Patent GB-336052-A (GB)
Title: Improvements in and relating to radial-arm drilling and tapping machines
IPC: B23B39/12
Filed: 1929-08-23
Abstract: 336,052. Cincinnati Bickford Tool Co., and Klausmeyer, D. C. Aug. 23, 1929. Drilling-machines.-A radial-arm drilling and tapping machine has an oil-tight gear-box mounted on the head slidable along the arm and giving thirty-two speeds in two directions to the drill-spindle, the gearing being arranged in three change-gear sets giving four, two and four speeds respectively and the gear-box being formed in sections whereof one contains two gear sets and another contains the drill-spindle. The drill-head comprises casing sections 1, 2, Fig. 1, joined along the surface 5-5, and slidable along guides 9, 10 on the radial arm 8. A shaft r journaled on the arm 8 is driven from a prime-mover and carries two bevel gears, either of which may be clutched to the shaft by a clutch x, hand controlled at 21, so as to cause a first shaft 13 to be rotated at a constant speed in either direction. Four speed changes are provided between the shaft 13 and a second shaft 34, by means of gears 24 - - 27 secured to shaft 13 and two axially displaceable splined units 32, 33 comprising gears 28 - - 31. A two-speed change is provided between shaft 34 and a third shaft 38 by means of two gears 43, 44, fixed to shaft 34 and a pair of gears 45, 46 splined to the shaft 38 which has also splined thereon gears 48, 49 adapted to engage gears 50, 51 secured to a fourth shaft 52. A sleeve 59, within which the drillspindle S is splined, is rotated from the shaft 52 by a gear 64 splined thereon which may either be caused to mesh with gear 51 or be displaced axially to engage internal teeth 63 on a gear 62 constantly in mesh with a gear 56 secured to the shaft 52. Driving machine - spindles; clutch - operating mechanisms.-The gear units 32, 33 are displaced axially by yokes 91, 92 respectively, Figs. 1 and 2, the yokes being slida.ble on vertical rods 93, 93<a> and each being provided with a rack 89, 90 respectively. A control shaft 76 carrying a toothed segment 88 is slidable axially to cause the segment to engage either rack and is rotatable to displace the racks and move the gears. A hand lever 75 on the rod 76 projects through an H- shaped slot 87 in a casing 80, movement along the limb 87 causing axial displacement of the rod and movement along the limbs 85a, 86 causing rotation of the rod. A U-shaped bracket 94, Fig. 2, is mounted on the rod 76 to move axially therewith and is prevented from rotating therewith by a square pin 97 engaging a slot 94<b>. Two teeth 95<a>, 96<a> on the bracket engage the racks 89, 90 to prevent movement thereof when the segment 88 is in the neutral position shown, but are moved out of engagement with the rack which is meshed with the segment on axial displacement of the rod 76, the other tooth still remaining in mesh with the other rack. Long teeth 89<a>, 90<a>, are provided at the ends of each rack to limit the movements of the yokes. The gears 45, 46 are displaced axially by a yoke 100, Fig. 1, carrying a rack engaged by a toothed segment 102 on a shaft 103 which is oscillated by a hand lever 107. The gears 48, 49 are displaced by a yoke 111, Figs. 1 and 5 carried by a lever 109 pivoted at 110 and rocked by a slotted bracket 114 which is cut away as shown to clear gears 62, 64. The bracket is guided at 117, 118 and is provided with a rack 119 meshing with a pinion 120 loose on a shaft 122 but secured to a hand lever 123. The gear 64 is displaced by a yoke 124 on a bracket similar to the bracket 114 and is actuated by a rack 128 and pinion 129 secured to the shaft 122 which carries a hand lever 130. The levers 75, 107, 123 and 130 are all arranged at the front of the drill-head within easy reach of the'operator as shown in Fig. 1. Feed-motions; spindle-mountings.-A pinion 65 on the sleeve 59 within which the drill-spindle S is splined drives, through gearing (not shown), a worm-wheel 66 which may be connected by a clutch 68 to a shaft 69 carrying a pinion 70 meshing with a rack on a sleeve 72 which is mounted between ball-bearings 73, 74 on the drill-spindle but is not rotatable therewith. The spindle and gear shafts are carried in the bearings shown in Fig. 1, which are arranged in this manner for case in machining. A casing 4 secured to the bottom of the casing 2 forms an oil sump 131 from which a pump P, continuously driven from the shaft 34, draws oil by a pipe 132 and supplies it by a pipe 133 to a nozzle 134, from which a stream of oil proceeds over the gears and through the bearings back to the sump.