Patent GB-547458-A (GB)
Title: Improvements in driving mechanism for lathes and like machine tools
IPC: B23Q5/18
Filed: 1940-11-21
Abstract: 547,458. Machine details; turning. TRIGGS, W. W. (Warner & Swasey Co.). Nov. 21, 1940, No. 6745. [Class 83 (iii)] A change speed transmission for lathes and like machine tools has a centralized control for selecting or preselecting the speed of the spindle 45 and also for operating other mechanisms such as the cross slide carriage 42, Fig. 1, and the turret slide saddle 43. The control mechanism is enclosed in a container 91 and comprises indexing devices 193 ... 195, each formed of a number of independently adjustable rings provided with a projecting tooth which can be set to control the adjustment of a pair of spools 130, 177, Fig. 21, which are formed with co-operating projections of different lengths and which when moved towards each other control the position of pins 115, 118, 125, Fig. 16, on levers which move twostep or three-step cone gears to produce the required speeds of the work and tools. The spindle 45 can be driven at twelve speeds, and a selection of six speeds can be chosen for the carriage 42 and saddle 43 which are driven from spindle 45. From the main drive shaft 50 the spindle 45 is driven through two two-step cone gears and one threestep cone gear, and a moveable clutch element 52 can be shifted to engage elements 51 or 53 which drive in different directions, or the clutch can be in neutral, and a slow drive can then take place through bevel worm gearing 77, 78, 81, Fig. 30, and a clutch 83 or a friction clutch which is thrown-on by toggle mechanism 102 under control of a main lever 84 and levers 94 formed with projections 96 and hooks 95. The gear changes are effected when the slow drive is operative. The shaft 88 of lever 84 is also fitted with a lever 90 for operating the clutch member 52. The lever 84 is moved in a vertical plane to the two positions shown by dotted lines in Fig. 16, and can also be moved in a horizontal position to occupy the positions indicated by the dotted lines CF, F, CR, R, Fig. 30 as well as the position N which corresponds to the neutral position. The lever 84 is universally mounted and has an arm 137 which operates lever mechanism to move the spools 130 to and fro. The indexing devices 195 for the spindle and 193, 194 for the slides are constructed of a number of discs each formed with a projecting tooth 248, 257 each formed with a number of slots corresponding to the number of gear changes which can be effected. The discs are set so that the tooth 248 or 257 is opposite the required index number on a scale 243; and the discs are held in place by pivoted bars engaging notches in the disc and held in place by a split ring 253. Gears 197, 200, 221 on the discs are geared to the spools 130, 177 as shown in Fig. 21. The discs are driven frictionally from a shaft 196 operated by a onerevolution clutch auxiliary gears 229, Fig. 5, and a pulley 225 from the main drive shaft, and the positions at which the discs stop is determined by the engagement of the projections 248, 257 with arms 258 on a slide 259 which is moved stepwise to the right by screw mechanism operated by a shaft 260 which is rotated intermittently by ratchet mechanism actuated by a lever 272 controlled by a cam 277 on one of the spools 132, this action preceding the release of the one-revolution clutch by a similar cam 285. The control mechanism is set for a given number of operations e.g. six, and after these have been performed the mechanism is stopped automatically by setting the discs so that projections N, which correspond to a neutral position of the two-step cone gears, act upon the arms 258 and cause the spools to move the cone gears to neutral. Also the ratchet mechanism which operates the shaft 260 is automatically declutched and a spring restores the shaft to its original position and returns the slide 259 to its starting position. When the required gear change for the spindle has been effected the slide 42 and saddle 43 are adjusted in position and they are then put into operation by levers 168, 174 which operate clutches to bring their driving mechanism into action at the required speed. A scale 279, Fig. 5, indicates the position to which the shaft 260 has been adjusted. Specifications 524,441, 530,324, [Group XXIV], are referred to.