Patent GB-191008970-A (GB)
Title: Improvements in or relating to Machines for Boring or Drilling Conical Holes or Cavities.
IPC: B23B41/06
Filed: 1910-04-13
Granted: 1911-04-13
Abstract: 8970. Lanston Monotype Corporation, [Bancroft, J. S., and Indahl, M. C.]. April 13. D r i l l i n g - machines; lathes; chucks. - In an automatic machine, of the class described in Specification 24,616/05, for drilling conical holes in blanks such as the type matrices shown in Fig. 46 of Specification 8633/99, the blanks are fed to a rotating chuck and are operated upon b y a number of stationary self-centring cutters mounted upon a two-way movable slide. The machine contains (1) blank-feeding and chucking means, and means f o r p r eventing the closing of the chuck and for stopping the machine if the feed movement is not completed; (2) means for mounting t h e cutters so as to render them self - c e n t r i n g ; (3) a sequence indicator and locking - means for controlling the straightline-turret movement of the cutter slide; and (4) means for stopping the machine if a drill breaks. (1) The blanks are fed in a supply galley 70, Fig. 12, and delivered by a pusher 80 into the chuck 8, the position in the chuck being determined by a gauge rod 15; the cutters 33 to 36 then operate in turn and the blank is ejected by the rod 15 into a passage 90 in the cutter slide to be driven by a pusher 85 into the receiver galley 71 when the cutter slide moves back. The chuck comprises a head 6 provided with a hardened bushing 7 provided with a slot for a clamping jaw 9, Fig. 13, mounted on a spring 10 and closed by a spring- pressed bevelled sleeve 11. The chuck-spindle 5 is driven for drilling by a pinion 17, Fig. 7, driven from the main shaft and in a reverse direction by a pulley 18 to bring the chuck against a stop into the required angular position for blank-feeding; the clutch 20 is spring-pressed to normally put the reverse drive into operation, and is moved by a camoperated lever 135 to engage the pinion 17. This lever is bifurcated and has contacts 138, 139 which will release the clutch from pinion 17 if it sticks. To prevent the chuck from operating until the blank is fed in, the chuck-opening arm 174, Figs. 12 and 29, is connected with an arm 175 adapted to engage a latch 179 normally withdrawn by a lever 180 connected to the blank-feed pusher 80; a latch-ended link 186 is connected to the latch 179 and also to the rod 176 which descends to allow the chuck to close so that if the latch is not withdrawn a lever 189 connected to the main driving clutch will be depressed and thus stop the machine. (2) The cutters have flattened shanks, and are mounted in holders 41, Fig. 12, with rear extensions 44 with flattened sides forming a loose open bearing in slots in a back upright 27. The front upright 28 carries vertical slides 37 through horizontal slots in which the flattened shanks of the cutters pass loosely. The cutters thus can adapt themselves to the axis of the chuck, but as soon as the cutters bite on the work the slides 37 tilt slightly on the guides and bind, thus tightly fixing the cutters and preventing the formation of an eccentric hole. (3) The sequence indicator and locking-means, Fig. 18, comprise a block 50 with transverse channels 51 and a longitudinal slot 52 for a lock-out bar 53; this bar has slots with inclined edges 56, the smaller width of the slots being equal to the channels 51 and a dependent arm 54, Fig. 7, on the tool-slide passes through one of these slots and sets the next one ready for the next reciprocation. If, however, the transverse-moving means has moved the slide more or less than one step, or the axial movement of the slide was arrested in the previous movement, the arm 54 will be unable to enter the slot and the action of the machine will thus stop, The locking-bolt 62 for the slide 26 is formed of two sections with an incline 65, the result being that the bolt first enters the slot and the parts then move relatively and accurately position the slide. A number of gauge pins are mounted on the toolslide, and these engage an adjustable screw 58, Fig. 7, to limit the axial movement of the slide, which is pressed forward by cam-operated levers with an interposed spring and is spring-returned. (4) To stop the machine if the drill 35 breaks, a feeler 210, Fig. 24, connected with and controlling the driving clutch mechanism. makes contact with the drill as it is withdrawn ; it is carried by a link 211 pivotally attached to an arm 120 connected to means for opening the driving clutch, and has a notch 213 opposite which a pin 216 on the tool-slide comes when the drill 35 is about to operate. The link is released on the backward movement, and normally is supported by the drill, but if the latter is broken, the notch 213 falls over the pin 216 and the lever 120 is thus operated to stop the machine on the next transverse movement of the slide. Drills.-The drill 35 is provided with a secondary cutter for countersinking.