Patent US3698188A successfully refreshed from Google Patents.
US3698188A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power-assisted steering mechanisms for motor vehicles
Assignee: Adwest Engineering Ltd
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Filing: 1970-12-18
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Granted: 1972-10-17
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Expires: 1990-12-18
Abstract
Abstract Power-assisted steering mechanism for a motor vehicle comprising a double-acting power-assist piston and cylinder means, a valve having a member movable to connect one side or the other of the power-assist piston and cylinder means with a source of fluid under pressure, and control means for controlling the movement of the movable valve member, the control means comprising a closed hydrostatic circuit which includes at least one positive displacement pump motor adapted for actuation by a manual steering control.
Inventors
- 👤 Leslie Richard Jenvey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:48
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/06; B62D5/10; B62D5/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
210 words
Power-assisted steering mechanism for a motor vehicle, the mechanism comprising double-acting power-assist piston and cylinder means adapted to be connected to the steerable road wheels of a motor vehicle to impart steering thereto, a first port whereby the interior of the power-assist cylinder can be placed in communication with a source of fluid under pressure to move the power-assist piston in one direction, a second port whereby the interior of the power-assist cylinder can be placed in communication with a source of fluid under pressure to move the power-assist piston in the opposite direction, a valve having a member movable to connect either one of said ports with a said source of fluid under pressure, double-acting control piston and cylinder means, means operatively connecting the control piston with the movable valve member, and a reversible positive displacement pump motor which is adapted for actuation by a manual steering control and which is connected with said control piston and cylinder means in a closed hydrostatic circuit whereby one side of the positive displacement pump motor is connected with one side of the double-acting control piston and cylinder means and the other side of the displacement pump motor is connected with the other side of the double-acting control piston and cylinder means.
Claim 2
Dependent Claim
210 words
Power-assisted steering mechanism for a motor vehicle, the mechanism comprising double-acting power-assist piston and cylinder means adapted to be connected to the steerable road wheels of a motor vehicle to impart steering thereto, a first port whereby the interior of the power-assist cylinder can be placed in communication with a source of fluid under pressure to move the power-assist piston in one direction, a second port whereby the interior of the power-assist cylinder can be placed in communication with a source of fluid under pressure to move the power-assist piston in the opposite direction, a valve having a member movable to connect either one of said ports with a said source of fluid under pressure, double-acting control piston and cylinder means, means operatively connecting the control piston with the movable valve member, and a reversible positive displacement pump motor which is adapted for actuation by a manual steering control and which is connected with said control piston and cylinder means in a closed hydrostatic circuit whereby one side of the positive displacement pump motor is connected with one side of the double-acting control piston and cylinder means and the other side of the displacement pump motor is connected with the other side of the double-acting control piston and cylinder means.
Claim 3
Dependent Claim
49 words
Power-assisted steering mechanism according to claim 1, wherein said valve is a spool valve and the movable member thereof is a movable spool, the control piston having a piston rod connected therewith and the movable spool being clamped between washers mounted on the piston rod of the control piston.
Claim 4
Dependent Claim
37 words
Power-assisted steering mechanism according to claim 1 comprising a hollow piston rod connected with the power-assist piston, the control piston being slidable within the hollow piston rod of the power-assist piston which thereby forms the control cylinder.
Claim 5
Dependent Claim
94 words
Power-assisted steering mechanism according to claim 3 comprising a hollow piston rod connected to the control piston and a hollow tube mounted concentrically within the control piston rod so as to define therewith an annular passage, the interior of the hollow tube communicating the interior of the control cylinder on one side of the control piston with one side of said positive displacement pump motor and said annular passage communicating the interior of the control cylinder on the other side of the control piston with the other side of said positive displacement pump motor.
Claim 6
Dependent Claim
31 words
Power-assisted steering mechanism according to claim 1, wherein the movable valve member has a central neutral position, spring means being provided for biassing the movable valve member towards its neutral position.
Claim 7
Dependent Claim
86 words
Power-assisted steering mechanism according to claim 1, comprising a plurality of centralizing pistons associated with the movable valve member, said centralizing pistons being located in the pressure fluid path to the power-assist cylinder whereby when the movable valve member is moved out of a central neutral position, the fluid under pressure passing to the power-assist cylinder will act on said centralizing pistons to bias the movable valve member towards its neutral position with a force which increases with increase in pressure of the fluid under pressure.
Claim 8
Dependent Claim
41 words
Power-assisted steering mechanism according to claim 6, comprising at least one opposed pair of centralizing pistons and a spring mounted between the opposed pair of centralizing pistons and acting on bias the movable valve member towards a said central neutral position.
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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) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |