| 摘要 |
1,271,169. Forming pipe couplings. MUELLER CO. 15 Dec., 1970 [16 Dec., 1969], No. 59512/70. Heading B5A. [Also in Division F2] In a pipe joint (see Division F2), which in- cludes a coupling nut 12 and a tubular member 14, Fig. 4, a permanent annular bead 42 having an inwardly projecting lip 44 is formed on the end 38 of a plastics pipe, while the pipe is positioned within the coupling nut, by applying pressure in a radially outward direction, indicated by arrows A, Fig. 4, to the interior circumference of the pipe. The bead 42 loosely traps the pipe in the nut 12. The plastics may be polyethylene, P.V.C., polybutylene or polypropylene. The formation of the annular bead 42 is effected by an apparatus 50, Fig. 5, whose mode of operation is as follows: a mandrel 56 is inserted into the nut 12, Fig. 10, and the apparatus secured to the nut 12 by an externally threaded tubular nut 52. The pipe P is inserted in the nut 12, so that the end 38 of the pipe abuts a flange 64 on the mandrel 56, and is held in this position by suitable clamping means 90. A cam 58, disposed in a slot 70 in the mandrel 56 is fixedly mounted on a shaft 72, and the shaft, extending through an offset bore in the mandrel 56, is connected to a handle 74. When the handle 74 is rotated in one direction, the slot 70 houses the cam member 58 therein, Fig. 9 (not shown). Rotation of the handle 74 in the opposite direction causes the cam 58 to extend radially outwards to engage the interior of the pipe P. Further rotational movement of the handle 74 causes the mandrel 56 and cam 58 to rotate as a unit, with pressure being applied by the cam 58 radially outwardly to the interior of the pipe to upset the same to form the annular bead 42. |
