Pump for dispensing a fluid product

Abstract

The invention relates to a pump comprising: a pump body (1) defining a slide shaft (11), an actuating rod (2) that is movable in the pump body (1), a plunger (3) mounted on the actuating rod (2), which slides sealingly in the slide shaft (11) over a plunger stroke, the plunger (3) forming a lower lip (31) and an upper lip (32), a collar (4) fixedly mounted in the pump body (1) and a return spring (5) that urges the plunger (3) against the collar (4) in the rest position, wherein the slide shaft (11) defines a main section (111) and a secondary section (112), the main section (111) having a smaller diameter than the secondary section (111), and wherein the lower lip (31) is constantly in contact with the main section (111) over the plunger stroke while the upper lip (32) is located at the height of the secondary section (112) in the rest position and is in contact with the main section (111) at least at the end of the stroke of the piston, the invention being characterised in that: the upper sealing lip (32) is in contact with the secondary section (112) in the rest position, and the plunger (3), in the rest position, is in sealed contact with the collar (4) only via its sealing upper lip (32).

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