Patent attributes
A center valve for a master cylinder includes a valve body and a valve seat fitted in a valve casing. The valve seat has an elastic tube fitted on a core member. The elastic tube has a front end portion adapted to be pressed against the rear end face of the valve body, and a rear cylindrical portion. A gap is provided behind the cylindrical portion of the elastic tube. When the front end of the elastic tube is deformed, the cylindrical portion of the tube is also deformed in such a way as to fill or protrude into the gap. Because the rear cylindrical portion is also deformed, the degree of deformation of the front end is suppressed. This prevents the front end of the tube from getting trapped between the valve body and the core member of the valve seat and thus getting torn.
