Patent GB-354944-A (GB)
Title: Machine for drilling and finishing blind holes, especially tapped blind holes
IPC: B23B41/00
Filed: 1930-07-04
Abstract: 354,944. Drilling and tapping machines. FAUDI, F., 190, Hansa Allee, Oberkassel, Dusseldorf, Germany. July 4, 1930, No. 20308. [Class 83 (iii).] In a machine for drilling, tapping, &c., blind holes in work-pieces, a work-turret is arranged above a number of toolspindles which enter the work from below, upwardly, so as to allow cuttings to escape freely from the blind holes. The upwardly directed tools all perform different operations such as rough and finished drilling, tapping, &c. The tool-spindles 21 are journalled in a bracket 29 on a pillar 5 and each is rotated by a bevel pinion 19 splined thereon and further bevel gears 16, 13, driven through gears 11 from a crossed or open belt and a pulley 9 on the shaft 6. The spindles are fed simultaneously by a cam 38 rotated through spur gearing 44 and a worm drive 45 from the shaft 6, the cam acting on a roller 37 on a bracket 33 which is vertically slidable on guides 34 and carries a boss 32 for each spindle. A sleeve 31 is clamped to each spindle by nuts 29 and rotates freely within its boss 32. The work pieces x, which are shown as the sockets of ball joints which are to be drilled and tapped, are carried in a turret 50 rotatable in guides 57, 58 supported by pillars 60 from a tray 61 adapted to receive the cuttings &c. When one drill and one tap only are used the turret has three work-holders 54, one for each working station and one for removal of the work, the holders comprising sleeves 45 having a bevelled socket at the lower end into which a conical split collet 51, splined at 56, may be drawn for gripping the work by means of a nut 52 screening on the collet. A box-spanner 81a attached to a stem 81 rotatable and slidable in a bracket 80 is provided for rotating the nuts 52 and is normally pressed upwards by a spring 83 but may be depressed on to a nut and rotated by means of a hand-wheel 82. A radial bolt 62 co-operates with index notches 64, Fig. 2, on the turret and is pressed inwards by a spring 63. A ring 65, rotatable on the turret, carries a spring-pressed pawl 67 co-operating with ratchet recesses 68, a handle 69 being pivoted at 70 on the ring and carrying a slotted arm 72 adapted to embrace a pin 73 on the bolt 62. Oscillation of the handle 69 in a clockwise direction in Fig. 2 first rocks the handle about its pivot and withdraws the bolt, whereupon further oscillation rotates the ring 65 and the turret and causes the arm 72 to release the pin 73 to allow the bolt to enter the next notch 64. A shoulder 74 on the handle limits its rotation relatively to the ring 65. A rod 75, attached at 76 to the bracket 33 which feeds the tools, is moved upwards with the tools and enters a recess 77 in the bolt 62 to prevent its retraction during a cutting operation. The cam 38 is designed at a to give a dwell to the tools in the lower position, at b to give a rapid approach towards the work, at c to give a slow-cutting feed and at d to give a rapid retraction in the case of a drill, reamer, &c. In tapping, the tool is retracted by reversal of the drive and the portion d of the cam is not utilized. To revolve the turret more than one station the ring 65 must be returned to normal position, whereupon the arm 72 will again engage the pin 73.