Image Number 2 for United States Patent #7178645.
A brake apparatus having an automatic clearance adjusting mechanism with an overadjustment preventer constituted such that a piston is constituted by a structure of being divided in a plug piston 16 and a ring piston 14. The plug piston 16 is integrated with an adjusting nut 20, a bearing 21, a bearing support plate 22 and a spring holder 23. An outer side claw portion 23a of the holder is locked by an outer side groove 16 of the plug piston. The plug piston 16 integrated with the respective parts is inserted to fit to the ring piston 14 to thereby prevent the outer side claw portion 23a of the holder from being detached.