Patent GB-897001-A (GB)
Title: Improvements in or relating to planing machines
Inventor: BROWN ALEC
IPC: B27C1/10
Filed: 1960-01-29
Abstract: 897,001. Planing wood. SELECTA POWER TOOLS Ltd. Jan. 30, 1961 [Jan. 29, 1960], No. 3260/60. Class 145. A planing machine suitable for attachment to an existing electric motor, for example, the motor of a hand drill, comprises a bracket which is adapted to be secured to the static structure of the motor, a cutting bobbin 13 which is rotatably mounted on the bracket and projects through an opening 21 in a plane surface 6 of the bracket, and a pulley 17 fitted on the bobbin and arranged to be coupled by a belt 18 to a driving pulley 5 fitted on the electric motor. As shown, the bracket is of channel shape and has aligned openings 9, 11 in its side walls 7, 8 for receiving the casing portions 1, 2 of the hand drill which is secured in this position by a split clamping ring 10 surrounding the opening 9; the drill spindle is arranged to project outwardly from the wall 8 and be fitted with the pulley 5. The bobbin 13, which is in the form of a cylindrical hub with two radially-projecting cutters 14, is disposed across the bracket for rotatable movement on an eccentrically-mounted spindle 15, Fig. 7, so that upon rotation of the bobbin the cutters 14 project through the opening 21 in the bottom 6 of the bracket; the bobbin has fixed thereto outside the wall 8 the pulley 17 which is driven from the pulley 5 by the belt 18. One end of the eccentric spindle is rotatably mounted in a hole in the wall 7 and the other end in a bush 23 on the inner surface of a dished cover 25 secured on the outside of the wall 8 to cover the pulleys and belt. A knob 28 has a splined connection with the spindle 15 at the wall 7 to permit rotary adjustment of the spindle to vary the depth of cut of the bobbin, and a lock nut 30 screwthreaded on the spindle serves to lock the latter in adjusted position. When the device is attached as described to the motor casing, it may be passed repeatedly over the surface of a workpiece while the bobbin is being rotated, by using a rear handle 31 mounted on the bottom 6 of the bracket and a front handle 33 mounted on a cover plate 32 by its screwthreaded engagement with an upstanding screwed stem 43 on a boss 42. When used for rebating a workpiece 34 as shown in Fig. 9, a fence plate 35 is mounted on the underside of the bracket in a position appropriate for the desired width of rebate and a shoe 36 is adjustable mounted underneath the dished cover 25 to serve as a stop when the rebate is of the required depth. The fence plate 35 is carried by a horizontal plate 37 which at its outer end has an upstanding lug 38 provided with a forwardly-projecting rod 39 arranged to pass through aligned holes in the walls 7, 8 of the bracket and cover plate 25. The rod 39 also passes through a diametrical hole in the boss 42, Fig. 1, so that, after lateral adjustment of the fence 35 by axial movement of the rod, the latter may be locked in position by screwing the handle 33 tightly on to the stem 43. The shoe 36 is secured to the lower end of a rod 44, Fig. 1, which is adjustable vertically in the cover 25 and can be locked in adjusted position by a screw 45. In the alternative arrangement shown in Fig. 10, the bracket is supported in fixed position above a bench by a pair of supports 49, 50 and the workpiece 48 is planed by the rotating bobbin as it is passed over the surface 6 of the bracket. The Provisional Specification describes also the cutting bobbin as mounted on a bracket which is pivoted on the channel-shaped bracket and is adjustable to vary the depth of cut by screw means acting against a spring.