US3924655A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic control arrangement
Assignee: Robert Bosch GmbH
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Filing: 1974-01-17
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Granted: 1975-12-09
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Expires: 1994-01-17
Abstract
Abstract A hydraulic control arrangement provided with a control valve having a spool movable between a neutral position which closes at least one conduit leading to a consumer device and two working positions, in one of which it connects the conduit with a fluid inlet passage and in the other of which it connects the conduit with a fluid return passage. The hydraulic control arrangement includes a switch valve communicating with the fluid inlet and the fluid outlet of the arrangement and having a valve member biased by a spring to a position in which flow of fluid from the inlet to the outlet through the switch valve is prevented. The position of the valve member is further controlled by a pair of throttles arranged in a control conduit communicating with the switch valve and arranged and constructed in such a manner that undesirable pressure increases during fine regulation of fluid flow passing through the control valve to the consumer device are prevented.
Inventors
- 👤 Gunther Schwerin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:20
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/0416; F15B13/0417; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/8667; Y10T137/86694; Y10T137/8671; Y10T137/87169; Y10T137/87177; Y10T137/87185
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
298 words
A hydraulic control arrangement comprising a fluid inlet and a fluid outlet; switch valve means communicating with said inlet and said outlet and having a valve member movable between an open position permitting flow of fluid from said inlet to said outlet through said switch valve means and a closed position preventing such flow, and spring means biasing said valve member to said closed position; first control passage means providing constant communication between said inlet and said switch valve means and connected in parallel to the latter so that fluid passing through said first control passage means acts on said valve member in the same direction as said spring means; second control passage means communicating at one end with said first control passage means; a first throtTle in said first control passage means upstream of said one end of said second control passage means; a second throttle arranged in said first control passage means upstream of said first throttle and having an open crosssection which remains constant during operation; return flow passage means communicating at one end with said outlet and adapted to communicate at the other end with the other end of said second control passage means; inlet passage means communicating at one end with said first control passage means between said first and said second throttle therein; and control valve means having a control member movable between a neutral position in which it closes at least one conduit leading to a consumer device and working positions at opposite sides of said neutral position for selectively connecting said conduit with said inlet passage means and said return flow passage means, said control member regulating also flow from said second control passage means to said return flow passage means and from said inlet passage means to said conduit.
Claim 2
Dependent Claim
298 words
A hydraulic control arrangement comprising a fluid inlet and a fluid outlet; switch valve means communicating with said inlet and said outlet and having a valve member movable between an open position permitting flow of fluid from said inlet to said outlet through said switch valve means and a closed position preventing such flow, and spring means biasing said valve member to said closed position; first control passage means providing constant communication between said inlet and said switch valve means and connected in parallel to the latter so that fluid passing through said first control passage means acts on said valve member in the same direction as said spring means; second control passage means communicating at one end with said first control passage means; a first throtTle in said first control passage means upstream of said one end of said second control passage means; a second throttle arranged in said first control passage means upstream of said first throttle and having an open crosssection which remains constant during operation; return flow passage means communicating at one end with said outlet and adapted to communicate at the other end with the other end of said second control passage means; inlet passage means communicating at one end with said first control passage means between said first and said second throttle therein; and control valve means having a control member movable between a neutral position in which it closes at least one conduit leading to a consumer device and working positions at opposite sides of said neutral position for selectively connecting said conduit with said inlet passage means and said return flow passage means, said control member regulating also flow from said second control passage means to said return flow passage means and from said inlet passage means to said conduit.
Claim 3
Dependent Claim
44 words
A hydraulic control arrangement as defined in claim 9, wherein said control member in said neutral position permits free flow of fluid from said second control passage means to said return flow passage means and in each of said working positions throttles such flow.
Claim 4
Dependent Claim
59 words
A hydraulic control arrangement as defined in claim 1, wherein said control member of said control valve means is in the form of an elongated spool movable in axial direction between said positions thereof, said spool having sections provided with cutouts of gradually varying cross section for fine regulating flow of fluid passing through said second control passage means.
Claim 5
Dependent Claim
37 words
A hydraulic control arrangement as defined in claim 3, wherein said spool has further sections provided with cutouts of gradually varying cross section for fine regulating flow of fluid from said inlet passage means to said conduit.
Claim 6
Dependent Claim
79 words
A hydraulic control arrangement as defined in claim 4, wherein the open cross section of said second throttle means is at least such that, when said second control passage means is closed by said spool while a maximum fluid flow passes from said inlet passage means to said conduit, the force resulting from the pressure drop at the second throttle and acting on said valve member of said switch valve is smaller than the force of said spring means.
Claim 7
Dependent Claim
78 words
A hydraulic control arrangement as defined in claim 4, wherein the open cross section of said second throttle is such that, when said second control passage means is closed by said spool while a maximum fluid flow passes from said inlet passage means to said conduit, the force resulting from the pressure drop at said second throttle and acting on said valve member of said switch valve is only slightly smaller than the force of said spring means.
Claim 8
Dependent Claim
26 words
A hydraulic control arrangement as defined in claim 1, wherein said second throttle has an open cross-section which is greater than that of the first throttle.
References Cited (Backward Citations)
US3722543A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |