21,397. Macdonald, A. Oct. 21. Lathes.-Combined grinding and turning lathes for shafts, pins, tools, &c. are arranged to dispense with overhead gear for the grinding-apparatus and to deal with taper work. The driving-cone 92, Fig. 1, is mounted on the headstock spindle, and is geared at 98 and g to a shaft e driving a shaft a through a belt c, intermediate shaft, and changespeed gearing 85. The grinding - wheel n is mounted on a base swivelling on a cross-slide 3 of a saddle x, and is driven from the shaft a by sliding bevels y, z, shaft 1, bevels 6, 7, sliding shaft 9, bevels 10, 11, and belt 14. The cross-slide is slotted to clear the shaft 1, and the base swivels on a circular strip concentric with the shaft, so that a universal drive for the wheels is obtained. A worm and wheel is provided for swivelling the base. A universal drive may be obtained by using two belts arranged as shown in Figs. 6 and 7. In another modification, one belt only is used and the wheel base has only a transverse motion. The cross-slide 3 has a hand-feed operated by a rack and pinion worm-driven at 56, Fig. 20. When two emery wheels are required, their saddles are connected by telescopic rods 54, the hand-feeds are connected by bevels and a cross-shaft 58, star clamping-handles 60 providing for disconnecting either feed at will. The saddle is traversed by a screw p, bevel-geared through an inclined shaft q to a shaft o driven tbrough change-speed gearing from the shaft e. A clutch part r is fastened to the shaft o, and co-operates with clutch parts formed on a wheel 100 loose on the shaft and with a wheel 102 keyed to a screw s. A reverse motion is thus obtained for both the grinding-saddle and a control carriage t. The latter is provided with a nut to engage the screw s and with a wheel splined to the screw and geared to a disconnectible hand-wheel. A handle zo provided with gripping- blocks 114, 115, Fig. 25, engaging a rod 25, provides for sliding it to control the clutch r, and tappets on this rod provide for automatic reversal by the carriage at the ends of its traverse. The gripping-blocks are spring-controlled as shown so that when the handle has completed its operative movement in either direction grip ceases, allowing the carriage t to move without affecting the clutch rod 25. A handle v geared to a splined wheel on the rod locks the clutch in its inoperative position by turning the rod to engage a recessed sleeve on it with a fixed pin 91. The turning-saddles are connected by a stay 29 and lock-nuts, and the lead-screw nuts are connected at 34. The looknuts consist of half conical nuts 30 engaging whole recessed nuts 31. Two tool-boxes 28 are provided to each saddle, controlled by right and left handed screws 36 rotatable -from a common handle through worm-gearing and a coupling-rod. The worm-wheels are connected to the screws 36 by hand-operated clutches. To grind on deadcentres, a clutch 24 locks the spindle j, a clutch disconnects the gears from it, and a driving-plate 23 is driven through the wheels 74, 77. When the lathe is required for turning only, a clutch 47 uncouples the shaft f, which is made in two parts. When grinding without turning, a clutch placed for example at 48 disconnects the lead-screw. The headstock, tailstock, and turning-saddles are mounted on a plate i swivelling on the shaft f, or about a circular strip concentric with the shaft, when required for machining to a taper. In this case, the tool slides 28 are disconnected from the screws 36 and are attached at 53, Fig. 21, to rods 52 carried by arms 83 on a block sliding in guides on the bed. Pins on the saddle pass through holes in the arms 83, and thus as the saddle travels along the plate i the tools move parallel to the bed and taper turning results. To relieve the tailstock holding down bolts, a detent 43 with a handle 45 engages teeth on the face of the plate i. In modifications of the machine, the pulley 92 may be placed on the shafts a, e or on the intermediate shaft; the clutch 47 is then unnecessary. A modified form of plate i is provided with one or more gaps and swivels on a similarly gapped bed about a centre pin. The sbaft f is then made extensible and is fitted with universal joints.