| 摘要 |
<p>Electrically heated thermoplastic welding sleeve for joining thermoplastic tubes by heating the sleeve by means of a heater coil within said sleeve of which the wire terminals are fed through the wall of the sleeve for connection to a power supply. For centering tubes of unequal diameters, due to manufacturing tolerances, the inside wall of the sleeve is provided with resilient protrusions. The method for manufacturing said protrusions is characterized by cutting the inside wall longitudinally so that the displaced material from the grooves forms fins.</p> |
