Remotely adjustable steering compensator

• US 4,534,577 A
• Filed: 07/11/1983
• Issued: 08/13/1985
• Est. Priority Date: 11/14/1979
• Status: Expired due to Term

• Current Assignee: Durrell U. Howard
• Original Assignee: Durrell U. Howard
• Inventors: Howard, Durrell U.
• Primary Examiner(s): Peters, Jr., Joseph F.
• Assistant Examiner(s): HILL, MITCHELL
• Application Number:
  US06/512,852
• Time in Patent Office: 764 Days
• Field of Search: 280/90, 280/94, 280/89, 280/271, 280/771, 180/79, 180/141, 180/142, 180/143, 180/213, 180/132, 91/5, 91/390, 91/368, 92/65, 92/131, 92/134, 60/415, 60/417, 74/388 PS, 114/150
• US Class Current: 180/400
• CPC Class Codes: B62D 6/04 responsive only to forces disturbing the intended course of the vehicle, e.g. forces acting transversely to the direction of vehicle travel

Abstract

A steering compensator for providing resistance to movement of a steering system away from a preselected center position until a steering force exceeds a preselected value which may be varied remotely while the vehicle is in operation. The preselected center position may also be varied remotely while the vehicle is in operation by a trim mechanism. The compensator may be rotary or linear and the resistance force may be provided by a variable spring force and/or a variable magnetic force. Optional features include a liquid system for viscous dampening and an undercut seat and cam arrangement for centering without significant slack or overshoot.

Claims

1. A steering compensator apparatus for a steering system of a vehicle having at leat one steerable member movable away from a preselected position in response to a steering force, said apparatus comprising:

cam means including a detent member having at least one centering depression and at least one follower member in contact with opposite sides of said centering depression when said steerable member is in said preselected position;

connecting means for moving said follower member and said detent member relative to each other in response to movement of said steerable member away from said preselected position;

compression means for pressing together said follower member and said detent member so that contact pressure between said follower member and said centering depression resists relative movement between said detent member and said follower member and prevents substantial movement of said steerable member away from said preselected position until said steering force exceeds a predetermined value;

adjusting means operable for varying the contact pressure between said follower member and said centering depression so as to vary the amount of steering force required for substantial movement of said steerable member away from said preselected position; and

,

control means for remotely operating said adjusting means so as to selectively vary the amount of said contact pressure while said vehicle is in operation.

2. The apparatus of claim 1 in which said follower member has a first radius of curvature and said centering depression has a second radius of curvature substantially smaller than said first radius of curvature so that contact between said follower member and said centering depression occurs along a rim portion of said centering depression.

3. The apparatus of claim 1 in which said compression means includes resilient means for providing a resilient force pressing together said follower member and said detent member, and in which said adjusting means includes varying means for selectively varying the amount of said resilient force.

4. The apparatus of claim 3 in which said varying means includes a reversible electric motor for rotating one threaded member relative to another threaded member.

5. The apparatus of claim 3 in which said resilient means provides said resilient force in response to compression of said resilient means, and in which said varying means selectively varies the amount of said compression.

6. The apparatus of claim 1 in which said compression means includes spring means for biasing said follower member and said detent member toward each other, and in which said adjusting means includes an electric motor and means for causing engagement between said electric motor and said spring means so that operation of said electric motor varies the amount of contact pressure provided by said spring means.

7. The apparatus of claim 1 which further includes trim means operable for varying said preselected position of said steerable member;

and control means for remotely operating said trim means so as to selectively vary said preselected position of said steerable member while said vehicle is in operation.

8. The apparatus of claim 7 which further includes stop means for limiting the range of trimming movement provided by said trim means.

9. The apparatus of claim 7 which further includes slack removal means for removing mechanical slack from said trim means.

10. The apparatus of claim 7 for a steering system having at least one steerable member mounted on a frame, and in which:

said connecting means includes linkage means for connecting said cam means to said frame at a first point of connection and for connecting said cam means to said steering system at a second point of connection in spaced relation to said first point of connection, said spaced relation defining a centered distance when said steerable member is in said preselected position;

said trim means includes drive means operable for causing said linkage means to vary said centered distance; and

,

said control means includes means for remotely operating said drive means so as to selectively vary said centered distance while said vehicle is in operation.

11. The apparatus of claim 10 in which said trim means further includes a first threaded member engaged by a gear means, and in which said drive means includes a reversible electric motor for moving said gear means relative to said first threaded member.

12. The apparatus of claim 11 in which said trim means further includes a second threaded member engaged by said gear means, and slack removal means for moving said first threaded member relative to said second threaded member so as to remove mechanical slack from said threaded engagement.

13. The apparatus of claim 1 which further includes a centering member movable with said steerable member and having a centered position relative to a frame of said vehicle corresponding to the preselected position of said steerable member, and trim means for changing the centered position of said centering member relative to said vehicle frame so as to selectively vary the preselected position of said steerable member while said vehicle is in operation.

14. The apparatus of claim 13 in which said trim means includes drive means for causing trimming movement of said centering member in response to at least one remote input so as to change said centered position while said vehicle is in operation, said control means for selectively providing said at least one remote input to said drive means from a location remote to said cam means such as a driver'"'"'s station of said vehicle.

15. The apparatus of claim 1 in which said cam means includes a plurality of follower members and a common detent member having a plurality of centering depressions one for receiving each of said plurality of follower members.

16. The apparatus of claim 1 in which said follower member engages the rim of said centering depression so as to form a liquid seal between said follower member and said rim, in which said centering depression includes an aperture in spaced relation to said rim, and in which said apparatus further includes liquid means for keeping said centering depression filled with a liquid, said aperture providing fluid resistance to movement of said follower member away from sealing engagement with said rim.

17. The apparatus of claim 1 in which said follower member and said detent member are arranged for linear movement relative to each other.

18. The apparatus of claim 17 in which said detent member comprises a casing and said follower member is arranged for linear movement within said casing.

19. The apparatus of claim 18 in which said follower member includes a pair of opposing detent rollers for engaging at least one centering depression in said casing;

and in which said compression means includes axle member having at least two journals and at least pressure rollers rotatably mounted upon said journals, the rotational axes of said journals being radially offset from each other so that one of said pressure rollers is in contact with one of said detent rollers and the other of said pressure rollers is in contact with the other of said detent rollers.

20. The apparatus of claim 19 in which said casing has an annular centering depression for receiving both of said detent rollers.

21. The apparatus of claim 1 in said follower member and said detent member are arranged for rotary movement relative to each other.

22. The apparatus of claim 21 in which said cam means includes a plurality of rollers in spaced relation to each other, means for retaining said rollers in said spaced relation, and a common detent member having a plurality of centering depressions one for receiving each of said rollers, said centering depressions having a spaced relation corresponding to the spaced relation of said rollers.

23. The apparatus of claim 21 in which said connecting means includes linkage means for connecting said cam means and said steerable member, said linkage means comprising a first member and a second member movable relative to each other between a retracted position and an extended position;

and means for retaining said first and second members in said retracted position when said follower member is in contact with said centering depression.

24. The apparatus of claim 23 in which said retaining means includes biasing means for resiliently biasing said first and second linkage members toward said retracted position.

25. The apparatus of claim 1 which further includes:

adjusting means operable for varying the contact pressure between said follower member and said centering depression so as to vary the amount of steering force required for substantial movement of said steerable member away from said preselected position;

trim means operable for varying said preselected position of said steerable member, and,

control means for remotely operating said adjusting means and/or said trim means so as to selectively vary said contact pressure and/or said preselected position of the steerable member while said vehicle is in operation.

26. The apparatus of claim 1 in which said compression means includes spring means for biasing said follower member and said detent member toward each other so that contact pressure between said follower member and said centering depression resists relative movement between said detent member and said follower member.

27. The apparatus of claim 26 in which said spring means comprises a coil spring.

28. The apparatus of claim 26 in which said spring means comprises a leaf spring.

29. The apparatus of claim 1 which further includes dampening means for providing liquid dampening of the relative movement between said follower member and said detent member.

30. The apparatus of claim 1 for a vehicle having power means for supplementing said steering force, said apparatus further including means for reducing said contact pressure substantially to zero in response to a loss of said steering power.

31. The apparatus of claim 1 for a steering system having a reduction gear between said steerable member and a steering member, and in which said cam means is connected to said steering system at a location between said steerable member and said reduction gear.

32. A steering compensator apparatus for providing a resistance force preventing substantial movement of at least one steerable member away from a preselected position until a steering force exceeds a predetermined value, said apparatus comprising:

fluid means for pressurizing a fluid and causing said fluid to flow in response to movement of said at least one steerable member away from said preselected position;

valve means for preventing said fluid flow until said fluid means provides a preselected amount of differential pressure across said valve means, said valve means including a valve member and a seat member movable relative to each other between an open position providing said fluid flow and a closed position preventing said fluid flow; and

,

magnetic means for providing a magnetic force holding said valve member and said seat member in said closed position until said fluid means provides said preselected amount of differential pressure.

33. The apparatus of claim 32 in which said magnetic means includes means for varying the level of said magnetic force so as to vary the preselected amount of differential pressure at which said valve means provides said fluid flow, and in which said apparatus further includes control means for selectively varying the level of said magnetic force while said vehicle is in operation.

34. A steering compensator apparatus for a steering system of a vehicle having at least one steerable member movable away from a preselected position in response to a steering force, said apparatus comprising:

cam means including at least one follower member and a detent member having at least one centering depression, said at least one follower member having a seated position in contact with opposite sides of said centering depression when said steerable member is in said preselected position;

connecting means for moving said follower member and said detent member relative to each other in response to movement of said steerable member away from said preselected position; and

,

compression means for pressing together said follower member and said detent member so that contact pressure between said follower member and said centering depression resists relative movement between said detent member and said follower member for a predetermined distance to either side of said preselected position;

wherein said contact pressure prevents substantial movement of said steerable member away from said preselected position until said steering force exceeds a predetermined value when said follower member is in said seated position;

and wherein said follower member has a first radius of curvature and said centering depression has a second radius of curvature substantially smaller than said first radius of curvature so that in said seated position said follower member contacts a rim portion of said centering depression, said rim portion having a shape providing substantially a line of contact between said follower member and said centering depression.

35. The apparatus of claim 34 in which said follower member engages the rim of said centering depression so as to form a liquid seal between said follower member and said rim, in which said centering depression includes an aperture in spaced relation to said rim, and in which said apparatus further includes liquid means for keeping said centering depressron filled with a liquid, said aperture providing fluid resistance to movement of said follower member away from sealing engagement with said rim.

36. The apparatus of claim 34 for a steering system having a reduction gear between said steerable member and a steering member, in which said connecting means connects said cam means to a frame of said vehicle and to said steering system at a location between said steerable member and said reduction gear, and in which the location of said steering system connection and the line of contact provided between said follower member and said centering depression when said follower member is in said seated position substantially eliminates mechanical slack between said frame and said steerable member.