Patent ID: 6318082
Filing Date: 2001-11-20
Classification: B60T

Abstract:
A master cylinder comprising:a cylinder housing which has a connecting passage connected to a reservoir and a piston which is freely slidable in a cylinder hole of the cylinder housing, said piston configuring a pressure chamber, the pressure chamber and the reservoir being in fluid communication through the connecting passage and a communicating hole provided on a portion of said piston,said portion comprising a reduced outside diameter portion defined by a radially inward step surface on the periphery of said piston, a sleeve fitted onto an outer periphery of said reduced outside diameter portion of said piston,wherein a radial passage groove is formed between a radial portion of said step surface of said piston and an end surface of said sleeve opposite to said radial portion of said step surface and an axial passage groove is formed between an inner surface of said sleeve and an outer peripheral surface of said reduced outside diameter portion of said piston and said axial passage groove intersects said radial passage groove whereby said communicating hole is formed by said radial passage groove and said axial passage groove.