Bicycle crank arm assembly and related elements

Abstract

A bicycle crank arm assembly is disclosed, comprising a crank arm having a first end for coupling with a bottom bracket assembly and a second end for coupling with a pedal, at least one of the first end and the second end comprising a hole extending from a side of the crank arm for coupling with an axle of the pedal or of the bottom bracket assembly, respectively, further comprising a reinforcing element extending around the hole in the proximity of the side of the crank arm, having a portion configured for receiving an abutment portion of the axle resting upon it, and wherein the crank arm and the reinforcing element contact along a respective surface not entirely contained within a plane perpendicular to an axis of the hole.

Description

BRIEF DESCRIPTION OF THE DRAWING(S)

Further characteristics and advantages of the present invention shall become clearer from the following detailed description of some preferred embodiments thereof, made with reference to the attached drawings, purely as a non-limiting example. In the drawings:

FIG. 1 is a partially sectional side view of a crank arm assembly according to the present invention coupled with the axle of a pedal;

FIG. 2 is an enlarged cross-section of a part of the coupling area between the crank arm assembly and the axle of FIG. 1;

FIG. 3 is an enlarged cross-section of a part of the pedal coupling area of the crank arm assembly of FIG. 1, wherein the forces acting on a reinforcing element thereof are schematically shown;

FIG. 4A is a plan view of the crank arm of the crank arm assembly of FIG. 1, wherein the forces acting on the reinforcing element are schematically shown;

FIG. 4B is a partial exploded view of the crank arm and washer of the crank arm assembly of FIG. 1;

FIGS. 5 to 11 are sections of the pedal coupling area of crank arm assemblies according to other embodiments of the present invention;

FIG. 12 is a cross-section of the pedal coupling area of a crank arm assembly according to another embodiment of the present invention;

FIG. 13 is an enlarged cross-section of the coupling area between the washer and the crank arm of the crank arm assembly of FIG. 12;

FIG. 14 is a cross-section of the pedal coupling area of a crank arm assembly according to another embodiment of the present invention;

FIG. 15 is a cross-section of the pedal coupling area of a crank arm assembly according to another embodiment of the present invention, wherein the mutual contact surfaces of the crank arm and the washer have a different extent at different angular positions;

FIG. 16 is a plan view of the crank arm of the crank arm assembly of FIG. 15;

FIG. 17 is a section of the pedal coupling area of crank arm assembly according to another embodiment of the present invention, wherein the mutual contact surfaces of the crank arm and the washer have a different extent at different angular positions; and

FIG. 18 is a partial perspective view of a crank arm assembly according to another embodiment of the present invention.

Claims

1. A bicycle crank arm assembly comprising a crank arm having a first end for coupling with a bottom bracket assembly and a second end for coupling with a pedal, at least one of said first end and said second end comprising a hole extending from a side of the crank arm for coupling with an axle of the pedal or of the bottom bracket assembly, respectively, further comprising a reinforcing element, extending around the hole in the proximity of said side of the crank arm, having a portion configured for receiving an abutment portion of said axle resting upon it, and wherein the crank arm and the reinforcing element contact along a respective surface not entirely contained within a plane perpendicular to an axis through the hole.

2. Crank arm assembly according to claim 1, wherein the mutual contact surfaces have an overall sloping progression with respect to the axis.

3. Crank arm assembly according to claim 1, wherein in the direction of the axis, the extent of said mutual contact surfaces is shorter than the extent of the hole.

4. Crank arm assembly according to claim 3, wherein in the direction of the axis, the extent of said mutual contact surfaces is shorter than half the extent of the hole.

5. Crank arm assembly according to claim 4, wherein in the direction of the axis, the extent of said mutual contact surfaces is shorter than one fifth of the extent of the hole.

6. Crank arm assembly according to claim 1, wherein in the direction of the axis, the extent of said mutual contact surfaces comprises between one pitch of an internal threading of the hole and twice the pitch.

7. Crank arm assembly according to claim 1, wherein the reinforcing element has a greater modulus of elasticity than that of the crank arm.

8. Crank arm assembly according to claim 1, wherein the reinforcing element is made from a material selected from the group comprised of steel, titanium alloy, and aluminum alloy.

9. Crank arm assembly according to claim 1, wherein the mutual contact surfaces are conical surfaces.

10. Crank arm assembly according to claim 9, wherein a generating line of the conical mutual contact surfaces is sloping with respect to a plane perpendicular to the axis by an angle comprised between 5° and 45°.

11. Crank arm assembly according to claim 1, wherein the mutual contact surfaces are rotational surfaces having a curvilinear generating line with at least one inflexion point.

12. Crank arm assembly according to claim 11, wherein the curvilinear generating line has at least two inflexion points.

13. Crank arm assembly according to claim 1, wherein the mutual contact surfaces are rotational surfaces having a stepped generating line.

14. Crank arm assembly according to claim 1, wherein the mutual contact surfaces are rotational surfaces having a generating line shaped as an arc of circumference.

15. Crank arm assembly according to claim 1, wherein the mutual contact surfaces are multi-faceted surfaces.

16. Crank arm assembly according to claim 15, wherein the mutual contact surfaces are frustum of pyramid-shaped surfaces.

17. Crank arm assembly according to claim 1, wherein the contact surface of the reinforcing element overall converges towards the crank arm, and the contact surface of the crank arm overall diverges towards the reinforcing element.

18. Crank arm assembly according to claim 1, wherein the contact surface of the reinforcing element overall diverges towards the crank arm, and the contact surface of the crank arm overall converges towards the reinforcing element.

19. Crank arm assembly according to claim 1, wherein the crank arm comprises a recessed seat for housing the reinforcing element.

20. Crank arm assembly according to claim 1, wherein the crank arm comprises a protruding seat for housing the reinforcing element.

21. Crank arm assembly according to claim 1, further comprising a mechanical constraint between the crank arm and the reinforcing element.

22. Crank arm assembly according claim 21, wherein said mechanical constraint comprises a caulking.

23. Crank arm assembly according to claim 22, wherein the crank arm comprises a recessed seat for housing the reinforcing element, and said mechanical constraint comprises a caulking of the crank arm or of the reinforcing element around the seat for the reinforcing element.

4. Crank arm assembly according to claim 22, wherein the crank arm comprises a protruding seat for housing the reinforcing element, and said mechanical constraint comprises a caulking of the crank arm or of the reinforcing element around said seat.

25. Crank arm assembly according to claim 21, wherein the crank arm is made from a composite material and said mechanical constraint is accomplished by co-molding of the reinforcing element in said crank arm.

26. Crank arm assembly according to claim 1, wherein the mutual contact surfaces between the crank arm and the reinforcing element have a different extent at different angular positions about the axis.

27. Crank arm assembly according to claim 26, wherein the mutual contact surfaces between the crank arm and the reinforcing element are eccentric surfaces with respect to the hole.

28. Crank arm assembly according to claim 27, wherein the axis of the mutual contact surfaces is parallel to the axis, and defines, with the axis, a plane sloping with respect to a longitudinal center line of the crank arm by an angle comprised between 30° and 70°.

29. Crank arm assembly according to claim 26, wherein the mutual contact surfaces of the crank arm and the reinforcing element have a different slope at different angular positions about the axis.

30. A bicycle crank arm having a first end for coupling with an axle of a bottom bracket assembly and a second end for coupling with a pedal, at least one of said first end and said second end comprising a hole extending from a side of the crank arm for coupling with an axle of the pedal or respectively of the bottom bracket assembly, comprising, in the proximity of said side, a surface configured for contacting a reinforcing element not entirely contained within a plane perpendicular to an axis of the hole.

31. Crank arm according to claim 30, wherein the contact surface defines a recessed seat in the crank arm.

32. Crank arm according to claim 30, wherein the contact surface defines a protrusion in the crank arm.

33. Crank arm according to claim 30, wherein the contact surface is a rotational surface.

34. Crank arm according to claim 33, wherein the rotational surface is a conical surface.

35. Crank arm according to claim 33, wherein the rotational surface has a curvilinear generating line with at least one inflexion point.

36. Crank arm according to claim 33, wherein the rotational surface has a stepped generating line.

37. Crank arm according to claim 33, wherein the rotational surface has a generating line shaped as an arc of circumference.

38. Crank arm according to claim 30, wherein the contact surface is multi-faceted.

39. Crank arm according to claim 38, wherein the contact surface is frustum of pyramid-shaped.

40. Crank arm according to claim 30, wherein the contact surface has a different extent at different angular positions about the axis.

41. Crank arm according to claim 28, wherein the contact surface is an eccentric surface with respect to the hole.

42. Crank arm according to claim 40, wherein the contact surface has a different slope at different angular positions about the axis.

43. A reinforcing element for a bicycle crank arm comprising a hole that allows passage of an axle of a pedal or of a bottom bracket assembly, respectively, a portion configured for receiving an abutment portion of said axle resting upon it, and a surface configured for contacting the crank arm not entirely contained within a plane perpendicular to an axis of the hole.

44. Reinforcing element according to claim 43, wherein the abutment portion comprises an abutment surface essentially opposite the contact surface.

45. Reinforcing element according to claim 43, wherein the contact surface is conical.

46. Reinforcing element according to claim 43, wherein the contact surface is a rotational surface having a curvilinear generating line with at least one inflexion point.

47. Reinforcing element according to claim 43, wherein the contact surface is a rotational surface having a generating line shaped as an arc of circumference.

48. Reinforcing element according to claim 43, wherein the contact surface is a rotational surface having a stepped generating line.

49. Reinforcing element according to claim 43, wherein the contact surface is multi-faceted.

50. Reinforcing element according to claim 49, wherein the contact surface is a frustum of pyramid-shaped surface.

51. Reinforcing element according to claim 43, wherein the contact surface is eccentric with respect to the hole.

52. A bicycle crank arm assembly comprising: a crank arm comprising a first end for coupling with a bottom bracket assembly, anda second end for coupling with a pedal, at least one of said first end and said second end comprising a hole extending from a side of said crank arm for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element extending around said hole in the proximity of said side of said crank arm, said reinforcing element comprising a portion configured for receiving an abutment portion of said axle resting upon it,wherein said crank arm and said reinforcing element contact along essentially conical mutual contact surfaces.

53. The bicycle crank arm assembly according to claim 52, wherein the crank arm comprises a recessed seat for housing the reinforcing element.

54. The bicycle crank arm assembly according to claim 52, wherein said hole comprises internal threading.

55. The bicycle crank arm assembly according to claim 52, wherein said reinforcing element has a greater modulus of elasticity than that of said crank arm.

56. The bicycle crank arm assembly according to claim 52, wherein a generating line of said conical mutual contact surfaces is sloping with respect to a plane perpendicular to an axis of said hole by an angle comprised between 5° and 45°.

57. The bicycle crank arm assembly according to claim 52, wherein in the direction of an axis of said hole, the extent of said mutual contact surfaces amounts to between one pitch of an internal threading of said hole and twice the pitch.

58. The bicycle crank arm assembly according to claim 52, wherein said reinforcing element comprises an annular shape.

59. The bicycle crank arm assembly according to claim 52, wherein the configuration of said reinforcing element is continuous around an axis of said hole.

60. A bicycle crank arm assembly comprising: a crank arm comprising a first end for coupling with a bottom bracket assembly, anda second end for coupling with a pedal, at least one of said first end and said second end defining a traverse hole for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element extending around said hole, said reinforcing element comprising a portion configured for receiving an abutment portion of said axle resting upon it,wherein said crank arm and said reinforcing element contact along a respective substantially conical surface.

61. A bicycle crank arm assembly comprising: a crank arm comprising a first end for coupling with a bottom bracket assembly axle, anda second end for coupling with a pedal axle, at least one of said first end and said second end comprising a hole for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element extending around said hole, and confined in a zone close to an edge of the hole.

62. The bicycle crank arm assembly according to claim 61, wherein the reinforcing element embraces a free area with a cross section greater than a cross section of the hole close to the reinforced element.

63. The bicycle crank arm assembly according to claim 62, wherein the hole is defined by an internally threaded surface for coupling with a threading of the axle, while the reinforcing element has a smooth surface facing the embraced free area.

64. A bicycle crank arm assembly comprising: a crank arm comprising a first end for coupling with a bottom bracket assembly axle, anda second end for coupling with a pedal axle, at least one of said first end and said second end comprising a hole for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element extending around said hole, wherein the reinforcing element embraces a free area with a cross section greater than a cross section of the hole close to the reinforced element.

65. A bicycle crank arm assembly comprising: a crank arm comprising a first end for coupling with a bottom bracket assembly, anda second end for coupling with a pedal, at least one of said first end and said second end defining an hole for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element, extending around the hole, and having a portion configured for receiving an abutment portion of said axle resting upon it, andwherein the crank arm and the reinforcing element contact along a respective surface not entirely contained within a plane perpendicular to an axis through the hole, andwherein the contact surface of the reinforcing element overall converges towards the crank arm, and the contact surface of the crank arm overall diverges towards the reinforcing element.