GB1342586A - Punch tools - Google Patents

Abstract

1342586 Punching; nibbling R A JAMES and W L LLOYD 5 May 1971 [5 May 1970] 21515/70 Heading B3W The frame 11 of a piercing or notching punch has a C-shaped upper portion 12 in the lower limbs 12b of which a punch unit, including a punch 28, a guide bush 25, lifter spring 27 and shipper spring 29, is removably mounted. A packing piece 30 which takes up the clearance between a piston-rod 15 of an hydraulic ram 14 and the punch head can be removed to allow the punch unit to be lifted out between the limbs of the portion 12. The packing piece can be omitted to provide for miss cutting and the punch unit may be mounted in bore 26 in limb 12b without spring 29 for alignment with a die 23 which is located by a ring 22 on the frame base 12c. A tangentially disposed pin (40) and a dowel (42), Fig. 4 (not shown) prevent rotation of a non- circular punch and die. For emergency operation by a press brake 18 the ram can be replaced by a striker pin 17 guided in a bush 16, Fig. 6, which shows a punch 28 with a stepped portion 44 for notching or nibbling. A workpiece and a portion 45 for engaging the die aperture 43 to absorb side thrust. The punch may have a pin (47) slidable in an axial bore in the punch for manual or pneumatic engagement in a pilot bore in a workpiece. The base 12c is located on a table 35 by a dowel 33 and clamped by one or more bolts passing through elongated slots in the frame base 12c or by a clamp 37, Fig. 1. Alternatively magnets (39), Fig. 3 (not shown), may be let into the frame base 12c.