Abstract: A machine for bending an elongated workpiece without wrinkling has a roller-like bending die (2) with a vice (3) adapted to retain one end of the elongated workpiece (P) to be bent. The roller-like bending die (2), being provided with a central hole (5) and a groove profile (6) and rotatable about a rotation axis (y), bears, centrally and coaxially in its groove profile (6), a plate element (18) oscillating with respect to the bending die (2) around a rotation axis (y) thereof. The plate element (18) having a peripheral edge (19) which continues the groove profile (6) of the bending die (2) consists of at least two pieces (20, 21) which are adapted to be connected to one another to surround the bending die (2).

Abstract: A mandrel for pipe bending machine has an elongated body (3) with a first end connected to a mandrel rod and a second end, opposite to the first, in which there is a spherical seat (8), several intermediate articulated elements (10) and a terminal articulated element (11). Each intermediate joint element (10) and the terminal joint element (11) have a peripheral part (12) configured so as to lean against the inner wall of a pipe (T) to be bent. Each intermediate articulated element (10) has a cup-shaped part (13) in one piece, and a stem (19) extending externally from it, and a spheroidal part (21) in one piece, configured so as to be introduced in a cup-shaped part (13) of a previous intermediate articulated element (10).

Abstract: A hydraulically operated rotary pipe bending machine has a box (1) from which superiorly protrude a die shaft (2) that is rigidly connected to a die and integral with a die gear (29) being driven by an actuator (30) through a hydraulic circuit and being stopped by a limit switch device (8), and a counter-die unit (3) driven by a handwheel (4) in order to place an elongated piece to be bent against said die. The actuator (30) has a single-acting cylinder, having a piston (31) holding a rack rod (30a) engaging said die gear (29), the piston (31) being opposed in its travel by a return spring (33). The limit switch device (8) has an angularly graduated disc (10) mounted, manually adjustable, on the die shaft (2) and provided with a cam (16) designed to control said limit switch (17) of the hydraulic circuit.

Abstract: A die and counter-die type bending machine for right- and left-hand bending an elongated piece (P) has a roller-shaped die (1) provided with a partial circumferential groove (2) that is interrupted at its two ends, the die (1) being driven by the shaft (0) of a motor, and a pair of counter-dies (25, 26) being carried by respective counter-die support members (19, 20) pivoted on a turret (11) that is rotatable mounted on a slide (8) in a given arc of rotation about its axis perpendicular to the slide (8) by a lever (12). The die (1) has an elongated piece retaining element (3, 4) at each of two ends of its partial circumferential groove (2). The first or the second counter-die is selectable to co-operate with the die in bending the elongated piece depending on the required curvature to right hand or left hand.

Abstract: A bending machine for helically bending an elongated workpiece (T) has at least three bending rollers (2) that, being rotatable integrally with respective supporting shafts (3) with parallel axes (y), co-operate in bending the elongated workpiece (T). Each bending roller (2) is arranged to shift along its own supporting shaft (3) by way of a prismatic coupling for a limited stroke and to swing with respect to the axis of the supporting shaft (3) by way of a partially spherical body (8) forming a rotary coupling with the supporting shaft (3) in a limited amount of angular displacement according to an arc of meridian of the partially spherical body (8), so that each bending roller (2) is orientated coplanar to the elongated workpiece (T) that takes an inclined position on the basis of a desired helix pitch.

Abstract: A die and counter-die type bending machine for right- and left-hand bending an elongated piece (P) has a roller-shaped die (1) provided with a partial circumferential groove (2) that is interrupted at its two ends, the die (1) being driven by the shaft (0) of a motor, and a pair of counter-dies (25, 26) being carried by respective counter-die support members (19, 20) pivoted on a turret (11) that is rotatable mounted on a slide (8) in a given arc of rotation about its axis perpendicular to the slide (8) by a lever (12). The die (1) has an elongated piece retaining element (3, 4) at each of two ends of its partial circumferential groove (2). The first or the second counter-die is selectable to co-operate with the die in bending the elongated piece depending on the required curvature to right hand or left hand.

Abstract: A method to check and control a roller bending machine for continuously bending an elongated workpiece at variable curvature radii in a bending machine using a series of rollers for bending, comprises the steps of measuring the distance of the elongated work piece in a point that is situated downstream the series of rollers for bending in successive instants, calculating a curvature radius of each bend section of the elongated workpiece, comparing the calculated curvature radius with the desired curvature radius and determining a difference between them, calculating the change of position to which an upstream roller has to be subjected in order to annul such a difference and operating the upstream roller on the base of the calculated change of position. A machine embodying the method is also described.

Abstract: A vise provided with a movable jaw device having separated approaching and clamping steps in a bending machine die, the vise (4) having a fixed jaw portion (7) and a movable jaw device (10) including a body (6) having two abreast supporting walls (8, 9), on an external side of one of which an operation mechanism (20) of the movable jaw is mounted, and upper edges (31, 32) of the supporting walls acts as cams for opposite spindles (29, 30) laterally projecting from one hydraulic cylinder (28) that is swing mounted on the movable jaw (11). The upper edges (31, 32) have two respective notches (33, 34) designed to receive the projecting spindles in such a way that the extension of the rod (27) of the hydraulic cylinder (28), being locked in position by its projecting spindles.

Abstract: A bending machine for helically bending an elongated workpiece (T) has at least three bending rollers (2) that, being rotatable integrally with respective supporting shafts (3) with parallel axes (y), co-operate in bending the elongated workpiece (T). Each bending roller (2) is arranged to shift along its own supporting shaft (3) by way of a prismatic coupling for a limited stroke and to swing with respect to the axis of the supporting shaft (3) by way of a partially spherical body (8) forming a rotary coupling with the supporting shaft (3) in a limited amount of angular displacement according to an arc of meridian of the partially spherical body (8), so that each bending roller (2) is orientated coplanar to the elongated workpiece (T) that takes an inclined position on the basis of a desired helix pitch.

Abstract: A method of measuring a length of sections of extrados or intrados curves of an elongated workpiece travelling in a bending machine along a forwarding direction, the elongated workpiece having cross-sections each of which is separated by a neutral axis in both an extended portion and a compressed portion when the elongated workpiece is subjected to bending, and at least a neutral cross-section, i.e. not subjected to bending, neutral cross-section beyond which the bending of the elongated workpiece begins along the forwarding direction thereof, provides a measuring instrument positioned so that it engages either an extrados or an intrados point of the elongated workpiece near the neutral cross-section, but displaced therefrom in the forwarding direction of the elongated workpiece. Further, a measuring instrument on a bending machine that embodies the method is described.

Abstract: A method to check and control a roller bending machine for continuously bending an elongated workpiece at variable curvature radii in a bending machine using a series of rollers for bending, comprises the steps of measuring the distance of the elongated work piece in a point that is situated downstream the series of rollers for bending in successive instants, calculating a curvature radius of each bend section of the elongated workpiece, comparing the calculated curvature radius with the desired curvature radius and determining a difference between them, calculating the change of position to which an upstream roller has to be subjected in order to annul such a difference and operating the upstream roller on the base of the calculated change of position. A machine embodying the method is also described.

Abstract: A vise provided with a movable jaw device having separated approaching and clamping steps in a bending machine die, the vise (4) having a fixed jaw portion (7) and a movable jaw device (10) including a body (6) having two abreast supporting walls (8, 9), on an external side of one of which an operation mechanism (20) of the movable jaw is mounted, and upper edges (31, 32) of the supporting walls acts as cams for opposite spindles (29, 30) laterally projecting from one hydraulic cylinder (28) that is swing mounted on the movable jaw (11).

Abstract: A method of measuring a length of sections of extrados or intrados curves of an elongated workpiece travelling in a bending machine along a forwarding direction, the elongated workpiece having cross-sections each of which is separated by a neutral axis in both an extended portion and a compressed portion when the elongated workpiece is subjected to bending, and at least a neutral cross-section, i.e. not subjected to bending, neutral cross-section beyond which the bending of the elongated workpiece begins along the forwarding direction thereof, provides a measuring instrument positioned so that it engages either an extrados or an intrados point of the elongated workpiece near the neutral cross-section, but displaced therefrom in the forwarding direction of the elongated workpiece. Further, a measuring instrument on a bending machine that embodies the method is described.

Abstract: A machine for continuously bending an elongated workpiece at predetermined radii, machine that uses a series of driving rollers (1, 2, 3) for bending, includes a 2D laser displacement sensor (5) downstream the series of driving rollers (1, 2, 3) for bending and a computer (7) that is coupled among other to the 2D laser displacement sensor (5) for calculating a radius of a bend section and comparing the calculated radius of curvature with the desired radius of curvature. The computer (7) is coupled to a length meter (4) for measuring a length of the bend section concentrically to the elongated workpiece (T) and, further, to operating elements (8) adapted to operate a roller (2) of the series of driving rollers (1, 2, 3) for bending in order to adjust it on the base of a difference between the measured radius of curvature and the desired radius of curvature.

Abstract: A pipe bending machine with bending mandrel having a load bearing structure which is particularly resistant to working stresses, comprises an extractor (2) which is fixed in a rear portion of the pipe bending machine, and mandrel rod (13) which extends with its longitudinal axis (g), from the extractor beyond a front portion of the machine, where a bending head (7) which is provided with a die (8) stresses a pipe (T) to be bent, which is inserted in a mandrel (12), by a traction resultant force that is transmitted along the mandrel rod (13) to the extractor (2) that counteracts with a resultant restraining reaction. The pipe bending machine comprises a load bearing structure (1) having a profile such that it contains inside the longitudinal axis (g) of the mandrel rod (13), in such a way that the load bearing structure (1) is subjected mainly to compression stresses.

Abstract: A pipe bending machine having an improved movement transmission to a bending die comprises a body (1) and a head (2). Housed in the body (1) is a motor (3) having an output shaft (4) supporting a driving gear wheel (5), which is located in the machine head (2). Located in the same machine head (2) is a driven gear wheel (8), which is connected to a pipe bending die (6). A couple of intermediate gear wheels (9, 10) engage both the driving gear wheel (5) and the driven gear wheel (8).

Abstract: A pipe-bending machine mandrel includes a rigid member (5), inserted inside a pipe (T) which has an internal dimension Di and can tilt in a bending operation with a mean radius Rm as measured between the rotation center (O) of a bending die and the longitudinal axis (l) of the pipe (T). The rigid member (5) has a proximal side profile with respect to the rotation center (O) and includes a concave intermediate portion as generated by a radius Rci, and a distal side profile with respect to the rotation center (O) that includes two convex, divided, end portions as generated by respective radius Rce, where Rci=Rm?(Di/2)+t, and Rce=Rm+(Di/2)?t, t being a term varying according to the accuracy of the dimensional characteristics of the pipe and of the curve to be obtained.

Abstract: A bending machine with a controlled-return bending die includes a matrix (2) mounted around a spindle (3) having an axis y, a bend arm (4) being able to turn around on the same axis y, and a vice (5) adapted to clamp a section of a workpiece to be bent. A driving element causes the bend arm (4) and the matrix (2), both being connected together by the vice (5), to rotate around the axis y for a set angle from a start position, and a workpiece bending operation is performed for a workpiece section corresponding to the angle. The bend arm (4) carries on itself a controlled return element able to return the matrix (2) to its start position at the end of workpiece bending operation.

Abstract: A pipe-bending machine mandrel includes a rigid member (5), inserted inside a pipe (T) which has an internal dimension Di and can tilt in a bending operation with a mean radius Rm as measured between the rotation center (O) of a bending die and the longitudinal axis (l) of the pipe (T). The rigid member (5) has a proximal side profile with respect to the rotation center (O) and includes a concave intermediate portion as generated by a radius Rci, and a distal side profile with respect to the rotation center (O) that includes two convex, divided, end portions as generated by respective radius Rce, where Rci=Rm?(Di/2)+t, and Rce=Rm+(Di/2)?t, t being a term varying according to the accuracy of the dimensional characteristics of the pipe and of the curve to be obtained.

Abstract: A hydraulic circuit for linearly driving a movable roller-holder slider of a pipe bending machine, comprising a hydraulic cylinder (5) whose piston rod is connected to a slider holding a movable roller, the cylinder being fed with pressurized fluid from a reservoir (16) by a pump (15), through a three-position four-way valve (18), a check valve (12, 13) and an interposed throttling valve (19), that is operated to generate an increased pressure in said low pressure chamber of the hydraulic cylinder (5) in order to slow down the slider holding the upper roller in its primary motion when a programmable interval is reached from said predetermined position for each working pass.