Patent GB-296163-A (GB)
Title: Improvements in machines for boring wood and other similar material
IPC: B23B41/06
Filed: 1927-07-04
Abstract: 296,163. Tattersall, H. P. July 4. 1927. Drilling-machines.-In a machine for boring holes in wood or other materials the work is carried by a table which is angularly adjustable in relation to the tool spindle and is also adjustable to and from the spindle, transversely thereto and vertically. The depth of hole drilled is limited by an adjustable stop and the hole may have parallel sides for a given distance and be counterbored at the inner end. The work table 1 is secured to a spindle 2 slidable, and rotatable in a bracket 3 attached to a pillar 4 vertically slidable within a bracket 5, the latter being slidable on a bar 6 secured to the machine, frame 7. The table is adjusted vertically by means of a screw 14 and a hand wheel 46 threaded through a bracket 10 adjustably secured to the pillar 4 at 13 and rotatable in a projection of the bracket 5, the lower end of the pillar being guided by a bifurcated shaft 70 non-rotatably secured to the machine frame. Angular adjustment of the table is provided by a strut 11 attached at one end to the bracket 10 and supporting a lever 45 pivoted to the bracket 3 and carrying a roller 9 on which the table rests, the strut being adjustable in length by a nut 12 engaging right and left hand screwed parts of the strut. The table is adjusted transversely with relation to the tool spindle, 32 by a pinion 60 rotatable in the lever 45 by a hand wheel 62 and engaging a. rack 61 on the under side of the table, and is moved to and from the spindle for feeding by a hand lever 50 pivoted to the bracket a and carrying a link 51 pivoted to the machine frame. The depth of feed is limited by a nut 42 adjustable on a screwed spindle 43 attached to the bracket 5 which contacts with flange 44 secured to the bar 6. For counterboring a hole, the cutter 31 is oscillated in its holder at a predetermined point in the feed of the table so as to cut on a larger diameter, the oscillation of the cutter being effected by an axially sliding plunger 34 in the spindle under the control of a lever 35 adjustably fulcrumed to a vertically adjustable bracket 36 and in contact with a rod 39 which is engaged by a plate 40 attached to the bracket 10, a spring within the spindle serving to return the parts to normal position. An expansible boring tool suitable for the machine and employing an oscillating cutter is described in Specification 289,286. The table 1 carries a fence 15 for positioning the work, blocks 47, Fig. 7, being adjustably attached thereto by screws 48 and carrying spring-pressed plungers 49 against one of which the end of the work may abut, the intermediate, plungers being depressed by the work. A second fence 18, Fig. 2, may be adjusted on the table by a screw 19 passing through a slot in the fence and engaging one of a series of holes in the table. The work is held on the table by a clamping arm 29 operated by a hand lever 30 and adjustable on a, pillar 28 carried by the table. Two vertical supports 22 on the table carry horizontal bars 23 of which the forward one is provided with a graduated scale. Grooved blocks are adjustably clamped on the bars and co-operate with a finger 26 adjustably secured at 27 on the machine frame in vertical alignment with the tool spindle 32. The spindle is driven by a belt from the pulley 54 attached to a pulley 53 rotated by a second belt, the belt forks 58 being operated by a hand lever 57.