US3872670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selectively actuatable shock absorbing system for an implement control circuit
Assignee: Caterpillar Inc
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Filing: 1973-05-02
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Granted: 1975-03-25
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Expires: 1993-05-02
Abstract
Abstract Hydraulic control system for holding a work implement in a fixed position, said system including selectively operative shock absorbing means for negating any large force experienced by the implement on contact with an immovable object.
Inventors
- 👤 Joseph E Dezelan
- 👤 John A Junck
- 👤 Walter I Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:47
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/20; E02F9/22; E02F9/2217; E02F9/2203; E02F9/2207; F; F15; F15B; F15B1/00; F15B1/02; F15B13/00; F15B13/01
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
136 words
A hydraulic system for selectively holding an implement or the like in a fixed position and for selectively providing shock absorbing means for the implement comprising: a hydraulic motor; a source of fluid pressure; first control valve means comprising lock valve means disposed in a motor control circuit between said source of fluid pressure and said hydraulic motor for selectively directing said fluid to and from said motor; and shock absorbing means comprising fluid accumulator means and control means including second control valve means independent of said first control valve means including pilot operated lock valve means disposed between said fluid accumulator means and said hydraulic motor and operated by a pilot control circuit independent of said motor control circuit and including a twoposition selector valve for selectively communicating said fluid accumulator means with said motor.
Claim 2
Dependent Claim
136 words
A hydraulic system for selectively holding an implement or the like in a fixed position and for selectively providing shock absorbing means for the implement comprising: a hydraulic motor; a source of fluid pressure; first control valve means comprising lock valve means disposed in a motor control circuit between said source of fluid pressure and said hydraulic motor for selectively directing said fluid to and from said motor; and shock absorbing means comprising fluid accumulator means and control means including second control valve means independent of said first control valve means including pilot operated lock valve means disposed between said fluid accumulator means and said hydraulic motor and operated by a pilot control circuit independent of said motor control circuit and including a twoposition selector valve for selectively communicating said fluid accumulator means with said motor.
Claim 3
Dependent Claim
16 words
The hydraulic system of claim 1 wherein said fluid accumulator means comprises a gas charged accumulator.
Claim 4
Dependent Claim
62 words
The hydraulic system of claim 1 wherein said lock valve means of said selector valve means comprises: passage means connecting said fluid accumulator means with said motor; check valve means disposed in said passage means to normally isolate said fluid accumulator means from said motor; means for unseating said check valve Means to provide communication between said accumulator means and said motor.
Claim 5
Dependent Claim
37 words
The hydraulic system of claim 1 wherein said means for unseating said check valve means comprises: a pressure responsive piston; and said second valve means is operatively connected for directing fluid from said source to said piston.
Claim 6
Dependent Claim
22 words
The hydraulic system of claim 4 including a source of electrical power and manually operable switch means for selectively activating said solenoids.
Claim 7
Dependent Claim
64 words
The hydraulic system of claim 1 including a second hydraulic motor; a second accumulator for connection to said second motor, said pilot-operated lock valve means includes a second lock valve disposed between said second hydraulic motor and said second accumulator for controlling communication between said second motor and said second accumulator; and said second control valve means includes a pair of solenoid-operated two-position valves.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |