Patent US4256432A successfully refreshed from Google Patents.
US4256432A
Expired / Lapsed
US
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Construction of circuit for working vehicle operable as backhoe and also as dozer
Assignee: Kubota Corp
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Filing: 1978-08-22
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Granted: 1981-03-17
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Expires: 1998-08-22
Abstract
Abstract A hydraulic circuit construction for a working vehicle operable as a backhoe and also as a dozer, the circuit construction comprising a multiplex valve assembly with a dozer control valve for a dozer system, a motor control valve for one of right and left running systems, and an arm confluence valve for supplying pressure fluid to an arm cylinder of a backhoe system from a pump common to the dozer and motor valves are connected in series with one another to the pump, and a change-over valve is provided downstream from the dozer and the motor valves and upstream from the arm confluence valve for interrupting the supply of the pressure fluid from the pump to the arm confluence valve. The above circuit construction enables the vehicle to perform both operations, namely a bulldozing operation without the vehicle being urged to run obliquely, and a successful running out operation from a marshy ground by an arm operation without any one of the running system being urged to stop by the work load of the arm.
Inventors
- 👤 Shiro Sugiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:43
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/20; E02F9/22; E02F9/2278; E02F9/2292; E02F3/00; E02F3/04; E02F3/96; E02F3/963; E02F3/964; E02F9/2221; E02F9/2239; F; F15; F15B; F15B11/00; F15B11/16; F15B11/17; F15B2211/00; F15B2211/20; F15B2211/205; F15B2211/20576; F15B2211/30; F15B2211/305; F15B2211/3056; F15B2211/30585; F15B2211/3059; F15B2211/30595; F15B2211/31; F15B2211/3105; F15B2211/3116; F15B2211/70; F15B2211/71; F15B2211/7142; F15B2211/78
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
264 words
A hydraulic circuit construction for a working vehicle equipped with a backhoe means comprising a dozer means and right and left running means, a first hydraulic motor for one of the running means and a dozer hydraulic cylinder for the dozer means being coupled to be operated by a first hydraulic pump, a second hydraulic motor for the other running means and an arm hydraulic cylinder for an arm of a backhoe means are coupled to be operated by a second hydraulic pump, the arm cylinder being coupled to receive pressure fluid from the first and second pumps at the same time, a second multiplex valve assembly including a second motor control valve for the second motor and an arm control valve for the arm cylinder being connected in parallel with each other to the second pump, a first multiplex valve assembly including a dozer control valve for the dozer cylinder, a first motor control valve for the first motor and an arm confluence control valve for supplying pressure fluid from the first pump to the arm cylinder, wherein said dozer valve, said first motor valve and said arm confluence valve are connected in series with one another to the first pump with the arm confluence valve being positioned downstream from the dozer and the first motor valves and a change-over valve for interrupting supply of pressure fluid to the arm confluence valve is provided downstream from the dozer and first motor valves and upstream from the confluence valve in multiplex valve arrangement in combination with the dozer, first motor and arm confluence valves.
Claim 2
Dependent Claim
264 words
A hydraulic circuit construction for a working vehicle equipped with a backhoe means comprising a dozer means and right and left running means, a first hydraulic motor for one of the running means and a dozer hydraulic cylinder for the dozer means being coupled to be operated by a first hydraulic pump, a second hydraulic motor for the other running means and an arm hydraulic cylinder for an arm of a backhoe means are coupled to be operated by a second hydraulic pump, the arm cylinder being coupled to receive pressure fluid from the first and second pumps at the same time, a second multiplex valve assembly including a second motor control valve for the second motor and an arm control valve for the arm cylinder being connected in parallel with each other to the second pump, a first multiplex valve assembly including a dozer control valve for the dozer cylinder, a first motor control valve for the first motor and an arm confluence control valve for supplying pressure fluid from the first pump to the arm cylinder, wherein said dozer valve, said first motor valve and said arm confluence valve are connected in series with one another to the first pump with the arm confluence valve being positioned downstream from the dozer and the first motor valves and a change-over valve for interrupting supply of pressure fluid to the arm confluence valve is provided downstream from the dozer and first motor valves and upstream from the confluence valve in multiplex valve arrangement in combination with the dozer, first motor and arm confluence valves.
Claim 3
Dependent Claim
53 words
A hydraulic circuit construction as defined in claim 1 wherein said change-over valve is operatively connected to the first motor control valve and coupled to automatically interrupt the supply of pressure fluid to the arm confluence control valve when the first motor valve is operated to supply pressure fluid to the first motor.
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) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |