Patent GB-858676-A (GB)
Title: An improved automatic lathe
IPC: B23B7/04
Filed: 1957-10-03
Abstract: 858,676. Automatic lathes. HODGE, H. C. D. Oct. 1, 1958 [Oct. 3, 1957], No. 30956/57. Class 83 (3). An automatic lathe comprises a cylindrical casting having a smooth-bore secured between the upper ends of two similar vertical plates mounted on a bed, two further plates in recesses in the first plates having tool-turret carriage slideways secured thereto, an inversed bridge member under the slideways secured to the further plates, and the bed below the further plates being boxed in to form a cabinet. The single spindle automatic lathe, Fig. 1, comprises a cam drum 20A coaxial with the spindle 9 for operating a reciprocating gripper 10A in the headstock 11, tools 23 adjacent the headstock, a collet 5 coaxial with the spindle, and a toolturret carriage D, said turret being indexed at the non-operating positions by a device driven from a shaft 13, which also drives the cam drum. The headstock 11 is supported at the upper ends of two plates A, A and comprises a reciprocating liner 1 which actuates the collet 5 through fingers 3 and a sleeve 4, and the reciprocating gripper 10A driven from a face cam 47 on the cam drum 20A by a spring-urged follower 48 secured to a sleeve 49 connected to the rear end 10 of the gripper. Arranged in sequence with the headstock device is a toolturret 62 supported on the carriage D, having angular members 18, Fig. 2, secured thereto which slide between slideways 17 secured to plates B, B, which are secured to the edges of plates A, A. The device for indexing the turret comprises the shaft 13, Fig. 1, driven intermittently from a power source by a gearwheel 21, said shaft rotating a shaft 28A which passes freely through a hub 27 supported by a bearing 32 in a member 60 screwed to the plates B, B, and is connected to the inner end of a gramophone-type spring S, the other end of which is connected to a flange 26 on the end of said hub. A slidably-mounted member 28 having dogs 29, normally held in engagement with the dogs on flange 26 by the spring S, is connected to a turret-locking device 34 by a rod 33, and carries a pivoted fork 31 secured to an arm 30, which disengages the dogs when the turret is moved to the right. The carriage D is reciprocated towards the headstock by a lever system 61A actuated by a cam C1 on the cam drum 20A, and the turret has a disc 36 secured thereto, having pegs 64 which engage with pegs 65 eccentrically mounted on a flange of the hub. On rotation of the hub by the spring S when the dogs 26A, 29 are disengaged, the turret is indexed to the next tool station. On the upper side of the disc 36 are projections 35 which are engaged by the locking means 34. In operation, with the turret moved to the left, the shafts 13, 28A rotate, and due to the engagement of the dogs 26A, 29, the member 28 is rotated until the member 34 engages a projection 35, and the spring S is tensioned. The carriage D is then moved to the right and the disc 36 engages the arm 30, which is normally held parallel to the plates B, B by a spring and pivots it in a horizontal direction, thus disengaging the dogs 26A, 29 and giving the hub 27 half a revolution. There are twelve pegs 64 on the disc 36, and two pegs 65 on the hub 27. Thus the turret is indexed onetwelfth of a revolution, i.e. to the next tool position. The turret is then moved to the left, the arm 30 returns to its parallel position, and the dogs are engaged, the turret being again locked. To operate the headstock, a toothed clutch member 42, eccentrically rotatable on shaft 13 but axially fixed, is driven by a gear train T. A member 40 connected to a similar clutch member 41 is oscillated when the clutch .is engaged and rotates the liner 1 by a pin 7 secured thereto. Angular slots 6 in the liner engage rollers secured to the headstock 1 by pins, and thus cause axial movement of said liner for actuating the collet 5 by fingers 3 and the sleeve 4, in known manner. The member 40 has connected thereto a lever 40A, Fig. 3, rotatably mounted in the plates A, A, and having a pawl 53, Figs. 1 and 3, which engages with a similar pawl 52 on the reciprocating gripper for disengaging the latter from the face cam 47. The clutch is disengaged by an arm 46 which moves a pin 43, secured to the clutch member 41, into a slot in a bush 44, and as a gear-wheel 20, Fig. 1, on the cam drum, which is driven by a chain from the shaft 13, rotates, a peg 45 actuates a projection on the spindle 46A of the arm 46, pivots the arm and allows the member 41 to be spring-urged into engagement with the member 42. Cams C2-C4 on the cam-drum operate tools 23 connected to shafts 22 rotatable in the plates A, A and a worklength control finger 54 is connected to the member 40 and is reciprocated by an arm 56, which actuates an arm 55a, Fig. 3, secured to the shaft 55, against a spring 57. The collet 5, Fig. 1, may be operated manually when loading the machine, by the extension 40B on the member 40.