Manually Operated Pump Comprising an Assembly for Pressurization and Dispensing of Fluid

A manually operated pump for pressurized dispensing of a fluid product, designed to be fastened to the mouth of a container containing said product, said pump comprising:

• a cup-shaped body delimiting a chamber for suction/compression of the product to be dispensed;
• an assembly for pressurization and dispensing of said fluid product, said assembly comprising:
• a hollow elongated stem having an annular fluid-tight piston, mounted on a first end of the stem,
• a spiral spring, one first end of which bears upon a first retention element projecting from the stem at a second end of said stem,
• a second element for retention of the other end of said spring, said retention element having at least one shaped outer portion, constituting an element for resting on the cup-shaped body of said pump,
• said piston being slidable in a fluid-tight way on the outer surface of a cylindrical portion of said first end of the hollow stem, said piston being mobile between a first, closing, position in which it closes in a fluid-tight way, under the thrust of said spring, at least one hole that traverses the thickness of the stem in the proximity of its first end and opens into the cavity of the stem, and in which said piston bears in a fluid-tight way upon a widened end portion of the stem that is fastened to said stem, said widened end portion closing said cavity of the stem at said first end thereof, and at least one second position, in which, by compressing said spring further, the piston is raised away from said at least one hole of the stem and from said widened end portion,
• wherein the ensemble of said stem, spring, piston, and retention element form a unitary assembly that can be coupled to said cup-shaped body of said pump,
• and a member for connection of said unitary assembly to said cup-shaped body;
• said pump being characterized in that the connection member comprises a shaped portion for retention of the collar that projects from the stem, said portion preventing the exit of the stem from the cup-shaped body when said unitary assembly is inserted into the cup-shaped body.