Patent GB-477773-A (GB)
Title: Improvements in or relating to multiple-spindle drilling machines and like machine tools
IPC: B23B41/00
Filed: 1936-07-02
Abstract: 477,773. Drilling-machines. GIMSON & CO. (LEICESTER), Ltd., and CLARKE, G. July 2, 1936, No. 18391. [Class 83 (iii)] In multiple - spindle drilling - machines and like machine tools having a number of axiallymovable tool spindles arranged in a row, the spindles are capable of being moved bodily in a lateral direction so that some of a row of holes can be formed in a single operation, and then the spindle can be moved laterally in one or more stages to drill the other holes required in the row. The drills rotate in bearings 2, 3 on brackets 4 carried by saddles 5 connected by links 8 and movable on a transverse slide 6. The brackets can be adjusted relative to the saddles and secured by bolts. The saddles 5 are moved transversely by a screw 15 which is supported in a side member 7 and bracket 18, Fig. 6. An index plate 19 with holes 20 is mounted around the screw. The boss 21 carries a key 23 which engages a slot 24 in an adjustable handle 22 which is rigidly bolted thereto. A spring-pressed pin 26 can engage the holes 20. If the plate contains an additional series of holes, the handle may be adjusted transversely. An angularlyadjustable, tapered stop 27 held by a screw and a spring 30 is arranged between the boss 21 and the plate 19. When the handle is turned quickly the pin 26 will override the stop 27, but when turned slowly it will engage the stop and enter the hole 20. Alternative indexing, suitable for semi-skilled operators, consists in substituting for the adjustable stop 27 and pin 28 a notched bar 32, Figs. 1, 7, and a spring-controlled element 33. The bar is disposed horizontally at the side of the machine and is attached by screws 34 to one of the saddles 5. The bar has notches 36 . . . 36<1>, 36<11> ... 36 at the top and bottom respectively, corresponding to the pitch of the holes to be made in adjacent lines in the plate. The bar passes through a bracket 35 which carries a hand-operated spring-pressed lever with fingers at the top and bottom which engage one or the other line of notches. Different bars are used for drilling rows of holes of different pitches. The work a is supported on rollers 46 on spindles 47 with sprockets 49 connected by chains and hand-operated by a wheel 51. The side of the plate a has attached to it a loose scale 62 with spaced transverse lines. Adjacent the plate is a three-pronged indicator. The prongs are of slightly less pitch than the holes to be drilled to facilitate accurate spacing. Alternatively, the edge of a hand-controlled lever may enter grooves in a scale mounted on the plate. Guides 58 may prevent lateral displacement of the plate. The drill spindles are rotated from a main transverse shaft at the rear of the drill head, through change-speed mechanism which rotates a drum 62 from which the spindles are belt driven. The drill spindles are simultaneously fed by a shaft 67. The shaft 67, Fig. 6, may be rotated by a hand lever 69 or automatically. The part carrying the spindle 67 carries a sleeve 72 forming part of the drum 21 of a clutch. This is continuously rotated through worm gearing 73, 74 driven from the main shaft through belt gearing and, if desired, change-speed gearing. The friction shoe 79 is connected to the shaft 67, and can be brought into contact with the rotating drum on laterally moving the handle 69 through bevel-ended rods 87, 84 and a lever 82 mounted upon a pin carrying a cam which expands the shoe against the resistance of a spring. The manner in which the machine is used to drill rows of staggered holes in a plate is described. Reference has been directed by the Comptroller to Specifications 11052 /94, 19977/94, [both in Class 83], and 223,431, [Class 83 (iii)].