Patent GB-927262-A (GB)
Title: Tube bending apparatus
IPC: B21D7/06
Filed: 1961-11-21
Abstract: 927,262. Angular bending. K. BOS. Nov. 21, 1961 [Nov. 28, 1960], No. 41561/61. Class 83 (4). Apparatus for bending rods, tubes or sections, includes bend parts comprising a bend former and at least one coacting part to engage a workpiece for bending transverse to an alignment axis, actuating means for displacing at least one of the bend parts to bend the workpiece, means for locating a workpiece coaxially with a relative to the alignment axis by locating one end of the workpiece both in axial distance from the bend former and in its rotational disposition about the alignment axis, the locating means comprising a shaft disposed parallel to the alignment axis, axially spaced transversely disposed arms fast with and circumferentially spaced about the axis of the shaft, the axial spacing between the various arms corresponding to various pitches between bends to be formed in a workpiece, and engaging means on each transverse arm adjustable in position in the arm about an axis parallel to the shaft axis for locating the rotational position of a workpiece about the alignment axis to determine the angle between the planes of the bends to be formed in the workpiece. The notched rear end of a tube 26 to be bent is engaged by a plug 34, rotatably adjustable on a transverse arm 36 adjustable about a shaft 38. A bend former 14 then descends to grip the tube 26 against wing dies 16, a switch 53, closed by the movement of the former 14, energizes a solenoid to operate a valve to cause compressed air means 92, Fig. 8, in a tail base 52 to move the shaft 38 longitudinally and withdraw the plug 34 from the tube end. Continued descent of the former 14 bends the tube, the wing dies 16 pivoting about the axes of their shafts 70 against the bias of a weight 18 acting through cables 20 and bars 310 fast with the dies 16. As the dies 16 pivot a cam 72 fast on the shaft 70 of one of the dies rotates to wrap a tape 76 around itself and thus pull up a shoe 78 carrying a microswitch 63. When the switch 63 contacts the appropriate one of a number of stops 62, carried at different heights around a spider 64, the former 14 is stopped and reversed, the position of the stop 62 thus determining the degree of bend. The switch 63 also starts a motor 138 to rotate the shaft 38 to position the next arm 36 and at the same time the spider 64 is rotated via chain drive 150, shaft 68 and flexible cable 66 to bring a new stop 62 into operative position. An index plate 118 fast on the shaft 38, unlatched when the shaft 38 was moved back by the compressed air means 92, is stopped in the correct position by a catch 122 which causes a switch 134 to stop the motor 138. The tube 26 is then moved longitudinally and its rear end engaged by the plug 34 now in position and another bend is made. In another embodiment, Fig. 13, a bar, or a tube 26 with a mandrel 252 therein, is gripped in a chuck 210 on a carriage 204, movable along a guide rail 202, which is then positioned so that a mating means 222 on an arm 220 of the carriage 204 is in engagement with the engaging means 34 to locate the carriage axially. A drive chain 214 links the chuck 210 and mating means 222 for adjustment of the bar and tube 26 about the axis. As the tube 26 is bent about a rotated former 14a the carriage 204 moves towards the former.