US3787027A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power transmission
Assignee: Vickers Inc
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Filing: 1972-10-16
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Granted: 1974-01-22
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Expires: 1992-10-16
Abstract
Abstract A valve for automatic stabilization of hydraulic motor speed under varying motor loads is arranged to bypass a small flow around the principal motor speed regulating valve, which small flow is increased with the motor inlet pressure. This compensates for the cross-port leakage in the motor which varies with motor load. The inner parts of the valve may be selectively assembled in various positions to provide various maximum flow openings so that hydraulic motors of various sizes may be effectively stabilized.
Inventors
- 👤 J Curnow
- 👤 H Nowicki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:03
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/0416; F15B13/0417; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/4043; F16H59/00; F16H59/68; F16H2059/6838; F16H2059/6861; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7762; Y10T137/7769; Y10T137/777; Y10T137/7781
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
170 words
A valve for automatic stabilization of hydraulic motor speed under varying load conditions comprising a body having a longitudinal bore closed at opposite ends, first and second lateral ports opening to the bore at longitudinally spaced locations, the first port communicating with the bore through slots of limited circumferential width, a spool slidable in the bore having a land to normally close communication between the ports, tapered grooves in the land adapted to register with the slots in the bore when the spool is shifted longitudinally to establish communication between the ports, piston means at one end of the bore for shifting the spool, spring means at the opposite end of the bore to bias the spool toward closed position, means forming a sliding key and keyway between the spool and the bore to maintain rotational register between the slots and the grooves, and means for establishing a plurality of positions of register to provide a plurality of maximum flow rates when the spool is fully shifted to open position.
Claim 2
Dependent Claim
170 words
A valve for automatic stabilization of hydraulic motor speed under varying load conditions comprising a body having a longitudinal bore closed at opposite ends, first and second lateral ports opening to the bore at longitudinally spaced locations, the first port communicating with the bore through slots of limited circumferential width, a spool slidable in the bore having a land to normally close communication between the ports, tapered grooves in the land adapted to register with the slots in the bore when the spool is shifted longitudinally to establish communication between the ports, piston means at one end of the bore for shifting the spool, spring means at the opposite end of the bore to bias the spool toward closed position, means forming a sliding key and keyway between the spool and the bore to maintain rotational register between the slots and the grooves, and means for establishing a plurality of positions of register to provide a plurality of maximum flow rates when the spool is fully shifted to open position.
Claim 3
Dependent Claim
27 words
A valve as defined in claim 1 wherein the bore is formed by a sleeve in the body, the sleeve having longitudinal slots adjacent the first port.
Claim 4
Dependent Claim
29 words
A valve as defined in claim 2 wherein a locating member has a sliding keyed relation with the spool and a plurality of selective keyed relations with the body.
Claim 5
Dependent Claim
27 words
A valve as defined in claim 3 wherein the locating member is a ring positioned between the body and an end cap removably attached to the body.
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |