Patent GB-258922-A (GB)
Title: Improvements in or relating to machines for bending metals
IPC: B21D7/022
Filed: 1925-04-08
Abstract: 258,922. Oddie, F. A. April 8, 1925. Angular bending.-In a machine for bending pipes, rods, girders &c. of the type in which relative movement is effected between a curved former and a bending member so that the point of pressure moves along the work, which is restrained by an abutment at a point adjacent to the bend. the abutment is caused to yield to a controlled extent during bending so as to vary the curvature and so avoids the use of a separate bending member and former, means being provided for varying the extent of this movement. A curved former C is fixed by pins in sockets in a body block B<1>, which carries a pivot D for a turntable D<1> provided with handles D<4>. The turntable has a pin E which passes through a slot B<2> in the bed plate B. The intermediate part of the pin is eccentric and passes through a slot F<1> in a member F to which a detachable bending member F<4> may be secured by pins F<5> and pivoted catches G<3> on a slotted plate G. Rock teeth G<4> on the plate co-operate with teeth B<3> on the body block during bending so as to prevent rubbing of the member F<4> on the work. The member F <4> is pushed against the work H by rotating a handle E<2> on the end of the pin E. The bending may in another form be effected by a roller carried by the table D'. An abutment pin J movable in a curved slot B<4> is adjustably clamped in a slot K<1> in a link K, the pivot L of which is connected to a slide L<1> movable by a handle L<4> along a graduated guide M carried by the turntable and locked in position by a nut L<2>. When the slide is moved to one end of the scale the pivot L is concentric with the pivot D so that the abutment remains stationary when the table is rotated. In other positions the abutment moves along the guide B<4> to different extents during bending and so the curvature of the bend is varied. The adjustment of the abutment may alternatively be effected by connecting the pivot L to a screwed rod adjustable in a screwed socket on the table or to a rod slidable in and secured by a set screw to a socket on the table. In another form the adjustment may be effected by replacing the fixed guide B<4> by a guide the position of which may be varied. The adjustment may be effected automatically in cases where two or more operations of the bending member are required so as to effect different curves on different parts of the work. For this purpose the graduated guide M, Fig. 6, is provided with a rack M<1> engaging a worm N on the slide N<1>, the worm being connected through a universal joint N<2> with a square or splined shaft O axially movable in a sleeve P provided with bevel pinions P<1>, P<2>, and mounted in a bearing Q pivoted on a vertical axis in an extension D<5> of the table D'. A shaft R coaxial with the pivot of the bearing Q carries a bevel wheel R<1> engaging either of the bevel pinions and having below the part D<3> a pinion R<2> which is connected thereto by a ratchet mechanism and which engages a fixed rack S on the bed plate. During the inoperative movement of the table the pinion R<2> rotates the shaft R and thus traverses the slide N' to alter the position of the link K. The sleeve P is fixed in position by a set screw T engaging either of the grooves <p3> therein. In order that the extent of the movement of the slide N' at each oscillation of the table may be varied, an adjustable lost motion device may be used, such as two pins on the pinion R<2> adapted to engage opposite sides of a stop on the driven part, one of the pins being angularly adjustable. In a modification, Fig. 7, the former may be rotatable and bending effected by the abutment member J. The former B', and the plate provided with the slots B<2>, B<4> are rotated by a handle B<7> or power and the table D' is replaced by a member A<2> which is secured to the support A<1>, the pin E being screwed therein. Rotation of the former causes the rack B' carried thereby to move the member F<4> in the pin E and feed the work therethrough, the slot B<4> engaging the abutment member so as to cause it to move round to bend the work. The position of the slide L<1> determines the radius of the bend. According to the Provisional Specification the apparatus may be used for straightening bent rods &c.