GB585045A - Drilling machine - Google Patents

Abstract

585,045. Drilling-machines. PRIEST, C. H. July. 6, 1944, No. 12941. [Classes 83 (ii) and 83 (iii)] Making screws.-In a machine for cross-drilling the heads of slotted screws to receive a locking-wire, the screw is clamped by means of its slot in an adjustable jig-bush and is ejected by compressed air that also removes the cuttings. The jig consists of a bush 10 with a part flange 17 provided with a number of radial holes 18 brought in turn into line with the drill 6 as the previous hole becomes worn. The bush is held in the split end of a slide 5 by a screw 8, and it is tapped to receive an exchangeable work-holding bush 14 drilled according to the screw size and adjustable by a screw-driver slot 16 to bring the screw head into correct relation to the drill. The slide 5 moves in guides on the top flange 19 of an I-beam forming the main frame member, this flange and the web 22 being cut away as shown in Fig. 2. The slide is fed by a hand lever 50 clamped on a spindle 51 that also has an arm that operates the stem of a normally spring-closed air valve 64 to open the valve at the end of the return stroke of the slide admitting air at 62 to eject the blank that is conducted by a curved guide 70 to a receptacle 71, and at 73 to blow away the cuttings. The blank, inserted by hand, is clamped by a blade 11 that enters the slot in the head and is carried by levers 56 straddling the slide 5 and pivoted to it at 58. A cross-pin 59 on the levers is connected to tension springs 60 anchored to the web 22 at 61. As the slide 5 returns, the pin 59 contacts the edge 23 at the cut-away part of the web and lifts the blade clear of the slot prior to ejection. On the forward stroke, the pin 59 remains in contact with the edge 23 until the blade seats in the slot in the blank after which the pin leaves the edge stretching the springs and increasing the clamping pressure. The drill is driven from an electric motor 41 through belts 38, 32 and a countershaft 34. The spindle housing 28 is carried on a part of the top flange 19 and this flange may be stiffened by struts 49 beneath both the drill and the work-slide. Lubricant is supplied to the drill from a container 42 by a drip pipe 44 and is collected by a tray 48 supported by a spacer 47 from a base-plate 45 with angle-iron feet 46.