Patent GB-1037223-A (GB)
Title: Improvements in or relating to the bending of metallic bars
IPC: B21D7/08
Filed: 1962-08-29
Abstract: 1,037,223. Bending; rolling. HUGH SMITH (GLASGOW) Ltd., and D. C. JEFFREY. Aug. 23, 1963 [Aug. 28, 1962], No. 32921/62. Headings B3E and B3M. A method of bending a metallic bar comprises generating in each part of the edge portion of the bar which will have the greatest radius of curvature when the bar is bent, a compressive stress, the direction of which is parallel with the axis about which the bar is to be bent and the magnitude of which is such as to cause plastic deformation in, and thus an increase in the longitudinal dimension of the part. In an embodiment an "I," "T" or angled sectioned member in which the flange(s) are to be on the outside of the curve is located on a fixed driven roller 3, mounted in a frame 1, against an abutment roller 6 and a movable driven roller 2 lowered to compress and plastically deform the member into the desired curvature as it passes between the rollers. The rollers 2, 3 may be double bevelled. The rollers are driven through gearing by separate electric motors. One of the rollers may be an idler and they may be movable towards one another by fluid pressure. Guide rolls are mounted on the frame 1 at the entrance and exit sides of the deforming rollers. 1,037,243. Shearing; forging. DAVY & UNITED ENGINEERING CO. Ltd. Jan. 28, 1965 [Feb. 19, 1964], No. 6961/64. Headings B3H and B3W. In an hydraulic down and up-cut shear the top tool 20 is carried by an upper cross-head 18 supported by a plurality of columns 22 arranged to move in a base 12 and connected at their lower ends by a beam 23. The lower tool 25 is mounted on a lower cross-head 24 which is guided by the columns 22 and is raised by three rams 27, 28 sliding in cylinders 13, 14. Fig. 2 is a vertical half-section through the shear. A feeler 31, Fig. 1 (not shown), is supported on a rod 32 mounted for vertical movement in the upper cross-head, the rod being pivotally connected to one end of a lever 33 mounted in trunnions 36 on the upper cross-head. The other end of the lever is connected to the piston-rod of a fluid cylinder assembly which is supplied with fluid at a constant pressure from an accumulator. The feeler is normally urged to a position in which its lower surface is just below the lower surface of the top tool 20. The beam 23 is urged downwards by three rams 37, 38 which also slide in the cylinders 13, 14, and is also connected to double-acting control rams 40 reciprocable in cylinders 15. Operation.-Oil from a main pressure pump is admitted to the upper end of the cylinders 15 causing the top knife to descend, the main cylinders 13, 14 drawing fluid through prefilling valves. When the feeler reaches the workpiece the control rams encounter additional resistance equal to the feeler-load and the ensuing pressure rise in the control cylinders 15 causes the closing of the exhaust valve from the lower side of the cylinders 15, and the inlet valves to the upper end of the cylinders 15. Oil from the main pressure pump is then admitted to the cylinders 13, 14 and raises the lower tool 25 to cut the work. The cut-off piece is held between the lower tool 25 and the feeler 31. The upward movement of the lower tool 25 operates a limit switch which cuts off the fluid supply to the cylinders 13, 14 and opens the exhaust valves. The beam 23 is then pushed down by the feeler 31, until it operates a second limit switch which closes a main exhaust valve, but leaves open a smaller valve so that the cutoff piece is lowered slowly on to a roller table. A third limit switch stops the beam 23 at the bottom of its travel, and initiates upward movement of the upper cross-head 18 to a position determined by a fourth limit switch.