Patent ID: 7121094

Claim:
A center valve for use in a master cylinder including a cylinder body having a closed front end, and a piston slidably inserted in said cylinder body, said center valve comprising a valve casing formed at a front end of said piston and formed with a passage through which hydraulic fluid can flow, a valve seat fitted in said passage, and a valve body mounted in said passage in front of said valve seat so as to be movable in an axial direction of said passage, said valve seat comprising a core member and an elastic tube fitted on said core member, said elastic tube comprising a front end portion adapted to be pressed against said valve body, and a rear cylindrical portion having an axis parallel to the axis of said passage, said valve body and said valve seat being movable toward and away from each other, said center valve being provided with a gap behind said cylindrical portion of said elastic tube, whereby when said valve body is pressed against said valve seat, said elastic tube is elastically deformed such that at least the rear end of said cylindrical portion protrudes into said gap.