Patent GB-1183871-A (GB)
Title: Improvements in or relating to Punch Presses
IPC: B21D28/12
Filed: 1967-02-21
Abstract: 1,183,871. Punching. HOUDAILLE INDUSTRIES Inc. 21 Feb., 1967 [21 Feb., 1966; 6 Feb., 1967], No. 8293/67. Heading B3W. A punch press comprises a base for supporting a workpiece, a frame having a pair of vertically spaced arms, the frame being movably supported by the base for reciprocable, linear, horizontal movement with respect to the workpiece, means disposed between the arms for guiding co-operable tooling for acting vertically against opposite sides of the workpiece, and ram means supported for vertical reciprocation entirely by the base independently of the frame and operative on the tooling. As shown, Fig. 2, a workpiece 18 is fed along a roller table 16 by forming part of a base 15 by means of hydraulically-actuated clamps 40 mounted on a rack 38 reciprocable by means of a pinion (77), Fig. 5 (not shown). The rack is supported by series of individually adjustable rollers (72), (73) in a C-shaped portion of the base. Associated with the pinion are velocity and position indicators. The workpiece may be in the form of strip which is drawn from a roll stand through straightening rolls by the motor driving the pinion (77). A frame 24 comprising upper and lower arms 26, 25 carrying tool turrets 30, 29 respectively is reciprocable transversely of the base passing through openings 48 in uprights 20, 21 integral with the base and bolted to an upper member 22. The frame is reciprocated by a motor 35, Fig. 4, through a rack 58 on the lower arm. Guide rollers 36 are provided on the uprights 20, 21. Conventional velocity and position sensing devices may be provided. In an alternative drive, Fig. 17, two fluid pressure cylinders 87 have a servo control valve arrangement 84, 89 which increases the flow of fluid through either line 90 or 91 according to the direction of movement called for by numerical control means 14. The turrets are rotated by a motor 33, Figs. 2 and 4, through a rack and pinion drive (Fig. 8, not shown). A tool ejector 54 and a tool loader 55 are mounted respectively on turrets 30 and 29 respectively, preferably vertically aligned with each other. The base comprises two sections 67, Fig. 4, connected to a frame-supporting portion 19 by means 68 for squaring the base. A drop down section (70) may be provided, Fig. 16 (not shown), to give access to the tool changing means 54, 55. Slidably mounted in the uprights 20, 21 of the base is a ram 46 driven by eccentrics 61, Fig. 7, through a belt drive 41 from a motor (not shown). The ram carries two heads 47 which pass through and are merely guided by the frame arm 26 and are selectively operable to actuate one of two diametrically opposed tooling stations. The numerical control means 14, Fig. 17 and Fig. 1 (not shown) allow for simultaneous feeding of the workpiece, reciprocation of the frame 24, rotation of the turrets and the selection of which ram 47 is to be operative. A cut off mechanism (12), Fig. 1 (not shown) may be actuated by the means 14 simultaneously with the ram 46. The shaft (104), Fig. 8 (not shown) on which the upper turret 30 rotates carries a code drum (108) and a reading head 109 coacts with coding on the drum to signal the presence of a selected turret station in alignment with a selected one of the ram heads 47. Each head 47 includes an upper and a lower non- rotatable section 122, 123, Fig. 14, variably spaced on a shaft 128 by a rotatable wedge 125, the wedges being rotated by a rack 129 to close up the sections of one head to the idle position while extending those of the other head to the active position. A T-head 132 on each upper section 122 engages in a slot 133 in the ram 46 and is adjustable therealong when the frame 24 is reciprocated. A T-head 134 on the lower section is engageable in a T-slot in the tooling of a turret station. The weight of the ram is supported by conventional air balances 135. A fluid pressure-actuated stripper plunger 139, Fig. 15 (not shown) in the lower section 123 includes fingers (147) extending through peripheral openings in a plate (142) carrying the T-head 134 and engageable with stripper pins (149) on the tooling. For small tooling the pins may engage captive plugs (148) also extending through the plate (142). A series of fingers and plugs for coaction with different sizes of tool are provided. One or more keyways (152), Fig. 9 (not shown), may be provided at the tool stations and may be carried in angularly adjustable bushings (153). To support dies which are smaller than the slug shoots (102), Fig. 8 (not shown) a movable bolster 154, Fig. 11, inserted between a die-locating dial (157) and the lower arm is provided with apertures 160 corresponding to the slug shoot openings and one or two smaller apertures 161, 162 corresponding to smaller die sizes. The bolster may be positioned by hand or by an actuator 163 which may be controlled by a switch on the reading head 109 in dependence on the angular position of the turret. To allow the bolster to be programmed to move independently of the turret position the numerical control 14 may include digital code means and a sensing head responsive to the code means for controlling the actuator. In an alternative form of movable bolster, Figs. 16 and 18-21 (not shown) two actuators are provided for rotating the bolster which has two sets of three differently-sized apertures and three peripheral slots spaced angularly by the angular spacing of the apertures in which binary code means are positioned at a selected height to coact with one of group of control switches.