Patent ID: 9027439
Filing Date: 2015-05-12
Classification: B62M,Y10T

Abstract:
1. A crank arm, comprising: a first connecting member, having a first wall surface, one end of the first wall surface defined as a first pivot end and an opposite end of the first wall surface defined as a first drive end, the first pivot end being opened with a first axle hole therethrough, the first wall surface being provided with a joint wall; and a second connecting member engaged with the first connecting member, the second connecting member being provided with a second wall surface opposite to the first wall surface, one end of the second wall surface defined as a second pivot end and an opposite end of the second wall surface defined as a second drive end, and the second wall surface being opened with a second axle hole for joining the first axle hole, and a groove being used for fitting the joint wall therein; wherein, the joint wall and the groove have a continuous annular structure, and the wall surfaces of the joint wall and the groove are designed to be a wave shape for withstanding the shear force derived from the first connecting member and the second connecting member when these two connecting members are engaged.