GB1098031A - A punch - Google Patents

Abstract

1,098,031. Hand perforators. SIDNEY R. LITTLEJOHN & CO. Ltd. May 14, 1965, No. 14362/64. Heading B4B. A hand perforator, for preparation of film in making half tone blocks, comprises a punch block F slidable in a guide E in a base member D, and secured in any one of a number of positions along the guide by a master gauge O, which comprises a bar slotted at P, Fig. 3, Prov., and pivoted at (R) to the block D. As described the block F is secured to the base by a screw G, and each block includes a punch G2 and die H for punching a single hole, the punch being spring urged upwards to permit entry of a film into a throat I in the block. Each block also comprises a pin J to determine the depth to which a film may slide into the throat I, a pointer N secured to the pin co-operating with a scale N1. The gauge O locates the lower extremity of the punch bushes Q which project into the throat I in the block. Use of the gauge determines the distance A, Fig. 1, Prov., between the punched holes and holds the film flat on the block base D. The distance B is determined by a slidable locating stop T. A pivoted punch lever V extends the length of the block and is spring urged upwards against a stop X, and limited in downward movement by an adjustable stop XI. A scale U graduated for different film widths is arranged about a common centre line Z relative to the slots P in the gauge O. In a further embodiment a stop AA, Fig. 1, is slidable and lockable in a dove-tail slot AC and positioned against a scale AB. The lever V includes a flanged bar AG which co-operates with a head AF on each punch to facilitate withdrawal of the punches from the die. Each depth pin AK comprises a cylindrical bar having deep notches AM extending into shallow notches AN formed in one of a pair of flats along the bar. A spring biased plunger AL, Fig. 2, in the block F may project into one of the grooves AM, so that the pin AK is not axially movable. Rotation of the pin locates the plunger in the shallow notch AN to permit withdrawal of the plunger. The pin is then repositioned and the plunger located in the notch AM by rotating the pin through 90 degrees. The depth of projection of the pin is indicated by a scale and pointer AV.