GB622423A - Improvements in or relating to dividing heads for metal-cutting and like machine tools - Google Patents

Abstract

622,423. Work-holders; indexing. MARKLAND ENGINEERING CO., Ltd., and RICRARDSON, W. March 21, 1947, No. 7853. [Class 83 (iii)] A dividing-head for carrying work in a lathe so that splines and spur and bevel gears may be cut by a milling-cutter comprises a work-holder 22 co-axial with and rotatable in relation to an indexing ring 26, means for locking the wlrk-holder in adjusted position relatively to the indexing ring, and a shank 10 angularly adjustable with respect to the common axis of the work-holder and ring carrying the head from the tail-stock of a lathe. The shank 10 is pivoted at 15 between plates 13 on a body 14, and is locked in the adjusted position by a bolt 18 sliding in arcuate slots 17 in the plates, the position being indicated by graduations 19 on a flange 16 on the shank. The work-holder 22 is mounted on a tapered rollerbearing 21 held in a bore in the body 14 by a screwed cap 24, and is axially adjustable by a screw 45 engaging a ball 46 so that a flange 23 may adjust the inner ball-race to take up play. The interchangeable indexing-ring 26 is held in place by a cap 29 screwed on the work-holder, and has two or more series of holes 27 on one face and similar, but differently-spaced, holes 28 on the other face; the holes 28 may be omitted if differential indexing is not necessary. An indexing-lever 33 is adjustably mounted on the cap 29 by studs 34 and slots 52, Fig. 4, and carries a spring-pressed plunger 35 on which an arm 37 with a locating-pin 38 is pivotally mounted so that the pin 38 can be engaged in any selected series of the holes 27. The plunger is withdrawn to disengage the pin by a handle 39, but, in the modification shown in Fig. 7, the handle turns a spindle journalled in the plunger 35, and an eccentric 39A on the spindle or on the handle bears on the indexing ring 26 and withdraws the plunger. A spring- pressed plunger 40, Fig. 1, on the body, engages the holes 28 to lock the ring to the head and may be withdrawn by a sliding cap 42. In Fig. 5, the head is secured in a lathe tail-stock 47 and turned about the pivot 15 to present the bevelgear blank 48, which is mounted on a spigot 49 secured by a set-screw 32 in the work-holder, at the correct angle to a milling cutter 50 mounted on the cross-slide of the lathe. When one side of all the teeth of a bevel gear have been cut, the other sides of the teeth may be presented at the correct radial inclination by adjusting the lever 33 in relation to the work-holder, and locking it by means of the studs 34, the amount of adjustment being shown by the vernier 53. In Fig. 7, inclined splines may be cut in a shaft 57 mounted.between the lathe centres, the tailstock being set over to give the angle of inclination of the splines. The Provisional Specification describes also the provision of a compressed spring behind the head of the screw 45.