Patent GB-340477-A (GB)
Title: Drilling and tapping machine
IPC: B23B39/00
Filed: 1929-08-23
Abstract: 340,477. Drilling and tapping machines. CINCINNATI BICKFORD TOOL CO., Oakley, and KLAUSMEYER, D. C.; 2980, Springer Avenue, Hyde Park, both in Cincinnati, U.S.A. Aug. 23, 1929, No. 25740. [Class 83 (iii).] A drilling and tapping machine comprises a standard or support having a bracket for a rotary tool spindle adjacent the upper end at one side thereof, a driving motor adjacent the upper end on the other side and interchangeable or replaceable toothed gears forming a driving connection between the motor and spindle. The motor may be adjustable in position to allow different sized gears to be used. The machine comprises a pillar 2 Fig. 1, supported on a base 1, and provided with a cylindrical portion 3 on which is vertically adjustable a bracket 4 carrying a work-table 5. The driving motor 7 is attached to a bracket 8 which is vertically adjustable on the pillar by means of a screw 13 engaging a lug 14 thereon and is secured thereto by bolts passing through slots in the bracket. This vertical adjustment of the motor allows different sized driving gears to be attached to its shaft. A machined facing 18 on the pillar is adapted to receive one of a number of casings 19<d>, Figs. 1 and 5, 19<a> Fig. 2, or 19<c> Fig. 4, according to whether the machine is desired to perform high or low speed drilling or tapping. For low speed drilling the casing 19<c> Fig. 4, carries reduction gearing 31, 20, 24 for driving the drill spindle 6 from a pinion 17<b> on the motor shaft, and for high speed drilling the gearing is arranged in another head for driving the pinion shaft 21 directly from the motor pinion. The drill spindle is splined within the hub of the bevel gear 24, and further speed variations may be made by changing the motor pinion 17<b>. Driving and reversing devices.-For tapping, the motor pinion 17<c>, Fig. 5, drives a bevel gear 23 which continuously rotates gears 36, 37 in opposite directions. Either of the gears 36, 37 may be coupled to the sleeve 33, splined to the spindle 6, by means of one of the friction clutches 38, 39 which are expanded by an axially slidable cam bar 40 attached to a sliding collar 43. A hand lever pivoted at 45 to the casing carries a yoke for actuating the collar 43. Feed-motions ; tap spindle feeds.-The feed mechanism for the tool-spindle 6 is carried by a bracket 51, Figs. 1 and 2, adjustably secured in one of three positions to a face 49 on the pillar 2 by means of bolts 55. The spindle 6 is rotatably journalled in a quill 52, bearing a rack 59 engaged by a pinion 58 on a shaft 57 which may be rotated by hand levers 60. The machine may be provided in this manner for hand feed only, but when power feed also is required a casing 61 is secured to machined surfaces on the bracket 51 and carries bevel gears 64 driving the pinion 58 through a worm and wheel 63, 63<a>. The bevel gears 64 are rotated through a telescopic shaft 66<a> 66<b> and a change speed gear 71 from the tool spindle. A pinion 27 on the tool spindle drives through gearing 69 a nest of gears 71<a> .... 71<e> permanently in mesh with gears 72<a> ... 72<e> loosely mounted on the shaft 66<a>, any one of which may be coupled thereto by means of a key 73 pivoted to a bar 76 provided with a circular rack. A pinion 77 engages the rack bar 76 and is itself rotated by a second rack bar 79, Fig. 1 and a hand lever 81, a spring pressed detent being provided to co-operate with notches in the bar 79 and retain the lever in any one of its five positions. Balancing parts.-The tool spindle is balanced by means of a weight 84, Figs. 1 and 2, connected to the quill 52 by a chain &c. 85 passing over pulleys 86, 87, Figs. 4 and 5, mounted on the casings 19<c> &c. and on the pillar respectively. The lower end of the chain carries a block 92 engaging a small aperture 90 in the weight, a larger aperture 91 being provided for insertion of the block and an opening 88 in the pillar giving access to the weight.