US3559534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic actuator control circuit
Assignee: Pines Engineering Co Inc
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Filing: 1968-04-23
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Granted: 1971-02-02
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Expires: 1988-04-23
Abstract
Abstract A hydraulic servo drive system with a regulator valve connected in series with a servovalve, and which maintains a constant pressure drop across the servovalve and a uniform drive velocity in the system.
Inventors
- 👤 Harrison Munro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:51
CPC Classifications
F; F15; F15B; F15B11/00; F15B11/02; F15B11/04; F15B11/05; F15B11/055; F15B2211/00; F15B2211/30; F15B2211/305; F15B2211/30525; F15B2211/3053; F15B2211/30535; F15B2211/32; F15B2211/327; F15B2211/35; F15B2211/50; F15B2211/505; F15B2211/50563; F15B2211/50581; F15B2211/5059; F15B2211/515; F15B2211/5153; F15B2211/52; F15B2211/528; F15B2211/60; F15B2211/63; F15B2211/6303; F15B2211/6336; F15B2211/665; F15B2211/70; F15B2211/75; F15B2211/765
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
91 words
A hydraulic drive system comprising: a hydraulic motor; a source of hydraulic fluid under pressure; a variably positionable servovalve connected between said source and said motor; and a regulator valve in series with the said servovalve, means to maintain a constant pressure drop across the servovalve, said servovalve being responsive to control information to establish a flow orifice which is a function of a desired motor speed, said servovalve being electrically operated and including a source of control current input thereto, said current being a function of a desired motor speed.
Claim 2
Dependent Claim
91 words
A hydraulic drive system comprising: a hydraulic motor; a source of hydraulic fluid under pressure; a variably positionable servovalve connected between said source and said motor; and a regulator valve in series with the said servovalve, means to maintain a constant pressure drop across the servovalve, said servovalve being responsive to control information to establish a flow orifice which is a function of a desired motor speed, said servovalve being electrically operated and including a source of control current input thereto, said current being a function of a desired motor speed.
Claim 3
Dependent Claim
110 words
A hydraulic drive system comprising: a hydraulic motor; a source of hydraulic fluid under pressure; a variably positionable servovalve connected between said source and said motor; and a regulator valve in series with the said servovalve, means to maintain a constant pressure drop across the servovalve, a source of speed and position command information, and a motor position feedback transducer and a control responsive to the command information and the feedback transducer, said control generating a constant control signal establishing a fixed flow control orifice in the servovalve, said regulator valve responding to changes in pressure drop across the servovalve to maintain the desired hydraulic fluid flow to the motor.
Claim 4
Dependent Claim
110 words
A hydraulic drive system comprising: a hydraulic motor; a source of hydraulic fluid under pressure; a variably positionable servovalve connected between said source and said motor; and a regulator valve in series with the said servovalve, means to maintain a constant pressure drop across the servovalve, a source of speed and position command information, and a motor position feedback transducer and a control responsive to the command information and the feedback transducer, said control generating a constant control signal establishing a fixed flow control orifice in the servovalve, said regulator valve responding to changes in pressure drop across the servovalve to maintain the desired hydraulic fluid flow to the motor.
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) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |