US3822759A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power steering gear assembly
Assignee: RH Sheppard Co Inc
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Filing: 1972-03-07
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Granted: 1974-07-09
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Expires: 1992-03-07
Abstract
Abstract The cylinder housing of a power steering gear is provided with a hollow piston having a rack meshing with the output gear, also enclosed within said housing. Fluid check valve means are provided at each end of the piston to prevent passage of high pressure working fluid during the power stroke but to allow the escape of high pressure fluid from the hollow interior of the piston to the exhausted or soft side of the piston. Lateral ports are provided in the piston communicating with the hollow interior and with the rack to bleed high pressure fluid from the enclosing space of the output gear so that buildup of fluid pressure due to leakage past the piston sealing rings is prevented. The check valve means are mounted in caps closing off the hollow interior of the piston and fluid is supplied and withdrawn from the chambers through a single fluid transfer hose at each end. The gear assembly is particularly adapted to use as a slave power steering gear unit, which is designed to provide 50 percent of the force in a dual system with 50 percent being handled by the master unit.
Inventors
- 👤 R Sheppard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:53
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/06; B62D5/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
210 words
A power steering gear assembly and steering system for a vehicle having wheels or the like comprising a cylinder housing, a double acting piston in said housing forming chambers at opposite ends, said ends being fixed relative to each other and a fixed length rack formed on one side of said piston, an output steering gear meshing with said rack, a steering crank connected to said gear, steering linkage between said crank and said wheels, a low pressure space in said housing separated from said chambers by the ends of said pistons and enclosing said gear, single fluid transfer means for each of said chambers to allow alternate introduction of high pressure working fluid to one of said chambers to power the piston and concurrent exhausting of the other chamber, check valve means at each end of said piston communicating with the adjacent chamber and having closed positions in opposite directions so as to prevent escape of high pressure working fluid from said one chamber, passageway means in said piston communicating with said check valve means and said low pressure space, said check valve means allowing escape of fluid from said low pressure space to said other chamber being exhausted, whereby build-up of fluid pressure in said space is prevented.
Claim 2
Dependent Claim
210 words
A power steering gear assembly and steering system for a vehicle having wheels or the like comprising a cylinder housing, a double acting piston in said housing forming chambers at opposite ends, said ends being fixed relative to each other and a fixed length rack formed on one side of said piston, an output steering gear meshing with said rack, a steering crank connected to said gear, steering linkage between said crank and said wheels, a low pressure space in said housing separated from said chambers by the ends of said pistons and enclosing said gear, single fluid transfer means for each of said chambers to allow alternate introduction of high pressure working fluid to one of said chambers to power the piston and concurrent exhausting of the other chamber, check valve means at each end of said piston communicating with the adjacent chamber and having closed positions in opposite directions so as to prevent escape of high pressure working fluid from said one chamber, passageway means in said piston communicating with said check valve means and said low pressure space, said check valve means allowing escape of fluid from said low pressure space to said other chamber being exhausted, whereby build-up of fluid pressure in said space is prevented.
Claim 3
Dependent Claim
61 words
The assembly and system of claim 1 wherein said piston is formed hollow along the length, said passageway means includes the hollow interior of said piston, and cap means concentric with said piston for housing each check valve means and spring Means in said cap means assuring closing off the ends of the hollow interior against admission of high pressure fluid.
Claim 4
Dependent Claim
26 words
The assembly and system of claim 2 wherein said cap means are threadably engaged with said piston and is the sole support for said valve means.
Claim 5
Dependent Claim
77 words
The assembly and system of claim 1 wherein said piston is formed hollow along the length, said passageway means includes the hollow interior of said piston and lateral port means from said interior to the exterior of said piston at said rack and communicating with said space, said rack being recessed sufficiently to allow transfer of fluid therefrom, whereby escape of fluid to said space may be effected at any position of said piston along said cylinder.
Claim 6
Dependent Claim
38 words
The assembly and system of claim 4 wherein said port means includes a first and second port adjacent opposite ends of said piston to allow substantially unrestricted flow from said space in any shifted position of said piston.
Claim 7
Dependent Claim
54 words
The assembly and system of claim 1 wherein said check valve means at each end comprises a ball, a seat on the side toward said low pressure space, and a spring biasing said ball against said seat, said spring being only sufficient to allow unseating and exhaust at approximately 5 pounds per square inch.
Claim 8
Dependent Claim
37 words
The assembly and system of claim 6 wherein is included cap means housing said check valve means, said seat being integral with said cap and removable to allow easy replacement of parts of said check valve means.
Claim 9
Dependent Claim
66 words
The assembly and system of claim 1 wherein said chambers communicate directly with said valve means, said fluid transfer means comprises first and second fluid lines to accommodate both pressure and exhaust for respective ones of said chambers, first and second end plate means for closing the ends of said cylinder housing, and means for attaching said lines to respective ones of said end plate means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |