US3863446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid positioning apparatus
Assignee: Jordan Controls Inc
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Filing: 1973-07-16
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Granted: 1975-02-04
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Expires: 1993-07-16
Abstract
Abstract A hydraulic piston-cylinder operator is connected to the output of a positive displacement pump having an inlet connected to a reservoir and having a return conduit to the hydraulic reservoir having a pressure dropping element. The operator has a reset spring urging the unit to a first position. A variable speed direct current motor drives the pump and is controlled by a servo system with a command voltage signal and a feedback potentiometer voltage signal. An amplifier compares the signal and forms an error voltage which actuates the motor to control and hold the speed at that required to position the hydraulic operator against the spring to null the command signal.
Inventors
- 👤 Harry L Giwosky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:26
CPC Classifications
F; F15; F15B; F15B9/00; F15B9/02; F15B9/03
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
206 words
A positioning apparatus for accurately, mechanically positioning and holding a load in any one of a plurality of different load positions comprising a variable speed prime mover, a positive displacement pump coupled to and driven by said prime mover, a fluid responsive positioning device having a mechanical output for connection to a mechanical load and having a resilient return means, a fluid circuit means for connecting the positive displacement pump to the positioning device and a by-pass means including a restricted return means whereby the fluid pressure established is dependent on the speed of the prime mover to establish a position of the mechanical output against said resilient means, operating means connected to vary the speed of the prime mover and adjust the fluid pressure to said fluid responsive positioning device, and a servo control means connected to sense the position of the mechanical output and connected to control said operating means to said prime mover to adjust the speed of the prime mover in accordance with the sensed position and thereby the fluid pressure in said fluid responsive positioning device to variously position said mechanical output in any selected position between said limits and to hold said position with changes in the fluid circuit means.
Claim 2
Dependent Claim
206 words
A positioning apparatus for accurately, mechanically positioning and holding a load in any one of a plurality of different load positions comprising a variable speed prime mover, a positive displacement pump coupled to and driven by said prime mover, a fluid responsive positioning device having a mechanical output for connection to a mechanical load and having a resilient return means, a fluid circuit means for connecting the positive displacement pump to the positioning device and a by-pass means including a restricted return means whereby the fluid pressure established is dependent on the speed of the prime mover to establish a position of the mechanical output against said resilient means, operating means connected to vary the speed of the prime mover and adjust the fluid pressure to said fluid responsive positioning device, and a servo control means connected to sense the position of the mechanical output and connected to control said operating means to said prime mover to adjust the speed of the prime mover in accordance with the sensed position and thereby the fluid pressure in said fluid responsive positioning device to variously position said mechanical output in any selected position between said limits and to hold said position with changes in the fluid circuit means.
Claim 3
Dependent Claim
32 words
The positioning apparatus of claim 1 wherein said restricted return means is a conduit means connected to the output of the pump and to the positioning device and includes a fixed orifice.
Claim 4
Dependent Claim
86 words
The positioning apparatus of claim 1 wherein said prime mover is a variable speed D.C. motor, said fluid responsive positioning device is a piston-cylinder unit having a resilient reset means, said fluid circuit means connects the output of said positive displacement pump to said cylinder unit to oppose said reset means, said by-pass means is a return conduit having a fixed orifice whereby the fluid pressure established is dependent on the speed of the D.C. motor and a servo control means connected to control said motor.
Claim 5
Dependent Claim
14 words
The positioning apparatus of claim 3 wherein said fluid pressure is a hydraulic medium.
Claim 6
Dependent Claim
128 words
The positioning apparatus of claim 4 wherein said prime mover is a variable speed motor, said fluid responsive positioning device is a spring returned piston-cylinder unit having an output rod and a reset spring, said positive displacement pump having a hydraulic output connected directly to said piston-cylinder unit and to said restricted return means, said return means including a fixed orifice, said servo control means including a means to sense the position of said output rod and establishing a proportional signal voltage, means to establish a command voltage corresponding to a desired setting of said rod, and means to compare said voltages and vary the speed of the motor to establish and maintain a selected fluid pressure to correspondingly set and hold the rod in the desired position.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |