| 摘要 |
<p>The connecting element is an electrically weldable sleeve (1) which has a sleeve body (2) and a heating wire winding (3) with heating elements (4, 5) and terminals (8, 9) for the supply of electrical power. Conduit ends (6, 7) are inserted in the sleeve (1). To weld the sleeve (1) to the conduit ends (6, 7) a fusing zone is generated electrically in the heating elements (4, 5). In order to position the heating wire turns (10) of the heating elements (4, 5) precisely and, during welding, to avoid adversely affecting the welding power by turns of wire that become free in the fusing zone making contact with each other, the resistance heating wire (11) is surrounded with a first envelope (12) of a material which cannot combine with the material of the sleeve body (2), and a second envelope (15), which consists of a material which is identical to or compatible with the material of the sleeve body (2). The cross-section of the second envelope (15) has a straight circumferential part (16) which on the one hand forms the concave inner wall of the sleeve body (2) when producing the sleeve (1), and on the other hand positions the relative location of the resistance wires with respect to the predetermined welding energy output per unit area. <IMAGE></p> |
