Bicycle bottom bracket

Abstract

A crankset is provided with a spindle rotatably disposed through a bottom bracket shell; two pedal cranks each including a bifurcation at one end and a through hole formed through one arm of the bifurcation; and two compression collars each including a lengthwise slit, two yoke arms each projecting out of the compression collar, a through aperture through one end of one yoke arm, and a threaded hole through one end of the other yoke arm. The through aperture is aligned with the threaded hole. Each compression collar is complimentarily engaged with the bifurcation. Either end of the spindle anchored in the compression collar. Either fastener is driven into either end of the spindle to fasten the compression collar and the spindle together. Either bolt is driven through the through hole and the through aperture into the threaded hole to fasten the pedal crank and the compression collar together.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to bicycle parts and more particularly to a bicycle bottom bracket with improved characteristics.

[0003] 2. Description of Related Art

[0004] Conventionally, a bicycle crank comprises one hole at one end for connecting to a pedal and the other hole at the other end for connecting to an axle of bottom bracket. The other hole includes ridges and grooves on an inner surface. Either end of the axle includes ridges and grooves on an outer surface so that the axle may be co-rotated with the rotating crank. There are gaps between the ridges of the crank and the axle. Thus, the ridges of the crank may impact ridges of the axle when a rider starts to rotate the crank. Disadvantageously, this not only makes noise when riding but also causes wear between the ridges. The larger the gaps the sooner the crank disengages from the axle. Thus, the need for improvement still exists.

SUMMARY OF THE INVENTION

[0005] It is therefore one object of the invention to provide a bicycle bottom bracket comprising a spindle rotatably disposed through a bottom bracket shell; two pedal cranks each including a bifurcation at one end and a through hole formed through one arm of the bifurcation; and two compression collars each including a lengthwise slit, two opposite yoke arms each projecting out of the compression collar, a through aperture formed through the open end of one yoke arm, and a threaded hole formed through the open end of the other yoke arm, wherein the through aperture is aligned with the threaded hole; wherein each of the compression collars is complimentarily engaged with the bifurcation; wherein either end the spindle is matingly inserted into the compression collar; wherein two fasteners each are driven into either end of the spindle to fasten the compression collar and the spindle together; and wherein two pinch bolts each are driven through the through hole and the through aperture into the threaded hole to fasten the pedal crank and the compression collar together.

[0006] The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is an exploded view of a pedal crank and a compression collar of a bicycle bottom bracket according to the invention;

[0008] FIG. 2 is a perspective view of the assembled pedal crank and compression collar of FIG. 1;

[0009] FIG. 3 is a perspective view of the compression collar;

[0010] FIG. 4 is a side elevation of the compression collar shown in FIG. 3;

[0011] FIG. 5 is a sectional view taken along line 5-5 of FIG. 4;

[0012] FIG. 6 is an exploded view of the assembled pedal crank, compression collar, and a pedal to be mounted on a spindle which is rotatably disposed through a bottom bracket shell of a bicycle;

[0013] FIG. 7 is a perspective view of the assembled bottom bracket shown in FIG. 6; and

[0014] FIG. 8 is a sectional view taken along line 8-8 of FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

[0015] Referring to FIGS. 1 to 8, a bottom bracket in accordance with the invention is shown. The bottom bracket is part of drive of a bicycle 1. The bottom bracket comprises the following components as discussed in detail below.

[0016] A spindle 12 is rotatably disposed through a bottom bracket shell 11 with both splined ends exposed. Two pedal cranks 2 each are an elongated hollow member having one holed end attached to a pedal (not numbered) and the other bifurcated end 20. A through hole 21 is formed through one arm of the other bifurcated end 20.

[0017] Two compression collars 3 each are shaped as a split cylinder and comprise a lengthwise slit 31, a through opening 32 being partially splined on its inner surface, and two opposite yoke arms 33 each having one end integrally formed with the main body of the compression collar 3 and the other open end projecting out of the main body of the compression collar 3 a short distance. As shown in FIG. 4, two gaps 333 are formed between top of the yoke arm 33 and the main body of the compression collar 3 and between bottom of the yoke arm 33 and the main body of the compression collar 3 respectively. A through aperture 331 is formed through the open end of one yoke arm 33 and a threaded hole 332 is formed through the open end of the other yoke arm 33. The through aperture 331 is aligned with the threaded hole 332.

[0018] The compression collar 3 is sized and shaped to the other bifurcated end 20 so that in assembly the compression collar 3 may be complimentarily engaged with the other bifurcated end 20 with the through aperture 331, the threaded hole 332, and the through hole 21 being aligned. Next, insert one end of the spindle 12 into the through opening 32 of the compression collar 3 so as to matingly engage the spindle 12 with the compression collar 3. Next, drive two screws 5 each into internal threads (not shown) formed in one splined end of the spindle 12 to fasten the compression collar 3 and the spindle 12 together. Finally, drive two pinch bolts 4 each through the through hole 21 and the through aperture 331 into the threaded hole 332 to fasten the pedal crank 2 and the compression collar 3 together.

[0019] It is envisaged by the invention that the invention has a decreased number of components, is easy to assemble or detach, and is durable.

[0020] While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims.

Claims

1. A crankset comprising: a spindle rotatably disposed through a bottom bracket shell; two pedal cranks each including a bifurcation at one end and a through hole formed through one arm of the bifurcation; and two compression collars each including a lengthwise slit, two opposite yoke arms each projecting out of the compression collar, a through aperture formed through one yoke arm, and a threaded hole formed through the other yoke arm, the threaded hole being aligned with the through aperture; wherein each of the compression collars is complimentarily engaged with the bifurcation of the pedal crank; wherein either end the spindle is releasably fastened in the compression collar; and wherein two threaded fasteners each are driven through the through hole of the bifurcation and the through aperture of the compression collar into the threaded hole of the compression collar to fasten the pedal crank and the compression collar together.

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