GB1060656A - Improvements in or relating to presses - Google Patents

Abstract

1,060,656. Cutting-out presses. BRITISH UNITED SHOE MACHINERY CO. Ltd. Jan. 8, 1964 [Jan. 9, 1963], No. 954/64. Heading B4B. [Also in Division F2] A cutting press comprises a lower platen 28, to support a cutting block 180, an upper platen 134 with a flat work-engaging surface, means to move the upper platen into and out of opposed relationship with the lower platen, and means 420 actuated by the upper platen on reaching its position opposite the lower platen to effect movement of the upper platen towards the lower platen, so as to effect a cutting stroke. As described, the press may include left and right-hand upper platens, which may be controlled either singly or together by electric and hydraulic circuits and by an electronic circuit described in Specification 1,060,655, and stroke control may be effected by a known type of conductive cutting bed. The upper platen is moved on a platen support 130 horizontally, Fig. 3 (not shown), between a position overlapping the cutting block 180 on the table 28 and its non-overlapping position by applying pressure fluid either to conduit 170 or 173 which are connected to a cylinder 150 having a piston 156 with a rod 158 secured to the forward edge of the upper platen by a fitting 164 and bosses 168. The platen support is mounted on the frame for upward and downward movement, to effect cutting. Rotation of the platen and its horizontal actuating assembly is prevented by connection of the rear corner portions of the platen support plate 130 to a slide member 190 supported between undercut guideways 192 attached by screws 194 to an upright plate 196. A limit switch mechanism, for stroke termination, includes normally closed limit switches 230, Fig. 2, and actuating mechanism including a rod 240, Fig. 3 (not shown), one end of which is screwed to the plate 130 and is supported for sliding movement by a bracket 244. An adjustable collar 248 actuates the switch 230 at a predetermined height of the platen work surface. The cutting stroke of a platen is powered by an hydraulic motor comprising a piston 72, cylinder 80 and piston-rod 60. The left platen motor is controlled by a valve 400, Fig. 5 (not shown), having solenoids 1, 2. Energization of solenoid 1 moves the left platen 134 forward until it engages an actuating roll of a plunger switch 420 which provides a platen forward signal. When solenoid 2 is energized the platen 134 moves rearwards, dynamic braking being provided by oil exhaust from the cylinder 150. When a solenoid 9 is energized, if pressure increases, e.g. due to heavy loading of the right platen, the spool of a valve 430 is moved towards the closing position so that obstruction of fluid flow equalizes pressure in the associated hydraulic lines, thus equalizing pump slip and platen speed. When the valve 430 is open the cylinder 80 is driven down against air pressure until the solenoid 9 is de-energized. The cylinder 80 and platen 134 are moved upwards by exhausting pressure fluid from cylinder 80, when solenoid 3 is energized. Provision is made for movement of the platen to its preset height before the platen starts to move back. The left and right platen return heights and extent of backward movement are determined by the setting of pairs of potentiometers, and the depth of penetration into the cutting pads is determined by further potentiometers. The left and right side platens are operated similarly by duplicate controls, electrical interlocks preventing operation of the unwanted side.