Patent GB-463592-A (GB)
Title: Improvements in machines for performing cutting-off and other operations on bar stock
IPC: B23D21/00
Filed: 1936-04-09
Abstract: 463,592. Lathes. GUHRING, A. April 9, 1936, No. 10575. Convention date, April 10, 1935. [Class 83 (iii)] In a machine for performing cutting- off and other operations on bar stock has two or more vertical work spindles with associated tools, the spindles being supplied by a single overhead magazine drum which is rotated step by step to supply fresh bars as those in the spindles become exhausted. The magazine consists of a number of bar holding tubes 2 slidable in circular openings 24 in upper and lower discs 21, 20 respectively. A central slotted supporting disc 22 is also provided. The tubes have lower abutments 25 which rest on the lower disc. Below the lower disc is a release disc 26 having apertures 27 which are normally covered by the ends 28 of pivoted levers 30. Two work spindles 3 are arranged below two diametrally opposed tubes 2 so that work bars can pass from the magazine into the spindles. Each spindle coacts with a cutting off. tool 8 mounted on a slide 7 and operated by lever mechanism 53, 54. A stop mandrel 11 is controlled through a spring 12 by a cam 14 and passes through a container 15 into which the chips are deflected by a shield 16. The cut off pieces pass down a trough 15a into another container 15c. Each spindle 3, having pulleys 3<1> driven from a main driving pulley 67 by a belt passing over guide pulleys 68, 69, carries a chuck operating sleeve 17 actuated by a lever 33 pivoted on a spring mounted member 34. The lever is operated from a crank-pin 38 on a disc 40, driven through a clutch 41, bevel gearing 42, chain gearing 44, 45 from a shaft 45a connected to a driving motor 46. The clutch is controlled by a lever 47 operated through a chain 48 and lever 49 from the tool carriage. When the tool carriage is returned after a cutting-off movement it operates the lever 47 to engage clutch 41, thus operating the lever 33 to open the chuck and allow the gravity feed of the bar against the stop 10<1>. The closing of the chuck is delayed by the lost-motion slot 39. When a fresh rod is fed into the chuck it falls on to an auxiliary stop 32 on a member having a vertical slot engaged by a pin on a toothed member 50. The teeth are engaged by a pawl on a rod 51 forming part of the tool lever mechanism so that at each stroke of the tool the stop 32 is moved back and after two strokes the stop which is prevented from return movement by a notched member 56 disengages the bar and at the next chuck operation the bar falls on to the stop 11, which after the chuck has been closed, is withdrawn by cam 14. The tool carriage is operated by a cam 61 actuating a follower on an arm 53<1> pivoted at 53<11> to the lever 53. The magazine disc 26 is under the pull of a chain 71 carrying a weight 73 and is provided with locking teeth 75 engaged by a tooth on a lever 76 coacting with a cam projection 80 angularly adjustable on a wheel 81 which is under the torque produced by a weight 85. The wheel is normally locked by projection 86 on a lever 87 which is engaged by the tail of the lever 76 and by an abutment on a rod 89. At each cutting operation the wheel 81 is moved one step by a pawl 90 against the arrow p until the projection 80 operates lever 76 and disengages the tooth 78 thus allowing the magazine to be fed one step. The lever 76 also disengages the pawl 86, which is held disengaged by the rod 89 until the wheel 81 has been returned by the weight 85. When the magazine is fed, two of the levers 30 holding up the bars engage projections 31 and are swung aside so that bars can fall in to each of the two work spindles. The movement of rod 89, produced by the teeth 75 releases the auxiliary stop 32 which then moves forward to stop the descent of the fresh bar. The adjustment of the cam 80 is determined by the number of pieces which may be cut from a bar. If the resistance to the forward movement of the tool becomes excessive, the arm 53<1> compresses a spring 63 and makes an electric contact 95 to stop the motor or alternatively a mechanical stop device may be employed. After a half revolution of the magazine and all the bars have been used the disc 26 may be stopped so that the pawl 86 is not released and the wheel 8 advances beyond its normal position and the additional movement of the weight 85 may be arranged to actuate a stop device. In one form the weight 85 may operate a lever 97 connected by a chain 99 to a switch for this purpose. If the stock bar is too thin it will not be rotated by the chuck and the machine will be stopped by the tool release mechanism. In a modification more than two working spindles may be employed.