Patent US3817153A successfully refreshed from Google Patents.
US3817153A
Expired / Lapsed
US
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Hydraulic control circuit
Assignee: Bosch Rexroth AG
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Filing: 1972-09-27
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Granted: 1974-06-18
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Expires: 1992-09-27
Abstract
Abstract A plurality of valve units, each including a plurality of main valves connected in series in an idling conduit connecting the outlet of a control pump with a discharge space, is used for supplying hydraulic consumer motors with pressure fluid. Each main valve has an idling position for connecting the outlet of the pump with the discharge space through the idling conduit, and two operative positions for supplying and discharging fluid from the respective consumer motor, and for closing the idling circuit. Each main valve includes hydraulic operating means for shifting the main valve between idling and operative positions. A plurality of control valves supplies fluids to and discharge fluids from the hydraulic operating means, and a pressure control unit connects the idling conduit with the control valves. the pressure control unit includes a pressure reducing valve, a pressure fluid accumulator, a check valve between the accumulator and the pressure reducing valve so that a selected pressure is maintained in the hydraulic operating means when the respective main valve is in one of the operating positions. Preferably, a pressure limiting valve is arranged downstream of the pressure reducing valve, and has a higher pressure than the same. A pressurizing valve is provided between the idling conduit and the discharge space for maintaining a pressure in the idling conduit by which the operation of the operating means is started.
Inventors
- 👤 E Zunzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:26
CPC Classifications
F; F15; F15B; F15B11/00; F15B11/16; F15B11/17; F15B1/00; F15B1/02; F15B1/027; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/2053; F15B2211/20546; F15B2211/20553; F15B2211/20576; F15B2211/25; F15B2211/30; F15B2211/31; F15B2211/3105; F15B2211/3116; F15B2211/32; F15B2211/329; F15B2211/60; F15B2211/635; F15B2211/6355; F15B2211/67; F15B2211/70; F15B2211/71; F15B2211/7142
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
231 words
Hydraulic control circuit, comprising a control pump having an outlet for pressure fluid; a discharge space; idling conduit means between said outlet of said pump and said discharge space; at least one valve unit including a plurality of main valve means connected in series in said idling conduit, and being respectively associated with hydraulic consumer motors, each main valve means having an idling position for connecting said outlet of said pump with said discharge space through said idling conduit, and at least one operative position for supplying fluid to, and discharging fluid from the respective consumer motor, and for closing said idling conduit, each main valve means including hydraulic operating means for shifting said main valve means between said idling and operative positions; a plurality of control valve means for supplying fluid to, and for discharging fluid from said hydraulic operating means, respectively; and a pressure control unit connecting said outlet of said pump and idling circuit with said control valve means so that in said idling position the initial pressure in said idling conduit starts said operating means, said pressure control unit including pressure reducing valve means, a pressure fluid accumulator, and a check valve between said accumulator and said pressure reducing valve means opening toward the former so that a selected pressure is maintained in said hydraulic operating means when said main valve means is in said operative position.
Claim 2
Dependent Claim
231 words
Hydraulic control circuit, comprising a control pump having an outlet for pressure fluid; a discharge space; idling conduit means between said outlet of said pump and said discharge space; at least one valve unit including a plurality of main valve means connected in series in said idling conduit, and being respectively associated with hydraulic consumer motors, each main valve means having an idling position for connecting said outlet of said pump with said discharge space through said idling conduit, and at least one operative position for supplying fluid to, and discharging fluid from the respective consumer motor, and for closing said idling conduit, each main valve means including hydraulic operating means for shifting said main valve means between said idling and operative positions; a plurality of control valve means for supplying fluid to, and for discharging fluid from said hydraulic operating means, respectively; and a pressure control unit connecting said outlet of said pump and idling circuit with said control valve means so that in said idling position the initial pressure in said idling conduit starts said operating means, said pressure control unit including pressure reducing valve means, a pressure fluid accumulator, and a check valve between said accumulator and said pressure reducing valve means opening toward the former so that a selected pressure is maintained in said hydraulic operating means when said main valve means is in said operative position.
Claim 3
Dependent Claim
37 words
Hydraulic control circuit as claimed in claim 1 comprising pressurizing valve means between said idling conduit and said discharge space for maintaining a pressure in said idling conduit in said idling position of said control valve means.
Claim 4
Dependent Claim
22 words
Hydraulic control circuit as claimed in claim 2 wherein said pressurizing valve means includes a check valve opening towards said discharge space.
Claim 5
Dependent Claim
39 words
Hydraulic control circuit as claimed in claim 1 wherein said pressure control unit incLudes a pressure limiting valve downstream of said pressure reducing valve, said pressure limiting valve being set to a higher pressure than said pressure reducing valve.
Claim 6
Dependent Claim
54 words
Hydraulic control circuit as claimed in claim 1 comprising two control pumps; two idling conduits; two valve units; and wherein said pressure control unit includes a shiftable double check valve having two inlets connected near outlets of said pumps with said idling conduits, respectively, and one outlet connected with said pressure reducing valve means.
Claim 7
Dependent Claim
83 words
Hydraulic control circuit as claimed in claim 5 wherein said pressure control unit includes a pressure limiting valve downstream of said pressure reducing valve, said pressure limiting valve being set to a higher pressure than said pressure reducing valve means; and wherein said pressure control unit includes a valve block formed with bores in which said pressure reducing valve means, said pressure limiting valve means, and said double check valve are located, and having a threaded bore into which said accumulator is threaded.
Claim 8
Dependent Claim
31 words
Hydraulic control circuit as claimed in claim 5 wherein said two control pumps include adjusting means for adjusting said control pumps to discharge fluid at different pressures at said outlets, respectively.
Claim 9
Dependent Claim
33 words
Hydraulic control circuit as claimed in claim 1 wherein each main valve means has two operative positions and said idling position; and wherein said consumer motors are reversed in said two operative positions.
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) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |