GB842439A - Improvements in or relating to punching apparatus - Google Patents

Abstract

842,439. Selective punching apparatus. INTERNATIONAL COMPUTERS & TABULATORS Ltd. Dec. 18, 1958, No. 40958/58. Class 31 (2). Punching apparatus comprises a plurality of punches each of which is supported for independent lengthwise movement into and out of a die and has corresponding selectively operable means adapted to constrain it against lengthwise movement towards the die while energy is built up in a spring co-operating with the punch, said energy on release of the punch by said means being utilized to move the punch, through material to be punched and into the die. As shown in Fig. 1, the punching apparatus comprises punches 15, arranged in rows and columns, supported by a carrier 8 reciprocable towards and away from a die 1, each punch being surrounded by a compression spring 20 extending between a shoulder 17 on the punch and an abutment plate 21, movable with the carrier, and each punch being fitted at its end with an armature 19 which is associated with a selectively operable stationary electromagnet 26 adapted, when energized, to constrain the punch against lengthwise movement during the initial period of movement of the carrier towards the die thereby to build up energy in the spring 20 which energy on release of the punch, when the electromagnet is de-energized, causes the punch to move with and relative to the carrier to effect movement of the punch through a statistical card or tape to be punched and into the die. A resilient buffer 22 movable with the plate 21 is adapted to absorb surplus energy in the punches. To prevent rotation of the punches about their longitudinal axes, the shoulders 17 are each provided with flat opposite sides which co-operate with guides 25 fixed to a stripper plate 4. The electromagnets for each column of punches are supported by a fixed bar 28. The electromagnets, the ends of which are anchored in a fixed plate 27, are of horse-shoe shape each having one pole of square cross-section and one of oblong rectangular cross-section. The electromagnets are arranged as shown in Fig. 4. The material is fed to the punches by pairs of rollers 6, 7.