| 摘要 |
<p>A sleeve shaped weld connecting piece (1) of thermoplastic material for connecting thermoplastic pipes (2) by means of a weld connection. The connecting piece comprises a heating element (4) embedded near the inside wall (3) and bearing connecting parts (9, 9a) accommodated in chambers (10, 10a). A pin shaped weld indicator element (7, 7') extending to the region of the heating element (4) is disposed in a bore (5) in the wall (6) of said connecting piece. The indicator element is provided with additional means (15, 18, 19, 20, 21, 27 and 27') enhancing the visibility of a welding action through heating element (4) at the outer side of the connecting piece, said additional means being activated by heat generated during welding. The pin shaped element (7) may consist of a metal pin (7) extending from the vicinity of the heating element (4) to the vicinity of the outer wall of the connecting piece, said pin shaped element (7) bearing at the upper side a sticker (27, 27') of colour changeable material, changing its colour under influence of heat generated during welding.</p> |
