Patent GB-1136293-A (GB)
Title: Improvements in or relating to impeller devices for implements
Inventor: FRANEK JOZEF TADEUSZ
IPC: B21J7/12
Filed: 1966-05-25
Abstract: 1,136,293. Mechanical presses. METAL BOX CO. Ltd. 21 April, 1967 [25 April, 1966]' No. 23373/66. Heading B5F. [Also in Divisions B3 and F2] A device for impelling at a high velocity an implement, such as a hammer, a stamping, blanking, embossing, scoring, forming, or impact extrusion tool, comprises a flexure strip 1 which is deflected within its elastic limit by applying pressure to the opposite ends of the strip, e.g. as shown in Fig. 1, by pairs of spring discs 10 each pair of which is interposed between a side frame member 5 and an adjustment nut 13 on a tie bolt 6, and actuating mechanism to cock the strip by reversing the direction of deflection and to trigger the cocked strip by applying thereto a force operable to cause the strip rapidly to assume the uncocked condition to impel, at a high velocity, an implement associated with the strip substantially mid-way between its ends. As shown in Fig. 1, a tool 7, 8 carried by two flexure strips 1, 1 mounted in the side frame members 5, which are flexibly supported on a base 3 by deformable strips 4, co-operates with a tool 2 carried by the base 3 the nuts 13 being turned until the springs 10 apply a force to the ends of the strips 1 exceeding, e.g. by two or three times, the value given by Euler's formula. The arrangement of Fig. 1 does not include cooking and triggering mechanism, the stem 8 of the tool 7, 8 having a slot 14 which unobstructively receives the tie rod 6 and which has a stop 15, which provides sufficient reverse deflection, in the cocked position, to prevent accidental triggering from externally applied shocks. In a practical embodiment, Fig. 4, e.g. for scoring a can end 26 fed into and removed from the tool 2 during the cocking of the strip, each strip 1 comprises four laminations and the cooking and triggering mechanism consists of a rotary shaft 17 secured to a flywheel, not shown, and carrying an eccentric 19 which co-operates with a strap 20 having a pin 21 located in slots 22 in guide plates 23 secured to the stem 8. In a balanced arrangement the drive is duplicated one device being located at each side of a common base 3. In a 400 ton press, Fig. 9, not shown, for the extrusion of aluminium or aluminium alloys the tools (7) and (2) respectively comprise a plunger and die. In a further-device for high speed tools, or for the acceleration of missiles, Fig. 10, the stems of a vertical pair of devices are connected to the ends of transverse flexure strips 31, which carry the tool or missile 7. A device of the kind described can be used for embossing a metal body blank (42) for a can, Fig. 12, not shown, the stem (33) of a piston (32) dipping into an hydraulic chamber (35) when the hammer (7) descends so that a resilient diaphragm (40) presses the blank (42) into engagement with a profiled surface (41), the periphery of the blank being temporarily clamped between the mould element (2) and a clamping member (43) secured to a cover plate (34). A resilient element (52) is located in the chamber (35) which is formed by a housing (36) having a stop shoulder (37). When a blank has been clamped in position an hydraulic pump (47) admits oil to the chamber (35) to deform the blank (42) against the profile (41) the flexure strips then being triggered to suddenly increase the pressure in the chamber (35) and emboss the blank (42). Ducts (52) allow exit of oil which seeps past the stem (33), the base member (48) and mould element (2) having a venting aperture 49. In a modified form of this apparatus, Fig. 14, not shown, the device is used to reshape a metal car body.