Improvements in and relating to circuits for tracer controlled lathes and other machine tools

摘要

609,819. Operating clutches. TRIGGS, W. W. (Niles-Bement-Pond Co.). July 17, 1945, No. 18325. [Class 80 (ii)] [Also in Groups XXII and XXXVIII] A tracer-controlled lathe, or like machine having electromagnetic clutches for controlling movements of the tool slides is provided with relays operated by the tracer to control the clutches, and a supplementary relay, operated by one of the clutch-controlling relays, closure of which introduces resistance into the energizing circuit of whichever clutch is in operation. On the application to a lathe, Fig. 2, a tracer 31 moves over a pattern 33 and according to the inclination of the latter operates relays to effect the opening and closing of electromagnetic clutches 10, 12 which control the forward and reverse movements of feed screws 7 and 20 for the longitudinal and cross-feed movements respectively of a tool-carrier 18. The tracer 32, Fig. 4, of known construction, includes a lever 39 biassed by springs in an anti-clockwise direction to close contacts 42, 43 for the " in " feed of the tool. The circuit thus " made is through the earthed tracer head 31, lever 39, contacts 42, 43, lead 63, solenoid of triple pole " in " relay and lead 67 to a grounded generator 68. Energization of " in " relay opens circuit to longitudinal feed clutch " E " or " W " and thus stops feed of main carriage and at the same time closes contacts 77 and 81, the former closing the circuit to the " in " clutch at line potential and the latter closing a circuit to the supplementary relay R. The latter operates immediately after the " in " clutch is energized to open contacts 87 and close contacts 90. The circuit from the live wire 76 to lead 80 must now traverse a resistance 88 reducing the potential to hold the " in " clutch. The closure of contacts 90 at the same time cuts out a resistance 91 from the circuit to the " E " or " W " clutch magnet (according to which has been selected by a hand switch 92) so that when this is again energized it will be at the full potential of the line. The supplementary relay operates similarly when the " out " relay is energized by movement of the tracer to close the contacts 50, 51. U.S.A. Specifications 1,518,114 and 1,711,290 are referred to.