Patent ID: 7178645
Filing Date: 2007-02-20
Classification: F16D

Abstract:
1. A brake apparatus comprising: a rotor; a friction member; a caliper; a cylinder having a cylinder chamber and provided on the caliper; a piston, for pressing the friction member to the rotor, arranged in the cylinder; and an automatic clearance adjusting mechanism with an overadjustment preventer for properly maintaining a clearance between the friction member and the rotor, provided between the cylinder and the piston; wherein the piston includes: the plug piston and the adjusting nut are directly integrally assembled by a holder, wherein the bearing and a bearing support plate are interposed between the adjusting nut and the holder, and the holder is directly engaged with the plug piston, and wherein, in adjusting a clearance, the adjusting nut is extracted from the adjusting spindle by a hydraulic operation of the plug piston until the adjusting nut is hampered from being pivoted by frictionally coupling with the plug piston, in preventing overadjustment, the adjusting nut is hampered from being pivoted by pressing the friction portion of the adjusting nut to the plug piston via the bearing support plate by an operation of the ring piston, and in operating a parking brake, the friction portion of the adjusting nut is pressed to the plug piston via the adjusting spindle, wherein the holder includes a first outer side claw portion extended to a side of the plug piston, and the first outer side claw portion is formed with an engaging claw that engages with a groove provided at an outer peripheral face of the plug piston on a side opposed to the rotor, and the first outer side claw portion extends over an outer circumference of the bearing support plate and an outer circumference of the bearing to clamp the bearing support plate to the plug piston.