GB963997A - Means for sealing relatively movable members - Google Patents

Abstract

963,997. Seals; valves. DAVID F. WISEMAN & SONS Ltd., GESELLSCHAFT DER L. VON ROLL'SCHEN EISENWERKE A.G., and F. E. SWAIN. July 29, 1960 [July 29, 1959 (2)], No. 26611/60. Headings F2B and F2V. A seal for preventing the flow of fluid between two relatively movable members 2, 3, Fig. 1, comprises a sealing element 4 which is formed of an elastic, incompressible material and is mounted in one of the members 2 (as shown), so that its other end makes only slight contact with the other member in the absence of fluid pressure, the arrangement being such that, upon the application of fluid pressure from one side, the element 4 escapes a sufficiently large surface on that side to cause it to act as a toggle linkage 9, Fig. 2, whereby the sealing pressure exerted by the element against the member 3 is of greater magnitude than the applied pressure; the desired toggle action is conditional upon the exposed side face 4b of the element defining an angle α of more than 30 degrees with the member 3 and arranging for the gap between the members 2, 3 to exceed one-third of the width b of the contact end of the element. The side of the element forming the angle α may be flat, concave or convex and, if desired, both side faces may be so formed. The member 3 may be a shaft rotatable in a housing 2 or a butterfly valve pivoted in a conduit 2, in which case the element 4 serves as a seat for the valve in its closed position. If desired, the element may be of rubber, provided with an internal reinforcement or a hollow metal ring filled with a pressurized medium.