Patent ID: 9657753
Date: 2017-05-23
CPC Classifications: B60T,F15B

Claim:
1. A master cylinder assembly in a brake system; a housing disposed along an axis defining a chamber extending between an open end and a closed end to define a wall extending annularly in said chamber, a cylinder disposed for sliding movement axially along said axis in said chamber including a cylindrical wall extending axially to an open distal end with a plurality of fluid flow apertures located closely adjacent said open distal end, a piston including a piston wall extending cylindrically and axially to a distal end, said cylindrical wall of said cylinder including a cylinder ramp having an axial length and presenting a first frusto-conical surface extending annularly about said cylindrical wall of said cylinder to define a cylinder ramp shoulder, wherein said cylinder ramp is spaced from said open end of said cylinder with said plurality of fluid flow apertures located between said cylinder ramp and said open distal end of said cylinder, said distal end of said piston wall including a piston ramp presenting a second frusto-conical surface extending annularly about said piston wall and tapering radially inwardly toward said axis at a constant angle and wherein said piston ramp further defines a piston ramp shoulder so that said frusto-conical surfaces slidably engage one another to radially compress said distal end of said piston and snap into an assembled position wherein said shoulders radially engage one another to limit the axial movement of the piston relative to the cylinder, a spring captured inside said piston and in contact with a spring seat located within said cylinder, said spring biasing said cylinder ramp shoulder and said piston ramp shoulder against each other, and an annular seal located in an annular groove in said housing, said seal in alignment with said plurality of fluid flow apertures in said open distal end of said cylinder when said spring fully biases said shoulders against each other thereby sealing said fluid flow apertures.