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 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 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 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.

Abstract: A bending device for bending machine comprises a matrix (2), a countermatrix (6), and a die (7) able to prevent wrinkles. A countermatrix-holder support element (8) is fixed on an upper slide (10), which is slidable transversally to a workpiece T to be bent on a lower slide (11) movable in turn in the same direction of the upper slide (10), on a table (12). A first double-acting cylinder (19), being fixed on said lower slide (11), moves the countermatrix (6) toward and away from the workpiece (T); and a second double-acting cylinder (24) is slidable on the upper slide (10) and connected to a slider (25) on a counteracting rod (26) which is pivoted about an end of an arm-turning spindle (3), so that a force is exerted on the countermatrix-holder support element (8) in a projecting portion (23) thereof.

Abstract: A bending machine with a compact bend arm includes in a bend arm (4) being mounted on a rotating spindle (3) a cylinder which is fed with a pressured fluid through hoses (7) being part of a hydraulic circuit connected to a source of pressured fluid and of an electric circuit. Each of the hoses (7), which are side by side, comprises a curved section (7a) around the rotating spindle (3), the curved section (7a) being radiused at one end to a section (7b) parallel to the bend arm (4), and at the other end to a section (7c) directed to the rest of the bending machine, to which hoses (7) are retained. In the section (7b) parallel to the bend arm (4) the plurality of hoses (7) are clamped on a slider (9) slidable in a prismatic guide (10) which is provided in the bend arm (4).

Abstract: A curling machine provided with an adjusting device for evenly winding elongated workpieces into spirals, includes a machine frame sustaining a horizontal worktable; a vertical axis mandrel for a curling tool and provided with a counteracting device for acting on elongated workpieces passing through the worktable. The counteracting device is connected to an actuator in the form of an oleodynamic cylinder which is fixed on the worktable and provided with a rod carrying a tool holder in the free end of the rod, the vertical axis mandrel being removable from the worktable.

Abstract: A vise for clamping an elongated workpiece to be bent on a die (2) of a bending machine includes a movable jaw (35), provided with a clamping portion (51) approachable to and removable from the circumferential groove (4) of the die (2). The movable jaw (35) has a pivoting end (7) and a retaining end (8) opposite to the pivoting end (7). The pivoting end (7) is rigidly connected to a spindle (9) rotatable about an axis (X) at right-angles to the rotation axis (Y) of the die (2), so that the clamping portion (51) of the movable jaw (35) is displaced by an operating device (90) from an opened position, far from the elongated workpiece to be bent, to a closed position in which the clamping portion (51) mates with the elongated workpiece. A retaining device (28) is able to grip the retaining end (8) of the movable jaw (35) and to maintain the movable jaw (35) in its closed position.

Abstract: A control element (1) adapted to prevent an external-flange angle iron from being twisted during its bending is applied to a variable-radius bending machine, on which an angle iron (10) is worked by deformation by at least two couples of lower co-axial rollers (7, 8, 7?, 8?) and at least a third upper roller (9), the one flange (11) of the angle iron (10) being clamped by the lower rollers (7, 8, 7?, 8?), and the other flange (12) facing outward. The control element (1) includes a frustoconical head (2) pivoted on a stem (3) designed to be received into a co-axial housing hole that is frontally performed on the support element (13) of a cylindrical control roller (14), having three degrees of freedom, of the bending machine.

Abstract: A shaping pulley assembly (6) for a belt notching machine, including on a frame (1) a pair of driving and shaping pulleys (3, 4) for a grinding belt (5), includes a shaping pulley holder element (9) like a fork supported by the frame (1), having a C-shaped body with end brackets (90, 91), a stationary center and a removable counter-center, both being live centers which are housed in respective housings of the end brackets (90, 91), a shaping pulley (4) in the form of a cylindrical roller provided with center holes (42, 43) opposite to each other for fixed centre and removable counter-center, respectively on the bases (40, 41) of the shaping pulley.

Abstract: A hydraulic circuit for linearly driving a machine-tool slider in both directions, comprising an hydraulic cylinder (5) whose piston rod (4) is connected to a slider and which is fed with pressurized fluid from a reservoir (14) by a pump (15) through a three-position four-way valve (18), a check valve (12-13), and between the last ones, a pair of throttling valves (19, 19?) which are mounted symmetrically each other and operated to generate an increased pressure in either one or the other chamber, which is at the moment in a low pressure, of the hydraulic cylinder (5) in order to slow down said slider in its work motion in both directions of linear travelling when a programmable interval is approached from a predetermined position for each working pass. Situated in the bypass (190, 190?) of each throttling valve (19, 19?), among the same valves (19, 19?) and the hydraulic cylinder (5), is a manual flow control valve (20, 20?).

Abstract: A shaping pulley assembly (6) for a belt notching machine, including on a frame (1) a pair of driving and shaping pulleys (3, 4) for a grinding belt (5), includes a shaping pulley holder element (9) like a fork supported by the frame (1), having a C-shaped body with end brackets (90, 91), a stationary center and a removable counter-center, both being live centers which are housed in respective housings of the end brackets (90, 91), a shaping pulley (4) in the form of a cylindrical roller provided with center holes (42, 43) opposite to each other for fixed center and removable counter-center, respectively on the bases (40, 41) of the shaping pulley.