Patent GB-1297009-A (GB)
IPC: B23Q16/06
Filed: 1969-06-06
Abstract: 1297009 Milling machines; indexing; milling machine details CALUDON ENG CO Ltd 21 May 1970 [6 June 1969 15 Nov 1969] 28649/69 and 56035/69 Headings B3B and B3K [Also in Division F2] A machine tool includes a rotatable worktable with drive means for selectively driving the table in a series of pedetermined incremental movements or for driving the table in continuous rotation, the drive means being arranged for the incremental movements to be variable in magnitude. As shown, a machine tool for slotting a workpiece secured to a work-table 22, comprises a support 194 mounting horizontal cutter assembly 192 and vertical cutter assembly 193, both of which are identical except in disposition. Each assembly comprises a cutter head 199 or 200 including a spindle-mounted cutter wheel 197 drivable from electric motor 195. The head is movable relative to a cutter body 203 (or 205) (Fig. 3, not shown) under the action of a feed motor 196 driving a screw and nut arrangement. The cutter body is adjustable, along an axis normal to the feed direction of the head, by a manually-operable screw-andnut arrangement. The drive from the motor 196 to the cutter head feed screw can be through alternative gear trains and shafting (Fig. 17, not shown), embodying a pair of electro-magnetic clutches. The arrangement is such that the forward feed through one gear train and clutch is slower than the return feed through the other train and clutch. The drive from the motor 195 to the spindle 198 is by way of a gear train incorporating a pair of interchangeable gear-wheels (Fig. 14, not shown), which enable different spindle speeds to be attained. The spindle can be adjusted axially, and can be removed for changing the cutter wheel.  The cutter head of the vertical cutter assembly is counterbalanced (Fig. 13, not shown), by guided weights connected to the head by pulleys and Reynolds chains. The slideway of the horizontal cutter head assembly incorporates wax pressure pads and a dovetailtype sliding key (Fig. 13, not shown). Various parts of the machine, particularly gearing, are lublicated by lubricant withdrawn from a central tank. The work-table 22 can be continuously rotated or, alternatively, indexed by a Geneva mechanism. A motor 217 (Fig. 6) drives a gear 78 and shaft 77 which can be engaged via clutch 81 with a shaft 82 terminating in a brake mechanism 86. Shaft 82 incorporates a worm which engages a worm-wheel 84 on a shaft 85. The latter and a parallel shaft 95 embodies the Geneva mechanism (Fig. 8, not shown), including a disc-mounted roller pin 88 engageable in slots (93) in disc 92 on shaft 95, a cam 89 on shaft 85 co-operating with a sliding locking plate (97) whose end projection (96) co-operates with slots in a futher disc 94 on shaft 95. Disc 87 includes a trip (83) for tripping a motor deenergizing switch (105). The shaft 95 is releasably connected to an output shaft 106. The latter is connected by gearing (Fig. 11) to a shaft 117. Gear 78 also drives a shaft 125 whose end terminates in bevel gear 127 which drives a similar gear 128 on a sleeve 129; the latter is co-axial with and rotatable about shaft 132 leading to the work-table 22. Shafts 117, 132 and sleeve 129 are axially aligned; adjacent ends of shaft 117 and sleeve 129 have dog-clutch teeth; shaft 132 has a movable dog-clutch member 140 thereon between the adjacent ends of shaft 117 and sleeve 129. 'The dog-clutch member 140 is axially movable manually by a mechanism (Fig. 10, not shown) which locks to prevent undesired movement. With member 140 engaged with sleeve 129, the shaft 132 is rotated continuously from the motor, while with member 140 engaged with shaft 117 the worktable in indexed. The work-table can be rotated manually independently of the Geneva mechanism by releasing shaft 95 from shaft 106. The gearing between shafts 106 and 117 is interchangeable to provide variable indexing movements. The work-table shaft drives the work-table through a worm drive incorporating a manual adjustment to prevent backlashing (Fig. 5, not shown). Specification 1,297,010 is referred to.