Patent GB-404336-A (GB)
Title: Improvements in change speed gearing for lathes and other machine tools or the like
IPC: B23Q5/14
Filed: 1932-07-11
Abstract: 404,336. Change-speed gearing ; turning. DARLING & SELLERS, Ltd., DARLING, P., and DEEMING, D. W., Airedale Works, Keighley, Yorkshire. July 11, 1932, No. 19519. [Class 80 (ii).] Change-speed gearing for lathes and other machine tools comprises a cone 2, Fig. 3, of toothed gears driven alternatively from a pinion 4 movable in its own plane and also axially while remaining constantly in mesh with a gear 23 slidably splined on a driving- shaft 11. This change-speed gearing is enclosed in an oil-tight casing 10 and is operated by manipulating a handwheel 28. The pinion 4 is loose on its shaft 5, Fig. 5, which is supported at its ends in two disc arms 6a, Fig. 8, which are connected by a mutilated drum 6f, Fig. 9. The disc arms 6a swing about the driving-shaft 11 which is driven by a train of gears 13, Fig. 3, at one end. The gear 23 is adapted to slide within the drum 6f, Fig. 9, and is controlled by a slide block 25, Fig. 8, which holds the gears 4, 23 in mesh. The block 25, which slides on a fixed guide 26, has a fork 24b engaging the gear 23 as shown in Fig. 9 and an arcuate arm 24, Fig. 8, which remains in engagement with a groove 4a, Fig. 5, in the pinion 4 for all positions of the pinion as the shaft 5 swings about the shaft 11 as pivot. The block 25 is formed with a projecting rack 25c, Fig. 3, always in mesh with a pinion 26w, Fig. 1, through which a splined control shaft 27 is adapted to slide. To change speed, the shaft 27 is first slid to the right of Fig. 1, carrying with it a slide frame 31 which envelops the swing shaft 5 and carries that shaft with it so as to disengage the pinion 4 from the cone 2. The shaft 27 is then turned and, by the pinion 26w and rack 25c, moves the block 25 and pair of gears 4, 23 into the plane of a selected step of the cone 2. The shaft 27 is then returned to the left so as to swing the pinion 4 back into mesh. Upon the shaft 27 is secured the handwheel 28 and a lock block 29 which in gear positions is locked by a spring bolt 32. The bolt 32 is partially withdrawn to unlock by turning a cam 33 fitted with a handle, not shown. The bolt 32 remains in a position 29x, Fig. 11, at the end of one of a number of slots 29a in the block 29. By the handwheel 28, the block 29 is moved right of Fig. 11, turned, and then moved left with the bolt 32 at the end of another slot 29a. The pinion 4 is then in another proper gear position and locking is effected by returning the cam 33. To transmit motion to the guiding screw 37, Fig. 10, of a lathe and to the feed shaft 38, there is fixed upon the shaft 3 of the speed cone 2 a wheel 35, Fig. 5, which meshes with a wheel 36, Fig. 3, splined on the screw 37 to drive that screw in one direction. Reversed motion of the guide screw is effected from a pinion 42, Fig. 5, also fast on the shaft 3, which meshes constantly with an idler 40, Fig. 10, loosely mounted on a stud 41, To effect this reversal, the wheel 36 is slid out of mesh with the wheel 35 and a companion wheel 39, Fig. 3, of the wheel 36 is slid into mesh with the idler 40. The gears 36, 39 which slide together are operated by a handle, not shown. Reversal of the feed-shaft 38, Fig. 10, which is constantly driven from the idler 40, is effected by the usual gearing mounted on the lathe.