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 at the side of the crank arm, and constrained to the crank arm.

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;

FIG. 5 is a cross-section of the pedal coupling area of a crank arm assembly according to another embodiment of the present invention;

FIG. 6 is a cross-section of the pedal coupling area of a crank arm assembly according to another embodiment of the present invention;

FIG. 7 is an enlarged cross-section of the coupling area between the washer and the crank arm of the crank arm assembly of FIG. 6;

FIGS. 8 to 17 are sections of the pedal coupling area of crank arm assemblies according to other embodiments of the present invention;

FIG. 18 is a cross-section of the pedal coupling area of a crank arm assembly according to another embodiment of the present invention, wherein the interface surfaces between the crank arm and the washer have a different extent at different angular positions;

FIG. 19 is a plan view of the crank arm of the crank arm assembly of FIG. 18;

FIGS. 20 to 22 are sections of the pedal coupling area of crank arm assemblies according to other embodiments of the present invention, wherein the interface surfaces between the crank arm and the washer have a different extent at different angular positions; and

FIG. 23 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 defining 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 at said side of the crank arm, and constrained to the crank arm.

2. Crank arm assembly according to claim 1, wherein the reinforcing element has a portion configured to receive an abutment portion of said axle resting upon it.

3. Crank arm assembly according to claim 1, wherein in the direction of an axis of the hole, the reinforcing element has a shorter extent than the extent of the hole.

4. Crank arm assembly according to claim 3, wherein in the direction of the axis, the reinforcing element has an extent of less than half the extent of the hole.

5. Crank arm assembly according to claim 4, wherein in the direction of the axis, the reinforcing element has an extent of less than one fifth of the extent of the hole.

6. Crank arm assembly according to claim 1, wherein in the direction of an axis of the hole, the reinforcing element has an extent comprised 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 among steel, titanium alloy, and aluminum alloy.

9. Crank arm assembly according to claim 1, wherein said constraint comprises gluing.

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

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

12. Crank arm assembly according to claim 1, wherein said constraint comprises a caulking.

13. Crank arm assembly according to claim 12, wherein said constraint comprises a caulking of the crank arm and/or of the reinforcing element around a seat for the reinforcing element.

14. Crank arm assembly according to claim 1, wherein the crank arm is made from a composite material and said constraint is accomplished by co-molding of the reinforcing element in said crank arm.

15. Crank arm assembly according to claim 1, wherein the reinforcing element is constrained onto the outer surface of the side of the crank arm.

16. Crank arm assembly according to claim 1, wherein the crank arm and the reinforcing element are in contact along a respective interface surface not entirely contained in a plane transversal to an axis of the hole.

17. Crank arm assembly according to claim 16, wherein the interface surfaces have an overall sloping progression with respect to the axis.

18. Crank arm assembly according to claim 17, wherein the interface surfaces are conical surfaces.

19. Crank arm assembly according to claim 18, wherein the generating line of the conical interface surfaces is sloping with respect to a plane perpendicular to the axis by an angle comprised between 5° and 45°.

20. Crank arm assembly according to claim 17, wherein the interface surfaces are rotational surfaces having a curvilinear generating line with at least two inflexion points.

21. Crank arm assembly according to claim 17, wherein the interface surfaces are rotational surfaces having a curvilinear generating line with one inflexion point.

22. Crank arm assembly according to claim 17, wherein the interface surfaces are rotational surfaces having a generating line shaped as an arc of circumference.

23. Crank arm assembly according to claim 17, wherein the interface surfaces are rotational surfaces having a stepped generating line.

24. Crank arm assembly according to claim 17, wherein the interface surfaces are multi-faceted.

25. Crank arm assembly according to claim 24, wherein the interface surfaces are frustum of pyramid-shaped surfaces.

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

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

28. Crank arm assembly according to claim 16, wherein the interface surfaces between the crank arm and the reinforcing element have a different extent at different angular positions about the axis.

29. Crank arm assembly according to claim 28, wherein the interface surfaces between the crank arm and the reinforcing element are eccentric surfaces with respect to the hole.

30. Crank arm assembly according to claim 29, wherein an axis of the interface 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°.

31. Crank arm assembly according to claim 28, wherein the interface surfaces between the crank arm and the reinforcing element have a different slope at different angular positions about the axis.

32. 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 defining 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, at said side, a seat for a reinforcing element extending around the hole.

33. Crank arm according to claim 32, wherein said seat is a recessed seat communicating with the hole.

34. Crank arm according to claim 32, wherein said seat is a seat protruding from the crank arm.

35. Crank arm according to claim 32, wherein the seat has a flat bottom.

36. Crank arm according to claim 32, wherein the seat has a cylindrical side wall.

37. Crank arm according to claim 36, wherein the cylindrical side wall is eccentric with respect to the axis of the hole.

38. Reinforcing element comprising a flat circular body having an eccentric hole.

39. 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 hole extending from a side of the crank arm for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element extending around said hole at said side of the crank arm, and constrained to the crank arm,wherein said crank arm and said reinforcing element are in contact along essentially conical mutual contact surfaces.

40. The bicycle crank arm assembly according to claim 39, wherein said crank arm comprises a recessed seat for housing said reinforcing element.

41. The bicycle crank arm assembly according to claim 39, wherein said constraint comprises a caulking.

42. The bicycle crank arm assembly according to claim 39, wherein said generating line of said conical interface surfaces is sloping with respect to a plane perpendicular to an axis of said hole by an angle comprised between 5° and 45°.

43. The bicycle crank arm assembly according to claim 39, wherein said reinforcing element comprises an annular shape.

44. The bicycle crank arm assembly according to claim 39, wherein the configuration of said reinforcing element is continuous around an axis of said hole.

45. The bicycle crank arm assembly according to claim 39, wherein in the direction of an axis of said hole, said reinforcing element has an extent comprised between one pitch of an internal threading of said hole and twice said pitch.

46. 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 and constrained to the crank arm,wherein said crank arm and said reinforcing element are in contact along a respective substantially conical interface surface.

47. A bicycle crank arm assembly comprising: a crank arm comprising a first end for coupling with a bottom bracket assembly,a second end for coupling with a pedal, at least one of said first end and said second end defining 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, anda recessed seat; andan annular-shaped reinforcing element continuously extending around said hole and housed within said recessed seat at said side of the crank arm, and constrained to the crank arm,wherein said crank arm and said reinforcing element are in contact along a respective conical interface surface.

48. A bicycle crank arm assembly comprising: a crank arm comprising a first end for coupling with a bottom bracket assembly,a 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 recessed seat; andan annular-shaped reinforcing element continuously extending around said hole and housed within said recessed seat and constrained to the crank arm,wherein said crank arm and said reinforcing element are in contact along a respective substantially conical interface surface.

49. 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 hole extending from a side of the crank arm for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element extending around said hole at said side of the crank arm, and constrained to the crank arm, the overall reinforced element being positioned in a zone close to the edge of the hole.

50. The bicycle crank arm assembly according to claim 49 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.

51. The bicycle crank arm assembly according to claim 50 wherein the hole is defined by an internally threaded surface for coupling with a threading of the axle, while the reinforced element has a smooth surface facing the embraced free area.

52. 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 defining 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 constrained to the crank arm, the reinforcing element embracing a free area with a cross section greater than a cross section of the hole close to the reinforced element.

53. 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 hole for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element, extending around the hole, and constrained to the crank arm, the reinforcing element having a portion configured for receiving an abutment portion of said axle resting upon it,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, 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.

54. 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 hole extending from a side of the crank arm for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element extending around said hole at said side of the crank arm, and fixed to the crank arm by caulking.

55. 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 hole extending from a side of the crank arm for coupling with an axle of the pedal or of the bottom bracket assembly, respectively; anda reinforcing element extending around said hole at said side of the crank arm, and fixed to the crank arm by gluing.