GB701348A - Improvements in or relating to dividing devices for machine tools - Google Patents

Abstract

701,348. Milling. AKTIEBOLAGET SVEAEXPORT. Jan. 30, 1952 [Feb. 21, 1951], No. 2514/52. Class 83 (3). [Also in Group XXIII] An indexing device for a machine tool comprises a helically-grooved shaft 5 reciprocable in a sleeve 4 to rotate it, the degree of rotation being determined by the length of stroke of the shaft. The shaft is reciprocated by a flywheel 10 rotated by a pinion 9, a shaft 11 carrying a pinion 16 engaging a stationary internal gear 13, and a crank pin 17 engaging a slot in a member 18 fast with the shaft. The length of stroke and hence the degree of indexing, which may be (nx360+α) degrees, is determined by adjustment of the gear 13 by means 25, 26. The work 31, on which straight teeth are milled or ground, is reciprocated oppositely from the shaft 5 by a crank 35 on the wheel 10 and is indexed by a gear 40 connected to the sleeve 4 by a gear 39. On a working stroke, a clutch 42 holds fast the gears 39, 40 and, on the return stroke, a clutch 37 transmits the rotation of the sleeve 4 to the work to index it. The clutches are actuated by stops 43 on the wheel 10. In a modification, a gear mounted on a swinging frame may be engaged between the gears 39, 40. In a further modification for grinding twist drills, reamers &c., a helical motion is given to the work by a second helical shaft 52, Fig. 4, which reciprocates in time with the work and transmits a helical motion via a sleeve 51 and gears 63, 40. The indexing shaft 5, the shaft 52, and the workshaft 28 are reciprocated by adjustable cranks 57 on a common shaft 60, or by means similar to that of the first embodiment. The controlling clutches such as 37 may be electromagnetically operated. The device may be so arranged that only a portion of the working crank movement is effective and the cutting then takes place at approximately constant speed, which is desirable when a grinding disc speed of 100 metres/second and a feed of 1 metre/second is employed. In yet another modification for grinding straight teeth, the work is reciprocated by a hydraulic piston 73, Fig. 6, and is indexed by a helical shaft 75 whose rotation is controlled by clutches 78, 82 actuated by dogs 87, 88 and levers 84 ... 86. The work may also be reciprocated pneumatically or electrically.