GB556256A - Improvements in methods and apparatus for the application and utilization of fluid pressure - Google Patents

Abstract

556,256. Pipe joints. MITCHELL, R. J., and HAYES, C. W. March 17, 1942, No. 9147. Divided out of 556,010. [Class 99 (i)] [Also in Group XXVI] A pipe joint is formed by surrounding one or both pipes with a distensible envelope, so confined that its expansion will force a wedge-like or deformable sealing-ring or rings axially between the pipes or between one or both pipes and a surrounding collar and then distending the envelope by fluid pressure to form or complete the joint. In one form, Fig. 1, a wedge ring 12 of soft metal or other plastic material is forced between the pipe ends 10, 11 and a surrounding collar 13 by a distensible hollow ring x carried by a removable appliance 14. The latter consists of a casing or housing 14, 14a longitudinally or otherwise divided into portions hinged or pivoted to allow them to be placed around the joint with a flange 14b of the housing bearing against the collar 13. A slide ring 15 within the housing bears against the wedge ring 12 and forces it axially into place when the ring x is distended by fluid injected through a tubular stem 16. The fluid is supplied from a hydraulic main, pump, oil gun or gas cylinder and may be a solid or semi-solid material such as soap or grease. In constructions (described below) in which the envelope is left in situ, the fluid may consist of Portland cement, pitch, gels or other substances which will set after injection. In modifications, (a) an appliance similar to that of Fig. 1 is used to force a wedge ring into a spigot-and-socket joint ; (b) to assist in retaining the butt ends of pipes in contact during the insertion of the wedge ring, a split ring 18, Fig. 3, has enlarged ends 18a fitting in annular recesses in the pipe ends 10, 11 ; the ring 18 may be smeared with a sealing material such as rubber solution, plastic varnish, tar, or liquid pitch; (c) a collar such as 13, Fig. 3, co-operates with two wedge rings forced in from opposite sides; Fig. 4 shows a spigot joint in which the envelope x is left in situ; in Fig. 6, the collar 14 is in two halves bolted together and two wedge rings 12 are forced in by the envelope x and rings 15 ; in Fig. 7 a removable appliance 14 similar to that of Fig. 1 is used to force a ring 23 of lead or soft alloy between the pipe ends 10, 11 and a collar 13 ; the ring 23 is formed with a spacer flange 23a engaging between the pipe ends and the pipe ends and the collar may be formed with tapered grooves 24, grooves 23b, or otherwise grooved, dimpled, tapered or formed to provide a key for the ring 23.