Jidosha Kiki Co., Ltd.

Jidoshi Kiki Co., Ltd.

Toshiaki Satoh

Kunio Yanagi

Kimio Ishihara

The present invention discloses a master cylinder MC, which comprises a body section 2, a cap 3, a cylinder housing 1 composed of the body section 2 and the cap 3, a sleeve 8 fitted in the cylinder housing 1, primary and secondary pistons 4 and 5 provided to be guided by the sleeve 8 and slid, first and second pressure chambers 9 and 10 and spring mechanisms 11 and 12 respectively disposed in the first and second pressure chambers for pressing the primary and secondary pistons 4 and 5 in returning directions. In the peripheral portion 17a of the spring retainer 17 of the spring mechanism 11 for pressing the primary piston 4, hook sections 17e are formed by protruding a plurality of portions 17d outward in an axial direction and then folding the tip of each of the protruded portions in a piston axial direction so as to hook the same in the outer peripheral surface of the sleeve 8. Thus, even if an excessive pulling-out force is applied to the primary piston, easy pulling-out of the primary piston can be prevented without deforming the spring retainer.

Master cylinder

A cap which is so constructed that parts manufacture and product assembly are facilitated. The construction is such that a cap for a master cylinder reservoir connects a cover cap and a body cap with each other and a diaphragm is disposed in a space formed therebetween to provide a valve function. The cover cap has a concentric cylindrical portion and an annular protrusion, while the body cap has a funnel portion at its center and an annular disc portion at the periphery of the funnel portion. The diaphragm is fitted between the inner periphery of annular protrusion of the cover cap and the outer periphery of the funnel portion of the body cap. The diaphragm forms a suction valve and an exhaust valve together with the cylindrical portion and the annular disc portion, respectively.

Growing community of inventors

Higashimatsuyama, Japan

Toshiaki Satoh