METHOD AND APPARATUS FOR FORMING BENDS IN THERMOPLASTIC PIPE

摘要

The invention provides apparatus and a method for forming a bend in a line ar section of thermoplastic pipe. The apparatus comprises an anvil having a concave working surface which defines an arc of at least the bend angle of the bend to be formed in the pipe section and which is transversely arced at a radius essentially the same as the radius of the pipe, the anvil further including a collar for retaining an end of the pipe section adjacent the working surface. The method of the invention comprises the steps of heating the pipe section to the softening temperature thereof, driving a flexible mandrel of substantially the same internal diameter as the pipe and of at least the same length as the pipe section into the pipe section, loading the pipe section and mandrel onto an anvil having a concave working surface which defines an arc of at least the bend angle of the bend to be formed in the pipe section and which is transversely arced at a radius essentially the same as the radius of the pip e, the anvil further including a collar for retaining an end of the pipe section adjacent the working surface, drawing the end of the pipe section opposite the retained end towar ds the working surface to bring the bulk of the pipe section into contact with the working surface, allowing the pipe section to cool to below the softening temperatur e while held in contact with the working surface and withdrawing the mandrel from the pip e section.