Dispensing pump having bellows metering chamber

Abstract

This device for dispensing metered amounts of liquid or pasty products comprises, in a hollow body connected to a reservoir filled with the product to be dispensed, a chamber consisting of a bellows forming the delivery and suction member enclosed in a sleeve acting as a guide member to the stem of a control push member; the bellows enclosing in turn a return spring and having at its end adjacent the port connecting the reservoir to the chamber an annular reinforcement surrounding a central, normally closed inlet valve urged to its closed position by another return spring; the stem of the control push member opposite this valve, which stem is hollow and carries a head enclosing another valve for controlling the delivery of product to a dispensing nozzle, this arrangement preventing any back flow of product to the reservoir and dispensing with the conventional rigid piston and seal arrangement to eliminate leakages and extend the useful life of the device.