Non-throttling manually reciprocated plunger pump for consumer-type

Abstract

There is disclosed a non-throttling, anti-leak, manually reciprocated, plunger pump for attachment to a consumer-type liquid dispensing container to provide drip-free dispensing of liquid therefrom. The pump has a hollow-stemmed skirted plunger which is reciprocable in a pump chamber to draw liquid through an inlet into the chamber from a container, and to discharge it from the chamber to atmosphere through the hollow stem of the plunger. A check valve is positioned in the chamber inlet to allow liquid to enter but prevent its return flow. A differential force-actuated control element is nested in the plunger, for reciprocation therewith but having capability for axial movement independently thereof. The control element includes valve means for blocking discharge through the plunger stem and the valve is normally biased to blocking position. In addition the control element cooperates with a fitment or body insert at the inlet end of the pump chamber to provide telescopingly cooperating cylinder and piston members which are engaged throughout full reciprocal travel of the plunger and control valve. The fitment includes separate passages for venting the cylinder/piston combination to the interior of the container through an aperture in the wall of the pump housing, and for communicating the pump chamber with the fluid inlet and dip tube of the pump housing. The arrangement facilitates quick priming, and good maintenance of prime once established, of the pump.