US3851566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling a hydraulic-lift tail gate arrangement of a cargo-carrying vehicle
Assignee: Robert Bosch GmbH
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Filing: 1973-12-12
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Granted: 1974-12-03
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Expires: 1993-12-12
Abstract
Abstract The apparatus comprises a double-acting consumer having a first work conduit for receipt of pressure fluid to cause the consumer to effect movement of a load in a first direction and having a second work conduit for receipt of pressure fluid to cause the consumer to effect movement of the load in opposite second direction. The apparatus includes a tank, a supply conduit and a pump for pumping fluid from the tank into the supply conduit, a second port connected to the tank, a third port, and a fourth port connected to the second work conduit of the double-acting consumer. The selector valve has a first position in which fluid communication is established in the selector valve between the first and fourth ports and also between the second and third ports. The selector valve has a second position in which fluid communication is established in the selector valve between the first and third ports and also between the second and fourth ports. A control valve has a first port connected to the first work conduit of the double-acting consumer and has a second port connected to the third port of the selector valve. The control valve has a first position in which fluid communication between the ports of the control valve in the control valve is blocked. The control valve has a second position in which fluid communication between the ports of the control valve in the control valve is established. A pressure-regulating device is connected between the fourth port of the selector valve and the tank and is operative for regulating the pressure of fluid in the second work conduit of the double-acting consumer.
Inventors
- 👤 W Herrmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:14
CPC Classifications
F; F15; F15B; F15B11/00; F15B11/16; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/2053; F15B2211/20538; F15B2211/30; F15B2211/305; F15B2211/30505; F15B2211/30515; F15B2211/3056; F15B2211/3059; F15B2211/32; F15B2211/327; F15B2211/40; F15B2211/405; F15B2211/40515; F15B2211/415; F15B2211/41581; F15B2211/46; F15B2211/50; F15B2211/505; F15B2211/50509; F15B2211/50518; F15B2211/55; F15B2211/70; F15B2211/71; F15B2211/7114; F15B2211/7128; F15B2211/75
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
275 words
A hydraulic control apparatus comprising, in combination, a double-acting consumer having a first work conduit for receipt of pressure fluid to cause said consumer to effect movement of a load in a first direction and having a second work conduit for receipt of pressure fluid to cause said consumer to effect movement of such load in opposite second direction; a tank; a supply conduit and a pump for pumping fluid from said tank into said supply conduit; a preselector valve having a first port connected to said supply conduit, a second port connected to said tank, a third port and a fourth port connected to said second work conduit of said double-acting consumer, said preselector valve having a first position in which fluid communication is established in said preselector valve between said first and fourth ports and also between said second and third ports and having a second position in which fluid communication is established in said preselector valve between said first and third ports and also between said second and fourth ports; a control valve having a first port connected to said first work conduit of said double-acting consumer and having a second port connected to said third port of said selector valve and having a first position in which fluid communication between said ports of said control valve in said control valve is blocked and having a second position in which fluid communication between said ports of said control valve in said control valve is established; and pressure-regulating means connected between said fourth port of said preselector valve and said tank and operative for regulating the fluid pressure in said second work conduit.
Claim 2
Dependent Claim
275 words
A hydraulic control apparatus comprising, in combination, a double-acting consumer having a first work conduit for receipt of pressure fluid to cause said consumer to effect movement of a load in a first direction and having a second work conduit for receipt of pressure fluid to cause said consumer to effect movement of such load in opposite second direction; a tank; a supply conduit and a pump for pumping fluid from said tank into said supply conduit; a preselector valve having a first port connected to said supply conduit, a second port connected to said tank, a third port and a fourth port connected to said second work conduit of said double-acting consumer, said preselector valve having a first position in which fluid communication is established in said preselector valve between said first and fourth ports and also between said second and third ports and having a second position in which fluid communication is established in said preselector valve between said first and third ports and also between said second and fourth ports; a control valve having a first port connected to said first work conduit of said double-acting consumer and having a second port connected to said third port of said selector valve and having a first position in which fluid communication between said ports of said control valve in said control valve is blocked and having a second position in which fluid communication between said ports of said control valve in said control valve is established; and pressure-regulating means connected between said fourth port of said preselector valve and said tank and operative for regulating the fluid pressure in said second work conduit.
Claim 3
Dependent Claim
125 words
The apparatus defined in claim 1, and further including an additional consumer having a respective first work conduit for receipt of pressure fluid to cause said second consumer to efFect movement of a load in a first direction, and further including an additional control valve having a respective first port connected to said first work conduit of said additional consumer and having a respective second port connected to said third port of said preselector valve and having a respective first position in which fluid communication between said ports of said additional control valve in said additional control valve is blocked and having a respective second position in which fluid communication between said ports of said additional control valve in said additional control valve is established.
Claim 4
Dependent Claim
59 words
The apparatus defined in claim 2, said additional consumer further having a respective second work conduit for receipt of pressure fluid to cause said additional consumer to effect movement of its load in a second direction opposite the respective first direction, said second work conduit of said additional consumer being connected to said fourth port of said preselector valve.
Claim 5
Dependent Claim
80 words
The apparatus defined in claim 1, and further including a check valve connected between said first and second ports of said preselector valve with an orientation allowing the flow of fluid through said check valve from said second port of said preselector valve to said first port of said preselector valve, whereby the flow of fluid into said first work conduit will cause a sucking of fluid into said second work conduit of said consumer device via said check valve.
Claim 6
Dependent Claim
71 words
The apparatus defined in claim 1, wherein said pressure-regulating means comprises a flow restrictor connected between said fourth port of said preselector valve and said tank and operative for diverting back to said tank part of the fluid flowing out of said fourth port of said preselector valve and into said second work conduit, whereby to maintain the fluid pressure in said second work conduit at a less than maximum value.
Claim 7
Dependent Claim
12 words
The apparatus defined in claim 5, wherein said flow restrictor is adjustable.
Claim 8
Dependent Claim
59 words
The apparatus defined in claim 1, wherein said pressure-regulating means comprises a pressure-limiting valve having one port connected to said fourth port of said preselector valve and another port connected to said tank and operative for limiting the pressure of fluid flowing out of said fourth port of said preselector valve into said second work conduit of said consumer.
Claim 9
Dependent Claim
86 words
The apparatus defined in claim 1, wherein said control valve is of the seated-valve-member type and is comprised of at least one valve member movable between first and second positions to respectively cause said control valve to assume said first and second positions thereof, spring biasing means for normally urging said at least one valve member to the first position thereof, and actuating means for opposing the force of said spring biasing means to bring said at least one valve member to the second position thereof.
Claim 10
Dependent Claim
82 words
The apparatus defined in claim 1, wherein said preselector valve is comprised of at least one valve member movable between first and second positions to respectively cause said preselector valve to assume said first and second positions thereof, spring biasing means for normally urging said at least one valve member to the first position thereof and single-acting electromagnet means operative for opposing the force of said spring biasing means and moving said at least one valve member to the second position thereof.
Claim 11
Dependent Claim
42 words
The apparatus defined in claim 1, wherein said preselector valve has an intermediate third position in which fluid communication is established in said preselector valve among said second, third and fourth ports thereof and in which said first port thereof is blocked.
Claim 12
Dependent Claim
30 words
The apparatus defined in claim 1, wherein said preselector valve has an intermediate third position in which fluid flow through said first, second, third and fourth ports thereof is blocked.
Claim 13
Dependent Claim
44 words
The apparatus defined in claim 1, further including a check valve connected between said supply conduit and said fiRst port of said preselector valve with such a direction as to permit flow through said check valve into said first port of said preselector valve.
Claim 14
Dependent Claim
27 words
The apparatus defined in claim 1; and further comprising additional pressure-regulating means operative for regulating the pressure of fluid in said first work conduit of said consumer.
Claim 15
Dependent Claim
40 words
The apparatus defined in claim 1; and further comprising additional pressure-regulating means connected between said first port of said preselector valve and said tank and operative for regulating the pressure of fluid entering said first port of said preselector valve.
Claim 16
Dependent Claim
23 words
The appratus defined in claim 13, wherein said additional pressure-regulating means comprises a pressure-limiting valve connected between said supply conduit and said tank.
Claim 17
Dependent Claim
42 words
The apparatus defined in claim 2, wherein the two consumers are the moving means of a hydraulic-lift tail gate arrangement mounted for swinging movement under the control of the first consumer and for vertical movement under the control of the additional consumer.
Claim 18
Dependent Claim
49 words
The apparatus defined in claim 1, wherein said pressure-regulating means comprises means operative for maintaining the fluid pressure in said second work conduit at a first value; and further including additional pressure-regulating means operative for maintaining the fluid pressure in said first work conduit at a higher second value.
Claim 19
Dependent Claim
74 words
The apparatus defined in claim 1, wherein said pressure-regulating means comprises pressure-limiting means connected between said fourth port of said preselector valve and said tank and operative for limiting the pressure of fluid in said second work conduit to a first constant value, and further including pressure-limiting means connected between said supply conduit and said tank and operative for limiting the pressure of fluid in said supply conduit to a higher second constant value.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |