Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D11/00—Bending not restricted to forms of material mentioned in only one of groups B21D5/00, B21D7/00, B21D9/00; Bending not provided for in groups B21D5/00 - B21D9/00; Twisting
  • B21D11/10—Bending specially adapted to produce specific articles, e.g. leaf springs
  • B21D11/12—Bending specially adapted to produce specific articles, e.g. leaf springs the articles being reinforcements for concrete
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21F—WORKING OR PROCESSING OF METAL WIRE
  • B21F23/00—Feeding wire in wire-working machines or apparatus

Definitions

• the present invention concerns a bending machine for metal bars, particularly for metal bars fed from a roll or coil, and sheared on each occasion according to the shape and size, that is, the linear development, of the shaped article to be made.
• the bending machine according to the invention includes at least an auxiliary drawing assembly able to move, possibly forward and backward, the terminal segments or tail ends of the roll, so as to be able to make the bends on said terminal segments with greater ease and accuracy, and/or to discharge segments or working scrap from the machine.
• EP-Al-1.535.675 describes the features of the preamble of the main claims 1 and 10. BACKGROUND OF THE INVENTION
• Bending machines for bars are known, suitable to produce shaped reinforcement elements, such as for example stirrups, which machines essentially consist of at least a bending assembly, a shears and a drawing assembly, disposed upstream of the shears in order to pick up the bars to be bent from a store and feed them to the bending machine.
• Known bending machines can have a second drawing assembly disposed downstream of the bending assembly, which is used to move the bar linearly with respect to the bending assembly, so as to perform tail-end bends in order to make the shaped piece.
• the drawing assemblies can be of the type with rollers, grippers or a combination of rollers and grippers.
• the auxiliary drawing assembly remains substantially always gripping on the pre-cut bar being worked, mainly so as to allow, when the article is complete, to discharge the working scraps or surpluses from the machine, and so as to assist the drawing assembly downstream of the bending machine in feeding the terminal segment of the bars when the so-called tail-end bends are being made.
• Purpose of the present invention is therefore to achieve a bending machine for bars fed from a roll and provided with an auxiliary drawing assembly disposed immediately upstream of the shears, which does not have the functional disadvantages of the state of the art.
• the Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.
• the bending machine according to the present invention is applied for shaping metal bars fed from a roll and comprises at least an assembly to bend the bars, at least a shearing assembly disposed upstream of the bending assembly and able to shear to size the bars fed from the roll, a first drawing assembly disposed upstream of the shearing assembly and able to unroll the bars from the roll in order to feed them to the bending assembly, and at least a second auxiliary drawing assembly disposed upstream of the shearing assembly and downstream of the first drawing assembly, and able to feed the terminal part of the roll, for example when it is nearly finished, and possibly discharge the working scrap in order to finish the completed article.
• the second drawing assembly comprises, associated therewith, selective clamping/unclamping means, able to intervene suitably on the gripper members of the drawing assembly, in order to determine at least a first substantially uninfluential operating condition, in which the gripper members do not interfere with the advance of the metal bars fed by the first drawing assembly, so as to allow them to advance freely through the second drawing assembly, and a second active operating condition, in which the gripper members interfere with the advance of the metal bars and determine the feed thereof towards the bending assembly.
• the second active operating condition is assumed in particular when the roll that feeds the bars is nearing the end, that is, when the segment of bar that is formed after shearing is no longer gripped by the first drawing assembly, and the residual segment has to be discharged from the machine.
• This condition can also be assumed when it is desired to make small shaped pieces, for example when the last side is shorter than the distance between the first drawing assembly and the bending assembly.
• the gripper members of the second drawing assembly remain in the first uninfluential operating condition, so as to prevent accidental, non-synchronized feed of the two drawing assemblies, causing the formation of loops with consequent blockages.
• the selective clamping/unclamping means take the gripper members of the second drawing assembly to their second active operating condition, causing the last segment of the roll to be fed to the bending assembly.
• the selective clamping/unclamping means comprises one or more actuators able to keep the gripper members, for example two or more rollers, selectively distanced and separated from the metal bars in transit, according to the operating condition provided.
• the selective clamping/unclamping means comprises a clutch member which selectively makes the rollers idle, so as to define the first uninfluential operating condition.
• - figs 1 and 2 show schematically a view from above of a bending machine according to the invention in two different operating steps;
• - fig. 3 shows an enlarged detail of the machine according to the invention in the operating position in fig. 1 ;
• - fig. 4 shows a section from A to A in fig. 3 in the operating condition in fig. 1 ;
• - fig. 5 shows a section from A to A in fig. 3 in the operating condition in fig. 2;
• - fig. 7 shows a lateral view of the detail in fig. 6 in the operating condition of fig. 1;
• - fig. 8 shows a lateral view of the detail in fig. 6 in the operating condition of fig. 2.
• a bending machine 10 according to the present invention is applied to make shaped reinforcement articles for the building sector, starting from metal bars 1 1 fed directly from a roll 12 or coil.
• metal bars 1 1 fed directly from a roll 12 or coil.
• two metal bars 11 arriving from two different rolls 12 are fed simultaneously to the bending machine 10, but it cannot be excluded that the bending machine 10 can also be fed by a single metal bar 1 1 or by three or more metal bars 11 simultaneously.
• the bending machine 10 essentially comprises a bending assembly 13, a shears 14 located upstream of the bending assembly 13, a first drawing assembly 15 with pairs of rollers 19, located upstream of the shears 14, and a second drawing assembly, or auxiliary drawing assembly 16, disposed immediately upstream of the shears 14 and downstream of the first drawing assembly 15.
• the bending machine 10 also comprises a third drawing assembly
• tail-end bending of their terminal segment.
• the second drawing assembly 16 comprises a plurality of rollers 20, of which at least one is driven, indicated in its entirety by the reference number 21, and at least a gripper roller 22, opposite the driven roller 21 with respect to the metal bars 11, and selectively cooperating with the driven roller 21 to draw the metal bars 11.
• the driven roller 21 is keyed to a shaft of an oil-dynamic motor 24.
• the gripper roller 22 is mobile with respect to the driven roller 21, and is associated with a clamping/unclamping device 23 which, as will be explained hereafter in detail, allows to selectively configure the gripper roller 22 between a first operating condition, in which it has substantially no effect on the drawing of the metal bars 11 and allows the free advance thereof through the second drawing assembly 16; and a second operating condition, in which it actively participates in the drawing of the metal bars 11, and allows to feed to the bending assembly 13 the terminal parts, or tail ends, of the roll 12 from which the metal bars 1 1 are obtained, when the latter are no longer gripped in the first drawing assembly 15, or allows said terminal parts to be discharged from the machine.
• a first operating condition in which it has substantially no effect on the drawing of the metal bars 11 and allows the free advance thereof through the second drawing assembly 16
• a second operating condition in which it actively participates in the drawing of the metal bars 11, and allows to feed to the bending assembly 13 the terminal parts, or tail ends, of the roll 12 from which the metal bars 1 1 are obtained, when the latter
• Each gripper roller 22 is normally cushioned by means of a helical spring 25, associated in known manner with the rotation shaft 29 of the gripper roller 22, so as to render the latter elastically pivoting and to absorb possible imperfections and vibrations of the metal bars 11. Due to the effect of the pressure exerted by the helical spring 25, facing downwards in the attached drawings, the relative gripper roller 22 normally remains in contact with the driven roller 21 , at a determinate inactive pressure, and in any case not interfering with the drawing, which determinate pressure is easily contrasted by the metal bars 11 in transit.
• the gripper roller 22 is not able to keep the metal bars 11 adherent to the driven roller 21 and hence the second drawing assembly 16 does not perform any action on the metal bars 11, which on the contrary advance substantially freely through it, and functions only as a guide.
• the clamping/unclamping device 23 consists substantially of an oil-dynamic actuator 26 disposed above and coaxial with the helical spring 25, so that, by means of a metal block 27 associated therewith, it determines the selective axial compression of the helical spring 25.
• This compression determines an increase in the contact pressure between the gripper roller 22 and the driven roller 21, so that the metal bars 1 1 in transit between them are gripped substantially between the two rollers 21 and 22, and therefore are actively subjected to the drawing action imparted by the second drawing assembly 16.
• the bending machine functions as follows.
• the oil-dynamic actuator exerts said axial pressure on the helical spring 25 by means of the metal block 27, in such a manner that the metal bars 11 in transit in the second drawing assembly are substantially gripped between the two rollers 21 and 22 (fig. 5).
• the second drawing assembly 16 comprises, apart from the rollers 20, at least a driven roller, indicated in its entirety by the reference number 121, and at least a contrasting roller 122, opposite the driven roller 121 with respect to the metal bars 11, and selectively cooperating with the driven roller 121 to draw the metal bars 11.
• the driven roller 121 is keyed to a shaft of an oil-dynamic motor 124 which is mounted in turn on a metal slider 127.
• the driven roller 121 is movable with respect to the contrasting roller 122, and is associated with a clamping/unclamping device 123 which, as will be explained in detail hereafter, allows the selective configuration of the driven roller 121 between a first operating condition, in which it does not interfere with the metal bars 11 and allows the free advance thereof through the second drawing assembly 16, and a second operating condition, in which it acts on the metal bars 11 and actively participates in their drawing.
• the driven roller 121 allows to feed to the bending assembly 13 also the terminal parts or tail ends of the roll 12 from which the metal bars 11 are obtained, when the latter are no longer gripped in the first drawing assembly 15, or allows them to be discharged from the machine.
• Each contrasting roller 122 is associated axially with an encoder 125, or other type of position transducer, which allows the metric counting of the metal bars 1 1 fed, and sends relative signals to a command and control unit of the machine 10, in order to optimize the management of the switching on/off of the motors provided.
• the clamping/unclamping device 123 comprises an oil-dynamic actuator 126 disposed above and connected to the metal slider 127, so as to determine the selective vertical movement thereof.
• the vertical movement of the metal slider 127 determines the movement of the oil-dynamic motor 124, and consequently of the driven roller 121, with respect to the contrasting roller 122, until contact with the metal bars 1 1.
• the metal bars 1 1 in transit are gripped between the two rollers 121 and 122, and therefore are subject to the drawing action imparted by the second drawing assembly 16.
• the drawing action can be imparted either to feed short segments of bar 1 1 to the bending assembly, in order to make small pieces, or to discharge from the machine 10.
• the clamping/unclamping device 23 can comprise a clutch able to selectively release the rotation of the driven roller 21 with respect to the relative oil-dynamic motor 24, and hence define the two conditions, respectively, the uninfluential condition, by making the driven roller 21 idle, and the active drawing condition, by making the driven roller 21 draw.
• the clamping/unclamping device includes movement members, associated respectively with the rollers 21 and 22, in order to reciprocally distance the latter from each other and from the axis of feed of the metal bars 1 1.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Bending Of Plates, Rods, And Pipes (AREA)
• Folding Of Thin Sheet-Like Materials, Special Discharging Devices, And Others (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Family Cites Families (6)

• 2006
  • 2006-06-08 IT ITUD20060147 patent/ITUD20060147A1/it unknown
• 2007
  • 2007-06-05 WO PCT/EP2007/055526 patent/WO2007141273A1/en active Application Filing
  • 2007-06-05 EP EP07729905A patent/EP2029297A1/en not_active Withdrawn
  • 2007-06-05 RU RU2008151432/02A patent/RU2433879C2/ru not_active IP Right Cessation
  • 2007-06-05 BR BRPI0711489-3A patent/BRPI0711489A2/pt not_active IP Right Cessation

Non-Patent Citations (1)

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