US3739868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid power steering apparatus
Assignee: Aisin Corp
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Filing: 1971-02-19
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Granted: 1973-06-19
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Expires: 1991-02-19
Abstract
Abstract Disclosed herein is a fluid power steering apparatus for vehicles. A hydraulic circuit including a pressure source is connected to a cylinder having a piston slidably engaged therein to define a pair of opposed pressure chambers therein. The piston is connected to a sector-shaft which in turn is connected to the steering road wheels. A rotatable member is confined within the piston and connected to a manually actuated shaft. A pair of control valves mounted in the piston are adapted to be displaced relatively in opposite directions by the rotatable member. The pair of control valves are positioned in the piston during assembly and are fixed normally in the neutral positions thereof to make the assembly easy and simple giving the control valves accurate and durable performance.
Inventors
- 👤 T Maekawa
- 👤 A Suzuki
- 👤 S Haramura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:43
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/06; B62D5/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
270 words
A fluid power steering apparatus for vehicles comprising a cylinder adapted to receive hydraulic operating fluid under pressure connected from a source, a piston mounted within said cylinder for axial sliding movement and defining a pair of pressure chambers at opposite ends of said cylinder, a sectorshaft mounted in said cylinder for operative connection with the steering road wheels of a vehicle and operatively connected to said piston, a rotatable member confined within said piston and connected operatively with a manually rotated shaft extending into said cylinder, and open center control valve means for controlling the supply of operating fluid into said pair of chambers in response to rotation of said shaft, said open center control valve means including a first control valve having an outer sleeve member fixedly secured in a first bore in said piston, a spool valve received in said sleeve member, and a first spring for normally maintaining said spool valve in neutral position in said outer sleeve member, a second control valve having a second Outer sleeve member mounted for axial movement in a second bore in said piston, a second spool valve slidably engaged in said outer sleeve member, and a second spring for normally maintaining said second spool valve in neutral position in said second outer sleeve member, a pair of connecting members secured on said rotatable member engaged with said first and second spool valves to displace them axially and oppositely upon rotation of said shaft, and a member fixing said second outer sleeve member in said piston in axially adjusted relation with said first and second spool valves in neutral position.
Claim 2
Dependent Claim
270 words
A fluid power steering apparatus for vehicles comprising a cylinder adapted to receive hydraulic operating fluid under pressure connected from a source, a piston mounted within said cylinder for axial sliding movement and defining a pair of pressure chambers at opposite ends of said cylinder, a sectorshaft mounted in said cylinder for operative connection with the steering road wheels of a vehicle and operatively connected to said piston, a rotatable member confined within said piston and connected operatively with a manually rotated shaft extending into said cylinder, and open center control valve means for controlling the supply of operating fluid into said pair of chambers in response to rotation of said shaft, said open center control valve means including a first control valve having an outer sleeve member fixedly secured in a first bore in said piston, a spool valve received in said sleeve member, and a first spring for normally maintaining said spool valve in neutral position in said outer sleeve member, a second control valve having a second Outer sleeve member mounted for axial movement in a second bore in said piston, a second spool valve slidably engaged in said outer sleeve member, and a second spring for normally maintaining said second spool valve in neutral position in said second outer sleeve member, a pair of connecting members secured on said rotatable member engaged with said first and second spool valves to displace them axially and oppositely upon rotation of said shaft, and a member fixing said second outer sleeve member in said piston in axially adjusted relation with said first and second spool valves in neutral position.
Claim 3
Dependent Claim
27 words
A device as claimed in claim 1 wherein said first outer sleeve member is pressed firmly into its operative position where it is fixed within said piston.
Claim 4
Dependent Claim
40 words
A device as claimed in claim 1 wherein the member fixing said second outer sleeve member in adjusted position in said piston is a fixing pin extending through said piston and locking said second sleeve member in axially adjusted position.
Claim 5
Dependent Claim
39 words
A device as claimed in claim 1 wherein each of said outer sleeve members are rigidly secured against axial movement with respect to said piston by means of fixing pins extending through said pistons into said outer sleeve members.
Claim 6
Dependent Claim
229 words
A fluid power steering apparatus for vehicles comprising a housing defining a cylinder, a piston mounted within said cylinder for axial sliding movement and defining a pair of pressure chambers within said cylinder at opposite ends of said piston, a sector-shaft mounted in said cylinder for operative connection with the steering road wheels of a vehicle and operatively connected to said piston, a rotatable member confined within said piston and connected operatively with a manually rotated shaft extending into said cylinder, a pair of control valves for controlling operating fluid supplied into said pair of pressure chambers in response to rotation of said shaft, and an hydraulic circuit including a first inlet passage in said housing adapted to be connected with a source of hydraulic operating fluid under pressure, a second inlet passage in said piston and connected with said first inlet passage, a first outlet passage in said piston connected to said second inlet passage through said pair of control valves for controlling supply of operating fluid into said pair of pressure chambers from said second inlet passage, a first intermediate passage formed between said piston and said shaft and connected with said first outlet passage, a second intermediate passage provided axially in said shaft and connected with said first intermediate passage, and a second outlet passage formed in said housing and connected with said second intermediate passage.
Claim 7
Dependent Claim
229 words
A fluid power steering apparatus for vehicles comprising a housing defining a cylinder, a piston mounted within said cylinder for axial sliding movement and defining a pair of pressure chambers within said cylinder at opposite ends of said piston, a sector-shaft mounted in said cylinder for operative connection with the steering road wheels of a vehicle and operatively connected to said piston, a rotatable member confined within said piston and connected operatively with a manually rotated shaft extending into said cylinder, a pair of control valves for controlling operating fluid supplied into said pair of pressure chambers in response to rotation of said shaft, and an hydraulic circuit including a first inlet passage in said housing adapted to be connected with a source of hydraulic operating fluid under pressure, a second inlet passage in said piston and connected with said first inlet passage, a first outlet passage in said piston connected to said second inlet passage through said pair of control valves for controlling supply of operating fluid into said pair of pressure chambers from said second inlet passage, a first intermediate passage formed between said piston and said shaft and connected with said first outlet passage, a second intermediate passage provided axially in said shaft and connected with said first intermediate passage, and a second outlet passage formed in said housing and connected with said second intermediate passage.
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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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |