GB924683A - Pipe bending machine - Google Patents

Abstract

924,683. Tube benders. H. G. BRAGD. Oct. 1, 1959 [Oct. 2, 1958], No. 33310/59. Class 83 (4). A tube-bending machine includes a rotatable bending head carrying jaws which clamp the tube and a former around which the tube is bent arranged so that the bending process begins where the tube intersects the axis of rotation of the bending head, and a mandrel, from which the tube is withdrawn during bending, the mandrel being swingably mounted. A tube to be bent is pushed on to a mandrel 12A until it contacts a relevant end stop 44 carried by a mandrel support 12 swingably mounted on an extension 13 of the machine base. A pedal 40 is then depressed to clutch a driving motor to a shaft 15 of a bending head 11. The shaft 15 is formed at its upper end with a disc 14 to which are secured a cam ring 17 and a central cam 20. A ring 21 rotatable on the disc 14 carries a rail 22 on which are slidably mounted jaws 23, 24, the jaw 23 having depending therefrom a roller 29 engaging the cam ring 17 and a roller 31 engaging the cam 20 and the jaw 24 having similar rollers 30, 32. As the disc 14 and thus the cam ring 17 rotate the rollers 29, 30 are moved inwardly to clamp the jaws 23, 24 on to the tube to be bent. Stops 18<SP>1</SP>A, 19A on the cam ring 17 then engage the rollers 29, 30 so that the jaws 23, 24 are rotated with the disc 14 to commence the bending, the tube being withdrawn from the mandrel 12A and bent around a grooved section 45 of an off-centre forming disc 25 or 26 adjacent the jaw 23 or 24, the mandrel 12A swinging about the pivot of its holder 12 as bending proceeds and the actual point where the bending takes place moves away from the axis of rotation of the bending head 11. The swinging of the mandrel 12A is limited by abutments 46, 47 on the jaws co-operating with abutments 48, 49 on the mandrel holder 12. An abutment (not shown) on the bending head 11, hits pins 42 mounted in pneumatic cylinders on a ring 43 to turn the ring 43 slightly to disconnect the drive from the motor to the shaft 15 and thus stop the bending. The direction of rotation of the motor is simultaneously reversed. When the pedal 40 is released, the shaft 15 is again connected to the motor, the jaws 23, 24 are turned to their original position and the engagement of the cam 20 with the rollers 31, 32 moving the jaws apart to release the tube. The setting of the particular pin 42 to determine the angle of bend and the direction of rotation of the motor are determined by cams in a control device operating switches and compressed-air valves. The jaws 23, 24 are centered at the beginning of the bending relative to the mandrel holder 12 by rollers (not shown) on the jaws co-operating with cam surfaces on the mandrel holder 12.