GB965735A - Draw carriage - Google Patents

Abstract

965,735. Drawing tongs and grippers. CERRO CORPORATION. March 14, 1963, No. 10240/63. Heading B3P. Drawing tongs for a tube-drawing machine comprise a body having a plurality of pairs of spaced rearwardly divergent guide surfaces, a guide element between each pair of guide surfaces having guide surfaces parallel with adjacent guide surfaces of said body, defining spaces in which move gripper bits adapted for pulling tubes to be drawn, and means for moving the gripper bits to a tube gripping position, said means comprising rods having dovetail-shaped forward extensions providing divergent side walls, support members having dovetail-shaped rearward extensions which abut said forward extensions in which position the side walls of the extensions are flush, pins on which the gripper bits are pivoted secured to said support members, said extensions being maintained in abutment with each other by extension coil springs secured to the side walls of the extensions. The body 43 has guide elements 47, 48 which provide three pairs of spaced guide surfaces 49 and 50. Between the surfaces 49 and 50 are guide elements 57 defining spaces in which slide gripper bits 51 having jaws 52. The bits 51 are freely mounted on pins 60, and pivotally mounted on each pin is a support member 61 which has a dovetail-shaped rearward extension 62. Each pair of gripper bits is moved by a pneumatic cylinder 71, the piston-rod of which carries a dovetail-shaped piece 66 which is held against the extension 62 by springs 69. Each cylinder 71 contains a spring which biases the piston 72 to the rearward position. Above and to the rear of each pair of gripper bits is a cylinder assembly 89 containing a piston 91 and a compression spring 92. At the end of the drawing stroke the tubes run forward through the grippers, up ramps 59, 83, 88, and strike the pistons 91 which in moving rearwardly compress the springs 92 and absorb the momentum of the tubes. The body 43 is mounted in a carriage which also supports a hook 29 adapted to engage an endless chain by which the carriage is drawn along. The hook is moved into engagement with the chain by a pneumatic cylinder 33 and in so moving compresses a spring which withdraws the hook when the drawing tension is relieved as the tubes leave the dies.