GB779381A - Improvements in or relating to machine tools - Google Patents

Abstract

779,381. Drilling; turning. CROSS CO. April 13, 1955, No. 10596/55. Class 83 (3). A machine-tool arrangement comprises a number of work-stations, at least one headstock movable through and positionable in said work-stations, said headstock being provided with a rotatable work-spindle, means for moving said headstock progressively and successively from one station to another, means in said work-stations for locating and clamping said headstock in predetermined positions to hold it stationary while work is performed on a workpiece carried by the spindle, and a driving means in each station for rotatably driving the spindle in said station while the headstock is held stationary by the locating and clamping means. The arrangement described is adapted to handle four headstocks simultaneously and has transfer stations 22, 26, 30, and 8, Fig. 1, which bring the headstocks back to a loading and unloading station 10. Conveyers in the form of sprocket-chains with projections are driven through gearing by a single motor 338 to move the headstocks around the " idle " circuit to the starting point. An operator removes finished work 18 at station 10 and reloads the headstock. The latter is then indexed automatically to the first machinery-station 12, where on one side a drive-unit 36 is coupled to the headstock-spindle to rotate it, and on the opposite side a conventional or other machine 236 is arranged for turning-operations on the work. At a second similar machinery-station 14 the operation may be boring or milling, and the work might be held against rotation. Clamping and indexing. The headstocks 16 are provided with pallet base-pieces 37, Fig. 2a, which have sliding faces on the underside and guide-lugs 94, 96. In moving over the " idle " part of the circuit the guide-lugs support the headstocks on tracks such as 324, 326, Fig. 1. Guide-rails 90, 92, Fig. 2, are provided for the pallets on a housing 88 secured to a base 84. Clamping-levers 116, 118 are provided in the housing 88 and operated for clamping by adjustable springs 156, 158, which bear against plungers 152, 154, moving cam-levers 144, 146 and further plungers 124, 126 bearing against the clamping-lever ends. A rotatable-shaft 104 carries cam-pieces 164 which, when turned anticlockwise, bear against the cam-levers 146 and release the clamping-pressure. Other portions of the shaft 104 are provided with teeth 106, Fig. 3, which engage rack-teeth 108 on a series of locating-plungers 98 for engaging and locating the headstocks. A cover 171 prevents entry 'of cuttings to the clamping &c. mechanism. Rotation of shaft 104 is effected automatically by a piston-and-cylinder 256, Fig. 1, and through the cams and gearteeth, the work-carriers are clamped to the track. The mechanism for moving the headstocks, or work-carriers, from station to station comprises a pivoted and slidable bar 266, Fig. 1, extending along the length of the operative part of the machine, and carrying lugs 268 which engage the headstocks 16. The bar is moved to the right to index the headstocks by a piston-and-cylinder 270 and then rotated to disengage the lugs by mechanism including a further piston-and-cylinders 272. The bar is then returned to its initial position where it is once more turned to engage the so positioned headstocks. Headstock and driving unit. A driving-unit 36, Fig. 2, comprises an electric motor 174 and a belt-drive 182 rotating a shaft 176 in a casing 172. Shaft 176 drives, through pick-off gears 192, 194, a lay-shaft 196. The latter drives a splined gear 206, through the splines of which slides the end of a drive-spindle 208. This spindle, provided with a clutch-end 38, is rotatable in a sleeve 216 which can be moved axially in the casing by rack-and-pinion gears from a spindle 226. A headstock-unit 44, Fig. 2a, carries a work-spindle 50, provided with a conventional chuck 56, which is driven through reduction-gears 72, 70, from a clutch part 40. After the clutch parts 40, 38, have been automatically brought into alignment, a piston-and-cylinder 264, Fig. 1, turns the spindles 226 and thus moves the clutch-parts 38 to engage the headstock clutch-parts 40.