Improvements in dies for the drawing of bar, tube, rod or strip

摘要

563,820. Drawing-dies. BOLTON & SONS, Ltd., T., and HAYES, G. V. D. April 30, 1943, No. 6818. [Class 83 (iv)] Sectional dies for drawing bar, rod or strip, such as sectioned bars for the production of commutator sections, comprise a number of blocks 2, 5, 8, 10 each having an operative surface 4, 7, &c. of a length greater than the maximum length of the corresponding side of the bar to be drawn, one or more of the blocks engaging with line contact, as at 3, 6, on the operative surface 4, 7 of another block. Alternate blocks have ribs guided in slots at right angles in the holder 1. The blocks are clamped by screws 13 acting through spacers 12. The blocks have one end surface at right angles to the operative surface, whilst the other end surface of one or more of the blocks is bevelled to an angle less than a right angle. Fig. 7 shows a modified shape of blocks. In a further modification, one or more of the blocks may have a stepped operative surface.