| 摘要 |
<p>1,137,674. Mechanical presses. COWLISHAW WALKER & CO. Ltd., N. H. POUT and D. HOLDING. 17 Jan., 1966 [18 Jan., 1965], No. 2178/65. Heading B5F. [Also in Divisions B3 and G3] . A power press having opposed tool carrying platens, which are movable towards and away from one another in the cyclic operation of the press, has one of the platens adjustable to suit a range of tools, the adjustment being effected in dependence on the output of a comparator responsive to a coded signal in a memory device, representative of the existing adjustment relative to a datum, and a coded signal, representative of a desired adjustment relative to the datum. As shown in Fig. 8, a reciprocated connecting rod 19 is pivotally connected to a member 20 to impart a vertical thrust. The member 20 is threaded on its lower portion and engages a nut 21 having worm teeth on its periphery. The nut is free to rotate about the axis of the member 20 but is constrained vertically, so that rotation of the nut causes relative motion between the member 20 and a tool-carrying slide 22 to adjust the slide working face with respect to the lower platen, not shown. The nut 21 is rotated by a worm, not shown, driven by a motor 24. The slide adjustment is effected at a tool change by a programme control system, Fig. 11, wherein a card is inserted in a reader 33, and the digitally coded read signals are compared with digital coded signals stored in a memory of a comparator 35, representative of the actual adjustment with respect to a datum of the slide. The comparator output actuates a reversing contactor 30, 31 controlling the slide adjusting motor 24. The movement of the motor causes a vane geared to the motor to actuate a proximity switch, pulses from which are stored in the memory and the motor is stopped when the comparator output falls to zero. A tool change cycle comprises bringing the press to rest near top dead centre, a switch 32 is then moved to auto and an initiation button 38 depressed. The press slide then descends to rear bottom dead centre where it is stopped by a switch 40. The tools are then changed and a card inserted in the reader. Manual control is effected through the switch 32 and pushbuttons of contactor 30, 31. It is stated that a plurality of presses can be controlled from a common point and that the cards can be replaced by a magnetic tape.</p> |
