Patent GB-524551-A (GB)
Title: Improvements in lathes and like machine tools
IPC: B23Q5/18
Filed: 1938-12-22
Abstract: 524,551. Lathes. WARNER & SWASEY CO. Dec. 22, 1938, No. 7254/40. Convention date, Dec. 28, 1937. Divided out of 524,441. [Class 83 (iii)] [Also in Group XXIV] A preselecting mechanism for controlling the speed of a part of a lathe or like comprises a linearly indexible support carrying a number of pairs of movable actuating members. One selected pair of which are brought into operative position by the indexing of the support. In a lathe the bed carries a turret slide 34 and a slide rest 36 provided with a cross slide 38, all the slides being fed from a longitudinal feed shaft 39. This shaft carries on the apron 37 a splined sleeve with gears 40, 40a, engageable directly or, for reversal, with an idler, with a gear 41 splined on a shaft 42 and shiftable by a fork and operating lever 45b. A sliding gear pair 46a, 46b slidable by a rod 94 are selectively engageable with gears 47, 47a on a shaft to impart a two-speed drive thereto. Shaft 48 carries a triple sliding gear 50a...50c slidable by a rod 95 and serving to impart a further three-speed drive, giving six gears in all, to a shaft 52 connected by worm gearing 54 to a friction clutch member 55 through which drive may be imparted to a shaft 56, the clutch sleeve being operated from a lever 57. From shaft 56 the drive is transmitted through gears 58 to a shaft 60 carrying a pinion engaging a rack on the frame to feed the slide rest. The clutch member 55 carries a gear 61 driving a gear 61a connected through a cone clutch and gear 66a to a screw shaft 66 operating the cross slide. When the control lever 57 is raised the clutch 55 is engaged. A stop roll 68 has stops 68a coacting with a stop 69 to move roll 68 endwise at the end of the movement. This causes a cam surface on the roll 68 to disengage a pin from the lever 57 which thereupon drops and disengages the clutch to stop the traverse. For stopping the power feed of the cross-slide, the latter carries adjustable dogs coacting with a pin in the bore of a lever 64 controlling the cross-feed, thus allowing this lever to drop and disengage the cross-feed clutch. The gear control rods 94, 95 project into a housing 96 and carry pins 94a, 95. A pair of rods 97, 98 carry a slidable frame 99 operated from a knob 99b. The frame is fitted with bearing pins 100, 101 which support six pairs of pivoted carrying members 102 carrying co-operating pairs of projections of different lengths. The cam projections selectively coact with the pins 94a, 95a, according to the position of the frame 99 so that by adjusting the knob 99b any of the six gears may be preselected. A slide 104 arranged above the members 102 is recessed to form cam members 104b, 104c and is raised or lowered by a lever arm 106. When the lever is raised, the members 104b, 104c and the slot 103a maintain the members 102 in the position shown in Fig. 9, wherein a gear may be preselected. When the' lever is lowered one pair (corresponding to the preselection) of the member 102 are released so that they turn on their pivots and effect the preselected change, the other members remaining open owing to their engagement with the slot 103a. In another modification of the preselecting mechanism the side walls of the housing 109, Fig. 17, are provided with ribs 110, 110a, which with strips 111 form guides for a frame 112 mounted on a spindle provided with a setting knob 112b. The frame carries six parallel cros rods 113 each fitted with a pair of camblockss 114 carrying projections of varying lengths which coact with pins 94a, 95a, or the gear control rods. A bar 115 in the housing supports slidable shifters 116 having downward projecting tongues 116a co-operating with slots in the cam blocks. In their outer positions the slots in five pairs of these blocks engage projections 110a or the guide ribs while the sixth pairs of blocks are engaged by the tongues 116a projecting through slots in the guide ribs. The blocks 116 are moved simultaneously inwards to move a selected pair of cam blocks by bell crank levers 117 actuated by a nut 118 on a quick pitch screw 119, which is rotated by an arm 120 (or 108) connected through a link 84 to a three-armed lever 85 having pinion its short arms 85b, 85c coacting with extensions on the feed clutch levers 57, 64 and arranged so that when a feed clutch is engaged, the next speed may be preselected and when the feed clutch is disengaged, the gears are shifted to obtain the preselected speed. In some cases the three-armed lever may be replaced by a bell-crank lever 93 connected to a single clutch-operating lever 91, Fig. 8.