Check valve with injector

Abstract

A combined check valve and fluid injector includes a valve body with an inlet, outlet and valve seat. A pump chamber is positioned at the outlet side of the valve seat and has a fluid inlet. A hollow piston member moves in the pump chamber and the hollow connection to the valve body. A ball check valve closing the valve seat is provided with a spring loaded valve follower. A hollow actuating rod extends from the valve follower into the hollow piston with a lost motion connection and has openings for discharge of fluid in the valve body. The piston is limited in movement by an adjustable stop member and has a check valve which opens on upward movement. Opening of the valve moves the rod and piston to pump fluid from the pump chamber into the fluid flowing through the valve body. A counter, or the like, may be provided for operation by piston movement for measuring frequency or distance of movement. Certain modifications may direct the fluid outside the chamber rather than into the valve body. Alternatively, a rubber plug sealed to the rod and to a supporting sleeve presses the rod against the valve follower to function as both spring and seal. The measuring device may also be a continuously functioning counter with an external pinion gear rotatable to move the counter; a rack member engages the pinion; and a reduction gear between the pinion and counter permits measuring the extent as well as the frequency of movement of the check valve.