Continuous extrusion machine and method of continuous extrusion

摘要

A method, apparatus and process for forming an elongated product of unlimited length is disclosed. The method consists of gripping and feeding a material of unlimited length between two toruses whose toroidal surfaces have suitable shaped grooves to accommodate the incoming material. The toruses are so constructed that each of them can sustain a radial deformation substantially in excess of 0.2 per cent without undergoing a permanent plastic set. The toroidal surfaces of the two toruses are radially squeezed against each other so as to cause a temporary radial deformation in both toruses substantially in excess of 0.2 per cent but less than an amount that causes a permanent set in either torus. This creates a contact length between the two toruses. Such squeezing also causes a three dimensional stress distribution in the grooves which stress is substantially hydrostatic. A deformation control element with a suitably shaped aperture or apertures is located substantially in the center of the length of contact. The incoming material is gripped between the two toroidal surfaces and is pushed into the die by rotating the two toruses together so that the toroidal surfaces in contact move linearly at substantially identical velocities and so that there is substantially no slippage between the toroidal contact surfaces and the incoming rod and such that there is substantially no upset or work hardening in the incoming material before it enters the die. In the deformation control element, which is the die, the incoming material undergoes suitable deformation. The product exiting from the die is of unlimited length and is of a shape and size which is determined by the shape and size of the orifice or orifices in the die.