EP3009207A1 - Counterform for crossbow-type tube bender - Google Patents

Abstract

The present invention relates to a counter-form (1) for a crossbow (2) for bending a tube (3), substantially in the form of a block (4) of which a first and a second face (12, 13) opposed are intended to be placed either one in contact with said tube (3), said first face (12) having a first transverse groove (14) of substantially semi-cylindrical shape adapted to fit a portion of said tube (3). ), characterized in that said second face (13) comprises a second transverse groove (15) having a projecting region adapted to provide a contact at least three points with a curved portion (31) of concave shape of said tube (3) .

Description

The present invention relates to a cross-form for a bending crossbow of a tube, substantially in the form of a block of which first and second opposite faces are intended to be placed either one or the other. contact of said tube, said first face having a first transverse groove of substantially semi-cylindrical shape adapted to fit a portion of said tube.

Crossbows for bending a tube are conventionally composed of a half-moon bending form, and a transverse bar supporting a pair of generally identical counter-forms called to cooperate with the half-moon bending form.

Usually, the pair of counter bending forms is pivotally mounted on the crossbar, so as to gradually follow the movement of each of the linear parts of the tube located on either side of the zone being bent. There are currently on the market various models of counterforms for crossbow bending, suitable for different applications and configurations.

We know in particular of the document FR 2 626 505 an apparatus for bending a crossbow type tube comprising two pairs of against forms respectively implemented according to the desired bending radius of the tube. These counter forms have a pavé shape of which two opposite faces each comprise a semicircular groove for accommodating a portion of the tube.

The document WO 2012/129345 also discloses an apparatus for bending a crossbow type tube having two counter-shaped blocks and having two opposite faces equipped with grooves whose profile is adapted to accommodate respectively two different diameters of tube.

Because of their structure, against forms of this type have sharp outer edges that can sometimes be the source of weakening zones or inadvertent deterioration of the tube.

Indeed, in the field, the user of a bending crossbow can be made to perform two successive bends, in the opposite direction, on the same tube, especially when this tube must span one or more pipes arranged horizontally, it is that is to say to achieve a configuration commonly referred to as "cocked hat" or "bayonet".

During such an operation, to perform the second bending of the tube, one of the two bending forms against is placed in contact with the curved portion of the tube from the first bending. It has been observed that the sharp edges of the counter form, on which the tube is supported, generate two slight recesses on the surface of the latter. These recesses are not only unsightly, but can eventually cause significant damage to the tube.

The present invention aims to overcome this drawback by proposing a bending form against providing a better contact surface with an already curved portion of a tube, said counter bending form having at least one face devoid of sharp edges, so as to avoiding the formation of weakening zones at the tube, such counter form being further designed in such a way as to allow the bending of tubes of different diameters.

For this purpose, it relates to a counter shape of the kind indicated in the preamble, characterized in that said second face comprises a second transverse groove having a projecting region adapted to provide a contact in at least three points with a curved portion of concave appearance said tube.

According to an alternative embodiment, said second groove has a first and a second portion, of substantially semi-frustoconical shape, joined to each other by their smallest respective side at a junction zone and located relative to one another. other such that two lines passing respectively through the junction zone and the long side of each of the first and second portions form between them an angle, said long sides extending respectively along two opposite edges of said second face.

Preferably, said angle is between 5 ° and 50 °.

According to a feature of the invention, said first and second portions are symmetrical with respect to a plane perpendicular to said second face.

The invention also provides that the edges formed between the lateral edges of said first and second portions and the second face of the counter form are rounded.

Likewise, each of the ridges formed at the long side of the first and second portions is rounded.

According to another embodiment of the invention, the groove has a semi-cylindrical bottom and a convex upper face.

In this case, said upper face may be curved in an arc of a radius of between 25mm and 55mm.

Furthermore, an additional feature of the counter form according to the invention is further defined by the fact that the first groove is arranged to match different diameters of tubes.

The present application also aims to protect a bending crossbow of a tube, characterized in that it comprises at least one against form as previously described.

• La figure 1 illustre une vue en perspective d'une variante de réalisation d'une contre forme pour arbalète de cintrage d'un tube selon l'invention,
• La figure 2 représente une vue de profil de la contre forme de la figure 1,
• La figure 3 illustre une vue en perspective d'une autre variante de réalisation d'une contre forme pour arbalète de cintrage d'un tube selon l'invention,
• La figure 4 représente une vue de profil de la contre forme de la figure 3, et
• La figure 5 illustre une vue d'une arbalète de cintrage d'un tube équipée d'une paire de contre formes de la figure 1.

The present invention will be better understood on reading the description of exemplary embodiments made with reference to the appended figures, provided as non-limiting examples, and in which:

• The figure 1 illustrates a perspective view of an alternative embodiment of a crossbow shape for bending crossbow of a tube according to the invention,
• The figure 2 represents a profile view of the counter shape of the figure 1 ,
• The figure 3 illustrates a perspective view of another alternative embodiment of a counter-shape for crossbow bending a tube according to the invention,
• The figure 4 represents a profile view of the counter shape of the figure 3 , and
• The figure 5 illustrates a view of a bending crossbow of a tube equipped with a pair of counter forms of the figure 1 .

With reference to the figures, counterforms 1, 10 for crossbow 2 for bending a tube 3, are each substantially in the form of a block 4, 40 comprising an upper face 5, 50 and a lower face 6, 60 interconnected by a through hole 7, 70. It is intended for the passage of an axis of rotation 8 by means of which a counter-form 1, 10 is capable of being pivotally mounted on a crossbar 9 of the crossbow 2 of bending to cooperate with the form of bending 11 in half-moon of the latter (cf. Fig. 5 ).

Each of the counterforms 1, 10 also comprises a first and a second opposite face 12, 13, 120, 130 intended to be placed either one in contact with a portion of the tube 3.

In a conventional manner, the first face 12, 120 of the counterforms 1, 10 comprises a first transverse groove 14, 140 of substantially semi-cylindrical shape adapted to fit a portion, for example a linear portion, of the tube 3. Preferably, the first transverse groove 14, 140 of the first face 12, 120 respective against forms 1, 10 is profiled such that it can suitably accommodate different diameters of tubes 3, for example 10 to 22 mm.

Thus, to bend, one after the other, tubes 3 of different diameters, it is not systematically necessary to proceed to replace a counter form 1, 10 by another against form 1, 10 being different from the previous by its radius of curvature.

The second face 13, 130 comprises a second transverse groove 15, 150 having a projecting region specifically adapted to provide contact at at least three points, or even continuous contact, with a portion 31 already curved, of concave shape, of a tube 3.

More particularly, in the embodiment variant illustrated in FIGS. Figures 1 and 2 , the second groove 15 of the counter form 1 has a first and a second portion 16, 17, of substantially semi-frustoconical shape, joined together at their respective smaller sides, so as to form a junction zone 18. two portions thus together have an hourglass shape.

In the variant embodiment illustrated, the first and second portions 16, 17 are furthermore symmetrical with respect to a plane perpendicular to the second face 13 and are located relative to each other in such a way that two straight lines D1, D2 passing respectively through the junction zone 18 and the long side 19, 20 of each of the first and second portions 16, 17 form between them an angle α, preferably between 5 ° and 50 °.

Moreover, the long sides 19, 20 of each of the first and second portions 16, 17 extend respectively along each of the lateral edges 21, 22 of the second face 13.

In addition, the edges 23, 24, 25, 26 formed between the lateral edges of said first and second portions 16, 17 and the second face 13 of the counter form 1 are advantageously rounded.

Likewise, each of the ridges 27, 28 formed at the long side 19, 20 of the first and second portions 16, 17 is rounded.

Such a configuration is advantageous because the hourglass shape of the transverse groove 15 of the second face 13 of the counter form 1 not only allows to accept tubes of different diameters, for example from 10 to 22 mm, like the first groove 14 of the first face 12, but also to avoid the marking of the tube 3, given the total absence of sharp edges in contact with the bent portion considered the tube 3. In addition, because the contact between the groove 15 and the bent portion of the tube 3 is increased from two to at least three contacts, the contact force is lowered, with consequent limited marking, or even the absence of marking of the tube 3.

The embodiment variant illustrated in Figures 3 and 4 has the same advantages. Indeed, against form 10 for crossbow 2 bending comprises on its second face 130 intended to come into contact with an already curved portion of a tube 3, a groove 150 which has a bottom 29 of semi-cylindrical shape and a upper face 30 of convex shape, preferably curved in an arc of a circle between 25mm and 55mm, which eliminates any protruding angle on the second face 130. Nevertheless, this configuration does not have the same character adaptability than that of the variant of the Figures 1 and 2 and requires, for each diameter of the tube to be worked, a counter form 10 whose groove 150 is specifically adapted.

Of course, many modifications can be made to the examples described above without departing from the scope of the present invention.

Claims (10)

Counter-shaped (1, 10) for crossbow (2) for bending a tube (3), substantially in the form of a block (4, 40) having a first and a second face (12, 120, 13) , 130) are intended to be placed either one in contact with said tube (3), said first face (12, 120) having a first transverse groove (14, 140) of substantially semi-cylindrical shape adapted to espousing a portion of said tube (3), characterized in that said second face (13, 130) comprises a second transverse groove (15, 150) having a projecting region adapted to provide contact at at least three points with a curved portion ( 31) of concave shape of said tube (3). Against the form (1) for crossbow (2) bending according to claim 1, characterized in that said second groove (15) has a first and a second portions (16, 17) of substantially semi-frustoconical shape, joined together by their smallest respective side at a junction zone (18) and situated relative to one another in such a way that two straight lines (D1, D2) passing respectively through the junction zone (18) and the long side (19, 20) of each of the first and second portions (16, 17) form an angle α between them, said long sides (19, 20) extending respectively along each of the lateral edges of said second face ( 13). Against form (1) for crossbow (2) bending according to claim 2, characterized in that said angle α is between 5 ° and 50 °. Counterform (1) for a crossbow (2) for bending according to any one of claims 2 or 3, characterized in that said first and second portions (16, 17) are symmetrical with respect to a plane perpendicular to said second face ( 13). Counterweight (1) for crossbow (2) bending according to any one of claims 2 to 4, characterized in that the edges formed between the side edges (23, 24, 25, 26) said first and second portions (16, 17) and the second face (13) of the counter form (1) are rounded. Counterweight (1) for a crossbow according to one of Claims 2 to 5, characterized in that each of the ridges formed at the long side (19, 20) of the first and second portions (16, 17) is rounded . Against form (10) for crossbow (2) bending according to claim 1, characterized in that said groove (150) has a bottom (29) of semi-cylindrical shape and an upper face (30) of convex shape. Against form (10) for crossbow (2) bending according to claim 7, characterized in that said upper face (30) is curved in an arc of a circle with a radius of between 25mm and 55mm. Counterweight (1, 10) for a crossbow according to any one of claims 1 to 8, characterized in that the first groove (14, 140) is arranged to fit different tube diameters (3). Crossbow (2) for bending a tube (3), characterized in that it comprises at least one counter-form (1, 10) according to any one of Claims 1 to 9.

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