GB1157053A - Punch Assembly for Perforating Materials - Google Patents

Abstract

1,157,053. Punches and dies. H. W. HENN. 2 March, 1967 [2 March, 1966], No. 10030/67. Heading B3W. A multiple perforating punch for making a series of laterally and longitudinally spaced holes simultaneously, comprises a back-up plate adapted to be mounted in a punch press, spaced dovetail key means secured on the under surface of the plate and adjustable towards and away from the plate, a series of paired punches the upper end of each of which has a half key slot for detachably securing it on the dovetail keys and the under surface of the plate, each of the punches being adapted to be individually removed from the keys, spacers having ribs to space a pair of the punches laterally astride the ribs along the key and other pairs of punches adjacent and longitudinally of the key, spaced longitudinally by the spacers which have a dovetail keyway for securing the spacers to the key and the under surface of the plate; and removable end caps to secure the punches from longitudinal movement along the key and to fix the position of the punches on the key. The back-up plate 1 has parallel slots 2 which receive dovetail keys 3 which are drawn into the slots by screws 38. If there is an odd number of rows of punches then one of the keys 20 has only a half dovetail. The punches are arranged in pairs on the keys, each punch having a halfdovetail keyway and a clearance 14. The punches of each pair are spaced apart by the tongue 6 of a T-shaped spacer. The head 5 of each spacer is between adjacent pairs of punches. Keeper blocks 10 extend across the back-up plate between adjacent keys and force the punches against the key. Movement of the punches along the key is prevented by end caps 15. The keeper blocks and end caps are aligned on the back-up plate by square-section keys 17. Between the end caps 15 are side caps 18, aligned by square keys 19. By removing the side cap 18 a punch can be removed from an outer row, and by removing the appropriate keeper block 10 a single punch can be removed from an inner row or from an outer row such as that shown at the right-hand side of Fig. 2. The die consists of a back-up plate (28), Fig. 6 (not shown), with slug discharge openings (29). Die members 30, Fig. 13, machined to suit the punches are secured to the back-up plate (28). When the die cavity is irregular in shape there may be ribs (37), Fig. 16 (not shown), on both sides of the body portion 31.