| 摘要 |
<P>PROBLEM TO BE SOLVED: To eliminate a danger that a seal of a U shape cross section stored between the inner wall of a master cylinder and a piston is rolled up, popped out or broken at abrupt braking. <P>SOLUTION: The sealing means 21 stored between the piston 4 and an inner hole 3 of the master cylinder is constituted of an outer lip 27, an inner lip 28 and an intermediate radial crown 29. A rigid reinforcement member 25 is fitted into the inner lip 28 and formed on the peripheral edge of the inner lip 28 to form a ring. The rigidity prevents the upsetting of the inner lip 28 caused by the rubbing of the piston 4 relative to the sealing means 21. Further, in order to retain the piston 4 in the inner hole 3 of the master cylinder, a groove 31 is formed on the circumference of the piston and is designed such that the sealing means 21 is stored in the groove 31 when it is positioned at a non-operation position. When such positioning is performed, the sealing means 21 prevents the piston 4 from coming off from the inner hole 3 of the master cylinder. <P>COPYRIGHT: (C)2007,JPO&INPIT |
