Patent GB-140043-A (GB)
Title: Milling machines
IPC: B23Q16/06
Filed: 1919-05-15
Abstract: 140,043. Potter, J. C. March 11, 1919, [Convention date]. Milling - machines. - A milling-machine comprises in a unitary organisation a plurality of units, each having a tool spindle and a plurality of work tables or holders arranged for successive action with such spindle. Specification 22890/20 is referred to. Work tables; work table feeds; stop-motions.-In the form shown, two pairs of parallel work slides 12 are mounted on two turrets 11 arranged on a T- housing respectively beneath one of a pair of tool spindles 14. The turrets are each indexed through half a revolution and locked in position so that a single operator may remove and fix the work on the front tables while the cutters are acting on the rear tables. Each turret is locked by a spring-pressed bolt 30, Fig. 7, which is retracted by a lever 33 operated by a treadle 35 for indexing purposes. When each treadle is operated, its lever 33 engages an arm 36 connected by a pitman 38 and lever 39 to a clutch collar 40 on pulleys 22 so as to connect it to a shaft 21 which by spur gear 20, 19 and bevel gear 17, 16 rotates the turrets, the pulley being driven by belt gear from a shaft common to both parts of the machine and geared to the driving shaft 28 so as to prevent breakage of parts. When each treadle is operated, collars 42 on the locking- bolt pull down a lever 43 so as to free the end thereof or a roller 43<a> mounted therein from one of a pair of notches 45 in the flange 44 on the bevel wheel 16 and so free the turret before rotation and keep the bolt 30 from contact with the turret, the roller bearing against the underside of the flange 44 during rotation. When rotation is completed, the clutch and treadle are returned by the springs 41. The work tables are traversed by racks 46 and pinions 47 mounted on shafts 48 connected together by a clutch 48<a>, the shafts being driven by one of a pair of worm wheels 49 rotated by a worm 50 in a drop worm box 66 pivoted at 55. The worm is driven from the shaft 28 either at high speed by spiral gear 58, Fig. 6, and spur gear 56, 54, 53, Fig. 7, through the shaft 51, or at low speed by spur gear 65, worm gear 64 and spur gear 59, 56, 54, 53 through shafts 52, the gear 56 being clutched to the shaft 51, or the gear 59 to the shaft 52 by a single lever 61 operated by a handle 63. When the work slides have completed their movement, an adjustable stop 75 thereon presses down a spring-pressed plunger 76 into contact with a plunger 77 which is thereupon moved downwards. Rack teeth on the plungers rotate a pinion on the shaft 74 and so swing up the finger 80 to engage a pin 81 on the latch 73 and so remove the notch therein from a pin 72 on an arm 67 projecting from the worm box. At the same time, the pinion on the shaft 74 engages teeth on bar 70 and presses it forwards against the action of the spring 71 until a spring dog 82 engages a notch therein. A stud 68 projecting from the arm 67 which passes into a notch 69 in the bar 70 is thus released from the pressure of the spring 71 and the worm box drops by gravity out of contact with the worm wheel. The treadle is now again pressed to effect the next indexing operation, the spring dog 82 being removed from its notch by a projection on the lever 43, but the spring 71 being prevented from returning the rod 70 and thus lifting the worm box into position again until the indexing operation is completed, by a collar 85 on a rod 86 pivotally connected to the worm box. The latch 73 may have a handle 88 to permit disengagement by hand and the worm shaft may also have a handle 87. Cutter slide and spindle feeds.-The cutter spindles 14, Fig. 4, are mounted in sleeves 109 axially adjustable in vertically adjustable slides 108 by racks 110 and pinions 111 operated by worm gear 113, 114 from hand wheels, the rack fitting a groove in the slide to prevent turning of the sleeve. Driving machine spindles.-The cutter spindles 14, Fig. 5, are driven from the shaft 28 by spur gear 99, 98, 96, 95, 94, the gear 94 being mounted on a shaft 93 connected by gearing 92 to a shaft carrying a spur wheel 90 geared directly to the shaft 28. In order to maintain the meshing of the gears on any vertical position of the cutter spindle slides, the shafts 97 on which the splined gears 98 are mounted pass through vertical slots 106 in the framing 103 and the wheels 95 are mounted on studs 100 carried at one end by yokes 101 pivoted on a sleeve 102 supported by the framing and at the other end passing through slots in the framing curved concentric with the shafts 93, nuts 105 clamping them in their adjusted positions.