Abstract: A compression belling machine for precision belling simultaneously of a plurality of plastic pipe ends. This is accomplished by selectively feeding groups of pipes, the ends of which are to be belled, first into a heating unit and then, transferring them by an endless conveyor, simultaneously into a belling station having a plurality of molds one-half of each of which molds is stationary and the other half of which may be moved apart from its mating half to permit insertion between the separated halves of a heated end of one pipe. Each of the molds is entirely separate from the other molds and each mold may be removed from the apparatus for replacement. All mold halves, however, are moved together by a common hydraulic head. Control means are provided to operate a novel sequential type feeder and so that pipes may be selectively deposited into the heater and then aligned with their ends properly inserted into the particular mold cavities.

Abstract: Plastic pipe is belled under pressure by inserting what is, in effect, a telescoping mandrel into a heat-softened pipe end with great axial force immediately after two mold halves with cavities defining the desired bell configurations have been brought together under pressure. The softened pipe end is not only expanded to a bell configuration by the mandrel, but is compressed by the radial annular end wall of a sleeve which slides axially over the mandrel into the spacing between the mandrel and the mold halves defining the bell-shaped cavity. Thereby, not only may the heat-softened pipe end be molded to assume an exact configuration to a high degree of tolerance, but the normal thinning of the walls of the pipe end which occurs with its belling may be re-thickened by the axial compression of the sleeve to the original pipe wall thickness.

Abstract: A multiple station plastic pipe belling machine in which an endless conveyor periodically receives one of a series of plastic pipes as each pipe is dumped from a V-trough receiving such pipes in sequence after their extrusion and cutting into predetermined pipe lengths, disposes the pipes so received parallel to, but spaced from, each other and advances the thus-disposed pipes in predetermined increments; positions the pipes in such a manner that their ends to be belled are first passed in such increments through a heater adjacent the edge of the endless conveyor, while the pipes are continuously rotated until each pipe passes out of the heater and is then carried in such increments by the endless conveyor into the first of a plurality of belling stations where a pair of semi-circular clamps encircle the pipe end and a mandrel or plug is inserted therein.