Patent GB-190123406-A (GB)
Title: Improvements in Drilling and Tapping Attachments for use in Connection with Drilling and like Machines.
Filed: 1901-11-19
Granted: 1902-07-31
Abstract: 23,406. Lake, H. H., [Seneca Falls Manufacturing Co.]. Nov. 19. Drilling; tapping.-Relates to an attachment or tool-holder for an ordinary drilling-machine to enable it to perform drilling or tapping. A shank c<2> fitting the machine spindle A has secured to it a sleeve C journalled in a casing B, held against rotation by a chain b<2> or other suitable device. A toothed wheel K on the lower end of the sleeve drives a vertical side shaft l<5>, mounted in the casing and gearing through a studpinion l<9> with a wheel L revolving in the bottom b<1> of the casing. The tool-spindle D carries friction discs F<1>, F<2>, the upper one being fixed to the spindle, and the lower one being mounted on a sleeve G feathered on the spindle. Between these discs is a driving-disc F with a flange H carrying a ring i with pins j<1> engaging in recesses in a ring J, which has pins k<2> capable of engaging with pins k<1> on the wheel K. When the machine spindle is lowered to bring the tap d<1> into contact with the work, the tool-spindle is pressed up, and is then driven in the forward direction through the pins k<1>, k<2>. By raising the machine spindle the casing is raised, disengaging the pins k<1>, k<2> and bringing pins l<3> on the wheel L into engagement with pins l<4> on the disc F<2>, thus driving the tap in the opposite direction to withdraw it. The thrust of the tool-spindle is taken up by a collar E screwed on the spindle and bearing against the bottom of the casing and also against the end of the sleeve G. The frictional bite of the discs F<1>, F<2> on the disc F may be adjusted for various sizes of tools by turning the collar E to raise or lower the sleeve G carrying the disc F<2>. This rotation of the collar is effected by a worm carried by the collar and engaging worm teeth e<2> on the sleeve, the worm being turned by a milled head. To enable the rotation of the tap to be stopped at any desired depth of hole, springs k<3> are inserted in the recesses in the ring J with which the pins j<1> engage, allowing the ring to be pressed down by a fork m<1> to disengage the pins k<1>, k<2>. This disengagement is effected automatically by the action of a tappet n, Fig. 8, on a vertical rod M carrying the fork. The tappet is carried by a wheel N loose on a shaft nl driven by a worm-wheel o and worm thread o<1> on the flange H. The wheel N is driven by a roller clutch p on the shaft n<1> when the tap is entering the work, and is driven in the opposite direction, when the tap is being withdrawn, by a ratchet-wheel Q on the shaft n<1> engaging a pawl on the wheel N. After a certain number of turns of the tap in the reverse direction, the pawl is tripped and held out of gear by a pin w carried by a dial plate T. On bringing the tap into a fresh hole, the clutch p immediately commences to drive the wheel N, and, after the same number of turns, the tappet n strikes a lug m<5> on the shaft M, depressing it and stopping the rotation of the tap. The dial plate is set to a mark on the casing, and locked by a set-screw so that the tap may make any desired number of turns before being automatically stopped. The wormwheel o is coupled to the shaft n' by an internal key o<2>, operated by a rod o<5>. When the tap is replaced by a drill which is to be constantly rotated in the forward direction, the worm-wheel o is disconnected, and the wheel N turned backwards by means of the dial pin w engaging the pawl until the tappet n lifts the rod M to bring the pins k<2>, k<1> into engagement, when the dial plate is locked.