US3864913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control apparatus for hydraulic-lift tail gates of vans, and the like
Assignee: Robert Bosch GmbH
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Filing: 1973-11-29
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Granted: 1975-02-11
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Expires: 1993-11-29
Abstract
Abstract The apparatus controls at least one double-acting consumer. A control valve includes at least one valve member movable between first operative, second operative and neutral positions to thereby respectively connect a first fluid-conveying line of the consumer with a supply conduit which is connected to a source of pressurized fluid, with a return conduit which is connected to a tank, and to seal the first line from the conduits. The valve member regulates the flow of fluid in a control conduit for a switch valve. The switch valve has a first port connected to the source of pressurized fluid, a second port connected to a second fluid-conveying line of the consumer, and a third port connected to the return conduit. The switch valve includes at least one valve member normally maintained in a first position establishing communication in the switch valve between the second and third ports thereof and blocking flow through the first port thereof. The valve member of the switch valve is movable under the influence of fluid flow in the control conduit to a second position establishing communication in the switch valve between the first and second ports thereof and blocking flow through the third port thereof.
Inventors
- 👤 Walter Herrmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:32
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/06; F15B11/00; F15B11/16; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/20507; F15B2211/20515; F15B2211/275; F15B2211/30; F15B2211/305; F15B2211/3056; F15B2211/30565; F15B2211/30585; F15B2211/31; F15B2211/3105; F15B2211/3111; F15B2211/32; F15B2211/329; F15B2211/60; F15B2211/63; F15B2211/6303; F15B2211/634; F15B2211/665; F15B2211/6651; F15B2211/70; F15B2211/71; F15B2211/7114; F15B2211/7128; Y; Y10; Y10S; Y10S60/00; Y10S60/911
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
204 words
In a hydraulic control apparatus for at least one doubleacting consumer wherein at least one control valve includes at least one valve member movable between first operative, second operative and neutral positions to thereby respectively connect a first fluid-conveying line oF said consumer with a supply conduit which is connected to a source of pressurized fluid, with a return conduit which is connected to a tank, and to seal said first line from said conduits, and wherein said valve member regulates the flow of fluid in a control conduit for a switch valve, the improvement which consists in said switch valve having a first port connected to said source of pressurized fluid, a second port connected to a second fluid-conveying line of said consumer, and a third port connected to said return conduit, and wherein said switch valve includes at least one valve member normally maintained in a first position establishing communication in said switch valve between said second and third ports and blocking flow through said first port and movable under the influence of fluid flow in said control conduit to a second position establishing communication in said switch valve between said first and second ports and blocking flow through said third port.
Claim 2
Dependent Claim
204 words
In a hydraulic control apparatus for at least one doubleacting consumer wherein at least one control valve includes at least one valve member movable between first operative, second operative and neutral positions to thereby respectively connect a first fluid-conveying line oF said consumer with a supply conduit which is connected to a source of pressurized fluid, with a return conduit which is connected to a tank, and to seal said first line from said conduits, and wherein said valve member regulates the flow of fluid in a control conduit for a switch valve, the improvement which consists in said switch valve having a first port connected to said source of pressurized fluid, a second port connected to a second fluid-conveying line of said consumer, and a third port connected to said return conduit, and wherein said switch valve includes at least one valve member normally maintained in a first position establishing communication in said switch valve between said second and third ports and blocking flow through said first port and movable under the influence of fluid flow in said control conduit to a second position establishing communication in said switch valve between said first and second ports and blocking flow through said third port.
Claim 3
Dependent Claim
53 words
An apparatus as defined in claim 1, and further including pressure-controlling means having a first port connected to said return conduit and to said third port of said switch valve and having a second port connected to said second fluid-conveying line of said consumer and to said second port of said switch valve.
Claim 4
Dependent Claim
28 words
An apparatus as defined in claim 2, wherein said pressure-controlling means comprises a flow restrictor having two ports constituting said first and second ports of said pressure-controlling means.
Claim 5
Dependent Claim
13 words
An apparatus as defined in claim 3, wherein said flow restrictor is adjustable.
Claim 6
Dependent Claim
28 words
An apparatus as defined in claim 2, wherein said pressure-controlling means comprises a pressure-limiting valve having two ports constituting said first and second ports of said pressure-controlling means.
Claim 7
Dependent Claim
23 words
An apparatus as defined in claim 1, and further including a pressure-limiting valve connected to said supply conduit for limiting the pressure therein.
Claim 8
Dependent Claim
125 words
An apparatus as defined in claim 1, wherein said switch valve is provided with biasing means for maintaining said at least one valve member of said switch valve in said first position thereof, and further including a flow restrictor in said control conduit for developing a pressure difference upstream and downstream of said flow restrictor in response to the establishment of flow through said control conduit, and connected to said control conduit upstream and downstream of said flow restrictor and operative in response to development of said pressure difference for applying to said at least one valve member of said switch valve a force opposing the force of said biasing means and moving said valve member of said switch valve to said second position thereof.
Claim 9
Dependent Claim
57 words
An apparatus as defined in claim 1, wherein said at least one valve member of said switch valve has an intermediate third position in which it establishes fluid communication in said switch valve between the first and third ports of the latter and in which it blocks fluid flow through said second port of said switch valve.
Claim 10
Dependent Claim
59 words
An apparatus as defined in claim 8, wherein said source of pressurized fluid includes a pump operative for pumping fluid into said supply line, and wherein said switch valve is further provided with activating means for initiating operation of said pump when said at least one valve member of said switch valve is moved into said second position thereof.
Claim 11
Dependent Claim
149 words
An apparatus as defined in claim 1, and further including an additional control valve in addition to said first-mentioned control valve, and an additional consumer in addition to said first-mentioned consumer, and wherein said additional control valve includes at least one valve member movable between first operative, second operative and neutral positions to thereby respectively connect a respective first fluid-conveying line of said additional consumer with said supply conduit, with said return conduit and to seal said respective first line of said additional consumer from said supply anD return conduits, and wherein said valve member of said additional control valve regulates the flow of fluid in said control conduit in cooperation with the regulation of fluid in said control conduit by said valve member of said first-mentioned control valve, and wherein said additional consumer has a respective second fluid-conveying line connected to said second port of said switch valve.
Claim 12
Dependent Claim
61 words
An apparatus as defined in claim 1, wherein said source of pressurized fluid includes a pump operative for pumping fluid into said supply line, and wherein said control valve is further provided with activating means for initiating operation of said pump in automatic response to movement of said valve member of said control valve into one of said operative positions thereof.
Claim 13
Dependent Claim
39 words
An apparatus as defined in claim 11, wherein said activating means comprises means operative for initiating operation of said pump in automatic response to movement of said valve member of said control valve into said first operative position thereof.
Claim 14
Dependent Claim
36 words
An apparatus as defined in claim 12, wherein said activating means comprises means operative for selectively initiating operation of said pump when said valve member of said control valve is in said second operative position thereof.
Claim 15
Dependent Claim
16 words
An apparatus as defined in claim 1, wherein said consumer is a hydraulic-lift tail gate arrangement.
Claim 16
Dependent Claim
16 words
An apparatus as defined in claim 1, wherein said control valve is of the seated-valve-member type.
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) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |