| 摘要 |
<p>A valve device comprises a vertical, tubular housing 1, a vertical valve member 2 in the housing 1, and a coil-form compression spring 7 encircling the member 2 and urging it upwardly against a valve seat 9 in the housing lower end. The member 2 includes an upper, obturating portion 5 and a lower, closure portion 3 and its internal surface includes an upper annular part which diverges downwardly at a gradually increasing angle away from the location of the obturating portion 5 in the valve closed condition. The internal surface includes a lower annular part 13 converging downwardly at a substantial angle to the housing axis and situated directed radially outwards of the spring 7. Below the seat 9 is an outlet mouth encirculed by a rim 20, the closure part 3 having a bottom lip 19 at such clearance relative to the rim 20 that, shortly before the closure part 3 seals against the seat 9, the rim 20 and the lip 19 act shearingly upon liquid therebetween. The member 2 includes three guiding fins 6 in sliding contact with the internal surface. The seat 9 may consist of moulded-in elastomeric material. <IMAGE></p> |
