Patent ID: 7488134

Claim:
A coupling structure, comprising: a shaft body having a slip-off preventing groove and a positioning recess close to an end portion thereof; a shaft joint having an engagement groove with which the shaft body is engaged and, bores facing the engagement groove; a flexible member which projects in the depth direction of the engagement groove, extends externally from the engagement groove along a longitudinal direction of the engagement groove, and engages an engagement face in the positioning recess such that the flexible member regulates movement of the shaft body in the longitudinal direction of the engagement groove; and a coupling shaft, which is inserted into the bores and the slip off preventing groove, for coupling the shaft body and the shaft joint, wherein: the flexible member is configured to be deflected in a width direction of the engagement groove for engaging the engagement face, the flexible member has a deflection regulating portion, the deflection regulating portion being substantially planar and including a planar surface facing a side face of the engagement groove, a tip of the flexible member is bent outward in a width direction of the engagement groove, and the tip of the flexible member extending externally from the engagement groove along a longitudinal direction of the engagement groove is accessible to be bent outward in order to deflect the flexible member and disengage the flexible member from the positioning recess.