Patent GB-403620-A (GB)
Title: Improvements in mortising, boring and similar woodworking machines
IPC: B23Q5/26
Filed: 1932-03-15
Abstract: 403,620. Mortising-machines. BROOKMAN, Ltd., R. S., and BROOKMAN, R. S., Baxter Gate, Loughborough. March 15, 1932, No. 7651. [Class 145 (i).] In a mortising-machine relative movement between the cutter head and workholder is effected hydraulically. The cutter head 20, Fig. 1, is reciprocated vertically by hydraulic power generated by a pump 23 controlled through lever 30 by rod 31 vertically movable on the machine. The rod is spring- biassed downwards, and at its lower end is connected to a pedal 52 pivoted about a horizontal axis for moving the rod 31 vertically, and also pivoted about a vertical axis so that the rod 31 can be rotated by the operator. The cutter head 20 carries three adjustable stops 45, 46, 47 cooperating with a stop 49 on the rod 31 ; at the end of the down stroke the stop 49 is depressed by one of the stops 45, 46 and the pump-control 31 thus moved to a no-flow position ; on releasing the pedal 52, the rod 31 moves down and the cutter head ascends. Reversal at the end of the up stroke is effected by depressing the pedal 52 after the head has been brought to rest by the stop 46 or 47. During cutting the stop 49 is positioned between the stops 45, 46 but the head may be retracted to the position shown in Fig. 1, for tool-changing &c. The stop 49 has vertically offset projections 50, 51, Fig. 8, and the rod 31 is rotated by operation of the pedal 52 to permit the stop 46 to pass from one side of the stop 49 to the other. For controlling the rate of feed, the movement of the rod 31 is limited. The pump-controlling lever 30 carries a roller 64, Figs. 5, 6, positioned between collars 65, 66 on the rod 31. A rotatable disc 67 has progressively larger stops 77- 81, a flat portion 82 and an arcuate portion 83. When any one of the stops 77-81 is brought opposite a projection 71 on the collar 66, upward movement of the rod 31 is limited, thereby determining the rate of downward feed of the head. When the portion 82 is in position a slow descent is obtained, and a pin 84 then engages the collar 65 to prevent the ascent of the head. When the portion 83 is in position, the head ascends but cannot descend. By operation of the pedal 52 the projection 71 can be rotated clear of the projections 77-81, rendering the speed control inoperative and giving rapid descent. The parts 82, 83 are thickened so that the projection 71 cannot be rotated clear of them. Cramps 84a, 90, Fig. 1 are hydraulically operated, being controlled by valves 43, 44, Fig. 9. The cutter head carries a ramp 96 which controls the valves through a pivoted lever 97, push rod 99 and pivoted segment 98, so that the cramps are opened by the head at the top of its travel, but are closed during the remainder of the travel. The segment 98 is eccentrically mounted on a shaft 102 which can be rotated by hand to render the automatic control inoperative, and to maintain the cramps open or closed as desired. In a modification, Fig. 11, adjustable stops 245-7 on the rod 31 co-operate with a stop 249 on the head ; the stop 249 is slidably mounted and has a bevelled end so that on the down stroke it will pass from the top to the bottom side of the stop 246 ; it can be retracted by hand to cause it to pass the stop 246 on the upstroke. Movement of the rod 31 is limited, to control the rate of feed, by adjustable sliders 114, 118 having bevelled ends engaging pins 115, 119 on the rod. In a further modification, Fig. 12, a handwheel 125 carries a helical gear 127 engaging a rack 128 on the head 20. On rotating the handwheel, the resistance to motion of the head causes the gear 127 to move axially, which movement brings the pump into action through a rocker 132 centred by a plunger 136 ; on entering the wood, the resistance is increased, and the gear 127 and hence the pump control, is moved further ; when a stop on the wheel encounters one of the adjustable stops 145, 147 the continued movement of the head causes the gear 127 to move back again, and stop the hydraulic flow. The head is caused to ascend by rotating the hand wheel in the opposite direction. In any of the above constructions, the cutter head may be stationary and the work table moved hydraulically.