| 摘要 |
A heater for use in fusing the end of a branch polyolefin pipe to the side wall of a main polyolefin pipe of specified radius has a first plate with a convex outer surface definable as a surface generated by rotating a first straight line about a first parallel line of origin at a radius equal to the specified radius of the main pipe and a concave inner surface, a second plate with a concave outer surface definable as a surface generated by rotating a second straight line about a second parallel line of origin at a radius equal to the specified radius of the main pipe and a convex inner surface and a heating element of substantially constant thickness disposed in laminar relationship between the first and second plates, the inner surfaces of the plates being contoured so that, with the heating element in laminar relationship therebetween, the lines of origin of the outer surfaces of the plates lie a common plane. A linkage pivotally connected at one end to the fixed base of the machine and pivotally connected at another end to the moving carriage of the machine is cooperable with heater to disengage the heater from the molten branch or main pipe from which the heater does not first disengage as the molten branch pipe is moved away from the molten main pipe. |
