Patent ID: 7207349

Claim:
A hydraulic flow switch comprising: a reservoir body having an opening to permit flow there through from inside said reservoir body to outside said reservoir body; a valve body having a valve head and a valve stem, said valve stem being disposed within said opening and longitudinally slidable therein to facilitate displacement of said valve head between an open position to permit fluid flow through said opening and a closed position to substantially prohibit fluid flow through said opening, said valve head being positioned in an unconfined area of said reservoir relative to an area of said valve head; a biasing member connected to said valve body and applying a biasing force to said valve body to bias said valve body in said open position, wherein said area of said valve head is substantially larger than a passable area through said opening such that, when a pressure differential between said inside of said reservoir body and said outside said reservoir body is insufficient to overcome said biasing force, fluid flow across said valve induces a significantly increased pressure gradient across said valve head to overcome said biasing force and cause said valve head to move to said closed position and wherein said opening is substantially circular having a first diameter, said valve head being substantially circular and having a second diameter at least five times that of said first diameter.