Patent GB-222318-A (GB)
Title: Improvements in or relating to drilling or like machines
IPC: B23B39/24
Filed: 1923-10-05
Abstract: 222,318. Hey, G. Oct. 5, 1923. Drilling-machines. - In a drilling or like machine of the type in which the feeding means are adapted to operate at intervals so as to tend virtually to advance the drill relatively to the work and in which an automatic selecting mechanism is provided to render the advance operative or not at each feeding interval, the selecting mechanism is constructed to offer a choice of settings whereby the virtual advance is rendered operative as desired at regular or irregular intervals in a sequence. In a multiple-spindle drilling-machine, Fig. 1, the drill spindles 14 are carried by a cross frame 13 which may be vertically adjustable on the uprights 12. The selecting mechanism comprises a drum 39 adapted to receive pegs 87 .arranged in rows corresponding to the row of drills. The bearings 36, 37 of the drum are mounted on vertical rods 31, 32 passing through the columns 12 and screwed at the lower .ends to coact with nuts 54, 55, Fig. 4, driven by a shaft 50, gears 61 and a clutch 51 on a main driving-shaft 27. The return of the selecting drum is effected by any known form of reversing gear, such as an epicyclic gear in the main driving-pulley. The drum is rotated intermittently between its advancing movements by means of a worm and worm-wheel 41, Fig. 1, driven through a vertical shaft 42, bevel gears 46, Fig. 4, gears 50 and clutch 51. Each drill-spindle is mounted in a cylinder and carries a piston which is acted upon by compressed air or other fluid to return the spindle, the pressure being supplied by conduits 73, 74, Fig. 1, and a valve operated by a lever and rod 82 attached to a bell-crank 83, Fig. 4. The work-table 15 is traversed by a screw 18 rotated intermittently through worm-gearing 20, bevels and skew gearing 25 and a clutch 26 on the main drive shaft 27. The clutches 26, 51 and the bell-crank 83 are operated by linkage 29, 52, and 85 from cams 30, 53 on the shaft 27. In operation, the work is intermittently advanced by the screw 18 and after each movement a selected number of drills is advanced by the stops 87, the drills being continuously rotated by a worm 66 driven at 65. The drills which are not in use project into openings 86 which do not contain stops, or the length of the stops may be such that the spindles are always clear of the drum. The top of each spindle carries a ball thrustbearing 72. The stops may be a tight fit in circular holes in the drum as shown, or may enter axial T-shaped grooves. When two or more rows of drills are used, Fig. 10, the selector mechanism consists of a chain 94 encircling flat-sided rollers 95, one roller carrying a sprocket-wheel engaging the chain and being rotated intermittently by the worm-gear 41. Both rows of spindles 14, 90 are rotated by the worm 92 and they may be returned after drilling by the fluid-pressure system 74 or by springs 93. The drills in adjacent rows may be arranged in line or staggered to enable holes to be drilled close together. The setting up of the stops by means of a chart is facilitated if, e.g. the longitudinal rows of holes in the drum are numbered and the circumferential rows lettered. In modifications, the drill-spindles may be arranged horizontally or inclined, and they may remain stationary while the work-table is fed by means such as the rods 31, 32. When used for tapping, yielding-feed chucks are employed. Specifications 5480/15 and 110,560 are referred to.