Pump devices for dispensing fluids

Abstract

A spring actuated pump device is mounted on a container for fluids, the device including a pump chamber into which fluid from the container can flow, the spring expanding and forcing a cylinder structure against the fluid in the chamber to pressurize it, in order that opening of a discharge valve will effect spraying of a desired quantity of fluid from the device, a suitable nut being threadedly connected to the cylinder structure to enable such structure to be shifted axially, in response to rotation of the nut relative to the container and cylinder structure, to compress the spring and store additional fluid pressure energy therein. A check valve permits ambient air to enter the container to prevent a vacuum condition from developing therein as fluid is withdrawn therefrom. Moreover, fluid is prevented from dribbling from the discharge valve of the device as the spring nears the end of its expansion range. Additionally, fluid leakage between a piston and supporting housing for the pump, along which the cylinder structure is slidable, is prevented by the action of pressure in the pump chamber forcing the piston more firmly into sealing relation to the housing.