| 摘要 |
921,901. Pipe joints. TELEGRAPH CONSTRUCTION & MAINTENANCE CO. Ltd. July 1, 1959 [July 7, 1958], No. 21745/58. Class 99(1). [Also in Groups V and XXXVI]. Articles such as rods or tubes of thermoplastic material, in particular polyethylene, or electric cables insulated or sheathed with such material, are joined or repaired by enclosing a part of each article in a mould chamber having inlet and outlet ports, injecting thermoplastic material into the mould chamber by connecting the inlet port to a source of supply, and when the chamber is full and after disconnection from the injection supply, sealing the chamber and compensating for any contraction of the thermoplastic material on cooling by reducing the volume of the sealed space. The apparatus shown in Fig. 1 for the jointing or repair of cables comprises a two-part mould 3 of transparent plastic into the ends of which the cables 1, 2 are inserted and which has an inlet port 6 and spew holes 7. Molten polyethylene is injected into the port 6 until the mould cavity 18 is completely filled and then the plunger assembly 12 comprising the nozzle 17<SP>1</SP>, plunger 16, and plunger head 29, is clamped in position and the plunger screwed downwards to set up a gradual increase in pressure in the molten polyethylene. The polyethylene is then allowed to solidify and should any contraction voids be seen to form, the plunger is further screwed down until they are eliminated. Similar apparatus for jointing cables having a number of cores, e.g. telecommunication cables, and for moulding pipe joints are described. Apparatus for repairing the outer sheath of a cable when it is not necessary to mould into position a complete ring of material is shown in Fig. 5. The mould block 50 is formed with an arcuate face 51 conforming to the curvature of the outer sheath and having a transverse groove or recess 52 from which extends a feed duct 53. Four spew holes 61 are provided, two at each end of the mould recess. Screw threaded holes 62 are provided in the mould block 50 to enable the base plate of a plunger assembly to be attached as shown in Fig. 1. Specifications 676,543 and 856,040 are referred to. |
