GB826347A - Improvements relating to clicking presses - Google Patents

Abstract

826,347. Machinery safety devices. LOTUS Ltd. May 7, 1956 [May 6, 1955], No. 13127/55. Class 80 (4). In a clicking press in which the engagement of the clutch is effected through electromagnetic means under control of main switch means associated with a gripping member on the presser beam and additional switch means positioned so that they cannot be operated by the same hand as that employed on the gripping member the switch means are so arranged that they must both be restored to their circuitbreaking positions before a repeat operation of the press can be carried out. This is effected by an interlocking circuit as shown. The energization of a clutch-operating solenoid 15 by a high-voltage current source to motor 19 is controlled by a low-voltage coil 211 as described in Specification 663,477 the arrangement being such that after energization of the solenoid 15 a single stroke of the press is effected and for a second stroke the solenoid 15 must be first deenergized and then re-energized. The energization of solenoid 15 is effected through closing contacts 21 controlled by low-voltage coil 211 which is energized by the closing of contacts 141, 142 of a relay 14 which is in turn energized by the closing of the contacts 131, 132 of main switch 13 and either the contacts 171a, 171b of switch 171 or the contacts 172a, 172b of switch 172. The contacts 141, 142 also provide independent circuits for energizing the relay 14 through either the main switch or the relevant auxiliary switch so that both of these switches must be opened to de-energize the relay 14 and hence the solenoid 15. Stop and start push-button switches 18a, 18b are provided for the motor 19 and the low-voltage supply of current is derived from a step-down transformer 20. Specification 667,731, [Group VIII], also is referred to.