摘要 |
Some precompression pumps currently used for spraying a liquid include a non-return valve formed by a gasket (3) held captive between the base of the pump body (1) and a sleeve (2). This non-return valve determines the extent to which the pump chamber (19) is isolated from or put into communication with a supply of liquid, as a function of whether the gasket (3) bears against the base of the pump body (1) or against the sleeve (2), closing a central hole through the pump body or being held off a central hole through the sleeve. In order to make valve operation more reproducible the present valve has the following features: the base of the pump body (1) is in the form of a cup (18) of small slope; the side wall (28) of the sleeve (2) flares from the end (26) of the sleeve (2) and has a local swelling (27), with the side wall (28) being of reduced thickness on either side of the swelling (27 ); and the end (26) of the sleeve (2) includes a tongue (25) and two ribs (2b), the tongue (25) and the ribs (2b) extend from the side wall (28) of the sleeve (2) all they way to its central hole (2a), the tongue (25) is diametrically opposite the swelling (27) and it is thickest adjacent to the central hole (3a), the ribs (2b) are disposed symmetrically about the diameter passing through the swelling (27) and the tongue (25) such that each of them forms an acute angle with the diameter on either side of the swelling (27). |