Patent GB-784407-A (GB)
Title: An improved bar feed for automatic lathes and other machine tools
Inventor: VANN HENRY EDWIN
IPC: B23B13/00
Filed: 1954-10-21
Abstract: 784,407. Lathe details. RATBY ENGINEERING CO., Ltd. Oct. 14, 1955 [Oct. 21, 1954], No. 30340/54. Class 83 (3). [Also in Group XXIII] A bar feed for lathes &c., of the kind in which a horizontal tube for feeding the bar is carried on a stand, and a weight-operated pusher presses on the end of a stock bar to feed it into a machine, has the tube divided longitudinally into two sections which are separable to open the tube at one side, means being provided for effecting separation and simultaneously acting upon a fresh bar on an adjoining support so that it is permitted to move laterally into the tube through the opening. The bar feed apparatus is supported on a number of vertically-adjustable pillars 6, and an inclined rack 2a, Fig. 4, supports a number of stockbars 15, which may, however, be arranged in a vertical magazine. A number of aligned step-pieces 19 prevent the stock-bars from rolling down the rack, and when a new bar is to be fed into the tube 1, Figs. 1A, 1B, the top portion 1a, Fig. 4, of the tube, which is secured to a number of brackets 3 rotatable with a shaft.4, is moved away from the fixed lower half 1b and thus produces a gap at the side adjacent the rack. Levers 3a, also secured to shaft 4, have tongues 21 which, simultaneously with the opening of the tube 1, lift the lowermost new bar 15 over the obstructions 19 so that it rolls down through the gap into the tube 1. A push-rod 18 secured to a bracket 17 engages the end of the bar, and the bracket projects through a small longitudinal gap in the tube and is connected to an endless chain 23, Figs. 1A, 1B, which passes over chain wheels 25, 26 at each end of the apparatus. The wheel 26 is connected to a handwheel 70 so that the bar feed can be controlled when first entering the machine spindle, but in normal operation the pusher is moved by weights 24, Fig. 1A. An electric motor 56 is provided for withdrawing the pusher and its bracket 17. The latter slides along a longitudinal rail 16 and the motor drives a chain 59 connected to the rear chain wheel 25. In operation, when a bar has been used up, the bracket 17 trips a lever system 63, 64, Fig. 1B, which through a latch 71 allows a stop 68 to close the opening from the tube 1. At the same time a switch 61 is operated to start the return motor for the pusher. When the latter approaches its fully withdrawn position, a roller 75, Fig. 4, on the bracket 17 engages a cam 74 secured to a stirrup 73 secured to the shaft 4. This action operates the tube opening mechanism for the feed of a new bar. At the same time a further switch is operated to stop the motor and the bracket 17 engages a projection 77 from a buffer 78. The weight device commences forward feed of the new bar, but this is halted by the stop 68. This stop may be opened by a hand-lever 69 and the bar eased into the machine-spindle by the handwheel 70, after which the bar feed may be automatic again. A false nose piece is used on the end of the pusher 18 for centralizing small-diameter bars, and automatic means are described for disconnecting and reconnecting this with the pusher at the forward and rearward positions of the latter respectively.