Patent GB-708411-A (GB)
Title: Improvements in or relating to universal router
IPC: B23Q1/00
Filed: 1952-07-10
Abstract: 708,411. Copy-milling. ONSRUD MACHINE WORKS, Inc. July 10, 1952 [Jan. 31, 1952], No. 17408/52. Class 83 (3). [Also in Group XXIII] A pattern-controlled routing machine comprises a carriage 8 straddling a work-bed 28 and movable along it by a motor 10 driving a rack and pinion 11, 12 through a belt or chain and a worm drive, an annular support 1 traversable across the carriage 8 by a motor 14 and lead screw 13 and rotatable on its axis by a motor 4 and gearing 5, 6, and a routing head 2 carried within the annular support on an arm 18 pivoted on a bracket 19. The pattern follower comprises a collar 27 surrounding the cutter spindle 16 and engaging the pattern 31 mounted above the work 3. The motors 4, 10, 14, are variablespeed, direct-current amplidyne-controlled units and are controlled to cause the routing head to move round the pattern and work by, in the case of the longitudinal and traverse motors 10, 14 a joy-stick 129 on a controller 128, and in the case of the annular support motor 4, by a selsyn transmitter 55 having a handle 57 which, when rotated, controls the motor 4 through a selsyn receiver 58 to give the same angular movement to the annular support. During the copying movement a fluid-pressure cylinder 62, sliding on a piston rod 60 fitted across a chord of the annular support and having a pair of flanges 66 engaging a tooth 67 on the routing head, pivots the arm 18 and presses the follower laterally into engagement with the pattern with a yielding force substantially normal to the line of the pattern. The routing head 2 and the follower bracket 24 are independently movable up and down by, respectively, a pair of yoked fluid-pressure cylinders 20 and a cylinder 26. The annular support 1 is mounted in a frame 34 by an oil-bathed bearing 43 on the gear ring 6 and a pair of uprights 47 support a bridge member 48 carrying a distributor 49 having a rotary shaft 68 with collector rings 74 and brushes 75 for supplying current to the motor 4, and a conical valve-type distributor 78 for supplying compressed air to the cylinders 20, 26, and for supplying lubricant and compressed air to the follower bracket 24 for lubricating the cutter and blowing away chips. Adjustable stops are provided for limiting the movements of the follower, routing head, lateral-motion cylinder 62 and the motors 10, 14. Compressed air from a supply 97 is connected to a master valve 99, which is of the reciprocable piston type and is controlled by an operating valve 109, the latter preferably being footoperated. From the master valve, lines 100, 101, are connected to the ends of the follower cylinder 26, and from the line 100, a line 102 leads to a master valve 103 controlled by an operating valve 110 and thence to the routing head cylinders 20, and a further line 106 leads through a reducing valve 107 and blow-off valve 108 to one end of the lateral-motion cylinder 62. Flow control valves 117, 118, cushion the downward movements of the pistons 20, 26. The valve 109 is operated first so that the follower is lowered to the pattern level and reduced pressure is supplied to the cylinder 62 to move the follower laterally at a slower rate to engage the pattern. The valve 110 can then be operated to lower or raise the cutter independently of the follower but, to prevent the follower being raised without also raising the cutter, an interconnecting line 119 having a non-return valve 120 is provided.