Electronic pedal assembly and method for providing a tuneable hysteresis force

• US 6,523,433 B1
• Filed: 11/21/2000
• Issued: 02/25/2003
• Est. Priority Date: 11/23/1999
• Status: Expired due to Fees

• Current Assignee: William C. Staker
• Original Assignee: William C. Staker
• Inventors: Staker, William C.
• Primary Examiner(s): Lavinder, Jack
• Assistant Examiner(s): SICONOLFI, ROBERT
• Application Number:
  US09/717,599
• Time in Patent Office: 826 Days
• Field of Search: 745/12, 745/13, 745/14, 745/60, 188/83
• US Class Current: 74/513
• CPC Class Codes: G05G 1/30 Controlling members actuated by foot
• CPC Class Codes: Y10T 74/20534 Accelerator
• CPC Class Codes: Y10T 74/20888 Pedals

Abstract

An electronic throttle control pedal pivotally couples a lever arm to a pedal beam and biases the beam for resisting an applying force to the pedal beam and for biasing sliding surfaces together in frictional contact. A compression spring carried between a mounting bracket and the lever arm biases the pedal beam toward an idle position while at the same time causing a frictional force between the frictional surfaces, such that displacing the pedal beam with an applying force compresses the spring which increases a frictional force between the friction surfaces with an increasing displacement of the pedal beam distal end, and reducing the displacement through a retracting force on the pedal beam distal end expands the compression spring and returns the pedal beam to the idle position through a hysteresis force response for the pedal beam displacement. The hysteresis can be tuned by modifying element dimensions of the pedal.

Claims

1. A pedal comprising:

a base having a surface thereon;

a pedal beam rotatably connected to the base;

an arm member having a medial portion pivotally coupled to the pedal beam, the arm member having a friction surface on a first arm portion for slidably engaging the surface of the base and a second arm portion opposing the first arm portion pivotal about the medial portion; and

biasing means operable with the arm member second arm portion for biasing the pedal beam toward a preselected position while simultaneously biasing the friction surface of the arm member first arm portion against the surface of the base,

wherein rotating the pedal beam with an applying force to a free end thereof results in a frictional force between the arm member and the base with an increasing displacement of a pedal free end, and wherein reducing the displacement through a retracting force returns the pedal to the preselected position through a hysteresis force response for the pedal beam displacement, the retracting force being less than the applying force by a predetermined amount for a preselected displacement.

2. A pedal according to claim 1, further comprising a boss pivotal within a depression carried by the arm member medial portion for pivotally coupling the arm member to the pedal beam.

3. A pedal according to claim 1, wherein the first arm portion includes a longitudinal axis generally orthogonal to a longitudinal axis of the second arm portion.

4. A pedal according to claim 1, wherein the friction surface of the arm member comprises a convex surface, and wherein the surface of the base engaging the convex surface comprises a concave surface.

5. A pedal according to claim 4, wherein each of the convex and concave surfaces is defined by a radius of curvature centered about an axis of rotation of the pedal beam.

6. A pedal according to claim 1, further comprising a stop carried by the base for limiting rotation of the pedal beam to the preselected position.

7. A pedal according to claim 1, wherein a longitudinal axis of the arm member extends through a pivot point thereof, and wherein the friction surface engages the surface of the base along a friction plane axis oriented at an angle to the longitudinal axis of the arm member.

8. A pedal according to claim 1, wherein the biasing means comprise at least one compression spring.

9. A pedal according to claim 1, wherein the base comprises a mounting bracket.

10. A pedal according to claim 9, further comprising a shaft carried by the mounting bracket, wherein the pedal beam is rotatable about the shaft.

11. A pedal according to claim 10, wherein a proximal end of the pedal beam is connected to the shaft and a distal end comprises a free end having a pedal pad thereon for applying a force thereto for displacing the distal end and rotating the pedal beam about the shaft.

12. A pedal according to claim 1, further comprising a position sensor responsive to rotation of the pedal beam for providing an electrical signal representative of pedal rotation about the rotation axis and thus pedal pad displacement.

13. A pedal useful for operation with a motor vehicle having an electronic throttle control system, the pedal comprising:

a mounting bracket for mounting the pedal to a vehicle wall;

a shaft carried by the bracket;

a pedal beam having a proximal end operable with the shaft and a distal end operable by a user for applying a force thereto for displacement thereof and rotation of the pedal beam about a rotation axis;

a friction block carried by the mounting bracket, the friction block having a first friction surface thereon.

a lever arm operable with the pedal beam, the lever arm having opposing first and second arm members pivotal about a medial portion therebetween, the medial portion pivotally coupled to the pedal beam, wherein the first arm member includes a second friction surface slidably engaging the first friction surface of the friction block; and

a compression spring operable between the mounting bracket and the lever arm for biasing the pedal beam toward an idle position through a biasing force on the lever arm, and further biasing the second friction surface against the first friction surface,

wherein displacing the pedal beam distal end by applying an applying force thereto compresses the compression spring which increases a frictional force between the first and second friction surfaces with an increasing displacement of the pedal beam distal end, and wherein reducing the displacement through a retracting force on the pedal beam distal end expands the compression spring and returns the pedal beam to the idle position through a hysteresis force response for the pedal beam displacement, the retracting force being less than the applying force for a given displacement.

14. A pedal according to claim 13, further comprising a position sensor responsive to rotation of the pedal beam about the shaft for providing an electrical signal representative of the rotation.

15. A pedal according to claim 13, wherein each of the first and second friction surfaces comprises an arcuate surface.

16. A pedal according to claim 13, wherein the first friction surface comprises a concave surface and the second friction surface comprises a convex surface, and wherein each of the convex and concave surfaces is defined by a radius of curvature centered about the rotation axis of the pedal beam.

17. A pedal according to claim 13, wherein a longitudinal axis of the first arm portion extends through a pivot point thereof, and wherein the second friction surface engages the first surface along a friction plane axis defining an orientation of the first and second friction surfaces at an angle to the longitudinal axis of the first arm portion.

18. A pedal according to claim 13, wherein the first arm member is generally orthogonal to the second arm member, and wherein a medial portion therebetween is pivotally coupled with the pedal beam, and wherein the second arm member is operable with the compression spring for rotating the first arm member about the medial portion for biasing the second friction surface thereof against the first friction surface.

19. A pedal according to claim 18, further comprising a boss extending from the pedal beam and operable with a depression extending within the medial portion for pivotally coupling the lever arm to the pedal beam.

20. A pedal according to claim 18, further comprising a position sensor responsive to a rotation of the pedal beam for providing an electrical signal representative of the pedal rotation about an axis of rotation and thus pedal pad displacement.

21. A method for providing a preselected hysteresis force response during displacement of a pedal, wherein the pedal includes a pedal beam pivotally connected to a base for rotation about a shaft carried by the base, the method comprising:

pivotally coupling an arm member to the pedal beam, the arm member having a friction surface positioned engaging a surface of the base for slidable movement thereon wherein the arm member includes opposing first and second arm portions pivotal about a medial portion therebetween, and wherein the pivotally coupling includes the coupling of the medial portion with the pedal beam, and wherein the first arm portion includes the friction surface; and

biasing the pedal beam toward a preselected position through a biasing force on the second arm portion of the arm member, while simultaneously biasing the friction surface of the arm member against the surface of the base,

wherein rotating the pedal beam with an applying force to a free end of the pedal beam creates a frictional force between the arm member and the base with an increasing displacement of a pedal beam free end, and wherein reducing the displacement through a retracting force returns the pedal to the preselected position through a hysteresis force response for the pedal beam displacement, the retracting force being less than the applying force by a predetermined amount for a preselected displacement.

22. A method according to claim 21, wherein the first arm portion includes a longitudinal axis generally orthogonal to a longitudinal axis of the second arm portion.

23. A method according to claim 22, further comprising providing the first and second arm portions having preselected length dimensions for providing a preselected biasing of the friction surface of the arm member against the surface of the base.

24. A method according to claim 21, wherein a longitudinal axis of the arm member extends through a pivot point thereof, and wherein the friction surface engages the surface of the base along a friction plane axis oriented at an angle to the longitudinal axis of the arm member, and wherein the method comprises orienting the friction plane axis at a preselected orientation.

25. A method according to claim 21, further comprising sensing rotation of the pedal beam for providing an electrical signal representative of pedal rotation about the rotation axis and thus pedal pad displacement.

26. A pedal comprising:

a base having a surface thereon;

a pedal beam connected to the base for movement about an axis of rotation;

an arm member pivotally coupled to the pedal beam, the arm member having a friction surface positioned engaging a surface of the base for slidable movement thereon, wherein the friction surface of the arm member includes a convex shaped surface and the surface of the base engaging the convex shaped surface includes a concave surface, and wherein each of the convex and concave surfaces is defined by a radius of curvature centered about the axis of rotation of the pedal beam; and

biasing means operable with the pedal beam and arm member for biasing the pedal beam toward a preselected position through a biasing force on the arm member, while simultaneously biasing the friction surface of the arm member against the surface of the base,

wherein rotating the pedal beam with an applying force to a free end of the pedal beam creates a frictional force between the arm member and the base with an increasing displacement of a pedal free end, and wherein reducing the displacement through a retracting force returns the pedal to the preselected position through a hysteresis force response for the pedal beam displacement, the retracting force being less than the applying force by a predetermined amount for a preselected displacement.

27. A pedal comprising:

a base;

a friction block carried by the base, the friction block having an arcuate surface thereon;

a pedal beam rotatably connected to the base;

an arm member having first and second arm portions and a medial portion therebetween, the arm member medial portion pivotally coupled to the pedal beam, the arm member first arm portion having a friction surface positioned for engaging the arcuate surface of the friction block for slidable movement thereon; and

biasing means operable with the arm member second arm portion for biasing the pedal beam toward a preselected position through a biasing force thereon, while simultaneously biasing the friction surface of the arm member first arm portion against the friction block,

wherein rotating the pedal beam with an applying force to a free end thereof results in a frictional force between the arm member and the friction block with an increasing displacement of a pedal free end, and wherein reducing the displacement through a retracting force returns the pedal to the preselected position through a hysteresis force response for the pedal beam displacement, the retracting force being less than the applying force by a predetermined amount for a preselected displacement.