the shear response/melt index relationship is such that for Example 5 the shear response is generally higher for any given value of MI 2 as compared to the resins produced in accordance with Example 6.
COMPARATIVE EXAMPLE 3
In Comparative Example 3 the catalyst produced in accordance with Comparative Example 1 was subjected to the bench scale polymerisation process described with reference to Comparative Example 2 but additionally employing a titanation step as described with reference to Examples 5 and 6 prior to activation of the catalyst. The polyethylene resins produced in accordance with Comparative Example 3 had varying melt index MI 2 and again the relationship between the shear response and the melt index is shown in FIG. 2. Five runs were performed for Comparative Example 3.
It may be seen from FIG. 2 that for any given melt index MI 2 value for the polyethylene resins produced in Comparative Example 3, the shear response is significantly lower than for the resins produced in accordance with Examples 5 and 6 having similar melt indexes MI 2 . This demonstrates that the use in a polyethylene polymerisation process of the catalysts produced in accordance with the present invention can provide resins having improved processability as represented by the shear response, particularly when the alumination of the catalyst is carried out prior to the chromium-impregnation. Furthermore, it was found that the activity of the catalyst produced in accordance with Examples 5 and 6 was around 30 to 70% higher than the catalyst produced in accordance with Comparative Example 3.
EXAMPLES 7 & 8
The polymerisation processes of Examples 3 and 4 were repeated but instead of introducing hexene as a copolymer into the polymerisation reactor, polyethylene homopolymers were produced and up to 10 Nl of hydrogen gas were introduced into the reactor. The polymerisation conditions for various runs, including the polymerisation temperature and the amount of hydrogen, are shown in Table 1, for Examples 7 and 8, together with the measured values for the melt index MI 2 and the shear response SR for the resultant polyethylene resins.
TABLE 1______________________________________ Polymerisation Temperature H.sub.2 MI.sub.2 (0° C.) (Nl) (g/10 min) SR______________________________________Example 7 102 0 0.039 141 106 0 0.173 106 102 10 0.30 76Example 8 104 0 0.082 101 106 0 0.16 96 102 10 0.17 82Comparative 102 0 0.059 110Example 4 104 0 0.088 93 102 10 0.13 88 104 10 0.17 78______________________________________
The hydrogen response of a catalyst for polymerising polyethylene represents the ability of hydrogen gas to increase the melt index, for example the melt index MI 2 , of the resultant polyethylene resin at any given polymerisation temperature for a given concentration of hydrogen in the polymerisation process. As a general rule, as the amount of hydrogen employed in the polymerisation reactor increases, the melt index MI 2 of the subsequent polyethylene resin tends to increase, for any given polymerisation temperature. It may be seen from Table 1 that for Example 7, the melt index of the resultant polyethylene resin produced using a hydrogen introduction and at a polymerisation temperature of 102° C. is higher than the corresponding melt index of Example 8 also having a similar hydrogen introduction and polymerisation temperature. Thus the catalyst produced in accordance with Example 7 has a higher hydrogen response than that produced in accordance with Example 8.
When comparing Examples 7 and 8 it may be seen that for a given melt index and polymerisation temperature the polyethylene resins produced in accordance with Example 7 tend to have a higher shear response SR than those of Example 8. This is an indication that the use of a catalyst having an alumination treatment by TIBAL with subsequent chromium-impregnation, produces resins having improved processability as compared to resins polymerised using a catalyst which was prepared using a consecutive treatment of chromium-impregnation and then alumination by TIBAL.
COMPARATIVE EXAMPLE 4
Comparative Example 4 repeated the experiments of Examples 7 and 8 by using as the catalyst the catalyst produced in accordance with Comparative Example 1. The polymerisation conditions of various runs of Comparative Example 4, together with the properties of the resultant polyethylene resins, are also shown in Table 1.
It may be seen from Table 1 that for any given polymerisation temperature, in the absence of hydrogen the shear response obtained using the catalysts of the invention is higher than for the catalyst of the prior art as represented by Comparative Example 4. This shows that the catalysts of the present invention can provide polyethylene resins having improved processability. In addition, for the run having a polymerisation temperature of 102° C. and a hydrogen addition of 10 Nl, the melt index MI 2 of Comparative Example 4 is lower than the corresponding values for Examples 7 and 8. This indicates that the hydrogen response for catalysts produced in accordance with the invention is higher than that for the known catalyst.
In summary, the use of the catalysts produced in accordance with the invention can enable the production of polyethylene resins having higher shear response, and thus improved processability, and mechanical properties, compared to polyethylene resins produced using known catalysts prepared by the impregnation of a "Cr--Al complex" onto a silica-containing support. In addition, the catalysts of the present invention can enable a higher hydrogen response to be achieved, together with higher catalyst activity The use of a titanation treatment in the activation procedure also yields higher shear response for the resultant polyethylene resins and higher catalytic activity than for the known catalyst. | A process for producing a chromium-based catalyst for the production of polyethylene, the process comprising the steps of providing a catalyst support selected from silica, silica-titania and silica-zirconia; reacting the support with one of an aluminium alkyl compound or a chromium salt compound selected from at least one of chromium (III) acetylacetonate, chromium (III) acetate, chromium (III) oxalate and chromium (III) stearate; and thereafter reacting the support with the other of the aluminium alkyl compound or the chromium salt to produce a chromium-impregnated catalyst having a silica-alumina support, the catalyst composition comprising from 0.4 to 1.5 wt % chromium, based on the weight of the chromium-based catalyst and the alumina in the silica-containing support comprising from 0.5 to 4 wt % aluminium in the chromium-based catalyst. | 8 |
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/207,008, filed Jul. 30, 2002, now U.S. Pat. No. 7,684,422 which claims priority under 35 U.S.C. §119 based on U.S. Provisional Application No. 60/348,651, filed Jan. 17, 2002, the disclosures of which are incorporated herein by reference. This application is also related to U.S. patent application Ser. No. 10/207,006 , entitled “DEQUEUING AND CONGESTION CONTROL SYSTEMS AND METHODS” filed filed Jul. 30, 2002, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to congestion control during data transfer and, more particularly, to systems and methods for performing efficient random early drops at the head of a packet buffer.
2. Description of Related Art
Conventional network devices, such as routers, relay streams of data through a network from a source to a destination. Typically, the network devices include one or more memory subsystems to temporarily buffer data while the network devices perform network-related functions, such as route processing or accounting.
A data stream may be considered a pipe of data packets belonging to a communication between a particular source and one or more particular destinations. A network device may assign a variable number of queues (e.g., where a queue may be considered a logical first-in, first-out (FIFO) buffer) to a data stream. For a stream with n queues, the relationship of queues and streams may be represented by:
stream
bandwidth
=
∑
0
n
-
1
queue
bandwidth
.
A problem that may arise in the use of queues is that congestion occurs if data builds up too quickly in the queues (i.e., data is enqueued at a faster rate than it is dequeued). Network devices typically address this problem by notifying sources of the packets of the congestion. This notification sometimes takes the form of dropping more recent packets received from the sources.
Conventional congestion avoidance techniques are replete with problems, however. For example, determining which sources to notify of the congestion can be difficult. Global synchronization can result if all sources are notified to reduce their output at the same time. Another problem involves determining when to notify the sources of the congestion. Delayed notifications can lead to reduced throughput.
As a result, there is a need for systems and methods for efficiently processing and buffering packets in a network device.
SUMMARY OF THE INVENTION
Systems and method consistent with the principles of present invention address this and other needs by providing packet drops at the head of a packet buffer to, thereby, signal congestion earlier to traffic sources and provide tighter latency controls. The systems and methods also separate packet dropping from packet dequeuing to increase efficiency throughput and maintain correctness of the underlying processes.
In accordance with the principles of the invention as embodied and broadly described herein, a system selectively drops data from a queue. The system includes queues that temporarily store data, a dequeue engine that dequeues data from the queues, and a drop engine that operates independently from the dequeue engine. The drop engine selects one of the queues to examine, determines whether to drop data from a head of the examined queue, and marks the data based on a result of the determination.
In another implementation consistent with the principles of the invention, a network device includes multiple groups of queues, multiple dequeue engines corresponding to the queue groups, and multiple drop engines independent from the dequeue engines and corresponding to the queue groups. Each of the queue groups corresponds to one of a group of data streams. Each of the dequeue engines is configured to dequeue data from queues in the corresponding queue group. Each of the drop engines is configured to identify one of the queues to examine in the corresponding queue group, determine a drop probability for data at a head of the examined queue, and determine whether to drop the data from the head of the examined queue based on the drop probability.
In yet another implementation consistent with the principles of the invention, a method for efficiently dropping data from one of a group of queues includes storing first values that correspond to the queues, each of the first values identifying an amount of memory made available to the queue; storing second values that correspond to the queues, each of the second values identifying an amount of memory used by the queue; storing third values that correspond to the queues, each of the third values controlling a rate at which the queue will be examined; identifying one of the queues to examine based on the third values; and determining whether to drop data at a head of the identified queue based on the first and second values corresponding to the identified queue.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, explain the invention. In the drawings,
FIG. 1 is a diagram of an exemplary network device in which systems and methods consistent with the principles of the invention may be implemented;
FIG. 2 is an exemplary diagram of a packet forwarding engine (PFE) of FIG. 1 according to an implementation consistent with the principles of the invention;
FIG. 3 is an exemplary diagram of a portion of the memory of FIG. 2 according to an implementation consistent with the principles of the invention;
FIG. 4 is an exemplary diagram of a portion of the packet information memory of FIG. 3 according to an implementation consistent with the principles of the invention;
FIG. 5 is an exemplary diagram of the queue control engine of FIG. 4 according to an implementation consistent with the principles of the invention;
FIG. 6 is an exemplary diagram of the oversubscription engine of FIG. 5 according to an implementation consistent with the principles of the invention;
FIG. 7 is an exemplary time line that facilitates measurement of bandwidth use according to an implementation consistent with the principles of the invention;
FIG. 8 is a flowchart of exemplary oversubscription processing according to an implementation consistent with the principles of the invention;
FIGS. 9A-9C are exemplary diagrams that illustrate oversubscription according to an implementation consistent with the principles of the invention;
FIG. 10 is an exemplary diagram of the drop engine of FIG. 5 according to an implementation consistent with the principles of the invention;
FIG. 11 is an exemplary graph of a drop profile consistent with the principles of the invention;
FIG. 12 is an exemplary diagram of the drop decision logic of FIG. 10 according to an implementation consistent with the principles of the invention;
FIG. 13 is a flowchart of exemplary processing by the drop engine of FIG. 10 according to an implementation consistent with the principles of the invention; and
FIG. 14 is an exemplary diagram of queue selection using HIVec and LOVec vectors according to an implementation consistent with the principles of the invention.
DETAILED DESCRIPTION
The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims and equivalents of the recited claim limitations.
Systems and methods consistent with the principles of the invention efficiently drop packets by separating dequeuing and dropping mechanisms to permit these mechanisms to operate in parallel, possibly on the same queue. The systems and methods provide random early drop (RED) at the head of a packet buffer, thereby signaling congestion earlier to traffic sources and providing tighter control of latency by dropping according to a probability that increases as the latency through the packet buffer increases.
Exemplary Network Device Configuration
FIG. 1 is a diagram of an exemplary network device in which systems and methods consistent with the principles of the invention may be implemented. In this particular implementation, the network device takes the form of a router 100 . Router 100 may receive one or more packet streams from a physical link, process the stream(s) to determine destination information, and transmit the stream(s) on one or more links in accordance with the destination information.
Router 100 may include a routing engine (RE) 110 and multiple packet forwarding engines (PFEs) 120 interconnected via a switch fabric 130 . Switch fabric 130 may include one or more switching planes to facilitate communication between two or more of PFEs 120 . In an implementation consistent with the principles of the invention, each of the switching planes includes a three-stage switch of crossbar elements.
RE 110 performs high level management functions for router 100 . For example, RE 110 communicates with other networks and systems connected to router 100 to exchange information regarding network topology. RE 110 creates routing tables based on network topology information, creates forwarding tables based on the routing tables, and sends the forwarding tables to PFEs 120 . PFEs 120 use the forwarding tables to perform route lookup for incoming packets. RE 110 also performs other general control and monitoring functions for router 100 .
Each of PFEs 120 connects to RE 110 and switch fabric 130 . PFEs 120 receive packets on physical links connected to a network, such as a wide area network (WAN), a local area network (LAN), etc. Each physical link could be one of many types of transport media, such as optical fiber or Ethernet cable. The packets on the physical link are formatted according to one of several protocols, such as the synchronous optical network (SONET) standard or Ethernet.
FIG. 2 is an exemplary diagram of a PFE 120 according to an implementation consistent with the principles of the invention. PFE 120 may include two packet processors 210 and 220 , each connected to a memory system 230 and RE 110 . Packet processors 210 and 220 communicate with RE 110 to exchange routing-related information. For example, packet processors 210 and 220 may receive forwarding tables from RE 110 , and RE 110 may receive routing information from packet processor 210 that is received over the physical link. RE 110 may also send routing-related information to packet processor 210 for transmission over the physical link.
Packet processor 210 connects to one or more physical links. Packet processor 210 may process packets received from the incoming physical links and prepare packets for transmission on the outgoing physical links. For example, packet processor 210 may perform route lookup based on packet header information to determine destination information for the packets. For packets received from the links, packet processor 210 may store data in memory system 230 . For packets to be transmitted on the links, packet processor 210 may read data from memory system 230 .
Packet processor 220 connects to switch fabric 130 . Packet processor 220 may process packets received from switch fabric 130 and prepare packets for transmission to switch fabric 130 . For packets received from switch fabric 130 , packet processor 220 may store data in memory system 230 . For packets to be transmitted to switch fabric 130 , packet processor 220 may read data from memory system 230 .
Packet processors 210 and 220 may store packet data and other packet information, such as control and/or address information, within separate portions of memory system 230 . FIG. 3 is an exemplary diagram of a portion of memory system 230 according to an implementation consistent with the principles of the invention. In FIG. 3 , memory system 230 includes a data memory system 310 and a packet information memory system 320 . Data memory system 310 may store the data from a packet, possibly in non-contiguous locations. Packet information memory system 320 may store the corresponding packet information in queues based on, for example, the packet stream to which the packet information corresponds. Other information, such as destination information and type of service (TOS) parameters for the packet, may be used in determining the particular queue(s) in which to store the packet information.
FIG. 4 is an exemplary diagram of a portion of packet information memory system 320 according to an implementation consistent with the principles of the invention. In FIG. 4 , packet information memory system 320 includes queues 410 , dequeue engine 420 , and queue control engine 430 . In addition, memory system 320 may include an enqueue engine (not shown) that stores data in queues 410 .
Packet information memory system 320 may concurrently store packet information corresponding to multiple, independent packet streams. In an implementation consistent with the principles of the invention, memory system 320 may contain separate queues 410 , dequeue engines 420 , and queue control engines 430 corresponding to each of the packet streams. In other implementations, dequeue engine 420 and queue control engine 430 may correspond to multiple streams.
Queues 410 may include a group of first-in, first-out (FIFO) buffers that corresponds to a single stream. Other queues (not shown) may be provided for other packet streams. Queues 410 share the bandwidth of a single packet stream. In one implementation, each of queues 410 is allocated a static amount of packet information memory system 320 at configuration time. The amount of packet information memory system 320 allocated to a particular queue may be determined based on factors, such as the round trip time (Rtt), delay, and bandwidth associated with the stream, that minimize the chance that the queue will overflow.
Each of queues 410 may have three parameters associated with it: a weight between 0 and 1, a priority PR parameter that is either HI or LO, and a rate-control RC parameter that is either ON or OFF. A queue's weight determines the fraction of the stream's bandwidth B that is statically allocated to the queue. For a queue with weight w, the statically allocated bandwidth sba is equal to w*B. The sum of the weights of the queues (e.g., queues 410 ) for a stream equal one. In other words, the entire bandwidth of a stream is allocated to the queues associated with that stream.
The PR parameter specifies which of two priority levels (HI or LO) is associated with a queue. In other implementations, there may be more than two priority levels. Queues 410 associated with a HI priority may be serviced before queues 410 associated with a LO priority. Queues 410 at the same priority level may, for example, be serviced in a round robin manner.
The RC parameter determines whether a queue is allowed to oversubscribe (i.e., output more packet information than its statically allocated bandwidth). If RC is OFF, then the queue is permitted to send up to the stream bandwidth B (the total bandwidth for the stream). If RC is ON, then the queue is rate controlled and not permitted to send more than its statically allocated bandwidth sba.
Each of queues 410 is allocated a particular portion of data memory system 310 that stores packet data corresponding to the packet information stored by the queue. The size of the portion of data memory system 310 allocated to a particular queue (referred to as the static memory allocated sma) may be determined based on the stream's static bandwidth. For example, the sma may be defined as the round trip time (Rtt) multiplied by the statically allocated bandwidth sba. The statically allocated bandwidth sba was defined above. In another implementation, the sma may also take into account the speed of the stream.
The bandwidth allocated to a stream is fixed at B even though different queues within the stream may have dynamically changing bandwidth utilization, as will be described below. The stream itself never needs more than Rtt (round trip time, which is defined as the maximum time allowed for a packet to travel from the source to the destination and send an acknowledgment back)*B of data memory system 310 . This amount of data memory system 310 may be denoted by MA.
A delay bandwidth buffer is an amount of packet information memory system 320 equal to the network round trip time (Rtt) multiplied by the sum of the bandwidths of the output interfaces. An efficient way to allocate the delay bandwidth buffer is to share it dynamically among queues across all output interfaces.
Dequeue engine 420 may include logic that dequeues packet information from queues 410 . The order in which the streams are examined by dequeue engine 420 is referred to as the service discipline. For example, the service discipline may include round robin or time division multiplexing techniques. For each examination of a stream, dequeue engine 420 may select one of queues 410 and dequeue packet information from it. To select the queue, dequeue engine 420 may use the queue parameters w, PR, and RC. For each dequeue operation, the corresponding packet data in data memory system 310 may be read out and processed.
Queue control engine 430 may dynamically control the amount of data memory system 310 used by each queue. Since the total bandwidth for the stream is B, queue control engine 430 effectively controls the total amount of data memory system 310 used by queues 410 in a stream so that it does not exceed MA. The memory is allocated at the time the packet is received and reclaimed either by a drop process if the queue has exceeded its allocation (static and dynamic) or by a dequeue process when the packet is transmitted on a link.
FIG. 5 is an exemplary diagram of queue control engine 430 according to an implementation consistent with the principles of the invention. Queue control engine 430 may include oversubscription engine 510 and drop engine 520 . Oversubscription engine 510 may control whether any of queues 410 are permitted to output more packet information than their statically allocated bandwidth. Drop engine 520 may control whether to drop packet information from any of queues 410 . Oversubscription engine 510 and drop engine 520 will be described in more detail below. While these engines are shown as separate, they may be integrated into a single engine or may otherwise share data between them (connection not shown).
Oversubscription Engine
FIG. 6 is an exemplary diagram of oversubscription engine 510 according to an implementation consistent with the principles of the invention. Oversubscription engine 510 may include bandwidth used random access memory (RAM) 610 , average bandwidth used RAM 620 , timer 630 , and control logic 640 . In an alternate implementation, bandwidth used RAM 610 and average bandwidth used RAM 620 are registers implemented within one or more memory devices, such as a flip-flop.
Control logic 640 may include logic that coordinates or facilitates the operation of the components of oversubscription engine 510 . For example, control logic 640 may perform calculations, write or read data to or from the RAMs, or simply pass information between components of oversubscription engine 510 .
Bandwidth used RAM 610 may include multiple entries, such as one entry per queue. Each of the entries may store a variable that represents the instantaneous amount of bandwidth used (bs) by the queue during a time interval (Ta). When packet information is dequeued by dequeue engine 420 during the time interval Ta, the bs value may be incremented by the length of the corresponding packet. The bs value may be reset at periodic times identified by timer 630 , such as the beginning or end of a time interval.
Average bandwidth used RAM 620 may include multiple entries, such as one entry per queue. Each of the entries may store data that represents a time-averaged measurement of the bandwidth used by the queue (bu) as computed during the time interval Ta. For example, the time-averaged measurement may be determined using an exponential weighted averaging with a decay coefficient chosen to make the computation as efficient as possible (e.g., two adds and a shift per time step). The weights in such an exponential weighted averaging function may be programmable.
FIG. 7 is an exemplary time line that facilitates measurement of bandwidth use according to an implementation consistent with the principles of the invention. The units of bu are bytes/time-step. Let bu[i] be the value of the average bandwidth used as computed in time step i. Let bs[i] be the number of bytes sent by the queue in time step i and n be an integer that determines the decay coefficient (1−2 n ). By expanding the recursion starting at bu[i]:
bu[i]=bu[i− 1]+2 −n ( bs[i]−bu[i− 1])
bu[i]=bu[i− 1]*(1−2 −n )+ bs[i]* 2 −n
Substituting r=(1−2 n ), the equation becomes:
bu [ i ] = bu [ i - 1 ] * r + bs [ i ] * ( 1 - r ) = ( bu [ i - 2 ] * r + bs [ i - 1 ] * ( 1 - r ) ) * r + bs [ i ] * ( 1 - r ) = ( 1 - r ) * ( bs [ i ] + bs [ i - 1 ] * r + bs [ i - 2 ] * r 2 + bs [ i - 3 ] * r 3 + … ) .
As can be seen, the bandwidth used by a queue is a function of the bandwidth used by the queue in all the previous time intervals.
The final equation is an exponential weighted average with coefficient r. To get an idea of how many steps k it takes for the coefficients r k to become “small,” the following binomial expansion may be used:
(1−2 −n ) k ˜1−k*2 −n
as long as k*2 −n is much less than 1. This means that as long as k is significantly less than 2 n , the terms are taken into account almost fully, but as k approaches 2 n , r k will start to drop off rapidly and so the terms become less and less significant.
Returning to FIG. 6 , timer 630 may include a programmable register and/or counter that identifies the times at which time averaging may be performed to generate bu. At the beginning of a programmable time interval Ta, the bs value in bandwidth used RAM 610 may be reset to zero. At the end of the time interval Ta, the current bs value may be read from bandwidth used RAM 610 and the average bu value (computed in the previous time interval) may be read from average bandwidth used RAM 620 . A weighted averaging function may then be performed on these values, such as the one described above, and the resultant value may be stored in average bandwidth used RAM 620 . The bs value in bandwidth used RAM 610 may then be reset to zero again at the beginning of the next time interval Ta+i and the process repeated.
Control logic 640 may reallocate bandwidth to permit oversubscription based on the bandwidth actually used by queues 410 . For example, control logic 640 may determine the average bandwidth bu used by each of queues 410 and reallocate bandwidth to certain ones of queues 410 if the queues permit oversubscription based on the RC parameter associated with the queues.
FIG. 8 is a flowchart of exemplary oversubscription processing according to an implementation consistent with the principles of the invention. In this implementation, control logic 640 performs oversubscription processing at the programmable time interval determined by timer 630 . In other implementations, control logic 640 performs this processing at other times, which may be based on certain criteria, such as traffic flow-related criteria.
Processing may begin with control logic 640 determining the instantaneous bandwidth bs used by queues 410 (act 810 ). To make this determination, control logic 640 may read bs values, corresponding to queues 410 , from bandwidth used RAM 610 . As described above, the bs value for a queue may be calculated based on the length of the packet(s) corresponding to the packet information dequeued by the queue during a time interval.
Control logic 640 may use the bs values and the bu values from the previous time interval to determine the average bandwidth bu used by queues 410 during the current time interval (act 820 ). To make this determination, control logic 640 may take a time-averaged measurement of the bandwidth used by performing an exponential weighted averaging with a decay coefficient chosen to make the computation as efficient as possible (e.g., two adds and a shift per time step). A method for determining the average bandwidth bu has been described above.
Control logic 640 may use the average bandwidth bu to reallocate bandwidth to queues 410 (act 830 ). For example, control logic 640 may identify which of queues 410 permit oversubscription based on the RC parameters associated with queues 410 . If the average bandwidth bu used by a queue is less than its statically allocated bandwidth, the unused portion of the bandwidth may be divided among the queues that are permitted to oversubscribe and need extra bandwidth. Any queue that is not permitted to oversubscribe cannot use any of the unused bandwidth.
FIGS. 9A-9C are exemplary diagrams that illustrate oversubscription according to an implementation consistent with the principles of the invention. Assume that there are four queues Q 0 -Q 3 that share a stream's bandwidth B. Assume further that Q 0 has a weight of 0.7 and Q 1 -Q 3 each has a weight of 0.1. In other words, Q 0 is allocated 70% of the bandwidth B and each of Q 1 -Q 3 is allocated 10% of the bandwidth B. FIG. 9A illustrates such a configuration.
Assume further that RC is OFF for Q 0 -Q 2 and ON for Q 3 . Therefore, Q 0 -Q 2 are permitted to oversubscribe and Q 3 is rate controlled and not permitted to oversubscribe. Assume that Q 0 uses almost none of the bandwidth allocated to it. In this case, Q 1 and Q 2 may share the bandwidth unused by Q 0 . Accordingly, 0% of the bandwidth B is used by Q 0 , 45% is dynamically reallocated to each of Q 1 and Q 2 , and 10% remains allocated to Q 3 . FIG. 9B illustrates such a configuration.
Assume at some later point in time that control logic 640 determines that traffic on Q 0 increases based on the average bandwidth bu used by Q 0 , such that Q 0 requires 40% of the bandwidth B. In this case, Q 0 reclaims some of its bandwidth from Q 1 and Q 2 . Since Q 0 needs 40% of the bandwidth B, the remaining 30% unused by Q 0 is divided between Q 1 and Q 2 . Since Q 0 needs 40% of the bandwidth B, the remaining 30% unused by Q 0 is divided between Q 1 and Q 2 . Therefore, 40% of the bandwidth B is dynamically reallocated to Q 0 , 25% is dynamically reallocated to each of Q 1 and Q 2 , and 10% remains allocated to Q 3 . FIG. 9C illustrates such a configuration.
As can be seen from the foregoing, the bandwidth allocated to queues 410 in a given time interval is related to both the queues' statically allocated bandwidth and the bandwidth used by the queues. This dynamic allocation process may be summarized as: (1) allocating the available bandwidth in proportion to the queues' statically allocated bandwidth; and (2) distributing the excess bandwidth among active queues in proportion to their excess bandwidths used in previous time intervals.
Drop Engine
Drop engine 520 may include RED logic that controls the amount of data memory system 310 used by queues 410 such that the average latency through queues 410 remains small even in the presence of congestion. The drop process is profiled in the sense that the probability of a packet information drop is not fixed, but is a user-specifiable function of how congested a queue is. Generally, the drop process may make its drop decision based on the ratio between the current queue length and the maximum permissible queue length.
Drop engine 520 makes its drop decision based on the state of queues 410 , not on the state of the stream. Drop engine 520 may operate in a round robin fashion on all of the active queues. By design, it has a higher probability of examining more active queues rather than inactive queues to keep up with the data rate of a quickly-filling queue.
The drop decision is made at the head of queues 410 rather than at the tail, as in conventional systems. A benefit of dropping at the head of queues 410 is that congestion is signaled earlier to traffic sources, thereby providing tighter latency control. By comparison, a tail drop can result in the congestion signal being delayed by as much as Rtt compared to a head drop because a more recent packet is being dropped whose response time-out will expire later. Also, if queues 410 are allowed to oversubscribe and use more memory than allocated to them, then head drop provides a way to cut back excess memory use when a queue's bandwidth suddenly drops because a previously inactive queue has started to use its share of the bandwidth again.
FIG. 10 is an exemplary diagram of drop engine 520 according to an implementation consistent with the principles of the invention. Drop engine 520 may include static memory allocated RAM 1010 , memory used RAM 1020 , pending RED visit (PRV) RAM 1030 , indexing logic 1040 , drop profile 1050 , drop decision logic 1060 , and control logic 1070 . In an alternate implementation, static allocated RAM 1010 , memory used RAM 1020 , and PRV RAM 1030 are registers implemented within one or more memory devices, such as a flip-flop.
Control logic 1070 may include logic that coordinates or facilitates the operation of the components of drop engine 520 . For example, control logic 1070 may perform calculations, write or read to or from the RAMs, or simply pass information between components of drop engine 520 .
Static memory allocated RAM 1010 may include multiple entries, such as one entry per queue. Each of the entries may store the variable sma, corresponding to the queue, that identifies the amount of data memory system 310 that should be made available to the queue (in the case where it is not allowed to oversubscribe due to RC being set or all of the other queues using their allocated bandwidth and, thereby, sparing no unused bandwidth). As defined above, sma is defined as the round trip time Rtt multiplied by the statically allocated bandwidth sba.
Memory used RAM 1020 may include multiple entries, such as one entry per queue. Each of the entries may store a variable mu that represents the amount of data memory system 310 actually being used by the queue. Storage space within data memory system 310 may be allocated dynamically at the time a packet is received and reclaimed at some time after the packet is transmitted by router 100 . The variable mu, which counts bytes or cells (e.g., 64 byte data blocks) of data, may be used to track the amount of data memory system 310 used by the queue. When packet information is enqueued, the mu value may be incremented by the length of the corresponding packet. When packet information is dequeued by dequeue engine 420 or dropped by drop engine 430 , the mu value may be decremented by the length of the corresponding packet.
PRV RAM 1030 may include multiple entries, such as one entry per queue. Each of the entries may store a variable pry that controls how many times the queue will be examined by drop engine 430 . When packet information is enqueued, the pry value may be incremented by one. When packet information is dequeued by dequeue engine 420 or an examination of the queue by drop engine 430 occurs, the pry value may be decremented by one, if the pry value is greater than zero. The goal is to allow drop engine 430 to visit each packet at the head of the queue just once. A queue visited once may not be visited again unless the packet just visited got dropped or the packet gets dequeued by dequeue engine 420 .
Indexing logic 1040 may include logic for creating an index into drop profile 1050 . Drop profile 1050 may include a memory that includes multiple addressable entries. Each of the entries may store a value that indicates the probability of a drop. For example, assume that drop profile 1050 includes 64 entries that are addressable by a six bit address (or index). In an implementation consistent with the principles of the invention, each of the entries includes an eight bit number representing a drop probability. The drop probability may always be greater than or equal to zero.
The relationship of drop probability to index may be expressed as a monotonically non-decreasing function. FIG. 11 is an exemplary graph of a drop profile consistent with the principles of the invention. As shown by the graph, the drop profile is a monotonically non-decreasing function with the drop probability of zero at index zero and the drop probability of one at index 63 . In one implementation, an entry value of zero may be used to represent never drop, an entry value of 255 may be used to represent always drop, and entry values in between zero and 255 may represent a drop probability according to the relation:
probability of drop=(entry value)/256.
Returning to FIG. 10 , indexing logic 1040 may generate the index into drop profile 1050 using, for example, the expression:
index=( mu /MAX)*64,
where MAX is the maximum of the values of sma (static memory allocated) and dma (dynamic memory allocated, which is the amount of data memory system 310 that should be made available to a particular queue and is defined as the average bandwidth used bu*(Rtt/Ta)). This may be considered a dynamic index because its value may change based on changes to the variable dma. In an alternate implementation, indexing logic 1040 may generate a static index using, for example, the expression:
index=( mu/sma )*64.
This may be considered a static index because the value of sma will not change. According to an implementation consistent with the principles of the invention, the index generated is a six bit value. In other implementations, other size indexes are possible.
If the situation occurs where mu becomes greater than MAX, then the ratio of mu/MAX results in a value larger than one. When this happens, the index may contain a value that points to somewhere outside drop profile 1050 . In this case, drop decision logic 1060 may consider this a must drop situation and drop the packet unless the packet contains an attribute, such as a keep alive attribute, that indicates that the packet should not be dropped.
In some situations, an index threshold may be used. As shown in FIG. 11 , the drop profile is a monotonically non-decreasing function with the drop probability of zero at index zero and the drop probability of one at index 63 . The index threshold may be set, such that if the index value generated by indexing logic 1040 is less than or equal to the threshold value, the lookup in drop profile 1050 may be skipped and the packet not dropped.
In another implementation consistent with the principles of the invention, packet attributes, such as the packet's Transmission Control Protocol (TCP) and/or Packet Level Protocol (PLP), may be used in conjunction with the index as an address into drop profile 1050 . In this case, drop profile 1050 may include multiple profile tables, each having multiple addressable entries. The packet attributes may be used to select among the profile tables. For example, two bits representing the TCP and PLP of a packet may be used to select among four different profile tables in drop profile 1050 . The index may then be used to identify an entry within the selected table. In this way, a certain set of attributes extracted from the packets may be used to perform an intelligent drop.
Drop decision logic 1060 may include logic that makes the ultimate drop decision based on the drop probability in drop profile 1050 or other factors as described above. In other words, drop decision logic 1060 translates the drop probability into a drop decision for the packet information examined by drop engine 520 .
FIG. 12 is an exemplary diagram of drop decision logic 1060 according to an implementation consistent with the principles of the invention. Drop decision logic 1060 includes random number generator 1210 , comparator 1220 , and AND gate 1230 . Random number generator 1210 may include a pseudo random number generator, such as a linear feedback shift register that creates a pseudo random number that has a uniform distribution between zero and one. Random number generator 1210 may generate a random number that has the same number of bits as the drop probability value from drop profile 1050 . To increase randomness, however, random number generator 1210 may generate a random number that has a greater number of bits as the drop probability value from drop profile 1050 .
Random number generator 1210 may implement functions as represented by the following:
lfsr_galois(int state) { int x0, x5, x12; if (0x0001 & state) { state = state>> 1; state = state {circumflex over ( )} 0x8000 {circumflex over ( )} 0x0800 {circumflex over ( )} 0x0010; } else state = state >> 1; return(state); }
to generate the random number.
Comparator 1220 may compare the random number from random number generator 1210 to the drop probability value from drop profile 1050 . AND gate 1230 may perform a logical AND operation on the result of the comparison and a “DO NOT DROP” signal, which may be generated based on the presence or absence of an attribute, such as a keep alive attribute, that may be extracted from the packet. In an implementation consistent with the principles of the invention, comparator 1220 and AND gate 1230 may be designed to output a drop decision to: (1) drop the packet information if the random number is less than the drop probability value and the DO NOT DROP signal indicates that the packet information may be dropped; (2) not drop the packet information if the random number is less than the drop probability value and the DO NOT DROP signal indicates that the packet information should not be dropped; and (3) not drop the packet information if the random number is not less than the drop probability value regardless of the value of the DO NOT DROP signal.
FIG. 13 is a flowchart of exemplary processing by drop engine 520 according to an implementation consistent with the principles of the invention. Drop engine 520 may operate in parallel to dequeue engine 420 . Therefore, packet information memory system 320 may include mechanisms to arbitrate between drop engine 520 and dequeue engine 420 competing for the same resource (i.e., the same packet information at the head of a queue). In implementations consistent with the principles of the invention, drop engine 520 and dequeue engine 420 may be permitted to access different packet information on the same queue.
Optionally, drop engine 520 may select a stream to examine (act 1305 ). For example, drop engine 520 may use a round robin technique or another technique to determine which of the possible streams to examine next. Alternatively, in another implementation, drop engine 520 may consider all of the queues in a round robin manner without first selecting a stream. In this case, act 1305 may be unnecessary.
Once a stream has been selected, if necessary, drop engine 520 may select a queue to examine based on, for example, the queues' prv values (act 1315 ). The drop engine 520 may use round robin arbitration to select the next queue with a prv value greater than zero.
Alternatively, drop engine 520 may construct two bit vectors (HIVec and LOVec) and perform a round robin over these vectors to select the next queue to examine. The HIVec and LOVec vectors may be defined as follows:
for queue i , where i = 0 to total number of queues: if (mu i > MAX i ), HIVec[i] = 1; else { if (mu i < (MAX i /X)), LOVec[i] = 0; else LOVec[i] = (prv[i] > 0) }
where X is an integer, such as 16. This conserves drop engine 520 examinations of a queue when mu is small compared to MAX and forces drop engine 520 examinations when mu exceeds MAX. When mu is very small compared to MAX/X, the drop probability will be small. Keeping LOVec reset allows drop engine 520 to visit other more active queues.
FIG. 14 is an exemplary diagram of queue selection using the HIVec and LOVec vectors according to an implementation consistent with the principles of the invention. Drop engine 520 may use the two bit vectors HIVec and LOVec to select the next queue to examine. Drop engine 520 may begin searching HIVec at HIPtr+1 looking for the first queue i that has HIVec[i]=1. If there is no such queue, then drop engine 520 may search LOVec starting at LOPtr+1 looking for the first queue i that has LOVec[i]=1.
Returning to FIG. 13 , when drop engine 520 finds a queue i, it determines the variable dma (i.e., the average bandwidth used bu*Rtt) and, from it, the variable MAX (act 1315 ). As described above, MAX is defined as the maximum of the values of sma from static memory allocated RAM 1010 and dma. From MAX, drop engine 520 generates an index into drop profile 1050 (act 1320 ). As described above, the index may be defined as: mu/MAX*64. In this case, the generated index may be a six bit number.
If an index threshold (T/H) is used, drop engine 520 may compare mu/MAX to the threshold to determine whether mu/MAX is less than or equal to the threshold (act 1325 ). If mu/MAX is less than or equal to the threshold, drop engine 520 may mark the packet as not to be dropped (act 1330 ). Marking may be done by simply setting a bit associated with the packet or by not dropping packet information from the queue.
If mu/MAX is greater than the threshold, drop engine 520 may determine whether mu/MAX is greater than or equal to one (act 1335 ). If so, then drop engine 520 may determine whether the packet includes a packet attribute, such as a keep alive attribute, that indicates that it is not to be dropped (act 1340 ). The presence or absence of this packet attribute may be used to generate the DO NOT DROP signal. If the DO NOT DROP signal indicates that the packet should not be dropped, then drop engine 520 may mark the packet as not to be dropped (act 1345 ). Otherwise, drop engine 520 may mark the packet for dropping (act 1350 ).
If mu/MAX is less than one, however, drop engine 520 may use the index to access drop profile 1050 and obtain a drop probability (act 1355 ). If drop profile 1050 contains more than one profile table, drop engine 520 may use packet attributes to select one of the profile tables. Drop engine 520 may then use the index as an address into the selected profile table and read a drop probability value therefrom.
Drop engine 520 may determine a drop decision by comparing the drop probability value to a random number (acts 1360 and 1365 ). The random number may be generated by random number generator 1210 . If the random number is less than the drop probability value, drop engine 520 may determine whether the packet includes a packet attribute, such as a keep alive attribute, that indicates that it is not to be dropped (act 1370 ). The presence or absence of this packet attribute may be used to generate the DO NOT DROP signal.
If the random number is less than the drop probability value and the DO NOT DROP signal indicates that the packet may be dropped, then drop engine 520 may mark the packet for dropping (act 1375 ). If the DO NOT DROP signal, in this case, indicates that the packet is not to be dropped, then drop engine 520 may mark the packet as not to be dropped (act 1380 ). If the random number is not less than the drop probability value, regardless of the value of the DO NOT DROP signal, then drop engine 520 may mark the packet as not to be dropped (act 1380 ). Marking may be done by simply setting a bit associated with the packet or by dropping or not dropping packet information from the queue.
In response to a decision to drop, drop engine 520 may remove the associated packet information from the queue. Alternatively, the queue may discard the packet information itself when instructed by drop engine 520 .
CONCLUSION
Systems and methods, consistent with the principles of the invention, provide head-of-queue dropping mechanisms that make their drop decision based on the state of queues, not on the state of the corresponding stream. The dropping mechanisms examine active queues more frequently than inactive queues to keep up with the data rate of a quickly-filling queue. Moreover, the drop decision is made at the head of the queues rather than at the tail, as in conventional systems. A benefit of dropping at the head of the queues is that congestion is signaled earlier to traffic sources, thereby providing tighter latency control.
The foregoing description of preferred embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. For example, dequeue engine 420 and queue control engine 430 have been described as separate components. In other implementations consistent with the principles of the invention, the engines may be integrated into a single engine that both dequeues and drops packet information.
Also, while some memory elements have been described as RAMs, other types of memory devices may be used in other implementations consistent with the principles of the invention.
Certain portions of the invention have been described as “logic” that performs one or more functions. This logic may include hardware, such as an application specific integrated circuit or a field programmable gate array, software, or a combination of hardware and software.
No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. The scope of the invention is defined by the claims and their equivalents. | A system selectively drops data from a queue. The system includes queues that temporarily store data, a dequeue engine that dequeues data from the queues, and a drop engine that operates independently from the dequeue engine. The drop engine selects one of the queues to examine, determines whether to drop data from a head of the examined queue, and marks the data based on a result of the determination. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to using components within a dishwasher to protect a dishwasher from freezing.
BACKGROUND OF THE INVENTION
[0002] Automatic dishwashers can be severely damaged when exposed to low temperatures for a duration long enough to cause water to freeze. These appliances have standing water present at all times in the pump assembly which is usually mounted at the bottom of the tub. Domestic water is also present in the supply line, while rinse water remains in the low point of the drain hose. All of these parts are subject to mechanical damage due to the expansion of water during a freeze. The pump, which is usually integral to the motor and/or transmission, is a particularly expensive component of an automatic dishwasher. Beyond the expense to replace whichever component is damaged, a significant labor charge is incurred to have a service technician remove the appliance from the cabinet, disassemble it, and replace it. Collateral damage to the home is also avoided as a cracked pump or water line can flood the environment after a thaw.
[0003] There are many reasons why a dishwasher could be exposed to temperatures which would cause the residual water to freeze. This is a particular concern in northern climates during the winter months.
[0004] Kitchens are often difficult to heat, due to the lack of baseboard for heat radiators. The need for appliances and cabinets along the walls, plus the need for various doorways into the room, can limit the linear feet available for baseboard heat.
[0005] Exterior doors are often placed in or near the kitchen which can allow cold air from outdoors to enter the room. Older homes may have poor or no insulation allowing cold air to penetrate the space behind an automatic dishwasher.
[0006] An automatic dishwasher could be installed on an outside wall, between base cabinets and under a countertop, which limits its exposure to the heated room. A dishwasher could be placed on a northern wall, which has limited sun and tends to be cold.
[0007] A kitchen may have the room heat reduced by a set-back thermostat for up to 12 hours over night between the evening meal and breakfast. A kitchen is often non-occupied between these hours.
[0008] The dishwasher maybe installed in a vacation home, such as a ski lodge or cabin, with the heat set to a low temperature during periods of non-occupancy. The unit may be installed in a pantry, garage, or storage area with limited or no heat.
[0009] U.S. Pat. No. 7,837,127 relates to a ventilation system for exchanging the air in a room with outside air. The system comprises a fine wire heat exchanger having a first channel and a second channel, which channels are in heat exchanging contact with each other, and wherein the first channel has an inlet connected to outside air and an outlet connected to the air in the room, and wherein the second channel has an inlet connected to the air in the room and an outlet connected to the outside air, balancing means for balancing the flow in both channels, such that the heat transfer is maximized.
[0010] U.S. Pat. No. 5,560,060 relates to a system and method for adjusting the operating cycle of a cleaning appliance. A controller having a decision system receives turbidity and temperature measurements from turbidity and temperature sensors and uses these measurements to adjust the operating cycle of the machine to the level of soil of the articles to be washed, the rate of soil removal, and the temperature of the water used for washing.
[0011] U.S. Pat. No. 5,984,194 relates to a valve for use in machines for washing, such as laundry machines and dishwashers, that includes a hollow valve body wherein a current of water flows, entering the valve body via at least one inlet of the valve, and at least one plug element for allowing and preventing the outflow of water from a corresponding outlet of the valve. The valve is connected to at least one temperature sensor device having an open and closed condition of an electrical connection and in that the sensor device has a preset trigger temperature which, when reached, causes the change from a state of closure to one of opening of the connection or vice versa.
[0012] U.S. Pat. No. 6,625,850 relates to a dishwasher sanitation cycle that includes sampling a temperature of rinse water inside a dishwasher, executing a heating cycle to keep water temperature at optimal levels, and executing a heat sum cycle to ensure that dishes are sanitized according to accepted standards.
[0013] US patent publication 2011/0224834 relates to a method for identifying operating conditions of a domestic appliance, a temperature of an operating agent of the appliance or of a component detected by a temperature sensor. The ambient temperature is detected by the temperature sensor before the programming mode, in an initialization phase. At least one reference temperature value is defined that represent a critical value for the programming mode of the appliance. The programming mode is prevented from beginning as a function of the comparison of the measured ambient temperature with at least one reference temperature value. The programming mode is prevented from beginning until the ambient temperature has reached a value that is in an acceptable range in comparison with the reference temperature value.
[0014] US patent publication 2010/0126604 relates to a demand type, multiple use, hot water distribution and freeze protection system and method that responds to the user's desire for hot water at a particular sink or fixture by delivering hot water rapidly to that fixture only, without running water down the drain. The system requires only one pump at the water heater, and does not require a dedicated hot water return line, but works with a dedicated line in retrofit applications. Circulating water in the plumbing system can also be used to protect plumbing from freeze damage. Each valve and activation device operates by transmitting a start command to the valve controller which sends the pump controller a start signal, the valve to open, hot water to circulate and the valve to close when the hot water arrives at the fixture preventing heated water from filling the cold water line.
SUMMARY OF THE INVENTION
[0015] The present invention relates to using components within a dishwasher to protect a dishwasher from freezing. Dishwasher appliances contain a heating element which is intended to dry the dishes after they have been cleaned and rinsed. Automatic dishwashers universally have a water pump at the base of the washing tub which ejects the waste water from the home's sewer line. Dishwashers are supplied hot water from the home's domestic plumbing system. A sensor to determine the appliance's door is closed is present to prevent flooding.
[0016] The present invention comprises a temperature sensing component and accompanying control circuit. It is an object of the present invention to mount the temperature sensor at the coolest expected location, such as the bottom rear of the appliance. The sensor activates the freeze protection function once the ambient temperature fails to be just above the freezing point, for a safety margin. It is an object of the present invention for the freezing point to be approximately 37 degrees F.
[0017] It is an object of the present invention for the control circuit that confirms the door is closed to admit hot water to the appliance for a period of time sufficient to allow heated water to travel from the home's water heater to the dishwasher.
[0018] It is an object of the present invention to have an activation period of approximately two (2) minutes to be sufficient, however, another duration can be designed.
[0019] It is an object of the present invention for the function of admitting hot water to be accomplished by the existing water valve/solenoid and controls used to operate an ordinary wash cycle. This will heat the dishwasher's supply line sufficiently to prevent freezing of this part of the system.
[0020] It is an object of the present invention for the hot water to be provided to be ejected into the drain hose via operation of the drain pump. It is an object of the present invention for this function to be accomplished by activating the pump via the control used to conclude a rinse cycle. This will heat the dishwasher's pump and drain line sufficiently to prevent freezing of this part of the system.
[0021] It is an object of the present invention for the heating element in the appliance to be energized using the existing thermostatic controls used for dish drying. The element remains in the heating mode until the temperature sensing component returns an ambient temperature. It is an object of the present invention for the ambient temperature to be approximately 45 degrees F. At the point the sensing component returns an ambient temperature the automatic freeze protection cycle is concluded.
[0022] Therefore, as shown above the local environment of the dishwasher has been heated a certain temperature above freezing. This will protect the appliance, for significant periods of time, from damage due to a freeze of standing water in the pump, drain, and/or supply line as there systems re-cool. The duration of protection will depend on the ambient conditions of the general area.
[0023] It is an object of the present invention for the system to reactivate if the threat of freezing recurs as indicated by a fall in ambient temperature, for example, to 37 degrees F.
[0024] It is an object of the present invention for the automatic dishwasher product to have the automatic freeze protection incorporated into the appliance in either a manual or fully automatic mode.
[0025] The manual mode requires the operator to engage the automatic freeze protection system if freezing temperatures are expected. The automatic mode operates in the background without user interaction to protect the appliance automatically.
[0026] It is an object of the present invention for the majority of the elements necessary to perform the automatic freeze protection to be present in household dishwashers. One additional requirement is the addition of a temperature sensor.
[0027] It is an object of the present invention for machines already equipped with an electronic control module, for the modification of the software to include the automatic freeze protection.
[0028] It is an object of the present invention for machines that are controlled using an electro-mechanical clock system to have the addition of a similar timer module to control the automatic freeze protection function.
[0029] The present invention combines the use of a temperature sensor wire and minor control implementation, for the user of a dishwasher appliance to have their dishwasher protected from expensive damage in the event the appliance is subject to freezing temperatures.
[0030] The present invention relates to a method for protecting a dishwasher from freezing comprising: activating a freeze protection function on a control circuit due to a temperature sensor detecting that ambient temperature is below freezing point. The control circuit senses whether the dishwasher door is closed. After sensing that the door is closed hot water is supplied from the home's domestic plumbing system sufficient for heated water to travel to the dishwasher. The hot water is supplied by existing water valve/solenoid and controls used to operate an ordinary wash cycle. The dishwasher's supply line is heated sufficiently to prevent freezing of this part of the dishwasher. Hot water is ejected via a drain hose from the drain pump. The hot water heats the dishwasher's pump and drain line sufficiently to prevent freezing of this part of the dishwasher. The components of the dishwasher are heated via a heating element until the temperature sensor returns an ambient temperature above freezing point. The freeze protection function concludes when the temperature sensor returns an ambient temperature above freezing point. The freeze protection function reactivates if the threat of freezing recurs as indicated by a fall in ambient temperature.
BRIEF DESCRIPTION OF THE FIGURES
[0031] FIG. 1 shows an internal view of an embodiment of the automatic freeze protection system for a dishwasher of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] FIG. 1 shows dishwasher 10 having a controller 12 that is located within the dishwasher 10 but located outside the dishwasher for clarity. The dishwasher 10 has a hot water valve 14 that is connected to a domestic hot water supply 16 . The dishwasher 10 has a heating element 18 . The dishwasher 10 comprises a pump 20 that has a waste water discharge line 22 . The controller 12 is connected to a temperature sensor 24 , and is also connected to a door position switch 26 . The controller 12 is also connected to the pump 20 , hot water valve 14 , and heating element 18 .
[0033] In an embodiment, the temperature sensor 24 is mounted at the coolest expected location, such as the bottom rear of the appliance. The sensor 24 activates the freeze protection function of the controller 12 once the ambient temperature fails to be just above the freezing point, for a safety margin. In an embodiment, the freezing point is approximately 37 degrees F.
[0034] The control circuit 12 confirms the door is closed by door position switch 26 and admits hot water through hot water valve 14 to the dishwasher 10 for a period of time sufficient to allow heated water to travel from the home's water heater to the dishwasher 10 .
[0035] In an embodiment, the control circuit has an activation period of approximately two (2) minutes to be sufficient, however, another duration can be designed.
[0036] The hot water valve 14 also admits hot water to operate an ordinary wash cycle. This will heat the dishwasher's supply line sufficiently to prevent freezing of this part of the system.
[0037] In an embodiment, the hot water is provided to be ejected into the drain hose 22 via operation of the drain pump 20 . In an embodiment, this function is accomplished by activating the pump 20 via the control 12 which is also used to conclude a rinse cycle. This will heat the dishwasher's pump 20 and drain line 22 sufficiently to prevent freezing of this part of the system.
[0038] The heating element 18 in the appliance 10 is energized using the existing thermostatic controls used for dish drying. The element 18 remains in the heating mode until the temperature sensing component 24 returns an ambient temperature above the freezing point. In an embodiment, the ambient temperature is approximately 45 degrees F. At the point the sensing component 24 returns an ambient temperature above freezing point, the automatic freeze protection cycle is concluded.
[0039] The device of the present invention when activated heats the dishwasher to a certain temperature above freezing. This protects the appliance, for significant periods of time, from damage due to a freeze of standing water in the pump 20 , drain, and/or supply line as their systems re-cool. The duration of protection will depend on the ambient conditions of the general area.
[0040] In an embodiment, the system of the present invention reactivates if the threat of freezing recurs as indicated by a fall in ambient temperature once again, for example, to 37 degrees F.
[0041] In an embodiment, the automatic dishwasher has the automatic freeze protection incorporated into the appliance in either a manual or fully automatic mode.
[0042] In an embodiment, the manual mode of the present invention requires the operator to engage the automatic freeze protection system if freezing temperatures are expected. The automatic mode operates in the background without user interaction to protect the appliance automatically.
[0043] The present invention combines the use of a temperature sensor and minor control implementation, for the user of a dishwasher appliance to have their dishwasher protected from the expensive damage in the event the appliance is subjected to freezing temperatures. | A system for protecting a dishwasher from freezing using components within a dishwasher. The system comprising: a control circuit, a heating element, a water pump, drain hose, hot water supply, water valve, door sensor to determine whether dishwasher door is closed and a temperature sensor. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The improved strap, in all forms thereof, was especially devised for use in fitting out the upholstered interior of a passenger automobile. However, various other applications may well be found in other types of product, for example, hand grips for luggage, in manually operated cabinet work components, and the like.
2. Description of the Prior Art
To our knowledge, the most pertinent prior art is represented by the manufacturing procedure for existing conventional automotive door pull straps, comprising a base strip, a backing strip and a facing, but otherwise lacking the special cushioning and other features and advantages mentioned in the Abstract.
That is, in the prior making of related or comparable automotive interior pull strap fittings of which we are aware, the product essentially comprised an elongated steel stabilizing base strip have longitudinally superimposed thereon an elongated extruded vinyl backing strip. This backing member had a vinyl-coated fabric facing sheet or strip stitched centrally therealong, thus constituting a two-part sub-assembly of the plastic-containing components.
With a preliminary lamination of steel and plastic components, the vinyl-coated facing strip was wrapped about the unit and had its plastic containing components thermally fused together under high frequency dielectric heat along the longitudinal seam zone of the facing sheet edges as overlapped, i.e., at the area of contact of said facing component with the vinyl backing strip.
However, as bracket-mounted to an upholstered interior door panel, the strap presented a rigid, unyielding feel to the finger grasp of the car occupant, a feature which is unacceptable in present day automobile interior equipment, particularly in the luxury class car.
SUMMARY OF THE INVENTION
In all of the embodiments shown herein the strap is made up of an elongated, flexible steel bracing or base strip, conventionally formed at its ends for mounting to the inner upholstered panel of the door of the vehicle, as by conventional molded plastic or die-cast end brackets. This steel base is abutted, along the major intermediate length of its surface which will be toward said door panel, by an elongated cushion or pad of vinyl foam, sponge rubber or equivalent, this element being somewhat greater in width than the steel base strip and being of generous thickness for the desired feel.
The surface of the steel strip abutted by the cushion or pad is by preference coated with plastisol to afford a good adhesion of these parts when the plastic components are heat-activated in the manner to be described, whereupon an externally vinyl-coated fabric facing strip or sheet is snugly wrapped, fabric side in, about the steel base and cushion member sub-assembly. As for the cushion member per se, it may, as noted above, be a foam product, or it may derive its yieldability from its inherent elasticity, if of solid material, or by the formation of air channels therein and therealong.
With the base and cushion parts in place and the vinyl-coated facing sheet wrapped snugly therearound and well overlapped at a substantial seam zone centrally therealong opposite the cushion, an attractive elongated external trim strip member of one sort or another (to be described) is placed along the seam overlap. The four parts being snugly held together in a die unit, and under tensioning of the wrapped facing strip as described, the plastics of said facing and trim strips, also their plastic interbond, if present, are thermally energized dielectrically at radio frequency to produce an intimate fusion thereof due to the molecular activity of the heated plastic material. The thus formed strap product, when cooled to set it plastic-wise, is then shaped physically in an appropriate forming die or fixture so as to produce a mildly arcuate conformation spacing it centrally from the door panel, to be readily grasped by the user.
In regard to the seaming of the vinyl-coated facing strip or sheet, one aspect of the invention contemplates that its seam edges be oppositely rabbeted, so that as well lapped and heat sealed together they provide a surface of uniform thickness across the width of the steel base strip engaged thereby. Another variant employs an edge-butted relationship along the seam to the same end.
It is to be understood that while a vinyl composition is herein instanced as the preferred plastic for use in the indicated parts, and a radio-frequency dielectric fusion for activation of their bond, other equivalent materials and concepts are contemplated, save as limited in the claims to follow.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view in longitudinal center cross-section, partially broken away and on a line corresponding to line 1--1 of FIG. 2, of one of the preferred embodiments of the cushioned strap construction in a rabbeted-seam type, the view showing the relationship of the strap to an upholstered automotive interior panel which appears in dot-dash line;
FIG. 2 is an enlarged scale view of this construction in transverse vertical cross-section plane along line 2--2 of FIG. 1;
FIG. 3 is a sectional view similar to FIG. 2 of a closely related alternative and preferred embodiment of the strap construction, in which an edge-butted facing strip seam is employed;
FIG. 4 is a similar sectional view, of a rather skeletal nature, showing an optional unwrapped sub-assembly of a foam cushion strip, a base strip and a base and cushion-locating and adapter component, the latter being undercut-grooved for the purpose and being in this case a molting or extrusion of a relatively solid material such as rubber or yieldable plastic having internal passaging therealong to impart a resilient compressability thereto;
FIG. 5 is a sectional view, partially broken away and generally similar to FIG. 1, of an alternative early form of the strap fitting, being in vertical longitudinal cross section in a plane central of the strap, this view showing laminated components including a seam-concealing trim strip, a steel base strip, a foam cushion strip, a wrap-around facing strip or sheet, and also an extruded plastic adapter strip which is absent as such, in the embodiments of FIGS. 2 and 3, but has an equivalent in the FIG. 4 embodiments;
FIG. 6 is a fragmentary plan view of the strap of FIG. 5, being partially broken away along its length to show the various individual plastic and metal components;
FIG. 7 is an enlarged scale view in transverse section on line 7--7 of FIG. 5;
FIG. 8 is a fragmentary perspective and transversely sectioned view showing partially assembled components of another earlier rabbet-seamed strap construction which also affords an air-cushioned feel to the grip of the occupant; and
FIG. 9 is a similar fragmentary perspective and sectioned view showing the article of FIG. 8 in a fully bonded and completed form.
DESCRIPTION OF PREFERRED EMBODIMENTS
One embodiment of the luxury-type fitting of the invention, as illustrated and generally designated 10 in FIGS. 1 and 2, comprises a dielectrically fused lamination of strip components including an elongated fabric-backed facing strip or sheet 12, (edge-lapped portions of which are later described), which strip is externally face-coated with a dielectrically activatable thermoplastic coating composition, preferably, as appears from the above, a vinyl formulation. This is colored and/or textured to match, blend or contrast with the upholstery of the inner panel P of an automobile door or other interior finish surface. In applications other than to an automotive fitting, material, coloration and texture will be appropriate to the desired purpose.
The composition of the plastic facing (and this also applies to other vinyl or equivalent plastic components of the product) is such that it dielectrically fuses and bonds with the material of any other resinous component, typically under radio frequency electric current of the order of 271/4 megacycles per second. The resultant extreme inter-polar molecular activity of the facing composition of strip 12 and other like plastic components produces a rapid and intimate bonding fushion of all thereof which engage another related type surface, including the trim strip and plastic adhesive components later referred to. The facing vinyl permeates its fabric backing and bonds integrally with other such parts. It is to be understood that this thermal fushion is performed only after all the components of the embodiment 10 have been completely assembled in place and held together, as in an appropriate heating form, press or fixture (not shown) which is electrically energized at the indicated frequency.
The strap 10 comprises an elongated and relatively thick pad or cushion strip 14, shown as being an extruded or otherwise molded section of vinyl, rubber or polyurethane foam and substantially coextensive but slightly shorter as illustrated in length than the main body portion of the fitting 10 as shown in FIG. 5.
Pad or cushion 14 is sectionally shaped (FIG. 2) to provide a transversely elongated undercut groove or slot 15 which bottoms along a major portion of the transverse width of a main body portion 16 of the pad and opens longitudinally as the latter's ends; and the side edges of undercut groove 15 are defined by the inturned flange portion 17 of two like shoulders 18 integral with the pad body 16.
A second essential component of the strap 10 is an elongated flexible steel stabilizing base strip 19 whose transverse width is only slightly (if at all) less than that of the undercut groove 15. Strip 19 is pre-coated on its surface which will face opposite the pad or cushion body 16 with an appropriate thermally activated or energizable plastisol adhesive composition 20, and easy access of steel strip 19 to the groove 15 is had by first bending out and then releasing the pad shoulders 18, thus properly locating and confining base strip 19.
Typically, for the pull strap use contemplated by the invention, the steel component 19 has a central body midportion which is substantially coextensive but slightly longer as illustrated in its own length with the cushion 14, which body portion is provided at opposite ends with conventional reduced width tabs 21, as shown in FIG. 1. These are apertured at 22 for mounting the strap 10 to molded plastic bracket pieces B, as by bolt or stud means. The strap member is fixedly attached to the inner door panel or other mounting surface through the agency of these bracket provisions.
The fabric-backed and vinyl-coated facing strip or sheet 12 referred to above is applied reasonably tightly around the base and cushion strip sub-assembly, being drawn snugly about the rounded cushion shoulders 18; and the edges of strip 12 are substantially overlapped flatwise on one another along a relatively wide central seam zone. Said edges are each rabbeted and lap-mated at 23 along their relatively wide extreme outer portions to aford a resultant flat-lapped seam or joint which is, as best shown in FIG. 2, of the same overall thickness as the remaining un-rabbeted body of the facing strip 12.
With said wrapped strip under tension, a final ornamental trim strip 24 is laid in place along and over the seamed joint zone, wholly covering the latter and being centered between the wrapped cushion pad shoulders 18. Strip 24 may be, for example, a relatively thin steel length ornamentally finished on its exposed surface, as typically by anodizing; or it may be a non-metallic length of resin-impregnated body cloth or the like, of the sort later referred to. Its length equals that of facing 12. A length of a plastic composition such as Mylar is also contemplated.
Following this the application of dielectric fusing heat at the previously mentioned high frequency completes the union of parts. The highly thermo-conductive quality of the steel strip 19 of course promotes a fast and uniform distribution of dielectric heat to the non-metallic parts; such parts include the plastisol upper coating 20 of strip 19 and, as desired, another such coating 20 on its opposite side. This union of parts will inherently prevent any shifting of the facing strip relative to the base strip.
The embodiment of the improved strap fixture appearing in FIG. 3, and generally designated 30, is very similar to that of FIGS. 1 and 2, to the extent that corresponding numerals, primed, are employed to designate corresponding parts and further description thereof is dispensed with.
Strap 30, for one thing, embodies an edge-butted relationship at 31 of its seamed edge areas, rather than the rabbeted and overlapped seaming zones 23 of the first form. A constant thickness joint then exists across the portion of the width of the steel base strip 19 which engages said seamed joint. Moreover, in this case the seam is concealed by a length of a Mylar extrusion, specially designated 32, having an attractive finish, for example a wood-grained one bordered by simulated chrome stripes; and many other types of trim stripping are of course available in substitution for the ornamental metal trim of FIGS. 1 and 2. Furthermore, an appropriate resin-impregnated body cloth or a fabric-backed vinyl sheeting are optional trim strip substitutes in any embodiment of the invention. As will appear from FIG. 4, the foam pad or cushion strip may be supplemented by an additional yieldable strip component which affords not only means for laterally locating and confining said cushion, but also similarly receives and retains the flexible steel base strip.
Thus, FIG. 4 illustrates a sub-assembly 34 of a foam cushion pad 35, a steel stabilizing and base strip 36 and an intermediate adapter strip length 37 of solid section, for example an extrusion or otherwise molded section of rubber or equivalent resilient elastomer. This adapter strip has an elongated wide bottom groove 38 defined by parallel side lips 39 between which the pad 35 is snugly received.
The strip 37 has integrally molded shoulders 40 contoured similarly to the shoulders 18 and 18' of the prior forms 10 and 30, and between said shoulders an undercut groove 41 is formed in the strip. This is in part defined by inwardly extending lips 42 of the shoulders, which lips resiliently retain base strip 36 from above. As in the case of the straps 10 and 30, the shoulders 40 are to be rolled back to expose groove 41 to receive the strip 36, then released onto the latter above the side undercuts of the cushion groove.
For the purpose of enhancing its resilient compressibility, the adapter strip 37 is formed to provide parallel elongated air channels 43 in and along each of its rounded shoulders 40; and the sub-assembly unit 34 will have a vinyl or equivalent coated facing sheet (not shown) snugly wound about it under tension, then dielectrically bonded, seamed and finish-ornamented to conceal the seaming, exactly as described above in the case of the strap structures 10 and 30.
Pursuant to one of the earlier developments of the invention the strap fitting, as illustrated in FIGS. 5, 6 and 7 and generally designated 44, is characterized by a resin-coated facing strip 45, a steel base strip 47 having reduced width mounting extensions 48, and adapter extrusion strip 49 (generally similar to the adapter 37 of FIG. 4) and an ornamentation strip 50, all have the characteristics previously described, hence need no further amplification. In this case the adapter 49 has a flat and relatively wide body portion which carries on its lower surface a pair of integral ribs 51 for stable intermediate engagement with steel strip 47 upon opposite sides of these ribs; and the adapter's side edges carry rounded shoulder portions 52. These have stable flatwise engagement with base strip 47 along the latter's edges, and they terminate in integral bottom lips 53. Said lips are spaced from one another but a trifle more than the width of the strip 47, so as to mate over the edges of the latter, as illustrated in FIG. 7, and thus assist in registering and laterally confining the base and cushion parts against lateral shift. A heat activatable bonding agent may be employed, if desired. The edges of facing strip are shown as having a plain seam overlap at 54.
In the further alternative construction of FIGS. 8 and 9, specially designated by the reference numeral 55, a vinyl or other plastic extrusion 56 is sectioned to form three elongated and separate parallel cavities or air passages 57 which are coextensive in length with the extrusion. These are defined by separate external and convexly rounded hollow bead-like formations 58. Thus, a resilient cushioning "soft feel" action is imparted to said piece along the lateral surface thereof at which the finished strap fitting 55 of this form is felt by the fingers of the user.
Prior to being wrapped about the extrusion 25, the plastic-backed fabric facing sheet or strip has said extrusion secured in place thereon by parallel lines of machine stitching 60 between the hollow air-cushioning formations 58. Thus, a two-part sub-assembly of cushioned strip members may be prefabricated for later mass completion. The completed strap fitting of this form appears partially in FIG. 9.
On its surface opposite the convexly molded surface the strip 56 carries a pair of parallel integral ribs 61 between which the steel stabilizing base strip 62 is registered and laterally held in place.
The molded plastic part above referred to further carries a pair of generally similar wide longitudinally extending parallel legs or flanges 63, 64 integral with and along its sides. Said flanges are molded along their extreme outer zones to afford reduced-thickness, oppositely rabbeted lap extensions 65, which are so proportioned that, after the flanges 63, 64 have been bent inwardly toward one another and down onto the steel strip 62, a resultant flat-lapped joint zone at 66 is, as best shown in FIG. 9, of the same overall thickness as the remainder of the flange portions. In this respect the sectioning of the extrusion flanges resembles that of the rabbeted facing edge joint 23 of the embodiment of FIGS. 1 and 2. High frequency dielectric fusing heat completes the union of parts. | The fitting is an elongated door or like pull strap which is ornamental and well suited for blending, or contrasting, with the decor of a passenger automobile interior. Certain embodiments are intended for installation on a door or other interior panel of a vehicle of the so-called luxury type; in other adaptations use in a less expensive or standard, less luxuriously appointed vehicle is contemplated. However, in all forms a basic and common feature relates to a bracket-mounted strap which presents a well cushioned or padded surface which faces the associated auto panel and is therefore felt by the fingers of the hand of a vehicle occupant; this is diametrically opposed to a finger grip on the rigid, inherently unyielding surface characteristic of automotive door and related pull straps in current use, which surface faces the panel also. | 8 |
TECHNICAL FIELD AND BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method for manufacturing a primary preform for optical fibres using an internal vapour deposition process, comprising the steps of:
[0002] i) providing a hollow glass substrate tube having a supply side and a discharge side,
[0003] ii) surrounding at least part of the hollow glass substrate tube by a furnace,
[0004] iii) supplying glass-forming gases to the interior of the hollow glass substrate tube via the supply side thereof,
[0005] iv) creating a reaction zone with conditions such that deposition of glass will take place on the inner surface of the hollow glass substrate tube, and
[0006] v) moving the reaction zone back and forth along the length of the hollow glass substrate tube between a reversal point located near the supply side and a reversal point located near the discharge side of the hollow glass substrate tube so as to form one or more preform layers on the inner surface of the hollow glass substrate tube, both of which reversal points are surrounded by the furnace.
[0007] A method as described in the introduction is known per se from U.S. Pat. No. 4,741,747. More in particular, the aforesaid patent discloses a method of fabricating optical preforms according to the PCVD method, wherein glass layers are deposited by moving a plasma back and forth between two points of reversal inside a glass tube whilst adding a reactive gas mixture to the tube at a temperature between 1100° C. and 1300° C. and a pressure between 1 and 30 hPa. The regions of nonconstant deposition geometry at the ends of the optical preform are reduced by moving the plasma nonlinearly with time in the area of at least one reversal point.
[0008] U.S. patent application US 2003/0017262 relates to an apparatus and method for manufacturing an optical fiber preform. From said US application it is known that two separate heat sources are positioned a predetermined distance apart, seen in the longitudinal direction of the substrate tube. The two heat sources are moved along the length of the substrate tube whilst maintaining the predetermined spacing during the MCVD (Modified Chemical Vapour Deposition) process.
[0009] U.S. Pat. No. 4,608,070 discloses a process for manufacturing a preform wherein the deposition process is carried out using a temperature profile, which temperature profile increases along the length of the substrate tube.
[0010] German Offenlegungsschrift DE 32 06 17 discloses a method for manufacturing a preform wherein a graphite furnace surrounds a substrate tube, which graphite furnace is provided with an additional heat source, which heat source functions as a pre-heater for the gas mixture to be supplied to the substrate tube. The two heat sources can be moved over the tube along the length thereof while maintaining the spacing between the two heat sources.
[0011] German Offenlegungsschrift DE 36 19 379 relates to a method and device for manufacturing a preform, wherein two co-axially arranged tubes can be heated and cooled independently so as to thus effect a temperature change.
[0012] U.S. Pat. No. 4,331,462 relates to a method for manufacturing a preform by means of an MCVD process, using a so-called tandem heating zone made up of a zone I and a zone II.
[0013] An optical fibre consists of a core and an outer layer surrounding said core, also referred to as cladding. The core usually has a higher refractive index than the cladding, so that light can be transported through the optical fibre.
[0014] The core of an optical fibre may consist of one or more concentric layers, each having a specific thickness and a specific refractive index or a specific refractive index gradient in radial direction.
[0015] An optical fibre having a core consisting of one or more concentric layers having a constant refractive index in radial direction is also referred to as a step-index optical fibre. The difference between the refractive index of a concentric layer and the refractive index of the cladding can be expressed in a so-called delta value, indicated Δ i % and can be calculated according to the formula below:
[0000]
Δ
i
%
=
n
i
2
-
n
cl
2
2
n
i
2
[0016] where:
[0017] n i =refractive index value of layer i
[0018] n cl =refractive index value of the cladding
[0019] An optical fibre can also be manufactured in such a manner that a core having a so-called gradient index refractive index profile is obtained. Such a radial refractive index profile is defined both with a delta value Δ% and with a so-called alpha value α. To determine the Δ% value, use is made of the maximum refractive index in the core. The alpha value can be determined by means of the formula below:
[0000]
n
(
r
)
=
n
1
(
1
-
2
Δ
%
(
r
a
)
α
)
1
2
[0020] where:
[0021] n i =refractive index value in the centre of het fibre
[0022] a=radius of the gradient index core [μm]
[0023] α=alpha value
[0024] r =radial position in the fibre [μm]
[0025] A radial refractive index profile of an optical fibre is to be regarded as a representation of the refractive index as a function of the radial position in an optical fibre. Likewise it is possible to graphically represent the refractive index difference with the cladding as a function of the radial position in the optical fibre, which can also be regarded as a radial refractive index profile.
[0026] The form of the radial refractive index profile, and in particular the thicknesses of the concentric layers and the refractive index or the refractive index gradient in the radial direction of the core determine the optical properties of the optical fibre.
[0027] A primary preform comprises one or more preform layers which form the basis for the one or more concentric layers of the core and/or part of the cladding of the optical fibre that can be obtained from a final preform. A preform layer is built up of a number of glass layers.
[0028] A final preform as referred to herein is a preform from which an optical fibre is made by using a fibre drawing process.
[0029] To obtain a final preform, a primary preform is externally provided with an additional layer of glass, which additional layer of glass comprises the cladding or part of the cladding. Said additional layer of glass can be directly applied to the primary preform. It is also possible to place the primary preform in an already formed glass tube, also referred to as “jacket”. Said jacket may be contracted onto the primary preform. Finally, a primary preform may comprise both the core and the cladding of an optical fibre, so that there is no need to apply an additional layer of glass. A primary preform is in that case identical to a final preform. A radial refractive index profile can be measured on a primary preform and/or on a final preform.
[0030] The length and diameter of a final preform determine the maximum length of optical fibre that can be obtained from the final preform.
[0031] To decrease the production costs of optical fibres and/or increase the output per primary preform, the object is to produce, on the basis of a final preform, a maximum length of optical fibre that meets the required quality standards.
[0032] The diameter of a final preform can be increased by applying a thicker layer of additional glass to a primary preform. Since the optical properties of an optical fibre are determined by the radial refractive index profile, the thickness of the layer of additional glass must at all times be in the correct proportion to the layer thickness of the preform layers of the primary preform that will form the core, more in particular the one or more concentric layers of the core in the optical fibre. Consequently, the layer thickness of the glass layer additionally applied to the primary preform is limited by the thickness of the preform layers being formed by means of the internal vapour deposition process.
[0033] The length of a final preform can be increased by increasing the length, more in particular the usable length, of a primary preform. The “usable length” is to be understood to be the length of the primary preform along which the optical properties remain within a predetermined tolerance limits, which tolerance limits have been selected so that optical fibres that meet the desired quality standards are obtained.
[0034] To determine the usable length of the primary preform, a radial refractive index profile is measured at a number of positions along the length thereof, after which it is possible, based on said measurements, to draw up a so-called longitudinal refractive index profile and a longitudinal geometry profile for each preform layer.
[0035] Thus a “longitudinal refractive index profile” is to be understood to be a graphic representation of the refractive index of a preform layer as a function of the longitudinal position in the primary preform.
[0036] A “longitudinal geometry profile” is to be understood to be a graphic representation of the thickness of a preform layer as a function of the longitudinal position in the primary preform.
[0037] One of the factors that adversely affect the usable length of a primary preform it is so-called “taper”. The term “taper” is to be understood to be a deviation of the optical and/or geometric properties of the primary preform in regions near the ends thereof. A distinction is made between optical taper and geometric taper.
[0038] Optical taper relates to refractive index deviations, whilst geometric taper relates to deviations of the layer thickness of the preform layer.
[0039] If a primary preform is built up of several preform layers, the optical and geometric taper of the preform layers may be different from each other.
BRIEF SUMMARY OF THE INVENTION
[0040] It is an object of the present invention to provide a method and a device for manufacturing a primary preform in which the optical taper can be influenced practically independently of the geometric paper.
[0041] Another object of the present invention is to provide a method and a device for manufacturing a primary preform in which deviations of the longitudinal refractive index profile from a desired refractive index profile are minimized.
[0042] Yet another object of the present invention is to provide a method and a device for manufacturing a primary preform in which the refractive index of a preform layer can be influenced along the length of a primary preform during the deposition process.
[0043] The present invention as described in the introduction is characterised in that the furnace comprises at least two temperature zones, wherein a temperature or temperature gradient in one temperature zone can be set independently of a temperature or temperature gradient in the other zone(s), in which connection a “temperature zone” is to be understood to be a zone in the longitudinal direction of the hollow glass substrate tube. The present invention thus in particular relates to temperature zones which extend along the length of the substrate tube. It will be understood that, seen in radial direction, there may also be temperature gradients, but such gradients must not be confused with the present temperature zones.
[0044] The present inventors have found that the temperature of the substrate tube during the internal vapour deposition process has an influence on the refractive index. The temperature of the hollow glass substrate tube is understood to be the temperature of the hollow glass substrate tube, including the already deposited glass layers and/or preform layers. The temperature of the substrate tube corresponds to the temperature or the temperature gradient of the temperature zone in which the respective part of the hollow glass substrate tube is located. The present inventors have surprisingly found that the temperature of the substrate tube during the deposition process is of importance for the efficiency with which dopants are incorporated in the deposited glass. It should be noted that according to the present invention the reaction zone, which moves back and forth along the length of the substrate tube, is to be regarded as a separate part of the furnace, which furnace surrounds the substrate tube in a stationary position. Within the framework of the present invention the furnace must not be confused with the reaction zone that is required for the deposition.
[0045] More particularly, but without wishing to be bound by this theory, the present inventors assume that a higher temperature of the hollow glass substrate tube during the deposition process causes one or more dopants, in particular germanium oxide, to evaporate, or that the efficiency with which one or more dopants, viz. germanium in the form of germanium oxide, are incorporated in the glass decreases as a result of a high temperature. It should furthermore be noted that the reaction zone which can be moved back and forth along the length of the substrate tube is of vital importance in effecting deposition of glass on the inner surface of the hollow substrate tube.
[0046] It has been found that by thus providing the furnace with temperature zones in accordance with the present invention it is possible to create a temperature profile along the length of the substrate tube, more particularly the deposition length, such that the temperature of the hollow glass substrate tube is set at mutually different values along the deposition length thereof. The “deposition length” is to be understood to be the distance between a reversal point located near the supply side and a reversal point located near the discharge side of the hollow substrate tube. The deposition length therefore corresponds to the part of the length of the hollow glass substrate tube where glass layers are deposited.
[0047] The aforesaid temperature profile makes it possible to influence the refractive index along the length of the substrate tube, and consequently it is possible to reduce deviations of the refractive index of the deposited glass from a desired value along the length of the substrate tube.
[0048] The present inventors have thus found that it is possible, using this method, to increase the usable length of the primary preform in comparison with the usable length of a primary preform that has been made while using a substantially constant furnace temperature.
[0049] The present inventors have also found that the optical taper can be reduced without this having a significant effect on the geometric taper.
[0050] Thus, one or more of the above objects are accomplished by using the method according to the present invention.
[0051] In another preferred embodiment the internal vapour deposition process is a PCVD process, in which the reaction zone is a plasma which preferably moves back and forth along the deposition length of the hollow substrate tube in step v) at a velocity ranging between 10 and 40 m/min, preferably between 15 and 25 m/min.
[0052] In a preferred embodiment, the glass-forming gases used in step iii) comprise one or more dopants, preferably germanium. Said dopants influence the refractive index of the deposited glass. The refractive index of the deposited glass can be influenced by using dopants. Examples of dopants that increase the refractive index are germanium, phosphorus, titanium and aluminium, or the oxides thereof. Examples of dopants that decrease the refractive index are boron or the oxide thereof and fluorine. Preferably, germanium is used as a refractive index-increasing dopant and fluorine is used as a refractive index-decreasing dopant. In a special embodiment, a combination of germanium and fluorine is used as a dopant.
[0053] In another special embodiment of the method according to the present invention, the furnace comprises at least three temperature zones, which temperature zones each surround 5-20% of the deposition length near the supply side and the discharge side of the substrate tube. In the embodiment in which the deposition length is 1200 mm, the length of the temperature zones near the supply side and the discharge side of the substrate tube is 60-240 mm, therefore.
[0054] A furnace which comprises three or more temperature zones makes it possible to set the temperature of the substrate tube independently along the deposition length near the supply side, near the discharge side and the part of the deposition length therebetween. Thus, the optical taper near the supply side and the optical taper near the discharge side can be influenced independently of each other.
[0055] In another special embodiment, the furnace comprises at least four temperature zones, wherein a temperature or temperature gradient in one zone can be set independently of a temperature or temperature gradient in the other zone(s). In such an embodiment it is possible not only to influence the temperature of the substrate tube along the deposition length thereof near the supply side and the discharge side of the substrate tube, but also to divide the temperature in the region therebetween into at least two temperature zones and to set the temperature in said temperature zones independently of another temperature zone.
[0056] In a special embodiment of the method according to the invention, the maximum temperature difference between one temperature zone and another temperature zone is greater than 50° C.
[0057] In yet another special embodiment of the method according to the present invention, several preform layers are formed in step v) and the temperature or the temperature gradient in the temperature zones during the formation of one preform layer can be set independently of the temperature or the temperature gradient in the temperature zones during the formation of the one or more other preform layers.
[0058] This embodiment makes it possible to set an optimum temperature profile along the deposition length of the hollow glass substrate tube for each preform layer in situations where preform layers with mutually different dopant levels are used.
[0059] The present invention further relates to a device for manufacturing a primary preform for optical fibres, using an internal vapour deposition process in a hollow glass substrate tube having a supply side and a discharge side, which device comprises
[0060] i) a gas inlet and a gas outlet, between which the hollow glass substrate tube can be mounted,
[0061] ii) a furnace which surrounds the hollow glass substrate tube at least along a deposition length thereof,
[0062] iii) means for creating a reaction zone inside the hollow glass substrate tube, which means are disposed in the furnace during the deposition process and which can be moved back and forth between the reversal point located near the supply side and the reversal point located near the discharge side of the hollow glass substrate tube, characterised in that the furnace comprises at least two temperature zones, wherein a temperature or temperature gradient in one temperature zone can be set independently of a temperature or temperature gradient in the other zone(s).
[0063] In a preferred embodiment, the means for creating a reaction zone comprise a resonator which is capable of coupling microwaves into the interior of the hollow glass substrate tube so as to create a reaction zone in the form of a plasma.
[0064] In yet another preferred embodiment, the furnace comprises three or more temperature zones, which temperature zones each surround 5-20% of the deposition length near the supply side and the discharge side of the substrate tube.
BRIEF DESCRIPTION OF THE FIGURES
[0065] The present invention will now be explained in more detail by means of an example with reference to a number of figures, in which connection it should be noted, however, that the present invention is by no means limited thereto.
[0066] FIG. 1 is a schematic view of a device for carrying out an internal deposition process.
[0067] FIG. 2 is a schematic, perspective view of a device for carrying out an internal deposition process in accordance with the present invention.
[0068] FIG. 3 is a representation of a longitudinal refractive index profile in a primary preform.
[0069] FIG. 4 is a representation of a temperature profile in a furnace.
[0070] FIG. 5 is a representation of a corrected longitudinal refractive index profile.
DETAILED DESCRIPTION OF THE INVENTION
[0071] In FIG. 1 a device 100 for carrying out an internal vapour deposition process for the manufacture of a primary preform for optical fibres is schematically shown. The device 100 comprises a furnace 1 , which surrounds at least the deposition length 5 of a hollow glass substrate tube 2 .
[0072] The deposition length 5 corresponds to the part of the length of the hollow glass substrate tube 2 where glass layers are deposited. In other words, the deposition length 5 corresponds to the distance between the reversal point 11 located near the supply side and the reversal point 12 located near the discharge side of the hollow substrate tube. The reversal point is to be understood to be a position in the longitudinal direction of the hollow glass substrate tube 2 where the direction of movement of the reaction zone 6 is reversed in the opposite direction.
[0073] The furnace 1 surrounds the deposition length 5 during the deposition process, viz. at least during step v). After completion of the deposition process, the substrate tube 2 is removed from the furnace 1 and further processed.
[0074] The hollow glass substrate tube 2 has a supply side 3 and a discharge side 4 . The supply side 3 and the discharge side 4 can be positioned between a gas inlet and a gas outlet, respectively (not shown). The supply side 3 and the discharge side 4 may be clamped down thereon via a cylindrical passage provided with an O-ring seal, so that the internal volume of the hollow glass substrate tube 2 is isolated from the outside atmosphere. Such a construction makes it possible to carry out the deposition process at a reduced pressure when a pump (not shown) is connected to the gas outlet.
[0075] The aforesaid cylindrical passage may also be used in a rotary embodiment, so that the substrate tube can be rotated continuously or in steps during the deposition process.
[0076] During the vapour deposition process a reaction zone 6 moves back and forth along the length of the hollow glass substrate tube 2 between a reversal point 11 located near the supply side 3 and a reversal point 12 located near the discharge side 4 , which length is also referred to as the deposition length 5 , inside the hollow glass substrate tube 2 so as to form glass layers. The width 7 of the reaction zone 6 is smaller than the deposition length 5 . The present invention is in particular suitable for use in a PCVD-type deposition process, in which the reaction zone is a low-pressure plasma. The term “low pressure” is understood to mean that the plasma is created at a pressure of about 1-20 mbar in the substrate tube.
[0077] While glass-forming gases, which may or may not be doped, are being supplied to the supply side 3 of the hollow glass substrate tube 2 , glass layers (not shown) are deposited along the deposition length 5 on the inner surface of the hollow glass substrate tube 2 .
[0078] A number of glass layers deposited using a more or less constant composition of the glass-forming gases being supplied on the supply side 3 thus form a preform layer.
[0079] It is also possible to form a preform layer by using a predetermined variation in the composition of the glass-forming gases. Such a preform layer is for example used for manufacturing a primary preform for gradient index type optical fibres.
[0080] After completion of the deposition process, the substrate tube 2 with the preform layer/layers deposited therein can be consolidated into a solid rod by means of a contraction process, also referred to as a collapse process.
[0081] Means for creating a reaction zone inside the hollow glass substrate tube 2 preferably comprise a resonator, as known for example from the U.S. patent applications published under Nos. US 2007/0289532, US 2003/0159781 and US 2005/0172902. U.S. Pat. Nos. 4,844,007, 4,714,589, 4,877,938. Such resonators enclose the substrate tube 2 and are moved back and forth along the deposition length during the deposition process.
[0082] FIG. 2 is a perspective view of a special embodiment of the device 100 , in which three temperature zones 8 , 9 and 10 are schematically shown. The temperature zones 8 , 9 and 10 can for example be created by disposing individually controllable heating elements (not shown) in the furnace 1 at various positions in the longitudinal direction of the substrate tube. Carbon elements, for example, are suitable heating elements. The present invention is not limited to carbon elements, however. In principle, heating elements capable of reaching a maximum temperature of about 1400° C. are suitable. The width of the temperature zones can be set as needed and is not necessarily the same for each temperature zone. To achieve a precise setting of the temperature of the substrate tube in longitudinal direction, it may be desirable to realise temperature zones of mutually different length.
[0083] The temperature zones 8 , 9 , 10 may be separated from each other by one or more separating elements (not shown) made of an insulating material, for example aluminium oxide. The use of insulating separating elements makes it possible the maintain a constant temperature of the substrate tube 2 in a temperature zone. The absence of insulating separating elements will lead to variations in the temperature of the substrate tube 2 , in particular near the transition(s) between the adjacent temperature zone(s). Although FIG. 2 shows a furnace comprising three temperature zones 8 , 9 and 10 , the present invention is by no means limited to such an embodiment.
COMPARATIVE EXAMPLE
[0084] A step-index type primary preform comprising one preform layer is produced, using a prior art plasma chemical vapour deposition process (PCVD), in which the temperature in the furnace 1 is maintained at a substantially constant value along the length of the hollow glass substrate tube and in which germanium is used as a dopant so as to obtain a desired refractive index difference of 0.335%. Upon completion of the vapour deposition process, the resulting hollow glass substrate tube 2 is consolidated into a primary preform, after which the radial refractive index profile is measured at a number of positions along the length of the primary preform, using a so-called “preform analyzer”, for example a “2600 Preform Analyser”, which is commercially available from Photon Kinetics. Subsequently, a longitudinal refractive index is determined for the preform layer in the primary preform on the basis of the obtained radial refractive index profiles. In this way a longitudinal refractive index profile as shown in FIG. 3 is obtained. The refractive index difference, Delta% (Δ%), is shown on the vertical axis, and the position in the longitudinal direction of the primary preform is shown on the horizontal axis. The aimed-at or desired value, represented by means of the broken horizontal line, for Δ i % is 0.335%.
[0085] FIG. 3 clearly shows that the obtained value for Δ% deviates from the desired value along the length of the primary preform.
[0086] In particular the deviation at the ends of the primary preform (corresponding to the left and at right-hand side of FIG. 3 ) leads to a significant reduction of the usable length of the primary preform.
EXAMPLE
[0087] Based on the longitudinal refractive index profile shown in FIG. 3 , a (longitudinal) temperature profile is subsequently determined for the furnace 1 , using a computer model, which temperature profile is used to reduce the deviations of the refractive index (expressed as Δ%) from a desired value, which is 0.335% in the present example.
[0088] The thus determined temperature profile is shown in FIG. 4 , in which the furnace temperature is shown on the vertical axis and the position in the primary preform is shown on the horizontal axis. The position in the primary preform shown in FIG. 3 corresponds to the position of the hollow glass substrate tube 2 in FIG. 4 .
[0089] The vertical full lines in FIG. 4 correspond to the six temperature zones Z 1 -Z 6 . Thus, temperature zone Z 2 starts at a position of 160 mm and ends at a position of 310 mm, zone Z 3 starts at a position of 310 mm and ends at a position of 575 mm, etc. It is noted that the present invention is not limited to an embodiment comprising six temperature zones.
[0090] It is further noted that the temperature zones are not separated by insulating partitions, so that a more or less smooth temperature transition occurs between adjacent temperature zones.
[0091] From FIG. 3 it can be derived, for example, that the refractive index difference is lower than the desired value (0.335%) in the larger part of the temperature zone Z 3 , whilst in the larger part of the temperature zone Z 4 , on the other hand, the refractive index difference is higher than the desired value. Based on these results it is desirable for the temperature in the respective temperature zones Z 3 and Z 4 to be set so that the above deviation is reduced.
[0092] Thus it is possible, based on the temperature profile shown in FIG. 4 , to manufacture a preform having a longitudinal refractive index profile corresponding to the longitudinal refractive index profile shown in FIG. 5 . The refractive index difference, Δ%, is shown on the vertical axis in FIG. 5 and the position in the longitudinal direction of the primary preform is shown on the horizontal axis.
[0093] It is quite apparent that in comparison with the deviations shown in FIG. 3 , the deviations of the Δ% are significantly reduced in relation to the set value of 0.335% along substantially the entire length of the primary preform.
[0094] In particular FIG. 5 shows that the deviation of the refractive index difference at the ends of the primary preform has been significantly reduced. The methods and the device according to the present invention thus make it possible to increase the usable length of a primary preform. | A method for manufacturing a primary preform for optical fibres using an internal vapour deposition process including the steps of providing a substrate tube having supply and discharge sides, surrounding at least part of the tube by a furnace, supplying glass-forming gases to the interior of the tube via the supply side, creating a reaction zone with conditions such that deposition of glass will take place on the inner surface of the tube, and moving the reaction zone back and forth along the length of the tube between reversal points near the supply and discharge sides to form one or more preform layers on the inner surface of the tube, wherein both reversal points are surrounded by the furnace. | 8 |
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 61/599,367, filed on Feb. 15, 2012, the entire teachings of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Question answering systems provide companies (e.g., customers of the question answering service) an ability to have a computer operated system provide automated support to an end-user (e.g., a customer of the company). This allows for the company to provide service to the end-user 24 hours a day, seven days a week. Question answering systems also reduce labor costs by reserving employees for more difficult questions from the end-user.
SUMMARY OF THE INVENTION
[0003] In one embodiment, a method of customizing a question answering system can include searching a plurality of articles, based on a user query from a user, received via a computer network. The method can further include delivering a set of articles, based on the searching, to the user via the computer network. The method can additionally include receiving user feedback on the set of articles from the user via the computer network. The method can also include associating a given article from among the set of articles with the user query based on the user feedback.
[0004] In another embodiment, the user feedback can be based on at least one of the following activities performed by the user: (a) selecting an article of the plurality of articles, (b) spending time viewing the article, (c) scrolling through the article, (d) leaving the article within a given time period after viewing the article, (e) selecting a second article, (f) making a manual user entry, or (g) returning to a previously selected article.
[0005] In another embodiment, the method can further include applying a corresponding score to each article within the set of articles based on the user feedback.
[0006] In yet another embodiment, the method can additionally include clustering user queries based on a linguistic distance being below a particular threshold. The method can further include associating a first cluster and second cluster based on a common association with the same article. The method can additionally include presenting a representation of the clusters of user queries to a user and enabling the user to modify the cluster. Modifying the cluster can include performing at least one of the following operations: (a) mapping the cluster to a particular article, (b) creating a new article associated with the cluster, (c) deleting an article associated with the cluster, (d) connecting the cluster to a secondary user query, the secondary user query clarifying the user queries of the cluster, (e) merging a first article and a second article associated with the cluster to be one search result, (f) splitting an article associated with the cluster into a first article and a second article associated with the cluster, or (g) rewriting an article associated with the cluster. The method can also include authorizing a user to modify the cluster.
[0007] In another embodiment, the method can include presenting a dialog mode to a user. The method can also include receiving a natural language query from a user and presenting a natural language answer to the user. The natural language answer can be an article associated with a cluster. The method can further include, if more information is needed, presenting a second natural language query to the user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
[0009] FIG. 1A is a block diagram illustrating an example embodiment of an Intelligent Virtual Agent (IVA).
[0010] FIG. 1B is a block diagram of the IVA operatively coupled to a user device over the network.
[0011] FIG. 1C is a block diagram illustrating an example embodiment of the IVA employed in a dialog mode.
[0012] FIG. 2 is a flow diagram illustrating an example embodiment of training the IVA.
[0013] FIG. 3A is a block diagram illustrating an example embodiment of the IVA in an encapsulated search mode.
[0014] FIG. 3B is a block diagram illustrating an example embodiment of the IVA employed in dialog mode.
[0015] FIG. 4A is a flow diagram illustrating an example embodiment of the IVA employed in encapsulated search mode.
[0016] FIG. 4B is a flow diagram illustrating an example embodiment of dialog mode employed by the IVA.
[0017] FIG. 5 is a block diagram illustrating an example embodiment of clusters mapping to a knowledge base.
[0018] FIG. 6 illustrates a computer network or similar digital processing environment in which the present invention may be implemented.
[0019] FIG. 7 is a diagram of the internal structure of a computer (e.g., client processor/device or server computers) in the computer system of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0020] A description of example embodiments of the invention follows.
[0021] The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety.
[0022] FIG. 1A is a block diagram 100 illustrating an example embodiment of an Intelligent Virtual Agent (IVA) 102 . An IVA is an automated question answering system deployed by a customer (e.g., a company) that receives queries from an end-user (e.g., a client of the customer). IVAs can require a large amount of work from a vendor (e.g., a company implementing the IVA) and the customer (e.g., a company purchasing the IVA service to solve a problem, such as support, sales or marketing). In the foregoing description, customer refers to the party running the IVA, vendor refers to the party building the IVA, and end-user refers to the client of the customer that is using the IVA for support.
[0023] Quality of an IVA is linked to the quality and amount of configuration of the IVA. An IVA should issue quality answers with a precise scope with a clean content architecture. Configuring the IVA to meet these requirements bridges the gap between intent of end-user queries issued to the IVA and the content of the customer. The proposed method and corresponding system configures an IVA with a customer's knowledge base without a huge investment of time before deploying the IVA.
[0024] An administrative user 108 employs a setup device 106 to configure the IVA 102 . The setup device 106 is operatively coupled to the IVA 100 over a network 104 . The administrative user 108 employs the setup device 106 to send initialization information 102 to the IVA 102 . The initialization information 110 includes a name of the agent 112 , an avatar 114 , and a knowledge base 116 .
[0025] The name of the agent 112 is a name shown to end-users when conversing with the IVA 102 . Likewise, the avatar 114 is a picture, such as an image of a human face or a cartoon of a human face, shown to the end-user while communicating with the IVA 102 . The knowledge base 116 is a collection of articles from the customer that can be provided as answers to user queries.
[0026] FIG. 1B is a block diagram 120 of the IVA 102 operatively coupled to a user device 124 over the network 104 . An end-user 122 enters a query into the user device 124 that is forwarded over the network 104 to the IVA 102 . The IVA processes the query 126 by performing a search engine search of the knowledge base and delivering search engine results 128 to the user device 124 over the network 104 . The user device 124 shows the search engine results 128 to the end-user 122 . The end-user 122 , after interacting with the search engine results 128 , sends feedback 130 on the articles in the search engine results to the IVA 122 . The IVA 102 then updates mapping of queries to articles in the knowledge base based on the feedback 130 . Feedback 130 can include metrics such as the end-user 122 selecting (e.g., clicking on) an article, the end-user 122 leaving an article and selecting another article, the end-user 122 manually entering positive or negative feedback about an article, time spent viewing an article, scrolling within an article, or returning to a previously viewed article.
[0027] FIG. 1C is a block diagram 140 illustrating an example embodiment of the IVA 102 employed in a dialog mode. The IVA 112 in dialog mode maps queries directly to articles, instead of performing a search engine search on the knowledgebase. For example, the end-user 122 enters a query 126 into the user device 124 . The IVA 102 , upon receiving the query 126 , instead of performing a search engine search, directly maps the query 126 in an article or a set of articles, and delivers result(s) based on clusters 142 to the user device 124 . Likewise, the user device then delivers feedback 144 on articles in the results, similar to the feedback 130 described in FIG. 1B .
[0028] FIG. 2 is a flow diagram 200 illustrating an example embodiment of training the IVA. Training begins by beginning configuration ( 202 ). Then, the user uploads a knowledge base to the IVA ( 204 ). Then, the user can optionally upload an avatar and a corresponding name to the IVA ( 206 ). Then, the configuration is complete and the user can start the IVA for interaction with end-users ( 208 ).
[0029] In one embodiment, the IVA begins with a database of the customer's content “as is.” The customer is able to create and educate the IVA without help from the vendor. Content can include answers taken from frequently asked questions (FAQs), resolution cards, solutions, etc. The customer's content “as is” is known to be bad, and embodiments of the systems and methods disclosed herein aim to improve the content in the database. The IVA provides a search experience to end-users using the database of the customer content “as is.” The IVA monitors behavior and final satisfaction of end-users, and modifies the database accordingly to improve future IVA performance.
[0030] In one embodiment, the IVA described herein can be deployed on its host website and exposed to users as soon as the IVA is created. The customer organization is able to immediately provide its users with an IVA user interface (UI) (e.g., a chat window) on its website by adding code (e.g., JavaScript, HTML5, etc.). IVA creation, from the customer perspective, includes selecting a name for the IVA, an avatar for the IVA, and linking the system to its knowledge base. In other embodiments, the IVA can be created without a name and/or avatar.
[0031] FIG. 3A is a block diagram 300 illustrating an example embodiment of the IVA in an encapsulated search mode. A search engine module 304 within the IVA receives a user query 302 . The search engine module 304 performs a search of the knowledge base, based on the words in the user query 302 , and delivers a presentation to the user 306 . The presentation to the user 306 can include a set of articles that are most closely related to the user query 302 based on the words in the user query 302 .
[0032] Upon deployment, the IVA is in encapsulated search mode, using a search engine on the customer's knowledge base to provide its response to end-user queries. At this point, the IVA relies on no other data to provide its responses to the query other than words within the customer's knowledge base. In encapsulated search mode, the behavior of the end-user using the UI of the IVA is recorded. The IVA records the queries of the user, the articles/links the user chooses to click, the time the user spends on each linked page, the user's satisfaction, either self-reported by use of thumbs up and thumbs down buttons or by implication. Implied user satisfaction can be measured by a user's leaving an article, or by retaining knowledge of the last article a user visits.
[0033] The IVA, during the encapsulated search phase, sends every user input to its search engine which responds with a series of possible articles. The IVA presents selected top ranked articles to the user as potential responses. The IVA also adds links between the user query and the selected articles with a neutral grade. If an article is already linked with the query, the grade of the article in the IVA system does not change. The IVA links user queries to knowledge base articles (or other answers) based on the grades. The IVA, in discovering the possible links between user queries and knowledge base articles, can then later ask the administrative user of the customer to confirm or reject the links/mapping.
[0034] For example, after the end-user enters query q 1 =“can I send a check?,” the IVA search engine returns four articles: a 123 , a 587 , a 745 and a 457 . At this point, grades of all the articles are zero, as indicated by the following equation (with L(q k ,a n ) being the grade of the link between q k and a n ):
[0000] L ( q 1 ,a 123 )= L ( q 1 ,a 587 )= L ( q 1 ,a 745 )= L ( q 1 ,a 457 )=0
[0035] From there, the IVA records end-user actions reacting to the presented articles. Each action can assign a number of points to the link between a query and an article (L(q k ,a n )). In one embodiment, an end-user's clicking a link adds five points to the grade between the article and the query. Similarly, an end-user's clicking a “thumbs up” adds 10 points to the grade, and the end-user's clicking a “thumbs down” subtracts 10 points from the grade. For example, if the end-user selects the first article (a 123 ), clicks on “thumbs down” for the same first article (a 123 ), returns to the search screen, click on third one and “thumbs up” and leave gives the following point totals for the links:
[0000] L ( q 1 ,a 123 )=−5
[0000] L ( q 1 ,a 587 )=0
[0000] L ( q 1 ,a 745 )=+15
[0000] L ( q 1 ,a 457 )=0
[0036] Other user input, such as scrolling the article, time spent on the article, or leaving the article, can also be recorded and modify the grade accordingly. The IVA monitors user input and adjusts the grades of the links for every end-user query.
[0037] FIG. 3B is a block diagram 350 illustrating example embodiment of the IVA employed in dialog mode. In dialog mode, a direct answer lookup module 352 receives the user query 32 . The direct answer lookup module 352 employs data in the IVA based on previously received user feedback to link the user query 302 directly to an article or a set of articles and delivers the articles in a presentation to the user 354 , if such a link is found. On the other hand, if the link is not found, the direct answer lookup module relays the user query to the search engine module 304 , which performs a search as described in FIG. 3A . In relation to FIG. 3B , the search engine module 304 then delivers the presentation 306 to the end-user as described in relation to FIG. 3A . This can be referred to as a “search fallback,” where. in the event that the IVA does not successfully find a helpful article for the end-user, the IVA can offer a search of the knowledge base/database based on the user query.
[0038] The IVA switches to dialog mode after a threshold of volume of traffic to the IVA. The IVA UI does not change from the perspective of the user in dialog mode. However, instead of querying the search engine to provide the responses, the IVA can map a user input directly to an intent and to a response or article. If the IVA cannot map the input to an intent, or if the IVA cannot map the intent to a response, then the IVA performs a search of the knowledge base, as described above. In the dialog mode, the behavior of the end-user continues to be recorded, as described above, in order to further refine the IVA's knowledge of the end-user's intents.
[0039] FIG. 4A is a flow diagram 400 illustrating example embodiment of the IVA employed in encapsulated search mode. First, the IVA begins the encapsulated search mode ( 402 ). The IVA receives a user query ( 404 ). Then, the IVA performs a search engine search of the knowledge base with the words in the user query ( 406 ). The IVA then presents the end-user with articles found from the search ( 408 ). The articles found in the search can be ranked according to matches with the words in the query or another metric. Then, the IVA receives user feedback on the search results ( 410 ). The IVA, based on the user feedback, adjusts scores of the articles in relation to the query received for future mapping of the query to each article in the search results. Then the IVA determines whether enough feedback has been received to deliver directly mapped answers to the user query ( 412 ).
[0040] If enough feedback has been received, the IVA begins dialog mode ( 414 ). Dialog mode is further described in relation to FIG. 4B . In relation to FIG. 4A , if the IVA determines that there is not enough feedback received to deliver directly mapped answers to the user ( 412 ). The IVA continues the encapsulated search mode ( 416 ), and then receives a subsequent user query ( 404 ).
[0041] FIG. 4B is a flow diagram 450 illustrating an example embodiment of dialog mode employed by the IVA. The IVA begins dialog mode ( 414 ) after the encapsulated search mode has been complete ( FIG. 4A ). In relation to FIG. 4B , the IVA then receives the user query ( 452 ). Then, the IVA determines whether there is a direct map of a query to an article ( 454 ). If there is a direct map to an article ( 454 ), then the IVA maps the query to the article or articles ( 456 ). Then, the IVA presents the articles to the end-user ( 458 ). The IVA receives user feedback on the search results to update the links further between queries and articles, even though encapsulated search mode is over ( 460 ). Then, the IVA receives another user query ( 452 ).
[0042] On the other hand, if there is no direct map of a query to an article ( 454 ), the IVA performs a search engine search of the knowledge base ( 462 ). Then, the IVA presents the articles to the end-user ( 458 ).
[0043] FIG. 5 is a block diagram 500 illustrating an example embodiment of clusters mapping to a knowledge base 508 . In the background, on a regular basis, the IVA reviews all the end-user queries it receives. The IVA clusters the queries by grouping them by their linguistic proximity. The IVA clusters end-user queries with the same meaning together. Clustering is further described in “Semantic Clustering” by Jean-Marie Larchavêque et al., filed as U.S. application Ser. No. 12/758,091 on Mar. 26, 2010 and “Semantic Clustering and Conversational Agents” by Jean-Marie Larchavêque et al., filed as U.S. application Ser. No. 12/748,2010 on Mar. 26, 2010, both of which are incorporated herein by reference in their entirety.
[0044] If d(q i ,q j ) is the linguistic distance between q i and q j and Q is the entire query space, linguistic clusters can be defined as follows:
[0000] ∀ qεQ,∃cCQ,∀ ( q 1 ,q 2 )ε c 2 ,d ( q 1 ,q 2 )<ε and qεc
[0045] The operation creates a set of disjoint clusters mapping the entire query space Q. The clusters can be assigned links to the articles, the grade of the links being a function of the grades of the links of the cluster's contained queries, as described by the following relationship.
[0000] Λ( c n ,a m )= f ( L ( q i ,a m ), q j εc n )
[0046] The above function accounts for links not existing exist between some queries in the cluster and a particular article. As a result, each cluster has a preferred article which is the article whose link has the highest grade, noted as a(c n ). The IVA, during the second pass of clustering, groups linguistic clusters that have the same preferred article. The clusters can also be referred to as intent.
[0000] C ( a k )={ q,qεc n and a ( c n )= a k }
[0047] Links and grades on the dual clusters are defined the same as links and grades for linguistic clusters. Although dual clusters can be defined by a preferred article, the clusters are linked to multiple lower ranked articles, and the Λ function (a→Λ(C,a)) is defined for the lower ranked articles in addition to the preferred article.
[0048] Dual approach clustering combines groups queries by both linguistic aspects of the query but also by the end-user's intent (as reflected by the grades of the links). Dual approach clustering combines two ways of ascertaining the meaning of an incoming query: (1) its local linguistic data, and (2) what the end-user previously indicated is an appropriate response.
[0049] A first cluster 502 , second cluster 504 , and third cluster 506 include a plurality of queries 516 a - e , 518 a - e , and 520 a - e . Each of the clusters 502 , 504 and 506 map to articles in the knowledge base 508 . For example, the first cluster 502 maps, via a mapping link 522 , to a second article 512 in the knowledge base 508 . The mapping link 522 is based on feedback of the queries 516 a - e within the first cluster 502 that indicate the second article 512 is most relevant to the topic of the queries 516 a - e stored in first cluster 502 .
[0050] Further, the third cluster 506 includes a mapping link 524 also to the second article 512 . The mapping link 524 , like the mapping link 522 , is based on the queries 520 a - e within the third cluster 506 . The IVA, based on the first cluster 502 and third cluster 506 both mapping to the second article 512 , can suggest to merge the first cluster 502 and third cluster 506 . The IVA suggests merging the first cluster 502 and third clustering 506 because the respective queries 516 a - e and 520 a - e of both clusters indicates that the second article 512 is an answer to both. This implies that the first cluster 502 and the queries 516 a - e therein and the third cluster 506 and the queries 520 a - e therein includes similar queries that may be simply worded differently and not graded same by a linguistic search, but are about the same content.
[0051] The second cluster 504 , which includes queries 518 a - e , is mapped to a third article 514 via mapping link 526 . The second cluster 504 is not a candidate for merging because no other cluster maps to the same third article 514 . The knowledge base 508 also includes first article 510 to which no cluster has a mapping link.
[0052] Each cluster 502 , 504 and 506 can map to multiple articles in addition to mapping to one article. A cluster mapping to one article is shown in FIG. 5 for simplicity. Each cluster can map to multiple articles, having a top-ranked article and other lower-ranked articles to display to the user. Further, a cluster can map to no article if the queries have not indicated to which article the queries map.
[0053] Further, the IVA can issue other suggestions to the customer to improve the end-user experience. For example, the IVA can suggest that the customer improve content by creating or deleting answers. The IVA can further suggest creating refining questions to hone in on an end-user query. The IVA can also map intents of a query directly to a known solution. The IVA can additionally offer suggestions to the organization, such as the rewriting of an article, merging of two similar articles (as described above), and splitting of an answer into two different articles.
[0054] The IVA can include an administrative tool for the customer's use, which can prompt an administrative user of the customer to take one or more actions to improve the IVA's content. These actions are presented simply to the administrative user, for example, by requiring only one click to perform the action.
[0055] One action provided by the administrative tool is “Map.” The administrative tool presents the administrative user with a list of end-user inputs and a knowledge base article. The administrative tool asks the administrative user to enter whether each input on the list should trigger this article as a response.
[0056] The administrative tool can also ask the administrative user to merge two similar articles, split an article into two if queries with two or more different subjects commonly result in the same article, rewrite an article, create an article if a cluster is mapped to no article or no article with a rank above a certain threshold, or delete an article that is mapped to no cluster or has no rank for any cluster or query above a certain threshold.
[0057] The IVA can also detect the need for clarification between two articles. If two articles need clarification, the administrative tool can ask the administrative user to create a clarifying question to be presented to the user. The clarifying question should elicit the user's intent to discriminate between these two articles. Therefore, the IVA can evolve into more than a question answering system by being able to handle more complex dialog guided by detecting the need for clarification and adapting the dialog with the administrator-generated clarifying question.
[0058] In one embodiment, when the customer needs to take an action, the administrative tool presents example user inputs to the administrative user that the IVA detected before proposing the action. This presents the decision for the administrative user as whether the administrative wants the IVA responding to the user query as shown, as opposed to making decisions abstractly. For example, the administrative tool can ask the administrative user to determine whether “Question A” should map to “Article X,” and the administrative user can answer with a “yes” or “no.”
[0059] As soon as the IVA has initiated dual clustering, the IVA reviews the clusters and their respective links to articles to propose enhancement in the knowledge of the agent to the customer. For every cluster C, the IVA employs the A function (a→Λ(C,a)), and the distribution of its results are the signals to select which (if any) suggestion to make. A good solution for a cluster C and a corresponding article a is determined if its grade Λ(C,a) is greater than a threshold (t), where G c is the set of the good solutions for cluster C.
[0000] G c ={a,Λ ( C,a )< t}
[0060] Let also /G c / be the cardinal (i.e., indicate the number of articles it contains) of this set.
[0000]
Suggestions
Conditions to trigger suggestion
Map
Connect a cluster to
/G c / = 1
an article.
Create
Write a new article.
C ≠ and /G c / = 0
Delete
Delete a useless
C (a) =
article.
Clarify
Connect a cluster to
1 < /G c / < 4
a clarifying question.
Merge
Merge two articles.
1 < /G c / < 4
Split
Split one article into
C(a) is composed of at least two linguistic
two new articles.
clusters that are too distant from each other.
Rewrite
Rewrite an article.
C(a) is composed of at least two linguistic
clusters that are too distant from each other.
[0061] The IVA annotates links between clusters of queries and articles based on the actions taken by the customer. The IVA then uses those annotations in dialog mode. Once enough of the query space is mapped to articles or clarifying questions the agent can be switched into dialog mode. In this mode, when a user inputs a query, the IVA attempts to determine to which cluster C the end-user's query belongs. There are three possibilities:
1) The IVA finds a cluster and the cluster is mapped to an article or a clarifying question, and the IVA responds the article or clarifying question. If the user is not happy with the provided response, the user has the option of using the search engine, for example, via a “see more answers button.” 2) The IVA finds a cluster that is not mapped to an article or clarifying question. The IVA responds with articles contained in G c . 3) The IVA cannot find a cluster, so the IVA employs the search engine to find an article.
[0065] In this mode, the IVA continues to employ behavior monitoring, clustering and guided evolution in the background so that the IVA is continuously improved.
[0066] FIG. 6 illustrates a computer network or similar digital processing environment in which the present invention may be implemented.
[0067] Client computer(s)/devices 50 and server computer(s) 60 provide processing, storage, and input/output devices executing application programs and the like. Client computer(s)/devices 50 can also be linked through communications network 70 to other computing devices, including other client devices/processes 50 and server computer(s) 60 . Communications network 70 can be part of a remote access network, a global network (e.g., the Internet), a worldwide collection of computers, Local area or Wide area networks, and gateways that currently use respective protocols (TCP/IP, Bluetooth, etc.) to communicate with one another. Other electronic device/computer network architectures are suitable.
[0068] FIG. 7 is a diagram of the internal structure of a computer (e.g., client processor/device 50 or server computers 60 ) in the computer system of FIG. 6 . Each computer 50 , 60 contains system bus 79 , where a bus is a set of hardware lines used for data transfer among the components of a computer or processing system. Bus 79 is essentially a shared conduit that connects different elements of a computer system (e.g., processor, disk storage, memory, input/output ports, network ports, etc.) that enables the transfer of information between the elements. Attached to system bus 79 is I/O device interface 82 for connecting various input and output devices (e.g., keyboard, mouse, displays, printers, speakers, etc.) to the computer 50 , 60 . Network interface 86 allows the computer to connect to various other devices attached to a network (e.g., network 70 of FIG. 6 ). Memory 90 provides volatile storage for computer software instructions 92 and data 94 used to implement an embodiment of the present invention (e.g., IVA implementing code detailed above). Disk storage 95 provides non-volatile storage for computer software instructions 92 and data 94 used to implement an embodiment of the present invention. Central processor unit 84 is also attached to system bus 79 and provides for the execution of computer instructions.
[0069] In one embodiment, the processor routines 92 and data 94 are a computer program product (generally referenced 92 ), including a computer readable medium (e.g., a removable storage medium such as one or more DVD-ROM's, CD-ROM's, diskettes, tapes, etc.) that provides at least a portion of the software instructions for the invention system. Computer program product 92 can be installed by any suitable software installation procedure, as is well known in the art. In another embodiment, at least a portion of the software instructions may also be downloaded over a cable, communication and/or wireless connection. In other embodiments, the invention programs are a computer program propagated signal product 107 embodied on a propagated signal on a propagation medium (e.g., a radio wave, an infrared wave, a laser wave, a sound wave, or an electrical wave propagated over a global network such as the Internet, or other network(s)). Such carrier medium or signals provide at least a portion of the software instructions for the present invention routines/program 92 .
[0070] In alternate embodiments, the propagated signal is an analog carrier wave or digital signal carried on the propagated medium. For example, the propagated signal may be a digitized signal propagated over a global network (e.g., the Internet), a telecommunications network, or other network. In one embodiment, the propagated signal is a signal that is transmitted over the propagation medium over a period of time, such as the instructions for a software application sent in packets over a network over a period of milliseconds, seconds, minutes, or longer. In another embodiment, the computer readable medium of computer program product 92 is a propagation medium that the computer system 50 may receive and read, such as by receiving the propagation medium and identifying a propagated signal embodied in the propagation medium, as described above for computer program propagated signal product.
[0071] Generally speaking, the term “carrier medium” or transient carrier encompasses the foregoing transient signals, propagated signals, propagated medium, storage medium and the like.
[0072] While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. | Question Answering systems can be costly and time-consuming to configure for a particular knowledge base. The proposed Question Answering receives an initial knowledge base, receives user queries without any further configuration, and self-configures based on user feedback. In one embodiment, a method of customizing a question answering system can include searching a plurality of articles based on a user query from a user received via a computer network. The method can further include delivering a set of articles, based on the searching, to the user via the computer network. The method can additionally include receiving user feedback on the set of articles from the user via the computer network. The method can also include associating a given article from among the set of articles with the user query based on the user feedback. In this manner, the proposed question answering system saves the customer resources otherwise spent on configuration. | 6 |
CROSS-REFERENCE TO RELATED CASES
This is a continuation of application Ser. No. 963,603, filed Nov. 24, 1978, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to gas-fueled ovens and particularly to built-in wall ovens having pyrolytic self-cleaning capability. Built-in wall ovens of conventional construction have been manufactured in a manner such that insufficient heat will escape to damage adjacent surfaces of the walls or other enclosing and supporting structures. However, such ovens were adapted to be operated at normal baking and broiling temperatures which generally did not exceed 500°-550° F. Accordingly, it has been a relatively simple matter to sufficiently insulate the oven so that damage to adjacent structure would not occur.
However, heretofore it has not been practical to provide built-in wall ovens with pyrolytic self-clean capability because pyrolytic self-clean ovens are operated during a cleaning cycle at temperatures which may reach as high as 900°-1100° F. In such cases damage would easily be incurred by wall and supporting structure which encloses the ovens. It was found that such damage would occur as a result of the escape of high temperature heat particularly through the side and back walls and the floor of the ovens.
Attempts have been made to overcome this problem by providing flues along the back, sides and bottom of the oven to permit flow of cooling air which will keep the temperature of the surfaces below the danger point. While this did aid in maintaining the temperatures at safe levels when the ovens were used for baking and broiling operations, there arose an additional problem which came about when it was found that gas pilot burners tended to become extinguished, and the main burners were either partly or completely extinguished with the resultant danger of production of excessive amounts of CO and CO 2 .
SUMMARY OF THE INVENTION
The above and other objections to prior art gas-fueled built-in wall ovens are overcome in the present invention wherein oven surfaces adjacent to surrounding walls of the enclosure are maintained at relatively cool and safe temperatures during operation of the ovens at pyrolytic temperatures. This is accomplished by employing at least one fan or blower with suitable ducting to circulate cooling air over oven surfaces which are located adjacent to walls and floor of the enclosure.
In accordance with this invention, the passageways or ducts and the entrance points for the cooling air supply are separated from those for the combustion air to the burners. Thus, the air drawn into the cooling flues by the fans or blowers will not diminish the air drawn into the burner compartments, allowing the burners to be supplied with combustion air unaffected by the flow of the cooling air.
In further accordance with this invention is the provision of a circulation system in an oven wherein the temperature of exhaust gases during a pyrolytic operation is reduced by mixing the exhausted cooling air with exhausted combustion products at their exit points. This is achieved by exhausting the hot combustion products through an opening which is located immediately below and between cooling air exhaust openings so that upon being exhausted the hot combustion air will, upon rising, almost immediately mix with the exhausted cooling air, thus reducing the overall temperature of the combustion air so that air of dangerously high temperature will not pass into the ambient atmosphere in the room.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objectives of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein:
FIG. 1 is an isometric view of a wall oven embodying the invention;
FIG. 2 is a vertical sectional view taken on a transverse plane immediately behind the front doors and panels and looking toward the rear of the oven; and
FIG. 3 is a vertical sectional view taken substantially along the line 3--3 of FIG. 2 looking in the direction of the arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawings wherein like characters of reference designate like parts throughout the several views, the present invention is illustrated as adapted to a domestic wall oven of the type which may be built into the wall of a kitchen of a home, for example. While the presently described invention is particularly suitable for wall-mounted installations, it is to be understood that it also can be used in the ovens of free-standing stoves or ranges and, therefore, this invention is not limited to the wall-mounted application.
In the present description, it is believed unnecessary to show and describe well-known and conventional parts such as gas manifold, mixing chambers, control valves, etc. since they do not in themselves constitute any part of the present invention. For the purpose of this disclosure, it is believed sufficient to point out that free-standing, or floor supported, ranges and wall-mounted installations both include a substantially box-like metal body 12 containing within it a substantially box-shaped metal liner 14 which defines an oven cooking cavity 16 or compartment. Liner 14 includes a rear wall 18, a top wall 20, a bottom wall 22, a front wall 24 and a pair of side walls 25. The interior surfaces of the liner 14 may be finished in any conventional manner such as, for example, by bearing a layer (not shown) of porcelain enamel of the glass-frit type. An opening 26 is provided in the front wall 24 of the liner 14 whereby the interior of the oven cooking cavity 16 is accessible from the body 12. A door 28 is mounted on the front of the body 12 by a suitable hinge structure (not shown) whereby the door is pivotally movable into open or closed relation with respect to the open front of the cavity 16. The door hinge and latching structures are not shown and do not constitute in themselves part of the present invention.
The liner top wall 20, rear wall 18 and side walls are enclosed by bolts 30 of fibrous glass or other insulating material which is intended to aid in confining heat as much as possible to the interior of the cavity 16 during operation of the oven. The door 28 is similarly filled with insulation and may or may not be provided with a heat-resistant transparent window structure 32. Below the oven cooking cavity is an air cavity 34 the top of which is defined by a transverse plate 35 or the like which serves as the oven floor 22. The back wall 18 of the oven cavity conveniently extends downwardly to form the back wall 36 of the air chamber 34. Oven cavity side walls 25 also project downwardly to form the side walls 38 of the air chamber 34. Back wall 36 and side walls 38 merge forwardly to form the bottom 40 of the air chamber 34.
A vertical rear wall 42 is spaced rearwardly from the rear wall 18 and insulation 30 of the oven liner 14 and from wall 36 of the air cavity 34, as shown best in FIG. 3, the wall 42 continuing forwardly above the oven cavity to form a top 44 and further extending beneath the air chamber bottom 40 to form a bottom or floor 46. Wall 34 also wraps itself around the sides of the body to form outer side walls 48. Thus there is formed a cooling air passageway or chamber 50 which extends completely around the back, top and sides of the liner 14, and around the air chamber or cavity 34.
The front wall 24 of the liner extends downwardly over the front of the air chamber 34 and is provided with an opening 52 for providing access to the air chamber. Opening 52 is normally covered by a door or removable panel 54.
At the upper end of the appliance above the oven cavity is a chamber 56 having a bottom wall 58 extending from the front wall 24 rearwardly above and spaced from the oven top wall 20 with its inner end terminating in spaced relation to rear wall 42 so that the passageway or chamber 50 is in open communication with the chamber 56. A front opening 60 provides access to the chamber 56 and is adapted to be covered by a control panel 62 details of which are not included herein.
A separate duct 64 extends within the described cooling air chamber 50 along the under side of the air chamber floor 40 and upwardly along the oven back wall 18. This duct 64 receives air at its lower end from a central opening 66 in wall 24 and supplies this air as combustion air to a broil burner 68. Burner 68 is located in the oven cavity 16 at the upper extremity thereof and is preferably of the type which is known as a radiant burner and which produces a broad sheet of flame or incandescence. One example of a radiant burner of a type suitable for use in the self-clean oven of the present invention is that disclosed in U.S. Pat. No. 3,122,197. Such a radiant burner 68 includes a burner head defining an open-sided cavity 69, and a mixing chamber such as a venturi 70 which has one end communicating with the burner cavity 69 and the other end adapted to receive gas from a pipe 72. The mixing chamber 70, for efficient and rapid combustion, is required to receive an ample supply of primary combustion air from duct 64. For example, ten parts of air to one part of gas is considered to be one satisfactory ratio in the case of natural gas. To insure an adequate supply of uncontaminated primary combustion air, the mixing chamber 70 is made in the nature of an oversized venturi and its outer end 74 is bell-shaped, as shown in FIG. 3. End 74 is considerably larger than and encircles the end of the outlet pipe 72 so that air from duct 64 can pass into the mixing chamber 70 along with the gas from pipe 72.
The pipe 72 is suitably connected through a control system (not shown) to a source of gaseous fuel. Duct 64 terminates at its upper end just above an opening 78 into which the end 74 of the mixing chamber 70 extends. The wall 76 of duct 64 adjacent the opening 66 is preferably slightly angled as shown in FIG. 3 so that the duct 64 and the cooling air chamber 50 both may share opening 66. A suitable igniter 79 is located adjacent the burner head 69 for ignition of the fuel at the surface of the burner.
A lower or bake burner 80 is located in a cavity 82 which lies between oven shelf 22 and the bottom wall 35. Burner 80 extends a substantial distance front to rear in the burner cavity 82 and is preferably of a conventional blue-flame type which includes a ported burner head 84 having a gas-receiving chamber for receiving gaseous fuel from a venturi or the like 86 which is suitably located in a pipe leading from the burner 80 so as to receive gas from a supply pipe 88 and to admixture the gas with air in the conventional and well-known manner. A suitable ignitor 89 is located adjacent the burner 80 so that jets of flame will be ignited at each of the ports in the head.
An opening 90 through the rear wall 18 and insulation 30 allows the venturi 86 to extend into the duct 64 so that primary combustion air can be admixed with gas in the venturi 86 so as to sustain combustion in the burner head 84. Beneath the burner 80 is another duct 92 which is fixed upon wall 35 parallel with the burner head 84. Rear wall 18 and insulation 30 are apertured as indicated at 94 so that the duct 92 may receive air from the duct 64, which air is allowed to pass upwardly from duct 92 through a series of openings 96 as secondary air for the burner.
It will be apparent that air which enters duct 64 through the central opening 66 will flow to the burners 80 and 68 by convection and by the inspirating effect provided by the burners. However, in accordance with this invention, cooling air is forcefully moved over the heated oven body entirely separate from the flow of combustion air. The cooling air is drawn through the openings 64 and the shared opening 66 into the portion of duct or passageway 50 which is at the bottom of the appliance. Openings 98 are provided in the bottom wall 40 of the air cavity 34 and one or more suction fans or blowers 100 are located in the air cavity 34 to forcefully draw cooling air through the openings 98 into the air cavity 34 and then force it out through additional opening 102 into the areas 50 at the sides and back of the appliance.
At the upper end of the appliance the cooling air, which has been somewhat heated by the heat within the oven, passes both beneath and above the wall 58 and exits through openings 104 in the front of the appliance. However, because of the relatively fast movement of the cooling air caused by the fans 100, the air exiting at openings 104 is not greatly heated.
During the operation of the burners 68 and 80 in normal bake and broil cycles, combustion products are allowed to escape from the oven 16 through an opening 106 in top wall 20 into a flue 108 which terminates at a separate opening or series of openings 110. When the oven is operated in the self-clean cycle, gaseous degradation products are removed by pyrolysis and also flow out through the flue 108. However, the opening 106 is located immediately above the radiant burner 68 so that the undesirable degradation products must pass through the burner flame, thus being incinerated and removed without the necessity for additional catalytic oxidizing units or the like.
It will be understood that the burners 68 and 80 may be operated individually and separately from one another for conventional baking and broiling operations. However, both burners are operated simultaneously for performing a self-cleaning operation, although one burner may be operated for a short time before the other at the start of a self-cleaning operation, and one or both burners may be intermittently operated or modulated during a self-cleaning cycle in order to maintain a required temperature level.
The presently described self-cleaning oven operates to quickly raise the temperature in the interior of the oven to approximately 1,040° F., for example, although this may vary slightly, and then the mean temperature levels off at about 985° F., for example. It has been found that self-cleaning occurs at a temperature which, for most cooking materials, is above about 750° F. It is known that with higher temperatures, shorter time periods are required for food soils to be removed by pyrolytic action. The upper temperature levels may be established in accordance with the particular design of the oven; that is, higher temperatures and shorter time cycles may be used if heavier insulation and fire protection are provided. However, it has been found that a leveling off temperature of about 985° F. can be maintained with a gas oven which is properly designed and insulated as disclosed herein and that the temperatures of the outer walls of the appliance and of the surrounding walls will not become undesirably heated. It is to be understood, therefore, that the temperature and time cycles set forth herein are exemplary only and may vary from range to range or with different oven and range constructions.
The presently described gas-fueled oven can be raised to a temperature of about from 1,000°-1,040° F. within about 25-35 minutes, for example. It reaches the self-cleaning temperature of 750° F. in about 10 minutes, then continues up to the 1,040° F. level in about an additional 10-15 minutes, finally leveling off at about 985° F. for about 55-65 minutes, at which time the oven has become completely cleaned. Then, the control system shuts off the flow of fuel to the burners, and the oven is allowed to cool. In about 15-20 minutes the oven temperature is low enough to permit the oven door to be opened. Thus, the presently described oven operates above about 750° F. to self-clean for above 70-80 minutes and performs almost its entire cleaning during a period of about 55-65 minutes when it is actually above a level of 950° F., although admittedly a slight amount of cleaning starts to occur when the oven is being initially raised from the 750° F. level to the 950° F. level, which process may take from about 10-15 minutes.
It has been discovered that the range of compounds of which food soils are composed may be decomposed or degraded by heat during the time interval of about 70-80 minutes when above about 750° F., which process will produce substantial amounts of gaseous degradation products.
In the heat-cleaning cycle, a sweep of cool ambient air proceeds upwardly through the air cavity 34 and thence through the passageways 50 at the sides and back of the appliance. Some cool air, however, will bypass the air chamber 34 and continue directly through the horizontal portion of the duct 50 at the bottom into the vertical portion at the back. However, in either case, the forcibly moved cooling air is always independent of the flow of combustion air to the burners.
When the hot combustion air exits from flue 108 via opening 110, it will rise and immediately mix with the cooling air coming out of the openings 104 and thereby will become cooled. This will thus prevent greatly heated air from being exhausted into the surrounding atmosphere.
From the foregoing, it will be apparent that all of the objectives of this invention have been achieved by the gaseous-fueled self-cleaning oven disclosed herein. It will be understood, however, that several modifications in the invention and its manner of use may be made by those skilled in the art without departing from the spirit of the invention as expressed in the accompanying claims. | A self-clean oven having means for passing cooling air over the heated walls of the oven and further having means for supplying combustion air by normal inspiration to the oven burners independently of the flow of cooling air, and having still further means for mixing hot combustion products exhausted from the interior of the oven with exhausted cooling air to prevent passage of excessively hot air into the atmosphere. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention is directed to a method of producing an electrical cable protecting material. In particular, the present invention is directed to a method of producing an olefin-type protecting material for electrical wires or cables.
[0003] 2. Description of Related Art
[0004] Polyvinyl chloride has been widely used as a coating material for electrical cables used in vehicles, owing to its excellent mechanical strength, the ease with which it can be extruded around an electric cable, and its excellent flexibility, colorability (e.g., paintability) and cost efficiency.
[0005] However, due to recent global environmental measures, manufacturers of vehicle parts, including coatings of electrical cables for automobiles, have started to use halogen-free olefin-type polymers, such as olefin-type thermoplastic elastomers, instead of polyvinyl chloride. In particular, such halogen-free polymers are used as a base material, which is supplemented with a halogen-type flame-retardant such as a bromine-type flame retardant. See, for example, JP-A-5-320439, JP-A-10-195254, P2000-86563A, P2000-290439A, P2001-6447A.
[0006] When extruding compositions containing such olefin-type polymers, the surface of the products tends to become rough due to melt fractures, when the extrusion temperature is low. As a result, the wear resistance of the products is considerably lowered. Conversely, when the extrusion temperature is too high, material distribution is unbalanced and cooling-down deformations occur, thereby considerably reducing the lower limit of wear resistance.
SUMMARY OF THE INVENTION
[0007] In view of these difficulties, it is an object of the present invention to provide a method for producing a protecting material for electrical cables used in wire harnesses and the like in vehicles. The resulting protecting material does not suffer from the problems mentioned above when, for example, producing tubes or sheets (ribbons) by extrusion.
[0008] Various exemplary embodiments of the method comprise the step of extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, at temperatures ranging from about 190° C. to about 250° C.
[0009] In some such exemplary embodiments, the extruding step comprises extruding the composition at temperatures ranging from about 200° C. to about 220° C.
[0010] In various exemplary embodiments, the above method further comprises the step of mixing and kneading an olefin-type polymer and suitable additives, thereby obtaining pellets of the olefin-type polymer composition, the pellets being then supplied to the extruding step.
[0011] In various exemplary embodiments, the above extruding step comprises extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, whose olefin-type polymer (or olefin moiety) has a JIS A hardness ranging from about 60 to about 95.
[0012] In various exemplary embodiments, the above extruding step comprises extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, whose olefin moiety has 2 to 6 carbon atoms.
[0013] In various exemplary embodiments, the extruding step comprises extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, whose olefin moiety is formed of propylene-ethylene-propylene copolymer.
[0014] In various exemplary embodiments, the above mixing and kneading step may comprise mixing and kneading, as the suitable additives, at least one agent selected from the group consisting of a bromine-type flame retardant, antimony trioxide, a heat stabilizer agent and a lubricant.
[0015] In some such exemplary embodiments, the mixing and kneading step may comprise mixing and kneading a bromine-type flame retardant in a proportion, such that the amount of bromine accounts for about 1 to about 10% by weight in the total amount of the olefin-type polymer composition.
[0016] In other exemplary embodiments, the mixing and kneading step may comprise mixing and kneading antimony trioxide in a proportion of at least about 0.5 parts by weight, relative to 100 parts by weight of olefin-type polymer.
[0017] In further exemplary embodiments, the mixing and kneading step may comprise mixing and kneading a heat stabilizer agent in a proportion of at least about 0.2 parts by weight, relative to 100 parts by weight of olefin-type polymer.
[0018] In still further exemplary embodiments, the mixing and kneading step may comprise mixing and kneading a lubricant in a proportion of at least about 0.2 parts by weight, relative to 100 parts by weight of olefin-type polymer.
[0019] The invention also relates to an electrical cable protecting material. In various exemplary embodiments, the material is prepared according to a method comprising the step of extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, at temperatures ranging from about 190° C. to about 250° C.
[0020] In some such exemplary embodiments, the above material is prepared according to a method comprising the step of extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, at temperatures ranging from about 200° C. to about 220° C.
[0021] The invention further relates to a tube or sheet made of an electrical cable protecting material. In various exemplary embodiments, the material is prepared according to a method comprising the step of extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, at temperatures ranging from about 190° C. to about 250° C.
[0022] In some such exemplary embodiments, the above material is prepared according to a method comprising the step of extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, at temperatures ranging from about 200° C. to about 220° C.
[0023] There is further provided a wire harness comprising a plurality of electrical cables, each electrical cable being coated with a tube or sheet made of an electrical cable protecting material. In various exemplary embodiments, the material is prepared according to a method comprising the step of extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, at temperatures ranging from about 190° C. to about 250° C.
[0024] In some such exemplary embodiments, the above material is prepared according to a method comprising the step of extruding an olefin-type polymer composition, such as an olefin-type thermoplastic elastomer composition, at temperatures ranging from about 200° C. to about 220° C.
[0025] These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Various exemplary embodiments of this invention will be described in detail, with reference to the following figures, wherein:
[0027] [0027]FIG. 1 is a schematic diagram showing a blade used for a scrape test; and
[0028] [0028]FIG. 2 is a schematic diagram showing the arrangement of the blade and a sample of olefin-type polymer composition, when a scrape test is carried out.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0029] Olefin-type thermoplastic elastomer compositions, as an example of olefin-type polymer compositions, can be prepared and characterized as described below.
[0030] An olefin-type thermoplastic elastomer of the invention can contain olefin as its main component (i.e. accounting for at least 50% by weight of a repeating unit). The olefin can have a JIS A hardness ranging typically from 60 to 95 and in some embodiments from 70 to 93. The JIS A hardness is measured by a Durometer Type A, according to the method defined in Japanese Industrial Standards (JIS) K 7215 (pages 434 to 438).
[0031] Olefins having 2 to 6 carbon atoms, and some embodiments from 2 to 4 carbon atoms, such as ethylene, propylene and butylene, can be used.
[0032] The olefin-type thermoplastic elastomer may be a homopolymer or a copolymer. Further, the type of copolymer to be used is not particularly limited. In various exemplary embodiments, a propylene-ethylene-propylene copolymer can be used.
[0033] Examples of commercially available olefin-type thermoplastic elastomers include, but are not limited to, Catalloy KS-353P, Catalloy KS-081P, Catalloy KS-021P manufactured by Montell SDK Sunrise, and PER T310E manufactured by Tokuyama.
[0034] The type of bromine-based flame retardant to be used is not particularly limited for the purpose of the present invention. Bromine-type flame-retardants used for resins and rubbers can also be used in the invention. Suitable bromine-containing compounds usable as flame retardants include, but are not limited to, derivatives of tetrabromo-bisphenol A.
[0035] Examples of commercially available flame retardants include, but are not limited to, Fire Guard 3100 manufactured by Teijin Chemicals, Ltd. (bromine atom contents: 68% by weight) and Flame Cut 121R manufactured by Tosoh Co. Ltd. (bromine atom contents: 67% by weight).
[0036] A bromine-type flame retardant can be added such that the amount of halogen varies from about 1 to about 10% by weight, and in some embodiments from about 1.2 to about 5% by weight, of the total weight of olefin-type thermoplastic elastomer composition.
[0037] In some cases, when the amount of bromine-type flame retardant is less than the above lower limit, the composition does not procure a sufficient flame retardant property. Conversely, in some cases when the amount of bromine-type flame retardant is higher than the above upper limit, the specific gravity of the composition becomes too high, thereby preventing weight reduction of the composition.
[0038] Antimony trioxide can be added in a proportion of at least about 0.5 parts by weight, in some embodiments at least about 1 part by weight, relative to 100 parts by weight of olefin-type thermoplastic elastomer.
[0039] In some cases, when the content of antimony trioxide is less than about 0.5 parts by weight, the compound is not endowed with a sufficient flame retardant property. Though the amount of antimony trioxide in the compositions according to this invention has no particular upper limit, when added in excess, the specific gravity of the resulting composition can become too high.
[0040] In order to improve the thermal stability of the olefin-type thermoplastic elastomer composition, a heat stabilizer agent (oxidation- and aging-preventing agent) can be added. Examples of such heat stabilizer agent include, but are not limited to, hindered phenol-type anti-aging agents, monophenol-type anti-oxidants, bisphenol-type anti-oxidants, trisphenol-type antioxidants, polyphenol-type antioxidants, thiobisphenol-type antioxidants and phosphorous ester-type anti-aging agents.
[0041] Commercially available examples of such products include, but are not limited to, Tominox TT (hindered phenol-type anti-aging agent manufactured by Yoshitomi Finechemical Co. Ltd), Nocrack 200 (monophenol-type anti-aging agent manufactured by Ouchi Shinko Chemical Industrial Co. Ltd), Nocrack NS-6 (bisphenol-type anti-aging agent manufactured by Ouchi Shinko Chemical Industrial Co. Ltd) and Nocrack 300 (thiobisphenol-type anti-aging agent manufactured by Ouchi Shinko Chemical Industrial Co. Ltd).
[0042] A heat stabilizer agent can be added in a proportion of at least about 0.2 parts by weight, in some embodiments at least about 0.5 parts by weight, relative to 100 parts by weight of the olefin-type thermoplastic elastomer.
[0043] A lubricant can also be added in the olefin-type thermoplastic elastomer composition of the invention in order to improve its moldability. Such lubricants include, but are not limited to, fatty acids, metal salts thereof, amides thereof and the like.
[0044] The lubricant can be added in a proportion of at least about 0.2 parts by weight, in some embodiments at least about 0.5 parts by weight, relative to 100 parts by weight of olefin-type thermoplastic elastomer.
[0045] Further, any known additive, which is commonly used in elastomer compositions for wire harness parts material, may be added to the olefin-type thermoplastic elastomer composition of the invention. Examples of such additives include, but are not limited to, any kind of colorant and charge-preventing agent. The amount of additive may be determined as a function of its type.
[0046] In the present invention, the components or additives mentioned above may be mixed and kneaded according to any known method and transformed into pellets by means of a pelletizer. The obtained pellets may be extruded so as to obtain a protecting material. Conditions for kneading and pelletizing are not particularly limited. The same conditions as in the prior art can be used.
[0047] According to the method of the present invention, a composition can be extruded at a temperature ranging from about 190° C. to about 250° C., and in some embodiments, from about 200° C. to about 220° C. By regulating the composition temperature within the above ranges, the viscosity of the composition can be adjusted to a suitable range. As a result, the extruded material forms a smoothly flowing surface, free from unbalanced material distribution. The protecting material thus produced has an improved wear resistance.
EXAMPLES
[0048] 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 may be practiced.
[0049] The compositions (E1 to E5) shown in Table 1 are prepared by mixing respective components in indicated amounts, and by kneading the components at a temperature of about 180° C. for about 10 minutes in a pressurized kneader (volume: 20 l). The compositions are then transformed into pellets using a pelletizer. The oxygen index (OI) of the pellets was measured according to JIS K 7201. Obtaining OI values allows for the evaluation of the flame-retarding properties of a composition. When OI is higher than 27, a composition is considered as good. The results of the OI evaluation are also shown in Table 1. Quantities are given in parts by weight, unless otherwise noted.
TABLE 1 Components E1 E2 E3 E4 E5 Olefin-Type 100 100 100 100 100 Thermoplastic Elastomer 1 Bromine-Type Flame 1.8 2.5 3 3.5 5 Retardant 2 Antimony Trioxide 3 0.9 1.3 1.5 1.8 2.5 Heat Stabilizer 1 1 1 1 1 Agent 4 Zinc Stearate 5 0.5 0.5 0.5 0.5 0.5 Calcium Stearate 5 0.5 0.5 0.5 0.5 0.5 Flame Retardaney 27 27.5 28 29 31 (OI) Halogen Content 1.2 1.6 1.9 2.2 3.1 (weight %)
[0050] The components of the Examples shown in Table 1 are mixed together in respective amounts, kneaded for about 10 minutes at a temperature of about 180° C. in a pressurized kneader (volume: 20 l), and transformed into pellets using a pelletizer. A wire-harness protecting tube (thickness: 0.3 mm; internal diameter: 10 mm) is formed by extrusion of the obtained pellets. The pellets are extruded in an extruder (diameter: 50 mm) at an extrusion (line speed) of 35 m/min. The temperatures of the composition (resin) during molding are shown in Tables 2 and 3.
[0051] The external aspect of the obtained product (extruded skin and material distribution) is evaluated.
[0052] Wear resistance is measured by the following technique. As shown in FIG. 2, a blade made of a quenched steel (shown in FIG. 1) is reciprocated in order to impart a to-and-fro motion on the sample. A 10N force is applied by the blade. The blade is reciprocated at a rate of one to-and-fro motion/second at 23° C., with a reciprocation amplitude of 10 mm. The number of to-and-fro cycles until the complete abrasion and disappearance of the sample is recorded. A number in excess of 150 is considered a good result.
[0053] The tensile strength up to breaking point is measured according to the tensile-strength test of JIS K 6310. A value of 15.7 MPa is considered to be a good result. The results shown in Tables 2 and 3.
TABLE 2 E1 E2 E3 E4 Composition Temperature (° C.) 190 210 230 250 External Aspect good good good good Wear Resistance 250 270 230 250 (number of to-and-fro cycles) Tensile Strength (MPa) 28.6 29.4 28.3 27.5
[0054] [0054] TABLE 3 CE1 CE2 CE3 CE4 Composition Temperature (° C.) 170 180 260 270 External Aspect bad bad bad bad Wear Resistance 30 50 120 110 (number of to-and-fro cycles) Tensile Strength (MPa) 14.9 15.1 20.5 19.7
[0055] When the composition (resin) temperature was lower than about 180° C. during extrusion, melt fractures appeared on the surface of the tube formed. When the temperature was higher than about 250° C., an unbalanced material distribution was formed.
[0056] The present application claims priority to Japanese Application No. 2001-268583, filed on Sep. 5, 2001, the disclosure of which is herein expressly incorporated by reference in its entirety.
[0057] While this invention has been described in conjunction with the specific embodiments above, it is evident that many alternatives, combinations, modifications, and variations are apparent to those skilled in the art. Accordingly, the exemplary embodiments of this invention, as set forth above are intended to be illustrative, and not limiting. Various changes can be made without departing from the spirit and scope of this invention. | The present invention is directed to a method of producing a cable protecting material. The method can include mixing and kneading an olefin-type polymer and suitable additives to prepare an olefin-type polymer composition, transforming the composition into pellets, and extruding the pellets at a temperature of from about 190° C. to about 250° C. The cable protecting material has a smoothly flowing skin and a well balanced material distribution. The cable protecting material also has good wear resistance. | 1 |
BACKGROUND
1. Field of the Invention
The present invention relates to the power train of a motor vehicle. More specifically, the present invention relates to a power transfer unit for distributing power to the rear wheels of the vehicle.
2. Description of the Prior Art
Most automobiles in the United States have typically utilized a rear wheel drive power delivery scheme. In adapting these rear wheel drive schemes into four wheel drive applications, a transfer case was, and often still is, positioned at the output of the transmission assembly. When engaged, the transfer case diverts a portion of the power coming from the transmission assembly from the rear wheels to the front wheels.
Currently in the United States, a significant portion of new automobiles are front wheel drive based vehicles. In a front wheel drive vehicle, typically both the engine and the transmission assembly are transversely oriented in the vehicle. By positioning the power plant and transmission assembly transversely, more direct coupling of the transmission assembly to the vehicle's transaxle and front wheels can be achieved.
With front wheel drive vehicles themselves becoming a mature market, a recent trend in the automobile industry has been to adapt front wheel drive schemes into all-wheel-drive or four-wheel-drive applications. This is accomplished by providing a power transfer unit that diverts a portion of the power from the front wheels to a rear wheel drive shaft and, subsequently, the rear wheels.
As a way of maximizing manufacturing resources, it is desirable to develop automotive products that can be utilized and incorporated across a variety of platforms. When incorporated into a vehicle, the power transfer unit is attached to the output face of the vehicle transmission. It is therefore in close proximity to the engine, the transmission, the steering rack and the exhaust manifold. Additionally, new PZEV catalytic converters are required to be located closer to the exhaust manifold so that they can achieve a quicker “light-off” of the catalyst. These PZEV catalytic converters also tend to be larger and generate higher temperatures than previous non-PZEV catalytic converters. The proximity to the engine, transmission and the other under hood components accordingly limits the size of the power transfer unit. Further, the high temperature of “manicat” catalytic converters and the previously mentioned PZEV catalytic converters means that polymer based products, such as lubricants and seals, need to be placed at as great a distance as possible from the PZEV catalytic converter.
One manner in which the overall size of the power transfer unit can be reduced is to similarly reduce the size of the gears, bearings and shafts of the power transfer unit itself. However, reducing the size of these components limits their overall torque carrying capacity.
An end result of all of the above is a desire for lateral compactness in the design of the power transfer unit. By compacting this lateral size of the power transfer unit, the power transfer unit can be configured as multiplatform assembly, in that the system itself can be designed for the worst case scenario, in other words the minimum lateral width available for a power transfer unit.
In order to achieve the greatest lateral compactness possible, the gears and bearings located inside the power transfer unit need to be located in the most space efficient manner possible. This can result in conflicts in the sizing and shaping of various components of the unit.
For example, in a three axis power transfer unit, a conflict can exist between the sizing of a hypoid ring gear and clearance between that ring gear and the support shaft of an idler gear. As used herein, the term “three axis power transfer unit” is one in which a driving gear, an idler gear and a driven gear, all located on parallel axes, are utilized in the power transfer unit. Because of the size of the ring gear typically required in power transfer units and because of the size of the bearings required to support the shaft upon which the idler gear is mounted, the ring gear and the idler gear bearing support are too large and located too longitudinally close together to enable these components to be mounted in a common plane. This results in these components being staggered laterally, forcing the power transfer unit to be wider than it might otherwise be. Even then, the size of the ring gear encroaches on the idler gear support shaft thereby limiting the size of that shaft. Clearly, merely reducing the cross-sectional diameter of the idler gear support shaft would result in reduced strength in the shaft and thereby limiting the size and capacity of the shaft, as well as the supporting bearing.
As seen from the above, there exists a need for increasing the lateral compactness of a power transfer unit so as to minimize its occupation of space in the engine bay and beneath the body of the vehicle and additionally to provide for a power transfer unit which exhibits multiplatform characteristics.
It is also and object of this invention to provide novel constructions for supporting an idler gear in situations where the ring gear positioning would be in conflict with the idler gear support, without increasing the lateral compactness of the power transfer unit.
SUMMARY
In satisfying the above need, as well as overcoming the enumerated drawbacks and other limitations of the related art, the present invention provides a power transfer unit in which the conflict between the ring gear and the idler gear support are resolved so as to enable a more laterally compact unit.
The output of the transmission assembly is coupled to an input member and to a first gear wheel, the driving gear, in a parallel gear set. The driving gear transfers rotation through an idler gear to a driven gear. That driven gear is mounted on a shaft whose rotational axis is generally parallel to the rotational axis about which the driving gear rotates. On the end of this transfer shaft is mounted a first bevel gear or gear ring of the non-parallel gear set. The first bevel gear engages a second bevel gear, such as a hypoid pinion gear, mounted to or formed with a shaft; this shaft being oriented generally perpendicularly to the rotational axis of the ring gear. The opposing end of the shaft is the output of the power transfer unit.
The idler gear is rotatably supported on a non-rotating support members that extends through the idler gear. In one embodiment, the non-rotating support member is a boss extending from one side of the housing toward an opposing side of the housing. In another embodiment, the non-rotating support member is a stationary shaft.
By providing the support for the idler gear through a non-rotating support member, bearing supports for that support member are eliminated. By eliminating these bearing supports, additional area within the power transfer unit is freed up so as to accommodate the ring gear of the non-parallel gear set in a more laterally compact construction. In other words, the ring gear of the non-parallel gear set need not be laterally staggered or spaced so as to avoid conflict with the bearing support for the idler gear.
Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after review of the following description, with reference to the drawings and the claims that are appended to and form a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view, with portions cut away, of a power transfer unit embodying the principles of the present invention;
FIG. 2 is a layout view of a power transfer unit according to a first embodiment of this invention; and
FIG. 3 is a layout view of a power transfer unit according to a second embodiment of the present invention.
DETAILED DESCRIPTION
Referring now to the drawings, FIG. 1 illustrates a power transfer unit 10 incorporating the principles of the present invention. The power transfer unit 10 includes a housing 12 in which the primary components of the unit 10 are integrally packaged. These components principally include a non-parallel gear set 14 and a parallel gear set 16 .
As used herein, the term “parallel gear set” is intended to refer to mechanisms with gear wheels that transfer power from a first shaft to a second shaft; the first and second shafts defining axes that are generally parallel to one another.
The term “non-parallel gear set”, as used herein, is intended to refer to any mechanism, (including, without limitation, mechanisms with gear wheels, mechanisms without gear wheels, gear trains, chain gears and belt systems) for transferring power from a first shaft to a second shaft; wherein the first and second shafts define axes that are generally not parallel to one another.
As mentioned above, the primary components of the power transfer unit 10 are all integrally packaged together and provided within a common housing 12 . Input and outputs 18 , 20 of the unit 1 Omay or may not protrude from the housing 12 depending on the specific design criteria and the application in which the power transfer unit 10 is being employed.
Rotation from an output of a transmission assembly (not shown) is coupled to the input 18 (hereafter “driving shaft 18 ”) of the power transfer unit 10 , and in particular, of the parallel gear set 16 . To facilitate engagement of the driving shaft 18 with the output of the transmission assembly, the end of the driving shaft 18 may be internally or externally splined as seen at 19 .
The first gear wheel, driving gear 22 , of the parallel gear set 16 is mounted to the driving shaft 18 by conventional means, such as unitarily forming the driving gear 22 with the driving shaft 18 (as illustrated) or welding the driving gear 22 to the driving shaft 18 , so as to rotate with rotation of the driving shaft 18 . This rotation thus occurs about an axis 24 defined by the driving shaft 18 . To facilitate rotation of the driving shaft 18 and the driving gear 22 , the driving shaft 18 is supported on bearings 26 , one such kind being tapered bearings, supported by the housing 12 .
Rotation from the driving gear 22 is transferred to an intermediate gear wheel, hereafter idler gear 28 , by means of external teeth 30 on the driving gear 22 which intermesh with external teeth 32 on the idler gear 28 . Preferably, the driving gear 22 and the idler gear 28 are helical gears so as to increase the torque transferring efficiency of the power transfer unit 10 . Alternatively, however, the teeth 30 , 32 could be formed straight. As the specific design criteria will dictate, the idler gear 28 may be larger, smaller or the same diameter as the driving gear 22 .
As seen in FIG. 2 in the first embodiment the idler gear 28 is rotatably supported on a stationary member extending through the idler gear 28 . As illustrated in the embodiment of FIG. 2 , the stationary member 34 is a stationary shaft “shaft 34 ”). The shaft 34 includes first and second ends 36 , 38 that are respectively received within first and second seats 40 , 42 defined in the housing 12 . To prevent rotation of the shaft 34 relative to the housing 12 , one or both of the first and second ends 36 , 38 may be fixed by welding, keying, press-fitting or otherwise fixedly engaging the ends 36 , 38 with the housing 12 at the seats 40 , 42 .
To enable enhanced lateral compactness of the power transfer unit 10 , and as further described below, the shaft 34 is provided with a part 44 defining a first diameter 46 and, a second part 48 defining a second diameter 50 , the second diameter 48 being less than the first diameter 46 . The idler gear 28 is rotatably supported on the first part 44 by radial bearings 52 . Axially, the idler gear 28 is supported by axial support members 54 . Since the axial loads applied to the idler gear 28 tend to be modest, the axial members 54 may be needle thrust bearings or simple thrust washers. The radial loads handled by the radial bearings 52 can be large and, accordingly, the radial bearings 52 must be relatively wide. In this instance, a pair of radial needle bearings are used. Through the use of needle bearings as the radial bearings 52 , their narrow radial dimension allows for the larger first diameter 46 of the first part 44 . Utilization of radially thicker tapered roller bearings would require the diameter of the first part 44 to be decreased resulting in a decrease in the strength of the stationary shaft 34 . However, if a lower strength shaft was acceptable for a given design, tapered roller bearings could be utilized or, if reduced diameter tapered roller bearings were designed, they could be used.
In order to provide lubrication to the radial needle bearings 52 , the stationary shaft 34 is provided with one or more lubrication ports 56 , 58 . The lubrication port 56 is located such that it delivers lubrication to annular space between the pair of radial needle bearings 52 . Accordingly, the lubrication port 56 includes a discharge opening on the exterior surface of the first part 44 of the stationary shaft 34 . To provide lubricant to the lubrication port 56 , another lubrication port 58 extends to the exterior surface of the shaft 34 at a location to entrain lubricant from the sump 60 of the power transfer unit 10 . As seen in the figure, the inlet opening of the lubrication port 58 is located in the region transitioning from the first part 44 to the second part 48 . To further facilitate the transfer of lubricant, the first part 44 of the stationary shaft 34 is provided with a hollow interior generally designated at 62 . Accordingly, both lubrication ports 56 , 58 extend from the exterior surface of the shaft 34 to the hollow interior 62 . As will be readily appreciated, other locations for the ports may be employed.
In order to locate and retain the idler gear 28 on the first part 44 of the stationary shaft 34 , a shoulder 64 is formed on the stationary shaft 34 in the region transitioning from the first part 44 to the second part 48 and axial members 54 engage the shoulder 64 . Axial movement of the idler gear 28 in the opposing direction is limited by appropriate portions of the housing 12 . Initial retention of the idler gear 28 on the stationary shaft 34 may be achieved by a snap ring 66 received within an appropriately located groove in the first part 44 of the stationary shaft 34 .
From the idler gear 28 , rotation is transferred to a third gear, driven gear 68 , of the parallel gear set 16 . The driven gear 68 is supported by a driven shaft 70 which is in turn rotatably supported on bearings 72 within the housing 12 . The driven gear 68 may be fixed to the driven shaft 70 in a conventional manner, including unitarily forming the driven gear 68 with the driven shaft 70 (as illustrated) or welding the driven gear 68 thereto. To facilitate the transfer of rotation from the idler gear 28 to the driven gear 68 , external teeth 74 on the driven gear 68 engage the teeth 32 of the idler gear 28 .
Provided in the above described manner, the driven shaft 70 defines the third axis 76 of the parallel gear set; the second axis 78 being defined by the stationary shaft 34 and about which the idler gear 28 rotates. The power transfer unit 10 is therefore known as a three axis unit.
In order to transfer rotation from the parallel gear set 16 to the non-parallel gear set 14 , a first bevel gear, ring gear 80 , of the non-parallel gear set 14 is mounted to the driven shaft 70 . Often, the location and diameter of the ring gear 80 is such that the ring gear 80 would typically encroach upon the support shaft of an idler gear. For this reason, ring gears have conventionally been laterally spaced on the driven shaft so as to be staggered from the idler gear support. This in turn forces the power transfer unit to be wider than if the encroachment did not occur. With the present invention, the encroachment is accommodated so as to allow for reduced lateral compactness in the power transfer unit. Specifically, the location of the ring gear 80 on the driven shaft 70 is such that the ring gear 80 extends to an area adjacent to that part of the stationary shaft 34 having a smaller diameter 50 , the second part 48 . Since the stationary shaft 34 does not require support bearings, additional area is freed up to accommodate and accept the ring gear 80 without requiring staggering or axial spacing thereof along the driven shaft 70 . This results in the lateral compactness of the power transfer unit 10 being reduced.
The ring gear 80 is provided with teeth 82 which engage teeth 84 of a second bevel gear 86 . The second bevel gear 86 is supported by one end of the output shaft 20 . The second bevel gear may be supported by the output shaft 20 by conventional means including unitarily forming the bevel gear 86 with the output shaft 20 (as illustrated) or welding the bevel gear 86 to the output shaft 20 . The output shaft 20 is supported within the housing 12 by bearings 88 enabling rotation of the shaft 20 about axis 90 . As seen in FIG. 2 , this second axis 90 of the non-parallel gear set 14 is generally oriented perpendicular to the axes 24 , 76 , 78 of the parallel gear set 16 and extends generally longitudinally with respect to the vehicle.
While not readily apparent in FIG. 2 , the axes 76 and 90 , about which the ring gear 80 and the second bevel gear 86 respectively rotate, may be such that the axes 76 and 90 intersect one another or do not intersect one another. In the later situation, which is preferred, the non-parallel gear set 16 is a hypoid bevel gear set.
Referring now to FIG. 3 , a second embodiment of a power transfer unit incorporating the principles of the present invention is generally illustrated therein and designated at 100 . Since the power transfer unit 100 incorporates many of the components and features illustrated and described in connection with FIG. 2 , common elements have been given like reference numerals. The difference between the first and second embodiments lies within the manner in which the idler gear 28 is supported in the power transfer unit. Accordingly, it is not believed that a detailed discussion regarding all of the common components of the power transfer unit from the prior embodiment is required in connection with the second embodiment. The reader's attention is therefore directed to the preceding of the detailed description in that regard. The discussion which follows will be limited to the manner in which the idler gear 28 is supported in this second embodiment.
Similar to the first embodiment, the idler gear 28 of the second embodiment is rotatably supported on a stationary member 92 extending through the idler gear 28 . In the second embodiment, however, the stationary member 92 is a boss (“boss 92 ”). The boss 92 is unitarily formed with the housing 12 and extends from a first side 94 of the housing toward a second side 96 of the housing 12 . The boss 92 is thus formed as an extension off of the first wall 94 and includes a cylindrical wall 98 terminating at a closed end 102 . The exterior surface of the cylindrical wall 98 defines the bearing seat for the radial needle bearings 52 . Axially, the idler gear 28 is supported by axial support members 54 , which, again, may be needle thrust bearings or simple trust washers. In order to locate and retain the idler gear on the boss 92 , a shoulder 104 is formed about the outer periphery of the end wall 102 . While the boss 92 should be sufficiently stable and rigid on its own, the boss 92 may be further stabilized and located relative the second side 96 through the providing of an interlock 106 extending between the second side 96 of the housing and the end wall 102 of the boss 92 . While the interlock 96 may take many forms, it may include, but is not limited to, means such as dowels and pins.
To further facilitate the lateral compactness of the power transfer unit 100 , the end wall of the boss 92 preferably terminate adjacent to the corresponding lateral end of the idler gear 28 . The second side 96 of the housing is therefore formed with a recess 108 extending toward the interior of the power transfer unit 100 so as to be immediately adjacent to the end wall 102 . The recess 108 is formed and located such that the ring gear 80 extends to a location adjacent thereto and which is laterally adjacent to at least a portion of the boss 92 .
In order to provide lubrication to the radial needle bearings 52 , the boss 92 is provided with at least one lubrication port 110 . The lubrication port 110 includes a discharge opening in a radially exterior surface of the cylindrical wall 98 , which is located such that it delivers lubrication to the annular space between the pair of radial needle bearings 52 . The inlet opening of the lubrication port 110 is provided so as to extend through the end wall 102 of the boss 92 into the sump 60 of the power transfer unit. In this way lubricant can be entrained from the sump 60 to the radial needle bearings 52 .
As a person skilled in the art will readily appreciate, the above description is meant as an illustration of an implementation of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from the spirit of this invention, as defined in the following claims. | A motor vehicle power transfer unit for distributing torque from a transmission assembly between a front wheel drive line and rear wheel drive line. The power transfer unit includes a housing that encloses a parallel gear set and a non-parallel gear set, which are coupled between an input portion and an output portion of the power transfer unit. The parallel gear set includes a driving gear, and idler gear and a driven gear and the idler gear is rotatably supported on a non-rotating support member that extends through the idler gear. Constructed in this manner, reduced lateral compactness of the power transfer unit is achieved. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a heating apparatus for a fluid which is used as auxiliary heating means for a fluid such as an engine cooling water used for improving a starting performance of an engine for various kinds of vehicles mainly such as an automotive vehicle having a diesel engine and a gasoline engine as a power source at a time of a cold weather and a severe cold weather and heating a cabin of various kinds of vehicles including an electric vehicle and various kinds of ships, is used for pre-heating and rapidly increasing a temperature (shortening a warming up time) an engine cooling water of an engine driven power generator, a welding machine, a compressor and a construction machine, and is used for an apparatus for force feeding a hot water while increasing a temperature, a heating device of an air conditioning apparatus and a drying device such as a hair dryer, and more particularly to an apparatus for heating a fluid without using a separate heat exchanger and force feeding the fluid by a rotationally driven pump mechanism.
2. Description of the Prior Arts
Conventionally, as an auxiliary heating source for a vehicle such as an automotive vehicle which is used for heating an engine cooling water at a starting time in a cold weather area, there has been known a viscous type heater (refer to Japanese Patent Unexamined Publication Nos. 2-246823, 9-254637, 9-66729 and 9-323530 and Japanese Utility Model Unexamined Publication No. 4-11716).
The viscous type heater is of the type which heats up a viscous fluid such as a silicone oil by shearing so as to exchange heat with a circulating water circulating within a water jacket and utilize for a heating source. The structure is made, for example, such that a heat generating chamber is formed in an inner portion of a housing, the water jacket is formed in an outer area of the heat generating chamber, a drive shaft is rotatably supported to the housing via a bearing apparatus, a rotor capable of rotating within the heat generating chamber is fixed to the drive shaft, a viscous fluid such as a silicone oil is sealed in a gap between a wall surface of the heat generating chamber and the rotor, and a circulating water is circulated so as to be taken into the water jacket from a water inlet port and be fed out to an external heating circuit from a water outlet port.
In this kind of viscous type heater assembled in the heating apparatus of the vehicle, since the rotor is rotated within the heat generating chamber when the drive shaft is driven by an engine, the viscous fluid generates heat due to shearing in the gap between the wall surface of the heat generating chamber and the outer surface of the rotor, the generated heat is exchanged with the circulating water within the water jacket, and the heated circulating water is used for heating the vehicle such as the engine cooling water in the heating circuit.
However, since the viscous type heater mentioned above can realize a compact size and a reduced cost in accordance with a simple structure, can secure a high reliability and safety in accordance with a frictionless non-contact type mechanism, and can automatically stop an operation in accordance with a temperature control when a water temperature is increased and the auxiliary heater is not necessary, there is a feature that a wasteful energy is not used. However, as well as an independent heat exchanging mechanism and heating circuit are required, a temperature of the silicone oil can not be increased sufficiently because a heat resistance of the silicone oil used as the viscous fluid is limited to about 240° C., a lot of time is required before the silicone oil is mixed to be heated to a high temperature at a start time, and an amount of heat generated at a unit time tends to be gradually reduced in accordance that a shearing resistance is lowered due to a reduction of a viscosity when a temperature of the silicone oil is increased, so that there has been a problem that a quick heating effect can not be obtained at an engine cooled time. Accordingly, in particular, in the case of a cold district design vehicle mounting a diesel engine, the viscous type heater mentioned above is not sufficient in an efficiency, so that there has been desired an auxiliary heater installing an apparatus for force feeding the fluid while more quickly and efficiently increasing the temperature of the fluid to a high temperature.
Further, conventionally, a warm and hot air generating apparatus represented by an apparatus for force feeding a warm water while increasing a temperature thereof, a heating device of an air conditioning apparatus and a drying device such as a hair dryer is constituted by a heating source such as a heat exchanger and an electrically heating heater and a force feeding apparatus such as a blower, in which the heating source and the blower are arranged apart from each other at a desired distance. That is, the conventional warm and hot air generating apparatus is generally structured such that the blower is provided in front of the heating source, and an air fed from the blower is heated when passing through the heating source such as the electrically heating heater or warmed so as to be discharged. Here, in the case that the fluid is a liquid, it has been force fed by the pump after being heated by the heat exchanger or heated by the heat exchanger after being force fed by the pump.
However, in this kind of conventional heating and force feeding apparatus, there are the following disadvantages. (1) It is impossible to make the apparatus compact since the force feeding apparatus such as the heating source and the blower is essential, (2) in the case that the electric heating heater is used for the heating means for the air and the water, a heat resistance and a durability are deteriorated since the electric heating heater is weak against moisture and it costs high since it is necessary to insulate the heater, (3) the apparatus is not preferable in view of safety since there is a risk that the electric heating heater fires due to an overheat, and (4) the pump and the heat exchanger are required, and the heat exchanger requires a large exchanging calorie.
SUMMARY OF THE INVENTION
The invention is made by solving the disadvantages in the conventional fluid heating and force feeding apparatus mentioned above, and an object of the invention is to provide a fluid heating and force feeding apparatus which is excellent in heat resistance and durability, rich in safety, can be intended to be made compact by assembling a heating apparatus and a force feeding apparatus, can perform a quick heating, and can be made compact even when being assembled with a heater and a heat exchanger.
In order to achieve the object mentioned above, in accordance with the invention, there is provided a heating and force feeding apparatus for a fluid comprising a conductive material portion provided at least a part of a member which is rotated and apply a velocity energy to the fluid, and magnets opposing to the conductive material portion at a slight gap and mounted within a casing, wherein the fluid within the casing is heated due to a slip heat generated by relatively rotating the velocity energy applying member and the magnets and is applied a velocity energy so as to be force fed, the velocity energy applying member is constituted by a sirocco fan, a multiblade fan, an axial fan, a mixed flow fan, a centrifugal fan or an eddy current fan, or formed by an impeller or a pump wheel, a conductor is mounted to the velocity energy applying member, the magnet and the conductor are arranged in such a manner as to oppose to each other at a slight gap, a whole of the velocity energy applying member is made of a conductive material, the magnet is constituted by a permanent magnet, a thermal ferrite or an electromagnet, and a hysteresis material, a hysteresis material having a surface in the side of the magnet to which an eddy current material or a magnetic material are adhered, or an eddy current material is used for the conductor.
A magnet type heater in the invention is of the type in which the fan, the impeller or the pump wheel having the fixed magnet and the conductor portion are arranged in such a manner as to oppose to each other at a slight gap, and the magnet and the conductor are relatively rotated (including the case that they are inversely rotated to each other) so as to heat the fluid due to the slip heat generated in the conductor. This magnet type heater has a feature that the temperature of the fluid can be increased for a short time, and an excellent heat resistance can be obtained.
The invention is structured such as to integrally combine this magnet type heater with the fan and the impeller, and has a feature that the temperature of the force fed fluid can be increased for a short time, a continuous force feeding can be thereafter performed at a certain temperature and an excellent heat resistance can be obtained.
A first aspect thereof is a heating and force feeding apparatus for a fluid in which a sirocco fan and a magnet type heater are combined, a second aspect thereof is a heating and force feeding apparatus for a fluid in which a centrifugal fan and a magnet type heater are combined, a third aspect thereof is a heating and force feeding apparatus for a fluid in which a multiblade fan and a magnet type heater are combined, a fourth aspect thereof is a heating and force feeding apparatus for a fluid in which an axial fan or a mixed flow fan and a magnet type heater are combined, a fifth aspect is a heating and force feeding apparatus for a fluid which is structured such that a centrifugal fan or a wheel and a magnet type heater are combined and heating can be performed at two portions comprising a flow inlet port side and a discharge port side of the fluid, a sixth aspect is a heating and force feeding apparatus for a fluid in which an eddy current fan (generally referred to as "a vortex fan") and a magnet type heater are combined, and a seventh aspect is a heating and force feeding apparatus for a fluid in which a water pump and a magnet type heater are combined.
In this case, the eddy current fan corresponds to a structure in which a principle of an eddy current pump (a Wesco pump) is applied to a gas, and is principally structured such as to surround an impeller so as to form a ventilation passage by a casing. Accordingly,the air flowing from the suction port generates a pressure increase due to a centrifugal force of the impeller and is pressed out to the ventilation passage, and the air is pressed by the wall of the casing and repeated till the discharge port while generating the vortex movement by means of the next vane, so that the structure has a high pressure wind performance.
That is, in accordance with the invention, the magnet such as the permanent magnet, the thermal ferrite or the electromagnet, the material having a large magnetic hysteresis (hereinafter, refer to as "hysteresis material"), the eddy current material or the magnetic material are constituted by two members of the conductor (the heat generating body) such as the hysteresis member attached to the surface in the side of the magnet or the eddy current material, and these two members are opposed to each other at a slight gap and relatively rotate the magnet and the conductor so as to shear the magnetic path, thereby utilizing a slip heat generated in the side of the conductor. Accordingly, the structure has a feature that it is possible to heat to a temperature of 200 to 600° C. for some seconds to some tens of seconds by using the conductor for the heat generating body. The gap is not particularly limited, however, is generally 0.3 to 1.0 mm.
In this case, "the slip heat generation" mentioned above means that the eddy current is generated within the conductor when moving (rotating) the conductor in a direction of crossing the magnetic field within the magnetic field generated by the magnet, so that a heat is generated due to an electric resistance of the conductor and the eddy current flowing therein.
Further, as ON/OFF control means for the magnet type heater, an electromagnetic clutch and a thermal ferrite can be employed. In this case, the thermal ferrite is generally structured such that a soft ferrite is adhered to the permanent magnet, and corresponds to a magnet having a characteristic that a magnetic path passes through the soft ferrite when generating the heat to a temperature equal to or more than a certain temperature and the magnetic path is formed outside the soft ferrite when the heat generation temperature is inversely reduced to a temperature equal to or less than a certain temperature, so that in the case that the thermal ferrite is used for the magnet, it is possible to automatically perform an ON/OFF control. Accordingly, an ON/OFF control system is not required. Further, it is possible to employ a system for measuring a temperature of the fluid by using a temperature sensor and turning off the electromagnet or weakening a magnetic force at a time of reaching a predetermined temperature so as to control the heat generation amount.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross sectional side view which shows an embodiment of a heating and force feeding apparatus for a fluid corresponding to a first aspect of the invention;
FIG. 2 is a vertical cross sectional side view which shows another embodiment of a heating and force feeding apparatus for a fluid corresponding to the aspect mentioned above;
FIG. 3 is a vertical cross sectional side view which shows the other embodiment of a heating and force feeding apparatus for a fluid corresponding to the aspect mentioned above;
FIG. 4 is a vertical cross sectional side view which shows an embodiment of a heating and force feeding apparatus for a fluid corresponding to a second aspect of the invention;
FIG. 5 is a vertical cross sectional side view which shows another embodiment of a heating and force feeding apparatus for a fluid corresponding to the second aspect of the invention;
FIG. 6 is a vertical cross sectional side view which shows an embodiment of a heating and force feeding apparatus for a fluid corresponding to a third aspect of the invention;
FIG. 7 is a vertical cross sectional side view which shows an embodiment of a heating and force feeding apparatus for a fluid corresponding to a fourth aspect of the invention;
FIG. 8 is a vertical cross sectional side view which shows another embodiment of a heating and force feeding apparatus for a fluid corresponding to the fourth aspect of the invention;
FIG. 9 is a vertical cross sectional side view which shows an embodiment of a heating and force feeding apparatus for a fluid corresponding to a fifth aspect of the invention;
FIG. 10 is a vertical cross sectional side view which shows an embodiment of a heating and force feeding apparatus for a fluid corresponding to a sixth aspect of the invention;
FIG. 11 is a vertical cross sectional side view of a main portion which shows an embodiment of a heating and force feeding apparatus for a fluid applied to a turbine engine having a multi stage compressor;
FIG. 12 is a vertical cross sectional side view which shows an embodiment of a heating and force feeding apparatus for a fluid corresponding to a seventh aspect of the invention;
FIG. 13 is a vertical cross sectional side view which shows another embodiment of a heating and force feeding apparatus for a fluid corresponding to the seventh aspect of the invention; and
FIG. 14 is a graph which shows an example of a heat generation data between a rare earth magnet and an eddy current material experimentally performed by the inventors.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the invention, reference numerals 1A to 1K denote a fan casing, reference numeral 2 denotes a sirocco fan, reference numeral 12 denotes a centrifugal fan, reference numeral 12' denotes a wheel, reference numeral 22 denotes a multiblade fan, reference numeral 32 denotes an axial fan, reference numeral 42 denotes a mixed flow fan, reference numeral 52 denotes an eddy current fan (a vortex fan), reference numeral 62 denotes a fan wheel, reference numeral 3 denotes a drive motor, reference numeral 4 denotes a rotational axis, reference numeral 5 denotes a bearing apparatus, reference numeral 6 denotes a permanent magnet, reference numeral 6-1 denotes an electromagnet, reference numerals 7, 17, 27, 37, 47 and 57 denote a magnet supporting body, reference numeral 8 denotes a compressor disc, reference numeral 8-1 denotes a compressor blade, reference numeral 9 denotes a stator segment, reference numeral 9-1 denotes a stator, reference numeral 10 denotes a pulley, reference numeral 11 denotes an electricity supplying cable, and reference numeral 63 denotes a cylinder block.
That is, FIG. 1 exemplifies a heating and force feeding apparatus for a fluid in accordance with a first aspect of the invention in which a sirocco fan and a magnet type heater are combined. The apparatus is structured such that a plate of the sirocco fan is made of a conductive material, a permanent magnet arranged in such a manner as to oppose to the conductive plate with a little gap is assembled in the fan casing, and a fluid within the fan casing is heated due to a slip heat generated in the plate in accordance with a rotation of the plate. In the exemplified structure, a rotating vane is constituted by a donut-like plate 2-1 having a suction hole 2-1a pierced in a center thereof, a disc-like plate 2-1 and a plurality of blades 2-2 horizontally provided between both plates 2-1, the sirocco fan 2 is structured such as to support the rotating vane to the rotational axis 4 of the drive motor 3 via the bearing apparatus 5 within the fan casing 1A, and the disc-like plate 2-1 of the sirocco fan 2 is made of a conductive material. The donut-like permanent magnet 6 opposing to the conductive material plate 2-1 at a little gap is mounted within the fan casing 1A via a yoke 6a. In this case, the conductive material plate is structured such that an eddy current material or a magnetic material is adhered to a surface of a base material such as the hysteresis material or the iron plate in the side of the permanent magnet 6, or structured by the eddy current material itself.
In the fluid heating and force feeding apparatus having the structure mentioned above, when energizing the drive motor 3, at the same time when the fluid flowing into the fan casing 1A flows as shown by an arrow, the magnetic path formed between the conductive material plate 2-1 and the permanent magnet 6 mounted to the fan casing 1A is shut off, so that the slip heat is generated in the conductive material plate 2-1. The heat generated in the conductive material plate 2-1 is exchanged with the fluid flowing within the fan casing 1A through the plate and the blade 2-2 to which the heat is transmitted from the plate, thereby becoming a warm air or a hot air and being discharged from a discharge port (not shown).
Further, the fluid heating and force feeding apparatus shown in FIG. 2 is structured such that in the fluid heating and force feeding apparatus shown in FIG. 1, the disc-like plate 2-1 is made of a nonconductive material, a donut-like conductor 2-1b is attached to the nonconductive material disc-like plate 2-1 and a heat generated in the conductor 2-1b heats the fluid flowing within the fan casing 1A.
Still further, the fluid heating and force feeding apparatus shown in FIG. 3 is structured such that the magnet type heaters of the fluid heating and force feeding apparatus shown in FIG. 1 are doubly employed, that is, both of the plates 2-1 of the rotating vane which is constituted by the donut-like plate 2-1 having the suction hole 2-1a pierced in a center thereof, the disc-like plate 2-1 and a plurality of blades 2-2 horizontally provided between both plates 2-1, are made of a conductive material. The donut-like permanent magnet 6 opposing to each of the conductive material plates 2-1 at a little gap is assembled within the fan casing 1B via a yoke 6a. Accordingly, in this fan, the slip heat generated in both of the conductive material plates 2-1 is exchanged with the fluid flowing within the fan casing 1B, thereby becoming a warm air or a hot air and being discharged from a discharge port (not shown).
Next, FIG. 4 exemplifies a fluid heating and force feeding apparatus employing a centrifugal fan in accordance with a second aspect of the invention. The fan is structured such that a conductor is mounted to the rotational vane or the rotational vane is made of a conductive material, a permanent magnet arranged in such a manner as to oppose to the conductor or the conductive material rotational vane at a little gap is assembled in the pump main body, and the fluid within the fan is heated by the slip heat generated in the conductor due to the rotation of the rotational vane. The exemplified apparatus is structured such that a back plate 12-1 of the centrifugal fan 12 mounted to the rotational axis 4 of the drive motor 3 within a fan casing 1C is made of a conductive material, the annular magnet supporting body 7 opposing to the conductive material back plate 12-1 at a little gap is mounted to the fan casing 1C, and the drive motor 3 is mounted on a back surface of the magnet supporting body 7. The donut-like permanent magnet 6 is mounted to the magnet supporting body 7 via the yoke 6a. In this case, as well as the structure shown in FIG. 1, the conductive material back plate 12-1 is structured such that the eddy current material or the magnetic material is adhered to the surface of the base material such as the hysteresis material or the iron plate in the side of the permanent magnet 6, or constructed by the eddy current material itself.
In the fluid heating and force feeding apparatus having the structure mentioned above, when energizing the drive motor 3, at the same time when the fluid flowing into the fan casing 1C flows as shown by an arrow, the magnetic path formed between the conductive material back plate 12-1 and the permanent magnet 6 of the magnet supporting body 7 mounted to the fan casing 1C is shut off, so that the slip heat is generated in the conductive material back plate 12-1. The heat generated in the conductive material back plate 12-1 is exchanged with the fluid flowing within the fan casing 1C through each of the rotational vanes, thereby becoming a warm air or a hot air and being discharged from a discharge port.
FIG. 5 exemplifies a system structured such that an electromagnet is used in place of the permanent magnet 6 of the fluid heating and force feeding apparatus shown in FIG. 4 mentioned above and a slip heat is generated in the conductor in the side of the rotation by the electromagnet. The structure of the heating and force feeding apparatus is made such that the centrifugal fan 12 is mounted to the rotational axis 4 within a fan casing 1D supported to an outer periphery of the rotational axis 4 via the bearing apparatus 5, an electromagnet 6-1 opposing to the conductive material back plate 12-1 of the centrifugal fan 12 at a little gap is mounted to the fan casing 1D, the rotational axis 4 is driven by the motor or the engine via the pulley 10 or a belt (not shown), and the electromagnet 6-1 is energized by the power supplying cable 11. In this case, the conductive material back plate 12-1 is structured such that the eddy current material or the magnetic material is adhered to the surface of the base material such as the hysteresis material or the iron plate in the side of the permanent magnet 6 or constructed by the eddy current material itself in the same manner as that shown in FIG. 1.
In the fluid heating and force feeding apparatus having the structure shown in FIG. 5, when the rotational axis 4 is. driven by the motor or the engine via the pulley 10 and a belt (not shown), at the same time the fluid flowing into the fan casing 1D flows as shown by an arrow, the magnetic path formed between the conductive material back plate 12-1 and the electromagnet 6 mounted to the fan casing 1D is shut off, so that the slip heat is generated in the conductive material back plate 12-1. The heat generated in the conductive material back plate 12-1 is exchanged with the fluid flowing within the fan casing 1D through each of the blades in the rotational vane, thereby becoming a warm air or a hot air and being discharged from a discharge port.
FIG. 6 exemplifies a fluid heating and force feeding apparatus using a multiblade fan in accordance with a third aspect of the invention, in which the structure is made such that a cylindrical multiblade fan 22 mounted to the rotational axis 4 of the drive motor 3 provided in the back surface side of a fan casing 1E is made of a conductive material, and a plurality of plate-like magnet supporting bodies 17 opposing to the fan at a little gap are provided on an inner wall of the fan casing 1E in the side of a fluid inlet port within the cylindrical multiblade fan 22 in a projecting manner. In the same manner, an arc-plate shaped permanent magnet 6 is adhered to the magnet supporting body 17. In this case, as well as the structure shown in FIG. 1, the conductive material multiblade fan 22 is structured such that the eddy current material or the magnetic material is adhered to the surface of the base material such as the hysteresis material or the iron plate in the side of the permanent magnet 6, or constructed by the eddy current material itself.
In the fluid heating and force feeding apparatus having the structure mentioned above, when energizing the drive motor 3, at the same time when the fluid flowing into the fan casing 1E flows as shown by an arrow, the magnetic path formed between the conductive material cylindrical multiblade fan 22 and the permanent magnet 6 of the magnet supporting body 17 mounted to the fan casing 1E is shut off, so that the slip heat is generated in the conductive material cylindrical multiblade fan 22. The heat generated in the conductive material cylindrical multiblade fan 22 is exchanged with the fluid flowing within the fan casing 1E, thereby becoming a warm air or a hot air and being discharged from a discharge port.
FIG. 7 exemplifies a fluid heating and force feeding apparatus using an axial fan in accordance with a fourth aspect, in which the structure is made such that an axial fan 32 mounted to the rotational axis 4 of the drive motor 3 provided in the back surface side of a fan casing 1F is made of a conductive material, a plurality of magnet supporting bodies 27 opposing to the axial fan 32 at a little gap are provided on an outer periphery of the drive motor 3, and the permanent magnet 6 is mounted to the magnet supporting body 27. In this case, as well as the structure shown in FIG. 1, the conductive material axial fan 32 is structured such that the eddy current material or the magnetic material is adhered to the surface of the base material such as the hysteresis material or the iron plate in the side of the permanent magnet, or constructed by the eddy current material itself.
In the fluid heating and force feeding apparatus having the structure mentioned above, when energizing the drive motor 3, at the same time when the fluid flowing into the fan casing 1F flows as shown by an arrow, the magnetic path formed between the conductive material axial fan 32 and the permanent magnet 6 of the magnet supporting body 27 mounted to the outer periphery of the drive motor 3 is shut off, so that the slip heat is generated in the conductive material axial fan 32. The heat generated in the conductive axial fan 32 is exchanged with the fluid flowing within the fan casing 1E, thereby becoming a warm air or a hot air and being discharged from a discharge port.
Further, FIG. 8 exemplifies a fluid heating and force feeding apparatus using a mixed flow fan and the structure thereof is the same as that of the fluid heating and force feeding apparatus using the axial fan shown in FIG. 7 mentioned above. That is, the structure is made such that a mixed flow fan 42 mounted to the rotational axis 4 of the drive motor 3 provided within a fan casing 1G is made of a conductive material, and a plurality of magnet supporting bodies 37 opposing to the mixed flow fan 42 at a little gap are obliquely fixed to an outer periphery of the drive motor 3 so as to correspond to an incline of the mixed flow fan 42 and the permanent magnet 6 is mounted to the magnet supporting body 37. In this case, as well as the structure shown in FIG. 1, the conductive material axial fan 42 is structured such that the eddy current material or the magnetic material is adhered to the surface of the base material such as the hysteresis material or the iron plate in the side of the permanent magnet, or constructed by the eddy current material itself.
An operation of the fluid heating and force feeding apparatus having the structure mentioned above is the same as that of the fluid heating and force feeding apparatus using the axial fan shown in FIG. 7. Accordingly, when energizing the drive motor 3, at the same time when the fluid flowing into the fan casing 1G flows as shown by an arrow, the magnetic path formed between the conductive material mixed flow fan 42 and the permanent magnet 6 of the magnet supporting body 37 mounted to the drive motor 3 is shut off, so that the slip heat is generated in the conductive material mixed flow fan 42. The heat generated in the conductive material mixed flow fan 42 is exchanged with the fluid flowing within the fan casing 1G, thereby becoming a warm air or a hot air and being discharged from a discharge port.
FIG. 9 exemplifies a fluid heating and force feeding apparatus using a centrifugal fan and a wheel in accordance with a fifth aspect, in which the structure is made such that a heating can be performed at two portions comprising a flow inlet side and a discharge port of the fluid. Accordingly, the exemplified structure is made such that back plates 12-1 and 12'-1 of the centrifugal fan 12 and a wheel 12' which are mounted to the rotational axis 4 of the drive motor 3 in a fluid flow inlet port P1 side and a fluid discharge port P2 side of a fan casing 1H by means of a fastening nut 13 are made of a conductive material, and an annular magnet supporting body 47 opposing to the conductive material back plates 12-1 and 12'-1 at a little gap is provided to the same rotational axis 4 as that mentioned above via the bearing apparatus 5 between the centrifugal fan 12 and the wheel 12' in such a manner as not to rotate. The donut-like permanent magnet 6 is mounted to the magnet supporting body 47 via the yoke 6a.
In the fluid heating and force feeding apparatus having the structure mentioned above, when energizing the drive motor 3, at the same time when the fluid flowing into the fan casing 1H from the flow inlet port P1 flows as shown by an arrow, the magnetic path formed between the conductive material back plate 12-1 in the flow inlet port P1 side and the permanent magnet 6 of the magnet supporting body 47 mounted to the rotational axis 4 is shut off, so that the slip heat is generated in the conductive material back plate 12-1 and is exchanged with the fluid flowing through the flow inlet port P1 side within the fan casing 1H. Subsequently, the fluid becoming a warm air or a hot air is again heated by the heat generated in the discharge port side wheel 12' and the conductive material back plate 12'-1 in the side of the discharge port P2 of the fan casing 1I, and is discharged from the discharge port P2 as a fluid having a higher temperature. In the case of this fluid heating and force feeding apparatus having a so-called double structure, it is possible to make a temperature difference between the flow inlet port P1 side and the discharge port P2 side of the fluid large by a little air amount.
A fluid heating and force feeding apparatus shown in FIG. 10 corresponds to a combination of the eddy current fan (the vortex fan) in accordance with the sixth embodiment and the magnet type heater, in which the structure is made such that an eddy current fan 52 rotatably mounted to the rotational axis 4 of the drive motor 3 provided in the back surface side of a fan casing 1I via the bearing apparatus 5 within the fan casing 1I is made of a conductive material, and a magnet supporting body 57 to which the permanent magnet 6 is adhered on an outer peripheral surface of a cylindrical portion 57-1 opposing to the fan at a little gap is mounted to a front surface side of the non-rotational fan casing 1I within the eddy current fan 52. In this case, as well as the structure shown in FIG. 1, the conductive material eddy current fan 52 is structured such that the eddy current material or the magnetic material is adhered to the surface of the base material such as the hysteresis material or the iron plate in the side of the permanent magnet 6, or constructed by the eddy current material itself.
In the fluid heating and force feeding apparatus having the structure shown in FIG. 10 mentioned above, when energizing the drive motor 3, at the same time when the fluid flowing into the fan casing 1I from the flow inlet port P1 flows as shown by an arrow, the magnetic path formed between the conductive material eddy current fan 52 and the permanent magnet 6 of the non-rotational magnet supporting body 57 is shut off, so that the slip heat is generated in the conductive material eddy current fan 52 and is exchanged with the fluid flowing within the fan casing 1I, thereby becoming a warm air or a hot air and being discharged from the discharge port P2.
A fluid heating and force feeding apparatus shown in FIG. 11 is structured such that a permanent magnet 6 arranged in such a manner as to oppose to a conductor 8-2 mounted to a side surface in the side of the stator side of the compressor disc 8 at a little gap is mounted to an inner side of the stator segment 9 via the yoke 6a, and the permanent magnet 6 arranged in such a manner as to oppose to a conductor 8-3 mounted to an outer peripheral surface of a compressor blade 8-1 at a little gap is mounted to a fan casing 1J via the yoke 6a. In this case, as well as the structure shown in FIG. 1, the conductors 8-2 and 8-3 mentioned above is structured such that the eddy current material or the magnetic material is adhered to the surface of the base material such as the hysteresis material or the iron plate in the side of the permanent magnet, or constructed by the eddy current material itself.
In the case of the fluid heating and force feeding apparatus having the structure mentioned above, when the turbine is rotated, at the same time when a fluid (an air) force fed to a combustion chamber (not shown) flows as shown by an arrow, the magnetic path formed between the conductor 8-3 mounted to an outer peripheral surface of the compressor blade 9-1 and the permanent magnet 6 mounted to a fan casing 1J is shut off, so that the outer peripheral surface of the compressor blade 9-1 is heated by the slip heat generated thereby. Further, the magnetic path formed between the conductor 8-2 mounted to an outer side of the compressor disc 8 and the permanent magnet 6 mounted to the inner side of the stator segment 9 is shut off, so that the compressor disc 8 is heated by the slip heat generated thereby, and the fluid force fed to the combustion chamber is previously heated.
FIG. 12 exemplifies a fluid heating and force feeding apparatus using a water pump in accordance with a seventh aspect of the invention, in which the structure of the heating and force feeding apparatus is made such that it is mounted to an outer periphery of the rotational axis 4 via the bearing 5 and a mechanical seal 14, a fan wheel 62 is mounted to the rotational axis 4 within a fan casing 1K, a conductor 62-1b opposing to the permanent magnet 6 at a little gap is adhered to a surface of an impeller 62-1 disposed in the outer periphery of the fan wheel 62, and the rotational axis 4 is driven by a pulley, a belt, a motor or an engine (not shown). When the rotational axis 4 is driven, at the same time when the fluid such as an engine cooling water flows as shown by an arrow due to an operation of the impeller 62-1, the magnetic path formed between the conductor 62-1b mounted to a back surface of the pump wheel 62 and the permanent magnet 6 mounted to the permanent magnet body 7 mounted to the fan casing 1K via the yoke 6a is shut off, so that the slip heat is generated in the conductor 62-1b.
The heat generated in the conductor 62-1b is exchanged with the fluid flowing through the impeller 62-1 within the fan casing 1K, thereby becoming a liquid having an increased temperature and being discharged from a discharge port.
Next, in a water pump of the engine shown in FIG. 13, there is shown a system in which the structure is made such that an electromagnet is employed in place of the permanent magnet, the pump wheel in the rotating side is made of a conductive material, and a slip heat is generated in the fan casing 1K itself. In this case, the structure is made such that as well as an electromagnet 6-1 is assembled within the fan casing 1K and a power supply cable 11 is connected to the electromagnet 6-1 so as to supply power to the electromagnet 6-1, the conductive material pump wheel 62 is mounted to a distal end of the rotational axis 2 rotatably supported within the fan casing 1K via the bearing apparatus 5 and the mechanical seal 14 at a little gap with respect to the electromagnet 6-1. In this case, the magnetic path formed between the conductive material pump wheel 62 and the electromagnet 6-1 assembled within the fan casing 1K is shut off, so that the slip heat is generated in the pump wheel 62, the generated heat is mainly discharged from the impeller 62-1, and the liquid exchanged with the engine cooling water flowing within the fan casing 1K and having an increased temperature is introduced into the cylinder block 63. In this case, when the eddy current material such as a copper plate is adhered to the opposing surface of the electromagnet 6-1 of the conductive pump wheel 62, a heat generating effect can be improved.
FIG. 14 exemplifies a heat generation data on the basis of a combination of a rare earth magnet and an eddy current material experimentally performed by the inventors, and the data shows a relation between a time (sec) and a temperature which are measured by arranging the rare earth permanent magnet and the eddy current material in an opposed manner with setting a gap therebetween to 1.0 mm and variously changing a rotating speed in the side of the magnet in a state of fixing the eddy current material.
In accordance with the data, it can be understood that a slip heat having a temperature of 200 to 600° C. is generated in the conductor for some seconds to some tens of seconds by arranging the magnet and the conductive body in an opposed manner at a little gap and relatively rotating the magnet and the conductor.
In each of the embodiments mentioned above, the description is given of the structure in which the conductor having the fan or the impeller or the wheel is rotated, the magnet is fixed within the casing and both of them are relatively rotated. However, the structure can be modified, for example, such that the magnet side is rotated by the independently provided drive motor so as to control the relative rotational speed of the both to achieve a speed increase, a speed reduction and an inverse rotation, thereby capable of controlling a calorie, or the both can be inversely rotated to each other by using a planetary gear mechanism.
As mentioned above, in accordance with the invention, the following effects can be obtained.
(1) Since the magnet type heater corresponding to the heat source is strong against the moisture with different from the electric heater, an insulation of the heater is not required, so that a manufacturing cost is inexpensive and the apparatus can be used in the liquid.
(2) Since the magnet type heater is used for the heat source, whereby the fan itself can be used as a heat generating body, an independent blower is not required, so that in addition that it is possible to make the apparatus small and compact, it is possible to make compact even when combining with the heater and the heat exchanger.
(3) Since the non-contact type magnet type heater is used for the heat source, performances of a maintenance free, a heat resistance and a durability are excellent.
(4) There is no risk of a fire due to an overheat in the case of the electric heater, a significant safety is achieved and a quick heating can be performed.
(5) Since it is possible to heat in the flow inlet port side and the discharge port side of the fluid, it is possible to obtain a fluid having a high temperature by a little air amount.
(6) It is possible to improve a combustion efficiency and an engine output of the turbine engine, and it is possible to prevent an icing at the frontmost stage. | An apparatus is provided for simultaneously generating a fluid flow and heating the flowing fluid. The apparatus includes a conductive material provided on at least a part of a member which is rotated. The rotatable member generates the flow of the fluid to be heated. Magnets are opposed to one side of the conductive material with a slight gap and are mounted within a casing for the rotatable member. Fluid flows through the casing and is heated due to a slip heat energy generated by rotating the conductive material relative to the magnet. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to an arrangement for supplying consumers, particularly mobile consumers, with pressure fluids.
Supply of mobile consumers with pressure fluids, especially in underground excavations, whether it is a pressure air or a hydraulic liquid, is always connected with difficulties when the action radius of the consumer is relatively great. One possibility of supplying includes, for example, the introduction of pressure storages forming energy reservoirs. Depending upon the storage volume and air consumption, the consumer can have a respective active region within a predetermined action time. After this, the storage must be changed or recharged with respective time consumption in stationary positions. In addition to these disadvantages, there is also another disadvantage that for a substantially satisfactory action radius, a storage with a great volume must be provided for the consumer, so that its transportation capacity is naturally limited.
As long as the action radius of a consumer is limited, the utilization of flexible dragging conduits can be taken into consideration. There is here, however, the danger that especially with long dragging conduits and poor operational conditions, the dragging conduits are damaged or completely destroyed, which leads to stoppage of an operation. If the action region of the consumer must be expanded, the dragging conduits must be uncoupled. Such an exchange on situ is however always connected with high expenses for the uncoupling of the dragging conduits and subsequent coupling of them.
Moreover, there are many rail systems which provide for a possibility to supply an air consumer with energy over the length of the rail region. These systems have certain problems at the connection points of the rail portions to form the rail track in the sense of leakage losses or factual situations so that no energy withdrawal is here possible. As a result of this, the used length of these systems is also limited.
The latter described air rail systems includes such a system in which a plurality of nipples is provided at distances from one another on a rail track, and a withdrawing carriage is displaceable on the rail track from one nipple to the other. The nipples are formed as magnet valves. When a withdrawal carriage is located at the respective nipple, the permanent magnet provided in the withdrawing carriage is placed in such position that the magnet valve in the rail track is opened. In this withdrawing position, the withdrawing carriage cannot move. On the other hand, no air withdrawal is possible when the withdrawing carriage is located between two nipples. Moreover, the positioning of the withdrawing carriage requires a manual actuation for a withdrawing conduit. An automatic continuous energy withdrawal of a great action radius is not possible here.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an arrangement for supplying consumer, particularly mobile consumers, with pressure fluids, such as pressure air or pressure liquid, which avoids the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide an arrangement of the abovementioned type which is improved so that it has a simpler construction and a higher leakage tightness and at the same time the respective consumer can be supplied with pressure fluid over a greater system length in each operative position in an uninterrupted manner.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a supplying arrangement having a rail track for guiding a pressure fluid, a plurality of nipples arranged along the rail track at a distance from one another, and at least one withdrawing unit movable over the rail track and acting upon the nipples, wherein the length of the withdrawing unit and the distance between two neighboring nipples are selected so that one nipple is always located in automatically unlocking region of the withdrawing unit.
The determination of the length of the withdrawing unit relative to the distance between two neighboring nipples provides for a possibility to continuously withdraw pressure fluid from the rail track. Since always one nipple is located in the respective active region of the withdrawing unit which provides for the automatic unlocking of the nipple, pressure fluid can be withdrawn continuously, regardless of the fact whether the consumer moves or does not move. The withdrawing unit can be formed as a component of the consumer. On the other hand it can be coupled with the consumer in any manner.
The invention is especially advantageous for the use in underground excavations. It can supply both excavation machines and transporting devices in mine face and gallery continuously with pressure fluids. The action radius of the consumer is almost unlimited. Time losses for coupling are dispensed with. Damages to the rail track and the withdrawing unit do not lead to a function loss. Both structural elements can be formed sturdy so as to advantageously satisfy the requirements made with respect to the underground excavations. The supply arrangement in the sense of the rail track and the withdrawing unit can have such a small cross-sectional dimension that it can extend in even very narrow mine spaces and in poor spatial conditions.
In accordance with an advantageous embodiment of the present invention, the rail track is tubular and the withdrawing unit completely encloses the tubular rail track and advantageously has a cylindrical shape. The tubular form of the rail track, particularly the round cross section, as well as the cylindrical design of the withdrawing unit which completely surrounds the rail track, provide for the possibility to have a very slim construction with respective flexibility, so that there are no problems during displacement on curves, through depressions or over passages. It is also possible to provide sealing of the rail track and the withdrawing element with conventional sealing elements. No special constructions are necessary. Since the withdrawing unit is guided directly on the rail track, no additional guiding conduits and the like are necessary. The tubular form is maintenance-favorable and also damage-resistant as long as the withdrawing unit slides with a great play on the rail track.
A further feature of the present invention is that the nipples or valves are arranged under the action of a pair of radially displacing plungers which are connected with one another so as to form a kind of a scale balance and extend outwardly beyond the periphery of the rail track. The plungers cooperate with inclined surfaces in end portions of the withdrawing unit and thereby act on the nipples. With this construction it is guaranteed that a nipple opens first when it is separated by the withdrawing unit in both movement directions. The unlocking plungers are arranged before and after each nipple as considered in the longitudinal direction of the rail track. Because of its scale balance-like coupling, they can displace under the action of the inclined surfaces in the end portions of the withdrawing unit both relative to one another, and also relative to the valve plunger of the nipple or valve. It is therefore guaranteed that a radial displacement of the valve plunger and thereby opening of the nipple is possible only when both unlocking plungers extend parallel and the valve plunger is driven. In the closing position, the free ends of the unlocking plunger extend outwardly beyond the periphery of the rail track so that by the contact with the inclined surfaces of the withdrawing unit a radial displacement in the desired periphery can take place. The position of the unlocking plungers is radially adjustable.
When one inclined surface of the withdrawing unit reaches a nipple, the inclined surface first radially displaces one unlocking plunger. Therefore, the traverse which connects the unlocking plungers with one another turns about its pivot point on the valve plunger, without however radially displacing the latter. When the withdrawing unit moves further, then because of the respective design in the interior of the withdrawing unit it is guaranteed that the radial position of the radially inwardly displaced unlocking plunger is maintained. When then after passing the nipple, also the second unloading plunger is brought in contact with the inclined surfaces, it is also displaced radially inwardly. Now the valve plunger is driven since as described hereinabove, the unlocking plunger which has been first displaced radially inwardly can no longer extend outwardly beyond the rail track. The nipple is opened via the traverse. The distance between the unlocking plungers is so dimensioned relative to the respective nipple, that the valve plunger is displaced with reliability radially only when the sealing for the rail track provided in the withdrawing unit is pressed by the nipple.
This selection of the nipple and the opening characteristic allows a local drawing off of the pressure fluid. For this purpose the respective withdrawing device must be formed so that simultaneously both unlocking plungers associated with one nipple are displaced radially inwardly so that thereby the nipple is opened.
For guaranteeing unobjectionable actuation of the unlocking plungers also during relative rotation of the withdrawing unit on the rail track, the inclined surfaces are formed as components of funnel-shaped recesses provided in the end sides of the withdrawing unit.
Still a further feature of the present invention is that the withdrawing unit is provided with a withdrawing chamber located between the funnel-shaped recesses and sealed therefrom, and a plurality of supporting members surrounding the rail track are arranged in the withdrawing chamber. The thus arranged supporting members are provided to function so as to hold the radially inwardly displaced unlocking plungers in their position, so that in the withdrawing chamber there is always pressure fluid which can be supplied to the respective consumer.
Yet another feature of the present invention is that the supporting members are formed as convolutions of a helical spring arranged in the withdrawing chamber. The helical spring surrounds with the required play the rail track and is embedded at its end in respectively shaped chambers in the withdrawing unit.
Instead of the helical springs, the supporting members can be formed as a plurality of rings arranged near one another and holding the radially inwardly displaced unlocking plungers in their position. Both the rings and also the helical springs guarantee that the withdrawing unit can be moved on a curved rail track without affecting the withdrawing functions.
The manufacture and mounting of the inventive supply arrangement is simplified and facilitated when in accordance with another feature of the present invention the nipples together with the unlocking plungers are formed as components of short tubular portions which are sealingly and releasably incorporated in the rail track.
Finally, the withdrawing unit can be formed rigid or composed of flexible material. Both possibilities provide for adjustment, in connection with the supporting members arranged in the interior of the withdrawing unit, to a strongly curved portions of the rail track.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, 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 DRAWING
FIG. 1 is a view showing a horizontal longitudinal section of a mine face with two connected galleries in an underground excavation, with roof supporting units, a face conveyor, and an access device on a plan view;
FIG. 2 is a view showing a longitudinal section of a rail track which guides a pressure fluid and provided with a withdrawing unit, in a vertical longitudinal section on an enlarged scale;
FIG. 3 is a view substantially corresponding to the view of FIG. 2, but showing another embodiment of the withdrawing unit guided on the rail tracks, partially in section;
FIG. 4 is a view showing a longitudinal section of the rail track and the withdrawing unit of FIG. 2 in vertical longitudinal section on an enlarged scale;
FIG. 5 is a view substantially corresponding to the view of FIG. 4 but with the displaced withdrawing unit;
FIG. 6 is a view substantially corresponding to the views of FIGS. 4 and 5, with the withdrawing unit displaced further; and
FIG. 7 is a view showing an enlarged vertical section of the rail track taken along the line VII--VII in FIG. 4.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a face 1 of an underground pit mine with two galleries 2 and 3 connected with one another.
Reference numeral 4 identifies coal to be removed, whereas reference numeral 5 identifies a mine field from which coal has been already removed.
A face conveyor 7 extends in the longitudinal direction of the face along a face of working 6. Driving stations 8 of the face conveyor 7 lie in the galleries 2 and 3. An extraction machine can be guided on the face conveyor 7. The face space 1 is retained open by mine roof supports 9 arranged near one another. The mine roof supports have roof caps 10 located under the cutting lines in the plane view, and floor beams 11 located above the cutting lines in the plan view.
The mine roof supports 9 also serve for protection of an access arrangement 12 for transporting personnel and materials. The access arrangement 12 is associated with a withdrawal unit 13 which is forcedly moved on a rail track 14 extending in the longitudinal direction of the face 1 and connected via a connecting band 15 with pressure air supply conduits 16 and 17 located in the galleries 2 and 3.
As can be seen from FIG. 2, the rail track 14 is composed of individual rail portions 18, as well as short tubular portions 19 provided with plugs 20 for pressure air and incorporated between the rail portions. The tubular portions 19 and the rail portions 18 are assembled with one another tightly, but releasably. The withdrawal unit 13 for pressure air, which is guided on the rail track 14 has seals 21 at its both ends. The length X of the withdrawal unit 13 between the seals 21 is dimensioned relative to the distance Y between two successive plugs 20 so that only one plug 20 is located in the region of action of the withdrawing unit 13. The consumer 12 is shown schematically in FIG. 2.
In FIG. 2 the withdrawing unit 13 has a substantially rigid housing 22. In contrast, withdrawing unit 13 in FIG. 3 has a housing 23 of flexible material, such as for example, rubber. Both housings 22 and 23 are formed so that the rail track 14 can be strongly bent without affecting the continuous withdrawl of pressure air. The housing has an elongated cylindrical shape.
FIG. 2 in connection with FIGS. 4-6 shows that each withdrawing unit 13 has funnel-shaped recesses 24 at its ends, and a withdrawal chamber 25 sealed with respect to the recesses 24. Supporting members 26 which surround the rail track 14 extend in the longitudinal direction of the withdrawal chamber 25. In the shown embodiment the supporting members 26 are formed as convolutions of a helical spring 27. The helical springs 27 embrace the rail track 14 which is tubular and are fixed in chambers 28 provided in the vicinity of the seals 21.
The funnel-shaped recesses 24 in end portions 29 of the withdrawing units 13 form inclined surfaces 30. These inclined surfaces cooperate with the plugs 20 in the tubular portions 19, as will be explained hereinbelow.
As can be seen from FIGS. 4-7, each plug 20 has a fluid nozzle 31. The fluid nozzle 31 cooperates with a pair of plungers 32 and 33 which are spaced from one another in a longitudinal direction of the rail track, connected with one another in a scale balance-like manner, and project beyond the periphery of the rail track 14. The plunger 32 and 33 are displaceable by the inclined surfaces 30 radially toward the axis of the rail track and act upon the nozzle 31 in unlocking manner. The plungers 32 and 33 are supported in a wall 34 of the short tubular portion 19. At their rear side, the plungers 32 and 33 are supported spatially hingedly on a traverse 35, which in turn is centrally supported on a valve plunger 36 also spatially hingedly. The traverse 35 is fixed by an adjusting screw 37 in its position on the valve plunger 36.
As can be particularly recognized from FIG. 7, the valve plunger 36 is arranged in an insert 38 of a valve housing 39 provided with a sealing seat 40 for a closing body 41. The valve housing 39 is advantageously screwed into the tubular portion 19. A cap 42 is formed in correspondence with the contour of the tubular portion 19. A recess 43 in the wall 34 of the tubular portion 19 serves for receiving an end portion 44 of the valve plunger 36 when it is displaced radially. A spring 45 presses the closing body 41 against the sealing seat 40. Opening 46 in the valve housing 39 connects the interior of the valve housing 39 with the interior of the tubular portion 19.
FIG. 4 shows a position of a withdrawing unit 13 at a distance from a nipple 31. Both unlocking plungers 32 and 33 extend only insignificantly beyond the periphery of the tubular portion 19.
When the withdrawing unit 13 is moved further, the wall of the funnel-shaped recess 29 which forms the inclined surface 30, presses the first unlocking plunger 32 radially inwardly whereby the traverse 35 turns about a hinge point on the valve plunger 36. The unlocking plunger 33 located behind the nipple 31 extends thereby somewhat further out of the tubular portion 19. This situation is shown in FIG. 5. Since the traverse 35 can turn, the valve plunger 36 does not move radially. First when in accordance with FIG. 6 the withdrawing unit 13 is displaced still further, and the inclined surface 30 displaces radially inwardly the unlocking plunger 36 which is rear in the movement direction of the withdrawing unit 13, the traverse 35 is thereby displaced and the valve plunger 36 is moved. The valve 31 opens and pressure air can flow from the rail track 14 into the withdrawal chamber 25 in the withdrawing unit 13. From here, the pressure fluid is supplied to the consumer 12. The radial inwardly pressed position of the unlocking plungers 32 and 33 is maintained by the convolutions 26 of the helical spring 27.
When the unlocking plunger 32 at the other end of the receiving unit 13 reaches in the inlet region the inclined surface 30 located therein, it is pressed radially outwardly by the spring 45 via the valve plunger 36 and the traverse 35, and the closing body 31 is again pressed against the sealing seat. Thereby, the withdrawal process for this nozzle 31 is finished.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in an arrangement for supplying consumers, particularly mobile consumers, with pressure fluids, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | An arrangement for supplying consumers, particularly mobile consumers, with pressure fluids such as pressure air or pressure liquid, particularly in underground excavations, has a composite rail track for guiding a pressure fluid, a plurality of nipples arranged at a predetermined distance from one another in the longitudinal direction of the rail track, and at least one fluid withdrawing unit which cooperates with the nipples to open the latter and has a length selected with respect to the distance between two neighboring nipples so that one nipple is always located in the effective region of the withdrawing unit to be opened by the latter. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to outdoor lighting devices, particularly such as those used in gardens or to mark trails.
BACKGROUND OF THE INVENTION
[0002] There has been a long felt need for a garden light having a relatively long run time, which is also battery operated, and is relatively inexpensive to manufacture.
SUMMARY OF THE INVENTION
[0003] The present invention provides a lighting device having a battery housing to hold a battery, a light housing having a light source and a lens assembly into which said light source will emit light when activated, said battery and said light source being in circuit with a switch to open and close said circuit, said light housing being moveable relative to said battery housing to motivate said switch to open and/or close said circuit.
[0004] The light housing is preferably a part of or is connected to an intermediate body portion. The intermediate body portion is slidably connected to said battery housing. The light housing or the intermediate body portion is preferably biased away from said battery housing with the bias being produced by a compression spring.
[0005] The battery housing can include an elongated switch engagement member. The intermediate body portion preferably houses a printed circuit board on which is mounted the light source and switch. The lens assembly can include a reflector around the light source. Preferably a second reflector is located away from said light source. Preferably the lens assembly includes a cylindrical lens. The cylindrical lens can have its internal surfaces frosted to assist the diffusion of light over the surface of the lens. The outside surface of the cylindrical lens can include striations or lenticules therearound.
[0006] The light housing and battery housing can be elongated. The battery housing can include a screw-on cover to access the internal portions of the battery housing. The base preferably includes a recess to receive a mounting spike. The base can also be adapted to be received by an attachable foot.
[0007] Movement of the light housing relative to the battery housing is preferably limited. The limitation of movement is preferably by means of parts of the intermediate body portion engaging formations on the battery housing.
[0008] The intermediate body portion can include at least two shoulders to engage the battery housing at two spaced locations preferably the shoulders one annular or port annular. Preferably the light source is an LED or low wattage lamp and preferably the battery is of a D size. A cap can be positioned over the lens assembly to assist in maintaining structural integrity and water resistance.
[0009] In a further preferred embodiment the circuit of the lighting device further includes a light sensitive element adapted to detect an ambient light level, and wherein said light source is illuminated in response to said detected ambient light level.
[0010] Preferably the said light source is deactivated if the detected ambient light level is above a predetermined ambient light threshold. Preferably the light source is illuminated if the detected ambient light level is below a predetermined ambient light threshold.
[0011] Preferably the light sensitive element is selected from the following light sensitive elements:
[0012] a light dependent resistor, a photodiode or a phototransistor.
[0013] Preferably the brightness of said light source is varied in response to said detected ambient light level. In use when the detected ambient light level falls within a predetermined range of ambient light levels the brightness of said light source can be either increased or decreased when said ambient light level increases. In use when the detected ambient light level falls within a predetermined range of ambient light levels the brightness of said light source can be either increased or decreased when said ambient light level decreases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0015] FIG. 1 is a perspective view of an outdoor light with a spike base;
[0016] FIG. 2 is a cross-section through the outdoor light of FIG. 1 ;
[0017] FIG. 3 is a front elevation of an outdoor light similar to that of FIG. 1 with an attached foot instead of a spike base;
[0018] FIG. 4 is a cross-section through the light of FIG. 3 ;
[0019] FIG. 5 is a perspective view of an outdoor light similar to that of FIG. 1 ;
[0020] 5 FIG. 6 shows a schematic representation of a circuit suitable for use in the outdoor light of FIGS. 1 to 5 ; and
[0021] FIG. 7 shows a schematic representation of a circuit suitable for use in an outdoor light which is adapted to turn itself off during the day.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] As illustrated in FIG. 1 , an outdoor light 2 which is cylindrical in construction, has a battery housing 4 , a battery housing cover 6 , an intermediate body portion 8 , which is slidably connected to the battery housing 4 and a light housing 10 which is secured to the intermediate body portion 8 , each of which will be described in more detail later. The intermediate body portion 8 is illustrated as being separate from and joined to the light housing 10 . If desired the intermediate body portion 8 and the light housing 10 can be integrally formed.
[0023] At the top of the light housing 10 is a cap 12 . The battery housing cover 6 has depending therefrom a mounting spike 14 which terminates in a pointed head 16 . The mounting spike 14 is indicated in FIG. 1 as discontinuous so as to indicate that one or more such spikes can be joined together to form the mounting spike.
[0024] As illustrated in FIG. 2 in cross-section, the battery housing 4 has at its lowest end, a male thread 42 , which receives a female thread 62 of the battery housing cover 6 . The battery housing 4 at its upper end includes a spring contact 44 for engaging the negative terminal 22 of a D size dry cell or battery 20 . A wire (not illustrated) connects the spring contact 44 to a printed circuit board 81 .
[0025] The battery housing 4 includes at its upper end an elongated switch contact column 46 which terminates in a flat contacting surface 48 to engage a switch 82 mounted on the underside of printed circuit board 81 .
[0026] Beneath the surface 48 and around the column 46 is a flange 41 to provide a bearing surface against which compression spring 24 can act.
[0027] The cylindrical outer surface of the battery housing 4 includes annular surfaces 43 , 45 , 47 and 49 which provide bearing surfaces against which parts of the intermediate body portion 8 can bear and slide. As can be seen from FIG. 2 , the bearing surfaces 45 and 49 are recessed relative to the surfaces 43 and 47 . The intermediate body portion 8 has corresponding radially inwardly directed flanges 83 and 85 . The change of section from the surfaces 45 to 47 , and 45 to 43 respectively produces an upper shoulder 50 and a lower shoulder 52 between which the flange 85 can move. The upper shoulder 50 between surfaces 45 and 47 , limits the intermediate body portion 8 in the upward direction, whilst the lower shoulder 52 (being the shoulder formed between the surfaces 43 and 45 ) limits the downward movement of the intermediate body portion 8 relative to the battery housing 4 .
[0028] The internal cylindrical surface of the intermediate body portion 8 , together with flanges 83 and 85 engage and slide relative to the annular surfaces 43 , 45 , 47 and 49 making the slidable interconnection between the battery housing 4 and intermediate body 8 structurally sound for the purposes to which the outdoor light 2 will be put, whilst achieving slidable relative movement between the two components.
[0029] The battery housing cover 6 includes a positive battery contact 64 which makes contact with a metal contact (not illustrated) contained within the battery housing 4 . The opposite end of this contact, within the battery housing 4 is connected by a wire (not illustrated) to the printed circuit board 81 .
[0030] The screwed connection of the battery housing cover 6 to the battery housing 4 helps to prevent ingress of water from this connection.
[0031] The battery housing cover 6 includes in its lower portions a central, cylindrical wall 66 which receives in the internal portions thereof, the outside diameter of the mounting spike 14 . The mounting spike 14 receives in its proximal end a pointed head 16 .
[0032] The upper portion of the intermediate body 8 includes radially inwardly directed shoulders 84 which support the printed circuit board 81 . The printed circuit board 81 is held against the shoulder 84 by means of a shaped LED support 86 which helps to prevent the LED from laterally moving relative to the printed circuit board 81 . The LED 30 extends from the printed circuit board 81 so that the diode of the LED extends into the light housing 10 .
[0033] The light housing 10 at its base 102 is held by means of a shoulder 104 in a groove 106 on the intermediate body 8 . An internal wall 108 surrounds the LED support 86 and clamps the LED support 86 and printed circuit board 81 into position as illustrated in FIG. 2 . A locator or index means (not illustrated) is provided either on the printed circuit board 81 or LED support 86 so that when assembled, the switch 82 is coaxial with the column 46 on battery housing 4 .
[0034] The upper portion of the light housing 10 is a lens assembly 110 . The lens assembly 110 is made from a transparent or translucent material with the internal wall 112 having a frosted finish to help diffuse light over the cylindrical surface of the lens assembly 110 .
[0035] The external surface of the lens assembly 110 is made up of striations or lenticules 114 which are generally annular in nature and surround the external surface of the lens assembly 110 . The upper end of the lens assembly 110 includes a reflector surface 116 whilst the internal face 118 of the surface 108 is also a reflector surface. Thus any light emitted by the LED 30 will reflect off the surfaces 118 and 116 which helps to reflect light through the cylindrical wall of the lens assembly 110 .
[0036] The cap 12 has a cylindrical recess 122 to receive the upper end of the lens assembly 110 . The lens assembly 110 and the intermediate body 8 are made from two halves which are sonically welded together. However, for structural integrity, the cap 12 is positioned by means of a compressed fit and/or sonically welded to the lens assembly 110 thus helping to keep the lens assembly 110 as an integral unit.
[0037] In use, the outdoor light 2 is assembled by first pushing the mounting spike 14 with pointed head 16 into the ground. If desired, additional mounted spikes 14 and pointed heads 16 can be added end on end to produce a conjoined mounting spike of a desired height. Once the mounting spike 14 is in the ground, an assembly of the battery cover 6 , battery housing 4 , intermediate body portion 8 , lens assembly 10 and cap 12 is positioned onto the mounting spike 14 by sliding the cylindrical recess formed by cylindrical wall 66 over the upper end of mounting spike 14 .
[0038] Once fully assembled, the outdoor light 2 can be switched on by pushing downwardly in the direction of arrow 200 against the cap 12 which will force the light housing 10 and intermediate body portion 8 to move relative to the battery housing 4 against the bias of spring 24 , thereby pushing the switch 82 against the surface 48 atop of the column 46 . This downward action will close the circuit if it is open thus illuminating the LED 30 and the lens assembly 110 . To switch off the outdoor light 2 , the cap 12 is pushed in the direction of arrow 200 to open the circuit.
[0039] In another embodiment, the outdoor light 2 can include circuitry to switch off the LED 30 as the level of ambient light increases. Such a light sensitive embodiment will include at least one light detector, such as a light dependent resistor (LDR), photodiode, phototransistor, or other optically sensitive circuit component. The light detector(s) is mounted on the light 2 , such that it is able to detect the level of ambient light in the vicinity of the outdoor light 2 .
[0040] In order to prevent the light emitted from the outdoor light 2 activating the light detector and turning the LED 30 off, the light detector should be mounted such that the light omitted from the LED 30 does not impinge upon it, for example by mounting the light detector facing upward on the top face of cap 12 , or on the lower end of the intermediate body portion 8 . Other measures to prevent the LED 30 activating the light detector may also be employed, such as selecting the LED 30 or light detector such that the omission spectrum of the LED 30 falls outside the response spectrum of the light detector. The sensitivity of the light detector, or associated circuitry, can also be selected such that the light emitted by the LED 30 of the outdoor light 2 , or an adjacent outdoor light of the same type, does not activate the power down mode.
[0041] It is envisaged that by selecting appropriate circuitry the light sensitive power down mode can operate to turn the LED 30 off when the ambient light reaches a particular intensity. Advantageously, once the user has placed their outdoor light 2 in the ground and activated it by pushing down on the cap 12 , the user then does not need to turn the light off. This will automatically occur when the sun comes up or a brighter light source is used to illuminate an area. In either case, the use of the outdoor light in bright conditions would be unnecessary and lead to an unwanted drain on the light's batteries.
[0042] Alternatively the light detector could be configured to switch the LED 30 on and off as appropriate as the ambient light changes. Thus once the user has placed their outdoor light 2 in the ground and activated it by pushing down on the cap 12 the LED will come on and turn off as required. This embodiment is particularly advantageous when setting up the outdoor light during the day, for use during the night. Thus the outdoor light can be placed in a desired position and activated, but will not turn on the LED until the sun sets, thus allowing early activation of the light, without unnecessary use of the battery's power while the sun is up when the outdoor light will have limited effect.
[0043] In a further embodiment, the circuit and light detector can be configured to control the intensity of the LED's 30 output to compensate for changes in ambient light. This embodiment is similar to that described above. However, rather than simply using the light detector to turn the LED on or off, the circuit is configured such that the light emitted by LED 30 ramps down as the ambient light increases, or ramps up as the ambient light decreases. A combination of the two modes of operation can also be used. In such an embodiment the LED is not illuminated until the ambient light falls below a predetermined threshold, but once the LED is illuminated, its intensity is varied to compensate for changes in ambient light. If the ambient light increases over a predetermined level the LED is deactivated.
[0044] Alternatively, the variation in illumination intensity of the LED may be varied so that over a predetermined range of ambient light levels the brightness of the light source increases with increasing ambient light levels, so as to render the brightness of the LED as perceived by a viewer, to be constant. This mode of operation may be particularly advantageous if the outdoor light is being used to mark a path, walkway or the like, and it is necessary to ensure the pathway can be easily discerned in conditions of varying light.
[0045] Illustrated in FIGS. 3 and 4 is the outdoor light 2 similar to that of FIG. 2 except that the mounting spike 14 has been removed and an annular foot 202 added. The annular foot 202 has a central aperture 203 and a cylindrical recess 204 to receive the outside diameter of the cylindrical skirt of the battery housing cover 6 . The annular foot 202 provides added stability allowing the outdoor light 2 when combined with a foot 202 to be placed onto a path, deck, patio or the like. The central aperture 203 allows access to the cylindrical wall 66 , when the foot 202 is in position. Thus, a user can still position the combined outdoor light 2 and foot 202 onto a mounting spike.
[0046] FIGS. 6 and 7 show suitable circuits for use in an outdoor light as described above. As will be appreciated by those skilled in the art the circuit 600 is powered by a DC power source 620 (which corresponds to dry cell 20 of FIG. 2 ) and includes a switch 610 (which corresponds to switch 82 of FIG. 2 ), and a white LED 630 (corresponding to LED 30 of FIG. 2 ). The circuit additionally includes transformer 640 which is used to step up the voltage from 1.5 volts, as output from the power source 620 , to 3.6 volts, which is required to illuminate the white LED 630 . As described above a user of the outdoor light can then close the switch 620 of the circuit by pushing down on the cap ( 12 in FIG. 2 ) of the light. This completes the circuit and illuminates the LED 630 .
[0047] FIG. 7 shows a circuit 700 for use in a light sensitive embodiment of the present invention. The circuit 700 differs from the circuit 600 of FIG. 6 in that, in addition to a power source 620 , a switch 610 , a transformer 640 , and white LED 630 the circuit 700 includes a light dependent resistor 750 . The light dependent resistor (LDR) 750 is configured to increase in resistance when exposed to light. Thus, when the LDR 750 is exposed to light, eg. during the day, the LDR's 750 resistance increases and causes the transistor BC109 to shut off current to transistor S8040 thereby shutting turning off LED 630 . It should be noted that exposing the LDR 750 to light does not break the circuit by opening the switch 610 , but rather by preventing current flow through the transistors BC109 and S8040. Thus once the garden light is activated, as described above by pushing down on cap 12 , the circuit 700 is continually discharging power, irrespective of whether the LED 630 is illuminated or not, until the switch is opened. However, the rate of discharge of the circuit 700 in bright conditions with the LED 630 not illuminated is less than the self-discharge rate of the circuit 600 shown in FIG. 6 when its switch 610 is open. Thus the circuit 700 does not result in any unnecessary discharge of power while the white LED is not emitting light despite the circuit being closed.
[0048] In FIGS. 1 to 4 the external surface of the lens assembly 110 is made up of circumferential striations or lenticules 114 which are generally annular in nature and surround the external surface of the lens assembly 110 . These are can be replaced by a lens assembly 10 ′ which does not include such lenticules as is illustrated in the outdoor light 2 of FIG. 5 .
[0049] It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.
[0050] The foregoing describes embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto, without departing from the scope of the present invention. | The present invention provides a lighting device having a battery housing to hold a battery, a light housing having a light source and a lens assembly into which said light source will emit light when activated, said battery and said light source being in circuit with a switch to open and close said circuit, said light housing being moveable relative to said battery housing to motivate said switch to open and/or close said circuit. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates in general to the field of storing cold liquids in a large storage tank. Typical operation conditions of such storage tanks are in the range of 0° C. to −200° C. More particularly, the present invention relates to tanks intended for storing substances which are liquid in the temperature range between −5° C. and −196° C., wherein storage takes place under atmospheric pressure. For storage tanks of this type, a Euro-norm applies, indicated as “atmospheric, refrigerated, liquefied gas storage tanks with operating temperatures between −5° C. and −196° C.”. Such tanks are fixedly positioned at a storage location, either above bottom surface or sunken completely in the bottom. Horizontal dimensions of such tanks are typically within the range of 10meters to 100 meters, and the height can typically be up to 50 meter.
[0002] Still more particularly, the present invention relates to tanks intended for storing liquid LNG, having a temperature in the range of −102° C. to −165° C.
BACKGROUND OF THE INVENTION
[0003] Tanks for storing such cold liquids, indicated hereinafter as “cold storage tanks”, have to meet a number of design requirements. The constructive strength should be large enough to carry the weight of the liquid, and to withstand the forces that occur in the case of an earthquake. The tank should be liquid-tight, vapor-tight, and should fulfill an isolating function between the surroundings and the cold liquid in the interior. Finally, provisions must be made to prevent that the tank immediately empties completely towards the surroundings in the unlikely event of a leakage of the tank.
[0004] Known cold storage tanks are built according to one of the following concepts.
[0005] A first tank concept, indicated as “tank-in-tank” concept or “full containment tank” concept, comprises an inner vessel arranged in an outer vessel. The outer vessel is typically made from reinforced concrete. The inner vessel can be made from concrete or cryogenic resistant steel. The inner surface of the concrete outer vessel is provided with a metal plating to serve as a vapour barrier and gas barrier. Furthermore it is provided up to a certain height with a cryogenic metal plating on top of an insulating layer to serve as a thermal corner protection of the concrete, indicated as secondary liner. In this first tank concept, the functions mentioned above are fulfilled by different components. The inner vessel contains the cold liquid. In the unlikely event of a leakage of the inner vessel into the outer vessel, the secondary liner prevents the cold liquid from reaching the outer concrete vessel, especially the corner area thereof. The space between the inner vessel and the outer vessel is filled with insulation material. This secondary liner makes the tank to be of a “full containment type”.
[0006] A second tank concept, indicated as “membrane tank” concept, has a thin metal plating or membrane attached to a load-bearing insulation, which again is attached to the inner surface of the outer vessel over the entire height of the outer vessel. This tank has no separate inner vessel as the membrane fulfils the functions of the inner vessel. The membrane has a complicated profile in order to allow expansion and contraction caused by the temperature changes. It is noted that this tank also has incorporated a secondary liner by means of a triplex foil within the load-bearing insulation to obtain the status of a “full containment type”.
[0007] When building such a tank according to the first tank concept, first the outer vessel is built. During the construction of the walls, a large dome-shaped carbon steel roof is built within its perimeter and, when the walls are finished, the roof is hoisted or blown to the top of the walls and fastened to close the tank. Then, metal plates are arranged at the inner side of the concrete bottom and walls and are welded to anchoring points in the concrete walls and to each other as well as to the carbon steel roof in order to provide for a vapour-tight and gas-tight enclosure. A first insulation layer is arranged on the bottom of the outer vessel, and also on part of the wall. The insulation is in the form of cellular glass, which material only reaches the desired pressure resistance with special bitumen products. Also PVC foam can be used. A ringbeam is now installed onto this insulation layer to support the inner vessel. Inside the ringbeam, additional insulation layers are applied to obtain the desired insulation value. The inner vessel is now built on top of the bottom insulation and ringbeam. The first insulation layer in the annular space and onto part of the wall is now covered by a cryogenic resistant metal plating of Invar or 9% Nickel steel to act as a liquid-tight secondary liner. These steel plates must be made to measure on location and must be welded to each other and the inner tank in a liquid-tight manner.
[0008] On top of the inner vessel, a suspended ceiling is hung from the dome-shaped roof and completely covered with a substantially thick layer of fibre-glass insulation.
[0009] Then, insulation material is arranged in the space between the wall of the inner vessel and the wall of the outer vessel. This insulation comprises a resilient glass fibre blanket against the wall of the inner tank, and the rest of the annular space is filled by pouring perlite grains.
[0010] Thus, building such a tank according to the state of the art is very labour-intensive. Herein it is the disadvantage that applying several different kinds of insulation material and sealing material at the several locations must be done at strongly different moments in time, while furthermore those activities lie on the Critical path, i.e. subsequent activities must wait until previous activities have been completed.
[0011] During use, especially the inner vessel will experience volume variations as result of thermal contraction and changing liquid load levels. This has as a consequence that the dimensions of the annular space between the inner vessel and the outer vessel vary, causing the conventionally used perlite grains to tend to settle themselves, i.e. the height of the perlite bulk decreases. In order to maintain the desired insulation value, therefore, perlite must regularly be filled. The resilient glass fibre blankets are to reduce the settling of the perlite grains, but still do not prevent the necessity of a regularly filling of perlite.
[0012] When building such a tank according to the second tank concept, i.e. a “membrane” tank, first the outer vessel is built. During the construction of the walls, a large dome shaped carbon steel roof is built within its perimeter and, when the walls are finished, the roof is hoisted or blown to the top of the walls and fastened to close the tank. Then, prefabricated insulation panels comprising of PVC or polyurethane load-bearing insulation between two plywood outer surfaces are fastened to the outer concrete vessel using load-bearing mastics to accommodate for the curvature of the tank. Thin steel membrane plates are then anchored to the plywood inner surface and welded together. In order to obtain a full containment status, the prefabricated insulation panels of the bottom and lower wall part incorporate a secondary liner within the panels of a triplex foil.
[0013] Also the membrane tank uses a suspended ceiling hung from the dome-shaped roof and completely covered with a substantially thick layer of fibre-glass insulation.
[0014] Thus, building such a tank according to the state of the art requires very accurate manufacturing processes using special ply-woods, adhesives, expensive insulation materials. The anchoring of the ply-wood panels to the concrete outer vessel, the jointing of the secondary liner of triplex foil on the job-site and the complexity of welding the complicated profiles of the steel membrane makes the entire construction of such a tank very labour-intensive and requires the use of very skilled labour.
[0015] A general disadvantage of these two types of tanks is to be seen in the need of handling and welding metal plates for manufacturing the liner and attaching the liner to the wall of the outer vessel, and welding metal plates of the inner tank or the membrane tank. WO-02/29310, the contents of which is incorporated herein by reference, has proposed a method for building a storage tank which avoids the need of metal plates. In the storage tank of this publication, which can be indicated as a third type of tank, PVC-foam plates provided with a coating provided with gravel are attached to the inner side of the concrete wall of the tank. Over the PVC-foam, a monolithic coating layer is applied. On the bottom of the tank, a first coating layer is applied; then PVC-foam blocks are arranged, and finally a monolithic coating layer is applied. The coating layers are sprayed.
[0016] The third type of tank, and its building method, as proposed by WO-02/29310 already has major advantages over the first and second types of tank. Nevertheless, further improvements are possible.
[0017] An important aim of the present invention is to provide a still further improved tank concept.
[0018] More particularly, the present invention aims to provide a design and building method for a storage tank for cold liquids, wherein a substantial saving on building time and building cost can be achieved, while maintaining or perhaps even improving the insulation properties and the sealing properties.
SUMMARY OF THE INVENTION
[0019] According to an important aspect of the present invention, the wall and floor of a cold storage tank are provided, at the inside, with a multilayer sprayed insulation comprising at least a layer of poly-urethane foam sandwiched between two sprayed layers of poly-urethane coating.
[0020] The layer of poly-urethane foam may entirely or partly be made from blocks, but preferably the layer of poly-urethane foam is also sprayed, in which case the entire insulation structure is applied by spraying, which achieves an enormous saving of building time and labour.
[0021] Further, all layers of the insulation structure are made from substantially the same material, so the insulation structure as a whole behaves as a monolithic layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other aspects, features and advantages of the present invention will be further explained by the following description with reference to the drawings, in which same reference numerals indicate same or similar parts, and in which:
[0023] FIGS. 1-6 are cross sections schematically illustrating subsequent steps in a method for building a cold storage tank in accordance with the present invention;
[0024] FIG. 7 schematically illustrates an anchor point.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 schematically illustrates a first step in a building process for building a cold storage tank 1 . In this first step, a concrete floor 11 and concrete walls 12 are built, in a conventional manner. The walls 12 and floor 11 meet in corner areas 13 .
[0026] As a next step, illustrated in FIG. 2 , a first coating 21 is applied at the inner surfaces of the floor 11 and the walls 12 , preferably, as shown, over the entire height of the walls 12 . The first coating 21 is a poly-urethane material (PU), applied by spraying, to a suitable thickness of about 3 mm. The first coating 21 will function as a vapour barrier and gas barrier, and is adapted to be vapour-tight and gas-tight. It is also liquid-tight.
[0027] As a next step, illustrated in FIG. 3 , a first PU foam layer 22 is applied on the inner surface of the coating 21 . The first PU foam layer 22 may be applied over the full height of the walls 12 but, preferably, as shown, the first PU foam layer 22 is applied on the floor part of the coating 21 and up to a certain height on the wall part of the coating 21 .
[0028] Although parts of the first PU foam layer 22 may be applied as individual blocks, the first PU foam layer 22 is preferably applied by spraying, to a suitable thickness in the order of about 150 mm or more. In view of this thickness, the first PU foam layer 22 may actually be applied as a succession of multiple layers. The first PU foam layer 22 will function as an insulation.
[0029] As a next step, illustrated in FIG. 4 , a second PU coating 23 is applied on the inner surface of the first PU foam layer 22 . The second PU coating 23 is applied by spraying to a suitable thickness of about 3 mm. The second PU coating 23 will function as a liquid barrier, and is adapted to be liquid-tight. Although the second PU coating 23 may be applied over the entire height of the walls 12 , this is not always necessary. In case the first PU foam layer 22 extends over only part of the height of the wall 12 , as illustrated, the second PU coating 23 should extend higher than the first PU foam layer 22 and should merge with the first PU coating 21 . Thus, the first PU foam layer 22 is completely encapsulated by PU coating 21 , 23 , in order to assure that the first PU foam layer 22 remains dry.
[0030] As a next step, illustrated in FIG. 5 , a second PU foam layer 24 is applied on the inner surface of the first PU foam layer 22 and the second PU coating 23 , preferably, as shown, over the entire height of the walls 12 . Although parts of the second PU foam layer 24 may be applied as individual blocks, the second PU foam layer 24 is preferably applied by spraying. The second PU foam layer 24 will function as an insulation, together with the first PU foam layer 22 . The combined thickness of the first PU foam layer 22 and the second PU foam layer 24 is suitably in the order of 300 mm or more. Thus, in locations where the first PU foam layer 22 is present, the thickness of the second PU foam layer 24 is reduced, whereas in locations above the first PU foam layer 22 , the thickness of the second PU foam layer 24 preferably is in the order of 300 mm or more. In view of this thickness, the second PU foam layer 24 may actually be applied as a succession of multiple layers.
[0031] As a next step, illustrated in FIG. 6 , a third PU coating 26 is applied on the inner surface of the second PU foam layer 24 , preferably, as-shown, over the entire height of the second PU foam layer 24 . The third PU coating 26 is applied by spraying to a suitable thickness; a thickness of about 4-5 mm is adequate, although a thickness of about 3 mm is usually sufficient. The third PU coating 26 will function as a membrane, and is adapted to be liquid-tight.
[0032] Placing a roof on top of the tank can be done by conventional building methods, so this needs not be explained in further detail. It is noted, however, that the roof, once built, can be sprayed with foam and/or coating PU as well.
[0033] It is possible to place an inner vessel inside the tank 1 thus built, if desired, in which case the cold liquid would be contained in the inner vessel only. However, the tank-in-tank concept has disadvantages, as mentioned above, while further the tank-in-tank concept does not fully utilize the storage capacity of the tank. An important advantage of the tank 1 is that the tank 1 itself is suitable to act as cold liquid container, without a separate inner vessel being necessary. Then, in operation, the cold liquid (not shown for sake of simplicity) would be in contact with the third PU coating 26 . The first PU foam layer 22 and the second PU foam layer 24 together act as thermal insulation between the cold liquid contents and the concrete floor 11 and walls 12 , the first PU coating 21 and the third PU coating 26 (the thickness of which is exaggerated in the figures) also contributing insulative capacity. The third PU coating 26 acts as membrane, protecting the foam 24 against entry by the cold liquid. The first PU coating 21 acts as barrier, protecting the foam 22 , 24 against entry by moist or vapour which penetrates from the surroundings through the concrete floor 11 and walls 12 .
[0034] Under normal circumstances, the second PU coating 23 does not need to come into action. Only in case of a leakage of the third PU coating 26 (and leakage of a possible inner vessel), cold liquid will enter the foam 24 , and will ultimately reach the second PU coating 23 . If the second PU coating 23 would be absent, the cold liquid would be separated from the concrete floor 11 and walls 12 by the first PU coating 21 only. In principle, this separation is sufficient in that no cold liquid will leak through to the concrete; in any case, the first PU coating 21 is liquid-tight. However, the thermal insulative capacity of the first PU coating 21 alone is insufficient for protecting the concrete so that, in such circumstances, the concrete would cool down to a very low temperature; as a consequence, the risks of concrete cracks increase. These risks are largest in the corner areas 13 of the tank 1 , i.e. where the walls 12 and floor 11 meet. The second PU coating 23 , physically separate from the third PU coating 26 , now acts as an additional protection for these corners, keeping the cold liquid away from these corners, maintaining at least the first PU foam layer 22 operational as protective insulation between the concrete and the cold liquid.
[0035] It is noted that it is best to protect the entire floor 11 and at least a part of the walls 12 (depending on the height of cold liquid to be expected in a worst-case scenario) against the very low temperatures, so it is preferred that the second PU coating 23 extends over the entire floor 11 , as illustrated. However, since the potential problems caused by cold liquid are largest in the corner areas 13 , it may, depending on design, be sufficient if the second PU coating 23 (and the first PU foam layer 22 ) is arranged in the corner area only: in that case, the second PU coating 23 would extend beyond the first PU foam layer 22 and merge with the floor part of the first PU coating 21 , as indicated by a dotted line 23 ′ in FIG. 4 , to keep the first PU foam layer 22 encapsulated.
[0036] So, the second PU coating 23 acts as a backup for the third PU coating 26 , having the same mechanical properties as the third PU coating 26 . The second PU coating 23 should be separate from the third PU coating 26 in order to prevent possible failures in the third PU coating 26 from damaging the second PU coating 23 . The second PU coating 23 maintains sufficient insulation (i.e. first PU foam layer 22 remaining dry instead of being drenched with cold liquid) between cold liquid and concrete. It is possible to protect the entire height of the walls 12 in this way, by having the first PU foam layer 22 and the second PU coating 23 extend over the full height of the walls 12 .
[0037] For actually maintaining sufficient insulation, it is preferred that the first PU foam layer 22 is as thick as possible. In a suitable embodiment, the thickness of the first PU foam layer 22 is chosen in the range 150-250 mm, while the thickness of the second PU foam layer 24 is chosen in the range 150-50 mm, the combined thickness being approximately 300 mm.
[0038] The main advantages of the present invention are associated with the building process. Once the concrete floor has been laid and the concrete walls have been erected, the entire thermal protection system can be applied by spraying, using in principle the same material (PU) for all layers. Since only one appplication technique is used, the work can be done by only one construction company (sub-contractor), which is much more efficient than having to coordinate different teams of worksmen performing different works on necessarily pre-defined times.
[0039] Especially, it is an advantage that the thermal protection system does not need to contain any metal parts any more.
[0040] It is also an advantage that all thermal protection layers are made from the same material or material family (poly urethane), so that all layers have identical or at least comparable thermo-mechanical properties such as expansion/ contraction coefficient.
[0041] A material which can very advantageously be used as gas-tight and liquid-tight coating in the present invention is a two-component poly urethane composition which is commercially available from the company TAGOS S. r. L. in Busto Arsizio, Italy, under the brand name IWR ESATEC HR 1000. In the market, this material is also known under the name IWR CRYOCOAT HR, and is commercially available under this name from the company INSU-W-RAPID B.V. in Tilburg, the Netherlands. The coating material is sprayed by means of a mix/spray head, and the components immediately undergo a chemical reaction which is finished after approximately 2 minutes, after which a further layer can be applied. In each spraying cycle, the thickness of the layer to be applied can be set as desired. A suitable value for the thickness of the layers to be applied is in the range of 2-4 mm, but it is possible to apply thinner or thicker layers. It is noted that, in the figures, the thicknesses of the different layers are not shown to scale.
[0042] It is possible to build the thermal protection system over the entire tank as a whole, i.e. to apply one layer over the entire inner surface of the tank, to apply a second layer over the entire inner surface of the tank, etc. In a preferred embodiment of the present invention, it is possible to apply the entire thermal protection system in one section of the tank wall, and then apply the entire thermal protection system in an adjacent section, etc. Suitably, such section may extend over the entire height of the wall and have a width in the order of a few meters. Thus, it is possible to confine the work to one part of the tank while other work may be done in another part of the tank, without the workers being in each others way.
[0043] As regards the insulating foam, to be used for the foam layers 22 and 24 , it is noted that poly-urethane foams are suitable if such foam has a sufficiently high coefficient of thermal stress resistance, indicated as CTSR-value. The CTSR is defined according to the following formula:
CTSR = σ · ( 1 - γ ) E · α · ( T 2 - T 1 )
where:
σ indicates the tensile strength of the foam at −165° C. (kPa; minimum value of all three directions); E indicates the tensile modulus of the foam at −165° C. (kPa; minimum value of all three directions); α indicates the average linear constriction coefficient of the foam from −165° C. up to +21° C. (maximum value of all directions); γ=0.4, estimated value for Poisson's ratio at −165° C. (other values may be used if substantiated by experimental data) T 2 −T 1 = 185° C., estimated value for temperature difference between cold surface and surroundings
Thus, apart from mechanical design criteria, the density and chemical formulation of the foam should preferably be selected in such a way that the CTSR-value is sufficiently high, preferably in the order of approximately 3 or higher.
[0049] It is noted that foam compositions meeting this requirement are commercially available, so it is not necessary here to give more details on the composition.
[0050] Normally, the fixation of the thermal protection system to the floor and the walls of the tank is sufficiently strong to withstand forces that occur due to temperature variations. However, this fixation is based on adhesion between PU coating 21 and concrete, and it may be preferred to provide the walls 12 of the tank, and perhaps also the floor 11 , with anchor points which offer a mechanical fixation of the PU to the concrete. Such anchor point should combine mechanical strength with little or no thermal conduction.
[0051] FIG. 7 is a cross section illustrating an embodiment of a suitable anchor point 100 in accordance with the present invention. The anchor point 100 comprises a bush 110 , fixed in the concrete of the wall 12 , either by being embedded in the concrete when the concrete was being poured into a formwork or by being screwed into the concrete after the concrete has hardened. A suitable material for the bush 110 is glass fiber reinforced polyester, epoxy or phenolic resin which are materials known per se.
[0052] The bush 110 is provided with a threaded bore, into which a screw rod 120 is screwed, so that the screw rod 120 extends substantially perpendicularly with respect to the inner surface of the wall 12 . The screw rod 120 may be made from the same material as the bush 110 .
[0053] After the first PU coating 21 and the first PU foam layer 22 have been applied to the wall 12 , a first retaining plate 131 is screwed onto the screw rod 120 , which first retaining plate 131 may be made from the same material as the screw rod 120 . The first retaining plate 131 is screwed tight against the first PU foam layer 22 , thus providing a mechanical fixation of the combination of the first PU coating 21 and the first PU foam layer 22 . Then, the second PU coating 23 is applied on the first PU foam layer 22 , over the first retaining plate 131 .
[0054] Then, after the second PU foam layer 24 has been applied, a second retaining plate 132 is screwed onto the screw rod 120 , which second retaining plate 132 may be made from the same material as the first retaining plate 131 . The second retaining plate 132 is screwed tight against the second PU foam layer 24 , thus providing a mechanical fixation of the second PU foam layer 24 , while also adding to the fixation of the underlying layers. Then, the third PU coating 26 is applied on the second PU foam layer 24 , over the second retaining plate 132 .
[0055] If desired, if it is considered that the second retaining plate 132 suffices, the first retaining plate 131 may be omitted.
[0056] If desired, the retaining plate(s) may be screwed so tight that the underlying foam layers 22 and 24 are compressed.
[0057] It should be clear to a person skilled in the art that the present invention is not limited to the exemplary embodiments discussed above, but that several variations and modifications are possible within the protective scope of the invention as defined in the appending claims.
[0058] For instance, the vessel of the tank 1 , i.e. floor 11 and walls 12 , are not necessarily made from concrete; in an alternative embodiment, they may be made from a suitable metal. Since metal is vapour-tight and gas-tight, the first PU coating 21 may be omitted in such embodiment, but the first PU coating 21 may also be maintained. | A double containment storage tank, suitable for storing cold liquids, is provided with a non-metallic thermal protection system. The storage tank can include a first vapour-tight and gas-tight PU coating applied by spraying on the inner surface of the floor and walls of the tank; a first insulation PU foam layer arranged on the inner side of the first coating; a second liquid-tight PU coating applied in at least the bottom corner sections of the tank by spraying on the inner surface of the first foam layer; a second insulation PU foam layer arranged on the inner side of the second coating; and a third liquid-tight PU coating arranged by spraying on the inner side of the second foam layer. | 5 |
RELATED APPLICATIONS
This application is related to and claims the benefit and priority of U.S. Provisional Application Nos. 61/449,685 and 61/449,686, both filed on Mar. 6, 2011, which are hereby incorporated by reference.
TECHNICAL FIELD
The present application is directed to a light emitting diode (LED) device implemented on a wafer cover layer and provided with features permitting efficient and repeatable manufacture of the same.
BACKGROUND
A light emitting diode (LED) is a semiconductor device that is configured to receive electrical power or stimulation and to output electromagnetic radiation, commonly in the visible range of the spectrum (light). Portions of a LED comprise doped semiconductor materials that operate to combine charge in a way that releases said light energy from the body of the LED material. This effect is sometimes referred to as electroluminescence. The output energy or light is determined by the materials and operating conditions of the LED, including the energy band gap of the LED material and the electrical biasing of the LED.
Light emitting diodes (LEDs) compare favorably to other sources of light and are especially useful in certain applications and markets. For example, LED lighting generally provides advantages with respect to energy efficiency, compact and rugged and long-lasting design and form factor, and other features. LED lighting compares favorably with other sources in the amount of light energy generated in the visible electromagnetic spectrum compared to the infra-red or heat energy wasted by the light source. In addition, LED lights include fewer environmentally damaging components when compared to other light forms, and therefore provide better compliance with restrictions on hazardous substances (RohS) regulations.
That said, conventional LED devices can be relatively costly to manufacture by some metrics when compared to other light sources. One reason for this is the exacting packaging requirements for manufacturing LEDs. LED packaging calls for proper clean conditions, micro-fabrication facilities similar to other semiconductor manufacturing operations, sealing requirements, optical requirements, the use of phosphor in LED applications, as well as packaging that is designed to handle the conduction of heat generated in the devices.
Conventional LED packaging includes silicon (Si) or Ceramic based carrier substrates. The LEDs can be mounted on the carrier, or alternatively the many LEDs can be mounted on a wafer of the carrier and the LEDs are singulated at the end of the packaging process. The wafer based approach is termed wafer level assembly packaging (WLP). However, these conventional techniques require the use of a carrier substrate to support the LED, which can double the cost of making and packaging the LED device. In addition, the carrier substrate greatly increases the thermal resistivity of the device and adversely affects its heat removal characteristics.
Accordingly, there is a need for LED devices that do not suffer from some or all of the above problems.
SUMMARY
A light emitting diode (LED) device and packaging for same is disclosed. In some aspects, the LED is manufactured by epitaxial growth or other chemical or physical deposition techniques of a plurality of layers. Certain layers act to promote mechanical, electrical, thermal, or optical characteristics of the device. The device avoids design problems, including manufacturing complexities, costs and heat dissipation problems found in conventional LED devices. Some embodiments include a plurality of optically permissive layers, including an optically permissive cover substrate or wafer stacked over a semiconductor LED and positioned using one or more alignment markers.
Some embodiments are directed to a light emitting device, comprising a semiconductor LED including doped and intrinsic regions thereof; a first surface of said semiconductor LED being metallized with an electrically conducting metallization layer over at least a portion of said first surface; an optically permissive layer proximal to a second surface of said semiconductor LED, said first and second surfaces of said semiconductor LED being on opposing faces thereof; an optically definable material proximal to or within said optically permissive layer that affects an optical characteristic of emitted light passing there through; and an optically permissive cover substrate covering at least a portion of the above components.
Other embodiments are directed to ways of making such a light emitting device or a group of devices on a wafer in a manufacturing context. Specifically, embodiments are directed to a method for making a light emitting device, the method comprising forming a plurality of doped layers in a light emitting device (LED) disposed on an optically permissive layer; forming a recess in said LED so as to allow electrical contact with a first doped layer of said LED at a depth of said first doped layer in said LED; metallizing at least a portion of a face of said LED so as to form a metallization layer provide electrical contact with said first doped layer and a second doped layer of said LED proximal to said face thereof; and using an optically permissive adhesive to mechanically secure said optically permissive layer to an optically permissive cover substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and advantages of the present concepts, reference is made to the following detailed description of preferred embodiments and in connection with the accompanying drawings, in which:
FIG. 1 illustrates a semiconducting LED layer above a sapphire layer according to the prior art;
FIG. 2 illustrates a semiconducting LED layer with a cavity etched in a portion thereof on a sapphire layer according to the prior art;
FIG. 3 illustrates metallization of a LED device according to some aspects;
FIG. 4 illustrates a top view of an exemplary LED device;
FIG. 5 illustrates a cross sectional view of another exemplary LED device;
FIG. 6 illustrates an LED device 60 in a top view thereof;
FIG. 7 illustrates another exemplary cross sectional view of a LED device;
FIG. 8 illustrates an exemplary LED device comprising a passivation layer;
FIG. 9 illustrates an exemplary LED device having a shaped an optionally mirrored or metallized passivation layer;
FIG. 10 illustrates another exemplary LED device;
FIG. 11 illustrates yet another embodiment of a LED device; and
FIG. 12 illustrates how more than one LED device can be manufactured on a single manufacturing platform or wafer.
DETAILED DESCRIPTION
Modern LED devices are based on semiconducting materials and their properties. For example, some LEDs are made using gallium nitride (GaN) which is a type of bandgap semiconductor suited for use in high power LEDs. GaN LEDs are typically epitaxially grown on a sapphire substrate. These LEDs comprise a P-I-N junction device having an intrinsic (I) layer disposed between a N-type doped layer and a P-type doped layer. The device is driven using suitable electrical driving signals by way of electrodes or contacts coupled to the N and the P type portions of the LED. Electronic activity causes the emission of visible electromagnetic radiation (light) from the intrinsic portion of the device according to the electromotive force applied thereto and configuration of the device.
The embodiments described and illustrated herein are not meant by way of limitation, and are rather exemplary of the kinds of features and techniques that those skilled in the art might benefit from in implementing a wide variety of useful products and processes. For example, in addition to the applications described in the embodiments below, those skilled in the art would appreciate that the present disclosure can be applied to making and packaging power integrated circuit (IC) components, radio frequency (RF) components, micro electro-mechanical systems (MEMS), or other discrete components.
FIG. 1 illustrates a LED device 10 such as those described above, having a GaN layer 100 , commonly referred to as the LED, disposed on a sapphire layer 110 . The device of FIG. 1 is usually processed using some semiconductor micro fabrication techniques. In some examples, portions of the LED (GaN layer) are etched away or removed using techniques known to those skilled in the art. Other applications of conducting and non-conducting layers are applied to such a base design, along with channels and vias for various functionality as will be described below.
FIG. 2 illustrates a LED device 20 like the one shown in FIG. 1 where a GaN layer 200 is disposed above a sapphire layer 210 . A recess or groove or channel 202 is etched into a portion of the GaN layer 200 .
It should be appreciated that GaN type LEDs are not the only kind of LED materials that can be employed in the present discussion, but that the present description is merely illustrative so that those skilled in the art can appreciate some preferred embodiments and methods for making and designing the present LEDs. Similarly, in the following preferred and exemplary illustrations, it is to be understood that many other similar and equivalent embodiments will be apparent to those skilled in the art and which accomplish substantially the same result. This is true as to variations in the geometry, layout, configurations, dimensions, and choice of materials and other aspects described in the present examples. Specifically, certain described elements and steps can be omitted, or others can be substituted or added to that which is described herein for the sake of illustration without materially affecting the scope of the present disclosure and inventions.
FIG. 3 illustrates the result of metallization of the surface of the GaN layer 300 of the device of FIG. 2 using a step of applying a suitable metallic layer 320 to portions of LED device 30 . Here, as before, a GaN layer 300 is disposed on a sapphire layer 310 . In an embodiment, the GaN layer 300 comprises a P-I-N junction having strata therein including a P-type doped layer 301 that is proximal to the bulk surface of the GaN layer 300 and distal from the sapphire layer 310 , a N-type doped layer 303 within GaN layer 300 that is proximal to the sapphire layer 310 , and an intrinsic (I) semiconductor layer 305 in the middle, between the P and N type layers 301 and 303 . In operation, electrical biasing of the P-type layer 301 against the N-type layer 303 causes photon emission from intrinsic layer 305 .
As mentioned before, a recess 302 is etched into a portion of the surface of GaN layer 300 . The depth of recess 302 may be shallow or deep, and is commensurate with the thickness of the GaN layer 300 and the P-I-N strata therein.
Furthermore, a metallization layer 320 is applied to at least a portion of the surface of the GaN layer 300 . The metallization layer 320 can extend to cover both the bulk surface of the GaN layer 300 as well as areas that became exposed in recess 302 after it was etched into the bulk of the GaN layer 300 .
In an embodiment, the recess 302 is created sufficiently deep so as to allow contact between an electrical connection and the N-type layer 303 to drive the LED. In this way, a set of contacts can be applied to the N-type layer 303 and the P-type layer 301 to drive or excite the LED device 30 . Current can thus generally flow from a conducting electrode coupled to the N-type layer 303 to another conducting electrode coupled to the P-type layer 301 . The metal can be Al, Au, Ag, Cu or other conducting material. It should be noted that state of art method of electrode formation includes depositing a SiO2 or other electrically insulating and optically transparent layer on top of the P and exposed N layers. This layer is then exposed using lithography and chemical etching to reveal the layers in specific locations which become the contact pads. The metal is then deposited on top the insulating layer and electrical contact is facilitated in the exposed portions. Other state of art techniques include selective doping of contact areas to reduce electrical resistivity. In an embodiment the top metal layer extends over the contact openings in the insulating layer to cover substantially all the unetched parts of the LED as shown in FIGS. 3 and 4 . In another embodiment, the metal is designed to have contact pads, areas where the metal has a substantially continuous area greater than 100×100 microns. The extended metal covering provides a mirror for reflecting the light towards the Sapphire. The metal layer for providing the mirror is preferably Al, or Ag. The metal contact can have a plurality of metal constituents each with a specific purpose, e.g. light reflection, adhesion to the GaN layers or matching the work function of the GaN layers. In another embodiment, the metal cover can be composed of two or more, electrically isolated parts. One part(s) is electrically connected to the P layer and provides electrical contact as well as thermal contact, and the other part(s) provide optical reflection and thermal connection.
FIG. 4 illustrates a top view of an exemplary LED device 40 . The cross sectional line 420 is substantially corresponding to the side view shown in FIG. 3 . The drawing shows an example of features arranged on a face 400 of the device configured to have a convoluted or fingered or patterned layout 410 . A bottom metal pad area defines an alignment tolerance in the assembly of the LED and creation of the electrical contacts. Hence in one embodiment it is taught to increase the pad size to 150×150 microns to relax the required tolerances. The thickness of the metal can be 0.5-5 microns, but this example is not given by way of limitation.
FIG. 5 illustrates a cross sectional view of an exemplary LED device 50 . The device 50 includes the stated LED semiconducting layer or layers 500 as discussed above, along with etched recess 502 and metallization areas 520 . The LED (e.g., GaN) layer 500 is disposed on a sapphire layer 510 as before.
Here, an optically transparent or transmissive adhesive layer 530 is placed against the opposing side of the sapphire layer 510 than the LED material 500 (meaning, one face of the sapphire layer 510 is proximal to the LED material layer 500 and the other opposing face of sapphire layer 510 is proximal to the transparent adhesive layer 530 . The transparent adhesive layer 530 may be composed of silicone or some other suitable adhesive, which may also be photo definable material that can provide adhesion or epoxy quality to bond or mechanically couple elements of LED device 50 . In an additional embodiment, the adhesive is index matched to the Sapphire to reduce optical reflections at the interface.
Within, or contiguous to transparent adhesive layer 530 is a region containing phosphor and/or quantum dot material (QD) 535 . In operation, photons emitted from LED layer 500 travel through said sapphire layer 510 and pass through the optically transparent layer 530 and the region containing the phosphor and/or quantum dots 535 . This causes color (wavelength) control and emission of selective desired light out of the LED device as further described herein.
One, two or more alignment marks 540 are provided on or in the transparent adhesive layer 530 and are used to align the LED body over a cover substrate 550 sheet and generally in an extended wafer structure during manufacture. The cover substrate 550 provide structural presence and mechanical coupling for elements of the LED device 50 . The cover substrate 550 is also transparent or optically transmissive to light in the wavelength emitted by LED layer 500 or by the combination of the LED layer 500 and the phosphor material.
In some embodiments, an optical lens 560 may be placed on the cover substrate 550 substantially above the body of the LED emitting portions of the device 50 . The lens 560 can act to spread, diffuse, collimate, or otherwise redirect and form the output of the LED.
The system may be coupled to other optical elements as would be appreciated by those skilled in the art. One or more optical lens or assembly of optical lenses, Fresnel layers, filters, polarizing elements, or other members can be used to further affect the quality of the light provided by the LED device.
FIG. 6 illustrates an LED device 60 in a top view thereof. The device includes substantially the elements described above with regard to FIG. 5 , including an LED emitting body 600 and positioning or alignment markers 640 , lens 660 , arranged on a patterned cover substrate 610 . In an embodiment, the LED is positioned with respect to said alignment marks. Between adjacent LEDs on a wafer there is a space of, e.g., 50-1000 microns for subsequent processing and dicing of the LEDs.
The LEDs are individually assembled on a carrier wafer, with the sapphire layer facing the carrier wafer layer. The carrier wafer layer is of optically transparent material such as glass or plastic as described above. The cover can include other optical components such as lenses or light diffusing structures or light guiding structures. As mentioned, the phosphor or quantum dot layers enable the conversion of the light generated by the LED to other colors. The most common is the use of phosphor to enable White light from a blue LED. In one embodiment the lens shape is created by the surface tension of a drop of polymer or silicone material. In another embodiment the lens is created by hot embossing of a polymer which is applied to one side of the carrier wafer. The carrier wafer may be further patterned to create specific drop shapes, sizes and desired surface qualities.
FIG. 7 illustrates another exemplary cross sectional view of a LED device 70 . Standoff structures 737 , made of a suitable mechanically supportive material are created on the carrier wafer. The standoff structures 737 can comprise a thermoplastic material and created by embossing or injection molding, or the structures can be made by applying a layer of photo definable material such as polyamide or solder mask and exposing the material to light using a suitable mask. The standoff structures 737 can be used to encase the QD or phosphor material 735 , or alternatively to provide a cavity for the material deposition. The other elements of LED device 70 are similar to similarly numbered elements described above.
FIG. 8 illustrates a LED device 80 similar to those described above. Here, a passivation layer 870 has been applied to surround certain portions of the device around LED semiconducting layer 800 , metallization layer 820 , and sapphire layer 810 . The passivation layer 870 can comprise a non conductive layer and can be composed of SiO2, SiN, AlN, Al2O3 or an organic material such as epoxy, or electrophoretic deposited paint as used in the car industry, or spray coated. In one embodiment, the passivation layer 870 has a thickness that ranges from 1 to 40 microns, depending on the material and required electrical passivation level. In an embodiment, the passivation layer 870 covers in a conformal manner the space between LEDs during manufacture. In another embodiment the spacing between the LEDs is not covered, or alternatively is revealed in a mechanical process such as dicing. The other elements of LED device 80 are similar to similarly numbered elements described above. In an additional embodiment the passivation layer can be designed to be reflective by incorporating appropriate material particles within such as ZnO.
FIG. 9 illustrates an exemplary LED device 90 having a shaped an optionally mirrored or metallized passivation layer 970 to enhance the performance of the device. The passivation at the diode side can be patterned in a manner to provide for example optical reflectivity by angling or shaping the edges 975 of passivation layer 970 . The patterning of passivation layer 970 can be done using a mechanical dicing system with special blade or via chemical etching. In one embodiment a thermally conductive layer such as SiN or AlN is preferred to minimize the thermal conductance of the LED device package. The other elements of LED device 90 are similar to similarly numbered elements described above.
FIG. 10 illustrates another exemplary LED device 1001 . Similarly numbered elements discussed earlier are common to or similar to those in this exemplary embodiment. Here, contact holes are drilled, in one embodiment by use of a laser, through the passivation layer until reaching the metal pad and silicon substrate. If SiN or SiO2 are used, a plasma etch can also be used to create the contact holes. If a laser is used, the laser can either stop at the metal pad (blind via) or cut through the pad and the electrical connection would then be done using the pad thickness. If the passivation layer is photo definable, than a lithography step can expose the pads. In another embodiment the organic passivation layer is etched using a hard mask made of inorganic material such as a thin metal or insulating layer and then using plasma etch to remove the organic material.
It is noted that passivation layer 1075 is cut or etched away as stated above so as to provide conducting access at least to the N-type semiconductor proximal to laser drilled recess 1002 and the P-type semiconductor proximal to portion 1074 of metallization layer 1020 . The passivation layer is also removed to enhance the heat conduction of the LED. Hence to optimize the heat conductance, a maximal contact should be made between the metal and metal pads on the LED and the metal layer. This is done by opening the largest possible area on the passivation layer and preferably greater than 80%. If the LED is designed with a thermal pad structure then the P connection can be connected to thermal and P pad or alternatively three metal connections are facilitated, N, P and thermal. In another embodiment, the passivation is also removed in areas where there is no metal layer, only the electrically insulating layer. This can occur, if instead of the LED described previously, a standard LED is used in which the metal covers only a small portion of the top of the LED. In this case the metal layer deposited in this stage will provide the heat removal and light reflection. In this manner, the exposed portions of the LED will extend beyond the metal areas. The newly deposited metal will again cover substantially all of the LED structure. In another embodiment, if the electrical passivation layer is optically reflecting and heat conducting the layer may be maintained and the metal passivation will cover substantially all the LED area but will make a direct connection to the LED metal pads, and in other areas the connection layers would be through the passivation layer, i.e. the layer stack would be, LED, LED passivation layer, packaging passivation layer which provides low thermal resistance and light reflection, packaging metal for heat conduction.
FIG. 11 illustrates yet another embodiment of a LED device 1101 . Here, a metal seed layer 1177 is applied to the passivation layer 1170 . The metal seed layer 1177 may be composed of any of titanium, chrome, nickel, palladium, platinum, copper or combinations of these. In a preferred embodiment, if the metal layer serves to reflect light from the LED towards the Sapphire, then the first metal seed layer should be a suitable light reflecting material such as Al, or Ag. The seed layer can be thickened using sputtering over the initial seed layer. In one embodiment the seed layer is patterned using electrophoretic deposited photo resist, spray coating resist, or thick resist, in one embodiment greater than 50 microns. The resist is patterned to create the electrical routing connections and under bump metallization (UBM). After patterning the resist, a thick metal layer, in one preferred embodiment between 10 and 40 microns is plated in the defined patterns. The resist is removed and the bare seed layer is etched, in one non-limiting embodiment by using a wet metal etch. In one embodiment a solder mask is applied to form such a layer. In operation, the layer 1177 provides enhanced electrical conductivity between external electrical components and the metallization layer or conducting pads of the device. This layer 1177 also provides maximum enhanced heat removal from LED layer 1100 .
FIG. 12 illustrates how more than one LED device like those described above can be manufactured on a single manufacturing platform or wafer. Here, two LED units 1201 and 1202 are electrically connected in the metallization step of manufacturing the units. The LEDs can be connected in parallel, serial or combinations of such connections. These can be cut apart or in other embodiments can be left arranged on the substrate without cutting so as to form a multi LED unit or light source. In addition to LED devices, this approach can support placement and electrical connection of differing LEDs, or other electronic components including integrated circuit LED driver, capacitors, diodes, anti static discharge diodes, temperature sensors, color sensors, image sensors, fuses and other similar elements.
The present invention should not be considered limited to the particular embodiments described above, but rather should be understood to cover all aspects of the invention as fairly set out in the present claims. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable, will be readily apparent to those skilled in the art to which the present invention is directed upon review of the present disclosure. The claims are intended to cover such modifications. | A light emitting diode (LED) device and packaging for same is disclosed. In some aspects, the LED is manufactured using a vertical configuration including a plurality of layers. Certain layers act to promote mechanical, electrical, thermal, or optical characteristics of the device. The device avoids design problems, including manufacturing complexities, costs and heat dissipation problems found in conventional LED devices. Some embodiments include a plurality of optically permissive layers, including an optically permissive cover substrate or wafer stacked over a semiconductor LED and positioned using one or more alignment markers. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Our invention relates to storage systems, and more particularly addresses storage for products used in a residential laundry area. Specifically, the present invention provides storage for most laundry products in a container system configured to be supported by an appliance or appliances.
2. Discussion of the Prior Art
A variety of products are used in home laundry areas. Specialized storage apparatus for these products is limited in the prior art. U.S. Pat. Nos. 5,411,164 and D371,014,Paul and Barbara Smith, commonly assigned, address this need in a unit deriving lateral stability from two adjacent appliances while the weight is supported on the floor by legs or the walls of a pedestal. While this concept works well, the supporting structure, packaging, and retail shelf space requirements add to the cost and affect merchandising of the unit. Therefore, there is a need to provide a suitable alternative that can be manufactured and sold at lower cost.
SUMMARY OF THE INVENTION
A container system for laundry products, trash, and the like is supported by one or more laundry appliances. A container comprising the container system may be approximately equal in length to the front to back depth of an appliance, and about 6" to 9" in width and 12" to 15" in height. The container may be open topped with a cover provided, or slide in and out of a container housing. Rollers may be provided for easier operation of a slidable container. The container system further comprises mounting means communicating between the container or container housing and the appliance or appliances to support the container or container housing in side by side relationship with one appliance or between two appliances, whereby the cover closing the container or the top of the container housing is substantially flush with the top work surfaces of the adjacent appliances or appliances, effectively forming a continuous work surface. While simple mechanical fasteners such as sheet metal screws metal screws may be employed, a less invasive mounting system may be provided that requires little or no use or tools.
Mounting means preferably comprises one or more container supporting brackets placed between the top panel and body of an appliance cabinet, an outwardly projecting flange near the top of one or both side of the container or container housing communicating with the adjacent appliance or appliances, Velcro and adhesive fasteners, or other suitable alternatives. Construction of the container system is preferably of molded plastic for economy, durability, and resistance to laundry agents. The container may be assembled from multiple panels and so be efficiently packaged in flat cartons of minimal size. Alternatively, containers may be injection molded to nest within one another for efficient shipping and merchandising.
Objectives
Our invention provides a system for storing laundry products in the location where needed, i.e. adjacent to the appliances in which they are used. An important objective of the invention is to provide the utility described with a minimal and efficient structure thereby lowering the manufacturing, packaging, shipping, and merchandising costs and thus the cost to the consumer. Preferably the system requires minimal packaging and shelf space in the retail environment. Further objectives include ease of installation and reliability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a container storage system in accordance with one embodiment of the current invention, shown in one intended environment.
FIG. 2 is a partial front-cross sectional detail view of the container system shown in FIG. 1.
FIG. 3 is a partial perspective view of a second embodiment of the container system wherein a flange overlapping an appliance comprises the mounting means.
FIG. 4 is a partial front cross-sectional detail view of the container system of FIG. 3 showing the overlapping flange.
FIG. 5 is a front cross-sectional detail view of a modified container system with bracket between the top panel and the body of an appliance housing.
FIG. 6 is a perspective view of another embodiment of the container system in accordance with the present invention wherein the container slides in and out of a container housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, an embodiment of our storage system 10 is showing in one intended environment. A clothes washer 11 and dryer 12, as well as a wastebasket 13 under the container system are shown for illustration purposes only and are not in themselves part of the invention. A container 14 is supported by mounting means placed between the top panel 15 and the body 16 of the dryer housing, as will be described shortly. The open top of the container 14 is closed by a cover 17, effectively providing a continuous work surface with the two appliances 11, 12. The horizontal depth 14d of the container 14 is compatible with the depth 11d of the appliances. Preferably, the height 14h or the container 14 is approximately 12" to 14" and the width 14w of is approximately 6" to 9" to accommodate many common laundry products in their packing or to allow powdered products to be poured into the container. Space is available under the storage system 10 for the wastebasket 13, a roll out unit with additional storage, hamper, or the like.
FIG. 2 is a front cross-sectional detail view at Sec. A--A of FIG. 1 detailing mounting means for mounting the container on one or both appliances 11, 12. Typically, the top panel 15 of a home laundry appliance is held in position on the body 16 of the appliance housing by anchors at the back of the panel and spring clips across the front of the panel. Thus, there is an intersection 18 along the sides of the appliance between the top panel 15 and body 16 that can be opened slightly against the resistance of the spring clips. In the embodiment shown in FIG. 2, a first leg 21 of a "T" shaped mounting bracket 20 is inserted between the top panel 15 and body 16. A second leg 22 extends vertically to engage a channel 24 along sidewall at the top of the container 14. A third leg 23 extends downwardly. The "T" shape provides a surface for tapping on the bracket 20 to insert it at the intersection 18 without needing to open the appliance top. Spacer means 25 having adhesive coatings can be used to adhere the bracket 20 to the side of the appliance body and maintain the clearance required for the second leg 22 to engage the container 14. Additional adhesive spacer means 27 can be used near the bottom of the container 14 as required. The spacer means 25, 27 also reduce the potential for noise from vibration. Aluminum extrusions, being strong, rigid, and rustproof, are preferred for fabricating the brackets 20. Spreader means 28 fixing the width between the sidewalls of the container 14 is also shown in FIG. 2, fastened by a screw 26. The cover 17 preferably having stiffening and alignment ribs 29 is shown in place on the container 14.
FIG. 3 shows a second embodiment in perspective wherein the container 14 is supported by a flange 31a extending outwardly from the sidewall of the container to overlap the top of the adjacent appliance 12 to provide support. The flange 31a does not extend the full length of the container 14, leaving an end 32a of the container without a flange so as to accommodate the control head 33 of the typical appliance. If this allowance is made at both ends 32a, 32b, the container system 10 may be reversible and thus useable on either side of an appliance. As an option, a second flange 31b is shown on the other sidewall of the container 14 to overlap a second adjacent appliance. A rollout storage unit 34 shows another possibility for good use of the space below the container system 10.
FIG. 4 is a front cross-sectional detail view of the container system 10 of FIG. 3 showing the flange 31a overlapping and engaging the top 15 of the appliance 12. Preferably, the flange 31a tapers as it extends outwardly to concentrate strength where needed. Adhesive spacer means 25 is employed between the sidewall of the container 14 and the appliance 12 to prevent outward movement of the container that would disengage the flange, and also eliminates vibration noise.
FIG. 5 shows a front cross-sectional view of modified version of the embodiment of the container system shown in FIGS. 1 and 2. A thin flange 51, molded or otherwise attached to the side of the container 14, is positioned at the intersection of the top 15 and body 16 to resist downward movement. Adhesive spacer means 52 is used to resist outward movement of the container and reduce noise from vibration. A removable divider panel 53 for dividing the interior of the container 14 into multiple compartments is shown. Ears 54 on the divider panel engage notches 55 at the top of opposing pairs of dividers ribs 56 on the sidewalls of the container 14, thereby serving the function of spreader means 28 in shown FIG. 2.
FIG. 6 is a perspective view of a container system 10 in accordance with the present invention wherein the container 14 slides in and out of a container housing 62. Preferably, rollers 65 are disposed between the container housing 62 and container 14 to ease operation. A handle 63 is preferably provided. A divider 64, which may be either fixed or movable, is shown in the interior of the container 14. The mounting means of such a container system of the appliance 12 may be one of those previously discussed, with some additional consideration for the shift in weight distribution that occurs when the container 14 is in the outward position shown in FIG. 6. This roll out arrangement is especially useful with front-loading appliances that may have a continuous countertop or the like above them precluding the use of a top opening unit.
Thus, various embodiments of our container system supported by one or more appliances have been shown and described. Although certain examples and advantages have been described, other modifications, mounting means, and additional advantages may become apparent to those skilled in the art from the disclosures herein. For example, other mounting means such as Velcro and adhesive fasteners may be used. Also, the container system may be used in other environments, such as kitchen or garage, attached to one or more appliances including cabinetry. Therefore, the invention is not to be limited except in the spirit of the claims that follow. | A container system is supported by one or more laundry appliances. The container may have an open top with a cover provided, or slide out of a container housing. The container system further includes mounting structure between the container or container housing and the appliance or appliances to support the container or container housing in side by side relationship with one appliance or between two appliances, so that the cover closing the container or the top of the container housing is substantially flush with the top work surface of the adjacent appliance or appliances, effectively forming a continuous work surface. | 3 |
RELATED APPLICATIONS
[0001] This application is a divisional of and claims priority to and the benefit of U.S. patent application Ser. No. 11/088,456, filed Mar. 24, 2005. The entire contents of the foregoing are hereby incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
[0002] Personal video recording functions allow a user to rewind, fast forward, pause, and play video data in slow motion. The foregoing functions can be implemented by displaying selected pictures from the pictures forming the video data.
[0003] Many video compression standards introduce data dependencies between pictures in a video. As a result, some pictures in the video are data dependent on other pictures in the video. Pictures that are data dependent on other pictures are decoded after the other pictures.
[0004] The compression standards typically restrict the permissible data dependencies between pictures in the video data, such that the decoding order has some relationship to the standard video display order. However, the decoding order can be vastly different from the rewind and fast forward order.
[0005] Due to copyright and security concerns, video data is increasingly encrypted. The video data is usually transmitted in transport packets. The transport packets include a header and payload. The payload includes encrypted video data.
[0006] The use of encrypted data complicates personal video recording functions. Certain personal video recording functions can display pictures in a different order from the standard playback order. In standard playback, the video data stream is accessed and consumed in generally a continuous manner. During a number of personal video recording functions, the video data is displayed in a non-continuous order. The encryption complicates accessing the video data at the appropriate intervals.
[0007] Further limitations and disadvantages of conventional and traditional systems will become apparent to one of skill in the art through comparison of such systems with the invention as set forth in the remainder of the present application with reference to the drawings.
SUMMARY OF THE INVENTION
[0008] Presented herein are system(s), method(s), and apparatus for embedding personal video recording functions at the picture level, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.
[0009] These and other advantages and novel features of the present invention, as well as details of illustrated examples embodiments thereof, will be more fully understood from the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a block diagram describing encrypted and compressed video data;
[0011] FIG. 2 is a block diagram describing an exemplary circuit for decoding video data in accordance with an embodiment of the present invention;
[0012] FIG. 3 is a block diagram describing a memory storing encrypted GOPs;
[0013] FIG. 4 is a flow diagram for the fast forward function in accordance with an embodiment of the present invention;
[0014] FIG. 5 is a flow diagram for the rewind function in accordance with an embodiment of the present invention; and
[0015] FIG. 6 is a block diagram of a picture storing commands for effectuating a personal video recording function in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIG. 1 illustrates a block diagram of an exemplary Moving Picture Experts Group (MPEG) encoding process of video data 101 , in accordance with an embodiment of the present invention. The video data 101 comprises a series of pictures 103 . Each picture 103 comprises two-dimensional grids of luminance Y, 105 , chrominance red C r , 107 , and chrominance blue C b , 109 , pixels.
[0017] The pictures 103 can be compressed using a variety of compression techniques that take advantage of both spatial and temporal redundancies. Additionally, the pictures 103 include a header 103 ( a ) with parameter information. The pictures 103 are grouped together into a data structure known as a group of pictures (GOP) 123 . The GOP 123 also includes additional parameters further describing the GOP. A number of GOPs 123 together form a video sequence 125 .
[0018] Due to copyright and security concerns, video data is increasingly encrypted. Accordingly, the video sequence 125 can be encrypted using any one of a variety of schemes. The encrypted video sequence 128 is then packetized into what are known as transport packets 130 . The transport packets 130 are fixed length packets and comprise headers 130 a and payloads 130 b . For example, the transport packets used by the MPEG standards are 188 bytes, including a four byte header and a 184 byte payload. The payload 130 b carries the encrypted video sequence 128 .
[0019] FIG. 2 illustrates a block diagram of an exemplary circuit for decrypting and decoding the encrypted video data, in accordance with an embodiment of the present invention. Data is received and stored in a buffer 203 within Synchronous Dynamic Random Access Memory (SDRAM) 201 . The data can be received from either a communication channel, including, for example, a satellite or cable communication link, or memory, including, for example, a hard disc or DVD.
[0020] The data output from the buffer 203 is then passed to a data transport processor 205 . The data transport processor 205 demultiplexes the transport stream into packetized elementary stream constituents, and passes the audio transport stream to an audio decoder 215 and the video transport stream to a video transport processor 207 .
[0021] The video transport processor 207 extracts the payload 130 b from the stream of transport packets 130 , thereby recovering the encrypted video 128 . A decryption engine 208 receives and decrypts the encrypted video 128 recovering the video sequence 125 and writes the video sequence 125 to a compressed data buffer 218 .
[0022] A video decoder 209 decompresses pictures 103 of the video sequence 125 from the compressed data buffer 208 and writes the pictures 103 to frame buffers 219 . The display engine 211 scales the picture 103 , renders the graphics, and constructs the complete display.
[0023] The circuit also supports personal video recording functions, such as fast forward, and rewind, to name a few. The circuit includes a receiver 221 for receiving a signal from a control panel 223 . The control panel can comprise a variety of input devices, such as a hand-held infrared or radio remote control unit, or a keyboard. The control panel 223 can either form a portion of the circuit or be separate from the circuit.
[0024] The user can initiate personal video recording functions from the control panel. The control panel 223 provides a signal corresponding to the particular personal video recording function to the controller 216 via receiver 221 .
[0025] During standard playback, the pictures 103 are displayed in the order of capture by video camera during recording. Additionally, in MPEG-2, during standard playback, the pictures 103 are decoded in the order that the pictures 103 are received. Thus, the video data can be written to the buffer 203 in the order that the video data is received. The data transport processor 205 , video transport processor 207 , and decryption engine 208 can process the video data by fetching the video data from sequential addresses from buffer 203 . Similarly, the video decoder 209 decodes the video data by fetching the video data from sequential locations in the compressed data buffer 218 . This can be implemented by use of a pointer.
[0026] During fast forward and rewind operations, the video data is not necessarily decoded in the order that the video data is received. In contrast, during fast forward and rewind, the decoding order for the pictures may skip certain pictures. During the rewind operation, the decoding order for the pictures may reverse direction.
[0027] Accordingly, the controller 216 fetches encrypted GOPs 123 from the buffer 203 . The decryption engine 208 decrypts the fetched encrypted GOP 123 and writes the GOP 123 to the compressed data buffer 218 . The controller 216 creates a picture table 230 for the GOP 123 . The picture table 230 indexes the pictures 103 of the GOP 123 in the compressed data buffer 218 , indicating information such as the type of picture 103 , and the address in compressed data buffer 218 from which the picture 103 starts.
[0028] The video decoder 209 uses the picture table 230 to locate particular pictures. Additionally, the controller 216 writes commands into the picture 103 . In certain embodiments, the commands can be written into user data that immediately follows the picture header. The video decoder 209 is operable to detect and execute the commands. The execution of the commands effectuates the personal video recording functions. While the video decoder 209 decodes one GOP 123 , the controller 216 , and decryption engine 208 fetch, encrypt, create a table for, and writes commands for the next GOP 123 in the personal video recording function order. In the case of fast forward, the next GOP 123 is the next GOP 123 in the standard playback order. In the case of rewind, the next GOP 123 is the preceding GOP 123 .
[0029] Referring now to FIG. 3 , there is illustrated a block diagram describing encrypted GOPs 123 ( n −2), 123 ( n− 1), 123 ( n ), 123 ( n +1), 123 ( n +2), . . . stored in the buffer 203 . The encrypted GOPs 123 are generally stored in the buffer 203 in the order that the GOPs are received, and the encrypted GOPs are generally received in the order of standard playback.
[0030] Where during standard playback through picture 103 of GOP 123 ( n ), the circuit receives a request for the fast forward function, the controller 216 fetches the ending portion of GOP 123 ( n )′. The decryption engine 208 decrypts the remaining portion of the GOP 123 ( n )′ and writes the decrypted remaining portion of the GOP 123 ( n )′ to the compressed data buffer 218 . The controller 216 also receives and parses the remaining portion of the GOP 123 ( n )′, to create the picture table 230 . The video decoder 209 decodes at least some of the pictures in the ending portion 123 ( n )′ of the GOP. According to certain aspects of the present invention, the controller 216 can also write commands that effectuate the fast forward function.
[0031] While the video decoder 209 decodes at least some of the pictures in the ending portion of the GOP 123 ( n )′, the controller 216 fetches the GOP 123 ( n +1). The decryption engine 208 decrypts GOP 123 ( n +1) and writes the decrypted GOP 123 ( n +1) to the compressed data buffer 218 . The controller 216 receives and parses the GOP 123 ( n +1), to create the picture table 230 for GOP 123 ( n +1). The foregoing can be repeated for any number of GOPs.
[0032] The controller 216 can fetch the ending portion of the GOP 123 ( n )′, and next GOPs 123 ( n +1), 123 ( n +2), . . . , by using a pointer ptr. The controller 216 fetches the remaining portion 123 ( n )′ by using the pointer ptr to fetch data words. After fetching each data word, the pointer ptr is incremented. In the foregoing manner, the controller 216 can fetch the data words for the remainder of GOP 123 ( n )′, followed by GOP 123 ( n +1).
[0033] Where during standard playback through picture 103 of GOP 123 ( n ), the circuit receives a request for the rewind function, the controller 216 fetches the beginning portion of GOP 123 ( n )′. The decryption engine 208 decrypts the beginning portion of the GOP 123 ( n )″ and writes the decrypted beginning portion of the GOP 123 ( n )″ to the compressed data buffer 218 . The controller 216 also receives and parses the beginning portion of the GOP 123 ( n )′, to create the picture table 230 .
[0034] The video decoder 209 decodes at least some of the pictures in the beginning portion 123 ( n )″ of the GOP. According to certain aspects of the present invention, the controller 216 can also write commands that effectuate the rewind function.
[0035] While the video decoder 209 decodes the at least some of the pictures in the beginning portion of the GOP 123 ( n )″, the controller 216 fetches the GOP 123 ( n −1). The decryption engine 208 decrypts GOP 123 ( n −1) and writes the decrypted GOP 123 ( n −1) to the compressed data buffer 218 . The controller 216 receives and parses the GOP 123 ( n −1), to create the picture table 230 for GOP 123 ( n −1). The foregoing can be repeated for any number of GOPs.
[0036] The controller 216 can fetch the beginning portion of the GOP 123 ( n )″, and GOPs 123 ( n −1), 123 ( n −2), . . . , by using a pointer ptr. The controller 216 decrements the pointer ptr by a predetermined offset. The offset can be chosen to be large enough that the pointer ptr will point to an address that is at least before the starting address of the GOP. After decrementing the pointer ptr, the data words from the address pointed to by the pointer ptr are fetched and decrypted by the decryption engine 208 . The controller 216 examines the decrypted video data. When the controller 216 detects the start of a GOP, the data words are written to the compressed data buffer 218 .
[0037] Referring now to FIG. 4 , there is illustrated a flow diagram for the fast forward function, in accordance with an embodiment of the present invention. At 405 , the controller 216 receives a fast forward command. At 410 , the ending portion of the GOP(n)′ is fetched. At 415 , the ending portion of the GOP(n)′ is decrypted. At 420 , the controller 216 creates a picture table 230 for the remaining portion of the GOP(n)′. At 425 , the controller 216 writes commands to the pictures 103 of the GOP(n)′ that effectuate the fast forward command.
[0038] At 430 , the next GOP in the forward direction, e.g., GOP 123 ( n +1) is fetched. At 435 , the GOP is decrypted and stored, while the previous GOP is decoded according to the commands written in the pictures. At 440 , the controller 216 creates a picture table 230 for the GOP, while the previous GOP is decoded. At 445 , the controller 216 writes commands to the pictures 103 of the GOP that effectuate the fast forward command, while the previous GOP is decoded. The foregoing, 430 - 445 , can be repeated any number of times for any number of GOPs.
[0039] Referring now to FIG. 5 , there is illustrated a flow diagram for the rewind function in accordance with an embodiment of the present invention. At 505 , the controller 216 receives a rewind command. At 510 , the pointer ptr is decremented by an offset. At 515 , the video data starting from the new pointer address until the end of the beginning portion is decrypted. At 517 , the controller waits until the start of the GOP(n) is found. When the start of GOP(n) is found at 520 , the controller 216 creates a picture table 230 for the beginning portion of GOP 123 ( n )′. At 525 , the controller 216 writes commands to the pictures 103 of the that effectuate the rewind command.
[0040] At 530 , the pointer ptr is decremented by the offset. At 532 , the video data starting at the new pointer address is decrypted. At 534 , the controller 216 waits until the start of the next previous GOP(n−1). At 535 , the GOP is decrypted. At 540 , the controller 216 creates a picture table 230 for the GOP. At 545 , the controller 216 writes commands to the pictures 103 of the GOP that effectuate the fast forward command. The foregoing, 530 - 545 , can be repeated any number of times for any number of GOPs. During 530 - 545 , the video decoder 209 decodes at least some of the pictures in the next GOP, e.g., GOP 123 ( n ).
[0041] Referring now to FIG. 6 , there is illustrated a block diagram of a picture 103 storing commands for execution by the video decoder 209 . The picture 103 comprises a picture header 103 ( a ). The picture header 103 ( a ) is followed by a field known as user data, ud.
[0042] The controller 216 writes commands CMD effectuating the fast forward or rewind function by first writing a user data start code, USER DATA START CODE, asignature, SIGNATURE, followed by commands, CMD . . . CMD to the user data, ud. The signature, SIGNATURE, can comprise, for example, 0x42 52 43 4D.
[0043] In the case where the picture 103 includes user data prior to insertion of the commands CMD by the controller 216 , the controller 216 writes the user data start code, USER DATA START CODE, signature SIGNATURE, and commands CMD, prior to the original user data start code USER DATA START CODE’, and the user data DATA.
[0044] The particular sequence of commands can comprise, for example, the sequences of commands described in “Command Packet System and Method Supporting Improved Trick Mode Performance in Video Decoding Systems”, application Ser. No. 10/317,389, filed Dec. 11, 2002, by Aggarwal, et. al., which is incorporated herein by reference for all purposes.
[0045] The foregoing does not depend on commands inserted in a transport packet. A host application can send commands to the video decoder even when the application is not using the transport layer, such as the packetized elementary stream layer or elementary stream layer. This is because the commands are carried through the user data. The user data is carried within the stream and does not need transport headers or packets. Thus, the foregoing can be used with systems that do not use transport streams for transmitting data.
[0046] The embodiments described herein may be implemented as a board level product, as a single chip, application specific integrated circuit (ASIC), or with varying levels of the decoder system integrated with other portions of the system as separate components. The degree of integration of the decoder system will primarily be determined by the speed and cost considerations. Because of the sophisticated nature of modern processor, it is possible to utilize a commercially available processor, which may be implemented external to an ASIC implementation. Alternatively, if the processor is available as an ASIC core or logic block, then the commercially available processor can be implemented as part of an ASIC device wherein certain functions can be implemented in firmware. In one embodiment, the present invention can comprise an integrated circuit.
[0047] While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention.
[0048] In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims. | Described herein are system(s), method(s), and apparatus for embedding personal video recorder functions at the picture level. In one embodiment, there is presented a computer readable medium for storing a data structure. The data structure comprises a picture header and at least one command following the picture header. | 6 |
STATEMENT OF RELATED CASES
This case claims priority of U.S. Provisional Patent Application 60/992,025 filed Dec. 3, 2007, which is incorporated herein by reference.
Field of the Invention
The present invention relates to supercavitating projectiles.
BACKGROUND OF THE INVENTION
Cavitation is a general term used to describe the behavior of voids or bubbles in a liquid. Cavitation occurs when water pressure is lowered below its vapor pressure or vapor pressure is increased to water pressure. When this happens, the water vaporizes, typically forming small bubbles of water vapor. But these bubbles of water vapor are typically not sustainable. Rather, the bubbles collapse, and when they do, they force liquid energy to very small volumes. This results in localized high temperature and the generation of shock waves.
Cavitation is ordinarily an unintended and often undesirable phenomenon. The collapse of small bubbles produces great wear on pump components and can dramatically shorten the useful life of a propeller or pump. It also causes a great deal of noise, vibration, and a loss of efficiency.
But the phenomenon of cavitation is not always undesirable; an exception is the phenomenon of “supercavitation.” In supercavitation, a sustainable bubble of gas inside a liquid is created by a “nose cavitator” of a moving object. This bubble envelopes the entire moving object except for the nose, with the result that the drag experienced by the moving object is significantly reduced. As a consequence, a supercavitating object can travel at far greater speeds for a given amount of thrust than an object that is moving in a conventional manner through water. Supercavitation enhances motion stability of an object as well.
A supercavitating (hereinafter also “cavity-running”) object's main features are a specially shaped nose and a streamlined, hydrodynamic, and aerodynamic body. When the object is traveling through water at speeds in excess of about one hundred miles per hour, the specially-shaped nose deflects the water outward so fast that the water flow separates and detaches from the surface of the moving object. Since water pressure takes time to collapse the wall of the resulting cavity, the nose opens an extended bubble or cavity of water vapor. Given sufficient speed, the cavity can extend to envelop the entire body of the object. A cavity-running object quite literally ‘flies’ through the surrounding gas. In the absence of sustaining propulsion, the moving object loses supercavitation and eventually stalls due to drag.
SUMMARY OF THE INVENTION
The present invention provides improved designs for cavity-running projectiles and improved methods for their operation.
The present inventor has identified a variety of important operational considerations pertaining to cavity-running projectiles. These include, without limitation:
An operational mode for expending the minimal thrust required to sustain supercavitation (hereinafter “threshold thrust”). Optimization of projectile structural design as a function of parameters such as operating depth and available thrust. Defining operational limits for a cavity-running projectile as a function of available thrust and certain structural considerations of the projectile. Operating to achieve certain mission requirements, such as minimizing a projectile's time-of-arrival (or time-to-impact). Defining the best way accelerate a projectile from rest to supercavitation.
It is advantageous to reduce, to the extent possible, the amount of thrust that is required to sustain a projectile in a cavity-running mode of operation through water. The present inventor recognized that the threshold thrust would likely be related to certain structural aspects of the projectile, among any other parameters.
In fact, the present inventor found that there is a relationship between the threshold thrust and the ratio of the diameter D B of the body of the projectile to the diameter D N of the nose of the projectile. That is, to the extent that certain other parameters are fixed, there an “optimal” ratio of the aforementioned diameters, in the sense that it minimizes the threshold thrust. That optimal value of the ratio D B :D N is about 4.1.
Using the same line of reasoning and related mathematical expressions, the present inventor also developed an expression for determining the maximum allowable projectile depth under water for sustaining a cavity-running mode for a given amount of thrust. And the present inventor also developed an expression for determining an “optimal” diameter of the projectile's nose given a certain amount of thrust and an operating depth. Optimal in a sense that, at the calculated the diameter, the thrust is the threshold thrust. These expressions can be employed to provide various operating scenarios for the projectile.
The present inventor further recognized that the most efficient way (in terms of minimizing thrust requirements) to operate a supercavitating projectile is to:
launch it at some velocity above a minimum that is required to maintain supercavitating movement of the projectile; permit the velocity of the projectile to decrease to a value just above that required to sustain supercavitating movement; and initiate thrust to maintain supercavitating movement, wherein just enough thrust is applied to maintain supercavitating movement (i.e., the threshold thrust).
The present inventor also theorized that there might be a way to operate a supercavitating projectile that minimizes the projectile's time-to-impact at a target. In particular, consider a projectile that is launched from a ship into the water and is to attain a cavity running mode. Due to the high initial velocity of the projectile, the drag it experiences is relatively large. The drag abates as the projectile slows. If additional thrust (to maintain cavity running operation) is initiated too early, the projectile loses the benefit of some additional drag attenuation. If, on the other hand, additional thrust is delayed for too long, the projectile might lose supercavitation or suffer stability and control issues.
In fact, the present inventor determined that by appropriately delaying the time when thrust is initiated, the time-to-impact can indeed be minimized. The delay is given by the expression:
t 1 =[1/( KV c )]×[tan −1 ( V 0 /V C )−tan −1 ( cV sc /V c )], [1]
wherein:
K=(Π/8 m)×ρ water D N 2 C d0 ; m is the mass of the projectile; ρ water is the density of the water at the relevant temperature; D N is the diameter of the projectile's nose; C d0 is the drag coefficient under supercavitation; c is a parameter used for specifying thrust; V c is the characteristic velocity: V c =(2P/ρ water ); P is the static drag V 0 is initial velocity.
The present inventor also recognized that an issue exists as to the manner in which a projectile is accelerated from rest to supercavitation. In fact, the inventor determined that the most efficient method of operation for a projectile accelerating from rest to supercavitation is to apply maximum thrust for a period of time and then reduce the thrust to the threshold thrust (i.e., the amount of thrust required to maintain supercavitation). The time to switch from maximum thrust to threshold thrust is given by the expression:
t *=(½ K b )×ln [(1+(2−ε) 0.5 )/(1−ε 0.5 )], [2]
wherein:
K b =(Π/8 m)×ρ water D B 2 C d0 ; m is the mass of the projectile; ρ water is the density of the water at the relevant temperature; D B is the diameter of the projectile's body; C d0 is the drag coefficient under supercavitation; ε=E/E s,max E=E c ≡½V 2 E s,max =(B max /2K b )−E c V is projectile velocity; and B max is the maximum available thrust.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a projectile being fired into the water from the deck of ship, wherein the projectile enters a cavity-running mode under water, as described in co-pending patent applications by applicant.
FIG. 2 depicts a supercavitating projectile, as described in co-pending patent applications by applicant.
FIG. 3 depicts the air cavity in which a supercavitating projectile moves, as in known in the prior art.
FIG. 4 depicts two basic operational modes for a supercavitating projectile.
FIG. 5 depicts, graphically, a method for operating a supercavitating projectile in accordance with the illustrative embodiment of the present invention.
FIG. 6 depicts a flow diagram of the method depicted in FIG. 5 .
FIG. 7 depicts, graphically, a method for operating a supercavitating projectile in accordance with an alternative embodiment of the present invention.
FIG. 8 depicts a flow diagram of the method depicted in FIG. 7 .
DETAILED DESCRIPTION
FIG. 1 depicts a known weapons system comprising a deck-launched anti-torpedo projectile 106 . The system includes both LIDAR and SONAR (not depicted) for target acquisition and an integrated weapons control system 104 . Projectile 106 is launched from ship 102 and follows trajectory 108 into water 110 at a shallow grazing angle to intercept torpedo 100 .
Projectile 106 must be capable of (1) flying through the air, (2) maintaining integrity as it penetrates the surface of the water, (3) maintaining trajectory (avoid pitch down, skipping, etc.) as it enters the water, and (4) moving through water in a cavity-running mode. Such a projectile should possess the following characteristics:
is fin or spin stabilized (for requirement 1); is constructed of suitably strong materials of appropriate diameter (for requirement 2); a stepped profile characterized by a plurality of substantially right-circular cylindrical sections of increasing diameter or a stepped profile defined by a plurality of substantially right-circular conic sections of increasing diameter (for requirement 3); a forward center of gravity (for requirements 3 and 4); a blunt nose (for requirements 3 and 4); suitable dimensions (e.g., ratio of nose diameter to body diameter, etc.) (for requirement 4); and tail fins with a relatively smaller span and a relatively longer chord (for requirement 4).
A projectile suitable for this service has been described in applicant's co-pending patent application Ser. No. 12/057,123, which is incorporated by reference herein.
FIG. 2 depicts an embodiment of projectile 106 . The projectile comprises nose 220 and body 226 . Nose 220 is characterized by a plurality of substantially right-circular cylindrical sections 222 . Tip 224 of nose 220 is flat, as is required to create the cavitation phenomena. As depicted in FIG. 3 , the gradual increase in diameter of cylindrical sections 222 defines a geometry that remains completely within the bounds of vapor cavity 330 that forms due to the supercavitation phenomena. It also prevents the projectile from pitching down (i.e., overturning) during water entry. The aft section of body 226 includes a plurality of fins 228 , as shown in FIG. 2 .
As previously indicated, the center of gravity of projectile 106 should be situated as far forward as possible to prevent the in-water projectile from overturning. This is addressed, in some embodiments, via two different materials of construction. In particular, a relatively more dense material is used for the nose, etc., and a relatively less dense material is used for the body. For example, in some embodiments, the nose comprises tungsten and the body comprises bronze. In some other embodiments, the nose is tungsten and the body comprises aluminum. In yet some further embodiments, the nose comprises tungsten and the body comprises titanium. In some additional embodiments, the nose and body comprise S-7 steel. In some embodiments, the projectile comprises a back that is at least partially “hollowed out.” The removal of material from the aft section of the projectile serves to keep its center of gravity forward.
It has been shown through experimentation that projectiles having lengths within the range of approximately 4 inches to approximately 9 inches and diameters within the range of approximately 0.5 inch to approximately 2 inches have beneficial performance characteristics. It should be noted, however, that these dimensions are merely representative and are not intended to limit the present invention.
There are two basic modes of operation for a cavity-running projectile. One is to launch a projectile at a speed that is well in excess of velocity V sc required to sustain supercavitation. The aforementioned system in which projectile 106 is launched from the deck of a ship through air and then into the water is an example of this mode of operation. This mode is illustrated in the upper portion of the plot depicted in FIG. 4 (entitled “Decelerating From Speed”). The plot depicts a decrease in the velocity of the projectile toward velocity V sc .
A second mode of operation is to launch a powered projectile underwater. In this mode, the velocity of the projectile increases to velocity V sc . This mode is illustrated in the lower portion of the plot depicted in FIG. 4 (entitled “Accelerating From Rest”).
Regardless of operating mode, it is advantageous to reduce the amount of thrust that is required to sustain a projectile in a cavity-running mode of operation through water. In fact, the present inventor found that there is a relationship between the threshold thrust and the ratio of the diameter D B of the body of the projectile to the diameter D N of the nose of the projectile. That is, to the extent that certain other parameters are fixed, there an “optimal” ratio of the aforementioned diameters, in the sense that it minimizes the threshold thrust. That optimal value of the ratio is:
D B :D N ˜4.1 [3]
From the same derivation, minimal supercavitating velocity V sc * is given by:
V sc *=4.265 V c [4]
wherein:
V c is the characteristic velocity: V c =(2P/ρ water ); and P is the static drag.
From the same derivation, the minimal amount of thrust F* to maintain supercavitating operation is given by:
F *=(π/4)12 D N 2 C do P (1+(δ 1 /δ 0 ) 2 ]( [5]
wherein:
D N is the diameter of the projectile's nose; C d0 is the drag coefficient under supercavitation (˜0.2); P is the static drag on the projectile; δ 0 =0.213387 (empirically determined); and δ 1 =0.910052 (empirically determined).
Expression [5] is approximately equal to:
F*˜12D N 2 P [6]
The present inventor also developed an expression for determining the maximum allowable depth H* in water for the projectile, while sustaining a cavity-running mode, based on the available thrust. The depth H* is given by:
H *=(( F max /[(π/4)12 D N 2 C do (1+(δ 1 /δ 0 ) 2 ])− ATM )/(ρ water g ) [7]
wherein:
F max is maximum available thrust; D N is the diameter of the projectile's nose; C d0 is the drag coefficient under supercavitation (˜0.2); δ 0 =0.213387 (empirically determined); δ 1 =0.910052 (empirically determined); ATM is the water pressure bearing on the projectile; ρ water is the density of the water at the relevant temperature; and g is the acceleration due to gravity.
Expression [7] is approximately equal to:
H*˜(F max /(12D N 2 )−ATM)/(ρ water g). [8]
The present inventor also developed an expression for determining an “optimal” diameter D N * of the projectile's nose given available thrust F and operating depth H. Optimal in a sense that, at the calculated nose diameter, the thrust is the threshold thrust.
D N *=(( F max /(ρ water gH+ATM ))/[(π/4) D N 2 C do (1+(δ 1 /δ 0 ) 2 ]) 0.5 [9]
wherein:
F max is maximum available thrust; D N is the diameter of the projectile's nose; C d0 is the drag coefficient under supercavitation (˜0.8); δ 0 =0.213387 (empirically determined); δ 1 =0.910052 (empirically determined); ATM is the water pressure bearing on the projectile; ρ water is the density of the water at the relevant temperature; and g is the acceleration due to gravity.
Expression (9) is approximately equal to:
H*= 1/(12) 0.5 ( F max /(ρ water gH+ATM )) 0.5 [10]
As discussed later in this specification, expressions [3], [4], [5]/[6], [7]/[8], and [9]/[10] can be used as the basis for various operating scenarios for the projectile.
For either of the two basic operating modalities disclosed above, an issue arises as to the most efficient way to implement method to achieve a specific goal. One example is what approach should be taken to minimize the time-to-target for a cavity-running projectile that is launched at high speed. A second example is what approach should be taken to minimize the amount of thrust required to travel a certain distance in a cavity-running mode.
FIGS. 5 and 6 depict a method for reducing arrival time at R of a supercavitation projectile by delaying thrust.
The present inventor recognized that when projectile 106 is launched, for example, from a deck-mounted launcher, it's velocity will be well in excess of the 100 mph or so that is required for sustaining supercavitation. As the projectile initially enters the water, it experiences high drag forces. These high drag forces persist until a vapor cavity fully develops around the projectile. Within the cavity, drag forces are much lower, but a relatively higher velocity results in a relatively higher drag on the projectile. As velocity rapidly decreases, drag forces decline, unless and until supercavitation is lost.
Given a powered projectile, the inventor recognized that in view of the foregoing considerations, the minimum time to target might not result from operating the projectile at maximum thrust. It turns out, in fact, that the best strategy for reducing time-to-target (or time of arrival) for a supercavitating projectile is actually to delay thrust. In particular, given a powered projectile that is launched at a speed well in excess of that required for supercavitation, the best strategy is launch, delay thrusting until the projectile is about to lose supercavitation, and then apply thrust slightly about the threshold amount that is required to maintain supercavitation.
As depicted in FIGS. 5 and 6 , the projectile is launched at an initial velocity V 0 that is well in excess of that required for supercavitation (operation 602 ), and the projectile is allowed to “glide” until the projectile's velocity drops to value cV sc that is close to the minimum velocity V sc required to maintain supercavitation (operation 604 ). That occurs at time t 1 after traveling distance R 1 . At that time, thrust is applied to maintain near-minimum supercavitation velocity cV sc (operation 606 ) for the distance R−R 1 .
The inventor analytically derived formulae for the velocity and distance traveled by a cavity-running projectile with and without propulsion. Travel from time 0 to time t 1 is without thrust; t 1 is the time delay. The time t 2 =(T−t 1 ) for traveling the remaining distance R−R 1 is derived. The projectile is propelled against drag due that is experienced in the cavity at velocity cV sc for the time period t 2 . The final expressions are obtained via calculus by obtaining and equating the first derivative of t 1 +t 2 with respect to time t 1 .
The times t 1 (previously supplied as expression [1]) and t 2 are given by:
t 1 =[1/( KV c )]×[tan −1 ( V 0 /V C )−tan − ( cV sc /V c )] [1]
t 2 =[R −(½ K )×ln [( V 2 0 /V 2 C )/( c 2 V 2 sc +V 2 c )]/( cV sc ) [11]
wherein:
K=(Π/8 m)×ρ water D N 2 C d0 ; m is the mass of the projectile; ρ water is the density of the water at the relevant temperature; D N is the diameter of the projectile's nose; C d0 is the drag coefficient under supercavitation; c is a parameter used for specifying thrust (c≧1 at high thrust [e.g., c=1.1], c<1 at low thrust); V c is the characteristic velocity: V c =(2P/ρ water ); and P is the static drag.
Total time to impact(or arrival)T is t 1 +t 2 [12]
And the distance traveled at t 1 is given by:
R 1 =(½ K )×ln [( V 2 0 /V 2 C )/( V 2 1 +V 2 c )] [13]
Wherein V 1 =cV sc =V c ×tan [tan −1 ( V 0 /V c )− KV c t 1 ] [14]
FIGS. 7 and 8 depict an efficient method for accelerating from rest (zero velocity) to supercavitation.
As depicted in FIGS. 7 and 8 , the projectile is accelerated from rest at the maximum available thrust (operation 802 ). The projectile is accelerated to supercavitation at velocity V sc , which occurs at time t* (operation 804 ). Once in a cavity-running mode, thrust is reduced to the threshold thrust, which is the minimum amount of thrust that is required to maintain supercavitation (operation 806 ).
The inventor analogized the problem to a “charge-up” application of the switching techniques disclosed in U.S. Pat. No. 6,611,119 and co-pending patent application Ser. No. 12/119,991.
The time to switch from maximum thrust to threshold thrust (previously presented as expression [2] is given by the expression:
t *=(½ K b )×ln [(1+(2−ε) 0.5 )/(1−ε 0.5 )], [2]
wherein:
K b =(Π/8 m)×ρ water D B 2 C d0 ; m is the mass of the projectile; ρ water is the density of the water at the relevant temperature; D B is the diameter of the projectile's body; C d0 is the drag coefficient under supercavitation; ε=E/E s,max E=E c ≡½ V 2 E s,max =(B max /2K b )−E c V is projectile velocity; and B max is the maximum available thrust.
It is to be understood that the disclosure teaches just one example of the illustrative embodiment and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure and that the scope of the present invention is to be determined by the following claims. | A method for operating a thrust-generating supercavitating projectile involves launching the projectile at a velocity above the minimum required to maintain supercavitating movement, delaying initiation of thrust until the projectile slows to a velocity that is near that minimum velocity, and then applying thrust to maintain the near-minimum velocity until a target is reached. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a method and an apparatus for operating a tool in a wellbore. More particularly, the invention relates to positioning a tool in a wellbore and setting the tool in a fixed position. Still more particularly, the invention relates to actuation of a downhole hydraulic tool by an actuation apparatus that uses a pressure differential in a conduit carrying a fluid flow to actuate the downhole hydraulic tool.
2. Description of the Related Art
Hydraulically-actuated tools such as packers and anchor assemblies have long been used in the drilling industry. A tool often used in conjunction with anchors or packers is a deflector, which is commonly called a whipstock. A deflector includes an inclined face and is typically used to direct a drill bit or cutter in a direction that deviates from the existing wellbore. The combination deflector and anchor (or packer) is frequently termed a sidetrack system. Sidetrack systems have traditionally been used to mill a window in the well casing, and thereafter to drill through the casing window and form the lateral wellbore.
Originally, such a sidetrack operation required two trips of the drill string. The first trip was used to run and set the anchor or packing device at the appropriate elevation in the wellbore. With the anchor or packer in place, the drill string was then removed from the well and a survey was made to determine the orientation of a key on the upper end of the anchor-packer. With that orientation known, the deflector was then configured on the surface so that when the deflector engaged the anchor-packer in the wellbore, it would be properly oriented. So configured, the deflector, along with an attached cutter, was then lowered in the wellbore on the drill string and secured to the anchor-packer. Once connected to and supported by the packer, the deflector directed the cutter so that a window would be milled in the casing of the wellbore at the desired elevation and in the preselected orientation. This two-trip operation for setting the anchor-packer and then lowering the deflector and cutter is time-consuming and expensive, particularly in very deep wells.
To eliminate the expense associated with two trips of the drill string, an improved sidetrack system was developed which required only a single trip. Such a system includes a deflector having an anchor-packer connected at its lower end, and a cutter assembly at its upper end connected by a shearable connection. Using such a system, the deflector is oriented by first lowering the apparatus into the cased wellbore on a drill string. A wireline survey instrument is then run through the drill string to check for the proper orientation of the suspended deflector. After the deflector is properly oriented in the wellbore, and the anchor-packer set, the drill string is then lowered causing the cutter assembly to become disconnected from the deflector. As the cutter is lowered further, the inclined surface of the deflector urges the rotating cutter against the well casing, causing the cutter to mill a window in the casing at the predetermined orientation and elevation.
To be contrasted with wireline devices, there exist today a variety of systems that are capable of collecting and transmitting data from a position near the drill bit while drilling is in progress. Such measuring-while-drilling (“MWD”) systems are typically housed in a drill collar at the lower end of the drill string. In addition to being used to detect formation data, such as resistivity, porosity, and gamma radiation, all of which are useful to the driller in determining the type of formation that surrounds the wellbore, MWD tools are also useful in surveying applications, such as, in determining the direction and inclination of the drill bit. Present MWD systems typically employ sensors or transducers which, while drilling is in progress, continuously or intermittently gather the desired drilling parameters and formation data and transmit the information to surface detectors by some form of telemetry, most typically a mud pulse system. The mud pulse system creates acoustic signals in the drilling mud that is circulated through the drill string during drilling operations. The information acquired by the MWD sensors is transmitted by suitably timing the formation of pressure pulses in the mud stream. The pressure pulses are received at the surface by pressure transducers that convert the acoustic signals to electrical pulses, which are then decoded by a computer.
MWD tools presently exist that can detect the orientation of the drill string without the difficulties and drawbacks described above that are inherent with the use of wireline sensors. However, known MWD tools typically require drilling fluid flow rates of approximately 250 gallons per minute to start the tool, and 350 to 400 gallons per minute to gather the necessary data and transmit it to the surface via the mud pulse telemetry system. The conventional bypass valves used in present-day sidetrack systems for circulating drilling fluid and transporting a wireline sensor to the deflector tend to close, and thereby actuate the anchor-packer, at flow rates of approximately 100 gallons per minute, or even less. Thus, while it might be desirable to combine MWD sensors in a sidetrack system, if drilling mud was circulated through the drill string at the rate necessary for the MWD tool to detect and communicate to the driller the orientation of the deflector, the bypass valve would close and the anchor-packer would be set prematurely, before the deflector was properly oriented. As described in the following paragraphs, there are several different methods for setting a downhole tool such as an anchor-packer.
An improved apparatus for setting a hydraulically actuated downhole tool in a wellbore is disclosed in Bailey, U.S. Pat. No. 5,443,129, which is incorporated herein by reference in its entirety. The '129 apparatus utilizes a bypass valve located in the run-in string below the MWD device and above the cutter. The valve is in an open position while the MWD device is operating thereby diverting fluid flow and pressure from the tubular to the annulus without creating a pressure sufficient to actuate a downhole tool. Upon completion of operation of the MWD device, the bypass valve is remotely closed. Thereafter, selectively operable ports in the cutter are opened and the tubular therebelow is pressurized to a point necessary to actuate the tool. While the apparatus of the '129 patent allows operation of a MWD device without the inadvertent actuation of a downhole tool, the bypass valve is complex requiring many moving parts and prevents the continuous flow of fluid through the cutter. Additionally, the bypass valve may not function properly in a wellbore that contains little or no fluid. Finally, the fluid borne sediment tends to settle and collect in the cutter.
An apparatus to actuate a downhole tool is disclosed in Brunnert, U.S. Pat. No. 6,364,037, which is incorporated herein by reference in its entirety. The '037 invention provides an apparatus for actuating a downhole tool by utilizing a pressure differential created by fluid flowing through a conduit. The conduit is in communication with a pressure sensing line that is selectively exposed to areas of the conduit having different pressures. By exposing the pressure sensing line to a portion of the conduit having a predetermined pressure therein, the pressure sensing line causes actuation of a hydraulic tool therebelow. While the apparatus of the '037 patent allows operation of a MWD device without the inadvertent actuation of a downhole tool, the apparatus is complex requiring many moving parts.
A whipstock setting apparatus is disclosed in Braddick, U.S. Pat. No. 5,193,620, which is incorporated herein by reference in its entirety. The '620 invention provides a whipstock setting apparatus that includes a whipstock and a mandrel. A downhole tool including a mechanical weight set packer and upper and lower cone and slip means are mounted on the mandrel above and below the downhole tool. The mandrel is releasably connected to the downhole tool to prevent premature longitudinal movement while accommodating the relative longitudinal movement at a predetermined point. The components of the whipstock assembly and downhole tool are secured to maintain alignment with the face of the whipstock while lowering the whipstock in the well tubular member. Thereafter, the mandrel is released and the whipstock is oriented in the well tubular member. Subsequently, the oriented whipstock and downhole tool are mechanically anchored in the well tubular member by longitudinal movement of the work string. While the apparatus of the '620 patent actuates the downhole tool without any complex hydraulic mechanism, the manipulation of the piping string to initiate the sequence of events to set the whip stock setting apparatus may not be effective in a deviated wellbore due to the angle of the wellbore and frictional problems.
A one-trip whipstock milling system is disclosed in Ross, U.S. Pat. No. 5,947,201, which is incorporated herein by reference in its entirety. The '201 invention provides a bottomhole assembly that includes a whipstock milling system, a downhole tool, a whipstock and orientation instrumentation. After the bottomhole assembly is located in the wellbore, the wellbore is pressurized to actuate the downhole tool. Thereafter, the milling operation cuts a window in the surrounding casing. While the apparatus of the '201 patent actuates the downhole tool without a complex hydraulic mechanism or mechanical manipulation of the piping string, the pressurizing of the wellbore is very costly and will not operate properly if there is little or no fluid in the wellbore.
There is a need therefore, for a single trip sidetrack apparatus permitting a continuous flow of well fluid therethrough while allowing the actuation of a hydraulically actuated tool at a predetermined position in the borehole. There is a further need therefore, for a single trip sidetrack apparatus that does not depend on a value to prevent inadvertent actuation of a downhole tool. There is a further need for an actuation apparatus that allows fluid to flow therethrough before and during actuation of a downhole tool. There is yet a further need for actuating a hydraulically actuated tool in a wellbore that contains little or no wellbore fluid. Finally, there is a need for a single trip sidetrack apparatus that contains an actuation apparatus with no moving parts.
SUMMARY OF THE INVENTION
The present invention generally relates to an apparatus and method for operating a tool in a wellbore. In one aspect, the apparatus includes a hydraulically operated tool and a wellbore tubular both in communication with a pressure sensing line. The hydraulically operated tool is responsive to a combination of fluid pressure in the pressure sensing line and manipulation of the wellbore tubular, such response causing the tool to operate within the wellbore.
In another aspect, the wellbore tubular includes a mechanism to create a differential pressure, whereby a higher pressure is created in an upper region above the mechanism and a low pressure is created in a lower region below the mechanism. The mechanism comprises a restriction formed in the wellbore tubular and a seat for a hydraulic isolation device.
In another aspect, the invention provides a method for anchoring a well tool in a wellbore. The method includes the steps of lowering the well tool into the wellbore on a tubular string, flowing fluid through the tubular string to begin anchoring the well tool, and manipulating the tubular string to complete the anchoring of the well tool.
In yet another aspect, the invention provides a method of anchoring a tool in a wellbore that includes the step of lowering the tool on a wellbore tubular into the wellbore, the wellbore having a first portion substantially devoid of liquid. The method further includes the steps of locating the tool in the first portion and flowing fluid through the wellbore tubular to anchor the tool in the first portion.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of 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 an elevation view of a side track system disposed in a wellbore.
FIG. 2 is a cross-sectional view illustrating one embodiment of an actuation apparatus for use in the sidetrack system.
FIG. 3 is a cross-sectional view illustrating a downhole tool in a run-in position.
FIG. 4 is a cross-sectional view illustrating the slips expanded radially outward into a surrounding casing to secure the downhole tool in the wellbore.
FIG. 5 illustrates a packing element expanded into the surrounding casing to seal off a portion of the wellbore.
FIG. 6 illustrates the deactivation of the downhole tool.
FIG. 7 illustrates an alternative embodiment of a downhole tool in a run-in position.
FIG. 8 is an enlarged view illustrating a large piston area prior to setting the slips.
FIG. 9 illustrates the downhole tool after the packing element and slips are set in the surrounding casing.
FIG. 10 is an enlarged view illustrating a small piston area after the slips are set.
FIG. 11 is a cross-sectional view illustrating an alternative embodiment of an actuation apparatus in the run-in position.
FIG. 12 is a cross-sectional view illustrating the flow rate through the actuation apparatus to operate a MWD device.
FIG. 13 is a cross-sectional view illustrating the flow rate through the actuation apparatus to actuate the downhole tool.
FIG. 14 is a cross-sectional view illustrating the flow rate through the actuation apparatus after the downhole tool is actuated.
FIG. 15 is a cross-sectional view illustrating an alternative embodiment of an actuation apparatus.
FIG. 16 is a cross-sectional view illustrating an alternative embodiment of an actuation apparatus.
FIG. 17 is a cross-sectional view illustrating an alternative embodiment of an actuation apparatus with a hydraulic isolation device.
FIG. 18 is a cross-sectional view illustrating the removal of the hydraulic isolation device from the actuation apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention provides a sidetrack system 10 useful for offsetting a wellbore by directing a drill bit or cutter at an angle from the existing wellbore. FIG. 1 is an elevation view of the sidetrack system 10 disposed in a wellbore 60 . The sidetrack system 10 is shown attached at the lower end of a tubular string 20 and run into the wellbore 60 lined with casing 30 . However, the invention is not limited to use in a cased wellbore, but is equally applicable to open, non-cased wellbores. Thus, throughout this disclosure, the term “wellbore” shall refer both to cased wellbore and open wellbore.
The sidetrack system 10 generally includes a MWD device 25 , an upper actuation apparatus 100 , a window mill 125 , a deflector 50 , and a hydraulically operated downhole tool 200 . The MWD device 25 provides the driller with intelligible information at the surface of wellbore 60 that is representative of the orientation of the sidetrack system 10 , and provides a variety of other downhole measurements and data. Typically, the MWD 25 includes a conventional mud pulse telemetry system. The mud pulse telemetry system is well understood by those skilled in the art, thus only a brief description of the system is provided herein. Mud pumps located at the surface of the well circulate drilling mud into the top of the drill string. The mud is conducted through the drill string into the MWD 25 where it passes through a mud pulser that repeatedly interrupts the mud flow to produce a stream of pressure pulses in the circulating drilling mud that can be detected at the surface by pressure transducers. These signals are then analyzed by computer on a continuous basis to determine the inclination, azimuth and other pertinent information that is displayed to an operator by means of a monitor and recorded by a recorder.
The operation of the MWD 25 can be performed without actuating the downhole tool 200 because a greater amount of flow is required to actuate the tool 200 than is required to operate the MWD 25 . After operation of the actuation apparatus 100 , the downhole tool 200 can be actuated prior to separation of the window mill 125 from the deflector 50 . Generally, the deflector 50 or whipstock comprises an elongated tubular member having an inclined face 55 that, once properly oriented in the wellbore 60 , is used to deflect the window mill 125 into the casing 30 . The deflector 50 is fixed to a bent sub 205 on the downhole tool 200 . The bent sub 205 is slightly bent at an angle to ensure the deflector 50 remains flush against the casing 30 , thereby allowing the inclined face 55 of the deflector 50 to be oriented to the low side of the casing 30 . In addition, the interior of deflector 50 includes a pressure sensing line (not shown) for transmitting pressure from the actuation apparatus 100 to the downhole tool 200 as will be described fully herein. Additionally, the bent sub 205 functions as a point of disconnect between the deflector 50 and the tool 200 in the event the tool 200 becomes immobilized downhole.
In the embodiment illustrated, the downhole tool 200 includes two subassemblies a packer and an anchor. Generally, the packer is a mechanically actuated subassembly that, upon actuation, attaches to the wellbore casing 30 at a predetermined elevation to seal a portion of the wellbore 60 below the packer from a portion above it. While the anchor subassembly is a hydraulically actuated mechanism which, upon delivery of a pressurized fluid at a predetermined pressure becomes set in the casing 30 so as to support deflector 50 . The anchor subassembly generally includes a set of slips and cones that fix the sidetrack system 10 in the wellbore 60 as will be described fully herein.
In the preferred embodiment, the downhole tool 200 is actuated by sequential actions of the actuation apparatus 100 and mechanical force supplied by the drill string 20 . The components making up the actuation apparatus 100 are visible in FIG. 2 . The actuation apparatus 100 is installed in a tubular member 105 above window mill 125 . The window mill 125 includes a plurality of cutters 130 and flow ports 135 which provide an exit for fluids pumped through tubular member 105 from the well surface.
FIG. 2 is a cross-sectional view illustrating one embodiment of the actuation apparatus 100 for use with the sidetrack system 10 . As shown, a sand tube 110 is disposed in the tubular member 105 and secured in place by set screw 165 . The sand tube 110 acts as a sand screen to prevent sand from clogging up a pressure port 140 formed in the tubular member 105 . The sand tube 110 includes a slit 115 located in region 155 to communicate the change in pressure through an annular area 170 and subsequently into the pressure port 140 . The purpose of the annular area 170 is to create a tortuous path and a still space to allow communication of pressure while minimizing any particulate matter entering the port 140 . Additionally, the sand tube 110 includes restriction 120 in the inner diameter thereof, which serves to restrict the flow of fluid through tubular member 105 . As fluid passes through the actuation apparatus 100 and encounters restriction 120 , the pressure of the fluid drops in a region 160 directly below restriction 120 and increases in the region 155 directly above restriction 120 , thereby creating a pressure differential between the two regions 155 , 160 . Conversely, the velocity of the fluid decreases in area 155 and increases in area 160 . Formed in a wall of tubular member 105 is the pressure port 140 . Connected in fluid communication to pressure port 140 through a fitting 145 is a pressure sensing line 150 .
In order to actuate the tool (not shown), fluid at a predetermined flow rate is applied through the tubular member 105 . As fluid moves through restriction 120 , a higher pressure is created in region 155 . The higher pressure is communicated into the slit 115 in the sand tube 110 through the annular area 170 into the pressure port 140 and subsequently through the pressure sensing line 150 into the tool. The tool 200 as illustrated in FIG. 3 is constructed and arranged to hydraulically actuate a plurality of slips 275 based upon the pressure differential communicated through the pressure sensing line 150 . It should be noted that the pressure differential may be created by compressible fluid such as a foam or incompressible fluid such as drilling fluid.
FIG. 3 is a cross-sectional view illustrating the downhole tool 200 in a run-in position. In the preferred embodiment, the fluid pressure in the actuation apparatus 100 is communicated through the pressure sensing line 150 to the downhole tool 200 , thereby allowing the piston 245 to be hydrostatically balanced. Generally, the fluid pressure is communicated through the center of the tool 200 through a flow path consisting of a sub bore 210 , a stinger bore 310 , and a lower body bore 225 . Thereafter, the fluid pressure enters cavity 240 through body port 235 that is formed at the lower end of the lower body 230 . A force is created on a lower piston surface 246 as the fluid pressure builds in the cavity 240 . At the same time, an opposite force is created on the upper piston surface 248 by a hydrostatic pressure that is communicated from an annulus 70 through a housing port 260 into a housing cavity 255 . As the force on the lower piston surface 246 becomes greater than the force on the upper piston surface 248 , the pressure differential on the piston 245 begins the setting sequence of tool 200 . Typically, the annulus 70 in the wellbore 60 contains wellbore fluid, thereby allowing the fluid to be communicated through the housing port 260 to create a fluid pressure against the upper piston surface 248 . However, the tool 200 may be hydraulically activated when the annulus 70 does not contain wellbore fluid.
FIG. 4 is a cross-sectional view illustrating the slips 275 expanded radially outward into the surrounding casing 30 to secure the downhole tool 200 in the wellbore 60 . Generally, the more fluid pressure communicated down the center of the tool 200 , the more force acting against lower piston surface 246 until a point is reached where the fluid pressure in the tool 200 becomes larger than the pressure acting against the upper piston surface 248 . At this point, the fluid pressure in the tool 200 urges the piston 245 upwards toward the bent sub (not shown).
The upward movement of the piston 245 causes a collet housing 250 and lower cone 265 to move upward, thereby shearing pin 270 . After the pin 270 fails, the lower cone 265 continues to move upward to act against slips 275 . Subsequently, the slips 275 are urged upward to act against housing 285 . At a predetermined force, pin 280 , which secures the housing 285 to an upper cone 290 fails and allows the upper portion of the slips 275 to ride up a tapered portion 292 of the upper cone 290 . As additional fluid force is generated, the force acting on the lower piston surface 246 continues to increase, thereby causing the pin 295 to fail. At this point, a tapered portion 267 on the lower cone 265 is wedged under the slips 275 causing the slips 275 to move radially outward engaging the casing 30 . In this manner, the slips 275 are set into the casing 30 securing the tool 200 downhole.
FIG. 5 illustrates a packing element 305 expanded into the surrounding casing 30 to seal off a portion of the wellbore 60 . After the tool 200 is secured within the casing 30 by the slips 275 , the packing element 305 may be expanded. Generally, an uphole mechanical force is applied axially downward on the drill string (not shown) and subsequently applied to the sidetrack system (not shown), which includes the downhole tool 200 . As the mechanical force is applied to the downhole tool 200 , the slips 275 hold the lower portion of the tool 200 stationary while the bent sub 205 and a stinger 220 are urged axially downward compressing packing element 305 against a cone extension 315 . Thereafter, the packing element 305 is urged radially outward into contact with the surrounding casing 30 . In this manner, expanding the packing element 305 may seal off the wellbore 60 .
FIG. 6 illustrates the deactivation of the downhole tool 200 . The downhole tool 200 may be removed from the wellbore 60 after the milling operation is complete. Typically, the window mill (not shown), actuation apparatus (not shown), and MWD (not shown) are removed from the wellbore 60 after the milling operation, while the deflector (not shown) and the tool 200 remain downhole. Subsequently, a drill string and fishing tool (not shown) are employed in the well to attach to the deflector. Soon after attachment, the drill string and fishing tool are pulled axially upward causing the deflector to move axially upward and create an axially upward force on the downhole tool 200 . At a predetermined force, the tool 200 releasing sequence begins as a plurality of shear screws 320 fail, thereby allowing the stinger 220 , which is connected to the bent sub 205 , to move axially upward. The stinger 220 continues to move axially upward until a stinger shoulder 325 reaches the retainer shoulder 330 . At this point, the lower end of the stinger 220 is pulled out from a plurality of collet fingers 340 , thereby allowing the collet fingers 340 to collapse inward. As the releasing sequence unfolds, the bent sub 205 and the stinger 220 act as one upward moving unit causing the packing element 305 to relax, thereby releasing the seal on the surrounding casing 30 . At the same time, the tapered portion 292 on the upper cone 290 is pulled axially upward out from under the slips 275 while the slips 275 are pulled off the tapered portion 267 on the lower cone 265 , thereby allowing the slips 275 to move radially inward releasing the slips 275 from the surrounding casing 30 . In this manner, the downhole tool 200 is released from the surrounding casing 30 , thereby allowing the deflector and the tool 200 to be removed from the wellbore 60 .
FIG. 7 illustrates an alternative embodiment of a downhole tool 400 in a run-in position. As shown, downhole tool 400 has similar components as downhole tool 200 . Therefore, for convenience, similar components in downhole tool 400 will be illustrated with the same number used in the downhole tool 200 . The tool 400 will be actuated by the actuation apparatus (not shown) in the same manner as described for tool 200 . Therefore, the pressure differential is communicated through the pressure sensing line 150 into tool 400 . The differential pressure travels down the center of the tool 400 through the sub bore 210 and a mandrel bore 375 then exits out port 235 into cavity 380 . As the fluid pressure builds up in the cavity 380 , a force is created which acts upon a large piston area 360 that is formed between a plurality of outer O-rings 355 disposed on the outer surface of a piston 385 and a plurality of inner O-rings 345 disposed between the inner mandrel 370 and the piston 385 .
FIG. 8 is an enlarged view illustrating the large piston area 360 prior to setting the slips 275 . As illustrated on FIG. 8 , the inner O-rings 345 create a fluid tight seal between the piston 385 and mandrel 370 . However, the piston 385 does not initially move because an opposite force created by the hydrostatic pressure outside the tool 400 is communicated into a cavity 395 through a port 405 formed in the piston 385 and acts against an inner piston surface 390 . As more fluid pressure is communicated down the center of the tool 400 , the force acting against large piston area 360 increases until a point is reached when the fluid pressure force acting against the large piston area 360 becomes larger than the hydrostatic pressure force acting against the inner piston surface 390 . At this point, the fluid pressure force in the tool 400 causes a shear pin 410 to fail and urges the piston 385 towards the bent sub (not shown).
FIG. 9 illustrates the downhole tool 400 after the packing element 305 and slips 275 are set in the surrounding casing 30 . As illustrated, the piston 385 has moved up against slips 275 and housing 285 . At a predetermined force, pin 415 , which secures the housing 285 to an upper cone 290 fails allowing the upper portion of the slips 275 to ride up the tapered portion 292 of the upper cone 290 . As additional fluid force is pumped into the tool 400 , the force acting on the large piston area 360 continues to increase, thereby causing the pin 420 to fail. At this point, a tapered portion 425 on the piston 385 is wedged under the slips 275 causing the slips 275 to move radially outward engaging the surrounding casing 30 . In this manner, the slips 275 are set into the casing 30 securing the tool 400 downhole.
After the tool 400 is secured within the casing 30 , the packing element 305 may be expanded, thereby sealing off a portion of the wellbore 60 . Generally, an uphole mechanical force is applied axially downward on the drill string (not shown) and subsequently to the downhole tool 400 in the same manner as previously described. As the mechanical force is applied to the downhole tool 400 , the slips 275 hold the lower portion of the tool 400 stationary while the bent sub 205 and the mandrel 370 are urged axially downward compressing packing element 305 against the cone extension 315 . Thereafter, the packing element 305 is urged radially outward into contact with the surrounding casing 30 . In this manner, expanding the packing element 305 may seal off the wellbore 60 .
FIG. 10 is an enlarged view illustrating a small piston area 365 after the slips 275 are set. In addition to expanding the packing element 305 , the downward mechanical force changes the location of the mandrel 370 , thereby changing the piston area from the large piston area 360 to the small piston area 365 . The small piston area 365 is formed between the plurality of outer O-rings 355 disposed on the outer surface of the piston 385 and a middle O-ring 350 disposed on the mandrel 370 . As shown on FIG. 10 , the mandrel 370 has moved axially toward the lower end of the tool 400 . The downward movement of mandrel 370 creates a gap 430 between the inner O-rings 345 and the mandrel 370 . In other words, the gap 430 breaks the fluid tight seal created between the mandrel 370 and the piston 385 , thereby allowing fluid communication past the inner O-rings 345 into the cavity 380 . Additionally, the middle O-ring 350 disposed on the mandrel 370 contacts an inner surface 435 to create a fluid tight seal between the piston 385 and the mandrel 370 . Therefore, any fluid in the cavity 380 no longer acts upon the large piston area 360 but rather acts upon a small piston area 365 . In this respect, the smaller piston area 365 reduces the forces on the tool 400 , such as the shear release when the tool 400 is under pressure. In other words, the small piston area 365 allows the tool 400 to operate in high downhole pressure where there is a large pressure differential between the internal and the external portions of the tool 400 . Additionally, the sealing element 305 and slips 275 are shear released from the surrounding casing by shearing pin 440 in a similar manner as described for downhole tool 200 , thereby allowing the downhole tool 400 to be removed from the wellbore 60 .
FIG. 11 is a cross-sectional view illustrating an alternative embodiment of an actuation apparatus 500 in the run-in position. As shown, actuation apparatus 500 has similar components as actuation apparatus 100 . Therefore, for convenience, similar components in actuation apparatus 500 will be illustrated with the same number used in the actuation apparatus 100 . The apparatus 500 includes an inner sleeve 515 that moves between a first position and a second position. A biasing member called an inner spring 505 biases the inner sleeve 515 upward in the first position. The spring 505 is constructed and arranged to shift inner sleeve 515 to the second position at a predetermined flow rate through the actuation apparatus 500 . The force exerted upon the inner spring 505 is determined by the flow rate and pressure of fluid through apparatus 500 .
Inner sleeve 515 includes restriction 120 in the inner diameter thereof, which serves to restrict the flow of fluid through tubular member 105 . As fluid passes through actuation apparatus 500 and encounters restriction 120 , the pressure of the fluid drops in the region 160 directly below restriction 120 and increases in a region 155 directly above restriction 120 thereby creating a pressure differential between the two regions 155 , 160 . Conversely, the velocity of the fluid decreases in area 155 and increases in area 160 . The inner sleeve 515 further includes O-rings 540 , 545 disposed on the outer surface of the inner sleeve 515 to create a fluid tight seal between the inner sleeve 515 and an outer sleeve 520 . Additionally, the pressure port 140 is formed in a wall of tubular member 105 . Connected in fluid communication to pressure port 140 through the fitting 145 is the pressure sensing line 150 . As depicted in FIG. 11 , when the upper actuation apparatus 500 is not activated, the pressure sensing line 150 is in communication with lower pressure region 160 below the restriction 120 .
The outer sleeve 520 is disposed on the inner surface of the actuation apparatus 500 . The outer sleeve 520 is shifts between a first and a second position. As illustrated, the outer sleeve 520 is biased in the first position by an outer spring 510 . The outer spring 510 is constructed and arranged to allow the outer sleeve 520 to shift to the second position at a predetermined flow rate through the actuation apparatus 500 . As depicted, O-rings 530 , 535 are disposed around the outer surface of the outer sleeve 520 to create a fluid tight seal between the outer sleeve 520 and the tubular member 105 . Additionally, an upper port 525 and a lower port are formed in the outer sleeve 520 to allow fluid communication between regions 155 , 160 and the port 140 .
FIG. 12 is a cross-sectional view illustrating the flow rate through the actuation apparatus 500 to operate the MWD device (not shown). The actuation apparatus 500 is constructed and arranged to pass a flow rate of fluid therethrough sufficient to operate a MWD device located in a running string without actuating a hydraulically operated tool (not shown) therebelow. During operation of the MWD, fluid is pumped through the actuation apparatus 500 at a level that creates a force in the restriction 120 sufficient to overcome the inner spring 505 , causing the inner sleeve 515 to move to the second position. At this point, the fluid communication through the lower port 550 and the port 140 is blocked as illustrated on FIG. 12 . In this manner, the MWD may be operated without actuating the downhole tool. After operation of the MWD, the flow rate may be increased to that level that creates a force sufficient to overcome the outer spring 510 as shown in FIG. 13 .
FIG. 13 is a cross-sectional view illustrating the flow rate through the actuation apparatus 500 to actuate the downhole tool (not shown). In order to actuate the apparatus 500 , fluid at a predetermined flow rate is applied through tubular member 105 . As the fluid moves through restriction 120 , pressure rises in region 155 . At a predetermined flow rate, the force at restriction 120 is adequate to overcome the outer spring 510 . Thereafter, the outer sleeve 520 will move to the second position against shoulder 530 as illustrated in FIG. 13 . At the same time, the actuation apparatus 500 places the pressure sensing line 150 in fluid communication with region 155 above the restriction 120 . In this respect, the pressure sensing line 150 is exposed to the higher pressure created by the flow of fluid through restriction 120 . The pressure sensing line 150 communicates the higher pressure in the same manner as described in the actuation apparatus 100 .
FIG. 14 is a cross-sectional view illustrating the flow rate through the actuation apparatus 500 after the downhole tool (not shown) is actuated. As the flow rate decreases, the force in the restriction 120 becomes insufficient to overcome the outer spring 510 , causing the outer sleeve 520 to move from the second position to the first position. As further illustrated, the port 140 remains isolated to prevent the possibility of erosion and damage to the downhole tool during the milling operation. Subsequently, the flow rate is further decreased allowing the apparatus 500 to return to the run-in position as illustrated on FIG. 11 .
FIG. 15 is a cross-sectional view illustrating an alternative embodiment of an actuation apparatus 600 . As shown, actuation apparatus 600 has similar components as actuation apparatus 100 . Therefore, for convenience, similar components in actuation apparatus 600 will be illustrated with the same number used in the actuation apparatus 100 . As previously discussed for tool 200 , the hydrostatic pressure enters the housing port 260 from wellbore fluid in the annulus (not shown). Alternatively, the hydrostatic pressure may be communicated to the housing port 260 through a low-pressure line 605 . The low-pressure line 605 is connected to a fitting 615 housed in a low-pressure port 610 formed in a wall of tubular member 105 . The low-pressure port 610 is in fluid communication with region 160 directly below restriction 120 . In this respect, the actuating apparatus 600 completely eliminates any effective pressure drop across the mill face, thereby providing an effective means of actuating the tool 200 .
FIG. 16 is a cross-sectional view illustrating an alternative embodiment of an actuation apparatus. As shown, actuation apparatus 700 has similar components as actuation apparatus 100 . Therefore, for convenience, similar components in actuation apparatus 700 will be illustrated with the same number used in the actuation apparatus 100 . As previously discussed for actuation apparatus 100 , the tool (not shown) is activated or triggered by a differential pressure in regions 155 , 160 created by fluid flow through the restriction 120 . However, flow rate may vary due to pulsing of the pumps and other restrictions in the flow line. Therefore, the embodiment illustrated in actuation apparatus 700 contains a control feature that allows the tool to be activated or triggered at a predetermined pressure. As shown, a single use valve or a rupture disk 705 is placed in the pressure port 140 . In addition, a fluid port 710 fluidly connects region 160 to the pressure port 140 to form a Y block. In the embodiment shown, the single use valve is a rupture disk to permit activation of the tool at a predetermined pressure. However, other forms of single use valves may be employed, such as a pressure relief valve, so long as they are capable of allowing activation of the tool at a predetermined pressure. In operation, the actuation apparatus 700 functions in the same manner as previously discussed for actuation apparatus 100 . However, the rupture disk 705 in the actuation apparatus 700 buffers out fluid pulses created by the pumps by requiring a threshold trigger pressure to be reached prior to activation of the tool. In this respect, the actuation apparatus 700 provides an external control feature to activate the tool rather than relying on the shear screws internal to the tool.
FIG. 17 is a cross-sectional view illustrating an alternative embodiment of an actuation apparatus 800 with a hydraulic isolation device 805 . As shown, actuation apparatus 800 has similar components as actuation apparatus 100 . Therefore, for convenience, similar components in actuation apparatus 800 will be illustrated with the same number used in the actuation apparatus 100 . In this embodiment, the restriction 120 is used as a seat 810 for a hydraulic isolation device 805 . In the embodiment shown, the hydraulic isolation device 805 is a ball. However, other forms of hydraulic isolation devices may be employed, such as a dart, so long as they are capable of restricting the flow of fluid through the tubular member 105 . The hydraulic isolation device 805 may be dropped from the surface of the wellbore (not shown) into the drill string (not shown). Thereafter, the hydraulic isolation 805 device would flow through the tubular member 105 and land in the seat 810 . As fluid is pumped through the drill string and subsequently through the actuation apparatus 800 , the hydraulic isolation device 805 would restrict the flow through the tubular member 105 and create a pressure in the region 155 . The higher pressure is communicated through the slit 115 of the sand tube 110 to the pressure port 140 and subsequently through the pressure sensing line 150 to activate the tool (not shown) as described in the previous paragraph.
FIG. 18 is a cross-sectional view illustrating the removal of the hydraulic isolation device 805 from the actuation apparatus 800 . After the tool (not shown) has been hydraulically actuated, the fluid flow rate may be increased to remove the hydraulic isolation device 805 from the seat 810 . For example, if the isolation device 805 is a ball, the flow rate may be increased to create a force on the ball, whereby at a predetermined force the ball explodes and the residue is washed out through the flow ports 135 as illustrated in FIG. 18 .
In operation, a sidetrack system is disposed in a wellbore. The sidetrack system is useful for offsetting a wellbore by directing a drill bit or cutter at an angle from the existing wellbore. The sidetrack system typically includes a window mill, an actuation apparatus, a MWD, a deflector and a downhole tool such as an anchor-packer. To operate the sidetrack system and actuate the downhole tool fluid is pumped from the surface of the wellbore through a drill string and subsequently through the actuation apparatus. As fluid passes through the actuation apparatus and encounters a restriction, the pressure of the fluid drops in a region directly below the restriction and increases in the region directly above the restriction, thereby creating a pressure differential between the two regions. The pressure differential is communicated into a slit in the sand tube through the annular area into the pressure port and subsequently through the pressure sensing line into the center of the tool. Thereafter, the fluid pressure enters a cavity through a body port that formed at the lower end of the lower body. As the fluid pressure builds up in the cavity a force is created which acts upon a lower piston surface.
Generally, the more fluid pressure communicated down the center of the tool, the more force acting against lower piston surface until a point is reached when the force on the lower piston surface becomes larger than the opposite force acting against the upper piston surface. At this point, the piston is urged upwards toward the bent sub. The movement of the piston causes a plurality of shear members to fail and subsequently urges the tapered portions on the lower cone and upper cone to wedge under the slips causing the slips to move radially outward into contact with the casing. Thereafter, an uphole mechanical force is applied axially downward on the drill string and subsequently applied to the downhole tool. As the mechanical force is applied to the downhole tool, the slips hold the lower portion of the tool stationary while a bent sub and a stinger are urged axially downward compressing the packing element against the cone extension, thereby causing the packing element radially outward into contact with the surrounding casing. In this manner, the downhole tool is operated in the wellbore.
The downhole tool may be removed from the wellbore after the milling operation is complete. Typically, the window mill, actuation apparatus, and MWD are removed from the wellbore after the milling operation, while the deflector and the downhole tool remain in the wellbore. Subsequently, a drill string and fishing tool are employed in the well to attach to the deflector. Soon after attachment, the drill string and fishing tool are pulled axially upward causing the deflector to move axially upward and create an axially upward force on the downhole tool. The axially upward force causes the packing element and slips to release allowing the downhole tool and the deflector to be removed from the wellbore.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | The present invention generally relates to an apparatus and method for operating a tool in a wellbore. In one aspect, the apparatus includes a hydraulically operated tool and a wellbore tubular both in communication with a pressure sensing line. The hydraulically operated tool is responsive to a combination of a fluid pressure in the pressure sensing line and a manipulation of the wellbore tubular, such response causing the tool to operate within the wellbore. In another aspect, the invention provides a method for anchoring a well tool in a wellbore. The method includes the steps of lowering the well tool into the wellbore on a tubular string, flowing fluid through the tubular string to begin anchoring the well tool, and manipulating the tubular string to complete the anchoring of the well tool. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/FR2011/052297 filed on Oct. 3, 2011, which claims the benefit of FR 10/58712, filed on Oct. 25, 2010. The disclosures of the above applications are incorporated herein by reference.
FIELD
[0002] The present disclosure relates to a turbojet engine nacelle for an aircraft.
BACKGROUND
[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0004] An aircraft is moved by several turbojet engines each housed in a nacelle also housing a set of related actuating devices connected to its operation and performing various functions, when the turbojet engine is operating or stopped. These related actuating devices may in particular comprise a mechanical thrust reverser actuating system.
[0005] A nacelle generally has a tubular structure including an air intake in front of the turbojet engine, a middle section designed to surround a fan of the turbojet engine, a rear section housing thrust reverser means and designed to surround the combustion chamber of the turbojet engine, and generally ends with a jet nozzle whereof the outlet is situated downstream of the turbojet engine (so-called primary nozzle).
[0006] Modern nacelles are often designed to house a dual flow turbojet engine capable of generating, by means of the rotating fan blades, a hot air flow (also called primary flow) coming from the combustion chamber of the turbojet engine.
[0007] A nacelle generally includes an outer structure, called outer fixed structure (OFS), that defines, with a concentric inner structure of the rear section, called inner fixed structure (IFS), surrounding the structure of the turbojet engine strictly speaking behind the fan, an annular flow channel, also called secondary tunnel, aiming to channel a flow of cold air, called secondary flow, that circulates outside the turbojet engine.
[0008] Around the turbojet engine, the inner structure delimits a compartment and ventilation areas, the primary purpose of which is to refresh the air circulating between the IFS and the engine.
[0009] The inner structure and the jet nozzle delimit an outlet cross-section of the fan of the engine compartment.
[0010] Several cool air sources (taken from the secondary flow) supply the ventilation compartment, circulate along the turbojet engine, where they heat up before being discharged through the ventilation outlet.
[0011] In general, the ventilation inlet and outlet cross-sections are sized so as to ensure acceptable ventilation and pressure in the ventilation compartment along the turbojet engine.
[0012] Document WO 2009/024660 describes such a system for regulating the ventilation air and the pressure in the ventilation compartment. The described system also makes it possible to accommodate certain deformations of the turbojet engine during flight.
[0013] More specifically, document WO 2009/024660 describes a turbojet engine nacelle, comprising a rear section having an inner structure designed to surround a rear part of an engine compartment and to delimit, with a jet nozzle, a calibrated outlet cross-section of the ventilation of the engine compartment, using separating means arranged in the outlet cross-section, characterized in that the separating means can be broken down into rigid separating means designed to ensure constant separation, and compensating means designed so as to be able to adapt to the relative movements of the turbojet engine with respect to the nacelle.
[0014] It should, however, be noted that the turbojet engine is equipped with high pressure air discharge valves allowing it to regulate its performance. Generally, these discharge valves are situated inside the inner structure (IFS) and emerge inside the ventilation compartment.
[0015] Thus, in the case where one or more valves discharged in that ventilation compartment for certain flight cases, a major overpressure results that must be absorbed and regulated.
[0016] Another case of accidental overpressure may also be a burst duct incident of the turbojet engine.
[0017] Furthermore, these overpressures cause irregular loads of the inner structure that work in fatigue. It may also result in deformations of said inner structure and, consequently, a disruption of the flow of the air flow to the outside of the nacelle amounting to losses in aerodynamic efficiency.
[0018] It has appeared that the current solutions do not account for these discharge valves, and there is therefore a need for a solution making it possible to better account for these additional constraints.
[0019] More specifically, the current solutions do not allow active management of the ventilation outlet.
SUMMARY
[0020] One aspect of the present disclosure is to provide a system making it possible to adapt the ventilation outlet to the maximum possible flight and pressure scenarios.
[0021] To that end, the present disclosure relates to a turbojet engine nacelle comprising a rear section having an inner structure, designed to surround a rear part of an engine compartment and to delimit, with a jet nozzle, an outlet cross-section of the ventilation of the engine compartment, characterized in that it comprises at least one moving element associated with at least one corresponding control means, said moving element being movable between a retracted position in which the ventilation outlet cross-section is maximal, and an engaged position in which the moving element at least partially reduces the ventilation outlet cross-section relative to the retracted position, said control means being able to move the moving element between the retracted and engaged positions.
[0022] Thus, by providing a moving element whereof the position is controllable, the ventilation outlet cross-section can be adjusted precisely and can easily be adapted to all flight and incident cases that may cause a pressure variation in the ventilation compartment of the turbojet engine.
[0023] Advantageously, the moving element can be moved into at least one intermediate position between its retracted and engaged positions. This is a discrete movement of the moving element.
[0024] Also advantageously, the moving element can be moved continuously between its retracted and engaged positions.
[0025] In another form, the moving element is mounted translatably. According to a first alternative aspect of the present disclosure, the moving element is translatable along a substantially longitudinal axis of the nacelle.
[0026] According to a second alternative aspect, the moving element is translatable in a substantially radial direction of the nacelle.
[0027] Alternatively, the moving element is rotatably mounted around a pivot axis. This may in particular be a check valve.
[0028] According to one form, the moving element is movably mounted on an exhaust shroud at the jet nozzle.
[0029] According to another form, the moving element is movably mounted on a wall of the inner structure.
[0030] The moving element is movably mounted between the inner structure and the jet nozzle in still another form of the present disclosure.
[0031] Advantageously, the moving element is made in several sectors and extends over at least part of the periphery of the ventilation outlet.
[0032] Alternatively, the moving element is made in a single sector that is at least partially peripheral.
[0033] Advantageously, the control means of the movable element comprise at least one electric driving means.
[0034] Alternatively, the control means of the moving element comprise at least one pneumatic or hydraulic driving means.
[0035] It should be noted that, in light of the temperature and pressure conditions near the turbojet engine, the presence of actuating and control means is made difficult.
[0036] Advantageously, the control means of the moving element comprise at least one driving means substantially at the ventilation pressure. In this way, it is possible to implement an at least partially automatic regulation of the pressure in the ventilation compartment.
[0037] In one form, the moving element is mounted against elastic return means toward its retracted position (maximum outlet cross-section) or engaged position (minimal outlet cross-section).
[0038] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0039] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
[0040] FIG. 1 is a diagrammatic longitudinal cross-sectional view of the nacelle according to the present disclosure in the closed state,
[0041] FIG. 2 is a partial enlarged diagrammatic view of a rear section of the nacelle of FIG. 1 ,
[0042] FIG. 3 is a partial diagrammatic perspective view from the rear of the nacelle of FIG. 1 ,
[0043] FIG. 4 is a partial longitudinal cross-sectional view of a moving element equipping a ventilation outlet of the nacelle of FIG. 1 according to the present disclosure, and
[0044] FIGS. 6 to 13 are partial diagrammatic and longitudinal cross-sectional views of alternative forms of the moving element equipping a ventilation outlet of a nacelle according to the present disclosure.
[0045] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
DETAILED DESCRIPTION
[0046] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
[0047] A nacelle 1 of an aircraft according to the present disclosure, as diagrammatically shown in FIG. 1 , comprises, in a known manner, a front air intake section 2 , a middle section 3 designed to surround the fan (not visible), and a rear section 4 designed to surround an engine compartment 5 and ending with a jet nozzle 6 whereof the outlet is situated behind the turbojet engine.
[0048] This nacelle 1 comprises an outer structure 7 , called OFS (Outer Fixed Structure), which defines an annular flow channel 8 with a concentric inner structure 9 , called IFS (Inner Fixed Structure), surrounding a downstream part 5 of the turbojet engine behind the fan.
[0049] By way of illustration, it will be noted that the outer structure of the downstream section 4 shown is equipped with a thrust reverser device. Of course, this may also be a nacelle not equipped with a thrust reverser device, called a smooth structure.
[0050] The inner structure 9 defines a ventilation compartment 10 around the turbojet engine 5 , allowing the circulation of a flow of cooling air (Arrows) around the turbojet engine by taking air from the tunnel 8 .
[0051] The air taken is discharged from the ventilation compartment 10 through a ventilation outlet 11 , delimited by a separation between the inner structure 9 and the jet nozzle 6 and maintained by separating means (not visible).
[0052] According to the present disclosure and like one form shown in FIGS. 4 and 5 , the nacelle 1 comprises at least one moving element 15 , associated with at least one corresponding control means (not visible), said moving element 15 being movable between a retracted position in which the ventilation outlet cross-section 11 is maximal, and an engaged position in which the moving element 15 at least partially reduces the ventilation outlet cross-section 11 relative to the retracted position, said control means being able to move the moving element 15 between the retracted and engaged positions.
[0053] The outlet cross-section 11 can therefore be actively and dynamically controlled to regulate the air pressure in the ventilation compartment 10 and to adapt to overpressure or pressure decrease cases.
[0054] The moving element can be designed to adopt one or more discrete positions between its retracted position and its engaged position, or to be moved continuously along a travel path.
[0055] As shown in FIG. 5 , it should be noted that as a general rule, the outlet cross-section 11 does not extend over the entire periphery of the nozzle 6 and the inner structure 9 , an upper portion being made sealable for fire packaging reasons.
[0056] The moving element 15 can be made in a single piece or several sectors, which may optionally be independent.
[0057] The shape of the moving element 15 may assume the desired form and may be adapted as a function of flow constraints in particular. It may in particular be incorporated into the enclosure of the structure 6 , 9 on which it is mounted.
[0058] It is thus, for example, possible to provide a beveled moving element 15 , 155 , 158 , 159 , a moving element 151 , 152 with a substantially rectangular cross-section, a rounded moving element 153 , a pivoting flap 154 , 156 , etc.
[0059] According to one form, as shown in FIGS. 4 , 6 to 9 , the moving element 15 , 151 , 152 , 153 , 154 is movably mounted on an exhaust shroud at the jet nozzle 6 .
[0060] According to another from, as shown in FIGS. 10 to 12 , the moving element 155 , 156 , 158 is movably mounted on the inner structure 9 .
[0061] According to still another form, as shown in FIG. 13 , the moving element 159 is movably mounted independently between the inner structure 9 and a shroud of the jet nozzle 6 .
[0062] The movement of the moving element can also be of a different nature.
[0063] According to a first alternative form ( FIGS. 4 , 6 , 7 , 10 , 12 and 13 ), the moving element 15 , 151 , 152 , 155 , 158 , 158 is translatably mounted.
[0064] The guiding of the moving element may be done by means of a rail/guideway system, as shown in FIG. 5 (enlarged portion).
[0065] The moving element may be movable along a substantially longitudinal axis of the nacelle, but also along a radial axis of the nacelle or a combination of the two.
[0066] According to a second alternative form ( FIGS. 9 , 11 ), the moving element 154 , 156 is rotatably mounted around a pivot axis like a check valve.
[0067] Of course, these forms are not limiting and equivalent means known by those skilled in the art can also be used.
[0068] The moving element 15 may be driven by any known actuating means, adapted to the surrounding temperature and pressure conditions.
[0069] It is in particular possible to provide electric, or pneumatic or hydraulic driving means.
[0070] Advantageously, the driving and/or control means will be offset from the moving element, in particular in a so-called cold zone, i.e., toward the upstream direction of the turbojet engine 5 and the ventilation compartment 10 . In such a case, it is possible to provide driving by traction cable or rigid return such as a Cardan joint system.
[0071] By way of complementary characteristics that may be generalized to the described forms, FIGS. 6 and 12 show the placement of local stops 161 positioned at the interface between the inner structure 9 and the nozzle shroud 6 . The stops aim to make it possible to guarantee minimal separation between said inner structure 9 and the nozzle 6 in the case of relative deformation of the two structures 6 , 9 .
[0072] FIGS. 8 and 9 show forms using pressure-sensitive driving means in the ventilation compartment 10 .
[0073] More specifically, FIG. 8 provides, as moving element 153 , an inflatable element, like a bladder, which, by inflating, at least partially obstructs the ventilation outlet 11 more or less. One such type of system is particularly useful with control means of the pneumatic or hydraulic type. The pneumatic or hydraulic system may be associated with the engine or may be dedicated and autonomous. Furthermore, this inflatable element 153 can be elastic and tend to return automatically toward a default position, corresponding to a minimal or maximal outlet cross-section 11 , in the event its supply pressure is released.
[0074] The aspect of FIG. 9 shows a moving element 154 , made in the form of a pivoting flap, mounted against a return spring 163 tending to return it toward a retracted position in which the outlet section 11 is maximal. This flap is actuated by a mechanical retractable push-piece 164 . This push-piece may be electric, hydraulic or pneumatic. The actuation of the flap may be done upstream or downstream of its axis of articulation. Furthermore, one push-piece can drive several flaps.
[0075] Likewise, FIG. 11 shows an elastic flap 156 (blade spring, for example) forced by a push-piece 157 . The blade spring may have one end made up of several strips, for example formed by channels in the blade.
[0076] In FIG. 12 , the moving element 158 is guided on the inner structure 9 following a rectilinear movement in the axis of the nacelle. Such a configuration makes it possible to design a single-piece structure of the moving element 158 .
[0077] In FIG. 13 , the moving element 159 is guided either on the inner structure IFS 9 or on the jet nozzle structure. The moving element 159 , in its translation, reduces the passage section simultaneously between the two structures.
[0078] Furthermore, in the case of a so-called D-Duct nacelle structure, i.e., whereof the outer structure OFS comprises two semi-cylindrical half-cowls articulated in an upper area at an attachment mast, the moving element 158 can be made continuously from a sector covering the upper area without ventilation to the lower area of the inner structure 9 .
[0079] In the case of a structure with a so-called O-duct downstream section 4 , i.e., formed by a single substantially cylindrical sliding cowling, the moving element 158 may be formed by a sector connecting the two upper areas without ventilation.
[0080] Although the present disclosure has been described relative to specific example forms, it is of course in no way limited thereto and encompasses all technical equivalents of the described means, as well as combinations thereof if they are within the scope of the disclosure. | A turbojet engine nacelle includes a rear section having an internal structure. The internal structure surrounds a rear part of an engine compartment and delimits, with an ejection jet pipe, an outlet cross section for the ventilation of the engine compartment. The engine nacelle includes a moving element associated with a corresponding controller. The moving element is able to move between a withdrawn position in which the outlet cross section for ventilation is at a maximum and an engaged position in which the moving element partially reduces the outlet cross section for ventilation by comparison with the retracted position. The controller is capable of moving the moving element between the retracted and engaged positions. | 5 |
TECHNICAL FIELD
The present invention relates to under-cabinet lighting fixtures. More particularly, the present invention relates to puck-type under-cabinet lighting fixtures which are readily installed with a cap to provide lighting from mounting surfaces.
BACKGROUND OF THE INVENTION
Lights and lighting provide useful general illumination of interior and exterior spaces in homes and buildings, as well as ornamental and artistic treatments for decorative purposes. These purposes include lighting functions for accent and interior ornamental design functions, highlights for artwork, illuminating work areas, and other functions. Often furniture or cabinetry have lights for illuminating articles held within the furniture or cabinets. For cabinets, and in particular kitchen wall cabinets, lighting fixtures are often mounted to a lower exterior surface or recessed therein, for illuminating countertop surfaces below the cabinets.
One type of lighting fixture is known as an under-cabinet puck light. These lights have generally cylindrical disc-shaped housings. The housings contain a reflector, a lamp socket with a light emitting bulb, and a glass lens for transmitting light from the housing to the countertop surface below the cabinet. The socket connects to a supply of electrical current. The lights provide pools of lights to the countertop surface, and are used typically in kitchens and display cabinetry for providing light on the working surfaces in kitchens as well as for use in highlighting articles in display cabinets. Under-cabinet puck lights that are commercially available operate with 12 volt direct current, or more recently, as disclosed in my U.S. Pat. No. 6,491,413, operate on 120 volt (line) alternating current. Generally, the puck-type lighting fixtures are provided commercially as after-market installation devices.
My U.S. Pat. No. 6,491,413 discloses an improved line voltage puck lighting fixture. The lighting fixture provides an under-cabinet lighting fixture for surface and recessed mounting and operating on high line voltage for increased illumination with controlled transfer of the heat communicated from the fixture, with a housing that defines an open end opposing a base having a thickened portion. The housing defines a plurality of openings in the base, and a plurality of projections extending from an edge of the housing. A reflector defining a dished cavity seats on the projections to define a gap between the reflector and the housing. A lamp socket received in the housing engages a lamp bulb that is substantially in alignment with the thickened portion of the base and disposed in the dished cavity. A cap received on the housing has a plurality of spaced-apart ports. The high voltage lighting fixture defines a pathway for communicating air through the ports, the gap, and the openings, past the reflector for communicating heat from the reflector to ambient air.
The lighting fixture of this type works well for line voltage applications, however, there are other drawbacks experienced during use. For instance, the screws connecting the reflector to the base tend occasionally to reduce the gap between the reflector flange and the edge of the base. This made it more difficult to install the cap. Also, metal screws tended to transmit heat from the reflector to the base, rather than allowing heat to flow away from the base through the vents.
Accordingly, there is a need in the art for an improved under-cabinet lighting fixture for surface and recessed mounting installed with a cap that easily connects to the reflector and base and that better allows heat to flow away from the base through the vents to the ambient air. It is to such that the present invention is directed.
BRIEF SUMMARY OF THE PRESENT INVENTION
The present invention provides an under-cabinet lighting fixture having a housing with a base and an opposing openable end, and a flange spaced-apart from an edge at the openable end that extends radially from an exterior surface of the housing. A reflector defines a dished cavity and seats on the edge of the housing, thereby defining a recess between an edge portion of the reflector and the flange. A light source is received within the housing. A light transmissive cover received on the housing has a tab received in the recess for guiding the rotation of the cover thereon.
Objects, advantages, and features of the invention will be come apparent upon a reading of the following detailed description of the present invention in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a light fixture according to the present invention.
FIG. 2 is a perspective top view of an alternate embodiment of the housing for the light fixture shown in FIG. 1 .
FIG. 3 is a perspective bottom view of the housing illustrated in FIG. 2 .
FIG. 4 is a perspective view illustrating details of a portion of the housing of the light fixture shown in FIG. 1 .
FIG. 5 is a side cut-away view illustrating features of the light fixture shown in FIG. 1 .
FIG. 6 is a perspective view of a surface-mounting installation of the light fixture shown in FIG. 1 .
FIG. 7 is a perspective view of a recessed-mounting installation of the light fixture shown in FIG. 1 .
DETAILED DESCRIPTION
Referring now in more detail to the drawings in which like parts have like identifiers, FIG. 1 illustrates in exploded perspective view a light fixture 10 according to the present invention. The light fixture 10 readily mounts as an under-cabinet lighting fixture or recessed mounting, as discussed below. The light fixture 10 comprises a housing 12 having an open end 14 with a flange 16 extending laterally therefrom. The flange 16 is spaced-apart from an edge of the housing at the open end. As a result, a ridge or wall 18 extends around the edge from a first surface of the flange 16 longitudinally relative to the housing 12 . The wall 18 defines thickened portions 20 that each defines a hole 22 . As best illustrated in FIG. 4 , each hole 22 is recessed so that a threaded screw 24 received in the hole 22 sits flush with a distal surface 23 of the wall 18 . Four stops 26 extend laterally from a outward side of the wall 18 . A pair of opposing tabs 28 are defined in a side wall of the housing 12 . The tabs 28 extend at a first end from the side wall for flexible movement relative to the housing 12 , for a purpose discussed below. The tabs 28 include an outwardly extending tip.
The housing 12 defines a partially closed bottom 30 having a plurality of openings 32 . In the illustrated embodiment, the openings 32 are aligned slots defining concentric rings arranged radially. Four semisperical legs 34 extend from an outer surface of the bottom 30 . A central portion 36 defines a thickened portion of the bottom 30 , as best illustrated in FIG. 3 . In the illustrated embodiment, the thickened portion 36 extends slightly from an exterior surface of the bottom, or about 0.06 inches from the surface of the bottom 30 , to approximately double the thickness of the wall of the housing 12 in the central portion 36 . The side wall of the housing defines a slot 38 adjacent the bottom 30 for receiving a pair of electric wires 40 . A pair of lugs 42 extend upwardly from opposing sides of the slot 38 as illustrated in FIG. 2 . A U-shaped brace 44 defines a pair of opposing holes at distal ends. The brace 44 connects to the lugs 42 with screws entering the lugs 42 through the holes for securing the electrical wires 40 in the slot 38 . A pair of posts 46 extend between the open end 14 and the bottom 30 on opposing sides of the housing 12 . The posts 46 each define a longitudinal bore. Studs 48 extend from the bottom 30 and are spaced-apart from each of the respective posts 46 .
A pair of tabs 50 extend upwardly from the bottom 30 . Each tab 50 defines an angled hook at a distal end. A plate 52 extends upwardly from the bottom 30 radially inwardly from the side wall of the housing and between the tabs 50 . The tabs 50 , the plate 52 , and a portion of the wall of the housing 12 cooperatively define a recess that receives a lamp socket 56 . The lamp socket 56 defines opposing openings 57 for receiving the ends of the electrical wires 40 and lamp post sockets or openings 58 for engaging pins of a lamp or light bulb 60 .
The lighting fixture 10 includes a reflector 70 . The reflector 70 defines a dish-shaped cavity 71 with a laterally extending flange 74 . The face of the dish-shaped cavity 71 defines a plurality of facets 73 for reflecting light. The flange 74 defines a plurality of spaced-apart openings 76 . The flange 74 defines slots 78 open to an exterior edge. The slots 78 align with the holes 22 in the wall 18 of the housing 12 . The flange also defines a pair of opposing holes 80 . The holes 80 align with the posts 46 . A side portion of the cavity 71 defines an opening 82 which is sized for receiving a portion of the lamp socket 56 . The flange 74 defines a pair of opposing flats 84 . A pad 86 of an insulative material is disposed between the bottom 30 and the reflector 70 . The reflector 70 , such as a stamped aluminum member, seats on the surface 23 of the wall 18 with the cavity 71 within the housing 12 . The openings 76 provide air flow pathways from the cavity 71 .
A cap 90 closes the housing 12 . The cap 90 defines a central opening 92 . Fingers 94 extend from an inner surface of the cap 90 adjacent the central opening 92 . The fingers 94 angle towards the opening 92 . The fingers 94 cooperatively engage a glass lens 96 . In the illustrated embodiment, the glass lens 96 is a UV filter for reducing emissions from halogen light bulbs used with the light fixture 10 . A plurality slot-like of openings 98 are defined in the cap 90 . A pair of tabs or ears 99 extend radially inwardly from a skirt of the cap 90 on opposing sides.
The lighting fixture 10 described above is particularly useful for recessed mounting in cabinets, as discussed below, with a surface can 100 for surface mounting of the fixture 10 . The can 100 defines an annular ring 102 having an inwardly extending flange 104 . The flange defines three slots 108 . Opposing flanges 109 extend on the interior of the can 100 in alignment with the slots 108 . The slots 108 align with the slots 78 in the reflector 70 for a purpose discussed below. Two pairs of side flanges 110 , 112 extend on the interior from opposing sides of the ring 102 . A plurality of pins 114 extend from the ring 102 opposing the flange 104 . The pins 114 space the can 100 from a surface to which the can 100 mounts and defines airflow pathways between the light fixture 10 and the surface. An alternate embodiment does not include the pins 114 , but defines a plurality of spaced-apart holes in the ring 102 for airflow out of the can 100 . The ring 102 defines an opening 116 . A pair of ears 118 extend from opposing portions of the ring 102 . The ears 118 define openings 119 for receiving screws to mount the can 100 to a surface.
FIG. 2 is a perspective top view of an alternate embodiment of the housing 12 for the light fixture shown in FIG. 1 . In this embodiment, the housing includes opposing tabs 120 which each define a keyed opening 122 . The keyed opening includes a hole and a lateral slot for receiving a screw head and shaft for securing the housing 12 to a mounting surface.
FIG. 3 is a perspective bottom view of the housing 12 illustrated in FIG. 2 . The housing 12 defines a socket 124 in the side wall and bottom having opposing retaining clips for receiving and engaging a stem (not illustrated) for connecting the housing 12 to an electrical junction box as disclosed in my U.S. Pat. No. 6,431,722.
FIG. 5 is a side cut-away view illustrating features of the light fixture 10 shown in FIG. 1 . The reflector 70 seats on the surface 23 of the wall 18 . The housing 12 receives the cavity 71 . The ear 99 of the cap 90 is received in a gap between the flange 74 of the reflector 70 and the flange 16 of the housing 12 . The cap 90 is installed by aligning the ears 99 with the flats 84 of the reflector and rotating the cap 90 .
FIG. 6 is a perspective view of a surface-mounting installation of the light fixture 10 . In this mounting, the can 100 mounts with screws extending through the openings 119 in the ears 118 . The can 100 receives the housing 12 that includes the reflector 70 . FIG. 7 is a perspective view of a recessed mounting installation of the recessed lighting fixture 10 . In this installation, the can 100 is not used. Rather, the housing 12 is secured within a recess 132 in a mounting surface 134 with screws 24 extending through the slots 78 aligned with the openings 22 in the flange 16 . In both installations, screws pass through the openings 80 in the reflector 70 and into the posts 46 to attach the reflector to the housing 12 . The cap 80 closes the housing 12 .
For use, the electric wires 40 pass through the slot 38 in the housing 12 and separate. The separate wires loop through the respective studs 48 adjacent the posts 46 on opposing sides of the housing 12 . The distal ends of the electric wires 40 electrically connect to the socket 56 through the opposing side openings 57 . The socket 56 is secured in a recess by the tabs 50 . Screws extending through the holes in the brace 44 connect to the lugs 42 . The brace secures the electric wires 40 in the slot 38 .
The insulative pad 86 sits on the thickened central portion 36 . The reflector 70 inserts into the housing 12 and seats on the pad 86 . Screws extend through the openings 80 and into the posts 46 to attach the reflector 70 to the housing 12 . The socket 56 receives the bulb 60 .
As illustrated in FIG. 7 , the housing 12 may be installed for recess-mounting in the annular recess 132 of the surface 134 . An appropriate sized hole or recess is created in the selected location. The electrical wires 40 pass through the recess 132 . The recess 132 receives the housing 12 . The flange 16 overlaps a portion of the surface 134 . The screws 24 extend past the slots 78 and through the openings 20 to engage the surface 134 . The heads of the screws 24 seat recessed below the surface 23 of the wall 18 to secure the housing 12 in place. The cap 90 is attached to the distal end of the housing 12 . This is accomplished by pushing the ears 99 past the opposing flats 80 and into the gap between the flanges 16 and 74 . Rotation of the cap 90 moves the ears 99 along the gap. The stops 26 keep the cap 90 from over-rotation. The electric wires 40 connect to a source of electric current.
The lighting fixture 10 of the present invention also surface mounts as illustrated in FIG. 6 with the housing 12 received within the open end of the can 100 . This is accomplished by locating a selected position for the fixture 10 on the mounting surface 130 . The electrical wires 40 extend through an opening in the surface 130 . The housing 12 connects to the reflector 60 by screws extending through the openings 80 and engaging the posts 46 . Screws extending through the openings 119 in the ears 118 attach the can to the surface 130 . The can 100 secures to the surface 120 when the heads of the screws 18 are flush with the surface of the ridge 18 . The can 100 then receives the housing 12 which is pushed into the can 100 . The tabs 28 flex and allow the housing 12 to seat into the can 100 . The flanges 110 , 112 receive the tabs 28 therebetween to prevent rotation of the housing 12 . It is to be appreciated that the light fixture 10 may also be further secured with the screws 24 extending through the aligned slots 78 and openings 20 . The electrical wires 40 connect to a source of electrical current for powering the light fixture 10 . The pins 114 extending from the ring 102 define airflow pathways between the light fixture 10 and the surface 130 . The airflow pathway provides a thermal pathway for communicating heat from the lighting fixture 10 . The cap 90 is attached as discussed above.
In operation, the lighting fixture 10 defines thermal pathways through the cap 90 , the reflector 70 , and the housing 12 , for communicating heat from the lighting fixture to ambient air. These pathways provide an air pathway chimney effect for transferring heat from the fixture 10 to ambient air. Air enters the lighting fixture 10 through the slot-like openings 98 in the cap 90 . The air travels through the openings 76 in the reflector 70 . With the light bulb 60 illuminated, the air becomes heated as it travels past the reflector 70 . The heated air exits the housing 12 through the openings 32 in the bottom 30 . For recess mounting, the heat communicates into the space above the mounting surface 134 . For surface mounting, the heat communicates outwardly of the housing along the surface 130 through the gaps or pathways defined by the pins 114 . In an alternate embodiment, the heated air communicates through holes in the side wall of the housing 12 and the can 100 .
The present invention accordingly provides an improved puck lighting system for surface and recessed mounting that is installed with a cap that easily connects to the reflector and base and that facilitates flow of heat away from the base through the vents to the ambient air. Accordingly, the present invention provides puck lighting fixtures particularly suited for under-cabinet installations. The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. The invention is not to be construed as limited to the particular forms disclosed as these are regarded as illustrative rather than restrictive. Moreover, variations and changes may be made by those skilled in the are without departing from the spirit of the invention described in the following claims. | A lighting fixture having a housing with a base and an opposing openable end, and a flange spaced-apart from an edge at the openable end that extends radially from an exterior surface of the housing. A reflector defines a dished cavity and seats on the edge of the housing, thereby defining a recess between an edge portion of the reflector and the flange. A light source is received within the housing. A light transmissive cover received on the housing has a tab received in the recess for guiding the rotation of the cover thereon. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of PCT International Application No. PCT/EP2014/058706, filed Apr. 29, 2014, which claims priority under 35 U.S.C. §119 from German Patent Application No. 10 2013 007 849.0, filed May 8, 2013, the entire disclosures of which are herein expressly incorporated by reference.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The invention relates to a pump arrangement, in particular magnetic clutch pump arrangement. The pump arrangement has an interior space formed by a pump casing a containment can which hermetically seals off a chamber surrounded by said containment can with respect to the interior space formed by the pump casing, an impeller shaft which can be driven in rotation about an axis of rotation, an impeller which is arranged on one end of the impeller shaft, an inner rotor arranged on the other end of the impeller shaft, an auxiliary impeller arranged in the chamber, and an outer rotor which interacts with the inner rotor.
[0003] German patent document no. DE 27 54 840 A1 has disclosed a magnetic clutch pump arrangement of said type with an auxiliary impeller. The auxiliary impeller is of disk-shaped construction and is equipped with radial bores. However, said embodiment, with regard to its efficiency, constitutes an inefficient impeller or delivery variant, and lowers the overall efficiency of the pump arrangement. Furthermore, a not inconsiderable level of outlay is required to produce the auxiliary impeller.
[0004] It is the object of the invention to provide a magnetic clutch pump arrangement with a forced-lubrication flow drive which is simple to produce and which exhibits improved efficiency.
[0005] The object of the invention is achieved in that the auxiliary impeller is fastened to the inner rotor.
[0006] Since the auxiliary impeller is fastened by way of its open side to that face side of the inner rotor which faces toward the base of the containment can, it is possible for the advantages of a closed channel-type impeller to be utilized by way of an open impeller, which is much easier to produce. Furthermore, the impeller does not have a hub and is easy to assemble and disassemble.
[0007] In one refinement, the containment can has a main body with an open side and with a side which is situated opposite the open side and which is closed by way of a domed base, and the auxiliary impeller has a rear shroud, whose outer surface facing toward the base of the containment can has a domed form.
[0008] By virtue of the fact that the domed form of the outer surface of the rear shroud substantially corresponds to the domed form of the base of the containment can, the dead space that is normally spanned by the domed base of the containment can is filled, whereby no additional axial structural space required by the magnetic clutch is taken up. Furthermore, the pressure resistance of the containment can is not unnecessarily reduced.
[0009] To improve the flow guidance of the medium as it enters a fluid inlet region of the auxiliary impeller, a paraboloid-like elevation is ideally provided in the center of the rear shroud.
[0010] In a further refinement, it is provided that, on the rear shroud, at a radial distance from the elevation, there are formed multiple raised portions which form vanes and corresponding impeller channels of the auxiliary impeller.
[0011] In a further refinement, it is proposed that the impeller channels have a channel base which is similar in form to a rampant three-center arch. This leads to an improvement in flow guidance.
[0012] In a further refinement of the invention, it is provided that the upper side of the vanes opposite the rear shroud, has a step close to the channel inlet edge. The step serves as an abutment shoulder and centering device for precise alignment of the auxiliary impeller fastened to the inner rotor.
[0013] For simple and inexpensive production, the impeller shaft and the inner rotor form a cover shroud, situated opposite the rear shroud, of the auxiliary impeller.
[0014] In a further advantageous refinement, in the raised portions which form the vanes, there are formed further impeller channels which extend in a radial direction from the outer lateral surface as far as a point close to the step.
[0015] To improve the flow guidance of the medium, the further impeller channels have a channel base which, at least in part, has a domed form which corresponds substantially to the domed form of the outer surface of the rear shroud.
[0016] According to the invention, the impeller shaft has an axial channel which is connected to the fluid inlet region of the auxiliary impeller.
[0017] In the context of the invention, it is proposed that, in a further embodiment, in the inner rotor, there are provided fluid channels which issue into the further impeller channels of the auxiliary impeller.
[0018] Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows the longitudinal section through a magnetic clutch pump arrangement having an auxiliary impeller according to an embodiment of the invention,
[0020] FIG. 2 shows the longitudinal section through the magnetic clutch pump arrangement as per FIG. 1 in a plane rotated through 90° in relation to FIG. 1 ,
[0021] FIG. 3 shows an auxiliary impeller, corresponding to FIG. 1 , in an enlarged illustration,
[0022] FIG. 4 is a detailed three-dimensional illustration of the auxiliary impeller as per FIG. 3 ,
[0023] FIG. 5 is a detailed three-dimensional illustration of a further embodiment of the auxiliary impeller according to the invention,
[0024] FIG. 6 shows a longitudinal section through a magnetic clutch pump arrangement having an auxiliary impeller according to the invention as per FIG. 5 ,
[0025] FIG. 7 shows the longitudinal section through a magnetic clutch pump arrangement as per FIG. 6 , with an inner rotor rotated through 45° in relation to FIG. 6 , and
[0026] FIG. 8 shows the longitudinal section through the magnetic clutch pump arrangement as per FIG. 6 , in a plane rotated through 90° in relation to FIG. 6 .
DETAILED DESCRIPTION
[0027] FIGS. 1 and 2 show a pump arrangement 1 in the form of a magnetic clutch pump arrangement. The pump arrangement 1 has a multi-part pump casing 2 of a centrifugal pump, which pump casing comprises a hydraulic casing 3 in the form of a spiral casing, a casing cover 4 , a bearing carrier cage 5 , a bearing carrier 6 and a bearing cover 7 .
[0028] The hydraulic casing 3 has an inlet opening 8 for the intake of a delivery medium and has an outlet opening 9 for the discharge of the delivery medium. The casing cover 4 is arranged on that side of the hydraulic casing 3 which is situated opposite the inlet opening 8 . The bearing carrier cage 5 is fastened to that side of the casing cover 4 which is opposite from the hydraulic casing 3 . The bearing carrier 6 is mounted on that side of the bearing carrier cage 5 which is situated opposite the casing cover 4 . The bearing cover 7 in turn is fastened to that side of the bearing carrier 6 which is opposite from the bearing carrier cage 5 .
[0029] A containment can 10 is fastened to that side of the casing cover 4 which is opposite from the hydraulic casing 3 , and said containment can extends at least partially through an interior space 11 delimited by the pump casing 2 , in particular by the casing cover 4 , by the bearing carrier cage 5 and by the bearing carrier 6 . The containment can 10 hermetically seals off a chamber 12 , which is enclosed by said containment can and by the casing cover 4 , with respect to the interior space 11 .
[0030] An impeller shaft 13 which is rotatable about an axis of rotation A extends from a flow chamber 14 , which is delimited by the hydraulic casing 3 and by the casing cover 4 , into the chamber 12 through an opening 15 provided in the casing cover 4 .
[0031] An impeller 16 is fastened to a shaft end, situated within the flow chamber 14 , of the impeller shaft 13 , and an inner rotor 17 arranged within the chamber 12 is arranged on the opposite shaft end, which has two shaft sections 13 a, 13 b with increasing diameters in each case. The inner rotor 17 is equipped with multiple magnets 18 which are arranged on that side of the inner rotor 17 which faces toward the containment can 10 . An auxiliary impeller 20 is fastened to the inner rotor 17 by way of screws 19 or other suitable fastening means.
[0032] Between the impeller 16 and the inner rotor 17 there is arranged a bearing arrangement 21 which is operatively connected to the impeller shaft 13 , which can be driven in rotation about the axis of rotation A.
[0033] A drive motor, preferably an electric motor, which is not illustrated drives a drive shaft 22 . The drive shaft 22 , which can be driven about the axis of rotation A, is arranged substantially coaxially with respect to the impeller shaft 13 . The drive shaft 22 extends through the bearing cover 7 , through the bearing carrier 6 , and at least partially into the bearing carrier cage 5 . The drive shaft 22 is mounted in two ball bearings 23 , 24 which are accommodated in the bearing carrier 6 . On the free end of the drive shaft 22 there is arranged an outer rotor 26 , which bears multiple magnets 25 . The magnets 25 are arranged on that side of the outer rotor 26 which faces toward the containment can 10 . The outer rotor 26 extends at least partially over the containment can 10 and interacts with the inner rotor 17 such that the rotating outer rotor 26 , by way of magnetic forces, sets the inner rotor 17 and thus likewise the impeller shaft 13 and the impeller 16 in rotation.
[0034] The containment can 10 , illustrated on an enlarged scale in FIG. 3 , has a substantially cylindrical main body 27 . The main body 27 is open on the side facing toward the casing cover 4 , and is closed by way of a domed base 28 on the side situated opposite the open side. On the open side, there is arranged a ring-like attachment flange 29 which is formed integrally with the main body 27 or which is fastened to the latter by welding or other suitable fastening means or devices, for example screws, rivets or the like. The attachment flange 29 has multiple bores 30 which extend parallel to the axis of rotation A and through which screws 31 can be passed and screwed into corresponding threaded bores in the casing cover 4 . The base 28 of the containment can 10 is formed by a substantially spherical segment-shaped spherical cap region 32 and an outer rim region 33 which forms the transition region between main body 27 and spherical cap region 32 .
[0035] As can be seen from FIGS. 3 and 4 , the auxiliary impeller 20 has a rear shroud 34 , whose outer surface, facing toward the base 28 of the containment can 10 , has a domed form. The domed form of the outer surface of the rear shroud 34 substantially corresponds to the domed form of the base 28 of the containment can 10 . In the center of the rear shroud 34 , a paraboloid-like elevation 35 is provided in a fluid inlet region 36 . Furthermore, multiple raised portions are formed on the rear shroud 34 at a radial distance from the elevation 35 , which raised portions form vanes 37 with a channel inlet edge 38 , facing toward the elevation 35 , and corresponding impeller channels 39 of the auxiliary impeller 20 . The elevation 35 is conducive to improving the flow guidance of the medium as it enters the impeller channels 39 of the auxiliary impeller 20 . In the exemplary embodiment shown, the vanes 37 extend in curved fashion from the fluid inlet region 36 to an outer lateral surface 40 of the auxiliary impeller 20 . The impeller channels 39 have a channel base 41 , which in turn has a domed form substantially corresponding to the domed form of the outer surface of the rear shroud 34 . The channel base 41 of the impeller channels 39 is, in the longitudinal section shown, similar in form to a rampant three-center arch, as illustrated in FIG. 6 . The impeller channels 39 have a first width W 1 at the fluid inlet region 36 and have a second width W 2 at the outer lateral surface 40 , wherein the second width W 2 is greater than the first width W 1 or at least corresponds to the first width W 1 .
[0036] The upper side of the vanes 37 has a step 42 close to the channel inlet edge 38 , which step serves as an abutment shoulder and centering device for the auxiliary impeller 20 fastened to the inner rotor 17 . A cover shroud which is situated opposite the rear shroud 34 and which closes off the impeller channels 39 formed between the vanes 37 can be dispensed with, as the impeller shaft 13 and the inner rotor 17 form the cover shroud of the auxiliary impeller 20 . Owing to its semi-open construction, the auxiliary impeller 20 is easy to produce both by casting, as it is easily demoldable, and by mechanical machining, as the impeller channels can be easily milled out.
[0037] At a distance radially outward from the steps 42 , installation holes 43 are provided which extend through the rear shroud 34 and the vanes 37 , through which installation holes the screws 19 are passed and screwed into the threaded bores 44 formed on that side of the inner rotor 17 which faces toward the base 28 of the containment can 10 . The auxiliary impeller 20 can thus be fastened by way of its open side to that face side of the inner rotor 17 which faces toward the base 28 of the containment can 10 . On the side situated opposite the channel inlet edge 38 , each vane 37 preferably has at least one recess 45 . An additional pressure increase is generated in this way.
[0038] As shown in FIG. 2 , in the casing cover 4 , there are provided at least one passage opening 46 and, in a bearing ring carrier 47 which fixes the bearing arrangement 21 , at least one radial passage opening 48 . The passage opening 48 extends through a flange-like region 49 by which the bearing ring carrier 47 , which is positioned coaxially with respect to the axis of rotation A and which extends into the chamber 12 , is fastened to the casing cover 4 by way of a screw connection (not illustrated). The passage openings 46 and 48 connect the flow chamber 14 to an inner region 50 of the bearing ring carrier 47 .
[0039] Thus, for the cooling and lubrication of the bearing arrangement 21 , delivery medium can be extracted from the flow chamber 14 and supplied by the passage openings 46 and 48 to the bearing arrangement 21 . Via at least one radial bore 51 , the delivery medium is delivered from the inner region 50 into an axial channel 52 , which extends from a region of the impeller shaft 13 surrounded by the bearing arrangement 21 to that end of the impeller shaft 13 which is situated within the chamber 12 , and thus to the auxiliary impeller 20 . The axial channel 52 is thus connected to the fluid inlet region 36 of the auxiliary impeller 20 . If necessary, at least one further radial bore 53 is formed which is likewise connected to the axial channel 52 formed in the impeller shaft 13 . The auxiliary impeller 20 delivers the medium used for cooling and lubrication radially outward into the chamber 12 , from where said medium is delivered back into the flow chamber 14 via multiple axial passage openings 54 formed in the flange-like region 49 and passage openings 55 formed in the casing cover 4 , said passage openings being shown in FIG. 1 .
[0040] FIGS. 5 to 8 show a further exemplary embodiment of the invention. The auxiliary impeller 20 , illustrated in detail in FIG. 5 , has vanes 37 which are formed by raised portions on the rear shroud 34 and which define impeller channels 39 which extend radially outward from the fluid inlet region 36 . In the exemplary embodiment shown, the vanes 37 extend rectilinearly from the fluid inlet region 36 to the outer lateral surface 40 of the auxiliary impeller 20 . The impeller channels 39 have a first width W 1 at the fluid inlet region 36 and a second width W 2 at the outer lateral surface 40 , wherein the second width W 2 is greater than the first width W 1 or at least corresponds to the first width W 1 .
[0041] Further impeller channels 56 are formed in the raised portions which form the vanes 37 , which further impeller channels extend in the radial direction likewise in substantially straight form, that is to say without a curvature or without a significant curvature, from the outer lateral surface 40 to a point close to the step 42 , and which further impeller channels have a channel base 57 which, at least in part, has a domed form which substantially corresponds to the domed form of the outer surface of the rear shroud 34 . As viewed in longitudinal section, the channel base 57 of the impeller channels 56 is similar in form to a rampant three-center arch, as illustrated in FIG. 7 . The impeller channels 56 widen toward the outer lateral surface 40 proceeding from the region adjacent to the step 42 , and said impeller channels have a first width W 3 at a fluid inlet region 56 a and a second width W 4 at the outer lateral surface 40 , wherein the second width W 4 is greater than the first width W 3 or at least corresponds to the first width W 3 .
[0042] FIGS. 6 to 8 show a pump arrangement 1 which is equipped with an auxiliary impeller 20 as illustrated in FIG. 5 . Here, the view in FIGS. 6 and 7 corresponds to the view in FIG. 1 . The view in FIG. 8 corresponds to the view in FIG. 2 . As can be seen from FIG. 6 , the at least one radial bore 53 leads into an axial channel 52 which is shorter than in FIGS. 1 and 2 . Furthermore, the bearing ring carrier 47 has fluid channels 58 running parallel to the axis of rotation A, which fluid channels connect the inner region 50 of the bearing ring carrier 47 to the chamber 12 which is enclosed by the containment can 10 and by the casing cover 4 .
[0043] FIG. 7 shows the pump arrangement 1 shown in FIG. 6 with an inner rotor 17 rotated through 45° about the axis of rotation A. In the inner rotor 17 there are provided fluid channels 59 which are arranged approximately at the same radial distance from the axis of rotation A as the fluid channels 58 of the bearing ring carrier 47 , and which are thus substantially in alignment with said fluid channels 58 at least in the position illustrated. The fluid channels 59 issue into the impeller channels 56 of the auxiliary impeller 20 , which is arranged on that face side of the inner rotor 17 which faces toward the base 28 of the containment can 10 .
[0044] For the cooling and lubrication of the bearing arrangement 21 , delivery medium is extracted from the flow chamber 14 and, as shown in FIG. 8 , is supplied to the bearing arrangement 21 via the at least one passage opening 46 in the housing cover 4 and via the at least one passage opening 48 in the flange-like region 49 of the bearing ring carrier 47 . Via the at least one radial bore 53 , the delivery medium is delivered from the inner region 50 of the bearing ring carrier 47 into the axial channel 52 and to the auxiliary impeller 20 . By way of the impeller channels 39 , the auxiliary impeller 20 delivers the medium used for cooling and lubrication radially outward into the chamber 12 .
[0045] At the same time, as per FIG. 7 , the delivery medium extracted from the flow chamber 14 is delivered from the inner region 50 of the bearing ring carrier 47 , via the fluid channels 59 formed in the inner rotor 17 , into the impeller channels 56 of the auxiliary impeller 20 , and radially outward into the chamber 12 .
[0046] From the chamber 12 , the medium is delivered back into the flow chamber 14 via the at least one passage opening 55 (shown in FIGS. 6 and 7 ) formed in the casing cover 4 .
[0047] In the exemplary embodiments shown, the auxiliary impeller 20 is shown either with the impeller channels 39 or with the impeller channels 39 and the impeller channels 56 . It is self-evident that the auxiliary impeller 20 may also be equipped only with the impeller channels 56 .
[0048] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
LIST OF REFERENCE DESIGNATIONS
[0000]
1 Pump arrangement
2 Pump casing
3 Hydraulic casing
4 Casing cover
5 Bearing carrier cage
6 Bearing carrier
7 Bearing cover
8 Inlet opening
9 Outlet opening
10 Containment can
11 Interior space
12 Chamber
13 Impeller shaft
13 a Shaft section
13 b Shaft section
14 Flow chamber
15 Opening
16 Impeller
17 Inner rotor
18 Magnet
19 Screw
20 Auxiliary impeller
21 Bearing arrangement
22 Drive shaft
23 Ball bearing
24 Ball bearing
25 Magnet
26 Outer rotor
27 Main body
28 Base
29 Attachment flange
30 Bore
31 Screw
32 Spherical cap region
33 Rim region
34 Rear shroud
35 Elevation
36 Fluid inlet region
37 Vane
38 Channel inlet edge
39 Impeller channel
40 Outer lateral surface
41 Channel base
42 Step
43 Installation hole
44 Threaded bore
45 Recess
46 Passage opening
47 Bearing ring carrier
48 Passage opening
49 Flange-like region
50 Inner region
51 Radial bore
52 Axial channel
53 Radial bore
54 Passage opening
55 Passage opening
56 Impeller channel
57 Channel base
58 Fluid channel
59 Fluid channel
A Axis of rotation | A pump arrangement, in particular a magnetic clutch pump arrangement, is provided. The pump arrangement includes a pump housing containing an impeller shaft, a containment shell which seals an enclosed chamber within the inner chamber of the pump housing, an impeller mounted on one end of the impeller shaft, an inner rotor mounted on the other end of the impeller shaft, an outer rotor which is mounted on the drive shaft and co-operates with the inner rotor, and an auxiliary impeller mounted in the chamber adjacent to a domed base of the containment can. The auxiliary impeller is secured to the inner rotor and includes vanes and impeller channels for circulation of media. | 5 |
This application claims priority from U.S. Application No. 60/946,631 filed Jun. 27, 2007.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to furniture for sitting or resting, and more particularly to seating for a transient population. Embodiments of the present invention allow for people to perform certain activities while waiting, including working on a computer, listening to music, or operating an electrical device.
2. Description of Related Art
There are many seating systems that support the various activities that people perform while waiting, such as reading, conversing, eating/drinking or just relaxing in a comfortable environment. Yet, such systems tend to lack capabilities that support more advanced activities such as working on laptops, listening to music, plugging into data sources and powering-up electronic devices. All of these activities could ideally be performed while waiting in an airport/transportation depot, hotel lobby, healthcare clinic, educational study facility or other space (indoors or outdoors) that is designated for waiting.
Unlike the present invention, other seating groups which incorporate electrical access run the electrical wiring under the seats or through a beam. For example, in U.S. Pat. No. 6,179,381, the electrical connection extends from the seat back through the arm and is dedicated to each sitter at the arm location. The plug for powering-up is dedicated to each seat for its use in classroom training. Further, in this prior invention, all the seats are facing in the same direction, as in a lecture hall. In U.S. Pat. No. 6,683,394, which covers a power and data distribution system for use in combination with a beam-mounted seating structure that includes a series of seat assemblies each mounted to a common support beam, the power and data distribution system includes a wire way that is mounted to the support beam and extends along the entire row of seats. The power and data distribution system is separate from the seating structure and can be attached and removed from the seating structure independent from the construction of the seating structure. U.S. Pat. No. 6,284,213 has a hollow beam housing electrical wiring which runs underneath the front of a row of passenger seats. In United Kingdom Patent Application No. GB 2395427, the electrical interface is in the armrest or the front face of the seating element.
In airplane seating, such as U.S. Pat. Nos. 5,984,415 and 7,036,889, the electronic devices located at the back of the seats are placed there for the benefit of the user in the seat rows behind. Unlike the present invention, the seats of the above mentioned patents are always arranged forward facing, as in an airplane. Further, in U.S. Pat. Nos. 5,984,415 and 7,036,889 an electrical or data connection is dedicated to each passenger unit through the arm of the seat.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to furniture systems that may be used in waiting areas, such as transportation waiting areas, hotel lobbies, hospitals and healthcare facilities, educational facilities, and other spaces (indoors or outdoors) that are designated for waiting. While many seating systems in waiting areas support only basic activities such as sitting, reading or eating/drinking, the invention described herein allows for the sitter to do much more, thereby enhancing a person's waiting experience. The central element that supports advanced activities in the present invention, such as working on laptops, listening to music, powering-up an electrical device, is an electrical wire way.
In a preferred embodiment of the present invention, the electrical wire way is behind the seat back in a single line of tandem seating and in between seat backs in a back to back seating configuration. The electrical wire way provides the sitter with access to electrical and data ports while he/she is waiting at the airport/transportation depot, hotel lobby, healthcare clinic, educational facility or other area (inside a building or outside) that is designated for waiting. In the case of the present invention's placement in an open environment, electrical grounding would be necessary. This unique electrical wire way facilitates powering-up and plugging in electronic devices and data either through electrical/data ports or battery charging through electrical coupling plates.
In one embodiment of the present invention, the sitter plugs into the electrical and data ports provided on the cover plate of the electrical wire way provided behind the seat frame. The sitter may drape the electrical wires next to his/her lap while using the laptop or other electronic device. If the computer user can not take a seat directly near a plug, the wire way cover can serve as a surface to run the wire until it reaches the sitter who is plugging into an electrical or data port. One can also place his/her computer or handset device on to the wire way cover where a battery coupling plate may be provided in order to charge the battery of the laptop computer or handset via battery coupling (as in an ecouple battery charger plate).
In an another embodiment of the present invention, the electrical wiring and data outlets are behind the sitter rather than at the arm of each seat, thereby making the installation of this invention less expensive and not dedicated to each sitter, as in the case of electrical ports in tandem seating, for instance, in a lecture hall or on an airplane. In the present invention, since the arm does not have an electrical interface for each seat, the arm is optional. In the case of the back to back seating configuration, by sharing the same wire way and plug access, the present invention saves material, electrical wiring and interfaces. Initial electrical installation is less expensive and retrofitting of the present invention's tandem seating design is easy and inexpensive because there is easy access to the wiring through the top cover plate. Electrical and data ports are not dedicated to each seat arm or seat side, as on the seat on a beam construction, for example in U.S. Pat. No. 6,683,394.
In a further embodiment of the present invention, the electrical and data ports are installed on the cover plate above the wire way which is behind the single line of tandem seats. The wire way and cover plate are also between the back to back tandem seating arrangement or configuration. In the back to back seating arrangement, the electrical wire way is common to seats facing away from one another thereby eliminating a separate electrical wire way and plug for these back to back row of seats. Back to back seating arrangements are typical in airports/transportation depots, healthcare facilities, and other indoor and outdoor spaces designated for waiting. Preferably, the electrical wire way has electrical wiring that can accommodate at least one (1) plug per ten (10) seating units or up to ten (10) plugs for ten (10) seating units, and can be easily accessed through the top cover plate and retrofitted for any number of electrical or data plugs/ports. For each electrical plug/port, it is suggested that there be an equal number of data plugs/ports. The data ports may include access to an internet cable. However, the seating system may also utilize a wireless internet source, such that the wireless hub is placed within the wire way, and users can access the internet merely by sitting in the seating system or standing within a close proximity.
In another embodiment of the present invention, the furniture system supports watching television. A TV monitor is installed in the backside of the electrical wire way such that people sitting on that particular configuration of seats or nearby seating systems can watch television while waiting. In addition to electrical wiring, cable wiring may run through the wire way thereby providing the sitter with numerous television channels to watch.
In an additional embodiment of the present invention, a table or many tables are incorporated into the furniture system so that the sitter can set a variety of objects on the table, including but not limited to food and/or drink.
In a still further embodiment of the present invention, the furniture system gives the sitter a comfortable reading environment. In this embodiment, a storage box can be included within the cover plate and inserted into the wire way. The storage box can be used as a receptacle for storing various periodicals, such as magazines and newspapers. In the alternative, the storage box can be used to house fake plants thereby improving the appearance of the waiting area. Generally speaking, the storage box can be used to hold a number of items that would improve the waiting experience. The electrical and data wires are aligned such that any storage box can easily fit into the wire way without disturbing the electrical and data sources. A cylindrical container can also be inserted within the cover plate and used alternatively or in conjunction with a storage box. An electrical or data port/plug can be placed on that portion of the cover plate that remains. In the alternative, for locations where liquids could spill, a power grommet, such as a Douglass Mocket PCS39/EEHW power grommet, may extend through an aperture in the cover plate. Additionally, one or more lights may be plugged into the electrical outlet in order to enhance the reading environment. The light may be plugged into the surface of the cover plate or alternatively below the cover plate should the specifier want the light to be a permanent fixture.
In another embodiment of the present invention, a power grommet, such as a Douglas Mockett PCS34, can be placed within the wire way such that the electrical source can be reached through an aperture in the cover plate. By enclosing the power source, this embodiment is preferred for places where liquids may be spilled.
In a further embodiment of the present invention, a table can be placed above the cover plate in a single line of tandem seats. Having a table of higher elevation than the cover plate provides a surface for persons to be able to work, read, relax and the like while standing. In particular, this surface will be able to provide an ideal surface for a person to use his/her computer while standing. This embodiment allows many persons to take advantage of the electrical and data plugs/ports, in addition to those sitting in the seats.
It is suggested that the furniture system be made of a sustainable material, such as molded plastic, formaldehyde-free medium density fiberboard (MDF) or certified wood, so that the furniture system can withstand significant use over a long duration of time while being environmentally friendly. A material, such as natural latex foam, is also a sustainable material and ideal upholstery for the seats. Other sustainable upholstery materials are flame retardant textiles, compostable stretch fabrics, chrome-free leathers, organic leathers, compostable felt, sustainable textiles, cellulose fabric, post-consumer recycled polyester, hemp and polymer-blended textiles. Useful examples of these upholstery materials include those marketed under the following trade names: Climatex® LifeguardFR™, Q Collection 2005 Climatex Collection®, Climatex® Lifecycle™Natural Stretch, Ecco-La leather, Sustana® leather, Felt Climatex® Lifecycle™, LIFE (Low Impact for the Environment) Textiles®, and Terratex™.
The tables are also preferably constructed of sustainable materials, such as the combination of phenolic resins and paper fiber, bamboo, reclaimed agricultural fiber, plantation-grown coconut palms, composite material of burled wood and sunflower seed husks, waste wood particleboard, high density polyethylene, non-toxic co-polyester resin, high pressure laminates made from recycled laminate scraps, formaldehyde-free medium density fiberboard (MDF), certified wood and laminate made with abaca. Useful examples of such materials include those sold under the PaperStone™, Plyboo®, Plyboo Strand®, Kirei Board, Durapalm®, Dakota Burl®, 100 Percent, Ecoresin™, Tefor®, ALLGREEN® MDF, Medite® II, Medex®, Medite® FR and Abacá™ brands. Other suggested materials for the tables are linoleum surface laminate, for example that sold under the eoLin® brand, hardwood plywood and linoleum-laminated wood sheets. Nevertheless, this invention covers any material the manufacturer and specifier of the product would find suitable for the furniture system, the upholstery and the tables.
In one embodiment of the invention, the seats of the seating system of the present invention may rest on a lower leg frame made of various materials, such as metal, plastic or wood. In other embodiments of invention, the seats may rest on a base or on the floor.
When the present invention is located in a public setting, the power and data sources provided to the user can be administered on a metered basis. For instance, there may be a receptacle for depositing cash or charging a credit/debit card so that the user can pay a certain amount of money for a certain unit of time during which he/she can access the power and data sources. Alternatively, a meter could be activated by a call to a specified number (preferably from a mobile phone). When the call is answered, the user can enter a code which specifies an account to be changed. The user could also specify which outlet is to be activated and optionally for how long.
In various embodiments of the present invention, the seats may be arranged in configurations including, but not limited to: 1) a single line or arc of tandem seats, 2) a back to back line or arc of tandem seats, 3) a single line or arc of tandem seats that are connected to another single line or arc of tandem seats creating an inside corner for the sitters, 4) a single line or arc of tandem seats that are connected to another line or arc of seats creating an outside corner for the sitters, 5) a back to back line or arc of tandem seats that are connected to another back to back line or arc of tandem seats creating an inside corner for the sitters, and 6) a back to back line or arc of tandem seats that are connected to another back to back or single line or arc of tandem seats creating an outside corner for the sitters.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale. For an initial overview of the invention, FIG. 3 provides a front view of one such embodiment.
FIG. 1 is an exploded view of a single seat frame according to one embodiment of the invention.
FIG. 1A is a back view of an exploded view of a single seat frame showing the path the electrical wiring takes through the seating system according to one embodiment of the invention.
FIG. 1B is an exploded view of a single seat frame showing the placement of an electrical floor box assembly relative to the floor according to one embodiment of the invention.
FIG. 1C is an exploded side view of a single seat frame showing the placement of an electrical floor box assembly relative to the floor according to one embodiment of the invention.
FIG. 1D is a closer view of the electrical floor box assembly of FIG. 1B relative to the floor according to one embodiment of the invention.
FIG. 2 is a top view of a single seat according to one embodiment of the invention, in particular a top view of the electrical wire way.
FIG. 3 is a front perspective of two single lines of tandem seats creating an inside corner for the sitters according to one preferred embodiment of the invention.
FIG. 3A is a rear bottom perspective of two single lines of tandems seats that are connected creating an inside corner which includes a table according to one preferred embodiment.
FIG. 3B is a rear bottom perspective of an inside corner created by two single lines of tandem seats showing the passage of the electrical wiring from one electrical wire way, along the edge of a table, and into a second electrical wire way, according to one embodiment of the invention.
FIG. 4 is a partially exploded view of a single row of tandem seats that are connected to a second row of tandem seats creating an outside corner for the sitters according to one preferred embodiment of the invention.
FIG. 4A is a rear bottom perspective of a single row of tandem seats that are connected to a second row of tandem seats creating an outside corner according one preferred embodiment of the invention.
FIG. 4B is an exploded view of the electrical wiring traversing the first and second single rows of tandem seats of FIG. 4A .
FIG. 5 is a partially exploded view of a back to back configuration of tandem seats according to one preferred embodiment of the invention.
FIG. 6 is a side view of a back to back configuration of tandem seats according to one preferred embodiment of the invention.
FIG. 7 is a front perspective of a back to back row of tandem seats with a monitor installed in the back of a seat frame according to one preferred embodiment of the invention.
FIG. 8 is a top view of two seating systems composed of back to back tandem seats in which the systems are connected at a staggered distance by a table according to one preferred embodiment of the invention.
FIG. 9 is a partially exploded front view of a single seat frame showing an inset storage box, as well as an electrical port, in particular a power grommet, extending though an aperture in the cover plate according to one preferred embodiment of the invention.
FIG. 10 is a partially exploded front view of a single seat frame showing an electrical port, in particular a power grommet, an inset storage box, and an inset cylindrical container which are accessible from the cover plate according to one preferred embodiment of the invention.
FIG. 11 is a front view of a single line of tandem seats with a table placed above the cover plate and optional routing for the electrical wiring.
FIG. 12 is a front view of a waiting area which includes several rows of back to back tandem seats with a monitor installed in the back of a seat frame, as well as fake plants placed within a storage box inside the wire way, according to one preferred embodiment of the invention.
FIG. 13 is a front view of a waiting area which includes several seating systems composed of back to back tandem seats in which the systems are connected at staggered distances by a table, and fake plants are placed within a storage box inserted into the cover plate and inside the wire way, yet leaving electrical/data ports accessible, according to one preferred embodiment of the invention.
FIG. 13A is a front view of the staggered seating system illustrated in FIG. 13 showing the connection of the back to back seating systems by a table according to one preferred embodiment of the invention.
FIG. 14 is a front view of a waiting area which includes several rows of back to back tandem seats connected to form both inside and outside corners, with banquet seats at the terminal ends of the seating system, according to one preferred embodiment of the invention. Fake plants are placed within cylindrical containers inserted into the cover plate and positioned inside the wire way, while electrical/data ports remain accessible.
FIG. 15 is a front view of a waiting area which includes several rows of back to back tandem seats connected by tables, either in a single line or forming a corner, according to one embodiment of the invention. Fake plants are placed within cylindrical containers inserted into the cover plate and positioned inside the wire way, while electrical/data ports remain accessible.
FIG. 16 is a front view of a single line of tandem seats showing a table with affixed storage box connected to one end of the seating system, as well as a storage box containing plants which is inserted into the cover plate and sits within the wire way according to one preferred embodiment of the invention.
FIG. 17 is a front view of a waiting area which includes at least 4 single rows of tandem seats that are connected to form outside corners, thereby forming a parallelogram arrangement, according to one preferred embodiment of the invention.
FIG. 18 is a front view of a row of back to back tandem seats forming an arc according to one embodiment of the invention.
FIG. 18A is a top view of a row of back to back tandem seats forming an arc according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
FIG. 1 is an isometric exploded view of a single seat frame with an electrical wire way 1 for the single line seating arrangement.
The embodiment illustrated in FIG. 1 includes a seat 10 , which is connected to and abuts the electrical wire way. The seat 10 and electrical wire way are connected to a lower seat frame 5 . An electrical floor box assembly 15 is connected to the lower seat frame 5 at a leg and provides the initial electrical source, such that the electrical wiring 6 traverses through a leg of the lower seat frame 5 and enters the electrical wire way at the top of the leg. Ideally, the electrical floor box assembly 15 is below floor level, such that the top of the box is flush with the floor, so as to prevent tripping on the box.
A cover plate 3 extends over the top portion of the wire way. Cover plate 3 can be hinged or cleated, and it is suggested that there be a locking mechanism. Electrical/data port 4 extends through an aperture in the cover plate 3 and is connected to the electrical wiring 6 within the wire way. This illustration is only a suggestion for the placement and type of the electrical/data port 4 . The arrangement and number of outlets would be determined by the specifier.
An optional lounge arm frame 8 may be connected to either the left, right or both sides of the seat 10 .
FIG. 1A is a back view of an exploded view of a single seat frame showing the path the electrical wiring 6 takes through the seating system according to one embodiment of the invention. Beginning at an electrical floor box assembly 15 , the electrical wiring 6 traverses through the leg of lower seat frame 5 , exits the seat frame at the top of a leg, enters the seat frame with an electrical wire way 1 through an aperture at the bottom of the wire way and proceeds through the wire way with a portion of the wiring terminating at the cover plate.
FIG. 1B is an exploded view of a single seat frame showing the placement of an electrical floor box assembly relative to the floor according to one embodiment of the invention. In this preferred embodiment, the electrical floor box assembly 15 is below floor level, such that the top of the box is flush with the floor, so as to prevent tripping on the box. As noted in FIG. 1 , the electrical floor box assembly 15 is connected to the lower seat frame 5 at a leg and provides the initial electrical source, such that the electrical wiring 6 traverses through a leg of the lower seat frame 5 , enters the electrical wire way at the top of the leg, and a portion of the electrical wiring 6 terminates in an electrical port 4 .
FIG. 1C is an exploded side view of a single seat frame with electrical wire way 1 showing the connection of the electrical floor box assembly 15 to the lower leg frame 5 , wherein the box is below the floor.
FIG. 1D is a closer view FIG. 1B , showing the placement of the electrical floor box assembly 15 relative to the floor.
FIG. 2 is an isometric view of a single seat unit with a cover plate 3 open for access to the electrical wiring 6 . It is preferred that the cover plate be hinged or cleated to the wire way. It is further preferred that the cover plate have a locking mechanism. The electrical wiring 6 passes through the wire way and a portion of the electrical wiring ends in an electrical port 4 , while the remainder of the electrical wiring continues through the wire way. In this particular embodiment of the invention, the electrical port 4 extends through an aperture in the cover plate and is thus accessible from the surface of the cover plate 3 when the cover plate 3 is closed. However, how the electrical ports 4 are installed, whether onto or under the top plate, will be specified by the user, depending on an indoor or outdoor installation of the seating system. Furthermore, the type of electrical port will be specified by the user. One preferred embodiment uses a power grommet, such as a Douglas Mockett PCS39/EEHW power grommet, as the electrical port. Electrical outlets and installation desirably are child-safe for indoor or outdoor use and grounded for outdoor use.
FIG. 3 is an isometric partially exploded view of a single line of tandem seats with an electrical wire way 1 connected to a second single line of tandem seats with an electrical wire way 1 , and a corner table 9 spanning the inside of the corner. In the first and second single line of tandem seats, seats 10 abut the electrical wire way and both the seats and wire way are placed on top of and connected to lower seat frame 5 . A cover plate 3 extends over the wire way, and at least one electrical/data port 4 is accessible from the cover plate. In one preferred embodiment an electrical charging plate can plugged into an electrical port 4 and positioned on the cover plate.
The first and second single lines of tandem seats are connected to form an inside corner. On the inside corner seating arrangement two persons on either side of the corner table would be sitting facing toward one another. Each single line of tandem seats has a lounge arm frame 8 connected to the seats 10 forming the inside corner. The lounge arm frames 8 of the first and second single line of tandem seats are fixed together at the inside corner. A corner table 9 spans between and is connected to the lounge arms frames 8 of both the first and second single lines of tandem seats. The corner table can take any shape spanning between the seat units.
In the particular embodiment of FIG. 3 , the electrical wiring 6 extends through a rear leg of the lower seat frame 5 of one of the single lines of tandem seats and into wire way. The same electrical wiring 6 extends through both the first and second single line of tandem seats by traversing through the lounge arm frames 8 , as more fully shown in FIG. 3A .
FIG. 3A is a partially exploded rear bottom view of two seats that are connected to create an inside corner, as shown in FIG. 3 . The electrical wiring 6 exits the wire way of the first single line of tandem seats, travels through the rear end of the lounge arm frame 8 to the front of the arm where it exits through an aperture in the arm and enters an aperture at the front of the lounge arm frame 8 connected to the second single line of tandem seats. The electrical wiring 6 traverses a similar path in the second single line of tandem seats as it did in the first single line of tandem seats.
FIG. 3B is a rear bottom perspective of an inside corner created by two single lines of tandem seats wherein the corner table 9 is connected to the seats of the seating system, rather than lounge arms as shown in FIGS. 3 and 3A . In this preferred embodiment, the electrical wiring 6 traverses the single line of seats with an electrical wire way 1 , exits the wire way through an aperture in the rear, traverses along the edge of the corner table 9 , and enters a second line of single seats with an electrical wire way 1 through an aperture in the rear of the second wire way.
FIG. 4 is a partially exploded isometric view of a single line of tandem seats with an electrical wire way 1 connected to a second single line of tandem seats with an electrical wire way 1 having a corner table 9 spanning the outside corner. In the first and second single line of tandem seats, seats 10 abut the wire way and both the seats and wire way are placed on top of and connected to lower seat frame 5 . A cover plate 3 extends over the wire way 1 , and at least one electrical/data port 4 is accessible from the cover plate for each seat.
The first and second single lines of tandem seats are connected to form an outside corner. On the outside corner seating arrangement two persons on either side of the corner table would be sitting facing away from one another. In this preferred embodiment, an arm frame 7 may be placed at either the terminal ends of the seat rows or to the left, right or both sides of an individual seat 10 . Arm frame 7 does not cover the wire way. The first and second single lines of tandem seats are fixed together at the outside corner where the wire ways of each line of seats meet. A corner table 9 spans the outside corner, connected to seats 10 of both the first and second single lines of tandem seats. A triangular shaped corner table 9 is shown. The triangular shaped shape is only suggested; the corner table can take any shape spanning between the seat units.
In this preferred embodiment, an electrical floor box assembly 15 is connected to the lower seat frame 5 at a leg and provides the initial electrical source, such that the electrical wiring 6 traverses through the leg of the lower seat frame 5 and enters the electrical wire way at the top of the leg. The same electrical wiring extends through both the first and second single lines of tandem sheets, as more fully shown in FIGS. 4A and 4B .
FIG. 4A is a partially exploded rear view of the first and second single lines of tandem seats illustrated and described in FIG. 4 showing the electrical wiring traversing from the first single line of tandem seats into the second line of tandem seats.
FIG. 4B is a closer view of the electrical wiring 6 traversing the first and second single lines of tandem seats. The electrical wiring 6 exits the wire way of the first single line of tandem seats through an aperture at the bottom of the wire way and enters into the second wire way through an aperture at the bottom of the second wire way of the second line of tandem seats.
FIG. 5 is a partially exploded isometric view of a back to back seating arrangement which includes a seat frame without an electrical wire way 2 . The electrical wiring 6 only extends through a first seating arrangement with an electrical wire way 1 . For the first seating arrangement with an electrical wire way 1 , seats 10 abut the wire way and both the seats and wire way are placed on top of and connected to lower seat frame 5 . In the second seating arrangement without an electrical wire way 2 , the seats 10 are also placed on top of and connected to lower seat frame 5 , such that the second seating arrangement abuts wire way of the first seating arrangement. A cover plate 3 extends over the wire way, and at least one electrical/data port 4 is accessible from the cover plate for each seat. In this preferred embodiment, persons sitting in either the first or second arrangement of the back to back seats have access to the electrical/data ports 4 .
An electrical floor box assembly 15 is connected to the lower seat frame 5 at a leg and provides the initial electrical source, such that the electrical wiring 6 traverses through the leg of the lower seat frame 5 and enters the electrical wire way at the top of the leg.
This seating arrangement can be in a straight line or an arc of seating units. The back to back arrangement might include an inside or outside corner table that would be attached and situated similarly to FIGS. 3 and 4 . The seating system may have a lounge arm frame 8 at the terminal ends of the seat rows.
FIG. 6 is an isometric side view of the back to back seating arrangement more fully described in FIG. 5 .
FIG. 7 is a partially exploded view of a back to back seating arrangement which includes seat frames with an electrical wire way 1 and seat frames without an electrical wire way 2 , as illustrated and described more fully in FIG. 5 ; however, the preferred embodiment of FIG. 7 includes a TV monitor 11 installed in the back of a single line seat frame which has an electrical wire way 1 . This embodiment may include an arm frame 7 .
FIG. 8 is a partially exploded isometric view of a back to back seating arrangement which includes seat frames with an electrical wire way 1 and seat frames without an electrical wire way 2 . The back to back seating arrangement is more fully described with respect to FIG. 5 .
This seating arrangement could be in a straight line or an arc of seating units. The back to back arrangement might include a table 13 that spans between and is connected to the lounge arm frames 8 of the back to back seating units. In this particular embodiment, two systems of the back to back seating arrangements are connected via a table 13 at staggered distances above and below an axis.
In one preferred embodiment, table 13 contains a storage box 16 and cylindrical containers 17 for storing various items such as storing periodicals or writing utensils, respectively.
An electrical floor box assembly 15 is connected to the lower seat frame 5 at a leg and provides the initial electrical source, such that the electrical wiring 6 traverses through the a leg of the lower seat frame 5 and enters the electrical wire way at the top of the leg. A portion of the electrical wiring 6 terminates at an electrical port 4 which is accessible from the cover plate 3 .
FIG. 9 is a partially exploded front view of a single seat frame showing an inset storage box 16 . The storage box 16 , which may be used for holding periodicals or fake plants or other items to support the task of waiting, is inserted into the cover plate and fits conveniently into the wire way without disturbing any wires. An electrical port 4 , in this embodiment a power grommet, is connected to the electrical wiring 6 and extends through an aperture in the cover plate. One preferred embodiment includes a Douglas Mockett PCS39/EEHW power grommet. Given that the power grommet encloses the electrical power source, the grommet is ideal for places where liquids could spill.
FIG. 10 is a partially exploded front view of a single seat frame showing an inset storage box 16 , an electrical port 4 , and a cylindrical container 17 which is inserted into the cover plate and fits conveniently into the wire way without disturbing any wires. Cylindrical container 17 may be used for holding smaller items, such as writing utensils or fake plants.
FIG. 11 is a front view of a single line of tandem seats with an electrical wire way 1 and a table 18 connected to the surface of the cover plate 3 . In this embodiment, the electrical/data ports 4 and any chargers positioned on the cover plate remain accessible to the user who is sitting or the user who is standing at the table. The table can be used for any waiting past-time; however, it is suggested to function as a flat and stable surface for computers or writing.
In this particular embodiment, the electrical wiring 6 enters the wire way through optional routing 14 . In the event it is not possible or not ideal to have the electrical wiring 6 extend through a leg or base of the seating system, the optional routing 14 allows the seating system to gain access to an electrical floor box assembly 15 no matter where the electrical source is located. In such an embodiment, the electrical wiring 6 extends from the electrical floor box assembly 15 , through the optional routing 14 , and may enter the wire way at any location.
FIG. 12 is a front view of a waiting area which includes several rows of back to back tandem seats with a TV monitor 11 installed in the back of a single line seat frame with an electrical wire way 1 . A table 13 extends beneath the monitor and sits on lower seat frame 5 . In this particular embodiment, arm frames 7 separate individual seats 10 . Storage boxes 16 are inserted through the cover plate 3 and positioned within the wire way. Here, the storage boxes support fake plants. Electrical/data ports 4 are still accessible to the user from the portion of the cover plate 3 that surrounds the storage box 16 .
FIG. 13 is a front view of a waiting area which includes several seating systems composed of back to back tandem seats, which includes seat frames with an electrical wire way 1 and seat frames without an electrical wire way 2 . Lounge arm frames 8 are connected to the terminal ends of each row of back to back tandem seats. In this particular embodiment, the rows of back to back seats are connected by tables 13 , which span between and are connected to the lounge arm frames 8 of the back to back seating units, at staggered distances above and below an axis. Storage boxes 16 are inserted through the cover plate 3 and positioned within the wire way. Here, the storage boxes support fake plants. Electrical/data ports 4 are still accessible to the user from the portion of the cover plate 3 that surrounds the storage box 16 .
FIG. 13A is a close-up view of the seating system described more fully in FIG. 13 showing the connection of the table 13 between the lounge arm frames 8 of each back to back seating arrangement.
FIG. 14 is a front view of a waiting area which includes several rows of back to back tandem seats connected to form both inside and outside corners, according to one preferred embodiment of the invention. Corner tables 9 span the outside orders. For the single line of tandem seats with an electrical wire way 1 , cylindrical containers 17 are inserted into the cover plate without disturbing the electrical wiring in the wire way. Electrical/data plugs 4 are still accessible to the user from the portion of the cover plate that surrounds cylindrical containers 17 . In this particular embodiment, the cylindrical containers support fake plants. At the most terminal ends of the seating system, banquet seats 19 connect to and span the distance between the back to back seats. Further, arm frames 7 may be randomly placed between each individual seat 10 .
FIG. 15 is a front view of a waiting area which includes several rows of back to back tandem seats connected by a table 13 and configured in a single line and forming an inside corner, according to one embodiment of the invention. The table 13 connects the rows of tandem seats by being affixed to lounge arm frames 8 . For the single line of tandem seats with an electrical wire way 1 , cylindrical containers 17 are inserted into the cover plate without disturbing the electrical wiring in the wire way. Electrical/data ports 4 are still accessible to the user from the portion of the cover plate that surrounds cylindrical containers 17 . In this particular embodiment, the cylindrical containers support fake plants.
FIG. 16 is a front view of a single line of tandem seats with an electrical wire way having a table with affixed storage box 12 connected to a terminal end of the row of seats. The table with affixed storage box 12 can be used to store a number of items, including, for example, periodicals. In this preferred embodiment, storage boxes 16 are inserted into the cover plate 3 without disturbing the electrical wiring in the wire way. Electrical/data ports 4 are still accessible to the user from the portion of the cover plate 3 that surrounds the storage boxes 16 . In this particular embodiment, the storage boxes support fake plants.
FIG. 17 is a front view of a waiting area which includes several seating systems composed of at least 4 single rows of tandem seats with an electrical wire way 1 that are connected to form outside corners. The rows of tandem seats are configured to form a parallelogram arrangement. Lounge arms 8 are attached to the terminal end of each single row of tandem seats. Corner tables 9 are affixed to the lounge arms 8 and span the outside corners. Electrical/data ports 4 are accessible to the user from the surface of the cover plate 3 .
FIG. 18 is a front view of a row of back to back tandem seats forming an arc according to one embodiment of the invention. A first single row of tandem seat frames with an electrical wire way 1 are arranged in an arc formation. A seat frame without an electrical wire way 2 may be connected to the first single row of tandem seat frames with an electrical wire way 1 at random intervals. The shape and size of the seats 10 can be varied to accommodate the arrangement the specifier desires. The electrical/data ports 4 are accessible from the cover plate 3 to persons sitting in any seat of this configuration.
FIG. 18A is a top view of a row of back to back tandem seats forming an arc more fully described in FIG. 18 according to one embodiment of the invention.
In one particularly preferred embodiment, the following parts are incorporated into the seating system: a row of tandem seat frames with an electrical wire way 1 ; a row of tandem seat frames without an electrical wire way 2 ; a cover plate 3 ; electrical and/or data ports 4 ; a lower seat frame 5 ; electrical wiring 6 ; an arm frame 7 ; a lounge arm frame 8 ; a corner table 9 ; a seat 10 ; a monitor 11 ; a table with affixed storage box 12 ; a table 13 ; optional routing for electrical wiring 14 ; an electrical floor box assembly 15 ; a storage box 16 ; a cylindrical container 17 ; a high table 18 ; and a banquet seat 19 . | A seating system designed to accommodate a variety of activities that can be performed while a person is sitting or resting, and more particularly waiting. A single tandem row of seats or a back to back configuration of tandem seats has an electrical wire way extending behind or between each seat back, respectively. A cover plate encloses the wire way, and a plurality of electrical and data ports are accessible from the cover plate. Laptop computers, music players and other electrical devices can be plugged into the seating system so that the user can comfortably operate such a device while waiting. | 0 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation application of International Application No. PCT/JP2015/000446, filed Feb. 2, 2015. The contents of the aforementioned applications are incorporated herein by reference in their entireties.
TECHNICAL FIELD
[0002] The present invention relates to a method of manufacturing a perpendicular magnetic tunnel junction (MTJ) device.
BACKGROUND ART
[0003] Next-generation spin transfer torque magnetoresistive random access memories (STT-MTRAMs) use perpendicular MTJ devices, the magnetization direction of which is perpendicular to the film surface. Each of layers constituting a perpendicular MTJ device is very thin, and the properties thereof are liable to degrade when the perpendicular MTJ device is exposed to the atmosphere during the process of film formation. In the technique of Non-patent document 1, the entire process is consistently performed under vacuum in order to prevent degradation of the properties of the barrier layer and the perpendicular magnetic anisotropy layer.
[0004] At the same time, it is necessary to measure both the magnetoresistance (MR) properties and the perpendicular magnetic properties for management of the process of manufacturing MTJ devices. For this reason, in the technique of Non-patent Document 1, inspection of the MR (magnetoresistance) properties and perpendicular magnetic anisotropy properties is performed for completed perpendicular MTJ devices.
CITATION LIST
Non Patent Document
[0005] Non Patent Document 1: D. C. Worledge et al., Appl. Phys. Lett. 98, 022501 (2011)
SUMMARY OF INVENTION
Technical Problem
[0006] However, with the conventional method that performs property inspections for completed perpendicular MTJ devices, in the case of trouble such as the case where desired properties are not obtained and the yield is thereby reduced, it is difficult to identify the cause of such a trouble.
[0007] Accordingly, in the light of the aforementioned problem, an object of the present invention is to provide a method of manufacturing a perpendicular MTJ device which separately includes a step of inspecting the MR properties and a step of inspecting the perpendicular magnetic anisotropy properties.
Solution to Problem
[0008] An embodiment of the present invention is a method of manufacturing a perpendicular MTJ device which includes: a first stacked structure including a pair of CoFeB layers sandwiching an MgO layer; and a second stacked structure including a multilayer, the method comprising the steps of: forming one of the first and second stacked structures on a substrate; inspecting a property of the substrate with the one of the first and second stacked structures formed thereon while exposing the substrate to an atmosphere; and forming an other one of the first and second stacked structures on the substrate with the one of the first and second stacked structures formed thereon.
Advantageous Effects of Invention
[0009] With the method of manufacturing a perpendicular MTJ device according to the embodiment of the present invention, the management of the properties of the perpendicular MTJ device can be simplified. Specifically, the method of manufacturing a perpendicular MTJ device separately includes the step of forming the stacked structure influencing the MR properties and the step of forming the stacked structure influencing the perpendicular magnetic anisotropy properties, and separately performs the steps of inspecting the MR properties and perpendicular magnetic anisotropy properties. Accordingly, in the case of trouble such as the case where the desired properties are not obtained, it is possible to easily identify which stacked structure causes the trouble.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1A is a schematic diagram illustrating a layer structure of a top-pinned perpendicular MTJ device.
[0011] FIG. 1B is a schematic diagram illustrating a layer structure of a bottom-pinned perpendicular MTJ device.
[0012] FIG. 2A is a schematic diagram illustrating separate film formation of the top-pinned perpendicular MTJ device.
[0013] FIG. 2B is a schematic diagram illustrating separate film formation of the top-pinned perpendicular MTJ device.
[0014] FIG. 2C is a schematic diagram illustrating separate film formation of the top-pinned perpendicular MTJ device.
[0015] FIG. 2D is a schematic diagram illustrating separate film formation of the top-pinned perpendicular MTJ device.
[0016] FIG. 3A is a schematic diagram illustrating separate film formation of the bottom-pinned perpendicular MTJ device.
[0017] FIG. 3B is a schematic diagram illustrating separate film formation of the bottom-pinned perpendicular MTJ device.
[0018] FIG. 3C is a schematic diagram illustrating separate film formation of the bottom-pinned perpendicular MTJ device.
[0019] FIG. 4 is a schematic configuration diagram of a manufacturing system including a single-core sputtering apparatus.
[0020] FIG. 5 is a schematic configuration diagram of a double-core sputtering apparatus.
[0021] FIG. 6 is a flowchart according to a method of manufacturing a top-pinned perpendicular MTJ device.
[0022] FIG. 7 is a flowchart according to a method of manufacturing a bottom-pinned perpendicular MTJ device.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0023] FIGS. 1A and 1B are schematic diagrams illustrating a layered structure of a perpendicular MTJ device according to a first embodiment of the present invention. The thickness of each layer illustrated in the drawings is consistently schematic and does not suggest a relative thickness of each layer of a perpendicular MTJ device actually manufactured.
[0024] The perpendicular MTJ device includes a top-pinned perpendicular MTJ device 100 A ( FIG. 1A ) and a bottom-pinned perpendicular MTJ device 100 B ( FIG. 1B ).
[0025] A description is given of the top-pinned perpendicular MTJ device 100 A illustrated in FIG. 1A . The top-pinned perpendicular MTJ device 100 A includes a bottom electrode 102 , a Ta layer (a seed layer) 103 , a CoFeB layer 104 as a free layer (a magnetization free layer), a MgO layer (a tunnel barrier layer) 105 , and a CoFeB layer 106 as a reference layer (a magnetization fixed layer), which are sequentially provided on a substrate 101 made of silicon or the like.
[0026] The top-pinned perpendicular MTJ device 100 A further includes a Ta layer 107 , superlattice [Co/Pt] multilayer 110 A, an Ru layer 110 C, superlattice [Co/Pt] multilayer 110 B, an Ru layer 115 (a cap layer), a Ta layer 111 , and a top electrode 112 , which are sequentially provided on the CoFeB layer 106 . The [Co/Pt] multilayers 110 A and 110 B include predetermined numbers of Co layers and Pt layers alternately stacked on each other. A Ru layer 110 C is a layer to magnetically couple the upper [Co/Pt] multilayer 110 B to the lower [Co/Pt] multilayer 110 A.
[0027] The number of pairs of Co and Pt layers adjacent to each other in the [Co/Pt] multilayer 110 A is three to five, and the number of pairs of Co and Pt layers adjacent to each other in the [Co/Pt] multilayer 110 B is 8 to 15. The numbers of pairs are not limited to these values. Additionally, the [Co/Pt] multilayers 110 A and 110 B may be replaced with [Co/Pd] multilayers including Pd layers instead of the Pt layers. Moreover, the thicknesses of the Ta layer 103 , CoFeB layer 104 , MgO layer 105 , CoFeB layer 106 , and Ta layer 107 are 10 nm, 1.1 nm, 1 nm or less, 1.4 nm, and 0.3 nm, respectively.
[0028] The bottom-pinned perpendicular MTJ device 100 B illustrated in FIG. 1B includes the same layers as those of the top-pinned perpendicular MTJ device 100 A. The CoFeB layer 106 as a reference layer (a magnetization fixed layer) is provided on the side far from the substrate 101 , and the multilayers 110 B and 110 A are therefore provided between the substrate 101 and CoFeB layer 106 . Additionally, the bottom-pinned perpendicular MTJ device 100 B further includes a Ru layer 116 as a seed layer under the multilayer 110 B. The Ru layer 116 is a layer to improve the crystalline orientation of the [Co/Pt] multilayer 110 B. The structures illustrated in FIGS. 1A and 1B are just examples, and the [Co/Pt] multilayers 110 A and 110 B may be made of materials having perpendicular magnetization. Instead of the [Co/Pt] multilayers 110 A and 110 B, TbFeCo, [Co/Ni] multilayers, CoPt or FePt, which are ordered alloys, or the like, may be used, for example.
[0029] The configurations of the perpendicular MTJ devices (of top-pinned and bottom-pinned types) according to the embodiment are not limited to the configurations illustrated herein and any change, such as increase or decrease in the number of layers, change in the constituent materials of the layers, and reversing the order of layers upside down, may be made as long as it does not degrade the functions of the perpendicular MTJ device.
[0030] Next, a description is given of separate film formation in the method of manufacturing the top-pinned perpendicular MTJ device 100 A, which is a perpendicular MTJ device, using FIGS. 2A to 2D .
[0031] In the method of manufacturing the top-pinned perpendicular MTJ device 100 A according to the embodiment, the part concerning a first stacked structure 10 of the top-pinned perpendicular MTJ device 100 A is first formed on the substrate, and property inspection is performed. The part concerning a second stacked structure 20 of the top-pinned perpendicular MTJ device 100 A is then formed, and different property inspection is performed. Herein, the first stacked structure 10 includes at least the CoFeB layer 104 , MgO layer 105 , and CoFeB layer 106 , and the second stacked structure 20 includes at least the superlattice [Co/Pt] multilayers 110 A and 110 B.
[0032] To be specific, the first stacked structure 10 is formed on the substrate 101 under vacuum in a first film formation apparatus. The substrate with the first stacked structure 10 formed thereon is then taken out of the first film formation apparatus to be exposed to the atmosphere and is inspected in terms of the MR properties. The substrate is then etched back under vacuum in another second film formation apparatus, and the second stacked structure 20 is further formed on the same, producing the top-pinned perpendicular MTJ device 100 A. The top-pinned perpendicular MTJ device 100 A is then taken out of the second film formation apparatus and is inspected in terms of the perpendicular magnetic anisotropy properties.
[0033] Herein, the inspection of the MR properties is performed using a current in-plane tunneling (CIPT) measuring device or the like after a lower electrode layer necessary for the inspection is formed on the substrate with the first stacked structure 10 not yet formed thereon and then an upper electrode layer necessary for the inspection is formed on the substrate with the first stacked structure 10 formed thereon. The inspection of the perpendicular magnetic anisotropy properties is performed using a vibrating sample magnetometer (VSM) measuring device or the like. The property inspections are performed in a cleanroom with a low level of dust. The different second film formation apparatus does not need to be used if both of the first and second stacked structures 10 and 20 can be formed by only the first film formation apparatus to produce the top-pinned perpendicular MTJ device 100 A.
[0034] The perpendicular MTJ device is separated into the first and second stacked structures 10 and 20 based on the Ta layer (also referred to as SpacerTa) 107 . The separation may be based on another layer if the first stacked structure 10 includes at least the CoFeB layer 104 , MgO layer 105 , and CoFeB layer 106 and the second stacked structure 20 includes at least the superlattice [Co/Pt] multilayers 110 A and 110 B. As illustrated in FIG. 2A , the Ta layer 107 of the first stacked structure 10 needs to be made comparatively thick in light of partially removing the Ta layer 107 by etching. Controlling the thickness of each of the CoFeB layer 104 , MgO layer 105 , CoFeB layer 106 , and superlattice [Co/Pt] multilayers 110 A and 110 B within 2 nm enables the perpendicular MTJ device to fulfill the function thereof. In the embodiment, the Ta layer 107 is formed into a thickness of about 3 nm at first and is then etched back to be controlled to 2 nm or less. However, the Ta layer 107 may be etched back by 1 nm or more.
[0035] The thickness of oxide film generated in the surface of the Ta layer 107 through exposure to the atmosphere depends on diffusion of oxygen into the Ta layer 107 , which correlates to the time when the Ta layer 107 is left under the atmosphere, the atmosphere temperature, and the like. How thick the oxide film will be formed in the Ta layer 107 can be experimentally found based on the inspection time, environmental temperature, and the like of the property inspection after the treatment conducted in the first film formation apparatus. Accordingly, it is also experimentally found to what extent the Ta layer 107 needs to be removed in the etch-back process.
[0036] As illustrated in FIG. 2B , after the process to etch a part of the Ta layer 107 (etch-back process), the second stacked structure 20 is formed starting from the Co layer of the [Co/Pt] multilayer 110 A, so that the top-pinned perpendicular MTJ device 100 A illustrated in FIG. 1A is eventually produced.
[0037] To be specific, in the manufacture of the top-pinned perpendicular MTJ device 100 A, the substrate on which the first stacked structure 10 is formed up to the Ta layer 107 under vacuum is taken out of the first film formation apparatus and is then inspected in terms of the MR properties in the cleanroom under the atmosphere. The substrate is then introduced into the second film formation apparatus, and a part (an oxidized part) of the Ta layer 107 is etched under vacuum (etch-back process). Thereafter, the upper layers are formed starting from a Co layer of the [Co/Pt] multilayer 110 A. After the top electrode 112 is formed, the substrate is taken out of the second film formation apparatus and is inspected in terms of the perpendicular magnetic anisotropy properties.
[0038] Note that as illustrated in FIG. 2C , after a part of the Ta layer 107 is etched (etch-back process), the upper layers may be formed starting from a Ta layer 107 A. Note that the Ta layers 107 and 107 A are formed under the same film formation conditions using the same material. Alternatively, as illustrated in FIG. 2D , the CoFeB layer 106 may be made comparatively thick and the thus-obtained substrate is taken out of the first film formation apparatus and undergoes the property inspection. Thereafter, in the second film formation apparatus, a part of the CoFeB layer 106 is etched and the upper layers may be formed starting from the Ta layer 107 .
[0039] Next, a description is given of separate film formation in the method of manufacturing the perpendicular MTJ device (the bottom-pinned perpendicular MTJ device 100 B) using FIGS. 3A to 3C .
[0040] Similarly to the aforementioned method, in the method of manufacturing the bottom-pinned perpendicular MTJ device 100 B according to the embodiment, the property inspection is performed after the part concerning the second stacked structure 21 of the bottom-pinned perpendicular MTJ device 100 B is formed on the substrate, and the different property inspection is then performed after the part concerning the first stacked structure 11 of the bottom-pinned perpendicular MTJ device 100 B is further formed. Herein, the first stacked structure 11 includes at least the CoFeB layer 104 , MgO layer 105 , and CoFeB layer 106 , and the second stacked structure 21 includes at least the superlattice [Co/Pt] multilayers 110 A and 110 B.
[0041] The Ta layer 107 of the second stacked structure 21 is made comparatively thick as illustrated in FIG. 3A . After the process to etch a part of the Ta layer 107 (etch-back process) as illustrated in FIG. 3B , the first stacked structure 11 is formed starting from the CoFeB layer 106 of the first stacked structure 11 , so that the bottom-pinned perpendicular MTJ device 100 B illustrated in FIG. 1B is eventually produced.
[0042] In the manufacture of the bottom-pinned perpendicular MTJ device 100 B illustrated in FIGS. 3A and 3B , the substrate on which the second stacked structure 21 is formed up to the Ta layer 107 is taken out of the first film formation apparatus and is then inspected in terms of the perpendicular magnetic anisotropy properties in the cleanroom under the atmosphere. The substrate is then introduced into the second film formation apparatus, and a part (an oxidized part) of the Ta layer 107 is etched under vacuum (the etch-back process). Thereafter, the upper layers are formed starting from the CoFeB layer 106 . After the top electrode 112 is formed, the substrate is taken out of the second film formation apparatus and is inspected in terms of the MR properties.
[0043] As illustrated in FIG. 3C , after forming a Co layer that is the topmost layer of the [Co/Pt] multilayer 110 A of the second stacked structure 21 comparatively thick, the substrate may be taken out of the first film formation apparatus and then be inspected for properties. Thereafter, the first stacked structure 11 is formed starting from the Ta layer 107 after a part of the Co layer is etched in the second film formation apparatus.
[0044] FIG. 4 is a schematic configuration diagram of a manufacturing system 400 including single-core sputtering apparatuses 410 and 420 as the first and second film formation apparatuses used in the method of manufacturing a perpendicular MTJ device according to the embodiment.
[0045] In manufacture of the top-pinned perpendicular MTJ device 100 A, the sputtering apparatus 410 is the first film formation apparatus to form the first stacked structure 10 , and the sputtering apparatus 420 is the second film formation apparatus to form the second stacked structure 20 . On the other hand, in manufacture of the bottom-pinned perpendicular MTJ device 100 B, the sputtering apparatus 410 is the first film formation apparatus to form the second stacked structure 21 , and the sputtering apparatus 420 is the second film formation apparatus to form the first stacked structure 11 .
[0046] The manufacturing system 400 further includes property inspection apparatuses 430 and 440 . In manufacture of the top-pinned perpendicular MTJ device 100 A, the property inspection apparatus 430 is a CIPT measuring device for inspection of the MR properties, and the property inspection apparatus 440 is a VSM measuring device for inspection of the perpendicular magnetic anisotropy properties. On the other hand, in manufacture of the bottom-pinned perpendicular MTJ device 100 B, the property inspection apparatus 430 is a VSM measuring device, and the property inspection apparatus 440 is a CIPT measuring device. The following description relates to the manufacturing system 400 for the top-pinned perpendicular MTJ device 100 A unless otherwise noted. The manufacturing system 400 for the bottom-pinned perpendicular MTJ device 100 B is the same as that for the top-pinned perpendicular MTJ device 100 A other than the differences in the order of formed layers and target materials.
[0047] The sputtering apparatus 410 includes an equipment front end module (EFEM) 411 , a load lock chamber 412 , a vacuum transfer chamber 413 , an etching chamber 414 , metal deposition chambers 415 to 417 , an oxidation chamber 418 , and a degassing chamber 419 . Each chamber is kept evacuated.
[0048] The EFEM 411 transports a substrate into and out of the load lock chamber 412 . The load lock chamber 412 adjusts the inside of the chamber to vacuum and transports the substrate to the vacuum transfer chamber 413 . The vacuum transfer chamber 413 includes a robot loader to load and unload the substrate to a robot feeder (not illustrated) within each chamber 414 to 419 . The etching chamber 414 performs dry etching such as capacitively-coupled plasma (CCP) etching, inductively-coupled plasma (ICP) etching, or ion beam etching. In the metal deposition chambers 415 to 417 , the target materials used to form the layers of the first stacked structure 10 , such as a Ta target, a CoFeB target, and an Mg target, for example, are provided, and each layer is formed on the substrate by sputtering. The oxidation chamber 418 performs oxidation for the substrate.
[0049] The sputtering apparatus 420 includes an EFEM 421 , a load lock chamber 422 , a vacuum transfer chamber 423 , an etching chamber 424 , metal deposition chambers 425 to 428 , and a degassing chamber 429 . The inside of each chamber is kept evacuated. The EFEM 421 , load lock chamber 422 , vacuum transfer chamber 423 , and degassing chamber 429 are the same as those of the sputtering apparatus 410 . In the metal deposition chambers 425 to 428 , the target materials used to form each layer of the second stacked structure 20 , such as a Co target, a Pt target, a Ru target, and a Ta target, for example, are provided, and each layer is formed on the substrate by sputtering.
[0050] The substrate is transported between the sputtering apparatuses 410 and 420 and the property inspection apparatuses 430 and 440 through a transfer path (not illustrated) or by an operator.
[0051] Hereinafter, the embodiment is described in more detail. First, a substrate 101 is transported into the load lock chamber 412 through the EFEM 411 of the first film formation apparatus 410 . The robot loader of the vacuum transfer chamber 413 is then driven to sequentially move the substrate from the load lock chamber 412 to the predetermined substrate treatment chambers 414 to 419 , thus forming the first stacked structure 10 (or the second stacked structure 21 ).
[0052] In manufacture of the top-pinned perpendicular MTJ device 100 A, etching is performed in the first film formation apparatus 410 to remove impurities and the like attached to the substrate 101 . Thereafter, the bottom electrode 102 , Ta layer 103 , CoFe layer 104 , MgO layer 105 , CoFeB layer 106 as the reference layer, and Ta layer 107 are sequentially formed on the substrate 101 by sputtering, thus forming the first stacked structure 10 .
[0053] On the other hand, in manufacture of the bottom-pinned perpendicular MTJ device 100 B, etching is performed in the first film formation apparatus 410 to remove impurities and the like attached to the substrate 101 . Thereafter, the bottom electrode 102 , Ta layer 103 , and the multilayers 110 A and 110 B are sequentially formed on the substrate 101 by sputtering, thus forming the second stacked structure 21 .
[0054] Next, the substrate is ejected from the first film formation apparatus 410 through the load lock chamber 412 and EFEM 411 to be exposed to the atmosphere. The substrate then undergoes the property inspection (the inspection of the MR properties or perpendicular magnetic anisotropy properties) in the property inspection apparatus 430 . Thereafter, the substrate is transferred into the load lock chamber 422 through the EFEM 421 of the second film formation apparatus 420 . The robot loader of the vacuum transfer chamber 423 is driven to move the substrate from the load lock chamber 422 sequentially to the predetermined substrate treatment chambers 424 to 429 , thus forming the second stacked structure 20 (or the first stacked structure 11 ).
[0055] In the manufacture of the top-pinned perpendicular MTJ device 100 A, etching is performed to remove impurities attached to the Ta layer 107 , oxide film formed in the Ta layer, and the like in the second film formation apparatus 420 . Thereafter, the multilayer 110 A, Ru layer 110 C, multilayer 110 B, Ru layer 115 , Ta layer 111 , and top electrode 112 are sequentially formed by sputtering. On the other hand, in the manufacture of the bottom-pinned perpendicular MTJ device 100 B, etching is performed to remove impurities attached to the Ta layer 107 , oxide film formed in the Ta layer, and the like in the second film formation apparatus 420 . Thereafter, the CoFe layer 106 , MgO layer 105 , CoFeB layer 104 , Ta layer 111 , and top electrode 112 are sequentially formed by sputtering. The eventually formed top-pinned perpendicular MTJ device 100 A (or bottom-pinned perpendicular MTJ device 100 B) is ejected from the second film formation apparatus 420 and is then inspected in terms of the perpendicular magnetic anisotropy properties (or the MR properties) in the property inspection apparatus 440 .
[0056] The MgO layer 105 may be formed by radio-frequency (RF) sputtering using an MgO target or may be formed in such a manner that an Mg layer is formed on the CoFeB layer by sputtering using an Mg target and is then oxidized. The film formation and oxidation of Mg may be performed in the same substrate treatment chamber of the first film formation apparatus 410 (or the second film formation apparatus 420 ) or may be performed in different substrate treatment chambers that use a metal deposition chamber and an oxidation chamber.
[0057] The film formation apparatus used in the method of manufacturing a perpendicular MTJ device may be a double-core sputtering apparatus 500 as illustrated in FIG. 5 . The double-core sputtering apparatus 500 can also implement the method of manufacturing a perpendicular MTJ device according to the embodiment. By using the double-core sputtering apparatus 500 , the number of chambers capable of performing deposition per film formation apparatus is increased, and more perpendicular MTJ devices can be manufactured than manufactured by the single-core sputtering apparatus.
[0058] FIG. 6 is a flowchart for explaining the method of manufacturing the top-pinned perpendicular MTJ device 100 A, which is the perpendicular MTJ device according to the embodiment.
[0059] In S 601 , the bottom electrode 102 , Ta layer 103 , CoFeB layer 104 , MgO layer 105 , CoFeB layer 106 , and Ta layer 107 are sequentially formed on the substrate 101 in the first film formation apparatus 410 , thus forming the first stacked structure 10 . As described above, the first stacked structure 10 may be formed in such a manner that the CoFeB layer 106 is made comparatively thick and the Ta layer 107 is not formed as the first stacked structure 10 but formed as the second stacked structure 20 .
[0060] In S 602 , the substrate with the first stacked structure 10 formed thereon is taken out of the first film formation apparatus 410 to be exposed to the atmosphere, and the electrode layer and the like necessary for the property inspection are formed thereon. In S 603 , inspection of the MR properties is performed in the property inspection apparatus 430 , which is a CIPT measuring device. Accordingly, the property inspection is performed for the substrate with only the first stacked structure 10 formed thereon before the second stacked structure 20 is formed. This facilitates management of the properties attributed to the first stacked structure 10 .
[0061] Next, in step S 604 , etching is performed in the second film formation apparatus 420 after the property inspection for the first stacked structure 10 is completed because the topmost layer (the Ta layer 107 or CoFeB layer 106 ) of the first stacked structure 10 has been exposed to the atmosphere and naturally oxidized. The etching is dry etching using Ar gas, such as capacitively-coupled plasma (CCP) etching, inductively-coupled plasma (ICP) etching, or ion beam etching, for example.
[0062] In S 605 , the multilayer 110 A, Ru layer 110 C, multilayer 110 B, Ru layer 115 , Ta layer 111 , and top electrode 112 (in addition, the Ta layer 107 if necessary) are formed in the second film formation apparatus 420 , thus forming the second stacked structure 20 . Since the property inspection (MR properties) for the first stacked structure 10 is already performed, in 5606 , inspection of the properties different from the MR properties, that is, perpendicular magnetic anisotropy properties, is performed in the property inspection apparatus 440 , which is a VSM measuring device, after the second stacked structure 20 is formed.
[0063] FIG. 7 is a flowchart for explaining the method of manufacturing the bottom-pinned perpendicular MTJ device 100 B, which is the perpendicular MTJ device according to the embodiment.
[0064] In S 701 , the bottom electrode 102 , Ta layer 103 , Ru layer 106 , multilayer 110 B, Ru layer 110 C, multilayer 110 A, and Ta layer 107 are sequentially formed on the substrate 101 in the first film formation apparatus 410 , thus forming the second stacked structure 21 . As described above, the second stacked structure 21 may be formed in such a manner that the Co layer at the topmost layer of the multilayer 110 A is made comparatively thick and the Ta layer 107 is not formed as the second stacked structure 21 but formed as the first stacked structure 11 .
[0065] In S 702 , the substrate with the second stacked structure 21 formed thereon is taken out of the first film formation apparatus 410 to be exposed to the atmosphere, and the electrode layer and the like necessary for the property inspection are formed thereon. In S 703 , inspection of the perpendicular magnetic anisotropy properties is performed in the property inspection apparatus 430 , which is a VSM measuring device. The property inspection is thus performed for the substrate with only the second stacked structure 21 formed thereon before the first stacked structure 11 is formed. This facilitates management of the properties attributed to the second stacked structure 21 .
[0066] Next, in step S 704 , etching is performed in the second film formation apparatus 420 after the property inspection for the second stacked structure 21 is completed because the topmost layer (the Ta layer 107 or Co layer) of the second stacked structure 21 has been exposed to the atmosphere and naturally oxidized. The etching is dry etching using Ar gas, such as capacitively-coupled plasma (CCP) etching, inductively-coupled plasma (ICP) etching, or ion beam etching, for example.
[0067] In S 705 , the CoFeB layer 106 , MgO layer 105 , CoFeB layer 104 , Ta layer 111 , and top electrode 112 (in addition, the Ta layer 107 if necessary) are formed in the second film formation apparatus 420 , thus forming the first stacked structure 11 . Since the property inspection for the second stacked structure 21 (perpendicular magnetic anisotropy properties) is already performed, in 5706 , inspection of the MR properties is performed in the property inspection apparatus 440 , which is a CIPT measuring device, after the first stacked structure 11 is formed.
[0068] As described above, by separately performing the property inspections for the perpendicular MTJ device in the middle and after manufacture thereof, inspection of the MR properties is performed when the first stacked structure including the CoFeB layer 104 , MgO layer 105 , and CoFeB layer 106 is formed, and inspection of the perpendicular magnetic anisotropy properties is performed when the second stacked structure including the multilayers 110 A and 110 B is formed. Accordingly, in order that products (the substrates with only the first or second stacked structure formed thereon or the substrates with the first and second stacked structures formed) by the apparatuses that form the first and second stacked structures have desired properties, it is only necessary to adjust the conditions of each apparatus (control conditions of sputtering and the like), the film thickness and the material type of each layer, and the like. This clarifies the roles of the apparatuses and simplifies the management of the properties of perpendicular MTJ devices.
[0069] For example, the perpendicular magnetic anisotropy properties are guaranteed only by controlling the thickness of each layer at forming the second stacked structure, and the second stacked structure can be formed even if the film formation apparatus to form the first stacked structure is malfunctioning. Moreover, by increasing the number of modules performing substrate treatment in each apparatus used in film formation, the throughput can be increased. For example, using the double-core sputtering apparatus 500 illustrated in FIG. 5 can double the throughput compared with the single-core sputtering apparatus 410 or 420 illustrated in FIG. 4 .
[0070] In the conventional method, property inspections of both the MR properties and perpendicular magnetic anisotropy properties are performed for a perpendicular MTJ device with both the first and second stacked structures formed thereon. Accordingly, in the case where the MR properties attributed to the first stacked structure are different from desired values, for example, the entire perpendicular MTJ device needs to be discarded even if the perpendicular magnetic anisotropy properties attributed to the second stacked structure are normal. The film formation treatment to form the second stacked structure is wasted, resulting in cost of production loss. However, according to the method of manufacturing a perpendicular MTJ device according to the embodiment, in case of trouble of film formation apparatuses, it is possible to determine that the apparatus which has formed the first stacked structure is malfunctioning when the MR properties include a problem, or it is possible to determine that the apparatus which has formed the second stacked structure is malfunctioning when the perpendicular magnetic anisotropy properties include a problem. It is therefore possible to easily identify the cause of the malfunctioning apparatus, thus reducing the cost of production loss in case of trouble.
Other Embodiment
[0071] The method of manufacturing a perpendicular MTJ device according to the present invention is not limited to manufacture of perpendicular MTJ devices including the configurations illustrated in FIGS. 1A and 1B and is applicable to manufacture of any type of perpendicular MTJ devices. Using the manufacturing method according to the present invention can reduce the cost concerning controlling the conditions of the film formation apparatus for perpendicular MTJ devices having desired properties. | An embodiment of the present invention is a method of manufacturing a perpendicular MTJ device which includes: a first stacked structure including a pair of CoFeB layers sandwiching an MgO layer; and a second stacked structure including a multilayer, the method comprising the steps of: forming one of the first and second stacked structures on a substrate; inspecting a property of the substrate with the one of the first and second stacked structures formed thereon while exposing the substrate to the atmosphere; and forming another one of the first and second stacked structures on the substrate with the one of the first and second stacked structures formed thereon. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/591,964, filed on Jan. 29, 2012, which is fully incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a reporting and monitoring system using mobile computing devices and, more particularly, to a system and method for alerting authorities to and monitoring crimes, safety hazards or other perceived problems.
BACKGROUND INFORMATION
[0003] While investigative and monitoring technologies have improved in recent years, evidence and information obtained from bystanders and other witnesses remain critical tools for law enforcement, safety, school and other officials. Additionally, when such information is obtained from bystanders, the monitoring of the bystander reports provides such officials with another tool to combat crime and locate hazards. Unfortunately, crimes and safety hazards often go unreported by these important witnesses for various reasons including, for example, time pressure, desire to avoid police interaction, self preservation and protection, etc. A need, therefore, exists for a method and/or system for increasing bystander reporting.
[0004] In general, computing devices, such as mobile smartphones and laptop computers, may include various image, audio and video collection systems. One way to increase bystander reporting is by using a computing device to capture images, audio and video and sending the package of information to authorities in order to provide them with a better understanding of the situation. Conventional mobile smartphones often require several applications to capture images, audio and video and to send information and do not include an application that integrates these functions for reporting and monitoring crimes, safety hazards, or other perceived problems.
SUMMARY
[0005] To address the needs discussed above, the described embodiments provide methods and systems allowing users to report crimes, safety hazards or other perceived problems and send them to an alert report database so that a plurality of users are able to monitor such crimes, safety hazards or other perceived problems. In some example embodiments, the reporting system includes a computing device including, but not limited to, a mobile smartphone, tablet device, laptop computer or desktop computer programmed with a software application and a host computer system.
[0006] According to one embodiment of the crime and safety reporting and monitoring method, a preferred incident database is established comprising user identifying information and any information provided regarding the crime, safety hazard or other perceived problem. A crime and alert report database may be created on a host computer system, the crime and alert report database including a plurality of alert reports including alert reporter information, alert information, and alert data. A report map may also be created on the host computer system, the report map including the plurality of alert reports plotted according to geographic location. The host computer system then provides access, via the report map displayed on a user mobile computer system, to the alert reporter information, the alert information and the alert data, wherein the report map enables a plurality of alert reporters to contribute to an alert report.
[0007] One exemplary embodiment consistent with the present invention relates to a method for bystander reporting. The bystander reporting and monitoring system includes a user via a user application creating an alert report on the create alert screen with the user application being configured to send alert reporter information and alert information associated with a new alert report from a user mobile computer system to a host computer system. The user application sends the alert reporter information and alert information from the user to the host computer system, wherein the sent alert reporter information and alert information is associated with the new alert report. The host computer system receives the alert report from the user with alert reporter information and alert information provided by the user via the user application. The host computer system stores the alert reporter information and alert information via an alert report database. The user may capture streaming video, audio clips, video clips or pictures via a capture alert data screen and sends the alert data captured by the user to the host computer system, wherein the sent alert data is associated with the new alert report. After receiving the alert data from the user, the host computer system stores the alert data via the alert report database and provides access to the alert report database and an alert report map, wherein the user, via user application, can access the sent alert report and the report map enables a plurality of alert reporters to contribute to the new alert report.
[0008] Another exemplary embodiment consistent with the present invention relates to a system for bystander monitoring. The system for bystander monitoring includes a user computing device, which includes systems to capture images, audio and/or video and send such information to another computing device. The host computer system provides access to an alert report map and is displayed on a user mobile computer system via a user application, wherein the alert report map enables a plurality of alert reporters to contribute to an alert report. The alert report map allows the user to select an alert report located on the alert report map. After selecting an alert report, an update alert screen is displayed via the user application where the user application is configured to send alert reporter information and alert information associated with the alert report from a user mobile computer system to a host computer system.
[0009] After receiving an updated alert report from the user with updated alert reporter information and updated alert information provided by the user via the user application, the host computer system stores the updated alert reporter information and updated alert information via an alert report database. A capture alert data screen is displayed to the user via the user application, the user application being configured to send alert data from the user mobile computer system to the host computer system. The updated alert data captured by the user is sent to the host computer system, wherein the sent updated alert data is associated with the alert report. The host computer system receives the updated alert data from the user wherein the sent updated alert data is associated with the alert report and stored via an alert report database. The host computer system then provides access to the alert report database and report map, wherein the user, via user application, can access the sent alert report and the report map enables a plurality of alert reporters to contribute to the alert report.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and other features and advantages will be better understood by reading the following detailed description, taken together with the drawings wherein:
[0011] FIG. 1 is a diagrammatic view of a crime or alert reporting network, consistent with an embodiment of the present invention.
[0012] FIG. 2 is a diagrammatic view of a mobile alert reporting and monitoring system, consistent with an embodiment of the present invention.
[0013] FIG. 3 is a functional block diagram of a system for creating an alert report, consistent with an embodiment of the present invention.
[0014] FIG. 4 is a functional block diagram of a system for monitoring an alert report, consistent with an embodiment of the present invention.
[0015] FIG. 5A-5C are screen shots illustrating a mobile alert reporting and monitoring system user application home screen, alert creation prompt, and alert creation screen, respectively, consistent with an embodiment of the present invention.
[0016] FIGS. 6A and 6B are screen shots illustrating an alert report screen and a create alert report screen, consistent with an embodiment.
[0017] FIGS. 7A and 7B are screen shots illustrating a monitoring alert report screen and an update alert report screen, consistent with an embodiment.
DETAILED DESCRIPTION
[0018] The computerized systems and methods, consistent with embodiments of the present invention described herein, enable mobile crime and alert reporting. Mobile crime and alert reporting may be enabled by allowing multiple users to report incidents and crimes and to send streaming video, video clips, pictures, and audio clips to authorities and other users. Users may be enabled to monitor existing reports and also contribute to the report with additional information or streaming video, video clips, pictures, and audio clips. If an alert is considered to be an emergency, mobile crime and alert reporting may be enabled by sending the alert to the nearest authorities based on the location of the user mobile computer system. Although a crime and alert reporting system and method is described herein, the systems and methods described herein are not limited to reporting crimes and may be used to report other incidents or events, which may or may not be crimes.
[0019] As used herein, an “alert report” refers to a report of a crime, incident, or hazard and includes the information of the reporter, information of the crime, incident, or hazard, and alert data pertaining to the crime, incident, or hazard. “Alert reporter information” refers to the user's personal and/or identifying information such as, for example, name, e-mail address, telephone number, address, emergency contact information, medical contact information, and geographic location. “Alert information” refers to any information describing the crime, incident, or hazard such as, for example, geographic location, text descriptions, and whether or not the alert is an emergency. An “alert data” refers to any data files or clips associated with the crime, incident, or hazard that is uploaded such as, for example, streaming video, video clips, pictures, and audio clips.
[0020] Referring to FIG. 1 , a mobile alert reporting and monitoring system 100 may be used to establish a network of users who access the system 100 over a network 102 such as the Internet or any cellular network by way of cellular technology such as GSM (Global System for Mobile Communications), CDMA (Code Division Multiple Access), and AMPS (Advanced Mobile Phone System). Examples of these cellular networks include mobile communications standards such as 3G (e.g., UMTS, CDMA2000) and 4G (e.g., Mobile WiMAX, LTE). The system 100 allows the users to create new alert reports and also contribute to existing alert reports over the network 102 to alert each other and the closest authorities to potential dangers and other incidents.
[0021] The mobile alert reporting and monitoring system 100 may be implemented using a combination of hardware and software. The hardware may generally include a host computer system 110 , mobile computer systems 130 , 150 , 170 , and computer systems 114 , 190 . The host computer system 110 is a server that is used to store alert reports in the form of a database as well as a map. This host computer system 110 provides database and map access to computer systems 114 , 130 , 150 , 170 , and 190 . Computer systems 130 , 150 , 170 are able to access the database and map on the host computer system by executing a mobile application or program 140 , 160 , 180 or a specialized interface that is installed on the computer systems 130 , 150 , 170 . Computer system 190 is a computer system used by the authorities (e.g., police, campus safety) and is able to access the database and map on the host computer system by executing a program 191 that is purchased and installed on the computer system 190 or a web-based interface.
[0022] Examples of mobile computer system 130 include the iPhone® smartphone and any smartphone device running mobile operating systems such as Android®, iOS®, or Windows®. Examples of mobile computer system 150 include the iPad® tablet computer and any tablet computer device running mobile operating systems such as Android®, iOS®, or Windows®. Examples of mobile computer system 170 include a laptop PC or MAC® computer.
[0023] Examples of mobile computer system 130 use cell towers used for the cellular network and Wi-Fi Internet network locations to determine GPS (Global Positioning System) location of the device. Other examples of the geographic location system in mobile computer system 130 included A-GPS (Assisted GPS) and GLONASS global positioning system. Examples of mobile computer system 150 use cell towers used for the cellular network and Wi-Fi Internet network locations to determine GPS (Global Positioning System) location of the device as well. Other examples of the geographic location system in mobile computer system 150 included A-GPS (Assisted GPS) and GLONASS global positioning system. Computer systems 114 , 170 , 190 may not have a geographic location system and therefore would require the user to input a specific geographic location (e.g., latitude and longitude, street address).
[0024] Examples of mobile computer systems 130 , 140 , 170 may use the microphone installed on the device to capture audio and create a file of the recording. Examples of mobile computer systems 130 , 140 , 170 may use the camera installed on the device to capture photographs. In some mobile operating systems such iOS®, the devices has the capability to embed location data in the pictures, producing geocoded photographs. In addition to the audio recording capability and picture capture capability, examples of mobile computer systems 130 , 140 , 170 may use the microphone and camera installed on the device to record video. Computer systems 114 , 190 may also use microphones or cameras installed on the device to capture audio, picture, and video.
[0025] The software may include code 120 for providing the functionality of the system and may include data generated and accessed by the system, such as alert reporter information 122 , alert information 124 , and alert data 126 . Users may access the database and map that contain the alert report 122 , 124 , and 126 over the network 102 . The application or program 128 , 140 , 160 , 180 , 191 executing on the computer systems or devices 114 , 130 , 150 , 170 , 190 can be used to enter alert reports to host computer system 110 and access the database and map. The software code 120 on the host computer system 110 may be executed to organize the new alert reports and to perform the processes, procedures or functions that enable mobile alert reporting and monitoring as described in greater detail below. As used herein, the terms process, procedure, and function are generally used interchangeably to refer to one or more actions performed by software being executed by a computer system to achieve a result. In particular, the application or program 128 , 140 , 160 , 170 , 191 may be executed to access or generate alert information 124 and to contribute to an alert report by uploading evidence stored as alert data 126 . All or a portion of the applications or programs executed on the user computer systems or devices and the code on the host computer system may be written in any suitable programming language, for example, in a procedural programming language (e.g., “C”) or an object-oriented programming language (e.g., “C++” or Java).
[0026] The host computer system 110 may be coupled to the network 102 and accessed by various user mobile computer systems 130 , 150 , and 170 coupled to the network 102 , for example, by using the mobile application or computer program. The host computer system 110 may include one or more server computers such as a server running a network operating system and may include one or more databases such as database software running on the server computer(s) or separate database computer(s). Although the host computer system 110 is shown as a single server unit, the host computer system 110 may include a combination of computers or computing components.
[0027] The users may access the mobile alert reporting system 100 using the computer systems 130 , 150 , 170 , and 190 that are connected to the network 102 and executing a mobile application or program 140 , 160 , 180 or a specialized interface. The user computer systems may be the user's laptop PC or MAC® computer 170 or may be a mobile computing device 130 or tablet computing device 150 . One example of the mobile computer device 130 is an iPhone® smartphone with a mobile alert reporting “app.” When the mobile application or program 140 , 160 , 180 is executed, the user may be presented with sections that allow the user to enter information, enter a new alert report, and monitor or update an existing alert report, as described in greater detail below.
[0028] An administrator computer system 114 may be coupled to the network 102 and used by an administrator to access and administer the mobile alert reporting and monitoring system 100 through an administrator program 128 or web based interface. The administrator computer system 114 may be located at the same location as the host computer system 110 or located remotely.
[0029] Referring to FIG. 2 , an embodiment of a mobile alert reporting and monitoring system 200 is described in greater detail. The mobile alert reporting and monitoring system 200 may include a host computer system 210 providing server code 220 , mobile alert reporting code 222 , mobile alert monitoring code 224 , or any combination thereof. The server code 220 may be executed on the host computer system 210 to allow user computer system 202 access to the alert report database 230 and alert report map 240 . The mobile alert reporting code 222 and mobile alert monitoring code 224 may include code executed on the host computer system 210 to perform at least some of the processes, procedures and/or functions associated with mobile alert reporting and monitoring.
[0030] Server code 220 may include instructions executed by the host computer system 210 to provide the user computer system 202 access to the alert report database 230 and alert report map 240 . The alert report database 230 may be created using any suitable database software or techniques known to those skilled in the art, and the alert report map 240 may be created using any suitable mapping software or techniques known to those skilled in the art. Access provided to the user computer system 202 by the server code 220 allows the user computer system 202 to enter new alert reports by executing mobile alert reporting code 222 or update existing alert reports by executing mobile alert monitoring code 224 . Both mobile alert monitoring code 222 and mobile alert monitoring code 224 interact with the alert report database 230 and alert report map 240 . When the user computer 202 uses program 203 to interact with the host computer system 210 , the server code 220 decides whether to provide access to the alert report database and alert report map to the user computer 202 , execute mobile alert reporting code 222 , or mobile alert monitoring code 224 .
[0031] The server code 220 may decide to execute mobile alert reporting code 222 . Mobile alert reporting code 222 may include instructions executed by the host computer system 210 to perform processes, procedures and/or functions involved with entering new alert reports to the alert report database and alert report map. The mobile application or program 203 may prompt the user to enter alert reporter information (e.g., name, e-mail address, telephone number, address, emergency contact information, medical contact information, and geographic location), alert information, and alert data. The mobile application or program 203 may then communicate with the host computer system 210 . When the server code 220 determines that the alert report is new, server code 220 then executes mobile alert reporting code 222 . Mobile alert reporting code 222 enters the alert report 232 , 234 , 236 into the alert report database 230 and the alert report map 240 .
[0032] The server code 220 may decide to execute mobile alert monitoring code 224 . Mobile alert reporting code 224 may include instructions executed by the host computer system 210 to perform processes, procedures and/or functions involved with updating existing alert reports, the alert report database and the alert report map. The mobile application or program 203 may prompt the user to enter alert reporter information (e.g., name, e-mail address, telephone number, address, emergency contact information, medical contact information, and geographic location), alert information, and alert data. The mobile application or program 203 may then communicate with the host computer system 210 . When the server code 220 determines that the alert report is an update of an existing alert report, server code 220 then executes mobile alert monitoring code 224 . Mobile alert reporting code updates the alert report 232 , 234 , 236 in the alert report database 230 and the alert report map 240 .
[0033] The host computer system 210 may also store an alert report database 230 where the database includes alert reporting information 232 , alert information 234 , and alert data 236 of the alert reports created. The host computer system 210 may also store an alert report map 240 where the alert report database 230 is used to plot alert reports on a map based on the geographic information provided in the alert report.
[0034] Although the illustrated embodiment of the mobile alert reporting and monitoring system 200 includes the code 222 and 224 for performing all of the functions or processes, other embodiments of the system 200 may include code for performing only one or more of these functions in combination with the server 220 . Although the code 222 and 224 is illustrated as discrete elements, these elements may not necessarily be executed as separate, discrete processes, procedures, or functions within the mobile alert reporting and monitoring system 200 . The mobile alert reporting and monitoring system 200 may include other code and other types of data to facilitate other processes, procedures, functions and features described herein. The mobile alert reporting and monitoring system 200 may include, for example, code that allows integration or linking with other online digital media (e.g., embedding YouTube® videos) and/or with online social networking websites (e.g., Facebook®) to share alert reports with other users.
[0035] Referring to FIG. 3 , one system and method for mobile alert reporting and monitoring involves creation of an alert report 330 . A user application or program 320 installed on the user computer 302 executes a create alert report process 324 that prompts the user via the user interface to provide alert reporter information 332 and alert information 334 and an capture alert data process 325 that prompts the user via the user interface to capture alert data 336 . The create alert report process 324 prompts a screen on the user computer 302 that allows the user to enter the alert reporter information 332 and alert information 334 . Then the user application or program 320 executes the capture alert data process 325 that prompts a screen on the user computer 302 that allows the user to capture alert data 336 associated with the alert report 330 . The user application or program 320 then sends the alert report 330 with the associated alert reporter information 332 , alert information 334 , and alert data 336 to the host computer system 110 , 210 . The alert report 330 can be accessed on the host computer system 110 , 210 by any user with access via a user application or program 320 .
[0036] Referring to FIG. 4 , another system and method for mobile alert reporting and monitoring involves enabling other users to monitor and contribute to an alert report 430 . A user application or program 420 installed on the user computer 402 executes a select existing alert report process 421 that prompts the alert report map 240 created in the host computer system 110 , 210 to be accessed by the user computer via user application or program. The select existing alert report process 421 prompts a screen that shows the alert report map 240 on the user computer 402 . The alert report map 240 shows existing alert reports plotted according to geographic location information and the user can select an alert report 430 on the alert report map 240 . Selecting an alert report on the alert report map 240 allows the user to access the alert report database and prompts a screen with the existing alert reporter information 432 , alert information 434 , and alert data 436 .
[0037] Selecting an alert report on the alert report map 240 executes an update alert report process 441 that prompts the user via the user interface to provide alert reporter information 452 and alert information 454 and a capture new alert data process 442 that prompts the user via the user interface to capture alert data 456 . The update alert report process 441 prompts a screen on the user computer 402 that allows the user to enter the alert reporter information 452 and alert information 454 . The user application or program 420 executes the capture alert data process 442 that prompts a screen on the user computer 402 that allows the user to capture alert data 456 associated with the alert report 430 . The user application or program 420 then sends the updated alert report 450 with the updated alert reporter information 452 , updated alert information 454 , and updated alert data 456 to the host computer system 110 , 210 . The alert report 450 can be accessed on the host computer system 110 , 210 by any user with access via a user application or program 420 .
[0038] FIGS. 5A-5C show screen shots of one example of home screens of user application or programs generated by software code and displayed on a user computer system. The user application home screen shown in FIG. 5A allows a user to report an incident with alert reporter information. When the user selects the report incident icon on the home screen, a create alert screen is displayed as shown in FIG. 5B . The create alert screen allows a user to choose between different crimes and incidents that may be occurring, for example, by selecting an incident icon. When the incident is selected, the type of incident is automatically included in the alert information and a new alert report may be automatically generated and sent. The new alert report contains alert reporter information (e.g., pre-entered into the user application) and the alert information (e.g., the type of incident associated with the selected incident icon).
[0039] After the user selects the type of incident, the capture alert data screen is displayed as shown in FIG. 5C . The capture alert screen allows a user to enter in descriptive alert information and begin to capture and/or upload alert data associated with the alert report. The user may activate the buttons on the screen to upload different types of alert data to the alert report database to be associated with the alert report.
[0040] FIG. 6A shows a screen shot of one example of an alert report creation page. The alert report creation page may provide different incidents and allows the user to choose between different incidents and crimes. After selecting an incident, the next screen is shown in FIG. 6B . FIG. 6B shows a screen that allows a user to enter in descriptive alert information and begin to capture alert data associated with the alert report.
[0041] FIG. 7A shows a screen shot of one example of an alert report map screen for identifying current alert reports in the nearby geographic location. The current alert reports allow access to alert reporter information, alert information, and access to alert data so the user can view the data on their computer system. FIG. 7B shows a screen that allows a user to update descriptive alert information and begin to capture new alert data associated with the monitored alert report.
[0042] Accordingly, the mobile reporting systems and methods described herein may be used to allow users to create alerts and to update those alerts. The mobile reporting systems and methods advantageously allow users at remote geographic locations to identify other alerts and to monitor and/or update those alerts despite the geographic separation.
[0043] Embodiments of the methods described above may be implemented as software or a computer program product for use with a processing system or computer. Such implementation may include, without limitation, a series of computer instructions that embody all or part of the functionality described herein. The series of computer instructions may be stored in any tangible machine-readable medium, such as semiconductor, magnetic, optical or other memory devices, and may be transmitted using any communications technology, such as optical, infrared, microwave, or other transmission technologies. Such a computer program product may be distributed as a removable machine-readable medium (e.g., a diskette, CD-ROM), preloaded with a computer system (e.g., on system ROM or fixed disk), or distributed from a server or electronic bulletin board over the network (e.g., the Internet or World Wide Web). Alternative embodiments of the invention may be implemented as pre-programmed hardware elements or as a combination of hardware, software and/or firmware.
[0044] Those skilled in the art will recognize that this is one possible implementation of the functionality described herein. A mobile reporting system may also include other processes, procedures or functions in addition to or in place of the processes, procedures or functions described herein. These or process, procedures or functions may be executed by a processor on one computer or may be executed by processors on separate computers. The data may include other types of data in addition to or in place of the data described herein.
[0045] While the principles of the invention have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments show and described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the following claims. | Computerized systems and methods may be used to enable users to report crimes, safety hazards or other perceived problems to the appropriate authorities via an alert. Such alerts may be communicated to the authorities through any suitable communication method such as, for example, phone calls, email and/or SMS text messages. In some example embodiments, the reporting system includes a computing device including, but not limited to, a mobile smartphone, tablet device, laptop computer, or desktop computer programmed with a software application. | 7 |
The present invention relates to novel thermoplastic elastomers having excellent stress-strain properties, low tensile set, high melting temperatures and/or excellent strength/toughness characteristics as well as superior flexibility which are especially suitable for molding and extrusion applications. Specifically, novel polyetherimide esters having the above-mentioned properties have been prepared from one or more diols, one or more dicarboxylic acids and, most importantly, one or more high molecular weight polyoxyalkylene diimide diacids.
Polyether ester imides are well known having been described in numerous publications and patents including for example, Honore et al, "Synthesis and Study of Various Reactive Oligmers and of Poly(ester-imide-ether)s", European Polymer Journal Vol. 16, pp. 909-916, Oct. 12, 1979; and in Kluiber et al, U.S. Pat. No. 3,274,159 and Wolfe Jr., U.S. Pat. Nos. 4,371,692 and 4,371,693, respectively. However, none of the prior art references teach or suggest the novel poly(etherimide ester) compositions of the present invention. Furthermore, none of these references provide polyetherimide ester resins having the excellent physical properties, including high melting point and excellent flexibility, as mentioned above, combined with the rapid crystallization rate and excellent moldability characteristics of the novel polyetherimide esters of the present invention.
Specifically, applicants have now found a novel class of poly(etherimide ester) elastomers which are particularly suited for molding and/or extrusion applications and which are characterized as having one or more of the following enhanced properties: stress-strain resistance, toughness/strength, and tensile set at low flexural modulus combined with rapid crystallization rates and excellent moldability as demonstrated by short cycle times and good mold releasability, respectively.
The novel poly(etherimide esters) of the present invention may be either random or block and are prepared by conventional processes from (a) one or more diols, (b) one or more dicarboxylic acids and (c) one or more polyoxyalkylene diimide diacids. Preferred compositions encompassed by the present invention may be prepared from (a) one or more C 2 -C 15 aliphatic and/or cycloaliphatic diols, (b) one or more C 4 -C 16 aliphatic, cycloaliphatic and/or aromatic dicarboxylic acids or ester derivatives thereof and (c) one or more polyoxyalkylene diimide diacids. The amount of polyoxyalkylene diimide diacid employed is generally dependent upon the desired properties of the resultant polyetherimide ester. In general, the weight ratio of polyoxyalkylene diimide diacid (c) to dicarboxylic acid (b) is from about 0.25 to 2.0, preferably from about 0.4 to about 1.4. Finally, the compositions may contain and preferably do contain additional stabilizers for even greater stabilization and low temperature impact strength.
Suitable diols (a) for use in preparing the compositions of the present invention include saturated and unsaturated aliphatic and cycloaliphatic dihydroxy compounds as well as aromatic dihydroxy compounds. These diols are preferably of a low molecular weight, i.e. having a molecular weight of about 250 or less. When used herein, the term "diols" and "low molecular weight diols" should be construed to include equivalent ester forming derivatives thereof, provided, however, that the molecular weight requirement pertains to the diol only and not to its derivatives. Exemplary of ester forming derivatives there may be given the acetates of the diols as well as for example ethylene oxide or ethylene carbonate for ethylene glycol.
Preferred saturated and unsaturated aliphatic and cycloaliphatic diols are those having from about 2 to 15 carbon atoms. Exemplary of these diols there may be given ethyleneglycol, propanediol, butanediol, pentanediol, 2-methyl propanediol, 2,2-dimethyl propanediol, hexanediol, decanediol, 1,2-, 1,3- and 1,4-dihydroxy cyclohexane; 1,2-, 1,3- and 1,4-cyclohexane dimethanol; butene diol; hexene diol, etc. Especially preferred are 1,4-butanediol and mixtures thereof with hexanediol or butenediol, most preferably 1,4-butanediol.
Aromatic diols suitable for use in the practice of the present invention are generally those having from 6 to about 15 carbon atoms. Included among the aromatic dihydroxy compounds are resorcinol; hydroquinone; 1,5-dihydroxy napthalene; 4,4'-dihydroxy diphenyl; bis(p-hydroxy phenyl)methane and bis(p-hydroxy phenyl) 2,2-propane.
Especially preferred diols are the saturated aliphatic diols, mixtures thereof and mixtures of a saturated diol(s) with an unsaturated diol(s), wherein each diol contains from 2 to about 8 carbon atoms. Where more than one diol is employed, it is preferred that at least about 60 mole %, based on the total diol content, be the same diol, most preferably at least 80 mole %. As mentioned above, the preferred compositions are those in which 1,4-butanediol is present in a predominant amount, most preferably when 1,4-butanediol is the only diol.
Dicarboxylic acids (b) which are suitable for use in the practice of the present invention are aliphatic, cycloaliphatic, and/or aromatic dicarboxylic acids. These acids are preferably of a low molecular weight, i.e., having a molecular weight of less than about 300; however, higher molecular weight dicarboxylic acids, especially dimer acids, may also be used. The term "dicarboxylic acids" as used herein, includes equivalents of dicarboxylic acids having two functional carboxyl groups which perform substantially like dicarboxylic acids in reaction with glycols and diols in forming polyester polymers. These equivalents include esters and ester-forming derivatives, such as acid halides and anhydrides. The molecular weight preference, mentioned above, pertains to the acid and not to its equivalent ester or ester-forming derivative. Thus, an ester of a dicarboxylic acid having a molecular weight greater than 300 or an acid equivalent of a dicarboxylic acid having a molecular weight greater than 300 are included provided the acid has a molecular weight below about 300. Additionally, the dicarboxylic acids may contain any substituent group(s) or combinations which do not substantially interfere with the polymer formation and use of the polymer of this invention.
Aliphatic dicarboxylic acids, as the term is used herein, refers to carboxylic acids having two carboxyl groups each of which is attached to a saturated carbon atom. If the carbon atom to which the carboxyl group is attached is saturated and is in a ring, the acid is cycloaliphatic.
Aromatic dicarboxylic acids, as the term is used herein, are dicarboxylic acids having two carboxyl groups each of which is attached to a carbon atom in an isolated or fused benzene ring system. It is not necessary that both functional carboxyl groups be attached to the same aromatic ring and where more than one ring is present, they can be joined by aliphatic or aromatic divalent radicals or divalent radicals such as --O-- or --SO 2 --.
Representative aliphatic and cycloaliphatic acids which can be used for this invention are sebacic acid, 1,2-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, adipic acid, glutaric acid, succinic acid, oxalic acid, azelaic acid, diethylmalonic acid, allylmalonic acid, dimer acid, 4-cyclohexene-1,2-dicarboxylic acid, 2-ethylsuberic acid, tetramethylsuccinic acid, cyclopentanedicarboxylic acid, decahydro-1,5-naphthalene dicarboxylic acid, 4,4'-bicyclohexyl dicarboxylic acid, decahydro-2,6-naphthalene dicarboxylic acid, 4,4 methylenebis(cyclohexane carboxylic acid), 3,4-furan dicarboxylic acid, and 1,1-cyclobutane dicarboxylic acid. Preferred aliphatic acids are cyclohexane dicarboxylic acids, sebacic acid, dimer acid, glutaric acid, azelaic acid and adipic acid.
Representative aromatic dicarboxylic acids which can be used include terephthalic, phthalic and isophthalic acids, bi-benzoic acid, substituted dicarboxy compounds with two benzene nuclei such as bis(p-carboxyphenyl) methane, oxybis(benzoic acid), ethylene-1,2-bis-(p-oxybenzoic acid), 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, phenanthrene dicarboxylic acid, anthracene dicarboxylic acid, 4,4'-sulfonyl dibenzoic acid, and halo and C 1 -C 12 alkyl, alkoxy, and aryl ring substitution derivatives thereof. Hydroxy acids such as p(β-hydroxyethoxy)benzoic acid can also be used provided an aromatic dicarboxylic acid is also present.
Preferred dicarboxylic acids for the preparation of the polyetherimide esters of the present invention are the aromatic dicarboxylic acids, mixtures thereof and mixtures of one or more dicarboxylic acid with an aliphatic and/or cycloaliphatic dicarboxylic acid, most preferably the aromatic dicarboxylic acids. Among the aromatic acids, those with 8-16 carbon atoms are preferred, particularly the benzene dicarboxylic acids, i.e., phthalic, terephthalic and isophthalic acids and their dimethyl derivatives. Especially preferred is dimethyl terephthalate.
Finally, where mixtures of dicarboxylic acids are employed in the practice of the present invention, it is preferred that at least about 60 mole %, preferably at least about 80 mole %, based on 100 mole % of dicarboxylic acid (b) be of the same dicarboxylic acid or ester derivative thereof. As mentioned above, the preferred compositions are those in which dimethylterephthalate is the predominant dicarboxylic acid, most preferably when dimethylterephthalate is the only dicarboxylic acid.
Polyoxyalkylene diimide diacids (c) suitable for use herein are high molecular weight diimide diacids wherein the average molecular weight is greater than about 700, most preferably greater than about 900. They may be prepared by the imidization reaction of one or more tricarboxylic acid compounds containing two vicinal carboxyl groups or an anhydride group and an additional carboxyl group which must be esterifiable and preferably is nonimidizable with a high molecular weight polyoxylalkylene diamine. These polyoxyalkylene diimide diacids and processes for their preparation are more fully disclosed in applicant's copending, U.S. patent application Ser. No. 665,192, filed Oct. 26, 1984 entitled "High Molecular Weight Diimide Diacids and Diimide Diesters of Tricarboxylic Anhydrides", incorporated herein by reference.
In general, the polyoxyalkylene diimide diacids useful herein may be characterized by the following formula: ##STR1## wherein each R is independently a trivalent organic radical, preferably a C 2 to C 20 aliphatic, aromatic or cycloaliphatic trivalent organic radical; each R' is independently hydrogen or a monovalent organic radical preferably selected from the group consisting of C 1 to C 6 aliphatic and cycloaliphatic radicals and C 6 to C 12 aromatic radicals, e.g. benzyl, most preferably hydrogen; and G is the radical remaining after the removal of the terminal (or as nearly terminal as possible) hydroxy groups of a long chain ether glycol having an average molecular weight of from about 600 to about 12000, preferably from about 900 to about 4000, and a carbon-to-oxygen ratio of from about 1.8 to about 4.3.
Representative long chain ether glycols from which the polyoxyalkylene diamine is prepared include poly(ethylene ether)glycol; poly(propylene ether)glycol; poly(tetramethylene ether)glycol; random or block copolymers of ethylene oxide and propylene oxide, including propylene oxide terminated poly(ethylene ether)glycol; and random or block copolymers of tetrahydrofuran with minor amounts of a second monomer such as methyl tetrahydrofuran (used in proportion such that the carbon-to-oxygen mole ratio in the glycol does not exceed about 4.3). Especially preferred poly(alkylene ether)glycols are poly(propylene ether) glycol and poly(ethylene ether)glycols end capped with poly(propylene ether)glycol and/or propylene oxide.
In general, the polyoxyalkylene diamines useful within the scope of the present invention will have an average molecular weight of from about 600 to 12000, preferably from about 900 to about 4000.
The tricarboxylic component may be almost any carboxylic acid anhydride containing an additional carboxylic group or the corresponding acid thereof containing two imide-forming vicinal carboxyl groups in lieu of the anhydride group. Mixtures thereof are also suitable. The additional carboxylic group must be esterifiable and preferably is substantially nonimidizable.
Further, while trimellitic anhydride is preferred as the tricarboxylic component, any of a number of suitable tricarboxylic acid constituents will occur to those skilled in the art including 2,6,7 naphthalene tricarboxylic anhydride; 3,3',4 diphenyl tricarboxylic anhydride; 3,3',4 benzophenone tricarboxylic anhydride; 1,3,4 cyclopentane tricarboxylic anhydride; 2,2',3 diphenyl tricarboxylic anhydride; diphenyl sulfone - 3,3',4 tricarboxylic anhydride, ethylene tricarboxylic anhydride; 1,2,5 napthalene tricarboxylic anhydride; 1,2,4 butane tricarboxylic anhydride; diphenyl isopropylidene 3,3',4 tricarboxylic anhydride; 3,4 dicarboxyphenyl 3'-carboxylphenyl ether anhydride; 1,3,4 cyclohexane tricarboxylic anhydride; etc. These tricarboxylic acid materials can be characterized by the following formula: ##STR2## where R is a trivalent organic radical, preferably a C 2 to C 20 aliphatic, aromatic, or cycloaliphatic trivalent organic radical and R' is preferably hydrogen or a monovalent organic radical preferably selected from the group consisting of C 1 to C 6 aliphatic and/or cycloaliphatic radicals and C 6 to C 12 aromatic radicals, e.g. benzy; most preferably hydrogen.
Briefly, these polyoxyalkylene diimide diacids may be prepared by known imidization reactions including melt synthesis or by synthesizing in a solvent system. Such reactions will generally occur at temperatures of from 100° C. to 300° C., preferably at from about 150° C. to about 250° C. while drawing off water or in a solvent system at the reflux temperature of the solvent or azeotropic (solvent) mixture.
Although the weight ratio of the above ingredients is not critical, it is preferred that the diol be present in at least a molar equivalent amount, preferably a molar excess, most preferably at least 150 mole % based on the moles of dicarboxylic acid (b) and polyoxyalkylene diimide diacid (c) combined. Such molar excess of diol will allow for optimal yields, based on the amount of acids, while accounting for the loss of diol during esterification/condensation.
Further, while the weight ratio of dicarboxylic acid (b) to polyoxyalkylene diimide diacid (c) is not critical to form the novel polyetherimide esters of the present invention, preferred compositions are those in which the weight ratio of the polyoxyalkylene diimide diacid (c) to dicarboxylic acid (b) is from about 0.25 to about 2, preferably from about 0.4 to about 1.4. The actual weight ratio employed will be dependent upon the specific polyoxyalkylene diimide diacid used and more importantly, the desired physical and chemical properties of the resultant polyetherimide ester. In general, the lower the ratio of polyoxyalkylene diimide diester to dicarboxylic acid the better the strength, crystallization and heat distortion properties of the polymer. Alternatively, the higher the ratio, the better the flexibility, tensile set and low temperature impact characteristics.
In its preferred embodiments, the compositions of the present invention will comprise the reaction product of dimethylterephthalate, optimally with up to 40 mole % of another dicarboxylic acid; 1,4-butanediol, optionally with up to 40 mole % of another saturated or unsaturated aliphatic and/or cycloaliphatic diol; and a polyoxyalkylene diimide diacid prepared from a polyoxyalkylene dimine of molecular weight of from about 600 to about 12000, preferably from about 900 to about 4000, and trimellitic anhydride. In its most preferred embodiments, the diol will be 100 mole % 1,4-butanediol and the dicarboxylic acid 100 mole % dimethylterephthalate.
The novel polyetherimide esters described herein may be prepared by conventional esterification/condensation reactions for the production of polyesters. Exemplary of the processes that may be practiced are as set forth in, for example, U.S. Pat. Nos. 3,023,192; 3,763,109; 3,651,014; 3,663,653 and 3,801,547, herein incorporated by reference. Additionally, these compositions may be prepared by such processes and other known processes to effect random copolymers, block copolymers or hybrids thereof wherein both random and block units are present.
It is customary and preferred to utilize a catalyst in the process for the production of the polyetherimide esters of the present invention. In general, any of the known ester-interchange and polycondensation catalysts may be used. Although two separate catalysts or catalyst systems may be used, one for ester interchange and one for polycondensation, it is preferred, where appropriate, to use one catalyst or catalyst system for both. In those instances where two separate catalysts are used, it is preferred and advantageous to render the ester-interchange catalyst ineffective following the completion of the precondensation reaction by means of known catalyst inhibitors or quenchers, in particular, phosphorus compounds such as phosphoric acid, phosphenic acid, phosphonic acid and the alkyl or aryl esters or salts thereof, in order to increase the thermal stability of the resultant polymer.
Exemplary of the suitable known catalysts there may be given the acetates, carboxylates, hydroxides, oxides, alcoholates or organic complex compounds of zinc, manganese, antimony, cobalt, lead, calcium and the alkali metals insofar as these compounds are soluble in the reaction mixture. Specific examples include, zinc acetate, calcium acetate and combinations thereof with antimony tri-oxide and the like. These catalysts as well as additional useful catalysts are described in U.S. Pat. Nos. 2,465,319; 2,534,028; 2,850,483; 2,892,815; 2,937,160; 2,998,412; 3,047,539; 3,110,693 and 3,385,830, among others, incorporated herein by reference.
Where the reactants and reactions allow, it is preferred to use the titanium catalysts including the inorganic and organic titanium containing catalysts, such as those described in, for example, Nos. 2,720,502; 2,727,881; 2,729,619; 2,822,348; 2,906,737; 3,047,515; 3,056,817; 3,056,818; and 3,075,952 among others, incorporated herein by reference. Especially preferred are the organic titanates such as tetra-butyl titanate, tetra-isopropyl titanate and tetra-octyl titanate and the complex titanates derived from alkali or alkaline earth metal alkoxides and titanate esters, most preferably the organic titanates. These too may be used alone or in combination with other catalysts such as for example, zinc acetate, manganese acetate or antimony trioxide, and/or with a catalyst quencher as described above.
Although the novel polyetherimide ester of the present invention possess many desirable properties, it is preferred to stabilize certain of the compositions to heat, oxidation, radiation by UV light and the like. This can be accomplished by incorporating stabilizer materials into the compositions either during production or while in a hot melt stage following polymerization. The particular stabilizers useful herein are any of those known in the art which are suitable for polyetherimide esters.
Satisfactory stabilizers comprise phenols and their derivatives, amines and their derivatives, compounds containing both hydroxyl and amine groups, hydroxyazines, oximes, polymeric phenolic esters and salts of multivalent metals in which the metal is in its lower valence state.
Representative phenol derivatives useful as stabilizers include 3,5-di-tert-butyl-4-hydroxy hydrocinnamic triester with 1,3,5-tris-(2-hydroxyethyl)-s-triazine-2,4,6-(1H,3H,5H)trione; 4,4'-bis(2,6-ditertiary-butylphenol); 1,3,5-trimethyl-2,4,6-tris(3,5-ditertiary-butyl-4-hydroxybenzyl)benzene and 4,4'-butylidene-bis(6-tertiary-butyl-m-cresol). Various inorganic metal salts or hydroxides can be used as well as organic complexes such as nickel dibutyl dithiocarbonate, manganous salicylate and copper 3-phenyl-salicylate. Typical amine stabilizers include N,N'-bis(betanaphthyl)-p-phenylene diamine; N,N'-bis(1-methylheptyl) -p-phenylene diamine and either phenyl-betanaphthyl amine or its reaction products with aldehydes. Mixtures of hindered phenols with esters of thiodipropionic acid, mercaptides and phosphite esters are particularly useful. Additional stabilization to ultraviolet light can be obtained by compounding with various UV absorbers such as substituted benzophenones and/or benzotriazoles.
Optionally, it may be desirable to add a minor amount, up to about 20 mole %, preferably up to about 10 mole %, based on the moles of the polyoxyalkylene diimide diacid, of a tricarboxylic component to the reaction mixture. While higher amounts of the tricarboxylic component may be used, this has the disadvantage of reducing some of the beneficial properties of the present polymers. Suitable tricarboxylic components are the same as identified above for the preparation of the polyoxyalkylene diimide diacid. While it is preferred that the additional tricarboxylic component be the same as used in the preparation of the polyoxyalkylene diimide diacid, it is not necessary. The addition of the tricarboxylic acid component will have the added benefit of picking up and reacting with any residual, unreacted amine groups and, consequently, aiding in the viscosity build of the polymer itself.
Further, the properties of these polyesters can be modified by incorporation of various conventional inorganic fillers such as carbon black, silica gel, alumina, clays and chopped fiberglass. These may be incorporated in amounts up to 50% by weight, preferably up to about 30% by weight. In general, these additives have the effect of increasing the modulus of the material at various elongations.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples are presented as illustrative of the present invention and are not to be construed as limiting thereof.
Physical properties were determined according the proper ASTM methods as follows:
______________________________________Flexural Modulus ASTM D 790Tensile Strength ASTM D 638Tensile Elongation ASTM D 638Shore D Hardness ASTM D 2240Tensile Set ASTM D 412______________________________________
In general, all compositions were prepared by placing all reactants in the reaction vessel and heating to 180° C. After the theoretical amount of methanol was removed, the pot temperature was increased to about 250° C. and a vacuum applied (<1 mm Hg) until the desired viscosity polymer was obtained. All reactions, unless otherwise specified were catalyzed with tetraoctyl titanate catalyst.
Diimide Diacid A
A polyoxyalkylene diimide diacid was prepared by the imidization of trimellitic anhydride with Texaco Chemical Company's Jeffamine® D2000, a polypropylene ether diamine, average molecular weight 2000.
Diimide Diacid B
A second polyoxyalkylene diimide diacid was prepared by the imidization of trimellitic anhydride with Texaco Chemical Company's Jeffamine ED-900, a predominately polyethylene oxide backbone, copoly(ethylene oxide-propylene oxide) diamine, average molecular weight 900.
Diimide Diacid C
A third polyoxyalkylene diimide diacid was prepared by the imidization of trimellitic anhydride with Texaco Chemical Company's Jeffamine ED-2001, a predominately polyethylene oxide backbone, copoly(ethylene oxide-propylene oxide)diamine, average molecular weight 2000.
EXAMPLES 1-9
Two series of compositions were prepared, one with Diimide Diacid A and the other with Diimide Diacid B at various weight ratios to dicarboxylic acid. The compositions were as presented in Table 1. All reactants are in parts by weight. Additionally, each composition contained about 3% by weight based on the diimide diacid of a thermal stabilizer.
The elastomeric polymers of these examples had excellent physical properties and had surprisingly superior processability and moldability characteristics.
TABLE 1__________________________________________________________________________ 1 2 3 4 5 6 7 8 9__________________________________________________________________________COMPOSITION1,4-Butanediol 36 33 32 30 27 36 33 32 30Dimethyl terephthalate 46 42 40 38 34 46 42 40 38Diimide Diacid A 18 25 28 32 39 -- -- -- --Diimide Diacid B -- -- -- -- -- 18 25 28 32Wt. Ratio of Diimide Diacid/DMT .4 .6 .7 .85 1.15 .4 .6 .7 .85Trimelletic Anhydride 7.1 7.3 7.2 7.4 6.8 3.2 3.3 3.2 3.3mole % based onDiimide DiacidPROPERTIESMelting Point, °C. 215 214 210 203 201 208 196 194 190Flexural Modulus, psi × 10.sup.3 63 32 24 16 14.5 52 33 25 20Tensile Set, % 36 28 25 19 -- 31 30 21 20__________________________________________________________________________
EXAMPLES 10-22
Several additional compositions within the scope of the present invention were prepared demonstrating various different embodiments hereof. For example, Example 10 demonstrates a composition derived from a mixture of dimethylterephthalate and isophthalic acid and Examples 11, 15, 17 and 21 demonstrates the use of dimer acid (Hystrene® 3695--Witco Chemical Corporation).
Finally, Example 16 demonstrate the use of ethylene glycol as the diol component (this reaction used antimony oxide and zinc acetates as catalysts with a phosphite catalyst quencher). Only those examples as indicated contained a thermal stabilizer. The composition and physical properties of these examples were as set forth in Table 2. All amounts are in parts by weight unless otherwise specified. A comparison of Example 6, above, with Example 12 demonstrates the improved properties obtained by use of stabilizer and excess trimellitic anhydride.
TABLE 2__________________________________________________________________________ 10 11 12 13 14 15 16 17 18 19 20 21 22__________________________________________________________________________COMPOSITION1,4-Butanediol 21 30 36 30 30 32 -- 31 27 21 35 32 30Ethylene glycol -- -- -- -- -- -- 22 -- -- -- -- -- --Dimethyl 28 36 46 40 40 38 35 37 32 35 46 38 38terephthalateIsophthalic Acid 7 -- -- -- -- -- -- -- -- -- -- -- --Dimer Acid -- 7 -- -- -- 10.5 -- 5 -- -- -- 5 --Diimide Diacid A 44 -- -- -- -- -- 44 27 41 44 19 25 32Diimide Diacid B -- 27 18 -- -- 20 -- -- -- -- -- -- --Diimide Diacid C -- -- -- 30 30 -- -- -- -- -- -- -- --Thermal Stabilizer.sup.a 5 -- -- -- -- -- 5 -- 4.3 5 5 5 5Wt. Ratio of 1.27 .74 .4 .77 .77 .52 1.27 .75 1.30 1.25 .41 .65 .82DiimideDiacid/DicarboxylicAcid (excludingDimer Acid)PROPERTIESMelting Point, °C. 162 191 210 206 211 193 226 201 197 193 219 201 211Flexural Modulus, 4.9 19.2 45.2 24.6 22 -- 4.5 16.9 7.0 -- 49 18 22psi × 10.sup.3Tensile Strength 5.0 2.4 4.5 2.8 2.9 -- 3.5 2.4 6.7 -- -- -- --psi × 10.sup.3Tensile 1143 619 554 786 614 -- 143 334 881 -- -- -- --Elongation %Shore D Hardness 31 48 61 47 49 -- 30 48 37 -- -- -- --Tensile Set, % -- -- -- 25 -- -- -- -- -- -- -- -- --__________________________________________________________________________ .sup.a in wt. % based on amount of diimide diacid.
EXAMPLES 23-27
Additional compositions were prepared again further demonstrating the broad scope of the present invention wherein both stabilizer and additional trimellitic anhydride were added to the reaction mix. The compositions and the physical properties thereof were as shown in Example 3.
TABLE 3______________________________________ 23 24 25 26 27______________________________________COMPOSITION1,4-Butanediol 33 23 23 15 141,6-Hexanediol -- 7.5 -- 10 9Dimethyl terephthalate 39 46.5 -- 33 36Isophthalic Acid -- -- 36 7 --Azelaic Acid 9 -- -- -- --Diimide Diacid A 19 23 41 36 41Thermal stabilizer.sup.a 3.7 3 5.5 7 5.5Trimellitic Anhydride.sup.b 8.7 7.4 5 9 7.3PROPERTIESMelting Point 184 178 114 ND ND______________________________________ .sup.a See Table 2, note .sup.a .sup.b in mole % based on number of moles of Diimide Diacid
Obviously, other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments of the invention described which are within the full intended scope as defined by the appended claims. | Novel polyetherimide esters are prepared from diols, dicarboxylic acids and polyoxyalkylene diimide diacids. These compositions have many excellent properties which make them particularly useful for extrusion and molding applications. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a zoned heating and air conditioning system, and especially to an air handling system having special dampers used in connection with separate thermostats to heat or air condition one zone while disabling another.
In the past, there have been a number of systems suggested for controlling the temperature in different portions of a building with different thermostats or for disabling one portion of a building when that portion of the building is not in use. Typically such systems use two air conditioning compressors along with two duct systems, one controlling the temperature in the bedroom portion of a house and the other controlling the temperature in the living room, dining room and kitchen portion of a house. In this way the bedroom portion can be heated or cooled in the evenings with the temperature adjusted during the daytime to reduce the energy usage in that portion of the house. Similarly, the remainder of the house can be adjusted between nighttime and daytime, and thereby reduce the total energy utilized. It has also been suggested to open or close air grills to disable one or more rooms for long periods of time so that energy is not wasted heating or cooling an unused room or portion of a house. One of the disadvantages of many prior systems is that they require two separate air conditioning systems, or alternatively, require expensive electrical systems for working different portions of the building. The present system overcomes some of the disadvantages of prior systems by providing a single heating and cooling system of a substantially reduced size for a building while maintaining the comfort level of those portions of the building in use. For instance, the heating and air conditioning system can be reduced in size to provide only half as much energy as required for the full building. The duct system would be similar in cost and complexity to an existing duct system with the building set up to operate the heating and air conditioning system only in that portion of the building in use at any particular time, and to shift from one system to the other prior to using the other part of the building. The present system also provides for inexpensive dampers electronically controlled to reduce the cost of the system to well below the cost of a heating and air conditioning system for the entire building.
Typical prior art U.S. patents can be seen in the Perkins U.S. Pat. No. 3,994,335, for a multizone air conditioning system using a thermostatically controlled valve system in the air ducts to control the amount of hot and cold air delivered to each zone of the building. Similarly, the Marshall, et al., U.S. Pat. No. 3,368,752, uses a spool valve to control cool air and the mix of cool and hot air in a dual duct air conditioning system with seasonal changeover assembly. Prior air conditioning grill dampers and air duct control systems can be seen in the U.S. patent to Waeldner, U.S. Pat. No. 3,604,625, on an air flow mixing device for air conditioning systems using a solenoid controlled system of interconnected valve members, and in the Downes, Jr., U.S. Pat. No. 4,418,719, for an air control apparatus using a drive motor to shift vanes. The Marks, et al., U.S. Pat. No. 4,055,954, shows a damper actuator for ventilator systems in which a temperature expansion cylinder is used for controlling the damper. The Felter patent, U.S. Pat. No. 4,017,026, is for an automatic damper which has a temperature responsive element for pivoting semicircular vanes. The Maxson patent, U.S. Pat. No. 4,397,223, is an air distributor with automatically closing dampers and the Waterfill patent, U.S. Pat. No. 2,999,640, is an air conditioning mixing valve in which the air flowing past the pipe is aspirated to adjust the valve with a negative pressure in a shifting valve system.
In contrast to these prior patents, the present invention is directed towards a centrally controlled system which will operate dampers in combination with the controls to maintain the temperature in one zone of a building while shutting off another zone of a building and requiring a less expensive installation and a reduced use of energy in the building.
SUMMARY OF THE INVENTION
The present invention relates to a zoned heating and air conditioning system having an air handling system with an air blower connected to an air duct system in a building. At least two thermostats are positioned in different portions of the building and interconnected for actuation of only one zone of a building at one time. A plurality of dampers are positioned in the air duct system of the building with each damper being adapted to be opened and closed by gravity or air pressure, and each damper having a locking means for locking each damper in a closed position responsive to actuation by an electric switch. Each thermostat may be positioned to actuate one set of dampers with the operative thermostat actuating the inoperative thermostat's zone dampers. The dampers can be opened or closed by air pressure and can be opened or closed by gravity, but are locked in their closed position with a solenoid locking mechanism to block the flow of air to one zone of the building. Individual dampers can also be actuated by a simple electrical switch. Each damper may have a relay and a power supply for individually operating the solenoid with the locking mechanism with a low voltage system. The solenoids are used only for locking and may be spring loaded to reduce the amount of energy to operate the locks. The locks can be operated by using a larger power supply for the operation of the low voltage thermostat. Microswitches can be utilized to sense and activate or deactivate the solenoids only upon the damper being positioned in the proper location for locking.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will be apparent from the written description and the drawings in which:
FIG. 1 is a layout of a duct system for a two-zone house.
FIG. 2 shows a sectional view of a locking damper in accordance with the present invention locked in closed position;
FIG. 3 is a sectional view of a second locking damper;
FIG. 4 is a sectional view of another embodiment of a locking damper;
FIG. 5 is a sectional view of another embodiment of a locking damper;
FIG. 6 is a sectional view of another embodiment of a locking damper;
FIG. 7 is a sectional view of another embodiment of a locking damper;
FIG. 8 is a sectional view of another embodiment of the locking damper; and
FIG. 9 is an electrical schematic of a two-zoned system in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, a building has exterior walls 11 with a central air handling system 12 located in the middle of the building or any other location and includes a pair of bedrooms 13 and 14 along with a bathroom 15 located between the bedrooms. A living room 16 is adjacent to a kitchen 17. A first zoned ducting system 18 is connected from the air handling system 12 to the bedrooms 13 and 14 and bathroom 15. A second air handling duct system 20 is connected to the central air handling system 12 and has outlets in the kitchen 17 and living room 16, as well as a connection to the bathroom 15. Bathroom 15 also has a common duct outlet at 21 which allows the duct system 18 or 20 to both operate in the bathroom 15 and through damper 19.
FIGS. 2 through 7 show various embodiments of locking dampers, but each of the locking dampers has several features in common including being moved from an open to closed position by either gravity or by the force of the air flow and each can be left in a locked position to close off a duct or to close off one duct while opening a second one. The embodiment in FIG. 2 shows a duct 22 having a damper door 23 therein pivoted at 24 and pushed by the air against a damper stop 25. The damper in this case is closed by gravity and locked by a damper solenoid lock 26 (shown schematically but which may operate in accordance with FIG. 4) positioned in the control compartment between two dampers. Similarly, FIG. 3 has a damper 27 in a duct 28 pivoted on a pivot point 30 located in the duct and has a counterweight 31 on one end to counterbalance the damper door 27. A damper stop 32 catches one end of the door 27 when open while the solenoid lock 33 (shown schematically but which may operate in accordance with FIG. 4) locks the damper door 27 when the counterweight 31 swings the door 27 against the lock 33 when there is no air flowing. When the lock 33 is released, the air flow will force the door 27 against the damper stop 32 and hold the door open as long as air is flowing thereby. Turning to FIG. 4, additional detail is shown of a damper in a duct 34 having a damper door 35 pivoted on a hinge 36 from an open position where air can flow through the duct system to a closed position as shown in this view in which the damper door 35 has a microswitch 37 to actuate or tell the solenoid 38 that the door 35 is in position for locking. Switch 37 is always supplied with power and is wired to solenoid 38 so that when the door 35 opens, power is supplied to the solenoid by the switch 37 and this circuit is connected in parallel with the circuit supplying energy from the zone thermostats 90 and 91 of FIG. 9. The solenoid 38 has a plunger 40 which slides into position with a locking tip 41 to lock the damper door 35 in position to block the flow of air past the damper. Solenoid 38 has an adjustable frame 42 for the back portion of the plunger 43 and has a spring 44 mounted around the plunger 43 which holds the plunger 40 in a normally locked position.
FIG. 5 shows another locking damper door in an air handling duct 45 having a locking damper door 46 attached to a solenoid motor 47 with a hinge pin 48 through a locking arm 50. Solenoid 47 is actuated upon the microswitch 51 generating a signal to actuate the solenoid 47. A spring 49 is wrapped around the hinge pin 48 to slightly bias the door to leave a small opening for the passage of air when the door 46 is closed.
FIG. 6 shows another embodiment in which a duct 52 for the handling of air has a damper door 53 in its open position as shown connecting by a hinge pin 54 to a locking arm 55 which is spring actuated by a spring 56 pinned at 57. The locking arm 55 has an aperture 58 therein and is aligned with the plunger 60 of the solenoid 61 attached to a solenoid support bracket 62 when the door is closed. Solenoid 61 is actuated when the damper door 53 bumps against the microswitch 63 which is thereby actuated to drive the plunger arm 60 through the aperture 58 to lock the solenoid door in place. The damper door 53 is held in an open position by the spring 56 and air flow until the reduced flow of air allows the door 53 to fall to the closed position where the spring 56 helps close door 53 to hit the microswitch 63.
Similarly, the embodiment shown in FIG. 7 in the air duct 64 has a damper door 65 hinged with a hinge 66 which can swing from an open duct position to a closed duct position, where it hits a microswitch 67 which actuates a solenoid 68 attached to a solenoid bracket 70. The swinging of the gate 65 engages a bifurcated leg 71 in a locking arm 72 pivoting at (x) which is spring loaded by spring 73 pinned to the ducts at 74 to align an aperture 75 on the arm 72 with a solenoid 68 to lock the solenoid plunger in the aperture 75 of the arm 72 when the damper door 65 abuts the microswitch 67. The advantages of these damper control systems is that the dampers are controlled either by gravity or the flow of air and are locked in position using a minimum of electrical energy and thus may use a low voltage system operated by the same voltage to drive the thermostats to reduce the cost and complexity of the electrical control system.
Turning to FIG. 8, a damper door is mounted in a dividing duct 103 and allows for the air to enter from the duct 104 through the duct 105 into the dividing ducts 106 and 107. The Y-duct 103 has the damper door 108 pivoted on the bottom of the bifurcated portion. The damper door is connected between solenoids 109 and 110, through a linkage 112 to position the door for solenoid 111 to extend the solenoid plunger through the opening 113, to lock the damper door 108 directly centered in the duct 105 between the ducts 106 and 107. The air in duct 105 is thus evenly divided between ducts 106 and 107 when the duct is locked in position. Actuating the solenoids 109 and 110 and releasing the solenoid 111 can move the damper door 108 to the right or to the left to block off either duct 106 or 107. The air pressure entering the duct 105 will maintain the damper door 108 in the closed position. Alternatively the door can be locked with latching solenoids 109 and 110. It should also be clear in this embodiment that the air can be received from the dividing ducts 106 and 107 into the duct 105, as desired, without departing from the spirit and scope of the invention.
FIG. 9 is a schematic diagram of a two-thermostat, two zone building heating and cooling system having a four-pole relay 80 and a four-pole relay 81. Relay 81 is connected through a time-delay circuit 82 to the fan connection of the thermostat 84, while the relay 80 is connected through a time delay circuit 83 through a fan connection of a thermostat 85. Thermostat 84 and thermostat 85 are connected through the relays 80 and 81 to the air handling system 86 which may include a heat pump or a heating furnace and air conditioning combined along with the air blower. The fan lines 92 and 96 from the thermostats 84 and 85 to the air handlers are connected through damper controls 90 and 91 in parallel to the relays 80 and 81 but in series with the time delay circuits 82 and 83. This allows the damper controls to lock the dampers after a predetermined time delay, when the circuit is actuated. The circuit is actuated by a voltage between the fan connection on the air handler unit 86 and the fan connection on either the thermostat 84 or the thermostat 85. The unit is designed so that only one thermostat can be connected to the air handler at one time. This thermostat 84 has air handling connection lines 92 which is connected to actuate the fan as well as lines 93 and 94 for actuating the heating and cooling, and a primary voltage line 95. The thermostat 85 has the fan line 96 as well as a cooling line 97 heating line 98 and a primary voltage line 100. The primary voltage line of the thermostat 84 is connected through the relay 80 and has one contact 101 closed or connected in the relay's normally closed position while the remaining contacts are oppositely connected to connect the thermostat 85 to the air handler 86 when the relay 80 is actuated disengaging the contact 101 and the thermostat 84 from the primary voltage source. Similarly, the thermostat 85 has a primary voltage source line 87 connected across a relay contact 102 which is a normally closed position while the remaining contacts of relay 81 are normally open so that actuation of the relay 81 will disengage the contact 102 but engage the remaining contacts for the lines 92, 93 and 94. In the normally closed position, contact 102 connects the voltage line from the air handler 86 to the thermostat 85. In operation, the air handler voltage is normally connected to both thermostats 84 and 85 until one is actuated, in which case its relay disengages the voltage to the other thermostat so that only one thermostat can be actuated at one time, and each thermostat can be actuated at different temperatures for controlling different portions of a building. Each thermostat's relay actuates the damper controls of the opposite thermostat's area of control to thereby close the dampers in the opposite thermostat's area, while one thermostat is in operation, so that the thermostats are controlling both sections of a building simultaneously at different temperatures. This handles a situation where one portion of a building has different temperature requirements from another. It also allows the thermostats to be manually set for turning portions of a building off and portions on during different times of the day or the year, and alternatively, the thermostats 84 and 85 can have commercially available timing thermostats for actuating the thermostats to an enabling position only at certain times of the day to thereby allow portions of the building to be turned on and off in accordance with the usage requirements of the portions of the building.
In the system shown in FIG. 1, This electrical circuit that can be used to control air handling in ducts 20 to the living room 16, the kitchen 17 and to the common bathroom 15 and ducts 18 to the bedrooms 13 and 14 and common bathroom 15 is located at the central air handling system 12. This system requires only the switching of one of a pair of dampers by one of the thermostats located in one of the bedrooms or one located in or near the living room. Thus, with the use of two automatic dampers actuated by either gravity or air flow and unlocked by small, low-voltage solenoids, a two-zone air handling system can be installed in a home or commercial building with two thermostats. A system in a residence or office like this allows a much smaller furnace and air conditioning compressor to be utilized, as well as smaller air handling system, and thus reduces the cost over the normal central heating-cooling system installation and substantially reduces the power requirement for the building.
Accordingly, the present invention is not to be construed as limited to the forms shown which are to be considered illustrative rather than restrictive. | A building air conditioning and heating system includes an air handling system set up to separately control different zones of a building. The air handling system has a blower connected to an air duct system in the building. At least two thermostats are positioned in different portions of the building for separately controlling the heating or the air conditioning in that portion of the building. A plurality of dampers are positioned in the air duct system, with each damper adapted to be opened and closed by gravity or air pressure. A damper locking means locks each damper in a closed position responsive to actuation by an electrical switch so that one zone of the building can be air conditioned or heated as desired. The thermostat can acutate the dampers and can control the temperature in one zone portion of the building while the other thermostat is disabled. Each damper has an electrical solenoid for locking the damper in one position. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims all benefits of Korean Patent Application No. 10-2007-0119812 filed on Nov. 22, 2007 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a security system and a securing method of a call signaling message for a SIP (Session Initiation Protocol) based VoIP (Voice Over Internet Protocol) service. More specifically, the invention relates to a security system and a securing method of a call signaling message, which block a message of call signaling messages transmitted/received between a transmit terminal and a server, which violates a message grammar, includes block information registered in a block list or is not suitable for a session state of the message, thereby enabling a VoIP service to be provided without an effect by a modified packet and the like.
[0004] 2. Description of the Related Art
[0005] A VoIP (Voice Over Internet Protocol) service is a common name of a service that provides a voice call using an IP network, and is an internet telephone service that is currently highlighted due to a convenient using method and low cost. In a telephone communication using the VoIP service, a call setup protocol is required. Among the various kinds of call setup protocols, a SIP (Session Initiation Protocol) is researched most actively.
[0006] The SIP based VoIP service is made with a call signaling message through the SIP and a call message using a RTP packet. Through the call signaling message, the information for a user registration, a request for call initiation and a call is exchanged. Through the call message, the voice packets corresponding to an actual call are exchanged. The SIP is defined in RFC 3261 (SIP: Session Initiation Protocol) that is the global standard prescribed by the International Standardization Organization IETF (Internet Engineering Task Force).
[0007] However, since the call signaling message and the voice packet are easily exposed, the VoIP service has such a security drawback that attacks such as payment avoidance, call termination, service denial or the like can be made on the service. This drawback is a potential threat to the VoIP service that is currently activated, and may give rise to a high damage when it causes a failure in the IP backbone network. Hence, it is needed a scheme to cope with the security threat to the VoIP service.
SUMMARY OF THE DISCLOSURE
[0008] Accordingly, the present invention has been made to solve the above problems. An object of the invention is to provide a security system and a securing method of a call signaling message, in which even when a call signaling message is leaked out and thus modified in a SIP (Session Initiation Protocol) based VoIP (Voice Over Internet Protocol) service, the modified message is blocked in advance to enable the VoIP service to be provided without an attack effect by the packets.
[0009] In order to achieve the above object, there is provided a security system of a call signaling message comprising: a message suitability verifying module that receives call signaling messages transmitted between a terminal and a server, blocks a call signaling message of the received call signaling messages which does not correspond to a preset format, and forwards the call signaling messages that are not blocked; a filtering module that receives the call signaling messages from the message suitability verifying module, blocks a call signaling message of the received call signaling messages which includes block information registered in a block list stored in advance, and forwards the call signaling messages that are not blocked; and a message state verifying module that receives the call signaling messages from the filtering module, blocks a call signaling message of the received call signaling messages which does not correspond to a session state of the call signaling message, and transmits the call signaling messages that are not blocked to the terminal or server.
[0010] According to an embodiment of the invention, there is provided a securing method of a call signaling message comprising the steps of: (a) receiving, at a message suitability verifying module, call signaling messages transmitted/received between a terminal and a server; (b) blocking a call signaling message of the call signaling messages received in the step of (a), which does not correspond to a preset format, and forwarding the call signaling messages that are not blocked to a filtering module; (c) blocking a call signaling message of the call signaling messages forwarded in the step of (b), which includes block information registered in a block list stored in advance, and forwarding the call signaling messages that are not blocked to a message state verifying module; and (d) blocking a call signaling message of the call signaling messages forwarded in the step of (c), which does not correspond to a session state of the call signaling messages, and transmitting the call signaling messages that are not blocked to the terminal or server.
[0011] When using the security system and the securing method of a call signaling message according to an embodiment of the invention, it is possible to prevent, in the SIP based VoIP service, a call signaling message from being modified to cause a call failure when requesting a call or during the call, and to block an attack on the call signaling message in advance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0013] FIG. 1 is a block diagram showing a structure of a SIP based VoIP service system;
[0014] FIG. 2 is a block diagram showing a structure of a security system of a call signaling message according to an embodiment of the invention;
[0015] FIGS. 3 and 4 are schematic views that exemplarily show a session state transition of a server resulting from receiving a call signaling message in a SIP based VoIP service system;
[0016] FIGS. 5 and 6 are schematic views that exemplarily show a session state transition of a terminal resulting from receiving a call signaling message in a SIP based VoIP service system;
[0017] FIG. 7 is a flow chart showing each step of a securing method of a call signaling message according to an embodiment of the invention; and
[0018] FIG. 8 is a flow chart showing each step of a message state verifying process in a securing method of a call signaling message according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.
[0020] The invention provides a security system and a securing method of a call signaling message for coping with an attack that may be made in a process of transmitting/receiving a call signaling message between a terminal and a proxy server in a SIP (Session Initiation Protocol) based VoIP (Voice Over Internet Protocol) service.
[0021] FIG. 1 is a block diagram showing a schematic structure of a SIP based VoIP service system. Referring to FIG. 1 , when a transmitter requests a call connection using a terminal 1 that he/she carries, a voice call is connected between a terminal 4 of a receiver and the terminal 1 of the transmitter via a transmit-side proxy server 2 and a receive-side proxy server 3 .
[0022] At this time, a security system 5 of a call signaling message according to an embodiment of the invention may be connected between the transmit terminal 1 and the transmit-side proxy server 2 . However, contrary to the embodiment shown in FIG. 1 , according to another embodiment of the invention, the security system 5 of a call signaling message may be connected between the receive terminal 4 and the receive-side proxy server 3 . The security system 5 of a call signaling message receives a call signaling message that is transmitted/received between the terminal and the server, verifies whether the received message is suitable, whether the message includes information registered in a block list and whether the received message is a message suitable for a session state, blocks a harmful message and enables only a suitable message to be transmitted.
[0023] The SIP based call signaling messages are classified into a request message and a response message. The request message is a message for performing a request such as a session request, a call termination and a state confirmation, for example INVITE, Cancel, BYE, Option and the like. The response message is a response or error notifying message to a request, for example 100 Trying, 180 Ringing, 200 OK, ACK and the like. One of the call signaling messages is structured as shown in a table 1.
[0000]
TABLE 1
Start Line
INVITE sip:bob@biloxi.com SIP.2.0
Massage
Via: SIP/2.0/UDP pc33.atlanta.com:branch=z9hGK776asdhds
Header
Max-Forwards: 70
To: Bob<sip:bob@biloxi.com
From: Alice <sip.alice@atlanta.com>:tag=1928301774
Call-ID: a84b4c76e667@pc33.atlanta.com
Cseq: 314159 INVITE
Authorization: Digest username=“gkar”
Contact: <sip: alice@pc33.atlanta.com>
Content-Type: application/sdp
Content-Length: 142
Route: <sip:p1.example.com:lr>
Record-Route: <slp:p1.example.com:lr>
Massage
V=0
Body
O=alice 2345566342 2346553445 IN IP4 pc33.atlanta.com
S=
C=IN IP4 pc33.atlanta.com
T=0 0
M=audio 49170 RTP/AVP0
A=rtpmap:0 PCMU/8000
[0024] In the table 1, the start line includes a type of a message and receiver information. The message header includes mandatory information necessary for communication. The message body includes additional information necessary for communication.
[0025] In the SIP, items located in each row of the message header are referred to as fields. Among them, six fields of Via, Max-Forwards, To, From, Call-ID and CSeq are necessarily included as mandatory fields. The Via field indicates the information about hops through which the SIP message passes, the Max-Forwards field indicates the number of hops that are available for transmission, the To field indicates a receiver, the From field indicates a transmitter, the Call-ID field indicates an inherent identifier of a corresponding session and the CSeq field is a value that is increased by 1 (one) in accordance with a message order and indicates an identifier for identifying transaction that will be described below.
[0026] In addition, Route and Record-Route fields, which are additional fields, indicate a server address that will be necessarily passed through in transmission, and a server address that has been passed through, respectively. Moreover, an Authorization field indicates authorization-related information. The types of the SIP message and each field of the message header are specifically described in the RFC 3261 that is the global standard, and can be thus easily understood by one skilled in the art. Accordingly, the detailed descriptions thereof will be omitted.
[0027] FIG. 2 is a block diagram showing a structure of a security system of a call signaling message according to an embodiment of the invention. Referring to FIG. 2 , the security system of a call signaling message according to the above embodiment comprises a message suitability verifying module 10 , a filtering module 20 and a message state verifying module 30 .
[0028] First, the message suitability verifying module 10 receives a call signaling message that is transmitted/received for a call signaling between the server 2 and the terminal 1 and parses each field value from the received message. Then, the message suitability verifying module 10 examines whether the values described in each field are made in accordance with the description format of the SIP. As described above, the values and formats described in each field of a call signaling message are defined in the RFC 3261 standard.
[0029] In one embodiment of the invention, the message suitability verifying module 10 may examine whether harmful information is included in the value of each field of the call signaling message. Here, the harmful information means an unsuitable character string having a possibility of detouring a user authorization of a server in the VoIP service, for example a special character or a SQL (Structured Query Language) command, which deviate from a description format of the SIP. The message suitability verifying module 10 determines whether a message is suitably prepared in each value of the mandatory fields of a call signaling message such as From, To, Via, Call-ID, Max-Forwards and CSeq fields, the extended fields such as Route and Record-Route fields or the authorization-related fields such as Authorization and Proxy-Authorization fields, and retrieves the harmful information to determine whether the corresponding message is modified.
[0030] When it is determined that the field value is unsuitable or the harmful information is included, as a result of the retrieval, the corresponding message is blocked by the message suitability verifying module 10 and the messages that are not blocked are forwarded to the filtering module that will be described below.
[0031] The filtering module 20 is a module for receiving a call signaling message from the message suitability verifying module 10 , for which the verification has been completed, and blocking a message including block information registered in a block list stored in advance. The module comprises a block list DB 22 and a filtering unit 21 .
[0032] A block list that is based on the fields of the SIP call signaling message is stored in advance in the block list DB 22 . For example, the block list is a character string for the field values of the SIP call signaling message. According to an embodiment of the invention, the block list may be inputted in advance to the block list DB 22 by a service provider, or alternatively, may be stored in the block list DB 22 through an intrusion detection system (IDS) for the SIP protocol.
[0033] The filtering unit 21 filters the call signaling message using the block list stored in the block list DB 22 . In one embodiment of the invention, the filtering unit 21 compares each field value of the header of the call signaling message with the character string registered in the block list. When any one field includes the character string in the block list, the filtering unit blocks the corresponding call signaling message. That is, when the character string recorded in the fields of a call signaling message, such as From, To, Via, Route, Record-Route and the like, is registered in the block list, the corresponding call signaling message is blocked.
[0034] The block lists stored in the block list DB 22 may be inputted by receiving the block-lists already-collected from an administrator before the filtering unit 21 operates, or may be inputted through an analysis of a result detected in the intrusion detection system (IDS) for the SIP protocol. The invention is not limited to a method of recording the block list.
[0035] The state verifying module 30 receives a call signaling message for which the verification has been completed by the message suitability verifying module 10 and the filtering module 20 , and verifies whether the call signaling message corresponds to a session state stored in a terminal or server that will receive the corresponding message, based on a transaction flow of a call signaling message disclosed in the RFC 3261. If the call signaling message does not correspond to a session state, the state verifying module 30 determines that the corresponding call signaling message is modified and thus blocks the message.
[0036] The SIP is a transaction based protocol in which a call signaling message transits a corresponding session state of a transaction layer of a terminal or server that has received the corresponding call signaling message. The transaction layer is a functional module that is used to receive a signaling message in a server or terminal in accordance with a call connection state. The types of a message that a server or terminal can receive are different in accordance with the state transition. Accordingly, the invention uses this to select and block an unsuitable message.
[0037] FIGS. 3 to 6 are schematic views that exemplarily show session state transitions of transaction layers of a server and a terminal by a call signaling message. In a SIP based communication, changes in session states of a server and a terminal resulting from receiving an INVITE message, which is a message requesting a call connection, and a message except the INVITE message are specifically defined in the RFC 3261. Hence, since one skilled in the art can easily understand the changes in the session states, the changes will be just schematically described in the specification.
[0038] FIG. 3 shows a session state transition of a server resulting from receiving an INVITE message for starting a call when the INVITE message is introduced into a server. The rectangles indicate session states of a server, the arrows between the rectangles indicate state transitions and the characters or numbers written near the arrows indicate types of messages necessary for a state transition.
[0039] Referring to FIG. 3 , when an INVITE message is originally introduced into a server, a session state of the server is transited to a Proceeding state. Under this state, the server can receive the messages, for example INVITE message, 1XX response, 2XX response, 3XX to 699 response and transport error. In addition, when 300 to 699 response is received, the session state is transited to a Completed state. Moreover, when an ACK message is received under the Completed state, the session state is transited to a Confirmed state. When a Timer message is received under the Confirmed state, the session state is transited to a Terminated state.
[0040] FIG. 4 shows a session state transition of a server and a type of a message that can be received at each state, when a message except the INVITE message is received. As shown, a session state is transited to Trying, Proceeding, Completed and Terminated states in accordance with the messages received.
[0041] Meantime, FIGS. 5 and 6 show a change in a session state of a terminal resulting from receiving an INVITE message and a message except the INVITE message, respectively. Referring to FIG. 5 , a session state of a terminal having received an INVITE message is transited to Calling, Proceeding, Completed and Terminated states in accordance with a message state. In the meantime, referring to FIG. 6 , a session state of a terminal having received a message except the INVITE message is transited to Trying, Proceeding, Completed and Terminated states in accordance with a message state. Also in FIGS. 5 and 6 , the types of the messages necessary for a transition between the respective states and the state transitions are indicated by the characters and the arrows, likewise FIG. 3 .
[0042] Referring back to FIG. 2 , the state verifying module 30 comprises a server state DB 32 , a terminal state DB 33 and a state verifying unit 31 . The server state DB 32 stores session state information of a transaction layer of a server and the terminal state DB 33 stores session state information of a transaction layer of a terminal. The state verifying unit 31 receives a call signaling message from the filtering module 20 and refers to the server or terminal, which will receive the call signaling message, for the state information of the corresponding session, thereby verifying whether the message is suitable.
[0043] In the SIP based VoIP, each call that is controlled by a call signaling message has an inherent value recorded in a Call-ID field and the like of the message header. The state verifying unit 31 retrieves the inherent value from the server state DB 32 or terminal state DB 33 , thereby referring to a terminal or server, which will receive the call signaling message forwarded, for a corresponding session state.
[0044] To be more specific, when a call signaling message to be transmitted to the transmit-side proxy server 2 from the transmit terminal 1 is forwarded, the state verifying unit 31 refers to the server state DB 32 for the corresponding session state information of the transmit-side proxy server 2 that will receive the message. When the forwarded call signaling message is suitable for a current state, the state verifying unit 31 transmits the corresponding message to the transmit-side proxy server 2 . When the forwarded call signaling message is not suitable for a current state, the state verifying unit 31 blocks the corresponding message while considering it as a modified message. For example, referring to FIG. 3 , when the transmit-side proxy server 2 is under the Completed state, as a result that the state verifying unit 31 refers to the server state DB 32 , if a 1XX or 2XX message is introduced from the filtering module 20 , this does not correspond to the current session state of the transmit-side proxy server 2 , so that the corresponding call signaling message is blocked.
[0045] To the contrary, when a call signaling message to be transmitted to the transmit terminal 1 from the transmit-side proxy server 2 is forwarded, the state verifying unit 31 refers to the terminal state DB 33 for the corresponding session state information of the transmit terminal 1 . Likewise, when the call signaling message is suitable for a current state of the transmit terminal 1 , the state verifying unit 31 transmits the corresponding message to the transmit terminal 1 . When the call signaling message is not suitable for a current state of the transmit terminal 1 , the state verifying unit 31 blocks the corresponding message while considering it as a modified message.
[0046] Furthermore, in an embodiment of the invention, when the session state information corresponding to the call signaling message forwarded from the filtering module 20 is not stored in the server state DB 32 or terminal state DB 33 , the state verifying unit 31 may store a change in a session state of the server or terminal due to the corresponding call signaling message in the corresponding DB.
[0047] FIG. 7 is a flow chart showing each step of a securing method of a call signaling message according to an embodiment of the invention. Referring to FIGS. 2 and 7 , a securing method of a call signaling message according to the embodiment is started as the message suitability verifying module 10 receives a SIP based call signaling message from the terminal or server (S 1 ). The message suitability verifying module 10 divides the received call signaling message into each field value and examines whether each field of the message is suitable for a preset format, particularly the preset harmful information such as special character or SQL (Structured Query Language) command is included in the authorization field (S 2 ). The message having an unsuitable message type or harmful information is blocked by the message suitability verifying module 10 (S 5 ).
[0048] The message suitability verifying module 10 forwards the call signaling message having the suitable message to the filtering module 20 . The filtering module 20 examines whether the forwarded call signaling message includes a character string of the field registered in the block list (S 3 ). The message having a character string of the field in the block list is blocked by the filtering module 20 (S 5 ). The character string of the field registered in the block list may include, for example an address of a server that transmits a modified packet, and the like. The block list having the character strings for the fields is stored in advance in the block list DB 22 . The filtering unit 21 of the filtering module 20 refers to the block list DB 22 for the block list, thereby blocking a corresponding call signaling message.
[0049] The call signaling message for which the filtering has been completed by the filtering module 20 is forwarded to the message state verifying module 30 . The message state verifying module 30 determines whether the forwarded call signaling message is suitable for a corresponding session state in the server or terminal that will receive the call signaling message (S 4 ). The call signaling message, which is not suitable for the state of the terminal or server that will receive the message, is blocked (S 5 ).
[0050] The session state information of the SIP based terminal or server is stored in the terminal state DB 33 and the server state DB 32 , respectively. The state verifying unit 31 of the state verifying module 30 refers to the terminal state DB 33 or server state DB 32 in accordance with the object that will receive the call signaling message, thereby selectively blocking the unsuitable message. Meantime, the other call signaling messages not blocked are transmitted to the terminal or server in accordance with the object that will receive the message (S 6 ).
[0051] FIG. 8 is a flow chart showing each step of a state verifying process of a call signaling message in a securing method of a call signaling message according to an embodiment of the invention. Referring to FIGS. 2 and 8 , the state verifying module 30 receives a call signaling message from the filtering module 20 (S 41 ). When the call signaling message is forwarded, the state verifying unit 31 of the state verifying module 30 refers to the server state DB 32 or terminal state DB 33 so as to check whether the session state information corresponding to the call signaling message is stored therein (S 42 ).
[0052] For example, when the call signaling message is transmitted to the terminal from the server, the state verifying unit 31 refers to the terminal state DB 33 . When the call signaling message is transmitted to the server from the terminal, the state verifying unit refers to the server state DB 32 . In an embodiment of the invention, when the session state information corresponding to the call signaling message is not stored, as a result of referring to the server state DB 32 or terminal state DB 33 , the state verifying unit 31 may store the session state information by the call signaling message in the server state DB 32 or terminal state DB 33 (S 43 ).
[0053] As a result of referring to the server state DB 32 or terminal state DB 33 , when the session state information corresponding to the forwarded call signaling message is stored therein, the state verifying unit 31 determines whether the corresponding call signaling message is a message transmitted from the terminal (S 44 ). When the call signaling message is transmitted from the terminal, the state verifying unit refers to the server state DB 32 to determine whether the call signaling message is suitable for the current session state of the server (S 45 ). In the meantime, when the call signaling message is not a message transmitted from the terminal, i.e., when the call signaling message is transmitted from the server, the state verifying unit refers to the terminal state DB 33 to determine whether the call signaling message is suitable for the current session state of the terminal (S 46 ).
[0054] When using the security system and the securing method of a call signaling message according to an embodiment of the invention, it is possible to block a call signaling message of the call signaling messages transmitted/received in a SIP based VoIP service, which is not suitable for a format, includes the harmful information, includes a character string of a field registered in the block list or does not correspond to the transaction state of the terminal or server that will receive the message, thereby preventing a modified call signaling message from being introduced. Hence, it is possible to prevent a call failure from being caused when requesting a call or during the call in the VoIP service, and to block an attack on a call signaling message in advance.
[0055] While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the invention as defined by the appended claims. | Disclosed is a security system of a call signaling message. An object of the invention is to provide a security system and a securing method of a call signaling message, in which even when a call signaling message is leaked out and thus modified in a SIP (Session Initiation Protocol) based VoIP (Voice Over Internet Protocol) service, the modified message is blocked in advance to enable the VoIP service to be provided without an attack effect by the packets. When using the security system and the securing method of a call signaling message according to an embodiment of the invention, it is possible to prevent, in the SIP based VoIP service, a call signaling message from being modified to cause a call failure when requesting a call or during the call, and to block an attack on the call signaling message in advance. | 7 |
This is a continuation of Ser. No. 06/534,097 filed Sept. 20, 1983, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to safety pressure relief devices and, in particular, to rupture discs, especially reverse buckling rupture discs, and also to methods of manufacturing such discs and of producing failures in such discs which are highly predictable.
Relief devices of the type commonly known as rupture discs have been utilized by industry for many years to provide a safety mechanism to relieve excessive pressure from an overpressurized system or vessel in a reliable manner. The rupture disc is most frequently placed in a vent for a pressure vessel or the like so as to prevent flow of fluid through the vent until the disc ruptures. Through the years, numerous improvements have been made in the rupture disc concept in order to reduce the cost and to improve the reliability of the disc.
A specific type of disc normally referred to as a reverse buckling rupture disc has also been utilized for a number of years and functions under the principle that a dome is formed in the disc which is positioned in the vent such that the dome points toward or faces the pressure side of the vent, that is, the convex side of the dome faces the internal portion or upstream side of the vent wherein pressurized fluid is likely to produce an overpressure which would be dangerous or destructive if not relieved. One advantage of reverse buckling type discs is that systems being protected by the discs can be operated at pressures relatively close to the bursting pressure of the disc without producing fatigue and failure which occurs in many forward bursting discs when operated for long periods of time near the rated bursting pressure of such discs. The dome, when fluid pressure reaches a preselected pressure for which the dome was designed to rupture, starts to collapse, that is, the column or arch of the dome on one side thereof starts to buckle. It is believed that as the arch on one side of the dome starts to collapse, a buckling type wave typically propagates across the surface of the dome to the opposite side of the dome where total collapse eventually occurs. This buckling wave tends to create a whiplash effect on this opposite side of the dome so that the dome at this location is rather violently urged in the direction to which the concave portion of the dome faces (that is, the downstream side of the vent). Many of the reverse buckling rupture discs include knife blades positioned on the concave side of the dome which are normally in spaced relationship to the dome but which are engaged by the dome upon buckling. The knives cut the dome, typically in such a pattern as to cause petals which are held to a flange portion of the disc by tab regions or the like.
Knife blade assemblies for reverse buckling rupture discs add substantially to the cost of such discs and are subject to failure due to corrosive activities of the fluids within the vent system, damage during handling or simply because a mechanic forgets to install the knife assembly which in normal discs results in disc bursting pressures that are many times the rated pressures of such discs. It has, therefore, been a goal of the rupture disc industry to produce a disc of the reverse buckling type which does not include knife assemblies, but which is highly reliable., One reverse buckling rupture disc, which was specifically designed to rupture without the use of knife blades, incorporates the concept of placing grooves, scores or etchings, especially in criss-cross or circular patterns on concave or convex faces of a reverse buckling rupture disc dome. A dome of this type can be seen in U.S. Pat. No. 3,484,817 of Wood. In the Wood device the rupture disc dome buckles, reverses and fractures along the lines of weakness produced by the grooves so as to form petals which are held to the remainder of the rupture disc assembly.
There has been a continuing desire in the rupture disc industry to produce new types of reverse buckling rupture discs which have properties that make them especially suitable for specific purposes, more cost efficient, and/or make the disc more reliable. In particular, new reverse buckling rupture discs are desired which will function without the need for knife blades for cutting the disc on reversal, yet which will remain highly reliable so as to relieve within a relatively close tolerance of the predetermined rupture pressure necessary to protect the vessels or the like which are protected by the disc.
There has also been a problem associated with some reverse buckling rupture discs which do not have knife blade assemblies in that the disc can accidentally be inserted into the vent system with the concave side facing in the wrong direction. Therefore, it is important that the rupture disc relieve in either direction, although the relief in the backward direction may normally be at a higher pressure.
There is also a problem in some systems with portions of the rupture disc being entrained with the fluid being relieved. Pieces of rupture discs can cause damage to pumps and the like if they are allowed to freely break away from the remainder of the rupture disc assembly upon rupture. Therefore, it is important that the rupture disc dome or petals of the rupture disc dome remain intact after rupture and that they remain attached to a remainder of the disc.
OBJECTS OF THE INVENTION
Therefore, the principal objects of the present invention are: to provide a rupture disc system which is highly reliable such that the rupture disc associated with the system ruptures within a relatively close range on either side of a preselected pressure to protect a vessel or the like from overpressure; to provide such a system including a reverse buckling rupture disc which does not require a knife assembly to open; to provide such a reverse buckling rupture disc which will reliably rupture at a first given pressure when fluid pressure is applied to the convex side thereof and at a second given pressure, for example 1.5 times the first given pressure, when fluid pressure is applied to the concave side thereof; to provide such a rupture disc including hinge or tab means for retaining the disc or portions of the disc with the remainder of the rupture disc assembly after rupture of the disc; to provide a structural configuration of the disc which ensures that the disc will first fail on the side of the disc associated with the hinge or tab and therefore first tear between a dome and flange portion of the disc opposite such hinge or tab and thereafter tear to the edge of said tab leaving the hinge or tab intact; to provide such a disc having indentations or dimples spaced from the hinge or tab region in the dome, especially on the dome directly and between the tab region and a crown of the dome, so as to initially trigger failure or buckling of the rupture disc adjacent to the tab or hinge; to provide such a reverse buckling rupture disc having a change in radius in a transition region between the disc dome and flange portions adjacent the tab or hinge region so as to ensure initial failure or buckling of the disc in the region of the dome directly between the tab region and the dome crown; to provide such a disc utilizing an arcuate projection into the vent assembly opposite the concave side of such disc and spaced closely adjacent the hinge or tab region of the disc for the dome to wrap about after rupture thereof; to provide such a disc having a groove or etching in the transition region between the dome and the flange portion of the disc; to provide such a groove or etching which is approximately two-thirds the depth of the transition region; to provide such a disc having a groove which extends only partially about the transition region and defines the tab or hinge region thereof within the portion of the transition region wherein the grooving or etching does not occur; to provide such a system including support rings on either side of the flange portion of the rupture disc which cooperate with the disc to ensure that the grooved area in the transition region is supported on the concave or downstream side of the rupture disc dome and that the rupture disc is also free to fracture toward the convex side thereof without being held in place or restricted from buckling by the support ring on that side after rupture; to provide a method of manufacturing such a rupture disc having a groove in the transition region including a method and apparatus for producing the groove; to provide a method for forming an indentation on the side of the rupture disc dome associated with a hinge or tab; to provide a method of producing a rupture disc of the type described having a transition region with a portion thereof associated with a tab region having a greater radius than the remainder thereof, so as to provide a first buckling area, in the tab region; to provide a method of placing a continuous circular groove in the transition region between a dome and a flange portion of the rupture disc with varying depths so as to define a tab region; and to provide an overall rupture disc system which is relatively economical to manufacture, convenient to install, highly reliable, and particulary well adapted for the intended usage thereof.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
SUMMARY OF THE INVENTION
A rupture disc assembly is provided which includes a domed or pre-bulged rupture disc of the type utilized to protect pressure vessels or the like from over pressure. The rupture disc is preferably a reverse buckling disc, but certain of the improvements discussed hereinafter may be utilized in conjunction with a conventional forwardly opening disc. The improvements discussed herein derive from experimentation directed to finding a rupture disc which would not only relieve at a preselected pressure (normally the preselected pressure is approximately 2/3 of the maximum rated rupture pressure associated with the vessel or other processing equipment to be protected by the disc), but also would re)ieve at a second preselected pressure, if the rupture disc were inadvertently installed backward (such second pressure for example being approximately the maximum rated pressure of the vessel, again for example, at a pressure 1.5 times the first preselected pressure).
It was especially desired to produce a reliable reverse buckling rupture disc which would predictably rupture at such a first preselected pressure, and which would also rupture at said second preselected pressure if the disc were inadvertently placed in the vent line backward, and further that the disc should rupture without the aid of a knife assembly as knife assemblies are expensive and may be susceptible to corrosion, damage, and the like which produces failure in such knives or the knife blades may be accidentally left out of the assembly during installation.
With this in mind, numerous structures were tested but failed to have the predictable rupture pressures required of such devices. Contrary to conventional thought in the rupture disc industry against making any modifications in the region of the reverse buckling rupture disc between dome and flange portions (normally referred to as a transition area or region), other than to change the radius thereof, it was discovered that placing of a groove within the transition area produced suitable and highly repeatable release pressures in either direction.
A full circle groove in the transition area of a reverse buckling rupture disc produced highly repeatable results when the groove was manufactured in a consistent fashion. It is noted that the groove may affect the bursting pressure of the disc as compared to the disc before the groove is added, however, the important result with the groove as with other improvements discussed herein, is that the bursting pressure be consistently reproduceable in successive discs which are modified or produced in the same manner.
It was found that a satisfactory groove could be made by placing a die with a knife edge under pressure against the transition area and allowing the knife edge to penetrate the area. It was found that a particular knife blade had to be tested with each different disc to see if that blade was compatible with the disc. For example, flatter or oval edged knife blades were found to be suitable for discs which are thicker, while more V-shaped knife blades with a radius from about 0.003 to 0.015 inches on the edge were found to be better for relatively thinner discs. One suitable V-shaped knife blade for certain rupture discs was found to be a blade having in cross section a central axis which is perpendicularly aligned with the surface of the flange portion of the disc when forming the groove, sides of the blade which diverge generally from the central axis and specifically from a point or knife edge at angles of approximately thirty degrees, and an edge which has a radius of approximately 0.005 inches. The radially inner side of the knife blade is preferably placed close to or adjacent the domed portion of the disc and it is not unusual for the radius of curvature of the dome at its juncture with the transition region to change during manufacture of the groove. While the exact depth of penetration of the knife blade into the transition area varies with the desired bursting pressure in each direction, thickness of the disc and with materials of construction, it was found in some discs that a groove depth of approximately two-thirds the thickness of the transition area is often quite suitable for producing the effect of bursting at the first preselected pressure in one direction and bursting at a pressure approximately 1.5 times the first preselected pressure in the opposite direction, if the disc were inadvertently installed backward. A groove depth of 40 to 50% of the disc normal thickness was often found to be sufficient to produce tearing upon buckling in most discs. However, it is specifically noted that depths of the groove cited herein are for purposes of example and that the depth required for a certain disc (that is a specific disc having a fixed thickness, material of construction, temper, etc.) to relieve at a certain pressure can only best be determined by experimentation. It is important that the reverse buckling rupture disc with the groove in the transition area be supported on the downstream side thereof (that is, on the side of the disc where fluid pressure would normally not be applied and also on what would normally be the concave side of the dome portion of the disc). The structure supporting the rupture disc in this manner preferably extends along substantially the entire portion of the transition area, especially where grooved. When reference is made herein to the groove being "in the transition area", it is meant that it is placed on the disc in such a manner as it would at least touch the original transition area. Actually, a modified transition region is normally formed when the groove is placed on the disc.
While the full circle grooving in the transition region works well for reverse buckling rupture discs wherein it does not matter if fragments of the ruptured disc are carried downstream in the vent line after the rupture disc bursts, it is often desirable to retain the rupture disc as an integral, although ruptured, unit even after bursting. For this, a hinge or tab is placed between the dome portion and the flange portion of the rupture disc. One method to provide such a tab, is that grooving is applied to the transition region in a partial circumferential manner so as to define such a tab region by that portion of the transition region which has not been grooved. For example, a thirty degree arc of the transition region may be left ungrooved while a continuous 330 degree remaining arc is grooved. Tabs of larger and smaller area have been found to be functional and the optimum tab arc depends on the particular disc.
While producing a tab region by not grooving a certain portion of the disc on the transition region functions well for certain discs and utilizations, it is found that normally the larger the ungrooved area, then the more unpredictable the bursting pressure of the disc becomes. In addition, in certain discs the violence of the rupture will cause a tear through such a tab region. It was found that a disc with a more reliable bursting pressure and yet with a tab region could be manufactured by utilizing a die with a generally continuous or full 360 degree arc knife, by changing the characteristics of the knife in the region desired to be left as a tab.
In particular, a portion of the knife edge is removed corresponding to the desired size of the tab, such that during the grooving process the knife does not form a groove in that portion where the edge is modified or at least does not form as deep a groove in the projected tab portion. The knife blade does apparently change the radius of curvature of the transition region adjacent the projected tab area even though it is not as deeply grooved, if at all; and, while applicant does not wish to be restricted to a certain theory of operation, it is believed that this change in radius modifies the characteristics of the disc in such a manner as to produce a disc which relieves at a more predictable pressure. Preferably, the knife blade is placed on the disc flange portion upstream flat surface next to the dome portion, and thereafter pressure is applied to the blade to urge it to penetrate into the flange portion along the transition region and, in particular, in a manner so as to penetrate generally perpendicular to the flat sides of the flange portion. It is noted that the maximum depth of penetration of the knife blade in the transition region is preferably accurately controlled by use of stops or the like.
It is generally believed in the industry that reverse buckling rupture discs tend to collapse or buckle on one side of the dome at which time a buckling type wave propagates out over the top of the dome to the opposite side of the dome. As the wave hits the opposite side of the dome there is a whiplash effect which violently thrusts the side of the dome associated with such whiplash in a downstream direction and tears the dome from the flange portion, which tear then propogates back around the disc to the side where the buckling first occurred. This whiplash buckling effect is often sufficiently strong to break the tab region of the rupture disc, if failure of the disc first occurs opposite such tab. Therefore, in order to provide even more reliability to the tab in order to prevent fragmentation of the disc, it is desired to first initiate failure of the disc in the tab region so that the whiplash effect will occur opposite the tab region.
A suitable technique for inducing failure of the disc first in the area of the dome in close association with the tab region has been found to comprise substantially modifying the radius of curvature of the transition area adjacent (that is coextensive with) the tab region or adjacent a portion of the tab region. Pre-bulged rupture discs are often manufactured by applying fluid pressure to one side of a flat plate of sheet metal stock while supporting the opposite side of the stock against a forming ring, the interior diameter of the forming ring defines the chordal diameter of the dome of the disc to be formed in the plane of the projected flange portion. The disc thus domes up through the forming ring. The edge of the forming ring is normally a fairly sharp 90 degree angle which forms a specific radius of curvature at the transition area. By breaking or rounding the radially internal edge of the ring where it engages the disc with a whetstone or the like, the radius of curvature of the transition area of the resulting rupture disc varies where such rounding occurs in the forming ring as compared to where no rounding has occurred. In this way the radius of curvature can be increased along that portion of the transition area of the disc associated with the tab region to ensure initial failure of the dome in close proximity to the tab region (especially on an arc of the dome which is centered on the tab region and extends to near the dome crown).
A second method has also been found for inducing the initial failure of the dome at or relatively near a selected location. This second method comprises placement of a dent, dimple, or other deformation, which will generally be referred to herein as an indentation, in the dome itself at a location spaced from the transition region and further in spaced relationship to the crown of the rupture disc but in close proximity to the projected tab region. Preferably, the center of the indentation is directly on an arc of the dome extending between the top or crown of the dome and the tab region, that is located on the dome on an arc directly connecting the center of the tab with the dome crown. Such an indentation may take the form of a dot, an elongate chord or arc running generally parallel to the transition region of the disc, a series of dots or lines defining indentations, or the like. It has been found that the failure of the dome may occur anywhere along the indentation; therefore, a relatively short indentation, for example not exceeding thirty degrees in arc, may be desirable for certain applications but larger indentations do function to ensure failure somewhere along the indentation. It is preferred that the indentation not substantially reduce the wall thickness of the dome and that it be placed unsymmetrically with respect to the dome. The height of the placement of the indentation relative to the overall height of the dome may vary in accordance with the desired failure pressure (typically, the closer to the crown, the greater reduction in rupture pressure for a particular disc). A suitable height for an indentation has been found to be, for example, approximately 0.06 inches from the transition region for some discs. Again optimum shape and placement of the indentation for a particular disc is found by testing.
Suitable indentations can be produced in the dome by placing an edge or point against the dome at the desired location while applying pressure to the opposite side of the dome. This can advantageously be accomplished in conjunction with the pre-bulging of the disc. In particular, a second indentation ring may be used adjacent the bulge forming ring which forming ring defines the perimeter of the dome during formation thereof. Such an indentation ring rests atop the bulge forming ring and has an edge or point against which the dome is urged during formation thereof. Spacing of the indentation ring from the flange portion is controlled by the thickness of the forming ring. Suitable types of rings have been found to include a circular ring which has the same interior diameter as but is slightly non-concentrically aligned with the bulge forming ring so as to place a dent in the dome at the location above or in close association with the projected tab region. Other rings include those concentrically aligning with the bulge forming ring but having a curved or linear edge on the radially inner side of a projection extending radially inwardly from the ring. It has been found that the relief pressure of the disc varies significantly with which type of indentation ring is utilized so again testing must be used to find the relief pressure of a given disc with a specific indentation, but, if all factors remain the same for consecutive discs, then each should relieve at the same pressure. The indentation can also be formed in a procedure separate from the pre-bulging procedure.
Finally, it has been found that the force associated with rupture of certain discs will tear the tab region, even when initial failure of the disc is on the side of the dome associated with the tab region. It has been found that, if an arcuate projection extending radially inward from the side of the vent below the tab region is provided for the dome to wrap about upon rupture while the tab is still intact, then the tab region is less likely to tear. When it is indicated herein that the projection is below or aligned with the tab region, it is meant that the projection should be downstream in the vent relative to the unruptured disc, on the concave side of the rupture disc prior to rupture, and could refer to such a projection which was actually spacially "above" the disc but still downstream from same. In particular, the projection should be aligned such that as the dome pivots about the hinge formed by the tab region upon rupture, the dome engages the projection. Projections which have a linear or chordal engaging surface have been previously used in the art, but have been found to sometimes allow the dome to continue to rip along the tab region and, therefore, were not generally found to be satisfactory for the disc described herein. On the other hand, projections which are relatively arcuate in nature and project radially inward from the side of the vent, especially those that are almost circular or nearly approximating the curvature of the dome were found to be most suitable.
A suitable projection for certain uses was found to be one that is generally flat on sides thereof facing toward and away from the rupture disc prior to bursting and which has the facing surface in a plane which is generally adjacent a plane defined by the downstream side of the flange portion. Further, the example projection has a thickness of approximately 0.060 inches, has a radially inwardly projecting edge which is almost circular, and has a radius roughly between one-fourth and one-fifth the radius of the inner diameter of the disc flange portion. The example projection being attached to and extending along a downstream support ring for the disc through an arc length which is preferably slightly longer than the arc length associated with the tab region. For example, if the arc of the tab region is approximately 30 degrees, then the projection would extend for an arc of approximately 34 degrees. In this manner, the transition area of the disc tears along the groove upon rupture to the tab region and such that the edges of the dome next to the tab region do not align exactly with the projection but tend to wrap thereabout so as to further secure the ruptured dome to the projection until a maintenance crew can change the disc.
While the improvements discussed above have been described especially in terms of reverse buckling rupture discs, certain features of the improvements can be utilized in conjunction with other types of conventional rupture discs. In particular, it is foreseen that a circumferential groove may be utilized in a transition region of a conventional forward failure rupture pre-bulged disc to allow a failure if the disc is inserted backward and may be utilized in conjunction with typical grooves, slits or other devices on the dome of such forward acting disc which grooves, etc. cause failure in a normal forward direction.
It is noted that in some of the drawings, the scale of certain features has been exaggerated, where necessary, in order to show details thereof. This is especially true of the thickness of the various rupture discs relative to the assembly associated therewith. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a rupture disc assembly according to the present invention installed in a vent pipe between support rings with portions broken away to illustrate details of the assembly.
FIG. 2 is a top plan view of the rupture disc and support rings of FIG. 1 with portions of the lower support ring shown in phantom.
FIG. 3 is an enlarged, fragmentary cross-sectional view of the rupture disc and support rings taken along line 3--3 of FIG. 2.
FIG. 4 is an enlarged, fragmentary cross-sectional view of the rupture disc and support rings taken along line 4--4 of FIG. 2.
FIG. 5 is an exploded cross-sectional view of the assembly shown in FIG. 1.
FIG. 6 is a separated perspective view of the rupture disc and the lower support ring at a reduced scale.
FIG. 7 is a fragmentary cross-sectional view of the rupture disc assembly shown in FIG. 1 after rupture of the rupture disc.
FIG. 8 is a top plan view of a first modified rupture disc and support ring therefor for use in conjunction with the rupture disc assembly of FIG. 1, with portions broken away to show the support ring in greater detail.
FIG. 9 is an enlarged fragmentary cross-sectional view of the first modified rupture disc taken along line 9--9 of FIG. 8.
FIG. 10 is a side elevational view of the first modified rupture disc.
FIG. 11 is a perspective view of the first modified rupture disc and support ring thereof showing details of the disc and ring in phantom.
FIG. 12 is a perspective view of a second modified rupture disc and support ring therefor for use in the rupture disc assembly shown in FIG. 1.
FIG. 13 is an enlarged fragmentary cross-sectional view of the second modified rupture disc and support ring taken along line 13--13 of FIG. 12.
FIG. 14 is a top plan view showing a third modified rupture disc for use in conjunction with the rupture disc assembly of FIG. 1.
FIG. 15 is an enlarged fragmentary cross-sectional view of a fourth modified rupture disc for use in the rupture disc assembly of FIG. 1.
FIG. 16 is a perspective view at a reduced scale of a planar blank of material to be formed into a reverse buckling rupture disc according to the present invention.
FIG. 17 is a perspective view showing a reverse buckling rupture disc produced from the blank of FIG. 16 just following the formation of a bulge at a central portion of the disc and showing a die ring through which the bulge is formed with portions of the ring broken away to show detail thereof.
FIG. 18 is an exploded cross-sectional view of a rupture disc and a grooving apparatus having a knife blade die for placing a circumferential groove in the transition area between flange and dome portions of the disc.
FIG. 19 is an enlarged fragmentary cross-sectional view of the apparatus and disc of FIG. 18 showing the disc during the actual process step of forming a groove in the transition area thereof.
FIG. 20 is an exploded perspective view at a reduced scale of a rupture disc and the die from the grooving apparatus shown in FIG. 18 following etching of the disc in the transition area.
FIG. 21 is an enlarged fragmentary cross-sectional view of a reverse buckling disc during a step in a manufacturing process wherein the dome of the disc is urged upward through a forming ring.
FIG. 22 is a view similar to FIG. 21 at a different location around the ring and showing a change in the radius of the transition area associated with the rupture disc.
FIG. 23 is an exploded perspective view at a reduced scale of a rupture disc with upper and lower supporting rings during another step in the process of manufacturing of an assembly such as is shown in FIG. 1.
FIG. 24 is an enlarged fragmentary cross-sectional view of the rupture disc and the support rings of FIG. 23 after spot welding same together.
FIG. 25 is a fragmentary cross-sectional view similar to that of FIG. 24 but further enlarged in comparison and showing a rupture disc and support ring for use in the assembly of FIG. 1 and illustrates a groove in the transition region between the dome and flange area thereof.
FIG. 26 is a top plan view of the rupture disc and ring assembly shown in FIG. 23 with portions broken away to show detail thereof.
FIG. 27a is a top plan view of a dome forming a ringlet set for use in a step in the process of forming a reverse buckling rupture disc with an indentation on a dome thereof.
FIG. 27b is a view similar to FIG. 27a and illustrates a first modified dome formation ringlet set for forming a first modified indentation on a rupture disc during a process in the manufacture thereof.
FIG. 27c is a view similar to FIG. 27a and shows a second modified indentation formation ringlet set for forming a second modified indentation on a rupture disc.
FIG. 28a is a top plan view showing a fifth modified rupture disc having an indentation formed thereon by the ringlet set shown in FIG. 27a.
FIG. 28b is a view similar to FIG. 28a showing a sixth modified rupture disc having an indentation formed thereon by the ringlet set shown in FIG. 27b.
FIG. 28c is a view similar to FIG. 28a showing a seventh modified rupture disc having an indentation formed thereon by the ringlet set shown in FIG. 27c.
FIG. 29 is a cross-sectional view of a rupture disc during a step in the process of manufacture thereof and shown in a rupture disc bulge forming apparatus suitable for use alternatively with the ringlet sets shown in FIGS. 27a, 27b and 27c for the formation of an indentation on the rupture disc.
FIG. 30 is a cross-sectional view of a rupture disc similar to the disc shown in FIG. 29 but having an indentation formed thereon by the ringlet set of FIG. 27a.
FIG. 31 is a perspective view of a modified grooving apparatus knife holding member similar to the die of FIG. 20.
DETAILED DESCRIPTION OF THE INVENTION
As required, detailed embodiments of the present invention are disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
The reference numeral 1 generally designates a safety pressure relief assembly according to the present invention. The assembly 1, as is best seen in FIG. 1 and in the exploded view in FIG. 5, is secured between opposite flanges 2 and 3 which are end flanges of vent pipe sections 4 and 5 respectively and which are securely held together so as to clamp the assembly 1 therebetween by a plurality of circumferentially spaced bolts 6. The vent pipe sections 4 and 5 form part of a vent system including an interior channel 8. The vent system includes an upstream portion which is associated with vent pipe section 4 and which joins with a pressure vessel or the like (not shown) to be protected by the vent system and would also normally be the side of the vent system to be positively pressurized by fluid therein. Vent pipe section 5 discharges to a safe location (not shown) to relieve excess pressure communicating therewith from vent pipe section 4 upon relief by the assembly 1. The assembly 1 comprises a downstream support structure 11 (FIG. 5), a downstream seal member 12, an upstream support structure 13, and an upstream seal member 14. The assembly 1 further comprises a downstream support ring 16, an upstream support ring 17, and a reverse buckling rupture disc 18.
When the assembly 1 is in use, seal member 14, the support structure 13, the support ring 17, the rupture disc 18, the support ring 16, the support structure 11, and seal member 12 are in sequential, abutting and snug relationship with respect to one another so as to be generally resistant to fluid pressure leaks in a radially outward direction, this configuration being shown in FIG. 1. The assembly 1 is retained together by keeper brackets 20 and 21 which are secured to both of the support structures 11 and 13 by suitable bolts (not shown) or the like received in threaded apertures 23. There is a generally unrestricted upstream channel portion 24 extending from the upstream or convex side 27 of the rupture disc 18 to the vessel or the like being protected by the assembly 1 and a generally unrestricted downstream channel portion 25 extending from a downstream or concave side 28 of the rupture disc 18. The downstream support structure 11 includes an annular seat 30 for the support ring 16 and further includes an annular boss 31 which is positioned radially inward from the seat 30. The boss 31 extends circumferentially in conjunction with the seat 30 except for a sector 32 of the seat which angularly aligns with an arcuate projection 34 on the support ring 16.
Attention is directed to the support rings 16 and 17 and the rupture disc 18, such as are shown in greater detail in FIGS. 2, 3, 4 and 6. The rupture disc 18 is of the type commonly referred to as a reverse buckling rupture disc having a central pre-bulged dome 40, a generally planar flange portion 41 which extends radially outward from a periphery of the dome 40, and a transition area or region 42 between the dome 40 and the flange portion 41. The dome 40 has the disc convex side 27 and concave side 28 thereon, an apex or crown 43 and has a generally uniform thickness, although the thickness normally varies somewhat due to variances induced during the pre-bulging of the dome 40.
The rupture disc 18 further includes a semi-circular groove 44 which is in the transition region 42. A portion of the transition region 42 generally indicated by the reference numeral 45 does not include a groove therein and is a projected or designated hinge or tab region for the rupture disc 18 at the time of bursting. That is, upon bursting it is desired that the dome 40 tear away from the flange portion 41 along the groove 44 and that portion of the transition region 42 which is coextensive with the groove 44, while preferably the tab region 45 remains intact or untorn.
FIG. 4 shows a cross-sectional view including a portion of the transition area 42 having a groove 44 therein and FIG. 3 shows a cross-sectional view of a portion of the transition region 42 which does not include a groove. It is noted that preferably the upstream support ring 17 extends radially outward from approximately the center of the groove 44. In contrast, the support ring 16 extends radially inward of the transition region 42 so as to support the transition region 42 at least in the portion thereof including the groove 44. The support ring 16, as is seen in FIG. 6, includes the arcuate projection 34 which is downstream of and preferably aligned with the tab region 42 such that, when the rupture disc 18 bursts the dome 40 will pivot about the hinge region 42 and engage the arcuate, projection 34, as is shown in FIG. 7 wherein the ruptured and somewhat crumpled dome, as indicated by the reference numeral 46, wraps about the projection 34 especially in the area of the edges 47 of the dome 46 that tore from the flange portion 41 but which were adjacent the hinge region 42. The projection 34 is arcuate along its radially inward edge 48. The arcuate projection 34 has radially outward ends thereof 49 and 50 which include an arc therebetween which is generally similar to but slightly larger than the arc encompassed by the tab region 45.
Shown in FIGS. 8, 9, 10 and 11 is a first modified embodiment of the present invention including a first modified rupture disc 100 and support ring therefor 101 which are suitable for use in the assembly 1 as alternative replacements for the disc 18 and support ring 16 respectively. The support ring 101 is essentially similar to the support ring 16 and includes an arcuate projection 102 which extends radially inward therefrom. The arcuate projection 102 is downstream aligned with a tab region 103 of the disc 100. The disc 100 includes a dome 106 with a radially outward extending flange portion 107 joined by a transition region 108. A partially circumferential, relatively deep groove 112 extends entirely around the dome 106 except in the tab region 103 wherein there is a very shallow groove 113 compared to the relatively deeper groove 112. An indentation 114 is positioned in the dome as is best shown in FIG. 9. The indentation 114 is approximately centered on the tab region 103 and is spaced closely therefrom. The indentation 114 comprises an elongate dent which is oriented approximately parallel to the transition region 108.
FIGS. 12 and 13 show a second modified disc 130. The disc 130 is similar to the disc 100 except that instead of an elongate indentation 114, as seen in disc 100, the disc 130 has a dimple or dot indentation 132 on the dome 131 thereof. The disc 130 has a flange portion 133 and transition region 134 which are similar to the same features in the disc 100 in the previous embodiment. A tab region 135 is centered to be aligned with the indentation 132.
FIG. 14 shows a third modified rupture disc 140 according to the present invention including a dome 141 having an elongate indentation 142 therein. The disc 140 is similar to the disc 100 except for the placement and size of the indentation 142 as compared to the indentation 114.
FIG. 15 shows a fourth modified rupture disc 150 according to the present invention. Disc 150 includes a dome 151, a flange portion 152, and a transition region 153 between the flange portion 152 and the dome 151. A tab region 154 is specifically shown, and this disc 150 has a non-tab region (not shown) in the transition region 153 similar to that of the disc 100. The disc 150 also has a transition region with a slightly increased radius of curvature generally indicated by the arrow 155 in a portion of the transition region 153 as compared to the remainder thereof and specifically in the tab region 154.
FIGS. 16 through 26 illustrate different steps in the method of manufacture of a rupture disc of the present invention and illustrate various structures utilized in the manufacture of the present invention. FIG. 16 illustrates a planar sheet of metal or blank 200 from which a rupture disc, such as the previously described disc 18, is manufactured. FIG. 29 illustrates an apparatus 203 for forming a rupture disc from such a blank 200.
The apparatus 203 includes a lower member 204 and an upper member 205 which generally mate together so as to define a chamber 206 therebetween. A first sealing ring 209 is placed in a bottom of the chamber 206 followed by the planar sheet of metal 200 followed by at least one additional bulge forming ring 210. Preferably the outer diameter of the rings 209 and 210 and the blank 200 are approximately the same as the inner diameter of the chamber 206 where they interengage. A hydraulic fluid supply passage 211 communicates with a suitable source of hydraulic fluid through a hydraulic hose 212 with a lower portion 207 of the chamber 206, which chamber portion 207 is shown below the blank 200, to be pre-bulged into a domed rupture disc 213. It is noted that the blank 200 is not shown in FIG. 29 but the blank 200 occupies the same region as a flange portion 214 of the disc 213 as well as the region surrounded by the flange portion 214. After the blank 200 is placed in the apparatus 203, fluid is forced into the chamber portion 207 through the passage 211 while the disc blank 200 is securely held about the edges thereof in position so as to pre-bulge into the disc 213. FIG. 17 shows the disc 213 and the upper ring 210. As shown in FIG. 21, a lower inner radial edge 218 of the ring 210 defines an outer boundary or periphery 219 of a dome 220 of the disc 213. It is noted that the edge 218 is a sharp edge formed by sides of the ring 210 which meet at almost 90 degrees with respect to one another. FIG. 22 shows a view which is similar to FIG. 21 except it is taken at another location along the ring 210 whereat the sides of the ring 210 join in a rounded edge 222 which defines the limits or periphery 223 of the dome 220 at that location. A transition region 224 shown in FIG. 22 has a larger radius of curvature at that location than a transition region 225 shown in FIG. 21. This change in radius and/or slope is similar to the concept previously shown in and described for FIG. 15.
Shown in FIG. 27a is an alternative ring set 230 for use in conjunction with the apparatus 203 in place of the ring 210. The set 230 shown in FIG. 30 in conjunction with a disc 235 includes a lower forming ring 231 similar to the ring 210 and an upper indentation ring 232 which has a similar internal diameter to the ring 231 but is positioned somewhat eccentrically thereto. The ring set 230 is utilized in the production of the rupture disc 235, shown in FIG. 28a, having an indentation 236 thereon produced by a radially inward and lower edge 238 of the indentation ring 232 engaging the disc 235 as same is pre-bulged. An outer portion of the ring 232 is removed so that the ring set 230 has an overall outer diameter approximating the diameter of the disc 235 so that the ring set 230 and disc will set in the apparatus 203 without lateral slippage therebetween when the disc 235 is being bulged.
FIG. 27b shows a second offset ring set 250 having a lower forming ring 251 which is generally concentric with an upper indentation ring 252. FIG. 28b shows a rupture disc 255 manufactured in the apparatus 203 wherein the ring set 250 has been substituted for the ring 210. An indentation 256 is formed on the rupture disc 255 by a radially inward extending projection 257 having an inner surface 258 with a lower edge which engages the disc 255 during pre-bulging and produces the indentation 256. The surface 258 is arched to approximate the arc of the disc 255 where they engage and includes linear feathering on opposite sides of the surface 258.
FIG. 27c shows yet another ring set 260 having a lower forming ring 261 and a generally concentric upper indentation ring 262. FIG. 28c shows a rupture disc 265 manufactured in the apparatus 203 wherein the ring 210 has been replaced by the ring set 260. The upper indentation ring 262 includes a radially inwardly extending projection 267 generally comprising a chord or a linear joining of the two sides of the ring 262 and having an inner surface 268 with a lower edge which engages a disc 265 (FIG. 28c) during pre-bulging thereof so as to form an indentation 266 therein.
After pre-bulging and indenting (where done) in the apparatus 203, rupture discs, such as the disc 300 in FIG. 23, which were manufactured in the apparatus 203 are removed. The disc 300 has an indentation 301 thereon and a tab region 302 located in close association to the indentation 301. The disc 300 is then joined with an upstream support ring 311 and a downstream support ring 310. The rings 310 and 311 are similar to rings 16 and 17 shown in FIG. 1. The downstream ring 310 includes an arcuate projection 312 which is aligned to be centered relative to the tab region 302 and the indentation 301. The disc 300 and the rings 310 and 311 are then preferably joined together by welding or the like as shown in FIGS. 24 and 26 after groove 314 is formed in a transition region 315 thereof.
A grooving apparatus 330 for performing the grooving process is shown in FIGS. 18, 19 and 20. The apparatus 330, as shown in FIG. 18, includes an upper holder member 331, a lower holder member 332 which mates with the upper holder member 331, a die or knife holding member 333, and pressure exerting means such as the partially shown hydraulic press mechanism 334. A pre-bulged disc 337 is placed in a seat 338 in the upper holder member 331. The knife holding member 333 includes a circular knife 340 having an upper edge 341 and having a radius slightly larger but approximately the same radius as the inner edge of a transition area 348 of the disc 337. The knife edge 341 is placed in engagement with the disc transition area 348, as shown in FIG. 19, and pressure is applied by the press 334. Stops 349 on the knife holding member 333 engage the upper holder 331 to facilitate proper grooving of the disc 337 so that the groove 350, as seen in FIG. 19, has a proper depth associated therewith. The knife 340 shown in FIG. 20 is only partially circumferential and includes a sector 360 in which the knife 340 is omitted to leave a portion of the disc transition area 348 ungrooved. The stops 349 are removable from the knife holding member 333 to facilitate alternative use of the other stops specifically designed for other particular depths and/or other disc thicknesses.
Alternatively, the knife 340 can be replaced by a completely circumferential knife member or also, alternatively, by a knife member 357, as shown in FIG. 31, which is completely circumferential but for a portion 358 of the edge 359 of the knife blade which has been further rounded or had a portion of the edge removed so as to limit the depth of a groove in that region where the portion 358 engages the disc 337. The sides of the knife in FIG. 19 diverge from the edge 341 at an angle of approximately 60 degrees relative to one another and the cutting or grooving edge 359 has a radius of approximately 0.005 inches.
FIG. 25 shows an enlarged section of a rupture disc 380 having a lower support ring 381 and an upper support ring 382 associated therewith. The disc 380 has had a groove 383 according to the present invention placed in a transition region 384 thereof. The groove 383 was produced by a method similar to the groove 350 formed in the process shown in FIGS. 18 through 20. The groove 383 includes side walls 385 and 286 which diverge with respect to each other and at about 30 degrees each to an axis or vertical line bisecting the groove 383 and are joined by a connecting surface 387 having a radius of approximately 0.005 inches. The disc 380 has a dome 389, a periphery 390, a concave side 391 and a convex side 392.
It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown. | A rupture disc system comprises a ruptue disc including a dome portion and a flange portion interconnected by a transition region and a mounting mechanism for mounting the rupture disc by the flange portion thereof in a pressure relieving vent. The rupture disc includes a thickness reducing groove at least partially circumferentially surrounding the dome portion and located in the transition region thereof. Preferably, the rupture disc is of the reverse buckling type and the groove does not completely surround the dome portion so as to define a tab or hinge within that part of the transition region which is ungrooved or not as deeply grooved as a remainder of the transition region. In addition, the slope or radius of curvature may be increased in the region of the tab. The rupture disc also includes an indentation on the dome portion. The indentation is preferably greatest on the dome portion at a location spaced from the transition region and directly between the tab and a crown of the dome portion. In addition, the mounting mechanism includes a lower ring member having an arcuate projection which extends into the vent. Preferably, the arcuate projection is located so as to be relatively close to and so as to align with the tab such that the dome portion wraps about the projection when reverse buckling and rupture occurs. Methods are disclosed for producing the disc with the groove and the indentation. | 8 |
RELATED APPLICATIONS
U.S. patent applications Ser. Nos. 09/356,978 and 09/356,979 were filed concurrently herewith.
TECHNICAL FIELD
This invention is related to Time Division Multiple Access (TDMA) communications and, more particularly, to ranging in the transmission of TDMA signals.
BACKGROUND OF THE INVENTION
In TDMA transmission of signals it is required that all the individual signal components of the TDMA transmission have equal transmission delay. Consequently, a delay interval must be determined for each signal included in the TDMA transmission which when added to the individual signal yields a common loop delay for that signal equal to individual loop delay of the other TDMA signal components. To determine the particular delay to be added to each of the TDMA signal components, a so-called “ranging” procedure is effected when an equipment unit which will transmit the signal is installed, relocated, or otherwise has a disruption in service. A popular prior known ranging procedure is so-called “in-band ranging”, where in-band ranging messages are employed to effect the ranging procedure. Unfortunately, the use of the in-band ranging messages requires that the transmission bandwidth be temporarily interrupted and used for transmitting the in-band ranging messages. Thus, in-band ranging is an intrusive procedure that interferes with normal bandwidth use. Additionally, it is necessary to schedule when the in-band ranging is to be done. Indeed, as the rate at which in-band ranging is scheduled is increased, more and more transmission bandwidth is lost. This is extremely undesirable because the bandwidth cannot be used for other purposes, for example, constant bit rate transmission.
SUMMARY OF THE INVENTION
These and other problems and limitations of the prior known in-band ranging procedure are addressed by employing a non-intrusive out-of-band ranging technique. Ranging is automatically initiated at a customer premises equipment unit when the equipment is installed, when power is restored after a power failure or interruption, upon verification of the equipment, upon reconnection after a disconnection of the equipment or the like. To this end, an out-of-band tone is employed that is automatically transmitted when the customer premises equipment that transmits the TDMA signal is powered ON, or transmitted in response to a specific command generated locally or remotely.
Specifically, when ranging is being effected the customer premises equipment generates and transmits the out-of-band ranging tone until a message is received from a remote terminal indicating that the transmission of the ranging tone be terminated. The loop delay being determined is the delay interval between transmission of the termination message and detection that transmission of the ranging tone has terminated. Then, a message is transmitted to the customer premises equipment that contains the ranging delay interval that is to be used in all future transmissions to the remote terminal.
In one embodiment of the invention, the customer premises equipment automatically switches to an idle standby state when the remote terminal removes its upstream transmission slot. In the standby state, the customer premises equipment is still capable of receiving data and is periodically polled by the remote terminal assigning it an upstream transmission slot. If a customer premises equipment in the standby state is not polled during a predetermined interval, it automatically switches to a verification state.
Additionally, if the customer premises equipment does not respond when polled, the remote terminal transmits it a message putting it in the verification state. If a polled customer premises equipment responds with an out-of-band tone, which indicates that it is in the verification state, the remote terminal treats it as though it is verifying ranging. If the out-of-band tone is properly aligned, the customer premises equipment is switched to an active state.
An advantage of polling customer premises equipment in the idle standby state is that it enables system operations to distinguish between an idle customer premises equipment, power outages, disconnected or otherwise removed customer premises equipment.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows, in simplified block diagram form, a video distribution system employing an embodiment of the invention;
FIG. 2 shows, in simplified block diagram form, details of an ONU ranging delay unit employed in practicing the invention;
FIG. 3 shows, in simplified block diagram form, details of an OLC ranging delay unit employed in practicing the invention;
FIGS. 4A, 4 B and 4 C when connected A—A, B—B, C—C, D—D, E—E and F—F form a flow chart illustrating the steps in the ranging delay procedure of the ONU ranging delay unit of FIG. 2; and
FIGS. 5A and 5B when connected A—A and B—B form a flow chart illustrating the steps in the ranging delay procedure of the OLC ranging delay unit of FIG. 3 .
DETAILED DESCRIPTION
FIG. 1 shows, in simplified block diagram form, a video distribution system employing an embodiment of the invention. Specifically, shown is network 100 including video server 101 which supplies downstream video signals to broadband network 102 , in response to an upstream communication including a selection message. Broadband network 102 supplies the communications signals to and from optical line terminal 103 . At optical line terminal (OLT) 103 , optical line circuit (OLC) 104 interfaces to an optical fiber line. The optical fiber line is, for example, a power splitting passive optical network (PSPON) fiber including optical fibers 110 and 111 on which optical signals are transmitted using coarse wavelength division multiplexing. Transmission on the fiber lines 110 and 111 is achieved using two wavelengths, 1550 nano meters (nm) downstream, for example, to a home and 1310 nm upstream, for example, from the home. The PSPON fibers 110 may be split into a predetermined number of optical fibers, for example, 32 fibers 111 , thereby interfacing via associated ONUs 106 with 32 locations. Note that OLT 103 serves one or more OLCs 104 , namely, 104 - 1 through 104 -Z, coupled to a corresponding number of fiber lines, namely, 110 - 1 through 110 -Z, respectively, and that an OLC 104 serves one or more ONUs 106 via optical fibers 111 - 1 through 111 -W. In this example, the downstream transmission of video signals is in asynchronous transfer mode (ATM) cells via time division multiplex (TDM), while upstream transmission of communication is via time division multiple access (TDMA), and both downstream and upstream communications is at 155.52 Mb/sec. Efficient TDMA communications in the upstream direction requires all optical network units (ONUs) 106 to have equal loop delay in relationship to their associated OLC 104 . This is realized by employing a ranging procedure that is executed when each ONU 106 associated with a particular OLC 104 is installed, moved, returned to service, or the like. The ranging procedure defines an artificial delay that when added to the transmission loop delay of an ONU 106 yields the required common loop delay. The desired ranging delay is obtained, in this example, by employing a unique out-of-band ranging procedure, in accordance with the invention
Actually, OLT 103 is a special ATM switch including a traditional ATM fabric and input/output (I/O) ports. In this example, two types of I/O boards are required, namely, standard SONET (synchronous optical network) boards, e.g., OC-12 units, and OLC boards. Video signals received from OLT 103 as ATM cells from one or more SONET boards are distributed to the OLC boards. Because of this, upstream channel select messages being sent to a video services controller in video server 101 are intercepted within the OLT 103 , which accumulates the number of viewers of each video program that is OLT 103 wide. Only channel (program) selections that are not available within presently received SONET VCs are passed on to the video services controller 202 in video server 101 . Additionally, messages are sent by OLT 103 to video server 101 and, therein, to a video services controller therein (not shown) whenever a transmitted video program is no longer being viewed by any OLT 103 supported TV 107 . It is noted that each of OLC units 104 includes, in this example, a CPU and memory that may be a microprocessor with memory, as described below.
Optical network unit (ONU) 106 terminates the PSPON 111 fiber and provides appropriate interfaces, in this example, to one or more television sets (TVs) 107 - 1 through 107 -N. Each of TVs 107 - 1 through 107 -N has an associated one of remote control (RC) units 108 - 1 through 108 -N, respectively.
Network 100 supplies, for example, via one or more video services controller units in video server 101 in response to specific program requests, conventional broadcast TV programs, programs similar to those supplied via cable TV providers, satellite TV providers, video on demand and the like. Procedures for requesting and transmitting video programs are described in greater detail below.
As shown in FIG. 1, a residential video subsystem includes an ONU 106 and one or more TVs 107 and associated RC units 108 . In this example, ONU 106 and TVs 107 are interconnected via coaxial (COAX) cable.
As indicated above, the desired ranging delay is effected by obtaining a measure of loop delay between an ONU 106 and its associated OLC 104 . This is realized, in this example, my employing a unique out-of-band ranging arrangement, in accordance with the invention.
To this end, ONU 106 includes an ONU ranging delay unit 200 including, in this example, apparatus as shown in FIG. 2 . Specifically, shown is PSPON transceiver 201 including PSPON interface 202 for interfacing PSPON optical fiber 111 , in well known fashion. Incoming optical signals from PSPON fiber 111 are supplied to optical/electrical (O/E) converter 203 where they are converted into electrical signals. In turn, the incoming electrical signals are supplied to controller 205 and, therein, to input interface 206 . Outgoing electrical signals are converted via electrical/optical (E/O) converter 204 to optical signals. In turn, the outgoing optical signals are supplied via PSPON interface 202 to PSPON optical fiber 111 .
Controller 205 includes central processor unit (CPU) 208 which may be a microprocessor, memory 209 , user input/output (I/O) units 210 , status register 211 , assigned time slot register 212 , start of down-stream frame register 213 , ranging delay register 214 , transmit burst control unit 215 and data first-in-first-out (FIFO) register 221 . Units 206 , 208 through 215 and 221 are interconnected via bus 207 . A power ON status signal is supplied to one input of AND gate 216 , while an initialized status signal is supplied to an inhibit input of AND gate 216 , both from status register 211 . Thus, And gate 216 yields a high state output when power ON is a high state and initialized is a low state. This high state output from AND gate 216 is supplied via OR gate 217 to enable ranging tone oscillator 220 to supply as an output the desired out-of-band ranging tone. In this manner the ranging state is effected. Again, in this example, the out-of-band ranging tone is generated at 466.56 MHz. This ranging tone is supplied to summer 222 and, thereafter, to PSPON 111 via E/O 204 and PSPON interface 202 .
A verify status signal is supplied from status register 211 to an input of AND gate 218 , while a transmit burst control signal is supplied from transmit burst control 215 to a second input of AND gate 218 . And gate 218 is controlled via the supplied signals to enable transmission of the out-of-band ranging tone during the assigned time slot to effect the verify state.
An active status signal is supplied from status register 212 to an input of AND gate 219 , the transmit burst control signal is supplied to a second input of AND gate 219 and a clock (CLK) signal is supplied to a third input of AND gate 219 . And gate is controlled via the supplied signals to control supplying the CLK signal to data FIFO 221 , thereby enabling the active data state. The data output from data FIFO 221 is supplied via summer 222 , E/O 204 and PSPON interface 202 to PSPON fiber III.
Operation of ONU ranging delay unit 200 is described below in conjunction with the flow chart of FIG. 4 .
FIG. 3 shows, in simplified block diagram form, details of an OLC ranging delay unit employed in practicing the invention. Specifically, shown is PSPON transceiver 301 including PSPON interface 302 for interfacing PSPON optical fiber 110 , in well known fashion. Incoming optical signals from PSPON fiber 110 are supplied to optical/electrical (O/E) converter 303 where they are converted into electrical signals. In turn, the incoming electrical signals are supplied to diplexer 306 , which extracts and supplies the in-band data signals to controller 305 and, therein, to I/O 308 . Diplexer 306 also extracts the out-of-band ranging tone and supplies it to tuned detector 307 . A high state output from detector 307 indicating the reception of the out-of-band ranging tone is supplied to one input of AND gate 316 .
Controller 305 includes I/O 308 , CPU 310 , which may be a microprocessor, memory 311 , enable register 312 , reset register 313 , clock 314 and ranging delay register 315 , all interconnected via bus 309 .
An output from enable register 312 is supplied to a second input of AND gate 316 and when it is a high state signal and the high state tone detection signal is present, AND gate 316 supplies an enable high state signal to ranging delay timer 317 . This enables timer 317 to count the clock output from clock 314 . As described below, when the out-of-band ranging tone is no longer detected the count in timer 317 represents the loop delay for a particular ONU associated with this OLC. The loop delay interval is supplied to ranging delay register 315 . A reset signal from reset register initializes ranging delay timer 317 .
Operation of OLC ranging delay unit 300 is described below in conjunction with the flow chart of FIG. 5 .
FIGS. 4A, 4 B and 4 C when connected A—A, B—B, C—C, D—D, E—E and F—F form a flow chart illustrating the steps in the ranging delay procedure of the ONU ranging delay unit of FIG. 2 . The ONU 106 ranging delay procedure is begun at 401 . Thereafter, step 402 tests to determine if ONU power is ON. If the test result is NO, step 402 is repeated until it yields a YES result. Then, step 403 tests to determine if the ONU is initialized. If the test result is YES, ONU 106 is in the initialized state and control is transferred to step 408 . If the test result in step 403 is NO, ONU 106 has not been initialized and is in the ranging state, and step 404 causes the out-of-band ranging tone to be transmitted. Again, in this example, the ranging tone is generated at 466.56 MHz, which is outside the normal in-band message transmission band. Step 405 tests to determine if a broadcast message as been received by ONU 106 . If the test result is NO, step 405 is repeated until a YES result is obtained. Note that the received broadcast message includes an instruction for the ONU to stop transmission of the ranging tone and that the ONU assume an ID. Then, step 406 causes the transmission of the ranging tone to be terminated. Step 407 sets the ID for ONU 106 to ONUID. Step 408 tests to determine if a unicast message has been received including the ranging delay determined for the ONUID, namely, “F” which is the number of frames, “B” which is the number of bytes and “b” which is the number of bits. In this example, F is a 0, 1 or 2 frame, B is between 0 and 2429 bytes, inclusive, and b is between 0 and 7 bits, inclusive. Step 409 causes the ranging delay for the ONUID to be set to the received values of F, B and b. Step 410 tests to determine if the up-stream time slot assignment for the ONUID has been received. If the test result is NO, step 410 is repeated until it yields a YES result indicating that the assigned time slot identified by its offset and size has been received. The offset is the number of bytes from the start of each frame and the size is the time slot length in bytes. Step 411 indicates that the unicast message to this ONUID including the assigned time slot has been received and causes the assigned time slot to be set to the received offset and size. Then, this ONU is in the verify state and step 412 causes the transmission of the out-of-band tone in the assigned time slot. Then, step 413 tests to determine if a unicast message to this ONUID has been received. If the test result is NO, step 413 is repeated until it yields a YES result. Step 414 tests to determine if the received message includes the ranging delay for this ONUID. If the test result is YES, step 415 causes the ranging delay for this ONUID to be set to the received F, B and b. Note that in the verify state, the ranging delay value may be fine tuned through the reception of new values for F, B and b. Thereafter, steps 412 through 415 are iterated until step 414 yields a NO result. Then, step 416 causes the ONU to be set to the data state. Step 417 causes the in-band data burst to be transmitted in the assigned time slot. This is the ONU active data state. Step 418 tests to determine if a unicast message for this ONUID has been received. If the test result is NO, step 418 is repeated until it yields a YES result, if at all. Then, step 419 tests to determine if the received unicast message is switch to verify state. If the test result is YES, the ONU reenters the verify state, control is transferred to step 412 and steps 412 through 419 are iterated until step 419 yields a NO result. Note that the verification state may be reentered because of some particular event being detected in ONU 106 , for example, power failure, or from a control message from OLC 104 . Thereafter, step 420 causes the assigned time slot to be set to zero (0). This is the ONU idle state. Step 421 causes the ONU to be set to poll for status timer. In this example, the time-out interval for the status timer is one (1) second. Then, step 422 tests to determine if the status timer has timed-out. If the test result in step 422 is YES, control is transferred to step 408 and appropriate ones of steps 408 through 422 are iterated until step 422 yields a NO result. Step 423 tests to determine if a unicast message for this ONUID has been received. If the test result is NO, steps 422 and 423 are repeated until either of them yields a YES result. If step 422 yields a YES result, operation is as described above. If step 423 yields a YES result, step 424 tests to determine if the received unicast message is switch to verify state. If the test result is YES, control is transferred to step 412 and appropriate ones of steps 412 through 424 are iterated until step 424 yields a NO result. Then, step 425 causes the assigned time slot to be set to a new assigned time slot, namely, a new offset and size. Thereafter, control is transferred to step 417 , appropriate ones of steps 417 through 425 iterated and if necessary appropriate ones of steps 408 through 425 are iterated until the ONU again enters the active data state, i.e., its normal operational state.
Thus, it is seen that if the polled ONC responds with transmission of the out-of-band ranging tone, that is an indication that the ONU is already in the verify state and the associated OLC treats the ONU as though it was verifying ranging. If the out-of-band tone is properly aligned in the assigned time slot, the ONU is caused to switch to the active data state.
Additionally, requiring an idle ONU to be polled, enables system operations to distinguish among an idle ONU, a power outage and a relocated ONU, as described below in relationship to the operation of the OLC ranging unit.
FIGS. 5A and 4B when connected A—A and B—B form a flow chart illustrating the steps in the ranging delay procedure of the OLC ranging delay unit of FIG. 3 . The OLC ranging delay procedure is started in step 501 . Thereafter, step tests to determine if a ranging tone has been received by the OLC from ONUID. If the test result is NO, step 502 is repeated until it yields a YES result. Then, step 503 causes a message to be transmitted to the ONUID causing it to stop transmitting the ranging tone and to assign the ONU ID as ONUID. Step 504 causes the ranging delay timer to be set. Then, step 505 tests to determine if the transmission of ranging tone has stopped. If the test result is NO, step 505 is repeated until it yields a YES result. Step 506 causes the ranging delay timer to be stopped. The accumulated time interval of the ranging delay timer is the ranging delay for the ONUID. That is, the interval between the terminate transmission of ranging tone message is sent by the OLC and detection that it has terminated is the loop delay for the ONUID. Then, step 507 causes the transmission of a unicast message to the ONUID including the determined ranging delay, namely, F, B and b. Step 508 causes the transmission of a message to the ONUID including assignment of an up-stream time slot, namely, offset and size. Step 509 tests to determine if an out-of band ranging delay tone presently being received in the assigned time slot is aligned with the assigned time slot. If the test result is NO, step 510 causes a message to be transmitted to the ONUID to adjust the ranging delay of the ONUID. Thereafter, step 509 again tests to determine if the out-of-band tone is aligned with the assigned time slot as adjusted. If the test result is NO, steps 510 and 509 are iterated until step 509 yields a YES result. Then, step 511 causes a message to be transmitted to the ONUID indicating that the ONU switch to the active data state. Step 512 tests to determine if up-stream data is being received from any ONU associated with this OLC. If the test result is NO, step 512 is repeated until it yields a YES result. Then, step 513 tests to determine if the data is in the proper time slot assigned to ONUID transmitting the data. If the test result is YES step 513 is repeated until it yields a NO result. Step 514 tests to determine if there is a loss of signal. If the test result is YES, step 515 causes a message to be transmitted to the ONUID switching it to the verify state. Then, control is transferred to step 508 and appropriate ones of steps 508 through 515 are iterated until step 514 yields a NO result. Step 516 tests to determine if there is a large time slot drift. If the test result is YES, control is transferred to step 515 and appropriate ones of steps 508 through 516 are iterated until step 516 yields a NO result. Then, step 517 tests to determine if there is a severe unadjustable problem. If the test result is YES, step 518 causes a message to be transmitted to the ONUID causing it to enter the uninitialized state. Returning to step 517 , if the test result is NO, step 519 tests to determine if the time slot drift is minor. If the test result is NO, control is returned to step 512 and appropriate ones of steps 512 through 519 are iterated, and if necessary appropriate ones of steps 508 through 519 are iterated, until step 519 yields a YES result. Then, step 520 causes a message to be transmitted to the ONUID including a new ranging delay, namely, a new F, B and b.
Note that if a power outage renders one or more ONU associated with the OLC to be inoperative, a so-called “self-aware” system must re-establish a correct state of operation of the one or more associated ONUs automatically when power is restored. An ONU that loses power stops transmitting data and reverts to the verify state. The associated OLC detects the “loss of signal” from the one or more ONU that lost power, and deletes them from a list of up-stream time slot assignments. Then, the list of ONCs that are not in the active state are polled, as described above. Consequently, when power is restored, the ONUs are brought on-line one at a time.
If an ONU is moved or otherwise disconnected, it is placed into the un-iniatilized state by clearing its ranging delay. When the ONU is reconnected, it will automatically initiate the ranging procedure, as described above.
In certain instances an ONU can be disconnected or moved without prior knowledge of the system operators. For example, an ONU can be disconnected and, then, reconnected at some other location without notification to the system operators. When the ONU is disconnected it loses power and switches to the verify state, as described above. When an attempt is made to reconnect and reactivate the ONU, however, its out-of-band ranging tone will be positioned incorrectly in the up-stream frame. That is, the out-of-band tone will be in the wrong time slot. Because of this, the associated OLC generates a message and send it to the ONU, which resets the ONC to the un-initialized state. This, in turn, results in the automatic activation of the ranging procedure. That is, the ONU is treated as a newly connected ONU.
As shown, out-of-band ranging has no impact on up-stream bandwidth management, i.e., it is non-intrusive. Additionally, the probability of a “ranging” collision is minimized because an ONU ranges immediately upon it being connected to the network and powered on. Moreover, an out-of-band ranging tone offers additional capabilities for non-intrusive verification, handling power outages, switching an ONU to a low power standby state and ONU location moves, as described above.
The above-described embodiments are, of course, merely illustrative of the principles of the invention. Indeed, numerous other methods or apparatus may be devised by those skilled in the art without departing from the spirit and scope of the invention. | An out-of-band ranging technique is automatically initiated at a customer premises equipment unit when the equipment is installed, when power is restored after a power failure or interruption, upon verification of the equipment, upon reconnection after a disconnection of the equipment or the like. To this end, an out-of-band tone is employed that is automatically transmitted when the customer premises equipment that transmits the TDMA signal is powered ON, or transmitted in response to a specific command generated locally or remotely. Specifically, when ranging is being effected the customer premises equipment generates and transmits the out-of-band ranging tone until a message is received from a remote terminal indicating that the transmission of the ranging tone be terminated. The loop delay being determined is the delay interval between transmission of the termination message and detection that transmission of the ranging tone has terminated. Then, a message is transmitted to the customer premises equipment that contains the ranging delay interval that is to be used in all future transmissions to the remote terminal. In one embodiment of the invention, the customer premises equipment automatically switches to an idle standby state when the remote terminal removes its upstream transmission slot. In the standby state, the customer premises equipment is still capable of receiving data and is periodically polled by the remote terminal assigning it an upstream transmission slot. If a customer premises equipment in the standby state is not polled during a predetermined interval, it automatically switches to a verification state. Additionally, if the customer premises equipment does not respond when polled, the remote terminal transmits it a message putting it in the verification state. If a polled customer premises equipment responds with an out-of-band tone, which indicates that it is in the verification state, the remote terminal treats it as though it is verifying ranging. If the out-of-band tone is properly aligned, the customer premises equipment is switched to an active state. | 7 |
FIELD
[0001] The disclosure relates to methods and systems for operating a riser in an offshore hydrocarbon production facility, the riser being formed of flexible pipe having a central bore and an annulus containing multiple functional layers. More particularly, the disclosure relates to methods and systems for circulating fluids in the annulus of a flexible pipe riser.
BACKGROUND
[0002] Engineered flexible pipe is frequently used in riser applications in offshore hydrocarbon production facilities which convey hydrocarbon products from a subsea well to a topsides production platform or vessel. Such flexible pipe is formed of multiple layers, each layer designed for a specific function. In general, the innermost layer of the multiple layers is the carcass layer, made of corrosion resistant material, designed to resist collapse of the flexible pipe. Surrounding the carcass is a polymeric sealant layer or pressure sheath which is extruded around the carcass and sealed at flexible pipe end fittings to contain fluid within the bore. Surrounding the polymeric sealant layer is an annulus containing a number of metallic armor layers designed to impart strength against tensile loading (e.g. armor wires) and internal pressure loading (e.g. pressure armor). Surrounding these layers is another polymeric sealant layer or external sheath designed to avoid external sea water ingress into inner layers of the flexible pipe, which acts as an outer protective layer. The space between the two polymeric sealant layers is referred to as “the annulus.” Typically, the annulus contains one or two layers of circumferentially oriented steel members (referred to as pressure armor layers) designed to provide radial strength and burst resistance due to internal pressure. Surrounding the pressure armor layers are two or four layers of helically wound armor wires (referred to as armor wire layers) designed to provide tensile strength in the axial direction.
[0003] Flexible pipe is terminated at each end by an end fitting which incorporates a flange for mating with other flanges. In use, flexible pipe risers are suspended from an offshore hydrocarbon production platform or host facility, thus placing high tensile loads on the armor wire layers. The loads along the riser are amplified due to the effects of environmental conditions and associated motions of the platform or host facility to which the riser is connected.
[0004] Within the bore of the flexible pipe, in addition to hydrocarbon products, other components including hydrogen sulfide, carbon dioxide and water may be present. These other components can diffuse through the first polymeric sealant layer (pressure sheath) to the annulus. These components, hydrogen sulfide in particular, as well as water vapor, can accumulate within the annulus and eventually lead to corrosion of the steel wires therein via mechanisms including hydrogen induced cracking and sulfide stress cracking. Additionally, the annulus can be flooded with seawater due to damage of the outermost layer leading to corrosion of the armor wires. As noted, the armor wires in the flexible riser are particularly subject to dynamic cyclic loads, which can result in corrosion fatigue of the metallic armor wires in the annulus. Corrosion of the metallic wires in this region makes these wires particularly vulnerable to corrosion fatigue and potential acceleration of failure mechanism.
[0005] It would be desirable to provide a way to prevent or reduce corrosion of the armor wires and other steel elements within the annulus of flexible pipe used in risers and in other dynamic applications.
SUMMARY
[0006] According to one embodiment, a method is provided for circulating fluid within the annulus of a flexible pipe riser in an offshore hydrocarbon production facility. The method includes pumping the fluid into a closed loop at sufficient pressure to cause fluid to circulate through the loop. The loop includes the annulus of a flexible pipe riser terminating at a topsides riser end fitting at a production platform or an offshore vessel and at a subsea riser end fitting at a subsea location, and at least one umbilical tube within a subsea umbilical in fluid communication with the subsea riser end fitting, and terminating at an umbilical end fitting at the platform or vessel in fluid communication with the annulus.
[0007] In another embodiment, a system is provided for use in an offshore hydrocarbon production facility. The system includes at least one subsea umbilical tube terminating at a production platform or offshore vessel and at a subsea location for conveying a fluid; at least one flexible pipe riser terminating at a production platform or offshore vessel and at a subsea location, wherein the flexible pipe riser includes an annulus in fluid communication with the at least one umbilical tube; end fittings at each terminal location of the flexible pipe riser, wherein each end fitting comprises a port in fluid communication with the annulus; a connector for placing the at least one umbilical tube in fluid communication with the port of the end fitting at the subsea location; and a pump for pumping fluid to circulate the fluid within a closed loop comprising the annulus and the at least one umbilical tube.
[0008] In yet another embodiment, a method for retrofitting a riser system in an existing offshore hydrocarbon production facility is provided. The method includes disconnecting from a topsides venting system a port of an existing topsides end fitting of a flexible pipe riser including an annulus, wherein the flexible pipe riser has a topsides end fitting and a subsea end fitting having a venting port check valve in fluid communication with the annulus; and removing the venting port check valve from the subsea end fitting. The method further includes providing a recirculation kit on the production platform or offshore vessel, the recirculation kit including a fluid storage tank having a tank inlet and a tank outlet; a pump having a pump inlet in fluid communication with the tank outlet and a pump outlet; and piping for fluid connection between the tank outlet and the pump inlet. The port of the flexible pipe riser topsides end fitting is connected to the recirculation kit. A subsea end of an umbilical tube is connected to a port in the subsea end fitting of the flexible pipe riser. Finally, a topsides end of the umbilical tube is connected to the recirculation kit thereby establishing a closed loop including the annulus, the umbilical tube and the recirculation kit.
DESCRIPTION OF THE DRAWINGS
[0009] These and other objects, features and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings where:
[0010] FIGS. 1A-1I illustrate systems for circulating fluid within the annulus of a flexible pipe riser in an offshore hydrocarbon production facility.
[0011] FIG. 2 illustrates a method for retrofitting a riser system in an existing offshore hydrocarbon production facility.
DETAILED DESCRIPTION
[0012] According to methods and systems of the present disclosure, the incidence of corrosion over time of armor wires and other steel elements (e.g. pressure armor layer(s)) within the annulus of flexible pipe, such as those used in flexible pipe risers in offshore hydrocarbon production facilities, can be reduced.
[0013] The incidence of corrosion of the armor wires and related problems such as corrosion fatigue can be reduced by circulating a corrosion-inhibiting or a fluid containing surface passivating agents or other additives within the annulus so that the fluid flows in the interstices between the armor wires and other steel elements. A gas-flushing fluid to flush H 2 S, CO 2 , water vapor, etc. from the annulus can also be used. The fluid is referred to interchangeably herein as “buffer fluid,” “flushing fluid,” or simply “fluid.” The fluid can be circulated either continuously or intermittently. The fluid contacts and encompasses the armor wires and other steel elements, protecting them from corrosion. In another embodiment of the present disclosure, rather than or in addition to buffer fluid, image sensitive-materials can be circulated within the annulus of the flexible pipe riser, thus allowing the annulus to be imaged using known techniques.
[0014] The buffer fluid is circulated in a closed loop which includes the annulus of the flexible pipe riser and at least one umbilical tube within a subsea umbilical. Referring to FIG. 1A , a system is illustrated according to one embodiment in which a production platform 1 is connected to a flexible pipe riser 10 (at topsides end fitting 12 ). The flexible pipe riser 10 terminates on the seabed 3 at a touchdown point where end fitting 14 rests on the seabed 3 . End fitting 14 is connected to an end fitting 15 of a flow line 60 . Buffer fluid 34 is stored in fluid storage tank 30 on the production platform 1 . The fluid 34 is taken from the tank 30 , through conduit 36 and pumped by pump 32 into the annulus of flexible pipe riser 10 . Subsea umbilical 70 is connected to the flexible pipe riser end fitting 14 at port 72 . Fluid pressure drives the fluid 34 to rise through umbilical 70 to return to the tank 30 on the platform 1 . Arrows 34 a indicate the direction of flow of the buffer fluid within the closed loop.
[0015] FIG. 1E is a longitudinal cross-section of the flexible pipe riser 10 illustrating a side view of the annulus 40 surrounding bore 16 having produced well fluids containing hydrocarbons 38 flowing there through. The armor wires and other steel elements within the annulus are represented by 50 . FIG. 1F is an exploded view of flexible pipe riser 10 showing each of the layers of the flexible pipe. Innermost is the bore 16 within the carcass 52 . The carcass 52 is surrounded by pressure sheath 54 which is in turn surrounded by the annulus 40 . The annulus 40 which includes layers 50 , including pressure armor layer 56 , inner tensile armor wire layer 60 and outer tensile armor wire layer 62 . Surrounding the outer tensile armor wire layer is the external sheath 11 . The cross-section of the flexible pipe is shown in FIG. 1G . FIG. 1H is an expanded view of the wall of the flexible pipe, showing each of the layers previously described as well as the interstitial spaces 90 there between. Within these spaces, buffer fluid 34 flows.
[0016] FIG. 1I illustrates the subsea end fitting 14 of the flexible pipe riser 10 according to one embodiment. As shown in this embodiment, flexible pipe riser 10 is attached to end fitting 14 by bolts 84 . The end fitting 14 , including bore 86 therein, is designed to securely attach to the end of the flexible pipe and allow for attachment to an adjacent fitting. End fitting 14 also includes a port 72 in fluid communication with the annulus 40 of flexible pipe riser 10 . The umbilical 70 can be connected to port 72 which can be the location of a venting valve in a typical end fitting, thereby providing fluid communication between the umbilical 70 and the annulus 40 . While the figure shows 70 as a single umbilical tube, it should be understood that fluid 34 can flow through one or more individual umbilical tubes within a multicomponent subsea umbilical.
[0017] FIG. 1B illustrates an alternative embodiment similar to that of FIG. 1A in which the direction of buffer fluid flow in the closed loop, as indicated by 34 b , is reversed. In this embodiment, the fluid 34 is pumped from the storage tank 30 , through conduit 36 and pump 32 into at least one umbilical tube within a subsea umbilical 70 . As described above, umbilical 70 is connected via port 72 to flexible pipe riser end fitting 14 , such that fluid 34 passes from the umbilical 70 to the annulus 40 of the flexible pipe 10 . Fluid pressure drives the fluid 34 to rise through the annulus 40 to return to the tank 30 on the platform 1 .
[0018] FIG. 1 illustrates an alternative embodiment similar to that of FIG. 1A in which fluid 34 flows through one or more individual umbilical tubes within a multicomponent subsea umbilical 70 . FIG. 1D shows the multicomponent subsea umbilical 70 in cross-section. Among the components within the umbilical 70 are individual umbilical tubes 71 through which fluid 34 flows. As shown in FIG. 1C , fluid 34 is pumped into umbilical 70 via individual umbilical tubes 71 . Umbilical 70 terminates at a distribution unit 76 which can be any suitable manifold structure such as an umbilical terminal assembly (UTA). From the distribution unit 76 , a second umbilical 70 ′ can carry controls to various systems or equipment in the hydrocarbon production facility. One or more flying leads 74 can be used to transmit fluid 34 to flexible pipe riser end fittings 14 (other flexible pipe riser end fittings not shown). In this way, buffer fluid 34 can be circulated through multiple risers within a single hydrocarbon production facility. FIG. 2 illustrates a method for retrofitting an existing riser system according to one embodiment. In an existing offshore hydrocarbon production facility 100 , a topsides structure 106 mounted on a platform receives produced well fluids from flexible pipe riser 10 , connected at 108 , and sends the well fluids for further processing indicated by Production 102 . Port 120 on topsides end fitting of riser 10 is typically connected to a venting system (not shown) for venting gases from the annulus of the flexible pipe riser 10 . At a subsea location, riser 10 terminates at subsea riser end fitting 110 where connection is established with flow line 60 . Flanges 114 and 116 connect subsea riser end fitting 110 to subsea flow line end fitting 118 . Subsea riser end fitting 110 typically has one or more venting port check valve(s) 113 which are in fluid communication with the annulus of the flexible pipe 10 .
[0019] In order to retrofit the existing system, one of the venting port check valves 113 is removed from the subsea riser end fitting 110 and an umbilical 70 is connected to the port in its place. Port 120 on topsides end fitting of riser 10 is disconnected from the venting system (not shown). A recirculation kit 112 containing a fluid storage tank and pump are provided at the platform. The kit is connected to the port 120 (via line 122 as shown) and to the umbilical 70 thus establishing a closed loop including the annulus of the flexible pipe riser 10 , the umbilical 70 and the recirculation kit 112 through which fluid can be circulated. The kit can be connected so that the port of the flexible pipe riser topsides end fitting is connected to the pump outlet and the topsides end of the umbilical tube is connected to the tank inlet. Alternatively, the kit can be connected so that the port of the flexible pipe riser topsides end fitting is connected to the tank inlet and the topsides end of the umbilical tube is connected to the pump outlet.
[0020] Where permitted, all publications, patents and patent applications cited in this application are herein incorporated by reference in their entirety, to the extent such disclosure is not inconsistent with the present invention.
[0021] Unless otherwise specified, the recitation of a genus of elements, materials or other components, from which an individual component or mixture of components can be selected, is intended to include all possible sub-generic combinations of the listed components and mixtures thereof. Also, “comprise,” “include” and its variants, are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that may also be useful in the materials, compositions, methods and systems of this invention.
[0022] From the above description and appended drawings, those skilled in the art will perceive improvements, changes and modifications, which are intended to be covered by the appended claims. | Disclosed is a process and system for circulating fluid within the annulus of a flexible pipe used in a riser in an offshore hydrocarbon production facility. Fluid, such as corrosion inhibitors, can be circulated in a closed loop which includes the annulus of the riser terminating at a platform or floating vessel, a fluid storage tank located on the platform or vessel and an umbilical tube terminating at the platform or vessel and at a subsea location. Use of the system to flow the fluid through the annulus can prevent or reduce corrosion of the steel members within the annulus and increase the fatigue life of the riser. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The current application claims priority to U.S. Provisional Application No. 60/952,161, filed Jul. 26, 2007, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The current invention is directed to a mechanism for preventing the back-out of a screw; and more particularly for a mechanism for preventing the back-out of screws in a bone fixation device.
BACKGROUND OF THE INVENTION
[0003] The use of fixation plates for the treatment of bone fusions and fixations has grown more prevalent over the past decade. Indeed, while early procedures using fixation plates were generally restricted to long bones and lower lumbar levels of the spine, fixation plates have increasingly found applications in other bone instrumentation such as in the cervical spine.
[0004] A typical bone fixation plate is provided with a plurality of bores therethrough. A corresponding plurality of fastener members, typically bone screws having a headed portion and a threaded shaft, are provided to secure the plate to the bone, or bones, to be fixated. A common problem with the use of fixation plates, regardless of their location, is the tendency of the bone screws to “back-out” of the underlying bone. This problem is particularly prevalent in areas of high stress such as the spine. Given the delicate nature of the spine, anything that may result in post-operative complications, such as plate movement or revision, can seriously endanger the patient's long-term prognosis.
[0005] Bone fixation systems have employed various techniques in an attempt to overcome the problem of screw back-out. Current techniques rely either on the use of specially designed bone screws, are irreversible, or require special procedures that could complicate the surgery. For example, U.S. Pat. No. 5,275,601 discloses a self-locking bone fixation system wherein the heads of the bone screws are frustoconical in shape and have a directionally corrugated outer surface; U.S. Pat. No. 5,269,784 discloses a threaded screw nut that threadingly engages a portion of the bone screw to thereby secure the bone screw to the fixation plate; U.S. Pat. No. 4,484,570 discloses a bone fixation system wherein the heads of the bone screws are hollow and expandable; and U.S. Pat. No. 5,578,034 discloses a bone fixation system in which the plates are heated after insertion, thereby expanding a retaining mechanism into place around the screw.
[0006] All of the cited prior art systems suffer from one or more undesirable drawbacks. First, some of these prior art systems rely on a retainer that itself uses a threaded connection to maintain the bone screws in position, meaning that the problem of screw back-out still exists. Second, several of these systems permanently seal the screw into place, rendering revision or alteration of the plate very difficult. Finally, the requirement that one use a particular, specially designed proprietary bone screw to prevent back-out limits a surgeon's ability to choose the best-engineered screw for a particular application because the proprietary bone screw may have inappropriate specifications such as thread pitch. Accordingly, a bone fixation system incorporating a mechanism for preventing screw back-out that is simple to use and revise and can be operated with any standard bone screw would be desirable.
SUMMARY OF THE INVENTION
[0007] The current invention is generally directed to a screw back-out prevention device. The device generally comprises at least one moveable element and a rotary activation element that interlockingly engages such that the rotation of the rotary activation element causes the at least one moveable element to advance into a lock position where the back-out of the screw is prevented.
[0008] In one embodiment of the screw back-out prevention device of the current invention the moveable plates and the rotary element are engaged together via an interlocking pin and curvilinear slot.
[0009] In another embodiment the screw back-out prevention device of the current invention operates in cooperation with a bone fusion device. In such an embodiment, the device may either be integrated into the body of the fusion device or attached to a top surface of a bone fusion device.
[0010] In still another embodiment of the screw back-out prevention device of the current invention the rotary activation element is removably engaged to the at least one moveable plate.
[0011] In yet another embodiment the screw back-out prevention device of the current invention operates by covering the exposed surface of the head of the screw when in the lock position.
[0012] In still yet another embodiment the screw back-out prevention device of the current invention operates by engaging a portion of the screw in the lock position. In such an embodiment, the device of the current invention either directly or indirectly engages the screw. In the embodiment of the current invention where the device indirectly engages the screw it may do so through a retention ring that may either be integrated into a screw or disposed within the bone fusion plate itself.
[0013] In still yet another embodiment the screw back-out prevention device of the further invention operates through at least one cam designed to rotate into locking engagement with at least a portion of the screw.
[0014] In still yet another embodiment, the screw back-out prevention device of the current invention is formed from a material selected from the group consisting of Ti, stainless steel and NiTi.
BRIEF DESCRIPTION OF THE FIGURES
[0015] The description will be more fully understood with reference to the following figures, which are presented as exemplary embodiments of the invention and should not be construed as a complete recitation of the scope of the invention, wherein:
[0016] FIGS. 1 a and 1 b provide schematic diagrams of a screw back-out prevention device in accordance with the current invention;
[0017] FIGS. 2 a and 2 b provide top and side view schematic diagrams of a spinal fixation plate incorporating a screw back-out prevention mechanism in accordance with one exemplary embodiment of the current invention;
[0018] FIG. 3 shows schematic diagrams of the individual components of the screw back-out prevention mechanism shown in FIGS. 2 a and b;
[0019] FIGS. 4 a and 4 b provide top and side view schematic diagrams of a spinal fixation plate incorporating a screw back-out prevention mechanism in accordance with one exemplary embodiment of the current invention;
[0020] FIG. 5 shows schematic diagrams of the individual components of the screw locking/retention mechanism shown in FIGS. 4 a and b ; and
[0021] FIGS. 6 to 9 provide schematic diagrams of the various mechanisms of operation of several exemplary embodiments of the screw back-out prevention mechanism in accordance with the current invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The current invention is directed generally to a mechanism for preventing screw back-out in a bone fixation system. The back-out prevention device of the current invention uses a plurality of moveable components to directly or indirectly engage the screws of the bone fixation system to either lock or retain the screws into a specific position within the overall bone fixation system.
[0023] A generic schematic of the screw back-out prevention device is provided in FIG. 1 . As shown, the device ( 10 ) generally comprises at least one moveable component ( 12 ) that can be compelled either directly or indirectly to lock or retain the screw ( 14 ) into a desired position by the operation of a second rotary activation element ( 16 ).
[0024] An exemplary embodiment of the screw back-out prevention system of the current invention is shown schematically in FIGS. 2 and 3 . In this first exemplary embodiment, the device ( 20 ) comprises two moveable plates ( 22 ) and a rotary component ( 24 ) for engaging and moving the moveable plates into and out of screw retention/locking alignment. In the embodiment shown best in FIG. 3 , the plates ( 22 ) have a pair of pins ( 26 ) that are designed to engage a pair of cooperative curvilinear slots ( 28 ) on the rotary component ( 24 ). As shown in FIGS. 2 a and 2 b , when the rotary element ( 24 ) is rotated the curvilinear slots ( 28 ) apply a force to the pins ( 26 ), which in turn direct the movement of the plates. The direction and distance of the movement of the plates ( 22 ) are controlled by the shape of the curvilinear slots ( 28 ) and the direction of rotation applied to the rotary component ( 24 ). As shown in FIGS. 2 and 3 , in the current embodiment the counter-clockwise rotation of the rotary component ( 24 ) imparts a motion in the outward direction to the moveable plates ( 22 ). It should be understood, however, that the direction imparted can be reversed without altering the function of the current invention.
[0025] Although the embodiment shown in FIGS. 2 and 3 are designed such that the rotary component ( 24 ) is slotted and the moveable plates ( 22 ) have pins, an opposite arrangement, as shown in FIGS. 4 and 5 would be equally acceptable. Specifically, as shown in FIG. 5 , in a second exemplary embodiment of the device the pins ( 26 ) are disposed on the rotary component ( 24 ) and the curvilinear slots ( 28 ) are disposed on the moveable plates ( 22 ). Moreover, although only single pin/slot combinations are shown, it should be understood that any number of pins may be made to engage the curvilinear slots of the rotary component.
[0026] FIGS. 1 to 5 show a number of schematic diagrams of exemplary embodiments of the back-out prevention device of the current invention and the arrangement of the main components thereof; however, it should be understood that the manner in which the moveable components of the device prevent screw back-out may themselves take a number of different forms. Schematic diagrams showing exemplary mechanisms are provided in FIGS. 6 to 9 .
[0027] FIGS. 6 a and 6 b provide schematic diagrams showing the mechanism of operation of a first embodiment of the screw back-out prevention device of the current invention. In this embodiment the moveable plate ( 30 ) is positioned relative to the screw ( 32 ) such that when moved into the screw retention position ( FIG. 6 b ) the plate covers the head of the bone screw, thereby preventing the screw from backing out of the bone fixation plate.
[0028] FIGS. 7 a and 7 b provide schematic diagrams of the mechanism of operation of a second embodiment of the screw back-out prevention device of the current invention. In this embodiment, the moveable plate ( 34 ) directly engages an interlock portion of the screw ( 36 ) specifically designed for such a function.
[0029] FIG. 8 provides a schematic diagram of the mechanism of operation of a third embodiment of the screw back-out prevention device of the current invention. In this embodiment, the moveable plate ( 40 ) engages a retention ring ( 42 ) positioned either on the screw itself or within the bone fixation plate. The retention ring ( 42 ) then directly engages an interlock portion of the screw ( 44 ) specially designed for such a function.
[0030] Although in the embodiments shown in FIGS. 7 and 8 the interlock portion of the screws ( 36 & 44 ) take the form of slots designed to interact with the moveable plate or retention ring, it should be understood that the engagement portion may take any shape or form suitable to receive a portion of the moveable plate thereby securing the screw into position. Examples of suitable engagement portions may include, for example, a hole and pin.
[0031] Finally, FIG. 9 provides a schematic diagram of the mechanism of operation of a fourth embodiment of the screw back-out prevention device of the current invention. In this embodiment, the moveable plate ( 46 ) engages a cam mechanism ( 48 ) that rotates when activated by the moveable plates to engage a portion of the screw ( 50 ) thereby locking the screw into place.
[0032] Regardless of the actual design of the screw back-out prevention device and its manner of operation, it should be understood that a further locking mechanism may be included in its design to ensure that once engaged in the locked position the moveable elements cannot be inadvertently moved out of said position. In a preferred embodiment, the locking mechanism is designed to be reversibly engaged such that the back-out prevention device can be unlocked if necessary, such as, for example, for revision or removal of the bone fusion system. However, such a locking mechanism may take any suitable form, including, for example, a blocking element inserted between the moveable plates to prevent movement in the reverse direction, a set screw, pin, etc.
[0033] Although all of the above figures and the accompanying descriptive text, have focused only on the arrangement of the main components of the screw back-out prevention device of the current invention, it should be understood that the device can either be integrated into a bone fixation plate, such as a spinal fusion plate, or attached to the top of a plate such that the it can retain or lock the screws of the bone fixation plate into place. If the screw back-out prevention device is attached to the top of a bone fixation plate, the attachment may be either permanent or temporary, i.e., the device may be integrally affixed to the plate such as by welding, or can be removably attached such as by screws or other removable fasteners. In addition, the rotary component may either be permanently integrated with the moveable plates, or may be a separate tool that is engaged with the moveable plates only during the operation of the device. In such an embodiment, the rotary component would be engaged with the posts or curvilinear slots of the moveable plates, depending on the device's design, the moveable plates would be engaged to lock the bone fixation screws into place, and then the rotary component would be removed.
[0034] As has been previously discussed, the device can be incorporated into or added on to any conventional bone fixation plate that uses bone screws as the means of attaching the plate to the bone. However, the device may also be used in other building, construction or home use/repair systems and devices where screw back-out may be an issue.
[0035] The components of the screw back-out prevention device of the current invention, and any bone fixation plate into which the device is incorporated, may be formed of any conventional surgical material. Exemplary conventional materials include, for example, titanium and stainless steel. In addition, portions of the device may be made of memory metals or smart memory alloys, such as, for example, NiTi. In particular, these smart memory alloys are particularly suitable for use in making the retention rings used in some embodiments of the invention.
[0036] It should be clear to one of ordinary skill in the art that the drawings provided in the current application are only meant to be schematic, and the size and shape of the slots, posts and other components of the screw back-out prevention device should be designed to ensure that the moveable plates can be positioned to engage or retain the screws for which back-out prevention is desired.
[0037] While the above description contains many specific embodiments of the invention, these should not be construed as limitations on the scope of the invention, but rather as an example of one embodiment thereof. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their equivalents. | A screw back-out prevention mechanism for a bone fixation system is provided. The mechanism, when engaged, either locks or retains the screws of the bone fixation system in place thereby preventing the screws of the bone fixation system from backing out of the bone, and in turn reducing the risk of device separation or failure in the bone fixation system. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application includes subject matter disclosed in and claims priority to a provisional application entitled “Pet Locking Device With Handle” filed Jan. 9, 2012 and assigned Ser. No. 61/584,371 describing an invention made by the present inventor.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to leashes and, more particularly, to leashes having lockable and adjustable loops at opposed ends.
[0004] 2. Description of Related Prior Art
[0005] Conventional leashes for pets include a loop at one end for grasping by a user. The other end of the leash generally includes a clasp of some type for detachable attachment to a ring extending from a collar about the neck of the pet. Sometimes a harness is mounted on the body of the pet and usually includes a ring extending therefrom for attachment to a leash. These leashes are generally of leather or webbing material. Some leashes may also be formed by a cord. For larger animals, the leash is generally formed from a chain; such chains may be of various types and sizes. Some leashes include a handle enclosing a spool for selectively extending and retracting a cord forming the leash.
[0006] While conventional leashes serve the primary purpose of restraining the freedom of a leashed animal, each requires the use of a collar, harness, or the like, mounted upon the animal and to which the leash is attached. Conventional leashes do not provide the ability to secure the leashed animal to an anchor, such as a post, railing, park bench, etc. without tying the free end of the leash about or threaded through such anchor. There is no locking mechanism to lockingly secure the leash to the animal nor to lockingly secure the leash to an anchor and prevent theft of the animal.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a leash for an animal, which leash can and does serve several secondary functions apart from tethering an animal to a handheld leash. One end of the leash includes a lockable loop adjustable in size to correspond with the neck of the animal. The other end of the leash also includes a lockable loop adjustable for the hand of a user and lockingly engageable with an anchor to tether the animal in the absence of the user. A sheath extends about each loop for the comfort of the animal and the user. The leash itself is a cable that is not severable by chewing thereon by the animal nor by use of readily available conventional tools. The combination of locks and cable provide security measures to prevent inadvertent loss or theft of a leashed animal.
[0008] It is therefore a primary object of the present invention to provide a leash for an animal having lockable and adjustable loops at each end.
[0009] Another object of the present invention is to provide a sheath enclosing one or both loops of a leash for purposes of comfort.
[0010] Still another object of the present invention is to provide a leash which includes a lockable loop at one end serving as a collar for the leashed animal.
[0011] Yet another object of the present invention is to provide a leash that may be lockingly secured to an anchor to tether the leashed animal in the absence of a user.
[0012] A further object of the present invention is to provide a leash formed from a cable to prevent severance of the leash by the leashed animal chewing on the leash.
[0013] A still further object of the present invention is to provide a leash formed from a cable to prevent severance of the cable by use of conventional tools and prevent theft of the leashed animal.
[0014] A yet further object of the present invention is to provide a lockable loop for a leash to permit anchoring the leash to a fixed object.
[0015] These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will be described with greater specificity and clarity with reference to the following drawings, in which:
[0017] FIG. 1 illustrates a cable forming a leash and having two lockable loops at respective ends;
[0018] FIG. 2 is a detailed view taken along lines 2 - 2 , as shown in FIG. 1 ;
[0019] FIG. 3 illustrates a lock for locking attachment and detachment of the end of each loop;
[0020] FIG. 4 illustrates the rear of each lock mounted on the cable of the leash; and
[0021] FIG. 5 is a detail view of the support for the sheath formed at one or both loops.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] Referring to FIG. 1 , there is illustrated a leash 10 formed from a cable 12 . Preferably, the cable is encased within a plastic covering 14 . A first lock 16 , which may be a combination lock as shown, includes a passageway extending therethrough (not shown) for slidably receiving cable 12 . A first loop 18 extends from lock 16 to terminal end 20 . The terminal end includes a fitting 22 for lockingly engaging lock 16 . A push button 24 on the lock releases fitting 22 when the button is depressed and after the correct combination is entered in the lock. A sheath 26 extends along the cable forming loop 18 .
[0023] A second lock 30 is in slidable engagement with cable 12 . It may be noted that lock 30 is identical with lock 16 and the above description also applies to lock 30 . A second loop 32 extends from lock 30 to terminal end 34 . A fitting 36 extends from the terminal end into locking engagement with lock 30 . Push button 38 on the lock releases the fitting when the push button is depressed and after the correct combination is entered in the lock. A sheath 40 extends along the cable forming loop 32 .
[0024] As particularly shown in FIGS. 1 , 2 and 5 , the size of each of loops 18 , 32 may be readily adjusted to fit the neck of the animal to be leashed and the hand of the user using the leash, respectively. A ferrule 50 includes a central passageway 52 for snugly but slidably receiving cable 12 . The ferrule includes an increased diameter collar 54 . As particularly shown in FIGS. 2 and 5 , cable 12 extends through ferrule 50 and sheath 26 . The sheath is slid onto cylindrical body 56 of ferrule 50 to butt up against collar 54 . A similar arrangement of cable, ferrule and sheath is present at terminal end 20 of loop 18 . By cutting off a length of sheath 26 , the distance between the ferrules at opposite ends of a sheath will be reduced resulting in a reduced size of loop 18 . Thereby, the loop can be adjusted to fit the neck of any animal to be leashed. Loop 32 includes the same arrangement of cable, ferrule and sheath.
[0025] By modifying the length of sheath 40 , the size of loop 32 may be adjusted to fit the requirements of the user holding the leash. It is to be noted that the passageway within each of the first and second locks for housing the cable permits some sliding movement of the cable but there is preferably a degree of friction present to prevent inadvertent and other than forced sliding movement of the cable relative to one or the other of the locks that might increase the size of the respective loop.
[0026] Referring particularly to FIGS. 3 and 4 , the locking and unlocking of each of loops 18 and 32 will be described. While the reference numerals relate to lock 16 , it is to be understood that lock 30 is identical with lock 16 . Fitting 22 at terminal end 20 includes a ring 28 . This ring mates with a prong internally disposed within lock 16 that engages the ring upon insertion of fitting 22 into the lock through opening 60 . Upon depressing push button 24 , the prong disengages from ring 28 and terminal end 20 may be withdrawn from within the lock. Thereby, the leashed animal may be disengaged from the leash. Similarly, depressing push button 38 of lock 30 , terminal end 34 will be released from lock 30 . It is to be noted that each of locks 16 and 30 is a combination lock. Only upon correct alignment of tumblers 62 , 64 , of combination locks 16 , 30 , respectively, can the push button be depressed to release the respective fitting.
[0027] Aside from leash 10 serving as a leash for an animal being walked, it has another important function. Loop 32 , see FIG. 1 , serves primarily as a hand hold for the leash. However, it is capable of serving an additional very important function. When a user walks an animal, such user may, from time to time, wish to enter a store, restaurant, office building, or other facility that does not permit entry of animals. Heretofore, the best such user can do is to tie the leash to some anchor outside of the establishment. While this may restrain the animal, it is very easy for a thief to untie the leash and walk off with or kidnap the animal. When the animal is of show quality, rare or otherwise very emotionally valuable, the loss may be significant coupled with the emotional loss that would be experienced.
[0028] Loop 32 can and does serve as a locking mechanism for securing the leash, and the animal, to a post, railing, park bench, or other fixed object. This is done by dialing in the correct combination and opening loop 32 upon depressing button 38 to release terminal end 34 . The end of the loop may then be passed around the fixed object to which the leash is to be anchored. Thereafter, terminal end 34 is reinserted through opening 60 into locking engagement with lock 30 and rearranging the tumblers of the combination lock. It may be noted that both locks 16 and 30 are combination locks requiring that tumblers 62 , 64 , respectively, be set to a predetermined code in order to prevent withdrawal of respective terminal ends 20 , 34 by depressing push buttons 24 , 38 , respectively. Thereby, not only is it impossible to remove loop 18 from about the neck of the animal and thereby disengage the animal from the leash, but it is also impossible to disengage the leash from an anchor to prevent theft of the animal. Upon return of the user, tumblers 64 of lock 30 are set to the appropriate code to permit button 38 to be depressed. Upon such depression, terminal end 34 may be withdrawn from lock 30 and the loop withdrawn from about the anchor. After such withdrawal, the terminal end may be reinserted within lock 30 to form loop 32 .
[0029] It is to be understood that cable 12 may be sized to accommodate the weight and strength of the animal with which the leash is to be used. Moreover, sheath 26 extending about loop 18 may be of any thickness or cross-sectional physical size as a function of comfort for the animal. For example, an animal having a very heavy coat about its neck may be quite comfortable with a sheath of minimal size and thickness while an animal having essentially very short hair about its neck may be more comfortable with a padded and/or large diameter sheath to prevent chaffing or other discomfort. Similarly, sheath 40 extending about loop 32 may be sized and with a material selected to be most comfortable for a user using the loop as a handle of the leash. It may be noted that except for some longitudinal compression of the sheath for either loop 18 or loop 32 , the length of the respective sheath essentially defines the size of the respective loop. | A leash includes two selectively lockable loops at opposed ends. One loop is adjustable in size to fit about an animal's neck and includes a sheath for purposes of comfort and for defining the size of the first loop. A second loop is adjustable in size for the hand of a user or for attaching the leash to an anchor point. A sheath extends along the second loop for comfort and for defining the size of the second loop. | 8 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pharmaceutical composition which comprises minocycline or a physiologically acceptable salt thereof as an active ingredient, and which is useful in the treatment or prevention of a periodontal disease such as periodontitis.
BACKGROUND ART
Periodontitis (proximate periodontitis) is a chronic non-specific inflammation occurring not only in gingiva but also in other periodontia, which in most cases develops from periodontitis simplex. In this disease, periodontal pocket, tooth loosening, alveolar bone absorption, and drainage from the pocket are observed, and most of them progress indolently. It is known that certain gram negative bacilli within the periodontal sulcus are involved in periodontitis. For example, Bacteriodes gingivalis is involved in adult periodontitis, Actinobacillus actinomycetemcomitans is involved in juvenile periodontitis, and Bacteriodes intermedius is involved in acute necrotizing ulcerative periodontitis (The Journal of the Japanese Society of Periodontology, Vol. 29 No. 2 pp463-471).
It is known that minocycline is effective in the treatment of periodontal diseases. Minocycline is one type of tetracycline antibiotics which exhibits strong antibiotic action against the aforementioned periodontal pathogenic bacteria, and exhibits superior clinical efficacy against periodontitis (The Journal of the Japanese Society of Periodontology, Vol. 29 No. 2 pp472-483). For example, there is proposed a method of directly applying an ointment comprising minocycline hydrochloride (3.0%), hydroxymethylcellulose and glycerine to the periodontal pocket. Further, “Periocline dental ointment” (sold by Sunstar Inc.) is being used clinically as a periodontitis therapeutic agent.
However, since minocycline is an unstable substance, techniques for providing a stable composition comprising minocycline as an active ingredient, have been examined. For example, in Japanese Patent Publication No. 1-12728, there is disclosed a non-aqueous composition for topical administration characterized in that minocycline or a physiologically acceptable salt thereof is formulated in a base of polyhydric alcohol which comprises a magnesium compound. Further, in Japanese Patent Publication No. 2-34325, there is disclosed a composition for treatment of periodontal diseases wherein minocycline or a physiologically acceptable salt thereof is formulated with a magnesium compound, an aqueous polymeric substance, a polyhydric alcohol, an ethyl methacrylate/ethyl methacrylate-trimethyl ammonium chloride copolymer, and a solubilizer. Furthermore, Japanese Patent Application Laid-Open No. 11-286448 discloses a pharmaceutical composition for topical administration comprising minocycline or a physiologically acceptable salt thereof and an aluminium compound in a polyhydric alcohol base.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a stable pharmaceutical composition for topical administration comprising minocycline as an active ingredient. Another object of the present invention is to provide a substance for stabilizing minocycline formulated in a pharmaceutical composition for topical administration.
As a result of focused and deliberate efforts to achieve the above objects, the present inventors have found that, it was possible to achieve stabilization of minocycline in the oleaginous base, even without the use of stabilizers such as magnesium compounds or aluminium compounds, but with the use of an oleaginous base such as a gelated hydrocarbon in place of the conventionally used polyhydric alcohol. The present invention was completed based on these findings.
Thus, according to the present invention, there is provided a pharmaceutical composition for topical administration comprising minocycline or a physiologically acceptable salt thereof in an oleaginous base.
Preferably, the oleaginous base is a gelated hydrocarbon. More preferably, the gelated hydrocarbon is plastibase.
The pharmaceutical composition according to the present invention preferably further comprises one or more adhesive agent selected from the group consisting of cellulose, cellulose derivatives, water-soluble high molecular compounds and water-soluble starch.
The pharmaceutical composition according to the present invention preferably further comprises a disintegrant.
According to a preferred embodiment of the present invention, there is provided a pharmaceutical composition comprising:
(a) 0.01-15% by weight of minocycline or a physiologically acceptable salt thereof;
(b) 20-97% by weight of an oleaginous base;
(c) 1-60% by weight of an adhesive agent; and
(d) 1-20% by weight of a disintegrant
According to a more preferred embodiment of the present invention, there is provided a pharmaceutical composition comprising:
(a) 0.01-15% by weight of minocycline hydrochloride;
(b) 20-97% by weight of a gelated hydrocarbon;
(c) 1-60% by weight of hydroxypropylmethylcellulose, alpha-converted starch, carboxyvinyl polymer or methylcellulose; and,
(d) 1-20% by weight of a sucrose fatty acid ester.
The pharmaceutical composition of the present invention is preferably used in dental treatment and/or prevention, more preferably in treatment and/or prevention of periodontal diseases.
According to another aspect of the present invention, there is provided an oleaginous base which is used as a stabilizer of minocycline or a physiologically acceptable salt thereof.
DETAILED DESCRIPTION OF THE INVENTION
The pharmaceutical composition of the present invention is characterized in that it comprises minocycline or a physiologically acceptable salt thereof in an oleaginous base. The pharmaceutical composition of the present invention can be generally prepared as a pharmaceutical composition for topical administration to the oral cavity or periodontia, and preferably as a pharmaceutical composition for dental use. The pharmaceutical composition according to the present invention is preferably provided such that it is suitable for topical administration to the oral cavity or periodontia, for example as a composition in a viscous liquid or paste form. The pharmaceutical composition according to the present invention is useful in the treatment and/or prevention of oral cavity disease or disease in the dental area, for example, periodontal diseases such as periodontitis, periodontal disease, alveolar pyorrhea and the like. Moreover, the use of the pharmaceutical composition according to the present invention is not limited to the above embodiments and is able to be used as an external pharmaceutical composition on the skin or mucosa.
The type of a physiologically acceptable salt of minocycline is not particularly limited. For example, mineral acid salts such as chloride, sulfate or acetate or organic acid salts such as methanesulfonate can be used. Minocycline or a physiologically acceptable salt thereof may be a hydrate or solvate. A solvent which forms the solvate is not particularly limited so long as it is physiologically acceptable, and for example, solvates of ethanol and the like may be used. It is preferred that hydrochloride is used as a salt of minocycline. The content of minocycline or a physiologically acceptable salt thereof contained in the pharmaceutical composition of the present invention is generally about 0.01-15% by weight, preferably about 0.1-5% by weight (as the converted amount to free minocycline) relative to the weight of the composition.
The type of oleaginous base used in the pharmaceutical composition of the present invention is not particularly limited if it is one that is generally used in the pharmaceutical field. For example, gelated hydrocarbon, Vaseline, squalane, isostearic acid, yellow beeswax, liquid paraffin, mid-chain fatty acid triglyceride, cottonseed oil and the like can be used alone or in combination of two or more of them. Preferably, a gelated hydrocarbon may be used. Plastibase (Bristol Myers Squibb), Poloid (Maruishi Pharmaceutical) or the like can be used as the gelated hydrocarbon.
The content of the oleaginous base contained in the pharmaceutical composition of the present invention is generally 20-97% by weight, preferably 60-97% by weight, and more preferably 70-90% by weight relative to the weight of the composition.
In the pharmaceutical composition of the present invention, one or more substances selected from the group consisting of cellulose, cellulose derivatives, and water-soluble high molecular compounds may be formulated as an adhesive agent. As cellulose, crystalline cellulose can be used. Examples of cellulose derivatives that can be used include sodium carboxymethylcellulose, cellulose acetate phtalate, hydroxyethylcellulose, hydroxypropylmethylcellulose and the like. Among these, hydroxypropylmethylcellulose is preferred. Examples of water-soluble high molecular compounds include polyethylene glycol (Macrogol, etc.), polyvinyl alcohol, polyvinyl pyrolidon, Carragheenan, locust bean gum, arabia gum, xanthan gum, tragant gum, starch, etc.
The content of adhesive agent contained in the pharmaceutical composition of the present invention is generally about 1-60% by weight, preferably about 1-40% by weight, and more preferably about 5-20% by weight relative to the weight of the composition.
Further, in the pharmaceutical composition of the present invention, a disintegrant may be formulated. The disintegrant that can be used are not particularly limited so long as it is one generally used in the pharmaceutical field. Examples of the disintegrant include sucrose fatty acid ester, glycerine fatty acid ester, sodium carboxymethylcellulose, lactose, sodium bicarbonate and the like. Sucrose fatty acid ester can preferably be used. Examples of a sucrose fatty acid ester that can be used include sucrose stearate, sucrose palmitate, sucrose myristate, sucrose oleate, sucrose laureate, sucrose behenate, sucrose erucate, sucrose esters of mixed acid (oleic acid, palmitic and stearic acid) and the like.
The content of the disintegrant contained in the pharmaceutical composition of the present invention is generally about 1-20% by weight, preferably about 1-10% by weight relative to the weight of the composition.
Further, magnesium compounds (for example, the compounds described in Japanese Patent Publication No. 1-12728 and Japanese Patent Publication No. 2-34325) and/or aluminium compounds (for example, the compounds described in Japanese Patent Application Laid-Open No. 11-286448) may be formulated in the pharmaceutical composition of the present invention.
The pharmaceutical composition of the present invention can be prepared according to conventional methods, and the method for preparation is not particularly limited. For example, the pharmaceutical composition of the present invention can easily be prepared by adding minocycline or a physiologically acceptable salt thereof, an oleaginous base such as gelated hydrocarbon, a disintegrant and an adhesive agent to a vessel in given amounts, and blending them as described in the Examples below.
Further, when manufacturing the pharmaceutical composition of the present invention, additives for drug formulation available for those skilled in the art may be used appropriately. For example, a buffering agent, pH adjuster, surfactant, plasticizer, binder, dispersant, preservative and/or colorant, etc., may be formulated in the pharmaceutical composition of the present invention. The content of these additives for drug manufacture can be appropriately selected by those skilled in the art such that it is suitable for pharmaceutical compositions for oral cavity use, dental use, or external use for applying to the skin or mucosa. The pharmaceutical composition of the present invention can be prepared at a suitable elevated temperature where necessary, but in order to increase the stability of minocycline, it is preferred to prepare the pharmaceutical composition in a non-aqueous system.
The pharmaceutical composition of the present invention prepared as described above, can be administered to a patient by directly applying it to the affected area (for example, to the periodontal disease area), and is preferably administered topically to the periodontal pocket. The amount to be applied can be appropriately selected depending on the size of the affected area, extent of the disease, etc. For example, about 10-100 mg of the pharmaceutical composition of the present invention can be administered per tooth. Further, duration and number of administrations can be selected as appropriate.
The content of Japanese Patent Application No. 2000-150937, on which the present application claims a priority, is incorporated herein by reference.
The present invention will be further explained by examples below. However, these examples are not intended to limit the scope of the present invention.
EXAMPLES
Example 1
2 g (titer) of minocycline hydrochloride, 73 g of gelated hydrocarbon (Plastibase; Bristol Myers Squibb), 20 g of hydroxypropylmethylcellulose and 5 g of sodium carboxymethylcellulose were placed in a kneader and kneaded for 1 hour to produce 100 g of the pharmaceutical composition of the present invention.
Example 2
2 g (titer) of minocycline hydrochloride, 68 g of gelated hydrocarbon (Plastibase; Bristol Myers Squibb), 10 g of sucrose fatty acid ester, and 20 g of hydroxypropylmethylcellulose were placed in a kneader and kneaded for 1 hour to produce 100 g of the pharmaceutical composition of the present invention.
Example 3
2 g of minocycline hydrochloride, 79 g of gelated hydrocarbon (Plastibase; Bristol Myers Squibb) and 5 g of sucrose fatty acid ester, and 14 g of hydroxypropylmethylcellulose were placed in a kneader and kneaded for 1 hour to produce the pharmaceutical composition of the present invention.
Test Example 1
The pharmaceutical compositions of the present invention prepared in Examples 1 to 3, were stored for 6 months under the condition of 30° C. and 70% relative humidity. The titer of post-storage minocycline was measured in accordance with the cylinder plate method described in Japanese Antibiotic Standard Commentary (1993). The sample liquid was prepared as follows. A mass corresponding to approximately 10 mg (titer) was weighed precisely, and 10 ml of dimethyl formamide was added thereto to dissolve it. Then, 0.1M phosphate buffer (pH4.5) was added to bring the solution to exactly 100 ml, thereby preparing a solution having a concentration of about 0.1 mg (titer)/ml. An appropriate amount of this liquid was weighed out precisely and a sample solution of a prescribed concentration was prepared by precise dilution with 0.1M phosphate buffer (pH4.5).
As a result of this measurement, no significant reduction in titer of minocycline hidrochloride could be recognized in respect of any of the pharmaceutical compositions of Examples 1 to 3
Example 4
Macrogol 1500 (30 g) and Macrogol 400 (20 g) were placed in a beaker and made uniform by heating/agitation with a hot stirrer. 44 g of this mixture, and 2 g (titer) of minocycline hydrochloride, 30 g of gelated hydrocarbon, 13.9 g of hydroxypropylmethylcellulose, 10 g of calcium chloride, and 0.1 g zinc sulfate were placed in a kneader and kneaded for 1 hour to produce 100 g of the pharmaceutical composition of the present invention.
Example 5
86 g of white Vaseline, 3 g of cholesterol, 3 g of stearyl alcohol, 8 g of white beeswax were placed in a beaker and made uniform by heating/agitation with a hot stirrer. 93 g of this mixture, 2 g (titer) of minocycline hydrochloride, 5 g carboxyvinyl polymer were placed in a kneader and kneaded for 1 hour to produce 100 g of the pharmaceutical composition of the present invention.
Comparative Example 1
2 g (titer) of minocycline hydrochloride, 95 g of concentrated glycerin, and 3 g of sodium carboxymethylcellulose were placed in a kneader and kneaded for 1 hour to produce 100 g of the pharmaceutical composition of the present invention.
Test Example 2
A syringe was filled with the pharmaceutical composition prepared in Examples 4 and 5, and Comparative Example 1, tightly sealed, and stored for 15 hours at 50° C. As a result of comparing each of the post-storage compositions of Examples 4 and 5, and Comparative example 1, a change in characteristics was recognized in the composition of the Comparative Example, but no change was recognized in those of Examples 4 and 5.
Industrially Applicable Field
The minocycline-containing pharmaceutical composition of the present invention is stable, and is particularly useful in the treatment and/or prevention of dental diseases such as periodontitis, periodontal disease, or alveolar pyorrhea. | An object of the present invention is to provide a stable pharmaceutical composition for topical administration comprising minocycline as an active ingredient. According to the present invention, there is provided a pharmaceutical composition for topical administration comprising minocycline or a physiologically acceptable salt thereof in an oleaginous base. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to walls in which a frame structure has an infill, over at least a part of the area of the wall, of multiple layer panels providing an air gap between inner and outer leaves, e.g. being double- or triple-glazed.
While it is normal practice to form such multiple layer panels so that the air spaces within them are completely sealed, imperfections of construction or simply the effects of time often result in leakage and even small flows can give rise to fogging of glass areas. Also, if condensed vapour is allowed to stand in contact with many of the materials used for the wall infill, including the rubbery materials that are commonly relied on to provide sealing, it can cause deterioration.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a wall structure comprising a framework defining a series of cells in which are held infill panels with sealing means between the peripheries of the panels and the framework, at least some of the panels comprising a plurality of layers with spacing means between them to form an internal space between adjacent layers, characterised in that the peripheries of said plural-layer panels internally of said peripheral sealing means are connected by conduit means to gas pumping means to supply a gas to said panel peripheries.
In a preferred form the peripheral sealing means for the spaces are continuous-loop gaskets such as those Case A, Ser. No. 003,414 filed at the same time as this application, which gaskets also form the sealing means between the peripheries of the panels and the framework. The spaces thus enclosed may be used for pressure tests of the sealing, or as manifolds for supplying the internal spaces of the panels, in this latter case at least the spacer means not being in the form of conventional peripheral seals of double-glazing units but allowing a gas flow into said internal spaces.
If it is arranged that there should be a gas throughflow from said pumping means, said panels preferably communicate in at least one group with a common inlet conduit. The panels of the group are preferably connected together by tubes passing through the gasket walls of adjacent spaces; at least some of these tubes may be provided with non-return valves to assist the distribution of the pumped gas through the spaces, if required.
The spaces may be interconnected as a plurality of vertical files connected in parallel to the pumping means, at least some of the vertical connections within each file having non-return valves. To match the gas flows in neighbouring files they may be connected by equalizing unions spaced up the wall. If panel spaces connected in vertical files are sealed by continuous loop gaskets, the spaces between the panel layers may communicate only vertically with the peripheral spaces defined by the gaskets around the panels, for example by having a peripheral spacer for the panel layers that is provided with openings only at the top and bottom. The channels that remain between the panel side edges and the gasket can be blocked so as to confine air flow to the space between the panel layers. Equalizing unions between neighbouring vertical files may then be established through the gaskets into these side channels to avoid excessive cross-flow between the files through the unions.
If the conduit means are arranged to produce a flow of air within the structure it is preferred to provide a filter through which the pumped air passes before flowing through the spaces of the curtain wall. If, however, the pumped medium is employed only for pressure-testing the sealing of the panels or if a static gas is intended to fill the internal spaces of the panels, this precaution is not required.
The invention will be described in more detail, by way of example, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic elevation of part of a curtain wall,
FIGS. 2 and 3 are cross-sectional views on the lines A--A and B--B, respectively, in FIG. 1,
FIG. 4 is a cross-sectional view, in an orientation similar to FIG. 3, showing a modification, and
FIG. 5 is another schematic elevation of part of a curtain wall.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring firstly to FIG. 1, the curtain wall comprises a frame-like construction of extruded metal sections providing a vertical mullion 2, jamb mullions 4, transoms 6 and top and bottom sills 8, 10 to define a series of rectangular cells 12. Only six cells are shown for simplicity.
As will be described in more detail below, the cells are filled by respective infill panels 14, each of which is double leaved, e.g. as double-glazing, enclosing its own individual air space. The spaces are connected together by a series of connections 16, 18 (shown only schematically in FIG. 1) to form one or more flow paths in the interior of the wall, through which air from a pump 20, connected via a filter 22 with the air spaces of the lower cells of the wall, can pass through all the air spaces of the wall to a discharge outlet 24 at the top of the wall. In the example of FIG. 1, adjacent vertical files of cells have the spaces of each file connected in series by the connections 16, and the spaces of the files are connected in parallel by the connections 18. The air pump and filter are coupled to an inlet manifold 26 formed by the supporting framework for the panels and running along the bottom of the wall and the air flow exits through a discharge outlet coupled to an outlet manifold 28 similarly formed along the top of the wall. The inlet and outlet are at diagonally opposite regions of the group of cells. Blocking inserts 30 are provided at desired locations in the conduits formed by the framework to control the airflow and prevent it bypassing the air spaces in the panels. The horizontal connections 18 serve mainly to equalize pressure between the files.
It will be appreciated that other patterns of interconnection can be provided and that it is possible to interconnect much greater umbers of cells. In large walls it is of course possible to arrange a number of separate groups of interconnected cells each with its own inlet and outlet. It is of course possible to provide any desired number of inlets and/or outlets in any individual cell or group of cells.
As shown in FIGS. 2 and 3, the panels 32 have inner and outer leaves 34 separated by spacers 36 and are held around their edges by auxiliary members 38 of the framework in an arrangement which may be similar to those described in GB Patent Nos. 1459401 and 1496482 and European Patent Application No. 0194779, the contents of which are incorporated herein by reference. As in these earlier constructions, the edges of the panels are clamped between box-section main frame members 40 and side limbs 42 of the generally T- or Y-form auxiliary members 38, which are secured to the main members by screws (not shown). Flexible sealing gaskets 44 of extruded neoprene are provided between the front and rear edges of each panel and the surfaces of the main frame members and auxiliary members between which these edges of the panel are clamped.
Referring to FIG. 2, a main frame member 40 of a transom and an opposed auxiliary frame member 38 are positioned relative to each other by locating plates 46 in opposed recesses 48, 50 respectively in the main and auxiliary members, and are secured together by screws 52 inserted through apertures in the central front recess of the auxiliary members to grip the sides of the recesses 48. The members 38, 40 clamp between them the edges of two neighbouring double-glazed panels 32. The peripheral spacer 36 extending around the edge of each panel is a U-section channel that takes the place of the seals conventional in such panels. Along the top and bottom edges of the panel only, a series of apertures 54 in the web of the spacer provide access to the space between the leaves. Engaging the front and rear leaves of each panel are front and rear sealing portions 56, 58 of the flexible sealing gasket 44. The gaskets are described in case A, Ser. No. 003,414 the same time as this application, which also describes a framework construction employing the same extruded metal sections, and they are each in the form of a continuous loop extending around the periphery of a respective panel, the front and rear sealing portions being linked by an intermediate web 60 that forms a channel around the edge of the panel. Each gasket thus encloses the air space in its associated double-glazed panel.
For their support, at the bottom edge of each panel, support plates 62 project at intervals from slots 64 in the transom or bottom sill main frame members in which they are frictionally engaged, and the outer ends of the plates rest on the central rear limbs of the associated auxiliary members. The panels bear on the support plates through the gaskets and there are also short panel supports 66 within the gaskets to keep the bottom edges of the panels spaced from the gasket web. The panel supports are hollow so as not to block air flow along the gasket under the bottom edge of the panel, and have a U-section shape with in-turned flanges on which the edges of the inner and outer leaves 34 rest.
Connecting tubes 70 lead into the interior of the gaskets at the bottom edge of the lowermost unit at the bottom sill and at the top edge of the uppermost unit at the top sill. In each case the tubes open into the interior of the box sections of the main frame sill members where they have shut-off cocks 72 to isolate the panel air spaces. The top and bottom sill box sections thus serve as outlet and inlet manifolds for the pumped air flow.
The connections between successive panels in each vertical file indicated at 16 and 18 in FIG. 1 each comprise two tubes 80 which, in a similar manner to the inlet and outlet connections 70, are mounted in the hollow box-section main frame members through openings in the front walls of the members. The front end of each tube extends through an aperture in the web of a respective one of the two gaskets 44, to which it is sealed. The rear ends of each adjacent pair of tubes inside the main frame members are joined by a short U-shaped conduit 82 including a non-return valve to ensure that air can only pass from the lower to the upper of the spaces they interconnect. In the illustrated example there are two such vertical connections between each pair of neighbouring panels in a file; for maintenance and testing purposes inspection openings 84 with removable covers 86 are provided in the main frame transom members close to them, and each tube 80 has a shut-off cock 88 to allow pressure testing of the units to be performed.
At the reveals 90 that bound the curtain wall, there are fixed parallel pairs of ribs 92 with a sealing mastic 94 between them. The projecting ribs are engaged by and edge gasket 96 mounted between the main and auxiliary frame members in a similar manner to the panel gaskets. The edge gasket has front and rear portions of the same sectional form as the panel gaskets for engagement by and sealing with the frame members. The integral web 98 between these portions also carries a thicker intermediate portion 100 that has opposite ribbed sealing faces gripped between and engaging with the fixed ribs.
In the horizontal section of FIG. 3, the assembly illustrated is the same in many respects to the vertical section shown in FIG. 2. Additionally, there can be seen the blocking inserts 30 of a silicone mastic in the channel between the gasket web and the side edge of each panel to prevent a bypass flow through this channel that would diverts some airflow from the space between the two leaves of the panel. Such blocking means are placed in all the vertical passages formed by the gasket webs, including those of the edge gaskets 96 at the jamb mullions 4, as can be seen from FIG. 1. In addition, to assist equalisation of the flow between the vertical files, a connection 104 is provided between each laterally adjacent pair of panels. This comprises a short horizontal tube 106 between the adjacent gasket webs with reduced diameter screwed ends passing through holes in the webs. Nuts 108 threaded onto the screwed ends clamp sealing washers 110 against the edges of the holes.
In the operation of the venting system described, all the cocks 88 on the valved connectors for the peripheral spaces defined by the gasket webs are opened and the pump 20 and filter 22 produce a clean airflow that is directed into the bottom manifold 26 formed by the main frame member of the bottom sill, and from there through the spaces between the leaves of the panels to the upper manifold 28 formed by the main frame member of the upper sill to the discharge outlet. In its passage up the files the air is forced to flow through the spaces between the leaves and the lateral connections 104 help to spread the flow across the width of the structure.
While filtering the airflow can remove most foreign particles, it is preferred to reduce the possibility of adhesion of any residual particles or other deposits to the inner surfaces of the panel leaves if they are of a transparent or translucent nature, and it is possible to coat these surfaces with a silicone compound of a type known for making external glass surfaces easier to clean.
FIG. 4 illustrates a modified supply connection 18, in this case located in a mullion 2. Parts identical to those already described with reference to FIGS. 2 and 3 are indicated by the same reference numbers. An air supply tube 120 extends through the front web of the mullion box section 40 and is secured in place by locking nuts 122. The outer end of the tube 120 has threaded engagement to the stem of a T-piece 124. The oppositely directed arms of the T-piece project through the webs of the adjacent gaskets 44 and have screwed ends to fix and seal them in place using nuts 108 and sealing washers 110. An opening 128 at the rear of the box section gives access to the threaded inner end of the tube 120 for connecting it to the air supply circuit.
In the example described above connections are provided to establish a circulation of air thorugh the spaces between the panels. If the gas flow is not required for the prevention or removal of condensation it is only necessary in most instances to maintain a positive pressure in a closed volume. Outlet conduits are then not provided or are kept closed and consumption is limited to leakage losses.
This arrangement would be appropriate if the interconnected spaces are to be filled with gaseous media to make use of particular properties of such media, in particular for altering the physical characteristics of the wall. As an example, argon can be supplied to the spaces in the panels to give improved sound insulation. It has been shown that argon can give a dB reduction some 5 times greater than that of air. Other gasses may be employed to make use of their different physical attributes, e.g. for reducing the transmission of ultra violet light. Pre-dried air may be held in this way, simply to prevent condensation.
In the example illustrated schematically in FIG. 5 a supply conduit 140 is connected in parallel to a series of panels 142, in each case a non-return valve 144 being provided in the branch line 146 to the particular panel to isolate the panels from each other. The spaces within the panels can all be charged to a positive pressure and leakage from one will not draw gas from the others. The set-up shown in FIG. 5 also has test valves 148 connected to each branch line downstream of the non-return valve 144 because it illustrates, in fact, a pressure test system for checking the sealing integrity of the individual panels and their gaskets. The test valves may be simple core-type inflation valves, such as Schrader (Trade Mark) valves, and they permit a pressure gauge to be connected to each panel interior in turn. The flow pattern of FIG. 5 can be achieved using connections such as that shown in FIG. 4, with the rearwardly directed tube 120 containing a Schrader valve 148 and one of T-arms containing a check valve 144. | An infill of multiple-layer panels, each with an air space between inner and outer leaves, is provided in a curtain wall frame structure. The panels have peripheral gaskets that provide channels surrounding the internal air spaces of the panels. The channels are connected in at least one group to gas pumping means. In one mode the channels communicate with the panel internal spaces and the pumped gas forms a venting flow through said spaces. In another mode the gas can be held under pressure: this can be to keep the internal spaces filled with a particular gas or for pressure testing, e.g. at the peripheries of the panels. | 4 |
RELATED APPLICATIONS
[0001] The present application is a National Phase entry of PCT Application No. PCT/GB2011/000955, filed Jun. 24, 2011, which claims priority from Great Britain Application Number 1014599.3, filed Sep. 2, 2010, the disclosures of which are hereby incorporated by reference herein in their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to a terrain visualization device that projects a pattern of light onto the terrain, allowing a user to see the topography of the terrain even in poor lighting conditions. The invention also relates to a method for traversing terrain and a method for illuminating a ski run.
BACKGROUND
[0003] There is a common problem encountered in skiing when lighting conditions are poor, whether due to low cloud or the time of day. In such conditions, sunlight may not produce shadows on the snow, either due to the sun being obscured by cloud or due to the position of the sun in the sky. It is very difficult for a skier to see the topography of the terrain without shadows on the snow because the snow-covered ground appears as a uniform white sheet, without colour color or luminance contrast.
[0004] The above problem is particularly dangerous in winter sports such as skiing, snowboarding and mono-skiing, where it can lead to accidents caused by the skier unexpectedly either leaving the ground or hitting a bump in the snow. However, the same problem is encountered when traversing snow-covered ground by any means including walking and driving a vehicle.
[0005] A similar problem is also encountered when traversing other types of terrain that are uniform in appearance and do not provide sufficient color or luminance contrast to see their topography in poor light. For example, the problem can also be encountered in water sports such as waterskiing in low light, or when hiking at night.
SUMMARY OF THE INVENTION
[0006] Embodiments are designed to overcome the above problems by allowing a user to see the topography of terrain despite poor lighting conditions. Embodiments are designed to achieve this using much less energy than would be required to fully illuminate the terrain.
[0007] According to an embodiment, there is provided a terrain visualization device comprising a wearable mounting structure adapted to be fixed to a user; and a light emitting unit attached to the mounting structure and configured to project a predetermined contrast pattern onto terrain when the mounting structure is fixed to a user.
[0008] The pattern projected by the light-emitting device is distorted by the terrain as seen by the user. Since the user is familiar with the undistorted shape of the pattern, as projected onto flat ground, the user can easily deduce the shape of the terrain from the distorted pattern and can react accordingly. There is no need for the user to actually be able to see features of the terrain, its shape is inferred by the distortion of the pattern. Hence, an embodiment operates completely differently from a conventional illumination device. A conventional illumination device would require sufficient power to illuminate the entire area of terrain ahead of the user, whereas an embodiment only projects onto a fraction of that area and relies on contrast between the projected pattern and the surrounding terrain rather than illumination of the terrain itself.
[0009] In other words, an illumination device such as a headlight must illuminate the terrain with sufficient power that a visible luminance contrast is created by differences in reflectivity of the terrain as seen by the user. On the other hand, an embodiment creates its own luminance contrast by projecting a pattern, which requires much less power.
[0010] In an embodiment, the light emitting unit includes a laser light source. Suitably, the laser light source is a class 1 laser. In an embodiment, the laser light source has a power output of 5 mW or less.
[0011] Alternatively, the light emitting unit includes a superluminescent diode light source. Suitably, the mounting structure is one of a belt, a belt clip, an arm strap and a head strap. Conveniently, the mounting structure is a belt and the light emitting unit is attached to a buckle of the belt.
[0012] In an embodiment, the mounting structure includes a light source holder and the light emitting unit is detachably attached to the light source holder.
[0013] In an embodiment, the predetermined contrast pattern comprises at least one of a line and a dot. For example, in one embodiment the predetermined contrast pattern is a two-dimensional pattern of lines and/or dots.
[0014] Using a pattern of lines and/or dots reduces the surface area of the projected pattern and hence the power consumption of the device, while providing a clearly visible contrast pattern. Using a two-dimensional pattern allows the user to see the shape of the terrain in three dimensions without difficulty.
[0015] Suitably, the predetermined contrast pattern comprises a plurality of dots.
[0016] In an embodiment, the predetermined contrast pattern comprises a straight line.
[0017] Conveniently, the predetermined contrast pattern comprises at least one of an arc, a regular polygon, a circle, a cross, a grid and a regular dot array. For example, in one embodiment the number of lines in the predetermined contrast pattern is between 1 and 4.
[0018] Using a straight line or a regular shape for the projected pattern allows distortion in the pattern to be seen more easily. Straight lines can be advantageous in embodiments because it is easier to manufacture a light source capable of projecting a straight line than one capable of projecting more complex shapes. In particular, using between 1 and 4 lines in the pattern provides a good balance between ease of manufacture and accurate visualization of the terrain.
[0019] In an embodiment, the light emitting unit comprises at least one of a lens and a holographic plate for generating the predetermined contrast pattern.
[0020] In an embodiment, the light emitting unit is adapted to project the predetermined contrast pattern continuously.
[0021] Alternatively, the light emitting unit is adapted to project the predetermined contrast pattern intermittently. Suitably, the light emitting unit is adapted to project the predetermined contrast pattern repeatedly at a preset frequency. In one embodiment, the light emitting unit is adapted to project the predetermined contrast pattern for a preset duration.
[0022] Conveniently, the light emitting unit is adapted to project the predetermined contrast pattern in response to operation of a switch.
[0023] In an embodiment, the light emitting unit is adapted to emit narrowband light. More preferably, the light emitting unit is adapted to emit light in the visible spectrum.
[0024] In one embodiment, the light emitting unit is adapted to emit light outside the visible spectrum. Suitably, the light emitting unit is adapted to emit infra-red light.
[0025] In one embodiment, there is provided a system comprising the device adapted to emit light outside the visible spectrum described above and an optical sensing apparatus, wherein the optical sensing apparatus is adapted to detect the light outside the visible spectrum emitted by the light emitting unit and reflected from the terrain and to display the light outside the visible spectrum as visible light, to allow the user to see the predetermined contrast pattern projected onto the terrain.
[0026] According to another embodiment, there is provided a belt, head strap, helmet, ski, mono-ski, snowboard, shoe or boot comprising the device described above.
[0027] According to a further embodiment, there is provided a method for traversing terrain comprising fixing a wearable mounting structure to a user, the mounting structure having a light emitting unit attached thereto; traversing the terrain; and projecting a predetermined contrast pattern onto the terrain using the light emitting unit while traversing the terrain, so that the topography of the terrain can be determined from distortion of the contrast pattern.
[0028] In an embodiment, the method further comprises skiing, mono-skiing or snowboarding across the terrain.
[0029] According to another embodiment, there is provided a method for illuminating a ski run using a terrain visualization device including a mounting structure and a light emitting unit attached to the mounting structure, the method comprising: fixing the mounting structure to a static object; and projecting a predetermined contrast pattern onto the ski run using the light emitting unit, so that the topography of the ski run can be determined from distortion of the contrast pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Embodiments of the present invention will now be described by way of further example only and with reference to the accompanying drawings, in which:
[0031] FIG. 1 shows a skier using a device according to an embodiment of the invention;
[0032] FIG. 2 is a schematic diagram of a belt-mounted visualization device according to an embodiment of the invention;
[0033] FIG. 3 is a schematic diagram of a head-mounted visualization device according to an embodiment of the invention;
[0034] FIG. 4 is a schematic diagram of a visualization device according to an embodiment of the invention designed to be clipped to a belt or strap;
[0035] FIGS. 5(A) to 5(F) illustrate patterns of light emitted by devices according to embodiments of the invention; and
[0036] FIG. 6 illustrates the distortion of a cross-shaped light pattern according to an embodiment of the invention by uneven terrain.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] As shown in FIGS. 1 and 2 , a device 100 according to an embodiment includes a light emitting unit 102 attached to a mounting structure 104 . The mounting structure 104 includes a belt and a light source holder 106 . The device 100 projects a predetermined contrast pattern of light 108 onto terrain 110 in front of a user.
[0038] In this embodiment, the light emitting unit 102 comprises a laser diode and complies with the ANSI Z136 and IEC 60825 standards. However, any light source sufficiently bright and directional to project a contrast pattern onto a terrain surface from a distance of a few meters can be used. In particular, a coherent light source is not required and a non-coherent source such as a superluminescent diode (SLED) can be used instead.
[0039] The power of the light source must be sufficient in embodiments for the user to see the contrast pattern projected by the light source onto the ground. However, the light source must not be so powerful that it could cause eye injury to the user or other people nearby. Class I lasers, which are eye safe, and SLEDs are particularly suitable as the light source for this reason. A Class 11/2 laser with a power of up to 1 mW is also relatively eye safe and is suitable for use as the light source. A Class IIIa/3R laser with a power of up to 5 mW can be used as the light source but must be operated with due caution.
[0040] The wavelength of the light source is not particularly limited. Of course, any color of visible light can be used but it is also possible to use wavelengths outside the visible spectrum if the device 100 is designed to be used in conjunction with an optical sensing apparatus detecting the wavelength used. For example, it is possible to use an infra-red light source so that the projected pattern can be seen using thermal night vision goggles. A Nd:YAG infra-red laser is particularly suited to be the light source in this embodiment. Using a light source emitting light outside the visible spectrum has the advantage that the projected pattern is only visible to a user with appropriate equipment, such as thermal goggles. This means that the contrast pattern will not distract others nearby, for example other skiers on a ski slope. This embodiment is particularly useful at night, when infra-red night vision goggles would be used in any case.
[0041] The light emitting unit 102 is configured to project a contrast pattern 108 onto the terrain surface. The pattern 108 can be a single line, it is only necessary for the user to be able to detect the topography of the terrain onto which the pattern 108 is projected based on the distortion of the pattern 108 . The device 100 is effective because the user knows the shape of the projected pattern 108 on a flat surface and can thus infer the topography of the terrain by comparing the distorted pattern 108 with the known flat surface pattern 108 . This process quickly becomes intuitive and then does not require conscious thought on the part of the user.
[0042] In this embodiment, the laser diode projects a single straight line pattern 108 . This can be achieved by using a laser diode that has a line-shaped (i.e. relatively long compared to its width) light-emitting area, or by passing light from the diode through a lens or slit in the desired shape. Alternatively a holographic plate can be used to generate the light pattern projection. Suitable methods for generating a line pattern are described in U.S. Pat. Nos. 4,321,551 and 6,069,748, which are hereby incorporated herein by reference in their entireties.
[0043] The light emitting unit 102 is attached to a belt in this embodiment, so that the device 100 can be attached to the waist of a user. The belt has a light source holder 106 fixed to it and the light emitting unit 102 is detachably clipped into the light source holder 106 . However, the light emitting unit 102 can also be integral to the mounting structure 104 . It is preferred that the light emitting unit 102 be detachable in one embodiment so that it can be replaced in the event of failure.
[0044] The light source holder 106 forms part of the buckle on the front of the belt in this embodiment. However, the light source holder 106 can also be fixed to the material of the belt itself, either at the front or to one side. The light source holder 106 holds the light emitting unit 102 in such a way that its position and angle are fixed in use. The light source holder 106 holds the light emitting unit 102 at a position and angle such that when the belt is worn by a user, the light emitting unit 102 projects the pattern 108 onto the terrain in front of the user. In this embodiment, the light emitting unit 102 is held at an angle such that the pattern 108 is projected onto the terrain approximately 2 to 4 m in front of the user when the belt is attached to the user's waist. The distance in front of the user should be sufficiently short that the pattern 108 is clearly visible but sufficiently far that the user has time to react to changes in the terrain. The optimal distance varies depending upon the expected lighting conditions and speed of the user among other factors, but a distance of between 2 m and 6 m has been found to be suitable for most applications.
[0045] In the above embodiment, the device 100 is mounted to the waist of a user. This arrangement is advantageous because the user's waist does not tend to move independently as much as other body parts, which makes the pattern 108 projected by the device 100 more stable on the terrain and hence easier to read. However, the device 100 can also be configured to be attached to any other body part of the user.
[0046] A head-mounted device 100 according to another embodiment is shown in FIG. 3 . The device 100 includes a head strap 112 , which can be attached directly to the head of the user or can be attached to a helmet. A light emitting unit 102 as described above is fixed to a front portion of the head strap 112 . The light emitting unit 102 is configured so that when the head strap 112 is worn by the user, the pattern 108 projected by the light emitting unit 102 is projected onto the ground with the user's head at a comfortable angle. The head-mounted device 100 has the advantage that the user can select a piece of terrain on which to project the pattern 108 simply by a head movement. This is particularly useful when the user needs to change direction suddenly.
[0047] In the above embodiments, the mounting structure 104 includes the belt or head strap 112 . However, it is also possible to provide a mounting structure 104 consisting only of a light source holder 106 having a belt clip 114 as well as a portion configured to engage with and hold the light emitting unit 102 , as shown in FIG. 4 . In the embodiment shown in FIG. 4 , the light emitting unit 102 is fitted into a hole in the light source holder 106 . The mounting structure 104 can then be clipped onto an existing belt or other item of clothing so as to fix the light emitting unit 102 to the user's waist or other body part. The precise form of the mounting structure 104 is not important to the invention provided that it is capable of securely attaching the light emitting unit 102 to the user's body.
[0048] This embodiment has the advantage that it can be interchangeably attached to a belt as shown in FIG. 2 , to a head strap as shown in FIG. 3 and to a range of other wearable accessories.
[0049] The terrain visualization device 100 can also be clipped or otherwise attached to the front of a vehicle, such as a mountain bike or snowmobile, so as to project the pattern 108 onto the ground and provide terrain visualization when driving the vehicle.
[0050] In an alternative embodiment, the device 100 can be attached to a static object such as a ski lift pylon or a tree. The device 100 is mounted to the static object in such a way that the light source projects the pattern 108 onto a nearby area of terrain, enabling any passer by to see the topography of that piece of terrain. In this embodiment, the mounting structure 104 is adapted to fix the light emitting unit 102 securely to the desired static object so as to point downwards, towards the area of terrain to be illuminated. For example, the mounting structure 104 in one embodiment is an adjustable strap and buckle adapted to be wrapped around the trunk of a tree.
[0051] The light source holder 106 is fixed to the buckle at a downwards-facing angle and friction between the strap and the tree trunk holds the device 100 in position. This embodiment is particularly useful in a ski resort, where specific areas of a ski run may be known to be dangerous. A device 100 according to the invention can be mounted to a static object at the side of the ski run so as to project a pattern 108 onto a dangerous area, for example a steep-sided bump. In this way, any skier coming down the run will be able to see the bump and react appropriately, even in poor light.
[0052] The light emitting unit 102 can be configured to project a wide range of different patterns 108 . A single line has the advantage of simplicity and ease of manufacture. However, a two-dimensional pattern 108 provides greater information on the shape of the terrain in three dimensions. A pattern 108 made up of regular shapes is used in one embodiment because it makes the distortion caused by the underlying terrain more apparent and easier for the user to interpret. However, irregular shapes can also be used. Examples of suitable projection contrast patterns 108 are illustrated in FIG. 5 . These shapes are a straight line, a cross, a circle, an arc, a grid and a regular array of dots respectively.
[0053] In one modification, the pattern 108 is an array of parallel lines. In an embodiment, this pattern includes between 2 and 4 parallel lines. In an embodiment, the contrast pattern 108 is made up of lines and/or dots rather than large blocks of light because this greatly reduces the power consumption of the light emitting unit 102 . As discussed above, a major advantage of embodiments is that the shape of the terrain is inferred indirectly through distortion of the projected contrast pattern 108 . As a result, there is no need to illuminate a large area of terrain so that the features of the terrain are directly visible. The light emitting unit 102 projects the pattern 108 continuously when the device 100 is switched on in this embodiment. However, the light emitting unit 102 can alternatively be configured to project the pattern 108 intermittently. The light emitting unit 102 can project the pattern 108 at a preset frequency for a present duration, for example at 2 Hz for 100 ms at a time.
[0054] The light emitting unit 102 can also be configured to project the pattern 108 only at certain times of day, for example between sunset and dawn. In this case, the device 100 is further provided with a timer and/or light sensor and circuitry for turning the light source on and off in response to the output of the timer and/or light sensor. Alternatively, in other embodiments, the light emitting unit 102 can only be activated when a low contrast condition is detected. In this case, the device 100 is further provided with a contrast sensor and circuitry for turning the light source on and off in response to the output of the contrast sensor.
[0055] A switch can provided on the device 100 and the light emitting unit 102 can be configured to project the pattern 108 only when the switch is activated by the user. In this way, the power consumption of the device 100 is further decreased because the time for which the light emitting unit 102 is active is reduced.
[0056] The light emitting unit 102 can be powered by an electrical power source such as a battery, as is conventional.
[0057] The foregoing description has been given by way of example only and it will be appreciated by a person skilled in the art that modifications can be made without departing from the scope of the present invention. | A terrain visualization device is disclosed, the device comprising a wearable mounting structure adapted to be fixed to a user. The device also includes a light emitting unit attached to the mounting structure and configured to project a predetermined contrast pattern onto terrain when the mounting structure is fixed to a user. Also disclosed is a method for traversing terrain comprising fixing a wearable mounting structure to a user, the mounting structure having a light emitting unit attached thereto, traversing the terrain, and projecting a predetermined contrast pattern onto the terrain using the light emitting unit, so that the topography of the terrain can be determined from distortion of the contrast pattern. A method for illuminating a ski run is also disclosed. | 6 |
BACKGROUND OF THE INVENTION
Recent years have witnessed a significant rise in the per capita consumption of poultry. This increase has been accompanied by a decrease in the consumption of beef. Much of this increase in poultry consumption (generally chicken) can be attributed to a heightened awareness on the part of the consumer of the need to eat foods which are lower in fats, particularly animal fat. This has quite naturally lead to an increase in the consumption of poultry, which is lower in harmful fats than beef. Much of the fat contained in poultry is situated subcutaneously, i.e., at or beneath the skin. By removing the skin, one further reduces the quantity of fat and the caloric content of an already healthy food substance.
Originally, those wishing to prepare meals utilizing skinless chicken parts were dependent upon manual labor to remove the chicken skin. However, in time, machines were developed to automate this process so that today one can purchase machine deskinned chicken parts at the supermarket. Such machines must be economical for use in a mass production setting, and preferably should be flexible enough to handle a full range of chicken or other poultry parts. In addition, while being rapid and effective in separating skin from meat, such machines must not overly damage the meat itself, for this reduces the marketability of the product.
Finally, and of great importance, such a machine must be designed so that it is easy to clean. Poultry is a well known source of salmonella and other bacterial contaminants. Salmonella is a common contaminant carried in the gut of most poultry. During the slaughtering and dismemberment of chickens and other foul, the viscera unavoidably make contact with the surface of the bird, thereby contaminating the skin and other exposed parts. By removing the chicken skin, one at least partially removes some of the salmonella. However, this presents a special problem with respect to maintaining a deskinning apparatus in proper hygienic condition. Because salmonella is largely a phenomena of surface contamination (i.e., outside of the digestive tract, it is most commonly found on the skin), any apparatus that removes the skin must be designed so that it can be kept clean. Structural features of a deskinning machine which are of little import with respect to the purely mechanical action of deskinning can take on great importance when considered in view of the need to maintain a clean work environment.
U.S. Pat. No. 4,723,339 to Van de Nieuwelaar et al. teaches a deskinning apparatus which uses transverse pinch roles 10a and 10b with helical teeth. These helical rolls counterrotate and are used to grip and tear skin from the underlying tissue. However, this device is not suitable for use on individual parts, and requires separate structure to move the chicken across the rolls. The patent to Hill, U.S. Pat. No. 4,459,721 (hereby incorporated by reference), teaches a device to deskin individual chicken parts. However, it relies on blind bearing blocks separated by a narrow gap and a shear section for separating the skin from the chicken, both of which are very difficult to clean. This may present a heightened risk of contamination from salmonella and other microbes as noted above.
This invention is directed towards the further refinement of a versatile, economical chicken and other poultry deskinning apparatus that is easy to clean and effective to use.
SUMMARY OF THE INVENTION
This invention provides a chicken (or other poultry) deskinning apparatus in which skin is separated from the underlying meat by the action of a pair of motor driven, counter-rotating, helically geared rollers. The rollers terminate at their outfeed ends at a pair of open ended bearing blocks known as "back blocks". Any chicken skin that has adhered to the rollers will be extruded through these back blocks as the rollers counter-rotate, and so does not accumulate on the machine as it would were the rollers to terminate at their outfeed ends in a blind recess. A second pair of rollers may be disposed beneath the first pair of rollers to accommodate higher production speeds. The device includes various additional features for transporting chicken parts to and from the deskinning station. Further features, advantages, and embodiment of the invention are apparent from consideration of the following detailed description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the principle elements of a deskinning apparatus;
FIG. 2 is a perspective view of the rollers and back blocks constructed according to the principles of the invention;
FIG. 2a is a simplified perspective view of one possible mounting arrangement for the rollers;
FIG. 3 shows these elements in conjunction with infeed and outfeed chutes, lift off wedge, cogged wheel and knock off wedge;
FIG. 4 shows an alternative embodiment to FIG. 3, in which the knock-off wheel lacks cogs;
FIG. 5 is a perspective view of an alternative embodiment directed towards a deskinning machine for use with a whole breast and attached wings;
FIG. 6 shows a leg deskinner utilizing an infeed shoot, an outfeed shoot, a knock off wedge, and a diverting wedge;
FIG. 7 shows an alternative embodiment of a deskinner for use with boneless product;
FIG. 8 provides a perspective view of a deskinner for use with line delivered products of varying sizes; and
FIG. 9 is a perspective view of the rollers of a further embodiment, in which dual sets of rollers are employed.
DETAILED DESCRIPTION
FIG. 1 shows the general arrangement of elements of a deskinning machine. At the heart of the machine is the deskinning station (FIG. 2). The deskinning station is made up of a pair of counter-rotating helical rollers 3 and 4 driven by an electric motor 14. These rollers are defined by an infeed end 7 and an outfeed end 8, and are typically 36 inches in length, depending on the poultry parts with which they are used. A motor drives one of these rollers at its infeed end; this roller in turn drives the second roller through the gearing provided by their contacting helical teeth. Both the rate at which the rollers rotate and the rate at which chicken parts are fed to the roller may be adjusted by the operator. At least one of the rollers (generally the roller that is not directly driven by the motor) is pivotable about a point at its infeed end. This allows the machine operator to establish a wedge-like gap between the two rollers from the infeed end to the outfeed end through which chicken skin may fall. This feature also allows one to compensate for the change in tooth geometry which inevitably results from wear, by moving one roller nearer the other.
As the chicken moves along the rollers, the counter-rotation and the helical cut of the teeth act to propel the chicken part forward as the skin is worked free from the underlying meat. The chicken skin will then often fall through the gap between the rollers to an underlying waste bin. However, some of the separated skin may adhere to the rollers. This skin will be propelled forward along the rollers towards the outfeed end.
The rollers are supported in bearing blocks 31 and 32 known as open back blocks. These bearing blocks 31 and 32 or open back blocks, as their name suggests, is provided with cylindrical through hole 33 and 34 respectively, extending from end to end. These through holes serve both to accommodate the insertion of a roller and to enable any chicken skin which has not fallen through the longitudinal gap between the rollers to be extruded out the rear or outfeed end of the bearing blocks. At least one of these back blocks may be laterally displaceable with respect to the other. The displaceable back block is associated with a roller which is pivotable about at its infeed end. By moving the back block, one can open or close a wedge like gap between the rollers. The gap is at a minimum at the outfeed end of the rollers. The chicken skin which fails to fall through this gap after it has been pried away from the chicken part by action of the rollers instead adheres to the rollers and is propelled forward by their rotation. When these portions of skin reach the rear openings of the back blocks, they are extruded out as shown in FIG. 2. This arrangement provides for a more hygienic device than is generally obtained when one uses blind back blocks to support the rollers. (The closed recesses within blind back blocks tend to accumulate chicken skin and are difficult to clean.)
At high rates of production (particularly of large parts), the skin may not be detached rapidly enough from the cutting rollers and jamming may ensue. This problem can be solved by providing a second set of rollers spaced directly beneath and running at twice the speed of the upper set to move rapidly pull off any attached skin (FIG. 9).
The precise configuration of parts employed about the rollers is generally a function of the type of poultry part being deskinned. An infeed chute 50 and an outfeed chute 55 may be provided to transport poultry parts to and from the deskinning station (see FIG. 6). In other embodiments, this may be combined with side rails 51 to transport a whole breast and attached wings (FIG. 5) as part of an overhead conveyor system. At the outfeed end may be provided a diverting, or "lift-off" wedge 40 for lifting the meat up from the rollers, and a knock-off wedge 60 for deflecting the skinned poultry part off the rollers (see FIG. 6). Where a whole leg, thigh, or drumstick is being deskinned, it may be desirable to provide a knock-off wedge 60 and rotating cogged wheel 61 that is angled with respect to the longitudinal axis of the feed direction, for knocking deskinned chicken parts off of the rollers (FIG. 3). Alternatively, such a device may use a wheel lacking cogs (figure 4). The knock-off wedge is set at an elevation above the rollers to allow the detached skin to move beneath the wedge and continue on towards the outfeed end of the rollers. FIG. 5 illustrates the use of the side rails 51 for deskinning a whole breast and attached wings. In this embodiment, the wing rails are used to guide the chicken breast along the rollers as they are being deskinned. The outlet end of the rollers is covered by a cover 59 spaced above the rollers at a distance sufficient to allow the chicken skin to pass underneath.
In the case of a leg deskinner, both a diverting wedge and a knock off wedge may be employed.
FIG. 3 illustrates the combination of certain of the aforementioned additional elements, such as inlet chute 50 and outlet chute 55. This embodiment also utilizes the so-called lift-off or diverting wedge 40 which helps lift the chicken part off and away from the rollers. The embodiment also shows the use of a knock off wedge 60 diagonally arrayed with respect to the rollers and spaced above them a distance sufficient to allow skin to pass beneath. The removal of the chicken part from the rollers may be further facilitated by the provision of a motor driven knock-off wheel 61 (see FIG. 4), which may have cogs 62 (FIG. 3). The wheel and cogs rotate, so that as the poultry parts arrive at the wheel by the propulsive action of the rollers, they are knocked off the rollers by the action of the wheel and cogs (if present). Alternatively, the knock-off wedge may be used without the wheel. The prompt removal of the poultry part as soon as it has been deskinned serves to minimize damage to the underlying meat that might occur if the part were allowed to ride the full length of the rollers.
FIG. 7 illustrates an alternative embodiment especially well suited for use with boneless products. Boneless products present a greater challenge in that they have less structural rigidity. The boneless product deskinner utilizes a pair of bearing back blocks 70 cut from below on a diagonal 71 to allow skin to fall out the bottom of the blocks. The bearing blocks are arranged so that they extend past the rollers approximately the length of the product. At their upper surface 72, the two blocks together form a V-shape to allow the product to come to rest at the end of the blocks. The spacing between the blocks is just sufficient to allow any protruding skin to be ground through the rollers while protecting the boneless meat. A rotating pusher P is utilized to displace the product off of the blocks when or if such is required.
In the embodiment shown in FIG. 8, the deskinning station is mounted on pivots 80 and spring or counterbalanced. The rollers are mounted on pivots at their infeed end so that they can be set at an acclivity (upward incline) of approximately 10 degrees. Chicken product is fed to the rollers by cones or along a horizontal conveyor which generally holds poultry parts suspended from a common height with respect to their top-most surfaces. Because large parts will protrude downwards from this common height a greater distance, they will make contact with the helical teeth before the smaller parts make contact. Hence, large poultry parts, which take longer to deskin, are exposed to a greater portion of the deskinning rollers (and hence a longer period of contact) than smaller products, which require less time on the rollers. As in the other embodiments, the outfeed bearing blocks have a through-hole for the free passage of chicken skin. | In a chicken deskinning device a pair of rollers is provided whereby one may be pivoted with respect to the other for defining a gap therebetween. The rollers terminate in a pair of blocks, each of which has an open end to allow the passage of chicken skin past the rear of the roller bearing blocks. A second set of rollers may be employed beneath the first set. | 0 |
REFERENCE TO RELATED APPLICATION
This application is a non-provisional of U.S. Provisional Application No. 61/108,694, filed Oct. 27, 2008 with title “Patient Lifter with Variable Height, Variable Load Bearing, and Variable Horizontal Position Drive Wheels,” pending.
FIELD
The present invention relates to land vehicles. More particularly, it relates to movable devices with patient transfer features.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a patient transfer device according to one embodiment of this disclosure.
FIG. 2 is a perspective view of an indexed linkage means for use in the system of FIG. 1 .
FIG. 3 is a perspective view of a stabilization arm connection for use in the system of FIG. 1 .
FIG. 4 is a perspective view of a stabilization interface device for use in the system of FIG. 1 .
FIG. 5 is a perspective view of a stabilization bracket and interface device for use with the system of FIG. 1 .
FIG. 6 is a side view of an alternative stabilization mechanism for use with the system of FIG. 1 .
FIG. 7 is a perspective view of another portable patient lifting device according to the present description.
FIG. 8 is a side view of a mobility base with center load-bearing wheels in a third embodiment according to the present description.
FIG. 9 is a side view of the embodiment of FIG. 8 with its center wheels raised.
FIG. 10 is a side view of the embodiment of FIG. 8 with its center wheels lowered.
DESCRIPTION
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to certain embodiments illustrated in the disclosure, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Generally, this disclosure relates to a device and an associated method for transferring a person having a handicap from one location to another, such as transferring between a wheelchair and a bathtub, or between a wheelchair and a bed. One embodiment described herein includes five major components: a mobility base, a post and lifter arm, a stabilization arm, a stabilization interface, and a stabilization bracket. A perspective view of this embodiment is shown in FIG. 1 .
Mobility base 110 comprises a tubular frame with side members 112 and cross member 114 , with casters 116 attached to effect mobility of the lifter 100 . The casters 116 can all be locked, when required, for positional stability of the lifter 100 . Each caster 116 swivels when unlocked. The casters 116 lock and unlock simultaneously upon activation of a single lever, footpad, or other control mechanism (not shown). When casters 116 are locked, they can neither swivel about the caster stem bearings, nor roll about the caster axles. The base side pieces 112 and 114 can be moved so as to increase the width of the base to optimize lifter stability when desired, or to effect transfers from wider wheelchairs, lift chairs, or the like.
Lifter post 120 is attached to a cross member 114 of the mobility base frame 110 . The lifter post 120 in this embodiment is removable from the base to allow for shipping, transporting in a vehicle, storage, and the like. The post can be attached at multiple locations along the cross member 114 of the base frame 110 in order to reduce the required length of the lifter arm 125 and stabilization arm 130 . Attached to the lifter post 120 is a lifter arm 125 . The lifter arm 125 is attached to the post 120 with an offset pivot point 127 (so it has a short end 128 and a long end 129 ) so it pivots up and down to allow a client to be lifted over the wall of a bathtub, off of a bed, etc. while hanging from the long end 129 of the lifter arm 125 in a sling (not shown). An actuator device 122 is attached to the short end 128 of the lifter arm 125 and to a position on lifter post 120 below pivot point 127 , to provide the mechanical push and pull required to pivot (raise or lower) the lifter arm 125 as required during use. The actuator device 122 and lifter arm 125 are attached to the post in such a way that they can pivot 360 degrees about the post 120 to perform side and rear transfers as required. Push handles 124 for maneuvering the lifter are also attached to the lifter post 120 .
A stabilization arm 130 is attached to the lifter post 120 in a way that allows it to be rotated 360 degrees about indexed linkage means 132 at the top of the lifter post 120 , and is securely indexed at multiple angles to the post to effect transfers in multiple relative angular configurations. (See also FIGS. 2-3 .) The stabilization arm 130 is designed to fold out of the way when not in use, or to be detached if the device is being used only as a traditional lifter. The stabilization arm is adjustable in length to effect transfers in multiple configurations and situations. The attachment point of stabilization arm 130 to the lifter post 120 can be varied in height to effect transfers in multiple configurations.
A stabilization interface device 140 is attached to the end of the stabilization arm 130 opposite to the post attachment point. As illustrated in FIG. 4 , the stabilization interface device 140 is attached pivotally to the stabilization arm 130 to allow stabilization of the lifter in multiple configurations. It contains a mechanism that assures a rigid, safe connection with the stabilization bracket 150 (see FIG. 5 ). This attachment is robust, but is easily engaged and disengaged. In some embodiments, once the transfer is complete, the stabilization interface device 140 can be remotely detached from the stabilization bracket 150 so the lifter can be moved. This remote detachment is enabled in various embodiments by cables, pulleys, levers, motors, servos, and other mechanisms and techniques as will occur to those skilled in the relevant areas of technology in light of this disclosure.
As shown in FIG. 5 , a stabilization bracket 150 is securely attached to a wall in the vicinity of the transfer site. The stabilization interface device 140 on the end of the stabilization arm 130 securely latches to the wall-mounted stabilization bracket 150 to stabilize the lifter relative to the wall during transfers. In particular, spring-loaded pin 145 is urged into hole 155 when the three plates of stabilization interface device 140 are properly positioned around the three exposed sides of stabilization bracket 150 . This arrangement substantially prevents vertical movement of stabilization arm 130 when the mechanism is attached, but allows rotational movement about pin 135 , which permits placement in a variety of positions even where only a single stabilization bracket 150 is available. Multiple stabilization brackets 150 can be placed in different locations to enable stabilized transfers at each one, and several additional variations in configuration will be understood by those skilled in the relevant technology in view of this disclosure.
FIG. 6 illustrates an alternative stabilization mechanism for use with the disclosed system. In this embodiment, stabilization arm 130 again rotates about pivot pin 135 to enable placement of post 120 in a variety of relative positions. In this attachment mechanism, however, stabilization interface device 240 has a wider opening than that of stabilization interface device 140 , and bracket 250 has matching angles between its outer faces. Further, stabilization interface device 240 has stabilization retainer 245 , which rests in slot 255 of stabilization bracket 250 when the device is securely in place. Stabilization retainer 245 in some embodiments is fixedly attached to the underside of the top panel of stabilization interface device 240 , while in others it is only temporarily secured in position but can rotate up and out of the way as the components are joined, or can be slid into channel 255 from the end of the channel. Alternative placements, forms, arrangements, and even attachment techniques will occur to those skilled in the art based on this disclosure.
Another embodiment, illustrated in FIG. 7 , is a portable patient lifting device 300 normally comprising a base 302 with two front and two rear swiveling casters 304 that provide mobility for the unit, a post 306 vertically attached to the base 302 , and a lifter arm 308 rotationally attached to the top of the post 306 . The design also has attached to the base 302 , between the front and rear casters 304 , at least two, but possibly more, adjustable load-bearing drive wheels 310 that do not swivel as casters do. These “load-bearing wheels” 310 are adjustable in height in relation to the bottom of the lifter base 302 and the four casters 304 , so the load-bearing wheels 310 can, when desired, be adjusted to be lower in height than the base 302 and casters 304 , essentially allowing them to bear more of the load of the lifter system 300 than the four swiveling casters 304 do. When the load-bearing wheels 310 are in this position, this adjustment essentially decreases the load on the axles and swivel bearings of the four casters 304 , thereby decreasing the effort required for a person to push or pull the lifter system 300 .
An added benefit of the lowered position of the load-bearing wheels 310 is that the lifter 300 is easier for a caregiver to maneuver because it tracks in a more straight line over distances, and turns more easily in confined spaces, such as in situations where a sharp 90-degree turn maneuver is required to go from a hallway through a door, etc. The load-bearing wheels 310 can be raised to allow the lifter 300 to be maneuvered freely in all directions, unlimited by the friction of the load-bearing wheels 310 against the surface, and to allow the four casters 302 to provide maximum stability during transfer of a patient. The adjustment in height of the load-bearing wheels 310 can be accomplished in many ways that will occur to those skilled in the art based on the present disclosure. In one example, the adjustment is accomplished by a rotating cam attached to a lever or some other mechanical device that reliably and easily accomplishes the vertical adjustment of the load-bearing wheels. In other examples, the adjustment is achieved by powered and/or hydraulic-assisted mechanisms.
In some variations of this embodiment, the horizontal position of the load-bearing wheels 310 along the frame of the base 302 can also be adjusted, as illustrated by the non-vertical arrows near wheels 310 in FIG. 7 . The adjustment is normally from front-to-back between the four casters 302 , allowing the load-bearing wheels 310 to be placed, as necessary or preferred, directly below the center of mass of the lifter. This adjustability allows users to optimize the stability, maneuverability, and versatility of the lifter 300 .
One variation of the placement, operation, and movement of load-bearing wheels 310 is shown in FIGS. 8-10 . The front and rear ACME screw posts 406 a and 406 b are rigidly connected to the top surface of the lifter base. The ACME screw 401 is held in vertical and horizontal alignment by the front and rear ACME screw posts 406 a and 406 b , and the four shaft collars 404 . The ACME screw 401 is allowed to rotate freely through holes drilled in the front and rear screw posts 406 a and 406 b . The shaft collars 404 prevent the ACME screw from moving horizontally in relation to the ACME screw posts 406 a and 406 b . As the ACME screw 401 is rotated with the ACME screw crank handle 405 , the ACME screw nut 402 and the wedge 403 , which are rigidly connected to each other, move back and forth along the lifter base 409 . The center load bearing wheel assembly 407 is attached to the underside of the lifter base 409 by a pivot point 408 .
The ACME screw nut 402 and wedge 403 are positioned in relation to the load bearing wheel pivot point 408 so that, as the ACME screw nut 402 and wedge 403 are moved back and forth by rotation of the ACME screw 401 , the center load bearing wheel assembly 407 moves up (see FIG. 9 ) and down (see FIG. 10 ) in relation to the front and rear casters 411 . This wedging action effectively offloads the front and rear casters 411 , allowing the lifter to be pushed, pulled, and maneuvered much more easily.
In other variations on the lifter of FIG. 1 , only two of the wheels are castors, while two others (such as the “rear” wheels on the corners nearest the post) are wheels that are held in fixed orientation relative to the lifter base. This configuration provides somewhat better straight-line tracking than the four-castor version.
While the inventions have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that the preferred embodiment has been shown and described and that changes and modifications that come within the spirit of the invention are desired to be protected. | A device and associated method transfer a person having a handicap from one location to another, such as into or out of a wheelchair, bed, or bathtub. A wheeled base provides mobility to the device. A post and lifter arm support the patient during the transfer. The post is connected to a stabilization arm, which temporarily connects using a stabilization interface to a stabilization bracket. The stabilization bracket is typically attached rather permanently to a wall, ceiling, or other structural feature that provides substantial stability to the system. In various embodiments, the lifter arm may be actuated by hydraulics, the stabilization arm may be extendable, and a pair of extra wheels on the mobility base are adjustable horizontally (e.g., along one hedge of the base frame) or vertically (down to decrease the load on the casters, or up to allow the lifter to be “crabbed” sideways in confined spaces). | 0 |
RELATED APPLICATIONS
This application claims the benefit of priority to U.S. Provisional Patent Application No. 61/179,793 filed May 20, 2009, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to oligonucleotide substrates, as well as for their uses, for example, as probes for nucleic acid amplification reactions.
BACKGROUND OF THE INVENTION
Enzymes which metabolize nucleic acids in a manner specified by primary sequence, backbone structure, or a base character (often damaged or modified base) are of utility in biotechnology applications. Several families of such enzymes are used routinely in nucleic acid-based techniques and include restriction endonucleases, polymerases, ligases and exonucleases. Additionally, a variety of single-subunit (non-restriction) endonucleases which rely not on specific sequence strings but on recognising unusual, damaged or missing bases have been described over the years. These enzymes can be loosely divided into 2 groups—the AP endonucleases, of which E. coli endonuclease IV (Nfo) and E. coli exonuclease III are examples, and the DNA glycosylase/lyase family of which E. coli fpg, MUG and Nth are examples.
The AP endonucleases are characterised by the ability to recognise and cleave the sugar-phosphate backbone at abasic sites (other enzymatic activities may also be present) when found in the context of duplex DNA. Recognition and incision at abasic sites occurs in a biochemical manner that is distinct to the glycosylase/lyase family and not by beta-elimination or beta/delta-elimination. Consequently they attack not only true abasic sites but other substrates including tetrayhydrofuran moieties which lack an oxygen atom on the 1′ carbon of the sugar ring (Takeshita et al., 1987, J Biol Chem. 262(21):10171) (see FIG. 1 for chemical structures).
In contrast, glycosylase/lyase enzymes including the fpg protein (8-oxoguanine DNA glycosylase, fpg in E. coli and OGG1 in mammals) or Nth proteins (endonuclease III in E. coli , Nth1 in humans, etc.) function in a 2-stage catalytic manner in which damaged bases are first recognized and excised via formation of a Schiff base between the protein and the DNA, and secondly the abasic site thus generated is processed by beta-elimination or beta-delta elimination in a manner distinct to the AP endonucleases. In this case tetrahydrofuran (THF) residues are not a substrate for lyase activity as no C1′ oxygen atom is present in this abasic mimic and such sugars lacking oxygen at the 1′ position are resistant to attack (Takeshita et al., 1987) ( FIG. 1 ).
The use of AP endonucleases and glycosylase/lyases in molecular biology techniques has been described. One application is the use of these enzymes to process substrates generated during in vitro DNA amplification reactions, or similar kinds of applications, and in particular when a synthetic ‘probe’ oligonucleotide has been provided containing modified sugars or bases which can become a substrate for the enzymes if the synthetic oligonucleotide hybridizes specifically to molecules in the sample. An example of such an application is given in U.S. Pat. No. 7,435,561 B2 and Piepenburg et al., PlosBiology, 2006 4 (7):e204 in which tetrahydrofuran-modified oligonucleotides are used as substrates for the E. coli Nfo (endonuclease IV) protein as a method to measure DNA amplification (Nfo is one of the two AP endonucleases of E. coli ).
Application of glycosylase/lyases to similar strategies can also be envisioned. The ability of fpg protein to similarly process modified bases such as 8-oxoguanine within a DNA amplification reaction for the purposes of reaction-monitoring has been described (U.S. Pat. No. 7,435,561 B2). Furthermore the fact that glycosylase/lyase enzymes such as fpg and Nth do not leave 3′ extendable ends but rather blocked 3′ ends (due to the differences in catalytic mode) may have particular utility in circumstances in which one wishes to ensure that the processed probe cannot be a ready substrate for polymerases or other activities dependent on a 3′ hydroxyl moiety.
Despite the potential of these enzymes, they possess certain features that make them unattractive for use in some applications. Notably, unlike the THF residue, true abasic sites required for the backbone-incising activity of DNA lyases are not stable under physiological conditions and are quickly hydrolyzed in aqueous solutions making them impractical for use in most molecular procedures. Instead specific damaged bases can be incorporated and used as the primary substrates for the glycosylase activity to generate the abasic site transiently before backbone hydrolysis by the lyase activity. Unfortunately however, typical damaged base analogs such as 8-oxoguanine (fpg) or thymidine glycol (Nth) tend to be rather expensive to synthesize and also impart sequence requirements on the probe as ideally they must be paired opposite specific bases on the opposing strand. In principle it would be far more convenient to have a stable substrate analogous to the generic THF residue that can be employed for AP endonucleases but retaining reactivity with the lyase activity of glycosylase/lyase enzymes.
Here we show that the fpg protein, as well as the AP endonuclease IV of E. coli (Nfo), efficiently cleaves DNA backbones containing a variety of substrates that lack a base but contain a 1′-oxygen atom covalently attached to a carbon-based linker [C]n. The linker can itself be used to attach other moieties such as biotin, fluorophores and other coupled groups, particularly useful if an amine-ended linker can be used to couple a variety of agents. Surprisingly, nucleotides having this arrangement and referred to generally as dR-O—[C]n appear to be good substrates of the fpg protein in a number of contexts, and are also substrates for the endonuclease IV protein, but appear relatively poor substrates for E. coli exonuclease III. We anticipate the use of oligonucleotides containing such dR-O—[C]n groups as substrates in a number of circumstances, in particular within in vitro reactions such as part of detection strategies for nucleic acid detection methods. The length of the linker used in this study is 6 carbon atoms, as available on certain commercially available nucleotides, however it is anticipated that a variety of carbon chain lengths might be employed and that it is the carbon-oxygen-carbon structure with little subsequent steric bulking that affords these structures sufficient plasticity to the enzymes.
SUMMARY OF THE INVENTION
The present invention relates in part to the discovery that AP endonucleases, DNA glycosylases, an DNA glycosylase/lyases, such as fpg and Nfo proteins, can catalyze the breaking of the DNA backbone at sites containing dR-O—[C]n residues in which no base is present at the C1′ position of the sugar, but that retains an oxygen atom at that position. The oxygen atom bridges the sugar to a carbon atom of a carbon linker with n (e.g., 1-8) carbon atoms (i.e., [C]n). Consequently nucleic acid probes can be constructed containing dR-O—[C]n residues by the use of commercially available phosphoramidites and can be substrates for AP endonucleases and DNA glycosylase/lyase enzymes if they form duplexes with complementary nucleic acids. A variety of moieties may be coupled to the linker portion of the dR-O—[C]n including fluorophores and other labels suggesting a number of strategies to detect successful processing of the probe as evidence of presence of a specific target nucleic acid. Applicants show how probes may be constructed using fluorescent molecules and quenchers using dR-O—[C]n as targeting sites for fpg, Nfo or other potential AP endonucleases or lyases. Applicants contemplate other uses of the dR-O—[C]n substrates in other detection schemes. For example, the dR-O—[C]n residue may be conjugated to a detactable label, where the activity of the nuclease frees the label, which can then be detected either immediately or via a subsequent process, via a measurable difference between the conjugated and free state.
In one aspect, processes are provided herein for cleaving an oligonucleotide containing a dR-O—[C]n residue that forms a duplex with a nucleic acid, by contacting the duplex with a nuclease selected from an AP endonucleases, or DNA glycosylases, or an DNA glycosylase/lyases. In some embodiments, the nuclease is endonuclease IV (Nfo) or 8-oxoguanine DNA glycosylase (fpg). In some embodiments, the linker is a 3-6 carbon atom linker (e.g., a 6 carbon atom linker). In some embodiments, the oligonucleotide is blocked at its 3′-end to prevent polymerase extension. In some embodiments, the linker is conjugated to a detectable label (e.g., biotin, digoxygenin, peptide, fluorophore, quencher, antibody or a quantum dot).
In some embodiments, the process further comprises the step of contacting the oligonucleotide with the nucleic acid to form the oligonucleotide/nucleic acid duplex. In some embodiments, this comprises hybridizing the oligonucleotide to the nucleic acid. In some embodiments, this comprises (i) contacting the oligonucleotide with a recombinase to form a recombinase/oligonucleotide complex; and (ii) contacting the recombinase/oligonucleotide complex to the nucleic acid to form the oligonucleotide/nucleic acid duplex. In some embodiments, the nucleic acid is the product of a nucleic acid amplification reaction (e.g., a recombinase polymerase amplification (RPA) process or a polymerase chain reaction (PCR)).
In some embodiments, the process further comprises the step of detecting cleavage of the oligonucleotide. In some embodiments, the detection is monitored in real time. In some embodiments, the detection is monitored at an endpoint for the reaction.
In some embodiments, the oligonucleotide contains a fluorophore and a quencher, where one of the fluorophore or the quencher is conjugated to the carbon linker. The nuclease activity excises the conjugated fluorophore or quencher from the oligonucleotide and the detection step comprises measuring a difference, if any, in fluorescence between the conjugated and free state.
In another aspect, processes are provided herein for detecting the presence or absence of a target nucleic acid. The processes comprise the following steps: (a) contacting an oligonucleotide probe containing a dR-O—[C]n residue or nucleotide with the target nucleic acid to form a probe/nucleic acid duplex; (b) contacting the duplex with a nuclease selected from an AP endonucleases, or DNA glycosylases, or an DNA glycosylase/lyases to excise the linker from the complex and/or specifically cleave the probe at the dR-O—[C]n nucleotide; and (c) detecting whether such excision or cleavage has occurred. In some embodiments, the nucleic acid is the product of a nucleic acid amplification reaction (e.g., a recombinase polymerase amplification (RPA) process or a polymerase chain reaction (PCR)). In some embodiments, the amplification reaction is monitored in real time. In some embodiments, the amplification reaction is monitored at an endpoint for the reaction.
In some embodiments, the duplex is formed by hybridizing the probe to the nucleic acid. In some embodiments, the duplex is formed by (i) contacting the probe with a recombinase to form a recombinase/probe complex; and (ii) contacting the recombinase/probe complex to the nucleic acid to form the probe/nucleic acid duplex.
In some embodiments, the nuclease is endonuclease IV (Nfo) or 8-oxoguanine DNA glycosylase (fpg). In some embodiments, the linker is a 3-6 carbon atom linker (e.g., a 6 carbon atom linker). In some embodiments, the oligonucleotide is blocked at its 3′-end to prevent polymerase extension. In some embodiments, the linker is conjugated to a detectable label (e.g., biotin, digoxygenin, peptide, fluorophore, quencher, antibody or a quantum dot).
In some embodiments, the probe contains a fluorophore and a quencher, where one of the fluorophore or the quencher is conjugated to the carbon linker. For example, the fluorophore and the quencher are separated by 4-6 bases in the probe. In some embodiments, the fluorophore or the quencher that is not conjugated to the carbon linker is conjugated to the end (e.g., the 5′-end) of the probe. The nuclease activity excises and frees the conjugated fluorophore or quencher associated with the dR-O—[C]n residue from the probe and the detection step comprises measuring a difference, if any, in fluorescence between the conjugated and free state.
In another aspect, provided herein are oligonucleotide probes containing a dR-O—[C]n residue. In some embodiments, the probes are 30 to 60 nucleotides in length and contain a fluorophore quencher pair separated by 10 nucleotides or less (e.g., 4-6 nucleotides), where either the fluorophore or the quencher is conjugated to the dR-O—[C]n residue. In some embodiments, the linker is a 3-6 carbon atom linker (e.g., a 6 carbon atom linker). In some embodiments, the oligonucleotide is blocked at its 3′-end to prevent polymerase extension. In some embodiments, the fluorophore or the quencher that is not conjugated to the dR-O—[C]n residue is conjugated to the end (e.g., the 5′-end) of the probe. In some embodiments, the probes are 30 to 40 nucleotides (e.g., 35 nucleotides) in length.
In yet another aspect, provided herein are kits comprising (i) an oligonucleotide containing a dR-O—[C]n residue, and (ii) a nuclease selected from an AP endonucleases, or DNA glycosylases, or an DNA glycosylase/lyases. In some embodiments, the nuclease is endonuclease IV (Nfo) or 8-oxoguanine DNA glycosylase (fpg).
In yet a further aspect, provided herein are reaction mixtures comprising an oligonucleotide containing a dR-O—[C]n residue and a nuclease selected from an AP endonucleases, or DNA glycosylases, or an DNA glycosylase/lyases (e.g., endonuclease IV (Nfo) or 8-oxoguanine DNA glycosylase (fpg)). In some embodiments, the linker is a 3-6 carbon atom linker (e.g., a 6 carbon atom linker). In some embodiments, the oligonucleotide is blocked at its 3′-end to prevent polymerase extension. In some embodiments, the linker is conjugated to a detectable label (e.g., biotin, digoxygenin, peptide, fluorophore, quencher, antibody or a quantum dot). In some embodiments, the reaction mixture is freeze dried or lyophilized.
In some embodiments, the reaction mixture further comprises a container. For example, the reaction mixture can be contained in a tube or in a well of a multi-well container. The reaction mixtures may be dried or attached onto a mobile solid support such as a bead or a strip, or a well.
In some embodiments, the reaction mixture further comprises a target or template nucleic acid that contains a sequence that is complementary to the oligonucleotide.
Other embodiments, objects, aspects, features, and advantages of the invention will be apparent from the accompanying description and claims. It is contemplated that whenever appropriate, any embodiment of the present invention can be combined with one or more other embodiments of the present invention, even though the embodiments are described under different aspects of the present invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 Chemical structures: general structure of a normal abasic site containing a hydroxyl at the 1′ carbon position, of a tetrahydrofuran (THF) residue containing a hydrogen at the 1′ position, of the general dR-O—[C]n group indicating the position of the carbon-oxygen-carbon bridge between the C1′ of the DNA ribose group and the linker to the attached marker moiety, and finally of the dR-biotin nucleotide used in Example 1 and conforming to the dR-O—[C]n structure described.
FIG. 2 dR-biotin probe design: sequence (SEQ ID NO:3) and schematic representation of the oligonucleotide probe used to assess cleavage activity of Nfo and fpg proteins during RPA reactions in which a target sequence matching the probe sequence is amplified. The sequence of the oligonucleotide is indicated. The primer is labelled at the 5′ end with the FAM fluorophore, contains a dR-biotin within the body of the sequence, and is blocked by virtue of a 2′,3′dideoxycytidine residue.
FIG. 3 Comparison of amplification reactions lacking nuclease or containing Nfo or fpg enzyme: reveals that both enzymes can process the dR-biotin moiety giving rise to a faster migrating cleavage product and in the case of Nfo a product produced by extension of the cleavage product.
FIG. 4 Oligonucleotide probe design: example of a probe design, including an oligonucleotide body (here 35 nucleotides in length), a 5′-quencher modification (here a 5′-BHQ1), an internal dR-fluorophore nucleotide analogue in proximity to the quencher (here a dR-FAM at oligonucleotide position 6) and a 3′ polymerase extension block.
FIG. 5 Sensitivity and specificity: results of real-time fluorescence monitoring of two template titration experiments for the indicated human genomic targets using DNA dR-probes. In both cases the increase of fluorescence signal (relative to the baseline at 0 to 3 minutes) is only observed in reactions containing template and not in the no-template control. The onset time of the signal increase correlates with the amount of starting template (1000, 100 or 10 copies). Reaction time is in minutes (X-axis), fluorescence in arbitrary fluorescence units (Y-axis).
FIG. 6 Performance of different probes: results of real-time fluorescence monitoring of four sets of RPA reactions (in duplicates) for the indicated human genomic targets using DNA oligonucleotide probes of the design outlined in FIG. 2 . The increase in fluorescence between 6 and 8 minutes results from the fpg-dependent processing of the dR-groups of the probes (here dR-FAM) and indicates ongoing DNA amplification and thus the presence of the target DNA template. Reaction time is in minutes (X-axis), fluorescence in arbitrary fluorescence units (Y-axis).
DETAILED DESCRIPTION OF THE INVENTION
The details of one or more embodiments of the invention are set forth in the accompanying description below. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the methods and materials are now described. Other features, objects, and advantages of the invention will be apparent from the description. In the specification, the singular forms also include the plural unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the case of conflict, the present Specification will control.
The combination of enzymes with synthetic substrates for use in laboratory assays and manipulations is well known in the art. DNA repair endonucleases such as the glycosylases fpg and Nth, as well as AP endonucleases such as E. coli exonuclease III and endonuclease IV, are good examples of this combination—it is easy to generate synthetic substrates for these DNA repair enzymes by the use of modern oligonucleotide synthesis regimes and the wide existing variety of synthetic nucleotides that may be incorporated into DNA primers. These DNA repair enzymes can be readily employed for a variety of purposes, and one which has been recently exploited is their use as agents to assist the monitoring of isothermal Recombinase Polymerase Amplification (RPA) reactions.
RPA is a process in which recombinase-mediated targeting of oligonucleotides to DNA is coupled to DNA synthesis by a polymerase (U.S. Pat. No. 7,270,981 B2; U.S. Pat. No. 7,399,590; U.S. Pat. No. 7,435,561 B2; U.S. Pat. No. 7,485,428 B2; U.S. Pat. No. 7,666,598 B2 and foreign equivalents). RPA depends upon components of the cellular DNA replication and repair machinery, and relies upon establishment of a ‘dynamic’ recombination environment having adequate rates of both recombinase loading and unloading that maintains high levels of recombination activity achieved in the presence of specific crowding agents. RPA has the advantage that it combines the sensitivity, specificity and most other features of PCR but without the need for thermocycling and with extraordinary speed and robustness to off-temperature set-up. RPA has already benefited from the potential employment of a wide variety of nucleic acid processing enzymes such as known repair endonucleases which have been untapped by other processes because of either the need for thermostable equivalents or because they demonstrate poor regulation without accessory proteins such as single-stranded DNA binding proteins, a natural component of RPA reactions.
Briefly, RPA comprises the following steps: First, a recombinase agent is contacted with a first and a second nucleic acid primer to form a first and a second nucleoprotein primer. Second, the first and second nucleoprotein primers are contacted to a double stranded target sequence to form a first double stranded structure at a first portion of said first strand and form a double stranded structure at a second portion of said second strand so the 3′ ends of said first nucleic acid primer and said second nucleic acid primer are oriented towards each other on a given template DNA molecule. Third, the 3′ end of said first and second nucleoprotein primers are extended by DNA polymerases to generate first and second double stranded nucleic acids, and first and second displaced strands of nucleic acid. Finally, the second and third steps are repeated until a desired degree of amplification is reached.
Earlier work has demonstrated the extreme utility of the synthetic nucleotide tetrahydrofuran (THF) in the development of probe systems for the RPA method (Piepenburg et al., 2006; U.S. Pat. No. 7,435,561 B2). This base analog is oftentimes used to mimic abasic sites and has the natural advantage that it is stable—replacement of the 1′-hydroxyl of a natural abasic site with a hydrogen atom renders the nucleotides stable and unable to undergo spontaneous ring-opening and oligonucleotide fragmentation. This analog is readily available and cheap to incorporate into oligonucleotides. Due to differences in biochemical mechanism, however, while the E. coli AP endonucleases Nfo and ExoIII can cleave at such THF residues in synthetic primers, other DNA glycoslyase/lyases cannot. These latter enzymes normally require a damaged base (glycosylase activity) and/or the presence of a hydroxyl group at the 1′-position of the sugar (lyase activity) and THF is completely inert to their enzymatic activities. This presents something of a nuisance as these glycosylase/lyase enzymes could be useful tools also for in vitro reactions such as those in which a probe is processed in response to target DNA accumulation in RPA, or in other contexts and methods. More natural substrates, for example 8-oxoguanine for fpg, can be inserted into oligonucleotides to generate cleavage sites for these glycosylase/lyases, however these modifications are usually expensive, and furthermore often restrict the base which can be opposed to the modified nucleotide. Cheaper and more general nucleotide modifications which are substrates for these enzymes would be of great utility.
In an effort to explore the effects of a number of unusual base analogs as substrates for DNA repair enzymes we synthesised oligonucleotides containing nucleotides completely lacking a base, but retaining a carbon-oxygen-carbon linkage at the 1′ position of the sugar. Such nucleotide reagents are readily available and inexpensive, and are commonly used to incorporate labelling groups such as fluorophores or biotin into oligonucleotides within the body of the oligonucleotide. Commonly the carbon atom linked through oxygen to the 1′ carbon of the sugar is the first carbon atom of a linker which often ultimately ends with the labelling group, or alternatively an amine or other chemical moiety (e.g., a thiol) to which reagents may be readily coupled. Such reagents are often described in the literature as dR-X in which the dR refers to deoxyribose, and the X will often be linker-amine, or linker-fluorophore, or linker-biotin, or some other group or label. No-one has previously explored whether or not repair endonucleases would recognise such structures which lack a base but retain a carbon-oxygen-carbon covalent linkage at the 1′ sugar position. The absence of a hydroxyl means that the ring-opening processes of lyases should not operate without prior processing of the linker group and its associated excision. As known glycosylases normally operate on damaged bases rather than unusual carbon linkers there was no precedent to suggest that these dR-O—[C]n groups would be substrates for DNA glycosylase/lyases such as fpg.
FIG. 1 shows the general structure of a dR-O—[C]n group, as well as specifically the structure of the dR-biotin reagents as incorporated into oligonucleotides used herein and purchased from Eurogentec, Belgium. Such reagents used herein have a common 6 carbon atom linker between the 1′-sugar and a nitrogen atom which is often used to couple other reagents before or after oligonucleotide synthesis. In this study the biotin moiety of the dR-biotin oligonucleotide is linked via this nitrogen atom as an amide bond and then through a further 4 carbon atom linker. Other label reagents used in this study—dR-FAM and dR-Texas Red—are similarly arranged in which a fluorophore is coupled through an amide bond at the end of the 6 carbon atom linker.
A detectable label is defined as any moiety that may be detected using current methods. These labels include, at least, a fluorophore (also called a fluorescent molecule, fluorochrome), an enzyme, a quencher, an enzyme inhibitor, a radioactive label, a member of a binding pair, a digoxygenin residue, a peptide, and a combination thereof.
“A member of a binding pair” is meant to be one of a first and a second moiety, wherein said first and said second moiety have a specific binding affinity for each other. Suitable binding pairs for use in the invention include, but are not limited to, antigens/antibodies (for example, digoxigenin/anti-digoxigenin, dinitrophenyl (DNP)/anti-DNP, dansyl-X-anti-dansyl, Fluorescein/anti-fluorescein, lucifer yellow/anti-lucifer yellow, peptide/anti-peptide, ligand/receptor and rhodamine/anti-rhodamine), biotin/avidin (or biotin/streptavidin) and calmodulin binding protein (CBP)/calmodulin. Other suitable binding pairs include polypeptides such as the FLAG-peptide (DYKDDDDK; SEQ ID NO: 16) [Hopp et al., BioTechnology, 6:1204 1210 (1988)]; the KT3 epitope peptide (Martin et al., Science 255:192 194 (1992)); tubulin epitope peptide (Skinner et al., J. Biol. Chem 266:15163 15166 (1991)); and the T7 gene 10 protein peptide tag (Lutz-Freyermuth et al., Proc. Natl. Acad. Sci. USA, 87:6393 6397 (1990)) and the antibodies each thereto. Generally, in a preferred embodiment, the smaller of the binding pair partners serves as the detectable label, as steric considerations may be important.
In one aspect, processes are provided herein for cleaving an oligonucleotide containing a dR-O—[C]n residue that forms a duplex with a nucleic acid, by contacting the duplex with a nuclease selected from an AP endonucleases, or DNA glycosylases, or an DNA glycosylase/lyases. In some embodiments, the nuclease is endonuclease IV (Nfo) or 8-oxoguanine DNA glycosylase (fpg). In some embodiments, the linker is a 3-6 carbon atom linker (e.g., a 6 carbon atom linker). In some embodiments, the oligonucleotide is blocked at its 3′-end to prevent polymerase extension. In some embodiments, the linker is conjugated to a detectable label (e.g., biotin, digoxygenin, peptide, fluorophore, quencher, antibody or a quantum dot).
In some embodiments, the process further comprises the step of contacting the oligonucleotide with the nucleic acid to form the oligonucleotide/nucleic acid duplex. In some embodiments, this comprises hybridizing the oligonucleotide to the nucleic acid. In some embodiments, this comprises (i) contacting the oligonucleotide with a recombinase to form a recombinase/oligonucleotide complex; and (ii) contacting the recombinase/oligonucleotide complex to the nucleic acid to form the oligonucleotide/nucleic acid duplex. In some embodiments, the nucleic acid is the product of a nucleic acid amplification reaction (e.g., a recombinase polymerase amplification (RPA) process or a polymerase chain reaction (PCR)).
In some embodiments, the process further comprises the step of detecting cleavage of the oligonucleotide. In some embodiments, the detection is monitored in real time. In some embodiments, the detection is monitored at an endpoint for the reaction.
In some embodiments, the oligonucleotide contains a fluorophore and a quencher, where one of the fluorophore or the quencher is conjugated to the carbon linker. The nuclease activity excises the conjugated fluorophore or quencher from the oligonucleotide and the detection step comprises measuring a difference, if any, in fluorescence between the conjugated and free state.
In another aspect, processes are provided herein for detecting the presence or absence of a target nucleic acid. The processes comprise the following steps: (a) contacting an oligonucleotide probe containing a dR-O—[C]n residue or nucleotide with the target nucleic acid to form a probe/nucleic acid duplex; (b) contacting the duplex with a nuclease selected from an AP endonucleases, or DNA glycosylases, or an DNA glycosylase/lyases to excise the linker from the complex and/or specifically cleave the probe at the dR-O—[C]n nucleotide; and (c) detecting whether such excision or cleavage has occurred. In some embodiments, the nucleic acid is the product of a nucleic acid amplification reaction (e.g., a recombinase polymerase amplification (RPA) process or a polymerase chain reaction (PCR)). In some embodiments, the amplification reaction is monitored in real time. In some embodiments, the amplification reaction is monitored at an endpoint for the reaction.
In some embodiments, the duplex is formed by hybridizing the probe to the nucleic acid. In some embodiments, the duplex is formed by (i) contacting the probe with a recombinase to form a recombinase/probe complex; and (ii) contacting the recombinase/probe complex to the nucleic acid to form the probe/nucleic acid duplex.
In some embodiments, the nuclease is endonuclease IV (Nfo) or 8-oxoguanine DNA glycosylase (fpg). In some embodiments, the linker is a 3-6 carbon atom linker (e.g., a 6 carbon atom linker). In some embodiments, the oligonucleotide is blocked at its 3′-end to prevent polymerase extension. In some embodiments, the linker is conjugated to a detectable label (e.g., biotin, digoxygenin, peptide, fluorophore, quencher, antibody or a quantum dot).
In some embodiments, the probe contains a fluorophore and a quencher, where one of the fluorophore or the quencher is conjugated to the carbon linker. For example, the fluorophore and the quencher are separated by 4-6 bases in the probe. In some embodiments, the fluorophore or the quencher that is not conjugated to the carbon linker is conjugated to the end (e.g., the 5′-end) of the probe. The nuclease activity excises and frees the conjugated fluorophore or quencher associated with the dR-O—[C]n residue from the probe and the detection step comprises measuring a difference, if any, in fluorescence between the conjugated and free state.
In another aspect, provided herein are oligonucleotide probes containing a dR-O—[C]n residue. In some embodiments, the probes are 30 to 60 nucleotides in length and contain a fluorophore quencher pair separated by 10 nucleotides or less (e.g., 4-6 nucleotides), where either the fluorophore or the quencher is conjugated to the dR-O—[C]n residue. In some embodiments, the linker is a 3-6 carbon atom linker (e.g., a 6 carbon atom linker). In some embodiments, the oligonucleotide is blocked at its 3′-end to prevent polymerase extension. In some embodiments, the fluorophore or the quencher that is not conjugated to the dR-O—[C]n residue is conjugated to the end (e.g., the 5′-end) of the probe. In some embodiments, the probes are 30 to 40 nucleotides (e.g., 35 nucleotides) in length.
In yet another aspect, provided herein are kits comprising (i) an oligonucleotide containing a dR-O—[C]n residue, and (ii) a nuclease selected from an AP endonucleases, or DNA glycosylases, or an DNA glycosylase/lyases. In some embodiments, the nuclease is endonuclease IV (Nfo) or 8-oxoguanine DNA glycosylase (fpg).
In yet a further aspect, provided herein are reaction mixtures comprising an oligonucleotide containing a dR-O—[C]n residue and a nuclease selected from an AP endonucleases, or DNA glycosylases, or an DNA glycosylase/lyases (e.g., endonuclease IV (Nfo) or 8-oxoguanine DNA glycosylase (fpg)). In some embodiments, the linker is a 3-6 carbon atom linker (e.g., a 6 carbon atom linker). In some embodiments, the oligonucleotide is blocked at its 3′-end to prevent polymerase extension. In some embodiments, the linker is conjugated to a detectable label (e.g., biotin, digoxygenin, peptide, fluorophore, quencher, antibody or a quantum dot). In some embodiments, the reaction mixture is freeze dried or lyophilized.
In some embodiments, the reaction mixture further comprises a container. For example, the reaction mixture can be contained in a tube or in a well of a multi-well container. The reaction mixtures may be dried or attached onto a mobile solid support such as a bead or a strip, or a well.
In some embodiments, the reaction mixture further comprises a target or template nucleic acid that contains a sequence that is complementary to the oligonucleotide.
FIG. 2 indicates both primary sequence and schematically the nature of a dR-biotin probe generated for use in an RPA DNA amplification reaction using as a target a DNA molecule containing the sequence specified in the probe. The probe is blocked (to prevent polymerase extension during the amplification phase) and contains an internal dR-biotin as the test substrate for the enzymes. The probe also contains a 5′-FAM. Thus, in principle, if DNA is amplified in a reaction containing this probe there is the possibility that the probe will bind to and interact specifically with the amplified DNA either by ‘classical’ hybridization to complementary single strands formed during amplification, or by recombinase-mediated processes. The outcome of such an experiment is shown in FIG. 3 and described in Example 1 below.
A second set of experiments was performed to investigate the generality of this cleavage activity, and in this case using fluorescent reagents in which the dR-O—[C]n nucleotide is coupled to a fluorophore as depicted in FIG. 4 . In this case the dR-fluorophore is positioned close to the 5′ end of the oligonucleotide probe and in close proximity to a quencher which is attached to the very 5′ end. As before the 3′ end of the probe is suitably blocked to prevent aberrant elongation or primer artefacts. As indicated in FIG. 4 , should the probe form hybrids with complementary amplifying material then it might become a substrate for fpg (or Nfo) and if so could cleave the backbone at this position (and potentially release the fluorophore directly into the aqueous medium detached from either oliogonucleotide fragment if the glycosylase activity is present in fpg or other non-AP endonuclease enzymes). If cleavage occurs there will be physical separation of the fluorophore and quencher and hence an increase in detectable fluorescence in a manner akin to that described earlier for THF-based fluorescent probes utilising E. coli Nfo or exoIII proteins. FIGS. 5 and 6 show the outcome of such experiments and describe in Example 2 in which RPA reactions were performed on human genomic targets utilizing primers and probes specifically directed toward known single nucleotide polymorphism (SNP) regions.
These experiments collectively clearly demonstrate that dR-O—[C]n groups are substrates for the Nfo and the fpg nucleases. Furthermore, it is possible to construct probes containing such groups in a way that the activity of the nucleases on the probe occurs only in the circumstance that complementary nucleic acid strands accumulate permitting duplex formation, thereby allowing determination of whether the amplification has occurred by fluorescence or other mechanisms. Therefore, these dR-O—[C]n nucleotide reagents could be broadly applied in combination with fpg, Nfo or glycosylase/lyase and equivalent enzymes for a variety of uses.
All sequence citations, references, patents, patent applications or other documents cited are hereby incorporated by reference.
EXAMPLES
The present invention is further defined in the following Examples. It should be understood that these Examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can 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 uses and conditions.
Example 1
Oligonucleotides Probes Containing an Internal dR-Biotin are Cut by Nfo and Fpg
In this example it is shown that oligonucleotides probes, depicted schematically in FIG. 2 , containing an internal dR-Biotin can be cut by Nfo and fpg. The reactions (total volume of 150 μL) were mixed from fresh reagents and incubated for 75 minutes at 37° C. Conditions used were 50 mM Tris/Acetate (pH 7.9), 14 mM Mg-Acetate, 100 mM Potassium-Acetate, 2 mM DTT, 200 nM each dNTP, 6% PEG 35,000, 3 mM ATP, 50 mM Phospho-Creatine, 900 ng/μL T4gp32, 120 ng/μL T4uvsX, 30 ng/μL T4uvsY, 360 ng/μL Bac. subtilis DNA polI. Either 3000 copies of DNA template or water (as a negative control) was included as indicated. Nuclease, 200 ng/μL Nfo or 50 ng/μL fpg, was included as indicated. Primers, K2 and J1, were included at 480 nM each and the probe, FpgProb1, was included at 120 nM, with their sequences provided below. Samples were quenched in one volume of 2% SDS/one volume phenol, mixed and incubated for 20 minutes at 65° C. Subsequently samples were phenol/chloroform extracted and twice ethanol precipitated according to standard molecular biology techniques. Half of each sample was then resuspended in formamide loading buffer resolved on a 16.5% denaturing polyacrylamide gel (Urea) and visualised (using the FAM fluorescence) following standard protocols. Markers were 2 pmol of the probe and 2 pmol of a 32 nt marker oligonucleotide.
(SEQ ID NO: 1)
J1
5′-acggcattaacaaacgaactgattcatctgcttgg-3′
(SEQ ID NO: 2)
K2
5′-ccttaatttctccgagaacttcatattcaagcgtc-3′
(SEQ ID NO: 3)
FpgProbe1
5′-6FAM-cagaagtatgaccgtgtctttgaaatg[dR-
biotin]ttgaagaaatggtt[ddC]-3′
The probe and any derivatives were visualised here by virtue of the FAM moiety which emits visible light when excited by UV radiation. Amplification reactions (RPA) containing a target DNA, two (2) appropriate amplification primers, the dR-biotin probe and either no nuclease, Nfo protein, or fpg protein were cleaned following incubation and separated by size on a denaturing acrylamide gel and then exposed to UV. The probe or any derivatives retaining the 5′-FAM are then visible ( FIG. 3 ). In the absence of an added nuclease, the probe, 42 nucleotides long, mostly migrates at its expected location slightly more slowly than a control labelled primer of 32 nucleotides (indicated). A slightly slower-migrating (longer) fragment is also seen as compared to the neat probe not incubated in RPA (#1). This likely arose because the probe can be unblocked slowly by nucleases that are believed to be present in some of the enzyme preparations (nibbling at the 3′ end), and once unblocked it can be extended following hybridization to amplifying target and hence forming a nested amplicon of sorts. In the presence of Nfo however, this phenomenon is much more prominent as expected and a large proportion of the probe is now elongated. Furthermore, the Nfo protein was indeed attacking the dR-O—[C]n residue rather than just ‘polishing’ the 3′ end because some small amount of faster-migrating probe DNA (#2) is also visible indicating cleavage at the dR-O—[C]n location with no subsequent elongation. Finally, when fpg protein was included in the reaction environment a large proportion of faster-migrating cleaved probe is visible and no elongated material is detected, as fpg leaves a blocked 3′-end after cleavage and hence it is not extended by polymerase enzyme present in the mix.
Example 2
Measurement of DNA Amplification with Oligonucleotides Probes Containing an Internal dR-Fluorophore
In this Example, RPA experiments using fluorescent reagents in which the dR-O—[C]n nucleotide is coupled to a fluorophore as depicted in FIG. 4 . In this case, the dR-fluorophore is positioned close to the 5′ end of the oligonucleotide probe and in close proximity to a quencher which is attached to the very 5′ end. As in the previous example, the 3′ end of the probe is suitably blocked to prevent aberrant elongation or primer artefacts.
The reactions (total volume of 50 μL) were performed according to standard RPA protocol for freeze-dried reactions. Briefly, lyophilised reagents were mixed with PEG, Magnesium-Acetate and template, and incubated for 20 minutes at 38° C. in a fluorometer (Twista prototype; ESE GmbH, Germany). Conditions used were 50 mM Tris/Acetate (pH 8.3), 14 mM Mg-Acetate, 100 mM Potassium-Acetate, 5 mM DTT, 240 nM each dNTP, 5% PEG 35,000, 4% Trehalose 2.5 mM ATP, 50 mM Phospho-Creatine, 300 ng/μL rb69gp32, 273 ng/μL uvsX, 120 ng/μL uvsY, 50 ng/μL Staph. aureus DNA polI. For the experiments of FIG. 5 , 1000, 100, 10 or 0 copies of the DNA template was included as indicated in the figure, while 1000 copies of the DNA template was included for the experiments of FIG. 6 . Fpg nuclease, 25 ng/μL, was included. Primers were included at 360 nM each and probe was included at 120 nM, with their sequences provided below. Fluorescence was measured every 20 seconds (excitation 470 nM, emission 520 nM). Samples were removed from the incubator for a brief mix/spin at 4 minutes of incubation time and returned to the incubator/fluorometer. Arbitrary fluorescence units were plotted against time in minutes.
For human genomic locus rs482-4871 the sequences of the primers, F2 and R1, and the probe used were:
(SEQ ID NO: 4)
F2
5′-ccatcctcaatactaagctaagtaaaaagattt-3′
(SEQ ID NO: 5)
R1
5′-ccctgtggctaagagctcttgatagtcaaagta-3′
(SEQ ID NO: 6)
Probe
BHQ1-5′-cctt[dR-FAM]tctaaggaaatggacag
aaataggcaagat[ddC]-3′
For human genomic locus rs1207445 the sequences of the primers, F2 and R2, and the probe used were:
(SEQ ID NO: 7)
F2
5′-cccttctgatattctaccaaatgccccctaaat-3′
(SEQ ID NO: 8)
R2
5′-catgtgtataagaaaactacccaagcctaggga-3′
(SEQ ID NO: 9)
Probe
BHQ1-5′-cagtg[dR-FAM]ccaatacacacacac
aagactgggcatgg[ddC]-3′
For human genomic locus rs1105561 the sequences of the primers, F1 and R1, and the probe used were:
(SEQ ID NO: 10)
F1
5′-tatagtggaaaggtgttcatttgtataaacccc-3′
(SEQ ID NO: 11)
R1
5′-cacataaatcagagaatgtgtggggtcatgtat-3′
(SEQ ID NO: 12)
Probe
BHQ1-5′-aactt[dR-FAM]gcaactaacgctaaa
ttataatcacttct[ddC]-3′
For human genomic locus rs5923931 the sequences of the primers, F1 and R1, and the probe used were:
(SEQ ID NO: 13)
F1
5′-catttctcaaaagaagatatgcaaataaaaaca-3′
(SEQ ID NO: 14)
R1
5′-ccattataactggggtgagatgatatctcattg-3′
(SEQ ID NO: 15)
Probe
BHQ1-5′-tctca[dR-FAM]cataactgatcatcag
agaaatgtaaatc[ddC]-3′
FIGS. 5 and 6 show the outcome of the above experiments in which RPA reactions were performed on human genomic targets utilizing primers and probes specifically directed toward known SNP regions. In FIG. 5 two such genomic regions were amplified using RPA and probes with the general structure depicted in FIG. 4 , along with the inclusion of the fpg protein. Target genomic DNA has been added to give a total target copy number of 1000, 100, 10 or zero target molecules, and in this way the requirement for the specific accumulation of amplicons matching the target is ensured. Note that after between 6 and 12 minutes (depending on the target and copy number) there is a clear rise in fluorescence in those samples containing target, whilst those lacking targets remain with more-or-less stable fluorescence. In FIG. 6 there is similar data shown for four human genomic DNA target/probe sets (two of which were also used in FIG. 5 ) and in each case fluorescence rises at about the expected time of DNA amplification. In addition to these and other successful probes, we have encountered occasional probes that did not seem to work well in RPA amplification/detection systems (maybe 10-20% of those analyzed) however the source of these failures is as yet unclear, potentially reflecting failures in RPA amplification in some cases rather than probe failure, potentially as a result of probe failure in other cases. We speculate that in some cases the position and nature of adjacent bases, or the nature of the base opposing the dR-O—[C]n group could play a part in the effectiveness of the probe.
Although particular embodiments have been disclosed herein in detail, this has been done by way of example for purposes of illustration only, and is not intended to be limiting with respect to the scope of the appended claims, which follow. In particular, it is contemplated by the inventors that various substitutions, alterations, and modifications may be made to the invention without departing from the spirit and scope of the invention as defined by the claims. Other aspects, advantages, and modifications considered to be within the scope of the following claims. The claims presented are representative of the inventions disclosed herein. Other, unclaimed inventions are also contemplated. Applicants reserve the right to pursue such inventions in later claims. | A new class of nucleic acid substrates for AP endonucleases and members of the glycosylase/lyase family of enzymes is described. Representatives of each family, the enzymes Nfo and fpg, respectively, cleave nucleic acid backbones at positions in which a base has been replaced by a linker to which a variety of label moieties may be attached. The use of these synthetic substrates embedded within oligonucleotides is of utility in a number of applications. | 2 |
This application claims the benefit of the filing date of the German Patent Application No. 10 2005 013 566.8 filed Mar. 23, 2005 and of the U.S. Provisional Patent Application No. 60/664,329 filed Mar. 23, 2005, the disclosures of which are hereby incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to an arrangement and a method for adapting the transportation behavior of material to be conveyed; to a means of locomotion; and to the use of an arrangement for adapting the transportation behavior of material to be conveyed in an aircraft.
TECHNOLOGICAL BACKGROUND
The term “vacuum systems” refers to special pneumatic conveyors. Generally speaking, in such conveyors transportation takes place in that a pressure difference is applied to the material to be conveyed, i.e. the material to be conveyed is entrained in the fluid flow generated as a result of the pressure difference, wherein generally air is used as the transport medium.
Especially in aircrafts, vacuum systems are used for the transportation of waste from the cabin, for example from toilets or galleys, to a central collecting tank. In this arrangement the material to be conveyed is conveyed to the collecting tank by way of a pipeline network. Negative pressure in the collecting tank in relation to the cabin pressure provides the required pressure difference.
In aircraft with pressurised cabins the pressure difference between the cabin and the environment is used directly to generate the negative pressure for pneumatic conveyance. When this pressure difference is insufficient, e.g. on the tarmac or at low altitudes, the required pressure difference is generated by a compressor.
In the case of toilets with a pneumatic conveyor system in aircraft systems, often a loud noise level arises. This noise is even noticed by the passengers in the cabin and is perceived by passengers to be uncomfortable.
Conventional measures to reduce the noise level at the feed-in location consist of closing the lid of the conveyance system prior to the flushing procedure so as to thereby keep the noise in check. Furthermore, attempts are made to instruct passengers by way of specific signage to take noise reduction measures such as for example to close the toilet lid. Up to now the kinetic energy of the material to be conveyed has been reduced at the inlet to the tank by means of tank inlet protection devices so as to prevent damage and wear.
However, up to now the above-described noise reduction measures have returned only moderate success, without effectively improving passenger comfort.
SUMMARY OF THE INVENTION
There may be a need to reduce noise generation in a pneumatic system for transporting a material to be conveyed.
According to an aspect of the invention there is provided an arrangement and a method for adapting the transportation behavior of material to be conveyed; a means of locomotion; and a use of an arrangement for adapting the transportation behavior of material to be conveyed in an aircraft according to the independent claims.
According to an exemplary embodiment of the invention an arrangement for adapting the transportation behavior of material to be conveyed is provided. The arrangement comprises at least one first container, which is coupleable to a first pressure level; at least a second container, which is coupleable to a second pressure level; and a connecting line for transporting material to be conveyed from the first container, of which there is at least one, to the second container, of which there is at least one. Furthermore, the arrangement comprises a pressure reduction device by means of which a pressure difference between the first container, of which there is at least one, and the second container, of which there is at least one, is controllably variable.
According to another exemplary embodiment of the invention a method for adapting the transportation behavior of material to be conveyed is created. In this method at least one first container is coupled to a first pressure level, at least one second container is coupled to a second pressure level, and material to be conveyed is transported from the first container, of which there is at least one, to the second container, of which there is at least one. Furthermore, a pressure reduction device for varying a pressure difference between the first container, of which there is at least one, and the second container, of which there is at least one, is controlled.
According to yet another exemplary embodiment of the invention a means of locomotion with an arrangement with the characteristics described above is created.
According to yet another exemplary embodiment of the invention an arrangement for adapting the transportation behavior of material to be conveyed, with the characteristics described above, is used in an aircraft.
According to an embodiment of the invention the noise level during a conveyance procedure can be reduced to such an extent that users (for example passengers of an aircraft) no longer perceive it negatively. With the arrangement and the method according to embodiments of the invention noise reduction, in particular as far as aircraft are concerned, is made possible by an economical and light-weight solution. Further, due to an adaptation of the pressure differences and accordingly of the transportation velocity, because of a deceleration of the fluid there occur less damages caused by the kinetic energy of the material to be conveyed. Keeping aircraft weight to a minimum is a very special objective.
In that according to one embodiment of the invention a pressure reduction device is provided in a pneumatic conveyance system, by means of which pressure reduction device a pressure difference between two containers can be controlled in a targeted way and can in particular be reduced, the transport characteristics can be influenced in a defined manner, in particular the transport speed can be attenuated, as a result of which noise generation is also reduced to a surprising degree.
The speed of the air at the feed-in location, which air entrains the material to be conveyed, largely depends on the position of the receiving tank in the pipe system and on the pressure in the collecting tank. At the same time this air speed determines the noise that is generated. By means of the reduction in the pressure difference noise development that arises can effectively be reduced.
The large pressure difference between the interior cabin pressure and the exterior ambient pressure at cruising altitude, which pressure difference in conventional systems can result in the fluid attaining enormous speeds, can be reduced in a targeted way such that the noise development at the feed-in location is significantly reduced.
Due to the reduction of the fluid velocity damages in particular at the container walls of the receiving container may be avoided effectively, because the material to be conveyed impinges at the container walls with an accordingly reduced kinetic energy.
It can be achieved that the generated noise level at the feed-in position and the kinetic energy of the material to be conveyed is reduced by influencing and adapting pressure differences in a conveyance system.
In a further exemplary embodiment the pressure reduction device comprises at least one ventilation unit between the first container and the second pressure level. This makes it possible to hold a pressure difference constant or to compensate any excessive pressure difference in that the pressure in the second container is increased. This ventilation unit can optionally be designed so as to be regulable or non-regulated. Furthermore, the ventilation device can comprise noise reduction devices, in particular sound absorbers, so as in this way to reduce the inflow noise from the cabin. In an exemplary embodiment a ventilation unit can be installed between the second container and the second pressure level and can be controlled in such a way that the material to be conveyed can flow from the second pressure level back to the second container.
In a further exemplary embodiment the pressure reduction device comprises at least one throttle element between the first container and the second pressure level, wherein the throttle element can be designed so as to be either regulable or non-regulated. The throttle element can regulate, i.e. reduce, the fluid speed, and can be installed either between a ventilation unit and the second pressure level in order to reduce the inflow speed at that location. Alternatively, it can be located between the second container and the second pressure level in order to reduce the speed at which the fluid flows out into the surroundings.
In a further exemplary embodiment the arrangement comprises a compressor element between the second pressure level and the second container in order to generate negative pressure in the second container, so that in the case of a high second pressure level there is nonetheless a pressure difference between the first container and the second container is provided, in that for example the pressure in the second container is reduced. Parallel to the compressor element there is the additional option of installing a regulable or non-regulated throttle element in a parallel branch so as not to influence the operation of the compressor as a result of the reduction, in other words without causing a throttling effect.
In a further exemplary embodiment a nonreturn valve or a check valve is attached in the connecting line between the second pressure level and the second container so as to prevent the fluid from flowing in from the second pressure level to the second container. The nonreturn valve can also be installed parallel to the compressor, and furthermore it can comprise an integrated throttle device.
In a further exemplary embodiment a separator is installed between the second container and the pressure level for separating the material to be conveyed from a fluid.
In a further exemplary embodiment the first container is connected to the connecting line by means of an actuating valve, wherein after actuation of the actuating valve transport of the goods to be conveyed can be started or stopped.
In a further exemplary embodiment noise reduction devices are provided, in particular are installed on the first container.
In a further exemplary embodiment an inlet protection device is affixed in the second container in order to reduce the kinetic energy of the material to be conveyed when said material enters the second container.
In a further exemplary embodiment the pressure reduction device comprises at least one component with integrated throttle and ventilation function between the second pressure level and the second container.
According to an exemplary embodiment of the invention, in an emergency the ventilation devices are closed essentially without any auxiliary energy, and/or the throttle elements are opened essentially without any auxiliary energy.
According to a further exemplary embodiment of the method, for the purpose of controlling the ventilation device and/or the throttle element the pressure difference between the first container and the second container is used as a command variable. In a further exemplary embodiment of the method, the command variable for controlling the ventilation unit and/or for controlling the throttle element can be set depending on the position of the first containers and/or of the second containers.
According to a further exemplary embodiment of the method the compressor element and the ventilation device can vary and set the pressure in a manner offset in time before and after conveying the material to be conveyed.
According to an exemplary embodiment of the method, for the purpose of controlling and regulating the ventilation device and/or the throttle elements, sensor data such as for example cabin pressure, ambient pressure, pressure and fill level of the second container, flight altitude or temperature can be used. This data also makes it possible to diagnose the vacuum system. For example by means of a flushing procedure that only involves air, and by measuring the resulting tank-pressure gradient, a comparison of the desired values with actual values for pressure losses can take place and in this way any malfunctions can be detected reliably and early.
The designs of the arrangement also apply to the method and to the means of locomotion as well as or their use, and vice versa.
The described arrangement and the described method provide effective noise reduction of transported material to be conveyed, so that the comfort, for example of passengers, is enhanced enormously. The kinetic energy can be optimally set with a controllable pressure ratio, as a result of which optimal setting, damage and noise are prevented or reduced. Furthermore, this arrangement is extremely light in weight and economical to implement.
The means of locomotion according to the invention can for example be an aircraft, a rail carriage, a truck, a passenger motor vehicle, a caravan, a boat or ship, or a zeppelin.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, for further explanation and to provide a better understanding of the present invention, several embodiments of the invention are described in more detail with reference to the drawings, as follows:
FIG. 1 a diagrammatic view of a vacuum system according to an exemplary embodiment of the invention;
FIG. 2 a diagrammatic view of a vacuum system according to another exemplary embodiment of the invention with variants for regulating the through-flow speed;
FIG. 3 a diagram showing the influence which ventilation and throttling have on the speed of transportation and on the noise level at the feed-in location, depending on the magnitude of the air volume in the tank.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Identical or similar components in different figures have the same reference characters.
The illustrations in the figures are diagrammatic and not to scale.
FIG. 1 shows an arrangement of a vacuum system for aircraft with a pressurised cabin.
In each case first containers 3 to accommodate a material 2 to be conveyed are connected by means of an actuating valve 4 to a connecting line 5 leading to a central second container 7 . Noise reduction devices 31 are installed on each of first containers 3 . At the inlet to the second container 7 there is a special tank inlet protection device 6 , which among other thing's is designed to reduce the kinetic energy of the material 2 to be conveyed, so as to protect the second container 7 . By means of a further connecting line 11 the collecting tank 7 is connected, by way of a separator 10 which includes a tank return and by way of a compressor element 12 , to the second pressure level 14 , here the environment outside the aircraft. Parallel to the compressor element 12 a return valve 13 is arranged.
If the pressure difference between the first pressure level 1 (ambient pressure at the feed-in location 3 , for example cabin pressure) and the second pressure level, i.e. between the cabin 1 and the environment 14 , is inadequate, the system is operated with the compressor element 12 (operating mode I). In this way the compressor 12 starts at the latest when a flushing procedure is requested. During the time interval of a few seconds until the opening of the actuating valve 4 , negative pressure is already generated in the second container 7 . Thus, as soon as the flush valve 4 is opened, conveyance to the tank, of the material 2 to be conveyed, commences. The compressor element 12 continues to run at least until the actuating valve 4 is closed again, thus maintaining negative pressure in the tank 7 for continuous conveyance. The separator 10 prevents any material 2 to be conveyed from escaping from the collecting container 7 , and protects the compressor 12 and the environment 14 from contamination. The nonreturn valve 13 remains closed in this operating mode.
In an alternative operating mode II with sufficient pressure difference between the cabin 1 and the environment 14 the compressor element 12 remains switched off. When the actuating valves 4 are closed, the tank 7 is subjected to the same low pressure as in the environment 14 outside the aircraft. If the flush valve 4 is open, negative pressure in the tank 7 is maintained in that the air flows out by way of the nonreturn valve 13 .
Up to now the compressor elements 12 have mostly been designed so as to provide just adequate conveyance behavior when the aircraft is on the ground. The nonreturn valve can already fully open at a small pressure difference, and the airflow through it can take place with minimum loss of pressure. Downstream of the separator 10 a non-regulated throttle device 15 a is provided for easy adaptation of the conveyance behavior. However, generally speaking, this throttling position cannot be considered optimal for all forms of application because part of the expensively generated pressure difference is degraded during compressor operation 12 .
In FIG. 2 a further arrangement for reducing noise at the feed-in locations of the material 2 to be conveyed has been provided by limiting the driving pressure difference to an extent necessary for the flushing procedure, preferably in operating mode II.
For reliable operation, this design point should be above the behavior with compressor operation. This still leaves sufficient potential to reduce noise at cruising altitude, at which normally the maximum pressure difference occurs. This applies in particular since in most cases this state represents the main share of the time vacuum systems in aircraft are used.
Essentially the air volume 9 in the collecting tank 7 causes a non-stationary pressure gradient in the second container 7 during the flushing procedure. Thus, most of the time, the pressure in the collecting tank 7 increases until the stationary state has been reached. This increase in pressure is determined by the flow losses from 9 to 14 in the stationary case. The pressure difference between the cabin 1 and the collecting tank 7 induces a corresponding time gradient of the air entry speed, and thus of the generated noise level at the first container 3 .
In order to limit noise emission, an essentially constant pressure difference from 1 to 7 has to be ensured. Generally speaking an additional ventilation valve 16 a - 16 d according to FIG. 2 can handle this task before, during and after the flushing procedure. However, this can be associated with high speeds or high volume flows between the connecting lines 5 or 11 or the tank 7 and the ventilation valve 16 a - 16 d . This can be compensated for by using a further regulable throttle valve 17 a or 17 b downstream of the ventilation valve 16 a - 16 d . If a throttle valve 15 , 17 is used on its own, its influence is however limited to the duration of the flushing process.
The greater the air volume 9 in the tank, the stronger the effect the initial tank pressure has on the flushing process. In this case a stationary state only occurs after a relatively long opening time of the flush valve 4 (compare FIG. 3 ). Thus in this case ventilation assumes decisive importance.
In such a cases where a small second container 7 is used, the air volume 9 is small. It may thus be possible to abandon a ventilation valve 16 a - 16 d . In the case of a small number of connected receiving containers 3 , which are installed at similar distances from the tank 7 , it is also possible to provide a non-regulated throttling element, for example at position 15 b . At this position, compressor operation 12 is not affected by the reduction. Reduced conveyance performance at low flight altitudes, i.e. at small pressure differences, without compressor operation 12 can also be compensated for by extending compressor operation if need be. Moreover, the use of the system in this boundary region does not represent a typical application case.
In principle the actuating valve 16 can be installed at positions 16 a - 16 d . Immediately after a request of a flushing procedure said actuating valve 16 sets the required tank pressure until the flush valve 4 is opened. This procedure can be interpreted as a counterpart to the evacuation phase during compressor operation 12 . Subsequently, for example, the throttle valve keeps the tank pressure constant at position 17 a or 17 b during the flushing procedure.
Since the loss of pressure 1 - 9 depends on the length and the gradient of the connecting line 5 , the pressure difference to be set should be implemented depending on the position of the first container 3 . In this way the often very different transportation behavior of receiving containers 3 with different distances from the collecting tank 7 can be made to be uniform.
In the case of malfunction a ventilation valve 16 should assume a fully closed state, while a regulable throttle valve 17 should assume a fully open state, both without any auxiliary energy. In this way the system remains functional.
Also of interest is the combination of ventilation function and throttle function at positions 16 d and 17 a to a component.
As far as regulation is concerned, access to data that is already available in the aircraft system presents itself; such data being for example cabin pressure, ambient pressure and tank fill level (to determine the air volume in the tank). Furthermore, fill level determination based on two absolute pressure sensors directly provides information on the pressure in the tank 7 . As shown in FIG. 2 , a sensor 32 is positioned in line between first container 3 and second container 7 . A monitoring device 33 is coupled to sensor 32 . The sensor 32 and monitoring device 33 may also or alternatively be positioned in the tank 7 . The use of additional sensors can thus be minimised by suitable system linkages.
From the regulating deviations for a flushing procedure that only involves air, it is furthermore possible to obtain information concerning possible blockages in the regions 1 - 9 and 9 - 14 . This diagnostic function can also be transferred to conventional vacuum systems.
In addition it should be pointed out that “comprising” does not exclude other elements or steps, and “a” or “one” does not exclude a plural number. Furthermore, it should be pointed out that characteristics or steps, which have been described with reference to one of the above embodiments can also be used in combination with other characteristics or steps of other embodiments described above.
It should also be noted that reference signs in the claims shall not be construed as limiting the scope of the claims. | The present invention relates to an arrangement for adapting the transportation behavior of material to be conveyed, which arrangement comprises a first container, which is coupleable to a first pressure level; a second container, which is coupleable to a second pressure level; a connecting line for transporting material to be conveyed from the first container to the second container; and a pressure reduction device by means of which a pressure difference between the first container and the second container is controllably variable. | 1 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to a windshield wiper device for a vehicle, in particular a motor vehicle.
[0002] Windshield wiper devices typically have a wiper arm or wiper lever, wherein a wiper blade is moved over the windshield of a motor vehicle. The wiper blade is moved here between a first turning position and a second turning position. For this purpose, the wiper arm is connected via a driveshaft to a wiper motor. In particular in the case of windshields having pronounced changes in curvature, the wiper blade easily loses contact with the windshield. In particular in the case of windshields with a pronounced curvature, this may result in wiping areas not being wiped, or in smearing.
[0003] Since a wiping operation has to be optimized for a multiplicity of parameters, such as, for example, the amount of rain falling on the windshield, a possible snow loading on the windshield, the speed of the vehicle and associated wind pressure on the wiper arm, smearing cannot be reliably prevented in a simple manner by adaptation of the pressure of the wiper arm on the windshield. There is therefore a need for further improvement of windshield wiper devices.
[0004] A plurality of boundary conditions should additionally be taken into consideration for improvement purposes. These include the outlay on the production, and the production costs, the material costs, but also the properties of the windshield wiper device, in particular the function under diverse conditions and the endurance under a multiplicity of conditions.
[0005] Customarily, the regular use of windshield wiper devices, in particular wiper blades, causes the occurrence of wear phenomena, which are associated with a deterioration in the wiping quality. Furthermore, the exposed position of windshield wiper devices on the front windshield or rear windshield of motor vehicles, in particular during passage through a washing system, gives rise to the risk of the windshield wiper device being damaged or even torn off. In these cases, the worn or damaged windshield wiper devices have to be exchanged. Conventionally, the exchange of windshield wiper devices is relatively complicated since the latter are customarily fastened to the driveshaft via screw connections.
SUMMARY OF THE INVENTION
[0006] It is the object of the present invention to provide a windshield wiper device with which at least one or more of the abovementioned disadvantages are reduced or substantially do not occur.
[0007] According to an aspect of the present invention, a windshield wiper device for a vehicle with a fastening element, in particular a motor vehicle, is proposed. The windshield wiper device comprises a wiper blade with an elongate upper part and an elongate lower part, which are configured to be at least partially bendable. Furthermore, a plurality of connecting elements for connecting the upper part and the lower part are provided, wherein the connecting elements are spaced apart from one another along a longitudinal extent of the wiper blade. The connecting elements are designed in order to permit a movement of the upper part and of the lower part relative to each other with a movement component along a longitudinal extent of the wiper blade. Furthermore, the wiper blade comprises a wiper-blade-side fastening part. The wiper-blade-side fastening part has a securing element into which the fastening element can be inserted and which is designed in order to form a non-positively locking connection and/or positively locking connection with the fastening element.
[0008] According to a further aspect of the present invention, a method for mounting a windshield wiper device is provided. The method comprises providing a windshield wiper device according to the embodiments described herein. Furthermore, the method comprises fastening the wiper-blade-side fastening part to the fastening element by forming the non-positively locking connection and/or positively locking connection between the securing element and the fastening element.
[0009] Preferred embodiments and particular aspects of the invention emerge from the dependent claims, the drawings and the description here.
[0010] According to the windshield wiper device described herein in accordance with embodiments described herein and by the method for mounting the windshield wiper device, a windshield wiper device which can be mounted and dismounted in a simple manner is provided. The windshield wiper device, which is preferably of the fin-ray type, is mounted onto a fastening element, which may be a drive spindle for the wiper, and dismounted therefrom with a single movement (“one click”). Accordingly, in the event of damage, the windshield wiper device can be exchanged in a simple manner or removed in a simple manner before passage through a washing system and subsequently mounted again.
[0011] According to embodiments of the disclosure that may be combined with other embodiments described herein, the securing element has an opening into which the fastening element can be inserted. Therefore, the wiper blade can be fastened on the mounting element by a single movement, namely the insertion of the securing element into the opening for a non-positively locking connection and/or positively locking connection.
[0012] According to embodiments of the disclosure that may be combined with other embodiments described herein, the size of the opening is variable. The windshield wiper device can therefore be used in combination with different types of fastening elements.
[0013] According to embodiments of the disclosure that may be combined with other embodiments described herein, circumferential regions of the opening are designed in order to form the non-positively locking connection and/or positively locking connection with the fastening element. A non-positively locking connection and/or positively locking connection between the securing element and the fastening element can therefore be produced and released again in a simple manner, for example by the size of the opening being changed.
[0014] According to embodiments of the disclosure that may be combined with other embodiments described herein, the wiper-blade-side fastening part has an actuating device which is designed in order to release the non-positively locking connection and/or positively locking connection. The wiper blade can therefore be dismounted in a simple manner.
[0015] According to embodiments of the disclosure that may be combined with other embodiments described herein, the actuating device is designed in order to change the size of the opening upon an actuation. The wiper blade can therefore be mounted and dismounted in a simple manner.
[0016] According to embodiments of the disclosure that may be combined with other embodiments described herein, the securing element is of U-shaped design. The windshield wiper device can therefore be produced simply and cost-effectively.
[0017] According to embodiments of the disclosure that may be combined with other embodiments described herein, the actuating device is insertable between two open ends of the U-shaped securing element. The non-positively locking connection and/or positively locking connection can therefore be released in a simple manner.
[0018] According to embodiments of the disclosure that may be combined with other embodiments described herein, the securing element comprises a retaining spring. The windshield wiper device can therefore be produced simply and cost-effectively.
[0019] According to embodiments of the disclosure that may be combined with other embodiments described herein, the securing element is designed in order to engage in a depression of the fastening element in order to form the non-positively locking connection and/or positively locking connection. A windshield wiper device with which a position of the wiper-blade-side fastening part can be secured in a stable manner relative to the mounting element is therefore provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Exemplary embodiments of the invention are illustrated in the figures and are described in more detail below. In the figures:
[0021] FIG. 1 shows a schematic illustration of a windshield wiper device according to embodiments of the disclosure in an unfastened state,
[0022] FIG. 2 shows a schematic illustration of the windshield wiper device of FIG. 1 according to embodiments of the disclosure in a fastened state,
[0023] FIG. 3 shows a perspective view of the fastening element according to embodiments of the disclosure,
[0024] FIGS. 4A and 4B show perspective views of a securing element according to embodiments of the disclosure,
[0025] FIG. 5 shows a schematic illustration of the windshield wiper device mounted on the fastening element according to embodiments of the disclosure,
[0026] FIG. 6 shows a schematic illustration of a further exemplary embodiment of a windshield wiper device according to the invention in the form of a wiper arm with integrated wiper blade in a basic position,
[0027] FIG. 7 shows a schematic illustration of the wiper arm with integrated wiper blade according to FIG. 6 in a position placed against a windshield, and
[0028] FIG. 8 shows a sequence diagram for illustrating embodiments of the method for mounting a windshield wiper device according to embodiments of the disclosure.
DETAILED DESCRIPTION
[0029] The same reference signs are used below for identical elements and elements of identical function, unless stated otherwise.
[0030] A windshield wiper device 100 according to embodiments of the disclosure is illustrated schematically in FIGS. 1 and 2 . FIG. 1 shows the windshield wiper device 100 in an unfastened state, and FIG. 2 shows the windshield wiper device 100 of FIG. 1 in a fastened state.
[0031] According to embodiments of the disclosure, the windshield wiper device 100 comprises a fin-ray structure and a wiper-blade-side fastening part 20 with a securing element.
[0032] According to embodiments of the disclosure, the windshield wiper device 100 comprises a wiper blade 2 with an elongate upper part 10 and an elongate lower part 12 , which are configured to be at least partially bendable. Furthermore, a plurality of connecting elements 18 for connecting the upper part 10 and the lower part 12 are provided, wherein the connecting elements 18 are spaced apart from one another along a longitudinal extent 8 of the windshield wiper device 100 . The connecting elements 18 are designed in order to permit a movement of the upper part 10 and of the lower part 12 relative to each other with a movement component along a longitudinal extent 8 of the windshield wiper device 100 .
[0033] According to embodiments of the disclosure that may be combined with other embodiments, the wiper blade 2 has a wiper-blade-side fastening part 20 . The wiper-blade-side fastening part 20 has a securing element into which the fastening element 50 of the vehicle can be inserted. The securing element is designed in order to form a non-positively locking connection and/or positively locking connection with the fastening element 50 .
[0034] According to embodiments of the disclosure that may be combined with other embodiments, a “non-positively locking connection” is understood as meaning all connections which arise through the transmission of forces (for example non-positive connections, frictional connection). In particular, such connections use compressive forces and/or frictional forces. These connections are held together by the acting force.
[0035] According to embodiments of the disclosure that may be combined with other embodiments, a “positively locking connection” is understood as meaning all connections which arise by intermeshing of at least two elements (positive connections). In particular, by means of the mechanical connection, the elements also cannot be released without force transmission or if the force transmission is interrupted.
[0036] As is illustrated by way of example in FIGS. 1 and 2 , the wiper-blade-side fastening part 20 according to embodiments of the windshield wiper device 100 that may be combined with other embodiments can be connected to a fastening element 50 or can be fastened thereto. For this purpose, the fastening element 50 is inserted into the securing element of the wiper-blade-side fastening element 50 , as indicated by the arrow 5 in FIG. 1 . According to typical embodiments, the securing element is present in the wiper-blade-side fastening element 50 or is integrated therein.
[0037] The securing element forms a non-positively locking connection and/or positively locking connection with the fastening element 50 in order to fixedly connect the wiper-blade-side fastening part 20 to the fastening element 50 on the vehicle. A windshield wiper device 100 with which a position of the wiper-blade-side fastening part 20 can be secured in a stable manner relative to the fastening element 50 is therefore provided.
[0038] According to embodiments of the disclosure that may be combined with other embodiments, the securing element has an opening into which the fastening element 50 can be inserted. According to typical embodiments, the size of the opening is variable or can be varied. For example, the size of the opening can be varied by an actuating device 21 (“release button”). According to embodiments of the disclosure, circumferential regions of the opening are designed in order to form the non-positively locking connection and/or positively locking connection with the fastening element 50 . A non-positively locking connection and/or positively locking connection between the securing element and the fastening element 50 can therefore be produced and released again in a simple manner, for example by the size of the opening being changed.
[0039] According to embodiments of the disclosure that may be combined with other embodiments, the wiper-blade-side fastening part 20 furthermore has the actuating device 21 which is designed in order to release the non-positively locking connection and/or positively locking connection. According to typical embodiments, the actuating device 21 has a key button or a pushbutton. A user, by pressing the actuating device 21 , can thus release the non-positively locking connection and/or positively locking connection in order to dismount the windshield wiper device 100 and remove same from the fastening part 50 . Accordingly, the windshield wiper device 100 can easily be exchanged in the event of damage or removed before passage through a washing system and subsequently mounted again in a simple manner.
[0040] According to some embodiments, a pushbutton can be provided as actuating device 21 on one side, for example, as illustrated in FIG. 1 , on the rear side or else on the upper side of the windshield wiper device, i.e. on the side facing away from the windshield. According to another alternative, two pushbuttons can also be provided as actuating device 21 , for example on both sides of the fastening part 20 .
[0041] According to embodiments of the disclosure that may be combined with other embodiments, the actuating device 21 is furthermore designed in order to permit mounting of the windshield wiper device 100 on the fastening element 50 . For example, by actuation of the actuating device 21 , the securing element can be opened or released such that the fastening element 50 can be inserted. In particular, the insertion can take place during actuation of the actuating device 21 . After the insertion, the actuation of the actuating device 21 can be ended or released (for example by letting go of the key button or pushbutton), as a result of which the non-positively locking connection and/or positively locking connection is produced. Accordingly, the windshield wiper device 100 can easily be exchanged in the event of damage or can be removed before passage through a washing system and subsequently mounted again in a simple manner.
[0042] FIG. 3 shows a perspective view of the fastening element 50 on the vehicle according to embodiments of the disclosure.
[0043] According to embodiments of the disclosure that may be combined with other embodiments, the fastening element 50 is designed as a drive spindle or driveshaft for the windshield wiper device 100 .
[0044] As is shown by way of example in FIG. 3 , the fastening element 50 has a depression or an indentation 51 . According to typical embodiments, the securing element of the windshield wiper device 100 is designed in order to engage in the depression or indentation 51 of the fastening element in order to form the non-positively locking connection and/or positively locking connection.
[0045] The illustrative fastening element 50 shown in FIG. 3 furthermore has a conical region 52 . According to typical embodiments, the conical region is formed above the depression 51 in order to facilitate insertion of the fastening element into the securing element of the windshield wiper device 100 .
[0046] According to embodiments of the disclosure that may be combined with other embodiments, the fastening element 50 is designed as an intersection for transmitting torque to the wiper arm (reference sign 53 ), for the axial securing by the retaining spring (depression 51 ), and/or for the axial guidance with the wiper arm (reference sign 54 ).
[0047] According to embodiments of the disclosure that may be combined with other embodiments, the securing element 22 , for example the retaining spring, is fitted or cast fixedly into the wiper blade or into the wiper-blade-side fastening part 20 . The wiper is pushed axially onto the bearing shaft. According to typical embodiments, a translatory movement therefore takes place for the fastening. For example, during the pushing onto the spindle, the spring gives way and latches into the depression (intersection) 51 . The transmission of torque is ensured by the intersection 53 . According to typical embodiments, the intersection 54 restricts a radial freedom of movement/a radial play.
[0048] FIGS. 4A and 4B show perspective views of a securing element 22 according to embodiments of the disclosure.
[0049] According to embodiments of the disclosure that may be combined with other embodiments, the securing element 22 has the opening 23 into which the fastening element 50 can be inserted. According to typical embodiments, the size of the opening 23 is variable or can be varied.
[0050] The illustrative securing element 22 shown in FIG. 4A is of U-shaped design. The U shaped securing element 22 here has a closed end 24 and two open ends 25 . In a region between the closed end 24 and the open ends 25 , a distance between the two limbs of the U shape changes such that the opening 23 is formed. According to typical embodiments, the opening 23 is of circular or oval design. In particular, the two limbs of the U shaped securing element 22 are shaped in such a manner that the opening 23 is of circular or oval design.
[0051] According to embodiments of the disclosure that may be combined with other embodiments, the actuating device 21 can be inserted between the two open ends of the U shaped securing element 22 , as is shown by way of example in FIG. 4B . According to typical embodiments, the open ends 25 can be of funnel-shaped design in order to permit insertion or engagement of the actuating device 21 .
[0052] As is shown by way of example in FIG. 4B , the U shape of the securing element 22 can be widened by the actuating device 21 , and therefore the size of the opening 23 can be varied. In particular, the opening can be widened by the actuating device 21 in order to insert the fastening element 50 into the opening 23 . According to typical embodiments, after the insertion, the actuation can be released again in order to produce the non-positively locking connection and/or positively locking connection between the securing element 22 and the fastening element 50 .
[0053] According to embodiments of the disclosure that may be combined with other embodiments, the securing element 22 is designed as a retaining spring. The securing element 22 can therefore be produced in a simple and cost-effective manner.
[0054] As is shown in FIG. 3 , the fastening element 50 can have a depression or an indentation 51 . According to typical embodiments, the securing element 22 is designed in order to engage in the depression 51 of the fastening element 50 in order to form the non-positively locking connection and/or positively locking connection. With reference to FIGS. 4A and 4B , circumferential regions of the opening 23 can be designed in order to form the non-positively locking connection and/or positively locking connection with the fastening element 50 . Typically, the circumferential regions of the opening 23 are designed in order to engage in the depression 51 of the fastening element 50 in order to form the non-positively locking connection and/or positively locking connection. A non-positively locking connection and/or positively locking connection between the securing element 22 and the fastening element 50 can therefore be produced and released again in a simple manner, for example by the size of the opening 23 being changed.
[0055] According to typical embodiments, a diameter of the opening 23 in the non-mounted state of the windshield wiper device 100 can be smaller than a maximum diameter of the conical region 52 (lower end of the conical region 52 in FIG. 3 ) of the fastening element 50 , and can be larger than a minimum diameter of the conical region 52 (upper end of the conical region 52 in FIG. 3 ).
[0056] According to typical embodiments, during the mounting of the windshield wiper device 100 the conical region 52 of the fastening element 50 can thus be inserted into the opening 23 , as a result of which the opening is widened as the insertion progresses. When the lower end of the conical region 52 is reached, the circumferential regions of the opening move by the restoring (spring) force provided by the U shape into the depression 51 or engage in the latter such that the securing element 22 forms in particular a positively locking connection with the fastening element 50 . The restoring spring force of the securing element 22 can furthermore provide a non-positively locking connection. A non-positively locking connection and/or positively locking connection between the securing element 22 and the fastening element 50 can therefore be produced in a simple manner.
[0057] According to embodiments of the disclosure that may be combined with other embodiments, the securing element 22 , for example the retaining spring, is fitted or cast fixedly into the wiper blade or the wiper-blade-side fastening part 20 . The wiper is pushed axially onto the bearing shaft, with the spring giving way and latching into the depression (intersection) 15 . The transmission of torque is ensured by the intersection 53 (see FIG. 3 ). According to typical embodiments, the intersection 54 restricts a radial freedom of movement/a radial play.
[0058] FIG. 5 shows a schematic illustration of the windshield wiper device 100 mounted on the fastening element 50 according to embodiments of the disclosure.
[0059] As is shown in FIG. 5 , the wiper-blade-side fastening part 20 is placed onto the fastening element 50 which may be a driveshaft. The securing element 22 engages in the depression of the fastening element 50 in order to produce at least a positively locking connection with the fastening element 50 . The actuating device 50 is provided on the wiper-blade-side fastening part 20 in order to release the non-positively locking connection and/or positively locking connection of the securing element 22 with the fastening element 50 .
[0060] The embodiments described herein thus provide a windshield wiper device which can be mounted and dismounted in a simple manner. Accordingly, the windshield wiper device can easily be exchanged in the event of damage or removed before passage through a washing system and subsequently mounted again in a simple manner.
[0061] Illustrative embodiments of wiper systems for which the windshield wiper device described herein can be advantageously used are described below. In principle, however, the fastening device described herein may also be used for other windshield wiper devices.
[0062] FIGS. 6 and 7 show schematic illustrations of a wiper blade 2 in a basic position ( FIG. 6 ) and in a position placed against a windshield 4 ( FIG. 7 ) according to embodiments of the windshield wiper device 100 of the disclosure. The wiper blade 2 serves for wiping a windshield 4 of a vehicle, which is, for example, a motor vehicle, in particular a car. The wiper blade 2 is customarily attached to a windshield wiper arm which is driven for wiping purposes by means of a motor. For this purpose, the wiper blade 2 has a holder at which it can be fastened to the windshield wiper arm. In FIG. 6 , the wiper blade 2 is in a basic position in which it is at least partially lifted off the windshield 4 . The wiper blade 2 has a longitudinal extent 8 and has an elongate upper part 10 and a likewise elongate lower part 12 . The longitudinal extents of the upper part 10 and of the lower part 12 substantially correspond to the longitudinal extent 8 of the wiper blade 2 .
[0063] Both the upper part 10 and the lower part 12 are bendable beams or may be configured as bendable beams which, in FIGS. 6 and 7 , are for example in each case formed in one piece. This makes it possible to realize a particularly stable construction. It is likewise possible for in each case only one part of the upper part 10 and/or the lower part 12 to be configured to be bendable. Furthermore, it is alternatively possible for the upper part 10 to be configured in multiple parts.
[0064] According to some embodiments that may be combined with the other embodiments described here, a material that has a modulus of elasticity in a range between 0.005 kN/mm 2 and 0.5 kN/mm 2 , in particular 0.01 kN/mm 2 and 0.1 kN/mm 2 , is used for the upper part 10 and/or the lower part 12 . This makes it possible to realize suitable bendability of the upper part 10 and of the lower part 12 . Together with a suitably configured cross-sectional area of the upper part 10 and of the lower part 12 , optimum flexural rigidity is thus attained. The upper part 10 and the lower part 12 are arranged so as to be situated opposite each other. One end of the upper part 10 is fixedly connected at an outer connecting position 34 to one end of the lower part 12 . The upper part 10 and the lower part 12 are otherwise spaced apart from each other.
[0065] The upper part 10 and the lower part 12 are connected to each other by connecting elements 18 . In particular in the basic position of the wiper blade 2 , said connecting elements run approximately transversely with respect to the longitudinal extent 8 of the wiper blade 2 . The connecting elements 18 are fastened by means of rotary joints 19 to mutually facing inner longitudinal sides of the upper part 10 and of the lower part 12 . The rotary joints 19 are hinges here. In particular, the rotary joints 19 may be in the form of film hinges. This is advantageous in particular if upper part 10 , lower part 12 and/or connecting elements 18 are produced from a plastics material or are coated with a suitable plastics material.
[0066] According to typical embodiments described here that may be combined with other embodiments described here, a rotary joint is selected from the group consisting of: a hinge, a film hinge, a narrowing of the material for the purpose of generating reduced rigidity along a torsional axis, a joint with an axis of rotation, a means for connecting the upper part to the connecting element or for connecting the lower part to the connecting element, which means permits the displacement of the lower part in relation to the upper part along the longitudinal extent, etc.
[0067] Embodiments in which the joint is provided by a film hinge thus constitute a very simple means for providing the joints for a fin-ray wiper. The wiper blade 2 may be provided in one piece, in particular in ready-from-the-mold form. According to typical embodiments, the windshield wiper device, in particular the wiper blade, is produced from one or more materials from a group consisting of: TPE (thermoplastic elastomer), for example TPE S, TPE O, TPE U, TPE A, TPE V and TPE E. The film hinges can exhibit high ductility. This may be realized for example by means of a material selected from the group PP, PE, POM and PA. Alternatively, the film hinges may be produced from one or more materials from a group consisting of: TPE (thermoplastic elastomer), for example TPE S, TPE O, TPE U, TPE A, TPE V and TPE E.
[0068] The connecting elements 18 are spaced apart from one another along the longitudinal extent of the wiper blade 2 . The spacings between two respective adjacent connecting elements 18 are uniform. Said spacings may, however, also be selected so as to differ. The spacings are advantageously less than 50 mm, in particular less than 30 mm. In this way, it is possible to ensure particularly great flexibility of the windshield wiper device, in particular of its lower part, and good adaptation to the curvature and changes in curvature of the windshield to be wiped.
[0069] In particular in the basic position of the wiper blade 2 , the connecting elements 18 are fastened to the lower part 12 such that the longitudinal axes of said connecting elements run at angles 26 of between 65° and 115°, in particular between 75° and 105°, with respect to the lower part 12 . The angles particularly advantageously lie between 80° and 100°. This advantageously ensures particularly good transmission of a force, which acts on the lower part, to the upper part. Furthermore, a particularly stable windshield wiper device can be realized in this manner. Corresponding statements apply to the points at which the connecting elements 18 are fastened to the upper part 10 .
[0070] The spacings between the upper part 10 and the lower part 12 are defined primarily by the lengths of the connecting elements 18 . The lengths of the connecting elements 18 increase from the outer connecting position as far as approximately the locations at which the wiper-blade-side fastening part 20 begins. In this way, in the side view of the wiper blade 2 as per FIG. 6 , the upper part 10 and the lower part 12 form a wedge. The connecting elements 18 are designed to be resistant to buckling.
[0071] FIG. 7 shows a schematic illustration of the wiper blade 2 as per FIG. 6 in a position in which said wiper blade is placed against the windshield 4 . Since the windshield 4 has a curvature, contact pressure forces are exerted on the lower part 12 when the wiper blade 2 is placed against the windshield 4 . Since the upper part 10 and the lower part 12 are bendable beams and the connecting elements 12 are mounted rotatably on upper part 10 and lower part 12 , the upper part 10 and the lower part 12 are displaceable relative to each other. Owing to the compressive forces acting on the lower part 12 from below, the wiper blade 2 bends in the direction from which the compressive forces originate, and is placed precisely against the curvature of the windshield 4 .
[0072] Owing to the construction of the embodiments described here, when a force is exerted on the lower part (by the windshield 4 ), the lower part bends in the direction from which the force acts. This is the case owing to the connection of the upper part 10 and of the lower part at connecting positions 14 and/or 16 , the shape, and owing to rotary joints at the connection between the connecting elements and the upper and lower parts respectively.
[0073] In the illustration as per FIG. 7 , there is a small spacing between the wiper blade 2 and the windshield 4 , which small spacing serves here merely for the illustration of the windshield 4 and of the wiper blade 2 and, in reality, is substantially not present when the wiper blade 2 is placed against the windshield 4 . Furthermore, a wiper lip which is placed onto the windshield 4 for wiping purposes is typically located on the lower side, which faces away from the upper part 10 , of the lower part 12 . For reasons of clarity, the wiper lip is not illustrated in FIGS. 6 and 7 .
[0074] A windshield wiper device according to embodiments described here uses the effect of tail fins of certain fish, which under the action of lateral pressure do not deflect in the direction of pressure but instead arch in the opposite direction, that is to say in the direction from which the pressure originates. This principle is also referred to as the “fin-ray” principle. In this way, a windshield wiper device according to the embodiments described herein has the advantage of improved adaptation to a windshield of a motor vehicle. In the case of a conventional windshield wiper blade, the upper part thereof is normally rigid, that is to say is not of bendable design.
[0075] FIGS. 6 and 7 show a wiper blade 2 with a longitudinal extent 8 . The windshield wiper device has only one connecting position 34 . Such an arrangement is frequently used for rear windshield wipers. However, the disclosure is not restricted to rear windshield wipers, and the windshield wiper device according to the embodiments described here may also be used for front windshield wipers. Optional refinements and details described in the individual embodiments may generally be used for both variants of an arrangement of a windshield wiper device.
[0076] FIGS. 6 and 7 furthermore show the wiper-blade-side fastening part 20 to which the wiper blade 2 is attached. The wiper-blade-side fastening part 20 is connected to a wiper motor 32 which drives the wiper-blade-side fastening part 20 for the purpose of wiping the windshield 4 . The fastening part 30 may be configured according to the embodiments of the present disclosure. Furthermore, the wiper motor 32 may be connected to the fastening element 50 .
[0077] The wiper blade 2 is configured in a wedge-shaped manner, with one end of the upper part 10 being fixedly connected at an outer connecting position 34 to one end of the lower part 12 . The respective other end of the upper part 10 and of the lower part 12 are fastened to the wiper-blade-side fastening part 20 .
[0078] In FIG. 6 , the wiper blade 2 is illustrated in its position in which it is not placed against the windshield, such that the lower part 12 is of substantially rectilinear design. According to yet further embodiments that may be combined with other embodiments, the lower part in the unloaded state is of convex design, that is to say has a curvature that projects away from the upper part in a central region. The windshield wiper device according to the embodiments described here may then typically, upon making contact with a windshield and proceeding from the convex shape of the lower part, adopt the corresponding concave shape of the lower part that adapts to the windshield.
[0079] In order to illustrate embodiments of the method 200 for mounting a windshield wiper device 100 , a sequence diagram is illustrated in FIG. 8 . According to embodiments of the method 200 , the method 200 comprises providing 201 a windshield wiper device according to the embodiments described herein. Furthermore, the method comprises fastening 202 the wiper-blade-side fastening part to the fastening element by forming the non-positively locking connection and/or positively locking connection between the securing element and the fastening element.
[0080] The embodiments described herein of the windshield wiper device and the method for mounting the windshield wiper device therefore provide a windshield wiper device which can be mounted and dismounted in a simple manner. Accordingly, the windshield wiper device can easily be exchanged in the event of damage or can be removed before passage through a washing system and subsequently mounted again in a simple manner. | The present invention relates to a windscreen wiper device ( 100 ) for a vehicle, with a fastening element ( 50 ). The windshield wiper device ( 100 ) includes a wiper blade ( 2 ) with an elongated upper part ( 10 ) and an elongated lower part ( 12 ) which is at least partially designed to bend. Furthermore, a plurality of connecting elements ( 18 ) for connecting the upper part ( 10 ) and the lower part ( 12 ) is provided, wherein the connecting elements ( 18 ) are spaced apart along a longitudinal extension ( 8 ) of the wiper blade ( 2 ). The connecting elements ( 18 ) are designed to enable a movement of the upper part ( 10 ) and the lower part ( 12 ) relative to one another with a movement component along a longitudinal extension ( 8 ) of the wiper blade ( 2 ). Furthermore, the wiper blade ( 2 ) comprises a wiper blade-side fastening part ( 20 ). The wiper blade fastening element ( 20 ) comprises a securing element ( 22 ) into which the fastening element ( 50 ) is insertable and which is designed to engage the fastening element ( 50 ) to force-fit or form-fit. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject matter of this invention relates generally to high resistance grounded systems and more particularly to high resistance grounding schemes for oil well electrical systems.
2. Description of the Prior Art
Through the years oil well pump installations have utilized an ungrounded high voltage power system. A system of this type allows for the connection of an instrumentation signal system located deep in the well between the neutral of the oil well pump motor and the electrically conducting casing of the well. This saves considerable wiring expense, which would otherwise be necessary to traverse the great distance between the down hole sensor system and the surface signal measurement system. This system has a disadvantage in that the common mode voltage of a three-phase electrical system is not controlled because it is ungrounded and can thus reach extreme levels. This is hazardous to personnel and possibly destructive of electrical insulation. In such a system there is no intentional connection to ground. It has been found, though, that occasionally these ungrounded systems have exhibited unexplained, sometimes very wide spread, insulation failures with catastrophic results. It has been found that the source of these unexplained insulation failures often turns out to be an arcing ground fault condition deep in the well case structure. Severe voltage escalation occurs in these situations and this is what causes the unexplained insulation failures. The solution to this is to unground the power system by connecting the neutral point, supposedly at zero voltage to ground, through a high resistance. High resistance grounding has proven to be the most reliable form of power system grounding. It limits the available fault current to only a few amperes under ground fault conditions and in the event a ground fault occurs, one can continue to operate the system without the need to close down the circuit. This is a desirable feature for continuous process facilities where failure would result in significant losses. The high resistance connection provides damping for the voltage escalation thereby preventing a transient overvoltage from building up and causing failure. At the same time the resistance limits the available fault current to a very low value. The traditional way in the past of applying the high resistance grounding was to connect the neural point of a Wye connected surface power supply system to ground through a resistance, the value of which is selected to allow less than 10 amperes maximum current to flow under the worst case condition. For a Delta system, the neutral point is derived through three grounding transformers or a zig-zag grounding transformer. In the oil field industry, electrically submersible pumps and motors have been traditionally run ungrounded for surface continuity considerations as well as the extremely high cost of pulling the pump and motor up when it has faulted. This provides a perfect application for high resistance grounding. The high resistances grounding will allow the electrically submersible pumps to operate for a longer period of time under ground fault conditions. However, a frequent requirement of the oil well industry is to know what the down hole temperatures, pressures, etc. are. Existing down signals to the surface via line-to-ground connections using the power conductors as part of the signal path. A small signal is superimposed on the power lines and is transmitted to the surface. In this manner extremely expensive control wires of up to 15,000 feet in length are not required. As long as the power system is ungrounded this method is cost effective. However, it does not provide the transient over voltage protection provided by a high resistance grounding system, as the high resistance grounding system will short out the signals on the power conductors. It would be advantageous therefore, if an electrical power system for a down-hole oil well pump could be found that had all the advantageous of high resistance grounding as described previously, but which would also allow for the utilization of the power wiring to carry sensor signals from deep in the well. In the recent past, a system has been found to accomplish both purposes. High resistance grounding is provided but left unconnected until it is needed, as would be the case if an arcing ground fault were detected. That means that signals from an electronic monitoring systems deep in the well can be carried on the power lines of the pump to the surface, utilizing the well casing as a ground conductor. However, if an arcing ground fault occurs, the presence of common mode voltage variation can be quickly sensed at the surface and the high resistance ground can then be quickly inserted into the circuit to limit current and voltage excursions. Once this happens the control system signals are swamped out, but that is an acceptable compromise. At this point in time the protection of the personnel and equipment becomes more important. In the past, this system has utilized a gas discharge switch or tube in series with the grounding resistance. The grounding resistance is interconnected, for example, between the neutral of the power supply transformer and the aforementioned gas discharge tube in turn is interconnected to ground. If the voltage of the neutral of the aforementioned power supply transformer is at zero, then no current flows through the gas discharge tube and it remains an open circuit. If an arcing ground fault begins to cause the common mode voltage at the neutral of the transformer to build up, the current through the high resistance grounding system and the serially connected gas discharge tube causes the gas discharge tube to flash over or conduct thus connecting the high resistance to ground, thus bringing the voltage on the neutral of the aforementioned power transformer back to ground potential. This prevents dangerous arcing ground faults and extreme levels of voltage excursion and also provides a current limiting function. This system has a disadvantage in that the break-over voltage and conduction characteristics of the gas discharge tube, once chosen are fixed for each value of gas discharge tube utilized. It would be advantageous if a high resistance grounding system could be utilized, which was controlled to be in the off state during a time period when it was not needed, but which would be controlled to be turned on by way of a highly reliable system when needed. In such a system, values of current, voltage, etc. could be programmed into the system to provide a wide range of application in a single system. It would be advantageous if such a system could be found which improved the safety of the overall system, which could be used on either Wye or Delta transformers and which provided continuous operation during all ground fault conditions and also provided an alarm to advise personnel of ground fault condition.
SUMMARY OF THE INVENTION
In the present invention, a pair of inverse, parallel connected silicon controlled rectifiers (SCRs) or gated devices are connected between the primary grounding transformer and ground in a signal blocker system (SBS). The SCRs are controlled by circuitry that senses the voltage between the neutral of the output transformer and ground. For Delta connected sources, alternate grounding transformer schemes are utilized. In normal operation the electronic system is interconnected with the neutral of the Wye connected transformer and senses when the neutral to ground voltage begins to deviate substantially from zero. When this happen an electronic sensor system is programmed to cause the inverse parallel gated SCRs to fire, thus connecting the series connected high resistance resistor to ground through the now conducting SBS. A timed out relay coil then closes a normally opened parallel relay contact to continue to provide a current path through the high resistance resistor device to ground, until the fault has been cleared or the system otherwise repaired and made operational again.
In particular, an electrical system of the kind that operates normally in the ungrounded state, but which occasionally is subject to a conductor thereof being grounded, that is, where an undesirable voltage may be generated between a first portion of the electrical system and ground is provided. A grounding impedance device is interconnected to a second portion of the electrical system for reducing the undesirable voltage by connecting it to ground. The control system is interconnected with the grounding impedance device and the electrical system for sensing the undesirable voltage and connecting the grounding impedance device to the second portion of the electrical system for reducing the undesirable voltage. The control device comprises a gated conduction device, such as an SCR system, connected with the impedance for interconnecting the second portion of the electrical system through the impedance. A control device is interconnected with the gated conduction device for causing the gated conduction device to operate in response to the presence of an undesirable voltage. In an embodiment of the invention, the impedance device is primarily resistive and the first and second portions are the same. Furthermore the undesirable voltage is reduced substantially to zero. The system may be Wye connected or Delta connected or a combination of both. In one mode of operation, the system is utilized in an oil well electrical system of the kind which operates normally in the ungrounded state, but which occasionally is subject to a down hole power conductor thereof being grounded, such as for example, through an arcing ground fault. There is a surface located power source and a down hole pump motor driven by the power source. The aforementioned conductor is electrically disposed therebetween and the undesirable voltage is generated between first portion of the surface located power system neutral and ground.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention reference may be had to the preferred embodiment thereof shown in the accompanying drawings in which;
FIG. 1 shows a schematic view, partially broken away, of an electric oil well down hole pump system being driven by a surface power source with down hole signal sensing system and the signal blocker system of the present invention;
FIG. 2 shows a signal blocking arrangement similar to that shown in FIG. 1 for a low voltage embodiment of the invention;
FIG. 3 shows a system similar to FIG. 1, disregarding the down hole portion of the power system, wherein the power system is Delta connected and the signal blocker and associated sensing system is modified accordingly;
FIG. 4 shows a down hole Delta connected pump motor system suitable for use with the surface Wye connected power supply of FIG. 1 or the Delta connected surface power system of FIG. 3 .
FIG. 5 shows a systems similar to that shown in FIG. 3, but for a low voltage arrangement;
FIG. 6 shows a surface connected Delta power supply system utilizing a zig-zag sensing transformer arrangement and medium voltage sensing arrangement;
FIG. 7 shows an arrangement similar to FIG. 6, but for a low voltage sensing and signal blocker system; and
FIG. 8A and B show a schematic diagram of the control system of FIG. 1 for controlling the signal blocker as a function of voltage and current in the power supply and pump system of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and FIG. 1 in particular, FIG. 1 schematically shows an oil well system 10 , which includes an above ground power supply system 11 the heart of which is a Wye connected power transformer secondary winding 12 (transformer) which provides power to a down hole electrical oil well pump 14 having Wye connected oil well pump motor windings 15 . There is provided an electrically conductive well casing or inner production pipe 16 which traverses from the surface S above ground to the down hole region DH over a distance D. Interconnected with the windings 15 of the down hole electrical oil well pump 14 is a signal source 17 . The signal source provides electrical signals to the neutral N′ of the windings 15 , at one terminal thereof and is interconnected with the conductive oil well casing 16 at the other terminal thereof. Above the surface S is a signal receiver 18 . The windings 12 and the windings 15 each have phase lines A, B and C which are interconnected to terminals X, Y and Z and X′, Y′ and Z′ respectively, between which generally traverse the long lines 19 from the surface S to down hole region DH. Signals i a , i b and i c flow in lines A, B and C respectively between the signal source 17 and the signal receiver 18 . Return or ground current i g flows between signal receiver 18 to signal source 17 through the casing 16 of the well. The signals i a , i b and i c may be direct current, pulsed DC or 200 kilohertz ac signals, for example. It is not unusual for the distance D to be approximately 8,000 feet or greater. The signal source 17 may provide information related to well pressure, temperature and vibration for example, from the down hole region DH to surface S by way of the signals i a , i b and i c . The pump motor 14 represented by the windings 15 may be a 60 or 700 horsepower motor of the high voltage variety operating between, for example, 1100 volts and 4600 volts. The signals i a , i b and i c generally range from 4 to 20 milliamps. The power supply system 11 may supply power in the magnitude of 12 hundred to 5 kilovolts at a frequency of 40 to 90 hertz. Generally, the lines 19 may drop 600 volts between the surface S and the down hole region DH due to their excessive length.
The transformer 12 has a neutral N capable of having a common mode voltage V disposed therebetween and ground. In an ideal situation where the power loads are balanced, the voltage V is generally zero volts. The neutral N is interconnected by way of a line to point U of a high resistance grounding system HRG. High resistance grounding system HRG may comprise a step down transformer 20 having the primary P thereof connected at one terminal thereof to the point U and the other terminal thereof connected to the input terminal 23 of a signal blocker 24 . The other side or secondary S of the transformer 20 has connected thereacross a high resistance impedance or resistor R and parallel therewith a relay control device 22 . Between terminal 23 and ground G of the system signal blocker 24 are interconnected an electronic control system 26 (to be described in greater detail with respect to FIG. 8) for the system signal blocker, a normally opened relay 30 and pair of oppositely disposed or inverse connected silicon controlled rectifiers or gated control devices 28 A and 28 B. The control system 26 interconnects with the gated silicon controlled rectifier 28 B interconnected with the control system 26 by way of terminals F and H the voltage across which determine the firing status of silicon controlled rectifier 28 B. On the other hand the silicon controlled rectifier 28 A is controlled by the terminals J and K in the control system 26 , which also has a voltage impressed thereacross which controls the firing status of the silicon controlled rectifier 28 A. The series combination of the resistive element R 28 and capacitive element C 29 will operate with inductor LI to form an RLC circuit that limits the first derivative of system voltage with respect to time, that is the rate of rise of voltage across the silicon controlled rectifiers with respect to time. Said in another way, it is a high frequency filter for variable speed drives, in the event that variable speed drives are being utilized. In normal operation, when the voltage V is at approximately zero volts, the voltage on the primary P of the transformer 20 is essentially at zero and therefor the resistive value R is essentially out of the circuit, the normally opened relay contact 30 remains open and the oppositely disposed silicon controlled rectifiers 28 A and 28 B remain in a nonconductive state. Thus no electrical current flows between the neutral N of the transformer 12 and ground G, thus the resistive value R appears transparent or nonexistent to the voltage on the neutral N of the transformer 12 . However, if an arcing ground fault AF occurs in a first portion of the electrical system, such as is shown in the down hole region DH, between line C and the casing 16 , for example, it has a tendency to reduce the voltage between line C and ground and thus increase the voltage between line A and ground and line B and ground. The increased voltage on lines A and B has a tendency to escalate with the arcing ground fault condition, causing the voltage V on the neutral N of the transformer 12 in a second portion of the electrical system with respect to ground G to obtain some nonzero value. However, the primary P of the transformer 20 sees this voltage increase and reflects it through to the resistive value R. In addition, control system 26 senses the voltage between the point 23 and ground G and actuates the oppositely disposed silicon controlled rectifiers 28 A and 28 B to conduct. This places the resistance R in the circuit between the neutral N and ground G. This limits the current and damp the voltage V at the neutral N to a maximum of a line-to-neutral magnitude. At this point in time, the signals i a , i b and i c are damped out or shorted out by the presence of resistive value R, but this is of no great consequence, as it is more desirable to cure the effects of the arcing ground fault at this time to prevent damage to down hole components. The voltage across the primary P of the transformer 20 , which is reflected into the secondary S thereof actuates the relay control device 22 , which with an appropriate time delay, closes the normally opened contact 30 , thus eliminating the need for the control system to continue to control the silicon controlled rectifiers 28 A and 28 B to conduct and increasing the electronics' life.
The natural effect of all this is to increase the serviceability of the entire system 10 , prevent the destruction of the down hole motor 14 and the sensors as indicated at 17 . In an embodiment of the invention, the net resistive value seen between the neutral N and the ground G may be 130 ohms. The time delay provided by the relay control 22 may be 1.5 seconds. The grounding resistor R may be approximately 6 to 7 ohms. The secondary of the transformer S may be connected to a warning system (not shown) which directly or remotely indicates to personnel that an arcing ground fault has occurred or is occurring. The control system 26 for the signal blocker 24 provides a significant portion of the present invention. Its construction and use will be described hereinafter with respect to FIG. 8 .
Referring now to FIG. 2 an alternate embodiment HRG′ of the high resistance grounding system is shown. In this case transformer 20 is not utilized. In this embodiment of the invention resistor R is directly connected between the neutral N of the transformer 12 (not shown) and ground G by way of a signal blocker 24 ′. Its counterpart shown to the right in FIG. 2 is relay 30 ′. Relay control 22 is interconnected to the terminal N and ground G to cause the normally open relay 30 ′ to close when an appropriate voltage is imposed between the neutral N and ground G as a result of a voltage excursion due to the presence of an arcing ground fault or the like as was described previously. Once the normally open contact 30 ′ closes, it remains that way, thus by-passing the signal blocker 24 ′.
Referring now to FIG. 3, another embodiment of the oil well system 10 ′ is shown in which an above ground power supply 11 ′ having a Delta connected transformer 12 ′ is utilized. For purposes of simplicity of illustration, the down hole or below surface portion of the embodiment is not depicted as it operates in similar fashion to that described previously with respect to FIG. 1 . In this embodiment of the invention, the transformer 12 ′ comprises windings interconnected at common junctions M, O and Q to form a Delta connection. Junctions Q, O and M respectively are carried forward to the high resistive grounding system HRG″ where they interconnect one terminal each with a terminal of primary windings P 1 , P 2 and P 3 of primary winding P of transformer 20 ′. The other sides of the windings P 1 , P 2 and P 3 are tied together and interconnected to the terminal 23 in the manner that was described previously. L 1 , L 2 and L 3 (or equivalent) relays can be used for determining when a phase voltage imbalance has occurred, thus triggering the remaining portion of the signal blocker 24 ′ to actuate in a manner that was described previously. The secondary windings S 1 , S 2 and S 3 of the secondary S of the transformer 20 ′ are tied together in broken delta and have connected there across the resistive element R and relay control device 22 . The resistive element R is reflected through the secondary winding to the primary winding of the transformer 20 ′ to act in a manner as described previously when the signal blocker 24 ′ is actuated by its control system in the presence of ground voltage unbalance a junctions Q, O or M. Once again the relay control device 22 causes the normally open contact not shown in the signal blocker 24 ′ to permanently short out the terminal 23 to ground G.
Referring now to FIG. 4, a Delta connected down hole pump 14 ′ is depicted. In this embodiment of the invention the down hole electrical oil well pump 14 ′ comprises Delta connected windings 15 ′, which interconnect with the signal source 17 in a manner to provide the signal currents i a , i b and i c to the lines A, B and C, to function in the manner that was described previously. As was the case previously, with respect to FIG. 1, the ground current i g for the signal source 17 flows through the casing 16 . It is to be noted with respect to the embodiments of FIGS. 1, 3 and 4 that the above ground power supply arrangement and the down hole electrical oil pump arrangement may be mixed and matched in a convenient manner. That is to say, they both may be Delta connected, they both may be Wye connected, the upper one may be Wye connected and the lower one Delta connected or the upper one Delta connected, and the lower one Wye connected.
Referring now to FIG. 5 an arrangement similar to FIG. 3 but for a low voltage embodiment is depicted. In particular the junctions Q, O and M are shown interconnected with the primary windings P 1 , P 2 and P 3 of the primary P of the transformer 20 ″ of the high resistance grounding circuit HRG″′. The secondary windings S 1 , S 2 and S 3 are interconnected together in a closed delta circuit relationship. When the system voltage across the signal blocker 24 exceeds design value, the system blocker 24 ′ conducts, thus placing the resistance value R into the circuit in the manner that was described previously to basically achieve the results described previously. Once the resistor R conducts electrical current, the voltage thereacross is sensed by the relay control device 22 which in turn causes the relay 30 to close with a time delay as previously described, thus placing the resistor R into the circuit independent of the conduction characteristics of the silicon controlled rectifier within the system blocker 24 ′.
Referring now to FIGS. 6 and 7, two other embodiments of the invention are shown in which a Delta connected transformer secondary 12 ′ for an above ground power supply 11 ′ is interconnected by way of an zig-zag transformer 40 to a signal blocker system 24 . In the embodiment shown in FIG. 6, the high resistance grounding device HRGIV comprises the transformer 20 having the primary thereof interconnected between point 23 and the neutral N″ of zig-zag transformer 40 . The secondary S of the transformer 20 has connected thereacross the resistive value R and the relay control 22 . Once again the control system 26 (not shown) within the system blocker 24 senses the voltages at terminals Q, O and M and acts to reflect the resistive value R between the neutral N″ and the ground G as in the embodiment HRGV of FIG. 6, or directly interconnects the resistive element R between the neutral N′ and the ground G as in the embodiment of FIG. 7 . In the medium voltage embodiment of FIG. 6, the relay control 22 actuates the normally open contact (not shown) to provide a continuous insertion of the resistive element R as reflected though the transform 20 into the appropriate circuit. In the embodiment of FIG. 7, a relay control 22 , upon sensing the voltage drop across the blocker 24 , actuates the relay 30 to again dispose the resistor R into the circuit.
Referring now to FIG. 8 the construction and operation of control system 26 , as it interacts with the remaining elements of the signal blocker 24 will be described. There is shown a resistive element R 2 connected at one end with the junction point 23 as shown previously in FIG. 1, for example. The resistive element R 2 is connected at its other end to an anode of diode D 14 , the negative input terminal ( 2 ) of an operational amplifier U 6 ( 1 ), one side of a resistive element R 18 , one side of a capacitive element C 21 and the cathode of a diode D 13 . There is also shown a resistive element R 3 connected at one side to system ground and at the other side thereof to the cathode of diode D 14 and anode of diode D 13 , the positive terminal ( 3 ) of the operational amplifier U 6 ( 1 ), one side of a resistive element R 19 and one side of a capacitive element C 20 . The other side of a resistive element R 19 and the other side of a capacitive element C 20 are connected to system ground. The other side of capacitive element C 21 and the other side of resistive element R 18 are connected to the output terminal ( 1 ) of the operational amplifier U 6 ( 1 ) and to one side of resistive element R 16 forming a differential amplifier. The other side of resistive element R 16 is connected to the negative input terminal ( 6 ) of operational amplifier U 6 ( 2 ) and to one side each of a resistive element R 17 and a capacitive element C 17 . The other side of the resistive element R 17 is connected to the junction between a resistive element R 21 , one side of a rheostat or variable resistor RHEO and one side of a capacitive element C 19 . The other side of a resistive element RHEO is connected to one side of the resistive element R 20 and one side of a capacitive element C 18 , the other sides of which are grounded. The other side of capacitive element C 19 is grounded and the other side of the resistive element R 21 is connected to the positive 15 volt power supply. The output terminal ( 8 ) of the operational amplifier U 6 ( 2 ) is connected to the other side of capacitive element C 17 and to one side of a resistive element R 14 . The other side of the resistive element R 14 is connected to the anode of a diode D 15 the cathode of which is connected to the positive input terminal ( 7 ) of the operational amplifier U 6 ( 2 ) and to one side of a resistive element R 15 , the other side of which is grounded. The output terminal ( 8 ) of the operational amplifier U 6 ( 2 ) is connected to one side of a resistive element R 12 , the other side of which is connected to input terminals of NAND inverter U 5 , the output of which is connected to the B− input terminal ( 5 ) of a monostable multi-vibrator circuit U 3 . The CTC input terminal of U 3 is connected to the A+ input terminal ( 4 ) thereof and the system ground. The RCTC terminal of U 3 is connected to the junction between a resistive element R 11 and a capacitive element C 15 . The other side of resistive element R 11 is connected to the positive 15 volt power supply and the other side of the capacitive element C 15 connected to ground. The RST terminal of U 3 is connected to a junction between a resistive element R 10 and a capacitive element C 14 . The other side of resistive element R 10 is connected to the positive 15 volt power supply and the other side of the capacitive element C 14 is connected to ground. The output terminal ( 7 ) or Q-bar of U 3 is connected to an input terminal ( 1 ) of a NAND gate device U 4 ( 1 ), the second input terminal ( 2 ) of which is connected to the output terminal ( 4 ) of second NAND gate device U 4 ( 2 ). The output terminal 3 of the U 4 ( 1 ) gate is connected to the input terminal ( 5 ) of U 4 ( 2 ). The two NAND gates are connected together to form a set-reset flip-flop. The input terminal ( 6 ) thereof is connected to a series connected combination of input devices U 4 ( 3 ) and U 4 ( 4 ). The first of these, U 4 ( 3 ), has an input terminal ( 8 ), which is connected to the junction between resistive element R 13 and capacitive element C 16 . This combination forms a power up time delay for the flip-flop reset terminal ( 6 ) of U 4 ( 2 ). The second input ( 9 ) terminal thereof is also connected to the same junction, but through a resistive element R 1 . The other side of the resistive element R 13 is connected to the plus 15 volt power supply and the other side of capacitive element C 16 is connected to ground. The output ( 4 ) of the gate U 4 ( 2 ) is connected to the TB input terminal ( 2 ) of a current mode pulse width modulated circuit U 7 and to the junction between a resistive device Rx and a capacitive element C 24 . The other end of the resistive device Rx is connected to the reference terminal REF at ( 3 ). The resistive element Ry is connected to the RC terminal ( 4 ) of U 7 and to one side of a capacitive element C 22 . The other side of the resistive device Ry is connected to one side of a capacitive element C 23 . The CS terminal of U 7 is connected to one side of the capacitive element C 25 . The other side of the capacitive elements C 22 , C 23 , C 24 , C 25 and the GRND terminal of U 7 are connected to ground. The VCC power supply terminal of U 7 is connected to one side of a resistive element R 5 and one side of a capacitive element C 32 . The other side of capacitive element C 32 is connected to ground, and other side of resistive element R 5 is connected to the positive 24 volt power supply. The output terminal ( 8 ) out of U 7 is connected through resistive element 24 to the gate G of a field effects transistor Q 1 . The source S of the field effects transistor Q 1 is connected to a junction between resistive elements R 4 and R 25 . The other side of resistive element R 25 is connected to the CS terminal of U 7 and the other side of the resistive element R 4 is connected to ground. The drain D of the field effect transistor Q 1 is connected to the anode of a diode D 8 , the cathode of which is connected to one side each of resistive element R 26 and capacitive element C 27 . The other side of capacitive element C 27 is connected to ground and the other side of resistive element R 26 is connected to the 24 volt power supply.
Although not shown for purposes of simplicity of illustration, a power supply for the circuitry of FIG. 8 is provided, which includes ±15 volts and ±24 volts DC power derived in a convenient manner.
Operation of the Control System 26
The differential amplifier formed by utilizing the operational amplifier U 6 ( 1 ) is such that it creates a −0.01 voltage gain between the terminal U and the output terminal ( 1 ) of the operational amplifier U 6 ( 1 ). The voltage is supplied to the capacitor formed by the operational amplifier U 6 ( 2 ). A reference voltage formed across the capacitive element C 19 and controlled by the reostat RHEO cooperates with the voltage disposed at the bottom of the resistive element R 16 , such that if the voltage at pin ( 1 ) of the operational amplifier U 6 ( 1 ) is less than the reference voltage, then the voltage on the output terminal ( 8 ) of the operational amplifier U 6 ( 2 ) will be at a low. On the other hand, if the voltage at terminal ( 1 ) of the operational amplifier U 6 ( 1 ) is higher than the reference voltage, the output at the terminal ( 8 ) of the operational amplifier U 6 ( 2 ) will be at a high. The signal at terminal ( 8 ) of U 6 ( 2 ) is provided to NAND U 5 . As the output of U 6 ( 2 ) goes low to high the output of U 5 goes high to low. The monostable multi-vibrator U 3 is such that when the signal on its pin ( 5 ) undergoes a high to low transition, its Q-Bar output terminal ( 7 ) goes from high to low and then returns to high after a fixed period of time which amounts to the output pulse width PW. This pulse is then feed to the R-S flip-flop formed by the NAND gates U 4 ( 1 ) and U 4 ( 2 ). Thus when the neutral to earth ground voltage V of the secondary 12 of the transformer 11 of FIG. 1 exceeds the reference voltage established across capacitor C 19 the R-S flip-flop is set, that is pin ( 3 ) on U 4 ( 1 ) goes high and pin ( 4 ) on U 4 ( 2 ) goes low. This results in the silicon controlled rectifiers 28 A and 28 B being gated on, thus causing the resistive element R to be interconnected either by way of a reflecting transformer or otherwise between the neutral N and ground of the appropriate power transformer, such as for example, transformer winding 12 of the transformer 11 . In order that the silicon controlled rectifiers do not fire at power up, a low is forced on the flip-flop reset input, that is at pin ( 6 ) of U 4 ( 2 ) for a period of time determined by the time constant of the elements R 15 and C 16 . The current mode PWM integrated circuit is configured such that it forms an oscillator, whose output frequency, which is approximately 10 Khz, is determined by the external RC time constant derived by resistive element Ry and capacitive element C 24 . The pulse train starts when pin ( 2 ) of device U 7 goes low, that is the flip-flop U 4 ( 1 ) is set. When U 7 pin ( 8 ) goes high, the field effect transistor Q 1 is turned on resulting in current build up in the pulse transformer primary S of transformers L 1 and L 3 , which current flows through resistive element R 4 . When there is voltage across resistive element R 4 , that is, when the primary current reaches a certain level, the pin ( 8 ) of device U 7 will go low turning off the transistor Q 1 . The width of this pulse is approximately 2 microseconds. The pulse train continues until the 120 volt ac power, provided to the power supply is turned off. As a result of this, the pulse train is transformed to the secondary of the transformers L 1 and L 3 and the SCRs are continuously gated. The diodes D 9 , 10 , 11 and 12 and the resistive elements R 6 and R 7 are added to form gate input circuits. SCR 28 A is fed by outputs K-J and SCR 28 B is fed by outputs F-H.
It is to be understood with respect to the embodiments of the invention, that the resistive elements shown herein made of different values for different embodiments of the invention and the resistance symbol R is used simply for purpose of simplicity. The transformers 20 and 20 ′, for example, may be different transformer arrangements in different embodiments of the invention, as may be the relay control device 22 and actual system blocker 24 and 24 ′ for example.
The apparatus taught with respect to this invention has many advantages. One advantages lies in the fact that the system blocker may utilize the electronic circuitry on the control system 26 in such a manner as to provide one electronic circuit for utilization with many different kinds and configurations of oil well systems 10 without having to change the control system other than to change control parameters and settings thereon and therein. | A normally ungrounded power system for a oil well is provided which includes a power transformer above ground and a pump motor below ground. There is provided a signal system which includes a below ground sensor system and an above ground signal conditioning and monitoring unit where the sensor system utilizes the main power lines for carrying the sensor signals. A connectable high resistance grounding scheme is provided to the aforementioned floating system, so that in the event of a arcing ground fault or similar occurrence the system may be immediately grounded, thus compensating for the effects of the arcing ground fault and providing personnel safety and electrical equipment protection. When the high resistance grounding system is not utilized the aforementioned signals from the sensors are easily carried by the power conductors. | 4 |
RELATED APPLICATION
[0001] This application claims the benefit of priority to U.S. Provisional Application No. 60/594,660 filed Apr. 27, 2005, the entire contents of which are incorporated herein and made a part hereof.
FIELD OF THE INVENTION
[0002] This application relates to piling repairs and, more specifically, to a unitary pile jacking sleeve adapted for installing and compressively loading new piling without overhead access and without disrupting a deck structure/super-structure.
BACKGROUND
[0003] Pilings of concrete, timber, steel or composite materials are an integral structural part of marine structures, such as bridges, docks, piers and wharves. Pilings, which are driven or jetted into the ground to some determined depth, support a structure above the water's surface. For convenience of reference, the term “ground” is used herein to broadly denote any terrain suitable for supporting a piling, whether it is above water or below water, whether it is natural or man-made, and whether it is comprised sand, rocks, soil, other materials and combinations thereof.
[0004] Unfortunately, the exposure of piling makes them susceptible to degradation. Wood pilings are particularly prone to deterioration from biological infestation as well as structural damage due to overloading, impact, and abrasion. Steel pilings are prone to damage by corrosion and structural overloading and impact. Concrete pilings deteriorate chemically with time and experience structural degradation due to overloading, impact, abrasion and freeze-thaw cycling. A damaged piling typically includes a deteriorated section above or below the soil line that compromises the ability of the piling to support its intended design load.
[0005] While various encasement, wrapping and replacement techniques have emerged to repair such inevitable damage, these techniques have shortcomings. Encasement and wrapping are suitable if the damage has not seriously compromised the structural integrity of the piling. To repair more serious damage, a section of a piling may have to be replaced or the piling may have to be replaced in its entirety. However, conventional replacement techniques (e.g., techniques requiring a crane and pile driving leads) typically require dismantling a portion of the deck structure/super-structure and replacing and loading a damaged section of piling or installing and loading a new piling. Other techniques require complex arrangements of separate couplings to splice in a new pile section. No known techniques provide means for compressively loading a replacement section of pile or installing a new two-piece pile to design specifications.
[0006] As a consequence of the foregoing, there exists a longstanding need for a new and improved system and method for efficiently replacing and loading a damaged section of piling and/or installing and loading new piling. The system and method should enable replacement without dismantling the supported deck structure/super-structure. Additionally, the system should be relatively easy to use and have relatively few separate components (i.e., preferably a unitary component) to facilitate above water, splash zone and underwater application. Furthermore, the system should enable compressively loading a replacement pile to proper design specifications. Moreover, the system should work with various types of pilings of various cross-sectional shapes.
[0007] The invention is directed to overcoming one or more of the problems and fulfilling one or more of the needs as set forth above.
SUMMARY OF THE INVENTION
[0008] To overcome one or more of the problems and fulfill one or more of the needs as set forth above, in one aspect of an exemplary embodiment of the invention, a unitary pile jacking sleeve is provided. The sleeve has a bottom sleeve section, an intermediate sleeve section and a top sleeve section. The bottom sleeve section, intermediate sleeve section and top sleeve section are adapted to structurally support a design load. The bottom sleeve section has an open bottom end and a top end attached to the intermediate section, and the bottom section is adapted to receive through the open bottom end of the bottom section the top end of a bottom pile that has a bottom end secured in the ground. The top sleeve section has an open top end and a bottom end attached to the intermediate section. The top section is adapted to receive the bottom end of a top pile that extends from the open top end to a supported structure. The design load is greater than the weight of the top pile. The intermediate sleeve section being disposed between and adjoining the top sleeve section and the bottom sleeve section.
[0009] In another aspect of an exemplary implementation of the invention, the top sleeve section includes means for enabling lateral (i.e., horizontal) access to the top sleeve section by the top pile. As one example, such means may include a hinged door adapted for enabling lateral (i.e., horizontal) access to the top sleeve section by the top pile.
[0010] In another aspect of an exemplary implementation of the invention, a stationary plate partitions the bottom sleeve section from the intermediate sleeve section, and a floating plate separates the intermediate section from the top section,
[0011] In another aspect of an exemplary implementation of the invention, an aperture provided in the intermediate sleeve section is adapted for allowing insertion and removal of at least one jack into the intermediate sleeve section.
[0012] In another aspect of an exemplary implementation of the invention, a plurality of fastener apertures are provided in the pile jacking sleeve. The fastener apertures are adapted to allow mechanical fasteners to pass therethrough.
[0013] In another aspect of an exemplary implementation of the invention, a plurality of filler apertures are provided in the pile jacking sleeve. The filler apertures are adapted to allow filler material to pass therethrough.
[0014] In another aspect of another exemplary implementation of the invention, a bottom sleeve section, an intermediate sleeve section and a top sleeve section are provided. The bottom sleeve section, intermediate sleeve section and top sleeve section are adapted to structurally support a design load. The bottom sleeve section has an open bottom end and a top end attached to the intermediate section. The bottom section is adapted to receive through the open bottom end of the bottom section the top end of a bottom pile that has a bottom end secured in the ground. The top sleeve section has an open top end and a bottom end attached to the intermediate section. The top section is adapted to receive the bottom end of a top pile that extends from the open top end to a supported structure. The design load is greater than the weight of the top pile. The top sleeve section further includes means for enabling lateral (i.e., horizontal) access to the top sleeve section by the top pile.
[0015] In another aspect of another exemplary implementation of the invention, the means for enabling lateral (i.e., horizontal) access to the top sleeve section by the top pile is comprised of a hinged door adapted for enabling lateral (i.e., horizontal) access to the top sleeve section by the top pile.
[0016] In another aspect of another exemplary implementation of the invention, a stationary plate partitions the bottom sleeve section from the intermediate sleeve section, and a floating plate separates the intermediate section from the top section.
[0017] In another aspect of another exemplary implementation of the invention, an aperture in the intermediate sleeve section allows insertion and removal of at least one jack into the intermediate sleeve section.
[0018] In another aspect of another exemplary implementation of the invention, a plurality of fastener apertures are provided in the pile jacking sleeve. The fastener apertures are adapted to allow mechanical fasteners to pass therethrough.
[0019] In another aspect of another exemplary implementation of the invention, a plurality of filler apertures are provided in the pile jacking sleeve. The filler apertures are adapted to allow filler material to pass therethrough.
[0020] In another aspect of another exemplary implementation of the invention, at least one jack is disposed between the stationary plate and the floating plate, and configured to enable urging the floating plate away from the stationary plate.
[0021] In another aspect of another exemplary implementation of the invention, a jacket surrounds the intermediate sleeve section, top sleeve section, and bottom sleeve section.
[0022] In another aspect of another exemplary implementation of the invention, a solidifying filler is provided between the jacket and the intermediate sleeve section, top sleeve section, and bottom sleeve section.
[0023] In another aspect of yet another exemplary implementation of the invention, a method of repairing a pile using a pile jacking sleeve according to principles of the invention is provided. The method includes sliding the bottom sleeve section down along the bottom pile until the stationary plate rests securely on top of the bottom pile; opening the means for enabling lateral access to the top sleeve section by the top pile; maneuvering the bottom end of the top pile laterally into place through the opened means for enabling lateral access until the bottom end of the top pile rests upon the floating plate; exerting a compressive force against the floating plate to urge the floating plate away from the stationary plate until a determined compressive force is exerted onto the entire pile; and securing the top pile to the top section of the pile jacking sleeve after the determined compressive force is reached. The method may further include encasing the pile jacking sleeve in an encasement and solidifying filler.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The foregoing and other aspects, objects, features and advantages of the invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where:
[0025] FIG. 1 is a perspective view of an exemplary cylindrical pile jacking sleeve according to principles of the invention;
[0026] FIG. 2 is a profile view of an exemplary installed cylindrical pile jacking sleeve according to principles of the invention;
[0027] FIG. 3 is a top sectional view of an exemplary encased cylindrical pile jacking sleeve according to principles of the invention;
[0028] FIG. 4 is a perspective view of an exemplary pile jacking sleeve with a square/rectangular cross section according to principles of the invention;
[0029] FIG. 5 is a profile view of an exemplary installed pile jacking sleeve with a square/rectangular cross section according to principles of the invention; and
[0030] FIG. 6 is a top sectional view of an exemplary encased cylindrical pile jacking sleeve according to principles of the invention.
[0031] Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale. The invention is not limited to the exemplary embodiments depicted in the figures or the shapes, relative sizes, proportions or materials shown in the figures.
DETAILED DESCRIPTION
[0032] One exemplary methodology according to principles of the invention entails removing a damaged upper elevation of a piling by cutting. The damaged section up to the pile cap may be removed. As piling are typically designed to hold several times the weight of a supported pier and structures thereon, damaged sections may typically be removed one at a time, without endangering the stability of the pier or supported structures. Nevertheless, temporary supports (e.g., a crane/false work) may be utilized throughout the repair, out of an abundance of caution, to ensure structural integrity.
[0033] Next an exemplary pile jacking sleeve according to principles of the invention is installed. Referring to FIG. 1 , a perspective view of an exemplary cylindrical pile jacking sleeve 100 is shown. The sleeve 100 includes a bottom section 105 , an intermediate section 110 and a top section 115 .
[0034] As a structural member, the sleeve 100 is designed to be at least as strong as the piling. The sleeve can support the weight of the top section of the piling plus the load that the piling was intended to carry. By way of illustration, without limitation, cylindrical sleeves comprised of steel and having a consistent wall thickness of ¼ to 1 inch (or more) is considered adequate for most applications. Of course, the composition and wall thickness may vary while still providing the requisite structural support and without departing from the scope of the invention.
[0035] The sleeve 100 is sized to engage the piling sections. The cylindrical sleeve 100 has an inner diameter that is about slightly larger than the outer diameter of the piling sections.
[0036] The sleeve includes a plurality of apertures. A plurality of bolt holes 125 are provided to receive bolts or other mechanical fasteners for securing the sleeve to the remaining sections of the piling or new piling. A plurality of optional grout windows 130 are also provided to allow grout to fill the gap between the sections of the piling, between the piling and the sleeve and between the sleeve and an optional jacket. While the windows are displayed as rectangular openings, apertures having other shapes, sizes and proportions may be used. Additionally, at least one window 150 (or a hinged or bolted door) in the intermediate section 110 sized to allow one or more hydraulic jacks to be inserted and removed from the intermediate section 110 of the sleeve is also provided.
[0037] A hinged 145 door 120 with a closure 310 (as shown in FIG. 3 ) is provided in the top section 115 , as a means for enabling lateral (i.e., horizontal) access by a new pile section. When the door 120 is open, the cut end of the new section of piling may be received laterally into the top section 115 of the sleeve. Thus, the bottom section 105 of the sleeve 100 may receive an existing or new bottom section of piling, while the top section 115 of the sleeve 100 may laterally receive a new top section of piling through the open door. Those skilled in the art will appreciate that the hinged door enables the sleeve to couple sections of piling, without dismantling or damaging the supported deck structure/super-structure. Those skilled in the art will further appreciate that one or more hinged doors (e.g., a pair of hinged doors) may be utilized without departing from the scope of the invention. Additionally, the hinged door 120 may pivot along a vertical hinged axis 145 in a conventional door-like manner or along a horizontal hinged axis in a drawbridge-like manner (not shown). Furthermore, other means for enabling lateral (i.e., horizontal) access such as removable panels may be utilized without departing from the scope of the invention.
[0038] A pair of plates 135 and 140 are also provided as pile support structures. A stationary plate 1 35 provides a stable base upon which the sleeve rests on a lower pile section and a jack may be placed. It also provides a surface for evenly distributing forces. The stationary plate, which may be welded or otherwise joined to the sleeve 100 , partitions the bottom 105 from intermediate (i.e., jacking) 110 sections. When extended, the jack is supported by the stationary plate 135 and exerts compressive force against a floating plate 140 , which provides a uniform, hard stable surface to exert and distribute upward forces against the bottom end of the top section of piling. Placing a jack surface directly against the bottom end of the top section of piling would risk damaging the piling. The floating plate 140 may move longitudinally in the sleeve and distributes concentrated jacking forces over the engaged section of the new upper pile. One or more stoppers (e.g., protrusions) may be provided to define a range of motion for the floating plate 140 .
[0039] Referring now to FIG. 2 , a side sectional view of an exemplary installed cylindrical pile jacking sleeve 100 according to principles of the invention is shown. An existing or new pile stub (i.e., bottom section of piling) 200 is received in the bottom section 105 of the sleeve. A plurality of lag bolts or thru bolts 210 secure the bottom section of the piling 200 to the sleeve 100 . The stationary plate 135 rests atop the bottom section of the piling 200 .
[0040] One or more jacks 215 are provided in the intermediate section 110 of the sleeve 100 . Actuation of the jacks 215 forces the floating plate 140 upwardly, away from the stationary plate 135 . The jacks 215 should be positioned and utilize a head that is conducive to even stress distribution and minimizes eccentricity between the jacks 215 and floating plate 140 . One or more force or pressure measuring devices, such as calibrated hydraulic pressure gauges, may be operatively coupled to the jacks 215 to monitor the load. The jacks may be inserted (and optionally removed) through a window 150 (or a hinged door) in the intermediate section 110 . As the sleeve 100 is structurally adequate to support the required load, including the new pile 205 , the jacks 215 may be removed after the new pile 205 is secured to the sleeve. Alternatively, the jacks 215 , which are typically considered expendable, may be left in place.
[0041] A new pile (i.e., top section of piling) 205 is received in the top section 115 of the sleeve 100 . A plurality of lag bolts or thru bolts secure the top section of piling 205 to the sleeve 100 , after the piling 205 has been loaded to a determined design load (i.e., a compressive load) by jacking. The top section of piling 205 rests atop the floating plate 140 .
[0042] During installation, the pile jacking sleeve is first fitted onto the upper end of a bottom pile stub 200 and slid down along the bottom pile until the stationary plate 135 rests securely on top of the bottom pile stub 200 . Next, the one or more jacks 215 are placed between the floating plate 140 and the stationary plate 135 . Alternatively, the jacks 215 are placed between the floating plate 140 and the stationary plate 135 before the pile jacking sleeve is fitted onto the upper end of a bottom pile stub 200 . Next, the hinged pile access door 120 is opened to receive the bottom end of the top (i.e., new) pile 205 . The top pile 205 can then be maneuvered laterally into place through the opened hinged pile access door 120 . When in place, the top pile 205 will extend approximately from the bottom of the supported deck structure/super-structure down to the floating plate 140 . Laterally maneuvering the top pile 205 into place allows the new piling fit into any tight location, beneath a supported deck structure/super-structure, without having to dismantle or damage the supported deck structure/super-structure.
[0043] After the top and bottom piling 200 , 205 , jacks 215 and jack sleeve 100 are in place, the jacks 215 are actuated. Actuation may entail directly or indirectly applying hydraulic pressure or mechanical force to cause the jacks 215 to exert compressive force against the floating plate 140 and the top pile 205 supported thereon. Pile jacking force at any instant may be read from a load indicator operably coupled to the jacks 215 , floating plate 140 and/or top pile 205 . The jacks 215 are actuated until the exerted compressive force levels the supported deck structure/super-structure and/or the compressive force exerted reaches a design load for the supported deck structure/super-structure.
[0044] Once the desired compressive force is achieved, the top pile 205 may be locked into place. For example, a plurality of lag bolts or thru bolts may be used to secure the top section of piling 205 to the sleeve 100 , after the piling 205 has been loaded to the determined design load (i.e., a compressive load) by jacking. As discussed above, the sleeve 100 is structurally adequate to support the required load, including the new pile 205 . Therefore, the jacks 215 may either be removed after the new pile 205 is secured to the sleeve 100 or left in place as expendable support structures.
[0045] Referring now to FIG. 3 , after the piling sections 200 and 205 are secured to the sleeve 100 , the sleeve may optionally be encased in a conventional encasing manner for piling repairs. The encasement may be structural or non-structural. By way of example and not limitation, a rebar lattice comprised of vertical reinforcing bars 315 coupled by horizontal reinforcements 300 (collectively rebar) may be wrapped concentrically around the sleeve 100 . Then a jacket 320 may be wrapped concentrically around the rebar 300 and 315 . The ends of the jacket 320 may be secured together using a form flange 305 or other attachment (e.g., mechanical attachment, weld, or thermal or chemical bond). Spaces between the jacket 320 , rebar 300 and 315 and piling 200 and 205 (e.g., annular space 325 ) may then be filled with an appropriate filler such as concrete, epoxy, cement and/or grout.
[0046] The filler may be introduced in a conventional manner for underwater construction. By way of example and not limitation, pressurized fluid filler may be pumped into the spaces between the jacket 320 , rebar 300 and 315 , jacketed portions of piling 200 , 205 , and other jacketed components using a suitable pump and conduit (e.g., a hose). Upon solidification, the jacket components are securely embedded in the resultantly formed strong, durable, protective filler material.
[0047] Referring now to FIG. 4 , a perspective view of an exemplary rectangular (e.g., square) pile jacking sleeve 400 is shown. The sleeve 400 includes a bottom section 440 , an intermediate section 445 and a top section 450 .
[0048] As a structural member, the sleeve 400 is designed to be at least as strong as the piling. In the exemplary embodiment illustrated in FIG. 4 , the sleeve can support the weight of the top section of the piling plus the load that the piling was intended to carry. By way of illustration, without limitation, rectangular sleeves comprised of steel and having a consistent wall thickness of ¼ to 1 inch (or more) is considered adequate for most applications. Of course, the composition, shape and wall thickness may vary while still providing the requisite structural support and without departing from the scope of the invention.
[0049] The sleeve 400 is sized to engage rectangular or square piling sections. The sleeve 400 is sized slightly larger than the outer dimensions of the piling sections.
[0050] The sleeve includes a plurality of apertures. A plurality of bolt holes 430 are provided to receive bolts or other mechanical fasteners for securing the sleeve to the remaining sections of the piling or new installed piling. A plurality of grout windows 410 is also provided to allow grout (or other filler material) to fill the gap between the sections of the piling, between the piling and the sleeve and between the sleeve and an optional jacket. While the windows are displayed as rectangular openings, apertures having other shapes, sizes and proportions may be used. Additionally, at least one window 455 (or a hinged door) in the intermediate section 445 sized to allow one or more hydraulic jacks to be inserted and removed from the intermediate section 445 of the sleeve is also provided.
[0051] A hinged 435 door 425 is provided in the top section 450 to facilitate new pile installation. When the door 425 is open, the cut end of the new upper piling may be received laterally into the top section 400 of the sleeve. Thus, the bottom section 440 of the sleeve 400 may receive the cut end of the bottom section of the piling or new piling, while the top section 450 of the sleeve 400 may laterally receive the new upper piling through the open door. Those skilled in the art will appreciate that the hinged door enables the sleeve to couple pre-existing and/or new top and bottom pilings or sections of piling, without dismantling or damaging the supported deck structure/super-structure.
[0052] A pair of plates 415 and 420 are also provided. A stationary plate 415 provides a stable base upon which the sleeve rests on a lower pile section and a jack may be placed. It also provides a surface for evenly distributing forces. The stationary plate, which may be welded or otherwise joined to the sleeve 400 , partitions the bottom 440 from intermediate (i.e., jacking) 445 sections. When extended, the jack is supported by the stationary plate 415 and exerts compressive force against a floating plate 420 , which provides a uniform, hard stable surface to exert and distribute upward compressive force against the bottom end of the top section of piling. Placing a jack surface directly against the bottom end of the top section of piling would risk damaging the piling. The floating plate 420 may move longitudinally in the sleeve and distributes concentrated jacking forces over the cross-section of the new upper pile. One or more stoppers (e.g., protrusions) may be provided to define a range of motion for the floating plate 420 .
[0053] Referring now to FIG. 5 , a side sectional view of an exemplary installed square/rectangular pile jacking sleeve 400 according to principles of the invention is shown. A portion 510 of an existing or new pile stub (i.e., bottom section of piling) 500 is received in the bottom section 440 of the sleeve. A plurality of lag bolts or thru bolts (e.g., bolts 600 as shown in FIG. 6 ) secure the bottom section of the piling 500 to the bottom section 440 of the sleeve. The stationary plate 415 rests atop the bottom section of the piling 510 .
[0054] One or more jacks 515 are provided in the intermediate section 445 of the sleeve 400 . Actuation of the jacks 515 forces the floating plate 420 upwardly. One or more force or pressure measuring devices, such as calibrated hydraulic pressure gauges, may be operatively coupled to the jacks 515 to monitor the load. The jacks may be inserted (and optionally removed) through a window (or a hinged door) in the intermediate section 445 . As the sleeve 400 is structurally adequate to support the required load, including the new pile 520 , the jacks 515 may be removed after the new pile 520 is secured to the sleeve. Alternatively, the jacks 515 , which are typically considered expendable, may be left in place.
[0055] A new pile (i.e., top section of piling) 520 is received in the top section 450 of the sleeve 400 . A plurality of lag bolts or thru bolts (e.g., bolts 600 as shown in FIG. 6 ) secure the top section of piling 520 to the top section 450 of the sleeve 400 , after the piling 520 has been loaded to a determined design load by jacking. The top section of piling 520 rests atop the floating plate 420 .
[0056] Referring now to FIG. 6 , after the piling sections 510 and 520 are secured to the sleeve 400 , the sleeve may be encased in a conventional encasing manner for piling repairs. Encasements may be structural or non-structural. By way of example and not limitation, a rebar lattice comprised of vertical reinforcing bars 605 coupled by horizontal reinforcements 620 (collectively rebar) may be wrapped concentrically around the sleeve 400 . Then a jacket 615 may be wrapped concentrically around the rebar 620 and 605 . The ends of the jacket 615 may be secured together using a form flange 610 or other attachment (e.g., mechanical attachment, weld, or thermal or chemical bond). Spaces between the jacket 615 , rebar 620 and 605 and piling 500 and 520 may then be filled with an appropriate filler such as concrete, epoxy, cement and/or grout.
[0057] A pile jacking sleeve according to principles of the invention is not limited to any specific materials. Any materials suitable for marine construction, including, but not limited to, steel, galvanized steel, stainless steel, aluminum, other metals, alloys thereof, and composites may be utilized within the scope of the invention.
[0058] While the invention has been described in terms of various embodiments, implementations and examples, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims including equivalents thereof. The foregoing is considered as illustrative only of the principles of the invention. Variations and modifications may be affected within the scope and spirit of the invention. | A pile jacking sleeve includes a structural sleeve having a bottom section, an intermediate section and a top section. A stationary plate partitions the bottom section from the top section. A floating plate separates the intermediate section from the top section. A hinged door at the top section allows lateral entry of a piling into the top section when the door is open. An aperture allows insertion and removal of at least one jack into the intermediate section. Actuation of the jack urges the floating plate away from the stationary plate, controllably imparting a load to installed piling. A plurality of bolt holes are also provided in the sleeve to secure piling thereto. The sleeve may be jacketed for additional protection. A plurality of grout windows are also provided in the sleeve to enable filling the structure with a solidifying filler. | 4 |
This application is a continuation of U.S. application Ser. No. 12/978,516 filed on Dec. 24, 2010 now U.S. Pat. No. 8,553,919, which is a continuation-in-part of U.S. application Ser. No. 12/896,880 filed on Oct. 2, 2010 which is a continuation-in-part of U.S. application Ser. No. 12/492,035 filed on Jun. 25, 2009 now U.S. Pat. No. 8,107,653 the content of which is incorporated herein by reference and the priority of which is claimed.
FIELD OF THE INVENTION
The invention is in the fields of clothing and wiring for listening to portable audio sources such as MP3 players, CD players, cell phones, Bluetooth devices and the like. In particular for combinations of clothing and such wiring.
BACKGROUND
Wiring assemblies for portable audio sources for listening are ubiquitous. They are generically called headphones. One type of headphones adapted for portable use are called earbuds or earphones. They have at one end a connector to plug into a source device. This then leads to a pair of wires connected to the devices to be placed at the user's ears, usually held in or on the ear.
A user carries the wiring assembly with her and connects it up to the source device and sets the headphones at the ears. The wiring has to be carried and kept available for use, and it is commonly a nuisance to find it and then to use it. In use it is kept usually outside the clothing, the headphones being at the ears and the audio device held in the hand or placed in a pocket.
The wiring may not be waterproof, but recently waterproof wiring has been developed and is available.
Certain special problems are presented with hooded garments designed for children due to the danger of choking presented by lanyards for cinching and cinching in general. To provide such a garment with an audio system presents special problems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of an exemplary type of earphones and wiring which is applicable to the present invention.
FIG. 2 shows a front view of a hooded garment with earphone wiring built into it according to an embodiment of the invention.
FIG. 3 shows a partial view of a garment showing the connector and access wiring extending into a garment pocket.
FIG. 4 shows a partial view of a garment with the wiring in a tube sewn into the inside of a garment and entering the channel of the hood.
FIG. 5 shows a partial view of a garment with a hood showing a cut-away view of the interior of the inside the channel of the hood with the wiring.
FIG. 6 shows the wiring and hollow lanyards as held together in the channel by a barrel.
FIG. 7 is a view showing the wiring and hollow lanyards with a tab attached to the barrel for fixing to the garment.
FIG. 8 is a section view at 8 - 8 of FIG. 7 showing the wiring and hollow lanyards fixed to the casing by means of the tab.
FIG. 9 a is a view of the hollow lanyard with the electrical wire and a connection fitting for connection to an earbud.
FIG. 9 b is a view showing the assembled fitting to the earbud.
FIG. 10 is a view of the channel portion of a hooded garment showing the wiring inside it and an alternative way of fixing the wiring and lanyards against lateral movement.
FIG. 11 is a schematic view of an embodiment of the invention ready for assembly.
FIG. 12 is a schematic view of the embodiment of FIG. 11 showing partial assembly.
FIG. 13 is an assembled view of the embodiment of FIGS. 11 and 12 .
FIG. 14 is an enlarged detailed view of an embodiment of the invention of FIGS. 11 , 12 and 13 .
FIG. 15 is another embodiment of the invention.
FIG. 16 is an embodiment of the invention that is specially configured for garments for children.
FIG. 17 is a partial exploded view of the configuration of FIG. 16 .
FIG. 18 is a partial view of the configuration of FIG. 16 .
DETAILED DESCRIPTION OF THE INVENTION
In the present invention wiring for an audio device, including headphones and earphones are permanently installed into a garment.
An exemplary earphone wiring assembly 10 as in FIG. 1 is of the type including a connector 12 for connecting to an audio source device, typically with paired analog audio transmission wires 14 a and 14 b joined together along a joined wire portion 16 for some distance to a separation point 18 typically having a strain relief member 20 from which the transmission wires 14 a ′ and 14 b ′ extend separately terminating at the earphones 22 a and 22 b . While the term earphone wiring will be used in this description it is intended to mean any of the type with a connection to a source device and a pair of listening instruments, one for each ear. Typically an analog signal travels from the source device to the earphones.
In exemplary form the garment is a hooded garment 30 as shown in FIG. 2 . In other exemplary forms the garment is a conventionally collared shirt, and in still others it has a plain hemmed neck such as a crew neck. In the case of the hooded garment, it may be in jacket form, that is open down the front (with a zipper or other closure means) or in pull-over form like a sweater. However in each case for purposes of embodiments of this invention there is a channel or casing as will be described. In this description the terms left and right refer to the wearer's left and right. As shown in FIG. 2 , the earphone wiring 10 is installed into the garment so that the connector 12 is accessible near a pocket 32 and the right and left earphone wires 14 a ′ and 14 b ′ exit the garment inside hollow lanyards (also called drawstrings) 36 a and 36 b on each side of the hood 34 near the user's ears terminating at the right and left earphones 22 a and 22 b . As will be described in more detail below, the portions of the earphone wiring 10 from the connector 12 to which access is not needed and which runs up to the hood 34 is captured in the garment. Also shown in FIG. 2 are right and left tubular lanyards 36 a and 36 b . These are used to cover the earphone wires 14 a ′ and 14 b ′ and also as the hood lanyards, for adjusting (called cinching) the hood 34 . The hollow lanyards are knitted or may be hollow flexible plastic
FIG. 3 shows an example of how the wire portion 16 extends into the pocket 32 and exits the inner wall of the pocket 32 through an opening 40 so that it is in the inside of the garment 30 , as further described below with reference to FIG. 4
FIG. 4 shows an example of how the earphone wiring 16 is brought from a location inside the pocket 32 into the hood channel 38 . This is done by passing the joined wire portion 16 through an opening 40 inside the pocket, which opening can be a button hole or a grommet to the inside of the garment. Then it enters a first, lower end of and travels through a channel or casing 42 which is sewn into the inside of the garment, in this case along the stitch line 46 that also attaches a zipper 44 . Then it exits the channel 42 at a second, upper end, and enters the hood channel 38 (also called a casing) which is defined by the stitching 48 , through an opening 50 defined by a button hole or other hole device such as a grommet, entering on the side of the hood channel 38 which is on the interior of the hood 34 and extends to the separation point 18 at which the wires separate. Further detail inside the hood channel 38 is described below.
Installation of the wiring can be done with a garment that does not have a pocket, in which case the wiring can simple extend beyond the bottom of the garment, or it can pass through an opening in the garment.
FIG. 5 shows a view of the inside of the hood channel 38 with a portion cut-away to show the interior of the channel. The joined portion 16 comprising the wires 14 a and 14 b enters the hood channel 38 as described above with reference to FIG. 4 , and this portion is placed so that the strain relief member 20 at which they separate is approximately at the center of the hood 34 . The right and left separate wires 14 a ′ and 14 b ′ are installed inside the right and left hollow lanyards 36 a and 36 b respectively. The assembly at the point where the wires 14 a ′ and 14 b ′ exit the strain relief 20 into the hollow lanyards 36 a and 36 b is described in FIGS. 6-8 below. The right and left hollow lanyards 36 a and 36 b with the right and left wires 14 a ′ and 14 b ′ respectively, inside them exit the hood channel 38 through openings 52 a and 52 b , which in this embodiment are on the outside of the hood channel 38 , although they could be on the inside.
FIG. 6 shows an embodiment for a secure “Y” connection of the wires inside the hood channel 38 . In this embodiment the strain relief also called a securing piece 20 is a plastic barrel that has been molded over the separation point 18 where the joined wires 14 a and 14 b separate into the separate wires 14 a ′ and 14 b ′. It is also at this point that the wires 14 a ′ and 14 b ′ enter the hollow lanyards 36 a and 36 b respectively. The securing device 20 tightly holds the ends of the lanyards with respect to each other and the wires. This will be referred to as the securing point 54 .
It is preferable that the lanyards 36 a and 36 b with the wires inside them be attached to the garment inside the hood channel 38 to avoid pulling them laterally in one direction or the other such as by uneven pulling. There are various ways that this can done. One way is to secure the assembly to the garment at or near the securing point 54 . In one embodiment this is done as shown in FIGS. 5 , 7 and 8 with a fabric strip 56 secured around the securing piece 20 , stitching and gluing being exemplary. It is then co-sewn into the hem stitch 46 which defines the casing or channel 38 . The detail is shown in FIG. 8 in which the fabric strip 56 is sewn at 58 to help secure it around the securing piece 20 . Then, after it has been set in place, it is co-sewn with the hood channel hem as shown at 60 .
FIG. 10 shows another embodiment for fixing the lanyard/wire members against lateral movement. In this embodiment, the securing piece 20 is captured between stitch lines 66 on either side. Of course the stitch lines 66 have to avoid the wiring.
As explained above, an embodiment of the invention combines the hood lanyards 36 a and 36 b with the separate wire portions 14 a ′ and 14 b ′ so that the hollow lanyards serve two purposes, one is to tighten the hood, and secondly as conduits for the separate wire portions 14 a ′ and 14 b ′. The ends of the lanyards 36 a and 36 b are secured to the earphones 22 a and 22 b , which in the figures are shown as the earbuds type of earphones.
To manufacture the assembly so that the wiring is permanently installed in the garment, the separate wires 14 a ′ and 14 b ′ are first strung through the lanyards 36 a and 36 b . Then the molded barrel 20 is molded into place at the “Y” junction securing point 54 joining the wires and the lanyards at one end. Then the other ends of the combined lanyards and wires are crimped to a strain relief connection fitting 62 as shown in FIG. 9 a , and then the stripped wire portion 64 is attached to the earbuds 22 a and 22 b and the connection fitting 62 is secured to the earbuds 22 a and 22 b as shown in FIG. 9 b.
While in this description, the terms right and left have been used to understand the location of the lanyards, the wires and the earphones with respect to the garment; it should be understood that the location may but does not necessarily consistently apply to the attachment to a user's left and right ear. A user may attach the left earphone to the left ear and the right earphone to the right ear. But a user can elect to do the opposite; and when the lanyards are tied in a conventional bow, the left and right earphones will reverse their relative location.
A further embodiment is shown in FIGS. 11 , 12 and 13 which are progressive assembly and the enlarged views of FIG. 14 . In FIG. 11 there are shown an earbud 102 ready for assembly to a lanyard assembly 104 . The earbud is made up of a housing 106 a sleeve 108 , (also seen as 62 in the description above) and a speaker or electronics assembly 110 and also a crimp element 112 . The lanyard assembly 104 includes a lanyard 114 (described above as 36 a and 36 b ), typically of woven construction and internal wiring 116 (described above as wires 14 a and 14 b on one side and 14 a ′ and 14 b ′ on the other side). Projecting beyond a terminal end 118 of the lanyard, the internal wiring 116 , which consists of a two wire cable, has been stripped to provide bare wire 120 with terminal ends for connection to the speaker assembly 110 . A glue drop is schematically illustrated at 122 .
The housing 106 has a generally open interior and an opening 124 at its rear end to snugly, or interferingly receive the sleeve 108 and an opening 128 to receive the speaker assembly 110 . The sleeve 108 has a passageway 130 through it from a front end 132 to a rear end 134 . The passageway 130 may be tapered as shown from front to rear. Although it is shown as straight, the sleeve may have another shape with the passageway extending through it accordingly
In FIG. 12 those same elements are shown partially assembled. To perform the assembly, the lanyard assembly 104 has been threaded through the sleeve 108 to extend beyond the front end 132 . Then, the crimp element 112 in the form of coiled wire has been applied proximate the terminal end 118 of the lanyard assembly 104 , and crimped. This can be seen in FIG. 14 . The crimp element 112 secures the lanyard 104 and the wire 116 together so that they are fixed together at that point, that is there can be no relative movement between them and no movement of or force on the lanyard 114 is transmitted to the portions of the wires 120 that will be attached in the earbud speaker assembly 110 . The crimping is also shown in enlarged form in FIG. 14 showing application of the crimp element 112 in the form of a coil of wire before and after crimping. More than one crimp element can be applied to ensure a secure crimp. Other elements can be used as the crimping element which can be closed or crushed down and will secure the lanyard 114 and the wire 120 against relative movement, for example a small lock-washer can be crimped in place. Then, the lanyard assembly 104 is pulled back (see the arrow A in FIG. 14 ) to pull the crimp element 112 into the passageway 130 where it is firmly captured by the wall of the passageway 130 with the bare wires 120 available for connection, as shown in FIG. 12 . This is also shown in FIG. 9 a . The wires 120 are attached to terminals of the speaker assembly 110 and glue 122 is applied into the passageway 130
The sleeve 108 is assembled to the housing 106 and the speaker 110 is assembled to the housing 106 where the parts are all fixed together by sonic welding. This final assembly is shown in FIG. 13 and also in FIG. 9 b.
The wire 120 inside the lanyard 114 is slack as shown by the undulating portion whereby the combination of the slack and the crimping at the end allows any stretching of the lanyard 114 to be applied to the slack of the wire thereby freeing the wire from forces such a pulling on it put on the lanyard 114 and also prevents strain from communicating past the crimp point to the wires inside the housing. That means that as the user pulls on the lanyard such as to tie it or pull the hood tight, due to the slack, the wire 116 will not be subject any stretching or other forces caused by use of the lanyard. In other words, the wire 116 inside the lanyard 114 is independent of the lanyard 114 by reason of the slack and at the same time, the wires 120 beyond the crimp are also free of strain that might be caused by use of the lanyard.
Another embodiment is shown in FIG. 15 in which the lanyard assembly is further developed for a Bluetooth receiver/transmitter 150 . In this embodiment, the connector 12 is connectable to a Bluetooth receiver/transmitter 150 . One of the wires 14 a ′ or 14 b ′ has a microphone 152 connected to it which has an internal pressure switch. The Bluetooth receiver/transmitter 150 is equipped with an on-off switch 154 and other electronic elements common to such devices. The user simply connects the Bluetooth device 150 and can listen to any incoming recorded message or to a live person and can respond by turning on and using the microphone 152 . When the lanyard assembly is used for just listening such as to music via an MP3 player or the like the same wiring performs as described above.
Another embodiment of the invention is described with reference to FIGS. 16 , 17 and 18 .
This embodiment is based on special requirements for children. For children it is not desirable and may be prohibited to allow any means for cinching the hood due to the danger of choking from any dangling cord such as a lanyard or in the case of the present combination from any exposed wiring. The following describes an embodiment of the invention in which there is no lanyard or other cinching means, but does have the built-in wiring and speakers; all the wiring being contained against access or exposure that would create a danger. Also, securing tabs are used at specific points so that the hood cannot be cinched even if the wire is pulled from its accessible end and also to secure the speakers in a selected place in the hood on its right and left sides respectively. The wire from each speaker extends into a hood channel along the hood opening and then into a tube secured to the garment body. The wires can enter the hood channel at any desired selected place. However it is desirable that they enter together and preferably at the center of the hood where the hood seam and the channel stitch line intersect so that it is convenient to leave a space at which the wires enter the hood channel together. The tube is openly secured at the line of joinder of the hood and the body so that the wires pass from the hood channel into the tube with no external exposure or access. A securing tab is installed in the hood at a point proximate to where the wires leave the hood channel and go into the tube. The securing tab is fixed around the wires such as by gluing and is fixed in place by being commonly sewn in the stitch that defines the hood channel. There is a pair of second securing tabs, each one installed proximate one of the speakers. Each of the second securing tabs is fixed around the wire proximate the speaker and is fixed in place by common sewing with the patch that defines the pocket. This helps to hold the wire and the speaker in a relatively fixed position. Also, a protective pad is installed behind each speaker to protect the speakers from shock or other damage such as from a washer or dryer, or simply from being inadvertently struck from outside the hood. The protective pad can be a non-woven fabric such as felt, with sufficient thickness to provide some level of protection, such as 1/32 to ¼ inch thick. It is held in place by being commonly sewn with the patch.
FIG. 16 shows an open view of the subject garment. FIG. 17 is an exploded view of the speaker pocket construction. FIG. 18 shows detail of the speaker pocket construction and the securing tab installation. Referring to FIGS. 16 , 17 and 18 the garment 200 has a hood portion 202 and body portion 204 which are sewn to together along a line of joinder 206 . The hood portion 202 is made with an outside panel 208 and a liner panel 210 . The outside panel 208 has an outer surface 212 which is the exterior of the hood portion 202 and an inner surface 214 . The liner panel 210 has an outer surface 216 which faces the outside panel 208 to define a space 220 between the two panels. A stitch line 222 creates a hood channel 224 within the space 220 . In the space 220 , at a point selected to fit at or near a user's ears are speakers 226 .
Each speaker 226 is secured in a speaker pocket 228 which is made by stitching onto the liner panel 210 a patch 230 . Also, a protective sheet 232 is desirably installed in the speaker pocket 228 on the side of each speaker 226 facing outwardly. For example the protective sheet 232 can be a nonwoven such as felt and can have thickness in the range of about 1/32 to about ¼ inch. The protection will be provided from the hood portion 202 being struck from the outside or from a washing machine or dryer.
Wires 234 A and 234 B extend from the each of the speakers 226 respectively in the space 220 and into the hood channel 224 . While the wires 234 A and 234 B can enter the hood channel 224 separately and at any selected place it is desirable that they enter together and also that they enter at a place where a space in the stitching 222 of the hood channel 224 can be allowed an opening so that they may pass through. This is advantageously done at the center of the hood where a central seam 236 of the liner panel 210 occurs. The wires 234 A and 234 B then extend as a pair in the hood channel 224 to the line of joinder 206 where they pass into the tube 236 . The tube 236 is installed at its top end 238 at the seam of the line of joinder 206 but the stitching is done so that the tube 236 is open into the hood channel 224 . In that way the paired wires 234 A and 234 B can pass into the tube 236 with no outside exposure or access. The tube 236 is attached along its length down the body portion 204 by common stitching with installation of a zipper 240 and terminates at a bottom end 242 as near as practical to an opening 244 into pocket 246 (see pocket 32 in FIG. 3 ). The opening 244 is desirably a button hole or a grommet. As described above in other embodiments, the paired wires 234 A and 234 B are terminated to a connector (see connector 12 in FIG. 3 ) which is accessible into the pocket 246 , from outside the garment.
As seen in FIG. 16 , in the hood channel 224 , close to the line of joinder 206 a securing tab 248 is fixed to the paired wires 234 A and 234 B It can be fixed by gluing or other means. The securing tab 248 is commonly stitched with the stitching 222 that forms the hood channel 224 . The securing tab 248 will prevent any strain from pulling on the paired wires 234 A, 234 B thereby preventing any cinching of the hood portion 202 .
As seen in the magnified view of FIG. 18 , there is a securing tab 250 fixed on each of wire 234 A and 234 B as it is attached to the respective speaker 226 and is commonly stitched with the patch 230 along stitching 222 . The securing tab 250 then prevents any strain on the respective wire from being transmitted to its point of attachment to the speaker, and also helps steady the speaker in position in the speaker pocket 228 .
The foregoing Detailed Description of exemplary and preferred embodiments is presented for purposes of illustration and disclosure in accordance with the requirements of the law. It is not intended to be exhaustive nor to limit the invention to the precise form or forms described, but only to enable others skilled in the art to understand how the invention may be suited for a particular use or implementation. The possibility of modifications and variations will be apparent to practitioners skilled in the art. No limitation is intended by the description of exemplary embodiments which may have included tolerances, feature dimensions, specific operating conditions, engineering specifications, or the like, and which may vary between implementations or with changes to the state of the art, and no limitation should be implied therefrom. This disclosure has been made with respect to the current state of the art, but also contemplates advancements and that adaptations in the future may take into consideration of those advancements, namely in accordance with the then current state of the art. It is intended that the scope of the invention be defined by the Claims as written and equivalents as applicable. Reference to a claim element in the singular is not intended to mean “one and only one” unless explicitly so stated. Moreover, no element, component, nor method or process step in this disclosure is intended to be dedicated to the public regardless of whether the element, component, or step is explicitly recited in the Claims. No claim element herein is to be construed under the provisions of 35 U.S.C. Sec. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for . . . ” and no method or process step herein is to be construed under those provisions unless the step, or steps, are expressly recited using the phrase “comprising step(s) for . . . ” | An audio source system may be built into a garment such as a hooded garment in such a way that safety concerns such as with a hooded garment for children are taken into account so that the audio system wiring cannot be made loose causing a danger of strangulation nor can the hood be cinched. This is done by putting speakers into the hood between a lining and an outer layer and passing the wires into the space between them and then into a tube that is open to the hood inner space and down the tube to a pocket in the body of the garment. Also securing tabs are used to prevent cinching action upon pulling the wire. | 7 |
This is a continuation of U.S. patent application Ser. No. 06/882,649, filed July 7, 1986 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to strutless synchronizers for manual transmissions and more particularly to an improved blocking ring strutless synchronizer incorporating resilient torque generating annular springs.
Strutless synchronizers, such as disclosed in the U.S. Pat. No. 3,700,083 issued Oct. 29, 1972 to N. Ashikawa et al. are well known in the synchromesh transmission art. The '083 patent employs a D-section annular spring interposed between a sleeve, slidably mounted on a hub spline of a main shaft, and a blocking ring provided on the conical slidable surface of a speed ratio gear. The annular spring is slidably mounted in a snug manner on the outer surface of three uniformly spaced axially extending lugs integrally formed as the blocking ring. The annular spring interposed between the sleeve and the blocking ring lugs is so arranged that upon movement of the sleeve, the annular spring is first pushed axially by certain of the sleeve internal uniformly spaced splines. This in turn causes the annular spring to axially push the blocking ring. The blocking ring is then seated on the gear cone which, having a relative rotational speed, generates a cone torque to index or clock the blocking ring to the desired blocking position. Once synchronization is complete, the annular spring is then compressed and deflected radially inward by the sleeve as the sleeve passes over the spring. As a result, the sleeve internal splines mesh with a driven gear journaled on the main shaft and thus rotation of the main shaft is transmitted to the driven gear.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to provide an improved strutless synchronizer employing an annular spring captured in three axially spaced grooved lugs formed on the blocker ring. The annular spring is of a predetermined uniform circular cross-section greater than the depth of the grooves. Also, the annular spring has a predetermined inner diameter slightly greater than the diameter defined by the base of the grooves. The unique relationship of the annular spring and the lug grooves allows the annular spring to undergo slight rotational travel relative to the blocker ring. The annular spring rotational travel results each time it is contacted by inclined surfaces of radial teeth on at least three equally spaced sleeve internal splines while the sleeve is moved axially. This construction greatly extends the service life of the annular spring as a result of the continuously changing contact area between the sleeve chamfered radial teeth as they compress and radially inwardly deflect the annular spring. The grooved lugs also restrict the annular spring from axial movement on the blocker ring, thereby insuring instant release of the frictional forces between the blocking ring and drive gear sliding conical surfaces and consequent unloading of the blocking ring.
A further object of the present invention is to maintain the break-through load from the time the sleeve splines gage point contacts the annular spring to the time it contacts with the pitch point of the ring teeth. This is accomplished by providing a dual chamfer or ramp on at least equally spaced sleeve internal splines. A first steep ramp initially contacts the annular spring and loads the annular spring which in turn loads the blocking ring. This load rotates the lugs on the blocking ring into engagement with their associated hub notches. At this point the running clearance between all the axially moving parts has been taken up, and the chamfer of the synchronizer sleeve and blocking ring splines are indexed into axial alignment. The sleeve will continue to radially compress the annular spring inwardly thereby generating a break-through load that insures proper blocking action by the blocking ring. A second reduced ramp provided on the spline teeth is operative to extend the time interval during which the break-through load is generated. This extended time interval insures that the pitch points on the sleeve splines and the blocking ring teeth are brought into contact prior to the release of the break-through load.
Reference may be had to the Society of Automotive Engineers Report No. 680008 published January, 1968, titled "Manual Transmission Synchronizer" by Richard J. Socin and L. Kirk Walters. This report, adopted by reference herein, provides a detailed discussion of general design requirements affecting synchronizer performance together with definitions of terms relative to the art.
Further objects and advantages of the present invention will be apparent from the following description, reference being made to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial longitudinal cross-sectional view of the synchronizing mechanism according to this invention;
FIG. 1A is an enlarged fragmentary view of a portion of FIG. 1 within circle designated 1A;
FIG. 2 is an enlarged exploded perspective view of a portion of the synchronizer mechanism shown in FIG. 1;
FIG. 3 is an enlarged fragmentary cross-sectional view, with parts broken away, taken substantially on the line 3--3 of FIG. 1;
FIG. 4 is a fragmentary cross-sectional view taken on the line 4--4 of FIG. 3;
FIG. 5 is a fragmentary cross-sectional view taken on the line 5--5 of FIG. 3;
FIG. 6 is a fragmentary cross-sectional view similar to FIG. 5 showing the sleeve moved to the right engaging the blocking ring and the right hand ratio gear;
FIG. 7 is a fragmentary elevational view taken in the direction of arrow 7 of FIG. 3 with the outer sleeve removed; and
FIG. 8 is an enlarged fragmentary cross-sectional view of one of the left blocking ring grooved lug and its annular spring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings there is seen in FIG. 1 a transmission shaft 10, on which are rotatably supported a pair of ratio gears 12 and 14. Disposed between the ratio gears 12 and 14 is a pair of left and right synchronizer assemblies 16 and 18 which are operable to cause selective speed synchronization between shaft 10 and ratio gears 12 and 14, respectively. The synchronizer assemblies 16 and 18 are operated through a shift sleeve 20 which is connected by a yoke groove 22 to a conventional mechanical shift fork mechanism partially shown at 24. FIG. 2 of the drawings shows the synchronizer assembly 16 in an exploded perspective view. As the synchronizer assembly 18 is substantially identical with the synchronizer assembly 16, like or similar parts will operate in a similar manner except for their direction of travel. The synchronizer assemblies include a common hub 26 fixedly connected to the main shaft 10 through internal splines 28 engaging external splines 30 on the main shaft as seen in FIG. 1. The snap ring 31 positions the hub 26 axially on the shaft 10. The sleeve 20 is mounted on the hub 26 by means of hub external splines or splined surface 32 engaging sleeve internal splines or splined surface 34. Thus, the sleeve 20 is axially slidable on the hub 26 by means of the shift fork mechanism 24. It will be noted that the ratio gears 12 and 14 are journaled on the shaft 10 for rotation relative thereto.
The synchronizer assemblies 16, 18 each includes a respective blocking or clutch ring 36 and 37 having inner conical surfaces 38 and 38' which slide on associated outer peripheral conical surfaces 39 and 39' formed on gear cone portions 40 and 42, respectively. The ratio gear 12 has a toothed outer diameter or surface 42 adapted to mesh with other gear members in a well known manner. An inner clutch toothed surface 44 on gear 12 is coaxial and alignable with a splined toothed surface 46 formed on the outer circumference of synchronizer blocking ring 36. Both toothed surfaces 44 and 46 are engageable by the internal splined surface 34 of the shift sleeve 20. It will be noted that the splined surface 34 is in continual engagement with the hub exterior splined surface 32.
Circular resilient left and right annular springs 48 and 50 are mounted on their associated blocking rings 36 and 37, respectively. The annular springs 48 and 50 are each retained in a snap-action manner in three identical circumferential left and right sets of grooves 52 and 54, respectively, formed in radially extending sets of lugs 56 and 58 equally spaced at 120 degree intervals around their associated blocking rings 36 and 37. As best seen in FIG. 8, the left set of grooves 52 in lugs 56 have a predetermined depth so as to axially capture three equally spaced portions of the right annular spring 50 in a snap-action manner. The right set of grooves 54 capture the annular spring 50 in an identical manner.
It will be seen in FIG. 8 that the circular-cross section of the annular spring is formed with a diameter "A" which in the disclosed embodiment has a diameter of about 1.50 mm while the groove 52 has a depth "B" of about 0.75 mm. That is, the annular spring diameter is at least twice the depth of the groove 52. Further, the diameter "C" defined by the lugs outer surfaces is about 83.50 mm while the internal diameter "D" (FIG. 3) of the annular spring 50 is about 84.70 mm. Thus, the annular springs 48 and 50 are axially retained or captured by their associated sets of grooves 52 and 54. Because of the clearance provided by the grooves, however, the annular springs are free to travel about the axis of the shaft 10 relative to their associated blocking ring. Thus, the annular spring will be contacted at random locations by certain sleeve internal spine radial teeth portions to be described.
With reference to FIG. 1 the sleeve 20 is shown located in its neutral or axially centered position relative to hub 26 by means of the two annular springs 48 and 50. The annular springs 48 and 50 have their inner surfaces in light contact with their associated left and right longer projecting or radial teeth portions 60 and 62, respectively, on the inner surface at each end of the spline. In a manner identical to the synchronizer assembly 16, the synchronizer assembly 18 has its right blocking ring 37 formed with a toothed surface defined by external teeth 64. Also, the ratio gear 14 has an inner toothed surface or teeth 66 coaxial and alignable with toothed surface 64. The ratio gear 14 also has a toothed outer surface 68 adapted to mesh with other gear members.
As shown and described in the above mentioned U.S. Pat. No. 3,700,083, the projections or radial teeth portions 60 and 62 are formed at each axial end of three pair of uniformly spaced sleeve internal splines 34. With reference to FIGS. 2 and 3 there is provided three pair of the 120 degree spaced splines 34' each formed with radial teeth portions 60 and 62 at their left and right ends, respectively. It will be noted that in FIG. 3 a reduced number of splines 34 and blocking ring teeth 46 are shown in this enlarged view for purposes of clarity. FIG. 2 shows a preferred embodiment of applicant's invention with an increased number of splines 34 and teeth 46 depicted.
As seen in FIG. 2, the hub external splines 32 are interrupted at three uniformly spaced locations by notches 69 axially centered to receive associated blocking ring lugs 56 therein. FIG. 7 of the drawings shows a right lug 58 nested within its associated notch 69 defined by opposed radially extending surfaces 70. FIG. 2 also shows the sleeve having its internal splines 34 interrupted at three uniform spline locations 72 for reception of an associated pair of wide splines 74 defining each notch 69.
With reference to FIG. 1a it will be noted that each radial tooth 62 has a compound beveled ramp 63 comprising a first steep angle ramp portion 76 and a second reduced angle ramp portion 77. The purpose of such compound or double chamfered face 63 will be explained below. Further, it will be observed that during indexing or clocking of the blocking rings their associated lugs 56 and 58 have their respective side faces 78 and 80 adapted to contact an associated notch face 70.
In operation upon the sleeve 20 being shifted to the right from its neutral position of FIG. 1, each pair of radial teeth portions 62 initial steep angle ramp portions, shown at 76 in FIG. 1A, contacts the annular spring 50. At this point the running clearance between all the axially moving parts has been taken up. Next a detent load builds up as the annular spring 50 is compressed radially by the sleeve teeth 62 before the pitch points of the sleeve splines 34' and ring teeth 64 come into initial contact. It will be noted that the pitch points are located on the pitch diameter indicated by the construction line 79 in FIG. 5. Thus, for example, the pitch points for the teeth 66 is indicated at "E", the pitch point for the teeth 64 is indicated at "F", and the pitch point for the spline 34' radial teeth portions 62 is indicated at "G".
The initial steep ramp portions 76 also radially compress the annular spring 50 generating the cone torque on the right blocking ring 37. This cone torque results from a metal-to-metal frictional contact developed at the interface of the ring and gear cone surfaces 38' and 39', respectively. This cone torque or break-through load insures proper blocking action between the chamfers on the sleeve internal spline teeth 62 and the blocking ring teeth 64.
As the sleeve 20 continues to be shifted to the right a second reduced angle ramp portion 77 (FIG. 1A) contacts and continues to inwardly compress the annular spring 50. The second reduced ramp portion 77 extends the time duration of the generation of the break-through load. This extended break-through load time interval insures proper blocking action prior to the unloading of the annular spring to its position shown in FIG. 6.
The sequence of synchronizer events from neutral to full engagement may be summarized by the following six steps:
1. The sleeve moves from neutral to its detent position wherein the six radial teeth 62 contact the annular spring.
2. The detent load builds-up on the annular spring.
3. The blocker ring rotates or clocks to index its teeth with the sleeve spline teeth 62.
4. The blocker ring is energized by the sleeve teeth chamfers contacting the ring teeth chamfers.
5. The blocker ring and annular spring are unloaded and the sleeve passes through.
6. The ratio gear teeth 66 move aside to pass the sleeve splines and complete the synchronizer lockup.
It will be noted on FIG. 1A that the initial steep ramp portion 76 defines an angle X with the horizontal while the reduced ramp portion defines an angle Y with the horizontal. In the disclosed embodiment the angle X is about 35 degrees from the horizontal while the reduced ramp angle Y is about 25 degrees from the horizontal.
Although only one embodiment of the invention has been illustrated and described, it is apparent that modifications and variations will readily come to mind of a person skilled in the art which modifications and variations do not fall outside the scope of the invention as defined by the following claims. | An improved strutless synchronizer has an annular spring interposed between an internally splined sleeve, mounted for axial sliding movement on a main shaft, and an associated blocking ring. Selected ones of the sleeve splines are formed at the extremities with radially inwardly extending teeth. Each of the teeth has a dual chamfered face portion in opposed relation with the annular spring. The blocking ring has three equally spaced lugs each formed with a transverse groove sized to axially capture the annular spring so as to allow the spring freedom to rotate in its grooves relative to the blocking ring. Each time the sleeve is moved toward meshed engagement with an associated main shaft ratio gear its spline teeth chamfered faces compress the spring at random points thereby minimizing spring wear. Also, the grooves, by positively retaining the spring, insure instant unloading of the blocking ring. | 5 |
FIELD OF THE INVENTION
[0001] This invention relates generally to memory element design. More particularly, this invention relates to improving soft error immunity in latches.
BACKGROUND OF THE INVENTION
[0002] High-energy neutrons lose energy in materials mainly through collisions with silicon nuclei that lead to a chain of secondary reactions. These reactions deposit a dense track of electron-hole pairs as they pass through a p-n junction. Some of the deposited charge will recombine, and some will be collected at the junction contacts. When a particle strikes a sensitive region of a latch, the charge that accumulates could exceed the minimum charge that is needed to “flip” the value stored on the latch, resulting in a soft error.
[0003] The smallest charge that results in a soft error is called the critical charge of the latch. The rate at which soft errors occur (SER) is typically expressed in terms of failures in time (FIT).
[0004] A common source of soft errors are alpha particles which may be emitted by trace amounts of radioactive isotopes present in packing materials of integrated circuits. “Bump” material used in flip-chip packaging techniques has also been identified as a possible source of alpha particles.
[0005] Other sources of soft errors include high-energy cosmic rays and solar particles. High-energy cosmic rays and solar particles react with the upper atmosphere generating high-energy protons and neutrons that shower to the earth. Neutrons can be particularly troublesome as they can penetrate most man-made construction (a neutron can easily pass through five feet of concrete). This effect varies with both latitude and altitude. In London, the effect is two times worse than on the equator. In Denver, Colo. with its mile-high altitude, the effect is three times worse than at sea-level San Francisco. In a commercial airplane, the effect can be 100-800 times worse than at sea-level.
[0006] Radiation induced soft errors are becoming one of the main contributors to failure rates in microprocessors and other complex ICs (integrated circuits). Several approaches have been suggested to reduce this type of failure. Adding ECC (Error Correction Code) or parity in data paths approaches this problem from an architectural level. Adding ECC or parity in data paths can be complex and costly.
[0007] At the circuit level, SER may be reduced by increasing the ratio of capacitance created by oxides to the capacitance created by p/n junctions. The capacitance in a latch, among other types, includes capacitance created by p/n junctions and capacitance created by oxides. Since electron/hole pairs are created as high-energy neutrons pass through a p/n junction, a reduction in the area of p/n junctions in a latch typically decreases the SER. Significant numbers of electron/hole pairs are not created when high-energy neutrons pass through oxides. As a result, the SER may typically be reduced by increasing the ratio of oxide capacitance to p/n junction capacitance in a SRAM cell.
[0008] There is a need in the art to reduce the SER in latches. An embodiment of this invention reduces the SER in memory elements.
SUMMARY OF THE INVENTION
[0009] In a preferred embodiment, the invention provides a circuit and method for reducing soft error events in memory elements. A first transfer gate is connected to an first input of a first tristatable inverter, a second input of a second tristatable inverter, and the output of a third tristatable inverter. A second transfer gate is connected to an first input of the second tristatable inverter, a second input of the first tristatable inverter, and the output of a fourth tristatable inverter. The output of the first tristatable inverter is connected to the first input of the third tristatable inverter and the second input of the fourth tristatable inverter. The output of the second tristatable inverter is connected to the second input of the third tristatable inverter and the first input of the fourth tristatable inverter. The input of an inverter is connected to the output of the fourth tristatable inverter.
[0010] Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic diagram of a transfer gate, a latch, and an inverter. Prior Art
[0012] FIG. 2 is a schematic diagram of a transfer gate, a latch, and an inverter. Prior Art
[0013] FIG. 3 is a schematic diagram of a memory element.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] FIG. 1 is a schematic diagram of a transfer gate, a latch, and an inverter. An input, 100 , is connected to the input of transfer gate, 104 . The output, 106 , of the transfer gate, 104 , is connected to the input/output of the latch, 108 . Control signal, 102 , controls when the signal on the input, 100 , of the transfer gate, 104 , is transferred to the output, 106 , of the transfer gate, 104 . The signal presented at the output, 106 , is stored on the latch, 108 . The signal, 106 , stored on the latch, 108 , drives the input, 106 , of the inverter, 116 . In this example, the output, 118 , of the inverter, 116 , has the opposite sense of the signal stored on the latch, 108 . In this example, a latch comprises two inverters, 110 and 112 , where the output, 114 , of one inverter, 110 , is connected to input, 114 , of another inverter, 112 and the output, 106 , of one inverter, 112 , is connected to the input, 106 , of another inverter, 110 .
[0015] After control signal, 102 , is turned off, the signal, 106 on the latch, 108 , is usually retained. If, however, a soft error event disturbs the charge stored on the latch, the original signal may be lost and the output, 118 , of inverter, 116 , may be changed from its original logical value.
[0016] FIG. 2 is a schematic diagram of a transfer gate, a latch, and an inverter. An input, 200 , is connected to the input of transfer gate, 204 . The output, 206 , of the transfer gate, 204 , is connected to the input/output of the latch, 208 . Control signal, 202 , controls when the signal on the input, 200 , of the transfer gate, 204 , is transferred to the output, 206 , of the transfer gate, 204 . The signal presented at the output, 206 , is stored on the latch, 208 . The signal, 206 , stored on the latch, 208 , drives the input, 206 , of the inverter, 216 . In this example, the output, 218 , of the inverter, 216 , has the opposite sense of the signal stored on the latch, 208 .
[0017] In this example, a latch, 208 , comprises two inverters, 210 and 212 , where the output, 214 , of one inverter, 210 , is connected to input, 214 , of another inverter, 212 and the output, 206 , of one inverter, 212 , is connected to the input, 206 , of another inverter, 210 . In this example, inverter 210 comprises a PFET, MP 1 , and an NFET, MN 1 . The gates, 206 , of PFET, MP 1 , and NFET, MN 1 , are connected. The source of PFET, MP 1 , is connected to VDD and the source of NFET, MN 1 , is connected to GND. The drains of PFET, MP 1 , and NFET, MN 1 , are connected at node 214 . In this example, inverter 212 comprises a PFET, MP 2 , and an NFET, MN 2 . The gates, 214 , of PFET, MP 2 , and NFET, MN 2 , are connected. The source of PFET, MP 2 , is connected to VDD and the source of NFET, MN 2 , is connected to GND. The drains of PFET, MP 2 , and NFET, MN 2 , are connected at node 206 . Inverter 216 comprises a PFET, MP 3 , and an NFET, MN 3 . The gates of PFET, MP 3 , and NFET, MN 3 , are connected at node 206 . The source of PFET, MP 3 , is connected to VDD. The source of NFET, MN 3 , is connected to ground. The drains of PFET, MP 3 , and NFET, MN 3 , are connected at node 218 . In this example, inverters, 210 , 212 , and 216 were implemented using PFETs and NFETs. Other implementations of an inverter may be used.
[0018] After control signal, 202 , is turned off, the signal, 206 on the latch, 208 , is usually retained. If, however, a soft error event disturbs the charge stored on the latch, the original signal may be lost and the output, 218 , of inverter, 216 , may be changed from its original logical value.
[0019] FIG. 3 is a schematic diagram of a memory element. An input, 300 , is connected to the input of transfer gate, 304 and transfer gate, 306 . The output, 308 , of the transfer gate, 304 , is connected to the first input of the tristatable inverter, 316 , the second input of tristatable inverter, 326 , and the output of tristatable inverter, 332 . The output, 310 , of the transfer gate, 306 , is connected to the first input of the tristatable inverter, 326 , the second input of tristatable inverter, 316 , and the output of tristatable inverter, 338 .
[0020] Control signal, 302 , controls when the signal on the input, 300 , of the transfer gate, 304 , and transfer gate, 306 , is transferred to the output, 308 , of the transfer gate, 304 , and to the output, 310 , of the transfer gate, 306 . The signal presented at the output, 308 , of transfer gate 304 drives the first input of the tristatable inverter, 316 . Since the signal presented at the output, 310 , is the same signal as presented at output, 308 , the second input of the tristatable inverter, 316 , has the same logical value as the first input to the tristatable inverter, 316 . Because the signals on the inputs of the tristatable inverter, 316 , have the same logical value, the tristatable inverter, 316 , acts like an inverter and outputs a signal, 318 with the opposite logical value as the input.
[0021] The signal presented at the output, 310 , of transfer gate 306 drives the first input of the tristatable inverter, 326 . Since the signal presented at the output, 308 , is the same signal as presented at output, 310 , the second input of the tristatable inverter, 326 , has the same logical value as the first input to the tristatable inverter, 316 . Because the signals on the inputs of the tristatable inverter, 326 , have the same logical value, the tristatable inverter, 326 , acts like an inverter and outputs a signal, 320 with the opposite logical value as the input.
[0022] The signal presented at the output, 318 , of tristatable inverter 316 drives the first input of the tristatable inverter, 332 . Since the signal presented at the output, 320 , of tristatable inverter 326 is the same signal as presented at output, 318 of tristatable inverter 316 , the second input of the tristatable inverter, 332 , has the same logical value as the first input to the tristatable inverter, 332 . Because the signals on the inputs of the tristatable inverter, 332 , have the same logical value, the tristatable inverter, 332 , acts like an inverter and outputs a signal, 308 with the opposite logical value as the input. The logical value on the output, 308 , of tristatable inverter 332 reinforces the value, 308 , on the tristatable inverter 316 .
[0023] The signal presented at the output, 320 , of tristatable inverter 326 drives the first input of the tristatable inverter, 338 . Since the signal presented at the output, 318 , of tristatable inverter 316 is the same signal as presented at output, 320 of tristatable inverter 326 , the second input of the tristatable inverter, 338 , has the same logical value as the first input to the tristatable inverter, 338 . Because the signals on the inputs of the tristatable inverter, 338 , have the same logical value, the tristatable inverter, 338 , acts like an inverter and outputs a signal, 310 with the opposite logical value as the input. The logical value on the output, 310 , of tristatable inverter 338 reinforces the value, 310 , on the tristatable inverter 326 .
[0024] After control signal, 302 , is turned off, the logical values stored on nodes 308 , 310 , 318 , and 320 are usually retained. In this embodiment, if a soft-error event disturbs node 308 and only node 308 , node 308 will be recovered to its original logical value. In this embodiment, if a soft-error event disturbs node 310 and only node 310 , node 310 will be recovered to its original logical value. In this embodiment, if a soft-error event disturbs node 318 and only node 318 , node 318 will be recovered to its original logical value. In this embodiment, if a soft-error event disturbs node 320 and only node 320 , node 320 will be recovered to its original logical value.
[0025] For example, if the memory element has a logical one stored on it and transfer gates, 304 , and 306 are off, node 308 is a logical high value, node 310 is a logical high value, node 318 is a logical low value, and node 320 is a logical low value. In this example, if a soft error event disturbs node 308 from a logical high value to a logical low value, node 318 will remain a logical low value because PFET, MP 1 , is off and NFET, MN 1 is off, tristating tristatable inverter, 316 . Because tristatable inverter, 316 , is tristated, node 318 retains its original low value. Since node 318 is a logical low value, tristatable inverter, 332 , actively drives node 308 back to its original high logical value. Since node 308 is recovered to its original high logical value, tristatable inverter, 316 , is no longer tristated. Instead tristatable inverter, 316 , actively drives node 318 to a low logical value.
[0026] Another example is, if the memory element has a logical one stored on it and transfer gates, 304 , and 306 are off, node 308 is a logical high value, node 310 is a logical high value, node 318 is a logical low value, and node 320 is a logical low value. In this example, if a soft error event disturbs node 310 from a logical high value to a logical low value, node 320 will remain a logical low value because PFET, MP 3 , is off and NFET, MN 3 is off, tristating tristatable inverter, 326 . Because tristatable inverter, 326 , is tristated, node 320 retains its original low value. Since node 320 is a logical low value, tristatable inverter, 338 , actively drives node 310 back to its original high logical value. Since node 310 is recovered to its original high logical value, tristatable inverter, 326 , is no longer tristated. Instead tristatable inverter, 326 , actively drives node 320 to a low logical value.
[0027] Another example is, if the memory element has a logical one stored on it and transfer gates 304 and 306 are off, node 308 is a logical high value, node 310 is a logical high value, node 318 is a logical low value, and node 320 is a logical low value. In this example, if a soft error event disturbs node 318 from a logical low value to a logical high value, node 308 will remain a logical high value because PFET, MP 6 , is off and NFET, MN 6 is off, tristating tristatable inverter, 332 . Because tristatable inverter, 332 , is tristated, node 308 retains its original high value. Since node 308 is a logical high value, tristatable inverter, 316 , actively drives node 318 back to its original low logical value. Since node 318 is recovered to its original low logical value, tristatable inverter, 332 , is no longer tristated. Instead tristatable inverter, 332 , actively drives node 308 to a high logical value.
[0028] Another example is, if the memory element has a logical one stored on it and transfer gates 304 and 306 are off, node 308 is a logical high value, node 310 is a logical high value, node 318 is a logical low value, and node 320 is a logical low value. In this example, if a soft error event disturbs node 320 from a logical low value to a logical high value, node 310 will remain a logical high value because PFET, MP 8 , is off and NFET, MN 8 is off, tristating tristatable inverter, 338 . Because tristatable inverter, 338 , is tristated, node 310 retains its original high value. Since node 310 is a logical high value, tristatable inverter, 326 , actively drives node 320 back to its original low logical value. Since node 320 is recovered to its original low logical value, tristatable inverter, 338 , is no longer tristated. Instead tristatable inverter, 338 , actively drives node 310 to a high logical value.
[0029] If a soft error event disturbs a single node and a single node only in the memory element shown in FIG. 3 , the memory element will recover the single disturbed node back to its original logical value. These nodes include nodes 308 , 310 , 312 , 314 , 318 , 320 , 322 , 324 , 328 , 330 , 334 , and 336 .
[0030] The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art. | In a preferred embodiment, the invention provides a circuit and method for reducing soft error events in memory elements. A first transfer gate is connected to an first input of a first tristatable inverter, a second input of a second tristatable inverter, and the output of a third tristatable inverter. A second transfer gate is connected to an first input of the second tristatable inverter, a second input of the first tristatable inverter, and the output of a fourth tristatable inverter. The output of the first tristatable inverter is connected to the first input of the third tristatable inverter and the second input of the fourth tristatable inverter. The output of the second tristatable inverter is connected to the second input of the third tristatable inverter and the first input of the fourth tristatable inverter. The input of an inverter is connected to the output of the fourth tristatable inverter. | 6 |
[0001] This invention relates to a breast pump and, in particular, an electrically operated breast pump for drawing milk from a user.
BACKGROUND OF THE INVENTION
[0002] There are in existence a large number of electrically operated breast pumps, allowing a user, e.g. a mother, to pump milk from her breast. Various pumping mechanisms have been proposed for drawing milk from the mother's breast, including, for example, ones disclosed in U.S. Pat. Nos. 6,045,529 and 6,355,012 issued to Nüesch. Such mechanisms are generally speaking rather complicated, and thus costly to manufacture. In addition, most such mechanisms include gear trains which would generate much noise, especially when the motor is operating at a relatively high speed.
[0003] In addition, although a user may, with some existing breast pumps, be able to adjust the pumping cycles, e.g. by varying the number of suction cycles per minute, or adjusting the vacuum level for pumping milk from the user's breast, it is up to the user to decide whether to make such variation or adjustment, and the user may simply have no information on which to decide whether the current pumping rate is suitable or not. In this connection, U.S. Pat. No. 6,547,756 issued to Greter et al. discloses a programmable breast pump which may be programmed to generate a number of different milk expression (extraction) sequences, or curves. In this arrangement, a motorized pump is provided with a microprocessor-based controller. Cards, with microprocessor “chips”, containing instructions for different suction curves are also included, which may be inserted into the breast pump, so that the instructions in the cards may be read and acted upon by the breast pump. However, as in the case of other adjustable breast pumps discussed above, it is still up to a user to decide whether to change the mode of pumping operation of the breast pump, and a user may not know whether an alternative, and if so which, suction curve should be applied. A further shortcoming associated with conventional electric breast pumps is that the user is provided with no information as to the time required to fill up the milk receptacle, e.g. bottle.
[0004] Such and other shortcomings discussed above are also present in breast pumps disclosed in U.S. Pat. No. 6,673,036 issued to Britto and U.S. Pat. No. 6,090,065 issued to Giles.
[0005] It is thus an object of the present invention to provide an electric breast pump in which the aforesaid shortcomings are mitigated or at least to provide a useful alternative to the public.
SUMMARY OF THE INVENTION
[0006] According to a first aspect of the present invention, there is provided an electric breast pump including at least one hood member adapted to be fitted over a breast of a user; a chamber adapted to be in fluid communication with said hood member via a first valve; a first motor operatively associated with a pumping member which is movable to draw air from said hood member into said chamber via said first valve; said chamber having at least a first opening and a closure member operatively associated with said first motor, wherein said closure member is movable between a first position to close said first opening and a second position in which said first opening is open; and wherein said closure member is at said first position when said first motor is in operation and is at said second position when said first motor is not in operation.
[0007] According to a second aspect of the present invention, there is provided an electric breast pump including at least one hood member adapted to be fitted over a breast of a user; and at least a first sensing unit adapted to detect the passing of milk.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0009] FIG. 1 is a perspective view of an electric breast pump according to the present invention;
[0010] FIG. 2 is an exploded view of the breast pump shown in FIG. 1 ;
[0011] FIG. 3 is a sectional view of the breast pump shown in FIG. 1 ;
[0012] FIG. 4 is a sectional view taken along the line A-A in FIG. 3 ;
[0013] FIG. 5 is a circuit diagram of the breast pump shown in FIG. 1 ;
[0014] FIG. 6 shows part of the circuitry in the breast pump shown in FIG. 1 ;
[0015] FIG. 7 shows a liquid crystal display (LCD) setting in the breast pump shown in FIG. 1 ;
[0016] FIG. 8 is a block diagram of an exemplary microcontroller which may be used in the circuit shown in FIG. 5 ;
[0017] FIG. 9 is an enlarged view showing the engagement between the pump motor and the diaphragm in the breast pump shown in FIG. 1 ;
[0018] FIG. 10 is an enlarged sectional view of part of the breast pump shown in FIG. 3 ;
[0019] FIG. 11 is an enlarged perspective view showing the mechanism for manual adjustment of the level of vacuum in the breast pump shown in FIG. 1 ;
[0020] FIG. 12 shows a first configuration of the manual vacuum adjustment mechanism shown in FIG. 11 ;
[0021] FIG. 13 shows a second configuration of the manual vacuum adjustment mechanism shown in FIG. 11 ;
[0022] FIG. 14 shows an enlarged sectional view of the milk flow sensing mechanism in the breast pump shown in FIG. 1 ; and
[0023] FIG. 15 is a flow chart showing the steps of operation of the breast pump shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] FIGS. 1 and 2 show an electrically operated breast pump according to a preferred embodiment of the present invention, generally designated as 10 . The breast pump 10 has a hood 12 adapted to be fitted over a breast of a user in an essentially gas-tight manner, for pumping milk from the breast. An insert 12 a for contacting the user's breast is received within the hood 12 . The insert 12 a is made of a soft plastic material, e.g. silicone, to provide comfort to the user during use. The hood 12 is in funnel shape and has a tunnel 14 leading to a connector 16 , which fluidly communicates with the hood 12 , and with a milk-receiving bottle 18 via a valve seat 20 , the structure and function of which will be further discussed below.
[0025] The connector 16 is engaged with a head portion 22 which houses most of the operating components of the breast pump 10 , as will be clear from the ensuing discussion. On a top surface 24 of the head portion 22 is provided with an ON/OFF button 26 for selectively activating/deactivating the breast pump 10 . Also provided on the top surface 24 of the head portion 22 is a liquid crystal display (LCD) 28 for displaying various operation information and data relating to the operation of the breast pump 10 . The head portion 22 is connected with a handle 30 , which also acts as a battery compartment for housing a number of batteries 32 for powering the breast pump 10 . The handle 30 is swivellable relative to the head portion 22 for easy handling. On each side of the handle 30 is provided a PAUSE button 34 , allowing a user to temporarily suspend the operation of the breast pump 10 by pressing the button 34 once, and to resume its operation by pressing the button 34 once again. On a side of the head portion 22 is a power jack 36 which allows the breast pump 10 to be powered by an A/C source, possibly via a transformer (not shown).
[0026] FIG. 3 shows a sectional view of the breast pump 10 . As shown in FIG. 3 , provided in a chamber 37 of the connector 16 are two infrared (IR) units 38 a, 38 b, each including an IR transmitter and an IR receiver. Housed in the head portion 22 is a pump motor 42 for operating a pump diaphragm 44 for generating a low pressure (vacuum) in the breast pump 10 . Within the handle 30 is a valve motor 46 for operating a needle valve 48 . The valve 48 is pneumatically connected, e.g. via a hose (not shown), with a nozzle 50 which is in turn pneumatically connected with the milk-receiving bottle 18 .
[0027] Housed in the head portion 22 is a microcontroller 40 for controlling the operation of various electronic and electrical components of the breast pump 10 . As shown in FIG. 5 , the microcontrolller 40 is electrically connected with and controls the operation of the pump motor 42 , the valve motor 46 , and the LCD display 28 . The microcontroller 40 is also connected with and receives instructions and/or signals from the PAUSE buttons 34 and the IR units 38 a, 38 b. FIG. 6 shows in more detail a circuitry which controls the operation of the valve motor 46 , the pump motor 42 , and the IR units 38 a, 38 b, of which only one set 38 a is shown here.
[0028] FIG. 7 shows the setting of the LCD display 28 , and it can be seen that the LCD display 28 may display such information as the setting being used, the flow-rate (slow, medium, high), battery low, and the remaining time (in minutes) required for filling the bottle 18 .
[0029] A microcontroller 40 suitable for use in the breast pump 10 may be one traded by Sino Wealth Microelectronics Corporation Limited, of Hong Kong, under serial number SH6622A, although other similar microcontrollers may also be used. SH6622A is a 4-bit microcontroller, which integrates a 4-bit CPU core with SRAM, 4K program ROM, timer and I/O Port. FIG. 8 shows a block diagram of SH6622A. The CPU of SH6622A contains the following function blocks: Program Counter, Arithmetic Logic Unit (ALU), Carry Flag, Accumulator, Table Branch Register, Data Pointer (INX, DPH, DPM, and DPL), and Stack.
[0030] FIG. 9 shows an enlarged perspective view of the pump motor 42 , having an output spindle 51 engaged with an eccentric cam 52 which in turn carries a yoke 54 fixed with the pump diaphragm 44 . By way of such an arrangement, rotational movement of the output pin 51 is converted into linear reciprocal movement of the diaphragm 44 in the direction of the bi-directional arrow L-L.
[0031] As can be clearly seen in FIG. 10 , fixed to the output spindle 51 of the pump motor 42 is a linkage mechanism 58 comprising six links 60 linked with one another in a hexagonal ring-shaped structure. Each link 60 is swivellable relative to two adjacent links 60 to which it is pivotally hinged. Over the output spindle 51 is also provided with a spring 62 which biases an end pin 64 outwardly, which in turn acts on and biases a lid 66 away from a vent hole 68 . The diaphragm 44 is positioned in a chamber 71 which is closeable by the lid 66 , a first one-way valve 70 , and a second one-way valve 74 . The first one-way valve 70 only allows air to enter the chamber 71 from a conduit 72 , which is in turn in fluid communication with the hood 12 . The second one-way valve 74 only allows air to exit the chamber 71 .
[0032] When the motor 42 is not in operation, the linkage mechanism 58 will be biased by the spring 62 to assume the shape and configuration as shown in FIGS. 3 and 10 . During operation of the pump motor 42 , rotation of the output spindle 51 will bring about simultaneous and corresponding rotation of the linkage mechanism 58 , whereby the hexagonal ring-shaped structure 58 will “flatten” because of the centrifugal force generated by the rotation, thus retracting the end pin 64 against the outward biasing force of the spring 62 . The lid 66 will thus close the vent hole 68 . With the vent hole 68 closed by the lid 66 , linear reciprocal movement of the diaphragm 44 in the direction of the bi-directional arrow L-L will draw air from the hood 12 , through the conduit 72 and the first one-way valve 70 , into the chamber 71 , and push the air out through the second one-way valve 74 , thus generating a lower pressure (“vacuum”) in the hood 12 relative to the outside atmospheric pressure, and mimicking a sucking action of a baby on a mother's breast. The sucking/releasing cycle is completed by a releasing action when the motor 42 stops rotation. Upon stopping of the motor 42 , the linkage mechanism 58 will, under the biasing force of the spring 62 , resume the stable shape and configuration as shown in FIGS. 3 and 10 , whereupon the lid 66 will be pushed by the end pin 64 away from the vent hole 68 , to thereby open the vent hole 68 . When the vent hole 68 is opened, air will enter the vent hole 68 , and then back into the hood 12 , thus releasing the “vacuum” in the hood 12 .
[0033] To allow further versatility of the breast pump 10 , a manual pressure adjustment mechanism is provided, allowing the user to manually adjust the level of “vacuum” applied during operation of the breast pump 10 , to suit individual need in different times. As shown in FIG. 11 , the manual pressure adjustment mechanism includes a wheel 80 with a gear 82 in mesh with a pinion 84 on an end of a pin 86 and a valve seat 88 . As can be seen in FIGS. 10, 12 and 13 , the wheel 80 is fixed to the handle 30 for rotational movement. The wheel 80 may be moved by a thumb of a user to rotate relative to the handle 30 , about the longitudinal axis of the wheel 80 . The valve seat 88 is also fixedly secured to the handle 30 . By way of such an arrangement, and because of the engagement between the gear 82 and the pinion 84 , rotation of the wheel 80 will cause the pin 86 to move in or out of a recess 90 in the valve seat 88 . In particular, rotation of the wheel 80 in the direction indicated by the arrow F in FIG. 12 will retrieve the pin 86 from the recess 90 , whereas rotation of the wheel 80 in the direction indicated by the arrow R in FIG. 13 will insert the pin 86 further into the recess 90 .
[0034] The valve seat 88 is made of a thermoplastic elastomer (TPE) or silicone, and when the pin 86 is fully received within the recess 90 , the valve seat 88 is fully sealed, whereas air may enter the valve seat 88 if the pin 86 is retrieved from the valve seat 88 , and the amount of air allowed to enter the valve seat 88 will depend on the extent to which the pin 86 is retrieved from the valve seat 88 . The recess 90 is in fluid communication with a nozzle 92 , which is in turn in fluid communication with the hood 12 , e.g. via a hose (not shown) connected to the conduit 72 , so that the pressure within the hood 12 when such is applied over a breast of a user may be fine-tuned by the user by manually operating the wheel 80 .
[0035] When the breast pump 10 is fitted over a breast of a user and the pump motor 42 is activated, the pump diaphragm 44 will reciprocate to generate a lower pressure (“vacuum”) in the hood 12 , thus stimulating milk ejection reflex and subsequent expression of milk. Milk from the breast of the user will flow into the hood 12 and subsequently into the chamber 37 in the direction of the arrow M. The milk will accumulate in the chamber 37 , first blocking the transmission of infrared signals between the transmitter and receiver of the lower IR unit 38 a, and subsequently that between the transmitter and receiver of the upper IR unit 38 b.
[0036] In the valve seat 20 is a one-way valve 96 which allows milk to enter the bottle 18 , but not vice versa. Because the hood 12 is at a lower pressure than the bottle 18 during operation of the pumping action of the diaphragm 44 , the higher pressure in the bottle 18 will prevent the milk in the chamber 37 from entering the bottle 18 , thus allowing the milk level to rise in the chamber 37 . It may take several sucking/releasing cycles before the milk level rises to, and blocks the transmission of infrared signals between the transmitter and receiver of, the upper IR unit 38 b. When the milk level rises to the upper IR unit 38 b, the motor 42 will stop, thus releasing the “vacuum” in the hood 12 , in the manner discussed above. In addition, the needle valve 48 will be opened by the valve motor 46 , whereby air will exit the bottle 18 via the nozzle 50 , and subsequently out of the needle valve 48 . The milk in the chamber 37 will thus fall, on its own weight, through the one-way valve 96 into the bottle 18 , during the course of which the level of milk in the chamber 37 will fall. The transmission of IR signals between the transmitter and receiver of the upper IR unit 38 b will thus resume, and then that between the transmitter and receiver of the lower IR unit 38 a will resume.
[0037] As shown clearly in FIGS. 4 and 14 , above the upper IR unit 38 b is a partition 98 which prevents milk from entering the interior of the head portion 22 , e.g. when the breast pump 10 is accidentally knocked over. Milk entering the interior of the head portion 22 may damage the movement parts of the breast pump 10 , thus shortening its useful life, or necessitating servicing.
[0038] Researches indicate that a baby's feeding is not a single continuous process, but rather a two-phased process in which the baby will initially suckle rapidly, called “stimulation”. Once the breast has been sufficiently stimulated, milk begins flowing and the baby will settle into a slower, more relaxed sucking speed for the actual feeding phase, called “expression”. The breast pump 10 can mimic the natural feeding pattern of a baby by first exhibiting rapid sucking/releasing actions to stimulate the milk ejection reflex (MER) or “let down”. Once milk begins to flow, the breast pump 10 will then exhibit slower and longer sucking/releasing actions which help to maximize milk flow in less time.
[0039] The manner of operation of the breast pump 10 will be further discussed by reference to FIG. 15 , which shows a flow,v chart of the steps of operation of the breast pump 10 . Once the breast pump 10 is started (Step 100 ), the valve motor 46 will be triggered once to close the needle valve 48 , which is called “retainer valve” in FIG. 15 (Step 102 ). A “let down” sequence will be operated in which sucking/releasing actions will be carried out at a speed of 90 cycles per minute at a pressure of 5-7 inch mercury (in Hg) for 30 seconds (Step 104 ). If no milk flows (Step 106 ), an “expression” mode will be operated in which sucking/releasing actions will be carried out at a speed of 45 cycles per minute at a pressure of 7-9 in Hg for 30 seconds (Step 108 ). If there is still no milk flow (Step 110 ), the microcontroller 40 of the breast pump 10 (hereinafter simply referred to as the “breast pump 10 ” for simplicity) will determine if this is the first time such occurs since the breast pump 10 is started (Step 112 ). If not, the breast pump 10 will repeat the above process (Step 114 ) by carrying out the “let down” sequence again (Step 104 ). If, however, such a situation has already occurred once in this operation, a sign or symbol alerting the user to seek medical assistance, e.g. to undergo certain milk flow stimulation operation, will be displayed on the LCD display 28 (Step 115 ), and the breast pump 10 will also cease operation immediately (Step 116 ). For carrying out sucking/releasing actions at a frequency of 45 cycles per minute, the pump motor 42 may be activated for 0.8 second, then deactivated for 0.53 second, and then activated for 0.8 second, and so on.
[0040] If milk flows after the “let down” sequence (Step 104 ) or the “expression” sequence (Step 110 ), the breast pump 10 will then check whether transmission of IR signals in the lower IR unit 38 a is interrupted (Step 118 ). If so, a timer in the microcontroller 40 will start timing (Step 120 ). The breast pump 10 will then check whether transmission of IR signals in the upper IR unit 38 b is interrupted (Step 122 ). If so, the timer will stop (Step 124 ). Because the volume in the chamber 37 between the lower IR unit 38 a and the upper IR unit 38 b is known, it is possible to thus calculate the rate of flow of milk (in grams per second, g/s) and such is calculated. The valve motor 46 will be triggered once to open the needle valve 48 , thus allowing milk in the chamber 37 to fall into the bottle 18 . The breast pump 10 will also count the number of times of such triggers of the valve motor 46 as “X” (Step 126 ).
[0041] The breast pump 10 will then check whether transmission of IR signals in the lower IR unit 38 a resumes (“released”) within 2.5 seconds (Step 128 ). If so, the valve motor 46 will be triggered once to close the needle valve 48 (Step 130 ). If transmission of IR signals in the lowver IR unit 38 a does not resume (“released”) within 2.5 seconds (Step 128 ), or after the closing of the needle valve 48 (Step 130 ), the breast pump 10 will then check if transmission of IR signals in the upper IR unit 38 b is still blocked in 2.5 seconds (Step 132 ). If so, the pump motor 42 will stop operation, and the needle valve 48 will be opened once again (Step 134 ). If transmission of IR signals in the upper IR unit 38 b is still blocked (Step 136 ), the pump motor 42 will stop operation again, and the needle valve 48 will be opened once again (Step 138 ). If transmission of IR signals in the upper IR unit 38 b is still blocked (Step 140 ), the pump motor 42 will stop, a warning signal will be given on the LCD display 28 , and the LCD display 28 will be turned off automatically in 5 minutes, (Step 142 ), and the operation of the breast pump 10 will also stop automatically (Step 116 ). Such will prevent the motor 42 from continuing operation when, e.g. the breast pump 10 accidentally topples over.
[0042] If transmission of IR signals in the upper IR unit 38 b is not blocked after Step 132 , Step 136 or Step 140 , the breast pump 10 will operate according to the milk flow rate obtained in Step 126 . If the flow rate is between 0.01 to 0.09 g/s (Step 144 ), the breast pump 10 will switch to “let down” sequence (Step 146 ) in which sucking/releasing action is carried out at a frequency of 90 cycles per minute at a pressure of 5-7 in Hg, and a sign or symbol indicating low flow rate will be displayed on the LCD display 28 (Step 148 ). If the flow rate is between 0.1 to 0.24 g/s (Step 150 ), the breast pump 10 will carry out sucking/releasing action at a frequency of 45 cycles per minute at a pressure of 7-9 in Hg (Step 152 ), and a sign or symbol indicating medium flow rate will be displayed on the LCD display 28 (Step 154 ). If the flow rate is 0.25 g/s or above (Step 156 ), the breast pump 10 will carry out sucking/releasing action at a frequency of 38 cycles per minute at a pressure of 6-8 in Hg (Step 158 ), and a sign or symbol indicating high flow rate will be displayed on the LCD display 28 (Step 160 ). According to the present example, the bottle 18 is designed to hold 151.51 g of milk, and in each cycle, the milk that enters, and is thus collected by, the bottle 18 is 1.5 g. Based on such information, and the frequency at which sucking/releasing action is carried out, the breast pump 10 is able to calculate and display the remaining time required to fill the bottle 18 . In this example, it normally requires 101 triggers of the valve motor 46 , “X”, to fill the bottle 18 . Depending on the number of times, “X”, the valve motor 46 has already been triggered to open the needle valve 48 , the breast pump 10 can calculate the remaining time required for filling up the bottle 18 (Step 162 ). The remaining time required will be displayed on the TCD display 28 (Step 164 ).
[0043] If 1.5X>151.51 (Step 166 ), it means that the bottle 18 is filled up, the breast pump 10 will stop (Step 116 ). If not, the breast pump 10 will check again if transmission of IR signals in the lower IR unit 38 a is interrupted (Step 118 ), and the pumping action will go on again.
[0044] It should be understood that the above only illustrates an example whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention. For example, although the present invention is here described in the context of a “one-pump” model, it is equally applicable to a “two-pump” model, in which a second breast pump is pneumatically connected with the first pump to share in the suction vacuum generated by the pump motor.
[0045] It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations. | An electric breast pump is disclosed as including a hood to be fitted over a breast of a user, a chamber in fluid communication with the hood member via a one-way valve, a pump motor operatively associated with a pump diaphragm movable to draw air from the hood into the chamber via the valve, in which the chamber has an opening and a lid which is operatively associated with the motor, in which the lid is movable between a first position to close the opening and a second position in which the opening is open, and in which the lid is at the first position when the motor is in operation and is at the second position when the motor is not in operation. The breast pump also includes sensors for detecting the passing of milk, and a microcontroller for calculating the rate of flow of milk on the basis of data received from the sensors. | 0 |
FIELD
Embodiments of the present invention may relate to radio frequency devices and/or radio frequency identification (RFID) tags.
BACKGROUND
Goods and other items may be tracked and identified using a radio frequency identification (RFID) system/device. The RFID system may include an RFID tag that is placed on the item (such as a product) to be tracked. The RFID tag may be a small transponder that can be read by an RFID reader (or interrogator). The RFID reader may include a transceiver and an antenna. The antenna may emit electromagnetic (EM) waves generated by the transceiver, which, when received by the RFID tag, activates the RFID tag. Once the RFID tag has been activated, the RFID tag may modify and reflect the waves back to the RFID reader, thereby identifying the item to which the RFID tag is attached or is otherwise associated with.
The RFID reader may be a hand held or stationary device that transmits a radio signal that may be intercepted by the RFID tag. When the RFID tag passes through the radio waves, the RFID tag detects the signal and is activated. Data encoded in the RFID tag may then be transmitted to the RFID reader for further processing. This type of system allows for quick and easy identification for a large number of items by simply passing them through the scope of an RFID reader. This type of system may also identify items on which the RFID tag is not exposed, such as items in which the tag is located internally. Further, the RFID reader may read multiple tags very quickly, such as items passing by the RFID reader while the items are on a conveyer belt, for example.
There are at least three basic types of RFID tags, namely a beam-powered RFID tag, a battery-powered RFID tag and an active RFID tag. The beam-powered RFID tag is a passive device that receives energy required for operation from the radio waves generated by the RFID reader. The beam-powered tag rectifies an EM field and creates a change in reflectivity of the field that is reflected to and read by the RFID reader. The battery-powered RFID tag may receive and reflect EM waves from the RFID reader. However, the battery-powered RFID tag may include a battery to power the RFID tag. Additionally, the active tag may actively transmit EM waves that are then received by the RFID reader.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and a better understanding of embodiments of the present invention may become apparent from the following detailed description of arrangements and example embodiments and the claims when read in connection with the accompanying drawings, all forming a part of the disclosure of this invention. While the foregoing and following written and illustrated disclosure focuses on disclosing arrangements and example embodiments of the invention, it should be clearly understood that the same is by way of illustration and example only and the invention is not limited thereto.
The following represents brief descriptions of the drawings in which like reference numerals represent like elements and wherein:
FIG. 1 shows an RFID system according to an example arrangement;
FIG. 2 shows an RFID system according to an example embodiment of the present invention;
FIG. 3 shows an RFID tag for use in an RFID system according to an example embodiment of the present invention;
FIG. 4 shows a product having an RFID tag according to an example embodiment of the present invention;
FIG. 5 is a flowchart showing operations of an RFID system according to an example embodiment of the present invention; and
FIG. 6 is a block diagram of a system according to an example embodiment of the present invention.
DETAILED DESCRIPTION
In the following detailed description, like reference numerals and characters may be used to designate identical, corresponding or similar components in differing figure drawings. Further, in the detailed description to follow, example sizes/models/values/ranges may be given although the present invention is not limited to the same. Where specific details are set forth in order to describe example embodiments of the invention, it should be apparent to one skilled in the art that the invention can be practiced without these specific details.
FIG. 1 shows an RFID system according to an example arrangement. Other arrangements are also possible. More specifically, FIG. 1 shows an RFID system 10 that includes an RFID reader 20 and an RFID tag 50 . While not shown, the RFID system 10 may also include a number of other RFID tags, which may be similar or different than the RFID tag 50 . The RFID reader 20 may transmit information via a wireless air interface 40 to the RFID tag 50 . The air interface 40 enables the RFID reader 20 to provide power, query data and/or timing information to the RFID tag 50 so that the RFID tag 50 may provide response data. Specifically, the RFID tag 50 may scavenge power from a received radio-frequency (RF) signal, and may backscatter the response data to the RFID reader 20 by modulating an impedance of an associated antenna. For example, in a half-duplex communications arrangement, the RFID reader 20 may modulate an RF waveform with information (e.g., bits). During a tag-to-reader transmission, the RFID reader 20 may transmit a Continuous-Wave (CW) radio signal. The RFID tag 50 may then backscatter-modulate the CW signal with bits to create a radio-frequency (RF) information waveform that is transmitted back to the RFID reader 20 .
The RFID reader 20 may include a memory 22 to store various algorithms and information, a core 24 (e.g., a controller or processor) to control operations of the RFID reader 20 , and a front end 26 , which is operatively coupled to an antenna 28 , to control the transmission of information via the air interface 40 and also to process backscatter information received via the air interface 40 by the antenna 28 .
The RFID reader 20 may be coupled (e.g., via a network 30 ) to a further processing system, such as a server 32 . This may allow for programming and/or control of the RFID reader 20 by the server 32 . Further, the RFID reader 20 may provide data, via the network 30 , to the server 32 for a variety of purposes. For example, multiple RFID readers 20 may be coupled to a processing system, such as the server 32 , so as to provide the server 32 with a comprehensive view of a particular environment. That is, multiple RFID readers 20 may be deployed at various locations within a warehouse. Each of the RFID readers 20 may be coupled via the network 30 (e.g., a wired and/or wireless network) to one of more servers 32 , so as to provide a warehouse operator with RFID access to multiple locations within the warehouse, and/or across multiple warehouses.
The RFID tag 50 may include an RFID circuit 60 (e.g., an RFID Integrated Circuit (IC)), and an antenna 80 to facilitate reception and transmission of radio-frequency signals via the air interface 40 . The RFID circuit 60 and the antenna 80 may be located on a base material or substrate (e.g., a plastic or paper material) to thereby constitute the RFID tag 50 . The RFID tag 50 may include a number of subcomponents, any one or more of which may be implemented on one or more integrated circuits that form part of the RFID tag 50 .
More specifically, FIG. 1 shows that the RFID circuit 60 includes a power conversion circuit 62 , a transmit/receive circuit 64 , and a memory 66 . As described in detail below, the RFID circuit 60 may also include a power source 68 . The RFID circuit 60 includes components to facilitate the processing of RF signals received via the antenna 80 and also to facilitate the transmission of an RF signal (e.g., a modulated backscatter signal) via the antenna 80 . The memory 66 may store a tag identifier, a product identifier, configuration values applicable to configuration of the RFID tag 50 , one or more algorithms, and/or other suitable information. As noted above, the RFID tag 50 may be a “passive” tag that scavenges power from an RF signal received via the air interface 40 . Alternatively, the RFID tag 50 may be an “active” tag and include the power source 68 to power the RFID tag 50 .
The air interface 40 may facilitate both full and half duplex communications, for example. Further, while arrangements and embodiments are described herein as utilizing RF signals to communicate, other forms of wireless communication across the air interface 40 may be utilized. For example, in various embodiments, coupling between the RFID reader 20 and the RFID tag 50 may be achieved utilizing inductive coupling, close coupling, or electrical coupling.
Embodiments of the present invention may include an RFID tag that includes at least an antenna, an auxiliary interface device and a dual-ported non-volatile memory device. The antenna may send and receive data across a wireless interface. The auxiliary interface device may couple with an apparatus external to the RFID tag, such as a server or computer. Additionally, the non-volatile memory device may include at least a first port associated with the antenna and a second port associated with the auxiliary interface device, such as input/output (I/O) pins. The auxiliary interface device may include a communication link to communicate data information to and from the memory device and a power link to provide power to the RFID tag. The RFID tag may communicate data over a wireless interface using the antenna or a wired interface through the auxiliary interface device.
FIG. 2 shows an RFID system according to an example embodiment of the present invention. Other embodiments and configurations are also within the scope of the present invention. More specifically, FIG. 2 shows an RFID tag 100 and a server component 200 that are coupled together by a wired interface 250 (such as a bus interface). In this context, the wired interface relates to a physical connection between two entities, such as by wires, cables, a bus, etc. Both the RFID tag 100 and the server component 200 may be provided together within one server chassis, for example. Alternatively, the server component 200 may be a server chassis and the RFID tag 100 may be coupled to the server component 200 either within the chassis or external to the chassis. Although not specifically shown in FIG. 2 , a RFID reader (such as the RFID reader 20 in FIG. 1 ) may also be considered as part of the RFID system. Such an RFID reader may send and receive signals via an air interface with an antenna 110 of the RFID tag 100 . As one example, the antenna 110 may be coupled to allow communication with an RFID reader located external to a server chassis.
The RFID tag 100 may include the antenna 110 , a power conversion circuit 120 , a transmit/receive circuit 130 , a memory device 140 and an auxiliary interface device 150 . The RFID tag 100 may also include a power supply adaptor 160 that is coupled to the auxiliary interface device 150 so as to obtain power for the RFID tag 100 when the RFID tag 100 is physically coupled to the server component 200 via the wired interface 250 . Other components and circuits may be provided on the RFID tag 100 but are not discussed herein for ease of illustration and discussion. The antenna 110 , the power conversion circuit 120 , the transmit/receive circuit 130 , the memory device 140 , the auxiliary interface device 150 and the power supply adaptor 160 may be provided on an RFID IC. While FIG. 2 separately shows power conversion circuit 120 and power supply adaptor 160 , both features may be provided as one component. The same may also apply to other features in the figures.
As shown, the memory device 140 may be a dual-ported memory device that includes a non-volatile memory 142 and a dual-ported multiplexer 145 (or memory controller). As one example, the memory 142 may be a random access memory (RAM). Thus, the memory device 140 may be referred to as a dual-port non-volatile random access memory device and/or a dual-port non-volatile random access memory. Although the above example describes a particular type of memory device, the methods and apparatus described herein may use other suitable memory devices.
The power conversion circuit 120 may receive a signal from the antenna 110 and convert the signal into electric energy. The electric energy may be used to power the non-volatile memory 142 , for example, when needed. Stated differently, the power conversion circuit 120 may create direct current (DC) power from an external radio frequency signal. The transmit/receive circuit 130 may control operations of the RFID tag 100 . For example, the transmit/receive circuit 130 may receive signals from the antenna 110 and perform a conversion (e.g., analog to digital) of the signals. These signals may be provided on a link 135 to access data in the memory device 140 (i.e., in the memory 142 ).
The memory device 140 may include at least two ports and thus may be considered a dual-port non-volatile memory device. Other numbers of ports greater than one may also be provided as part of the memory device 140 . Thus, the memory device 140 may include the dual-ported multiplexer 145 (or memory controller) that receives signals along the link 135 (from the transmit/receive circuit 130 ) and along a link 155 (from the auxiliary interface device 150 ). The dual-ported multiplexer 145 applies received signals to the memory 142 so as to access data. Likewise, the dual-ported multiplexer 145 may receive signals from the memory 142 and apply those signals along either the link 135 (to the transmit/receive circuit 130 ) or the link 155 (to the auxiliary interface device 150 ). A first port 141 of the memory device 140 may be used for accessing, sending and/or receiving data to/from the antenna 110 . Thus, the first port 141 of the memory device 140 may be associated with the antenna 110 for transmission/reception via the air interface. A second port 143 of the memory device 140 may be used for accessing, sending and/or receiving data to/from the server component 200 via the wired interface 250 . Thus, the second port 143 of the memory device 140 may be associated with the auxiliary interface device 150 for transmission/reception via the wired interface 250 .
The auxiliary interface device 150 may include and/or be coupled to a communication link 155 to send/receive data to/from the second port of the memory device 140 . The auxiliary interface device 150 may also include and/or be coupled to a power source link 157 to supply power to the power supply adaptor 160 , which may in turn supply power to components of the RFID tag 100 . The auxiliary interface device 150 therefore allows communication data to be communicated through the wired interface 250 in addition to data be communicated through the antenna 110 via the air interface. Additionally, the auxiliary interface device 150 allows the RFID tag 100 to be powered by the server component 200 (or other device coupled via the wired interface 250 ) in addition to receiving power over the air interface based on the signal received by the antenna 110 .
In at least one embodiment, the server component 200 may be coupled via the wired interface 250 with the RFID tag 100 to provide communication signals and/or power signals. The server component 200 may include an interface/adaptor device 210 to couple the wired interface 250 with a bus 220 such as a system management bus (SMBUS) of the server component 200 . Other circuits/devices 230 of the server component 200 are not discussed herein for ease of discussion. The wired interface 250 and the associated interface devices 150 and 210 may be any of a number of different configurations such as wires, cables, buses, etc. so as to communicate when properly attached and/or coupled to both the RFID tag 100 and the server component 200 (or other device or computer system). For example, the interface devices 150 and 210 and the wired interface 250 may be associated with I 2 C (Inter-IC) Bus, Serial Peripheral Interface (SPI), iWire, Memory Bus, etc.
The RFID tag 100 may be provided on or within a server chassis. That is, the onboard RFID tag 100 may be embedded at a board level within the server chassis and have antenna connectivity to outside the server chassis. The RFID tag 100 in such a configuration may provide specific information such as a server name, power up information (relating to sub-nets), etc.
The server (including the server component 200 ) may be coupled to a network interface adaptor 270 , which in turn may be coupled to a network 300 such as a local area network (LAN), metropolitan area network (MAN), and/or a wide area network (WAN), for example. Other types of wired and/or wireless networks may also be provided as the network 300 .
The wired interface 250 between the server component 200 and the RFID tag 100 allows the server component 200 to read from the memory device 140 when the RFID tag 100 is in a passive mode (and/or an active mode). That is, the server component 200 (located external to the RFID tag 100 ) may read data from the memory device 140 and across the auxiliary memory device 150 when the RFID tag 100 is in a passive mode or an active mode. Additionally, the wired interface 250 between the server component 200 and the RFID tag 100 also allows the server component 200 to write data to the memory device 140 when the RFID tag 100 is in a passive mode (and/or an active mode). That is, the memory device 140 may store (or write) data received from the auxiliary interface device 150 when the RFID tag 100 is in a passive mode.
FIG. 3 shows an RFID tag for use in an RFID system according to an example embodiment of the present invention. Other embodiments and configurations are also within the scope of the present invention. More specifically, FIG. 3 shows an RFID tag 100 ′. Although not specifically shown in FIG. 3 , the RFID tag 100 ′ may be coupled to other components such as the server component 200 shown in FIG. 2 along the wired interface 250 . The RFID tag 100 ′ includes several similar components as in the RFID tag 100 shown in FIG. 2 , and therefore these components will not be discussed again in detail.
The RFID tag 100 ′ may include a set of input/output (I/O) pins 170 as the auxiliary interface device. The I/O pins 170 may be coupled by a communication link 175 to a memory interface 180 . The memory interface 180 may be coupled to the memory device 140 by a communication link 185 so as to access locations within the memory 142 . The memory interface 180 (and the link 185 ) may also be considered as part of the memory device 140 . The memory interface 180 may generate signals (such as address signals, data signal, row and column address strobes, etc.) in order to access the specific locations within the memory 142 .
Additionally, the power supply adaptor 160 may be a combination of diodes that have output sides connected so as to provide current isolation, such that power sources can operate independently or simultaneously. The power source link 157 may therefore receive a positive voltage (i.e., +V) from the I/O pins 170 and from the power conversion circuit 120 , both being energized from a device/apparatus located external to the RFID tag 100 ′. While FIG. 3 separately shows power conversion circuit 120 and power supply adaptor 160 , both features may be provided as one component. The same may also apply to other features in the figures.
FIG. 4 shows a product having an RFID tag according to an example embodiment of the present invention. More specifically, FIG. 4 show a product 400 that includes an RFID tag 410 and a product component 430 coupled by a wired interface 420 . The product 400 may be any of numerous types of products, items, objects, etc. such as a server, a laptop computer, etc. The product 400 includes various components that allow the product to work such as various circuits, memories, processors, etc. As one example, FIG. 4 shows a processor 435 provided within the product component 430 such as a server component or computer component. In FIG. 4 , the RFID tag 410 may be provided on or within the product 400 and be coupled to the product component 430 so as to allow communication between the RFID tag 410 and the product component 430 . The RFID tag 410 may correspond with the RFID tag 100 shown in FIG. 2 and/or the RFID tag 100 ′ shown in FIG. 3 . The communication is enabled based on the wired interface 420 (or bus interface). The wired interface 420 may correspond with the wired interface 250 shown in FIG. 2 . In a similar manner as discussed above, the product component 430 may also be coupled to a network and/or system so as to provide communication of information to the network and/or system. Likewise as discussed above, an antenna 415 of the RFID tag 410 may also communicate with an RFID reader (not shown in FIG. 4 ) via an air interface.
FIG. 5 is a flowchart showing operations of an RFID system according to an example embodiment of the present invention. Other operations, orders of operations, flowcharts and embodiments are also within the scope of the present invention. More specifically, FIG. 5 shows that data may be communicated between an RFID tag (i.e., an RFID memory) and an RFID reader via an air interface in block 502 . The RFID tag may be coupled to a specific product (such as server or computer system) in block 504 . Power may be provided from the specific product via a wired interface in block 506 . Additionally, data may be communicated between the RFID tag (i.e., the RFID memory) and the specific product via the wired interface in block 508 . In block 510 , the data received at the specific product in block 508 may be communicated to a network/system for any of various reasons such a location determination, security, inventory, etc.
FIG. 6 is a block diagram of a system (such as a computer system 600 ) according to an example embodiment of the present invention. Other embodiments and configurations are also within the scope of the present invention. More specifically, the computer system 600 may include a processor 610 that may have many sub-blocks such as an arithmetic logic unit (ALU) 612 and an on-die (or internal) cache 614 . The processor 610 may also communicate to other levels of cache, such as external cache 620 . Higher memory hierarchy levels such as a system memory (or random access memory RAM) 630 may be accessed via a host bus 640 and a chip set 650 . The system memory 630 may also be accessed in other ways, such as directly from the processor 610 and/or without passing through the host bus 640 and/or the chip set 650 . The system 600 may further include flash memory 655 and/or a peripheral interface to receive the flash memory 655 . The flash memory 655 (and/or peripheral interface) may be coupled to the chipset 650 . In addition, other functional units such as a graphical interface 670 and a network interface 660 , to name just a few, may communicate with the processor 610 via appropriate busses or ports. The processor 610 may be powered by an external power supply 680 . The system may also include a wireless interface 690 coupled to the chipset 650 (or to the processor 610 ) to interface the system 600 with other systems, networks, and/or devices via a wireless connection. Additionally, the system 600 may also include a wired interface 695 . The wired interface 695 may be for communication with the RFID tag 700 .
Additionally, an RFID tag 700 may be coupled to the processor 610 by a wired interface 710 . The RFID tag 700 may correspond to the RFID tag 100 shown in FIG. 2 , the RFID tag 100 ′ shown in FIG. 3 and/or the RFID tag 410 shown in FIG. 4 . The wired interface 710 may correspond to the wired interface 250 shown in FIG. 2 and/or the wired interface 420 shown in FIG. 4 . Accordingly, the RFID tag 700 may be attached or plugged into the computer system 700 for various reasons such as location determination, security, inventory, etc.
Embodiments of the present invention may provide power-on and power-off RFID tag access. For example, embodiments of the present invention may provide power-on and power-off server location determination (or other component location determination). Additionally, various information may be updated on the RFID tag by using an auxiliary interface device and/or I/O pins. This allows the information stored on the RFID tag to be kept current and up-to-date. Additional security information may also be added to the RFID tag using the auxiliary interface device and/or the I/O pins.
Embodiments of the present invention may be applicable in numerous environments as will be discussed below merely as examples. Other embodiments, environments and applications are also within the scope of the present invention. Embodiments of the present invention may be provided within or as part of shipping containers. That is, a battery powered product may monitor conditions of the container. The RFID reader that reads the presence of the container may simultaneously (or substantially simultaneously) read out environmental history (e.g. temperature, shock, humidity, time of events, etc.) as well as other information stored at the origin of the shipping. Embodiments of the present invention may also be applicable to sensor network motes such as low or ultra low power sensors that make measurements and store the measured data with a periodicity in the RFID tag's non-volatile memory. The data may eventually be read and the memory may be cleared at that point.
Still further, embodiments of the present invention may also be applicable for security/authentication for wireless Universal Serial Bus (USB) applications. For example, embodiments of the present invention may include an RFID tag integrated into a peripheral to enable enhanced security. Key exchange and rotating authenticity codes may also enhance security.
Embodiments of the present invention may also be applicable to laptop wireless fidelity (WiFi) applications. More specifically, an RFID tag in a laptop in a briefcase may be powered down and carried through a security portal. The security portal may read both an employee's badge number and the laptop's RFID tag. The system may compare the RFID tag's serial number to its active computer database and if it is enabled, then write a Wired Equivalent Privacy (WEP) decryption key to the tag's non-volatile memory. Thus, the next time the laptop is turned on, the laptop may have access to specific sites based on the portals in which the tag has passed.
Systems represented by the various foregoing figures can be of any type. Examples of represented systems include computers (e.g., desktops, laptops, handhelds, servers, tablets, web appliances, routers, etc.), wireless communications devices (e.g., cellular phones, cordless phones, pagers, personal digital assistants, etc.), computer-related peripherals (e.g., printers, scanners, monitors, etc.), entertainment devices (e.g., televisions, radios, stereos, tape and compact disc players, video cassette recorders, camcorders, digital cameras, MP3 (Motion Picture Experts Group, Audio Layer 3) players, video games, watches, etc.), and the like.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to affect such feature, structure, or characteristic in connection with other ones of the embodiments. Furthermore, for ease of understanding, certain method operations may have been delineated as separate operations; however, these separately delineated operations should not be construed as necessarily order dependent in their performance. That is, some operations may be able to be performed in an alternative ordering, simultaneously, etc.
Although embodiments of the present invention have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention. More particularly, reasonable variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the foregoing disclosure, the drawings and the appended claims without departing from the spirit of the invention. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. | Embodiments of a radio frequency identification tag are generally described herein. Other embodiments may be described and claimed. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to heading instruments in general and more particularly to a low cost instrument containing a visual display of heading for tanks.
The present low cost technique for providing heading information in tanks requires a magnetic sensor to initialize the system and a directional gyroscope for maintaining the alignment. In a system of this nature the visual read out of heading information is an indicator card mounted on the control panel which is servoed to a synchro on the directional gyroscope.
The primary disadvantage of this system is that it uses a magnetic sensor for alignment which can be affected by large iron or steel structures. In tanks for example, a turret would have to be in a fixed position during alignment in order to avoid degrading the accuracy of the system. Also the proximity of other armored vehicles at this time can introduce errors in the heading.
Another disadvantage of this system is that the components take up a considerable amount of space, something that is at a premium in tanks.
Some expensive devices have utilized a gyrocompassing function with the use of accelerometers and bubbles which in addition of increasing the cost have increased the overall complexity of the system.
It is an object of this invention to provide a low cost heading indicator which is insensitive to weak magnetic fields of ferrous structures proximate to the device.
It is another object of the invention to provide a low cost heading indicator that is smaller in volume than the presently used device.
Another object of the invention is to combine the functions of a gyrocompass and a directional gyro in a single device without the need for accelerometers or bubbles.
Another object of this invention is to provide a system that aligns itself to true North within 5 minutes, that is insensitive to magnetic anomalies and that can then be switched to a directional gyroscope mode to give heading indications.
It is another object of the invention to provide a low cost heading indicator with a direct gyro readout providing heading information.
SUMMARY OF THE INVENTION
These objects are attained in a low cost heading indicator which includes a single degree of freedom platform stabilized by a two degree of freedom gyroscope. A circuit is provided for initially utilizing the gyroscope in a gyrocompass mode thereby aligning the gyroscope to true North and then selectively utilizing the gyroscope as a directional gyroscope. This result is obtained by coupling one of the sensivitive axes of the gyroscope through an amplifier to the corresponding torquer, and selectively through an amplifier to the opposite torquer. The other sensitive axis of the gyro is coupled through an amplifier to the platform torquer. A 45 degree conically shaped compass card is mounted on top of the case of the gyroscope to provide direct gyro readout of heading information. The device uses the gyro rate capture current as a direct measure from North to drive the gyrocompass amplifier.
The advantages of the proposed system include its small size and the avoidance of magnetic devices or bubble sensor. Additionally, it is unnecessary to provide a servo mechanism to couple the gyroscope output to the readout device. The truncated conical compass card provides a heading display visable from either a horizontal or vertical position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective schematic view of the low cost heading indicator system of the present invention.
FIG. 2 is a functional block diagram of the system.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective schematic view of indicator to be used in a tank. The indicator comprises a base 6 which supports a single degree of freedom platform 10, which is rotatable about a vertical axis (azimuth). The platform 10 is stabilized by a two degree of freedom dry flexure suspended gyroscope 11. The gyroscope 11 is oriented so that its two sensitive axes lie along the azimuth axis 13 and an east axis 12. The gyroscope 11 is mounted on the platform 10 and includes a case attached to an azimuth gimbal 14. To indicate heading, the system includes a truncated 45 deg. conically shaped compass card 16 which is mounted directly on azimuth gimbal 14. The invention overcomes the need of servo mechanisms by directly mounting the compass card on the gimbal. The conical shape of the compass card provides a visual display of heading when viewed from either the side or the top of the unit.
The gyroscope 11 includes a flywheel, the case 15, and a motor. The case 15 is mounted on the platform 10 and the flywheel is suspended within the case suspension. The motor maintains the flywheel rotating at a predetermined rate.
The gyroscope 11 also includes an east pickoff 19 (see FIG. 2) for sensing the relative rotation of the case about the east axis, an east axis torquer 20 for restoring movement about the east axis 12, an azimuth axis pickoff 21 to sense the relative rotation about the azimuth axis 13, and an azimuth axis torquer 22 for movement about the azimuth axis.
An azimuth gimbal torquer 23 is provided to rotate platform 10 about the azimuth axis.
As shown in FIG. 2 the east axis pickoff 19 is coupled to the east axis torquer through a rate capture amplifier 24. The output of the rate capture amplifier 24 is provided to the azimuth axis torquer 22 through a gyrocompass amplifier 25. A mode relay 26 is disposed between the gyrocompass amplifier 25 and the azimuth axis torquer 22.
The azimuth axis pickoff 21 is coupled to the azimuth gimbal torquer 23 by means of an azimuth isolation amplifier 27 which causes the gimbal torquer to displace the gimbal to keep it aligned with the flywheel.
A clock and countdown circuitry 30 is connected to a pickoff excitation supply 31. The clock and countdown circuitry 30 includes a crystal oscillator clock which produces a DTL logic level square wave, and countdown logic which utilizes the clock input to produce a square wave for the input to the pick off excitation supply 31. The pickoff excitation supply 31 is an amplifier which utilizes the logic input to produce a stable sine wave with low distortion. This is achieved by combination of filtering and feedback. The sine wave excitation signal generated by the pick off excitation supply 31 is used to excite the east axis pickoff 19 and the azimuth axis pick off 21. The signal generated by the azimuth axis pickoff 21 is amplified by azimuth isolation amplifier 27, whose output drives the azimuth torquer 23. The azimuth isolation amplifier 27 contains a proportional gain channel and a parallel integral channel to achieve overall servo loop compensation with adequate gain and phase margin. The two signals are summed in an operational amplifier whose output drives an H bridge output circuit with the azimuth gimbal torquer 23 as the load, and a relay in series with the load is used to initially close the loop and also to open the loop when a BITE circuit 36 indicates a fault.
The BITE circuit 36 is a built in test equipment which basically checks the gimbal loop, which includes azimuth axis pickoff 21, azimuth isolation amplifier 27 and azimuth gimbal torquer 23; and the gyrocompass loop, which includes the east axis pick off 19, the east rate capture amplifier 24 the gyro compass amplifier 25 and the azimuth axis torquer 22. Once the initial system transients have been settled, the BITE circuits 36 are enabled. Normally both the gimbal loop and the gyrocompass loop are always at null, but if a large signal (approximately 10 volts DC) appears at either of these loop outputs for an extended time period (250 ms) the BITE circuit 36 issues a fault warning. In the case of a gimbal loop fault, the relay in series with the gimbal torquer is open.
The signal generated by the east axis pickoff is fed into the east rate capture amplifier 24 which in conventional fashion includes an AC pre-amplifier and a synchronous demodulator, coupled to the preamplifier to achieve quadrature rejection. Also included are operational amplifiers for integration and loop servo compensation. The next stage has a notch filter that uses an operational amplifier with resistor/capacitors in a parallel tee configuration to achieve high attenuation. The output stage of this loop is arranged as a current amplifier with feedback from a resistor in series with the east axis torquer 20. The loop gain is changed by shunting a load resistor in series with the east axis torquer 20.
The output from the east rate capture amplifier 24 is fed into a gyrocompass amplifier 25 through the mode relay 26. The gyrocompass amplifier feeds a power summing amplifier in a current feedback configuration in the gyrocompass mode. In the directional gyro mode the main input of the summing amplifiers is grounded while a correction signal of an azimuth gyro drift compensation may be fed into the summing amplifier input. Low drift operational amplifiers are utilized in this configuration to achieve the desired system accuracy. The output of the gyrocompass amplifier 25 is fed into the azimuth axis torquer 22 which is utilized to drive the flywheel about the azimuth axis. The output of the gyrocompass amplifier 25 is also coupled to BITE circuit 36 with which checks the signal in the same way as it checked the output of the azimuth isolation amplifier 27 above.
The clock and countdown circuitry 30 is connected to a gyro wheel supply 45 which counts down the logic signal from the clock and countdown circuitry 30 to produce an input to a logic countdown, that in turn produces 4 phases for the input signal to the gyro wheel supply. The gryro wheel supply 45 contains two transition H bridges that are driven by the gyro wheel supply input logic signals. The gyro wheel supply is coupled to the gyro motor. Each phase winding of the gyro motor is the load for the pair of H bridges. The excitation for the bridges is a single ended DC voltage. The input logic has frequency detection circuitry to detect loss of signal and prevent the possibility of damaging the motor.
The clock and countdown circuitry 30 provides a slip sync signal of which is used as the input signal to a sequencer 50. The sequencer utilizes the logic frequency to develop the following approximate times from additional countdown logic circuitry and relay drivers. T0=0, T1=30 seconds, T2=31 seconds, T3=300 seconds. At T0 the switch 52 is closed, activating the clock and countdown circuitry 30 and also energizing the gyroscope 11. The T1 timing signal turns on a capture loop relay 51 that closes the east rate capture loop, which includes the east pick off 19, the east rate capture amplifier 24 and the each torquer 20; and the gimbal isolation loop described above. At T2 the gyrocompass loop is closed by energizing the mode relay 26. At T3 the mode relay 26 is deenergized to open the gyrocompass loop and the BITE circuit is enabled. Any fault condition that exists after the BITE is enabled will keep the malfunction lamp illuminated. A power supply 53 utilizes 28 volt DC battery voltage as an input and utilizes pulse width modulation to achieve regulation and efficiency.
The operation of the system described above can be better understood by an explanation of some general principles of gyroscope physics and an example of the operation of the different modes.
At any local latitude, λ, the earth's rotational velocity, W e , can be resolved into two components, a horizontal component (W H ) and a vertical component (W V ). The horizontal component of earth's rate lies in a plane which is perpendicular to local gravity. The vertical component of earth's rate lies in the same vertical plane as local gravity. This vertical plane is aligned in a north-south direction.
Consider the platform 10 with the azimuth gimbal 14 approximately vertical (FIG. 1). The two degrees of freedom gyro 11 is mounted on this gimbal 14. One axis of the gyro, the east axis, 12 is captured back on to itself through the east rate capture amplifier 24. The other axis, the azimuth axis 13, is captured to the platform 10 through the azimuth isolation amplifier 27.
The east rate capture amplifier 24 captures the flywheel to the case about the east axis 12. The azimuth isolation amplifier 27 captures the case to the flywheel about the azimuth axis 13.
Assuming that the base of the Heading Indicator is in a horizontal plane with the east axis at an initial value ψ IN from the East-West reference and the azimuth axis is vertical, then the heading reference system is not yet useful in providing a north reference since the east gyro axis is not aligned to its reference, namely East. The North reference is established through a gyrocompassing process which is defined to be complete when the east axis is orthogonal to earth's rate. This occurs when ψ is zero; that is when the east axis is East.
For the purposes of following the gyrocompasing process assume that the azimuth gimbal is initially positioned such that the east axis is ψ IN degrees from East, ψ≠0. In this position the east axis pickoff will sense a component of horizontal earth's rate.
(W.sub.H)(Sin ψ.sub.IN)
The gyro case will rotate about the east axis of the flywheel at this rate. The east rate capture amplifier 24 provides a signal to the east axis torquer 20 to move the flywheel so that it follows the case 15 and maintains the east axis pickoff 19 at zero.
A measure of the east gyro torquer signal is amplified and sent to the gyrocompass amplifier 25. The gyrocompass amplifier output signal is applied to the azimuth axis torquer 22 which displaces the flywheel with respect to the case about the azimuth axis 13. The azimuth axis pickoff 21 provides an electrical signal indicating a relative motion between the flywheel and the gimbal 14. The signal is processed through the azimuth isolation amplifier 27 and drives the azimuth gimbal torquer 23 so that the gimbal 14 follows the flywheel and maintains the azimuth axis pickoff 21 at zero. The direction that the azimuth gimbal rotates is such to reduce the value of ψ.
This process continues until east gyro pickoff 17 senses no component of horizontal earth's rate; that is ψ=0 which usually takes about 5 min. The system has then finished gyrocompassing.
After gyrocompassing is finished the system switches to the directional gyro (DG) mode. This is done by opening the loop between the east rate capture amplifier 24 and the azimuth axis torquer 22 with mode relay 26, and can be accomplished manually or with a sequencer.
The purpose of the DG mode is to maintain the alignment that was achieved during gyrocompassing while the vehicle is travelling. This is accomplished through the east rate capture amplifier 24 and the azimuth isolation amplifier 27 electronics previously described. The east rate capture amplifier 24 keeps the flywheel from being disturbed, by torquing the flywheel so that it can follow the gimbal under all types of base motion that the vehicle will impose on the system. The azimuth axis 13 maintains the North alignment. Any vehicle motion about azimuth that may disturb the gimbal is sensed by the azimuth axis pickoff 21. The aximuth axis pickoff 21 provides a signal to the azimuth gimbal torquer 23 which keeps the gimbal 14 captured to flywheel which is fixed in space providing the North reference. | A heading indicator is disclosed which utilizes a one degree of freedom platform stabilized by a two degree of freedom dry flexure gyro. The output of one of the sensitive axis is coupled through an amplifier to the corresponding torquer in the gyro and selectively through an another amplifier to the opposite torquer. The other sensitive axis output is coupled through an amplifier to the platform. The indicator initializes at true north and is then switched to a directional gyro mode. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to an upper decorative stitching device to be provided mainly on a flat seam stitching machine. Its object is to make it possible to convey precisely the swing movements of the first lever which shows swing movements widthwise in a pendulum style to the horizontal reciprocating motion of the second lever provided with a spreader, to make it possible to reduce the cost of the device by simplifying the structure of the upper decorative stitching device, and also to facilitate the switching operation between the case of the upper decorative stitching and the case of the flat seam stitching.
As an upper decorative stitching device having a first lever which shows swing movements widthwise in a pendulum style in front of the sewing machine by a swing width cam provided on an upper shaft and a second lever having a spreader at the front end which also reciprocates horizontally with the other end of the connecting rod connected to the lower end of the first lever, there is known for example a patent document by the present applicant, i.e. Japanese Patent Publication Number 10-137474. As the upper decorative stitching device is made to connect the spot between the first lever which shows swing movements widthwise in a pendulum style in front of the sewing machine and the second lever which reciprocates horizontally along the needle position with a plate form connecting rod, there were movements up and down caused by the connecting rod at one end and the other end of the swinging step of the first lever, thereby making it difficult to reflect the swing motion of the first lever accurately on the movements of the second lever which should reciprocate horizontally. Moreover, as the upper decorative stitching device is made to change the stitching mode between the upper decorative stitching and the other stitching, e.g., flat seam stitching, by the switching operation of the clutch provided between the upper shaft and the swing width cam, machine construction is complicated which results in elevation of cost.
It is therefore an object of the present invention to provide an upper decorative stitching device capable of precisely conveying the swing movements of the first lever which shows swing movements widthwise in pendulum style to the horizontal reciprocating motion of the second lever, thereby simplifying the structure to obtain cost reduction, and also to make the switching operation between the upper decorative stitching and the flat seam stitching easier.
SUMMARY OF THE INVENTION
To solve the object as described above, the present invention provides an upper decorative stitching device designed to convert the rotation of the upper shaft into the reciprocal movements of the spreader by connecting the spot between the first lever which shows swing movements widthwise in a pendulum style in front of the sewing machine and the second lever which reciprocates horizontally along the needle position with a connecting rod having spherical bearings at both ends by bringing a follower into contact with the swing width cam provided on the upper shaft.
The second feature of the invention is to provide an upper decorative stitching device having a simple structure which permits easier changeover of the stitching mode between the upper decorative stitching and the other mode, e.g., flat seam stitching, by making it possible for a thread guide supporting member having at the lower end a thread guide for feeding upper decorative thread to the spreader to be switched over between the thread feeding position and the non-feeding position.
The third feature of the invention is that the thread guide supporting member is fixed to the front end of the mounting shaft whose front and rear ends are borne by the frame having a second lever, and is forced by coil springs whose front and rear ends are borne by the thread guide cam and the bearings, and, mediated by engagement between a plurality of the recesses and projections disposed on the opposed surfaces of the thread guide cam and the frame, in an ordinary time the thread guide supporting member shall be held perpendicularly to the thread feeding position, and when no upper decorative stitching thread is fed it shall be obviated nearly horizontally to the front right side of the sewing machine and held in a non-feeding position, then engaging the thread guide supporting member displaced to the non-feeding position with the first lever by way of engagement between the recesses and the projections, and separating the first lever from the swing width cam by engaging the thread guide supporting member displaced to the non-feeding position with the first lever to stop the operation of the spreader, thereby expecting to make the changeover operation more rapid and to obtain stability at the changeover position.
The upper decorative stitching device of the present invention is constituted so that the rotation of the upper shaft is precisely converted into the reciprocal movements of the spreader by means of a connecting rod having spherical bearings at both ends between a first lever which shows swing movements widthwise in front of the sewing machine by bringing a follower into contact with a swing width cam provided on an upper shaft and a second lever provided at its front end with a spreader which horizontally reciprocates along the needle position.
A thread guide supporting member having at its lower end a thread guide for feeding an upper decorative stitching thread to a spreader is provided so as to make it possible to be switched over between the thread feeding position and the non-feeding position.
A thread guide supporting member is fixed to the front end of the mounting shaft whose front and rear ends are borne by the frame having the second lever, and is forced by coil springs whose front and rear ends are borne by the thread guide cam and the bearings, and, mediated by engagement between the recess and the projection disposed on the opposed surfaces of the thread guide cam and the frame, in ordinary time the thread guide supporting member shall be held perpendicularly to the thread feeding position, and when upper decorative stitching thread is not fed it shall be obviated nearly horizontally to the front right side of the sewing machine and held in a non-feeding position, and then the thread guide supporting member displaced to the non-feeding position is engaged with the first lever, and the first lever is separated from the swing width cam to stop the operation of the spreader.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cutaway front view of the upper decorative stitching device according to the present invention.
FIG. 2 is a partial cutaway side view of the device.
FIG. 3 is a partial cutaway plan view showing mainly the driving portion of the spreader.
DETAILED DESCRIPTION OF THE INVENTION
Next, explanation will be given of embodiments of the present invention in accordance with the accompanying drawings.
FIG. 1 is a partial cutaway front view of the upper decorative stitching device according to the present invention, FIG. 2 is a partial cutaway side view of the device, and FIG. 3 is a partial cutaway plan view showing mainly the driving portion of the spreader.
In the drawings showing the embodiments, reference numeral 1 designates an upper shaft which repeats reciprocal semi-rotation along with the driving of the sewing machine, a swing width cam 2 is fixed to the upper shaft 1 , a first lever 3 which moves in a swinging motion widthwise in front of the sewing machine along with the rotation of the upper shaft 1 , a frame 6 is formed on the right side in the illustration rearward of the elevating position of the needle bar 7 , a bell crank type second lever 8 , borne on the reverse surface of the frame 6 , is provided in a freely swinging manner in a horizontal direction, and a connecting rod 9 is a means of connecting the lower end part 3 ′ of the first lever 3 with the one side arm 8 ′ of the second lever 8 to convert the swinging movement of the first lever 3 into the horizontal reciprocal movement.
The connecting rod 9 connects the lower end part 3 ′ of the first lever 3 with the one side arm 81 of the second lever 8 mediated by the spherical bearings 10 , 11 provided at both ends, by which it converts the swinging movements of the lower end part 31 of the first lever 3 into the horizontal reciprocal movement of the second lever 8 as precisely as possible. The reference mark (a) in FIG. 3 denotes a stroke of the connecting rod 9 .
The reference numeral 12 denotes a spreader provided with its base end part fixed to the front end of the other arm 8 ″ (left-hand in the figure) of the second lever 8 . The spreader 12 is angled downwardly as shown in FIG. 2 , so as to reciprocate along the outside of the needle position 13 as shown in FIG. 3 .
A thread guide 14 provided at the right side in front of the needle position 13 , is provided at the lower end of the thread guide supporting member 17 which is fixed to the front end of the mounting shaft 16 whose front and rear parts are borne by the bearing 15 which is erected on the frame 6 , and, biased by a coil type spring 19 which is set between the thread guide cam 18 fixed to the mounting shaft 16 and the operator side bearing 15 , it is placed at an ordinary time in a feeding position of upper decorative thread (solid line position in illustration).
On the confronting surfaces between the rear end part of the thread guide cam 18 (left side in FIG. 2 ) and the frame 6 , there are provided a recess 20 which continues for about 90 degrees along the rotation direction on the thread guide cam 18 side and a projection 21 provided on the frame 6 in a position corresponding to the recess 20 , and, by engagement between the recess 20 and the projection 21 , the thread guide supporting member 17 is held in a perpendicular state at an end of the recess 20 in order to hold the thread guide 14 in a feeding position of the upper decorative thread.
In the case of the flat stitch and the over-lock stitch in which no upper decorative stitch thread is fed, when a rotary operation is made by 90 degrees in the arrow marked direction in FIG. 1 with a switching operation knob 22 provided on the lateral side of the thread guide supporting member 17 , the projection 21 on the frame 6 side is engaged with the other end of the recess 20 on the thread guide cam 18 side to hold the thread guide 14 in the obviating position shown by the dashed line in the same figure.
Both side ends of the recess 20 are formed optionally in a deeper style, so that they can be engaged by the projection to stop in a manner of click motion. Needless to say, engagement and release between the recess 20 and the projection 21 are elastically performed against the bines of the spring 19 which forces the thread guide cam 18 and the thread guide supporting member 17 on the mounting shaft 16 .
As will be clear from the foregoing description, in this embodiment the switching means S of the thread guide 14 comprise the recess 20 on the thread guide cam 18 side, the projection 21 on the frame 6 side, the switching operation knob 22 on the lateral side of the thread guide supporting member 17 , and the spring 19 for biasing the thread guide cam 18 .
The thread guide supporting member 17 displaced to the obviating position in the manner as stated above causes the lateral side switching operation knob 22 to come into pressure contact with the lateral side of the first lever 3 , as shown in the dashed lines in FIG. 1 . By this pressure contact of the switching operation knob 22 , the first lever 3 is displaced beyond the range of swing motion to separate the engagement between the follower 4 and the swing width cam 2 as shown in FIG. 1 , whereby the connecting rod 9 and the second lever 8 are stopped from operating and driving of the spreader 12 is stopped.
Furthermore, when the thread guide supporting member 17 is reinstated to the position illustrated in solid line by operating the switching operation knob 22 , the follower 4 comes into contact with the swing width cam 2 by traction of the spring 5 to reinstate the device simply to the upper decorative stitching state.
In the drawings, the element indicated by the numeral 23 denotes a return spring of the second lever 8 , 24 denotes a thread guide, 25 denotes a fulcrum shaft of the first lever 3 positioned at the front upper part of the sewing machine, and 26 denotes a fulcrum shaft of the second lever 8 .
The upper decorative stitching device according to the present invention is highly useful in the case of partly changing over the sewing method in the course of sewing a piece of garment such as for example for upper decorative stitching a neck portion or a sleeve of a pajama, and flat stitching or over-lock stitching a bottom portion.
Needless to say, the fixing positions, respective sizes, etc. of the first lever, second lever, connecting rod for connecting the two levers and the spreader are not limited to the style of the disclosed embodiment but their designs may be optionally modified in line with the purport of the present invention.
DESCRIPTION OF THE NUMERALS USED
1 Upper shaft
2 Swing with cam
3 First lever ( 3 ′ denotes the lower end part)
4 Follower
5 Spring
6 Frame
7 Needle bar
8 Second lever ( 8 ′ depicts a one-side arm and 8 ″ the other side arm)
9 Connecting rod (‘a’ denotes a stroke of the connecting rod)
10 Spherical bearing
11 Spherical bearing
12 Spreader
13 Needle position
14 Thread guide
15 Bearing
16 Mounting shaft
17 Thread guide supporting member
18 Thread guide cam
19 Spring
20 Recess
21 Projection
22 Knob for switching operation
S Switching means
23 Return spring for second lever
24 Thread guide
25 Fulcrum shaft for first lever
26 Fulcrum shaft for second lever | An upper decorative stitching device is designed to make it possible to precisely transmit the swing movement of a first lever which is capable of swing movements widthwise in a pendulum manner to horizontal reciprocating motion of a second lever, which is provided with a spreader. The device facilitates the operation of switching between an upper decorative stitching and no upper decorative stitching. A connecting rod ( 9 ) is provided at both ends with spherical bearings ( 10, 11 ) to provide a connection between the first lever ( 3 ) and the second lever ( 8 ), thereby converting the rotation of the upper shaft into the reciprocal movement of the spreader. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 12/643,846, filed Dec. 21, 2009, which claims the benefit of and priority to French Patent Application No. 0807148, filed Dec. 19, 2008. Both U.S. patent application No. 12/643,846 and French Patent Application No. 0807148 are hereby incorporated by reference in their entireties.
BACKGROUND
The present invention relates to “active implantable medical devices” as defined by the 20 Jun. 1990 Directive 90/385/EEC of the Council of European Communities, more specifically to devices that continuously monitor a patient's heart rhythm and deliver to the heart, if necessary, a resynchronization and/or a defibrillation electrical stimulation pulse, in response to an appropriate arrhythmia detected by the device. The present invention relates more particularly to techniques for safekeeping (i.e., protecting) these implantable devices (having generators and their associated sensors) when the patient is subjected to examination by magnetic resonance imaging (MRI).
The active implantable devices associated with the present invention typically include a housing, generally designated as a “generator”, that is electrically and mechanically connected to one or more leads. The leads are equipped with electrodes that are intended to come into contact with the patient's myocardium at those sites where the electrical potentials are detected (collected) and/or the stimulation pulses are delivered (applied). These electrodes can be endocardial electrodes (e.g., electrodes that are placed in a cavity of the myocardium in contact with the wall of the myocardium), epicardial electrodes (e.g., electrodes that are preferably used to define a reference potential, or to apply a shock stimulation pulse), or intravascular electrodes (e.g., electrodes that are introduced into the coronary sinus and advanced to a position that faces the myocardial wall of the left ventricle).
Heretofore, an MRI examination was contraindicated for patients having an implanted cardiac pacemaker or defibrillator. This is for several reasons, including, for example:
heating near the electrodes connecting the generator to the patient's heart; forces and torques of attraction exerted on the device immersed in high intensity magnetic fields generated by an MRI equipment; and unpredictable behavior of the device itself, due to exposure to extreme magnetic fields.
The problem of heating exists especially in the vicinity of leads equipped with electrodes that are connected to the generator. Indeed leads that are placed in an MRI imaging equipment behave like antennas and couple (collect) the radiofrequency (RF) energy emitted by the MRI imager. The frequency of the RF field is equal to the Larmor frequency of protons, f=42.56×B 0 , in Tesla, the characteristic static induction of the MRI imager. For typical static inductions B 0 of 1.5 T and 3 T, the RF frequencies correlatively generated by the MRI imager are approximately 64 MHz and 128 MHz respectively.
Indeed, the heating at the electrodes is proportional to the density of current flowing through them. Hence, the smaller the surface of the electrode, the higher the current density and the greater the heating of the surrounding tissues.
In practice, depending on the configuration of the generator, the leads, and the MRI imaging equipment, the temperature rise typically varies from 8° C. (for carbon electrodes) to 12° C. (for metal electrodes), and sometimes even up to 30° C.
The elevated temperature should not exceed 2° C. as specified in the EN 45502-1 standard and its derivatives. At a temperature increase of 4° C. or more, cell death can occur locally. This has as an immediate effect, among others, to irreversibly alter the characteristics of detection and stimulation of cardiac activity.
It is possible, as described in the U.S. Published Application 2007/0255332 A1, to provide a method for safekeeping a device from MRI in which any stimulus is inhibited, and a protection circuit at the connector housing to isolate the conductors of the generator circuits, and to connect all these conductors to the ground of the generator housing to prevent induced parasitic currents. But this procedure prevents the device from functioning for the duration of an MRI examination. An MRI examination can last several minutes, thus it is highly desirable that the device continues during the MRI examination period to provide seamless operation for detecting potential depolarizations at, and delivering stimulation pulses to, the myocardium. To achieve this, during the MRI examination, the device is switched to a protected mode of operation and disables circuits that are sensitive to high magnetic fields, such as RF telemetry circuits, and switching power supplies.
It is thus not sufficient, in practice, to simply disconnect all conductors of the lead and/or to connect them to ground for the duration of an MRI examination, in order to avoid induction of current flow.
To reduce the induced current flow in the lead conductors, it has been proposed to put a filter opposing the current flow in series with the conductors in the path of the induced currents. The filter may be a simple inductor, however, the attenuation of the induced currents is usually not sufficient. It also has been proposed to insert in the current loop an L-C type resonant circuit, tuned to the RF frequency generated by an MRI imager. But this solution has a drawback of requiring different types of filters depending on the RF characteristic frequencies of the MRI imager (e.g., 64 MHz, 128 MHz) because the RF characteristic frequencies vary from one device to another, as explained above.
SUMMARY
It is, therefore, an object of the present invention to solve the problem of heating near the electrodes connecting the generator to the patient's heart as might occur during an MRI examination.
The starting point of the present invention is the discovery by the inventors that one can seek protection of another nature: instead of limiting the current flow in the lead conductors, the present invention avoids, or at least reduces, the exposure of these conductors to RF induced magnetic fields generated by an MRI imager, by implementing a shielding technique that prevents or minimizes induction of RF currents in the conductors.
The use of shielded conductors in place of conductors of an implanted device would certainly be possible. However, it would require a new design of leads, and in any event would not apply to already implanted leads.
According to one embodiment, the present invention advantageously connects to leads of a bipolar type having at least two conductors: one connected to the distal electrode having a small surface in direct contact with the myocardium, the other connected to the most extended proximal electrode, which remains floating in the heart. This embodiment is further directed towards implementing during an MRI examination a particular configuration of sensing and stimulation of the myocardium, in which only the conductor connected to the distal electrode is functionally used for detection (or sensing)/stimulation, and the other conductor is maintained at the same potential as the metal housing of the generator that is electrically grounded to the device. In this configuration, one lead remains functional as a unipolar lead for the detection and stimulation operations, and the other conductor is temporarily used as a shielding conductor during the MRI examination.
One aspect of the invention is directed to a generator for an active implantable medical device of the cardiac stimulation, resynchronization and/or defibrillation prosthetic type of the generic type disclosed by U.S. 2007/0255332 A1 cited above. Such a device comprises a generator coupled to a detection/stimulation lead wherein:
the lead comprises: at least two distal electrodes at a proximal connector; and at least two conductors extending along the length of the lead from its distal end to its proximal end to connect the electrodes to respective terminals of the lead connector. the generator comprises: a metal housing; an electronic detection/stimulation circuit integrated in the housing; a connector comprising connection terminals connected to the electronic circuit of detection/stimulation and capable of being coupled to respective terminals of the connector of the lead; and means for MRI safekeeping, able to place the circuit of the generator in a configuration that is protected against the deleterious effects of exposure of the lead to magnetic fields that may be encountered during an MRI Examination by magnetic resonance.
To that purpose, the means for MRI safekeeping of the generator characteristically includes a means to temporarily connect one of the terminals of the connector to the potential of the metal housing, and the other remaining terminal or terminals connected to the electronic detection/stimulation circuit.
In a preferred embodiment, the lead is of a coaxial type with an internal conductor connected to an axial distal electrode, and an external conductor connected to a proximal electrode. In this embodiment, the means for MRI safekeeping includes a means for temporarily setting to the potential of the metal housing the connection terminal that is coupled to the external conductor of the lead, and keeping connected to the electronic detection/stimulation circuit the terminal link that is coupled to the internal conductor of the lead.
In another embodiment, the lead is of a co-radial type comprising two separate external conductors connected to two respective electrodes. In this embodiment, the means for MRI safekeeping includes a means for temporarily setting to the potential of the metal housing the connection terminal that is coupled to one of the external conductors of the lead, and keeping connected to the electronic detection/stimulation circuit the terminal connection that is coupled to the other external conductor of the lead.
Another aspect of the present invention is directed to a method of protecting an active implantable medical device as above, this method comprising a step of safekeeping by temporarily connecting one of the generator connector terminals to the potential of the metal housing, and leaving the other terminal link or terminal links connected to the electronic detection/stimulation circuit.
The method advantageously comprises a detection of a magnetic field by the generator, with the safekeeping step being performed on detection of the magnetic field, preferably only on detection of the magnetic field, and more preferably only during the existence of the magnetic field. The method may provide for mandatory suspension of safekeeping after expiry of a predetermined period of time.
BRIEF DESCRIPTION OF THE FIGURES
Further features, characteristics, and advantages of the present invention will become apparent to a person of ordinary skill in the art from the following detailed description and preferred embodiments of the present invention, made with reference to the annexed drawings, in which like reference characters refer to like elements, and in which:
FIG. 1 is a sectional view of a coaxial lead implementing a first embodiment of the present invention; and
FIG. 2 is an exemplary diagram of a switching circuit of a generator, in accordance with an implementation of the present invention.
DETAILED DESCRIPTION
As regards its software aspects, the invention can be implemented by an appropriate programming of the controlling software of a known pacemaker, for example of the cardiac pacemaker, resynchronizer and/or defibrillator type, including circuits for the acquisition of a signal provided by endocardial leads and/or one or more implanted sensors. The adaptation of the known devices to implement the functions of the present invention is believed to be within the abilities of a person of ordinary skill in the art, and therefore will not be described in detail.
The invention may particularly be applied to implantable devices such as those of the Reply and Paradym families produced and marketed by Sorin CRM (formerly known as ELA Medical), Montrouge, France. These devices include programmable microprocessor circuitry to receive, format, and process electrical signals collected by electrodes implanted and deliver low energy pacing pulses to these electrodes. It is possible to transmit from a programmer to the device by telemetry software that will be stored in a memory of the device and executed to implement the functions of the present invention that will be described below, with reference to the drawings.
FIG. 1 illustrates an example of a lead 10 of the coaxial type. At its distal end 12 , the lead 10 has two electrodes including a distal electrode or “tip” 14 having a small surface (e.g., a few mm 2 ), and an annular proximal electrode or “ring” 16 having a larger surface (e.g., tens of mm 2 ). The distal electrode 14 is intended to come into direct contact with the myocardial tissue in an atrial or a ventricular cavity. The proximal electrode 16 is intended to be floating inside the heart chamber, interfacing with blood.
The distal electrode 14 is connected to an inner conductor 18 while the proximal electrode 16 is connected to an external conductor 20 wound on the periphery of the body of the lead 10 . These conductors 18 and 20 are isolated from each other and from the external environment by means of internal and external insulating sheaths, not shown. The inner conductor 18 is preferably a coiled conductor extending axially along the main axis 22 of the lead 10 , so as to leave open in the central part a space sufficient to form a central lumen in which, for example, a wire guide may be introduced during implantation. The conductors 18 and 20 lead to respective terminals 24 and 26 at the proximal end 28 of the lead 10 , these terminals being part of a connector (not shown) for mechanically and electrically coupling the lead 10 to a generator of the implanted device.
Essentially, the invention proposes to connect the external conductor 20 to the ground and keep it connected to the electric potential of the metal housing of the generator so that the conductor 20 acts as a shield for the internal conductor 18 along the length of the central part 30 of the lead 10 . This shield provides a protection similar to that obtained by a coaxial cable used for conducting electrical signals of low voltage.
In an alternative embodiment, the present invention applies to leads of a “co-radial” type, in which both conductors have their own isolation, and are spiralled side by side around the main axis 22 of the lead 10 . In this case, the shielding effect is obtained by the proximity of one conductor that is connected to the ground, relative to the other functional conductor that is ungrounded and connected to the distal electrode.
In either embodiment (coaxial or co-radial lead), even if the two conductors are arranged differently, they are always geometrically kept close to each other. In this respect, the one conductor that remains functionally connected to the distal electrode is protected by the other conductor connected to ground, and is used to detect cardiac spontaneous waves and deliver stimulation pulses. The shielding by the proximal conductor that is temporarily connected to the ground limits the antenna phenomenon of the lead when placed in an RF field of the MRI imager, therefore limiting induced current in the distal conductor to remain functional.
FIG. 2 shows a preferred embodiment of a switching circuit of the generator in accordance with the present invention.
It is noted that there is no need to modify the lead to implement the invention, because the switching is performed by the generator. This has the advantage, firstly, that no redesign of the lead is necessary and, secondly, that the invention can be applied to existing leads, already implanted, simply by a change of generator. The change of generator at its end of life is generally performed without a change of the lead.
The generator has a stage 32 with a ventricular sensing amplifier 34 and a ventricular pulse generator circuit of ventricular pacing 36 . According to one embodiment, the generator includes a similar atrial stage 38 , which is illustrated but not described in detail, insofar as the various switches are operated in the same way to result in the same configurations described below.
The detection/stimulation circuits 34 and 36 are connected to the distal electrode 14 and the proximal electrode 16 via respective conductors 18 and 20 that are connected to corresponding terminals 24 and 26 .
The terminals 24 and 26 are coupled to circuits 34 and 36 by the various switches M 1 , M 2 , T 1 , and ST. An OCD switch allows the discharge of a connection capacitor 42 after delivering a stimulation pulse (an aspect of a generic implanted medical device, thus not described in detail). A switch B 0 is provided to selectively connect the metal housing 40 of the generator to the electrical ground of the different electrical circuits integrated inside said metal housing 40 .
For a bipolar sensing configuration, the switches are configured as follows: B 0 closed, M 1 and M 2 open, T 1 closed, and ST open.
For a unipolar sensing configuration, the switches are configured as follows: B 0 closed, M 1 closed, and M 2 , T 1 and ST open.
For a bipolar stimulation configuration, stimulation pulses are delivered between the distal and proximal electrodes. The proximal electrode is connected to the ground and the electrical voltage of the housing 40 is floating. The switches are configured as follows: B 0 open, M 2 and ST closed during stimulation.
For a unipolar stimulation configuration, stimulation pulses are delivered between the distal electrode and the housing 40 . The voltage of the proximal electrode is floating and the housing 40 is connected to the ground. The switches are configured as follows: B 0 closed, M 2 open, and ST closed for the duration of the stimulation.
The invention proposes to modify the generator and its control software, adding a link—indicated by a thick line in FIG. 2 —between terminal 26 of the generator (connected to the proximal electrode 16 ) and the metal housing 40 of the generator. According to one embodiment, this connection is selectively closed by actuation of a switch SV for the ventricular stage. If there is an atrial detection/stimulation stage, the same connection is possible, with a corresponding switch SA.
The purpose of the switches SA and SV is to force to the ground potential the conductor of the proximal electrode 16 (atrial or ventricular) during an MRI examination.
The connection to the ground potential of one of the conductors of the lead is an unconventional operation because the generator normally manages only the unipolar or bipolar configurations of stimulation/detection described above.
According to a preferred embodiment, the switches SA and SV are one of the following types: an electronic relay, and a MEMS switch (and the like) that are controlled by logic gates, said logic gates being controlled by the generator software.
When the conditions for switching to a safekeeping mode are met, the generator software controls the switches of the generator, in accordance with the present invention, and connects the proximal atrial and ventricular conductors to the generator housing and to the electrical ground of said housing during an MRI examination.
According to one embodiment, the generator includes a magnetic field detector employing various techniques for magnetic field detection, for example, detection of core saturation by a coil, detection of magnetic field by a field effect transistor, measurement of a voltage collected by a telemetry antenna, to name a few. The detection techniques of an MRI type magnetic field may be combined with other criteria and implemented in a specific algorithm of the generator software.
According to one embodiment, the safekeeping mode is maintained as long as the relevant conditions are met, for example, as long as the device is subject to an MRI type magnetic field.
When the device is in the safekeeping operating mode, the switches are configured as follows: B 0 closed, M 1 closed, M 2 open, T 1 open, and SV closed except temporarily during the short duration of the stimulation in another cavity (see below for detail).
In the safekeeping mode, the configurations of stimulation and detection are hybrid configurations, that is intermediate between the classical unipolar and bipolar configurations. Indeed:
the stimulation is located on the distal electrode of the lead, referring to both the potential of the proximal electrode and to the housing connected to the ground; the signal detection is of the unipolar type, but with a very short dipole insofar as the ground is connected to the proximal electrode.
Preferably, to avoid coupling between the two ventricular and atrial chambers during a ventricular stimulation, the proximal electrode is not grounded (and vice versa).
As the phase of stimulation is very short (typically 1 ms for the electrical stimulation pulse, followed by 14 ms to discharge the output capacitor), the brief absence of shielding in the atrial stage during ventricular pacing (or vice versa) has no significant impact on the temperature rise of the electrodes, which is a physical phenomenon having a time constant that is large relative to the duration of the stimulation phase.
When the device leaves the safekeeping mode after an MRI examination or more particularly after the disappearance of the detected MRI RF magnetic field, the standard configuration of detection/stimulation (as described above) is restored. The end of the MRI examination period alternately can be based on, for example, a predetermined time period corresponding to a time that would be somewhat longer than a suitable time to complete an MRI examination.
It should be understood that the present invention is equally applicable to a generator that is designed to address a larger number of cardiac chambers, as with devices such as devices of “multisite” type used, for example, for ventricular or atrial cardiac resynchronization.
It should be understood, however, that the safekeeping configuration can not only be used for MRI, but also as a protection in a variety of other electromagnetic environments created by medical devices such as electric scalpels, electrical stimulation devices for transcutaneous nerve stimulation (TENS), as well as equipments of everyday life such as anti-theft gates, devices for monitoring electrical items (EAS), and the like. In addition, the safekeeping configuration can be implemented to avoid the consequences of induced voltages on the lead. For one example, the safekeeping mode can be used to reduce the induced voltage that, if not corrected, could adversely affect the pacing stimulation pulse, e.g., by removing or reducing the stimulation pulse. For another example, the safekeeping configuration can be used to avoid a parasitic stimulation that can be triggered by an induced voltage appearing on the lead.
A further embodiment of the present invention is directed to a generator for an active implantable medical device having a lead for one of a cardiac stimulation, a resynchronization and a defibrillation operation, said generator comprising:
a metal housing having a ground potential; an electronic circuit housed in said metal housing having a first generator connection terminal and a second generator connection terminal, wherein the first and second generator connection terminals respectively receive first and second conducting terminals of a lead; a plurality of switches, and a switch controller controlling the plurality of switches in a first mode of operation in which at least one of the first and second generator connection terminals is connected to said electronic circuit for sensing cardiac activity and delivering stimulation pulses, and a safekeeping mode of operation in which one of the first and second generator connection terminals is connected to the metal housing ground and the other of the first and second generator connection terminals is connected to the electric circuit for sensing cardiac activity and delivering stimulation pulses.
Preferably, the generator further comprises a magnetic field detector, wherein the switch controller places the electronic circuit in the safekeeping mode in response to a detected magnetic field. The detected magnetic field has a corresponding duration and the switch controller temporarily controls the switches to operate in the safekeeping mode for said duration. The generator preferably includes comprising an amplifier and a pulse generator for respectively sensing cardiac activity and delivering stimulation pulses as needed.
In a preferred embodiment the generator has a first mode of operation that is a bipolar sensing mode in which the metal housing is grounded and the first and second generator connection terminals are connected to the amplifier. The generator also has a safekeeping mode of operation that is a unipolar sensing mode in which the metal housing is grounded and the first generator connection terminal is connected to the amplifier for sensing electrical signals from a patient and the second generator connection terminal is connected to the metal housing.
Further, the generator preferably includes a first mode of operation that is a bipolar stimulation mode in which stimulation pulses are delivered between the first electrode and the second generator connection terminals. The first mode may include both the bipolar sensing and the bipolar detection. Similarly, the generator safekeeping mode of operation preferably includes a unipolar stimulation mode in which stimulation pulses are delivered between the one generator connection terminal and the other generator connection terminal. The safekeeping mode may include both the unipolar detection and unipolar stimulation.
One skilled in appreciate that the present invention can be practiced by other than the embodiments described herein, which are presented for purposes of illustration and not of limitation. | Systems, methods, and devices for protecting against effects of magnetic fields are provided. One implantable medical device includes a lead including a first conductor and a second conductor. The device further includes a generator including an electronic circuit, a metal housing that has a ground potential, and one or more switching devices. The switching devices, in a safekeeping configuration, are configured to disconnect the second conductor from the electronic circuit and to connect the second conductor to the ground potential of the metal housing. The first conductor is connected to the electronic circuit in the safekeeping configuration. The switching devices, in the safekeeping configuration, are configured to cause the second conductor to shield the first conductor from at least a portion of the effects of the magnetic field while the first conductor remains connected to the electronic circuit for use in performing a sensing operation and/or a stimulation operation. | 0 |
BACKGROUND
[0001] 1. Technical Field
[0002] The disclosure generally relates to gas turbine engines.
[0003] 2. Description of the Related Art
[0004] It is generally acknowledged that gas turbine engines for aircraft and other uses have a tendency to vibrate and generate noise at certain load ratings. To improve engine performance, it is desirable to reduce vibrations by strengthening the components of the engine and increasing the durability of the engine without increasing the weight of the engine. Also, it is desirable to shield the components of the engine from high temperatures where practical.
[0005] In the turbine case of a gas turbine engine, there are radially extending struts that are disposed in the path of the hot gases being exhausted from the turbine. The struts extend radially with respect to a longitudinal axis of the engine. The struts extend radially inwardly from the annular turbine exhaust case, through the path of the hot exhaust gases toward the longitudinal axis of the engine to a single axial location that is centrally located on the hub or “torque box.” As such, the struts are disposed in a single plane, positioned at an axial location as measured along the longitudinal axis of the engine. The struts support the hub, which, in turn, supports the bearings of the turbine. The struts, hub, bearings and other components of the engine are constructed in an attempt to withstand the engine vibrations and other load-bearing forces, such as gyroscopic forces and gravitational or G forces.
[0006] Because of the extreme heat of the exhaust gases flowing about the struts, it has become common practice to shield the struts from the high temperature and velocity of the exhaust gas by applying fairings about the struts. Typically, the fairings are aerodynamically shaped and tend to divert the hot gases around the struts.
[0007] It is desirable to make the struts relatively thick to increase the strength of the struts. However, by enlarging the breadth of the struts, the enlarged struts require more lateral space. The enlarged struts cause the fairings that are adjacent the struts to be larger and the larger fairings tend to apply more resistance to the flow of the hot gases through the turbine section.
[0008] It is also desirable to make the struts and the adjacent fairings relatively thin to reduce the drag associated with the fairings. However, by reducing the breadth of the fairings and the associated struts, the strength of the struts is also reduced. Unfortunately, the reduced strength of the struts tends to allow the hub to be more susceptible to the above described forces that may result primarily due to the offset bearing loads carried by the hub.
SUMMARY
[0009] Gas turbine engines and related systems involving a hub supported by offset struts are provided. In this regard, an exemplary embodiment of a bearing assembly for a gas turbine engine comprises: a bearing operative to support a rotatable shaft; an annular hub positioned concentrically about the bearing; and an annular array of struts extending radially outwardly from the hub, at least two of the struts being positioned in different planes, the planes being oriented transversely with respect to the rotatable shaft.
[0010] An exemplary embodiment of a gas turbine engine comprises: at least one set of rotatable blades operative to engage a stream of oncoming gas moving in a longitudinal, annular path through the engine; an annular turbine exhaust case positioned downstream of the rotatable blades and being operative to exhaust the gas; an annular hub positioned concentrically within the turbine exhaust case; and an annular array of struts positioned across the gas path and extending radially between the hub and the turbine exhaust case, at least one of the struts being longitudinally offset with respect to at least another of the struts.
[0011] Another exemplary embodiment of a gas turbine engine comprises: an annular turbine exhaust case; a hub positioned concentrically within the turbine exhaust case; a first strut connected to and extending substantially radially from the hub to the turbine exhaust case; and a second strut connected to and extending substantially radially from the hub to the turbine exhaust case, the second strut being longitudinally offset, at the hub, with respect to the first strut.
[0012] Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0014] FIG. 1 is a side cross-sectional view of an exemplary embodiment of a gas turbine engine.
[0015] FIG. 2 is a cross-sectional view of the upper half of a turbine exhaust case of the embodiment of FIG. 1 , showing a strut positioned in a forward offset position when connected to a hub.
[0016] FIG. 3 is a cross-sectional view of the upper half of the turbine exhaust case of the embodiment of FIG. 1 , but showing another strut that is positioned in an aft offset position when connected to the hub.
[0017] FIG. 4 is an end view of the hub and the adjacent portions of the struts connected to the hub, with the fairings removed from the struts.
[0018] FIG. 5 is a top view of the hub and the adjacent portions of the struts with the fairings removed from the struts, taken along lines 5 - 5 of FIG. 4 .
DETAILED DESCRIPTION
[0019] Gas turbine engines and related systems involving a hub with offset struts are provided, and exemplary embodiments will be described in detail. In some embodiments, some of the struts are connected to the hub at different distances along the length of the hub from others of the struts. The length of the hub is measured along the longitudinal axis of the engine. Because the connections of the struts to the hub are longitudinally offset with respect to a single axial location that is centrally located on the hub, these offset connections tend to facilitate stabilizing the position of the hub within the turbine exhaust case. In some of these embodiments, each strut may be associated with fairings adjacent the struts to facilitate shielding the struts from excessive heat of the exhaust gases of the engine.
[0020] Referring now to the drawings, FIG. 1 is a diagram depicting a representative embodiment of a gas turbine engine 100 . Although engine 100 is configured as a dual-spool turbofan, there is no intention to limit the invention to use with turbofans (or dual-spool configurations) as use with other types (and configurations) of gas turbine engines is contemplated.
[0021] As shown in FIG. 1 , gas turbine engine 100 incorporates an engine casing 101 that houses a fan 102 , a compressor section 104 , a combustion section 106 and a turbine section 108 . Compressor section 104 includes a low-pressure compressor 112 and a high-pressure compressor 114 , and turbine section 108 includes a high-pressure turbine 116 and a low-pressure turbine 118 . A low shaft 120 interconnects low-pressure turbine 118 with low-pressure compressor 112 , and a high shaft 122 interconnects high-pressure turbine 116 with high-pressure compressor 114 . Notably, shafts 120 and 122 are supported by a bearing assembly 130 , which generally includes bearings for the shafts and an associated hub and struts that support the bearings (described in detail later). The length of the hub and the longitudinal location of struts are herein described as measured along a longitudinal axis 124 of the gas turbine engine 100 .
[0022] During the operation of the gas turbine engine 100 , the combustion section 106 supplies fuel to air that is being drawn through the engine by the compressor section 104 . As a result, the combustion of the fuel creates a hot gas stream that flows through turbine section 108 . The hot gas stream impinges upon the blades of the turbines 116 , 118 to facilitate driving the corresponding compressors through shafts 120 , 122 .
[0023] Generally, the components of the gas turbine engine 100 tend to vibrate and G forces and gyroscopic forces tend to be applied through the bearings to the hub 142 (shown in FIGS. 2 and 3 ). In particular, forces are transmitted between the hub 142 , struts 144 , 146 and engine casing 101 . Notably, the exemplary bearing assembly 130 includes offset struts 144 , 146 .
[0024] As shown in FIGS. 2 and 3 , bearing assembly 130 includes a low bearing 168 (which supports shaft 120 ) and a high bearing 170 (which supports shaft 122 ). The bearings 168 , 170 interconnect with the hub 142 .
[0025] As shown in FIGS. 4 and 5 , multiple struts are attached to the hub 142 and extend radially outwardly from the hub 142 to the engine casing 101 . Both the forward struts 144 and the aft struts 146 extend radially from the longitudinal axis 124 of the engine. The struts 144 , 146 are connected to a turbine exhaust case portion 152 of the engine casing 101 . Notably, the embodiment of FIGS. 2 and 3 includes two sets of substantially cylindrical struts, with the forward struts 144 shown in FIG. 2 and the aft struts 146 shown in FIG. 3 . While twelve struts are shown in FIG. 4 , in other embodiments other numbers of sets and configurations of struts may be used.
[0026] As shown in FIGS. 4 and 5 , forward struts 144 are aligned in a forward plane 145 that is oriented transversely with respect to the longitudinal axis 124 of the gas turbine engine 100 and shafts 120 , 122 . As shown in FIG. 4 , the forward struts 144 are formed in a radial array about the hub 142 with the inner end portions 148 mounted to the hub 142 and the outer portions 150 ( FIG. 2 ) mounted to the engine casing 101 . In the exemplary embodiment, the inner end portions 148 of the forward struts 144 are threadedly mounted into threaded openings (not shown) formed in the hub 142 .
[0027] Likewise, the aft struts 146 are aligned in an aft plane 147 that is oriented transversely with respect to the longitudinal axis 124 of the gas turbine engine 100 and shafts 120 , 122 . The aft struts 146 of the rearward array of struts also are threadedly connected at their inner end portions 154 to the hub 142 , and their outer end portions 156 are connected to the engine casing 101 . In other embodiments, the struts 144 , 146 may be connected at their inner and outer ends by various means to the hub 142 and engine casing 101 , such as by threads, welding, pins, or other means.
[0028] Fairings, such as fairings 160 of FIG. 2 of the forward struts 144 , are adjacent the intermediate portion of each of the forward struts 144 for the purpose of directing the hot gases about the forward struts 144 . Likewise, fairings 162 of FIG. 3 are adjacent the intermediate portion of each of the aft struts 146 for the same purpose as the forward struts 144 . The fairings 160 , 162 may be attached at their inner and outer ends to the hub 142 and to the engine casing 101 , respectively, thereby also tending to shield the hub and the engine casing from the hot gases. While FIGS. 4 and 5 do not show the fairings so as to better illustrate the struts, it will be understood that a fairing may be positioned about some or all of the struts.
[0029] Since the array of forward struts 144 are longitudinally offset from the array of aft struts 146 , i.e., struts 144 and 146 reside in different planes that are oriented transversely with respect to the longitudinal axis 124 of the engine, as shown in FIGS. 4 and 5 . Thus, the hub 142 is more rigidly supported than the support typically provided by similarly sized struts arranged in an annular, single plane arrangement. Therefore, the vibrations and other forces applied to the hub 142 by the load from the bearings 168 and 170 tend to cause smaller deflections. In this arrangement, the struts 144 , 146 provide stronger support than when arranged in a single annular plane.
[0030] By using longitudinally offset forward and aft struts 144 and 146 , a stronger support can be provided to the hub 142 and the dimensions of the struts 144 , 146 can be reduced without compromising the ability of the struts 144 , 146 to stabilize the hub 142 . Thus, additional stability is applied to the hub 142 with a reduction in the breadth of the struts 144 , 146 , thereby allowing the adjacent fairings (e.g., fairings 160 , 162 ) to be thinner. This facilitates reducing the drag associated with the fairings.
[0031] In some embodiments, the hub 142 is formed in a substantially cylindrical shape and openings are formed through the hub 142 at the positions where the inner end portions 148 , 154 of the struts 144 , 146 are fastened. However, another exemplary hub may have a substantially non-circular shape if desired, such as an octangular shape or other shape that presents flat surfaces for receiving the inner end portions of the struts. For example, if a hub is to be supported by twelve struts, the hub may be formed in a substantially circular shape having twelve circumferentially spaced flats for receiving the inner end portions of the struts.
[0032] Forward struts 144 may be both longitudinally and circumferentially offset from aft struts 146 . In this regard, struts from one array may be spaced further apart from each other than the struts of another array. Additionally or alternatively, the spacing between the arrays may be different than the spacing between adjacent struts of a given array.
[0033] While the longitudinal spacing of the struts 144 , 146 in FIGS. 2 and 3 may appear to demonstrate a substantial separation of the arrays from each other, it will be understood that arrays of the struts 144 , 146 may be positioned closer together as shown in FIG. 5 so that they overlap one another in a common plane. However, increased longitudinal spacing between the arrays of struts tends to facilitate increasing stability applied to the hub. In some embodiments, the struts are longitudinally spaced from one another a distance equal to about one diameter of a strut, but other longitudinal spacings may be used.
[0034] In some embodiments, both a forward strut and an aft strut may be adjacent a single fairing, such as when the forward and aft strut are positioned in longitudinal alignment with each other. This may be used for the purpose of providing the desired strength of the hub while leaving another position empty of a strut but having a substantially hollow fairing present in the empty position. This arrangement provides more space for routing of fluids or cooling air, for example, through the empty fairing to other portions of the engine.
[0035] It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims. | Gas turbine engines and related systems involving offset hub struts are provided. In this regard, a representative bearing assembly for a gas turbine engine includes: a bearing operative to support a rotatable shaft; an annular hub positioned about the bearing; and an annular array of struts extending radially outwardly from the hub, at least two of the struts being positioned in different planes, the planes being oriented transversely with respect to the rotatable shaft. The method of assembling the struts by mounting first and second pluralities of struts, each plurality in a common plane, between the hub and the turbine exhaust case, with the second plurality of struts longitudinally offset from the first plurality of struts. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Application Ser. No. 62/263,508, filed on Dec. 4, 2015, from U.S. Provisional Application Ser. No. 62/322,144, filed on Apr. 13, 2016, and from U.S. Provisional Application Ser. No. 62/374,584, filed on Aug. 12, 2016, the entire contents of each of which applications are hereby incorporated by reference herein to the same extent as if fully rewritten.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention relates to an improved process for capturing pollutants that are the result of the combustion in furnaces of pollutant releasing fuels such as coal, trash, and residual oil, particularly combustion carried out in boilers associated with steam produced for use in electricity generating stations or in industrial processing operations.
[0004] Description of the Related Art
[0005] Various processes have been disclosed for capturing undesirable pollutants resulting from the combustion of fuels. Some of those processes include the introduction into the furnace, at various locations within the furnace, of sorbents of various types, including alkaline-earth-metal-based compounds. Also previously known is a process in which the alkalinity of normal coarse fly ash is utilized and is partially effective in dealing with condensable acids, which enables a small reduction in flue gas exit temperature, with an accompanying gain in fuel thermal efficiency. However, that process permits capture of only a fraction of the pollutants and provides only about one fifth of the potential gain from a reduction of the flue gas exit temperature. In that regard, normal coarse fly ash includes only a minor fraction of the desirable micron-sized fly ash particles.
SUMMARY OF THE INVENTION
[0006] Briefly stated, in accordance with one aspect of the present invention, a process is disclosed for improved and more economical capture of undesirable pollutants that result from fuel combustion in boilers associated with electricity generating stations. The process builds on the prior art technology involving the introduction into the combustion zone within the high temperature region of the furnace of a sorbent in the form of an alkaline-earth-metal-based compound in particulate form, in the furnace region within which the temperatures are in the range of from about 1090° C. to about 1260° C. to provide calcined particles. The calcined alkaline-earth-metal-based compound results in particles that are of micron and sub-micron size for capturing SO x and other pollutants.
[0007] However, a significant enhancement of the process economics achievable with the alkaline-earth-metal-based compounds can be realized either by supplementing or completely replacing them with a minor fraction of micronized coal particles that are introduced into the furnace combustion zone in a range of from about 0.5% to about 15% by weight of a coal fuel, along with the main fuel supply in the form of pulverized coal particles that also include coal ash. Alternatively, a similar fraction of the coal ash could be micronized independently, but with some difficulty due to the fused nature of the ash, and then injected into the combustion zone. Since some of the ash components tend to be less effective scavengers of SO 2 than the alkaline earths, but react readily with SO 3 , the process can be made more efficient by also introducing oxidizing agents into the combustion zone. Oxidants such as CaBr 2 , can be introduced either directly onto the surface of the coal before the coal is fed into the combustion zone, or the oxidants, which can include ozone from a gaseous generator or from peroxide solutions, can be introduced separately. Furthermore, an oxidant such as CaBr 2 can be combined with an alkaline-earth-metal-based sorbent for effective oxidation of SO 2 . Additionally, hydrogen peroxide can be introduced into the cooler regions of the system after the economizers. Both the use of oxidants and micronizing of the fuel into very fine particulates will also help with the control of NO x
BRIEF DESCRIPTION OF THE DRAWING
[0008] FIG. 1 is a flow chart showing the arrangement of the several apparatus components for carrying out the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] The processes herein disclosed relate to the capture of undesirable pollutants that result as products of the fossil fuel combustion process, particularly in coal-fired combustion systems such as those employed in industrial operations or in electrical power generating stations. Among the pollutants that are more effectively captured as a result of practicing the processes of the present invention are SO 2 , SO 3 , HCl, and toxic metals, such as mercury, selenium, lead, and arsenic. The present processes also relate to reducing the overall amount of CO 2 released in the course of capturing the other pollutants.
[0010] The notion of introducing a sorbent into a fossil fuel combustion zone for controlling the volume of emissions of pollutants resulting from the combustion process is described in at least the following U.S. patents and pending patent application, the entire contents of each of which is hereby incorporated by reference to the same extent as if fully rewritten:
[0011] U.S. Pat. No. 6,997,119 B2, issued on Feb. 14, 2006, entitled “Combustion Emissions Control and Utilization of Byproducts”;
[0012] U.S. Pat. No. 7,276,217 B2, issued on Oct. 2, 2007, entitled “Reduction of Coal-Fired Combustion Emissions”;
[0013] U.S. Pat. No. 7,971,540 B2, issued on Jul. 5, 2011, entitled “Control of Combustion System Emissions”;
[0014] U.S. Pat. No. 8,807,055 B2, issued on Aug. 19, 2014, entitled “Control of Combustion System Emissions”; and
[0015] U.S. Pat. No. 9,278,311 B2, issued on Mar. 8, 2016, entitled “Control of Combustion System Emissions.”
[0016] The present invention is directed to an improved process for capturing combustion system pollutants that is a modification of processes that are disclosed in the patents identified above. In addition to the introduction into the furnace combustion zone of alkaline-earth-metal-based compounds that are transformed by the heat of combustion into alkaline-earth-metal oxides for capturing particular pollutants, the present invention involves taking advantage of the ash that is present in the coals that are utilized as the fuel for combustion, wherein the coal ash serves either as a supplemental source of pollutant sorbent, or as the entirety of the pollutant sorbent.
[0017] The amount of ash that is present in coal is dependent upon the type and geographical source of the coal—anthracitic coals can have from about 10% to about 20% by weight of coal ash, whereas bituminous coals can have from about 5% to about 10% by weight of coal ash. Coal ash is composed of several metallic oxides, including, but not limited to CaO, MgO, Fe 2 O 3 , Al 2 O 3 , Na 2 O, K 2 O, and various alkali compounds. Each of the CaO and MgO, which are the primary scavengers of the undesirable pollutants, is present in the coal ash in minor amounts, of the nature of from about 0.6% to about 6.0% by weight of the coal ash, but, again, the amounts are dependent upon the geographical source of the coal, whether of eastern U.S. origin or of western U.S. origin. The coal ash components other than CaO and MgO will react more readily with SO 3 , than with SO 2 , which means that the micronizing of the coal ash, with or without injecting oxidizing agents, operates to convert substantially all of the ash components, except SiO 2 , to useful sorbents. Consequently, the micronization of only a small fraction of the coal ash is able to clean the flue gas of undesirable pollutants. Further, the micronization of the coal ash provides a large number of discrete particles, increasing the probability of contact of the coal ash sorbent particles with pollutant particles, capture of condensable acids that will allow increased cooling of the flue gases, thereby increasing the thermal efficiency gain of the furnace by 6 or 7 times over previous arrangements. The substitution of coarse fly with micronized ash will also have a positive impact on ash deposition
[0018] Typically, coal is supplied to a power generating station in the form of coal particles having a size of from about one-half inch to about 3 inches. Before their introduction into furnaces that serve for steam generation, the coal particles undergo particle size reduction in coal pulverizers that reduce the particle size to from about −200 mesh to a median size of about −325 mesh. The reduced-size coal particles are then conveyed from the coal pulverizer and injected into the combustion zone along with a sufficient quantity of air to form a combustible fuel/air mixture that upon combustion provides the heat necessary to transform water into the steam that is utilized to drive steam turbines that, in turn, drive generators to provide electricity distribution into the electrical grid for consumption by industrial, commercial, and individual users.
[0019] FIG. 1 shows a flow chart indicating the flow path of coal supplied to a furnace for combustion. The incoming raw coal of relatively large particle size, from about one-half inch to about 3 inches in size, is conveyed from a coal bunker at the furnace site, and is introduced into a coal pulverizer to further reduce the coal particle size. After passage through the coal pulverizer, in which the coal particles are reduced to a median particle size of about −325 mesh, the reduced size coal particles from the coal pulverizer are conveyed directly to the furnace for introduction into the combustion region along with combustion air. As described in the patents identified above, the coal particles can be supplemented with an alkaline-earth-metal compound in particulate form (from about 0.07 to about 3 microns) to serve as a sorbent for capturing undesirable pollutants resulting from the combustion process.
[0020] Alternatively, in the present invention a second portion of the incoming coal, a bypass flow of coal particles, from about 1% to about 15% by weight of the coal that leaves the coal pulverizer, is conveyed to a jet mill or to a wet or dry grinder to further reduce the size of the incoming coal particles to from about 0.5 microns to about 3 microns. The resultant, further-reduced-size coal particles that exit the jet mill or wet grinder include coal ash having compounds that when combusted provide micron-size, high surface area mineral particles that serve to capture the SO 2 and SO 3 that are some of the combustion products of coal combustion and that is captured and transformed into sulfate particles, which can then be separated from the flue gas at a point downstream of the furnace and collected as useful products. The flash calcined coal-ash-containing particles include minerals that capture SO 3 . In addition to the micronized minerals provided by the coal ash contained in the bypass flow of coal particles, the remaining flow of coal particles from the coal pulverizer includes all of the same mineral sorbents, but which are much coarser and less effective in scavenging pollutants.
[0021] The reduced-size oxide particles that result when the commercially micronized calcium or magnesium compounds are supplied as sorbents within the coal particle stream, as well as the bypass flow of similarly size-reduced coal and coal ash particles, are injected into the burner region of the furnace they can be of a particle size of from about 0.07 microns to about 3 microns, preferably about 0.5 microns (500 nanometers) and finer. Note that when not combined with the coal, the commercially micronized calcium or magnesium compounds and the micronized coal ash can also be introduced into other regions of the furnace, or in convection sections.
[0022] The external surface area of an about 0.5 micron median particle size reagent is about 40 to 88 times that of a commercially available −325 mesh (40 micron) limestone particle. The mineral particles in that preferred micron and sub-micron particle size results in about 61,000 to about 676,000 times as many sorbent particles per pound of material, as compared with the commercially available −325 mesh material. The result of the presence of such massive numbers of smaller mineral particles in the combustion zone of the furnace will be the capture of as much as or greater than 84% of the SO x , and up to 90+% of toxic metals, at a stoichiometric ratio of Ca/S of the sulfur content of the fuel of only about 1.5 times, or less.
[0023] In FIG. 1 , raw coal from a coal supply source, typically as coal particles having a size of from about one half inch to about three inches, more or less, is provided and is stored in a raw coal bunker 10 shown in FIG. 1 . For gravity flow of the coal particles, coal bunker 10 can be connected in overlying relationship with a coal mill or pulverizer 12 , that serves for reducing the size of the as-supplied raw coal to smaller sized coal particles, typically having a particle size of from about one millimeter to about 75 microns, more or less. If the coal is wet, addition to the coal of between about 2% to 5% by weight of a suitable flow agent can be provided without causing problems in moving the coal to the coal mill and to the burners. The amount of flow agent will vary with climate and season, but ordinary wet coal problems can be reduced to avoid excessive wetness of the coal when utilized with the sorbent flow agent disclosed herein. An example of a suitable flow agent is RAMsorb™ organic polymer, available from RAM-3 Combustion Technologies, 8765 West Market Street, Greensboro, N.C. 27409. The coal particles from the coal pulverizer 12 pass through conduit 14 for entry into the combustion region of furnace 20 along with combustion air to provide a fuel/air mixture for combustion.
[0024] The bypass path extends from coal pulverizer 12 to jet mill 16 and through bypass conduit 18 for introduction of micronized coal and/or micronized coal ash particles into the combustion region within furnace 20 . Dryer/mills, both wet and dry media mills or jet mills suitable for use in the bypass path illustrated in FIG. 1 and referred to above are available from the Hosokawa Micron Powder Systems division of Hosokawa Micron Corporation, 10 Chatham Road, Summit, N.J. 07901, such as its Micron Drymeister flash dryer unit that combines drying, milling, and classifying in a single installation. Another source of suitable dryer/mills is the Fluid Energy Equipment Division of Fluid Energy Processing & Equipment Co., 4300 Bethlehem Pike, Telford, Pa. 18969, which markets Thermajet® flash drying processing units. An example of a type of jet mill that can be utilized is one having the structure described in U.S. Pat. No. 3,840,188, entitled “Fluid Energy Drying and Grinding Mill.” Media Mills are also available from Union Process Company, located in Akron, Ohio
[0025] In one exemplary embodiment of the sorbent addition system shown in FIG. 1 , dried, reduced size, and deagglomerated sorbent particles of an alkaline-earth-metal of sub-micron size are intimately intermixed with the reduced size pulverized coal particles in coal mill 12 , to be conveyed to the burner heads for introduction through the furnace wall directly into burner heads at the combustion zone of the furnace, and without the need to provide additional sorbent injection openings in the furnace wall.
[0026] Alternatively, in a second exemplary embodiment of the sorbent addition system dried, reduced size coal and coal ash particles are also provided through bypass conduit 18 to flow directly to the burner heads for introduction directly into the combustion zone, either to supplement the externally-supplied sorbent that is added to or supplied with the pulverized coal particles, or to completely replace the externally supplied sorbent in order to encourage direct contact with the combustion products that are to be captured within the furnace, of the sub-micron size sorbent particles included in the further reduced size coal.
[0027] The effectiveness of the micronized coal ash particles as a sorbent for improved emissions control can be further enhanced by the addition to the coal of oxidants, such as CaBr 2 , provided in concentrations of under a few thousand ppm, in order to enhance the conversion of Hg to a scavengeable form. Additional improvements in emissions control can be achieved by the addition of H 2 O 2 in the cooler, convection pass of the boiler, where the temperature is between about 1800° F. to about 2200° F., or later downstream, to help to convert both SO x and NO x to scavengable form.
[0028] Both pulverized coal particles conveyed along the direct pathway through conduit 14 , and also the bypass flow of dried, further-size-reduced and deagglomerated coal and coal ash particles within bypass conduit 18 can be combined for introduction into the combustion region of the furnace. When so combined, the quantity of externally supplied alkaline-earth-based sorbent can be reduced because of the supplemental coal-ash-based mineral components contained in the coal ash, thereby reducing the need for a portion of the externally supplied sorbent.
[0029] As a further aspect of the present invention, the CaBr 2 oxidant, whether applied to the incoming coal or introduced separately and directly into the combustion zone, also serves to oxidize SO 2 to SO 3 . And both the micronized sorbent and the micronized fly ash serve to capture SO 3 to convert it to a sulfate, such as CaSO 4 . In that regard, the oxidant results in more of the micronized ash contributing to the acid gas scavenging in that the Fe 2 O 3 and the Al 2 O 3 components of the coal ash operate in addition to the CaO, MgO, and the traces of alkali metals present in the ash. By the improved scavenging of SO 3 , the flue gas temperature at the exit from the boiler can be reduced, thereby enabling an increase in the power plant operating efficiency of the order of about 6% to about 8%. Further, significant amounts of water can be recovered for in-plant use or for sale. And the capture of the acid-causing gases allows the substitution of less costly materials for the condensing heat exchangers
[0030] Additionally, by capturing pollutants, the micronized fly ash operates to minimize possible corrosive impact of the CaBr 2 and H 2 O 2 oxidants, it allows adjusting the SCR so that it oxidizes more SO 2 to SO 3 that can be captured by the micronized fly ash from the micronized coal. It also serves to minimize negative impacts on electrostatic precipitator performance, while also providing incremental NO x reduction. In connection with SO 2 capture by CaBr 2 , from about 2 to about 15% of micronized fly ash produced by the combustion of the coal and introduced into the scrubber, such as from a conventional powder classifier, can have the desired beneficial capture effect on the operation of that component of the system and can effectively provide a low cost sorbent for scrubber use. Moreover, the micronized ash can is useful as a free scrubbing reagent, and SCR-type devices can be used to oxidize the SO 2 by catalysis, in contrast to the chemical reactions provided by the CaBr 2 and the H 2 O 2 .
[0031] The concept of deploying oxidants to convert the SO 2 to SO 3 to enhance pollutant capture efficiency can also be used when the capital cost for micronizing the ash is not available. In fact, when CaBr 2 is the oxidant, both it and the sorbent-based scavenging agent can be applied directly onto the coal at a point before the coal mill, either as a powder or as a liquid blend, or the CaBr 2 can be introduced separately, either in powdered form or in solution. The quantity of oxidant utilized is based upon the sulfur content of the coal to be fired. It can range from as little as 0.5 of the stoichiometric amount to 3, 4, or more times the stoichiometric amount that would be needed to oxidize the chosen amount of sulfur to be captured. Similarly, the amount of alkaline sorbent will be from as low as 1 to as high as 4 times the stoichiometric amount for the anticipated amount of SO 3 that is generated by the oxidation.
[0032] When ash is the sorbent, the fraction micronized will be determined by the capacity of the micronizing equipment, the chemistry of the ash, and the economics and feasibility of the specific milling system that is employed. The dosage will be constrained by the specific milling system and the type and amount of coal, but the target dosage will fall into a similar range based upon the stoichiometric capacity of the ash, which will be based upon the ash components that are cited earlier herein. The CaBr 2 and the ozone can be effective when they are delivered in the high temperature combustion zone, but the H 2 O 2 must be delivered into a cooler region of the system.
[0033] As earlier noted, a combination of an oxidant such as CaBr 2 with an alkaline-earth-metal-based sorbent and applied to coal is effective for oxidation of SO 2 to SO 3 . The ratio of the bromide to the amount of SO 2 to be oxidized would be less than about 3 times the stoichiometric amount of SO 2 in the flue gas. Similarly, the amount of the scavenging sorbent mixed with a CaBr 2 oxidant solution and added to the fuel would be a function of the amount of SO 2 to be converted to SO 3 .
[0034] Other sorbents suitable for oxidizing SO 2 and following gas-phase ozone exposure include mineral dusts found in the atmosphere and that include metal oxides such as MgO, Al 2 O 3 , Fe 2 O 3 , TiO 2 , and SiO 2 , as well as CaCO 3 , China loess, and other suitably sized byproducts or waste materials.
[0035] Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention. It is therefore intended to encompass within the appended claims all such changes and modifications that fall within the scope of the present invention. | A process for capturing undesirable combustion products produced in a high temperature combustion system in which a carbonaceous fuel is utilized. Very finely sized particles of alkaline earth carbonates or hydroxides, with or without added ground ash, are provided in slurry form, are dried and milled to provide unagglomerated, sub-micron-sized particles that are injected along with pulverized coal and an oxidizing agent into the high temperature combustion zone of a furnace. The particles capture and neutralize the gases that result in condensable acids, including SO x , NO x , HCL, and HF, as well as capturing toxic metals that are present in the combustion products, they mitigate ash fouling and slagging, and they facilitate economic heat exchange that permits fuel savings and recovery of water for use in other processes. | 5 |
BACKGROUND OF THE INVENTION
The invention relates to a boxing training device involving the action of at least one reaction body on a mobile reaction area.
Various arrangements are known for training boxers. The most common training devices are a punching ball fixed on an elastic bar, a boxing ball fixed between ropes, and a sandbag. These devices are more or less suited for training punches but are not suited for training spatially or temporally coordinated boxing movements.
SUMMARY OF THE INVENTION
The object of the invention is to construct a device providing training situations with spatially staggered movement planes similar to competition conditions.
According to the invention, this object is achieved by using a reaction body that takes up the kinetic energy produced during the action of at least one boxing glove, said energy being dependent on punching force and punching direction, and transmitting this energy to a measuring device.
Such a device is used for training spatially and temporarily coordinated boxing movements, including combinations of such movements, as well mechanical punching exercises. The device according to the invention can be used simultaneously by two boxers in a competition and can show the effect of actions in spatially staggered movement planes. The results obtained by registering a punch (hit), or a combination series of punches can be required from the boxer, whereby the time element is also taken into account. This device responds in direct relation to the action of the user. Measuring the result (hits) is performed by a simple method. Physical strength and persistence are trained as well as reactivity and realization, and mastering of changing situations. An individual adjustment of the degree of difficulty is achieved by changing movable parts of the device. Furthermore, the device is adapted to the user. Due to unexpected situations, the device is very amusing and can be used in sporting clubs and other institutions.
Further features of the invention are described hereinafter relative to the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a device with reaction bodies that rotate around a vertical axis, in a front view;
FIG. 2 is a top view of the device according to FIG. 1;
FIGS. 3-5 illustrate a further embodiment of the invention having reaction bodies rotating around a vertical axis in a front view, in a sectional side view and in a top view, respectively;
FIGS. 6-8 show an embodiment of a device with horizontal shifting reaction bodies in a front elevational view, a sectional plan view taken along line VII--VII in FIG. 6, and a sectional side view taken along line VIII--VIII in FIG. 8. respectively; and
FIGS. 9 and 10 show a further embodiment of a device with horizontal shifting reaction bodies in a front view and a side view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a device 1 with two reaction bodies 5 that are arranged on a pedestal 25. The reaction bodies are in the form of vertically shiftable revolution bodies 9 that rotate around a respective vertical axis of rotation 13. Each rotational axis 13 is, therefore, provided as a threaded spindle on which the revolution body 9 slides by being provided with one or more nuts that have a thread pitch matched to the spindle thread and are separately and movably arranged on the spindle thread for enabling rotation of revolution body 9 with low friction force.
This device 1 is suitable for enabling two boxers 8 to spar without body contact while still providing the character of full competition. Depending on the punching force and punching frequency of each boxer 8 as well as the punching direction, the revolution bodies 9 will either move up or down from the central position due to their opposite rotations, represented by arrows in FIG. 2. A draw game is also possible, if each of the boxers 8 move one revolution body to their advantage.
A measuring scale 14 is provided in proximity to the revolution bodies 9, extending axially relative to the rotational axes 13, for showing the exact height of the revolution body 9 and the training result. It is also possible to provide a vertical console 15 on the frame 26 of device 1 with another measuring scale. Special electronic measuring devices are not necessary to show the training results, because the height displacement of the revolution body 9 from the central position is always due to the punching force and punching frequency of the boxer 8. On the other hand, appropriate sensors can still be provided which are connected, for example, to an optical or acoustical indicating instrument 24. This indicating instrument 24 can be mounted to the console 15.
The reaction areas of revolution bodies 9 can be provided e.g. with padded bars (A, B, C, and D in FIG. 2). The pedestal 25 and frame 26 prevent the boxers 8 from getting near each other. But it is also possible to provide a net between the revolution bodies so that direct body contact between boxers 8 is absolutely prevented.
A further device 2 is shown in FIGS. 3 to 5, comprising four revolution bodies 10 which constitute the reaction bodies 5. Two revolution bodies 10 are always arranged one above the other. The rotational axes 13 of revolution bodies 10 are arranged in a box type frame 20. The box type frame 20 is supported upon a pedestal 25 by means of a support 27. The revolution bodies 10 are peripherally profiled with a number of reaction areas 11 (FIG. 5).
An elastic body 21 is provided in front of each revolution body 10 at both sides of box type frame 20 with each pair of elastic bodies 21 being connected to the box type frame 20 by means of a rope 28. Bodies 21 can be in the form of, e.g., boxing balls. Device 2 can be used by one or two boxers 8 without body contact but with full competition character. Special rotations of revolution bodies 10 are caused by punches of boxers 8 on the elastic bodies 21, if the elastic bodies 21 reach the reaction areas 11 of revolution bodies 10. Since punches on the elastic bodies 21 on one side of the device will produce an opposite rotation of the revolution bodies 5 from punches directed from the opposite side of the device, the number of revolutions detected as left- or right-hand rotations can be attributed to a particular one of the boxers 8. For this, two commutating switches 29 are provided as sensors of the measuring device for transmitting a signal to an indicating instrument 24, which may be an optical or acoustical indicating instrument, for example, a LED-display corresponding to a boxer 8. Revolution bodies 10 can be provided with a foam core covered with leather.
A device 3 is shown in FIGS. 6 to 8 which may be used for individual training. If such devices are used, for motivation, the practical replacement of the competitor is very important. The device 3 is also provided with a box type frame 20 that is supported on a pedestal by means of supports 27. Circular recesses 30 with padded edges 31 are arranged at the front side 32 of the device, and have a smaller diameter than that of the ball type reaction bodies 21 used in device 3. Upwardly curved channel-like pathways 33 are arranged in the rear of box type frame 20, and are provided with parallel metal bars 34 through which a weak current is passed. A globule 16 is arranged on each curved pathway 33 as a reaction body. The curved pathways 33 and the ball type elastic bodies 21 are so arranged that balls and globules meet at the center plane of the frame 20 at which a dividing wall is provided between the section with ball type bodies 21 and the sections carrying the globules 16. The sloping guide surfaces of pathways 33 and circular openings 36 are constructed to make sure that each globule 16 can reach a position where it will be pushed by a ball type body 21 without passing the dividing wall. Openings 36 are therefore smaller than the diameter of globules 16. Attitude sensors 23 are provided at pathways 33 near openings 36. Metal bars 34 also form an attitude sensor 23, but extend over the width of paths 33. According to the position of a globule 16, signal transmitters 22 are activated by attitude sensor 23, so as to designate, via an indicator lamp, a recess 30 at which a body 21 must be hit. If the hit is in time, body 21 pushes a globule 16, which runs up its pathway 33 and produces impulses via parallel metal bars 34. The number of hits can be recorded by means of an indicating instrument 24, e.g. a digital counter. Then the globule 16 runs back to one of the openings 36 and gives a new impulse via attitude sensor 23 to the signal transmitter 22.
A device 4 is shown in FIGS. 9 and 10 with elastic bodies 21 that are formed by tethered boxing balls and with reaction bodies 6 that are formed by freely movable boxing balls 37. The balls 37 forming reaction bodies 6 are independently movably arranged in a multi-storey frame 38 that is elastically mounted in a box type frame 20 by means of springs 39. Box type frame 20 is supported upon pedestal 25 by means of support 27. The device 4 can be used by one boxer 8, and a competitor is indicated behind the boxing balls 37 via an illuminated mirror 40.
A pressure sensor 42 is arranged at a point positioned on rear wall 41 of frame 38, and sensor 42 may be formed by a piezoelectric switch that serves as an attitude sensor 23. Pressure sensors 42 are located behind each reaction body 6 formed by a boxing ball 37. That means a punch on one of the tethered boxing balls 37 forming a body 21 is only scored if the free boxing ball 37 located just behind that body 21 is pushed back sufficiently to hit the respective sensor 42. The bottom plates 43, upon which the reaction bodies 6 roll, incline upwardly to an elevation 44 in the range of pressure sensors 42. Consequently, the reaction body 6 will not rest at that sensing position, so that the boxing ball 37 must be punched immediately. As a result, the boxer 8 is always confronted with a complex situation. He should first tip the free boxing balls 37, located in the elastically mounted frame 38, to put them in the line of fire and then punch the bodies 21, provided by the tethered boxing balls 37. The device 4, therefore, works as an accommodating sparring partner. The more intensively the device is used, the more intensive are the reactions required from the boxer 8.
The bodies 21 are tethered to the box type frame 20 by means of ropes 28. Signal transmitters 22 are provided with indicator lamps. Only one pressure sensor 42 is activated as a target position during a special period of time, and that one is designated by the respective indicator lamp. The signal transmitters 22 can be controlled by a randomizer, so that the requirements that must be met by the boxer 8 may be made even more complex. The pressure sensors 42 are connected to an indicating instrument 24 that is provided with an optical display, e.g. a LED-display. An acoustical indicating instrument can additionally be provided.
The devices 1 to 4, described hereinbefore, mediate characteristic features of boxing such as strength, staying power, agility, and reaction in a practical way. Although a direct fight with all problems of health is excluded, important advantages are still present, e.g. measuring the strength of two or more people fighting against each other, reaction training, physical training based upon age, weight, and efficiency, as well as the activation of the cardiovascular system. | A boxing training device involving the action of at least two reaction bodies that move in response to kinetic energy imposed by the glove of a boxer either directly upon a reaction body or indirectly via an elastic body. The result of the boxing impact imposed is displayed via a measuring device. Embodiments for training of one boxer or competitive training of two boxers are achieved, as are embodiments involving freely movable and tethered elastic bodies used in conjunction with freely movable reaction bodies. | 0 |
This application is the U.S. national phase under 35 USC 371 of Int'l Application No. PCT/EP2006/010270, filed 25 Oct. 2006, which designated the U.S. and claims priority to European Patent Application No. 05023813.8, filed 2 Nov. 2005; the entire contents of each of which are hereby incorporated by reference.
SEQUENCE LISTING
The instant application contains a Sequence Listing which has been submitted in ASCII format via EFS-Web and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Aug. 2, 2011, is named 4662-788.txt and is 67.628 bytes in size.
The present invention provides modified transketolase enzymes. Microorganisms synthesizing one of the modified transketolases instead of the wild type transketolase are prototroph for aromatic amino acids and impaired in using carbon sources that are assimilated via the pentose phosphate pathway. The modified enzymes and polynucleotides encoding the same can be used in the fermentation process for substances that use ribose-5-phosphate, ribulose-5-phosphate, or xylulose-5-phosphate as substrate for the biosynthesis such as e.g. riboflavin, riboflavin precursors, flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD), and derivatives thereof. They also can be used for the production of pyridoxal phosphate (vitamin B 6 ), guanosine and adenosine and derivatives of these nucleotides.
BACKGROUND OF THE INVENTION
Riboflavin (vitamin B 2 ) is synthesized by all plants and many microorganisms but is not produced by higher animals. Because it is a precursor to coenzymes such as flavin adenine dinucleotide and flavin mononucleotide that are required in the enzymatic oxidation of carbohydrates, riboflavin is essential to basic metabolism. In higher animals, insufficient riboflavin can cause loss of hair, inflammation of the skin, vision deterioration, and growth failure.
The enzymes required catalyzing the biosynthesis of riboflavin from guanosine triphosphate (GTP) and ribulose-5-phosphate are encoded by four genes (ribG, ribB, ribA, and ribH) in B. subtilis . These genes are located in an operon, the gene order of which differs from the order of the enzymatic reactions catalyzed by the enzymes. For example, GTP cyclohydrolase II, which catalyzes the first step in riboflavin biosynthesis, is encoded by the third gene in the operon, ribA. The ribA gene also encodes a second enzymatic activity, i.e., 3,4-dihydroxy-2-butanone 4-phosphate synthase (DHBPS), which catalyzes the conversion of ribulose-5-phosphate to the four-carbon unit 3,4-dihydroxy-2-butanone 4-phosphate (DHBP). Deaminase and reductase are encoded by the first gene of the operon, ribG. The penultimate step in riboflavin biosynthesis is catalyzed by lumazine synthase, the product of the last rib gene, ribH. Riboflavin synthase, which controls the last step of the pathway, is encoded by the second gene of the operon, ribB. The function of the gene located at the 3′ end of the rib operon is, at present, unclear; however, its gene product is not required for riboflavin synthesis.
Transcription of the riboflavin operon from the ribP1 promoter is controlled by an attenuation mechanism involving a regulatory leader region located between ribP1 and ribG. ribO mutations within this leader region result in deregulated expression of the riboflavin operon. Deregulated expression is also observed in strains containing missense mutations in the ribC gene. The ribC gene has been shown to encode the flavin kinase/FAD synthase of B. subtilis (Mack, M., et al., J. Bacteriol., 180:950-955, 1998). Deregulating mutations reduce the flavokinase activity of the ribC gene product resulting in reduced intracellular concentrations of flavin mononucleotide (FMN), the effector molecule of the riboflavin regulatory system.
Engineering of riboflavin production strains with increased production rates and yields of riboflavin has been achieved in the past in a number of different ways. For instance, (1) classical mutagenesis was used to generate variants with random mutations in the genome of the organism of choice, followed by selection for higher resistance to purine analogs and/or by screening for increased production of riboflavin. (2) Alternatively, the terminal enzymes of riboflavin biosynthesis, i.e., the enzymes catalyzing the conversion of guanosine triphosphate (GTP) and ribulose-5-phosphate to riboflavin, were over-expressed, resulting also in a higher flux towards the target product. The metabolic flux into and through a biosynthetic pathway, e.g. the riboflavin biosynthetic pathway, is determined by the specific activities of the rate-limiting enzymes of this particular pathway and by the intracellular concentrations of the substrates for these enzymes. Only at or above saturating substrate concentrations an enzyme can operate at its maximal activity. The saturating substrate concentration is a characteristic feature for each enzyme. For example, the metabolic flux into the riboflavin pathway may be increased or kept at a high level by keeping the intracellular concentrations of ribulose-5-phosphate above or as close as possible to the saturating substrate concentration of the 3,4-dihydroxy-2-butanone 4-phosphate synthase, a presumed rate limiting enzyme for the riboflavin biosynthetic pathway. High intracellular concentrations of ribulose-5-phosphate may, for example, be reached by preventing or interfering with drainage of ribulose-5-phosphate into the central metabolism via the non-oxidative part of the pentose phosphate pathway.
A key enzyme in the non-oxidative part of the pentose phosphate pathway is the transketolase enzyme, which catalyzes the reversible conversion of ribose-5-phosphate and xylulose-5-phosphate to seduheptulose-7-phosphate and glyceraldehyde-3-phosphate. In addition, transketolase catalyzes also the conversion of fructose-6-phosphate and glyceraldehyde-3-phosphate to xylulose-5-phosphate and erythrose-4-phosphate (Kochetov, G. A. 1982, Transketolase from yeast, rat liver, and pig liver, Methods Enzymol., 90:209-23).
It has previously been reported that transketolase deficient Bacillus subtilis strains carrying knock-out mutations in the transketolase encoding gene produces ribose, which accumulates in the fermentation broth (De Wulf, P., and E. J. Vandamme. 1997. Production of D-ribose by fermentation, Appl. Microbiol. Biotechnol. 48:141-148; Sasajima, K., and Yoneda, M. 1984, Production of pentoses by microorganisms. Biotechnol. and Genet. Eng. Rev. 2: 175-213). Obviously, increased intracellular C5 carbon sugar pools can be reached in transketolase knock-out mutants up to a level that exceeds the physiological requirements of the bacteria and leads to secretion of excess ribose.
As mentioned above, transketolase catalysed reactions are also required to produce erythrose-4-phosphate, from which the three proteinogenic aromatic amino acids are derived. Therefore, transketolase deficient microorganisms are auxotroph for these amino acids. They can only grow if these amino acids or their biosynthetic precursors, for instance shikimic acid, can be supplied via the cultivation medium.
In addition to the unfavorable auxotrophy for aromatic amino acids or shikimic acid, transketolase-deficient B. subtilis mutants show a number of severe pleiotropic effects like very slow growth on glucose, a defective phosphoenolpyruvate-dependent phosphotransferase system, deregulated carbon catabolite repression, and altered cell membrane and cell wall composition (De Wulf, P., and E. J. Vandamme. 1997).
An other transketolase-deficient riboflavin secreting B. subtilis strain was described by Gershanovich et al. (Gershanovich V N, Kukanova A I a, Galushkina Z M, Stepanov A I (2000) Mol. Gen. Mikrobiol. Virusol. 3:3-7).
Furthermore, U.S. Pat. No. 6,258,554 B1 discloses a riboflavin overproducing Corynebacterium glutamicum strain in which transketolase activity is deficient. It can be noted form the disclosure of the U.S. Pat. No. 6,258,554 B1 that the deficiency in transketolase activity and the resulting amino acid auxotrophy was essential for the improved riboflavin productivity, since a prototrophic revertant produced riboflavin in amounts similar to a C. glutamicum strain with a wild-type transketolase background.
These disadvantages, i.e. auxotrophy for aromatic amino acids and further pleiotropic effects discussed above, make a transketolase deficient mutant a less preferable production strain for stable industrial processes, such as, e.g. the industrial production of riboflavin within such strain.
SUMMARY OF THE INVENTION
It is in general an object of the present invention to provide a transketolase mutant strain which is modified in such a way that the catalytic properties of the modified transketolase allowing higher intracellular ribulose-5-phosphate and ribose-5-phosphate concentrations than those of the non-modified transketolase, but which does not have the disadvantages of the transketolase-deficient strains mentioned above.
Surprisingly, it has now been found that by genetically altering a microorganism such as for instance B. subtilis , by replacing the wild-type gene by a mutated gene encoding a modified transketolase that allows some residual flux through the pentose phosphate pathway by having modulated specific activities, the production of a fermentation product such as e.g. riboflavin can be significantly improved without loosing the prototrophic properties.
The present invention relates to modified transketolases, polynucleotide sequences comprising a gene that encodes a modified transketolase with properties described above, a host cell which has been transformed by such a polynucleotide sequence, and a process for the biotechnological production of a fermentation product such as for instance riboflavin, a riboflavin precursor, FMN, FAD, pyridoxal phosphate or one or more derivatives thereof based on a host cell in which the wild-type transketolase gene has been stably replaced by a polynucleotide coding for the mutated transketolase.
As a first step to isolate mutants, in which the wild-type transketolase is replaced by one of such modified transketolases, a deletion mutant may be generated that is auxotroph for the proteinogenic aromatic amino acids and cannot grow with carbon sources assimilated via the pentose phosphate pathway, e.g. gluconate. The transketolase deletion mutant may then be transformed with a mixture of DNA fragments encoding various transketolase mutants. Prototrophic transformants may be isolated, from which those are selected which show a reduced growth rate on gluconate. Mutants isolated according to this method may synthesize modified transketolase enzymes that allow sufficient erythrose-4-phosphate biosynthesis to prevent auxotrophic growth, but act as a bottle neck for assimilation of gluconate. In addition, the undesired pleiotropic effects typically observed with B. subtilis transketolase deletion mutants may be prevented. U.S. Pat. No. 6,258,554 B1 indicates that together with the reversion of the auxotrophic to the prototrophic growth riboflavin secreting C. glutamicum transketolase mutants lost their ability to produce more riboflavin than a similar strain containing a wild-type transketolase gene. As shown in the examples of the present invention, prototrophic B. subtilis transketolase mutants isolated as outlined above unexpectedly produced more riboflavin than the transketolase wild-type parent strain, whereas a transketolase deletion mutant had partly lost their riboflavin production capabilities.
Methods for the introduction of mutations into DNA fragments are well known in the art. Transketolase mutants can be generated for instance by protein engineering using one of the available 3D structures of e.g. the yeast transketolase (Lindqvist, Y., G. Schneider, U. Ermler, and M. Sundstrom. 1992. Three-dimensional structure of transketolase, a thiamine diphosphate dependent enzyme, at 2.5 A resolution. Embo. J. 11:2373-9) for selecting suitable positions of the amino acid sequence or by random mutagenesis. The selection process in both cases may be done as described above. The modified transketolase—when it is used as substitution for the wild-type transketolase—exhibits catalytic properties, i.e. modulated specific activities, which allow the growth of a host cell on a carbon source that is metabolized exclusively by the pentose phosphate pathway (for example gluconate) with a reduced growth rate in comparison to a host cell containing the wild-type transketolase. These properties result in higher intracellular ribulose-5-phosphate and ribose-5-phosphate concentrations and a residual flux through the pentose phosphate pathway, so that sufficient erythrose-4-phosphate can be produced to prevent auxotrophic growth.
“Wild-type enzyme” or “wild-type transketolase” which can be used for the present invention may include any transketolase as defined above that is used as starting point for designing mutants according to the present invention. The wild-type transketolase may be of eukaryotic or prokaryotic, preferably fungal or bacterial origin, in particular selected from Escherichia, Bacillus, Corynebacterium, Saccharomyces, Eremothecium, Candida or Ashbya , preferably from E. coli, B. subtilis, B. licheniformis, B. halodurans, S. cerevisiae, E. gossypii, C. flareri or A. gossypii or any transketolase having an amino acid sequence which is homologous to an amino acid sequence as shown in FIG. 1 . Most preferably the transketolase is from B. subtilis . “Homologous” refers to a transketolase that is at least about 50% identical, preferably at least about 60% identical, more preferably at least about 70%, 80%, 85%, 90%, 95% identical, and most preferably at least about 98% identical to one or more of the amino acid sequences as shown in FIG. 1 . “Wild-type” in the context of the present invention may include both transketolase sequences derivable from nature as well as variants of synthetic transketolase enzymes (as long as they are homologous to any one of the sequences shown in FIG. 1 ), The terms “wild-type transketolase” and “non-modified transketolase” are used interchangeably herein.
The term “% identity”, as known in the art, means the degree of relatedness between polypeptide or polynucleotide sequences, as the case may be, as determined by the match between strings of such sequences. “Identity” can be readily determined by known methods, e.g., with the program BESTFIT (GCG Wisconsin Package, version 10.2, Accelrys Inc., 9685 Scranton Road, San Diego, Calif. 92121-3752, USA) using the following parameters: gap creation penalty 8, gap extension penalty 2 (default parameters).
A “mutant”, “mutant enzyme”, “mutated enzyme” or “mutant transketolase” or a “modified transketolase” as used herein means any variant derivable from a given wild-type enzyme/transketolase (according to the above definition) according to the teachings of the present invention and, when used for replacing the wild-type gene of a host organism/cell should have an effect on the growth on e.g. gluconate and/or ribose. For the scope of the present invention, it is not relevant how the mutant(s) are obtained; such mutants may be obtained, e.g., by site-directed mutagenesis, saturation mutagenesis, random mutagenesis/directed evolution, chemical or UV mutagenesis of entire cells/organisms, etc. These mutants may also be generated, e.g., by designing synthetic genes, and/or produced by in vitro (cell-free) translation. For testing of specific activity, mutants can may be (over-) expressed by methods known to those skilled in the art. The terms “mutant transketolase”, “modified transketolase” or “mutated transketolase” are used interchangeably herein.
“Host cell” is a cell capable of producing a given fermentation product and containing the wild-type transketolase, or a nucleic acid encoding the modified transketolase according to the invention. Suitable host cells include cells of microorganisms.
As used herein, the term “specific activity” denotes the reaction rate of the wild-type and mutant transketolase enzymes under properly defined reaction conditions as described in Kochetov (Kochetov, G. A. 1982. Transketolase from yeast, rat liver, and pig liver. Methods Enzymol 90:209-23). The “specific activity” defines the amount of substrate consumed and/or product produced in a given time period and per defined amount of protein at a defined temperature. Typically, “specific activity” is expressed in μmol substrate consumed or product formed per min per mg of protein. Typically, μmol/min is abbreviated by U (=unit). Therefore, the unit definitions for specific activity of μmol/min/(mg of protein) or U/(mg of protein) are used interchangeably throughout this document. It is understood that in the context of the present invention, specific activity must be compared on the basis of a similar, or preferably identical, length of the polypeptide chain.
Many mutations may change a wild-type transketolase in such a way that growth on gluconate is affected as described above.
It is an object of the present invention to provide a modified transketolase having the properties defined above, wherein the amino acid sequence of the modified transketolase contains at least one mutation when compared with the amino acid sequence of the corresponding non-modified transketolase.
The at least one mutation may be an addition, deletion and/or substitution.
Preferably, the at least one mutation is at least one amino acid substitution wherein a given amino acid present in the amino acid sequence of the non-modified transketolase is replaced with a different amino acid in the amino acid sequence of the modified transketolase of the invention. The amino acid sequence of the modified transketolase may contain at least one amino acid substitution when compared with the amino acid sequence of the corresponding non-modified transketolase. Particularly, a modified transketolase as of the present invention contains at least one mutation on an amino acid position which corresponds to amino acid position 357 of the B. subtilis transketolase amino acid sequence as depicted in SEQ ID NO:2.
In further embodiments, the modified transketolase contains at least two, at least three, at least four or at least five substitutions when compared with the amino acid sequence of the corresponding transketolase. For example, the modified transketolase contains one to ten, one to seven, one to five, one to four, two to ten, two to seven, two to five, two to four, three to ten, three to seven, three to five or three to four amino acid substitutions when compared with the amino acid sequence of the corresponding non-modified transketolase.
In a preferred embodiment of the invention the non-modified transketolase is obtainable from Bacillus , preferably B. subtilis , as depicted in SEQ ID NO:2. The corresponding DNA sequence is shown in SEQ ID NO:1. The modified transketolase contains at least one mutation on position 357 of SEQ ID NO:2, leading to a modified transketolase having the above described properties.
The at least one amino acid substitution in the non-modified transketolase located on a position corresponding to amino acid 357 as shown in SEQ ID NO:2 may be selected from substitution R357H, R357A, R357S, R357N, R357T, R357K, R3571, R357V, R357G, and R357L.
In a particularly preferred embodiment, the mutated transketolase consists of one substitution which affects the amino acid position corresponding to amino acid position 357 of the amino acid sequence as shown in SEQ ID NO:2 and which may be selected from substitution R357H, R357A, R357S, R357N, R357T, R357K, R3571, R357V, R357G, and R357L.
In an other preferred embodiment, the modified transketolase contains at least two amino acid substitutions when compared with the amino acid sequence of the corresponding non-modified transketolase, wherein at least one mutation corresponding to amino acid position 357 of the amino acid sequence as shown in SEQ ID NO:2 and which may be selected from substitution R357H, R357A, R357S, R357N, R357T, R357K, R3571, R357V, R357G, and R357L.
The amino acid present in the non-modified transketolase is preferably arginine at position 357. The amino acid in the sequence of the non-modified transketolase may be changed to histidine, alanine, serine, asparagine, lysine, threonine, leucine, glycine, isoleucine or valine at position 357. Preferably, the substitution at the amino acid position corresponding to position 357 of the sequence as shown in SEQ ID NO: 2 consists of the replacement of arginine with histidine, arginine with alanine, arginine with serine, arginine with leucine, arginine with lysine, arginine with asparagine, arginine with threonine, arginine with glycine, arginine with isoleucine, arginine with valine.
The modified transketolase of the invention may comprise foreign amino acids, preferably at its N- or C-terminus. “Foreign amino acids” mean amino acids which are not present in a native (occurring in nature) transketolase, preferably a stretch of at least about 3, at least about 5 or at least about 7 contiguous amino acids which are not present in a native transketolase. Preferred stretches of foreign amino acids include but are not limited to “tags” that facilitate purification of the recombinantly produced modified transketolase. Examples of such tags include but are not limited to a “His 6 ” tag (SEQ ID NO: 31), a FLAG tag, a myc tag, and the like. For calculation of specific activity, the values need to be corrected for these additional amino acids (see also above).
In another embodiment the modified transketolase may contain one or more, e.g. two, deletions when compared with the amino acid sequence of the corresponding non-modified transketolase. Preferably, the deletions affect N- or C-terminal amino acids of the corresponding non-modified transketolase and do not significantly reduce the functional properties, e.g., the specific activity, of the enzyme.
The invention further relates to a polynucleotide comprising a nucleotide sequence which codes for a modified transketolase according to the invention. “Polynucleotide” as used herein refers to a polyribonucleotide or polydeoxyribonucleotide that may be unmodified RNA or DNA or modified RNA or DNA. Polynucleotides include but are not limited to single- and double-stranded DNA, DNA that is a mixture of single- and double-stranded regions, single- and double-stranded RNA, and RNA that is a mixture of single- and double-stranded regions, hybrid molecules comprising DNA and RNA that may be single-stranded or, more typically, double-stranded or a mixture of single- and double-stranded regions. The term “polynucleotide” includes DNA or RNA that comprises one or more unusual bases, e.g., inosine, or one or more modified bases, e.g., tritylated bases.
The polynucleotide of the invention can easily be obtained by modifying a polynucleotide sequence which codes for a non-modified transketolase. Examples of such polynucleotide sequences encoding non-modified transketolase enzymes include but are not limited to the amino acid sequences of FIG. 1 . Preferably, the non-modified transketolase is originated from Bacillus , in particular B. subtilis , more preferred is a polynucleotide encoding a non-modified transketolase as depicted in SEQ ID NO:2.
Methods for introducing mutations, e.g., additions, deletions and/or substitutions into the nucleotide sequence coding for the non-modified transketolase include but are not limited to site-directed mutagenesis and PCR-based methods.
DNA sequences of the present invention may be constructed starting from genomic or cDNA sequences coding for transketolase enzymes known in the state of the art, as are available from, e.g., Genbank (Intelligenetics, California, USA), European Bioinformatics Institute (Hinston Hall, Cambridge, GB), NBRF (Georgetown University, Medical Centre, Washington D.C., USA) and Vecbase (University of Wisconsin, Biotechnology Centre, Madison, Wis., USA) or from the sequence information disclosed in FIG. 1 by methods of in vitro mutagenesis [see e.g. Sambrook et al., Molecular Cloning, Cold Spring Harbor Laboratory Press, New York]. Another possibility of mutating a given DNA sequence which may also be suitable for the practice of the present invention is mutagenesis by using the polymerase chain reaction (PCR). DNA as starting material may be isolated by methods known in the art and described, e.g., in Sambrook et al. (Molecular Cloning) from the respective strains/organisms. It is, however, understood that DNA encoding a transketolase to be constructed/mutated in accordance with the present invention can also be prepared on the basis of a known DNA sequence, e.g. by construction of a synthetic gene by methods known in the art (as described, e.g., in EP 747483).
Once complete DNA sequences of the present invention have been obtained, they can be integrated into vectors or directly introduced into the genome of a host organism by methods known in the art and described in, e.g., Sambrook et al. (s.a.) to (over-) express the encoded polypeptide in appropriate host systems. However, a man skilled in the art knows that also the DNA sequences themselves can be used to transform the suitable host systems of the invention to get (over-) expression of the encoded polypeptide.
In a preferred embodiment the present invention provides
(i) a DNA sequence which codes for a modified transketolase carrying at least one mutation as defined above and which hybridizes under standard conditions with any of the DNA sequences of the specific modified transketolase enzymes, for example which hybridizes with the DNA sequences according to SEQ ID NO:1, or (ii) a DNA sequence which codes for a modified transketolase carrying at least one mutation as defined above but, because of the degeneracy of the genetic code, does not hybridize but which codes for a polypeptide with exactly the same amino acid sequence as a DNA sequence which hybridizes under standard conditions with any of the DNA sequences of the specific modified transketolase enzymes of the present invention, or (iii) a DNA sequence which is a fragment of such modified DNA sequences which maintains the activity properties of the polypeptide of which it is a fragment.
“Standard conditions” for hybridization mean in the context of the present invention the conditions which are generally used by a man skilled in the art to detect specific hybridization signals and which are described, e.g. by Sambrook et al., “Molecular Cloning”, second edition, Cold Spring Harbor Laboratory Press 1989, New York, or preferably so-called stringent hybridization and non-stringent washing conditions or more preferably so-called stringent hybridization and stringent washing conditions a man skilled in the art is familiar with and which are described, e.g., in Sambrook et al. (s.a.). A specific example of stringent hybridization conditions is overnight incubation (e.g., 15 hours) at 42° C. in a solution comprising: 50% formamide, 5×SSC (150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH 7.6), 5×Denhardt's solution, 10% dextran sulfate, and 20 μg/ml of denatured, sheared salmon sperm DNA, followed by washing the hybridization support in 0.1×SSC at about 65° C.
In another preferred embodiment the invention further provides a DNA sequence which can be obtained by the so-called polymerase chain reaction method (“PCR”) by PCR primers as shown in FIG. 2 , designed on the basis of the specifically described DNA sequences.
The polypeptides and polynucleotides of the present invention are preferably provided in an isolated form, and preferably purified to homogeneity.
The term “isolated” means that the material is removed from its original environment (e.g., the natural environment if it is naturally occurring). For example, a naturally-occurring polynucleotide or polypeptide present in a living microorganism is not isolated, but the same polynucleotide or polypeptide, separated from some or all of the coexisting materials in the natural system, is isolated. Such polynucleotides could be part of a vector and/or such polynucleotides or polypeptides could be part of a composition and still be isolated in that such vector or composition is not part of its natural environment.
An isolated polynucleotide or nucleic acid as used herein may be a DNA or RNA that is not immediately contiguous with both of the coding sequences with which it is immediately contiguous (one on the 5′-end and one on the 3′-end) in the naturally occurring genome of the organism from which it is derived. Thus, in one embodiment, a nucleic acid includes some or all of the 5′-non-coding (e.g., promoter) sequences that are immediately contiguous to the coding sequence. The term “isolated polynucleotide” therefore includes, for example, a recombinant DNA that is incorporated into a vector, into an autonomously replicating plasmid or virus, or into the genomic DNA of a prokaryote or eukaryote, or which exists as a separate molecule (e.g., a cDNA or a genomic DNA fragment produced by PCR or restriction endonuclease treatment) independent of other sequences. It also includes a recombinant DNA that is part of a hybrid gene encoding an additional polypeptide that is substantially free of cellular material, viral material, or culture medium (when produced by recombinant DNA techniques), or chemical precursors or other chemicals (when chemically synthesized). Moreover, an “isolated nucleic acid fragment” is a nucleic acid fragment that is not naturally occurring as a fragment and would not be found in the natural state.
As used herein, the term isolated polypeptide refers to a polypeptide that is substantially free of other polypeptides. An isolated polypeptide is preferably greater than 80% pure, more preferably greater than 90% pure, even more preferably greater than 95% pure, most preferably greater than 99% pure. Purity may be determined according to methods known in the art, e.g., by SDS-PAGE and subsequent protein staining. Protein bands can then be quantified by densitometry. Further methods for determining the purity are within the level of ordinary skill.
As mentioned above, the modified transketolases and the corresponding polynucleotides of the invention may be utilized in the genetic engineering of a suitable host cell to make it better and more efficient in the fermentation process for substances that use ribose-5-phosphate, ribulose-5-phosphate, or xylulose-5-phosphate as substrate for the biosynthesis. The presence of said modified transketolase within a suitable host cell may result in higher intracellular ribulose-5-phosphate and ribose-5-phosphate concentrations and a residual flux through the pentose phosphate pathway within said recombinant host, so that sufficient erythrose-4-phosphate can be produced to prevent auxotrophic growth.
Appropriate host cells are for example fungi, like Aspergilli, e.g. Aspergillus niger or Aspergillus oryzae , or like Trichoderma , e.g. Trichoderma reesei , or Ashbya , e.g. Ashbya gossypii , or Eremothecium , e.g. Eremothecium ashbyii , or yeasts like Saccharomyces , e.g. Saccharomyces cerevisiae , or Candida , like Candida flareri , or Pichia , like Pichia pastoris , or Hansenula polymorpha , e.g. H. polymorpha (DSM 5215). Bacteria which can be used are, e.g., Bacilli as, e.g., Bacillus subtilis or Streptomyces , e.g. Streptomyces lividans. E. coli which could be used are, e.g., E. coli K12 strains, e.g. M15 or HB 101.
Thus, the present invention relates to a microorganism wherein the activity of a transketolase is modified in such a way that the microorganism is capable of growing on a carbon source that is metabolized exclusively by the pentose phosphate pathway (for example gluconate) with a reduced growth rate in comparison to a host cell containing the wild-type transketolase. It is in general possible to introduce an obtained transketolase mutant originating from a certain organism e.g. B. subtilis in the same organism again and now used as a host cell or to introduce any obtained mutant into any other relevant host cells.
As used herein, the term “growth rate” denotes to the following: Bacterial cells reproduce by dividing in two. If growth is not limited, doubling continues at a constant rate so both the number of cells and the rate of population increase doubles with each consecutive time period. For this type of exponential growth, plotting the natural logarithm of cell number against time (preferably in hours) produces a straight line. The slope of this line is the specific growth rate of the organism, which is a measure of the number of divisions per cell per unit time. In food, bacteria cannot grow continuously as the amount of nutrient available will be finite and waste products will accumulate. In these conditions growth curves tend to be sigmoid.
It is an object of the present invention to provide a recombinant host cell wherein the growth rate of said recombinant host cell (e.g. microorganism) according to the present invention carrying a modified transketolase on a carbon source that is metabolized exclusively by the pentose phosphate pathway, in particular gluconate, is less than 100% when compared to the wild-type organism. In particular, the growth rate may be reduced by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or even 90% and more compared to the growth rate of a wild-type organism. Preferably, the growth rate reduction is between 10% and 90%, more preferably between 20% and 80%, still more preferably between 25% and 75% compared to a cell containing a wild-type transketolase gene.
Especially, the invention relates to a genetically engineered/recombinantly produced host cell (also referred to as recombinant cell or transformed cell) in which the wild-type transketolase gene has been replaced by a modified transketolase gene encoding an enzyme that allows a slightly or non-reduced growth on a carbon source that is not exclusively metabolized by the pentose phosphate pathway, but shows a clearly reduced growth rate when the organism grows on a carbon source that is metabolized exclusively by the pentose phosphate pathway. Such genetically engineered host cells show an improvement of the yield of the fermentation product and of the efficiency of the production process with the advantages that undesired auxotrophic growth and pleiotropic effects can be prevented.
The invention further relates to a process for producing a host cells capable of expressing a transketolase according to the invention, comprising the steps of
(i) generating mutated transketolases displaying modulated activities in comparison to the respective wild-type enzyme, i.e. a) providing a polynucleotide encoding a first or non-modified transketolase with catalytic properties that should be adapted; b) introducing one or more mutations into the polynucleotide sequence such that the mutated polynucleotide sequence encodes a new or modified transketolase which contains at least one amino acid mutation when compared to the first transketolase wherein the at least one amino acid mutation may be at amino acid corresponding to position 357 of the amino acid sequence as shown in SEQ ID NO: 2; c) optionally inserting the mutated polynucleotide in a vector or plasmid; (ii) replacing the wild-type transketolase(s) of the host cell by a transketolase variant from the same organisms or another organism that allows normal or slightly reduced growth on a carbon source that is not exclusively metabolized by the pentose phosphate pathway, but shows an effect on the growth rate when the organism grows on a carbon source that is metabolized exclusively by the pentose phosphate pathway, i.e. a) replacing the wild-type transketolase of a suitable wild-type host cell without altering the regulatory sequences of the gene; b) determining the growth rate on gluconate in minimal medium and comparing it to the wild-type host strain; and c) selecting transketolase mutants that allow a growth rate on gluconate which is less than 100% of the wild-type strain.
The invention further relates to a method for the production of substances that are secondary products of ribose-5-phosphate, ribulose-5-phosphate, or xylulose-5-phosphate comprising:
a) culturing a genetically engineered/recombinantly produced host cell in which the wild-type transketolase gene has been replaced by a modified transketolase gene encoding an enzyme that allows a slightly or non-reduced growth on a carbon source that is not exclusively metabolized by the pentose phosphate pathway, but which shows a reduced growth rate when the organism grows on a carbon source that is metabolized exclusively by the pentose phosphate pathway, in a suitable medium under conditions that allow expression of the modified transketolase; and b) separating the fermentation product from the medium.
The “fermentation product” as used herein may be any product produced by a suitable host cell as defined above the biosynthesis of which uses ribose-5-phosphate, ribulose-5-phosphate, or xylulose-5-phosphate as substrate. Examples of such fermentation products include but are not limited to riboflavin, riboflavin precursors, flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD) and derivatives thereof, pyridoxal phosphate (vitamin B 6 ), guanosine, adenosine and derivatives of these nucleotides.
“Riboflavin precursor” and “derivatives of riboflavin, FMN or FAD” in the context of this invention shall include any and all metabolite(s) requiring ribulose-5-phosphate or ribulose-5-phosphate as an intermediate or substrate in their (bio-) synthesis. In the context of this patent application, it is irrelevant whether such (bio-) synthesis pathways are natural or non-natural (i.e., pathways not occurring in nature, but engineered biotechnologically). Preferably, the synthesis pathways are biochemical in nature. Riboflavin precursors and derivatives of riboflavin, FMN or FAD include but are not limited to: DRAPP; 5-amino-6-ribosylamino-2,4 (1H,3H)-pyrimidinedione-5′-phosphate; 2,5-diamino-6-ribitylamino-4 (3H)-pyrimidinone-5′-phosphate; 5-amino-6-ribitylamino-2,4 (1H,3H)-pyrimidinedione-5′-phosphate; 5-amino-6-ribitylamino-2,4 (1H,3H)-pyrimidinedione; 6,7-dimethyl-8-ribityllumazine (DMRL); and flavoproteins. The term “riboflavin” also includes derivatives thereof, such as e.g. riboflavin-5-phosphate and salts thereof, such as e.g. sodium riboflavin-5-phospate.
The polynucleotides, polypeptides, recombinant host cells and methods described herein may be used for the biotechnological production of either one or more of the fermentation products as defined above.
Methods of genetic and metabolic engineering of suitable host cells according to the present invention are known to the man skilled in the art. Similarly, (potentially) suitable purification methods for e.g. riboflavin, a riboflavin precursor, FMN, FAD, pyridoxal phosphate or one or more derivatives thereof are well known in the area of fine chemical biosynthesis and production.
It is understood that a method for biotechnological production of a fermentation product such as for instance riboflavin, a riboflavin precursor, FMN, FAD, pyridoxal phosphate or one or more derivatives thereof according to the present invention is not limited to whole-cellular fermentation processes as described above, but may also use, e.g., permeabilized host cells, crude cell extracts, cell extracts clarified from cell remnants by, e.g., centrifugation or filtration, or even reconstituted reaction pathways with isolated enzymes. Also combinations of such processes are in the scope of the present invention. In the case of cell-free biosynthesis (such as with reconstituted reaction pathways), it is irrelevant whether the isolated enzymes have been prepared by and isolated from a host cell, by in vitro transcription/translation, or by still other means.
Fermentation media must contain suitable carbon substrates. Suitable substrates may include but are not limited to monosaccharides such as glucose or fructose, oligosaccharides such as lactose or sucrose, polysaccharides such as starch or cellulose or mixtures thereof and unpurified mixtures from renewable feedstocks. It is contemplated that the source of carbon utilized in the present invention may encompass a wide variety of carbon containing substrates and will only be limited by the choice of organism.
The various embodiments of the invention described herein may be cross-combined.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be illustrated in more detail by the following non-limiting examples. These examples are described with reference to the Figures.
FIG. 1-1 , FIGS. 1-2 , and FIGS. 1-3 shows—as already mentioned above—examples of polynucleotide sequences which code for a non-modified transketolase, and
FIG. 2 shows a set of primers, in which tkt 1S is SEQ ID NO:3, tkt 1AS is SEQ ID NO:13, tkt 1ASohne is SEQ ID NO:6, tkt 2S is SEQ ID NO:4, tkt 2AS is SEQ ID NO:4, tkt 3S is SEQ ID NO:9, tkt 4S is SEQ ID NO:10, tkt 5S is SEQ ID NO:11, tkt 6S is SEQ ID NO:12, tkt 357AS is SEQ ID NO:14, tkt Rec 1S is SEQ ID NO:27, tkt Rec 1AS is SEQ ID NO:28, tkt Rec 2S is SEQ ID NO:29, tkt Rec 2AS is SEQ ID NO:30, tkt 357A-S is SEQ ID NO:17, tkt 357N-S is SEQ ID NO:15, tkt 357K-S is SEQ ID NO:18, tkt 357Q-S is SEQ ID NO:16, tkt 357S-S is SEQ ID NO:19, tkt 357T-S is SEQ ID NO:20, tkt 357H-S is SEQ ID NO:21, tkt 357V-S is SEQ ID NO:22, tkt 3571-S is SEQ ID NO:23, tkt 357L-S is SEQ ID NO:24, tkt 357M-S is SEQ ID NO:25, tkt 357G-S is SEQ ID NO:26, rpi MutS is SEQ ID NO:5.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In particular, FIG. 1 shows multiple sequence alignment calculated by the program clustalW (1.83) of the transketolase amino acid sequences from Escherichia coli (TKT_ECOLI), Bacillus subtilis (TKT_BACSU), Bacillus licheniformis (TKT_BACLD), Bacillus halodurans (TKT_BACHD), Corynebacterium glutamicum (TKT_CORGL), Saccharomyces cerevisiae (TKT_YEAST), and Ashbya gossypii (TKT_ASHGO). Positions that are homologous/equivalent to the amino acid residue 357 of the B. subtilis transketolase that are discussed in one of the following examples are in bold letters. The numbering used for those positions is done according to the B. subtilis wild-type amino acid sequence. This type of alignment can be done with CLUSTAL or PILEUP using standard parameters. As shown, the amino acid sequence of transketolases is highly conserved. In particular, in all transketolases shown and in much more transketolases not shown, arginine 357 (numbering according to the B. subtilis transketolase) is conserved. Therefore, the type of experiment using the concepts and mutations reported here can also be done with other transketolases having an arginine at a position homologous to position 357 of the amino acid sequence of B. subtilis transketolase like Ashbya gossypii for improving the production of riboflavin, riboflavin derivatives or compounds having ribose-5-phosphate, xylulose-5-phosphate, or ribulose-5-phosphate as a precursor. It is also possible to replace an original transketolase gene of an organism by a B. subtilis transketolase mutant gene mutated at position 357 with or without adaptation of the DNA sequence to the new organism. It is not essential that the transketolase mutant genes originate from an organism in which it is going to be introduced. The practical steps required for another host organism are published and known to an expert in the field and outlined somewhere else.
EXAMPLE 1
Isolation of Genomic DNA from Bacillus subtilis
gDNA was prepared using the DNeasy Tissue Kit from Qiagen (QIAGEN GmbH, QIAGEN Str. 1, 40724 Hilden, Germany) according to the description of the supplier. 1 ml of a 3 ml overnight culture of B. subtilis in VY liquid medium (Becton Dickinson, Sparks, Md. 21152, USA) incubated at 37° C. (250 rpm) was used as source for the bacteria cells. At the end, the gDNA was eluted in 200 μl of AE buffer (supplied with the Kit).
EXAMPLE 2
Amplification of the Transketolase Gene from Bacillus subtilis
gDNA from B. subtilis PY79 (P. Youngman, J. Perkins, and R. Losick (1984), Construction of a cloning site near one end of Tn917 into which foreign DNA may be inserted without affecting transposition in Bacillus subtilis or expression on the transposon-borne erm gene. Plasmid 12:1-9; see Example 1) was used for amplification of the tkt gene. According to the genomic DNA sequence, the tkt gene contains one Eco RI site inside of its coding sequence (SEQ ID NO: 1). Since the Eco RI restriction site is generally used for cloning into E. coli expression vectors such as pQE80 (QIAGEN GmbH, QIAGEN Str. 1, 40724 Hilden, Germany), the site was deleted by replacing C315 by a T, which is a silent mutation changing the phenylalanine codon from TTC to TTT. For this, two separate PCRs A and B were performed. The following PCR conditions were used for PCR A: 2 μM of primer tkt 1S (according to SEQ ID No: 3, see also FIG. 2 ) and tkt 2AS (according to SEQ ID No: 4, FIG. 2 ), 0.2 mM of each nucleotide (ATP, GTP, TTP, CTP), 2.5 U of a proof-reading DNA polymerase (Stratagene, Gebouw California, 1101 CB Amsterdam Zuidoost, The Netherlands), 100 ng genomic DNA (Example 1) in the appropriate buffer as supplied together with the DNA polymerase.
Temperature regulation was as follows:
Step 1: 3 min at 95° C. Step 2: 30 sec at 95° C. Step 3: 30 sec at 52° C. Step 4: 30 sec at 72° C. Step 5: 5 min at 72° C.
Steps 2 to 4 were repeated 35-times.
PCR B was done under the following conditions: 2 μM of primer tkt 2S (according to SEQ ID No: 8, FIG. 2 ) and tkt 1AS (according to SEQ ID No: 13, FIG. 2 ), 0.2 mM of each nucleotide (ATP, GTP, TTP, CTP), 2.5 U of a proof-reading DNA polymerase (Stratagene, Gebouw California, 1101 CB Amsterdam Zuidoost, The Netherlands), 100 ng genomic DNA (Example 1) in the appropriate buffer as supplied together with the DNA polymerase.
Temperature regulation was as follows:
Step 1: 3 min at 95° C. Step 2: 30 sec at 95° C. Step 3: 30 sec at 52° C. Step 4: 2 min at 72° C. Step 5: 5 min at 72° C.
Steps 2 to 4 were repeated 35-times.
The two PCR products A and B were purified by Agarose gel electrophoresis and a following extraction out of the gel using the MinElute Gel Extraction Kit from Qiagen (QIAGEN GmbH, QIAGEN Str. 1, 40724 Hilden, Germany). Using the overlapping region of PCR products A and B, it was possible to assemble them by a third PCR: 2 μM of primer Rpi MutS (according to SEQ ID No: 5, FIG. 2 ) and tkt 1ASohne (according to SEQ ID No: 6, FIG. 2 ), 0.2 mM of each nucleotide (ATP, GTP, TTP, CTP), 2.5 U of a proof-reading DNA polymerase (Stratagene, Gebouw California, 1101 CB Amsterdam Zuidoost, The Netherlands), 100 ng of PCR product A and PCR product B in the appropriate buffer as supplied together with the DNA polymerase.
Step 1: 3 min at 95° C. Step 2: 30 sec at 95° C. Step 3: 30 sec at 53° C. Step 4: 2.5 min at 72° C. Step 5: 5 min at 72° C.
Steps 2 to 4 were repeated 35-times.
The PCR products were purified with the help of the Qiagen PCR purification Kit (QIAGEN GmbH, QIAGEN Str. 1, 40724 Hilden, Germany) and eluted in 50 μl elution buffer. The PCR product was confirmed by an Eco RI digestion. For further confirmation, it was sequenced with the primers tkt IS, tkt 2S, tkt 2AS, tkt 3S (according to SEQ ID No: 9, FIG. 2 ), tkt 4S (according to SEQ ID No: 10, FIG. 2 ), tkt 5S (according to SEQ ID No: 11, FIG. 2 ), tkt 6S (according to SEQ ID No: 12, FIG. 2 ), tkt 1AS.
EXAMPLE 3
Construction of Tkt Mutants
The 3D structure of the yeast transketolase was available together with a selection of mutations that showed influence on substrate binding of the yeast transketolase (Nilsson, U., L. Meshalkina, Y. Lindqvist, and G. Schneider. 1997. At position R359 (number 357 in the B. subtilis transketolase), the original arginine was replaced by nearly all other amino acids. The construction of the mutants was basically done as described in example 1. An amino acid sequence alignment comprising the transketolases from yeast, B. subtilis and from other organisms is shown in FIG. 1 .
Using the Eco RI-free tkt gene as template (Example 2), the mutations were introduced as already described for the deletion of the Eco RI site: The following PCR conditions were used for PCR A and B: 2 μM of primer Rpi MutS (A) or tkt 357nnn-S (B) and tkt 357AS (A) (according to SEQ ID No: 14, FIG. 2 ) or tkt 1ASohne (B), 0.2 mM of each nucleotide (ATP, GTP, TTP, CTP), 2.5 U of a proof-reading DNA polymerase (Stratagene, Gebouw California, 11011 CB Amsterdam Zuidoost, The Netherlands), 100 ng of the Eco RI-free tkt gene (Example 2) in the appropriate buffer as supplied together with the DNA polymerase. In the case of PCR B the sense primer was chosen according to the amino acid that was introduced: tkt 357N-S (according to SEQ ID No: 15, FIG. 2 ) for asparagine, tkt 357Q-S (according to SEQ ID No: 16, FIG. 2 ) for glutamine, tkt 357A-S (according to SEQ ID No: 17, FIG. 2 ) for alanine, tkt 357K-S (according to SEQ ID No: 18, FIG. 2 ) for lysine, tkt 357S-S (according to SEQ ID No: 19, FIG. 2 ) for serine, tkt 357T-S (according to SEQ ID No: 20, FIG. 2 ) for threonine, tkt 357H-S (according to SEQ ID No: 21, FIG. 2 ) for histidine, tkt 357V-S (according to SEQ ID No: 22, FIG. 2 ) for valine, tkt 3571-S (according to SEQ ID No: 23, FIG. 2 ) for Isoleucine, tkt 357L-S (according to SEQ ID No: 24, FIG. 2 ) for leucine, tkt 357M-S (according to SEQ ID No: 25, FIG. 2 ) for methionine, and tkt 357G-S (according to SEQ ID No: 26, FIG. 2 ) for the introduction of glycine at position 357 of the B. subtilis transketolase.
Temperature regulation was as follows:
Step 1: 3 min at 95° C. Step 2: 30 sec at 95° C. Step 3: 30 sec at 52° C. Step 4: 60 sec at 72° C. Step 5: 5 min at 72° C.
Steps 2 to 4 were repeated 35-times.
The two PCR products A and B were purified by Agarose gel electrophoresis and a following extraction out of the gel using the MinElute Gel Extraction Kit from Qiagen (QIAGEN GmbH, QIAGEN Str. 1, 40724 Hilden, Germany). Assembling of PCR product
A and B was done in a third PCR: 2 μM of primer Rpi MutS and tkt 1ASohne, 0.2 mM of each nucleotide (ATP, GTP, TTP, CTP), 2.5 U of a proof-reading DNA polymerase (Stratagene, Gebouw California, 1101 CB Amsterdam Zuidoost, The Netherlands), 100 ng of PCR product A and PCR product B in the appropriate buffer as supplied together with the DNA polymerase.
Step 1: 3 min at 95° C. Step 2: 30 sec at 95° C. Step 3: 30 sec at 53° C. Step 4: 2.5 min at 72° C. Step 5: 5 min at 72° C.
Steps 2 to 4 were repeated 35-times.
The PCR products of the transketolase were purified with the Qiagen PCR purification Kit (QIAGEN GmbH, QIAGEN Str. 1, 40724 Hilden, Germany) and eluted in 50 μl elution buffer. The PCR products were used for the transformation of B. subtilis.
EXAMPLE 4
Construction of a Transketolase-Deficient B. subtilis Strain
For the marker free introduction of a mutated transketolase gene into the original tkt locus of the B. subtilis genome, a transketolase-deficient strain was constructed. Two DNA fragments obtained by PCR comprising base pair 452 to 1042 and base pair 1562 to 2001 of the B. subtilis transketolase gene (SEQ ID NO: 2) were combined with the neomycin resistance gene cassette (M. Itaya, K. Kondo, and T. Tanaka. 1989. A neomycin resistance gene cassette selectable in a single copy state in the Bacillus subtilis chromosome. Nucleic Acids Res 17:4410). The following PCR conditions were used for PCR A: 2 μM of primer tkt Rec1S (according to SEQ ID No: 27, FIG. 2 ) and tkt Rec1AS (according to SEQ ID No: 28, FIG. 2 ), 0.2 mM of each nucleotide (ATP, GTP, TTP, CTP), 2.5 U of a proof-reading DNA polymerase (Stratagene, Gebouw California, 1101 CB Amsterdam Zuidoost, The Netherlands), 100 ng of the amplified tkt gene of Example 2 in the appropriate buffer as supplied together with the DNA polymerase.
Temperature regulation was as follows:
Step 1: 3 min at 95° C. Step 2: 30 sec at 95° C. Step 3: 30 sec at 52° C. Step 4: 30 sec at 72° C. Step 5: 5 min at 72° C.
Steps 2 to 4 were repeated 30-times.
PCR B was done under the following conditions: 2 μM of primer tkt Rec 2S (according to SEQ ID No: 29, FIG. 2 ) and tkt Rec 2AS (according to SEQ ID No: 30, FIG. 2 ), 0.2 mM of each nucleotide (ATP, GTP, TTP, CTP), 2.5 U of a proof-reading DNA polymerase (Stratagene, Gebouw California, 1101 CB Amsterdam Zuidoost, The Netherlands), 100 ng of the amplified tkt gene of Example 2 in the appropriate buffer as supplied together with the DNA polymerase.
Temperature regulation was as follows:
Step 1: 3 min at 95° C. Step 2: 30 sec at 95° C. Step 3: 30 sec at 52° C. Step 4: 2 min at 72° C. Step 5: 5 min at 72° C.
Steps 2 to 4 were repeated 30-times.
The two PCR products A and B were purified by Agarose gel electrophoresis and a following extraction out of the gel using the MinElute Gel Extraction Kit from Qiagen (QIAGEN GmbH, QIAGEN Str. 1, 40724 Hilden, Germany). Due to the overlapping regions of the two PCR products A and B with the sequence of the neomycin resistance cassette, it is possible to assemble them by a third PCR: 2 μM of primer tkt Rec 1S and tkt Rec 2AS, 0.2 mM of each nucleotide (ATP, GTP, TTP, CTP), 2.5 U of a proof-reading DNA polymerase (Stratagene, Gebouw California, 1101 CB Amsterdam Zuidoost, The Netherlands), 100 ng of PCR product A, 100 ng of PCR product B, and 100 ng of neomycin resistance cassette in the appropriate buffer as supplied together with the DNA polymerase.
Step 1: 3 min at 95° C. Step 2: 30 sec at 95° C. Step 3: 30 sec at 55° C. Step 4: 2.5 min at 72° C. Step 5: 5 min at 72° C.
Steps 2 to 4 were repeated 35-times.
Five assembling PCRs were pooled and purified with the Qiagen PCR purification Kit (QIAGEN GmbH, QIAGEN Str. 1, 40724 Hilden, Germany) and eluted in 50 μl elution buffer. The correct PCR product was confirmed by agarose gel electrophoresis and used for transformation of B. subtilis PY79. Preparation of competent B. subtilis cells was done according to Kunst et al., 1988 (F. Kunst, M. Debarbouille, T. Msadek, M. Young, C.
Mauel, D. Karamata, A. Klier, G. Rapoport, and R. Dedonder. 1988. Deduced polypeptides encoded by the Bacillus subtilis sacU locus share homology with two-component sensor-regulator systems. J Bacteriol 170: 5093-101). 2 ml MNGE+Bacto Casamino Acid (CAA) (9 ml MN-medium (13.6 g/l K 2 HPO 4 , 6.0 g/l KH 2 PO 4 , 0.88 g/l sodium citrate*2H 2 O), 1 ml glucose (20%), 40 μl potassium glutamate (40%), 50 μl, ammonium iron(III) citrate (2.2 mg/l, freshly prepared), 100 μl tryptophan (8 mg/l), 30 μl MgSO 4 (1 M), +/−50 μl Bacto Casamino Acid (20%, Becton Dickinson AG, Postfach, CH-4002 Basel, Switzerland) were inoculated with a single colony and incubated overnight at 37° C. and 250 rpm. This culture was used to inoculate 10 ml MNGE+CAA (start OD 500 nm of 0.1) and was incubated at 37° C. under shaking (250 rpm) until it reached an OD 500 nm of 1.3. The culture was diluted with the same volume of MNGE w/o CAA and was incubated for another hour. After a centrifugation step (10 min, 4000 rpm, 20° C.), the supernatant was decanted into a sterile tube. The pellet was re-suspended in ⅛ of the kept supernatant. 300 μl of cells were diluted in 1.7 ml MN (1×), 43 μl glucose (20%) and 34 μl MgSO 4 (1 M). 10 and 20 μl of the prepared PCR product was added to 400 μl of the diluted competent cells and shaked for 30 min at 37° C. 100 μl expression mix (500 μl 5% yeast extract (Becton Dickinson AG, Postfach, CH-4002 Basel, Switzerland), 125 μl CAA (20%), 1/100 of the final antibiotic concentration (2 μg/ml neomycin), if used for selection, and 750 μl sterile bidest. water) were added and the cells were shaked for 1 h at 37° C. At the end, the cells were spun down, suspended in 200 μl of the supernatant and plated onto TBAB plates (Becton Dickinson AG, Postfach, CH-4002 Basel, Switzerland) containing 2 μg/ml neomycin.
Two transformants were grown in VY medium (5 g/l yeast extract (Becton Dickinson AG, Postfach, CH-4002 Basel, Switzerland), 25 g/l veal infusion broth (Sigma)). From one of the transformants, designated BS3402, the genomic DNA was isolated as described in Example 1 and the correct replacement of the transketolase DNA fragment from base pair 1043 to 1561 by the neomycin gene cassette was confirmed by a standard PCR using tkt Rec 1 S and tkt Rec 2AS as primers. As expected for a transketolase deletion mutant, the strain could not grow on ribose or gluconate as sole carbon source and required all three aromatic amino acids or shikimic acid for growth.
EXAMPLE 5
Transformation of the Transketolase-Deficient B. subtilis Strain BS3402 with the Genes of the Transketolase Variants
0.5 and 1 μg DNA of the amplified transketolase gene and its variants (Example 2 and 3) were used to transform BS3402 as described in Example 4. Positive colonies were identified by growth on minimal medium (2 g/l glucose and sorbitol in SMS-medium (2 g/l (NH 4 ) 2 SO 4 , 14 g/l K 2 HPO 4 , 6 g/l KH 2 PO 4 , 1 g/l tri-sodium citrate, 0.2 g/l MgSO 4 .7H 2 O; 1.5% agar (Becton Dickinson AG, Postfach, CH-4002 Basel, Switzerland) and trace elements (500-times concentrate: 5.0 g/l MnSO 4 ×1 H 2 O, 2.0 g/l COCl 2 .6H 2 O, 0.75 g/l (NH 4 ) 6 Mo 7 O 24 .4H 2 O, 0.5 g/l AlCl 3 .6H 2 O, 0.375 g/l CuCl.2H 2 O)). Colonies were visible after 24 to 48 h. All transformants were sensitive to neomycin indicating the replacement of the neomycin gene by the introduced wild-type and mutated tkt genes.
Genomic DNA was isolated from the transformants and the tkt gene was amplified by PCR as described in Example 1. The introduced mutations were confirmed by sequencing. No further nucleotide exchanges were observed. The generated B. subtilis strains were called:
R357A-BS3403, R357H-BS3482, R357K-BS3484, R357G-BS3512, R357V-BS3487, R357I-BS3509, R357L-BS3507, R357T-BS3492, R357S-BS3490, R357M-BS3505, R357N-BS3486, R357Q-BS3488.
EXAMPLE 6
Transduction of B. subtilis RB50::[pRF69] (EP 0405 370) with Bacteriophage PBS-1 Lysate of the Transketolase-Deficient Wild-Type Strain BS3402
Transduction work with phage PBS-1 was done as described in Henkin et al., 1984 (Henkin, T. M., and G. H. Chambliss. 1984. Genetic mapping of a mutation causing an alteration in Bacillus subtilis ribosomal protein S4. Mol Gen Genet 193:364-9). For preparation of the PBS-1 lysate, the strain BS3402 was grown on TBAB plates (5 μg/ml neomycin) at 37° C. overnight. The cells were used to inoculate 25 ml LB medium (Becton Dickinson AG, Postfach, CH-4002 Basel, Switzerland) to an OD of Klett 20-30 (using the green filter). When 50% of the cells were motile, 0.2 ml of the PBS-1 phage lysate (Henkin, T. M., and G. H. Chambliss. 1984. Genetic mapping of a mutation causing an alteration in Bacillus subtilis ribosomal protein S4. Mol Gen Genet 193:364-9) were added to 0.8 ml of the culture broth. After 30 min incubation at 37° C. under shaking, 9 ml LB-medium were added. This was followed by another 30 min incubation step at 37° C. Then 4 μg/ml chloramphenicol were added, and the incubation was continued for another 2 hours. Finally, the tubes were transferred into a 37° C. dry incubator where they were left overnight. On the next morning, the culture was filtered through a 0.45 μm filter and stored at 4° C. or directly used for transduction.
For the transduction of the riboflavin overproducing strain RB50::[pRF69], the strain was grown on a TBAB plate at 37° C. overnight. Cells of this plate were used to inoculate 25 ml LB-medium (Klett 20-30). When the culture reached Klett 175, 0.8 ml of the cells were mixed with 0.2 ml of a PBS-1 phage lysate from strain BS3402 prepared as described above. After 30 min incubation at 37° C. under shaking, cells were spun down and suspended in 1 ml VY medium. This was followed by 1 h incubation under the identical conditions. 200 to 1000 μl of the transduced cells were plated on a selection plate containing 2 μg/ml neomycin. Grown colonies were tested for neomycin resistance. After gDNA isolation (Example 1), a standard PCR using primer tkt 1S and Rec 2AS was done to confirm the replacement of the tkt wild-type gene by the construct of Example 4. A confirmed strain was called BS3523.
EXAMPLE 7
Introduction of the Modified Transketolase Genes into Strain BS3523
For preparation of PBS-1 lysates of strains BS3403, BS3482, BS3484, BS3486, BS3490, and BS3512, the respective strains were grown on TBAB plates (5 μg/ml neomycin) overnight at 37° C. Cells from those plates were used to inoculate 25 ml LB medium to an OD of Klett 20-30 (using the green filter). When 50% of the cells were motile (around Klett 150), 0.2 ml of the PBS-1 phage lysate (Henkin, T. M., and G. H. Chambliss. 1984.
Genetic mapping of a mutation causing an alteration in Bacillus subtilis ribosomal protein S4. Mol Gen Genet 193:364-9) were added to 0.8 ml of the culture broth. After 30 min incubation at 37° C. under slight shaking or turning (roller drum), 9 ml LB-medium were added to the cells. They were incubated for another 30 min under the same conditions. Chloramphenicol was added to a concentration of 4 μg/ml, and the incubation was continued for another 2 hours. The tubes were incubated overnight at 37° C. without shaking. On the next morning, the culture was filtered through a 0.45 μm filter and stored at 4° C. or directly used for subsequent transduction. For this, the transketolase-deficient strain BS3523 (see example 6) was grown on a TBAB plate overnight at 37° C. Cells from the plate were used to inoculate 25 ml LB-medium (Klett 20-30). The culture was incubated at 37° C. under shaking. When the culture reached Klett 175, 0.8 ml of the cells were mixed with 0.2 ml of PBS-1 phage lysate of each of the strains BS3403, BS3482, BS3484, BS3486, BS3490, and BS3512 as described above. After 30 min incubation at 37° C. under shaking, cells were spun down and suspended in 1 ml VY medium. After 1 h incubation under the identical conditions, the cells were spun down again, suspended in 0.2 ml 1×SMS medium and plated onto selection plates (1×SMS as described above with 1 g/l glucose, 1 g/l Sorbitol, and 15% agarose). Grown colonies were tested for loss of neomycin resistance. After gDNA isolation (Example 1), a standard PCR using primer tkt 1S and Rec 2AS was done to amplify the tkt gene from the genomic DNA. The tkt gene of colonies that showed a replacement of the inactivated tkt gene by an intact one, were sequenced to confirm the existence of the mutations. The generated strains were called BS3525 (BS3484 lysate), BS3528 (BS3482 lysate), BS3530 (BS3486), BS3534 (BS3403 lysate), BS3535 (BS3490 lysate), BS3541 (BS3512 lysate).
EXAMPLE 8
Growth of the Transketolase Mutant Strains on Glucose and Gluconate
To evaluate the effect of the transketolase mutations on viability and growth of B. subtilis , the maximal growth rate of the generated strains was determined on 2 g/l glucose or gluconate. The following medium was used: 1×SMS (2 g/l (NH 4 ) 2 SO 4 , 14 g/l K 2 HPO 4 , 6 g/l KH 2 PO 4 , 1 g/l tri-sodium citrate, 0.2 g/l MgSO 4 .7H 2 O), 2 g/l glucose or gluconate, 500 μg/l yeast extract and trace elements solution as described in Example 5. 25 ml of the described medium in a 300 ml flask with baffles were inoculated from an overnight culture (5 ml VY, resuspended in 1 ml fresh VY) to an OD of Klett 20 to 30. They were incubated at 37° C. under shaking (220 rpm). The OD of the cultures were followed in one hour intervals during the lag phase. During the logarithmic phase the interval was reduced to 30 min. At least four data points during the logarithmic phase were used for the determination of the maximal growth rate.
TABLE 1
B. subtilis
Growth rate
% wild
Growth rate
% wild
mutant
on glucose
type
on gluconate
type
ratio
Wild type
0.480
100%
0.351
100%
1.42/1
PY79
R357G
0.384
80%
0.300
86%
1.28/0.93
R357S
0.372
78%
0.254
72%
1.46/1.08
R357T
0.342
71%
0.240
68%
1.43/1.04
R357N
0.366
76%
0.231
66%
1.58/1.15
R357A
0.381
79%
0.225
64%
1.69/1.23
R357L
0.324
68%
0.189
54%
1.71/1.25
R357H
0.324
68%
0.174
50%
1.86/1.36
R357K
0.348
73%
0.171
49%
2.04/1.48
R357I
0.243
51%
0.108
31%
2.25/1.65
R357Q
0.228
48%
0.09
26%
2.53/1.83
R357V
0.297
62%
0.101
24%
2.94/2.58
R357M
0.258
54%
0.066
19%
3.91/2.84
R357Y
0.222
46%
0.06
17%
3.70/2.71
R357F
0.174
36%
0.038
11%
4.58/3.27
R357D
0.156
33%
0
0%
—
The wild-type strain PY79 showed as expected the highest growth rate on both substrates.
By introducing the different mutations at transketolase position 357, the growth on gluconate was, as expected, much more affected than the growth on glucose. Reduction of the maximal growth rate on gluconate was used as a measurement for the effect of the transketolase mutation on the flux through the non-oxidative pentose phosphate shunt and on the accumulation of the pentose phosphates. A wide range of growth rates were covered by the shown mutations.
EXAMPLE 9
Riboflavin Production in Shake Flasks
5 ml VY containing chloramphenicol (10 μg/ml) were inoculated with the riboflavin production strains RB50::[pRF69], BS32525, BS3528, BS34530, BS3434, BS34335, and BS3441 (see Example 7). After overnight incubation, the cells were spun down (15 min, 4000 rpm) and suspended in 1 ml screening medium (2×SMS, 10 g/l glucose, 1 g/l yeast extract, and trace elements as described in example 5). A 200 ml flask with baffles containing 25 ml screening medium was inoculated with 0.25 ml of the re-suspended cells. The cultures were incubated for 48 h at 37° C. in a water-saturated atmosphere. After 48 h incubation time, during which the supplied glucose was used up in all of the cultures, a sample of 0.5 ml was taken from the cultures, 35 μl 4 N NaOH was added and the mixture was vortexed for 1 min. 465 μl 1 M potassium phosphate buffer, pH 6.8, was added directly afterwards. The mixture was cleared by 5 min centrifugation at 14000 rpm (Eppendorf centrifuge 5415D). The supernatant was transferred into a new tube. Two different methods for riboflavin determination were used. For the calorimetric determination, 200 μl of the supernatant was diluted with 800 μl water. The absorption at 444 nm was multiplied with the factor of 0.03305 to obtain gram riboflavin per liter medium. For the final results, the obtained values were corrected for volume differences. The riboflavin concentration was also determined by HPLC according to Example 10. The results are shown in Table 2:
TABLE 2
HPLC
UV results
% of
results
% of
Riboflavin
RB50::
(riboflavin
RB50::
Strain
[mg/l]
[pRF69]
[mg/l]
[pRF69]
BS3528(R357H)
179
171%
139
193%
BS3535(R357S)
173
166%
136
188%
BS3534(R357A)
144
138%
124
172%
BS3525(R357K)
148
142%
112
155%
BS3559(R357Q)
134
129%
103
143%
BS3530(R357N)
126
120%
93
129%
RB50::[pRF69]
104
100%
72
100%
BS3541(R357G)
92
89%
66
92%
BS3523(deletion)
90
87%
58
81%
Nearly all Bacillus strains containing a transketolase mutation showed a clearly increased riboflavin production, while the transketolase negative strain produced less riboflavin than the control strain. In the case of the R357H mutation, the riboflavin concentration was nearly doubled.
EXAMPLE 10
Riboflavin Fermentation
Fermentation runs were performed as described in EP 405370.
Fermentations were run with strains (1) RB50::[pRF69], (2) BS3534 (R357A), and (3) BS3528 (R357H). At 24 hours and 48 hours fermentation time, concentrations of riboflavin and biomass (cell dry weight) were measured in the culture broth. As shown in Table 3, parent strain RB50::[pRF69] produced 9.8 g/l riboflavin in 48 h with a yield on substrate of 3.59% (w/w). Biomass was produced with a yield on substrate of 20.3% (w/w). Derivatives of RB50::[pRF69] expressing a modified transketolase gene showed significant increases in riboflavin production. BS3528 and BS3534 produced 11.7 g/l and 14.6 g/l, respectively. This corresponds to a yield on glucose of 4.23% with BS3528 and 5.14% with BS3534, respectively (Table 3). These results demonstrate that the modification of transketolase activity leads to an increase in riboflavin productivity.
TABLE 3
Riboflavin and biomass yield on substrate
after 48 h fermentation time
B2 Yield
Biomass Yield
[%] (w/w)
Difference
[%] (w/w)
Difference
RB50::[pRF69]
3.59 ± 0.27
20.26 ± 0.80
BS3534
5.14 ± 0.09
+43%
18.92 ± 0.37
−7%
BS3528
4.23 ± 0.19
+18%
17.78 ± 1.73
−12%
EXAMPLE 11
Analytical Methods for Determination of Riboflavin
For determination of riboflavin, the following analytical method can be used (Bretzel et al., J. Ind. Microbiol. Biotechnol. 22, 19-26, 1999).
The chromatographic system was a Hewlett-Packard 1100 System equipped with a binary pump, a column thermostat and a cooled auto sampler. Both a diode array detector and a fluorescence detector were used in line. Two signals were recorded, UV at 280 nm and fluorescence trace at excitation 446 nm, emission 520 nm.
A stainless-steel Supercosil LC-8-DB column (150×4.6 mm, 3 μm particle size) was used, together with a guard cartridge. The mobile phases were 100 mM acetic acid (A) and methanol (B). A gradient elution according to the following scheme was used:
Time [min]
% A
% B
0
98
2
6
98
2
15
50
50
25
50
50
The column temperature was set to 20° C., and the flow rate was 1.0 ml/min. The run time was 25 min.
Fermentation samples were diluted, filtered and analyzed without further treatment.
Riboflavin was quantitated by comparison with an external standard. The calculations were based on the UV signal at 280 nm. Riboflavin purchased from Fluka (9471 Buchs, Switzerland) was used as standard material (purity≧99.0%). | The present invention relates to a improved process for the biotechnological production of compounds for which ribose-5-phosphate, ribulose-5-phosphate or xylulose-5-phosphate is biosynthetic precursor like riboflavin (vitamin B 2 ), FAD, FMN, pyridoxal phosphate (vitamin B 6 ), guanosine, GMP, adenosine, AMP. The invention further pertains to the generation of the organism producing those compounds. It furthermore relates to the generation of mutated transketolases that allow normal growth on glucose but reduced growth on gluconate when introduced into the production strains and to polynucleotides encoding them. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of Ser. No. 13/127,832, filed on May 5, 2011 (published as US 20110213958), which is a 35 U.S.C. §371 National Phase Entry Application from PCT/IB2008/002973, filed Nov. 5, 2008, and designating the United States. The above identified applications and publications are incorporated by reference herein.
TECHNICAL FIELD
[0002] The present invention relates to IP multimedia subsystem (IMS) data security mechanisms.
BACKGROUND
[0003] Migration from circuit switched (CS) based networks to packet switched (PS) based networks (e.g., IMS based networks) will be done in steps, and the two networks may co-exist for a long time. A number of solutions have been standardized over the last years for enabling migration towards an IMS based infrastructure, such as, for example Voice Call Continuity (VCC). Most of these solutions allow a CS bearer to be used to carry speech traffic for a user, while providing the service control in IMS. The solutions may also allow the user to transfer traffic between CS bearers and PS bearers. With respect to media security, it is desired to provide a means for providing end-to-end media security in the case where the media traffic travels across both a CS network and a PS network.
SUMMARY
[0004] Aspects of the present invention provide a mechanism to utilize IMS media security mechanisms in a CS network and, thereby, provide end-to-end media security in the case where the media traffic travels across both a CS network and a PS network.
[0005] In one aspect, the invention provides a method performed by a gateway. In some embodiments, this method includes the following steps: establishing a circuit switched connection with a communication device; receiving from the communication device via the circuit switched connection a frame including a payload comprising an encrypted encoded data intended for a remote communication device and one or more encryption parameters (e.g., a counter value, an integrity tag, a key identifier) that is required by the remote communicate device to decrypt the encrypted encoded data; creating a protocol data unit that includes the encoded data and the encryption parameter; and transmitting via a packet switched network the protocol data unit so that it will be received by the remote communication device.
[0006] In some embodiments, the protocol data unit (PDU) (e.g., an SRTP PDU) includes a header portion and a payload portion, and the encoded data is placed in the payload portion and the encryption parameter is placed in the header portion. In some embodiments, the encoded data immediately follows or immediately precedes the encryption parameter in the frame. In some embodiments, the payload consist of the encrypted encoded data and the one or more encryption parameters.
[0007] In another aspect, the present invention provides an improved communication device (e.g., a mobile terminal). In some embodiments, the communication device includes: a key retrieving module configured to obtain or create an encryption key; a circuit switched connection establishment module for initiating a circuit switched connection; a payload creating module configured to produce a payload for a frame, wherein the payload includes encrypted encoded data and one or more encryption parameters; and a transmitter operable to transmit the frame to a gateway using the circuit switched connection. In some embodiments, the payload creating comprises an adaptive multi-rate (AMR) codec for producing the encoded data; and a security module configured to encrypt the encoded data and generate the frame payload. The key retrieving module may be operable to receive a message transmitted from the key management server, wherein the message includes the requested key. The key retrieving module may be further operable to transmit a message to a key management server, wherein the message includes a request for a key. In some embodiments, the key retrieving module is configured to transmit the message to the key management server using a short message service (SMS) or an Unstructured Supplementary Service Data (USSD) protocol.
[0008] In another aspect, the present invention provides a method performed by an application server. In some embodiments, the method includes the following steps: receiving at the application server a session initiation message transmitted from a mobile terminal, the session initiation message comprising a voucher (e.g., an encrypted key and/or other encryption information); storing the voucher included in the session initiation message; receiving at the application server a session initiation message transmitted from a gateway; determining whether the session initiation message transmitted from the gateway correlates with the session initiation message transmitted from the mobile terminal; retrieving the voucher in response to determining that the session initiation message transmitted from the gateway correlates with the session initiation message transmitted from the mobile terminal; and transmitting an session initiation message to another server after retrieving the voucher, wherein the session initiation message transmitted to the another server includes the voucher.
[0009] In some embodiments, the session initiation message transmitted from the mobile terminal is received via a packet switched network and includes information indicating that the mobile terminal shall use a circuit switched connection when communicating with the another terminal. In some embodiments, the step of determining whether the session initiation message transmitted from the gateway correlates with the session initiation message transmitted from the mobile terminal comprises determining whether information included in the session initiation message transmitted from the gateway matches information that was included in the session initiation message transmitted from the mobile terminal.
[0010] In another aspect, the present invention provides an application server for facilitating communications between a mobile terminal and another terminal. In some embodiments, the application server includes: a receiver operable to receive a session initiation message transmitted from the mobile terminal, the session initiation message comprising a voucher; a data storage unit for storing the voucher included in the session initiation message; a message correlating module configured to determine whether a session initiation message transmitted from a gateway correlates with the session initiation message transmitted from the mobile terminal; a voucher retrieving modules configured to retrieve the voucher in response to a determination that the session initiation message transmitted from the gateway correlates with the session initiation message transmitted from the mobile terminal; and a transmitter operable to transmit a session initiation message to another server after retrieving the voucher, wherein the session initiation message transmitted to the another server includes the voucher. In some embodiments, the receiver is operable to receive the session initiation message via a packet switched network, and the session initiation message includes information indicating that the mobile terminal shall use a circuit switched connection when communicating with the other terminal. Also, in some embodiments, the message correlating module is configured to determine whether the session initiation message transmitted from the gateway correlates with the session initiation message transmitted from the mobile terminal by determining whether information included in the session initiation message transmitted from the gateway matches information included in the session initiation message transmitted from the mobile terminal.
[0011] In other embodiments, the application server includes: a receiver operable to receive from a gateway an initiation message indicating that the mobile terminal has requested establishment of a secure session with the other terminal; a key management module configured to retrieve a voucher from a key management system in response to the receiver receiving the initiation message from the gateway; and a transmitter operable to transmit the retrieved voucher to another application server in response to the key management module retrieving the voucher.
[0012] In yet other embodiments, the application server includes: a receiver operable to receive a key request message transmitted from the mobile terminal; a key management module configured to transmit a key to the mobile terminal in response to receipt of the key request message; a data storage unit for storing the key; an initiation message transmitting module configured to (a) determine whether the stored key is associated with information that matches information included in an initiation message transmitted from a gateway and (b) in response to determining that that the stored key is associated with information that matches information included in the initiation message transmitted from the gateway, transmit to another server an initiation message. In some embodiments, the key management module is further configured, such that, in response to receipt of the key request message and prior to transmitting the key to the mobile terminal, the key management module obtains the key from a key management system.
[0013] The above and other aspects and embodiments are described below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements.
[0015] FIG. 1 illustrates a system according to an embodiment of the invention.
[0016] FIG. 2 further illustrate the system shown in FIG. 1 .
[0017] FIGS. 3-8 are data flow diagrams illustrating different embodiments of the invention.
[0018] FIGS. 9-11 are flow charts illustrating various processes according to different embodiments of the invention.
[0019] FIG. 12 is a functional block diagram of a gateway according to an embodiment of the invention.
[0020] FIGS. 13 and 14 are functional block diagrams of a UE according to an embodiment of the invention.
[0021] FIG. 15 is a functional block diagram of an application server according to an embodiment of the invention.
DETAILED DESCRIPTION
[0022] Referring now to FIG. 1 , FIG. 1 illustrates a system 100 according to some embodiments of the invention. As shown, system 100 includes a communication device 102 (a.k.a., user equipment (UE) 102 ) that is operable to communicate with components of a network 101 . As shown in FIG. 1 , UE 102 , which may be a mobile terminal, is operable to communicate with a “gateway” 104 using a circuit switched (CS) network and is operable to communicate with an “application server” 106 using a packet switched network (PS). As further shown, gateway 104 and application server 106 can communicate with each other using a PS network. Additionally, gateway 104 and application server 106 may be able to send messages to and receive messages from a remote network 110 using a PS network. Accordingly, gateway 104 functions to enable UE 102 to communicate with devices connected to remote network 110 by using both a CS connection and a PS connection.
[0023] Referring now to FIG. 2 , FIG. 2 further illustrates system 100 . As illustrated in FIG. 2 , gateway 104 may includes one or more servers. For example, as shown, gateway 104 may include a switching center server 212 (e.g., a Mobile Switching Center) and a gateway server 214 (e.g., a media gateway (MGW)). As also illustrated, application server 106 may include one or more severs (e.g., one or more Session Initiation Protocol (SIP) servers). For example, as shown, application server 106 may include a proxy Call Session Control Function (P-CSCF) server 222 , a serving CSCF (S-CSCF) 224 , and a Service Centralization and Continuity Application Server (SCC AS) server. As further shown, system 100 may also include a Short Message Service Center (SMSC) 202 and a key management system 204 , both of which may be components of network 101 .
[0024] Referring now to FIG. 3 , FIG. 3 is a data flow diagram illustrating a process, according to an embodiment of the invention, for enabling UE 102 (e.g., a mobile terminal such as a mobile phone) to originate a call (e.g., a voice call) with a device connected to network 110 and to communicate with the device utilizing both a CS network (e.g., a wireless CS radio access network) and a PS network in a secure manner. In this embodiment, the UE 102 has the capability of communicating with application server 106 using nothing but a PS network and has the capability of establishing a CS call with gateway 104 .
[0025] As illustrated in FIG. 3 , the process may begin with UE 102 transmitting to application server 106 a message 302 (e.g., an SIP invite message or other session initiation message) via a PS network. Message 302 may include the following information: (1) information identifying the called party, (2) encryption key management information (e.g., an encryption key and/or other information necessary to secure the communications), which may be referred to herein as a “voucher”, (3) information indicating that UE 102 will use a CS bearer to connect with network 101 ; and (4) information identifying UE 102 and/or the user of UE 102 . In some embodiments, prior to UE 102 transmitting message 302 , UE obtains encryption key management information from KMS 204 and/or creates the encryption key management information.
[0026] In response to message 302 , server 106 may transmit a response message 304 to UE 102 . Because message 302 indicates that UE will use a CS bearer to connect with network 101 , application server 106 waits to receive a particular message 308 from gateway 104 before transmitting a message 310 to remote network 110 . Additionally, in response to receiving message 302 , server 106 stores the voucher and associates the voucher with the information identifying the called party and the information identifying UE 102 and/or the user of UE 102 .
[0027] In response to receiving message 304 from server 106 , UE 102 transmits a call setup request 306 to gateway 104 . In response, gateway 104 transmits message 308 to application server 106 , which message indicates to server 106 that UE 102 has established (or is about to establish) a connection with gateway 104 using a CS bearer. Message 304 may include the following information: (1) information identifying UE 102 and/or the user of UE 102 and (2) information identifying the called party.
[0028] In response to receiving message 308 , server 106 correlates the message 302 with message 308 . For example, server 106 uses the information included in message 308 (i.e., the information identifying UE 102 and/or the user of UE 102 and the information identifying the called party) to retrieve the voucher it had previously received from UE 102 . After retrieving the voucher, server 106 transmits to remote network 110 message 310 (e.g., an initiation message, such as, for example, a SIP invite message), which includes the retrieved voucher. After server 106 transmits message 310 additional messages may be transmitted to complete the set-up of the session and bearers, as is well known in the art.
[0029] After the session and bearers are set-up, UE 102 may begin transmitting fames of encrypted data (e.g., frames of encrypted voice data) to gateway 104 using the CS bearer 312 . Preferably, the frames include not only the encrypted data but also encryption parameters needed by the called party to decrypt the encrypted data. For example, the encryption parameters may include a sequence number (a.k.a., counter value), an integrity tag, and a key identifier (e.g., an SRTP master key identifier (MKI)). An exemplary payload 1306 of the frame is illustrated in FIG. 13 .
[0030] Gateway 104 is configured to receive the frames and for each frame, extract the encrypted data and encryption parameters from the frame, create a secure real-time transport protocol (SRTP) protocol data unit (“SRTP packet”) that includes the encrypted data and encryption parameters, and transmit the SRTP packet to remote network 110 so that the data is ultimately received by the called party. In this manner, end-to-end media security is established between UE 102 and remote network 110 even though UE 102 connects to network 101 using a CS bearer.
[0031] Referring now to FIG. 4 is a data flow diagram illustrating a process, according to an embodiment of the invention, for enabling UE 102 to terminate a call (e.g., a voice call) from a device connected to network 110 and to communicate with the device utilizing both a CS network and a PS network in a secure manner. In this embodiment, the UE 102 has the capability of communicating with application server 106 using nothing but a PS network and has the capability of establishing a CS call with gateway 104 .
[0032] As illustrated in FIG. 4 , the process may begin with server 106 receiving from remote network 110 a message 402 (e.g., an initiation message) via a PS network. Message 402 may include the following information: (1) information identifying the called party (i.e., UE 102 ), (2) a voucher; and (3) information identifying the calling device or the user of the calling device. In response to receiving message 402 , server 106 transmit to UE 102 a message 404 (e.g., an initiation message), which contains the voucher.
[0033] In response to message 404 , UE 102 transmits a call setup request 406 to gateway 104 . In response, gateway 104 transmits to application server 106 a message 408 (e.g., an initiation message), which message may include the following information: (1) information identifying UE 102 and/or the user of UE 102 and (2) information identifying the calling party.
[0034] In response to receiving message 408 , server 106 determines that message 408 is correlated with message 402 . In response to this determination, server 106 transmits to network 110 a response message 410 , which is a response to message 402 . After server 106 transmits response message 410 , additional messages may be transmitted to complete the set-up of the session and bearers, as is well known in the art.
[0035] After the session and bearers are set-up, UE 102 may begin transmitting fames of encrypted data (e.g., frames of encrypted voice data) to gateway 104 using the CS bearer 412 . Preferably, the frames include not only the encrypted data but also the encryption parameters needed by the called party to decrypt the encrypted data. Gateway 104 , as described above, receives the frames and, for each frame, extracts the encrypted data and encryption parameters from the frame, creates an SRTP packet that includes the encrypted data and encryption parameters, and transmit the SRTP packet to remote network 110 so that the data is ultimately received by the calling party. In this manner, end-to-end media security is established between UE 102 and remote network 110 even though UE 102 connects to network 101 using a CS bearer.
[0036] Referring now to FIG. 5 , FIG. 5 is a data flow diagram illustrating a process, according to an embodiment of the invention, for enabling UE 102 to originate a call (e.g., a voice call) with a device connected to network 110 and to communicate with the device utilizing both a CS network and a PS network in a secure manner. In this embodiment, the UE 102 does not have the capability of communicating with application server 106 using a PS network, but has the capability of establishing a CS call with gateway 104 .
[0037] As illustrated in FIG. 5 , the process may begin with UE 102 transmitting to KMS 204 a key request message 502 . Message 502 may be a short message service (SMS) message, an Unstructured Supplementary Service Data (USSD) message, or other like message. KMS 204 , in response to message 502 , transmits to UE 102 a message 504 that includes an encryption key. In response to message 504 , UE 102 transmits to gateway 104 a call setup request 506 . In response, gateway 104 transmits to application server 106 a message 508 (e.g., an initiation message), which message may include the following information: (1) information identifying UE 102 and/or the user of UE 102 and (2) information identifying the called party. Message 508 may also include information indicating that a secure session should be established.
[0038] After receiving message 508 , server 106 determines whether the message includes information indicating that a secure session should be established. If server 106 determines that a secure session should be established, server 106 transmits to KMS 204 a request message 510 (e.g., a request for a voucher), which includes information identifying UE 102 and/or the user of UE 102 . In response to message 510 , KMS 204 transmits to server 106 a voucher 512 containing the key (e.g., an encrypted version of the key) that KMS 204 transmitted to UE 102 in message 504 . In response to receiving message 512 , server 106 transmits to network 110 a message 514 (e.g., an initiation message) that includes the voucher received from KMS 204 .
[0039] After server 106 transmits message 514 , additional messages may be transmitted to complete the set-up of the session and bearers, as is well known in the art. After the session and bearers are set-up, UE 102 may begin transmitting fames of encrypted data (e.g., frames of voice data encrypted using the key received from KMS 204 ) to gateway 104 using the CS bearer 516 . Preferably, the frames include not only the encrypted data but also the encryption parameters needed by the called party to decrypt the encrypted data. Gateway 104 , as described above, receives the frames and, for each frame, extracts the encrypted data and encryption parameters from the frame, creates an SRTP packet that includes the encrypted data and encryption parameters, and transmits the SRTP packet to remote network 110 so that the data is ultimately received by the called party. In this manner, end-to-end media security is established between UE 102 and remote network 110 even though UE 102 connects to gateway 104 using CS bearer 512 .
[0040] Referring now to FIG. 6 is a data flow diagram illustrating a process, according to an embodiment of the invention, for enabling UE 102 to terminate a call (e.g., a voice call) from a device connected to network 110 and to communicate with the device utilizing both a CS network and a PS network in a secure manner. In this embodiment, the UE 102 does not have the capability of communicating with application server 106 using a PS network, but has the capability of establishing a CS call with gateway 104 .
[0041] As illustrated in FIG. 6 , the process may begin with server 106 receiving from remote network 110 a message 602 (e.g., an initiation message) via a PS network. Message 602 may include the following information: (1) information identifying the called party (i.e., UE 102 ), (2) a voucher; and (3) information identifying the calling device or the user of the calling device. In response to receiving message 602 , server 106 (a) transmits to gateway 604 a message 604 (e.g., an initiation message), which may include information indicating that a secure session should be established and (b) transmits to KMS 204 a message 608 containing the voucher and information identifying UE 102 and/or the user of UE 102 and information identifying the calling party.
[0042] In response to message 604 , gateway 104 transmits to UE 102 a call setup request 606 . In response, UE 102 may transmit to KMS 204 (via SMS or USSD) a message 610 requesting the keys for the session. KMS 204 , in response to message 610 or in response to message 608 , transmits to UE 102 (via SMS or USSD) the requested keys and possibly also the voucher in message 612 .
[0043] After transmitting to UE 102 , the call set-up message 606 , gateway 104 transmits to server 106 a response 614 to message 604 . In response to receiving message 614 , server 106 transmits to network 110 a response to message 602 .
[0044] After server 106 transmits response message 614 , additional messages may be transmitted to complete the set-up of the session and bearers, as is well known in the art. After the session and bearers are set-up, UE 102 may begin transmitting fames of encrypted data (e.g., frames of voice data encrypted using a key included in the voucher received from KMS 204 ) to gateway 104 using the CS bearer 618 . Preferably, the frames include not only the encrypted data but also the encryption parameters needed by the called party to decrypt the encrypted data. Gateway 104 , as described above, receives the frames and, for each frame, extracts the encrypted data and encryption parameters from the frame, creates an SRTP packet that includes the encrypted data and encryption parameters, and transmits the SRTP packet to remote network 110 so that the data is ultimately received by the calling party. In this manner, end-to-end media security is established between UE 102 and remote network 110 even though UE 102 connects to gateway 104 using CS bearer 618 .
[0045] Referring now to FIG. 7 , FIG. 7 is a data flow diagram illustrating a process, according to an embodiment of the invention, for enabling UE 102 to originate a call (e.g., a voice call) with a device connected to network 110 and to communicate with the device utilizing both a CS network and a PS network in a secure manner. In this embodiment, the UE 102 has the capability of communicating with application server and has the capability of establishing a CS call with gateway 104 .
[0046] As illustrated in FIG. 7 , the process may begin with UE 102 transmitting to application server 106 a key request message 702 . Message 702 may include (1) information identifying UE 102 and/or the user of UE 102 and (2) information identifying the called party. In response to message 702 , server 106 transmits to KMS 204 a key request message 704 . In response to message 704 , KMS 204 transmits to server 106 a message 706 containing a key and a voucher.
[0047] After receiving message 706 , server 106 (a) stores the voucher and associates the stored voucher with information identifying UE 102 and/or the user of UE 102 and (2) information identifying the called party and (b) transmits to UE 102 a message 708 in response to message 702 . Message 708 includes the key received from KMS 204 . After receiving message 708 from server 106 , UE 102 transmits a call setup request 710 to gateway 104 . In response, gateway 104 transmits message 712 (e.g., an initiation message) to application server 106 , which message indicates to server 106 that UE 102 has established (or is about to establish) a connection with gateway 104 using a CS bearer. Message 712 may include the following information: (1) information identifying UE 102 and/or the user of UE 102 and (2) information identifying the called party.
[0048] In response to receiving message 712 , server 106 correlates the key request message 702 with message 712 . For example, server 106 uses the information included in message 712 (i.e., the information identifying UE 102 and/or the user of UE 102 and the information identifying the called party) to retrieve the voucher it had previously received from KMS 204 . After retrieving the voucher, server 106 transmits to remote network 110 a message 714 (e.g., an initiation message), which includes the retrieved voucher.
[0049] After server 106 transmits message 714 additional messages may be transmitted to complete the set-up of the session and bearers, as is well known in the art. After the session and bearers are set-up, UE 102 may begin transmitting fames of encrypted data (e.g., frames of voice data encrypted using the key received from server 106 ) to gateway 104 using the CS bearer 716 . Preferably, the frames include not only the encrypted data but also the encryption parameters needed by the called party to decrypt the encrypted data. Gateway 104 , as described above, receives the frames and, for each frame, extracts the encrypted data and encryption parameters from the frame, creates an SRTP packet that includes the encrypted data and encryption parameters, and transmits the SRTP packet to remote network 110 so that the data is ultimately received by the calling party. In this manner, end-to-end media security is established between UE 102 and remote network 110 even though UE 102 connects to gateway 104 using CS bearer 716 .
[0050] Referring now to FIG. 8 , FIG. 8 is a data flow diagram illustrating a process, according to an embodiment of the invention, for enabling UE 102 to terminate a call (e.g., a voice call) from a device connected to network 110 and to communicate with the device utilizing both a CS network and a PS network in a secure manner. In this embodiment, the UE 102 has the capability of communicating with application server and has the capability of establishing a CS call with gateway 104 .
[0051] As illustrated in FIG. 8 , the process may begin with server 106 receiving from network 110 a message 802 (e.g., an initiation message). Message 802 may include (1) information identifying UE 102 and/or the user of UE 102 , (2) information identifying the calling party, and (3) a voucher that contains an encrypted key. In response to message 802 , server 106 transmits to KMS 204 a key request message 804 , which includes the voucher. In response to message 804 , KMS 204 transmits to server 106 a message 806 containing the key included in the voucher.
[0052] After receiving message 806 , server 106 transmits to UE 102 a message 808 . Message 808 includes the key received from KMS 204 and indicates to UE 102 that a party is calling UE 102 . After receiving message 808 from server 106 , UE 102 transmits a call setup request 810 to gateway 104 . In response, gateway 104 transmits message 812 (e.g., an initiation message) to application server 106 , which message indicates to server 106 that UE 102 has established (or is about to establish) a connection with gateway 104 using a CS bearer. Message 812 may include the information that enables server 106 to correlate message 812 with message 802 .
[0053] In response to receiving message 812 , server 106 correlates message 802 with message 812 and transmits to remote network 110 a response message 814 . After server 106 transmits response message 814 , additional messages may be transmitted to complete the set-up of the session and bearers, as is well known in the art. After the session and bearers are set-up, UE 102 may begin transmitting fames of encrypted data (e.g., frames of voice data encrypted using the key received from server 106 ) to gateway 104 using the CS bearer 816 . Preferably, the frames include not only the encrypted data but also the encryption parameters needed by the called party to decrypt the encrypted data. Gateway 104 , as described above, receives the frames and, for each frame, extracts the encrypted data and encryption parameters from the frame, creates an SRTP packet that includes the encrypted data and encryption parameters, and transmits the SRTP packet to remote network 110 so that the data is ultimately received by the calling party. In this manner, end-to-end media security is established between UE 102 and remote network 110 even though UE 102 connects to gateway 104 using CS bearer 816 .
[0054] Referring now to FIG. 9 , FIG. 9 is a flow chart illustrating a process performed by gateway 104 , according to some embodiments. The process may begin in step 902 , where gateway 104 establishes a CS connection with UE 102 (e.g., gateway 104 terminates a CS call initiated by UE 102 or originates a CS call to UE 102 ). In step 904 , gateway 104 receives from UE 102 via the CS connection a frame that includes encrypted encoded data intended for a remote device and one or more encryption parameters that are needed by the remote device to decrypt the encoded data. In step 906 , gateway 104 creates a protocol data unit (e.g., an SRTP protocol data unit) that includes the encrypted encoded data and the encryption parameter(s). For example, the encrypted encoded data may be placed in a payload portion of the SRTP packet and the encryption parameter(s) may be placed in a header portion of the packet. In step 908 , gateway 104 transmits the packet so that it will be received by the remote device. In this manner, gateway 104 functions to map secure media from CS domain to the SRTP domain, thereby enabling end-to-end security even though UE 102 access network 101 using the CS technology and not PS technology.
[0055] Referring now to FIG. 10 , FIG. 10 is a flow chart illustrating another process performed by gateway 104 , according to some embodiments. The process may begin in step 1002 , where gateway 104 establishes a CS connection with UE 102 . In step 1004 , gateway 104 receives from a remote device an SRTP packet containing encrypted data and one or more encryption parameter(s) (e.g., a sequence number). The encrypted data is stored in a payload portion of the packet and the encryption parameter is stored in a header of the packet. In step 1006 , gateway 104 transmits to UE 102 via the CS connection a frame containing the encrypted data and encryption parameters, where the encrypted data and encryption parameter are included in the same payload portion of the packet. In some embodiments, the payload portion of the frame consists of (or consists essentially of) the encrypted data and encryption parameters.
[0056] Referring now to FIG. 11 , FIG. 11 is a flow chart illustrating a process performed by UE 102 , according to some embodiments. The process may begin in step 1102 , where UE 102 transmits a key request. For example, in step 1102 , UE 102 may send to KMS 204 an SMS/USSD message that includes a request for a key or UE 102 may send to server 106 , via a CS network, a message that includes a request for a key. In step 1104 , UE 102 receives a key in response to the key request. For example, in step 1104 , UE 102 may receive the key from the KMS via an SMS/USSD message or may receive the key, via a CS network, from server 106 . In step 1106 , UE 102 , establishes a CS connection with gateway 104 (e.g., UE 102 transmit a CS call set up message to MSC server 212 ). In step 1108 , UE 102 obtains or generates media (e.g., voice data) to be transmitted securely to a remote device via the CS connection. In step 1110 , UE 102 encodes the media and then encrypts the encoded media using a key received in step 1104 . In step 1112 , UE 102 creates a secure data frame that includes the encrypted encoded data and one or more encryption parameters (e.g., a counter value and an integrity protection tag). In step 1114 , UE 102 transmits the secure data frame to gateway 104 using the CS connection. In step 1116 , UE 102 receives a frame transmitted from gateway 104 using the CS connection, which frame has a payload portion that includes encrypted encoded data and one or more encryption parameters. In step 1118 , UE 102 uses a key received in step 1104 and the encryption parameters included in the frame to decrypt the encrypted data included in the frame, decodes the encoded data to produce decoded data, and then outputs the decoded data (e.g., in the case the data includes an audio signal, the data may be provided to a speaker included in the UE to produce a sound wave corresponding to the audio signal and in the case the data includes a video signal, the data may be provided to a driver that drives a display of the UE so that the video can be reproduced on the UE's display).
[0057] Referring now to FIG. 12 , FIG. 12 is a functional block diagram of gateway 104 according to some embodiments of the invention. As shown, gateway 104 may comprise a data processing system 1202 (e.g., one or more microprocessors), a data storage system 1206 (e.g., one or more non-volatile storage devices) and computer software 1208 stored on the storage system 1206 . Configuration parameters 1210 may also be stored in storage system 1206 . Gateway 102 also may comprise transmit/receive (Tx/Rx) circuitry 1204 for transmitting frames to and receiving frames from UE 102 and transmit/receive (Tx/Rx) circuitry 1205 for transmitting packets to and receiving packets from network 110 .
[0058] Software 1208 is configured such that when processor 1202 executes software 1208 , gateway 104 performs steps described herein. For example, software 1208 may include: ( 1 ) a connection establishing module for establishing a circuit switched connection with a communication device (e.g., UE 102 ); a receiving module for receiving from the communication device via the circuit switched connection a frame including encrypted encoded data intended for a remote communication device and an encryption parameter that is required by the remote communicate device to decrypt the encrypted encoded data; a protocol data unit creating module for creating a protocol data unit that includes the encoded data and the encryption parameter; and a transmitting module for transmitting, via a packet switched network, the protocol data unit so that it will be received by the remote communication device.
[0059] Referring now to FIG. 13 , FIG. 13 is a functional block diagram of UE 102 according to some embodiments. In the embodiment illustrated, UE 102 includes a data generator 1301 , a codec 1302 , a security module 1304 and a transmit/receive circuit 1308 for transmitting and receiving data. Data generator 1301 may include a microphone for converting sound waves (e.g., speech) to an electrical signal, an amplifier for amplifying the signal, and an analog to digital converter for converting the continuous electrical signal to a digital signal. The data generated by generator 1301 is input into codec 1302 (e.g., a speech codec such as the adaptive multi-rate (AMR) codec) that produces encoded data 1303 . Encoded data 1303 is an input to a security module 1304 . Security module 1304 is configured to encrypt the encoded data using an encryption key and is configured to form a fame payload 1306 that contains one or more encryption parameters and the encrypted encoded data. In the embodiment illustrated, the frame payload 1306 of the frame includes only the encrypted data and the encryption parameters. Payload 1306 is then obtained by transmitter 1308 , which is configured to include payload 1306 in a frame and transmit the frame using a CS connection.
[0060] While security module 1304 is shown as being separate and distinct from codec 1302 , this is not a requirement. It is contemplated that codec 1302 can be configured to perform not only normal encoding operations, but also the functions of security module 1304 .
[0061] Codec 1302 and/or security module 1304 may be implemented in software and/or hardware. Accordingly, UE 102 may include (i) a data storage system 1406 for storing encryption keys, encryption parameters 1410 , and software 1408 for implementing codec 1302 and/or module 1304 and (ii) a processor 1402 for executing the software (see FIG. 14 ). UE 102 may also have an antenna 1420 .
[0062] Referring now to FIG. 15 , FIG. 15 is a functional block diagram of application server 226 according to some embodiments of the invention. As shown, server 226 may comprise a data processing system 1502 (e.g., one or more microprocessors), a data storage system 1506 (e.g., one or more non-volatile storage devices) and computer software 1508 stored on the storage system 1506 . Configuration parameters 1510 may also be stored in storage system 1506 . Server also may comprise transmit/receive (Tx/Rx) circuitry 1504 for communicating with other servers and clients.
[0063] Software 1508 is configured such that when processor 1502 executes software 1508 , server 226 performs steps described herein. For example, software 1508 may include: (1) an initiation message receiving module for receiving an initiation message (e.g., a SIP invite message or other initiation message) transmitted from UE, (2) a voucher storing module for storing a voucher included in the initiation message; (3) a voucher retrieving module for retrieving the voucher in response to receiving from gateway 104 an initiation message that correlates with an earlier initiation message received from UE 102 ; (4) an initiation creating and transmitting module for creating and transmitting an initiation message to network 110 in response to receiving from gateway 104 the initiation message that correlates with the earlier initiation message received from UE 102 ; (5) an initiation message receiving module for receiving an initiation message transmitted from network 110 which initiation message identifies UE 102 as a called party; (6) an initiation transmitting module for transmitting an initiation message to UE 102 in response to receiving the initiation message from network 110 ; (7) an initiation response creating and transmitting module for creating and transmitting an initiation response message to network 110 in response to receiving from gateway 104 an initiation message that correlates with the earlier initiation message received from network 110 ; (8) a voucher requesting module for transmitting a voucher request to KMS 204 in response to receiving an initiation message from gateway 104 ; and (9) an initiation message transmitting module for transmitting to network 110 an initiation message containing a voucher received from KMS 204 .
[0064] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.
[0065] Additionally, while the processes described above and illustrated in the drawings are shown as a sequence of steps, this was done solely for the sake of illustration. Accordingly, it is contemplated that some steps may be added, some steps may be omitted, and the order of the steps may be re-arranged. | Aspects of the present invention provide a mechanism to utilize IMS media security mechanisms in a CS network and, thereby, provide end-to-end media security in the case where the media traffic travels across both a CS network and a PS network. | 7 |
This application is a continuation-in-part of U.S. application Ser. No. 08/992,478 filed Dec. 17, 1997, now U.S. Pat. No. 6,203,756.
BACKGROUND OF THE INVENTION
This invention relates to systems and processes for chemical sterilizing or disinfecting medical devices.
Medical instruments have traditionally been sterilized or disinfected using either heat such as is provided by steam, or a chemical in liquid, gas, or vapor state. Prior to sterilization or disinfection, the instruments to be treated are usually first cleaned and then sterilized or disinfected. After sterilization or disinfection with a liquid chemical germicide, purified water is used to rinse the instruments and then the instruments are dried. Numerous publications regarding the cleaning of medical devices and the sterilizing of medical devices are available.
U.S. Pat. No. 5,443,801 discloses a transportable cleaning/sterilizing apparatus and method for inside-outside washing and sterilization of medical/dental instruments. The apparatus functions in four sequential cycles: wash, rinse, sterilize, and dry. The sterilization step is conducted using ozonated and purified water, and the drying step is accomplished by injecting ozonated/deozonated sterile warm dry oxygen, or sterile inert gas into and exhausted from the wash chamber under a positive pressure relative to atmospheric. In this process, the device has to be rinsed with purified water after it is sterilized to remove sterilant residue before drying step.
U.S. Pat. No. 5,505,218 to Steinhauser et al. discloses a device for cleaning, disinfecting and maintaining medical or dental instruments. The device has a pot-shaped container with a multiplicity of mountings in the interior of the container each for one of tool holder, a water supply system, a compressed air supply system, and an ultrasonic transducer. The disinfection is conducted with heated water, and the drying is conducted with hot compressed air. This system is not designed for sterilization.
U.S. Pat. No. 5,279,799 to Moser et al. discloses apparatus for cleaning and testing endoscopes by injecting pressurized air into the sheath and pressurized air and washing liquid into the ducts. A washing chamber is provided which contains retractable cages to hold the endoscopes during cleaning and testing. This process includes washing, disinfecting, final rinsing with purified water, and air drying the ducts of a tubular article. A number of filters are involved in this system, and this system is not designed for sterilization.
U.S. Pat. No. 4,744,951 to Cummings et al. discloses a two-chambered system which provides hydrogen peroxide in vapor form for use in sterilization processes. The sterilant is initially vaporized in one chamber and then applied to the object to be sanitized in another single sterilizing chamber, thereby producing a concentrated hydrogen peroxide vapor which is relatively more effective. The sterilization processes are designed for furnishing concentrated hydrogen peroxide vapor to interior surfaces of articles having a tortuous or a narrow path. However, the sterilization processes are ineffective at rapidly sterilizing lumened devices, since they depend on the diffusion of the hydrogen peroxide vapor into the lumen to effect sterilization.
U.S. Pat. No. 4,863,688 to Schmidt et al. discloses a sterilization system consisting of a liquid hydrogen peroxide vaporization chamber and an enclosure for sterilization. The enclosure additionally may hold containers wherein the hydrogen peroxide sterilant vapor does not contact the interior of the containers. This system is designed for controlling the exposure to the hydrogen peroxide vapor. The system is not designed for sterilizing a lumen device.
U.S. Pat. No. 4,943,414, entitled “Method for Vapor Sterilization of Articles Having Lumens,” and issued to Jacobs et al., discloses a process in which a vessel containing a small amount of a vaporizable liquid sterilant solution is attached to a lumen, and the sterilant vaporizes and flows directly into the lumen of the article as the pressure is reduced during the sterilization cycle. This system has the advantage that the water and hydrogen peroxide vapor are pulled through the lumen by the pressure differential that exists, increasing the sterilization rate for lumens, but it has the disadvantage that the vessel needs to be attached to each lumen to be sterilized.
U.S. Pat. Nos. 4,937,046, 5,118,471 and 5,227,132 to Anderson et al. each disclose a sterilization system which uses ethylene oxide gas for sanitation purposes. The gas is initially in a small first enclosure and thereafter slowly permeates into a second enclosure where the objects to be sterilized are located. A medium is then introduced into the second enclosure to flush out the sterilizing gas into a third enclosure containing the second enclosure. An exhaust system then exhausts the sterilant gas and air from the third enclosure. These systems also have the disadvantage of relying on the diffusion of the sterilant vapor to effect sterilization and hence are not suitable for rapidly sterilizing lumened devices.
U.S. Pat. No. 5,122,344 to Schmoegner discloses a chemical sterilizer system for sterilizing items by vaporizing a liquid chemical sterilant in a sterilizing chamber. Pre-evacuation of the sterilizer chamber enhances the sterilizing activity. Sterilant is injected into the sterilizer chamber from a second prefilled shot chamber. This system also relies upon diffusion of sterilant vapor to effect sterilization and is also not suitable for rapidly sterilizing lumened devices.
U.S. Pat. No. 5,266,275 to Faddis discloses a sterilization system for disinfecting instruments. The sterilization system contains a primary sterilization chamber and a secondary safety chamber. The secondary safety chamber provides for sensing and venting to a destruction chamber any sterilization agent that is released from the primary sterilization chamber. This system, as in other systems, also relies upon diffusion of sterilant vapor to effect sterilization and is also not suitable for rapidly sterilizing lumened devices.
In U.S. Pat. Nos. 5,492,672 and 5,556,607 to Childers et al, there is disclosed a process and apparatus respectively for sterilizing narrow lumens. This process and apparatus uses a multicomponent sterilant vapor and requires successive alternating periods of flow of sterilant vapor and discontinuance of such flow. A complex apparatus is used to accomplish the method. Additionally, the process and apparatus of '672 and '607 require maintaining the pressure in the sterilization chamber at a predetermined subatmospheric pressure.
In U.S. Pat. No. 5,527,508 to Childers et al., a method of enhancing the penetration of low vapor pressure chemical vapor sterilants into the apertures and openings of complex objects is disclosed. The method repeatedly introduces air or an inert gas into the closed sterilization chamber in an amount effective to raise the pressure to a subatmospheric pressure to drive the diffused sterilant vapor further into the article to achieve sterilization. The '508, '672 and '607 Childers inventions are similar in that all three require repeated pulsations of sterilant vapor flow and maintenance of the sterilization chamber pressure at a predetermined subatmospheric pressure.
One disadvantage of the cleaning/sterilizing or cleaning/disinfecting systems of the prior art as discussed above is that, after the device is sterilized or disinfected and before it is dried, the device has to be rinsed with purified water to remove disinfectant or sterilant residues. A so-called bacteria filter is usually used to filter the water to remove particulates and bacteria. Typically, a two-stage filtering system is utilized, for example, a first stage has a 2-5 micron filter and a second stage has a 0.1-0.2 micron filter. However, virus can be smaller than 0.1 micron. This means the virus can penetrate the filtering system recontaminating the sterilized device in the final rinsing process. Another problem associated with the use of a bacteria filter is that bacteria can form biofilms in the filter which are difficult to sterilize and, thus, become a new potential source of contamination. In U.S. Pat. No. 6,103,189 to Kralovic attempts to solve the problem of getting sterile water by using a dilute solution of the sterilant to rinse the devices. This has the potential to leave residual sterilant on the devices.
In consideration of the foregoing, no simple, safe, effective method of cleaning, sterilizing or disinfecting, drying devices with an integrated process and with the sterilizing (or disinfecting) and drying being conducted simultaneously exists in the prior art. Thus, there remains a need for a simple and effective process and apparatus for efficiently cleaning, sterilizing or disinfecting, and drying medical devices, especially those with long narrow lumens.
SUMMARY OF THE INVENTION
An apparatus, according to the present invention, disinfects or sterilizes a medical device without a filtering system for providing a sterile water. The apparatus consists essentially of a source of liquid disinfectant or sterilant and a chamber adapted to receive the medical device. The chamber has one or more ports, at least one of which has a valve, for introducing or removing the liquid disinfectant or sterilant into or out of the chamber.
Preferably, the liquid disinfectant or sterilant comprises hydrogen peroxide.
In another aspect of the present invention, an apparatus for disinfecting or sterilizing a medical device comprises a source of liquid disinfectant or sterilant, a chamber adapted to receive the medical device and one or more ports, at least one of which has a valve, on the chamber for introducing and removing the germicide or sterilant. The apparatus does not have a filtering system connected to the chamber for providing a sterile water for rinsing medical device.
The apparatus can further comprise a vacuum pump connected to the chamber, preferably one capable of evacuating the chamber to a pressure below the vapor pressure of the liquid disinfectant or sterilant.
The chamber can be provided with an interface which separates the chamber into at least a first compartment and a second compartment. The interface preferably has at least one opening therethrough whereby the device can extend between through the opening into both the first and second compartments.
A method, according to the present invention, of disinfecting or sterilizing a device, comprises the steps of placing the device into a chamber, introducing a sterilant or disinfectant in liquid form into the chamber and contacting the device therewith for a sufficient period to disinfect the device, removing the sterilant or disinfectant from the chamber, and leaving the device essentially free of the sterilant or disinfectant without rinsing the instrument with a sterile solvent or solution.
Preferably, the step of removing the sterilant or disinfectant comprises vaporizing the sterilant or disinfectant into a vapor an drawing the vapor out of the chamber, preferably by lowering the pressure in the chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a schematic diagram of a container used in a cleaning/sterilizing process of the present invention.
FIG. 1 b is a schematic diagram of a stirrer with fluid inlets used in the container of FIG. 1 .
FIG. 1 c is a schematic diagram of a gas-permeable but microorganism-impermeable barrier installed in a vacuum port of the container of FIG. 1 .
FIG. 1 d is a schematic diagram of a container placed in a vacuum chamber used in a cleaning/sterilizing process of the present invention.
FIG. 1 e is a schematic diagram of a container with fluid jet tubes.
FIG. 2 is a schematic diagram of a container with an adapter used in the cleaning/sterilizing process of the present invention.
FIG. 3 a is a schematic diagram of a container with an interface used in the cleaning/sterilizing process of the present invention.
FIG. 3 b is a schematic diagram of a shutter used in the interface of the container of FIG. 3 a.
FIG. 3 c is a schematic diagram of a iris valve used in the interface of the container of FIG. 3 a.
FIGS. 3 d, 3 e, and 3 f are schematic diagrams of two plates forming an opening in the interface of the container of FIG. 3 a.
FIG. 3 g is schematic diagram of an interface of the container of FIG. 3 a.
FIG. 4 is a schematic diagram of a container placed in a vacuum chamber used in the process of the present invention.
FIG. 5 a is a schematic diagram of a container having two holders in an interface.
FIGS. 5 b and 5 c are schematic diagrams of two holders of the container shown in FIG. 5 a holding a lumen device.
FIG. 5 d is a schematic diagram of an interface of a container with multiple openings.
FIG. 6 is a schematic diagram of a container separated into three enclosures by two interfaces according to the present invention.
FIG. 7 a is a schematic diagram of a container having an interface and a tray across the interface according to the present invention.
FIGS. 7 b and 7 c are cross-sectional views of the container of FIG. 7 a at the location of the interface.
FIG. 8 a is a top view of the container of FIG. 7 a.
FIG. 8 b is a top view of a portion of the interface of FIG. 7 a.
FIG. 8 c is a top view of the tray of FIG. 7 a.
FIG. 8 d is a top view of the container of FIG. 7 a without the tray and the interface.
FIG. 9 is a schematic diagram showing a recycle system for processing liquid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The cleaning/sterilizing or cleaning/disinfecting process of the present invention can be carried out with various apparatus and incorporated with various sterilization methods, which are described below.
Method to Deliver a Predetermined Amount of Liquid Sterilant
This method can be incorporated into the cleaning/sterilizing or cleaning/disinfecting process of the present invention. In order to maximize the efficiency of a vapor sterilization process, it is important and desirable to drain excess sterilant solution and only keep a desired amount of the sterilant solution to vaporize after treating a device to be sterilized with the sterilant solution.
According to the present invention, a sterilization container or enclosure may have a surface with wells thereon which define a known volume. The well is positioned so that when a liquid sterilant is introduced onto the surface, a known volume of the liquid sterilant fills the well and when the liquid sterilant is drained from the surface, the known volume of liquid sterilant remains in the well so that a subsequent vapor sterilization process can be performed on the device with the known volume of liquid sterilant positioned within the surface. The surface preferably has at least one perforation for draining the liquid sterilant from the surface. The well formed in the surface can be curved, flat or angled. Thus, the well can be an inwardly extending hemispherical projection. The well can also be formed in the surface as an inwardly extending rectangular projection having rounded ends. The well formed in the surface can also be a rectangular box having side walls, defining an opening. Where perforations are provided, they can be disposed adjacent the well, and can be roughly spherical in shape. The upwardly extending projection can include a perforation thereon, which can be on top of the projection or on a side of the projection. The surface can be a sloped surface, a convex or concave surface or a V-shaped surface. The surface can be made of a variety of materials including stainless steels, aluminum, aluminum alloys, liquid crystal polymers, polyesters, polyolefins polymers or fluorinated polyolefins. If the surface is comprised of a composite material, the composite material can include a filler of high thermal conductivity. Examples of composite materials include a metal-filled polymer, a ceramic-filled polymer and a glass-filled polymer. Those materials are also suitable for the side walls and doors of the sterilization container.
A tray with wells with configurations similar to that described above can be provided with a container or enclosure. The tray can be secured to the container or removably placed in the container.
Method Based on Diffusion Restricted Environments
A method of vapor sterilization or disinfection under diffusion-restricted environments can also be used in corporation with the cleaning/sterilizing or cleaning/disinfecting process of the present invention. In this method, the devices (lumen or non-lumen) to be sterilized are pretreated with a sterilant solution, and then exposed to pressures less than the vapor pressure of sterilant. Both the exterior and interior surface areas of a lumen or non-lumen device can be effectively sterilized by taking advantage of the diffusion-restricted environments within lumens or within a container or enclosure.
As used herein, a “diffusion-restricted” area refers to any one or more of the following properties: (1) the ability of the area of an article placed within the sterilization system of the present invention to retain 0.17 mg/L or more hydrogen peroxide after one hour at 40° C. and 10 torr; (2) having the same or more diffusion restriction than provided by a single entry/exit port of 9 mm or less in internal diameter and 1 cm or greater in length; (3) having the same or more diffusion restriction than provided by a lumen 27 cm in length and having an internal diameter of 3 mm; (4) having the same or more diffusion restriction than provided by a lumen having a ratio of length to internal diameter greater than 50; (5) the ability of an article placed within the sterilization system of the present invention to retain 17% or more of the starting 1 mg/L hydrogen peroxide solution initially placed therein after one hour at 40° C. and 10 torr; or (6) being sufficiently diffusion-restricted to completely sterilize a stainless steel blade within a 2.2 cm by 60 cm glass tube having a rubber stopper with a 1 mm by 50 cm stainless steel exit tube therein at a vacuum of 10 torr for one hour at 40° C. in accordance with the present invention. It is acknowledged that characteristics (1) and (5) will vary depending on the initial concentration of hydrogen peroxide placed into the article; however, this can be readily determined by one having ordinary skill in the art.
This method includes the steps of contacting the exterior and interior of a device with a sterilant solution, and then exposing the device to a negative pressure or vacuum for a period of time sufficient to effect complete sterilization. For example, when 1 mg/L of hydrogen peroxide is used as sterilant, if the exposing step is conducted for 1 hour at 40° C. and 10 torr, the diffusion restricted area preferably retains 0.17 mg/L or more hydrogen peroxide, or retains 17% or more of the hydrogen peroxide placed therein after the exposing step. In certain preferred embodiments, the diffusion-restricted area has the same or more diffusion restriction than provided by a lumen 27 cm in length and an internal diameter of 3 mm, or has the same or more diffusion restriction than provided by a lumen having a ratio of length to internal diameter greater than 50. The contacting step can be performed by either a direct or an indirect contact procedure. Direct contacting includes methods such as injection, static soak, flow-through, condensation of a vapor, or aerosol spray, or mist spray. Any other methods involving physically contacting the devices to be sterilized with a sterilant would be considered direct contacting. Indirect contacting includes those methods in which sterilant is introduced into the chamber or container, but not directly on or on the devices to be sterilized. The exposing step is preferably performed for 60 minutes or less, and is preferably performed at a pressure less than the vapor pressure of the sterilant. Thus, the preferred pressure range under conditions of the present invention is between 0 and 100 torr. The exposing step can include the step of heating the device, such as by heating the container in which the exposing step occurs. The container can be heated to about 40° C. to about 55° C. Alternatively, the sterilant solution can be heated, such as to a temperature of about 40° C. to about 55° C. Optionally, the step of exposing the device to a plasma can be conducted during the step of exposing the device to negative pressure or vacuum. In one embodiment employing exposure to plasma, the method is performed within a first chamber and the plasma is generated in a second separate chamber. This embodiment further comprises the step of flowing the plasma into the first chamber. Advantageously, the contacting and/or exposing steps of the method can be repeated one or more times.
Method Based on Controlled Pump-Down Rate
The cleaning/sterilizing process of the present invention can also be carried out in cooperation with a controlled pump down method without relying on a diffusion-restricted environment.
Effective sterilization results similar to those created in diffusion-restricted environments can be created through controlling the evacuation rate of a chamber or container in which devices to be sterilized are placed. Thus, in one embodiment of the present invention, this controlled pump-down rate method comprises the steps of contacting the device with a liquid sterilant at a first pressure; draining excess liquid sterilant to retain a predetermined amount of the sterilant, and decreasing the pressure of the chamber to a second pressure below the vapor pressure of the liquid sterilant in which at least a portion of the decrease in pressure below about the vapor pressure of the liquid sterilant occurs at a pump down rate of less than 0.8 liters per second, calculated based on the time required to evacuate the chamber from atmospheric pressure to 20 torr when the chamber is empty and dry, i.e. when the chamber has neither devices to be sterilized nor a visible quantity of liquid within it. According to one aspect of this preferred embodiment, at least the decrease in pressure below about two times the vapor pressure of the liquid sterilant occurs at a pump down rate of less than 0.8 liters per second. According to another embodiment, the decrease in pressure below about four times the vapor pressure of the liquid sterilant occurs at a pump down rate of less than 0.8 liters per second. Preferably, the pump down rate is 0.6 liters per second or less; more preferably, 0.4 liters per second or less; and most preferably, 0.2 liters per second or less. Advantageously, the first pressure is atmospheric pressure. Preferably, the liquid sterilant is hydrogen peroxide. The hydrogen peroxide usually is a solution as used in the art, preferably it is a 3-60% solution. The device can be a lumen or non-lumen medical instrument.
The present invention can also incorporate a method for sterilizing a device comprising the steps of (a) contacting the device with liquid sterilant at a first pressure; (b) retaining a predetermined amount of the liquid sterilant in the container; (c) pumping down the container or chamber to a second pressure which is lower than the first pressure at a first rate; and (d) pumping down the container or chamber to a third pressure which is lower than the second pressure, wherein at least a portion of the pumping down to the third pressure is at a second rate which is slower than the first rate. The pump down rate either above and/or below the second pressure can be constant or variable. In certain embodiments, the pump down rate either above and/or below the second pressure is reduced in stepwise fashion. Preferably, the second pressure is greater than or equal to about the vapor pressure of the liquid sterilant; more preferably, the second pressure is greater than or equal to about two times the vapor pressure of the liquid sterilant; most preferably, the second pressure is greater than or equal to about four times the vapor pressure of the liquid sterilant. Advantageously, the pump down rate in step (d) is 0.8 liters/sec or less; more advantageously 0.6 liters/sec or less; even more advantageously 0.4 liters/sec or less; and most advantageously 0.2 liters/sec or less, calculated based on the time required to evacuate the chamber from atmospheric pressure to 20 torr under empty and dry conditions. Preferably, the liquid sterilant is hydrogen peroxide. In another embodiment, the device is a medical instrument having a lumen. Preferably, the pumping down of step (c) reduces the pressure to less than about three times, more preferably to less than about two times, the vapor pressure of the liquid sterilant.
Another suitable method includes contacting the device with liquid sterilant, retaining a predetermined amount of the liquid sterilant in the container, and reducing the pressure of the chamber while regulating the pump down rate so as to control the evaporation rate of sterilant in said chamber. In any of the methods described above, the contacting step may comprise application of liquid or condensed vapor. These methods described above may additionally comprise further evacuating the chamber to remove residual sterilant. Further, these methods described above may additionally comprise exposing the device to plasma to remove residual sterilant or enhance sterilization efficacy. The contacting step in these methods can be either by direct or indirect contacting. As stated herein, indirect contacting involves introducing sterilant into the chamber without directly contacting the device to be sterilized.
Two Step Pump-Down Method
A two step pump down sterilization method can also be used in cooperation with the cleaning/sterilizing process of the present invention. This method comprises the steps of contacting a device with liquid sterilant; draining excess liquid sterilant to retain a predetermined amount of the sterilant; bringing the pressure of the chamber to a first pressure range at which the liquid sterilant is vaporized from non-diffusion restricted area of the device to sterilize the non-diffusion restricted area; bringing the pressure of the chamber to a second pressure range at which the liquid sterilant is vaporized from diffusion restricted area of the device to sterilize the diffusion restricted area, wherein the minimum pressure in the second pressure range is lower than the maximum pressure in the first pressure range.
Preferably, the first pressure range is from 20 to 760 torr; more preferably, the first pressure range is 20 to 80 torr; most preferably, the first pressure range is 40-50 torr. Advantageously, the second pressure range is 1-30 torr; more advantageously, the second pressure range is 5-10 torr. In one preferred embodiment, the device includes a diffusion-restricted environment. Preferably, the device is a medical instrument with a lumen. Advantageously, the sterilant is hydrogen peroxide. According to another aspect of this preferred embodiment, the chamber is at a set temperature and wherein the first pressure is preferably lower than the vapor pressure of the sterilant at the set temperature. Preferably, the pressure of the chamber is maintained constant at the first pressure for a time period sufficient to sterilize the non-diffusion restricted area. Advantageously, the pressure of the chamber is maintained constant at the second pressure for a time period sufficient to sterilize the diffusion restricted area. The pressure of the chamber may be permitted to increase after reaching the first or second pressure range as a result of vaporization of the sterilant within said chamber. Alternatively, the pressure of the chamber is permitted to decrease after reaching the first or second pressure through pumping of said chamber at a rate slower than used to decrease the pressure between said first and second pressure ranges. Preferably, the contacting step is with liquid, condensed vapor, or mist. The method can also include the steps of bringing the pressure to a third pressure lower than the second pressure to remove residual sterilant and/or exposing the device to plasma to remove residual sterilant or enhance sterilization efficacy.
Method Involving Direct Flow Through a Lumen of the Device to be Sterilized
A method of directly flowing fluid through a lumen of a medical device to be treated can be incorporated with the cleaning/sterilizing or cleaning/disinfecting process of the present invention. An apparatus can be used to efficiently clean and sterilize devices with long narrow lumens by flowing a fluid such as a cleaning solution or a sterilant, either in liquid phase or in vapor phase, or a plasma gas directly through the lumens of lumen devices to be sterilized.
The flow of a germicide (solution or vapor), or any cleaning solution through a lumen of a medical device is driven by a pressure drop between two open ends of the lumen. The pressure drop can be generated by applying either a vacuum or a high pressure at one end. By generating a forced flow through a pressure differential other than relying on diffusion, the sterilization rate is significantly increased and less time is needed for a sterilization cycle.
It is clear that the two ends of the lumen need to be exposed to a pressure differential. This is achieved in the present invention by placing a sealable interface between two chambers, two enclosures, or a container and an enclosure to separate them from each other. Preferably, an opening is provided in the interface and the lumen device to be sterilized is placed through the opening so that the lumen serves as a flow path between the two chambers or between the container and the enclosure.
The opening can be constructed in several ways. One way to achieve this is with a camera shutter approach employing an iris diaphragm, such as a precision iris diaphragm from Edmund Scientific. An optional spring can be used to secure the closure of the shutter. Also commercially available is Syntron Iris Flow Control Valve manufactured by FMC Corporation. This Iris Valve has a sleeve made of Teflon or other synthetic material defining an aperture. By rotating two ends of the sleeve relative to each other, the aperture can be reduced or increased. Iris diaphragm valves from Kemutec Inc. are also commercially available which can be automatically controlled. Another example is the AirGripper and AirPicker manufactured by Firesone Industrial Products Company. Another way to construct an openable and closeable opening is to employ two plates. Two edges of the two plates form a gap which can be adjusted by moving the two plates relative to each other. One or more lumen devices are placed through the gap formed between the two plates and the two plates are moved together to form a seal around the lumen devices. The edges of the two plates forming the gap can be equipped with compressible material or expandable material. When expandable material is used, a fluid source can be provided to expand the expandable material. Optionally, a porous material like a sponge or air permeable material may be utilized on the edges. In this case some sterilant can diffuse through the porous material to the outer surface of the lumen device occluded by the closed opening. However, most the sterilant flows through the lumen device. Another usable interface is a hole or a slot, the hole or slot is equipped with gas or liquid inflatable material so that by inflating the inflatable material on the hole or the slot the opening is reduced and the lumen device is held and sealed. Still another option is to place a compressible material on top of an expandable or inflatable material so as to facilitate the sealing around the lumen device.
The closing and opening movement of the opening can be controlled mechanically or electronically with any conventional mechanism. The degree of opening is adjustable. Thus, it can be sealed to a different degree between the opening and the lumen device depending on the desired purpose. For example, the opening can form a gas-tight seal, a tight-fitting seal, or a loose-fitting seal around the lumen device. As used herein, a gas-tight seal refers to a seal that substantially stops liquid and gas flow through the contact area between the opening and the lumen device surface. When a gas-tight seal is employed, preferably the device to be sterilized is first pre-cleaned so that the occluded area by the seal is cleaned before the gas-tight seal is formed. A loose-fitting seal allows both liquid and gas to flow through the gap between the opening and the lumen device surface, and in the meantime is able to maintain a pressure drop across the interface enough to generate a flow through the lumen. A tight-fitting seal allows gas and liquid to penetrate to the contact area between the opening and the lumen device surface by diffusion. For example, a tight-fitting seal can be formed with porous material or textures provided on the contact surface of the opening. Thus, for gas-tight seal the device is held tightly by the closed opening. In the tight-fitting seal, the closed opening also holds the device in position. In the case of a loose-fitting seal, the device can move relative to the opening, but is not flashed away.
The interface can be made openable, closeable, and removable, and may have more than one opening. In order to promote sterilization efficiency, all the sterilization apparatus of the present invention can be further equipped with a heater and/or a plasma.
Specially Designed Containers
As used herein, the terms “container” and “enclosure” are exchangeable. The present invention provides a container specially designed to eliminate or minimize occlusion area which usually corresponds to the contact area between a lumen device surface and a closed opening of an interface holding the device. The occlusion area is hard to reach by either liquid or vapor because of the close contact between two surfaces. Thus, the cleaning and sterilizing of an occlusion area is adversely affected by such contact. Several approaches have been taken in the present invention to deal with this occlusion problem.
One approach is to reduce the contact area by using porous material, textures, sharp projections, or sharp edges on the contact surface of the opening of the interface, or an adaptor or a connector. In this way, cleaning and sterilizing fluid can either flow or diffuse to most part of the contact surface of the device which is held by the closed opening fairly tightly and, in the meantime, the contact area between the opening and the device surface will impose a resistance to fluid flow high enough to allow a pressure difference to exist between two sides of the interface. Thus, a flow through the lumen of the device can be generated and maintained if desired. Another advantage of this approach is that the contract area generated through the above means can be controlled to provide a diffusion restricted environment at the contact area, which will increase the efficiency of the sterilization process.
Another approach is to use multiple holders in the opening. For example, two holders can be secured to the opening along its passage. Preferably, each of the holders is independently controllable and sealable. During a cleaning or sterilizing process, the two holders are alternately opened and closed, i.e. one is open while the other is close. In this way, a good seal between the two sides of the interface can be maintained and the device can be held tightly during a sterilization process. Meanwhile, the contact areas on the device surface caused by the two holders are exposed to cleaning or sterilizing fluid alternately.
Still another approach is the combination of the above two approaches. In this approach, the contact surface of the interface, or the opening, or the holder has multiple contact points. The contact points can be projections, teeth, blades, sharp edges, or any other suitable form and shape. These contact points can be controlled separately so that a portion of the contact points is made in contact with the device to be sterilized while the others are not. By alternately changing the position of the contact points, all the occlusion areas will be exposed to the sterilant. An example of such a multiple contact point structure is a shutter with multiple blades. Those blades can be separately controlled for opening and closing.
The present invention also provides a container with a specially designed tray. It is often desirable to place the device to be sterilized on a tray so that after the device is cleaned and sterilized, it can be transported on the tray without being touched. This reduces the chance of contamination through touching the device. In the apparatus of the present invention, a tray is placed across an openable and closeable interface between a container and an enclosure or between two compartments or enclosures, a lumen device is placed on the tray also across the interface. When the interface is in a closed condition, a seal is formed between the opening of the interface and the tray and the lumen device.
Various apparatus of the present invention which can be used to carry out the cleaning/sterilizing or cleaning/disinfecting process of the present invention is described in more detail by reference to the drawings. In the following figures like numbers refer to like parts throughout.
FIG. 1 a shows a container 2 used in a cleaning/sterilizing process of the present invention. Container 2 has a sloped bottom wall 4 leading to a fluid source 7 . A fluid port 6 is provided at the lowest point of sloped bottom wall 4 . Apparently, sloped bottom wall 4 can be configured differently and the lowest point can be located in any location within the sloped bottom wall 4 . For example, instead located in the position as shown in FIG. 1 a, the lowest point, thus the fluid port 6 , can be located at one end or a corner of the sloped bottom wall 4 . A valve 8 is provided at fluid port 6 to control fluid flow in and out container 2 . Below sloped bottom wall 4 is a flat lower bottom 14 . The lower surface of the sloped bottom wall 4 is equipped with a number of transducer 16 for providing ultrasonic cleaning. A number of wells 18 are provided on a plate 17 located above the upper surface of the sloped bottom wall 4 and below rotating arm 22 . Plate 17 can be of any appropriate shape and made rotatable, so that unwanted liquid retained in wells 18 can be removed by rotating plate 17 . Well 18 can have different shapes and is capable of retaining a predetermined amount of sterilant as described earlier. Plate 17 can be removably placed on the upper surface of the sloped bottom wall 4 or secured to the upper surface in a horizontal orientation. One or more stirrer 20 is installed either on sloped bottom wall 4 or on an upper wall 24 or on both. Rotating arm 22 of the stirrer 20 can be made hollow or contains channels connecting to an outside fluid source through the body of the stirrer 20 . As shown in FIG. 1 b, stirrer 20 can be connected to a water source 21 a, an air source 21 b, and a drain 21 c, each of them is controlled by a valve. Water jet or air jet 26 can be provided through the channels of rotating arm 22 . Container 2 can also be made of jacket walls with holes thereon so that the water or air jet can be provided through those holes opened on the jacket walls. Container 2 also has a lower grid 28 a and an upper grid 28 b. Preferably, grid 28 a and 28 b has a flat shape and horizontally placed inside container 2 at an upper and a lower position, respectively. A space defined by lower grid 28 a, upper grid 28 b and side walls of container 2 is used to accommodate a device to be treated. A tray 30 can be placed in the space and the device is placed in the tray 30 for cleaning and sterilizing. Stirrer 20 is located either in the space defined by upper wall 24 , upper grid 28 b and side walls of container 2 , or in the space defined by sloped bottom wall 4 , lower grid 28 a and side walls of container 2 , or in both. Container 2 further contains a vacuum port 32 located at the upper portion of container 2 . Preferably, vacuum port 32 is located on the upper wall 24 of container 2 to avoid liquid in container 2 from entering vacuum port 32 . A gas-permeable but microorganism-impermeable barrier 34 is secured to the vacuum port 32 . Any conventional method can be used to seal barrier 34 into vacuum port 32 such as shown in FIG. 1 c. In the connection shown in FIG. 1 c, barrier 34 is placed in a barrier holder 34 a. The barrier holder 34 a is placed into a seat 34 b formed between two end of two tubes. An O-ring 34 c is provided around holder 34 a. Thus, by clamping the two ends of the two tubes toward each other barrier 34 is secured and sealed. A valve 36 is provided at vacuum port 32 . A vacuum pump 38 is connected to vacuum port 32 through valve 36 . A detachable connector can be provided between valve 36 and vacuum pump 38 .
Container 2 of FIG. 1 a can be placed into a vacuum chamber with slight modification. As shown in FIG. 1 d, the same container 2 is used except that barrier 34 provided on upper wall 24 is not connected directly to the vacuum port 32 which is provided on the wall of a vacuum chamber 66 .
FIG. 1 e shows another way of providing a fluid jet in container 2 . Instead of stirrers, several tubes 22 a with small holes thereon are secured vertically in container 2 to provide a fluid jet such as a water jet or an air jet. Tube 22 a can be positioned to provide an uniform spray, the orientation and shape of tube 22 a can be determined according specific purposes. The rest parts can be the same as the container of FIG. 1 a.
When using the above described container in the cleaning/sterilizing process of the present invention, one first places a device into the container 2 . The device can be either placed on the lower grid 28 a or placed in tray 30 . Two grids 28 a and 28 b set the boundaries for the devices in the container and keep the device from being damaged by stirrer 20 . The upper grid 28 b is the fluid fill line to ensure all the devices are immersed in the fluid. Usually the device is first pre-cleaned in container 2 by a water jet to remove majority of soils, large particles, and other contaminates. During the pre-cleaning, the drain is usually kept open to remove the dirty water containing those particles and contaminates. Then the device is cleaned. In this step a cleaning solution is filled into container 2 through a liquid pump. The cleaning solution can be any conventional cleaning solution with enzyme and detergent solution preferred. During the cleaning step, stirrers, water jet, ultrasonics, or other suitable mechanism can be used to facilitate the cleaning process. When the cleaning is complete, the cleaning solution is drained through fluid port 6 . A rinse solution is then introduced into container 2 through fluid port 6 . The rinse solution can be water, alcohols, or other rinse liquid. The rinsing can be facilitated by stirrers, water jet, air bubbles, or other suitable mechanism. These steps can be repeated if desirable. After the rinsing step, air can be introduced through stirrer 20 to blow water off the device. Then a liquid sterilant is introduced into container 2 from the same fluid port, and the device is treated with the liquid sterilant for a desired time. Preferably, the liquid sterilant is a hydrogen peroxide solution or a peracetic acid solution. The main purpose of this step is to treat the device with the liquid sterilant and to provide right amount of the liquid sterilant. The sterilization is achieved mainly in next step. If necessary, excess of the liquid sterilant can be drained from container 2 , and a predetermined amount of the liquid sterilant will be retained by the wells 18 . This amount of liquid sterilant is determined based on the size of the load, the container, and the vacuum chamber. At this point, vacuum pump 38 is turned on and vacuum is applied to container 2 through vacuum port 32 . In this step, the diffusion restricted environment method, the controlled pump down rate method, the two step pump down method discussed previously can be employed to achieve good sterilization results. When the sterilization is finished, container 2 is detached from the vacuum system, the device can be kept in container 2 and stored for future use. The sterility of the sterilized device is maintained in container 2 because container 2 is sealed except for the gas-permeable but microorganism-impermeable barrier 34 . In one embodiment, valve 36 is closed when the pressure in container 2 is lower than atmospheric pressure and container 2 including the sterilized device is stored for use. This procedure provides a further means to check if the sterility of the device is well maintained in the container. If the container 2 is still under a pressure below the atmosphere before next use of the device, that means no air leaking into container 2 and, thus, no microorganism can enter container 2 during the storage. Any one of the above steps can be repeated if desirable. The sterilizing step can also be replaced with a disinfecting step by using a proper germicide.
FIG. 2 shows a container having adapters for connecting lumen devices. Similar to the container of FIG. 1 a, container 2 shown in FIG. 2 has a sloped bottom wall 4 with a first fluid port 6 at the lowest point of the sloped bottom wall 4 . Several stirrers are installed on the sloped bottom wall 4 . A flat sheet metal grid 28 a is horizontally located at the lower portion of container 2 . Grid 28 a, sloped bottom wall 4 , and side walls of container 2 define a space accommodating stirrer 20 and wells 18 on plate 17 . An adapter 40 is connected to a second fluid port 42 at one end and the other end for receiving a lumen device 46 . A gas-tight seal, tight-fitting, or loose-fitting between adapter 40 and lumen device 46 can be formed. Adapter 40 can be any suitable conventional adapters used in the art. Preferably, the second fluid port 42 is located above grid 28 a. Second fluid port 42 is also connected to a source 44 for generating a pressure difference between the two ends of a lumen device 46 which is connected with the second fluid port 42 through adapter 40 . Source 44 can be a liquid pump for generating negative pressure, or a positive pressure. Lumen device 46 is placed on top of the grid 28 a. Like the container shown in FIG. 1 a, container 2 of FIG. 2 also has a vacuum port 32 with a gas-permeable but microorganism-impermeable barrier 34 and a valve 36 . The barrier covers the vacuum port 32 and blocks passage for microorganism, valve 36 controls the opening and closing of the vacuum port 32 . As shown, fluid port 6 and stirrers 20 are also connected with a tube 9 for draining fluid from container 2 or supplying fluid jet to stirrer 20 . One end of tube 9 leads to a waste fluid collector, the other end is connected to pump 44 .
FIG. 3 a shows a container 2 separated into a first enclosure 50 a and a second enclosure 50 b by an interface 52 . As shown both enclosure 50 a and 50 b have a sloped bottom wall 4 with stirrer 20 secured thereon, a flat sheet grid 28 a horizontally positioned at lower portion of enclosure 50 a and 50 b, and a fluid port 6 , respectively. A pump 54 is provided between the two fluid ports 6 . A vacuum port 32 is provided at the upper portion of enclosure 50 a and 50 b. A gas-permeable but microorganism-impermeable barrier 34 is connected to the vacuum port 32 to stop microorganism from entering enclosure 50 a and 50 b through vacuum port 32 . Vacuum port 32 is also equipped with a valve 36 and a source 44 for generating pressure difference and providing vacuum. Preferably, source 44 is a vacuum pump for providing negative pressure or compressed air for providing positive pressure. Interface 52 has a controllable opening 56 (also referred as holder). Lumen device 46 is placed across opening 56 partly in enclosure 50 a and partly in enclosure 50 b. Opening 56 can be configured differently. For example, opening 56 can be made of a shutter 58 such as an iris diaphragm as shown in FIG. 3 b, and the opening and closing of opening 56 can be controlled manually or automatically. In one embodiment, the blades of shutter 58 (eight blades are shown in FIG. 3 b ), can be divided into two groups. For example, each group contains four blades not next to each other. These two groups of blades are controlled separately by a controller so that while one group is in the close position holding the device to be sterilized the other group is in open position allowing the sterilant to sterilize the area occluded by the blades when the blades are in closed position. Another example of shutter 58 is the Syntron Iris Flow Control Valve (by FMC Corporation) or the Iris diaphragm valves (Kemutec Inc.) as shown in FIG. 3 c. Briefly, Iris valve 58 a has a cylindrical sleeve 90 with two retaining rings 92 located at two ends of the cylindrical sleeve 90 . Sleeve 90 is made of Teflon or other suitable plastic or rubber material. When in use, a lumen device is inserted through an aperture 94 of cylindrical sleeve 90 . A first retaining ring 92 is secured and sealed to opening 56 , a second retaining ring 92 is free to rotate and coupled to interface 52 through a conventional mechanical mechanism (not shown) so that the turning of the second retaining ring 92 can be controlled mechanically or electronically from outside container 2 . By rotating the retaining rings 92 relative to each other, the diameter of aperture 94 of the cylindrical sleeve 90 can be increased or reduced, or totally shut off. If desirable, more than one shutter can be provided in the interface 52 .
Opening 56 also can be a slot or a gap defined by two plates 59 as shown in FIGS. 3 d and 3 e. The contact edges or surfaces of plate 59 , which form the slot and hold the lumen device 46 , are equipped with a layer of expandable material 60 such as silicon, or a layer of compressible material 62 . The closing, and thus seal around lumen device 46 , of the slot can be done either by moving plate 59 or expanding expandable material 60 . With a two-plate opening 56 , more than one lumen device can be placed across the opening 56 . When expandable or inflatable material is used on plate 59 , an expansion fluid source can be provided to plate 59 to expand the expandable material 60 . In one embodiment, a layer of compressible material 62 is provided on top of the layer of expandable material 60 as shown in FIG. 3 f. In another embodiment, the opening 56 is formed by an upper plate 59 a and a lower plate 59 b as shown in FIG. 3 g. The lower plate 59 b has a rectangular shape with a bottom edge and two side edges being secured and sealed to the bottom wall and two side walls of container 2 , respectively. The upper plate 59 a also has a rectangular shape and its upper portion is movably inserted into a housing 53 a. Housing 53 a forms the upper portion of interface 52 . A portion of housing 53 a extends along two side walls of container 2 to the upper edge (or contact surface) of lower plate 59 b, forming two rails 53 b for receiving the two side edges of upper plate 59 a and guiding the movement of the upper plate 59 a. There provided a seal between the upper plate 59 a and the housing 53 a and rail 53 b. For example, an O-ring can be used in housing 53 a and rail 53 b to seal the upper plate 59 a. The upper edge of the lower plate 59 b and the lower edge of the upper plate 59 a are provided with a layer of compressible or expandable material. The movement of the upper plate 59 a can be controlled by any suitable conventional method, mechanically or electrically, form the outside of container 2 . Many different configurations and structures can be adopted for the opening 56 . For example, the contact surface of opening 56 can be made of an uneven surface so that, when opening 56 is closed around a lumen device, the uneven surface will provide passage to allow both liquid and gas to pass therethrough while holding the lumen device. Thus, the occlusion area on the lumen device surface can be significantly reduced. The uneven surface may have textures, projections, sharp edges, or sharp points thereon.
In another embodiment, opening 56 is an aperture equipped with a layer of porous material or with a layer of expandable material and a layer of porous material on top of the expandable material. Opening 56 also can be made of an aperture of suitable shape, such as cylindrical, lined with porous material. A shutter is secured to the aperture providing a steady holding of the lumen device 46 with minimal contact area or occlusion area.
FIG. 4 shows a container 2 with an enclose 50 separated by an interface 52 . In this embodiment, the container 2 with the enclosure 50 is placed inside and coupled to vacuum chamber 66 . Vacuum chamber 66 has a first vacuum port 68 which is in gas communication with container 2 through a gas-permeable but microorganism-impermeable membrane 34 installed on the upper wall of container 2 , and which is preferably located at the upper portion of a side wall of vacuum chamber 66 . A valve 35 is provided above membrane 34 to control the opening and closing of gas communication of container 2 with outside through membrane 34 . Vacuum chamber 66 also has a second vacuum port 70 connecting to a vacuum port 32 of the enclosure 50 through a valve 36 . Preferably, the second vacuum port 70 also located at the upper portion of the side wall of the vacuum chamber and near the first vacuum port 68 . Valve 36 is preferably located outside the enclosure 50 and inside the vacuum chamber 66 . A detachable connector (not shown) is preferably provided between valve 36 and second vacuum port 70 for attaching valve 36 to and detaching valve 36 from the second vacuum port 70 . The first and second vacuum ports 68 and 70 are connected to each other outside the vacuum chamber 66 . A valve 72 is provided at first vacuum port 68 to control flow through the first vacuum port 68 . A valve 74 can also be provided at the common inlet of the first and second vacuum ports 68 and 70 . A source 44 for generating pressure difference between the two ends of the lumen device 46 is provided at the common inlet of first and second vacuum ports 68 and 70 . Preferably, source 44 is a vacuum pump for generating a negative pressure or compressed air for generating a positive pressure. Vacuum chamber 66 also has a first fluid port 76 connecting to a fluid port 6 a of the container 2 through a valve 8 a, and a second fluid port 78 connecting to a fluid port 6 b of the enclosure 50 through a valve 8 b. The first and second fluid ports 76 and 78 are located at the lower portion of a side wall of the vacuum chamber 66 and close to each other. The fluid port 6 a is located at the lowest point of a sloped bottom wall 4 a of the container 2 . In this embodiment, the fluid port 6 a is located at one lower corner of the container 2 . The fluid port 6 b is located at the lowest point of a sloped bottom wall 4 b of the enclosure 50 . In this embodiment, the fluid port 6 b is located at one lower corner of the enclosure 50 . A detachable connector can be provided for connecting valve 8 a and 8 b to first and second fluid port 76 and 78 , respectively. Outside the vacuum chamber 66 , first and second fluid ports 76 and 78 are connected to each other forming a common fluid inlet which is provided with a valve 80 . A liquid pump 54 is also provided between the first and second fluid ports 76 and 78 to circulate a fluid between the container 2 and the enclosure 50 . The container 2 has a lower grid 28 a and an upper grid 28 b. Preferably, the lower grid 28 a and the upper grid 28 b are a flat metal sheet and horizontally positioned at the lower and the upper portion of the container 2 , respectively. Stirrers 20 are located below the lower grid 28 a. Interface 52 has an opening (or holder) 56 for holding a lumen device 46 . The opening 56 can be configured in many different ways such as those described with FIGS. 3 b - 3 f. On the bottom wall of vacuum chamber 66 , a plurality of transducer 16 is provided to generate ultrasonics. Accordingly, the space between outer surface of the bottom of container 2 and the inner surface of the bottom wall of vacuum chamber 66 is filled with water or other suitable liquids providing a medium for the ultrasonics.
In using the apparatus with containers and enclosures separated by an interface in the cleaning/sterilizing or cleaning/disinfecting process of the present invention, a lumen device is placed into the container 2 and the enclosure 50 across the interface 52 . The opening 56 of the interface 52 is then closed manually or automatically. Thus, opening 56 forms a seal around the lumen device. The extent of the sealing can be controlled through different degree of tightening of the opening 56 around the lumen device 46 for different purposes. As defined previously, three types of seal can be made between the opening 56 and the lumen device 46 , gas-tight seal, loose-fitting seal and tight-fitting seal. If maximum pressure is intended a gas-tight seal should be used in this case the container 2 is substantially totally sealed from the enclosure 50 , neither gas nor liquid can flow through the space between the opening 56 and the lumen device 46 . Under many situations such a gas-tight seal is not necessary. In this case, a tight-fitting seal can be used so that a portion of fluid in the system can flow or diffuse through the space between the opening 56 and the lumen device 46 , but a large portion of the fluid flows through the lumen of the lumen device 46 , and the lumen device 46 is still held in position by the opening 56 during agitation. Loose-fitting will provide a opportunity to clean/sterilize the outer surface area of the lumen device 46 which is otherwise obscured by the opening 56 .
A cleaning solution is then introduced into the container 2 and the enclosure 50 through fluid port 6 a and 6 b, respectively. The liquid level in the container 2 and the enclosure 50 is preferably not higher than the position of the vacuum port 32 . A stirrer, a water jet or an air jet can be used to facilitate the cleaning of the outer surface of the lumen device 46 . The cleaning solution is also circulated between container 2 and enclosure 50 through the lumen of the lumen device 46 . There are at least two ways to make the circulation. One method is to apply vacuum to the enclosure 50 through second vacuum port 70 of vacuum chamber 66 and vacuum port 32 of the enclosure 50 while keeping vacuum chamber 66 and container 2 at atmospheric pressure or any pressure higher than that of the enclosure 50 . This can be done similarly when vacuum chamber 66 is not used. The cleaning fluid then flows from the container 2 into the enclosure 50 through the lumen device 46 . The liquid pump 54 circulates the cleaning fluid back to the container 2 . The opening 56 and the stirrer 20 can be controlled by the electronic signals from the system. Air bubbles generated from air pump 10 can be introduced at this stage to enhance the scrubbing action during cleaning. Thus, both the outer surface and the inner surface of the lumen device 46 can be cleaned at the same time. Vacuum can be applied to container 2 to generate a pressure in the container 2 lower than that of the enclosure 50 . Forced air also can be used to push liquid through the lumen. If desired, the interior and the exterior of the lumen device can be cleaned separately. The cleaning fluid can be removed from the container 2 and enclosure 50 through the fluid port 6 a and 6 b on the sloped bottom wall 4 a and 4 b. The cleaning fluid in the lumen device 46 can be removed either with vacuum or forced-air.
The rinsing with water and the treatment with liquid sterilant can be conducted similarly. When the treatment with a liquid sterilant is complete, the liquid sterilant is drained and a predetermined amount of the liquid sterilant can be retained in the wells. Then vacuum is applied to chamber 66 and container 2 either through vacuum port 68 or 70 , or both in a manner described earlier. At least in certain stage, the vacuum should be high enough (or the pressure low enough) to vaporize the remaining sterilant in container 2 to sterilize and dry the device simultaneously. A plasma can be used as an option to enhance the efficacy and/or to remove the sterilant residual. After the sterilization is completed, the chamber is vented and the container is ready to be retrieved from the chamber. If desired, valve 35 can be closed at any pressure below the atmospheric pressure and the sterilized device is kept in container 2 under a subatmospheric pressure. This may serve as an indication of a well maintained sterility, i.e. if the vacuum still exists when container is opened after a period of time of storage that indicates the sterility of the sterilized device is well kept. The pressure can be monitored and controlled by the pressure sensor on the vacuum chamber 66 or in container 2 .
FIG. 5 a shows a container very similar to that shown in FIG. 3 a except that two holders 100 are used in opening 56 of interface 52 . As shown in FIGS. 5 a and 5 b, the two holders 100 are secured to opening 56 along lumen device 46 or the passage of opening 56 . Each holder 100 is sealed to opening 56 in any suitable conventional manner and each holder 100 is independently controllable. Holder 100 can be a shutter as the shutter described with FIGS. 3 b and 3 c, or made of two plates as described with FIGS. 3 d - 3 g. FIG. 5 b shows two holders 100 of shutter type holding a lumen device 46 . During cleaning or sterilizing operation, a first holder 100 is first closed and a second holder 100 is opened, then the first holder is opened and the second holder 100 is closed. Thus, enclosures 50 a and 50 b are always separated or insulated from each other through the engagement of one holder 100 with the device 46 and, in the meantime, the two contact surface areas of the device 46 occluded by the two holders 100 are exposed alternately.
FIG. 5 c shows two holders 100 of plate type holding a lumen device 46 . Each of holders 100 can be constructed in the way as described previously with FIGS. 3 d - 3 g. Preferably, the gap (the opening for passing the lumen device) formed between the two plates of one holder 100 forms an angle with that of the other holder 100 of the two holder structure. Preferably, the angle is 90 degree as shown in FIG. 5 c. The two holders 100 are preferably positioned close enough so that when the expandable material 60 lined in the gap (opening) is expanded, the expandable material 60 will also expand outwardly away from the two plates and become in contact with the other holder 100 , thus help seal the gap of the other holder 100 . This configuration provides an advantage that no complete seal is needed for a single holder, yet a good seal such as a gas-tight seal can be achieved when two such holders are combined. It has been noted by the applicants that, when a cylindrical lumen device is placed across the gap between the two plates of holder 100 , areas on the outer surface of the lumen device, where the diameter of the cylindrical lumen device is parallel to the gap, are more difficult to seal because the expandable material 60 has to expand extra distance to cover those areas. By providing two closely positioned holders 100 with the two gaps forming an angle, the above mentioned areas in each of the two holders can be sealed by the other holder. Therefore, the requirement to the expandable material can be lowered without sacrificing the sealing characteristics. FIG. 5 d shows another embodiment of an interface of the present invention. In this embodiment, the interface 52 contains multiple openings 56 c. This interface 52 may have three parts. A first plate 59 c has a plurality of openings 56 c thereon. The cross section of the opening 56 c as viewed from a direction perpendicular to the surface of plate 59 c has an elongate shape with its longitudinal axis extending along a substantially vertical direction. Other orientation also can be adopted. Preferably, opening 56 c has a rectangular cross section. The upper side of the openings 56 c can be made open for easy access to a lumen device. The contact surface of opening 56 c is provided with a layer of expandable material 60 . A second plate 59 d is positioned beside the first plate 59 c in parallel. Plate 59 d can be secured and sealed to the bottom and side walls of container 2 with its upper edge or surface equipped with a layer of expandable material 60 . A third plate 59 e is located above and aligned with second plate 59 d. The third plate can be made a part of the lid for container 2 . The lower edge of plate 59 e and the upper edge of plate 59 d form a gap for passing a lumen device. The edges of the third plate is also provided with a layer of expandable or other sealing material 60 . Preferably, the second plate 59 d and the third plate 59 e lie in one vertical plane, and the first plate 59 c lies in another vertical plane parallel to that containing second plate 59 d and third plate 59 e. Preferably, the gap formed between plate 59 d and 59 e forms an angle with openings 56 c, more preferably the angle is a right angle. In one preferred embodiment, the gap between second plate 59 d and third plate 59 e has a horizontal orientation, and the openings 56 c have a vertical orientation. The distance between the first plate 59 c and the second and third plate 59 d and 59 e can be adjusted depending on intended purpose. Preferably, they are closely positioned relative to each other so that when the expandable material 60 on one plate is expanded, it will become in contact with the other plate to further facilitate seal around the lumen device passing both the gap between plate 59 d and 59 e and the opening 56 c of plate 59 c. Preferably, the dimension and the expandable material layer of opening 56 c is determined to allow the opening 56 c to be closed and sealed when the expandable material is expanded even no lumen device is placed through the opening.
FIG. 6 shows a container 2 has three enclosures 50 a, 50 b, and 50 c separated by two interfaces 52 a and 52 b, respectively. Enclosure 50 b is located in between and shares interfaces 52 a and 52 b with enclosure 50 a and 50 c. Other parts of the container 2 of FIG. 6 are similar to those of the container shown in FIG. 3 a, and they are indicated by same numerical references. Two openings 56 a and 56 b are located in interface 52 a and 52 b, respectively. Opening 56 a and 56 b can be of any form as discussed previously. In practice of the process of the present invention, a lumen device 46 is placed across both opening 56 a and opening 56 b with one end located in enclosure 50 a and the other end in enclosure 50 c. The advantage of the configuration is to help obtain a large pressure drop between the two ends of the device 46 . Under certain circumstances, the seal between the opening and the lumen device may be not gas-tight, thus it is difficult to keep a large pressure drop at the two sides of the interface with such a seal. By adding one intermediate enclosure 50 b, the pressure drop across each interface 52 a and 52 b can be kept at a relative low level, yet the total pressure between the two ends of the device 46 or, in other words, between enclosure 50 a and enclosure 50 c can be still large enough to generate desired flow rate through the lumen of the lumen device 46 . If desired, one interface 52 a or 52 b can be removed or opened, and in those cases the container 2 can be operated just like that of FIG. 3 a.
FIG. 7 a shows a container 2 separated into an enclosure 50 a and an enclosure 50 b by an interface 52 similar to the container of FIG. 3 a except that a tray 110 is placed across interface 52 and located in both enclosure 50 a and enclosure 50 b. The tray 110 shown in FIG. 7 a has a rectangular shape with four side walls perpendicular to a bottom wall defining a space for receiving a lumen device 46 . The side and bottom walls have open holes thereon. As shown in FIG. 7 b, interface 52 can be configured to have two parts. The first part forms a tray seat 112 extending along an interior periphery of container 2 . Tray seat 112 has a first edge secured and sealed to the interior periphery of container 2 and a second edge 114 shaped to receive tray 110 . Edge 114 has a bottom portion and two side portions defining an open rectangular cross section. On top of edge 114 is a sealing layer 116 made of expandable, compressible, or other suitable material. When tray 110 is placed into container 2 , an exterior periphery of tray 110 will seat on edge 114 and layer 116 . The second part of interface 52 can be a removable plate 118 having an edge 120 shaped to fit the shape of an interior periphery of tray 110 . On top of edge 120 is a sealing layer 122 made of expandable, compressible, or other suitable material. Plate 118 is inserted into tray 110 along an interior periphery of tray 110 . A guide rail can be provided with tray 110 to guide plate 118 moving along an predetermined interior periphery. Different shapes can be used for edge 114 of seat 112 and edge 120 of plate 118 , as long as the shape matches that of the exterior and interior periphery of tray 110 . For example, in one embodiment, the open rectangular formed by edge 114 and edge 120 shown in FIG. 7 b is modified by making the upper edge longer than the bottom edge of the open rectangular and tray 110 has a corresponding shape. This configuration makes it easier to the plate 118 down into tray 110 and seal it. Plate 118 can further include an opening 56 of any kind as discussed previously with FIGS. 3 b - 3 g. Opening 56 can be located in plate 118 or on edge 120 facing the bottom of tray 110 where lumen device is placed. In one embodiment, a layer of expandable, compressible, or other suitable sealing material is also provided with tray 110 along the interior periphery where plate 118 is inserted. FIG. 7 c shows another embodiment in which tray 110 has a partition 111 therein. Partition 111 can be made as part of the tray 110 . Upper edge 111 a of partition 111 has a layer of expandable, compressible, or other suitable sealing material. Partition 111 is aligned with plate 118 so that when plate 118 is inserted into tray 110 seal can achieved between upper edge 111 a of partition 111 and lower edge of plate 118 , and a lumen device can be placed through the gap or opening 56 formed between upper edge 111 a of partition 111 and lower edge of plate 118 . In one embodiment, in the contact area between tray 110 and interface 52 (or plate 112 and 118 ), a portion of side and bottom walls of tray 110 is removed so that in those portion the sealing layer 116 of tray seat 112 and the sealing layer 122 of plate 118 of the interface 52 are in direct contact. Plate 118 can be secured to a lid or cover 119 for container 2 and, a portion of the lower surface of the cover 119 is provided with a layer of expandable, compressible, or other suitable sealing material to seal the upper edge of the tray 110 and the container 2 as shown in FIG. 7 c.
When exposed to a pressure difference between enclosure 50 a and 50 b, tray 110 may be forced to move from high pressure side to low pressure side. In order to prevent this from happening, a stopper mechanism is provided. In one embodiment as shown in FIGS. 8 a - 8 d which are top views of container 2 and tray 110 , tray 110 has a rectangular bottom wall 130 with two side walls 132 along two longer edges of bottom wall 130 and two side walls 134 along two shorter edges of bottom wall 130 . There is an indentation on each side wall 132 extending along the entire height of side wall 132 and substantially perpendicular to bottom wall 130 . Container 2 also has a rectangular bottom wall 140 with two side walls 142 along the two longer edges of bottom wall 140 and two side walls 141 along two shorter edges of bottom wall 140 . There is a projection 144 on each side wall 142 extending along the entire height of side wall 142 and perpendicular to bottom wall 140 . The surface of projection 144 is covered with a layer of expandable, compressible, or other suitable sealing material 146 . The projection 144 has a shape matching that of the indentation 136 . When tray 110 is placed into container 2 , indentation 136 will engage with projection 146 so as to hold tray 110 in position. A tray seat 112 with a layer of sealing material on its upper surface is provided on bottom wall 140 of container 2 extending between two projections 146 . Tray 110 also has two edges 137 on each side wall 132 extending inwardly from indentation 136 . A removable plate 118 with a layer of sealing material on its contact edge is inserted into tray 110 through a rail defined by extruding edge 137 . In another embodiment, each side wall 141 is provided with a stopper, such as an extrusion, to confine the movement of tray 110 along a direction perpendicular to interface 52 .
FIG. 9 shows a recycling system which can be incorporated into any container systems used in the present invention. In this system, used liquid in a cleaning/sterilizing process is drained or pumped to a reservoir 150 through a filter 152 . A pump 154 can be provided between reservoir 150 and fluid port 6 to help drain the used liquid into reservoir 150 . The filtered liquid in reservoir 150 can be then cycled back to container 2 through a fluid port 6 a. If necessary, filter 152 can be cleaned by back flash. Reservoir 150 is also equipped with several inlets 156 for water, cleaning chemical, and sterilant, respectively, and a drain 158 .
The present invention has been described above. Many modifications and variation of the cleaning/sterilizing or cleaning/disinfecting process and the apparatus in such process may be made without departing substantially from the spirit and scope of the present invention. Accordingly, it should be clearly understood that the form of the invention described and illustrated herein is exemplary only, and is not intended as a limitation on the scope. | An apparatus for sterilizing or disinfecting a device has a chamber, a source of sterilant or disinfectant and ports for admitting and exhausting the sterilant or disinfectant but lacks a source of sterile rinse. A related method similarly lacks the step of rinsing with a sterile solvent yet leaves the device essentially free of the sterilant or disinfectant. Preferably the sterilant or disinfectant is removed from the device by vaporizing it and drawing it out of the chamber. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuing application of U.S. application Ser. No. 10/788,833, filed on Feb. 27, 2004 for “System And Method For Downhole Operation Using Pressure Activated Valve And Sliding Sleeve,” now issued as U.S. Pat. No. 7,152,678, and which claims benefit of and priority to U.S. patent application Ser. No. 10/004,956, now issued as U.S. Pat. No. 6,722,440, which claims benefit of and priority to U.S. Provisional Application Ser. No. 60/251,293, filed Dec. 5, 2000 for “Multi-Zone Completion Strings And Methods For Multi-Zone Completions,” the disclosures and teachings of all of which are hereby incorporated by reference for all purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the field of well completion assemblies for use in a wellbore. More particularly, the invention provides a method and apparatus for completing and producing from multiple mineral production zones, independently or in any combination.
[0003] The need to drain multiple-zone reservoirs with marginal economics using a single well bore has driven new downhole tool technology. While many reservoirs have excellent production potential, they cannot support the economic burden of an expensive deepwater infrastructure. Operators needed to drill, complete and tieback subsea completions to central production facilities and remotely monitor, produce and manage the drainage of multiple horizons. This requires rig mobilization (with its associated costs running into millions of dollars) to shut off or prepare to produce additional zones from the central production facility.
[0004] Another problem with existing technology is its inability to complete two or more zones in a single well while addressing fluid loss control to the upper zone when running the well completion hardware. In the past, expensive and often undependable chemical fluid loss pills were spotted to control fluid losses into the reservoir after perforating and/or sand control treatments. A concern with this method when completing upper zones is the inability to effectively remove these pills, negatively affecting the formation and production potential and reducing production efficiency. Still another problem is economically completing and producing from different production zones at different stages in a process, and in differing combinations. The existing technology dictates an inflexible order of process steps for completion and production.
[0005] Prior systems required the use of a service string, wire line, coil tubing, or other implement to control the configuration of isolation valves. Utilization of such systems involves positioning of tools down-hole. Certain disadvantages have been identified with the systems of the prior art. For example, prior conventional isolation systems have had to be installed after the gravel pack, thus requiring greater time and extra trips to install the isolation assemblies. Also, prior systems have involved the use of fluid loss control pills after gravel pack installation, and have required the use of through-tubing perforation or mechanical opening of a wireline sliding sleeve to access alternate or primary producing zones. In addition, the installation of prior systems within the wellbore require more time consuming methods with less flexibility and reliability than a system which is installed at the surface. Each trip into the wellbore adds additional expense to the well owner and increases the possibility that tools may become lost in the wellbore requiring still further operations for their retrieval.
[0006] While pressure actuated valves have been used in certain situations, disadvantages have been identified with such devices. For example, prior pressure actuated valves had only a closed position and an open position. Thus, systems could not reliably use more than one such valve, since the pressure differential utilized to shift the first valve from the closed position to the open would be lost once the first valve was opened. Therefore, there could be no assurance all valves in a system would open.
[0007] There has therefore remained a need for an isolation system for well control purposes and for wellbore fluid loss control, which combines simplicity, reliability, safety and economy, while also affording flexibility in use.
SUMMARY OF THE INVENTION
[0008] One aspect of the inventions disclosed and taught herein includes an isolation system for a subterranean well, comprising an isolation pipe; and a valve assembly coupled to the isolation pipe and comprising a pressure activated valve and a tool shiftable valve, wherein the valve assembly provides at least two independent flow paths in to and/or out of the isolation pipe
[0009] Another aspect of the inventions disclosed and taught herein includes a method for isolating a production zone of a well, comprising inserting a pipe into the well, the pipe having a valve assembly comprising a pressure activated valve and a tool shiftable valve; shifting the tool shiftable valve while the valve assembly is disposed in the well; then opening the pressure activated valve by pressurized fluid acting on the pressure activated valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention is better understood by reading the following description of non-limitative embodiments with reference to the attached drawings wherein like parts in each of the several figures are identified by the same reference characters, and which are briefly described as follows.
[0011] FIGS. 1A through 11 illustrate a cross-sectional, side view of first and second isolation strings.
[0012] FIGS. 2A through 2L illustrate a cross-sectional, side view of first, second and third isolation strings, wherein the first and second strings co-mingle production fluids.
[0013] FIGS. 3A through 3K illustrate a cross-sectional, side view of first, second and third isolation strings, wherein the second and third strings co-mingle production fluids.
[0014] FIGS. 4A through 4N illustrate a cross-sectional, side view of first, second, third and fourth isolation strings, wherein the first and second strings co-mingle production fluids and the third and fourth strings co-mingle production fluids.
[0015] FIGS. 5A through 5E are a cross-sectional side view of a pressure actuated device (PAD) valve shown in an open configuration.
[0016] FIGS. 6A through 6E are a cross-sectional side view of the PAD valve of FIG. 5A through 5E shown in a closed configuration so as to restrict flow through the annulus.
[0017] FIGS. 7A through 7D are a side, partial cross-sectional, diagrammatic view of a pressure actuated circulating (PAC) valve assembly in a locked-closed configuration. It will be understood that the cross-sectional view of the other half of the production tubing assembly is a mirror image taken along the longitudinal axis.
[0018] FIGS. 8A through 8D illustrate the isolation system of FIG. 7 in an unlocked-closed configuration.
[0019] FIGS. 9A through 9D illustrate the isolation system of FIG. 8 in an open configuration.
[0020] FIG. 10 is a cross-sectional, diagrammatic view taken along line A-A of FIG. 9C showing the full assembly.
[0021] FIGS. 11A through 11D illustrate a cross-sectional side view of a first isolation string.
[0022] FIGS. 12A through 12I illustrate a cross-sectional side view of a second isolation string stung into the first isolation string shown in FIG. 11 .
[0023] FIGS. 13A through 13L illustrate a cross-sectional side view of a third isolation string stung into the second isolation string shown in FIG. 12 , wherein the first isolation string is also shown.
[0024] FIGS. 14A through 14L illustrate a cross-sectional side view of the first, second and third isolation strings shown in FIGS. 11 through 13 , wherein a production string is stung into the third isolation string.
[0025] 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, as the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0026] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
[0027] Referring to FIGS. 1A through 1I , there is shown a system for production over two separate zones. A first isolation string 11 is placed adjacent the first production zone 1 . A second isolation string 22 extends across the second production zone 2 . The first isolation string 11 enables gravel pack, fracture and isolation procedures to be performed on the first production zone 1 before the second isolation string 22 is placed in the well. After the first production zone 1 is isolated, the second isolation string 22 is stung into the first isolation string 11 . Without running any tools on wire line or coil tubing to manipulate any of the valves, the second isolation string 22 enables gravel pack, fracture and isolation of the second production zone 2 . The first and second isolation strings 11 and 22 operate together to allow simultaneous production of zones 1 and 2 without co-mingling the production fluids. The first production zone 1 produces fluid through the interior of the production pipe or tubing 5 while the second production zone 2 produces fluid through the annulus between the production tubing 5 and the well casing (not shown).
[0028] The first isolation string 11 comprises a production screen 15 which is concentric about a base pipe 16 . At the lower end of the base pipe 16 there is a lower packer 10 for engaging the first isolation string 11 in the well casing (not shown). Within the base pipe 16 , there is a isolation or wash pipe 17 which has an isolation valve 18 therein. A pressure-actuated device (PAD) valve 12 is attached to the tops of both the base pipe 16 and the isolation pipe 17 . The PAD valve 12 allows fluid communication through the annuluses above and below the PAD valve. A pressure-actuated circulating (PAC) valve 13 is connected to the top of the PAD valve 12 . The PAC valve allows fluid communication between the annulus and the center of the string. Further, an upper packer 19 is attached to the exterior of the PAD valve 12 through a further section of base pipe 16 . This section of base pipe 16 has a cross-over valve 21 which is used to communicate fluid between the inside and outside of the base pipe 16 during completion operations.
[0029] Once the first isolation string 11 is set in the well casing (not shown) by engaging the upper and lower packers 19 and 10 , fracture and gravel pack operations are conducted or may be conducted on the first production zone. To perform a gravel pack operation, a production tube (not shown) is stung into the top of a sub 14 attached to the top of the PAC valve 13 . Upon completion of the gravel pack operation, the isolation valve 18 and the PAD valve 12 are closed to isolate the first production zone 1 . The tubing is then withdrawn from the sub 14 . The second isolation string 22 is then stung into the first isolation string 11 . The second isolation string comprises a isolation pipe 27 which stings all the way into the sub 14 of the first isolation string 11 . The second isolation string 22 also comprises a base pipe 26 which stings into the upper packer 19 of the first isolation string 11 . The second isolation string 22 also comprises a production screen 25 which is concentric about the base pipe 26 . A PAD valve 23 is connected to the tops of the base pipe 26 and isolation pipe 27 . The isolation pipe 27 also comprises isolation valve 28 . Attached to the top of the PAD valve 23 is a sub 30 and an upper packer 29 which is connected through a section of pipe. Production tubing 5 is shown stung into the sub 30 . The section of base pipe 26 between the packer 29 and the PAD valve 23 also comprises a cross-over valve 31 .
[0030] Since the second isolation string 22 stings into the upper packer 19 of the first isolation string 11 , it has no need for a lower packer. Further, since the first isolation string 11 has been gravel packed and isolated, the second production zone 2 may be fractured and gravel packed independent of the first production zone 1 . As soon as the completion procedures are terminated, the isolation valves 28 and the PAD valve 23 are closed to isolate the second production zone 2 .
[0031] The production tubing 5 is then stung into the sub 30 for production from either or both of zones 1 or 2 . For example, production from zone 1 may be accomplished simply by opening isolation valve 18 and allowing production fluid from zone 1 to flow through the center of the system up through the inside of production tubing 5 . Alternatively, production from only zone 2 may be accomplished by opening isolation valve 28 to similarly allow production fluids from zone 2 to flow up through the inside of production tubing 5 .
[0032] Non-commingled simultaneous production is accomplished by closing isolation valve 18 and opening PAD valve 12 and PAC valve 13 to allow zone 1 production fluids to flow to the inside of the system and up through the center of production tubing 5 . At the same time, PAD valve 23 may be opened to allow production fluids from zone 2 to flow through the annulus between production tubing 5 and the casing.
[0033] The first isolation string 11 comprises a PAD valve 12 and a PAC valve 13 . The second isolation string 22 comprises a PAD valve 23 but does not comprise a PAC valve. PAD valves enable fluid production through the annulus formed on the outside of a production tube. PAC valves enable fluid production through the interior of a production tube. These valves are discussed in greater detail below.
[0034] Referring to FIGS. 2A through 2L , an isolation system is shown comprising three separate isolation strings. In this embodiment of the invention, the first production string 11 comprises a lower packer 10 and a base pipe 16 which is connected to the lower packer 10 . A production screen 15 is concentric about the base pipe 16 . A isolation pipe 17 extends through the interior of the base pipe 16 and has an isolation valve 18 thereon. The PAD valve 12 of the first isolation string is attached to the tops of the base pipe 16 and isolation pipe 17 . In this embodiment of the invention, a sub 14 is attached to the top of the PAD valve 12 . The first isolation string 11 also comprises an upper packer 19 which is connected to the top of the PAD valve 12 through a length of base pipe 16 . The length of base pipe 16 has therein a cross-over valve 21 .
[0035] The second isolation string 22 is stung into the first isolation string 11 and comprises a base pipe 26 with a production screen 25 therearound. Within the base pipe 26 , there is a isolation pipe 27 which is stung into the sub 14 of the first isolation string 11 . The isolation pipe 27 comprises isolation valve 28 . Further, the base pipe 26 is stung into the packer 19 of the first isolation string 11 . The second isolation string 22 comprises a PAD valve 23 which is attached to the tops of the base pipe 26 and isolation pipe 27 . A PAC valve 24 is attached to the top of the PAD valve 23 . Further, a sub 30 is attached to the top of the PAC valve 24 . An upper packer 29 is attached to the top of the PAD valve 23 through a section of base pipe 26 which further comprises a cross-over valve 31 .
[0036] The third isolation string 32 is stung into the top of the second isolation string 22 . The third isolation string 32 comprises a base pipe 36 with a production screen 35 thereon. Within the base pipe 36 , there is a isolation pipe 37 which has an isolation valve 38 therein. Attached to the tops of the base pipe 36 and isolation pipe 37 , there is a PAD valve 33 . A sub 40 is attached to the top of the PAD valve on the interior, and a packer 39 is attached to the exterior of the PAD valve 33 through a section of base pipe 36 . A production tubing 5 is stung into the sub 40 .
[0037] The first isolation string 11 comprises a PAD valve 12 but does not comprise a PAC valve. The second isolation string 22 comprises both a PAD valve 23 and a PAC valve 24 . The third isolation string 32 only comprises a PAD valve 33 but does not comprise a PAC valve. This production system enables sequential grave pack, fracture and isolation of zones 1 , 2 and 3 . Also, this system enables fluid from production zones 1 and 2 to be co-mingled and produced through the interior of the production tubing, while the fluid from the third production zone is produced through the annulus around the exterior of the production tube.
[0038] The co-mingling of fluids produced by the first and second production zones is effected as follows: PAD valves 12 and 23 are opened to cause the first and second production zone fluids to flow through the productions screens 15 and 25 and into the annulus between the base pipes 16 and 26 and the isolation pipes 17 and 27 . This co-mingled fluid flows up through the opened PAD valves 12 and 23 to the bottom of the PAC valve 24 . PAC valve 24 is also opened to allow this co-mingled fluid of the first and second production zones 1 and 2 to flow from the annulus into the center of the base pipes 16 and 26 and the sub 30 . All fluid produced by the first and second production zones through the annulus is forced into the production tube 5 interior through the open PAC valve 24 .
[0039] Production from the third production zone 3 is effected by opening PAD valve 33 . This allows production fluids to flow up through the annulus between the base pipe 36 and the isolation pipe 37 , up through the PAD valve 33 and into the annulus between the production tube 5 and the well casing (not shown).
[0040] Referring to FIGS. 3A through 3K , a system is shown wherein a first isolation string 11 comprises a PAD valve 12 and a PAC valve 13 . This first isolation string 11 is similar to that previously described with reference to FIG. 1 . The second isolation string 22 comprises only a PAD valve 23 and is similar to the second isolation string described with reference to FIG. 1 . The third isolation string 32 comprises only a PAD valve 33 but no PAC valve and is also similar to the second isolation string described with reference to FIG. 1 . This configuration enables production from zone 1 to pass through the PAC valve into the interior of the annulus of the production tubing. The fluids from production zones two and three co-mingle and are produced through the annulus about the exterior of the production tube.
[0041] The co-mingling of fluids produced by the second and third production zones is effected as follows: Opening PAD valves 23 and 33 creates an unimpeded section of the annulus. Fluids produced through PAD valves 23 and 33 are co-mingled in the annulus.
[0042] Referring to FIGS. 4A through 4N , a system is shown comprising four isolation strings. The first isolation string 11 comprises a PAD valve 12 but no PAC valve. The second isolation string 22 comprises a PAD valve 23 and a PAC valve 24 . The third isolation string 32 comprises a PAD valve 33 but does not comprise a PAC valve. Similarly the fourth isolation string 42 comprises a PAD valve 43 but does not comprise a PAC valve. In this particular configuration, production fluids from zones one and two are co-mingled for production through the PAC valve into the interior of the production tube 5 . The fluids from production zones three and four are co-mingled for production through the annulus formed on the outside of the production tube 5 .
[0043] In this embodiment, the first isolation string 11 is similar to the first isolation string shown in FIG. 2 . The second isolation string 22 is also similar to the second isolation string shown in FIG. 2 . The third isolation string is also similar to the third isolation string shown in FIG. 2 . However, rather than having a production tubing 5 stung into the top of the third isolation string, the embodiment shown in FIG. 4 , comprises a fourth isolation string 42 . The fourth isolation string comprises a base pipe 46 with a production screen 45 therearound. On the inside of the base pipe 46 , there is a isolation pipe 47 which has an isolation valve 48 . Attached to the tops of the base pipe 46 and the isolation pipe 47 , there is a PAD valve 43 . To the interior of the top of the PAD valve 43 , there is attached a sub 50 . To the exterior of the PAD valve 43 , there is attached through a section of base pipe 46 , an upper packer 49 , wherein the section of base pipe 46 comprises a cross-over valve 51 . A production tubing 5 is stung into the sub 50 .
[0044] Referring to FIGS. 5A through 5E and 6 A through 6 E, detailed drawings of a PAD valve are shown. In FIG. 5 , the valve is shown in an open position and in FIG. 6 , the valve is shown in a closed position. In the open position, the valve enables fluid communication through the annulus between the interior and exterior tubes of the isolation string. Essentially, these interior and exterior tubes are sections of the base pipe 16 and the isolation pipe 17 . The PAD valve comprises a shoulder 52 that juts into the annulus between two sealing lands 58 . The shoulder 52 is separated from each of the sealing lands 58 by relatively larger diameter troughs 60 . The internal diameters of the shoulder 52 and the sealing lands 58 are about the same. A moveable joint 54 is internally concentric to the shoulder 52 and the sealing lands 58 . The moveable joint 54 also has seals 56 which contact sealing lands 58 and the shoulder 52 . The movable joint 54 has a spanning section 62 and a closure section 64 , wherein the outside diameter of the spanning section 62 is less than the outside diameter of the closure section 64 .
[0045] The valve is in a closed position, when the valve is inserted in the well. The PAD valve is held in the closed position by a shear pin 55 . A certain change in fluid pressure in the annulus will cause the moveable joint 54 to shift, opening the PAD valve by losing the contact between the joint 54 and the shoulder 52 . Since the relative diameters of the spanning section 62 and closure section 64 are different, the annulus pressure acts on the moveable joint 54 to slide the moveable joint 54 to a position where the spanning section 62 is immediately adjacent the shoulder 52 . Since the outside diameter of the spanning section 62 is less than the inside diameter of the shoulder 52 , fluid flows freely around the shoulder 52 and through the PAD valve.
[0046] As shown in FIG. 6 , in the closed position, the PAD valve restricts flow through the annulus. Here, the PAD valve has contact between the shoulder 52 and the moveable joint 54 , forming a seal to block fluid flow through the annulus at the PAD valve.
[0047] Referring to FIGS. 7A through 7D , there is shown a production tubing assembly 110 according to the present invention. The production tubing assembly 110 is mated in a conventional manner and will only be briefly described herein. Assembly 110 includes production pipe 140 that extends to the surface and a production screen assembly 112 with PAC valve assembly 108 controlling fluid flow through the screen assembly. In a preferred embodiment production screen assembly 112 is mounted on the exterior of PAC valve assembly 108 . PAC valve assembly 108 is interconnected with production tubing 140 at the uphole end by threaded connection 138 and seal 136 . Similarly on the downhole end 169 , PAC valve assembly 108 is interconnected with production tubing extension 113 by threaded connection 122 and seal 124 . In the views shown, the production tubing assembly 110 is disposed in well casing 111 and has inner tubing 114 , with an internal bore 115 , extending through the inner bore 146 of the assembly.
[0048] The production tubing assembly 110 illustrates a single preferred embodiment of the invention. However, it is contemplated that the PAC valve assembly according to the present invention may have uses other than at a production zone and may be mated in combination with a wide variety of elements as understood by a person skilled in the art. Further, while only a single isolation valve assembly is shown, it is contemplated that a plurality of such valves may be placed within the production screen depending on the length of the producing formation and the amount of redundancy desired. Moreover, although an isolation screen is disclosed in the preferred embodiment, it is contemplated that the screen may include any of a variety of external or internal filtering mechanisms including but not limited to screens, sintered filters, and slotted liners. Alternatively, the isolation valve assembly may be placed without any filtering mechanisms.
[0049] Referring now more particularly to PAC valve assembly 108 , there is shown outer sleeve upper portion 118 joined with an outer sleeve lower portion 116 by threaded connection 128 . For the purpose of clarity in the drawings, these openings have been shown at a 45° inclination. Outer sleeve upper portion 118 includes two relatively large production openings 160 and 162 for the flow of fluid from the formation when the valve is in an open configuration. Outer sleeve upper portion 118 also includes through bores 148 and 150 . Disposed within bore 150 is shear pin 151 , described further below. The outer sleeve assembly has an outer surface and an internal surface. On the internal surface, the outer sleeve upper portion 118 defines a shoulder 188 ( FIG. 7C ) and an area of reduced wall thickness extending to threaded connection 128 resulting in an increased internal diameter between shoulder 188 and connection 128 . Outer sleeve lower portion 116 further defines internal shoulder 189 and an area of reduced internal wall thickness extending between shoulder 189 and threaded connection 122 . Adjacent threaded connection 138 , outer sleeve portion 118 defines an annular groove 176 adapted to receive a locking ring 168 .
[0050] Disposed within the outer sleeves is inner sleeve 120 . Inner sleeve 120 includes production openings 156 and 158 which are sized and spaced to correspond to production openings 160 and 162 , respectively, in the outer sleeve when the valve is in an open configuration. Inner sleeve 120 further includes relief bores 154 and 142 . On the outer surface of inner sleeve there is defined a projection defining shoulder 186 and a further projection 152 . Further inner sleeve 120 includes a portion 121 having a reduced external wall thickness. Portion 121 extends down hole and slidably engages production pipe extension 113 . Adjacent uphole end 167 , inner sleeve 120 includes an area of reduced external diameter 174 defining a shoulder 172 .
[0051] In the assembled condition shown in FIGS. 7A through 7D , inner sleeve 120 is disposed within outer sleeves 116 and 118 , and sealed thereto at various locations. Specifically, on either side of production openings 160 and 162 , seals 132 and 134 seal the inner and outer sleeves. Similarly, on either side of shear pin 151 , seals 126 and 130 seal the inner sleeve and outer sleeve. The outer sleeves and inner sleeve combine to form a first chamber 155 defined by shoulder 188 of outer sleeve 118 and by shoulder 186 of the inner sleeve. A second chamber 143 is defined by outer sleeve 116 and inner sleeve 120 . A spring member 180 is disposed within second chamber 143 and engages production tubing 113 at end 182 and inner sleeve 120 at end 184 . A lock ring 168 is disposed within recess 176 in outer sleeve 118 and retained in the recess by engagement with the exterior of inner sleeve 120 . Lock ring 168 includes a shoulder 170 that extends into the interior of the assembly and engages a corresponding external shoulder 172 on inner sleeve 120 to prevent inner sleeve 120 from being advanced in the direction of arrow 164 beyond lock ring 168 while it is retained in groove 176 .
[0052] The PAC valve assembly of the present invention has three configurations as shown in FIGS. 7 through 9 . In a first configuration shown in FIG. 7 , the production openings 156 and 158 in inner sleeve 120 are axially spaced from production openings 160 and 162 along longitudinal axis 190 . Thus, PAC valve assembly 108 is closed and restricts flow through screen 112 into the interior of the production tubing. The inner sleeve is locked in the closed configuration by a combination of lock ring 168 which prevents movement of inner sleeve 120 up hole in the direction of arrow 164 to the open configuration. Movement down hole is prevented by shear pin 151 extending through bore 150 in the outer sleeve and engaging an annular recess in the inner sleeve. Therefore, in this position the inner sleeve is in a locked closed configuration.
[0053] In a second configuration shown in FIGS. 8A through 8D , shear pin 151 has been severed and inner sleeve 120 has been axially displaced down hole in relation to the outer sleeve in the direction of arrow 166 until external shoulder 152 on the inner sleeve engages end 153 of outer sleeve 116 . The production openings of the inner and outer sleeves continue to be axial displaced to prevent fluid flow therethrough. With the inner sleeve axial displaced down hole, lock ring 168 is disposed adjacent reduced outer diameter portion 174 of inner sleeve 120 such that the lock ring may contract to a reduced diameter configuration. In the reduced diameter configuration shown in FIG. 8 , lock ring 168 may pass over recess 176 in the outer sleeve without engagement therewith. Therefore, in this configuration, inner sleeve is in an unlocked position.
[0054] In a third configuration shown in FIGS. 9A through 9D , inner sleeve 120 is axially displaced along longitudinal axis 190 in the direction of arrow 164 until production openings 156 and 158 of the inner sleeve are in substantial alignment with production openings 160 and 162 , respectively, of the outer sleeve. Axial displacement is stopped by the engagement of external shoulder 186 with internal shoulder 188 . In this configuration, PAC valve assembly 108 is in an open position.
[0055] In the operation of a preferred embodiment, at least one PAC valve according to the present invention is mated with production screen 112 and, production tubing 113 and 140 , to form production assembly 110 . The production assembly according to FIG. 7 with the PAC valve in the locked-closed configuration, is then inserted into casing 111 until it is positioned adjacent a production zone (not shown). When access to the production zone is desired, a predetermined pressure differential between the casing annulus 144 and internal annulus 146 is established to shift inner sleeve 120 to the unlocked-closed configuration shown in FIG. 8 . It will be understood that the amount of pressure differential required to shift inner sleeve 120 is a function of the force of spring 180 , the resistance to movement between the inner and outer sleeves, and the shear point of shear pin 151 . Thus, once the spring force and resistance to movement have been overcome, the shear pin determines when the valve will shift. Therefore, the shifting pressure of the valve may be set at the surface by inserting shear pins having different strengths.
[0056] A pressure differential between the inside and outside of the valve results in a greater amount of pressure being applied on external shoulder 186 of the inner sleeve than is applied on projection 152 by the pressure on the outside of the valve. Thus, the internal pressure acts against shoulder 186 of to urge inner sleeve 120 in the direction of arrow 166 to sever shear pin 151 and move projection 152 into contact with end 153 of outer sleeve 116 . It will be understood that relief bore 148 allows fluid to escape the chamber formed between projection 152 and end 153 as it contracts. In a similar fashion, relief bore 142 allows fluid to escape chamber 143 as it contracts during the shifting operation. After inner sleeve 120 has been shifted downhole, lock ring 168 may contract into the reduced external diameter of inner sleeve positioned adjacent the lock ring. Often, the pressure differential will be maintained for a short period of time at a pressure greater than that expected to cause the down hole shift to ensure that the shift has occurred. This is particularly important where more than one valve according to the present invention is used since once one valve has shifted to an open configuration in a subsequent step, a substantial pressure differential is difficult to establish.
[0057] The pressure differential is removed, thereby decreasing the force acting on shoulder 186 tending to move inner sleeve 120 down hole. Once this force is reduced or eliminated, spring 180 urges inner sleeve 120 into the open configuration shown in FIG. 9 . Lock ring 168 is in a contracted state and no longer engages recess 176 such the ring now slides along the inner surface of the outer sleeve. In a preferred embodiment spring 180 has approximately 300 pounds of force in the compressed state in FIG. 8 . However, varying amounts of force may be required for different valve configurations. Moreover, alternative sources other than a spring may be used to supply the force for opening. As inner sleeve 120 moves to the open configuration, relief bore 154 allows fluid to escape chamber 155 as it is contracted, while relief bores 148 and 142 allow fluid to enter the connected chambers as they expand.
[0058] Shown in FIG. 10 is a cross-sectional, diagrammatic view taken along line A-A of FIG. 9C showing the full assembly.
[0059] Although only a single preferred PAC valve embodiment of the invention has been shown and described in the foregoing description, numerous variations and uses of a PAC valve according to the present invention are contemplated. As examples of such modification, but without limitation, the valve connections to the production tubing may be reversed such that the inner sleeve moves down hole to the open configuration. In this configuration, use of a spring 180 may not be required as the weight of the inner sleeve may be sufficient to move the valve to the open configuration. Further, the inner sleeve may be connected to the production tubing and the outer sleeve may be slidable disposed about the inner sleeve. A further contemplated modification is the use of an internal mechanism to engage a shifting tool to allow tools to manipulate the valve if necessary. In such a configuration, locking ring 168 may be replaced by a moveable lock that could again lock the valve in the closed configuration. Alternatively, spring 180 may be disengageable to prevent automatic reopening of the valve.
[0060] Further, use of a PAC valve according to the present invention is contemplated in many systems. One such system is the ISO system offered by BJ Services Company, U.S.A. (successor to OSCA, Inc.) and described in U.S. Pat. No. 5,609,204; the disclosure therein is hereby incorporated by reference. A tool shiftable valve disclosed in the above patent is a type of isolation valve and may be utilized within the production screens to accomplish the gravel packing operation. Such a valve could be closed as the crossover tool string is removed to isolate the formation. The remaining production valves adjacent the production screen may be pressure actuated valves according to the present invention such that inserting a tool string to open the valves is unnecessary.
[0061] FIGS. 11 through 14 illustrate several steps in the construction of an isolation and production system according to an embodiment of the present invention.
[0062] FIGS. 11A through 11D show a first isolation string 211 . The isolation string comprises a PAD valve 212 . At the lower end of the isolation string 211 , there is a lower packer 210 and at the upper end of the isolation string 211 there is an upper packer 219 . A base pipe 216 is connected to the lower packer 210 and has a production screen 215 therearound. The isolation string 211 further comprises an isolation valve 218 on a isolation pipe 217 . The PAD valve 212 enables fluid communication through the annulus between the isolation pipe 217 and the isolation string 211 . The first isolation string 211 also comprises a sub 214 attached to the top of the PAD valve 212 . Further, in the base pipe section between the PAD valve 212 and the upper packer 219 , there is a cross-over valve 221 . This configuration of the first isolation string 211 enables the first production zone 1 to be fractured, gravel packed, and isolated through the first isolation string 211 . Upon completion of these procedures, the isolation valve 218 and PAD valve 212 are closed to isolate the production zone 1 .
[0063] FIGS. 12A through 121 show cross-sectional, side views of two isolation strings. In particular, a second isolation string 222 is stung inside an isolation string 211 . Isolation string 222 comprises a PAD valve 223 and a PAC valve 224 . The isolation string 211 , shown in this figure, is the same as the isolation string shown in FIG. 11 . After the gravel/pack and isolation function are performed on the first zone with the isolation string 211 , the isolation string 222 is stung into the isolation string 211 . The second isolation string 222 comprises a base pipe 226 having a production screen 225 therearound. The base pipe 226 is stung into the packer 219 of the first isolation string 211 . The second isolation string 222 also comprises a isolation pipe 227 which is stung into the sub 214 of the first isolation string 211 . The isolation pipe 227 also comprises an isolation valve 228 . At the tops of the base pipe 226 and isolation pipe 227 , there is connected a PAD valve 223 . A PAC valve 224 is connected to the top of the PAD valve 223 . Also, a sub 230 is attached to the top of the PAC valve 224 . An upper packer 229 is also connected to the exterior portion of the PAD valve 223 through a section of base pipe 226 which also comprises a cross-over valve 231 .
[0064] Referring to FIGS. 13A through 13L , the isolation strings 211 and 222 of FIG. 12 are shown. However, in this figure, a third isolation string 232 is stung into the top of isolation string 222 . In this particular configuration, isolation strings 211 and 222 produce fluid from respective zones 1 and 2 up through the annulus between the isolation strings and the isolation sleeves until the fluid reaches the PAC valve 224 . The co-mingled production fluid from production zones 1 and 2 pass through the PAC valve 224 into the interior of the production string. The production fluids from zone 3 is produced through the isolation string 232 up through the annulus between the isolation string 232 and the isolation pipe 237 . In the embodiment shown in FIG. 13 , the PAD valves 212 , 223 and 233 are shown in the closed position so that all three of the production zones are isolated. Further, the PAC valve 224 in isolation string 222 is shown in a closed position.
[0065] The third isolation string 232 comprises a base pipe 236 which is stung into the packer 229 of the second isolation string. The base pipe 236 also comprises a production screen 235 . Inside the base pipe 236 , there is a isolation pipe 237 which is stung into the sub 230 of the second isolation string 222 . The isolation pipe 237 comprises isolation valve 238 . A PAD valve 233 is connected to the tops of the base pipe 236 and isolation pipe 237 . A sub 234 is connected to the top of the PAD valve 233 . An upper packer 239 is also connected through a section of base pipe 236 to the PAD valve 233 . This section of base pipe also comprises a cross-over valve 241 .
[0066] Referring to FIGS. 14A through 14L , the isolation strings 211 , 222 and 232 of FIG. 13 are shown. In addition to these isolation strings, a production tube 240 is stung into the top of isolation string 232 . With the production tube 240 stung into the system, pressure differential is used to open PAD valves 212 , 223 , and 233 . In addition, the pressure differential is used to set PAC valve 224 to an open position. The opening of these valves enables co-mingled production from zones 1 and 2 through the interior of the production tube while production from zone 3 is through the annulus on the outside of the production tube 240 .
[0067] The packers, productions screens, isolations valves, base pipes, isolations pipes, subs, cross-over valves, and seals may be off-the-shelf components as are well known by persons of skill in the art.
[0068] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | An isolation system for producing oil and gas from one or more formation zones and methods of use are provided comprising one or more pressure activated and tool shiftable valve assemblies. The tool shiftable valve may be actuated before or after actuation of the pressure activated valve. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of co-pending application U.S. Ser. No. 11/089,069, filed Mar. 24, 2005, entitled “IMPROVED SEPARATOR FOR IMMISCIBLE LIQUIDS”, which claims the benefit of the filing date of copending provisional applications U.S. Ser. No. 60/556,832, filed Mar. 26, 2004, entitled “IMPROVED SEPARATOR FOR IMMISCIBLE LIQUIDS” and U.S. Ser. No. 60/582,993, filed Jun. 25, 2004, entitled “IMPROVED SEPARATOR FOR IMMISCIBLE LIQUIDS”.
STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Technical Field
[0004] This invention relates in general to a liquid separation devices and, more particularly, to a device for separating oils and/or grease from water.
[0005] 2. Description of the Related Art
[0006] In several industries, and in particular the food industry, there is a need to separate liquid greases, fats and oils from waste water prior to passing the water to the sewage system. The waste water could be, for example, discharge from a washing device for cleaning dinnerware and cooking utensils. If the greases and fats solidify in the sewage system, a blockage can occur which is expensive to remediate.
[0007] Additionally, there is a movement in many localities to recycle grease and oils.
[0008] A commercially available separation device of the type described in European Patent EP 890381 B1 is shown generally in FIGS. 1 a and 1 b . FIG. 1 a illustrates an exterior perspective view of the separation device 10 . Effluent (containing two or more immiscible liquids of different densities, typically water entrained with oil, grease dissolved fats and other particles) is received at inlet 12 providing a passage into housing 14 (including removable lid 15 ). Effluent is heated using a probe-type heater 16 , which is coupled to an electrical connection. As described below, the immiscible liquids separate within housing 14 , and the less dense material (e.g., grease and oils) empties into container 18 . The more dense liquid (e.g., water) is discharged from water outlet 20 . Silt may accumulate at the bottom of housing 14 . The silt may be periodically discharged through silt outlet 22 .
[0009] Operation of the separation device 10 is described in greater detail in connection with FIG. 1 b (as well as EP 890381 B1). FIG. 1 b illustrates a cross-sectional side view of the separation device 10 . A coarse filtration chamber 24 is defined between the housing 14 and control plate 25 , which extends the full width of the housing. As effluent enters the coarse filtration chamber 24 through inlet 12 , it passes through a filtering basket 26 (shown in greater detail in connection with FIG. 2 ), which filters out solid particles, such as undissolved fat and other food particles.
[0010] After passing through the basket 26 , the effluent enters the separation chamber 28 , defined by control plate 25 , control plate 30 (which extends the full width of the housing), top plate 32 and the bottom of housing 14 . There are two exits from the separation chamber: (1) through floating ball valve 34 and through passage 36 , disposed between the bottom of control plate 30 and the bottom of the housing 14 . Top plate 32 is angled upward from the bottom portion of control plate 25 towards control plate 30 .
[0011] Weir plate 38 , which extends the full width of the housing, defines a water (high density liquid) release chamber 40 , along with control plate 30 and the housing 14 . Outlet 20 is disposed through the housing.
[0012] In operation, as the effluent enters the separation chamber 28 , the lower density liquid (grease/oil) rises. The flow through the separation chamber 28 is set at a rate that allows the lower density liquid to separate from the water and float upwards to the surface of the water, where it is contained below the sloping top plate 32 .
[0013] The sloping top plate 32 forces the lower density liquid to accumulate at the entry to floating ball valve 34 . Floating ball valve 34 is shown in greater detail in connection with FIG. 4 . Floating ball valve 34 uses a ball that floats at the interface between the high density liquid and the low density liquid. When the high density liquid reaches a predetermined height, the ball rises to a height which stops flow from the separation chamber 28 to the container 18 .
[0014] As the water flows through the separator 10 , it must rise above the top of weir 38 in order to exit. Accordingly, the water in separation chamber 28 attempts to rise to approximately the same height. Since the top of the separation chamber 28 is below the top of weir plate 38 , the hydrostatic pressure of the upward force of the water will push the separated grease/oil at the top of the separation chamber 28 through valve 34 . The water, however, cannot pass through the valve 34 , because the floating valve will stop its passage. Hence, once all the separated grease/oil is forced out of the separation chamber, the valve will remain closed until more grease/oil accumulates.
[0015] The separated water passes through passage 36 , over weir plate 38 and out outlet 20 . Silt in the water tends to accumulate at the bottom of housing 14 , unable to rise over weir plate 38 . Silt valve 22 , located at the bottom of housing 14 , can be opened periodically, and the flow of water out of the valve will flush out the silt.
[0016] In many fields of use for the separator 10 , and in particular the food industry, it can be assumed that the employees who will operate and maintain the separator will be relatively transient between employers. Accordingly, aspects of the operation and maintenance of the separator must allow for unfamiliarity with details. Matters such as periodic cleaning of various components of the separator, such as the floating ball valve, if performed incorrectly, can lead to unwanted consequences, such as allowing water to exit into the oil/grease container or oil/grease flowing out of the outlet 20 .
[0017] Also, it would be beneficial to improve the flow of liquids through the separation chamber, since oil and grease are by their nature sticky and tend to accumulate on hard surfaces.
[0018] Accordingly, there is a need in the industry for an improved separator.
BRIEF SUMMARY OF THE INVENTION
[0019] In one aspect of the present invention, a separator for immiscible liquids comprises a tank having an inlet, an inlet chamber, a separation chamber and an outlet chamber, with the inlet feeding effluent into the inlet chamber, the inlet chamber being in communication with the separation chamber through a first passage and the separation chamber in being communication with the outlet chamber through a second passage. An oil/grease outlet valve is replaceably disposed in a valve housing coupled to the separation chamber, the valve having an interlocking connection to the valve housing.
[0020] This aspect of the invention provides a valve that can be safely and efficiently cleaned and serviced.
[0021] In another aspect of the present invention, a separator for immiscible liquids comprises a tank having an inlet, an inlet chamber, a separation chamber and an outlet chamber, with the inlet feeding effluent into the inlet chamber, the inlet chamber being in communication with the separation chamber through a first passage and the separation chamber in being communication with the outlet chamber through a second passage. A ball valve is in communication with the separation chamber, with the ball valve including a container disposed within the separation chamber for containing a ball, where the container has at least one opening for allowing oil/grease from the separation chamber to pass through the ball valve.
[0022] This aspect of the invention prevents the ball from improperly closing the valve while the incoming effluent creates turbulence.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0023] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0024] FIGS. 1 a and 1 b illustrate a perspective view and a cross-sectional view of a prior art separation device;
[0025] FIG. 2 illustrates a prior art filtration basket used in the device of FIGS. 1 a and 1 b;
[0026] FIGS. 3 a through 3 d respectively illustrate perspective, top, cross-sectional front, and cross-sectional side views of an improved basket;
[0027] FIG. 4 illustrates a prior art floating ball valve used in the separation device of FIGS. 1 a and 1 b;
[0028] FIG. 5 a illustrates a cross-sectional view of an improved floating ball valve;
[0029] FIG. 5 b illustrates a perspective view of a housing for an improved floating ball valve;
[0030] FIG. 5 c illustrates a top view of the improved floating ball valve;
[0031] FIG. 5 d illustrates a side perspective view of an improved floating ball valve;
[0032] FIG. 6 a illustrate a block diagram of an improved valve for replacing the ball valve of FIG. 4 ;
[0033] FIGS. 6 b through 6 d illustrate cross-sectional view of butterfly, gate and ball valves, respectively;
[0034] FIGS. 7 a through 7 c illustrates an improved separation device with low friction surfaces, improved heating and silt removal, and leakage prevention;
[0035] FIG. 8 illustrates an improved separation device that can be used in an in-ground installation;
[0036] FIG. 9 illustrates a tool for cleaning the separation device of FIG. 8 ;
[0037] FIG. 10 illustrates a separation device combined with a large capacity storage container for unified grease control;
[0038] FIG. 11 illustrates a bidirectional separation device;
[0039] FIG. 12 illustrates an embodiment using a breather tube for eliminating trapped air in the separation chamber;
[0040] FIGS. 13 a and 13 b illustrate a cross-sectional side view and a top view, respectively, of an embodiment of a ball valve with an integral breather tube; and
[0041] FIG. 14 illustrates another embodiment of an in-ground separator 200 .
DETAILED DESCRIPTION OF THE INVENTION
[0042] The present invention is best understood in relation to FIGS. 1-14 of the drawings, like numerals being used for like elements of the various drawings.
[0043] FIG. 2 illustrates a prior art filtration basket 26 . The basket has a front side (facing the housing at inlet 12 ) and a back side (facing control plate 25 ) that is perforated with holes 50 , as is the bottom of the basket. Since the front side is relatively flush with housing 14 and the back side is relatively flush with control plate 25 , and the ends are not perforated, almost all of the effluent flow is through the holes in the bottom of the basket. Over time, food particles will accumulate on the bottom of the basket 26 , severely limiting flow into the separation chamber 28 .
[0044] Other problems concern removal and replacement of the basket 26 . The prior art uses a handle 52 which terminates through holes on either side of the basket. The basket 26 has flanges 54 on either side; flanges 54 normally rest on support clips 56 formed on either side of the housing in the coarse filtration chamber 24 . In order to accommodate the exposed ends of the handle 52 when the basket is removed or replaced, slots 58 are formed in support clips 56 through which the ends of the handle may pass.
[0045] During operation, the slots 58 prevent a complete seal between flanges 54 and support clips 56 . Some of food particle in the effluent may pass through the slots 58 , bypassing basket 26 . Food particles may also pass through the narrow gap between the front edge of the basket and the outer body 14 and the rear edge of the basket and the control plate 25 . Excessive food particles entering the separation chamber 28 can clog the floating ball valve 34 , resulting in water passing into the oil collection chamber 18 .
[0046] FIGS. 3 a through 3 d illustrate perspective, top, cross-sectional front and cross-sectional side views of an improved basket 60 . The improved basket increases efficient effluent flow, eliminates solid particles in the effluent from bypassing the filtration mechanism of the basket, and enhances effluent separation in the separation chamber 28 .
[0047] As distinguished from the vertical sides of basket 26 , tapered basket 60 has tapered sides that angle away from housing 14 and control plate 25 . Further, all four sides are perforated. Accordingly, a larger surface area of the basket is separated from a constricting wall for more efficient flow through the basket 60 . Since there is more area for holes 62 , the holes 62 can have a smaller diameter, without affecting flow of effluent through the basket. In the prior art, holes 50 had a diameter of approximately 11/64 inches, while holes 62 can have a diameter of approximately 1/16 inches (0.15875 cm). This allows smaller particles to be trapped by the basket 60 for more effective coarse filtering. Further, more debris may be collected before the basket needs to be emptied, since the basket will continue to efficiently filter the effluent even when the bottom is covered.
[0048] An additional improvement is the addition of inclined baffle plate 64 to the basket 60 . Baffle plate 64 deflects water from inlet 12 towards the bottom of the basket 60 . A cut-out 64 a in the baffle plate 64 faces inlet 12 . As effluent enters the coarse filtering chamber 24 , the baffle directs the effluent downwards to help drive oils and grease under the control plate 25 . Further, as effluent hits the baffle plate 64 , it is driven through a layer of oil, which helps to saturate the chemical emulsions, causing the emulsions to release the oil.
[0049] The handle 68 of basket 60 is attached to the top of the baffle plate 64 . Because the handle does not protrude from the sides of the basket 60 , the slots 58 , shown in FIG. 2 are no longer necessary.
[0050] With the addition of the baffle plate 64 , it is important that the basket 60 is oriented correctly (such that the baffle plate deflects effluent downward, not upward). A careless replacement of the basket 60 could thus cause problems with the operation of the separator 10 . To prevent an errant replacement, the basket 60 has asymmetric flanges 54 a and 54 b . As shown in FIGS. 3 a - d , flange 54 a is wider than 54 b , and support clip 56 a is wider than 56 b . If the basket 60 is replaced in the reverse orientation, the mismatch between the support clips 56 a - b and flanges 54 a - b will not allow the basket to seat properly (and the lid will not be able to close). This will notify the operator that the basket needs to be reversed. Front and back flanges 54 c and 54 d provide an integral lip that completely surrounds the basket 60 for a complete seal.
[0051] FIG. 4 illustrates a type of floating ball valve 34 used in the prior art. Floating ball valve 34 includes a ball 70 within housing 72 . Ball 70 is held within housing 72 by a grid 74 . Insert 76 includes a mating portion 78 for mating with the housing 72 above the ball 70 and an outlet portion 79 for communicating with the oil/grease container 18 . A passage 80 is formed in insert 76 through the mating portion 78 and outlet portion 79 , with a tapered opening 82 at the end of the passage 80 . Passage 80 is coupled to outlet 84 . O-ring 86 seals mating portion 78 and housing 72 . As described above, the ball 70 is designed to float at the interface between two immiscible liquids (e.g., water and oil/grease). As the water rises, the oil/grease is pushed into passage 80 , where it exits to the oil/grease container 18 via outlet 84 . Once all of the lower density liquid (oil/grease) has been pushed into the passage 80 , the ball 70 presses against the tapered opening 82 , thereby closing the passage. In this way, only the lower density liquid can pass through the passage 80 .
[0052] Since the oils and grease will pass through the passages 80 and 84 to the oil/grease container 18 , the passages 80 and 84 need to be cleaned periodically to remove congealed substances. To do so, a brush is inserted into the passage 80 from above or passage 84 from the side and an up and down scrubbing motion is used to dislodge the congealed oil/grease within the passage 80 . During the cleaning process, the mating portion 78 can easily become dislodged from the housing 72 , causing failure of the valve 34 .
[0053] FIG. 5 a illustrates a cross-sectional side view of an improved floating ball valve 90 , which can be used in place of floating ball valve 34 . Floating ball valve 90 includes a mating portion 78 , with two protruding locking pins 92 . Housing 72 includes two vertical channels 94 forming L-shapes with respective horizontal channels 96 (see FIG. 5 b ) to accept pins 92 . The mating portion 78 is engaged within housing 72 by aligning the pin 92 with vertical channel 94 , inserting the mating portion 78 into the housing 72 until pin 92 reaches the end of the vertical channel 94 , then rotating the pin within the horizontal channel 96 to lock the mating portion within the housing 72 .
[0054] FIG. 5 b shows a perspective view of housing 72 , illustrating the vertical channel 94 and horizontal channel 96 . FIG. 5 c illustrates the insert 76 in a locked position within housing 72 .
[0055] FIG. 5 d illustrates a side view of a ball valve 210 . Ball valve 210 uses an open container, such as cage 212 , coupled to valve housing 214 to hold the ball 70 . The open container could be a many different designs, but it must be open enough to let the oil/grease flow into the container easily, yet restrictive enough to contain the ball from falling into the separation chamber. The interface 216 between the cage 212 and the valve housing 214 is situated at the top plate 32 . Within the housing, there is a mating portion 78 with a passage 80 , opening 82 and outlet 84 , which can be constructed similar to that shown in connection with FIG. 5 a - c . The difference is that the grid 74 of FIGS. 5 a - c , which is co-planar with the top plate 32 , is replaced by a downward protruding cage 212 (or other open structure for holding ball 70 ).
[0056] With a co-planar grid 74 , such as that shown in connection with FIGS. 5 a - c , during a rush of effluent into the separation chamber, turbulence can occur in the oil/grease layer at the grid 74 , causing the ball 70 to be lifted into the opening 82 , thereby closing the opening 82 . During this time, the oil/grease cannot flow through the passage 80 . If the ball is held against the opening 82 for a sufficient time period, oil/grease may be forced around control plate 30 and into release chamber 40 . The ball 70 will not drop until the flow stops. Another rush of incoming effluent can cause the same occurrence, with the ball improperly closing the valve.
[0057] In the embodiment shown in connection with FIG. 5 d , however, the ball cannot be lifted to and held against the opening 82 by turbulence at the surface of the oil/grease layer. The projection of the cage 212 into the separation chamber increases the distance between the opening 82 and the ball 70 , without affecting the relative levels of the valve 210 and control plate 30 which are critical to operation of the separator 10 . In the preferred embodiment, in a resting position, the ball should need to rise about two inches to close the valve.
[0058] Another problem associated with floating ball valve 34 is the problems which can occur if the ball 70 sticks to the mating portion 82 . This is possible because of the oil/grease that will coat both surfaces during normal operation of the separator 10 .
[0059] FIG. 6 a illustrates a schematic of an alternative embodiment of a valve which can be used to eliminate the need for a floating ball. In FIG. 6 a , a sensor 100 senses the location of the interface between the two immiscible liquids. When the interface has reached a predetermined level, the sensor sets a control signal to actuator 102 . Responsive to the control signal, the actuator closes a valve 104 which controls flow between an oil/grease inlet 106 and an oil/grease outlet 108 .
[0060] FIGS. 6 b through 6 d illustrate three types of valves that could used implement valve 104 (other valve types could be used as well). FIG. 6 b illustrates a cross-sectional side view of a butterfly valve 110 . The butterfly valve operates by rotating a disk 114 within cylindrical housing 112 . When surface the disk 114 is aligned parallel to the axis of the cylindrical housing, the valve 110 is in an open state; when the surface of the disk 114 is perpendicular to the axis of the cylindrical housing 112 , the valve 110 is in a closed state.
[0061] FIG. 6 c illustrates a cross-sectional side view of a gate valve 120 . In a gate valve, a gate 122 is positioned within tube 124 to prevent flow and withdrawn from tube 124 to allow flow.
[0062] FIG. 6 d illustrates a cross-sectional side view of a ball valve 130 (not to be confused with the floating ball valve 34 ). The ball valve incorporates a sphere 132 with a cylindrical bore 134 disposed through the center of the sphere. When the bore is aligned with the inlet 136 and outlet 138 , liquid can pass from inlet to outlet. When the bore 134 is rotated to a position where it does not communicate between inlet 136 and outlet 138 , liquid can no longer pass through the valve.
[0063] The ball valve 130 is a preferred embodiment for the present invention, because the operation of the valve rotating between opened and closed positions tends to scrape away congealed oil/grease at the inlet and outlet. Therefore, this valve is somewhat self-cleaning.
[0064] FIG. 7 a illustrates improvements made to the separator 10 to improve flow of the liquids (and silt) inside the separation chamber for improved operation. First, the inside of housing 14 and surfaces of control plate 25 , top plate 32 , control plate 30 and weir 38 can be coated with a Teflon layer 39 , or another non-stick coating layer 39 , in improve flow and reduce friction and adhesion between the oil/grease/silt and these surfaces.
[0065] Additionally, FIG. 7 a illustrates improvements made to heating of the liquids, particularly in the separation chamber 28 . In the prior art, a probe-type heating element has been used. This presents several problems. First, the heater is mounted to the outside of the unit, where it can be inadvertently hit by employees, and knocked loose. Second, the surface area of the heater is relatively small and, therefore, the heat is localized.
[0066] In FIG. 7 a , several alternatives are shown for heating the liquids in the separation chamber 28 . These alternatives could be used separately or combined. The first alternative uses a heating blanket 140 disposed on the bottom of housing 14 . This eliminates any protruding housing for the heater and heats a larger surface area, keeping the temperatures relative constant across the separation chamber 28 .
[0067] A second alternative uses induction heating to heat the top plate 32 and/or valve 34 . Since the top plate 32 and valve 34 are in nearly constant contact with the oil/grease, these elements can be heated by induction to most effectively provide heat for keeping the oil/grease as liquid as possible. The induction heating of the top plate 32 and/or valve 34 could be used in conjunction with the heat blanket 140 .
[0068] Additionally, in FIG. 7 a , a self-closing valve 147 is used as the silt valve. The valve 147 is held open manually long enough (generally about ten seconds) for the silt to be forced out by the pressure of water in the chamber and will close immediately the operator's hand is removed from the valve handle. This protects the device from being operated with the silt valve open, which could allow effluent to pass directly out the silt valve; this could cause the heater to overheat and to burn out and/or cause the oil to overheat and smoke.
[0069] FIGS. 7 a , 7 b and 7 c illustrate top and bottom seals used in the improved separator. A top seal 142 is formed on the perimeter of the housing 14 and on the tops of control plates 25 and 30 , providing a continuous seal. In the preferred embodiment, the seal 142 is mechanically attached to the housing 14 and control plates in the manner shown in FIG. 7 c . In FIG. 7 c , the seal material, preferably in the form of a hollow neoprene tube or similar flexible hollow tubing, is affixed to an edge of the housing 14 and control plates 25 and 30 using a mechanical gripping mechanism 144 . In the illustrated embodiment, the mechanical gripping mechanism includes teeth 146 which, when pushed onto the housing edges, will grab the edges to form a strong mechanical bond. Any gaps between strips of materials should be filled with a sealing compound.
[0070] In operation, the top seal 142 can withstand considerable water pressure with just the weight of the lid 15 maintaining contact with the seal 142 . Thus, if an surge of water is received through inlet 20 , water is maintained within the housing 14 , and is kept from overflowing from either the coarse filtration chamber 24 or the water release chamber 40 into the interior chamber 148 of the housing 14 , where it can become rancid.
[0071] Prior art mechanisms use a compressive foam that is affixed to the lower edge of the lid by means of a self adhesive strip, and a seal is created by the use of lid clamps to hold the lid to the body. The claims make the user access to the unit difficult. Also, the clamped lid discourages the operators from properly maintaining the unit.
[0072] An additional bottom seal 149 is affixed around the bottom edge of the housing 14 . Once again, the bottom seal 149 is preferably in the form of a hollow neoprene tube affixed to the edges of the housing 14 using a mechanical gripping mechanism 144 as shown in FIG. 7 c.
[0073] Prior art methods for sealing the separator to a floor, such as by caulking, have adhesion problems, particularly in the grout lines. Since units will often be retrofit to existing restaurants, the grease embedded in the grout resists adhesion, allowing water from floor cleaning to seep under the unit. Also, caulking complicates moving of the unit. Placing the unit on legs such that the floor can be cleaned under the unit can add height to the unit, reducing the positive fall of the effluent from sink and dishwasher drains.
[0074] The bottom seal 149 has been shown to effectively seal the unit to the floor, and is particularly effective in sealing the grout lines, since the weight of the unit holds the bottom seal 149 firmly within the grout lines.
[0075] FIG. 8 illustrates an embodiment of a separator 150 which has the advantage that it can be used in an in-ground embodiment. For illustration purposes, separator 150 is shown with the prior art heater 16 and floating ball valve 34 , it being understood that the other improvements described herein could be used in the place of these elements.
[0076] In FIG. 8 , basket 60 performs coarse filtering on effluent received through inlet 12 . Control plate 25 has an angled portion 152 to provide an improved flow through basket 60 (this improvement can be used in other configurations as well). A downward sloping bottom control plate 154 has a V-shape (or channel) to catch silt, and is preferably Teflon coated. The V-shape bottom control plate transitions into weir 156 , maintaining a V-shape which is slanted upwards to the desired predetermined height to provide hydrostatic pressure on the separated oil at valve 34 . Control plate 158 , is coupled to the top of housing 14 and provides a channel 160 through which the separated water flows. Control plate 158 includes an enlarged portion 162 . Heater 16 is disposed through top plate 32 , within compartment 164 . Apart from compartment 164 , the area above top plate 32 can be used as a sump 166 to store oil/grease from oil/grease valve 34 , preferably in a removable container. Access to the tapered basket 60 , sump 166 , compartment 164 and oil valve 34 can be made by removing one or more lids (not shown) on the top of housing 14 . If silt is to be separate from the water, a water outlet 168 is placed above a silt valve 170 . Alternatively, a single outlet can be provided, which disposes of both water and silt. A mesh screen 172 is positioned in front of water outlet 168 to filter out silt.
[0077] In operation, silt from the effluent will gather at the bottom plate 154 , and will be drawn towards the lowest portion of the “V” shaped plate 154 at the interface with the weir 156 . The flow of water through channel 160 will push the silt up the channel 160 . The enlarged portion 162 of the channel will create turbulence and additional suction to pull silt up and over the top of weir 156 . Silt will fall to silt valve 170 , which can be periodically opened to a silt outlet or collected separately in a container coupled to the silt valve 170 . The remainder of the water flows out of water outlet 168 into the sewage system.
[0078] Over time, some silt may collect on weir 156 . FIG. 9 illustrates a scraper which matches the profile of weir 156 to remove this silt.
[0079] Preferably, all inside surfaces of separator 150 are Teflon coated to decrease resistance and improve flow.
[0080] FIG. 10 illustrates a diagram of a separator with a large grease container for containing both grease/oil separated from the effluent and for containing used grease/oil from operations, such as from frying machines. In this embodiment, an underground separator 150 (an above ground separator of the type shown in FIGS. 1-7 a - c could also be used) is coupled to a storage tank 170 which is large enough to hold all the discard oil/grease from effluent and operations. Pipe 173 couples the valve 34 to the storage tank 170 . Opening 174 allows workers to pour the oil/grease into the storage tank from an oil caddy, for example. Alternatively, the oil/grease from operations could be pumped directly to the tank 170 . Heater 176 heats the contained oil so that it does not solidify. Valve 178 , typically a quick disconnect valve, provides a suitable connection to an oil pump used to pump oil/grease from the tank 170 for reclamation. Pipe 180 is disposed between valve 178 and the bottom of the tank 170 .
[0081] In operation, the embodiment shown in FIG. 10 allows a business to consolidate all oil/grease waste for removal by a collection company, typically an outside contractor or municipality. The unified design allows the collection company to collect all of the used oil/grease from a restaurant. By using the underground configuration, oil drums/dumpsters could be eliminated from the back of the restaurant, or other business.
[0082] FIG. 11 illustrates an embodiment for an above-ground bidirectional separator 182 (with lid 15 removed), i.e., the valve 34 and heater 16 can be located on either side of the housing 14 . The housing 14 includes two oil valve housings 72 , one of which will receive a valve 34 and the other of which will have a plug installed. Container 18 is mounted through opening 186 on the side of the valve 34 , the other opening 186 is closed with a blank. The holes 186 have slotted holes adjacent to them to enable either the container 18 or support or blank plate to be mounted. Threaded connections 188 are made on either side of the housing 14 for receiving the heater 16 ; the side not receiving the heater is closed with a threaded plug.
[0083] The embodiment shown in FIG. 11 allows the separator 182 to be installed in either flow direction, which reduces the cost of inventory that must be maintained and allows the most efficient installation within a business. Further, the direction of the separator 182 can be switched if a kitchen is remodeled (on average, a commercial kitchen is remodeled every five years) to accommodate a change in flow through the pipes.
[0084] FIG. 12 illustrates an embodiment for eliminating trapped air in the separation chamber 28 . In certain circumstances, such as startup, a rush of effluent with entrained air bubbles into separation chamber 28 can cause the ball 70 to stick against tapered opening 82 (see FIG. 5 a ). As the entrained air bubbles separate from the effluent, they can hold the ball 70 against the tapered opening 82 causes the valve to remain closed. Daily cleaning of the valve has been found to reduce the problem, but as the entrapped air in the separation chamber 28 escapes through the valve, it propels the oil/grease in the valve at the person cleaning the valve.
[0085] In FIG. 12 , a breather tube 190 is in communication with the separation chamber 28 (in the illustrated embodiment, the breather tube 190 is disposed through the unused valve housing 72 , however it could be disposed through any suitable part of top plate 32 ). The breather tube 190 extends to near the lid 15 , such that hydrostatic pressure cannot force oil/grease out of the breather tube 190 . Alternatively, the breather tube 190 could feed into the ball valve, such that any oil/grease emitted from the breather tube 190 would be fed into the container 18 .
[0086] In operation, since the breather tube communicates directly with the separation chamber 28 , without a ball valve to interrupt communication, air can always pass out of the separation chamber through the breather tube 190 and therefore, the air will not cause the ball valve to close improperly.
[0087] It should be noted that animal fats may solidify in the breather tube 190 . Accordingly, the breather tube 190 should be kept hot by electrical trace and insulation, or by other methods.
[0088] FIGS. 13 a and 13 b illustrate a cross-sectional side view and a top view, respectively, of an embodiment of a ball valve 34 with an integral breather tube 190 . In this embodiment, a breather tube hole 191 is formed through mating portion 78 , with the tube 190 extending upwards from hole 191 to a level near lid 15 , or other level that will ensure that hydrostatic pressure will not force oil/grease out of the breather tube 190 . Additionally, FIGS. 13 a and 13 b illustrate outlet 84 as a trough, rather than a pipe. A trough configuration is generally easier to clean, and uses less material.
[0089] FIG. 14 illustrates another embodiment of an in-ground separator 200 . This embodiment is similar to the embodiment of FIG. 8 , with the container 18 locate above top plate 32 , such that it can be accessed by removing lid 15 . Heater 16 is located below top plate 32 and has extended portions 16 a to provide additional surface area for heating the effluent. The operation of the separator 200 is the same as described above.
[0090] This embodiment provides an in-ground separator that can be used, for example, inside a restaurant work area. The container can be easily accessed and removed for transporting the oil/grease to a storage container.
[0091] Although the Detailed Description of the invention has been directed to certain exemplary embodiments, various modifications of these embodiments, as well as alternative embodiments, will be suggested to those skilled in the art. The invention encompasses any modifications or alternative embodiments that fall within the scope of the Claims. | A separator provides improvements for better separation of an effluent into constituent parts and greater ease of use. A tapered basket provides improved flow and better filtration. A baffle directs effluent into the basket with greater force. An asymmetrical flange prevents mis-orientation the basket and baffle. An improved oil valve provides a locking mechanism to prevent dislodging of the valve during cleaning. An alternative valve uses a sensor to sense an oil/water interface and close the oil valve appropriately. A top seal prevents leakage of effluent at connection points with the lid of the housing. An underground unit allows below floor level installation of the separator. A bidirectional unit can be reversed to provide flow in either direction. A dual purpose tank can be used to store both separated oil and oil from operations for common removal. | 1 |
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