US4047590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic circuit for steering control in articulate vehicles
Assignee: Komatsu Ltd
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Filing: 1975-12-05
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Granted: 1977-09-13
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Expires: 1995-12-05
Abstract
Abstract A hydraulic circuit for steering control in articulate vehicles which comprises an engine, a fixed displacement pump driven by the engine, a variable displacement pump driven by the engine, an exit port of the variable displacement pump being connected to a control valve of a steering actuator, an orifice provided at an outlet side of the fixed displacement pump and, a controlling cylinder connected to the variable displacement pump for controlling displacement of the variable displacement pump, the controlling cylinder being actuated by a spring disposed therein and a differential hydraulic pressure at the orifice.
Inventors
- 👤 Kenzo Hoashi
- 👤 Nobuaki Inaba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:28
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/06; B62D5/09
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
203 words
A hydraulic circuit for steering control in articulate vehicles including a prime mover said circuit comprising: a fixed displacement pump driven by said prime mover, the output of said fixed displacement pump being directly proportional to the speed of said prime mover; a variable displacement pump driven by said prime mover, the output of said variable displacement pump being connected to a control valve of a steering actuator; control cylinder means including a piston rod for controlling displacement of said variable displacement pump and a spring acting on said piston rod, said control cylinder means being connected to the fixed displacement pump through a first pipe; restricting means having one side connected to the output of said fixed displacement pump through a branch pipe from said first pipe; a reservoir coupled to the other side of said restricting means; wherein said control cylinder means is actuated by the force of said spring and an opposite force resulting from a differential hydraulic pressure at said restricting means and whereby the output of said variable displacement pump is held constant irrespective of the speed of said prime mover; and linkage means interconnecting said variable displacement pump and the piston rod of said control cylinder means.
Claim 2
Dependent Claim
203 words
A hydraulic circuit for steering control in articulate vehicles including a prime mover said circuit comprising: a fixed displacement pump driven by said prime mover, the output of said fixed displacement pump being directly proportional to the speed of said prime mover; a variable displacement pump driven by said prime mover, the output of said variable displacement pump being connected to a control valve of a steering actuator; control cylinder means including a piston rod for controlling displacement of said variable displacement pump and a spring acting on said piston rod, said control cylinder means being connected to the fixed displacement pump through a first pipe; restricting means having one side connected to the output of said fixed displacement pump through a branch pipe from said first pipe; a reservoir coupled to the other side of said restricting means; wherein said control cylinder means is actuated by the force of said spring and an opposite force resulting from a differential hydraulic pressure at said restricting means and whereby the output of said variable displacement pump is held constant irrespective of the speed of said prime mover; and linkage means interconnecting said variable displacement pump and the piston rod of said control cylinder means.
Claim 3
Dependent Claim
19 words
A hydraulic circuit for steering control in articulate vehicles of claim 1, wherein said restricting means is an oricice.
Claim 4
Dependent Claim
36 words
A hydraulic circuit for steering control in articulate vehicles of claim 1 wherein said variable displacement pump includes a swash plate and said piston rod of is coupled to the swash plate by said linkage means.
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) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |