Patent ID: 8286758

Claim:
A disk brake, comprising: a caliper for slidably fitting a piston into a cylinder having a cylindrical shape with a closed end and for bringing a pair of pads into contact with a disk by sliding of the piston; a cam mechanism provided in a sealed state in a cam chamber formed in the caliper, the cam mechanism varying an amount of projection of a cam rod by being rotationally driven; a transmission member including: an extending portion located inside the cylinder and to extend in an axial direction of the cylinder, the extending portion including a thread portion for adjusting a length; and an inserted portion inserted into a hole for bringing a bottom portion of the cylinder and the cam chamber into communication with each other, the transmission member being pushed by the cam rod of the cam mechanism to transmit a pushing force to the piston; wherein: the transmission member includes: a flange portion integrally formed with the extending portion; an anti-rotation locking portion formed on an outer circumferential portion of the flange portion, the anti-rotation locking portion being slidably fitted into a fitting area on the cylinder so as to restrict rotation relative to the cylinder; and a seal groove formed in the inserted portion, the seal groove storing a sealing member therein for defining the cylinder and the cam chamber and sealing the cam chamber; and the anti-rotation locking portion is formed at a position allowing the anti-rotation locking portion to be fitted into the fitting area on the cylinder before the sealing member is positioned inside the hole when the inserted portion of the transmission member is inserted into the hole.