US4970646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle having secondarily steered front and rear wheels
Assignee: Nissan Motor Co Ltd
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Filing: 1988-11-10
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Granted: 1990-11-13
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Expires: 2008-11-10
Abstract
Abstract A method of steering a vehicle having a set of steerable front wheels and a set of steerable rear wheels. The front and rear wheels are both secondarily steered in addition to a main steer of the front wheels caused by an operation of a front wheel steering gear in response to an operation of a steering wheel. The method comprises providing to the front wheels a secondary steer angle corresponding to at least a differentiated value of a steer angle of a steering wheel in such a way as to increase an overall steer angle of the front wheels and providing to the rear wheels a secondary steer angle proportional to the steer angle of the steering wheel and in the same direction as the steer angle of the front wheels.
Inventors
- 👤 Fukashi Sugasawa
- 👤 Kazunori Mori
- 👤 Kenji Kawagoe
- 👤 Hiroshi Mouri
- 👤 Junsuke Kuroki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:43
CPC Classifications
B; B62; B62D; B62D7/00; B62D7/06; B62D7/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
108 words
A method of steering a vehicle having a set of steerable front wheels and a set of steerable rear wheels which are both secondarily steered upon main steering of the front wheels by operation of a steering wheel, the method comprising: providing to said front wheels a secondary steer angle corresponding to at least a differentiated value of a steering wheel operation, to increase an overall steer angle of said front wheels; and providing, with a time-lag of a first order, to said rear wheels a secondary steer angle proportional to said steering wheel operation and of the same phase as said steer angle of said front wheels.
Claim 2
Independent Claim
108 words
A method of steering a vehicle having a set of steerable front wheels and a set of steerable rear wheels which are both secondarily steered upon main steering of the front wheels by operation of a steering wheel, the method comprising: providing to said front wheels a secondary steer angle corresponding to at least a differentiated value of a steering wheel operation, to increase an overall steer angle of said front wheels; and providing, with a time-lag of a first order, to said rear wheels a secondary steer angle proportional to said steering wheel operation and of the same phase as said steer angle of said front wheels.
Claim 3
Dependent Claim
29 words
A method as set forth in claim 1 wherein said differentiated value of said steering wheel operation is a differentiated value of a steer angle of said steering wheel.
Claim 4
Dependent Claim
24 words
A method as set forth in claim 2 wherein said said secondary steer angle of said front wheels is related to a vehicle speed.
Claim 5
Dependent Claim
109 words
A method as set forth in claim 3 wherein said first mentioned providing comprises detecting said steer angle of said steering wheel and said vehicle speed and computing a front wheel secondary steer target angle δf and a rear wheel secondary steer target angle δr from the following formulas, δf=Kf·θ+Tf·θ ##EQU2## where θ is a steer angle of the steering wheel, θ is a differentiated value of the steer angle θ, Kf and Kr are proportional constants which are functions of vehicle speed, Tf is a differential constant which is a function of vehicle speed, and τ is a time constant which is a function of a vehicle speed.
Claim 6
Dependent Claim
48 words
A method as set forth in claim 4 wherein said first mentioned providing further comprises detecting a front wheel secondary steer actual angle δF and a rear wheel secondary steer actual angle δR, and controlling the front and rear wheel steer so that δf=δF and δr=δR are attained.
Claim 7
Dependent Claim
69 words
A method as set forth in claim 1 wherein said first mentioned providing comprises detecting said steer angle of said steering wheel and said vehicle speed and computing a front wheel secondary steer target angle δf from the following formula, δf=Tf·θ where Tf is a differential constant which is a function of vehicle speed and θ is a differentiated value of a steer angle θ of said steering wheel.
Claim 8
Dependent Claim
36 words
A method as set forth in claim 6 wherein said first mentioned providing further comprises detecting a front wheel secondary steer actual angle δF and controlling the front wheel secondary steer so that δf=δF is attained.
Claim 9
Dependent Claim
36 words
A method as set forth in claim 7 wherein said second mentioned providing is performed so that said secondary steer angle of said rear wheels is directly proportional to a steer angle of said steering wheel.
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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) | 1993-11-12 | 1994-05-14 | 1994-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-12 | 1998-05-14 | 1998-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-12 | 2002-05-14 | 2002-11-13 | $7700.00 | Window Closed / Lapsed |