Patent US3851742A successfully refreshed from Google Patents.
US3851742A
Expired / Lapsed
US
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Control system for variable speed drive
Assignee: Sommer Co
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Filing: 1972-09-22
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Granted: 1974-12-03
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Expires: 1992-09-22
Abstract
Abstract A control system for a variable speed drive unit having an actuating piston for modulating the clamping pressure between a first series of discs mounted for rotation with an input shaft and a second series of plates carried by an output shaft and interleaved with the first series, the system comprising: a sensor associated with the output shaft for providing pulses representative of preselected increments of rotation thereof; a digital delay circuit for delaying the pulses by the period of repetition of a pulse at a desired speed for the drive, a comparator for receiving the delayed pulse and the next subsequent pulse from the sensor for providing output pulses with each pulse having a width representative of the time delay between the receipt of a respective pair of pulses and a polarity representative of whether the delayed pulse led or lagged the subsequent pulse from the sensor, and an integrator for integrating the pulses from the comparator to provide a control signal for a servo relief valve. The servo relief valve provides a variable restriction between a flow line and a fluid reservoir surrounding the plates and discs. The flow line is connected between a source of pressurized fluid and the actuating piston, and the pressure therein is varied by the valve in response to the control signal to control the speed of the output shaft. The discharge from the servo valve is directed to the first and second series of discs and plates, respectively, whereby to maintain viscous shear and also to transfer the heat generated by friction.
Inventors
- 👤 D Carlson
- 👤 G Sommer
- 👤 A Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:18
CPC Classifications
H; H02; H02P; H02P29/00; H02P29/0016; H02P29/0027; H02P23/00; H02P23/18; H02P23/186
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
331 words
A system for adjusting the rotational speed of a rotatable member to approach a desired rotational speed comprising: sensing means associated with said member for providing a sensing means train of pulses, each pulse of said sensing means train of pulses being representative of a predetermined increment of rotation of said member; delay means receiving said sensing means train of pulses as an input thereof and providing a delay means train of output pulses as an output thereof; speed reference means for providing a speed reference signal representative of the desired rotational speed of said member and for supplying said speed reFerence signal to said delay means; said delay means comprising means for causing each pulse of said delay means train of pulses to be delayed correlative to a corresponding pulse received from said sensing means for a delay period whose duration is inversely proportional to the desired rotational speed of said member over a range of desired rotational speeds; comparing means receiving said sensing means train of pulses and said delay means train of pulses for providing an output signal representative of the time interval between the receipt of respective pairs of said pulses of said delay means train of pulses and said sensing means train of pulses, each of said respective pair of said pulses of said delay means train of pulses and of said sensing means train of pulses including one pulse of said delay means train of pulses and a pulse of said sensing means train of pulses which is subsequent to that pulse of said sensing means train of pulses to which one pulse of said delay means train of pulses corresponds; and speed control means associated with said rotatable member for receiving said output signal of said comparing means and for controlling the rotational speed of said rotatable member in accordance with said output signal of said comparing means to cause the actual rotational speed of said rotatable member to approach its desired rotational speed.
Claim 2
Independent Claim
331 words
A system for adjusting the rotational speed of a rotatable member to approach a desired rotational speed comprising: sensing means associated with said member for providing a sensing means train of pulses, each pulse of said sensing means train of pulses being representative of a predetermined increment of rotation of said member; delay means receiving said sensing means train of pulses as an input thereof and providing a delay means train of output pulses as an output thereof; speed reference means for providing a speed reference signal representative of the desired rotational speed of said member and for supplying said speed reFerence signal to said delay means; said delay means comprising means for causing each pulse of said delay means train of pulses to be delayed correlative to a corresponding pulse received from said sensing means for a delay period whose duration is inversely proportional to the desired rotational speed of said member over a range of desired rotational speeds; comparing means receiving said sensing means train of pulses and said delay means train of pulses for providing an output signal representative of the time interval between the receipt of respective pairs of said pulses of said delay means train of pulses and said sensing means train of pulses, each of said respective pair of said pulses of said delay means train of pulses and of said sensing means train of pulses including one pulse of said delay means train of pulses and a pulse of said sensing means train of pulses which is subsequent to that pulse of said sensing means train of pulses to which one pulse of said delay means train of pulses corresponds; and speed control means associated with said rotatable member for receiving said output signal of said comparing means and for controlling the rotational speed of said rotatable member in accordance with said output signal of said comparing means to cause the actual rotational speed of said rotatable member to approach its desired rotational speed.
Claim 3
Dependent Claim
62 words
A system according to claim 1 wherein said respective pairs of pulses each comprises said one pulse of said delay means train of pulses and that one pulse of said sensing means train of pulses which is immediately subsequent to that pulse of said sensing means train of pulses to which said one pulse of said delay means train of pulses corresponds.
Claim 4
Dependent Claim
54 words
A system according to claim 2 wherein said delay means delays each pulse of said sensing means train of pulses for a time interval equal to the time interval between successive pulses of said sensing means train of pulses when the actual speed of said rotatable member is equal to said desired rotational speed.
Claim 5
Dependent Claim
46 words
A system of claim 1 wherein said comparing means provides a train of pulses with each of said pulses of said comparing means train of pulses being representative of the time interval between the receipt of the pulses of one of said respective pairs of pulses.
Claim 6
Dependent Claim
43 words
A system of claim 4 wherein each of said pulses of said comparing means train of pulses has a particular characteristic representative of that pulse of said pulses of said one respective pair of pulses which is first received by said comparing means.
Claim 7
Dependent Claim
40 words
A system according to claim 4 wherein each pulse of said comparing means train of pulses has a duration representative of the time interval between receipt by said comparing means of said pulses of said one respective pair of pulses.
Claim 8
Dependent Claim
91 words
A system according to claim 6 wherein each pulse of said comparing means train of pulses has either one polarity representing that said pulse of said delay means train of pulses of said respective pair is received by said comparing means prior to said pulse of said sensing means train of pulses of said respective pair or an opposite polarity representing that said pulse of said delay means train of pulses of said respective pair is received after said pulse of said sensing means train of pulses of said respective pair.
Claim 9
Dependent Claim
47 words
A system according to claim 7 further including integrating means receiving said comparing means output pulses for providing a signal representative of the sum of said comparing means output pulses of said one polarity minus the sum of said comparing means output pulses of said opposite polarity.
Claim 10
Dependent Claim
15 words
A system according to claim 1 wherein said delay means is a digital delay means.
Claim 11
Dependent Claim
58 words
A system according to claim 9 wherein said digital delay means is a shift register having a predetermined number of stages which is adapted for moving said correlative pulse through each of said stages at a predetermined rate whereby said correlative pulse is transferred throUgh said shift register in said predetermined time period to provide said delayed pulse.
Claim 12
Independent Claim
393 words
A system for adjusting the rotational speed of a rotatable member to approach a desired rotational speed comprising: sensing means associated with said member for providing a sensing means train of pulses, each pulse of said sensing means train of pulses being representative of a predetermined increment of rotation of said member; digital delay means receiving said sensing means train of pulses for providng a delay means train of output pulses, each pulse of said delay means train of pulses being correlative to one pulse received from said sensing means and being delayed relative to said correlative pulse for a predetermined period representative of said desired rotational speed of said rotatable member, said digital delay means including a shift register having a predetermined number of stages which is adapted for moving said correlative pulse through each of said stages at a predetermined rate whereby said correlative pulse is transferred through said shift register in said predetermined time period to provide said delayed pulse; clock pulse generating means operatively associated with said shift register for providng clock pulses to said shift register, said shift register being adapted so that each clock pulse causes said correlative pulse to transfer one stage of said shift register whereby a predetermined number of clock pulses equal to said predetermined number of stages provides said transfer of said correlative through said shift register wherein said rate of generation of said clock pulses establishes said predetermined time period comparing means receiving said sensing means train of pulses and said digital delay means train of pulses for providing an output signal representative of the time interval between the receipt of respective pairs of said pulses of said delay means train of pulses and said sensing means train of pulses, each of said respective pairs of said pulses of said delay means train of pulses and said sensing means train of pulses including a pulse of said delay means train of pulses and a pulse of said sensing means train of pulses which is subsequent to said correlative pulse; and speed control means associated with said rotatable member for receiving said output signal of said comparing means and for controlling the rotational speed of said rotatable member in accordance with said output signal of said comparing means to cause the rotational speed of said rotatable member to approach said desired rotational speed.
Claim 13
Independent Claim
393 words
A system for adjusting the rotational speed of a rotatable member to approach a desired rotational speed comprising: sensing means associated with said member for providing a sensing means train of pulses, each pulse of said sensing means train of pulses being representative of a predetermined increment of rotation of said member; digital delay means receiving said sensing means train of pulses for providng a delay means train of output pulses, each pulse of said delay means train of pulses being correlative to one pulse received from said sensing means and being delayed relative to said correlative pulse for a predetermined period representative of said desired rotational speed of said rotatable member, said digital delay means including a shift register having a predetermined number of stages which is adapted for moving said correlative pulse through each of said stages at a predetermined rate whereby said correlative pulse is transferred through said shift register in said predetermined time period to provide said delayed pulse; clock pulse generating means operatively associated with said shift register for providng clock pulses to said shift register, said shift register being adapted so that each clock pulse causes said correlative pulse to transfer one stage of said shift register whereby a predetermined number of clock pulses equal to said predetermined number of stages provides said transfer of said correlative through said shift register wherein said rate of generation of said clock pulses establishes said predetermined time period comparing means receiving said sensing means train of pulses and said digital delay means train of pulses for providing an output signal representative of the time interval between the receipt of respective pairs of said pulses of said delay means train of pulses and said sensing means train of pulses, each of said respective pairs of said pulses of said delay means train of pulses and said sensing means train of pulses including a pulse of said delay means train of pulses and a pulse of said sensing means train of pulses which is subsequent to said correlative pulse; and speed control means associated with said rotatable member for receiving said output signal of said comparing means and for controlling the rotational speed of said rotatable member in accordance with said output signal of said comparing means to cause the rotational speed of said rotatable member to approach said desired rotational speed.
Claim 14
Dependent Claim
29 words
A system according to claim 11 wherein the rate of generation of said clock pulses by said clock pulse generating means is controlled in accordance with said desired speed.
Claim 15
Dependent Claim
36 words
A system according to claim 12 wherein said clock pulse generating means is a voltage controlled oscillator including a terminal adapted to receive a control voltage which establishes the rate of generation of said clock pulses.
Claim 16
Dependent Claim
37 words
A system according to claim 13 further including means for providing a signal of adjustable voltage to said voltage controlled oscillator to adjust the rate of generation of said clock pulses by said clock pulse generating means.
Claim 17
Dependent Claim
64 words
A system according to claim 14 wherein said means for providing a signal of adjustable voltage provides a signal of increasing voltage for providing a predetermined increase in the rate of generation of said clock pulses and a corresponding increase in said desired speed whereby said rotational speed of said rotatable member will increase in accordance with said increase in said desired rotational speed.
Claim 18
Dependent Claim
64 words
A system according to claim 14 wherein said means for providing a signal of adjustable voltage provides a signal of decreasing voltage for providng a predetermined decrease in the rate of generation of said clock pulses and a corresponding decrease in said desired speed whereby said rotational speed of said rotatable member will decrease in accordanCe with said decrease in said desired rotational speed.
Claim 19
Dependent Claim
65 words
A system according to claim 15 wherein said means for providing a signal of adjustable voltage also provides a signal of decreasing voltage for providing a predetermined decrease in the rate of generation of said clock pulses and a corresponding decrease in said desired speed whereby said rotational speed of said rotatable member will decrease in accordance with said decrease in said desired rotational speed.
Claim 20
Independent Claim
208 words
A system for adjusting the rotational speed of an output shaft of a viscous shear variable speed drive comprising: sensing means associated with said output shaft for providing a sensing means train of pulses, each pulse of said sensing means train of pulses being representative of a predetermined increment of rotation of said output shaft; speed reference means for providng a speed reference signal representative of the desired rotational speed of said output shaft; delay means operatively coupled both with said sensing means and with said speed reference means for receiving as respective inputs thereto said sensing means train of pulses and said speed reference signal, said delay means comprising means for causing each pulse of said sensing means train of pulses to be delayed for a delay period whose duration is inversely proportional to the desired rotational speed of said shaft over a range of desired rotational speeds; comparing means receiving said sensing means train of pulses and the output of said delay means to thereby compare the time interval between sequential ones of said sensing means train of pulses and the time delay imposed by said delay means on the earlier of said sequential pulses and for providing a control signal representative of said comparison; and
Claim 21
Independent Claim
208 words
A system for adjusting the rotational speed of an output shaft of a viscous shear variable speed drive comprising: sensing means associated with said output shaft for providing a sensing means train of pulses, each pulse of said sensing means train of pulses being representative of a predetermined increment of rotation of said output shaft; speed reference means for providng a speed reference signal representative of the desired rotational speed of said output shaft; delay means operatively coupled both with said sensing means and with said speed reference means for receiving as respective inputs thereto said sensing means train of pulses and said speed reference signal, said delay means comprising means for causing each pulse of said sensing means train of pulses to be delayed for a delay period whose duration is inversely proportional to the desired rotational speed of said shaft over a range of desired rotational speeds; comparing means receiving said sensing means train of pulses and the output of said delay means to thereby compare the time interval between sequential ones of said sensing means train of pulses and the time delay imposed by said delay means on the earlier of said sequential pulses and for providing a control signal representative of said comparison; and
Claim 22
Dependent Claim
47 words
A system according to claim 18 wherein said comparing means control signal is representative of whether said time interval between sequential ones of said sensing means train of pulses is greater or less than said time interval representative of the desired rotational speed of said output shaft.
Claim 23
Dependent Claim
58 words
The system as recited in claim 18 wherein said system further comprises a source of pressurized fluid acting on one side of a piston means to adjust the rotational speed of said output shaft, and wherein said receiving means includes valve means for adjustably regulating the pressure acting on said piston means in response to said control signal.
Claim 24
Dependent Claim
47 words
The system as recited in claim 20 wherein said valve means includes a passage having an inlet in fluid communication with said source, a flapper disposed in said passage and defining a variable restriction therewith, and solenoid means responsive to said control signal for modulating said flapper.
Claim 25
Dependent Claim
31 words
The system as recited in claim 21 wherein said valve passage has an outlet in fluid communication with said viscous shear drive to discharge fluid thereon thereby to maintain viscous shear.
Claim 26
Independent Claim
446 words
A system for adjusting the rotational speed of a rotatable member to approach a desired rotational speed comprising: sensing means associated with said member for providing a sensing means train of pulses, each pulse of said sensing means train of pulses being representative of a predetermined increment of rotation of said member; delay means receiving said sensing means train of pulses for providing a delay means train of output pulses, each pulse of said delay means train of pulses being correlative to one pulse received from said sensing means and being delayed relative to said correlative pulse for a predetermined period representative of said desired rotational speed of said rotatable member; comparing means receiving said sensing means train of pulses and said delay means train of pulses for providing an output signal representative of the time interval between the receipt of respective pairs of said pulses of said delay means train of pulses and said sensing means train of pulses, each of said respective pairs of said pulses of said delAy means train of pulses and said sensing means train of pulses including a pulse of said delay means train of pulses and a pulse of said sensing means train of pulses which is subsequent to said correlative pulse, said output signal comprising a train of pulses with each of said pulses of said comparing means train of pulses being representative of the time interval between the receipt of the pulses of one of said respective pairs of pulses and having a duration representative of the time interval between receipt of said pulses of said one respective pair of pulses, each pulse of said comparing means train of pulses having either one polarity representing that said pulse of said delay means train of pulses of said respective pair being received by said comparing means prior to said pulse of said sensing means train of pulses of said respective pair, or an opposite polarity representing that said pulse of said delay means train of pulses of said respective pair being received after said pulse of said sensing means train of pulses of said respective pair; integrating means receiving said comparing means output pulses for providing a signal representative of the sum of said comparing means output pulses of said one polarity minus the sum of said comparing means output pulses of said opposite polarity; and speed control means associated with said rotatable member for receiving said output signal of said comparing means and for controlling the rotational speed of said rotatable member in accordance with said output signal of said comparing means to cause the rotational speed of said rotatable member to approach said desired rotational speed.
Claim 27
Independent Claim
446 words
A system for adjusting the rotational speed of a rotatable member to approach a desired rotational speed comprising: sensing means associated with said member for providing a sensing means train of pulses, each pulse of said sensing means train of pulses being representative of a predetermined increment of rotation of said member; delay means receiving said sensing means train of pulses for providing a delay means train of output pulses, each pulse of said delay means train of pulses being correlative to one pulse received from said sensing means and being delayed relative to said correlative pulse for a predetermined period representative of said desired rotational speed of said rotatable member; comparing means receiving said sensing means train of pulses and said delay means train of pulses for providing an output signal representative of the time interval between the receipt of respective pairs of said pulses of said delay means train of pulses and said sensing means train of pulses, each of said respective pairs of said pulses of said delAy means train of pulses and said sensing means train of pulses including a pulse of said delay means train of pulses and a pulse of said sensing means train of pulses which is subsequent to said correlative pulse, said output signal comprising a train of pulses with each of said pulses of said comparing means train of pulses being representative of the time interval between the receipt of the pulses of one of said respective pairs of pulses and having a duration representative of the time interval between receipt of said pulses of said one respective pair of pulses, each pulse of said comparing means train of pulses having either one polarity representing that said pulse of said delay means train of pulses of said respective pair being received by said comparing means prior to said pulse of said sensing means train of pulses of said respective pair, or an opposite polarity representing that said pulse of said delay means train of pulses of said respective pair being received after said pulse of said sensing means train of pulses of said respective pair; integrating means receiving said comparing means output pulses for providing a signal representative of the sum of said comparing means output pulses of said one polarity minus the sum of said comparing means output pulses of said opposite polarity; and speed control means associated with said rotatable member for receiving said output signal of said comparing means and for controlling the rotational speed of said rotatable member in accordance with said output signal of said comparing means to cause the rotational speed of said rotatable member to approach said desired rotational speed.
Claim 28
Dependent Claim
119 words
A servo valve for use in a system for adjusting the rotational speed of an output shaft of a variable speed drive having an actuating piston for controlling the clamping pressure applied to a disc stack located in a fluid reservoir and including a source of pressurized liquid acting on said piston, the valve comprising: a housing including first passage means for fluidly communicating said piston and second passage means for fluidly communicating said first passage means and said reservoir; relief means located in said second passage means for selectively controlling the magnitude of pressure in said first passage means; and control means for varying said relief means in accordance with a desired output speed for said output shaft.
Claim 29
Dependent Claim
119 words
A servo valve for use in a system for adjusting the rotational speed of an output shaft of a variable speed drive having an actuating piston for controlling the clamping pressure applied to a disc stack located in a fluid reservoir and including a source of pressurized liquid acting on said piston, the valve comprising: a housing including first passage means for fluidly communicating said piston and second passage means for fluidly communicating said first passage means and said reservoir; relief means located in said second passage means for selectively controlling the magnitude of pressure in said first passage means; and control means for varying said relief means in accordance with a desired output speed for said output shaft.
Claim 30
Dependent Claim
23 words
A servo valve as claimed in claim 24 wherein said relief means includes a flapper plate means disposed within said second passage means.
Claim 31
Dependent Claim
20 words
A servo valve as claimed in claim 25 wherein said flapper plate means includes means defining a bleed passage therethrough.
Claim 32
Dependent Claim
32 words
A servo valve as claimed in claim 25 including spring means disposed in said second passage means for biasing said flapper plate means in a direction away from said first passage means.
Claim 33
Dependent Claim
36 words
A valve as claimed in claim 25 wherein said control means includes a solenoid means disposed on said housing for actuating said flapper plate means in accordance with the desired output speed for said output shaft.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |