An electrical fusion heater for heating the abutting ends of two plastic pipes to be joined in a plastic pipe fusion apparatus. The heater comprises a thick circular slab of good heat conductivity metal with an outer diameter greater than the diameter of the largest pipe size to be heated, and with a central opening smaller than the smallest pipe size to be heated. A plurality of heater elements are inserted into a corresponding plurality of radial openings along the central plane of the heater plate. A thermostatic switch is inserted into another opening in the central plane and connections between the power cable, the heater elements and the switch are made up in the central opening.
A fluid conduit containment system includes an inner carrier conduit of a first type of resinous thermoplastic material having a first heat weldable annular end face and an outer safety containment conduit formed of a second type of heat weldable, resinous thermoplastic material aligned coaxially in outwardly surrounding, radially spaced apart relation with the inner conduit for containing any fluid leakage therefrom. The second conduit has a second heat weldable annular end face in concentric coplanar relation with the first heat weldable end face and an anchor-spacer extends between the inner and outer conduits for maintaining the conduits in permanently spaced apart relation. The anchor-spacer includes a pair of coaxially aligned spacer rings or halves joining a circumferential outside surface on the inner carrier conduit and extending radially outwardly thereof to engage a circumferential inside surface on the outer containment conduit. The ring halves include annular confronting weld faces adapted to be heat welded together between the inner and outer conduits for securing the conduits against relative radial and axial displacement wherever an anchor-spacer is provided in the system.
The invention relates to a heater for an electric central buffer coupling in which at least one heating element (3) is placed in a recess of the coupling head (1) and is covered toward the outside. To improve the transfer of heat from the heating element (3) into the coupling head (1) and to reduce the expense of assembling and dismantling the heating element (3), the recess is precision fitted to the diameter of the heating element (3) and the recess is constructed in such a way that after completion of the recess the heating element (3), including its seal to the front side, can be introduced into the recess and is to be removably affixed to the coupling head (1).
An indexer system for a plastic pipe butt-fusion machine of the type having a machine super-structure, parallel horizontal support shafts affixed to the super-structure, a first clamp system for removably grasping an end portion of a first length of plastic pipe, a second clamp system for removably grasping an end portion of a second length of plastic pipe and an actuator system for moving the plastic pipes toward and away from each other, the indexing system having an indexer shaft mounted on the super-structure spaced from and parallel to the support shafts, an indexer carriage slidable on the indexer shaft, a facer and a heater pivotally secured to the indexer carriage, a translation mechanism for laterally positioning the indexer carriage to thereby locate the facer and heater between lengths of plastic pipe and a structural beam secured to the super-structure and parallel to the indexer shaft, the indexer carriage being slidably secured to the structural beam so that it is retained in predetermined orientation relative to the horizontal support shafts.
