GB359651A - Improvements in or relating to valve stems for tyre valves and the like - Google Patents

Abstract

359,651. Leak-tight seals. SCHRADER'S SON, Inc., A., 470, Vanderbilt Avenue, Brooklyn, New York, U.S.A.- (Assignees of Clo, J. H. ; 21, Lakeside Drive, Baldwin, New York, U.S.A.) Sept. 16, 1930, No. 27661. Convention date, July 3. (Class 99 (i).] A two-part valve stem for a tyre valve comprising a short tubular base adapted to be attached to the inner tube and adapted to receive alternative tubular upper parts adapted to house the valve insides, is provided with means to give a multiple leak-tight seal between the two members. In the form shown in the Figure the base part B is screwed threaded internally and is bored out to provide a square shoulder at b<9> and an inclined shoulder at b<7>. The bore above the shoulder b<7> is made square in cross section and is axially slotted at the corners, the slots extending into the inclined shoulder. A tubular member b<11> having a tapered surface b<12> and constructed of harder metal than the upper part of the stem is driven or soldered in the bore b<8>. In a modification the tapered member is formed integrally with the base. The upper part C has a flange c<8> engaged by flanges d, d<1> on the coupling- nut D, a slightly tapered squared part c, and a recessed extension c<1>. A rubber packing is cured in the groove c<2> and is adapted to seat on the inclined shoulder and also enter the bore b<8>. The wall at the bottom of the groove is made relatively thin so that when the end of the extension c<1> engages the plug b<11> it is deformed to make a fluidtight seal between the extension c<1> and the bore b<8> as well as between the extension and the plug. In a modification the external thread in the base part is tapered and the nut correspondingly shaped to facilitate the forcing of the parts of the square bore against the square shank. The end of the part c<1> may also be formed with a series of contacting edges where it engages the plug.