Spray pump

Claim 1

A spray pump for liquid in a reservoir, of the type having a pump cylinder defining a pump chamber, a piston movable in the chamber to develop fluid pressure, an actuating pushbutton arranged to move the piston axially in the chamber, an atomization nozzle arranged to receive the liquid from the chamber, and a liquid outlet valve located between the pump chamber and the atomization nozzle, the spray pump adapted to force liquid along a flowpath from the pump chamber to the nozzle when the piston moves in a first direction and to draw liquid from the reservoir into the chamber when the piston moves in a second, opposite direction, the outlet valve comprising: a valve body having an arcuate circumferential sealing surface; a tubular member defining at least a part of the flowpath and having a resilient portion of substantially uniform cross-section for receiving the valve body, the resilient portion being radially deformed into a bulge, along its length, by the arcuate circumferential sealing surface of the valve body, the resilient portion thereby having an inner counter-sealing surface of arcuate form, the sealing and counter-sealing surfaces closing the flowpath when the piston moves in the second direction, the bulge of the resilient portion being further radially deformed and enlarged, along its length, by fluid pressure when the piston moves in the first direction, separating the sealing and counter-sealing surfaces, and opening the flowpath; and, a stop for holding the valve body against axial movement in the tubular member during movement of the piston in the first direction.