| 摘要 |
<p>1524976 Valved closures E HALTER and E SCHUMACHER 25 Sept 1975 [28 Sept 1974 23 Nov 1974] 39346/75 Heading B8T [Also in Division F2] A vacuum aspirator flask closure member 10 is provided with an inwardly-opening one-way valve 44 and an outwardly-opening one-way valve 28, the former being openable above a predetermined pressure to admit fluid to the flask and latter being openable to permit fluid to be evacuated from the flask to create a vacuum therein, the vacuum once created being- maintained by the valves which are biased to remain closed. In modifications, the outwardlyopening valve may be housed in connecting tube 20, Fig. 4 (not shown) or both valves may be so housed (not shown). The valves as shown essentially comprise spring-loaded balls 30; a variety of alternative outwardly-opening valves are described, Figs. 6-11 (not shown); see Division F2.</p> |
