| 摘要 |
1. Electrical welding sleeve (12), in which is inserted a cylindrical heating envelope (1, 2) of thermoplastic material, which envelope comprises a bobbin of resistant metallic wire (1) in its calibrated interior orifice, the ends of which bobbin are fixed to terminals or bushes ensuring a good contact with a generator, the resistant wire (1), completely enveloped in the thermoplastic material, is close to the surface of the sleeve (12), and covered by an extra thin thermoplastic film (2), characterized in that a generatrix of the cylindrical resistant wire is in contact with the interior surface of the envelope (1, 2) and that a security space (b, c) is located in the interior of the said envelope (1, 2) at each end of the bobbin (a) of the resistant wire (1), the said space (b, c) being at least equal to 30% of the length of the bobbin. |
