Patent GB-1160177-A (GB)
Title: Automatic Bending Brake
Inventor: WILSON WALTER WIENER
IPC: B21D5/04
Filed: 1967-10-03
Abstract: 1,160,177. Angular bending. S. P. MIDOUHAS. 3 Oct., 1967, No. 44951/67. Heading B3E. An automatic machine for bending flanges along opposed edges of a rectangular metal sheet comprises an elongated frame supporting a driven conveyer and a plurality of folding brakes along the sides of the frame and parallel with the path of movement of the sheets each brake including a relatively movable bed and nose piece adapted to clamp the sheet therebetween and a power-driven folding leaf pivoted adjacent the nose-piece for making the bend, retractable stops positioned in the conveyer at the downstream end of each brake and a pusher assembly with retractable clamping fingers for moving the blank transversely of the conveyer, a predetermined distance into the brake for the bending operation and retracting it back from the brake on to the conveyer for travel to the next brake, after the stops have retracted. The conveyer comprises rollers 26 mounted between side frames 18, 20 and has folding brakes 10a, 10b, 10c, positioned along its sides. A metal sheet placed on the conveyer is moved up to stops 60 and is then moved transversely into the brake 10a for a first flange to be formed. The sheet is then drawn back on to the conveyer, the stops 60 are retracted and the sheet moves on until it is halted by a second set of stops 60, in position to be moved into the brake 10b. At the station D the sheet is transferred to a second conveyer at right-angles to the first, which also has folding brakes along its sides, so that flanges can be formed on the sides at right-angles to those previously treated. Fig. 1A, shows the stages of forming the flanges. Folding brakes.-Each brake comprises a bed 15, Fig. 3, a nose piece 11, and a folding leaf 13 which is hinged to the bed. An hydraulic motor mounted in the leaf 13 drives a pinion 108 which meshes with a gear sector 112 and rotates the leaf through an angle determined by a screw stop 114. The bed 15 is lifted by a fluid cylinder 106 to clamp the work against the nose-piece. Alternatively the bed is fixed and the piston-rod 105 extends through the bed and actuates the nose-piece. In the case where a bend is to be made near the middle of a sheet, the formed sheet is withdrawn from the rear of the brake after folding, Figs. 24 and 25. The sheet is gripped between the bed 150 and nose-piece 175 and folded by the leaf 177. The upturned edge of the sheet is then engaged by a hook 181, the leaf 177 pivots downwardly, the nose-piece 175 rises and the work is drawn out of the brake by actuation of a cylinder 187 connected to the hook. Transverse pushers.-The workpieces are pushed from the conveyer into the brakes by clamps 80, Fig. 5. There are a pair of clamps at each station and each comprises an anvil 82 and an hydraulically operated clamping spindle 84. A gauging surface 88 abuts the edge of the sheet. Each clamp is mounted on a rack 90 which is slidably guided in a member 92 which extends between the sides 18 and 20. The rack is reciprocated by the rotation of a pinion 96 which is mounted on the same shaft as a further pinion which meshes with a second rack which is reciprocated by an hydraulic cylinder 104. The edge of the sheet is engaged by the surfaces 88 and is pushed a sufficient distance to ensure that the sheet is squared-up before the clamping spindles 84 are lowered. Conveyer positioning stops.-The stops 60 each comprise an arm projecting radially from a shaft on which is secured a pinion. All the pinions mesh with a rack (68), Fig. 8 (not shown), which is reciprocated by an hydraulic cylinder to rotate the stops to a position where they do not project between the conveyer rollers. Conveyer transfer mechanism.-At station D 2  there are narrow endless belt conveyers 109 positioned between the rollers 108, which are mounted so that their ends adjacent the conveyer 111 can be lowered. When the rollers are lowered the metal sheet rests on the belt conveyers 109 and is driven on to the rollers 110. In a modification, the conveyer 111 is a continuation of the first conveyer and at station D there is a turntable on to which the sheets are pushed and by which they are rotated through 90 degrees before continuing on to the second conveyer. When reverse bends are required in a sheet, the conveyer includes an inverter, which comprises a stop against which the sheets are moved and a curved arm pivotally mounted under the conveyer. When the sheet strikes the stop the arm is moved up through the rollers and turns the sheet over, Fig. 20 (not shown). Machine control.-The operation of the machine is governed by a camshaft (194), Fig. 26 (not shown), the cams on which operate electrical switches connected to solenoid-operated hydraulic valves, which in turn control the operation of the various hydraulic cylinders which actuate the machine.