Patent GB-1352681-A (GB)
Title: Lathe with tool turrets
IPC: B23B3/16
Filed: 1970-04-11
Abstract: 1352681 Turret lathes; tool changing ALFRED HERBERT Ltd 19 April 1971 [11 April 1970] 17337/70 Headings B3T and B3B A lathe comprises a frame, a headstock with a power driven spindle on the frame, turret mount means for receiving a tool turret with tools for use in machining a workpiece carried in the work-spindle, a turret storage device for storing turrets not located on the turret mount means, turret transfer means for transferring the turret from the storage device to the mount means and means for indexing the turret when located on the mount means. In the embodiments described, the turret mount means is positioned on a cross slide 16, which in turn is mounted on a carriage 15 which traverses the lathe bed 11 which is supported on the frame 10. Each turret 18 or 19 has a base portion 21 and a turret part 22 which is angularly and axially movable relative to the base portion 21. The turret part 22 has a coaxial spigot 22a with a transverse dovetail groove 22b, the base part having a similar groove 21a. Co-operating axially extending toothed locating rings 23, 24 on the turret part and turret mount 17 respectively are engageable to accurately locate the turret on the cross-slide 16. The turret mount means includes a socket, formed by ring 24 which receives the spigot 22a, the ring being fitted into a bore 28 in the crossslide 16 and a clamping piston 25 slides in this bore. The piston has a dovetail projection 29 which is complementary to the grooves 22b and 21a, the piston being displaceable to align with a rib 30 on the cross-slide during a turret changing operation. The turret storage device 20 includes plates 44, 45 with track portions in the form of dovetail ribs for co-operation with the turrets 18 or 19 respectively. The plates 44, 45 are carried on a head member 46 which is displaceable on rails 47 which extend at right angles to the directions of movement of the saddle and cross-slide. The turret mount is provided with a transfer device 50 in the form of a sliding member displaceable on the rib 30 and which has a dovetail slot 51 and each base part 21 has a complementary dovetail 52. To effect a turret changing operation the cross-slide is firstly moved to a predetermined position in which the ribs 30 and 44a are aligned, the carriage 15 and head 46 are then displaced towards one another and are arrested when they meet, at which position the rib 30 on the slide 16 is continuous with the rib 44a. The piston 25 is actuated to release the turret 18 and permit its displacement by the device 50. The head 46 is then displaced along rails 47 to an alternative position which moves the turret 18 from the locating position on the turret mount and brings the fresh turret 19 into position on the mount. The piston is then actuated to clamp the turret on the mount 17 and the head is returned to its inoperative position. The indexing of the turrets when on the mount means is effected by hydraulically actuated rack and pinion means 53, 54. Alternatively the indexing may be effected by a gear drive from an hydraulic motor. In an alternative embodiment the turret storage device is mounted on the machine carriage thereby eliminating movement of the carriage to effect the turret changing operation.