EP0892686B1 - Machine for bending or cambering a profile section, and bending head therefor - Google Patents

Description

The invention relates to a bending or bending a profile such as rod, tube, bar, wire or similar according to the preamble of claim 1. It also targets a bending head intended to equip such a machine, according to the preamble of claim 15.

Current bending machines conventionally include a frame on which are mounted bending means comprising a clamping jaw and a bending shape with support surfaces between which pass, is tightened then rolled up the profile to bending, said bending means being mounted on a folding head able to pivot about a coaxial axis with the axis of the bending shape. In addition, these machines bend usually include a guide strip arranged upstream of the clamping jaw and a flattening element arranged upstream of the bending form. Finally, they include means for longitudinal displacement of the profiled relative to the frame.

The major disadvantage of these machines has bending lies in the fact that they do not allow to bend the profiles only on one side, either to the right or to the left. Moreover, the clamping jaw positioning assembly and the set of displacements of the slide generate a space limiting the geometry of the final parts curved.

In order to overcome the drawback relating to one way bending, three main types of machines to bend exist at present.

First, a first solution consists in providing the bending machines with a clamp digitally controlled suitable for rotating the profiled around its axis in order to change the direction of bending. However, such bending machines have a first drawback resulting from the fact that, when changing the centering direction, the movements of the profiled generate so-called "whiplash" phenomena likely to alter the shape of the part carried out.

A second solution consists in carrying out bending machines with drive means in rotation of the folding head capable of rotating this last around the profile.

A third solution finally consists in bending machines with double heads folding associated with rotational drive means allowing this folding head to rotate on itself. However, this solution leads to the realization of relatively complex and therefore expensive bending machines important cost.

In addition, in general, and whatever either the technique adapted from the above solutions described, all current bending machines have two major drawbacks in addition to those above mentioned. Indeed, and first of all, because of their design, they all generate such a bulk limit the geometry of the curved end pieces. In the practice, for example, of such bending machines make it difficult to produce complex parts having in particular 180 ° consecutive bends forming S. In addition, the cycle times of these machines to bend are relatively large, leading to a low production rate.

Two other types of machines, described respectively in patents FR 2,150,503 and EP 561,025, have been developed to allow bending in both ways.

• un porte-mandrins cylindrique associé à une roue dentée portant deux arbres horizontaux équidistants de l'axe dudit porte-mandrins, chacun de ces arbres portant un galet et reposant dans des berceaux solidaires du bâti,
• un système chaínes/pignons actionné par des vérins, agencé pour coopérer avec la roue dentée de façon à faire pivoter le porte-mandrins autour de l'axe de l'un ou l'autre des arbres logés dans son berceau.

First, the machine described in patent FR 2,150,503, on which the preambles of claims 1 and 15 are based, mainly comprises:

• a cylindrical mandrel holder associated with a toothed wheel carrying two horizontal shafts equidistant from the axis of said mandrel holder, each of these shafts carrying a roller and resting in cradles integral with the frame,
• a chain / sprocket system actuated by jacks, arranged to cooperate with the toothed wheel so as to rotate the mandrel carrier around the axis of one or the other of the shafts housed in its cradle.

Such a machine that effectively allows to bend tubes in both directions, however, several disadvantages. Indeed, and in the first place, the speed of rotation of the chuck is not linear as a function of the cylinder deployment positions. From this fact, the accuracy of bends is impaired and hardly manageable. In addition, such a machine does not allow not to carry out bending operations, i.e. operations where the tubes are clamped and then wound between the rollers, but simply folding operations. Finally, the folding assembly (mandrel holder ...) is kept cantilevered and pressed against the frame by the chain / sprocket system associated with the cylinders. Thereby, any failure in the supply circuit of these cylinders leading to a drop in supply pressure of these last, can lead to a separation of the folding assembly, and therefore at risk of damage of the latter and especially at risk of injury to the user personnel.

• un disque rotatif autour de son axe de révolution, doté d'une rainure de guidage axiale,
• un coulisseau apte à se déplacer en translation dans la rainure,
• deux galets à entr'axe fixe disposés symétriquement de part et d'autre de l'axe de rotation du disque, entre le coulisseau et une partie de bâti,
• et un double moyen d'indexage apte à solidariser alternatiment un des galets au coulisseau et l'autre galet à la partie fixe du bâti.

The machine described in patent EP 561025 mainly comprises:

• a rotary disc around its axis of revolution, provided with an axial guide groove,
• a slide capable of moving in translation in the groove,
• two rollers with a fixed center distance arranged symmetrically on either side of the axis of rotation of the disc, between the slide and a frame part,
• and a double indexing means capable of alternately securing one of the rollers to the slide and the other roller to the fixed part of the frame.

According to this patent, during the rotation of the disc, the slide is driven to move in the groove of said disc, causing the pivoting of the roller secured to this slide around the fixed roller.

Such a machine also allows bend tubes in both directions, but present also several disadvantages. Indeed, and first place, its bending head is relatively bulky (minimum footprint equal to four times the diameter of pebbles), which leads to a limitation of the complexity shapes that can be made. In addition, the center distance of rollers must be fixed, such a machine does not allows to realize that folding operations and not bending operations. Finally, mechanically, such machine is prone to slip and bend problems of the slide inside the groove, which lead to the need to exert significant efforts, and which may result in rapid deterioration of the parts mechanical.

The present invention aims to overcome all of the aforementioned drawbacks of bend or arch current and has as main objective to provide a machine of very simple design allowing to perform bending with a very high rate both ways authorizing the production of parts complex geometry.

Another object of the invention is to provide a bending or arching machine with a bending has a small footprint and constitutes a interchangeable head leading to a significant reduction in setting time.

To this end, the invention relates to a machine for bend or arch as defined in claim 1.

The bending or arching machine according to the invention therefore makes it very easy to bend in both directions one profile, the only operation to be carried out view of changing the direction of bending consisting of controlling the movement of the indexing means. Such a machine therefore allows very high bending rates, and because of its very simple design leading to obtaining a compact folding head allows you to produce parts with complex shapes including 180 ° S-shaped bends.

In addition, it should be noted that in the event that the folding assembly equips a machine allowing classic to rotate this set around the profile in order to realize multidirectional bends, this profile remains fixed in rotation and the risk of "blow whip "are therefore limited.

• le bloc-support est percé de deux alésages traversants coaxiaux avec les axes des galets de cintrage,
• le chariot porte-outils est porté par un arbre de rotation s'étendant dans un des alésages du bloc-support, et doté, vers son extrémité opposée audit chariot porte-outils, d'un pignon d'entraínement en rotation,
• le bloc-support est relié au bâti par l'intermédiaire d'un arbre s'étendant dans le deuxième alésage dudit bloc-support et monté dans des paliers solidaires dudit bâti, ledit arbre étant doté d'un pignon d'entraínement en rotation,
  • les moyens d'entraínement en rotation respectifs de l'ensemble chariot porte-outils/bloc-support et du chariot porte-outils sont adaptés pour entraíner en rotation les pignons des arbres précités.

According to a preferred characteristic of the invention:

• the support block is pierced with two through bores coaxial with the axes of the bending rollers,
• the tool carriage is carried by a rotation shaft extending in one of the bores of the support block, and provided, towards its end opposite to said tool carriage, with a pinion for driving in rotation,
• the support block is connected to the frame by means of a shaft extending in the second bore of said support block and mounted in bearings integral with said frame, said shaft being provided with a pinion for driving in rotation,
  • the respective drive means in rotation of the tool holder carriage / support block assembly and the tool holder carriage are adapted to cause the pinions of the aforementioned shafts to rotate.

In addition, the pinions of the rotating shafts are preferably arranged so as to form a gear, and the rotary drive means include a gear wheel arranged to mesh with the pinion of the rotation shaft of the support block. Thus, the bending machine has a motorization unique arrangement to allow folding in both directions.

According to another preferred characteristic of the invention, the indexing means comprise a finger housed in a bore made in the support block, and means for moving said finger capable of engaging it, either with the tool carriage or with a part integral with the frame.

In addition, the bending machine includes preferably two strips arranged upstream of the clamping rollers with bearing surfaces between which pass the profile to be bent, said strips being associated with longitudinal displacement means and adapted to alternately fulfill a function wrinkle remover or a slider function, depending on the direction of bending.

For bending on small spokes and / or with thin-walled profiles, the sliders can also advantageously be adapted to ensure a tightening of the profiles. In this case, in addition, the means for longitudinal displacement of these strips are suitable for printing an effort of thrust capable of ensuring the compression of the profile during the translation of the latter resulting from the pivoting of the bending rollers. This provision has effect for maintaining the maximum of the thread of the compression profile and thus avoid deformation of the last.

According to another preferred characteristic of the invention the bending machine comprises means for transverse movement of the strips capable of moving them transversely relative to the longitudinal axis of the profiled between a close position where said strips perform their wrinkle eraser or strip function and a spread position where said strips are spaced from a distance suitable for remaining in support of the profile, or for allow the passage of the profile displacement means.

This provision ensures a constant support of the profile directly upstream of the rollers bending.

In addition, when the means of movement longitudinal profile typically include a clamp able to enclose the rear end of said profile, the bending machine advantageously comprises, in view to provide support and guidance for this profile, two profile guiding and holding members, arranged on either side of the axis of movement of said profile, in upstream of the bending rollers, said guide members and holding being associated with elastic means capable of allow their transverse retraction in contact with the pliers.

In addition, each strip is preferably with a post housed in a clevis the interior of which are arranged elastic means arranged to urge said post so as to allow deflections of said strip on either side of a plane passing through the axis of longitudinal displacement of the streamlined.

This arrangement leads, in fact, to obtain self-centering of the strips relative to the profile, and without requiring precise adjustment, which is always difficult to obtaining the position of said strips.

• les galets de cintrage comportent au moins deux gorges superposées, chacune adaptée pour déformer des profilés de sections différentes et/ou de sections non circulaires, éventuellement sur des rayons différents,
• des moyens de déplacement dits verticaux du bloc-support sont adaptés, pour positionner ce dernier de façon que l'une ou l'autre des gorges des galets de cintrage soit disposée dans un plan coplanaire avec l'axe de déplacement des profilés.

According to another preferred characteristic of the invention:

• the bending rollers comprise at least two superimposed grooves, each adapted to deform profiles of different sections and / or non-circular sections, possibly on different radii,
• so-called vertical displacement means of the support block are suitable for positioning the latter so that one or the other of the grooves of the bending rollers is disposed in a coplanar plane with the axis of displacement of the profiles.

This provision allows, without requiring any adjustment, to bend a profile having two different and / or non-circular sections, or successively two profiles of different sections and / or not circular.

In addition, the vertical means of movement of the support block are preferably adapted to position the latter in a position so-called retracted, where the bending rollers are arranged to allow rotation of said bending rollers relative to the profile.

Being able to arrange the support block in this low retracted position allows you to do swivel the latter or the tool carriage, once bending performed, while simultaneously moving the profiled longitudinally, and therefore leads to a gain of significant time.

According to another preferred characteristic of the invention the support block is pivotally mounted relative to on the wings of a piece in the form of a yoke forming with said support block a bending head, the frame of said bending machine with fixing means removable from said bending head.

This removable character of the head of bending made possible thanks to the small footprint of the latter allows bending on the same machine profiles of various sections without having to carry out the delicate tool adjustments required to perform the current bending machines. In addition, the removable fixing means of the bending head preferably comprise two crank pins associated with longitudinal displacement means said crankpins relative to the frame of said machine, adapted to press the soul of the yoke of said head bending against said frame, and rapid means of fluid and electrical connections. In addition, the yoke of the bending head advantageously has a core of thickness which is a function of the distance between the pinions of the rotation shafts, suitable for that the pinion of the rotation shaft of the support block meshes with the toothed wheel secured to the frame. The invention extends to a bending head adapted to be removably mounted on a frame of bending machine as defined in claim 15.

• la figure 1 est une vue en perspective partielle d'une machine à cintrer conforme à l'invention,
• la figure 2 est une vue latérale de cette machine à cintrer,
• la figure 3 est une coupe transversale par un plan vertical A de la tête de cintrage de cette machine à cintrer,
• la figure 4 est une coupe transversale partielle par un plan vertical B, représentant une réglette de cette machine à cintrer,
• la figure 5 est une vue latérale schématique de la machine à cintrer conforme à l'invention dans sa position escamotée,
• les figures 6, 7 et 8 illustrent schématiquement les phases successives de cintrage à gauche d'un profilé au moyen d'une machine à cintrer conforme a l'invention, représentées respectivement :
  • en vue de dessus selon la vue C pour les figures 6a, 6b, 6c,
  • en coupe verticale par un plan D pour les figures 7a, 7b, 7c,
  • en coupe horizontale par un plan E pour les figures 8a, 8b, 8c,
• et les figures 9a, 9b, 9c, 10a, 10b, 10c et 11a, 11b, 11c sont des schémas correspondant aux précédents lors du cintrage à droite d'un profilé.

Other characteristics, objects and advantages of the invention will emerge from the detailed description which follows, with reference to the appended drawings which show, by way of example, a preferred embodiment. On these drawings which form an integral part of this description:

• FIG. 1 is a partial perspective view of a bending machine according to the invention,
• FIG. 2 is a side view of this bending machine,
• FIG. 3 is a cross section through a vertical plane A of the bending head of this bending machine,
• FIG. 4 is a partial cross-section through a vertical plane B, representing a strip of this bending machine,
• FIG. 5 is a schematic side view of the bending machine according to the invention in its retracted position,
• FIGS. 6, 7 and 8 schematically illustrate the successive phases of bending to the left of a profile by means of a bending machine according to the invention, shown respectively:
  • in top view according to view C for FIGS. 6a, 6b, 6c,
  • in vertical section through a plane D for FIGS. 7a, 7b, 7c,
  • in horizontal section through a plane E for FIGS. 8a, 8b, 8c,
• and FIGS. 9a, 9b, 9c, 10a, 10b, 10c and 11a, 11b, 11c are diagrams corresponding to the previous ones when bending a profile to the right.

The bending machine shown example in Figures 1 to 4 is adapted to ensure the tube bending 1. Conventionally, it comprises a frame 2 on which are mounted bending means described below, and a clamp 3 capable of clamping the rear end of the tube, said clamp being housed at inside a cylindrical duct 4 and associated with drive means (not shown) capable of moving it longitudinally relative to the frame 2.

Furthermore, and in a traditional way, this bending machine can be provided with either means rotational drive of the clamp 3 about its axis longitudinal, or means for rotating the frame 2 around the clamp 3, and this in order to achieve multidirectional folds.

First, this bending machine has the particularity of having a bending head 5 adapted to be removably attached to the frame 2. This bending head 5 comprises, first of all, two bending rollers 6,7 of conventional shape provided each of two superimposed grooves 8.9 allowing deform tubes 1 of different diameters, such as by example a tube of given diameter, and the same tube 1 covered with a sheath 1a.

These bending rollers 6,7 are carried by a tool carriage 10 consisting of a plate 11, and two jaws 12, 13 on each of which is secures one of said bending rollers, each associated to a jack such as 14, able to allow them to be moved transversely relative to the axis of movement of the tube 1.

The tool carriage 10 is itself carried by a support block 15 relative to which it is rotatably mounted about an axis coaxial with the axis of one bending rollers 6.

To this end, the plate 11 of this carriage tool holder 10 is secured to a rotation shaft 16 extending into a through bore formed in the support block 15, inside which are arranged bearings such as 17. In addition, this rotation shaft 16 has a pinion 18 to the right of its end lower.

The support block 15 is mounted on the interior of a piece 19 in the form of a yoke with respect to which it is arranged to be able to rotate about an axis coaxial with the axis of the second roller bending 7.

For this purpose, this support block 15 is provided a second through bore inside which are arranged bearings such as 20, housing a shaft of rotation 21 rotatably mounted in bearings 22, 23 integral with the wings 19a, 19b of the piece in the form of a yoke 19. In addition, this rotation shaft 21 is provided, at the right of its lower end, a pinion 24 arranged to mesh with the pinion 18 of the rotation shaft 16 of the tool trolley 10.

This bending head 5 comprises, in in addition, indexing means capable of joining together, namely the tool cart 10 with support block 15, either support block 15 with part 19.

As shown in Figure 3, these indexing means comprise a finger 25 housed in a third bore in the support block 15, actuated hydraulically so as to be housed, either in a orifice 26 formed in the plate 11 of the tool carriage 10, or in an orifice 27 formed in the wing lower 19a of room 19.

As shown in Figure 1, the removable fixing means of this bending head 5 on frame 2 includes two hydraulic cylinders such as 28 each carrying a crank pin 29 arranged to come and stay in a notch 30 formed in the core of the part 19, and thus ensuring the blocking of the bending head 5 against the frame 2. In addition, quick connection devices fluid and electrical (not shown) are provided to allow the change of bending head 5.

The pivoting of the rollers 6, 7 of this head bending are obtained by means of a wheel toothed 31 mounted under the frame and operated by means of a motor 32 and a chain transmission 33, said wheel toothed being arranged to mesh with the pinion 24 of the rotation shaft 21 to the support block 15.

It should be noted, for this purpose, that the center distance sprockets 18, 24, and therefore the diameter of these sprockets may be different from a bending head 5 with respect to to another, the thickness of the core of the piece 19 of each bending head is adapted so that the pinion 24 of the rotation shaft 21 of the support block 15 meshes with the gear 31.

The bending machine further comprises two strips 34, 35 suitable for alternately ensuring either a slider function, that is to say of guiding the tube 1 with recovery of effort, that is to say a fold-erase function.

As shown in Figure 4, each of these strips 34, 35 has two superimposed grooves 36, 37 combined with those of the bending rollers 6, 7.

These strips 34, 35 are further mounted inside a yoke 38 and has for this purpose a tenon 39 coming to be housed in this clevis 38, to which it is connected by means of a pin 40 authorizing deflections said strips on either side of a plane passing through the axis of the tube 1.

In addition, springs such as 41, 42 are interposed between the pin 39 and each of the wings of the yoke 38, so as to stabilize the strips 34, 35.

Each of these strips 34, 35 is, in besides, conventionally, mounted on a longitudinal rail 43 associated with a jack 44 making it possible to move longitudinally said strips.

In addition, this rail is itself mounted on a carriage 45 provided with a slide 46 for guiding said rail, each of said carriages 45 being associated with a jack (not shown) suitable for moving it transversely relative to the axis of movement of the tube 1.

The bending machine according to the invention also includes members for guiding and holding the tube 1 arranged on either side of the axis of movement of the latter, upstream of the bending rollers 6,7.

These guiding and holding members include, as shown in Figure 1, two casters 47, 48 each carried by an arm such as 49, extending through a lumen in the conduit 4 for guiding the clamp 3, said arms being mounted swivel, each on a leg such as 50 integral a flange 51 mounted on the pipe 4.

In addition, spiral springs (not seen in Figure 1) arranged around the axis of rotation of arms 49 and integral with legs 50 and said arms are adapted to maintain these, in the absence of solicitation, in a position where they are substantially tilted backwards with respect to the direction of travel of tube 1.

Thus, the rollers 47, 48 provide the holding and guiding the tube 1 during movement longitudinal of the latter, but retract transversely under the effect of the pressure of the clamp 3 when the latter comes into contact with said casters.

• soit de façon à amener l'une ou l'autre des gorges 8, 9 des galets de cintrage 6, 7 dans un même plan que l'axe de déplacement longitudinal du tube 1,
• soit dans une position escamotée, représentée à la figure 5, où la tête de cintrage 5, se trouve dans une position escamotée par rapport au tube 1, dans laquelle les galets de cintrage 6, 7 se trouvent en dessous dudit tube, permettant ainsi simultanément de faire pivoter ladite tête de cintrage tout en déplaçant longitudinalement le tube 1.

Finally, the bending head 5, the hydraulic cylinders 28, and the carriages 45 slide carrier 34, 35, are mounted on a structure of the frame 2 capable of being able to move vertically, with reference to FIGS. 1 and 2, and supported by a jack 53 adapted to allow said elements to be moved:

• either so as to bring one or the other of the grooves 8, 9 of the bending rollers 6, 7 in the same plane as the axis of longitudinal displacement of the tube 1,
• either in a retracted position, shown in Figure 5, where the bending head 5, is in a retracted position relative to the tube 1, in which the bending rollers 6, 7 are located below said tube, thus allowing simultaneously to rotate said bending head while longitudinally moving the tube 1.

It should be noted that in order to authorize vertical displacements, the pinions 18, 24 of the shafts rotation 16, 21 of the bending head 5 have a height greater than that of toothed wheel 31, adapted to keep the pinion 24 meshed with said wheel toothed, whatever the vertical position of said bending head.

The operation of the bending machine according to the invention is explained below in reference to Figures 6 to 11.

Firstly, with a view to bending towards the left of the tube 1, the indexing finger 25 is disposed, as shown in Figure 6b, so as to secure in rotation the tool carriage 10 and the support block 15.

In addition, as shown in FIG. 6a, the bending rollers 6, 7 and the strips 34, 35 are brought into their close position where they enclose the tube 1.

Bending is carried out by bringing the wheel tooth 31 to turn clockwise watch. During this rotation, this toothed wheel 31 causes the rotation of the pinion 24 in the opposite direction clockwise. In addition, the support block 15 being secured in rotation to the tool carriage 10, the rotation shaft 21 is therefore also blocked in rotation relative to said support block, and rotation of the pinion 24 causes the pivoting of the carriage assembly tool holder 10 / support block 15 around a coaxial axis with the axis of the bending roller 7 (Figure 7c).

During this bending, moreover, the strip 34 is moved longitudinally while the strip 35 serves as a fold eraser. Finally as shown in Figures 8a and 8b, once the bending has been completed, the rollers bending 6, 7 and the strip 34 are separated so as to release the tube 1, and the bending head 5 is possibly retracted before being caused to pivot in reverse, to allow moving longitudinally the tube 1 before the next bending of this latest.

During this reverse pivot represented in FIGS. 9a to 9c, obtained by bringing the toothed wheel to turn counterclockwise, the strip 34 is conventionally brought back. Finally, once the pivoting has been completed and the bending head 5 returned to its initial position, the strip 35 is transversely spaced from the tube 1.

Second, for bending at right of the tube 1, the indexing finger 25 is arranged, as as shown in Figure 10b, so as to secure in support block 15 and part 19.

Therefore, the rotation of the toothed wheel 31 leads to the pivoting of the only tool carriage 10, the support block 15 and therefore its rotation shaft 21 being secured in rotation to the part 19 (Figures 11b and 11c).

In this case, moreover, the strip 35 is moved longitudinally, while the strip 34 is fold eraser.

Due to the simplicity of the movements of pivoting of the bending head 5, explained above, the bending cycle times obtained with the bend according to the invention are very short, leading has a high production rate. In addition, the low size of this bending head allows for pieces of complex geometry.

Claims (15)

1. Machine for bending or cambering a profile (1) such as a rod, tube, wire or the like, comprising a frame (2) on which are mounted bending means, and means (3) for moving the profile (1) longitudinally relative to the said frame, the bending means comprising :

   two bending rollers (6, 7) mounted on a tool holder carriage (10) and provided with supporting surfaces (8, 9) between which the profile (1) to be bent is passed and then rolled, and

   a supporting block (15) for the tool holder carriage (10) in relation to which the latter is pivotably mounted about an axis of rotation coaxial with the axis of one of the bending rollers (6), the said bending machine being characterized in that the said supporting block (15) is pivotably mounted with respect to the frame (2) of the machine about an axis of rotation coaxial with the axis of the other bending roller (7), and in that the bending means comprise:

   indexing means (25) able to interlock in rotation, either the tool holder carriage (10) and the supporting block (15), in a so-called left hand bending state, or the supporting block (15) and the frame (2), in a so-called right hand bending state, and

   rotational drive means (31-33) able to pivot the tool holder carriage (10)/supporting block (15) assembly in a first direction of rotation in the left hand bending state of the indexing means (25) and to pivot the tool holder carriage (10) in a direction of rotation opposite to the first direction of rotation in the right hand bending state of the indexing means (25).
2. Bending machine according to claim 1, characterized in that:

   the supporting block (15) is pierced with two bores passing through it, coaxial to the axes of the bending rollers (6, 7),

   the tool holder carriage (10) is carried by a rotating shaft (16) extending into one of the bores of the supporting block (15) and is provided, at its end opposite the said tool holder carriage, with a rotational drive pinion (18),

   the supporting block (15) is attached to the frame (2) via a shaft (21) extending into the second bore of the said supporting block and mounted in bearings (22, 23) secured to the said frame, the said shaft being provided with a rotational drive pinion (24),

   the means (31-33) for driving in rotation the tool holder carriage (10)/supporting block (15) assembly and the tool holder carriage (10) respectively are adapted so as to drive the pinions (18, 24) of the previously mentioned shafts (16, 21) in rotation.
3. Bending machine according to claim 2, characterized in that:

   the pinions (18, 24) of the rotating shafts (16, 21) are arranged so as to intermesh,

   the rotational drive means (31-33) include a toothed wheel (31) arranged so as to mesh with the pinion (24) of the shaft (21) for rotating the supporting block (15).
4. Bending machine according to one of the preceding claims, characterized in that the indexing means comprise a finger (25) housed in a bore provided in the supporting block (15), and means for moving the said finger able to engage it either with the tool holder carriage (10) or with a part (19) secured to the frame (2).
5. Bending machine according to one of the preceding claims, characterized in that it includes two guide strips (34, 35) positioned upstream from the bending rollers (6, 7) and provided with supporting surfaces (36, 37) between which the profile (1) to be bent passes, the said guide strips being associated with means (43, 44) for longitudinal movement and adapted to fulfil alternately a straightening function or a guiding function, according to the bending direction.
6. Bending machine according to claim 5, characterized in that the guide strips (34, 35) are adapted so as to ensure gripping of the profile (1), the means (43, 44) for moving the said guide strips longitudinally being adapted to exert a thrusting force capable of compressing the profile (1) as the latter is moved in translation as a result of the pivoting of the bending rollers (6, 7).
7. Bending machine according to either of claims 5 or 6, characterized in that it includes means (45) for moving the guide strips (34, 35) transversely, capable of moving them transversely relative to the longitudinal axis of the profile (1) between a closed position where the said guide strips fulfil their straightening function or guiding function, and a separated position where the said guide strips are separated by a distance adapted so as to remain supporting the profile (1), or to permit the passage of the means (3) for moving the profile (1).
8. Bending machine according to one of claims 5 to 7, characterized in that each guide strip (34, 35) is provided with a peg (39) housed in a clevis (38) inside which are disposed elastic means (41, 42) arranged so as to tension the said peg in such a way as to permit retractions of the said guide strip either side of a plane passing through the axis of longitudinal movement of the profile (1).
9. Bending machine according to one of the preceding claims, characterized in that:

   the bending rollers (6, 7) have at least two superimposed grooves (8, 9), each one adapted to deform profiles (1) with different cross sections and/or non-circular cross sections, possibly through different radii,

   means (53) for moving the said verticals of the supporting block (15) are adapted so as to position the latter in such a way that one or other of the grooves (8, 9) of the bending rollers (6, 7) is disposed in a plane coplanar with the axis of movement of the profiles (1).
10. Bending machine according to claim 9, characterized in that the vertical means (53) for moving the supporting block (15) are adapted so as to position the latter in a supplementary so-called retracted position, where the bending rollers (6, 7) are disposed in such a way as to permit the rotation of the said bending rollers relative to the profile (1).
11. Bending machine according to one of the preceding claims of which the means for moving the profile (1) longitudinally include a clamp (3) capable of gripping the rear end of the said profile, characterized in that it includes two devices (47, 48) for guiding and holding the profile (1), disposed either side of the axis of movement of the said profile, upstream from the bending rollers (6, 7), the said guiding and holding devices being associated with elastic means (52) which are able to allow them to retract transversely in contact with the clamp (3).
12. Bending machine according to one of the preceding claims, characterized in that the supporting block (15) is pivotably mounted with respect to the wings (19a, 19b) of a clevis-shaped part (19) forming a bending head (5) with the said supporting block, the frame (2) of the said bending machine including detachable means (28, 29) for securing the said bending head.
13. Bending machine according to claim 12, characterized in that the detachable means for securing the bending head (5) include two crank pins (29) associated with means (28) for moving the said crank pins longitudinally, relative to the frame (2) of the said machine, adapted so as to cause the core of the clevis of the said bending head to be pressed against the said frame, and means for rapidly connecting fluids and electricity.
14. Bending machine according to claims 3 and 13 taken together, characterized in that the clevis (19) of the bending head (5) has a core with a thickness which is a function of the distance between the axes of the pinions (18, 24) of the rotating shafts (16, 21), adapted so that the pinion (24) of the rotating shaft (21) of the supporting block (15) meshes with the toothed wheel (31) secured to the frame (2).
15. Bending head adapted so that it can be mounted in a detachable manner on a frame (2) of the bending machine, comprising:

    two bending rollers (6, 7) mounted on a tool holder carriage (10) and provided with supporting surfaces (8, 9) between which the profile (1) to be bent is passed and then rolled, and

    a supporting block (15) for the tool holder carriage (10) in relation to which the latter is pivotably mounted about an axis of rotation coaxial with the axis of one of the bending rollers (6), characterized in that the said supporting block is pivotably mounted about an axis of rotation coaxial with the axis of the other bending roller (7), inside a clevis-shaped part (19) which can be secured in a detachable manner to the frame (2) of the machine, and in that the bending head comprises

    indexing means (25) able to interlock in rotation, either the tool holder carriage (10) and the supporting block (15), in a so-called left hand bending state, or the supporting block (15) and the clevis-shaped part (19), in a so-called right hand bending state, and

    rotational drive means (16, 18, 21, 24) able to pivot the tool holder carriage (10)/supporting block (15) assembly in a first direction of rotation in the left hand bending state of the indexing means (25) and to pivot the tool holder carriage (10) in a direction of rotation opposite to the first direction of rotation in the right hand bending state of the indexing means (25).

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