GB1046971A - Improvements in or relating to piercing tools - Google Patents

Abstract

1,046,971. Sub-press mechanisms. REDMAN TOOLS Ltd. May 20, 1963 [Feb. 19, 1962], No. 6409/62. Heading B3W. A piercing tool comprises a first part adapted to carry a punch, a second part adapted to carry a die and carrier means adapted to carry stripper means releasably secured thereto so that the stripper means is movable with one of the parts relative to the other part at least during part of the punching movement of the said one part. The sub-set includes elongated top and bottom holders 12 and 11 respectively each having slots 13 to receive clamping bolts 14. The bottom holder has a bore 17 in which a die 19 is locked by a key 24 and a pair of screws 29. The top holder has a boss 31 in which a punch 34 is secured by a key 42, and also has four counterbored holes 48 which slidably receive columns 46. Each column has a reduced threaded end 49 on which is a sleeve 50. A plate 54 has four counterbored holes 53, to receive the sleeves 50 which are each locked by two screws 56, and also has a central bore 61 which is enlarged to receive a circular stripper 65, secured by screws 67. Four springs 57 urge the plate 54 away from the top holder 12. The holders are mounted on a bolster set comprising an upper bolster 75, a lower bolster 74 and one or more pairs of guide pillars 76 which slide in bushes 77. The holder 11 is mounted on the bolster by using a template 79 which fits a slot 78 in the bolster and has dowels 80 to position the holder. The top holder 12 is then positioned on the upper bolster by using a setting plug 81, prior to fitting the die 19, punch 34 and the plate 54. Alternatively the punch 34 and die 19 can be used to align the holders 11 and 12 before fitting the plate 54. In a modification the holders are aligned by using a template fitted to each bolster.