Abstract: Pipe coupling for the high-strength coupling of plastic pipe ends, a coupling sleeve having internal sawtooth ridges which mesh with counter profiles on the pipe ends.

Abstract: A coupling device for coupling plastic pipe to metal pipe. A metal connecting piece has one end arranged for connection to a metal pipe, and a stop at the other end. A plastic coupling member around the connecting piece can be welded to the plastic pipe and has an open inner sealing chamber for a sealing ring. A hold-down member screwed on the connecting piece applies direct axial force onto the ring in the sealing chamber and presses the coupling member against the stop at the same time.

Abstract: An apparatus for forming a bell end having a thickened portion on a pipe composed of thermoplastic material, in which an annular shaping space is established between a shaping sleeve and a mandril having an elastic shaping ring, the height of the shaping space increasing along transition portions of the surfaces of the sleeve and the mandril to a region defining a sealing chamber and then decreasing again.

Abstract: Branch connection for a pipe, which connection comprises a saddle-shaped part provided with an internally screw-threaded tubular member integral with said part, and a tee piece provided with a screw thread which engages with the first-mentioned screw thread, a sealing member being disposed between the end of the tee piece nearest to the pipe and the external screw thread on said tee piece.

Abstract: A method of and apparatus for the manufacture of an electrowelding component of synthetic material comprising a resistance element, in which in a first process phase the component is formed and in a second process phase the resistance element is fixed in place, the adhesion between component and element being achieved by heating the element by electrical energy.

Abstract: A method of shaping a bell end on a pipe of thermoplastic material, in which an elastic shaping ring is expanded radially in its operative position during the shaping of the bell end, and removed from the formed bell end by radial contraction. Part of a shaping mandril is moved to create a cavity into which the ring is free to contract.

Abstract: Tapping tee for a main pipe having integral coupling means for coupling to branch pipes made of flexible or relatively inflexible synthetic materials. A branch-receiving socket has a support pipe fitting snugly inside the branch pipe, and an integral sleeve having a part fitting snugly to the branch pipe outside, and a part with an enlarged bore for a sealing means.

Abstract: A bell end on a pipe of thermoplastic material has variable wall thickness in the axial direction, the maximum being where the inner wall acts as a sealing face. The bell end can be formed by upsetting the pipe wall into the cavity between a mandril and a shaping sleeve.

Abstract: A mandril for shaping a bell end on a pipe of thermoplastic material, having an elastic shaping ring which is expanded radially in an operative position during the shaping of the bell end and which can be removed from the bell end by radial contraction. The mandril assembly comprises a plurality of parts which are profiled and slidable with respect to each other such that in the operative position the shaping ring is locked radially and axially, and in the removal position the shaping ring can retreat into a chamber formed between the slidable parts.

Abstract: The present invention relates to a device for shaping a bell end to a tube of a thermoplastic material, the bell end comprising at least one inner surface (widening) having a larger diameter than that of its opening, the latter extending downward to the outer surface of the tube or of the spigot end to be introduced, said device being provided with a cylindrical mandrel, having an outer profile being almost like the inner profile of the bell end to be shaped, said mandrel having from its insert or front end an outer surface with stepwise varying diameter, the transition between adjacent mandrel surfaces of different outer diameter gradually merging under an angle less than 45.degree. with respect to the axis, the front end of said mandrel having an edge portion inclining forwardly and downwardly, the smallest inner diameter of which being smaller than the inner diameter of the tube.