Manual actuated dispensing pump

A dispensing pump of the pressure accumulating type comprising a pump body and means for securing same in fluid tight communication with the opening of a container of flowable product to be dispensed;

• said body including an annular base and a piston affixed to and projecting upwardly therefrom;
• an annular plunger mounted for reciprocation on said piston to therewith define a variable volume pump chamber;
• a plunger spring for urging said plunger upwardly toward a fully raised position above the base;
• said piston and said base having a check valve controlled inlet passage therethrough for establishing communication between said pump chamber and a container of flowable product to be dispensed;
• a plunger head having a downwardly directed blind socket slidably disposed on said annular plunger and therewith defining a variable volume accumulation chamber between said annular plunger and the blind end of said socket, and communicating freely with the pump chamber;
• said plunger head being formed with a discharge passage extending therethrough from said socket to the atmosphere at a location to be opened and closed by relative movement between said plunger head and said plunger in the direction of said reciprocation;
• and means for arresting the upward movement of the plunger head at a predetermined position wherein said spring normally urges the said plunger fully into the said socket to function as a valve for closing said passage.