Damping and auxiliary pumping apparatus

Claim 1

A fluid pump having damping and auxiliary pumping apparatus associated therewith comprising: a. a pulsating fluid pump defining an inlet and an outlet and a fluid path between said inlet and outlet, said inlet having means for connection to a predetermined fluid source; b. a delivery conduit connected to said outlet; c. a housing defining a cavity therein; d. a flexible diaphram mounted within said housing so as to separate the cavity into first and second chambers; e. a port in said housing in communication with said first chamber and connected in communication with the fluid path to said pump; f. fluid inlet and outlet ports in said housing in communication with said second chamber; g. a first check valve connected to said inlet port for allowing fluid to flow only into said inlet port, and a second check valve connected to said outlet port for allowing fluid to flow only outwardly of said outlet port; h. inlet and outlet conductors connected to said first and second check valves respectively and having outer ends for connection to a second source of fluid; i. a variable valve in said outlet conductor; j. a second delivery conduit having one end in communication with said first mentioned delivery conduit and an opposite end in communication with said outlet conductor between said variable valve and said second check valve; k. and a second variable valve in said second delivery conduit, said variable valves being operative to control damping flow of fluid between said second chamber and said second source and selectively to control flow of fluid from said second source and second chamber through said second delivery conduit to said first mentioned delivery conduit.