GB1344387A - Apparatus and method for bending elongated objects - Google Patents

Abstract

1344387 Angular bending COJAFEX NV 19 April 1971 [12 March 1970 8 Jan 1971] 23901/71 Heading B3E [Also in Divisions B6 and C1] An elongated beam, rod or tube 1, of metal, glass or a synthetic thermoplastic polymer, guided by means 4, 5, 7, is forced through a narrow transverse heating zone 14 and then bent by a pivoted arm 10 whose pivot 11 lies substantially in the transverse plane of the heating zone and whose relative transverse distance therefrom is variable during bending. A tube to be bent is mounted in the frame 2 and is guided, when forced by spring, hydraulic cylinder or screw-threaded means in the direction of arrow 3, by rollers 4 and 5 and a roller guide 6. The forward end of the tube is adjustably clamped to the bending arm 10 which is pivoted at 11 to a link 12 which permits movement of the pivot 11 during bending. Slots 15, 16 provide adjustment for different tube diameters and radii of bending. Alternatively the pivot 11 may be fixed and the guide frame 2 permitted to slide or pivot transversely during bending, Figs. 3-6 (not shown). Resilient means such as springs or rubber blocks may be provided to resist variation of the transverse distance, or the pivot 11 may be carried by blade springs (17, Fig. 2, not shown). Water is sprayed on the tube after passing through the heating device during the bending. Any deviation in the transverse distance, caused, e.g. by irregular tube wall thickness, may be monitored by a sensing device and used to adjust slightly the position of the heating device or of the pivot 11 longitudinally of the tube. The machine can be arranged for bending tubes, rods or bars into a helical shape by displacing during bending the centre of rotation 13 of the rockable arm 12. In another embodiment, Fig. 7, the bending arm 102 is pivoted to one end of a base bar frame 125 the other end of which is adjustably pivoted to the tube guide frame 104. At the end of the guide tube adjacent the heater 133 is attached a link mechanism 121, 128 and 129 the latter two links being pivoted to the bar frame 125. The length of the link 129 is adjustable by a turnbuckle 132 for varying the position of the pivots 101 relative to the heating zone 134. To increase the compressive force in the heated zone to counteract wall thinning, a braking force is applied to the arm by electrical or hydraulic means.