Patent ID: 6196424
Filing Date: 2001-03-06
Classification: B05B

Abstract:
Pump of the type comprising a substantially cylindrical body (1) internally defining a metering chamber (11) of which the lower end (1a) is provided with an intake orifice (10) equipped with a valve (12) and whose upper end is provided, on the one hand, with an outlet orifice and is, on the other hand, closed by a piston (2) capable of moving in said chamber (11), by cooperating with elastic return means (4) outside the chamber (11), between a support up stop and an end-of-stroke down stop, said piston (2) comprising a central core (21) fast with the lower end (23a) of an axial hollow rod (23) whose upper end (23b) projects outside the metering chamber (11) and a coaxial sleeve (22), connected to said rod (23) by an elastic articulation (24) ensuring, on the one hand, a sealed contact with the inner wall of the chamber (11) and defining, on the other hand, with said core (21), an annular evacuating conduit (20) capable of being opened by displacement of said sleeeve (22) relatively to the core (21), and the upper part of the pump body (1) being closed by a flange (3) of which the inner face, on the one hand, forms the up stop of the piston (2) and the outer face, on the other hand, serves as bottom support for the return means (4); said flange (3) being provided with an axial bore (30) in which the hollow rod (23) fast with the piston moves, characterized in that said sleeve (22) comprises an upper ring (22b) intended to come into sealed engagement in a peripheral groove (31) made on the inner face of said flange (3).