Patent GB-858575-A (GB)
Title: Apparatus for the exchange of tools in machine tools, such as stamping presses or the like
IPC: B21D37/14
Filed: 1959-05-07
Abstract: 858,575. Metal working presses; stamping. ESSA MASCHINENFABRIK AKTIENGESELLSCHAFT VORM. PRESSENFABRIK S. ALLEMAND. May 7, 1959 [May 22, 1958], No. 15660/59. Class 83 (4). Apparatus for the exchange of tools in machines such as stamping presses wherein only a lateral opening is available in the machine for the exchange of the tools, is characterized by the arrangement at the side of the press available for the exchange, of transport tracks and transporting apparatus and a control mechanism operating hydraulically, with which the exchange of tools can be carried out positively in timed sequence. In an embodiment an apron table 2 is annexed to a four-column stamping press 1. On one side of the table is a departure track 3 and on the other side a tilting table 4 operated by an hydraulic cylinder 43. The gaps between the tables and track are bridged by rollers 6. The press table 5 is enlarged at one side by a feed table 8, on which are mounted pusher mechanisms (not shown) for the band or strip to be stamped. Annexed to the apron table is an hydraulic pulling and pushing mechanism 9 comprising a piston-rod 11 carrying hooks 14 for engaging a tool 16 to be fed to or removed from the press table as shown in Fig. 3. The piston-rod of an hydraulic ram 21 releases the hooks from the tool after the feed stroke. The tool is automatically centred on the press table by stops 26 which engage on recesses 25 on the base of the tool. Hydraulic pistons with hammer heads 29 engage in T-slots on the tool to clamp it on the press. The safe fixing of the tool is ensured by means of a pressure regulated control element on the hydraulic system operating the press and the exchange apparatus which only allows the stamping operation to take place when the pressure in the tool clamping cylinders is sufficiently high. Differences of height between different tools is accommodated by using packing pieces and interposed wedges. The tilting table 4 carries a further mechanism 38 directed towards the departure track 3. The piston-rod of the pusher mechanism 38 carries a cross-head 40 provided with setting screws 41. Pivoted levers 48 are connected to the tilting mechanism of table 4 to engage and push back succeeding tools on the feed track 44 behind the tool 16 on the tilting table 4 to enable the pusher mechanism 38 when the table is levelled to push the tool 16 on to the apron table 2. From the table 2 the mechanism 9 pushes the tool into the press where it is centred and clamped in position. Meanwhile, the pusher mechanism 38 returns to its initial position and the table 4 is tilted to receive a new tool from the feed track 44. If a damaged tool situated in the press is to be exchanged the hooked piston-rod of the pulling and pushing mechanism 9 is moved into the press to engage the tool and withdraw it on to the apron table 2 from where, on release from the mechanism 9, it is pushed on to the departure track 3 by the succeeding new tool being fed on to the apron table by the pusher mechanism 38. The hydraulic system operating the press and the tool exchange mechanism is controlled by a cam-operated hydraulic distributer operated either by hand or by a fully automatic electric control system.