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US4775195A Expired / Lapsed US ⏱️ 0.0 years remaining

Hydraulic systems

Assignee: Dunlop Ltd
•
Filing: 1987-10-13
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Granted: 1988-10-04
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Expires: 2007-10-13
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Abstract

Abstract A system for guarding against the leakage of fluid from a hydraulic system, particularly an aircraft braking system, which employs a flow control valve under the control of an electronic processor. The electronic processor integrates with respect to time a function of the input signal to the flow control valve and the pressure of the output of fluid, compares the value of the integrated function with a predetermined value, and effects closure of the control valve if the comparison indicates a substantial fluid loss.

Inventors

  • 👤 Richard J. Miller

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 12:12
CPC Classifications
B; B64; B64C; B64C25/00; B64C25/32; B64C25/42; Y; Y10; Y10S; Y10S303/00; Y10S303/02; Y10S303/03; Y10S303/04; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7759; Y10T137/776

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 137 words
A hydraulic system comprising a flow control valve of the kind in which an effective orifice is presented as a known function of an input signal, an electronic processor arranged to provide an input signal in response to a demand signal to effect control of the flow control valve, an electrical pressure transducer arranged to sense the pressure of the input of fluid from the flow control valve and to provide an input to the processor, said proessor including means for integrating with respect to time a function of the input signal to the flow control valve and the pressure of the output of fluid and to effect comparison of the value of said integrated function with a predetermined value and to effect closure of the flow control valve if said comparison indicates a substantial fluid loss.
Claim 2
Dependent Claim 137 words
A hydraulic system comprising a flow control valve of the kind in which an effective orifice is presented as a known function of an input signal, an electronic processor arranged to provide an input signal in response to a demand signal to effect control of the flow control valve, an electrical pressure transducer arranged to sense the pressure of the input of fluid from the flow control valve and to provide an input to the processor, said proessor including means for integrating with respect to time a function of the input signal to the flow control valve and the pressure of the output of fluid and to effect comparison of the value of said integrated function with a predetermined value and to effect closure of the flow control valve if said comparison indicates a substantial fluid loss.
Claim 3
Dependent Claim 19 words
A hydraulic system according to claim 1 wherein the effective orifice has a linear relationship with the input signal.
Claim 4
Dependent Claim 8 words
A hydraulic braking system according to claim 1.
Claim 5
Dependent Claim 17 words
A hydraulic braking system according to claim 1 wherein an anti-skid signal is provided to the processor.

References Cited (Backward Citations)

US3509528A Cited
US3671082A Cited
US4061155A Cited
US4502501A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-10-04 1992-04-04 1992-10-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-10-04 1996-04-04 1996-10-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-10-04 2000-04-04 2000-10-04 $7700.00 Window Closed / Lapsed

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