Two-way check valve

Claim 1

A two-way valve for a brake master cylinder or the like, which cylInder has a port and a valve seat surrounding and facing axially inwardly from said port, said check valve comprising a rigid disc having at least one aperture spaced radially outwardly from its center but radially inwardly from its periphery, an elastomeric diaphragm member having an axially outwardly facing annular portion adapted to engage said seat in sealed relationship and also having an axially inwardly facing annular portion, the radially outer surface of said axially inwardly facing annular portion having a plurality of radially spaced radially outwardly projecting surfaces to act as guides and to permit fluid flow from said port and around said diaphragm between said axially inwardly and outwardly facing annular portions, said diaphragm also being provided with a web extending transversely of its axially outwardly facing annular portion adjacent said disc, the said web having a central opening defined by an axially inwardly facing annular bead which normally engages said disc in sealed relationship radially inwardly of the disc aperture whereby to provide a space between the disc and diaphragm web, said web remaining in sealed relationship with said disc except when pushed axially outwardly by fluid flowing through said disc aperture and out of said port, and a spring means engaging the axially inwardly facing surface of said disc between its periphery and its aperture to urge said diaphragm toward engagement with said valve seat, the radially inner surface of the axially inwardly facing annular portion of said diaphragm having at least one preformed finger to retain said spring means in engagement with said disc whereby the diaphragm can be moved from engagement with said seat as a result of fluid pressure exerted axially inwardly from said port to permit flow around said diaphragm.