| 摘要 |
A self-closing closure for a tube or package having a resilient wall for dispensing flowable material upon the application of pressure on the tube, utilizing a relatively stiff disc for supporting an outwardly extending centrally disposed valve stem having a closed outer surface and a diaphragm member having its periphery interconnected with the periphery of the disc to form a closure unit and its inner portion forming a valve with the valve stem. The diaphragm member is formed with a relatively thick flange substantially parallel with the walls of the tube for interconnection therewith, a relatively thin, resilient planar portion extending inwardly toward the stem, and a substantially tubular portion surrounding the stem and terminating in an open lip which makes a close, sliding fit with the outer surface of the stem. The resilient, planar portion of the diaphragm member is normally concave, being formed with an unstressed negative angle of substantially 5.degree. to 15.degree. with a plane perpendicular to the longitudinal axis of the tube. When assembled with the disc, the stem interacts with the lip of the tubular portion of the diaphragm member to reduce the negative angle by about 2.degree. and to form a secure closure in the rest position of the planar portion. When pressure on the tube above a predetermined value is applied, the planar portion of the diaphragm member is forced outwardly by the contents of the tube to a convex shape having a positive angle not to exceed 8.degree., carrying the lip of the tubular portion away from the stem and opening the valve. Upon release of the pressure on the tube, the planar portion of the diaphragm member automatically returns to its rest position having a concave configuration with respect to the flange and the tube and securely closing the tube. |
