GB499703A - Improvements in or relating to plug cocks - Google Patents

Abstract

499,703. Plug cocks ; lubricating. HERVIEU, H. R. May 4, 1938, No. 13275. Convention date, Nov. 8, 1937. [Class 135] [Also in Group XXXIV] A lubricated plug cock is provided with an additional cylindrical stem i at the end opposite the usual operating stem g, the shoulders formed by the stems being such that the lubricant pressure acting on them partly balances the plug b axially. The two lubricant chambers n, o formed adjacent the shoulders are in communication by means of two diametrally opposed longitudinal channels p in the plug casing a which in the closed position of the cock connect with U-shaped channels formed in the plug surface so as to surround the ends of the through passage c with a frame of lubricant channels. Each U-shaped channel comprises a vertical groove q joined by two arcuate grooves r, r and in the open position of the cock is cut off from the lubricant supply pressure so that lubricant in the parts exposed at the casing ports e, f is not projected into the controlled stream of fluid. Each stem g, i has sealing grooves j. The upper stem g and if desired the lower stem i also passes through a gland h. The axial position of the plug is adjustable by a screw m. A safety device for cutting off the lubricant channels from the exterior when the lubricant is exhausted or when re-charging with lubricant comprises a spring-pressed piston s bearing a needle or other valve s<1> which closes the passage v<1> when the pressure in the reservoir v falls or the filling screw x<1> is removed. The piston carries also an indicating tail s<2> which projects to the exterior. The safety device may be designed as a separate fitting adapted to be connected to the grooves p or to either of the chambers n, o and its piston may have the filling screw mounted axially therein.