Patent GB-612321-A (GB)
Title: Improvements in or relating to bending machines
IPC: B21D5/04
Filed: 1945-11-29
Abstract: 612,321. Angular bending. GREEN, L. B. Nov. 29, 1945, No. 32238. Convention date, Jan. 9. [Class 83 (iv)] Dies and formers.-In a pivoted bending machine a horizontally elongated anvil die operates to clamp the work against a co-operating stationary die and a movable die is then actuated to swing about said anvil die and bend the work around it. A machine particularly for use in bending pipes, bars and the like has side frames 16, 17, Fig. 10, provided with an integral bottom 18 and a spaced front wall 19, Fig. 5, having a horizontally extending ledge or table 20 at its upper end, forming a flat surface for mounting a fixed die member 13. A U-shaped carrier 25 pivoted to the side frames at 26 has a transverse frame portion 25a on which anvil die members 14 are secured, and pairs of co-operating guide elements on the side of the frame and the carrier limbs limit the swinging movement of the carrier. A double acting fluid pressure cylinder 30 operates the carrier and is connected to it through its piston 33, levers 34, 36 on a rock shaft 35 and links 37. An elongated hollow body 12 extends across the front of the machine with its supporting arms 44 pivoted on pins 46 arranged coaxial with the axis of the anvil and a plate 50 has yokes 51 with slots to engage pivot pins 53 arranged coaxial with the pins 46. The plate provides a mounting for the movable die member 15 and is supported at its forward end by spaced rolls 55, whilst a flange 60 bears against a lip 61 on the ledge 20 serving as a stop taking the thrust of the plate in its down position. Journalled in bearings 54a in the ends of the body 12 is a pressure roll 54 urged into contact with the plate by helical springs 56 and prevented from slipping movement with the plate by spaced pinions 58 on the roll which engage rack teeth 59 on the plate. A table 21 extends from the front of the machine, where it may be affixed to the ledge 20 to the back where it is secured to a cross member 21a and is provided with stops or gauges 22, 23, whilst additional work supports 24 may be arranged at any height above the table. In operation with suitable dies 13, 14, 15 fitted on the ledge, the carrier and plate 50 respectively, cylinder 30 is operated to move the carrier away.from the fixed bending die and the work inserted, and the cylinder operated to close the head and clamp the work. A second fluid pressure cylinder 63, connected to lugs 68 on the body 12 is then actuated to swing the body on its pivots moving plate 50 into the vertical position to bend the work around the anvil dies. Both cylinders are supplied with fluid from a tank 39 and pump 40 having a belt drive from an electric motor 41. Two levers fitted on the side frames control individually the valve gear of the pressure cylinders, and a push-button control is provided for the motor 41. Different sizes of pipes may be bent at the same time by fitting sets of co-operating die members 13a 14a, 13b 14b, 13c 14c, with complementary grooves, as shown in Fig. 10. In a modification for bending flat plates &c. die members 82, 86, 87, Fig. 11, having flat faces to co-operate in bending a sheet 81, are substituted for the pipe bend dies and the machine operated as before described. In yet another embodiment, and in order to obtain a true rocking motion between the anvil and moving die, the plate 50 is fitted with yokes 104, Fig. 14, having teeth 105 to engage gear sectors 106 on the frame constituting a fulcrum allowing the plate to swing with the body 12 about substantially the same axis. Conversion from the previous type of machine 'for use in bending tubes and operating with a wiping action, may be readily effected.