Method and apparatus for the shaping of one of the sealing accommodation of a tube of the tube serving for pipe connections, in particular sleeves tube compounds, in the warmth deformable tubes, preferably made of plastic

摘要

1450821 Forming grooved bell ends on pipes JOHNS-MANVILLE CORP 21 Jan 1974 [23 Oct 1973] 2684/74 Heading B5A [Also in Division F2] An internal groove is formed in the bell end of a PVC pipe by pushing the pipe over a hard rubber sealing gasket projecting from a supporting core so that a groove is formed by the gasket, and then deforming the groove (see Fig. 12) to reduce its extent. The gasket is left in the groove or can be replaced; several gaskets and retaining members can be used. As described, the gasket 26 (Fig. 10) is seated in a recess of a lubricated and heated steel core 54. A plurality of pivoted ramp bars 68 are projected from the core by rods 73 actuated by a frusto-conical surface 71 (Fig. 5). The heated pipe end is pushed over the core, ramp bars and gasket until it meets a stop 56, whereafter the ramp bars are spring retracted flush with the core (Fig. 12) and the pipe end is drawn on to the core by suction and air pressure. A plurality of plungers 90, 104 mounted on an annular support 72 (Fig. 5) are operated by pistons or linkages to deform the pipe groove about the gasket (Fig. 12) to lock the gasket in position. After fluid cooling, the pipe is withdrawn from the core, with the gasket riding up an inclined surface of the core recess. The plungers 90, 104 comprise a plurality of straight edged members 94 (Fig. 7) that form a plurality of opposing or staggered locking projections in the pipe. Alternatively, arcuate plungers form a continuous locking projection adjacent the groove edges or in the body of the groove.