Patent ID: 6239412
Filing Date: 2001-05-29
Classification: B29C

Abstract:
For use in fusing the end of a branch polyolefin pipe to the side wall of a main polyolefin pipe of a specified radius, a heater comprising:a first rigid plate having a convex outer surface defined by 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 rigid plate having a concave outer surface defined by 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; anda heating element of substantially constant thickness disposed in laminar relationship between said first and second rigid plates,said inner surfaces of said plates being contoured so that, with said heating element in laminar relationship therebetween, said lines of origin of said outer surfaces define a common plane.