Patent GB-981778-A (GB)
Title: Improvements in or relating to punching machines
IPC: B21D37/04
Filed: 1961-04-07
Abstract: 981,778. Punching. HOUDAILLE INDUSTRIES Inc. April 7, 1961 [Nov. 1, 1960], No. 40291/64. Divided out of 981,775. Heading B3W. A punching machine includes a frame having a bed, a reciprocating ram, an upper tool support secured to the frame for slidably supporting an upper tool in alignment with the ram, a lower tool support mounted on the bed and a horizontally-directed table connected to the frame and encircling, but not connected to, the lower tool support, the table having an upper surface which supports a workpiece so that its lower surface is co-planar with the upper face of the lower tool, and manually actuatable means carried by the bed for effecting relative vertical movement between the lower tool support and the table so as to space the workpiece upwardly from the table. A punching machine including the adjustable table comprises a C-shaped frame 31 having upper and lower arms 31a and 31b respectively. The lower arm 31b supports a sub-table 50 on which is mounted a work supporting table 33, and also supports a bed 38 on which the lower tool is mounted. A punch and stripper assembly 40 is supported by an upper tool support 41 which is held to the upper arm by clamps 42 and 43. The support 41 comprises arms 41a and 41b and between them is a reciprocating shaft 47 continuously driven by an eccentric 46 and selectively coupled to a ram 44 by an electrically operated clutch of the type described in Specification 890,250. The sub-table 50 is provided with two brackets 51, 52 and clamping screws 54 by which it is fixed to the frame. Pads 56, 57, 57 attached to the sub-table 50 support screw-jacks 58 which are connected to the table 33 and which are operated simultaneously by a handle 63 to raise or lower the table. Angular or lateral displacement of the table is prevented by two guide pins 64 which are secured to the table 33 and slide in bushes 67 in the sub-table 50. To facilitate the removal of a workpiece the table can be lowered relative to the die 39 so that the workpiece rests on the die and is spaced from the table 33. Lower tool support, Fig. 5.-The support for the die 39 is secured to the lower arm 31b and includes a pad 69 to which is screwed a bolster 70 having a recess 72 which receives a cylindrical member 73, also held by screws and locked against rotation by a key 87. An element 75 is a sliding fit in the member 73 and of such a length as to define a recess to receive the die 39. Removal of the die is facilitated by a pin 76 which is moved axially by an eccentric 82 formed on a shaft 77 which has a handle 78. Small-sized dies are mounted in the support by a pedestal which has a base of the same size as the cylindrical member 73 and fits the bolster 70 in the same manner. Gauging mechanism.-The work positioning mechanism comprises a rail 172, 173 at each side of the table 33, and includes a rack-like member 174 which is parallel to the rail 172 and is rotatably supported in end bearings. A block 176 slides on each rail and the blocks are connected by a gauge bar assembly 175 which is provided with a number of stops which are slidably adjustably supported thereon. The left-hand slide block 176 supports a device 177 for engaging the rack-like member 174, which in the embodiment described is threaded. A counter mechanism 178 is also mounted on this block. Template follower mechanism.-The gauge bar assembly also supports a template follower 254 which is secured to the right-hand half of the table by a sheet coated on both sides with a pressure sensitive adhesive. Electrical control, Fig. 10.-The machine is controlled by a start switch 266, a stop switch 268 and a selector switch 270 which in one position directs power to a foot switch 271 by which single strokes of the ram are effected and in the second position directs power to a switch 272 which is incorporated in the template follower mechanism and is part of circuit by which continuous reciprocation of the ram is effected.