GB463204A - Improved dividing head for milling machines - Google Patents

Abstract

463,204. Dividing-heads for milling- machines. MODERN MACHINE TOOLS, Ltd., and SHIPWAY, S. T. Nov. 14, 1935, No. 31501. [Class 83 (iii)] A dividing-head 4 for a milling-machine is operated automatically by movement of the work table 3 the unlocking of the head and the indexing-movement being each effected by one or more cams. The head 4 has bearings 5 for the work carrier which comprises a sleeve 6 slidably connected by a pin 10 to a second sleeve 8 coacting with a split collet 9 which is slidably keyed at 12 to the sleeve 8 and is adapted to grip the work or work mandrel by tightening a nut (not shown) on threads 9c on the collet. A graduated adjusting collar 14 screwing on threads 8a effects a fine axial adjustment of the sleeve 8 which is locked by a nut screwing over the part 8b. Locking of the head is effected by a locking-bolt 16 engaging the indexing-plate 17 and mounted on a lever 15 pivoted at, 15a and actuated through rod 19 by a stationary cam 22 to withdraw the locking-bolt during the first part of the return table travel. During the continued return movement of the table the indexing-movement is then performed by means of one or more fixed cams 23 which actuate a spring returned toothed rack bar 28 engaging teeth on a loose collar 25 which is connected by a pawl 24 to a toothed rim 27 secured on the sleeve 6. The length of the rack is adjustable to vary the amount of indexing-movement. The unlocking and indexing cams may both be secured to a bracket 34 secured to the bed. More than one indexing-plate 17 may be provided, Fig. 3, the locking-bolt being adjustable to coact with any plate according to the spacing required. More than one indexing-cam may be used if considerable angular movement is required and the indexing-movement may be effected on either stroke of the table or partly during forward and partly during return movement.