Portless type master cylinder device with non return valve and

Abstract

In this portless type master cylinder device, a cylinder bore is formed in a body thereof, and a piston member is fitted in the cylinder bore and is slidably movable from an initial axial position therein and defines a pressure chamber in cooperation with the cylinder bore. An intake valve communicates between the cylinder chamber and the fluid reservoir via a fluid flow path, and is opened when the piston member is in its initial axial position while it is closed when the piston member moves through more than a determinate relatively small axial distance from its initial axial position. Intermediately along the fluid flow path between the intake valve and the fluid reservoir, there are provided in parallel a non return valve which allows substantially free flow of fluid from the fluid reservoir to the intake valve but not substantially in the reverse direction, and a means for allowing flow of fluid from the intake valve to the fluid reservoir with a relatively high flow resistance being presented to the flow. Thereby, the stroke of the piston member has a much reduced inactive initial stroke portion, as compared with other portless type master cylinder devices, and the operational feeling of the master cylinder device is greatly improved.