Patent GB-222138-A (GB)
Title: Improvements in boring machines
IPC: B27C3/06
Filed: 1924-09-19
Abstract: 222,138. Lacey, E. G. Sept. 20, 1923, [Convention date]. Mortising. - In a drilling - machine particularly for drilling dowel holes in wood for furniture &c. but which may be used for mortising, the dril-spindle is rotatably mounted in a sleeve longitudinally slidable in a member which is transversely movable so that a projection thereon and movable therewith may be made to engage spaced openings in a gauge-bar to form spaced holes. The transversely movable member may comprise a lever either pivoted on a stationary shaft or provided with a toothed quadrant rolling on a fixed rack so that the spindle may move transversely in a straight line. The drill-spindle 36 is rotatably mounted in anti-friction sleeves 39 splined to a similar sleeve 46 in a boss 33 on the lever 17 pivoted on a tubular shaft 16, and is fed by a hand-lever 48 and linkage 50, an anti-friction thrust bearing 41 being provided and a spring 48<11> retracting the lever 48. The spindle is rotated by a pulley 20 on the shaft 16 and driven through fast and loose pulleys 21, and main belt 32 being controlled by striking-gear 25 actuated from a pedal through a rod 26 inside the shaft 16. The work is supported by a table 62 pivoted to a bracket 61 adapted to slide on a vertical guide 60, the inclination of the table being variable by means of a strut 69 clamped at 71 to the bracket and vertical adjustment being provided bv a hand-operated screw 63. A gaugebar 52, Figs. 3 and 6, is detachably secured to the machine frame at 56 and is provided with notches 53 adapted to be engaged successively by a feather 45 on the spindle sleeve to position the spindle laterally. The notches are flared and the feather is tapered at the end to facilitate engagement. Springs 54 are provided on each side of the lever 17 for cushioning its lateral movements. Further spacing of the work is provided for by blocks 90 adjustable along a graduated fence 73 attached to the table and carrying plungers 91 which are pressed forwardly by springs 93, Fig. 10, so that they may be depressed when the work engages the fence but will project outwardly as the work is moved along to engage its end with each plunger in turn. The plungers may be grooved to coact with balls and springs to retain them in the retracted position. Plungers 75, Figs. 2 and 3, are attached to laterally-adjustable bars 76 and are normally pressed by springs 77 through slots in the table. A protractor 100 provides for setting the work angularly. A clamp arm 82, angularly adjustable on a pillar 84, secures the work to the table when depressed against a spring 86 by a pedal 87 connected to the pillar. To enable vertically-spaced pairs of holes to be drilled, the nut 66 engaging the table-adjusting screw 63 is slidable in a bracket 101 and is pressed upwardly by a spring 115. A rod 103 secured to the nut is engaged by a spring bolt 106 to secure the table until the bolt is withdrawn by linkage 109 connected to the feed-lever 48, lost motion being introduced a,t 109<1> to ensure that the spindle will be fully retracted before the bolt is withdrawn. On withdrawal of the bolt the table may be depressed by the clamp 82, the motion being limited by a stationary adjustable rod 112 carrying a scale and pointer 114. Nuts 103<1> limit the return of the table by the spring 115. An L- shaped bar having an adjustable abutment may be secured in various angular positions in one of the blocks 90 to support part of the work above the table. When the lateral adjustment of the drill-spindle is required to be in a straight line the lever 17, instead of being pivoted at 16 is provided at the lower end with a toothed quadrant concentric with the spindle and adapted to roll on a fixed rack. The machine can be employed for making rectangular holes or mortices bv substituting a combination hollow square chisel and bit for the drill and round ended mortices may be made by a shaped tool The mortising tools may be fitted to the spindle 36 or to the sleeve 39. The spindle may be mounted on a member sliding on transverse tracks or rails.