Patent ID: 6132188
Filing Date: 2000-10-17
Classification: F04B

Abstract:
A metering pump comprising a pump body (1) defining a cylindrical pump chamber (2) having a longitudinal axis (3) and presenting an admission orifice (4) and a delivery orifice (5) situated at opposite ends thereof, a sleeve (9) of non-magnetic material mounted stationary inside the pump body (1) parallel to the longitudinal axis (3) of the pup chamber (2) and possessing a closed end (10) situated inside the pump body (1), and an open end (11) opening to the outside of the pump body (1), a drive rod (8) extending in the non-magnetic sleeve and fitted with a magnetic element (12) acting through the sleeve (9) to co-operate with a magnetic cage (13) surrounding the non-magnetic sleeve (9), said cage being coupled to a piston (6; 30; 40) extending transversally between the non-magnetic sleeve and the pump body for a sliding reciprocating motion between the admission orifice (4) and the delivery orifice and having a pump orifice (7; 31; 41) passing therethrough, and a valve (17; 32; 42) mounted to move relative to the piston (6; 30; 40) between a position in which it opens the pump orifice (7; 31; 41) and a position in which it closes it.