US Patent 7261525 Outlet check valve for fluid bladders

A manually operated pump having a pump assembly and a check valve. The pump assembly includes a dome with a fluid inlet. A support plate is sealed to the dome to define a fluid chamber. The support plate includes a fluid outlet. A foam material is positioned in the fluid chamber, the foam material expanding the dome to a rest state upon release of external pressure on the dome. The check valve has a valve inlet in fluid communication with the fluid outlet of the support plate. The check valve is positioned outside of the fluid chamber. The check valve has at least one exhaust channel to provide one way fluid flow from the fluid chamber through the exhaust channel.