GB669678A - Improvements in or relating to the deep-drawing of sheet metal - Google Patents

Abstract

669,678. Cupping. RHODES, C. J. Nov. 18, 1949, No. 29627/49. Class 83 (iv). In a deep-drawing press, the sheet blank is gripped between a draw-ring and a hollow die with a constant pressure whilst it is drawn into the die by a plunger. A ram head 1 carries the die 2 which, in the idle position, is spaced from the drawring 8 to allow the insertion of a blank therebetween, the end of the plunger 9 also being flush with the draw-ring. After a predetermined travel of the head 1 to the left in the Figure, adjustable links 36 pivoted at 35 to the head, ride by means of ramps 47 under stationary rollers 48 to cause dogs 44 thereon to engage recesses 30 in rack bars 25 pivoted at 26 to a slidable plate 12. When the die 2 isspaced from the drawring 8 by the thickness of the blank, the dogs 44 engage shoulders 45 on the bars 25 so that the ring and die travel together at a constant distance apart. As soon as the rack-bars 25 begin to move, they rotate pinions 18 engaging a rack 14 on the plunger 9, which is thereby forced into the die 2 to draw the blank past a die-ring 2c and a reducing-ring 2d. On reversal of the head 1 the plunger 9 withdraws and the open end of the neck engages a stripper ring 2e in the die, and when the plunger is completely withdrawn the work falls out of a window in the side of the die 2. When the rams 47 ride off the rollers 48, the draw-ring 8 remains stationary to allow the die 2 to recede therefrom and the remainder of the withdrawal of the ram 9 is effected by springs 41. The die 2 may contain more than one reducing-ring 2d.