Patent GB-479695-A (GB)
Title: Improvements in metal cutting machines
IPC: B23B9/02
Filed: 1936-09-30
Abstract: 479,695. Lathes. FAIRWEATHER, H. G. C. (National Acme Co.) Sept. 30, 1936, No. 26566. [Class 83 (iii.)] An automatic multi-spindle lathe comprises a pair of spaced housings forming an open top machine with a reciprocating tool carrier located between the housings, one of the housings supporting an electrically indexed work turret, the cam shafts being located below the work turret and being driven by a power unit located behind the work turret. A central column 3 extending from the panbed 1 supports the spindle-carrier and is connected by a bracket 4 to the stock reel 5. The forward end of the bed carries a column 6 serving as a cam drum housing, leaving an open frame between the columns for the reception of chips which are removed through an opening 7. A chip shoot may be aligned with the sloping bottom of the bed and may serve as a guard for the opening 7. Two cam shafts 35, 36 one on each side of the machine are mounted between the housings 3, 6. The work turret carries five spindles 9 adapted to carry 5-inch bar stock and is integrally secured to a central stem 10 supported in the housing 6. The central sliding tool carrier 11 moves on the stem 10 and is guided at 12 on an extension 13 from the housing 6. The slide is operated by a, rod 14 and cam drum 16. Another cam drum 17 located within the housing 6, is driven from the cam shaft 36 and controls tool spindles 17a, for boring, turning, reaming, &c., these spindles being supported on the main tool slide but operated independently thereof so that if the main slide travels one inch to start an operation the spindles 17a may travel two or three times this distance to finish the piece. The motor 18 drives a gear box 19, Fig. 11, from which a shaft 20 extends into the housing 6 where it is connected by a chain to a, gear 22 engaging a central gear 23 on a shaft 24, extending into the work turret and driving the gears 26 on the work spindles. An oscillating stock stop 28, Fig. 1, is operated from the cam shaft 35. A shaft 71 of the gear box is connected through worm gearing 39 to a shaft 27 which extends across the machine and drives through worm gearing 31, 32 the cam shafts 35, 36. A clutch 72 enables hand control of the slides for setting to be performed. Two cross slides 41, 42 are arranged at each side of the machine and are operated from cam discs 43, 44 by rack segment levers 45, 46. A top slide 47 for forming cutting-off, knurling, &c., is operated by a cam disc 48 driven through chain gearing 49 from the cam shaft 36. The turret indexing mechanism is electrically actuated and comprises a spring pressed locking bolt 50 operated by a cam 52, Fig: 4, acting through a lever arm. When the bolt leaves its seating it operates a switch 53 to start the motor 55 which then rotates the turret until the index bolt drops into the next notch and switches off the current. A governor 57 stops the motor within half a revolution thus allowing the bolt to seat firmly. A spring cushions the worm to prevent strain when the bolt engages its seating. The turret may be turned by hand through the crank 60. For this purpose the cover plate 62 must be removed and thus a switch in the electrical circuit which is normally kept closed by the cover plate, is opened to prevent electrical operation during the hand adjustment. Another safety mechanism is provided by inter-connectecl levers which control a clutch in the cam shaft drive and are arranged to operate a switch to cut off current from the indexing mechanism. The gear M, Fig. 11, on a shaft driven from the motor through chain sprockets N, engages a wheel L on shaft 71 and when clutch 70 is engaged a high speed is imparted to shaft 27 to return the tool slide and operate the indexing and stock feed mechanism. When the sleeve O is changed over to the braking clutch 69 the shaft 71 is slowed until a roller clutch P engages for the positive low speed drive derived from gear box shaft Q through change gears A and shaft Z. The shaft Q of the gear box drives the spindles through the shaft 20 as above described and is driven through change gears Y. The machine is lubricated throughout by an oil splash system. Specifications 410,135 and 479,744 are referred to.